Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/06/12
AREA FORECAST DISCUSSION
NWS TUCSON AZ
920 PM MST TUE JUL 3 2012
.SYNOPSIS...MUCH DEEPER MOISTURE WILL BRING WIDESPREAD SHOWERS AND
THUNDERSTORMS TONIGHT INTO WEDNESDAY. SOME STORMS WILL GENERATE VERY
HEAVY RAINFALL AND STRONG WINDS. LESS ACTIVITY THURSDAY AS THE
ATMOSPHERE RECOVERS...THEN A CHANCE OF MAINLY AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS INTO THE WEEKEND AND EARLY NEXT WEEK.
&&
.DISCUSSION...KEMX WSR-88D DETECTED NUMEROUS SHOWERS AND ISOLATED
THUNDERSTORMS ACROSS SE AZ AT 0415Z. FAR WRN PIMA COUNTY WAS VOID OF
PRECIP ECHOES AT THIS TIME. ISOLATED THUNDERSTORMS WERE ACROSS SWRN
COCHISE COUNTY...AND AN URBAN AND SMALL STREAM FLOOD ADVISORY IS IN
EFFECT UNTIL 1115 PM MST. ALSO...A FLASH FLOOD WARNING IS IN EFFECT
FOR SWRN COCHISE COUNTY...PARTICULARLY IN THE AREA NEAR AND JUST EAST
OF TOMBSTONE...UNTIL 1115 PM MST.
04/02Z RUC13 AND 04/00Z RUC HRRR AGREE THAT THE FAVORED AREA FOR
PRECIP THRU MIDNIGHT WILL BE SOUTH OF THE TUCSON METRO AREA...OR FAR
SE PIMA/SANTA CRUZ/SWRN COCHISE COUNTIES. THEREAFTER...CONVECTIVE
ACTIVITY MAY DECREASE FOR A FEW HOURS...THEN PRECIP IS PROGGED VIA
THE 04/00Z NAM TO REGENERATE ACROSS MUCH OF THE AREA SHORTLY AFTER
SUNRISE WED.
FOR THIS UPDATE...WILL MAKE UPWARD ADJUSTMENTS TO POPS FOR LATE
TONIGHT AND WED BASED ON THE VARIOUS NWP MESOSCALE MODEL SOLUTIONS
AS WELL AS THE 04/00Z NAM. HIGH TEMPS WED WILL BE NEARLY 15 DEGS F
OR SO BELOW NORMAL.
&&
.PREV DISCUSSION...FOR TOMORROW EXPECTING RELATIVELY HIGH RAIN
CHANCES AGAIN...BUT BY THURSDAY AND FRIDAY EXPECTING A DECREASE IN
RAIN CHANCES WITH SLIGHT CHANCE POPS FOR THE DESERTS/VALLEYS AND
CHANCE POPS FOR THE HIGHER TERRAIN. THROUGH THE REMAINDER OF THE
FORECAST PERIOD I KEPT THE INHERITED POP FORECAST WHICH BASICALLY
CALLS FOR A TYPICAL MONSOON FORECAST OF LOW END CHANCE POPS FOR THE
DESERTS/VALLEYS AND CHANCE TO LIKELY POPS FOR THE MOUNTAINS.
&&
.AVIATION...SCT-NMRS SHRA AND ISOLD-SCT TSRA THRU WEDNESDAY
AFTERNOON OR 05/00Z. WIND GUSTS TO NEAR 45 KTS AND MVFR CIGS/VSBYS
IN THE VICINITY OF STRONGEST TSRA. OTHERWISE...CLOUD DECKS MAINLY
5-8K FT AGL AND SURFACE WIND GENERALLY LESS THAN 10 KTS THRU
WEDNESDAY AFTERNOON. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
&&
.FIRE WEATHER...ABUNDANT MOISTURE IN COMBINATION WITH AN UPPER LEVEL
DISTURBANCE WILL BRING A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS
THROUGH WEDNESDAY. LOCALLY HEAVY RAINFALL AND STRONG...ERRATIC AND
GUSTY WINDS WILL OCCUR WITH THE STRONGER STORMS. HIGH TEMPERATURES
WEDNESDAY WILL BE WELL BELOW NORMAL. LESS ACTIVITY IS ON TAP
THURSDAY FOLLOWED BY A CHANCE OF MAINLY AFTERNOON AND EVENING
THUNDERSTORMS FRIDAY THROUGH TUESDAY.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
$$
WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS PUEBLO CO
310 PM MDT WED JUL 4 2012
.SHORT TERM...
(TONIGHT AND THURSDAY)
SFC DEW POINTS HAVE DROPPED OFF ACROSS THE PIKES PEAK REGION...WITH
READINGS IN THE LOWER 30S ACROSS THE LOWER ELEVATIONS OF EL PASO
COUNTY...AND MID TO UPPER 30S ACROSS TELLER COUNTY. CONVECTION
HAS BEEN SPARSE...AND SPC MESOANALYSIS SHOWING CAPE VALUES UNDER
100 J/KG FOR THIS REGION. DEW POINTS ARE A LITTLE HIGHER TO THE
SOUTH AND WEST WHERE CAPE VALUES ARE APPROACHING 1000 J/KG.
QUANDARY FOR THIS FORECAST PACKAGE IS WHAT TO DO WITH FLASH FLOOD
WATCH FOR THE WALDO CANYON BURN SCAR. SUCCESSIVE HIGH RES MODEL
RUNS...SUCH AS HRRR...AND RUC13 ARE STILL SHOWING VERY LITTLE
ACTIVITY ACROSS THE PIKES PEAK REGION. WINDS HAVE BEGUN TO SWITCH
AROUND FROM THE NORTHEAST TO EAST ACROSS EL PASO COUNTY...AND
MODELS DO BRING SOME LOWER 40 DEW POINTS BACK WESTWARD INTO THE
REGION BY 01-02Z (7-8 PM). BUT BY THIS TIME...PEAK HEATING IS LOST
WHICH SHOULD LIMIT STORM STRENGTH. HUNTING AROUND IN THE MOISTURE
PLUME FOR ANY EMBEDDED SHORTWAVES TO HELP ENHANCE -TSRA
COVERAGE...MOST OBVIOUS WAVE IS BACK ACROSS SOUTHERN AZ...AND IS
EASIEST TO TRACK IN THE PRESSURE FIELDS ON THE 1.5PV SURFACE...OR
IN THE UPPER LEVEL POT VORT FIELDS. THIS WAVE TRACKS TO THE NORTH
ACROSS AZ/UT FOR TOMORROW. COULD BE A WEAK FEATURE BACK ACROSS THE
4 CORNERS REGION ENHANCING TSRA COVERAGE ACROSS SW CO...BUT HARD
TO SAY FOR CERTAIN. BOTTOM LINE IS...WITH LOW LEVEL MOISTURE
LOOKING A LITTLE DRIER THAN YESTERDAY...THINK THREAT FOR FLASH
FLOODING HAS DECREASED...AND GUSTY OUTFLOW WIND POTENTIAL HAS
INCREASED. WILL WATCH LATEST RADAR TRENDS TOWARDS THE PACKAGE
ISSUANCE...AND WILL TAKE DOWN THE FLASH FLOOD WATCH FOR THE WALDO
CANYON BURN SCAR IF TRENDS CONTINUE AS THEY HAVE.
MEANWHILE...WITH PRECIP WATERS OUT WEST RUNNING UP TO 140 PERCENT OF
NORMAL...LOCALLY HEAVY RAIN STILL POSSIBLE...ESPECIALLY ALONG THE
CONTDVD...SO WILL CONTINUE TO MONITOR THIS AREA CLOSELY FOR
LOCALIZED RUN-OFF PROBLEMS.
CONVECTION MAY CONTINUE ACROSS PORTIONS OF THE SE PLAINS TONIGHT AS
LOW LEVEL JET INCREASES. SO WILL MAINTAIN AN AXIS OF HIGHER POPS
EAST OF THE I-25 CORRIDOR UNTIL 06Z...THEN TAPER IT BACK DURING
THE LATE NIGHT HOURS. WILL ALSO MAINTAIN SOME LOW POPS OUT WEST
UNDER THE MONSOON PLUME.
FOR THURSDAY...MODELS KEEP MAJORITY OF THE PRECIPITATION CONFINED TO
THE MOUNTAIN AREAS AS SOUTHERLY WINDS SPREAD BACK IN ACROSS ALL OF
THE SOUTHEAST PLAINS...PUSHING BOUNDARY TO THE NORTH OF THE REGION.
LOOKS LIKE DRIER AIR WILL BE PUSHING INTO EASTERN PORTIONS OF THE
FORECAST AREA ALONG LEADING EDGE OF PV LOBE...CURRENTLY LOCATED
ACROSS WRN TX...WHICH DECREASES PRECIP WATERS SOME FOR THE I-25
CORRIDOR AND SE PLAINS. THIS SHOULD DIMINISH HEAVY RAIN POTENTIAL
ACROSS THE PLAINS AND I-25 CORRIDOR...THOUGH WITH GUSTY SOUTHERLY
AFTERNOON WINDS...RHS MAY BE APPROACHING CRITICAL FIRE WEATHER
THRESHOLDS. THIS WILL CONTINUE TO BE MONITORED...BUT FOR NOW IT
REMAINS A LITTLE TOO MOIST FOR ANY FIRE WEATHER HIGHLIGHTS.
MEANWHILE...MTN AREAS...ESPECIALLY ALONG THE CONTINENTAL DIVIDE
WILL HAVE ANOTHER SHOT OF SOME LOCALLY HEAVY RAINFALL WITH
THUNDERSTORMS...SO WILL KEEP HIGHEST POPS OUT THAT WAY. -KT
.LONG TERM...
(THURSDAY NIGHT THROUGH WEDNESDAY)
EXTENDED RANGE MODELS ARE IN DECENT AGREEMENT WITH THE MID AND UPPER
LEVEL PATTERN. EARLY IN THE PERIOD H5 HIGH PRESSURE IS CENTERED OVER
THE CENTRAL PLAINS...BUT GRADUALLY RETROGRADES AND AMPLIFIES OVER
THE ROCKY MOUNTAIN REGION THIS WEEKEND. RIDGE BECOMES ENTRENCHED
OVER THE WESTERN U.S. BY THE MIDDLE OF NEXT WEEK.
AT THE SURFACE...DIFFERENCES BECOME MORE PRONOUNCED IN THE GFS AND
ECMWF. ECMWF CONTINUES ITS TREND OF HOLDING THE MID LEVEL MOISTURE
PLUME ALONG AND WEST OF THE CONTINENTAL DIVIDE AND INTO SOUTHEAST
WYOMING. ECMWF ALSO NOT AS FAST BRINGING SURFACE FRONT INTO THE CWA
AND FRONT APPEARS TO WOBBLE NORTH AND SOUTH OVER THE WEEKEND BEFORE
FINALLY PUSHING WELL SOUTH SUNDAY NIGHT. EASTERLY
UPSLOPE FLOW...INCREASING LOW LEVEL MOISTURE AND BETTER CHANCE
FOR RAINFALL ON THE PLAINS HOLDS OFF UNTIL MONDAY WITH THIS
SOLUTION. ON THE OTHER HAND...THE GFS HAS THE FRONT MOVING
THROUGH THE CWA FRIDAY AFTERNOON/EVENING WITH EASTERLY UPSLOPE
FLOW BRINGING LOW LEVEL MOISTURE INTO THE AREA THROUGH THE
WEEKEND.
FOR THIS FORECAST...I HAVE CUT BACK POPS ON THE SOUTHEAST PLAINS AND
AREAS ALONG THE SOUTHEASTERN MOUNTAINS. WILL CONTINUE THE HIGHEST
POPS IN THE MOUNTAINS...ESPECIALLY CONTINENTAL DIVIDE AND WESTWARD.
AFTER THIRTEEN CONSECUTIVE DAYS OF HIGH TEMPERATURES AT OR ABOVE 100
DEGREES IN PUEBLO...WE ARE READY FOR A BREAK IN THE VERY WARM TEMPS.
THE ARRIVAL OF THE FRONTAL BOUNDARY AND INCREASING AFTERNOON
CLOUDINESS SHOULD HELP BRING THAT STREAK TO AN END. EXPECT HIGHS IN
THE UPPER 80S TO AROUND 100 ON THE PLAINS...MID 80S IN THE HIGH
VALLEYS AND 60S AND 70S IN THE HIGHER ELEVATIONS FRIDAY. COOLER
TEMPS THIS WEEKEND AND EARLY NEXT WEEK WITH HIGHS IN THE 80S AND 90S
ON THE PLAINS...AND 50S AND 60S IN THE HIGHER ELEVATIONS.
WE ARE CONTINUING TO MONITOR POTENTIAL FOR SIGNIFICANT RAINFALL ON
THE WALDO CANYON BURN AREA. BEST CHANCES FOR SIGNIFICANT
PRECIPITATION WILL BE WHEN THE EASTERLY UPSLOPE FLOW SETS UP AT THE
SURFACE COMBINED WITH THE MID LEVEL MONSOON MOISTURE...PERHAPS THIS
WEEKEND AND EARLY NEXT WEEK. STARK
&&
.AVIATION...
VFR CONDITIONS EXPECTED AT TAF SITES THROUGH NEXT 24 HOURS. LATEST
MODEL RUNS KEEP MAJORITY OF THE -TSRA AWAY FROM THE TAF SITES...SO
WILL MAINTAIN VCTS FOR NOW. MAIN THREAT WILL BE BE GUSTY ERRATIC
WINDS IN THE 20-40 KT RANGE IF AN ISOLATED STORM CAN GET GOING. KALS
WILL HAVE THE BEST CHANCE OF -TSRA HITTING THE TAF SITE AND WILL
CONTINUE TO MONITOR THE LATEST RADAR TRENDS FOR POTENTIAL UPDATE
WITH A TEMPO GROUP. -TSRA CHANCES SHOULD DIMINISH AFTER
02Z...THOUGH A STRAY THUNDERSTORM OVER THE MTS AND FAR EASTERN
PLAINS MAY CONTINUE THROUGH THE NIGHT. ANOTHER ROUND OF -TSRA WILL
BE POSSIBLE ACROSS THE MOUNTAINS ON THURSDAY...POSSIBLY AFFECTING
THE KALS TAF SITE...THOUGH LOOKS LESS LIKELY TO IMPACT THE KPUB AND
KCOS TAF SITES AT THIS TIME. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31/40
AREA FORECAST DISCUSSION...UPDATED
NWS PUEBLO CO
1140 AM MDT WED JUL 4 2012
.UPDATE...
FRONTAL BOUNDARY HAS MOVED THROUGH EL PASO COUNTY WITH DEW POINTS
FALLING OFF INTO THE 30S BEHIND THIS BOUNDARY...A LITTLE DRIER
THAN MODELS SUGGESTED. IT APPEARS HRRR MAY HAVE THE BETTER HANDLE
ON THIS..AND IT HAS INDICATED THE LEAST AMOUNT OF QPF ACROSS THE
PIKES PEAK REGION ALL ALONG. THIS LEADS TO GREATER UNCERTAINTY ON THE
POTENTIAL FOR FLASH FLOODING ACROSS THE WALDO CANYON BURN SCAR.
WITH DRY SFC DEW POINTS...THIS SHOULD LIMIT CAPES TO A FEW HUNDRED
J/KG OR LESS. OF NOTE HOWEVER...WINDS ARE STILL PROGGED TO SHIFT
AROUND FROM THE NORTHEAST...PRECIP WATERS ARE RUNNING FROM 100-140
PERCENT OF NORMAL...AND STORM MOTIONS WILL BE SLOW. GIVEN THAT
LOCATIONS IN AND NEAR THE BURN SCAR RECEIVED .5 TO .8 OF RAINFALL
YESTERDAY...STILL CAN`T RULE OUT POTENTIAL FOR FLASH FLOODING
ALONG THE WALDO CANYON BURN SCAR...SO WILL MAINTAIN CURRENT FLASH
FLOOD WATCH FOR NOW. -KT
&&
.AVIATION...
ISOLATED TO SCATTERED THUNDERSTORMS WILL DEVELOP ACROSS THE
MOUNTAINS AND SPREAD INTO THE ADJACENT I-25 CORRIDOR THIS
AFTERNOON AND EVENING. CERTAINTY THAT -TSRA WILL AFFECT TAF SITES
IS STILL LOW...SO WILL MAINTAIN VCTS AT KALS...KCOS AND KPUB
DURING THE LATE AFTERNOON/EARLY EVENING...THOUGH HAVE INCLUDED A
VRB20G35KT FOR KCOS AND KPUB TO REFLECT POTENTIAL FOR -TSRA
OUTFLOWS. OTHERWISE...IF -TSRA DOES AFFECT TAF SITES...CIGS/VIS SHOULD
REMAIN IN THE VFR CATEGORY. A LITTLE BETTER MOISTURE IS OVER THE
KALS TAF SITE...SO DON`T THINK THAT GUSTY WIND POTENTIAL WILL BE
AS HIGH. -KT
&&
.PREV DISCUSSION... /ISSUED 343 AM MDT WED JUL 4 2012/
SHORT TERM...
(TODAY AND TONIGHT)
..FLASH FLOOD WATCH ISSUED FOR THE WALDO CANYON BURN SCAR...
CURRENTLY...
MOISTURE PLUME IS WELL DEFINED ACROSS THE SW CONUS. PWATS AT 00Z
WERE RUNNING FROM 100 TO 150% OF NORMAL ACROSS THE SW REGION. DWPTS
AT THIS HOUR...2 AM...WERE IN THE 50S ACROSS THE PLAINS...40S IN THE
VALLEYS AND 30S IN THE MTNS. 3H PRESS CHANGE CHART WAS SHOWING A
BOUNDARY MOVING SOUTH ACROSS WY EXTENDING INTO THE W DAKOTAS.
INFORMATION REGARDING THE FLOOD WATCH...
A FLASH FLOOD WATCH HAS BEEN ISSUED FOR THE WALDO BURN SCAR FOR
TODAY. THIS WATCH GOES INTO AFFECT AT NOON AND LAST UNTIL 8 PM MDT.
THE WATCH INCLUDE ZONE 81 AND ZONE 85. IT SHOULD BE NOTED THAT THE
ACTUAL BURN SCAR IS COMPLETELY WITHIN ZONE 81...BUT ANY FLOOD WAVE
THAT DEVELOPS WILL TRAVEL ACROSS THE WESTERN SECTIONS OF ZONE 85.
OBSERVATIONS FROM YESTERDAY SHOWED 0.80" OF RAIN FELL AT THE
THOMPSON RAWS (SE OF WOODLAND PARK ON HIWAY 24)...RAMPART HAD
0.45"...WHILE WEST MONUMENT HAS 0.22". CAVE OF THE WINDS HAD 0.11".
RADAR ESTIMATES WERE ABOUT 125-150% FROM OBSERVED VALUES. A REVIEW
OF INCIWEB.ORG DID NOT MENTION ANY INFORMATION REGARDING IF FLASH
FLOODING OCCURRED WITH THE ABOVE MENTIONED RAINFALL.
IF FLASH FLOODING WERE TO OCCUR TODAY...THE POPULATED AREAS WHICH
COULD BE HEAVILY IMPACTED INCLUDE HIGHWAY 24 FROM AROUND CASCADE TO
I-25...AND THE WESTERN SIDE OF OLD COLORADO CITY...THE CAMP CREEK
DRAINAGE (WEST COLORADO SPRINGS).
PLEASE NOTE THAT CAMP CREEK RUNS DIRECTLY DOWN THE CENTER OF NORTH
31ST STREET IN OLD COLORADO CITY...WHILE FOUNTAIN CREEK RUNS
DIRECTLY THROUGH DOWNTOWN MANITOU SPRINGS.
TODAY...
BOUNDARY DISCUSSED ABOVE SHOULD LIE ACROSS THE PIKES PEAK REGION BY
18Z TODAY...12 NOON. SHOWER AND THUNDERSTORMS WILL LIKELY DEVELOP
ACROSS THE HIGHER TRRN BY LATE MORNING AND INCREASE AS THE AFTERNOON
PROGRESSES. UNLIKE THE LAST FEW DAYS...STORMS WILL LIKELY NOT BE AS
OUTFLOW DOMINANT DUE TO THE INCREASED MOISTURE...AND THE HIRES MODEL
DATA DOES NOT SHOW STRONG OUTFLOW BOUNDARIES DEVELOPING WITH THE
STORMS. ADDITIONALLY...ACROSS THE PIKES PEAK REGION...THE SYNOPTIC
BOUNDARY WILL STALL OVER THIS REGION LATER TODAY AND WEAK
CONVERGENCE IS NOTED ACROSS THIS REGION UP TO 700 MB. WIND FLOW
WILL BE FROM AN EASTERLY COMPONENT (ALBEIT LIGHT) THROUGH 500 MB.
WITH THE UPSLOPE FLOW AND LESSER T/TD SPREADS...THE STORMS WILL HAVE
LESS OF A TENDENCY TO MOVE OFF THE HIGHER TRRN. LIKEWISE...HEAVIER
RAINS WILL BE POSSIBLE ACROSS THE BURN SCAR TODAY.
OVER THE REMAINDER OF THE REGION...SHOWER AND STORMS WILL LIKELY
OCCUR ACROSS ALL OF THE HIGHER TRRN TODAY. SIMULATIONS ARE SHOWING A
RATHER IMPRESSIVE BULLS EYE ACROSS THE CENTRAL MTNS...SO THE CHALK
BLUFFS WILL ALSO HAVE TO BE WATCHED FOR FLASH FLOODING TODAY. MORE
ISOLATED ACTIVITY WILL DEVELOP OVER THE PLAINS LATE IN THE
DAY...ESPECIALLY ALONG A TROUGH AXIS WHICH WILL EXTEND FROM
BURLINGTON CO TO NEAR LA JUNTA CO.
TONIGHT...
BEST CHANCE OF PRECIP DURING THE EARLY EVENING WILL LIE
ALONG THE SFC TROUGH OVER THE PLAINS. PRECIP WILL THEN DECREASE
LATER IN THE EVENING...BUT I DO NOT EXPECT IT TO COMPLETELY
DISSIPATE...AND ISOLD PRECIP WILL LIKELY LAST THROUGHOUT THE NIGHT
ACROSS THE ENTIRE CWA. /34
LONG TERM...
(THURSDAY THROUGH WEDNESDAY)
..MONSOON THUNDERSTORMS AND COOLER TEMPERATURES...
MODELS CONTINUE TO BE IN GOOD AGREEMENT THROUGH THE EXTENDED WITH
HIGH PRESSURE ENTRENCHED OVER THE MISSOURI VALLEY AND MONSOON
MOISTURE MOVING NORTH OUT OF THE DESERT SOUTHWEST.
ALL MODELS HAVE THE HIGH PRESSURE CENTERED OVER MISSOURI WITH
FAVORABLE SOUTHERLY FLOW ACROSS THE ROCKIES. MODEL ANALYSIS OF
PWAT INDICATES ABOVE NORMAL PWAT VALUES ALONG WITH SEVERAL
EMBEDDED DISTURBANCES WHICH WILL LEAD TO WIDESPREAD SHOWER AND
THUNDERSTORM ACTIVITY ACROSS THE REGION. THUNDERSTORMS ARE
FORECAST TO DEVELOP BY LATE MORNING ACROSS THE CONTINENTAL DIVIDE
AND HIGHER TERRAIN OF THE EASTERN MOUNTAINS BOTH THURSDAY AND
FRIDAY. COVERAGE AND INTENSITY WILL EXPAND BY THE EARLY AFTERNOON
WITH MOST OF THE WESTERN HALF OF THE CWA SEEING AT LEAST MODERATE
TO HEAVY RAINFALL UNDER THE THUNDERSTORMS. BARRIER PARALLEL FLOW
WILL KEEP STORM MOTIONS FROM SOUTH TO NORTH WITH LITTLE MOVEMENT
EXPECTED OFF THE MOUNTAINS INTO THE PLAINS. FOR NOW IT LOOKS LIKE
AREAS WEST OF I-25 WILL SEE THE BEST CHANCES FOR THUNDERSTORMS
THURSDAY AND FRIDAY. IN ADDITION TO LOCALLY HEAVY RAINFALL...GUST
OUTFLOW WINDS AND LIGHTNING ARE LIKELY. THE FLASH FLOOD THREAT
OVER THE WALDO CANYON FIRE BURN SCAR REMAINS ELEVATED AND WILL
HAVE TO BE MONITORED CLOSELY. TEMPERATURES WILL BE SLIGHTLY COOLER
BOTH AFTERNOONS WITH HIGHS IN THE 90S ACROSS THE REGION.
THE PATTERN BEGINS TO SHIFT THIS WEEKEND INTO EARLY NEXT WEEK. THE
HIGH PRESSURE OVER MISSOURI EXPANDS WESTWARD ACROSS COLORADO INTO
THE GREAT BASIN. THIS WILL FORCE THE MAIN MONSOONAL MOISTURE FLOW
WEST INTO THE GREAT BASIN. STILL EXPECT DECENT THUNDERSTORM
COVERAGE OVER THE MOUNTAINS SATURDAY AND SUNDAY HOWEVER THE QPF
AMOUNTS MAY BE LOWER THAN THOSE SEEN THURSDAY AND FRIDAY.
TEMPERATURES WILL REMAIN IN THE 90S FOR THE PLAINS FOR HIGHS THIS
WEEKEND.
THE HIGH PRESSURE WILL CONTINUE TO SHIFT WEST INTO UTAH WHERE IT
IS FORECAST TO STALL ON MONDAY. A STRONG DISTURBANCE ROTATING
AROUND THE HIGH WILL MOVE INTO COLORADO ON MONDAY AND SLOWLY DRIFT
SOUTHWEST AROUND THE HIGH THROUGH WEDNESDAY. THERE WILL BE PLENTY
OF MOISTURE ADVECTING NORTHWARD OUT OF THE SOUTHERN PLAINS INTO
COLORADO. THIS WILL HELP SET THE STAGE FOR WIDESPREAD SHOWER AND
THUNDERSTORM ACTIVITY ACROSS ALL OF SOUTHERN COLORADO FOR EARLY
NEXT WEEK. THE POTENTIAL EXISTS FOR PERIOD OF MODERATE TO HEAVY
RAINFALL OVER THE PLAINS...ESPECIALLY ALONG THE LEE SLOPES OF THE
EASTERN MOUNTAINS...PALMER DIVIDE AND RATON MESA. ALONG WITH THE
INCREASED POTENTIAL FOR RAINFALL...SOUTHEASTERLY UPSLOPE FLOW WILL
KEEP TEMPERATURES MORE MILD WITH 80S TO LOW 90S FOR THE PLAINS.
STAY TUNED AS WE MAY BE MOVING INTO A MORE WET PATTERN FOR ALL OF
SOUTHERN COLORADO. 88
AVIATION...
WITH THE MONSOON PLUME OVER THE REGION...AFTERNOON DIURNAL
CONVECTION IS LIKELY ACROSS THE 3 TAF SITES THIS AFTERNOON. BRIEF
PERIODS OF HEAVY RAIN ARE LIKELY WITH WINDS GUSTS TO 35KNT POSSIBLE.
OTHERWISE EXPECT VFR CONDITIONS NEXT 24H.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 8 PM MDT THIS EVENING FOR COZ081-085.
&&
$$
31/40
AREA FORECAST DISCUSSION
NWS NEW YORK NY
502 PM EDT WED JUL 4 2012
.SYNOPSIS...
A COLD FRONT WILL SLOWLY APPROACH FROM THE NORTHWEST THIS
EVENING...PRECEDED BY A TROUGH ACROSS THE AREA. THE FRONT WILL
CROSS THE AREA LATE TONIGHT. WEAK HIGH PRESSURE THEN BUILDS IN
THROUGH THURSDAY NIGHT. FAIR WEATHER ON FRIDAY WILL GIVE WAY TO
INCREASING HEAT AND A CHANCE OF THUNDERSTORMS SATURDAY. ADDITIONAL
STORMS MAY FIRE ON SUNDAY BEFORE A COOL FRONT EXITS LATE IN THE
DAY. THE PASSAGE OF THE FRONT WILL RESULT IN SEASONAL WEATHER
THROUGH THE BEGINNING OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
ISOLATED CONVECTION FINALLY BREAKING OUT ACROSS THE LOWER HUDSON
VALLEY AS A MID LEVEL CAPPING INVERSION IS OVERCOME BY DAYTIME
HEATING. CURRENT THINKING IT THAT COVERAGE WILL BE WIDELY SCT
THROUGH THIS EVENING AS A WEAK TROUGH PROGRESSES SE ACROSS THE
AREA AHEAD OF COLD FRONT DROPPING SE ACROSS THE GREAT LAKES. THE
LATTER OF WHICH WILL PASS THROUGH LATE TONIGHT AND USHER IN A
DRIER AIR MASS TOWARD MORNING.
AN UPPER JET STREAK PASSES TO THE NE TONIGHT AND SHOULD LIMIT THE
CONVECTION FROM BECOMING ORGANIZED. THE HRRR MODEL DOES SHOW SOME
CONSOLIDATION OF THESE AIR MASS THUNDERSTORMS ALONG THE PRE-
FRONTAL TROUGH THROUGH 00Z...DROPPING A LINE ACROSS THE NYC
METRO. THIS WILL NEED TO BE CLOSELY WATCHED...BUT SEEMS LIKE AN
OUTLIER AT THIS TIME.
A VERY MUGGY NIGHT IS IN STORE WITH DEW POINTS IN THE MID TO UPPER
60S. THE HEAT ADVISORY WILL REMAIN UP ACROSS NYC METRO AND
PORTIONS OF NE NJ THROUGH 8 PM.
OVERNIGHT LOWS WILL GENERALLY BE IN THE UPPER 60S TO LOWER
70S...WHICH IS SEVERAL DEGREES ABOVE NORMAL.
A MODERATE RISK OF RIP CURRENTS CONTINUES AT ATLANTIC OCEAN
BEACHES THROUGH THIS EVENING.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
HIGH PRESSURE AND NW FLOW WILL SEND A DRIER AIR MASS INTO THE
REGION ON THURSDAY...ALTHOUGH WITH THE OFFSHORE FLOW...HIGH
TEMPERATURES WILL ONLY BE SLIGHTLY COOLER. IN THE CASE OF COASTAL
LOCATIONS...IT ACTUALLY WILL BE SEVERAL DEGREES WARMER THAN WED.
MODELS ARE SLIGHTLY AT ODDS WITH THE MAGNITUDE OF THE CUTOFF LOW
THAT FORMS OFF THE COAST OF THE NOVA SCOTIA THU INTO THU NIGHT.
THE NAM IS A BIT DEEPER...SENDING THE FRONTAL BOUNDARY SOUTH
TOWARD THE MID ATLANTIC STATES. THE GFS IS WEAKER AND FARTHER
NORTH WITH THE BOUNDARY. IN EITHER CASE...SPLITTING THE DIFFERENCE
PRODUCES HIGHS IN THE UPPER 80S TO LOWER 90S. THE AIR MASS WILL
ALSO BE NOTICEABLY DRIER WITH DEW POINTS DROPPING INTO THE UPPER
50S IN THE AFTERNOON. THIS PRODUCES HEAT INDEX VALUES CLOSE TO IF
NOT LOWER THAN THE AMBIENT TEMPERATURE. THUS...THE HEAT ADVISORY
FOR NYC HAS BEEN CANCELLED FOR THU.
A DEEP-LAYERED NW FLOW WILL PROVIDE MAINLY CLEAR SKIES THU AND THU
NIGHT. LOW THU NIGHT WILL RETURN TO NEAR NORMAL LEVELS .
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
DRY NW FLOW ALOFT SO DRY WEATHER FRI. SIGNIFICANT DIFFERENCES IN
MODEL HIGH TEMPS. THE NAM IS THE COLDEST OF THE MAJOR SOLNS.
SUPPRESSION OF HEIGHTS S OF THE MARITIMES SEEMS TO BE THE MAIN
FACTOR. FOR THIS REASON...HAVE SIDED CLOSE TO THE WARMER 00Z ECMWF
AND 12Z GFS DATA DUE TO BETTER GLOBAL MODELING.
NAM CONTINUES AS AN OUTLIER FOR SAT. THE 00Z ECMWF IS HOT WITH RAW
DATA YIELDING HIGHS AROUND 100 NERN NJ. HAVE CONTINUED WITH THE
WARMER GUIDANCE FROM THE ECMWF AND GFS. ALL MODELS BRING CONVECTION
INTO THE CWA IN THE AFTN AND EVE AHEAD OF A COOL FRONT. IF THE
ECMWF/GFS VERIFY...INSTABILITY WILL ALLOW FOR SVR CHANCES.
THE FRONT LAGS BEHIND AND DOESN/T PASS TIL SUN AFTN/EVE. FOR THIS
REASON...HAVE MAINTAINED SLIGHT CHANCES FOR TSTMS AND BOOSTED TEMPS
TOWARDS THE HIGH END GFS ENSEMBLE DATA WITH RESIDUAL LLVL HOT AIR
TRAPPED IN THE REGION.
IT APPEARS THINGS SETTLE DOWN MON AND BEYOND AS THE FRONT REMAINS
STALLED S OF THE CWA. THIS WOULD RESULT IN FAIR WEATHER AND SEASONAL
TEMPS...AND THE FCST FOLLOWS THIS THINKING.
&&
.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
A WEAK TROUGH PERSISTS THIS AFTERNOON...WITH A WEAK COLD FRONT
PASSING THROUGH TONIGHT. HIGH PRESSURE BUILDS IN THE WAKE OF THE
FRONT. VFR CONDITIONS FOR THE PERIOD.
A TROUGH REMAINS IN PLACE OVER THE CITY TERMINALS...PRODUCING A
SWLY FLOW TO THE EAST...AND A WLY TO WNWLY FLOW TO THE WEST.
THERE REMAINS THE POSSIBILITY OF ISO TO SCT TSTORM THROUGH THIS
EVENING. HOWEVER...WITH LOW CONFIDENCE ON THE TIMING AND LOCATIONS
OF IMPACT...HAVE REFRAINED FROM MENTIONING IN TAFS. BEST CHC FOR
ANY DEVELOPMENT WILL BE ACROSS WESTERN TERMINALS WITH A WEAK UPPER
LEVEL DISTURBANCE APPROACHING.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR ANY ISOLATED
TSTORM DEVELOPMENT INTO THIS EVENING.
KLGA FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR ANY ISOLATED
TSTORM DEVELOPMENT INTO THIS EVENING. LOW CONFIDENCE ON SEABREEZE
MAKING IT TO KLGA BETWEEN 22Z AND 00Z.
KEWR FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR ANY ISOLATED
TSTORM DEVELOPMENT INTO THIS EVENING.
KTEB FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR ANY ISOLATED
TSTORM DEVELOPMENT INTO THIS EVENING.
KHPN FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR ANY ISOLATED
TSTORM DEVELOPMENT INTO THIS EVENING.
KISP FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR ANY TSTORM LATE
THIS AFTN. OCCASIONAL GUSTS PSBL THIS AFTN.
OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY...
.THU-FRI NIGHT...VFR.
.SAT-SUN...SLIGHT CHANCE OF TSTMS WITH MVFR OR LOWER CONDS.
.MON...VFR.
&&
.MARINE...
SUB SCA CONDITIONS EXPECTED THROUGH THE PERIOD WITH A WEAK
PRESSURE GRADIENT IN PLACE. UNDERCUT WAVEWATCH GUIDANCE BY 1 TO 2
FT THE NEXT 36 HOURS BASED ON CURRENT VALUES AT BUOYS AND THOSE
UPSTREAM.
WINDS AND SEAS WILL BE BLW SCA LVLS FRI-TUE. THERE WILL BE A CHANCE
OF TSTMS...SOME OF WHICH COULD BE STRONG TO SVR...SAT AFTN AND NGT.
THERE WILL BE ADDITIONAL CHANCES FOR TSTMS SUN UNTIL THE PASSAGE OF
A COLD FRONT.
&&
.HYDROLOGY...
ANY THUNDERSTORM THROUGH THIS EVENING WOULD BE ABLE TO PRODUCE
LOCALLY HEAVY RAINFALL WITH MINOR NUISANCE FLOODING.
&&
.TIDES/COASTAL FLOODING...
WATER LEVELS ARE FORECAST TO REMAIN JUST BELOW MINOR COASTAL FLOOD
BENCHMARKS AT THE TIME OF HIGH TIDE TONIGHT. THE ASTRONOMICAL HIGH
TIDE WILL BE LOWER BY A COUPLE OF TENTHS OF A FOOT FROM LAST
NIGHT.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NYZ072>075-176-
178.
NJ...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NJZ004-006-
103>108.
MARINE...NONE.
&&
$$
SYNOPSIS...JMC/DW
NEAR TERM...DW
SHORT TERM...DW
LONG TERM...JMC
AVIATION...SEARS
MARINE...JMC/DW
HYDROLOGY...JMC/DW
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
407 PM EDT WED JUL 4 2012
.SYNOPSIS...
A COLD FRONT WILL SLOWLY APPROACH FROM THE NORTHWEST THIS
EVENING...PRECEDED BY A TROUGH ACROSS THE AREA. THE FRONT WILL
CROSS THE AREA LATE TONIGHT. WEAK HIGH PRESSURE THEN BUILDS IN
THROUGH THURSDAY NIGHT. FAIR WEATHER ON FRIDAY WILL GIVE WAY TO
INCREASING HEAT AND A CHANCE OF THUNDERSTORMS SATURDAY. ADDITIONAL
STORMS MAY FIRE ON SUNDAY BEFORE A COOL FRONT EXITS LATE IN THE
DAY. THE PASSAGE OF THE FRONT WILL RESULT IN SEASONAL WEATHER
THROUGH THE BEGINNING OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
ISOLATED CONVECTION FINALLY BREAKING OUT ACROSS THE LOWER HUDSON
VALLEY AS A MID LEVEL CAPPING INVERSION IS OVERCOME BY DAYTIME
HEATING. CURRENT THINKING IT THAT COVERAGE WILL BE WIDELY SCT
THROUGH THIS EVENING AS A WEAK TROUGH PROGRESSES SE ACROSS THE
AREA AHEAD OF COLD FRONT DROPPING SE ACROSS THE GREAT LAKES. THE
LATTER OF WHICH WILL PASS THROUGH LATE TONIGHT AND USHER IN A
DRIER AIR MASS TOWARD MORNING.
AN UPPER JET STREAK PASSES TO THE NE TONIGHT AND SHOULD LIMIT THE
CONVECTION FROM BECOMING ORGANIZED. THE HRRR MODEL DOES SHOW SOME
CONSOLIDATION OF THESE AIR MASS THUNDERSTORMS ALONG THE PRE-
FRONTAL TROUGH THROUGH 00Z...DROPPING A LINE ACROSS THE NYC
METRO. THIS WILL NEED TO BE CLOSELY WATCHED...BUT SEEMS LIKE AN
OUTLIER AT THIS TIME.
A VERY MUGGY NIGHT IS IN STORE WITH DEW POINTS IN THE MID TO UPPER
60S. THE HEAT ADVISORY WILL REMAIN UP ACROSS NYC METRO AND
PORTIONS OF NE NJ THROUGH 8 PM.
OVERNIGHT LOWS WILL GENERALLY BE IN THE UPPER 60S TO LOWER
70S...WHICH IS SEVERAL DEGREES ABOVE NORMAL.
A MODERATE RISK OF RIP CURRENTS CONTINUES AT ATLANTIC OCEAN
BEACHES THROUGH THIS EVENING.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
HIGH PRESSURE AND NW FLOW WILL SEND A DRIER AIR MASS INTO THE
REGION ON THURSDAY...ALTHOUGH WITH THE OFFSHORE FLOW...HIGH
TEMPERATURES WILL ONLY BE SLIGHTLY COOLER. IN THE CASE OF COASTAL
LOCATIONS...IT ACTUALLY WILL BE SEVERAL DEGREES WARMER THAN WED.
MODELS ARE SLIGHTLY AT ODDS WITH THE MAGNITUDE OF THE CUTOFF LOW
THAT FORMS OFF THE COAST OF THE NOVA SCOTIA THU INTO THU NIGHT.
THE NAM IS A BIT DEEPER...SENDING THE FRONTAL BOUNDARY SOUTH
TOWARD THE MID ATLANTIC STATES. THE GFS IS WEAKER AND FARTHER
NORTH WITH THE BOUNDARY. IN EITHER CASE...SPLITTING THE DIFFERENCE
PRODUCES HIGHS IN THE UPPER 80S TO LOWER 90S. THE AIR MASS WILL
ALSO BE NOTICEABLY DRIER WITH DEW POINTS DROPPING INTO THE UPPER
50S IN THE AFTERNOON. THIS PRODUCES HEAT INDEX VALUES CLOSE TO IF
NOT LOWER THAN THE AMBIENT TEMPERATURE. THUS...THE HEAT ADVISORY
FOR NYC HAS BEEN CANCELLED FOR THU.
A DEEP-LAYERED NW FLOW WILL PROVIDE MAINLY CLEAR SKIES THU AND THU
NIGHT. LOW THU NIGHT WILL RETURN TO NEAR NORMAL LEVELS .
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
DRY NW FLOW ALOFT SO DRY WEATHER FRI. SIGNIFICANT DIFFERENCES IN
MODEL HIGH TEMPS. THE NAM IS THE COLDEST OF THE MAJOR SOLNS.
SUPPRESSION OF HEIGHTS S OF THE MARITIMES SEEMS TO BE THE MAIN
FACTOR. FOR THIS REASON...HAVE SIDED CLOSE TO THE WARMER 00Z ECMWF
AND 12Z GFS DATA DUE TO BETTER GLOBAL MODELING.
NAM CONTINUES AS AN OUTLIER FOR SAT. THE 00Z ECMWF IS HOT WITH RAW
DATA YIELDING HIGHS AROUND 100 NERN NJ. HAVE CONTINUED WITH THE
WARMER GUIDANCE FROM THE ECMWF AND GFS. ALL MODELS BRING CONVECTION
INTO THE CWA IN THE AFTN AND EVE AHEAD OF A COOL FRONT. IF THE
ECMWF/GFS VERIFY...INSTABILITY WILL ALLOW FOR SVR CHANCES.
THE FRONT LAGS BEHIND AND DOESN/T PASS TIL SUN AFTN/EVE. FOR THIS
REASON...HAVE MAINTAINED SLIGHT CHANCES FOR TSTMS AND BOOSTED TEMPS
TOWARDS THE HIGH END GFS ENSEMBLE DATA WITH RESIDUAL LLVL HOT AIR
TRAPPED IN THE REGION.
IT APPEARS THINGS SETTLE DOWN MON AND BEYOND AS THE FRONT REMAINS
STALLED S OF THE CWA. THIS WOULD RESULT IN FAIR WEATHER AND SEASONAL
TEMPS...AND THE FCST FOLLOWS THIS THINKING.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
A WEAK TROUGH PERSISTS THIS AFTERNOON...WITH A COLD FRONT PASSING
THROUGH TONIGHT. HIGH PRESSURE BUILDS IN THE WAKE OF THE FRONT. VFR
CONDITIONS FOR THE PERIOD.
A TROUGH REMAINS IN PLACE JUST WEST OF THE CITY TERMINALS...PRODUCING
A SWLY FLOW TO THE EAST...AND A WLY TO WNWLY FLOW TO THE WEST.
WINDS GENERALLY AROUND 10 KTS...WITH A FEW GUSTS IN THE COASTAL
TAF SITES. THE SEA BREEZE PASSAGE AT KJFK AND KISP WILL KEEP WINDS
MORE SLY FOR THE AFTN.
THERE REMAINS THE POSSIBILITY OF ISO TO SCT TSTORM LATE THIS AFTN
AFTER 20Z. HOWEVER...WITH LOW CONFIDENCE ON THE TIMING AND
LOCATIONS OF IMPACT...HAVE REFRAINED FROM MENTIONING IN TAFS. BEST
CHC FOR ANY DEVELOPMENT WILL BE ALONG THE SURFACE TROUGH EXTENDING
THROUGH THE CITY AND NE NJ.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR ANY TSTORM
DEVELOPMENT LATE THIS AFTN.
KLGA FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR ANY TSTORM
DEVELOPMENT LATE THIS AFTN. OCCASIONAL GUSTS PSBL THRU 23Z.
KEWR FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR ANY TSTORM
DEVELOPMENT LATE THIS AFTN.
KTEB FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR ANY TSTORM
DEVELOPMENT LATE THIS AFTN. OCCASIONAL GUSTS PSBL THRU 23Z.
KHPN FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR ANY TSTORM
DEVELOPMENT LATE THIS AFTN.
KISP FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR ANY TSTORM LATE
THIS AFTN. OCCASIONAL GUSTS PSBL THIS AFTN.
OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY...
.THU-FRI NIGHT...VFR.
.SAT-SUN...SLIGHT CHANCE OF TSTMS WITH MVFR OR LOWER CONDS.
.MON...VFR.
&&
.MARINE...
SUB SCA CONDITIONS EXPECTED THROUGH THE PERIOD WITH A WEAK
PRESSURE GRADIENT IN PLACE. UNDERCUT WAVEWATCH GUIDANCE BY 1 TO 2
FT THE NEXT 36 HOURS BASED ON CURRENT VALUES AT BUOYS AND THOSE
UPSTREAM.
WINDS AND SEAS WILL BE BLW SCA LVLS FRI-TUE. THERE WILL BE A CHANCE
OF TSTMS...SOME OF WHICH COULD BE STRONG TO SVR...SAT AFTN AND NGT.
THERE WILL BE ADDITIONAL CHANCES FOR TSTMS SUN UNTIL THE PASSAGE OF
A COLD FRONT.
&&
.HYDROLOGY...
ANY THUNDERSTORM THROUGH THIS EVENING WOULD BE ABLE TO PRODUCE
LOCALLY HEAVY RAINFALL WITH MINOR NUISANCE FLOODING.
&&
.TIDES/COASTAL FLOODING...
WATER LEVELS ARE FORECAST TO REMAIN JUST BELOW MINOR COASTAL FLOOD
BENCHMARKS AT THE TIME OF HIGH TIDE TONIGHT. THE ASTRONOMICAL HIGH
TIDE WILL BE LOWER BY A COUPLE OF TENTHS OF A FOOT FROM LAST
NIGHT.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NYZ072>075-176-
178.
NJ...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NJZ004-006-
103>108.
MARINE...NONE.
&&
$$
SYNOPSIS...JMC/DW
NEAR TERM...DW
SHORT TERM...DW
LONG TERM...JMC
AVIATION...SEARS
MARINE...JMC/DW
HYDROLOGY...JMC/DW
TIDES/COASTAL FLOODING...DW
AREA FORECAST DISCUSSION
NWS ALBANY NY
358 PM EDT WED JUL 4 2012
.SYNOPSIS...
A VERY WARM AND HUMID AIR MASS WILL BE OVER THE REGION THROUGH
THIS EVENING WITH SCATTERED SHOWERS AND THUNDERSTORMS. THE SHOWERS
WILL END BY LATE THIS EVENING AS A COLD FRONT SWEEPS THROUGH THE
REGION. DRY BUT VERY WARM WEATHER IS EXPECTED THURSDAY THROUGH
FRIDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 400 PM EDT...THE FORECAST AREA REMAINS IN THE WARM SECTOR
WITH THE COLD FRONT STILL WELL BACK ACROSS ONTARIO. TEMPS ACROSS
THE FA WERE GENERALLY IN THE LOWER 80S TO LOWER 90S WITH
DEWPOINTS IN THE MID TO UPPER 60S. ISOLD-SCT SHOWERS OR
THUNDERSTORMS ARE STILL EXPECTED THIS AFTERNOON...BUT A LACK OF A
FORCING OR LIFTING MECHANISM...COUPLED WITH POOR MID LEVEL LAPSE
RATES...AND A STRONG CAPPING INVERSION BETWEEN 600-700 HPA
/EVIDENT ON THE 12Z KALB SOUNDING/...SHOULD LIMIT THE COVERAGE AND
INTENSITY OF STORMS. WE WILL MENTION SOME LOCALLY HEAVY RAINFALL
WITH PWATS ON THE RISE TO 1.25-1.50". THE LATEST HRRR STILL SHOWS
SOME ISOLD CONVECTION TO SCATTERED CONVECTION WITHIN THE FORECAST
AREA WITH THE GREATEST CONCENTRATION OF CELLS AROUND 22Z WITH ALL
OF THE CONVECTION OVER BY 04Z.
FROM LATE THIS EVENING THROUGH THURSDAY EXPECT DRY CONDITIONS WITH
DECREASING HUMIDITY AS THE FRONT WILL BE WELL SOUTH OF THE FA BY
12Z THU. SKIES WILL BECOME MAINLY CLEAR LATER TONIGHT WITH PLENTY
OF SUN ON THURSDAY. EXPECT LOWS TONIGHT IN THE MID 50S TO MID 60S
WITH HIGHS ON THURSDAY IN THE UPPER 70S TO AROUND 90.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
A RIDGE OF HIGH PRESSURE IS EXPECTED TO BUILD ACROSS THE FA
THURSDAY NIGHT AND FRIDAY AND START TO BREAKDOWN AS A COLD FRONT
DROPS SOUTHEAST INTO THE SAINT LAWRENCE VALLEY LATE FRIDAY NIGHT.
DRY CONDITIONS ARE EXPECTED DURING THE ENTIRE SHORT TERM PERIOD.
EXPECT MAINLY CLEAR SKIES THURSDAY NIGHT THROUGH FRIDAY EVENING
WITH INCREASING CLOUDS DURING THE SECOND HALF OF FRIDAY NIGHT
AHEAD OF THE COLD FRONT.
EXPECT LOWS THURSDAY NIGHT IN THE 50S TO LOWER 60S WITH SOME UPPER
40S POSSIBLE ACROSS FAR NORTHERN PORTIONS OF THE WESTERN
ADIRONDACKS. HIGHS ON FRIDAY ARE EXPECTED TO BE IN THE MID 80S TO
LOWER 90S WITH HUMIDITY LEVELS STARTING TO INCREASE AGAIN
ESPECIALLY BY LATE IN THE DAY. LOWS FRIDAY NIGHT ARE EXPECTED TO
BE IN THE 60S TO AROUND 70.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
HAVE POPULATED MOST FIELDS WITH A 50/50 BLEND OF 12Z/04 GMOS AND
12Z/04 HPC MOS.
SATURDAY-SATURDAY NIGHT...MOST 12Z/04 DETERMINISTIC MODELS HINT AT A
COLD FRONT SLOWLY SETTLING SOUTHWARD DURING SATURDAY...ALTHOUGH
THERE ARE SOME TIMING DIFFERENCES...WITH SOME MODELS HINTING AT A
SLIGHTLY EARLIER FROPA...WITH LESS CONVECTIVE CHANCES. AT THIS
TIME...WILL CONTINUE WITH CHC POPS FOR SCATTERED
SHOWERS/TSTMS...ALTHOUGH BEST CHC MAY SHIFT INTO CENTRAL AND
SOUTHERN AREAS DURING THE AFTERNOON HOURS. DEPENDING ON TIMING OF
FROPA...SATURDAY COULD BE QUITE WARM TO HOT...ESP ACROSS SOUTHERN
AREAS. HAVE INDICATED MAX TEMPS OF 85-90 IN MOST VALLEYS...EXCEPT
FOR 90-95 ACROSS THE MID HUDSON VALLEY REGIONS...WITH UPPER
70S/LOWER 80S ACROSS HIGHER ELEVATIONS WITHIN THE SOUTHERN
ADIRONDACKS. FOR SAT NT...WE EXPECT THE FRONTAL BOUNDARY TO MOVE
SOUTH OF THE REGION. WILL KEEP ISOLATED TO SCATTERED SHOWERS/TSTMS
THROUGH MIDNIGHT...WITH GREATEST POPS ACROSS SOUTHERN
AREAS...DECREASING FROM N TO S OVERNIGHT. FOR MINS...EXPECT
LOWER/MID 60S IN VALLEYS...AND 55-60 ACROSS THE SOUTHERN
ADIRONDACKS. IT MAY REMAIN SLIGHTLY WARMER...GENERALLY MID
60S...ACROSS THE MID HUDSON VALLEY REGION.
SUNDAY-WEDNESDAY...AT THIS TIME...MOST GUIDANCE IS INDICATING A
PERSISTENT W/NW MID AND UPPER LEVEL CONFLUENT FLOW ACROSS THE GREAT
LAKES AND NORTHEAST STATES...DEFLECTING MUCH OF THE HEAT AND
INSTABILITY...AS WELL AS MOISTURE...WELL SOUTH AND WEST OF THE
REGION. WE HAVE THEREFORE INDICATED DRY CONDITIONS THROUGH THE
PERIOD...WITH TEMPS AVERAGING NEAR TO SLIGHTLY ABOVE SEASONAL
LEVELS. THIS TRANSLATES INTO MAX TEMPS OF 80-85 IN MOST
VALLEYS...AND 75-80 ACROSS HIGHER ELEVATIONS...WITH OVERNIGHT MINS
GENERALLY IN THE 50S TO LOWER 60S...ALTHOUGH SOME UPPER 40S WILL BE
POSSIBLE ACROSS HIGHER ELEVATIONS WITHIN THE SOUTHERN ADIRONDACKS.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
A WEAK COLD FRONT...AND ITS ASSOCIATED UPPER LEVEL DISTURBANCE WILL
MOVE ACROSS ERN NY AND NEW ENGLAND THIS AFTERNOON INTO THE OVERNIGHT
PERIOD. HIGH PRESSURE WILL BUILD IN FROM SOUTHWEST QUEBEC FOR
THURSDAY.
VFR CONDITIONS ARE EXPECTED PRIOR TO MIDNIGHT...AS THE REGION WILL
BE IN A WARM SECTOR...BEFORE A WEAK COLD FRONT MOVES FROM NW TO SE
THRU THE AREA PRIOR TO MIDNIGHT. SOME ISOLD-SCT SHOWERS...AND A FEW
THUNDERSTORMS WILL DEVELOP IN ADVANCE OF THE BOUNDARY...AND A
SHORT-WAVE MOVING ACROSS NEW ENGLAND...GENERALLY BTWN 21Z-03Z. HAVE
INCLUDED A VCSH AT KGFL AROUND 00Z...BUT SINCE THE COVERAGE IS SMALL
IN TERMS OF ANY POTENTIAL SHOWERS/THUNDERSTORMS...WILL KEEP IT OUT
OF THE TAFS. A STRONG MID LEVEL CAP WILL ALSO INHIBIT WIDESPREAD
CONVECTIVE DEVELOPMENT.
AS THE FRONT MOVES SOUTHEAST...THE SKIES WILL CLEAR...BUT DEEPER
MIXING IS NOT EXPECTED UNTIL DAYBREAK THU. MAINLY CLEAR SKIES...AND
LIGHT TO CALM WINDS WILL ALLOW SOME RADIATIONAL MIST/FOG TO FORM AT
KGFL/KPSF/KPOU WITH MVFR/IFR CONDITIONS. THE BEST CHC FOR IFR MIST
IN THE 07Z-12Z TIME FRAME WILL BE AT KGFL/KPOU.
THE WINDS SHOULD PICK UP SHORTLY AFTER SUNRISE FROM THE N/NW AT
AROUND 10 KTS. ANY MIST OR FOG WILL DISSIPATE QUICKLY THEREAFTER.
A FEW-SCT FAIR CUMULUS WILL LIKELY FORM IN THE LATE MORNING OR
AFTERNOON.
THE WINDS WILL BE SOUTHWEST-NORTHWEST AT 7-12 KTS THIS AFTERNOON
WITH A FEW GUTS AROUND 20 KTS AT KALB. EXPECT THE WINDS TO BECOME
LIGHT TO CALM PRIOR TO MIDNIGHT...AND INCREASE FROM THE N/NW AT
AROUND 10 KTS AFTER 12Z/THU.
OUTLOOK...
THU...VFR. NO SIG WX.
THU NGT...MAINLY VFR EXCEPT POSSIBLE MVFR/IFR IN FOG/BR.
FRI-FRI NGT...VFR. NO SIG WX.
SAT...VFR/MVFR...CHC SHRA/TSRA.
SUN-MON...VFR...NO SIG WX.
&&
.FIRE WEATHER...
A VERY WARM AND HUMID AIR MASS WILL BE OVER THE REGION THROUGH
THIS EVENING WITH SCATTERED SHOWERS AND THUNDERSTORMS. THE SHOWERS
WILL END BY LATE THIS EVENING AS A COLD FRONT SWEEPS THROUGH THE
REGION. DRY BUT VERY WARM WEATHER IS EXPECTED THURSDAY THROUGH
FRIDAY.
RELATIVE HUMIDITIES ARE EXPECTED TO RISE TO 85 TO 100 PERCENT
TONIGHT...DROP TO 35 TO 50 PERCENT THURSDAY...RISE TO 85 TO 100
PERCENT THURSDAY NIGHT AND DROP TO 35 TO 50 PERCENT AGAIN FRIDAY.
WINDS WILL BE NORTHWEST AT 5 TO 15 MPH TONIGHT...NORTH TO
NORTHWEST AT 5 TO 10 MPH ON THURSDAY...NORTHWEST AROUND 5 MPH ON
THURSDAY NIGHT...AND WEST AT 5 TO 10 MPH ON FRIDAY.
&&
.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED DURING THE NEXT 5 DAYS ON
THE MAIN STEM RIVERS...WITH MAINLY DRY WEATHER EXPECTED AND ABOVE
NORMAL TEMPERATURES.
RAINFALL THROUGH THIS EVENING AND AGAIN SATURDAY AND SATURDAY
EVENING WILL BE SPOTTY AS IT WILL FALL FROM ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS. ALTHOUGH LOCALLY HEAVY RAIN IS
POSSIBLE WHERE THUNDERSTORMS OCCUR...OVERALL THERE SHOULD BE
LITTLE OR NO IMPACT ON AREA RIVERS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...11/WASULA
NEAR TERM...11/WASULA
SHORT TERM...11
LONG TERM...KL
AVIATION...WASULA
FIRE WEATHER...11
HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS ALBANY NY
158 PM EDT WED JUL 4 2012
.SYNOPSIS...
A VERY WARM AND HUMID AIR MASS WILL BE OVER THE REGION TODAY...AND A
FRONTAL BOUNDARY WILL MOVE SOUTHEASTWARD ACROSS THE REGION LATE THIS
AFTERNOON AND EVENING. THIS WILL RESULT IN SCATTERED SHOWERS AND
THUNDERSTORMS...MAINLY THIS AFTERNOON AND EVENING. THE SHOWERS
WILL END BY LATE THIS EVENING. DRY BUT VERY WARM WEATHER IS
EXPECTED THURSDAY THROUGH FRIDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 130 PM EDT...THE FORECAST AREA REMAINS IN THE WARM SECTOR
WITH THE COLD FRONT STILL WELL BACK ACROSS ONTARIO. TEMPS ACROSS
THE FA WERE GENERALLY IN THE UPPER 70S TO MID 80S WITH DEWPOINTS
IN THE MID TO UPPER 60S. THERE COULD BE SOME ISOLD-SCT SHOWERS OR
THUNDERSTORMS IN THE AFTERNOON...BUT A LACK OF A FORCING OR
LIFTING MECHANISM...COUPLED WITH POOR MID LEVEL LAPSE RATES...AND
A STRONG CAPPING INVERSION BETWEEN 600-700 HPA /EVIDENT ON THE 12Z
KALB SOUNDING/...SHOULD LIMIT THE COVERAGE AND INTENSITY OF
STORMS. WE WILL MENTION SOME LOCALLY HEAVY RAINFALL WITH PWATS ON
THE RISE TO 1.25-1.50". THE LATEST HRRR SHOWS SOME ISOLD
CONVECTION TO SCATTERED CONVECTION WITHIN THE FORECAST AREA WITH
THE GREATEST CONCENTRATION OF CELLS AROUND 22Z WITH ALL OF THE CONVECTION
OVER BY 03Z.
HIGH TEMPS TODAY WILL BE IN THE 80S TO LOWER 90S AND DEWPOINTS
WILL BE IN THE 60S. THIS WILL RESULT IN MAXIMUM HEAT INDICES FOR
TODAY OF AROUND 97 DEGREES IN THE MID HUDSON VALLEY...AND MID 80S
TO LOWER 90S ELSEWHERE...SO NO HEAT ADVISORIES CONTEMPLATED AT
THIS TIME.
FROM LATE THIS EVENING THROUGH THURSDAY EXPECT DRY CONDITIONS WITH
DECREASING HUMIDITY AS THE FRONT WILL BE WELL SOUTH OF THE FA BY
12Z THU. SKIES WILL BECOME MAINLY CLEAR LATER TONIGHT WITH PLENTY
OF SUN ON THURSDAY. EXPECT LOWS TONIGHT IN THE MID 50S TO MID 60S
WITH HIGHS ON THURSDAY IN THE UPPER 70S TO AROUND 90.
&&
.SHORT TERM /THURSDAY NIGHT/...
MAINLY CLEAR AND SEASONABLE TEMPS FOR THURSDAY NIGHT WITH LOWS IN
THE 50S TO LOWER 60S.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
WARMER AIR WILL RETURN TO THE REGION AGAIN ON FRIDAY AS 850 MB TEMPS
APPROACH +20 DEG CELSIUS BY LATE IN THE DAY. THIS WILL RESULT IN
HIGHS FRIDAY IN THE MID 80S TO LOWER 90S. DEWPOINTS WILL BEGIN TO
INCREASE AGAIN ON FRIDAY...BUT OVERALL IT WONT BE VERY HUMID WITH
DEWPOINTS ONLY RISING INTO THE UPPER 50S AND LOWER 60S BY LATE IN
THE DAY.
FRIDAY NIGHT STARTS OUT WITH A COLD FRONT GRADUALLY APPROACHING
THE AREA FROM SOUTHEAST CANADA. VARIOUS SOURCES OF MODEL GUIDANCE
SHOWING AT LEAST LOOSE AGREEMENT WITH THIS FEATURE...ALTHOUGH THE
GFS DEPICTS MULTIPLE WEAK BOUNDARIES MOVING THROUGH. THE ECMWF AND
TO A CERTAIN EXTENT THE GGEM HAVE BEEN FAIRLY CONSISTENT WITH
PUSHING A MAIN FRONTAL BOUNDARY THROUGH THE AREA ON SATURDAY INTO
SATURDAY EVENING. VERY WARM AIR ALOFT WILL BE OVER THE REGION
FRIDAY NIGHT...AND SHOULD START TO MOVE EAST ON SATURDAY
COINCIDENT WITH THE FRONT. WHILE CLOUDS SHOULD INCREASE...MOISTURE
POOLING AHEAD OF THE BOUNDARY COMBINED WITH SOME INSTABILITY COULD
TRIGGER SCATTERED SHOWERS AND THUNDERSTORMS SO HAVE INDICATED LOW
CHANCE POPS.
IT WILL BE WARM AND HUMID THROUGH SATURDAY...BEFORE A PUSH OF A LESS
HUMID AND COOLER AIR MASS MOVES IN FOR SUNDAY. TEMPS LOOK TO COOL
BACK TO NEAR NORMAL READINGS WITH COMFORTABLE HUMIDITY LEVELS SUNDAY
AND MONDAY WITH A NORTHWEST FLOW REGIME AND WEAK HIGH PRESSURE IN
CONTROL.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
A WEAK COLD FRONT...AND ITS ASSOCIATED UPPER LEVEL DISTURBANCE WILL
MOVE ACROSS ERN NY AND NEW ENGLAND THIS AFTERNOON INTO THE OVERNIGHT
PERIOD. HIGH PRESSURE WILL BUILD IN FROM SOUTHWEST QUEBEC FOR
THURSDAY.
VFR CONDITIONS ARE EXPECTED PRIOR TO MIDNIGHT...AS THE REGION WILL
BE IN A WARM SECTOR...BEFORE A WEAK COLD FRONT MOVES FROM NW TO SE
THRU THE AREA PRIOR TO MIDNIGHT. SOME ISOLD-SCT SHOWERS...AND A FEW
THUNDERSTORMS WILL DEVELOP IN ADVANCE OF THE BOUNDARY...AND A
SHORT-WAVE MOVING ACROSS NEW ENGLAND...GENERALLY BTWN 21Z-03Z. HAVE
INCLUDED A VCSH AT KGFL AROUND 00Z...BUT SINCE THE COVERAGE IS SMALL
IN TERMS OF ANY POTENTIAL SHOWERS/THUNDERSTORMS...WILL KEEP IT OUT
OF THE TAFS. A STRONG MID LEVEL CAP WILL ALSO INHIBIT WIDESPREAD
CONVECTIVE DEVELOPMENT.
AS THE FRONT MOVES SOUTHEAST...THE SKIES WILL CLEAR...BUT DEEPER
MIXING IS NOT EXPECTED UNTIL DAYBREAK THU. MAINLY CLEAR SKIES...AND
LIGHT TO CALM WINDS WILL ALLOW SOME RADIATIONAL MIST/FOG TO FORM AT
KGFL/KPSF/KPOU WITH MVFR/IFR CONDITIONS. THE BEST CHC FOR IFR MIST
IN THE 07Z-12Z TIME FRAME WILL BE AT KGFL/KPOU.
THE WINDS SHOULD PICK UP SHORTLY AFTER SUNRISE FROM THE N/NW AT
AROUND 10 KTS. ANY MIST OR FOG WILL DISSIPATE QUICKLY THEREAFTER.
A FEW-SCT FAIR CUMULUS WILL LIKELY FORM IN THE LATE MORNING OR
AFTERNOON.
THE WINDS WILL BE SOUTHWEST-NORTHWEST AT 7-12 KTS THIS AFTERNOON
WITH A FEW GUTS AROUND 20 KTS AT KALB. EXPECT THE WINDS TO BECOME
LIGHT TO CALM PRIOR TO MIDNIGHT...AND INCREASE FROM THE N/NW AT
AROUND 10 KTS AFTER 12Z/THU.
OUTLOOK...
THU...VFR. NO SIG WX.
THU NGT...MAINLY VFR EXCEPT POSSIBLE MVFR/IFR IN FOG/BR.
FRI-FRI NGT...VFR. NO SIG WX.
SAT...VFR/MVFR...CHC SHRA/TSRA.
SUN-MON...VFR...NO SIG WX.
&&
.FIRE WEATHER...
RELATIVE HUMIDITIES ARE EXPECTED TO LOWER TO BETWEEN 40 TO 55
PERCENT TODAY...AND RISE TO BETWEEN 90 TO 100 PERCENT TONIGHT.
WINDS WILL BECOME WEST TO NORTHWEST TODAY AT 10 TO 15 MPH WITH GUSTS
UP TO 25 MPH POSSIBLE. EVEN HIGHER GUSTS MAY OCCUR IN THUNDERSTORMS
THIS AFTERNOON AND EVENING. THE WINDS WILL DIMINISH TO 5 TO 10 MPH
TONIGHT.
&&
.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED DURING THE NEXT 5 DAYS ON
THE MAIN STEM RIVERS...WITH MAINLY DRY WEATHER EXPECTED AND ABOVE
NORMAL TEMPERATURES. LAST NIGHTS RAINFALL HAD LITTLE IF ANY IMPACT
ON AREA RIVERS AND STREAMS.
THE BEST CHANCE FOR RAINFALL WILL BE THIS AFTERNOON AND
EVENING...AND AGAIN SATURDAY AND SATURDAY NIGHT. IN BOTH CASES THE
RAINFALL WILL IN THE FORM OF SCATTERED SHOWERS AND THUNDERSTORMS.
ALTHOUGH LOCALLY HEAVY RAIN IS POSSIBLE WHERE THUNDERSTORMS
OCCUR...OVERALL THERE SHOULD BE LITTLE OR NO IMPACT ON AREA RIVERS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...GJM/WASULA
NEAR TERM...GJM/11/WASULA
SHORT TERM...GJM
LONG TERM...JPV
AVIATION...WASULA
FIRE WEATHER...GJM
HYDROLOGY...GJM
AREA FORECAST DISCUSSION
NWS ALBANY NY
1032 AM EDT WED JUL 4 2012
.SYNOPSIS...
A VERY WARM AND HUMID AIR MASS WILL BE OVER THE REGION TODAY...AND A
FRONTAL BOUNDARY WILL MOVE SOUTHEASTWARD ACROSS THE REGION LATE THIS
AFTERNOON AND EVENING. THIS WILL RESULT IN SCATTERED SHOWERS AND
THUNDERSTORMS...MAINLY THIS AFTERNOON AND EVENING. THE SHOWERS
WILL END BY LATE THIS EVENING. DRY BUT VERY WARM WEATHER IS
EXPECTED THURSDAY THROUGH FRIDAY.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AS OF 1025 AM EDT...THE FORECAST AREA IS IN A WARM SECTOR. THE
COLD FRONT REMAINS WELL UPSTREAM OF THE FORECAST AREA. THE AREA IS
IN A WARM AND HUMID AIR MASS WHERE DEWPTS HAVE RISEN IN THE 60S TO
L70S. THERE COULD BE SOME ISOLD-SCT SHOWERS OR THUNDERSTORMS IN
THE AFTERNOON...BUT A LACK OF A FORCING OR LIFTING
MECHANISM...COUPLED WITH POOR MID LEVEL LAPSE RATES...AND A STRONG
CAPPING INVERSION BETWEEN 600-700 HPA /EVIDENT ON THE 12Z KALB
SOUNDING/ ...SHOULD LIMIT THE COVERAGE AND INTENSITY OF STORMS. WE
WILL MENTION SOME LOCALLY HEAVY RAINFALL WITH PWATS ON THE RISE TO
1.25-1.50". THE LATEST HRRR SHOWS SOME ISOLD CONVECTION...MAINLY
SOUTH OF THE CAPITAL REGION...WHEREAS THE NAM HAS LITTLE OR NO
ACTIVITY.
ANY SHOWER/THUNDERSTORM ACTIVITY SHOULD DIMINISH BY
SUNSET...BEFORE THE INDEPENDENCE DAY CELEBRATIONS.
HIGH TEMPS TODAY WILL BE IN THE 80S TO LOWER 90S AND DEWPOINTS
WILL BE IN THE 60S. THIS WILL RESULT IN MAXIMUM HEAT INDICES FOR
TODAY OF AROUND 97 DEGREES IN THE MID HUDSON VALLEY...AND MID 80S
TO LOWER 90S ELSEWHERE...SO NO HEAT ADVISORIES CONTEMPLATED AT
THIS TIME.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH THURSDAY NIGHT/...
SOMEWHAT COOLER BUT DEFINITELY LESS HUMID AIR WILL BEGIN TO FILTER
INTO THE REGION LATE TONIGHT AND THURSDAY AS A DRIER AIRMASS DROPS
OUT OF CANADA. LOWS TONIGHT WILL STILL BE WARM HOWEVER...WITH
READINGS ONLY FALLING INTO THE UPPER 50S AND 60S. ON THURSDAY HIGHS
WILL BE IN THE UPPER 70S TO 90...BUT DEWPOINTS WILL BE DECREASING
INTO THE MID 50S TO AROUND 60 BY LATE IN THE DAY. EXPECT MOSTLY
SUNNY SKIES ON THURSDAY.
MAINLY CLEAR AND SEASONABLE TEMPS FOR THURSDAY NIGHT WITH LOWS IN
THE 50S TO LOWER 60S.
WARMER AIR WILL RETURN TO THE REGION AGAIN ON FRIDAY AS 850 MB TEMPS
APPROACH +20 DEG CELSIUS BY LATE IN THE DAY. THIS WILL RESULT IN
HIGHS FRIDAY IN THE MID 80S TO LOWER 90S. DEWPOINTS WILL BEGIN TO
INCREASE AGAIN ON FRIDAY...BUT OVERALL IT WONT BE VERY HUMID WITH
DEWPOINTS ONLY RISING INTO THE UPPER 50S AND LOWER 60S BY LATE IN
THE DAY.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
THE PERIOD STARTS OUT WITH A COLD FRONT GRADUALLY APPROACHING THE
AREA FROM SOUTHEAST CANADA. VARIOUS SOURCES OF MODEL GUIDANCE
SHOWING AT LEAST LOOSE AGREEMENT WITH THIS FEATURE...ALTHOUGH THE
GFS DEPICTS MULTIPLE WEAK BOUNDARIES MOVING THROUGH. THE ECMWF AND
TO A CERTAIN EXTENT THE GGEM HAVE BEEN FAIRLY CONSISTENT WITH
PUSHING A MAIN FRONTAL BOUNDARY THROUGH THE AREA ON SATURDAY INTO
SATURDAY EVENING. VERY WARM AIR ALOFT WILL BE OVER THE REGION FRIDAY
NIGHT...AND SHOULD START TO MOVE EAST ON SATURDAY COINCIDENT WITH
THE FRONT. WHILE CLOUDS SHOULD INCREASE...MOISTURE POOLING AHEAD OF
THE BOUNDARY COMBINED WITH SOME INSTABILITY COULD TRIGGER SCATTERED
SHOWERS AND THUNDERSTORMS SO HAVE INDICATED LOW CHANCE POPS.
IT WILL BE WARM AND HUMID THROUGH SATURDAY...BEFORE A PUSH OF A LESS
HUMID AND COOLER AIR MASS MOVES IN FOR SUNDAY. TEMPS LOOK TO COOL
BACK TO NEAR NORMAL READINGS WITH COMFORTABLE HUMIDITY LEVELS SUNDAY
AND MONDAY WITH A NORTHWEST FLOW REGIME AND WEAK HIGH PRESSURE IN
CONTROL.
SOME SHORT WAVE ENERGY AND REINFORCING COOL FRONT MAY AFFECT THE
AREA MONDAY NIGHT INTO TUESDAY. WITH LIMITED MOISTURE WILL ONLY
MENTION SLIGHT CHANCE POPS FOR NOW. TEMPS SHOULD CONTINUE TO BE NEAR
NORMAL INTO THE MIDDLE OF NEXT WEEK WITH NO SIGNIFICANT RAINFALL.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS WILL PREVAIL AT THE KALB/KPOU/KGFL/KPSF TAF SITES
THROUGH THE DAYLIGHT HOURS. SOMEWHAT LOW SCT-BKN STATUS DECK MAINLY
EAST AND WEST OF THE HUDSON VALLEY...SHOULD LIFT BY MID MORNING ONLY
SCT CU DEVELOPING. ISOLATED TO WIDELY SCATTERED SHOWERS AND
THUNDERSTORMS ARE POSSIBLE DURING THE AFTERNOON/EVENING HOURS AS A
WEAK COLD FRONT APPROACHES...HOWEVER A DEVELOPING MID LEVEL CAP
SHOULD PRECLUDE MORE WIDESPREAD CONVECTIVE DEVELOPMENT. THUS...THE
PROBABILITY REMAINS TOO LOW TO INCLUDE ANY MENTION IN CURRENT TAFS.
MAINLY CLEAR SKIES AND LIGHT WINDS TONIGHT COULD RESULT IN SOME
RADIATION FOG FORMATION. MAIN TERMINALS FOR POSSIBLE RESTRICTIONS
ARE KGFL/PSF. MITIGATING FACTOR WILL BE DRYING OF THE AIR MASS ABOVE
THE BOUNDARY LAYER IN WAKE OF THE WEAK COLD FRONT. WILL MENTION MVFR
VSBYS FOR NOW DUE TO LOW CONFIDENCE IN MORE PREVALENT/DENSE FOG
FORMATION.
LIGHT AND VARIABLE WINDS WILL BECOME WEST-NORTHWEST LATER THIS
MORNING AROUND 10-12 KT WITH SOME GUSTS NEAR 20 KT ESPECIALLY AT
KALB/KPSF. WIND SPEEDS WILL DECREASE AFTER DARK.
OUTLOOK...
THU...VFR. NO SIG WX.
THU NGT...MAINLY VFR EXCEPT POSSIBLE MVFR/IFR IN FOG/BR.
FRI-FRI NGT...VFR. NO SIG WX.
SAT...VFR/MVFR...CHC SHRA/TSRA.
SUN...VFR...NO SIG WX.
&&
.FIRE WEATHER...
RELATIVE HUMIDITIES ARE EXPECTED TO LOWER TO BETWEEN 40 TO 55
PERCENT TODAY...AND RISE TO BETWEEN 90 TO 100 PERCENT TONIGHT.
WINDS WILL BECOME WEST TO NORTHWEST TODAY AT 10 TO 15 MPH WITH GUSTS
UP TO 25 MPH POSSIBLE. EVEN HIGHER GUSTS MAY OCCUR IN THUNDERSTORMS
THIS AFTERNOON AND EVENING. THE WINDS WILL DIMINISH TO 5 TO 10 MPH
TONIGHT.
&&
.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED DURING THE NEXT 5 DAYS ON
THE MAIN STEM RIVERS...WITH MAINLY DRY WEATHER EXPECTED AND ABOVE
NORMAL TEMPERATURES. LAST NIGHTS RAINFALL HAD LITTLE IF ANY IMPACT
ON AREA RIVERS AND STREAMS.
THE BEST CHANCE FOR RAINFALL WILL BE THIS AFTERNOON AND
EVENING...AND AGAIN SATURDAY AND SATURDAY NIGHT. IN BOTH CASES THE
RAINFALL WILL IN THE FORM OF SCATTERED SHOWERS AND THUNDERSTORMS.
ALTHOUGH LOCALLY HEAVY RAIN IS POSSIBLE WHERE THUNDERSTORMS
OCCUR...OVERALL THERE SHOULD BE LITTLE OR NO IMPACT ON AREA RIVERS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...GJM/WASULA
NEAR TERM...GJM/WASULA
SHORT TERM...GJM
LONG TERM...JPV
AVIATION...JPV
FIRE WEATHER...GJM
HYDROLOGY...GJM
AREA FORECAST DISCUSSION...CORRECTED
NWS NEW YORK NY
738 AM EDT WED JUL 4 2012
.SYNOPSIS...
A WARM FRONT WILL MOVE ACROSS THE REGION THIS MORNING LEAVING THE
AREA IN A WARM SECTOR THIS AFTERNOON. A COLD FRONT WILL BE SLOWLY
APPROACHING AND THIS WILL MOVE THROUGH TONIGHT WITH ITS PARENT LOW
PRESSURE MOVING INTO THE GULF OF MAINE. WEAK HIGH PRESSURE THEN
BUILDS IN THROUGH FRIDAY NIGHT. A COLD FRONT WILL APPROACH ON
SATURDAY AND MOVE THROUGH SATURDAY NIGHT...FOLLOWED BY HIGH
PRESSURE INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FOR THE FIRST MORNING UPDATE...SLIGHT ADJUSTMENTS TO MATCH CURRENT
TRENDS IN DOPPLER RADAR REFLECTIVITY AND IR SATELLITE. LOOKS LIKE
MOST SHOWERS WITH SOME THUNDERSTORMS LOCATED OFFSHORE SHOULD BE
EXITING OUT OF THE FORECAST REGION BEFORE 15Z WITH SOME PARTIAL
CLEARING OF SKIES THEREAFTER INTO THE EARLY AFTERNOON. TEMPS AND
DEWPOINTS MOSTLY ON TRACK.
FOR TODAY...A WARM FRONT WILL CONTINUE TO PUSH NORTH AND
EAST...LEAVING THE REGION IN A WARM SECTOR FOR THE AFTERNOON.
HIGHER DEWPOINTS AND TEMPERATURES CAN BE EXPECTED. ONE SHORTWAVE
ALOFT AT 500MB WILL BE EXITING EARLY FOLLOWED BY SOME NEGATIVE
VORTICITY ADVECTION AT THIS LEVEL. THIS COULD DELAY THE ONSET OF
DIURNALLY DRIVEN CONVECTION ESPECIALLY WITH SOME SUBTLE HEIGHT
RISES. HOWEVER...STRONGER SHORTWAVE ALOFT FROM SOUTHEAST CANADA
WILL BE APPROACHING BY LATER IN THE AFTERNOON TOWARDS THE EVENING
AND THIS IS ALSO ASSOCIATED WITH A 250MB JET STREAK WHICH WILL BE
APPROACHING. 04Z RUN OF HRRR INDICATING CONVECTIVE INITIATION BY
19Z ACROSS NORTHERN INTERIOR AREAS. THIS INITIATION WILL BE
DEPENDENT ON THE SETUP OF THE DAYTIME TROUGH WITHIN THE REGION
WITH THE DAYTIME HEATING AND CONVERGENCE BOUNDARIES FROM SEA
BREEZES AND OUTFLOW.
WINDS WILL INCREASE ALOFT AT 250MB TO ABOUT 40-50 KT BY THE END OF
THE AFTERNOON AND THIS IN COMBINATION WITH ABOUT 1500 TO 2000 J/KG
OF SFC BASED CAPE SHOULD INCREASE THUNDERSTORM COVERAGE. WITH THE
INCREASE IN SHEAR TO 30 TO 40 KT...HIGHEST TOWARDS SOUTHERN CT AS
WELL AS INCREASED DIVERGENCE ALOFT...SOME THUNDERSTORMS COULD
BECOME RATHER STRONG OR EVEN SEVERE. WET BULB ZERO HEIGHTS WILL BE
AROUND 11 KFT...SO SMALL HAIL WILL ALSO BE POSSIBLE. SPC HAS THE
AREA IN A 5 PERCENT RISK FOR SEVERE WEATHER.
CONCERNING HEAT...HAVE A HIGH CONFIDENCE THAT DAY WILL BE MOSTLY DRY
GOING INTO THE AFTERNOON ALLOWING FOR A SIGNIFICANT PORTION OF
DIURNAL WARMING AND LEADING TO THE BUILDING INSTABILITY IN THE
ATMOSPHERE. VERY WARM 850 MB TEMPS BETWEEN 15 AND 18 DEGREES C WILL
BE IN PLACE WITH VERTICAL MIXING TO AT LEAST THAT LEVEL...PROBABLY
MORE TOWARDS 800 MB TOWARDS WESTERN LOCATIONS AND A SOUTHWESTERLY
WIND SHOULD HELP BOOST THESE TEMPERATURES RELATIVELY QUICKLY LATE
MORNING INTO THE AFTERNOON. NEAR NEW YORK CITY HEAT INDICES WILL BE
IN THE MID AND UPPER 90S WITH NEWARK NEAR 100 AS WELL AS SOME
LOCATIONS IN NORTHEAST NEW JERSEY. HEAT ADVISORY IN EFFECT FOR THESE
AREAS AS A RESULT.
THERE IS A MODERATE RISK OF RIP CURRENTS AT ATLANTIC OCEAN BEACHES
TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
TONIGHT...LOOKING FOR CONVECTION TO DIMINISH LATER IN THE EVENING
WITH LOSS OF DIURNAL HEATING AND THEREFORE CAPE FROM NORTH TO SOUTH.
DRIER AND COOLER AIR WILL BE MOVING IN ON A LIGHT NORTHERLY FLOW.
MAV/MET BLEND USED FOR LOWS.
THURSDAY...850MB TEMPS WILL BE SLIGHTLY COOLER BY 1-2 DEGREES AND
DEWPOINTS WILL BE SEVERAL DEGREES LOWER THAN THE PREVIOUS DAY.
HOWEVER...INCREASED NORTHERLY FLOW WILL ENHANCE THERMODYNAMIC
WARMING DUE TO DOWNSLOPE AND HIGHS ARE FORECAST TO BE AROUND 90 FOR
MANY LOCATIONS AND IN THE LOW TO MID 90S NEAR NEW YORK CITY. EVEN
WITH LOWER DEWPOINTS...HEAT INDEX SHOULD ONCE AGAIN OCCASIONALLY GET
TO AT LEAST 95 DEGREES. THEREFORE HEAT ADVISORY FOR THE CITY AGAIN
ON THURSDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
RIDGING BUILDS IN AT THE SFC AND ALOFT AS CUTOFF LOW OVER
CENTRAL CANADA TRACKS EASTWARD THROUGH THE END OF THE WEEK. STRONG
RIDGE REMAINS ENTRENCHED OVER THE MIDWEST AND PLAINS RESULTING IN A
FLATTENING UPPER FLOW ACROSS THE NORTHERN CONUS. THE VORTEX REMAINS
NEARLY STATIONARY OVER EASTERN CANADA WITH ANOTHER SPINNING OVER THE
GULF OF ALASKA RESULTING IN AN AMPLIFYING PATTERN DEVELOPING OVER
NOAM THIS WEEKEND INTO EARLY NEXT WEEK.
WEAK FRONTAL BOUNDARY REMAINS S OF THE AREA THROUGH THE END OF THE
WEEK WITH DRY AND HOT CONDS CONTINUING. NAM H85 TEMPS ARE ON THE LOW
END OF THE GUIDANCE FRI SO HAVE STAYED CLOSER TO GFS/EC WHICH RANGE
BETWEEN 16-19C. LOWER DEWPOINTS ON FRI SHOULD KEEP MAX HEAT INDEX
VALUES JUST BELOW 95.
THE GFS HAS BEEN TOO COOL WITH WITH ITS MAX T FORECASTS DURING THE
EXTREME HEAT EVENTS THIS SEASON...SO HAVE LEANED MORE TOWARDS THE
EC ON SAT WHICH IS INDICATING H85 TEMPS AROUND 21-22C. COLD FRONT
APPROACHES FROM THE N ON SAT...WITH A PRE-FRONTAL TROUGH EXPECTED
TO PRECEDE IT. LATEST SOUNDINGS ARE INDICATING A WARM NOSE AROUND
H8 WHICH WOULD PUT A LID ON ANY CONVECTION. THIS IS THE FIRST RUN
INDICATING THIS...SO HAVE MAINTAINED LOW CHC POPS FOR SAT AFTN
ALTHOUGH THIS MAY BE LOWERED IN SUBSEQUENT FORECASTS IF THIS
FEATURE PERSISTS. INCREASING CLOUD COVER MAY ULTIMATELY PLAY A
ROLE AND KEEP HIGHS FROM REACHING CURRENT FORECAST HIGHS
SAT...ESPECIALLY ACROSS NORTHERN ZONES. MOISTURE POOLING EXPECTED
WITH DEWPOINTS POSSIBLY REACHING THE LOWER 70S SAT AFTN. HEAT
ADVSYS MAY BE NEEDED FOR PORTIONS OF THE AREA.
EXPECT TEMPS TO GRADUALLY RETURN TO SEASONAL AVGS EARLY NEXT WEEK
AS LONGWAVE TROUGHING BECOMES ESTABLISHED OVER THE EASTERN THIRD
OF THE NATION...AND AS WEAK SYNOPTIC SCALE HIGH PRESSURE NOSES
EASTWARD INTO THE AREA. WITH SFC TROUGHING DEVELOPING EACH
AFTERNOON AND WEAK MID LEVEL VORT MAXES MOVING ACROSS IN NW FLOW
ALOFT...STILL EXPECT DIURNAL SCT-BKN CU DEVELOPMENT AND PERHAPS
SOME ISOLD SHOWERS/TSTMS.
&&
.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
A WARM FRONT WILL PUSH ACROSS THE AREA THIS MORNING...AND THEN A
WEAK COLD FRONT APPROACHES WEDNESDAY AFTERNOON. GENERALLY VFR FOR THE
PERIOD.
AN UPPER LEVEL SHORTWAVE WILL MOVE EAST THIS MORNING. A FEW LEFT
OVER SHOWERS PUSHES SOUTH AND EAST OF THE TERMINALS BETWEEN 12Z
AND 14Z. CIGS REMAIN BKN-OVC AROUND 100KFT THROUGH 14Z...THEN WE
SHOULD START TO CLEAR OUT. ANY CONVECTION ASSOCIATED WITH THIS
MORNINGS SHORTWAVE WILL REMAIN OUTSIDE OF THE TERMINALS.
A WEAK TROUGH IS EXPECTED TO DEVELOP IN THE VICINITY OF THE CITY
TERMINALS...WITH LATE AFTERNOON SEABREEZE DEVELOPMENT POSSIBLE AT
THE COASTAL LOCATIONS...MAINLY ISP/BDR/GON...AND JFK. FOR THE
REMAINDER OF THE TERMINALS...WINDS WILL BE FROM THE WEST AND GUSTY
THIS AFTERNOON.
A WEAK COLD FRONT WILL APPROACH THE REGION THIS AFTERNOON AND
EVENING AND THE TROUGH COULD ACT AS A FOCUS FOR SCATTERED STRONG
CONVECTION THIS AFTERNOON. CONFIDENCE OF TIMING AND COVERAGE
REMAINS TO LOW TO INCLUDE IN THE TAFS AT THIS TIME. THE THREAT OF
CONVECTION WILL BE CLOSELY MONITORED TODAY AND TAF AMENDMENTS WILL
BE ISSUED AS NECESSARY.
TONIGHT...WINDS AT ALL THE TERMINALS WILL BE FROM THE WEST-
NORTHWEST AT 10 KT OR LESS.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR SHIFTING WINDS
TODAY. LATE DAY SEABREEZE DEVELOPMENT EXPECTED AROUND 21-22Z.
AFTERNOON GUSTS MAY BE OCCASIONAL.
KLGA FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR SHIFTING WINDS
TODAY. AFTERNOON GUSTS MAY BE OCCASIONAL.
KEWR FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR SHIFTING WINDS
TODAY. AFTERNOON GUSTS MAY BE OCCASIONAL.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: AFTERNOON GUSTS MAY BE OCCASIONAL.
KHPN FCSTER COMMENTS: AFTERNOON GUSTS MAY BE OCCASIONAL.
KISP FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR SHIFTING WINDS
TODAY. LATE DAY SEABREEZE EXPECTED AROUND 20Z
OUTLOOK FOR 12Z THURSDAY THROUGH SATURDAY...
.THU-FRI NIGHT...VFR.
.SAT...SLIGHT CHANCE OF TSTMS WITH MVFR OR LOWER CONDS...MAINLY
LATE IN THE DAY.
&&
.MARINE...
SUB SCA CONDITIONS EXPECTED THROUGH THE PERIOD WITH WEAK PRESSURE
GRADIENTS IN PLACE.
&&
.HYDROLOGY...
ANY THUNDERSTORM THROUGH THIS EVENING WOULD BE ABLE TO PRODUCE
LOCALLY HEAVY RAINFALL WITH ANY SORT OF TRAINING OF CELLS LEADING TO
A MINOR FLOODING THREAT.
&&
.TIDES/COASTAL FLOODING...
THE TIDE LEVELS HAVE BEEN HIGHER AT NIGHT AND FOR TONIGHT...THE
ASTRONOMICAL TIDE LEVELS WILL BE SLIGHTLY LOWER THAN THOSE OF
TUESDAY TONIGHT. DATA WILL BE MONITORED TO SEE IF SITES WILL GET
CLOSE TO MINOR COASTAL FLOODING BENCHMARKS BUT IT LOOKS LIKE ALL
THE SITES WILL FALL AT LEAST A TENTH BELOW.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
NYZ072>075-176-178.
HEAT ADVISORY FROM NOON TO 8 PM EDT THURSDAY FOR NYZ072>075-
176-178.
NJ...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
NJZ004-006-103>108.
MARINE...NONE.
&&
$$
SYNOPSIS...24/JM
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...24
AVIATION...BC
MARINE...24/JM
HYDROLOGY...24/JM
TIDES/COASTAL FLOODING...JM
AREA FORECAST DISCUSSION
NWS NEW YORK NY
737 AM EDT WED JUL 4 2012
.SYNOPSIS...
A WARM FRONT WILL MOVE ACROSS THE REGION THIS MORNING LEAVING THE
AREA IN A WARM SECTOR THIS AFTERNOON. A COLD FRONT WILL BE SLOWLY
APPROACHING AND THIS WILL MOVE THROUGH TONIGHT WITH ITS PARENT LOW
PRESSURE MOVING INTO THE GULF OF MAINE. WEAK HIGH PRESSURE THEN
BUILDS IN THROUGH FRIDAY NIGHT. A COLD FRONT WILL APPROACH ON
SATURDAY AND MOVE THROUGH SATURDAY NIGHT...FOLLOWED BY HIGH
PRESSURE INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FOR THE FIRST MORNING UPDATE...SLIGHT ADJUSTMENTS TO MATCH CURRENT
TRENDS IN DOPPLER RADAR REFLECTIVITY AND IR SATELLITE. LOOKS LIKE
MOST SHOWERS WITH SOME THUNDERSTORMS LOCATED OFFSHORE SHOULD BE
EXITING OUT OF THE FORECAST REGION BEFORE 15Z WITH SOME PARTIAL
CLEARING OF SKIES THEREAFTER INTO THE EARLY AFTERNOON. TEMPS AND
DEWPOINTS MOSTLY ON TRACK.
FOR TODAY...A WARM FRONT WILL CONTINUE TO PUSH NORTH AND
EAST...LEAVING THE REGION IN A WARM SECTOR FOR THE AFTERNOON.
HIGHER DEWPOINTS AND TEMPERATURES CAN BE EXPECTED. ONE SHORTWAVE
ALOFT AT 500MB WILL BE EXITING EARLY FOLLOWED BY SOME NEGATIVE
VORTICITY ADVECTION AT THIS LEVEL. THIS COULD DELAY THE ONSET OF
DIURNALLY DRIVEN CONVECTION ESPECIALLY WITH SOME SUBTLE HEIGHT
RISES. HOWEVER...STRONGER SHORTWAVE ALOFT FROM SOUTHEAST CANADA
WILL BE APPROACHING BY LATER IN THE AFTERNOON TOWARDS THE EVENING
AND THIS IS ALSO ASSOCIATED WITH A 250MB JET STREAK WHICH WILL BE
APPROACHING. 04Z RUN OF HRRR INDICATING CONVECTIVE INITIATION BY
19Z ACROSS NORTHERN INTERIOR AREAS. THIS INITIATION WILL BE
DEPENDENT ON THE SETUP OF THE DAYTIME TROUGH WITHIN THE REGION
WITH THE DAYTIME HEATING AND CONVERGENCE BOUNDARIES FROM SEA
BREEZES AND OUTFLOW.
WINDS WILL INCREASE ALOFT AT 250MB TO ABOUT 40-50 KT BY THE END OF
THE AFTERNOON AND THIS IN COMBINATION WITH ABOUT 1500 TO 2000 J/KG
OF SFC BASED CAPE SHOULD INCREASE THUNDERSTORM COVERAGE. WITH THE
INCREASE IN SHEAR TO 30 TO 40 KT...HIGHEST TOWARDS SOUTHERN CT AS
WELL AS INCREASED DIVERGENCE ALOFT...SOME THUNDERSTORMS COULD
BECOME RATHER STRONG OR EVEN SEVERE. WET BULB ZERO HEIGHTS WILL BE
AROUND 11 KFT...SO SMALL HAIL WILL ALSO BE POSSIBLE. SPC HAS THE
AREA IN A 5 PERCENT RISK FOR SEVERE WEATHER.
CONCERNING HEAT...HAVE A HIGH CONFIDENCE THAT DAY WILL BE MOSTLY DRY
GOING INTO THE AFTERNOON ALLOWING FOR A SIGNIFICANT PORTION OF
DIURNAL WARMING AND LEADING TO THE BUILDING INSTABILITY IN THE
ATMOSPHERE. VERY WARM 850 MB TEMPS BETWEEN 15 AND 18 DEGREES C WILL
BE IN PLACE WITH VERTICAL MIXING TO AT LEAST THAT LEVEL...PROBABLY
MORE TOWARDS 800 MB TOWARDS WESTERN LOCATIONS AND A SOUTHWESTERLY
WIND SHOULD HELP BOOST THESE TEMPERATURES RELATIVELY QUICKLY LATE
MORNING INTO THE AFTERNOON. NEAR NEW YORK CITY HEAT INDICES WILL BE
IN THE MID AND UPPER 90S WITH NEWARK NEAR 100 AS WELL AS SOME
LOCATIONS IN NORTHEAST NEW JERSEY. HEAT ADVISORY IN EFFECT FOR THESE
AREAS AS A RESULT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
TONIGHT...LOOKING FOR CONVECTION TO DIMINISH LATER IN THE EVENING
WITH LOSS OF DIURNAL HEATING AND THEREFORE CAPE FROM NORTH TO SOUTH.
DRIER AND COOLER AIR WILL BE MOVING IN ON A LIGHT NORTHERLY FLOW.
MAV/MET BLEND USED FOR LOWS.
THURSDAY...850MB TEMPS WILL BE SLIGHTLY COOLER BY 1-2 DEGREES AND
DEWPOINTS WILL BE SEVERAL DEGREES LOWER THAN THE PREVIOUS DAY.
HOWEVER...INCREASED NORTHERLY FLOW WILL ENHANCE THERMODYNAMIC
WARMING DUE TO DOWNSLOPE AND HIGHS ARE FORECAST TO BE AROUND 90 FOR
MANY LOCATIONS AND IN THE LOW TO MID 90S NEAR NEW YORK CITY. EVEN
WITH LOWER DEWPOINTS...HEAT INDEX SHOULD ONCE AGAIN OCCASIONALLY GET
TO AT LEAST 95 DEGREES. THEREFORE HEAT ADVISORY FOR THE CITY AGAIN
ON THURSDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
RIDGING BUILDS IN AT THE SFC AND ALOFT AS CUTOFF LOW OVER
CENTRAL CANADA TRACKS EASTWARD THROUGH THE END OF THE WEEK. STRONG
RIDGE REMAINS ENTRENCHED OVER THE MIDWEST AND PLAINS RESULTING IN A
FLATTENING UPPER FLOW ACROSS THE NORTHERN CONUS. THE VORTEX REMAINS
NEARLY STATIONARY OVER EASTERN CANADA WITH ANOTHER SPINNING OVER THE
GULF OF ALASKA RESULTING IN AN AMPLIFYING PATTERN DEVELOPING OVER
NOAM THIS WEEKEND INTO EARLY NEXT WEEK.
WEAK FRONTAL BOUNDARY REMAINS S OF THE AREA THROUGH THE END OF THE
WEEK WITH DRY AND HOT CONDS CONTINUING. NAM H85 TEMPS ARE ON THE LOW
END OF THE GUIDANCE FRI SO HAVE STAYED CLOSER TO GFS/EC WHICH RANGE
BETWEEN 16-19C. LOWER DEWPOINTS ON FRI SHOULD KEEP MAX HEAT INDEX
VALUES JUST BELOW 95.
THE GFS HAS BEEN TOO COOL WITH WITH ITS MAX T FORECASTS DURING THE
EXTREME HEAT EVENTS THIS SEASON...SO HAVE LEANED MORE TOWARDS THE
EC ON SAT WHICH IS INDICATING H85 TEMPS AROUND 21-22C. COLD FRONT
APPROACHES FROM THE N ON SAT...WITH A PRE-FRONTAL TROUGH EXPECTED
TO PRECEDE IT. LATEST SOUNDINGS ARE INDICATING A WARM NOSE AROUND
H8 WHICH WOULD PUT A LID ON ANY CONVECTION. THIS IS THE FIRST RUN
INDICATING THIS...SO HAVE MAINTAINED LOW CHC POPS FOR SAT AFTN
ALTHOUGH THIS MAY BE LOWERED IN SUBSEQUENT FORECASTS IF THIS
FEATURE PERSISTS. INCREASING CLOUD COVER MAY ULTIMATELY PLAY A
ROLE AND KEEP HIGHS FROM REACHING CURRENT FORECAST HIGHS
SAT...ESPECIALLY ACROSS NORTHERN ZONES. MOISTURE POOLING EXPECTED
WITH DEWPOINTS POSSIBLY REACHING THE LOWER 70S SAT AFTN. HEAT
ADVSYS MAY BE NEEDED FOR PORTIONS OF THE AREA.
EXPECT TEMPS TO GRADUALLY RETURN TO SEASONAL AVGS EARLY NEXT WEEK
AS LONGWAVE TROUGHING BECOMES ESTABLISHED OVER THE EASTERN THIRD
OF THE NATION...AND AS WEAK SYNOPTIC SCALE HIGH PRESSURE NOSES
EASTWARD INTO THE AREA. WITH SFC TROUGHING DEVELOPING EACH
AFTERNOON AND WEAK MID LEVEL VORT MAXES MOVING ACROSS IN NW FLOW
ALOFT...STILL EXPECT DIURNAL SCT-BKN CU DEVELOPMENT AND PERHAPS
SOME ISOLD SHOWERS/TSTMS.
&&
.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
A WARM FRONT WILL PUSH ACROSS THE AREA THIS MORNING...AND THEN A
WEAK COLD FRONT APPROACHES WEDNESDAY AFTERNOON. GENERALLY VFR FOR THE
PERIOD.
AN UPPER LEVEL SHORTWAVE WILL MOVE EAST THIS MORNING. A FEW LEFT
OVER SHOWERS PUSHES SOUTH AND EAST OF THE TERMINALS BETWEEN 12Z
AND 14Z. CIGS REMAIN BKN-OVC AROUND 100KFT THROUGH 14Z...THEN WE
SHOULD START TO CLEAR OUT. ANY CONVECTION ASSOCIATED WITH THIS
MORNINGS SHORTWAVE WILL REMAIN OUTSIDE OF THE TERMINALS.
A WEAK TROUGH IS EXPECTED TO DEVELOP IN THE VICINITY OF THE CITY
TERMINALS...WITH LATE AFTERNOON SEABREEZE DEVELOPMENT POSSIBLE AT
THE COASTAL LOCATIONS...MAINLY ISP/BDR/GON...AND JFK. FOR THE
REMAINDER OF THE TERMINALS...WINDS WILL BE FROM THE WEST AND GUSTY
THIS AFTERNOON.
A WEAK COLD FRONT WILL APPROACH THE REGION THIS AFTERNOON AND
EVENING AND THE TROUGH COULD ACT AS A FOCUS FOR SCATTERED STRONG
CONVECTION THIS AFTERNOON. CONFIDENCE OF TIMING AND COVERAGE
REMAINS TO LOW TO INCLUDE IN THE TAFS AT THIS TIME. THE THREAT OF
CONVECTION WILL BE CLOSELY MONITORED TODAY AND TAF AMENDMENTS WILL
BE ISSUED AS NECESSARY.
TONIGHT...WINDS AT ALL THE TERMINALS WILL BE FROM THE WEST-
NORTHWEST AT 10 KT OR LESS.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR SHIFTING WINDS
TODAY. LATE DAY SEABREEZE DEVELOPMENT EXPECTED AROUND 21-22Z.
AFTERNOON GUSTS MAY BE OCCASIONAL.
KLGA FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR SHIFTING WINDS
TODAY. AFTERNOON GUSTS MAY BE OCCASIONAL.
KEWR FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR SHIFTING WINDS
TODAY. AFTERNOON GUSTS MAY BE OCCASIONAL.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: AFTERNOON GUSTS MAY BE OCCASIONAL.
KHPN FCSTER COMMENTS: AFTERNOON GUSTS MAY BE OCCASIONAL.
KISP FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR SHIFTING WINDS
TODAY. LATE DAY SEABREEZE EXPECTED AROUND 20Z
OUTLOOK FOR 12Z THURSDAY THROUGH SATURDAY...
.THU-FRI NIGHT...VFR.
.SAT...SLIGHT CHANCE OF TSTMS WITH MVFR OR LOWER CONDS...MAINLY
LATE IN THE DAY.
&&
.MARINE...
SUB SCA CONDITIONS EXPECTED THROUGH THE PERIOD WITH WEAK PRESSURE
GRADIENTS IN PLACE.
&&
.HYDROLOGY...
ANY THUNDERSTORM THROUGH THIS EVENING WOULD BE ABLE TO PRODUCE
LOCALLY HEAVY RAINFALL WITH ANY SORT OF TRAINING OF CELLS LEADING TO
A MINOR FLOODING THREAT.
&&
.TIDES/COASTAL FLOODING...
THE TIDE LEVELS HAVE BEEN HIGHER AT NIGHT AND FOR TONIGHT...THE
ASTRONOMICAL TIDE LEVELS WILL BE SLIGHTLY LOWER THAN THOSE OF
TUESDAY TONIGHT. DATA WILL BE MONITORED TO SEE IF SITES WILL GET
CLOSE TO MINOR COASTAL FLOODING BENCHMARKS BUT IT LOOKS LIKE ALL
THE SITES WILL FALL AT LEAST A TENTH BELOW.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
NYZ072>075-176-178.
HEAT ADVISORY FROM NOON TO 8 PM EDT THURSDAY FOR NYZ072>075-
176-178.
NJ...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
NJZ004-006-103>108.
MARINE...NONE.
&&
$$
SYNOPSIS...24/JM
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...24
AVIATION...BC
MARINE...24/JM
HYDROLOGY...24/JM
TIDES/COASTAL FLOODING...JM
AREA FORECAST DISCUSSION
NWS TAUNTON MA
707 AM EDT WED JUL 4 2012
.SYNOPSIS...
A WARM FRONT WILL TRIGGER SHOWERS AND EMBEDDED THUNDERSTORMS ACROSS
NEW ENGLAND THIS MORNING. BY MID TO LATE MORNING THE FRONT MOVES
OFFSHORE WITH SUNSHINE RETURNING THIS AFTERNOON ALONG WITH HOT AND
HUMID WEATHER. AN APPROACHING COLD FRONT MAY TRIGGER A FEW
SHOWERS/THUNDERSTORMS LATER TODAY AND TONIGHT. BEHIND THE FRONT IT
WILL TURN MUCH LESS HUMID AND NOT AS WARM THU AND FRI. HEAT AND
HUMIDITY BRIEFLY RETURN SAT BEFORE ANOTHER COLD FRONT INCREASES THE
RISK OF SHOWERS/THUNDERSTORMS LATER IN THE DAY. THEN A PATTERN
CHANGE TOWARD LESS HUMID AND NOT AS WARM CONDITIONS ARRIVES SUN AND
CONTINUES INTO MUCH OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
7 AM UPDATE...
NOT MUCH CHANGE FROM PREVIOUS FORECAST AS WE CONTINUE TO EXPECT
THESE WARM FRONTAL SHOWERS TO EXIT THE REGION BY MID MORNING. ONCE
THE WARM FRONT AND ATTENDING SHORT WAVE TROUGH MOVE OFFSHORE
SUFFICIENT SUBSIDENCE ON THE BACKSIDE SHOULD PROVIDE AT LEAST
PARTIAL SUNSHINE THIS AFTERNOON. THIS WILL DESTABLIZE THE ATM BUT
MODEL SOUNDINGS AND XSXNS SUGGEST A MID LEVEL SUBSIDENCE
INVERSION/CAP WILL DEVELOP THIS AFTERNOON. THIS SUBSIDENCE ALSO
RESULTS IN THE MID AND UPPER LEVELS OF THE COLUMN DRYING
SUBSTANTIALY. THIS SHOULD LIMIT AREAL COVERAGE OF ANY
SHOWERS/TSTMS TO ISOLATED OR WIDELY SCATTERED. THE CONDITIONS
LISTED ABOVE SHOULD ALSO LIMIT THE SEVERITY OF ANY STORMS TO SUB-
SEVERE.
NEW 00Z ECMWF HAS VERY LITTLE IF ANY QPF AFTER 18Z ACROSS THE AREA
AND THE LATEST HRRR KEEPS THE AREAL COVERAGE OF ANY AFTN
CONVECTION TO ISOLATED-WDLY SCT. THUS NO CHANGE FROM PREVIOUS
FORECAST. EARLIER DISCUSSION BELOW.
FCST GUIDANCE IN GOOD AGREEMENT OF THE SHRTWV TROF AXIS AND
ATTENDANT BAND OF SHOWERS WITH EMBEDDED HEAVIER RAINS ALONG A SFC
WARM FRNT GRADUALLY MOVING OFFSHORE INTO THE MIDDAY HOURS
/LINGERING LONGER MORESO FOR THE E SHORELINE AS THE MAIN UPR LVL
LOW WITH THE TROF AXIS DIGS INTO THE GULF OF ME AND BEGINS TO
UNDERGO OCCLUSION...SOME UNCERTAINTY AS TO HOW QUICKLY IT CLEARS
OUT OF THE BOSTON AREA/.
THERE ARE STILL STRONG INDICATIONS THAT TO THE REAR OF THE SHRTWV
TROF AXIS...THE COMBINATION OF SUBSIDENCE AND DRYING OF THE ATMOS
COLUMN COMBINED WITH A MORE WLY /CONTINENTAL/ COMPONENT OF FLOW WILL
ALLOW FOR CLEARING CONDITIONS AROUND THE NOONTIME INTO EARLY AFTN
PD...AND WHILE THE STRONG JULY SUN WILL PROMOTE HOT AND HUMID
CONDITIONS TOWARDS DESTABILIZING THE ATMOS BOUNDARY LYR...AIR
DRAWN TO THE REAR OF THE SHRTWV TROF AXIS MAY PSBLY CAP THE LOCAL
ENVIRONMENT TOWARDS AFTN CONVECTION AS RISING HEIGHTS COLLOCATED
WITH WARMING WITHIN THE H5-6 LYR IS EVIDENT IN MUCH OF THE MDL
SOLNS.
WITH THE KNOWLEDGE OF GRADUAL CLEARING YIELDING INSTABILITY ON THE
ORDER OF 2000 J/KG /THE NATURE OF WHICH IS THIN AND ELONGATED THRU
THE ATMOS COLUMN...AND DEPENDS ON SFC DWPTS WHICH COULD DRY WITH
MIX-DOWN OF DRIER AIR INFILTRATING AT THE MID-LVLS YIELDING LESSER
CAPE AMNTS/ IN A CYCLONIC ENVIRONMENT INCLUDING 40 KTS 0-6 KM BULK
SHEAR NW TO SE THRU NEW ENGLAND AND A PSBL CAPPING INVERSION AROUND
H5 GIVES THE FEELING OF SCTD SHOWER AND THUNDERSTORM ACTIVITY FOR
THE AFTN PD. HAVE LOW CONFIDENCE ON SEVERE /LAPSE RATES ARE POOR AND
H5 TEMPS AVG AROUND -7C/...RATHER FEEL THE AFTN CONVECTION WILL BE
SIMPLY A NUISANCE TO AFTN INTO EVNG 4TH OF JULY PLANS. EXACT
TEMPORAL AND SPATIAL SPECIFICS ARE UNCERTAIN...EARLIER WRF MDL RUNS
PAINTED THE GREATEST THREAT OVER N/E MA...NOW THE THREAT COULD BE
ANYWHERE ACROSS NEW ENGLAND.
THERE IS STILL SOME FEELING THAT PERHAPS SHOULD INSTABILITY AND
SHEAR COMBINE EFFECTIVELY PROMOTING STRONG AND SUSTAINING
UPDRAFTS...THAT PERHAPS CORES COULD RISE EXCEPTIONALLY INTO THE UPR
ATMOS...HELD LONG ENOUGH TO THE POINT WHEN THE WEIGHT EXCEEDS THE
RISE RESULTING IN THE CORE TO FALL AND CONSEQUENTIALLY STRONG AND
GUSTY WINDS AT THE SFC /THUS THERE IS STILL A THREAT OF PSBL
ISOLATED DAMAGING WINDS/. AGAIN...LOW CONFIDENCE ON SEVERE THREAT.
A FINAL NOTE...LOOKING UPSTREAM LATE LAST NIGHT...TO THE REAR OF THE
MAIN SHRTWV TROF ACROSS ONTARIO CANADA PRIOR TO MOVING INTO THE NERN
CONUS EXHIBITED IMPROVING CONDITIONS TO THE REAR...BUT DESTABILIZING
OF THE LOCAL ATMOS AND DEVELOPMENT OF SCTD SHOWERS AND
THUNDERSTORMS ALONG AND AHEAD OF THE FOLLOW-UP SFC COLD FRNT.
NOTHING WAS SEVERE. FEEL SUCH OUTCOMES MAY BE SIMILAR TO WHAT WE SEE
OVER NEW ENGLAND TODAY.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH 6 PM THURSDAY/...
LOW PRES WILL STACK AS IT BECOMES OCCLUDED ACROSS NOVA SCOTIA.
CONSEQUENTIALLY...HIGH PRES WITH MID-UPR LVL DRY AIR BUILDS SEWD OUT
OF CANADA AND ACROSS NEW ENGLAND. ANTICIPATE SCTD SHOWERS AND
THUNDERSTORMS TO DISSIPATE INTO THE OVRNGT HRS UNDER WLY FLOW
/MAINLY ACROSS E NEW ENGLAND AND ADJACENT WATERS/...GRADUALLY
BECOMING MOSTLY CLEAR AS WINDS TURN NWLY WITH A REINFORCING DRY COLD
FRNT BY THURS MORN. CYCLONIC FLOW SHOULD PREVAIL DURING THE DAYTIME
HRS AS MOISTURE SWIRLS AROUND THE LARGER LOW PRES WITHIN THE LOW-MID
LVLS. SO EXPECT SCTD-BKN CUMULUS ACROSS THE RGN UNDER NWLY FLOW WITH
A WELL-MIXED BOUNDARY LYR UP TO H85 /TEMPS AROUND +15C WITH THE JULY
SUN YIELD MAX TEMPS FOR THE DAY AROUND THE MID 80S/. THUS A DRY DAY
ON TAP WITH A MIX-DOWN OF DRIER AIR AND FASTER MOMENTUM /SHOULD SEE
GUSTS AROUND 10 TO 15 MPH/.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
SYNOPTIC OVERVIEW AND SENSIBLE WEATHER IMPACTS...
CLOSED MID LEVEL LOW OVER NOVA SCOTIA PROVIDES SEASONABLY WARM
WEATHER ALONG WITH COMFORTABLE HUMIDITY THU NGT INTO FRI. THEN A
BRIEF RETURN TO HOT AND HUMID WEATHER SAT AS APPROACHING SHORT WAVE
TROUGH ADVECTS THE EXCESSIVE HEAT FROM THE CENTRAL AND SOUTHERN
STATES INTO THE NORTHEAST. HOWEVER THIS IS SHORT LIVED AS THE U/A
PTN SHIFTS TO +PNA WITH THE WARM RIDGE/HEIGHT ANOMALY OVER THE
PLAINS RETROGRADING INTO THE WESTERN STATES AND WESTERN CANADA
BEGINNING SUN AND CONTINUING INTO MUCH OF NEXT WEEK. THIS INDUCES A
HIGH AMPLITUDE DOWNSTREAM MEAN TROUGH OVER SOUTHEAST CANADA AND THE
NORTHEAST. THIS WILL SUPPORT TEMPS COOLING BACK TO SEASONABLY WARM
LEVELS ALONG WITH LOWER HUMIDITY. AS FOR PRECIP CHANCES...OTHER THAN
A LOW RISK OF CONVECTION SAT/SAT NGT ASSOCIATED WITH COLD
FROPA...MAINLY DRY CONDITIONS WILL PREVAIL THIS PERIOD.
MODEL PREFERENCES...
MODELS IN VERY GOOD AGREEMENT ON THE LARGE SCALE FLOW ACROSS NORTH
AMERICA ALONG WITH THIS PTN CHANGE TO +PNA. BOTH THE GFS AND ECMWF
SUGGEST THE FROPA MAY BE SLOW TO EXIT THE REGION SUN ESPECIALLY
ACROSS CT/RI AND SOUTHEAST. THUS 00Z GMOS SLIGHT CHC POPS SUN SEEMS
REASONABLE.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
OVERVIEW...
7 AM UPDATE...
MODERATE TO HIGH CONFIDENCE. BAND OF SHOWERS OVER SOUTHERN NEW
ENGLAND WILL MOVE OFFSHORE AROUND 13-15Z. NO TSRA THIS MORNING.
AFTN SHRA/TSRA POSSIBLE BUT SHOULD BE ISOLATED TO WIDELY SCATTERED
IN AREAL COVERAGE AND INTENSITY REMAIN SUB-SEVERE. LOW CONFIDENCE
ON VSBY IMPACTS /INCLUDING FOG WED NGT INTO THURS MORN/. BETTER
CONFIDENCE ON CIGS...WILL KEEP ALL SITES ABOVE MVFR.
KBOS TAF...MODERATE TO HIGH CONFIDENCE. SHRA SHOULD EXIT AND MOVE
OFFSHORE AROUND 13Z. MARGINAL MVFR/VFR CIGS THEREAFTER WITH ANY
AFTN SHOWERS/TSTMS ISOLATED TO WIDELY SCATTERED IN AREAL COVERAGE.
GIVEN LIMITED AREAL COVERAGE DID NOT INCLUDE IN TAF.
KBDL TAF...MODERATE TO HIGH CONFIDENCE. SHOWERS EAST OF THE
TERMINAL AND WILL CONTINUE TO MOVE AWAY FROM THE AREA. LOW RISK OF
AFTN SHOWERS/TSTMS BUT AREAL COVERAGE SHOULD BE ISOLATED TO WIDELY
SCATTERED.
OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY...
THURSDAY NIGHT AND FRIDAY...HIGH CONFIDENCE FOR VFR.
SATURDAY-SUNDAY...MODERATE TO HIGH CONFIDENCE FOR VFR. LOW RISK OF
ISOLATED-WDLY SCT SHOWERS/TSTMS WITH BRIEF LOCAL MVFR CIGS/VSBYS
LATE SAT AFTERNOON INTO SUN MORNING...THEN IMPROVING LATER SUN.
&&
.MARINE...
MODERATE CONFIDENCE. SHOWERS AND ISOLATED THUNDERSTORMS WILL
IMPACT THE WATERS UNDER S/SW FLOW FOR THE MORNING PD...BECOMING
WLY AND IMPROVING INTO THE AFTN HRS. THEREAFTER THERE WILL BE THE
POSSIBILITY OF SCTD SHOWERS AND THUNDERSTORMS ALONG THE NEAR-SHORE
WATERS INTO EVNG. AM NOT ANTICIPATING ANYTHING SEVERE. ENERGY WILL
DISSIPATE AFTER A SECONDARY COLD FRNT FOLLOWED-UP BY NW FLOW
SWEEPS ACROSS THE WATERS INTO THURSDAY MORNING.
WINDS AND SEAS TO REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA INTO
THURSDAY NIGHT.
OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY...
FAIRLY TRANQUIL BOATING WEATHER THIS PERIOD. LOW RISK OF ISOLATED
TO WIDELY SCATTERED TSTMS LATE SAT INTO SUN AM AS COLD FRONT MOVES
ACROSS THE AREA. OTHERWISE NOT MUCH SENSIBLE WEATHER. WINDS WILL
REMAIN FAIRLY LIGHT...YIELDING NOT MUCH WIND WAVE OR SWELL TO SPEAK
OF. FORECAST CONFIDENCE MODERATE TO HIGH.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...NOCERA/SIPPRELL
NEAR TERM...NOCERA/SIPPRELL - UPDATED 707 AM
SHORT TERM...SIPPRELL
LONG TERM...NOCERA
AVIATION...NOCERA/SIPPRELL - UPDATED 707 AM
MARINE...NOCERA/SIPPRELL
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1056 PM EDT THU JUL 5 2012
.UPDATE...
STORMS TRYING TO REFIRE ALONG OUTFLOW BOUNDARY AS IT MOVES SOUTH
INTO ATL METRO. HAVE TWEAKED WX AND POP GRIDS AGAIN TO ACCOUNT FOR
CURRENT TRENDS. SHOULD BE CLEAR FOR REST OF THE NIGHT NORTH OF THE
BOUNDARY. REST OF FCST LOOKS GOOD.
SNELSON
&&
.PREV DISCUSSION... /ISSUED 812 PM EDT THU JUL 5 2012/
UPDATE...
QUICK UPDATE TO FINE TUNE POP AND WX GRIDS BASED ON CURRENT TRENDS
.ESP MCS OVER ERN TN. LAST SEVERAL HRRR RUNS HAVE BEEN IN GOOD
AGREEMENT ON BRINGING MCS DOWN INTO NRN COUNTIES AROUND 00-01Z AND
INTO ATL METRO AROUND 02-03Z. SHOULD WEAKEN AS IT MOVES SOUTH BUT
EXPECT SIGNIFICANT THREAT FOR DAMAGING WINDS THIS EVENING IN NORTH
GA. WILL UPDATE HWO AS WELL.
SNELSON
PREV DISCUSSION... /ISSUED 158 PM EDT THU JUL 5 2012/
SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
GEORGIA REMAINS UNDER THE EASTERN END OF THE CENTRAL U.S. RIDGE
THROUGH THE PERIOD. ALTHOUGH THE RIDGE IS FORECAST BY THE GFS/NAM
AND ECMWF TO BUILD EASTWARD SOME FRIDAY AND WILL CONTINUE TO BE
STRONG ENOUGH FOR ABOVE NORMAL TEMPERATURES...IT SHOULD NOT BE
STRONG ENOUGH TO SUPPRESS SCATTERED...MAINLY DIURNAL...CONVECTION.
PERSISTENT SURFACE TROUGH IN THE LEE OF THE APPALACHIANS WILL
CONTINUE TO PROVIDE SOME LOW LEVEL SUPPORT FOR THUNDERSTORM
DEVELOPMENT. ANY WEAK MID LEVEL CIRCULATIONS FROM MORE WIDESPREAD
CONVECTION ALONG THE NORTHERN PERIPHERY OF THE RIDGE THAT MAKE IT
AROUND THE EASTERN POINT OF THE RIDGE...LIKE THE PAIR MOVING THROUGH
THE EASTERN OHIO VALLEY AND CENTRAL APPALACHIANS THIS AFTERNOON...
MAY HELP TO FOCUS CONVECTIVE ACTIVITY AS WELL ACROSS NORTH GEORGIA
EACH AFTERNOON. STRONG SURFACE HEATING AND AMPLE LOW LEVEL MOISTURE
ARE IN PLACE AGAIN THIS AFTERNOON AND WILL BE PRESENT FRIDAY
AFTERNOON FOR MODERATE INSTABILITY. HOWEVER...COMBINED WITH WEAK
SHEAR AND A LACK OF A STRONG FOCUSING MECHANISM THIS SHOULD KEEP
SEVERE THUNDERSTORM THREAT ISOLATED.
WITH AFTERNOON HIGH TEMPERATURES EXPECTED TO REMAIN IN THE MID TO
UPPER 90S...AFTERNOON HEAT INDEX VALUES WILL REMAIN UNCOMFORTABLY
HIGH...BUT COMBINED WITH OVERNIGHT LOWS IN THE UPPER 60S TO LOWER
70S IN MOST AREAS WE ARE NOT EXPECTED TO REACH HEAT ADVISORY
CRITERIA THROUGH THE PERIOD.
20
LONG TERM /SATURDAY THROUGH THURSDAY/...
NO CHANGES TO CURRENT LONG TERM PLANNED. PREVIOUS LONG TERM
DISCUSSION FOLLOWS...
/ISSUED 414 AM EDT THU JUL 5 2012/
THE MODELS ARE IN GOOD AGREEMENT IN THE EXTENDED PERIODS. THE UPPER
LEVEL RIDGING SHIFTS WEST OVER THE CENTRAL PLAINS ALLOWING WEAK
IMPULSES TO CONTINUE TO IMPACT PORTIONS OF THE SOUTHEAST...
PROVIDING FOCUS FOR MAINLY DIURNALLY DRIVEN CONVECTION. MODELS
AGREE MAIN FOCUS TO BE ACROSS NORTH GEORGIA ON SATURDAY AND SUNDAY
AHEAD OF A BROAD LONGWAVE TROUGH WHICH SETS UP OVER THE EASTERN
U.S. BY MONDAY AFTERNOON. AT THE SFC...WEAK SURFACE BOUNDARY
REMAINS IN CLOSE PROXIMITY TO THE FORECAST AREA...EVENTUALLY
SAGGING SOUTH BY SUNDAY NIGHT...SPREADING THE FOCUS FOR
CONVECTION SOUTHWARD THROUGH THE END OF THE EXTENDED PERIODS.
MODELS CONTINUE TO SHOW GOOD MOISTURE ACROSS THE AREA...
PRECIPITABLE WATER REMAINS NEAR 2 INCHES...AND PLENTY OF
INSTABILITY...SURFACE CAPES GREATER THAN 1500 EACH AFTERNOON WITH
DIURNALLY DRIVEN CONVECTION POSSIBLE ACROSS ALL OF NORTH
AND CENTRAL GEORGIA. GUIDANCE TEMPERATURES NEAR OR JUST ABOVE
NORMAL THROUGH THE EXTENDED PERIODS. BELIEVE MONDAY THROUGH
WEDNESDAY AFTERNOON TEMPERATURES ARE ON THE COOL SIDE AS MODELS
MAY BE OVERDOING CLOUD COVER ASSOCIATED WITH THE SURFACE BOUNDARY.
ANTICIPATE LESS CLOUDS UNTIL HEATING KICKS IN EACH DAY AND HAVE
GONE WARMER THAN GUIDANCE LATTER PORTIONS OF THE FORECAST.
ATWELL/17
AVIATION...
00Z UPDATE...
PRIMARY CONCERN IS TIMING AND LIKELIHOOD FOR TSRA. BROKEN LINE OF
STORMS WILL REMAIN SOUTH OF ATL AS IT MOVES SLOWLY SOUTH. COULD
BRING A PERIOD OF SE WINDS AT ATL FOR AN HOUR OR TWO FROM 00-01Z.
SCATTERED OVER NORTH STORMS SHOULD PUSH INTO ATL METRO AROUND 02Z.
COVERAGE A LITTLE LOWER THAN FIRST THOUGHT SO MAY HAVE TO PULL
TEMPO FROM FCST IF COVERAGE CONTINUES TO DROP. TSRA SHOULD
DECREASE AND DISSIPATE AFTER 06Z AT MOST AREAS. EXPECT VFR
CIGS/VSBYS OVERNIGHT AND FRIDAY MORNING EXCEPT PATCHY MVFR FOG AT
AIRPORTS THAT SEE RAIN TONIGHT.
//ATL CONFIDENCE...00Z UPDATE...
MEDIUM CONFIDENCE FOR TSRA LIKELIHOOD.
HIGH ON ALL OTHER ELEMENTS.
SNELSON
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 72 98 72 99 / 50 40 40 30
ATLANTA 75 97 75 96 / 50 40 40 30
BLAIRSVILLE 67 94 67 91 / 70 40 40 40
CARTERSVILLE 68 98 69 98 / 50 40 40 40
COLUMBUS 74 96 75 94 / 40 40 40 30
GAINESVILLE 73 97 73 98 / 50 40 40 40
MACON 74 96 74 96 / 50 40 40 30
ROME 69 98 69 98 / 50 40 40 40
PEACHTREE CITY 68 96 69 95 / 50 40 40 30
VIDALIA 76 96 75 96 / 50 40 40 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SNELSON
LONG TERM....39
AVIATION...SNELSON
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
812 PM EDT THU JUL 5 2012
.PREV DISCUSSION... /ISSUED 657 PM EDT THU JUL 5 2012/
UPDATE...
QUICK UPDATE TO FINE TUNE POP AND WX GRIDS BASED ON CURRENT TRENDS
..ESP MCS OVER ERN TN. LAST SEVERAL HRRR RUNS HAVE BEEN IN GOOD
AGREEMENT ON BRINGING MCS DOWN INTO NRN COUNTIES AROUND 00-01Z AND
INTO ATL METRO AROUND 02-03Z. SHOULD WEAKEN AS IT MOVES SOUTH BUT
EXPECT SIGNIFICANT THREAT FOR DAMAGING WINDS THIS EVENING IN NORTH
GA. WILL UPDATE HWO AS WELL.
SNELSON
PREV DISCUSSION... /ISSUED 158 PM EDT THU JUL 5 2012/
SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
GEORGIA REMAINS UNDER THE EASTERN END OF THE CENTRAL U.S. RIDGE
THROUGH THE PERIOD. ALTHOUGH THE RIDGE IS FORECAST BY THE GFS/NAM
AND ECMWF TO BUILD EASTWARD SOME FRIDAY AND WILL CONTINUE TO BE
STRONG ENOUGH FOR ABOVE NORMAL TEMPERATURES...IT SHOULD NOT BE
STRONG ENOUGH TO SUPPRESS SCATTERED...MAINLY DIURNAL...CONVECTION.
PERSISTENT SURFACE TROUGH IN THE LEE OF THE APPALACHIANS WILL
CONTINUE TO PROVIDE SOME LOW LEVEL SUPPORT FOR THUNDERSTORM
DEVELOPMENT. ANY WEAK MID LEVEL CIRCULATIONS FROM MORE WIDESPREAD
CONVECTION ALONG THE NORTHERN PERIPHERY OF THE RIDGE THAT MAKE IT
AROUND THE EASTERN POINT OF THE RIDGE...LIKE THE PAIR MOVING THROUGH
THE EASTERN OHIO VALLEY AND CENTRAL APPALACHIANS THIS AFTERNOON...
MAY HELP TO FOCUS CONVECTIVE ACTIVITY AS WELL ACROSS NORTH GEORGIA
EACH AFTERNOON. STRONG SURFACE HEATING AND AMPLE LOW LEVEL MOISTURE
ARE IN PLACE AGAIN THIS AFTERNOON AND WILL BE PRESENT FRIDAY
AFTERNOON FOR MODERATE INSTABILITY. HOWEVER...COMBINED WITH WEAK
SHEAR AND A LACK OF A STRONG FOCUSING MECHANISM THIS SHOULD KEEP
SEVERE THUNDERSTORM THREAT ISOLATED.
WITH AFTERNOON HIGH TEMPERATURES EXPECTED TO REMAIN IN THE MID TO
UPPER 90S...AFTERNOON HEAT INDEX VALUES WILL REMAIN UNCOMFORTABLY
HIGH...BUT COMBINED WITH OVERNIGHT LOWS IN THE UPPER 60S TO LOWER
70S IN MOST AREAS WE ARE NOT EXPECTED TO REACH HEAT ADVISORY
CRITERIA THROUGH THE PERIOD.
