AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE CARIBOU ME 1104 PM EDT SUN JUL 16 2006 .SYNOPSIS...A SURFACE TROUGH WILL APPROACH THE STATE OVERNIGHT THEN CROSS THE REGION MONDAY. A STRONGER COLD FRONT WILL CROSS THE STATE ON TUESDAY FOLLOWED BY COOLER AND DRIER AIR FOR WEDNESDAY INTO THURSDAY. ANOTHER FRONTAL SYSTEM IS EXPECTED TO MOVE ACROSS THE REGION ON FRIDAY. && .SHORT TERM /OVERNIGHT/... HAVE ONLY MADE MINOR ADJUSTMENTS TO INCREASE PRECIPITATION CHANCES/CLOUD COVER AND TO SLIGHTLY LOWER TEMPERATURES ACROSS SOME NORTHERN/CENTRAL AREAS. EXPECT AN AREA OF SHOWERS AND THUNDERSTORMS TO MOVE EAST ACROSS MOSTLY NORTHERN/CENTRAL AREAS OVERNIGHT. ACROSS DOWNEAST AREAS...HAVE INCREASED THE EXTENT OF FOG AND INCLUDED LOCALLY DENSE WORDING WHERE THE MARINE STRATUS/FOG IS MOVING INLAND. && .PREVIOUS DISCUSSION... .SHORT TERM /TONIGHT THROUGH TUESDAY/... A NARROW LINE OF SHOWERS AND THUNDERSTORMS DEVELOPED LATE THIS AFTERNOON ACROSS THE CENTRAL AND INTERIOR DOWNEAST ZONES ALONG TROUGH AXIS THAT STRETCHES FROM NORTHEAST NEW BRUNSWICK SOUTHWEST INTO CENTRAL AND INTERIOR DOWNEAST MAINE. RUC MODEL SEEMS TO HAVE HANDLED THIS FEATURE QUITE WELL. EXPECT THE CHANCE OF A SHOWER OR TSTM WITH THIS FEATURE THROUGH EARLY EVENING ESP EASTERN ZONES. EXPECT A BRIEF BREAK EARLY TONIGHT...HOWEVER ANOTHER SHORT WAVE APPROACHING FROM THE WEST LATE TONIGHT WILL BRING ANOTHER ROUND OF SHOWERS AND TSTMS. IT APPEARS THE BEST CHANCES WITH THIS FEATURE WILL BE ACROSS THE NORTHERN ZONES WHERE WENT WITH LIKELY POPS OVERNIGHT. WENT WITH CHANCE FURTHER SOUTH ACROSS CENTRAL AND INTERIOR DOWNEAST MAINE. THIS FEATURE WILL MOVE OFF TO THE EAST EARLY MONDAY. WILL CONTINUE TO CARRY A CHANCE OF A SHOWER OR TSTM THROUGH THE DAY HOWEVER. A COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE MONDAY NIGHT AND THEN MOVE ACROSS THE REGION ON TUESDAY. KEPT THEME OF LIKELY POPS FROM PREVIOUS FORECAST AS THE FRONT CROSSES THE REGION TUE. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... ONCE AGAIN USED HPC GRIDS PRETTY MUCH AS IS DUE TO CONVECTION FIRING ACROSS CNTL & ERN AREAS. LOOKS DRY & A BIT COOLER FOR WEDNESDAY INTO THURSDAY AS HIGH PRES BUILDS ACROSS NERN U.S. TEMPERATURES WERE RAISED A FEW DEGS ESP ACROSS CNTL & DOWNEAST ZONES W/MORE SUN & SWLY WIND FLOW. DROPPED BACK DEWPOINTS A TAD TO LINE UP W/OUR NEIGHBOR TO THE S. THE NEXT SYSTEM IS PROGGED TO MOVE INTO THE REGION LATE THURSDAY NIGHT INTO FRIDAY. LATEST GFS DEVELOPING ON THE FRONTAL BOUNDARY & MOVES IT NRN & NWRN MAINE ON FRIDAY DRAGGING THE ASSOCD COLD FRONT W/IT. DECENT LLVL & MID LVL SPD MAX ALONG & AHEAD OF THE FRONT. KEPT MENTION OF SHOWERS & TSTMS IN THERE FOR FRIDAY. GFS REALLY CRANKS OUT BUNCH OF QPF WHILE THE CANADIAN GEM NOT AS MOIST & KEEPS SFC LOW FURTHER N INTO QUEBEC LINING CLOSE THE 00Z ECMWF. INCREASED POPS ABOUT 10% W/CHC THROUGH THE ENTIRE CWA. KEPT SMALL POPS IN THERE FOR EARLY SATURDAY W/UPPER TROF MOVG THROUGH THE CWA. TEMPERATURES LOOK TO COOL DOWN AGAIN AS LLVL & MID LVL TEMPERATURES FALL BACK. FOLLOWED THIS WILL USING HPC TEMPERATURES FOR SATURDAY INTO SUNDAY. USED THE 06Z GFS WINDS & THEN MODIFIED THEM ESP AT NIGHT TO MATCH BETTER. GFS LOOKS A BIT OVERDONE W/INCREASING THE GRADIENT AHEAD OF APCHG COLD FRONT. BACKED OFF ON WINDS A BIT LEANING MORE W/10- 20 MPH ON FRIDAY. && .AVIATION... VFR CONDITIONS TO START THE EVENING W/SOME TSRA W/HVY RAFL & GUSTY WINDS. LOOKING FOR CONDITIONS TO DROP TO MVFR CATEGORY ACROSS THE NRN TAF SITES BY 03Z & PRETTY MUCH STAYING THERE THROUGH MONDAY MORNING. CIGS GOING DOWN TO 2K FT W/VSBYS DOWN TO 2-3 SM. TOWARD KBGR...LOOKING FOR THINGS TO GO RIGHT TO IFR BY 05 OR 06Z W/VSBYS LOWERING BLO 1SM & CIGS DROPPING BLO 1K FT IN FOG. A SLOW IMPROVEMENT FOR KBGR W/WEAK WIND FIELDS ALOFT. && .MARINE... SHORT TERM: NO HEADLINES ATTM. SEAS COULD RUN NEAR SCA CRITERIA ON TUE AHEAD OF APCHG COLD FRONT. LONG TERM: BACKED WINDS OFF FROM 06Z GFS & LEANED W/SOLID 20 KTS AHEAD OF APCHG COLD FRONT. WARM SWLY FLOW OVER RELATIVELY COOL WATERS SHOULD HELP TO KEEP WINDS FROM MIXING DOWN TO BLYR. FOR WAVE HEIGHTS...WNA GUIDANCE HAS BEEN RUNNING HIGH LATELY. THEREFORE...HAVE SEAS TOPPING OFF AT 4 FT. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ UPDATE...NORCROSS SHORT TERM/MARINE...DUDA LONG TERM/MARINE...HEWITT AVIATION...NORTON me AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CARIBOU ME 401 PM EDT SUN JUL 16 2006 .SYNOPSIS...A SURFACE TROUGH WILL APPROACH THE STATE TONIGHT AND CROSS THE REGION ON MONDAY. A STRONGER COLD FRONT WILL CROSS THE STATE ON TUESDAY FOLLOWED BY COOLER AND DRIER AIR FOR WEDNESDAY INTO THURSDAY. ANOTHER FRONTAL SYSTEM IS EXPECTED TO MOVE ACROSS THE REGION ON FRIDAY. && .SHORT TERM /TONIGHT THROUGH TUESDAY/... A NARROW LINE OF SHOWERS AND THUNDERSTORMS DEVELOPED LATE THIS AFTERNOON ACROSS THE CENTRAL AND INTERIOR DOWNEAST ZONES ALONG TROUGH AXIS THAT STRETCHES FROM NORTHEAST NEW BRUNSWICK SOUTHWEST INTO CENTRAL AND INTERIOR DOWNEAST MAINE. RUC MODEL SEEMS TO HAVE HANDLED THIS FEATURE QUITE WELL. EXPECT THE CHANCE OF A SHOWER OR TSTM WITH THIS FEATURE THROUGH EARLY EVENING ESP EASTERN ZONES. EXPECT A BRIEF BREAK EARLY TONIGHT...HOWEVER ANOTHER SHORT WAVE APPROACHING FROM THE WEST LATE TONIGHT WILL BRING ANOTHER ROUND OF SHOWERS AND TSTMS. IT APPEARS THE BEST CHANCES WITH THIS FEATURE WILL BE ACROSS THE NORTHERN ZONES WHERE WENT WITH LIKELY POPS OVERNIGHT. WENT WITH CHANCE FURTHER SOUTH ACROSS CENTRAL AND INTERIOR DOWNEAST MAINE. THIS FEATURE WILL MOVE OFF TO THE EAST EARLY MONDAY. WILL CONTINUE TO CARRY A CHANCE OF A SHOWER OR TSTM THROUGH THE DAY HOWEVER. A COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE MONDAY NIGHT AND THEN MOVE ACROSS THE REGION ON TUESDAY. KEPT THEME OF LIKELY POPS FROM PREVIOUS FORECAST AS THE FRONT CROSSES THE REGION TUE. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... ONCE AGAIN USED HPC GRIDS PRETTY MUCH AS IS DUE TO CONVECTION FIRING ACROSS CNTL & ERN AREAS. LOOKS DRY & A BIT COOLER FOR WEDNESDAY INTO THURSDAY AS HIGH PRES BUILDS ACROSS NERN U.S. TEMPERATURES WERE RAISED A FEW DEGS ESP ACROSS CNTL & DOWNEAST ZONES W/MORE SUN & SWLY WIND FLOW. DROPPED BACK DEWPOINTS A TAD TO LINE UP W/OUR NEIGHBOR TO THE S. THE NEXT SYSTEM IS PROGGED TO MOVE INTO THE REGION LATE THURSDAY NIGHT INTO FRIDAY. LATEST GFS DEVELOPING ON THE FRONTAL BOUNDARY & MOVES IT NRN & NWRN MAINE ON FRIDAY DRAGGING THE ASSOCD COLD FRONT W/IT. DECENT LLVL & MID LVL SPD MAX ALONG & AHEAD OF THE FRONT. KEPT MENTION OF SHOWERS & TSTMS IN THERE FOR FRIDAY. GFS REALLY CRANKS OUT BUNCH OF QPF WHILE THE CANADIAN GEM NOT AS MOIST & KEEPS SFC LOW FURTHER N INTO QUEBEC LINING CLOSE THE 00Z ECMWF. INCREASED POPS ABOUT 10% W/CHC THROUGH THE ENTIRE CWA. KEPT SMALL POPS IN THERE FOR EARLY SATURDAY W/UPPER TROF MOVG THROUGH THE CWA. TEMPERATURES LOOK TO COOL DOWN AGAIN AS LLVL & MID LVL TEMPERATURES FALL BACK. FOLLOWED THIS WILL USING HPC TEMPERATURES FOR SATURDAY INTO SUNDAY. USED THE 06Z GFS WINDS & THEN MODIFIED THEM ESP AT NIGHT TO MATCH BETTER. GFS LOOKS A BIT OVERDONE W/INCREASING THE GRADIENT AHEAD OF APCHG COLD FRONT. BACKED OFF ON WINDS A BIT LEANING MORE W/10- 20 MPH ON FRIDAY. && .AVIATION... VFR CONDITIONS TO START THE EVENING W/SOME TSRA W/HVY RAFL & GUSTY WINDS. LOOKING FOR CONDITIONS TO DROP TO MVFR CATEGORY ACROSS THE NRN TAF SITES BY 03Z & PRETTY MUCH STAYING THERE THROUGH MONDAY MORNING. CIGS GOING DOWN TO 2K FT W/VSBYS DOWN TO 2-3 SM. TOWARD KBGR...LOOKING FOR THINGS TO GO RIGHT TO IFR BY 05 OR 06Z W/VSBYS LOWERING BLO 1SM & CIGS DROPPING BLO 1K FT IN FOG. A SLOW IMPROVEMENT FOR KBGR W/WEAK WIND FIELDS ALOFT. && .MARINE... SHORT TERM: NO HEADLINES ATTM. SEAS COULD RUN NEAR SCA CRITERIA ON TUE AHEAD OF APCHG COLD FRONT. LONG TERM: BACKED WINDS OFF FROM 06Z GFS & LEANED W/SOLID 20 KTS AHEAD OF APCHG COLD FRONT. WARM SWLY FLOW OVER RELATIVELY COOL WATERS SHOULD HELP TO KEEP WINDS FROM MIXING DOWN TO BLYR. FOR WAVE HEIGHTS...WNA GUIDANCE HAS BEEN RUNNING HIGH LATELY. THEREFORE...HAVE SEAS TOPPING OFF AT 4 FT. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ SHORT TERM/MARINE...DUDA LONG TERM/MARINE...HEWITT AVIATION...NORTON me AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 943 PM EDT SUN JUL 16 2006 .UPDATE... CONCERNS DEAL WITH CONVECTION POTENTIAL AND POSSIBILITY OF SVR STORMS. SEVERE THUNDERSTORMS WHICH FORMED IN VERY UNSTABLE BOUNDARY LYR OVER THE MN ARROWHEAD DISSIPATED QUICKLY OVER THE COOLER STABLE WATERS OF WESTERN LAKE SUPERIOR THIS EVENING. REMNANTS OF THESE STORMS HAVE MOVED INTO HOUGHTON AND NRN ONTONAGON COUNTIES PRODUCING LIGHT RAIN. ELSEWHERE...UPPER MICHIGAN IS FAIRLY WELL CAPPED AND THIS IS EVIDENT ON 00Z AREAS SNDGS...KGRB SNDG SHOWS AT 23C BULGE OF WARM AIR AT AROUND 825 MB WITH A CONVECTIVE TEMP OF 107F AND SBCIN OF 228 J/KG. ALTHOUGH SFC-BASED CONVECTION IS BEING HELD IN CHECK EARLY THIS EVENING...CAP COULD BE BROKEN LATER TONIGHT AS SHORTWAVES APPROACH FROM SD AND SRN MANITOBA AND LLJ STRENGTHENS TO 35-40KT IN RIGHT ENTRANCE REGION OF ASSOC 100-110 KT 3H JET MAX MOVING THROUGH WRN ONTARIO. PLENTY OF DEEP LAYER SHEAR 35-50KT FM 0-6KM WITH MUCAPES OF 1500-2500 J/KG WOULD BE SUFFICIENT FOR ISOLD SUPERCELLS WITH LARGE HAIL AND DAMAGING WINDS POSSIBLE. UPDATED DAY1 CONVECTIVE OUTLOOK STILL HAS ENTIRE FCST AREA IN SLIGHT RISK WHICH LOOKS JUSTIFIED. SO DO NOT ANTICIPATE ANY MAJOR CHANGES TO FCST ON UPDATE. && .PREV DISCUSSION... MAIN FCST CONCERNS ARE SHRA/TSRA POTENTIAL TONIGHT/MON AND POSSIBILITY OF SVR STORMS. WILL THERE BE A REPEAT PERFORMANCE TONIGHT OF WHAT HAPPENED LAST NIGHT? WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW MID/UPPER LEVEL RIDGE DOMINATING THE SRN 2/3RDS OF THE CONUS. UPSTREAM...A SHORTWAVE IS EVIDENT OVER SD. NOTHING SIGNIFICANT IN THE WAY OF TSRA ARE OCCURRING IN THE VCNTY OF WAVE RIGHT NOW...BUT VIS SATELLITE IMAGERY SHOWS CONTINUED EXPANSION OF ACCAS ACROSS THE ERN DAKOTAS INTO NRN MN (AN IMPORTANT SIGN FOR CONVECTIVE POTENTIAL HERE TONIGHT). FARTHER UPSTREAM...A MORE SIGNIFICANT SHORTWAVE IS HEADING E ACROSS SASKATCHEWAN. CLOSER TO HOME...THIN BAND OF TSRA THAT PESISTED INTO THE AFTN FROM NEAR THE KEWEENAW E ACROSS FAR SRN LAKE SUPERIOR WAS ALIGNED ALONG 850MB TROF WHERE WRLY WINDS WERE CONVERGING. THIS ACTIVITY HAS FINALLY DISSIPATED...BUT NEW DEVELOPMENT IS NOW OCCURRING OVER NRN LAKE MI WITHIN REMNANT OF LAST NIGHTS LOW-LEVEL JET. 12Z SOUNDINGS FROM KGRB TO THE DAKOTAS SHOW VERY STEEP... GENERALLY DRY ADIABATIC...LAPSE RATES THRU 500MB. SD SHORTWAVE AHEAD OF THE STRONGER SHORTWAVE NOW IN SASKATCHEWAN WILL PLAY A ROLE IN CONVECTIVE POTENTIAL TONIGHT. AS THE 2 SHORTWAVES HEAD E TONIGHT...850MB JET WILL AGAIN CRANK UP TO 40-50KT INTO UPPER MI ALONG WITH INCREASING THETA-E. EXAMINATION OF GFS/NAM FCST SOUNDINGS SHOW MORE CAPPING TONIGHT THAN LAST NIGHT WHEN LIFTING PARCELS FROM A VARIETY OF LOW AND MIDLEVELS. CAPE FOR PARCELS LIFTED FROM 850MB RANGE ANYWHERE FROM 1000-2500J/KG...BUT CIN IS HIGH...ESPECIALLY ON GFS WHICH HAS VALUES GENERALLY AOA 100J/KG. HOWEVER...WITH INCREASING LOW-LEVEL JET AND APPROACH OF SD SHORTWAVE JUST AHEAD OF STRONGER SHORTWAVE HEADING ACROSS SRN CANADA...WILL ASSUME CAP WILL BE BROKEN SOMEWHERE IN THE LOW-MID LEVELS. EXPANSION OF ACCAS UPSTREAM (JUST AS OCCURRED YESTERDAY AFTN) IS ALSO VERY SUGGESTIVE THAT CONVECTION WILL FIRE DESPITE CIN INDICATED ON FCST SOUNDINGS. EXTREMELY STEEP NEARLY DRY ADIABATIC MIDLEVEL (700-500MB) LAPSE RATES OF 8-9C/KM WILL ALSO AID CONVECTIVE DEVELOPMENT. AS FOR SVR POTENTIAL...DEEP LAYER SHEAR WILL BE SUFFICIENT FOR SOME STORM ORGANIZATION...SO TONIGHT MAY END UP BEING VERY SIMILAR TO LAST NIGHT WITH SOME STORMS BECOMING SVR (LARGE HAIL/DAMAGING WINDS). MAY BE ANOTHER NIGHT WITH TREMENDOUS LIGHTNING ACTIVITY AS WELL. INITIAL STORMS MAY FIRE EARLY THIS EVENING AS WEAK SFC BOUNDARY THAT IS DRIFTING INTO UPPER MI LIFTS BACK N. OTHERWISE...BELIEVE BETTER CHANCE WILL OCCUR LATE EVENING AND OVERNIGHT IN ASSOCIATION WITH LOW-LEVEL JET. IT WILL BE ANOTHER WARM NIGHT AS WINDS REMAIN UP WITH SFC DWPTS IN THE MID 60S TO LOW 70S... BUT PROBABLY NOT QUITE AS WARM AS LAST NIGHT. COLD FRONT ASSOCIATED WITH SHORTWAVE TRACKING ACROSS SRN CANADA WILL REACH THE WRN FCST AREA MON MORNING AND EXIT THE ERN FCST AREA MON AFTN. WILL CARRY CHC POPS FOR SHRA/TSRA UNTIL FROPA. WILL CUT HIGHS BACK CLOSER TO GFS MOS GUIDANCE...ESPECIALLY OVER THE W... GIVEN FAIRLY EARLY PASSAGE OF FRONT AND DECENT CAA. COOLER/MORE COMFORTABLE AIRMASS WILL SETTLE OVER THE FCST AREA MON NIGHT AS SFC HIGH BUILDS INTO THE WRN LAKES. MINS IN THE LOW/MID 50S IN MOST PLACES TUE NIGHT PER GFS MOS GUIDANCE LOOK REASONABLE. MIXING UPWARDS OF 800-750MB YIELDS HIGHS TUE IN THE LOW-MID 80S INLAND. WILL BE COOLER NEAR THE GREAT LAKES AS LAKE BREEZES SHOULD RULE THE DAY. WED THRU SUN...ECWMF/UKMET/CANADIAN/GFS ARE IN REASONABLE AGREEMENT FOR THIS PERIOD AND ARE PROVIDING INCREASING CONFIDENCE FOR THE REESTABLISHMENT OF A TROF OVER SE CANADA/GREAT LAKES/NEW ENGLAND LATE THIS WEEK INTO NEXT WEEK AS HEIGHTS RISE OVER WRN NAMERICA. SHORTWAVE THAT BEGINS THIS TREND TOWARD TROFFING PASSES ACROSS THE UPPER LAKES/ONTARIO THU. MODELS STILL HAVE TIMING DIFFERENCES WITH THIS SHORTWAVE...BUT IN GENERAL THE BULK OF RECENT MODEL RUNS SHOW A SLIGHTLY FASTER PROGRESSION THAN PREVIOUS FCST INDICATES. WILL THUS BRING FRONT THRU THE W EARLY IN THE MORNING AND E EARLY IN THE AFTN. AS FOR PCPN...WILL CONTINUE TO CARRY SHRA/TSRA CHC ON WED AHEAD FRONT IN WAA PATTERN AND THEN END CHC FROM W TO E WITH FROPA ON THU. WITH DEVELOPMENT OF TROF OVER SE CANADA...FRONT SHOULD MOVE WELL S OF UPPER MI. SO...EXPECT COOLER...MORE SEASONABLE SUMMER WEATHER BEHIND THIS SYSTEM FRI-SUN. WILL MAINTAIN DRY FCST FOR FRI/SAT WITH SFC HIGH PRES PASSING ACROSS THE GREAT LAKES. THERE IS ACTUALLY SOME AGREEMENT WITH 00Z/06Z GFS AND 00Z ECWMF FOR ANOTHER SHORTWAVE TO DROP SE TOWARD THE GREAT LAKES LATE SAT/SUN. WILL INCLUDE A CHC OF SHRA/TSRA ON SUN FOR THIS SYSTEM. THIS CHC MAY NEED TO BE BUMPED UP TO SAT BASED ON FASTER TIMING SEEN IN 12Z GFS/ECMWF. && .MQT...