AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 425 PM EDT FRI JUL 6 2001 PRECIP THROUGH SAT AFTN IS MAIN CONCERN. SHRTWV RIDGE AXIS RESIDES OVR UPR MI THIS AFTN...WITH VERY SHARP SHRTWV SLICING INTO WRN OT. ANOTHER SHRWV IS ALSO NOTED ENTERING MN ON THE NOSE OF H5 SPEED MAX. COUPLE OF STRONG JET STREAKS FOUND ON 12Z RAOBS/LATEST ACARS DATA...WITH ONE FM AB INTO MB AND THE OTHER VERY STRONG ONE (145KT) SHIFTING DUE SOUTH FM HUDSON BAY INTO LK ERIE. UPR MI IN BTWN AND IS NOT SUPPORTED BY EITHER JET. EVEN THOUGH PRIMARY SHRTWV IS WELL TO NORTH...A VERY DISTINCT SFC/H85 TROUGH RESIDES FM LOW OVR NRN MB SOUTH INTO ERN CO. AN INTENSE/MOIST H85 JET IS TRANSPORTING H85 T/TD OF OF 20C/14C JUST AHEAD OF THIS TROUGH AS FAR NORTH AS SRN SHORES OF LK WINNEPEG IN MB. RIBBON OF MOISTURE HOWEVER IS VERY NARROW AS MORNING SOUNDINGS FM GRB/INL ONLY SHOWED TD OF 2C/7C. OVR UPR MI STABLE AIR STILL THE CASE WITH HIGH PRESSURE RIDGE FM SRN LOWER MI INTO OHIO VALLEY. VIS SAT SHOWS JUST SOME CI/AC OVR WRN 2/3 OF FA WITH LGT SHRA ENTERING WRN FA WITH CU BEGINNING TO DEVELOP ALONG TROUGH IN NRN MN (WHERE SFC TD GREATER THAN 70F ARE POOLING ATTM). TONIGHT...SFC TROUGH MOVES TOWARD FA AND APPROACHES IWD BY 03Z...MQT BY 06Z...AND AT ERY BY 09Z. THIS TIMING IS SLIGHTLY SLOWER THAN PREVIOUS RUNS AS SHOWN BY DPROG/DT OF NGM/ETA MSLP. IN ABOUT A 200 MILE RANGE AHEAD OF FRONT SHRA HAVE FORMED IN WAA ZONE OVR ERN MN PER ETA 305-310K (H85-H75) ALTHOUGH LGTNG IS SPARSE DUE TO LIMITED INSTABILITY AS ONLY 5.5-6.0C/KM LAPSE RATES ARE PRESENT FM H85-H5 PER ETA AND RUC INCREASING THERE IS SOME PRESENT IN NERN MN AS SFC DWPTS AND RESULTING INSTABILITY IS CREEPING INTO NRN MN AHEAD OF APPROACHING TROUGH. LATEST RUC BRINGS FIRST WAVE OF PRECIP ACROSS FA (ASSOCIATED WITH MN SHRTWV...H85-H5 QVECTOR CONVERGENCE AND H85-H3 DIFF DIVERGENCE)...THEN DEVELOPS ANOTHER BATCH OF PRECIP AS PRIMARY TROUGH CROSSES BEGINNING AROUND MIDNIGHT. 12Z MODELS DEVOTE FOCUS TO INITIAL DYNAMIC RIBBON...BUT ETA/AVN DO HINT VERY FAINTLY AT A SECONDARY SHOT OF QPF. THINK THAT WITH SUCH LOW-LEVEL DRY AIR OVERHEAD CNTRL/ERN FA TO BEGIN WITH (H85-H7 RH LESS THAN 40 PCT THRU 00Z) WILL DIMINISH SHRA INTENSITY/COVERAGE. IF A HEAVIER EVENT WAS TO OCCUR IT WOULD LIKELY BE OVRNIGHT AS THE MOIST TOUNGUE MENTIONED EARLIER MOVES THRU. POPS WILL GO FM LIKELY WEST...TO SCT CNTRL/EAST. WAA LEADING TO AN INCREASE IN MOISTURE AND INSTABILITY (SI/S NEARING -4C BY 06Z) COULD LEAD TO A FEW RUMBLES OF THUNDER. WITH STRONG SHEAR AND VERY GOOD LOW LEVEL THERMODYNAMICS A FEW STORMS MIGHT FLIRT WITH SVR POTENTIAL...BUT ATTM BELIEVE THIS WILL BE FARTHER UPSTREAM IN AREA OF BETTER INITIAL INSTABILITY. SATURDAY...BY 12Z FRONT BECOMES FRATURED AS PORTION CLOSEST TO PARENT SHRTWV AND THUS THE SEGMENT THAT IS DRIVEN BY STRONGER WINDS ALOFT BEGINS TO OUTRACE THE PORTION FARTHER SOUTH. THIS WILL PRODUCE A FRONT RACING ACROSS CNTRL OT WITH AN INCREASINGLY STATIONARY FNT FM CNTRL PLAINS INTO ERN UPR MI. MAIN BATCH OF SHRA SHOULD EXIT FA SOMETIME AROUND 12Z BUT BOUNDARY THEN LOOKS LIKE IT STALLS ACROSS ERN FA. WITH WEAK WIND IN VCTY OF TROUGH LEADING ITSELF TO POSSIBLE LAKE BREEZE CONVERGENCE AND SBCAPES AROUND 300J/KG COULD BE SOME SHRA/TSRA TRY TO REDEVELOP IN THE AFTN OVR ERN FA. WL INCLUDE A SMALL POP FOR THIS AND ANY LEFTOVR PRECIP IN THE MORNING. OTHERWISE TEMPS WILL RISE TO AROUND 80F INLAND AS H85 TEMPS RISE TO 14C. A BIT COOLER ALONG LK SUPERIOR WEST AND CENTRAL WITH LINGERING CLOUDS AND ANY PRECIP HOLDING DOWN TEMPS A NUDGE IN THE EAST. SUNDAY...HIGH PRESSURE OVERHEAD WITH PLENTY OF SUNSHINE AS WAA IS UNDERWAY. LACK OF COOL AIR IN LOWER LEVELS SHOULD PREVENT MUCH CU. H85 TEMPS SURGE TO 14C-16C BY EVENING...WHICH WILL YIELD TEMPS IN THE LOW-MID 80S ACROSS ALL OF FA EXCEPT ALONG LK MI WHERE MORE SRLY COMPONENT (H95 WINDS FALLING AOB 15KT IN AFTN) WILL PRODUCE COOLER TEMPS ALONG LK MI. EXTENDED FORECAST...GOOD RUN-TO-RUN CONTINUITY CONTINUES FOR MON-FRI FCST PERIOD WITH MON APPEARING TO HAVE BEST CHANCE FOR RAIN AS WEAK SFC TROUGH PER AVN/UKMET/ECMWF/MRF/ETAX (ALTHOUGH PRIMARY DYNAMICS REMAIN WELL TO NORTH OVR OT). IN BIG PICTURE...ZONAL PAC FLW CONTINUES INTO WRN LAKES REGION THRU WED...WITH A SLIGHT DIGGING OF ERN TROUGH BY THU PUTTING UPR MI INTO MORE NW FLW ALOFT. ATTM OPERATIONAL CANADIAN AND ASSOCIATED ENSEMBLES ARE MOST DIGGY WITH TROUGH AS THEY BRING SOUTHERN FRINGE OF WESTERLIES FM SW OT ACROSS UPR MI INTO NEW ENGLAND. THE MRF AND MRF ENSEMBLES IN ADDITION TO ECMWF/AVN/UKMET ALL ARE A BIT FARTHER NORTH...SO AS A COMPROMISE WILL TRIM TEMPS DOWN (NOW SLATED TO BE RIGHT AROUND CLIMATOLOGY) TO ACCOUNT FOR POSSIBILITY OF MORE NW FLW. HIGH PRESSURE WILL MOVE OVRHEAD FOR MID WEEK BUT MRF SHOWS SFC TROUGH CROSSING INTO AREA FRI AS SHRTWV TROUGH MOVES ACROSS CNTRL CANADA. CANADIAN ENSEMBLES ARE NOT AS SHARP WITH SHRTWV TROUGH WHILE MRF MEMBERS SEEM TO FAVOR SAT AS BETTER DAY FOR PRECIP WITH SLOWER SOLN THAN OPERATIONAL MODEL (WHICH MAKES SENSE WITH SUCH STRONG RIDGE IN PLACE OVR WRN CONUS)...SO ATTM WILL GO WITH DRY FCST TUE THRU FRI. COORD WITH APX AND GRB...THANKS. .MQT...NONE. JLA mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1150 AM EDT FRI JUL 6 2001 MAIN FCST CONCERNS ARE TIMING OF SHRA/TSRA LATER THIS AFTERNOON ALONG WITH ANY SVR POTENTIAL. WV IMAGERY AND RUC ANALYSIS INDICATED TROF OVER ERN NOAM...A RDG OVER THE SRN HI PLAINS. TOWARD HUDSON BAY. A SHRTWV AND 100 KT H3 JET INTO SASK..MANITOBA WAS FLATTENING THE RDG AS IT PROGRESSED TOWARD WRN ONTARIO. AT THE SFC...TROF EXTENDED FROM NRN MB INTO ERN DAKOTAS SLIGHTLY AHEAD OF LLVL THETA-E RDG EXTENDING FROM THE SRN PLAINS INTO THE CTNRL DAKOTAS WITH TD FROM THE MID 40S F OVER UPR MI AND NRN WI TO MID 50S OVER ERN MN AND 60S TO NEAR 70 TO THE WEST. NODAK MCS...SUPPORTED BY 35-40 KT LLJ IN ADVANCE OF THE TROF...HAS FALLEN APART AS IT MOVED INTO MORE STABLE AIR OVER CNTRL MN WITH LIGHTNING PLOT SHOWING MORE SUBSTANTIAL CONVECTION CONFINED TO FAR WRN MN. ONLY -SHRA WERE LEFT OVER NRN MN. IR/VIS LOOP SHOWED THICKENING CLOUDS OVER WRN UPR MI WITH REMNANTS OF CONVECTION AND INCREASING 305K-315K ISENTROPIC LIFT...PER 12Z RUC/ETA. WHILE INCREASING WAA/ISENTROPIC