AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 855 PM CDT MON JUL 17 2006 .DISCUSSION... INITIAL SMALL CONVECTIVE CLUSTER OVER IOWA HAS GROWN UPSCALE AND IS BEGINNING TO PROPAGATE SOUTHWESTWARD TOWARD THE BETTER INFLOW OVER NORTHERN MISSOURI. MEANWHILE...THE NORTHERN END NEAR DUBUQUE CONTINUES SEVERE WHERE THE UPPER LEVEL WESTERLY FLOW IS MORE FAVORABLE ALONG THE SYNOPTIC COLD FRONT. IN BETWEEN...CONVECTION BETWEEN BURLINGTON AND MOLINE IS DECREASING AS IT MOVES INTO AN AREA WITH MORE SUBSTANTIAL CONVECTIVE INHIBITION AS REVEALED BY THE 00Z LINCOLN AND DAVENPORT SOUNDINGS. MAIN COLD FRONT CURRENTLY EXTENDS FROM NEAR MADISON TO DES MOINES TO NORTH OF KANSAS CITY. THE NEW 00Z RUC MODEL BARELY BRINGS THIS BOUNDARY TO PEORIA BY 12Z. THIS LOOKS REASONABLE...BUT THE OUTFLOW BOUNDARY FROM THE CURRENT CONVECTION MAY MAKE IT THAT FAR A LITTLE SOONER. WILL BUMP UP POPS A LITTLE OVER THE NORTHWEST OVERNIGHT WHERE THE CONVECTION HAS THE BEST CHANCE OF SURVIVING...BUT WILL KEEP POPS IN THE CHANCE/SLIGHT CHANCE RANGE OVER THE CENTRAL AND NORTH AS BEFORE. && .PREV DISCUSSION... 232 PM CDT MON JUL 17 2006 LATEST SURFACE ANALYSIS HAD A RIDGE OF HIGH PRESSURE EXTENDING FROM THE GULF COAST INTO NEW ENGLAND. MEANWHILE...LOW PRESSURE WAS CENTERED NEAR JAMES BAY...WITH A WEAK COLD FRONT EXTENDING SOUTHWEST THROUGH THE GREAT LAKES AND INTO THE CENTRAL PLAINS. ALOFT...FLAT RIDGING WAS IN PLACE OVER THE SOUTHERN 2/3 OF THE LOWER 48 STATES...WITH INCREASINGLY AMPLIFIED UPPER FLOW ACROSS THE NORTHERN TIER OF STATES AND SOUTHERN CANADA. THE INITIAL WAVE OF INTEREST IS MOVING ACROSS ONTARIO AND THE UPPER LAKES REGION. MAIN CONCERNS OVER THE NEXT FEW DAYS REVOLVE AROUND PRECIPITATION CHANCES TONIGHT/TUESDAY AS THE UPSTREAM COLD FRONT MOVES INTO AND THROUGH REGION...AS WELL AS CONTINUED HOT/HUMID CONDITIONS. 12Z MODELS IN GOOD OVERALL AGREEMENT THE OVERALL PATTERN EXPECTED TO IMPACT THE REGION THE NEXT SEVERAL DAYS AND ARE SHOWING BETTER RUN-TO-RUN CONTINUITY OF LATE.. GUIDANCE TEMPERATURES CLOSE/REASONABLE...SO WILL NOT STRAY FAR. SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT... TONIGHT AND TUESDAY...WEAK COLD FRONT WILL MAKE SLOW PROGRESS INTO THE FORECAST AREA TONIGHT AND PASS THROUGH BY TUESDAY AFTERNOON. THE FRONT DOES NOT HAVE TOO MUCH UPPER FORCING BEHIND IT AS THE MAIN UPPER WAVE STAYS WELL TO THE NORTH AND EAST OF FORECAST AREA. LOW LEVEL MOISTURE IS POOLING ALONG THE BOUNDARY AND IS CONTRIBUTING TO EXTREME INSTABILITY IN THE VICINITY OF THE FRONT. HOWEVER...THE PRE-FRONTAL AIRMASS IS QUITE CAPPED AS EVIDENCED BY THE THE 12Z DVN/ILX SOUNDINGS. AS A RESULT...MOST OF THE CONVECTION THUS FAR HAS BEEN AFTER FROPA OCCURS AND MID LEVEL COOLING TAKES PLACE. WILL KEEP SHOWER/STORMS CHANCES IN THE FORECAST AREA THROUGH THE PERIOD...WITH THE BETTER THREAT TIME ARRIVING BEHIND THE FRONT. HOWEVER...THE THREAT WILL DECREASE WITH TIME AS THE UPPER FORCING MOVES FURTHER AWAY FROM THE REGION. TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...UPPER RIDGING RETURNS TO THE REGION TUESDAY NIGHT AND LINGERS THROUGH THE REST OF THE PERIOD. THIS WILL QUICKLY PUSH THE REMNANTS OF THE FRONT BACK NORTHWARD AND RETURNS THE HOT/HUMID CONDITIONS OF THE PAST FEW DAYS (NOT THAT THE FRONT REALLY COOLED US MUCH ANYWAY). DO NOT EXPECT A SIGNIFICANT PRECIPITATION THREAT AS THE FRONT MOVES BACK NORTH AS THE BEST FORCING/WAA WILL OCCUR OVER THE PLAINS IN ADVANCE OF THE NEXT UPPER WAVE. THIS SHOULD DEVELOP AN MCS OVER THE NORTHERN PLAINS WEDNESDAY INTO WEDNESDAY NIGHT...BUT CURRENT INDICATIONS ARE THAT THIS SYSTEM WILL STAY WELL NORTH OF THE FORECAST AREA. THURSDAY AND THURSDAY NIGHT...NEXT UPPER WAVE...MUCH LIKE THE CURRENT ONE...WILL MOVE ACROSS ONTARIO AND THE UPPER LAKES AND PUSH ANOTHER COLD FRONT INTO THE REGION. THE AIRMASS IS EXPECTED TO BE SIMILAR TO THE ONE WE HAVE TODAY...SO WE WILL LIKELY BE CAPPED AND HAVE TO WAIT UNTIL FROPA FOR PRECIPITATION CHANCES TO RETURN. LONG TERM...FRIDAY THROUGH MONDAY...MODELS/ENSEMBLES IN REASONABLE AGREEMENT THROUGH THE PERIOD. IF THINGS PAN OUT AS PROGGED...A PATTERN CHANGE IS ON THE WAY AND WE CAN EXPECT A BREAK FROM THE RECENT HEAT/HUMIDITY. THE FRONT FROM THURSDAY NIGHT SHOULD PUSH WELL SOUTH OF THE REGION ON FRIDAY...TO BE REPLACED BY HIGH PRESSURE. THIS HIGH AND A GENERAL NORTHWEST FLOW ALOFT WILL ALLOW TEMPERATURES TO RETURN TO NORMAL LEVELS FOR LATE JULY. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 04/BAK il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE INDIANAPOLIS IN 700 PM EDT MON JUL 17 2006 .AVIATION...DISCUSSION FOR THE 00Z TAFS. HI PRESS OVR THE CAROLINAS WILL CONTINUE TO DOMINATE THE WEATHER OVER CENTRAL INDIANA FOR THE NEXT 12 HRS. RUC HAS A GOOD HANDLE ON CONVETION OVER IA AT THIS TIME SO WILL USE THAT AS GUIDANCE FOR THIS TAF FORECAST. GROUND IS STARTING TO DRY OUT BUT LLVL MOISTURE IS INCREASING SLIGHTLY OUT AHEAD OF NEXT SYSTEM. A CHECK OF THE CCFP KEEPS CONVECTION OUT OF ALL TERMINAL SITES THRU 03Z AND WILL NOT MENTION IN THE TAFS BEFORE THEN. RUC HAS CDFNT GETTING NEAR LAF AROUND 12Z THEN INTO HUF AND IND FM 18-20Z. WILL GO AHEAD AND PUT A VCTS IN LAF AROUND 12Z AND HUF/IND AROUND 19Z WITH BMG FINALLY AT 20Z. WILL KEEP IT AT A VCTS MENTION FOR NOW AS THERE IS STILL CONSIDERABLE UNCERTAINTY AS FAR AS WHETHER CONVECTION WILL HOLD TOGETHER. FOG WILL AGAIN BE AN ISSUE AT HUF AND LAF AND WILL PUT IN MVFR VISBY DUE TO PERSISTENCE. && .DISCUSSION... FORECAST FOCUS IS ON CHANCES FOR STORMS TONIGHT/TUESDAY AS WELL AS TEMPS INTO THURSDAY. AT 17Z SURFACE HIGH PRESSURE WAS ACROSS WV WHILE A COLD FRONT EXTENDED FROM WI INTO IA. CU HAD FORMED ACROSS THE FORECAST AREA /FA/. MODELS ARE PRETTY SIMILAR. GFS IS A BIT STRONGER WITH SURFACE LOW BY THURSDAY...BUT THIS COULD BE DUE TO FEEDBACK ISSUES. WILL USE A BLEND FOR MOST TIMES. COLD FRONT WILL APPROACH THE NORTHERN FA AFTER MIDNIGHT TONIGHT. ALTHOUGH CONVECTION AHEAD OF FRONT WILL BE WEAKENING...FEEL THERE IS ENOUGH FORCING WITH ASSOCIATED UPPER WAVE TO KEEP SLIGHT CHANCE POPS IN THE NORTHERN FA. ELSEWHERE DRY AND MUGGY CONDITIONS WILL CONTINUE. WENT A LITTLE COOLER THAN MOS AT SOME AREAS WHERE COOLING THE PAST FEW NIGHTS HAS LED TO READINGS LOWER THAN GUIDANCE. ELSEWHERE WENT NEAR GUIDANCE AROUND 70 DEGREES. FRONT WILL WEAKEN ACROSS THE FA ON TUESDAY. UPPER SUPPORT IS NIL BY AFTERNOON. THUS FEEL THAT ONLY SLIGHT CHANCE POPS ARE IN ORDER. CONDITIONS WILL STILL BE HOT BUT CLOUDS AROUND SHOULD KEEP THEM FROM THE WARMER GUIDANCE VALUES. WENT CLOSER TO THE COOLER MET NUMBERS MOST AREAS. UPPER RIDGE BUILDS BACK INTO THE FA ON WEDNESDAY ALLOWING THE HEAT TO CONTINUE. HINTS OF AN MCS SHOW UP ACROSS NORTHERN IL BUT FEEL THAT THIS WOULD STAY OUT OF THE FA BASED ON THICKNESS PROGS. ANOTHER FRONT MOVES IN ON THURSDAY. TEMPERATURES AHEAD OF THE FRONT COULD REACH THE MID TO UPPER 90S WITH A GOOD SW FLOW. WILL CONTINUE WITH HOT FORECAST AND MENTION HIGH HEAT INDICIES IN HWO FOR NOW. WEEKEND LOOKS DRY AT THE MOMENT BUT WILL HAVE TO WATCH AS FA IS IN NORTHWEST FLOW AND TIMING OF FRONTS AND AVAILABILITY OF MOISTURE IN QUESTION. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PUBLIC...CS AVIATION...SALLY in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 152 PM CDT MON JUL 17 2006 .UPDATE... CONVECTIVE POTENTIAL CONTINUES TO EVOLVE ACROSS THE CWA. CU FIELD HAS STARTED TO DEVELOP OVER NRN/CTRL WI ASSOCIATED WITH SHORTWAVE AND AHEAD OF THE SFC COLD FRONT...WHICH AT 18Z WAS DRAPED FROM JUST NORTH OF KGRB THROUGH KLSE TO THE SW CORNER OF IA AND BACK INTO SERN NEB/CTRL KS. SECOND CU FIELD IS DEVELOPING IN NWRN IA IN AN AREA OF ENHANCED SFC CONVERGENCE. RUC ANALYSIS AND SOUNDINGS INDICATE SFC-BASED AND MIXED-LAYER CIN HAS DECREASED TO VIRTUALLY NIL IN NRN IL/SRN WI/FAR ERN IA...WITH MLCAPES UP TO 4500 J/KG AND SFC-BASED CAPES UP TO 5000 J/KG. SFC MOISTURE CONVERGENCE IS MAXIMIZED ALONG A THE COLD FRONT...WITH DEEP MOISTURE CONVERGENCE ALSO APPARENT FROM KAWK TO KMKE. SURFACE MOISTURE CONTINUES TO POOL IN THE MID-70S IN THE AREA /THOUGH 77-79 DEGREE READINGS ARE SUSPECT/ AHEAD OF THE SFC FRONT. SFC PRESSURE RISE/FALL COUPLET ACROSS MN/IA INDICATES FRONT IS STILL PUSHING ESEWD. THOUGH CU FIELDS ARE APPARENT TO THE NORTH AND WEST... LACK OF CU ACROSS THE CWA INDICATES WE ARE STILL CAPPED. AREA OF SHOWERS CONTINUES TO FESTER IN NWRN CWA BUT STILL REMAINS WEAK. WILL CONTINUE TO WATCH NRN CWA FOR CU DEVELOPMENT INDICATING CAP WEAKENING... AND ALSO WILL LOOK AT 20Z SOUNDING FOR CAP STRENGTH. STILL BELIEVE CAP WILL WEAKEN WITH PUSH OF COOLER MID-LEVEL AIR... WITH THUNDERSTORM DEVELOPMENT BUILDING SWWD OUT OF WI THROUGH THE CWA AND PUSHING EWD/SEWD AHEAD OF THE FRONT. WILL MONITOR NWRN IA FOR DEVELOPMENT AS WELL...AS STORMS THAT DEVELOP THERE WOULD HAVE THE POTENTIAL TO MOVE INTO THE CWA. BELIEVE CONVECTIVE INITIATION WILL TAKE PLACE LATER THIS AFTERNOON...AROUND 21-22Z. MADE NO GRID UPDATES AT THIS TIME AS GOING FORECAST STILL REFLECTS CURRENT THINKING FOR THIS AFTERNOON. ..MAYES.. && .PREVIOUS DISCUSSION...ISSUED AT 400 AM... LATEST SFC/MSAS ANALYSIS WAS INDICATING MID TO UPPER 70 SFC DPT POOL ACRS MUCH OF CENTRAL INTO WESTERN IA IN AREA OF WEAK SFC CONVERGENCE. EVEN THE 11U-3.9U IR IMAGERY WAS PICKING UP ON THIS HIGH SFC MOISTURE LIKE LLVL STRATUS OR FOG. A STRENGTHENING FRONTAL BOUNDARY EXTENDED TO THE SOUTHWEST OF MAIN MN ARROWHEAD SFC WAVE ACRS WESTERN AND SOUTHWEST MN...SOUTHEAST SD AND ACRS CENTRAL NEB. STRENGTHENING INDICATED BY INCREASING PRESSURE RISES ACRS THE WESTERN DAKOTAS...AND SUPPORTS THE FURTHER SOUTHWARD PUSH OF THE BOUNDARY THAT MOST SHORT RANGE MODELS HAVE SUGGESTED FOR TWO NIGHTS IN A ROW NOW. THE MODELS MAINTAIN THIS POOL AS IT MIGRATES EAST INTO THE LOCAL AREA BY LATE MORNING AHEAD OF INCOMING FRONTAL PUSH...WITH THE GFS EVEN INCREASING VALUES TO THE LOW 80S BY AFTERNOON. ALTHOUGH THIS PROBABLY OVERDOING IT...EVEN CONSERVATIVE DPT VALUES OF 73 TO 76 DEGREES F COMBINED WITH AT LEAST MID 90 AMBIENT TEMPS SUPPORT HEAT INDICES OF 105 OR HIGHER FOR A LONG ENOUGH DURATION TO WARRANT A HEAT ADVISORY FOR ALL BUT THE FAR NORTHWEST QUARTER OF THE DVN CWA. FCST SOUNDINGS AND BETTER MIXING SCENARIO TODAY IN TIGHTENING GRADIENT AHEAD OF INCOMING FRONT...SUPPORT HIGHS MORE IN THE UPPER 90S AND POSSIBLY A TRIPLE DIGIT READING IN THE SOUTHWEST HALF OF THE FCST AREA...ESPECIALLY IF THE LLVL MOISTURE CAN MIX OUT SOME. THIS COULD MEAN CONDITIONS EVEN APPROACHING HEAT WARNING CRITERIA IF SFC DPTS MAINTAIN IN THE MID 70S. TRICKY FCST WITH THE BATTLE OF TEMPS TRYING TO WARM HIGHER BEING HINDERED BY ENHANCED BOUNDARY LAYER MOISTURE. WITH THE ONGOING WARM NIGHT TAKEN INTO ACCOUNT WITH MANY SITES HOLDING UP IN THE 75 TO 80 DEGREE RANGE...WILL ISSUE A HEAT ADVISORY FOR TODAY EXPECTING HIGHS IN THE MID TO UPPER 90S AND DPTS AT LEAST IN THE 73 TO 75 DEGREE RANGE IN ALL BUT THE NORTHWEST QUARTER OF THE DVN CWA. THE SECOND BIG CHALLENGE FOR TODAY/TONIGHT...IF CONVECTION CAN FIRE JUST UPSTREAM OR EVEN OVER THE LOCAL AREA LATER THIS AFTERNOON AS SFC BOUNDARY SAGS INTO EASTERN IA AND SOUTHWEST WI. TO KEEP THIS SHORT... A PLETHORA OF DEEP CONVECTION SPAWNING PARAMETERS BECOME OPTIMUM THIS AFTERNOON IN A POTENTIALLY EXPLOSIVE/VERY HIGH INSTABILITY-BUOYANT AIRMASS. CAPES OF 3-4 J/KG COULD BE DEEMED AS CONSERVATIVE/ESPECIALLY IF THE GFS HAS ITS WAY/...AND THERMODYNAMIC PROFILES/FCST SOUNDINGS ARE TROUBLING WITH VERTICAL THTA-E GRADIENT AND MIX DOWN POTENTIAL FOR A HIGH WIND EVENT. WITH WBZ'S QUITE A BIT LOWER THAN THE FREEZING LEVEL...AS STORMS FIRE LARGE HAIL WILL BE THE INITIAL THREAT..WITH THE EVOLUTION TO A DAMAGING WIND PRODUCING MCS PROPAGATING TO THE EAST AND SOUTHEAST TOWARD CENTRAL IL AS THE EVENING PROGRESSES. WORSE CASE SCENARIO IF HIGH TEMPS REACH THE UPPER 90S WITH SFC DPTS IN THE MID 70S BY LATE AFTERNOON BEFORE STORMS IGNITE...COULD MEAN DAMAGING WIND SWATHS OF 80-90 MPH OR EVEN HIGHER. OF COURSE...THIS AFTERNOON SVR CONVECTIVE POTENTIAL ALL HINGES ON IF STOUT CAP CAN BE OVERCOME BY A STRONG ENOUGH TRIGGER OR ERODE. BOTH THE GFS AND NAM-WRF DO WEAKEN CAP FROM THE NORTHWEST AS MID LEVEL FLOW VEERS...POSSIBLY ADVECTING ELEMENTS FROM UPSTREAM CONVECTION. UPPER FORCING BY DIVERGENT SOUTHERN EDGE OF NORTHERN STREAM JET AND NORTHERN PLAINS VORT GETTING STEERED RIGHT INTO THE AREA IN INCREASING NORTHWEST AND DIFFLUENT FLOW ALSO WILL HELP. WILL UP THE POPS TO HIGH CHANCE FOR NOW FORE THIS AFTERNOON AND TONIGHT... EXPECTING ACTION TO POSSIBLY START OFF IN THE WESTERN AND NORTHWEST CWA BY MID AFTERNOON...AND DEVELOP TO THE SOUTHEAST THRU THE EVENING. QUICK LOOK INTO TUE SUGGESTS GRT LKS HIGH SHUNTING MAIN BOUNDARY JUST TO THE SOUTH OF THE CWA BY TUE...WITH ENE FETCH MEANING COOLER AND LESS HUMID CONDITIONS FOR MUCH OF THE NORTHEAST 2/3'S OF THE DVN CWA. BEING IN THE VCNTY OF SFC FRONT...THE SOUTHERN CWA MAY STILL BE OPEN TO SOME CONVECTIVE ACTIVITY TOMORROW. AFTER THAT... LLVL REFOCUS FOR MCS DEVELOPMENT TAKES PLACE UPSTREAM TO THE NORTHWEST TUE NIGHT...WITH MEAN FLOW PATTERNS PROGGED BY MOST SHORT AND MEDIUM RANGE MODELS POSSIBLY ALLOWING THIS ACTIVITY TO MAKE IT INTO THE NORTHWESTERN CWA AS EARLY AS LATE TUE NIGHT-EARLY WED MORNING. ..12.. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...HEAT ADVISORY UNTIL 7PM MAINLY ALONG AND SOUTH OF ROUTE 30. IL...HEAT ADVISORY UNTIL 7PM. MO...HEAT ADVISORY UNTIL 7PM. && $$ MAYES ia AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 1035 AM CDT MON JUL 17 2006 .UPDATE... FORECAST FOR BOTH TEMPS AND CONVECTION THIS MORNING COMPLICATED BY ONGOING SHOWERS/THUNDERSTORMS ACROSS NORTHERN IA. SUBJECTIVE 12Z UPPER AIR ANALYSIS INDICATES 850MB MOISTURE TONGUE REACHING FROM THE TX/LA BORDER TO THE UPPER MS RIVER VALLEY... WITH 18C DEWPOINTS AS FAR NORTH AS KDVN. KDVN SOUDNING AND 700MB ANALYSIS INDICATE VERY DRY MID-LEVEL AIR... WITH MID-LEVEL WAVE DRAGGING SLIGHTLY COOLER MID-LEVEL TEMPS INTO NRN IA/SRN MN. BUSY 500MB ANALYSIS INDICATES TROUGH ACROSS NRN ONT INTO NRN MN... WITH SHORTWAVE ACROSS NRN IA. LARGE AREA OF 500MB HEIGHT FALLS ASSOCIATED WITH THE TROUGH AND SHORTWAVE INDICATE DEEPENING OF TROUGH AS IT PROGRESSES SOUTHEASTWARD AS WELL AS PROGRESSION OF SHORTWAVE ACROSS IA. SURFACE DEWPOINTS REMAIN IN THE 70S ACROSS THE AREA... WITH A FEW MID TO UPPER 70S AT RELIABLE SITES. WHILE SHRA/TSRA COMPLEX AS A WHOLE IS WEAKENING /PER IR SATELLITE TRENDS OF WARMING TOPS...DIMINISHING LIGHTNING...AND RADAR APPEARANCE/ CORES WITHIN THE COMPLEX ARE STILL SURVIVING. ACTIVITY IS OUTRUNNING ELEVATED INSTABILITY AXIS PER RUC ANALYSIS FIELDS... AS WELL AS SHORTWAVE SUPPORT AND 850MB BOUNDARY. SHRA/TSRA SHOULD CONTINUE AT LEAST INTO THE NRN TIER OF IA COUNTIES OVER THE NEXT COUPLE OF HOURS EVEN AS THE ACTIVITY WEAKENS. CLOUDS AND SHOWERS WILL KEEP TEMPS LOWER BENEATH...AND HAVE KNOCKED A COUPLE OF DEGREES OFF IN NRN IA. HAVE ALSO BUMPED UP TEMPS A COUPLE OF DEGREES IN THE SOUTHWEST WHERE TEMPS LOOK LIKE THEY CAN EASILY APPROACH 100 GIVEN 90 DEGREE READINGS AT 10AM. CONVECTIVE POTENTIAL LATER THIS AFTERNOON INTO THE EVENING REMAINS AN ISSUE. EXPECT DYING ACTIVITY TO DO NOT MUCH MORE THAN CREATE A STRONGER TEMP GRADIENT ACROSS THE CWA AS WINDS BEHIND IT HAVE ALREADY RECOVERED TO SWLY. POTENTIAL RELIES HEAVILY ON CAP...AS ANY ACTIVITY THAT DOES DEVELOP WOULD LIKELY BECOME SEVERE GIVEN STRONG INSTABILITY /3000-4000 J/KG CONSERVATIVELY/ AND ADEQUATE SHEAR ALONG WITH SHORTWAVE PROMOTING LARGER-SCALE LIFT. DRY MID-LEVEL AIR WILL BOTH AID HAIL DEVELOPMENT AND INCREASE WIND POTENTIAL IN STORMS THAT DO DEVELOP. CAP STRENGTH WILL RELY ON ADVECTION OF COLDER 800-700MB AIR ASSOCIATED WITH THE NRN IA SHORTWAVE. WILL RELEASE A SOUNDING AT 20Z TO INVESTIGATE CAP. ..MAYES.. && .PREVIOUS DISCUSSION...ISSUED AT 400 AM... LATEST SFC/MSAS ANALYSIS WAS INDICATING MID TO UPPER 70 SFC DPT POOL ACRS MUCH OF CENTRAL INTO WESTERN IA IN AREA OF WEAK SFC CONVERGENCE. EVEN THE 11U-3.9U IR IMAGERY WAS PICKING UP ON THIS HIGH SFC MOISTURE LIKE LLVL STRATUS OR FOG. A STRENGTHENING FRONTAL BOUNDARY EXTENDED TO THE SOUTHWEST OF MAIN MN ARROWHEAD SFC WAVE ACRS WESTERN AND SOUTHWEST MN...SOUTHEAST SD AND ACRS CENTRAL NEB. STRENGTHENING INDICATED BY INCREASING PRESSURE RISES ACRS THE WESTERN DAKOTAS...AND SUPPORTS THE FURTHER SOUTHWARD PUSH OF THE BOUNDARY THAT MOST SHORT RANGE MODELS HAVE SUGGESTED FOR TWO NIGHTS IN A ROW NOW. THE MODELS MAINTAIN THIS POOL AS IT MIGRATES EAST INTO THE LOCAL AREA BY LATE MORNING AHEAD OF INCOMING FRONTAL PUSH...WITH THE GFS EVEN INCREASING VALUES TO THE LOW 80S BY AFTERNOON. ALTHOUGH THIS PROBABLY OVERDOING IT...EVEN CONSERVATIVE DPT VALUES OF 73 TO 76 DEGREES F COMBINED WITH AT LEAST MID 90 AMBIENT TEMPS SUPPORT HEAT INDICES OF 105 OR HIGHER FOR A LONG ENOUGH DURATION TO WARRANT A HEAT ADVISORY FOR ALL BUT THE FAR NORTHWEST QUARTER OF THE DVN CWA. FCST SOUNDINGS AND BETTER MIXING SCENARIO TODAY IN TIGHTENING GRADIENT AHEAD OF INCOMING FRONT...SUPPORT HIGHS MORE IN THE UPPER 90S AND POSSIBLY A TRIPLE DIGIT READING IN THE SOUTHWEST HALF OF THE FCST AREA...ESPECIALLY IF THE LLVL MOISTURE CAN MIX OUT SOME. THIS COULD MEAN CONDITIONS EVEN APPROACHING HEAT WARNING CRITERIA IF SFC DPTS MAINTAIN IN THE MID 70S. TRICKY FCST WITH THE BATTLE OF TEMPS TRYING TO WARM HIGHER BEING HINDERED BY ENHANCED BOUNDARY LAYER MOISTURE. WITH THE ONGOING WARM NIGHT TAKEN INTO ACCOUNT WITH MANY SITES HOLDING UP IN THE 75 TO 80 DEGREE RANGE...WILL ISSUE A HEAT ADVISORY FOR TODAY EXPECTING HIGHS IN THE MID TO UPPER 90S AND DPTS AT LEAST IN THE 73 TO 75 DEGREE RANGE IN ALL BUT THE NORTHWEST QUARTER OF THE DVN CWA. THE SECOND BIG CHALLENGE FOR TODAY/TONIGHT...IF CONVECTION CAN FIRE JUST UPSTREAM OR EVEN OVER THE LOCAL AREA LATER THIS AFTERNOON AS SFC BOUNDARY SAGS INTO EASTERN IA AND SOUTHWEST WI. TO KEEP THIS SHORT... A PLETHORA OF DEEP CONVECTION SPAWNING PARAMETERS BECOME OPTIMUM THIS AFTERNOON IN A POTENTIALLY EXPLOSIVE/VERY HIGH INSTABILITY-BUOYANT AIRMASS. CAPES OF 3-4 J/KG COULD BE DEEMED AS CONSERVATIVE/ESPECIALLY IF THE GFS HAS ITS WAY/...AND THERMODYNAMIC PROFILES/FCST SOUNDINGS ARE TROUBLING WITH VERTICAL THTA-E GRADIENT AND MIX DOWN POTENTIAL FOR A HIGH WIND EVENT. WITH WBZ'S QUITE A BIT LOWER THAN THE FREEZING LEVEL...AS STORMS FIRE LARGE HAIL WILL BE THE INITIAL THREAT..WITH THE EVOLUTION TO A DAMAGING WIND PRODUCING MCS PROPAGATING TO THE EAST AND SOUTHEAST TOWARD CENTRAL IL AS THE EVENING PROGRESSES. WORSE CASE SCENARIO IF HIGH TEMPS REACH THE UPPER 90S WITH SFC DPTS IN THE MID 70S BY LATE AFTERNOON BEFORE STORMS IGNITE...COULD MEAN DAMAGING WIND SWATHS OF 80-90 MPH OR EVEN HIGHER. OF COURSE...THIS AFTERNOON SVR CONVECTIVE POTENTIAL ALL HINGES ON IF STOUT CAP CAN BE OVERCOME BY A STRONG ENOUGH TRIGGER OR ERODE. BOTH THE GFS AND NAM-WRF DO WEAKEN CAP FROM THE NORTHWEST AS MID LEVEL FLOW VEERS...POSSIBLY ADVECTING ELEMENTS FROM UPSTREAM CONVECTION. UPPER FORCING BY DIVERGENT SOUTHERN EDGE OF NORTHERN STREAM JET AND NORTHERN PLAINS VORT GETTING STEERED RIGHT INTO THE AREA IN INCREASING NORTHWEST AND DIFFLUENT FLOW ALSO WILL HELP. WILL UP THE POPS TO HIGH CHANCE FOR NOW FORE THIS AFTERNOON AND TONIGHT... EXPECTING ACTION TO POSSIBLY START OFF IN THE WESTERN AND NORTHWEST CWA BY MID AFTERNOON...AND DEVELOP TO THE SOUTHEAST THRU THE EVENING. QUICK LOOK INTO TUE SUGGESTS GRT LKS HIGH SHUNTING MAIN BOUNDARY JUST TO THE SOUTH OF THE CWA BY TUE...WITH ENE FETCH MEANING COOLER AND LESS HUMID CONDITIONS FOR MUCH OF THE NORTHEAST 2/3'S OF THE DVN CWA. BEING IN THE VCNTY OF SFC FRONT...THE SOUTHERN CWA MAY STILL BE OPEN TO SOME CONVECTIVE ACTIVITY TOMORROW. AFTER THAT... LLVL REFOCUS FOR MCS DEVELOPMENT TAKES PLACE UPSTREAM TO THE NORTHWEST TUE NIGHT...WITH MEAN FLOW PATTERNS PROGGED BY MOST SHORT AND MEDIUM RANGE MODELS POSSIBLY ALLOWING THIS ACTIVITY TO MAKE IT INTO THE NORTHWESTERN CWA AS EARLY AS LATE TUE NIGHT-EARLY WED MORNING. ..12.. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...HEAT ADVISORY UNTIL 7PM MAINLY ALONG AND SOUTH OF ROUTE 30. IL...HEAT ADVISORY UNTIL 7PM. MO...HEAT ADVISORY UNTIL 7PM. && $$ MAYES ia AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1045 AM EDT MON JUL 17 2006 .UPDATE...12Z SURFACE ANALYSIS SHOWS COLD FRONT LYING ACROSS WESTERN LAKE SUPERIOR/NORTHWEST WI/SOUTHERN MN...4-5MB/3H PRESSURE RISES BEHIND THE BOUNDARY ACROSS NORTHERN MN HELPING PUSH THINGS ALONG. 12Z APX SOUNDING SHOWING DRY ELEVATED MIXED LAYER CHARACTERISTICS WITH A NEARLY DRY ADIABATIC LAYER 800-500MB. LOW LEVEL MOIST LAYER JUST BELOW 850MB (WITH OBSERVED 850MB DEW POINT/DEW POINT DEPRESSION OF -6C/28C RESPECTIVELY). SOUNDING IS CAPPED OFF IN THE 850-800MB LAYER...AND THE PROBLEM FOR THIS AFTERNOON IS THAT IT IS GOING TO REQUIRE SOME WORK TO OVERCOME THIS. MODIFIED APX SOUNDING FOR 91/66 YIELDS IMPRESSIVE MLCAPE OVER 3300 J/KG...AND A CINH OF NEARLY 150 J/KG (A 92/71 PARCEL CUTS THE CINH IN HALF). GRB 12Z SOUNDING SIMILAR...93/73 PARCEL YIELDS MLCAPE NEARLY 4500 J/KG...AND MLCINH 150 J/KG. WATER VAPOR IMAGERY SHOWS WELL DEFINED SHORT WAVE TROUGH CROSSING WI...THIS CERTAINLY WON'T HURT THE CAUSE IN TERMS OF PROVIDING SOME LIFT TO HELP WEAKEN INVERSION...THOUGH A GOOD DEAL OF CLOUD COVER OUT AHEAD OF IT (MOSTLY HIGH BASED AC/ACCAS) COULD PUT A BIT OF A DAMPER ON HEATING. GFS/NAM FORECASTS FROM THIS MORNING DID SHOW A GOOD 2-3C COOLING AT 700MB THIS AFTERNOON...SOMEWHAT INTERESTING GIVEN DRY ADIABATIC NATURE OF OBSERVED APX SOUNDING (LIFTING A DRY ADIABATIC LAYER DRY ADIABATICALLY ISN'T GOING TO TIP THE LAPSE RATE ANY MORE UNSTABLE). NAM ALSO A GOOD 4C COLDER AT 12Z THAN OBSERVED IN THE 850-625MB LAYER. RUC SOUNDINGS PROBABLY MORE REALISTIC IN KEEPING MID LEVEL TEMPERATURES WARM THROUGH THE AFTERNOON...BUT DOES SHOW SOME WEAKENING OF THE LOW LEVEL CAP (MODIFIED RUC SOUNDINGS FOR 90/70 SHOW CINH DROPPING CLOSER TO 60 J/KG). COLD FRONT WILL PUSH INTO EASTERN UPPER BY MID AFTERNOON... THEN SWEEP THROUGH NORTHERN LOWER BY MID TO LATE EVENING. SO JUST A MATTER OF PLAYING THE WAITING GAME NOW...IF LOW LEVEL CAP CAN WEAKEN WITH FORCING AND DEW POINTS CAN REMAIN IN THE UPPER 60S/ NEAR 70 PROSPECTS FOR CONVECTION WILL IMPROVE GREATLY. IF/WHEN THINGS START TO GO IT SHOULD BE POTENTIALLY PRETTY EXPLOSIVE GIVEN ALL THE ENERGY STORED UP IN THE LOWER LAYERS. WILL BE SENDING UP AN 18Z SOUNDING TO MONITOR CAP BEHAVIOR. HIGH INSTABILITY WILL STILL PROVIDE A GOOD HAIL THREAT DESPITE HIGH FREEZING LEVELS (ABOVE 14K FEET)...0-6KM SHEAR VALUES OF 30-40KTS MARGINALLY SUPPORTIVE OF STORM ROTATION. OF MORE IMPORTANCE STEEP MID LEVEL LAPSE RATES/DRY AIR RELATED TO ELEVATED MIXED LAYER...COMBINED WITH UNIDIRECTIONAL WIND PROFILES ALOFT WILL CREATE SIGNIFICANT DAMAGING WIND POTENTIAL. JPB && .PREV DISCUSSION...ISSUED 434 AM EDT MON JUL 17. SFC/RUC/SATELLITE/RADAR AND UPPER AIR ANALYSIS SHOWING FLAT UPPER RIDGE OVER THE SRN TWO-THIRDS OF THE COUNTRY WEST OF THE OHIO RIVER VALLEY...WHILE BRISK WESTERLY FLOW TRAVERSED THE NRN THIRD. SHORTWAVE IS CURRENTLY DROPPING THROUGH SRN MANITOBA WHILE EMBEDDED WEAKER/MORE DIFFICULT TO DISTINGUISH WAVES ARE WORKING ACROSS SD...SE MN...AND LAKE SUPERIOR. IN THE MID LEVELS...WARM AIR AROUND 700MB NEAR +13C (PER ACARS/TAMDAR SOUNDINGS AT 03Z)...BUT LAPSE RATES ABOVE THIS WARM AIR (H7-H5) ARE VERY STEEP...AT 7.5-8 C/KM. MOISTURE AT H7 IS RATHER SCANT...WITH ONLY A FEW SITES REPORTING SOME SCATTERED 10KFT CLOUD. THERE IS A BETTER COVERAGE OF HIGHER LEVEL CLOUDS ACROSS WISCONSIN...WHILE EARLIER CONVECTION FROM NE MN HAS LEFT SOME SCT-BKN 6KFT MOISTURE ACROSS EASTERN LAKE SUPERIOR. NRN MICHIGAN WAS ON THE LEFT/TAIL END OF ONE DEPARTING 40KT H8 LLJ NOSING ACROSS SRN LAKE HURON WHICH IS TAKING WITH IT SOME OF THE HIGHER H8 TD VALUES AROUND +15C...WHILE SECOND 35-40KT LLJ IS POINTING INTO SW ONTARIO POOLING +16C H8 TD AIR INTO THE ARROWHEAD OF MN. THIS LATTER LLJ IS JUST AHEAD OF A SFC LOW PRESSURE OVER INTERNATIONAL FALLS...WHICH HAS A TRAILING COLD FRONT WORKING DOWN INTO THE DAKOTAS. EAST OF THE LOW...WARM FRONT SEEN JUST NORTH OF THE WESTERN PORTION OF LAKE SUPERIOR...WHICH THEN TURNS INTO MORE OF A STATIONARY BOUNDARY DRAPED ACROSS FAR SRN ONTARIO. MID LEVEL WINDS WERE 35-45KTS ACROSS EASTERN UPPER (25-35KTS NRN LOWER)...WITH 0-6KM BULK SHEAR VALUES OF 40-50KTS EASTERN UPPER (20-30KTS NRN LOWER). TEMPS WERE VERY WARM WITH 70S AND LOW 80S ACROSS THE REGION AND GENERALLY LIGHT SW FLOW UNDER 10 KTS...WITH SOME GUSTINESS OVER THE LAKES. FORECAST CONCERNS...THUNDERSTORM AND SEVERE POTENTIAL INTO EARLY THIS EVENING WITH THE APPROACH OF THE COLD FRONT...AND MARINE WIND AND WAVES THROUGH ALL OF TONIGHT FOR THE NEARSHORE AREAS. THEN... AFTER A BEAUTIFUL TUESDAY/TUESDAY NIGHT...MOISTURE AND INSTABILITY RETURNS WEDNESDAY AND MAINLY WEDNESDAY NIGHT FOR THUNDERSTORM CHANCES. TODAY...WITH DEPARTING LLJ AND BETTER H8 MOISTURE...WARM H7 TEMPS CAPPING THE ATMOSPHERE...AND GREATEST FORCING WELL TO OUR WEST... FEEL THAT WE WILL NOT HAVE TO BE DEALING WITH SHOWERS AND THUNDERSTORMS RIGHT OFF THE BAT THIS MORNING. THIS EVEN THOUGH LAPSE RATES ARE SO STEEP...MOISTURE AND LIFT ARE JUST NOT QUITE THERE. COULD MAYBE SEE A FEW STRAY SHOWERS MOVING THROUGH FAR NE LOWER AND EASTERN UPPER. WILL GO WITH AN EARLY MORNING ISOLATED WORDING. LOOKS LIKE FRONTAL PASSAGE HAS BEEN DELAYED BY A COUPLE HOURS. SFC COLD FRONT NOW DEPICTED TO ROLL THROUGH EASTERN UPPER AROUND 18Z...THEN NRN LOWER BY 02Z. WITH WHAT LOOKS LIKE MINIMAL CLOUDINESS TO START OFF THE DAY...HEATING CAN BECOME FAIRLY INTENSE...PARTICULARLY FOR NRN LOWER. WITH H8 TEMPS IN THE 20-22C RANGE...HIGHS WILL TOP OUT TO ONLY THE MIDDLE 80S EASTERN UPPER (FRONT EARLIER) TO AS WARM AS THE MIDDLE 90S ACROSS SE SECTIONS OF NRN LOWER. MODIFYING SOUNDINGS WITH THESE TEMPS...AND SFC TD'S IN THE MIDDLE AND UPPER 60S POOLING ALONG THE FRONT...YIELD 2500 J/KG MLCAPE NEAR THE THUMB WITH 2000J/KG IN EASTERN UPPER. BIG QUESTION FOR EASTERN UPPER WILL BE WHETHER OR NOT TEMPS CAN GET WARM ENOUGH TO ELIMINATE AN ESTIMATED 70 J/KG OF CAP AT FRONTAL PASSAGE TIME...OR WILL THE FRONT/SHORTWAVE FORCING (5-10 UNITS H8-H5 -DIVQ) AND WARMING TEMPS COMBINATION BY ENOUGH. WITH ALL OF THE SYNOPTIC FEATURES IN PLAY AND SLOWER FRONTAL PASSAGE...HAVE TO BELIEVE IN THE LATTER SCENARIO HERE. WITH SFC LOW DEEPENING WITH TIME...AND FRONT REACHING THE SE CWA AT PEAK HEATING...AM EXPECTING SHOWERS AND THUNDERSTORMS TO NOT ONLY DEVELOP ALONG THE SFC COLD FRONT...BUT EXPAND IN COVERAGE THROUGH THE AFTERNOON AND EARLY EVENING. 0-6 AND 0-3KM BULK SHEAR BETWEEN 35 AND 40 KTS WITH MID LEVEL WINDS AT 40-50KTS AND FAIRLY UNIDIRECTIONAL FLOW...LEADING TO LINEAR STORM TYPE WITH EMBEDDED SUPERCELLS AND POSSIBLE BOW ECHOES. WILL HIGHLIGHT DAMAGING WINDS AND LARGE HAIL IN THE HWOAPX. TONIGHT...STORMS SHOULD BE WELL DEVELOPED SOUTH OF M-32 BY EARLY THIS EVENING...AND CONTINUING TO TRACK SOUTH ALONG WITH THE SFC COLD FRONT. SEVERE WEATHER CHANCES WILL PERSIST INTO THE EARLY TO LATE EVENING AS STORMS EXIT THE THUMB REGION AROUND 10 PM. BEHIND THE COLD FRONT...H8-H5 THETA-E DROPS TO 312K UNDER DRYING AND SUBSIDENCE. WOULD FULLY EXPECT SKIES TO BECOME MOSTLY CLEAR MANY AREAS OVERNIGHT...ESPECIALLY EASTERN UPPER/FAR NRN LOWER. AIR MASS WILL FEEL MUCH DIFFERENT THAN THE ONE WE ARE IN NOW. COOLER LOWS WITH READINGS DIPPING TO THE 50S MOST AREAS...WITH LOWER 60S NEARER THE THUMB. TUESDAY AND TUESDAY NIGHT...WONDERFUL WEATHER HERE. DRY AIR MASS IN PLACE WITH SFC HIGH PRESSURE SWEEPING THROUGH THE REGION. MAYBE SOME AFTERNOON SCATTERED CUMULUS WITH A TOUCH OF HIGH LEVEL CIRRUS. SO MOSTLY SUNNY AND PRECIP FREE. HIGHS TUESDAY WILL BE IN THE LOW TO MID 80S WITH NIGHTTIME LOWS IN THE 50S. WEDNESDAY...TRANSITION DAY. SFC HIGH DEPARTS TO THE EAST AND RETURN SOUTHERLY FLOW COMMENCES. H8 TEMPS CREEP BACK UP INTO THE MID TO UPPER TEENS. THIS WILL RESULT IN MID TO UPPER 80S NRN LOWER LOW TO MID 80S EASTERN UPPER. THERE WILL BE SOME LATE DAY THETA-E ADVECTION ARRIVING FROM THE WEST AHEAD OF NEXT LOW PRESSURE/COLD FRONT THAT WILL BE WORKING INTO THE UPPER MISSISSIPPI VALLEY...BUT AIR MASS WILL BE QUITE DRY INITIALLY. WITH SYNOPTIC FEATURES WELL WEST OF NRN MICHIGAN...SHOULD BE A PRECIP-FREE DAY. THEREFORE...HAVE REMOVED ALL BUT WESTERN CHIP/MACK FROM 30% CHANCE OF THUNDERSTORMS. COULD VERY WELL SEE THIS FINAL CHANCE ELIMINATED IF PATTERN HOLDS. WEDNESDAY NIGHT AND THURSDAY...DECENT SHORTWAVE TROUGH DIGS INTO WESTERN LAKE SUPERIOR AND SFC FRONT MAKES IT INTO THE AREA BY 12Z. LLJ OF 30-40KTS DRAPES ACROSS CENTRAL LOWER AND THETA-E ADVECTION IS MAXIMIZED OVERNIGHT FOR BEST CHANCE OF SHOWERS AND STORMS. THIS CONVECTION LOOKS TO CONTINUE INTO THURSDAY MORNING...FOR MAINLY NRN LOWER. KEPT A SMALL CHANCE FOR REMNANT ACTIVITY THURSDAY NIGHT DUE TO LOWER CONFIDENCE WITH THE TIMING ISSUES...BUT COULD SEE THIS PERIOD BEING DRY AS WELL...IF PATTERN HOLDS. NO OTHER CHANGES TO THE FORECAST. SMD && .APX...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GLASGOW MT 907 PM MDT MON JUL 17 2006 .SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT... A LARGE SUB-TROPICAL RIDGE CONTINUES TO COVER THE SOUTHERN 4/5'S OF THE UNITED STATES FROM COAST TO COAST. 