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ VOSS (UPDATE) ROLFSON (PREV DISCUSSION) mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 419 PM EDT SUN JUL 16 2006 .DISCUSSION... MAIN FCST CONCERNS ARE SHRA/TSRA POTENTIAL TONIGHT/MON AND POSSIBILITY OF SVR STORMS. WILL THERE BE A REPEAT PERFORMANCE TONIGHT OF WHAT HAPPENED LAST NIGHT? WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW MID/UPPER LEVEL RIDGE DOMINATING THE SRN 2/3RDS OF THE CONUS. UPSTREAM...A SHORTWAVE IS EVIDENT OVER SD. NOTHING SIGNIFICANT IN THE WAY OF TSRA ARE OCCURRING IN THE VCNTY OF WAVE RIGHT NOW...BUT VIS SATELLITE IMAGERY SHOWS CONTINUED EXPANSION OF ACCAS ACROSS THE ERN DAKOTAS INTO NRN MN (AN IMPORTANT SIGN FOR CONVECTIVE POTENTIAL HERE TONIGHT). FARTHER UPSTREAM...A MORE SIGNIFICANT SHORTWAVE IS HEADING E ACROSS SASKATCHEWAN. CLOSER TO HOME...THIN BAND OF TSRA THAT PESISTED INTO THE AFTN FROM NEAR THE KEWEENAW E ACROSS FAR SRN LAKE SUPERIOR WAS ALIGNED ALONG 850MB TROF WHERE WRLY WINDS WERE CONVERGING. THIS ACTIVITY HAS FINALLY DISSIPATED...BUT NEW DEVELOPMENT IS NOW OCCURRING OVER NRN LAKE MI WITHIN REMNANT OF LAST NIGHTS LOW-LEVEL JET. 12Z SOUNDINGS FROM KGRB TO THE DAKOTAS SHOW VERY STEEP... GENERALLY DRY ADIABATIC...LAPSE RATES THRU 500MB. SD SHORTWAVE AHEAD OF THE STRONGER SHORTWAVE NOW IN SASKATCHEWAN WILL PLAY A ROLE IN CONVECTIVE POTENTIAL TONIGHT. AS THE 2 SHORTWAVES HEAD E TONIGHT...850MB JET WILL AGAIN CRANK UP TO 40-50KT INTO UPPER MI ALONG WITH INCREASING THETA-E. EXAMINATION OF GFS/NAM FCST SOUNDINGS SHOW MORE CAPPING TONIGHT THAN LAST NIGHT WHEN LIFTING PARCELS FROM A VARIETY OF LOW AND MIDLEVELS. CAPE FOR PARCELS LIFTED FROM 850MB RANGE ANYWHERE FROM 1000-2500J/KG...BUT CIN IS HIGH...ESPECIALLY ON GFS WHICH HAS VALUES GENERALLY AOA 100J/KG. HOWEVER...WITH INCREASING LOW-LEVEL JET AND APPROACH OF SD SHORTWAVE JUST AHEAD OF STRONGER SHORTWAVE HEADING ACROSS SRN CANADA...WILL ASSUME CAP WILL BE BROKEN SOMEWHERE IN THE LOW-MID LEVELS. EXPANSION OF ACCAS UPSTREAM (JUST AS OCCURRED YESTERDAY AFTN) IS ALSO VERY SUGGESTIVE THAT CONVECTION WILL FIRE DESPITE CIN INDICATED ON FCST SOUNDINGS. EXTREMELY STEEP NEARLY DRY ADIABATIC MIDLEVEL (700-500MB) LAPSE RATES OF 8-9C/KM WILL ALSO AID CONVECTIVE DEVELOPMENT. AS FOR SVR POTENTIAL...DEEP LAYER SHEAR WILL BE SUFFICIENT FOR SOME STORM ORGANIZATION...SO TONIGHT MAY END UP BEING VERY SIMILAR TO LAST NIGHT WITH SOME STORMS BECOMING SVR (LARGE HAIL/DAMAGING WINDS). MAY BE ANOTHER NIGHT WITH TREMENDOUS LIGHTNING ACTIVITY AS WELL. INITIAL STORMS MAY FIRE EARLY THIS EVENING AS WEAK SFC BOUNDARY THAT IS DRIFTING INTO UPPER MI LIFTS BACK N. OTHERWISE...BELIEVE BETTER CHANCE WILL OCCUR LATE EVENING AND OVERNIGHT IN ASSOCIATION WITH LOW-LEVEL JET. IT WILL BE ANOTHER WARM NIGHT AS WINDS REMAIN UP WITH SFC DWPTS IN THE MID 60S TO LOW 70S... BUT PROBABLY NOT QUITE AS WARM AS LAST NIGHT. COLD FRONT ASSOCIATED WITH SHORTWAVE TRACKING ACROSS SRN CANADA WILL REACH THE WRN FCST AREA MON MORNING AND EXIT THE ERN FCST AREA MON AFTN. WILL CARRY CHC POPS FOR SHRA/TSRA UNTIL FROPA. WILL CUT HIGHS BACK CLOSER TO GFS MOS GUIDANCE...ESPECIALLY OVER THE W... GIVEN FAIRLY EARLY PASSAGE OF FRONT AND DECENT CAA. COOLER/MORE COMFORTABLE AIRMASS WILL SETTLE OVER THE FCST AREA MON NIGHT AS SFC HIGH BUILDS INTO THE WRN LAKES. MINS IN THE LOW/MID 50S IN MOST PLACES TUE NIGHT PER GFS MOS GUIDANCE LOOK REASONABLE. MIXING UPWARDS OF 800-750MB YIELDS HIGHS TUE IN THE LOW-MID 80S INLAND. WILL BE COOLER NEAR THE GREAT LAKES AS LAKE BREEZES SHOULD RULE THE DAY. WED THRU SUN...ECWMF/UKMET/CANADIAN/GFS ARE IN REASONABLE AGREEMENT FOR THIS PERIOD AND ARE PROVIDING INCREASING CONFIDENCE FOR THE REESTABLISHMENT OF A TROF OVER SE CANADA/GREAT LAKES/NEW ENGLAND LATE THIS WEEK INTO NEXT WEEK AS HEIGHTS RISE OVER WRN NAMERICA. SHORTWAVE THAT BEGINS THIS TREND TOWARD TROFFING PASSES ACROSS THE UPPER LAKES/ONTARIO THU. MODELS STILL HAVE TIMING DIFFERENCES WITH THIS SHORTWAVE...BUT IN GENERAL THE BULK OF RECENT MODEL RUNS SHOW A SLIGHTLY FASTER PROGRESSION THAN PREVIOUS FCST INDICATES. WILL THUS BRING FRONT THRU THE W EARLY IN THE MORNING AND E EARLY IN THE AFTN. AS FOR PCPN...WILL CONTINUE TO CARRY SHRA/TSRA CHC ON WED AHEAD FRONT IN WAA PATTERN AND THEN END CHC FROM W TO E WITH FROPA ON THU. WITH DEVELOPMENT OF TROF OVER SE CANADA...FRONT SHOULD MOVE WELL S OF UPPER MI. SO...EXPECT COOLER...MORE SEASONABLE SUMMER WEATHER BEHIND THIS SYSTEM FRI-SUN. WILL MAINTAIN DRY FCST FOR FRI/SAT WITH SFC HIGH PRES PASSING ACROSS THE GREAT LAKES. THERE IS ACTUALLY SOME AGREEMENT WITH 00Z/06Z GFS AND 00Z ECWMF FOR ANOTHER SHORTWAVE TO DROP SE TOWARD THE GREAT LAKES LATE SAT/SUN. WILL INCLUDE A CHC OF SHRA/TSRA ON SUN FOR THIS SYSTEM. THIS CHC MAY NEED TO BE BUMPED UP TO SAT BASED ON FASTER TIMING SEEN IN 12Z GFS/ECMWF. && .MQT...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ ROLFSON mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 100 PM EDT SUN JUL 16 2006 .AVIATION AND UPDATE... CLOUDS AND SHOWERS ASSOCIATED WITH THEM...ESPECIALLY ACROSS THE NORTH SECTIONS OF THE CWA...HAVE DISSIPATED AS WARMING TEMPS ALOFT AND WEAKENING LOW LEVEL JET UPSTREAM SHOULD KEEP THE REST OF THE AFTERNOON QUIET. TEMPERATURES CONTINUE TO BE THE MAIN CONCERN AS WE ARE NOW UNDER THE SUNSHINE YET ADDITIONAL AC IS ATTEMPTING TO FORM ACROSS CENTRAL LOWER MICHIGAN. WHERE WE HAVE HAD THE MOST SUNSHINE...SOUTH OF M59...TEMPERATURES HAVE RESPONDED NICELY WITH LOWER 90S AS OF NOON AND DEWPOINTS HAVE MIXED OUT INTO THE LOWER AND MIDDLE 60S. HERE VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD WITH WINDS BACKING AROUND TO A SOUTHWEST WIND FLOW THIS AFTERNOON. AS CONVECTION DEVELOPS UPSTREAM...WHICH WILL HAVE A LITTLE MORE IMPACT FOR THE TRI CITIES REGION...SOME CLOUD DEBRIS MAY HEAD SOUTHWARD LATE TONIGHT BUT REMAIN VFR FOR DET/DTW. FURTHER NORTH A LITTLE DIFFERENT STORY. AS WAS THE CASE THIS MORNING...CONVECTION ALBEIT HIGH BASED...WAS ABLE TO IMPACT LOCATIONS NORTH OF I69. EXPERIMENTAL 4KM ARW-WRF NCAR/NMM SUGGESTS ANOTHER SMALL MCS WILL INITIATE ACROSS SOUTH CENTRAL MINNESOTA AND MOVE ACROSS THE BAROCLINIC BOUNDARY THRU CENTRAL WISCONSIN INTO THE U.P. AND NORTHERN LOWER MICHIGAN. THIS WILL BRING A BIT LOWER CLOUD DECK FROM FNT TO MBS AND TOWARD SUNRISE WITH THE ADDITIONAL NOCTURNAL COOLING ALOFT...COULD BE ENOUGH TO BRING A CHANCE FOR MORE SHOWERS FOR THE TRI CITIES. THE 4KM ARW-WRF ALSO HINTS AT THIS POSSIBILITY AND WE WILL PLACE A PROB30 FOR MBS ONLY AFTER 12Z. FRONTAL SYSTEM ACROSS THE PLAINS BEGINS TO APPROACH THE TRI CITIES AFTER THE NOON HOUR WHERE CHANCES FOR ORGANIZED CONVECTION WILL INCREASE MONDAY AFTERNOON. && .UPDATE... ISSUED AT 925 AM EDT WHEN DRIVING INTO THE OFFICE THIS MORNING...WE WERE A BIT TAKEN BY THE AMOUNT OF ACCAS WHILE LOOKING NORTH. ELEVATED INSTABILITY IS QUITE A BIT MORE THAN PROGGED AND CONVECTION UPSTREAM HAS BEEN MORE ROBUST THAT NUMERICS SUGGESTED YESTERDAY. RAIN SHOWERS AND EMBEDDED THUNDER CONTINUE TO PUSH SOUTHWARD ACROSS THE NORTHERN 1/3RD OF THE CWA AND WE HAVE ALREADY UPDATED GRIDS/PRODUCTS TO ACCOUNT FOR THIS...BUT WHERE TO GO FROM HERE? NWP IS NOT MUCH HELP THIS MORNING WITH EVEN THE RUC NOT ONLY DRY BUT THETA-E MIN COMING ACROSS THE REGION. GIVEN OUTDOOR OBSERVATIONS AND UPSTREAM TRENDS...WE EXPECT THESE SHOWERS TO CONTINUE FOR THE MAJORITY OF THE MORNING BUT WITH HEATING AND WARM ADVECTION ALOFT...WE EXPECT THIS ACTIVITY TO WANE ACROSS SOUTHEAST LOWER MICHIGAN THIS AFTERNOON. WITH A FAIRLY DRY 12Z SOUNDING...AND NOT TO MENTION CLOUD DEBRIS FROM CONVECTION...WE WILL LIKELY MIX OUT OUR HIGHER SFC DEWPOINTS AND KEEP TEMPS A DOWN SEVERAL DEGREES. WE HAVE ALREADY MADE ADJUSTMENTS DOWNWARD IN THE MAX TEMPS BY ABOUT 3-5 DEGREES BUT STILL INTO THE LOWER 90S (HENCE NO HEADLINES FOR THE HEAT). && .SHORT TERM...TODAY AND TONIGHT MAIN CONCERN FOR THE SHORT TERM IS HEAT INDEX VALUES FOR THIS AFTERNOON. MODELS CONSISTENT IN INCREASING 925 MB TEMPS TO 28C...WHICH PRODUCED MAX TEMPS IN THE MID TO