LIFT AHEAD OF THE TROF SHOULD BE ENOUGH TO SUSTAIN SOME -SHRA INTO UPR MI LATER THIS AFTERNOON...CHANCES FOR SIGNIFICANT TSRA ARE DWINDLING. EXPECT LITTLE IN THE WAY OF UPR LVL SUPPORT WITH WEAK UPSTREAM SHRTWV FURTHER WEAKENING AS MOVES THROUGH THE RDG. AREA IS ALSO CLOSER TO UNFAVORABLE RIGHT EXIT REGION OF H3 JET OVER SRN CANADA. ANY CONVECTION THAT DEVELOPS WILL BE ELEVATED AS SIGNIFICANT SBCAPES LAG TO THE WEST OVER MN. RUC/ETA FCST SNDGS SUGGEST MUCAPE OF ONLY ABOUT 400 J/KG (WITH TD NEAR 14C...LIFT FROM 825 MB) INTO WRN UPR MI. LLVL AND DEEP LYR SHEAR (45 KT SFC-6KM) REMAINS SUBSTANTIAL SO THAT LIMITED INSTABILITY MAY BE ENOUGH FOR SOME ISOLD STRONGER STORMS WEST. HOWEVER...AGREE WITH SPC IN TRIMMING BACK SLGT RISK AREA TO AREA SW OF UPR MI...NEAR MORE FAVORABLE INSTABILITY. ACCORDINGLY...TSRA WORDING HAS BEEN DOWNPLAYED. WITH UPSTREAM -SHRA CONTINUING TO DWINDLE...AND SOME REDEVELOPMENT EXPECTED LATER THIS AFTERNOON...TIMING OF ONSET LOOKS SIMILAR TO GOING FCST...19Z-23Z WEST HLF AND AFT 00Z FOR THE EAST PORTION OF THE CWA. WITH THICKENING CLOUDS...GOING TEMP FCST LOOKS ON TRACK WITH MAX READINGS INTO THE MID 70S F. .MQT...NONE. JLB mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1119 AM EDT FRI JUL 6 2001 SFC HIGH PRES REMAINS CENTERED ACROSS THE SRN GREAT LAKES AND THE OHIO VALLEY LATE THIS MORNING...PRODUCING SKC ACROSS ALL OF LOWER MI AND ERN UPR MI. CONVECTION ACROSS MN WHICH DEVELOPED JUST AHEAD OF COLD FRONT NOW EXTENDING N/S THRU THE PLAINS IS GRADUALLY DIMINISHING IN INTENSITY AS NOCTURNAL JET WEAKENS. LATEST RUC HAS BACKED OFF ON ARRIVAL OF HIGH CLOUDS INTO WRN SECTIONS OF THE CWA UNTIL LATE IN THE AFTERNOON. THIS TREND MATCHES WELL WITH LATEST IR AND VSBL SATELLITE TRENDS. ALSO...CU SCHEME AND OBSERVED/MODEL SOUNDINGS SUGGEST LITTLE IN THE WAY OF CU DEVELOPMENT THIS AFTERNOON. WILL GO WITH SUNNY SKIES FOR THE AFTERNOON...WITH SOME INCREASE IN HIGH CLOUDS LATE FOR ERN UPR AND NW/N CENTRAL LOWER MI ZONES. 925 MB WINDS INCREASE TO 15 TO 20 MPH IN THE AFTERNOON... AND WILL LIKELY PRECLUDE ANY LAKE BREEZE DEVELOPMENT. .APX...NONE. EME mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 1050 AM EDT FRI JUL 6 2001 FRONTAL BOUNDARY MOVING FASTER THAN EXPECTED WITH NRLY WIND SHIFT OVER ENTIRE MHX MAINLAND CWA AT 14Z. LATEST RUC40 AND INCOMING MESOETA CONCUR WITH FRONT S OF AREA BY 00Z. AIR MASS BOUNDARY WITH HIGHER DEW POINTS WILL LIKELY LAG OVER SRN SECTIONS INTO AFTN AND PROVIDE FOCUS FOR SCT TSTMS WITH STRONG SHRT WV MOVING THRU FROM NW...AND ISOLD SVR STILL POSSIBLE. WILL KEEP 40% POPS FOR SRN ZONES BUT DROP POPS N. TEMP FCST OK EXCEPT WILL DIFFERENTIATE BETWEEN N AND S ON OUTER BANKS WITH NRN SECTIONS COOLER DUE TO N-NE WIND. CWF: WITH FASTER FRONTAL MOVEMENT EXPECTED...WILL HAVE TO ADJUST WIND FCST ACCORDINGLY...MAINLY FOR SRN WATERS. LATEST OBS INDICATE SEAS BELOW 5 FEET SO WILL DROP SCEC WORDING FOR NRN WATERS. S FACING BEACHES STILL SEEING EFFECTS FROM SVRL DAYS OF SW FLOW AND WILL CONTINUE INCREASED THREAT OF RIP CURRENTS. .MHX...NONE JBM nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORMAN OK 928 PM CDT FRI JUL 6 2001 00Z ANALYSIS VERIFIES 12Z COMPUTER MODEL FORECASTS OF BUILDING MID/UPPER RIDGE EASTWARD INTO THE FORECAST AREA. 850/700 MB THERMAL RIDGE HAS ALSO PIVOTED TO BE MORE PARALLEL WITH THE MEAN LAYER WIND WHICH SHOULD ALLOW THERMAL ADVECTION TO BE LESS OF A CONCERN COMPARED TO THIS TIME YESTERDAY. OVERALL...SUBSIDENCE SHOULD RULE OVERNIGHT WITH ONLY LITTLE OR NO CHANGE EXPECTED TO THE FORECAST. WILL CONTINUE TO MONITOR TEMPERATURE/WIND TRENDS ACROSS NORTHWEST OKLAHOMA WHERE THE 18Z ETA/LATEST RUC SHOW A 30 TO 40 KNOT LOW LEVEL JET FORMING 06-12Z. BELIEVE FORECAST HAS THIS CONCERN WELL ADDRESSED SO SEE NO REASON FOR CHANGES. .OUN... OK...NONE. TX...NONE. JAMES ok AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 1044 AM EDT FRI JUL 6 2001 LATEST RUC TIMING SHOWS STRONGEST 850 TO 500 MB DPVA AFFECTING NE PART OF FORECAST AREA CIRCA 18Z TO 20Z. MORNING SOUNDINGS SHOW CONSIDERABLE DRY AIR THROUGHOUT THE PROFILE...BUT LOW LEVEL DEWPOINTS HAVE BEEN RELUCTANT TO FALL BEHIND SLOWING FRONTAL SYSTEM. CURRENT FORECAST HAS THIS ADEQUATELY CAPTURED WITH CHC POPS FOR NE SECTIONS. RUC GIVES SOME REASON FOR PAUSE WITH WEAK SFC DEVELOPMENT ALONG BOUNDARY THIS AFTERNOON OVER THE SC UPSTATE. BUT WITH THE BEST DYNAMICS EARLY IN THE AFTERNOON AND RELATIVELY DRY SOUNDINGS...WILL KEEP SILENT 20 POPS IN THE FORECAST SW SECTIONS. CLT IS OFF TO A WARM START AND LOW LEVEL THICKNESSES SUPPORT MAXES AROUND 90. WILL BUMP TEMPS UP A NOTCH IN THAT AREA. WILL ADJUST WINDS FOR GENERALLY LIGHT AND VARIABLE FLOW THROUGHOUT THE AFTERNOON OUTSIDE THE MTNS. FCSTID = 33 GSP 91 66 93 70 / 20 20 10 0 AND 92 66 93 70 / 20 20 10 0 CLT 90 66 92 69 / 30 30 10 0 HKY 88 62 90 66 / 30 30 10 0 AVL 86 60 88 64 / 20 20 10 0 .GSP... GA...NONE. NC...NONE. SC...NONE. HG sc AREA FORECAST DISCUSSION FOR CENTRAL/NORTHCENTRAL AND NORTHEAST SOUTH DAKOTA AND WEST CENTRAL MINNESOTA NATIONAL WEATHER SERVICE ABERDEEN SD 850 PM CDT FRI JUL 6 2001 SFC FRONT HAS CLEARED ALL OF ERN CWA...SO TSRA NO LONGER THREAT. WILL REMOVE MENTION OF TSRA FROM ERN ZONES. ALSO...DWPTS ARE SLOW TO RESPOND TO DRYING. ACTIVITY IN ERN WY/FAR WRN SD HOLDING TOGETHER. STILL ANTICIPATE CONVECTION TO TURN MORE SE AS THE NIGHT WEARS ON. CURRENT SCT POPS IN KPIR GROUP...AND THEY LOOK WARRANTED. WITH CENTER OF SFC HIGH BEGINNING TO MOVE INTO CENTRAL/S-CENTRAL ND...WILL REMOVE MENTION OF TSRA FROM N-CENTRAL SD. ALSO...UPPED LOWS FOR KPIR AND KMBG A NOTCH...BASED ON NEW RUC/LAMP AND 18Z MESO-ETA GUIDANCE. UPDATED ZONES ALREADY SENT. .ABR...NONE. HINTZ sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD, VA 1009 AM EDT FRI JUL 6 2001 FNT S OF THE CWA NOW. STILL FAIRLY STRG TROF WL PASS BY OVERHEAD THIS AFTN. THIS WL HELP KEEP JUST SOME SC CLDS ARND THE AREA. MAINLY OVR THE SE PART OF THE AREA. SKIES WL BE MSTLY SUNNY THRU THE AFTN. TEMPS LOOKING AT MRNG SOUNDINGS AND 12Z RUC WOULD INDICATE LOW TO MID 80S. THIS LEADS TO A FCST LIKE CURRENT ZONES SO NO CHGS PLANNED FCSTID = 92 SBY 84 59 87 65 / 0 0 10 30 OXB 80 60 81 68 / 0 0 10 30 ECG 81 65 85 70 / 10 0 10 10 ORF 81 65 85 70 / 10 0 10 10 PHF 82 61 85 67 / 10 0 10 30 AKQ 85 60 88 68 / 10 0 10 30 RIC 85 60 88 68 / 10 0 10 30 FVX 85 60 88 68 / 0 0 10 30 .AKQ... MD...NONE. NC...NONE. VA...NONE. BILLET va AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHEYENNE WY 210 PM MDT FRI JUL 6 2001 LOOKS LIKE 16 UTC UPDATE OF DAY ONE OUTLOOK HAD RIGHT IDEA CUTTING OFF RISK SEVERE ALONG NEB/CO BORDER. SATELLITE/RADAR LOOPS SHOW STORMS FIRING OVER NORTH-CENTRAL CO...THEN LIFTING NORTH-NORTHEAST. WILL TAKE A LONG TIME FOR STORMS TO GET AS FAR EAST AS SNY. COMPUTED LI/S LOWEST OVER CENTRAL PANHANDLE ATTM THO. IMPULSE FIRING CO STORMS APPARENTLY WHAT MODELS MOVE TO CENTRAL PANHANLE BY 06 UTC/MIDNIGHT AND INTENSIFY. 