500MB HEIGHTS ARE ABOUT AS HIGH AS THEY GET...AROUND 600 DAM IN COLORADO. NORTHEAST MONTANA IS ON THE NORTHERN PERIPHERY OF THE RIDGE MEANING THAT SOME DISTURBANCES AND FRONTS ARE ABLE TO WORK ACROSS THE AREA FROM TIME TO TIME. CURRENTLY A SURFACE RIDGE COVERS THE DAKOTAS AND IT CONTINUES TO WEAKEN AND SLIDE OFF TO THE SOUTHEAST. A SURFACE TROUGH IS EVIDENT ACROSS CENTRAL MONTANA FROM ABOUT HAVRE SOUTH TO LIVINGSTON. THE SURFACE TROUGH HAS MOVED LITTLE DURING THE HEAT OF THE DAY...BUT SHOULD START TO MAKE SOME PROGRESS TO THE EAST TONIGHT AS AN UPPER TROUGH VISIBLE ON WATER VAPOR IN WESTERN ALBERTA CONTINUES TO PUSH OFF TO THE EAST. ALSO WATCHING AN AREA OF CONVECTION MOVING OUT OF FERGUS COUNTY AND INTO PETROLEUM COUNTY. IT LOOKS TO BE HOLDING TOGETHER WELL AND WILL ADD SOME DRY THUNDERSTORMS WITH GUSTY WIND INTO OUR SOUTHWEST ZONES FOR THE REMAINDER OF THE EVENING. PLAN TO PUSH UP THE START TIME OF THE RED FLAG WARNING ACROSS THE WESTERN DISTRICTS AS THE WIND WILL LIKELY BECOME GUSTY ACROSS THE HIGHER TERRAIN ONCE THE SURFACE TROUGH PUSHES IN LATER TONIGHT. ESPECIALLY AS THERE ARE SEVERAL ONGOING LARGE FIRES ACROSS THIS AREA WITH NUMEROUS FIRE CREWS IN THE AREA. ALL OF THE PRODUCT UPDATES HAVE ALREADY BEEN SENT OUT. CB ...PREVIOUS SHORT TERM... GOOD MODEL CONTINUITY AND AGREEMENT FOR FORECAST PERIOD...USED BLEND OF GFS AND NAM BUT WEIGHTED NAM A BIT MORE...ESPECIALLY BY USING NAM WINDS TO INITIALIZE WIND GRIDS. TONIGHT...MODELS SHOW A WEAK AND DRY SHORT WAVE TROUGH CROSSING FORECAST AREA LATE TONIGHT AND EARLY TUESDAY MORNING. NONE OF THE MODELS SHOW ANY PRECIPITATION...BUT RUC AND NAM SHOW BAND OF SLIGHTLY NEGATIVE 850MB LI/S AND POSITIVE OMEGA PROGRESSING ACROSS SOUTH AND ESPECIALLY SOUTHEAST ZONES LATE TONIGHT...SUPPORTING SLIGHT RISK OF DRY THUNDERSTORMS AFTER MIDNIGHT. FAVOR SOUTHEAST ZONES FOR GREATER...ALBEIT LOW...RISK OF ANY DRY THUNDERSTORMS DUE TO PRESENCE OF MODERATE LOW LEVEL JET IN 900MB TO 850MB LAYER OVER SOUTHEAST ZONES BUT NOT FURTHER WEST NOR FURTHER NORTH. SURFACE REFLECTION OF LOW LEVEL JET ACROSS MAINLY SOUTHEAST ZONES. HELD MINIMA SLIGHTLY ABOVE MOS GUIDANCE PER RECENT TREND FAVORING WARMER TEMPERATURES THAN GUIDANCE. TUESDAY...COOL FRONT EXITS INTO NORTH DAKOTA DURING EARLY MORNING WITH WINDS SHIFTING WEST TO NORTHWEST AND INCREASING DUE TO INCREASED MIXING THROUGH DAY WITH DIURNAL WARMING. WINDS BECOME GUSTY DURING AFTERNOON AS MID LEVEL WINDS MIX DOWN...HAVE BEEN SOMEWHAT CONSERVATIVE IN GUST SPEEDS...BUT LAST MINUTE GLANCE AT 18Z NAM SUGGESTS STRONGER 700MB WINDS THAN PREVIOUS...WILL NEED TO MONITOR FOR POSSIBLE INCREASE OF WIND SPEEDS AND GUSTS. THICKNESSES FALL SLIGHTLY FROM MONDAY...BUT STRONG MIXING EXPECTED TO KEEP TEMPERATURES SLIGHTLY ABOVE MOS GUIDANCE. TUESDAY NIGHT AND WEDNESDAY...SURFACE HIGH PRESSURE SETTLES ACROSS FORECAST AREA...RELAXING PRESSURE GRADIENT AND BRINGING SLIGHT COOLING. CONTINUED TO GO ABOVE MOS GUIDANCE BUT OVERALL COOLER THAN RECENT DAYS. .LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY... DRY CONDITIONS ARE EXPECTED TO CONTINUE WHILE A SLIGHT WARMING TREND OCCURS DURING THE EARLY PART OF THIS PERIOD AS MAX TEMPS ARE EXPECTED TO REBOUND WELL INTO THE 90S BY FRIDAY. WINDS LOOK TO BE LIGHT AS SURFACE HIGH PRESSURE SURGES FROM THE NORTHWEST LOOK UNLIKELY. -TFJ PREVIOUS DISCUSSION... ALTHO THE MODELS ARE STRUGGLING SOMEWHAT WITH DETAILS FOR LATER THIS WEEK AND NEXT WEEKEND...THEY ARE MORE OR LESS POINTING TO THE UPPER PATTERN CHANGING FROM ONE OF A BROAD UPPER RIDGE COVERING MUCH OF THE CONUS TO ONE MORE LIKE A WEEK OR SO AGO WITH AN EAST COAST TROF AND A WESTERN RIDGE. ROUNDABOUT THURSDAY AS THE TROF IS EXPECTED TO DIG IN THE EAST WE MAY EXPERIENCE SOME BRIEF COOLING UNDER NORTHWEST FLOW ALOFT. HOWEVER AS THE RIDGE THEN BUILDS IN THE WEST AND THE PATTERN BECOMES MORE AMPLIFIED WE SHOULD HAVE TEMPERATURES RISE AGAIN FOR NEXT WEEKEND. NOT SEEING ANYTHING IN THIS PATTERN THAT WOULD LEND ITSELF TO ANY SIGNIFICANT PRECIPITATION...AND WOULD BE VERY UNLIKELY TO BELIEVE IT ANYWAY GIVEN THE DRYNESS OF THE PATTERN OVER THE LAST SEVERAL WEEKS. SO WILL RIDE ALONG WITH PERSISTENCE AND KEEP THINGS DRY. APPEARS FIRE WEATHER WILL REMAIN OF PRIMARY CONCERN THRU THIS EXTENDED PERIOD. && .AVIATION... VFR. EAST WIND INCREASING TO 15 TO 20 KT AT KGGW TONIGHT WITH LIGHTER SPEEDS AT THE OTHER SITES. A COLD FRONT MOVING THROUGH THE AREA TUESDAY MORNING...FROM ABOUT 7 AM TO NOON...WILL ALLOW WINDS TO SWITCH AND INCREASE FROM THE NORTHWEST AT SPEEDS OF 15 TO 25 KTS BY THE AFTERNOON. -TFJ && .FIRE WEATHER... PUSHED UP THE START TIME OF THE RED FLAG WARNING ACROSS THE WESTERN DISTRICTS AS IT APPEARS THE COLD FRONT/SURFACE TROUGH WILL PUSH INTO THE WESTERN DISTRICTS A BIT SOONER. LOW HUMIDITIES AND STRONG GUSTY WINDS ARE STILL EXPECTED TUESDAY. EXPECT WINDS TO INCREASE LATE TONIGHT ACROSS THE WESTERN DISTRICTS...AND BY MID-MORNING ACROSS THE EASTERN DISTRICTS. THE STRONG WIND WILL PERSIST THROUGH EARLY EVENING WITH BEST POTENTIAL FOR STRONG GUSTS DURING AFTERNOON. MIXING OF MID LEVEL WINDS PLUS INHERENTLY DRY AIRMASS WILL ALLOW MINIMUM HUMIDITIES TO FALL INTO TEENS THROUGH AFTERNOON. && .CLIMATE... THERE HAVE BEEN 13 DAYS IN A ROW WITH A HIGH TEMPERATURE OF 90 OR ABOVE IN GLASGOW. THIS IS THE LONGEST STREAK SINCE 1958. THE ALL- TIME RECORD IS 20 CONSECUTIVE DAYS SET BACK IN 1936. SHOULD EASILY REACH 14 DAYS IN A ROW OVER 90...BUT NOW APPEARS A GOOD CHANCE THERE WILL BE ONE DAY THIS WEEK...WEDNESDAY...THAT WON'T QUITE REACH 90. SO FAR THIS MONTH THERE HAVE BEEN 3 DAYS WITH A HIGH TEMPERATURE ABOVE 100 DEGREES. THE AVERAGE TEMPERATURE SO FAR THIS MONTH OF 76.5 DEGREES IS 7.3 DEGREES ABOVE NORMAL. IT IS THE WARMEST START TO THE MONTH OF JULY SINCE 1947. && .GLASGOW WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM 9 AM TO 9 PM MDT TUESDAY FOR MTZ120-MTZ122. RED FLAG WARNING FROM 4 AM TO 9 PM MDT TUESDAY FOR MTZ119-MTZ121. LAKE WIND ADVISORY FROM 9 AM TO 9 PM MDT TUESDAY FOR FORT PECK LAKE. && $$ WEATHER.GOV/GLASGOW mt AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GLASGOW MT 249 PM MDT MON JUL 17 2006 .SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH WEDNESDAY... GOOD MODEL CONTINUITY AND AGREEMENT FOR FORECAST PERIOD...USED BLEND OF GFS AND NAM BUT WEIGHTED NAM A BIT MORE...ESPECIALLY BY USING NAM WINDS TO INITIALIZE WIND GRIDS. TONIGHT...MODELS SHOW A WEAK AND DRY SHORT WAVE TROUGH CROSSING FORECAST AREA LATE TONIGHT AND EARLY TUESDAY MORNING. NONE OF THE MODELS SHOW ANY PRECIPITATION...BUT RUC AND NAM SHOW BAND OF SLIGHTLY NEGATIVE 850MB LI/S AND POSITIVE OMEGA PROGRESSING ACROSS SOUTH AND ESPECIALLY SOUTHEAST ZONES LATE TONIGHT...SUPPORTING SLIGHT RISK OF DRY THUNDERSTORMS AFTER MIDNIGHT. FAVOR SOUTHEAST ZONES FOR GREATER...ALBEIT LOW...RISK OF ANY DRY THUNDERSTORMS DUE TO PRESENCE OF MODERATE LOW LEVEL JET IN 900MB TO 850MB LAYER OVER SOUTHEAST ZONES BUT NOT FURTHER WEST NOR FURTHER NORTH. SURFACE REFLECTION OF LOW LEVEL JET ACROSS MAINLY SOUTHEAST ZONES. HELD MINIMA SLIGHTLY ABOVE MOS GUIDANCE PER RECENT TREND FAVORING WARMER TEMPERATURES THAN GUIDANCE. TUESDAY...COOL FRONT EXITS INTO NORTH DAKOTA DURING EARLY MORNING WITH WINDS SHIFTING WEST TO NORTHWEST AND INCREASING DUE TO INCREASED MIXING THROUGH DAY WITH DIURNAL WARMING. WINDS BECOME GUSTY DURING AFTERNOON AS MID LEVEL WINDS MIX DOWN...HAVE BEEN SOMEWHAT CONSERVATIVE IN GUST SPEEDS...BUT LAST MINUTE GLANCE AT 18Z NAM SUGGESTS STRONGER 700MB WINDS THAN PREVIOUS...WILL NEED TO MONITOR FOR POSSIBLE INCREASE OF WIND SPEEDS AND GUSTS. THICKNESSES FALL SLIGHTLY FROM MONDAY...BUT STRONG MIXING EXPECTED TO KEEP TEMPERATURES SLIGHTLY ABOVE MOS GUIDANCE. TUESDAY NIGHT AND WEDNESDAY...SURFACE HIGH PRESSURE SETTLES ACROSS FORECAST AREA...RELAXING PRESSURE GRADIENT AND BRINGING SLIGHT COOLING. CONTINUED TO GO ABOVE MOS GUIDANCE BUT OVERALL COOLER THAN RECENT DAYS. .LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY... DRY CONDITIONS ARE EXPECTED TO CONTINUE WHILE A SLIGHT WARMING TREND OCCURS DURING THE EARLY PART OF THIS PERIOD AS MAX TEMPS ARE EXPECTED TO REBOUND WELL INTO THE 90S BY FRIDAY. WINDS LOOK TO BE LIGHT AS SURFACE HIGH PRESSURE SURGES FROM THE NORTHWEST LOOK UNLIKELY. -TFJ PREVIOUS DISCUSSION... ALTHO THE MODELS ARE STRUGGLING SOMEWHAT WITH DETAILS FOR LATER THIS WEEK AND NEXT WEEKEND...THEY ARE MORE OR LESS POINTING TO THE UPPER PATTERN CHANGING FROM ONE OF A BROAD UPPER RIDGE COVERING MUCH OF THE CONUS TO ONE MORE LIKE A WEEK OR SO AGO WITH AN EAST COAST TROF AND A WESTERN RIDGE. ROUNDABOUT THURSDAY AS THE TROF IS EXPECTED TO DIG IN THE EAST WE MAY EXPERIENCE SOME BRIEF COOLING UNDER NORTHWEST FLOW ALOFT. HOWEVER AS THE RIDGE THEN BUILDS IN THE WEST AND THE PATTERN BECOMES MORE AMPLIFIED WE SHOULD HAVE TEMPERATURES RISE AGAIN FOR NEXT WEEKEND. NOT SEEING ANYTHING IN THIS PATTERN THAT WOULD LEND ITSELF TO ANY SIGNIFICANT PRECIPITATION...AND WOULD BE VERY UNLIKELY TO BELIEVE IT ANYWAY GIVEN THE DRYNESS OF THE PATTERN OVER THE LAST SEVERAL WEEKS. SO WILL RIDE ALONG WITH PERSISTENCE AND KEEP THINGS DRY. APPEARS FIRE WEATHER WILL REMAIN OF PRIMARY CONCERN THRU THIS EXTENDED PERIOD. && .AVIATION... VFR. EAST WIND INCREASING TO 15 TO 20 KT AT KGGW TONIGHT WITH LIGHTER SPEEDS AT THE OTHER SITES. A COLD FRONT MOVING THROUGH THE AREA TUESDAY MORNING...FROM ABOUT 7 AM TO NOON...WILL ALLOW WINDS TO SWITCH AND INCREASE FROM THE NORTHWEST AT SPEEDS OF 15 TO 25 KTS BY THE AFTERNOON. -TFJ && .FIRE WEATHER... UPGRADED FIRE WEATHER WATCH TO RED FLAG WARNING DUE TO LOW HUMIDITIES AND STRONG GUSTY WINDS TUESDAY. EXPECT WINDS TO INCREASE AROUND MID-MORNING AND PERSIST THROUGH EARLY EVENING WITH BEST POTENTIAL FOR STRONG GUSTS DURING AFTERNOON. LAST MINUTE LOOK AT UPDATED MODEL OUTPUT SUGGEST AFTERNOON GUSTS MAY BE STRONGER THAN IN FORECAST...BUT WILL ALLOW LATER SHIFTS OPPORTUNITY TO DO MORE THOROUGH MODEL EVALUATION. MIXING OF MID LEVEL WINDS PLUS INHERENTLY DRY AIRMASS WILL ALLOW MINIMUM HUMIDITIES TO FALL INTO TEENS THROUGH AFTERNOON. && .CLIMATE... THERE HAVE BEEN 12 DAYS IN A ROW WITH A HIGH TEMPERATURE OF 90 OR ABOVE IN GLASGOW. THIS IS THE LONGEST STREAK SINCE 1958. THE ALL- TIME RECORD IS 20 CONSECUTIVE DAYS SET BACK IN 1936. SHOULD EASILY REACH 14 DAYS IN A ROW OVER 90...BUT NOW APPEARS A GOOD CHANCE THERE WILL BE ONE DAY THIS WEEK...WEDNESDAY...THAT WON'T QUITE REACH 90. SO FAR THIS MONTH THERE HAVE BEEN 3 DAYS WITH A HIGH TEMPERATURE ABOVE 100 DEGREES. THE AVERAGE TEMPERATURE SO FAR THIS MONTH OF 76.5 DEGREES IS 7.3 DEGREES ABOVE NORMAL. IT IS THE WARMEST START TO THE MONTH OF JULY SINCE 1947. && .GLASGOW WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM 9 AM TO 9 PM MDT TUESDAY FOR MTZ119-MTZ120- MTZ121-MTZ122. LAKE WIND ADVISORY FROM 9 AM TO 9 PM MDT TUESDAY FOR FORT PECK LAKE. && $$ WEATHER.GOV/GLASGOW mt AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE BINGHAMTON NY 1150 AM EDT MON JUL 17 2006 .AVIATION (17/12Z TO 18/12Z)... VFR CONDITIONS EXPECTED THROUGHOUT FORECAST PERIOD AS HI PRESSURE TAKES OVR FROM THE SFC THRU MID-TROPOSPHERE. HV CHC POPS FOR LATE TONIGHT AS POTENTIAL EXISTS FOR SOME CONVECTION B4 12Z TUE IN THE NRN AND WRN TAF SITES...KELM...KITH AND KSYR. && .SHORT TERM (TODAY - TUESDAY)... UPDATE TO REMOVE THE MORNING WORDING FOR FOG AND WIND. MADE ONLY SUBTLE CHANGES TO THE GRIDS TO ADJUST TO CURRENT CONDITIONS. THE GOING MAX TEMP STILL LOOKS GOOD AND WILL STAY THE COURSE WITH THE HEAT ADVISORY. RUC AND NAM SPIT SOME PRECIP OUT FOR CWA LATE TODAY. WITH HEAT AND HUMIDITY PLENTY OF INSTABILITY IF CAP CAN BE BROKEN. LACKING A TRIGGER AND A LITTLE MORE SHEAR. UL RIDGE WILL CONTINUE TO PUSH HOT PLAINS AIR INTO UPSTATE NY AND NORTHEAST PA THIS AFTERNOON. CONVECTION IS MOVING PRECARIOUSLY OVER THE TOP OF THIS RIDGE, AS AMPLE INSTABILITY EXISTS OVER WESTERN GREAT LAKES. WILL NEED TO CLOSELY MONITOR STRENGTH OF THE RIDGE, AS ANY FLATTENING WILL ALLOW CONVECTION TO SNEAK INTO FA. MAIN STORY TODAY IS AMOUNT OF HEAT. THE SOURCE REGION TO SOUTHWEST IS ACTUALLY FAIRLY DRY, AND THIS WILL BE THE SAVING GRACE TODAY. WHILE TEMPERATURES ARE LIKELY TO CLIMB TO BETWEEN 92 AND 96 DEGREES BY AFTERNOON, DEW POINTS WILL BE IN THE MID 60S WHICH IS NOT UNUSUAL AT ALL. THE COMBINATION WILL YIELD HEAT INDICES BETWEEN 97 AND 102, WHICH BARELY MEETS LOCAL ADVISORY CRITERIA. FOLLOWED A MIX OF FWC/MAV FOR POPULATING TD FIELDS, PER COORDINATION WITH ALY/PHI/OKX. COLD FRONT WILL APPROACH REGION OVERNIGHT AND SPREAD SHOWERS AND THUNDERSTORMS INTO NY AND PA TUESDAY. HAVE INCREASED POPS TO HIGH CHC AS CONVECTIVE POTENTIAL IS INCREASING. CAPES INCREASE TO 1500 J/KG BY AFTERNOON AS MOISTURE INCREASES AHEAD OF COLD FRONT. LOOKS LIKE THERE WILL BE SOME SEVERE POTENTIAL BY MIDDAY TUESDAY, BUT SHOULD HAVE A BETTER HANDLE ON THIS IN 24H. DJP && .LONG TERM (TUESDAY NIGHT - SATURDAY)... FOLLOWED HPC GUIDANCE. FAST NEARLY ZONAL FLOW. START OUT WITH SFC HIGH WED INTO EARLY THU. THU PM CONVECTION SHOULD DEVELOP AHEAD OF SFC COLD FRONT AND SHORT WAVES. FROPA FRI MORNING BUT AS USUAL THIS TIME OF YEAR QUESTION ON HOW FAR THE FRONT MAKES IT. A SFC LOW MOVES EAST FOR MORE SHOWERS SAT PM INTO SUN. && .BGM WATCHES/WARNINGS/ADVISORIES... .NY...HEAT ADVISORY ALL CNY UNTIL 8 PM THIS EVENING. .PA...HEAT ADVISORY ALL NEPA UNTIL 8 PM THIS EVENING. $$ ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ABERDEEN SD 913 AM CDT MON JUL 17 2006 .DISCUSSION...UPDATED FORECAST TO INCLUDE THICKER CLOUD COVER OVER THE WEST. AN AREA OF MID LEVEL FRONTOGENESIS APPEARS TO BE HELPING SOME HIGH BASED SHOWERS DEVELOP IN THIS AREA. THE LOWEST SCAN OF THE KBIS RADAR INDICATES THAT NOT MUCH OF THIS ACTIVITY IS LIKELY REACHING THE GROUND. HAVE INSERTED SPRINKLES IN THE NORTHWEST. THIS AREA OF FORCING SAGS SOUTH SOMEWHAT TODAY...INCREASING CLOUD COVER IN THE SOUTHWEST. THE MODELS ARE REALLY DRY IN THE LOWER LEVELS TODAY...AND DURING THE AFTERNOON IT LOOKS LIKE THE HIGHER CLOUDS WILL BE DECREASING AND SHIFTING FURTHER SOUTH. THE REST OF THE FORECAST APPEARED ON TRACK. && .PREV DISCUSSION... (ISSUED 330 AM CDT MON JUL 17 2006) SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT SFC COOL FRONT CONTINUING TO MAKE SLOW PROGRESS SE AND STILL ON TRACK TO BE THROUGH MOST OF THE CWA BY 12Z. FRONT IS MOVING A TAD SLOWER THAN RUC AND HI RES NAM INDICATE. LINGERING ISO/SCT CONVECTION ONGOING OUT AHEAD OF BOUNDARY ACROSS EXTREME NE SD AND WEST CENTRAL MN. EXPECT THIS ACTIVITY TO END BY 12Z AS SFC FRONT CONTINUES TO MOVE SE. WILL FINALLY SEE COOLER TEMPS TODAY RELATIVE