Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/17/12
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
853 AM PDT SUN JUL 15 2012
.SYNOPSIS...
AN UPPER-LEVEL TROUGH STRENGTHENING ALONG THE WEST COAST...WILL
BRING STRONGER ONSHORE FLOW...GRADUAL INLAND DRYING...AND A DEEPER
MARINE LAYER THROUGH TUESDAY. IT WILL BE COOLER...WITH MARINE CLOUDS
EXTENDING FARTHER INTO THE VALLEYS EACH MORNING. LATER NEXT WEEK...
HIGH PRESSURE OVER THE MIDDLE OF THE COUNTRY WILL REBUILD
WESTWARD...BRINGING WARMER DAYS AND SOME INCREASE IN MONSOONAL
MOISTURE. THE ADDED MOISTURE WILL LIKELY RESULT IN SOME AFTERNOON
CLOUDS OVER THE MOUNTAINS...AND PERHAPS SOME RENEWED CHANCE OF
THUNDERSTORMS OVER THE WEEKEND OR EARLY NEXT WEEK.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
&&
VISIBLE SATELLITE IMAGERY EARLY THIS MORNING SHOWED EXTENSIVE MARINE
STRATUS OFFSHORE AND EXTENDING WELL INTO THE VALLEYS. BASED ON THE
12Z MIRAMAR SOUNDING...THE LAYER HAD DEEPENED TO AROUND 2000 FT AT
12Z AND WAS CAPPED BY A STRONG 10 DEGREE C INVERSION. SFC PRESSURE
GRADIENTS REMAINED WEAK...BUT WERE ONSHORE GENERALLY 2-4 MBS TO THE
DESERTS.
WATER VAPOR IMAGERY THROUGH 15Z SHOWS THE UPPER-LEVEL TROUGH ALONG
THE WEST COAST WAS IN FULL DEEPENING MODE WHICH WILL DEFINE OUR
WEATHER FOR THE NEXT SEVERAL DAYS. LOWER SFC PRESSURES OVER THE
INTERIOR...STRONGER ONSHORE FLOW...AND A DEEPENING MARINE LAYER WILL
BRING COOLER DAYS AND SOME NOCTURNAL CLOUDS/FOG WELL INTO THE
VALLEYS THROUGH TUE. INLAND...BETTER ONSHORE FLOW WILL BRING DRYING
WITH LOWER DEWPOINTS INTO THE DESERTS.
FOR TODAY...SOME RESIDUAL BOUNDARY LAYER MOISTURE WILL LIKELY RESULT
IN SOME CU BUILD-UPS OVER THE MOUNTAINS. AN ISOLATED SHOWER IS NOT
OUT OF THE QUESTION EITHER BASED ON AVBL SFC DEWPOINTS IN THE MTNS/
DESERTS AND THE HIGHER RESOLUTION HRRR MODEL. FOR NOW...THE POP
LOOKS TOO LOW FOR MENTION IN THE ZONES. ALONG THE COAST...THE STRONG
INVERSION MAY CONTRIBUTE TO A LATE BREAK-UP OF THE STRATUS...BUT THE
THICKNESS OF THE CLOUD DECK BASED ON SFC OBSERVATIONS SHOW IT SHOULD
BREAK...EVEN AT MOST BEACHES...WITH AT LEAST A FEW HOURS OF SUN
TODAY. ELSEWHERE... SUNNY...WITH TEMPS A FEW DEGREES LOWER THAN
YESTERDAY W OF THE MTNS...BUT A FEW DEGREES HIGHER IN THE LOWER
DESERTS DUE TO LOWER HUMIDITY.
WEDNESDAY SHOULD BE THE TRANSITION DAY WITH THE MARINE LAYER
BEGINNING TO DECREASE IN DEPTH AND SLOW INLAND WARMING AS THE TROUGH
OF LOW PRESSURE NEAR THE WEST COAST BEGINS TO WEAKEN AND HIGH
PRESSURE TO THE EAST BEGINS TO STRENGTHEN. FOR WED NIGHT/THU...SOME
MID/HIGH LEVEL MOISTURE FROM THE REMNANTS OF HURRICANE FABIO WILL BE
DRAWN NORTHWARD ACROSS CALIFORNIA...MAINLY NORTH OF ORANGE COUNTY.
FOR SOUTHWEST CALIFORNIA...THE MAIN IMPACT WOULD APPEAR TO BE SOME
INCREASE IN MID/HIGH LEVEL CLOUDS. CHANCES FOR SPRINKLES/SHWRS THIS
FAR SOUTH LOOK MINIMAL. THE HIGH CLOUDS MAY CONTRIBUTE TO A COLORFUL
SUNSET THOUGH...FOR THOSE AREAS UNOBSCURED BY LOWER MARINE CLOUDS.
WARMER INLAND FOR THE LATTER HALF OF THE WEEK AS HIGH PRESSURE
BROADENS ACROSS THE WESTERN HALF OF THE COUNTRY. THIS WILL TURN
UPPER-LEVEL WINDS AGAIN MORE SOUTHEASTERLY...SOME MONSOONAL MOISTURE
MAY INCREASE OVER SW CA...BRINGING PERIODS OF MID/HIGH CLOUDS AND
AFTERNOON CU OVER THE MOUNTAINS. POPS HAVE BEEN BUMPED UP OVER
CLIMATOLOGY TO REFLECT AN INCREASED CHANCE OF CONVECTIVE SHOWERS BUT
CONFIDENCE NOT HIGH ENOUGH TO INCLUDE IN THE CURRENT FORECAST. TEMPS
SHOULD BE NEAR MID-SUMMER AVERAGES.
&&
.AVIATION...
151545Z...COAST/VALLEYS...STRATUS WILL CLEAR MOST VALLEYS THROUGH
17Z AND COASTAL AREAS BETWEEN 16Z AND 18Z EXCEPT ALONG THE BEACHES
WHERE PATCHY BKN CLOUDS WILL LINGER THROUGH THE AFTERNOON. STRATUS
WILL RETURN TO COASTAL AIRPORTS BETWEEN 00Z AND 04Z AND THE VALLEYS
BETWEEN 05Z AND 09Z WITH LITTLE CHANGE TO BASES...1000-1500 FT MSL
AND TOPS TO 2000 FT MSL. LOCAL VIS BELOW 3 MI WILL OCCUR IN THE
VALLEYS LATE TONIGHT.
MTNS/DESERTS...SCATTERED CUMULUS WITH BASES 8000-9000 FT MSL ARE
EXPECTED OVER THE MTNS AND SOME DESERT AREAS THROUGH 02Z.
OTHERWISE...MOSTLY CLEAR WITH UNRESTRICTED VIS THROUGH MONDAY.
.MARINE...
HURRICANE FABIO...CURRENTLY IN OUR SWELL WINDOW NEAR 17N/117W WILL
BRING INCREASING SOUTH SWELL BY MONDAY NIGHT OR TUESDAY...GENERALLY
4 FEET IN THE COASTAL WATERS. THIS WILL BE A BIT HIGHER THAN WITH
THE LAST 2 HURRICANES DUE TO THE SLOWER MOVEMENT OF FABIO AND HENCE
A LONGER DURATION OF THE SWELL GENERATION...DESPITE FABIO BEING LESS
STRONG. THIS WILL BRING ANOTHER ROUND OF ABOVE NORMAL SURF AND RIP
CURRENTS ON MAINLY S/SW FACING BEACHES LATE MONDAY NIGHT THROUGH
WED...THEN GRADUALLY DIMINISHING THROUGH THU.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&
$$
PUBLIC...JAD
AVIATION/MARINE...MAXWELL
AREA FORECAST DISCUSSION...UPDATED
NWS RENO NV
905 PM PDT SAT JUL 14 2012
.UPDATE...
CONVECTION FINALLY GOT ENOUGH INSTABILITY TO BREAK THROUGH THE CAP
IN MINERAL COUNTY. WENT AHEAD AND PUT ISOLATED SHOWERS AND
THUNDERSTORMS BACK INTO THE FORECAST FOR MINERAL COUNTY, AS WE
COULD SEE A FEW STORMS MAINLY SOUTH AND EAST OF HAWTHORNE BEFORE
MIDNIGHT. HOON
&&
.PREVIOUS DISCUSSION... /ISSUED 454 PM PDT SAT JUL 14 2012/
UPDATE...
WENT AHEAD AND PULLED THE THUNDERSTORM CHANCES FOR THE REMAINDER
OF THIS AFTERNOON AND EVENING. CUMULUS BUILDUPS IN MONO- MINERAL
JUST DON`T HAVE ENOUGH MOISTURE/INSTABILITY TO REALLY GET GOING
TODAY. DRY AIRMASS HAS PUSHED THE BULK OF THE MOISTURE INTO
EASTERN NEVADA. ALL PUBLIC AND FIRE PRODUCTS HAVE BEEN UPDATED AND
SENT. WEB PRODUCTS WILL UPDATE SHORTLY.
AS FOR TOMORROW`S FORECAST, WITH THE DRYING THAT WE SAW TODAY,
TOMORROW IS LOOKING MUCH LESS PROBABLE FOR THUNDERSTORMS. POPS
WILL LIKELY BE TRIMMED BACK FOR SUNDAY, BUT WILL WAIT UNTIL THE
00Z MODEL RUNS TO COME IN BEFORE MAKING ANY BIG CHANGES TO SUNDAY.
HOON
PREVIOUS DISCUSSION... /ISSUED 201 PM PDT SAT JUL 14 2012/
SHORT TERM...
CURRENT WATER VAPOR IMAGERY DEPICTS A VERY DRY AIRMASS ALOFT THAT
HAS MOVED ACROSS WESTERN NEVADA OVERNIGHT AND THIS MORNING.
COMPARED TO YESTERDAY MORNING, THE 12Z OBSERVED PRECIPITABLE
WATER AT KRNO DROPPED 0.20 INCHES (TO 0.37 IN). WITH THE DEEPER
MOISTURE DISPLACED TO THE EAST, CONVECTION HAS BEEN A LOT SLOWER
TO DEVELOP THIS AFTERNOON. BASED ON THE LATEST HRRR FORECAST,
VISIBLE SATELLITE AND RADAR TRENDS, DECIDED TO TRIM BACK COVERAGE
OF THUNDERSTORMS FOR THIS AFTERNOON AND EVENING. THE BEST CHANCE
WILL BE ACROSS MINERAL, EASTERN MONO AND SOUTHEASTERN CHURCHILL
COUNTIES WHERE THE LATEST SPC MESOANALYSIS SHOWS MUCAPES OF AROUND
500 J/KG. WITH LITTLE IN THE WAY OF SHEAR, ANY STORMS THAT FORM
WILL BE PULSE STORMS THAT WILL SLOWLY DRIFT TO THE EAST-NORTHEAST.
ON SUNDAY, THE 12Z GFS/NAM/ECMWF ARE IN GOOD AGREEMENT THAT THE
AREA OF LOW PRESSURE OVER CENTRAL OREGON WILL LIFT TO THE
NORTHEAST WHILE A WEAK AREA OF LOW PRESSURE DEVELOPS NEAR THE
CENTRAL CALIFORNIA COAST. THIS WILL SET UP AN AREA OF DEFORMATION
ACROSS THE RENO CWA FROM TAHOE NORTHEAST TO WINNEMUCCA. SOUTH OF THIS
BOUNDARY, THE FLOW WILL TURN MORE SOUTHERLY, ALLOWING MONSOON
MOISTURE TO BUILD BACK ACROSS SOUTHEASTERN HALF OF THE CWA WITH
MODEL PWATS INCREASING TO NEAR 0.75 INCHES. THE EXISTING FORECAST
LOOKS GOOD WITH ISOLATED COVERAGE SOUTH OF I-80 AND SCATTERED
STORMS SOUTH OF US-50. THE STORMS ACROSS MINERAL AND MONO COUNTIES
WILL BE ON THE WET SIDE, WITH WET/DRY HYBRID STORMS CLOSER TO THE
MOISTURE BOUNDARY BETWEEN I-80 AND US-50 (SEE THE FIRE WEATHER
DISCUSSION BELOW FOR MORE DETAILS).
THE WEAKNESS NEAR THE CALIFORNIA COAST WILL WEAKEN ON MONDAY AS A
STRONGER AREA OF LOW PRESSURE BUILDS SOUTH ACROSS WESTERN
WASHINGTON AND OREGON. THIS WILL TURN THE UPPER LEVEL FLOW BACK TO
THE SOUTHWEST, USHERING IN DRIER AIR ACROSS THE RENO CWA. THE BEST
CHANCE FOR ANY CONVECTION WILL BE ACROSS MINERAL AND MONO
COUNTIES, CLOSER TO THE DEEPER MOISTURE.