UPPER 90S OVER WISCONSIN ON SATURDAY. IN ADDITION SOUTHWEST FLOW TO INCREASE AS CENTER OF HIGH SINKS A LITTLE FURTHER SOUTH INTO THE OHIO VALLEY. UPPER 60S DEW POINTS WIDESPREAD OVER THE WESTERN OHIO VALLEY INTO WISCONSIN...AND WITH SOUTHWEST WINDS INCREASING TO 10 TO 15 KTS...ADVECTION OF UPPER 60S DEW POINTS INTO SOUTHEAST LOWER LOOKS REASONABLE THIS MORNING. HOWEVER GOOD DEEP MIXING TO TAKE PLACE AGAIN TODAY AND 850 MB AIR IS EVEN A LITTLE DRIER THAN SATURDAY. SO ANTICIPATE SURFACE DEW POINTS TO DROP BACK INTO THE MID 60S FOR THE AFTERNOON...KEEPING HEAT INDEX VALUES BELOW ADVISORY CRITERIA. IN ADDITION MOS DEW POINTS HAVE BEEN RUNNING A LITTLE TO HIGH IN THE AFTERNOON...AT THIS TIME PREFER THE TAMER MID 60S GFS DEW POINTS. ANOTHER CONCERN IS SOME CONVECTIVE DEBRIS CLOUD FROM CONVECTION OVER NORTHERN LOWER AND THE NORTHERN GREAT LAKES...WHICH COULD TRIM TEMPS A FEW DEGREES ACROSS THE NORTHERN THIRD OF THE CWA. VERY WARM 700 MB TEMPS OVER SOUTHERN LOWER WILL HELP TO KILL OFF CONVECTION AS IT MOVES FURTHER SOUTH...AND CURRENT CONVECTION OVER NORTHERN LOWER ALREADY WEAKENING WITH IR LOOP SHOWING SOME CLOUD TOP WARMING. SO ANTICIPATE BRIEF PERIODS OF SCT/BKN MID LEVEL CLOUDS ACROSS THE NORTHERN CWA TODAY AND TONIGHT. COMBINATION OF 15-20 MPH WINDS AND TEMPERATURES IN THE MID TO UPPER 90S ACROSS THE SAGINAW VALLEY BRINGS SOME FIRE WEATHER CONCERNS. HOWEVER WITH RECENT HEAVY RAINS OVER THE REGION AND RELATIVE HUMIDITY REMAINING ABOVE 30 PERCENT NO WARNINGS AT THIS TIME...EVEN IF SURFACE DEW POINTS FALL BACK INTO THE LOWER 60S THIS AFTERNOON RH VALUES WILL STILL REMAIN ABOVE THRESHOLDS. && .LONG TERM... WATER VAPOR IMAGERY AND 00Z RAOBS INDICATING A LARGE UPPER LEVEL RIDGE CENTERED OVER THE CENTRAL PLAINS...WITH THE RIDGE AXIS EXTENDING EAST INTO THE SOUTHERN OHIO VALLEY. THE 500 MB FLOW OVER THE GREAT LAKES IS NORTHWEST AT 40 TO 50 KNOTS. BASED ON THE RIDGE AXIS DISPLACED TO THE SOUTH...COUPLED WITH A MORE AMPLIFIED WAVE MOVING THROUGH ONTARIO ON MONDAY...SURFACE COLD FRONT IS NOW EXPECTED TO BE FASTER AND STRONGER...DRIVING SOUTH OF THE MICHIGAN BORDER TUESDAY MORNING. THERE IS NO DENYING THIS TREND BY ALL OF THE MODELS...AND WILL THUS SPEED UP THE CHANCE POPS FOR LATE MONDAY AFTERNOON ACROSS THE NORTHERN THIRD OF THE CWA. ANOTHER HOT DAY ON MONDAY OUT AHEAD OF THE FRONT...WITH MOSTLY MID 90S EXPECTED. WITH SLIGHTLY HIGHER DEW POINTS TOMORROW...HEAT INDICES WILL BE UP AROUND 100 DEGREES ONCE AGAIN. IF CAP WEAKENS AND STORMS ARE ABLE TO GO BY EARLY EVENING...THERE WILL BE THE POTENTIAL OF SEVERE WEATHER WITH THE MODERATE TO HIGH INSTABILITY (CAPES NEAR 3000 J/KG)...STEEP MID LEVEL LAPSE RATES AND 500 MB WIND MAX (40+ KNOTS) TRAVERSING THROUGH LOWER MICHIGAN. RELATIVE TO THE AIRMASS...LOW LEVEL MOISTURE IS NOT VERY HIGH AND CAN NOT JUSTIFY CARRYING MORE THAN CHANCE POPS AT THIS TIME...AS THE FRONT STILL COULD SLIDE THROUGH THE CWA RELATIVELY QUIET? WILL REMOVE POPS FOR TUESDAY ACROSS MUCH OF THE CWA...WITH THE EXCEPTION OF THE SOUTHERN THIRD...AS SURFACE HIGH (1018+ MB) BUILDS INTO LOWER MICHIGAN. THIS WAS THE SOLUTION THE PREVIOUS 00Z EUROPEAN RUNS WERE INDICATING...WHILE THE GFS WAS HANGING UP THE FRONT OVER THE SOUTHERN GREAT LAKES. VERIFICATION OVER THE PAST MONTH CONTINUES TO SHOW THE EUROPEAN DOMINANCE WITH RESPECT TO 500 MB HEIGHTS. AS MENTIONED EARLIER...THE UPPER LEVEL RIDGE AXIS DID NOT BECOME FIRMLY ESTABLISHED OVER THE SOUTHERN GREAT LAKES AND THE CENTER OF THE RIDGE RETROGRADES SLIGHTLY TO THE WEST. THERE IS ENOUGH OF A WEAKNESS OVER THE CENTRAL GREAT LAKES TO ALLOW THE FRONT TO PUSH SOUTH. NORTHERLY LOW LEVEL FLOW AND COLD ADVECTION THROUGH THE DAY TUESDAY SHOULD HOLD MAXES IN THE 80S. THE BIGGEST ADJUSTMENTS TO THE CURRENT FORECAST LOOK TO BE MADE TUESDAY NIGHT...WITH THE SURFACE HIGH OVER SOUTHEAST MICHIGAN...PROVIDING A GOOD RADIATING NIGHT. HAVE LOWERED MINS OVER 5 DEGREES (CLOSER TO NORMAL VALUES)...INTO THE UPPER 50S TO LOWER 60S (MID 60S CITY). NEXT PACIFIC WAVE TO TRACK ACROSS ONTARIO DURING THE MID WEEK PERIOD. WILL KEEP THE DAY PERIOD DRY ON WEDNESDAY AS THE SURFACE HIGH SLOWLY PUSHES OFF TO THE EAST...WITH WARM FRONT/MOISTURE SURGE NOT EXPECTED TO MOVE INTO EASTERN MICHIGAN UNTIL WEDNESDAY NIGHT. WITH THE POSSIBILITY OF PREFRONTAL ACTIVITY...WILL CARRY CHANCE POPS ALL DAY THURSDAY...WITH THE ACTUAL COLD FRONT STILL EXPECTED TO MOVE THROUGH LATE IN THE DAY/THURSDAY NIGHT. 12Z EUROPEAN THEN ADVERTISING A MAJOR SHIFT TO THE PATTERN...WITH A LONGWAVE TROUGH DEVELOPING OVER THE GREAT LAKES REGION DURING THE WEEKEND. A QUICK LOOK AT THE 00Z EUROPEAN REVEALS A LESS AMPLIFIED UPPER LEVEL TROUGH. NONE-THE-LESS...IT STILL SUPPORTS A DRY FORECAST WITH TEMPERATURES CLOSER TO NORMAL AS A LARGE SURFACE HIGH IS SITUATED ACROSS THE GREAT LAKES REGION. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MI WATERS OF LAKE ERIE...NONE. && $$ SHORT TERM...GSS LONG TERM....SF AVIATION.....GSS YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE). mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 925 AM EDT SUN JUL 16 2006 .UPDATE... WHEN DRIVING INTO THE OFFICE THIS MORNING...WE WERE A BIT TAKEN BY THE AMOUNT OF ACCAS WHILE LOOKING NORTH. ELEVATED INSTABILITY IS QUITE A BIT MORE THAN PROGGED AND CONVECTION UPSTREAM HAS BEEN MORE ROBUST THAT NUMERICS SUGGESTED YESTERDAY. RAIN SHOWERS AND EMBEDDED THUNDER CONTINUE TO PUSH SOUTHWARD ACROSS THE NORTHERN 1/3RD OF THE CWA AND WE HAVE ALREADY UPDATED GRIDS/PRODUCTS TO ACCOUNT FOR THIS...BUT WHERE TO GO FROM HERE? NWP IS NOT MUCH HELP THIS MORNING WITH EVEN THE RUC NOT ONLY DRY BUT THETA-E MIN COMING ACROSS THE REGION. GIVEN OUTDOOR OBSERVATIONS AND UPSTREAM TRENDS...WE EXPECT THESE SHOWERS TO CONTINUE FOR THE MAJORITY OF THE MORNING BUT WITH HEATING AND WARM ADVECTION ALOFT...WE EXPECT THIS ACTIVITY TO WANE ACROSS SOUTHEAST LOWER MICHIGAN THIS AFTERNOON. WITH A FAIRLY DRY 12Z SOUNDING...AND NOT TO MENTION CLOUD DEBRIS FROM CONVECTION...WE WILL LIKELY MIX OUT OUR HIGHER SFC DEWPOINTS AND KEEP TEMPS A DOWN SEVERAL DEGREES. WE HAVE ALREADY MADE ADJUSTMENTS DOWNWARD IN THE MAX TEMPS BY ABOUT 3-5 DEGREES BUT STILL INTO THE LOWER 90S (HENCE NO HEADLINES FOR THE HEAT). && .AVIATION... ISSUED 715 AM EDT SUN JUL 16 2006 SURFACE HIGH PRESSURE WILL REMAIN OVER THE OHIO VALLEY THROUGH THE TAF FORECAST PERIOD. AS A RESULT EXPECT VFR CONDITIONS ACROSS THE REGION THROUGH 12Z MONDAY. ONLY CLOUD COVER WILL BE CS AND AC DEBRIS CLOUD DUE TO ONGOING CONVECTION ACROSS NORTHERN LOWER AND THE NORTHERN GREAT LAKES. MOST OF THIS DEBRIS CLOUD WILL BE NORTH OF DTW/DET. WILL HAVE TO CONTEND WITH MORE CONVECTIVE DEBRIS CLOUD OVERNIGHT AS LOW LEVEL JET MOVES A LITTLE FURTHER EAST. GOOD MIXING LATE THIS MORNING THROUGH MID AFTERNOON AS LAPSE RATES BECOME NEARLY DRY ADIABATIC THROUGH 700 MB...SO ANTICIPATE 10-15 KT SURFACE WINDS TO DEVELOP AND PROBABLY SOME GUSTINESS IN THE SAGINAW VALLEY...FURTHER AWAY FROM THE CORE OF THE HIGH PRESSURE SYSTEM AND IN STRONGER SOUTHWEST FLOW ALONG THE NORTHERN BOUNDARY OF THIS HIGH. MODELS SHOW AN INVERSION FORMING BY 00Z THOUGH AS 850 MB TEMPS CONTINUE TO WARM AS A RESULT GUSTY WINDS MAY BE SHORT LIVED AND CONFINED TO 18-21Z. && .SHORT TERM...TODAY AND TONIGHT MAIN CONCERN FOR THE SHORT TERM IS HEAT INDEX VALUES FOR THIS AFTERNOON. MODELS CONSISTENT IN INCREASING 925 MB TEMPS TO 28C...WHICH PRODUCED MAX