20
LONG TERM /SATURDAY THROUGH THURSDAY/...
NO CHANGES TO CURRENT LONG TERM PLANNED. PREVIOUS LONG TERM
DISCUSSION FOLLOWS...
/ISSUED 414 AM EDT THU JUL 5 2012/
THE MODELS ARE IN GOOD AGREEMENT IN THE EXTENDED PERIODS. THE UPPER
LEVEL RIDGING SHIFTS WEST OVER THE CENTRAL PLAINS ALLOWING WEAK
IMPULSES TO CONTINUE TO IMPACT PORTIONS OF THE SOUTHEAST...
PROVIDING FOCUS FOR MAINLY DIURNALLY DRIVEN CONVECTION. MODELS
AGREE MAIN FOCUS TO BE ACROSS NORTH GEORGIA ON SATURDAY AND SUNDAY
AHEAD OF A BROAD LONGWAVE TROUGH WHICH SETS UP OVER THE EASTERN
U.S. BY MONDAY AFTERNOON. AT THE SFC...WEAK SURFACE BOUNDARY
REMAINS IN CLOSE PROXIMITY TO THE FORECAST AREA...EVENTUALLY
SAGGING SOUTH BY SUNDAY NIGHT...SPREADING THE FOCUS FOR
CONVECTION SOUTHWARD THROUGH THE END OF THE EXTENDED PERIODS.
MODELS CONTINUE TO SHOW GOOD MOISTURE ACROSS THE AREA...
PRECIPITABLE WATER REMAINS NEAR 2 INCHES...AND PLENTY OF
INSTABILITY...SURFACE CAPES GREATER THAN 1500 EACH AFTERNOON WITH
DIURNALLY DRIVEN CONVECTION POSSIBLE ACROSS ALL OF NORTH
AND CENTRAL GEORGIA. GUIDANCE TEMPERATURES NEAR OR JUST ABOVE
NORMAL THROUGH THE EXTENDED PERIODS. BELIEVE MONDAY THROUGH
WEDNESDAY AFTERNOON TEMPERATURES ARE ON THE COOL SIDE AS MODELS
MAY BE OVERDOING CLOUD COVER ASSOCIATED WITH THE SURFACE BOUNDARY.
ANTICIPATE LESS CLOUDS UNTIL HEATING KICKS IN EACH DAY AND HAVE
GONE WARMER THAN GUIDANCE LATTER PORTIONS OF THE FORECAST.
ATWELL/17
&&
.AVIATION...
00Z UPDATE...
PRIMARY CONCERN IS TIMING AND LIKELIHOOD FOR TSRA. BROKEN LINE OF
STORMS WILL REMAIN SOUTH OF ATL AS IT MOVES SLOWLY SOUTH. COULD
BRING A PERIOD OF SE WINDS AT ATL FOR AN HOUR OR TWO FROM 00-01Z.
SCATTERED OVER NORTH STORMS SHOULD PUSH INTO ATL METRO AROUND 02Z.
COVERAGE A LITTLE LOWER THAN FIRST THOUGHT SO MAY HAVE TO PULL
TEMPO FROM FCST IF COVERAGE CONTINUES TO DROP. TSRA SHOULD
DECREASE AND DISSIPATE AFTER 06Z AT MOST AREAS. EXPECT VFR
CIGS/VSBYS OVERNIGHT AND FRIDAY MORNING EXCEPT PATCHY MVFR FOG AT
AIRPORTS THAT SEE RAIN TONIGHT.
//ATL CONFIDENCE...00Z UPDATE...
MEDIUM CONFIDENCE FOR TSRA LIKELIHOOD.
HIGH ON ALL OTHER ELEMENTS.
SNELSON
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 72 98 72 99 / 60 40 40 30
ATLANTA 75 97 75 96 / 50 40 40 30
BLAIRSVILLE 67 94 67 91 / 70 40 40 40
CARTERSVILLE 68 98 69 98 / 60 40 40 40
COLUMBUS 74 96 75 94 / 50 40 40 30
GAINESVILLE 73 97 73 98 / 60 40 40 40
MACON 74 96 74 96 / 50 40 40 30
ROME 69 98 69 98 / 60 40 40 40
PEACHTREE CITY 68 96 69 95 / 50 40 40 30
VIDALIA 76 96 75 96 / 50 40 40 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SNELSON
LONG TERM....39
AVIATION...SNELSON
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
502 PM CDT WED JUL 4 2012
.DISCUSSION...
445 PM CDT
FORECAST FOCUS SQUARELY ON CONTINUATION OF INTENSE HEAT THROUGH
FRIDAY. AN EXCESSIVE HEAT WARNING IS IN EFFECT FOR THE ENTIRE
FORECAST AREA THROUGH 10 PM CDT FRIDAY.
AIR TEMPERATURES CLIMBED TO 95 TO 102 ACROSS THE FA THIS
AFTERNOON WITH HEAT INDEX NUMBERS UP TO 103 TO 108. NORTHEASTWARD
EXTENSION OF THE 850KPA THERMAL RIDGE THAT STRETCHES ACROSS THE
MID MO VALLEY TO THE UPPER MIDWEST TODAY IS TO BE SUPPRESSED A
BIT TO THE S ACROSS SOUTHERN WI AND NORTHERN IL FOR THU AND FRI
AS THE UPPER RIDGE OVER THE UPPER MIDWEST AND WESTERN ONTARIO
GETS FLATTENED BY THE UPPER LOW TRACKING E OVER THE CANADIAN
PRAIRIE. EXPECT MAX TEMPS ON THU THAT ARE A DEG OR TWO ABOVE
TODAY/S...AND THEN FOR FRI AN ADDITIONAL DEG HIGHER OVER THU AT
MOST LOCATIONS.
WHILE A WEAK LAKE BREEZE IS EXPECTED TO DEVELOP TOMORROW
AFTERNOON IT IS NOT EXPECTED TO MOVE MORE THAN MARGINALLY INLAND
UNTIL LATE IN THE AFTERNOON AND EARLY EVENING SO ANY RELIEF WILL
BE VERY LIMITED AND SHORT LIVED AS LIGHT SW LOW LEVEL FLOW PUSHES
THE HOT AIR RIGHT BACK OUT OVER THE SHORE LINE BY LATER THU
EVENING.
TIMING OF COOL FRONT AND LAKE BREEZE DURING FRI COMPLICATES THINGS
A BIT BUT FEEL THAT THE ACTUAL FRONT WILL REACH NORTHERN IL UNTIL
VERY LATE FRI OR MORE LIKELY FRI NIGHT. WEAK W TO SW LOW LEVEL
FLOW DURING FRI WILL LIKELY ALLOW A LAKE BREEZE TO PUSH INLAND BUT
NOT ANTICIPATED UNTIL DURING THE LATER AFTERNOON-EARLY EVENING SO
FRI WILL BE ANOTHER VERY HOT DAY ACROSS THE VAST MAJORITY OF THE
FA WITH THE FAR NE CORNER OF IL LIKELY THE ONLY PART OF THE FA TO
GET ANY REAL RELIEF UNTIL THE ACTUAL COOL FRONT DROPS ACROSS THE
AREA.
WITH MAX TEMPERATURES GENERALLY IN THE 100 TO 105 RANGE THU AND
FRI THE LOWERING OF SURFACE DEW POINTS BACK UPPER 60S AND LOWER
70S PER GUIDANCE WILL KEEP HI NUMBERS UP IN THE 105-115 ACROSS
MUCH OF THE AREA THU AND FRI AFTERNOONS. WITH OVERNIGHT HEAT
INDEX NUMBERS ONLY FALLING TO AROUND 75 TONIGHT AND THU NIGHT
EXCESSIVE HEAT WARNING CRITERIA FOR ALL OTHER COUNTIES
SURROUNDING COOK WHICH HAS IT/S OWN SET FOR THE CITY WILL BE
REACHED SO ADVISORY EXPANDED ACROSS THE ENTIRE AREA.
HEAT AND HUMIDITY RESULT IN LARGE VALUES OF POTENTIAL INSTABILITY
BUT LOW LEVEL FOCUS AND MID-UPPER DISTURBANCES LACKING THUS ONLY
SLIGHT CHANCES OF ISOLATED TS IF ALL INGREDIENTS COME TOGETHER AT
THE RIGHT TIME AT A PARTICULAR SPOT. THUS...POP NUMBERS TOO LOW
FOR ANY MENTION OF EVEN SLIGHT CHANCE UNTIL FRI NIGHT WITH THE
COOL FRONT MOVING INTO NORTHERN IL. MODELS NOT BULLISH WITH
PUSHING THIS BOUNDARY FURTHER S SAT OR SUN SO WILL HAVE SLIGHT
CHANCE TO LOW END CHANCE POPS GOING ALL OR PARTS OF THE FA FOR
SAT THROUGH MON UNTIL BOUNDARY FINALLY GETS SHOVED ACROSS CENTRAL
TO SOUTHERN IL TAKING LOW LEVEL MOISTURE POOLED ON EITHER SIDE OF
IT OUT OF THE LOCAL FA.
TRS
&&
.CLIMATE...
520 AM CDT
RECORDS...
CHICAGO
WED JUL 4 MAX 102 1911 MIN 80 1921
THU JUL 5 MAX 102 1911 MIN 82 1911
FRI JUL 6 MAX 99 1988 MIN 80 2977
ROCKFORD
WED JUL 4 MAX 101 1911 MIN 77 1977
THU JUL 5 MAX 100 1911 MIN 77 1911
FRI JUL 6 MAX 102 1936 MIN 73 1948
THE ALL TIME RECORD HIGH FOR CHICAGO IS 105 ON JULY 24 1934...
AND FOR ROCKFORD IS 112 ON JULY 14 1936.
FOR CHICAGO THE MOST CONSECUTIVE 100 DEGREE OR HIGHER DAYS IS
THREE...JULY 3RD THROUGH 5TH OF 1911...AND ALSO AUGUST 4TH
THROUGH 6TH OF 1947.
FOR ROCKFORD THE MOST CONSECUTIVE 100 DEGREE OR HIGHER DAYS IS
NINE...JULY 6TH THROUGH 14TH OF 1936.
IZZI/TRS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* NONE. BMD
//DISCUSSION...UPDATED 18Z...
A LARGE RIDGE EXTENDS ACROSS THE REGION WITH LIGHT W TO SW WINDS
THIS AFTERNOON. MIXING HAS BEEN SLOW THUS FAR TODAY...BUT GUSTS
HAVE DEVELOPED AT ORD AND MDW. BASED ON OBS AND CU
DEVELOPMENT...KEPT WIND GUSTS CONFINED TO ORD AND MDW...BUT MAY
SEE A FEW SPORADIC GUSTS AT GYY. LATEST SATELLITE IMAGERY SHOWS CU
IS DEVELOPING OVER EXTREME NE IL AND NW IN. MORE INTENSE CU
DEVELOPMENT CAN BE FOUND EAST OF VPZ AND IN SOUTHERN IROQUOIS AND
FORD COUNTIES. EXPECTING FEW TO SCT CU TO DEVELOP PRIMARILY OVER
THE EASTERN TERMINALS. CU BASES MAY BE LOWER THAN INDICATED...IN
THE 050-070 RANGE...BUT VFR EITHER WAY.
EXPECTING A LAKE BREEZE TO DEVELOP IMMEDIATELY ALONG THE LAKESHORE
AROUND 00Z AND REMAIN MORE OR LESS RIGHT ALONG THE LAKE SHORE.
WHILE THE LAKE BREEZE WILL NOT AFFECT ORD/MDW WINDS...MAY SEE
ISOLATED CONVECTION FORM ALONG IT. THE LATEST RUC ANALYSIS
INDICATES VERY LITTLE CIN AND OVER 3000 J/KG OF CAPE ALONG THE
LAKESHORE. IN THIS VERY UNSTABLE ENVIRONMENT...ANY FORCING FEATURE
SUCH AS THE LAKE BREEZE COULD LEAD TO A THUNDERSTORM OR TWO.
STEERING FLOW FOR THE STORMS IS NORTHWEST...THEREFORE GOING WITH A
DRY FORECAST FOR ORD. HOWEVER...IF THE LAKE BREEZE PUSHES FARTHER
INLAND THAN EXPECTED...TS MAY FORM NEAR ORD/MDW.
WINDS AND CU DIMINISH AND WINDS BECOME SW TONIGHT. A SIMILAR
SITUATION IS EXPECTED TOMORROW WITH WEST WINDS...GUSTS DEVELOPING
IN THE LATE MORNING...AND SCT VFR CU DEVELOPMENT.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS. BMD
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
* THURSDAY NIGHT...VFR.
* FRIDAY...VFR. POSSIBLE LAKE BREEZE IN THE AFTERNOON.
* FRIDAY NIGHT THROUGH MONDAY...VFR. SLIGHT CHANCE OF TSRA.
* TUESDAY...VFR.
&&
.MARINE...
250 PM CDT
A WEAK COLD FRONT HAS BECOME NEARLY STATIONARY OVER CENTRAL LAKE
MICHIGAN THIS AFTERNOON...BUT WILL LIFT BACK NORTH TONIGHT AS LOW
PRESSURE OVER THE EASTERN DAKOTAS AND CANADIAN PRAIRIES LIFTS TOWARD
HUDSON BAY. THE LOW WILL CONTINUE EAST ACROSS HUDSON BAY THURSDAY
AND THURSDAY NIGHT...WITH A COLD FRONT TRAILING ACROSS THE WESTERN
LAKES REGION AND SLIDING SOUTH DOWN LAKE MICHIGAN AND SETTLING
ACROSS THE SOUTH END BY EARLY FRIDAY. THE FRONT WILL SLOW BRIEFLY
FRIDAY NIGHT AS A WEAK SURFACE WAVE RIPPLES EAST ALONG THE FRONT...
WITH NORTHERLY FLOW THEN STRENGTHENING SATURDAY AS HIGH PRESSURE
BUILDS ACROSS THE UPPER MIDWEST AND NORTHERN GREAT LAKES.
WINDS WILL GENERALLY BE ON THE LIGHT SIDE OUTSIDE OF ANY
THUNDERSTORM GUSTS UNTIL SATURDAY...WHEN THE TIGHTENING NORTHERLY
GRADIENT AND PUSH OF SOMEWHAT COOLER AIR RESULTS IN NORTH-NORTHEAST
WINDS INCREASING INTO THE 15-20 KT RANGE PERHAPS WITH A FEW GUSTS IN
THE 20-25 KT RANGE SATURDAY INTO SATURDAY NIGHT.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...EXCESSIVE HEAT WARNING...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-
ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-
ILZ022-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 10 PM FRIDAY.
IN...EXCESSIVE HEAT WARNING...INZ001-INZ002-INZ010-INZ011-INZ019
UNTIL 10 PM FRIDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
446 PM CDT WED JUL 4 2012
.DISCUSSION...
445 PM CDT
FORECAST FOCUS SQUARELY ON CONTINUATION OF INTENSE HEAT THROUGH
FRIDAY. AN EXCESSIVE HEAT WARNING IS IN EFFECT FOR THE ENTIRE
FORECAST AREA THROUGH 10 PM CDT FRIDAY.
AIR TEMPERATURES CLIMBED TO 95 TO 102 ACROSS THE FA THIS
AFTERNOON WITH HEAT INDEX NUMBERS UP TO 103 TO 108. NORTHEASTWARD
EXTENSION OF THE 850KPA THERMAL RIDGE THAT STRETCHES ACROSS THE
MID MO VALLEY TO THE UPPER MIDWEST TODAY IS TO BE SUPPRESSED A
BIT TO THE S ACROSS SOUTHERN WI AND NORTHERN IL FOR THU AND FRI
AS THE UPPER RIDGE OVER THE UPPER MIDWEST AND WESTERN ONTARIO
GETS FLATTENED BY THE UPPER LOW TRACKING E OVER THE CANADIAN
PRAIRIE. EXPECT MAX TEMPS ON THU THAT ARE A DEG OR TWO ABOVE
TODAY/S...AND THEN FOR FRI AN ADDITIONAL DEG HIGHER OVER THU AT
MOST LOCATIONS.
WHILE A WEAK LAKE BREEZE IS EXPECTED TO DEVELOP TOMORROW
AFTERNOON IT IS NOT EXPECTED TO MOVE MORE THAN MARGINALLY INLAND
UNTIL LATE IN THE AFTERNOON AND EARLY EVENING SO ANY RELIEF WILL
BE VERY LIMITED AND SHORT LIVED AS LIGHT SW LOW LEVEL FLOW PUSHES
THE HOT AIR RIGHT BACK OUT OVER THE SHORE LINE BY LATER THU
EVENING.
TIMING OF COOL FRONT AND LAKE BREEZE DURING FRI COMPLICATES THINGS
A BIT BUT FEEL THAT THE ACTUAL FRONT WILL REACH NORTHERN IL UNTIL
VERY LATE FRI OR MORE LIKELY FRI NIGHT. WEAK W TO SW LOW LEVEL
FLOW DURING FRI WILL LIKELY ALLOW A LAKE BREEZE TO PUSH INLAND BUT
NOT ANTICIPATED UNTIL DURING THE LATER AFTERNOON-EARLY EVENING SO
FRI WILL BE ANOTHER VERY HOT DAY ACROSS THE VAST MAJORITY OF THE
FA WITH THE FAR NE CORNER OF IL LIKELY THE ONLY PART OF THE FA TO
GET ANY REAL RELIEF UNTIL THE ACTUAL COOL FRONT DROPS ACROSS THE
AREA.
WITH MAX TEMPERATURES GENERALLY IN THE 100 TO 105 RANGE THU AND
FRI THE LOWERING OF SURFACE DEW POINTS BACK UPPER 60S AND LOWER
70S PER GUIDANCE WILL KEEP HI NUMBERS UP IN THE 105-115 ACROSS
MUCH OF THE AREA THU AND FRI AFTERNOONS. WITH OVERNIGHT HEAT
INDEX NUMBERS ONLY FALLING TO AROUND 75 TONIGHT AND THU NIGHT
EXCESSIVE HEAT WARNING CRITERIA FOR ALL OTHER COUNTIES
SURROUNDING COOK WHICH HAS IT/S OWN SET FOR THE CITY WILL BE
REACHED SO ADVISORY EXPANDED ACROSS THE ENTIRE AREA.
HEAT AND HUMIDITY RESULT IN LARGE VALUES OF POTENTIAL INSTABILITY
BUT LOW LEVEL FOCUS AND MID-UPPER DISTURBANCES LACKING THUS ONLY
SLIGHT CHANCES OF ISOLATED TS IF ALL INGREDIENTS COME TOGETHER AT
THE RIGHT TIME AT A PARTICULAR SPOT. THUS...POP NUMBERS TOO LOW
FOR ANY MENTION OF EVEN SLIGHT CHANCE UNTIL FRI NIGHT WITH THE
COOL FRONT MOVING INTO NORTHERN IL. MODELS NOT BULLISH WITH
PUSHING THIS BOUNDARY FURTHER S SAT OR SUN SO WILL HAVE SLIGHT
CHANCE TO LOW END CHANCE POPS GOING ALL OR PARTS OF THE FA FOR
SAT THROUGH MON UNTIL BOUNDARY FINALLY GETS SHOVED ACROSS CENTRAL
TO SOUTHERN IL TAKING LOW LEVEL MOISTURE POOLED ON EITHER SIDE OF
IT OUT OF THE LOCAL FA.
TRS
&&
.CLIMATE...
520 AM CDT
RECORDS...
CHICAGO
WED JUL 4 MAX 102 1911 MIN 80 1921
THU JUL 5 MAX 102 1911 MIN 82 1911
FRI JUL 6 MAX 99 1988 MIN 80 2977
ROCKFORD
WED JUL 4 MAX 101 1911 MIN 77 1977
THU JUL 5 MAX 100 1911 MIN 77 1911
FRI JUL 6 MAX 102 1936 MIN 73 1948
THE ALL TIME RECORD HIGH FOR CHICAGO IS 105 ON JULY 24 1934...
AND FOR ROCKFORD IS 112 ON JULY 14 1936.
FOR CHICAGO THE MOST CONSECUTIVE 100 DEGREE OR HIGHER DAYS IS
THREE...JULY 3RD THROUGH 5TH OF 1911...AND ALSO AUGUST 4TH
THROUGH 6TH OF 1947.
FOR ROCKFORD THE MOST CONSECUTIVE 100 DEGREE OR HIGHER DAYS IS
NINE...JULY 6TH THROUGH 14TH OF 1936.
IZZI/TRS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* NONE.
JEE
//DISCUSSION...UPDATED 18Z...
A LARGE RIDGE EXTENDS ACROSS THE REGION WITH LIGHT W TO SW WINDS
THIS AFTERNOON. MIXING HAS BEEN SLOW THUS FAR TODAY...BUT GUSTS
HAVE DEVELOPED AT ORD AND MDW. BASED ON OBS AND CU
DEVELOPMENT...KEPT WIND GUSTS CONFINED TO ORD AND MDW...BUT MAY
SEE A FEW SPORADIC GUSTS AT GYY. LATEST SATELLITE IMAGERY SHOWS CU
IS DEVELOPING OVER EXTREME NE IL AND NW IN. MORE INTENSE CU
DEVELOPMENT CAN BE FOUND EAST OF VPZ AND IN SOUTHERN IROQUOIS AND
FORD COUNTIES. EXPECTING FEW TO SCT CU TO DEVELOP PRIMARILY OVER
THE EASTERN TERMINALS. CU BASES MAY BE LOWER THAN INDICATED...IN
THE 050-070 RANGE...BUT VFR EITHER WAY.
EXPECTING A LAKE BREEZE TO DEVELOP IMMEDIATELY ALONG THE LAKESHORE
AROUND 00Z AND REMAIN MORE OR LESS RIGHT ALONG THE LAKE SHORE.
WHILE THE LAKE BREEZE WILL NOT AFFECT ORD/MDW WINDS...MAY SEE
ISOLATED CONVECTION FORM ALONG IT. THE LATEST RUC ANALYSIS
INDICATES VERY LITTLE CIN AND OVER 3000 J/KG OF CAPE ALONG THE
LAKESHORE. IN THIS VERY UNSTABLE ENVIRONMENT...ANY FORCING FEATURE
SUCH AS THE LAKE BREEZE COULD LEAD TO A THUNDERSTORM OR TWO.
STEERING FLOW FOR THE STORMS IS NORTHWEST...THEREFORE GOING WITH A
DRY FORECAST FOR ORD. HOWEVER...IF THE LAKE BREEZE PUSHES FARTHER
INLAND THAN EXPECTED...TS MAY FORM NEAR ORD/MDW.
WINDS AND CU DIMINISH AND WINDS BECOME SW TONIGHT. A SIMILAR
SITUATION IS EXPECTED TOMORROW WITH WEST WINDS...GUSTS DEVELOPING
IN THE LATE MORNING...AND SCT VFR CU DEVELOPMENT.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
* THURSDAY NIGHT...VFR.
* FRIDAY...VFR. POSSIBLE LAKE BREEZE IN THE AFTERNOON.
* FRIDAY NIGHT THROUGH MONDAY...VFR. SLIGHT CHANCE OF TSRA.
* TUESDAY...VFR.
&&
.MARINE...
250 PM CDT
A WEAK COLD FRONT HAS BECOME NEARLY STATIONARY OVER CENTRAL LAKE
MICHIGAN THIS AFTERNOON...BUT WILL LIFT BACK NORTH TONIGHT AS LOW
PRESSURE OVER THE EASTERN DAKOTAS AND CANADIAN PRAIRIES LIFTS TOWARD
HUDSON BAY. THE LOW WILL CONTINUE EAST ACROSS HUDSON BAY THURSDAY
AND THURSDAY NIGHT...WITH A COLD FRONT TRAILING ACROSS THE WESTERN
LAKES REGION AND SLIDING SOUTH DOWN LAKE MICHIGAN AND SETTLING
ACROSS THE SOUTH END BY EARLY FRIDAY. THE FRONT WILL SLOW BRIEFLY
FRIDAY NIGHT AS A WEAK SURFACE WAVE RIPPLES EAST ALONG THE FRONT...
WITH NORTHERLY FLOW THEN STRENGTHENING SATURDAY AS HIGH PRESSURE
BUILDS ACROSS THE UPPER MIDWEST AND NORTHERN GREAT LAKES.
WINDS WILL GENERALLY BE ON THE LIGHT SIDE OUTSIDE OF ANY
THUNDERSTORM GUSTS UNTIL SATURDAY...WHEN THE TIGHTENING NORTHERLY
GRADIENT AND PUSH OF SOMEWHAT COOLER AIR RESULTS IN NORTH-NORTHEAST
WINDS INCREASING INTO THE 15-20 KT RANGE PERHAPS WITH A FEW GUSTS IN
THE 20-25 KT RANGE SATURDAY INTO SATURDAY NIGHT.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...EXCESSIVE HEAT WARNING...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-
ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-
ILZ022-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 10 PM FRIDAY.
IN...EXCESSIVE HEAT WARNING...INZ001-INZ002-INZ010-INZ011-INZ019
UNTIL 10 PM FRIDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
251 PM CDT WED JUL 4 2012
.DISCUSSION...
1038 AM CDT
UPDATE FOR REST OF TODAY...
ONLY MINIMAL TWEAKS TO OFFICIAL FORECAST GRID SET MADE BASED ON
NEW GUIDANCE COMING IN. THIS RESULTS IN LITTLE OR NO EFFECT ON
DERIVED TEXT PRODUCTS. SO...CONTINUED VERY HOT AND HUMID.
QUESTIONABLE IF LAKE BREEZE DEVELOPS AND MAKE IT TO THE SHORE THIS
AFTERNOON. LATEST GUIDANCE KEEPS THE LOW LEVEL WINDS OUT OF THE
WSW-W UP AROUND 10 KT THROUGH 00Z WHICH WOULD LIKELY KEEP THE LAKE
BREEZE FOR MAKING AN APPEARANCE. CURRENTLY FORECAST DOES NOT HAVE
IT AT THE SHORE TIL AROUND 23Z SO EVEN IF DOES MAKE ANY PROGRESS
ASHORE IT WILL NOT HAVE ANY AFFECT ON MAX TEMPS DUE TO LATE IN
DAY TIMING.
AN SLIM CHANCE OF A THUNDERSTORM OR TWO DOES STILL EXIST DURING
THE LATE AFTERNOON THROUGH MID EVENING ACROSS NE IL AND NW IND AS
THIS AXIS OF MAX INSTABILITY WILL EXTEND SE OUT OF WI. BESIDES
POSSIBILITY OF A LAKE BREEZE BOUNDARY CLOSE TO THE SHORE WILL NOT
BE ANY SURFACE FEATURES TO ACT AS A FOCUS LOW LEVEL CONVERGENCE
AND FORCED UVV. ALSO DO NOT SEE ANYTHING UPSTREAM IN MODELS OR
SATELLITE LOOPS TO PROVIDE MID -UPPER LEVEL SUPPORT.
THERE IS A SHORT WAVE THAT GENERATED A FEW THUNDERSTORMS AROUND
MSP DURING THE EARLY MORNING CURRENTLY TURNING FROM ESE TO SE
ACROSS SOUTHERN WI. THIS DISTURBANCE IS EXPECTED TO BE E OF NE IL
BY EARLY AFTERNOON AND E OF NW IND BY MID AFTERNOON. DO NOT SEE
ENOUGH TO COMPLETELY PULL THE SLIGHT CHANCE POPS CURRENTLY IN THE
FORECAST FOR LATE AFTERNOON THROUGH MID EVENING ACROSS THE NE
QUARTER OF THE FA SO WILL LET RIDE.
TRS
//PREV DISCUSSION...
356 AM CDT
GOING TO CALL A QUICK AUDIBLE BEFORE SENDING OUT ZFP/PUBLISHING
GRIDS...
MID/HIGH CLOUDINESS CONTINUES TO EXPAND OVER WESTERN WISCONSIN AND
SE MINNESOTA. THE 06Z WRF-NAM AND RAP SEEM TO HAVE A GOOD HANDLE
ON THIS MOISTURE. BASED ON LATEST SATELLITE TRENDS AND THIS MODEL
GUIDANCE HAVE OPTED TO INCREASE SKY COVER IN THE GRIDS THROUGH
EARLY AFTERNOON AND ALSO LOWERED TEMPS A FEW DEGREES FROM THE
VALUES DISCUSSED BELOW.
IZZI
//PREV DISCUSSION...
331 AM CDT
ONCE AGAIN TODAY THE PRIMARY FORECAST CHALLENGE IS THE HEAT AND
RESULTANT HEADLINE DECISIONS...WITH A LESSER CONCERN ABOUT
CONVECTIVE POTENTIAL THE NEXT COUPLE OF DAYS.
BEFORE JUMPING INTO FORECAST WANTED TO DO A QUICK REFRESHER FOR WHAT
OUR HEAT ADVISORY AND WARNING CRITERIA IS. FIRST...EVERYWHERE THE
HEAT ADVISORY CRITERIA IS MAXIMUM HEAT INDICES AT OR ABOVE 105
DEGREES. THE HEAT WARNING CRITERIA IS MUCH MORE COMPLEX.
FIRST...OUTSIDE OF COOK COUNTY THE CRITERIA IS AT LEAST 48 HOURS
WITH MAX HEAT INDICES 110F+ WITH MIN HEAT INDICES OF 75 EACH
NIGHT...OR AN EXCESSIVE HEAT WARNING CAN BE ISSUED FOR 4 CONSECUTIVE
DAYS OF MAX HEAT INDICES 105F+ AND MIN HEAT INDICES 75F+. FOR COOK
COUNTY THERE ARE 3 POSSIBLE TRIGGERS FOR A HEAT WARNING. 1) 3 DAYS
OF MAX HEAT INDEX 100F+ WITH 85% SUNSHINE 2 OF THE DAYS OR NIGHT
TIME HEAT INDICES 80F+ OR 2) 2 DAYS OF MAX HEAT INDEX 105F+ OR 3) 1
DAY OF MAX HEAT INDEX 110F+. WANTED TO SPELL OUT THE CRITERIA SINCE
ITS NOT STRAIGHT FORWARD AND SINCE HEADLINE DECISIONS WERE A BIG
FOCUS OF THIS MORNING`S FORECAST.
AFTER CLOUDS AND CONVECTIVE OUTFLOW HELD TEMPS DOWN A BIT
TUESDAY...CONFIDENCE IS HIGHER TODAY THAT TEMPS WILL CRACK THE
CENTURY MARK IN MANY AREAS. ALREADY SEEING 20M 500MB HEIGHT RISES AT
ILX/DVN WITH MODEL FORECASTING HEIGHT RISES OF ANOTHER 20M OR SO
DURING THE NEXT 24 HOURS...INDICATIVE OF A STRENGTHENING UPPER LEVEL
RIDGE. UNLIKE YESTERDAY...THE THREAT OF CLOUD COVER AND CONVECTIVE
OUTFLOW MUCKING THINGS UP APPEARS LOWER. IN ADDITION...WRF-NAM AND
ECMWF 850MB AND 925MB TEMPS STRONGLY SUPPORT TEMPS CLIMBING INTO THE
99-104 RANGE THIS AFTERNOON...WHILE THE GFS REMAINS ALMOST OBLIVIOUS
AS TO WHAT IS GOING ON NOW LET ALONE WHAT MAY HAPPEN. THURSDAY LOOKS
TO BE A COUPLE OF DEGREES WARMER STILL WITH 925MB TEMPS PROGGED TO
WARM 1-2C AND 500MB HEIGHTS TO INCREASE A BIT MORE SETTING THE STAGE
FOR WHAT COULD BE THE HOTTEST AMBIENT AIR TEMPERATURES SINCE THE
1995 KILLER HEAT WAVE AND POSSIBLY EVEN FLIRTING WITH CHICAGO`S ALL
TIME RECORD HIGH OF 105F. IT DOES APPEAR AS THOUGH WEAK LAKE BREEZE
COULD DEVELOP LATE THIS AFTERNOON AND AGAIN THURSDAY LATE AFTERNOON
PROVIDING A BIT OF RELIEF CLOSE TO THE LAKE...BUT THE RELIEF SHOULD
BE SHORT LIVED WITH LAND BREEZE SENDING EVENING TEMPS CLIMBING. IN
FACT...NIGHTTIME LOWS IN THE CITY WILL LIKELY BE IN THE LOW TO MID
80S WITH THE MAJORITY OF THE NIGHT EXPERIENCING HEAT INDICES IN THE
90S (STILL 94 HEAT INDEX DOWNTOWN AT 220AM THIS MORNING).
THE BIGGER QUESTION MARK REVOLVES AROUND DEW POINTS AND HOW MUCH
PERSPIRING CORN CAN COMPENSATE FOR WHAT LOOKS TO BE DEEP AFTERNOON
MIXING. ADMITTEDLY...OUR SKILL AT DEW POINT FORECASTING IS NOT ALL
THAT HIGH WITH MEAN ABSOLUTE ERRORS OF 3-4F FOR 24 HOUR DEW POINT
FORECASTS...WHICH LEAVES OPEN A GOOD 6-8F SIZED RANGE OF POSSIBILITY
FOR AFTERNOON DEW POINTS WHICH HAS MAJOR IMPLICATIONS ON HEAT
INDICES. BASED ON CURRENT DEW POINT FORECASTS HAVE AFTERNOON HEAT
INDICES GENERALLY PEAKING BETWEEN 105-110F ACROSS THE AREA WITH A
FEW OF THE TYPICALLY HOTTER SPOTS GETTING A BIT ABOVE 110F. ITS
WORTH NOTING A 3-4F ERROR IN DEW POINTS WOULD CORRESPOND TO ABOUT A
5F ERROR IN FORE CASTED HEAT INDICES.
CONSIDERING EVERYTHING DISCUSSED IN DEPTH ABOVE...HAVE OPTED TO
CONTINUE WITH A HEAT ADVISORY FOR THE MAJORITY OF THE CWA AS HEAT
INDICES FELL SHORT OF THE 105F ADVISORY THRESHOLD THE PAST 2 DAYS
MAKING IT IMPOSSIBLE TO REACH THE 4 DAY CRITERIA FOR A HEAT WARNING.
IF DEW POINTS STAY UP MORE THAN FORECAST AND HEAT INDICES GET ABOVE
110F THIS AFTERNOON THEN DAY SHIFT MAY NEED TO CONSIDER UPGRADING TO
AN EXCESSIVE HEAT WARNING FOR THURSDAY AND/OR FRIDAY...BUT GIVEN LOW
CONFIDENCE IN THAT SCENARIO THINK AN ADVISORY IS THE BEST COURSE OF
ACTION FOR NOW. FOR COOK COUNTY AND THE CITY OF CHICAGO WHERE
WARNING CRITERIA IS LOWER DUE TO URBAN HEAT ISLAND AND POPULATION
DENSITY/SOCIOECONOMIC CONCERNS WILL BE UPGRADING TO AN EXCESSIVE HEAT
WARNING THROUGH FRIDAY AS WE WILL LIKELY MEET 2 AND 3 DAY CRITERIA
AND COULD EVEN MEET THE 1 DAY WARNING CRITERIA. WHILE NOT UPGRADING
TO A WARNING FOR MOST OF THE AREA DOES LEAVE US AS AN ISLAND
SURROUNDED BY WARNINGS...IT IS VERY POSSIBLE THAT DEW POINTS COULD
MIX OUT AND WE NOT EVEN REACH ADVISORY CRITERIA THIS AFTERNOON LET
ALONE WARNING CRITERIA. ALSO...AN ADVISORY OUTLYING AREAS AND
WARNING FOR COOK COUNTY WILL FURTHER HIGHLIGHT THAT CONDITIONS WILL
BE CONSIDERABLY MORE SEVERE IN THE CITY OF CHICAGO DUE TO THE URBAN
HEAT ISLAND. NOT ONLY WILL DAYTIME TEMPS AND HEAT INDICES TO BE A
FEW DEGREES HIGHER BUT NIGHTTIME HEAT INDICES WILL BE NEARLY 20F
HIGHER ADDING TO THE CUMULATIVE EFFECTS AND DANGER OF THE HEAT WAVE.
FORECAST CONFIDENCE DIMINISHES HEADING INTO FRIDAY AS NUMERICAL
GUIDANCE HAS BEEN TRENDING FASTER WITH WEAK COLD FRONTAL PASSAGE
THAT WILL LIKELY BE SIGNIFICANTLY AUGMENTED BY THE LAKE. ECMWF
REMAINS THE SLOWEST WITH MUCH OF THE AFTERNOON SPENT IN THE WARM
SECTOR WHILE GFS/GEM/WRF-NAM ARE FASTER WITH THE LAKE ENHANCED FROPA
WHICH WOULD RESULT IN COOLER HIGHS...ESPECIALLY NEAR THE LAKE. TOOK
A COMPROMISE APPROACH FOR NOW WITH FROPA STARTING NEAR UGN AROUND
18Z BEFORE SPREADING SOUTH AND WEST FARTHER INLAND. WHILE
TEMPERATURES MAY END UP A FEW DEGREES COOLER ON FRIDAY...DEW POINT
POOLING MAY OFFSET ANY SLIGHT LOWERING OF TEMPS AND RESULT IN HEAT
INDICES EVEN HIGHER THAN THURSDAY OR FRIDAY. TEMP/HEAT INDEX
FORECAST FOR FRIDAY IS GOING TO HINGE HEAVILY ON FROPA TIMING...ANY
SPEEDING UP OF FROPA COULD RESULT IN TEMPS BEING COOLER AND POSSIBLY
AN EARLIER ENDING TO THE HEAT HEADLINES.
REGARDING THUNDERSTORM CHANCES...THERE REMAINS A VERY SMALL CHANCE
OF A THUNDERSTORM BLOWING UP ON THE LAKE BREEZE CONVERGENCE ZONE
LATER THIS AFTERNOON AS BOUNDARY LAYER HEATS UP AND ERASES
CONVECTIVE INHIBITION. RISING UPPER LEVEL HEIGHT AND IMPLIED
SUBSIDENCE CERTAINLY ARE NOT PLUSES FOR THE T-STORM POTENTIAL AND
THINK CHANCES MAY EVEN BE A BIT LOWER THAN 20%...HOWEVER...GIVEN THE
VERY STRONG INSTABILITY (ML CAPES LIKELY OVER 5000 J/KG) AND 0-8KM
BULK SHEAR VALUES NEARING 40KT THE CONDITIONAL SEVERE POTENTIAL IS
VERY HIGH CONTINGENT ON A STORM DEVELOPING. GIVEN THIS FELT IT WAS
BEST TO KEEP 20 POPS GOING 21-03Z. STILL A SMALL THREAT OF A STORM
GOING UP ON LAKE BREEZE THURSDAY AFTERNOON AS WELL...BUT WITH UPPER
HEIGHTS RISING FURTHER AND NO APPARENT TRIGGER...PLUS WEAKER DEEP
LAYER SHEAR/CONDITIONAL SEVERE THREAT HAVE OPTED TO KEEP FORECAST
DRY FOR NOW...BUT THIS WILL NEED TO BE RE-ACCESSED IN SUBSEQUENT
FORECASTS.
INITIALLY EXPECTING FROPA FRIDAY TO BE DRY AS FRONT SHOULD BE
SHALLOW AND UPPER HEIGHTS VERY HIGH...BUT WITH TIME THE UPPER RIDGE
WILL GET BEAT DOWN OVER THE WEEKEND WITH GRADUALLY
INCREASING...THOUGH STILL RATHER LOW...CHANCES FOR SHOWERS AND
THUNDERSTORMS AS BOUNDARY HANGS UP IN THE AREA. MAJORITY OF THE
WEEKEND SHOULD END UP DRY...HOWEVER IT COULD RAIN AT ANY TIME WHICH
NECESSITATES CARRYING POPS EACH PERIOD UNFORTUNATELY. MUCH MORE
SEASONABLE TEMPS AND COMFORTABLE HUMIDITY LEVELS ARE EXPECTED BY
LATE IN THE WEEKEND INTO NEXT WEEK. ANY AREA THAT DOES NOT PICK UP
SIGNIFICANT RAINFALL THIS WEEKEND WILL BE UNLIKELY TO SEE ANY
DROUGHT RELIEF NEXT WEEK AS ALL CURRENT INDICATIONS IN MEDIUM RANGE
GUIDANCE SUGGESTS WE WILL BE AN ANOTHER DRY PATTERN WITH LITTLE HOPE
FOR APPRECIABLE PRECIP UNTIL AT LEAST THE MIDDLE OF JULY.
IZZI
&&
.CLIMATE...
520 AM CDT
CHICAGO ROCKFORD
WED 102 80 101 77
1911 1921 1911 1977
THU 102 82 100 77
1911 1911 1911 1911
FRI 99 80 102 73
1988 1977 1936 1948
THE ALL TIME RECORD HIGH FOR CHICAGO IS 105 SET BACK ON JULY 24
1934...AND FOR ROCKFORD IS 112 SET ON JULY 14 1936.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* NONE.
JEE
//DISCUSSION...UPDATED 18Z...
A LARGE RIDGE EXTENDS ACROSS THE REGION WITH LIGHT W TO SW WINDS
THIS AFTERNOON. MIXING HAS BEEN SLOW THUS FAR TODAY...BUT GUSTS
HAVE DEVELOPED AT ORD AND MDW. BASED ON OBS AND CU
DEVELOPMENT...KEPT WIND GUSTS CONFINED TO ORD AND MDW...BUT MAY
SEE A FEW SPORADIC GUSTS AT GYY. LATEST SATELLITE IMAGERY SHOWS CU
IS DEVELOPING OVER EXTREME NE IL AND NW IN. MORE INTENSE CU
DEVELOPMENT CAN BE FOUND EAST OF VPZ AND IN SOUTHERN IROQUOIS AND
FORD COUNTIES. EXPECTING FEW TO SCT CU TO DEVELOP PRIMARILY OVER
THE EASTERN TERMINALS. CU BASES MAY BE LOWER THAN INDICATED...IN
THE 050-070 RANGE...BUT VFR EITHER WAY.
EXPECTING A LAKE BREEZE TO DEVELOP IMMEDIATELY ALONG THE LAKESHORE
AROUND 00Z AND REMAIN MORE OR LESS RIGHT ALONG THE LAKE SHORE.
WHILE THE LAKE BREEZE WILL NOT AFFECT ORD/MDW WINDS...MAY SEE
ISOLATED CONVECTION FORM ALONG IT. THE LATEST RUC ANALYSIS
INDICATES VERY LITTLE CIN AND OVER 3000 J/KG OF CAPE ALONG THE
LAKESHORE. IN THIS VERY UNSTABLE ENVIRONMENT...ANY FORCING FEATURE
SUCH AS THE LAKE BREEZE COULD LEAD TO A THUNDERSTORM OR TWO.
STEERING FLOW FOR THE STORMS IS NORTHWEST...THEREFORE GOING WITH A
DRY FORECAST FOR ORD. HOWEVER...IF THE LAKE BREEZE PUSHES FARTHER
INLAND THAN EXPECTED...TS MAY FORM NEAR ORD/MDW.
WINDS AND CU DIMINISH AND WINDS BECOME SW TONIGHT. A SIMILAR
SITUATION IS EXPECTED TOMORROW WITH WEST WINDS...GUSTS DEVELOPING
IN THE LATE MORNING...AND SCT VFR CU DEVELOPMENT.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
* THURSDAY NIGHT...VFR.
* FRIDAY...VFR. POSSIBLE LAKE BREEZE IN THE AFTERNOON.
* FRIDAY NIGHT THROUGH MONDAY...VFR. SLIGHT CHANCE OF TSRA.
* TUESDAY...VFR.
&&
.MARINE...
250 PM CDT
A WEAK COLD FRONT HAS BECOME NEARLY STATIONARY OVER CENTRAL LAKE
MICHIGAN THIS AFTERNOON...BUT WILL LIFT BACK NORTH TONIGHT AS LOW
PRESSURE OVER THE EASTERN DAKOTAS AND CANADIAN PRAIRIES LIFTS TOWARD
HUDSON BAY. THE LOW WILL CONTINUE EAST ACROSS HUDSON BAY THURSDAY
AND THURSDAY NIGHT...WITH A COLD FRONT TRAILING ACROSS THE WESTERN
LAKES REGION AND SLIDING SOUTH DOWN LAKE MICHIGAN AND SETTLING
ACROSS THE SOUTH END BY EARLY FRIDAY. THE FRONT WILL SLOW BRIEFLY
FRIDAY NIGHT AS A WEAK SURFACE WAVE RIPPLES EAST ALONG THE FRONT...
WITH NORTHERLY FLOW THEN STRENGTHENING SATURDAY AS HIGH PRESSURE
BUILDS ACROSS THE UPPER MIDWEST AND NORTHERN GREAT LAKES.
WINDS WILL GENERALLY BE ON THE LIGHT SIDE OUTSIDE OF ANY
THUNDERSTORM GUSTS UNTIL SATURDAY...WHEN THE TIGHTENING NORTHERLY
GRADIENT AND PUSH OF SOMEWHAT COOLER AIR RESULTS IN NORTH-NORTHEAST
WINDS INCREASING INTO THE 15-20 KT RANGE PERHAPS WITH A FEW GUSTS IN
THE 20-25 KT RANGE SATURDAY INTO SATURDAY NIGHT.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...EXCESSIVE HEAT WARNING...ILZ014 UNTIL 6 PM FRIDAY.
HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-ILZ032-
ILZ033-ILZ039 UNTIL 10 PM FRIDAY.
IN...HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 10 PM
FRIDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
246 PM CDT WED JUL 4 2012
.DISCUSSION...
1038 AM CDT
UPDATE FOR REST OF TODAY...
ONLY MINIMAL TWEAKS TO OFFICIAL FORECAST GRID SET MADE BASED ON
NEW GUIDANCE COMING IN. THIS RESULTS IN LITTLE OR NO EFFECT ON
DERIVED TEXT PRODUCTS. SO...CONTINUED VERY HOT AND HUMID.
QUESTIONABLE IF LAKE BREEZE DEVELOPS AND MAKE IT TO THE SHORE THIS
AFTERNOON. LATEST GUIDANCE KEEPS THE LOW LEVEL WINDS OUT OF THE
WSW-W UP AROUND 10 KT THROUGH 00Z WHICH WOULD LIKELY KEEP THE LAKE
BREEZE FOR MAKING AN APPEARANCE. CURRENTLY FORECAST DOES NOT HAVE
IT AT THE SHORE TIL AROUND 23Z SO EVEN IF DOES MAKE ANY PROGRESS
ASHORE IT WILL NOT HAVE ANY AFFECT ON MAX TEMPS DUE TO LATE IN
DAY TIMING.
AN SLIM CHANCE OF A THUNDERSTORM OR TWO DOES STILL EXIST DURING
THE LATE AFTERNOON THROUGH MID EVENING ACROSS NE IL AND NW IND AS
THIS AXIS OF MAX INSTABILITY WILL EXTEND SE OUT OF WI. BESIDES
POSSIBILITY OF A LAKE BREEZE BOUNDARY CLOSE TO THE SHORE WILL NOT
BE ANY SURFACE FEATURES TO ACT AS A FOCUS LOW LEVEL CONVERGENCE
AND FORCED UVV. ALSO DO NOT SEE ANYTHING UPSTREAM IN MODELS OR
SATELLITE LOOPS TO PROVIDE MID -UPPER LEVEL SUPPORT.
THERE IS A SHORT WAVE THAT GENERATED A FEW THUNDERSTORMS AROUND
MSP DURING THE EARLY MORNING CURRENTLY TURNING FROM ESE TO SE
ACROSS SOUTHERN WI. THIS DISTURBANCE IS EXPECTED TO BE E OF NE IL
BY EARLY AFTERNOON AND E OF NW IND BY MID AFTERNOON. DO NOT SEE
ENOUGH TO COMPLETELY PULL THE SLIGHT CHANCE POPS CURRENTLY IN THE
FORECAST FOR LATE AFTERNOON THROUGH MID EVENING ACROSS THE NE
QUARTER OF THE FA SO WILL LET RIDE.
TRS
//PREV DISCUSSION...
356 AM CDT
GOING TO CALL A QUICK AUDIBLE BEFORE SENDING OUT ZFP/PUBLISHING
GRIDS...
MID/HIGH CLOUDINESS CONTINUES TO EXPAND OVER WESTERN WISCONSIN AND
SE MINNESOTA. THE 06Z WRF-NAM AND RAP SEEM TO HAVE A GOOD HANDLE
ON THIS MOISTURE. BASED ON LATEST SATELLITE TRENDS AND THIS MODEL
GUIDANCE HAVE OPTED TO INCREASE SKY COVER IN THE GRIDS THROUGH
EARLY AFTERNOON AND ALSO LOWERED TEMPS A FEW DEGREES FROM THE
VALUES DISCUSSED BELOW.
IZZI
//PREV DISCUSSION...
331 AM CDT
ONCE AGAIN TODAY THE PRIMARY FORECAST CHALLENGE IS THE HEAT AND
RESULTANT HEADLINE DECISIONS...WITH A LESSER CONCERN ABOUT
CONVECTIVE POTENTIAL THE NEXT COUPLE OF DAYS.
BEFORE JUMPING INTO FORECAST WANTED TO DO A QUICK REFRESHER FOR WHAT
OUR HEAT ADVISORY AND WARNING CRITERIA IS. FIRST...EVERYWHERE THE
HEAT ADVISORY CRITERIA IS MAXIMUM HEAT INDICES AT OR ABOVE 105
DEGREES. THE HEAT WARNING CRITERIA IS MUCH MORE COMPLEX.
FIRST...OUTSIDE OF COOK COUNTY THE CRITERIA IS AT LEAST 48 HOURS
WITH MAX HEAT INDICES 110F+ WITH MIN HEAT INDICES OF 75 EACH
NIGHT...OR AN EXCESSIVE HEAT WARNING CAN BE ISSUED FOR 4 CONSECUTIVE
DAYS OF MAX HEAT INDICES 105F+ AND MIN HEAT INDICES 75F+. FOR COOK
COUNTY THERE ARE 3 POSSIBLE TRIGGERS FOR A HEAT WARNING. 1) 3 DAYS
OF MAX HEAT INDEX 100F+ WITH 85% SUNSHINE 2 OF THE DAYS OR NIGHT
TIME HEAT INDICES 80F+ OR 2) 2 DAYS OF MAX HEAT INDEX 105F+ OR 3) 1
DAY OF MAX HEAT INDEX 110F+. WANTED TO SPELL OUT THE CRITERIA SINCE
ITS NOT STRAIGHT FORWARD AND SINCE HEADLINE DECISIONS WERE A BIG
FOCUS OF THIS MORNING`S FORECAST.
AFTER CLOUDS AND CONVECTIVE OUTFLOW HELD TEMPS DOWN A BIT
TUESDAY...CONFIDENCE IS HIGHER TODAY THAT TEMPS WILL CRACK THE
CENTURY MARK IN MANY AREAS. ALREADY SEEING 20M 500MB HEIGHT RISES AT
ILX/DVN WITH MODEL FORECASTING HEIGHT RISES OF ANOTHER 20M OR SO
DURING THE NEXT 24 HOURS...INDICATIVE OF A STRENGTHENING UPPER LEVEL
RIDGE. UNLIKE YESTERDAY...THE THREAT OF CLOUD COVER AND CONVECTIVE
OUTFLOW MUCKING THINGS UP APPEARS LOWER. IN ADDITION...WRF-NAM AND
ECMWF 850MB AND 925MB TEMPS STRONGLY SUPPORT TEMPS CLIMBING INTO THE
99-104 RANGE THIS AFTERNOON...WHILE THE GFS REMAINS ALMOST OBLIVIOUS
AS TO WHAT IS GOING ON NOW LET ALONE WHAT MAY HAPPEN. THURSDAY LOOKS
TO BE A COUPLE OF DEGREES WARMER STILL WITH 925MB TEMPS PROGGED TO
WARM 1-2C AND 500MB HEIGHTS TO INCREASE A BIT MORE SETTING THE STAGE
FOR WHAT COULD BE THE HOTTEST AMBIENT AIR TEMPERATURES SINCE THE
1995 KILLER HEAT WAVE AND POSSIBLY EVEN FLIRTING WITH CHICAGO`S ALL
TIME RECORD HIGH OF 105F. IT DOES APPEAR AS THOUGH WEAK LAKE BREEZE
COULD DEVELOP LATE THIS AFTERNOON AND AGAIN THURSDAY LATE AFTERNOON
PROVIDING A BIT OF RELIEF CLOSE TO THE LAKE...BUT THE RELIEF SHOULD
BE SHORT LIVED WITH LAND BREEZE SENDING EVENING TEMPS CLIMBING. IN
FACT...NIGHTTIME LOWS IN THE CITY WILL LIKELY BE IN THE LOW TO MID
80S WITH THE MAJORITY OF THE NIGHT EXPERIENCING HEAT INDICES IN THE
90S (STILL 94 HEAT INDEX DOWNTOWN AT 220AM THIS MORNING).
THE BIGGER QUESTION MARK REVOLVES AROUND DEW POINTS AND HOW MUCH
PERSPIRING CORN CAN COMPENSATE FOR WHAT LOOKS TO BE DEEP AFTERNOON
MIXING. ADMITTEDLY...OUR SKILL AT DEW POINT FORECASTING IS NOT ALL
THAT HIGH WITH MEAN ABSOLUTE ERRORS OF 3-4F FOR 24 HOUR DEW POINT
FORECASTS...WHICH LEAVES OPEN A GOOD 6-8F SIZED RANGE OF POSSIBILITY
FOR AFTERNOON DEW POINTS WHICH HAS MAJOR IMPLICATIONS ON HEAT
INDICES. BASED ON CURRENT DEW POINT FORECASTS HAVE AFTERNOON HEAT
INDICES GENERALLY PEAKING BETWEEN 105-110F ACROSS THE AREA WITH A
FEW OF THE TYPICALLY HOTTER SPOTS GETTING A BIT ABOVE 110F. ITS
WORTH NOTING A 3-4F ERROR IN DEW POINTS WOULD CORRESPOND TO ABOUT A
5F ERROR IN FORE CASTED HEAT INDICES.
CONSIDERING EVERYTHING DISCUSSED IN DEPTH ABOVE...HAVE OPTED TO
CONTINUE WITH A HEAT ADVISORY FOR THE MAJORITY OF THE CWA AS HEAT
INDICES FELL SHORT OF THE 105F ADVISORY THRESHOLD THE PAST 2 DAYS
MAKING IT IMPOSSIBLE TO REACH THE 4 DAY CRITERIA FOR A HEAT WARNING.
IF DEW POINTS STAY UP MORE THAN FORECAST AND HEAT INDICES GET ABOVE
110F THIS AFTERNOON THEN DAY SHIFT MAY NEED TO CONSIDER UPGRADING TO
AN EXCESSIVE HEAT WARNING FOR THURSDAY AND/OR FRIDAY...BUT GIVEN LOW
CONFIDENCE IN THAT SCENARIO THINK AN ADVISORY IS THE BEST COURSE OF
ACTION FOR NOW. FOR COOK COUNTY AND THE CITY OF CHICAGO WHERE
WARNING CRITERIA IS LOWER DUE TO URBAN HEAT ISLAND AND POPULATION
DENSITY/SOCIOECONOMIC CONCERNS WILL BE UPGRADING TO AN EXCESSIVE HEAT
WARNING THROUGH FRIDAY AS WE WILL LIKELY MEET 2 AND 3 DAY CRITERIA
AND COULD EVEN MEET THE 1 DAY WARNING CRITERIA. WHILE NOT UPGRADING
TO A WARNING FOR MOST OF THE AREA DOES LEAVE US AS AN ISLAND
SURROUNDED BY WARNINGS...IT IS VERY POSSIBLE THAT DEW POINTS COULD
MIX OUT AND WE NOT EVEN REACH ADVISORY CRITERIA THIS AFTERNOON LET
ALONE WARNING CRITERIA. ALSO...AN ADVISORY OUTLYING AREAS AND
WARNING FOR COOK COUNTY WILL FURTHER HIGHLIGHT THAT CONDITIONS WILL
BE CONSIDERABLY MORE SEVERE IN THE CITY OF CHICAGO DUE TO THE URBAN
HEAT ISLAND. NOT ONLY WILL DAYTIME TEMPS AND HEAT INDICES TO BE A
FEW DEGREES HIGHER BUT NIGHTTIME HEAT INDICES WILL BE NEARLY 20F
HIGHER ADDING TO THE CUMULATIVE EFFECTS AND DANGER OF THE HEAT WAVE.
FORECAST CONFIDENCE DIMINISHES HEADING INTO FRIDAY AS NUMERICAL
GUIDANCE HAS BEEN TRENDING FASTER WITH WEAK COLD FRONTAL PASSAGE
THAT WILL LIKELY BE SIGNIFICANTLY AUGMENTED BY THE LAKE. ECMWF
REMAINS THE SLOWEST WITH MUCH OF THE AFTERNOON SPENT IN THE WARM
SECTOR WHILE GFS/GEM/WRF-NAM ARE FASTER WITH THE LAKE ENHANCED FROPA
WHICH WOULD RESULT IN COOLER HIGHS...ESPECIALLY NEAR THE LAKE. TOOK
A COMPROMISE APPROACH FOR NOW WITH FROPA STARTING NEAR UGN AROUND
18Z BEFORE SPREADING SOUTH AND WEST FARTHER INLAND. WHILE
TEMPERATURES MAY END UP A FEW DEGREES COOLER ON FRIDAY...DEW POINT
POOLING MAY OFFSET ANY SLIGHT LOWERING OF TEMPS AND RESULT IN HEAT
INDICES EVEN HIGHER THAN THURSDAY OR FRIDAY. TEMP/HEAT INDEX
FORECAST FOR FRIDAY IS GOING TO HINGE HEAVILY ON FROPA TIMING...ANY
SPEEDING UP OF FROPA COULD RESULT IN TEMPS BEING COOLER AND POSSIBLY
AN EARLIER ENDING TO THE HEAT HEADLINES.
REGARDING THUNDERSTORM CHANCES...THERE REMAINS A VERY SMALL CHANCE
OF A THUNDERSTORM BLOWING UP ON THE LAKE BREEZE CONVERGENCE ZONE
LATER THIS AFTERNOON AS BOUNDARY LAYER HEATS UP AND ERASES
CONVECTIVE INHIBITION. RISING UPPER LEVEL HEIGHT AND IMPLIED
SUBSIDENCE CERTAINLY ARE NOT PLUSES FOR THE T-STORM POTENTIAL AND
THINK CHANCES MAY EVEN BE A BIT LOWER THAN 20%...HOWEVER...GIVEN THE
VERY STRONG INSTABILITY (ML CAPES LIKELY OVER 5000 J/KG) AND 0-8KM
BULK SHEAR VALUES NEARING 40KT THE CONDITIONAL SEVERE POTENTIAL IS
VERY HIGH CONTINGENT ON A STORM DEVELOPING. GIVEN THIS FELT IT WAS
BEST TO KEEP 20 POPS GOING 21-03Z. STILL A SMALL THREAT OF A STORM
GOING UP ON LAKE BREEZE THURSDAY AFTERNOON AS WELL...BUT WITH UPPER
HEIGHTS RISING FURTHER AND NO APPARENT TRIGGER...PLUS WEAKER DEEP
LAYER SHEAR/CONDITIONAL SEVERE THREAT HAVE OPTED TO KEEP FORECAST
DRY FOR NOW...BUT THIS WILL NEED TO BE RE-ACCESSED IN SUBSEQUENT
FORECASTS.
INITIALLY EXPECTING FROPA FRIDAY TO BE DRY AS FRONT SHOULD BE
SHALLOW AND UPPER HEIGHTS VERY HIGH...BUT WITH TIME THE UPPER RIDGE
WILL GET BEAT DOWN OVER THE WEEKEND WITH GRADUALLY
INCREASING...THOUGH STILL RATHER LOW...CHANCES FOR SHOWERS AND
THUNDERSTORMS AS BOUNDARY HANGS UP IN THE AREA. MAJORITY OF THE
WEEKEND SHOULD END UP DRY...HOWEVER IT COULD RAIN AT ANY TIME WHICH
NECESSITATES CARRYING POPS EACH PERIOD UNFORTUNATELY. MUCH MORE
SEASONABLE TEMPS AND COMFORTABLE HUMIDITY LEVELS ARE EXPECTED BY
LATE IN THE WEEKEND INTO NEXT WEEK. ANY AREA THAT DOES NOT PICK UP
SIGNIFICANT RAINFALL THIS WEEKEND WILL BE UNLIKELY TO SEE ANY
DROUGHT RELIEF NEXT WEEK AS ALL CURRENT INDICATIONS IN MEDIUM RANGE
GUIDANCE SUGGESTS WE WILL BE AN ANOTHER DRY PATTERN WITH LITTLE HOPE
FOR APPRECIABLE PRECIP UNTIL AT LEAST THE MIDDLE OF JULY.
IZZI
&&
.CLIMATE...
520 AM CDT
CHICAGO ROCKFORD
WED 102 80 101 77
1911 1921 1911 1977
THU 102 82 100 77
1911 1911 1911 1911
FRI 99 80 102 73
1988 1977 1936 1948
THE ALL TIME RECORD HIGH FOR CHICAGO IS 105 SET BACK ON JULY 24
1934...AND FOR ROCKFORD IS 112 SET ON JULY 14 1936.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* NONE.
JEE
//DISCUSSION...UPDATED 18Z...
A LARGE RIDGE EXTENDS ACROSS THE REGION WITH LIGHT W TO SW WINDS
THIS AFTERNOON. MIXING HAS BEEN SLOW THUS FAR TODAY...BUT GUSTS
HAVE DEVELOPED AT ORD AND MDW. BASED ON OBS AND CU
DEVELOPMENT...KEPT WIND GUSTS CONFINED TO ORD AND MDW...BUT MAY
SEE A FEW SPORADIC GUSTS AT GYY. LATEST SATELLITE IMAGERY SHOWS CU
IS DEVELOPING OVER EXTREME NE IL AND NW IN. MORE INTENSE CU
DEVELOPMENT CAN BE FOUND EAST OF VPZ AND IN SOUTHERN IROQUOIS AND
FORD COUNTIES. EXPECTING FEW TO SCT CU TO DEVELOP PRIMARILY OVER
THE EASTERN TERMINALS. CU BASES MAY BE LOWER THAN INDICATED...IN
THE 050-070 RANGE...BUT VFR EITHER WAY.
EXPECTING A LAKE BREEZE TO DEVELOP IMMEDIATELY ALONG THE LAKESHORE
AROUND 00Z AND REMAIN MORE OR LESS RIGHT ALONG THE LAKE SHORE.
WHILE THE LAKE BREEZE WILL NOT AFFECT ORD/MDW WINDS...MAY SEE
ISOLATED CONVECTION FORM ALONG IT. THE LATEST RUC ANALYSIS
INDICATES VERY LITTLE CIN AND OVER 3000 J/KG OF CAPE ALONG THE
LAKESHORE. IN THIS VERY UNSTABLE ENVIRONMENT...ANY FORCING FEATURE
SUCH AS THE LAKE BREEZE COULD LEAD TO A THUNDERSTORM OR TWO.
STEERING FLOW FOR THE STORMS IS NORTHWEST...THEREFORE GOING WITH A
DRY FORECAST FOR ORD. HOWEVER...IF THE LAKE BREEZE PUSHES FARTHER
INLAND THAN EXPECTED...TS MAY FORM NEAR ORD/MDW.
WINDS AND CU DIMINISH AND WINDS BECOME SW TONIGHT. A SIMILAR
SITUATION IS EXPECTED TOMORROW WITH WEST WINDS...GUSTS DEVELOPING
IN THE LATE MORNING...AND SCT VFR CU DEVELOPMENT.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
* THURSDAY NIGHT...VFR.
* FRIDAY...VFR. POSSIBLE LAKE BREEZE IN THE AFTERNOON.
* FRIDAY NIGHT THROUGH MONDAY...VFR. SLIGHT CHANCE OF TSRA.
* TUESDAY...VFR.
&&
.MARINE...
306 AM...A WEAK COLD FRONT WILL MOVE SOUTH ACROSS LAKE MICHIGAN
TODAY AND WASH OUT AS IT REACHES THE SOUTH/CENTRAL PORTION OF THE
LAKE...MKE/MKG REGION. WHILE WINDS WILL TURN NORTHERLY...SPEEDS
WILL BE FAIRLY LIGHT. AS STRONG LOW PRESSURE MOVES ACROSS CANADA
OVER THE NEXT FEW DAYS...THE GRADIENT WILL RETURN SOUTHERLY WINDS
ACROSS THE LAKE UNTIL FRIDAY MORNING...WHEN A TRAILING COLD FRONT
FROM THIS LOW MOVES SOUTH ACROSS THE LAKE. WITH HIGH PRESSURE
BUILDING ACROSS THE MIDWEST/UPPER LAKES BEHIND THIS FRONT...
APPEARS THERE WILL BE A PROLONGED PERIOD OF NORTHERLY WINDS WITH
SPEEDS IN THE 10-20 KT RANGE...ESPECIALLY ON THE SOUTH END OF THE
LAKE. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...EXCESSIVE HEAT WARNING...ILZ014 UNTIL 6 PM FRIDAY.
HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-ILZ032-
ILZ033-ILZ039 UNTIL 10 PM FRIDAY.
IN...HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 10 PM
FRIDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1256 PM CDT WED JUL 4 2012
.DISCUSSION...
1038 AM CDT
UPDATE FOR REST OF TODAY...
ONLY MINIMAL TWEAKS TO OFFICIAL FORECAST GRID SET MADE BASED ON
NEW GUIDANCE COMING IN. THIS RESULTS IN LITTLE OR NO EFFECT ON
DERIVED TEXT PRODUCTS. SO...CONTINUED VERY HOT AND HUMID.
QUESTIONABLE IF LAKE BREEZE DEVELOPS AND MAKE IT TO THE SHORE THIS
AFTERNOON. LATEST GUIDANCE KEEPS THE LOW LEVEL WINDS OUT OF THE
WSW-W UP AROUND 10 KT THROUGH 00Z WHICH WOULD LIKELY KEEP THE LAKE
BREEZE FOR MAKING AN APPEARANCE. CURRENTLY FORECAST DOES NOT HAVE
IT AT THE SHORE TIL AROUND 23Z SO EVEN IF DOES MAKE ANY PROGRESS
ASHORE IT WILL NOT HAVE ANY AFFECT ON MAX TEMPS DUE TO LATE IN
DAY TIMING.
AN SLIM CHANCE OF A THUNDERSTORM OR TWO DOES STILL EXIST DURING
THE LATE AFTERNOON THROUGH MID EVENING ACROSS NE IL AND NW IND AS
THIS AXIS OF MAX INSTABILITY WILL EXTEND SE OUT OF WI. BESIDES
POSSIBILITY OF A LAKE BREEZE BOUNDARY CLOSE TO THE SHORE WILL NOT
BE ANY SURFACE FEATURES TO ACT AS A FOCUS LOW LEVEL CONVERGENCE
AND FORCED UVV. ALSO DO NOT SEE ANYTHING UPSTREAM IN MODELS OR
SATELLITE LOOPS TO PROVIDE MID -UPPER LEVEL SUPPORT.
THERE IS A SHORT WAVE THAT GENERATED A FEW THUNDERSTORMS AROUND
MSP DURING THE EARLY MORNING CURRENTLY TURNING FROM ESE TO SE
ACROSS SOUTHERN WI. THIS DISTURBANCE IS EXPECTED TO BE E OF NE IL
BY EARLY AFTERNOON AND E OF NW IND BY MID AFTERNOON. DO NOT SEE
ENOUGH TO COMPLETELY PULL THE SLIGHT CHANCE POPS CURRENTLY IN THE
FORECAST FOR LATE AFTERNOON THROUGH MID EVENING ACROSS THE NE
QUARTER OF THE FA SO WILL LET RIDE.
TRS
//PREV DISCUSSION...
356 AM CDT
GOING TO CALL A QUICK AUDIBLE BEFORE SENDING OUT ZFP/PUBLISHING
GRIDS...
MID/HIGH CLOUDINESS CONTINUES TO EXPAND OVER WESTERN WISCONSIN AND
SE MINNESOTA. THE 06Z WRF-NAM AND RAP SEEM TO HAVE A GOOD HANDLE
ON THIS MOISTURE. BASED ON LATEST SATELLITE TRENDS AND THIS MODEL
GUIDANCE HAVE OPTED TO INCREASE SKY COVER IN THE GRIDS THROUGH
EARLY AFTERNOON AND ALSO LOWERED TEMPS A FEW DEGREES FROM THE
VALUES DISCUSSED BELOW.
IZZI
//PREV DISCUSSION...
331 AM CDT
ONCE AGAIN TODAY THE PRIMARY FORECAST CHALLENGE IS THE HEAT AND
RESULTANT HEADLINE DECISIONS...WITH A LESSER CONCERN ABOUT
CONVECTIVE POTENTIAL THE NEXT COUPLE OF DAYS.
BEFORE JUMPING INTO FORECAST WANTED TO DO A QUICK REFRESHER FOR WHAT
OUR HEAT ADVISORY AND WARNING CRITERIA IS. FIRST...EVERYWHERE THE
HEAT ADVISORY CRITERIA IS MAXIMUM HEAT INDICES AT OR ABOVE 105
DEGREES. THE HEAT WARNING CRITERIA IS MUCH MORE COMPLEX.
FIRST...OUTSIDE OF COOK COUNTY THE CRITERIA IS AT LEAST 48 HOURS
WITH MAX HEAT INDICES 110F+ WITH MIN HEAT INDICES OF 75 EACH
NIGHT...OR AN EXCESSIVE HEAT WARNING CAN BE ISSUED FOR 4 CONSECUTIVE
DAYS OF MAX HEAT INDICES 105F+ AND MIN HEAT INDICES 75F+. FOR COOK
COUNTY THERE ARE 3 POSSIBLE TRIGGERS FOR A HEAT WARNING. 1) 3 DAYS
OF MAX HEAT INDEX 100F+ WITH 85% SUNSHINE 2 OF THE DAYS OR NIGHT
TIME HEAT INDICES 80F+ OR 2) 2 DAYS OF MAX HEAT INDEX 105F+ OR 3) 1
DAY OF MAX HEAT INDEX 110F+. WANTED TO SPELL OUT THE CRITERIA SINCE
ITS NOT STRAIGHT FORWARD AND SINCE HEADLINE DECISIONS WERE A BIG
FOCUS OF THIS MORNING`S FORECAST.
AFTER CLOUDS AND CONVECTIVE OUTFLOW HELD TEMPS DOWN A BIT
TUESDAY...CONFIDENCE IS HIGHER TODAY THAT TEMPS WILL CRACK THE
CENTURY MARK IN MANY AREAS. ALREADY SEEING 20M 500MB HEIGHT RISES AT
ILX/DVN WITH MODEL FORECASTING HEIGHT RISES OF ANOTHER 20M OR SO
DURING THE NEXT 24 HOURS...INDICATIVE OF A STRENGTHENING UPPER LEVEL
RIDGE. UNLIKE YESTERDAY...THE THREAT OF CLOUD COVER AND CONVECTIVE
OUTFLOW MUCKING THINGS UP APPEARS LOWER. IN ADDITION...WRF-NAM AND
ECMWF 850MB AND 925MB TEMPS STRONGLY SUPPORT TEMPS CLIMBING INTO THE
99-104 RANGE THIS AFTERNOON...WHILE THE GFS REMAINS ALMOST OBLIVIOUS
AS TO WHAT IS GOING ON NOW LET ALONE WHAT MAY HAPPEN. THURSDAY LOOKS
TO BE A COUPLE OF DEGREES WARMER STILL WITH 925MB TEMPS PROGGED TO
WARM 1-2C AND 500MB HEIGHTS TO INCREASE A BIT MORE SETTING THE STAGE
FOR WHAT COULD BE THE HOTTEST AMBIENT AIR TEMPERATURES SINCE THE
1995 KILLER HEAT WAVE AND POSSIBLY EVEN FLIRTING WITH CHICAGO`S ALL
TIME RECORD HIGH OF 105F. IT DOES APPEAR AS THOUGH WEAK LAKE BREEZE
COULD DEVELOP LATE THIS AFTERNOON AND AGAIN THURSDAY LATE AFTERNOON
PROVIDING A BIT OF RELIEF CLOSE TO THE LAKE...BUT THE RELIEF SHOULD
BE SHORT LIVED WITH LAND BREEZE SENDING EVENING TEMPS CLIMBING. IN
FACT...NIGHTTIME LOWS IN THE CITY WILL LIKELY BE IN THE LOW TO MID
80S WITH THE MAJORITY OF THE NIGHT EXPERIENCING HEAT INDICES IN THE
90S (STILL 94 HEAT INDEX DOWNTOWN AT 220AM THIS MORNING).
THE BIGGER QUESTION MARK REVOLVES AROUND DEW POINTS AND HOW MUCH
PERSPIRING CORN CAN COMPENSATE FOR WHAT LOOKS TO BE DEEP AFTERNOON
MIXING. ADMITTEDLY...OUR SKILL AT DEW POINT FORECASTING IS NOT ALL
THAT HIGH WITH MEAN ABSOLUTE ERRORS OF 3-4F FOR 24 HOUR DEW POINT
FORECASTS...WHICH LEAVES OPEN A GOOD 6-8F SIZED RANGE OF POSSIBILITY
FOR AFTERNOON DEW POINTS WHICH HAS MAJOR IMPLICATIONS ON HEAT
INDICES. BASED ON CURRENT DEW POINT FORECASTS HAVE AFTERNOON HEAT
INDICES GENERALLY PEAKING BETWEEN 105-110F ACROSS THE AREA WITH A
FEW OF THE TYPICALLY HOTTER SPOTS GETTING A BIT ABOVE 110F. ITS
WORTH NOTING A 3-4F ERROR IN DEW POINTS WOULD CORRESPOND TO ABOUT A
5F ERROR IN FORE CASTED HEAT INDICES.
CONSIDERING EVERYTHING DISCUSSED IN DEPTH ABOVE...HAVE OPTED TO
CONTINUE WITH A HEAT ADVISORY FOR THE MAJORITY OF THE CWA AS HEAT
INDICES FELL SHORT OF THE 105F ADVISORY THRESHOLD THE PAST 2 DAYS
MAKING IT IMPOSSIBLE TO REACH THE 4 DAY CRITERIA FOR A HEAT WARNING.
IF DEW POINTS STAY UP MORE THAN FORECAST AND HEAT INDICES GET ABOVE
110F THIS AFTERNOON THEN DAY SHIFT MAY NEED TO CONSIDER UPGRADING TO
AN EXCESSIVE HEAT WARNING FOR THURSDAY AND/OR FRIDAY...BUT GIVEN LOW
CONFIDENCE IN THAT SCENARIO THINK AN ADVISORY IS THE BEST COURSE OF
ACTION FOR NOW. FOR COOK COUNTY AND THE CITY OF CHICAGO WHERE
WARNING CRITERIA IS LOWER DUE TO URBAN HEAT ISLAND AND POPULATION
DENSITY/SOCIOECONOMIC CONCERNS WILL BE UPGRADING TO AN EXCESSIVE HEAT
WARNING THROUGH FRIDAY AS WE WILL LIKELY MEET 2 AND 3 DAY CRITERIA
AND COULD EVEN MEET THE 1 DAY WARNING CRITERIA. WHILE NOT UPGRADING
TO A WARNING FOR MOST OF THE AREA DOES LEAVE US AS AN ISLAND
SURROUNDED BY WARNINGS...IT IS VERY POSSIBLE THAT DEW POINTS COULD
MIX OUT AND WE NOT EVEN REACH ADVISORY CRITERIA THIS AFTERNOON LET
ALONE WARNING CRITERIA. ALSO...AN ADVISORY OUTLYING AREAS AND
WARNING FOR COOK COUNTY WILL FURTHER HIGHLIGHT THAT CONDITIONS WILL
BE CONSIDERABLY MORE SEVERE IN THE CITY OF CHICAGO DUE TO THE URBAN
HEAT ISLAND. NOT ONLY WILL DAYTIME TEMPS AND HEAT INDICES TO BE A
FEW DEGREES HIGHER BUT NIGHTTIME HEAT INDICES WILL BE NEARLY 20F
HIGHER ADDING TO THE CUMULATIVE EFFECTS AND DANGER OF THE HEAT WAVE.
FORECAST CONFIDENCE DIMINISHES HEADING INTO FRIDAY AS NUMERICAL
GUIDANCE HAS BEEN TRENDING FASTER WITH WEAK COLD FRONTAL PASSAGE
THAT WILL LIKELY BE SIGNIFICANTLY AUGMENTED BY THE LAKE. ECMWF
REMAINS THE SLOWEST WITH MUCH OF THE AFTERNOON SPENT IN THE WARM
SECTOR WHILE GFS/GEM/WRF-NAM ARE FASTER WITH THE LAKE ENHANCED FROPA
WHICH WOULD RESULT IN COOLER HIGHS...ESPECIALLY NEAR THE LAKE. TOOK
A COMPROMISE APPROACH FOR NOW WITH FROPA STARTING NEAR UGN AROUND
18Z BEFORE SPREADING SOUTH AND WEST FARTHER INLAND. WHILE
TEMPERATURES MAY END UP A FEW DEGREES COOLER ON FRIDAY...DEW POINT
POOLING MAY OFFSET ANY SLIGHT LOWERING OF TEMPS AND RESULT IN HEAT
INDICES EVEN HIGHER THAN THURSDAY OR FRIDAY. TEMP/HEAT INDEX
FORECAST FOR FRIDAY IS GOING TO HINGE HEAVILY ON FROPA TIMING...ANY
SPEEDING UP OF FROPA COULD RESULT IN TEMPS BEING COOLER AND POSSIBLY
AN EARLIER ENDING TO THE HEAT HEADLINES.
REGARDING THUNDERSTORM CHANCES...THERE REMAINS A VERY SMALL CHANCE
OF A THUNDERSTORM BLOWING UP ON THE LAKE BREEZE CONVERGENCE ZONE
LATER THIS AFTERNOON AS BOUNDARY LAYER HEATS UP AND ERASES
CONVECTIVE INHIBITION. RISING UPPER LEVEL HEIGHT AND IMPLIED
SUBSIDENCE CERTAINLY ARE NOT PLUSES FOR THE T-STORM POTENTIAL AND
THINK CHANCES MAY EVEN BE A BIT LOWER THAN 20%...HOWEVER...GIVEN THE
VERY STRONG INSTABILITY (ML CAPES LIKELY OVER 5000 J/KG) AND 0-8KM
BULK SHEAR VALUES NEARING 40KT THE CONDITIONAL SEVERE POTENTIAL IS
VERY HIGH CONTINGENT ON A STORM DEVELOPING. GIVEN THIS FELT IT WAS
BEST TO KEEP 20 POPS GOING 21-03Z. STILL A SMALL THREAT OF A STORM
GOING UP ON LAKE BREEZE THURSDAY AFTERNOON AS WELL...BUT WITH UPPER
HEIGHTS RISING FURTHER AND NO APPARENT TRIGGER...PLUS WEAKER DEEP
LAYER SHEAR/CONDITIONAL SEVERE THREAT HAVE OPTED TO KEEP FORECAST
DRY FOR NOW...BUT THIS WILL NEED TO BE RE-ACCESSED IN SUBSEQUENT
FORECASTS.
INITIALLY EXPECTING FROPA FRIDAY TO BE DRY AS FRONT SHOULD BE
SHALLOW AND UPPER HEIGHTS VERY HIGH...BUT WITH TIME THE UPPER RIDGE
WILL GET BEAT DOWN OVER THE WEEKEND WITH GRADUALLY
INCREASING...THOUGH STILL RATHER LOW...CHANCES FOR SHOWERS AND
THUNDERSTORMS AS BOUNDARY HANGS UP IN THE AREA. MAJORITY OF THE
WEEKEND SHOULD END UP DRY...HOWEVER IT COULD RAIN AT ANY TIME WHICH
NECESSITATES CARRYING POPS EACH PERIOD UNFORTUNATELY. MUCH MORE
SEASONABLE TEMPS AND COMFORTABLE HUMIDITY LEVELS ARE EXPECTED BY
LATE IN THE WEEKEND INTO NEXT WEEK. ANY AREA THAT DOES NOT PICK UP
SIGNIFICANT RAINFALL THIS WEEKEND WILL BE UNLIKELY TO SEE ANY
DROUGHT RELIEF NEXT WEEK AS ALL CURRENT INDICATIONS IN MEDIUM RANGE
GUIDANCE SUGGESTS WE WILL BE AN ANOTHER DRY PATTERN WITH LITTLE HOPE
FOR APPRECIABLE PRECIP UNTIL AT LEAST THE MIDDLE OF JULY.
IZZI
&&
.CLIMATE...
520 AM CDT
CHICAGO ROCKFORD
WED 102 80 101 77
1911 1921 1911 1977
THU 102 82 100 77
1911 1911 1911 1911
FRI 99 80 102 73
1988 1977 1936 1948
THE ALL TIME RECORD HIGH FOR CHICAGO IS 105 SET BACK ON JULY 24
1934...AND FOR ROCKFORD IS 112 SET ON JULY 14 1936.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* NONE.
JEE
//DISCUSSION...UPDATED 18Z...
A LARGE RIDGE EXTENDS ACROSS THE REGION WITH LIGHT W TO SW WINDS
THIS AFTERNOON. MIXING HAS BEEN SLOW THUS FAR TODAY...BUT GUSTS
HAVE DEVELOPED AT ORD AND MDW. BASED ON OBS AND CU
DEVELOPMENT...KEPT WIND GUSTS CONFINED TO ORD AND MDW...BUT MAY
SEE A FEW SPORADIC GUSTS AT GYY. LATEST SATELLITE IMAGERY SHOWS CU
IS DEVELOPING OVER EXTREME NE IL AND NW IN. MORE INTENSE CU
DEVELOPMENT CAN BE FOUND EAST OF VPZ AND IN SOUTHERN IROQUOIS AND
FORD COUNTIES. EXPECTING FEW TO SCT CU TO DEVELOP PRIMARILY OVER
THE EASTERN TERMINALS. CU BASES MAY BE LOWER THAN INDICATED...IN
THE 050-070 RANGE...BUT VFR EITHER WAY.
EXPECTING A LAKE BREEZE TO DEVELOP IMMEDIATELY ALONG THE LAKESHORE
AROUND 00Z AND REMAIN MORE OR LESS RIGHT ALONG THE LAKE SHORE.
WHILE THE LAKE BREEZE WILL NOT AFFECT ORD/MDW WINDS...MAY SEE
ISOLATED CONVECTION FORM ALONG IT. THE LATEST RUC ANALYSIS
INDICATES VERY LITTLE CIN AND OVER 3000 J/KG OF CAPE ALONG THE
LAKESHORE. IN THIS VERY UNSTABLE ENVIRONMENT...ANY FORCING FEATURE
SUCH AS THE LAKE BREEZE COULD LEAD TO A THUNDERSTORM OR TWO.
STEERING FLOW FOR THE STORMS IS NORTHWEST...THEREFORE GOING WITH A
DRY FORECAST FOR ORD. HOWEVER...IF THE LAKE BREEZE PUSHES FARTHER
INLAND THAN EXPECTED...TS MAY FORM NEAR ORD/MDW.
WINDS AND CU DIMINISH AND WINDS BECOME SW TONIGHT. A SIMILAR
SITUATION IS EXPECTED TOMORROW WITH WEST WINDS...GUSTS DEVELOPING
IN THE LATE MORNING...AND SCT VFR CU DEVELOPMENT.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN CIG TRENDS...MEDIUM CONFIDENCE IN CIG
HEIGHTS...CU MAY BE MORE 050-070.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
* THURSDAY NIGHT...VFR.
* FRIDAY...VFR. POSSIBLE LAKE BREEZE IN THE AFTERNOON.
* FRIDAY NIGHT THROUGH MONDAY...VFR. SLIGHT CHANCE OF TSRA.
* TUESDAY...VFR.
&&
.MARINE...
306 AM...A WEAK COLD FRONT WILL MOVE SOUTH ACROSS LAKE MICHIGAN
TODAY AND WASH OUT AS IT REACHES THE SOUTH/CENTRAL PORTION OF THE
LAKE...MKE/MKG REGION. WHILE WINDS WILL TURN NORTHERLY...SPEEDS
WILL BE FAIRLY LIGHT. AS STRONG LOW PRESSURE MOVES ACROSS CANADA
OVER THE NEXT FEW DAYS...THE GRADIENT WILL RETURN SOUTHERLY WINDS
ACROSS THE LAKE UNTIL FRIDAY MORNING...WHEN A TRAILING COLD FRONT
FROM THIS LOW MOVES SOUTH ACROSS THE LAKE. WITH HIGH PRESSURE
BUILDING ACROSS THE MIDWEST/UPPER LAKES BEHIND THIS FRONT...
APPEARS THERE WILL BE A PROLONGED PERIOD OF NORTHERLY WINDS WITH
SPEEDS IN THE 10-20 KT RANGE...ESPECIALLY ON THE SOUTH END OF THE
LAKE. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...EXCESSIVE HEAT WARNING...ILZ014 UNTIL 6 PM FRIDAY.
HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-ILZ032-
ILZ033-ILZ039 UNTIL 10 PM FRIDAY.
IN...HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 10 PM
FRIDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1109 AM CDT WED JUL 4 2012
.DISCUSSION...
1038 AM CDT
UPDATE FOR REST OF TODAY...
ONLY MINIMAL TWEAKS TO OFFICIAL FORECAST GRID SET MADE BASED ON
NEW GUIDANCE COMING IN. THIS RESULTS IN LITTLE OR NO EFFECT ON
DERIVED TEXT PRODUCTS. SO...CONTINUED VERY HOT AND HUMID.
QUESTIONABLE IF LAKE BREEZE DEVELOPS AND MAKE IT TO THE SHORE THIS
AFTERNOON. LATEST GUIDANCE KEEPS THE LOW LEVEL WINDS OUT OF THE
WSW-W UP AROUND 10 KT THROUGH 00Z WHICH WOULD LIKELY KEEP THE LAKE
BREEZE FOR MAKING AN APPEARANCE. CURRENTLY FORECAST DOES NOT HAVE
IT AT THE SHORE TIL AROUND 23Z SO EVEN IF DOES MAKE ANY PROGRESS
ASHORE IT WILL NOT HAVE ANY AFFECT ON MAX TEMPS DUE TO LATE IN
DAY TIMING.
AN SLIM CHANCE OF A THUNDERSTORM OR TWO DOES STILL EXIST DURING
THE LATE AFTERNOON THROUGH MID EVENING ACROSS NE IL AND NW IND AS
THIS AXIS OF MAX INSTABILITY WILL EXTEND SE OUT OF WI. BESIDES
POSSIBILITY OF A LAKE BREEZE BOUNDARY CLOSE TO THE SHORE WILL NOT
BE ANY SURFACE FEATURES TO ACT AS A FOCUS LOW LEVEL CONVERGENCE
AND FORCED UVV. ALSO DO NOT SEE ANYTHING UPSTREAM IN MODELS OR
SATELLITE LOOPS TO PROVIDE MID -UPPER LEVEL SUPPORT.
THERE IS A SHORT WAVE THAT GENERATED A FEW THUNDERSTORMS AROUND
MSP DURING THE EARLY MORNING CURRENTLY TURNING FROM ESE TO SE
ACROSS SOUTHERN WI. THIS DISTURBANCE IS EXPECTED TO BE E OF NE IL
BY EARLY AFTERNOON AND E OF NW IND BY MID AFTERNOON. DO NOT SEE
ENOUGH TO COMPLETELY PULL THE SLIGHT CHANCE POPS CURRENTLY IN THE
FORECAST FOR LATE AFTERNOON THROUGH MID EVENING ACROSS THE NE
QUARTER OF THE FA SO WILL LET RIDE.
TRS
//PREV DISCUSSION...
356 AM CDT
GOING TO CALL A QUICK AUDIBLE BEFORE SENDING OUT ZFP/PUBLISHING
GRIDS...
MID/HIGH CLOUDINESS CONTINUES TO EXPAND OVER WESTERN WISCONSIN AND
SE MINNESOTA. THE 06Z WRF-NAM AND RAP SEEM TO HAVE A GOOD HANDLE
ON THIS MOISTURE. BASED ON LATEST SATELLITE TRENDS AND THIS MODEL
GUIDANCE HAVE OPTED TO INCREASE SKY COVER IN THE GRIDS THROUGH
EARLY AFTERNOON AND ALSO LOWERED TEMPS A FEW DEGREES FROM THE
VALUES DISCUSSED BELOW.
IZZI
//PREV DISCUSSION...
331 AM CDT
ONCE AGAIN TODAY THE PRIMARY FORECAST CHALLENGE IS THE HEAT AND
RESULTANT HEADLINE DECISIONS...WITH A LESSER CONCERN ABOUT
CONVECTIVE POTENTIAL THE NEXT COUPLE OF DAYS.
BEFORE JUMPING INTO FORECAST WANTED TO DO A QUICK REFRESHER FOR WHAT
OUR HEAT ADVISORY AND WARNING CRITERIA IS. FIRST...EVERYWHERE THE
HEAT ADVISORY CRITERIA IS MAXIMUM HEAT INDICES AT OR ABOVE 105
DEGREES. THE HEAT WARNING CRITERIA IS MUCH MORE COMPLEX.
FIRST...OUTSIDE OF COOK COUNTY THE CRITERIA IS AT LEAST 48 HOURS
WITH MAX HEAT INDICES 110F+ WITH MIN HEAT INDICES OF 75 EACH
NIGHT...OR AN EXCESSIVE HEAT WARNING CAN BE ISSUED FOR 4 CONSECUTIVE
DAYS OF MAX HEAT INDICES 105F+ AND MIN HEAT INDICES 75F+. FOR COOK
COUNTY THERE ARE 3 POSSIBLE TRIGGERS FOR A HEAT WARNING. 1) 3 DAYS
OF MAX HEAT INDEX 100F+ WITH 85% SUNSHINE 2 OF THE DAYS OR NIGHT
TIME HEAT INDICES 80F+ OR 2) 2 DAYS OF MAX HEAT INDEX 105F+ OR 3) 1
DAY OF MAX HEAT INDEX 110F+. WANTED TO SPELL OUT THE CRITERIA SINCE
ITS NOT STRAIGHT FORWARD AND SINCE HEADLINE DECISIONS WERE A BIG
FOCUS OF THIS MORNING`S FORECAST.
AFTER CLOUDS AND CONVECTIVE OUTFLOW HELD TEMPS DOWN A BIT
TUESDAY...CONFIDENCE IS HIGHER TODAY THAT TEMPS WILL CRACK THE
CENTURY MARK IN MANY AREAS. ALREADY SEEING 20M 500MB HEIGHT RISES AT
ILX/DVN WITH MODEL FORECASTING HEIGHT RISES OF ANOTHER 20M OR SO
DURING THE NEXT 24 HOURS...INDICATIVE OF A STRENGTHENING UPPER LEVEL
RIDGE. UNLIKE YESTERDAY...THE THREAT OF CLOUD COVER AND CONVECTIVE
OUTFLOW MUCKING THINGS UP APPEARS LOWER. IN ADDITION...WRF-NAM AND
ECMWF 850MB AND 925MB TEMPS STRONGLY SUPPORT TEMPS CLIMBING INTO THE
99-104 RANGE THIS AFTERNOON...WHILE THE GFS REMAINS ALMOST OBLIVIOUS
AS TO WHAT IS GOING ON NOW LET ALONE WHAT MAY HAPPEN. THURSDAY LOOKS
TO BE A COUPLE OF DEGREES WARMER STILL WITH 925MB TEMPS PROGGED TO
WARM 1-2C AND 500MB HEIGHTS TO INCREASE A BIT MORE SETTING THE STAGE
FOR WHAT COULD BE THE HOTTEST AMBIENT AIR TEMPERATURES SINCE THE
1995 KILLER HEAT WAVE AND POSSIBLY EVEN FLIRTING WITH CHICAGO`S ALL
TIME RECORD HIGH OF 105F. IT DOES APPEAR AS THOUGH WEAK LAKE BREEZE
COULD DEVELOP LATE THIS AFTERNOON AND AGAIN THURSDAY LATE AFTERNOON
PROVIDING A BIT OF RELIEF CLOSE TO THE LAKE...BUT THE RELIEF SHOULD
BE SHORT LIVED WITH LAND BREEZE SENDING EVENING TEMPS CLIMBING. IN
FACT...NIGHTTIME LOWS IN THE CITY WILL LIKELY BE IN THE LOW TO MID
80S WITH THE MAJORITY OF THE NIGHT EXPERIENCING HEAT INDICES IN THE
90S (STILL 94 HEAT INDEX DOWNTOWN AT 220AM THIS MORNING).
THE BIGGER QUESTION MARK REVOLVES AROUND DEW POINTS AND HOW MUCH
PERSPIRING CORN CAN COMPENSATE FOR WHAT LOOKS TO BE DEEP AFTERNOON
MIXING. ADMITTEDLY...OUR SKILL AT DEW POINT FORECASTING IS NOT ALL
THAT HIGH WITH MEAN ABSOLUTE ERRORS OF 3-4F FOR 24 HOUR DEW POINT
FORECASTS...WHICH LEAVES OPEN A GOOD 6-8F SIZED RANGE OF POSSIBILITY
FOR AFTERNOON DEW POINTS WHICH HAS MAJOR IMPLICATIONS ON HEAT
INDICES. BASED ON CURRENT DEW POINT FORECASTS HAVE AFTERNOON HEAT
INDICES GENERALLY PEAKING BETWEEN 105-110F ACROSS THE AREA WITH A
FEW OF THE TYPICALLY HOTTER SPOTS GETTING A BIT ABOVE 110F. ITS
WORTH NOTING A 3-4F ERROR IN DEW POINTS WOULD CORRESPOND TO ABOUT A
5F ERROR IN FORE CASTED HEAT INDICES.
CONSIDERING EVERYTHING DISCUSSED IN DEPTH ABOVE...HAVE OPTED TO
CONTINUE WITH A HEAT ADVISORY FOR THE MAJORITY OF THE CWA AS HEAT
INDICES FELL SHORT OF THE 105F ADVISORY THRESHOLD THE PAST 2 DAYS
MAKING IT IMPOSSIBLE TO REACH THE 4 DAY CRITERIA FOR A HEAT WARNING.
IF DEW POINTS STAY UP MORE THAN FORECAST AND HEAT INDICES GET ABOVE
110F THIS AFTERNOON THEN DAY SHIFT MAY NEED TO CONSIDER UPGRADING TO
AN EXCESSIVE HEAT WARNING FOR THURSDAY AND/OR FRIDAY...BUT GIVEN LOW
CONFIDENCE IN THAT SCENARIO THINK AN ADVISORY IS THE BEST COURSE OF
ACTION FOR NOW. FOR COOK COUNTY AND THE CITY OF CHICAGO WHERE
WARNING CRITERIA IS LOWER DUE TO URBAN HEAT ISLAND AND POPULATION
DENSITY/SOCIOECONOMIC CONCERNS WILL BE UPGRADING TO AN EXCESSIVE HEAT
WARNING THROUGH FRIDAY AS WE WILL LIKELY MEET 2 AND 3 DAY CRITERIA
AND COULD EVEN MEET THE 1 DAY WARNING CRITERIA. WHILE NOT UPGRADING
TO A WARNING FOR MOST OF THE AREA DOES LEAVE US AS AN ISLAND
SURROUNDED BY WARNINGS...IT IS VERY POSSIBLE THAT DEW POINTS COULD
MIX OUT AND WE NOT EVEN REACH ADVISORY CRITERIA THIS AFTERNOON LET
ALONE WARNING CRITERIA. ALSO...AN ADVISORY OUTLYING AREAS AND
WARNING FOR COOK COUNTY WILL FURTHER HIGHLIGHT THAT CONDITIONS WILL
BE CONSIDERABLY MORE SEVERE IN THE CITY OF CHICAGO DUE TO THE URBAN
HEAT ISLAND. NOT ONLY WILL DAYTIME TEMPS AND HEAT INDICES TO BE A
FEW DEGREES HIGHER BUT NIGHTTIME HEAT INDICES WILL BE NEARLY 20F
HIGHER ADDING TO THE CUMULATIVE EFFECTS AND DANGER OF THE HEAT WAVE.
FORECAST CONFIDENCE DIMINISHES HEADING INTO FRIDAY AS NUMERICAL
GUIDANCE HAS BEEN TRENDING FASTER WITH WEAK COLD FRONTAL PASSAGE
THAT WILL LIKELY BE SIGNIFICANTLY AUGMENTED BY THE LAKE. ECMWF
REMAINS THE SLOWEST WITH MUCH OF THE AFTERNOON SPENT IN THE WARM
SECTOR WHILE GFS/GEM/WRF-NAM ARE FASTER WITH THE LAKE ENHANCED FROPA
WHICH WOULD RESULT IN COOLER HIGHS...ESPECIALLY NEAR THE LAKE. TOOK
A COMPROMISE APPROACH FOR NOW WITH FROPA STARTING NEAR UGN AROUND
18Z BEFORE SPREADING SOUTH AND WEST FARTHER INLAND. WHILE
TEMPERATURES MAY END UP A FEW DEGREES COOLER ON FRIDAY...DEW POINT
POOLING MAY OFFSET ANY SLIGHT LOWERING OF TEMPS AND RESULT IN HEAT
INDICES EVEN HIGHER THAN THURSDAY OR FRIDAY. TEMP/HEAT INDEX
FORECAST FOR FRIDAY IS GOING TO HINGE HEAVILY ON FROPA TIMING...ANY
SPEEDING UP OF FROPA COULD RESULT IN TEMPS BEING COOLER AND POSSIBLY
AN EARLIER ENDING TO THE HEAT HEADLINES.
REGARDING THUNDERSTORM CHANCES...THERE REMAINS A VERY SMALL CHANCE
OF A THUNDERSTORM BLOWING UP ON THE LAKE BREEZE CONVERGENCE ZONE
LATER THIS AFTERNOON AS BOUNDARY LAYER HEATS UP AND ERASES
CONVECTIVE INHIBITION. RISING UPPER LEVEL HEIGHT AND IMPLIED
SUBSIDENCE CERTAINLY ARE NOT PLUSES FOR THE T-STORM POTENTIAL AND
THINK CHANCES MAY EVEN BE A BIT LOWER THAN 20%...HOWEVER...GIVEN THE
VERY STRONG INSTABILITY (ML CAPES LIKELY OVER 5000 J/KG) AND 0-8KM
BULK SHEAR VALUES NEARING 40KT THE CONDITIONAL SEVERE POTENTIAL IS
VERY HIGH CONTINGENT ON A STORM DEVELOPING. GIVEN THIS FELT IT WAS
BEST TO KEEP 20 POPS GOING 21-03Z. STILL A SMALL THREAT OF A STORM
GOING UP ON LAKE BREEZE THURSDAY AFTERNOON AS WELL...BUT WITH UPPER
HEIGHTS RISING FURTHER AND NO APPARENT TRIGGER...PLUS WEAKER DEEP
LAYER SHEAR/CONDITIONAL SEVERE THREAT HAVE OPTED TO KEEP FORECAST
DRY FOR NOW...BUT THIS WILL NEED TO BE RE-ACCESSED IN SUBSEQUENT
FORECASTS.
INITIALLY EXPECTING FROPA FRIDAY TO BE DRY AS FRONT SHOULD BE
SHALLOW AND UPPER HEIGHTS VERY HIGH...BUT WITH TIME THE UPPER RIDGE
WILL GET BEAT DOWN OVER THE WEEKEND WITH GRADUALLY
INCREASING...THOUGH STILL RATHER LOW...CHANCES FOR SHOWERS AND
THUNDERSTORMS AS BOUNDARY HANGS UP IN THE AREA. MAJORITY OF THE
WEEKEND SHOULD END UP DRY...HOWEVER IT COULD RAIN AT ANY TIME WHICH
NECESSITATES CARRYING POPS EACH PERIOD UNFORTUNATELY. MUCH MORE
SEASONABLE TEMPS AND COMFORTABLE HUMIDITY LEVELS ARE EXPECTED BY
LATE IN THE WEEKEND INTO NEXT WEEK. ANY AREA THAT DOES NOT PICK UP
SIGNIFICANT RAINFALL THIS WEEKEND WILL BE UNLIKELY TO SEE ANY
DROUGHT RELIEF NEXT WEEK AS ALL CURRENT INDICATIONS IN MEDIUM RANGE
GUIDANCE SUGGESTS WE WILL BE AN ANOTHER DRY PATTERN WITH LITTLE HOPE
FOR APPRECIABLE PRECIP UNTIL AT LEAST THE MIDDLE OF JULY.
IZZI
&&
.CLIMATE...
520 AM CDT
CHICAGO ROCKFORD
WED 102 80 101 77
1911 1921 1911 1977
THU 102 82 100 77
1911 1911 1911 1911
FRI 99 80 102 73
1988 1977 1936 1948
THE ALL TIME RECORD HIGH FOR CHICAGO IS 105 SET BACK ON JULY 24
1934...AND FOR ROCKFORD IS 112 SET ON JULY 14 1936.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* NONE.
JEE
//DISCUSSION...UPDATED 12Z...
WEST SOUTHWEST WINDS WILL CONTINUE THROUGH THE PERIOD. WITH LOW
LEVEL MIXING...EXPECT SPEEDS 9-12KTS TODAY...DIMINISHING TO AROUND
5 KT OR LESS THIS EVENING. WHILE THE GRADIENT WEAKENS ENOUGH THAT
A LAKE BREEZE MAY FORM LATE THIS AFTERNOON...THE LOW LEVEL WINDS
ARE EXPECTED TO REMAIN STRONG ENOUGH TO PREVENT A LAKE BREEZE FROM
MOVING TOO FAR INLAND...PERHAPS TURNING WINDS NORTHERLY AT GYY.
THERE REMAINS A SMALL CHANCE...10-15 PERCENT...THAT IF A LAKE
BREEZE FORMS...IT MAY AID ISOLATED THUNDERSTORM DEVELOPMENT.
CONFIDENCE REMAINS FAR TOO LOW FOR ANY MENTION IN THIS FORECAST
BUT WILL NEED TO BE MONITORED THROUGH THE DAY.
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE WITH LAKE BREEZE REMAINING EAST OF ORD/MDW.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
* THURSDAY NIGHT...VFR.
* FRIDAY...VFR. POSSIBLE LAKE BREEZE IN THE AFTERNOON.
* FRIDAY NIGHT THROUGH MONDAY...VFR. SLIGHT CHANCE OF TSRA.
* TUESDAY...VFR.
&&
.MARINE...
306 AM...A WEAK COLD FRONT WILL MOVE SOUTH ACROSS LAKE MICHIGAN
TODAY AND WASH OUT AS IT REACHES THE SOUTH/CENTRAL PORTION OF THE
LAKE...MKE/MKG REGION. WHILE WINDS WILL TURN NORTHERLY...SPEEDS
WILL BE FAIRLY LIGHT. AS STRONG LOW PRESSURE MOVES ACROSS CANADA
OVER THE NEXT FEW DAYS...THE GRADIENT WILL RETURN SOUTHERLY WINDS
ACROSS THE LAKE UNTIL FRIDAY MORNING...WHEN A TRAILING COLD FRONT
FROM THIS LOW MOVES SOUTH ACROSS THE LAKE. WITH HIGH PRESSURE
BUILDING ACROSS THE MIDWEST/UPPER LAKES BEHIND THIS FRONT...
APPEARS THERE WILL BE A PROLONGED PERIOD OF NORTHERLY WINDS WITH
SPEEDS IN THE 10-20 KT RANGE...ESPECIALLY ON THE SOUTH END OF THE
LAKE. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...EXCESSIVE HEAT WARNING...ILZ014 UNTIL 6 PM FRIDAY.
HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-ILZ032-
ILZ033-ILZ039 UNTIL 10 PM FRIDAY.
IN...HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 10 PM
FRIDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1040 AM CDT WED JUL 4 2012
.DISCUSSION...
1038 AM CDT
UPDATE FOR REST OF TODAY...
ONLY MINIMAL TWEAKS TO OFFICIAL FORECAST GRID SET MADE BASED ON
NEW GUIDANCE COMING IN. THIS RESULTS IN LITTLE OR NO EFFECT ON
DERIVED TEXT PRODUCTS. SO...CONTINUED VERY HOT AND HUMID.
QUESTIONABLE IF LAKE BREEZE DEVELOPS AND MAKE IT TO THE SHORE THIS
AFTERNOON. LATEST GUIDANCE KEEPS THE LOW LEVEL WINDS OUT OF THE
WSW-W UP AROUND 10 KT THROUGH 00Z WHICH WOULD LIKELY KEEP THE LAKE
BREEZE FOR MAKING AN APPEARANCE. CURRENTLY FORECAST DOES NOT HAVE
IT AT THE SHORE TIL AROUND 23Z SO EVEN IF DOES MAKE ANY PROGRESS
ASHORE IT WILL NOT HAVE ANY AFFECT ON MAX TEMPS DUE TO LATE IN
DAY TIMING.
AN SLIM CHANCE OF A THUNDERSTORM OR TWO DOES STILL EXIST DURING
THE LATE AFTERNOON THROUGH MID EVENING ACROSS NE IL AND NW IND AS
THIS AXIS OF MAX INSTABILITY WILL EXTEND SE OUT OF WI. BESIDES
POSSIBILITY OF A LAKE BREEZE BOUNDARY CLOSE TO THE SHORE WILL NOT
BE ANY SURFACE FEATURES TO ACT AS A FOCUS LOW LEVEL CONVERGENCE
AND FORCED UVV. ALSO DO NOT SEE ANYTHING UPSTREAM IN MODELS OR
SATELLITE LOOPS TO PROVIDE MID -UPPER LEVEL SUPPORT.
THERE IS A SHORT WAVE THAT GENERATED A FEW THUNDERSTORMS AROUND
MSP DURING THE EARLY MORNING CURRENTLY TURNING FROM ESE TO SE
ACROSS SOUTHERN WI. THIS DISTURBANCE IS EXPECTED TO BE E OF NE IL
BY EARLY AFTERNOON AND E OF NW IND BY MID AFTERNOON. DO NOT SEE
ENOUGH TO COMPLETELY PULL THE SLIGHT CHANCE POPS CURRENTLY IN THE
FORECAST FOR LATE AFTERNOON THROUGH MID EVENING ACROSS THE NE
QUARTER OF THE FA SO WILL LET RIDE.
TRS
&&
.PREV DISCUSSION...
356 AM CDT
GOING TO CALL A QUICK AUDIBLE BEFORE SENDING OUT ZFP/PUBLISHING
GRIDS...
MID/HIGH CLOUDINESS CONTINUES TO EXPAND OVER WESTERN WISCONSIN AND
SE MINNESOTA. THE 06Z WRF-NAM AND RAP SEEM TO HAVE A GOOD HANDLE
ON THIS MOISTURE. BASED ON LATEST SATELLITE TRENDS AND THIS MODEL
GUIDANCE HAVE OPTED TO INCREASE SKY COVER IN THE GRIDS THROUGH
EARLY AFTERNOON AND ALSO LOWERED TEMPS A FEW DEGREES FROM THE
VALUES DISCUSSED BELOW.
IZZI
//PREV DISCUSSION...
331 AM CDT
ONCE AGAIN TODAY THE PRIMARY FORECAST CHALLENGE IS THE HEAT AND
RESULTANT HEADLINE DECISIONS...WITH A LESSER CONCERN ABOUT
CONVECTIVE POTENTIAL THE NEXT COUPLE OF DAYS.
BEFORE JUMPING INTO FORECAST WANTED TO DO A QUICK REFRESHER FOR WHAT
OUR HEAT ADVISORY AND WARNING CRITERIA IS. FIRST...EVERYWHERE THE
HEAT ADVISORY CRITERIA IS MAXIMUM HEAT INDICES AT OR ABOVE 105
DEGREES. THE HEAT WARNING CRITERIA IS MUCH MORE COMPLEX.
FIRST...OUTSIDE OF COOK COUNTY THE CRITERIA IS AT LEAST 48 HOURS
WITH MAX HEAT INDICES 110F+ WITH MIN HEAT INDICES OF 75 EACH
NIGHT...OR AN EXCESSIVE HEAT WARNING CAN BE ISSUED FOR 4 CONSECUTIVE
DAYS OF MAX HEAT INDICES 105F+ AND MIN HEAT INDICES 75F+. FOR COOK
COUNTY THERE ARE 3 POSSIBLE TRIGGERS FOR A HEAT WARNING. 1) 3 DAYS
OF MAX HEAT INDEX 100F+ WITH 85% SUNSHINE 2 OF THE DAYS OR NIGHT
TIME HEAT INDICES 80F+ OR 2) 2 DAYS OF MAX HEAT INDEX 105F+ OR 3) 1
DAY OF MAX HEAT INDEX 110F+. WANTED TO SPELL OUT THE CRITERIA SINCE
ITS NOT STRAIGHT FORWARD AND SINCE HEADLINE DECISIONS WERE A BIG
FOCUS OF THIS MORNING`S FORECAST.
AFTER CLOUDS AND CONVECTIVE OUTFLOW HELD TEMPS DOWN A BIT
TUESDAY...CONFIDENCE IS HIGHER TODAY THAT TEMPS WILL CRACK THE
CENTURY MARK IN MANY AREAS. ALREADY SEEING 20M 500MB HEIGHT RISES AT
ILX/DVN WITH MODEL FORECASTING HEIGHT RISES OF ANOTHER 20M OR SO
DURING THE NEXT 24 HOURS...INDICATIVE OF A STRENGTHENING UPPER LEVEL
RIDGE. UNLIKE YESTERDAY...THE THREAT OF CLOUD COVER AND CONVECTIVE
OUTFLOW MUCKING THINGS UP APPEARS LOWER. IN ADDITION...WRF-NAM AND
ECMWF 850MB AND 925MB TEMPS STRONGLY SUPPORT TEMPS CLIMBING INTO THE
99-104 RANGE THIS AFTERNOON...WHILE THE GFS REMAINS ALMOST OBLIVIOUS
AS TO WHAT IS GOING ON NOW LET ALONE WHAT MAY HAPPEN. THURSDAY LOOKS
TO BE A COUPLE OF DEGREES WARMER STILL WITH 925MB TEMPS PROGGED TO
WARM 1-2C AND 500MB HEIGHTS TO INCREASE A BIT MORE SETTING THE STAGE
FOR WHAT COULD BE THE HOTTEST AMBIENT AIR TEMPERATURES SINCE THE
1995 KILLER HEAT WAVE AND POSSIBLY EVEN FLIRTING WITH CHICAGO`S ALL
TIME RECORD HIGH OF 105F. IT DOES APPEAR AS THOUGH WEAK LAKE BREEZE
COULD DEVELOP LATE THIS AFTERNOON AND AGAIN THURSDAY LATE AFTERNOON
PROVIDING A BIT OF RELIEF CLOSE TO THE LAKE...BUT THE RELIEF SHOULD
BE SHORT LIVED WITH LAND BREEZE SENDING EVENING TEMPS CLIMBING. IN
FACT...NIGHTTIME LOWS IN THE CITY WILL LIKELY BE IN THE LOW TO MID
80S WITH THE MAJORITY OF THE NIGHT EXPERIENCING HEAT INDICES IN THE
90S (STILL 94 HEAT INDEX DOWNTOWN AT 220AM THIS MORNING).
THE BIGGER QUESTION MARK REVOLVES AROUND DEW POINTS AND HOW MUCH
PERSPIRING CORN CAN COMPENSATE FOR WHAT LOOKS TO BE DEEP AFTERNOON
MIXING. ADMITTEDLY...OUR SKILL AT DEW POINT FORECASTING IS NOT ALL
THAT HIGH WITH MEAN ABSOLUTE ERRORS OF 3-4F FOR 24 HOUR DEW POINT
FORECASTS...WHICH LEAVES OPEN A GOOD 6-8F SIZED RANGE OF POSSIBILITY
FOR AFTERNOON DEW POINTS WHICH HAS MAJOR IMPLICATIONS ON HEAT
INDICES. BASED ON CURRENT DEW POINT FORECASTS HAVE AFTERNOON HEAT
INDICES GENERALLY PEAKING BETWEEN 105-110F ACROSS THE AREA WITH A
FEW OF THE TYPICALLY HOTTER SPOTS GETTING A BIT ABOVE 110F. ITS
WORTH NOTING A 3-4F ERROR IN DEW POINTS WOULD CORRESPOND TO ABOUT A
5F ERROR IN FORE CASTED HEAT INDICES.
CONSIDERING EVERYTHING DISCUSSED IN DEPTH ABOVE...HAVE OPTED TO
CONTINUE WITH A HEAT ADVISORY FOR THE MAJORITY OF THE CWA AS HEAT
INDICES FELL SHORT OF THE 105F ADVISORY THRESHOLD THE PAST 2 DAYS
MAKING IT IMPOSSIBLE TO REACH THE 4 DAY CRITERIA FOR A HEAT WARNING.
IF DEW POINTS STAY UP MORE THAN FORECAST AND HEAT INDICES GET ABOVE
110F THIS AFTERNOON THEN DAY SHIFT MAY NEED TO CONSIDER UPGRADING TO
AN EXCESSIVE HEAT WARNING FOR THURSDAY AND/OR FRIDAY...BUT GIVEN LOW
CONFIDENCE IN THAT SCENARIO THINK AN ADVISORY IS THE BEST COURSE OF
ACTION FOR NOW. FOR COOK COUNTY AND THE CITY OF CHICAGO WHERE
WARNING CRITERIA IS LOWER DUE TO URBAN HEAT ISLAND AND POPULATION
DENSITY/SOCIOECONOMIC CONCERNS WILL BE UPGRADING TO AN EXCESSIVE HEAT
WARNING THROUGH FRIDAY AS WE WILL LIKELY MEET 2 AND 3 DAY CRITERIA
AND COULD EVEN MEET THE 1 DAY WARNING CRITERIA. WHILE NOT UPGRADING
TO A WARNING FOR MOST OF THE AREA DOES LEAVE US AS AN ISLAND
SURROUNDED BY WARNINGS...IT IS VERY POSSIBLE THAT DEW POINTS COULD
MIX OUT AND WE NOT EVEN REACH ADVISORY CRITERIA THIS AFTERNOON LET
ALONE WARNING CRITERIA. ALSO...AN ADVISORY OUTLYING AREAS AND
WARNING FOR COOK COUNTY WILL FURTHER HIGHLIGHT THAT CONDITIONS WILL
BE CONSIDERABLY MORE SEVERE IN THE CITY OF CHICAGO DUE TO THE URBAN
HEAT ISLAND. NOT ONLY WILL DAYTIME TEMPS AND HEAT INDICES TO BE A
FEW DEGREES HIGHER BUT NIGHTTIME HEAT INDICES WILL BE NEARLY 20F
HIGHER ADDING TO THE CUMULATIVE EFFECTS AND DANGER OF THE HEAT WAVE.
FORECAST CONFIDENCE DIMINISHES HEADING INTO FRIDAY AS NUMERICAL
GUIDANCE HAS BEEN TRENDING FASTER WITH WEAK COLD FRONTAL PASSAGE
THAT WILL LIKELY BE SIGNIFICANTLY AUGMENTED BY THE LAKE. ECMWF
REMAINS THE SLOWEST WITH MUCH OF THE AFTERNOON SPENT IN THE WARM
SECTOR WHILE GFS/GEM/WRF-NAM ARE FASTER WITH THE LAKE ENHANCED FROPA
WHICH WOULD RESULT IN COOLER HIGHS...ESPECIALLY NEAR THE LAKE. TOOK
A COMPROMISE APPROACH FOR NOW WITH FROPA STARTING NEAR UGN AROUND
18Z BEFORE SPREADING SOUTH AND WEST FARTHER INLAND. WHILE
TEMPERATURES MAY END UP A FEW DEGREES COOLER ON FRIDAY...DEW POINT
POOLING MAY OFFSET ANY SLIGHT LOWERING OF TEMPS AND RESULT IN HEAT
INDICES EVEN HIGHER THAN THURSDAY OR FRIDAY. TEMP/HEAT INDEX
FORECAST FOR FRIDAY IS GOING TO HINGE HEAVILY ON FROPA TIMING...ANY
SPEEDING UP OF FROPA COULD RESULT IN TEMPS BEING COOLER AND POSSIBLY
AN EARLIER ENDING TO THE HEAT HEADLINES.
REGARDING THUNDERSTORM CHANCES...THERE REMAINS A VERY SMALL CHANCE
OF A THUNDERSTORM BLOWING UP ON THE LAKE BREEZE CONVERGENCE ZONE
LATER THIS AFTERNOON AS BOUNDARY LAYER HEATS UP AND ERASES
CONVECTIVE INHIBITION. RISING UPPER LEVEL HEIGHT AND IMPLIED
SUBSIDENCE CERTAINLY ARE NOT PLUSES FOR THE T-STORM POTENTIAL AND
THINK CHANCES MAY EVEN BE A BIT LOWER THAN 20%...HOWEVER...GIVEN THE
VERY STRONG INSTABILITY (ML CAPES LIKELY OVER 5000 J/KG) AND 0-8KM
BULK SHEAR VALUES NEARING 40KT THE CONDITIONAL SEVERE POTENTIAL IS
VERY HIGH CONTINGENT ON A STORM DEVELOPING. GIVEN THIS FELT IT WAS
BEST TO KEEP 20 POPS GOING 21-03Z. STILL A SMALL THREAT OF A STORM
GOING UP ON LAKE BREEZE THURSDAY AFTERNOON AS WELL...BUT WITH UPPER
HEIGHTS RISING FURTHER AND NO APPARENT TRIGGER...PLUS WEAKER DEEP
LAYER SHEAR/CONDITIONAL SEVERE THREAT HAVE OPTED TO KEEP FORECAST
DRY FOR NOW...BUT THIS WILL NEED TO BE RE-ACCESSED IN SUBSEQUENT
FORECASTS.
INITIALLY EXPECTING FROPA FRIDAY TO BE DRY AS FRONT SHOULD BE
SHALLOW AND UPPER HEIGHTS VERY HIGH...BUT WITH TIME THE UPPER RIDGE
WILL GET BEAT DOWN OVER THE WEEKEND WITH GRADUALLY
INCREASING...THOUGH STILL RATHER LOW...CHANCES FOR SHOWERS AND
THUNDERSTORMS AS BOUNDARY HANGS UP IN THE AREA. MAJORITY OF THE
WEEKEND SHOULD END UP DRY...HOWEVER IT COULD RAIN AT ANY TIME WHICH
NECESSITATES CARRYING POPS EACH PERIOD UNFORTUNATELY. MUCH MORE
SEASONABLE TEMPS AND COMFORTABLE HUMIDITY LEVELS ARE EXPECTED BY
LATE IN THE WEEKEND INTO NEXT WEEK. ANY AREA THAT DOES NOT PICK UP
SIGNIFICANT RAINFALL THIS WEEKEND WILL BE UNLIKELY TO SEE ANY
DROUGHT RELIEF NEXT WEEK AS ALL CURRENT INDICATIONS IN MEDIUM RANGE
GUIDANCE SUGGESTS WE WILL BE AN ANOTHER DRY PATTERN WITH LITTLE HOPE
FOR APPRECIABLE PRECIP UNTIL AT LEAST THE MIDDLE OF JULY.
IZZI
&&
.CLIMATE...
520 AM CDT
CHICAGO ROCKFORD
WED 102 80 101 77
1911 1921 1911 1977
THU 102 82 100 77
1911 1911 1911 1911
FRI 99 80 102 73
1988 1977 1936 1948
THE ALL TIME RECORD HIGH FOR CHICAGO IS 105 SET BACK ON JULY 24
1934...AND FOR ROCKFORD IS 112 SET ON JULY 14 1936.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* NONE.
JEE
//DISCUSSION...UPDATED 12Z...
WEST SOUTHWEST WINDS WILL CONTINUE THROUGH THE PERIOD. WITH LOW
LEVEL MIXING...EXPECT SPEEDS 9-12KTS TODAY...DIMINISHING TO AROUND
5 KT OR LESS THIS EVENING. WHILE THE GRADIENT WEAKENS ENOUGH THAT
A LAKE BREEZE MAY FORM LATE THIS AFTERNOON...THE LOW LEVEL WINDS
ARE EXPECTED TO REMAIN STRONG ENOUGH TO PREVENT A LAKE BREEZE FROM
MOVING TOO FAR INLAND...PERHAPS TURNING WINDS NORTHERLY AT GYY.
THERE REMAINS A SMALL CHANCE...10-15 PERCENT...THAT IF A LAKE
BREEZE FORMS...IT MAY AID ISOLATED THUNDERSTORM DEVELOPMENT.
CONFIDENCE REMAINS FAR TOO LOW FOR ANY MENTION IN THIS FORECAST
BUT WILL NEED TO BE MONITORED THROUGH THE DAY.
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM CONFIDENCE WITH LAKE BREEZE REMAINING EAST OF ORD/MDW.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
* THURSDAY NIGHT...VFR.
* FRIDAY...VFR. POSSIBLE LAKE BREEZE IN THE AFTERNOON.
* FRIDAY NIGHT THROUGH MONDAY...VFR. SLIGHT CHANCE OF TSRA.
* TUESDAY...VFR.
&&
.MARINE...
306 AM...A WEAK COLD FRONT WILL MOVE SOUTH ACROSS LAKE MICHIGAN
TODAY AND WASH OUT AS IT REACHES THE SOUTH/CENTRAL PORTION OF THE
LAKE...MKE/MKG REGION. WHILE WINDS WILL TURN NORTHERLY...SPEEDS
WILL BE FAIRLY LIGHT. AS STRONG LOW PRESSURE MOVES ACROSS CANADA
OVER THE NEXT FEW DAYS...THE GRADIENT WILL RETURN SOUTHERLY WINDS
ACROSS THE LAKE UNTIL FRIDAY MORNING...WHEN A TRAILING COLD FRONT
FROM THIS LOW MOVES SOUTH ACROSS THE LAKE. WITH HIGH PRESSURE
BUILDING ACROSS THE MIDWEST/UPPER LAKES BEHIND THIS FRONT...
APPEARS THERE WILL BE A PROLONGED PERIOD OF NORTHERLY WINDS WITH
SPEEDS IN THE 10-20 KT RANGE...ESPECIALLY ON THE SOUTH END OF THE
LAKE. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...EXCESSIVE HEAT WARNING...ILZ014 UNTIL 6 PM FRIDAY.
HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-ILZ032-
ILZ033-ILZ039 UNTIL 10 PM FRIDAY.
IN...HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 10 PM
FRIDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
846 AM CDT WED JUL 4 2012
.DISCUSSION...
356 AM CDT
GOING TO CALL A QUICK AUDIBLE BEFORE SENDING OUT ZFP/PUBLISHING
GRIDS...
MID/HIGH CLOUDINESS CONTINUES TO EXPAND OVER WESTERN WISCONSIN AND
SE MINNESOTA. THE 06Z WRF-NAM AND RAP SEEM TO HAVE A GOOD HANDLE
ON THIS MOISTURE. BASED ON LATEST SATELLITE TRENDS AND THIS MODEL
GUIDANCE HAVE OPTED TO INCREASE SKY COVER IN THE GRIDS THROUGH
EARLY AFTERNOON AND ALSO LOWERED TEMPS A FEW DEGREES FROM THE
VALUES DISCUSSED BELOW.
IZZI
//PREV DISCUSSION...
331 AM CDT
ONCE AGAIN TODAY THE PRIMARY FORECAST CHALLENGE IS THE HEAT AND
RESULTANT HEADLINE DECISIONS...WITH A LESSER CONCERN ABOUT
CONVECTIVE POTENTIAL THE NEXT COUPLE OF DAYS.
BEFORE JUMPING INTO FORECAST WANTED TO DO A QUICK REFRESHER FOR WHAT
OUR HEAT ADVISORY AND WARNING CRITERIA IS. FIRST...EVERYWHERE THE
HEAT ADVISORY CRITERIA IS MAXIMUM HEAT INDICES AT OR ABOVE 105
DEGREES. THE HEAT WARNING CRITERIA IS MUCH MORE COMPLEX.
FIRST...OUTSIDE OF COOK COUNTY THE CRITERIA IS AT LEAST 48 HOURS
WITH MAX HEAT INDICES 110F+ WITH MIN HEAT INDICES OF 75 EACH
NIGHT...OR AN EXCESSIVE HEAT WARNING CAN BE ISSUED FOR 4 CONSECUTIVE
DAYS OF MAX HEAT INDICES 105F+ AND MIN HEAT INDICES 75F+. FOR COOK
COUNTY THERE ARE 3 POSSIBLE TRIGGERS FOR A HEAT WARNING. 1) 3 DAYS
OF MAX HEAT INDEX 100F+ WITH 85% SUNSHINE 2 OF THE DAYS OR NIGHT
TIME HEAT INDICES 80F+ OR 2) 2 DAYS OF MAX HEAT INDEX 105F+ OR 3) 1
DAY OF MAX HEAT INDEX 110F+. WANTED TO SPELL OUT THE CRITERIA SINCE
ITS NOT STRAIGHT FORWARD AND SINCE HEADLINE DECISIONS WERE A BIG
FOCUS OF THIS MORNING`S FORECAST.
AFTER CLOUDS AND CONVECTIVE OUTFLOW HELD TEMPS DOWN A BIT
TUESDAY...CONFIDENCE IS HIGHER TODAY THAT TEMPS WILL CRACK THE
CENTURY MARK IN MANY AREAS. ALREADY SEEING 20M 500MB HEIGHT RISES AT
ILX/DVN WITH MODEL FORECASTING HEIGHT RISES OF ANOTHER 20M OR SO
DURING THE NEXT 24 HOURS...INDICATIVE OF A STRENGTHENING UPPER LEVEL
RIDGE. UNLIKE YESTERDAY...THE THREAT OF CLOUD COVER AND CONVECTIVE
OUTFLOW MUCKING THINGS UP APPEARS LOWER. IN ADDITION...WRF-NAM AND
ECMWF 850MB AND 925MB TEMPS STRONGLY SUPPORT TEMPS CLIMBING INTO THE
99-104 RANGE THIS AFTERNOON...WHILE THE GFS REMAINS ALMOST OBLIVIOUS
AS TO WHAT IS GOING ON NOW LET ALONE WHAT MAY HAPPEN. THURSDAY LOOKS
TO BE A COUPLE OF DEGREES WARMER STILL WITH 925MB TEMPS PROGGED TO
WARM 1-2C AND 500MB HEIGHTS TO INCREASE A BIT MORE SETTING THE STAGE
FOR WHAT COULD BE THE HOTTEST AMBIENT AIR TEMPERATURES SINCE THE
1995 KILLER HEAT WAVE AND POSSIBLY EVEN FLIRTING WITH CHICAGO`S ALL
TIME RECORD HIGH OF 105F. IT DOES APPEAR AS THOUGH WEAK LAKE BREEZE
COULD DEVELOP LATE THIS AFTERNOON AND AGAIN THURSDAY LATE AFTERNOON
PROVIDING A BIT OF RELIEF CLOSE TO THE LAKE...BUT THE RELIEF SHOULD
BE SHORT LIVED WITH LAND BREEZE SENDING EVENING TEMPS CLIMBING. IN
FACT...NIGHTTIME LOWS IN THE CITY WILL LIKELY BE IN THE LOW TO MID
80S WITH THE MAJORITY OF THE NIGHT EXPERIENCING HEAT INDICES IN THE
90S (STILL 94 HEAT INDEX DOWNTOWN AT 220AM THIS MORNING).
THE BIGGER QUESTION MARK REVOLVES AROUND DEWPOINTS AND HOW MUCH
PERSPIRING CORN CAN COMPENSATE FOR WHAT LOOKS TO BE DEEP AFTERNOON
MIXING. ADMITTEDLY...OUR SKILL AT DEWPOINT FORECASTING IS NOT ALL
THAT HIGH WITH MEAN ABSOLUTE ERRORS OF 3-4F FOR 24 HOUR DEWPOINT
FORECASTS...WHICH LEAVES OPEN A GOOD 6-8F SIZED RANGE OF POSSIBILITY
FOR AFTERNOON DEWPOINTS WHICH HAS MAJOR IMPLICATIONS ON HEAT
INDICES. BASED ON CURRENT DEWPOINT FORECASTS HAVE AFTERNOON HEAT
INDICES GENERALLY PEAKING BETWEEN 105-110F ACROSS THE AREA WITH A
FEW OF THE TYPICALLY HOTTER SPOTS GETTING A BIT ABOVE 110F. ITS
WORTH NOTING A 3-4F ERROR IN DEWPOINTS WOULD CORRESPOND TO ABOUT A
5F ERROR IN FORECASTED HEAT INDICES.
CONSIDERING EVERYTHING DISCUSSED IN DEPTH ABOVE...HAVE OPTED TO
CONTINUE WITH A HEAT ADVISORY FOR THE MAJORITY OF THE CWA AS HEAT
INDICES FELL SHORT OF THE 105F ADVISORY THRESHOLD THE PAST 2 DAYS
MAKING IT IMPOSSIBLE TO REACH THE 4 DAY CRITERIA FOR A HEAT WARNING.