THE AREA OF LOW PRESSURE WILL CONTINUE TO SLIDE SLOWLY SOUTH
ACROSS WESTERN OREGON ON TUESDAY. THIS WILL KEEP DRY SOUTHWEST
FLOW IN PLACE. DEPENDING ON THE PLACEMENT OF THE LOW, THERE IS A
VERY SMALL CHANCE THAT EXTREME NORTHERN LASSEN COUNTY AND THE
SURPRISE VALLEY COULD SEE A PASSING SHOWER ON TUESDAY AFTERNOON
SO A SLGT CHANCE WAS INTRODUCED WITH THIS PACKAGE FOR THOSE AREAS.
MYRICK
LONG TERM...WEDNESDAY THROUGH SATURDAY...
A TROUGH LOCATED OVER THE PACIFIC NORTHWEST WILL CREATE A DRY AND
STABLE SOUTHWEST FLOW ALOFT WEDNESDAY AND THURSDAY. NUMERICAL
GUIDANCE DIFFERS FOR FRIDAY AND SATURDAY...SOME SOLUTIONS BRING
THE TROUGH EASTWARD WHILE OTHER SOLUTIONS MOVE IT WESTWARD AND
BUILD THE RIDGE OVER THE EASTERN SIERRA AND WESTERN NEVADA. THE
OVERALL CONSENSUS IS FOR A DRY FORECAST WITH A WARMING TREND
THROUGH SATURDAY...WHICH IS ALREADY COVERED WELL BY THE ONGOING
FORECAST.
ONE WILD CARD IS THE SLIGHT CHANCE THAT MOISTURE FROM THE REMNANTS
OF HURRICANE FABIO COULD BE DRAWN NORTHWARD FRIDAY. TWO RECENT RUNS
OF THE GFS ARE THE ONLY ONES SHOWING THIS SOLUTION. WITH FABIO
CURRENTLY LOCATED 550 MILES SSW OF THE SOUTHERN TIP OF
BAJA-CALIFORNIA CONFIDENCE IS VERY LOW IN THIS SCENARIO. FOR NOW A
SLIGHT CHANCE OF THUNDERSTORMS WAS INTRODUCED FRIDAY FOR MONO
COUNTY. JCM
AVIATION...
VFR CONDITIONS WILL PREVAIL OVERALL THROUGH THE WEEKEND AND INTO
NEXT WEEK. THUNDERSTORMS ARE POSSIBLE SUNDAY AFTERNOON FROM I-80
SOUTHWARD. IN THE VICINITY OF THESE STORMS THE CIG/VSBYS SHOULD BE
AOA 5000/5 WITH GUSTY SFC WINDS.
FOR THE TERMINALS ISOLATED STORMS ARE POSSIBLE SUNDAY AFTERNOON AND
EARLY EVENING IN THE VICINITIES OF KTRK..KTVL AND KRNO...WITH
SOMEWHAT BETTER POTENTIAL FOR THUNDERSTORMS IN THE VICINITY OF KMMH.
JCM
FIRE WEATHER...
HAVE TRIMMED BACK THUNDERSTORM COVERAGE THIS AFTERNOON BASED ON
LATEST RADAR AND SATELLITE TRENDS TO ENCOMPASS EASTERN MONO COUNTY
INTO MINERAL AND EASTERN CHURCHILL COUNTIES. WITH PLENTY OF MID AND
UPPER LEVEL DRY AIR WORKING INTO THE REGION IT HAS SUPPRESSED
THUNDERSTORM DEVELOPMENT.
TYPICAL AFTERNOON ZEPHYR WINDS CAN BE EXPECTED WITH GUSTS OF 25 TO
30 MPH LATE THIS AFTERNOON AND INTO THE EARLY EVENING. THESE GUSTS
WILL CORRESPOND WITH HUMIDITY VALUES AROUND 10-15% WITH LOCALLY
CRITICAL CONDITIONS POSSIBLE. HOWEVER, THESE WILL NOT BE WIDESPREAD
ENOUGH TO WARRANT ANY RED FLAG WARNINGS TODAY. AFTERNOON WESTERLY
WINDS CAN BE EXPECTED AGAIN SUNDAY, BUT WILL BE ABOUT 5 MPH LESS IN
SPEED.
A PIECE OF ENERGY AND WEAK DEFORMATION BAND WILL HELP TO FOCUS
THUNDERSTORM DEVELOPMENT SUNDAY AFTERNOON WITH ISOLATED COVERAGE
POSSIBLE BETWEEN INTERSTATE 80 AND HIGHWAY 50 AND SCATTERED COVERAGE
SOUTH OF HIGHWAY 50. THE DEEPEST MOISTURE WILL BE SOUTH OF HIGHWAY
50 AND EAST OF HIGHWAY 95, SO STORMS THROUGH THIS AREA WILL BE WET.
NORTH AND WEST OF THERE, A HYBRID OF STORMS ARE POSSIBLE WITH THE
POTENTIAL FOR A DRY LIGHTNING STRIKE OUTSIDE OF THE WET THUNDERSTORM
CORE. THIS COULD START NEW FIRES, BUT WITH THE SMALL AREA OF HYBRID
STORMS, AM NOT PLANNING ANY RED FLAG WARNINGS AT THIS TIME. IN
ADDITION, WATCHING HOW THE DRY AIR WORKING INTO CALIFORNIA AND
WESTERN NEVADA HAS SQUELCHED THUNDERSTORM DEVELOPMENT TODAY, AM A
BIT CONCERNED THAT MODELS MAY BE OVERDOING THE CONVECTIVE POTENTIAL
SUNDAY AND COVERAGE MAY NEED TO BE TRIMMED A BIT. DF
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS TAUNTON MA
206 PM EDT SUN JUL 15 2012
.SYNOPSIS...
HOT AND HUMID WEATHER WILL CONTINUE TODAY WITH SCATTERED
THUNDERSTORMS...ESPECIALLY IN WESTERN NEW ENGLAND AS A WEAK COLD
FRONT APPROACHES THE REGION. HEAT AND HUMIDITY WILL BE WITH US
THROUGH WEDNESDAY...WHEN A STRONGER COLD FRONT MAY BRING ANOTHER
ROUND OF THUNDERSTORMS. HIGH PRESSURE WILL DOMINATE OUR WEATHER
THURSDAY INTO THE START OF NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
2 PM UPDATE...
SHOWERS/SCT TSTMS INCREASING IN COVERAGE ACROSS SE NY AND MOVING
EAST. ACTIVITY IS MOVING INTO A FAVORABLE ENVIRONMENT WITH MLCAPES
1000-1500 J/KG ACROSS SW NEW ENG SO EXPECT CONVECTION TO MOVE INTO
THE REGION NEXT 1-2 HOURS...AND HRRR INDICATING INCREASING
SHOWERS/ISOLD TSTMS 19-21Z. MID LEVEL LAPSE RATES AND DEEP LAYER
SHEAR ARE WEAK WHICH WILL LIMIT SEVERE WX POTENTIAL...BUT CANT
RULE OUT A STRONG STORM AND HEAVY RAINFALL WILL BE A CONCERN
GIVEN HIGH PWAT AIRMASS.
PREVIOUS DISCUSSION...
MID LEVEL TROF ACROSS GT LAKES WITH WV IMAGERY SHOWING MULTIPLE
SHORTWAVES MOVING THROUGH THE FLOW. MAIN IMPULSE ACROSS MI BUT
LEAD SHORTWAVE ACROSS W NY WILL BE LIFTING NE ACROSS CENTRAL NEW
ENG LATER THIS AFTERNOON WHICH SHOULD PROVIDE A TRIGGER FOR
CONVECTION TO DEVELOP.
THERE ARE A FEW SHOWERS ACROSS E NY WHICH MAY AFFECT PORTIONS OF W
NEW ENG EARLY THIS AFTERNOON...BUT MAIN FOCUS FOR STRONGER TSTMS
SHOULD BE MID TO LATE AFTERNOON ACROSS W ZONES AND EXTENDING INTO
THE EVENING FURTHER E AS DEEPER MOISTURE AND MID LEVEL OMEGA
APPROACHES FROM THE WEST. CAPES ARE FORECAST TO INCREASE TO
1000-2000 J/KG...BUT MID LEVEL LAPSE RATES ARE WEAK AND DEEP LAYER
SHEAR IS MARGINAL. STILL...IF FORECAST INSTABILITY CAN BE REALIZED
A FEW STRONG TO SEVERE STORMS WILL BE POSSIBLE GIVEN 0-6KM SHEAR
25-30 KT. PWATS INCREASE OVER 2" BY LATE TODAY SO ANY STORMS WILL
ALSO HAVE THE POTENTIAL TO PRODUCE VERY HEAVY RAINFALL. HIGHEST
POPS THIS AFTERNOON WILL BE FOCUSED ACROSS W ZONES WITH LOWEST
POPS E NEW ENG WHERE MOST OF THE DAY SHOULD REMAIN DRY.
MID/HIGH CLOUDS ARE ADVANCING ACROSS W NEW ENG AND SUNSHINE WILL
GRADUALLY FADE AS CLOUDS INCREASE FROM WEST TO EAST. TEMPS
ALREADY IN THE LOW/MID 80S ACROSS MUCH OF THE REGION. WARMEST
TEMPS WITH SOME LOWER 90S POSSIBLE WILL BE ACROSS INTERIOR E MA
AND SE NH WHERE MOST SUNSHINE...BUT INCREASING CLOUD COVER WILL
SLOW TEMP RISE ACROSS W NEW ENG. DEWPOINTS WILL BE CLIMBING TO 70+
DURING THE AFTERNOON SO VERY HUMID.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
KEPT LIKELY POPS EARLY TONIGHT ACROSS INTERIOR AS WE EXPECT
ACTIVITY TO SLOWLY DIMINISH WITH LOSS OF DAYTIME HEATING. 00Z GFS
IS MORE EMPHATIC THAT STRONGER SURFACE LOW WILL FORM ALONG FRONT
WHICH RESULTS IN MORE WIDESPREAD RAINFALL TONIGHT. NOT SURE THAT
WILL BE CASE GIVEN RATHER FLAT MID LEVEL TROUGH SO PREFER TO LEAN
MORE TOWARD DRIER NAM/SREF SOLUTION WHICH GIVES CHANCE POPS CLOSER
TO COAST. SHOULD SEE PARTIAL CLEARING AND DRIER AIR WORK ITS WAY
INTO REGION TOWARD DAYBREAK.
FRONT WILL SETTLE NEAR S COAST MON AND EVENTUALLY WASHES OUT.
ALTHOUGH CROSS SECTIONS SHOW DRYING THROUGH COLUMN...THERE MAY BE
ENOUGH LEFTOVER MOISTURE COMBINED WITH WEAK SURFACE CONVERGENCE TO
PRODUCE AN ISOLATED SHOWER OR THUNDERSTORM ALONG S COAST MON
AFTERNOON. NOT MUCH CHANGE IN AIRMASS BEHIND FRONT SO HIGHS SHOULD
ONCE AGAIN TOP OUT IN 80S AND LOWER 90S...ALTHOUGH HUMIDITY WILL
BE LOWER.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...SHORTWAVE RACES EAST OF THE AREA MONDAY...THEN A DEEPER
MID-LEVEL TROUGH APPROACHES FOR WEDNESDAY AND THURSDAY. A MID-
LEVEL RIDGE SHOULD BUILD OVER THE CENTRAL USA DURING THE LATTER
HALF OF NEXT WEEK. THIS WILL COMPLICATE OUR FORECAST AS THE
DOWNSTREAM MID-LEVEL TROUGH COULD ALSO AMPLIFY AND RETROGRADE BACK
OVER NEW ENGLAND IF IT DOES NOT REMAIN PROGRESSIVE.
SURFACE HIGH PRESSURE SITS OFFSHORE THROUGH THE EXTENDED PERIOD WITH
A SOUTHWEST FLOW INTO SOUTHERN NEW ENGLAND UNTIL WEDNESDAY. THIS
WILL MEAN HEAT AND HUMIDITY INTO MIDWEEK.
MONDAY NIGHT-TUESDAY...
SHORTWAVE MOVES OFF TO THE EAST MONDAY MORNING WITH BUILDING HEIGHTS
OVER NEW ENGLAND. MODELS CONTINUE TO SHOW SURFACE PRESSURE FIELDS
HINTING AT A LEE TROUGH ALONG THE NORTHEAST CORRIDOR. MODELS
CONTINUE TO INDICATE MARGINALLY FAVORABLE CONVECTIVE PARAMETERS
DURING THIS PERIOD. HOWEVER...THE SOUNDINGS LOOK TO BE TOO DRY
OVER TOO DEEP A LAYER TO REALLY SUPPORT SCATTERED TO WIDESPREAD
CONVECTION. HAVE KEPT THIS PORTION OF THE FORECAST DRY.