18 UTC RUC40 MISSING NORTH-CENTRAL CO QPF BUT 18 UTC MESO-ETA LOOKS BETTER. BELIEVE IT SPREADS IT TOO FAR TO EAST IN FAR SOUTH PANHANDLE DURING AFTERNOON HRS. 12 UTC RUN OF NCAR MM5 HAD 1.0 INCH QPF BULLSEYE EAST OF BFF THIS EVENING. WILL SEE IF THIS VERIFIES. NEXT BIG QPF POSSIBILITY NOT UNTIL SAT EVENING...ACCORDING TO MODELS. AVN HAS ANOTHER STRONG VORTICITY CENTER OVER CENTRAL PANHANDLE AT 42 HRS/MIDNIGHT SAT. ETA WEAKER AND SLIGHTLY FASTER WITH IMPULSE FROM NORTH OF VTN TO SOUTHEAST CORNER WY. AVN HAS 0.63 INCH BULLSEYE NEAR BFF AT 42 HRS WHILE ETA HAS 0.42 JUST EAST OF CYS. POPS DROP TO MORE SEASONAL VALUES FOR SUN AFTERNOON AS MEAN RIDGE EXTENDS FROM CENTRAL GREAT PLAINS NORTHWESTWARD ALONG NORTHERN ROCKIES. QUITE WARM TEMPS U.F.N. .EXTENDED DISCUSSION... STRONG UPPER RIDGE OF HIGH PRESSURE WILL REMAIN CENTERED OVER THE SOUTHERN ROCKIES/PLAINS THROUGH PERIOD. MONSOONAL MOISTURE WILL CONTINUE TO FLOW FROM OLD MEXICO AND THE DESERT SOUTHWEST INTO THE INTER-MOUNTAIN REGION AND PACIFIC NORTHWEST. TEMPERATURES ACROSS THE FORECAST AREA WILL REMAIN ABOUT THE SAME FROM DAY TO DAY...AS NO MAJOR FRONTS ARE PROGGED TO PASS THROUGH THE AREA AND THICKNESS VALUES DON'T CHANGE MUCH. WITH THE HOT TEMPERATURES AND MONSOONAL MOISTURE...A CHANCE OF AFTERNOON THUNDERSTORMS CAN BE EXPECTED EACH DAY ACROSS THE AREA THROUGH THE PERIOD. .CYS... WY...NONE. NE...NONE. COX/KMD wy WESTERN COLORADO & EASTERN UTAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 315 AM MDT SAT JUL 7 2001 SHORT WAVE APPROACHING SOUTHEAST UTAH THIS MORNING WITH RADAR IMAGERY SHOWING A GRADUAL INCREASE IN ECHOES. NOTHING SIGNIFICANT YET.. BUT INDICATIVE OF THE INCREASE OF MOISTURE EXPECTED TODAY. MESOETA MODEL SHOWS MID LEVEL WAVE MOVES NORTH DURING THE DAY.. REACHING THE SOUTHERN ZONES THIS MORNING.. NEAR KGJT AND MOAB AROUND NOON.. THEN THE NORTHERN ZONES THIS AFTERNOON. PRECIPITABLE WATER IN THE LOWER VALLEYS EXCEEDS ONE INCH WITH SPECIFIC HUMIDITIES AT 700 MB AROUND 8 G/KG. SUFFICIENT MOISTURE TO PRODUCE SCATTERED AREAS OF WETTING RAINS IN THE LOWER VALLEYS.. AND LOCALIZED HEAVY SHOWERS OVER THE HIGHER TERRAIN. THE DEEPEST MOISTURE STAYS WEST OF THE FORECAST AREA.. SO THE POTENTIAL OF MODERATE SHOWERS DECREASES FARTHER EAST WITHIN THE COUNTY WARNING AREA. GRIDDED RELATIVE HUMIDITY FIELDS ONLY SHOW MODEST AMOUNT OF MOISTURE OVER THE EASTERN PART OF THE SAN JUANS. SURROUNDING UPPER AIR DATA AND SOUNDER SATELLITE DATA SUPPORT THESE TRENDS.. AND WILL ESSENTIALLY BASE FORECASTS ON THE SHORT TERM RUC AND MESOETA MODELS. MEAN WIND FLOW AROUND 20 KNOTS KEEP STORMS MOVING ALONG AND ANY MODERATE TO HEAVY RAIN SHOWERS WILL NOT LAST TOO LONG AT ANY GIVEN SPOT. EXTENSIVE CLOUD COVER WITH COOLING SHOWERS WILL BRING AN END TO THE CURRENT HEAT WAVE.. AND STOP THE STRING OF 100 PLUS DAYS AT KGJT. ONCE SHORT WAVE PASSES.. AIR MASS WILL NOT BE AS MOIST ON SUNDAY AS TODAY.. AND MODELS INDICATE A SUBSIDENCE LAYER ABOVE 500 MB THAT WILL IMPEDE CONVECTION. BUT RELATIVE MOIST LOWER LEVELS AND STRONG SURFACE HEATING SHOULD BE SUFFICIENT FOR DIURNAL SHOWERS AND THUNDER THAT FAVOR THE HIGHER TERRAIN. A RETURN TO WHAT HAS BEEN OBSERVED THAT LAST FEW DAYS.. ISOLATED VALLEY ACTIVITY BUT SCATTERED STORMS IN THE MOUNTAINS. EXCEPT STORMS WILL NOT BE AS DRY AS THEY HAVE BEEN. FRISBIE WESTERN COLORADO AND EASTERN UTAH EMERGENCY MANAGERS SHOULD MAINTAIN A NORMAL LEVEL OF WEATHER AWARENESS TODAY. .GJT...NONE. co EAST CENTRAL FLORIDA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MELBOURNE FL 249 AM EDT SAT JUL 7 2001 CURRENTLY...WATER VAPOR IMAGERY AND RUC H5-H3 STREAMLINES SHOW UPPER L/W TROUGH EXITING THE ERN SEABOARD. DECENT UPPER DRYING NOTED ON WATER VAPOR ACROSS FL PANHANDLE AND S GA THAT SHOULD CONTINUE TO MOVE TWD NRN ZONES BY THIS AFTN. NOT AS MUCH HIGH CLOUDINESS ARND AS AT THIS TIME LAST NIGHT AND SHOULD CONTINUE TO THIN BRINGING A MOSTLY SUNNY START TO THE DAY. TODAY...S/W OFF THE NC COAST CONTINUES TO DROP SE WITHIN THE L/W TROUGH BRINGING WHATS LEFT OF THE UPR TROUGH AXIS TWD S FL. ETA/NGM BOTH SHOW AREA OF NVA/SUBSIDENCE MOVING INTO NRN ZONES THIS AFTN WHICH WILL BRING DRYING ABOVE H7 TO NRN AREAS THIS AFTN. PWAT PROGS STILL ARND 1.8 ON THE BIG THREE MODELS FOR THIS AFTN...A BIT HIGHER THAN THAN YDAYS 00Z RUNS. SFC SYNOPTIC FLOW WILL BE LGT THIS MORNING AND THEN BECOME E/SE 5-10 MPH THIS AFTN. STEERING FLOW THIS AFTN WILL BE FROM THE N TO NE IN THE 5-10 KT RANGE SO SEA BRZ CONVECTION SHOULD MOVE SLOWLY INLAND...A SWITCH FROM THE PAST FEW DAYS WHEN STORMS HAVE MOVED BACK TWD THE E CST IN THE LATE AFTN. MODEL POPS IN THE 30-40 RANGE. UNDERCUTTING LOOKS GOOD FOR NRN CSTL...WHERE ACTIVITY SHOULD MOVE INLAND AND UPPER DRYING MOVES IN THIS AFTN. 40 RANGE FOR SRN INTERIOR SHOULD DO IT FOR BEST COVERAGE. TONIGHT...SLGT CHANCE EVE POPS ACROSS THE INTERIOR...OTHERWISE QUIET NIGHT WITH LOWS 70-75. SUNDAY...MODEL POPS CONVERGING AROUND 30 CWA-WIDE WHICH IS THE GOING FORECAST. FORECAST AREA REMAINS IN AREA OF INCREASING NORTHERLY FLOW ALOFT WITH DRY AIR ABOVE H7. NGM/ETA HINT A WEAK IMPULSE MOVING DOWN BACK SIDE OF TROUGH SUN AFTN INTO NRN ZONES WHICH MAY BE ENOUGH TO TRIGGER SOME STORMS OTHER THAN SCT SEA BRZ CONVECTION WHICH SHOULD FOCUS ALONG CSTL COUNTIES AND PROPOGATE SOUTHWARD. WEAK SW SFC FLOW AND SUFFICIENT LOW LVL MOISTURE WILL GENERATE SOME SCT SEA BRZ TSTMS AS WELL. WILL KEEP 30 POP WITH THE AMOUNT OF DRYING IN THE H7-H3 LYR. SUN NGT/MON...FCST GETS MORE INTERESTING WITH BOTH