IF DEWPOINTS STAY UP MORE THAN FORECAST AND HEAT INDICES GET ABOVE
110F THIS AFTERNOON THEN DAY SHIFT MAY NEED TO CONSIDER UPGRADING TO
AN EXCESSIVE HEAT WARNING FOR THURSDAY AND/OR FRIDAY...BUT GIVEN LOW
CONFIDENCE IN THAT SCENARIO THINK AN ADVISORY IS THE BEST COURSE OF
ACTION FOR NOW. FOR COOK COUNTY AND THE CITY OF CHICAGO WHERE
WARNING CRITERIA IS LOWER DUE TO URBAN HEAT ISLAND AND POPULATION
DENSITY/SOCIOECONOMIC CONCERNS WILL BE UPGRADING TO AN EXCESSIVE HEAT
WARNING THROUGH FRIDAY AS WE WILL LIKELY MEET 2 AND 3 DAY CRITERIA
AND COULD EVEN MEET THE 1 DAY WARNING CRITERIA. WHILE NOT UPGRADING
TO A WARNING FOR MOST OF THE AREA DOES LEAVE US AS AN ISLAND
SURROUNDED BY WARNINGS...IT IS VERY POSSIBLE THAT DEWPOINTS COULD
MIX OUT AND WE NOT EVEN REACH ADVISORY CRITERIA THIS AFTERNOON LET
ALONE WARNING CRITERIA. ALSO...AN ADVISORY OUTLYING AREAS AND
WARNING FOR COOK COUNTY WILL FURTHER HIGHLIGHT THAT CONDITIONS WILL
BE CONSIDERABLY MORE SEVERE IN THE CITY OF CHICAGO DUE TO THE URBAN
HEAT ISLAND. NOT ONLY WILL DAYTIME TEMPS AND HEAT INDICES TO BE A
FEW DEGREES HIGHER BUT NIGHTTIME HEAT INDICES WILL BE NEARLY 20F
HIGHER ADDING TO THE CUMULATIVE EFFECTS AND DANGER OF THE HEAT WAVE.
FORECAST CONFIDENCE DIMINISHES HEADING INTO FRIDAY AS NUMERICAL
GUIDANCE HAS BEEN TRENDING FASTER WITH WEAK COLD FRONTAL PASSAGE
THAT WILL LIKELY BE SIGNIFICANTLY AUGMENTED BY THE LAKE. ECMWF
REMAINS THE SLOWEST WITH MUCH OF THE AFTERNOON SPENT IN THE WARM
SECTOR WHILE GFS/GEM/WRF-NAM ARE FASTER WITH THE LAKE ENHANCED FROPA
WHICH WOULD RESULT IN COOLER HIGHS...ESPECIALLY NEAR THE LAKE. TOOK
A COMPROMISE APPROACH FOR NOW WITH FROPA STARTING NEAR UGN AROUND
18Z BEFORE SPREADING SOUTH AND WEST FARTHER INLAND. WHILE
TEMPERATURES MAY END UP A FEW DEGREES COOLER ON FRIDAY...DEWPOINT
POOLING MAY OFFSET ANY SLIGHT LOWERING OF TEMPS AND RESULT IN HEAT
INDICES EVEN HIGHER THAN THURSDAY OR FRIDAY. TEMP/HEAT INDEX
FORECAST FOR FRIDAY IS GOING TO HINGE HEAVILY ON FROPA TIMING...ANY
SPEEDING UP OF FROPA COULD RESULT IN TEMPS BEING COOLER AND POSSIBLY
AN EARLIER ENDING TO THE HEAT HEADLINES.
REGARDING THUNDERSTORM CHANCES...THERE REMAINS A VERY SMALL CHANCE
OF A THUNDERSTORM BLOWING UP ON THE LAKE BREEZE CONVERGENCE ZONE
LATER THIS AFTERNOON AS BOUNDARY LAYER HEATS UP AND ERASES
CONVECTIVE INHIBITION. RISING UPPER LEVEL HEIGHT AND IMPLIED
SUBSIDENCE CERTAINLY ARE NOT PLUSES FOR THE T-STORM POTENTIAL AND
THINK CHANCES MAY EVEN BE A BIT LOWER THAN 20%...HOWEVER...GIVEN THE
VERY STRONG INSTABILITY (MLCAPES LIKELY OVER 5000 J/KG) AND 0-8KM
BULK SHEAR VALUES NEARING 40KT THE CONDITIONAL SEVERE POTENTIAL IS
VERY HIGH CONTINGENT ON A STORM DEVELOPING. GIVEN THIS FELT IT WAS
BEST TO KEEP 20 POPS GOING 21-03Z. STILL A SMALL THREAT OF A STORM
GOING UP ON LAKE BREEZE THURSDAY AFTERNOON AS WELL...BUT WITH UPPER
HEIGHTS RISING FURTHER AND NO APPARENT TRIGGER...PLUS WEAKER DEEP
LAYER SHEAR/CONDITIONAL SEVERE THREAT HAVE OPTED TO KEEP FORECAST
DRY FOR NOW...BUT THIS WILL NEED TO BE RE-ACCESSED IN SUBSEQUENT
FORECASTS.
INITIALLY EXPECTING FROPA FRIDAY TO BE DRY AS FRONT SHOULD BE
SHALLOW AND UPPER HEIGHTS VERY HIGH...BUT WITH TIME THE UPPER RIDGE
WILL GET BEAT DOWN OVER THE WEEKEND WITH GRADUALLY
INCREASING...THOUGH STILL RATHER LOW...CHANCES FOR SHOWERS AND
THUNDERSTORMS AS BOUNDARY HANGS UP IN THE AREA. MAJORITY OF THE
WEEKEND SHOULD END UP DRY...HOWEVER IT COULD RAIN AT ANY TIME WHICH
NECESSITATES CARRYING POPS EACH PERIOD UNFORTUNATELY. MUCH MORE
SEASONABLE TEMPS AND COMFORTABLE HUMIDITY LEVELS ARE EXPECTED BY
LATE IN THE WEEKEND INTO NEXT WEEK. ANY AREA THAT DOES NOT PICK UP
SIGNIFICANT RAINFALL THIS WEEKEND WILL BE UNLIKELY TO SEE ANY
DROUGHT RELIEF NEXT WEEK AS ALL CURRENT INDICATIONS IN MEDIUM RANGE
GUIDANCE SUGGESTS WE WILL BE AN ANOTHER DRY PATTERN WITH LITTLE HOPE
FOR APPRECIABLE PRECIP UNTIL AT LEAST THE MIDDLE OF JULY.
IZZI
&&
.CLIMATE...
520 AM CDT
CHICAGO ROCKFORD
WED 102 80 101 77
1911 1921 1911 1977
THU 102 82 100 77
1911 1911 1911 1911
FRI 99 80 102 73
1988 1977 1936 1948
THE ALL TIME RECORD HIGH FOR CHICAGO IS 105 SET BACK ON JULY 24
1934...AND FOR ROCKFORD IS 112 SET ON JULY 14 1936.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* NONE.
JEE
//DISCUSSION...UPDATED 12Z...
WEST SOUTHWEST WINDS WILL CONTINUE THROUGH THE PERIOD. WITH LOW
LEVEL MIXING...EXPECT SPEEDS 9-12KTS TODAY...DIMINISHING TO AROUND
5 KT OR LESS THIS EVENING. WHILE THE GRADIENT WEAKENS ENOUGH THAT
A LAKE BREEZE MAY FORM LATE THIS AFTERNOON...THE LOW LEVEL WINDS
ARE EXPECTED TO REMAIN STRONG ENOUGH TO PREVENT A LAKE BREEZE FROM
MOVING TOO FAR INLAND...PERHAPS TURNING WINDS NORTHERLY AT GYY.
THERE REMAINS A SMALL CHANCE...10-15 PERCENT...THAT IF A LAKE
BREEZE FORMS...IT MAY AID ISOLATED THUNDERSTORM DEVELOPMENT.
CONFIDENCE REMAINS FAR TOO LOW FOR ANY MENTION IN THIS FORECAST
BUT WILL NEED TO BE MONITORED THROUGH THE DAY.
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM CONFIDENCE WITH LAKE BREEZE REMAINING EAST OF ORD/MDW.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
* THURSDAY NIGHT...VFR.
* FRIDAY...VFR. POSSIBLE LAKE BREEZE IN THE AFTERNOON.
* FRIDAY NIGHT THROUGH MONDAY...VFR. SLIGHT CHANCE OF TSRA.
* TUESDAY...VFR.
&&
.MARINE...
306 AM...A WEAK COLD FRONT WILL MOVE SOUTH ACROSS LAKE MICHIGAN
TODAY AND WASH OUT AS IT REACHES THE SOUTH/CENTRAL PORTION OF THE
LAKE...MKE/MKG REGION. WHILE WINDS WILL TURN NORTHERLY...SPEEDS
WILL BE FAIRLY LIGHT. AS STRONG LOW PRESSURE MOVES ACROSS CANADA
OVER THE NEXT FEW DAYS...THE GRADIENT WILL RETURN SOUTHERLY WINDS
ACROSS THE LAKE UNTIL FRIDAY MORNING...WHEN A TRAILING COLD FRONT
FROM THIS LOW MOVES SOUTH ACROSS THE LAKE. WITH HIGH PRESSURE
BUILDING ACROSS THE MIDWEST/UPPER LAKES BEHIND THIS FRONT...
APPEARS THERE WILL BE A PROLONGED PERIOD OF NORTHERLY WINDS WITH
SPEEDS IN THE 10-20 KT RANGE...ESPECIALLY ON THE SOUTH END OF THE
LAKE. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...EXCESSIVE HEAT WARNING...ILZ014 UNTIL 6 PM FRIDAY.
HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-ILZ032-
ILZ033-ILZ039 UNTIL 10 PM FRIDAY.
IN...HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 10 PM
FRIDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
629 AM CDT WED JUL 4 2012
.DISCUSSION...
356 AM CDT
GOING TO CALL A QUICK AUDIBLE BEFORE SENDING OUT ZFP/PUBLISHING
GRIDS...
MID/HIGH CLOUDINESS CONTINUES TO EXPAND OVER WESTERN WISCONSIN AND
SE MINNESOTA. THE 06Z WRF-NAM AND RAP SEEM TO HAVE A GOOD HANDLE
ON THIS MOISTURE. BASED ON LATEST SATELLITE TRENDS AND THIS MODEL
GUIDANCE HAVE OPTED TO INCREASE SKY COVER IN THE GRIDS THROUGH
EARLY AFTERNOON AND ALSO LOWERED TEMPS A FEW DEGREES FROM THE
VALUES DISCUSSED BELOW.
IZZI
//PREV DISCUSSION...
331 AM CDT
ONCE AGAIN TODAY THE PRIMARY FORECAST CHALLENGE IS THE HEAT AND
RESULTANT HEADLINE DECISIONS...WITH A LESSER CONCERN ABOUT
CONVECTIVE POTENTIAL THE NEXT COUPLE OF DAYS.
BEFORE JUMPING INTO FORECAST WANTED TO DO A QUICK REFRESHER FOR WHAT
OUR HEAT ADVISORY AND WARNING CRITERIA IS. FIRST...EVERYWHERE THE
HEAT ADVISORY CRITERIA IS MAXIMUM HEAT INDICES AT OR ABOVE 105
DEGREES. THE HEAT WARNING CRITERIA IS MUCH MORE COMPLEX.
FIRST...OUTSIDE OF COOK COUNTY THE CRITERIA IS AT LEAST 48 HOURS
WITH MAX HEAT INDICES 110F+ WITH MIN HEAT INDICES OF 75 EACH
NIGHT...OR AN EXCESSIVE HEAT WARNING CAN BE ISSUED FOR 4 CONSECUTIVE
DAYS OF MAX HEAT INDICES 105F+ AND MIN HEAT INDICES 75F+. FOR COOK
COUNTY THERE ARE 3 POSSIBLE TRIGGERS FOR A HEAT WARNING. 1) 3 DAYS
OF MAX HEAT INDEX 100F+ WITH 85% SUNSHINE 2 OF THE DAYS OR NIGHT
TIME HEAT INDICES 80F+ OR 2) 2 DAYS OF MAX HEAT INDEX 105F+ OR 3) 1
DAY OF MAX HEAT INDEX 110F+. WANTED TO SPELL OUT THE CRITERIA SINCE
ITS NOT STRAIGHT FORWARD AND SINCE HEADLINE DECISIONS WERE A BIG
FOCUS OF THIS MORNING`S FORECAST.
AFTER CLOUDS AND CONVECTIVE OUTFLOW HELD TEMPS DOWN A BIT
TUESDAY...CONFIDENCE IS HIGHER TODAY THAT TEMPS WILL CRACK THE
CENTURY MARK IN MANY AREAS. ALREADY SEEING 20M 500MB HEIGHT RISES AT
ILX/DVN WITH MODEL FORECASTING HEIGHT RISES OF ANOTHER 20M OR SO
DURING THE NEXT 24 HOURS...INDICATIVE OF A STRENGTHENING UPPER LEVEL
RIDGE. UNLIKE YESTERDAY...THE THREAT OF CLOUD COVER AND CONVECTIVE
OUTFLOW MUCKING THINGS UP APPEARS LOWER. IN ADDITION...WRF-NAM AND
ECMWF 850MB AND 925MB TEMPS STRONGLY SUPPORT TEMPS CLIMBING INTO THE
99-104 RANGE THIS AFTERNOON...WHILE THE GFS REMAINS ALMOST OBLIVIOUS
AS TO WHAT IS GOING ON NOW LET ALONE WHAT MAY HAPPEN. THURSDAY LOOKS
TO BE A COUPLE OF DEGREES WARMER STILL WITH 925MB TEMPS PROGGED TO
WARM 1-2C AND 500MB HEIGHTS TO INCREASE A BIT MORE SETTING THE STAGE
FOR WHAT COULD BE THE HOTTEST AMBIENT AIR TEMPERATURES SINCE THE
1995 KILLER HEAT WAVE AND POSSIBLY EVEN FLIRTING WITH CHICAGO`S ALL
TIME RECORD HIGH OF 105F. IT DOES APPEAR AS THOUGH WEAK LAKE BREEZE
COULD DEVELOP LATE THIS AFTERNOON AND AGAIN THURSDAY LATE AFTERNOON
PROVIDING A BIT OF RELIEF CLOSE TO THE LAKE...BUT THE RELIEF SHOULD
BE SHORT LIVED WITH LAND BREEZE SENDING EVENING TEMPS CLIMBING. IN
FACT...NIGHTTIME LOWS IN THE CITY WILL LIKELY BE IN THE LOW TO MID
80S WITH THE MAJORITY OF THE NIGHT EXPERIENCING HEAT INDICES IN THE
90S (STILL 94 HEAT INDEX DOWNTOWN AT 220AM THIS MORNING).
THE BIGGER QUESTION MARK REVOLVES AROUND DEWPOINTS AND HOW MUCH
PERSPIRING CORN CAN COMPENSATE FOR WHAT LOOKS TO BE DEEP AFTERNOON
MIXING. ADMITTEDLY...OUR SKILL AT DEWPOINT FORECASTING IS NOT ALL
THAT HIGH WITH MEAN ABSOLUTE ERRORS OF 3-4F FOR 24 HOUR DEWPOINT
FORECASTS...WHICH LEAVES OPEN A GOOD 6-8F SIZED RANGE OF POSSIBILITY
FOR AFTERNOON DEWPOINTS WHICH HAS MAJOR IMPLICATIONS ON HEAT
INDICES. BASED ON CURRENT DEWPOINT FORECASTS HAVE AFTERNOON HEAT
INDICES GENERALLY PEAKING BETWEEN 105-110F ACROSS THE AREA WITH A
FEW OF THE TYPICALLY HOTTER SPOTS GETTING A BIT ABOVE 110F. ITS
WORTH NOTING A 3-4F ERROR IN DEWPOINTS WOULD CORRESPOND TO ABOUT A
5F ERROR IN FORECASTED HEAT INDICES.
CONSIDERING EVERYTHING DISCUSSED IN DEPTH ABOVE...HAVE OPTED TO
CONTINUE WITH A HEAT ADVISORY FOR THE MAJORITY OF THE CWA AS HEAT
INDICES FELL SHORT OF THE 105F ADVISORY THRESHOLD THE PAST 2 DAYS
MAKING IT IMPOSSIBLE TO REACH THE 4 DAY CRITERIA FOR A HEAT WARNING.
IF DEWPOINTS STAY UP MORE THAN FORECAST AND HEAT INDICES GET ABOVE
110F THIS AFTERNOON THEN DAY SHIFT MAY NEED TO CONSIDER UPGRADING TO
AN EXCESSIVE HEAT WARNING FOR THURSDAY AND/OR FRIDAY...BUT GIVEN LOW
CONFIDENCE IN THAT SCENARIO THINK AN ADVISORY IS THE BEST COURSE OF
ACTION FOR NOW. FOR COOK COUNTY AND THE CITY OF CHICAGO WHERE
WARNING CRITERIA IS LOWER DUE TO URBAN HEAT ISLAND AND POPULATION
DENSITY/SOCIECONOMIC CONCERNS WILL BE UPGRADING TO AN EXCESSIVE HEAT
WARNING THROUGH FRIDAY AS WE WILL LIKELY MEET 2 AND 3 DAY CRITERIA
AND COULD EVEN MEET THE 1 DAY WARNING CRITERIA. WHILE NOT UPGRADING
TO A WARNING FOR MOST OF THE AREA DOES LEAVE US AS AN ISLAND
SURROUNDED BY WARNINGS...IT IS VERY POSSIBLE THAT DEWPOINTS COULD
MIX OUT AND WE NOT EVEN REACH ADVISORY CRITERIA THIS AFTERNOON LET
ALONE WARNING CRITERIA. ALSO...AN ADVISORY OUTLYING AREAS AND
WARNING FOR COOK COUNTY WILL FURTHER HIGHLIGHT THAT CONDITIONS WILL
BE CONSIDERABLY MORE SEVERE IN THE CITY OF CHICAGO DUE TO THE URBAN
HEAT ISLAND. NOT ONLY WILL DAYTIME TEMPS AND HEAT INDICES TO BE A
FEW DEGREES HIGHER BUT NIGHTTIME HEAT INDICES WILL BE NEARLY 20F
HIGHER ADDING TO THE CUMULATIVE EFFECTS AND DANGER OF THE HEAT WAVE.
FORECAST CONFIDENCE DIMINISHES HEADING INTO FRIDAY AS NUMERICAL
GUIDANCE HAS BEEN TRENDING FASTER WITH WEAK COLD FRONTAL PASSAGE
THAT WILL LIKELY BE SIGNIFICANTLY AUGMENTED BY THE LAKE. ECMWF
REMAINS THE SLOWEST WITH MUCH OF THE AFTERNOON SPENT IN THE WARM
SECTOR WHILE GFS/GEM/WRF-NAM ARE FASTER WITH THE LAKE ENHANCED FROPA
WHICH WOULD RESULT IN COOLER HIGHS...ESPECIALLY NEAR THE LAKE. TOOK
A COMPROMISE APPROACH FOR NOW WITH FROPA STARTING NEAR UGN AROUND
18Z BEFORE SPREADING SOUTH AND WEST FARTHER INLAND. WHILE
TEMPERATURES MAY END UP A FEW DEGREES COOLER ON FRIDAY...DEWPOINT
POOLING MAY OFFSET ANY SLIGHT LOWERING OF TEMPS AND RESULT IN HEAT
INDICES EVEN HIGHER THAN THURSDAY OR FRIDAY. TEMP/HEAT INDEX
FORECAST FOR FRIDAY IS GOING TO HINGE HEAVILY ON FROPA TIMING...ANY
SPEEDING UP OF FROPA COULD RESULT IN TEMPS BEING COOLER AND POSSIBLY
AN EARLIER ENDING TO THE HEAT HEADLINES.
REGARDING THUNDERSTORM CHANCES...THERE REMAINS A VERY SMALL CHANCE
OF A THUNDERSTORM BLOWING UP ON THE LAKE BREEZE CONVERGENCE ZONE
LATER THIS AFTERNOON AS BOUNDARY LAYER HEATS UP AND ERASES
CONVECTIVE INHIBITION. RISING UPPER LEVEL HEIGHT AND IMPLIED
SUBSIDENCE CERTAINLY ARE NOT PLUSES FOR THE T-STORM POTENTIAL AND
THINK CHANCES MAY EVEN BE A BIT LOWER THAN 20%...HOWEVER...GIVEN THE
VERY STRONG INSTABILITY (MLCAPES LIKELY OVER 5000 J/KG) AND 0-8KM
BULK SHEAR VALUES NEARING 40KT THE CONDITIONAL SEVERE POTENTIAL IS
VERY HIGH CONTINGENT ON A STORM DEVELOPING. GIVEN THIS FELT IT WAS
BEST TO KEEP 20 POPS GOING 21-03Z. STILL A SMALL THREAT OF A STORM
GOING UP ON LAKE BREEZE THURSDAY AFTERNOON AS WELL...BUT WITH UPPER
HEIGHTS RISING FURTHER AND NO APPARENT TRIGGER...PLUS WEAKER DEEP
LAYER SHEAR/CONDITIONAL SEVERE THREAT HAVE OPTED TO KEEP FORECAST
DRY FOR NOW...BUT THIS WILL NEED TO BE RE-ACCESSED IN SUBSEQUENT
FORECASTS.
INITIALLY EXPECTING FROPA FRIDAY TO BE DRY AS FRONT SHOULD BE
SHALLOW AND UPPER HEIGHTS VERY HIGH...BUT WITH TIME THE UPPER RIDGE
WILL GET BEAT DOWN OVER THE WEEKEND WITH GRADUALLY
INCREASING...THOUGH STILL RATHER LOW...CHANCES FOR SHOWERS AND
THUNDERSTORMS AS BOUNDARY HANGS UP IN THE AREA. MAJORITY OF THE
WEEKEND SHOULD END UP DRY...HOWEVER IT COULD RAIN AT ANY TIME WHICH
NECESSITATES CARRYING POPS EACH PERIOD UNFORTUNATELY. MUCH MORE
SEASONABLE TEMPS AND COMFORTABLE HUMIDITY LEVELS ARE EXPECTED BY
LATE IN THE WEEKEND INTO NEXT WEEK. ANY AREA THAT DOES NOT PICK UP
SIGNIFICANT RAINFALL THIS WEEKEND WILL BE UNLIKELY TO SEE ANY
DROUGHT RELIEF NEXT WEEK AS ALL CURRENT INDICATIONS IN MEDIUM RANGE
GUIDANCE SUGGESTS WE WILL BE AN ANOTHER DRY PATTERN WITH LITTLE HOPE
FOR APPRECIABLE PRECIP UNTIL AT LEAST THE MIDDLE OF JULY.
IZZI
&&
.CLIMATE...
520 AM CDT
CHICAGO ROCKFORD
WED 102 80 101 77
1911 1921 1911 1977
THU 102 82 100 77
1911 1911 1911 1911
FRI 99 80 102 73
1988 1977 1936 1948
THE ALL TIME RECORD HIGH FOR CHICAGO IS 105 SET BACK ON JULY 24
1934...AND FOR ROCKFORD IS 112 SET ON JULY 14 1936.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* NONE. CMS
//DISCUSSION...UPDATED 12Z...
WEST SOUTHWEST WINDS WILL CONTINUE THROUGH THE PERIOD. WITH LOW
LEVEL MIXING...EXPECT SPEEDS 9-12KTS TODAY...DIMINISHING TO AROUND
5 KT OR LESS THIS EVENING. WHILE THE GRADIENT WEAKENS ENOUGH THAT
A LAKE BREEZE MAY FORM LATE THIS AFTERNOON...THE LOW LEVEL WINDS
ARE EXPECTED TO REMAIN STRONG ENOUGH TO PREVENT A LAKE BREEZE FROM
MOVING TOO FAR INLAND...PERHAPS TURNING WINDS NORTHERLY AT GYY.
THERE REMAINS A SMALL CHANCE...10-15 PERCENT...THAT IF A LAKE
BREEZE FORMS...IT MAY AID ISOLATED THUNDERSTORM DEVELOPMENT.
CONFIDENCE REMAINS FAR TOO LOW FOR ANY MENTION IN THIS FORECAST
BUT WILL NEED TO BE MONITORED THROUGH THE DAY.
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* MEDIUM CONFIDENCE REGARDING WIND SPEEDS/DIRECTIONS AND LAKE
BREEZE REMAINING EAST OF ORD/MDW. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
* THURSDAY NIGHT...VFR.
* FRIDAY...VFR. POSSIBLE LAKE BREEZE IN THE AFTERNOON.
* FRIDAY NIGHT THROUGH MONDAY...VFR. SLIGHT CHANCE OF TSRA.
* TUESDAY...VFR.
&&
.MARINE...
306 AM...A WEAK COLD FRONT WILL MOVE SOUTH ACROSS LAKE MICHIGAN
TODAY AND WASH OUT AS IT REACHES THE SOUTH/CENTRAL PORTION OF THE
LAKE...MKE/MKG REGION. WHILE WINDS WILL TURN NORTHERLY...SPEEDS
WILL BE FAIRLY LIGHT. AS STRONG LOW PRESSURE MOVES ACROSS CANADA
OVER THE NEXT FEW DAYS...THE GRADIENT WILL RETURN SOUTHERLY WINDS
ACROSS THE LAKE UNTIL FRIDAY MORNING...WHEN A TRAILING COLD FRONT
FROM THIS LOW MOVES SOUTH ACROSS THE LAKE. WITH HIGH PRESSURE
BUILDING ACROSS THE MIDWEST/UPPER LAKES BEHIND THIS FRONT...
APPEARS THERE WILL BE A PROLONGED PERIOD OF NORTHERLY WINDS WITH
SPEEDS IN THE 10-20 KT RANGE...ESPECIALLY ON THE SOUTH END OF THE
LAKE. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...EXCESSIVE HEAT WARNING...ILZ014 UNTIL 6 PM FRIDAY.
HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-ILZ032-
ILZ033-ILZ039 UNTIL 10 PM FRIDAY.
IN...HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 10 PM
FRIDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
404 AM CDT WED JUL 4 2012
.DISCUSSION...
356 AM CDT
GOING TO CALL A QUICK AUDIBLE BEFORE SENDING OUT ZFP/PUBLISHING
GRIDS...
MID/HIGH CLOUDINESS CONTINUES TO EXPAND OVER WESTERN WISCONSIN AND
SE MINNESOTA. THE 06Z WRF-NAM AND RAP SEEM TO HAVE A GOOD HANDLE
ON THIS MOISTURE. BASED ON LATEST SATELLITE TRENDS AND THIS MODEL
GUIDANCE HAVE OPTED TO INCREASE SKY COVER IN THE GRIDS THROUGH
EARLY AFTERNOON AND ALSO LOWERED TEMPS A FEW DEGREES FROM THE
VALUES DISCUSSED BELOW.
IZZI
//PREV DISCUSSION...
331 AM CDT
ONCE AGAIN TODAY THE PRIMARY FORECAST CHALLENGE IS THE HEAT AND
RESULTANT HEADLINE DECISIONS...WITH A LESSER CONCERN ABOUT
CONVECTIVE POTENTIAL THE NEXT COUPLE OF DAYS.
BEFORE JUMPING INTO FORECAST WANTED TO DO A QUICK REFRESHER FOR WHAT
OUR HEAT ADVISORY AND WARNING CRITERIA IS. FIRST...EVERYWHERE THE
HEAT ADVISORY CRITERIA IS MAXIMUM HEAT INDICES AT OR ABOVE 105
DEGREES. THE HEAT WARNING CRITERIA IS MUCH MORE COMPLEX.
FIRST...OUTSIDE OF COOK COUNTY THE CRITERIA IS AT LEAST 48 HOURS
WITH MAX HEAT INDICES 110F+ WITH MIN HEAT INDICES OF 75 EACH
NIGHT...OR AN EXCESSIVE HEAT WARNING CAN BE ISSUED FOR 4 CONSECUTIVE
DAYS OF MAX HEAT INDICES 105F+ AND MIN HEAT INDICES 75F+. FOR COOK
COUNTY THERE ARE 3 POSSIBLE TRIGGERS FOR A HEAT WARNING. 1) 3 DAYS
OF MAX HEAT INDEX 100F+ WITH 85% SUNSHINE 2 OF THE DAYS OR NIGHT
TIME HEAT INDICES 80F+ OR 2) 2 DAYS OF MAX HEAT INDEX 105F+ OR 3) 1
DAY OF MAX HEAT INDEX 110F+. WANTED TO SPELL OUT THE CRITERIA SINCE
ITS NOT STRAIGHT FORWARD AND SINCE HEADLINE DECISIONS WERE A BIG
FOCUS OF THIS MORNING`S FORECAST.
AFTER CLOUDS AND CONVECTIVE OUTFLOW HELD TEMPS DOWN A BIT
TUESDAY...CONFIDENCE IS HIGHER TODAY THAT TEMPS WILL CRACK THE
CENTURY MARK IN MANY AREAS. ALREADY SEEING 20M 500MB HEIGHT RISES AT
ILX/DVN WITH MODEL FORECASTING HEIGHT RISES OF ANOTHER 20M OR SO
DURING THE NEXT 24 HOURS...INDICATIVE OF A STRENGTHENING UPPER LEVEL
RIDGE. UNLIKE YESTERDAY...THE THREAT OF CLOUD COVER AND CONVECTIVE
OUTFLOW MUCKING THINGS UP APPEARS LOWER. IN ADDITION...WRF-NAM AND
ECMWF 850MB AND 925MB TEMPS STRONGLY SUPPORT TEMPS CLIMBING INTO THE
99-104 RANGE THIS AFTERNOON...WHILE THE GFS REMAINS ALMOST OBLIVIOUS
AS TO WHAT IS GOING ON NOW LET ALONE WHAT MAY HAPPEN. THURSDAY LOOKS
TO BE A COUPLE OF DEGREES WARMER STILL WITH 925MB TEMPS PROGGED TO
WARM 1-2C AND 500MB HEIGHTS TO INCREASE A BIT MORE SETTING THE STAGE
FOR WHAT COULD BE THE HOTTEST AMBIENT AIR TEMPERATURES SINCE THE
1995 KILLER HEAT WAVE AND POSSIBLY EVEN FLIRTING WITH CHICAGO`S ALL
TIME RECORD HIGH OF 105F. IT DOES APPEAR AS THOUGH WEAK LAKE BREEZE
COULD DEVELOP LATE THIS AFTERNOON AND AGAIN THURSDAY LATE AFTERNOON
PROVIDING A BIT OF RELIEF CLOSE TO THE LAKE...BUT THE RELIEF SHOULD
BE SHORT LIVED WITH LAND BREEZE SENDING EVENING TEMPS CLIMBING. IN
FACT...NIGHTTIME LOWS IN THE CITY WILL LIKELY BE IN THE LOW TO MID
80S WITH THE MAJORITY OF THE NIGHT EXPERIENCING HEAT INDICES IN THE
90S (STILL 94 HEAT INDEX DOWNTOWN AT 220AM THIS MORNING).
THE BIGGER QUESTION MARK REVOLVES AROUND DEWPOINTS AND HOW MUCH
PERSPIRING CORN CAN COMPENSATE FOR WHAT LOOKS TO BE DEEP AFTERNOON
MIXING. ADMITTEDLY...OUR SKILL AT DEWPOINT FORECASTING IS NOT ALL
THAT HIGH WITH MEAN ABSOLUTE ERRORS OF 3-4F FOR 24 HOUR DEWPOINT
FORECASTS...WHICH LEAVES OPEN A GOOD 6-8F SIZED RANGE OF POSSIBILITY
FOR AFTERNOON DEWPOINTS WHICH HAS MAJOR IMPLICATIONS ON HEAT
INDICES. BASED ON CURRENT DEWPOINT FORECASTS HAVE AFTERNOON HEAT
INDICES GENERALLY PEAKING BETWEEN 105-110F ACROSS THE AREA WITH A
FEW OF THE TYPICALLY HOTTER SPOTS GETTING A BIT ABOVE 110F. ITS
WORTH NOTING A 3-4F ERROR IN DEWPOINTS WOULD CORRESPOND TO ABOUT A
5F ERROR IN FORECASTED HEAT INDICES.
CONSIDERING EVERYTHING DISCUSSED IN DEPTH ABOVE...HAVE OPTED TO
CONTINUE WITH A HEAT ADVISORY FOR THE MAJORITY OF THE CWA AS HEAT
INDICES FELL SHORT OF THE 105F ADVISORY THRESHOLD THE PAST 2 DAYS
MAKING IT IMPOSSIBLE TO REACH THE 4 DAY CRITERIA FOR A HEAT WARNING.
IF DEWPOINTS STAY UP MORE THAN FORECAST AND HEAT INDICES GET ABOVE
110F THIS AFTERNOON THEN DAY SHIFT MAY NEED TO CONSIDER UPGRADING TO
AN EXCESSIVE HEAT WARNING FOR THURSDAY AND/OR FRIDAY...BUT GIVEN LOW
CONFIDENCE IN THAT SCENARIO THINK AN ADVISORY IS THE BEST COURSE OF
ACTION FOR NOW. FOR COOK COUNTY AND THE CITY OF CHICAGO WHERE
WARNING CRITERIA IS LOWER DUE TO URBAN HEAT ISLAND AND POPULATION
DENSITY/SOCIECONOMIC CONCERNS WILL BE UPGRADING TO AN EXCESSIVE HEAT
WARNING THROUGH FRIDAY AS WE WILL LIKELY MEET 2 AND 3 DAY CRITERIA
AND COULD EVEN MEET THE 1 DAY WARNING CRITERIA. WHILE NOT UPGRADING
TO A WARNING FOR MOST OF THE AREA DOES LEAVE US AS AN ISLAND
SURROUNDED BY WARNINGS...IT IS VERY POSSIBLE THAT DEWPOINTS COULD
MIX OUT AND WE NOT EVEN REACH ADVISORY CRITERIA THIS AFTERNOON LET
ALONE WARNING CRITERIA. ALSO...AN ADVISORY OUTLYING AREAS AND
WARNING FOR COOK COUNTY WILL FURTHER HIGHLIGHT THAT CONDITIONS WILL
BE CONSIDERABLY MORE SEVERE IN THE CITY OF CHICAGO DUE TO THE URBAN
HEAT ISLAND. NOT ONLY WILL DAYTIME TEMPS AND HEAT INDICES TO BE A
FEW DEGREES HIGHER BUT NIGHTTIME HEAT INDICES WILL BE NEARLY 20F
HIGHER ADDING TO THE CUMULATIVE EFFECTS AND DANGER OF THE HEAT WAVE.
FORECAST CONFIDENCE DIMINISHES HEADING INTO FRIDAY AS NUMERICAL
GUIDANCE HAS BEEN TRENDING FASTER WITH WEAK COLD FRONTAL PASSAGE
THAT WILL LIKELY BE SIGNIFICANTLY AUGMENTED BY THE LAKE. ECMWF
REMAINS THE SLOWEST WITH MUCH OF THE AFTERNOON SPENT IN THE WARM
SECTOR WHILE GFS/GEM/WRF-NAM ARE FASTER WITH THE LAKE ENHANCED FROPA
WHICH WOULD RESULT IN COOLER HIGHS...ESPECIALLY NEAR THE LAKE. TOOK
A COMPROMISE APPROACH FOR NOW WITH FROPA STARTING NEAR UGN AROUND
18Z BEFORE SPREADING SOUTH AND WEST FARTHER INLAND. WHILE
TEMPERATURES MAY END UP A FEW DEGREES COOLER ON FRIDAY...DEWPOINT
POOLING MAY OFFSET ANY SLIGHT LOWERING OF TEMPS AND RESULT IN HEAT
INDICES EVEN HIGHER THAN THURSDAY OR FRIDAY. TEMP/HEAT INDEX
FORECAST FOR FRIDAY IS GOING TO HINGE HEAVILY ON FROPA TIMING...ANY
SPEEDING UP OF FROPA COULD RESULT IN TEMPS BEING COOLER AND POSSIBLY
AN EARLIER ENDING TO THE HEAT HEADLINES.
REGARDING THUNDERSTORM CHANCES...THERE REMAINS A VERY SMALL CHANCE
OF A THUNDERSTORM BLOWING UP ON THE LAKE BREEZE CONVERGENCE ZONE
LATER THIS AFTERNOON AS BOUNDARY LAYER HEATS UP AND ERASES
CONVECTIVE INHIBITION. RISING UPPER LEVEL HEIGHT AND IMPLIED
SUBSIDENCE CERTAINLY ARE NOT PLUSES FOR THE T-STORM POTENTIAL AND
THINK CHANCES MAY EVEN BE A BIT LOWER THAN 20%...HOWEVER...GIVEN THE
VERY STRONG INSTABILITY (MLCAPES LIKELY OVER 5000 J/KG) AND 0-8KM
BULK SHEAR VALUES NEARING 40KT THE CONDITIONAL SEVERE POTENTIAL IS
VERY HIGH CONTINGENT ON A STORM DEVELOPING. GIVEN THIS FELT IT WAS
BEST TO KEEP 20 POPS GOING 21-03Z. STILL A SMALL THREAT OF A STORM
GOING UP ON LAKE BREEZE THURSDAY AFTERNOON AS WELL...BUT WITH UPPER
HEIGHTS RISING FURTHER AND NO APPARENT TRIGGER...PLUS WEAKER DEEP
LAYER SHEAR/CONDITIONAL SEVERE THREAT HAVE OPTED TO KEEP FORECAST
DRY FOR NOW...BUT THIS WILL NEED TO BE RE-ACCESSED IN SUBSEQUENT
FORECASTS.
INITIALLY EXPECTING FROPA FRIDAY TO BE DRY AS FRONT SHOULD BE
SHALLOW AND UPPER HEIGHTS VERY HIGH...BUT WITH TIME THE UPPER RIDGE
WILL GET BEAT DOWN OVER THE WEEKEND WITH GRADUALLY
INCREASING...THOUGH STILL RATHER LOW...CHANCES FOR SHOWERS AND
THUNDERSTORMS AS BOUNDARY HANGS UP IN THE AREA. MAJORITY OF THE
WEEKEND SHOULD END UP DRY...HOWEVER IT COULD RAIN AT ANY TIME WHICH
NECESSITATES CARRYING POPS EACH PERIOD UNFORTUNATELY. MUCH MORE
SEASONABLE TEMPS AND COMFORTABLE HUMIDITY LEVELS ARE EXPECTED BY
LATE IN THE WEEKEND INTO NEXT WEEK. ANY AREA THAT DOES NOT PICK UP
SIGNIFICANT RAINFALL THIS WEEKEND WILL BE UNLIKELY TO SEE ANY
DROUGHT RELIEF NEXT WEEK AS ALL CURRENT INDICATIONS IN MEDIUM RANGE
GUIDANCE SUGGESTS WE WILL BE AN ANOTHER DRY PATTERN WITH LITTLE HOPE
FOR APPRECIABLE PRECIP UNTIL AT LEAST THE MIDDLE OF JULY.
IZZI
&&
.CLIMATE...
520 AM CDT
CHICAGO ROCKFORD
WED 102 80 101 77
1911 1921 1911 1977
THU 102 82 100 77
1911 1911 1911 1911
FRI 99 80 102 73
1988 1977 1936 1948
THE ALL TIME RECORD HIGH FOR CHICAGO IS 105 SET BACK ON JULY 24
1934...AND FOR ROCKFORD IS 112 SET ON JULY 14 1936.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* POSSIBLE LAKE BREEZE THIS AFTERNOON...NOT EXPECTED TO REACH
ORD/MDW.
//DISCUSSION...UPDATED 06Z...
SOUTHWEST WINDS AROUND 5KT OR SO OVERNIGHT WILL TURN MORE WESTERLY
LATER THIS MORNING INTO THIS AFTERNOON WITH SPEEDS INCREASING TO
10-12 KTS. THIS SHOULD BE SUFFICIENT TO PREVENT A LAKE BREEZE FROM
MOVING TOO FAR INLAND...BUT THE GRADIENT IS JUST WEAK ENOUGH THAT
A LAKE BREEZE WILL PROBABLY FORM AT THE SHORE BY LATE AFTERNOON
AND COULD POTENTIALLY TURN WINDS NORTHERLY AT GYY. THE LAKE
BREEZE...ASSUMING IT FORMS...COULD POSSIBLY AID ISOLATED TSRA
DEVELOPMENT BUT CONFIDENCE FAR TOO LOW FOR ANY MENTION IN THIS
FORECAST. CMS
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* MEDIUM CONFIDENCE REGARDING WIND SPEEDS/DIRECTIONS AND LAKE
BREEZE REMAINING EAST OF ORD/MDW. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
* THURSDAY...VFR.
* FRIDAY...VFR.
* SATURDAY THROUGH MONDAY...VFR. SLIGHT CHANCE OF TSRA.
KJB
&&
.MARINE...
306 AM...A WEAK COLD FRONT WILL MOVE SOUTH ACROSS LAKE MICHIGAN
TODAY AND WASH OUT AS IT REACHES THE SOUTH/CENTRAL PORTION OF THE
LAKE...MKE/MKG REGION. WHILE WINDS WILL TURN NORTHERLY...SPEEDS
WILL BE FAIRLY LIGHT. AS STRONG LOW PRESSURE MOVES ACROSS CANADA
OVER THE NEXT FEW DAYS...THE GRADIENT WILL RETURN SOUTHERLY WINDS
ACROSS THE LAKE UNTIL FRIDAY MORNING...WHEN A TRAILING COLD FRONT
FROM THIS LOW MOVES SOUTH ACROSS THE LAKE. WITH HIGH PRESSURE
BUILDING ACROSS THE MIDWEST/UPPER LAKES BEHIND THIS FRONT...
APPEARS THERE WILL BE A PROLONGED PERIOD OF NORTHERLY WINDS WITH
SPEEDS IN THE 10-20 KT RANGE...ESPECIALLY ON THE SOUTH END OF THE
LAKE. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...EXCESSIVE HEAT WARNING...ILZ014 UNTIL 6 PM FRIDAY.
HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-ILZ032-
ILZ033-ILZ039 UNTIL 10 PM FRIDAY.
IN...HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 10 PM
FRIDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
356 AM CDT WED JUL 4 2012
.DISCUSSION...
356 AM CDT
GOING TO CALL A QUICK AUDIBLE BEFORE SENDING OUT ZFP/PUBLISHING
GRIDS...
MID/HIGH CLOUDINESS CONTINUES TO EXPAND OVER WESTERN WISCONSIN AND
SE MINNESOTA. THE 06Z WRF-NAM AND RAP SEEM TO HAVE A GOOD HANDLE
ON THIS MOISTURE. BASED ON LATEST SATELLITE TRENDS AND THIS MODEL
GUIDANCE HAVE OPTED TO INCREASE SKY COVER IN THE GRIDS THROUGH
EARLY AFTERNOON AND ALSO LOWERED TEMPS A FEW DEGREES FROM THE
VALUES DISCUSSED BELOW.
IZZI
&&
.PREV DISCUSSION...
331 AM CDT
ONCE AGAIN TODAY THE PRIMARY FORECAST CHALLENGE IS THE HEAT AND
RESULTANT HEADLINE DECISIONS...WITH A LESSER CONCERN ABOUT
CONVECTIVE POTENTIAL THE NEXT COUPLE OF DAYS.
BEFORE JUMPING INTO FORECAST WANTED TO DO A QUICK REFRESHER FOR WHAT
OUR HEAT ADVISORY AND WARNING CRITERIA IS. FIRST...EVERYWHERE THE
HEAT ADVISORY CRITERIA IS MAXIMUM HEAT INDICES AT OR ABOVE 105
DEGREES. THE HEAT WARNING CRITERIA IS MUCH MORE COMPLEX.
FIRST...OUTSIDE OF COOK COUNTY THE CRITERIA IS AT LEAST 48 HOURS
WITH MAX HEAT INDICES 110F+ WITH MIN HEAT INDICES OF 75 EACH
NIGHT...OR AN EXCESSIVE HEAT WARNING CAN BE ISSUED FOR 4 CONSECUTIVE
DAYS OF MAX HEAT INDICES 105F+ AND MIN HEAT INDICES 75F+. FOR COOK
COUNTY THERE ARE 3 POSSIBLE TRIGGERS FOR A HEAT WARNING. 1) 3 DAYS
OF MAX HEAT INDEX 100F+ WITH 85% SUNSHINE 2 OF THE DAYS OR NIGHT
TIME HEAT INDICES 80F+ OR 2) 2 DAYS OF MAX HEAT INDEX 105F+ OR 3) 1
DAY OF MAX HEAT INDEX 110F+. WANTED TO SPELL OUT THE CRITERIA SINCE
ITS NOT STRAIGHT FORWARD AND SINCE HEADLINE DECISIONS WERE A BIG
FOCUS OF THIS MORNING`S FORECAST.
AFTER CLOUDS AND CONVECTIVE OUTFLOW HELD TEMPS DOWN A BIT
TUESDAY...CONFIDENCE IS HIGHER TODAY THAT TEMPS WILL CRACK THE
CENTURY MARK IN MANY AREAS. ALREADY SEEING 20M 500MB HEIGHT RISES AT
ILX/DVN WITH MODEL FORECASTING HEIGHT RISES OF ANOTHER 20M OR SO
DURING THE NEXT 24 HOURS...INDICATIVE OF A STRENGTHENING UPPER LEVEL
RIDGE. UNLIKE YESTERDAY...THE THREAT OF CLOUD COVER AND CONVECTIVE
OUTFLOW MUCKING THINGS UP APPEARS LOWER. IN ADDITION...WRF-NAM AND
ECMWF 850MB AND 925MB TEMPS STRONGLY SUPPORT TEMPS CLIMBING INTO THE
99-104 RANGE THIS AFTERNOON...WHILE THE GFS REMAINS ALMOST OBLIVIOUS
AS TO WHAT IS GOING ON NOW LET ALONE WHAT MAY HAPPEN. THURSDAY LOOKS
TO BE A COUPLE OF DEGREES WARMER STILL WITH 925MB TEMPS PROGGED TO
WARM 1-2C AND 500MB HEIGHTS TO INCREASE A BIT MORE SETTING THE STAGE
FOR WHAT COULD BE THE HOTTEST AMBIENT AIR TEMPERATURES SINCE THE
1995 KILLER HEAT WAVE AND POSSIBLY EVEN FLIRTING WITH CHICAGO`S ALL
TIME RECORD HIGH OF 105F. IT DOES APPEAR AS THOUGH WEAK LAKE BREEZE
COULD DEVELOP LATE THIS AFTERNOON AND AGAIN THURSDAY LATE AFTERNOON
PROVIDING A BIT OF RELIEF CLOSE TO THE LAKE...BUT THE RELIEF SHOULD
BE SHORT LIVED WITH LAND BREEZE SENDING EVENING TEMPS CLIMBING. IN
FACT...NIGHTTIME LOWS IN THE CITY WILL LIKELY BE IN THE LOW TO MID
80S WITH THE MAJORITY OF THE NIGHT EXPERIENCING HEAT INDICES IN THE
90S (STILL 94 HEAT INDEX DOWNTOWN AT 220AM THIS MORNING).
THE BIGGER QUESTION MARK REVOLVES AROUND DEWPOINTS AND HOW MUCH
PERSPIRING CORN CAN COMPENSATE FOR WHAT LOOKS TO BE DEEP AFTERNOON
MIXING. ADMITTEDLY...OUR SKILL AT DEWPOINT FORECASTING IS NOT ALL
THAT HIGH WITH MEAN ABSOLUTE ERRORS OF 3-4F FOR 24 HOUR DEWPOINT
FORECASTS...WHICH LEAVES OPEN A GOOD 6-8F SIZED RANGE OF POSSIBILITY
FOR AFTERNOON DEWPOINTS WHICH HAS MAJOR IMPLICATIONS ON HEAT
INDICES. BASED ON CURRENT DEWPOINT FORECASTS HAVE AFTERNOON HEAT
INDICES GENERALLY PEAKING BETWEEN 105-110F ACROSS THE AREA WITH A
FEW OF THE TYPICALLY HOTTER SPOTS GETTING A BIT ABOVE 110F. ITS
WORTH NOTING A 3-4F ERROR IN DEWPOINTS WOULD CORRESPOND TO ABOUT A
5F ERROR IN FORECASTED HEAT INDICES.
CONSIDERING EVERYTHING DISCUSSED IN DEPTH ABOVE...HAVE OPTED TO
CONTINUE WITH A HEAT ADVISORY FOR THE MAJORITY OF THE CWA AS HEAT
INDICES FELL SHORT OF THE 105F ADVISORY THRESHOLD THE PAST 2 DAYS
MAKING IT IMPOSSIBLE TO REACH THE 4 DAY CRITERIA FOR A HEAT WARNING.
IF DEWPOINTS STAY UP MORE THAN FORECAST AND HEAT INDICES GET ABOVE
110F THIS AFTERNOON THEN DAY SHIFT MAY NEED TO CONSIDER UPGRADING TO
AN EXCESSIVE HEAT WARNING FOR THURSDAY AND/OR FRIDAY...BUT GIVEN LOW
CONFIDENCE IN THAT SCENARIO THINK AN ADVISORY IS THE BEST COURSE OF
ACTION FOR NOW. FOR COOK COUNTY AND THE CITY OF CHICAGO WHERE
WARNING CRITERIA IS LOWER DUE TO URBAN HEAT ISLAND AND POPULATION
DENSITY/SOCIECONOMIC CONCERNS WILL BE UPGRADING TO AN EXCESSIVE HEAT
WARNING THROUGH FRIDAY AS WE WILL LIKELY MEET 2 AND 3 DAY CRITERIA
AND COULD EVEN MEET THE 1 DAY WARNING CRITERIA. WHILE NOT UPGRADING
TO A WARNING FOR MOST OF THE AREA DOES LEAVE US AS AN ISLAND
SURROUNDED BY WARNINGS...IT IS VERY POSSIBLE THAT DEWPOINTS COULD
MIX OUT AND WE NOT EVEN REACH ADVISORY CRITERIA THIS AFTERNOON LET
ALONE WARNING CRITERIA. ALSO...AN ADVISORY OUTLYING AREAS AND
WARNING FOR COOK COUNTY WILL FURTHER HIGHLIGHT THAT CONDITIONS WILL
BE CONSIDERABLY MORE SEVERE IN THE CITY OF CHICAGO DUE TO THE URBAN
HEAT ISLAND. NOT ONLY WILL DAYTIME TEMPS AND HEAT INDICES TO BE A
FEW DEGREES HIGHER BUT NIGHTTIME HEAT INDICES WILL BE NEARLY 20F
HIGHER ADDING TO THE CUMULATIVE EFFECTS AND DANGER OF THE HEAT WAVE.
FORECAST CONFIDENCE DIMINISHES HEADING INTO FRIDAY AS NUMERICAL
GUIDANCE HAS BEEN TRENDING FASTER WITH WEAK COLD FRONTAL PASSAGE
THAT WILL LIKELY BE SIGNIFICANTLY AUGMENTED BY THE LAKE. ECMWF
REMAINS THE SLOWEST WITH MUCH OF THE AFTERNOON SPENT IN THE WARM
SECTOR WHILE GFS/GEM/WRF-NAM ARE FASTER WITH THE LAKE ENHANCED FROPA
WHICH WOULD RESULT IN COOLER HIGHS...ESPECIALLY NEAR THE LAKE. TOOK
A COMPROMISE APPROACH FOR NOW WITH FROPA STARTING NEAR UGN AROUND
18Z BEFORE SPREADING SOUTH AND WEST FARTHER INLAND. WHILE
TEMPERATURES MAY END UP A FEW DEGREES COOLER ON FRIDAY...DEWPOINT
POOLING MAY OFFSET ANY SLIGHT LOWERING OF TEMPS AND RESULT IN HEAT
INDICES EVEN HIGHER THAN THURSDAY OR FRIDAY. TEMP/HEAT INDEX
FORECAST FOR FRIDAY IS GOING TO HINGE HEAVILY ON FROPA TIMING...ANY
SPEEDING UP OF FROPA COULD RESULT IN TEMPS BEING COOLER AND POSSIBLY
AN EARLIER ENDING TO THE HEAT HEADLINES.
REGARDING THUNDERSTORM CHANCES...THERE REMAINS A VERY SMALL CHANCE
OF A THUNDERSTORM BLOWING UP ON THE LAKE BREEZE CONVERGENCE ZONE
LATER THIS AFTERNOON AS BOUNDARY LAYER HEATS UP AND ERASES
CONVECTIVE INHIBITION. RISING UPPER LEVEL HEIGHT AND IMPLIED
SUBSIDENCE CERTAINLY ARE NOT PLUSES FOR THE T-STORM POTENTIAL AND
THINK CHANCES MAY EVEN BE A BIT LOWER THAN 20%...HOWEVER...GIVEN THE
VERY STRONG INSTABILITY (MLCAPES LIKELY OVER 5000 J/KG) AND 0-8KM
BULK SHEAR VALUES NEARING 40KT THE CONDITIONAL SEVERE POTENTIAL IS
VERY HIGH CONTINGENT ON A STORM DEVELOPING. GIVEN THIS FELT IT WAS
BEST TO KEEP 20 POPS GOING 21-03Z. STILL A SMALL THREAT OF A STORM
GOING UP ON LAKE BREEZE THURSDAY AFTERNOON AS WELL...BUT WITH UPPER
HEIGHTS RISING FURTHER AND NO APPARENT TRIGGER...PLUS WEAKER DEEP
LAYER SHEAR/CONDITIONAL SEVERE THREAT HAVE OPTED TO KEEP FORECAST
DRY FOR NOW...BUT THIS WILL NEED TO BE RE-ACCESSED IN SUBSEQUENT
FORECASTS.
INITIALLY EXPECTING FROPA FRIDAY TO BE DRY AS FRONT SHOULD BE
SHALLOW AND UPPER HEIGHTS VERY HIGH...BUT WITH TIME THE UPPER RIDGE
WILL GET BEAT DOWN OVER THE WEEKEND WITH GRADUALLY
INCREASING...THOUGH STILL RATHER LOW...CHANCES FOR SHOWERS AND
THUNDERSTORMS AS BOUNDARY HANGS UP IN THE AREA. MAJORITY OF THE
WEEKEND SHOULD END UP DRY...HOWEVER IT COULD RAIN AT ANY TIME WHICH
NECESSITATES CARRYING POPS EACH PERIOD UNFORTUNATELY. MUCH MORE
SEASONABLE TEMPS AND COMFORTABLE HUMIDITY LEVELS ARE EXPECTED BY
LATE IN THE WEEKEND INTO NEXT WEEK. ANY AREA THAT DOES NOT PICK UP
SIGNIFICANT RAINFALL THIS WEEKEND WILL BE UNLIKELY TO SEE ANY
DROUGHT RELIEF NEXT WEEK AS ALL CURRENT INDICATIONS IN MEDIUM RANGE
GUIDANCE SUGGESTS WE WILL BE AN ANOTHER DRY PATTERN WITH LITTLE HOPE
FOR APPRECIABLE PRECIP UNTIL AT LEAST THE MIDDLE OF JULY.
IZZI
&&
.CLIMATE...
520 AM CDT
CHICAGO ROCKFORD
WED 102 80 101 77
1911 1921 1911 1977
THU 102 82 100 77
1911 1911 1911 1911
FRI 99 80 102 73
1988 1977 1936 1948
THE ALL TIME RECORD HIGH FOR CHICAGO IS 105 SET BACK ON JULY 24
1934...AND FOR ROCKFORD IS 112 SET ON JULY 14 1936.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* POSSIBLE LAKE BREEZE THIS AFTERNOON...NOT EXPECTED TO REACH
ORD/MDW.
//DISCUSSION...UPDATED 06Z...
SOUTHWEST WINDS AROUND 5KT OR SO OVERNIGHT WILL TURN MORE WESTERLY
LATER THIS MORNING INTO THIS AFTERNOON WITH SPEEDS INCREASING TO
10-12 KTS. THIS SHOULD BE SUFFICIENT TO PREVENT A LAKE BREEZE FROM
MOVING TOO FAR INLAND...BUT THE GRADIENT IS JUST WEAK ENOUGH THAT
A LAKE BREEZE WILL PROBABLY FORM AT THE SHORE BY LATE AFTERNOON
AND COULD POTENTIALLY TURN WINDS NORTHERLY AT GYY. THE LAKE
BREEZE...ASSUMING IT FORMS...COULD POSSIBLY AID ISOLATED TSRA
DEVELOPMENT BUT CONFIDENCE FAR TOO LOW FOR ANY MENTION IN THIS
FORECAST. CMS
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM CONFIDENCE REGARDING WIND SPEEDS/DIRECTIONS AND LAKE
BREEZE REMAINING EAST OF ORD/MDW. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
* THURSDAY...VFR.
* FRIDAY...VFR.
* SATURDAY THROUGH MONDAY...VFR. SLIGHT CHANCE OF TSRA.
KJB
&&
.MARINE...
306 AM...A WEAK COLD FRONT WILL MOVE SOUTH ACROSS LAKE MICHIGAN
TODAY AND WASH OUT AS IT REACHES THE SOUTH/CENTRAL PORTION OF THE
LAKE...MKE/MKG REGION. WHILE WINDS WILL TURN NORTHERLY...SPEEDS
WILL BE FAIRLY LIGHT. AS STRONG LOW PRESSURE MOVES ACROSS CANADA
OVER THE NEXT FEW DAYS...THE GRADIENT WILL RETURN SOUTHERLY WINDS
ACROSS THE LAKE UNTIL FRIDAY MORNING...WHEN A TRAILING COLD FRONT
FROM THIS LOW MOVES SOUTH ACROSS THE LAKE. WITH HIGH PRESSURE
BUILDING ACROSS THE MIDWEST/UPPER LAKES BEHIND THIS FRONT...
APPEARS THERE WILL BE A PROLONGED PERIOD OF NORTHERLY WINDS WITH
SPEEDS IN THE 10-20 KT RANGE...ESPECIALLY ON THE SOUTH END OF THE
LAKE. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...EXCESSIVE HEAT WARNING...ILZ014 UNTIL 6 PM FRIDAY.
HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-ILZ032-
ILZ033-ILZ039 UNTIL 10 PM FRIDAY.
IN...HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 10 PM
FRIDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
306 AM CDT WED JUL 4 2012
.DISCUSSION...
412 PM CDT
SYNOPSIS...LARGE SCALE PATTERNS CHANGES VERY LITTLE THROUGH
FRIDAY...WITH A LARGE RIDGE STRETCHED ACROSS CONUS. MODEL CONSENSUS
IS HIGH THAT THE UPPER LEVEL RIDGE WILL BE CENTERED OVER
MISSOURI. AN UPPER LEVEL LOW MOVES ACROSS THE SOUTHERN CANADIAN
PRAIRIES AND REACHES HUDSON BAY LATE THURSDAY. THE UPPER LEVEL
TROUGH MOVES OVER QUEBEC OVER THE WEEKEND...WHILE THE RIDGE CENTER
SHIFTS WESTWARD. AS A RESULT...MUCH WELCOMED NORTHWEST FLOW USHERS
IN SLIGHTLY COOLER AIR FOR EARLY NEXT WEEK.
GIVEN UNCERTAINTIES IN CONVECTIVE DEVELOPMENT AND LAKE BREEZE
INFLUENCE...DECIDED TO EXTEND THE HEAT WATCH THROUGH 02Z FRIDAY FOR
COOK COUNTY...AND EXTEND THE CURRENT HEAT ADVISORY FOR THE REMAINDER
OF THE CWA THROUGH 02Z FRIDAY AS WELL.
THROUGH TONIGHT...
DESPITE OVER 3000 J/KG OF CAPE PER THE LATEST RUC ANALYSIS AND NO
CIN...A LACK OF FORCING HAS RESULTED IN PRIMARILY CLEAR SKIES AND A
LACK OF CONVECTIVE DEVELOPMENT. GIVEN LATEST TRENDS AND NO CLEAR
FORCING MECHANISM...DECIDED TO GO WITH A DRY FORECAST THROUGH
TONIGHT. THERE IS A MINIMAL CHANCE THAT A STRAY THUNDERSTORM MAY
DEVELOP...BUT GIVEN THE LACK OF OBVIOUS FORCING...BETTING AGAINST
IT.
WE STAY WARM TONIGHT WITH LOW TEMPS IN THE MID 70S...EXCEPT FOR NEAR
80 DOWNTOWN. HEAT INDICES TONIGHT WILL REMAIN IN THE 70S...PROVIDING
LITTLE RELIEF FROM THE MUGGY CONDITIONS.
TOMORROW AND THURSDAY...
TEMPERATURES CONTINUE TO INCREASE ON BOTH WEDNESDAY AND THURSDAY.
THE LATEST ECMWF RUN INDICATES THURSDAY WILL BE THE WARMEST DAY IN
THE FORECAST PERIOD. RAISED TEMPS ON WEDNESDAY AND THURSDAY BY A
COUPLE OF DEGREES. MIXING STRAIGHT DOWN FROM 850 HPA GAVE TEMPS IN
THE LOW TO MID HUNDREDS ON BOTH DAYS AND DECIDED THAT WAS TOO MUCH
OF AN INCREASE THIS FAR OUT. COULD SEE THURSDAY MAX TEMPS BE EVEN A
DEGREE OR TWO HIGHER. EITHER WAY BOTH DAYS WILL BE NEAR TO SLIGHTLY
ABOVE 100. MAX HEAT INDICES ON BOTH DAYS WILL VARY BETWEEN 100 AND
113 DEGREES. NOT EXPECTING MUCH RELIEF OVERNIGHT AS HEAT INDICES
WILL REMAIN IN THE MID 70S EXCEPT FOR NEAR 80 DOWNTOWN.
MODELS INDICATE CONVECTION WILL FIRE TO OUR NORTH AND TRY TO ROLL
DOWN THE FRONT OF THE RIDGE INTO NORTHEAST IL AND NORTHWEST IN.
GUIDANCE SUGGESTS THE CONVECTION WILL FIZZLE BEFORE CROSSING THE
WI/IL BORDER. HOWEVER...GIVEN A LAKE BREEZE IS LIKELY TO DEVELOP
TOMORROW AFTERNOON...KEPT THE CHANCE OF CONVECTION ALONG THE
LAKESHORE LATE TOMORROW AFTERNOON. A LAKE BREEZE IS ALSO LIKELY
THURSDAY AFTERNOON. BOTH OF THESE LAKE BREEZES COULD PROVIDE LATE
DAY RELIEF FROM THE HEAT...BUT AS OF RIGHT NOW BOTH ARE EXPECTED TO
DEVELOP AFTER DOWNTOWN HITS ITS MAX TEMP.
EXTENDED...FRIDAY THROUGH MONDAY...
THE EXTENDED FEATURES A TRANSITION FROM THE PERSISTENT UPPER LEVEL
RIDGE TO UPPER LEVEL NORTHWEST FLOW. THE OPPRESSIVE HEAT CONTINUES
THROUGH THE EARLY PART OF THE WEEKEND WITH RELIEF ARRIVING IN THE
FORM OF A BACKDOOR COLD FRONT. THE TIMING OF THIS COLD FRONT IS
DEBATABLE WITH THE MODELS DIFFERING ON ITS ARRIVAL. LEANING TOWARD
THE ECMWF/S STEADY SOLUTION WHICH FEATURES THE COLD FRONT MOVING IN
SUNDAY NIGHT INTO MONDAY MORNING. AS SUCH...RAISED ALLBLEND TEMPS
ON SATURDAY. LOOKING AT TEMPS AT OR JUST ABOVE 100 DEGREES ON
FRIDAY...THEN A BIT COOLER WITH MAX TEMPS IN THE UPPER 80S TO MID
90S. IF TRENDS CONTINUE TO LEAN TOWARD THE ECMWF...EXPECTING FUTURE
FORECASTS TO RAISE TEMPS EVEN FURTHER ON BOTH FRIDAY AND
SATURDAY...WITH SATURDAY MOST LIKELY REMAINING COOLER THAN FRIDAY.
ONCE AGAIN...TEMPS AND PRECIP ALL DEPEND ON THE TIMING OF THIS
FRONT. LEANED TOWARD THE ECMWF WITH THE EXTENDED PRECIP
FORECAST...BUT TO BLEND WELL WITH THE NEIGHBORS AND GIVEN HOW FAR
OUT THE FORECAST PERIOD IS...BLENDED IN A LITTLE OF THE GFS. SUNDAY
NIGHT AND MONDAY LOOK LIKE THE BEST CHANCES OF PRECIP AS THE FRONT
SINKS SOUTH THROUGH THE CWA. TEMPS BEHIND THE FROPA LOOK NEAR
NORMAL.
JEE
&&
.CLIMATE...
520 AM CDT
CHICAGO ROCKFORD
HIGH LOW HIGH LOW
TUE 102 78 99 74
1949 1911 1925 1911
WED 102 80 101 77
1911 1921 1911 1977
THU 102 82 100 77
1911 1911 1911 1911
FRI 99 80 102 73
1988 1977 1936 1948
THE ALL TIME RECORD HIGH FOR CHICAGO IS 105 SET BACK ON JULY 24
1934...AND FOR ROCKFORD IS 112 SET ON JULY 14 1936.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* POSSIBLE LAKE BREEZE THIS AFTERNOON...NOT EXPECTED TO REACH
ORD/MDW.
//DISCUSSION...UPDATED 06Z...
SOUTHWEST WINDS AROUND 5KT OR SO OVERNIGHT WILL TURN MORE WESTERLY
LATER THIS MORNING INTO THIS AFTERNOON WITH SPEEDS INCREASING TO
10-12 KTS. THIS SHOULD BE SUFFICIENT TO PREVENT A LAKE BREEZE FROM
MOVING TOO FAR INLAND...BUT THE GRADIENT IS JUST WEAK ENOUGH THAT
A LAKE BREEZE WILL PROBABLY FORM AT THE SHORE BY LATE AFTERNOON
AND COULD POTENTIALLY TURN WINDS NORTHERLY AT GYY. THE LAKE
BREEZE...ASSUMING IT FORMS...COULD POSSIBLY AID ISOLATED TSRA
DEVELOPMENT BUT CONFIDENCE FAR TOO LOW FOR ANY MENTION IN THIS
FORECAST. CMS
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM CONFIDENCE REGARDING WIND SPEEDS/DIRECTIONS AND LAKE
BREEZE REMAINING EAST OF ORD/MDW. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
* THURSDAY...VFR.
* FRIDAY...VFR.
* SATURDAY THROUGH MONDAY...VFR. SLIGHT CHANCE OF TSRA.
KJB
&&
.MARINE...
306 AM...A WEAK COLD FRONT WILL MOVE SOUTH ACROSS LAKE MICHIGAN
TODAY AND WASH OUT AS IT REACHES THE SOUTH/CENTRAL PORTION OF THE
LAKE...MKE/MKG REGION. WHILE WINDS WILL TURN NORTHERLY...SPEEDS
WILL BE FAIRLY LIGHT. AS STRONG LOW PRESSURE MOVES ACROSS CANADA
OVER THE NEXT FEW DAYS...THE GRADIENT WILL RETURN SOUTHERLY WINDS
ACROSS THE LAKE UNTIL FRIDAY MORNING...WHEN A TRAILING COLD FRONT
FROM THIS LOW MOVES SOUTH ACROSS THE LAKE. WITH HIGH PRESSURE
BUILDING ACROSS THE MIDWEST/UPPER LAKES BEHIND THIS FRONT...
APPEARS THERE WILL BE A PROLONGED PERIOD OF NORTHERLY WINDS WITH
SPEEDS IN THE 10-20 KT RANGE...ESPECIALLY ON THE SOUTH END OF THE
LAKE. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...EXCESSIVE HEAT WARNING...ILZ014 UNTIL 6 PM FRIDAY.
HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-ILZ032-
ILZ033-ILZ039 UNTIL 10 PM FRIDAY.
IN...HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 10 PM
FRIDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1224 AM CDT WED JUL 4 2012
.DISCUSSION...
412 PM CDT
SYNOPSIS...LARGE SCALE PATTERNS CHANGES VERY LITTLE THROUGH
FRIDAY...WITH A LARGE RIDGE STRETCHED ACROSS CONUS. MODEL CONSENSUS
IS HIGH THAT THE UPPER LEVEL RIDGE WILL BE CENTERED OVER
MISSOURI. AN UPPER LEVEL LOW MOVES ACROSS THE SOUTHERN CANADIAN
PRAIRIES AND REACHES HUDSON BAY LATE THURSDAY. THE UPPER LEVEL
TROUGH MOVES OVER QUEBEC OVER THE WEEKEND...WHILE THE RIDGE CENTER
SHIFTS WESTWARD. AS A RESULT...MUCH WELCOMED NORTHWEST FLOW USHERS
IN SLIGHTLY COOLER AIR FOR EARLY NEXT WEEK.
GIVEN UNCERTAINTIES IN CONVECTIVE DEVELOPMENT AND LAKE BREEZE
INFLUENCE...DECIDED TO EXTEND THE HEAT WATCH THROUGH 02Z FRIDAY FOR
COOK COUNTY...AND EXTEND THE CURRENT HEAT ADVISORY FOR THE REMAINDER
OF THE CWA THROUGH 02Z FRIDAY AS WELL.
THROUGH TONIGHT...
DESPITE OVER 3000 J/KG OF CAPE PER THE LATEST RUC ANALYSIS AND NO
CIN...A LACK OF FORCING HAS RESULTED IN PRIMARILY CLEAR SKIES AND A
LACK OF CONVECTIVE DEVELOPMENT. GIVEN LATEST TRENDS AND NO CLEAR
FORCING MECHANISM...DECIDED TO GO WITH A DRY FORECAST THROUGH
TONIGHT. THERE IS A MINIMAL CHANCE THAT A STRAY THUNDERSTORM MAY
DEVELOP...BUT GIVEN THE LACK OF OBVIOUS FORCING...BETTING AGAINST
IT.
WE STAY WARM TONIGHT WITH LOW TEMPS IN THE MID 70S...EXCEPT FOR NEAR
80 DOWNTOWN. HEAT INDICES TONIGHT WILL REMAIN IN THE 70S...PROVIDING
LITTLE RELIEF FROM THE MUGGY CONDITIONS.
TOMORROW AND THURSDAY...
TEMPERATURES CONTINUE TO INCREASE ON BOTH WEDNESDAY AND THURSDAY.
THE LATEST ECMWF RUN INDICATES THURSDAY WILL BE THE WARMEST DAY IN
THE FORECAST PERIOD. RAISED TEMPS ON WEDNESDAY AND THURSDAY BY A
COUPLE OF DEGREES. MIXING STRAIGHT DOWN FROM 850 HPA GAVE TEMPS IN
THE LOW TO MID HUNDREDS ON BOTH DAYS AND DECIDED THAT WAS TOO MUCH
OF AN INCREASE THIS FAR OUT. COULD SEE THURSDAY MAX TEMPS BE EVEN A
DEGREE OR TWO HIGHER. EITHER WAY BOTH DAYS WILL BE NEAR TO SLIGHTLY
ABOVE 100. MAX HEAT INDICES ON BOTH DAYS WILL VARY BETWEEN 100 AND
113 DEGREES. NOT EXPECTING MUCH RELIEF OVERNIGHT AS HEAT INDICES
WILL REMAIN IN THE MID 70S EXCEPT FOR NEAR 80 DOWNTOWN.
MODELS INDICATE CONVECTION WILL FIRE TO OUR NORTH AND TRY TO ROLL
DOWN THE FRONT OF THE RIDGE INTO NORTHEAST IL AND NORTHWEST IN.
GUIDANCE SUGGESTS THE CONVECTION WILL FIZZLE BEFORE CROSSING THE
WI/IL BORDER. HOWEVER...GIVEN A LAKE BREEZE IS LIKELY TO DEVELOP
TOMORROW AFTERNOON...KEPT THE CHANCE OF CONVECTION ALONG THE
LAKESHORE LATE TOMORROW AFTERNOON. A LAKE BREEZE IS ALSO LIKELY
THURSDAY AFTERNOON. BOTH OF THESE LAKE BREEZES COULD PROVIDE LATE
DAY RELIEF FROM THE HEAT...BUT AS OF RIGHT NOW BOTH ARE EXPECTED TO
DEVELOP AFTER DOWNTOWN HITS ITS MAX TEMP.
EXTENDED...FRIDAY THROUGH MONDAY...
THE EXTENDED FEATURES A TRANSITION FROM THE PERSISTENT UPPER LEVEL
RIDGE TO UPPER LEVEL NORTHWEST FLOW. THE OPPRESSIVE HEAT CONTINUES
THROUGH THE EARLY PART OF THE WEEKEND WITH RELIEF ARRIVING IN THE
FORM OF A BACKDOOR COLD FRONT. THE TIMING OF THIS COLD FRONT IS
DEBATABLE WITH THE MODELS DIFFERING ON ITS ARRIVAL. LEANING TOWARD
THE ECMWF/S STEADY SOLUTION WHICH FEATURES THE COLD FRONT MOVING IN
SUNDAY NIGHT INTO MONDAY MORNING. AS SUCH...RAISED ALLBLEND TEMPS
ON SATURDAY. LOOKING AT TEMPS AT OR JUST ABOVE 100 DEGREES ON
FRIDAY...THEN A BIT COOLER WITH MAX TEMPS IN THE UPPER 80S TO MID
90S. IF TRENDS CONTINUE TO LEAN TOWARD THE ECMWF...EXPECTING FUTURE
FORECASTS TO RAISE TEMPS EVEN FURTHER ON BOTH FRIDAY AND
SATURDAY...WITH SATURDAY MOST LIKELY REMAINING COOLER THAN FRIDAY.
ONCE AGAIN...TEMPS AND PRECIP ALL DEPEND ON THE TIMING OF THIS
FRONT. LEANED TOWARD THE ECMWF WITH THE EXTENDED PRECIP
FORECAST...BUT TO BLEND WELL WITH THE NEIGHBORS AND GIVEN HOW FAR
OUT THE FORECAST PERIOD IS...BLENDED IN A LITTLE OF THE GFS. SUNDAY
NIGHT AND MONDAY LOOK LIKE THE BEST CHANCES OF PRECIP AS THE FRONT
SINKS SOUTH THROUGH THE CWA. TEMPS BEHIND THE FROPA LOOK NEAR
NORMAL.
JEE
&&
.CLIMATE...
520 AM CDT
CHICAGO ROCKFORD
HIGH LOW HIGH LOW
TUE 102 78 99 74
1949 1911 1925 1911
WED 102 80 101 77
1911 1921 1911 1977
THU 102 82 100 77
1911 1911 1911 1911
FRI 99 80 102 73
1988 1977 1936 1948
THE ALL TIME RECORD HIGH FOR CHICAGO IS 105 SET BACK ON JULY 24
1934...AND FOR ROCKFORD IS 112 SET ON JULY 14 1936.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* POSSIBLE LAKE BREEZE THIS AFTERNOON...NOT EXPECTED TO REACH
ORD/MDW.
//DISCUSSION...UPDATED 06Z...
SOUTHWEST WINDS AROUND 5KT OR SO OVERNIGHT WILL TURN MORE WESTERLY
LATER THIS MORNING INTO THIS AFTERNOON WITH SPEEDS INCREASING TO
10-12 KTS. THIS SHOULD BE SUFFICIENT TO PREVENT A LAKE BREEZE FROM
MOVING TOO FAR INLAND...BUT THE GRADIENT IS JUST WEAK ENOUGH THAT
A LAKE BREEZE WILL PROBABLY FORM AT THE SHORE BY LATE AFTERNOON
AND COULD POTENTIALLY TURN WINDS NORTHERLY AT GYY. THE LAKE
BREEZE...ASSUMING IT FORMS...COULD POSSIBLY AID ISOLATED TSRA
DEVELOPMENT BUT CONFIDENCE FAR TOO LOW FOR ANY MENTION IN THIS
FORECAST. CMS
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM CONFIDENCE REGARDING WIND SPEEDS/DIRECTIONS AND LAKE
BREEZE REMAINING EAST OF ORD/MDW. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
* THURSDAY...VFR.
* FRIDAY...VFR.
* SATURDAY THROUGH MONDAY...VFR. SLIGHT CHANCE OF TSRA.
KJB
&&
.MARINE...
247 PM CDT
LOW PRESSURE PASSING NORTH OF THE LAKES ACROSS ONTARIO THIS EVENING
WILL TRAIL A WEAK COLD FRONT ACROSS THE WESTERN GREAT LAKES LATER
TONIGHT AND WEDNESDAY. THIS FRONT IS EXPECTED TO WASH OUT AS IT
SLIDES DOWN ACROSS CENTRAL AND SOUTHERN LAKE MICHIGAN WEDNESDAY...
WITH THE FRONT REDEVELOPING BACK TO THE NORTH IN RESPONSE TO ANOTHER
LOW MOVING ACROSS SASKATCHEWAN AND MANITOBA. THIS SECOND LOW WILL
MOVE EAST ACROSS NORTHERN ONTARIO AND HUDSON BAY THROUGH THURSDAY
AND WILL DRAG ANOTHER FAIRLY WEAK COLD FRONT ACROSS LAKE MICHIGAN
THURSDAY NIGHT INTO FRIDAY. WHILE THE INITIAL PUSH OF COOLER WILL BE
RATHER MEAGER...HIGH PRESSURE BUILDING ACROSS ONTARIO AND THE
NORTHERN LAKES SATURDAY WILL BRING SLIGHTLY STRONGER NORTH WINDS AND
COOLER AIR ACROSS LAKE MICHIGAN INTO THE WEEKEND.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY...ILZ014 UNTIL 7 AM WEDNESDAY.
EXCESSIVE HEAT WATCH...ILZ014...7 AM WEDNESDAY TO 9 PM THURSDAY.
HEAT ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-ILZ032-
ILZ033-ILZ039 UNTIL 9 PM THURSDAY.
IN...HEAT ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 9 PM
THURSDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION...CORRECTION
NWS QUAD CITIES IA IL
613 PM CDT THU JUL 5 2012
.AVIATION...
VFR WX WILL CONTINUE THROUGH 00Z/07 WITH DENSITY ALTITUDES AOA
3KFT 18Z/05-02Z/06 AND AGAIN AFT 16Z/06. NO RAIN...OR CLOUDS UNDER
25KFT SHOULD OCCUR. VISIBILITIES WILL BE 6 MILES OR BETTER
THROUGH THE PERIOD. WINDS WILL BE LIGHT SOUTH THROUGH 01Z...THEN
POSSIBLY LIGHT AND VARIABLE THROUGH 14Z...AFTER WHICH SOUTH AROUND
8 TO 10 KTS AGAIN.
ERVIN
&&
.PREV DISCUSSION... /ISSUED 319 PM CDT THU JUL 5 2012/
SYNOPSIS...
12Z UA ANALYSIS HAD A LLJ RUNNING FROM WEST TEXAS INTO NORTHWEST
IOWA. AN 850MB BOUNDARY/FRONT RAN FROM THE ARROWHEAD OF MINNESOTA
INTO WESTERN NEBRASKA. MOISTURE WAS POOLING AHEAD OF THE BOUNDARY
WITH 850MB DEW POINTS IN THE MID AND UPPER TEENS FROM SOUTHERN
MINNESOTA INTO WISCONSIN. SATELLITE TRENDS THROUGH MID AFTERNOON
SHOW CLOUDS CONTINUE TO THIN FROM THE NOCTURNAL CONVECTION OVER
THE AREA WITH DIURNAL CU AND ISOLATED CONVECTION IN NORTHEAST
ILLINOIS.
18Z SFC ANALYSIS HAD WEAK LOWS NEAR KLSE AND KSUX. AN OUTFLOW
BOUNDARY CONNECTED THE TWO LOWS AND RAN ACROSS NORTHERN IOWA. THE
MAIN COLD FRONT RAN FROM WESTERN LAKE SUPERIOR TO KFSD AND THEN
INTO SOUTHERN SOUTH DAKOTA. DEW POINTS WERE IN THE 40S AND 50S
BEHIND THE FRONT WITH WIDESPREAD 60S AND SOME 70S AHEAD OF THE FRONT.
SHORT TERM...TONIGHT AND FRIDAY
THERE IS SOME MOISTURE ABOVE THE LFC SO THERE REALLY IS NO CAP.
THE LACK OF A TRIGGER HAS SO FAR PREVENTED ANY ELEVATED CONVECTION
FROM DEVELOPING. ELEVATED CONVECTION HAS DEVELOPED IN NORTHEAST
ILLINOIS IN RESPONSE TO WEAK FORCING PER THE RAP MODEL. DIURNAL CU
HAS DEVELOPED ALONG THE TRUE COLD FRONT AND VISIBLE/WATER VAPOR
IMAGERY INDICATES A WEAK VORT MAX OR MCV MOVING ACROSS SOUTHERN
MINNESOTA. THUS CONVECTION SHOULD DEVELOP IN THE NEXT FEW HOURS IN
MINNESOTA ALONG THE FRONT.
THE CONVECTION IN NORTHEAST ILLINOIS WILL NEED TO BE WATCHED. RAP
TRENDS SHOW THE WEAK FORCING GETTING CLOSE TO THE EASTERN CWFA
LATE THIS AFTERNOON. MCS...LIFT...AND WAA TOOLS ALL SUGGEST
ADDITIONAL CONVECTION DEVELOPING LATE THIS AFTERNOON IN NORTHEAST
ILLINOIS THAT MAY APPROACH THE FAR NORTHEAST/EAST PARTS OF THE
CWFA. IF NOTHING DEVELOPS BY 6 PM...THEN THE CWFA SHOULD BE DRY
THROUGH MIDNIGHT.
AFTER MIDNIGHT ANOTHER MCS SHOULD DEVELOP IN SOUTHERN MINNESOTA
AND GENERALLY MOVE EAST. THE GENESIS REGION SHOULD BE SOUTHWEST
MINNESOTA IN THE STRONGEST PART OF THE WEAK LLJ. OUTFLOWS FROM
THIS MCS MAY INITIATE NEW CONVECTION PRIOR TO SUNRISE JUST OUTSIDE
OF THE CWFA.
ASSUMING THE MINNESOTA MCS DEVELOPS AND MOVES EAST AS EXPECTED
THEN FRIDAY SHOULD SEE PLENTY OF DEBRIS CLOUDS THAT TAKE MOST OF
THE MORNING TO THIN AND DISSIPATE. THESE CLOUDS IN TURN SHOULD
HOLD DOWN TEMPERATURES JUST A LITTLE BUT MAX TEMPERATURES SHOULD
BE SIMILAR TO OR 1-2 DEGREES WARMER THAN TODAY.
THE HEAT HEADLINES WILL REMAIN WITH NO CHANGES. DEW POINTS SHOULD
AGAIN DROP TONIGHT AS EVAPOTRANSPIRATION FROM THE CORN BECOMES
INACTIVE. DEW POINTS WILL CLIMB AGAIN FRIDAY INTO THE UPPER 60S TO
POSSIBLY MID 70S AS THE CORN ACTIVELY EVAPOTRANSPIRATES. THE
RESULTANT HEAT INDEX READINGS SHOULD BE 105 TO 110. ..08..
LONG TERM...FRIDAY NIGHT THROUGH NEXT THURSDAY
BREAK IN THE HEAT WITH MORE SEASONABLE TEMPS AND COMFORTABLE HUMIDITY
ARRIVING BY LATE IN THE WEEKEND. THE FRONT BRINGING THE RELIEF
UNFORTUNATELY DOESN/T FIGURE TO BRING MUCH IN WAY OF NEEDED RAINFALL
FOR AREA CORN CROPS IN CRITICAL POLLINATION STAGE. MOST OF THE
AREA IS NOW EXPERIENCING MODERATE DROUGHT CONDITIONS PER THE LATEST
U.S. DROUGHT MONITOR RELEASED THIS AM.
SURFACE COLD FRONT TO SAG THROUGH THE REGION SAT INTO SAT NGT. FRI
NGT WILL FEATURE CONTINUATION OF EXCESSIVE HEAT WARNING WITH VERY
WARM AND HUMID CONDITIONS WITH HEAT INDICES REMAINING ABOVE 75. NOT
LIKELY TO SEE SFC BASED PRE-FRONTAL CONVECTION SAT INTO SAT EVE DUE
TO STRONG CAPPING INVERSION... WEAK LOW LEVEL CONVERGENCE AND
ABSENCE OF PRONOUNCED SHORTWAVE AND MID LEVEL COOLING. THUS... ANY
PCPN WOULD BE POST-FRONTAL ROOTED WITH CONVERGENCE AXIS NEAR TO
ABOVE 850 MILLIBARS ALSO COINCIDENT WITH DEEPER MOISTURE FETCH WITH
MONSOONAL CONNECTION ROTATING AROUND THE PERIPHERY OF THE UPPER
RIDGE /HEAT DOME/ TO OUR SOUTH. WITH LACK OF CONVECTION PRE-FRONTAL
THEN LESS DEBRIS CLOUDINESS THUS INCREASING LIKELIHOOD OF NEEDING TO
EXTEND HEAT WARNING THROUGH SAT FOR A GOOD PORTION OF THE CWA FOR
HIGHS ONCE AGAIN WELL INTO THE 90S TO AROUND 100F AND HEAT INDICES
100-110+. 850 MILLIBAR FRONT OR WEAKENING CONVERGENCE AXIS PASSES
SUN INTO SUN EVE TAKING MOISTURE WITH IT. ASIDE FROM THE WEAK
CONVERGENCE HARD PRESSED TO FIND COHERENT FORCING OR TRIGGER TO
GENERATE WIDESPREAD OR ORGANIZED RAIN. GIVEN ALL OF THE ABOVE HAVE
BACKED OFF ON POPS TO MAINLY SLIGHT CHC DURING THE ENTIRE PERIOD
SAT-SUN.
MON-THU... GENERAL PATTERN WILL FEATURE A BROAD TROUGH OVER THE
CENTRAL AND EASTERN CONUS... AND RIDGE OVER THE INTERMOUNTAIN
WEST. RESULTING NORTHWEST FLOW WILL KEEP TEMPS AROUND NORMAL WHICH
COUPLED WITH LOWER HUMIDITY TO MAKE FOR NICE AND COMFORTABLE STRETCH
OF WEATHER. PCPN CHCS ARE NOT ZERO AS WE COULD SEE A FEW SHORTWAVES
PASS IN THE FLOW... BUT WITH LIMITED MOISTURE AND TIMING/STRENGTH
SO DIFFICULT TO PIN DOWN THIS FAR OUT HAVE MAINTAINED A DRY FORECAST.
MCCLURE
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...EXCESSIVE HEAT WARNING UNTIL 7 AM CDT SATURDAY FOR BENTON-
BUCHANAN-CEDAR-CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-
IOWA-JACKSON-JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-
MUSCATINE-SCOTT-VAN BUREN-WASHINGTON.
IL...EXCESSIVE HEAT WARNING UNTIL 7 AM CDT SATURDAY FOR BUREAU-
CARROLL-HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-
MERCER-PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE.
MO...EXCESSIVE HEAT WARNING UNTIL 7 AM CDT SATURDAY FOR CLARK-
SCOTLAND.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
611 PM CDT THU JUL 5 2012
.AVIATION...
VFR WX WILL CONTINUE THROUGH 00Z/07 WITH DENSITY ALTITUDES AOA
3KFT 18Z/05-02Z/06 AND AGAIN AFT 16Z/06. NO RAIN...OR CLOUDS UNDER
250KFT SHOULD OCCUR. VISIBILITIES WILL BE 6 MILES OR BETTER
THROUGH THE PERIOD. WINDS WILL BE LIGHT SOUTH THROUGH 01Z...THEN
POSSIBLY LIGHT AND VARIABLE THROUGH 14Z...AFTER WHICH SOUTH AROUND
8 TO 10 KTS AGAIN.
ERVIN
&&
.PREV DISCUSSION... /ISSUED 319 PM CDT THU JUL 5 2012/
SYNOPSIS...
12Z UA ANALYSIS HAD A LLJ RUNNING FROM WEST TEXAS INTO NORTHWEST
IOWA. AN 850MB BOUNDARY/FRONT RAN FROM THE ARROWHEAD OF MINNESOTA
INTO WESTERN NEBRASKA. MOISTURE WAS POOLING AHEAD OF THE BOUNDARY
WITH 850MB DEW POINTS IN THE MID AND UPPER TEENS FROM SOUTHERN
MINNESOTA INTO WISCONSIN. SATELLITE TRENDS THROUGH MID AFTERNOON
SHOW CLOUDS CONTINUE TO THIN FROM THE NOCTURNAL CONVECTION OVER
THE AREA WITH DIURNAL CU AND ISOLATED CONVECTION IN NORTHEAST
ILLINOIS.
18Z SFC ANALYSIS HAD WEAK LOWS NEAR KLSE AND KSUX. AN OUTFLOW
BOUNDARY CONNECTED THE TWO LOWS AND RAN ACROSS NORTHERN IOWA. THE
MAIN COLD FRONT RAN FROM WESTERN LAKE SUPERIOR TO KFSD AND THEN
INTO SOUTHERN SOUTH DAKOTA. DEW POINTS WERE IN THE 40S AND 50S
BEHIND THE FRONT WITH WIDESPREAD 60S AND SOME 70S AHEAD OF THE FRONT.
SHORT TERM...TONIGHT AND FRIDAY
THERE IS SOME MOISTURE ABOVE THE LFC SO THERE REALLY IS NO CAP.
THE LACK OF A TRIGGER HAS SO FAR PREVENTED ANY ELEVATED CONVECTION
FROM DEVELOPING. ELEVATED CONVECTION HAS DEVELOPED IN NORTHEAST
ILLINOIS IN RESPONSE TO WEAK FORCING PER THE RAP MODEL. DIURNAL CU
HAS DEVELOPED ALONG THE TRUE COLD FRONT AND VISIBLE/WATER VAPOR
IMAGERY INDICATES A WEAK VORT MAX OR MCV MOVING ACROSS SOUTHERN
MINNESOTA. THUS CONVECTION SHOULD DEVELOP IN THE NEXT FEW HOURS IN
MINNESOTA ALONG THE FRONT.
THE CONVECTION IN NORTHEAST ILLINOIS WILL NEED TO BE WATCHED. RAP
TRENDS SHOW THE WEAK FORCING GETTING CLOSE TO THE EASTERN CWFA
LATE THIS AFTERNOON. MCS...LIFT...AND WAA TOOLS ALL SUGGEST
ADDITIONAL CONVECTION DEVELOPING LATE THIS AFTERNOON IN NORTHEAST
ILLINOIS THAT MAY APPROACH THE FAR NORTHEAST/EAST PARTS OF THE
CWFA. IF NOTHING DEVELOPS BY 6 PM...THEN THE CWFA SHOULD BE DRY
THROUGH MIDNIGHT.
AFTER MIDNIGHT ANOTHER MCS SHOULD DEVELOP IN SOUTHERN MINNESOTA
AND GENERALLY MOVE EAST. THE GENESIS REGION SHOULD BE SOUTHWEST
MINNESOTA IN THE STRONGEST PART OF THE WEAK LLJ. OUTFLOWS FROM
THIS MCS MAY INITIATE NEW CONVECTION PRIOR TO SUNRISE JUST OUTSIDE
OF THE CWFA.
ASSUMING THE MINNESOTA MCS DEVELOPS AND MOVES EAST AS EXPECTED
THEN FRIDAY SHOULD SEE PLENTY OF DEBRIS CLOUDS THAT TAKE MOST OF
THE MORNING TO THIN AND DISSIPATE. THESE CLOUDS IN TURN SHOULD
HOLD DOWN TEMPERATURES JUST A LITTLE BUT MAX TEMPERATURES SHOULD
BE SIMILAR TO OR 1-2 DEGREES WARMER THAN TODAY.
THE HEAT HEADLINES WILL REMAIN WITH NO CHANGES. DEW POINTS SHOULD
AGAIN DROP TONIGHT AS EVAPOTRANSPIRATION FROM THE CORN BECOMES
INACTIVE. DEW POINTS WILL CLIMB AGAIN FRIDAY INTO THE UPPER 60S TO
POSSIBLY MID 70S AS THE CORN ACTIVELY EVAPOTRANSPIRATES. THE
RESULTANT HEAT INDEX READINGS SHOULD BE 105 TO 110. ..08..
LONG TERM...FRIDAY NIGHT THROUGH NEXT THURSDAY
BREAK IN THE HEAT WITH MORE SEASONABLE TEMPS AND COMFORTABLE HUMIDITY
ARRIVING BY LATE IN THE WEEKEND. THE FRONT BRINGING THE RELIEF
UNFORTUNATELY DOESN/T FIGURE TO BRING MUCH IN WAY OF NEEDED RAINFALL
FOR AREA CORN CROPS IN CRITICAL POLLINATION STAGE. MOST OF THE
AREA IS NOW EXPERIENCING MODERATE DROUGHT CONDITIONS PER THE LATEST
U.S. DROUGHT MONITOR RELEASED THIS AM.
SURFACE COLD FRONT TO SAG THROUGH THE REGION SAT INTO SAT NGT. FRI NGT
WILL FEATURE CONTINUATION OF EXCESSIVE HEAT WARNING WITH VERY WARM
AND HUMID CONDITIONS WITH HEAT INDICES REMAINING ABOVE 75. NOT LIKELY
TO SEE SFC BASED PRE-FRONTAL CONVECTION SAT INTO SAT EVE DUE TO STRONG
CAPPING INVERSION... WEAK LOW LEVEL CONVERGENCE AND ABSENCE OF
PRONOUNCED SHORTWAVE AND MID LEVEL COOLING. THUS... ANY PCPN WOULD BE
POST-FRONTAL ROOTED WITH CONVERGENCE AXIS NEAR TO ABOVE 850 MILLIBARS
ALSO COINCIDENT WITH DEEPER MOISTURE FETCH WITH MONSOONAL CONNECTION
ROTATING AROUND THE PERIPHERY OF THE UPPER RIDGE /HEAT DOME/ TO OUR SOUTH.
WITH LACK OF CONVECTION PRE-FRONTAL THEN LESS DEBRIS CLOUDINESS THUS
INCREASING LIKELIHOOD OF NEEDING TO EXTEND HEAT WARNING THROUGH
SAT FOR A GOOD PORTION OF THE CWA FOR HIGHS ONCE AGAIN WELL INTO THE
90S TO AROUND 100F AND HEAT INDICES 100-110+. 850 MILLIBAR FRONT
OR WEAKENING CONVERGENCE AXIS PASSES SUN INTO SUN EVE TAKING MOISTURE
WITH IT. ASIDE FROM THE WEAK CONVERGENCE HARD PRESSED TO FIND COHERENT
FORCING OR TRIGGER TO GENERATE WIDESPREAD OR ORGANIZED RAIN. GIVEN
ALL OF THE ABOVE HAVE BACKED OFF ON POPS TO MAINLY SLIGHT CHC DURING THE
ENTIRE PERIOD SAT-SUN.
MON-THU... GENERAL PATTERN WILL FEATURE A BROAD TROUGH OVER THE
CENTRAL AND EASTERN CONUS... AND RIDGE OVER THE INTERMOUNTAIN
WEST. RESULTING NORTHWEST FLOW WILL KEEP TEMPS AROUND NORMAL WHICH
COUPLED WITH LOWER HUMIDITY TO MAKE FOR NICE AND COMFORTABLE STRETCH
OF WEATHER. PCPN CHCS ARE NOT ZERO AS WE COULD SEE A FEW SHORTWAVES
PASS IN THE FLOW... BUT WITH LIMITED MOISTURE AND TIMING/STRENGTH
SO DIFFICULT TO PIN DOWN THIS FAR OUT HAVE MAINTAINED A DRY FORECAST.
MCCLURE
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...EXCESSIVE HEAT WARNING UNTIL 7 AM CDT SATURDAY FOR BENTON-
BUCHANAN-CEDAR-CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-
IOWA-JACKSON-JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-
MUSCATINE-SCOTT-VAN BUREN-WASHINGTON.
IL...EXCESSIVE HEAT WARNING UNTIL 7 AM CDT SATURDAY FOR BUREAU-
CARROLL-HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-
MERCER-PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE.
MO...EXCESSIVE HEAT WARNING UNTIL 7 AM CDT SATURDAY FOR CLARK-
SCOTLAND.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1137 PM CDT TUE JUL 3 2012
.AVIATION...
VFR WEATHER IS EXPECTED OVER THE NEXT 24 HOURS...WITH GENERALLY
CLEAR SKIES AND EXCELLENT VISIBILITY. WIDESPREAD HIGH PRESSURE
WILL PROVIDE THE CLEAR SKIES...AND HOT WEATHER FOUND IN THE
REGION. ANY THUNDERSTORM ACTIVITY SHOULD REMAIN SOUTH OF
IOWA...AND NORTH OF IOWA AND ILLINOIS THROUGH TOMORROW. ERVIN
&&
.PREV DISCUSSION... /ISSUED 328 PM CDT TUE JUL 3 2012/
SYNOPSIS...
12Z UA ANALYSIS HAD AN 850MB LOW IN NORTHWEST SOUTH DAKOTA WITH A
WARM FRONT INTO SOUTHWEST MINNESOTA. AN INFERRED BOUNDARY RAN
ALONG THE MN/IA BORDER AND INTO SOUTHERN WISCONSIN. DEW POINTS ON
THIS BOUNDARY WERE IN THE MID TEENS. A DECAYING LLJ RAN FROM WEST
TEXAS INTO SOUTHWEST IOWA THAT WAS IN AN AXIS OF MID TEEN DEW
POINTS AS WELL. SATELLITE TRENDS THROUGH MID AFTERNOON SHOW
DIURNAL CU TRYING TO DEVELOP IN THE REMNANT COLD POOL OF LAST
NIGHTS MCS IN WISCONSIN AND FROM MISSOURI INTO ILLINOIS.
18Z SFC ANALYSIS HAS A LOW AT KMHE AND ANOTHER IN NORTHEAST SOUTH
DAKOTA. AN IMPLIED BOUNDARY RAN SOUTHEAST INTO NORTHEAST IOWA WITH
ANOTHER IMPLIED BOUNDARY FROM WESTERN WISCONSIN INTO NORTHEAST
ILLINOIS. DEW POINTS WERE IN THE LOW 70S ACROSS THE MID
MISSISSIPPI VALLEY WITH GENERALLY 60S ELSEWHERE.
SHORT TERM...TONIGHT AND WEDNESDAY
THE CLOUD COVER FROM THE NOCTURNAL MCS IS HOLDING TEMPERATURES
DOWN COMPARED TO YESTERDAY. AS A RESULT...THE HEAT ADVISORY IS
JUST BARELY VERIFYING AT MID AFTERNOON.
DEW POINTS HAVE BEEN INTERESTING. TODAY AND YESTERDAY DEW POINTS
HAVE RISEN DURING THE DAY AND THEN DROPPED AT NIGHT. THE ONLY
EXPLANATION THAT MAKES SENSE FOR THIS OCCURRING IS CORN. ONCE THE
SUN COMES UP THE CORN STARTS TO ACTIVELY EVAPOTRANSPIRATE. WITH
SUNSET THE EVAPOTRANSPIRATION SHUTS DOWN.
THEREFORE...WILL GO WITH THE IDEA OF DEW POINTS DROPPING TONIGHT
AND THEN INCREASING DURING THE DAY ON WEDNESDAY.
THE CU DEVELOPMENT ACROSS WISCONSIN AND MISSOURI INTO CENTRAL
ILLINOIS SO FAR HAS NOT SHOWN MUCH ADDITIONAL DEVELOPMENT. THESE
DIURNAL CLOUDS WILL HAVE TO BE WATCHED CAREFULLY FOR FURTHER
DEVELOPMENT THROUGH LATE AFTERNOON. BASED ON RAP TRENDS...
CONVECTION MAY STILL BE POSSIBLE FROM MID TO LATE AFTERNOON AND
INTO THE EARLY EVENING JUST OUTSIDE OF THE CWFA.
A BIGGER QUESTION IS WHAT HAPPENS LATER TONIGHT. SATELLITE HAS A
VERY SUBTLE WAVE MOVING INTO SOUTHWEST MINNESOTA WITH POSSIBLY
ANOTHER BACK IN THE DAKOTAS. RAP TRENDS SHOW THESE FEATURES IN THE
500MB FLOW. THE PROXIMITY OF A SFC LOW IN EASTERN SOUTH DAKOTA
COMBINED WITH THE LLJ INCREASING IN THE PLAINS THIS EVENING SHOULD
BE JUST ENOUGH TO INITIATE ANOTHER NOCTURNAL MCS. THE LLJ IS
WEAKER OVER THE CWFA SO THE MCS SHOULD MOVE GENERALLY EAST ACROSS
MINNESOTA INTO WISCONSIN. OUTFLOW FROM THIS MCS WILL LIKELY
GENERATE NEW CONVECTION THAT WILL DECAY AND DISSIPATE ALONG THE
NORTHERN CWFA BORDER LIKE THIS MORNING. DEBRIS CLOUDS THEN PLAY
INTO TEMPERATURES ON WEDNESDAY.
ON WEDNESDAY...WILL GO THE THE IDEA THAT DEBRIS CLOUDS FROM
NOCTURNAL CONVECTION WILL INITIALLY HOLD TEMPERATURES BACK UNTIL
IT THINS BY MID TO LATE MORNING. ASSUMING THIS SCENARIO IS
CORRECT...MAX TEMPERATURES MAY ONLY BE SLIGHTLY WARMER WEDNESDAY
THAN THEY ARE TODAY.
REGARDING HEADLINES...WILL CONTINUE WITH THE HEAT ADVISORY. IF DEW
POINTS DROP TONIGHT AS THEY HAVE THE PREVIOUS TWO NIGHTS...HEAT
INDEX VALUES MAY DROP INTO THE MID 70S PRIOR TO SUNRISE. GIVEN THE
LENGTH OF TIME THE HEAT IS EXPECTED TO BE AROUND...THE HEAT
ADVISORY WILL LIKELY TRANSITION INTO AN EXCESSIVE HEAT WARNING
POSSIBLY AS EARLY AS WEDNESDAY. ..08..
LONG TERM...WEDNESDAY NIGHT THROUGH NEXT TUESDAY
FOCUS REMAINS ON THE EXTENDED PERIOD OF HIGH HEAT AND HUMIDITY.
PATTERN CHANGE OVER THE WEEKEND LOOKS TO BRING SOME RELIEF IN THE
FORM OF RAIN CHANCES AND SLIGHTLY COOLER TEMPERATURES.
THE STAGNANT WEATHER PATTERN RESULTING FROM AN UPPER RIDGE AND HEAT
DOME OVER THE CENTRAL U.S. WILL CHANGE LITTLE THROUGH THE REST OF
THE WORKWEEK. LOCALLY...THE HEAT AND HIGH HEAT INDEX READINGS WILL
WORSEN AS AN EASTWARD SHIFT IN THE HIGH CENTER SENDS THE DOME OF
HEAT ALOFT NORTHEAST FROM THE PLAINS. USING A MIDDLE OF THE ROAD
ECM GUIDANCE...WHICH IS BETWEEN THE TOO WARM NAM AND TOO COOL
TRENDING GFS...BY THURSDAY 850 MB TEMPERATURES ARE EXPECTED TO CLIMB
ABOUT 4 TO 5 DEGREES C WARMER THAN THIS MORNING...AND 925 MB
TEMPERATURES AROUND 6 TO 7 DEGREES C WARMER. THIS WOULD EASILY DRIVE
MAX TEMPERATURES INTO THE 100 TO 105 RANGE...HOWEVER...SURFACE
DEWPOINTS AND LOW LEVEL MOISTURE FEEDBACK ON TEMPERATURES REMAINS
PROBLEMATIC. EVAPOTRANSPIRATION FROM MATURING FIELD CROPS APPEARS TO
BE THE CULPRIT FOR DEWPOINTS CLIMBING INTO THE 70S DURING WEAK
MIXING AT NIGHT...WHICH TODAY ARE REMAINING HIGH DESPITE 10 TO 20 KT
WINDS. MODELS WILL NOT LIKELY HANDLE THIS FEEDBACK PROPERLY AND THUS
THE DRIER NAM WITH ITS LOWER DEWPOINTS AND WIDESPREAD 104 TO 107 MAX
TEMPERATURE RANGE FOR THU IS SUSPECT...WHILE THE EQUALLY TOO MOIST
TRENDING GFS IS TOO COOL AND UNUSABLE. FOLLOWING MORE CLOSELY THE
BIAS CORRECTED MODELS AND 12Z ECM...HAVE KEPT THU AS THE WARMEST OF
THE STRETCH WITH A COMPROMISE 99 TO 102 RANGE FOR HIGHS. USING TODAY AS
A MODEL...HAVE KEPT DEWPOINTS RELATIVELY HIGH IN THE UPPER 60S TO
LOWER 70S...WHICH WOULD RESULT IN HEAT INDEX READINGS INTO A 105 TO
110 RANGE IN THE AFTERNOON INTO EARLY EVENING. THIS WOULD BE WELL
INTO EXCESSIVE HEAT WARNING CRITERIA...HOWEVER...DUE TO LOW
CONFIDENCE IN THESE CRITICAL DEWPOINT VALUES...WILL HOLD OFF ON A
WARNING AS THE HEAT ADVISORY IS ALREADY IN PLACE FOR THESE PERIODS.
SLIGHT COOLING ALOFT IS NOTED FOR FRIDAY AND MODELS DROP A WEAK
FRONT SOUTH TOWARD THE FAR NORTHERN FORECAST AREA BY LATE IN THE
DAY. HAVE THUS LIMITED HIGHS TO THE 90S...WHILE HEAT INDICES AGAIN
PUSH TO AT LEAST 100 TO 105. OVERNIGHT TEMPERATURES FROM WED NIGHT
THROUGH AT LEAST FRIDAY NIGHT WILL BE IN THE 70S...CONTINUING AN
EXTENDED PERIOD OF HIGH HEAT INDICES ALSO SUPPORTING THE ON-GOING
ADVISORY.
SATURDAY THROUGH TUESDAY...THE UPPER RIDGE BEGINS TO BREAK DOWN AS A
TROUGH DEVELOPS OVER THE EASTERN U.S. AND AN NEW UPSTREAM RIDGE
BUILDS OVER THE ROCKIES. THE RESULTING NW FLOW ALOFT WILL ALLOW THE
MORE ACTIVE FRONTAL ZONE TO DROP SOUTH AND AFFECT THE
AREA...RESULTING IN AN EXTENDED PERIOD OF LOW POPS FOR RAIN AND
THUNDERSTORMS...ALONG WITH PROGRESSIVELY COOLER TEMPERATURES.
SHEETS
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...HEAT ADVISORY UNTIL 7 AM CDT SATURDAY FOR BENTON-BUCHANAN-CEDAR-
CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-IOWA-JACKSON-
JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-MUSCATINE-
SCOTT-VAN BUREN-WASHINGTON.
IL...HEAT ADVISORY UNTIL 7 AM CDT SATURDAY FOR BUREAU-CARROLL-HANCOCK-
HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER-PUTNAM-ROCK
ISLAND-STEPHENSON-WARREN-WHITESIDE.
MO...HEAT ADVISORY UNTIL 7 AM CDT SATURDAY FOR CLARK-SCOTLAND.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1145 AM MDT WED JUL 4 2012
.UPDATE...
ISSUED AT 857 AM MDT WED JUL 4 2012
CURRENT FORECAST LOOKS TO BE IN GOOD SHAPE SO WILL LEAVE AS IS.
LATEST MODELS STILL HAVE MARGINAL FIRE WEATHER CONDITIONS OVER THE
LEOTI TO HILL CITY AREAS THIS AFTERNOON WITH THE WIND SPEEDS BEING
THE MAIN QUESTION. MAX WIND GUST FROM THE NAM SHOWS WINDS GUSTING
TO 25 MPH WHILE THE HRRR SHOWS GUSTS UP TO 35 MPH FOR A BRIEF
TIME. HESITATE TO JUMP ON THE HRRR...WHICH HAS INCREASED WINDS
SINCE THE PREVIOUS RUN...OVER THE NAM WHICH IS HANDLING THE
OVERALL WEATHER PATTERN QUITE WELL SO FAR. WILL CONTINUE TO
MONITOR THE FIRE WEATHER CONDITIONS OUT EAST IN THE EVENT A
HIGHLITE IS NEEDED.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 442 AM MDT WED JUL 4 2012
FORECAST CONCERNS THROUGH WILL CHANCE OF PRECIPITATION/HEAVY
RAINFALL THREAT THIS AFTERNOON AND EVENING AND HOW HOT TO KEEP
IT/FIRE WEATHER CONCERNS THROUGH FRIDAY. SATELLITE SHOWING A BROAD
TROUGH EXTENDING FROM THE NORTHERN PACIFIC INTO THE PACIFIC NORTHWEST
AND WESTERN CANADA WITH PERSISTENT/BROAD UPPER HIGH THAT ENCOMPASSES
MOST OF THE COUNTRY WITH ANOTHER TROUGH THE NORTHEAST PORTION OF THE
COUNTRY. A COUPLE OF PREFRONTAL TROUGHS NEAR THE AREA AS A COLD FRONT
APPROACHES FROM THE NORTHWEST.
MODELS DID FINE ON THE UPPER JET. THE MODELS WERE HAVING SOME
DIFFICULTY ON POSITION AND STRENGTH OF MID/UPPER RIDGE WITH THE
MODELS SHOWING A TENDENCY TO NOT BE QUITE STRONG ENOUGH. THE SREF...
UKMET AND CANADIAN WERE DOING A LITTLE BETTER IN THIS RESPECT. THE
NAM AND UKMET WERE DOING A LITTLE BETTER THAN THE OTHER MODELS ON
THE POSITION OF THE FRONT AND PREFRONTAL TROUGH NEAR OUR AREA. FOR
THE LOW LEVEL THERMAL FIELD...THE NAM AND UKMET FOLLOWED BY THE
SREF/CANADIAN WERE DOING A LITTLE BETTER THAN EVERYTHING ELSE. RECENT
TRENDS/BIASES SUPPORT THE NAM AS WELL. FOR THE PRECIPITATION THROUGH
THE EVENING...THE NAM AND SREF WERE DOING THE BEST WITH THE
ECMWF/CANADIAN TOO DRY AND THE GFS TOO WET.
TODAY/TONIGHT...MODELS SIMILAR IN BRINGING A BOUNDARY INTO THE
FORECAST AREA THIS AFTERNOON AND THIS EVENING. NAM HAS BEEN DOING
WELL RECENTLY IN REGARDS TO PRECIPITATION AND HIGH TEMPERATURES.
OTHER MODELS ARE IN GENERAL AGREEMENT IN AREA OF PRECIPITATION
ESPECIALLY THE ECMWF AND SREF. SREF IS SUPPORTIVE OF THE NAM ON THE
TEMPERATURE AND PRECIPITATION FORECAST.
AS A RESULT THERE LOOKS TO BE A GOOD CHANCE OF THUNDERSTORMS OVER
THE NORTHWEST HALF OF THE AREA AND THIS AREA MAY NEED TO BE ADJUSTED
DEPENDING ON WHERE THE INCOMING FRONT STALLS OUT AT. HIGH
INSTABILITY AND PRECIPITABLE WATER NEAR 1.5 INCHES ESPECIALLY OVER
THE NORTHWEST HALF. STORM MOVEMENT IS NEAR 10 KNOTS AND NEARLY
PARALLEL TO A SLIGHT CROSS COMPONENT ACROSS THE FRONT. THERE WILL
BE A TUG OF WAR BETWEEN THE COLD POOL PRODUCED BY THE STORMS AND
LOW LEVEL INFLOW ACROSS THE FRONT ESPECIALLY TONIGHT AS THE LOW
LEVEL JET DEVELOPS. COULD END UP HAVING THUNDERSTORMS REMAINING
OVER THE SAME AREA IN THIS AREA. AS A RESULT...HAVE INCLUDED HEAVY
RAINFALL IN THIS AREA THIS AFTERNOON AND EVENING.
MODEL 850/2 METER CHANGED LITTLE FROM YESTERDAY SO KEPT MAXES ABOUT
THE SAME. IF MORE CLOUD COVER DEVELOPS SOONER...THIS COULD HOLD DOWN
THE MAXES IN THE WEST. BEST COMBINATION OF HIGHEST WINDS/LOWEST
RELATIVE HUMIDITIES WILL BE IN THE EASTERN PORTION OF THE AREA. IT
LOOKS MARGINAL AT THIS TIME AND BELIEVE MAY NOT BE 3 HOURS WORTH OF
CRITERIA. WILL CONTINUE TO MONITOR THIS AND BRIEF THE DAY SHIFT
ABOUT THIS.
THURSDAY...MID/UPPER LEVEL RIDGE BUILDS IN FROM THE EAST. THIS
PUSHES BETTER DEEP FOCUS OF LIFT AND MOISTURE FURTHER WEST PLUS MID
LEVEL TEMPERATURES WILL RISE EVEN MORE. ALSO STORM MOVEMENTS WILL
CONTINUE TO BE SLOW AND MORE SOUTH TO NORTH WHICH SHOULD LIMIT
EASTWARD PROGRESSION OF STORMS. LOW LEVEL THERMAL FIELD CHANGES
LITTLE AND CLOUD COVER COULD BE THE ONLY THING THAT MAY CAUSE ANY
COOL DOWN BUT IT DOES NOT LOOK LIKE IT RIGHT NOW. AGAIN MARGINAL
FIRE WEATHER CONDITIONS WILL OCCUR IN THE EASTERN PORTION OF THE
FORECAST AREA.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 442 AM MDT WED JUL 4 2012
THURSDAY NIGHT...PER THE REASONING ABOVE LOW POPS WILL BE CONFINED TO
THE FAR WEST.
FRIDAY/FRIDAY NIGHT...HIGHER HEIGHTS CONTINUE TO BUILD INTO THE
AREA. THIS SHOULD AGAIN CONFINE THE BEST MOISTURE AND LIFT TO THE
WEST OF THE AREA. THE FAR WESTERN PORTION OF THE AREA SHOULD AGAIN
HAVE A LOW CHANCE OF PRECIPITATION WITH LITTLE EASTWARD PROGRESSION
EXPECTED DUE TO SLOW SOUTH TO NORTH MOVEMENT OF STORMS EXPECTED. LOW
LEVEL THERMAL FIELD REMAINS NEARLY THE SAME AGAIN AND KEPT A
PERSISTENCE FORECAST. MARGINAL CRITICAL FIRE WEATHER CONDITIONS
WILL AGAIN EXIST...MAINLY IN THE EASTERN PORTION OF THE AREA.
SATURDAY THROUGH TUESDAY...FORECAST PROBLEMS WILL BE HOW HOT TO MAKE
IT EARLY ON AND HOW COOL/WET TO MAKE IT THE BEGINNING OF NEXT AS
MODELS INDICATING A PATTERN CHANGE DURING THAT TIME. MID/UPPER RIDGE
STARTS OUT CENTERED TO OUR EAST THEN STARTS ELONGATING/RETROGRESSING
ON SUNDAY, RETROGRESSION AND AMPLIFICATION CONTINUE THROUGH THE END
OF THIS PERIOD WHICH LEAVES THE AREA OPEN TO THE MOST SIGNIFICANT
NORTHWEST FLOW ALOFT THIS SEASON. OVERALL THE DETERMINISTIC MODELS
ARE IN GENERAL/GOOD AGREEMENT WITH THIS SCENARIO. THE ENSEMBLES NOT
ONLY SUPPORT THE PATTERN CHANGE BUT SUPPORT THE FURTHER WEST
AMPLIFICATION/POSITION OF THIS RIDGE WHICH IS MORE IN LINE WITH THE
CANADIAN AND ECMWF. THE GFS SEEMS A LITTLE TOO FAR EAST.
KEPT THE CRH_INIT GRIDS THROUGH THE PERIOD FOR THE FOLLOWING
REASONS. EARLY ON WITH THE RIDGE NEAR OR TO THE EAST OF US...MID
LEVEL TEMPERATURES DO NOT APPEAR HIGH ENOUGH TO INHIBIT CONVECTION.
PLUS A MEANDERING FRONTAL BOUNDARY WILL BE NEAR OR OVER THE AREA.
AFTER THAT AREA WILL BE UNDER THAT NORTHWEST FLOW ALOFT WITH SUBTLE
SHORTWAVE TROUGHS...WHICH IS USUALLY WET/ACTIVE...WITH THE AREA
HAVING THE FRONT DRAPED ON TOP OF US OR WITH US IN A POST FRONTAL
UPSLOPE REGIME. CONSIDERING THAT THESE SUBTLE WAVES AND ANY MESOSCALE
INFLUENCE IMPOSSIBLE TO DIAGNOSE AT THIS TIME RANGE...FELT
COMFORTABLE IN LEAVING THOSE POPS. ALSO IT LOOKS MORE POSSIBLE NOW
THAT AREA COULD COOL INTO THE 80S BY THE END OF THE PERIOD WHICH IS
REASONABLE CONSIDERING THE PATTERN.
THANKS TO ALL THAT COLLABORATED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1128 AM MDT WED JUL 4 2012
VFR CONDITIONS ARE FORECAST FOR THE 18Z TAFS. MAIN ISSUE WITH THE
TAFS WILL BE THE START TIME OF THUNDERSTORMS THIS AFTERNOON AND
HOW LONG THEY PERSIST THROUGH THE NIGHT. LATEST NAM SEEMS TO HAVE
A GOOD HANDLE ON THE FRONTAL TIMING...SO HAVE TRENDED STRONGLY
TOWARD IT. WITH THE HIGH CLOUD BASES...ANY STORMS THAT FORM WILL
BE CAPABLE OF PRODUCING STRONG TO SEVERE WIND GUSTS.
CURRENT SURFACE ANALYSIS SHOWS THE FRONT NEAR K2V5.
THE FRONT WILL BECOME NEARLY STATIONARY DURING THE LATE
AFTERNOON...LYING NEAR KSYF. AM ANTICIPATING THUNDERSTORMS TO
INITIATE NEAR THE FRONT DURING THE EARLY AFTERNOON...WITH COVERAGE
EXPANDING INTO THE EVENING. AM THINKING THE BEST TIME PERIOD FOR
KGLD TO SEE T-STORMS WILL BE DURING THE EARLY EVENING AS THE NOSE
OF THE LOW LEVEL JET MOVES OVER THE SITE. HOWEVER...WITH THE FRONT
NORTH OF KGLD...THE SITE MAY REMAIN JUST SOUTH OF THE STORM
ACTIVITY. AS THE FRONT MOVES NORTH DURING THE NIGHT THE STORM
COVERAGE WILL DIMINISH FOR KGLD.
KMCK FOLLOWS A SIMILAR PATTERN FOR STORM COVERAGE...WITH THE BEST
SHOT BEING DURING THE EVENING. THE FRONT REMAINS JUST EAST OF KMCK THROUGH
THE EVENING SO THE SITE MAY SEE STORMS LONGER THAN KGLD. AS THE
FRONT MOVES NORTH OVERNIGHT STORM COVERAGE SHOULD DECLINE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...007/BULLER
LONG TERM...BULLER
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1217 PM CDT WED JUL 4 2012
...UPDATED AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 231 AM CDT WED JUL 4 2012
THE ANALYSIS OF THE 04/00Z UPPER AIR ANALYSIS SHOWED SLIGHT CHANGES
FROM YESTERDAY, WITH A 90 TO 110 KNOT EASTERLY JET ZIPPING THROUGH
OREGON AND TURNING NORTHEAST INTO NORTHERN SASKATCHEWAN, THEN
TURNING SOUTHEASTWARD OVER NORTHERN MANITOBA AND NORTHERN ONTARIO.
A SOUTHERLY JET IN THE 90 KNOT RANGE WAS FROM EASTERN QUEBEC TO A
POINT ABOUT 125 MILES OFF THE EASTERN NORTH CAROLINA COAST. WINDS
OVER WESTERN KANSAS AT THE 250MB LEVEL WERE LIGHT AND GENERALLY
UNDER 10 KNOTS. AT THE 500MB LEVEL, A STRONG HIGH PRESSURE RIDGE
RAN NORTHEAST FROM NORTHERN NEW MEXICO THROUGH NORTHWESTERN KANSAS
AND THEN CONTINUED NORTHWARD INTO WESTERN ONTARIO. A LOW PRESSURE
SHORT WAVE HAD FORMED OVER WESTERN ALBERTA SINCE YESTERDAY, WITH A
TROUGH TRAILING SOUTHWESTWARD INTO NORTHERN WASHINGTON. THE 700MB
CHART DISPLAYED A SIMILAR HIGH PRESSURE RIDGE AS DID THE 500MB
CHART, AND ALSO HAD A CUT OFF LOW OVER NORTH CENTRAL ALBERTA. THE
700MB TEMPERATURE AT DDC WAS 11C DEGREES, THE SAME AS IT HAS BEEN
THE PAST 3 DAYS. AT THE 850MB LEVEL, A LARGE HIGH PRESSURE SYSTEM
MAINTAINED ITSELF OVER THE SOUTHEASTERN UNITED STATES, WHILE LOW
PRESSURE TROUGHS WERE EVIDENT BOTH WEST AND EAST OF THE COLORADO
ROCKIES. THE 850MB TEMPERATURE AT DDC WAS 27C DEGREES, EXACTLY
WHAT IT WAS 24 HOURS AGO. THE MAIN DIFFERENCE NOTICEABLE FROM
YESTERDAY IS A LITTLE MORE MOISTURE IN THE LOWER LAYERS, WITH THE
DDC 850MB DEW POINT AT +11C.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 231 AM CDT WED JUL 4 2012
AN OUTFLOW BOUNDARY FROM CONVECTION EARLIER IN COLORADO COLLIDED
WITH A LITTLE MOISTURE FLOWING NORTH FROM OKLAHOMA TO TRIGGER A FEW
WIDELY SCATTERED SHOWERS IN WESTERN KANSAS ABOUT 04-05Z. BOTH THE
HRRR AND RUC MODELS BRING THIS PRECIPITATION A LITTLE FARTHER EAST
INTO OUR CWA, INCLUDING DEVELOPING A FEW SHOWERS IN OUR SOUTH
CENTRAL AND SOUTHEAST ZONES TOWARD 12Z. I HAVE PLACED LOW 16 PERCENT
POPS IN OUR WESTERN 1/3RD AND SOUTHERN TIER OF COUNTIES THROUGH
14Z. RECENT RADAR TRENDS AS OF 07Z HAD THE SHOWER ACTIVITY ON A
DISSIPATING AND DOWNWARD TREND. WENT WITH WIDELY SCATTERED SHOWERS
AND ISOLATED THUNDERSTORMS, AND VERY LOW QPF AMOUNTS IN THE 0.01
RANGE. DO NOT THINK ANY ONE LOCATION WILL SEE ANY SIGNIFICANT
PRECIPITATION, AS THE MID LAYERS ARE REALLY DRY. THE LEE SIDE
TROUGH WILL DEEPEN QUICKLY THIS MORNING OVER EASTERN COLORADO,
WITH OUR LIGHT SOUTHEAST WINDS THEN SHIFTING SOUTHWEST AND
INCREASING IN THE 18G28MPH RANGE FOR THE REST OF THIS 4TH OF JULY
HOLIDAY. I AM SURE THE AREA FIREWORKS AND FIRE DEPARTMENTS WILL
NOT LIKE THIS WIND FORECAST, BUT THE A GOOD FORECAST IS BETTER
THAN A WISHFUL FORECAST. IT WILL AGAIN BE HOT WITH MAX
TEMPERATURES FROM 98F IN ELKHART TO 103F NEAR HAYS, VERY CLOSE TO
WHAT THE MAX TEMPERATURES WERE TUESDAY.
MOSTLY CLEAR TO CLEAR SKIES ARE EXPECTED TONIGHT, WITH SOUTH TO
SOUTHWEST WINDS STAYING UP IN THE 15G20 MPH RANGE THROUGH 03Z, THEN
THE WINDS SHOULD FALL TO AROUND 10 MPH BY 12Z. TEMPERATURES WILL NOT
FALL QUICKLY DUE TO SUSTAINED WINDS, BUT BY THURSDAY MORNING SHOULD BE
IN THE 69F DEGREES (EXTREME SOUTHWEST AROUND ELKHART) TO AROUND 74F
DEGREES (NORTHEAST NEAR HAYS) RANGE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 310 AM CDT WED JUL 4 2012
HOT AND DRY WEATHER WILL CONTINUE THURSDAY THROUGH SUNDAY AS A 500 HPA
RIDGE RETROGRADES ACROSS THE CENTRAL PLAINS. EXPECT HIGHS IN THE UPPER
90S TO AROUND 100 DEG F. LOWS WILL BE IN THE LOWER 70S DEG F.
THE SYNOPTIC PATTERN CHANGES MONDAY AS THE UPPER RIDGE MOVES FAR WEST
ENOUGH AND COLD FRONT SLOWLY SINKS SOUTHWARD CLOSER TO KANSAS. THE MODELS
ARE STILL INDICATING THUNDERSTORMS ACROSS THE REGION. AS A RESULT, WILL
CARRY SLIGHT TO CHANCE POPS IN THE GRIDS NEXT WEEK. HAVE ALSO GONE WITH
LOWER MAX/MINS AS A RESULT OF INCREASED CLOUD COVER. TEMPERATURES MIGHT
ACTUALLY BE SLIGHTLY BELOW NORMAL NEXT WEEK. WE SHALL SEE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1215 PM CDT WED JUL 4 2012
VFR CONDITIONS WILL CONTINUE AT THE TAF SITES THROUGH THIS PERIOD.
THROUGH THE PEAK HEATING HOURS THIS AFTERNOON LOOK FOR SOUTH WINDS
GUSTING TO AROUND 25 TO 30 KNOTS AT TIMES ALONG WITH SOME CUMULUS
CLOUDS AT AROUND NINE THOUSAND FEET ABOVE GROUND LEVEL. THE WINDS
WILL DIMINISH TOWARD SUNSET.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 100 72 100 73 / 0 0 0 0
GCK 100 72 99 72 / 10 10 0 0
EHA 98 71 96 70 / 10 10 0 0
LBL 99 71 98 71 / 0 0 0 0
HYS 103 75 101 74 / 0 0 0 0
P28 101 74 101 74 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURKE
SHORT TERM...BURKE
LONG TERM...SUGDEN
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS GOODLAND KS
909 AM MDT WED JUL 4 2012
.UPDATE...
ISSUED AT 857 AM MDT WED JUL 4 2012
CURRENT FORECAST LOOKS TO BE IN GOOD SHAPE SO WILL LEAVE AS IS.
LATEST MODELS STILL HAVE MARGINAL FIRE WEATHER CONDITIONS OVER THE
LEOTI TO HILL CITY AREAS THIS AFTERNOON WITH THE WIND SPEEDS BEING
THE MAIN QUESTION. MAX WIND GUST FROM THE NAM SHOWS WINDS GUSTING
TO 25 MPH WHILE THE HRRR SHOWS GUSTS UP TO 35 MPH FOR A BRIEF
TIME. HESITATE TO JUMP ON THE HRRR...WHICH HAS INCREASED WINDS
SINCE THE PREVIOUS RUN...OVER THE NAM WHICH IS HANDLING THE
OVERALL WEATHER PATTERN QUITE WELL SO FAR. WILL CONTINUE TO
MONITOR THE FIRE WEATHER CONDITIONS OUT EAST IN THE EVENT A
HIGHLITE IS NEEDED.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 442 AM MDT WED JUL 4 2012
FORECAST CONCERNS THROUGH WILL CHANCE OF PRECIPITATION/HEAVY
RAINFALL THREAT THIS AFTERNOON AND EVENING AND HOW HOT TO KEEP
IT/FIRE WEATHER CONCERNS THROUGH FRIDAY. SATELLITE SHOWING A BROAD
TROUGH EXTENDING FROM THE NORTHERN PACIFIC INTO THE PACIFIC NORTHWEST
AND WESTERN CANADA WITH PERSISTENT/BROAD UPPER HIGH THAT ENCOMPASSES
MOST OF THE COUNTRY WITH ANOTHER TROUGH THE NORTHEAST PORTION OF THE
COUNTRY. A COUPLE OF PREFRONTAL TROUGHS NEAR THE AREA AS A COLD FRONT
APPROACHES FROM THE NORTHWEST.
MODELS DID FINE ON THE UPPER JET. THE MODELS WERE HAVING SOME
DIFFICULTY ON POSITION AND STRENGTH OF MID/UPPER RIDGE WITH THE
MODELS SHOWING A TENDENCY TO NOT BE QUITE STRONG ENOUGH. THE SREF...
UKMET AND CANADIAN WERE DOING A LITTLE BETTER IN THIS RESPECT. THE
NAM AND UKMET WERE DOING A LITTLE BETTER THAN THE OTHER MODELS ON
THE POSITION OF THE FRONT AND PREFRONTAL TROUGH NEAR OUR AREA. FOR
THE LOW LEVEL THERMAL FIELD...THE NAM AND UKMET FOLLOWED BY THE
SREF/CANADIAN WERE DOING A LITTLE BETTER THAN EVERYTHING ELSE. RECENT
TRENDS/BIASES SUPPORT THE NAM AS WELL. FOR THE PRECIPITATION THROUGH
THE EVENING...THE NAM AND SREF WERE DOING THE BEST WITH THE
ECMWF/CANADIAN TOO DRY AND THE GFS TOO WET.
TODAY/TONIGHT...MODELS SIMILAR IN BRINGING A BOUNDARY INTO THE
FORECAST AREA THIS AFTERNOON AND THIS EVENING. NAM HAS BEEN DOING
WELL RECENTLY IN REGARDS TO PRECIPITATION AND HIGH TEMPERATURES.
OTHER MODELS ARE IN GENERAL AGREEMENT IN AREA OF PRECIPITATION
ESPECIALLY THE ECMWF AND SREF. SREF IS SUPPORTIVE OF THE NAM ON THE
TEMPERATURE AND PRECIPITATION FORECAST.