TEMPS IN THE MID TO UPPER 90S OVER WISCONSIN ON SATURDAY. IN ADDITION SOUTHWEST FLOW TO INCREASE AS CENTER OF HIGH SINKS A LITTLE FURTHER SOUTH INTO THE OHIO VALLEY. UPPER 60S DEW POINTS WIDESPREAD OVER THE WESTERN OHIO VALLEY INTO WISCONSIN...AND WITH SOUTHWEST WINDS INCREASING TO 10 TO 15 KTS...ADVECTION OF UPPER 60S DEW POINTS INTO SOUTHEAST LOWER LOOKS REASONABLE THIS MORNING. HOWEVER GOOD DEEP MIXING TO TAKE PLACE AGAIN TODAY AND 850 MB AIR IS EVEN A LITTLE DRIER THAN SATURDAY. SO ANTICIPATE SURFACE DEW POINTS TO DROP BACK INTO THE MID 60S FOR THE AFTERNOON...KEEPING HEAT INDEX VALUES BELOW ADVISORY CRITERIA. IN ADDITION MOS DEW POINTS HAVE BEEN RUNNING A LITTLE TO HIGH IN THE AFTERNOON...AT THIS TIME PREFER THE TAMER MID 60S GFS DEW POINTS. ANOTHER CONCERN IS SOME CONVECTIVE DEBRIS CLOUD FROM CONVECTION OVER NORTHERN LOWER AND THE NORTHERN GREAT LAKES...WHICH COULD TRIM TEMPS A FEW DEGREES ACROSS THE NORTHERN THIRD OF THE CWA. VERY WARM 700 MB TEMPS OVER SOUTHERN LOWER WILL HELP TO KILL OFF CONVECTION AS IT MOVES FURTHER SOUTH...AND CURRENT CONVECTION OVER NORTHERN LOWER ALREADY WEAKENING WITH IR LOOP SHOWING SOME CLOUD TOP WARMING. SO ANTICIPATE BRIEF PERIODS OF SCT/BKN MID LEVEL CLOUDS ACROSS THE NORTHERN CWA TODAY AND TONIGHT. COMBINATION OF 15-20 MPH WINDS AND TEMPERATURES IN THE MID TO UPPER 90S ACROSS THE SAGINAW VALLEY BRINGS SOME FIRE WEATHER CONCERNS. HOWEVER WITH RECENT HEAVY RAINS OVER THE REGION AND RELATIVE HUMIDITY REMAINING ABOVE 30 PERCENT NO WARNINGS AT THIS TIME...EVEN IF SURFACE DEW POINTS FALL BACK INTO THE LOWER 60S THIS AFTERNOON RH VALUES WILL STILL REMAIN ABOVE THRESHOLDS. && .LONG TERM... WATER VAPOR IMAGERY AND 00Z RAOBS INDICATING A LARGE UPPER LEVEL RIDGE CENTERED OVER THE CENTRAL PLAINS...WITH THE RIDGE AXIS EXTENDING EAST INTO THE SOUTHERN OHIO VALLEY. THE 500 MB FLOW OVER THE GREAT LAKES IS NORTHWEST AT 40 TO 50 KNOTS. BASED ON THE RIDGE AXIS DISPLACED TO THE SOUTH...COUPLED WITH A MORE AMPLIFIED WAVE MOVING THROUGH ONTARIO ON MONDAY...SURFACE COLD FRONT IS NOW EXPECTED TO BE FASTER AND STRONGER...DRIVING SOUTH OF THE MICHIGAN BORDER TUESDAY MORNING. THERE IS NO DENYING THIS TREND BY ALL OF THE MODELS...AND WILL THUS SPEED UP THE CHANCE POPS FOR LATE MONDAY AFTERNOON ACROSS THE NORTHERN THIRD OF THE CWA. ANOTHER HOT DAY ON MONDAY OUT AHEAD OF THE FRONT...WITH MOSTLY MID 90S EXPECTED. WITH SLIGHTLY HIGHER DEW POINTS TOMORROW...HEAT INDICES WILL BE UP AROUND 100 DEGREES ONCE AGAIN. IF CAP WEAKENS AND STORMS ARE ABLE TO GO BY EARLY EVENING...THERE WILL BE THE POTENTIAL OF SEVERE WEATHER WITH THE MODERATE TO HIGH INSTABILITY (CAPES NEAR 3000 J/KG)...STEEP MID LEVEL LAPSE RATES AND 500 MB WIND MAX (40+ KNOTS) TRAVERSING THROUGH LOWER MICHIGAN. RELATIVE TO THE AIRMASS...LOW LEVEL MOISTURE IS NOT VERY HIGH AND CAN NOT JUSTIFY CARRYING MORE THAN CHANCE POPS AT THIS TIME...AS THE FRONT STILL COULD SLIDE THROUGH THE CWA RELATIVELY QUIET? WILL REMOVE POPS FOR TUESDAY ACROSS MUCH OF THE CWA...WITH THE EXCEPTION OF THE SOUTHERN THIRD...AS SURFACE HIGH (1018+ MB) BUILDS INTO LOWER MICHIGAN. THIS WAS THE SOLUTION THE PREVIOUS 00Z EUROPEAN RUNS WERE INDICATING...WHILE THE GFS WAS HANGING UP THE FRONT OVER THE SOUTHERN GREAT LAKES. VERIFICATION OVER THE PAST MONTH CONTINUES TO SHOW THE EUROPEAN DOMINANCE WITH RESPECT TO 500 MB HEIGHTS. AS MENTIONED EARLIER...THE UPPER LEVEL RIDGE AXIS DID NOT BECOME FIRMLY ESTABLISHED OVER THE SOUTHERN GREAT LAKES AND THE CENTER OF THE RIDGE RETROGRADES SLIGHTLY TO THE WEST. THERE IS ENOUGH OF A WEAKNESS OVER THE CENTRAL GREAT LAKES TO ALLOW THE FRONT TO PUSH SOUTH. NORTHERLY LOW LEVEL FLOW AND COLD ADVECTION THROUGH THE DAY TUESDAY SHOULD HOLD MAXES IN THE 80S. THE BIGGEST ADJUSTMENTS TO THE CURRENT FORECAST LOOK TO BE MADE TUESDAY NIGHT...WITH THE SURFACE HIGH OVER SOUTHEAST MICHIGAN...PROVIDING A GOOD RADIATING NIGHT. HAVE LOWERED MINS OVER 5 DEGREES (CLOSER TO NORMAL VALUES)...INTO THE UPPER 50S TO LOWER 60S (MID 60S CITY). NEXT PACIFIC WAVE TO TRACK ACROSS ONTARIO DURING THE MID WEEK PERIOD. WILL KEEP THE DAY PERIOD DRY ON WEDNESDAY AS THE SURFACE HIGH SLOWLY PUSHES OFF TO THE EAST...WITH WARM FRONT/MOISTURE SURGE NOT EXPECTED TO MOVE INTO EASTERN MICHIGAN UNTIL WEDNESDAY NIGHT. WITH THE POSSIBILITY OF PREFRONTAL ACTIVITY...WILL CARRY CHANCE POPS ALL DAY THURSDAY...WITH THE ACTUAL COLD FRONT STILL EXPECTED TO MOVE THROUGH LATE IN THE DAY/THURSDAY NIGHT. 12Z EUROPEAN THEN ADVERTISING A MAJOR SHIFT TO THE PATTERN...WITH A LONGWAVE TROUGH DEVELOPING OVER THE GREAT LAKES REGION DURING THE WEEKEND. A QUICK LOOK AT THE 00Z EUROPEAN REVEALS A LESS AMPLIFIED UPPER LEVEL TROUGH. NONE-THE-LESS...IT STILL SUPPORTS A DRY FORECAST WITH TEMPERATURES CLOSER TO NORMAL AS A LARGE SURFACE HIGH IS SITUATED ACROSS THE GREAT LAKES REGION. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...NONE. LAKE ST CLAIR...NONE. MI WATERS OF LAKE ERIE...NONE. && $$ SHORT TERM...GSS LONG TERM....SF AVIATION.....GSS YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE). mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DULUTH MN 856 PM CDT SUN JUL 16 2006 .UPDATE... PLAN ON UPDATING ZONE FORECAST PRODUCT JUST FOR SOME TWEAKS- NOTHING MAJOR. STORMS STILL A POSSIBILITY AHEAD OF FRONT THAT WAS OVR NWRN MN THIS EVENING. MORE STORMS COULD FIRE AS UPPER LEVEL VOR MAXES MOVE ACROSS WITH TROF. ONE WILL BE SLIDING DOWN FROM CANADA THEN MOVE ACROSS NRN MN AND FAR NRN WI TNT AND THE OTHER WILL BE SLIDING ACROSS THE SRN HALF OF MN. LOOKS LIKE THE NRN ONE MAY HAVE THE BEST CHC OF GIVING THE NORTHLAND SOME MORE RAIN TNT. && .PREV DISCUSSION... (ISSUED 233 PM CDT SUN JUL 16 2006) DISCUSSION...ANOTHER WARM AFTERNOON WITH MANY 90'S ACROSS OUR CWA. LAKE BREEZE KICKED IN EARLY THIS AFTERNOON...COOLING THE IMMEDIATE LAKESHORE AREAS UP THE SHORE...DOWN TO THE TWIN PORTS AREA. HUMIDITY IS A BIT HIGHER...AND THE HEAT INDEX IS AT OR IN SOME CASES SLIGHTLY HIGHER THAN YESTERDAYS VALUES AND WAS RUNNING FROM 90-103 MOST AREAS. A WEAK CONVERGENCE AXIS WAS DRAPED ACROSS OUR CWA...JUST NORTH OF KXVG-KCOQ EAST OVER LAKE SUPERIOR. CONVERGENCE ALONG THIS BOUNDARY IS WEAK IN THE LIGHT LOW LEVEL FLOW. THERE IS HOWEVER PLENTY OF INSTABILITY THIS AFTERNOON...WITH SBCAPES FROM 2000-2500 J/KG OVER MUCH OF OUR CWA...AND MLCAPES MORE VARAIBLE ACCORDING TO SPC'S RUC ANALYSIS. THERE ARE POCKETS OF 2000-2500 J/KG. ONE OF THE LIMITING FACTORS IN GETTING THUNDERSTORMS TO DEVELOP HAS BEEN HIGH CIN VALUES. RUC FORECASTING DECREASING CIN VALUES...WITH LESS THAN 25 IN SPOTS OVER NORTHERN WISCONSIN WEST INTO NORTHERN MINNESOTA AT 19Z. HOWEVER...NAM BUFR SOUNDINGS SHOW A STRONG CAP REMAINING IN PLACE FOR THE REST OF THE AFTERNOON AND EVENING. 06Z NAM DID SHOW A WEAKENING CAP AROUND 22Z. THE TRUTH IS PROBABLY SOMEWHERE BETWEEN THE TWO EXTREMES. LATEST RADAR AND SATELLITE VISIBLE IMAGERY SHOW CU FIELD FORMING OVER NORTHERN MINNESOTA. HIGH CLOUDS HAVE BEEN INCREASING OVER OUR SOUTHERN MN ZONES INTO NORTHERN WISCONSIN...WHICH IS BLOW OFF FROM SOUTHERN-CENTRAL MINNESOTA SHOWERS/THUNDERSTORMS. WE WILL CONTINUE TO CARRY 20-40 PERCENT POP'S TONIGHT WITH UNSTABLE AIRMASS IN PLACE AND A WAVE AND BOUNDARY TO MOVE THROUGH. INITIATION TIME OF STORMS IS NOT CLEAR CUT. A WAVE MOVING THROUGH SOUTH DAKOTA WILL HELP WEAKEN THE CAP AND PROVIDE LARGE SCALE LIFT LATER THIS EVENING...AND THE WEAK SURFACE BOUNDARY ALREADY IN PLACE COULD BE ENOUGH TO GET A FEW STORMS GOING AS WELL YET THIS AFTERNOON. 