ETA/NGM FCSTING NEXT S/W AND ASSOC VORT MAX ACROSS SC/GA SUN EVE. ETA TRACKS FEATURE INTO NE FL SUN NGT WHILE AVN MOVES VORT SE OFF THE COAST. ON MON...WITHOUT THE INFLUENCE OF THE UPR S/W OR NOT...DEVELOPING SW LOW LVL FLOW WILL ALLOW SEA BRZ CONVECTION TO AGAIN BE CONCENTRATED ON THE E SIDE OF THE PENINSULA. WILL LEAN TWD HIGHER END OF SCT RANGE FOR MON AFTN...WHICH IS ALSO WELL COVERED IN THE FCST. EXTENDED...A SERIES OF UPR S/W'S WILL TRACK TWD FL AND THE SE IN NW/N FLOW ALOFT. LOW LVL FLOW WILL REMAIN FROM THE SW WHICH IS ALSO FAVORABLE FOR CONVECTION TO BE FOCUSED ON THE E SIDE OF THE PENINSULA. HIGH SCT RANGE POPS IN EXTENDED LOOK GOOD. WILL TAKE A LOOK AT NEW MRF AND MAY MAKE A FEW MINOR TWEAKS. MARINE...WINDS GENERALLY ARND 10 KTS OR LESS THROUGH 60 HRS. WILL PICK UP WINDS TO SW 10-15 KTS ACROSS THE NRN LEG SUN NGT THOUGH AS PRES GRADIENT INCREASES A BIT. PRELIM... DAB BB 090/073 091/072 091 152-3 MCO BB 093/074 093/073 092 15323 MLB BB 089/074 090/074 091 153-3 .MLB...NONE. PUBLIC/MARINE...VOLKMER AVIATION/FIRE WX...GLITTO fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON, NC 150 AM EDT SAT JUL 7 2001 ADJACENT WFOS PLEASE NOTE: PARTS ARE ON EMERGENCY ORDER FOR THE KLTX RADAR...WHICH WAS APPARENTLY STRUCK BY LIGHTNING YDAY AFTERNOON. THE PARTS ARE DUE TO ARRIVE THIS MORNING...HOWEVER IT MAY TAKE A COUPLE DAYS TO MAKE THE REPAIRS. DISCUSSION...AS OF THE 05Z SFC ANALYSIS THE FRONT WAS SITUATED FROM JUST SE OF FRYING PAN SHOALS TO NEAR CHS WITH HIGH PRES ACROSS THE MID-ATLC REGION. RUC/ETA/AVN HAVE THE FRONT ACROSS CHS/S CWA TODAY ...WEAKENING W/ WEAK RETURN FLOW LATER TONIGHT. THE UPPER TROF AXIS IS NOW OFF THE COAST W/ A BAND OF SUBSIDENCE ACROSS THE ERN CAROLINAS MOVING E. LARGE MID/UPPER HIGH WAS FOUND ACROSS THE CENTRAL PLAINS...PLACING THE SERN US UNDER NWLY FLOW ALOFT. THIS FLOW WILL DIRECT HARD TO PINPOINT/TIME MID-LVL VORT MAXES TOWARD THE REGION THIS FORECAST CYCLE. ONE THAT HAS SHOWN CONTINUITY IS ON TAP FOR SUN NIGHT. FOR TODAY...EXPECT SUNNY TO MOSTLY SUNNY SKIES W/ SOME THIN CI POSSIBLY TO MOVE ACROSS LATER TODAY. THE AIRMASS HAS STABILIZED NICELY W/ THE BEST CAPE/LIFTED INDICES TO BE FOUND ALONG THE SAV RIVER...SO NIL POPS. SHOULD SEE AN INACTIVE SEA BREEZE DEVELOP TODAY GIVEN THE INSOLATION AND WEAK FLOW IN THE BLYR. MAY HAVE SOME PATCHY FOG DEVELOP UNDER MOSTLY CLEAR SKIES TONIGHT...AND GUIDANCE LOOKS REASONABLE WITH A SPREAD OF 65-70. ON SUN...RETURN FLOW IS UNDERWAY AHEAD OF THE NEXT SYSTEM DROPPING IN FROM THE NW. INSTABILITY RETURNS TO THE REGION AND COULD SEE SHRA/TSRA DEVELOPMENT DURING THE AFTERNOON. APPEARS THE BEST CHANCES ARE ON TAP FOR SUN NIGHT INTO MON MORNING...THOUGH I CAN NOT SEE GOING HIGHER THAN 40 POPS GIVEN THAT THE AMS WILL ONLY HAS TIME TO DESTABILIZE TO MARGINAL LEVELS. A LOT OF QUESTION MARKS IN THE EXTENDED W/ REGARD TO RAFL CHANCES. PER AVN...COULD SEE A REPEAT OF SUN NIGHT/MON ON TUE NIGHT/WED. THE SEA BREEZE MAY BE ACTIVE IN BETWEEN AS WELL. WILL SEE HOW THE NEW MRF DEPICTS THINGS BEFORE I MAKE MY FINAL DECISIONS. CWF: WINDS ARE LIGHT AND SOMEWHAT VARIABLE ACROSS MOST OF MY WATERS...HOWEVER LOOKING UPSTREAM ACROSS MHX/S WATERS NE FLOW IS ON TAP. SO PLAN ON INITIALIZING W/ NE FLOW AROUND 15 KTS...THEN BECMG ELY 10 KT (E-SE SC WATERS). WEAK HIGH WILL MOVE OFF THE NC COAST TONIGHT...W/ LGT SELY FLOW EVENTUALLY VEERING AROUND TO THE S-SW LATE. 9S SE GROUND SWELL CONTINUES ACROSS THE WATERS. NOAA WAVEWATCH III HAS HAD A GOOD HANDLE ON THIS WAVE COMPONENT...WHICH LOOKS TO CONTINUE OVER THE NEXT COUPLE OF DAYS. NO FLAGS. FCSTID = 29 ILM 86 68 89 73 / 0 0 30 40 LBT 88 69 90 72 / 0 0 40 40 FLO 90 70 92 73 / 0 0 40 40 MYR 84 70 87 74 / 0 0 30 40 .ILM... NC...NONE. SC...NONE. PFAFF nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1130 AM EDT SAT JUL 7 2001 MAIN FORECAST CONCERNS ARE PCPN/TSRA IN SOUTHEAST FA TDA. HEMISPHERIC ANALYSIS SHOWING A BROAD RIDGE OVER SW CONUS AND A LONGWAVE TROF OVER THE GULF OF AK...STARTING TO MOVING INTO BC AND THE PAC NW. RUC/WV IMAGERY SHOWING A MCS ASSOC WITH A RATHER PRONOUNCED SHRTWV OVER SD THIS AM. THE FLOW AROUND THE BROAD ULVL RIDGE SHOULD PULL THIS TO THE S OF FA TDA. A WEAKER SHRTWV STRETCHED FROM NR KISN TO NR CWPL AT 13Z. A CDFNT EXTENDS FROM A LOW OVER EASTERN LAKE SUPERIOR THIS AM...TO A LOW NR KLSE...AND THRU THE CNTRL PLAINS. MESO-ETA AND AVN/RUC SEEM TO DISAGREE ON THE SPEED OF MOVEMENT OF THE CDFNT THUR FA TDA. RUC/AVN PULLS THE CDFNT INTO NRN LOWER BY 21Z...WHILE MESO-ETA HANGS THE FRONT BACK A LTL OVR CNTRL UP. HOWEVER...THE MDLS AGREE ON KEEPING THE SHRTWV ENERGY OVER WRN LAKE SUPERIOR BY 21Z. 310K ISENTROPIC ANLYS ON ALL MDLS FAVOR MODERATE ISENTROPIC LIFT OVER S CNTRL CWA. ULVL 90KT JET WILL SWING DOWN ACRS SRN PART OF CWA THIS AFTN. SFC DWPNTS REMAIN AROUND 60F THIS AM. LIMITING FACTOR SEEMS TO BE DRYNESS IN THE MLVL. WORKING THRU THE SEVERE WX CHECKLIST...THE BEST CHC OF TSRA WILL BE ARND KMNM BY LATE AFTN AS CAPE VALUES ARE XPCTD TO REACH 1.5KJ/KG. WILL KEEP CHC TSRA FOR THIS AFTN FOR SRN COUNTIES. SOME STRONG WNDS MAY ACCOMPANY THESE STORMS. XPCT SOME BLOWOFF FM THE STORMS TO THE W...SHOULD LIMIT HEATING AS WELL. WILL KEEP WITH MOS GUIDANCE. DRY AIR ADVECTING INTO FOR AREA OVRNGT. XPCT SKIES TO BCM CLR. WNDS WILL BE LGT WITH A APPROACH OF HI PRES RIDGE FOLLOWING THE FRONT. THIS SHOULD PERMIT SUBSTANTIAL RADIATIONAL COOLING. WILL POSSIBLY FALL BELOW GUIDANCE...AS MOS USUALLY DOES NOT HANDLE RADIATIONAL COOLING VERY WELL. COORDINATED WITH GRB AND APX. .MQT...NONE. DLG mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 1115 AM EDT SAT JUL 7 2001 MAIN QUESTION FOR THIS UPDATE IS THE CHANCE OF THUNDERSTORMS ACROSS UPSTATE SC/NE GA LATE THIS AFTERNOON...WITH MORE FACTORS SUGGESTING THAT DEEP MOIST CONVECTION WILL NOT HAPPEN. MORNING RAOBS SHOW PRONOUNCED NOSE OF MID LEVEL WARM AIR THAT SHOULD PROVE TO BE A FORMIDABLE CAP ON CONVECTION. THERE WOULD APPEAR TO BE VERY LITTLE CHANCE OF PRECIPITATION ACROSS THE NC PIEDMONT WHERE SURFACE DEWPOINTS SHOULD FALL OR REMAIN IN THE LOWER 60S. WEAK SHORT WAVE OVER EASTERN KY SHOULD DROP TO THE SE AND ACROSS THE FORECAST AREA DURING THE MIDDLE OF THE DAY. VISIBLE SATELLITE