AS A RESULT THERE LOOKS TO BE A GOOD CHANCE OF THUNDERSTORMS OVER
THE NORTHWEST HALF OF THE AREA AND THIS AREA MAY NEED TO BE ADJUSTED
DEPENDING ON WHERE THE INCOMING FRONT STALLS OUT AT. HIGH
INSTABILITY AND PRECIPITABLE WATER NEAR 1.5 INCHES ESPECIALLY OVER
THE NORTHWEST HALF. STORM MOVEMENT IS NEAR 10 KNOTS AND NEARLY
PARALLEL TO A SLIGHT CROSS COMPONENT ACROSS THE FRONT. THERE WILL
BE A TUG OF WAR BETWEEN THE COLD POOL PRODUCED BY THE STORMS AND
LOW LEVEL INFLOW ACROSS THE FRONT ESPECIALLY TONIGHT AS THE LOW
LEVEL JET DEVELOPS. COULD END UP HAVING THUNDERSTORMS REMAINING
OVER THE SAME AREA IN THIS AREA. AS A RESULT...HAVE INCLUDED HEAVY
RAINFALL IN THIS AREA THIS AFTERNOON AND EVENING.
MODEL 850/2 METER CHANGED LITTLE FROM YESTERDAY SO KEPT MAXES ABOUT
THE SAME. IF MORE CLOUD COVER DEVELOPS SOONER...THIS COULD HOLD DOWN
THE MAXES IN THE WEST. BEST COMBINATION OF HIGHEST WINDS/LOWEST
RELATIVE HUMIDITIES WILL BE IN THE EASTERN PORTION OF THE AREA. IT
LOOKS MARGINAL AT THIS TIME AND BELIEVE MAY NOT BE 3 HOURS WORTH OF
CRITERIA. WILL CONTINUE TO MONITOR THIS AND BRIEF THE DAY SHIFT
ABOUT THIS.
THURSDAY...MID/UPPER LEVEL RIDGE BUILDS IN FROM THE EAST. THIS
PUSHES BETTER DEEP FOCUS OF LIFT AND MOISTURE FURTHER WEST PLUS MID
LEVEL TEMPERATURES WILL RISE EVEN MORE. ALSO STORM MOVEMENTS WILL
CONTINUE TO BE SLOW AND MORE SOUTH TO NORTH WHICH SHOULD LIMIT
EASTWARD PROGRESSION OF STORMS. LOW LEVEL THERMAL FIELD CHANGES
LITTLE AND CLOUD COVER COULD BE THE ONLY THING THAT MAY CAUSE ANY
COOL DOWN BUT IT DOES NOT LOOK LIKE IT RIGHT NOW. AGAIN MARGINAL
FIRE WEATHER CONDITIONS WILL OCCUR IN THE EASTERN PORTION OF THE
FORECAST AREA.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 442 AM MDT WED JUL 4 2012
THURSDAY NIGHT...PER THE REASONING ABOVE LOW POPS WILL BE CONFINED TO
THE FAR WEST.
FRIDAY/FRIDAY NIGHT...HIGHER HEIGHTS CONTINUE TO BUILD INTO THE
AREA. THIS SHOULD AGAIN CONFINE THE BEST MOISTURE AND LIFT TO THE
WEST OF THE AREA. THE FAR WESTERN PORTION OF THE AREA SHOULD AGAIN
HAVE A LOW CHANCE OF PRECIPITATION WITH LITTLE EASTWARD PROGRESSION
EXPECTED DUE TO SLOW SOUTH TO NORTH MOVEMENT OF STORMS EXPECTED. LOW
LEVEL THERMAL FIELD REMAINS NEARLY THE SAME AGAIN AND KEPT A
PERSISTENCE FORECAST. MARGINAL CRITICAL FIRE WEATHER CONDITIONS
WILL AGAIN EXIST...MAINLY IN THE EASTERN PORTION OF THE AREA.
SATURDAY THROUGH TUESDAY...FORECAST PROBLEMS WILL BE HOW HOT TO MAKE
IT EARLY ON AND HOW COOL/WET TO MAKE IT THE BEGINNING OF NEXT AS
MODELS INDICATING A PATTERN CHANGE DURING THAT TIME. MID/UPPER RIDGE
STARTS OUT CENTERED TO OUR EAST THEN STARTS ELONGATING/RETROGRESSING
ON SUNDAY, RETROGRESSION AND AMPLIFICATION CONTINUE THROUGH THE END
OF THIS PERIOD WHICH LEAVES THE AREA OPEN TO THE MOST SIGNIFICANT
NORTHWEST FLOW ALOFT THIS SEASON. OVERALL THE DETERMINISTIC MODELS
ARE IN GENERAL/GOOD AGREEMENT WITH THIS SCENARIO. THE ENSEMBLES NOT
ONLY SUPPORT THE PATTERN CHANGE BUT SUPPORT THE FURTHER WEST
AMPLIFICATION/POSITION OF THIS RIDGE WHICH IS MORE IN LINE WITH THE
CANADIAN AND ECMWF. THE GFS SEEMS A LITTLE TOO FAR EAST.
KEPT THE CRH_INIT GRIDS THROUGH THE PERIOD FOR THE FOLLOWING
REASONS. EARLY ON WITH THE RIDGE NEAR OR TO THE EAST OF US...MID
LEVEL TEMPERATURES DO NOT APPEAR HIGH ENOUGH TO INHIBIT CONVECTION.
PLUS A MEANDERING FRONTAL BOUNDARY WILL BE NEAR OR OVER THE AREA.
AFTER THAT AREA WILL BE UNDER THAT NORTHWEST FLOW ALOFT WITH SUBTLE
SHORTWAVE TROUGHS...WHICH IS USUALLY WET/ACTIVE...WITH THE AREA
HAVING THE FRONT DRAPED ON TOP OF US OR WITH US IN A POST FRONTAL
UPSLOPE REGIME. CONSIDERING THAT THESE SUBTLE WAVES AND ANY MESOSCALE
INFLUENCE IMPOSSIBLE TO DIAGNOSE AT THIS TIME RANGE...FELT
COMFORTABLE IN LEAVING THOSE POPS. ALSO IT LOOKS MORE POSSIBLE NOW
THAT AREA COULD COOL INTO THE 80S BY THE END OF THE PERIOD WHICH IS
REASONABLE CONSIDERING THE PATTERN.
THANKS TO ALL THAT COLLABORATED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 542 AM MDT WED JUL 4 2012
A COLD FRONT WILL SETTLE OVER THE AREA THIS AFTERNOON INTO THIS
EVENING. SOME DIFFERENCE IN MODEL OUTPUT AS TO WHERE THIS FRONT
FINALLY ENDS UP. BUT LOOKS LIKE IT WILL BE NEAR ENOUGH TO BOTH
KGLD AND KMCK TO BRING A CHANCE OF THUNDERSTORMS TO BOTH SITES.
ENOUGH CONFIDENCE TO PUT VCTS AT BOTH SITES LATER THIS AFTERNOON
WITH DEFINITE THUNDERSTORMS MENTIONED BEGINNING IN THE EVENING.
COULD DEFINITELY SEEM SOME VISIBILITY RESTRICTIONS IF A STRONG
THUNDERSTORMS ENDS UP OVER EACH SITE BUT SINCE THIS FALLS IN THE
LATER HALF OF THE PERIOD CHOSE TO NOT MENTION ANY LOWERING OF THE
VISIBILITY. UPCOMING SHIFTS WILL HAVE TO REFINE THAT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...007/BULLER
LONG TERM...BULLER
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
600 AM CDT WED JUL 4 2012
...UPDATE TO AVIATION FOR 12Z TAFS...
.SYNOPSIS...
ISSUED AT 231 AM CDT WED JUL 4 2012
THE ANALYSIS OF THE 04/00Z UPPER AIR ANALYSIS SHOWED SLIGHT CHANGES
FROM YESTERDAY, WITH A 90 TO 110 KNOT EASTERLY JET ZIPPING THROUGH
OREGON AND TURNING NORTHEAST INTO NORTHERN SASKATCHEWAN, THEN
TURNING SOUTHEASTWARD OVER NORTHERN MANITOBA AND NORTHERN ONTARIO.
A SOUTHERLY JET IN THE 90 KNOT RANGE WAS FROM EASTERN QUEBEC TO A
POINT ABOUT 125 MILES OFF THE EASTERN NORTH CAROLINA COAST. WINDS
OVER WESTERN KANSAS AT THE 250MB LEVEL WERE LIGHT AND GENERALLY
UNDER 10 KNOTS. AT THE 500MB LEVEL, A STRONG HIGH PRESSURE RIDGE
RAN NORTHEAST FROM NORTHERN NEW MEXICO THROUGH NORTHWESTERN KANSAS
AND THEN CONTINUED NORTHWARD INTO WESTERN ONTARIO. A LOW PRESSURE
SHORT WAVE HAD FORMED OVER WESTERN ALBERTA SINCE YESTERDAY, WITH A
TROUGH TRAILING SOUTHWESTWARD INTO NORTHERN WASHINGTON. THE 700MB
CHART DISPLAYED A SIMILAR HIGH PRESSURE RIDGE AS DID THE 500MB
CHART, AND ALSO HAD A CUT OFF LOW OVER NORTH CENTRAL ALBERTA. THE
700MB TEMPERATURE AT DDC WAS 11C DEGREES, THE SAME AS IT HAS BEEN
THE PAST 3 DAYS. AT THE 850MB LEVEL, A LARGE HIGH PRESSURE SYSTEM
MAINTAINED ITSELF OVER THE SOUTHEASTERN UNITED STATES, WHILE LOW
PRESSURE TROUGHS WERE EVIDENT BOTH WEST AND EAST OF THE COLORADO
ROCKIES. THE 850MB TEMPERATURE AT DDC WAS 27C DEGREES, EXACTLY
WHAT IT WAS 24 HOURS AGO. THE MAIN DIFFERENCE NOTICEABLE FROM
YESTERDAY IS A LITTLE MORE MOISTURE IN THE LOWER LAYERS, WITH THE
DDC 850MB DEW POINT AT +11C.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 231 AM CDT WED JUL 4 2012
AN OUTFLOW BOUNDARY FROM CONVECTION EARLIER IN COLORADO COLLIDED
WITH A LITTLE MOISTURE FLOWING NORTH FROM OKLAHOMA TO TRIGGER A FEW
WIDELY SCATTERED SHOWERS IN WESTERN KANSAS ABOUT 04-05Z. BOTH THE
HRRR AND RUC MODELS BRING THIS PRECIPITATION A LITTLE FARTHER EAST
INTO OUR CWA, INCLUDING DEVELOPING A FEW SHOWERS IN OUR SOUTH
CENTRAL AND SOUTHEAST ZONES TOWARD 12Z. I HAVE PLACED LOW 16 PERCENT
POPS IN OUR WESTERN 1/3RD AND SOUTHERN TIER OF COUNTIES THROUGH
14Z. RECENT RADAR TRENDS AS OF 07Z HAD THE SHOWER ACTIVITY ON A
DISSIPATING AND DOWNWARD TREND. WENT WITH WIDELY SCATTERED SHOWERS
AND ISOLATED THUNDERSTORMS, AND VERY LOW QPF AMOUNTS IN THE 0.01
RANGE. DO NOT THINK ANY ONE LOCATION WILL SEE ANY SIGNIFICANT
PRECIPITATION, AS THE MID LAYERS ARE REALLY DRY. THE LEE SIDE
TROUGH WILL DEEPEN QUICKLY THIS MORNING OVER EASTERN COLORADO,
WITH OUR LIGHT SOUTHEAST WINDS THEN SHIFTING SOUTHWEST AND
INCREASING IN THE 18G28MPH RANGE FOR THE REST OF THIS 4TH OF JULY
HOLIDAY. I AM SURE THE AREA FIREWORKS AND FIRE DEPARTMENTS WILL
NOT LIKE THIS WIND FORECAST, BUT THE A GOOD FORECAST IS BETTER
THAN A WISHFUL FORECAST. IT WILL AGAIN BE HOT WITH MAX
TEMPERATURES FROM 98F IN ELKHART TO 103F NEAR HAYS, VERY CLOSE TO
WHAT THE MAX TEMPERATURES WERE TUESDAY.
MOSTLY CLEAR TO CLEAR SKIES ARE EXPECTED TONIGHT, WITH SOUTH TO
SOUTHWEST WINDS STAYING UP IN THE 15G20 MPH RANGE THROUGH 03Z, THEN
THE WINDS SHOULD FALL TO AROUND 10 MPH BY 12Z. TEMPERATURES WILL NOT
FALL QUICKLY DUE TO SUSTAINED WINDS, BUT BY THURSDAY MORNING SHOULD BE
IN THE 69F DEGREES (XTRM SOUTHWEST AROUND ELKHART) TO AROUND 74F
DEGREES (NORTHEAST NEAR HAYS) RANGE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 310 AM CDT WED JUL 4 2012
HOT AND DRY WEATHER WILL CONTINUE THURSDAY THROUGH SUNDAY AS A 500 HPA
RIDGE RETROGRADES ACROSS THE CENTRAL PLAINS. EXPECT HIGHS IN THE UPPER
90S TO AROUND 100 DEG F. LOWS WILL BE IN THE LOWER 70S DEG F.
THE SYNOPTIC PATTERN CHANGES MONDAY AS THE UPPER RIDGE MOVES FAR WEST
ENOUGH AND COLD FRONT SLOWLY SINKS SOUTHWARD CLOSER TO KANSAS. THE MODELS
ARE STILL INDICATING THUNDERSTORMS ACROSS THE REGION. AS A RESULT, WILL
CARRY SLIGHT TO CHANCE POPS IN THE GRIDS NEXT WEEK. HAVE ALSO GONE WITH
LOWER MAX/MINS AS A RESULT OF INCREASED CLOUD COVER. TEMPERATURES MIGHT
ACTUALLY BE SLIGHTLY BELOW NORMAL NEXT WEEK. WE SHALL SEE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 600 AM CDT WED JUL 4 2012
VFR CIGS EXPECTED THROUGH PERIOD. WINDS WILL BE S 15-20 KT WITH GUSTS
TO 25-30 KT BETWEEN 15-02Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 100 72 100 73 / 0 0 0 0
GCK 100 72 99 72 / 20 10 0 0
EHA 98 71 96 70 / 20 10 0 0
LBL 99 71 98 71 / 20 0 0 0
HYS 103 75 101 74 / 0 0 0 0
P28 101 74 101 74 / 20 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURKE
SHORT TERM...BURKE
LONG TERM...SUGDEN
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
310 AM CDT WED JUL 4 2012
...UPDATE TO LONG TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 231 AM CDT WED JUL 4 2012
THE ANALYSIS OF THE 04/00Z UPPER AIR ANALYSIS SHOWED SLIGHT CHANGES
FROM YESTERDAY, WITH A 90 TO 110 KNOT EASTERLY JET ZIPPING THROUGH
OREGON AND TURNING NORTHEAST INTO NORTHERN SASKATCHEWAN, THEN
TURNING SOUTHEASTWARD OVER NORTHERN MANITOBA AND NORTHERN ONTARIO.
A SOUTHERLY JET IN THE 90 KNOT RANGE WAS FROM EASTERN QUEBEC TO A
POINT ABOUT 125 MILES OFF THE EASTERN NORTH CAROLINA COAST. WINDS
OVER WESTERN KANSAS AT THE 250MB LEVEL WERE LIGHT AND GENERALLY
UNDER 10 KNOTS. AT THE 500MB LEVEL, A STRONG HIGH PRESSURE RIDGE
RAN NORTHEAST FROM NORTHERN NEW MEXICO THROUGH NORTHWESTERN KANSAS
AND THEN CONTINUED NORTHWARD INTO WESTERN ONTARIO. A LOW PRESSURE
SHORT WAVE HAD FORMED OVER WESTERN ALBERTA SINCE YESTERDAY, WITH A
TROUGH TRAILING SOUTHWESTWARD INTO NORTHERN WASHINGTON. THE 700MB
CHART DISPLAYED A SIMILAR HIGH PRESSURE RIDGE AS DID THE 500MB
CHART, AND ALSO HAD A CUT OFF LOW OVER NORTH CENTRAL ALBERTA. THE
700MB TEMPERATURE AT DDC WAS 11C DEGREES, THE SAME AS IT HAS BEEN
THE PAST 3 DAYS. AT THE 850MB LEVEL, A LARGE HIGH PRESSURE SYSTEM
MAINTAINED ITSELF OVER THE SOUTHEASTERN UNITED STATES, WHILE LOW
PRESSURE TROUGHS WERE EVIDENT BOTH WEST AND EAST OF THE COLORADO
ROCKIES. THE 850MB TEMPERATURE AT DDC WAS 27C DEGREES, EXACTLY
WHAT IT WAS 24 HOURS AGO. THE MAIN DIFFERENCE NOTICEABLE FROM
YESTERDAY IS A LITTLE MORE MOISTURE IN THE LOWER LAYERS, WITH THE
DDC 850MB DEW POINT AT +11C.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 231 AM CDT WED JUL 4 2012
AN OUTFLOW BOUNDARY FROM CONVECTION EARLIER IN COLORADO COLLIDED
WITH A LITTLE MOISTURE FLOWING NORTH FROM OKLAHOMA TO TRIGGER A FEW
WIDELY SCATTERED SHOWERS IN WESTERN KANSAS ABOUT 04-05Z. BOTH THE
HRRR AND RUC MODELS BRING THIS PRECIPITATION A LITTLE FARTHER EAST
INTO OUR CWA, INCLUDING DEVELOPING A FEW SHOWERS IN OUR SOUTH
CENTRAL AND SOUTHEAST ZONES TOWARD 12Z. I HAVE PLACED LOW 16 PERCENT
POPS IN OUR WESTERN 1/3RD AND SOUTHERN TIER OF COUNTIES THROUGH
14Z. RECENT RADAR TRENDS AS OF 07Z HAD THE SHOWER ACTIVITY ON A
DISSIPATING AND DOWNWARD TREND. WENT WITH WIDELY SCATTERED SHOWERS
AND ISOLATED THUNDERSTORMS, AND VERY LOW QPF AMOUNTS IN THE 0.01
RANGE. DO NOT THINK ANY ONE LOCATION WILL SEE ANY SIGNIFICANT
PRECIPITATION, AS THE MID LAYERS ARE REALLY DRY. THE LEE SIDE
TROUGH WILL DEEPEN QUICKLY THIS MORNING OVER EASTERN COLORADO,
WITH OUR LIGHT SOUTHEAST WINDS THEN SHIFTING SOUTHWEST AND
INCREASING IN THE 18G28MPH RANGE FOR THE REST OF THIS 4TH OF JULY
HOLIDAY. I AM SURE THE AREA FIREWORKS AND FIRE DEPARTMENTS WILL
NOT LIKE THIS WIND FORECAST, BUT THE A GOOD FORECAST IS BETTER
THAN A WISHFUL FORECAST. IT WILL AGAIN BE HOT WITH MAX
TEMPERATURES FROM 98F IN ELKHART TO 103F NEAR HAYS, VERY CLOSE TO
WHAT THE MAX TEMPERATURES WERE TUESDAY.
MOSTLY CLEAR TO CLEAR SKIES ARE EXPECTED TONIGHT, WITH SOUTH TO
SOUTHWEST WINDS STAYING UP IN THE 15G20 MPH RANGE THROUGH 03Z, THEN
THE WINDS SHOULD FALL TO AROUND 10 MPH BY 12Z. TEMPERATURES WILL NOT
FALL QUICKLY DUE TO SUSTAINED WINDS, BUT BY THURSDAY MORNING SHOULD BE
IN THE 69F DEGREES (XTRM SOUTHWEST AROUND ELKHART) TO AROUND 74F
DEGREES (NORTHEAST NEAR HAYS) RANGE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 310 AM CDT WED JUL 4 2012
HOT AND DRY WEATHER WILL CONTINUE THURSDAY THROUGH SUNDAY AS A 500 HPA
RIDGE RETROGRADES ACROSS THE CENTRAL PLAINS. EXPECT HIGHS IN THE UPPER
90S TO AROUND 100 DEG F. LOWS WILL BE IN THE LOWER 70S DEG F.
THE SYNOPTIC PATTERN CHANGES MONDAY AS THE UPPER RIDGE MOVES FAR WEST
ENOUGH AND COLD FRONT SLOWLY SINKS SOUTHWARD CLOSER TO KANSAS. THE MODELS
ARE STILL INDICATING THUNDERSTORMS ACROSS THE REGION. AS A RESULT, WILL
CARRY SLIGHT TO CHANCE POPS IN THE GRIDS NEXT WEEK. HAVE ALSO GONE WITH
LOWER MAX/MINS AS A RESULT OF INCREASED CLOUD COVER. TEMPERATURES MIGHT
ACTUALLY BE SLIGHTLY BELOW NORMAL NEXT WEEK. WE SHALL SEE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1209 AM CDT WED JUL 4 2012
EXPECT CLEAR SKIES OVERNIGHT WITH JUST A FEW WIDELY SCATTERED
SHOWERS NEAR THE COLORADO BORDER THROUGH 10Z. WINDS TONIGHT WILL
BE SOUTHEAST AT AROUND 10 KNOTS, SWITCHING TO SOUTHWEST AND
INCREASING AFTER 15Z WEDNESDAY INTO THE 17G27 KNOT RANGE. A LEE
SIDE TROUGH OVER EASTERN COLORADO WILL STRENGTHEN DURING THE
MORNING WEDNESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 100 72 100 73 / 0 0 0 0
GCK 100 72 99 72 / 20 10 0 0
EHA 98 71 96 70 / 20 10 0 0
LBL 99 71 98 71 / 20 0 0 0
HYS 103 75 101 74 / 0 0 0 0
P28 101 74 101 74 / 20 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURKE
SHORT TERM...BURKE
LONG TERM...SUGDEN
AVIATION...BURKE
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
239 AM CDT WED JUL 4 2012
...UPDATED FOR THE SYNOPSIS AND THE SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 231 AM CDT WED JUL 4 2012
THE ANALYSIS OF THE 04/00Z UPPER AIR ANALYSIS SHOWED SLIGHT CHANGES
FROM YESTERDAY, WITH A 90 TO 110 KNOT EASTERLY JET ZIPPING THROUGH
OREGON AND TURNING NORTHEAST INTO NORTHERN SASKATCHEWAN, THEN
TURNING SOUTHEASTWARD OVER NORTHERN MANITOBA AND NORTHERN ONTARIO.
A SOUTHERLY JET IN THE 90 KNOT RANGE WAS FROM EASTERN QUEBEC TO A
POINT ABOUT 125 MILES OFF THE EASTERN NORTH CAROLINA COAST. WINDS
OVER WESTERN KANSAS AT THE 250MB LEVEL WERE LIGHT AND GENERALLY
UNDER 10 KNOTS. AT THE 500MB LEVEL, A STRONG HIGH PRESSURE RIDGE
RAN NORTHEAST FROM NORTHERN NEW MEXICO THROUGH NORTHWESTERN KANSAS
AND THEN CONTINUED NORTHWARD INTO WESTERN ONTARIO. A LOW PRESSURE
SHORT WAVE HAD FORMED OVER WESTERN ALBERTA SINCE YESTERDAY, WITH A
TROUGH TRAILING SOUTHWESTWARD INTO NORTHERN WASHINGTON. THE 700MB
CHART DISPLAYED A SIMILAR HIGH PRESSURE RIDGE AS DID THE 500MB
CHART, AND ALSO HAD A CUT OFF LOW OVER NORTH CENTRAL ALBERTA. THE
700MB TEMPERATURE AT DDC WAS 11C DEGREES, THE SAME AS IT HAS BEEN
THE PAST 3 DAYS. AT THE 850MB LEVEL, A LARGE HIGH PRESSURE SYSTEM
MAINTAINED ITSELF OVER THE SOUTHEASTERN UNITED STATES, WHILE LOW
PRESSURE TROUGHS WERE EVIDENT BOTH WEST AND EAST OF THE COLORADO
ROCKIES. THE 850MB TEMPERATURE AT DDC WAS 27C DEGREES, EXACTLY
WHAT IT WAS 24 HOURS AGO. THE MAIN DIFFERENCE NOTICEABLE FROM
YESTERDAY IS A LITTLE MORE MOISTURE IN THE LOWER LAYERS, WITH THE
DDC 850MB DEW POINT AT +11C.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 231 AM CDT WED JUL 4 2012
AN OUTFLOW BOUNDARY FROM CONVECTION EARLIER IN COLORADO COLLIDED
WITH A LITTLE MOISTURE FLOWING NORTH FROM OKLAHOMA TO TRIGGER A FEW
WIDELY SCATTERED SHOWERS IN WESTERN KANSAS ABOUT 04-05Z. BOTH THE
HRRR AND RUC MODELS BRING THIS PRECIPITATION A LITTLE FARTHER EAST
INTO OUR CWA, INCLUDING DEVELOPING A FEW SHOWERS IN OUR SOUTH
CENTRAL AND SOUTHEAST ZONES TOWARD 12Z. I HAVE PLACED LOW 16 PERCENT
POPS IN OUR WESTERN 1/3RD AND SOUTHERN TIER OF COUNTIES THROUGH
14Z. RECENT RADAR TRENDS AS OF 07Z HAD THE SHOWER ACTIVITY ON A
DISSIPATING AND DOWNWARD TREND. WENT WITH WIDELY SCATTERED SHOWERS
AND ISOLATED THUNDERSTORMS, AND VERY LOW QPF AMOUNTS IN THE 0.01
RANGE. DO NOT THINK ANY ONE LOCATION WILL SEE ANY SIGNIFICANT
PRECIPITATION, AS THE MID LAYERS ARE REALLY DRY. THE LEE SIDE
TROUGH WILL DEEPEN QUICKLY THIS MORNING OVER EASTERN COLORADO,
WITH OUR LIGHT SOUTHEAST WINDS THEN SHIFTING SOUTHWEST AND
INCREASING IN THE 18G28MPH RANGE FOR THE REST OF THIS 4TH OF JULY
HOLIDAY. I AM SURE THE AREA FIREWORKS AND FIRE DEPARTMENTS WILL
NOT LIKE THIS WIND FORECAST, BUT THE A GOOD FORECAST IS BETTER
THAN A WISHFUL FORECAST. IT WILL AGAIN BE HOT WITH MAX
TEMPERATURES FROM 98F IN ELKHART TO 103F NEAR HAYS, VERY CLOSE TO
WHAT THE MAX TEMPERATURES WERE TUESDAY.
MOSTLY CLEAR TO CLEAR SKIES ARE EXPECTED TONIGHT, WITH SOUTH TO
SOUTHWEST WINDS STAYING UP IN THE 15G20 MPH RANGE THROUGH 03Z, THEN
THE WINDS SHOULD FALL TO AROUND 10 MPH BY 12Z. TEMPERATURES WILL NOT
FALL QUICKLY DUE TO SUSTAINED WINDS, BUT BY THURSDAY MORNING SHOULD BE
IN THE 69F DEGREES (XTRM SOUTHWEST AROUND ELKHART) TO AROUND 74F
DEGREES (NORTHEAST NEAR HAYS) RANGE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 214 PM CDT TUE JUL 3 2012
MEDIUM RANGE MODELS AND THE MAJORITY OF GFS ENSEMBLE MEMBERS
INDICATE UPPER LEVEL RIDGING REMAINING DOMINATE ACROSS THE CENTRAL
PLAINS WITH ONLY A SLIGHT WESTWARD RETROGRESSION MOVEMENT THROUGH
THE WEEKEND. AS A RESULT, HOT AND MOSTLY DRY CONDITIONS ARE LIKELY
TO CONTINUE ACROSS WESTERN KANSAS INTO THE WEEKEND. ALTHOUGH, A
SERIES OF H5 VORT MAXES ARE PROJECTED TO CONTINUE CLIMBING NORTHEAST
ON THE BACK SIDE OF THE RIDGE ACROSS THE ROCKIES. ALONG WITH A
PREVAILING LEE SIDE TROUGH ACROSS EASTERN COLORADO, DIURNALLY DRIVEN
ISOLATED THUNDERSTORMS ARE EXPECTED TO DEVELOP ON THE FRONT RANGE OF
COLORADO EACH AFTERNOON THEN DRIFT EASTWARD, POTENTIALLY INTO
EXTREME WESTERN KANSAS, EARLY IN THE PERIOD. OTHER THAN THAT, WILL
KEEP A MOSTLY DRY FORECAST FOR WESTERN KANSAS THROUGH THE WEEKEND.
THE MODELS HINT AT A NORTHWEST FLOW DEVELOPING ACROSS THE WESTERN
HIGH PLAINS SOMETIME EARLY NEXT WEEK AS THE RIDGE PULLS FURTHER
WEST. THIS COULD POTENTIALLY BRING PRECIP CHANCES BACK TO PORTIONS
OF WESTERN KANSAS LATE IN THE PERIOD.
TEMPERATURES ARE LIKELY TO REMAIN NEAR TO POSSIBLY JUST ABOVE NORMAL
AS UPPER LEVEL RIDGING CONTINUES TO CONTROL THE CENTRAL PLAINS
THROUGH THE WEEKEND. AGAIN, THE GFS AND ECMWF SHOW LITTLE DIFFERENCE
BETWEEN H85 TEMPERATURES FROM DAY TO DAY WITH AFTERNOON VALUES OF
MID TO UPPER 20S(C) ACROSS CENTRAL KANSAS TO NEAR 30C ALONG THE
COLORADO BORDER THROUGH SATURDAY. LOOK FOR HIGHS GENERALLY FROM THE
UPPER 90S(F) TO JUST ABOVE 100F WITH LOWS ANYWHERE FROM THE UPPER
60S(F) TO THE LOWER TO MID 70S(F) THROUGH SATURDAY. SLIGHTLY COOLER
TEMPERATURES ARE POSSIBLE INTO THE EARLY PART OF NEXT WEEK AS THE
UPPER LEVEL RIDGE IS EXPECTED TO PULL BACK INTO THE INTERMOUNTAIN
WEST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1209 AM CDT WED JUL 4 2012
EXPECT CLEAR SKIES OVERNIGHT WITH JUST A FEW WIDELY SCATTERED
SHOWERS NEAR THE COLORADO BORDER THROUGH 10Z. WINDS TONIGHT WILL
BE SOUTHEAST AT AROUND 10 KNOTS, SWITCHING TO SOUTHWEST AND
INCREASING AFTER 15Z WEDNESDAY INTO THE 17G27 KNOT RANGE. A LEE
SIDE TROUGH OVER EASTERN COLORADO WILL STRENGTHEN DURING THE
MORNING WEDNESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 100 72 100 73 / 0 0 0 0
GCK 100 72 99 72 / 20 10 0 0
EHA 98 71 96 70 / 20 10 0 0
LBL 99 71 98 71 / 20 0 0 0
HYS 103 75 101 74 / 0 0 0 0
P28 101 74 101 74 / 20 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURKE
SHORT TERM...BURKE
LONG TERM...JJOHNSON
AVIATION...BURKE
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1230 PM EDT WED JUL 4 2012
.SYNOPSIS...
A FRONTAL SYSTEM WILL MOVE ACROSS THE REGION LATER TODAY INTO
TONIGHT WITH SHOWERS AND THUNDERSTORMS. HIGH PRESSURE RETURNS LATE
THURSDAY INTO FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1230 PM UPDATE...THIS MORNING`S BAND OF SHOWERS HAS PUSHED INTO
NEW BRUNSWICK, WITH JUST SOME SCATTERED SHOWERS ACROSS PORTIONS OF
EASTERN MAINE. WE SHOULD SEE A BREAK FOR THE NEXT FEW HOURS,
BUT MORE PRECIPITATION WILL DEVELOP AFTER MID AFTERNOON. SATELLITE
IMAGERY IS ACTUALLY SHOWING SOME SIGNIFICANT BREAKS IN THE CLOUD
COVER OVER SOUTHWESTERN MAINE, WHICH WILL HELP TO ALLOW MORE
SHOWER ACTIVITY TO POP UP. MADE ADJUSTMENTS TO POPS AND SKY COVER
WITH THIS UPDATE. NO OTHER CHANGES WERE NEEDED.
900 AM UPDATE...HAVE MADE FAIRLY SIGNIFICANT ADJUSTMENTS TO POPS
WITH THIS UPDATE. A NORTH-SOUTH ORIENTED BAND OF LIGHT TO
OCCASIONALLY MODERATE SHOWERS IS CURRENTLY SHIFTING EASTWARD
ACROSS CENTRAL AND EASTERN MAINE THIS MORNING, ASSOCIATED WITH
WARM AIR ADVECTION AHEAD OF AN APPROACHING WARM FRONT. ONCE THIS
BAND GOES BY, IN THE NEXT 2-3 HOURS OR SO, EXPECT MAINLY SCATTERED
SHOWERS INTO MID AFTERNOON. THEN ACTIVITY BEGINS TO INCREASE FROM
THE WEST AS A COLD FRONT SINKS SOUTHWARD FROM QUEBEC. THE 3KM HRRR
MODEL SEEMS TO HAVE A GOOD HANDLE ON THINGS THIS MORNING, AND IT
SHOWS THE SECOND BAND OF SHOWERS AND THUNDERSTORMS MOVING INTO THE
NORTHERN MAINE WOODS 5-7 PM TODAY. THE HRRR IS SOMETIMES A BIT
SLOW WITH PRECIP, SO WHILE I FOLLOWED IT FOR MY POPS TODAY, I DID
BRING THINGS IN A LITTLE EARLIER THAN IT SHOWS. CAPES WILL BE
ENOUGH FOR THUNDER THIS AFTERNOON AND EVENING, BUT DON`T
ANTICIPATE ANY KIND OF SEVERE WEATHER, ESPECIALLY GIVEN THE
ABUNDANT CLOUD COVER THIS MORNING. THE MAIN CONCERN WILL THE
POTENTIAL FOR THE STRONGER SHOWERS TO PRODUCE BRIEFLY HEAVY
RAINFALL, ESPEICALLY THIS AFTERNOON AND EVENING AS PWATS INCREASE
TO AROUND 1.5 INCHES POST WARM FRONTAL PASSAGE. OTHER THAN THE
POPS AND SOME SLIGHT ADJUSTMENTS TO SKY COVER AND WINDS, NO OTHER
CHANGES WERE NEEDED.
PREVIOUS DISCUSSION...A SURFACE TROUGH AND UPPER LEVEL SYSTEM
WILL MOVE ACROSS THE REGION TODAY. EXPECT SHOWERS AND WILL ALSO
MENTION SCATTERED THUNDERSTORMS. LOW PRESSURE IS EXPECTED TO
DEVELOP ALONG THE COAST LATE TONIGHT. WILL USE THE HRRR TO TIME
PRECIPITATION THEN TRANSITION TO MODEL BLEND LATER IN MORNING.
WILL USE THE SREF FOR POPS. FOR WIND WILL BLEND THE NAM12 AND
GMOS. THE GMOS USED FOR TEMPERATURE AND WILL INCREASE MAXIMUM
TEMPERATURE A FEW DEGREES. FOR QPF WILL BLEND THE GFS40 AND THE
ECMWF.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
LEANED CLOSELY TO THE ECMWF BLENDED W/THE SREF FOR THE POPS CYCLE.
THEREFORE, SHOWERS WILL BE AROUND ON THURSDAY AND CHANCES WILL
INCREASE ESPECIALLY DURING THE AFTERNOON AS THE LOW CLOSES OFF
NEAR NOVA SCOTIA. THE INVERTED SFC TROF WILL LEAD TO A CONVERGENCE
ZONE AND A VIGOROUS VORTICITY MAX DIVING SE ACROSS THE REGION WILL
ALLOW FOR FORCING TO ALLOW FOR SHOWERS/PERIODS OF RAIN ESPECIALLY
BY THE AFTERNOON INTO EARLY EVENING. THE BEST CHANCES FOR PRECIP
WILL BE ACROSS THE EASTERN 1/2 OF THE CWA. SBCAPES FROM THE MDL
SOUNDINGS ARE SHOWN TO BE LESS THAN 500 JOULES AND PLENTY OF LLVL
MOISTURE WILL LEAD TO MOSTLY CLOUDY TO OVERCAST CONDITIONS KEEPING
INSTABILITY DOWN. THEREFORE, DECIDED TO KEEP THE MENTION OF TSTMS
OUT OF THE FCST. THE CAVEAT TO THIS IS MORE SUNSHINE WILL LEAD TO
INCREASED BUOYANCY AND THEREFORE A UNSTABLE ENVIRONMENT. THIS WILL
NEED TO BE RE-ASSESSED BY THE DAYCREW. FOLLOWED THE DAYCREW/S
MAXES FOR THURSDAY W/MID TO UPPER 70S. SHOWERS WILL WIND DOWN
THURSDAY NIGHT W/SOME CLEARING EXPECTED AS CLOSED LOW MIGRATES E
AND UPPER RIDGE MOVES OVER THE CWA. THIS WILL ALLOW FOR FOG TO
FORM BY FRIDAY MORNING AND THEREFORE ADDED THIS TO THE GRIDS FOR
LATER THURSDAY NIGHT INTO FRIDAY MORNING.
UPPER RIDGE QUICKLY PUSHES E BY FRIDAY AFTERNOON AS YET ANOTHER
FRONTAL BOUNDARY APCHS FROM QUEBEC. UPPER LEVEL DIFLUENCE COMBINED
W/DAYTIME HEATING AND UPPER LEVEL COOLING WILL LEAD TO INCREASED
INSTABILITY. CONVECTIVE PARAMETERS FROM THE GFS AND NAM SHOW SBCAPES
MAXING OUT AROUND 1000 JOULES AND BULK SHEAR(0-6KM) IS FCST TO BE
30-35 KTS. MOISTURE IS AVAILABLE THROUGH 700MBS. TEMPERATURES ARE
FCST TO HIT THE 80S FOR MOST OF OF THE CWA AS WELL. STAYED W/TSTMS
FOR FRIDAY AFTERNOON AS DAYCREW HAD. STILL SOME TIME TO ASSESS
WHETHER ENHANCED WORDING WILL BE NEEDED.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
LOADED GMOS AND THEN BLENDED IN THE ECMWF TO FIT BETTER W/THE
PRECIP CHANCES AND SKY.
GMOS SKY GRIDS NOT MATCHING SYNOPTIC PATTERN FOR SATURDAY INTO
POSSIBLY SUNDAY AS A FRONTAL SYSTEM SLOWLY CROSSES THE REGION
W/THE THREAT FOR SHOWERS AND POSSIBLY A TSTM. UNSETTLED PATTERN
CONTINUES INTO EARLY NEXT WEAK W/CLOSED UPPER LOW IN SE CANADA
ALLOW FOR SERIES OF DISTURBANCES TO AFFECT THE REGION. THIS MEANS
A CHANCE FOR SHOWERS AND AFTERNOON/EVENING TSTMS. THERE IS THE
POSSIBILITY THAT MONDAY COULD BE THE BETTER DAY OF ALL AS WEAK SFC
RIDGING COULD ALLOW FOR A DRY DAY.
GMOS TEMPERATURES LOOKED REASONABLE BUT TWEAKED THE OVERNIGHT LOWS
UPWARD GIVEN THE OVERALL UNSETTLED PATTERN. KNOCKED DOWN POPS FOR
MONDAY GIVEN THAT THE ECMWF AND GFS POINT TO A DRY PROFILE THROUGH
700MBS.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
NEAR TERM: EXPECT VFR CONDITIONS THIS MORNING. VFR CONDITIONS
EXPECTED TO LOWER TO MVFR/IFR LATER TODAY INTO TONIGHT.
SHORT TERM: MVFR/IFR FOR THURSDAY ESPECIALLY THURSDAY AFTERNOON
INTO THURSDAY EVENING. FOG THURSDAY NIGHT AND FRIDAY WILL KEEP THE
IFR/MVFR THREAT GOING. VFR FOR THE MOST PART FRIDAY INTO SATURDAY
W/AN OCNL SHOWER DROPPING CONDITIONS BRIEFLY TO MVFR.
&&
.MARINE...
NEAR TERM: HAVE BLENDED THE NAM12 AND GFS40 FOR WIND. WILL LOW
MODEL WINDS 1 TO 2 KNOTS. FOR WAVES: HAVE INITIALIZED WITH
SWAN/NAM. BASED ON SPECTRAL WAVE MODELS CONTINUE TO HAVE HIGH BIAS
FOR WIND WAVES. SO WILL LOWER WAVES 1 FOOT THROUGH PERIOD. LONG
PERIOD WAVE GROUPS EXPECTED TO BE BELOW 1 FOOT.
SHORT TERM: NO HEADLINES ANTICIPATED. A BLEND OF THE GFS AND NAM12
WAS USED FOR THE WINDS INTO FRIDAY AND THEN FOLLOWED W/A BLEND
OF THE GMOS AND GFS40. WINDS WILL AVERAGE 10-15 KTS AT BEST W/WAVE
HEIGHTS NO MORE THAN 3 FT. A SWELL GENERATION CAN BE EXPECTED AS
PERIOD INCREASES LATER THURSDAY INTO FRIDAY W/LOW PRES MOVING E
THROUGH THE OPEN ATLC.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HASTINGS/MIGNONE
SHORT TERM...HEWITT
LONG TERM...HEWITT
AVIATION...HASTINGS/MIGNONE
MARINE...HASTINGS/MIGNONE/HEWITT
AREA FORECAST DISCUSSION
NWS CARIBOU ME
906 AM EDT WED JUL 4 2012
.SYNOPSIS...
A FRONTAL SYSTEM WILL MOVE ACROSS THE REGION LATER TODAY INTO
TONIGHT WITH SHOWERS AND THUNDERSTORMS. HIGH PRESSURE RETURNS LATE
THURSDAY INTO FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
900 AM UPDATE...HAVE MADE FAIRLY SIGNIFICANT ADJUSTMENTS TO POPS
WITH THIS UPDATE. A NORTH-SOUTH ORIENTED BAND OF LIGHT TO
OCCASIONALLY MODERATE SHOWERS IS CURRENTLY SHIFTING EASTWARD
ACROSS CENTRAL AND EASTERN MAINE THIS MORNING, ASSOCIATED WITH
WARM AIR ADVECTION AHEAD OF AN APPROACHING WARM FRONT. ONCE THIS
BAND GOES BY, IN THE NEXT 2-3 HOURS OR SO, EXPECT MAINLY SCATTERED
SHOWERS INTO MID AFTERNOON. THEN ACTIVITY BEGINS TO INCREASE FROM
THE WEST AS A COLD FRONT SINKS SOUTHWARD FROM QUEBEC. THE 3KM HRRR
MODEL SEEMS TO HAVE A GOOD HANDLE ON THINGS THIS MORNING, AND IT
SHOWS THE SECOND BAND OF SHOWERS AND THUNDERSTORMS MOVING INTO THE
NORTHERN MAINE WOODS 5-7 PM TODAY. THE HRRR IS SOMETIMES A BIT
SLOW WITH PRECIP, SO WHILE I FOLLOWED IT FOR MY POPS TODAY, I DID
BRING THINGS IN A LITTLE EARLIER THAN IT SHOWS. CAPES WILL BE
ENOUGH FOR THUNDER THIS AFTERNOON AND EVENING, BUT DON`T
ANTICIPATE ANY KIND OF SEVERE WEATHER, ESPECIALLY GIVEN THE
ABUNDANT CLOUD COVER THIS MORNING. THE MAIN CONCERN WILL THE
POTENTIAL FOR THE STRONGER SHOWERS TO PRODUCE BRIEFLY HEAVY
RAINFALL, ESPEICALLY THIS AFTERNOON AND EVENING AS PWATS INCREASE
TO AROUND 1.5 INCHES POST WARM FRONTAL PASSAGE. OTHER THAN THE
POPS AND SOME SLIGHT ADJUSTMENTS TO SKY COVER AND WINDS, NO OTHER
CHANGES WERE NEEDED.
PREVIOUS DISCUSSION...A SURFACE TROUGH AND UPPER LEVEL SYSTEM
WILL MOVE ACROSS THE REGION TODAY. EXPECT SHOWERS AND WILL ALSO
MENTION SCATTERED THUNDERSTORMS. LOW PRESSURE IS EXPECTED TO
DEVELOP ALONG THE COAST LATE TONIGHT. WILL USE THE HRRR TO TIME
PRECIPITATION THEN TRANSITION TO MODEL BLEND LATER IN MORNING.
WILL USE THE SREF FOR POPS. FOR WIND WILL BLEND THE NAM12 AND
GMOS. THE GMOS USED FOR TEMPERATURE AND WILL INCREASE MAXIMUM
TEMPERATURE A FEW DEGREES. FOR QPF WILL BLEND THE GFS40 AND THE
ECMWF.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
LEANED CLOSELY TO THE ECMWF BLENDED W/THE SREF FOR THE POPS CYCLE.
THEREFORE, SHOWERS WILL BE AROUND ON THURSDAY AND CHANCES WILL
INCREASE ESPECIALLY DURING THE AFTERNOON AS THE LOW CLOSES OFF
NEAR NOVA SCOTIA. THE INVERTED SFC TROF WILL LEAD TO A CONVERGENCE
ZONE AND A VIGOROUS VORTICITY MAX DIVING SE ACROSS THE REGION WILL
ALLOW FOR FORCING TO ALLOW FOR SHOWERS/PERIODS OF RAIN ESPECIALLY
BY THE AFTERNOON INTO EARLY EVENING. THE BEST CHANCES FOR PRECIP
WILL BE ACROSS THE EASTERN 1/2 OF THE CWA. SBCAPES FROM THE MDL
SOUNDINGS ARE SHOWN TO BE LESS THAN 500 JOULES AND PLENTY OF LLVL
MOISTURE WILL LEAD TO MOSTLY CLOUDY TO OVERCAST CONDITIONS KEEPING
INSTABILITY DOWN. THEREFORE, DECIDED TO KEEP THE MENTION OF TSTMS
OUT OF THE FCST. THE CAVEAT TO THIS IS MORE SUNSHINE WILL LEAD TO
INCREASED BUOYANCY AND THEREFORE A UNSTABLE ENVIRONMENT. THIS WILL
NEED TO BE RE-ASSESSED BY THE DAYCREW. FOLLOWED THE DAYCREW/S
MAXES FOR THURSDAY W/MID TO UPPER 70S. SHOWERS WILL WIND DOWN
THURSDAY NIGHT W/SOME CLEARING EXPECTED AS CLOSED LOW MIGRATES E
AND UPPER RIDGE MOVES OVER THE CWA. THIS WILL ALLOW FOR FOG TO
FORM BY FRIDAY MORNING AND THEREFORE ADDED THIS TO THE GRIDS FOR
LATER THURSDAY NIGHT INTO FRIDAY MORNING.
UPPER RIDGE QUICKLY PUSHES E BY FRIDAY AFTERNOON AS YET ANOTHER
FRONTAL BOUNDARY APCHS FROM QUEBEC. UPPER LEVEL DIFLUENCE COMBINED
W/DAYTIME HEATING AND UPPER LEVEL COOLING WILL LEAD TO INCREASED
INSTABILITY. CONVECTIVE PARAMETERS FROM THE GFS AND NAM SHOW SBCAPES
MAXING OUT AROUND 1000 JOULES AND BULK SHEAR(0-6KM) IS FCST TO BE
30-35 KTS. MOISTURE IS AVAILABLE THROUGH 700MBS. TEMPERATURES ARE
FCST TO HIT THE 80S FOR MOST OF OF THE CWA AS WELL. STAYED W/TSTMS
FOR FRIDAY AFTERNOON AS DAYCREW HAD. STILL SOME TIME TO ASSESS
WHETHER ENHANCED WORDING WILL BE NEEDED.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
LOADED GMOS AND THEN BLENDED IN THE ECMWF TO FIT BETTER W/THE
PRECIP CHANCES AND SKY.
GMOS SKY GRIDS NOT MATCHING SYNOPTIC PATTERN FOR SATURDAY INTO
POSSIBLY SUNDAY AS A FRONTAL SYSTEM SLOWLY CROSSES THE REGION
W/THE THREAT FOR SHOWERS AND POSSIBLY A TSTM. UNSETTLED PATTERN
CONTINUES INTO EARLY NEXT WEAK W/CLOSED UPPER LOW IN SE CANADA
ALLOW FOR SERIES OF DISTURBANCES TO AFFECT THE REGION. THIS MEANS
A CHANCE FOR SHOWERS AND AFTERNOON/EVENING TSTMS. THERE IS THE
POSSIBILITY THAT MONDAY COULD BE THE BETTER DAY OF ALL AS WEAK SFC
RIDGING COULD ALLOW FOR A DRY DAY.
GMOS TEMPERATURES LOOKED REASONABLE BUT TWEAKED THE OVERNIGHT LOWS
UPWARD GIVEN THE OVERALL UNSETTLED PATTERN. KNOCKED DOWN POPS FOR
MONDAY GIVEN THAT THE ECMWF AND GFS POINT TO A DRY PROFILE THROUGH
700MBS.
&&
.AVIATION /13Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: EXPECT VFR CONDITIONS THIS MORNING. VFR CONDITIONS
EXPECTED TO LOWER TO MVFR/IFR LATER TODAY INTO TONIGHT.
SHORT TERM: MVFR/IFR FOR THURSDAY ESPECIALLY THURSDAY AFTERNOON
INTO THURSDAY EVENING. FOG THURSDAY NIGHT AND FRIDAY WILL KEEP THE
IFR/MVFR THREAT GOING. VFR FOR THE MOST PART FRIDAY INTO SATURDAY
W/AN OCNL SHOWER DROPPING CONDITIONS BRIEFLY TO MVFR.
&&
.MARINE...
NEAR TERM: HAVE BLENDED THE NAM12 AND GFS40 FOR WIND. WILL LOW
MODEL WINDS 1 TO 2 KNOTS. FOR WAVES: HAVE INITIALIZED WITH
SWAN/NAM. BASED ON SPECTRAL WAVE MODELS CONTINUE TO HAVE HIGH BIAS
FOR WIND WAVES. SO WILL LOWER WAVES 1 FOOT THROUGH PERIOD. LONG
PERIOD WAVE GROUPS EXPECTED TO BE BELOW 1 FOOT.
SHORT TERM: NO HEADLINES ANTICIPATED. A BLEND OF THE GFS AND NAM12
WAS USED FOR THE WINDS INTO FRIDAY AND THEN FOLLOWED W/A BLEND
OF THE GMOS AND GFS40. WINDS WILL AVERAGE 10-15 KTS AT BEST W/WAVE
HEIGHTS NO MORE THAN 3 FT. A SWELL GENERATION CAN BE EXPECTED AS
PERIOD INCREASES LATER THURSDAY INTO FRIDAY W/LOW PRES MOVING E
THROUGH THE OPEN ATLC.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HASTINGS/MIGNONE
SHORT TERM...HEWITT
LONG TERM...HEWITT
AVIATION...HASTINGS/MIGNONE
MARINE...HASTINGS/MIGNONE/HEWITT
AREA FORECAST DISCUSSION
NWS CARIBOU ME
723 AM EDT WED JUL 4 2012
.SYNOPSIS...
A FRONTAL SYSTEM WILL MOVE ACROSS THE REGION LATER TODAY INTO
TONIGHT WITH SHOWERS AND THUNDERSTORMS. HIGH PRESSURE RETURNS LATE
THURSDAY INTO FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE: HAVE ADJUSTED TEMPERATURE AND POP TIMING.
A SURFACE TROUGH AND UPPER LEVEL SYSTEM WILL MOVE ACROSS THE
REGION TODAY. EXPECT SHOWERS AND WILL ALSO MENTION SCATTERED
THUNDERSTORMS. LOW PRESSURE IS EXPECTED TO DEVELOP ALONG THE COAST
LATE TONIGHT. WILL USE THE HRRR TO TIME PRECIPITATION THEN
TRANSITION TO MODEL BLEND LATER IN MORNING. WILL USE THE SREF FOR
POPS. FOR WIND WILL BLEND THE NAM12 AND GMOS. THE GMOS USED FOR
TEMPERATURE AND WILL INCREASE MAXIMUM TEMPERATURE A FEW DEGREES.
FOR QPF WILL BLEND THE GFS40 AND THE ECMWF.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
LEANED CLOSELY TO THE ECMWF BLENDED W/THE SREF FOR THE POPS CYCLE.
THEREFORE, SHOWERS WILL BE AROUND ON THURSDAY AND CHANCES WILL
INCREASE ESPECIALLY DURING THE AFTERNOON AS THE LOW CLOSES OFF
NEAR NOVA SCOTIA. THE INVERTED SFC TROF WILL LEAD TO A CONVERGENCE
ZONE AND A VIGOROUS VORTICITY MAX DIVING SE ACROSS THE REGION WILL
ALLOW FOR FORCING TO ALLOW FOR SHOWERS/PERIODS OF RAIN ESPECIALLY
BY THE AFTERNOON INTO EARLY EVENING. THE BEST CHANCES FOR PRECIP
WILL BE ACROSS THE EASTERN 1/2 OF THE CWA. SBCAPES FROM THE MDL
SOUNDINGS ARE SHOWN TO BE LESS THAN 500 JOULES AND PLENTY OF LLVL
MOISTURE WILL LEAD TO MOSTLY CLOUDY TO OVERCAST CONDITIONS KEEPING
INSTABILITY DOWN. THEREFORE, DECIDED TO KEEP THE MENTION OF TSTMS
OUT OF THE FCST. THE CAVEAT TO THIS IS MORE SUNSHINE WILL LEAD TO
INCREASED BUOYANCY AND THEREFORE A UNSTABLE ENVIRONMENT. THIS WILL
NEED TO BE RE-ASSESSED BY THE DAYCREW. FOLLOWED THE DAYCREW/S
MAXES FOR THURSDAY W/MID TO UPPER 70S. SHOWERS WILL WIND DOWN
THURSDAY NIGHT W/SOME CLEARING EXPECTED AS CLOSED LOW MIGRATES E
AND UPPER RIDGE MOVES OVER THE CWA. THIS WILL ALLOW FOR FOG TO
FORM BY FRIDAY MORNING AND THEREFORE ADDED THIS TO THE GRIDS FOR
LATER THURSDAY NIGHT INTO FRIDAY MORNING.
UPPER RIDGE QUICKLY PUSHES E BY FRIDAY AFTERNOON AS YET ANOTHER
FRONTAL BOUNDARY APCHS FROM QUEBEC. UPPER LEVEL DIFLUENCE COMBINED
W/DAYTIME HEATING AND UPPER LEVEL COOLING WILL LEAD TO INCREASED
INSTABILITY. CONVECTIVE PARAMETERS FROM THE GFS AND NAM SHOW SBCAPES
MAXING OUT AROUND 1000 JOULES AND BULK SHEAR(0-6KM) IS FCST TO BE
30-35 KTS. MOISTURE IS AVAILABLE THROUGH 700MBS. TEMPERATURES ARE
FCST TO HIT THE 80S FOR MOST OF OF THE CWA AS WELL. STAYED W/TSTMS
FOR FRIDAY AFTERNOON AS DAYCREW HAD. STILL SOME TIME TO ASSESS
WHETHER ENHANCED WORDING WILL BE NEEDED.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
LOADED GMOS AND THEN BLENDED IN THE ECMWF TO FIT BETTER W/THE
PRECIP CHANCES AND SKY.
GMOS SKY GRIDS NOT MATCHING SYNOPTIC PATTERN FOR SATURDAY INTO
POSSIBLY SUNDAY AS A FRONTAL SYSTEM SLOWLY CROSSES THE REGION
W/THE THREAT FOR SHOWERS AND POSSIBLY A TSTM. UNSETTLED PATTERN
CONTINUES INTO EARLY NEXT WEAK W/CLOSED UPPER LOW IN SE CANADA
ALLOW FOR SERIES OF DISTURBANCES TO AFFECT THE REGION. THIS MEANS
A CHANCE FOR SHOWERS AND AFTERNOON/EVENING TSTMS. THERE IS THE
POSSIBILITY THAT MONDAY COULD BE THE BETTER DAY OF ALL AS WEAK SFC
RIDGING COULD ALLOW FOR A DRY DAY.
GMOS TEMPERATURES LOOKED REASONABLE BUT TWEAKED THE OVERNIGHT LOWS
UPWARD GIVEN THE OVERALL UNSETTLED PATTERN. KNOCKED DOWN POPS FOR
MONDAY GIVEN THAT THE ECMWF AND GFS POINT TO A DRY PROFILE THROUGH
700MBS.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: EXPECT VFR CONDITIONS THIS MORNING. VFR CONDITIONS
EXPECTED TO LOWER TO MVFR/IFR LATER TODAY INTO TONIGHT.
SHORT TERM: MVFR/IFR FOR THURSDAY ESPECIALLY THURSDAY AFTERNOON
INTO THURSDAY EVENING. FOG THURSDAY NIGHT AND FRIDAY WILL KEEP THE
IFR/MVFR THREAT GOING. VFR FOR THE MOST PART FRIDAY INTO SATURDAY
W/AN OCNL SHOWER DROPPING CONDITIONS BRIEFLY TO MVFR.
&&
.MARINE...
NEAR TERM: HAVE BLENDED THE NAM12 AND GFS40 FOR WIND. WILL LOW
MODEL WINDS 1 TO 2 KNOTS. FOR WAVES: HAVE INITIALIZED WITH
SWAN/NAM. BASED ON SPECTRAL WAVE MODELS CONTINUE TO HAVE HIGH BIAS
FOR WIND WAVES. SO WILL LOWER WAVES 1 FOOT THROUGH PERIOD. LONG
PERIOD WAVE GROUPS EXPECTED TO BE BELOW 1 FOOT.
SHORT TERM: NO HEADLINES ANTICIPATED. A BLEND OF THE GFS AND NAM12
WAS USED FOR THE WINDS INTO FRIDAY AND THEN FOLLOWED W/A BLEND
OF THE GMOS AND GFS40. WINDS WILL AVERAGE 10-15 KTS AT BEST W/WAVE
HEIGHTS NO MORE THAN 3 FT. A SWELL GENERATION CAN BE EXPECTED AS
PERIOD INCREASES LATER THURSDAY INTO FRIDAY W/LOW PRES MOVING E
THROUGH THE OPEN ATLC.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...MIGNONE
SHORT TERM...HEWITT
LONG TERM...HEWITT
AVIATION...MIGNONE
MARINE...MIGNONE/HEWITT
AREA FORECAST DISCUSSION
NWS CARIBOU ME
338 AM EDT WED JUL 4 2012
.SYNOPSIS...
A FRONTAL SYSTEM WILL MOVE ACROSS THE REGION LATER TODAY INTO
TONIGHT WITH SHOWERS AND THUNDERSTORMS. HIGH PRESSURE RETURNS LATE
THURSDAY INTO FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
A SURFACE TROUGH AND UPPER LEVEL SYSTEM WILL MOVE ACROSS THE
REGION TODAY. EXPECT SHOWERS AND WILL ALSO MENTION SCATTERED
THUNDERSTORMS. LOW PRESSURE IS EXPECTED TO DEVELOP ALONG THE COAST
LATE TONIGHT. WILL USE THE HRRR TO TIME PRECIPITATION THEN
TRANSITION TO MODEL BLEND LATER IN MORNING. WILL USE THE SREF FOR
POPS. FOR WIND WILL BLEND THE NAM12 AND GMOS. THE GMOS USED FOR
TEMPERATURE AND WILL INCREASE MAXIMUM TEMPERATURE A FEW DEGREES.
FOR QPF WILL BLEND THE GFS40 AND THE ECMWF.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
LEANED CLOSELY TO THE ECMWF BLENDED W/THE SREF FOR THE POPS CYCLE.
THEREFORE, SHOWERS WILL BE AROUND ON THURSDAY AND CHANCES WILL
INCREASE ESPECIALLY DURING THE AFTERNOON AS THE LOW CLOSES OFF
NEAR NOVA SCOTIA. THE INVERTED SFC TROF WILL LEAD TO A CONVERGENCE
ZONE AND A VIGOROUS VORTICITY MAX DIVING SE ACROSS THE REGION WILL
ALLOW FOR FORCING TO ALLOW FOR SHOWERS/PERIODS OF RAIN ESPECIALLY
BY THE AFTERNOON INTO EARLY EVENING. THE BEST CHANCES FOR PRECIP
WILL BE ACROSS THE EASTERN 1/2 OF THE CWA. SBCAPES FROM THE MDL
SOUNDINGS ARE SHOWN TO BE LESS THAN 500 JOULES AND PLENTY OF LLVL
MOISTURE WILL LEAD TO MOSTLY CLOUDY TO OVERCAST CONDITIONS KEEPING
INSTABILITY DOWN. THEREFORE, DECIDED TO KEEP THE MENTION OF TSTMS
OUT OF THE FCST. THE CAVEAT TO THIS IS MORE SUNSHINE WILL LEAD TO
INCREASED BUOYANCY AND THEREFORE A UNSTABLE ENVIRONMENT. THIS WILL
NEED TO BE RE-ASSESSED BY THE DAYCREW. FOLLOWED THE DAYCREW/S
MAXES FOR THURSDAY W/MID TO UPPER 70S. SHOWERS WILL WIND DOWN
THURSDAY NIGHT W/SOME CLEARING EXPECTED AS CLOSED LOW MIGRATES E
AND UPPER RIDGE MOVES OVER THE CWA. THIS WILL ALLOW FOR FOG TO
FORM BY FRIDAY MORNING AND THEREFORE ADDED THIS TO THE GRIDS FOR
LATER THURSDAY NIGHT INTO FRIDAY MORNING.
UPPER RIDGE QUICKLY PUSHES E BY FRIDAY AFTERNOON AS YET ANOTHER
FRONTAL BOUNDARY APCHS FROM QUEBEC. UPPER LEVEL DIFLUENCE COMBINED
W/DAYTIME HEATING AND UPPER LEVEL COOLING WILL LEAD TO INCREASED
INSTABILITY. CONVECTIVE PARAMETERS FROM THE GFS AND NAM SHOW SBCAPES
MAXING OUT AROUND 1000 JOULES AND BULK SHEAR(0-6KM) IS FCST TO BE
30-35 KTS. MOISTURE IS AVAILABLE THROUGH 700MBS. TEMPERATURES ARE
FCST TO HIT THE 80S FOR MOST OF OF THE CWA AS WELL. STAYED W/TSTMS
FOR FRIDAY AFTERNOON AS DAYCREW HAD. STILL SOME TIME TO ASSESS
WHETHER ENHANCED WORDING WILL BE NEEDED.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
LOADED GMOS AND THEN BLENDED IN THE ECMWF TO FIT BETTER W/THE
PRECIP CHANCES AND SKY.
GMOS SKY GRIDS NOT MATCHING SYNOPTIC PATTERN FOR SATURDAY INTO
POSSIBLY SUNDAY AS A FRONTAL SYSTEM SLOWLY CROSSES THE REGION
W/THE THREAT FOR SHOWERS AND POSSIBLY A TSTM. UNSETTLED PATTERN
CONTINUES INTO EARLY NEXT WEAK W/CLOSED UPPER LOW IN SE CANADA
ALLOW FOR SERIES OF DISTURBANCES TO AFFECT THE REGION. THIS MEANS
A CHANCE FOR SHOWERS AND AFTERNOON/EVENING TSTMS. THERE IS THE
POSSIBILITY THAT MONDAY COULD BE THE BETTER DAY OF ALL AS WEAK SFC
RIDGING COULD ALLOW FOR A DRY DAY.
GMOS TEMPERATURES LOOKED REASONABLE BUT TWEAKED THE OVERNIGHT LOWS
UPWARD GIVEN THE OVERALL UNSETTLED PATTERN. KNOCKED DOWN POPS FOR
MONDAY GIVEN THAT THE ECMWF AND GFS POINT TO A DRY PROFILE THROUGH
700MBS.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: EXPECT VFR CONDITIONS THIS MORNING. VFR CONDITIONS
EXPECTED TO LOWER TO MVFR/IFR LATER TODAY INTO TONIGHT.
SHORT TERM: MVFR/IFR FOR THURSDAY ESPECIALLY THURSDAY AFTERNOON
INTO THURSDAY EVENING. FOG THURSDAY NIGHT AND FRIDAY WILL KEEP THE
IFR/MVFR THREAT GOING. VFR FOR THE MOST PART FRIDAY INTO SATURDAY
W/AN OCNL SHOWER DROPPING CONDITIONS BRIEFLY TO MVFR.
&&
.MARINE...
NEAR TERM: HAVE BLENDED THE NAM12 AND GFS40 FOR WIND. WILL LOW
MODEL WINDS 1 TO 2 KNOTS. FOR WAVES: HAVE INITIALIZED WITH
SWAN/NAM. BASED ON SPECTRAL WAVE MODELS CONTINUE TO HAVE HIGH BIAS
FOR WIND WAVES. SO WILL LOWER WAVES 1 FOOT THROUGH PERIOD. LONG
PERIOD WAVE GROUPS EXPECTED TO BE BELOW 1 FOOT.
SHORT TERM: NO HEADLINES ANTICIPATED. A BLEND OF THE GFS AND NAM12
WAS USED FOR THE WINDS INTO FRIDAY AND THEN FOLLOWED W/A BLEND
OF THE GMOS AND GFS40. WINDS WILL AVERAGE 10-15 KTS AT BEST W/WAVE
HEIGHTS NO MORE THAN 3 FT. A SWELL GENERATION CAN BE EXPECTED AS
PERIOD INCREASES LATER THURSDAY INTO FRIDAY W/LOW PRES MOVING E
THROUGH THE OPEN ATLC.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...MIGNONE
SHORT TERM...HEWITT
LONG TERM...HEWITT
AVIATION...MIGNONE
MARINE...MIGNONE/HEWITT
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
706 PM EDT THU JUL 5 2012
.SYNOPSIS...
FRIDAY APPEARS TO BE A GENERALLY DRY DAY...BUT A FRONT SHOULD BRING
A BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS OVER THE WEEKEND.
BEFORE THE FRONT ARRIVES...TEMPERATURES WILL CREEP UP SLIGHTLY
HIGHER.
&&
.NEAR TERM /THROUGH FRIDAY/...
AN EVENING UPDATE HAS BEEN ISSUED TO LOWER POPS FURTHER OVERNIGHT
AND TO REMOVE THE HEAT ADVISORY HEADLINE FOR TODAY.
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES THE UPPER OHIO VALLEY IN
A NORTHWESTERLY FLOW AS A DEEP RIDGE REMAINS CENTERED ACROSS THE
MIDWEST. AT THE SURFACE, A WEAK SURFACE LOW IS CENTERED ACROSS
EASTERN PA WITH A SERIES OF BOUNDARIES. ONE HAS PUSHED EAST THE AREA
OF INTO CENTRAL PA WITH AN OUTFLOW BOUNDARY HAS SLID SOUTHWEST OF
THE EASTERN OHIO ZONES. THAT LEAVES THE UPPER OHIO VALLEY IN A WORKED
OVER ENVIRONMENT WITH JUST WEAK INSTABILITY REMAINING AS CONVECTIVE
INHIBITION INCREASES.
FOR TONIGHT, ANY LINGERING ISOLATED CONVECTION THIS EVENING WILL
DIMINISH OVERNIGHT WITH THE LOSS OF HEATING AND LITTLE INSTABILITY
TO WORK WITH. CLOUD COVERAGE WILL DECREASE OVERNIGHT AS IT DIMINISHES
AND PUSHES SOUTHEAST OF THE AREA. WITH THE SUPPORT FROM RECENT TEMPS
TRENDS AND LAMP GUIDANCE THERE IS LITTLE CHANGE TO OVERNIGHT LOWS,
WITH LOWS RANGING FROM THE MID 60S NORTH OF THE I-80 CORRIDOR AND
ACROSS THE EASTERN RIDGES TO THE NEAR 70 ACROSS THE LOWLANDS
ELSEWHERE.
FRIDAY SHOULD BE A DRY DAY FOR MOST LOCATIONS. STILL CANNOT RULE OUT
A THUNDERSTORM ALONG AND SOUTH OF INTERSTATE 70 WITH TEMPERATURES
REACHING CONVECTIVE LEVELS...EVEN IF THERE IS NO UPPER LEVEL SUPPORT.
SPEAKING OF TEMPERATURES...FRIDAY LOOKS TO BE THE WARMEST DAY OF THE
YEAR SO FAR. THERE IS THE POSSIBILITY THAT PITTSBURGH...AND
LOCATIONS TO THE SOUTH AND WEST...WILL REACH 100 DEGREES ON FRIDAY.
THE LAST TIME THAT PITTSBURGH REACHED A HIGH TEMPERATURE OF 100
DEGREES WAS ON JULY 15 IN 1995. ALMOST ALL COUNTIES WILL BE UNDER A
HEAT ADVISORY ONCE AGAIN. ACROSS PORTIONS OF EASTERN OHIO...HEAT
INDEX VALUES WILL BE RIGHT AROUND 105...WHICH IS THE CRITERIA FOR AN
EXCESSIVE HEAT WARNING. CONSIDERING IMPACTS OF EXTENDED POWER
OUTAGES THROUGHOUT THIS AREA...WILL GO AHEAD AND ISSUE WARNING FOR
THOSE COUNTIES.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
A FRONT WILL SLIDE TO THE SOUTH FROM MICHIGAN SATURDAY INTO SUNDAY.
SYNOPTIC MODELS HAVE NOT BEEN DOING WELL WITH CONVECTIVE
PRECIPITATION OVER THE LAST FEW DAYS...BUT AM HOPING THE MODELS WILL
BE MORE RELIABLE WITH THIS LARGER-SCALE FEATURE. FRONT SEEMS TO HAVE
SLOWED DOWN FROM PREVIOUS MODEL RUNS...AND HAVE SLIGHTLY DELAYED
ARRIVAL OF PRECIPITATION. IN ADDITION...WITH THE FRONT STILL ACROSS
THE SOUTHERN PORTION OF THE REGION SUNDAY...HAVE BUMPED UP POPS
SLIGHTLY MORE DUE TO CONVECTIVE POTENTIAL. DO NOT HAVE ENOUGH
CONFIDENCE IN TIMING/COVERAGE TO GO LIKELY AT THIS TIME.
WITH FRONT SLOWING DOWN...THIS WILL ALLOW FOR MORE SUNSHINE ON
SATURDAY...AND HAVE ACCORDINGLY BUMPED UP HIGH TEMPERATURES A FEW
DEGREES. THIS WILL BRING HEAT INDEX VALUES VERY SIMILAR TO FRIDAY/S
VALUES. WILL ONLY GO WITH EXCESSIVE HEAT WATCH FOR LOWER CONFIDENCE
IN THE INTERSTATE 77 COUNTIES...AND HAVE HIGH ENOUGH CONFIDENCE FOR
HEAT ADVISORY IN MANY OTHER COUNTIES. THE FRONT SHOULD DROP HIGH
TEMPERATURES INTO THE 80S ON SUNDAY...ENDING A NEED FOR HEAT
HEADLINES.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
BLEND OF RECENT ECMWF AND NAEFS MODEL OUTPUT SHOW UPPER LEVEL
TROUGHING ACROSS EASTERN U.S. AND CANADA EARLY NEXT WEEK. THIS
SHOULD RESULT IN GENERALLY DRY SEASONABLE CONDITIONS THIS PERIOD
ACROSS THE UPPER OHIO VALLEY, AS TEMPERATURES ALOFT WILL NOT BE SO
WARM AND NORTHWESTERLY WINDS PROVIDE SOMEWHAT LOWER HUMIDITY.
STILL, AS SEEN THIS WEEK, A BOUT OF PRECIPITATION CANNOT BE RULED
OUT, BUT THE CHANCE OF SHOWERS FOR ANY ONE PERIOD WERE JUST TOO LOW
TO MENTION.
FOR THE FORECAST OF DAILY TEMPERATURES, RELIED ON BLEND OF
ECMWF-INFLUENCED HPC GUIDANCE AND GFS MODEL OUTPUT.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
MAINLY VFR ACROSS THE UPPER OHIO VALLEY THROUGH DAYTIME FRIDAY,
WITH THE ONLY RESTRICTION WORTH MENTIONING IN EARLY MORNING MVFR
HAZE.
SURFACE WINDS WILL BECOME LIGHT AND VARIABLE OVERNIGHT. GENERALLY
WEST AT 10 KTS DAYTIME FRIDAY.
OUTLOOK...FRIDAY NIGHT THROUGH TUESDAY...
EXPECT MAINLY VFR. RESTRICTIONS POSSIBLE DUE TO EARLY MORNING HAZE
AND POSSIBLE PREFRONTAL THUNDERSTORMS LATE SATURDAY AND SUNDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...EXCESSIVE HEAT WARNING FROM NOON TO 8 PM EDT FRIDAY FOR OHZ039-
048-057-058-068.
HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR OHZ039-048-
057>059-068-069.
EXCESSIVE HEAT WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY
EVENING FOR OHZ039-048-057-058-068.
HEAT ADVISORY FROM NOON TO 8 PM EDT FRIDAY FOR OHZ040-041-049-
050-059-069.
HEAT ADVISORY FROM NOON TO 8 PM EDT SATURDAY FOR OHZ040-041-
049-050-059-069.
PA...HEAT ADVISORY FROM NOON TO 8 PM EDT FRIDAY FOR PAZ007-013-014-
020>023-029-031-073-075.
HEAT ADVISORY FROM NOON TO 8 PM EDT SATURDAY FOR PAZ007-013-
014-020>023-029-031-073-075.
WV...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR WVZ004-012-
021>023.
HEAT ADVISORY FROM NOON TO 8 PM EDT FRIDAY FOR WVZ001>004-012-
021>023.
HEAT ADVISORY FROM NOON TO 8 PM EDT SATURDAY FOR WVZ001>004-
012-021>023.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
331 PM EDT WED JUL 4 2012
.SYNOPSIS...
IT WILL BE GETTING HOT AND HUMID THIS HOLIDAY AFTERNOON, UNTIL A
BAND OF THUNDERSTORMS BLOWS THROUGH WITH POTENTIALLY DAMAGING
WIND, HAIL, HEAVY DOWNPOURS AND FREQUENT LIGHTNING. THE
THUNDERSTORMS WILL DECREASE TO NO MORE THAN SCATTERED COVERAGE
THIS EVENING. BROAD HIGH PRESSURE WILL MAINTAIN HOT AND HUMID
CONDITIONS ACROSS THE UPPER OHIO VALLEY INTO SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
HAVE CONTINUED MENTION OF LIKELY THUNDERSTORMS LATE THIS HOLIDAY
AFTERNOON, WITH POTENTIAL FOR BECOMING SEVERE WITH DAMAGING WIND,
LARGE HAIL, HEAVY DOWNPOURS, AND FREQUENT LIGHTNING.
SPC GUIDANCE CONTINUES TO INCLUDE THE ENTIRE UPPER OHIO VALLEY AS
HAVING A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
EARLY EVENING.
RECENT RADAR DATA SHOWS THUNDERSTORMS DEVELOPING ALONG CONVERGENCE
ZONES, UPWIND FROM CIRRUS-ANVIL-SHADED AREAS OVER NORTHWEST
PENNSYLVANIA LEFTOVER FROM PREVIOUS THUNDERSTORMS OVER NORTHERN
PENNSYLVANIA MOUNTAINS, PLUS NORTHERLY BREEZES OFF LAKE ERIE.
RECENT HRRR MODEL OUTPUT SHOWS THUNDERSTORMS RAPIDLY DEVELOPING
INTO A BAND ACROSS THE TIER OF COUNTIES WITHIN NEW PHILADELPHIA-
PITTSBURGH CORRIDORS, AND THEN MOVING SOUTH PAST THE I-70 AND
I-68 CORRIDORS BY EARLY EVENING.
ALL THESE STORMS WILL HAVE PLENTY OF POTENTIAL ENERGY TO WORK
WITH, DUE TO THE HUMID CONDITIONS, AND SUFFICIENT VERTICAL SHEAR
TO BECOME SEVERE.
HEAVY RAINS WITH THE STORMS MAY CAUSE FLOODING IF RAIN AMOUNTS
EXCEED 2 INCHES IN LESS THAN 2 HOURS.
THUNDERSTORM WILL HAVE A DRAMATIC EFFECT ON TEMPERATURES. SO
FORECAST OF HIGHS THIS AFTERNOON IS COMPLICATED. MADE BEST
JUDGMENT BASED ON OUR HUNCH OF WHEN AND WHERE THUNDERSTORMS
DEVELOP.
HEAT ADVISORIES MAINTAINED BUT HIGH TEMPERATURES COULD COME SHORT
DUE TO CLOUDS AND THUNDERSTORMS.
EXPECT THUNDERSTORM COVERAGE TO DECREASE THIS EVENING, AND BE GONE AFTER
MIDNIGHT. WILL CONSIDER FOG PROSPECTS WITH LATER FORECAST
ISSUANCES, BASED ON RAINFALL PATTERNS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
RECENT SREF MODEL OUTPUT CONTINUES TO SHOW THE BROAD HIGH PRESSURE
ACROSS THE EASTERN AND CENTRAL U.S. STRENGTHENING THURSDAY AND
FRIDAY, THEN SHRINKING SOUTH SATURDAY.
THE MAIN EFFECT OF THE HIGH PRESSURE WILL BE TO CONTINUE THE HOT
HUMID CONDITIONS, WITH GFS, NAM, AND ECMWF MOS SHOWING THURSDAY
AND FRIDAY HAVING THE HIGHEST AFTERNOON TEMPERATURES. AS THE HIGH
PRESSURE SHRINKS SOUTH SATURDAY, HIGH TEMPERATURES SATURDAY MAY BE
A COUPLE DEGREES LOWER THAN FRIDAY. HOWEVER, HUMID CONDITIONS WILL
PERSIST.
SO HAVE ADDED A HEAT ADVISORY FOR THURSDAY FOR MOST OF THE UPPER
OHIO VALLEY, EXCEPT THE APPALACHIAN MOUNTAINS AND I-80 CORRIDOR.
IN HAZARDOUS WEATHER OUTLOOK HAVE MENTIONED HEAT INDICES WELL INTO
THE 90S FRIDAY AND POSSIBLY SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THERE IS GFS/ECMWF ENSEMBLE AGREEMENT TO BEGIN THE PERIOD THAT DEEP
RIDGING WILL BE CENTERED ACROSS THE MISSOURI VALLEY. THE UPPER OHIO
VALLEY WILL BE IN A NORTHWESTERLY FLOW ON THE EASTERN PERIPHERY OF THE
RIDGE. THE MODEL CONSENSUS INDICATES AN AMPLIFYING TREND WITH THE
RIDGE DOMINATING THE WESTERN TWO THIRDS OF THE CONUS AND LOWERING
MID-LEVEL HEIGHTS ACROSS THE UPPER OHIO VALLEY AS A TROUGH BUILDS
INTO THE NORTHEAST.
AFTER A COLD FRONT DROPS SOUTHEAST ACROSS THE AREA AND BRINGS
CHANCE POPS ON SUNDAY, A DRIER AND COOLER FORECAST IS IN PLACE FOR
EARLY NEXT WEEK. HAVE GONE DRY OR WITH SILENT SLIGHT CHC POPS FOR
LOWERING HEIGHTS THROUGH WEDNESDAY. UNCERTAINTY ENTERS THE FORECAST
BY NEXT THURSDAY WITH THE POTENTIAL OF A MID-LEVEL TROUGH PUSHING
FROM THE UPPER MIDWEST SOUTHEASTWARD ACROSS THE AREA. TEMPS ARE
AROUND 5 DEGREES ABOVE NORMAL AHEAD OF THE FRONT ON SUNDAY.
TEMPERATURES WILL THEN LOWER TO NEAR SEASONABLE VALUES FOR MONDAY, TUESDAY
AND WEDNESDAY.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
BANDS OF SCATTERED TO NUMEROUS THUNDERSTORMS WILL MOVE SOUTHEASTWARD
ACROSS THE TERMINALS INTO THE EVENING. A FEW OF THE STORMS MAY
BECOME SEVERE WITH DAMAGING WIND AND HAIL. TEMPO GROUPS ARE
FORECAST ACROSS THE TERMINALS FOR VISIBILITY RESTRICTIONS WITH
THUNDERSTORMS. THE BEST WINDOW LOOKS TO BE FOR
KPIT/KBVI/KAGC/KHLG/KLBE THROUGH 22Z AND FOR KMGW THROUGH 00Z. ASIDE
FROM THUNDERSTORMS, PREVAILING WINDS WILL BE WESTERLY AT AROUND 10
KTS TODAY.
SHOWERS AND THUNDERSTORMS WILL DIMINISH OVERNIGHT. ABUNDANT SURFACE
MOISTURE, ESPECIALLY AT THE TERMINALS WHICH RECEIVE HEAVY RAINFALL
FROM THUNDERSTORMS, WILL ALLOW FOR SOME PRE-DAWN FOG TO DEVELOP ON
THURSDAY MORNING.
OUTLOOK...THURSDAY NIGHT THROUGH MONDAY...
MOSTLY VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD WITH MVFR HAZE
POSSIBLE, ESPECIALLY DURING THE MORNING. RESTRICTIONS ARE POSSIBLE
IN SCATTERED STORMS LATE SATURDAY AND AGAIN ON SUNDAY AS A FRONT
SAGS SOUTHWARD THROUGH THE REGION. VFR CONDITIONS WILL RETURN ON
MONDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR OHZ039>041-
048>050-057>059-068-069.
HEAT ADVISORY FROM NOON TO 7 PM EDT THURSDAY FOR OHZ039>041-
048>050-057>059-068-069.
PA...HEAT ADVISORY FROM NOON TO 7 PM EDT THURSDAY FOR PAZ013-014-
020>022-029-031-073-075.
WV...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR WVZ001>004-012-
021>023.
HEAT ADVISORY FROM NOON TO 7 PM EDT THURSDAY FOR WVZ001>004-
012-021>023.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
212 PM EDT WED JUL 4 2012
.SYNOPSIS...
IT WILL BE GETTING HOT AND HUMID THIS HOLIDAY AFTERNOON, UNTIL A
BAND OF THUNDERSTORMS BLOWS THROUGH WITH POTENTIALLY DAMAGING
WIND, HAIL, HEAVY DOWNPOURS AND FREQUENT LIGHTNING. THE
THUNDERSTORMS WILL DECREASE TO NO MORE THAN SCATTERED COVERAGE
THIS EVENING. BROAD HIGH PRESSURE WILL MAINTAIN HOT AND HUMID
CONDITIONS ACROSS THE UPPER OHIO VALLEY INTO SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
HAVE CONTINUED MENTION OF LIKELY THUNDERSTORMS THIS HOLIDAY AFTERNOON, WITH
POTENTIAL FOR BECOMING SEVERE WITH DAMAGING WIND, LARGE HAIL,
HEAVY DOWNPOURS, AND FREQUENT LIGHTNING.
SPC GUIDANCE HAS NOW INCLUDED THE THE ENTIRE UPPER OHIO VALLEY AS
HAVING A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
EARLY EVENING.
RECENT RADAR DATA SHOWS THUNDERSTORMS DEVELOPING FROM THE OUTFLOW
OF PREVIOUS THUNDERSTORMS OVER NORTHERN PENNSYLVANIA MOUNTAINS, PLUS
NORTHERLY BREEZES OFF LAKE ERIE.
RECENT HRRR MODEL OUTPUT SHOWS THUNDERSTORMS RAPIDLY DEVELOPING
INTO A BAND ACROSS THE TIER OF COUNTIES BETWEEN THE I-80 AND NEW
PHILADELPHIA-PITTSBURGH CORRIDORS BY 3 PM, AND THEN MOVING SOUTH
PAST THE I-70 AND I-68 CORRIDORS BY EARLY EVENING.
ALL THESE STORMS WILL HAVE PLENTY OF POTENTIAL ENERGY TO WORK
WITH, DUE TO THE HUMID CONDITIONS, AND SUFFICIENT VERTICAL SHEAR
TO BECOME SEVERE.
HEAVY RAINS WITH THE STORMS MAY CAUSE FLOODING IF RAIN AMOUNTS
EXCEED 2 INCHES IN LESS THAN 2 HOURS.
THUNDERSTORM WILL HAVE A DRAMATIC EFFECT ON TEMPERATURES. SO
FORECAST OF HIGHS THIS AFTERNOON IS COMPLICATED. MADE BEST
JUDGMENT BASED ON OUR HUNCH OF WHEN AND WHERE THUNDERSTORMS
DEVELOP.
HEAT ADVISORIES MAINTAINED BUT HIGH TEMPERATURES COULD COME SHORT
DUE TO CLOUDS AND THUNDERSTORMS.
EXPECT THUNDERSTORM COVERAGE TO DECREASE THIS EVENING, AND BE GONE AFTER
MIDNIGHT. WILL CONSIDER FOG PROSPECTS WITH LATER FORECAST
ISSUANCES, BASED ON RAINFALL PATTERNS.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
RECENT SREF MODEL OUTPUT CONTINUES TO SHOW THE BROAD HIGH PRESSURE
ACROSS THE EASTERN AND CENTRAL U.S. STRENGTHENING THURSDAY AND
FRIDAY, THEN SHRINKING SOUTH SATURDAY.
THE MAIN EFFECT OF THE HIGH PRESSURE WILL BE TO CONTINUE THE HOT
HUMID CONDITIONS, WITH GFS, NAM, AND ECMWF MOS SHOWING THURSDAY
AND FRIDAY HAVING THE HIGHEST AFTERNOON TEMPERATURES. AS THE HIGH
PRESSURE SHRINKS SOUTH SATURDAY, HIGH TEMPERATURES SATURDAY MAY BE
A COUPLE DEGREES LOWER THAN FRIDAY. HOWEVER, HUMID CONDITIONS WILL
PERSIST.
SO HAVE ADDED A HEAT ADVISORY FOR THURSDAY FOR MOST OF THE UPPER
OHIO VALLEY, EXCEPT THE APPALACHIAN MOUNTAINS AND I-80 CORRIDOR.
IN HAZARDOUS WEATHER OUTLOOK HAVE MENTIONED HEAT INDICES WELL INTO
THE 90S FRIDAY AND POSSIBLY SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
THERE IS GFS/ECMWF ENSEMBLE AGREEMENT TO BEGIN THE PERIOD THAT DEEP
RIDGING WILL BE CENTERED ACROSS THE MISSOURI VALLEY. THE UPPER OHIO
VALLEY WILL BE IN A NORTHWESTERLY FLOW ON THE EASTERN PERIPHERY OF THE
RIDGE. THE MODEL CONSENSUS INDICATES AN AMPLIFYING TREND WITH THE
RIDGE DOMINATING THE WESTERN TWO THIRDS OF THE CONUS AND LOWERING
MID-LEVEL HEIGHTS ACROSS THE UPPER OHIO VALLEY AS A TROUGH BUILDS
INTO THE NORTHEAST.
AFTER A COLD FRONT DROPS SOUTHEAST ACROSS THE AREA AND BRINGS
CHANCE POPS ON SUNDAY, A DRIER AND COOLER FORECAST IS IN PLACE FOR
EARLY NEXT WEEK. HAVE GONE DRY OR WITH SILENT SLIGHT CHC POPS FOR
LOWERING HEIGHTS THROUGH WEDNESDAY. UNCERTAINTY ENTERS THE FORECAST
BY NEXT THURSDAY WITH THE POTENTIAL OF A MID-LEVEL TROUGH PUSHING
FROM THE UPPER MIDWEST SOUTHEASTWARD ACROSS THE AREA. TEMPS ARE
AROUND 5 DEGREES ABOVE NORMAL AHEAD OF THE FRONT ON SUNDAY. TEMPS
THEN COOL TO AROUND NORMAL SEASONAL VALUES BY TUESDAY AND WEDNESDAY.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
BANDS OF SCATTERED TO NUMEROUS THUNDERSTORMS WILL MOVE SOUTHEASTWARD
ACROSS THE TERMINALS THIS AFTERNOON INTO THE EVENING. A FEW OF THE
STORMS MAY BECOME SEVERE WITH DAMAGING WIND AND HAIL. TEMPO
GROUPS ARE FORECAST ACROSS THE TERMINALS FOR VISIBILITY
RESTRICTIONS WITH THUNDERSTORMS. THE BEST WINDOW LOOKS TO BE
STARTING BY 19Z FOR KPIT/KBVI/KAGC/KHLG/KLBE AND AROUND 21Z AT
KMGW. ASIDE FROM THUNDERSTORMS, PREVAILING WINDS WILL BE
WESTERLY AT AROUND 10 KTS TODAY.
SHOWERS AND THUNDERSTORMS WILL DIMINISH OVERNIGHT. ABUNDANT SURFACE
MOISTURE, ESPECIALLY AT THE TERMINALS WHICH RECEIVE HEAVY RAINFALL
FROM THUNDERSTORMS, WILL ALLOW FOR SOME PRE-DAWN FOG TO DEVELOP ON
THURSDAY MORNING.
OUTLOOK...THURSDAY NIGHT THROUGH MONDAY...
MOSTLY VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD WITH MVFR HAZE
POSSIBLE, ESPECIALLY DURING THE MORNING. RESTRICTIONS ARE POSSIBLE
IN SCATTERED STORMS LATE SATURDAY AND AGAIN ON SUNDAY AS A FRONT
SAGS SOUTHWARD THROUGH THE REGION. VFR CONDITIONS WILL RETURN ON
MONDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR OHZ039>041-
048>050-057>059-068-069.
HEAT ADVISORY FROM NOON TO 7 PM EDT THURSDAY FOR OHZ039>041-
048>050-057>059-068-069.
PA...HEAT ADVISORY FROM NOON TO 7 PM EDT THURSDAY FOR PAZ013-014-
020>022-029-031-073-075.
WV...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR WVZ001>004-012-
021>023.
HEAT ADVISORY FROM NOON TO 7 PM EDT THURSDAY FOR WVZ001>004-
012-021>023.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1240 PM EDT WED JUL 4 2012
.SYNOPSIS...
IT WILL BE GETTING HOT AND HUMID THIS HOLIDAY AFTERNOON, UNTIL A
BAND OF THUNDERSTORMS BLOWS THROUGH WITH POTENTIALLY DAMAGING
WIND, HAIL, HEAVY DOWNPOURS AND FREQUENT LIGHTNING. THE
THUNDERSTORMS WILL DECREASE TO NO MORE THAN SCATTERED COVERAGE
THIS EVENING. BROAD HIGH PRESSURE WILL MAINTAIN HOT AND HUMID
CONDITIONS ACROSS THE UPPER OHIO VALLEY INTO SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
HAVE CONTINUED MENTION OF LIKELY THUNDERSTORMS THIS HOLIDAY AFTERNOON, WITH
POTENTIAL FOR DAMAGING WIND, LARGE HAIL, HEAVY DOWNPOURS, AND
FREQUENT LIGHTNING.
SPC GUIDANCE HAS INCLUDED THE NORTHERN HALF OF THE UPPER OHIO
VALLEY AS HAVING A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS
AFTERNOON AND EARLY EVENING.
RECENT RADAR DATA SHOWS A BAND OF THUNDERSTORMS MOVING SOUTHEASTWARD
ACROSS THE NORTHERN PENNSYLVANIA MOUNTAINS. OUTFLOW FROM THESE THUNDERSTORMS,
PLUS NORTHERLY BREEZES OFF LAKE ERIE, MAY HELP DEVELOP
THUNDERSTORMS FARTHER WEST ACROSS NORTHWESTERN PENNSYLVANIA THIS
AFTERNOON.
RECENT HRRR MODEL OUTPUT SUPPORTS THIS IDEA AS IT SHOWS
THUNDERSTORMS RAPIDLY DEVELOPING ACROSS THE NEW PHILADELPHIA-
PITTSBURGH CORRIDOR BETWEEN BEFORE 3 PM, AND THEN MOVING SOUTH PAST
THE I-70 AND I-68 CORRIDORS BY EARLY EVENING. ITS STILL POSSIBLE
THE I-80 CORRIDOR SEES DEVELOPMENT EARLIER.
ALL THESE STORMS WILL HAVE PLENTY OF POTENTIAL ENERGY TO WORK
WITH, DUE TO THE HUMID CONDITIONS, AND SUFFICIENT VERTICAL SHEAR
TO BECOME SEVERE.
HEAVY RAINS WITH THE STORMS MAY CAUSE FLOODING IF RAIN AMOUNTS
EXCEED 2 INCHES IN LESS THAN 2 HOURS.
THUNDERSTORM WILL HAVE A DRAMATIC EFFECT ON TEMPERATURES. SO
FORECAST OF HIGHS THIS AFTERNOON IS COMPLICATED. MADE BEST
JUDGMENT BASED ON OUR HUNCH OF WHEN AND WHERE THUNDERSTORMS
DEVELOP.
HEAT ADVISORIES MAINTAINED BUT HIGH TEMPERATURES COULD COME SHORT
DUE TO CLOUDS AND THUNDERSTORMS.
EXPECT THUNDERSTORM COVERAGE TO DECREASE THIS EVENING, AND BE GONE AFTER
MIDNIGHT. WILL CONSIDER FOG PROSPECTS WITH LATER FORECAST
ISSUANCES, BASED ON RAINFALL PATTERNS.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
RECENT SREF MODEL OUTPUT CONTINUES TO SHOW THE BROAD HIGH PRESSURE
ACROSS THE EASTERN AND CENTRAL U.S. STRENGTHENING THURSDAY AND
FRIDAY, THEN SHRINKING SOUTH SATURDAY.
THE MAIN EFFECT OF THE HIGH PRESSURE WILL BE TO CONTINUE THE HOT
HUMID CONDITIONS, WITH GFS, NAM, AND ECMWF MOS SHOWING THURSDAY
AND FRIDAY HAVING THE HIGHEST AFTERNOON TEMPERATURES. AS THE HIGH
PRESSURE SHRINKS SOUTH SATURDAY, HIGH TEMPERATURES SATURDAY MAY BE
A COUPLE DEGREES LOWER THAN FRIDAY. HOWEVER, HUMID CONDITIONS WILL
PERSIST.
SO HAVE ADDED A HEAT ADVISORY FOR THURSDAY FOR MOST OF THE UPPER
OHIO VALLEY, EXCEPT THE APPALACHIAN MOUNTAINS AND I-80 CORRIDOR.
IN HAZARDOUS WEATHER OUTLOOK HAVE MENTIONED HEAT INDICES WELL INTO
THE 90S FRIDAY AND POSSIBLY SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
THERE IS GFS/ECMWF ENSEMBLE AGREEMENT TO BEGIN THE PERIOD THAT DEEP
RIDGING WILL BE CENTERED ACROSS THE MISSOURI VALLEY. THE UPPER OHIO
VALLEY WILL BE IN A NORTHWESTERLY FLOW ON THE EASTERN PERIPHERY OF THE
RIDGE. THE MODEL CONSENSUS INDICATES AN AMPLIFYING TREND WITH THE
RIDGE DOMINATING THE WESTERN TWO THIRDS OF THE CONUS AND LOWERING
MID-LEVEL HEIGHTS ACROSS THE UPPER OHIO VALLEY AS A TROUGH BUILDS
INTO THE NORTHEAST.
AFTER A COLD FRONT DROPS SOUTHEAST ACROSS THE AREA AND BRINGS
CHANCE POPS ON SUNDAY, A DRIER AND COOLER FORECAST IS IN PLACE FOR
EARLY NEXT WEEK. HAVE GONE DRY OR WITH SILENT SLIGHT CHC POPS FOR
LOWERING HEIGHTS THROUGH WEDNESDAY. UNCERTAINTY ENTERS THE FORECAST
BY NEXT THURSDAY WITH THE POTENTIAL OF A MID-LEVEL TROUGH PUSHING
FROM THE UPPER MIDWEST SOUTHEASTWARD ACROSS THE AREA. TEMPS ARE
AROUND 5 DEGREES ABOVE NORMAL AHEAD OF THE FRONT ON SUNDAY. TEMPS
THEN COOL TO AROUND NORMAL SEASONAL VALUES BY TUESDAY AND WEDNESDAY.
&&
.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
SCATTERED SHOWERS AND THUNDERSTORMS WILL DROP SOUTHWARD ACROSS THE
TERMINALS THIS AFTERNOON INTO THE EVENING. A FEW OF THE STORMS MAY BE
STRONG TO SEVERE WITH GUSTY WINDS AND HAIL. TEMPO GROUPS ARE
FORECAST ACROSS THE TERMINALS FOR VISIBILITY RESTRICTIONS WITH
THUNDERSTORMS. THE BEST WINDOW LOOKS TO BE STARTING AROUND 17Z AT
KFKL/KDUJ...BY 19Z FOR KPIT/KBVI/KAGC/KHLG/KLBE AND AROUND 21Z AT
KMGW. ASIDE FROM THUNDERSTORMS, PREVAILING WINDS WILL BE
SOUTHWESTERLY AT AROUND 10 KTS TODAY.
SHOWERS AND THUNDERSTORMS WILL DIMINISH OVERNIGHT. ABUNDANT SURFACE
MOISTURE, ESPECIALLY AT THE TERMINALS WHICH RECEIVE HEAVY RAINFALL
FROM THUNDERSTORMS, WILL ALLOW FOR SOME PRE-DAWN FOG TO DEVELOP ON
THURSDAY MORNING.
OUTLOOK...THURSDAY NIGHT THROUGH MONDAY...
MOSTLY VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD WITH MVFR HAZE
POSSIBLE, ESPECIALLY DURING THE MORNING. RESTRICTIONS ARE POSSIBLE
IN SCATTERED STORMS LATE SATURDAY AND AGAIN ON SUNDAY AS A FRONT
SAGS SOUTHWARD THROUGH THE REGION. VFR CONDITIONS WILL RETURN ON
MONDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR OHZ039>041-
048>050-057>059-068-069.
HEAT ADVISORY FROM NOON TO 7 PM EDT THURSDAY FOR OHZ039>041-
048>050-057>059-068-069.
PA...HEAT ADVISORY FROM NOON TO 7 PM EDT THURSDAY FOR PAZ013-014-
020>022-029-031-073-075.
WV...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR WVZ001>004-012-
021>023.
HEAT ADVISORY FROM NOON TO 7 PM EDT THURSDAY FOR WVZ001>004-
012-021>023.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1137 AM EDT WED JUL 4 2012
.SYNOPSIS...
IT WILL BE GETTING HOT AND HUMID THIS HOLIDAY AFTERNOON, UNTIL A
BAND OF THUNDERSTORMS BLOWS THROUGH WITH POTENTIALLY DAMAGING
WIND, HAIL, HEAVY DOWNPOURS AND FREQUENT LIGHTNING. THE
THUNDERSTORMS WILL DECREASE TO NO MORE THAN SCATTERED COVERAGE
THIS EVENING. BROAD HIGH PRESSURE WILL MAINTAIN HOT AND HUMID
CONDITIONS ACROSS THE UPPER OHIO VALLEY INTO SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
HAVE ADDED MENTION OF LIKELY THUNDERSTORMS THIS HOLIDAY AFTERNOON,
WITH POTENTIAL FOR DAMAGING WIND, LARGE HAIL, HEAVY DOWNPOURS, AND
FREQUENT LIGHTNING. THIS IDEA BASED ON RECENT RADAR DATA SHOWING A
BAND OF THUNDERSTORMS MOVING SOUTHWARD OUT OF LAKE ERIE, AND SPC
GUIDANCE THAT HAS INCLUDED THE NORTHERN HALF OF THE UPPER OHIO
VALLEY AS HAVING A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS
AFTERNOON AND EARLY EVENING.
RECENT HRRR MODEL OUTPUT SHOWS THUNDERSTORMS RAPIDLY DEVELOPING
ACROSS THE NEW PHILADELPHIA-PITTSBURGH CORRIDOR BETWEEN 1 AND 3
PM, AND THEN MOVING SOUTH PAST THE I-70 AND I-68 CORRIDORS BY
EARLY EVENING. ITS POSSIBLE THE I-80 CORRIDOR SEES DEVELOPMENT
EARLIER FROM OUTFLOW LIFT WITH THE ERIE LAKE SHORE STORMS. ALL
THESE STORMS WILL HAVE PLENTY OF POTENTIAL ENERGY TO WORK WITH,
DUE TO THE HUMID CONDITIONS, AND SUFFICIENT VERTICAL SHEAR TO
BECOME SEVERE.
HEAVY RAINS WITH THE STORMS MAY CAUSE FLOODING IF RAIN AMOUNTS
EXCEED 2 INCHES IN LESS THAN 2 HOURS.
THUNDERSTORM WILL HAVE A DRAMATIC EFFECT ON TEMPERATURES. SO
FORECAST OF HIGHS THIS AFTERNOON IS COMPLICATED. MADE BEST
JUDGMENT BASED ON OUR HUNCH OF WHEN AND WHERE THUNDERSTORMS
DEVELOP.
HEAT ADVISORIES MAINTAINED BUT HIGH TEMPERATURES COULD COME SHORT
DUE TO CLOUDS AND THUNDERSTORMS.
EXPECT THUNDERSTORM COVERAGE TO DECREASE THIS EVENING, AND BE NONE
FORECASTED AFTER MIDNIGHT. WILL CONSIDER FOG PROSPECTS WITH LATER
FORECAST ISSUANCES, BASED ON RAINFALL PATTERNS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
SFC HIGH WILL BUILD IN FROM THE NORTH, BEHIND THE EXITING FRONT ON
THU. UL RIDGE WILL CONTINUE TO BUILD. MID-LEVEL TEMPS THU, CLOSE TO
TODAY`S, SO EXPECT ANOTHER HOT ONE. EXPECT A DROP OFF IN THE SFC
TDS WITH THE LL FLOW OUT OF THE NORTH, BUT WITH AMPLE SUNSHINE,
TEMPS COULD RISE EVEN FURTHER WITH THE DRIER LL ATMOSPHERE.
RIDGE WILL CONTINUE TO BUILD EASTWARD FRIDAY, AND WEAK SFC HIGH
WILL REMAIN OVER THE AREA. WILL LEAVE OUT MENTION OF POPS FRIDAY.
ANOTHER HOT DAY WITH HUMIDITY LEVELS RISING JUST A BIT.
WILL LIKELY BE ADDING HEAT ADVISORIES THIS PERIOD WITH LATER
FORECAST ISSUANCES.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
UPPER RIDGE IS PROJECTED TO PERSIST OVER THE MS VALLEY AND MAINTAIN
WARM TEMPERATURES OVER THE WEEKEND. FORECAST READINGS ARE CLOSE TO
HPC NUMBERS WITH DAYTIME HIGHS AROUND 10 DEGREES ABOVE NORMAL FOR
SATURDAY AND SUNDAY. MODELS SHOW THE RIDGE FLATTENING AND SHIFTING
WESTWARD EARLY NEXT WEEK WHICH SHOULD SUPPORT A DOWNWARD TEMPERATURE
TREND...WITH READINGS CLOSER TO NORMAL BY TUESDAY.
A WEAK FRONT IS PROGGED TO SAG SOUTHWARD ACROSS ACROSS THE FORECAST
AREA LATE SATURDAY AND SUNDAY...BRINGING THE RISK FOR SHOWERS AND
STORMS. THE BOUNDARY IS PROGGED TO BECOME NEARLY STATIONARY JUST TO
THE SOUTH OF THE FORECAST AREA EARLY NEXT WEEK.
&&
.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
SCATTERED SHOWERS AND THUNDERSTORMS WILL DROP SOUTHWARD ACROSS THE
TERMINALS THIS AFTERNOON INTO THE EVENING. A FEW OF THE STORMS MAY BE
STRONG TO SEVERE WITH GUSTY WINDS AND HAIL. TEMPO GROUPS ARE
FORECAST ACROSS THE TERMINALS FOR VISIBILITY RESTRICTIONS WITH
THUNDERSTORMS. THE BEST WINDOW LOOKS TO BE STARTING AROUND 17Z AT
KFKL/KDUJ...BY 19Z FOR KPIT/KBVI/KAGC/KHLG/KLBE AND AROUND 21Z AT
KMGW. ASIDE FROM THUNDERSTORMS, PREVAILING WINDS WILL BE
SOUTHWESTERLY AT AROUND 10 KTS TODAY.
SHOWERS AND THUNDERSTORMS WILL DIMINISH OVERNIGHT. ABUNDANT SURFACE
MOISTURE, ESPECIALLY AT THE TERMINALS WHICH RECEIVE HEAVY RAINFALL
FROM THUNDERSTORMS, WILL ALLOW FOR SOME PRE-DAWN FOG TO DEVELOP ON
THURSDAY MORNING.
OUTLOOK...THURSDAY NIGHT THROUGH MONDAY...
MOSTLY VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD WITH MVFR HAZE
POSSIBLE, ESPECIALLY DURING THE MORNING. RESTRICTIONS ARE POSSIBLE
IN SCATTERED STORMS LATE SATURDAY AND AGAIN ON SUNDAY AS A FRONT
SAGS SOUTHWARD THROUGH THE REGION. VFR CONDITIONS WILL RETURN ON
MONDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR OHZ039>041-
048>050-057>059-068-069.
PA...NONE.
WV...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR WVZ001>004-012-
021>023.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
135 AM EDT WED JUL 4 2012
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 430 PM EDT TUE JUL 3 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL RIDGE
FROM THE SRN ROCKIES AND CNTRL PLAINS INTO THE UPPER MS VALLEY
RESULTING IN WNW FLOW THROUGH THE NRN GREAT LAKES. A WEAK SHRTWV
MOVING THROUGH NE ND HAS TRIGGERED ANY SHRA/TSRA. AT THE SFC...LOW
PRES WAS LOCATED WEST OF JAMES BAY WITH A WEAK COLD FRONT TRAILING
SW INTO NE MN AND NE SD. THE GRADIENT REMAINED WEAK ENOUGH SO THAT
LAKE BREEZES HAVE DEVELOPED OFF OF BOTH LAKE SUPERIOR AND LAKE MI.
DESPITE T/TD CLIMBING TO NEAR 93/64 INLAND WITH MLCAPE VALUES IN THE
2K-3K J/KG RANGE...CAPPING HAS BEEN STRONG ENOUGH TO SUPPRESS
CONVECTION SO FAR WITH ONLY RELATIVELY SHALLOW CU OVER THE WEST AND
ALONG LAKE BREEZES OVER THE EAST.
TONIGHT...CANNOT RULE OUT SOME ISOLD SHRA AND POSSIBLY A TSTM OVER
THE SOUTH AND EAST THIS EVENING GIVEN THE AMOUNT OF INSTABILITY
AVBL. HOWEVER...ONLY SLIGHT CHANCE WAS MENTIONED GIVEN CURRENT
TRENDS. WITH THE LOSS OF DAYTIME HEATING...ANY REMAINING PCPN
CHANCES WILL DIMINISH/END BY LATE EVENING. EXPECT MIN TEMPS WELL
ABOVE NORMAL WITH LOWS ONLY IN THE MID TO UPPER 60S.
WED...AS A SHORTWAVE AND SFC LOW MOVE INTO CNTRL SASK...INCREASING
SRLY FLOW INTO THE UPPER MS VALLEY WILL PUSH A WARM FRONT BACK
TOWARD THE REGION. MLCAPE VALUE SHOULD AGAIN CLIMB TO NEAR 3K J/KG
NEAR THE FRONT. HOWEVER...SIMILAR TODAY...NO SIGNIFICANT SHRTWVS ARE
FCST INTO THE AREA AND CAPPING SHOULD BE STRONG ENOUGH TO LIMIT TSRA
CHANCES. SLIGHT CHANCES WERE AGAIN INCLUDED OVER THE WEST CLOSEST TO
THE WARM FRONT AND 925-850 MB THETA-E GRADIENT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 430 PM EDT TUE JUL 3 2012
ONE OF THE HOTTEST DAYS OF THE YEAR WILL BE THURSDAY...AS THE 500MB
RIDGE SETS UP ACROSS MUCH OF THE CENTRAL U.S. THE 500MB LOW OVER N
SASKATCHEWAN AND MANITOBA AT 00Z THURSDAY WILL CROSS INTO HUDSON BAY
AND N ONTARIO BY 06Z FRIDAY.
DID ADJUST TEMPS DOWN A COUPLE OF DEGREES FOR THE FAR W THROUGH THE
BARAGA PLAINS...GIVEN THE QUICKER COLD FRONT WHICH LOOKS TO BE SET
UP ACROSS THE KEWEENAW PENINSULA THROUGH IWD AND NW WI AT 12Z
TUESDAY. EXPECT THE COLD FRONT TO PUSH E...AND SET UP JUST E OF THE
CWA BY 00Z FRIDAY. DUE TO A FASTER SOLUTION DAY 2/3...THE HIGH
CHANCE POPS FOR THURSDAY NIGHT AND FRIDAY WERE PUSHED BACK TO SLIGHT
CHANCE OR DRY CONDITIONS. THERE IS MODERATE TO LOW CONFIDENCE IN
THIS SOLUTION.
WITH HIGH PRESSURE ROLLING IN FROM CENTRAL CANADA AND THE NORTHERN
PLAINS...EXPECT A SLIGHT COOL DOWN...BUT ALSO DRIER AIR TO MIX DOWN
DURING THE AFTERNOON HOURS. LOWERED DEWPOINTS THURSDAY NIGHT THROUGH
SATURDAY. AT THIS POINT THAT WOULD BRING ABOUT MIN RH VALUES INTO
THE 35 TO 45 PERCENT RANGE FOR BOTH FRIDAY AND SATURDAY. WOULD NOT
BE SURPRISED IF THEY FALL CLOSER TO OR BELOW 30 PERCENT FOR MOST
LOCATIONS...ESPECIALLY IF THE LIMITED SHOWERS STILL IN THERE FOR
FRIDAY NIGHT /THANKS TO THE WETTER ECMWF/ DO NOT PAN OUT.
OTHERWISE...TEMPS IN THE MID TO UPPER 70S LOOK TO BE THE RULE FROM
SATURDAY THROUGH NEXT TUESDAY. THE SFC HIGH SHOULD BE OVERHEAD BY
06Z SUNDAY...BEING REINFORCED BY ANOTHER HIGH PRESSURE SYSTEM
BUILDING INTO THE NORTHERN AND CENTRAL PLAINS FOR EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 133 AM EDT WED JUL 4 2012
WITH LINGERING MOIST CONDITIONS...LOOK FOR PATCHY FOG TO DEVELOP AT
ALL SITES OVERNIGHT WITH VERY LIGHT WINDS AND LOWER VBSYS TO IFR OR
EVEN LIFR. BEST SITES FOR THIS WOULD BE SAW AND CMX AND WENT WITH
LOWEST VIS THERE. IWD IS A BIT TOUGHER AND THINK FOG WILL BE
TRANSIENT OVERNIGHT THERE. FOG WILL BURN OFF EARLY WED MORNING WITH
VFR CONDITIONS CONTINUING THROUGH THE REST OF THE PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 430 PM EDT TUE JUL 3 2012
WINDS ARE EXPECTED TO REMAIN BELOW 20KTS THROUGH SATURDAY WITH A
HIGH PRESSURE RIDGE REMAINING THE DOMINANT FEATURE THROUGH MUCH OF
THE PERIOD. AREAS OF FOG...ESPECIALLY EAST...ARE EXPECTED FROM LATE
TONIGHT THROUGH EARLY FRIDAY WITH ABUNDANT LOW LEVEL MOISTURE OVER
THE REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1245 PM CDT WED JUL 4 2012
.UPDATE...
18Z AVIATION DISCUSSION ADDED BELOW.
&&
.DISCUSSION...
MAIN FORECAST ISSUE THE NEXT COUPLE OF DAYS WILL BE THE OPPRESSIVE
HEAT AND HUMIDITY. TEMPERATURES WILL BE STARTING OUT THE GATE
SEVERAL DEGREES WARMER THAN YESTERDAY...AND EXPECT AFTERNOON HIGHS
TO BE WARMER THAN YESTERDAY...ESPECIALLY IN WESTERN AREAS IN THE
VICINITY OF THERMAL RIDGE AHEAD OF SLOWLY ADVANCING COOL FRONT.
VERY WARM MID LEVELS HAVE THUS FAR KEPT CONVECTION UNDER
CONTROL...BUT THERE PERSISTS AN E-W BAND OF HIGH BASED SHOWERS AND
A FEW TSTMS ACROSS CENTRAL MN INTO WC WI ON THE NORTHERN PERIPHERY
OF MID/HIGH LEVEL MOISTURE PLUME WHICH EXTENDS FROM THE SW U.S.
THEN ACROSS MN INTO WI. HRRR HAS GENERALLY BEEN HANDLING THIS
FAIRLY WELL. EXPECT THAT IT WILL FOLLOW THE TYPICAL DIMINISHING
DIURNAL TREND DURING THE MORNING.
MAY SEE A FEW TSTMS DEVELOP THIS AFTN AND OVERNIGHT IN N CWA AND
THEN THIS EVENING IN WC MN AHEAD OF WEAK COOL FRONT. MID LEVEL
TEMPERATURES COOL SLIGHTLY IN WAKE OF COOL FRONT AS IT MOVES
ACROSS CENTRAL MN TONIGHT AND THEN INTO WC WI/S MN ON THURSDAY.
PROGRESSED LOW POPS TSTMS SOUTHEASTWARD WITH FRONT. WILL BE
BORDERLINE HEAT WARNING IN CENTRAL MN FOR THURSDAY WITH SOME
COOLING AND BIT LOWER DEWPOINTS...BUT LEFT WARNING IN FOR NOW
ALONG WITH REMAINDER OF FORECAST AREA UNTIL 10 PM THURSDAY.
CONVECTION SHOULD BECOME BETTER ORGANIZED AND MORE WIDESPREAD ON
FRIDAY INTO SATURDAY AS FAIRLY VIGOROUS SHORTWAVE MOVES THRU AND
FLATTENS RIDGE. WITH HIGH PWATS COULD SEE SOME FAIRLY SUBSTANTIAL
RAIN AMOUNTS. IF SUFFICIENT SUNSHINE...MAY APPROACH EXCESSIVE HEAT
WARNING CRITERIA AGAIN FRIDAY IN SC MN.
BY LATE IN THE WEEKEND WE GET INTO A NW FLOW PATTERN AS HOT UPPER
RIDGE RETROGRADES AND BECOMES ESTABLISHED OVER THE WESTERN STATES
GIVING US RELIEF FROM THE HEAT AND HUMIDITY. SHOULD BE A GENERALLY
DRY PATTERN...BUT SOME THREAT OF SHORTWAVES COMING DOWN RIDGE
BRINGING A FEW SHOWERS OR TSTMS...BUT NOT ENUF CONFIDENCE TO PUT
ANY PCPN INTO FORECAST AT THIS POINT.
&&
.AVIATION.../18Z TAF ISSUANCE/
COUPLE OF AREAS TO WORRY ABOUT IN TERMS OF CONVECTION LATE THIS
AFTERNOON/OVERNIGHT. THE COLD FRONT OVER THE EASTERN DAKOTAS IS
PROGGED TO MOVE INTO WESTERN MINNESOTA THIS EVENING...EXITING THE
TAF SITES AND INTO SOUTHERN MN AFTER 12Z THU. MODELS DO SUGGEST
FORCING WILL BE STRONG ENOUGH TO GENERATE SOME SCATTERED CONVECTION
WITH THIS FEATURE AS IT MOVES INTO THE REGION. OTHER POTENTIAL
AREA OF DEVELOPMENT IS ALONG AND NORTH OF THE WARM FRONT/INSTABILITY
GRADIENT OVER FAR EASTERN AREAS. WILL INTRODUCE SOME TEMPO THUNDER
OVER THE NORTHERN TAF SITES OVERNIGHT...AND A PROB30 AT KEAU AND VC
AT KMSP FOR NOW. THIS SAGS SOUTH IN THE MORNING...WITH SOME
POSSIBILITY OF CUMULUS DEVELOPMENT BEHIND FRONT IN THE MORNING...BUT
DIDNT GO MVFR WITH THAT. OTHERWISE...SOUTH/SOUTHWEST WIND A BIT
GUSTY ACROSS CENTRAL AND SOUTHERN MN AHEAD OF COLD FRONT. THEN
BECOMING NORTHWEST TO NORTH WITH FROPA INTO THURSDAY MORNING.
KMSP...CONVECTION ASSOCIATED WITH EITHER THE COLD FRONT TO THE WEST
OR COMPLEX EXPECTED TO DEVELOP LATE AFTERNOON OVER NORTHEAST MN AND
RIDE SOUTHEAST OVER WESTERN WISCONSIN. WILL TEND TO GO WITH THE
FORMER AND BEING IN VCTS AT 09Z FOR NOW. THIS IS SCHEDULED TO EXIT
TO THE SOUTH OF THE AREA THURSDAY MORNING AS THE COLD FRONT MOVES
THROUGH. SURFACE WINDS EXPECTED TO BECOME MORE SOUTHWEST AHEAD OF
THE COLD FRONT AND GUSTY TO 18-20 KNOTS POSSIBLE. THEN BECOMING
MORE SOUTH THIS EVENING AND BECOMING NW-N WITH FROPA.
//OUTLOOK...
.THURSDAY...VFR. CHC SHOWER/TSTMS...MAINLY LATE. WINDS S 10-20KT.
.FRIDAY...VFR/MVFR. CHC SHWRS/TSTMS. SHIFTING WINDS...BECOMING NE
5-10 KT.
.SATURDAY...VFR/MVFR. CHC SHWRS/TSTMS. WINDS NE 5-10 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...EXCESSIVE HEAT WARNING UNTIL 10 PM CDT THURSDAY FOR ANOKA-BENTON-
BLUE EARTH-BROWN-CARVER-CHIPPEWA-CHISAGO-DAKOTA-DOUGLAS-
FARIBAULT-FREEBORN-GOODHUE-HENNEPIN-ISANTI-KANABEC-
KANDIYOHI-LAC QUI PARLE-LE SUEUR-MARTIN-MCLEOD-MEEKER-MILLE
LACS-MORRISON-NICOLLET-POPE-RAMSEY-REDWOOD-RENVILLE-RICE-
SCOTT-SHERBURNE-SIBLEY-STEARNS-STEELE-STEVENS-SWIFT-TODD-
WASECA-WASHINGTON-WATONWAN-WRIGHT-YELLOW MEDICINE.
WI...EXCESSIVE HEAT WARNING UNTIL 10 PM CDT THURSDAY FOR BARRON-
CHIPPEWA-DUNN-EAU CLAIRE-PEPIN-PIERCE-POLK-RUSK-ST. CROIX.
&&
$$
BAP/
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
716 AM CDT WED JUL 4 2012
.UPDATE...
12Z AVIATION DISCUSSION ADDED BELOW.
&&
.DISCUSSION...
MAIN FORECAST ISSUE THE NEXT COUPLE OF DAYS WILL BE THE OPPRESSIVE
HEAT AND HUMIDITY. TEMPERATURES WILL BE STARTING OUT THE GATE
SEVERAL DEGREES WARMER THAN YESTERDAY...AND EXPECT AFTERNOON HIGHS
TO BE WARMER THAN YESTERDAY...ESPECIALLY IN WESTERN AREAS IN THE
VICINITY OF THERMAL RIDGE AHEAD OF SLOWLY ADVANCING COOL FRONT.
VERY WARM MID LEVELS HAVE THUS FAR KEPT CONVECTION UNDER
CONTROL...BUT THERE PERSISTS AN E-W BAND OF HIGH BASED SHOWERS AND
A FEW TSTMS ACORSS CENTRAL MN INTO WC WI ON THE NORTHERN PERIFERY
OF MID/HIGH LEVEL MOISTURE PLUME WHICH EXTENDS FROM THE SW U.S.
THEN ACROSS MN INTO WI. HRRR HAS GENERALLY BEEN HANDLING THIS
FAIRLY WELL. EXPECT THAT IT WILL FOLLOW THE TYPICAL DIMINISHING
DINURAL TREND DURING THE MORNING.
MAY SEE A FEW TSTMS DEVELOP THIS AFTN AND OVERNITE IN N CWA AND
THEN THIS EVENING IN WC MN AHEAD OF WEAK COOL FRONT. MID LEVEL
TEMPERATURES COOL SLIGHTLY IN WAKE OF COOL FRONT AS IT MOVES
ACROSS CENTRAL MN TONIGHT AND THEN INTO WC WI/S MN ON THURSDAY.
PROGRESSED LOW POPS TSTMS SOUTHEASTWARD WITH FRONT. WILL BE
BORDERLINE HEAT WARNING IN CENTRAL MN FOR THURSDAY WITH SOME
COOLING AND BIT LOWER DEWPOINTS...BUT LEFT WARNING IN FOR NOW
ALONG WITH REMAINDER OF FORECAST AREA UNTIL 10 PM THURSDAY.
CONVECTION SHOULD BECOME BETTER ORGANIZED AND MORE WIDESPREAD ON
FRIDAY INTO SATURDAY AS FAIRLY VIGOROUS SHORTWAVE MOVES THRU AND
FLATTENS RIDGE. WITH HIGH PWATS COULD SEE SOME FAIRLY SUBSTANTIAL
RAIN AMOUNTS. IF SUFFICIENT SUNSHINE...MAY APPROACH EXCESSIVE HEAT
WARNING CRITERIA AGAIN FRIDAY IN SC MN.
BY LATE IN THE WEEKEND WE GET INTO A NW FLOW PATTERN AS HOT UPPER
RIDGE RETROGRADES AND BECOMES ESTABLISHED OVER THE WESTERN STATES
GIVING US RELIEF FROM THE HEAT AND HUMIDITY. SHOULD BE A GENERALLY
DRY PATTERN...BUT SOME THREAT OF SHORTWAVES COMING DOWN RIDGE
BRINGING A FEW SHOWERS OR TSTMS...BUT NOT ENUF CONFIDENCE TO PUT
ANY PCPN INTO FORECAST AT THIS POINT.
&&
.AVIATION.../12Z TAF ISSUANCE/
IT TOOK UNTIL ABOUT SUNRISE...BUT PERSISTENT...THOUGH WEAK LIFT
OVER A STATIONARY FRONT BISECTING THE CENTER OF THE MPX AREA HAS
RESULTED IN THE DEVELOPMENT OF ISOLATED THUNDERSTORMS ACROSS THE
AREA THIS MORNING. OF COURSE OUT OF CONVIENIENCE...A SMALL CLUSTER
HAS DECIDED TO SET UP SHOP RIGHT IN THE DEPARTURE GATES FOR
MSP. EXPECT THIS ACTIVITY TO QUICKLY DIMINISH THIS MORNING AS WHAT
WEAK LLJ WE HAVE DIMINISHES. AFTER 15Z...NOT ANTICIPATING ANY MORE
PRECIP UNTIL POSSIBLY TONIGHT...AS THE COMBINATION OF AN
APPROACHING COLD FRONT AND THE ENHANCEMENT OF THE NOCTURNAL LLJ
MAY HELP SPUR SOME TSRA ACTIVITY INTO CENTRAL MN AND EVENTUALLY
OVER TOWARD MSP. AT THIS POINT...CONFIDENCE NOT VERY HIGH ON
IF/WHEN/WHERE ANY STORMS WOULD OCCUR TONIGHT...SO HAVE NO PRECIP
MENTION IN TAFS. AS FOR THAT COLD FRONT...FOLLOWED MORE OF AN
ECMWF TIMING FOR ITS MOVEMENT THROUGH THE AREA...WHICH IS A COUPLE
OF HOURS SLOWER THAN THE GFSLAMP. SLOWER SEEMS LIKE A BETTER PLAY
GIVEN THE STRENGTH OF THE UPPER RIDGE FROM HERE ON SOUTH. FOR
TONIGHT...IF CLOUD COVER REMAINS MINIMAL...THEN WILL HAVE TO WATCH
FOR THE DEVELOPMENT OF FG/HZ...ESPECIALLY ALONG AND AHEAD OF THE
BOUNDARY WHERE LOW LEVEL MOISTURE IS LIKELY TO POOL. AGAIN...GIVEN
ALL OF THE UNCERTAINTY WITH POTENTIAL CLOUD COVER AND
STORMS...PLAYED VSBY RESTRICTIONS FOR THU MORNING RATHER
CONSERVATIVELY.
KMSP...WILL HAVE TO DEAL WITH SOME OBSTRUCTIONS IN THE AREA OF THE
DEPARTURE GATES FOR THE FIRST HOUR OR SO...BUT AFTER THAT...MAINLY
SUNNY SKIES WILL DOMINATE UNTIL TONIGHT/THU MORNING. WITH DEEP
MIXING TODAY...WINDS WILL TURN TOWARD 200 DEGREES BY THIS
AFTERNOON AND PICK UP TO AROUND 10 KTS...WITH SOME GUSTS UP TO
AROUND 20 KTS. ABOUT 24 HOURS FROM NOW...FRONT WILL BE APPROACHING
THE CITIES...THOUGH NOT EXPECTING MUCH IN THE WAY OF ACTIVITY WITH
IT GIVEN VERY WARM TEMPERATURES ALOFT AND STRONG CAP. THOUGH
ANYTIME A FRONT COMES IN WITH THE AMOUNT OF INSTABILITY WE WILL
HAVE...ANYTHING COULD HAPPEN.
//OUTLOOK...
.THURSDAY...VFR. CHC SHOWER/TSTMS...MAINLY LATE. WINDS S 10-20KT.
.FRIDAY...VFR/MVFR. CHC SHWRS/TSTMS. SHIFTING WINDS...BECOMING NE
5-10 KT.
.SATURDAY...VFR/MVFR. CHC SHWRS/TSTMS. WINDS NE 5-10 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...EXCESSIVE HEAT WARNING UNTIL 10 PM CDT THURSDAY FOR ANOKA-BENTON-
BLUE EARTH-BROWN-CARVER-CHIPPEWA-CHISAGO-DAKOTA-DOUGLAS-
FARIBAULT-FREEBORN-GOODHUE-HENNEPIN-ISANTI-KANABEC-
KANDIYOHI-LAC QUI PARLE-LE SUEUR-MARTIN-MCLEOD-MEEKER-MILLE
LACS-MORRISON-NICOLLET-POPE-RAMSEY-REDWOOD-RENVILLE-RICE-
SCOTT-SHERBURNE-SIBLEY-STEARNS-STEELE-STEVENS-SWIFT-TODD-
WASECA-WASHINGTON-WATONWAN-WRIGHT-YELLOW MEDICINE.
WI...EXCESSIVE HEAT WARNING UNTIL 10 PM CDT THURSDAY FOR BARRON-
CHIPPEWA-DUNN-EAU CLAIRE-PEPIN-PIERCE-POLK-RUSK-ST. CROIX.
&&
$$
BAP/MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
445 AM CDT WED JUL 4 2012
.DISCUSSION...
MAIN FORECAST ISSUE THE NEXT COUPLE OF DAYS WILL BE THE OPPRESSIVE
HEAT AND HUMIDITY. TEMPERATURES WILL BE STARTING OUT THE GATE
SEVERAL DEGREES WARMER THAN YESTERDAY...AND EXPECT AFTERNOON HIGHS
TO BE WARMER THAN YESTERDAY...ESPECIALLY IN WESTERN AREAS IN THE
VICINITY OF THERMAL RIDGE AHEAD OF SLOWLY ADVANCING COOL FRONT.
VERY WARM MID LEVELS HAVE THUS FAR KEPT CONVECTION UNDER
CONTROL...BUT THERE PERSISTS AN E-W BAND OF HIGH BASED SHOWERS AND
A FEW TSTMS ACORSS CENTRAL MN INTO WC WI ON THE NORTHERN PERIFERY
OF MID/HIGH LEVEL MOISTURE PLUME WHICH EXTENDS FROM THE SW U.S.
THEN ACROSS MN INTO WI. HRRR HAS GENERALLY BEEN HANDLING THIS
FAIRLY WELL. EXPECT THAT IT WILL FOLLOW THE TYPICAL DIMINISHING
DINURAL TREND DURING THE MORNING.
MAY SEE A FEW TSTMS DEVELOP THIS AFTN AND OVERNITE IN N CWA AND
THEN THIS EVENING IN WC MN AHEAD OF WEAK COOL FRONT. MID LEVEL
TEMPERATURES COOL SLIGHTLY IN WAKE OF COOL FRONT AS IT MOVES
ACROSS CENTRAL MN TONIGHT AND THEN INTO WC WI/S MN ON THURSDAY.
PROGRESSED LOW POPS TSTMS SOUTHEASTWARD WITH FRONT. WILL BE
BORDERLINE HEAT WARNING IN CENTRAL MN FOR THURSDAY WITH SOME
COOLING AND BIT LOWER DEWPOINTS...BUT LEFT WARNING IN FOR NOW
ALONG WITH REMAINDER OF FORECAST AREA UNTIL 10 PM THURSDAY.
CONVECTION SHOULD BECOME BETTER ORGANIZED AND MORE WIDESPREAD ON
FRIDAY INTO SATURDAY AS FAIRLY VIGOROUS SHORTWAVE MOVES THRU AND
FLATTENS RIDGE. WITH HIGH PWATS COULD SEE SOME FAIRLY SUBSTANTIAL
RAIN AMOUNTS. IF SUFFICIENT SUNSHINE...MAY APPROACH EXCESSIVE HEAT
WARNING CRITERIA AGAIN FRIDAY IN SC MN.
BY LATE IN THE WEEKEND WE GET INTO A NW FLOW PATTERN AS HOT UPPER
RIDGE RETROGRADES AND BECOMES ESTABLISHED OVER THE WESTERN STATES
GIVING US RELIEF FROM THE HEAT AND HUMIDITY. SHOULD BE A GENERALLY
DRY PATTERN...BUT SOME THREAT OF SHORTWAVES COMING DOWN RIDGE
BRINGING A FEW SHOWERS OR TSTMS...BUT NOT ENUF CONFIDENCE TO PUT
ANY PCPN INTO FORECAST AT THIS POINT.