875/900MB WINDS WILL BE INCREASING THIS EVENING AS WELL TO 30-35KT...JUST AHEAD OF THE TROUGH BETWEEN 00-03Z. IF STORMS DO GO...THERE IS PLENTY OF SHEAR IN PLACE FOR ORGANIZED STORMS...WITH SEVERE WINDS AND SOME HAIL THE MAIN THREATS. THE COOL FRONT WILL MOVE THROUGH OUR CWA MONDAY MORNING...WITH HIGH PRESSURE BUILDING IN BRINGING COOLER TEMPERATURES AND LOWER HUMIDITY. LOW LEVEL FLOW WILL TURN BACK OUT OF THE SOUTH ON TUESDAY...WITH A CHANCE FOR MORE THUNDERSTORMS TUESDAY NIGHT INTO WEDNESDAY AS A TROUGH AND SHORTWAVE SWING THROUGH. A BLEND OF NAM/GFS MOS WAS USED FOR TEMPERATURES. && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. $$ CLC mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DULUTH MN 233 PM CDT SUN JUL 16 2006 .DISCUSSION...ANOTHER WARM AFTERNOON WITH MANY 90'S ACROSS OUR CWA. LAKE BREEZE KICKED IN EARLY THIS AFTERNOON...COOLING THE IMMEDIATE LAKESHORE AREAS UP THE SHORE...DOWN TO THE TWIN PORTS AREA. HUMIDITY IS A BIT HIGHER...AND THE HEAT INDEX IS AT OR IN SOME CASES SLIGHTLY HIGHER THAN YESTERDAYS VALUES AND WAS RUNNING FROM 90-103 MOST AREAS. A WEAK CONVERGENCE AXIS WAS DRAPED ACROSS OUR CWA...JUST NORTH OF KXVG-KCOQ EAST OVER LAKE SUPERIOR. CONVERGENCE ALONG THIS BOUNDARY IS WEAK IN THE LIGHT LOW LEVEL FLOW. THERE IS HOWEVER PLENTY OF INSTABILITY THIS AFTERNOON...WITH SBCAPES FROM 2000-2500 J/KG OVER MUCH OF OUR CWA...AND MLCAPES MORE VARAIBLE ACCORDING TO SPC'S RUC ANALYSIS. THERE ARE POCKETS OF 2000-2500 J/KG. ONE OF THE LIMITING FACTORS IN GETTING THUNDERSTORMS TO DEVELOP HAS BEEN HIGH CIN VALUES. RUC FORECASTING DECREASING CIN VALUES...WITH LESS THAN 25 IN SPOTS OVER NORTHERN WISCONSIN WEST INTO NORTHERN MINNESOTA AT 19Z. HOWEVER...NAM BUFR SOUNDINGS SHOW A STRONG CAP REMAINING IN PLACE FOR THE REST OF THE AFTERNOON AND EVENING. 06Z NAM DID SHOW A WEAKENING CAP AROUND 22Z. THE TRUTH IS PROBABLY SOMEWHERE BETWEEN THE TWO EXTREMES. LATEST RADAR AND SATELLITE VISIBLE IMAGERY SHOW CU FIELD FORMING OVER NORTHERN MINNESOTA. HIGH CLOUDS HAVE BEEN INCREASING OVER OUR SOUTHERN MN ZONES INTO NORTHERN WISCONSIN...WHICH IS BLOW OFF FROM SOUTHERN-CENTRAL MINNESOTA SHOWERS/THUNDERSTORMS. WE WILL CONTINUE TO CARRY 20-40 PERCENT POP'S TONIGHT WITH UNSTABLE AIRMASS IN PLACE AND A WAVE AND BOUNDARY TO MOVE THROUGH. INITIATION TIME OF STORMS IS NOT CLEAR CUT. A WAVE MOVING THROUGH SOUTH DAKOTA WILL HELP WEAKEN THE CAP AND PROVIDE LARGE SCALE LIFT LATER THIS EVENING...AND THE WEAK SURFACE BOUNDARY ALREADY IN PLACE COULD BE ENOUGH TO GET A FEW STORMS GOING AS WELL YET THIS AFTERNOON. 875/900MB WINDS WILL BE INCREASING THIS EVENING AS WELL TO 30-35KT...JUST AHEAD OF THE TROUGH BETWEEN 00-03Z. IF STORMS DO GO...THERE IS PLENTY OF SHEAR IN PLACE FOR ORGANIZED STORMS...WITH SEVERE WINDS AND SOME HAIL THE MAIN THREATS. THE COOL FRONT WILL MOVE THROUGH OUR CWA MONDAY MORNING...WITH HIGH PRESSURE BUILDING IN BRINGING COOLER TEMPERATURES AND LOWER HUMIDITY. LOW LEVEL FLOW WILL TURN BACK OUT OF THE SOUTH ON TUESDAY...WITH A CHANCE FOR MORE THUNDERSTORMS TUESDAY NIGHT INTO WEDNESDAY AS A TROUGH AND SHORTWAVE SWING THROUGH. A BLEND OF NAM/GFS MOS WAS USED FOR TEMPERATURES. && .POINT FORECAST TEMPS/POPS... DLH 64 83 58 79 / 40 10 10 10 INL 62 80 51 84 / 20 10 10 10 BRD 68 84 57 87 / 30 10 10 10 HYR 69 88 53 86 / 40 20 10 10 ASX 66 85 55 82 / 40 20 10 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. $$ MELDE mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CLEVELAND OHIO 703 AM EDT SUN JUL 16 2006 .AVIATION(12Z-12Z)... QUIET WEATHER ON TAP NEXT 24 HOURS. COMPLEX RACING SOUTHEAST TOWARD THE FORECAST AREA OUT OF UPPER MICHIGAN WILL NOT SURVIVE LONG ENOUGH TO MAKE IT INTO THE FORECAST AREA. COMPLEX APPEARS TO BE FEEDING OFF LOW LEVEL NOCTURNAL JET THAT EXTENDS WEST TO EAST IN THE VICINITY OF THE COMPLEX. RUC MODEL SHOWS SHORTWAVE DIVING SOUTHEAST ALONG WITH ASSOCIATED MOISTURE BUT THIS FEATURE WEAKENS AND NEARLY DISSIPATES BEFORE REACHING ERIE PA. SO WILL KEEP THE FORECAST AREA DRY THROUGH THE NEXT 24 HOURS. ONLY OTHER CONCERN IS SOME MVFR VSBY THIS MORNING WITH HIGH DEWPOINTS. FOG SHOULD DISSIPATE ALL AREAS BUT REMAIN A LITTLE HAZY AT ERIE THROUGH THE DAY. MORE HAZE AND MIST TO DEVELOP AFTER 08Z AGAIN TONIGHT. LIGHT SOUTH TO SOUTHWEST WINDS WILL OCCUR TODAY DIMINISHING TO CALM TONIGHT. && .SHORT TERM(TODAY THROUGH MONDAY NIGHT)... STRONG UPPER LEVEL RIDGE WILL REMAIN IN PLACE ACROSS THE OHIO VALLEY AND LOWER GREAT LAKES THROUGH MONDAY. THIS WILL GIVE US THE HOTTEST WEATHER OF THE YEAR THUS FAR. 850 MB TEMPS PUSH TO 23C WHILE SFC DEW POINTS WILL LINGER IN THE 65F TO 70F RANGE. CURRENTLY NOT A CLOUD IN THE SKY...BUT CIRRUS BLOW OFF FROM MCS UPPER MISSISSIPPI VALLEY SHOULD SPREAD ACROSS THE FORECAST AREA BY LATE MORNING. THIS WILL HELP KEEP TEMPS IN THE LOWER TO MID 90S ACROSS THE AREA (A LITTLE COOLER NEAR THE LAKESHORE). FORECAST QUESTION OF THE DAY WAS WHETHER OR NOT TO ISSUE A HEAT ADVISORY FOR THE WESTERN COUNTIES. EXPECT CIRRUS SHIELD TO HELP KEEP TEMPS IN THE WRN COUNTIES TO THE MID 90S...WHILE AFTERNOON MIXING SHOULD HELP KEEP DEW POINTS IN THE MID 60S. THIS WOULD PRODUCE HEAT INDICES IN THE UPPER 90S...WHICH IS JUST BELOW HEAT ADVISORY CRITERIA. EXPECT CONDTIONS TO EXCEED HEAT INDEX OF 100 DEGREES FOR WRN HALF OF FORECAST AREA MONDAY. MOS TEMPS HAVE BEEN RUNNING HIGH THE PAST FEW DAYS...AND I EXPECT THE SAME TODAY. SHAVED A FEW DEGREES OF MOS HIGH TEMPS FOR TODAY AND MONDAY. && .LONG TERM (TUESDAY THROUGH SATURDAY)... IT LOOKS LIKE THE WARM AND MUGGY WX WILL CONTINUE THRU THE EXTENDED WITH H5 HEIGHTS STAYING AROUND 590DM THRU THU WITH H8 TEMPS AROUND +20C. THE GFS AND ECMWF SHOW THE WESTERLIES STAYING N OF THE AREA THRU THU AT LEAST WHICH SHOULD KEEP ANY SIGNIFICANT WEATHER OUT OF THE AREA UNTIL THEN. THE GFS SUGGESTS A WASHED OUT FRONT WILL MOVE INTO THE SOUTHERN LAKES TUE NIGHT INTO WED. THIS MAY SERVE AS A FOCUS FOR SOME CONVECTION AS H7 TEMPS ARE PROGGED TO LOWER TO +8C WHICH SHOULD HELP WEAKEN THE CAP. WL KEEP 30 PCT POPS FOR THE REGION TUE INTO WED. THE RIDGE BUILDS BACK INTO THE AREA THU WITH AN INCREASING CAP. WL KEEP THU DRY WITH LACK OF FOCUSING. THE GFS POINT TO THE TROUGH AMPLIFYING OVER THE GREAT LAKES FRIDAY INTO SATURDAY. THIS ALLOWS THE WESTERLIES TO MOVE SOUTH AND PLACES THE REGION IN NW FLOW. THIS MAY EVENTUALLY OPEN THE DOOR FOR MCS ACTIVITY LATE IN THE EXTENDED BUT THIS IS CERTAINLY TOO FAR OUT IN TIME TO PIN DOWN DETAILS. FOR NOW...HAVE OPTED TO GO WITH 40 PCT POPS FRI THRU SAT. && .CLE WATCHES/WARNINGS/ADVISORIES... .OH...NONE. .PA...NONE. && $$ SHORT TERM...DJB LONG TERM...MRD AVIATION...LOMBARDY $$ oh AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE LA CROSSE WI 1205 PM CDT SUN JUL 16 2006 .UPDATE... HAVE UPDATED FORECAST PACKAGE TO CANCEL HEAT ADVISORY ACROSS THE NORTHERN PARTS OF THE FORECAST AREA. THIS COORDINATED WITH KMPX OFFICE. CONVECTIVE DEBRIS CLOUDS AND SCT -SHRA/ISOLATED -TSRA HAVE LIMITED HEATING/WARMING SO FAR TODAY. 