WEDNESDAY...
A COLD FRONT MOVES THROUGH AND PROVIDES A FOCUS FOR SCATTERED
SHOWERS/TSTMS.
THURSDAY-FRIDAY...
COLD FRONT MOVES OFFSHORE EARLY...WITH HIGH PRESSURE BUILDING
THROUGH THE PERIOD. THE CHANGE TO A NORTHWEST WIND WILL USHER IN
DRIER AIR.
SATURDAY...
HIGH PRESSURE CENTER BEGINS TO MOVE OFFSHORE BUT STILL LOOKS LIKE
IT WILL BE PREDOMINANT WEATHER FEATURE FOR OUR AREA. DRY FCST.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
OVERVIEW...MODERATE CONFIDENCE. SHOWERS/SCT TSTMS WILL MOVE EAST
ACROSS THE REGION LATE AFTERNOON THROUGH THIS EVENING AND WILL
LIKELY BE ACCOMPANIED BY A PERIOD OF MVFR/IFR CONDITIONS. AFTER
THE SHOWERS MOVE TO THE EAST OVERNIGHT...AREAS OF STRATUS AND FOG
WILL LIKELY DEVELOP THEN IMPROVING TO VFR DURING MON MORNING. LOW
PROB OF AN ISOLD SHOWER/TSTM DEVELOPING MON AFTERNOON.
KBOS TAF...MODERATE CONFIDENCE. EXPECT SHOWERS AND A FEW
TSTMS...MAINLY AFT 00Z WITH A PERIOD OF MVFR CONDITIONS
DEVELOPING. SHOWERS MOVE TO THE EAST AFTER MIDNIGHT...BUT AREAS OF
MVFR CIGS/VSBYS MAY DEVELOP...IMPROVING AFT 12Z. LOW PROB OF A
SEABREEZE MON AFTERNOON.
KBDL TAF...MODERATE CONFIDENCE. SHOWERS AND A FEW TSTMS EXPECTED
21-03Z WITH AREAS OF MVFR...THEN IMPROVING TO VFR OVERNIGHT.
OUTLOOK...TUESDAY THROUGH THURSDAY...
TUESDAY...MODERATE CONFIDENCE
PATCHY FOG/LOW CLOUDS DURING THE MORNING WITH IFR/LIFR
CONDITIONS. BEST CHANCE WILL BE IN THE CT VALLEY AND ALONG THE
SOUTH COAST.
WEDNESDAY...MODERATE CONFIDENCE
COLD FRONT APPROACHES DURING THE DAY. IFR/LIFR POSSIBLE IN
EARLY MORNING FOG/LOW CLOUDS...THEN VFR DURING THE DAY EXCEPT FOR
PASSAGE OF TSTMS. ANY SHOWERS/TSTMS THAT DEVELOP MAY BRING A PERIOD
OF MVFR/IFR MAINLY IN THE AFTERNOON/EVENING.
THURSDAY...MODERATE CONFIDENCE
HIGH PRESSURE BUILDS IN FROM THE NORTHWEST...VFR.
&&
.MARINE...
HIGH CONFIDENCE THROUGH MON WITH NO HEADLINES ANTICIPATED.
S/SW FLOW EXPECTED TODAY AHEAD OF WEAKENING COLD FRONT. SCATTERED
SHOWERS OR THUNDERSTORMS ARE POSSIBLE TOWARD EVENING...BEFORE
AREAS OF FOG DEVELOP IN MOIST AIRMASS. FRONT SHOULD WASH OUT
NEAR S COAST MON MORNING AND MAY BECOME FOCUS FOR AN ISOLATED
SHOWER OR THUNDERSTORM MON AFTERNOON AS FLOW REMAINS S/SW.
SEAS WILL SLOWLY BUILD ON S COASTAL WATERS THROUGH MON BUT SHOULD
NOT GET HIGHER THAN 4 FT S OF ISLANDS.
OUTLOOK...TUESDAY THROUGH THURSDAY
MODERATE CONFIDENCE DUE TO TIMING OF A COLD FRONT WEDNESDAY. THIS
WILL IMPACT THE STRENGTH OF THE SOUTHWEST FLOW.
SEAS SHOULD DIMINISH TUESDAY. INCREASING HUMIDITY IS EXPECTED
WITH DEW POINTS AROUND 70 MONDAY THROUGH WEDNESDAY. THIS COULD
MEAN AREAS OF FOG FOR THE LATE NIGHT AND EARLY MORNING PERIODS.
SEAS BUILD AGAIN TUESDAY NIGHT AND WEDNESDAY AHEAD OF AN APPROACHING
COLD FRONT...LOW RISK OF 5 FOOT SEAS ACROSS THE SOUTHERN OUTER
COASTAL WATERS. THIS FRONT IS EXPECTED TO BRING SCATTERED SHOWERS
AND THUNDERSTORMS WEDNESDAY INTO WEDNESDAY NIGHT. SEAS THEN SUBSIDE
SOMEWHAT FOR THURSDAY.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BELK/JWD
NEAR TERM...KJC
SHORT TERM...JWD
LONG TERM...BELK
AVIATION...BELK/KJC
MARINE...BELK/JWD
AREA FORECAST DISCUSSION...CORRECTED
NWS NEW YORK NY
519 AM EDT SUN JUL 15 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL APPROACH THE AREA TODAY AND MOVE ACROSS
TONIGHT. HOT AND HUMID CONDITIONS WILL THEN PERSIST THROUGH THE
MIDDLE OF THE WEEK WITH A BERMUDA HIGH PRESSURE SYSTEM DOMINATING
OUR WEATHER. A STRONGER COLD FRONT WILL MOVE ACROSS THE REGION ON
WEDNESDAY...FOLLOWED BY HIGH PRESSURE AND MORE SEASONABLE
CONDITIONS FOR THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLOUDS WILL INCREASE FROM W TO E THIS MORNING AS UPPER RIDGE AXIS
SLIDES E. TRICKY FORECAST TODAY IN REGARDS TO POPS BUT THINKING
THERE WILL BE TWO ROUNDS OF ACTIVITY. THE FIRST IS THIS MORNING
WITH A WEAK SHORTWAVE. HAVE YET TO SEE SHOWERS BEGIN
EXPANDING...BUT 00Z SPC WRF AND LATEST HRRR HIGH RES MODELS ARE IN
GOOD AGREEMENT THAT SHOWERS SHOULD START BECOMING MORE NUMEROUS
BETWEEN 09Z AND 12Z IN NJ AND PA AND TRACK INTO NE NJ. EASTERN
SECTIONS PROBABLY WON`T SEE MUCH OF ANYTHING THIS MORNING AND MUCH
OF THE DAY MAY EVEN BE DRY. MAY HAVE GONE OVERBOARD WITH POPS THIS
MORNING AND MAY NEED TO DECREASE THEM. SOUNDINGS ARE INDICATING
ELEVATED INSTABILITY IS PRESENT SO HAVE KEPT THE MENTION OF
THUNDER.
THERE IS UNCERTAINTY WITH HOW THE AFTERNOON PLAYS OUT. BOTH NAM
AND GFS ARE INDICATING NVA OVER THE AREA WITH THE SECOND SHORTWAVE
MOVING ACROSS TONIGHT. HOWEVER WEAK SFC TROUGH ACROSS WESTERN
ZONES SHOULD BE ENOUGH TO TRIGGER SCT SHOWERS/TSTMS ACROSS WESTERN
PORTIONS OF THE AREA. PWATS INCREASE TO 2+ INCHES THIS AFTERNOON
WITH INCREASING THETA E AND TALL SKINNY CAPE PROFILES WHICH ARE
FAVORABLE FOR HEAVY RAIN. NAM IS NOW KEEPING STRONGER SHEAR TO
THE WEST...WHILE GFS INCREASES IT TO 25-30 KT THIS AFTN AND EVE.
THEREFORE THERE IS A CHANCE THAT THE MID LEVEL FLOW COULD BE
STRONG ENOUGH TO PRODUCE A FEW STRONG STORMS. HOWEVER...EXPECT
THE MAIN THREAT TO BE URBAN AND SMALL STREAM FLOODING. SEE HYDRO
SECTION BELOW FOR MORE DETAILS.
HIGHS ARE EXPECTED TO RANGE BETWEEN MID AND UPPER 80S...BUT WILL
ALSO DEPEND ON THICKNESS OF CLOUD COVER AND ANY PRECIP THIS
MORNING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
WEAK COLD FRONT AND UPPER SHORTWAVE MOVE ACROSS TONIGHT WITH
DECREASING ATMOSPHERIC MOISTURE LEVELS AND THEREFORE DECREASING
THE HEAVY RAIN THREAT. HIGHEST POPS ARE CONFINED TO THIS TIME
PERIOD WHEN THERE WILL BE BETTER SYNOPTIC FORCING PRESENT. FRONT
SHOULD BE S OF THE AREA BY 12Z. MUCH MORE SUN EXPECTED ON MON
WITH RISING HEIGHTS AND H85 TEMPS AROUND 17-18C. THIS TRANSLATES
TO HIGHS IN THE LOWER TO MID 90S...SLIGHTLY COOLER AT THE
IMMEDIATE COAST. SW FLOW COURTESY OF BERMUDA HIGH OVER THE
ATLANTIC WILL ALSO KEEP IT MUGGY WITH DEWPOINTS GENERALLY AROUND
THE 70 DEGREE MARK. THIS WILL RESULT IN HEAT INDICES IN THE MID TO
UPPER 90S FOR MUCH OF THE AREA. NYC WILL LIKELY NEED A HEAT ADVSY
FOR MON...BUT ITS STILL A THIRD PERIOD EVENT SO WILL HOLD OFF.
DESPITE A THERMAL TROUGH ACROSS THE AREA ON MONDAY...WARM MID
LEVELS WILL KEEP A LID ON ANY SHOWER/TSTM ACTIVITY.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
A WARM RIDGE ALOFT WILL ENCAPSULATE MUCH OF THE COUNTRY EAST OF THE
ROCKIES THROUGH THE MIDDLE OF NEXT WEEK...WHILE A POLAR VORTEX OVER
HUDSON BAY IN CANADA DESCENDS SE AND CARVES OUT A STRONG UPPER TROF
ACROSS EASTERN CANADA AND THE NORTHEAST MID TO LATE WEEK. THE LATTER
OF WHICH WILL ALSO SEND A STRONG COLD FRONT THROUGH THE REGION ON
WED AFT/EVE. PRIOR TO THAT TIME...HOT...MUGGY WEATHER WILL BE ON
TAP FOR MON-WED.
GLOBAL MODELS ARE IN GOOD AGREEMENT WITH THE MASS FIELDS AND KEEP
THE AREA DRY MON AND TUE AHEAD OF THE MID WEEK COLD FRONT. MODEL
UPPER AIR SOUNDINGS SHOW STRONG MID LEVEL CAPPING WITH A DRY MIXED
LAYER.
IT WILL BE HOT AND HUMID TUE-WED WITH HIGHS GENERALLY IN THE MID
TO UPPER 90S FOR TUE. EXPECT COOLER CONDITIONS ALONG THE IMMEDIATE
COAST. OVERNIGHT LOWS WILL MAINLY BE IN THE 70S. THE TRICKY PART
OF THE FORECAST COMES WITH HEAT INDEX VALUES....WITH MID 90S TO
AROUND 100 FOR TUE AND WED. MODELS...IN PARTICULAR...THE GFS AND
NAM...DIFFER IN HOW MUCH MIXING THERE IS IN THE BOUNDARY LAYER.
THIS TYPICALLY RESULTS IN DEW POINTS SEVERAL DEGREES COOLER IN THE
NAM...WITH THE GFS NOTORIOUSLY HIGHER AND POOR AT MIXING DRIER AIR
TO THE SURFACE. A COMPROMISE OF THE GUIDANCE WAS USED HERE. HEAT
ADVISORIES WILL LIKELY BE REQUIRED FOR PORTIONS OF THE AREA...IN
PARTICULAR NYC METRO.
A STRONG COLD FRONT IMPACTS THE AREA WED AFT/EVE WITH ANOTHER GOOD
CHANCE FOR CONVECTION. MODERATE TO HIGH INSTABILITY AND WEAK SHEAR
WILL LIKELY PRODUCE ISOLATED STRONG TO SEVERE CONVECTION.