IMAGERY SHOWS HIGH AC ASSOCIATED WITH THIS WAVE SPREADING ACROSS THE FORECAST AREA AT 15Z. THIS CLOUDINESS WILL CUT DOWN ON HEATING AND INSTABILITY AND MAY FORCE ME TO CUT THE HIGH TEMP FORECAST DOWN A FEW DEGREES IN SOME ZONES. THE ETA AND RUC SHOW THE SHORT WAVE MOVING PAST THE FORECAST AREA BY MID AFTERNOON WITH DNVA ACROSS THE FORECAST AREA. IN SPITE OF ALL THIS NEGATIVE STUFF...THINK THAT THUNDERSTORMS ARE STILL A POSSIBILITY ACROSS THE WESTERN PART OF THE UPSTATE IN AN AREA OF LOW LEVEL FORCING ASSOCIATED WITH THE CONVERGENCE BETWEEN THE E TO SE LOW LEVEL FLOW AROUND THE BOTTOM OF THE SURFACE HIGH ALONG THE MID ATLANTIC COAST AND THE WEAK WESTERLY FLOW ACROSS TN/GA. THIS AREA ALSO STANDS THE BEST CHANCE OF DEVELOPING A FEW UPDRAFTS THAT COULD BREAK THE CAP LATE IN THE DAY GIVEN SLIGHTLY HIGHER SURFACE DEWPOINTS. .GSP... GA...NONE. NC...NONE. SC...NONE. MOORE sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 1005 AM EDT SAT JUL 7 2001 MSAS INDICATES OLD FRONTAL BOUNDARY BETWEEN BEAUFORT AND SAVANNAH. WITH ONSHORE FLOW TODAY...TEMPERATURES ALREADY A FEW DEGREES COOLER THAN YTD AT THE SAME TIME. RUC SHOWS S/WV MOVING ACROSS CWA LATE THIS AFTN/EARLY EVENING WITH SOME LOLVL MOISTURE AVAILABLE...SO THERE COULD STILL BE WIDELY SCATTERED/SCATTERED SHOWERS AND THUNDERSTORMS LATER THIS AFTERNOON IN THE EVENING HOURS. MINOR CHANGES TO THE WINDS ON UPDATE...OTHERWISE NO SIGNIFICANT CHANGES. CWF...CD FNT HAS PUSHED INTO SRN PTN OF THE SC WATERS THIS MORNING. BEHIND THE FRONT...PG A SOLID 15 KT OUT OF THE E-NE AS EVIDENCED BY OBS AT 41004 AND FBIS1. EVEN STRONGER UPSTREAM AT FPSN7. WILL INITIALIZE SC WATERS AT E 15 KT AND 3-4 FT. WILL INITIALIZE THE CHS HARBOR AT E 10-15 KT. WINDS WILL VEER TO SE BY LATE AFTN. OVER THE GA WATERS...SW WINDS WILL BECOME S THIS AFTN. NO CHGS PLANNED. FCSTID = 30 CHS 89 73 93 74 / 20 10 40 40 SAV 91 72 94 74 / 30 20 30 50 CHL 91 76 97 77 / 20 10 40 40 NBC 90 74 93 75 / 20 10 40 40 RBW 91 70 94 73 / 20 10 40 30 .CHS... GA...NONE. SC...NONE. TJR/JH sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 947 AM EDT SAT JUL 7 2001 SOME CHANGES IN STORE TO CURRENT FCST. ELY FLOW HAS SET UP OVER THE AREA WITH SOME MID AND HIGH LEVEL CLOUDS AROUND. ACARS SOUNDING THIS AM SHOWS H85 TEMP AROUND 17C. SFC TEMPS AROUND 4 DEG COOLER TDY THAN YDY SO I THINK TEMPS WONT GET AS HIGH AS YDY, WILL CUT BACK TEMPS AROUND ONE CAT. ALSO BUFKIT INDICATING BNDRY LYR WINDS AROUND 13KTS, SO WILL BUMP UP WINDS TO AROUND 15 MPH THIS AFTN. SYNOPTICALLY...HIGH PRESS OVR MID ATLC WILL SLIDE TO THE ESE. OLD FRONTAL BOUNDARY COULD CAUSE AN ISOL SHRA/TSRA THIS AFTN IN BURKE, BARNWELL, OR BAMBERG COUNTIES...POSSIBLY REACHING AS FAR N AS AGS. RUC AND AVN SHOW MOST OF THE CWA MUCH MORE STABLE THAN ETA, WHICH WAS VERY HIGH WITH LI'S YDY. FCSTID = 17 CAE 90 72 93 73 / 0 0 50 30 AGS 90 71 93 72 / 10 10 50 30 SSC 90 72 93 73 / 0 0 50 30 OGB 90 72 93 73 / 0 0 50 30 .CAE... GA...NONE. SC...NONE. JDB sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NASHVILLE TN 956 AM CDT SAT JUL 7 2001 13Z SURFACE ANALYSIS SHOWED A WARM FRONT EXTENDING FROM WI S ACROSS IL AND W TN...THEN BECOMING STATIONARY FROM NE MS THROUGH SE GA. SURFACE HIGH PRESSURE WAS SPREAD ACROSS THE SOUTH AND INTO MID ATLANTIC REGION. BOTH 12Z 850/700 MB ANALYSES SHOWED STRONG WARM ADVECTION TO OUR NW AND N...WITH STRONGEST PUSH ACROSS IL...IN AND OH WHERE STRONGER WIND FIELDS WERE LOCATED. SOMETIME AROUND 07Z A MESOSCALE CONVECTIVE COMPLEX (MCS) BEGAN TO DEVELOP ALONG THE WI/IL BORDER IN AREA OF STRONG LOW LEVEL WARM ADVECTION NEAR NOSE OF LOW LEVEL JET. THE DEVELOPMENT ALSO FIT THE APPROXIMATE LOCATION WHERE ONE MIGHT EXPECT USING SATURATION THICKNESS VALUES. THE MCS HAS NOW TAKEN A MORE SE COURSE AND CURRENTLY IS OVER N CENTRAL IN INTO W CENTRAL OH. THE BEST CHANCES OF ANY PRECIP TODAY WILL BE N OF US...WITH THE LEAST CHANCES TO OUR W...WHERE QUITE WARM TEMPS ALOFT MAY ACT TO INHIBIT DEVELOPMENT THIS AFTERNOON. LATEST RUC MODEL FORECASTS RISING 1000/500 MB THICKNESS VALUES THIS AFTERNOON...WITH SLIGHT WARMING AT 500 MB LEVEL AS WELL. AXIS OF HIGHEST THETA-E VALUES AT SURFACE FORECAST TO BE TO OUR W AND N. IT IS POSSIBLE THAT LATE THIS AFTERNOON SOME CONVECTION MAY DEVELOP IN KY AND DEVELOP AS FAR S AS N MIDDLE TN...BUT RIGHT NOW IT LOOKS RATHER DOUBTFUL. CURRENT SLIGHT CHANCE IN FORECAST FOR THAT AREA LOOKS OK AT THIS TIME. HIGH TEMP FORECAST FOR THIS AFTERNOON LOOKS OK FOR THE MOST PART. WILL ISSUE UPDATE TO CHANGE FORECAST WORDING SLIGHTLY. .BNA...NONE. STEIGERWALDT tn SOUTH CENTRAL AND SOUTHEAST COLORADO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO COLORADO 141 PM MDT SAT JUL 7 2001 CURRENTLY: LATEST WATER VAPOR IMAGERY/RUC 400MB MODEL DATA ANALYSES AND 12Z/07 UPPER AIR ANALYSES SHOWED ANTICYCLONE HAS SHIFTED EWD INTO THE CNTRL PLAINS. HIGH CENTROID AROUND S CNTRL KS. 500-250MB WINDS PRETTY MUCH S-SELY PER LAPS SOUNDINGS AND UPPER AIR ANALYSES. NOTICED FAIRLY STEEP 500MB TEMP/DEW POINT DEPRESSIONS...20-30C... ACROSS NM...CNTRL AND SRN PLAINS. UPPER LEVEL "DRY" SLOT OVER ERN CO PER WATER VAPOR IMAGERY...AND HAS EVEN "BACKDOORED" INTO SAN JUAN MTNS LIMITING TSTM DEVELOPMENT THERE. NO LIGHTNING STRIKES IN CWFA...YET. MDL'S 0-3HR PROB OF LIGHTNING SUGGEST ONLY A SMALL POTENTIAL IN THE UPPER AR RIVER VALLEY AND PIKES PEAK BETWEEN 19Z- 22Z. WEAK OLD OUTFLOW BOUNDARY MOVED THROUGH SERN CO BETWEEN 15Z-18Z PER SFC OBS/RADAR. THERMAL LOW..."LA JUNTA LOW"...ALREADY FORMING. A FEW LOW LEVEL CONVG SPOKES IN SERN CO. TSTM INITIATION IN SERN CO SHOULD BE TOUGH WITH RELATIVELY DEEP "DRY" AIR MASS...20MB MOISTURE LAYER AROUND 600MB...AND CAPPING INVERSION. OLD QUASI-STATIONARY FRONT FROM KFNL-KAKO-KITR-KGLD-KMCK PER 16Z/07 SFC ANALYSIS. 