&&
.AVIATION.../06Z TAF ISSUANCE/
STNRY FRONT DRAPED ACRS CENTRAL MN THIS EVENING WILL GRADUALLY
LIFT BACK N AS A WMFNT DURG THE DAY TMRW. SMALL CHC SOME ISOLD
SHWRS/TSTMS COULD DEVELOP ALONG THE FNT IN WRN SD THAT COULD RIDE
ENE ALONG THE FNT...POSSIBLY COMING CLOSE TO KAXN-KSTC BEFORE
DAYBREAK. HOWEVER...MORE STABLE AIR AND UNFAVORABLE CONVECTIVE
TIMING PLUS LACK ANY ONGOING ACTIVITY PRECLUDE MENTION. IT SHOULD
BE NOTED THAT SOME MODELS TO TRY TO DEVELOP CONVECTION ARND 12Z.
HAVE GONE MORE OPTIMISTIC...OMITTING PRECIP ATTM...AND RUNNING
WITH BKN HIGHER CEILINGS. DID KEEP MENTION OF PRE-DAWN GROUND FOG
IN THE WI TAF SITES...ONLY DOWN TO MVFR. OTHERWISE...VFR CONDS
WILL PREVAIL THROUGH THE DAY WITH LESSENING CLOUD COVER AS THE DAY
PROGRESSES. LGT/VRBL WINDS EARLY ON IN THE TAF PERIOD WILL BECOME
SE TO S DURG THE DAY AND EVEN A LITTLE GUSTY BY MID-AFTN BEFORE
SETTLING DOWN ARND SUNSET.
MSP...VFR CONDS THROUGHOUT THE TAF. PRECIP CHCS TOO LOW AND
LOCATION OF ANY DEVELOPMENT LOOKS TO BE TOO FAR N TO IMPACT MSP.
MAINLY HIGH CLOUDS TO PASS OVER THE TERMINAL WITH LITTLE TO NO
OPERATIONAL IMPACT. AFTER LGT/VRBL WINDS THIS MRNG...WINDS WILL
BECOME PREDOMINANTLY SLY THIS AFTN WITH GUSTS UP TO ARND 15 KT.
WINDS THEN SETTLE DOWN TNGT. NO SIGNIFICANT CHC FOR PRECIP EVEN
INTO THU MRNG.
OUTLOOK...
.THURSDAY...VFR. CHC SHOWER/TSTMS AFTERNOON/EVENING .WINDS S
10-20KT.
.FRIDAY...VFR/MVFR. CHC SHWRS/TSTMS. SHIFTING WINDS...BECOMING NE
5-10 KT.
.SATURDAY...VFR/MVFR. CHC SHWRS/TSTMS. WINDS NE 5-10 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...EXCESSIVE HEAT WARNING UNTIL 10 PM CDT THURSDAY FOR ANOKA-BENTON-
BLUE EARTH-BROWN-CARVER-CHIPPEWA-CHISAGO-DAKOTA-DOUGLAS-
FARIBAULT-FREEBORN-GOODHUE-HENNEPIN-ISANTI-KANABEC-
KANDIYOHI-LAC QUI PARLE-LE SUEUR-MARTIN-MCLEOD-MEEKER-MILLE
LACS-MORRISON-NICOLLET-POPE-RAMSEY-REDWOOD-RENVILLE-RICE-
SCOTT-SHERBURNE-SIBLEY-STEARNS-STEELE-STEVENS-SWIFT-TODD-
WASECA-WASHINGTON-WATONWAN-WRIGHT-YELLOW MEDICINE.
WI...EXCESSIVE HEAT WARNING UNTIL 10 PM CDT THURSDAY FOR BARRON-
CHIPPEWA-DUNN-EAU CLAIRE-PEPIN-PIERCE-POLK-RUSK-ST. CROIX.
&&
$$
BAP/MPG
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
325 PM CDT WED JUL 4 2012
.DISCUSSION...
A COLD FRONT HAS BECOME STATIONARY FROM NEAR KOGA TO KTIF TO NEAR
KANW. THE FRONT IS EXPECTED TO BECOME THE FOCUS FOR ISOLATED TO
PERHAPS SCATTERED STRONG/SEVERE SLOW MOVING TSTMS LATE THIS AFTN
AND THIS EVENING. STORM DEVELOPMENT IS UNDERWAY. WEAKLY SHEARED
ENVIRONMENTAL WINDS AND DEEP VERTICAL MIXING SUGGEST THE
POTENTIAL FOR WIND DAMAGE AND HEAT BURSTS. THE HRRR INDICATES
PRECIPITABLE WATER NEAR OR ABOVE 1.5 INCHES SUPPORTING LOCALLY
HEAVY RAINFALL.
STORM ACTIVITY IS EXPECTED TO DEVELOP SOUTHEAST AND POSSIBLY
MERGE WITH ACTIVITY FCST TO SPREAD EAST THROUGH COLO AND INTO KS
LATE TONIGHT BEFORE DISSIPATING AFTER MIDNIGHT. THUS MOTHER NATURE
HAS ITS OWN FIRE WORKS SHOW PLANNED THIS EVENING AND VERY DRY AND
DUSTY CONDITIONS WILL SUPPORT STORMS CAPABLE OF DANGEROUS
LIGHTNING FOR ANYONE ATTENDING OUTDOOR EVENTS THIS EVENING.
THE STATIONARY FRONT IS EXPECTED TO LIFT NORTHWEST THURSDAY AND
THURSDAY NIGHT. TEMPERATURES ALONG AND SOUTH OF THE FRONT SHOULD
RISE INTO THE 100S ONCE AGAIN. NORTH OF THE FRONT ISOLATED TSTMS
MAY DEVELOP ACROSS NORTHWEST NEB ASSOCIATED WITH A PLUME OF
SUBTROPICAL MOISTURE AND WEAK PERTURBATIONS ROTATING NORTH AROUND
THE H500 MB RIDGE.
ANOTHER COLD FRONT WILL PUSH DOWN INTO THE FCST AREA FRIDAY
PRODUCING VERY WARM HIGHS SOUTH OF THE FRONT. THE NAM SUGGESTED
106 AT KONL AND THIS MIGHT NOT BE TOO FAR OFF THE MARK. FOR NOW
WILL FCST 104 AT KONL. NO PROBLEM WITH THE 102 FCST BY THE NAM AT
KLBF FOR FRIDAY. BASED ON THE TEMPERATURES THIS AFTN...105 AT KLBF
SO FAR...LATER FCSTS MAY HAVE TO MARK UP HIGHS FRIDAY. THE NAM AND
ECM ARE VERY DRY WITH THIS FRONT AND THE FCST FOLLOWS THE DRIER
SOLNS. THE HEAT ADVISORY HAS BEEN EXTENDED THROUGH FRIDAY.
THE UPPER LEVEL RIDGE CURRENTLY CENTERED OVER CNTL MISSOURI IS
FCST BUILD SLOWLY WEST FRIDAY THROUGH SUNDAY AND BE CENTERED OVER
UTAH BY MONDAY SETTING UP A NORTHWEST FLOW ALOFT THROUGHOUT THE
FCST AREA. THIS SHOULD HELP DRIVE A SIGNIFICANT COLD FRONT THROUGH
THE FCST AREA AND INTO KS FRIDAY FOR A SEMI PERMANENT COOL DOWN
LASTING SATURDAY THROUGH WEDNESDAY. HIGHS DURING THIS TIME PERIOD
SHOULD REMAIN NEAR NORMAL.
RAIN CHANCES ARE UNCERTAIN SUNDAY THROUGH WEDNESDAY BUT SEVERAL KEY
INGREDIENTS COULD CONSPIRE TO PRODUCE RAIN. THEY ARE UPSLOPE LOW
LEVEL MOISTURE FLOW...LOWER HEIGHTS ALOFT PRODUCING A WEAKER CAP
AND THE VERY UNCERTAIN POSSIBILITY OF DISTURBANCES DROPPING
SOUTHEAST OUT OF THE NRN PLAINS PRODUCING ISOLATED TO SCATTERED
STORM COVERAGE DAILY. THE GENERAL CONSENSUS BETWEEN THE ECM AND
GFS SUGGESTED THE BEST CHANCE OF RAIN WOULD GENERALLY BE ALONG
AND WEST OF HIGHWAY 61.
&&
.AVIATION...
VERY WEAK COLD FRONT SAGGING SOUTH ACROSS THE AREA. WINDS OUT OF
THE SOUTH ACROSS SW TO N CENTRAL NEBRASKA...SOUTH OF THE
BOUNDARY...WHILE WINDS BECOME NORTHERLY BEHIND THE FRONT. VFR
CONDITIONS EXPECT ON EITHER SIDE OF THE FRONT...WHICH STALLS
ACROSS THE AREA TOMORROW. ALONG AND SOUTH OF THE FRONT EXPECT SOME
ISOLD TO SCT SHOWERS AND THUNDERSTORMS. HAVE INCLUDED SHRA AT KLBF
HOWEVER WAS NOT CONFIDENT ENOUGH TO INCLUDE THUNDER YET. DID WANT
TO MENTION THE -SHRA TO ALSO INCLUDE THE POTENTIAL OF GUSTY WINDS
WHICH ARE LIKELY WITH THE HIGH BASED SHOWERS.
&&
.CLIMATE...
THIS IS THE THIRD DAY IN A ROW OF 100 PLUS TEMPERATURES AT NORTH
PLATTE. THIS STREAK IS FORECAST TO CONTINUE THROUGH FRIDAY WHICH
WOULD RIVAL THE GREAT HEAT WAVES OF 1934 (13 DAYS)...1935 (5
DAYS)...1936 (6 DAYS) AND 1955 (5 DAYS).
&&
.LBF WATCHES/WARNINGS/ADVISORIES...HEAT ADVISORY UNTIL 9 PM CDT
FRIDAY FOR NEZ005>010-025>029-037-038-059-070-071.
&&
$$
SHORT TERM/EXTENDED...CDC
AVIATION...MASEK
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
115 PM CDT WED JUL 4 2012
.AVIATION...
VERY WEAK COLD FRONT SAGGING SOUTH ACROSS THE AREA. WINDS OUT OF
THE SOUTH ACROSS SW TO N CENTRAL NEBRASKA...SOUTH OF THE
BOUNDARY...WHILE WINDS BECOME NORTHERLY BEHIND THE FRONT. VFR
CONDITIONS EXPECT ON EITHER SIDE OF THE FRONT...WHICH STALLS
ACROSS THE AREA TOMORROW. ALONG AND SOUTH OF THE FRONT EXPECT SOME
ISOLD TO SCT SHOWERS AND THUNDERSTORMS. HAVE INCLUDED SHRA AT KLBF
HOWEVER WAS NOT CONFIDENT ENOUGH TO INCLUDE THUNDER YET. DID WANT
TO MENTION THE -SHRA TO ALSO INCLUDE THE POTENTIAL OF GUSTY WINDS
WHICH ARE LIKELY WITH THE HIGH BASED SHOWERS.
&&
.PREV DISCUSSION... /ISSUED 959 AM CDT WED JUL 4 2012/
UPDATE...
ANOTHER UPDATE IS OUT. WITH DEEP VERTICAL MIXING TO 700 MB AND
ELEVATED CAPE THIS AFTN AND THIS EVENING...GUSTY WINDS COULD
DEVELOP WITH ANY STORMS WHICH FIRE ACROSS PARTS OF WRN AND NCNTL NEB.
ALSO...PRECIPITABLE WATER IS FCST TO POOL ABOVE 1.5 INCHES ACROSS
PARTS OF NCNTL NEB SUGGESTING LOCALLY HEAVY RAINFALL. SO GUSTY
WINDS AND LOCALLY HEAVY RAINFALL HAVE BEEN ADDED TO PARTS OF NCNTL
NEB THIS AFTN AND THIS EVENING.
PREV DISCUSSION... /ISSUED 909 AM CDT WED JUL 4 2012/
UPDATE...
A LOOK AT THE KLBF UA SOUNDING SHOWED A FCST HIGH NEAR 104 THIS
AFTN WITH MIXING TO 650 MB. THIS IS 50 MB HIGHER THAN YESTERDAY
AND THAT SOUNDING FCST A HIGH OF 104 ALSO. WE REACHED 102 TUESDAY
AFTERNOON. THUS THE SOUNDING MAY BE OVER-FCSTING THE HIGH
TEMPERATURE THIS AFTN.
MEANWHILE THE SUPER-ENSEMBLE TEMP FCST PROCEDURE SUGGESTED 103 FOR
A HIGH AT LBF WITH A RANGE OF MID 90S TO 106 IN THE RAP MODEL. THE
FCST FOLLOWS THE SUPER ENSEMBLE FOR HIGHS IN THE LOW 100S AHEAD OF
A COLD FRONT CURRENTLY MOVING THROUGH SWRN SD. NOTE THAT NO
SIGNIFICANT ADJUSTMENTS WERE MADE TO FCST HIGHS ACROSS THE
NORTHWEST ZONES WHERE A FRONT SHOULD MOVE THROUGH THIS MORNING. A
SLIGHT UPWARD ADJUSTMENT WAS MADE TO TEMPERATURES ACROSS AREAS
AHEAD OF THE FRONT IN NCNTL NEB.
PREV DISCUSSION... /ISSUED 307 AM CDT WED JUL 4 2012/
DISCUSSION...THE CONTINUED HEAT...FIRE WEATHER...AND TSTM
CHANCES ARE THE MAIN CONCERNS THE NEXT SEVERAL DAYS.
FOR TODAY...A COLD FRONT WILL BE DRIVEN SOUTH INTO NEBRASKA AS A
STRONG AREA OF LOW PRESSURE TRACKS ACROSS CENTRAL CANADA. SREF/NAM
AGREE THAT THIS FRONT WILL STALL OUT BY AFTERNOON FROM NEAR OR JUST
WEST OF ONEILL...TO AROUND NORTH PLATTE AND IMPERIAL. SOUNDINGS
TO INDICATE THAT THE CAP/CIN SHOULD ERODE DURING THE AFTERNOON
ALONG AND JUST AHEAD OF THE BOUNDARY. EXPECTING AT LEAST A FEW
TSTMS WILL FIRE NEAR THE FRONT. AGAIN TODAY HOWEVER...THESE STORMS
WILL BE HIGH BASED AS LCL/S WILL BE AROUND 10000 FT AGL. SREF IS
HINTING AT SOME POOLING OF MOISTURE/DEW POINTS INVOF OF THE FRONT
HOWEVER...SO IF STORMS COULD TAP INTO THAT MOISTURE BASES COULD BE
LOWER. FOR NOW THOUGH...EXPECTING MOSTLY HIGH BASED STORMS. AS HAS
BEEN THE CASE THE LAST FEW DAYS...THESE TYPES OF STORMS HAVE BEEN
RESPONSIBLE FOR GUSTY WINDS AND DANGEROUS CLOUD TO GROUND
LIGHTNING...BUT NOT A LOT IN THE WAY OF RAINFALL. WILL HAVE TO
WATCH FOR POTENTIAL GRASS FIRES IN AREAS WHERE LITTLE RAIN OCCURS
WITH THE STORMS. AS FAR AS SEVERE POTENTIAL...NOT EXPECTING MUCH.
RATHER WEAK SHEAR NOTED...BUT DO HAVE SOME RESPECTABLE MID LEVEL
LAPSE RATES. AS STATED EARLIER...MAY SEE SOME GUSTY WINDS THAT
COULD REACH NEAR SEVERE CRITERIA...BUT THE HAIL THREAT IS LOW.
OTHERWISE WILL CONTINUE THE HEAT ADVISORY FOR TODAY. EVEN THOUGH
TEMPS COULD BE A COUPLE OF DEGREES COOLER WITH THE FRONT PUSHING
SOUTH...INCREASING DEW POINTS WILL PUSH HEAT INDEXES UP INTO THE
100 DEGREE RANGE.
CHANCE FOR A FEW TSTMS AGAIN THURSDAY...WITH MUCH THE SAME SCENARIO
AS TODAY...WITH WEAKLY SHEARED HIGH BASED MULTICELL TSTMS POSSIBLE
DURING THE AFTERNOON INVOF STALLED FRONT ACROSS NORTHERN NEBRASKA.
CONTINUED HOT WEATHER...ESPECIALLY ALONG AND SOUTH OF THE
AFOREMENTIONED FRONTAL BOUNDARY.
FRONT SURGES BACK NORTH INTO SOUTHERN SD FRIDAY...WITH HIGHS MOST
AREAS AT OR NEAR 100 DEGREES. RATHER BREEZY SOUTH WINDS EXPECTED AS
WELL.
PATTERN SHIFT LOOKS TO BEGIN SATURDAY...AS THE LARGE UPPER LEVEL
RIDGE OF HIGH PRESSURE MIGRATES WEST FROM THE CENTRAL PLAINS INTO
THE ROCKIES. THIS SHOULD ALLOW FOR COOLING TEMPERATURES
ALOFT...ALLOWING FOR MORE ORGANIZED TSTM ACTIVITY ALONG A FRONTAL
BOUNDARY MOVING SLOWLY SOUTH THROUGH THE PLAINS SUNDAY THROUGH
TUESDAY. OTHER BIG STORY WILL BE HIGHS COOLING INTO THE 80S BY THE
FIRST OF NEXT WEEK.
FIRE WEATHER...HOT WEATHER WILL CONTINUE OVER WESTERN AND NORTH
CENTRAL NEBRASKA INTO THIS WEEKEND. ALTHOUGH RELATIVE HUMIDITY AND
WIND ARE NOT EXPECTED TO CROSS THE CRITICAL FIRE
THRESHOLDS...VEGETATION WILL CONTINUE LOSING MOISTURE EACH DAY.
LIGHTNING IS STILL POSSIBLE WITH ISOLATED THUNDERSTORMS AND IS
EXPECTED TO BE A PROBLEM IN THE SANDHILLS AND THE SOUTHWEST. WITH
THAT...ADDED TO EXTENSIVE USE OF FIREWORKS...FIRE HAS BEEN AND
WILL CONTINUE TO BE A THREAT THROUGH THE DAY TODAY. EVEN AFTER
TODAY...ISOLATED THUNDERSTORMS AND THE ASSOCIATED LIGHNING AND
ERRATIC WIND WILL CONTINUE TO PRESENT A FIRE MANAGEMENT PROBLEM.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...HEAT ADVISORY UNTIL 9 PM CDT
THURSDAY FOR NEZ005>010-025>029-037- 038-059-070-071.
&&
$$
AVIATION...MASEK
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
959 AM CDT WED JUL 4 2012
.UPDATE...
ANOTHER UPDATE IS OUT. WITH DEEP VERTICAL MIXING TO 700 MB AND
ELEVATED CAPE THIS AFTN AND THIS EVENING...GUSTY WINDS COULD
DEVELOP WITH ANY STORMS WHICH FIRE ACROSS PARTS OF WRN AND NCNTL NEB.
ALSO...PRECIPITABLE WATER IS FCST TO POOL ABOVE 1.5 INCHES ACROSS
PARTS OF NCNTL NEB SUGGESTING LOCALLY HEAVY RAINFALL. SO GUSTY
WINDS AND LOCALLY HEAVY RAINFALL HAVE BEEN ADDED TO PARTS OF NCNTL
NEB THIS AFTN AND THIS EVENING.
&&
.PREV DISCUSSION... /ISSUED 909 AM CDT WED JUL 4 2012/
UPDATE...
A LOOK AT THE KLBF UA SOUNDING SHOWED A FCST HIGH NEAR 104 THIS
AFTN WITH MIXING TO 650 MB. THIS IS 50 MB HIGHER THAN YESTERDAY
AND THAT SOUNDING FCST A HIGH OF 104 ALSO. WE REACHED 102 TUESDAY
AFTERNOON. THUS THE SOUNDING MAY BE OVER-FCSTING THE HIGH
TEMPERATURE THIS AFTN.
MEANWHILE THE SUPER-ENSEMBLE TEMP FCST PROCEDURE SUGGESTED 103 FOR
A HIGH AT LBF WITH A RANGE OF MID 90S TO 106 IN THE RAP MODEL. THE
FCST FOLLOWS THE SUPER ENSEMBLE FOR HIGHS IN THE LOW 100S AHEAD OF
A COLD FRONT CURRENTLY MOVING THROUGH SWRN SD. NOTE THAT NO
SIGNIFICANT ADJUSTMENTS WERE MADE TO FCST HIGHS ACROSS THE
NORTHWEST ZONES WHERE A FRONT SHOULD MOVE THROUGH THIS MORNING. A
SLIGHT UPWARD ADJUSTMENT WAS MADE TO TEMPERATURES ACROSS AREAS
AHEAD OF THE FRONT IN NCNTL NEB.
PREV DISCUSSION... /ISSUED 640 AM CDT WED JUL 4 2012/
AVIATION...
UNRESTRICTED FLIGHT CONDITIONS ARE EXPECTED OVER WESTERN
NEBRASKA THROUGH THIS AFTERNOON. ISOLATED THUNDERSTORMS...WITH
THE USUAL RISK OF LIGHTNING AND STRONG DOWNBURST WIND...ARE EXPECTED
OVER THE SANDHILLS AND PARTS OF SOUTHWEST NEBRASKA LATE THIS
AFTERNOON AND THIS EVENING. STORMS THAT DEVELOP WILL MOST LIKELY
FORM SOUTH OF A VTN-MHN-AIA LINE. THE PROBABILITY IS 35 PERCENT OR
LOWER IN THE AREA...SO WE HAVE NOT INCLUDED THUNDER IN THE TERMINAL
FORECASTS FOR LBF AND VTN.
PREV DISCUSSION... /ISSUED 307 AM CDT WED JUL 4 2012/
DISCUSSION...THE CONTINUED HEAT...FIRE WEATHER...AND TSTM
CHANCES ARE THE MAIN CONCERNS THE NEXT SEVERAL DAYS.
FOR TODAY...A COLD FRONT WILL BE DRIVEN SOUTH INTO NEBRASKA AS A
STRONG AREA OF LOW PRESSURE TRACKS ACROSS CENTRAL CANADA. SREF/NAM
AGREE THAT THIS FRONT WILL STALL OUT BY AFTERNOON FROM NEAR OR JUST
WEST OF ONEILL...TO AROUND NORTH PLATTE AND IMPERIAL. SOUNDINGS
TO INDICATE THAT THE CAP/CIN SHOULD ERODE DURING THE AFTERNOON
ALONG AND JUST AHEAD OF THE BOUNDARY. EXPECTING AT LEAST A FEW
TSTMS WILL FIRE NEAR THE FRONT. AGAIN TODAY HOWEVER...THESE STORMS
WILL BE HIGH BASED AS LCL/S WILL BE AROUND 10000 FT AGL. SREF IS
HINTING AT SOME POOLING OF MOISTURE/DEW POINTS INVOF OF THE FRONT
HOWEVER...SO IF STORMS COULD TAP INTO THAT MOISTURE BASES COULD BE
LOWER. FOR NOW THOUGH...EXPECTING MOSTLY HIGH BASED STORMS. AS HAS
BEEN THE CASE THE LAST FEW DAYS...THESE TYPES OF STORMS HAVE BEEN
RESPONSIBLE FOR GUSTY WINDS AND DANGEROUS CLOUD TO GROUND
LIGHTNING...BUT NOT A LOT IN THE WAY OF RAINFALL. WILL HAVE TO
WATCH FOR POTENTIAL GRASS FIRES IN AREAS WHERE LITTLE RAIN OCCURS
WITH THE STORMS. AS FAR AS SEVERE POTENTIAL...NOT EXPECTING MUCH.
RATHER WEAK SHEAR NOTED...BUT DO HAVE SOME RESPECTABLE MID LEVEL
LAPSE RATES. AS STATED EARLIER...MAY SEE SOME GUSTY WINDS THAT
COULD REACH NEAR SEVERE CRITERIA...BUT THE HAIL THREAT IS LOW.
OTHERWISE WILL CONTINUE THE HEAT ADVISORY FOR TODAY. EVEN THOUGH
TEMPS COULD BE A COUPLE OF DEGREES COOLER WITH THE FRONT PUSHING
SOUTH...INCREASING DEW POINTS WILL PUSH HEAT INDEXES UP INTO THE
100 DEGREE RANGE.
CHANCE FOR A FEW TSTMS AGAIN THURSDAY...WITH MUCH THE SAME SCENARIO
AS TODAY...WITH WEAKLY SHEARED HIGH BASED MULTICELL TSTMS POSSIBLE
DURING THE AFTERNOON INVOF STALLED FRONT ACROSS NORTHERN NEBRASKA.
CONTINUED HOT WEATHER...ESPECIALLY ALONG AND SOUTH OF THE
AFOREMENTIONED FRONTAL BOUNDARY.
FRONT SURGES BACK NORTH INTO SOUTHERN SD FRIDAY...WITH HIGHS MOST
AREAS AT OR NEAR 100 DEGREES. RATHER BREEZY SOUTH WINDS EXPECTED AS
WELL.
PATTERN SHIFT LOOKS TO BEGIN SATURDAY...AS THE LARGE UPPER LEVEL
RIDGE OF HIGH PRESSURE MIGRATES WEST FROM THE CENTRAL PLAINS INTO
THE ROCKIES. THIS SHOULD ALLOW FOR COOLING TEMPERATURES
ALOFT...ALLOWING FOR MORE ORGANIZED TSTM ACTIVITY ALONG A FRONTAL
BOUNDARY MOVING SLOWLY SOUTH THROUGH THE PLAINS SUNDAY THROUGH
TUESDAY. OTHER BIG STORY WILL BE HIGHS COOLING INTO THE 80S BY THE
FIRST OF NEXT WEEK.
FIRE WEATHER...HOT WEATHER WILL CONTINUE OVER WESTERN AND NORTH
CENTRAL NEBRASKA INTO THIS WEEKEND. ALTHOUGH RELATIVE HUMIDITY AND
WIND ARE NOT EXPECTED TO CROSS THE CRITICAL FIRE
THRESHOLDS...VEGETATION WILL CONTINUE LOSING MOISTURE EACH DAY.
LIGHTNING IS STILL POSSIBLE WITH ISOLATED THUNDERSTORMS AND IS
EXPECTED TO BE A PROBLEM IN THE SANDHILLS AND THE SOUTHWEST. WITH
THAT...ADDED TO EXTENSIVE USE OF FIREWORKS...FIRE HAS BEEN AND
WILL CONTINUE TO BE A THREAT THROUGH THE DAY TODAY. EVEN AFTER
TODAY...ISOLATED THUNDERSTORMS AND THE ASSOCIATED LIGHNING AND
ERRATIC WIND WILL CONTINUE TO PRESENT A FIRE MANAGEMENT PROBLEM.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...HEAT ADVISORY UNTIL 9 PM CDT THURSDAY FOR NEZ005>010-025>029-037-
038-059-070-071.
&&
$$
SHORT TERM/EXTENDED...CDC
AVIATION...MASEK
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
909 AM CDT WED JUL 4 2012
.UPDATE...
A LOOK AT THE KLBF UA SOUNDING SHOWED A FCST HIGH NEAR 104 THIS
AFTN WITH MIXING TO 650 MB. THIS IS 50 MB HIGHER THAN YESTERDAY
AND THAT SOUNDING FCST A HIGH OF 104 ALSO. WE REACHED 102 TUESDAY
AFTERNOON. THUS THE SOUNDING MAY BE OVER-FCSTING THE HIGH
TEMPERATURE THIS AFTN.
MEANWHILE THE SUPER-ENSEMBLE TEMP FCST PROCEDURE SUGGESTED 103 FOR
A HIGH AT LBF WITH A RANGE OF MID 90S TO 106 IN THE RAP MODEL. THE
FCST FOLLOWS THE SUPER ENSEMBLE FOR HIGHS IN THE LOW 100S AHEAD OF
A COLD FRONT CURRENTLY MOVING THROUGH SWRN SD. NOTE THAT NO
SIGNIFICANT ADJUSTMENTS WERE MADE TO FCST HIGHS ACROSS THE
NORTHWEST ZONES WHERE A FRONT SHOULD MOVE THROUGH THIS MORNING. A
SLIGHT UPWARD ADJUSTMENT WAS MADE TO TEMPERATURES ACROSS AREAS
AHEAD OF THE FRONT IN NCNTL NEB.
&&
.PREV DISCUSSION... /ISSUED 640 AM CDT WED JUL 4 2012/
AVIATION...
UNRESTRICTED FLIGHT CONDITIONS ARE EXPECTED OVER WESTERN
NEBRASKA THROUGH THIS AFTERNOON. ISOLATED THUNDERSTORMS...WITH
THE USUAL RISK OF LIGHTNING AND STRONG DOWNBURST WIND...ARE EXPECTED
OVER THE SANDHILLS AND PARTS OF SOUTHWEST NEBRASKA LATE THIS
AFTERNOON AND THIS EVENING. STORMS THAT DEVELOP WILL MOST LIKELY
FORM SOUTH OF A VTN-MHN-AIA LINE. THE PROBABILITY IS 35 PERCENT OR
LOWER IN THE AREA...SO WE HAVE NOT INCLUDED THUNDER IN THE TERMINAL
FORECASTS FOR LBF AND VTN.
PREV DISCUSSION... /ISSUED 307 AM CDT WED JUL 4 2012/
DISCUSSION...THE CONTINUED HEAT...FIRE WEATHER...AND TSTM
CHANCES ARE THE MAIN CONCERNS THE NEXT SEVERAL DAYS.
FOR TODAY...A COLD FRONT WILL BE DRIVEN SOUTH INTO NEBRASKA AS A
STRONG AREA OF LOW PRESSURE TRACKS ACROSS CENTRAL CANADA. SREF/NAM
AGREE THAT THIS FRONT WILL STALL OUT BY AFTERNOON FROM NEAR OR JUST
WEST OF ONEILL...TO AROUND NORTH PLATTE AND IMPERIAL. SOUNDINGS
TO INDICATE THAT THE CAP/CIN SHOULD ERODE DURING THE AFTERNOON
ALONG AND JUST AHEAD OF THE BOUNDARY. EXPECTING AT LEAST A FEW
TSTMS WILL FIRE NEAR THE FRONT. AGAIN TODAY HOWEVER...THESE STORMS
WILL BE HIGH BASED AS LCL/S WILL BE AROUND 10000 FT AGL. SREF IS
HINTING AT SOME POOLING OF MOISTURE/DEW POINTS INVOF OF THE FRONT
HOWEVER...SO IF STORMS COULD TAP INTO THAT MOISTURE BASES COULD BE
LOWER. FOR NOW THOUGH...EXPECTING MOSTLY HIGH BASED STORMS. AS HAS
BEEN THE CASE THE LAST FEW DAYS...THESE TYPES OF STORMS HAVE BEEN
RESPONSIBLE FOR GUSTY WINDS AND DANGEROUS CLOUD TO GROUND
LIGHTNING...BUT NOT A LOT IN THE WAY OF RAINFALL. WILL HAVE TO
WATCH FOR POTENTIAL GRASS FIRES IN AREAS WHERE LITTLE RAIN OCCURS
WITH THE STORMS. AS FAR AS SEVERE POTENTIAL...NOT EXPECTING MUCH.
RATHER WEAK SHEAR NOTED...BUT DO HAVE SOME RESPECTABLE MID LEVEL
LAPSE RATES. AS STATED EARLIER...MAY SEE SOME GUSTY WINDS THAT
COULD REACH NEAR SEVERE CRITERIA...BUT THE HAIL THREAT IS LOW.
OTHERWISE WILL CONTINUE THE HEAT ADVISORY FOR TODAY. EVEN THOUGH
TEMPS COULD BE A COUPLE OF DEGREES COOLER WITH THE FRONT PUSHING
SOUTH...INCREASING DEW POINTS WILL PUSH HEAT INDEXES UP INTO THE
100 DEGREE RANGE.
CHANCE FOR A FEW TSTMS AGAIN THURSDAY...WITH MUCH THE SAME SCENARIO
AS TODAY...WITH WEAKLY SHEARED HIGH BASED MULTICELL TSTMS POSSIBLE
DURING THE AFTERNOON INVOF STALLED FRONT ACROSS NORTHERN NEBRASKA.
CONTINUED HOT WEATHER...ESPECIALLY ALONG AND SOUTH OF THE
AFOREMENTIONED FRONTAL BOUNDARY.
FRONT SURGES BACK NORTH INTO SOUTHERN SD FRIDAY...WITH HIGHS MOST
AREAS AT OR NEAR 100 DEGREES. RATHER BREEZY SOUTH WINDS EXPECTED AS
WELL.
PATTERN SHIFT LOOKS TO BEGIN SATURDAY...AS THE LARGE UPPER LEVEL
RIDGE OF HIGH PRESSURE MIGRATES WEST FROM THE CENTRAL PLAINS INTO
THE ROCKIES. THIS SHOULD ALLOW FOR COOLING TEMPERATURES
ALOFT...ALLOWING FOR MORE ORGANIZED TSTM ACTIVITY ALONG A FRONTAL
BOUNDARY MOVING SLOWLY SOUTH THROUGH THE PLAINS SUNDAY THROUGH
TUESDAY. OTHER BIG STORY WILL BE HIGHS COOLING INTO THE 80S BY THE
FIRST OF NEXT WEEK.
FIRE WEATHER...HOT WEATHER WILL CONTINUE OVER WESTERN AND NORTH
CENTRAL NEBRASKA INTO THIS WEEKEND. ALTHOUGH RELATIVE HUMIDITY AND
WIND ARE NOT EXPECTED TO CROSS THE CRITICAL FIRE
THRESHOLDS...VEGETATION WILL CONTINUE LOSING MOISTURE EACH DAY.
LIGHTNING IS STILL POSSIBLE WITH ISOLATED THUNDERSTORMS AND IS
EXPECTED TO BE A PROBLEM IN THE SANDHILLS AND THE SOUTHWEST. WITH
THAT...ADDED TO EXTENSIVE USE OF FIREWORKS...FIRE HAS BEEN AND
WILL CONTINUE TO BE A THREAT THROUGH THE DAY TODAY. EVEN AFTER
TODAY...ISOLATED THUNDERSTORMS AND THE ASSOCIATED LIGHNING AND
ERRATIC WIND WILL CONTINUE TO PRESENT A FIRE MANAGEMENT PROBLEM.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...HEAT ADVISORY UNTIL 9 PM CDT
THURSDAY FOR NEZ005>010-025>029-037-038-059-070-071.
&&
$$
SHORT TERM/EXTENDED...CDC
AVIATION...MASEK
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1042 PM EDT THU JUL 5 2012
.SYNOPSIS...
BERMUDA HIGH PRESSURE OFFSHORE AND THE PIEDMONT TROUGH INLAND WILL
PREVAIL THROUGH MUCH OF THE FORECAST PERIOD...BRINGING HOT AND HUMID
CONDITIONS WITH ISOLATED THUNDERSTORMS EACH AFTERNOON AND EVENING.
AN UPPER RIDGE OVER THE AREA WILL SLOWLY WEAKEN NEXT WEEK...BRINGING
DAYTIME TEMPERATURES CLOSER TO NORMAL FOR JULY. AN APPROACHING
COLD FRONT WILL STALL NEAR THE AREA BEGINNING TUESDAY...BRINGING
INCREASED RAIN CHANCES THROUGH MUCH OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 1030 PM THURSDAY...WATER VAPOR IMAGERY COMBINED WITH SURFACE
ANALYSIS PAINTS THE PICTURE TONIGHT...WITH SURFACE HIGH PRESSURE
SINKING SOUTH ACROSS EASTERN TENNESSEE AND A LARGE UPPER RIDGE
HOLDING FIRM ACROSS THE MIDWEST. AT THE SAME TIME...SOUTHWEST
MONSOON MOISTURE IS WRAPPING UP ALONG THE WESTERN EDGE OF THE RIDGE
IN NM/CO...AND ROTATING BACK DOWN THE EASTERN PERIPHERY IN THE
APPALACHIANS...HELPING TO FUEL OUR STORMS TONIGHT.
ADDITIONALLY...S/SW RETURN FLOW AROUND OFFSHORE BERMUDA HIGH HAS
HELPED DRIVE DEWPOINTS WELL INTO THE 70S MOST LOCATIONS.
AS EXPECTED...CONVECTION FROM EARLIER HAS SLOWLY BEGUN TO WANE
THANKS TO LOSS OF HEATING. HOWEVER...THE ELEVATED INSTABILITY AND
STRONGLY-NEGATIVE LI`S AS SHOWN ON BOTH NAM AND RUC FORECAST
PROFILES CONTINUE TO BE TAPPED BY RESIDUAL OUTFLOWS/BOUNDARIES...IN
CONJUNCTION WITH UPPER IMPULSE NOW ROTATING OFF TO THE SOUTHWEST.
LATEST SPC RUC ANALYSIS SHOWS CONVECTION IS NOW CAPPED TO BOTH
SURFACE BASED...AND MIXED LEVEL PARCELS...WITH LPL HEIGHTS OF
500-1000M NOW REQUIRED TO GAIN INSTABILITY. STILL...CONVECTION WILL
PERSIST...IN A LIMITED/ISOLATED FORM...FOR A FEW MORE HOURS BEFORE
DISSIPATING ENTIRELY AFTER MIDNIGHT. THIS CONVECTION SHOULD REMAIN
RATHER SHALLOW HOWEVER...EVIDENCED BY DRY AIR ABOVE 600MB IN
FORECAST SOUNDINGS...SO EVEN LIGHTNING WILL BE DIFFICULT TO COME BY
THE REST OF THE NIGHT. HRRR FINALLY COMING INTO AGREEMENT WITH THE
FAVORED ARW...WHICH AGREES WITH ONGOING FORECAST OF POP DECREASING
TO SILENT BY 2AM.
AS SURFACE HIGH DRIFTS SOUTH NEAR TENNESSEE...A DECENT LLJ OF 25-30
KTS WILL DEVELOP ABOVE THE NOCTURNAL INVERSION. THIS WILL WORK IN
TANDEM WITH SOME MID/HIGH LEVEL CLOUD COVER TO KEEP TEMPS FROM
FALLING TOO MUCH TONIGHT. HAVE LEANED MORE TOWARDS THE WARMER NAM
GUIDANCE...WITH LOWS IN THE MID 70S INLAND...TO NEAR 80 AT THE
IMMEDIATE COAST.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...MID/UPPER LEVEL RIDGE OVER THE CENTRAL
CONUS ON FRIDAY WILL FLATTEN AND SPREAD EASTWARD ON SATURDAY...
WITH INCREASING HEIGHTS OVER THE CWA THROUGH THE PERIOD. TIME-
HEIGHT CROSS SECTIONS SHOW A LAYER OF RELATIVELY DRY AIR BETWEEN
700-400 MB...WITH ONLY MODEST MOISTURE BELOW 700 MB. A DEEP LAYER
OF SUBSIDENCE IS ALSO NOTED IN RESPONSE TO THE INCREASING HEIGHTS.
ALTHOUGH DEEP MOISTURE IS LACKING...SURFACE DEWPOINTS IN THE MID
70S COMBINED WITH SB CAPE TO 2500 J/KG AND LI`S TO -6C WILL MAKE IT
TOUGH TO RULE OUT THE CHANCE FOR CONVECTION ALTOGETHER. ISOLATED
DEVELOPMENT WILL BE POSSIBLE FRIDAY AND SATURDAY ALONG THE SEA
BREEZE AND PIEDMONT TROUGH...BUT EXPECT CHANCES TO BE HIGHER
FRIDAY AS A SUBTLE MID-LEVEL SHORTWAVE DROPS SOUTH ACROSS THE
AREA DURING MIDDAY HEATING. ALSO NOTABLE LATE FRIDAY NIGHT AND
THROUGH SATURDAY IS DEEP ONSHORE FLOW ABOVE 700 MB. ANY CONVECTION
THAT DEVELOPS OVER THE WATERS WILL BE STEERED TOWARDS SHORE.
GIVEN WIDESPREAD HIGHS EXPECTED TO BE IN THE MID AND UPPER
90S FRIDAY AND SATURDAY...AND DEWPOINTS IN THE MID 70S...HEAT INDICES
SHOULD REACH 105 AT MANY LOCATIONS. THEREFORE WILL RAISE ANOTHER
HEAT ADVISORY FOR FRIDAY...AND ONE MAY BE REQUIRED FOR SATURDAY ALSO.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...SUNDAY SHOULD BE THE LAST DAY OF EXTREME
HEAT. HIGH TEMPERATURES IN THE UPPER 90S AWAY FROM THE COAST COUPLED
WITH MID-70S DEWPOINTS SHOULD AGAIN YIELD HEAT INDICES ABOVE 105
DEGREES DURING THE DAY. THE HOT UPPER LEVEL RIDGE CAUSING THE HEAT
THIS WEEKEND WILL PASS VIRTUALLY OVERHEAD SUNDAY...THEN OFFSHORE
MONDAY. THIS WILL SHIFT THE DEEP-LAYER FLOW AROUND TO THE SOUTH ON
MONDAY... WITH DECREASING 850 MB TEMPS AND 1000-500 MB THICKNESSES
SHOWN ON GFS/ECMWF MODEL PLOTS. MONDAY`S HIGHS SHOULD THEREFORE RUN
A FEW DEGREES COOLER THAN ON SUNDAY. COOLING AND MOISTENING
MID-LEVELS SHOULD FAVOR BETTER A LITTLE CONVECTIVE POTENTIAL MONDAY
AS WELL.
BY TUESDAY THE PATTERN BECOMES EVEN MORE FAVORABLE FOR CONVECTION AS
A SYNOPTIC SURFACE FRONT DROPS SOUTH INTO THE CAROLINAS AND DEEP
MOISTURE INCREASES ALOFT AHEAD OF A DEVELOPING LONGWAVE TROUGH
EXTENDING FROM THE GREAT LAKES DOWN TO THE GULF COAST. GFS AND ECMWF
FORECAST SOUNDINGS SHOW AN UNCAPPED TROPICAL AIRMASS WITH SLIGHTLY
STEEPER THAN MOIST-ADIABATIC LAPSE RATES PERSISTING FOR SEVERAL DAYS
THIS WEEK...WITH PRECIP WATER INCREASING TO NEAR 2.0 INCHES. WE`VE
INCREASED THE AREA OF 40-50 PERCENT 12-HR POPS FORECAST TUESDAY
THROUGH THURSDAY AS THIS PATTERN CERTAINLY SHOULD EXCEED THE
CLIMATOLOGICAL 20-30 PERCENT 12-HR POP FOR THIS TIME OF YEAR.
UNIDIRECTIONAL SOUTH-SOUTHWEST WINDS AND MODEST LAPSE RATES WILL
SUPPORT HEAVY RAINFALL BUT NOT NECESSARILY SEVERE WEATHER.
DIURNAL TEMPERATURE RANGES WILL BECOME CONSTRICTED TUESDAY THROUGH
THURSDAY BY THE ADDITIONAL CLOUDS AND PRECIP...WITH HIGHS AVERAGING
IN THE UPPER 80S. LOWS SHOULD RANGE FROM 70-75.
&&
.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
AS OF 00Z...EXPECT VFR THROUGH THE VALID PERIOD WITH EXCEPTION OF
POSSIBLE BRIEF MVFR DUE TO PATCHY FOG EARLY FRIDAY MORNING AND IN
ANY CONVECTION THROUGH THE EARLY OVERNIGHT HOURS AND AGAIN DURING
FRIDAY AFTERNOON.
AFTER A FEW ISOLATED PULSE THUNDERSTORMS LATE THIS
AFTERNOON...CURRENT RADAR IMAGERY CONTINUES TO LIGHT UP WITH PULSE
CONVECTION ACROSS THE CAROLINAS. SOME OF THESE THUNDERSTORMS ARE
JUST ON THE FRINGE OF OUR CWA AND ANTICIPATE THIS CONVECTION TO
MOVE INTO THE INLAND SITES WITHIN THE NEXT HOUR. GIVEN CONTINUED
FAVORABLE STATE OF ATMOSPHERE...HAVE KEPT IN VCTS/VCSH AT ALL
SITES THROUGH THE EARLY OVERNIGHT HOURS. ANTICIPATE ANY CONVECTION
TO GRADUALLY TAPER OFF LATE OVERNIGHT LEAVING FEW MID TO HIGH-
LEVEL CLOUD DEBRIS TO LINGER ACROSS THE AREA WITH SOUTH- SOUTHWEST
WINDS AOB 10 KTS. THOUGH CONDITIONS WILL BE IDEAL FOR RADIATIONAL
COOLING...EXPECT INCREASED WINDS TO INHIBIT ANY FOG FORMATION
GIVEN INCREASED LOW LEVEL JET. HOWEVER...CANNOT COMPLETELY RULE
OUT BRIEF PATCHY MVFR FOG EARLY FRIDAY MORNING...ESPECIALLY AT
INLAND SITES.
AFTER DAYBREAK...SOUTHWEST WINDS WILL CONTINUE AND INCREASE
THROUGHOUT THE DAY TO AOB 10 KTS WITH GUSTS NEAR 15 KTS POSSIBLE
ALONG THE COAST. CANNOT RULE OUT ISOLATED TO SCATTERED CONVECTION
DURING THE AFTERNOON AND EVENING HOURS...THUS HAVE INTRODUCED VCTS.
EXTENDED OUTLOOK...A CHANCE OF THUNDERSTORMS EACH DAY...MAINLY IN
THE AFTERNOON AND EVENING. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM THURSDAY...SW FLOW AROUND BERMUDA HIGH OF 10-20 KTS
PERSISTING ACROSS THE COASTAL WATERS...WITH BUOYS REPORTING SEAS OF
3-4 FT. GUIDANCE STILL SHOWING THE DEVELOPMENT OF A STRONG LOW LEVEL
JET TONIGHT AS HIGH PRESSURE SINKS SOUTH ACROSS TENNESSEE. THIS
COULD ENHANCE WINDS ACROSS THE WATERS. HOWEVER...TEMPS 1200-1500 FT
ABOVE THE SURFACE SHOULD BE WARM ENOUGH THAT A WEAK INVERSION WILL
DEVELOP EVEN ACROSS THE WATERS (WATER TEMPS IN THE UPPER 70S ATTM)
SO FULL DOWNWARD MIXING IS NOT ANTICIPATED...AND WINDS/SEAS SHOULD
REMAIN BELOW ANY CAUTIONARY HEADLINE CRITERIA. FOR THIS REASON
EXPECT STATUS QUO...3-4 FT SEAS AND 10-20 KTS SW WINDS CONTINUING
THROUGH DAYBREAK...ALTHOUGH AN ISOLATED 5 FTER IS NOT OUT OF THE
QUESTION NEAR THE 20NM BOUNDARY.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...SOUTHWEST FLOW WILL PERSIST OVER THE WATERS
THROUGH THE PERIOD BETWEEN A SURFACE TROUGH LOCATED OVER THE
INLAND CAROLINAS AND BERMUDA HIGH PRESSURE. THE MSLP GRADIENT
MAGNITUDE WILL INCREASE EACH AFTERNOON IN RESPONSE TO THE SEA
BREEZE.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 PM THURSDAY...HIGH PRESSURE WELL OFF THE U.S. EAST COAST
SHOULD CONTINUE TO PUMP A WARM AND HUMID AIRMASS ONSHORE THROUGH
EARLY NEXT WEEK. THE PIEDMONT TROUGH SUNDAY WILL BECOME REPLACED ON
MONDAY BY LOW PRESSURE ALONG A COLD FRONT DIPPING SOUTH FROM
VIRGINIA. THIS FRONT SHOULD REMAIN NORTH OF THE COASTAL WATERS...BUT
MAY GET CLOSE ENOUGH TO BRING INCREASING CHANCES OF SHOWERS AND
THUNDERSTORMS MONDAY INTO TUESDAY. OTHERWISE...SOUTHWEST WINDS 10-15
KNOTS MAY INCREASE TO NEAR 20 KNOTS NEARSHORE DURING THE AFTERNOONS
DUE TO THE SEA BREEZE CIRCULATION. SEAS SHOULD AVERAGE 2-4 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...HEAT ADVISORY FROM NOON TO 8 PM EDT FRIDAY FOR SCZ017-023-024-
032-033-039-053>056.
NC...HEAT ADVISORY FROM NOON TO 8 PM EDT FRIDAY FOR NCZ087-096-099-
105>110.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW/CRM
NEAR TERM...JDW
SHORT TERM...CRM
LONG TERM...TRA
AVIATION...SGL
MARINE...JDW/SHK/CRM
AREA FORECAST DISCUSSION
NWS RALEIGH NC
921 PM EDT THU JUL 5 2012
.SYNOPSIS...
AN UPPER LEVEL RIDGE EXTENDING EASTWARD FROM THE CENTRAL MISSISSIPPI
RIVER VALLEY TOWARD THE CAROLINAS WILL RESULT IN ABOVE NORMAL
TEMPERATURES THROUGH THE UPCOMING WEEKEND...WITH A CHANCE FOR
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON
AND EVENING HOURS EACH DAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1130 AM THURSDAY...
OVERVIEW:
NORTHWEST FLOW ALOFT WILL PREVAIL OVER THE CAROLINAS THROUGH
TONIGHT...ON THE EASTERN PERIPHERY OF AN UPPER LEVEL RIDGE CENTERED
OVER THE CENTRAL MS RIVER VALLEY. 14Z WV IMAGERY AND RUC DATA
INDICATED MULTIPLE MID/UPPER LEVEL DISTURBANCES EMBEDDED WITHIN NW
FLOW ALOFT OVER THE MID-ATLANTIC AND CAROLINAS.
TEMPERATURES:
THE 12Z GSO RAOB INDICATED A 1000-850 MB THICKNESS OF 1434 METERS
THIS MORNING. THIS IS CONSISTENT WITH THE LATEST MODEL GUIDANCE...
WHICH CONTINUES TO INDICATE 1000-850 MB THICKNESSES IN VICINITY OF
1455 METERS BY 00Z...ROUGHLY 10-15 METERS HIGHER THAN YESTERDAY.
MODEL GUIDANCE INDICATES H85 TEMPS IN THE 21-23C RANGE THIS
AFTERNOON...GENERALLY CONSISTENT WITH UPSTREAM CONDITIONS PER 14Z
SPC MESOANALYSIS (THOUGH COOLER TEMPS ARE PRESENT OVER WV IN ASSOC/W
MCS REMNANTS). HIGHS YESTERDAY RANGED FROM 95-98F IN MOST
LOCATIONS...RDU AN EXCEPTION AT 101F. BASED ON YESTERDAY`S TEMPS AND
A 10-15 METER INCREASE IN THICKNESSES...EXPECT HIGHS IN VICINITY OF
100F TODAY...THOUGH ISOLD/SCT CONVECTION MAY PREVENT HIGHS FROM
EXCEEDING THE MID/UPPER 90S IN SOME LOCATIONS. DECIDED TO INCREASE
THE HIGH AT RDU TO 102F BASED ON YESTERDAY`S READING. WILL DECREASE
HIGHS A FEW DEGREES LOWER THAN WHAT THICKNESSES SUGGEST IN THE FAR
NW PIEDMONT WHERE OUTFLOW FROM MCS REMNANTS (AND NEWLY DEVELOPED
CONVECTION NEAR BLUEFIELD WV) MAY AFFECT TEMPS BY EARLY/MID
AFTERNOON. H85 DEWPOINTS RANGED FROM 13-15C (55-60F) ACROSS THE AREA
AT 14Z...AND SHOULD REMAIN IN THAT VICINITY THROUGH THE AFTERNOON.
GIVEN STRONG HEATING AND MIXING UP TO AT LEAST H85...ANTICIPATE THAT
DEWPOINTS WILL MIX OUT INTO THE LOWER/MID 60S IN THE NORTHERN AND
WESTERN PIEDMONT. IN THE SANDHILLS AND COASTAL PLAIN ON THE EASTERN
PERIPHERY OF THE LEE TROUGH...EXPECT DEWPOINTS WILL LIKELY REMAIN IN
THE UPPER 60S TO LOWER 70S GIVEN RELATIVELY HIGHER H85 DEWPOINTS IN
THE PRESENCE OF SHALLOW LOW-LEVEL CONVERGENCE AND MOISTURE POOLING.
EXPECT OVERNIGHT LOWS A BIT WARMER THAN THIS MORNING DUE TO AIRMASS
MODIFICATION...IN THE LOWER/MID 70S...OR 72-75F.
HEAT INDICES/HEAT ADVISORY:
WITH THE ABOVE T/TD DISCUSSION IN MIND...ANTICIPATE MAX HEAT INDICES
BETWEEN 105-110F IN THE ADVISORY AREA...WITH HEAT INDICES
APPROACHING 105F IN THE TRIANGLE...AND GENERALLY 100-105F IN THE
WESTERN PIEDMONT. DESPITE MAX HEAT INDICES FORECAST NEAR 105F IN
WAKE/FRANKLIN/WARREN COUNTIES...DECIDED NOT TO EXPAND THE HEAT
ADVISORY TO INCLUDE THOSE COUNTIES GIVEN A FAIR AMOUNT OF
UNCERTAINTY W/REGARD TO DEWPOINTS ALONG/WEST OF HWY 1 AND CONVECTIVE
EVOLUTION MID/LATE AFTERNOON.
PRECIPITATION CHANCES:
MID-LEVEL LAPSE RATES ARE SEASONABLY STEEP TODAY ACCORDING TO 15Z
SPC MESOANALYSIS DATA...IN VICINITY OF 6.5 C/KM. GIVEN SURFACE TEMPS
EASILY IN THE MID/UPPER 90S AND DEWPOINTS RANGING FROM THE LOWER/MID
60S TO NEAR 70F (IN ANTICIPATION OF SOME MIX-DOWN BY 18-21Z)...
EXPECT MLCAPE VALUES SOLIDLY IN THE MODERATE RANGE...PERHAPS
STRONG...GENERALLY BETWEEN 1500-2500 J/KG. W/REGARD TO FORCING... A
COMPLEX NW FLOW ALOFT PATTERN IS PRESENT OVER CENTRAL NC...WITH AT
LEAST SEVERAL IMPORTANT FEATURES. 1) A SHORTWAVE IN VICINITY OF CAPE
FEAR IS PROGGED TO TRACK SOUTHWARD INTO EASTERN SC/OFFSHORE AS THE
AFTERNOON PROGRESSES...AND SUBSIDENCE IN THE WAKE OF THIS FEATURE
MAY INITIALLY SUPPRESS DEVELOPMENT OVER THE COASTAL PLAIN...
ESPECIALLY IN THE SE COASTAL PLAIN. 2) THE REMNANTS OF AN MCS OVER
NORTHERN VA AT 03Z HAVE PROGRESSED INTO CENTRAL NC EARLY THIS
AFTERNOON. HOWEVER...FORCING ASSOC/W THIS FEATURE IS DIFFICULT TO
ASCERTAIN. 3) THE REMNANTS OF AN MCS OVER OHIO AT 03Z HAVE
PROGRESSED INTO SOUTHWEST VA BY 17Z THIS AFTERNOON...ALREADY FORCING
CONVECTION ALONG THE I-77 CORRIDOR IN NORTHWEST NC. 4) AN ONGOING
MCS IN WV AT 17Z...THOUGH EXPECTED TO TRACK INTO THE FAR WESTERN
PORTIONS OF THE STATE. ADDITIONALLY...A SURFACE TROUGH AXIS IN
VICINITY OF THE HWY 1 CORRIDOR WILL PROVIDE A LOW-LEVEL FOCUS FOR
CONVECTION THIS AFT/EVE. WITH THE ABOVE IN MIND...WILL INDICATE
PRECIP CHANCES 30-40% IN THE FAR WESTERN PIEDMONT...AND 20-30% IN
VICINITY OF THE HWY 1 CORRIDOR...AND ~20% IN THE CENTRAL/SE COASTAL
PLAIN.
SEVERE THREAT:
MLCAPE SOLIDLY IN THE MODERATE RANGE WILL RESULT IN ROBUST UPDRAFTS
TODAY...THOUGH DEEP-LAYER SHEAR WILL BE NO MORE THAN 15-20 KT.
HOWEVER...DUE TO LARGE T/TD SPREADS AND VERY HIGH DCAPE VALUES
ANALYZED PER LATEST SPC MESOANALYSIS (1000-1600 J/KG...HIGHEST
WEST)...EXPECT MULTICELL ORGANIZATION PRIMARILY ALONG OUTFLOW.
THOUGH HAIL UP TO THE SIZE OF QUARTERS WILL BE POSSIBLE GIVEN
MODERATE INSTABILITY...THE PRIMARY THREAT WILL BE ASSOCIATED WITH
DAMAGING WINDS OWING TO VERY HIGH DCAPE VALUES/STRONG BOUNDARY LAYER
EVAPORATIVE COOLING POTENTIAL. THE THREAT FOR SEVERE WEATHER WILL BE
HIGHEST IN THE WESTERN PIEDMONT (WHERE THE SLIGHT RISK IS INDICATED
ON THE DAY 1 OUTLOOK) BETWEEN 1 PM THIS AFTERNOON AND 8-11 PM THIS
EVENING. THIS IS WHERE THE HIGHEST DCAPE VALUES ARE PRESENT AND
WHERE THE RELATIVE BEST MID LEVEL FORCING IS EXPECTED AS REMNANT MCS
ACTIVITY PROGRESSES SOUTH/SSW INTO WESTERN PORTIONS OF THE STATE.
ISOLATED SEVERE WEATHER WILL BE POSSIBLE ELSEWHERE CONVECTION IS
PRESENT OWING TO 1000+ J/KG OF DCAPE/STEEP LOW-LEVEL LAPSE RATES IN
THE PRESENCE OF MODERATE INSTABILITY. -VINCENT
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 220 PM THURSDAY...
THE MID LEVEL RIDGE CURRENTLY CENTERED TO OUR WEST OVER THE CENTRAL
PLAINS WILL EXPAND EASTWARD AS THE TROUGH OFF THE NEW ENGLAND COAST
MOVES EAST. AT THE SFC AND LOWER LEVELS...NOT MUCH WILL CHANGE WITH
THE LEE TROUGH REMAINING IN PLACE. LOW LEVEL THICKNESSES ARE PROGGED
TO REMAIN THE SAME...THUS EXPECT HIGHS TOMORROW VERY SIMILAR TO
TODAYS VALUES...AROUND 100 ACROSS MUCH OF OUR CWA. GUIDANCE IS IN
GOOD AGREEMENT THAT DWPTS WILL BE LOWER ACROSS OUR WESTERN ZONES
(UPPER 60S WEST TO LOWER 70S EAST)...THUS HEAT INDEX VALUES WILL
RANGE FROM 100-103 WEST TO 104-107 EAST. THE HEAT ADVISORY THAT IS
ALREADY IN EFFECT FROM 11 AM TO 8 PM FRIDAY LOOKS GOOD AND WILL
LEAVE AS-IS. AS FOR TSTM POTENTIAL ON FRIDAY...NOTED SUBTLE
MID-LEVEL WARMING IN FORECAST SOUNDINGS BUT STILL ENOUGH MOISTURE
AND INSTABILITY/CAPE TO SEE SOME AFTERNOON TSTMS. GFS DEPICTS A WEAK
MID LEVEL SHEAR AXIS MOVING SOUTHEAST ACROSS THE STATE LATE IN THE
DAY. THUS EXPECT ISOLATED TO SCATTERED TSTMS...WITH PERHAPS THE
BETTER CHANCE FOR TSTMS ACTIVITY AND STRONGER INTENSITY WILL BE
ACROSS OUR EASTERN PIEDMONT AND COASTAL PLAIN ZONES WHERE FORECAST
SOUNDINGS AND SFC DWPT PROGS SUGGEST BETTER CAPE. ANY ACTIVITY WILL
WIND DOWN DURING THE LATE EVENING WITH PC CONDITIONS AT NIGHT. LOWS
FRI NIGHT IN THE LOW-MID 70S.
ON SATURDAY THE MID LEVEL RIDGE WILL BUILD OVER TOP OF CENTRAL NC...
WITH CONTINUED MID LEVEL WARMING. WITH 850 MB TEMPS WARMING AND LOW
LEVEL THICKNESSES INCREASING...EXPECT ANOTHER HOT DAY WITH HIGHS
ONCE AGAIN AROUND 100. HEAT ADVISORIES MAY ONCE AGAIN BE NEEDED.
WITH THE AFOREMENTIONED MID LEVEL WARMING AND WEAKENING LAPSE
RATES...TSTM COVERAGE SHOULD BE FURTHER REDUCED. BEST CHANCE WILL
CONTINUE TO BE ACROSS OUR EASTERN ZONES WHERE HIGHER PW AND DWPTS
ARE LOCATED. LITTLE CHANGE SATURDAY NIGHT...LOWS IN THE MID 70S.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 220 PM THURSDAY...
ON SUNDAY THE MID LEVEL RIDGE WILL MOVE EAST AS A POTENT SHORT WAVE
MOVES SE ACROSS THE GREAT LAKES. A COLD FRONT WILL BE MOVING ACROSS
THE OH RIVER VALLEY. SUNDAY SHOULD BE THE LAST HOT DAY IN THE
FORECAST PERIOD WITH LITTLE OR NO AIRMASS CHANGE FROM PREVIOUS DAYS.
EXPECT HIGHS ONCE AGAIN AROUND 100. WITH MID LEVELS BEGINNING TO
COOL AND PWAT INCREASING AHEAD OF THE TROUGH...WILL CONTINUE WITH
ISOLD TO SCATTERED AFTERNOON AND EVENING TSTMS.
MONDAY WILL BE A TRANSITION DAY AS THE LONGWAVE TROUGH DEEPENS
ACROSS THE EASTERN HALF OF THE COUNTRY AND THE ASSOC COLD FRONT
STALLS ACROSS THE CAROLINAS. THIS PATTERN WILL THEN REMAIN WITH US
THROUGH MUCH OF THE WEEK...RESULTING IN AT LEAST A GOOD CHANCE FOR
SHOWERS AND TSTMS EACH DAY AND NEAR SEASONABLE TEMPS.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 730 PM THURSDAY...
THE CONVECTION THAT DEVELOPED THIS AFTERNOON HAS DECREASED IN
COVERAGE...WITH ONLY SOME ACTIVITY REMAINING ACROSS THE SOUTHERN
PORTIONS OF THE FORECAST AREA...POSSIBLY IMPACTING KFAY OVER THE
NEXT HOUR OR SO. THIS ACTIVITY WILL DECREASE IN INTENSITY AS IT
CONTINUES TO MOVE SOUTH AND OUT OF THE FORECAST AREA DURING THE NEXT
COUPLE OF HOURS. AM EXPECTING MOSTLY VFR CONDITIONS FOR THE NEXT 24
HOURS...WITH A FEW EXCEPTIONS. FIRST...AS HAS BEEN THE CASE THE PAST
SEVERAL NIGHT...THERE IS THE POTENTIAL FOR SOME BRIEF PATCHY MVFR
FOG...MOST LIKELY AFFECTING KRWI...JUST BEFORE SUNRISE ON FRIDAY.
SECOND...ANOTHER ROUND OF CONVECTION ON FRIDAY AFTERNOON/EVENING MAY
BRING BRIEF PERIODS OF MVFR CONDITIONS TO THE AREA...BUT HAVE NOT
MENTIONED THUNDER IN THE TAFS AT THIS TIME AS CONFIDENCE IN TIMING
AND LOCATION IS LOW.
OUTLOOK....MAINLY VFR CONDITIONS ARE EXPECTED FOR THE REMAINDER OF
THE PERIOD AS AN AREA OF HIGH PRESSURE ALOFT EXTENDS ACROSS THE
CAROLINAS. THIS WEATHER SYSTEM WILL INHIBIT THE DEVELOPMENT OF
WIDESPREAD CONVECTION...ALTHOUGH ISOLATED DIURNAL STORMS CANNOT BE
RULED OUT THROUGH THE PERIOD. PRECIP CHANCES AND RESULTANT ADVERSE
AVIATION CONDITIONS MAY INCREASE BY THE BEGINNING OF NEXT WEEK AS A
FRONT APPROACHES THE REGION.
&&
.CLIMATE...
HIGH TEMPERATURE RECORDS AND YEAR RECORD LAST SET.
RALEIGH-DURHAM... GREENSBORO...
07/05 102 1999 98 1990
07/06 102 1999 100 1977
07/07 102 2010 101 1977
07/08 103 1977 102 1977
FAYETTEVILLE...
07/05 101 2002
07/06 99 1990
07/07 103 2010
07/08 102 1977
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM 11 AM TO 8 PM EDT FRIDAY FOR NCZ008>011-
025>028-040>043-074>078-083>086-088-089.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...NP
LONG TERM...NP
AVIATION...KRR
CLIMATE...
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
825 PM EDT THU JUL 5 2012
.SYNOPSIS...
BERMUDA HIGH PRESSURE OFFSHORE AND THE PIEDMONT TROUGH INLAND WILL
PREVAIL THROUGH MUCH OF THE FORECAST PERIOD...BRINGING HOT AND HUMID
CONDITIONS WITH ISOLATED THUNDERSTORMS EACH AFTERNOON AND EVENING.
AN UPPER RIDGE OVER THE AREA WILL SLOWLY WEAKEN NEXT WEEK...BRINGING
DAYTIME TEMPERATURES CLOSER TO NORMAL FOR JULY. AN APPROACHING
COLD FRONT WILL STALL NEAR THE AREA BEGINNING TUESDAY...BRINGING
INCREASED RAIN CHANCES THROUGH MUCH OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 730 PM THURSDAY...WATER VAPOR IMAGERY COMBINED WITH SURFACE
ANALYSIS PAINTS THE PICTURE THIS EVENING...WITH SURFACE HIGH
PRESSURE SINKING SOUTH ACROSS EASTERN TENNESSEE AND A LARGE UPPER
RIDGE HOLDING FIRM ACROSS THE MIDWEST. AT THE SAME TIME...SOUTHWEST
MONSOON MOISTURE IS WRAPPING UP ALONG THE WESTERN EDGE OF THE RIDGE
IN NM/CO...AND ROTATING BACK DOWN THE EASTERN PERIPHERY IN THE
APPALACHIANS...HELPING TO FUEL OUR STORMS TONIGHT.
ADDITIONALLY...S/SW RETURN FLOW AROUND OFFSHORE BERMUDA HIGH HAS
HELPED DRIVE DEWPOINTS WELL INTO THE 70S MOST LOCATIONS.
THE AMPLE HEATING THAT OCCURRED TODAY (MANY SPOTS STILL HAVE HI`S
NEAR 105F AT THIS HOUR) HELPED PUSH SBCAPE ABOVE 3000 J/KG...AND
ALTHOUGH PARCELS ARE RAPIDLY BECOMING CAPPED TO SURFACE BASED
INSTABILITY DUE TO LOSS OF HEATING...RUC/NAM FORECAST SOUNDINGS
SUGGEST ELEVATED INSTABILITY ROOTED AROUND 900MB WILL PERSIST WELL
INTO THE NIGHT. MLCAPES OF 1500 J/KG ARE PROGGED TO REMAIN THROUGH
MIDNIGHT...WITH LI`S AROUND -7 AND DECENT COLUMN MOISTURE UP THROUGH
600MB. AT THE SAME TIME...WV IMAGERY SUGGESTS A RATHER POTENT
IMPULSE ROTATING DOWN THROUGH VA/NC ATTM WHICH WILL LIKELY AID IN
CONTINUING CONVECTION EVEN AFTER NIGHTFALL...IF NOT LOCALLY
ENHANCING IT. NOTE THAT THE HRRR HAS NOT BEEN SHOWING MUCH OF ANY
NOCTURNAL CONVECTION...BUT THE HIGH RES ARW...WHICH HAS DONE THE
BEST RECENTLY AND IS PERFORMING WELL TONIGHT...KEEPS SCATTERED
CONVECTION NEAR THE AREA THROUGH APPROX 1AM. UPSTREAM CONVECTION
ALONG A COMBINATION OF THE PIEDMONT TROUGH AND RESIDUAL OUTFLOWS IS
SLOWLY WORKING SOUTH (DUE TO WEAK STEERING FLOW) AND THIS WILL
BECOME THE PRIMARY SHOW. EXACTLY HOW STRONG CONVECTION WILL BE IS
STILL TO BE SEEN...BUT ISOLATED STRONG TO DAMAGING WIND GUSTS ARE
NOT OUT OF THE QUESTION FOR A FEW MORE HOURS. THE BEST CHANCE OF
TSTMS WILL BE ACROSS NORTHERN AND WESTERN ZONES.
THE HEAT ADVISORY WILL BE ALLOWED TO EXPIRE ON TIME AT 9PM...AND
MINS TONIGHT WILL REMAIN RATHER ELEVATED SINCE FULL DECOUPLING IS
NOT EXPECTED. AS SURFACE HIGH SINKS SOUTH...A STRONG LLJ OF 25-30
KTS AT 900MB SHOULD DEVELOP WHICH WILL COMBINE WITH MID LEVEL
MOISTURE TO KEEP MINS FROM FALLING OFF TOO QUICKLY. HAVE LEANED MORE
TOWARDS THE WARMER NAM GUIDANCE...WITH LOWS IN THE MID 70S
INLAND...TO NEAR 80 AT THE IMMEDIATE COAST.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...MID/UPPER LEVEL RIDGE OVER THE CENTRAL
CONUS ON FRIDAY WILL FLATTEN AND SPREAD EASTWARD ON SATURDAY...
WITH INCREASING HEIGHTS OVER THE CWA THROUGH THE PERIOD. TIME-
HEIGHT CROSS SECTIONS SHOW A LAYER OF RELATIVELY DRY AIR BETWEEN
700-400 MB...WITH ONLY MODEST MOISTURE BELOW 700 MB. A DEEP LAYER
OF SUBSIDENCE IS ALSO NOTED IN RESPONSE TO THE INCREASING HEIGHTS.
ALTHOUGH DEEP MOISTURE IS LACKING...SURFACE DEWPOINTS IN THE MID
70S COMBINED WITH SB CAPE TO 2500 J/KG AND LI`S TO -6C WILL MAKE IT
TOUGH TO RULE OUT THE CHANCE FOR CONVECTION ALTOGETHER. ISOLATED
DEVELOPMENT WILL BE POSSIBLE FRIDAY AND SATURDAY ALONG THE SEA
BREEZE AND PIEDMONT TROUGH...BUT EXPECT CHANCES TO BE HIGHER
FRIDAY AS A SUBTLE MID-LEVEL SHORTWAVE DROPS SOUTH ACROSS THE
AREA DURING MIDDAY HEATING. ALSO NOTABLE LATE FRIDAY NIGHT AND
THROUGH SATURDAY IS DEEP ONSHORE FLOW ABOVE 700 MB. ANY CONVECTION
THAT DEVELOPS OVER THE WATERS WILL BE STEERED TOWARDS SHORE.
GIVEN WIDESPREAD HIGHS EXPECTED TO BE IN THE MID AND UPPER
90S FRIDAY AND SATURDAY...AND DEWPOINTS IN THE MID 70S...HEAT INDICES
SHOULD REACH 105 AT MANY LOCATIONS. THEREFORE WILL RAISE ANOTHER
HEAT ADVISORY FOR FRIDAY...AND ONE MAY BE REQUIRED FOR SATURDAY ALSO.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...SUNDAY SHOULD BE THE LAST DAY OF EXTREME
HEAT. HIGH TEMPERATURES IN THE UPPER 90S AWAY FROM THE COAST COUPLED
WITH MID-70S DEWPOINTS SHOULD AGAIN YIELD HEAT INDICES ABOVE 105
DEGREES DURING THE DAY. THE HOT UPPER LEVEL RIDGE CAUSING THE HEAT
THIS WEEKEND WILL PASS VIRTUALLY OVERHEAD SUNDAY...THEN OFFSHORE
MONDAY. THIS WILL SHIFT THE DEEP-LAYER FLOW AROUND TO THE SOUTH ON
MONDAY... WITH DECREASING 850 MB TEMPS AND 1000-500 MB THICKNESSES
SHOWN ON GFS/ECMWF MODEL PLOTS. MONDAY`S HIGHS SHOULD THEREFORE RUN
A FEW DEGREES COOLER THAN ON SUNDAY. COOLING AND MOISTENING
MID-LEVELS SHOULD FAVOR BETTER A LITTLE CONVECTIVE POTENTIAL MONDAY
AS WELL.
BY TUESDAY THE PATTERN BECOMES EVEN MORE FAVORABLE FOR CONVECTION AS
A SYNOPTIC SURFACE FRONT DROPS SOUTH INTO THE CAROLINAS AND DEEP
MOISTURE INCREASES ALOFT AHEAD OF A DEVELOPING LONGWAVE TROUGH
EXTENDING FROM THE GREAT LAKES DOWN TO THE GULF COAST. GFS AND ECMWF
FORECAST SOUNDINGS SHOW AN UNCAPPED TROPICAL AIRMASS WITH SLIGHTLY
STEEPER THAN MOIST-ADIABATIC LAPSE RATES PERSISTING FOR SEVERAL DAYS
THIS WEEK...WITH PRECIP WATER INCREASING TO NEAR 2.0 INCHES. WE`VE
INCREASED THE AREA OF 40-50 PERCENT 12-HR POPS FORECAST TUESDAY
THROUGH THURSDAY AS THIS PATTERN CERTAINLY SHOULD EXCEED THE
CLIMATOLOGICAL 20-30 PERCENT 12-HR POP FOR THIS TIME OF YEAR.
UNIDIRECTIONAL SOUTH-SOUTHWEST WINDS AND MODEST LAPSE RATES WILL
SUPPORT HEAVY RAINFALL BUT NOT NECESSARILY SEVERE WEATHER.
DIURNAL TEMPERATURE RANGES WILL BECOME CONSTRICTED TUESDAY THROUGH
THURSDAY BY THE ADDITIONAL CLOUDS AND PRECIP...WITH HIGHS AVERAGING
IN THE UPPER 80S. LOWS SHOULD RANGE FROM 70-75.
&&
.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
AS OF 00Z...EXPECT VFR THROUGH THE VALID PERIOD WITH EXCEPTION OF
POSSIBLE BRIEF MVFR DUE TO PATCHY FOG EARLY FRIDAY MORNING AND IN
ANY CONVECTION THROUGH THE EARLY OVERNIGHT HOURS AND AGAIN DURING
FRIDAY AFTERNOON.
AFTER A FEW ISOLATED PULSE THUNDERSTORMS LATE THIS
AFTERNOON...CURRENT RADAR IMAGERY CONTINUES TO LIGHT UP WITH PULSE
CONVECTION ACROSS THE CAROLINAS. SOME OF THESE THUNDERSTORMS ARE
JUST ON THE FRINGE OF OUR CWA AND ANTICIPATE THIS CONVECTION TO
MOVE INTO THE INLAND SITES WITHIN THE NEXT HOUR. GIVEN CONTINUED
FAVORABLE STATE OF ATMOSPHERE...HAVE KEPT IN VCTS/VCSH AT ALL
SITES THROUGH THE EARLY OVERNIGHT HOURS. ANTICIPATE ANY CONVECTION
TO GRADUALLY TAPER OFF LATE OVERNIGHT LEAVING FEW MID TO HIGH-
LEVEL CLOUD DEBRIS TO LINGER ACROSS THE AREA WITH SOUTH- SOUTHWEST
WINDS AOB 10 KTS. THOUGH CONDITIONS WILL BE IDEAL FOR RADIATIONAL
COOLING...EXPECT INCREASED WINDS TO INHIBIT ANY FOG FORMATION
GIVEN INCREASED LOW LEVEL JET. HOWEVER...CANNOT COMPLETELY RULE
OUT BRIEF PATCHY MVFR FOG EARLY FRIDAY MORNING...ESPECIALLY AT
INLAND SITES.
AFTER DAYBREAK...SOUTHWEST WINDS WILL CONTINUE AND INCREASE
THROUGHOUT THE DAY TO AOB 10 KTS WITH GUSTS NEAR 15 KTS POSSIBLE
ALONG THE COAST. CANNOT RULE OUT ISOLATED TO SCATTERED CONVECTION
DURING THE AFTERNOON AND EVENING HOURS...THUS HAVE INTRODUCED VCTS.
EXTENDED OUTLOOK...A CHANCE OF THUNDERSTORMS EACH DAY...MAINLY IN
THE AFTERNOON AND EVENING. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 730 PM THURSDAY...HAVE MADE NO SIGNIFICANT CHANGES TO ONGOING
FORECAST WITH THIS UPDATE. SW FLOW AROUND BERMUDA HIGH OF 10-20 KTS
PERSISTING ACROSS THE COASTAL WATERS...WITH BUOYS REPORTING SEAS OF
3-4 FT. THIS IS IN LINE WITH CURRENT FORECAST. STILL NOTE THAT HIGH
RES GUIDANCE IS DEPICTING THE DEVELOPMENT OF A STRONG LOW LEVEL JET
TONIGHT AS HIGH PRESSURE SINKS SOUTH ACROSS TENNESSEE. THIS COULD
ENHANCE WINDS ACROSS THE WATERS. HOWEVER...TEMPS 1200-1500 FT ABOVE
THE SURFACE SHOULD BE WARM ENOUGH THAT A WEAK INVERSION WILL DEVELOP
EVEN ACROSS THE WATERS (WATER TEMPS IN THE UPPER 70S ATTM) SO FULL
DOWNWARD MIXING IS NOT ANTICIPATED...AND WINDS/SEAS SHOULD REMAIN
BELOW ANY CAUTIONARY HEADLINE CRITERIA. FOR THIS REASON EXPECT
STATUS QUO...3-4 FT SEAS AND 10-20 KTS SW WINDS CONTINUING THROUGH
DAYBREAK...ALTHOUGH AN ISOLATED 5 FTER IS NOT OUT OF THE QUESTION
NEAR THE 20NM BOUNDARY WHERE WATER TEMPS ARE IN THE LOW 80S.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...SOUTHWEST FLOW WILL PERSIST OVER THE WATERS
THROUGH THE PERIOD BETWEEN A SURFACE TROUGH LOCATED OVER THE
INLAND CAROLINAS AND BERMUDA HIGH PRESSURE. THE MSLP GRADIENT
MAGNITUDE WILL INCREASE EACH AFTERNOON IN RESPONSE TO THE SEA
BREEZE.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 PM THURSDAY...HIGH PRESSURE WELL OFF THE U.S. EAST COAST
SHOULD CONTINUE TO PUMP A WARM AND HUMID AIRMASS ONSHORE THROUGH
EARLY NEXT WEEK. THE PIEDMONT TROUGH SUNDAY WILL BECOME REPLACED ON
MONDAY BY LOW PRESSURE ALONG A COLD FRONT DIPPING SOUTH FROM
VIRGINIA. THIS FRONT SHOULD REMAIN NORTH OF THE COASTAL WATERS...BUT
MAY GET CLOSE ENOUGH TO BRING INCREASING CHANCES OF SHOWERS AND
THUNDERSTORMS MONDAY INTO TUESDAY. OTHERWISE...SOUTHWEST WINDS 10-15
KNOTS MAY INCREASE TO NEAR 20 KNOTS NEARSHORE DURING THE AFTERNOONS
DUE TO THE SEA BREEZE CIRCULATION. SEAS SHOULD AVERAGE 2-4 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...HEAT ADVISORY FROM NOON TO 8 PM EDT FRIDAY FOR SCZ017-023-024-
032-033-039-053>056.
NC...HEAT ADVISORY FROM NOON TO 8 PM EDT FRIDAY FOR NCZ087-096-099-
105>110.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW/CRM
NEAR TERM...JDW
SHORT TERM...CRM
LONG TERM...TRA
AVIATION...SGL
MARINE...JDW/SHK/CRM
AREA FORECAST DISCUSSION
NWS RALEIGH NC
749 PM EDT THU JUL 5 2012
.SYNOPSIS...
AN UPPER LEVEL RIDGE EXTENDING EASTWARD FROM THE CENTRAL MISSISSIPPI
RIVER VALLEY TOWARD THE CAROLINAS WILL RESULT IN ABOVE NORMAL
TEMPERATURES THROUGH THE UPCOMING WEEKEND...WITH A CHANCE FOR
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON
AND EVENING HOURS EACH DAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1130 AM THURSDAY...
OVERVIEW:
NORTHWEST FLOW ALOFT WILL PREVAIL OVER THE CAROLINAS THROUGH
TONIGHT...ON THE EASTERN PERIPHERY OF AN UPPER LEVEL RIDGE CENTERED
OVER THE CENTRAL MS RIVER VALLEY. 14Z WV IMAGERY AND RUC DATA
INDICATED MULTIPLE MID/UPPER LEVEL DISTURBANCES EMBEDDED WITHIN NW
FLOW ALOFT OVER THE MID-ATLANTIC AND CAROLINAS.
TEMPERATURES:
THE 12Z GSO RAOB INDICATED A 1000-850 MB THICKNESS OF 1434 METERS
THIS MORNING. THIS IS CONSISTENT WITH THE LATEST MODEL GUIDANCE...
WHICH CONTINUES TO INDICATE 1000-850 MB THICKNESSES IN VICINITY OF
1455 METERS BY 00Z...ROUGHLY 10-15 METERS HIGHER THAN YESTERDAY.
MODEL GUIDANCE INDICATES H85 TEMPS IN THE 21-23C RANGE THIS
AFTERNOON...GENERALLY CONSISTENT WITH UPSTREAM CONDITIONS PER 14Z
SPC MESOANALYSIS (THOUGH COOLER TEMPS ARE PRESENT OVER WV IN ASSOC/W
MCS REMNANTS). HIGHS YESTERDAY RANGED FROM 95-98F IN MOST
LOCATIONS...RDU AN EXCEPTION AT 101F. BASED ON YESTERDAY`S TEMPS AND
A 10-15 METER INCREASE IN THICKNESSES...EXPECT HIGHS IN VICINITY OF
100F TODAY...THOUGH ISOLD/SCT CONVECTION MAY PREVENT HIGHS FROM
EXCEEDING THE MID/UPPER 90S IN SOME LOCATIONS. DECIDED TO INCREASE
THE HIGH AT RDU TO 102F BASED ON YESTERDAY`S READING. WILL DECREASE
HIGHS A FEW DEGREES LOWER THAN WHAT THICKNESSES SUGGEST IN THE FAR
NW PIEDMONT WHERE OUTFLOW FROM MCS REMNANTS (AND NEWLY DEVELOPED
CONVECTION NEAR BLUEFIELD WV) MAY AFFECT TEMPS BY EARLY/MID
AFTERNOON. H85 DEWPOINTS RANGED FROM 13-15C (55-60F) ACROSS THE AREA
AT 14Z...AND SHOULD REMAIN IN THAT VICINITY THROUGH THE AFTERNOON.
GIVEN STRONG HEATING AND MIXING UP TO AT LEAST H85...ANTICIPATE THAT
DEWPOINTS WILL MIX OUT INTO THE LOWER/MID 60S IN THE NORTHERN AND
WESTERN PIEDMONT. IN THE SANDHILLS AND COASTAL PLAIN ON THE EASTERN
PERIPHERY OF THE LEE TROUGH...EXPECT DEWPOINTS WILL LIKELY REMAIN IN
THE UPPER 60S TO LOWER 70S GIVEN RELATIVELY HIGHER H85 DEWPOINTS IN
THE PRESENCE OF SHALLOW LOW-LEVEL CONVERGENCE AND MOISTURE POOLING.
EXPECT OVERNIGHT LOWS A BIT WARMER THAN THIS MORNING DUE TO AIRMASS
MODIFICATION...IN THE LOWER/MID 70S...OR 72-75F.
HEAT INDICES/HEAT ADVISORY:
WITH THE ABOVE T/TD DISCUSSION IN MIND...ANTICIPATE MAX HEAT INDICES
BETWEEN 105-110F IN THE ADVISORY AREA...WITH HEAT INDICES
APPROACHING 105F IN THE TRIANGLE...AND GENERALLY 100-105F IN THE
WESTERN PIEDMONT. DESPITE MAX HEAT INDICES FORECAST NEAR 105F IN
WAKE/FRANKLIN/WARREN COUNTIES...DECIDED NOT TO EXPAND THE HEAT
ADVISORY TO INCLUDE THOSE COUNTIES GIVEN A FAIR AMOUNT OF
UNCERTAINTY W/REGARD TO DEWPOINTS ALONG/WEST OF HWY 1 AND CONVECTIVE
EVOLUTION MID/LATE AFTERNOON.
PRECIPITATION CHANCES:
MID-LEVEL LAPSE RATES ARE SEASONABLY STEEP TODAY ACCORDING TO 15Z
SPC MESOANALYSIS DATA...IN VICINITY OF 6.5 C/KM. GIVEN SURFACE TEMPS
EASILY IN THE MID/UPPER 90S AND DEWPOINTS RANGING FROM THE LOWER/MID
60S TO NEAR 70F (IN ANTICIPATION OF SOME MIX-DOWN BY 18-21Z)...
EXPECT MLCAPE VALUES SOLIDLY IN THE MODERATE RANGE...PERHAPS
STRONG...GENERALLY BETWEEN 1500-2500 J/KG. W/REGARD TO FORCING... A
COMPLEX NW FLOW ALOFT PATTERN IS PRESENT OVER CENTRAL NC...WITH AT
LEAST SEVERAL IMPORTANT FEATURES. 1) A SHORTWAVE IN VICINITY OF CAPE
FEAR IS PROGGED TO TRACK SOUTHWARD INTO EASTERN SC/OFFSHORE AS THE
AFTERNOON PROGRESSES...AND SUBSIDENCE IN THE WAKE OF THIS FEATURE
MAY INITIALLY SUPPRESS DEVELOPMENT OVER THE COASTAL PLAIN...
ESPECIALLY IN THE SE COASTAL PLAIN. 2) THE REMNANTS OF AN MCS OVER
NORTHERN VA AT 03Z HAVE PROGRESSED INTO CENTRAL NC EARLY THIS
AFTERNOON. HOWEVER...FORCING ASSOC/W THIS FEATURE IS DIFFICULT TO
ASCERTAIN. 3) THE REMNANTS OF AN MCS OVER OHIO AT 03Z HAVE
PROGRESSED INTO SOUTHWEST VA BY 17Z THIS AFTERNOON...ALREADY FORCING
CONVECTION ALONG THE I-77 CORRIDOR IN NORTHWEST NC. 4) AN ONGOING
MCS IN WV AT 17Z...THOUGH EXPECTED TO TRACK INTO THE FAR WESTERN
PORTIONS OF THE STATE. ADDITIONALLY...A SURFACE TROUGH AXIS IN
VICINITY OF THE HWY 1 CORRIDOR WILL PROVIDE A LOW-LEVEL FOCUS FOR
CONVECTION THIS AFT/EVE. WITH THE ABOVE IN MIND...WILL INDICATE
PRECIP CHANCES 30-40% IN THE FAR WESTERN PIEDMONT...AND 20-30% IN
VICINITY OF THE HWY 1 CORRIDOR...AND ~20% IN THE CENTRAL/SE COASTAL
PLAIN.
SEVERE THREAT:
MLCAPE SOLIDLY IN THE MODERATE RANGE WILL RESULT IN ROBUST UPDRAFTS
TODAY...THOUGH DEEP-LAYER SHEAR WILL BE NO MORE THAN 15-20 KT.
HOWEVER...DUE TO LARGE T/TD SPREADS AND VERY HIGH DCAPE VALUES
ANALYZED PER LATEST SPC MESOANALYSIS (1000-1600 J/KG...HIGHEST
WEST)...EXPECT MULTICELL ORGANIZATION PRIMARILY ALONG OUTFLOW.
THOUGH HAIL UP TO THE SIZE OF QUARTERS WILL BE POSSIBLE GIVEN
MODERATE INSTABILITY...THE PRIMARY THREAT WILL BE ASSOCIATED WITH
DAMAGING WINDS OWING TO VERY HIGH DCAPE VALUES/STRONG BOUNDARY LAYER
EVAPORATIVE COOLING POTENTIAL. THE THREAT FOR SEVERE WEATHER WILL BE
HIGHEST IN THE WESTERN PIEDMONT (WHERE THE SLIGHT RISK IS INDICATED
ON THE DAY 1 OUTLOOK) BETWEEN 1 PM THIS AFTERNOON AND 8-11 PM THIS
EVENING. THIS IS WHERE THE HIGHEST DCAPE VALUES ARE PRESENT AND
WHERE THE RELATIVE BEST MID LEVEL FORCING IS EXPECTED AS REMNANT MCS
ACTIVITY PROGRESSES SOUTH/SSW INTO WESTERN PORTIONS OF THE STATE.
ISOLATED SEVERE WEATHER WILL BE POSSIBLE ELSEWHERE CONVECTION IS
PRESENT OWING TO 1000+ J/KG OF DCAPE/STEEP LOW-LEVEL LAPSE RATES IN
THE PRESENCE OF MODERATE INSTABILITY. -VINCENT
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 220 PM THURSDAY...
THE MID LEVEL RIDGE CURRENTLY CENTERED TO OUR WEST OVER THE CENTRAL
PLAINS WILL EXPAND EASTWARD AS THE TROUGH OFF THE NEW ENGLAND COAST
MOVES EAST. AT THE SFC AND LOWER LEVELS...NOT MUCH WILL CHANGE WITH
THE LEE TROUGH REMAINING IN PLACE. LOW LEVEL THICKNESSES ARE PROGGED
TO REMAIN THE SAME...THUS EXPECT HIGHS TOMORROW VERY SIMILAR TO
TODAYS VALUES...AROUND 100 ACROSS MUCH OF OUR CWA. GUIDANCE IS IN
GOOD AGREEMENT THAT DWPTS WILL BE LOWER ACROSS OUR WESTERN ZONES
(UPPER 60S WEST TO LOWER 70S EAST)...THUS HEAT INDEX VALUES WILL
RANGE FROM 100-103 WEST TO 104-107 EAST. THE HEAT ADVISORY THAT IS
ALREADY IN EFFECT FROM 11 AM TO 8 PM FRIDAY LOOKS GOOD AND WILL
LEAVE AS-IS. AS FOR TSTM POTENTIAL ON FRIDAY...NOTED SUBTLE
MID-LEVEL WARMING IN FORECAST SOUNDINGS BUT STILL ENOUGH MOISTURE
AND INSTABILITY/CAPE TO SEE SOME AFTERNOON TSTMS. GFS DEPICTS A WEAK
MID LEVEL SHEAR AXIS MOVING SOUTHEAST ACROSS THE STATE LATE IN THE
DAY. THUS EXPECT ISOLATED TO SCATTERED TSTMS...WITH PERHAPS THE
BETTER CHANCE FOR TSTMS ACTIVITY AND STRONGER INTENSITY WILL BE
ACROSS OUR EASTERN PIEDMONT AND COASTAL PLAIN ZONES WHERE FORECAST
SOUNDINGS AND SFC DWPT PROGS SUGGEST BETTER CAPE. ANY ACTIVITY WILL
WIND DOWN DURING THE LATE EVENING WITH PC CONDITIONS AT NIGHT. LOWS
FRI NIGHT IN THE LOW-MID 70S.
ON SATURDAY THE MID LEVEL RIDGE WILL BUILD OVER TOP OF CENTRAL NC...
WITH CONTINUED MID LEVEL WARMING. WITH 850 MB TEMPS WARMING AND LOW
LEVEL THICKNESSES INCREASING...EXPECT ANOTHER HOT DAY WITH HIGHS
ONCE AGAIN AROUND 100. HEAT ADVISORIES MAY ONCE AGAIN BE NEEDED.
WITH THE AFOREMENTIONED MID LEVEL WARMING AND WEAKENING LAPSE
RATES...TSTM COVERAGE SHOULD BE FURTHER REDUCED. BEST CHANCE WILL
CONTINUE TO BE ACROSS OUR EASTERN ZONES WHERE HIGHER PW AND DWPTS
ARE LOCATED. LITTLE CHANGE SATURDAY NIGHT...LOWS IN THE MID 70S.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 220 PM THURSDAY...
ON SUNDAY THE MID LEVEL RIDGE WILL MOVE EAST AS A POTENT SHORT WAVE
MOVES SE ACROSS THE GREAT LAKES. A COLD FRONT WILL BE MOVING ACROSS
THE OH RIVER VALLEY. SUNDAY SHOULD BE THE LAST HOT DAY IN THE
FORECAST PERIOD WITH LITTLE OR NO AIRMASS CHANGE FROM PREVIOUS DAYS.
EXPECT HIGHS ONCE AGAIN AROUND 100. WITH MID LEVELS BEGINNING TO
COOL AND PWAT INCREASING AHEAD OF THE TROUGH...WILL CONTINUE WITH
ISOLD TO SCATTERED AFTERNOON AND EVENING TSTMS.
MONDAY WILL BE A TRANSITION DAY AS THE LONGWAVE TROUGH DEEPENS
ACROSS THE EASTERN HALF OF THE COUNTRY AND THE ASSOC COLD FRONT
STALLS ACROSS THE CAROLINAS. THIS PATTERN WILL THEN REMAIN WITH US
THROUGH MUCH OF THE WEEK...RESULTING IN AT LEAST A GOOD CHANCE FOR
SHOWERS AND TSTMS EACH DAY AND NEAR SEASONABLE TEMPS.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 730 PM THURSDAY...
THE CONVECTION THAT DEVELOPED THIS AFTERNOON HAS DECREASED IN
COVERAGE...WITH ONLY SOME ACTIVITY REMAINING ACROSS THE SOUTHERN
PORTIONS OF THE FORECAST AREA...POSSIBLY IMPACTING KFAY OVER THE
NEXT HOUR OR SO. THIS ACTIVITY WILL DECREASE IN INTENSITY AS IT
CONTINUES TO MOVE SOUTH AND OUT OF THE FORECAST AREA DURING THE NEXT
COUPLE OF HOURS. AM EXPECTING MOSTLY VFR CONDITIONS FOR THE NEXT 24
HOURS...WITH A FEW EXCEPTIONS. FIRST...AS HAS BEEN THE CASE THE PAST
SEVERAL NIGHT...THERE IS THE POTENTIAL FOR SOME BRIEF PATCHY MVFR
FOG...MOST LIKELY AFFECTING KRWI...JUST BEFORE SUNRISE ON FRIDAY.
SECOND...ANOTHER ROUND OF CONVECTION ON FRIDAY AFTERNOON/EVENING MAY
BRING BRIEF PERIODS OF MVFR CONDITIONS TO THE AREA...BUT HAVE NOT
MENTIONED THUNDER IN THE TAFS AT THIS TIME AS CONFIDENCE IN TIMING
AND LOCATION IS LOW.
OUTLOOK....MAINLY VFR CONDITIONS ARE EXPECTED FOR THE REMAINDER OF
THE PERIOD AS AN AREA OF HIGH PRESSURE ALOFT EXTENDS ACROSS THE
CAROLINAS. THIS WEATHER SYSTEM WILL INHIBIT THE DEVELOPMENT OF
WIDESPREAD CONVECTION...ALTHOUGH ISOLATED DIURNAL STORMS CANNOT BE
RULED OUT THROUGH THE PERIOD. PRECIP CHANCES AND RESULTANT ADVERSE
AVIATION CONDITIONS MAY INCREASE BY THE BEGINNING OF NEXT WEEK AS A
FRONT APPROACHES THE REGION.
&&
.CLIMATE...
HIGH TEMPERATURE RECORDS AND YEAR RECORD LAST SET.
RALEIGH-DURHAM... GREENSBORO...
07/05 102 1999 98 1990
07/06 102 1999 100 1977
07/07 102 2010 101 1977
07/08 103 1977 102 1977
FAYETTEVILLE...
07/05 101 2002
07/06 99 1990
07/07 103 2010
07/08 102 1977
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM 11 AM THIS MORNING TO 9 PM EDT THIS EVENING
FOR NCZ011-027-028-042-043-077-078-085-086-088-089.
HEAT ADVISORY FROM 11 AM TO 8 PM EDT FRIDAY FOR NCZ008>011-
025>028-040>043-074>078-083>086-088-089.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...NP
LONG TERM...NP
AVIATION...KRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
737 PM EDT THU JUL 5 2012
.SYNOPSIS...
BERMUDA HIGH PRESSURE OFFSHORE AND THE PIEDMONT TROUGH INLAND WILL
PREVAIL THROUGH MUCH OF THE FORECAST PERIOD...BRINGING HOT AND HUMID
CONDITIONS WITH ISOLATED THUNDERSTORMS EACH AFTERNOON AND EVENING.
AN UPPER RIDGE OVER THE AREA WILL SLOWLY WEAKEN NEXT WEEK...BRINGING
DAYTIME TEMPERATURES CLOSER TO NORMAL FOR JULY. AN APPROACHING
COLD FRONT WILL STALL NEAR THE AREA BEGINNING TUESDAY...BRINGING
INCREASED RAIN CHANCES THROUGH MUCH OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 730 PM THURSDAY...WATER VAPOR IMAGERY COMBINED WITH SURFACE
ANALYSIS PAINTS THE PICTURE THIS EVENING...WITH SURFACE HIGH
PRESSURE SINKING SOUTH ACROSS EASTERN TENNESSEE AND A LARGE UPPER
RIDGE HOLDING FIRM ACROSS THE MIDWEST. AT THE SAME TIME...SOUTHWEST
MONSOON MOISTURE IS WRAPPING UP ALONG THE WESTERN EDGE OF THE RIDGE
IN NM/CO...AND ROTATING BACK DOWN THE EASTERN PERIPHERY IN THE
APPALACHIANS...HELPING TO FUEL OUR STORMS TONIGHT.
ADDITIONALLY...S/SW RETURN FLOW AROUND OFFSHORE BERMUDA HIGH HAS
HELPED DRIVE DEWPOINTS WELL INTO THE 70S MOST LOCATIONS.
THE AMPLE HEATING THAT OCCURRED TODAY (MANY SPOTS STILL HAVE HI`S
NEAR 105F AT THIS HOUR) HELPED PUSH SBCAPE ABOVE 3000 J/KG...AND
ALTHOUGH PARCELS ARE RAPIDLY BECOMING CAPPED TO SURFACE BASED
INSTABILITY DUE TO LOSS OF HEATING...RUC/NAM FORECAST SOUNDINGS
SUGGEST ELEVATED INSTABILITY ROOTED AROUND 900MB WILL PERSIST WELL
INTO THE NIGHT. MLCAPES OF 1500 J/KG ARE PROGGED TO REMAIN THROUGH
MIDNIGHT...WITH LI`S AROUND -7 AND DECENT COLUMN MOISTURE UP THROUGH
600MB. AT THE SAME TIME...WV IMAGERY SUGGESTS A RATHER POTENT
IMPULSE ROTATING DOWN THROUGH VA/NC ATTM WHICH WILL LIKELY AID IN
CONTINUING CONVECTION EVEN AFTER NIGHTFALL...IF NOT LOCALLY
ENHANCING IT. NOTE THAT THE HRRR HAS NOT BEEN SHOWING MUCH OF ANY
NOCTURNAL CONVECTION...BUT THE HIGH RES ARW...WHICH HAS DONE THE
BEST RECENTLY AND IS PERFORMING WELL TONIGHT...KEEPS SCATTERED
CONVECTION NEAR THE AREA THROUGH APPROX 1AM. UPSTREAM CONVECTION
ALONG A COMBINATION OF THE PIEDMONT TROUGH AND RESIDUAL OUTFLOWS IS
SLOWLY WORKING SOUTH (DUE TO WEAK STEERING FLOW) AND THIS WILL
BECOME THE PRIMARY SHOW. EXACTLY HOW STRONG CONVECTION WILL BE IS
STILL TO BE SEEN...BUT ISOLATED STRONG TO DAMAGING WIND GUSTS ARE
NOT OUT OF THE QUESTION FOR A FEW MORE HOURS. THE BEST CHANCE OF
TSTMS WILL BE ACROSS NORTHERN AND WESTERN ZONES.
THE HEAT ADVISORY WILL BE ALLOWED TO EXPIRE ON TIME AT 9PM...AND
MINS TONIGHT WILL REMAIN RATHER ELEVATED SINCE FULL DECOUPLING IS
NOT EXPECTED. AS SURFACE HIGH SINKS SOUTH...A STRONG LLJ OF 25-30
KTS AT 900MB SHOULD DEVELOP WHICH WILL COMBINE WITH MID LEVEL
MOISTURE TO KEEP MINS FROM FALLING OFF TOO QUICKLY. HAVE LEANED MORE
TOWARDS THE WARMER NAM GUIDANCE...WITH LOWS IN THE MID 70S
INLAND...TO NEAR 80 AT THE IMMEDIATE COAST.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...MID/UPPER LEVEL RIDGE OVER THE CENTRAL
CONUS ON FRIDAY WILL FLATTEN AND SPREAD EASTWARD ON SATURDAY...
WITH INCREASING HEIGHTS OVER THE CWA THROUGH THE PERIOD. TIME-
HEIGHT CROSS SECTIONS SHOW A LAYER OF RELATIVELY DRY AIR BETWEEN
700-400 MB...WITH ONLY MODEST MOISTURE BELOW 700 MB. A DEEP LAYER
OF SUBSIDENCE IS ALSO NOTED IN RESPONSE TO THE INCREASING HEIGHTS.
ALTHOUGH DEEP MOISTURE IS LACKING...SURFACE DEWPOINTS IN THE MID
70S COMBINED WITH SB CAPE TO 2500 J/KG AND LI`S TO -6C WILL MAKE IT
TOUGH TO RULE OUT THE CHANCE FOR CONVECTION ALTOGETHER. ISOLATED
DEVELOPMENT WILL BE POSSIBLE FRIDAY AND SATURDAY ALONG THE SEA
BREEZE AND PIEDMONT TROUGH...BUT EXPECT CHANCES TO BE HIGHER
FRIDAY AS A SUBTLE MID-LEVEL SHORTWAVE DROPS SOUTH ACROSS THE
AREA DURING MIDDAY HEATING. ALSO NOTABLE LATE FRIDAY NIGHT AND
THROUGH SATURDAY IS DEEP ONSHORE FLOW ABOVE 700 MB. ANY CONVECTION
THAT DEVELOPS OVER THE WATERS WILL BE STEERED TOWARDS SHORE.
GIVEN WIDESPREAD HIGHS EXPECTED TO BE IN THE MID AND UPPER
90S FRIDAY AND SATURDAY...AND DEWPOINTS IN THE MID 70S...HEAT INDICES
SHOULD REACH 105 AT MANY LOCATIONS. THEREFORE WILL RAISE ANOTHER
HEAT ADVISORY FOR FRIDAY...AND ONE MAY BE REQUIRED FOR SATURDAY ALSO.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...SUNDAY SHOULD BE THE LAST DAY OF EXTREME
HEAT. HIGH TEMPERATURES IN THE UPPER 90S AWAY FROM THE COAST COUPLED
WITH MID-70S DEWPOINTS SHOULD AGAIN YIELD HEAT INDICES ABOVE 105
DEGREES DURING THE DAY. THE HOT UPPER LEVEL RIDGE CAUSING THE HEAT
THIS WEEKEND WILL PASS VIRTUALLY OVERHEAD SUNDAY...THEN OFFSHORE
MONDAY. THIS WILL SHIFT THE DEEP-LAYER FLOW AROUND TO THE SOUTH ON
MONDAY... WITH DECREASING 850 MB TEMPS AND 1000-500 MB THICKNESSES
SHOWN ON GFS/ECMWF MODEL PLOTS. MONDAY`S HIGHS SHOULD THEREFORE RUN
A FEW DEGREES COOLER THAN ON SUNDAY. COOLING AND MOISTENING
MID-LEVELS SHOULD FAVOR BETTER A LITTLE CONVECTIVE POTENTIAL MONDAY
AS WELL.
BY TUESDAY THE PATTERN BECOMES EVEN MORE FAVORABLE FOR CONVECTION AS
A SYNOPTIC SURFACE FRONT DROPS SOUTH INTO THE CAROLINAS AND DEEP
MOISTURE INCREASES ALOFT AHEAD OF A DEVELOPING LONGWAVE TROUGH
EXTENDING FROM THE GREAT LAKES DOWN TO THE GULF COAST. GFS AND ECMWF
FORECAST SOUNDINGS SHOW AN UNCAPPED TROPICAL AIRMASS WITH SLIGHTLY
STEEPER THAN MOIST-ADIABATIC LAPSE RATES PERSISTING FOR SEVERAL DAYS
THIS WEEK...WITH PRECIP WATER INCREASING TO NEAR 2.0 INCHES. WE`VE
INCREASED THE AREA OF 40-50 PERCENT 12-HR POPS FORECAST TUESDAY
THROUGH THURSDAY AS THIS PATTERN CERTAINLY SHOULD EXCEED THE
CLIMATOLOGICAL 20-30 PERCENT 12-HR POP FOR THIS TIME OF YEAR.
UNIDIRECTIONAL SOUTH-SOUTHWEST WINDS AND MODEST LAPSE RATES WILL
SUPPORT HEAVY RAINFALL BUT NOT NECESSARILY SEVERE WEATHER.
DIURNAL TEMPERATURE RANGES WILL BECOME CONSTRICTED TUESDAY THROUGH
THURSDAY BY THE ADDITIONAL CLOUDS AND PRECIP...WITH HIGHS AVERAGING
IN THE UPPER 80S. LOWS SHOULD RANGE FROM 70-75.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 00Z...EXPECT VFR THROUGH THE VALID PERIOD WITH EXCEPTION OF
POSSIBLE BRIEF MVFR DUE TO PATCHY FOG EARLY FRIDAY MORNING AND IN
ANY CONVECTION THROUGH THE EARLY OVERNIGHT HOURS AND AGAIN DURING
FRIDAY AFTERNOON.
AFTER A FEW ISOLATED PULSE THUNDERSTORMS LATE THIS
AFTERNOON...CURRENT RADAR IMAGERY CONTINUES TO LIGHT UP WITH PULSE
CONVECTION ACROSS THE CAROLINAS. SOME OF THESE THUNDERSTORMS ARE
JUST ON THE FRINGE OF OUR CWA AND ANTICIPATE THIS CONVECTION TO
MOVE INTO THE INLAND SITES WITHIN THE NEXT HOUR. GIVEN CONTINUED
FAVORABLE STATE OF ATMOSPHERE...HAVE KEPT IN VCTS/VCSH AT ALL
SITES THROUGH THE EARLY OVERNIGHT HOURS. ANTICIPATE ANY CONVECTION
TO GRADUALLY TAPER OFF LATE OVERNIGHT LEAVING FEW MID TO HIGH-
LEVEL CLOUD DEBRIS TO LINGER ACROSS THE AREA WITH SOUTH- SOUTHWEST
WINDS AOB 10 KTS. THOUGH CONDITIONS WILL BE IDEAL FOR RADIATIONAL
COOLING...EXPECT INCREASED WINDS TO INHIBIT ANY FOG FORMATION
GIVEN INCREASED LOW LEVEL JET. HOWEVER...CANNOT COMPLETELY RULE
OUT BRIEF PATCHY MVFR FOG EARLY FRIDAY MORNING...ESPECIALLY AT
INLAND SITES.
AFTER DAYBREAK...SOUTHWEST WINDS WILL CONTINUE AND INCREASE
THROUGHOUT THE DAY TO AOB 10 KTS WITH GUSTS NEAR 15 KTS POSSIBLE
ALONG THE COAST. CANNOT RULE OUT ISOLATED TO SCATTERED CONVECTION
DURING THE AFTERNOON AND EVENING HOURS...THUS HAVE INTRODUCED VCTS.
EXTENDED OUTLOOK...A CHANCE OF THUNDERSTORMS EACH DAY...MAINLY IN
THE AFTERNOON AND EVENING. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 730 PM THURSDAY...HAVE MADE NO SIGNIFICANT CHANGES TO ONGOING
FORECAST WITH THIS UPDATE. SW FLOW AROUND BERMUDA HIGH OF 10-20 KTS
PERSISTING ACROSS THE COASTAL WATERS...WITH BUOYS REPORTING SEAS OF
3-4 FT. THIS IS IN LINE WITH CURRENT FORECAST. STILL NOTE THAT HIGH
RES GUIDANCE IS DEPICTING THE DEVELOPMENT OF A STRONG LOW LEVEL JET
TONIGHT AS HIGH PRESSURE SINKS SOUTH ACROSS TENNESSEE. THIS COULD
ENHANCE WINDS ACROSS THE WATERS. HOWEVER...TEMPS 1200-1500 FT ABOVE
THE SURFACE SHOULD BE WARM ENOUGH THAT A WEAK INVERSION WILL DEVELOP
EVEN ACROSS THE WATERS (WATER TEMPS IN THE UPPER 70S ATTM) SO FULL
DOWNWARD MIXING IS NOT ANTICIPATED...AND WINDS/SEAS SHOULD REMAIN
BELOW ANY CAUTIONARY HEADLINE CRITERIA. FOR THIS REASON EXPECT
STATUS QUO...3-4 FT SEAS AND 10-20 KTS SW WINDS CONTINUING THROUGH
DAYBREAK...ALTHOUGH AN ISOLATED 5 FTER IS NOT OUT OF THE QUESTION
NEAR THE 20NM BOUNDARY WHERE WATER TEMPS ARE IN THE LOW 80S.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...SOUTHWEST FLOW WILL PERSIST OVER THE WATERS
THROUGH THE PERIOD BETWEEN A SURFACE TROUGH LOCATED OVER THE
INLAND CAROLINAS AND BERMUDA HIGH PRESSURE. THE MSLP GRADIENT
MAGNITUDE WILL INCREASE EACH AFTERNOON IN RESPONSE TO THE SEA
BREEZE.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 PM THURSDAY...HIGH PRESSURE WELL OFF THE U.S. EAST COAST
SHOULD CONTINUE TO PUMP A WARM AND HUMID AIRMASS ONSHORE THROUGH
EARLY NEXT WEEK. THE PIEDMONT TROUGH SUNDAY WILL BECOME REPLACED ON
MONDAY BY LOW PRESSURE ALONG A COLD FRONT DIPPING SOUTH FROM
VIRGINIA. THIS FRONT SHOULD REMAIN NORTH OF THE COASTAL WATERS...BUT
MAY GET CLOSE ENOUGH TO BRING INCREASING CHANCES OF SHOWERS AND
THUNDERSTORMS MONDAY INTO TUESDAY. OTHERWISE...SOUTHWEST WINDS 10-15
KNOTS MAY INCREASE TO NEAR 20 KNOTS NEARSHORE DURING THE AFTERNOONS
DUE TO THE SEA BREEZE CIRCULATION. SEAS SHOULD AVERAGE 2-4 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR SCZ017-023-024-
032-033-039-053>056.
HEAT ADVISORY FROM NOON TO 8 PM EDT FRIDAY FOR SCZ017-023-024-
032-033-039-053>056.
NC...HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR NCZ087-096-099-
105-107-109.
HEAT ADVISORY FROM NOON TO 8 PM EDT FRIDAY FOR NCZ087-096-099-
105>110.
MARINE...NONE.
&&
$$
SYNOPSIS...CRM/JDW
NEAR TERM...JDW
SHORT TERM...CRM
LONG TERM...TRA
AVIATION...SGL
MARINE...JDW/SHK/CRM
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
311 PM EDT WED JUL 4 2012
.SYNOPSIS...
BERMUDA HIGH PRESSURE OFFSHORE AND THE PIEDMONT TROUGH INLAND WILL
PREVAIL THROUGH MUCH OF THE FORECAST PERIOD...BRINGING HOT AND HUMID
CONDITIONS WITH ISOLATED THUNDERSTORMS EACH AFTERNOON AND EVENING.
AN UPPER RIDGE OVER THE AREA WILL SLOWLY WEAKEN NEXT WEEK...BRINGING
DAYTIME TEMPERATURES DOWN CLOSER TO NORMAL READINGS FOR JULY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 130 PM WEDNESDAY...MAINLY JUST SEEING SOME HIGHER LEVEL
DEBRIS CLOUDS FILTERING OUT SOME OF THE SUN AS THEY PASS OVERHEAD FROM
THE NORTH. OTHER CU DEVELOPING ALONG PIEDMONT TROUGH INLAND AND
EXPECT SOME ALONG SEA BREEZE BOUNDARY CLOSER TO THE COAST.
BIG QUESTION FOR TODAY IS HOW MUCH TSTM ACTIVITY TO EXPECT.
SOUNDING ANALYSIS SHOWS MORE TYPICAL SUMMER TIME AIR MASS WITH
DEWPOINTS UP AROUND 70. CAPE AND MOST INDICES BECOMING LESS
IMPRESSIVE THIS AFTERNOON. PCP WATER REMAINS AROUND 1.5 INCHES
UNTIL LATER THIS AFTERNOON AT WHICH TIME IT SHOWS A SPIKE IN
VALUES TO OUR WEST...ASSOCIATED WITH DEVELOPMENT OF CONVECTION
THERE. THE SEA BREEZE SHOULD REMAIN CLOSER TO THE COAST INITIALLY
WITH THE WESTERLY COMPONENT TO LOW LEVEL FLOW BUT WILL MAKE ITS
WAY INLAND MID TO LATE AFTERNOON. THIS MAY PRODUCE AN ISOLATED
STORM CLOSER TO THE COAST BUT OVERALL EXPECT MOST ACTIVITY TO MOVE
INTO WESTERN COUNTIES FROM JUST WEST OF CWA LATER IN THE DAY. NAM
SHOWS IMPULSE IN MID TO UPPER FLOW REACHING OUR W-NW COUNTIES
BETWEEN 5 AND 8 PM...WHICH COINCIDES NICELY WITH HRRR FORECAST
FOR CONVECTION TO MOVE OVER WESTERN COUNTIES BETWEEN THE SAME
TIME. MAIN SHORTWAVE ENERGY RIDES OFF THE MID ATLANTIC COAST THIS
AFTN WITH PIECE DROPPING S-SE THROUGH THE AREA THIS
EVENING...REACHING THE COAST SHORTLY BEFORE MIDNIGHT. STORMS
SHOULD TRACK SLOWLY E-SE REMAINING SCT ACROSS INLAND CWA THROUGH
AT LEAST MIDNIGHT. ONCE THE HEATING DIMINISHES THIS EVENING AND
WITH MORE STABLE ATMOSPHERE BEHIND SEA BREEZE EXPECT STORMS TO
DISSIPATE AS THEY MOVE TOWARD THE COAST. THEREFORE WILL KEEP MAIN
POPS INLAND WITH ISO POPS ALONG COAST INTO TONIGHT AS THIS
FEATURE MOVES THROUGH. WITH STEERING FLOW OUT OF THE W-NW JUST
UNDER 10 MPH...ANY STORMS THAT DEVELOP WILL TRACK TOWARD THE
COAST.
WARM AND HUMID SUMMERTIME AIR MASS WILL MAINTAIN TEMPS IN THE MID
70S TONIGHT.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...VERY FEW CHANGES HAVE BEEN MADE TO THIS
PERIOD OF THE FORECAST. THE SUBTROPICAL RIDGE CENTERED OVER
MISSOURI AT 700-500 MB WILL EXPAND IN SIZE FRIDAY BUT WILL REMAIN
CENTERED TO OUR WEST. THIS MEANS A NORTH TO NORTHEASTERLY MID AND
UPPER LEVEL FLOW IS EXPECTED WITH THE EXPANSION OF THE RIDGE
TAKING PLACE MAINLY TO OUR NORTH. THERMALLY THE WARMEST 850 MB
TEMPERATURES AND 1000-500 MB THICKNESSES WILL REMAIN TO OUR NORTH
AS WELL...WITH AN "INVERTED" THERMAL GRADIENT BOTH DAYS FAVORING
THE HOTTEST TEMPERATURES ACROSS VIRGINIA AND NORTH CAROLINA AND
SOMEWHAT COOLER READINGS ACROSS SOUTH CAROLINA AND GEORGIA. AT THE
SURFACE HIGH PRESSURE WELL OFFSHORE WILL RIDGE WESTWARD ACROSS
FLORIDA JUST SOUTH OF 30 DEGREES NORTH LATITUDE. A THERMAL TROUGH
ACROSS THE INLAND CAROLINAS WILL TURN THE LOW-LEVEL WINDS SOUTHWESTERLY.
ADD IN A LARGE INLAND-TO-MARINE TEMPERATURE GRADIENT PRODUCING A
STRONG SEABREEZE AND THE BEACHES COULD BE LOOKING AT 20-25 MPH
WIND GUSTS BOTH THURSDAY AND FRIDAY AFTERNOONS.
CONVECTIVE POTENTIAL APPEARS FAIRLY LOW ALTHOUGH THE ATMOSPHERE
WILL HAVE LARGE POTENTIAL INSTABILITY BOTH DAYS. LIFTED INDICES AS
LOW AS -8 AND CAPE VALUES 2000-3500 J/KG THURSDAY WILL MODERATE ONLY
SLIGHTLY FRIDAY DUE TO WARMER MID AND UPPER LEVEL TEMPERATURES
NEAR THE BUILDING RIDGE. CONVECTION WILL PROBABLY FOCUS AROUND A
WEAK UPPER DISTURBANCE ACROSS EASTERN SOUTH CAROLINA ON
THURSDAY...AND ALONG THE SEABREEZE BOUNDARY AND PIEDMONT TROUGH BOTH
DAYS. PLENTY OF DRY AIR ALOFT PLUS VERY WEAK STEERING FLOW BOTH
ARGUE FOR LOW POPS. OUR FORECAST REMAINS ABOVE THE VERY LOW GFS AND
NAM MOS 12-HR POPS (BOTH NO HIGHER THAN 10% UNTIL FRIDAY NIGHT)
BUT IS LOWER THAN IN THE PREVIOUS OFFICIAL FORECAST.
LASTLY...WE`VE RAISED A HEAT ADVISORY FOR THE COUNTIES NEAR
INTERSTATE 95 ON THURSDAY WHERE HEAT INDICES COULD REACH 105.
THERE IS SOME POTENTIAL THAT ADDITIONAL AREAS WILL NEED TO BE
ADDED TO THE ADVISORY WHERE WE CURRENTLY HAVE 103-104 HEAT INDICES
FORECAST INCLUDING WILMINGTON...WHITEVILLE...CONWAY AND KINGSTREE.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 PM WEDNESDAY...HOT AND MOSTLY DRY CONDITIONS FOR THE
WEEKEND WILL GIVE WAY TO A COOLER AND MUCH WETTER PATTERN FOR THE
UPCOMING WORK WEEK.
LARGE UPPER RIDGE WHICH HAS BEEN DOMINATING THE CENTRAL PORTION OF
THE COUNTRY WILL STRETCH EAST AS THIS RIDGE ELONGATES INTO THE
CAROLINAS. THIS WILL BRING WARMING TEMPS TO THE REGION...WITH HIGHS
REACHING WELL INTO THE 90S AWAY FROM THE BEACHES...POTENTIALLY
TOUCHING 100 IN THE HOTTEST SPOTS...BOTH SATURDAY AND SUNDAY. WITH A
STRONG RIDGE IN PLACE WE TEND TO BE CAPPED TO
CONVECTION...HOWEVER...THE LOW PORTIONS OF THE COLUMN WARM ALMOST
UNIFORMLY...AND INSTEAD OF GETTING A STRONG CAPPING INVERSION WE END
UP WITH A SHALLOW SUB-ADIABATIC LAYER BETWEEN 850-800MB. ALTHOUGH
THIS WILL SQUELCH MOST ACTIVITY...AN ACTIVE PIEDMONT TROUGH MAY
STILL FIRE IN THE AFTN ALLOWING FOR ISOLATED TSTMS...SO AGREE WITH
INHERITED SCHC...MOSTLY INLAND. ADDITIONALLY...WITH SOUTHERLY RETURN
FLOW PERSISTING THROUGH THE WKND...TD/S WILL BE HIGH ENOUGH TO
POTENTIALLY RAISE HEAT INDICES TO HEAT-ADVISORY CRITERIA (105F+)
BOTH SAT AND SUN.
BIG CHANGES OCCUR EARLY MONDAY AS A VORT-IMPULSE PUSHES SE ACROSS
THE AREA AHEAD OF A 500MB TROUGH ADVANCING DOWN THE EAST COAST. THIS
IMPULSE COULD FIRE SOME CONVECTION EARLY MONDAY...BUT THE REAL
RAIN/TSTM CHANCES HOLD OFF UNTIL LATER MONDAY. AS THE 500MB TROUGH
PUSHES SOUTH...A SERIES OF UPPER IMPULSES HELP DRIVE A TROUGH (FRONT
WITH NO REAL AIRMASS CHANGE) TOWARDS THE CAROLINAS. AHEAD OF
THIS...STRONG THETA-E ADVECTION OCCURS FROM THE GULF COAST...AND
PWATS RISE TO NEARLY 2.5 INCHES BY LATE MONDAY. SOUNDINGS SUGGEST
DEEP COLUMN SATURATION WITH AMPLE INSTABILITY FOR CONVECTION...AND
EXPECT WIDESPREAD SHOWERS AND TSTMS BEGINNING MONDAY AND PERSISTING
THROUGH WEDNESDAY AS TROUGH MEANDERS OVER THE AREA. WILL BUMP POP TO
HIGH CHC BOTH MON AND TUE...LOWERING BY WEDNESDAY AS BEST MOISTURE
GETS SHUNTED SOUTH. TEMPS WILL BE HINDERED BY CLOUDS AND RAIN...AND
EXPECT MEX NUMBERS ARE TOO HIGH SINCE Q12 VALUES ARE NOW WELL ABOVE
CLIMO EVEN ON DAY 6/7. SO EXPECT TEMPS AROUND CLIMO MON-WED...BUT
MAY END UP BEING BELOW DEPENDING ON OVERALL CLOUD/TSTM COVERAGE.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 18Z...STAGNANT SYNOPTIC PATTERN WILL CONTINUE...WITH A
PERSISTENT THERMAL TROUGH. LOW LEVEL LAPSE RATES ARE QUITE
STEEP...BUT A SUBSIDENCE INVERSION AROUND 650 MB MAY KEEP A CAP ON
ANY CONVECTION FOR A WHILE. A STRUNG OUT VORT MAX...WEAKLY EVIDENT
ON WATER VAPOR...WILL DROP SOUTHWARD INTO THE CAROLINAS LATE THIS
AFTERNOON. MOST OF THE ENERGY IS OFFSHORE. THE WRF HAS A RATHER
LARGE COMPLEX OF STORMS DROPPING SOUTHEAST INTO THE NORTHEAST
PORTION OF THE CWA THIS EVENING. LOW CONFIDENCE ON THIS SCENARIO
RIGHT NOW...BUT GIVEN THE CAPE AND THE SEA BREEZE BOUNDARY...ANY
LITTLE IMPULSE COULD KICK OFF SOME GOOD STORMS. SOUTHWEST FLOW WILL
CONTINUE THIS AFTERNOON THROUGH THE OVERNIGHT HOURS.
EXTENDED OUTLOOK...A CHANCE OF THUNDERSTORMS EACH DAY...MAINLY IN
THE AFTERNOON AND EVENING. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 130 PM WEDNESDAY...SOUTHWEST FLOW WILL CONTINUE AROUND
BERMUDA HIGH WITH WINDS AROUND 10 TO 15 KTS WITH HIGHER GUSTS
THROUGH EARLY EVENING. THE SEA WILL BE DOMINATED BY WIND-DRIVEN
S TO SW WAVES OF 2-4 FEET RUNNING IN 5-6 SECONDS INTERVALS...AND
WEAKER BUT LONGER PERIOD SE WAVES OF 1-2 FT EVERY 9-10 SECONDS.
SPIKE IN WINDS OVERNIGHT UP TO 20 KTS IN OUTER WATERS MAY CAUSE
ISOLATED 5 FTERS OUT TOWARD FRYING PAN SHOALS. ISOLATED TSTMS
WILL REMAIN POSSIBLE THROUGH TONIGHT AS AN UPPER LEVEL IMPULSE
MOVES SE ACROSS THE WATERS OVERNIGHT.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...A TYPICAL MID-SUMMER WEATHER PATTERN IS
UPON US WITH HIGH PRESSURE WELL OFFSHORE RIDGING WEST ACROSS
FLORIDA...AND A PIEDMONT TROUGH STATIONARY ACROSS THE INLAND
CAROLINAS. THIS PATTERN TYPICALLY PRODUCES SOUTHWEST WINDS WITH
NEARSHORE ENHANCEMENT DUE TO THE AFTERNOON SEABREEZES. WIND SPEEDS
SHOULD AVERAGE 10-15 KNOTS...WITH THE SEABREEZE INCREASING
NEARSHORE SPEEDS TO 15-20 KNOTS FROM 2-8 PM BOTH DAYS. SEAS SHOULD
AVERAGE 2-4 FT.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 300 PM WEDNESDAY...TYPICAL SUMMERTIME PATTERN PERSISTS THROUGH
THE EXTENDED ACROSS THE COASTAL WATERS. LARGE BERMUDA HIGH PRESSURE
SITS OFFSHORE WHILE AN ACTIVE PIEDMONT TROUGH DEVELOPS EACH DAY.
THIS KEEPS THE WATERS IN BETWEEN...WITH A PINCHED GRADIENT AND
CONTINUED SW WINDS OF 10-20 KTS. WITH THE BERMUDA HIGH STAYING IN
PLACE...LONG EASTERLY FETCH BRINGS IN A DECENT 2-3FT/9SEC SE SWELL
EACH DAY...WHICH WILL BE TOPPED BY A 4-5FT/5SEC SW WIND WAVE. THESE
COMBINE TO PRODUCE 3-5 FT SEAS THROUGH THE PERIOD. ATTM NO
CAUTIONARY STATEMENTS ARE EXPECTED...BUT CURRENT FORECAST IS CLOSE
TO SCEC CRITERIA...SO WILL HAVE TO MONITOR WITH FUTURE UPDATES FOR
THIS POTENTIAL
&&
.TIDES/COASTAL FLOODING...
AS OF 2 PM WEDNESDAY...RECENT PASSING OF THE OFFICIAL FULL MOON WILL
LEAD TO HIGH ASTRONOMICAL TIDES ONCE AGAIN THIS EVENING. THIS WILL
KEEP WATER LEVELS ELEVATED AND FORECAST TO REACH NEAR FLOOD STAGE.
ISSUED COASTAL FLOOD ADVISORY FOR CAPE FEAR IN DOWNTOWN WILMINGTON
FOR MINOR FLOODING. LEVELS MADE IT TO 5.6 YESTERDAY EVENING AND
EXPECT SOMETHING SIMILAR THIS EVENING AROUND TIME OF HIGH
TIDE...SHORTLY AFTER 11 PM. SIGNIFICANT FLOODING IN PRONE AREAS
LOOKS TO REMAIN MINIMAL. FIREWORKS SHOW AT THE BATTLESHIP WILL DRAW
CROWDS...BUT RIGHT NOW AT WORSE WE COULD SEE SHALLOW ENCROACHMENT OF
WATER ON A FEW ROADS DOWNTOWN AND IT SHOULD COME AFTER THE FIREWORKS
DISPLAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...HEAT ADVISORY FROM 11 AM TO 9 PM EDT THURSDAY FOR SCZ017-023-
024-032-033.
NC...HEAT ADVISORY FROM 11 AM TO 9 PM EDT THURSDAY FOR NCZ087-096.
COASTAL FLOOD ADVISORY FROM 7 PM TO 10 PM EDT THIS EVENING FOR
NCZ107.
MARINE...NONE.
&&
$$
SYNOPSIS...TRA
NEAR TERM...RGZ
SHORT TERM...TRA
LONG TERM...JDW
AVIATION...RGZ/DL
TIDES/COASTAL FLOODING...RGZ
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
215 PM EDT WED JUL 4 2012
.SYNOPSIS...
BERMUDA HIGH PRESSURE OFFSHORE AND A THERMAL TROUGH INLAND WILL
PREVAIL THROUGH MUCH OF THE FORECAST PERIOD...BRINGING WARM AND
HUMID CONDITIONS WITH A CHANCE OF A THUNDERSTORM EACH AFTERNOON
AND EVENING. AN UPPER RIDGE OVER THE AREA WILL CONTINUE TO SLOWLY
WEAKEN...BRINGING DAYTIME TEMPERATURES CLOSER TO NORMAL READINGS
FOR EARLY JULY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 130 PM WEDNESDAY...MAINLY JUST SEEING SOME HIGHER LEVEL
DEBRIS CLOUDS FILTERING OUT SOME OF THE SUN AS THEY PASS OVERHEAD FROM
THE NORTH. OTHER CU DEVELOPING ALONG PIEDMONT TROUGH INLAND AND
EXPECT SOME ALONG SEA BREEZE BOUNDARY CLOSER TO THE COAST.
BIG QUESTION FOR TODAY IS HOW MUCH TSTM ACTIVITY TO EXPECT.