DRIER...MORE SEASONABLE CONDITIONS RETURN FOR THU-SAT AS STRONG
CANADIAN HIGH PRESSURE BUILDS SE FROM THE GREAT LAKES.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
WEAK HIGH PRESSURE AND A WEAK TROUGH OF LOW PRESSURE REMAIN IN
THE VICINITY TODAY. A WEAK COLD FRONT PASSES THROUGH TONIGHT.
SHOULD BE VFR MOST OF THE DAY...BUT CIGS 2000-3000 FT POSSIBLE
WITH MORNING SHOWERS. THESE SHOWERS HAVE NOT YET FORMED...BUT
SCATTERED COVERAGE IS ANTICIPATED TO DEVELOP AND BE IN THE
VICINITY BY AROUND 12Z. NOT ENOUGH CONFIDENCE TO GO WITH TSTMS IN
THE MORNING. ANOTHER ROUND OF SHOWERS WITH A BETTER CHANCE OF
EMBEDDED TSTMS IS ANTICIPATED LATE THIS AFTERNOON INTO THE
EVENING AHEAD OF AN APPROACHING WEAK COLD FRONT. LOCAL MVFR TO IFR
CONDITIONS POSSIBLE DURING THIS TIME. SHOWERS/TSTMS STILL POSSIBLE
AT ANY POINT THIS AFTERNOON...HOWEVER...NOT ENOUGH CONFIDENCE IN
GOING WITH A PREVAILING MENTION OF EITHER BEFORE THE TIMING OF THE
PROB30 GROUPS.
OUTLOOK FOR 06Z MON THROUGH THU...
.SUN NIGHT...CONTINUED CHANCE OF MVFR/IFR CONDITIONS IN
ANY SHOWERS/TSTMS.
.MON-TUE...VFR.
.WED...SCT AFTERNOON SHOWERS/TSTMS.
.THU...VFR.
&&
.MARINE...
MAINLY SW TO WSW FLOW 10-15 KT ACROSS THE OPEN OCEAN WATERS...AND
5-10 KT ELSEWHERE THROUGH WEDNESDAY. OCCASIONAL GUSTS JUST
BELOW 25 KT ARE POSSIBLE IN THE NY BIGHT REGION AND NEAR SHORE THIS
AFTERNOON INTO THIS EVENING. WAVEWATCH SEAS APPEAR A LITTLE OVERDONE
LATE THIS AFTERNOON INTO TONIGHT. AS A RESULT HAVE CAPPED OCEAN SEAS
AT 4 FT THROUGH TONIGHT. SEAS THEREAFTER PRIMARILY 2 TO 4 FT.
THUNDERSTORMS WILL BE POSSIBLE MAINLY LATE THIS AFTERNOON AND
TONIGHT...AND ONCE AGAIN WEDNESDAY AFTERNOON AND NIGHT AS A COLD
FRONT APPROACHES AND PASSES THROUGH. WINDS SHIFT NORTHERLY BEHIND
THE FRONT ON THURSDAY WITH PERHAPS A WEAK ONSHORE FLOW DEVELOPING
LOCALLY DURING THE AFTERNOON.
&&
.HYDROLOGY...
WHILE BASIN AVG QPF THROUGH TONIGHT RUNS
FROM AROUND 1/3 TO 3/4 INCH...HIGHEST NW OF NYC AND LOWEST OVER
ERN CT/LONG ISLAND...LOCALLY HEAVY RAINFALL OF 1-2 INCHES OR MORE
IS POSSIBLE UNDER ANY STRONGER CONVECTION GIVEN THE FORECAST NEAR-
TROPICAL NATURE OF THE ATMOSPHERE...AS CONVECTION WILL BE VERY
EFFICIENT IN CONVERTING AVAILABLE MOISTURE TO RAINFALL.
THERE IS FAIRLY HIGH POTENTIAL FOR MINOR URBAN/POOR DRAINAGE/SMALL
STREAM FLOODING. LOCALIZED FLASH FLOODING CANNOT BE RULED
OUT...ESPECIALLY IN AREAS THAT EXPERIENCE MULTIPLE ROUNDS OF HEAVY
RAIN...BUT THE FLASH FLOOD THREAT PROBABILITY/COVERAGE BOTH APPEAR
TOO SMALL TO WARRANT A FLASH FLOOD WATCH.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NEW YORK NY
443 AM EDT SUN JUL 15 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL APPROACH THE AREA TODAY AND MOVE ACROSS
TONIGHT. HOT AND HUMID CONDITIONS WILL THEN PERSIST THROUGH THE
MIDDLE OF THE WEEK WITH A BERMUDA HIGH PRESSURE SYSTEM DOMINATING
OUR WEATHER. A STRONGER COLD FRONT WILL MOVE ACROSS THE REGION ON
WEDNESDAY...FOLLOWED BY HIGH PRESSURE AND MORE SEASONABLE
CONDITIONS FOR THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
TRICKY FORECAST TODAY IN REGARDS TO POPS BUT THINKING THERE WILL
BE TWO ROUNDS OF ACTIVITY. THE FIRST IS THIS MORNING WITH A WEAK
SHORTWAVE. HAVE YET TO SEE SHOWERS BEGIN EXPANDING...BUT 00Z SPC
WRF AND LATEST HRRR HIGH RES MODELS ARE IN GOOD AGREEMENT THAT
SHOWERS SHOULD START BECOMING MORE NUMEROUS BETWEEN 09Z AND 12Z
IN NJ AND PA AND TRACK INTO NE NJ. EASTERN SECTIONS PROBABLY WON`T
SEE MUCH OF ANYTHING THIS MORNING AND MUCH OF THE DAY MAY EVEN BE
DRY. MAY HAVE GONE OVERBOARD WITH POPS THIS MORNING AND MAY NEED
TO DECREASE THEM. SOUNDINGS ARE INDICATING ELEVATED INSTABILITY IS
PRESENT SO HAVE KEPT THE MENTION OF THUNDER.
THERE IS UNCERTAINTY WITH HOW THE AFTERNOON PLAYS OUT. BOTH NAM
AND GFS ARE INDICATING NVA OVER THE AREA WITH THE SECOND SHORTWAVE
MOVING ACROSS TONIGHT. HOWEVER WEAK SFC TROUGH ACROSS WESTERN
ZONES SHOULD BE ENOUGH TO TRIGGER SCT SHOWERS/TSTMS ACROSS WESTERN
PORTIONS OF THE AREA. PWATS INCREASE TO 2+ INCHES THIS AFTERNOON
WITH INCREASING THETA E AND TALL SKINNY CAPE PROFILES WHICH ARE
FAVORABLE FOR HEAVY RAIN. THEREFORE...EXPECT THE MAIN THREAT TO BE
URBAN AND SMALL STREAM FLOODING. SEE HYDRO SECTION BELOW FOR MORE
DETAILS. NAM IS NOW KEEPING STRONGER SHEAR TO THE WEST...WHILE GFS
INCREASES IT TO 25-30 KT THIS AFTN AND EVE. THEREFORE IS A CHANCE
THAT THE MID LEVEL FLOW COULD BE STRONG ENOUGH TO PRODUCE A FEW
STRONG STORMS.
CLOUDS WILL INCREASE FROM W TO E THIS MORNING AS UPPER RIDGE AXIS
SLIDES E. HIGHS ARE EXPECTED TO RANGE BETWEEN MID AND UPPER
80S...BUT WILL ALSO DEPEND ON THICKNESS OF CLOUD COVER AND ANY
PRECIP THIS MORNING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
WEAK COLD FRONT AND UPPER SHORTWAVE MOVE ACROSS TONIGHT WITH
DECREASING ATMOSPHERIC MOISTURE LEVELS AND THEREFORE DECREASING
THE HEAVY RAIN THREAT. HIGHEST POPS ARE CONFINED TO THIS TIME
PERIOD WHEN THERE WILL BE BETTER SYNOTIC FORCING PRESENT. FRONT
SHOULD BE S OF THE AREA BY 12Z. MUCH MORE SUN EXPECTED ON MON
WITH RISING HEIGHTS AND H85 TEMPS AROUND 17-18C. THIS TRANSLATES
TO HIGHS IN THE LOWER TO MID 90S...SLIGHTLY COOLER AT THE
IMMEDIATE COAST. SW FLOW COURTESY OF BERMUDA HIGH OVER THE
ATLANTIC WILL ALSO KEEP IT MUGGY WITH DEWPOINTS GENERALLY AROUND
THE 70 DEGREE MARK. THIS WILL RESULT IN HEAT INDICES IN THE MID TO
UPPER 90S FOR MUCH OF THE AREA. NYC WILL LIKELY NEED A HEAT ADVSY
FOR MON...BUT ITS STILL A THIRD PERIOD EVENT SO WILL HOLD OFF.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
A WARM RIDGE ALOFT WILL ENCAPSULATE MUCH OF THE COUNTRY EAST OF THE
ROCKIES THROUGH THE MIDDLE OF NEXT WEEK...WHILE A POLAR VORTEX OVER
HUDSON BAY IN CANADA DESCENDS SE AND CARVES OUT A STRONG UPPER TROF
ACROSS EASTERN CANADA AND THE NORTHEAST MID TO LATE WEEK. THE LATTER
OF WHICH WILL ALSO SEND A STRONG COLD FRONT THROUGH THE REGION ON
WED AFT/EVE. PRIOR TO THAT TIME...HOT...MUGGY WEATHER WILL BE ON
TAP FOR MON-WED.
GLOBAL MODELS ARE IN GOOD AGREEMENT WITH THE MASS FIELDS AND KEEP
THE AREA DRY MON AND TUE AHEAD OF THE MID WEEK COLD FRONT. MODEL
UPPER AIR SOUNDINGS SHOW STRONG MID LEVEL CAPPING WITH A DRY MIXED
LAYER.
IT WILL BE HOT AND HUMID TUE-WED WITH HIGHS GENERALLY IN THE MID
TO UPPER 90S FOR TUE. EXPECT COOLER CONDITIONS ALONG THE IMMEDIATE
COAST. OVERNIGHT LOWS WILL MAINLY BE IN THE 70S. THE TRICKY PART
OF THE FORECAST COMES WITH HEAT INDEX VALUES....WITH MID 90S TO
AROUND 100 FOR TUE AND WED. MODELS...IN PARTICULAR...THE GFS AND
NAM...DIFFER IN HOW MUCH MIXING THERE IS IN THE BOUNDARY LAYER.
THIS TYPICALLY RESULTS IN DEW POINTS SEVERAL DEGREES COOLER IN THE
NAM...WITH THE GFS NOTORIOUSLY HIGHER AND POOR AT MIXING DRIER AIR
TO THE SURFACE. A COMPROMISE OF THE GUIDANCE WAS USED HERE. HEAT
ADVISORIES WILL LIKELY BE REQUIRED FOR PORTIONS OF THE AREA...IN
PARTICULAR NYC METRO.
A STRONG COLD FRONT IMPACTS THE AREA WED AFT/EVE WITH ANOTHER GOOD
CHANCE FOR CONVECTION. MODERATE TO HIGH INSTABILITY AND WEAK SHEAR
WILL LIKELY PRODUCE ISOLATED STRONG TO SEVERE CONVECTION.
DRIER...MORE SEASONABLE CONDITIONS RETURN FOR THU-SAT AS STRONG
CANADIAN HIGH PRESSURE BUILDS SE FROM THE GREAT LAKES.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
WEAK HIGH PRESSURE AND A WEAK TROUGH OF LOW PRESSURE REMAIN IN
THE VICINITY TODAY. A WEAK COLD FRONT PASSES THROUGH TONIGHT.
SHOULD BE VFR MOST OF THE DAY...BUT CIGS 2000-3000 FT POSSIBLE
WITH MORNING SHOWERS. THESE SHOWERS HAVE NOT YET FORMED...BUT
SCATTERED COVERAGE IS ANTICIPATED TO DEVELOP AND BE IN THE
VICINITY BY AROUND 12Z. NOT ENOUGH CONFIDENCE TO GO WITH TSTMS IN
THE MORNING. ANOTHER ROUND OF SHOWERS WITH A BETTER CHANCE OF
EMBEDDED TSTMS IS ANTICIPATED LATE THIS AFTERNOON INTO THE
EVENING AHEAD OF AN APPROACHING WEAK COLD FRONT. LOCAL MVFR TO IFR
CONDITIONS POSSIBLE DURING THIS TIME. SHOWERS/TSTMS STILL POSSIBLE
AT ANY POINT THIS AFTERNOON...HOWEVER...NOT ENOUGH CONFIDENCE IN
GOING WITH A PREVAILING MENTION OF EITHER BEFORE THE TIMING OF THE
PROB30 GROUPS.
OUTLOOK FOR 06Z MON THROUGH THU...