18Z/07 SFC ANALYSIS HAD FULL FRONTAL RECOVERY IN NE...BUT SFC WINDS STILL OUT OF THE NE IN NERN CO. KLIC NELY WIND MAY BE MORE INFLUENCED BY "LA JUNTA LOW" THAN FRONTAL BOUNDARY. TEMPS APPROACHING 100F AGAIN IN LOWER AR RVR VALLEY. DESERT SW/GREAT BASIN "MONSOON" IS UNDERWAY PER SFC/UPPER AIR ANALYSES AND SATELLITE IMAGERY. RGNL RADARS NOT SHOWING MUCH SHRA/TSTM FORMING...AT THE MOMENT. CU/ TCU OUT THE WINDOW NOT ALL THAT IMPRESSIVE...EITHER. TNGT: POTENTIAL FOR ANOTHER NOCTURNAL MCS TO FORM NEAR THE RGN. BEST THREAT AREA WOULD BE ERN WY/NERN CO/SD/NE AROUND THE EDGE OF THE MID LEVEL THERMAL "CAP." ALL THE BEST THERMAL/MOISTURE ADVECTION PARAMETERS ARE POINTING MCS DEVELOPMENT N OF CO...BUT ALL DEPENDS IF QUASI-STATIONARY BOUNDARY OVER NERN CO CAN MIX OUT...OR LIFT NWD THIS AFTN. SHALLOW OROGRAPHIC LIFT WILL HELP WITH TSTM INITIATION IN N CNTRL/NERN CO. IF NOCTURNAL MCS DOES FORM TNGT...IT SHOULD MIGRATE EWD THROUGH THE NRN/CNTRL PLAINS. THIS IS IMPORTANT AS ANY TSTM OUTFLOW BOUNDARIES COULD MOVE INTO SERN CO LATER TNGT AND KEEP THE POTENTIAL FOR TSTM DEVELOPMENT. MODELS HAVE BEEN CONSISTENT WITH 850- 700MB 5-15KT NLY FLOW ACROSS SERN CO TNGT. THE BIGGEST...AND MOST CRITICAL...ELEMENT MISSING IS VERTICAL MOISTURE TO WORK WITH FOR TSTM DEVELOPMENT ACROSS MUCH OF CWFA...EXCEPT SAN JUAN MTNS/COLLEGIATE PEAKS. AIR MASS BECOMES MORE STABLE WITH TIME TNGT. ETA/MESO-ETA ARE PRINTING OUT NO QPF ACROSS A GOOD PORTION OF CWFA TNGT...EXCEPT THE SWRN/CNTRL CO MTNS THIS EVE. PLAN TO GO WITH DIURNAL ISOLD-SCT COVERAGE SERN MTNS AND WWD TNGT. ALONG I-25 CORRIDOR WILL HOLD ONTO SMALL CONDITIONAL POP DUE TO UNCERTAINTY. DURING THE PAST FEW NGTS... WE HAD LATE NGT SURGES AND OUTFLOW BOUNDARIES THAT DIDN'T PRODUCE ANYTHING...NOT EVEN CLOUDS. SUN-SUN NGT: UPPER LEVEL PATTERN DOESN'T CHANGE MUCH ON SUN. HARD TO FIND A SYNOPTIC SCALE TRIGGER. WEAK ELY WAVES MOVE ACROSS SRN PLAINS TOWARDS SERN CO...BUT ARE WEAK AND HARD TO TRACK. WEAK E-NELY LOW LEVEL FLOW TO DEVELOP ACROSS SERN CO...ESPECIALLY SUN AFTN...WILL BE THE ONLY HOPE FOR TSTM INITIATION. SFC BASED LIS PROGGED TO BE -2 TO -6C ACROSS SERN CO MTNS/PLAINS WITH SOME CAPE TO WORK WITH...600-2000 J/KG. MESO-ETA HINTS AT TSTM DEVELOPING IN SERN CO MTNS AROUND 21Z THEN SPREADING INTO ADJACENT PLAINS. LOW LEVEL CONVG ZONE SETS UP ACROSS SERN CO SUN EVE WHICH SHOULD ACT AS A TSTM INITIATION FOCAL POINT...ALONG WITH ANY TSTM OUTFLOW BOUNDARIES. INITIALLY...MUCH OF THE AVAILABLE MOISTURE TO WORK WITH IS AOA 500MB...AND IS A LITTLE DEEPER ALONG THE CONTDVD. PLAN TO BOOST SERN CO MTNS/PLAINS POPS TO 40% SUN NGT. ALSO WILL NOT GO WITH ANY "TIMERS" SUN NGT AS MODELS HINTING AT THE POTENTIAL FOR A NOCTURNAL MCS ACROSS ERN CO/WRN NE. TEMPS AOA JUL AVES. MOS GUIDANCE TEMPS TYPICAL...WARMER FWC AND COOLER MAV. WILL STICK CLOSE TO PERSISTENCE. MON-MON NGT: IF SUN NGT TSTMS DO DEVELOP...THIS SHOULD HELP MOISTEN LOW LEVELS IN SERN CO. ETA/MESO-ETA SUGGESTING SLIGHTLY HIGHER SFC DEW POINTS...55-60F...ACROSS SERN CO MON-MON NGT. SYNOPTIC SCALE PATTERN AND KINEMATICS ARE FAIRLY PERSISTENT...SO MORE OF THE SAME PRECIPITATIONWISE. MAX TEMPS ACROSS SERN CO MTNS/PLAINS MAY BE A FEW DEGS COOLER GIVEN A SLIGHTLY COOLER MID LEVEL...EARLIER AND GREATER CLOUD COVER...AND POTENTIAL TSTMS. AGAIN...MOS GUIDANCE NIGHT AND DAY...FWC WARMER AND MAV WAAAAY COOL(ONLY 75F AT KCOS MON). PLAN TO COOL TEMPS SLIGHTLY FROM CURRENT ZFP NUMBERS...BUT NOT AS MUCH AS MAV GUIDANCE. EXTENDED(TUE-SAT): DAY 3-7 MODELS SUGGEST HIGH OVER CNTRL PLAINS WILL RETROGRADE TO NEAR SERN CO BY DAYS 6-7. ECMWF HAS HIGH DIRECTLY OVER SERN CO BY DAY 7...WHILE MRF HAS IT OVER NM. THIS MEANS CWFA WILL BE FLIRTING WITH ERN FRINGE OF DESERT SW/GREAT BASIN "MONSOON." JUST WISH MY YARD WILL GET ALL THAT MRF QPF DURING TUE-SAT! TEMPS WILL LIKELY BE AOA JUL CLIMO WITH TYPICAL DIURNAL SLGT CHC-CHC TSTM. PUB...NONE. METZE co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE/WASHINGTON 235 PM EDT SAT JUL 7 2001 MOSTLY SUNNY SKIES ACROSS THE AREA AT TIME WITH HIGH PRESSURE MOVING OFF THE ATLANTIC COAST. MCS OVER OHIO AND KENTUCKY MOVING SOUTHWARD ALONG MID LEVEL THICKNESS CONTOURS. PRECIP FROM THIS SYSTEM WILL STAY WELL TO THE WEST.. BUT SOME OF THE CIRRUS SHIELD SHOULD WORK INTO THE WESTERN SECTIONS OF THE FA THIS EVENING. MID LEVEL WARM FRONT MOVING OVER THE AREA LATE TONIGHT. WARM ADVECTION SETTING UP AT 850 AND 700 MB. 12Z IAD SOUNDING AND EARLY EVENING MODEL SOUNDINGS FROM THE 12Z ETA AND RUC SHOW VERY DRY AMS AT THE LOW LEVELS... BUT ETA/AVN IN AGREEMENT THAT ENOUGH SATURATION WILL OCCUR WITH ISENTROPIC LIFT LATER TONIGHT TO WARRANT AT LEAST A CHANCE OF PRECIP FOR THE NORTHERN HALF OF THE AREA. COLD FRONT MOVING THROUGH THE AREA TOMORROW AFTERNOON AND EVENING... WITH SOME TIMING DIFFERENCES STILL SHOWING UP BETWEEN MODELS. ETA HOLDING FRONT UP UNTIL SUNDAY EVENING WHILE AVN ABOUT 6 HOURS FASTER. EITHER WAY... MODEL SOUNDINGS FOR SUNDAY AFTERNOON SHOWING LI VALUES AROUND -5 AND CAPES OVER 2000 SO ENOUGH INSTABILITY PRESENT FOR SCATTERED SHOWERS AND THUNDERSTORMS. ONLY QUESTION IS HOW LONG TO KEEP PRECIP IN THE FORECAST... AND PLANNING AT TIME TO END PRECIP WEST OF THE BLUE RIDGE BY 00Z MONDAY. AVN/MRF... ECMWF AND CANADIAN ALL SPEED UP WAEK COLD FRONT THROUGH THE AREA THROUGH MID WEEK. WILL BUMP PRECIP UP IN THE EXTENDED TO TUESDAY AND TUESDAY NIGHT. END OF NEXT WEEK HAS UPPER LEVEL TROUGH DIGGING DOWN ACROSS NEW ENGLAND. SHOULD BE A DRY PATTERN WITH SURFACE HIGH IN PLACE... BUT TEMPERATURES WILL PROBABLY END UP 3-5 DEGREES BELOW NORMAL. DCA 69 87 71 89 / 20 30 30 0 BWI 66 88 69 88 / 30 30 30 0 MRB 67 87 66 89 / 30 30 10 0 IAD 66 88 66 90 / 30 30 30 0 CHO 67 89 69 90 / 10 30 30 0 HGR 66 86 66 87 / 30 30 10 0 NHK 70 88 71 89 / 10 30 30 0 W99 67 89 68 90 / 30 30 10 0 .LWX... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARGRAF! md AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 415 PM EDT SAT JUL 7 2001 MAIN FORECAST CONCERNS ARE SHRA/TSRA CHANCES SUN AFTERNOON AND MONDAY. WV IMAGERY AND RUC ANALYSIS INDICATED SEVERAL WEAK SHRTWVS EMBEDDED IN FAST WNW FLOW FROM SRN CANADA TO THE GRT LAKES BTWN SRN CONUS RDG AND HUDSON BAY TROF. ONE WEAK 700-500 MB SHRTWV OVER NRN WI AND ASSOCIATED WEAK 315K ISENTROPIC LIFT HAD BROUGHT SOME -SHRA OR SPRINKLES FROM NE WI INTO MNM COUNTY...PER KMQT/KGRB 88DS. SUBSTANTIAL DRYING NOTED AS UPR LVL 110KT JET MOVES INTO LK SUPERIOR. AT THE SFC...DECAYING FRNTL BNDRY HAD MOVED TO POSITION FROM FAR ERN UPR MI INTO CNTRL WI. SYNOPTIC FRNT POSITION OBSCURED A BIT BY WEAK WIND FIELD WHICH HAS ALLOWED LK BREEZE DEVELOPMENT OFF OF LK SUPERIOR AND LK MI WITH LCL CONVERGENCE AREA NRTH OF THE FRNT. DEEPER CONVECTION HAD INITIATED CLOSER TO THE FRNT NEAR GRB WHERE T/TD NEAR 85/72 RAISED CAPES TO AROUND 2.0K J/KG. CLOUD COVER OVER UPR MI HAS LIMITED INSOLATION/INSTABILITY DESPITE TD STILL IN THE MID 60S F. MDLS WERE IN REASONABLE AGREEMENT WITH RESPECT TO FEATURES AFFECTING UPR MI. ETA GENERALLY FOLLOWED FOR LLVL DETAILS. TONIGHT...ENHANCED LK BREEZE CONVERGENCE HAS NOT BEEN ENOUGH TO OVERCOME LIMITED HEATING FROM THICKER CLOUD COVER AND WARM 750-650 LYR PER 12Z KAPX/KGRB AND RUC/ETA FCST SNDGS. SO...TSRA CHANCES HAVE DWINDLED WITH BEST POTENTIAL SOUTH AND EAST OF UPR MI. VIS LOOP TRENDS SUGGEST CLEARING OVER WRN 1/3 WILL PROGRESS ACRS REST OF THE CWA THIS EVENING LEAVING MOSTLY CLEAR SKIES. WEAK DRY ADVECTION (LOW TO MID 50S TD UPSTREAM OVER NE MN AND ONTARIO) WITH DIMINISHING NW FLOW SHOULD ALLOW TEMPS TO DROP INTO THE MID 50S OVERNIGHT WITH GOOD RADIATIONAL COOLING LATE. GRADIENT SHOULD ALSO BE WEAK ENOUGH 950 TO WINDS OF 10 TO 15 KTS) ALLOW WINDS TO MOSTLY DECOUPLE. SUNDAY...WNW LLVL FLOW CONTINUE ACRS UPR MI WITH POTENTIAL AGAIN FOR MID PENINSULA LK BREEZE CONVERGENCE OVER THE ERN CWA. WITH DRIER AIR FCST (TD IN THE MID AND UPPER 50S F) CAPE VALUES SHOULD BE MINIMAL (BLO 400 J/KG). UPR LVL SUPPORT ALSO LACKING WITH RRQ DIV FROM JET LAGGING TO THE WEST FROM THE NRN PLAINS TO UPR MS VALLEY. WHILE IT MAY NOT BE IMPOSSIBLE FOR ISOLD SHRA/TSRA TO DEVELOP...WITH ONLY LO CHANCE AND MINIMAL COVERAGE AT BEST...IT DOES NOT WARRANT MENTION ATTM. FCST NW 950 WINDS OF 10-15 KTS SHOULD BE WEAK ENOUGH TO ALLOW LK BREEZE INTO SHORELINE VCNTY NEAR MARQUETTE DURING THE AFTERNOON AFTER EARLIER HIGH NEAR PREVIOUS FCST VALUES. AVN/ETA SUGGEST THAT SHRTWV MAY BRUSH AREA SUNDAY NIGHT BUT THAT BEST QG FORCING REMAINS TO THE NORTH AND EAST WHERE ONLY QPF IS DEPICTED. ETA/AVN/UKMET ANOTHER WEAK SHRTWV ACCOMPANIED BY A MORE PRONOUNCED SFC TROF/FRNT WILL MOVE THROUGH ON MONDAY WITH TROF JUST SOUTH OF UPR MI BY 00Z/TUE. WITH LITTLE IF ANY ADDITIONAL MOISTURE INFLOW EXPECTED ONLY LOW CHANCE POPS MENTIONED. EXTENDED...MRF/UKMET/ECMWF IN REASONABLE AGREEMENT FOR THE REMAINDER OF THE WEEK WITH ECMWF DISPLAYING BEST CONTINUITY WITH PROGRESSION OF TROF FROM HUDSON BAY INTO ERN CANADA. ACCORDINGLY...ECMWF PREFERRED WITH SLIGHTLY LESS AMPLIFIED FLOW INTO THE WRN LAKES AND TEMPS NOT QUITE AS COLD (AVERAGING 4C WARMER AT H8 THAN MRF). HOWEVER...SFC RDG INTO THE WRN LAKES WITH NRLY FLOW SHOULD BRING TEMPS A BIT BLO CLIMATOLOGY...ESPECIALLY FOR LK SUPERIOR SHORELINE LOCATIONS. WHILE WEAK SHRTWVS MAY DESCEND INTO THE AREA FROM THE NW...LOCATION OF MAIN SFC BNDRY WITH BEST MOISTURE FAR TO THE SW...SUGGESTS UPR MI WILL REMAIN DRY. CONFIDENCE FOR COMPLETELY DRY FCST DIMINISHES BY SATURDAY...HOWEVER...AS FLOW DEAMPLIFIES WITH BETTER POSSIBILITY OF SIGNIFICANT SHRTWV AFFECTING THE AREA WITH SOME MOISTURE RETURN. .MQT...NONE. JLB mi SOUTHEAST MICHIGAN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 315 PM EDT SAT JUL 7 2001 RECENT GOES-E VISIBLE IMAGERY AND REGIONAL 88DS SHOWING AN AREA OF SHOWERS AND THUNDERSTORMS ACROSS SOUTHERN WISCONSIN/NORTHERN ILLINOIS/SOUTHERN LAKE MICHIGAN. ADDITIONAL SHOWER/STORM ACTIVITY WAS OBSERVED ACROSS THE UPPER PENINSULA/NORTHERN WISCONSIN ALONG A SURFACE BOUNDARY DRAPED FROM THE NEAR THE STRAITS TO CENTRAL IOWA AND NEBRASKA. COVERAGE OF SHOWERS NEAR THE BOUNDARY HAS BEEN GENERALLY DECREASING IN FAVOR OF DEVELOPMENT FARTHER SOUTH NEAR THE SURFACE/850MB WARM FRONT AND THE EDGE OF THE 700MB THERMAL CAP. WEAK CONVECTION NEAR CHICAGO- ALONG THE SURFACE WARM FRONT- HAS TAKEN ON A LINEAR STRUCTURE OVER THE PAST HOUR, LIKELY IN RESPONSE TO STRONG MID LEVEL FLOW (700-500MB) OF 40-50KTS. EXPECT THAT THIS ACTIVITY WILL BEGIN TO VEER TOWARD THE SOUTHEAST, AS SUGGESTED BY THE 15Z RUC-40 850-300MB MEAN WIND AND THERMAL WIND. THE LACK OF INSTABILITY OVER THE FORECAST AREA (DUE TO PROLONGED CLOUDCOVER) AND THE INTERCEPTION OF ELEVATED POTENTIAL BY THE AFOREMENTIONED ACTIVITY ALONG THE WARM FRONT SHOULD PRECLUDE WIDESPREAD CONVECTIVE DEVELOPMENT IN ADVANCE OF THE UPSTREAM FEATURES. THE AXIS OF STRONGEST 850-500MB WINDS REMAINS SOUTH OF THE FORECAST AREA, PINNING THE GREATEST THREAT FOR SEVERE WINDS ACROSS FAR SOUTHWEST LOWER/NORTHERN INDIANA AND OHIO, WHERE THE HODOGRAPHS REMAIN LONG AND LOW-LEVEL SHEAR STRONG ENOUGH FOR LINEAR ORGANIZATION. NEVERTHELESS STILL ANTICIPATE SCATTERED SHOWER COVERAGE WITH A CHANCE OF THUNDER ACROSS THE NORTHERN SECTIONS WITH THE BOUNDARY PINCHING IN AND DEWPOINT POOLING (LOWER 70S IN NORTHERN WISCONSIN)- ALONG WITH WEAK 850MB WARM ADVECTION, WITH BETTER SHOWER AND THUNDER COVERAGE ACROSS THE SOUTHERN SECTIONS CLOSER TO THE INSTABILITY AXIS. HIGH PRECIPITABLE WATER VALUES (>1.8IN) ACROSS THE FAR SOUTH AND THE POSSIBILITY OF REGENERATIVE CONVECTION ALONG THE INSTABILITY GRADIENT CONTINUE TO POSE THE THREAT FOR HEAVY RAINFALL TONIGHT. NCEP/DTX SUITES CONTINUE TO STRUGGLE WITH CONVECTIVE FEATURES DURING THE FIRST PERIOD. THE ETA-XX HAS BEEN THE BEST PERFORMER, ESPECIALLY WITH MCS DEVELOPMENT, BUT HAS STILL LACKED SKILL WITH PINPOINTING LESS PROMINENT FEATURES. CONVECTION POSSIBILITIES WILL EXIST UNTIL THE SURFACE BOUNDARY- ESSENTIALLY A DRYLINE- CLEARS THE AREA. THE WESTERN REACHES OF THE BOUNDARY- ACROSS IOWA- WILL REMAIN QUASI-STATIONARY, AS THE SURFACE HIGH SKIRTS THE UPPER RIDGE, DEFORMING THE BOUNDARY SOUTHWARD ACROSS THE LAKES REGION (ALMOST IN BACKDOOR FASHION). PASSAGE TIMING CONTINUES TO BE INCONSISTENT IN THE NEAR-TERM PROGS (INTERCOMPARISON AND RUN-TO-RUN). THE NCEP ETA-22 IS THE SLOWEST, LAGGING ACROSS EXTREME SOUTHERN LOWER POST-12Z SUNDAY. IT APPEARS THIS CHANGE IN THE ETA TIMING FROM IT/S PREVIOUS RUNS IS RELATED TO THE DEVELOPMENT OF CONVECTION ON THE MOIST SIDE ACROSS NORTHERN ILLINOIS AND INDIANA TONIGHT, RETARDING THE SOUTHWARD MOVEMENT. HOWEVER, GIVEN THAT THE EVEN THE ETA MEAN CLOUD LAYER (850-300MB) FLOW WILL BE TOWARD THE E-SE AND CORFIDI VECTORS TOWARD THE SOUTH (SUGGESTING NEW CELL DEVELOPMENT ON THE OPPOSITE SIDE OF THE CONVECTIVE STRUCTURES FROM THE BOUNDARY), THE FASTER TIMING OFFERED BY ALL THE OTHER SOLUTIONS APPEARS MORE VIABLE. THE WEAK SURFACE