SOUNDING ANALYSIS SHOWS MORE TYPICAL SUMMER TIME AIR MASS WITH
DEWPOINTS UP AROUND 70. CAPE AND MOST INDICES BECOMING LESS
IMPRESSIVE THIS AFTERNOON. PCP WATER REMAINS AROUND 1.5 INCHES
UNTIL LATER THIS AFTERNOON AT WHICH TIME IT SHOWS A SPIKE IN
VALUES TO OUR WEST...ASSOCIATED WITH DEVELOPMENT OF CONVECTION
THERE. THE SEA BREEZE SHOULD REMAIN CLOSER TO THE COAST INITIALLY
WITH THE WESTERLY COMPONENT TO LOW LEVEL FLOW BUT WILL MAKE ITS
WAY INLAND MID TO LATE AFTERNOON. THIS MAY PRODUCE AN ISOLATED
STORM CLOSER TO THE COAST BUT OVERALL EXPECT MOST ACTIVITY TO MOVE
INTO WESTERN COUNTIES FROM JUST WEST OF CWA LATER IN THE DAY. NAM
SHOWS IMPULSE IN MID TO UPPER FLOW REACHING OUR W-NW COUNTIES
BETWEEN 5 AND 8 PM....WHICH COINCIDES NICELY WITH HRRR FORECAST
FOR CONVECTION TO MOVE OVER WESTERN COUNTIES BETWEEN THE SAME
TIME. MAIN SHORTWAVE ENERGY RIDES OFF THE MID ATLANTIC COAST THIS
AFTN WITH PIECE DROPPING S-SE THROUGH THE AREA THIS
EVENING...REACHING THE COAST SHORTLY BEFORE MIDNIGHT. STORMS
SHOULD TRACK SLOWLY E-SE REMAINING SCT ACROSS INLAND CWA THROUGH
AT LEAST MIDNIGHT. ONCE THE HEATING DIMINISHES THIS EVENING AND
WITH MORE STABLE ATMOSPHERE BEHIND SEA BREEZE EXPECT STORMS TO
DISSIPATE AS THEY MOVE TOWARD THE COAST. THEREFORE WILL KEEP MAIN
POPS INLAND WITH ISO POPS ALONG COAST INTO TONIGHT AS THIS
FEATURE MOVES THROUGH. WITH STEERING FLOW OUT OF THE W-NW JUST
UNDER 10 MPH...ANY STORMS THAT DEVELOP WILL TRACK TOWARD THE
COAST.
WARM AND HUMID SUMMERTIME AIR MASS WILL MAINTAIN TEMPS IN THE MID
70S TONIGHT.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...SHORTWAVE DROPPING SOUTH AROUND EAST SIDE OF
5H RIDGE EARLY THU WILL CREATE A WEAKNESS IN THE 5H RIDGE. THIS
SHOULD LEAD TO SOME CONVECTION DEVELOPING ALONG PIEDMONT TROUGH AND
SEA BREEZE. HOWEVER COVERAGE REMAINS SOMEWHAT OF A QUESTION. THERE
WILL BE PLENTY OF INSTABILITY PRESENT WITH MLCAPE BETWEEN 2K AND 3K
J/KG AND LOW LEVEL LAPSE RATES OVER 8C/KM. THE BIG ISSUE IS GOING TO
BE THE RELATIVE LACK OF DEEP MOISTURE. EXCEPT FOR A MOIST LAYER FROM
800 TO 600 MB THE AIR MASS IS ON THE DRY SIDE. LATEST GUIDANCE
SUGGEST THE INHERITED 30-40 POP MAY BE A LITTLE ON THE HIGHS SIDE
AND IN FACT MOS NUMBERS ACROSS THE FORECAST AREA HAVE BEEN TRENDING
DOWN. WILL TRIM BACK TO 30...OR LOW CHANCE FOR NOW.
FRI LOOKS VERY SIMILAR TO THU THOUGH THE 5H RIDGE DOES START TO
REASSERT ITSELF A LITTLE MORE. THIS RESULTS IN MORE MID LEVEL
SUBSIDENCE/CAPPING...FURTHER INCREASING DRY AIR ALOFT. SUBSIDENCE
WILL BE ENHANCED BY EXIT OF A WEAK SHORTWAVE TO THE SOUTH THU NIGHT
INTO FRI. INSTABILITY IS MORE OR LESS EQUAL TO THU BUT THE LESS
FAVORABLE ENVIRONMENT WOULD TEND TO SUGGEST LESS OF A CHANCE OF
DIURNAL CONVECTION. LATE IN THE PERIOD SOME OF THE GUIDANCE IS
MOVING THE REMAINS OF A WASHED OUT COLD FRONT INTO THE AREA WHICH
MAY PROVIDE A LITTLE MORE MOISTURE/LIFT...IF IT REACHES THE REGION.
MOST OF THE GUIDANCE IS NOT AS BULLISH AS THE NAM WITH THIS FEATURE
AND DISSIPATES IT BEFORE IT HAS ANY IMPACT ON THE REGION. WILL TRIM
POP BACK FOR FRI BUT HOLD ONTO CHANCE WORDING AT THIS POINT.
GIVEN THE AMOUNT OF INSTABILITY AND THE VERTICAL PROFILES EACH
DAY...INVERTED V...STRONGER STORMS EITHER DAY COULD RESULT IN
DAMAGING WIND. TEMPERATURES ABOVE CLIMO THROUGH THE PERIOD...MID TO
UPPER 90S AWAY FROM THE COAST AND MID TO UPPER 70S OVERNIGHT.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 3 AM WEDNESDAY...EASTWARD EXTENSION OF 5H RIDGE OVER THE
PLAINS WILL KEEP THE AREA ON THE DRY SIDE OVER THE WEEKEND.
COMBINATION OF SUBSIDENCE UNDER THE 5H RIDGE AND DEEP DRY AIR WILL
LIMIT COVERAGE OF CONVECTION EACH DAY. THE PRESENCE OF A PIEDMONT
TROUGH AND SEA BREEZE AND CAPE VALUES OVER 2K J/KG SAT/SUN WOULD
EXPECT TO SEE SOME ISOLATED CONVECTION EACH AFTERNOON...COVERED BY
INHERITED SLIGHT CHANCE.
PATTERN ALOFT EVOLVES MON AS LOBE OF POLAR VORTEX OVER EASTERN
CANADA STARTS TO EXPAND SOUTH...SUPPRESSING EASTERN EXTENSION OF
PLAINS RIDGE. NORTHERLY FLOW ALOFT IS REPLACED BY DEEP NORTHWEST
FLOW MON/TUE WITH THE 5H TROUGH AXIS LOCATED OFFSHORE. DEEP MOISTURE
ARRIVING EARLY NEXT WEEK...SOUTHWEST MONSOON MOISTURE TOPPING THE 5H
PLAINS RIDGE...COMBINED WITH DIURNAL INSTABILITY AND LIFT ALONG
PIEDMONT TROUGH AND SEA BREEZE WILL LEAD TO AN INCREASE IN SHOWERS
AND THUNDERSTORMS LATE IN THE PERIOD. INHERITED POP RANGE FROM 30 TO
40 MON/TUE. SEE NO REASON NOT TO GO SOLID 40 AT THIS POINT WITH
FURTHER INCREASES POSSIBLE. TEMPERATURES WILL BE ABOVE CLIMO THROUGH
THE PERIOD...THOUGH WITH HIGHS TRENDING DOWN MON/TUE UNDER
DECREASING HEIGHTS AND INCREASING STORM COVERAGE.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 18Z...STAGNANT SYNOPTIC PATTERN WILL CONTINUE...WITH A
PERSISTENT THERMAL TROUGH. LOW LEVEL LAPSE RATES ARE QUITE
STEEP...BUT A SUBSIDENCE INVERSION AROUND 650 MB MAY KEEP A CAP ON
ANY CONVECTION FOR A WHILE. A STRUNG OUT VORT MAX...WEAKLY EVIDENT
ON WATER VAPOR...WILL DROP SOUTHWARD INTO THE CAROLINAS LATE THIS
AFTERNOON. MOST OF THE ENERGY IS OFFSHORE. THE WRF HAS A RATHER
LARGE COMPLEX OF STORMS DROPPING SOUTHEAST INTO THE NORTHEAST
PORTION OF THE CWA THIS EVENING. LOW CONFIDENCE ON THIS SCENARIO
RIGHT NOW...BUT GIVEN THE CAPE AND THE SEA BREEZE BOUNDARY...ANY
LITTLE IMPULSE COULD KICK OFF SOME GOOD STORMS. SOUTHWEST FLOW WILL
CONTINUE THIS AFTERNOON THROUGH THE OVERNIGHT HOURS.
EXTENDED OUTLOOK...A CHANCE OF THUNDERSTORMS EACH DAY...MAINLY IN
THE AFTERNOON AND EVENING. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 130 PM WEDNESDAY...SOUTHWEST FLOW WILL CONTINUE AROUND
BERMUDA HIGH WITH WINDS AROUND 10 TO 15 KTS WITH HIGHER GUSTS
THROUGH EARLY EVENING. THE SEA WILL BE DOMINATED BY WIND-DRIVEN
S TO SW WAVES OF 2-4 FEET RUNNING IN 5-6 SECONDS INTERVALS...AND
WEAKER BUT LONGER PERIOD SE WAVES OF 1-2 FT EVERY 9-10 SECONDS.
SPIKE IN WINDS OVERNIGHT UP TO 20 KTS IN OUTER WATERS MAY CAUSE
ISOLATED 5 FTERS OUT TOWARD FRYING PAN SHOALS. ISOLATED TSTMS
WILL REMAIN POSSIBLE THROUGH TONIGHT AS AN UPPER LEVEL IMPULSE
MOVES SE ACROSS THE WATERS OVERNIGHT.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...TYPICALLY SUMMER PATTERN WITH PIEDMONT TROUGH
AND BERMUDA HIGH KEEPING FLOW OVER THE WATERS SOUTHEAST. FAIRLY LAX
GRADIENT THROUGH THE PERIOD WILL KEEP SPEEDS 10 TO 15 KT...WITH SOME
ENHANCEMENT NEAR SHORE AS SEA BREEZES DEVELOP. SEAS 3 TO 4 FT...A
COMBINATION OF DOMINANT SOUTHERLY WIND WAVE AND WEAK SOUTHEAST
SWELL.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 AM WEDNESDAY...WATERS REMAIN BETWEEN BERMUDA HIGH AND
DIURNALLY ENHANCED PIEDMONT TROUGH. WINDS 10 TO 15 KT SAT INCREASE
TO 15 TO 20 KT SUN IN RESPONSE TO TIGHTENING SURFACE GRADIENT. SEAS
3 TO 4 FT SAT BUILD TO 3 TO 5 FT SUN...A COMBINATION OF DOMINANT
SOUTHERLY WIND WAVE AND WEAK SOUTHEAST SWELL.
&&
.TIDES/COASTAL FLOODING...
AS OF 3 AM WEDNESDAY...THE RECENT PASSING OF THE OFFICIAL FULL
MOON WILL KEEP H2O LEVELS ELEVATED THE NEXT COUPLE DAYS...BUT
SIGNIFICANT FLOODING IN EVEN PRONE AREAS LOOKS TO REMAIN MINIMAL.
FIREWORKS SHOW AT THE BATTLESHIP WILL DRAW CROWDS...BUT RIGHT NOW
AT WORSE WE COULD SEE SHALLOW ENCROACHMENT OF WATER ON A FEW ROADS
DOWNTOWN AT WORSE. NO SIGNIFICANT HAZARDS ANTICIPATED WITH ASTRO-
TIDES TODAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RGZ
SHORT TERM...III
LONG TERM...III
AVIATION...DL/RGZ
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1116 AM CDT WED JUL 4 2012
.DISCUSSION...
ALL KINDS OF HEADACHES FOR THE MORNING UPDATE WITH ONGOING SEVERE
WEATHER AND WHAT TO DO ABOUT THE HEAT HEADLINES. SFC LOW WAS
CENTERED NEAR JAMESTOWN...WITH PLENTY OF WARM MOIST AIR IN THE
SOUTHERLY WINDS ON THE FRONT SIDE OF THE LOW. THIS HAS BEEN
HELPING TO FEED THE THUNDERSTORMS OVER THE NORTHERN CWA DURING THE
MORNING HOURS. THE STORMS STARTED OUT NEAR THE INTERNATIONAL
BORDER BUT HAVE BEEN DEVELOPING SOUTHWARD ALONG A WEAK COLD
FRONTAL BOUNDARY INTO THE CENTRAL CWA DESPITE 700MB TEMPS INTO THE
MID TEENS C. EXPANDED HIGHER POPS FURTHER SOUTH AND INCLUDED
SEVERE MENTION IN THE NORTHERN CWA WHERE WE HAVE THE WATCH. SO FAR
THE MORE SOUTHERN ACTIVITY HAS BEEN BELOW SEVERE...BUT WILL KEEP
AN EYE ON THEM. PREVIOUS MODEL RUNS HAVE SHOWN REDEVELOPMENT LATER
THIS AFTERNOON AND THE HRRR CONTINUES TO SHOW THIS. WILL CONTINUE
TO KEEP THE BEST CHANCES IN THE NORTHEASTERN COUNTIES WITH
ISOLATED ACTIVITY FURTHER SOUTH.
THE OTHER QUESTION IS WHAT TO DO WITH THE HEAT HEADLINES. BY ALL
APPEARANCES A WEAK COND FRONT HAS ADVANCED TO A ROSEAU TO GRAND
FORKS TO CARRINGTON LINE...ALTHOUGH SOME OF THE OBS MAY BE
AFFECTED BY THUNDERSTORM OUTFLOW RATHER THAN SYNOPTIC SCALE
FEATURES. TEMPS HAVE DROPPED OFF IN THE NORTHWESTERN AND NORTH
CENTRAL CWA...SO LOWERED HIGHS A BIT INTO THE MID 80S IN THAT
AREA. THIS WILL KNOCK DOWN HEAT INDEX VALUES BELOW CRITERIA IN
THAT AREA. HOWEVER...THE NAM CONTINUES TO SHOW SOME POOLING OF
UPPER 70S DEW POINTS BEHIND THE FRONT ON THE NORTH SIDE OF THE LOW.
THINK THIS MAY BE OVERDONE...BUT AM RELUCTANT TO PULL THE ADVISORY
IN THE NORTH IN CASE TEMPS THIS AFTERNOON SPIKE UP. WILL LEAVE
HEADLINES AS THEY ARE FOR NOW AND RE-EVALUATE THIS AFTERNOON AND
START PULLING COUNTIES THEN.
&&
.AVIATION...
KGFK AND KTVF HAVE BEEN AFFECTED BY TSRA...BUT ALL OTHER TAF SITES
SHOULD BE VFR. ANY MVFR CONDITIONS WILL BE SHORT LIVED AND BROUGHT
ON BY CONVECTION. WINDS WILL BE SHIFTING TO THE EAST IN THE
NORTHERN SITES THIS MORNING...THEN TO THE NORTHWEST BY AFTERNOON
ACROSS THE ENTIRE FORECAST AREA. WINDS WILL GO LIGHT AND VARIABLE
BY THIS EVENING.
&&
.PREV DISCUSSION... /ISSUED 402 AM CDT WED JUL 4 2012/
SHORT TERM (TODAY-FRIDAY NIGHT)...MAIN CONCERNS WILL BE HEAT AND
CONVECTIVE/SEVERE CHANCES TODAY. 00Z MODELS IN DECENT AGREEMENT
AND WILL USE A BLEND FOR DETAILS.
TODAY...STRONG COLD FRONT/DRY LINE ACROSS EASTERN MONTANA/WESTERN
NORTH DAKOTA WILL PROPAGATE EASTWARD THROUGH THE DAY. THIS FEATURE
SHOULD BE NEAR THE WESTERN FA AT 18Z AND THROUGH THE FA BY 06Z. A
VERY HOT AND HUMID AIRMASS WILL BE IN PLACE AHEAD OF THIS FEATURE.
WILL NEED TO ISSUE A HEAT ADVISORY ACROSS ALL BUT THE DVL BASIN
WITH HEAT INDICES 100F-110F EXPECTED. REGARDING CONVECTIVE
CHANCES....A VERY UNSTABLE AIRMASS WILL ALSO BE IN PLACE AHEAD OF
THIS FEATURE...WITH MLCAPE VALUES UP TO 4000 J/KG. VERY WARM MID-
LEVEL TEMPS WILL ALSO BUILD INTO THE REGION AND PROVIDE STRONG
CAPPING. DEEP LAYER SHEAR UP TO 50 KNOTS WILL BE STRONGEST ACROSS
THE NORTHERN FA. MODEL GUIDANCE DOES NOT PROVIDE MUCH HELP FOR
DETAILS REGARDING WHAT WILL OCCUR TODAY. 3-KM HRRR AND 4-KM WRF
MODELS ARE CURRENTLY TOO FAR SOUTH WITH CURRENT ACTIVITY NORTH OF
THE INTERNATIONAL BORDER...BRINGING THE COMPLEX ACROSS THE
NORTHERN HALF OF THE FA THIS MORNING. NAM AND ECMWF SEEM TO BE
HANDLING THE CURRENT SITUATION BEST. GIVEN BUILDING WARM MID-LEVEL
TEMPS...THIS COMPLEX SHOULD REMAIN TO THE NORTH (BUT WILL BE
CLOSE) AND WEAKEN AS LOW-LEVEL JET WEAKENS. SITUATION IS MORE
UNCLEAR FOR LATE THIS MORNING INTO THE AFTERNOON HOURS...LIKELY
DEPENDING ON WHAT OCCURS EARLY THIS MORNING. GIVEN MODEL
GUIDANCE...BEST THUNDER CHANCES SHOULD BE ACROSS EXTREME NORTHEAST
NORTH DAKOTA INTO WEST CENTRAL MINNESOTA...WHERE MID-LEVEL TEMPS
ARE COOLEST AND MODELS INDICATE MLCIN NEARLY GONE BY 18-21Z. THIS
SEEMS POSSIBLE GIVEN EXPECTED DEW POINT VALUES MID-UPPER 70S. SPC
ONLY HAS A 5% PROB FOR SEVERE STORMS...BUT WILL INSERT SEVERE AND
HEAVY RAIN INTO THE FORECAST ACROSS THIS AREA GIVEN EXTREME
INSTABILITY AND PWATS NEAR 2.0 INCHES. MAIN THREAT LIKELY LARGE
HAIL AND BOW-ECHO STRONG STRAIT LINE WINDS. KEPT ISOLD THUNDER
ELSEWHERE...BUT THE REMAINDER OF THE FA COULD REMAIN DRY TODAY.
THUR-FRI...VERY DRY AIRMASS MOVES INTO THE REGION FOR THURSDAY
ALONG WITH RIDGING. BAROCLINIC ZONE/MID-LEVEL BOUNDARY MOVES BACK
NORTH THUR NIGHT AND REMAINS INTO FRIDAY NIGHT. THIS WILL LIKELY
PROVIDE SHOWERS AND THUNDERSTORMS TO THE SOUTHERN FA. INSTABILITY
IS WEAK...BUT PWATS NEAR 1.75 INCHES SHOULD LEAD TO LONG DURATION
RAINFALL UP TO 2 INCHES. MAIN CHALLENGE WILL BE NORTHERN EXTENT OF
RAINFALL.
LONG TERM (SATURDAY-TUESDAY)...MODELS IN FAIR AGREEMENT IN THE
EXTENDED TIME FRAME. 500MB PATTERN CONTINUES TO SUGGEST NW FLOW
ACROSS THE CWFA WITH STRONG RIDGING ACROSS THE MOUNTAIN WEST AND
TROUGH DEVELOPING OVER EASTERN CANADA. AS A RESULT MORE SEASONAL
TEMPS AND DRY WEATHER WITH NO PCPN EXPECTED AFTER THE CHC IN THE
SOUTH ON SATURDAY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR NDZ008-016-027-029-
030-038-039-049-052-053.
MN...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR MNZ001>009-013>017-
022>024-027>032-040.
&&
$$
JR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
402 AM CDT WED JUL 4 2012
.SHORT TERM (TODAY-FRIDAY NIGHT)...MAIN CONCERNS WILL BE HEAT AND
CONVECTIVE/SEVERE CHANCES TODAY. 00Z MODELS IN DECENT AGREEMENT
AND WILL USE A BLEND FOR DETAILS.
TODAY...STRONG COLD FRONT/DRY LINE ACROSS EASTERN MONTANA/WESTERN
NORTH DAKOTA WILL PROPAGATE EASTWARD THROUGH THE DAY. THIS FEATURE
SHOULD BE NEAR THE WESTERN FA AT 18Z AND THROUGH THE FA BY 06Z. A
VERY HOT AND HUMID AIRMASS WILL BE IN PLACE AHEAD OF THIS FEATURE.
WILL NEED TO ISSUE A HEAT ADVISORY ACROSS ALL BUT THE DVL BASIN
WITH HEAT INDICES 100F-110F EXPECTED. REGARDING CONVECTIVE
CHANCES....A VERY UNSTABLE AIRMASS WILL ALSO BE IN PLACE AHEAD OF
THIS FEATURE...WITH MLCAPE VALUES UP TO 4000 J/KG. VERY WARM MID-
LEVEL TEMPS WILL ALSO BUILD INTO THE REGION AND PROVIDE STRONG
CAPPING. DEEP LAYER SHEAR UP TO 50 KNOTS WILL BE STRONGEST ACROSS
THE NORTHERN FA. MODEL GUIDANCE DOES NOT PROVIDE MUCH HELP FOR
DETAILS REGARDING WHAT WILL OCCUR TODAY. 3-KM HRRR AND 4-KM WRF
MODELS ARE CURRENTLY TOO FAR SOUTH WITH CURRENT ACTIVITY NORTH OF
THE INTERNATIONAL BORDER...BRINGING THE COMPLEX ACROSS THE
NORTHERN HALF OF THE FA THIS MORNING. NAM AND ECMWF SEEM TO BE
HANDLING THE CURRENT SITUATION BEST. GIVEN BUILDING WARM MID-LEVEL
TEMPS...THIS COMPLEX SHOULD REMAIN TO THE NORTH (BUT WILL BE
CLOSE) AND WEAKEN AS LOW-LEVEL JET WEAKENS. SITUATION IS MORE
UNCLEAR FOR LATE THIS MORNING INTO THE AFTERNOON HOURS...LIKELY
DEPENDING ON WHAT OCCURS EARLY THIS MORNING. GIVEN MODEL
GUIDANCE...BEST THUNDER CHANCES SHOULD BE ACROSS EXTREME NORTHEAST
NORTH DAKOTA INTO WEST CENTRAL MINNESOTA...WHERE MID-LEVEL TEMPS
ARE COOLEST AND MODELS INDICATE MLCIN NEARLY GONE BY 18-21Z. THIS
SEEMS POSSIBLE GIVEN EXPECTED DEW POINT VALUES MID-UPPER 70S. SPC
ONLY HAS A 5% PROB FOR SEVERE STORMS...BUT WILL INSERT SEVERE AND
HEAVY RAIN INTO THE FORECAST ACROSS THIS AREA GIVEN EXTREME
INSTABILITY AND PWATS NEAR 2.0 INCHES. MAIN THREAT LIKELY LARGE
HAIL AND BOW-ECHO STRONG STRAIT LINE WINDS. KEPT ISOLD THUNDER
ELSEWHERE...BUT THE REMAINDER OF THE FA COULD REMAIN DRY TODAY.
THUR-FRI...VERY DRY AIRMASS MOVES INTO THE REGION FOR THURSDAY
ALONG WITH RIDGING. BAROCLINIC ZONE/MID-LEVEL BOUNDARY MOVES BACK
NORTH THUR NIGHT AND REMAINS INTO FRIDAY NIGHT. THIS WILL LIKELY
PROVIDE SHOWERS AND THUNDERSTORMS TO THE SOUTHERN FA. INSTABILITY
IS WEAK...BUT PWATS NEAR 1.75 INCHES SHOULD LEAD TO LONG DURATION
RAINFALL UP TO 2 INCHES. MAIN CHALLENGE WILL BE NORTHERN EXTENT OF
RAINFALL.
.LONG TERM (SATURDAY-TUESDAY)...MODELS IN FAIR AGREEMENT IN THE
EXTENDED TIME FRAME. 500MB PATTERN CONTINUES TO SUGGEST NW FLOW
ACROSS THE CWFA WITH STRONG RIDGING ACROSS THE MOUNTAIN WEST AND
TROUGH DEVELOPING OVER EASTERN CANADA. AS A RESULT MORE SEASONAL
TEMPS AND DRY WEATHER WITH NO PCPN EXPECTED AFTER THE CHC IN THE
SOUTH ON SATURDAY.
&&
.AVIATION...MAIN CONCERN FOR TODAY WILL BE THUNDERSTORM CHANCES AS
CIGS SHOULD REMAIN VFR. HIGHEST PROBABILITY FOR STORMS WILL BE
NEAR THE INTERNATIONAL BORDER INTO NORTHWEST MINNESOTA...AFFECTING
KTVF AND KBJI.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...HEAT ADVISORY FROM 11 AM THIS MORNING TO 7 PM CDT THIS EVENING
FOR NDZ008-016-027-029-030-038-039-049-052-053.
MN...HEAT ADVISORY FROM 11 AM THIS MORNING TO 7 PM CDT THIS EVENING
FOR MNZ001>009-013>017-022>024-027>032-040.
&&
$$
TG/JK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
339 AM CDT WED JUL 4 2012
.SHORT TERM...TODAY THROUGH THURSDAY...
COLD FRONT EXPECTED BE NEAR/ALONG A MINOT TO BISMARCK LINE AND INTO THE
JAMES RIVER VALLEY BY 18Z. EXPECTING ANY PRECIPITATION TO MAINLY BE
CONFINED IN THE NORTHEAST ZONES WITH A DRY FROPA ELSEWHERE.
HOWEVER WILL METWATCH CLOSELY AS THE HRRR HAS BEEN CONSISTENTLY
SHOWING SOME SOUTHWARD EXPANSION IN THE PRECIPITATION THROUGH THE
EARLY MORNING. OTHERWISE EXPECT BREEZY CONDITIONS BEHIND THE
FRONT WITH DRIER AIR/LOWER DEW POINTS ARRIVING DURING THE DAY. STILL
WARM TODAY WITH HIGHS BETWEEN 80F AND 90F. COOLER AND DRIER AIR
SETTLES OVER WESTERN AND CENTRAL NORTH DAKOTA TONIGHT WITH LOWS
BETWEEN 50F AND 60F. THE NEXT SHORTWAVE IS SCHEDULED TO APPROACH
OUR SOUTHERN ZONES THURSDAY WITH A SLIGHT CHC OF SHOWERS/THUNDERSTORMS
IN THE AFTERNOON. MORE SUBSTANTIAL PRECIPITATION SLATED FOR THURSDAY
NIGHT INTO FRIDAY.
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...
NEXT SHORTWAVE TROUGH WITH AN ASSOCIATED SURFACE LOW WILL MOVE
ACROSS SOUTH DAKOTA THURSDAY NIGHT THROUGH FRIDAY NIGHT. IT
APPEARS THAT THE MODELS ARE COMING INTO DECENT AGREEMENT WITH AN
MCS EVENT...STARTING IN WYOMING/WESTERN SOUTH DAKOTA THURSDAY
NIGHT AND ROTATING NORTHEAST INTO SOUTHERN NORTH DAKOTA. THE
POTENTIAL OF WIDESPREAD 1 INCH RAINFALL AMOUNTS ALONG AND SOUTH
INTERSTATE 94 THURSDAY NIGHT THROUGH FRIDAY AFTERNOON LOOK
REASONABLE AND HAVE MADE LITTLE CHANGES TO THE HPC QPF AMOUNTS.
POSSIBLE TOTAL RAINFALL AMOUNTS NEAR THE BORDER COULD BE AROUND
1. 5 INCHES. THEREAFTER...THE UPPER LEVEL FLOW GRADUALLY BECOMES
NORTHWEST THROUGH EARLY NEXT WEEK AS THE CENTRAL PLAINS RIDGE
SHIFTS WEST. THIS WILL STILL ALLOW FOR RIDGE TOPPERS TO MOVE
THROUGH NORTH DAKOTA BUT LOW LEVEL MOISTURE WILL BE CONSIDERABLE
LESS AND AREAL COVERAGE OF PRECIPITATION SHOULD FOLLOW.
&&
.AVIATION...VFR CEILINGS/VISIBILITIES EXPECTED NEXT 24HR. POSSIBLE
LOW VFR CEILINGS AT KISN AND KMOT THROUGH 12Z WEDNESDAY. AN
ISOLATED SHOWER OR THUNDERSTORM CANNOT BE RULED OUT AT KJMS
THROUGH 00Z THURSDAY. SKIES WILL CLEAR WEDNESDAY NIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM/LONG TERM...KS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1248 AM CDT WED JUL 4 2012
.DISCUSSION...HAVE COORDINATED WITH SPC AND WE HAVE COLLECTIVELY
EXTENDED THE SEVERE THUNDERSTORM WATCH THROUGH 04/08Z. CONCERN IS
THE LATEST HRRR CONTINUES TO DEVELOP THIS AREA FURTHER EAST
OVERNIGHT AND ALSO SOUTH. JUST NOT SURE EXACTLY HOW THINGS WILL
COME TOGETHER. WE HAVE THE APPROPRIATE COUNTIES COVERED FOR THE
EASTWARD TREND OVERNIGHT...BUT IF A SOUTHWARD EXPANSION BEGINS WE
WILL NEED TO MAKE QUICK ADJUSTMENTS.
ALSO...WE ARE CLOSELY MONITORING HYDRO CONCERNS IN THE NORTHWEST
AS REPETITIVE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS OVER
NORTHEAST MONTANA INTO NORTHWEST NORTH DAKOTA CONTINUE.
LATEST PRODUCTS WILL BE OUT SHORTLY.
&&
.AVIATION...VFR NEXT 24HR. WILL NEED TO MONITOR KISN/KMOT FOR
SHOWERS AND THUNDERSTORMS THROUGH 12Z WEDNESDAY. RIGHT NOW WE HAVE
DRY WEATHER IN THE 06Z TAFS...AND WILL CONTINUE TO MONITOR THESE
TRENDS. REST OF THE AERODROMES ARE FORECAST TO BE DRY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION..KS
AVIATION...RK/KS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
620 PM EDT WED JUL 4 2012
.SYNOPSIS...
A STATIONARY FRONT LIES JUST NORTH OF THE AREA AND WILL EVENTUALLY
BECOME A BACK DOOR COLD FRONT THURSDAY MORNING. THE FRONT WILL
DISSIPATE AS WEAK HIGH PRESSURE BUILDS SOUTH OVER THE REGION BY
FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
CONVECTION NORTH OF LERI HAVING A HARD TIME MOVING FURTHER SOUTH
INTO THE LAKE...APPARENTLY DUE TO LAKE STABILIZATION OCCURRING. WEAK
PIECE OF UPPER ENERGY FURTHER UPSTREAM SHOULD DROP TOWARD LERI LATE
THIS EVENING WHICH SHOULD GIVE MORE SUPPORT TO GET A BETTER
SOUTHWARD PUSH OF THE CONVECTION. ADJUSTED GRIDS TO BACK POPS DOWN
FOR THE TIME BEING EARLY THIS EVENING.
WILL LET THE HEAT ADVISORY AND HEAT WARNINGS HEADLINES CONTINUE
THROUGH 9 PM.
THE OTHER QUESTION IS THE COMPLEX OVER MINNESOTA...WILL IT HOLD
TOGETHER AND WHERE WILL IT END UP. IF IT KEEPS TOGETHER AND SOME OF
THE MODELS DON`T THINK IT WILL THE STORMS MAY END UP OVER THE
WESTERN PORTION OF THE FORECAST AREA TOWARD DAYBREAK.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY NIGHT/...
THE COMPLEX OVER MINNESOTA IS THE BIG QUESTION. IF IT GETS INTO THE
AREA FOR THURSDAY MORNING WITH THE CLOUDS THAT MAY KEEP TEMPERATURES
DOWN ENOUGH THAT MAY KEEP NORTHWEST OHIO AWAY FROM HEAT ADVISORY
AND OR EXCESSIVE HEAT WARNING CRITERIA. BECAUSE OF THAT...WILL
NOT ISSUE AN ADVISORY FOR THURSDAY. THE NORTHEAST AREAS MAY NOT
MEET THE CRITERIA WITH A LITTLE LOWER DEW POINTS TRYING TO MOVE IN
WITH THE BOUNDARY TRYING TO MOVE IN FROM THE EAST.
THE BEST CHANCE OF AFTERNOON THUNDERSTORMS THURSDAY WILL BE OVER
NORTHWEST OHIO. THE THREAT ON FRIDAY IS IFFY BUT THE CHANCE GETS
BETTER SATURDAY AND SUNDAY AS A FRONTAL SYSTEM MOVES IN. THE ECMWF
IS NOT AS PESSIMISTIC AS THE GFS AND OTHER MODELS...SO CHANCE POPS
SEEM GOOD.
WENT WARM FOR THE LOWS AND CLOSE TO THE MOS NAM FOR HIGHS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
A GENERALLY FAIR...COOLER AND SEASONABLE PERIOD IS EXPECTED. A
SHORT WAVE WILL BE EXITING THE REGION ON MONDAY SO THERE IS A
LINGERING CHANCE OF SHOWERS AND THUNDERSTORMS EARLY MONDAY AND THEN
DRIER AND COOLER CONDITIONS WILL PREVAIL. THE ECMWF AND THE GFS ARE
IN GENERAL AGREEMENT WITH THE EXCEPTION THAT THE GFS IS FASTER IN
EXITING THE SHORTWAVE ON MONDAY. WILL LEAVE A SLIGHT CHANCE OF PCPN
ON MONDAY.
850 MB TEMPERATURES WILL COOL TO NEAR 14C WHICH WILL BE MUCH COOLER
THAN RECENTLY.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
TIMING AND COVERAGE OF CONVECTIVE DEVELOPMENT THIS AFTERNOON AND
OVERNIGHT IS DIFFICULT TO DISCERN. THERE IS EXTREME INSTABILITY OVER
THE REGION WITH CAPE NEAR 4500 J/KG WITH A SINGLE CONVECTIVE CELL
DEVELOPING NW OF GKJ. HOURLY MODEL RUNS OF HRRR HAVE BEEN QUITE
VARIABLE IN STORM DEVELOPMENT. WITH COVERAGE UNCERTAIN WILL LEAVE
MENTION OF STORMS OUT OF THE TAFS FOR NOW. THE BEST CHANCE MAY BE IN
KYNG AREA THIS AFTERNOON. GENERALLY VFR CONDITIONS ARE EXPECTED INTO
THE NIGHT WITH PERHAPS MVFR WITH HAZE AND LIGHT FOG FROM 08Z- 12Z
MAINLY INLAND FROM THE LAKE.
.OUTLOOK...NON VFR CONDITIONS POSSIBLE IN SHOWERS/THUNDERSTORMS
WEDNESDAY NIGHT AND AGAIN ON SATURDAY.
&&
.MARINE...
LIGHT TO MODERATE SOUTHWEST FLOW EXPECTED TO CONTINUE TONIGHT AS LOW
OVER MN DEEPENS INTERACTS WITH HIGH OVER THE SOUTHEAST U.S. TO
PRODUCE WINDS AROUND 10 KT WITH GUSTS TO 15 KT. WAVES WILL BE AROUND
2 FT GIVE OR TAKE A FOOT INTO THURSDAY.
THURSDAY WINDS WILL SHIFT TO THE NORTH AS HIGH PRES OVER NORTH
CENTRAL CANADA SINKS SOUTH. THE GRADIENT BETWEEN THIS HIGH PRESSURE
AND THE ONE OVER THE SOUTHEAST IS WEAK AS THE ONE TO THE SOUTH
BREAKS DOWN. THIS HIGH WILL SLIDE EAST FRIDAY AND WINDS WILL ONCE
AGAIN SWITCH AROUND TO THE SOUTHWEST BY FRIDAY. A COLD FRONT WILL
SINK SOUTH INTO THE AREA SATURDAY WITH WINDS SHIFTING TO THE NORTH.
WINDS AND SEAS WILL INCREASE AS THE FRONT SINKS SOUTH...WITH N WINDS
APPROACHING OR EXCEEDING 15 KT. SEAS LOOK TO BUILD TO 2 TO 3 FEET.
NO HEADLINES EXPECTED THROUGH THE FORECAST PERIOD. TEMPS WILL BE
WARM ENOUGH EACH AFTERNOON TO SUPPORT A LAKE BREEZE WHICH CAN
LOCALLY SHIFT WINDS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR OHZ007>014-
018>023-027>033-036>038-047.
EXCESSIVE HEAT WARNING UNTIL 9 PM EDT THIS EVENING FOR OHZ003-
006-017.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA/ADAMS
SHORT TERM...KIELTYKA
LONG TERM...REL
AVIATION...REL
MARINE...JAMISON
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
436 PM EDT WED JUL 4 2012
.SYNOPSIS...
UPPER LEVEL HIGH PRESSURE WILL EXPAND ACROSS THE REGION THROUGH
THE REST OF THE WEEK KEEPING HOT CONDITIONS IN PLACE. THE HEAT
WAVE WILL BREAK EARLY NEXT WEEK AFTER A COLD FRONT MOVES THROUGH
DURING THE WEEKEND...ALLOWING COOLER HIGH PRESSURE TO BUILD IN.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
WEAK CONVERGENCE ACROSS THE REGION THIS AFTERNOON MAY ALLOW FOR
SOME ISOLATED CONVECTION. A DISTURBANCE HAS RESULTED IN STORMS
DEVELOPING IN SOUTHWEST ONTARIO. AS THAT DROPS SOUTHEAST THERE
COULD BE ADDITIONAL DEVELOPMENT BACK WEST OF CURRENT ACTIVITY.
AND IF THAT OCCURS THEN SOME STORMS COULD GRAZE THE NORTHEAST PART
OF THE FORECAST AREA LATE THIS AFTERNOON OR EARLY THIS EVENING.
OTHERWISE LIGHT WESTERLY FLOW WILL PERSIST OVERNIGHT. HAVE LEANED
TOWARDS WARMER GUIDANCE FOR LOWS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
ANOTHER DISTURBANCE COMING OVER THE TOP OF AN EXPANDING RIDGE WILL
MOVE SOUTHEAST ACROSS THE UPPER OHIO VALLEY TOMORROW. THIS WILL
BRING ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS PRIMARILY FOR
THE EASTERN ZONES DURING THE AFTERNOON AND EVENING. DO NOT EXPECT
STORMS TO BE EXPANSIVE ENOUGH TO HAVE ANY MORE THAN A TEMPORARY
EFFECT ON TEMPERATURES.
GUIDANCE SUGGESTS THAT READINGS WILL BE SLIGHTLY WARMER THAN
TODAYS HIGHS. WITH LITTLE VARIATION IN DEW POINTS...THESE HIGHER
TEMPERATURES SHOULD PUSH MOST LOCATIONS INTO HEAT WARNING
CRITERION /HEAT INDEX 105 OR GREATER/. IN ADDITION THIS WILL BE A
PROLONGED PERIOD OF HIGH HEAT INDICES. SO EVEN IF SOME PLACES DO
NOT MEET THE THRESHOLD...THE CUMULATIVE EFFECTS OF THE HEAT WILL
TAKE A TOLL. THUS THE EXCESSIVE HEAT WARNING WAS EXPANDED TO ALL
COUNTIES THROUGH SATURDAY. CONTINUED TO FAVOR WARMER MOS FOR
LOWS.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
HOT AND HUMID CONDITIONS WILL START OUT THE LONG TERM TIME FRAME
AND WILL CONTINUE ACROSS THE FA INTO SATURDAY. TEMPERATURES ON
FRIDAY AND SATURDAY WILL BE IN THE UPPER 90S TO AROUND 100 WITH
HEAT INDEX VALUES AROUND 105 DEGREES. DUE TO THIS THE ENTIRE AREA
HAS BEEN UPGRADED TO AN EXCESSIVE HEAT WARNING FOR FRIDAY AND
SATURDAY. WITH RIDGE IN PLACE OVER THE AREA THE FA WILL STAY DRY
ON FRIDAY AND DURING MOST OF THE DAY ON SATURDAY. THERE IS SOME
DISCREPANCY BETWEEN THE MODELS ON WHEN PRECIPITATION WILL OCCUR
AFTER THIS POINT. THE GFS IS A LOT QUICKER WITH THE FRONTAL
BOUNDARY AND THE PRECIPITATION AND BEGINS TO BRING PRECIPITATION
INTO THE AREA SATURDAY NIGHT. THE ECMWF IS SLOWER WITH THE
PRECIPITATION AND BRINGS THE BEST CHANCE OF PRECIPITATION INTO THE
AREA SUNDAY NIGHT. WENT CLOSER TO THE ECMWF SOLUTION AND HAVE THE
GREATEST PRECIPITATION CHANCES IN THE FORECAST DURING THE
OVERNIGHT HOURS SUNDAY NIGHT INTO MONDAY MORNING. PRECIPITATION
WILL THEN LINGER ACROSS SOUTHERN PORTIONS OF THE FA MAINLY IN
NORTHERN KENTUCKY MONDAY NIGHT INTO TUESDAY BEFORE COMPLETELY
EXITING THE AREA. AFTER SATURDAY THERE WILL BE A GENERAL DECREASE
IN TEMPERATURES FOR THE REST OF THE LONG TERM TIME FRAME.
TEMPERATURES BY MONDAY AND TUESDAY WILL BE IN THE 80S ACROSS THE
ENTIRE FA.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
CU FIELD HAS FILLED IN NICELY ACROSS THE AREA EARLY THIS AFTERNOON
AS THE AIRMASS CONTINUES TO DESTABILIZE. THE CU LOOKS A LITTLE
BETTER DEFINED ACROSS OUR NORTH ON THE VISIBLE SATELLITE AND THIS
IS WHERE THE LAST COUPLE RUNS OF THE HRRR HAVE TRIED TO GENERATE
SOME ISOLATED TO SCATTERED CONVECTION BY MID AFTERNOON. THE 12Z
NAM IS ALSO SHOWING THE POSSIBILITY OF SOME CONVECTION ACROSS AT
LEAST CENTRAL OHIO LATER THIS AFTERNOON. WOULD THEREFORE THINK
THAT KCMH/KLCK WILL WOULD HAVE THE BEST CHANCE OF SEEING ANY
DEVELOPMENT AS WE HEAD THROUGH THE AFTERNOON HOURS INTO EARLY
EVENING. SOME UNCERTAINTY STILL EXISTS FOR ANY CONVECTION
OVERNIGHT SO WILL LEAN TO TH DRIER SIDE AND HOLD OFF ON INCLUDING
ANYTHING IN THE TAFS ATTM.
OUTLOOK...THUNDERSTORMS POSSIBLE SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...EXCESSIVE HEAT WARNING UNTIL 8 PM EDT SATURDAY FOR OHZ026-034-
035-042>046-051>056-060>065-070>074-077>082-088.
KY...EXCESSIVE HEAT WARNING UNTIL 8 PM EDT SATURDAY FOR KYZ089>100.
IN...EXCESSIVE HEAT WARNING UNTIL 8 PM EDT SATURDAY FOR INZ050-058-
059-066-073>075-080.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...NOVAK
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
345 PM EDT WED JUL 4 2012
.SYNOPSIS...
A STATIONARY FRONT LIES JUST NORTH OF THE AREA AND WILL EVENTUALLY
BECOME A BACK DOOR COLD FRONT THURSDAY MORNING. THE FRONT WILL
DISSIPATE AS WEAK HIGH PRESSURE BUILDS SOUTH OVER THE REGION BY
FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
HOW MUCH THUNDERSTORM ACTIVITY WILL DEVELOP. THE CUMULUS DOESN`T
LOOK THAT GREAT BUT THE AIRMASS IS VERY UNSTABLE. STILL SOME
QUESTION AS TO WHERE THE ACTIVITY WILL DEVELOP. AT THIS TIME BASED
ON THE HRRR AND SREF...THINKING THE BEST CHANCE WILL BE THROUGH
MIDNIGHT AND COULD BE ANYWHERE.
WILL LET THE HEAT ADVISORY AND HEAT WARNINGS HEADLINES CONTINUE
THROUGH 9 PM.
THE OTHER QUESTION IS THE COMPLEX OVER MINNESOTA...WILL IT HOLD
TOGETHER AND WHERE WILL IT END UP. IF IT KEEPS TOGETHER AND SOME OF
THE MODELS DON`T THINK IT WILL THE STORMS MAY END UP OVER THE
WESTERN PORTION OF THE FORECAST AREA TOWARD DAYBREAK.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY NIGHT/...
THE COMPLEX OVER MINNESOTA IS THE BIG QUESTION. IF IT GETS INTO THE
AREA FOR THURSDAY MORNING WITH THE CLOUDS THAT MAY KEEP TEMPERATURES
DOWN ENOUGH THAT MAY KEEP NORTHWEST OHIO AWAY FROM HEAT ADVISORY
AND OR EXCESSIVE HEAT WARNING CRITERIA. BECAUSE OF THAT...WILL
NOT ISSUE AN ADVISORY FOR THURSDAY. THE NORTHEAST AREAS MAY NOT
MEET THE CRITERIA WITH A LITTLE LOWER DEW POINTS TRYING TO MOVE IN
WITH THE BOUNDARY TRYING TO MOVE IN FROM THE EAST.
THE BEST CHANCE OF AFTERNOON THUNDERSTORMS THURSDAY WILL BE OVER
NORTHWEST OHIO. THE THREAT ON FRIDAY IS IFFY BUT THE CHANCE GETS
BETTER SATURDAY AND SUNDAY AS A FRONTAL SYSTEM MOVES IN. THE ECMWF
IS NOT AS PESSIMISTIC AS THE GFS AND OTHER MODELS...SO CHANCE POPS
SEEM GOOD.
WENT WARM FOR THE LOWS AND CLOSE TO THE MOS NAM FOR HIGHS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
A GENERALLY FAIR...COOLER AND SEASONABLE PERIOD IS EXPECTED. A
SHORT WAVE WILL BE EXITING THE REGION ON MONDAY SO THERE IS A
LINGERING CHANCE OF SHOWERS AND THUNDERSTORMS EARLY MONDAY AND THEN
DRIER AND COOLER CONDITIONS WILL PREVAIL. THE ECMWF AND THE GFS ARE
IN GENERAL AGREEMENT WITH THE EXCEPTION THAT THE GFS IS FASTER IN
EXITING THE SHORTWAVE ON MONDAY. WILL LEAVE A SLIGHT CHANCE OF PCPN
ON MONDAY.
850 MB TEMPERATURES WILL COOL TO NEAR 14C WHICH WILL BE MUCH COOLER
THAN RECENTLY.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
TIMING AND COVERAGE OF CONVECTIVE DEVELOPMENT THIS AFTERNOON AND OVERNIGHT IS
DIFFICULT TO DISCERN. THERE IS EXTREME INSTABILITY OVER THE REGION
WITH CAPE NEAR 4500 J/KG WITH A SINGLE CONVECTIVE CELL DEVELOPING
NW OF GKJ. HOURLY MODEL RUNS OF HRRR HAVE BEEN QUITE VARIABLE IN
STORM DEVELOPMENT. WITH COVERAGE UNCERTAIN WILL LEAVE MENTION OF
STORMS OUT OF THE TAFS FOR NOW. THE BEST CHANCE MAY BE IN KYNG
AREA THIS AFTERNOON. GENERALLY VFR CONDITIONS ARE EXPECTED INTO
THE NIGHT WITH PERHAPS MVFR WITH HAZE AND LIGHT FOG FROM 08Z- 12Z
MAINLY INLAND FROM THE LAKE.
.OUTLOOK...NON VFR CONDITIONS POSSIBLE IN SHOWERS/THUNDERSTORMS
WEDNESDAY NIGHT AND AGAIN ON SATURDAY.
&&
.MARINE...
LIGHT TO MODERATE SOUTHWEST FLOW EXPECTED TO CONTINUE TONIGHT AS LOW
OVER MN DEEPENS INTERACTS WITH HIGH OVER THE SOUTHEAST U.S. TO
PRODUCE WINDS AROUND 10 KT WITH GUSTS TO 15 KT. WAVES WILL BE AROUND
2 FT GIVE OR TAKE A FOOT INTO THURSDAY.
THURSDAY WINDS WILL SHIFT TO THE NORTH AS HIGH PRES OVER NORTH
CENTRAL CANADA SINKS SOUTH. THE GRADIENT BETWEEN THIS HIGH PRESSURE
AND THE ONE OVER THE SOUTHEAST IS WEAK AS THE ONE TO THE SOUTH
BREAKS DOWN. THIS HIGH WILL SLIDE EAST FRIDAY AND WINDS WILL ONCE
AGAIN SWITCH AROUND TO THE SOUTHWEST BY FRIDAY. A COLD FRONT WILL
SINK SOUTH INTO THE AREA SATURDAY WITH WINDS SHIFTING TO THE NORTH.
WINDS AND SEAS WILL INCREASE AS THE FRONT SINKS SOUTH...WITH N WINDS
APPROACHING OR EXCEEDING 15 KT. SEAS LOOK TO BUILD TO 2 TO 3 FEET.
NO HEADLINES EXPECTED THROUGH THE FORECAST PERIOD. TEMPS WILL BE
WARM ENOUGH EACH AFTERNOON TO SUPPORT A LAKE BREEZE WHICH CAN LOCALLY
SHIFT WINDS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR OHZ007>014-
018>023-027>033-036>038-047.
EXCESSIVE HEAT WARNING UNTIL 9 PM EDT THIS EVENING FOR OHZ003-
006-017.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...REL
AVIATION...REL
MARINE...JAMISON
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
204 PM EDT WED JUL 4 2012
.SYNOPSIS...
A STATIONARY FRONT LIES JUST NORTH OF THE AREA AND WILL EVENTUALLY
BECOME A BACK DOOR COLD FRONT THURSDAY MORNING. THE FRONT WILL
DISSIPATE AS WEAK HIGH PRESSURE BUILDS SOUTH OVER THE REGION BY
FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SOME CUMULUS DEVELOPING...TIMING OF WHEN THE THUNDERSTORMS WILL
DEVELOP IS STILL TOUGH...THINKING AFTER 3 PM. PLENTY OF CLOUDS
OVER NORTHWEST PA FROM THE COMPLEX THAT MOVED THROUGH EARLIER.
STILL THINKING THAT SOME OF THE THUNDERSTORMS COULD BE SEVERE LATE
THIS AFTERNOON AND EVENING. THE HRRR MODEL IS RELATIVELY DRY...NOT
SURE ABOUT THIS. THE SREF MODEL SEEMS TO HAVE A BETTER HANDLE ON
THING.
NOT MUCH CHANGE FOR THE HIGHS. A FEW PLACES MAY BREAK A
RECORD...TOL RECORD IS 99...FDY 97 AND MFD 94.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
THE HEAT AND HUMIDITY WILL CONTINUE TONIGHT ACROSS THE FORECAST
AREA AS VERY WARM AIR MASS REMAINS IN PLACE OVERNIGHT. TEMPERATURES
AND HUMIDITY WILL MAKE IT VERY UNCOMFORTABLE OVERNIGHT. AS THE NIGHT
PROGRESSES...THE THREAT FOR THUNDERSTORM ACTIVITY WILL PUSH SOUTH AS
THE WEAK COLD FRONT AND HIGH PRESSURE NUDGE THEIR WAY SOUTH INTO THE
AREA.
THE COLD FRONT EVENTUALLY WASHES OUT ON THURSDAY AS UPPER LEVEL
RIDGE REALLY SURGES EAST OVER THE FORECAST AREA. SUPPRESSION FROM
THE RIDGE SHOULD KEEP THREAT FOR SHOWERS AND THUNDERSTORMS AT BAY.
THIS MEANS CONTINUED HOT AND HUMID CONDITIONS FOR THURSDAY. LOOKING
AT TEMPERATURES RELATIVELY CLOSE TO TODAY...ESPECIALLY IN THE WEST
WITH COOLER TEMPERATURES IN THE EAST. MAY NEED ANOTHER HEAT ADVISORY
IN THE WEST AGAIN FOR TOMORROW.
SURFACE HIGH AND WEAK COOL AIR ADVECTION SHIFT BACK EAST THURSDAY
NIGHT AND THE HEAT SURGES BACK INTO THE FORECAST AREA FOR FRIDAY.
HEAT ADVISORIES LIKELY AGAIN ON FRIDAY AS WELL.
THE THREAT FOR SHOWERS AND THUNDERSTORMS RETURN ONCE AGAIN FRIDAY
NIGHT INTO SATURDAY AS NEXT BACK DOOR COLD FRONT SLIDES SOUTH TO
JUST NORTH OF LAKE ERIE BY SATURDAY EVENING. A SLIGHT BREAK DOWN IN
THE UPPER LEVEL RIDGE IN THE CENTRAL UNITED STATES WILL ALLOW FOR
SOME TROUGHINESS TO DEVELOP IN THE EASTERN UNITED STATES BY
SATURDAY. THIS WILL ALLOW THE COLD FRONT TO SLIDE SOUTH ACROSS THE
AREA SATURDAY NIGHT. A SHOT OF MOISTURE WILL RACE EAST ALONG THE
BOUNDARY AT THIS TIME AND BRING THE THREAT FOR SHOWERS AND
THUNDERSTORMS ALONG WITH THE BEGINNING OF A COOL DOWN.
IN THE MEAN TIME...TEMPERATURES REMAIN RATHER WARM THROUGH SATURDAY
UNTIL THE FRONT ARRIVES.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
THE MODELS CONTINUE TO SHOW THE NEXT COLD FRONT ON SATURDAY. THEY
ALSO CONTINUE TO SHOW A FAIR AMOUNT OF CLOUDS AND A LINGERING CHANCE
OF SHOWERS/STORMS ON SUNDAY...PERHAPS A LITTLE OVER RUNNING OF THE
SHALLOW FRONT. I LOWERED THE HIGH TEMPERATURE FORECAST ON SUNDAY TO
THE LOWER/MID 80S. IT COULD BE COOLER THAN THAT BASED ON THE NORTH
WIND AND THE THREAT OF CLOUDS/SHOWERS. IF SO... THE DIFFERENCE IN
TEMPERATURE FROM SATURDAY TO SUNDAY COULD BE DRAMATIC.
DRY AND COOLER WEATHER IS EXPECTED MONDAY AND TUESDAY NEXT WEEK.
TEMPERATURES WILL DROP BACK TO NEAR NORMAL..PERHAPS A CATEGORY OR SO
BELOW NORMAL.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
TIMING AND COVERAGE OF CONVECTIVE DEVELOPMENT THIS AFTERNOON AND OVERNIGHT IS
DIFFICULT TO DISCERN. THERE IS EXTREME INSTABILITY OVER THE REGION
WITH CAPE NEAR 4500 J/KG WITH A SINGLE CONVECTIVE CELL DEVELOPING
NW OF GKJ. HOURLY MODEL RUNS OF HRRR HAVE BEEN QUITE VARIABLE IN
STORM DEVELOPMENT. WITH COVERAGE UNCERTAIN WILL LEAVE MENTION OF
STORMS OUT OF THE TAFS FOR NOW. THE BEST CHANCE MAY BE IN KYNG
AREA THIS AFTERNOON. GENERALLY VFR CONDITIONS ARE EXPECTED INTO
THE NIGHT WITH PERHAPS MVFR WITH HAZE AND LIGHT FOG FROM 08Z- 12Z
MAINLY INLAND FROM THE LAKE.
.OUTLOOK...NON VFR CONDITIONS POSSIBLE IN SHOWERS/THUNDERSTORMS
WEDNESDAY NIGHT AND AGAIN ON SATURDAY.
&&
.MARINE...
WEATHER FEATURES WILL CONTINUE TO BE WEAK AS WILL BE THE ASSOCIATED
PRESSURE GRADIENTS. A WEAK WARM FRONT SHOULD PUSH NORTH OF LAKE ERIE
TODAY WITH A SOUTH TO SOUTHWEST WIND. THE FRONT MAY DRIFT BACK SOUTH
ACROSS THE LAKE ON THURSDAY AS HIGH PRESSURE BUILDS ACROSS CANADA SO
WINDS MAY VEER MORE FROM THE NORTH. THE WARM FRONT SHOULD PUSH BACK
NORTH OF LAKE ERIE AGAIN ON FRIDAY WITH THE WIND COMING BACK AROUND
FROM THE SOUTH. LAKE/LAND BREEZES ARE LIKELY EACH DAY AND NIGHT. A
STRONGER COLD FRONT WILL DROP SOUTH ACROSS THE LAKE ON SATURDAY AND
CANADIAN HIGH PRESSURE WILL BUILD SOUTH ACROSS THE LAKES EARLY NEXT
WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR OHZ007>014-
018>023-027>033-036>038-047.
EXCESSIVE HEAT WARNING UNTIL 9 PM EDT THIS EVENING FOR OHZ003-
006-017.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...KIELTYKA
SHORT TERM...LOMBARDY
LONG TERM...REL
AVIATION...REL
MARINE...KOSARIK
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
146 PM EDT WED JUL 4 2012
.SYNOPSIS...
LIGHT WEST TO SOUTHWEST WINDS WILL ACCOMPANY BUILDING HIGH
PRESSURE IN THE MID LEVELS OF THE ATMOSPHERE FOR THE NEXT FEW
DAYS. NORTHWEST FLOW ALOFT WILL PERMIT INTERMITTENT DISTURBANCES
TO CROSS THE OHIO VALLEY AND POTENTIALLY INITIATE THUNDERSTORM
ACTIVITY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLEAR SKIES ACROSS THE AREA THIS MORNING AS UPPER LEVEL RIDGE
REMAINS CENTERED OFF TO OUR WEST. SIMILAR SITUATION TODAY AS WITH
THE PAST FEW AS BEST CHANCE FOR ANY THUNDERSTORM ACTIVITY SHOULD BE
ACROSS OUR EAST...IN THE AREA CLOSER TO MORE FAVORABLE NORTHWEST
FLOW ALOFT. WITH 850 MB TEMPERATURES NUDGING UP A BIT...EXPECT
HIGHS TODAY TO BE A DEGREE OR TWO WARMER THAN YESTERDAY. THIS
COMBINED WITH DEWPOINTS IN THE UPPER 60S...WILL PUSH US UP CLOSE TO
EXCESSIVE HEAT WARNING CRITERIA...ESPECIALLY ACROSS OUR NORTHWEST.
IN ORDER TO AVOID A PATCH WORK OF WARNING AND ADVISORIES...HAVE
OPTED TO INCLUDE ALL OF OUR WEST IN AN EXCESSIVE HEAT WARNING FOR
TODAY. WHILE WE MAY NOT QUITE MAKE IT...DECIDED TO ERROR ON THE
SIDE OF CAUTION WITH ALL OF THE OUTDOOR HOLIDAY ACTIVITY TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
MODELS APPEAR TO BE HOLDING BACK ON THE INITIATION OF CONVECTION
AND WITH THE BUILDING MID LEVEL RIDGE...THE CAP WILL BE
INCREASINGLY HARDER TO BREAK AS THIS RIDGE BUILDS. NAM AND GFS ARE
KEYING ON A WEAK VORT MAX SWINGING SOUTH ALONG THE IN/OH BORDER
TONIGHT...CANADIEN AND EUROPEAN ARE MORE MUTED WITH THIS SCENARIO.
COULD NOT GO DRY BUT DID NOT FEEL THAT THE CHANCE FOR SHOWERS WERE
THAT GREAT.
EACH DAY SHOULD GET PROGRESSIVELY WARMER THROUGH SATURDAY. A COLD
FRONT WILL MOVE THROUGH THIS TIME AND SHOULD BRING MUCH MORE MUTED
HIGHS TO THE REGION FOR NEXT WEEK.
THOUGHT THAT LOW TEMPERATURES WERE A BIT TOO WARM CONSIDERING
DEWPOINTS IN THE UPPER 60S WOULD LET SOME SPOTS DROP DOWN A BIT
LOWER TOWARDS THE 70 DEGREE MARK. BUMPED OVERNIGHT LOWS DOWN JUST
A BIT...PARTICULARLY SATURDAY NIGHT WHERE MID 70S IN THE SOUTHWEST
WAS JUST TOO WARM CONSIDERING THE FRONT IS EXPECTED TO APPROACH
THE OHIO RIVER AT THIS TIME.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
BY SUNDAY...THE ECMWF AND GFS ARE BOTH INDICATING THE BEGINNING
OF A TRANSITION. A BOUNDARY WILL BE SLOWLY MOVING SOUTH THROUGH
THE OHIO VALLEY...AS DRY HIGH PRESSURE ESTABLISHES ITSELF OVER THE
GREAT LAKES. WHILE THE TIMING DIFFERENCES BETWEEN THE MODELS AND
THEIR SUBSEQUENT RUNS DO NOT ALLOW FOR COMPLETE CERTAINTY...IT IS
OBVIOUS THAT THE TREND WILL BE FOR COOLING CONDITIONS IN THE
SUNDAY THROUGH TUESDAY TIME FRAME. CHANCE POPS WILL ALSO BE USED
FOR BOTH SUNDAY AND MONDAY. ONE REMAINING UNCERTAINTY IS IF THE
TEMPERATURE FORECAST FOR SUNDAY WILL BE ENOUGH TO SUPPORT
ADDITIONAL HEADLINES...AND THIS WILL ONLY BE ABLE TO BE REFINED
ONCE THE FRONTAL TIMING IS MORE CERTAIN. IT IS POSSIBLE THAT A
NORTH-TO-SOUTH GRADIENT WILL EXIST ACROSS THE CWA.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
CU FIELD HAS FILLED IN NICELY ACROSS THE AREA EARLY THIS AFTERNOON
AS THE AIRMASS CONTINUES TO DESTABILIZE. THE CU LOOKS A LITTLE
BETTER DEFINED ACROSS OUR NORTH ON THE VISIBLE SATELLITE AND THIS
IS WHERE THE LAST COUPLE RUNS OF THE HRRR HAVE TRIED TO GENERATE
SOME ISOLATED TO SCATTERED CONVECTION BY MID AFTERNOON. THE 12Z
NAM IS ALSO SHOWING THE POSSIBILITY OF SOME CONVECTION ACROSS AT
LEAST CENTRAL OHIO LATER THIS AFTERNOON. WOULD THEREFORE THINK
THAT KCMH/KLCK WILL WOULD HAVE THE BEST CHANCE OF SEEING ANY
DEVELOPMENT AS WE HEAD THROUGH THE AFTERNOON HOURS INTO EARLY
EVENING. SOME UNCERTAINTY STILL EXISTS FOR ANY CONVECTION
OVERNIGHT SO WILL LEAN TO TH DRIER SIDE AND HOLD OFF ON INCLUDING
ANYTHING IN THE TAFS ATTM.
OUTLOOK...THUNDERSTORMS POSSIBLE SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...EXCESSIVE HEAT WARNING UNTIL 8 PM EDT THIS EVENING FOR OHZ026-
034-035-042>044-051>053-060-062-070>072-078.
HEAT ADVISORY FROM 8 PM THIS EVENING TO 8 PM EDT SATURDAY FOR
OHZ026-034-035-042>044-051>053-060-062-070>072-078.
HEAT ADVISORY UNTIL 8 PM EDT SATURDAY FOR OHZ045-046-054>056-
063>065-073-074-079>082-088.
EXCESSIVE HEAT WARNING UNTIL 8 PM EDT SATURDAY FOR OHZ061-077.
KY...EXCESSIVE HEAT WARNING UNTIL 8 PM EDT THIS EVENING FOR
KYZ089>096.
HEAT ADVISORY FROM 8 PM THIS EVENING TO 8 PM EDT SATURDAY FOR
KYZ089>096.
HEAT ADVISORY UNTIL 8 PM EDT SATURDAY FOR KYZ097>100.
IN...EXCESSIVE HEAT WARNING UNTIL 8 PM EDT THIS EVENING FOR INZ050-
058-059-066-073>075-080.
HEAT ADVISORY FROM 8 PM THIS EVENING TO 8 PM EDT SATURDAY FOR
INZ050-058-059-066-073>075-080.
&&
$$
SYNOPSIS...FRANKS
NEAR TERM...JGL
SHORT TERM...FRANKS
LONG TERM...HATZOS
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1226 PM EDT WED JUL 4 2012
.SYNOPSIS...
A STATIONARY FRONT LIES JUST NORTH OF THE AREA AND WILL EVENTUALLY
BECOME A BACK DOOR COLD FRONT THURSDAY MORNING. THE FRONT WILL
DISSIPATE AS WEAK HIGH PRESSURE BUILDS SOUTH OVER THE REGION BY
FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SOME CUMULUS DEVELOPING...TIMING OF WHEN THE THUNDERSTORMS WILL
DEVELOP IS STILL TOUGH...THINKING AFTER 3 PM. PLENTY OF CLOUDS
OVER NORTHWEST PA FROM THE COMPLEX THAT MOVED THROUGH EARLIER.
STILL THINKING THAT SOME OF THE THUNDERSTORMS COULD BE SEVERE LATE
THIS AFTERNOON AND EVENING. THE HRRR MODEL IS RELATIVELY DRY...NOT
SURE ABOUT THIS. THE SREF MODEL SEEMS TO HAVE A BETTER HANDLE ON
THING.
NOT MUCH CHANGE FOR THE HIGHS. A FEW PLACES MAY BREAK A
RECORD...TOL RECORD IS 99...FDY 97 AND MFD 94.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
THE HEAT AND HUMIDITY WILL CONTINUE TONIGHT ACROSS THE FORECAST
AREA AS VERY WARM AIR MASS REMAINS IN PLACE OVERNIGHT. TEMPERATURES
AND HUMIDITY WILL MAKE IT VERY UNCOMFORTABLE OVERNIGHT. AS THE NIGHT
PROGRESSES...THE THREAT FOR THUNDERSTORM ACTIVITY WILL PUSH SOUTH AS
THE WEAK COLD FRONT AND HIGH PRESSURE NUDGE THEIR WAY SOUTH INTO THE
AREA.
THE COLD FRONT EVENTUALLY WASHES OUT ON THURSDAY AS UPPER LEVEL
RIDGE REALLY SURGES EAST OVER THE FORECAST AREA. SUPPRESSION FROM
THE RIDGE SHOULD KEEP THREAT FOR SHOWERS AND THUNDERSTORMS AT BAY.
THIS MEANS CONTINUED HOT AND HUMID CONDITIONS FOR THURSDAY. LOOKING
AT TEMPERATURES RELATIVELY CLOSE TO TODAY...ESPECIALLY IN THE WEST
WITH COOLER TEMPERATURES IN THE EAST. MAY NEED ANOTHER HEAT ADVISORY
IN THE WEST AGAIN FOR TOMORROW.
SURFACE HIGH AND WEAK COOL AIR ADVECTION SHIFT BACK EAST THURSDAY
NIGHT AND THE HEAT SURGES BACK INTO THE FORECAST AREA FOR FRIDAY.
HEAT ADVISORIES LIKELY AGAIN ON FRIDAY AS WELL.
THE THREAT FOR SHOWERS AND THUNDERSTORMS RETURN ONCE AGAIN FRIDAY
NIGHT INTO SATURDAY AS NEXT BACK DOOR COLD FRONT SLIDES SOUTH TO
JUST NORTH OF LAKE ERIE BY SATURDAY EVENING. A SLIGHT BREAK DOWN IN
THE UPPER LEVEL RIDGE IN THE CENTRAL UNITED STATES WILL ALLOW FOR
SOME TROUGHINESS TO DEVELOP IN THE EASTERN UNITED STATES BY
SATURDAY. THIS WILL ALLOW THE COLD FRONT TO SLIDE SOUTH ACROSS THE
AREA SATURDAY NIGHT. A SHOT OF MOISTURE WILL RACE EAST ALONG THE
BOUNDARY AT THIS TIME AND BRING THE THREAT FOR SHOWERS AND
THUNDERSTORMS ALONG WITH THE BEGINNING OF A COOL DOWN.
IN THE MEAN TIME...TEMPERATURES REMAIN RATHER WARM THROUGH SATURDAY
UNTIL THE FRONT ARRIVES.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
THE MODELS CONTINUE TO SHOW THE NEXT COLD FRONT ON SATURDAY. THEY
ALSO CONTINUE TO SHOW A FAIR AMOUNT OF CLOUDS AND A LINGERING CHANCE
OF SHOWERS/STORMS ON SUNDAY...PERHAPS A LITTLE OVER RUNNING OF THE
SHALLOW FRONT. I LOWERED THE HIGH TEMPERATURE FORECAST ON SUNDAY TO
THE LOWER/MID 80S. IT COULD BE COOLER THAN THAT BASED ON THE NORTH
WIND AND THE THREAT OF CLOUDS/SHOWERS. IF SO... THE DIFFERENCE IN
TEMPERATURE FROM SATURDAY TO SUNDAY COULD BE DRAMATIC.
DRY AND COOLER WEATHER IS EXPECTED MONDAY AND TUESDAY NEXT WEEK.
TEMPERATURES WILL DROP BACK TO NEAR NORMAL..PERHAPS A CATEGORY OR SO
BELOW NORMAL.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
NOT A LOT OF CONFIDENCE ON THE POTENTIAL LOCATION AND TIMING OF
THUNDERSTORMS TODAY INTO TONIGHT. THERE WILL BE A CONTINUED THREAT
AROUND THE "RING OF FIRE" NEAR THE WARM FRONT. THE FIRST CHANCE IS
WITH THE STORMS DROPPING SOUTH FROM LAKE HURON. THEY SEEMED TO BE
AIMED AT KERI AND PERHAPS KYNG MIDDAY AND AFTERNOON. THEY COULD
EXPAND TO OTHER LOCATIONS ACROSS NE OH THIS AFTERNOON. SOME OF
THE MODELS INDICATE A SECOND ROUND OF THUNDERSTORMS THIS EVENING
OR EARLY TONIGHT ACROSS NW OH AND NORTH CENTRAL OHIO. VFR
CONDITIONS ARE EXPECTED OTHERWISE.
.OUTLOOK...NON VFR CONDITIONS POSSIBLE IN SHOWERS/THUNDERSTORMS
WEDNESDAY NIGHT AND AGAIN ON SATURDAY.
&&
.MARINE...
WEATHER FEATURES WILL CONTINUE TO BE WEAK AS WILL BE THE ASSOCIATED
PRESSURE GRADIENTS. A WEAK WARM FRONT SHOULD PUSH NORTH OF LAKE ERIE
TODAY WITH A SOUTH TO SOUTHWEST WIND. THE FRONT MAY DRIFT BACK SOUTH
ACROSS THE LAKE ON THURSDAY AS HIGH PRESSURE BUILDS ACROSS CANADA SO
WINDS MAY VEER MORE FROM THE NORTH. THE WARM FRONT SHOULD PUSH BACK
NORTH OF LAKE ERIE AGAIN ON FRIDAY WITH THE WIND COMING BACK AROUND
FROM THE SOUTH. LAKE/LAND BREEZES ARE LIKELY EACH DAY AND NIGHT. A
STRONGER COLD FRONT WILL DROP SOUTH ACROSS THE LAKE ON SATURDAY AND
CANADIAN HIGH PRESSURE WILL BUILD SOUTH ACROSS THE LAKES EARLY NEXT
WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR OHZ007>014-
018>023-027>033-036>038-047.
EXCESSIVE HEAT WARNING UNTIL 9 PM EDT THIS EVENING FOR OHZ003-
006-017.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...KIELTYKA
SHORT TERM...LOMBARDY
LONG TERM...KOSARIK
AVIATION...KOSARIK
MARINE...KOSARIK
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
201 AM EDT WED JUL 4 2012
.SYNOPSIS...
LIGHT WINDS AT THE SURFACE AND BUILDING MID LEVEL RIDGING TO OUR
WEST WILL KEEP THE OHIO VALLEY VERY WARM FOR THE NEXT SEVERAL
DAYS. NORTHWEST FLOW AROUND THE RIDGE WILL CONTINUE TO BRING
INTERMITTENT DISTURBANCES ACROSS THE OHIO VALLEY THROUGHOUT THIS
TIME PERIOD.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AN EMBEDDED S/WV WITHIN A NW FLOW ALOFT WILL PIVOT SE ACRS THE
ERN GREAT LAKES THIS EVENING...PUSHING SE TO ERN OHIO/PA
OVERNIGHT. LATEST RAP DOES SHOW SOME 925 MB-850 MB LOW LEVEL
CONVERGENCE SKIMMING OUR NE COUNTIES THIS EVENING/OVERNIGHT AS
AFOREMENTIONED S/WV CONTINUES ITS MOVEMENT SE. HRRR INDICATES THAT
NE COUNTIES COULD GET GRAZED BY A SHOWER OR THUNDERSTORM DURING
THIS PERIOD. PREFER TO NOT WET UP THE FORECAST AFTER GOING DRY
PREVIOUSLY SO WILL MONITOR MODEL AND RADAR TRENDS AND UPDATE
FORECAST IF IT BECOMES APPARENT THAT THE FAR NE MAY RUN A RISK FOR
AN ISOLATED SHOWER/STORM. MODELS REMAIN UNCLEAR WHETHER AN MCS
WILL DEVELOP OVER MN/WISCONSIN THIS EVENING/OVERNIGHT...DIVING SE
TOWARD THE LOWER GREAT LAKES BY MORNING. SO...WILL CONTINUE WITH A
DRY FORECAST WITH MOSTLY CLEAR SKIES.
USED A BLEND OF ARW/ECMWF FOR OVERNIGHT LOWS TONIGHT WHICH YIELDS
UPPER 60S ACROSS THE EAST TO LOW 70S ACROSS THE WEST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
THE MID LEVEL RIDGE AMPLIFIES A BIT ON INDEPENDENCE DAY. THIS WILL
RESULT IN A MORE NORTH TO SOUTH COMPONENT TO THE PROPAGATION OF MID
AND UPPER LEVEL ENERGY TRAVELING ALONG THE PERIPHERY OF THE RIDGE
DURING THIS PERIOD. THE POTENTIAL EXISTS OF A DISTURBANCE TO DROP
SOUTH FROM EASTERN MICHIGAN DURING THE AFTERNOON...WHICH WOULD
RESULT IN THUNDERSTORM DEVELOPMENT TOWARD OUR AREA DURING THE LATE
AFTERNOON AND EVENING. THIS SCENARIO IS DEPICTED BY THE 12Z ARW
AND NAM...BUT NOT BY THE NMM. BASED ON HOW WELL THE ARW PERFORMED
24 HORUS OUT FOR THE PAST TWO EVENTS THIS WEEK...HAVE UPPED THE
POPS TO 50 FOR INDEPENDENCE DAY. AVOIDED GOING ANY HIGHER FOR POPS AT
THIS POINT DUE TO THE UNCERTAINTIES IN THE MODELS DURING THESE
MODES OF CONVECTION.
HAVE BACKED OFF ON HIGH TEMPERATURES A BIT FOR TOMORROW GIVEN THE
LOW TO MID 90S SEEN TODAY...AND THE POSSIBILITY OF CONVECTION BY
TOMORROW AFTERNOON. HOWEVER...THESE TEMPERATURES WILL STILL BE IN
THE LOW TO MID 90S AS WELL. THIS WILL COMBINE WITH DEWPOINTS IN
THE UPPER 60S TO PRODUCE HEAT INDICES UP TO 100 ACROSS MUCH OF OUR
AREA DURING THE LATE AFTERNOON. OVERNIGHT LOWS TOMORROW NIGHT WILL
ONLY DIP INTO THE LOW TO MIDDLE 70S. AND...AT THE SAME TIME
SEVERAL COUNTIES STILL HAVE REDUCED HEAT ADVISORY CRITERIA DUE TO
ONGOING POWER OUTAGES FROM SEVERE STORMS THIS PAST WEEKEND. ALL OF
THE ABOVE COMBINED TO JUSTIFY THE ISSUANCE OF A HEAT ADVISORY FOR ALL
COUNTIES EXCEPT MONTGOMERY AND HAMILTON FROM NOON ON INDEPENDENCE
DAY THROUGH THE END OF THE SHORT TERM. AN EXCESSIVE HEAT WARNING
HAS BEEN ISSUED FOR THE SAME TIME PERIOD FOR HAMILTON AND
MONTGOMERY COUNTIES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THE OVERALL PATTERN WILL CHANGE ONLY SLIGHTLY THROUGH THE
WEEKEND...AS THE CENTER OF THE HIGH PRESSURE RIDGE MOVES SLIGHTLY
NORTH THROUGH THE MISSISSIPPI VALLEY. THIS WILL PUT THE CWA IN AN
AREA OF WEAK NORTHERLY FLOW ALOFT...BUT WITH THE EDGE OF THE RIDGE
STILL AFFECTING THE CWA...AND A VERY WEAK SURFACE PRESSURE PATTERN.
THURSDAY THROUGH SATURDAY APPEAR TO BE THE HOTTEST DAYS OF THE
FORESEEABLE FUTURE. WITH LOWS ABOVE 70 DEGREES AND A FORECAST
SOLIDLY SUPPORTING HEAT INDICES ABOVE 100 DEGREES FOR EACH OF THESE
THREE DAYS...THE HEAT ADVISORY HAS BEEN EXTENDED THROUGH SATURDAY.
AT THE SAME TIME...IT WOULD BE HARD TO COMPLETELY RULE OUT A SHOWER
OR THUNDERSTORM AT TIMES DURING THIS PERIOD...GIVEN THE EXPECTED
INSTABILITY. HOWEVER...FORCING SIGNALS ARE UNCERTAIN...AND MOST OF
THIS PERIOD HAS BEEN LEFT DRY IN THE GRIDS.
BY SUNDAY...THE ECMWF AND GFS ARE BOTH INDICATING THE BEGINNING OF A
TRANSITION. A BOUNDARY WILL BE SLOWLY MOVING SOUTH THROUGH THE OHIO
VALLEY...AS DRY HIGH PRESSURE ESTABLISHES ITSELF OVER THE GREAT
LAKES. WHILE THE TIMING DIFFERENCES BETWEEN THE MODELS AND THEIR
SUBSEQUENT RUNS DO NOT ALLOW FOR COMPLETE CERTAINTY...IT IS OBVIOUS
THAT THE TREND WILL BE FOR COOLING CONDITIONS IN THE SUNDAY THROUGH
TUESDAY TIME FRAME. CHANCE POPS WILL ALSO BE USED FOR BOTH SUNDAY
AND MONDAY. ONE REMAINING UNCERTAINTY IS IF THE TEMPERATURE FORECAST
FOR SUNDAY WILL BE ENOUGH TO SUPPORT ADDITIONAL HEADLINES...AND THIS
WILL ONLY BE ABLE TO BE REFINED ONCE THE FRONTAL TIMING IS MORE
CERTAIN. IT IS POSSIBLE THAT A NORTH-TO-SOUTH GRADIENT WILL EXIST
ACROSS THE CWA.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
H5 RIDGE THAT HAS BEEN AFFECTING THE REGION FOR ALMOST A WEEK WILL
FLUCTUATE AGAIN TODAY...WITH THE CENTER SLIPPING EWD A LITTLE. THIS
WILL CAUSE THE MID AND UPPER LEVEL FLOW TO BECOME MORE NORTH/SOUTH
ORIENTED. THIS MAY ALLOW EMBEDDED DISTURBANCES TO DRIFT DOWN FROM
THE NORTH LATE IN THE DAY. MODELS DIFFER ON WHETHER THIS IS ENUF
TO KICK OFF CONVECTION AS DISTURBANCE INTERACTS WITH THE MOIST AND
UNSTABLE AIRMASS OVER THE REGION.
GIVEN THE TIMING ISSUE OF THESE DISTURBANCES AND THE QUESTION OVER
COVERAGE...WILL CONTINUE TO KEEP TAFS DRY.
SOME MVFR FOG IS POSSIBLE THIS MORNING...ESPECIALLY AT ILN/LUK
OUTLOOK...THUNDERSTORMS POSSIBLE SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT SATURDAY FOR OHZ026-
034-035-042>046-051>056-060-062>065-070>074-078>082-088.
EXCESSIVE HEAT WARNING FROM NOON TODAY TO 8 PM EDT SATURDAY
FOR OHZ061-077.
KY...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT SATURDAY FOR
KYZ089>100.
IN...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT SATURDAY FOR INZ050-
058-059-066-073>075-080.
&&
$$
SYNOPSIS...LATTO
NEAR TERM...HICKMAN/LATTO
SHORT TERM...LATTO
LONG TERM...HATZOS
AVIATION...SITES
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
152 AM EDT WED JUL 4 2012
.SYNOPSIS...
NORTHWEST FLOW ALOFT WILL CONTINUE THROUGH THURSDAY. UPPER LEVEL
HIGH PRESSURE WILL BUILD INTO THE AREA LATER IN THE WEEK...BEFORE
NORTHWEST FLOW REDEVELOPS FOR SUNDAY AND CONTINUES INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
TRIED TO DRY OUT AREA BEHIND S/W TROF AXIS OVERNIGHT INTO WED
MORNING...WHICH WAS JUST APPROACHING THE OHIO RIVER. OTHERWISE FCST
ON TRACK.
10 PM UPDATE...
WILL UPDATE THE FORECAST TO BETTER REPRESENT CURRENT RADAR
TRENDS...LOWERING IN MOST AREAS BUT RAISING A BIT NEAR A BOUNDARY
WHERE THE CURRENT STORMS ARE TRACKING.
PREV DISCN...
UPPER LEVEL HIGH CENTERED OVER THE MID WEST WITH UPPER LEVEL
DISTURBANCES DROPPING SOUTHEAST THRU THE CWA WILL CONTINUE THIS
PERIOD. WITH A HOT AND HUMID AND CONDITIONALLY UNSTABLE ATMOSPHERE
IN PLACE...THE THREAT FOR THUNDERSTORMS PERSIST. THE BEST
OPPORTUNITY FOR STORMS WILL BE DUE TO MESOSCALE INFLUENCES AND
DIURNALLY DRIVEN. SO THE BEST CHANCE OF STORMS WILL BE AFTERNOON AND
EVENING...ALTHOUGH WILL HAVE TO LEAVE SLIGHT CHANCE OVERNIGHT. AS
USUAL IN THIS REGIME...THE HI RES MODELS WERE USED VERY HEAVILY.
THE HRRR HI RES MODEL SEEMS TO HANDLE A COMPLEX DROPPING SOUTHEAST
FROM EASTERN OHIO THIS AFTERNOON PER RADAR TRENDS...SO WILL HAVE
HIGHEST POPS THRU THIS EVENING IN NORTHEASTERN WV.
OTHERWISE...CHANCE FOR DIURNALLY FAVORED TIMES AND SLIGHT CHAN
TONIGHT.
GOING ON THE HIGH END OF GUIDANCE FOR TEMPS...ALTHOUGH ANY TSTM
ACTIVITY WOULD VARY THAT.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
MODELS SUGGEST AN ACTIVE 4TH OF JULY FOR SECTIONS OF THE CWA.
ANOTHER MCS IS FORECAST TO DEVELOP AND MOVE SOUTH FROM THE GREAT
LAKES. WILL HAVE TO MONITOR THIS VERY CLOSELY. CONDITIONS ARE
FAVORABLE FOR THIS DEVELOPMENT AS NORTHWEST FLOW PERSISTS. THE EXACT
STRENGTH AND DIRECTION IS IN QUESTION.
THE CHANCE FOR THUNDERSTORMS DECREASE SLIGHTLY BY THURSDAY INTO
FRIDAY. THIS CONTINUES TO BE CONSISTENT WITH PREVIOUS FORECASTS.
WILL MAKE A FEW MINOR ADJUSTMENTS ONLY.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AS A FRONTAL SYSTEM
SLIDES SOUTH THIS WEEKEND. SURFACE HIGH PRESSURE WILL FOLLOW THIS
SYSTEM. ONCE AGAIN...THE CWA IS IN NORTHWEST FLOW AS AN UPPER LOW IS
NORTHEAST AND A RIDGE OF HIGH PRESSURE IS SOUTHWEST. HAVE FOLLOWED
HPC AND KEPT HOT TEMPS AND CONTINUED THUNDERSTORM CHANCES THROUGH
MUCH OF THIS PERIOD.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
06Z TUESDAY THRU 06Z WEDNESDAY...
UPPER HIGH ANCHORED OVER THE MID WEST WITH NORTHWEST FLOW ALOFT OVER
THE OHIO VALLEY THIS PERIOD. CONDITIONALLY UNSTABLE ATMOSPHERE WILL
LEAD TO SCATTERED MAINLY AFTERNOON AND EVENING TSTMS. OTHERWISE...
EXCEPT FOR LOCALLY MVFR TO IFR RIVER AND VALLEY FOG 07Z TO 12Z
WED...EXPECT VFR OUTSIDE OF CONVECTION. FOG MAY START TO REFORM
TOWARD 06Z THU...DEPENDING UPON WHERE IT RAINS WED AFTERNOON AND
EVENING.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z THURSDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: FOG TIMING EVOLUTION AND INTENSITY MAY VARY
OVERNIGHT. TAFS WILL NEED UPDATED WED AFTERNOON AND EVENING IN
RESPONSE TO WHERE CONVECTION INITIATES.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE WED 07/04/12
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
CRW CONSISTENCY H M M M M L L M H H H H
HTS CONSISTENCY H H M M M L M M M H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H L L L L H H H H H
PKB CONSISTENCY H M M M L L L M M H H H
CKB CONSISTENCY L L L L L L L L M H H H
AFTER 06Z THURSDAY...
NO WIDESPREAD IFR CONDITIONS EXPECTED AT THIS TIME.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...HEAT ADVISORY FROM NOON TODAY TO 7 PM EDT THIS EVENING FOR
WVZ005>011-013>020-024>032.
OH...HEAT ADVISORY FROM NOON TODAY TO 7 PM EDT THIS EVENING FOR
OHZ066-067-075-076-083>087.
KY...HEAT ADVISORY FROM NOON TODAY TO 7 PM EDT THIS EVENING FOR
KYZ101>103-105.
VA...NONE.
&&
$$
SYNOPSIS...JB/JMV
NEAR TERM...TRM/RPY/JMV
SHORT TERM...JB
LONG TERM...JB
AVIATION...RPY/TRM
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1153 AM EDT WED JUL 4 2012
.SYNOPSIS...
HOT SUMMERTIME WEATHER CONDITIONS WILL PREVAIL ACROSS CENTRAL
PENNSYLVANIA INTO THE WEEKEND. THERE WILL BE A CHANCE FOR
AFTERNOON SHOWERS AND THUNDERSTORMS TODAY...FOLLOWED BY FAIR AND
DRY WEATHER FOR THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
ANOTHER UPDATE DONE LATE THIS AM. MAIN CHANGE WAS TO UP
POPS ACROSS THE NW...AND FAR WEST LATER. SMALL AREA WHERE
ONE CAN GET THE HIGHER DEWPOINTS ADVECTED EASTWARD ALONG
THE LAKESHORE AND KEEP THE SW FLOW...AND HIGHER CAPES. FURTHER
SOUTH...DEWPOINTS LOWER...BUT COMING UP...AND ALSO LESS HIGH
CLDS...SO NEW STORMS COULD STILL FORM LATER THIS AFT...EVEN
WITH CONDITIONS NOT AS GOOD AS FURTHER WEST.
EARLIER DISCUSSION BELOW.
SHOWERS AND ISOLD TSTMS WILL BE CONFINED TO THE SRN 1/3 OF THE
CWA EARLY THIS MORNING...AS SHORTWAVE TROF/VORTICITY AXIS
CONTINUES TO PUSH SEWD ACRS THE CENTRAL MTNS AND EXITS SE PA
SHORTLY AFTER 12Z. CONVECTIVE ELEMENTS...LKLY ELEVATED...LOCATED
ON THE SW FLANK OF THE VORT AXIS NEAR PITTSBURGH SHOULD CONTINUE
TO WEAKEN AS THEY MOVE SEWD INTO A MORE STABLE AIRMASS ALONG/EAST
OF THE LAUREL HIGHLANDS. SATL DATA SHOWS CLEARING TO THE NW OF
DUJ-ELM LINE WITH FOG DEVELOPING IN THE VALLEYS.
&&
.SHORT TERM / THURSDAY THROUGH 6 AM THURSDAY/...
WEAK SFC RIDGING AND HEIGHT RISES IN THE WAKE OF H5 TROF AXIS WILL
KEEP THINGS QUIET EARLY TODAY. HOWEVER ALL BETS ARE OFF FOR LATER
IN THE DAY...AS THE AREA REMAINS ON THE NERN FRINGE OF HOT CENTRAL
U.S. RIDGE WITHIN BELT OF NWLY FLOW ALOFT.
WITH A RATHER WEAK/NONDESCRIPT SFC PATTERN FCST TO BE IN PLACE
LACKING A TRUE FORCING/TRIGGERING MECHANISM FOR GENERATING
SUBSTANTIAL UPWARD VERTICAL MOTION...EXPECT ANY DIURNAL CONVECTIVE
ACTIVITY TO BE NON-FOCUSED AND DISORGANIZED...DRIVEN LARGELY BY
SMALL/SUBTLE VORTICITY MAXIMA ROTATING SEWD DOWN THE FRONT-SIDE OF
THE CENTRAL U.S. ANTICYCLONE. THE HI RES MDL DATA MAY BE PICKING
UP ON ONE OF THESE SMALL/SUBTLE SHORTWAVE IMPULSES WHICH APPEARS
TO HAVE INITIATED A CLUSTER OF TSTMS OVR THE THUMB OF LWR MI/LK
HURON. BOTH THE 3KM HRRR AND 4KM NAM SHOW THIS AREA OF CONVECTION
CROSSING LAKE ERIE AROUND MID MORNING AND ENTERING THE NW MTNS
AROUND 18Z.
GIVEN THE LOW CONFIDENCE FCST...BROAD-BRUSHED LOW TO MEDIUM CHC
POPS FOR THE AFTN/EVE HOURS. CVRG SHOULD BE ISOLD TO SCT GIVEN
WEAK FORCING AND MOIST/UNSTABLE CONDITIONS. SPC HAS MAINTAINED THE
SEE TEXT CATG D1 OUTLOOK WITH LOW-PROBABILITY OF SVR.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
BY THU...RIDGE FLATTENS AND BEGINS TO EXTEND FURTHER EASTWARD
INTO CENTRAL PA. THOUGH AN ISOLATED LATE AFTERNOON/EVE TSTM WILL
BE POSS OFF THE HIGHER TERRAIN IN THE SW...WARMING TEMPS ALOFT
SHOULD KEEP THESE TO A MINIMUM. WITH PLENTY OF SUNSHINE...TEMPS
WILL RISE TO THE LOW TO MID 90S. MORE HOT WEATHER IN STORE FOR FRI
AND SAT...WITH READINGS 10-15F ABOVE NORMAL /AND HEAT INDICES
APPROACHING 100F IN THE SE/. HEAT HEADLINES MAY BE A POSSIBILITY
IF DEWPOINTS INCH CLOSER TO 70F...BUT DEEPEST LOW LEVEL MOISTURE
WILL REMAIN OFF TO OUR WEST. FRIDAY IS THE DRIEST OF THE THREE
DAYS...WITH HIGHER DEWPOINT AMOUNTS THURSDAY AND SATURDAY. NIGHTS
WILL CONTINUE TO BE QUITE MUGGY AND WARM ACROSS THE SOUTH.
OVER THE WEEKEND...HIGH PRESSURE RIDGE IS MOVED WESTWARD BY AN
STRONG UPPER LEVEL LOW MOVING THROUGH CENTRAL CANADA. THIS WILL
BRING A MID LEVEL TROUGH TO SLOWLY SAG OVER THE REGION LATE
SATURDAY INTO SUNDAY. THIS WILL PUSH A COOL FRONT THROUGH THE
REGION FROM THE NORTH...WHICH WILL BRING RENEWED CHANCES FOR TSTMS
INITIALLY ACROSS THE NORTH LATE SATURDAY...AND THEN ACROSS PA
LAT SATURDAY NIGHT...EARLY SUNDAY. DRY COOLER AIR BEHIND THE FRONT
WILL GRADUALLY WORK IN LATE IN THE WEEKEND AND THROUGH EARLY NEXT
WEEK. THIS SHOULD BRING RELIEF FROM THE SUMMERTIME HEAT...DROPPING
TEMPS BACK TOWARD SEASONAL NORMALS THROUGH THE FIRST HALF OF NEXT
WEEK.
&&
.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
MAIN CHANGE WAS TO BFD TAF FOR MCS MOVING SE. HISTORY OF
GUSTY WINDS WITH GUSTY WINDS.
MINOR UPATES TO OTHER TAFS.
LOWER CLDS FINALLY BREAKING UP ACROSS THE NORTH.
EARLIER DISCSSION BELOW.
SCATTERED TSRA AND SHRA CONTINUE ACROSS THE FAR SOUTHERN TIER OF
PA THIS MORNING. LIGHT RAIN CONTINUES AT MDT AND LNS...THROUGH
THESE SHOWERS SHOULD ARE NOG REDUCING CONDITIONS AND SHOW END BY
12Z.
LOW CLOUDS HAVE FORMED OVER BFD...WITH LIFR CIGS. THESE CONDITIONS
SHOULD LIFT BETWEEN 12-14Z. LIGHT VALLEY FOG REMAINS POSSIBLE
UNTIL AROUND 15Z.
STORMS SHOULD REGENERATE MID TO LATE THIS AFTERNOON WITH WARM
TEMPERATURES AND HIGH DEWPOINTS. SHORT RANGE MODELS SUGGEST
ACTIVITY MOVES THROUGH LATE AFTERNOON...EARLY EVENING.
OUTLOOK...
THUR...AM FOG OTHERWISE VFR.
FRI...VFR.
SAT-SUN...SCT PM TSRA IMPACTS POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...MARTIN/STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...CERU/RXR
AVIATION...LA CORTE/CERU/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
913 AM EDT WED JUL 4 2012
.SYNOPSIS...
HOT SUMMERTIME WEATHER CONDITIONS WILL PREVAIL ACROSS CENTRAL
PENNSYLVANIA INTO THE WEEKEND. THERE WILL BE A CHANCE FOR
AFTERNOON SHOWERS AND THUNDERSTORMS TODAY...FOLLOWED BY FAIR AND
DRY WEATHER FOR THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPATED PACKAGE AROUND 730 AM...AS FIRST BATCH OF SHOWERS
AND STORMS OUT OF THE FAR SE.
WILL CONTINUE TO MONITOR MCS OVER SOUTHERN ONTARIO...AND
UPDATE AS NEEDED. VERY UNSTABLE AIRMASS JUST TO THE
WEST OF OUR AREA.
EARLIER DISCUSSION BELOW.
SHOWERS AND ISOLD TSTMS WILL BE CONFINED TO THE SRN 1/3 OF THE
CWA EARLY THIS MORNING...AS SHORTWAVE TROF/VORTICITY AXIS
CONTINUES TO PUSH SEWD ACRS THE CENTRAL MTNS AND EXITS SE PA
SHORTLY AFTER 12Z. CONVECTIVE ELEMENTS...LKLY ELEVATED...LOCATED
ON THE SW FLANK OF THE VORT AXIS NEAR PITTSBURGH SHOULD CONTINUE
TO WEAKEN AS THEY MOVE SEWD INTO A MORE STABLE AIRMASS ALONG/EAST
OF THE LAUREL HIGHLANDS. SATL DATA SHOWS CLEARING TO THE NW OF
DUJ-ELM LINE WITH FOG DEVELOPING IN THE VALLEYS.
&&
.SHORT TERM / THURSDAY THROUGH 6 AM THURSDAY/...
WEAK SFC RIDGING AND HEIGHT RISES IN THE WAKE OF H5 TROF AXIS WILL
KEEP THINGS QUIET EARLY TODAY. HOWEVER ALL BETS ARE OFF FOR LATER
IN THE DAY...AS THE AREA REMAINS ON THE NERN FRINGE OF HOT CENTRAL
U.S. RIDGE WITHIN BELT OF NWLY FLOW ALOFT.
WITH A RATHER WEAK/NONDESCRIPT SFC PATTERN FCST TO BE IN PLACE
LACKING A TRUE FORCING/TRIGGERING MECHANISM FOR GENERATING
SUBSTANTIAL UPWARD VERTICAL MOTION...EXPECT ANY DIURNAL CONVECTIVE
ACTIVITY TO BE NON-FOCUSED AND DISORGANIZED...DRIVEN LARGELY BY
SMALL/SUBTLE VORTICITY MAXIMA ROTATING SEWD DOWN THE FRONT-SIDE OF
THE CENTRAL U.S. ANTICYCLONE. THE HI RES MDL DATA MAY BE PICKING
UP ON ONE OF THESE SMALL/SUBTLE SHORTWAVE IMPULSES WHICH APPEARS
TO HAVE INITIATED A CLUSTER OF TSTMS OVR THE THUMB OF LWR MI/LK
HURON. BOTH THE 3KM HRRR AND 4KM NAM SHOW THIS AREA OF CONVECTION
CROSSING LAKE ERIE AROUND MID MORNING AND ENTERING THE NW MTNS
AROUND 18Z.
GIVEN THE LOW CONFIDENCE FCST...BROAD-BRUSHED LOW TO MEDIUM CHC
POPS FOR THE AFTN/EVE HOURS. CVRG SHOULD BE ISOLD TO SCT GIVEN
WEAK FORCING AND MOIST/UNSTABLE CONDITIONS. SPC HAS MAINTAINED THE
SEE TEXT CATG D1 OUTLOOK WITH LOW-PROBABILITY OF SVR.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
BY THU...RIDGE FLATTENS AND BEGINS TO EXTEND FURTHER EASTWARD
INTO CENTRAL PA. THOUGH AN ISOLATED LATE AFTERNOON/EVE TSTM WILL
BE POSS OFF THE HIGHER TERRAIN IN THE SW...WARMING TEMPS ALOFT
SHOULD KEEP THESE TO A MINIMUM. WITH PLENTY OF SUNSHINE...TEMPS
WILL RISE TO THE LOW TO MID 90S. MORE HOT WEATHER IN STORE FOR FRI
AND SAT...WITH READINGS 10-15F ABOVE NORMAL /AND HEAT INDICES
APPROACHING 100F IN THE SE/. HEAT HEADLINES MAY BE A POSSIBILITY
IF DEWPOINTS INCH CLOSER TO 70F...BUT DEEPEST LOW LEVEL MOISTURE
WILL REMAIN OFF TO OUR WEST. FRIDAY IS THE DRIEST OF THE THREE
DAYS...WITH HIGHER DEWPOINT AMOUNTS THURSDAY AND SATURDAY. NIGHTS
WILL CONTINUE TO BE QUITE MUGGY AND WARM ACROSS THE SOUTH.
OVER THE WEEKEND...HIGH PRESSURE RIDGE IS MOVED WESTWARD BY AN
STRONG UPPER LEVEL LOW MOVING THROUGH CENTRAL CANADA. THIS WILL
BRING A MID LEVEL TROUGH TO SLOWLY SAG OVER THE REGION LATE
SATURDAY INTO SUNDAY. THIS WILL PUSH A COOL FRONT THROUGH THE
REGION FROM THE NORTH...WHICH WILL BRING RENEWED CHANCES FOR TSTMS
INITIALLY ACROSS THE NORTH LATE SATURDAY...AND THEN ACROSS PA
LAT SATURDAY NIGHT...EARLY SUNDAY. DRY COOLER AIR BEHIND THE FRONT
WILL GRADUALLY WORK IN LATE IN THE WEEKEND AND THROUGH EARLY NEXT
WEEK. THIS SHOULD BRING RELIEF FROM THE SUMMERTIME HEAT...DROPPING
TEMPS BACK TOWARD SEASONAL NORMALS THROUGH THE FIRST HALF OF NEXT
WEEK.
&&
.AVIATION /13Z WEDNESDAY THROUGH SUNDAY/...
UPATED A FEW TAFS SO FAR. LOWER CLDS SLOW TO BREAK UP TO
THE NORTH.
ALSO DECIDED TO BRING SHOWERS INTO BFD A FEW HOURS SOONER...
LOOKS LIKE EAST SIDE OF CONVECTIVE COMPLEX OVER SOUTHERN
ONTARIO COULD BRUSH BFD WITH AT LEAST A FEW SHOWERS.
EARLIER DISCSSION BELOW.
SCATTERED TSRA AND SHRA CONTINUE ACROSS THE FAR SOUTHERN TIER OF
PA THIS MORNING. LIGHT RAIN CONTINUES AT MDT AND LNS...THROUGH
THESE SHOWERS SHOULD ARE NOG REDUCING CONDITIONS AND SHOW END BY
12Z.
LOW CLOUDS HAVE FORMED OVER BFD...WITH LIFR CIGS. THESE CONDITIONS
SHOULD LIFT BETWEEN 12-14Z. LIGHT VALLEY FOG REMAINS POSSIBLE
UNTIL AROUND 15Z.
STORMS SHOULD REGENERATE MID TO LATE THIS AFTERNOON WITH WARM
TEMPERATURES AND HIGH DEWPOINTS. SHORT RANGE MODELS SUGGEST
ACTIVITY MOVES THROUGH LATE AFTERNOON...EARLY EVENING.
OUTLOOK...
THUR...AM FOG OTHERWISE VFR.
FRI...VFR.
SAT-SUN...SCT PM TSRA IMPACTS POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...MARTIN/STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...CERU/RXR
AVIATION...LA CORTE/CERU/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
604 AM EDT WED JUL 4 2012
.SYNOPSIS...
HOT SUMMERTIME WEATHER CONDITIONS WILL PREVAIL ACROSS CENTRAL
PENNSYLVANIA INTO THE WEEKEND. THERE WILL BE A CHANCE FOR
AFTERNOON SHOWERS AND THUNDERSTORMS TODAY...FOLLOWED BY FAIR AND
DRY WEATHER FOR THURSDAY AND FRIDAY.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
SHOWERS AND ISOLD TSTMS WILL BE CONFINED TO THE SRN 1/3 OF THE CWA
EARLY THIS MORNING...AS SHORTWAVE TROF/VORTICITY AXIS CONTINUES TO
PUSH SEWD ACRS THE CENTRAL MTNS AND EXITS SE PA SHORTLY AFTER 12Z.
CONVECTIVE ELEMENTS...LKLY ELEVATED...LOCATED ON THE SW FLANK OF
THE VORT AXIS NEAR PITTSBURGH SHOULD CONTINUE TO WEAKEN AS THEY
MOVE SEWD INTO A MORE STABLE AIRMASS ALONG/EAST OF THE LAUREL
HIGHLANDS. SATL DATA SHOWS CLEARING TO THE NW OF DUJ-ELM LINE WITH
FOG DEVELOPING IN THE VALLEYS.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 AM THURSDAY/...
WEAK SFC RIDGING AND HEIGHT RISES IN THE WAKE OF H5 TROF AXIS WILL
KEEP THINGS QUIET EARLY TODAY. HOWEVER ALL BETS ARE OFF FOR LATER
IN THE DAY...AS THE AREA REMAINS ON THE NERN FRINGE OF HOT CENTRAL
U.S. RIDGE WITHIN BELT OF NWLY FLOW ALOFT.
WITH A RATHER WEAK/NONDESCRIPT SFC PATTERN FCST TO BE IN PLACE
LACKING A TRUE FORCING/TRIGGERING MECHANISM FOR GENERATING
SUBSTANTIAL UPWARD VERTICAL MOTION...EXPECT ANY DIURNAL CONVECTIVE
ACTIVITY TO BE NON-FOCUSED AND DISORGANIZED...DRIVEN LARGELY BY
SMALL/SUBTLE VORTICITY MAXIMA ROTATING SEWD DOWN THE FRONT-SIDE OF
THE CENTRAL U.S. ANTICYCLONE. THE HI RES MDL DATA MAY BE PICKING
UP ON ONE OF THESE SMALL/SUBTLE SHORTWAVE IMPULSES WHICH APPEARS
TO HAVE INITIATED A CLUSTER OF TSTMS OVR THE THUMB OF LWR MI/LK
HURON. BOTH THE 3KM HRRR AND 4KM NAM SHOW THIS AREA OF CONVECTION
CROSSING LAKE ERIE AROUND MID MORNING AND ENTERING THE NW MTNS
AROUND 18Z.
GIVEN THE LOW CONFIDENCE FCST...BROAD-BRUSHED LOW TO MEDIUM CHC
POPS FOR THE AFTN/EVE HOURS. CVRG SHOULD BE ISOLD TO SCT GIVEN
WEAK FORCING AND MOIST/UNSTABLE CONDITIONS. SPC HAS MAINTAINED THE
SEE TEXT CATG D1 OUTLOOK WITH LOW-PROBABILITY OF SVR.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
BY THU...RIDGE FLATTENS AND BEGINS TO EXTEND FURTHER EASTWARD
INTO CENTRAL PA. THOUGH AN ISOLATED LATE AFTERNOON/EVE TSTM WILL
BE POSS OFF THE HIGHER TERRAIN IN THE SW...WARMING TEMPS ALOFT
SHOULD KEEP THESE TO A MINIMUM. WITH PLENTY OF SUNSHINE...TEMPS
WILL RISE TO THE LOW TO MID 90S. MORE HOT WEATHER IN STORE FOR FRI
AND SAT...WITH READINGS 10-15F ABOVE NORMAL /AND HEAT INDICES
APPROACHING 100F IN THE SE/. HEAT HEADLINES MAY BE A POSSIBILITY
IF DEWPOINTS INCH CLOSER TO 70F...BUT DEEPEST LOW LEVEL MOISTURE
WILL REMAIN OFF TO OUR WEST. FRIDAY IS THE DRIEST OF THE THREE
DAYS...WITH HIGHER DEWPOINT AMOUNTS THURSDAY AND SATURDAY. NIGHTS
WILL CONTINUE TO BE QUITE MUGGY AND WARM ACROSS THE SOUTH.
OVER THE WEEKEND...HIGH PRESSURE RIDGE IS MOVED WESTWARD BY AN
STRONG UPPER LEVEL LOW MOVING THROUGH CENTRAL CANADA. THIS WILL
BRING A MID LEVEL TROUGH TO SLOWLY SAG OVER THE REGION LATE
SATURDAY INTO SUNDAY. THIS WILL PUSH A COOL FRONT THROUGH THE
REGION FROM THE NORTH...WHICH WILL BRING RENEWED CHANCES FOR TSTMS
INITIALLY ACROSS THE NORTH LATE SATURDAY...AND THEN ACROSS PA
LAT SATURDAY NIGHT...EARLY SUNDAY. DRY COOLER AIR BEHIND THE FRONT WILL
GRADUALLY WORK IN LATE IN THE WEEKEND AND THROUGH EARLY NEXT
WEEK. THIS SHOULD BRING RELIEF FROM THE SUMMERTIME
HEAT...DROPPING TEMPS BACK TOWARD SEASONAL NORMALS THROUGH THE
FIRST HALF OF NEXT WEEK.
&&
.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
SCATTERED TSRA AND SHRA CONTINUE ACROSS THE FAR SOUTHERN TIER OF
PA THIS MORNING. LIGHT RAIN CONTINUES AT MDT AND LNS...THROUGH
THESE SHOWERS SHOULD ARE NOG REDUCING CONDITIONS AND SHOW END BY
12Z.
LOW CLOUDS HAVE FORMED OVER BFD...WITH LIFR CIGS. THESE CONDITIONS
SHOULD LIFT BETWEEN 12-14Z. LIGHT VALLEY FOG REMAINS POSSIBLE
UNTIL AROUND 15Z.
STORMS SHOULD REGENERATE MID TO LATE THIS AFTERNOON WITH WARM
TEMPERATURES AND HIGH DEWPOINTS. SHORT RANGE MODELS SUGGEST ACTIVITY MOVES
THROUGH LATE AFTERNOON...EARLY EVENING.
OUTLOOK...
THUR...AM FOG OTHERWISE VFR.
FRI...VFR.
SAT-SUN...SCT PM TSRA IMPACTS POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...CERU/RXR
AVIATION...LA CORTE/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
443 AM EDT WED JUL 4 2012
.SYNOPSIS...
HOT SUMMERTIME WEATHER CONDITIONS WILL PREVAIL ACROSS CENTRAL
PENNSYLVANIA INTO THE WEEKEND. THERE WILL BE A CHANCE FOR
AFTERNOON SHOWERS AND THUNDERSTORMS TODAY...FOLLOWED BY FAIR AND
DRY WEATHER FOR THURSDAY AND FRIDAY.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
SHOWERS AND ISOLD TSTMS WILL BE CONFINED TO THE SRN 1/3 OF THE CWA
EARLY THIS MORNING...AS SHORTWAVE TROF/VORTICITY AXIS CONTINUES TO
PUSH SEWD ACRS THE CENTRAL MTNS AND EXITS SE PA SHORTLY AFTER 12Z.
CONVECTIVE ELEMENTS...LKLY ELEVATED...LOCATED ON THE SW FLANK OF
THE VORT AXIS NEAR PITTSBURGH SHOULD CONTINUE TO WEAKEN AS THEY
MOVE SEWD INTO A MORE STABLE AIRMASS ALONG/EAST OF THE LAUREL
HIGHLANDS. SATL DATA SHOWS CLEARING TO THE NW OF DUJ-ELM LINE WITH
FOG DEVELOPING IN THE VALLEYS.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH TONIGHT/...
WEAK SFC RIDGING AND HEIGHT RISES IN THE WAKE OF H5 TROF AXIS WILL
KEEP THINGS QUIET EARLY TODAY. HOWEVER ALL BETS ARE OFF FOR LATER
IN THE DAY...AS THE AREA REMAINS ON THE NERN FRINGE OF HOT CENTRAL
U.S. RIDGE WITHIN BELT OF NWLY FLOW ALOFT.
WITH A RATHER WEAK/NONDESCRIPT SFC PATTERN FCST TO BE IN PLACE
LACKING A TRUE FORCING/TRIGGERING MECHANISM FOR GENERATING
SUBSTANTIAL UPWARD VERTICAL MOTION...EXPECT ANY DIURNAL CONVECTIVE
ACTIVITY TO BE NON-FOCUSED AND DISORGANIZED...DRIVEN LARGELY BY
SMALL/SUBTLE VORTICITY MAXIMA ROTATING SEWD DOWN THE FRONT-SIDE OF
THE CENTRAL U.S. ANTICYCLONE. THE HI RES MDL DATA MAY BE PICKING
UP ON ONE OF THESE SMALL/SUBTLE SHORTWAVE IMPULSES WHICH APPEARS
TO HAVE INITIATED A CLUSTER OF TSTMS OVR THE THUMB OF LWR MI/LK
HURON. BOTH THE 3KM HRRR AND 4KM NAM SHOW THIS AREA OF CONVECTION
CROSSING LAKE ERIE AROUND MID MORNING AND ENTERING THE NW MTNS
AROUND 18Z.
GIVEN THE LOW CONFIDENCE FCST...BROAD-BRUSHED LOW TO MEDIUM CHC
POPS FOR THE AFTN/EVE HOURS. CVRG SHOULD BE ISOLD TO SCT GIVEN
WEAK FORCING AND MOIST/UNSTABLE CONDITIONS. SPC HAS MAINTAINED THE
SEE TEXT CATG D1 OUTLOOK WITH LOW-PROBABILITY OF SVR.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
BY THU...RIDGE FLATTENS AND BEGINS TO EXTEND FURTHER EASTWARD
INTO CENTRAL PA. THOUGH AN ISOLATED LATE AFTERNOON/EVE TSTM WILL
BE POSS OFF THE HIGHER TERRAIN IN THE SW...WARMING TEMPS ALOFT
SHOULD KEEP THESE TO A MINIMUM. WITH PLENTY OF SUNSHINE...TEMPS
WILL RISE INTO THE MID 80S TO MID 90S. MORE HOT WEATHER IN STORE
FOR FRI AND SAT...WITH READINGS 10-15F ABOVE NORMAL /AND HEAT
INDICES APPROACHING 100F IN THE SE/. HEAT HEADLINES MAY BE A
POSSIBILITY IF DEWPOINTS INCH CLOSER TO 70F...BUT DEEPEST LOW
LEVEL MOISTURE WILL REMAIN OFF TO OUR WEST. NIGHTS WILL CONTINUE
TO BE QUITE MUGGY AND WARM ACROSS THE SOUTH.
OVER THE WEEKEND...HIGH PRESSURE RIDGE RETROGRADES WESTWARD INTO
THE PLAINS...ALLOWING MID LEVEL TROUGH TO SLOWLY SAG OVER THE
REGION LATE SATURDAY INTO SUNDAY. THIS WILL PUSH A COOL FRONT
THROUGH THE REGION FROM THE NORTH...WHICH WILL BRING RENEWED
CHANCES FOR TSTMS INITIALLY ACROSS THE NORTH LATE SATURDAY...AND
THEN ACROSS PA EARLY SUNDAY. DRY COOLER AIR BEHIND THE FRONT
WILL GRADUALLY WORK IN FROM LATE WEEKEND THROUGH EARLY NEXT
WEEK...BRINGING RELIEF FROM THE SUMMERTIME HEAT...DROPPING TEMPS
BACK TOWARD SEASONAL NORMALS FOR NEXT WEEK.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
CONVECTION CONTINUES ITS MARCH EASTWARD AS A LINE OF SHOWERS AND
STORMS...EXTENDING SOUTH OF IPT AND STRETCHING SOUTH TO
CHAMBERSBURG WILL MOVE THROUGH HARRISBURG FROM 06 TO 07Z...AND
REACHING LNS BY 07Z.
EXPECT SCATTERED TSRA AND SHRA WILL MOVE ACROSS ALL THE SOUTHERN TAF
SITES...ESPECIALLY JST...AOO...MDT AND LNS. IFR CONDITIONS AT JST
AND AOO ARE POSSIBLE IN AND AROUND THUNDERSTORMS THROUGH 09Z. MVFR
CIGS AND VSBYS ARE POSSIBLE AT MDT AND LNS.
ONCE THESE STORMS PASS...LOW CLOUDS ARE POSSIBLE IN KBFD...WITH
IFR CIGS POSSIBLE THROUGH 12Z. MOST LOCATIONS SHOULD JUST SEE SOME MVFR
FOG FROM RESIDUAL MOISTURE...LIGHT WINDS AND A DECOUPLED
ATMOSPHERE.
STORMS SHOULD REGENERATE IN THE AFTERNOON TOMORROW AS THE AIRMASS
WILL BE VIRTUALLY THE SAME AS TODAY...EVEN MORE MUGGY. SHORT
RANGE MODELS SUGGEST ACTIVITY MOVES THROUGH LATE AFTERNOON...POSSIBLY
LEAVING 4TH OF JULY FIREWORKS UNTOUCHED BY INCLEMENT WEATHER.
OUTLOOK...
THU...AM FOG POSS W MTNS. OTHERWISE VFR.
FRI...VFR.
SAT-SUN...SCT PM TSRA IMPACTS POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...RXR
AVIATION...LA CORTE/CERU
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
821 PM CDT THU JUL 5 2012
.UPDATE...
NOT PLANNING ON ANY MAJOR CHANGES TO THE FORECAST THIS EVENING.
LATEST RUNS OF THE 3KM HRRR STILL MAINTAIN THAT AN MCS WILL ROLL
ACROSS THE NORTHWEST AND FAR NORTHERN CWA OVERNIGHT INTO FRIDAY
MORNING. DONT HAVE A REAL PROBLEM WITH THIS AS ITS CONSISTENT WITH
OTHER LOWER RESOLUTION MODEL DATA. THEREFORE WILL MAINTAIN HIGH
POPS OVERNIGHT. TEMPERATURES LOOK FINE FOR NOW.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TONIGHT THROUGH SUNDAY MORNING.
MAIN FCST CHALLENGE FACING THE NEAR TERM REVOLVES AROUND PCPN CHCS
FOR TONIGHT THROUGH FRIDAY MORNING.
LATEST 88D IMAGERY SHOWS EXPANDING AREA OF LIGHT -SHRA FROM MURDO
TO PLANKINTON...WITH NEW ACTIVITY NEAR HIGHMORE AND WATERTOWN.
AREA COINCIDES WITH MOISTURE RETURNING NORTHWARD COUPLED WITH
INCREASING FORCING NOTED ON THE 310K AND 315K ISENTROPIC LAYERS.
ISEN ANALYSIS ALSO REFLECTED POCKET OF DRIER AIR ACROSS NERN
SD...EVIDENCED BY DEWPTS ALONG THE HIGHWAY 12 CORRIDOR FROM MBG TO
K8D3 REMAINING IN THE MID 40S TO NEAR 50. CONVERSELY DWPTS IN THE
KHON AND KBKX AREA ARE IN THE MID 70S. HRRR MODEL AND LOCAL 4KM WRF
MODEL ALL SHOW THIS ACTIVITY SLIDING EAST ALONG THE HIGHWAYS 14
AND 212 CORRIDORS...WITH NOT MUCH MOVING NORTHWARD INTO DRIER AIR
IN PLACE ACROSS THE NORTHEAST.
ATTENTION THEN TURNS TOWARD THE OVERNIGHT PERIOD...AS LOW PRESSURE
DEVELOPS ACROSS EASTERN WY AND MOVING TO THE KPIR AREA BY 12Z
FRIDAY. WAA AHEAD OF DEVELOPING LOW PUSHES 700HPA TEMPS TO ABOVE
12C ACROSS MUCH OF THE EASTERN CWA. 850HPA 30KT TO 40KT JET LIFTS
WARM FRONT INTO SRN ND...AND MAJORITY OF MODELS SHOW ND WILL
RECEIVE BULK OF PCPN WITH THIS SYSTEM. AM HESITANT TO MENTION SVR
ATTM AS INCREDIBLY HIGH FREEZING LEVELS EXIST ACROSS CWA. ALTHOUGH
DRIER MID LEVELS COULD LEAD TO MORE OF A WIND THREAT.
BY FRIDAY AFTERNOON...LOW SAGS BACK TO THE SE...WITH WEAK CAA
FILLING IN ACROSS THE CWA. SOME LINGERING -SHRA/-TSRA COULD EXIST
DURING THE DAY ACROSS THE EASTERN CWA...BUT AGAIN BULK OF PCPN
APPEARS TO RESIDE IN ND AND WESTERN MN.
REMAINDER OF SHORT TERM LOOKS TO BE QUIET AND RELATIVELY COOL
(WHEN COMPARED TO PREVIOUS HIGHS) AS 850HPA TEMPS FALL BACK INTO
THE TEENS FOR THE WEEKEND.
.LONG TERM...SUNDAY THROUGH THURSDAY
A STRONG UPPER LEVEL RIDGE IS THE MAIN WEATHER FEATURE DURING THE
EXTENDED PERIOD. MODELS SHOW THIS RIDGE SETTING UP ACROSS THE
ROCKIES/HIGH PLAINS WITH NOT MUCH IN THE WAY OF RAINFALL CHANCES
OVER THE NORTHERN PLAINS. EXTENDED PERIOD REMAINS DRY AT THIS
POINT WITH WARM TEMPERATURES PERSISTING. AT THE SURFACE...MODELS
ARE SHOWING A SURFACE HIGH SLOWLY SLIDING EAST-SOUTHEAST ACROSS
THE NORTHERN PLAINS AND INTO THE WESTERN GREAT LAKES. HIGH TEMPS
THROUGHOUT THE PERIOD LOOK TO BE IN THE 80S AND 90S...WITH THE
WARMER READINGS ACROSS WESTERN AND CENTRAL SOUTH DAKOTA.
&&
.AVIATION...
00Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
OVERALL VFR CONDITIONS ARE EXPECTED AT ALL TAF LOCATIONS THROUGH
THE NIGHT. HOWEVER STORMS WILL BE POSSIBLE...ESPECIALLY AT KMBG
AND KABR LATE TNT. ANY STORMS COULD DROP CONDITIONS INTO THE IFR
CATEGORY BOTH CIGS AND VSBYS. THE STORMS WILL LINGER INTO THE
MORNING HOURS ON FRIDAY AT KABR BEFORE MOVING OFF TO THE EAST.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...TDK
SHORT TERM...HINTZ
LONG TERM...TMT
AVIATION...TDK
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
629 PM CDT THU JUL 5 2012
.UPDATE...
THE AVIATION DISCUSSION HAS BEEN UPDATED FOR THE 00Z TAF ISSUANCE.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TONIGHT THROUGH SUNDAY MORNING.
MAIN FCST CHALLENGE FACING THE NEAR TERM REVOLVES AROUND PCPN CHCS
FOR TONIGHT THROUGH FRIDAY MORNING.
LATEST 88D IMAGERY SHOWS EXPANDING AREA OF LIGHT -SHRA FROM MURDO
TO PLANKINTON...WITH NEW ACTIVITY NEAR HIGHMORE AND WATERTOWN.
AREA COINCIDES WITH MOISTURE RETURNING NORTHWARD COUPLED WITH
INCREASING FORCING NOTED ON THE 310K AND 315K ISENTROPIC LAYERS.
ISEN ANALYSIS ALSO REFLECTED POCKET OF DRIER AIR ACROSS NERN
SD...EVIDENCED BY DEWPTS ALONG THE HIGHWAY 12 CORRIDOR FROM MBG TO
K8D3 REMAINING IN THE MID 40S TO NEAR 50. CONVERSELY DWPTS IN THE
KHON AND KBKX AREA ARE IN THE MID 70S. HRRR MODEL AND LOCAL 4KM WRF
MODEL ALL SHOW THIS ACTIVITY SLIDING EAST ALONG THE HIGHWAYS 14
AND 212 CORRIDORS...WITH NOT MUCH MOVING NORTHWARD INTO DRIER AIR
IN PLACE ACROSS THE NORTHEAST.
ATTENTION THEN TURNS TOWARD THE OVERNIGHT PERIOD...AS LOW PRESSURE
DEVELOPS ACROSS EASTERN WY AND MOVING TO THE KPIR AREA BY 12Z
FRIDAY. WAA AHEAD OF DEVELOPING LOW PUSHES 700HPA TEMPS TO ABOVE
12C ACROSS MUCH OF THE EASTERN CWA. 850HPA 30KT TO 40KT JET LIFTS
WARM FRONT INTO SRN ND...AND MAJORITY OF MODELS SHOW ND WILL
RECEIVE BULK OF PCPN WITH THIS SYSTEM. AM HESITANT TO MENTION SVR
ATTM AS INCREDIBLY HIGH FREEZING LEVELS EXIST ACROSS CWA. ALTHOUGH
DRIER MID LEVELS COULD LEAD TO MORE OF A WIND THREAT.
BY FRIDAY AFTERNOON...LOW SAGS BACK TO THE SE...WITH WEAK CAA
FILLING IN ACROSS THE CWA. SOME LINGERING -SHRA/-TSRA COULD EXIST
DURING THE DAY ACROSS THE EASTERN CWA...BUT AGAIN BULK OF PCPN
APPEARS TO RESIDE IN ND AND WESTERN MN.
REMAINDER OF SHORT TERM LOOKS TO BE QUIET AND RELATIVELY COOL
(WHEN COMPARED TO PREVIOUS HIGHS) AS 850HPA TEMPS FALL BACK INTO
THE TEENS FOR THE WEEKEND.
.LONG TERM...SUNDAY THROUGH THURSDAY
A STRONG UPPER LEVEL RIDGE IS THE MAIN WEATHER FEATURE DURING THE
EXTENDED PERIOD. MODELS SHOW THIS RIDGE SETTING UP ACROSS THE
ROCKIES/HIGH PLAINS WITH NOT MUCH IN THE WAY OF RAINFALL CHANCES
OVER THE NORTHERN PLAINS. EXTENDED PERIOD REMAINS DRY AT THIS
POINT WITH WARM TEMPERATURES PERSISTING. AT THE SURFACE...MODELS
ARE SHOWING A SURFACE HIGH SLOWLY SLIDING EAST-SOUTHEAST ACROSS
THE NORTHERN PLAINS AND INTO THE WESTERN GREAT LAKES. HIGH TEMPS
THROUGHOUT THE PERIOD LOOK TO BE IN THE 80S AND 90S...WITH THE
WARMER READINGS ACROSS WESTERN AND CENTRAL SOUTH DAKOTA.
&&
.AVIATION...
00Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
OVERALL VFR CONDITIONS ARE EXPECTED AT ALL TAF LOCATIONS THROUGH
THE NIGHT. HOWEVER STORMS WILL BE POSSIBLE...ESPECIALLY AT KMBG
AND KABR LATE TNT. ANY STORMS COULD DROP CONDITIONS INTO THE IFR
CATEGORY BOTH CIGS AND VSBYS. THE STORMS WILL LINGER INTO THE
MORNING HOURS ON FRIDAY AT KABR BEFORE MOVING OFF TO THE EAST.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...TDK
SHORT TERM...HINTZ
LONG TERM...TMT
AVIATION...TDK
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1232 PM CDT WED JUL 4 2012
.SHORT TERM...TODAY THROUGH FRIDAY
348 AM CDT WED JUL 4 2012
NEAR RECORD HEAT EXPECTED FROM TODAY THROUGH THURSDAY NIGHT...
AND DANGEROUS HEAT INDICES OF 105 TO 115 THROUGH FRIDAY EVENING.
AT 3 AM...THE RADARS ARE SHOWING SOME ECHOES FROM WILLMAR
MINNESOTA EAST TO RHINELANDER WISCONSIN. RED WING JUST REPORTED A
SPRINKLE OUT OF THIS CONVECTION. THIS IS THE ONLY REPORT OF
PRECIPITATION THAT WE HAVE SEEN SO FAR THIS MORNING. THESE ECHOES
ARE ASSOCIATED WITH SOME TROPICAL MOISTURE LOCATED AROUND 600 MB
WHICH WRAPPING AROUND THE WESTERN AND NORTHERN PERIPHERY OF THE
UPPER LEVEL HIGH. IN ADDITION...THE RAP SUGGESTS SOME ELEVATED
CAPE UP TO 700 J/KG. THIS MAY BE A BIT OVER DONE CONSIDERING THAT
THERE HAS NOT BEEN TOO MUCH UPSCALE DEVELOPMENT. THE HRRR...RAP...
AND ARW SHOW THAT THERE WILL BE A FEW SHOWERS ALONG AND NORTH OF
THE INTERSTATE 94 CORRIDOR THROUGH 04.15Z. AS A RESULT...KEPT A
20 PERCENT CHANCE OF SHOWERS AND THUNDERSTORMS FOR THESE AREAS.
FOR TODAY...THE MODELS CONTINUE TO SHOW THAT MUCH OF THE AREA WILL
BE LOCATED UNDER A 10 TO 14C CAP. THE GFS...ECMWF...AND GEM
CONTINUE TO SUGGEST THAT THE LAKE BREEZE MAY IMPINGE ON THE FRONT
LOCATED ACROSS CENTRAL WISCONSIN THIS AFTERNOON. THIS SAME
INDICATION HAS SHOWED UP OVER THE PAST 3 DAYS AND STILL HAVE NOT
SEEN ANY PRECIPITATION ACROSS THIS AREA...SO DECIDED TO GO DRY.
UNDER PARTLY TO MOSTLY SUNNY SKIES...WE WILL MIX UP TO 750 MB.
THE 850 MB TEMPERATURES IN THE ECMWF ARE OVER 2.5 STANDARD
DEVIATIONS...SO EXPECTING THE POTENTIAL FOR A FEW RECORD HIGH
TEMPERATURES.
ON THURSDAY AND THURSDAY NIGHT...THE MODELS SUGGEST THAT A COLD
FRONT WILL SINK SOUTHWARD INTO THE FORECAST AREA AS A SHORT WAVE
MOVES EAST THROUGH SOUTHERN CANADA. THE NAM/WRF MOVES THIS FRONT
AS FAR SOUTH AS THE MINNESOTA BORDER. MEANWHILE ECMWF SUGGESTS
THAT THIS FRONT WILL REMAIN JUST NORTH OF THE FORECAST AREA. LIKE
THE PAST COUPLE OF DAYS...THE MODELS DO NOT SHOW ANY FRONTOGENESIS
OR EVEN MOISTURE TRANSPORT INTO THE AREA. IN ADDITION...AT MANY
LEVELS THE LIGHT WINDS ARE ACTUALLY PARALLEL WITH THIS FRONT AND
THERE IS STILL A 10-12C CAP IN PLACE ALOFT...SO STILL NOT
CONVINCED THAT WE WILL SEE SOME PRECIPITATION DURING THESE TIME
PERIODS. AS A RESULT...ONLY WENT WITH A 20 PERCENT CHANCE OF
PRECIPITATION. WITH PARTLY TO MOSTLY SUNNY SKIES AND MIXING UP TO
750 MB...IT LOOKS LIKE IT WILL BE ANOTHER WARM DAY WITH
TEMPERATURES RUNNING FROM AROUND 100 TO 105. HEAT INDICES WILL
RANGE FROM 105 TO 115. THE 850 MB TEMPERATURES IN THE ECMWF ARE
ONCE AGAIN OVER 2.5 STANDARD DEVIATIONS...SO EXPECTING THE
POTENTIAL FOR A FEW RECORD HIGH TEMPERATURES TO BE SET.
ON FRIDAY...THE ECMWF CONTINUES TO SUGGEST THAT THE FRONT WILL BE
STILL NORTH OF THE FORECAST AREA. MEANWHILE THE OTHER MODELS
SUGGEST THAT THIS FRONT WILL BE A BIT FURTHER SOUTH. IT ALSO
SUGGESTS THAT UPPER LEVEL HIGH WILL SHIFT FURTHER NORTH TOO. SINCE
THE ECMWF HAS BEEN MUCH MORE CONSISTENT AND USUALLY DOES THE
BETTER FOR THIS TIME PERIOD...RAISED THE TEMPERATURES A BIT AND
ONLY WENT WITH A SMALL CHANCE OF PRECIPITATION NORTH OF AN AUSTIN
MINNESOTA TO NEILLSVILLE WISCONSIN. WITH LITTLE SHEAR...NOT
EXPECTING ANY OF THESE THUNDERSTORMS TO BECOME SEVERE.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
348 AM CDT WED JUL 4 2012
ON FRIDAY NIGHT...THE GEM...NAM/WRF...AND ECMWF SUGGESTS THAT THE
FRONT WILL REMAIN NORTH OF INTERSTATE 90. MEANWHILE THE GFS IS
MUCH FURTHER SOUTH. OVERALL...PREFER THE NORTHERN SOLUTIONS...SO
LOWERED THE PRECIPITATION SOUTH OF INTERSTATE 90 CORRIDOR AND
RAISED THE LOW TEMPERATURES A FEW DEGREES.