.SUN NIGHT...CONTINUED CHANCE OF MVFR/IFR CONDITIONS IN
ANY SHOWERS/TSTMS.
.MON-TUE...VFR.
.WED...SCT AFTERNOON SHOWERS/TSTMS.
.THU...VFR.
&&
.MARINE...
MAINLY SW TO WSW FLOW 10-15 KT ACROSS THE OPEN OCEAN WATERS...AND
5-10 KT ELSEWHERE THROUGH WEDNESDAY. OCCASIONAL GUSTS JUST
BELOW 25 KT ARE POSSIBLE IN THE NY BIGHT REGION AND NEAR SHORE THIS
AFTERNOON INTO THIS EVENING. WAVEWATCH SEAS APPEAR A LITTLE OVERDONE
LATE THIS AFTERNOON INTO TONIGHT. AS A RESULT HAVE CAPPED OCEAN SEAS
AT 4 FT THROUGH TONIGHT. SEAS THEREAFTER PRIMARILY 2 TO 4 FT.
THUNDERSTORMS WILL BE POSSIBLE MAINLY LATE THIS AFTERNOON AND
TONIGHT...AND ONCE AGAIN WEDNESDAY AFTERNOON AND NIGHT AS A COLD
FRONT APPROACHES AND PASSES THROUGH. WINDS SHIFT NORTHERLY BEHIND
THE FRONT ON THURSDAY WITH PERHAPS A WEAK ONSHORE FLOW DEVELOPING
LOCALLY DURING THE AFTERNOON.
&&
.HYDROLOGY...
WHILE BASIN AVG QPF FROM LATE TONIGHT THROUGH SUNDAY NIGHT RUNS
FROM AROUND 1/3 TO 3/4 INCH...HIGHEST NW OF NYC AND LOWEST OVER
ERN CT/LONG ISLAND...LOCALLY HEAVY RAINFALL OF 1-2 INCHES OR MORE
IS POSSIBLE UNDER ANY STRONGER CONVECTION GIVEN THE FORECAST NEAR-
TROPICAL NATURE OF THE ATMOSPHERE...AS CONVECTION WILL BE VERY
EFFICIENT IN CONVERTING AVAILABLE MOISTURE TO RAINFALL.
THERE IS FAIRLY HIGH POTENTIAL FOR MINOR URBAN/POOR DRAINAGE/SMALL
STREAM FLOODING. LOCALIZED FLASH FLOODING CANNOT BE RULED
OUT...ESPECIALLY IN AREAS THAT EXPERIENCE MULTIPLE ROUNDS OF HEAVY
RAIN...BUT THE FLASH FLOOD THREAT PROBABILITY/COVERAGE BOTH APPEAR
TOO SMALL TO WARRANT A FLASH FLOOD WATCH.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBANY NY
215 AM EDT SUN JUL 15 2012
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE IN THE OHIO VALLEY AND GREAT LAKES WILL
BRING A CHANCE OF BENEFICIAL SHOWERS AND POSSIBLY THUNDERSTORMS
TODAY. HIGH PRESSURE WILL BUILD FROM THE OHIO VALLEY MONDAY AND
TUESDAY WITH MAINLY SUNNY HOT CONDITIONS.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 130 AM...REGIONAL RADARS INDICATED CONVECTION IN PA WILL
LIKELY REMAIN OUT OF OUR REGION THROUGH ABOUT 12Z. THEREFORE WENT
AHEAD AND REMOVED POPS UNTIL THEN. IT SHOULD BE NOTED THAT THE
LATEST HRRR EXPERIMENTAL MODEL DID BRING A CLUSTER OF SHOWERS INTO
THE SCHOHARIE VALLEY AT 10Z...BUT THEN DISSIPATED THEM RIGHT AFTER
THAT. NOT BUYING INTO THIS SOLUTION.
SOME HIGH CLOUDINESS OVER THE REGION AND WAS GENERALLY THICKENING.
MANY SPOTS STILL REPORTING A BREEZE AROUND 5 MPH OR SO. DECIDED TO
RAISE TEMPS 1-3 DEGS IN A FEW SPOTS OVERNIGHT.
UPSTREAM CLOUDS WERE THICKENING EVEN MORE ACROSS THE GREAT LAKES
WHERE A PRETTY POTENT SHORT WAVE WAS. THIS WILL BE THE SYSTEM TO
AFFECT OUR REGION LATER TODAY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
RELATIVELY WELL DEFINED UPPER IMPULSE PREDICTED BY GUIDANCE AND
ENSEMBLES TO TRACK THROUGH THE REGION SUNDAY. WHILE CONVECTION HAS
DIMINISHED FROM EARLIER...A LOT OF MID LEVEL CLOUDS INDICATED LOTS
OF DEEP LAYER MOISTURE. THERE SHOULD BE MORE CLOUDS THAN SUN SUNDAY
WITH LIKELY SHOWERS AND THUNDERSTORMS BY MIDDAY. DID TEMPER THE POPS
BACK A LITTLE DURING THE MORNING.
LOW LEVEL JET ENERGY IS RELATIVELY WEAK...AND THERE SHOULD BE VERY
LITTLE THERMAL FORCING...SO CONVECTION SHOULD BE MOSTLY HEAVY
RAINERS...ALTHOUGH WITH THE INSTABILITY IN PLACE...AND SOME BREAKS
IN THE CLOUDS...ALONG WITH HIGHS IN THE 80S IN MOST AREAS...SOME
VERY ISOLATED STRONG WINDS AND HAIL ARE POSSIBLE. ANY AREAS THAT
COULD SEE A PROLONGED PERIOD OF SUN COULD SEE HIGHS AROUND 90...BUT
THAT LOOKS INCREASINGLY UNLIKELY THAT TEMPS WOULD GET THAT HIGH.
GUIDANCE SUGGESTS THE UPPER SYSTEM IS PREDICTED TO EXIT THE REGION
SUNDAY NIGHT INTO MONDAY...BUT STAY TUNED AS GUIDANCE OFTEN DOES
NOT TIME THE MOVEMENT OF CONVECTIVELY BASED SYSTEMS WELL. THE
WARM AND HUMID AIRMASS SHOULD STILL BE OVER THE REGION...BUT NO
ORGANIZED LOW LEVEL FOCUS OTHER THAN OLD OUFLOW BOUNDARIES.
SO...GRADUAL CLEARING...AND MAYBE SOME FOG SUNDAY NIGHT...THEN
CONTINUED DECREASING CLOUDS MONDAY... WITH JUST VERY ISOLATED
THUNDERSTORMS POSSIBLE...NOT ENOUGH TO ACKNOWLEDGE IN FORECAST
YET. HIGHS IN THE 80S TO MID 90S. ANOTHER WARM AND HUMID NIGHT
MONDAY NIGHT WITH LOWS IN THE 60S TO NEAR 70.
SOME SLIGHT WARMING OF THE BOUNDARY LAYER WELL AHEAD OF THE NEXT
APPROACHING SYSTEM. LOW LEVEL JET ENERGY GRADUALLY INCREASES...
ESPECIALLY IN NORTHERN AREAS BY LATER TUESDAY AFTERNOON. SOME
ISOLATED THUNDERSTORMS ARE POSSIBLE...ESPECIALLY IN AREAS OF
TERRAIN. HIGHS AGAIN WELL INTO THE 80S TO LOWER 90S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HAVE GENERALLY POPULATED THIS PORTION OF GRIDDED DATABASE WITH A
50/50 BLEND OF 18Z HPC MOS...AND 12Z/GMOS.
TUE NT-WED NT...BROAD UPPER LEVEL TROUGH IS EXPECTED TO DEVELOP
ACROSS EAST CENTRAL CANADA EXTENDING INTO THE EASTERN GREAT
LAKES...WITH AN ATTENDANT SFC COLD FRONT APPROACHING FROM THE GREAT
LAKES DURING THIS PERIOD. THERE ARE SOME TIMING DIFFERENCES IN SFC
FROPA ACROSS THE REGION...WITH THE 12Z/GFS SLIGHTLY
FASTER...OCCURRING MIDDAY TUESDAY FROM ALBANY N AND W...AND THE
AFTERNOON TO THE S/E...AND THE 12Z/ECMWF A BIT SLOWER...GEN RALLY
DURING THE AFTERNOON/EVENING HOURS. WILL INDICATE CHC POPS FOR MUCH
OF THE DAY...ALTHOUGH WILL TAPER ACROSS NW AREAS LATER IN THE DAY
WITH EXPECTATION FOR MAIN FROPA TO OCCUR EARLIER. FOR WED NT...WILL
KEEP SOME POPS THROUGH THE EVENING HOURS FOR AREAS S/E OF
ALBANY...TO ACCOUNT FOR POSSIBILITY OF SLIGHTLY SLOWER FROPA.
OTHERWISE...EXPECT A VERY WARM/HUMID NIGHT TUE NT/EARLY WED
AM...WITH MINS ONLY FALLING INTO THE UPPER 60S TO LOWER 70S ACROSS
MUCH OF THE HUDSON RIVER VALLEY AND MOHAWK RIVER VALLEY...WITH
LOWER/MID 60S ELSEWHERE. ON WED...GENERALLY EXPECT MAXES TO REACH
85-90 IN THE HUDSON RIVER VALLEY FROM ALBANY SOUTH...AND 80-85
NORTH...WITH GENERALLY UPPER 70S TO MID 80S ELSEWHERE. SOME AREAS
COULD BE WARMER FROM ALBANY S AND E SHOULD MORE SUNSHINE OCCUR WED
AM THAN CURRENTLY EXPECTED. BY WED NT/THU AM...EXPECT SOMEWHAT
COOLER/LESS HUMID CONDITIONS TO FILTER INTO THE REGION...WITH MINS
FALLING TO 60-65 WITHIN THE HUDSON RIVER VALLEY/MOHAWK RIVER
VALLEYS...AND 55-60 ELSEWHERE...ALTHOUGH SOME LOWER 50S WILL BE
POSSIBLE WITHIN PORTIONS OF THE SOUTHERN ADIRONDACKS.
THU-SAT...EXPECT DRY CONDITIONS...AS A SFC HIGH SLOWLY BUILDS INTO
THE REGION FROM THE GREAT LAKES. TEMPS MAY EVEN BE A BIT BELOW
SEASONAL LEVELS THU-FRI...GIVEN POTENTIAL 850 TEMPS FALLING INTO THE
+8 TO +10C RANGE...BEFORE WARMING TO NEAR OR ABOVE NORMAL BY
FRI-SAT. THIS TRANSLATES INTO MAX TEMPS IN THE UPPER 70S/LOWER 80S
IN VALLEYS THU...AND LOWER/MID 80S FRI-SAT...WITH OVERNIGHT MINS
FALLING INTO THE 50S IN MOST AREAS...WITH SOME 40S POSSIBLE ACROSS
PORTIONS OF THE SOUTHERN ADIRONDACKS/NORTH COUNTRY FRI AM.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
MAINLY VFR CONDITIONS ARE EXPECTED AT THE KALB/KGFL/KPOU/KPSF TAF
SITES UNTIL AN UPPER LEVEL DISTURBANCE BEGIN TO IMPACT THE REGION
BEGINING AROUND NOON SUNDAY AND CONTINUING INTO SUNDAY EVENING.
THERE COULD BE SOME MVFR FOG AT DURING THE REST OF TONIGHT AT KGFL
AND KPSF AND TEMPO GROUPS HAVE BEEN INCLUDED AT THESE LOCATIONS TO
ACCOUNT FOR THAT POSSIBLITY.
AS THE UPPER LEVEL TROF APPROACHES...SCATTERED TO NUMEROUS SHOWERS
AND THUNDERSTORMS WILL SPREAD ACROSS THE REGION OCCASIONAL
REDUCTIONS INTO THE MVFR RANGE IS LIKELY AT ALL THE TAF SITES...AND
IFR CONDITIONS ARE NOT OUT OF THE QUESTION...BUT FOR NOW HAVE NOT
BEEN INCLUDED IN THE FORECAST.
HAVE INCLUDED VCTS FOR ALL TAF SITES SUNDAY AFTERNOON...GENERALLY
BETWEEN 19Z SUNDAY AND 01Z MONDAY DUE TO THE SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS THAT ARE EXPECTED.
CALM OR LIGHT SOUTH WINDS FOR THE REST OF TONIGHT...THEN BECOMING
SOUTH TO SOUTHWEST AT 5-10 KT LATE SUNDAY MORNING INTO THE
AFTERNOON. WINDS WILL BE STRONGER...AND VARIABLE IN DIRECTION IN AND
NEAR ANY THUNDERSTORMS.
OUTLOOK...
SUN NT...MVFR...CHC IFR...SHWRS AND TSTRMS.