RIDGING ON SUNDAY WILL BE ACCOMPANIED BY A DEEP LAYER OF DRY AIR, EVIDENCED ACROSS NORTHERN MINNESOTA INTO LAKE SUPERIOR ON GOES-E VAPOR IMAGERY. ABUNDANT INSOLATION, LACK OF MOISTURE THROUGHOUT THE COLUMN, AND THE ABSENCE OF COLD ADVECTION WILL ALLOW TEMPERATURES TO EASILY RISE ABOVE TODAY/S LEVELS. A FEW SHALLOW PANCAKE CUMULUS MAY DEVELOP, ESPECIALLY IN AREAS THAT RECEIVE MORE RAINFALL TONIGHT, BUT NOT ENOUGH TO PREVENT MOSTLY SUNNY WORDING. FWCS CONTINUE TO BE TOO HIGH (92 AT DTW), WILL FAVOR COOLER MAV/ETA 2M TEMPS (MID-UPPER 80S), BASED ON TRAJECTORY ANALYSES AND CURRENT UPSTREAM READINGS. LAKE BREEZES SHOULD SETUP NEAR LAKE HURON WHERE LAKE SURFACE TEMPS ARE IN THE LOW 60S AND LOW-LEVEL RIDGING WILL KEEP THE GRADIENT FLOW WEAK. SIMILAR CONDITIONS WILL PREVAIL MONDAY, WITH SURFACE TEMPS A COUPLE DEGREES HIGHER AS THE 850-700MB COLUMN WARMS IN RESPONSE TO WARM ADVECTION FROM THE WEST OFF THE HEAT DOME OVER THE PLAINS STATES. THE SURFACE BOUNDARY ALSO ATTEMPTS TO MAKE A MOVE NORTH INTO SOUTHERN LOWER MICHIGAN MONDAY. THE AVN PRODUCES AN MCS IN THE VICINITY OF THE BOUNDARY TO OUR WEST AND SOUTH ON MONDAY, WITH SOME RESIDUAL QPF OVER THE FORECAST AREA MONDAY EVENING NEAR THE AXIS OF WEAK SURFACE CONVERGENCE. THE 12Z ETA-XX IS SIMILAR TO THE AVN, WITH LESS COVERAGE OVER THE SOUTHERN LAKES REGION. WITH PRECIPITABLE WATER VALUES INCREASING TO NEAR 1.5IN AND THE PRESENCE OF A SURFACE BOUNDARY AND WEAK SHORTWAVE INFLUENCES, THE CHANCE OF PRECIP MONDAY NIGHT ARE NOT NILL, BUT WILL HOLD OFF THE MENTION FOR NOW. LONGWAVE REGIME WILL PERSIST THROUGH MUCH OF THE UPCOMING WEEK. LITTLE CHANGE TO THE KEY COMPONENTS- EASTERN HUDSON BAY LOW AND INTERMOUNTAIN WEST RIDGE AXIS. TREND ANALYSIS (MRF/GLOBAL/ETA-XX) DEPICTS GREATER AMPLIFICATION TO THE REGIME (ESPECIALLY THE EASTERN NORTH AMERICAN TROUGH), RESULTING IN LOWER HEIGHTS ACROSS THE REGION DURING MID-WEEK, WITH SOME RECOVERY BY WEEK/S END. LITTLE DISAGREEMENT AMONG THE EXTENDED PROGS REGARDING THE LONGWAVE PATTERN EVOLUTION. HOWEVER, THE SOME DISCREPANCIES REGARDING SHORTWAVE FEATURES PROPAGATING OVER THE RIDGE AXIS INTO THE NORTHWEST FLOW OVER THE LAKES REGION. THE MRF LACKS CLEAR DEFINITION, WHILE THE CMC GLOBAL PRODUCES A SIGNIFICANT, CONCENTRATED SHORTWAVE TROUGH OVER THE NORTHERN PLAINS BY 144H. THE ETA-XX RESIDES BETWEEN WITH A SERIES OF WEAK IMPULSES TO AFFECT THE REGION FRIDAY AND SATURDAY. BASED ON THE TREND TOWARD LONGWAVE RE-AMPLIFICATION, THE GLOBAL DEPICTION OF A SHORTWAVE TROUGH FLATTENING THE RIDGE OUT WEST APPEAR OVERDONE, WHILE THE LACK OF ANY FEATURES IN THE MRF APPEARS JUST AS UNREASONABLE. THEREFORE, EXPECT THAT A SOLUTION MORE SIMILAR TO THE ETA-XX. AS IS TYPICAL WITH NORTHWEST FLOW DURING THE SUMMER SEASON, THESE WAVES SHOULD BE THE IMPETUS FOR THUNDERSTORM DEVELOPMENT UPSTREAM, WHICH WILL EVENTUALLY MOVE INTO THE LAKES REGION. MAXES SHOULD REBOUND BACK TO SEASONABLE LEVELS FRIDAY AND SATURDAY AS HEIGHTS AND THICKNESSES INCREASE. .DTX...NONE. MANN mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 233 PM CDT SAT JUL 7 2001 ...LATE NIGHT CONVECTION AND HEAT INDICES REMAIN THE CHALLENGES... BEGINNING WITH THE THREAT FOR CONVECTION...PATTERN REMAINS VERY SIMILAR TO LAST 24 HOURS...WITH SYNOPTIC REGIME IN PLACE FOR ANOTHER MCS ORIGINATING IN HIGH PLAINS AND MOVING EAST OVERNIGHT...AND THEN POSSIBLY AGAIN SUNDAY NIGHT. THE MODELS ARE IN POOR AGREEMENT WITH THEIR QPF IN THIS PATTERN...WHICH IS TYPICAL OF SUMMER NOCTURNAL CONVECTION. RUC40 WAS BY FAR THE BEST AT REPRESENTING THE OUTFLOW AND FRONTAL BOUNDARY THIS MORNING...AND HAVE LEANED TOWARDS ITS SOLUTION INTO THIS EVENING. 19Z SURFACE ANALYSIS HAS DIFFUSE SYNOPTIC SCALE BOUNDARY EXTENDING FROM NEAR SIOUX CITY TO ERN COLORADO...WITH CHADRON SURFACE DEWPOINT 67. PER SWODY1 AND RUC40...AREA MOST LIKELY TO SEE CONVECTIVE INITIATION WOULD BE HIGH PLAINS THIS AFTERNOON AND EVENING...FROM NEBRASKA PANHANDLE WEST. WATERVAPOR IMAGERY SHOWS HINTS OF A SHORTWAVE MOVING INTO SRN WYOMING...WITH MORE SUBTROPICAL MOISTURE ROTATING AROUND THE UPPER RIDGE STILL CENTERED IN SOUTHWEST KANSAS. CONVECTION ALREADY DEVELOPING IN SNOWY RANGE OF SOUTHEAST WYOMING AND NORTH CENTRAL COLORADO AT 19Z. SYNOPTIC BOUNDARY SHOULD BE MORE QUASI-STATIONARY BY THIS EVENING...AND HIGH CAPE VALUES WILL RESIDE FARTHER EAST ALONG THE BOUNDARY. 850 BOUNDARY IS PROGGED SLIGHTLY FARTHER NORTH ACROSS NORTHERN NEBRASKA...AND BY 03Z 850 THETA-E ADVECTION MAX IS NEAR OFK. CORFIDI VECTORS SUGGEST A SLIGHT TURN TO THE RIGHT...OR SOUTHEAST...IF ORGANIZED CONVECTION DOES REACH NORTHEAST NEBRASKA. MISSING INGREDIENT MAY BE LOW LEVEL JET...BUT FRONTAL FORCING AND AMBIENT MOISTURE MAY BE SUFFICIENT WITHOUT A DECENT LOW LEVEL JET. THUS WILL CONTINUE 20-30 POPS IN NORTHEAST COUNTIES TONIGHT...AND AGAIN SUNDAY NIGHT. MODELS ADVERTISE MORE FORCING SUNDAY NIGHT AND MAY INCREASE POPS SUNDAY NIGHT...AND TREND FARTHER SOUTH... AND KEEP A MENTION ON MONDAY. BELIEVE THE AVN IS OVERDONE WITH PUSHING FRONT INTO SRN PLAINS MONDAY...WITH KANSAS MORE LIKELY FRONTAL POSITION. SOME ISENTROPIC FORCING OVER THE BOUNDARY WILL BE POSSIBLE ON MONDAY. AVN SHOWS UPPER RIDGE DROPPING A BIT SOUTHWEST BY MONDAY NIGHT...THUS PULLING STRONGER CAP EDGE FARTHER SOUTHWEST. TEMPERATURE AND WIND FORECASTS ARE HIGHLY DEPENDENT ON ANY CONVECTIVE OUTFLOW FROM ABOVE MENTIONED POSSIBLE MCS ACTIVITY...WITH HIGHER CONFIDENCE IN SOUTHERN ZONES FARTHER AWAY FROM MCS THREAT. MESOETA SURFACE TEMPERATURE PROGS HAVE BEEN SUPERIOR TO OTHER GUIDANCE NUMBERS WITH 100+ READINGS IN SOUTHERN ZONES. AT LEAST FOR SUNDAY WILL CONTINUE WITH THE WARM MESOETA TEMPERATURES...BUT BY MONDAY WILL TREND MORE TOWARDS MOS VALUES WITH HIGHER THREAT OF CONVECTIVE ACTIVITY. LOWS THIS MORNING WERE IN THE LOWER 80S FROM FALLS CITY INTO IOWA COUNTIES...WITH DEWPOINTS REMAINING IN LOWER 70S. SIMILAR LOWS EXPECTED TONIGHT...THUS NIGHT TIME HEAT ADVISORY CRITERIA BEING MET. BASED ON COORDINATION WITH GID/DSM/TOP/EAX...WILL CONTINUE THE HEAT ADVISORY TONIGHT INTO SUNDAY BUT TRIM SOME OF THE COUNTIES ON THE NORTHWEST FRINGE. .OMA...HEAT ADVISORY THROUGH SUNDAY NEZ052-053-066>068-078- 088>093 AND IAZ069-079-080-090-091 NIETFELD ne