TO THE PAST SEVERAL DAYS AS CAA GETS ESTABLISHED DURING THE DAY. SHOULD SEE HIGHS DROPPING BACK INTO THE 80S AND 90S FOR MOST LOCATIONS. NORTH WINDS WILL BE ON THE BREEZY SIDE THIS MORNING AND INTO THE EARLY AFTERNOON BEFORE SFC HIGH PRESSURE BEGINS TO BUILD IN FROM THE NW AND WINDS SLACKEN. HIGH SETTLES OVER THE EASTERN DAKOTAS AND MINNESOTA OVERNIGHT PROVIDING LIGHT WINDS AND MOSTLY CLEAR SKIES. DROPPED LOWS TONIGHT CLOSER TO 00Z GUIDANCE VALUES. AS THE HIGH MOVES EAST ON TUESDAY WAA QUICKLY RETURNS AND 850 MB TEMPS ONCE AGAIN APPROACH 30 C BY THE AFTERNOON ACROSS CENTRAL SD. SHOULD SEE HIGHS NEAR 100 AGAIN WITH 90S EXPECTED INTO THE EASTERN COUNTIES. SOUTH WINDS WILL INCREASE ON TUESDAY AS A SFC TROUGH DEVELOPS ACROSS THE WESTERN DAKOTAS AND EASTERN MT/WY. DID ADD ISO MENTION FOR STORMS TUESDAY AFTERNOON AS SFC TROUGH NEARS CENTRAL SD. LAPSE RATES STEEPEN AS WELL AS LIFTED INDICES. BEST CHANCE THOUGH APPEARS TO BE TUESDAY NIGHT ACROSS THE EAST AS LOW LEVEL JET STRENGTHENS AND MID LEVEL TROUGH APPROACHES THE AREA. HAVE UPPED POPS A TAD ACROSS THE EAST. FOR WEDNESDAY...SFC BOUNDARY GETS HUNG UP ACROSS THE FAR E/SE COUNTIES DURING THE DAY. HAVE LEFT FORECAST DRY FOR NOW WITH UNCERTAINTY IN JUST HOW FAST THE BOUNDARY WILL MOVE BUT IF MODELS CONTINUE TO KEEP THIS ACROSS THE FAR E/SE IN FUTURE RUNS...MAY HAVE TO ADD POPS FOR WEDNESDAY. REMOVED SLIGHT CHANCE POPS DURING THE 06Z TO 12Z THURSDAY TIME AS SFC BOUNDARY JUST SEEMS TOO FAR SOUTH TO HAVE ANY MORE INFLUENCE ON THE AREA. TEMPERATURES WERE CHANGED LITTLE THROUGHOUT THE PERIOD AND SHOULD STILL REMAIN ABOVE NORMAL...ALTHOUGH NOT AS HOT AS THE PAST SEVERAL DAYS. LITTLE RELIEF IN SIGHT FOR CENTRAL/NORTH CENTRAL SD DROUGHT CONDITIONS AS ANY SHOT FOR PRECIP SEEMS TO BE LATE TUESDAY AFTERNOON. ANY HEAVIER RAIN SHOULD REMAIN WELL EAST INTO THE EASTERN DAKOTAS AND WEST CENTRAL MN TUESDAY NIGHT WITH DEVELOPMENT OF LOW LEVEL JET. LONG TERM...THURSDAY THROUGH SUNDAY BIGGEST CHALLENGE FACING THE EXTENDED FORECAST IS PCPN CHCS...FOLLOWED BY RETURN TO NEAR NORMAL TEMPS. DOMINATE CENTRAL CONUS RIDGE TRANSITIONS TO THE WEST AT THE BEGINNING OF THE EXTENDED...LEAVING THE CONUS IN A WEST COAST RIDGE/EAST COAST TROF FLOW PATTERN. 5H HEIGHTS FALL SLIGHTLY OVER CWA...WITH 85H AND 7H TEMPS FALLING BACK TOWARD A MORE NORMAL READING FOR THIS TIME OF YEAR. TO START THE EXTENDED...GOOD CAA PATTERN IN PLACE AT 85H AND 7H WITH STALLED BOUNDARY SOMEWHERE ACROSS WRN NE/WRN SD. MODELS DIFFER ON EXACT PLACEMENT. THIS BOUNDARY BECOMES THE FOCUS FOR PCPN CHANCES ON FRIDAY AS IT BEGINS TO LIFT BACK TO THE NORTH WITH WAA PATTERN. CURRENTLY HAVE 12HR SLGT CHC POPS BEGINNING 12Z FRIDAY...AND CONFIDENCE NOT THAT HIGH. 00Z GFS HAS PAINTED QPF FURTHER SW...WITH 18Z DGEX AND 00Z CANADIAN REMAINING DRY. THERE ARE A FEW CANADIAN ENSEMBLE MEMBERS THAT DO AGREE WITH PCPN POTENTIAL DURING DAY FRIDAY. WITHOUT SOLID ARGUMENT TO REMOVING 20 POPS...HAVE LEFT THEM IN FOR FRIDAY. TEMPS LOOK SEASONABLE AND PLEASANT GIVEN THIS PAST WEEKEND. LOWERED TEMPS A BIT FOR THURSDAY NIGHT GIVEN STRENGTH OF CAA PATTERN. TT/DH && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ KNUTSVIG sd AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE FORT WORTH TX 1100 AM CDT MON JUL 17 2006 .UPDATE... NO MAJOR WHOLESALE CHANGES WITH THIS UPDATED. HAVE ADJUSTED TRENDS (GRIDS TRENDS) IN TEMPS...DP.. AND WINDS FOR TODAY HIS AFTERNOON AND TONIGHT. THERE IS SOME INSTABILITY FOR SHRA/ISOLD TSRA OVER THE EASTERN HALF THIS AFTERNOON AND EARLY EVENING. 12Z FWD SOUNDING SHOWS THE I-35 CORRIDOR SLIGHTLY DRIER IN THE 900-850 MB LAYER THAN YESTERDAY WHILE SHV SOUNDING SHOWS DRYING ABOVE 850MB BUT SLIGHTLY HIGHER DEWPOINTS SFC-850MB. AFTERNOON MIXING SHOULD TAKE SURFACE DEWPOINTS DOWN THIS AFTERNOON ALONG AND WEST OF I-35 BUT NOT AS MUCH TO THE EAST. THIS SHOULD PRODUCE AN INVERT V SOUNDING LOCALLY DURING THE AFTERNOON WHICH WILL ENHANCE DOWNBURST POTENTIAL (LOCAL STUDY INDICATES UP TO 85 MPH) FROM TSRA OVER THE EASTERN HALF. 75 && .UPDATE... 755 AM. AS NOTED IN THE AVIATION DISCUSSION BELOW...PRECIPITABLE WATER VALUES ARE INCREASING FROM THE EAST. ACCAS HAS BEEN NOTED TO ACROSS THE EASTERN PART OF THE FORECAST AREA...AND ISOLATED SHOWERS HAVE NOW STARTED TO DEVELOP. AN UPDATE HAS BEEN SENT TO INCREASE THE POPS ACROSS THE AREA ALONG AND EAST OF I-35 TO 20 PERCENT...AND THE ISOLATED WORDING HAS BEEN CHANGED TO SLIGHT CHANCE. HAVE ALSO ADJUSTED THE SKY COVER WORDING TO PARTLY CLOUDY FROM MOSTLY SUNNY A LITTLE FARTHER WEST. #58 && .CLIMATE... WE THOUGHT THAT WE MIGHT TIE THE ALL TIME RECORD HIGH MINIMUM OF 85 DEGREES AT DFW...WHICH WAS SET ON SEPTEMBER 1 1939. AS OF 7 AM CDT...THE LOW FOR TODAY HAD BEEN 85 DEGREES..HOWEVER...AT 708 AM...THE TEMPERATURE FELL TO 83 DEGREES. IT THE LOW HOLDS AT 83 DEGREES IT WILL TIE THE RECORD HIGH MINIMUM FOR JULY 17TH...PREVIOUSLY SET IN 1956. #58 && .AVIATION... 645 AM CDT MON JUL 17 2006 REMOTE SENSING OF PRECIPITABLE WATER INDICATES THAT A HEALTHY MOISTURE AXIS IS MOVING IN FROM THE EAST. MORNING SATELLITE ALSO SHOWS ALTOCUMULUS IS PRESENT OVER THE EASTERN ZONES WITH VERY ISOLATED SHOWERS ALREADY DEVELOPING. RUC/NAM/HI-RES WRF MODELS DEVELOP CONVECTION ALONG AND EAST OF I-35 THIS AFTERNOON. DESPITE THE SUBSIDENCE IN PLACE FROM HIGH PRESSURE ALOFT...VIGOROUS THERMALS FROM INTENSE SURFACE HEATING WILL ALLOW SOME PARCELS TO ATTAIN THEIR LFC. INVERTED V SOUNDING WITH HIGH BASED CONVECTION WILL CREATE A VERY FAVORABLE ENVIRONMENT FOR MICROBURSTS THIS AFTERNOON AND EVENING...AND ALL AIRCRAFT NEED TO AVOID FLYING NEAR ANY CB TODAY. FOR TAFS...WILL SHOW JUST A PROB30 FOR DFW/DAL/ACT THIS AFTERNOON AND EVENING...TO SHOW CB CLOUD GROUPS AND VRB20G30KT WINDS. ALL IN ALL...IT IS A VFR FORECAST WITH THE CAVEAT OF CONVECTIVELY INDUCED OUTFLOWS CREATING PROBLEMS WITH TRAFFIC FLOW IN THE TRACON. PREVAILING WINDS WILL BE LIGHT SW THIS MORNING...BECOMING SE THIS AFTERNOON AS THERMAL LOW DEEPENS TO THE NW. TR.92 && .DISCUSSION... THE HOT WEATHER WILL CONTINUE FOR MUCH OF THE COMING WEEK AS THE UPPER RIDGE DOMINATES THE WEATHER ACROSS THE REGION. THE BIGGEST QUESTION IS WHAT TO DO WITH THE HEAT ADVISORY. AREAS TO THE NORTH AND NORTHEAST ARE ALSO SEEING HEAT INDEX VALUES CLIMBING TO 105 DEGREES OR HIGHER...PARIS HIT 107 AND SULPHUR SPRINGS AND GREENVILLE HIT 106...AND SHERMAN HIT 105 DEGREES YESTERDAY. HOWEVER THE LOW TEMPERATURES ARE FALLING BELOW THAT PART OF THE CRITERIA AT SOME SITES. GIVEN THE SPACING BETWEEN SITES...AND THE DESIRE TO HAVE A UNIFORM ADVISORY WITH NEIGHBORING OFFICES...WILL EXPAND THE ADVISORY NORTH AND EAST...TO INCLUDE THAT PART OF NORTH TEXAS ALONG AND NORTH OF JACKSBORO...CLEBURNE AND CANTON. THE UPPER RIDGE IS FORECAST TO WEAKEN AS THE WEEKEND APPROACHES... AND WE SHOULD SEE TEMPERATURES COOL SLIGHTLY. RAIN CHANCE DON/T LOOK TOO GOOD FOR THE COMING WEEK. HAVE INCLUDED ISOLATED AFTERNOON/EVENING SHOWERS/THUNDERSTORMS FOR TODAY ACROSS THE EASTERN HALF OF THE FORECAST AREA. IF WE GET SOME STORMS TO FORM...THERE WILL BE THE POTENTIAL FOR DAMAGING DOWNBURST WINDS. OTHERWISE...IT LOOKS PRETTY DRY. WE MAY SEE A SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS OVER THE SOUTHEAST SATURDAY AND THE EAST ON SUNDAY AS THE RIDGE WEAKENS. #58 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 104 80 104 80 / 0 10 0 10 WACO, TX 103 78 102 77 / 0 10 10 10 PARIS, TX 103 77 103 75 / 10 10 0 10 DENTON, TX 106 78 105 77 / 0 10 0 10 MCKINNEY, TX 103 76 104 76 / 10 10 0 10 DALLAS, TX 103 83 103 82 / 10 10 0 10 TERRELL, TX 104 78 102 75 / 10 10 10 10 CORSICANA, TX 102 77 101 75 / 10 10 10 10 TEMPLE, TX 100 76 100 74 / 0 10 10 10 && .FWD WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY UNTIL 7 PM TUESDAY FOR TXZ091-TXZ092-TXZ093-TXZ094- TXZ095-TXZ101-TXZ102-TXZ103-TXZ104-TXZ105-TXZ106-TXZ107-TXZ117- TXZ118-TXZ119-TXZ120-TXZ121-TXZ122-TXZ123-TXZ133-TXZ134. && $$ 92/58 tx AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE FORT WORTH TX 715 AM CDT MON JUL 17 2006 .UPDATE... AS NOTED IN THE AVIATION DISCUSSION BELOW...PRECIPITABLE WATER VALUES ARE INCREASING FROM THE EAST. ACCAS HAS BEEN NOTED TO ACROSS THE EASTERN PART OF THE FORECAST AREA...AND ISOLATED SHOWERS HAVE NOW STARTED TO DEVELOP. AN UPDATE HAS BEEN SENT TO INCREASE THE POPS ACROSS THE AREA ALONG AND EAST OF I-35 TO 20 PERCENT...AND THE ISOLATED WORDING HAS BEEN CHANGED TO SLIGHT CHANCE. HAVE ALSO ADJUSTED THE SKY COVER WORDING TO PARTLY CLOUDY FROM MOSTLY SUNNY A LITTLE FARTHER WEST. #58 && .CLIMATE... WE THOUGHT THAT WE MIGHT TIE THE ALL TIME RECORD HIGH MINIMUM OF 85 DEGREES AT DFW...WHICH WAS SET ON SEPTEMBER 1 1939. AS OF 7 AM CDT...THE LOW FOR TODAY HAD BEEN 85 DEGREES..HOWEVER...AT 708 AM...THE TEMPERATURE FELL TO 83 DEGREES. IT THE LOW HOLDS AT 83 DEGREES IT WILL TIE THE RECORD HIGH MINIMUM FOR JULY 17TH...PREVIOUSLY SET IN 1956. #58 && .AVIATION... 645 AM CDT MON JUL 17 2006 REMOTE SENSING OF PRECIPITABLE WATER INDICATES THAT A HEALTHY MOISTURE AXIS IS MOVING IN FROM THE EAST. MORNING SATELLITE ALSO SHOWS ALTOCUMULUS IS PRESENT OVER THE EASTERN ZONES WITH VERY ISOLATED SHOWERS ALREADY DEVELOPING. RUC/NAM/HI-RES WRF MODELS DEVELOP CONVECTION ALONG AND EAST OF I-35 THIS AFTERNOON. DESPITE THE SUBSIDENCE IN PLACE FROM HIGH PRESSURE ALOFT...VIGOROUS THERMALS FROM INTENSE SURFACE HEATING WILL ALLOW SOME PARCELS TO ATTAIN THEIR LFC. INVERTED V SOUNDING WITH HIGH BASED CONVECTION WILL CREATE A VERY FAVORABLE ENVIRONMENT FOR MICROBURSTS THIS AFTERNOON AND EVENING...AND ALL AIRCRAFT NEED TO AVOID FLYING NEAR ANY CB TODAY. FOR TAFS...WILL SHOW JUST A PROB30 FOR DFW/DAL/ACT THIS AFTERNOON AND EVENING...TO SHOW CB CLOUD GROUPS AND VRB20G30KT WINDS. ALL IN ALL...IT IS A VFR FORECAST WITH THE CAVEAT OF CONVECTIVELY INDUCED OUTFLOWS CREATING PROBLEMS WITH TRAFFIC FLOW IN THE TRACON. PREVAILING WINDS WILL BE LIGHT SW THIS MORNING...BECOMING SE THIS AFTERNOON AS THERMAL LOW DEEPENS TO THE NW. TR.92 && .DISCUSSION... THE HOT WEATHER WILL CONTINUE FOR MUCH OF THE COMING WEEK AS THE UPPER RIDGE DOMINATES THE WEATHER ACROSS THE REGION. THE BIGGEST QUESTION IS WHAT TO DO WITH THE HEAT ADVISORY. AREAS TO THE NORTH AND NORTHEAST ARE ALSO SEEING HEAT INDEX VALUES CLIMBING TO 105 DEGREES OR HIGHER...PARIS HIT 107 AND SULPHUR SPRINGS AND GREENVILLE HIT 106...AND SHERMAN HIT 105 DEGREES YESTERDAY. HOWEVER THE LOW TEMPERATURES ARE FALLING BELOW THAT PART OF THE CRITERIA AT SOME SITES. GIVEN THE SPACING BETWEEN SITES...AND THE DESIRE TO HAVE A UNIFORM ADVISORY WITH NEIGHBORING OFFICES...WILL EXPAND THE ADVISORY NORTH AND EAST...TO INCLUDE THAT PART OF NORTH TEXAS ALONG AND NORTH OF JACKSBORO...CLEBURNE AND CANTON. THE UPPER RIDGE IS FORECAST TO WEAKEN AS THE WEEKEND APPROACHES... AND WE SHOULD SEE TEMPERATURES COOL SLIGHTLY. RAIN CHANCE DON/T LOOK TOO GOOD FOR THE COMING WEEK. HAVE INCLUDED ISOLATED AFTERNOON/EVENING SHOWERS/THUNDERSTORMS FOR TODAY ACROSS THE EASTERN HALF OF THE FORECAST AREA. IF WE GET SOME STORMS TO FORM...THERE WILL BE THE POTENTIAL FOR DAMAGING DOWNBURST WINDS. OTHERWISE...IT LOOKS PRETTY DRY. WE MAY SEE A SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS OVER THE SOUTHEAST SATURDAY AND THE EAST ON SUNDAY AS THE RIDGE WEAKENS. #58 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 104 80 104 80 / 0 10 0 10 WACO, TX 103 78 102 77 / 0 10 10 10 PARIS, TX 103 77 103 75 / 10 10 0 10 DENTON, TX 106 78 105 77 / 0 10 0 10 MCKINNEY, TX 103 76 104 76 / 10 10 0 10 DALLAS, TX 103 83 103 82 / 10 10 0 10 TERRELL, TX 104 78 102 75 / 10 10 10 10 CORSICANA, TX 102 77 101 75 / 10 10 10 10 TEMPLE, TX 100 76 100 74 / 0 10 10 10 && .FWD WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY UNTIL 7 PM TUESDAY FOR TXZ091-TXZ092-TXZ093-TXZ094- TXZ095-TXZ101-TXZ102-TXZ103-TXZ104-TXZ105-TXZ106-TXZ107-TXZ117- TXZ118-TXZ119-TXZ120-TXZ121-TXZ122-TXZ123-TXZ133-TXZ134. && $$ 92/58 tx AREA FORECAST DISCUSSION...UPDATED FOR AVIATION NATIONAL WEATHER SERVICE FORT WORTH TX 645 AM CDT MON JUL 17 2006 .AVIATION... REMOTE SENSING OF PRECIPITABLE WATER INDICATES THAT A HEALTHY MOISTURE AXIS IS MOVING IN FROM THE EAST. MORNING SATELLITE ALSO SHOWS ALTOCUMULUS IS PRESENT OVER THE EASTERN ZONES WITH VERY ISOLATED SHOWERS ALREADY DEVELOPING. RUC/NAM/HI-RES WRF MODELS DEVELOP CONVECTION ALONG AND EAST OF I-35 THIS AFTERNOON. DESPITE THE SUBSIDENCE IN PLACE FROM HIGH PRESSURE ALOFT...VIGOROUS THERMALS FROM INTENSE SURFACE HEATING WILL ALLOW SOME PARCELS TO ATTAIN THEIR LFC. INVERTED V SOUNDING WITH HIGH BASED CONVECTION WILL CREATE A VERY FAVORABLE ENVIRONMENT FOR MICROBURSTS THIS AFTERNOON AND EVENING...AND ALL AIRCRAFT NEED TO AVOID FLYING NEAR ANY CB TODAY. FOR TAFS...WILL SHOW JUST A PROB30 FOR DFW/DAL/ACT THIS AFTERNOON AND EVENING...TO SHOW CB CLOUD GROUPS AND VRB20G30KT WINDS. ALL IN ALL...IT IS A VFR FORECAST WITH THE CAVEAT OF CONVECTIVELY INDUCED OUTFLOWS CREATING PROBLEMS WITH TRAFFIC FLOW IN THE TRACON. PREVAILING WINDS WILL BE LIGHT SW THIS MORNING...BECOMING SE THIS AFTERNOON AS THERMAL LOW DEEPENS TO THE NW. TR.92 && .DISCUSSION... THE HOT WEATHER WILL CONTINUE FOR MUCH OF THE COMING WEEK AS THE UPPER RIDGE DOMINATES THE WEATHER ACROSS THE REGION. THE BIGGEST QUESTION IS WHAT TO DO WITH THE HEAT ADVISORY. AREAS TO THE NORTH AND NORTHEAST ARE ALSO SEEING HEAT INDEX VALUES CLIMBING TO 105 DEGREES OR HIGHER...PARIS HIT 107 AND SULPHUR SPRINGS AND GREENVILLE HIT 106...AND SHERMAN HIT 105 DEGREES YESTERDAY. HOWEVER THE LOW TEMPERATURES ARE FALLING BELOW THAT PART OF THE CRITERIA AT SOME SITES. GIVEN THE SPACING BETWEEN SITES...AND THE DESIRE TO HAVE A UNIFORM ADVISORY WITH NEIGHBORING OFFICES...WILL EXPAND THE ADVISORY NORTH AND EAST...TO INCLUDE THAT PART OF NORTH TEXAS ALONG AND NORTH OF JACKSBORO...CLEBURNE AND CANTON. THE UPPER RIDGE IS FORECAST TO WEAKEN AS THE WEEKEND APPROACHES... AND WE SHOULD SEE TEMPERATURES COOL SLIGHTLY. RAIN CHANCE DON/T LOOK TOO GOOD FOR THE COMING WEEK. HAVE INCLUDED ISOLATED AFTERNOON/EVENING SHOWERS/THUNDERSTORMS FOR TODAY ACROSS THE EASTERN HALF OF THE FORECAST AREA. IF WE GET SOME STORMS TO FORM...THERE WILL BE THE POTENTIAL FOR DAMAGING DOWNBURST WINDS. OTHERWISE...IT LOOKS PRETTY DRY. WE MAY SEE A SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS OVER THE SOUTHEAST SATURDAY AND THE EAST ON SUNDAY AS THE RIDGE WEAKENS. #58 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 104 80 104 80 / 0 10 0 10 WACO, TX 103 78 102 77 / 0 10 10 10 PARIS, TX 103 77 103 75 / 10 10 0 10 DENTON, TX 106 78 105 77 / 0 10 0 10 MCKINNEY, TX 103 76 104 76 / 10 