MON-WED...VFR/MVFR. ISOLD-SCT SHOWERS/TSTMS.
&&
.FIRE WEATHER...
AN UPPER LEVEL DISTURBANCE IN THE OHIO VALLEY AND GREAT LAKES
WILL BRING A CHANCE OF SIGNIFICANT SHOWERS AND POSSIBLY
THUNDERSTORMS ON SUNDAY. MORE ISOLATED TO SCATTERED THUNDERSTORMS
ARE POSSIBLE THROUGH WEDNESDAY AS A WARM AND HUMID AIRMASS STAYS
OVER OUR REGION.
THE DISTURBANCE ON SUNDAY SHOULD BRING SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS AND HUMID CONDITIONS. THIS SYSTEM HAS
THE POTENTIAL TO BRING 0.25 INCHES OR MORE...MAINLY SOUTH OF
ALBANY.
HIGH PRESSURE WILL BUILD EAST FROM THE OHIO VALLEY INTO OUR REGION
ON MONDAY...BRINGING MORE HOT WEATHER.
RELATIVE HUMIDITY VALUES WILL RECOVER TO 80 TO 100 PERCENT
TONIGHT...AND REMAIN ELEVATED 60 TO 80 PERCENT MOST OF SUNDAY.
HUMIDITY VALUES WILL REMAIN ELEVATED THROUGH MONDAY...DESPITE NO
MORE RAIN EXPECTED.
ONLY ISOLATED THUNDERSTORMS ARE EXPECTED MONDAY AND TUESDAY WITH
POSSIBLY MORE SIGNIFICANT ACTIVITY ON WEDNESDAY.
THE SURFACE WIND WILL BE LIGHT AND VARIABLE AND GENERALLY 10 MPH OR
LESS. LOCALLY HIGHER GUSTS ARE POSSIBLE WITH ANY THUNDERSTORM.
&&
.HYDROLOGY...
NO SIGNIFICANT HYDRO PROBLEMS ARE EXPECTED FOR THE NEXT FIVE DAYS.
SCATTERED SHOWERS AND THUNDERSTORMS...MAINLY IN AREAS OF TERRAIN
THIS AFTERNOON...COULD PRODUCE VERY LOCALIZED AMOUNTS OVER HALF
AN INCH. HOWEVER...RAINFALL BASIN AVERAGE WILL REMAIN WELL BELOW
0.25 INCHES WITH NO EFFECT ON THE SLUGGISH WATERSHEDS.
THERE IS POTENTIAL FOR A AVERAGE RIVER BASIN QUARTER INCH OR MORE OF
RAINFALL...MAINLY SOUTH OF ALBANY ON SUNDAY. SOME LOCALITIES COULD
RECEIVE OVER AN INCH OF RAINFALL FROM DOWNPOURS. FURTHER
NORTH...FROM ALBANY NORTHWARD...IT LOOKS AS LESS THAN A QUARTER OF
AN INCH OF RAIN WILL FALL ACROSS THE RIVER BASIN.
EITHER WAY...EVEN THESE RAIN WILL BE ONLY MINOR RELIEF FROM OUR
INCREASE DRY SPELL...WITH NO RISES ON ANY RIVERS EXPECTED.
AFTER SUNDAY...OUR NEXT CHANCE OF ANY REAL SHOWERS AND STORMS WILL
BE LATE TUESDAY OR EARLY WEDNESDAY WITH THE PASSAGE OF A PRETTY
STRONG COLD FRONT FOR THE TIME OF YEAR.
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...HWJIV
NEAR TERM...HWJIV/KL
SHORT TERM...HWJIV/NAS
LONG TERM...KL
AVIATION...GJM
FIRE WEATHER...NAS
HYDROLOGY...NAS
AREA FORECAST DISCUSSION
NWS ALBANY NY
150 AM EDT SUN JUL 15 2012
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE IN THE OHIO VALLEY AND GREAT LAKES WILL
BRING A CHANCE OF BENEFICIAL SHOWERS AND POSSIBLY THUNDERSTORMS
TODAY. HIGH PRESSURE WILL BUILD FROM THE OHIO VALLEY MONDAY AND
TUESDAY WITH MAINLY SUNNY HOT CONDITIONS.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 130 AM...REGIONAL RADARS INDICATED CONVECTION IN PA WILL
LIKELY REMAIN OUT OF OUR REGION THROUGH ABOUT 12Z. THEREFORE WENT
AHEAD AND REMOVED POPS UNTIL THEN. IT SHOULD BE NOTED THAT THE
LATEST HRRR EXPERIMENTAL MODEL DID BRING A CLUSTER OF SHOWERS INTO
THE SCHOHARIE VALLEY AT 10Z...BUT THEN DISSIPATED THEM RIGHT AFTER
THAT. NOT BUYING INTO THIS SOLUTION.
SOME HIGH CLOUDINESS OVER THE REGION AND WAS GENERALLY THICKENING.
MANY SPOTS STILL REPORTING A BREEZE AROUND 5 MPH OR SO. DECIDED TO
RAISE TEMPS 1-3 DEGS IN A FEW SPOTS OVERNIGHT.
UPSTREAM CLOUDS WERE THICKENING EVEN MORE ACROSS THE GREAT LAKES
WHERE A PRETTY POTENT SHORT WAVE WAS. THIS WILL BE THE SYSTEM TO
AFFECT OUR REGION LATER TODAY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
RELATIVELY WELL DEFINED UPPER IMPULSE PREDICTED BY GUIDANCE AND
ENSEMBLES TO TRACK THROUGH THE REGION SUNDAY. WHILE CONVECTION HAS
DIMINISHED FROM EARLIER...A LOT OF MID LEVEL CLOUDS INDICATED LOTS
OF DEEP LAYER MOISTURE. THERE SHOULD BE MORE CLOUDS THAN SUN SUNDAY
WITH LIKELY SHOWERS AND THUNDERSTORMS BY MIDDAY. DID TEMPER THE POPS
BACK A LITTLE DURING THE MORNING.
LOW LEVEL JET ENERGY IS RELATIVELY WEAK...AND THERE SHOULD BE VERY
LITTLE THERMAL FORCING...SO CONVECTION SHOULD BE MOSTLY HEAVY
RAINERS...ALTHOUGH WITH THE INSTABILITY IN PLACE...AND SOME BREAKS
IN THE CLOUDS...ALONG WITH HIGHS IN THE 80S IN MOST AREAS...SOME
VERY ISOLATED STRONG WINDS AND HAIL ARE POSSIBLE. ANY AREAS THAT
COULD SEE A PROLONGED PERIOD OF SUN COULD SEE HIGHS AROUND 90...BUT
THAT LOOKS INCREASINGLY UNLIKELY THAT TEMPS WOULD GET THAT HIGH.
GUIDANCE SUGGESTS THE UPPER SYSTEM IS PREDICTED TO EXIT THE REGION
SUNDAY NIGHT INTO MONDAY...BUT STAY TUNED AS GUIDANCE OFTEN DOES
NOT TIME THE MOVEMENT OF CONVECTIVELY BASED SYSTEMS WELL. THE
WARM AND HUMID AIRMASS SHOULD STILL BE OVER THE REGION...BUT NO
ORGANIZED LOW LEVEL FOCUS OTHER THAN OLD OUFLOW BOUNDARIES.
SO...GRADUAL CLEARING...AND MAYBE SOME FOG SUNDAY NIGHT...THEN
CONTINUED DECREASING CLOUDS MONDAY... WITH JUST VERY ISOLATED
THUNDERSTORMS POSSIBLE...NOT ENOUGH TO ACKNOWLEDGE IN FORECAST
YET. HIGHS IN THE 80S TO MID 90S. ANOTHER WARM AND HUMID NIGHT
MONDAY NIGHT WITH LOWS IN THE 60S TO NEAR 70.
SOME SLIGHT WARMING OF THE BOUNDARY LAYER WELL AHEAD OF THE NEXT
APPROACHING SYSTEM. LOW LEVEL JET ENERGY GRADUALLY INCREASES...
ESPECIALLY IN NORTHERN AREAS BY LATER TUESDAY AFTERNOON. SOME
ISOLATED THUNDERSTORMS ARE POSSIBLE...ESPECIALLY IN AREAS OF
TERRAIN. HIGHS AGAIN WELL INTO THE 80S TO LOWER 90S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HAVE GENERALLY POPULATED THIS PORTION OF GRIDDED DATABASE WITH A
50/50 BLEND OF 18Z HPC MOS...AND 12Z/GMOS.
TUE NT-WED NT...BROAD UPPER LEVEL TROUGH IS EXPECTED TO DEVELOP
ACROSS EAST CENTRAL CANADA EXTENDING INTO THE EASTERN GREAT
LAKES...WITH AN ATTENDANT SFC COLD FRONT APPROACHING FROM THE GREAT
LAKES DURING THIS PERIOD. THERE ARE SOME TIMING DIFFERENCES IN SFC
FROPA ACROSS THE REGION...WITH THE 12Z/GFS SLIGHTLY
FASTER...OCCURRING MIDDAY TUESDAY FROM ALBANY N AND W...AND THE
AFTERNOON TO THE S/E...AND THE 12Z/ECMWF A BIT SLOWER...GEN RALLY
DURING THE AFTERNOON/EVENING HOURS. WILL INDICATE CHC POPS FOR MUCH
OF THE DAY...ALTHOUGH WILL TAPER ACROSS NW AREAS LATER IN THE DAY
WITH EXPECTATION FOR MAIN FROPA TO OCCUR EARLIER. FOR WED NT...WILL
KEEP SOME POPS THROUGH THE EVENING HOURS FOR AREAS S/E OF
ALBANY...TO ACCOUNT FOR POSSIBILITY OF SLIGHTLY SLOWER FROPA.
OTHERWISE...EXPECT A VERY WARM/HUMID NIGHT TUE NT/EARLY WED
AM...WITH MINS ONLY FALLING INTO THE UPPER 60S TO LOWER 70S ACROSS
MUCH OF THE HUDSON RIVER VALLEY AND MOHAWK RIVER VALLEY...WITH
LOWER/MID 60S ELSEWHERE. ON WED...GENERALLY EXPECT MAXES TO REACH
85-90 IN THE HUDSON RIVER VALLEY FROM ALBANY SOUTH...AND 80-85
NORTH...WITH GENERALLY UPPER 70S TO MID 80S ELSEWHERE. SOME AREAS
COULD BE WARMER FROM ALBANY S AND E SHOULD MORE SUNSHINE OCCUR WED
AM THAN CURRENTLY EXPECTED. BY WED NT/THU AM...EXPECT SOMEWHAT
COOLER/LESS HUMID CONDITIONS TO FILTER INTO THE REGION...WITH MINS
FALLING TO 60-65 WITHIN THE HUDSON RIVER VALLEY/MOHAWK RIVER
VALLEYS...AND 55-60 ELSEWHERE...ALTHOUGH SOME LOWER 50S WILL BE
POSSIBLE WITHIN PORTIONS OF THE SOUTHERN ADIRONDACKS.
THU-SAT...EXPECT DRY CONDITIONS...AS A SFC HIGH SLOWLY BUILDS INTO
THE REGION FROM THE GREAT LAKES. TEMPS MAY EVEN BE A BIT BELOW
SEASONAL LEVELS THU-FRI...GIVEN POTENTIAL 850 TEMPS FALLING INTO THE
+8 TO +10C RANGE...BEFORE WARMING TO NEAR OR ABOVE NORMAL BY
FRI-SAT. THIS TRANSLATES INTO MAX TEMPS IN THE UPPER 70S/LOWER 80S
IN VALLEYS THU...AND LOWER/MID 80S FRI-SAT...WITH OVERNIGHT MINS
FALLING INTO THE 50S IN MOST AREAS...WITH SOME 40S POSSIBLE ACROSS
PORTIONS OF THE SOUTHERN ADIRONDACKS/NORTH COUNTRY FRI AM.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS ARE EXPECTED EARLY THIS EVENING. THEN...EXPECT
AREAS OF MVFR VSBYS TO DEVELOP DUE TO BR. THERE IS A SLIGHT CHANCE
THAT PATCHY GROUND FOG AND IFR VSBYS COULD DEVELOP AFTER
07Z...ESP AT KGFL AND KPSF...BUT OVERALL PROBABILITY TOO LOW TO
MENTION IN CURRENT TAFS.
ANY AREAS OF MVFR/IFR VSBYS SHOULD GIVE WAY TO VFR CONDITIONS
SUNDAY MORNING. HOWEVER...AS SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS DEVELOP IN THE AFTERNOON...SOME REDUCTIONS INTO THE
MVFR/IFR RANGE ARE POSSIBLE.