850-700MB MOISTURE TRANSPORT INTO THE WEAK CONVERGENCE ZONE OVER CENTRAL MN/WI CONTINUES TO WEAKEN...BUT STILL PLENTY OF CLOUDS TO MOVE ACROSS THE NORTHERN PARTS OF THE FORECAST AREA THROUGH THE EARLY AFTERNOON HOURS. EVEN MORE CLOUDS UPSTREAM OVER EASTERN SD...IN CONVERGENT AREA AHEAD OF CENTRAL SD SFC LOW AND MDT SHORTWAVE OVER WESTERN SD. THUS...PARTLY SUNNY AT BEST ACROSS THE NORTH END OF THE FORECAST AREA THIS AFTERNOON. HIGHS FOR THESE AREAS NORTH OF KLSE TO KMDZ EXPECTED TO BE SOME 5F COOLER THAN EARLIER THOUGHT. HEAT INDICES IN THESE AREA EXPECTED TO TOP OUT IN THE 95 TO 100 RANGE AND BELOW ADVISORY CRITERIA. && RRS .PREV DISCUSSION... /ISSUED 329 AM CDT SUN JUL 16 2006/ ..DANGEROUS HEAT TO CONTINUE TODAY...BUT RELIEF ON THE WAY... SHORT TERM...THROUGH WEDNESDAY HIGH HEAT INDICES AGAIN GRAB FORECAST ATTENTION TODAY...WITH THUNDERSTORM CHANCES BECOMING OF INCREASING CONCERN...WITH SIGNIFICANT PATTERN CHANGE TAKING PLACE THROUGH THE END OF THE WORK WEEK. 00Z RAOB/UPPER AIR ANALYSIS SHOWED 600DM H5 RIDGE STILL SITTING OVER THE FOUR CORNERS REGION...AND HAD EXPANDED EWRD INTO THE GREAT LAKES. FAST BELT OF MID/UPPER TROPOSPHERIC FLOW /100KT H25 JET/ EXTENDED IN WEST-EAST FASHION ATOP THE SUBTROPICAL RIDGE...ACROSS THE SRN TIER OF THE CANADIAN PROVINCES...WITH THE SRN FRINGE OF THIS WESTERLY FLOW AND ITS ASSOCIATED MINOR PERTURBATIONS ACROSS THE NRN CONUS. LOW LEVEL HEAT PLUME /WHICH PRODUCED ALL TIME RECORDS IN SD YDAY/ HAD SPREAD INTO THE AREA EVIDENCED BY H85 TEMPS IN THE MID 20S /C/ RANGE ACROSS THE AREA. WEAK WAVE TRAVERSING THE FLOW HAD INDUCED A 40KT H85 JET OVERNIGHT WHICH HAS LED TO A VERY HIGH BASED...BUT NONETHELESS QUITE IMPRESSIVE LITTLE MCS OVER CENTRAL MINNESOTA THIS MORNING. THESE STORMS ROOTED ABOUT 650MB PER RUC SOUNDINGS. OF CONCERN TODAY IS THE EVOLUTION OF THE CURRENT CNTL MN ACTIVITY..ITS AFFECTS ON TEMPS...HEAT INDICES...AND WHETHER STORMS WILL REFIRE THIS AFTERNOON IN THE NORTH. LOW LEVEL JET AND WEAK WAVE TO MOVE STORMS ALONG QUICKLY THIS MORNING...MAINLY NORTH OF CWA. SRN EXTENT OF STORMS HOWEVER...SEEMS LIKE IT WILL AFFECT NWRN CWA AT LEAST THROUGH 14 OR 15Z...MOST LIKELY IN A WEAKENED STATE DUE TO DIURNAL MIXING/VEERING OF THE LOW LEVEL JET. WILL INCLUDE A SMALL MORNING POP IN THE WEST/NORTH FOR THIS ACTIVITY. WHILE THE RESIDUAL CLOUDS WILL SPILL ACROSS THE NRN 1/2 OF THE CWA THIS MORNING...WILL LITTLE TO CURB OVERALL HEAT...AS SUBSIDENCE IN THE WAKE OF THIS WAVE...AND INCREASING MIXING WILL ALLOW STRONG SUNSHINE TO DEVELOP AGAIN BY LATE MORNING/AFTERNOON ACROSS THE AREA...ESP SRN 2/3 OF CWA. GIVEN NAM/RUC/GFS AGAIN POINTING TO H9 TEMPS /MIXING HEIGHT/ TO 28 OR 29 /C/...STILL THINK EXTREME HEAT WILL BE PRESENT OVER CWA TODAY...WITH RUC/GFS SHOWING HIGHEST THREAT TO HIT 100 DEGREE MARK FROM LSE EAST TO SPARTA AND TOMAH...WHERE LOW LEVEL MOISTURE AGAIN WILL MIX OUT WITH DEWPOINTS FALLING INTO THE LOWER AND MIDDLE 60S /IN LOWER 70S NOW/. WHILE HEAT INDICES WILL BE MARGINAL OVERALL...THINK GOING HEAT ADVRY IS JUSTIFIED...ESP GIVEN RUC INDICATING PRIMARILY LOW LEVEL THERMAL AXIS CENTERED DIRECTLY OVER ARX CWA...ALONG I-90 IN EARLY AFTERNOON. WORRIED SOME CASTELLANUS WILL IMPEDE HEATING A LITTLE IN THE NORTH...BUT NOT CONFIDENT ENOUGH IN THIS TO HAVE DRASTIC FORECAST IMPLICATIONS. WILL CONTINUE TO CARRY LOW POPS IN NRN CWA IN AFTERNOON IN CONVERGENCE ZONE ACROSS CNTL MN INTO CNTL WISC. NEXT WAVE IN WRN SD WILL BE APPROACHING BY LATE AFTN/EVE AND WORRIED THERE MAY BE ENOUGH GIVEN VERY STEEP LAPSE RATES TO INITIATE SCATTERED CONVECTION. WHILE ANY STORM WILL BE VERY HIGH BASED...INVERTED V PROFILES AND STEEP LAPSE RATES WILL SUPPORT A WIND THREAT WITH ANY STORM IN THE NORTH THIS AFTERNOON OR EVENING. FRONTAL BOUNDARY TOWARD CWA BY LATE TONIGHT...DRIVEN EAST BY STRONGER WAVE DROPPING THROUGH CNTL CANADA TROUGH WELL TO THE NORTH...AND INCREASING LOW LEVEL JET AND MOISTURE TRANSPORT WILL TEAM WITH PLENTY OF INSTABILITY FOR SCATTERED CONVECTION AFTER MIDNIGHT. ERRATIC SIGNALS AMONG THE VARIOUS OPNL/ENSEMBLE MEANS ON WHERE/IF ANY SMALL MCS MAY OCCUR OVERNIGHT...BUT FELT ENOUGH FORCING THERE GIVEN WHAT HAPPENED IN THE LAST FEW HOURS TO EXPAND POPS A LITTLE FURTHER EAST INTO CWA...PRIMARILY AFTER MIDNIGHT. WILL BE VERY WARM OVERNIGHT GIVEN INCREASING LOW LEVEL FLOW AND THERMAL AXIS REMAINING ACROSS THE AREA. FRONT WILL SLIP THROUGH MONDAY MORNING INTO EARLY AFTERNOON...WITH BEST CHANCE FOR CONVECTION IN THE ERN/SERN CWA AFT 18Z. WILL BE BATTLING RESIDUAL CAPPING ISSUES AS HEIGHTS CONTINUE TO FALL AND HEAT BEGINS TO QUICKLY GET PUSHED BACK TO THE SOUTHWEST. THINK CONVECTION WILL FIRE ALONG THE BOUNDARY IN THE AFTERNOON...AND CONTINUED THIS THINKING IN THE GRIDS. DRIER/COOLER AIR SPREADS ACROSS CWA AS MODELS CONTINUE TO DRIVE FRONT FURTHER SOUTH WITH EVERY RUN...WITH STRONGER INFLUENCE FROM THE NRN STREAM. FRONT IS PUSHED FAR ENOUGH SOUTH TUESDAY...FOR A COOLER AND DRIER DAY...WITH SUNSHINE AND CLOUDS. HOWEVER...RIDGE WANTS TO BUILD BACK NORTH WITH RETURNING WARM FRONT AHEAD OF STRONGER WAVE DUE IN WED. THIS SHOULD LEAD TO AN ACTIVE WX PERIOD TUE NIGHT/WED WITH LIKELY A STRONG MCS IN THE IA/MN/WI REGION TUESDAY NIGHT. GIVEN PROXIMITY OF DEEP HEAT POOL...AND AMPLE MOISTURE SURGING IN...COULD BE A RATHER VIGOROUS MCS TUES NIGHT. LOCATION STILL IN QUESTION...MAY BE FURTHER WEST IN STRONGEST CONVERGENCE ZONE OF LOW LEVEL JET...WITH DEBRIS INTO CWA LATE. LONG TERM... STILL SEEING INDICATIONS OF TROUGH TO DEVELOP ACROSS NERN 1/3 OF CONUS THROUGH NEXT WEEKEND...WHICH ACTUALLY ALLOWS SOME NEGATIVE H5 HEIGHT ANOMALIES TO CREEP SOUTH INTO THE NRN CONUS. THIS SHOULD LEAD TO H85 TEMPS IN THE 15C RANGE NEXT WEEKEND...SO BIG RELIEF TO CURRENT HEAT IS ON THE HORIZON. WILL NEED TO GET THROUGH SOME ACTIVE WEATHER WED-FRI AS WE RID THE HEAT AND CHANGE PATTERN. SHOULD SEE HIGHS FALL BACK INTO THE LOW/MID 80S. FIRE WEATHER... VERY SIMILAR FIRE WX DAY AS YESTERDAY. HOLDING OFF ON RED FLAG WARNING DUE TO MARGINAL HUMIDITIES /EXPECT MAINLY 30 TO 35 PERCENT/. WINDS WILL BE 13 TO 16 MPH MOST AREAS...WITH GUSTS...SO DEFINITELY A HIGH FIRE DANGER DAY. DAY SHIFT CAN MONITOR IF MIXING TAKES DEWPOINTS LOWER THAN CURRENTLY ANTICIPATED...AND HOIST WARNING IF NEEDED FOR AFTERNOON/EVENING HOURS. .ARX WATCHES/WARNINGS/ADVISORIES... WI...HEAT ADVISORY UNTIL 4 AM CDT MONDAY FOR WIZ041-WIZ042-WIZ043- WIZ044-WIZ053-WIZ054-WIZ055-WIZ061. MN...HEAT ADVISORY UNTIL 4 AM CDT MONDAY FOR MNZ079-MNZ086-MNZ087- MNZ088-MNZ094-MNZ095-MNZ096. IA...HEAT ADVISORY UNTIL 4 AM CDT MONDAY FOR IAZ008-IAZ009-IAZ010- IAZ011-IAZ018-IAZ019-IAZ029-IAZ030. && $$ BINAU/RRS wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 410 AM EDT MON JUL 17 2006 .DISCUSSION... THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS THE POTENTIAL FOR THUNDERSTORMS TODAY. WATER VAPOR IMAGERY AND RUC DEPICTS A NEAR ZONAL FLOW ALONG THE INTERNATIONAL BORDER OF CANADA AND CONUS. A NUMBER OF SHORTWAVES CONTINUE TO RACE EAST IN THIS FLOW. THE MOST SIGNIFICANT ONES AFFECTING THIS AREA ARE OVER EASTERN U.P. AND OVER SOUTHERN MANITOBA AND WESTERN ONTARIO. SURFACE ANALYSIS SHOWING A LOW OVER NORTH CENTRAL LAKE SUPERIOR WITH A COLD FRONT DRAPED SOUTHWEST INTO NORTHEAST NEBRASKA. THE SHORTWAVE OVER SOUTH CENTRAL CANADA WILL SWEEP INTO WESTERN LAKE SUPERIOR THIS MORNING AND ACROSS THE REST OF THE FORECAST AREA THIS AFTERNOON. A 1016 MB SURFACE RIDGE BEHIND THE SHORTWAVE WILL PUSH THE COLD FRONT THROUGH THE FORECAST AREA BY 18Z REACHING NORTHERN LOWER MICHIGAN BY LATE AFTERNOON. AN AREA OF MUCAPE OF 2500-3000J/KG WILL MOVE ACROSS THE AREA AROUND 12Z REACHING NORTHERN LAKE MICHIGAN BY NOON. A 45 KNOT 850MB JET WILL