10 0 10 DALLAS, TX 103 83 103 82 / 10 10 0 10 TERRELL, TX 104 78 102 75 / 10 10 10 10 CORSICANA, TX 102 77 101 75 / 10 10 10 10 TEMPLE, TX 100 76 100 74 / 0 10 10 10 && .FWD WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY UNTIL 7 PM TUESDAY FOR TXZ091-TXZ092-TXZ093-TXZ094- TXZ095-TXZ101-TXZ102-TXZ103-TXZ104-TXZ105-TXZ106-TXZ107-TXZ117- TXZ118-TXZ119-TXZ120-TXZ121-TXZ122-TXZ123-TXZ133-TXZ134. && $$ 92/58 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BURLINGTON VT 1029 PM EDT MON JUL 17 2006 .SHORT TERM /OVERNIGHT/... WILL UPDATE THE ZONE FORECASTS TO REMOVE REFERENCES TO THIS EVENING AND ALSO DROP MENTION OF AIR STAGNATION ADVISORY IN NORTHERN NEW YORK WHICH EXPIRED AT 10 PM EDT. COMPOSITE RADAR LOOP SHOWING STRONG THUNDERSTORMS OVER CANADA MOVING EAST AT THIS TIME. AFTER LOOKING AT 18Z GFS MODEL AND CURRENT TRENDS ON RADAR WILL DELAY MENTION OF SHOWERS AND THUNDERSTORMS ACROSS MOST ZONES UNTIL AROUND DAYBREAK... EXCEPT WILL GO WITH LIKELY POPS AFTER MIDNIGHT IN THE SAINT LAWRENCE VALLEY IN NORTHERN NEW YORK. OVERNIGHT MIN TEMPERATURES AND WINDS LOOK REASONABLE...SO NO CHANGES MADE. OTHERWISE...NO CHANGES TO THE REMAINDER OF THE FORECAST. && .PREV DISCUSSION... /ISSUED 400 PM EDT MON JUL 17 2006/ SHORT TERM /TONIGHT THROUGH THURSDAY/... MAIN FCST CHALLENGE OVER COURSE OF SHORT TERM WILL BE POTENTIAL FOR STRONG TO POSSBLY SVR CONVECTION LATER TONIGHT INTO FIRST HALF OF TUESDAY. AFTERWARDS...A GENERAL TREND TOWARDS LESS HUMID AND MORE SEASONABLE TEMPS TUE NT THROUGH EARLY THURSDAY BEFORE NEXT FRONT ARRIVES. LATEST SYNOPTIC/SFC MAP INDICATING PLENTY OF HEAT/HUMIDITY ACROSS NORTH COUNTRY THIS AFTERNOON AS NOSE OF 20C 850 HPA AIR SINKS SLOWLY SOUTHWARD ACROSS AREA. TEMPS RANGING GENERALLY BTWN 86 AND 92 DEGREES AREA WIDE...WITH HEAT INDICES 95 TO 100. LATEST RUC SOUNDINGS SHOWING PLENTY OF CAPE ACROSS REGION...BUT MUCH OF AREA HAS REMAINED CAPPED BY AFOREMENTIONED WARM LYR ALOFT. A FEW ISOLD SHRAS HAVE FORMED ACROSS ERN VT WITHIN PAST HOUR AS WEAK TROUGHING AT 700 HPA SLIDES EASTWARD FROM ERN VT NE INTO ME. LITTLE IN THE WAY OF A SOURCE OF LIFT/MOISTURE CONVERGENCE OTHER THAN LOCAL OROGRAPHICALLY FORCED UPDRAFTS...AND EXPECT CURRENT ACTIVITY TO DIE BY SUNSET OR SHORTLY THEREAFTER. PRIMARY CONCERN LIES WITH POTENTIAL FOR STRONG TO PERHAPS SEVERE CONVECTION LATER TONIGHT INTO TUESDAY AS SFC COLD FRONT ACROSS SC CANADA PUSHES SE INTO MUGGY/UNSTABLE AIRMASS ACROSS REGION. INCREASING 0-6KM SHEAR VALUES TO 35-45 KNOTS PUSH INTO SLV/WRN DACKS LATER TONIGHT ALONG WITH MID LVL HEIGHT FALLS AND WELL DEFINED EML BTWN 700-500 HPA. THIS COMBINED WITH FAVORABLE RER UPPER JET DYNAMICS...AND APPROACHING BNDRY ARGUE FOR HIGH CHC TO LIKELY POPS LATER TONIGHT FROM KPLB NORTH AND WEST. UNIDIRECTIONAL NATURE OF WIND FIELD WOULD ARGUE FOR A MORE LINEAR NATURE TO CONVECTION...IF IT INDEED DEVELOPS...WITH BOW SEGMENTS/SQUALL LINE NOT OUT OF THE QUESTION WITH MUGGY/UNSTABLE AIRMASS IN PLACE. FURTHER SOUTH AND EAST...CONVECTION SHOULD NOT ARRIVE UNTIL SUNRISE OR THEREAFTER AND HAVE TAPERED POPS NW TO SE ACCORDINGLY. NONETHELESS...A MUGGY UNCOMFORTABLE NIGHT AREA WIDE...WITH MINS GENERALLY 68 TO 75. BY TUESDAY...AFOREMENTIONED CONVECTION SHOULD BE ONGOING ACROSS THE NORTH...WITH PARTLY CLOUDY CONDS SOUTH DURING THE MORNING HOURS. AGAIN...THREAT OF STRONG TO POSSBLY SVT STORMS INDEED POSSBL AS ENTIRE AREA UNDER SPC SLIGHT RISK. WILL HIGHLIGHT HIGHEST CHC OF PCPN DURING MORNING HOURS NORTH...THROUGH EARLY AFTERNOON CENTRAL...AND MID TO LATE AFTERNOON SOUTH TOMORROW. AFTERWARDS...IDEAL SENSIBLE CONDS TO RETURN FOR TUE NT INTO EARLY THU AS GREAT LAKES HIGH PRESSURE BUILDS EASTWARD ACROSS REGION. TEMPS TO EASE BACK TO SEASONABLE LVLS...WITH LOWER HUMIDITY LVLS AND LIGHT WIND REGIME. DUE TO DRIER NATURE OF AIR...WILL OFFER SOMEWHAT WIDER DIURNAL RANGES BTWN MAX/MIN VALUES. LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... SERIES OF COLD FRONTS ASSOCIATED WITH SHORTWAVE TROUGHS MOVING ACROSS THE NORTHEAST UNITED STATES THROUGH THE PERIOD WILL BE THE FOCUS FOR SHOWERS AND THUNDERSTORMS. THE FIRST COLD FRONT MOVES THROUGH LATE THURSDAY NIGHT INTO FRIDAY FOR A CHANCE OF CONVECTION WITH PRECIPITATION ENDING DURING THE AFTERNOON HOURS. HIGH PRESSURE BUILDS IN FRIDAY NIGHT INTO SATURDAY FROM THE NORTHWEST WHICH WILL BRING DRIER AIR BACK INTO THE REGION. LOOKING AT SEASONAL TEMPERATURES ONCE AGAIN ON SATURDAY AND SUNDAY AS WELL BEFORE NEXT SHORTWAVE TROUGH COLD FRONT MOVES IN SUNDAY NIGHT AND MONDAY. ONCE AGAIN IT LOOKS LIKE THE CHANCE OF STORMS WILL BEGIN SUNDAY NIGHT AND END DURING THE AFTERNOON HOURS ON MONDAY. TEMPERATURES ON MONDAY WILL ONCE AGAIN BE SEASONAL AS FLOW ALOFT WILL BE TRANSITIONING TO THE NORTHWEST. AVIATION... VFR CONDITIONS ARE EXPECTED THIS AFTERNOON AND MUCH OF THE NIGHT ACROSS THE AREA. A COLD FRONT WILL BEGIN TO IMPACT THE REGION BETWEEN 10Z AND 16Z AND WITH THIS FRONT WILL COME THE LIKELIHOOD OF THUNDERSTORMS. EXPECT THE FRONT TO REACH KMSS BETWEEN 10Z AND 12Z AND MOVE EAST OF KMPV BY 16Z. WINDS WILL SHIFT FROM THE SOUTHWEST TO THE WEST AND NORTHWEST WITH THE PASSAGE OF THE FRONT. OF GREATEST CONCERN WILL BE THE THUNDERSTORMS...WHICH COULD BE STRONG TO SEVERE. MAIN THREAT WITH THESE STORMS WILL BE STRONG WINDS AND HAVE INDICATED WIND GUSTS TO 40 KNOTS WITH ANY THUNDERSTORMS ALONG WITH IFR TO LIFR CONDITIONS AS THE THUNDERSTORM PASSES. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SHORT TERM...WGH vt AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BURLINGTON VT 400 PM EDT MON JUL 17 2006 .SHORT TERM /TONIGHT THROUGH THURSDAY/... MAIN FCST CHALLENGE OVER COURSE OF SHORT TERM WILL BE POTENTIAL FOR STRONG TO POSSBLY SVR CONVECTION LATER TONIGHT INTO FIRST HALF OF TUESDAY. AFTERWARDS...A GENERAL TREND TOWARDS LESS HUMID AND MORE SEASONABLE TEMPS TUE NT THROUGH EARLY THURSDAY BEFORE NEXT FRONT ARRIVES. LATEST SYNOPTIC/SFC MAP INDICATING PLENTY OF HEAT/HUMIDITY ACROSS NORTH COUNTRY THIS AFTERNOON AS NOSE OF 20C 850 HPA AIR SINKS SLOWLY SOUTHWARD ACROSS AREA. TEMPS RANGING GENERALLY BTWN 86 AND 92 DEGREES AREA WIDE...WITH HEAT INDICES 95 TO 100. LATEST RUC SOUNDINGS SHOWING PLENTY OF CAPE ACROSS REGION...BUT MUCH OF AREA HAS REMAINED CAPPED BY AFOREMENTIONED WARM LYR ALOFT. A FEW ISOLD SHRAS HAVE FORMED ACROSS ERN VT WITHIN PAST HOUR AS WEAK TROUGHING AT 700 HPA SLIDES EASTWARD FROM ERN VT NE INTO ME. LITTLE IN THE WAY OF A SOURCE OF LIFT/MOISTURE CONVERGENCE OTHER THAN LOCAL OROGRAPHICALLY FORCED UPDRAFTS...AND EXPECT CURRENT ACTIVITY TO DIE BY SUNSET OR SHORTLY THEREAFTER. PRIMARY CONCERN LIES WITH POTENTIAL FOR STRONG TO PERHAPS SEVERE CONVECTION LATER TONIGHT INTO TUESDAY AS SFC COLD FRONT ACROSS SC CANADA PUSHES SE INTO MUGGY/UNSTABLE AIRMASS ACROSS REGION. INCREASING 0-6KM SHEAR VALUES TO 35-45 KNOTS PUSH INTO SLV/WRN DACKS LATER TONIGHT ALONG WITH MID LVL HEIGHT FALLS AND WELL DEFINED EML BTWN 700-500 HPA. THIS COMBINED WITH FAVORABLE RER UPPER JET DYNAMICS...AND APPROACHING BNDRY ARGUE FOR HIGH CHC TO LIKELY POPS LATER TONIGHT FROM KPLB NORTH AND WEST. UNIDIRECTIONAL NATURE OF WIND FIELD WOULD ARGUE FOR A MORE LINEAR NATURE TO CONVECTION...IF IT INDEED DEVELOPS...WITH BOW SEGMENTS/SQUALL LINE NOT OUT OF THE QUESTION WITH MUGGY/UNSTABLE AIRMASS IN PLACE. FURTHER SOUTH AND EAST...CONVECTION SHOULD NOT ARRIVE UNTIL SUNRISE OR THEREAFTER AND HAVE TAPERED POPS NW TO SE ACCORDINGLY. NONETHELESS...A MUGGY UNCOMFORTABLE NIGHT AREA WIDE...WITH MINS GENERALLY 68 TO 75. BY TUESDAY...AFOREMENTIONED CONVECTION SHOULD BE ONGOING ACROSS THE NORTH...WITH PARTLY CLOUDY CONDS SOUTH DURING THE MORNING HOURS. AGAIN...THREAT OF STRONG TO POSSBLY SVT STORMS INDEED POSSBL AS ENTIRE AREA UNDER SPC SLIGHT RISK. WILL HIGHLIGHT HIGHEST CHC OF PCPN DURING MORNING HOURS NORTH...THROUGH EARLY AFTERNOON CENTRAL...AND MID TO LATE AFTERNOON SOUTH TOMORROW. AFTERWARDS...IDEAL SENSIBLE CONDS TO RETURN FOR TUE NT INTO EARLY THU AS GREAT LAKES HIGH PRESSURE BUILDS EASTWARD ACROSS REGION. TEMPS TO EASE BACK TO SEASONABLE LVLS...WITH LOWER HUMIDITY LVLS AND LIGHT WIND REGIME. DUE TO DRIER NATURE OF AIR...WILL OFFER SOMEWHAT WIDER DIURNAL RANGES BTWN MAX/MIN VALUES. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... SERIES OF COLD FRONTS ASSOCIATED WITH SHORTWAVE TROUGHS MOVING ACROSS THE NORTHEAST UNITED STATES THROUGH THE PERIOD WILL BE THE FOCUS FOR SHOWERS AND THUNDERSTORMS. THE FIRST COLD FRONT MOVES THROUGH LATE THURSDAY NIGHT INTO FRIDAY FOR A CHANCE OF CONVECTION WITH PRECIPITATION ENDING DURING THE AFTERNOON HOURS. HIGH PRESSURE BUILDS IN FRIDAY NIGHT INTO SATURDAY FROM THE NORTHWEST WHICH WILL BRING DRIER AIR BACK INTO THE REGION. LOOKING AT SEASONAL TEMPERATURES ONCE AGAIN ON SATURDAY AND SUNDAY AS WELL BEFORE NEXT SHORTWAVE TROUGH COLD FRONT MOVES IN SUNDAY NIGHT AND MONDAY. ONCE AGAIN IT LOOKS LIKE THE CHANCE OF STORMS WILL BEGIN SUNDAY NIGHT AND END DURING THE AFTERNOON HOURS ON MONDAY. TEMPERATURES ON MONDAY WILL ONCE AGAIN BE SEASONAL AS FLOW ALOFT WILL BE TRANSITIONING TO THE NORTHWEST. && .AVIATION... VFR CONDITIONS ARE EXPECTED THIS AFTERNOON AND MUCH OF THE NIGHT ACROSS THE AREA. A COLD FRONT WILL BEGIN TO IMPACT THE REGION BETWEEN 10Z AND 16Z AND WITH THIS FRONT WILL COME THE LIKELIHOOD OF THUNDERSTORMS. EXPECT THE FRONT TO REACH KMSS BETWEEN 10Z AND 12Z AND MOVE EAST OF KMPV BY 16Z. WINDS WILL SHIFT FROM THE SOUTHWEST TO THE WEST AND NORTHWEST WITH THE PASSAGE OF THE FRONT. OF GREATEST CONCERN WILL BE THE THUNDERSTORMS...WHICH COULD BE STRONG TO SEVERE. MAIN THREAT WITH THESE STORMS WILL BE STRONG WINDS AND HAVE INDICATED WIND GUSTS TO 40 KNOTS WITH ANY THUNDERSTORMS ALONG WITH IFR TO LIFR CONDITIONS AS THE THUNDERSTORM PASSES. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...AIR STAGNATION ADVISORY FOR NYZ026>031-034-035-087 UNTIL 10 PM MONDAY. && $$ SHORT TERM...JMG LONG TERM...EVENSON AVIATION...EVENSON vt AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LA CROSSE WI 341 PM CDT MON JUL 17 2006 .SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT AT 3 PM...A COLD FRONT EXTENDED FROM GREEN BAY TO JUST NORTH OF MASON CITY IOWA. SCATTERED SHOWERS AND THUNDERSTORMS ARE DEVELOPING ALONG AND AHEAD OF THIS FRONT. SURFACE BASED CONVECTIVE INHIBITIONS ARE STILL RUNNING 50-100 J/KG ACROSS NORTHEAST IOWA. AS A RESULT...THE SHOWERS AND THUNDERSTORMS IN THIS AREA ARE ELEVATED. MEANWHILE THE ATMOSPHERE ACROSS WEST CENTRAL AND CENTRAL WISCONSIN HAS BECOME MORE FAVORABLE FOR SURFACE BASED THUNDERSTORMS TO DEVELOP. THE RUC SHOWS THAT THE CONVECTIVE INHIBITIONS WILL CONTINUE TO WEAKEN ACROSS NORTHEAST IOWA THIS AFTERNOON AS A RESULT THIS AREA WILL ALSO HAVE TO BE WATCHED FOR SURFACE BASED THUNDERSTORMS. WITH 100 MB MEAN LAYER CAPES RUNNING 4000-5000 J/KG...THERE WILL BE PLENTY OF INSTABILITY FOR EXPLOSIVE THUNDERSTORM DEVELOPMENT. WITH 0-6 KM EFFECTIVE SHEAR AROUND 30-35 KNOTS...THESE THUNDERSTORMS WILL HAVE THE POTENTIAL TO BECOME SUPERCELLULAR. WITH DOWNDRAFT CAPE IN THE 1000-1500 J/KG... THERE WILL BE THE POTENTIAL OF WET MICROBURSTS LATE THIS AFTERNOON AND EVENING. ON TUESDAY NIGHT...THE NAM CONTINUES TO DEVELOP A MESOSCALE CONVECTIVE COMPLEX ACROSS WESTERN MINNESOTA AND THE EASTERN DAKOTAS. THIS SYSTEM MOVES EAST ACROSS THE FORECAST AREA ON WEDNESDAY. MEANWHILE THE GFS SHOWS TWO MESOSCALE CONVECTIVE COMPLEXES DEVELOPING. THE FIRST SYSTEM DEVELOPS ACROSS NORTHWEST IOWA AND THE SECOND SYSTEM DEVELOP ACROSS WEST CENTRAL AND NORTHWEST MINNESOTA. THE GFS SEEMS TO BE RATHER CONSISTENT THAT THE SOUTHERN SYSTEM WILL MOVE SOUTHEAST ACROSS IOWA ON WEDNESDAY. THE NORTHERN SYSTEM IS RELATIVELY NEW AND ACTUALLY HAS BEEN TRENDING NORTHWARD WITH EACH SUCCESSIVE MODEL RUN. THE MAIN QUESTION IS HOW FAST THE WARM FRONT WILL NORTHWARD ON THE BACK SIDE OF THE CANADIAN HIGH. IN ADDITION...THE SPEED OF THE SURFACE COLD FRONT THROUGH THE REGION. THE NAM IS ABOUT 9 HOURS FASTER THAN THE GFS. IF THE NAM VERIFIES...MUCH OF THE AREA WILL SEE RAIN. MEANWHILE THE GFS WOULD GENERATE PRECIPITATION ONLY ACROSS NORTH CENTRAL WISCONSIN. AS A RESULT...I AM SOMEWHAT UNCERTAIN OF HIGH TO GO WITH THE PRECIPITATION CHANCES. DUE TO THIS UNCERTAINTY... I WENT WITH HIGH CHANCES FOR NOW. HOPEFULLY LATER MODELS WILL MAKE THIS PICTURE MUCH CLEARER. .LONG TERM...THURSDAY THROUGH MONDAY THE MEDIUM RANGE MODELS ARE CONTINUING TO SHOW A PATTERN SHIFT DURING THIS TIME PERIOD. THE UPPER LEVEL RIDGE WILL RETROGRADE TO THE WEST. THIS IN TURN WILL ALLOW A TROUGH TO DEVELOP ACROSS THE UPPER MISSISSIPPI VALLEY AND GREAT LAKES. THIS PLACES OUR AREA IN A NORTHWEST FLOW REGIME. AS ALWAYS THE CASE...IT IS HARD TO TIME SYSTEMS IN THIS PATTERN. THE MODELS APPEAR TO BE IN DECENT AGREEMENT THAT A COLD FRONT WILL MOVE THROUGH THE REGION ON SATURDAY. AS A RESULT...I KEPT A CHANCE OF SHOWERS AND THUNDERSTORMS IN THE FORECAST. THE GFS HINTS THAT THERE WILL BE OTHER CHANCES OF PRECIPITATION DURING THIS TIME PERIOD...BUT IT REMAINS RATHER INCONSISTENT AS A RESULT I WENT DRY FOR THE TIME BEING. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ BOYNE wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CLEVELAND OHIO 405 AM EDT TUE JUL 18 2006 .SHORT TERM(TODAY THROUGH WEDNESDAY NIGHT)... CONVECTION IS SHOWING SOME SIGNS OF WEAKENING AS IT MOVES THROUGH THE FORECAST AREA DURING THE EARLY MORNING HOURS. THE COLD FRONT SHOULD BE ACROSS THE EXTREME NORTH BY 14Z AND THEN JUST SOUTH OF THE FORECAST AREA BY 18Z. THE PROBLEM IS THE WRF/NAM AND IS TRYING TO HINT AT AN INVERTED TROF WITH SOME MOISTURE HANGING BACK OVER THE NORTHWEST PORTION OF THE FORECAST. ON THE EDGE WHETHER THIS IS CORRECT THE HIGH PRESSURE TO THE NORTH SEEMS LIKE IT SHOULD BE DOMINATE. THE 06Z RUC IS HINTING AT SOME MOISTURE HANGING BACK IN THE NORTH AT 18Z BUT THE FRONT IS JUST SOUTH OF THE AREA. WILL TRY TO PLAY THRU EARLY AFTERNOON EXTREME NORTH AND THEN NO TIMING ELSEWHERE. THE AIRMASS IN THE SOUTHERN PORTION OF THE CWA IS VERY UNSTABLE BY 16Z BUT THE BOUNDARY MAY BE RIGHT ON THEM OR JUST SOUTH. WITH TIMING QUESTIONS WILL NOT MENTION SEVERE IN THE ZONES/GRIDS BUT JUST ON THE OUTLOOK. MAXIMUM TEMPERATURES TOUGH FOR TODAY...GOING WITH GUIDANCE. TONIGHT IT SHOULD DRY OUT RAPIDILY BECOMING MOSTLY CLEAR. DRY WEATHER LOOKS GOOD WEDNESDAY AND WEDNESDAY NIGHT. GUIDANCE TEMPERATURES OK. && .LONG TERM (THU THRU MON)... NO REAL CHANGES TO THE EXTENDED. SOME CONCERNS ABOUT SUNDAY USING THE 00Z GFS. THE ECMWF IS TRYING TO SAY DRY WITH HIGH PRESSURE IN THE AREA. ATTM NOT BEING REAL CONFIDENT WILL JUST GO A 20 POP. DID INCREASE THE POP TO 50% THURSDAY NIGHT AS THAT LOOKS REASONABLE BASED ON THE CONSISTENT FRONTAL TIMING AND MOISTURE. PREVIOUS EXTENDED DISCUSSION... NOT MUCH HAS CHANGED AS MODELS CONTINUE TO SHOW LITTLE RUN TO RUN CONTINUITY. AS A RESULT CONFIDENCE REMAINS LOW WITH SPECIFIC DETAILS. CONSENSUS IS THAT GENERAL TROFINESS WILL CONT ACRS ERN CONUS WITH A SERIES OF FRONTAL SYSTEMS EXPECTED TO AFFECT FORECAST AREA. FIRST OF THESE WILL AFFECT AREA THU WITH WARM FRONTAL PASSAGE DURING DAY FOLLOWED BY A COLD FRONT THU NIGHT INTO FRI. THERE COULD ACTUALLY BE A DECENT AMOUNT OF RAIN ON THU AS MCS FROM THE WRN LAKES MOVES E ACROSS NRN OH AND INTERACTS WITH WARM FRONT. HIGH PRES WILL BRIEFLY BUILD IN SAT AND SUN BUT ANOTHER COLD FRONT WILL DIVE S ACROSS AREA MON. UNLIKE...THU/FRI SYSTEM...THIS ONE WILL LIKELY BE RELATIVELY DRY. HUMID CONDITIONS WILL CONT FOR MOST OF THE PERIOD. TEMPS WILL AVERAGE NEAR NORMAL ON SAT AND SUN BUT OTHERWISE WILL BE ABOVE NORMAL. && .AVIATION(06Z-06Z)... BAND OF TSRA WITH CDFNT IN LWR MI CONT TO WKN AS IT MOVD INTO LERI SO NOT SURE IF ANYTHING CAN HOLD TOGETHER LONG ENUF TO REACH ANY TAF SITES SO WL ONLY FCST ANY TSRA THAT LOOKS IMMINENT AT TAF TIME. BEST THREAT WUD OBVIOUSLY APPEAR TO BE FOR TOL AND FDY NEXT FEW HRS. BAND OF MSTR WITH CDFNT WL CONT TO SAG S INTO THE AREA TDA. OUTSIDE OF ANY TSRA...CIGS AND VSBY'S SHUD RMN VFR. && .CLE WATCHES/WARNINGS/ADVISORIES... .OH...NONE. .PA...NONE. && $$ SHORT TERM...KIELTYKA LONG TERM...KUBINA/KIELTYKA AVIATION...ADAMS oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 1000 AM EDT TUE JUL 18 2006 .REST OF TODAY... 12Z KTLH SOUNDING STILL SHOWING A FAIRLY MOIST PROFILE...AT LEAST THROUGH AROUND 500 MB. PW VALUE IS STILL AT 2.04" (123% OF NORMAL). MODIFYING THIS SOUNDING FOR AN AFTERNOON SURFACE PROFILE OF 94/68 WOULD GIVE JUST OVER 2000 J/KG OF CAPE WITH AN LI OF -5.1C. IMPRESSIVE ENOUGH FOR SCATTERED CONVECTION. HOWEVER...THE KTLH SOUNDING WAS DONE RIGHT ON THE EDGE OF A SOUTHWARD PROGRESSING TONGUE OF MUCH DRIER MID/UPPER LEVEL AIR. AS WAS MENTIONED ABOVE...EVEN THIS SOUNDING WAS STARTING TO SHOW THE DRY AIR INTRUSION ABOVE 500MB...AND AS THE DAY PROGRESSES WE SHOULD SEE THIS DRIER AIR BECOME MORE PREVALENT THROUGH A GREATER DEPTH OF THE COLUMN. MODEL SOUNDING ARE SHOWING THIS AS WELL...WITH THE DRIER AIR EXTENDING DOWN TO AROUND 700 MB BY THE MID AFTERNOON HOURS. USING THE SAME AFTERNOON CONDITIONS OF 94/68 GIVES ONLY 1300 J/KG WITH AN LI OF -3C. THIS CAPE VALUE IS CERTAINLY BELOW CLIMO FOR MID/LATE JULY AND HENCE GOING FORECAST OF BELOW CLIMO POPS IS STILL ON TRACK FOR THE AFTERNOON/EVENING HOURS. WITH THE NORTH TO SOUTH SCOURING OUT OF THE AVAILABLE MOISTURE...CHANCES FOR SEEING SCATTERED CONVECTION WILL CERTAINLY BE BETTER THE FURTHER SOUTH ONE GOES INTO THE FORECAST AREA...AND WILL BE GENERALLY ASSOCIATED WITH LOCAL CONVERGENCE ALONG THE AFTERNOON SEA-BREEZE AND ANY RESIDUAL BOUNDARIES LEFT BEHIND FROM YESTERDAY'S ACTIVITY. TEMPERATURE FORECASTS LOOK ON TRACK WITH TEMPERATURES A BIT ABOVE NORMAL IN THE MIDDLE 90S FOR THOSE LOCATIONS THAT REMAIN RAIN FREE. A FEW UPPER 90S STILL LOOK POSSIBLE ACROSS OUR GEORGIA AND ALABAMA ZONES. .DISCUSSION... 13Z WATER VAPOR AND RUC ANALYSIS SHOWING LARGE UPPER RIDGE HELPING TO BRING THE EXTREME HEAT TO PARTS OF THE CONUS CONTINUING TO SIT FROM THE SOUTHWEST U.S...ACROSS THE CENTRAL AND SOUTHERN PLAINS...AND THEN EXTENDING EAST ACROSS THE SOUTHEAST AND MID-ATLANTIC STATES. A SERIES OF WEAK SHORTWAVES ARE MOVING ACROSS THE NORTHERN STATES EMBEDDED IN THE NORTHERN STREAM FLOW. ONE OF THESE SHORTWAVES MOVING INTO THE EASTERN GREAT LAKES TO HELPING TO PUSH A COLD FRONT THROUGH THE UPPER MIDWEST AND OHIO VALLEY THAT WILL BRING AT LEAST SOME TEMPORARY RELIEF TO THE HEAT THROUGH THOSE REGIONS. GLOBAL MODELS IN AGREEMENT OF HOLDING THIS GENERAL PATTERN ACROSS NAMERICA THROUGH THURSDAY. THE UPPER RIDGE THEN LOOKS AMPLIFY WHILE IT RETROGRADES BACK TO THE WEST. THIS WILL ALLOW GENERAL UPPER LEVEL TROUGHING TO DIG INTO THE EASTERN HALF OF THE NATION BY THE UPCOMING WEEKEND. MODELS IN VERY GOOD AGREEMENT WITH THIS EAST COAST TROUGH PUSHING A FRONTAL SYSTEM INTO THE SOUTHEASTERN STATES FOR SATURDAY INTO SUNDAY. THIS ADDS BOTH MOISTURE AND DYNAMICS TO THE EQUATION...MAKING AN ACTIVE THUNDERSTORM REGIME ACROSS THE FORECAST AREA MORE AND MORE LIKELY FOR THE WEEKEND. AT THE SURFACE THE BERMUDA RIDGE AXIS LOOKS TO REMAIN ENTRENCHED ACROSS OR JUST NORTH OF THE FORECAST AREAS THROUGH THE UPCOMING WEEK. THIS WILL KEEP THE PREVAILING 1000-700MB FLOW FROM THE SOUTHEAST THROUGH THE WORK WEEK. THIS IS A FAVORABLE DIRECTION FOR AFTERNOON SEA-BREEZE THUNDERSTORMS. THE WILDCARD WILL BE THE AMOUNT OF MID-LEVEL MOISTURE AVAILABLE. AS WAS MENTIONED ABOVE...ALTHOUGH IT LOOKS FAIRLY DRY THROUGH THE MIDWEEK TIMEFRAME...AND HENCE POPS GENERALLY 10% OR SO BELOW CLIMO NORMS...BY THE VERY END OF THE WORKWEEK AND THROUGH THE WEEKEND THE MOISTURE LOOKS TO RISE BACK ABOVE NORMAL AND AFTERNOON SHWR/TSTM ACTIVITY IS LIKELY TO INCREASE AS WELL. ONLY OTHER FEATURE OF NOTE AT THIS TIME WOULD BE THE SYSTEM BEING WATCHED BY THE HURRICANE CENTER FOR POSSIBLE TROPICAL DEVELOPMENT OFF THE SOUTH CAROLINA COAST. WHILE THIS POTENTIAL SYSTEM IS NOT A THREAT TO OUR FORECAST AREA...IF SIGNIFICANT DEVELOPMENT IS EXPERIENCED THEN IT WILL POSSIBLY HAVE SOME INFLUENCE ON THE TIMING AND EVOLUTION OF THE SYNOPTIC FEATURES ALONG THE EAST COAST (FRONTAL TIMING/MOISTURE INTO THE SOUTHEAST). && .AVIATION... SOME MORNING FOG & IFR CONDITIONS AT KVLD & KDHN WILL MIX OUT BY MID-MORNING...& BRING VFR CONDITIONS OVER ALL AREAS TODAY. THIS AFTERNOON...EXPECT LOCALIZED IFR/LIFR CIGS/VSBYS WITH ISOLATED TO SCATTERED SHOWERS & TSTMS. MAINLY TEMPO GROUPS IN TAFS WITH GREATEST POTENTIAL. OVERALL LIGHT WINDS THIS MORNING OVER MUCH OF THE AREA...& INTO THIS AFTERNOON. SOME WEST TO NORTHWEST WIND OVER NORTH FL...BUT AN ONSHORE FLOW THIS AFTERNOON IS EXPECTED ALONG THE COAST. STRONGER & GUSTY WINDS WITH TSTMS. && .TAE WATCHES/WARNINGS/ADVISORIES... AL...NONE. GA...NONE. FL...NONE. && $$ AVIATION/FIRE WX...MCT PUBLIC/MARINE...BAM fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 1049 AM CDT TUE JUL 18 2006 .DISCUSSION... THIS MORNINGS CONVECTION DIVING SOUTH AND EAST NOW...WELL AWAY FROM THE FA. EVEN RESIDUAL RAIN SHOWERS COMING TO AN END OVER THE SE. 12Z SFC ANALYSIS HAD THE FRONT JUST SOUTHEAST OF THE ILLINOIS RIVER VALLEY. VERY LITTLE IN THE WAY OF MOVEMENT FOR THE FRONT...AND THAT WILL BE IMPORTANT FOR THE AFTERNOON WHEN IT COMES TO INITIATION OF CONVECTION. SLIGHT RISK FOR MOST OF THE CWA. HAVE CONFINED THE SCATTERED WORDING AND POPS TO THE EAST AND SOUTHEAST FOR NOW...WHERE THE RUC IS MAINTAINING THE MAJORITY THIS AFTERNOON. SENDING OUT AN UPDATE TO ADJUST POPS AND MAKE THE 30 A LITTLE MORE WIDESPREAD. TEMP FORECASTS ON TRACK... SLIGHT ADJUSTMENTS TO CURRENT SKY COVER AS WELL. && .PREV DISCUSSION... FORECAST CHALLENGE IS CONVECTION CHANCES TODAY AND DEALING WITH THIS HEAT WAVE THROUGH THU...WITH HOW AFTERNOON HIGH TEMPS/HEAT INDICES WILL GET. 00Z GFS IS FAVORED MODEL AGAIN THIS FORECAST PACKAGE. SHORT TERM...TODAY THROUGH FRIDAY... MCS/CONVECTION AHEAD OF A WEAK COLD FRONT OVER SOUTHERN LOWER MI INTO NW IL NEAR THE IL RIVER. HAD ISOLATED THUNDERSTORM DEVELOP NEAR KEWANEE AND MOVE ESE ACROSS STARK/MARSHALL COUNTIES BEFORE DISSIPATING OVER EASTERN WOODFORD COUNTY. CONVECTION STILL ONGOING OVER NORTHERN INDIANA NE OF LAFAYETTE. THIS CONVECTION IS CLOSER TO A 30 TO 40 KNOT SW LOW LEVEL JET AND ON THE TAIL END OF AN UPPER LEVEL SHORT WAVE OVER THE CENTRAL GREAT LAKES NEAR LOWER MI THAT IS MOVING AWAY FROM IL TODAY. A WEAKER CAP TODAY...STEEPER MID LEVEL LAPSE RATES TODAY COMBINED WITH A HOT AND HUMID AIR MASS/HIGH INSTABILITY AND WEAK DIFFLUENT UPPER LEVEL FLOW ALOFT COMBINED WITH WEAK FRONTAL BOUNDARY MOVING SOUTH INTO SE IL SHOULD DEVELOP WIDELY SCATTERED CONVECTION TODAY...ESPECIALLY OVER EAST CENTRAL IL WHERE CHANCE POPS ADDED AND SPC HAS SLIGHT CHANCE OF SEVERE FROM CLINTON NE. HAVE HIGHS AROUND 90F NE AREAS AND LOWER 90S ELSWHERE WITH SE IL BY LAWRENCEVILLE NEAR 95F. DEWPOINTS POOLING ALONG WEAK FRONTAL BOUNDARY IN THE 70S...SO AFTERNOON HEAT INDICES HIGH AGAIN RANGING FROM UPPER 90S/100F FROM I-74 NORTH TO 100 TO 105 SW AREAS. KEPT TONIGHT DRY THINKING ISOLATED CONVECTION THIS EVENING TO BE SE OF LAWRENCEVILLE. STRONG UPPER LEVEL SUBTROPICAL RIDGE BUILDS BACK INTO IL WED ALONG WITH THE HEAT AND HUMIDITY. HAVE HIGHS BACK INTO THE MID 90S AND AFTERNOON HEAT INDICES 100 TO 105...AND AROUND 105F FROM SPRINGFIELD SW WHERE CLOSE TO HEAT ADVISORY CRITERIA. MCS ACTIVITY OVER THE UPPER MS VALLEY WED TRACKS ESE INTO THE GREAT LAKES WED NIGHT AND STILL THINK QPF TO STAY NORTH OF CENTRAL IL... EXTENDED SLIGHT CHANCE OF CONVECTION THU AFTERNOON SOUTH TO NEAR I-70 AND ADDED CHANCE POPS TO EAST CENTRAL IL AROUND CHAMPAIGN AND DANVILLE. THIS IN RESONSE TO NEXT FRONTAL BOUNDARY MOVING SOUTH TOWARD CENTRAL IL LATER THU. GUIDANCE HIGHS RISE A BIT MORE ON THU INTO THE MID TO UPPER 90S. THIS IS POSSIBLE IF WE GET ENOUGH SUNSHINE WITH CAP IN PLACE AHEAD OF FRONT. THESE TEMPS COMBINED WITH DEWPOINTS IN THE 70S WOULD PUSH AFTERNOON HEAT INDICES TO 105F OR HIGHER ACROSS CENTRAL/SE IL. CONTINUED 20/30 POPS THU NIGHT WITH SLIGHT CHANCE FRI AND COOLER HIGHS 85 TO 90F AND WARMEST OVER SE IL. SPC HAS SLIGHT RISK FROM CLINTON NE AGAIN THU AFTERNOON AND THU EVENING. LONG TERM...SATURDAY THROUGH TUESDAY... NO CHANGES MADE TO EXTENDED FORECAST AS UPPER LEVEL TROF DIGS ACROSS THE NE THIRD OF THE U.S. AND SUBTROPICAL RIDGE RETREATS SW INTO THE ROCKIES WITH IL IN A COOLER NW UPPER LEVEL FLOW. KEPT A DRY FORECAST GOING THOUGH DGEX AND LRGFS IS SHOWING QPF FRI NIGHT/SAT WITH SHORT WAVE TROF DIGGING ACROSS THE GREAT LAKES. THIS WILL NEED TO BE WATCHED. HAVE HIGHS NEAR NORMAL IN THE MID TO UPPER 80S AND THINK NEW MEX HIGHS IN THE 70S TOO COOL SAT SINCE GFSLR IS MORE AGGRESSIVE WITH SHORT WAVE AND ITS CLOUDS/CONVECTION SAT. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ HJS/HUETTL il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CLEVELAND OHIO 704 AM EDT TUE JUL 18 2006 .AVIATION(12Z-12Z)... CONVECTION DIVING S IN INDIANA CUTTING OFF SWLY INFLOW INTO NRN OH. RAIN SHIELD BHD THE CONVECTION IN LWR MI HAS BEEN TRYING TO MOV SE ACRS NRN OH BUT HAS BEEN ERODING ON THE LEADING EDGE THUS RESULTING IN OVERALL SHRINKAGE AND DISSIPATION. BLV THIS WL CONT THIS MORN THEN WK CDFNT MOVG S THRU THE AREA WL TRIGGER SCT SHRA AND TSRA MIDDAY TDA BUT MOST ACTIVITY SHUD BE S OF TAF SITES ACCORDING TO MODEL DATA. CONDS SHUD STAY VFR OUTSIDE OF CONVECTIVE PRECIP ALTHO THERE CUD BE SOME 4 OR 5SM BR/HZ FIRST FEW HRS AFT 12Z SO WL WATCH LATEST OBS TO DETERMINE WHERE THIS IS HAPPENING. CLDS WL CONT TO CLEAR OUT LATER TDA AND EARLY TNGT. SOMEWHAT DRIER AIR MOVING IN SHUD PREVENT MOST IF NOT ALL FOG LATE TNGT. && .SHORT TERM(TODAY THROUGH WEDNESDAY NIGHT)... CONVECTION IS SHOWING SOME SIGNS OF WEAKENING AS IT MOVES THROUGH THE FORECAST AREA DURING THE EARLY MORNING HOURS. THE COLD FRONT SHOULD BE ACROSS THE EXTREME NORTH BY 14Z AND THEN JUST SOUTH OF THE FORECAST AREA BY 18Z. THE PROBLEM IS THE WRF/NAM AND IS TRYING TO HINT AT AN INVERTED TROF WITH SOME MOISTURE HANGING BACK OVER THE NORTHWEST PORTION OF THE FORECAST. ON THE EDGE WHETHER THIS IS CORRECT THE HIGH PRESSURE TO THE NORTH SEEMS LIKE IT SHOULD BE DOMINATE. THE 06Z RUC IS HINTING AT SOME MOISTURE HANGING BACK IN THE NORTH AT 18Z BUT THE FRONT IS JUST SOUTH OF THE AREA. WILL TRY TO PLAY THRU EARLY AFTERNOON EXTREME NORTH AND THEN NO TIMING ELSEWHERE. THE AIRMASS IN THE SOUTHERN PORTION OF THE CWA IS VERY UNSTABLE BY 16Z BUT THE BOUNDARY MAY BE RIGHT ON THEM OR JUST SOUTH. WITH TIMING QUESTIONS WILL NOT MENTION SEVERE IN THE ZONES/GRIDS BUT JUST ON THE OUTLOOK. MAXIMUM TEMPERATURES TOUGH FOR TODAY...GOING WITH GUIDANCE. TONIGHT IT SHOULD DRY OUT RAPIDILY BECOMING MOSTLY CLEAR. DRY WEATHER LOOKS GOOD WEDNESDAY AND WEDNESDAY NIGHT. GUIDANCE TEMPERATURES OK. && .LONG TERM (THU THRU MON)... NO REAL CHANGES TO THE EXTENDED. SOME CONCERNS ABOUT SUNDAY USING THE 00Z GFS. THE ECMWF IS TRYING TO SAY DRY WITH HIGH PRESSURE IN THE AREA. ATTM NOT BEING REAL CONFIDENT WILL JUST GO A 20 POP. DID INCREASE THE POP TO 50% THURSDAY NIGHT AS THAT LOOKS REASONABLE BASED ON THE CONSISTENT FRONTAL TIMING AND MOISTURE. PREVIOUS EXTENDED DISCUSSION... NOT MUCH HAS CHANGED AS MODELS CONTINUE TO SHOW LITTLE RUN TO RUN CONTINUITY. AS A RESULT CONFIDENCE REMAINS LOW WITH SPECIFIC DETAILS. CONSENSUS IS THAT GENERAL TROFINESS WILL CONT ACRS ERN CONUS WITH A SERIES OF FRONTAL SYSTEMS EXPECTED TO AFFECT FORECAST AREA. FIRST OF THESE WILL AFFECT AREA THU WITH WARM FRONTAL PASSAGE DURING DAY FOLLOWED BY A COLD FRONT THU NIGHT INTO FRI. THERE COULD ACTUALLY BE A DECENT AMOUNT OF RAIN ON THU AS MCS FROM THE WRN LAKES MOVES E ACROSS NRN OH AND INTERACTS WITH WARM FRONT. HIGH PRES WILL BRIEFLY BUILD IN SAT AND SUN BUT ANOTHER COLD FRONT WILL DIVE S ACROSS AREA MON. UNLIKE...THU/FRI SYSTEM...THIS ONE WILL LIKELY BE RELATIVELY DRY. HUMID CONDITIONS WILL CONT FOR MOST OF THE PERIOD. TEMPS WILL AVERAGE NEAR NORMAL ON SAT AND SUN BUT OTHERWISE WILL BE ABOVE NORMAL. && .CLE WATCHES/WARNINGS/ADVISORIES... .OH...NONE. .PA...NONE. && $$ SHORT TERM...KIELTYKA LONG TERM...KUBINA/KIELTYKA AVIATION...ADAMS oh AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE CLEVELAND OHIO 640 AM EDT TUE JUL 18 2006 .SHORT TERM (TODAY)... PCPN WITH THE SHORTWAVE NOT MAKING MUCH EASTWARD PROGRESS. DID SOME UPDATING TO PUT SOME TIMING IN. STILL AN ISSUE WITH THE SEVERE WEATHER THREAT...WHERE WILL THE FRONT BE LOCATED. 