HAVE INCLUDED MENTION OF VCTS FOR ALL TAF SITES SUNDAY
AFTERNOON...AS SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE
EXPECTED.
LIGHT SOUTH WINDS WILL BECOME NEARLY CALM OVERNIGHT. WINDS WILL
BECOME SOUTH TO SOUTHWEST AT 5-10 KT LATE SUNDAY MORNING INTO THE
AFTERNOON. WINDS WILL BE STRONGER...AND VARIABLE IN DIRECTION IN
AND NEAR ANY THUNDERSTORMS.
OUTLOOK...
SUN NT...MVFR...CHC IFR...SHWRS AND TSTRMS.
MON-WED...VFR/MVFR. ISOLD-SCT SHOWERS/TSTMS.
&&
.FIRE WEATHER...
AN UPPER LEVEL DISTURBANCE IN THE OHIO VALLEY AND GREAT LAKES
WILL BRING A CHANCE OF SIGNIFICANT SHOWERS AND POSSIBLY
THUNDERSTORMS ON SUNDAY. MORE ISOLATED TO SCATTERED THUNDERSTORMS
ARE POSSIBLE THROUGH WEDNESDAY AS A WARM AND HUMID AIRMASS STAYS
OVER OUR REGION.
THE DISTURBANCE ON SUNDAY SHOULD BRING SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS AND HUMID CONDITIONS. THIS SYSTEM HAS
THE POTENTIAL TO BRING 0.25 INCHES OR MORE...MAINLY SOUTH OF
ALBANY.
HIGH PRESSURE WILL BUILD EAST FROM THE OHIO VALLEY INTO OUR REGION
ON MONDAY...BRINGING MORE HOT WEATHER.
RELATIVE HUMIDITY VALUES WILL RECOVER TO 80 TO 100 PERCENT
TONIGHT...AND REMAIN ELEVATED 60 TO 80 PERCENT MOST OF SUNDAY.
HUMIDITY VALUES WILL REMAIN ELEVATED THROUGH MONDAY...DESPITE NO
MORE RAIN EXPECTED.
ONLY ISOLATED THUNDERSTORMS ARE EXPECTED MONDAY AND TUESDAY WITH
POSSIBLY MORE SIGNIFICANT ACTIVITY ON WEDNESDAY.
THE SURFACE WIND WILL BE LIGHT AND VARIABLE AND GENERALLY 10 MPH OR
LESS. LOCALLY HIGHER GUSTS ARE POSSIBLE WITH ANY THUNDERSTORM.
&&
.HYDROLOGY...
NO SIGNIFICANT HYDRO PROBLEMS ARE EXPECTED FOR THE NEXT FIVE DAYS.
SCATTERED SHOWERS AND THUNDERSTORMS...MAINLY IN AREAS OF TERRAIN
THIS AFTERNOON...COULD PRODUCE VERY LOCALIZED AMOUNTS OVER HALF
AN INCH. HOWEVER...RAINFALL BASIN AVERAGE WILL REMAIN WELL BELOW
0.25 INCHES WITH NO EFFECT ON THE SLUGGISH WATERSHEDS.
THERE IS POTENTIAL FOR A AVERAGE RIVER BASIN QUARTER INCH OR MORE OF
RAINFALL...MAINLY SOUTH OF ALBANY ON SUNDAY. SOME LOCALITIES COULD
RECEIVE OVER AN INCH OF RAINFALL FROM DOWNPOURS. FURTHER
NORTH...FROM ALBANY NORTHWARD...IT LOOKS AS LESS THAN A QUARTER OF
AN INCH OF RAIN WILL FALL ACROSS THE RIVER BASIN.
EITHER WAY...EVEN THESE RAIN WILL BE ONLY MINOR RELIEF FROM OUR
INCREASE DRY SPELL...WITH NO RISES ON ANY RIVERS EXPECTED.
AFTER SUNDAY...OUR NEXT CHANCE OF ANY REAL SHOWERS AND STORMS WILL
BE LATE TUESDAY OR EARLY WEDNESDAY WITH THE PASSAGE OF A PRETTY
STRONG COLD FRONT FOR THE TIME OF YEAR.
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...HWJIV
NEAR TERM...HWJIV/KL
SHORT TERM...HWJIV/NAS
LONG TERM...KL
AVIATION...KL/BGM
FIRE WEATHER...NAS
HYDROLOGY...NAS
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
345 PM EDT Sun Jul 15 2012
.NEAR TERM [through Tonight]...
While the dry mid-upper troposphere will help limit the overall
coverage and intensity of deep moist convection through this
evening, there will be enough boundary layer moisture and influx of
moisture from the Atlantic for scattered, "more shallow" convection.
The greatest rain chance will be east of Tallahassee and Albany,
where a combination of the FL/GA east coast sea breeze front,
boundary layer moisture, and instability will be enough to support a
40-50% chance of rain. So far cloud-ground lightning and surface
wind gusts have been on the low side with the cells to our east, and
this will likely continue. One or two cells could become briefly
strong (with wind gusts to 40 MPH and brief heavy rain), but the
chance of severe storms (58 MPH+ and/or large hail) is low.
Most of the rain over land will diminish shortly after sunset, but
scattered showers and storms will likely persist over the Gulf
coastal waters as the sea breeze translates westward. Low tonight
will be typical for this time of year, in the lower to mid 70s.
&&
.SHORT TERM [Monday through Tuesday Night]...
The forecast for the early part of the week will be influenced by
the progression of a TUTT ("Tropical Upper Tropospheric Trough")
and TUTT low currently situated to the east of the area. The TUTT
low is very well defined on water vapor loops this afternoon,
spinning near 31.2N / 78.2W. The upper level trough extends SW
from there over S FL and towards the Yucatan. The TUTT low, and
associated trough, are expected to slowly drift to the west over
the next couple days, with the low near GNV by Monday afternoon,
and near Apalachee Bay by Tuesday afternoon. The question is how
fast the aforementioned pocket of mid-upper level dry air will be
eroded by the approaching trough. The GFS and RUC both indicate
that should occur overnight, with PWATS reaching values much
closer to climatological normals by Monday. So far this weekend, a
lot of the convection has been situated near or east of the TUTT
axis, which means that it could take until Tuesday for a notable
increase in PoPs across the entire area. Therefore, for Monday we
expect more isolated activity (20-30% PoPs) in the NW half of the
area, with scattered to numerous storms (45-60% PoPs) around the
Florida Big Bend near Apalachee Bay. By Tuesday, we will be more
underneath the TUTT axis, and the low-level flow pattern will be
transitioning from light and variable to southerly. Therefore, the
increased forcing for ascent in the mid and upper levels, as well
as the local sea-breeze climatology both favor higher PoPs over
the entire area. PoPs were bumped up to about 50% in most areas.
There are some hints that the atmosphere could become a little
more favorable for downbursts in stronger storms in the short term
period as well, but this remains uncertain.
.LONG TERM [Wednesday through Sunday]...
Very little change to the extended fcst this cycle as the latest
00 UTC GFS and ECMWF have remained in fairly good agreement with a
Synoptic pattern dominated by a TUTT Low which will gradually open
up into an Upper Level Trof. This should further increase fcst
confidence in above Climo Pops and near Climo Max Temps through
much of the period. Despite the fairly disturbed pattern, the MEX
High Temps appeared too high (Mid 90s in many areas away from the
coast) for the expected levels of cloud cover and rain chances, so
used a 2-1 Blend of the lower and more realistic looking HPC and
MOS Guidance grids. The Euro (and GFS to some extent) do both show
some potential for a brief break in this pattern on Friday, with
possible Upper Level Ridging moving in from the east, before the
mean Trof builds back southward over the weekend, bringing a
return to higher rain chances.
&&
.AVIATION...
[through 18z Monday] KECP and KVLD are likely to be only
terminals affected by TSRA/SHRA today, with brief IFR-MVFR
vis/cigs and gusty winds through late afternoon or early evening.
The PoP is too low elsewhere to include in this afternoon`s TAF
package. Some of the high resolution NWP indicate the potential
for low clouds/fog around KVLD early Monday morning, but our
confidence is not yet high enough to include this in the forecast.
&&
.MARINE...
Very benign weather pattern for the marine forecast in terms of
winds and seas. Weak surface pressure pattern should keep winds at
or below 10 knots, and seas should therefore be 2 feet or less.
The approaching upper level low for Monday and Tuesday may begin
to increase thunderstorm coverage over the waters early this week,
particularly during the overnight and early morning hours.
&&
.FIRE WEATHER...
Relative humidity levels are unlikely to reach critical values for
the next several days. This, along with near-climo rain chances
(40-50%) over the next several days, will make controlled burning
difficult.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 73 92 73 91 74 / 30 50 20 50 30
Panama City 75 91 76 88 76 / 20 30 20 30 30
Dothan 74 95 75 93 74 / 20 30 20 50 30
Albany 72 95 74 94 74 / 20 30 20 50 40
Valdosta 71 93 71 92 72 / 30 40 20 50 40
Cross City 71 91 72 89 72 / 50 50 20 50 30
Apalachicola 75 89 76 87 76 / 20 40 20 30 20
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...None.
GA...None.
FL...None.
MARINE...None.
&&
$$
Near Term...Fournier
Short Term...Lamers
Long Term...Gould
Aviation...Fournier
Marine...Lamers
Fire Weather...Fournier
AREA FORECAST DISCUSSION...Updated
NWS TALLAHASSEE FL
700 AM EDT Sun Jul 15 2012
Updated Aviation Discussion.
.NEAR TERM [Through Today]...
A rather amplified and complex upper level pattern is depicted
this morning by the 05z RAP analysis. Two shortwave troughs across
the Pacific Northwest and the Upper Midwest are complimented by
two ridges across the Plains states and the Southeast states.
Pinched off from the easternmost trough is a weak closed low
centered over the Southern Plains. Finally, a TUTT draped across
the western Caribbean, northeast into the western Atlantic,
continues its slow westward progression.
For this afternoon, subsidence provided by the southeastern U.S.
ridge will provide our local area with slightly drier conditions.
That being said, precipitable water levels are expected to remain
at or slightly above climatological normals for this time of year.
With no large scale support for ascent expected, the local
seabreeze fronts will dominate this afternoon`s weather pattern.
With slightly more easterly flow regime expected today, a slightly
modified regime 2 is expected. This regime would favor the
Panhandle Seabreeze Front and the East Coast Seabreeze Front. Thus
PoPs are highest across the Florida Panhandle, and later across
our eastern counties in Georgia and Florida.
With respect to the threat for severe weather, no severe weather
is expected across our Florida counties this afternoon. Lower than
normal instability coupled with several other poor to marginal
thermodynamic variables will be the limiting factors here. There
does exist a slight chance for severe storms across our Georgia
and Alabama counties today, with a few caveats. Drier mid-level
air will increase the theta-e differences between the middle and
lower troposphere. This coupled with steep low level lapse rates
will increase the threat for severe downbursts. However, the dry
air may also be the limiting factor in storm development. The best
case scenario for severe storm development across Georgia would
be late in the afternoon/early evening when the East Coast
Seabreeze enters the primed atmosphere. The same story holds true
for southeast Alabama, with a different forcing mechanism. Any
storms that for across Alabama will likely be due to boundary
interactions from the Panhandle Seabreeze. A late afternoon/early
evening threat timeline is expected across Alabama as well.
Waterspouts will be possible again today, primarily along eastward
facing Big Bend beaches due to the more easterly wind component.
The threat should diminish by the afternoon with the diminishing
wind enhancement behind yesterday`s East Coast Seabreeze Front.
&&
.SHORT TERM [Tonight Through Tuesday]...
Seabreeze circulations will continue to influence the
precipitation pattern through the remainder of the short term.
However, beginning Monday, the aforementioned TUTT will move
southwest into our eastern forecast area. This will especially
enhance PoPs across north Florida, east of the Apalachicola
River. On Tuesday, the trough will overspread our entire forecast
area enhancing PoPs area wide.
Temperatures will hold near climatological averages in the lower
90s each afternoon, and the lower 70s each night.
&&
.LONG TERM [Tuesday Night through Sunday]...
Very little change to the extended fcst this cycle as the latest
00 UTC GFS and ECMWF have remained in fairly good agreement with a
Synoptic pattern dominated by a TUTT Low which will gradually open
up into an Upper Level Trof. This should further increase fcst
confidence in above Climo Pops and near Climo Max Temps through
much of the period. Despite the fairly disturbed pattern, the MEX
High Temps appeared too high (Mid 90s in many areas away from the
coast) for the expected levels of cloud cover and rain chances, so
used a 2-1 Blend of the lower and more realistic looking HPC and
MOS Guidance grids. The Euro (and GFS to some extent) do both show
some potential for a brief break in this pattern on Friday, with
possible Upper Level Ridging moving in from the east, before the
mean Trof builds back southward over the weekend, bringing a
return to higher rain chances.