BE MAKING A STRONG CYCLONIC SHIFT ACROSS THE FORECAST AREA AROUND 12Z. THIS SHIFT WILL MOVE INTO NORTHERN LAKE MICHIGAN BY 18Z. AN 80+ KNOTS UPPER LEVEL JET MAX WILL SHIFT FROM CENTRAL ONTARIO INTO NORTHERN LAKE SUPERIOR BY THIS AFTERNOON. THE STRONGEST 850-500MB Q-VECTOR CONVERGENCE WILL BE PASSING OVER THE FORECAST AREA THIS MORNING. DEEP LEVEL BULK SHEAR WILL BE 35 TO 50 KNOTS OVER LAKE SUPERIOR THIS MORNING...THE BULK SHEAR OF 40 TO 50 KNOTS WILL CONTINUE OVER THE ENTIRE AREA THIS AFTERNOON. THUS CONDITIONS LOOK FAVORABLE FOR THUNDERSTORM DEVELOPING INTO SEVERE THIS MORNING. SOUTHWEST FLOW AHEAD OF THE COLD FRONT WILL PRODUCE DEW POINTS INTO THE UPPER 60S AND LOW 70S ACROSS THE FORECAST AREA. THEREFORE...IT LOOKS LIKE THE GREATEST POTENTIAL FOR THUNDERSTORMS WILL BE BETWEEN 10Z AND 16Z TODAY. DRY AIR WILL ADVECT INTO THE AREA BEHIND THE COLD FRONT WHICH SHOULD START TO STABLIZE THE AIR MASS. TRAJECTORY FORECAST PLOTS CONTINUE TO DRAW WARM AIR OUT OF MINNESOTA AND WESTERN ONTARIO TO THE FORECAST AREA. GUIDANCE STILL SUGGEST WARM AIR ADVECTION BEFORE THE FROPA. CLOUD COVER WITH THE APPROACHING SHORTWAVES WILL HELP HOLD THE TEMPERATURES DOWN. THUS EXPECTED TEMPERATURES IN THE 80S TO AROUND 90. THE SHORTWAVE WILL SWEEP INTO LOWER MICHIGAN...WHILE ANOTHER WEAKER SYSTEM WILL SLIDE INTO THE U.P. TONIGHT. THE SURFACE RIDGE WILL SLIDE OVER THE FORECAST AREA. STRONG 850-500MB Q-VECTOR WILL DOMINATE THE AIR MASS. THE COLD FRONT WILL CONTINUE TO TRACK INTO THE OHIO RIVER VALLEY. DRY AIR ADVECTION BEHIND THE COLD FRONT WILL LOWER THE SURFACE DEW POINTS INTO THE LOW 50S. THE UPPER LEVEL JET MAX WILL SLIDE ACROSS THE FORECAST AREA. THIS WILL ADD TO THE INSTABILITY...HOWEVER...THE DRY AIR AND COOLER TEMPERATURES AT THE SURFACE WILL LIMIT PRECIPITATION POTENTIAL. THE STRONG Q-VECTOR DIVERGENCE AND SURFACE RIDGE WILL CONTINUE TO DOMINATE THE AIR MASS OVER THE UPPER GREAT LAKES ON TUESDAY. THUS WILL KEEP MAINLY DRY CONDITIONS. ANOTHER WEAK SHORTWAVE WILL RACE ACROSS THE FORECAST AREA TUESDAY NIGHT. THE SURFACE HIGH WILL RELOCATE OVER THE LOWER GREAT LAKES ALLOWING A LOW DEVELOPING OVER SOUTH CENTRAL CANADA TO SHIFT INTO EAST CENTRAL MANITOBA...WHILE DRAGGING A COLD FRONT INTO NORTHWEST MINNESOTA. THE NAM/GFS/ENSEMBLE SOLUTIONS SUGGEST PUSHING BACK THE START OF THE PRECIPITATION OVER THE FORECAST AREA BY 6 HOURS. DRY AIR WILL REMAIN IN PLACE 'TIL 12Z WED. THUS PLAN TO PUSH BACK THE ONSET OF SHOWERS AND THUNDERSTORMS. A COUPLE OF WEAK SHORTWAVES WILL TRAVERSE THE FORECAST AREA ON WEDNESDAY. THE SURFACE LOW WILL MOVE TO NORTH CENTRAL ONTARIO... PULLING THE COLD FRONT INTO THE ARROWHEAD OF MINNESOTA. THE FRONT WILL DIRECT GULF MOISTURE INTO THE UPPER GREAT LAKES REGION. 305K ISENTROPIC ANALYSIS SHOWING STRONG ASCENT OVER THE FORECAST AHEAD OF THE FRONT. PLAN TO BUMP UP THE POPS A LITTLE. AS THE SHORTWAVES DEPART THE FORECAST AREA WEDNESDAY NIGHT...A DEEPER SHORTWAVE WILL ENTER INTO THE WESTERN U.P. THE COLD FRONT WILL SWEEP THROUGH THE FORECAST AREA REACHING THE NORTHERN LAKE MICHIGAN SHORE BY 12Z THURSDAY. ISENTROPIC ANALYSIS SHOWING STRONG ASCENT AHEAD OF THE FRONT. DEEP MOISTURE WILL ALSO FEED MORE SHOWERS AND THUNDERSTORMS. THERE MAY BE A SHORT BREAK IN THE SHOWERS AROUND SUNRISE ON THURSDAY BEFORE THE DEEPER SHORTWAVE AND ASSOCIATED MOISTURE FIELD PASS OVER THE AREA GENERATING MORE SHOWERS AND THUNDERSTORMS. THE SHORTWAVE WILL SWEEP RAPIDLY THROUGH THE AREA AND THUS WILL ALLOW DRIER AIR TO ADVECT INTO AREA ON THURSDAY. THUS WILL END THE PRECIPITATION BY 00Z FRIDAY. THE SURFACE RIDGE WILL DOMINATE THE AREA THROUGH FRIDAY NIGHT. ANOTHER SYSTEM WILL ENTER THE REGION ON SUNDAY. && .MQT...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DLG mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ABERDEEN SD 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. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ TT/DH sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 334 AM MDT MON JUL 17 2006 .SHORT TERM... (TODAY AND TONIGHT) ...CONTINUED HOT... CURRENTLY...QUIET NIGHT OVER THE CWA WITH ONLY SOME CLOUDS IN THE MOUNTAINS. ACCORDING TO KCYS RADAR...COLD FRONT IS IN NORTHEAST COLORADO...BUT WINDS ARE WEAK BEHIND THE FRONT WITH SPEEDS AT KSNY AND KIBM 10 KNOTS OR LESS. TODAY...SURFACE COLD FRONT WILL MOVE INTO NORTHEAST COLORADO AND MAKE IT INTO KIOWA COUNTY BY LATE MORNING. CURRENTLY...DEWPOINTS BEHIND THE FRONT ARE NOT IMPRESSIVE WITH VALUES IN THE MID 30S TO LOWER 40S IN WYOMING AND WESTERN NEBRASKA. AS FRONT MOVES SOUTHWARD...NAM/WRF HAS MORE MOIST NORTHEAST FLOW DEVELOPING ON THE PLAINS. 06 NAM/WRF HAS MORE MOISTURE THAN THE 00Z RUN. WRF INCREASES SURFACE DEWPOINTS DURING THE MORNING OVER WESTERN NEBRASKA AND KANSAS IN THE NORTHEAST FLOW JUST BEHIND THE FRONT. THE MOISTURE INCREASE MAY BE THE RESULT OF EVAPOTRANSPIRATION...AND I HAVE CONCERNS ABOUT HOW WELL THE WRF MODELS THIS. RUC13 ONLY HAS DEWPOINTS IN THE 40S BEHIND THE FRONT WHICH IS MORE REASONABLE GIVEN THE AIR UPSTREAM. I HAVE A MODEST INCREASE IN MOISTURE BEHIND THE FRONT. THE 00Z RUNS SHOWED SOME CAPES AROUND 1500 J/KG...BUT IT WAS CAPPED WITH CIN AROUND 100. WITH THE RIDGE AND WARM TEMPERATURES ALOFT...AIRMASS WOULD TEND TO BE CAPPED. I DID PUT SOME MODEST POPS OVER PORTIONS OF THE PLAINS FOR THE POSSIBLE CONVECTIVE CELL THAT MAY DEVELOP. I ONLY COOLED TEMPERATURES A COUPLE OF DEGREES AS AIR ALOFT REMAINS WARM AND DRY. OVER THE MOUNTAINS...THE VERY GRADUAL INCREASE IN MOISTURE IN THE RIDGE WILL CONTINUE AND CURRENT FORECAST LOOKED GOOD. TONIGHT...ANY CONVECTION WILL END IN THE EVENING. 06Z RUC AND WRF MAINTAIN THE EASTERLY FLOW LONGER THAN IN THE 00Z RUNS. ONCE THE SHALLOWER COOLER AIR MAKES IT ONTO THE PLAINS...IT WILL NOT MIX OUT/MOVE NORTH UNTIL SOMETIME ON TUESDAY MORNING. CURRENT FORECAST WAS NOT CHANGED MUCH. --PGW-- .LONG TERM... (TUESDAY THROUGH SUNDAY) TUESDAY THROUGH THURSDAY...NOT A LOT OF ADJUSTING NECESSARY TO THE ONGOING FORECAST PACKAGE. NAM...GFS AND ECMWF MODELS INDICATE THAT THE RATHER BROAD RIDGE OF HIGH PRESSURE OVER THE S AND SW U.S. WILL PERSIST...FIRST SLIPPING TO THE EAST...THEN BACK TO THE WEST. MODELS AGREE ON SNEAKING MOISTURE UP ACROSS THE DESERT SW INTO THE WESTERN HALF OF COLORADO...BUT BY WED THIS MOISTURE LOOKS TO BECOME DEEPER. MUCH OF THE CONVECTION SHOULD STILL BE CONFINED TO THE HIGHER TERRAIN AND CONTDVD...BUT THERE IS A BETTER CHANCE FOR THESE STORMS TO BE WET BY MID-WEEK. HOT MAX TEMPS ARE EXPECTED TO CONTINUE. AN UPPER TROUGH FORMS AND MOVES ACROSS THE PAC NW ON THU...WHICH WILL BECOME A PLAYER FOR CO FOR THE WEEKEND. FRIDAY THROUGH SUNDAY...BY FRIDAY BOTH GFS AND ECMWF MODELS FORECAST AN UPPER DISTURBANCE TO DROP DOWN THE N ROCKIES...WITH ALL INDICATIONS OF AN INCREASE IN POPS AND CLOUD COVER FOR THE ENTIRE CWA...AS WELL AS SLIGHTLY COOLER TEMPS AS THE ASSOCIATED SFC FRONT MOVES THROUGH. MAX TEMPS OVER THE WEEKEND COULD BE AS MUCH AS 10 DEGREES COOLER. DID NOT CHANGE A LOT IN THE FORECAST GRIDS SINCE THIS IS THE PREVAILING TREND. MOORE && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 06/27 co 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...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 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 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 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