09Z RUC IS STILL SHOWING A VERY UNSTABLE AIRMASS INLAND OF THE LAKES BY 18Z. .SHORT TERM(TODAY THROUGH WEDNESDAY NIGHT)... CONVECTION IS SHOWING SOME SIGNS OF WEAKENING AS IT MOVES THROUGH THE FORECAST AREA DURING THE EARLY MORNING HOURS. THE COLD FRONT SHOULD BE ACROSS THE EXTREME NORTH BY 14Z AND THEN JUST SOUTH OF THE FORECAST AREA BY 18Z. THE PROBLEM IS THE WRF/NAM AND IS TRYING TO HINT AT AN INVERTED TROF WITH SOME MOISTURE HANGING BACK OVER THE NORTHWEST PORTION OF THE FORECAST. ON THE EDGE WHETHER THIS IS CORRECT THE HIGH PRESSURE TO THE NORTH SEEMS LIKE IT SHOULD BE DOMINATE. THE 06Z RUC IS HINTING AT SOME MOISTURE HANGING BACK IN THE NORTH AT 18Z BUT THE FRONT IS JUST SOUTH OF THE AREA. WILL TRY TO PLAY THRU EARLY AFTERNOON EXTREME NORTH AND THEN NO TIMING ELSEWHERE. THE AIRMASS IN THE SOUTHERN PORTION OF THE CWA IS VERY UNSTABLE BY 16Z BUT THE BOUNDARY MAY BE RIGHT ON THEM OR JUST SOUTH. WITH TIMING QUESTIONS WILL NOT MENTION SEVERE IN THE ZONES/GRIDS BUT JUST ON THE OUTLOOK. MAXIMUM TEMPERATURES TOUGH FOR TODAY...GOING WITH GUIDANCE. TONIGHT IT SHOULD DRY OUT RAPIDILY BECOMING MOSTLY CLEAR. DRY WEATHER LOOKS GOOD WEDNESDAY AND WEDNESDAY NIGHT. GUIDANCE TEMPERATURES OK. && .LONG TERM (THU THRU MON)... NO REAL CHANGES TO THE EXTENDED. SOME CONCERNS ABOUT SUNDAY USING THE 00Z GFS. THE ECMWF IS TRYING TO SAY DRY WITH HIGH PRESSURE IN THE AREA. ATTM NOT BEING REAL CONFIDENT WILL JUST GO A 20 POP. DID INCREASE THE POP TO 50% THURSDAY NIGHT AS THAT LOOKS REASONABLE BASED ON THE CONSISTENT FRONTAL TIMING AND MOISTURE. PREVIOUS EXTENDED DISCUSSION... NOT MUCH HAS CHANGED AS MODELS CONTINUE TO SHOW LITTLE RUN TO RUN CONTINUITY. AS A RESULT CONFIDENCE REMAINS LOW WITH SPECIFIC DETAILS. CONSENSUS IS THAT GENERAL TROFINESS WILL CONT ACRS ERN CONUS WITH A SERIES OF FRONTAL SYSTEMS EXPECTED TO AFFECT FORECAST AREA. FIRST OF THESE WILL AFFECT AREA THU WITH WARM FRONTAL PASSAGE DURING DAY FOLLOWED BY A COLD FRONT THU NIGHT INTO FRI. THERE COULD ACTUALLY BE A DECENT AMOUNT OF RAIN ON THU AS MCS FROM THE WRN LAKES MOVES E ACROSS NRN OH AND INTERACTS WITH WARM FRONT. HIGH PRES WILL BRIEFLY BUILD IN SAT AND SUN BUT ANOTHER COLD FRONT WILL DIVE S ACROSS AREA MON. UNLIKE...THU/FRI SYSTEM...THIS ONE WILL LIKELY BE RELATIVELY DRY. HUMID CONDITIONS WILL CONT FOR MOST OF THE PERIOD. TEMPS WILL AVERAGE NEAR NORMAL ON SAT AND SUN BUT OTHERWISE WILL BE ABOVE NORMAL. && .AVIATION(06Z-06Z)... BAND OF TSRA WITH CDFNT IN LWR MI CONT TO WKN AS IT MOVD INTO LERI SO NOT SURE IF ANYTHING CAN HOLD TOGETHER LONG ENUF TO REACH ANY TAF SITES SO WL ONLY FCST ANY TSRA THAT LOOKS IMMINENT AT TAF TIME. BEST THREAT WUD OBVIOUSLY APPEAR TO BE FOR TOL AND FDY NEXT FEW HRS. BAND OF MSTR WITH CDFNT WL CONT TO SAG S INTO THE AREA TDA. OUTSIDE OF ANY TSRA...CIGS AND VSBY'S SHUD RMN VFR. && .CLE WATCHES/WARNINGS/ADVISORIES... .OH...NONE. .PA...NONE. && $$ SHORT TERM...KIELTYKA LONG TERM...KUBINA/KIELTYKA AVIATION...ADAMS oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 345 PM EDT TUE JUL 18 2006 .SYNOPSIS... 19Z WATER VAPOR AND RUC ANALYSIS SHOWING LARGE UPPER RIDGE HELPING TO BRING THE EXTREME HEAT TO PARTS OF THE CONUS CONTINUING TO SIT FROM THE SOUTHWEST U.S...ACROSS THE CENTRAL AND SOUTHERN PLAINS...AND THEN EXTENDING EAST ACROSS THE SOUTHEAST AND MID-ATLANTIC STATES. A SERIES OF WEAK SHORTWAVES ARE MOVING ACROSS THE NORTHERN STATES EMBEDDED IN THE NORTHERN STREAM FLOW. ONE OF THESE SHORTWAVES MOVING INTO THE NORTHEAST STATES IS TO HELPING TO PUSH A COLD FRONT OUT OF THE UPPER MIDWEST AND OHIO VALLEY THAT WILL BRING AT LEAST SOME TEMPORARY RELIEF TO THE HEAT THROUGH THOSE REGIONS. GLOBAL MODELS IN AGREEMENT OF HOLDING THIS GENERAL PATTERN ACROSS NAMERICA THROUGH THURSDAY. THE UPPER RIDGE THEN LOOKS AMPLIFY WHILE IT RETROGRADES BACK TO THE WEST. THIS WILL ALLOW GENERAL UPPER LEVEL TROUGHING TO DIG INTO THE EASTERN HALF OF THE NATION BY THE UPCOMING WEEKEND. MODELS IN VERY GOOD AGREEMENT WITH THIS EAST COAST TROUGH PUSHING A FRONTAL SYSTEM INTO THE SOUTHEASTERN STATES FOR SATURDAY INTO SUNDAY. THIS ADDS BOTH MOISTURE AND DYNAMICS TO THE EQUATION...MAKING AN ACTIVE THUNDERSTORM REGIME ACROSS THE FORECAST AREA MORE AND MORE LIKELY FOR THE WEEKEND. AT THE SURFACE THE BERMUDA RIDGE AXIS LOOKS TO REMAIN ENTRENCHED ACROSS OR JUST NORTH OF THE FORECAST AREAS THROUGH THE UPCOMING WEEK. THIS WILL KEEP THE PREVAILING 1000-700MB FLOW FROM THE EAST ON ON WEDNESDAY...THEN COMING AROUND TO THE SOUTHEAST FOR THE END OF THE WORK WEEK. THIS IS A FAVORABLE DIRECTION FOR AFTERNOON SEA-BREEZE THUNDERSTORMS. THE WILDCARD WILL BE THE AMOUNT OF MID-LEVEL MOISTURE AVAILABLE. AS WAS MENTIONED ABOVE...ALTHOUGH IT LOOKS FAIRLY DRY THROUGH THE MIDWEEK TIMEFRAME...AND HENCE POPS GENERALLY 10% OR SO BELOW CLIMO NORMS...BY THE VERY END OF THE WORKWEEK AND THROUGH THE WEEKEND THE MOISTURE LOOKS TO RISE BACK ABOVE NORMAL AND AFTERNOON SHWR/TSTM ACTIVITY IS LIKELY TO INCREASE AS WELL. GOING INTO MORE DETAIL FOR EACH UPCOMING DAY...WILL BE LEANING MORE TO THE NAM FOR THE FORECAST OVER THE NEXT 36 HOURS OR SO. BELIEVE THE GFS IS LOSING THE MIDLEVEL AIR TO FAST DURING THE DAY...RESULTING IN A MUCH BETTER CONVECTIVE PROFILE..ESPECIALLY LATE IN THE DAY. THE GFS BEHAVED SIMILAR WITH THE PREVIOUS DRYSPELL. THE GUIDANCE COMES BACK MORE INTO LINE BY THURSDAY AND THEN WILL BE USING MORE OF A BLEND. WEDNESDAY...WITH A LACK OF SIGNIFICANT CONVECTION AND THE RIDGE OVERHEAD...TEMPERATURES WILL BE QUITE HOT WITH MIDDLE AND UPPER 90S A GOOD BET ACROSS INLAND LOCATIONS. COMBINED WITH FAIRLY MOIST LOWLEVELS WILL RESULT IN HEAT INDICES OF BETWEEN 100 AND 105. LATEST NAM FORECAST SOUNDING PROFILES FOR THE AREA ON WEDNESDAY...ADD MORE CONFIDENCE TO LOW POPS. ALTHOUGH CAPE ARE NOT THAT IMPRESSIVE WITH BETWEEN 1300-1700 J/KG ACROSS THE REGION AND LIS AROUND -3.4C (WHICH IS CERTAINLY ENOUGH TO GET AFTERNOON CONVECTION)...THE COLUMN IS VERY DRY ABOVE AROUND 700MB RESULTING IN LOW PW VALUES AROUND 1.3-1.4" (~75% OF NORMAL). THIS DRY MIDLEVEL AIR SHOULD HELP TO SUPPRESS CONVECTION TO WDLY SCATTERED SEABREEZE ACTIVITY. WITH THIS IN MIND FELT DROPPING POPS ANOTHER 10% TO THE SLIGHT CHANCE CATEGORY ACROSS MOST OF AL/GA ZONES WAS IN ORDER. WILL LEAVE THE 30 POPS (STILL 10-20% BELOW CLIMO) ACROSS NORTH FLORIDA TO ACCOUNT FOR ANY SEABREEZE ACTIVITY. ANY CONVECTION SHOULD QUICKLY DIMINISH AFTER SUNSET WEDNESDAY EVENING WITH THE EXCEPTION OF ANY TYPICAL OFFSHORE NOCTURNAL CONVECTION AS MOISTURE LEVELS WILL ALREADY BE RAPIDLY INCREASING JUST SOUTH OF THE COAST DURING THE NIGHT. THURSDAY...NOT THINKING ABOUT MAKING MANY CHANGES TO GOING FORECAST. 1000-700MB MEAN FLOW COMES AROUND TO THE SOUTHEAST AND RAPIDLY BRINGS MOISTURE ADVECTION BACK INTO THE REGION. PW VALUES ACROSS NORTH FLORIDA ARE BACK BY THE END OF THE DAY WITH CAPE VALUES CLOSER TO 2000 J/KG. THE MOISTURE RETURN MAY BE JUST A BIT SLOW TO SIGNIFICANTLY IMPACT AFTERNOON CONVECTION...EXCEPT ACROSS THE FAR EASTERN PANHANDLE AND BIG BEND. TO THE NORTH AND WEST A BIT OF DRY AIR MAY LINGER LONG ENOUGH TO SUPPRESS CONVECTION. CAPE VALUES ARE GENERALLY 1500-1700 J/KG WITH PW VALUES AROUND 1.5"...REGARDLESS OF THESE FACTORS...FEEL AT LEAST WDLY SCATTERED ACTIVITY WILL DEVELOP ACROSS OUR WESTERN AND NORTHERN ZONES WITH MORE SCATTERED ACTIVITY TO THE EAST. FRIDAY...MOISTURE LOOKS TO BE FULLY ENTRENCHED INTO THE FORECAST AREA BY FRIDAY AFTERNOON. MODIFIED GFS SOUNDINGS FOR 90/71 WHICH STILL MAY BE A BIT COOL ON BOTH TEMP AND DEWPOINT GIVES AROUND 2600 J/KG OF CAPE WITH AN LI OF -5C AND A PW WATER VALUE OF 2.02 (~120% OF NORMAL). CURRENT FORECAST OF 30 POPS NORTH AND 40-50 POPS SOUTH LOOKS ON TRACK. ONLY OTHER FEATURE OF NOTE AT THIS TIME WOULD BE THE SYSTEM UPGRADED TO TROPICAL DEPRESSION #2 BY THE HURRICANE CENTER OFF THE SOUTH CAROLINA COAST. WHILE THIS SYSTEM IS NOT A THREAT TO OUR FORECAST AREA...IF SIGNIFICANT DEVELOPMENT IS EXPERIENCED THEN IT WILL POSSIBLY HAVE SOME INFLUENCE ON THE TIMING AND EVOLUTION OF THE SYNOPTIC FEATURES ALONG THE EAST COAST (FRONTAL TIMING/MOISTURE INTO THE SOUTHEAST). && .MARINE... HIGH PRESSURE CENTERED OVER THE COASTAL WATERS WILL SETTLE SLOWLY SOUTHWEST THROUGH WEDNESDAY. THE BERMUDA HIGH RIDGE AXIS WILL BUILD EAST ACROSS THE FORECAST AREA ON THURSDAY AND THURSDAY NIGHT...THEN SHIFT NORTH OF THE COASTAL WATERS ON FRIDAY. THE RIDGE IS FORECAST TO SETTLE BACK SOUTH OVER THE UPCOMING WEEKEND AS A WEAK FRONT MOVES INTO THE SOUTHEAST UNITED STATES. WINDS AND WAVES ARE EXPECTED TO REMAIN BELOW CAUTION LEVELS THROUGH THE REMAINDER OF THE WEEK...BUT WILL BE LOCALLY HIGHER NEAR THE COAST EACH AFTERNOON WITH SEABREEZE DEVELOPMENT. && .FIRE WX... AFTERNOON SHOWERS AND THUNDERSTORMS ARE EXPECTED FOR THE NEXT SEVERAL DAYS. RELATIVE HUMIDITIES ACROSS THE AREA ARE NOT EXPECTED TO REACH RED FLAG CONDITIONS. && .AVIATION... EXPECTING VFR CONDITIONS FOR THE REMAINDER OF TODAY. MID-LEVEL DRY AIR IS KEEPING THUNDERSTORM COVERAGE TO A MINIMUM, SO TEMPO GROUPS HAVE BEEN REMOVED AND REPLACED WITH ONLY VICINITY THUNDERSTORMS AT ALL TAF SITES. EXPECTING THE VFR CONDITIONS TO CONTINUE OVERNIGHT. HOWEVER, MVFR VSBYS ARE POSSIBLE WITH PATCHY DENSE FOG NEAR TLH, DHN, AND ABY. NEAR VLD TEMPORARY IFR VSBYS AND CIGS ARE POSSIBLE ASSOCIATED WITH DENSER FOG IN THAT AREA DURING THE EARLY MORNING HOURS. ONCE THE FOG LIFTS OUT OF THE AREA, A RETURN TO VFR CONDITIONS IS EXPECTED FOR THE REMAINDER OF THE PERIOD WITH ISOLATED SHOWERS AND THUNDERSTORMS EXPECTED WEDNESDAY AFTERNOON. && .PRELIMINARY POINT TEMPS/POPS... TALLAHASSEE 74 96 74 94 / 20 30 20 30 PANAMA CITY 78 92 77 92 / 20 20 20 20 DOTHAN 75 97 74 96 / 20 20 20 20 ALBANY 75 98 74 97 / 20 20 20 20 VALDOSTA 73 97 72 94 / 20 20 20 30 CROSS CITY 73 95 73 92 / 20 30 20 40 && .TAE WATCHES/WARNINGS/ADVISORIES... AL...NONE. GA...NONE. FL...NONE. && $$ AVIATION/FIRE WX...MCT PUBLIC/MARINE...BAM fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 225 PM MDT TUE JUL 18 2006 .DISCUSSION...WATER VAPOR IMAGERY CONTINUES TO INDICATE LARGE RIDGE OF HIGH PRESSURE EXTENDING ACROSS THE SOUTHERN CONUS. AT THE SFC LOW WAS IN EASTERN WYOMING/WESTERN SD WITH TROUGH EXTENDING SOUTH INTO NORTHEAST COLORADO. FRONTAL BOUNDARY WAS LOCATED ROUGHLY ALONG A YUMA-GOODLAND-LAKIN LINE AND WAS SLOWLY DRIFTING NORTHEAST. TONIGHT...WARM FRONT WILL CONTINUE TO LIFT TO THE NORTHEAST TONIGHT...IN RESPONSE TO SHORTWAVE TROUGH/PRESSURE FALLS OVER SOUTH DAKOTA. LOTS OF INSTABILITY AVAILABLE...ALTHOUGH ML CINH IS VERY STRONG. TOUGH CALL ON WHETHER OR NOR FRONTAL CONVERGENCE/ISENTROPIC ASCENT NORTH OF THE BOUNDARY WILL BE ABLE TO SPARK A STORM OR NOT...AND WILL LIKELY MAKE A LAST MINUTE DECISION ON THIS. FURTHER WEST...STRONGER CONVERGENCE ALONG SFC TROUGH ACROSS NEB PANHANDLE SHOULD ALLOW FOR TSTM DEVELOPMENT...AND MAY BRUSH WESTERN CWA. ALSO SEEING SOME ISOLATED THUNDERSTORMS DEVELOPING TO THE SOUTHEAST...RUC AS WEAK CONVERGENCE AXIS STRECHING NORTH FROM THIS AREA INTO SOUTHEAST CWA WITH WEAKNESS IN CINH FIELD...AND MAY SEE AN ISOLATED STORM DEVELOP IN THIS AREA. WEDNESDAY...TEMPS ALOFT CONTINUE TO WARM AS SOUTHWESTERLY FLOW DEVELOPS AT THE SFC. FRONTAL BOUNDARY WILL BEGIN TO SLOWLY MOVE SOUTH DURING THE EVENING. STILL NOT TOTALLY SOLD ON THUNDER CHANCES AS FRONT WILL BE MOVING INTO A VERY WELL MIXED AND DRY AIRMASS...BUT ISOLATED MENTION STILL LOOKS REASONABLE AND WILL ONLY MODIFY SLIGHTLY. THURSDAY-FRIDAY...FRONTAL BOUNDARY WILL ONCE AGAIN STALL ACROSS THE SOUTHERN CWA ON THURSDAY MORNING BEFORE SLOWLY LIFTING NORTH IN RESPONSE TO APPROACHING TROUGH. EASTERLY FLOW SHOULD HELP MAINTAIN HIGHER DEWPOINTS DURING THE AFTERNOON...RESULTING IN PLENTY OF INSTABILITY AND A WEAK CAP...PARTICURALY IN EASTERN COLORADO. WILL HAVE POPS ALONG FRONTAL BOUNDARY DURING THE AFTERNOON...BUT WILL LIKELY SEE INITIATION ACROSS EASTERN COLORADO WHERE UPSLOPE FLOW WILL AID FRONTAL CONVERGENCE. AS FRONT LIFTS NORTH...BROAD AREA OF STRONG WAA SETS UP TO THE NORTH OF THE FRONT. LIFT IS FAIRLY DEEP...SHOWING UP ALL THE WAY TO H5 SO WILL LIKELY SEE THUNDERSTORMS CONTINUE THROUGH THE NIGHT. LOTS OF ELEVATED INSTABILITY AVAILABLE WITH CAP WEAKEST IN THE NORTHWEST...AND REORIENTED POPS ACCORDINGLY. STRONG SHORTWAVE TROUGH AND ACCOMPANYING COLD FRONT WILL SLIDE OVER THE AREA ON FRIDAY. SHOULD SEE STRONG FORCING THROUGHOUT THE DAY BEFORE SYSTEM LEAVES AREA FRIDAY NIGHT...BUT RATHER SIGNIFICANT TIMING DIFFERENCES EXISTS IN THE OPERATIONAL MODELS. WILL KEEP THINGS AT CHANCE CATEGORY FOR NOW BUT IF FRONT/WAVE ARE A LITTLE SLOWER AND MOVE OVER AREA IN THE AFTERNOON COULD SEE MORE WIDESPREAD PRECIP. IN THE EXTENDED (SAT-TUES)...MEDIUM RANGE MODELS ALL BEGINNING TO COME INTO FAIRLY GOOD AGREEMENT NOW WITH RIDGE RETROGRADING TO THE WEST AND STRONG COLD FRONT MOVING ACROSS THE AREA BRINGING SOME RELIEF TO THE HEAT. MAIN FORECAST CONCERNS WILL PRIMARILY BE TEMPERATURES AS BRIEF WINDOW OF BELOW NORMAL TEMPS APPEARS LIKELY EARLY IN THE PERIOD...BEFORE RIDGING AND WARMING BEGINS TO SET IN AGAIN. FOR WX...CUT BACK ON POPS THROUGHOUT THE PERIOD AS FRONT LOOKS TO HAVE MADE IT ALL THE WAY THROUGH THE CWA BY SATURDAY LEAVING A RATHER COOL AND STABLE AIRMASS IN ITS PLACE. COULD SEE A RETURN OF THUNDERSTORMS TO THE AREA BY TUESDAY AS LEE TROUGH DEVELOPS AND MID LEVEL DESTABILIZE...BUT CONFIDENCE TO LOW TO INCLUDE POPS AT THIS TIME. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$ JRM ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CLEVELAND OHIO 1259 PM EDT TUE JUL 18 2006 .AVIATION(18Z-18Z)... COLD FRONT JUST ABOUT THROUGH THE FORECAST AREA AT THIS POINT...WITH ALL SITES SEEING WINDS COMING AROUND OUT OF THE NORTHEAST. SOMEWHAT DRIER AIR WORKING IN FROM THE NORTH...BUT STILL SEEING CLOUDS HANGING ON BEHIND THE FRONT IN THE COOLER AIR. ALL LOCATIONS VFR...BUT A FEW SHOWING SCATTERED CLOUDS UNDER 3000 FT. AS FRONT CONTINUES TO PUSH SOUTH AND HIGH PRESSURE BUILDS IN FROM ONTARIO...EXPECT SKIES TO GRADUALLY CLEAR BY THIS EVENING. WINDS WILL CONTINUE TO SWING AROUND OUT OF THE EAST BY MORNING WITH ONLY A FEW CIRRUS BY THE END OF THE PERIOD. HAVE CONTINUED WITH A DRY FORECAST...MODELS STILL CATCHING UP FROM THEIR PREVIOUS FORECAST OF RAINFALL THIS MORNING. WITH FRONT SOUTH OF ALL TERMINALS...FEEL THAT IT WILL BE DIFFICULT TO SEE WIDESPREAD SHOWERS THIS AFTERNOON. ONLY OTHER ITEM OF NOTE IS LIGHT FOG POSSIBLE AT THE SOUTHERN-MOST TERMINALS OF YNG AND CAK TOWARD DAYBREAK. SURFACE DEWPOINTS WILL BE HIGHEST IN THESE AREAS AND CANT RULE OUT A LITTLE FOG AROUND 09Z. COVERED THIS WITH A TEMPO GROUP...WILL RE-EVALUATE WITH 00Z ISSUANCE. && .SHORT TERM(TODAY THROUGH WEDNESDAY NIGHT)... CONVECTION IS SHOWING SOME SIGNS OF WEAKENING AS IT MOVES THROUGH THE FORECAST AREA DURING THE EARLY MORNING HOURS. THE COLD FRONT SHOULD BE ACROSS THE EXTREME NORTH BY 14Z AND THEN JUST SOUTH OF THE FORECAST AREA BY 18Z. THE PROBLEM IS THE WRF/NAM AND IS TRYING TO HINT AT AN INVERTED TROF WITH SOME MOISTURE HANGING BACK OVER THE NORTHWEST PORTION OF THE FORECAST. ON THE EDGE WHETHER THIS IS CORRECT THE HIGH PRESSURE TO THE NORTH SEEMS LIKE IT SHOULD BE DOMINATE. THE 06Z RUC IS HINTING AT SOME MOISTURE HANGING BACK IN THE NORTH AT 18Z BUT THE FRONT IS JUST SOUTH OF THE AREA. WILL TRY TO PLAY THRU EARLY AFTERNOON EXTREME NORTH AND THEN NO TIMING ELSEWHERE. THE AIRMASS IN THE SOUTHERN PORTION OF THE CWA IS VERY UNSTABLE BY 16Z BUT THE BOUNDARY MAY BE RIGHT ON THEM OR JUST SOUTH. WITH TIMING QUESTIONS WILL NOT MENTION SEVERE IN THE ZONES/GRIDS BUT JUST ON THE OUTLOOK. MAXIMUM TEMPERATURES TOUGH FOR TODAY...GOING WITH GUIDANCE. TONIGHT IT SHOULD DRY OUT RAPIDLY BECOMING MOSTLY CLEAR. DRY WEATHER LOOKS GOOD WEDNESDAY AND WEDNESDAY NIGHT. GUIDANCE TEMPERATURES OK. && .LONG TERM (THU THRU MON)... NO REAL CHANGES TO THE EXTENDED. SOME CONCERNS ABOUT SUNDAY USING THE 00Z GFS. THE ECMWF IS TRYING TO SAY DRY WITH HIGH PRESSURE IN THE AREA. ATTM NOT BEING REAL CONFIDENT WILL JUST GO A 20 POP. DID INCREASE THE POP TO 50% THURSDAY NIGHT AS THAT LOOKS REASONABLE BASED ON THE CONSISTENT FRONTAL TIMING AND MOISTURE. PREVIOUS EXTENDED DISCUSSION... NOT MUCH HAS CHANGED AS MODELS CONTINUE TO SHOW LITTLE RUN TO RUN CONTINUITY. AS A RESULT CONFIDENCE REMAINS LOW WITH SPECIFIC DETAILS. CONSENSUS IS THAT GENERAL TROFINESS WILL CONT ACRS ERN CONUS WITH A SERIES OF FRONTAL SYSTEMS EXPECTED TO AFFECT FORECAST AREA. FIRST OF THESE WILL AFFECT AREA THU WITH WARM FRONTAL PASSAGE DURING DAY FOLLOWED BY A COLD FRONT THU NIGHT INTO FRI. THERE COULD ACTUALLY BE A DECENT AMOUNT OF RAIN ON THU AS MCS FROM THE WRN LAKES MOVES E ACROSS NRN OH AND INTERACTS WITH WARM FRONT. HIGH PRES WILL BRIEFLY BUILD IN SAT AND SUN BUT ANOTHER COLD FRONT WILL DIVE S ACROSS AREA MON. UNLIKE...THU/FRI SYSTEM...THIS ONE WILL LIKELY BE RELATIVELY DRY. HUMID CONDITIONS WILL CONT FOR MOST OF THE PERIOD. TEMPS WILL AVERAGE NEAR NORMAL ON SAT AND SUN BUT OTHERWISE WILL BE ABOVE NORMAL. && .CLE WATCHES/WARNINGS/ADVISORIES... .OH...NONE. .PA...NONE. && $$ SHORT TERM...KIELTYKA LONG TERM...KUBINA/KIELTYKA AVIATION...LEINS oh AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 125 PM EDT TUE JUL 18 2006 .UPDATE /THIS AFTERNOON/... ISSUED AN UPDATE TO INCLUDE THE SEVERE THUNDERSTORM WATCH HEADLINE IN THE ZFP FOR PORTIONS OF OUR CWA. ALSO INCREASING POPS FROM PHILADELPHIA NORTH AND WEST INTO THE SCATTERED CATEGORY. WE ARE MONITORING THE BUILDING CU FIELD FROM NORTHEAST PENNSYLVANIA ON SOUTHWESTWARD AHEAD OF A WEAK COLD FRONT AND ALSO AN OUTFLOW BOUNDARY. LAPS ANALYSIS INDICATING A WEALTH OF SURFACE BASED CAPE ACROSS THE CWA, WITH VALUES AS OF 16Z NEARING 3000 J/KG ACROSS OUR FAR NORTHWESTERN COUNTIES. CONVECTIVE INITIATION APPEARS TO BE MAINLY FOCUSED NEAR THE OUTFLOW BOUNDARY MOVING SOUTHEASTWARD INTO THE SOUTHERN POCONOS ATTM. TIMING FARTHER TO THE SOUTHEAST APPEARS TO BE LATE THIS AFTERNOON WITH THE RUC POINTING AROUND THE 20-21Z TIME FRAME CLOSER TO PHILADELPHIA. WITH THE AMOUNT OF CAPE, SOME RATHER ROBUST UPDRAFTS WILL OCCUR, INCREASING THE THREAT FOR DAMAGING WINDS. THE FREEZING LEVEL IS RATHER HIGH /THIS LEVEL HAS RECENTLY BEEN ADJUSTED IN THE KDIX 88D/. HOWEVER WITH ANY STRONG UPDRAFTS, SEVERE HAIL CANNOT BE RULED OUT. STORMS SHOULD BE EFFICIENT IN PRODUCING LOCALLY HEAVY RAINFALL, THEREFORE ADDED THIS INTO THE GRIDS AND ZFP. OTHERWISE, THE HEAT REMAINS THE TOP STORY THIS AFTERNOON WITH 17Z HEAT INDICES AROUND 100 DEGREES AT MANY REPORTING STATIONS. UPDATED GRIDS, ZFP, AFM AND PFM HAVE ALREADY BEEN ISSUED. THAT IS ALL FOR NOW. STAY COOL! && .PREVIOUS DISCUSSION... ISSUED /445 AM EDT TUE JUL 18 2006/ .SHORT TERM /TODAY THROUGH THURSDAY/... TODAY SHOULD BE THE FINAL DAY OF THE OPPRESSIVE HEAT IN OUR REGION. TEMPS ARE EXPECTED TO RISE TO LEVELS SIMILAR TO THOSE RECORDED ON MONDAY. HOWEVER, DEW POINTS TEMPS ARE FORECAST TO BE A LITTLE HIGHER THAN THOSE ON MONDAY WHEN SOME DRIER AIR MIXED DOWN FROM ALOFT. AT 4:00 AM, DEW POINT TEMPS WERE GENERALLY RIGHT AROUND THE 70 DEGREE MARK THROUGHOUT OUR REGION. THERE IS A FAIRLY DRY LAYER OF AIR BETWEEN 850 AND 700 MB. WHILE SOME DRY AIR MAY MIX DOWN FROM ALOFT FOR A TIME TODAY, ESPECIALLY IN OUR CENTRAL AND SOUTHERN COUNTIES, DEW POINT TEMPS SHOULD RECOVER TO AT LEAST THE UPPER 60S IN THE GENERAL SOUTHWEST SURFACE FLOW. BASED ON OUR FORECAST TEMPS AND DEW POINT TEMPS, WE FOUND IT NECESSARY TO MAKE SOME ADJUSTMENTS TO THE HEAT WARNINGS AND ADVISORIES. FOR CARBON AND MONROE COUNTY WE FOUND IT DIFFICULT TO JUSTIFY THE HEAT ADVISORY. IN THE POCONO REGION, TEMPS MIGHT ACTUALLY BE A DEGREE OR TWO COOLER TODAY THAN THOSE OF YESTERDAY WITH THE POTENTIAL FOR A LITTLE MORE CLOUD COVER. ALSO, THERE COULD BE SOME LATE AFTERNOON CONVECTION THERE. WE'VE MAINTAINED THE EXCESSIVE HEAT WARNING FOR THE PHL METRO AREA BASED ON THE LOCAL KALKSTEIN CRITERIA. HOWEVER, FOR ALL OTHER AREAS (EXCEPT THE JERSEY SHORE AND THE DELAWARE BEACHES) WE'VE GONE WITH A HEAT ADVISORY BASED ON EXPECTED HEAT INDEX VALUES AND THE DIFFERENT CRITERIA. MEANWHILE, A COLD FRONT EXTENDED SOUTHWESTWARD FROM LOWER ONTARIO, ACROSS SOUTHERN MICHIGAN TO NORTHERN ILLINOIS EARLY THIS MORNING. THE FRONT WILL CONTINUE TO DROP TO THE SOUTH AND IT SHOULD REACH OUR REGION TONIGHT. SHOWERS AND TSTMS ARE POSSIBLE. WITH THE HEAT AND HUMIDITY, CONDITIONS WILL BE QUITE UNSTABLE AHEAD OF THE FRONT. SPC HAS THE NORTHERN HALF OF OUR FORECAST AREA IN ITS SLIGHT RISK AREA FOR SEVERE WEATHER DURING THE NEXT 24 HOURS. IT SEEMS QUITE REASONABLE AND WE'LL ISSUE A SPECIAL WEATHER STATEMENT REGARDING THE THREAT. WEDNESDAY AND THURSDAY ARE EXPECTED TO BE A BIT COOLER SO THE WARNINGS AND ADVISORIES WILL LIKELY NOT NEED TO BE EXTENDED. THERE'S STILL SOME UNCERTAINTY REGARDING THE LOW OFF THE CAROLINA COAST EARLY THIS MORNING. WE'VE INTRODUCED SLIGHT CHANCE POPS INTO THE FORECASTS FOR WEDNESDAY AND THURSDAY IN THE EVENT THAT THE LOW DOES FOLLOW A NORTH NORTHWEST TRACK. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... WITH THE JET STREAM DROPPING BACK OVER THE REGION, IT APPEARS THAT THE HIGH HEAT AND HUMIDITY ARE NOT EXPECTED TO RETURN AT LEAST THROUGH MONDAY. TEMPERATURES ARE GENERALLY FCST TO STAY BELOW 90 FOR THE HIGHS AND DEWPOINTS GENERALLY REMAIN IN THE 60S. FOLLOWING HPC PROGS WHICH ARE GENERALLY DERIVED FROM THE ECMWF SHOWS HIGH PRESSURE MOVES BY TO THE NORTH OF THE AREA THURS ALLOWING FOR A DRY DAY. ON FRIDAY, ANOTHER COLD FRONT DROPS DOWN FROM THE NW WITH PSBL TSTMS. NEXT WEEKEND LOOKS DRY WITH HIGH PRESSURE MOVING ACROSS THE REGION. ON MONDAY, ANOTHER COLD FRONT APPROACHES FROM THE NW IN THE MORNING AND WILL PROBABLY MOVE THROUGH IN THE AFTN. && .AVIATION... ANOTHER CLEAR CALM NIGHT ACROSS THE FORECAST AREA. SOME LOCATIONS MAY SEE A VISIBILITY RESTRICTION FOR SEVERAL HOURS PRIOR TO AND AROUND DAYBREAK AS INCREASED HUMIDITIES AND LIGHT WINDS PRODUCE HAZE AND FOG, BUT ONLY ONE OR TWO ISOLATED LOCATIONS WILL DROP BELOW MVFR. WEST TO SOUTHWEST WINDS WILL PICK UP A LITTLE THIS MORNING AS A FRONT APPROACHES FROM THE WEST, AND SOME HIGH CLOUDS MAY BEGIN TO SPREAD INTO THE AREA AS WELL. SCATTERED THUNDERSTORMS MAY PRECEDE AND ACCOMPANY THE FRONT LATE TODAY INTO TONIGHT. NORTHERN SECTIONS OF THE FORECAST AREA WILL HAVE THE BEST CHANCE TO SEE ANY THUNDERSTORMS APPROACHING SEVERE LIMITS. && .MARINE... TRANQUIL CONDITIONS ARE EXPECTED TO CONTINUE OVER THE MARINE AREA. A FRONTAL ZONE WILL WEAKEN AS IT MOVES IN THE MID ATLANTIC REGION TONIGHT. COMPUTER MODELS STILL DO NOT AGREE ON THE EVOLUTION OF LOW PRESSURE OFF THE NORTH CAROLINA COAST, SO WILL CONTINUE TO KEEP WINDS AND SEAS BELOW SMALL CRAFT ADVISORY CRITERIA. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...EXCESSIVE HEAT WARNING FOR PAZ067>071 UNTIL 9 PM TUESDAY. ...HEAT ADVISORY FOR PAZ060>062 UNTIL 8 PM TUESDAY. NJ...HEAT ADVISORY FOR NJZ001-007>010-012-013-016-020>023-027 UNTIL 8 PM TUESDAY. ...EXCESSIVE HEAT WARNING FOR NJZ015-017>019 UNTIL 9 PM TUESDAY. DE...EXCESSIVE HEAT WARNING FOR DEZ001 UNTIL 9 PM TUESDAY. ...HEAT ADVISORY FOR DEZ002-003 UNTIL 8 PM TUESDAY. MD...HEAT ADVISORY FOR MDZ008-012-015-019-020 UNTIL 8 PM TUESDAY. MARINE...NONE. && $$ UPDATE...GORSE SHORT TERM...IOVINO LONG TERM...STAUBER AVIATION/MARINE...RPW pa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX 226 PM CDT TUE JUL 18 2006 .SHORT TERM... AN UPPER LEVEL SHORTWAVE IMPULSE WILL CONTINUE TO MOVE WESTWARD ACROSS THE FORECAST AREA TONIGHT. THIS FEATURE SEEMS TO BE INITIALIZED AND HANDLED WELL BY THE RUC AND GFS MODELS. THINK THE BEST CHANCE FOR CONVECTION THIS EVENING INTO TONIGHT WILL SHIFT WESTWARD ALONG WITH THE 700-500 MILLIBAR THETA-E RIDGE AND RELATIVE HUMIDITY AXIS. WE WILL CARRY 10-20 PCT GRIDDED POPS MAINLY WEST OF A TATUM...HOBBS...PECOS...MARFA LINE TONIGHT UNDER PARTLY CLOUDY SKIES. SKIES SHOULD BE MOSTLY CLEAR ACROSS FAR EASTERN AREAS UNDERNEATH INCREASING SUBSIDENCE IN THE WAKE OF THE SHORTWAVE. LOOK FOR ANOTHER WARM NIGHT...WITH LOWS IN THE 60S AND 70S. .LONG TERM... ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH THE WEEK...HOWEVER NEAR TO BELOW NORMAL TEMPERATURES WILL BE POSSIBLE THIS WEEKEND AS A COLD FRONT MOVES INTO THE AREA. THE FORECAST AREA WILL REMAIN ON THE SOUTHERN FRINGE OF A STRONG UPPER LEVEL RIDGE THROUGH FRIDAY...PORTENDING DEEP EASTERLY FLOW OVER THE AREA. EXPECT TEMPERATURES TO BEGIN A SLOW DOWNWARD TREND THROUGH THE WEEK...WITH ONLY ISOLATED POPS EXPECTED OVER THE HIGHER TERRAIN OF WEST TEXAS AND SOUTHEAST NEW MEXICO. THEREAFTER...THE UPPER RIDGE WILL RETROGRADE AND BUILD INTO THE PACIFIC NORTHWEST AS AN UPPER TROUGH BECOMES ESTABLISHED OVER THE EASTERN CONUS. THE LONGITUDINAL FLOW BETWEEN THE RIDGE TO THE WEST AND TROUGH TO THE EAST WILL ALLOW FOR A COLD FRONT TO DROP INTO THE AREA IN THE SATURDAY/SUNDAY TIME FRAME. HAVE GONE WITH A BLEND OF THE GFS AND DGEX FOR THE TIMING OF THE FRONT...AND POPS OVER THE CWA. WENT WITH THE BEST CHANCES SATURDAY NIGHT OVER THE CENTRAL CWA...AND OVER THE HIGHER TERRAIN SUNDAY AS IT APPEARS THE FRONT WILL HAVE A GOOD ENOUGH PUSH TO MAKE IT THROUGH THE CWA ON SUNDAY. RAISED TEMPERATURES A LITTLE ABOVE MEXMOS VALUES SATURDAY AS IT APPEARS THE GFS MAY BE TOO QUICK...THEN SLIGHTLY BELOW ON SUNDAY AS THE FRONT PUSHES THROUGH THE AREA. THE TIMING OF ALL THIS WILL HAVE TO BE REFINED ON SUBSEQUENT SHIFTS...BUT THERE DOES APPEAR TO BE ENOUGH AGREEMENT AMONGST THE ENSEMBLES AND MEDIUM RANGE MODELS TO GO WITH THE HIGHER POPS/COOLER TEMPERATURES. DISAGREEMENT REIGNS THEREAFTER AS THE GFS KEEPS THE FORECAST AREA BETWEEN THE WEST COAST RIDGE/EAST COAST TROUGH...WHILE THE ECMWF BEGINS TO EXPAND THE RIDGE BACK OVER THE CWA. CONSIDERING HOW PERSISTENT THE UPPER LEVEL RIDGE HAS BEEN SO FAR...WENT WITH THE ECMWF AND DRIED THE FORECAST OUT AND RAISED TEMPERATURES FOR EARLY NEXT WEEK. IF FUTURE MODEL RUNS INDICATE MORE OF A GFS SOLUTION... POPS WILL HAVE TO BE ADDED AND TEMPERATURES LOWERED SOME. && .PRELIMINARY POINT TEMPS/POPS... BIG SPRING TX 75 100 74 99 / 0 0 0 0 CARLSBAD NM 71 100 72 101 / 20 10 10 10 DRYDEN TX 76 98 76 98 / 0 10 10 10 FORT STOCKTON TX 74 98 74 98 / 10 10 10 10 GUADALUPE PASS TX 69 92 72 96 / 20 10 10 10 HOBBS NM 68 101 70 100 / 10 10 10 10 MARFA TX 59 91 58 91 / 20 10 10 10 MIDLAND INTL AIRPORT TX 76 100 75 101 / 0 10 10 10 ODESSA TX 77 101 78 101 / 10 10 10 10 WINK TX 77 106 77 107 / 10 10 10 10 && .MAF WATCHES/WARNINGS/ADVISORIES... NM...NONE. TX...NONE. && $$ 21/67 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SALT LAKE CITY UT 1041 AM MDT TUE JUL 18 2006 .SYNOPSIS...A WARM AIRMASS WITH INCREASING MOISTURE WILL REMAIN OVER THE AREA THROUGH THURSDAY AS HIGH PRESSURE PERSISTS OVER THE INTERMOUNTAIN REGION. && .DISCUSSION...PRECIPITABLE WATER VALUES ARE 103 PERCENT OF NORMAL THIS MORNING ON THE KSLC SOUNDING. RIDGE HAS SLID EAST AND ALLOWED MOISTURE TO CREEP UP FROM THE SOUTH. NAM AND GFS BRING 8+ G/KG AIRMASS OVER SOUTHERN UTAH TODAY WITH NAM...GFS...AND RUC MODEL RUNS ALL HAVING PRECIPITABLE WATER VALUES EXCEEDING 1 INCH ALONG THE SOUTHERN BORDER OF THE AREA. WITH THE MOISTURE IN PLACE...LIGHT STORM MOTION FLOW IN BOTH MODELS SUGGEST FLOOD ISSUES ARE LIKELY TO DEVELOP THIS AFTERNOON. SOUTHEAST UTAH MAY NEED TO BE INCLUDED IN THE FLASH FLOOD WATCH LATER ON...BUT DELAYING UNTIL DEVELOPMENT IS SEEN OVER THE AREA. SOLAR INSOLATION IS DEFINITELY BECOMING A MAXIMUM OVER THE AREA. GOES-WEST RSO OPERATIONS HAVE BEEN REQUESTED DUE TO FLASH FLOOD POTENTIAL FOR SOUTHERN UTAH. OVER NORTHERN UTAH...PRECIPITABLE WATER VALUES HAVE INCREASED BUT MODEL SOUNDING SUGGEST THAT THE THUNDERSTORMS WILL BE HIGH-BASED AND COULD HAVE HIGH WIND GUST POTENTIAL. ISOLATED STRONG STORMS COULD BE EXPECTED DUE TO THIS IDEA WITH PRIMARY THREAT DUE TO WIND. FLOOD ISSUES SHIFT NORTH ON WEDNESDAY AS THE MOISTURE SHIFT NORTHWARD. GFS AND NAM SHIFT MOIST AIRMASS NORTH WITH 6 G/KG MIXING RATIO AIR AT 700 MB AND PRECIPITABLE WATER NEAR EXCEEDING 1 INCH AT 00Z. GFS SEEMS TO BE MORE REALISTIC WITH THE AIRMASS THOUGH GFS IS A BIT MORE AGGRESSIVE WITH ITS MOVEMENT. SOME DRYING DOES OCCUR AS IT SHIFTS NORTH. FLOW REMAINS LIGHT AGAIN. LONGER RANGE MODELS ARE STILL DROPPING A CANADIAN TROUGH EAST OF THE AREA. COOLING CAN BE EXPECTED OVER THE AREA. GFS IS NOT QUITE AS AGGRESSIVE WITH THE SOLUTIONS AS IT WAS YESTERDAY AND THE LATEST RUN SEEMS TO BE CLOSE TO 00Z AND 06Z SOLUTIONS. EXPECT A COOLING TREND TO LINGER INTO THE WEEKEND OVER THE NORTH WITH THE AREA WARMING BACK UP FOR THE END OF THE WEEKEND. && .AVIATION...LOCAL DRAINAGE WINDS WILL GIVE WAY TO NORMAL LAKE BREEZE BY EARLY AFTERNOON AT KSLC. CLOUDS WILL BUILD UP THIS AFTERNOON WITH AN INCREASING THREAT FOR THUNDERSTORMS NEAR THE TERMINAL IN THE 21Z TO 03Z TIME FRAME. THUNDERSTORMS WILL MOST LIKELY BE HIGH BASED WITH LITTLE PRECIPITATION...GUSTY ERRATIC WINDS...AND LIGHTNING. && .FIRE WEATHER...DEEPER MOISTURE WILL BUILD INTO SOUTHERN UTAH THIS AFTERNOON AS AN EASTERLY WAVE MOVES THROUGH THE AREA. AHEAD OF THIS WAVE MID LEVEL MOISTURE WILL SPREAD NORTH WITH ITS TERMINUS AT A MID LEVEL DEFORMATION ZONE SITUATED ACROSS NORTHERN UTAH. THE AIRMASS ACROSS NORTHERN UTAH WILL DESTABILIZE THIS AFTERNOON AND WITH MID LEVEL MOISTURE IN PLACE WE WILL SEE THE THREAT OF DRY LIGHTNING AND STRONG GUSTY WINDS. WILL BE UPGRADING THE FIRE WEATHER WATCH TO A RED FLAG WARNING FOR NW UTAH THIS MORNING. THE COVERAGE OF THE CONVECTION SHOULD BE GREATER ACROSS CENTRAL AND SOUTHERN UTAH WHERE DEEPER MOISTURE WILL BE IN PLACE. ALTHOUGH DEEPER MOISTURE IS SPREADING INTO THIS AREA BELIEVE THAT WITH A SUBSTANTIAL DRY LAYER NEAR THE SURFACE THE INITIAL CONVECTION WILL LARGELY BE OF THE DRY VARIETY AND THEREFORE THE RED FLAG WARNING CONTINUES FOR MUCH OF CENTRAL AND EASTERN UTAH. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...RED FLAG WARNING UNTIL 10 PM TUESDAY FOR UTZ427-431>434-436- 438-441-445. FLASH FLOOD WATCH UNTIL 9 PM TUESDAY FOR UTZ016-UTZ017-UTZ019- UTZ020. FIRE WEATHER WATCH UNTIL 10 PM TUESDAY FOR UTZ420>426. WY...NONE. && $$ PUBLIC...HALL AVIATION...YOUNG FIRE WEATHER...GRAHAM ut