FROM SATURDAY INTO SUNDAY...THE COLD FRONT WILL MOVE SLOWLY SOUTH
ACROSS THE AREA. STILL NOT OVERLY IMPRESSED WITH THE MOISTURE
TRANSPORT OR FRONTOGENESIS ACROSS THE AREA...SO ONLY WENT WITH
30 AND 40 PRECIPITATION CHANCES.
IN THE WAKE OF THIS FRONT...HIGH PRESSURE BUILDS ACROSS THE
REGION. THIS HIGH WILL PROVIDE COOLER AND DRIER AIR FOR EARLY NEXT
WEEK.
&&
.AVIATION...THROUGH 18Z THURSDAY
1232 PM CDT WED JUL 4 2012
VFR CONDITIONS ARE EXPECTED AT THE TAF SITES THROUGH THE FORECAST
PERIOD. A WARM FRONT POSITIONED ACROSS NORTHERN MINNESOTA INTO
NORTHERN WISCONSIN WILL SLOWLY SAG SOUTH LATE TONIGHT. AN UPPER
LEVEL RIDGE WILL PROVIDE MOSTLY CLEAR SKIES AND VFR CONDITIONS AT
THE TAF SITE THROUGH EARLY THURSDAY MORNING. THE FRONT WILL BE THE
FOCUS FOR POSSIBLE SHOWER AND THUNDERSTORMS DEVELOPMENT THURSDAY
AFTERNOON AS IT PUSHES SOUTH TOWARD THE INTERSTATE 90 CORRIDOR. PLAN
ON SOUTH/SOUTHWEST WINDS AT 9 TO 12 KTS THROUGH EARLY THIS
EVENING. A FEW GUSTS TO AROUND 16 KTS ARE POSSIBLE AT KRST. LOOK
FOR THE WINDS TO DECREASE TO AROUND 6 KTS LATE THIS EVENING INTO
THE OVERNIGHT HOURS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
348 AM CDT WED JUL 4 2012
WI...EXCESSIVE HEAT WARNING UNTIL 10 PM CDT FRIDAY FOR WIZ017-029-
032>034-041>044-053>055-061.
MN...EXCESSIVE HEAT WARNING UNTIL 10 PM CDT FRIDAY FOR MNZ079-086>088-
094>096.
IA...EXCESSIVE HEAT WARNING UNTIL 10 PM CDT FRIDAY FOR IAZ008>011-018-
019-029-030.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
636 AM CDT WED JUL 4 2012
.SHORT TERM...TODAY THROUGH FRIDAY
348 AM CDT WED JUL 4 2012
NEAR RECORD HEAT EXPECTED FROM TODAY THROUGH THURSDAY NIGHT...
AND DANGEROUS HEAT INDICES OF 105 TO 115 THROUGH FRIDAY EVENING.
AT 3 AM...THE RADARS ARE SHOWING SOME ECHOES FROM WILLMAR
MINNESOTA EAST TO RHINELANDER WISCONSIN. RED WING JUST REPORTED A
SPRINKLE OUT OF THIS CONVECTION. THIS IS THE ONLY REPORT OF
PRECIPITATION THAT WE HAVE SEEN SO FAR THIS MORNING. THESE ECHOES
ARE ASSOCIATED WITH SOME TROPICAL MOISTURE LOCATED AROUND 600 MB
WHICH WRAPPING AROUND THE WESTERN AND NORTHERN PERIPHERY OF THE
UPPER LEVEL HIGH. IN ADDITION...THE RAP SUGGESTS SOME ELEVATED
CAPE UP TO 700 J/KG. THIS MAY BE A BIT OVER DONE CONSIDERING THAT
THERE HAS NOT BEEN TOO MUCH UPSCALE DEVELOPMENT. THE HRRR...RAP...
AND ARW SHOW THAT THERE WILL BE A FEW SHOWERS ALONG AND NORTH OF
THE INTERSTATE 94 CORRIDOR THROUGH 04.15Z. AS A RESULT...KEPT A
20 PERCENT CHANCE OF SHOWERS AND THUNDERSTORMS FOR THESE AREAS.
FOR TODAY...THE MODELS CONTINUE TO SHOW THAT MUCH OF THE AREA WILL
BE LOCATED UNDER A 10 TO 14C CAP. THE GFS...ECMWF...AND GEM
CONTINUE TO SUGGEST THAT THE LAKE BREEZE MAY IMPINGE ON THE FRONT
LOCATED ACROSS CENTRAL WISCONSIN THIS AFTERNOON. THIS SAME
INDICATION HAS SHOWED UP OVER THE PAST 3 DAYS AND STILL HAVE NOT
SEEN ANY PRECIPITATION ACROSS THIS AREA...SO DECIDED TO GO DRY.
UNDER PARTLY TO MOSTLY SUNNY SKIES...WE WILL MIX UP TO 750 MB.
THE 850 MB TEMPERATURES IN THE ECMWF ARE OVER 2.5 STANDARD
DEVIATIONS...SO EXPECTING THE POTENTIAL FOR A FEW RECORD HIGH
TEMPERATURES.
ON THURSDAY AND THURSDAY NIGHT...THE MODELS SUGGEST THAT A COLD
FRONT WILL SINK SOUTHWARD INTO THE FORECAST AREA AS A SHORT WAVE
MOVES EAST THROUGH SOUTHERN CANADA. THE NAM/WRF MOVES THIS FRONT
AS FAR SOUTH AS THE MINNESOTA BORDER. MEANWHILE ECMWF SUGGESTS
THAT THIS FRONT WILL REMAIN JUST NORTH OF THE FORECAST AREA. LIKE
THE PAST COUPLE OF DAYS...THE MODELS DO NOT SHOW ANY FRONTOGENESIS
OR EVEN MOISTURE TRANSPORT INTO THE AREA. IN ADDITION...AT MANY
LEVELS THE LIGHT WINDS ARE ACTUALLY PARALLEL WITH THIS FRONT AND
THERE IS STILL A 10-12C CAP IN PLACE ALOFT...SO STILL NOT
CONVINCED THAT WE WILL SEE SOME PRECIPITATION DURING THESE TIME
PERIODS. AS A RESULT...ONLY WENT WITH A 20 PERCENT CHANCE OF
PRECIPITATION. WITH PARTLY TO MOSTLY SUNNY SKIES AND MIXING UP TO
750 MB...IT LOOKS LIKE IT WILL BE ANOTHER WARM DAY WITH
TEMPERATURES RUNNING FROM AROUND 100 TO 105. HEAT INDICES WILL
RANGE FROM 105 TO 115. THE 850 MB TEMPERATURES IN THE ECMWF ARE
ONCE AGAIN OVER 2.5 STANDARD DEVIATIONS...SO EXPECTING THE
POTENTIAL FOR A FEW RECORD HIGH TEMPERATURES TO BE SET.
ON FRIDAY...THE ECMWF CONTINUES TO SUGGEST THAT THE FRONT WILL BE
STILL NORTH OF THE FORECAST AREA. MEANWHILE THE OTHER MODELS
SUGGEST THAT THIS FRONT WILL BE A BIT FURTHER SOUTH. IT ALSO
SUGGESTS THAT UPPER LEVEL HIGH WILL SHIFT FURTHER NORTH TOO. SINCE
THE ECMWF HAS BEEN MUCH MORE CONSISTENT AND USUALLY DOES THE
BETTER FOR THIS TIME PERIOD...RAISED THE TEMPERATURES A BIT AND
ONLY WENT WITH A SMALL CHANCE OF PRECIPITATION NORTH OF AN AUSTIN
MINNESOTA TO NEILLSVILLE WISCONSIN. WITH LITTLE SHEAR...NOT
EXPECTING ANY OF THESE THUNDERSTORMS TO BECOME SEVERE.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
348 AM CDT WED JUL 4 2012
ON FRIDAY NIGHT...THE GEM...NAM/WRF...AND ECMWF SUGGESTS THAT THE
FRONT WILL REMAIN NORTH OF INTERSTATE 90. MEANWHILE THE GFS IS
MUCH FURTHER SOUTH. OVERALL...PREFER THE NORTHERN SOLUTIONS...SO
LOWERED THE PRECIPITATION SOUTH OF INTERSTATE 90 CORRIDOR AND
RAISED THE LOW TEMPERATURES A FEW DEGREES.
FROM SATURDAY INTO SUNDAY...THE COLD FRONT WILL MOVE SLOWLY SOUTH
ACROSS THE AREA. STILL NOT OVERLY IMPRESSED WITH THE MOISTURE
TRANSPORT OR FRONTOGENESIS ACROSS THE AREA...SO ONLY WENT WITH
30 AND 40 PRECIPITATION CHANCES.
IN THE WAKE OF THIS FRONT...HIGH PRESSURE BUILDS ACROSS THE
REGION. THIS HIGH WILL PROVIDE COOLER AND DRIER AIR FOR EARLY NEXT
WEEK.
&&
.AVIATION...TODAY AND TONIGHT
636 AM CDT WED JUL 4 2012
A WARM FRONT SITS JUST NORTH OF BOTH TAF SITES AND IS FORECAST TO
REMAIN NORTH THROUGH TONIGHT. PLENTY OF DRY LOW TO MID LEVEL AIR
EXISTS SOUTH OF THIS FRONT WHICH SHOULD HELP KEEP CONDITIONS VFR.
ONLY CAVEAT IS HIGHER MOISTURE RIGHT AT THE SURFACE. THIS
MOISTURE/HAZE COULD BRING VISIBILITIES BRIEFLY DOWN TO MVFR
BEFORE 15Z OR LATE TONIGHT...BUT CONFIDENCE IS TOO LOW TO INCLUDE
THIS IN THE TAFS AT THIS TIME. OTHERWISE...A SOUTH TO SOUTHWEST
BREEZE OF 5 TO 10 KTS IS EXPECTED TO PERSIST THROUGH
TONIGHT...WITH THE STRONGEST WINDS DURING THE AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
348 AM CDT WED JUL 4 2012
WI...EXCESSIVE HEAT WARNING UNTIL 10 PM CDT FRIDAY FOR WIZ017-029-
032>034-041>044-053>055-061.
MN...EXCESSIVE HEAT WARNING UNTIL 10 PM CDT FRIDAY FOR MNZ079-086>088-
094>096.
IA...EXCESSIVE HEAT WARNING UNTIL 10 PM CDT FRIDAY FOR IAZ008>011-018-
019-029-030.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
349 AM CDT WED JUL 4 2012
.SHORT TERM...TODAY THROUGH FRIDAY
348 AM CDT WED JUL 4 2012
NEAR RECORD HEAT EXPECTED FROM TODAY THROUGH THURSDAY NIGHT...
AND DANGEROUS HEAT INDICES OF 105 TO 115 THROUGH FRIDAY EVENING.
AT 3 AM...THE RADARS ARE SHOWING SOME ECHOES FROM WILLMAR
MINNESOTA EAST TO RHINELANDER WISCONSIN. RED WING JUST REPORTED A
SPRINKLE OUT OF THIS CONVECTION. THIS IS THE ONLY REPORT OF
PRECIPITATION THAT WE HAVE SEEN SO FAR THIS MORNING. THESE ECHOES
ARE ASSOCIATED WITH SOME TROPICAL MOISTURE LOCATED AROUND 600 MB
WHICH WRAPPING AROUND THE WESTERN AND NORTHERN PERIPHERY OF THE
UPPER LEVEL HIGH. IN ADDITION...THE RAP SUGGESTS SOME ELEVATED
CAPE UP TO 700 J/KG. THIS MAY BE A BIT OVER DONE CONSIDERING THAT
THERE HAS NOT BEEN TOO MUCH UPSCALE DEVELOPMENT. THE HRRR...RAP...
AND ARW SHOW THAT THERE WILL BE A FEW SHOWERS ALONG AND NORTH OF
THE INTERSTATE 94 CORRIDOR THROUGH 04.15Z. AS A RESULT...KEPT A
20 PERCENT CHANCE OF SHOWERS AND THUNDERSTORMS FOR THESE AREAS.
FOR TODAY...THE MODELS CONTINUE TO SHOW THAT MUCH OF THE AREA WILL
BE LOCATED UNDER A 10 TO 14C CAP. THE GFS...ECMWF...AND GEM
CONTINUE TO SUGGEST THAT THE LAKE BREEZE MAY IMPINGE ON THE FRONT
LOCATED ACROSS CENTRAL WISCONSIN THIS AFTERNOON. THIS SAME
INDICATION HAS SHOWED UP OVER THE PAST 3 DAYS AND STILL HAVE NOT
SEEN ANY PRECIPITATION ACROSS THIS AREA...SO DECIDED TO GO DRY.
UNDER PARTLY TO MOSTLY SUNNY SKIES...WE WILL MIX UP TO 750 MB.
THE 850 MB TEMPERATURES IN THE ECMWF ARE OVER 2.5 STANDARD
DEVIATIONS...SO EXPECTING THE POTENTIAL FOR A FEW RECORD HIGH
TEMPERATURES.
ON THURSDAY AND THURSDAY NIGHT...THE MODELS SUGGEST THAT A COLD
FRONT WILL SINK SOUTHWARD INTO THE FORECAST AREA AS A SHORT WAVE
MOVES EAST THROUGH SOUTHERN CANADA. THE NAM/WRF MOVES THIS FRONT
AS FAR SOUTH AS THE MINNESOTA BORDER. MEANWHILE ECMWF SUGGESTS
THAT THIS FRONT WILL REMAIN JUST NORTH OF THE FORECAST AREA. LIKE
THE PAST COUPLE OF DAYS...THE MODELS DO NOT SHOW ANY FRONTOGENESIS
OR EVEN MOISTURE TRANSPORT INTO THE AREA. IN ADDITION...AT MANY
LEVELS THE LIGHT WINDS ARE ACTUALLY PARALLEL WITH THIS FRONT AND
THERE IS STILL A 10-12C CAP IN PLACE ALOFT...SO STILL NOT
CONVINCED THAT WE WILL SEE SOME PRECIPITATION DURING THESE TIME
PERIODS. AS A RESULT...ONLY WENT WITH A 20 PERCENT CHANCE OF
PRECIPITATION. WITH PARTLY TO MOSTLY SUNNY SKIES AND MIXING UP TO
750 MB...IT LOOKS LIKE IT WILL BE ANOTHER WARM DAY WITH
TEMPERATURES RUNNING FROM AROUND 100 TO 105. HEAT INDICES WILL
RANGE FROM 105 TO 115. THE 850 MB TEMPERATURES IN THE ECMWF ARE
ONCE AGAIN OVER 2.5 STANDARD DEVIATIONS...SO EXPECTING THE
POTENTIAL FOR A FEW RECORD HIGH TEMPERATURES TO BE SET.
ON FRIDAY...THE ECMWF CONTINUES TO SUGGEST THAT THE FRONT WILL BE
STILL NORTH OF THE FORECAST AREA. MEANWHILE THE OTHER MODELS
SUGGEST THAT THIS FRONT WILL BE A BIT FURTHER SOUTH. IT ALSO
SUGGESTS THAT UPPER LEVEL HIGH WILL SHIFT FURTHER NORTH TOO. SINCE
THE ECMWF HAS BEEN MUCH MORE CONSISTENT AND USUALLY DOES THE
BETTER FOR THIS TIME PERIOD...RAISED THE TEMPERATURES A BIT AND
ONLY WENT WITH A SMALL CHANCE OF PRECIPITATION NORTH OF AN AUSTIN
MINNESOTA TO NEILLSVILLE WISCONSIN. WITH LITTLE SHEAR...NOT
EXPECTING ANY OF THESE THUNDERSTORMS TO BECOME SEVERE.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
348 AM CDT WED JUL 4 2012
ON FRIDAY NIGHT...THE GEM...NAM/WRF...AND ECMWF SUGGESTS THAT THE
FRONT WILL REMAIN NORTH OF INTERSTATE 90. MEANWHILE THE GFS IS
MUCH FURTHER SOUTH. OVERALL...PREFER THE NORTHERN SOLUTIONS...SO
LOWERED THE PRECIPITATION SOUTH OF INTERSTATE 90 CORRIDOR AND
RAISED THE LOW TEMPERATURES A FEW DEGREES.
FROM SATURDAY INTO SUNDAY...THE COLD FRONT WILL MOVE SLOWLY SOUTH
ACROSS THE AREA. STILL NOT OVERLY IMPRESSED WITH THE MOISTURE
TRANSPORT OR FRONTOGENESIS ACROSS THE AREA...SO ONLY WENT WITH
30 AND 40 PRECIPITATION CHANCES.
IN THE WAKE OF THIS FRONT...HIGH PRESSURE BUILDS ACROSS THE
REGION. THIS HIGH WILL PROVIDE COOLER AND DRIER AIR FOR EARLY NEXT
WEEK.
&&
.AVIATION...THROUGH 06Z THURSDAY
1151 PM CDT TUE JUL 3 2012
SURFACE BOUNDARY REMAINS NORTH OF BOTH TAF SITES LATE THIS
EVENING. NO CONVECTION HAS DEVELOPED SO FAR ALONG THE BOUNDARY BUT
IR SATELLITE SHOWS AN AREA OF CLOUDS TRYING TO DEVELOP OVER
SOUTHWEST MINNESOTA. BOTH THE 04.00Z NAM AND 04.01Z HRRR LATCH ON
TO THIS AND DEVELOP SOME CONVECTION DURING THE OVERNIGHT. THE NAM
SUGGESTS THIS ACTIVITY...IF IT DEVELOPS...WOULD MOVE ALMOST
STRAIGHT EAST ALONG THE BOUNDARY WHILE THE HRRR TAKES IT OFF TO
THE NORTHEAST WITH THE MEAN UPPER LEVEL FLOW. STILL HAVE SERIOUS
DOUBTS ABOUT THIS DEVELOPMENT AS THE 04.00Z KABR SOUNDING WAS
PRETTY DRY ABOVE THE CAP. THE KMPX SOUNDING DID SHOW A LITTLE BIT
OF MOISTURE AROUND 600 MB BUT NOT ENOUGH TO SUPPORT MUCH MORE THAN
CLOUDS. THE DOWNSTREAM SOUNDING AT KOAX WAS VERY DRY SO NO
MOISTURE AVAILABLE TO ADVECT IN TO AID IN THE DEVELOPMENT. WILL
STAY WITH A DRY AND CLOUD FREE FORECAST THROUGH THE PERIOD WITH
VFR CONDITIONS. THE VISIBILITY AT KRST HAS BEEN GOING DOWN AND CAN
NOT RULE OUT THE POSSIBILITY OF SOME MVFR HAZE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
348 AM CDT WED JUL 4 2012
WI...EXCESSIVE HEAT WARNING UNTIL 10 PM CDT FRIDAY FOR WIZ017-029-
032>034-041>044-053>055-061.
MN...EXCESSIVE HEAT WARNING UNTIL 10 PM CDT FRIDAY FOR MNZ079-086>088-
094>096.
IA...EXCESSIVE HEAT WARNING UNTIL 10 PM CDT FRIDAY FOR IAZ008>011-018-
019-029-030.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...04
CLIMATE...BOYNE
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
332 AM CDT WED JUL 4 2012
ADDED ANOTHER ROW OF COUNTIES TO EXCESSIVE HEAT WARNING WITH THE 4
DAY IDEA OF HITTING 100 DEGREES HEAT INDEX. INCLUDED MILWAUKEE
COUNTY AS WELL. THEY WILL HAVE 48 HOURS OF EXCESSIVE HEAT CRITERIA
AND LINGERED INTO FRIDAY WITH QUALIFYING FOR THE 4 DAY 100 DEGREE
IDEA AS WELL.
TODAY-FORECAST CONFIDENCE MEDIUM
500 MB HIGH CENTERED OVER MISSOURI WILL CONTINUE TO DOMINATE THE
WEATHER IN SOUTHERN WISCONSIN. THIS HIGH IS EXPECTED TO
INTENSIFY...WITH HEIGHTS BUILDING ABOUT 40 METERS OVER THE FORECAST
AREA. NAM/ECMWF 925 MB TEMPS ARE SHOWN TO INCREASE TO ABOUT 31 TO
32C...SUGGESTING 2-4 DEGREES OF WARMING OVER YESTERDAY. SO SHOULD
SEE MORE ACTUAL TEMPERATURES ABOVE 100F AWAY FROM LAKE MICHIGAN.
DEWPOINTS ARE STARTING OFF IN THE LOWER 70S...BUT SHOULD MIX INTO
THE LOWER TO MIDDLE 60S DURING THE AFTERNOON GIVEN THE LACK OF SOIL
MOISTURE. EXCEPTION WILL BE FOND DU LAC AND SHEBOYGAN AREAS WHERE
RAINFALL HAS BEEN CLOSER TO NORMAL PAST FEW WEEKS.
ALTHOUGH CONFIDENCE IS HIGH IN TEMPERATURES IT REMAINS LOW ON
PRECIPITATION CHANCES. MOST OF THE LARGE SCALE AND MESOSCALE MODELS
INDICATE RIDGE RIMMING MCS ACTIVITY TODAY IN WISCONSIN. AS HAS BEEN
THE CASE LATELY...THE MOST VULNERABLE AREA IS EAST CENTRAL COUNTIES.
NEGATIVES ARE VERY WARM 850 AND 700 MB TEMPERATURES AROUND +24C AND
+13C RESPECTIVELY. POSITIVES INCLUDE ORIENTATION OF PRECIPITABLE
WATER AND INSTABILITY AXIS...WHICH CURRENTLY EXTENDS FROM NORTH
DAKOTA TO SOUTHERN WISCONSIN. ACTIVITY OVER SOUTHERN MINNESOTA AND
NORTHWEST WISCONSIN HAS STRUGGLED SO FAR. OF MORE INTEREST IS MCS
ALONG NORTH DAKOTA/MANITOBA BORDER...WHICH HRRR TURNS INTO A BOW
ECHO AND MOVES TOWARD NORTHEAST MINNESOTA AROUND MIDDAY HOURS.
SEEMS THIS WOULD STAY TO THE NORTH OF OUR AREA. GIVEN STALLED
BOUNDARY AND HIGH INSTABILITY FORCED TO KEEP SLIGHT CHANCE ACROSS
NORTHEAST HALF MAINLY THIS AFTERNOON.
TONIGHT-FORECAST CONFIDENCE MEDIUM
MOST OF THE LARGE SCALE GUIDANCE IS DRY TONIGHT. HOWEVER...THE
GUIDANCE DOES HAVE A WEAK SHORT WAVE CURRENTLY IN NEBRASKA ROUNDING
THE TOP OF THE RIDGE IN MN/IA THIS EVENING AND INTO WISCONSIN LATE
TONIGHT. THIS WOULD BE TAPPING PART OF THE RICH TROPICAL MOISTURE
PLUME EVIDENT IN WATER VAPOR IMAGERY FROM MEXICO INTO FOUR CORNERS
AND THEN TO NEBRASKA. AT THIS POINT WILL LEAVE ISOLATED EVENING
THUNDERSTORMS EAST AND KEEP IT DRY...BUT CERTAINLY NEED TO KEEP AN
EYE ON THIS FEATURE.
THURSDAY - CONFIDENCE...MEDIUM
UPPER RIDGE WITH 591DM CONTOUR EXPANDS FURTHER INTO WI WITH VERY HOT
CONDITIONS. 925 TEMPS FROM BOTH THE ECMWF AND NAM ARE 32-34C WHICH
SUGGESTS TRIPLE DIGIT TEMPS. TRENDED TOWARDS THE LOWER DEW POINT
SOLUTIONS WITH MIXING AND DRY BOUNDARY LAYER. WEAK TROUGH APPROACHES
AND WITH WEAK GRADIENT...WINDS WILL TURN ONSHORE BRINGING SOME
RELIEF TO LAKESHORE AREAS. HOWEVER WITH EXPECTED HEAT INDICES
COMBINED WITH PAST CONDITIONS WILL EXPAND WARNING A FEW MORE
COUNTIES BUT KEEP OZAUKEE AND SHEBOYGAN AT ADVISORY.
FRIDAY - CONFIDENCE...MEDIUM
MODELS SUGGEST 594DM VERY CLOSE TO SRN WI WITH A WEAK LOBE OF
VORTICITY. LOW LEVEL WIND REGIME BECOMES MORE NNE IN THE WAKE OF THE
WEAK TROUGH...HOWEVER PROGGED THERMAL ADVECTION IS FAIRLY WEAK AND
MOST PRONOUNCED IN THE NORTHERN CWA. WILL LEAVE HEAT HEADLINES IN
PLACE INTO THE EVENING HOURS THOUGH SOME TEMP DECREASE POSSIBLE IN
THE NORTHERN CWA AND CLOSER TO LAKE MICHIGAN.
FRIDAY NIGHT THROUGH SUNDAY NIGHT - CONFIDENCE...MEDIUM
UPPER RIDGE COLLAPSES THIS PERIOD WITH 500 MILLIBAR NORTHWEST FLOW
EVOLVING. UPPER JET CORE GRADUALLY BECOMES SITUATED SO THAT SRN WI
IS SITUATED WITHIN THE FAVORED RIGHT REAR QUADRANT. STEADY 925/850
MILLIBAR COOL ADVECTION WITH CORE OF HOT AIRMASS SHIFTING TO THE
SOUTH OF WI. 850 MILLIBAR DEW POINT GRADIENT WITH WIND SHIFT LATER
SATURDAY INTO SUNDAY COMBINED WITH THE UPPER JET SUPPORT APPEARS TO
BE OUR BEST CHANCE FOR PRECIP DEVELOPMENT. SOME ELEVATED INSTABILITY
NOTED. GFS MOST ROBUST ON QPF WHILE ECMWF MUCH LESS IMPRESSIVE. WILL
HAVE CHANCY POPS FOR NOW PER ALLBLEND GUIDANCE.
MONDAY AND TUESDAY - CONFIDENCE...MEDIUM
QUIET AND RATHER REFRESHING PERIOD WITH HIGH PRESSURE BUILDING IN.
&&
.AVIATION/12Z TAFS/...VFR CONDITIONS AND LIGHT WINDS ARE MOST LIKELY
SCENARIO WITH HIGH HEAT/HUMIDITY COMBINING FOR ABNORMALLY HIGH
DENSITY ALTITUDES. VERY UNSTABLE AIRMASS WITH WEAK STALLED FRONT
IN AREA AND NORTHWEST FLOW COULD CERTAINLY RESULT IN CLUSTERS OF
THUNDERSTORMS PUSHING THROUGH...MAINLY OVER EAST CENTRAL WISCONSIN
AND TO THE NORTH OF THE TAF SITES.
FOR NOW WILL KEEP THUNDERSTORMS OUT OF THE TAFS AS PROBABILITY TOO
LOW TO JUSTIFY.
WEAKER SOUTHWEST FLOW TODAY THAN YESTERDAY AND WILL ALLOW LAKE
BREEZE TO PUSH INTO SOUTHEAST WISCONSIN TAF SITES IN THE MID
AFTERNOON.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...EXCESSIVE HEAT WARNING UNTIL 10 PM CDT FRIDAY FOR WIZ046-047-051-
056>059-062>072.
HEAT ADVISORY UNTIL 10 PM CDT FRIDAY FOR WIZ052-060.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...CRAVEN
THURSDAY THROUGH TUESDAY...COLLAR
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1151 PM CDT TUE JUL 3 2012
.SHORT TERM...THROUGH FRIDAY
330 PM CDT TUE JUL 3 2012
FORECAST PROBLEMS DURING THE PERIOD FOCUSED ON HEAT AND HOW
WARM...AS WELL AS RAIN CHANCES. ONGOING FORECAST WAS NOT CHANGED
TOO MUCH. LACK OF FORCING LENDS ITSELF TO LOW CONFIDENCE ON ANY
THUNDERSTORM CHANCES. CONFIDENCE REMAINS HIGH ON HEAT THROUGH
FRIDAY.
THIS AFTERNOON TEMPERATURES ARE STILL BATTLING FROM THE CLOUDY
START AND 100S SEEM A STRETCH AT THIS POINT. THIS SHOWS THAT WE
NEED A PRETTY CLEAN SKY FOR OUR HIGH TEMPERATURE FORECASTS THE
NEXT SEVERAL DAYS AND ANY CLOUDS OR RAIN WOULD IMPACT THOSE
NUMBERS. ANY BOUNDARIES FROM THE MORNING CONVECTION HAVE NOW BEEN
MIXED OUT AND BROAD LOW-LEVEL SOUTHWEST FLOW IS FOUND. 19Z SPC
MESOANALYSIS SHOWING SOME WEAK SURFACE CONVERGENCE NEAR I-90 IN
SWRN MN WITH MLCAPE AROUND 3000 J/KG. WHILE THIS SHOULD BE CAPPED
IN THE HEART OF THE WARM LAYER ALOFT...WILL JUST HAVE TO WATCH
THIS AREA. A LOW-LEVEL THERMAL GRADIENT /STATIONARY FRONT/ IS
STILL ORIENTED FROM KEAU-KMSN/KMKX SO THERE IS WEAK ISENTROPIC
LIFT THROUGH THAT AREA IN THE LOW-LEVELS. CURRENT THINKING IS THAT
ANY CONVECTION WILL BE EAST OF THE FORECAST AREA IN ERN WI.
MORNING RAOBS SHOW THE WARM AIR PROD AT 850MB POINTED RIGHT AT THE
FORECAST AREA WITH 25C AT OMAHA. THIS SEEMS TO BE A CLOSELY RELATED
TO 100F AT THE SURFACE WHEN MIXING WELL FOR IOWA /PER WFO DMX
HISTORICAL WORK THEY DID TODAY/. THIS WARM PROD...INCLUDING 31-34C
AIR AT 925 MB AND DEEP MIXING FORECAST BY THE 03.00Z AND 03.12Z
ECMWF AND 03.12Z NAM RUNS...SUGGEST 100F HIGH TEMPERATURES ARE ON
TARGET. RIVER VALLEYS WILL BE THE HOTTEST AREAS WITH DEEPER MIXING
AND SANDY SOILS. HAVE COME DOWN A BIT ON HIGHS WED/THU BUT NOT
MUCH. DEWPOINTS REMAIN NEARLY THE SAME AS PREVIOUS FORECAST AND
THUS HEAT WARNING IS ON TRACK. WEDNESDAY TEMPERATURES WILL WARM AS
PROD MOVES RIGHT OVER THE FORECAST AREA.
HOWEVER....HAVE MADE SOME CHANGES ON THE WEDNESDAY FORECAST NORTH
OF I-90 AS IT SEEMS A DESCENT SHORTWAVE TROUGH EJECTS FROM ROCKIES...
AND HIGH PLAINS CONVECTION OVER SD SHOULD WORK TO ENERGIZE THIS
WAVE AS IT HEADS TOWARD KDLH OVERNIGHT. THE WAVE AND INSTABILITY LATER
TONIGHT...AS WELL AS THE CAP ORIENTATION I-90 AND SOUTH...WILL ALLOW
NORTHERN TO CENTRAL WI TO BE OPEN FOR SOME POSSIBLE SHRA/TSRA
LATE. HAVE LOWERED HIGHS NORTH OF HIGHWAY 10 A BIT WEDNESDAY...AND
INCREASED RAIN CHANCES TO 30S. ARW WRF MODELS ALL SUGGEST THIS
COULD BE A BIT STRONGER COMPLEX /BUT NOT SEVERE/ THAN THE BROKEN
UP SYSTEM HI-RES NMM WRF RUNS SUGGEST. OVERALL...JUST INCREASED THE
WEATHER A BIT WEDNESDAY. AREAS ALONG AND SOUTH OF I-90 WILL STILL
BE HOT AND MAINLY CLEAR IT SEEMS. THURSDAY IS PROBABLY THE HOTTEST
DAY AS LIMITED FORCING SHOULD MEAN NEARLY CLEAR SKIES AND MAXIMUM
HEATING. LOW-LEVEL AIR IS 2-3 STANDARD DEVIATIONS ABOVE NORMAL
WED/THU...IN RECORD HIGH TERRITORY.
RAIN CHANCES WILL BEGIN TO INCREASE AS THE COLD FRONT SLOWLY MAKES
WAY SOUTHWARD BEGINNING FRIDAY. AREAS NORTH OF I-90...ESPECIALLY
NORTH OF HIGHWAY 10 IN WI...WILL LIKELY NOT BE IN HEAT WARNING
CRITERIA FRIDAY IF THE COOLER TREND CONTINUES. THEY WILL ALSO HAVE
RAIN CHANCES THERE. FRIDAY IS STILL VERY HOT ACROSS THE SOUTH
WITH NO AIR MASS CHANGE THERE UNTIL SATURDAY. WILL NOT MAKE
CHANGES TO THE HEAT WARNING FOR FRIDAY YET...WILL WAIT TO GET MORE
DETAILS ON THE FRONTAL TIMING.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
330 PM CDT TUE JUL 3 2012
THIS PERIOD STARTS HOT AND ENDS COMFORTABLE. THE LONGWAVE RIDGE
GIVES WAY TO NORTHWEST FLOW TROUGHING. THE FRONT WILL SLOWLY MOVE
SOUTH FRIDAY-SATURDAY WITH SOME INSTABILITY AND POST-FRONTAL RAIN
BANDING WHERE THE CAP FINALLY WEAKENS /BEHIND THE FRONT/...MEANING A
GOOD CHANCE FOR RAIN MOST AREAS. WOULD THINK THE RAIN CHANCES WILL
INCREASE FOR THE WEEKEND...BUT RIGHT NOW THE TIMING IS OF LOWER
CONFIDENCE. A BIT TOUGH TO DISCERN SEVERE CHANCES AT THIS TIME BUT
SOME SEVERE WEATHER CANNOT BE RULED OUT.
MOST OF SUNDAY-TUESDAY LOOK TO BE DRY AND NEAR NORMAL FOR
TEMPERATURES...A NICE BREAK FROM THE HEAT.
&&
.AVIATION...THROUGH 06Z THURSDAY
1151 PM CDT TUE JUL 3 2012
SURFACE BOUNDARY REMAINS NORTH OF BOTH TAF SITES LATE THIS
EVENING. NO CONVECTION HAS DEVELOPED SO FAR ALONG THE BOUNDARY BUT
IR SATELLITE SHOWS AN AREA OF CLOUDS TRYING TO DEVELOP OVER
SOUTHWEST MINNESOTA. BOTH THE 04.00Z NAM AND 04.01Z HRRR LATCH ON
TO THIS AND DEVELOP SOME CONVECTION DURING THE OVERNIGHT. THE NAM
SUGGESTS THIS ACTIVITY...IF IT DEVELOPS...WOULD MOVE ALMOST
STRAIGHT EAST ALONG THE BOUNDARY WHILE THE HRRR TAKES IT OFF TO
THE NORTHEAST WITH THE MEAN UPPER LEVEL FLOW. STILL HAVE SERIOUS
DOUBTS ABOUT THIS DEVELOPMENT AS THE 04.00Z KABR SOUNDING WAS
PRETTY DRY ABOVE THE CAP. THE KMPX SOUNDING DID SHOW A LITTLE BIT
OF MOISTURE AROUND 600 MB BUT NOT ENOUGH TO SUPPORT MUCH MORE THAN
CLOUDS. THE DOWNSTREAM SOUNDING AT KOAX WAS VERY DRY SO NO
MOISTURE AVAILABLE TO ADVECT IN TO AID IN THE DEVELOPMENT. WILL
STAY WITH A DRY AND CLOUD FREE FORECAST THROUGH THE PERIOD WITH
VFR CONDITIONS. THE VISIBILITY AT KRST HAS BEEN GOING DOWN AND CAN
NOT RULE OUT THE POSSIBILITY OF SOME MVFR HAZE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
330 PM CDT TUE JUL 3 2012
WI...EXCESSIVE HEAT WARNING UNTIL 10 PM CDT FRIDAY FOR WIZ017-029-
032>034-041>044-053>055-061.
MN...EXCESSIVE HEAT WARNING UNTIL 10 PM CDT FRIDAY FOR MNZ079-086>088-
094>096.
IA...EXCESSIVE HEAT WARNING UNTIL 10 PM CDT FRIDAY FOR IAZ008>011-018-
019-029-030.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...04
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1141 PM MDT THU JUL 5 2012
.AVIATION...TSRA JUST ABOUT OVER FOR TONIGHT...WITH SOME
CONVECTIVE DEBRIS CLOUDINESS LINGERING OVER THE MOUNTAINS THROUGH
SUNRISE. ON FRIDAY...NORTHERLY WINDS BEHIND A COLD FRONT WILL
AFFECT KCOS BETWEEN 12-15Z...AND KPUB BY 18Z. TSRA LIKELY AT KCOS
FRIDAY AFTERNOON AND EVENING...WITH CHANCE FOR STORMS AT KPUB AND
KALS AS WELL. AIR MASS BEHIND THE FRONT WILL BE MORE MOIST THAN
THE PAST FEW DAYS...SO EXPECT LOWER CIGS AND MORE WIDESPREAD
MOUNTAIN OBSCURATION WITH ANY TSRA FRI AFTERNOON AND
EVENING...ESPECIALLY PALMER DIVIDE AND PIKES PEAK REGION.
&&
.PREV DISCUSSION... /ISSUED 318 PM MDT THU JUL 5 2012/
SHORT TERM...
(TONIGHT AND FRIDAY)
SOUTHERLY WINDS HAVE INCREASED ACROSS THE PLAINS AND VALLEYS WITH
GUSTS TO AROUND 30 KTS ACROSS THE FAR EASTERN PLAINS. THIS
SOUTHERLY FETCH IS STILL TAPPING MODERATE DEW POINTS IN 50S TO THE
SOUTH OF THE REGION...SO IN SPITE OF THE MIXING...SFC DEW POINTS
HAVE REMAINED IN THE UPPER 40S AND 50S OUT EAST. SO FAR THIS HAS
KEPT RELATIVE HUMIDITIES ABOVE THE CRITICAL 15 PERCENT THRESHOLD FOR
FIRE WEATHER CONCERNS ACROSS THE PLAINS. POCKETS OF DRIER AIR HAVE MIXED
DOWN INTO THE LOWER ELEVATIONS WITH DEW POINTS IN THE 30S ACROSS THE
UPPER ARKANSAS RIVER VALLEY OF CHAFFEE AND LAKE COUNTIES AS WELL AS
THE WET MOUNTAIN VALLEY...WITH UPPER 30S AND 40S ALONG THE I-25
CORRIDOR AND CENTRAL AND EASTERN FREMONT COUNTIES.
MEANWHILE...EMBEDDED MONSOON MOISTURE PLUME EXTENDS ACROSS THE
WESTERN PORTIONS OF THE STATE WITH MOST APPARENT EMBEDDED
WAVE LIFTING NORTHWARD ACROSS UT. FOR THE REMAINDER OF
TONIGHT...EXPECT SCATTERED TO NUMEROUS THUNDERSTORMS OVER THE
MOUNTAINS...WITH GREATEST COVERAGE ALONG THE CONTINENTAL DIVIDE
WHERE PRECIP WATERS ARE RUNNING THE HIGHEST. LOCALLY HEAVY RAINFALL
WILL BE THE PRIMARY THREAT ALONG WITH LIGHTNING. GUSTY WINDS UP TO
40 MPH WILL BE POSSIBLE ACROSS THE VALLEYS. HRRR CONTINUES TO
DEVELOP HIGH BASED THUNDERSTORMS ALONG THE SFC TROF AXIS ACROSS SE
CO...SO HAVE NUDGED SOME ISOLATED POPS A TOUCH FARTHER EAST.
SOUNDINGS FROM THE I-25 CORRIDOR EASTWARD KEEP THUNDERSTORMS MORE
HIGH BASED WITH LCLS AROUND H6. HRRR DEVELOPS SOME ISOLATED TO
SCATTERED CONVECTION NEAR THE WALDO CANYON BURN SCAR BETWEEN 4-5 PM
WITH AROUND .25 INCH OF RAINFALL POSSIBLE SHOULD IT IMPACT THE BURN
SCAR. WITH SOUTHERLY FLOW AROUND 10-20 KTS THROUGH THE LAYER...STORM
MOTIONS SHOULD BE SUFFICIENT TO LIMIT THE THREAT FOR FLASH FLOODING
ON THE BURN SCAR...AND THESE MODEL PREDICTED AMOUNTS LOOK IN THE
BALL PARK. THUNDERSTORMS DIE OFF DIURNALLY FOR MOST AREAS...THOUGH WILL
HANG ON TO SOME ISOLATED -TSRA ACROSS WESTERN AREAS BENEATH THE
MONSOON PLUME.
ON FRIDAY...COLD FRONT WILL SHIFT SOUTHWARD INTO EL PASO COUNTY
DURING THE AFTERNOON...INCREASING PRECIPITABLE WATERS AS DEW POINTS
BEHIND THE BOUNDARY RISE INTO THE LOWER 50S. DEEPER MONSOON
MOISTURE PLUME RESIDES ACROSS THE CONTINENTAL DIVIDE...HOWEVER WITH
DEW POINTS ACROSS NORTHEAST CO CURRENTLY IN THE 50S...SEEMS REASONABLE THAT
LOW LEVEL MOISTURE WILL INCREASE MORE RAPIDLY BEHIND THE FRONT ON
FRIDAY...COMPARED TO THE SCENARIO THAT PLAYED ON WEDNESDAY. THIS
RAISES CONCERNS FOR FLASH FLOODING ON THE WALDO CANYON BURN SCAR AS
THE HIGHER MOISTURE CONTENT OF THE ATMOSPHERE SHOULD SUPPORT HEAVIER
RAINFALL RATES. WITH THE FRONT PROGGED TO LIE UP ACROSS THIS
REGION...THERE IS MORE LIKELY TO BE A FOCUS MECHANISM FOR
THUNDERSTORM GENERATION IN THIS AREA AS WELL...AND A FLASH FLOOD WATCH
MAY BE NEEDED IF FUTURE MODEL RUNS CONTINUE TO INDICATE SUFFICIENT
MOISTURE WILL BE AVAILABLE IMMEDIATELY BEHIND THE FRONT.
PROBABILITY LOOKS HIGHER FOR THIS TO OCCUR ON FRIDAY VERSUS
WEDNESDAY...BUT WOULD LIKE TO SEE THIS SCENARIO GET RESOLVED BY
HIGHER RESOLUTION SHORT RANGE MODELS (WRF...RUC13...HRRR) BEFORE
PULLING THE TRIGGER ON THE FLASH FLOOD WATCH. AS WE HAVE SEEN THE
PAST FEW DAYS...A LOT WILL DEPEND ON MESOSCALE FORECASTING...AND
WILL DEFER THIS DECISION TO LATER SHIFTS. HOWEVER...PEOPLE IN AND
NEAR THE WALDO CANYON BURN SCAR SHOULD MAINTAIN A HEIGHTENED
AWARENESS FOR THE POTENTIAL OF FLASH FLOODING AS WE TRANSITION INTO
MOISTER ENVIRONMENT AS THE WEEKEND APPROACHES.
ELSEWHERE...SCATTERED TO NUMEROUS THUNDERSTORMS CAN BE EXPECTED
ACROSS THE MOUNTAIN AREAS WITH MORE ISOLATED THUNDERSTORMS ACROSS
THE PLAINS TO THE SOUTH OF THE FRONT. HEAVY RAIN AND LIGHTNING WILL
BE THE PRIMARY STORM THREATS OVER THE MOUNTAINS...WITH MORE OF A
GUSTY WIND POTENTIAL ALONG WITH LIGHT TO MODERATE RAINFALL ACROSS
THE REMAINDER OF THE SOUTHEAST PLAINS. -KT
LONG TERM...
(FRIDAY NIGHT THROUGH THURSDAY)
..LOCALLY HEAVY RAINFALL POSSIBLE INTO EARLY NEXT WEEK...
FRIDAY NIGHT-SATURDAY NIGHT... FRIDAY NIGHT INTO EARLY SATURDAY WILL BE A
TRANSITION PERIOD OVER THE CWA. THE GFS/NAM12 ARE IN GOOD AGREEMENT
OF A SHORTWAVE PASSING NORTH OF THE FORECAST AREA FRIDAY NIGHT AND
DROPPING A COLD FRONT THROUGH EASTERN COLORADO BY 12Z SATURDAY
MORNING. BOTH MODELS ADVECT PLENTY OF MOISTURE INTO THE REGION
BEHIND THE FRONT...SHOWING DEWPOINTS OF MID 50S TO NEAR 60 BEHIND
THE FRONT BY 15Z SATURDAY. MODELS SHOW WEAK EASTERLY FLOW AND
WIDESPREAD SHOWERS AND THUNDERSTORMS OVER THE REGION BY 00Z SUNDAY. MODEL
QPF MAY BE A BIT OVERDONE AS A DISTINCT TRIGGER IS HARD TO IDENTIFY
GIVEN CURRENT MODEL DATA. HOWEVER...WITH PLENTY OF MOISTURE IN
PLACE...WEAK UPSLOPE FLOW...AND HARD TO TIME WEAK SHORTWAVES IN THE
FLOW PASSING OVERHEAD...CONVECTIVE INITIATION WILL BE POSSIBLE.
LOCALLY HEAVY RAIN WILL BE POSSIBLE AS UPPER LEVEL FLOW WILL BE WEAK
ACROSS THE REGION. 500MB WINDS ARE PROGGED TO BE...AT BEST...
5-10KTS SATURDAY AND SUNDAY AFTERNOON. HIGH RESOLUTION SHORT RANGE
MODELS WILL NEED TO BE EVALUATED FRIDAY NIGHT/EARLY SATURDAY
MORNING TO GET A MORE DETAILED PICTURE OF HOW MUCH PRECIPITATION
MAY FALL ACROSS THE REGION...ESPECIALLY IN AND AROUND THE WALDO
CANYON FIRE BURN SCAR.
BESIDES PRECIPITATION...ANOTHER SIGNIFICANT CHANGE WILL BE
TEMPERATURES RETURNING TO AVERAGE OR JUST BELOW AVERAGE LEVELS
ACROSS THE FORECAST AREA. MODELS LOWER 700MB TEMPERATURES FROM
RECENT 18-20C READINGS TO THE LOWER TEENS BEHIND THE FRONT FRIDAY
MORNING. 700MB TEMPERATURES WILL CONTINUE TO FALL THROUGH
SATURDAY...BOTTOMING OUT IN THE 8-10C RANGE SUNDAY. THE HIGHEST
TEMPERATURES CURRENTLY FORECAST FOR THE EASTERN PLAINS IS ONLY 87F
ACROSS THE EASTERN PLAINS ON SUNDAY...ENDING A LONG RUN OF 90-100+
TEMPERATURES IN THAT AREA.
SUNDAY AND MONDAY...
THE CENTER OF THE UPPER LEVEL HIGH PRESSURE THAT HAS BEEN CENTERED
OVER THE PLAINS THE PAST FEW DAYS WILL BEGIN TO RETROGRADE TOWARDS
THE FOUR CORNERS REGION SUNDAY MORNING WITH THE RIDGE AXIS BEING
CENTERED NEAR UTAH BY SUNDAY NIGHT. THIS WILL HELP MAINTAIN WEAK
STEERING CURRENTS ALOFT AND WEAK UPSLOPE FLOW ACROSS THE FORECAST
AREA. SCATTERED SHOWERS AND THUNDERSTORMS WILL AGAIN DEVELOP BY
LATE MORNING AND INCREASE IN COVERAGE THROUGHOUT THE AFTERNOON.
LOCALLY HEAVY RAINS WILL AGAIN BE POSSIBLE IN THE MOUNTAINS...I-25
CORRIDOR (INCLUDING THE WALDO CANYON BURN SCAR.)...AND THE EASTERN PLAINS.
TUESDAY-THURSDAY...
THE UPPER LEVEL HIGH TO THE NORTHWEST WILL PRODUCE WEAK
NORTHEASTERLY WINDS AT 500MB BEGINNING EARLY TUESDAY. THIS WILL
ADVECT SOME RELATIVELY DRIER AIR INTO EASTERN PARTS OF THE FORECAST
AREA. ENOUGH MOISTURE WILL REMAIN OVER THE HIGHER ELEVATIONS TO KEEP
AFTERNOON PULSE THUNDERSTORMS IN THE FORECAST THROUGH THURSDAY...BUT
COVERAGE SHOULD REMAIN LIMITED TO THE CENTRAL AND SOUTHWEST
MOUNTAINS WITH LITTLE TO NO PRECIPITATION EXPECTED OVER THE I-25
CORRIDOR OR EASTERN PLAINS. -PJC
AVIATION...
SOUTH TO SOUTHWEST WINDS WILL CONTINUE AT TAF SITES IN THE 12-24 KT
RANGE THROUGH 02-03Z. VFR CIGS AND GUSTIER WINDS UP TO 35 KTS WILL
BE POSSIBLE NEAR -TSRA THIS EVENING. MOST LIKELY TAF SITE TO GET
IMPACTED BY THUNDERSTORMS WILL BE AT KALS. WILL ALSO MAINTAIN VCTS
AT KCOS...THOUGH THIS LOOKS MOST LIKELY TO OCCUR AFTER 21-22Z.
THUNDERSTORMS WILL DECREASE AFTER 02Z. ON FRIDAY...NORTHERLY WINDS
BEHIND A COLD FRONT WILL AFFECT KCOS BETWEEN 09-12Z...AND AT KPUB BY
15Z. -TSRA WILL BE MORE LIKELY TO AFFECT THE KCOS TAF SITE FRIDAY
AFTERNOON BEHIND THE COLD FRONT AS WINDS SHIFT AROUND FROM THE
NORTHEAST TO EAST. VFR TO BRIEF MVFR CIGS...WITH LOCALLY HEAVY RAINFALL
WILL BE POSSIBLE. KALS WILL ALSO SEE THE POTENTIAL FOR
THUNDERSTORMS FRIDAY AFTERNOON...THOUGH WINDS LOOK LIGHTER IN THE
10-15 KT RANGE. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
10/44
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
243 AM EDT FRI JUL 6 2012
.PREV DISCUSSION... /ISSUED 1056 PM EDT THU JUL 5 2012/
.UPDATE...
STORMS TRYING TO REFIRE ALONG OUTFLOW BOUNDARY AS IT MOVES SOUTH
INTO ATL METRO. HAVE TWEAKED WX AND POP GRIDS AGAIN TO ACCOUNT FOR
CURRENT TRENDS. SHOULD BE CLEAR FOR REST OF THE NIGHT NORTH OF THE
BOUNDARY. REST OF FCST LOOKS GOOD.
SNELSON
&&
.PREV DISCUSSION... /ISSUED 812 PM EDT THU JUL 5 2012/
.UPDATE...
QUICK UPDATE TO FINE TUNE POP AND WX GRIDS BASED ON CURRENT TRENDS
ESP MCS OVER ERN TN. LAST SEVERAL HRRR RUNS HAVE BEEN IN GOOD
AGREEMENT ON BRINGING MCS DOWN INTO NRN COUNTIES AROUND 00-01Z AND
INTO ATL METRO AROUND 02-03Z. SHOULD WEAKEN AS IT MOVES SOUTH BUT
EXPECT SIGNIFICANT THREAT FOR DAMAGING WINDS THIS EVENING IN NORTH
GA. WILL UPDATE HWO AS WELL.
SNELSON
.PREV DISCUSSION... /ISSUED 158 PM EDT THU JUL 5 2012/
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
GEORGIA REMAINS UNDER THE EASTERN END OF THE CENTRAL U.S. RIDGE
THROUGH THE PERIOD. ALTHOUGH THE RIDGE IS FORECAST BY THE GFS/NAM
AND ECMWF TO BUILD EASTWARD SOME FRIDAY AND WILL CONTINUE TO BE
STRONG ENOUGH FOR ABOVE NORMAL TEMPERATURES...IT SHOULD NOT BE
STRONG ENOUGH TO SUPPRESS SCATTERED...MAINLY DIURNAL...CONVECTION.
PERSISTENT SURFACE TROUGH IN THE LEE OF THE APPALACHIANS WILL
CONTINUE TO PROVIDE SOME LOW LEVEL SUPPORT FOR THUNDERSTORM
DEVELOPMENT. ANY WEAK MID LEVEL CIRCULATIONS FROM MORE WIDESPREAD
CONVECTION ALONG THE NORTHERN PERIPHERY OF THE RIDGE THAT MAKE IT
AROUND THE EASTERN POINT OF THE RIDGE...LIKE THE PAIR MOVING THROUGH
THE EASTERN OHIO VALLEY AND CENTRAL APPALACHIANS THIS AFTERNOON...
MAY HELP TO FOCUS CONVECTIVE ACTIVITY AS WELL ACROSS NORTH GEORGIA
EACH AFTERNOON. STRONG SURFACE HEATING AND AMPLE LOW LEVEL MOISTURE
ARE IN PLACE AGAIN THIS AFTERNOON AND WILL BE PRESENT FRIDAY
AFTERNOON FOR MODERATE INSTABILITY. HOWEVER...COMBINED WITH WEAK
SHEAR AND A LACK OF A STRONG FOCUSING MECHANISM THIS SHOULD KEEP
SEVERE THUNDERSTORM THREAT ISOLATED.
WITH AFTERNOON HIGH TEMPERATURES EXPECTED TO REMAIN IN THE MID TO
UPPER 90S...AFTERNOON HEAT INDEX VALUES WILL REMAIN UNCOMFORTABLY
HIGH...BUT COMBINED WITH OVERNIGHT LOWS IN THE UPPER 60S TO LOWER
70S IN MOST AREAS WE ARE NOT EXPECTED TO REACH HEAT ADVISORY
CRITERIA THROUGH THE PERIOD.
20
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
NO CHANGES TO CURRENT LONG TERM PLANNED. PREVIOUS LONG TERM
DISCUSSION FOLLOWS...
/ISSUED 414 AM EDT THU JUL 5 2012/
THE MODELS ARE IN GOOD AGREEMENT IN THE EXTENDED PERIODS. THE UPPER
LEVEL RIDGING SHIFTS WEST OVER THE CENTRAL PLAINS ALLOWING WEAK
IMPULSES TO CONTINUE TO IMPACT PORTIONS OF THE SOUTHEAST...
PROVIDING FOCUS FOR MAINLY DIURNALLY DRIVEN CONVECTION. MODELS
AGREE MAIN FOCUS TO BE ACROSS NORTH GEORGIA ON SATURDAY AND SUNDAY
AHEAD OF A BROAD LONGWAVE TROUGH WHICH SETS UP OVER THE EASTERN
U.S. BY MONDAY AFTERNOON. AT THE SFC...WEAK SURFACE BOUNDARY
REMAINS IN CLOSE PROXIMITY TO THE FORECAST AREA...EVENTUALLY
SAGGING SOUTH BY SUNDAY NIGHT...SPREADING THE FOCUS FOR
CONVECTION SOUTHWARD THROUGH THE END OF THE EXTENDED PERIODS.
MODELS CONTINUE TO SHOW GOOD MOISTURE ACROSS THE AREA...
PRECIPITABLE WATER REMAINS NEAR 2 INCHES...AND PLENTY OF
INSTABILITY...SURFACE CAPES GREATER THAN 1500 EACH AFTERNOON WITH
DIURNALLY DRIVEN CONVECTION POSSIBLE ACROSS ALL OF NORTH
AND CENTRAL GEORGIA. GUIDANCE TEMPERATURES NEAR OR JUST ABOVE
NORMAL THROUGH THE EXTENDED PERIODS. BELIEVE MONDAY THROUGH
WEDNESDAY AFTERNOON TEMPERATURES ARE ON THE COOL SIDE AS MODELS
MAY BE OVERDOING CLOUD COVER ASSOCIATED WITH THE SURFACE BOUNDARY.
ANTICIPATE LESS CLOUDS UNTIL HEATING KICKS IN EACH DAY AND HAVE
GONE WARMER THAN GUIDANCE LATTER PORTIONS OF THE FORECAST.
ATWELL/17
&&
.AVIATION...
06Z UPDATE...
VFR CONDITIONS EXPECTED THROUGH TAF PERIOD. WINDS LOOK TO BE LIGHT
TO VRB OVERNIGHT BECOMING MOSTLY NW UNDER 10KTS FOR THE MAJORITY
OF THE NORTHERN TAF SITES AND WESTERLY FOR KCSG AND KMCN AFTER
16Z. BKN100 CIGS OVERNIGHT LOOK TO BECOME SCT060 AFTER 16Z AS
WELL. DIURNALLY DRIVEN CONVECTION LOOKS TO DEVELOP AGAIN LATE THIS
AFTERNOON AS THE BEST CHANCE WILL BE NEAR 21-24Z... THEREFORE HAVE
INCLUDED PROB30 GROUP. WINDS MAY BECOME GUSTY AND VRB DUE TO ANY
NEARBY STORMS AND THEN BECOME LIGHT AGAIN LATE IN THE EVENING.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE ON CONVECTIVE ELEMENTS DURING AFTERNOON.
HIGH CONFIDENCE ON ALL ELSE.
BAKER
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 98 72 99 73 / 40 40 30 20
ATLANTA 97 75 96 75 / 40 40 30 20
BLAIRSVILLE 94 67 91 69 / 40 40 40 20
CARTERSVILLE 98 69 98 70 / 40 40 40 20
COLUMBUS 96 75 94 74 / 40 40 30 20
GAINESVILLE 97 73 98 74 / 40 40 40 20
MACON 96 74 96 73 / 40 40 30 20
ROME 98 69 98 70 / 40 40 40 20
PEACHTREE CITY 96 69 95 71 / 40 40 30 20
VIDALIA 96 75 96 75 / 40 40 30 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SNELSON
LONG TERM....ATWELL/17
AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1109 PM CDT THU JUL 5 2012
.AVIATION...
VFR WX WILL CONTINUE WITH NO RAIN...OR CLOUDS UNDER 25KFT SHOULD
OCCUR. VISIBILITIES WILL BE 6 MILES OR BETTER THROUGH THE PERIOD.
LIGHT AND VARIABLE WINDS THROUGH 14Z...AFTER WHICH SOUTH AROUND 8
TO 10 KTS AGAIN. THE HIGH PRESSURE BRINGING THIS WEATHER WILL MOVE
SOUTH...ALLOWING A COLD FRONT TO ARRIVE SATURDAY.
ERVIN
&&
.PREV DISCUSSION... /ISSUED 319 PM CDT THU JUL 5 2012/
SYNOPSIS...
12Z UA ANALYSIS HAD A LLJ RUNNING FROM WEST TEXAS INTO NORTHWEST
IOWA. AN 850MB BOUNDARY/FRONT RAN FROM THE ARROWHEAD OF MINNESOTA
INTO WESTERN NEBRASKA. MOISTURE WAS POOLING AHEAD OF THE BOUNDARY
WITH 850MB DEW POINTS IN THE MID AND UPPER TEENS FROM SOUTHERN
MINNESOTA INTO WISCONSIN. SATELLITE TRENDS THROUGH MID AFTERNOON
SHOW CLOUDS CONTINUE TO THIN FROM THE NOCTURNAL CONVECTION OVER
THE AREA WITH DIURNAL CU AND ISOLATED CONVECTION IN NORTHEAST
ILLINOIS.
18Z SFC ANALYSIS HAD WEAK LOWS NEAR KLSE AND KSUX. AN OUTFLOW
BOUNDARY CONNECTED THE TWO LOWS AND RAN ACROSS NORTHERN IOWA. THE
MAIN COLD FRONT RAN FROM WESTERN LAKE SUPERIOR TO KFSD AND THEN
INTO SOUTHERN SOUTH DAKOTA. DEW POINTS WERE IN THE 40S AND 50S
BEHIND THE FRONT WITH WIDESPREAD 60S AND SOME 70S AHEAD OF THE FRONT.
SHORT TERM...TONIGHT AND FRIDAY
THERE IS SOME MOISTURE ABOVE THE LFC SO THERE REALLY IS NO CAP.
THE LACK OF A TRIGGER HAS SO FAR PREVENTED ANY ELEVATED CONVECTION
FROM DEVELOPING. ELEVATED CONVECTION HAS DEVELOPED IN NORTHEAST
ILLINOIS IN RESPONSE TO WEAK FORCING PER THE RAP MODEL. DIURNAL CU
HAS DEVELOPED ALONG THE TRUE COLD FRONT AND VISIBLE/WATER VAPOR
IMAGERY INDICATES A WEAK VORT MAX OR MCV MOVING ACROSS SOUTHERN
MINNESOTA. THUS CONVECTION SHOULD DEVELOP IN THE NEXT FEW HOURS IN
MINNESOTA ALONG THE FRONT.
THE CONVECTION IN NORTHEAST ILLINOIS WILL NEED TO BE WATCHED. RAP
TRENDS SHOW THE WEAK FORCING GETTING CLOSE TO THE EASTERN CWFA
LATE THIS AFTERNOON. MCS...LIFT...AND WAA TOOLS ALL SUGGEST
ADDITIONAL CONVECTION DEVELOPING LATE THIS AFTERNOON IN NORTHEAST
ILLINOIS THAT MAY APPROACH THE FAR NORTHEAST/EAST PARTS OF THE
CWFA. IF NOTHING DEVELOPS BY 6 PM...THEN THE CWFA SHOULD BE DRY
THROUGH MIDNIGHT.
AFTER MIDNIGHT ANOTHER MCS SHOULD DEVELOP IN SOUTHERN MINNESOTA
AND GENERALLY MOVE EAST. THE GENESIS REGION SHOULD BE SOUTHWEST
MINNESOTA IN THE STRONGEST PART OF THE WEAK LLJ. OUTFLOWS FROM
THIS MCS MAY INITIATE NEW CONVECTION PRIOR TO SUNRISE JUST OUTSIDE
OF THE CWFA.
ASSUMING THE MINNESOTA MCS DEVELOPS AND MOVES EAST AS EXPECTED
THEN FRIDAY SHOULD SEE PLENTY OF DEBRIS CLOUDS THAT TAKE MOST OF
THE MORNING TO THIN AND DISSIPATE. THESE CLOUDS IN TURN SHOULD
HOLD DOWN TEMPERATURES JUST A LITTLE BUT MAX TEMPERATURES SHOULD
BE SIMILAR TO OR 1-2 DEGREES WARMER THAN TODAY.
THE HEAT HEADLINES WILL REMAIN WITH NO CHANGES. DEW POINTS SHOULD
AGAIN DROP TONIGHT AS EVAPOTRANSPIRATION FROM THE CORN BECOMES
INACTIVE. DEW POINTS WILL CLIMB AGAIN FRIDAY INTO THE UPPER 60S TO
POSSIBLY MID 70S AS THE CORN ACTIVELY EVAPOTRANSPIRATES. THE
RESULTANT HEAT INDEX READINGS SHOULD BE 105 TO 110. ..08..
LONG TERM...FRIDAY NIGHT THROUGH NEXT THURSDAY
BREAK IN THE HEAT WITH MORE SEASONABLE TEMPS AND COMFORTABLE HUMIDITY
ARRIVING BY LATE IN THE WEEKEND. THE FRONT BRINGING THE RELIEF
UNFORTUNATELY DOESN/T FIGURE TO BRING MUCH IN WAY OF NEEDED RAINFALL
FOR AREA CORN CROPS IN CRITICAL POLLINATION STAGE. MOST OF THE
AREA IS NOW EXPERIENCING MODERATE DROUGHT CONDITIONS PER THE LATEST
U.S. DROUGHT MONITOR RELEASED THIS AM.
SURFACE COLD FRONT TO SAG THROUGH THE REGION SAT INTO SAT NGT. FRI
NGT WILL FEATURE CONTINUATION OF EXCESSIVE HEAT WARNING WITH VERY
WARM AND HUMID CONDITIONS WITH HEAT INDICES REMAINING ABOVE 75. NOT
LIKELY TO SEE SFC BASED PRE-FRONTAL CONVECTION SAT INTO SAT EVE DUE
TO STRONG CAPPING INVERSION... WEAK LOW LEVEL CONVERGENCE AND
ABSENCE OF PRONOUNCED SHORTWAVE AND MID LEVEL COOLING. THUS... ANY
PCPN WOULD BE POST-FRONTAL ROOTED WITH CONVERGENCE AXIS NEAR TO
ABOVE 850 MILLIBARS ALSO COINCIDENT WITH DEEPER MOISTURE FETCH WITH
MONSOONAL CONNECTION ROTATING AROUND THE PERIPHERY OF THE UPPER
RIDGE /HEAT DOME/ TO OUR SOUTH. WITH LACK OF CONVECTION PRE-FRONTAL
THEN LESS DEBRIS CLOUDINESS THUS INCREASING LIKELIHOOD OF NEEDING TO
EXTEND HEAT WARNING THROUGH SAT FOR A GOOD PORTION OF THE CWA FOR
HIGHS ONCE AGAIN WELL INTO THE 90S TO AROUND 100F AND HEAT INDICES
100-110+. 850 MILLIBAR FRONT OR WEAKENING CONVERGENCE AXIS PASSES
SUN INTO SUN EVE TAKING MOISTURE WITH IT. ASIDE FROM THE WEAK
CONVERGENCE HARD PRESSED TO FIND COHERENT FORCING OR TRIGGER TO
GENERATE WIDESPREAD OR ORGANIZED RAIN. GIVEN ALL OF THE ABOVE HAVE
BACKED OFF ON POPS TO MAINLY SLIGHT CHC DURING THE ENTIRE PERIOD
SAT-SUN.
MON-THU... GENERAL PATTERN WILL FEATURE A BROAD TROUGH OVER THE
CENTRAL AND EASTERN CONUS... AND RIDGE OVER THE INTERMOUNTAIN
WEST. RESULTING NORTHWEST FLOW WILL KEEP TEMPS AROUND NORMAL WHICH
COUPLED WITH LOWER HUMIDITY TO MAKE FOR NICE AND COMFORTABLE STRETCH
OF WEATHER. PCPN CHCS ARE NOT ZERO AS WE COULD SEE A FEW SHORTWAVES
PASS IN THE FLOW... BUT WITH LIMITED MOISTURE AND TIMING/STRENGTH
SO DIFFICULT TO PIN DOWN THIS FAR OUT HAVE MAINTAINED A DRY FORECAST.
MCCLURE
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...EXCESSIVE HEAT WARNING UNTIL 7 AM CDT SATURDAY FOR BENTON-
BUCHANAN-CEDAR-CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-
IOWA-JACKSON-JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-
MUSCATINE-SCOTT-VAN BUREN-WASHINGTON.
IL...EXCESSIVE HEAT WARNING UNTIL 7 AM CDT SATURDAY FOR BUREAU-
CARROLL-HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-
MERCER-PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE.
MO...EXCESSIVE HEAT WARNING UNTIL 7 AM CDT SATURDAY FOR CLARK-
SCOTLAND.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
424 AM EDT FRI JUL 6 2012
.SYNOPSIS...
HIGH PRESSURE WILL MOVE EAST OF THE AREA TODAY. A COLD FRONT WILL
APPROACH LATER TODAY AND CROSS THE REGION TONIGHT. ANOTHER COLD
FRONT WILL CROSS THE REGION SATURDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
CHALLENGE THIS TERM WILL BE CLOUDS/FOG THIS MORNING AND CONVECTION
LATER TODAY INTO TONIGHT.
THE LATEST IR SATL IMAGERY SHOWING LOW CLOUDS/FOG DEVELOPING AND MOVING
ACROSS THE AREA. THE HRRR WAS HANDLING THIS SET QUITE WELL AND
FOLLOWED W/IT THROUGH THE MORNING HRS. THIS MEANS CLOUDS AND AREAS
OF FOG ACROSS AT LEAST 1/2 OF THE CWA, BUT AS MORNING WEARS ON AND
SUN BEGINS TO WORK ON THE ATMOSPHERE, CLOUDS SHOULD BREAK UP
W/SKIES BECOMING PARTLY TO MOSTLY SUNNY. THIS WILL ALLOW
TEMPERATURES TO RESPOND ACCORDINGLY W/TEMPERATURES MAXING OUT IN
THE 80 FOR THE CWA W/THE EXCEPTION OF THE COAST AS A SEA BREEZE
DEVELOPING THIS AFTERNOON WILL ALLOW FOR COOLER TEMPERATURES RIGHT
AT THE COAST. NOT CONFIDENT ENOUGH TO BRING THE SEA BREEZE FURTHER
INLAND TOWARD THE BANGOR REGION AND DECIDED TO HAVE WARMER
TEMPERATURES THERE.
IN REGARDS TO CONVECTION, THE ATMOSPHERE LOOKS LIKE IT WILL
DESTABILIZE THIS AFTERNOON THANKS IN PART TO HEATING. MDL
SOUNDINGS ESPECIALLY THE NAM RAMP UP THE SBCAPES TO 800-1200
JOULES ACROSS THE NORTH AND WEST. LIS DROP TO -2 TO -5 W/K INDICES
OF 30+. 0-6KM BULK SHEAR IS 30+ KTS. INHIBITING FACTORS ARE DEEP
MOISTURE WHICH ATTM APPEARS TO BE LIMITED TO BELOW 700 MBS AND
LOW/MID LEVEL LAPSE RATES <6.5C/KM. SOME MID LEVEL WARMING WILL
INHIBIT INITATION, BUT THERE DOES APPEAR TO BE SOME COOLING AROUND
00Z AND A MID/UPPER LEVEL SPEED MAX OF 40-50 KTS AS A COLD FRONT
MOVES IN FROM THE WEST. THIS SPEED MAX COULD OFFSET THE WEAKER
LAPSE RATES AND ALLOW FOR CONVECTION W/SOME STORMS TO BE STRONG TO
POSSIBLY SEVERE. WIND LOOKS TO BE THE MAIN THREAT AS FREEZING
LEVELS ARE SHOWN TO BE AT 13+K FT. ANOTHER THING TO NOTE IS THAT
THERE IS DECENT DIRECTIONAL SHEAR IN LLVL WHICH COULD ALLOW FOR
SOME ROTATION IF STRONGER STORMS FIRE. COLLABORATED W/GYX AND SPC
ON THIS POTENTIAL AND THINKING ATTM ANY SEVERITY WILL BE ISOLD AND
KEPT ACROSS THE NORTH AND WEST. THIS WILL NEED TO BE ASSESSED BY
THE DAYCREW. ACTIVITY WILL MOVE TO THE EAST TONIGHT AND WEAKEN AS
FORCING LESSENS W/LEFTOVER SHOWERS. BOOSTED OVERNIGHT MINS USING
THE NAM12 TEMPERATURES.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
A 500 MB LOW WILL REMAIN ACROSS EASTERN QUEBEC THROUGH SUNDAY WITH
WEST TO NORTHWEST FLOW ALOFT CONTINUING THROUGH SUNDAY. THIS WILL
ALLOW A SERIES OF WEAK COLD FRONT TO CROSS THE REGION THROUGH
SUNDAY. THIS WILL BRING THE CHANCE FOR SHOWERS AND THUNDERSTORMS
TO THE REGION ON SATURDAY WITH ONLY AN ISOLATED SHOWER OR
THUNDERSTORM ON SUNDAY. HIGH TEMPERATURES ON SATURDAY WILL RANGE
FRROM THE LOW 80S NORTH AND MID 80S DOWNEAST. HIGHS ON SUNDAY WILL
RANGE FROM THE LOWER 70S NORTH AND MID 70S TO NEAR 80 ON SUNDAY.
LOW SATURDAY NIGHT WILL RANGE FROM THE MID 50S NORTH AND UPPER 60S
DOWNEAST.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
A MAINLY ZONAL FLOW ALOFT WILL PERSIST THROUGH THE MIDWEEK PERIOD.
THIS WILL BRING MAINLY DRY WEATHER TO THE REGION. TEMPERATURES
THROUGH THE PERIOD WILL BE NEAR NORMAL.
&&
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: IFR/MVFR ACROSS THE NORTHERN TERMINALS THIS MORNING AND
PROJECT TO DEVELOP ACROSS KBGR/KBHB FOR A TIME THIS MORNING.
CONDITIONS ARE EXPECTED TO IMPROVE TO VFR BY MID TO LATE MORNING.
SOME CONCERN TO STRONGER TSTMS ACROSS THE NORTHERN TERMINALS LATER
THIS AFTERNOON INTO EARLY TONIGHT WHICH COULD DROP CONDITIONS TO
MVFR FOR A BRIEF TIME. LLWS COULD BE A ISSUE W/THE TSTMS.
SHORT TERM: MAINLY VFR CONDITIONS. COULD BE BRIEF MVFR IN ANY
HEAVIER CONVECTION SATURDAY AFTERNOON.
&&
.MARINE...
NEAR TERM: NO HEADLINES. SE SWELL CONTINUES AND DECIDED TO KEEP IT
GOING THROUGH TONIGHT AS 8-9 SECOND PERIOD. WAVE HEIGHTS OF 2-3 FT
INTO TONIGHT. WINDS WILL BE 10 KTS OR LESS.
SHORT TERM: WINDS/SEAS WILL REMAIN BELOW SCA LEVELS THROUGH THE
PERIOD.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HEWITT
MARINE...HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
522 AM EDT FRI JUL 6 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 522 AM EDT FRI JUL 6 2012
WV IMAGERY AND RUC ANALYSIS SHOWS AN UPPER RIDGE OVER THE CNTRL
CONUS AND AN UPPER LOW OVER HUDSON BAY SUPPRESSING THE NRN EXTENT
OF THE UPPER RIDGE. SHORTWAVE IN ERN MONTANA IS ROTATING NNE UP THE
RIDGE AND THE SHORTWAVE COMBINED WITH A SFC LOW IN ERN SD HAS
CONTINUED TO PRODUCE A LARGE THUNDERSTORM COMPLEX IN NCNTRL SD AND
CNTRL ND. CLOSER TO UPPER MI...SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS HAVE DEVELOPED OVER THE LAST COUPLE HOURS IN
CNTRL/NRN MN ASSOCIATED WITH H700-500 MOISTURE AND EDGE OF
EXITING 6.5-7.5 C/KM LAPSE RATES. WITH THE RIDGE IN PLACE...EXPECT
THE SHOWERS TO CONTINUE NNE EARLY THIS MORNING DUE TO THE
RIDGE...WHILE THE STEEPER LAPSE RATES SHIFT E. THIS SHOULD KEEP
PCPN MAINLY TO THE W OF LK SUPERIOR...ALTHOUGH THERE ARE SOME HINTS
OF IT TRYING TO BUILD E TOWARDS THE LK. OVER UPPER MI...HIGH
PRESSURE RIDGE IS IN PLACE AND HAS LED TO CLEAR SKIES AND
TEMPERATURES IN THE 60S.
THE HIGH PRESSURE SHOULD LEAD TO A SUNNY START TO THE DAY...WITH
MID CLOUDS PUSHING EAST INTO THE WRN CWA AS THE DAY GOES ON. H850
TEMPS ARE SLIGHTLY COOLER TODAY BEHIND THE COLD FRONT WHICH WILL
LEAD TO HIGHS IN THE 80S...WITH A FEW 90S OVER THE SCNTRL. SLIGHTLY
COOLER VALUES ARE EXPECT NEAR LK SUPERIOR DUE TO LIGHT NRLY FLOW
AROUND THE HIGH WHICH WILL LEAD TO LK BREEZE DEVELOPMENT. TD
VALUES WILL BE MUCH LOWER THAN YEST...IN THE 50S...AND
WHEN COMBINED WITH THE LOWER TEMPS WILL MAKE IT FEEL MUCH MORE
COMFORTABLE OUTSIDE.
ATTENTION THEN TURNS TO THE UPSTREAM CONVECTION AS IT WILL BE THE
MAIN WEATHER MAKER FOR THE SHORT TERM. SHORTWAVE IN NRN WYOMING AND
ERN MONTANA WILL BE ROTATING AROUND THE UPPER RIDGE THAT HAS BEEN
CAUSING THE WARM/HUMID WEATHER...ALONG WITH BOUTS OF THUNDERSTORMS.
THIS WILL ONCE AGAIN BE THE CASE WITH THIS SHORTWAVE...WHICH
PRODUCED CONVECTION OVER NWRN SD/ND OVERNIGHT AND WILL BRING ANOTHER
PERIOD OF MODERATE RAIN. EVEN THOUGH THE BEST INSTABILITY GRADIENT
STRETCHES FROM ND SE THROUGH CNTRL WI...THINK THE UPPER RIDGE WILL
STEER THE CURRENT CONVECTION MORE TO THE NE THROUGH THE MORNING
HOURS.
BEST AREA OF THE WEAK SHORTWAVE ENERGY WILL SLIDE ACROSS THE NRN
HALF OF THE CWA LATE THIS AFTN AND TONIGHT...ALONG WITH THE H500
HEIGHT FALLS. THIS WILL COINCIDE WITH THE RIGHT ENTRANCE OF THE
UPPER JET ROTATING AROUND THE UPPER LOW OVER HUDSON BAY. FARTHER TO
THE S...STRONG FGEN FROM H800 TO H650...WILL BE OVER WRN LK SUPERIOR
LATE THIS AFTN AND EVENING AND THEN SHIFT SSE TONIGHT. AS EXPECTED
TIGHT H850 THERMAL GRADIENT AND WAA/ISENTROPIC ASCENT OVER SRN UPPER
MI. THUS...EXPECT BEST PCPN CHANCES FROM WRN LK SUPERIOR THROUGH WRN
UPPER MI AND THEN SLIDING SE ACROSS ERN UPPER MI OVERNIGHT WITH A
STRONGER NRLY H850 PUSH AND VEERING WINDS TO THE EAST S OF THE H850
FRONT. OVER THE NRN PART OF LK SUPERIOR...LLVL DRY AIR AND DOWNWARD
AGEOSTROPHIC CIRCULATION MAY END UP LIMITING THE NRN EXTENT OF
THE PCPN.
FAIRLY GOOD CONSENSUS IN THE 00Z MODELS ON THE QPF AMNTS...AS
THEY RANGE FROM SWATHS OF 1-1.7IN ON THE NAM/GEM-REG TO 0.5-0.75IN
ON ECMWF/GFS. ECMWF IS SLIGHTLY FARTHER S THAN THE OTHER TWO...WITH
THE GFS SLIGHTLY FARTHER TO THE NW. LOOKING AT THE 21Z SREF
RUN...IT HAS A 30 PERCENT PROB OVER WRN U.P. OF 1.0IN OF RAIN
TONIGHT AND 50-70 PERCENT OF 0.5 OVER THE W HALF. PWATS ARE AROUND
150-200 PERCENT OF NORMAL...WHICH WOULD SUPPORT THE POSSIBILITY OF
CORRIDORS OF HEAVY RAIN. HAVE BUMPED UP QPF AMNTS SOME AND HAVE
TOTAL AMNTS WITH THIS SYSTEM OF 0.75-1.0IN OVER THE INTERIOR WEST.
WITH THESE AMNTS...WILL NEED TO WATCH IRON COUNTY AND PAINT RIVER
WITH THE ABUNDANCE OF RAIN THEY HAVE SEEN IN THE LAST WEEK /RADAR
ESTIMATED OVER 8IN/. FARTHER TO THE EAST...THINK THE VEERING H850
WINDS WILL REALLY DIMINISH AMNTS AND HAVE LESS THAN 0.5IN E OF
MUNISING/MANISTIQUE.
FINALLY...THE CONVECTIVE POTENTIAL. H850 LIFTED ELEVATED CAPE
GRADIENT IS RIGHT ALONG WI BORDER. IT IS A VERY SKINNY CAPE...WITH
NCAPE VALUES AROUND .08...AND EFFECTIVE SHEAR VALUES AROUND 30KTS
WOULD INDICATE LIMITED POTENTIAL FOR HAIL. 3HR SPC CALIBRATED
THUNDER PROBS INDICATE THE BEST CHANCES ALONG THE WI BORDER
TONIGHT...WHICH MATCHES UP WELL WITH INSTABILITY GRADIENT AND
POTENTIAL CONVECTION DEVELOPING IN CNTRL MN AND NW WI.
THEREFORE...WILL LIMIT CHANCE THUNDER TO THE WI BORDER AND JUST HAVE
SLIGHT CHANCE OVER ALL BUT THE FAR N.
AT THE PRESENT TIME...FEEL FAIRLY CONFIDENT IN THE GOING FORECAST.
ONLY HAVE TWO CONCERNS. ONE...IF THE CONVECTION CURRENTLY GOING IN
NCNTRL SD CAN STAY ON THE INSTABILITY GRADIENT AND HOLD OFF THE
STEERING FROM THE RIDGE...WHICH DOESN/T SEEM TOO LIKELY.
TWO...WOULD BE IF CONVECTION THAT MAY FIRE ALONG THE WARM FRONT AND
INSTABILITY GRADIENT IN CNTRL MN AND NW WI THIS AFTN...WHICH COULD
DISRUPT SOME OF THE LLVL FLOW AND MOISTURE ADVECTION INTO THIS
AREA. BUT WITH THE WAY THE CONVECTION AND SHOWERS HAVE BEEN GOING
IN THE DAKOTAS...FEEL THAT MUCH OF THE AREA WOULD STILL SEE RAIN
IF THAT OCCURS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 522 AM EDT FRI JUL 6 2012
SATURDAY...HIGH PRESSURE AND STRONG DRYING BEHIND THE FRONT SAGGING
TO THE SOUTH WILL BRING CLEARING SKIES AFTER ANY ANY LEFTOVER LIGHT
SHOWERS OVER THE SOUTH EARLY. MAX READINGS SHOULD ALSO BE LOWER WITH
INLAND READINGS IN THE UPPER 70S AND LOWER 80S AS 850 MB TEMPS DROP
INTO THE 12C TO 14C RANGE. LIGHT NRLY GRADIENT FLOW WILL KEEP TEMPS
MAINLY IN THE LOWER 70S NEAR LAKE SUPERIOR. WITH DEWPOINTS DROPPING
INTO THE 50S...FAVORABLE RADIAIONAL COOLING CONDITIOINS SHOULD ALLOW
TEMPS TO DROP INTO THE LOWER TO MID 50S INLAND.
SUNDAY...THE COMBINATION OF A WEAK SHORTWAVE DROPPING INTO THE AREA
IN THE NW FLOW PATTERN AND SBCAPE VALUES INTO THE 400-600 J/KG RANGE
DURING PEAK HEATING MAY BE ENOUGH TO TRIGGER SOME ISOLD INLAND
SHRA/TSRA OVER THE INTERIOR WEST. HOWEVER...ANY RAINFALL AMOUNTS
WOULD BE LIGHT. EVEN THOUGH SEVERAL MODELS SUGGEST THAT ANOTHER WEAK
SHORTWAVE SUNDAY NIGHT MAY ALSO PRODUCE SOME LIGHT SHOWERS...GIVEN
THE GENERALLY DRY AIRMASS...PREFERRED THE ECMWF WHICH DOES NOT SHOW
ANY QPF.
MONDAY THROUGH THURSDAY...A MORE AMPLIFIED PATTERN WITH A MID/UPPER
LEVEL RIDGE OVER WRN NOAM WILL RESULT IN CONTINUED NW FLOW THROUGH
THE WRN GREAT LAKES. THE POTENTIAL ALSO REMAINS FOR WEAK SHORTWAVES
TO MOVE THROUGH THE AREA WITH LOWER END PCPN CHANCES.
HOWEVER...CONFIDENCE IN THE TIMING/STRENGTH OF THESE FEATURES IS
LOW. TENDED TO FAVOR THE DRIER ECMWF QPF...GIVEN THE GFS MOISTURE
BIAS. TEMPERATURES WILL REMAIN CLOSER TO SEASONAL AVERAGES WITH
HIGHS IN THE LOW TO MID 70S MON CLIMBING TO THE UPPER 70S AND LOWER
80S BY WED-THU.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 130 AM EDT FRI JUL 6 2012
DRIER AIRMASS HAS SETTLED OVER THE AREA AHEAD OF WEAK HIGH PRES
DRIFTING TOWARD THE UPPER GREAT LAKES. RESULT WILL BE VFR CONDITIONS
AT KIWD/KCMX/KSAW THRU THIS AFTN. APPROACHING DISTURBANCE WILL BRING
THICKENING MID CLOUDS TODAY...AND SHRA COULD SPREAD INTO WESTERN
UPPER MI...KIWD IN PARTICULAR...LATER IN THE AFTN. MDT TO POSSIBLY
HVY SHRA WILL THEN OVERSPREAD THE AREA THIS EVENING WITH THE HEAVIER
RAINFALL MORE LIKELY AT KIWD/KSAW. CONDITIONS AT KIWD/KSAW SHOULD
FALL TO MVFR AND POSSIBLY TO IFR. WHILE TSRA WILL BE MORE LIKELY
JUST TO THE S...THE NRN EDGE OF THE INSTABILITY GRADIENT CERTAINLY
COULD SUPPORT TSRA AT KIWD/KSAW TONIGHT...BUT HAVE HELD OFF ON
MENTION UNTIL THERE IS INCREASED CONFIDENCE FOR TSRA TO OCCUR.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 522 AM EDT FRI JUL 6 2012
HIGH PRESSURE OVER LAKE SUPERIOR THIS MORNING WILL KEEP WINDS BELOW
20 KTS TODAY. A LOW PRESSURE TROUGH WILL CROSS JUST S OF UPPER MI
TONIGHT...WHICH WILL SHIFT WINDS MORE TO THE N. BEHIND THIS
TROUGH...HIGH PRESSURE WILL SETTLE BACK OVER THE UPPER GREAT LAKES
THROUGH THE MIDDLE OF NEXT WEEK AND WILL KEEP WINDS LIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...JLB
AVIATION...ROLFSON
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
516 AM EDT FRI JUL 6 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 514 AM EDT FRI JUL 6 2012
WV IMAGERY AND RUC ANALYSIS SHOWS AN UPPER RIDGE OVER THE CNTRL
CONUS AND AN UPPER LOW OVER HUDSON BAY SUPPRESSING THE NRN EXTENT
OF THE UPPER RIDGE. SHORTWAVE IN ERN MONTANA IS ROTATING NNE UP THE
RIDGE AND THE SHORTWAVE COMBINED WITH A SFC LOW IN ERN SD HAS
CONTINUED TO PRODUCE A LARGE THUNDERSTORM COMPLEX IN NCNTRL SD AND
CNTRL ND. CLOSER TO UPPER MI...SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS HAVE DEVELOPED OVER THE LAST COUPLE HOURS IN
CNTRL/NRN MN ASSOCIATED WITH H700-500 MOISTURE AND EDGE OF
EXITING 6.5-7.5 C/KM LAPSE RATES. WITH THE RIDGE IN PLACE...EXPECT
THE SHOWERS TO CONTINUE NNE EARLY THIS MORNING DUE TO THE
RIDGE...WHILE THE STEEPER LAPSE RATES SHIFT E. THIS SHOULD KEEP
PCPN MAINLY TO THE W OF LK SUPERIOR...ALTHOUGH THERE ARE SOME HINTS
OF IT TRYING TO BUILD E TOWARDS THE LK. OVER UPPER MI...HIGH
PRESSURE RIDGE IS IN PLACE AND HAS LED TO CLEAR SKIES AND
TEMPERATURES IN THE 60S.
THE HIGH PRESSURE SHOULD LEAD TO A SUNNY START TO THE DAY...WITH
MID CLOUDS PUSHING EAST INTO THE WRN CWA AS THE DAY GOES ON. H850
TEMPS ARE SLIGHTLY COOLER TODAY BEHIND THE COLD FRONT WHICH WILL
LEAD TO HIGHS IN THE 80S...WITH A FEW 90S OVER THE SCNTRL. SLIGHTLY
COOLER VALUES ARE EXPECT NEAR LK SUPERIOR DUE TO LIGHT NRLY FLOW
AROUND THE HIGH WHICH WILL LEAD TO LK BREEZE DEVELOPMENT. TD
VALUES WILL BE MUCH LOWER THAN YEST...IN THE 50S...AND
WHEN COMBINED WITH THE LOWER TEMPS WILL MAKE IT FEEL MUCH MORE
COMFORTABLE OUTSIDE.
ATTENTION THEN TURNS TO THE UPSTREAM CONVECTION AS IT WILL BE THE
MAIN WEATHER MAKER FOR THE SHORT TERM. SHORTWAVE IN NRN WYOMING AND
ERN MONTANA WILL BE ROTATING AROUND THE UPPER RIDGE THAT HAS BEEN
CAUSING THE WARM/HUMID WEATHER...ALONG WITH BOUTS OF THUNDERSTORMS.
THIS WILL ONCE AGAIN BE THE CASE WITH THIS SHORTWAVE...WHICH
PRODUCED CONVECTION OVER NWRN SD/ND OVERNIGHT AND WILL BRING ANOTHER
PERIOD OF MODERATE RAIN. EVEN THOUGH THE BEST INSTABILITY GRADIENT
STRETCHES FROM ND SE THROUGH CNTRL WI...THINK THE UPPER RIDGE WILL
STEER THE CURRENT CONVECTION MORE TO THE NE THROUGH THE MORNING
HOURS.
BEST AREA OF THE WEAK SHORTWAVE ENERGY WILL SLIDE ACROSS THE NRN
HALF OF THE CWA LATE THIS AFTN AND TONIGHT...ALONG WITH THE H500
HEIGHT FALLS. THIS WILL COINCIDE WITH THE RIGHT ENTRANCE OF THE
UPPER JET ROTATING AROUND THE UPPER LOW OVER HUDSON BAY. FARTHER TO
THE S...STRONG FGEN FROM H800 TO H650...WILL BE OVER WRN LK SUPERIOR
LATE THIS AFTN AND EVENING AND THEN SHIFT SSE TONIGHT. AS EXPECTED
TIGHT H850 THERMAL GRADIENT AND WAA/ISENTROPIC ASCENT OVER SRN UPPER
MI. THUS...EXPECT BEST PCPN CHANCES FROM WRN LK SUPERIOR THROUGH WRN
UPPER MI AND THEN SLIDING SE ACROSS ERN UPPER MI OVERNIGHT WITH A
STRONGER NRLY H850 PUSH AND VEERING WINDS TO THE EAST S OF THE H850
FRONT. OVER THE NRN PART OF LK SUPERIOR...LLVL DRY AIR AND DOWNWARD
AGEOSTROPHIC CIRCULATION MAY END UP LIMITING THE NRN EXTENT OF
THE PCPN.
FAIRLY GOOD CONSENSUS IN THE 00Z MODELS ON THE QPF AMNTS...AS
THEY RANGE FROM SWATHS OF 1-1.7IN ON THE NAM/GEM-REG TO 0.5-0.75IN
ON ECMWF/GFS. ECMWF IS SLIGHTLY FARTHER S THAN THE OTHER TWO...WITH
THE GFS SLIGHTLY FARTHER TO THE NW. LOOKING AT THE 21Z SREF
RUN...IT HAS A 30 PERCENT PROB OVER WRN U.P. OF 1.0IN OF RAIN
TONIGHT AND 50-70 PERCENT OF 0.5 OVER THE W HALF. PWATS ARE AROUND
150-200 PERCENT OF NORMAL...WHICH WOULD SUPPORT THE POSSIBILITY OF
CORRIDORS OF HEAVY RAIN. HAVE BUMPED UP QPF AMNTS SOME AND HAVE
TOTAL AMNTS WITH THIS SYSTEM OF 0.75-1.0IN OVER THE INTERIOR WEST.
WITH THESE AMNTS...WILL NEED TO WATCH IRON COUNTY AND PAINT RIVER
WITH THE ABUNDANCE OF RAIN THEY HAVE SEEN IN THE LAST WEEK /RADAR
ESTIMATED OVER 8IN/. FARTHER TO THE EAST...THINK THE VEERING H850
WINDS WILL REALLY DIMINISH AMNTS AND HAVE LESS THAN 0.5IN E OF
MUNISING/MANISTIQUE.
FINALLY...THE CONVECTIVE POTENTIAL. H850 LIFTED ELEVATED CAPE
GRADIENT IS RIGHT ALONG WI BORDER. IT IS A VERY SKINNY CAPE...WITH
NCAPE VALUES AROUND .08...AND EFFECTIVE SHEAR VALUES AROUND 30KTS
WOULD INDICATE LIMITED POTENTIAL FOR HAIL. 3HR SPC CALIBRATED
THUNDER PROBS INDICATE THE BEST CHANCES ALONG THE WI BORDER
TONIGHT...WHICH MATCHES UP WELL WITH INSTABILITY GRADIENT AND
POTENTIAL CONVECTION DEVELOPING IN CNTRL MN AND NW WI.
THEREFORE...WILL LIMIT CHANCE THUNDER TO THE WI BORDER AND JUST HAVE
SLIGHT CHANCE OVER ALL BUT THE FAR N.
AT THE PRESENT TIME...FEEL FAIRLY CONFIDENT IN THE GOING FORECAST.
ONLY HAVE TWO CONCERNS. ONE...IF THE CONVECTION CURRENTLY GOING IN
NCNTRL SD CAN STAY ON THE INSTABILITY GRADIENT AND HOLD OFF THE
STEERING FROM THE RIDGE...WHICH DOESN/T SEEM TOO LIKELY.
TWO...WOULD BE IF CONVECTION THAT MAY FIRE ALONG THE WARM FRONT AND
INSTABILITY GRADIENT IN CNTRL MN AND NW WI THIS AFTN...WHICH COULD
DISRUPT SOME OF THE LLVL FLOW AND MOISTURE ADVECTION INTO THIS
AREA. BUT WITH THE WAY THE CONVECTION AND SHOWERS HAVE BEEN GOING
IN THE DAKOTAS...FEEL THAT MUCH OF THE AREA WOULD STILL SEE RAIN
IF THAT OCCURS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 514 AM EDT FRI JUL 6 2012
SATURDAY...HIGH PRESSURE AND STRONG DRYING BEHIND THE FRONT SAGGING
TO THE SOUTH WILL BRING CLEARING SKIES AFTER ANY ANY LEFTOVER LIGHT
SHOWERS OVER THE SOUTH EARLY. MAX READINGS SHOULD ALSO BE LOWER WITH
INLAND READINGS IN THE UPPER 70S AND LOWER 80S AS 850 MB TEMPS DROP
INTO THE 12C TO 14C RANGE. LIGHT NRLY GRADIENT FLOW WILL KEEP TEMPS
MAINLY IN THE LOWER 70S NEAR LAKE SUPERIOR. WITH DEWPOINTS DROPPING
INTO THE 50S...FAVORABLE RADIAIONAL COOLING CONDITIOINS SHOULD ALLOW
TEMPS TO DROP INTO THE LOWER TO MID 50S INLAND.
SUNDAY...THE COMBINATION OF A WEAK SHORTWAVE DROPPING INTO THE AREA
IN THE NW FLOW PATTERN AND SBCAPE VALUES INTO THE 400-600 J/KG RANGE
DURING PEAK HEATING MAY BE ENOUGH TO TRIGGER SOME ISOLD INLAND
SHRA/TSRA OVER THE INTERIOR WEST. HOWEVER...ANY RAINFALL AMOUNTS
WOULD BE LIGHT. EVEN THOUGH SEVERAL MODELS SUGGEST THAT ANOTHER WEAK
SHORTWAVE SUNDAY NIGHT MAY ALSO PRODUCE SOME LIGHT SHOWERS...GIVEN
THE GENERALLY DRY AIRMASS...PREFERRED THE ECMWF WHICH DOES NOT SHOW
ANY QPF.
MONDAY THROUGH THURSDAY...A MORE AMPLIFIED PATTERN WITH A MID/UPPER
LEVEL RIDGE OVER WRN NOAM WILL RESULT IN CONTINUED NW FLOW THROUGH
THE WRN GREAT LAKES. THE POTENTIAL ALSO REMAINS FOR WEAK SHORTWAVES
TO MOVE THROUGH THE AREA WITH LOWER END PCPN CHANCES.
HOWEVER...CONFIDENCE IN THE TIMING/STRENGTH OF THESE FEATURES IS
LOW. CONTINUED TO FAVOR THE DRIER ECMWF QPF...GIVEN THE GFS MOISTURE
BIAS. TEMPERATURES WILL REMAIN CLOSER TO SEASONAL AVERAGES WITH HIGHS
IN THE LOW TO MID 70S MON CLIMBING TO THE UPPER 70S AND LOWER 80S BY
WED-THU.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 130 AM EDT FRI JUL 6 2012
DRIER AIRMASS HAS SETTLED OVER THE AREA AHEAD OF WEAK HIGH PRES
DRIFTING TOWARD THE UPPER GREAT LAKES. RESULT WILL BE VFR CONDITIONS
AT KIWD/KCMX/KSAW THRU THIS AFTN. APPROACHING DISTURBANCE WILL BRING
THICKENING MID CLOUDS TODAY...AND SHRA COULD SPREAD INTO WESTERN
UPPER MI...KIWD IN PARTICULAR...LATER IN THE AFTN. MDT TO POSSIBLY
HVY SHRA WILL THEN OVERSPREAD THE AREA THIS EVENING WITH THE HEAVIER
RAINFALL MORE LIKELY AT KIWD/KSAW. CONDITIONS AT KIWD/KSAW SHOULD
FALL TO MVFR AND POSSIBLY TO IFR. WHILE TSRA WILL BE MORE LIKELY
JUST TO THE S...THE NRN EDGE OF THE INSTABILITY GRADIENT CERTAINLY
COULD SUPPORT TSRA AT KIWD/KSAW TONIGHT...BUT HAVE HELD OFF ON
MENTION UNTIL THERE IS INCREASED CONFIDENCE FOR TSRA TO OCCUR.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 514 AM EDT FRI JUL 6 2012(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 433 PM EDT THU JUL 5 2012
A LOW PRESSURE TROUGH MOVING ACROSS LAKE SUPERIOR REST OF THE AFTN
WILL RESULT IN WINDS BECOMING MORE WEST-NORTHWEST INTO TONIGHT.
GUSTS AT HIGHER PLATFORMS THROUGH THE NIGHT MAY PUSH 20-25 KTS...
BUT OTHERWISE WILL BE 10-20 KTS. HIGH PRESSURE THEN MOVES OVER
THE UPPER GREAT LAKES TONIGHT AHEAD OF ANOTHER SFC TROUGH MOVING
THROUGH NORTHERN WI ON FRIDAY NIGHT. AS THE TROUGH SLIDES SOUTH ON
SATURDAY...HIGH PRESSURE WILL BUILD OVER THE UPPER GREAT LAKES
AND REMAIN THROUGH THE FIRST PART OF NEXT WEEK. WINDS SHOULD
REMAIN BELOW 20 KTS THROUGH THE PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...JLB
AVIATION...ROLFSON
MARINE...SRF
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
146 AM EDT FRI JUL 6 2012
.SYNOPSIS...
BERMUDA HIGH PRESSURE OFFSHORE AND THE PIEDMONT TROUGH INLAND WILL
PREVAIL THROUGH MUCH OF THE FORECAST PERIOD...BRINGING HOT AND HUMID
CONDITIONS WITH A CHANCE FOR THUNDERSTORMS EACH AFTERNOON AND
EVENING. AN UPPER RIDGE OVER THE AREA WILL SLOWLY WEAKEN NEXT
WEEK...BRINGING DAYTIME TEMPERATURES CLOSER TO NORMAL FOR JULY. AN
APPROACHING COLD FRONT WILL STALL NEAR THE AREA BEGINNING TUESDAY...
AND THIS WILL INCREASE THE PROBABILITY OF SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 1030 PM THURSDAY...WATER VAPOR IMAGERY COMBINED WITH SURFACE
ANALYSIS PAINTS THE PICTURE TONIGHT...WITH SURFACE HIGH PRESSURE
SINKING SOUTH ACROSS EASTERN TENNESSEE AND A LARGE UPPER RIDGE
HOLDING FIRM ACROSS THE MIDWEST. AT THE SAME TIME...SOUTHWEST
MONSOON MOISTURE IS WRAPPING UP ALONG THE WESTERN EDGE OF THE RIDGE
IN NM/CO...AND ROTATING BACK DOWN THE EASTERN PERIPHERY IN THE
APPALACHIANS...HELPING TO FUEL OUR STORMS TONIGHT.
ADDITIONALLY...S/SW RETURN FLOW AROUND OFFSHORE BERMUDA HIGH HAS
HELPED DRIVE DEWPOINTS WELL INTO THE 70S MOST LOCATIONS.
AS EXPECTED...CONVECTION FROM EARLIER HAS SLOWLY BEGUN TO WANE
THANKS TO LOSS OF HEATING. HOWEVER...THE ELEVATED INSTABILITY AND
STRONGLY-NEGATIVE LI`S AS SHOWN ON BOTH NAM AND RUC FORECAST
PROFILES CONTINUE TO BE TAPPED BY RESIDUAL OUTFLOWS/BOUNDARIES...IN
CONJUNCTION WITH UPPER IMPULSE NOW ROTATING OFF TO THE SOUTHWEST.
LATEST SPC RUC ANALYSIS SHOWS CONVECTION IS NOW CAPPED TO BOTH
SURFACE BASED...AND MIXED LEVEL PARCELS...WITH LPL HEIGHTS OF
500-1000M NOW REQUIRED TO GAIN INSTABILITY. STILL...CONVECTION WILL
PERSIST...IN A LIMITED/ISOLATED FORM...FOR A FEW MORE HOURS BEFORE
DISSIPATING ENTIRELY AFTER MIDNIGHT. THIS CONVECTION SHOULD REMAIN
RATHER SHALLOW HOWEVER...EVIDENCED BY DRY AIR ABOVE 600MB IN
FORECAST SOUNDINGS...SO EVEN LIGHTNING WILL BE DIFFICULT TO COME BY
THE REST OF THE NIGHT. HRRR FINALLY COMING INTO AGREEMENT WITH THE
FAVORED ARW...WHICH AGREES WITH ONGOING FORECAST OF POP DECREASING
TO SILENT BY 2AM.
AS SURFACE HIGH DRIFTS SOUTH NEAR TENNESSEE...A DECENT LLJ OF 25-30
KTS WILL DEVELOP ABOVE THE NOCTURNAL INVERSION. THIS WILL WORK IN
TANDEM WITH SOME MID/HIGH LEVEL CLOUD COVER TO KEEP TEMPS FROM
FALLING TOO MUCH TONIGHT. HAVE LEANED MORE TOWARDS THE WARMER NAM
GUIDANCE...WITH LOWS IN THE MID 70S INLAND...TO NEAR 80 AT THE
IMMEDIATE COAST.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...MID/UPPER LEVEL RIDGE OVER THE CENTRAL
CONUS ON FRIDAY WILL FLATTEN AND SPREAD EASTWARD ON SATURDAY...
WITH INCREASING HEIGHTS OVER THE CWA THROUGH THE PERIOD. TIME-
HEIGHT CROSS SECTIONS SHOW A LAYER OF RELATIVELY DRY AIR BETWEEN
700-400 MB...WITH ONLY MODEST MOISTURE BELOW 700 MB. A DEEP LAYER
OF SUBSIDENCE IS ALSO NOTED IN RESPONSE TO THE INCREASING HEIGHTS.
ALTHOUGH DEEP MOISTURE IS LACKING...SURFACE DEWPOINTS IN THE MID
70S COMBINED WITH SB CAPE TO 2500 J/KG AND LI`S TO -6 WILL MAKE IT
TOUGH TO RULE OUT THE CHANCE FOR CONVECTION ALTOGETHER. ISOLATED
DEVELOPMENT WILL BE POSSIBLE FRIDAY AND SATURDAY ALONG THE SEA
BREEZE AND PIEDMONT TROUGH...BUT EXPECT CHANCES TO BE HIGHER
FRIDAY AS A SUBTLE MID-LEVEL SHORTWAVE DROPS SOUTH ACROSS THE
AREA DURING MIDDAY HEATING. ALSO NOTABLE LATE FRIDAY NIGHT AND
THROUGH SATURDAY IS DEEP ONSHORE FLOW ABOVE 700 MB. ANY CONVECTION
THAT DEVELOPS OVER THE WATERS WILL BE STEERED TOWARDS SHORE.
GIVEN WIDESPREAD HIGHS EXPECTED TO BE IN THE MID AND UPPER
90S FRIDAY AND SATURDAY...AND DEWPOINTS IN THE MID 70S...HEAT INDICES
SHOULD REACH 105 AT MANY LOCATIONS. THEREFORE WILL RAISE ANOTHER
HEAT ADVISORY FOR FRIDAY...AND ONE MAY BE REQUIRED FOR SATURDAY ALSO.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...SUNDAY SHOULD BE THE LAST DAY OF EXTREME
HEAT. HIGH TEMPERATURES IN THE UPPER 90S AWAY FROM THE COAST COUPLED
WITH MID-70S DEWPOINTS SHOULD AGAIN YIELD HEAT INDICES ABOVE 105
DEGREES DURING THE DAY. THE HOT UPPER LEVEL RIDGE CAUSING THE HEAT
THIS WEEKEND WILL PASS VIRTUALLY OVERHEAD SUNDAY...THEN OFFSHORE
MONDAY. THIS WILL SHIFT THE DEEP-LAYER FLOW AROUND TO THE SOUTH ON
MONDAY... WITH DECREASING 850 MB TEMPS AND 1000-500 MB THICKNESSES
SHOWN ON GFS/ECMWF MODEL PLOTS. MONDAY`S HIGHS SHOULD THEREFORE RUN
A FEW DEGREES COOLER THAN ON SUNDAY. COOLING AND MOISTENING
MID-LEVELS SHOULD FAVOR BETTER A LITTLE CONVECTIVE POTENTIAL MONDAY
AS WELL.
BY TUESDAY THE PATTERN BECOMES EVEN MORE FAVORABLE FOR CONVECTION AS
A SYNOPTIC SURFACE FRONT DROPS SOUTH INTO THE CAROLINAS AND DEEP
MOISTURE INCREASES ALOFT AHEAD OF A DEVELOPING LONGWAVE TROUGH
EXTENDING FROM THE GREAT LAKES DOWN TO THE GULF COAST. GFS AND ECMWF
FORECAST SOUNDINGS SHOW AN UNCAPPED TROPICAL AIRMASS WITH SLIGHTLY
STEEPER THAN MOIST-ADIABATIC LAPSE RATES PERSISTING FOR SEVERAL DAYS
THIS WEEK...WITH PRECIP WATER INCREASING TO NEAR 2.0 INCHES. WE`VE
INCREASED THE AREA OF 40-50 PERCENT 12-HR POPS FORECAST TUESDAY
THROUGH THURSDAY AS THIS PATTERN CERTAINLY SHOULD EXCEED THE
CLIMATOLOGICAL 20-30 PERCENT 12-HR POP FOR THIS TIME OF YEAR.
UNIDIRECTIONAL SOUTH-SOUTHWEST WINDS AND MODEST LAPSE RATES WILL
SUPPORT HEAVY RAINFALL BUT NOT NECESSARILY SEVERE WEATHER.
DIURNAL TEMPERATURE RANGES WILL BECOME CONSTRICTED TUESDAY THROUGH
THURSDAY BY THE ADDITIONAL CLOUDS AND PRECIP...WITH HIGHS AVERAGING
IN THE UPPER 80S. LOWS SHOULD RANGE FROM 70-75.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 06Z...EXPECT VFR THROUGH THE VALID PERIOD WITH THE EXCEPTION
OF POSSIBLE BRIEF MVFR DUE TO PATCHY FOG AT KLBT THROUGH SUNRISE AND
IN ANY CONVECTION THIS AFTERNOON.
AFTER AN EVENING OF ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS...ANTICIPATE HIGH-LEVEL CLOUD DEBRIS TO LINGER ACROSS
THE AREA WITH SOUTH-SOUTHWEST WINDS AOB 10 KTS. EXPECT LOW LEVEL
JETTING TO INHIBIT FOG FORMATION. HOWEVER...CANNOT COMPLETELY RULE
OUT BRIEF MVFR FOG DURING THE EARLY MORNING HOURS AT KLBT WHERE
DECENT RAIN FELL THIS EVENING.
AFTER DAYBREAK...SOUTHWEST WINDS WILL CONTINUE AND INCREASE
THROUGHOUT THE DAY TO AOB 10 KTS WITH GUSTS 15 KTS POSSIBLE ALONG
THE COAST. CANNOT RULE OUT ISOLATED TO SCATTERED CONVECTION DURING
THE AFTERNOON AND EVENING HOURS...THUS HAVE INTRODUCED VCTS.
CONVECTION WILL LIKELY TREND AS IT HAS THE PAST FEW DAYS...LINGERING
INTO THE LATE EVENING HOURS. SCT CLOUD DEBRIS WILL CONTINUE INTO THE
OVERNIGHT HOURS WITH SOUTHWEST WINDS AOB 8 KTS.
EXTENDED OUTLOOK...A CHANCE OF THUNDERSTORMS EACH DAY...MAINLY IN
THE AFTERNOON AND EVENING. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM THURSDAY...SW FLOW AROUND BERMUDA HIGH OF 10-20 KTS
PERSISTING ACROSS THE COASTAL WATERS...WITH BUOYS REPORTING SEAS OF
3-4 FT. GUIDANCE STILL SHOWING THE DEVELOPMENT OF A STRONG LOW LEVEL
JET TONIGHT AS HIGH PRESSURE SINKS SOUTH ACROSS TENNESSEE. THIS
COULD ENHANCE WINDS ACROSS THE WATERS. HOWEVER...TEMPS 1200-1500 FT
ABOVE THE SURFACE SHOULD BE WARM ENOUGH THAT A WEAK INVERSION WILL
DEVELOP EVEN ACROSS THE WATERS (WATER TEMPS IN THE UPPER 70S ATTM)
SO FULL DOWNWARD MIXING IS NOT ANTICIPATED...AND WINDS/SEAS SHOULD
REMAIN BELOW ANY CAUTIONARY HEADLINE CRITERIA. FOR THIS REASON
EXPECT STATUS QUO...3-4 FT SEAS AND 10-20 KTS SW WINDS CONTINUING
THROUGH DAYBREAK...ALTHOUGH AN ISOLATED 5 FTER IS NOT OUT OF THE
QUESTION NEAR THE 20NM BOUNDARY.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...SOUTHWEST FLOW WILL PERSIST OVER THE WATERS
THROUGH THE PERIOD BETWEEN A SURFACE TROUGH LOCATED OVER THE
INLAND CAROLINAS AND BERMUDA HIGH PRESSURE. THE MSLP GRADIENT
MAGNITUDE WILL INCREASE EACH AFTERNOON IN RESPONSE TO THE SEA
BREEZE.
LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 3 PM THURSDAY...HIGH PRESSURE WELL OFF THE U.S. EAST COAST
SHOULD CONTINUE TO PUMP A WARM AND HUMID AIRMASS ONSHORE THROUGH
EARLY NEXT WEEK. THE PIEDMONT TROUGH SUNDAY WILL BECOME REPLACED ON
MONDAY BY LOW PRESSURE ALONG A COLD FRONT DIPPING SOUTH FROM
VIRGINIA. THIS FRONT SHOULD REMAIN NORTH OF THE COASTAL WATERS...BUT
MAY GET CLOSE ENOUGH TO BRING INCREASING CHANCES OF SHOWERS AND
THUNDERSTORMS MONDAY INTO TUESDAY. OTHERWISE...SOUTHWEST WINDS 10-15
KNOTS MAY INCREASE TO NEAR 20 KNOTS NEARSHORE DURING THE AFTERNOONS
DUE TO THE SEA BREEZE CIRCULATION. SEAS SHOULD AVERAGE 2-4 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...HEAT ADVISORY FROM NOON TO 8 PM EDT FRIDAY FOR SCZ017-023-024-
032-033-039-053>056.
NC...HEAT ADVISORY FROM NOON TO 8 PM EDT FRIDAY FOR NCZ087-096-099-
105>110.
MARINE...NONE.
&&
$$
NEAR TERM...JDW
SHORT TERM...CRM
LONG TERM...TRA
AVIATION...SGL/RJD
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1233 AM CDT FRI JUL 6 2012
.UPDATE...
SEE UPDATED AVIATION DISCUSSION BELOW.
NOT PLANNING ON ANY MAJOR CHANGES TO THE FORECAST THIS EVENING.
LATEST RUNS OF THE 3KM HRRR STILL MAINTAIN THAT AN MCS WILL ROLL
ACROSS THE NORTHWEST AND FAR NORTHERN CWA OVERNIGHT INTO FRIDAY
MORNING. DONT HAVE A REAL PROBLEM WITH THIS AS ITS CONSISTENT WITH
OTHER LOWER RESOLUTION MODEL DATA. THEREFORE WILL MAINTAIN HIGH
POPS OVERNIGHT. TEMPERATURES LOOK FINE FOR NOW.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TONIGHT THROUGH SUNDAY MORNING.
MAIN FCST CHALLENGE FACING THE NEAR TERM REVOLVES AROUND PCPN CHCS
FOR TONIGHT THROUGH FRIDAY MORNING.
LATEST 88D IMAGERY SHOWS EXPANDING AREA OF LIGHT -SHRA FROM MURDO
TO PLANKINTON...WITH NEW ACTIVITY NEAR HIGHMORE AND WATERTOWN.
AREA COINCIDES WITH MOISTURE RETURNING NORTHWARD COUPLED WITH
INCREASING FORCING NOTED ON THE 310K AND 315K ISENTROPIC LAYERS.
ISEN ANALYSIS ALSO REFLECTED POCKET OF DRIER AIR ACROSS NERN
SD...EVIDENCED BY DEWPTS ALONG THE HIGHWAY 12 CORRIDOR FROM MBG TO
K8D3 REMAINING IN THE MID 40S TO NEAR 50. CONVERSELY DWPTS IN THE
KHON AND KBKX AREA ARE IN THE MID 70S. HRR MODEL AND LOCAL 4KM WRF
MODEL ALL SHOW THIS ACTIVITY SLIDING EAST ALONG THE HIGHWAYS 14
AND 212 CORRIDORS...WITH NOT MUCH MOVING NORTHWARD INTO DRIER AIR
IN PLACE ACROSS THE NORTHEAST.
ATTENTION THEN TURNS TOWARD THE OVERNIGHT PERIOD...AS LOW PRESSURE
DEVELOPS ACROSS EASTERN WY AND MOVING TO THE KPIR AREA BY 12Z
FRIDAY. WAA AHEAD OF DEVELOPING LOW PUSHES 700HPA TEMPS TO ABOVE
12C ACROSS MUCH OF THE EASTERN CWA. 850HPA 30KT TO 40KT JET LIFTS
WARMFRONT INTO SRN ND...AND MAJORITY OF MODELS SHOW ND WILL
RECEIVE BULK OF PCPN WITH THIS SYSTEM. AM HESITANT TO MENTION SVR
ATTM AS INCREDIBLY HIGH FREEZING LEVELS EXIST ACROSS CWA. ALTHOUGH
DRIER MID LEVELS COULD LEAD TO MORE OF A WIND THREAT.
BY FRIDAY AFTERNOON...LOW SAGS BACK TO THE SE...WITH WEAK CAA
FILLING IN ACROSS THE CWA. SOME LINGERING -SHRA/-TSRA COULD EXIST
DURING THE DAY ACROSS THE EASTERN CWA...BUT AGAIN BULK OF PCPN
APPEARS TO RESIDE IN ND AND WESTERN MN.
REMAINDER OF SHORT TERM LOOKS TO BE QUIET AND RELATIVELY COOL
(WHEN COMPARED TO PREVIOUS HIGHS) AS 850HPA TEMPS FALL BACK INTO
THE TEENS FOR THE WEEKEND.
.LONG TERM...SUNDAY THROUGH THURSDAY
A STRONG UPPER LEVEL RIDGE IS THE MAIN WEATHER FEATURE DURING THE
EXTENDED PERIOD. MODELS SHOW THIS RIDGE SETTING UP ACROSS THE
ROCKIES/HIGH PLAINS WITH NOT MUCH IN THE WAY OF RAINFALL CHANCES
OVER THE NORTHERN PLAINS. EXTENDED PERIOD REMAINS DRY AT THIS
POINT WITH WARM TEMPERATURES PERSISTING. AT THE SURFACE...MODELS
ARE SHOWING A SURFACE HIGH SLOWLY SLIDING EAST-SOUTHEAST ACROSS
THE NORTHERN PLAINS AND INTO THE WESTERN GREAT LAKES. HIGH TEMPS
THROUGHOUT THE PERIOD LOOK TO BE IN THE 80S AND 90S...WITH THE
WARMER READINGS ACROSS WESTERN AND CENTRAL SOUTH DAKOTA.
&&
.AVIATION...
06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
OVERALL VFR CONDITIONS ARE EXPECTED AT ALL TAF LOCATIONS THROUGH
THE NIGHT. HOWEVER STORMS WILL BE POSSIBLE...ESPECIALLY AT KMBG
AND KABR LATE TNT. ANY STORMS COULD DROP CONDITIONS INTO THE IFR
CATEGORY BOTH CIGS AND VSBYS. THE STORMS WILL LINGER INTO THE
MORNING HOURS ON FRIDAY AT KABR BEFORE MOVING OFF TO THE EAST.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...WISE
SHORT TERM...HINTZ
LONG TERM...TMT
AVIATION...WISE
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS DENVER CO
440 AM MDT FRI JUL 6 2012
.SHORT TERM...THE BROAD UPPER HIGH CONTINUES TO MEANDER AROUND THE
CENTRAL PLAINS STATES WITH A RESULTING MOIST SOUTHERLY FLOW ALOFT
ACROSS COLORADO. WATER VAPOR IMAGERY SHOWING THE PLUME OF MOISTURE
IS WELL ESTABLISHED ACROSS CENTRAL AND WESTERN PORTIONS OF
COLORADO...WHILE DRIER AIR IS STILL HOLDING ACROSS FAR EASTERN
COLORADO. PRECIPITABLE WATER VALUES FROM GPS ARE OVER AN INCH
ACROSS MUCH OF THE AREA THIS MORNING. AT THE SURFACE...DEWPOINTS
ARE IN THE 50S ACROSS MUCH OF THE PLAINS WITH THE SURFACE TROF
ACROSS MUCH OF EASTERN COLORADO. HARD TO TELL WHERE THE FRONTAL
BOUNDARY IS AT THIS TIME WITH VERY LITTLE PRESSURE RISE REFLECTION
ACROSS WYOMING. MODELS STILL SHOWING WEAK UPSLOPE FLOW DEVELOPING
THIS MORNING THOUGH IT WILL BE SHALLOW. HARD TO REALLY MAKE MANY
CHANGES IN THIS UPCOMING FORECAST PACKAGE WITH THE TREND FOR
HIGHER CHANCES OF STORMS AND COOLING TEMPERATURES STILL LOOK ON
TRACK. HOWEVER STILL A LITTLE SUSPECT OF MODEL DEPICTION OF TOO
MUCH LOW LEVEL MOISTURE...ESPECIALLY SINCE THEY HAVE BEEN
CONSISTENTLY TOO WET FROM THE PAST FEW DAYS AS COMPARED TO
REALITY. LATEST LOOK AT THE HRRR ACTUALLY DROPS DEWPOINTS INTO THE
LOWER 40S OVER THE FRONT RANGE WHICH WOULD CUT DOWN ON THE
INSTABILITY. BEST CHANCES FOR STORMS AGAIN MOUNTAINS...FOOTHILLS
AND SEEPING OUT ONTO THE ADJACENT PLAINS. LOWER POPS FURTHER EAST
IN THE DRIER AIR.
.LONG TERM...SOUTHERLY FLOW ON THE WESTERN EDGE OF TALL UPPER
RIDGE OVER THE GREAT PLAINS WILL CONTINUE TO ADVECT AMPLE AMOUNTS
OF MOIST SUBTROPICAL AIR UP OVER COLORADO DURING THE UPCOMING WEEKEND.
IN ADDITION..A PERSISTENT EASTERLY LOW-LEVEL FLOW ON THE PLAINS
WILL CONTINUE TO PUSH MOIST BOUNDARY LAYER AIR UPSLOPE. WITH MEAN
LAYER SPECIFIC HUMIDITIES IN THE 6-8 G/KG RANGE AND PRECIPITABLE
WATER VALUES IN THE 1 TO 1.5 INCH RANGE...CHANCES ARE GOOD WE/LL
SEE PERIODS OF MEASURABLE RAINFALL FROM THUNDERSTORMS AT LEAST
MONDAY MORNING. THE BEST CHANCE FOR THIS PRECIP APPEARS TO BE LATE
SATURDAY AFTERNOON AND OVERNIGHT AND SUNDAY AFTERNOON AND EVENING...
...AND PARTICULARLY OVER AND ALONG THE FRONT RANGE WHERE MODEL
QPF FIELDS INDICATE PRETTY IMPRESSIVE RAIN TOTALS BY MONDAY. AS
WAS NOTED ABOVE IN THE SHORT TERM DISCUSSION...MODELS ESPLY THE
GFS HAVE BEEN OVER DOING QPF AMOUNTS AND ATMOSPHERIC MOISTURE FOR
SOME TIME NOW. WITH THAT IN MIND...KEPT PRECIP AMOUNTS IN THE
FCST GRIDS BELOW VALUES OFFERED BY THE MODELS...HOWEVER WILL HANG
ONTO THE 40-50 PCT POPS ON THE PLAINS AND WESTERN VALLEYS AND
LIKELY POPS AT MTN LOCATIONS PRETTY MUCH FOR THE ENTIRE WEEKEND.
FURTHERMORE...MOIST UPSLOPE FLOW...WIDESPREAD CLOUD COVER AND
PERIODS OF PRECIP WILL HAVE A BIG INFLUENCE ON TEMPERATURES THIS
WEEKEND. MODEL TEMPERATURES GUIDANCE GENERALLY INDICATING HIGHS IN
THE 70S AT LOWER ELEVATIONS AND 50-60S IN THE HIGH COUNTRY. CAN/T
ARGUE WITH THAT...ALTHOUGH TEMPERATURES OFFERED BY THE GFS APPEAR
TOO COOL EVEN WITH ALL OF THE CLOUD COVER ANTICIPATED.
BY EARLY NEXT WEEK...THE UPPER RIDGE WOBBLING OVER THE CENTRAL
GREAT PLAINS IS FORECAST TO SHIFT WESTWARD OVER THE CENTRAL ROCKY
MTN REGION LATE IN THE WEEKEND AND BECOME CENTERED OVER THE EASTERN
GREAT BASIN BY MONDAY. THIS CAUSES WINDS ALOFT..ALBEIT IT LIGHT
WINDS...TO REVERSE AND COME FROM A NORTHERLY DIRECTION OVER THE
FORECAST AREA...CONSEQUENTLY CAUSING THE MONSOON MOISTURE PLUME
TO DIVERT WESTWARD OVER THE DESERT SOUTHWEST AND GREAT BASIN
REGIONS. HOWEVER DO NOT EXPECT TO SEE A COMPLETE SHUT OFF OF THIS
SUBTROPICAL MOISTURE UNTIL TUESDSAY OR WEDNESDAY. THEREFORE STRONG
DAYTIME HEATING SHOULD CONTINUE TO BUBBLE UP THE LAST OF THIS
MONSOONAL MOISTURE INTO SCATTERED AFTERNOON AND EVENING
THUNDERSTORMS...MAINLY OVER AND NEAR THE MTNS EARLY NEXT WEEK.
SHOULD ALSO SEE A GRADUAL RAISE IN TEMPERATURES NEXT WEEK...WITH
90 DEG READINGS RETURNING TO THE PLAINS BY WEDNESDAY OR THURSDAY
WITH THE UPPER RIDGE BUILDING BACK OVER COLORADO.
&&
.AVIATION...LITTLE CHANGE ANTICIPATED FOR 12Z ISSUANCES WITH BEST
CHANCE FOR STORMS FROM MID AFTERNOON THROUGH THE EVENING HOURS AND
THEN SOME LINGERING SHOWER ACTIVITY THROUGH THE NIGHT. AMOUNT OF
TEMPO CONDITIONS MAY BE OVERDONE IN TERMS OF OVERALL THUNDERSTORM
COVERAGE BUT HARD TO REALLY CUT THINGS DOWN TOO MUCH UNTIL THE
REALITY OF HOW MUCH MOISTURE IS REALLY OUT THERE. SURFACE WINDS
WILL GRADUALLY TREND TO THE NORTHEAST BUT NOT A REAL STRONG
FRONTAL BOUNDARY EXPECTED THIS MORNING.
&&
.HYDROLOGY...GIVEN SOME OF THE SUSPECT MOISTURE VALUES IN THE MODELS AM
RELUCTANT ON ANY FLASH FLOOD WATCHES AT THIS TIME. STORMS WILL STILL
BE MOVING AT 10-15KT BUT STORM TRAINING STILL A POSSIBILITY. BURN
SCARS WILL CERTAINLY NEED TO BE WATCHED BUT OVERALL FLOODING
THREAT WILL BE MORE LOCALIZED AND LIMITED TO THE BURN AREAS.
CERTAINLY HEAVY RAIN CAN BE EXPECTED WITH THE STORMS AND RAINFALL
RATES WILL BE OVER AN INCH IN 30 MINUTES WITH THE STRONGER STORMS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ENTREKIN
LONG TERM....BAKER
AVIATION...ENTREKIN
AREA FORECAST DISCUSSION
NWS CARIBOU ME
916 AM EDT FRI JUL 6 2012
.SYNOPSIS...
HIGH PRESSURE WILL MOVE EAST OF THE AREA TODAY. A COLD FRONT WILL
APPROACH LATER TODAY AND CROSS THE REGION TONIGHT. ANOTHER COLD
FRONT WILL CROSS THE REGION SATURDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
915 AM UPDATE...NO MAJOR CHANGES NEEDED FOR THIS UPDATE. SATELLITE
IS SHOWING MAINLY PARTLY SUNNY SKIES ACROSS THE CWA THIS MORNING,
AND THIS SHOULD CONTINUE INTO THIS AFTERNOON. EXPECT QUIET WEATHER
THROUGH MID AFTERNOON, WITH ANY SHOWERS AND THUNDERSTORMS HOLDING
OFF UNTIL LATE. THE GOING FORECAST HAS THIS COVERED, SO NO OTHER
CHANGES NEEDED OTHER THAN SLIGHT ADJUSTMENTS TO SKY COVER.
PREVIOUS DISCUSSION:
CHALLENGE THIS TERM WILL BE CLOUDS/FOG THIS MORNING AND
CONVECTION LATER TODAY INTO TONIGHT.
THE LATEST IR SATL IMAGERY SHOWING LOW CLOUDS/FOG DEVELOPING AND MOVING
ACROSS THE AREA. THE HRRR WAS HANDLING THIS SET QUITE WELL AND
FOLLOWED W/IT THROUGH THE MORNING HRS. THIS MEANS CLOUDS AND AREAS
OF FOG ACROSS AT LEAST 1/2 OF THE CWA, BUT AS MORNING WEARS ON AND
SUN BEGINS TO WORK ON THE ATMOSPHERE, CLOUDS SHOULD BREAK UP
W/SKIES BECOMING PARTLY TO MOSTLY SUNNY. THIS WILL ALLOW
TEMPERATURES TO RESPOND ACCORDINGLY W/TEMPERATURES MAXING OUT IN
THE 80 FOR THE CWA W/THE EXCEPTION OF THE COAST AS A SEA BREEZE
DEVELOPING THIS AFTERNOON WILL ALLOW FOR COOLER TEMPERATURES RIGHT
AT THE COAST. NOT CONFIDENT ENOUGH TO BRING THE SEA BREEZE FURTHER
INLAND TOWARD THE BANGOR REGION AND DECIDED TO HAVE WARMER
TEMPERATURES THERE.
IN REGARDS TO CONVECTION, THE ATMOSPHERE LOOKS LIKE IT WILL
DESTABILIZE THIS AFTERNOON THANKS IN PART TO HEATING. MDL
SOUNDINGS ESPECIALLY THE NAM RAMP UP THE SBCAPES TO 800-1200
JOULES ACROSS THE NORTH AND WEST. LIS DROP TO -2 TO -5 W/K INDICES
OF 30+. 0-6KM BULK SHEAR IS 30+ KTS. INHIBITING FACTORS ARE DEEP
MOISTURE WHICH ATTM APPEARS TO BE LIMITED TO BELOW 700 MBS AND
LOW/MID LEVEL LAPSE RATES <6.5C/KM. SOME MID LEVEL WARMING WILL
INHIBIT INITATION, BUT THERE DOES APPEAR TO BE SOME COOLING AROUND
00Z AND A MID/UPPER LEVEL SPEED MAX OF 40-50 KTS AS A COLD FRONT
MOVES IN FROM THE WEST. THIS SPEED MAX COULD OFFSET THE WEAKER
LAPSE RATES AND ALLOW FOR CONVECTION W/SOME STORMS TO BE STRONG TO
POSSIBLY SEVERE. WIND LOOKS TO BE THE MAIN THREAT AS FREEZING
LEVELS ARE SHOWN TO BE AT 13+K FT. ANOTHER THING TO NOTE IS THAT
THERE IS DECENT DIRECTIONAL SHEAR IN LLVL WHICH COULD ALLOW FOR
SOME ROTATION IF STRONGER STORMS FIRE. COLLABORATED W/GYX AND SPC
ON THIS POTENTIAL AND THINKING ATTM ANY SEVERITY WILL BE ISOLD AND
KEPT ACROSS THE NORTH AND WEST. THIS WILL NEED TO BE ASSESSED BY
THE DAYCREW. ACTIVITY WILL MOVE TO THE EAST TONIGHT AND WEAKEN AS
FORCING LESSENS W/LEFTOVER SHOWERS. BOOSTED OVERNIGHT MINS USING
THE NAM12 TEMPERATURES.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
A 500 MB LOW WILL REMAIN ACROSS EASTERN QUEBEC THROUGH SUNDAY WITH
WEST TO NORTHWEST FLOW ALOFT CONTINUING THROUGH SUNDAY. THIS WILL
ALLOW A SERIES OF WEAK COLD FRONT TO CROSS THE REGION THROUGH
SUNDAY. THIS WILL BRING THE CHANCE FOR SHOWERS AND THUNDERSTORMS
TO THE REGION ON SATURDAY WITH ONLY AN ISOLATED SHOWER OR
THUNDERSTORM ON SUNDAY. HIGH TEMPERATURES ON SATURDAY WILL RANGE
FRROM THE LOW 80S NORTH AND MID 80S DOWNEAST. HIGHS ON SUNDAY WILL
RANGE FROM THE LOWER 70S NORTH AND MID 70S TO NEAR 80 ON SUNDAY.
LOW SATURDAY NIGHT WILL RANGE FROM THE MID 50S NORTH AND UPPER 60S
DOWNEAST.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
A MAINLY ZONAL FLOW ALOFT WILL PERSIST THROUGH THE MIDWEEK PERIOD.
THIS WILL BRING MAINLY DRY WEATHER TO THE REGION. TEMPERATURES
THROUGH THE PERIOD WILL BE NEAR NORMAL.
&&
.AVIATION /13Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: IFR/MVFR ACROSS THE NORTHERN TERMINALS THIS MORNING AND
PROJECT TO DEVELOP ACROSS KBGR/KBHB FOR A TIME THIS MORNING.
CONDITIONS ARE EXPECTED TO IMPROVE TO VFR BY MID TO LATE MORNING.
SOME CONCERN TO STRONGER TSTMS ACROSS THE NORTHERN TERMINALS LATER
THIS AFTERNOON INTO EARLY TONIGHT WHICH COULD DROP CONDITIONS TO
MVFR FOR A BRIEF TIME. LLWS COULD BE A ISSUE W/THE TSTMS.
SHORT TERM: MAINLY VFR CONDITIONS. COULD BE BRIEF MVFR IN ANY
HEAVIER CONVECTION SATURDAY AFTERNOON.
&&
.MARINE...
NEAR TERM: NO HEADLINES. SE SWELL CONTINUES AND DECIDED TO KEEP IT
GOING THROUGH TONIGHT AS 8-9 SECOND PERIOD. WAVE HEIGHTS OF 2-3 FT
INTO TONIGHT. WINDS WILL BE 10 KTS OR LESS.
SHORT TERM: WINDS/SEAS WILL REMAIN BELOW SCA LEVELS THROUGH THE
PERIOD.
&&
.MARINE...
NEAR TERM:
SHORT TERM:
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HASTINGS/HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HASTINGS/HEWITT
MARINE...HASTINGS/HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS CARIBOU ME
721 AM EDT FRI JUL 6 2012
.SYNOPSIS...
HIGH PRESSURE WILL MOVE EAST OF THE AREA TODAY. A COLD FRONT WILL
APPROACH LATER TODAY AND CROSS THE REGION TONIGHT. ANOTHER COLD
FRONT WILL CROSS THE REGION SATURDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE: MODIFIED THE SKY CONDITIONS TO PLAY FOR MORE CLOUDS OVER
THE FAR NEAR THE ST. JOHN VALLEY AND RIGHT ALONG THE MAINE/NEW
BRUNSWICK BORDER. LATEST SATL IMAGERY SHOWS SOME LLVL CLOUDS
MAKING THEIR WAY INTO THE DOWNEAST REGION. CLOUDS SHOULD DISSIPATE
AS UPPER RIDGE WORKS OVER THE AREA THIS MORNING ALLOWING FOR MORE
SUN AND HENCE WARMER TEMPERATURES. TWEAKED DAYTIME HIGHS TODAY UP
A FEW DEGREES.
PREVIOUS DISCUSSION:
CHALLENGE THIS TERM WILL BE CLOUDS/FOG THIS MORNING AND
CONVECTION LATER TODAY INTO TONIGHT.
THE LATEST IR SATL IMAGERY SHOWING LOW CLOUDS/FOG DEVELOPING AND MOVING
ACROSS THE AREA. THE HRRR WAS HANDLING THIS SET QUITE WELL AND
FOLLOWED W/IT THROUGH THE MORNING HRS. THIS MEANS CLOUDS AND AREAS
OF FOG ACROSS AT LEAST 1/2 OF THE CWA, BUT AS MORNING WEARS ON AND
SUN BEGINS TO WORK ON THE ATMOSPHERE, CLOUDS SHOULD BREAK UP
W/SKIES BECOMING PARTLY TO MOSTLY SUNNY. THIS WILL ALLOW
TEMPERATURES TO RESPOND ACCORDINGLY W/TEMPERATURES MAXING OUT IN
THE 80 FOR THE CWA W/THE EXCEPTION OF THE COAST AS A SEA BREEZE
DEVELOPING THIS AFTERNOON WILL ALLOW FOR COOLER TEMPERATURES RIGHT
AT THE COAST. NOT CONFIDENT ENOUGH TO BRING THE SEA BREEZE FURTHER
INLAND TOWARD THE BANGOR REGION AND DECIDED TO HAVE WARMER
TEMPERATURES THERE.
IN REGARDS TO CONVECTION, THE ATMOSPHERE LOOKS LIKE IT WILL
DESTABILIZE THIS AFTERNOON THANKS IN PART TO HEATING. MDL
SOUNDINGS ESPECIALLY THE NAM RAMP UP THE SBCAPES TO 800-1200
JOULES ACROSS THE NORTH AND WEST. LIS DROP TO -2 TO -5 W/K INDICES
OF 30+. 0-6KM BULK SHEAR IS 30+ KTS. INHIBITING FACTORS ARE DEEP
MOISTURE WHICH ATTM APPEARS TO BE LIMITED TO BELOW 700 MBS AND
LOW/MID LEVEL LAPSE RATES <6.5C/KM. SOME MID LEVEL WARMING WILL
INHIBIT INITATION, BUT THERE DOES APPEAR TO BE SOME COOLING AROUND
00Z AND A MID/UPPER LEVEL SPEED MAX OF 40-50 KTS AS A COLD FRONT
MOVES IN FROM THE WEST. THIS SPEED MAX COULD OFFSET THE WEAKER
LAPSE RATES AND ALLOW FOR CONVECTION W/SOME STORMS TO BE STRONG TO
POSSIBLY SEVERE. WIND LOOKS TO BE THE MAIN THREAT AS FREEZING
LEVELS ARE SHOWN TO BE AT 13+K FT. ANOTHER THING TO NOTE IS THAT
THERE IS DECENT DIRECTIONAL SHEAR IN LLVL WHICH COULD ALLOW FOR
SOME ROTATION IF STRONGER STORMS FIRE. COLLABORATED W/GYX AND SPC
ON THIS POTENTIAL AND THINKING ATTM ANY SEVERITY WILL BE ISOLD AND
KEPT ACROSS THE NORTH AND WEST. THIS WILL NEED TO BE ASSESSED BY
THE DAYCREW. ACTIVITY WILL MOVE TO THE EAST TONIGHT AND WEAKEN AS
FORCING LESSENS W/LEFTOVER SHOWERS. BOOSTED OVERNIGHT MINS USING
THE NAM12 TEMPERATURES.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
A 500 MB LOW WILL REMAIN ACROSS EASTERN QUEBEC THROUGH SUNDAY WITH
WEST TO NORTHWEST FLOW ALOFT CONTINUING THROUGH SUNDAY. THIS WILL
ALLOW A SERIES OF WEAK COLD FRONT TO CROSS THE REGION THROUGH
SUNDAY. THIS WILL BRING THE CHANCE FOR SHOWERS AND THUNDERSTORMS
TO THE REGION ON SATURDAY WITH ONLY AN ISOLATED SHOWER OR
THUNDERSTORM ON SUNDAY. HIGH TEMPERATURES ON SATURDAY WILL RANGE
FRROM THE LOW 80S NORTH AND MID 80S DOWNEAST. HIGHS ON SUNDAY WILL
RANGE FROM THE LOWER 70S NORTH AND MID 70S TO NEAR 80 ON SUNDAY.
LOW SATURDAY NIGHT WILL RANGE FROM THE MID 50S NORTH AND UPPER 60S
DOWNEAST.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
A MAINLY ZONAL FLOW ALOFT WILL PERSIST THROUGH THE MIDWEEK PERIOD.
THIS WILL BRING MAINLY DRY WEATHER TO THE REGION. TEMPERATURES
THROUGH THE PERIOD WILL BE NEAR NORMAL.
&&
.AVIATION /11Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: IFR/MVFR ACROSS THE NORTHERN TERMINALS THIS MORNING AND
PROJECT TO DEVELOP ACROSS KBGR/KBHB FOR A TIME THIS MORNING.
CONDITIONS ARE EXPECTED TO IMPROVE TO VFR BY MID TO LATE MORNING.
SOME CONCERN TO STRONGER TSTMS ACROSS THE NORTHERN TERMINALS LATER
THIS AFTERNOON INTO EARLY TONIGHT WHICH COULD DROP CONDITIONS TO
MVFR FOR A BRIEF TIME. LLWS COULD BE A ISSUE W/THE TSTMS.
SHORT TERM: MAINLY VFR CONDITIONS. COULD BE BRIEF MVFR IN ANY
HEAVIER CONVECTION SATURDAY AFTERNOON.
&&
.MARINE...
NEAR TERM: NO HEADLINES. SE SWELL CONTINUES AND DECIDED TO KEEP IT
GOING THROUGH TONIGHT AS 8-9 SECOND PERIOD. WAVE HEIGHTS OF 2-3 FT
INTO TONIGHT. WINDS WILL BE 10 KTS OR LESS.
SHORT TERM: WINDS/SEAS WILL REMAIN BELOW SCA LEVELS THROUGH THE
PERIOD.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HEWITT
MARINE...HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
734 AM EDT FRI JUL 6 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 522 AM EDT FRI JUL 6 2012
WV IMAGERY AND RUC ANALYSIS SHOWS AN UPPER RIDGE OVER THE CNTRL
CONUS AND AN UPPER LOW OVER HUDSON BAY SUPPRESSING THE NRN EXTENT
OF THE UPPER RIDGE. SHORTWAVE IN ERN MONTANA IS ROTATING NNE UP THE
RIDGE AND THE SHORTWAVE COMBINED WITH A SFC LOW IN ERN SD HAS
CONTINUED TO PRODUCE A LARGE THUNDERSTORM COMPLEX IN NCNTRL SD AND
CNTRL ND. CLOSER TO UPPER MI...SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS HAVE DEVELOPED OVER THE LAST COUPLE HOURS IN
CNTRL/NRN MN ASSOCIATED WITH H700-500 MOISTURE AND EDGE OF
EXITING 6.5-7.5 C/KM LAPSE RATES. WITH THE RIDGE IN PLACE...EXPECT
THE SHOWERS TO CONTINUE NNE EARLY THIS MORNING DUE TO THE
RIDGE...WHILE THE STEEPER LAPSE RATES SHIFT E. THIS SHOULD KEEP
PCPN MAINLY TO THE W OF LK SUPERIOR...ALTHOUGH THERE ARE SOME HINTS
OF IT TRYING TO BUILD E TOWARDS THE LK. OVER UPPER MI...HIGH
PRESSURE RIDGE IS IN PLACE AND HAS LED TO CLEAR SKIES AND
TEMPERATURES IN THE 60S.
THE HIGH PRESSURE SHOULD LEAD TO A SUNNY START TO THE DAY...WITH
MID CLOUDS PUSHING EAST INTO THE WRN CWA AS THE DAY GOES ON. H850
TEMPS ARE SLIGHTLY COOLER TODAY BEHIND THE COLD FRONT WHICH WILL
LEAD TO HIGHS IN THE 80S...WITH A FEW 90S OVER THE SCNTRL. SLIGHTLY
COOLER VALUES ARE EXPECT NEAR LK SUPERIOR DUE TO LIGHT NRLY FLOW
AROUND THE HIGH WHICH WILL LEAD TO LK BREEZE DEVELOPMENT. TD
VALUES WILL BE MUCH LOWER THAN YEST...IN THE 50S...AND
WHEN COMBINED WITH THE LOWER TEMPS WILL MAKE IT FEEL MUCH MORE
COMFORTABLE OUTSIDE.
ATTENTION THEN TURNS TO THE UPSTREAM CONVECTION AS IT WILL BE THE
MAIN WEATHER MAKER FOR THE SHORT TERM. SHORTWAVE IN NRN WYOMING AND
ERN MONTANA WILL BE ROTATING AROUND THE UPPER RIDGE THAT HAS BEEN
CAUSING THE WARM/HUMID WEATHER...ALONG WITH BOUTS OF THUNDERSTORMS.
THIS WILL ONCE AGAIN BE THE CASE WITH THIS SHORTWAVE...WHICH
PRODUCED CONVECTION OVER NWRN SD/ND OVERNIGHT AND WILL BRING ANOTHER
PERIOD OF MODERATE RAIN. EVEN THOUGH THE BEST INSTABILITY GRADIENT
STRETCHES FROM ND SE THROUGH CNTRL WI...THINK THE UPPER RIDGE WILL
STEER THE CURRENT CONVECTION MORE TO THE NE THROUGH THE MORNING
HOURS.
BEST AREA OF THE WEAK SHORTWAVE ENERGY WILL SLIDE ACROSS THE NRN
HALF OF THE CWA LATE THIS AFTN AND TONIGHT...ALONG WITH THE H500
HEIGHT FALLS. THIS WILL COINCIDE WITH THE RIGHT ENTRANCE OF THE
UPPER JET ROTATING AROUND THE UPPER LOW OVER HUDSON BAY. FARTHER TO
THE S...STRONG FGEN FROM H800 TO H650...WILL BE OVER WRN LK SUPERIOR
LATE THIS AFTN AND EVENING AND THEN SHIFT SSE TONIGHT. AS EXPECTED
TIGHT H850 THERMAL GRADIENT AND WAA/ISENTROPIC ASCENT OVER SRN UPPER
MI. THUS...EXPECT BEST PCPN CHANCES FROM WRN LK SUPERIOR THROUGH WRN
UPPER MI AND THEN SLIDING SE ACROSS ERN UPPER MI OVERNIGHT WITH A
STRONGER NRLY H850 PUSH AND VEERING WINDS TO THE EAST S OF THE H850
FRONT. OVER THE NRN PART OF LK SUPERIOR...LLVL DRY AIR AND DOWNWARD
AGEOSTROPHIC CIRCULATION MAY END UP LIMITING THE NRN EXTENT OF
THE PCPN.
FAIRLY GOOD CONSENSUS IN THE 00Z MODELS ON THE QPF AMNTS...AS
THEY RANGE FROM SWATHS OF 1-1.7IN ON THE NAM/GEM-REG TO 0.5-0.75IN
ON ECMWF/GFS. ECMWF IS SLIGHTLY FARTHER S THAN THE OTHER TWO...WITH
THE GFS SLIGHTLY FARTHER TO THE NW. LOOKING AT THE 21Z SREF
RUN...IT HAS A 30 PERCENT PROB OVER WRN U.P. OF 1.0IN OF RAIN
TONIGHT AND 50-70 PERCENT OF 0.5 OVER THE W HALF. PWATS ARE AROUND
150-200 PERCENT OF NORMAL...WHICH WOULD SUPPORT THE POSSIBILITY OF
CORRIDORS OF HEAVY RAIN. HAVE BUMPED UP QPF AMNTS SOME AND HAVE
TOTAL AMNTS WITH THIS SYSTEM OF 0.75-1.0IN OVER THE INTERIOR WEST.
WITH THESE AMNTS...WILL NEED TO WATCH IRON COUNTY AND PAINT RIVER
WITH THE ABUNDANCE OF RAIN THEY HAVE SEEN IN THE LAST WEEK /RADAR
ESTIMATED OVER 8IN/. FARTHER TO THE EAST...THINK THE VEERING H850
WINDS WILL REALLY DIMINISH AMNTS AND HAVE LESS THAN 0.5IN E OF
MUNISING/MANISTIQUE.
FINALLY...THE CONVECTIVE POTENTIAL. H850 LIFTED ELEVATED CAPE
GRADIENT IS RIGHT ALONG WI BORDER. IT IS A VERY SKINNY CAPE...WITH
NCAPE VALUES AROUND .08...AND EFFECTIVE SHEAR VALUES AROUND 30KTS
WOULD INDICATE LIMITED POTENTIAL FOR HAIL. 3HR SPC CALIBRATED
THUNDER PROBS INDICATE THE BEST CHANCES ALONG THE WI BORDER
TONIGHT...WHICH MATCHES UP WELL WITH INSTABILITY GRADIENT AND
POTENTIAL CONVECTION DEVELOPING IN CNTRL MN AND NW WI.
THEREFORE...WILL LIMIT CHANCE THUNDER TO THE WI BORDER AND JUST HAVE
SLIGHT CHANCE OVER ALL BUT THE FAR N.
AT THE PRESENT TIME...FEEL FAIRLY CONFIDENT IN THE GOING FORECAST.
ONLY HAVE TWO CONCERNS. ONE...IF THE CONVECTION CURRENTLY GOING IN
NCNTRL SD CAN STAY ON THE INSTABILITY GRADIENT AND HOLD OFF THE
STEERING FROM THE RIDGE...WHICH DOESN/T SEEM TOO LIKELY.
TWO...WOULD BE IF CONVECTION THAT MAY FIRE ALONG THE WARM FRONT AND
INSTABILITY GRADIENT IN CNTRL MN AND NW WI THIS AFTN...WHICH COULD
DISRUPT SOME OF THE LLVL FLOW AND MOISTURE ADVECTION INTO THIS
AREA. BUT WITH THE WAY THE CONVECTION AND SHOWERS HAVE BEEN GOING
IN THE DAKOTAS...FEEL THAT MUCH OF THE AREA WOULD STILL SEE RAIN
IF THAT OCCURS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 522 AM EDT FRI JUL 6 2012
SATURDAY...HIGH PRESSURE AND STRONG DRYING BEHIND THE FRONT SAGGING
TO THE SOUTH WILL BRING CLEARING SKIES AFTER ANY ANY LEFTOVER LIGHT
SHOWERS OVER THE SOUTH EARLY. MAX READINGS SHOULD ALSO BE LOWER WITH
INLAND READINGS IN THE UPPER 70S AND LOWER 80S AS 850 MB TEMPS DROP
INTO THE 12C TO 14C RANGE. LIGHT NRLY GRADIENT FLOW WILL KEEP TEMPS
MAINLY IN THE LOWER 70S NEAR LAKE SUPERIOR. WITH DEWPOINTS DROPPING
INTO THE 50S...FAVORABLE RADIAIONAL COOLING CONDITIOINS SHOULD ALLOW
TEMPS TO DROP INTO THE LOWER TO MID 50S INLAND.
SUNDAY...THE COMBINATION OF A WEAK SHORTWAVE DROPPING INTO THE AREA
IN THE NW FLOW PATTERN AND SBCAPE VALUES INTO THE 400-600 J/KG RANGE
DURING PEAK HEATING MAY BE ENOUGH TO TRIGGER SOME ISOLD INLAND
SHRA/TSRA OVER THE INTERIOR WEST. HOWEVER...ANY RAINFALL AMOUNTS
WOULD BE LIGHT. EVEN THOUGH SEVERAL MODELS SUGGEST THAT ANOTHER WEAK
SHORTWAVE SUNDAY NIGHT MAY ALSO PRODUCE SOME LIGHT SHOWERS...GIVEN
THE GENERALLY DRY AIRMASS...PREFERRED THE ECMWF WHICH DOES NOT SHOW
ANY QPF.
MONDAY THROUGH THURSDAY...A MORE AMPLIFIED PATTERN WITH A MID/UPPER
LEVEL RIDGE OVER WRN NOAM WILL RESULT IN CONTINUED NW FLOW THROUGH
THE WRN GREAT LAKES. THE POTENTIAL ALSO REMAINS FOR WEAK SHORTWAVES
TO MOVE THROUGH THE AREA WITH LOWER END PCPN CHANCES.
HOWEVER...CONFIDENCE IN THE TIMING/STRENGTH OF THESE FEATURES IS
LOW. TENDED TO FAVOR THE DRIER ECMWF QPF...GIVEN THE GFS MOISTURE
BIAS. TEMPERATURES WILL REMAIN CLOSER TO SEASONAL AVERAGES WITH
HIGHS IN THE LOW TO MID 70S MON CLIMBING TO THE UPPER 70S AND LOWER
80S BY WED-THU.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 733 AM EDT FRI JUL 6 2012
VFR CONDITIONS WILL START THE FIRST HALF OF THE TAF PERIOD...AS
HIGH PRESSURE KEEPS LOW LEVEL DRY AIR IN THE AREA. THIS WILL BE
SHORT LIVED...AS SHOWERS AND THUNDERSTORMS ARE ALREADY OCCURRING IN
MN AND THE DAKOTAS. THESE SHOWERS AND POTENTIALLY THUNDERSTORMS
WILL SHIFT EAST LATER THIS AFTN AND TONIGHT AND BRING MOD/HEAVY
RAIN TO MOST SITES. KCMX MAY BE ON THE NORTHERN EDGE...BUT
KIWD/KSAW WILL LIKELY SEE VSBYS/CIGS DROP TO MVFR/IFR. COULD SEE
THUNDER AT KIWD AND POTENTIALLY KSAW AS THE BEST INSTABILITY
GRADIENT RUNS ALONG AND JUST NORTH OF THE WI BORDER. BEHIND THE
PRECIPITATION...COULD SEE SOME LOW CLOUDS AND FOG AT KIWD/KSAW WITH
THE LIGHT UPSLOPE FLOW AND PLENTY OF LLVL MOISTURE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 522 AM EDT FRI JUL 6 2012
HIGH PRESSURE OVER LAKE SUPERIOR THIS MORNING WILL KEEP WINDS BELOW
20 KTS TODAY. A LOW PRESSURE TROUGH WILL CROSS JUST S OF UPPER MI
TONIGHT...WHICH WILL SHIFT WINDS MORE TO THE N. BEHIND THIS
TROUGH...HIGH PRESSURE WILL SETTLE BACK OVER THE UPPER GREAT LAKES
THROUGH THE MIDDLE OF NEXT WEEK AND WILL KEEP WINDS LIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...JLB
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1045 AM CDT FRI JUL 6 2012
.DISCUSSION...
UPDATED FORECAST TO REMOVE CHANCE OF POPS FROM THE FORECAST TODAY
ACROSS MUCH OF THE AREA. MAIN FRONT STRETCHED ACROSS THE WESTERN
EDGE OF THE FORECAST AREA. CONVECTIVE OUTFLOW SURGING SOUTH FROM
CONVECTION TO THE NORTH ACROSS SOUTHWEST MINNESOTA...AND WILL BE
INTERESTING TO SEE IF THIS BOUNDARY CAN BECOME THE FOCUS FOR
THUNDERSTORMS LATER THIS AFTERNOON. HRRR FOCUSES CONVECTION MAINLY
ALONG THE MAIN COLD FRONT...BUT STILL INDICATES SOME CAPPING
ISSUES. THINK THE NAM IS WEAKENING THE CAP TOO QUICKLY AND
CONVECTION WILL BE SCATTERED AT BEST ALONG THE FRONT THROUGH 00Z.
HAVE NOT ALTERED TEMPERATURES AT THIS POINT...BUT IF ANYTHING MAY
NEED TO RAISE HIGHS SLIGHTLY.
&&
.AVIATION.../FOR THE 18Z TAF ISSUANCE/
GENERALLY VFR CONDITIONS EXPECTED THROUGH 07/18Z SATURDAY. THERE IS
A CHANCE OF CONVECTION ALONG A COLD FRONT MOVING THROUGH THE
AREA...THOUGH CONVECTION SHOULD REMAIN FAIRLY ISOLATED AND BE
CONFINED TO SOUTHWEST MINNESOTA THROUGH 07/00Z.
THEREAFTER...CONVECTION MAY TRY TO BUILD SOUTH AND WEST BUT WILL BE
FIGHTING A WARM LAYER ALOFT. WINDS WILL SWITCH TO THE NORTH BEHIND
THE FRONT.
&&
.PREV DISCUSSION.../ISSUED AT 330 AM CDT/
FEEL SAFE THAT ANY THUNDERSTORM DEVELOPMENT THIS MORNING WILL BE
CONFINED TO THE EDGES...FAR WEST...FAR NORTH...AND POSSIBLY IN
SOUTHWEST MN DOWN TO JACKSON COUNTY...WHICH HAS BEEN OFT HIT LATELY
AND WHERE THE WIND FIELDS ALOFT ARE MORE FAVORABLE. THESE ARE THE
AREAS WHERE INSTABILITY WOULD SUPPORT SPOTTY DEVELOPMENT AHEAD OF
THE APPROACHING FRONTAL BOUNDARY. STRONG HEATING SHOULD BEGIN TO
PRODUCE STORMS ON BOTH SIDES OF THE COLD FRONT LATE THIS AFTERNOON.
THESE STORMS SHOULD PROGRESS EAST DURING TONIGHT BUT ARE LIKELY TO
REMAIN SCATTERED. SPC OUTLOOK SEEMS REASONABLE WITH THE BEST CHANCE
OF STORM AND SEVERE STORMS IN SOUTHWEST MN BACK MAYBE TO BROOKINGS
SD. VERY LOCAL GUSTY WINDS AND MARGINALLY SEVERE HAIL WOULD BE
POSSIBLE LATE AFTERNOON AND EVENING.
TEMPERATURES SHOULD WARM WELL...BETTER THAN YESTERDAY...WITH WARMING
AHEAD OF SYSTEM. FRONTAL POOLING OF LOW LEVEL MOISTURE AND
DEWPOINTS CONFIRMS A DECISION TO KEEP THE HEAT ADVISORY AND WARNING
TO ITS SCHEDULED END AT THE END OF TODAY. COOLING IS LIKELY TO KNOCK
THE ADVISORY OUT BEFORE THAT FAR WEST BUT WILL KEEP AS IS FOR
SIMPLICITY. IN ANY EVENT...NAM EARLY LOWERING OF DEWPOINTS DOES NOT
LOOK RIGHT.
AS FRONT DRIFTS SOUTH OF AREA AND COOLING SETS IN TONIGHT...
INSTABILITY ALOFT AND UPPER FLOW GOING WESTERLY AS RIDGE FLATTENS
MAY KEEP THE POTENTIAL FOR A FEW STORMS SOUTHEAST SATURDAY MORNING
AND AM MENTIONING SLIGHT CHANCE. OTHERWISE THE WEEKEND...AND IN FACT
THE REST OF THE FORECAST THROUGH THE NEW WEEK...LOOKS DRY AND MILD
WITH GENERALLY 80S FOR HIGHS AND NOT TOO HUMID IN STABLE
NORTHWESTERLY UPPER FLOW.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...EXCESSIVE HEAT WARNING UNTIL 7 PM CDT THIS EVENING FOR
IAZ001>003-012>014-020>022-031-032.
MN...EXCESSIVE HEAT WARNING UNTIL 7 PM CDT THIS EVENING FOR MNZ081-
089-090.
HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR MNZ071-072-080-
097-098.
NE...EXCESSIVE HEAT WARNING UNTIL 7 PM CDT THIS EVENING FOR NEZ013-
014.
SD...EXCESSIVE HEAT WARNING UNTIL 7 PM CDT THIS EVENING FOR
SDZ066>071.
HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR SDZ038>040-050-
052>065.
&&
$$
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1143 AM MDT FRI JUL 6 2012
.UPDATE...
FRONT HAS DROPPED IN FARTHER SOUTH THAN EARLIER NAM12 MODEL HAD
SUGGESTED. RUC13 AND HRRR HAVE LATCHED ONTO THIS AND SUGGEST A
SLIGHTLY BETTER POTENTIAL FOR -TSRA ACROSS EL PASO AND PUEBLO
COUNTIES. THESE MODELS ARE ALSO SUGGESTING A SLIGHTLY BETTER
CHANCE FOR RAINFALL ON THE WALDO CANYON BURN SCAR...HOWEVER STORM
MOTIONS SHOULD MINIMIZE FLASH FLOODING THREAT UNLESS STORMS TRAIN
OVER THE SAME REGION. THIS WILL BE MONITORED CLOSELY THROUGH THE
AFTERNOON. DEW POINTS APPEAR TO BE HANGING IN A LITTLE BETTER
ALONG AND NORTH OF THE FRONTAL BOUNDARY WHICH EXTENDS FROM 10
MILES WEST OF KLHX...TO NEAR WALSENBURG...SO THERE WILL BE A
BETTER CHANCE FOR WETTING RAINFALLS TO OCCUR TO THE NORTHWEST OF
THIS AXIS. -KT
&&
.AVIATION...
THUNDERSTORMS WILL CONTINUE TO DEVELOP ACROSS THE MOUNTAIN AREAS
AND MAY AFFECT THE TAF SITES AFTER 20-21Z. FRONTAL BOUNDARY HAS
DROPPED IN FARTHER SOUTH ACROSS THE PLAINS THAN ORIGINALLY
ANTICIPATED AND THIS MAY LEAD TO A BETTER CHANCE FOR -TSRA TO
AFFECT KCOS AND KPUB. 18Z TAFS WILL HAVE A VCTS FOR BOTH SITES FOR
NOW...AS STORMS SHOULD REMAIN FAIRLY ISOLATED. GUSTY ERRATIC WINDS
UP TO 35 KTS...AND VFR CIGS/VIS WITH LIGHT TO MODERATE RAIN WOULD
BE THE MAIN IMPACTS IF STORMS HIT TERMINALS. KALS IS UNDER BETTER
MONSOON MOISTURE TAP SO HAVE INCLUDED A TEMPO GROUP FOR -TSRA
AFTER 20-21Z. VFR CIGS...BRIEF MODERATE TO HEAVY RAINFALL...AND
GUSTS UP TO 30 KTS WILL BE THE MAIN THREAT. -KT
&&
.PREV DISCUSSION... /ISSUED 506 AM MDT FRI JUL 6 2012/
SHORT TERM...
(TODAY AND TONIGHT)
..MONSOON SHOWERS MAINLY MOUNTAINS TODAY...
IT APPEARS THAT MOST STORMS TODAY WILL BE HELD TO THE MOUNTAIN
AREAS...WITH JUST ISOLATED ACTIVITY FOUND OVER THE ADJACENT PLAINS.
THE LATEST NAM12 AND 4KM WRF DEVELOP FAIRLY WIDESPREAD THUNDERSHOWERS
OVER THE MOUNTAINS BY LATE MORNING AND THEN PUSH THEM OFF TO THE
NORTH OR NORTHWEST THROUGH THE AFTERNOON INTO THE EVENING WITH SOUTH
TO SOUTHEAST STEERING WINDS. A SURFACE BOUNDARY REMAINS NORTH OF THE
PALMER DIVIDE THROUGH ABOUT 3 PM...AND THEN SHIFTS SOUTH THROUGH THE
EVENING...GRADUALLY WEAKENING AND BECOMING MORE DIFFUSE THROUGH THE
NIGHT. THE BOUNDARY MAY HELP TO CREATE SOME THUNDERSHOWERS NORTH OF
THE ARKANSAS RIVER EARLY IN THE EVENING...BUT AFTER THAT IT LOOKS
LIKE CONVECTION WILL GENERALLY DISSIPATE ACROSS THE AREA FOR THE
NIGHT.
ACROSS THE PLAINS...IT ACTUALLY LOOKS DRY FOR THE MOST PART TODAY.
THE COMBINATION OF SOME DRIER AIR PUSHING UP FROM THE SOUTHEAST AND
SOUTH TO SOUTHEAST STEERING WINDS SHOULD TEND TO KEEP MOST
CONVECTION CONFINED TO THE MOUNTAINS.
AS FOR THE WALDO CANYON SCAR...THE POTENTIAL STILL EXISTS FOR SOME
STORMS TO DEVELOP IN THAT AREA THIS AFTERNOON AND EVENING.
HOWEVER...IT CURRENTLY LOOKS LIKE ANY STORMS THAT DO DEVELOP OVER
THE SCAR WILL PROBABLY MOVE OFF TO THE NORTH OR NORTHWEST PRETTY
QUICKLY...LOWERING THE FLASH FLOOD POTENTIAL ACROSS THE SCAR FOR
TODAY. AS ALWAYS...HOWEVER...REMEMBER THAT WEATHER FORECASTING IS A
FLUID SCIENCE...SUBJECT TO CHANGE WITH THE NEXT MODEL RUN. SO
PLEASE STAY TUNED TO THE NATIONAL WEATHER SERVICE FOR THE LATEST
FORECASTS...WATCHES AND WARNINGS THROUGH THE DAY. LW
LONG TERM...
(SATURDAY THROUGH FRIDAY)
..POTENTIAL FOR HEAVY RAIN INTO EARLY NEXT WEEK...
MODELS CONTINUE TO INDICATE THE POTENTIAL FOR HEAVY RAINFALL INTO
EARLY NEXT WEEK WITH WEAK FLOW ALOFT PROGGED ACROSS THE REGION AS
THE CENTER OF A LARGE UPPER HIGH PRESSURE SYSTEM ACROSS THE CENTRAL
HIGH PLAINS SLOWLY RETROGRADES ACROSS THE ROCKIES AND INTO THE GREAT
BASIN BY MONDAY. HOWEVER THE DEVIL REMAINS IN THE MESOSCALE DETAILS
AS TO WHERE THE HEAVIEST RAINFALL WILL OCCUR. WITH THAT SAID...THE
LATEST MODELS ARE INDICATING THE MONSOONAL MOISTURE PLUME ACROSS
WESTERN AND CENTRAL COLORADO SPREADING ACROSS THE EASTERN MOUNTAINS
THROUGH THE DAY ON SATURDAY. THIS...ALONG WITH WEAK SOUTHERLY FLOW
ALOFT...LOOKS TO KEEP SCATTERED TO NUMEROUS SLOWLY MOVING SHOWERS
AND THUNDERSTORMS ACROSS THE HIGHER TERRAIN SATURDAY AFTERNOON.
FURTHER EAST...WEAK LOW LEVEL UPSLOPE FLOW HELPS TO KEEP LOW LEVEL
MOISTURE IN PLACE ACROSS THE EASTERN PLAINS WITH LATEST NAM
INDICATING DEW PTS IN MID TO UPPER 50S AND CAPES OF 1000-1500 J/KG
ACROSS SOUTHEAST COLORADO SATURDAY AFTERNOON. GFS REMAINS A TAD
FURTHER NORTH AND EAST WITH THE RIBBON OF CAPE ACROSS NORTHEAST
COLORADO AND NORTHWEST KANSAS. AT ANY RATE...CONVECTION ACROSS THE
PLAINS SATURDAY AFTERNOON LOOKS TIED TO SOLAR HEATING AND
INTERACTION WITH ANY CONVECTIVE OUTFLOWS.
BY LATE SATURDAY AFTERNOON THROUGH SUNDAY NIGHT...FLOW ALOFT BECOMES
MORE WEST TO NORTHWEST WHICH PUSHES BULK OF MONSOONAL MOISTURE PLUME
ACROSS CENTRAL AND EASTERN COLORADO. MODELS ARE ALSO INDICATING
SURFACE HIGH PRESSURE BUILDING ACROSS THE NORTHERN AND CENTRAL HIGH
PLAINS WHICH KEEPS MOIST LOW LEVEL UPSLOPE IN PLACE WITH MODEL
SOUNDINGS INDICATING SATURATED PROFILES TO BETWEEN H6 AND H5. MINOR
DISTURBANCES LIKELY EMBEDDED WITHIN THE PLUME...COULD KEEP
CONVECTION ONGOING SATURDAY EVENING INTO SUNDAY MORNING WITH WIDE
SPREAD CONVECTION EXPECTED AGAIN SUNDAY AFTERNOON AND EVENING. THE
LATEST NAM IS INDICATING THE POSSIBILITY FOR HEAVY RAINFALL ACROSS
THE PIKES PEAK REGION AND THE WALDO CANYON BURN SCAR SATURDAY NIGHT
WITH SFC-H7 EASTERLY FLOW SUPPORTING STORM TRAINING. BY
MONDAY...UPPER FLOW BECOMES MORE NORTHERLY WITH BULK OF MOISTURE
REMAINING IN PLACE ACROSS SOUTH CENTRAL AND SOUTHEAST
COLORADO...SUPPORTING THE POTENTIAL FOR HEAVY RAINFALL ONCE AGAIN.
WITH THE WIDESPREAD RAINFALL AND CLOUD COVER...TEMPERATURES ARE
EXPECTED TO BE AT OR BELOW SEASONAL AVERAGES THROUGH THE PERIOD.
FOR TUESDAY THROUGH THURSDAY...WEAK EAST TO NORTHEAST FLOW ALOFT
PROGGED ACROSS THE REGION AS THE UPPER HIGH CONTINUES TO BUILD
ACROSS THE DESERT SOUTHWEST AND GREAT BASIN. THIS WILL HELP TO
PUSH MOISTURE PLUME SOUTH AND WEST OF THE AREA...SUPPORTING DRIER
AND WARMER CONDITIONS THROUGH THE END OF THE WEEK...ESPECIALLY
ACROSS THE EASTERN PLAINS. THERE WILL STILL BE ENOUGH MOISTURE FOR
ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ACROSS THE
HIGHER TERRAIN...THOUGH STORMS WILL SLOWLY BECOME MORE HIGH BASED
OWNING TO THE DIMINISHING POTENTIAL FOR LOCALLY HEAVY RAINS THROUGH
THE PERIOD. -MW
AVIATION...
SCATTERED TO NUMEROUS THUNDERSHOWERS ARE EXPECTED TO DEVELOP OVER
THE MOUNTAINS LATE THIS MORNING AND PERSIST THROUGH THE AFTERNOON
INTO THE EVENING. DRY CONDITIONS ARE EXPECTED OVER MOST OF THE
PLAINS TODAY. SCATTERED STORMS AT KCOS THIS AFTERNOON AND
EVENING...WITH A SLIGHT CHANCE FOR STORMS AT KPUB AND KALS.
POSSIBLE MVFR/IFR CONDITIONS ASSOCIATED WITH ANY THUNDERSTORMS.
ADDITIONAL STORM THREATS WILL INCLUDE LIGHTNING...WIND GUSTS TO 40
MPH...AND HEAVY RAINFALL. MOST CONVECTION WILL DIE DOWN BY 03Z. LW
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31/28
AREA FORECAST DISCUSSION
NWS DENVER CO
1116 AM MDT FRI JUL 6 2012
.UPDATE...
&&
.SHORT TERM...CURRENT SATELLITE AND RADAR PICTURES ARE SHOWING THE
CONVECTION DEVELOPING OVER THE MOUNTAINS AND FOOTHILLS. CELLS
WILL BE MOVING NEAR DUE NORTH AGAIN TODAY. COMPARING YESTERDAY`S
17Z DIA OBSERVATION TO THE CURRENT 17Z VERSION...IT IS 82 OVER 52
CURRENTLY WHILE YESTERDAY IS WAS 82 OVER 55. HOWEVER...WE CONTINUE
TO HAVE A FETCH OF WIDESPREAD MID 50S DEW POINT UPSTREAM IN THE
NORTHEASTERLY UPSLOPE FLOW. WILL STAY THE COURSE WITH GOING
FORECAST. COOLER MORE MOIST CONDITIONS ARE NEEDED.
.AVIATION...WINDS AT DIA ARE EAST-NORTHEASTERLY AT THIS TIME. THEY
SHOULD STY MORE NORTHWESTERLY THE REST OF THE AFTERNOON AND THIS
EVENING. RJK
&&
.PREV DISCUSSION... /ISSUED 440 AM MDT FRI JUL 6 2012/
SHORT TERM...THE BROAD UPPER HIGH CONTINUES TO MEANDER AROUND THE
CENTRAL PLAINS STATES WITH A RESULTING MOIST SOUTHERLY FLOW ALOFT
ACROSS COLORADO. WATER VAPOR IMAGERY SHOWING THE PLUME OF MOISTURE
IS WELL ESTABLISHED ACROSS CENTRAL AND WESTERN PORTIONS OF
COLORADO...WHILE DRIER AIR IS STILL HOLDING ACROSS FAR EASTERN
COLORADO. PRECIPITABLE WATER VALUES FROM GPS ARE OVER AN INCH
ACROSS MUCH OF THE AREA THIS MORNING. AT THE SURFACE...DEWPOINTS
ARE IN THE 50S ACROSS MUCH OF THE PLAINS WITH THE SURFACE TROF
ACROSS MUCH OF EASTERN COLORADO. HARD TO TELL WHERE THE FRONTAL
BOUNDARY IS AT THIS TIME WITH VERY LITTLE PRESSURE RISE REFLECTION
ACROSS WYOMING. MODELS STILL SHOWING WEAK UPSLOPE FLOW DEVELOPING
THIS MORNING THOUGH IT WILL BE SHALLOW. HARD TO REALLY MAKE MANY
CHANGES IN THIS UPCOMING FORECAST PACKAGE WITH THE TREND FOR
HIGHER CHANCES OF STORMS AND COOLING TEMPERATURES STILL LOOK ON
TRACK. HOWEVER STILL A LITTLE SUSPECT OF MODEL DEPICTION OF TOO
MUCH LOW LEVEL MOISTURE...ESPECIALLY SINCE THEY HAVE BEEN
CONSISTENTLY TOO WET FROM THE PAST FEW DAYS AS COMPARED TO
REALITY. LATEST LOOK AT THE HRRR ACTUALLY DROPS DEWPOINTS INTO THE
LOWER 40S OVER THE FRONT RANGE WHICH WOULD CUT DOWN ON THE
INSTABILITY. BEST CHANCES FOR STORMS AGAIN MOUNTAINS...FOOTHILLS
AND SEEPING OUT ONTO THE ADJACENT PLAINS. LOWER POPS FURTHER EAST
IN THE DRIER AIR.
LONG TERM...SOUTHERLY FLOW ON THE WESTERN EDGE OF TALL UPPER
RIDGE OVER THE GREAT PLAINS WILL CONTINUE TO ADVECT AMPLE AMOUNTS
OF MOIST SUBTROPICAL AIR UP OVER COLORADO DURING THE UPCOMING WEEKEND.
IN ADDITION..A PERSISTENT EASTERLY LOW-LEVEL FLOW ON THE PLAINS
WILL CONTINUE TO PUSH MOIST BOUNDARY LAYER AIR UPSLOPE. WITH MEAN
LAYER SPECIFIC HUMIDITIES IN THE 6-8 G/KG RANGE AND PRECIPITABLE
WATER VALUES IN THE 1 TO 1.5 INCH RANGE...CHANCES ARE GOOD WE/LL
SEE PERIODS OF MEASURABLE RAINFALL FROM THUNDERSTORMS AT LEAST
MONDAY MORNING. THE BEST CHANCE FOR THIS PRECIP APPEARS TO BE LATE
SATURDAY AFTERNOON AND OVERNIGHT AND SUNDAY AFTERNOON AND EVENING...
..AND PARTICULARLY OVER AND ALONG THE FRONT RANGE WHERE MODEL
QPF FIELDS INDICATE PRETTY IMPRESSIVE RAIN TOTALS BY MONDAY. AS
WAS NOTED ABOVE IN THE SHORT TERM DISCUSSION...MODELS ESPLY THE
GFS HAVE BEEN OVER DOING QPF AMOUNTS AND ATMOSPHERIC MOISTURE FOR
SOME TIME NOW. WITH THAT IN MIND...KEPT PRECIP AMOUNTS IN THE
FCST GRIDS BELOW VALUES OFFERED BY THE MODELS...HOWEVER WILL HANG
ONTO THE 40-50 PCT POPS ON THE PLAINS AND WESTERN VALLEYS AND
LIKELY POPS AT MTN LOCATIONS PRETTY MUCH FOR THE ENTIRE WEEKEND.
FURTHERMORE...MOIST UPSLOPE FLOW...WIDESPREAD CLOUD COVER AND
PERIODS OF PRECIP WILL HAVE A BIG INFLUENCE ON TEMPERATURES THIS
WEEKEND. MODEL TEMPERATURES GUIDANCE GENERALLY INDICATING HIGHS IN
THE 70S AT LOWER ELEVATIONS AND 50-60S IN THE HIGH COUNTRY. CAN/T
ARGUE WITH THAT...ALTHOUGH TEMPERATURES OFFERED BY THE GFS APPEAR
TOO COOL EVEN WITH ALL OF THE CLOUD COVER ANTICIPATED.
BY EARLY NEXT WEEK...THE UPPER RIDGE WOBBLING OVER THE CENTRAL
GREAT PLAINS IS FORECAST TO SHIFT WESTWARD OVER THE CENTRAL ROCKY
MTN REGION LATE IN THE WEEKEND AND BECOME CENTERED OVER THE EASTERN
GREAT BASIN BY MONDAY. THIS CAUSES WINDS ALOFT..ALBEIT IT LIGHT
WINDS...TO REVERSE AND COME FROM A NORTHERLY DIRECTION OVER THE
FORECAST AREA...CONSEQUENTLY CAUSING THE MONSOON MOISTURE PLUME
TO DIVERT WESTWARD OVER THE DESERT SOUTHWEST AND GREAT BASIN
REGIONS. HOWEVER DO NOT EXPECT TO SEE A COMPLETE SHUT OFF OF THIS
SUBTROPICAL MOISTURE UNTIL TUESDSAY OR WEDNESDAY. THEREFORE STRONG
DAYTIME HEATING SHOULD CONTINUE TO BUBBLE UP THE LAST OF THIS
MONSOONAL MOISTURE INTO SCATTERED AFTERNOON AND EVENING
THUNDERSTORMS...MAINLY OVER AND NEAR THE MTNS EARLY NEXT WEEK.
SHOULD ALSO SEE A GRADUAL RAISE IN TEMPERATURES NEXT WEEK...WITH
90 DEG READINGS RETURNING TO THE PLAINS BY WEDNESDAY OR THURSDAY
WITH THE UPPER RIDGE BUILDING BACK OVER COLORADO.
AVIATION...LITTLE CHANGE ANTICIPATED FOR 12Z ISSUANCES WITH BEST
CHANCE FOR STORMS FROM MID AFTERNOON THROUGH THE EVENING HOURS AND
THEN SOME LINGERING SHOWER ACTIVITY THROUGH THE NIGHT. AMOUNT OF
TEMPO CONDITIONS MAY BE OVERDONE IN TERMS OF OVERALL THUNDERSTORM
COVERAGE BUT HARD TO REALLY CUT THINGS DOWN TOO MUCH UNTIL THE
REALITY OF HOW MUCH MOISTURE IS REALLY OUT THERE. SURFACE WINDS
WILL GRADUALLY TREND TO THE NORTHEAST BUT NOT A REAL STRONG
FRONTAL BOUNDARY EXPECTED THIS MORNING.
HYDROLOGY...GIVEN SOME OF THE SUSPECT MOISTURE VALUES IN THE MODELS AM
RELUCTANT ON ANY FLASH FLOOD WATCHES AT THIS TIME. STORMS WILL STILL
BE MOVING AT 10-15KT BUT STORM TRAINING STILL A POSSIBILITY. BURN
SCARS WILL CERTAINLY NEED TO BE WATCHED BUT OVERALL FLOODING
THREAT WILL BE MORE LOCALIZED AND LIMITED TO THE BURN AREAS.
CERTAINLY HEAVY RAIN CAN BE EXPECTED WITH THE STORMS AND RAINFALL
RATES WILL BE OVER AN INCH IN 30 MINUTES WITH THE STRONGER STORMS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ENTREKIN
LONG TERM....BAKER
AVIATION...ENTREKIN
AREA FORECAST DISCUSSION
NWS MIAMI FL
230 PM EDT FRI JUL 6 2012
.SHORT TERM...(TONIGHT-SUNDAY NIGHT)
THE LATEST HRRR/WRF/NAM MODEL REFLECTIVITIES GENERALLY REMAIN IN
GOOD AGREEMENT THROUGH THE EVENING HOURS TODAY AND INDICATE MAINLY
ISOLATED COVERAGE DEVELOPING INLAND AND TOWARD THE GULF COAST AS
THE GULF/EAST COAST SEA BREEZES BEGIN TO MERGE. THE HRRR IS THE
MORE BULLISH SOLUTION AND GENERATES SLIGHTLY MORE COVERAGE OVER
THESE AREAS. PROVIDED A SUFFICIENT AMOUNT OF BOUNDARY LAYER
MOISTURE...MINUS 8 DEG C AT 500 MB AND DAYTIME HEATING ALONG WITH
THE SEA BREEZES MERGING COULD BE ENOUGH TO SUPPORT A STRONG STORM
OR TWO LATER TODAY THROUGH THE EARLY EVENING PERIOD...MAINLY OVER
THE WESTERN ZONES TOWARD THE GULF COAST. MEANWHILE...THE EASTERN
HALF OF THE S FL PENINSULA SHOULD REMAIN DRY UNDER MOSTLY SUNNY
SKIES WITH TEMPERATURES POSSIBLY REACHING THE LOWER 90S OVER THE
METRO AREAS FOR THE AFTERNOON HIGHS.
SATURDAY THROUGH SUNDAY NIGHT...AFTER ANOTHER SIMILAR DAY SATURDAY
WITH MOSTLY SUNNY SKIES AND TEMPERATURES REACHING THE MID 90S INLAND
TO AROUND 90 AT THE COAST...THE LATEST GFS/ECMWF CYCLE REMAINS IN
DECENT AGREEMENT AND CONTINUES TO INDICATE INCREASING DEEP LAYER
MOISTURE SPREADING WNW ACROSS THE AREA LATE SATURDAY NIGHT THROUGH
SUNDAY AS A WEAK TROUGH APPROACHES AND MOVES INTO THE AREA FROM
THE SE. THE NAM REMAINS THE OUTLIER AND DOESN`T INDICATE MUCH OF
AN INCREASE IN MOISTURE AND GENERALLY DAMPENS THE TROUGH AS IT
APPROACHES THE AREA. WILL LEAN MORE TOWARD THE GFS/ECMWF SOLUTIONS
AND SLIGHT ENHANCE THE RAINFALL CHANCES SUNDAY AND SUNDAY NIGHT.
.LONG TERM...(MONDAY-WEDNESDAY)
THE LATEST GUIDANCE SUGGESTS THAT DEEP LAYER MOISTURE ASSOCIATED
WITH THE AFOREMENTIONED TROUGH COULD LINGER ACROSS THE REGION
THROUGH THE EARLY PART OF NEXT WEEK WITH SCATTERED SHOWERS AND
THUNDERSTORMS POSSIBLE EACH DAY.
&&
.MARINE...
LIGHT TO MODERATE EAST SOUTHEAST WINDS WILL PERSIST THROUGH THE
WEEKEND AS A WEAK TROUGH APPROACHES AND MOVES INTO THE AREA FROM
THE SOUTHEAST. SLIGHTLY CHOPPIER CONDITIONS WILL REMAIN POSSIBLE
AROUND THE COASTAL LOCATIONS AND ACROSS THE BAY ASSOCIATED WITH
THE AFTERNOON SEA BREEZES. RAIN CHANCES ARE EXPECTED TO INCREASE
LATE SATURDAY NIGHT OVER THE ATLANTIC WATERS AS THE TROUGH BEGINS
TO INFLUENCE THE LOCAL WEATHER.
&&
.FIRE WEATHER...
NO CONCERNS AS RH VALUES REMAIN ABOVE CRITICAL LEVELS EACH DAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 78 90 78 91 / 10 20 10 30
FORT LAUDERDALE 80 91 79 90 / 10 20 10 40
MIAMI 80 91 80 92 / 10 20 20 50
NAPLES 75 91 76 91 / 20 30 30 50
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...30/KOB
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
459 PM CDT FRI JUL 6 2012
.DISCUSSION...
315 PM CDT
SHORT TERM...TODAY THROUGH SATURDAY NIGHT...
A WEAK STATIONARY FRONT LIES ACROSS THE WISCONSIN/ILLINOIS BORDER
WITH A LAKE BREEZE SLOWLY PUSHING INTO NORTHEAST IL. SCT CU HAS
DEVELOPED ALONG THE LAKE BREEZE...HOWEVER NOT EXPECTING WIDESPREAD
CONVECTION TO DEVELOP. LATEST RUC ANALYSIS INDICATES 3000+ J/KG OF
SFC BASED CAPE ALONG THE LAKESHORE...HOWEVER SUSPECTING THE 100
J/KG OF CIN IS HOLDING CONVECTION BACK. AMDAR SOUNDINGS ALSO
INDICATE THERE IS A SMALL CAP IN THE VICINITY OF THE LAKE BREEZE.
UNLIKE YESTERDAY...THERE IS NO SIGNIFICANT FORCING FEATURE IN THE
REGION OUTSIDE OF THE LAKE BREEZE...AND THE LAKE BREEZE IS NOT
VERY SIGNIFICANT WITH LIGHT WINDS ON BOTH SIDES OF IT. AS
SUCH...AN ISOLATED STORM COULD FIRE...BUT BETTING AGAINST IT AND
GOING WITH A DRY FORECAST.
TEMPERATURES TONIGHT WILL BE IN THE MID TO UPPER 70S...EXCEPT FOR
LOW 80S DOWNTOWN. HEAT INDICES WILL BE IN THE MID 70S
TONIGHT...EXCEPT FOR MID 80S TO NEAR 90 DOWNTOWN.
A COLD FRONT SINKS SOUTH DOWN THE LAKE TONIGHT...BUT DOES NOT REACH
THE SOUTHERN END OF LAKE MICHIGAN UNTIL SATURDAY AFTERNOON. AS
SUCH...EXPECTING OPPRESSIVE HEAT TO CONTINUE TOMORROW WITH MANY
AREAS ONCE AGAIN SEEING TEMPS AROUND 100 DEGREES. ONLY COOLER SPOTS
WOULD BE NEAR UGN AND ALONG THE LAKEFRONT LATE TOMORROW. WINDS WILL
TURN ON SHORE BEHIND THE FRONT PROVIDING RELIEF TO THE NEARSHORE
REGIONS FIRST. HOWEVER...EXPECTING LAKE FRONT AREAS TO REACH THEIR
DAYTIME MAX IN THE MID TO UPPER 90S BEFORE THE COLD FRONT ARRIVES.
MAX HEAT INDICES WILL BE IN THE UPPER 90S TO 105 DEGREES TOMORROW
EAST OF I-355...WITH 105 TO 119 EXPECTED IN THE OUTLYING AREAS. AS
THE FRONT SINKS SOUTH THROUGH THE CWA...TEMPS WILL DROP
SUDDENLY...BUT EXPECTING DEWPOINTS TO REMAIN IN THE 60S THROUGH
SATURDAY NIGHT. NONETHELESS...LOW TEMPS SATURDAY NIGHT WILL BE IN
THE MID 60S TO AROUND 70...PROVIDING THE FIRST REFRESHING NIGHT IN A
LONG TIME FOR MANY AREAS.
NOT EXPECTING MUCH PRECIP ALONG THE FRONT AS MOISTURE DISSIPATES AS
THE FRONT APPROACHES AND FORCING ALONG THE FRONT IS LESS THAN
IMPRESSIVE. WAS NOT COMFORTABLE GOING WITH A DRY FORECAST...BUT NOT
EXPECTING THE WIDESPREAD RAIN THAT WE NEED. SCATTERED THUNDERSTORMS
ARE POSSIBLE SATURDAY AFTERNOON AND NIGHT. WIND SHEAR IS NOT
FAVORABLE FOR SEVERE WEATHER...AND MODEL SOUNDINGS SUGGEST NO CAPE
TO WORK WITH. HOWEVER WITH INVERTED V SOUNDINGS...STRONG WINDS ARE
POSSIBLE.
JEE
LONG TERM...SUNDAY THROUGH FRIDAY...
THE BIG STORY IS THE END OF THE WITHERING HEAT AND HUMIDITY...AT
LEAST THROUGH THIS EXTENDED PERIOD FORECAST...THOUGH THE 6 TO 10/8
TO 14 DAY OUTLOOKS FROM CPC SUGGEST VERY WARM CONDITIONS MAY BE IN
STORE AGAIN BEYOND DAY 7. UNFORTUNATELY...NO RELIEF IS IN SIGHT FOR
THE WORSENING DROUGHT CONDITIONS ACROSS THE REGION...THOUGH AFTER
THE SEEMINGLY ENDLESS HEAT WAVE...CONDITIONS WILL BE QUITE PLEASANT
FOR OUTDOOR ACTIVITIES.
BLOCKING IN THE NORTH ATLANTIC WILL KEEP THE PATTERN VERY SLOW
MOVING...BUT A LONG WAVE TROUGH CURRENTLY NEAR HUDSON BAY WILL BE
ABLE TO KNOCK DOWN THE EVER PRESENT INTENSE MIDLEVEL RIDGE THAT HAS
BEEN PARKED OVER THE CENTRAL CONUS. THIS WILL SHIFT THE UPPER LEVEL
PATTERN TO ONE CHARACTERIZED BY RIDGING OVER THE INTERIOR WEST AND
LONG WAVE TROUGHING STRETCHING DOWN FROM EASTERN CANADA TO THE
MIDWEST AND NORTHEAST.
THE FRONT WILL HAVE PROGRESSED THROUGH THE CWA ON SUNDAY...WITH GOOD
COOL ADVECTION IN ITS WAKE MERCIFULLY KEEPING TEMPERATURES IN THE
80S...EXCEPT SLIGHTLY COOLER ON THE LAKEFRONT WITH PERSISTENT
NORTH/NORTHEAST FLOW. AIR MASS BEHIND THE FRONT WILL ALSO BE MUCH
DRIER AND COMFORTABLE...AS DEWPOINTS DROP INTO THE 50S AND POSSIBLY
EVEN 40S IN THE NORTHERN CWA LATER IN THE DAY. SOME GUIDANCE TRYING
TO HINT AT POST FRONTAL ISOLATED SHRA/TSRA SUNDAY...BUT WILL SHIFT
INHERITED SLIGHT POPS TO SOUTHERN CWA WHERE FORECAST SOUNDINGS SHOW
DECENT ELEVATED INSTABILITY THROUGH SUNDAY AFTERNOON.
AFTER SUNDAY...NO REAL CONCERNS TO SPEAK OF...OTHER THAN CONTINUED
LACK OF RAINFALL...WHICH IS A CONCERN IN THIS WORSENING DROUGHT.
SURFACE HIGH PRESSURE WILL BUILD SOUTH OVER WESTERN GREAT LAKES
REGION AND BLOCKY WEATHER PATTERN WILL KEEP THE HIGH LOCKED OVERHEAD
FOR MUCH OF THE WEEK...FAVORING SYNOPTIC NORTH/NORTHEAST FLOW
SHIFTING TO GENERALLY LIGHT WINDS AND AFTERNOON LAKE BREEZES.
TEMPERATURES WILL START OUT NEAR SEASONABLE...WARMEST ON MONDAY AND
THEN LIKELY WARMING BACK TO A BIT ABOVE NORMAL LATER IN THE WEEK AS
MIDLEVEL HEIGHTS RISE AND TEMPERATURES WARM ALOFT. LIKELY DAILY LAKE
BREEZES WILL KEEP THE LAKEFRONT COOLER...BUT NOT MUCH COOLER AS THE
CONTINUOUS HEAT THIS SUMMER HAS LEFT LAKE MICHIGAN WATER
TEMPERATURES WELL ABOVE NORMAL FOR THIS POINT IN JULY. DESPITE GFS
WANTING TO OCCASIONALLY PAINT QPF WITH HIGH PRESSURE IN THE MIDDLE
OF A DROUGHT...WILL SIDE WITH THE MORE SUPERIOR AND STABLE ECMWF IN
MAINTAINING A DRY FORECAST THROUGH LATE NEXT WEEK.
RC
&&
.CLIMATE...
459 PM CDT
HERE ARE THE RECORDS FOR SATURDAY JULY 7TH...
CHICAGO MAX T...102 IN 1980....HIGH MIN T 78/1876.
ROCKFORD MAX T...105 IN 1936...HIGH MIN T...75/1928.
THE ALL TIME RECORD HIGH FOR CHICAGO IS 105 SET BACK ON JULY 24 1934
AND IN ROCKFORD IS 112 SET ON JULY 14 1936.
FOR CHICAGO THE MOST CONSECUTIVE 100 DEGREE OR HIGHER DAYS IS
THREE...JULY 3RD THROUGH 5TH OF 1911...AUGUST 4TH THROUGH 6TH OF
1947...AND JULY 4TH THROUGH 6TH OF 2012.
FOR ROCKFORD THE MOST CONSECUTIVE 100 DEGREE OR HIGHER DAYS IS
NINE...JULY 6TH THROUGH 14TH OF 1936.
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* LAKE BREEZE HANGING UP OVER THE ORD AND MDW AIRFIELDS THE NEXT
HOUR TO TWO.
* VERY SMALL BUT NON-ZERO CHANCE FOR A ROGUE SHRA/TSRA THIS
LATE AFTERNOON.
* WINDS SHIFTING FROM SOUTHWEST TO NORTHEAST MIDDAY SATURDAY WITH
COOL FRONTAL PASSAGE.
* SLIGHT CHANCE SHRA/TSRA SATURDAY.
MDB/MTF
//DISCUSSION...UPDATED 18Z...
LAKE BREEZE BOUNDARY NOW REACHING ORD/MDW SHOULD CROSS OVER THE
TERMINALS IN THE NEXT HOUR OR LESS. SCATTERED CU HAS DEVELOPED
NEAR THE BOUNDARY ACROSS THE AREA BUT LATEST AIRCRAFT SOUNDINGS
SHOW AT LEAST SOME INHIBITION KEEPING THE CU FROM DEVELOPING INTO
SHRA/TSRA. NOT A WHOLE LOT OF FORCING OTHER THAN CONVERGENCE ALONG
THE LAKE BREEZE SO THIS CAP MAY HOLD. DESPITE THIS...CANNOT RULE
OUT AN ISOLATED SHRA/TSRA DEVELOPING PRIOR TO 00Z BUT THE CHANCE
IS MINIMAL AND TOO LOW TO INCLUDE IN THE TAF.
MDB
FROM 18Z...
VARIABLE WINDS BETWEEN NORTHWEST AND SOUTHWEST CONTINUE AT THE
TERMINALS WITH LAKE BREEZE BOUNDARY STILL CONTINUING INLAND.
BOUNDARY HAD SLOWED IN THE LAST HALF HOUR BUT HAS NOW STARTED TO
SPEED UP. DID SLOW ARRIVAL TIME AT ORD/MDW AND WILL NEED TO
MONITOR FOR ADJUSTMENTS BUT STILL EXPECT THE BOUNDARY TO CROSS THE
FIELDS. GYY HAS SHIFTED TO THE NORTH WITH THE LATEST OB. THE
BOUNDARY WILL DIMINISH EARLY THIS EVENING AND EXPECT A VARIABLE
BUT MAINLY WEST OR SOUTHWESTERLY WIND TO BE IN PLACE WITH SPEEDS
GENERALLY LIGHT. SOUTHWEST WINDS ARE EXPECTED TO CONTINUE THROUGH
MUCH OF SATURDAY MORNING BUT A COOL FRONT WILL DROP SOUTHWARD
ACROSS THE AREA MIDDAY/EARLY AFTERNOON SHIFTING WINDS TO THE NORTH
AND NORTHEAST. SHOULD SEE SOME GUSTINESS TO AROUND 20 KT DEVELOP
DURING THE LATE AFTERNOON AND EARLY EVENING.
THUNDER CHANCES REMAIN MINIMAL THIS AFTERNOON BUT NOT QUITE ZERO.
FOCUS WOULD BE THE LAKE BREEZE BUT BETTER CHANCE SEEMS TO BE NORTH
OF THE IL/WI STATE LINE. BEYOND THAT...THERE IS A SLIGHT CHANCE
FOR SHRA/TSRA SATURDAY AHEAD AND BEHIND THE FRONT SATURDAY. CHANCE
IS LOW AND COVERAGE LOOKS TO BE ISOLATED TO SCATTERED SO WILL
LEAVE THE TAF DRY FOR NOW.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* HIGH CONFIDENCE THAT THE LAKE BREEZE BOUNDARY WILL REMAIN VERY
CLOSE IF NOT OVER THE ORD AND MDW AIRFIELDS THROUGH 2330Z.
* HIGH CONFIDENCE THAT CHANCE FOR ISOLATED SHRA/TSRA IS MINIMAL.
* HIGH CONFIDENCE IN WIND TRENDS SATURDAY WITH MEDIUM-HIGH
CONFIDENCE IN TIMING.
* LOW CONFIDENCE IN IF TSRA WILL OCCUR AT THE TERMINALS SATURDAY
BUT SOME ISOLATED TO SCATTERED ACTIVITY IS POSSIBLE IN THE AREA.
MDB/MTF
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SAT NIGHT AND SUN...VFR...SLGT CHC TS.
MON THRU THU...VFR. NO SIG WX.
TRS
&&
.MARINE...
315 PM CDT
A WEAK STATIONARY BOUNDARY STRETCHES FROM EAST CENTER SOUTH DAKOTA
THROUGH SOUTHEAST MICHIGAN. THE BOUNDARY WILL REMAIN AROUND THE
WISCONSIN/ILLINOIS STATE LINE THROUGHOUT THE REST OF THIS AFTERNOON
BEFORE SHIFTING NORTH TOWARD THE CENTRAL LAKE MICHIGAN THIS EVENING.
AN AREA OF WEAK LOW PRESSURE PASSES OVER THE SOUTHERN HALF OF LAKE
MICHIGAN TONIGHT INTO TOMORROW MORNING. MEANWHILE HIGH PRESSURE
SINKS SOUTH OUT OF CANADA AS A COLD FRONT MOVES SOUTHWARD DOWN THE
LAKE. THE FRONT WILL BE SOUTH OF LAKE MICHIGAN BY SATURDAY
AFTERNOON WITH STRONG NORTH TO NORTHEAST WINDS EXPECTED BEHIND THE
FRONT. GUSTS TO 25 KT ARE EXPECTED TONIGHT THROUGH SUNDAY NIGHT
PRIMARILY OVER THE CENTRAL AND SOUTHERN PARTS OF THE LAKE...WITH
PERIODS OF WINDS TO 30 KT POSSIBLE SUNDAY AFTERNOON AND EVENING. A
SMALL CRAFT ADVISORY MAY BE NEEDED FOR SUNDAY AND MONDAY DUE TO THE
HIGHER WINDS AND WAVES. HIGH PRESSURE BUILDS IN BEHIND THE FRONT
AND PASSES OVER THE WESTERN GREAT LAKES TUESDAY AFTERNOON. THE HIGH
CONTINUES EASTWARD AND REACHES NEW ENGLAND BY WEDNESDAY MORNING.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...EXCESSIVE HEAT WARNING...ILZ003-ILZ004-ILZ005-ILZ006-ILZ012-
ILZ013-ILZ014 UNTIL 4 PM SATURDAY.
EXCESSIVE HEAT WARNING...ILZ008-ILZ010-ILZ011-ILZ019-ILZ020-
ILZ021-ILZ022-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 7 PM
SATURDAY.
IN...EXCESSIVE HEAT WARNING...INZ001-INZ002 UNTIL 4 PM SATURDAY.
EXCESSIVE HEAT WARNING...INZ010-INZ011-INZ019 UNTIL 7 PM
SATURDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
318 PM CDT FRI JUL 6 2012
.DISCUSSION...
315 PM CDT
SHORT TERM...TODAY THROUGH SATURDAY NIGHT...
A WEAK STATIONARY FRONT LIES ACROSS THE WISCONSIN/ILLINOIS BORDER
WITH A LAKE BREEZE SLOWLY PUSHING INTO NORTHEAST IL. SCT CU HAS
DEVELOPED ALONG THE LAKE BREEZE...HOWEVER NOT EXPECTING WIDESPREAD
CONVECTION TO DEVELOP. LATEST RUC ANALYSIS INDICATES 3000+ J/KG OF
SFC BASED CAPE ALONG THE LAKESHORE...HOWEVER SUSPECTING THE 100
J/KG OF CIN IS HOLDING CONVECTION BACK. AMDAR SOUNDINGS ALSO
INDICATE THERE IS A SMALL CAP IN THE VICINITY OF THE LAKE BREEZE.
UNLIKE YESTERDAY...THERE IS NO SIGNIFICANT FORCING FEATURE IN THE
REGION OUTSIDE OF THE LAKE BREEZE...AND THE LAKE BREEZE IS NOT
VERY SIGNIFICANT WITH LIGHT WINDS ON BOTH SIDES OF IT. AS
SUCH...AN ISOLATED STORM COULD FIRE...BUT BETTING AGAINST IT AND
GOING WITH A DRY FORECAST.
TEMPERATURES TONIGHT WILL BE IN THE MID TO UPPER 70S...EXCEPT FOR
LOW 80S DOWNTOWN. HEAT INDICES WILL BE IN THE MID 70S
TONIGHT...EXCEPT FOR MID 80S TO NEAR 90 DOWNTOWN.
A COLD FRONT SINKS SOUTH DOWN THE LAKE TONIGHT...BUT DOES NOT REACH
THE SOUTHERN END OF LAKE MICHIGAN UNTIL SATURDAY AFTERNOON. AS
SUCH...EXPECTING OPPRESSIVE HEAT TO CONTINUE TOMORROW WITH MANY
AREAS ONCE AGAIN SEEING TEMPS AROUND 100 DEGREES. ONLY COOLER SPOTS
WOULD BE NEAR UGN AND ALONG THE LAKEFRONT LATE TOMORROW. WINDS WILL
TURN ON SHORE BEHIND THE FRONT PROVIDING RELIEF TO THE NEARSHORE
REGIONS FIRST. HOWEVER...EXPECTING LAKE FRONT AREAS TO REACH THEIR
DAYTIME MAX IN THE MID TO UPPER 90S BEFORE THE COLD FRONT ARRIVES.
MAX HEAT INDICES WILL BE IN THE UPPER 90S TO 105 DEGREES TOMORROW
EAST OF I-355...WITH 105 TO 119 EXPECTED IN THE OUTLYING AREAS. AS
THE FRONT SINKS SOUTH THROUGH THE CWA...TEMPS WILL DROP
SUDDENLY...BUT EXPECTING DEWPOINTS TO REMAIN IN THE 60S THROUGH
SATURDAY NIGHT. NONETHELESS...LOW TEMPS SATURDAY NIGHT WILL BE IN
THE MID 60S TO AROUND 70...PROVIDING THE FIRST REFRESHING NIGHT IN A
LONG TIME FOR MANY AREAS.
NOT EXPECTING MUCH PRECIP ALONG THE FRONT AS MOISTURE DISSIPATES AS
THE FRONT APPROACHES AND FORCING ALONG THE FRONT IS LESS THAN
IMPRESSIVE. WAS NOT COMFORTABLE GOING WITH A DRY FORECAST...BUT NOT
EXPECTING THE WIDESPREAD RAIN THAT WE NEED. SCATTERED THUNDERSTORMS
ARE POSSIBLE SATURDAY AFTERNOON AND NIGHT. WIND SHEAR IS NOT
FAVORABLE FOR SEVERE WEATHER...AND MODEL SOUNDINGS SUGGEST NO CAPE
TO WORK WITH. HOWEVER WITH INVERTED V SOUNDINGS...STRONG WINDS ARE
POSSIBLE.
JEE
LONG TERM...SUNDAY THROUGH FRIDAY...
THE BIG STORY IS THE END OF THE WITHERING HEAT AND HUMIDITY...AT
LEAST THROUGH THIS EXTENDED PERIOD FORECAST...THOUGH THE 6 TO 10/8
TO 14 DAY OUTLOOKS FROM CPC SUGGEST VERY WARM CONDITIONS MAY BE IN
STORE AGAIN BEYOND DAY 7. UNFORTUNATELY...NO RELIEF IS IN SIGHT FOR
THE WORSENING DROUGHT CONDITIONS ACROSS THE REGION...THOUGH AFTER
THE SEEMINGLY ENDLESS HEAT WAVE...CONDITIONS WILL BE QUITE PLEASANT
FOR OUTDOOR ACTIVITIES.
BLOCKING IN THE NORTH ATLANTIC WILL KEEP THE PATTERN VERY SLOW
MOVING...BUT A LONG WAVE TROUGH CURRENTLY NEAR HUDSON BAY WILL BE
ABLE TO KNOCK DOWN THE EVER PRESENT INTENSE MIDLEVEL RIDGE THAT HAS
BEEN PARKED OVER THE CENTRAL CONUS. THIS WILL SHIFT THE UPPER LEVEL
PATTERN TO ONE CHARACTERIZED BY RIDGING OVER THE INTERIOR WEST AND
LONG WAVE TROUGHING STRETCHING DOWN FROM EASTERN CANADA TO THE
MIDWEST AND NORTHEAST.
THE FRONT WILL HAVE PROGRESSED THROUGH THE CWA ON SUNDAY...WITH GOOD
COOL ADVECTION IN ITS WAKE MERCIFULLY KEEPING TEMPERATURES IN THE
80S...EXCEPT SLIGHTLY COOLER ON THE LAKEFRONT WITH PERSISTENT
NORTH/NORTHEAST FLOW. AIR MASS BEHIND THE FRONT WILL ALSO BE MUCH
DRIER AND COMFORTABLE...AS DEWPOINTS DROP INTO THE 50S AND POSSIBLY
EVEN 40S IN THE NORTHERN CWA LATER IN THE DAY. SOME GUIDANCE TRYING
TO HINT AT POST FRONTAL ISOLATED SHRA/TSRA SUNDAY...BUT WILL SHIFT
INHERITED SLIGHT POPS TO SOUTHERN CWA WHERE FORECAST SOUNDINGS SHOW
DECENT ELEVATED INSTABILITY THROUGH SUNDAY AFTERNOON.
AFTER SUNDAY...NO REAL CONCERNS TO SPEAK OF...OTHER THAN CONTINUED
LACK OF RAINFALL...WHICH IS A CONCERN IN THIS WORSENING DROUGHT.
SURFACE HIGH PRESSURE WILL BUILD SOUTH OVER WESTERN GREAT LAKES
REGION AND BLOCKY WEATHER PATTERN WILL KEEP THE HIGH LOCKED OVERHEAD
FOR MUCH OF THE WEEK...FAVORING SYNOPTIC NORTH/NORTHEAST FLOW
SHIFTING TO GENERALLY LIGHT WINDS AND AFTERNOON LAKE BREEZES.
TEMPERATURES WILL START OUT NEAR SEASONABLE...WARMEST ON MONDAY AND
THEN LIKELY WARMING BACK TO A BIT ABOVE NORMAL LATER IN THE WEEK AS
MIDLEVEL HEIGHTS RISE AND TEMPERATURES WARM ALOFT. LIKELY DAILY LAKE
BREEZES WILL KEEP THE LAKEFRONT COOLER...BUT NOT MUCH COOLER AS THE
CONTINUOUS HEAT THIS SUMMER HAS LEFT LAKE MICHIGAN WATER
TEMPERATURES WELL ABOVE NORMAL FOR THIS POINT IN JULY. DESPITE GFS
WANTING TO OCCASIONALLY PAINT QPF WITH HIGH PRESSURE IN THE MIDDLE
OF A DROUGHT...WILL SIDE WITH THE MORE SUPERIOR AND STABLE ECMWF IN
MAINTAINING A DRY FORECAST THROUGH LATE NEXT WEEK.
RC
&&
.CLIMATE...
430 PM CDT
HERE ARE THE RECORDS FOR FRIDAY JULY 6TH...
CHICAGO MAX T...99 IN 1988....HIGH MIN T 80/1977.
ROCKFORD MAX T...102 IN 1936...HIGH MIN T...73/1948.
THE ALL TIME RECORD HIGH FOR CHICAGO IS 105 SET BACK ON JULY 24 1934
AND IN ROCKFORD IS 112 SET ON JULY 14 1936.
FOR CHICAGO THE MOST CONSECUTIVE 100 DEGREE OR HIGHER DAYS IS
THREE...JULY 3RD THROUGH 5TH OF 1911...AND ALSO AUGUST 4TH
THROUGH 6TH OF 1947.
FOR ROCKFORD THE MOST CONSECUTIVE 100 DEGREE OR HIGHER DAYS IS
NINE...JULY 6TH THROUGH 14TH OF 1936.
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* LAKE BREEZE CROSSING THE TERMINALS OVER THE NEXT HOUR...WINDS
TURNING NORTHEASTERLY.
* MINIMAL BUT NON-ZERO CHANCE FOR ISOLATED SHRA/TSRA THIS AFTERNOON.
* WINDS SHIFTING FROM SOUTHWEST TO NORTHEAST MIDDAY SATURDAY WITH
COOL FRONTAL PASSAGE.
* SLIGHT CHANCE SHRA/TSRA SATURDAY.
MDB
//DISCUSSION...UPDATED 20Z...
LAKE BREEZE BOUNDARY NOW REACHING ORD/MDW SHOULD CROSS OVER THE
TERMINALS IN THE NEXT HOUR OR LESS. SCATTERED CU HAS DEVELOPED
NEAR THE BOUNDARY ACROSS THE AREA BUT LATEST AIRCRAFT SOUNDINGS
SHOW AT LEAST SOME INHIBITION KEEPING THE CU FROM DEVELOPING INTO
SHRA/TSRA. NOT A WHOLE LOT OF FORCING OTHER THAN CONVERGENCE ALONG
THE LAKE BREEZE SO THIS CAP MAY HOLD. DESPITE THIS...CANNOT RULE
OUT AN ISOLATED SHRA/TSRA DEVELOPING PRIOR TO 00Z BUT THE CHANCE
IS MINIMAL AND TOO LOW TO INCLUDE IN THE TAF.
MDB
FROM 18Z...
VARIABLE WINDS BETWEEN NORTHWEST AND SOUTHWEST CONTINUE AT THE
TERMINALS WITH LAKE BREEZE BOUNDARY STILL CONTINUING INLAND.
BOUNDARY HAD SLOWED IN THE LAST HALF HOUR BUT HAS NOW STARTED TO
SPEED UP. DID SLOW ARRIVAL TIME AT ORD/MDW AND WILL NEED TO
MONITOR FOR ADJUSTMENTS BUT STILL EXPECT THE BOUNDARY TO CROSS THE
FIELDS. GYY HAS SHIFTED TO THE NORTH WITH THE LATEST OB. THE
BOUNDARY WILL DIMINISH EARLY THIS EVENING AND EXPECT A VARIABLE
BUT MAINLY WEST OR SOUTHWESTERLY WIND TO BE IN PLACE WITH SPEEDS
GENERALLY LIGHT. SOUTHWEST WINDS ARE EXPECTED TO CONTINUE THROUGH
MUCH OF SATURDAY MORNING BUT A COOL FRONT WILL DROP SOUTHWARD
ACROSS THE AREA MIDDAY/EARLY AFTERNOON SHIFTING WINDS TO THE NORTH
AND NORTHEAST. SHOULD SEE SOME GUSTINESS TO AROUND 20 KT DEVELOP
DURING THE LATE AFTERNOON AND EARLY EVENING.
THUNDER CHANCES REMAIN MINIMAL THIS AFTERNOON BUT NOT QUITE ZERO.
FOCUS WOULD BE THE LAKE BREEZE BUT BETTER CHANCE SEEMS TO BE NORTH
OF THE IL/WI STATE LINE. BEYOND THAT...THERE IS A SLIGHT CHANCE
FOR SHRA/TSRA SATURDAY AHEAD AND BEHIND THE FRONT SATURDAY. CHANCE
IS LOW AND COVERAGE LOOKS TO BE ISOLATED TO SCATTERED SO WILL
LEAVE THE TAF DRY FOR NOW.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN LAKE BREEZE CROSSING THE TERMINALS OVER THE
NEXT HOUR.
* HIGH CONFIDENCE THAT CHANCE FOR ISOLATED SHRA/TSRA IS MINIMAL.
* HIGH CONFIDENCE IN WIND TRENDS SATURDAY WITH MEDIUM-HIGH
CONFIDENCE IN TIMING.
* LOW CONFIDENCE IN IF TSRA WILL OCCUR AT THE TERMINALS SATURDAY
BUT SOME ISOLATED TO SCATTERED ACTIVITY IS POSSIBLE IN THE AREA.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SAT NIGHT AND SUN...VFR...SLGT CHC TS.
MON THRU THU...VFR. NO SIG WX.
TRS
&&
.MARINE...
315 PM CDT
A WEAK STATIONARY BOUNDARY STRETCHES FROM EAST CENTER SOUTH DAKOTA
THROUGH SOUTHEAST MICHIGAN. THE BOUNDARY WILL REMAIN AROUND THE
WISCONSIN/ILLINOIS STATE LINE THROUGHOUT THE REST OF THIS AFTERNOON
BEFORE SHIFTING NORTH TOWARD THE CENTRAL LAKE MICHIGAN THIS EVENING.
AN AREA OF WEAK LOW PRESSURE PASSES OVER THE SOUTHERN HALF OF LAKE
MICHIGAN TONIGHT INTO TOMORROW MORNING. MEANWHILE HIGH PRESSURE
SINKS SOUTH OUT OF CANADA AS A COLD FRONT MOVES SOUTHWARD DOWN THE
LAKE. THE FRONT WILL BE SOUTH OF LAKE MICHIGAN BY SATURDAY
AFTERNOON WITH STRONG NORTH TO NORTHEAST WINDS EXPECTED BEHIND THE
FRONT. GUSTS TO 25 KT ARE EXPECTED TONIGHT THROUGH SUNDAY NIGHT
PRIMARILY OVER THE CENTRAL AND SOUTHERN PARTS OF THE LAKE...WITH
PERIODS OF WINDS TO 30 KT POSSIBLE SUNDAY AFTERNOON AND EVENING. A
SMALL CRAFT ADVISORY MAY BE NEEDED FOR SUNDAY AND MONDAY DUE TO THE
HIGHER WINDS AND WAVES. HIGH PRESSURE BUILDS IN BEHIND THE FRONT
AND PASSES OVER THE WESTERN GREAT LAKES TUESDAY AFTERNOON. THE HIGH
CONTINUES EASTWARD AND REACHES NEW ENGLAND BY WEDNESDAY MORNING.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...EXCESSIVE HEAT WARNING...ILZ003-ILZ004-ILZ005-ILZ006-ILZ012-
ILZ013-ILZ014 UNTIL 4 PM SATURDAY.
EXCESSIVE HEAT WARNING...ILZ008-ILZ010-ILZ011-ILZ019-ILZ020-
ILZ021-ILZ022-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 7 PM
SATURDAY.
IN...EXCESSIVE HEAT WARNING...INZ001-INZ002 UNTIL 4 PM SATURDAY.
EXCESSIVE HEAT WARNING...INZ010-INZ011-INZ019 UNTIL 7 PM
SATURDAY.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
102 PM EDT FRI JUL 6 2012
.SYNOPSIS...
HIGH PRESSURE WILL MOVE EAST OF THE AREA TODAY. A COLD FRONT WILL
APPROACH LATER TODAY AND CROSS THE REGION TONIGHT. ANOTHER COLD
FRONT WILL CROSS THE REGION SATURDAY NIGHT.&&
.NEAR TERM /THROUGH TONIGHT/...
1 PM UPDATE...CURRENT FORECAST ON TRACK. NO MAJOR CHANGES NEEDED.
PREVIOUS DISCUSSION:
CHALLENGE THIS TERM WILL BE CLOUDS/FOG THIS MORNING AND
CONVECTION LATER TODAY INTO TONIGHT.
THE LATEST IR SATL IMAGERY SHOWING LOW CLOUDS/FOG DEVELOPING AND MOVING
ACROSS THE AREA. THE HRRR WAS HANDLING THIS SET QUITE WELL AND
FOLLOWED W/IT THROUGH THE MORNING HRS. THIS MEANS CLOUDS AND AREAS
OF FOG ACROSS AT LEAST 1/2 OF THE CWA, BUT AS MORNING WEARS ON AND
SUN BEGINS TO WORK ON THE ATMOSPHERE, CLOUDS SHOULD BREAK UP
W/SKIES BECOMING PARTLY TO MOSTLY SUNNY. THIS WILL ALLOW
TEMPERATURES TO RESPOND ACCORDINGLY W/TEMPERATURES MAXING OUT IN
THE 80 FOR THE CWA W/THE EXCEPTION OF THE COAST AS A SEA BREEZE
DEVELOPING THIS AFTERNOON WILL ALLOW FOR COOLER TEMPERATURES RIGHT
AT THE COAST. NOT CONFIDENT ENOUGH TO BRING THE SEA BREEZE FURTHER
INLAND TOWARD THE BANGOR REGION AND DECIDED TO HAVE WARMER
TEMPERATURES THERE.
IN REGARDS TO CONVECTION, THE ATMOSPHERE LOOKS LIKE IT WILL
DESTABILIZE THIS AFTERNOON THANKS IN PART TO HEATING. MDL
SOUNDINGS ESPECIALLY THE NAM RAMP UP THE SBCAPES TO 800-1200
JOULES ACROSS THE NORTH AND WEST. LIS DROP TO -2 TO -5 W/K INDICES
OF 30+. 0-6KM BULK SHEAR IS 30+ KTS. INHIBITING FACTORS ARE DEEP
MOISTURE WHICH ATTM APPEARS TO BE LIMITED TO BELOW 700 MBS AND
LOW/MID LEVEL LAPSE RATES <6.5C/KM. SOME MID LEVEL WARMING WILL
INHIBIT INITATION, BUT THERE DOES APPEAR TO BE SOME COOLING AROUND
00Z AND A MID/UPPER LEVEL SPEED MAX OF 40-50 KTS AS A COLD FRONT
MOVES IN FROM THE WEST. THIS SPEED MAX COULD OFFSET THE WEAKER
LAPSE RATES AND ALLOW FOR CONVECTION W/SOME STORMS TO BE STRONG TO
POSSIBLY SEVERE. WIND LOOKS TO BE THE MAIN THREAT AS FREEZING
LEVELS ARE SHOWN TO BE AT 13+K FT. ANOTHER THING TO NOTE IS THAT
THERE IS DECENT DIRECTIONAL SHEAR IN LLVL WHICH COULD ALLOW FOR
SOME ROTATION IF STRONGER STORMS FIRE. COLLABORATED W/GYX AND SPC
ON THIS POTENTIAL AND THINKING ATTM ANY SEVERITY WILL BE ISOLD AND
KEPT ACROSS THE NORTH AND WEST. THIS WILL NEED TO BE ASSESSED BY
THE DAYCREW. ACTIVITY WILL MOVE TO THE EAST TONIGHT AND WEAKEN AS
FORCING LESSENS W/LEFTOVER SHOWERS. BOOSTED OVERNIGHT MINS USING
THE NAM12 TEMPERATURES.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
A 500 MB LOW WILL REMAIN ACROSS EASTERN QUEBEC THROUGH SUNDAY WITH
WEST TO NORTHWEST FLOW ALOFT CONTINUING THROUGH SUNDAY. THIS WILL
ALLOW A SERIES OF WEAK COLD FRONT TO CROSS THE REGION THROUGH
SUNDAY. THIS WILL BRING THE CHANCE FOR SHOWERS AND THUNDERSTORMS
TO THE REGION ON SATURDAY WITH ONLY AN ISOLATED SHOWER OR
THUNDERSTORM ON SUNDAY. HIGH TEMPERATURES ON SATURDAY WILL RANGE
FRROM THE LOW 80S NORTH AND MID 80S DOWNEAST. HIGHS ON SUNDAY WILL
RANGE FROM THE LOWER 70S NORTH AND MID 70S TO NEAR 80 ON SUNDAY.
LOW SATURDAY NIGHT WILL RANGE FROM THE MID 50S NORTH AND UPPER 60S
DOWNEAST.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
A MAINLY ZONAL FLOW ALOFT WILL PERSIST THROUGH THE MIDWEEK PERIOD.
THIS WILL BRING MAINLY DRY WEATHER TO THE REGION. TEMPERATURES
THROUGH THE PERIOD WILL BE NEAR NORMAL.
&&
.AVIATION /17Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: IFR/MVFR ACROSS THE NORTHERN TERMINALS THIS MORNING AND
PROJECT TO DEVELOP ACROSS KBGR/KBHB FOR A TIME THIS MORNING.
CONDITIONS ARE EXPECTED TO IMPROVE TO VFR BY MID TO LATE MORNING.
SOME CONCERN TO STRONGER TSTMS ACROSS THE NORTHERN TERMINALS LATER
THIS AFTERNOON INTO EARLY TONIGHT WHICH COULD DROP CONDITIONS TO
MVFR FOR A BRIEF TIME. LLWS COULD BE A ISSUE W/THE TSTMS.
SHORT TERM: MAINLY VFR CONDITIONS. COULD BE BRIEF MVFR IN ANY
HEAVIER CONVECTION SATURDAY AFTERNOON.
&&
.MARINE...
NEAR TERM: NO HEADLINES. SE SWELL CONTINUES AND DECIDED TO KEEP IT
GOING THROUGH TONIGHT AS 8-9 SECOND PERIOD. WAVE HEIGHTS OF 2-3 FT
INTO TONIGHT. WINDS WILL BE 10 KTS OR LESS.
SHORT TERM: WINDS/SEAS WILL REMAIN BELOW SCA LEVELS THROUGH THE
PERIOD.
&&
.MARINE...
NEAR TERM:
SHORT TERM:
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HASTINGS/HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HASTINGS/HEWITT
MARINE...HASTINGS/HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS GAYLORD MI
407 PM EDT FRI JUL 6 2012
.SYNOPSIS...
ISSUED AT 404 PM EDT FRI JUL 6 2012
A FRONTAL BOUNDARY OVER THE WESTERN GREAT LAKES...WILL SLOWLY SAG
SOUTHWARD TONIGHT...AND WILL BE OVER SOUTHERN LOWER MICHIGAN
TOMORROW. THIS FRONT WILL BRING SHOWERS AND THUNDERSTORMS TO
NORTHERN MICHIGAN...TONIGHT INTO SATURDAY. MUCH COOLER WEATHER WILL
SETTLE IN BEHIND THE FRONT FOR THE WEEKEND WITH TEMPERATURES MUCH
MORE TYPICAL OF EARLY JULY. HIGH PRESSURE WILL BUILD INTO THE REGION
THIS WEEKEND INTO NEXT WEEK...BRINGING A PROLONGED PERIOD OF FAIR
WEATHER WITH SEASONAL TEMPERATURES.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 404 PM EDT FRI JUL 6 2012
WILL SUM IT ALL UP QUICKLY: CONFIDENCE FOR RAIN TONIGHT INTO
SATURDAY...DECENT...CONFIDENCE ON EXACT LOCATION OF HEAVIEST RAINS
AND SEVERE POTENTIAL...WISH IT WERE BETTER. INTERESTING AND
CHALLENGING FORECAST UNFOLDING...AS TIGHT (AND TIGHTENING) THERMAL
GRADIENT OVER THE NORTHERN LAKES INTERACTS WITH EXCELLENT REMAINING
INSTABILITY GRADIENT AND MOISTURE SURGE. EARLIER WELL ORGANIZED
NORTHERN PLAINS MCS THIS MORNING A BYPRODUCT OF THESE FEATURES...
ALTHOUGH THIS HAS QUICKLY DECAYED WITH DIURNAL DISRUPTION OF LOW
LEVEL JET. EARLY AFTERNOON ANALYSIS SHOWS PLENTY OF POTENTIAL FOR
ANOTHER AREA OF SHOWER AND THUNDERSTORMS DEVELOPING OVER THE
NORTHWEST LAKES (ALREADY BEGINNING TO RAMP UP OVER WESTERN LAKE
SUPERIOR)...WITH RAP AND OBSERVATIONAL DATA ALREADY SHOWING A WELL
ORGANIZED THERMAL GRADIENT OVER THE NORTHERN LAKES...COUPLED NICELY
WITH CORRIDOR OF AOA 1.75 INCH PWAT VALUES. ALL TRENDS SUPPORT THE
ABOVE AFFECTING AT LEAST PARTS OF OUR AREA TONIGHT INTO SATURDAY
MORNING. FORECAST CONCERNS CENTER ON THIS POTENTIAL...SPECIFICALLY
PLACEMENT OF STEADIER RAINS AND ISOLATED SEVERE POTENTIAL (IF ANY).
THERMAL GRADIENT WILL CONTINUE TO TIGHTEN OVER THE FAR NORTHERN
LAKES THIS EVENING...AS REGION COMES UNDER THE SQUEEZE PLAY OF
SURFACE TROUGH DROPPING SOUTHEAST OUT OF CANADA...AND RENEWED SURGE
OF WARMTH/MOISTURE FROM THE WESTERN LAKES AHEAD OF WEAK LOW PRESSURE
PIVOTING INTO SOUTH CENTRAL WISCONSIN. 850-750MB FGEN CIRCULATION
WILL RAMP UP QUICKLY AS A RESULT (ALMOST A CLASSIC COOL SEASON LOOK
TO IT)...WITH CURRENT TRENDS SUPPORTING INTENSE LIFT WARM CORE SIDE
OVER EASTERN UPPER MICHIGAN AND FAR NORTHERN LOWER MICHIGAN. THIS
ALONE SHOULD BE ENOUGH TO KICK OFF A DECENT AREA OF RAIN OVER THAT
AREA...SLOWLY DROPPING SOUTH LATER TONIGHT AS THERMAL GRADIENT DOES
THE SAME. IN ADDITION...STILL PLENTY OF CONCERNS FOR RENEWED MCS
DEVELOPMENT OVER WISCONSIN THIS EVENING AS WEAKISH LOW LEVEL JET
INTERACTS WITH A WARM FRONT SLOWLY BOWING NORTH ACROSS THE BADGER
STATE. NOT NEARLY AS CONFIDENT ON THIS SCENARIO (WEAK JET)...BUT
WILL NEED TO BE WATCHED AS ANY SYSTEM WILL RIDE EAST/SOUTHEAST JUST
NORTH OF THE SURFACE MOISTURE/INSTABILITY GRADIENT STRETCHED OVER
CENTRAL MICHIGAN. WHILE BEST MID LEVEL WINDS WILL RESIDE TO THE
NORTH...NAM-WRF MU CAPE ANALYSIS SHOWS UPWARDS OF 2K J/KG OF CAPE
LIFTING A PARCEL FROM 800MB...SUPPORTING AN ISOLATED HAIL/DAMAGING
WIND EVENT (ESPECIALLY IF UPSTREAM COLD POOLS CONGEAL). WHILE THIS
IS A LOW THREAT SCENARIO...HARD TO COMPLETELY IGNORE LATEST SPC
SLIGHT RISK STRETCHING INTO SOUTHWEST PARTS OF OUR CWA. THIS IS ALL
CONTINGENT ON WHAT CAN DEVELOP UPSTREAM THIS EVENING. KINDA A WHAT
AND SEE APPROACH.
THE RELIEF BEGINS SATURDAY AS THE COLD FRONT CLEARS. STILL EXPECT
SOME LINGERING RAINS...ESPECIALLY THE FIRST HALF OF THE DAY. BIGGER
STORY WILL BE THOSE TEMPERATURES...WITH HIGHS BACK DOWN INTO THE
UPPER 70S AND LOWER 80S. ENJOY!
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 404 PM EDT FRI JUL 6 2012
STABLE 5-WAVE NORTHERN HEMISPHERIC PATTERN IN PLACE TO START WITH
ONE LEG OF TROUGHINESS THROUGH EASTERN CANADA AND NEW ENGLAND AND
ANOTHER OFF THE PACIFIC COAST. MEDIUM RANGE GUIDANCE STILL SUGGESTS
LITTLE CHANGES TO THIS CONFIGURATION THROUGH MIDWEEK ALTHOUGH LONG
WAVE TROUGHINESS DOES DEEPEN ACROSS THE EASTERN CONUS WHILE SHARPER
RIDGING BUILDS OUT WEST. THIS PATTERN HOLDS THROUGH MIDWEEK BEFORE
THE ENTIRE NORTH AMERICA PATTERN FLATTENS/DE-AMPLIFIES LATE NEXT
WEEK ALLOWING SOME HEAT TO RETURN TO THE REGION. UPSHOT TO ALL
THIS...WILL GET A BREAK FROM THE BIG TIME HEAT THAT HAS BEEN
IMPACTING THE PLAINS AND GREAT LAKES OF LATE BUT WITH TEMPERATURES
STARTING TO CLIMB BACK UP LATE NEXT WEEK. OTHERWISE...A PROLONGED
QUIET STRETCH OF WEATHER ANTICIPATED AS HIGH PRESSURE BUILDS FROM
THE PLAINS THROUGH THE GREAT LAKES.
SATURDAY NIGHT THROUGH MONDAY...IN THE WAKE OF TONIGHTS/SATURDAYS
SYSTEM...HIGH PRESSURE BEGINS TO BUILD FROM THE NRN PLAINS INTO THE
NRN LAKES...SUPPRESSING THE TIGHT MOISTURE GRADIENT DOWN INTO THE
OHIO VALLEY BY SUNDAY...BRINGING NOTICEABLE RELIEF FROM THE
HEAT/HUMIDITY TO WRAP UP THE WEEKEND. SHOULD BE A QUIET STRETCH OF
WEATHER. ALTHOUGH WITH THAT SAID...GUIDANCE DOES SHOW A WEAKER MID
LEVEL IMPULSE DIGGING DOWN THROUGH THE GREAT LAKES SUNDAY NIGHT
THROUGH MONDAY...AS THE UPPER TROUGHINESS DEEPENS IN THE EAST.
COMBINED WITH DAYTIME HEATING/COOLER AIR ALOFT...MIGHT RESULT IN A
LOW END SHOWER THREAT ON MONDAY. CHANCES APPEAR MUCH TO LOW TO MUDDY
THE FORECAST AT THIS TIME...BUT WILL NEED TO KEEP AN EYE ON THIS
POTENTIAL. TEMPERATURES WILL BE SEASONABLE...MID 70S TO AROUND 80
FOR HIGHS.
LATER PERIODS (TUESDAY THROUGH FRIDAY)...BROAD AREA OF HIGH PRESSURE
SLOWLY MIGRATES THROUGH THE GREAT LAKES WHILE WEAKENING IN TIME. AS
MENTIONED ABOVE...OVERALL FLOW PATTERN EXPECTED TO DE-AMPLIFY/
FLATTEN AS WE GO THROUGH THE WEEK ALLOWING WARMER AIR TO MIGRATE
BACK THROUGH THE MIDWEST AND GREAT LAKES FOR LATER IN THE WEEK. NOT
A RETURN TO THE OPPRESSIVE HEAT OF LATE...BUT DAYTIME TEMPS WARMING
TO THE LOWER TO MIDDLE 80S A GOOD BET.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 200 PM EDT FRI JUL 6 2012
QUIET LATE AFTERNOON WILL GIVE WAY TO INCREASING RAIN CHANCES
LATER THIS EVENING AND OVERNIGHT...WITH INITIALLY BETTER COVERAGE
OF RAIN ACROSS THE NORTH...SLOWLY SIDING SOUTH EARLY SATURDAY
MORNING. THUNDER THREAT REMAINS POSSIBLE...ESPECIALLY IF UPSTREAM
CONVECTIVE COMPLEX IS REALIZED LATER TODAY. WILL CONTINUE TO HEDGE
PARTIALLY TOWARDS THIS SCENARIO...INTRODUCING VCTS WITH THE
INCOMING RAINS. SOME POSSIBILITY MVFR/IFR CIGS/VIS WILL BE
REALIZED IN THE HEAVIER SHOWERS...JUST NOT NEARLY CONFIDENT ENOUGH
TO GO THAT ROUTE JUST YET. LIGHT WINDS WILL CONTINUE...BECOMING
NORTH TO NORTHEAST SATURDAY MORNING BEHIND A COLD FRONTAL PASSAGE.
&&
.MARINE...
ISSUED AT 404 PM EDT FRI JUL 6 2012
LAKE BREEZE DOMINATE FLOW WILL BECOME MORE NORTHERLY TOMORROW AS
THE LOW PRESSURE TO OUR WEST TRACKS EAST OF US...WHILE ALSO
PRODUCING A SWATH OF RAIN...AS WELL AS POTENTIAL THUNDERSTORMS
LAKES MICHIGAN AND HURON. HIGH PRESSURE WILL AGAIN BUILD BACK INTO
THE REGION OVER THE NEXT SEVERAL DAYS...BRINGING COOLER AIR AND
PLENTY OF SUNSHINE. OUTSIDE OF SOME FOG...ESPECIALLY IN THE ST
MARYS RIVER SYSTEM...NO MARINE ISSUES FORESEEN FOR THE NEXT
SEVERAL DAYS.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
SYNOPSIS...NS
SHORT TERM...MB
LONG TERM...BA
AVIATION...MB
MARINE...SD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
139 PM EDT FRI JUL 6 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 522 AM EDT FRI JUL 6 2012
WV IMAGERY AND RUC ANALYSIS SHOWS AN UPPER RIDGE OVER THE CNTRL
CONUS AND AN UPPER LOW OVER HUDSON BAY SUPPRESSING THE NRN EXTENT
OF THE UPPER RIDGE. SHORTWAVE IN ERN MONTANA IS ROTATING NNE UP THE
RIDGE AND THE SHORTWAVE COMBINED WITH A SFC LOW IN ERN SD HAS
CONTINUED TO PRODUCE A LARGE THUNDERSTORM COMPLEX IN NCNTRL SD AND
CNTRL ND. CLOSER TO UPPER MI...SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS HAVE DEVELOPED OVER THE LAST COUPLE HOURS IN
CNTRL/NRN MN ASSOCIATED WITH H700-500 MOISTURE AND EDGE OF
EXITING 6.5-7.5 C/KM LAPSE RATES. WITH THE RIDGE IN PLACE...EXPECT
THE SHOWERS TO CONTINUE NNE EARLY THIS MORNING DUE TO THE
RIDGE...WHILE THE STEEPER LAPSE RATES SHIFT E. THIS SHOULD KEEP
PCPN MAINLY TO THE W OF LK SUPERIOR...ALTHOUGH THERE ARE SOME HINTS
OF IT TRYING TO BUILD E TOWARDS THE LK. OVER UPPER MI...HIGH
PRESSURE RIDGE IS IN PLACE AND HAS LED TO CLEAR SKIES AND
TEMPERATURES IN THE 60S.
THE HIGH PRESSURE SHOULD LEAD TO A SUNNY START TO THE DAY...WITH
MID CLOUDS PUSHING EAST INTO THE WRN CWA AS THE DAY GOES ON. H850
TEMPS ARE SLIGHTLY COOLER TODAY BEHIND THE COLD FRONT WHICH WILL
LEAD TO HIGHS IN THE 80S...WITH A FEW 90S OVER THE SCNTRL. SLIGHTLY
COOLER VALUES ARE EXPECT NEAR LK SUPERIOR DUE TO LIGHT NRLY FLOW
AROUND THE HIGH WHICH WILL LEAD TO LK BREEZE DEVELOPMENT. TD
VALUES WILL BE MUCH LOWER THAN YEST...IN THE 50S...AND
WHEN COMBINED WITH THE LOWER TEMPS WILL MAKE IT FEEL MUCH MORE
COMFORTABLE OUTSIDE.
ATTENTION THEN TURNS TO THE UPSTREAM CONVECTION AS IT WILL BE THE
MAIN WEATHER MAKER FOR THE SHORT TERM. SHORTWAVE IN NRN WYOMING AND
ERN MONTANA WILL BE ROTATING AROUND THE UPPER RIDGE THAT HAS BEEN
CAUSING THE WARM/HUMID WEATHER...ALONG WITH BOUTS OF THUNDERSTORMS.
THIS WILL ONCE AGAIN BE THE CASE WITH THIS SHORTWAVE...WHICH
PRODUCED CONVECTION OVER NWRN SD/ND OVERNIGHT AND WILL BRING ANOTHER
PERIOD OF MODERATE RAIN. EVEN THOUGH THE BEST INSTABILITY GRADIENT
STRETCHES FROM ND SE THROUGH CNTRL WI...THINK THE UPPER RIDGE WILL
STEER THE CURRENT CONVECTION MORE TO THE NE THROUGH THE MORNING
HOURS.
BEST AREA OF THE WEAK SHORTWAVE ENERGY WILL SLIDE ACROSS THE NRN
HALF OF THE CWA LATE THIS AFTN AND TONIGHT...ALONG WITH THE H500
HEIGHT FALLS. THIS WILL COINCIDE WITH THE RIGHT ENTRANCE OF THE
UPPER JET ROTATING AROUND THE UPPER LOW OVER HUDSON BAY. FARTHER TO
THE S...STRONG FGEN FROM H800 TO H650...WILL BE OVER WRN LK SUPERIOR
LATE THIS AFTN AND EVENING AND THEN SHIFT SSE TONIGHT. AS EXPECTED
TIGHT H850 THERMAL GRADIENT AND WAA/ISENTROPIC ASCENT OVER SRN UPPER
MI. THUS...EXPECT BEST PCPN CHANCES FROM WRN LK SUPERIOR THROUGH WRN
UPPER MI AND THEN SLIDING SE ACROSS ERN UPPER MI OVERNIGHT WITH A
STRONGER NRLY H850 PUSH AND VEERING WINDS TO THE EAST S OF THE H850
FRONT. OVER THE NRN PART OF LK SUPERIOR...LLVL DRY AIR AND DOWNWARD
AGEOSTROPHIC CIRCULATION MAY END UP LIMITING THE NRN EXTENT OF
THE PCPN.
FAIRLY GOOD CONSENSUS IN THE 00Z MODELS ON THE QPF AMNTS...AS
THEY RANGE FROM SWATHS OF 1-1.7IN ON THE NAM/GEM-REG TO 0.5-0.75IN
ON ECMWF/GFS. ECMWF IS SLIGHTLY FARTHER S THAN THE OTHER TWO...WITH
THE GFS SLIGHTLY FARTHER TO THE NW. LOOKING AT THE 21Z SREF
RUN...IT HAS A 30 PERCENT PROB OVER WRN U.P. OF 1.0IN OF RAIN
TONIGHT AND 50-70 PERCENT OF 0.5 OVER THE W HALF. PWATS ARE AROUND
150-200 PERCENT OF NORMAL...WHICH WOULD SUPPORT THE POSSIBILITY OF
CORRIDORS OF HEAVY RAIN. HAVE BUMPED UP QPF AMNTS SOME AND HAVE
TOTAL AMNTS WITH THIS SYSTEM OF 0.75-1.0IN OVER THE INTERIOR WEST.
WITH THESE AMNTS...WILL NEED TO WATCH IRON COUNTY AND PAINT RIVER
WITH THE ABUNDANCE OF RAIN THEY HAVE SEEN IN THE LAST WEEK /RADAR
ESTIMATED OVER 8IN/. FARTHER TO THE EAST...THINK THE VEERING H850
WINDS WILL REALLY DIMINISH AMNTS AND HAVE LESS THAN 0.5IN E OF
MUNISING/MANISTIQUE.
FINALLY...THE CONVECTIVE POTENTIAL. H850 LIFTED ELEVATED CAPE
GRADIENT IS RIGHT ALONG WI BORDER. IT IS A VERY SKINNY CAPE...WITH
NCAPE VALUES AROUND .08...AND EFFECTIVE SHEAR VALUES AROUND 30KTS
WOULD INDICATE LIMITED POTENTIAL FOR HAIL. 3HR SPC CALIBRATED
THUNDER PROBS INDICATE THE BEST CHANCES ALONG THE WI BORDER
TONIGHT...WHICH MATCHES UP WELL WITH INSTABILITY GRADIENT AND
POTENTIAL CONVECTION DEVELOPING IN CNTRL MN AND NW WI.
THEREFORE...WILL LIMIT CHANCE THUNDER TO THE WI BORDER AND JUST HAVE
SLIGHT CHANCE OVER ALL BUT THE FAR N.
AT THE PRESENT TIME...FEEL FAIRLY CONFIDENT IN THE GOING FORECAST.
ONLY HAVE TWO CONCERNS. ONE...IF THE CONVECTION CURRENTLY GOING IN
NCNTRL SD CAN STAY ON THE INSTABILITY GRADIENT AND HOLD OFF THE
STEERING FROM THE RIDGE...WHICH DOESN/T SEEM TOO LIKELY.
TWO...WOULD BE IF CONVECTION THAT MAY FIRE ALONG THE WARM FRONT AND
INSTABILITY GRADIENT IN CNTRL MN AND NW WI THIS AFTN...WHICH COULD
DISRUPT SOME OF THE LLVL FLOW AND MOISTURE ADVECTION INTO THIS
AREA. BUT WITH THE WAY THE CONVECTION AND SHOWERS HAVE BEEN GOING
IN THE DAKOTAS...FEEL THAT MUCH OF THE AREA WOULD STILL SEE RAIN
IF THAT OCCURS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 522 AM EDT FRI JUL 6 2012
SATURDAY...HIGH PRESSURE AND STRONG DRYING BEHIND THE FRONT SAGGING
TO THE SOUTH WILL BRING CLEARING SKIES AFTER ANY ANY LEFTOVER LIGHT
SHOWERS OVER THE SOUTH EARLY. MAX READINGS SHOULD ALSO BE LOWER WITH
INLAND READINGS IN THE UPPER 70S AND LOWER 80S AS 850 MB TEMPS DROP
INTO THE 12C TO 14C RANGE. LIGHT NRLY GRADIENT FLOW WILL KEEP TEMPS
MAINLY IN THE LOWER 70S NEAR LAKE SUPERIOR. WITH DEWPOINTS DROPPING
INTO THE 50S...FAVORABLE RADIAIONAL COOLING CONDITIOINS SHOULD ALLOW
TEMPS TO DROP INTO THE LOWER TO MID 50S INLAND.
SUNDAY...THE COMBINATION OF A WEAK SHORTWAVE DROPPING INTO THE AREA
IN THE NW FLOW PATTERN AND SBCAPE VALUES INTO THE 400-600 J/KG RANGE
DURING PEAK HEATING MAY BE ENOUGH TO TRIGGER SOME ISOLD INLAND
SHRA/TSRA OVER THE INTERIOR WEST. HOWEVER...ANY RAINFALL AMOUNTS
WOULD BE LIGHT. EVEN THOUGH SEVERAL MODELS SUGGEST THAT ANOTHER WEAK
SHORTWAVE SUNDAY NIGHT MAY ALSO PRODUCE SOME LIGHT SHOWERS...GIVEN
THE GENERALLY DRY AIRMASS...PREFERRED THE ECMWF WHICH DOES NOT SHOW
ANY QPF.
MONDAY THROUGH THURSDAY...A MORE AMPLIFIED PATTERN WITH A MID/UPPER
LEVEL RIDGE OVER WRN NOAM WILL RESULT IN CONTINUED NW FLOW THROUGH
THE WRN GREAT LAKES. THE POTENTIAL ALSO REMAINS FOR WEAK SHORTWAVES
TO MOVE THROUGH THE AREA WITH LOWER END PCPN CHANCES.
HOWEVER...CONFIDENCE IN THE TIMING/STRENGTH OF THESE FEATURES IS
LOW. TENDED TO FAVOR THE DRIER ECMWF QPF...GIVEN THE GFS MOISTURE
BIAS. TEMPERATURES WILL REMAIN CLOSER TO SEASONAL AVERAGES WITH
HIGHS IN THE LOW TO MID 70S MON CLIMBING TO THE UPPER 70S AND LOWER
80S BY WED-THU.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 138 PM EDT FRI JUL 6 2012
VERY COMPLEX FORECAST EVOLVING THROUGHOUT THE TAF PERIOD AS ONGOING
SHRA HAVE BEEN FORMING IN WAVES FROM WESTERN UPPER MI INTO NORTHERN
MN. ATTEMPTED TO TIME OUT THESE WAVES OF PRECIP AT EACH SITE...BUT
POCKETS OF SMALLER -SHRA COULD DEVELOP DURING THE LULLS. NOT
EXPECTING MUCH THUNDER IN THE FIRST SIX HOURS...SO HAVE LEFT OUT ANY
MENTION. THE MORE DIFFICULT MATTER RESIDES WITH CIG AND VIS.
MOISTURE FROM RAIN AND UPSLOPE FLOW OFF LAKE SUPERIOR WILL AFFECT
IWD AND CMX BEGINNING THIS AFTERNOON...AND SAW IN THE EVENING. NOT
TOO CONFIDENT ON HOW LOW SOME CIGS AND VIS COULD GO AT EACH SITE AS
SEVERAL UPSTREAM OBS ARE SHOWING MVR CIGS...EVEN WITHOUT UPSLOPE AND
LAKE MOISTURE INFLUENCE. IF ENOUGH MOISTURE IS ADVECTED
ONSHORE...MAY EVEN SEE PATCHES OF FOG DEVELOP AT SAW OVERNIGHT.
CONDITIONS WILL BEGIN TO CLEAR IN THE MORNING AT ALL SITES AS DRIER
AIR MOVES IN FROM THE NORTH...THOUGH SOME SCATTERED LOW CLOUDS MAY
REMAIN TRAPPED NEAR THE SURFACE UNTIL WARMING CAN MIX OUT LOW-LEVEL
MOISTURE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 522 AM EDT FRI JUL 6 2012
HIGH PRESSURE OVER LAKE SUPERIOR THIS MORNING WILL KEEP WINDS BELOW
20 KTS TODAY. A LOW PRESSURE TROUGH WILL CROSS JUST S OF UPPER MI
TONIGHT...WHICH WILL SHIFT WINDS MORE TO THE N. BEHIND THIS
TROUGH...HIGH PRESSURE WILL SETTLE BACK OVER THE UPPER GREAT LAKES
THROUGH THE MIDDLE OF NEXT WEEK AND WILL KEEP WINDS LIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...JLB
AVIATION...TK
MARINE...SRF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
242 PM EDT FRI JUL 6 2012
.SYNOPSIS...
UPPER LEVEL HIGH PRESSURE WILL CONTINUE TO EXTEND EAST INTO THE
CAROLINAS OVER THE WEEKEND...RESULTING IN PERSISTENT HOT CONDITIONS.
THE UPPER LEVEL HIGH WEAKENS OVER MUCH OF THE EASTERN UNITED STATES
EARLY NEXT WEEK. A SURFACE FRONT WEAKENS AND STALLS IN VICINITY OF
THE CAROLINAS...MAKING FOR COOLER BUT UNSETTLED WEATHER NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 240 PM FRIDAY...
THE UPPER-LEVEL SHEAR AXIS CONTINUES TO SETTLE SOUTH ON WATER
VAPOR IMAGERY...LOCATED AS OF THIS WRITING JUST NORTH OF THE
VIRGINIA BORDER WITH NORTH CAROLINA. ISOLATED SHOWERS HAVE
DEVELOPED ALONG THE SHEAR AXIS...AS MIXED LAYER CAPE HAS INCREASED
ON THE SPC MESOANALYSIS TO NEAR 1000J/KG ALONG MUCH OF THE
BORDER...AND TO NEAR 2000J/KG OR GREATER NEAR A SURFACE TROUGH
OVER THE NORTHEAST PART OF THE STATE INTO SOUTHEAST VIRGINIA. MSAS
AND THE SPC MESOANALYSIS SHOWS THE GREATER MOISTURE AND
INSTABILITY OVER THE NORTHEAST PART OF THE STATE IN THE VICINITY
OF THE TROUGH...AND WHILE SOME SHORT-TERM MESOSCALE MODELS LEAVE
CENTRAL NORTH CAROLINA DRY...GIVEN THE INSTABILITY...THE SURFACE
TROUGH...AND THE SHEAR AXIS ALOFT...WILL CONTINUE WITH WIDELY
SCATTERED TO SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING MAINLY
ALONG THE VIRGINIA BORDER AND NORTH OF U.S. 64 LATE THIS AFTERNOON
AND EARLY THIS EVENING...GRADUALLY SHIFTING AND DIMINISHING NORTH-
TO-SOUTH DURING THE EVENING AS THE SHEAR AXIS AND ANY LIFT
ASSOCIATED WITH IT MOVES SOUTH. BOTH THE NAM AND THE GFS SHIFT
THIS SHEAR AXIS SOUTH OF THE STATE BY AROUND 06Z. THE RAP IS ONE
SHORT-TERM MODEL THAT PORTRAYS A SCENARIO AS WILL BE FORECAST...WITH
THE LEAST CHANCES LATE THIS AFTERNOON AND VERY EARLY THIS EVENING
OVER THE SOUTHWEST PIEDMONT. GIVEN THAT THE DOWNDRAFT CAPE IS ON
THE ORDER OF 1000J/KG...AN ISOLATED DAMAGING WIND THREAT IS
POSSIBLE IF A STORM CAN DEVELOP AND GET STRONG ENOUGH. IN FACT...
CUMULUS WAS FINALLY STARTING TO DEVELOP ON VISIBLE IMAGERY OVER
PARTS OF SOUTHEAST VIRGINIA AS WELL.
OVERNIGHT...ANY LINGERING SHOWERS SHOULD DIMINISH AS THE SHEAR
AXIS MOVES SOUTH AND SUBSIDENCE INCREASES...LIKELY LAST AROUND
THE SOUTH CAROLINA BORDER BY AROUND MIDNIGHT. OVERNIGHT LOW
TEMPERATURES SHOULD FALL TO 70 TO 75 IN MOST LOCATIONS. WARMEST
WILL LIKELY BE AROUND KMEB AND KFAY...WITH LOWS SOLIDLY NEAR 75.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 240 PM FRIDAY...
THE HEAT ADVISORY CONTINUES FOR SATURDAY...WITH THE CONSENSUS OF
1000-850MB THICKNESSES FROM THE NAM AND GFS GENERALLY SUPPORTIVE
OF THE WARMER MOS GUIDANCE VALUES FOR HIGHS. USING A BLEND OF DEW
POINTS FROM THE GFS...NAM...AND LATEST VERSIONS OF THE SREF AND
ECMWF...AND TRYING TO IGNORE EXTREMES...MAXIMUM APPARENT
TEMPERATURES FOR SATURDAY AFTERNOON END UP BEING FORECAST FROM
104 OR 105 TO AS HIGH AS 109 IN MOST AREAS EAST AND SOUTH OF THE
IMMEDIATE TRIAD. DEPENDING ON HOW FAST THE TEMPERATURE WARMS
BEFORE SOME MODEST MIXING OF DEW POINTS OCCUR...IT IS POSSIBLE
THAT FOR AN HOUR OR SO HEAT INDICES COULD REACH 110 MAINLY TOWARD
KMEB AND KFAY. COORDINATED WITH KILM...AND FOR THIS ISSUANCE WILL
CONTINUE WITH THE HEAT ADVISORY...EXPANDING IT WEST TO INCLUDE
RANDOLPH AND ALAMANCE COUNTIES IN COORDINATION WITH KRNK...AND
ALSO WHERE THE CURRENTLY FORECAST HEAT INDICES GET VERY CLOSE TO
105.
TEMPERATURES ALOFT WARM A LITTLE ON BOTH GFS AND NAM BUFR SOUNDINGS...
WITH LITTLE MOISTURE ALOFT AND A MID-LEVEL CAP THAT WILL BE DIFFICULT
TO OVERCOME. NAM DOES FORECAST A WEAK 700MB SHEAR AXIS MOVING
THROUGH SATURDAY AFTERNOON...AND THE BUFR SOUNDINGS ESPECIALLY
TOWARD KFAY AND KRWI SATURDAY AFTERNOON SHOW A MORE MODEST CAP.
1000-500MB LAPSE RATES ARE ONLY AROUND 6.5C/KM...WITH SOME
DIMINISHING MOISTURE IN TERMS OF PRECIPITABLE WATER FROM THE NORTH...
TO AT OR BELOW 1.5 INCHES ESPECIALLY TOWARD THE VIRGINIA BORDER
WHICH LEAVES PART OF CENTRAL NORTH CAROLINA NORTH OF U.S. 64
ACTUALLY AT OR MAYBE JUST A TOUCH BELOW NORMAL FOR JULY. UNDER
EXPANDING HIGH PRESSURE ALOFT...IT WILL PROBABLY BE DIFFICULT TO
GENERATE DEEP CONVECTION...BUT IN A HOT AIR MASS WITH AT LEAST
SOME MOISTURE...BETTER SOUTHEAST...WILL CONTINUE WITH THE SLIGHT
CHANCE OF A LATE AFTERNOON SHOWER OR STORM. IF ONE WOULD OCCUR...
LIKELY THE BEST CHANCE WILL BE EAST OF A LINE FROM KMEB TO KRWI.
ANY DEEP CONVECTION DIMINISHES DIURNALLY...AND TEMPERATURES WILL
BE SLOW TO FALL...WITH LOWS OVERNIGHT IN THE MID 70S AS A RULE
ACROSS CENTRAL NORTH CAROLINA. LOWS SHOULD BE WARMER...IN PART...
DUE TO A GRADUALLY INCREASING SURFACE GRADIENT AS THE FRONT
CURRENTLY WELL TO OUR NORTH STARTS ITS SLOW PUSH SOUTH. - DJF
SUNDAY WILL SEE THE PATTERN BEGINNING TO SHIFT WITH THE MID LEVEL
RIDGE CENTERED OVER THE CAROLINAS BEGINNING TO SHIFT EASTWARD AS THE
LONGWAVE TROUGH OVER NE NOAM BEGINS TO DEEPEN. AT THE SURFACE...A
COLD FRONT WILL GRADUALLY DRIFT SOUTH ACROSS THE OHIO RIVER VALLEY
AND NORTHERN MID ATLANTIC REGION. ACROSS OUR AREA...SUBTLE CHANGES
WITH REGARD TO THE SFC PRESSURE PATTERN AND THERMODYNAMIC PROFILE...
NOTED SUBTLE WARMING AT 850 MB AND LOLEV THICKNESS INCREASE OF ABOUT
10M SUGGEST HIGHS ONCE AGAIN AROUND 100 WITH HEAT ADVISORY
CONDITIONS LIKELY. BASED ON WARMING AND AN UPTICK IN MOISTURE AHEAD
OF THE FRONT...WE CANNOT RULE OUT THE POSSIBILITY OF THE HEAT
INDEX REACHING 110+ AT SEVERAL LOCATIONS (ESP ACROSS OUR EASTERN
ZONES)...SO EXCESSIVE HEAT WATCHES/WARNINGS MAY BE NEEDED. THIS
WILL BE THE LAST HOT DAY IN THIS STRING OF ABOVE NORMAL
TEMPERATURE DAYS. AS FOR PRECIP POTENTIAL...FORECAST SOUNDINGS
SHOW SLIGHTLY MORE UNSTABLE ENVIRONMENT COMPARED TO SATURDAY...
WITH THE MID LEVELS COOLING ABOUT 2C AND AFOREMENTIONED LOW LEVEL
WARMING. NOTED FAIRLY WEAK SHEAR WITH THE MID LEVEL RIDGE AXIS
SLOWLY DEPARTING...THUS ISOLATED TO SCATTERED MAINLY PULSE- TYPE
TSTMS WILL BE POSSIBLE DURING THE AFTERNOON AND EVENING HOURS.
SUNDAY NIGHT THE COLD FRONT ACROSS THE NORTHERN MID ATLANTIC WILL
CONTINUE TO SLOWLY DRIFT SOUTH TOWARD OUR AREA AS THE LONGWAVE
TROUGH TO OUR NORTH CONTINUES TO DEEPEN. WILL KEEP CHANCE POPS GOING
OVERNIGHT WITH BEST CHANCE ACROSS OUR NORTHERN HALF GIVEN CLOSER
PROXIMITY TO THE FRONT. LOWS SUNDAY NIGHT REMAINING WARM AHEAD OF
THE FRONT (LOW-MID 70S). - NMP
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 240 PM FRIDAY...
MODELS CONTINUE TO SHOW THE PATTERN CHANGE THAT WE HAVE BEEN
ADVERTISING IN THE FORM OF A LONGWAVE TROUGH DEEPENING OVER THE
EAST THROUGH WEDNESDAY...WHICH IN TURN STALLS A COLD FRONT ACROSS
THE CAROLINAS DURING THIS TIME. THERE ARE MODEL DIFFERENCES WITH
REGARD TO THE RESULTANT SENSIBLE WEATHER IMPACTS...WITH THE GFS
MOVING SEVERAL LOW PRESSURE WAVES NORTHEAST ALONG THE FRONT AND
THE DEEPEST MOISTURE AND BEST CHANCE FOR RAIN ACROSS OUR NORTHERN
ZONES AND NORTHWARD...WHILE THE ECMWF KEEPS THE FRONT CLOSER TO
THE COAST AND DEEPER MOISTURE AND BEST CHANCE FOR RAIN ACROSS MOST
OF OUR CWA. GIVEN THE FAIR AMOUNT OF SPREAD AMONG BOTH THE GFS AND
ECMWF ENSEMBLE MEMBERS DURING THIS TIME...WILL HOLD OFF PROVIDING
FINE DETAILS...BUT RATHER HIGHLIGHT THE LIKELIHOOD FOR COOLER
NEAR-SEASONABLE TEMPS AND THE GOOD CHANCE FOR SHOWERS AND
THUNDERSTORMS EACH DAY. SINCE THE ENHANCED JET FEATURES AND
DYNAMICS ARE FORECAST BY THE MODELS TO REMAIN TO OUR NORTH AND
WEST... HAZARDS RELATED TO SHOWERS AND THUNDERSTORMS DURING THIS
TIME MAY BE MORE IN THE WAY OF FLASH FLOOD POTENTIAL RATHER THAN
WIND/HAIL POTENTIAL...BUT THIS CAN CHANGE TOO SO BE SURE TO CHECK
BACK.
FOR THE LATTER HALF OF THE WEEK...THE LONGWAVE TROUGH WILL BEGIN TO
LIFT NEWD WHILE LEAVING A WEAKNESS OVER THE OH AND MS RIVER
VALLEYS. MEANWHILE THE RIDGE OVER THE WESTERN ATLANTIC WILL BEGIN
TO BUILD WESTWARD...HELPING TO INCREASE SOUTHERLY FLOW AND
MOISTURE TRANSPORT ACROSS OUR AREA. AS SUCH...POTENTIALLY WET
CONDITIONS MAY CONTINUE RIGHT THROUGH THE END OF THE WEEK.
ALTHOUGH MONDAY MAY STILL SEE HIGHS IN THE LOW 90S JUST AHEAD OF THE
FRONT...FOR THE REST OF THE WEEK HIGH TEMPS WILL REMAIN SLIGHTLY
BELOW NORMAL (MID-UPPER 80) WHILE CLOUDS AND PRECIP WILL LIKELY KEEP
LOW TEMPS NEAR OR PERHAPS SLIGHTLY ABOVE NORMAL (AROUND 70).
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 240 PM FRIDAY...
OVERALL...VFR CONDITIONS ARE EXPECTED ACROSS CENTRAL NORTH
CAROLINA. WIDELY SCATTERED TO SCATTERED THUNDERSTORMS ARE POSSIBLE
THIS EVENING...AND THESE FIRST SHOULD OCCUR TO THE NORTH AND EAST
OF THE TRIANGLE...GRADUALLY SHIFTING SOUTH DURING THE EVENING
THROUGH MIDNIGHT. DIFFICULT TO NOTE THE TIMING OF THESE IN THE
TAFS...AND HAVE NOTED SOME VCSH IN THE FORECAST FOR KRDU...KRWI...
AND KFAY...ENDING LAST AT KFAY AROUND 04Z. IT IS POSSIBLE THAT
THERE WILL BE SOME LOCAL MVFR CONDITIONS IN LIGHT FOG OR HAZE LATE
TONIGHT...BUT AGAIN...THE CONFIDENCE IS TOO LOW TO INCORPORATE IN
THE 18Z VALID TAF.
VFR CONDITIONS OUTSIDE OF ANY ISOLATED OR WIDELY SCATTERED SHOWERS
AND THUNDERSTORMS...AND ANY LATE NIGHT OR MORNING LIGHT FOG OR
HAZE...CONTINUE SATURDAY AFTERNOON THROUGH SUNDAY. AS A COLD FRONT
APPROACHES CENTRAL NORTH CAROLINA MONDAY AND WEAKENS WHILE
LINGERING IN VICINITY OF THE AREA...A BETTER CHANCE OF ADVERSE
AVIATION CONDITIONS DEVELOPS. ANTICIPATE SCATTERED TO AT TIMES
NUMEROUS SHOWERS AND THUNDERSTORMS...AND PERIODS OF BELOW MVFR
CEILINGS AND VISIBILITIES AS A RESULT.
&&
.CLIMATE...
HIGH TEMPERATURE RECORDS AND YEAR RECORD LAST SET.
RALEIGH-DURHAM... GREENSBORO...
07/06 102 1999 100 1977
07/07 102 2010 101 1977
07/08 103 1977 102 1977
FAYETTEVILLE...
07/06 99 1990
07/07 103 2010
07/08 102 1977
IF WE REACH OR EXCEED 100 DEGREES AT THE RALEIGH-DURHAM AIRPORT EACH
DAY THROUGH SUNDAY...INCLUDING TODAY...WE WILL HAVE SET A NEW
RECORD FOR THE NUMBER OF CONSECUTIVE 100+ DEGREE DAYS (6 DAYS).
THE EXISTING RDU RECORD IS 5 DAYS...SET ON JULY 20-24 IN 2011. THE
HIGH WAS 94 AT KRDU THIS PAST MONDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NCZ008>011-
025>028-040>043-074>078-083>086-088-089.
HEAT ADVISORY FROM 11 AM TO 8 PM EDT SATURDAY FOR NCZ007>011-
024>028-040>043-073>078-083>086-088-089.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...DJF/NMP
LONG TERM...NMP
AVIATION...DJF
CLIMATE...RAH