&&
.AVIATION...
The Hi-Res models turned out to be correct, as VFR conditions
prevailed through the night and early morning at all of the
terminals. For the remainder of today, VFR conditions should prevail
with slightly lower PoPs than yesterday...especially further to the
north. Did upgrade ECP and VLD to convective tempos, with VCTS at
TLH, and just VFR the rest of the day at ABY and DHN.
&&
.MARINE...
Winds and seas will remain below headline criteria for the next
several days as the subtropical ridge keeps a firm hold on the
region. Enhancements nearing SCEC criteria are possible this
morning and tomorrow morning along the East Coast Seabreeze Front.
Flow will shift more southerly by Tuesday, effectively ending the
East Coast Seabreeze enhancements.
&&
.FIRE WEATHER...
Still no fire weather concerns in sight over the foreseeable
future across the Tri-State area, as ample low-level moisture will
keep afternoon relative humidities fairly high through the period.
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
MARINE...None.
&&
$$
NEAR TERM...Harrigan
SHORT TERM...Harrigan
LONG TERM...Gould
AVIATION...Gould
MARINE...Harrigan
FIRE WEATHER...Gould
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
454 AM EDT Sun Jul 15 2012
.NEAR TERM [Through Today]...
A rather amplified and complex upper level pattern is depicted
this morning by the 05z RAP analysis. Two shortwave troughs across
the Pacific Northwest and the Upper Midwest are complimented by
two ridges across the Plains states and the Southeast states.
Pinched off from the easternmost trough is a weak closed low
centered over the Southern Plains. Finally, a TUTT draped across
the western Caribbean, northeast into the western Atlantic,
continues its slow westward progression.
For this afternoon, subsidence provided by the southeastern U.S.
ridge will provide our local area with slightly drier conditions.
That being said, precipitable water levels are expected to remain
at or slightly above climatological normals for this time of year.
With no large scale support for ascent expected, the local
seabreeze fronts will dominate this afternoon`s weather pattern.
With slightly more easterly flow regime expected today, a slightly
modified regime 2 is expected. This regime would favor the
Panhandle Seabreeze Front and the East Coast Seabreeze Front. Thus
PoPs are highest across the Florida Panhandle, and later across
our eastern counties in Georgia and Florida.
With respect to the threat for severe weather, no severe weather
is expected across our Florida counties this afternoon. Lower than
normal instability coupled with several other poor to marginal
thermodynamic variables will be the limiting factors here. There
does exist a slight chance for severe storms across our Georgia
and Alabama counties today, with a few caveats. Drier mid-level
air will increase the theta-e differences between the middle and
lower troposphere. This coupled with steep low level lapse rates
will increase the threat for severe downbursts. However, the dry
air may also be the limiting factor in storm development. The best
case scenario for severe storm development across Georgia would
be late in the afternoon/early evening when the East Coast
Seabreeze enters the primed atmosphere. The same story holds true
for southeast Alabama, with a different forcing mechanism. Any
storms that for across Alabama will likely be due to boundary
interactions from the Panhandle Seabreeze. A late afternoon/early
evening threat timeline is expected across Alabama as well.
Waterspouts will be possible again today, primarily along eastward
facing Big Bend beaches due to the more easterly wind component.
The threat should diminish by the afternoon with the diminishing
wind enhancement behind yesterday`s East Coast Seabreeze Front.
&&
.SHORT TERM [Tonight Through Tuesday]...
Seabreeze circulations will continue to influence the
precipitation pattern through the remainder of the short term.
However, beginning Monday, the aforementioned TUTT will move
southwest into our eastern forecast area. This will especially
enhance PoPs across north Florida, east of the Apalachicola
River. On Tuesday, the trough will overspread our entire forecast
area enhancing PoPs area wide.
Temperatures will hold near climatological averages in the lower
90s each afternoon, and the lower 70s each night.
&&
.LONG TERM [Tuesday Night through Sunday]...
Very little change to the extended fcst this cycle as the latest
00 UTC GFS and ECMWF have remained in fairly good agreement with a
Synoptic pattern dominated by a TUTT Low which will gradually open
up into an Upper Level Trof. This should further increase fcst
confidence in above Climo Pops and near Climo Max Temps through
much of the period. Despite the fairly disturbed pattern, the MEX
High Temps appeared too high (Mid 90s in many areas away from the
coast) for the expected levels of cloud cover and rain chances, so
used a 2-1 Blend of the lower and more realistic looking HPC and
MOS Guidance grids. The Euro (and GFS to some extent) do both show
some potential for a brief break in this pattern on Friday, with
possible Upper Level Ridging moving in from the east, before the
mean Trof builds back southward over the weekend, bringing a
return to higher rain chances.
&&
.AVIATION...
A bit more of a challenging Taf package for the overnight and
early morning hours than last night, as the numerical guidance
(which is fairly pessimistic at many of the Terminals) is split
with the Hi-Res models which are generally keeping VFR conditions
through the night. Although conditions could worsen a bit more
than expected with no Cirrus Canopy tonight, decided on only tempo
MVFR conditions at DHN and ABY for this package. On Sunday, expect
the convective coverage to be lower than Saturday with the more of
an easterly flow developing, so only went with Prob30s at ECP and
VLD, with VCTS at TLH, and just VFR the rest of the day at ABY and
DHN.
&&
.MARINE...
Winds and seas will remain below headline criteria for the next
several days as the subtropical ridge keeps a firm hold on the
region. Enhancements nearing SCEC criteria are possible this
morning and tomorrow morning along the East Coast Seabreeze Front.
Flow will shift more southerly by Tuesday, effectively ending the
East Coast Seabreeze enhancements.
&&
.FIRE WEATHER...
Still no fire weather concerns in sight over the foreseeable
future across the Tri-State area, as ample low-level moisture will
keep afternoon relative humidities fairly high through the period.
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
MARINE...None.
&&
$$
NEAR TERM...Harrigan
SHORT TERM...Harrigan
LONG TERM...Gould
AVIATION...Gould
MARINE...Harrigan
FIRE WEATHER...Gould
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
323 AM EDT Sun Jul 15 2012
.NEAR TERM [Through Today]...
A rather amplified and complex upper level pattern is depicted
this morning by the 05z RAP analysis. Two shortwave troughs across
the Pacific Northwest and the Upper Midwest are complimented by
two ridges across the Plains states and the Southeast states.
Pinched off from the easternmost trough is a weak closed low
centered over the Southern Plains. Finally, a TUTT draped across
the western Caribbean, northeast into the western Atlantic,
continues its slow westward progression.
For this afternoon, subsidence provided by the southeastern U.S.
ridge will provide our local area with slightly drier conditions.
That being said, precipitable water levels are expected to remain
at or slightly above climatological normals for this time of year.
With no large scale support for ascent expected, the local
seabreeze fronts will dominate this afternoon`s weather pattern.
With slightly more easterly flow regime expected today, a slightly
modified regime 2 is expected. This regime would favor the
Panhandle Seabreeze Front and the East Coast Seabreeze Front. Thus
PoPs are highest across the Florida Panhandle, and later across
our eastern counties in Georgia and Florida.
With respect to the threat for severe weather, no severe weather
is expected across our Florida counties this afternoon. Lower than
normal instability coupled with several other poor to marginal
thermodynamic variables will be the limiting factors here. There
does exist a slight chance for severe storms across our Georgia
and Alabama counties today, with a few caveats. Drier mid-level
air will increase the theta-e differences between the middle and
lower troposphere. This coupled with steep low level lapse rates
will increase the threat for severe downbursts. However, the dry
air may also be the limiting factor in storm development. The best
case scenario for severe storm development across Georgia would
be late in the afternoon/early evening when the East Coast
Seabreeze enters the primed atmosphere. The same story holds true
for southeast Alabama, with a different forcing mechanism. Any
storms that for across Alabama will likely be due to boundary
interactions from the Panhandle Seabreeze. A late afternoon/early
evening threat timeline is expected across Alabama as well.
Waterspouts will be possible again today, primarily along eastward
facing Big Bend beaches due to the more easterly wind component.
The threat should diminish by the afternoon with the passage of
yesterday`s East Coast Seabreeze Front.
&&
.SHORT TERM [Tonight Through Tuesday]...
Seabreeze circulations will continue to influence the
precipitation pattern through the remainder of the short term.
However, beginning Monday, the aforementioned TUTT will move
southwest into our eastern forecast area. This will especially
enhance PoPs across north Florida, east of the Apalachicola
River. On Tuesday, the trough will overspread our entire forecast
area enhancing PoPs area wide.
Temperatures will hold near climatological averages in the lower
90s each afternoon, and the lower 70s each night.
&&
.LONG TERM [Tuesday Night through Sunday]...
Updating shortly...
&&
.AVIATION...
A bit more of a challenging Taf package for the overnight and
early morning hours than last night, as the numerical guidance
(which is fairly pessimistic at many of the Terminals) is split
with the Hi-Res models which are generally keeping VFR conditions
through the night. Although conditions could worsen a bit more
than expected with no Cirrus Canopy tonight, decided on only tempo
MVFR conditions at DHN and ABY for this package. On Sunday, expect
the convective coverage to be lower than Saturday with the more of
an easterly flow developing, so only went with Prob30s at ECP and
VLD, with VCTS at TLH, and just VFR the rest of the day at ABY and
DHN.
&&
.MARINE...
Winds and seas will remain below headline criteria for the next
several days as the subtropical ridge keeps a firm hold on the
region. Enhancements nearing SCEC criteria are possible this
morning and tomorrow morning along the East Coast Seabreeze Front.
Flow will shift more southerly by Tuesday, effectively ending the
East Coast Seabreeze enhancements.
&&
.FIRE WEATHER...
Updating shortly...
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
MARINE...None.
&&
$$
NEAR TERM...Harrigan
SHORT TERM...Harrigan
LONG TERM...Gould
AVIATION...Gould
MARINE...Harrigan
FIRE WEATHER...Gould
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1015 AM EDT SUN JUL 15 2012
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL EXTEND ACROSS THE REGION AS
A WEAK TROUGH OF LOW PRESSURE DEVELOPS INLAND. A COLD FRONT WILL
APPROACH FROM THE NORTH LATE IN THE WEEK AND LIKELY STALL OUT
THROUGH THE WEEKEND LEADING TO UNSETTLED CONDITIONS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATE MORNING WATER VAPOR IMAGERY SHOWS A WELL DEFINED TUTT LOW
SPINNING IN THE VICINITY OF 31.3N/-76.9W. DRY AIR ALONG ITS
WESTERN PERIPHERY HAS INFILTRATED SOUTHEAST SOUTH CAROLINA AND
SOUTHEAST GEORGIA WITH PWATS MEASURED ON THE 15/12Z CHS RAOB WELL
BELOW 2 INCHES. THE ATMOSPHERE REMAINS TROPICAL DESPITE THE
PRESENCE OF MID-LEVEL DRY AIR WITH A DEEP/MOIST FLOW FROM OF THE
ATLANTIC HELPING TO ADVECT RICH LOW-LEVEL THETA AIR INTO THE
REGION. CONVECTIVE TEMPERATURES ARE JUST ABOUT TO BE SURPASSED PER
REGIONAL RAP BUFR SOUNDINGS AND IN FACT SHOWER ACTIVITY IS
ALREADY BEGINNING TO BLOSSOM AS EXPECTED ALONG THE COAST.
CONVECTION WILL CONTINUE TO EXPAND OVER THE NEXT SEVERAL HOURS
WITH SCATTERED SHOWERS/TSTMS EXPECTED TO CONCENTRATE INLAND AHEAD
OF AN ILL-DEFINED PURE SEA BREEZE CIRCULATION OVER THE NEXT
SEVERAL HOURS. OPTED TO MODIFY THE CURRENT POP REGIME SLIGHTLY TO
HIGHLIGHT A LARGER AREA OF CHANCE POPS OF 30-40 PERCENT. CONVECTION
SHOULD GRADUALLY END FROM EAST-WEST LATER THIS AFTERNOON IN THE
WAKE OF THE SEA BREEZE. NUDGED HIGHS DOWN JUST A DEGREE OR TWO FOR
MOST AREAS. HIGHS WILL RANGE FROM THE LOWER 90S INLAND TO THE MID
80S AT THE BEACHES.
THE RISK FOR A FEW STRONG TO SEVERE TSTMS WILL BE A BIT HIGHER
COMPARED TO THE PAST SEVERAL DAYS WITH SLIGHTLY DRIER MID-LEVEL
AIR NOW IN PLACE. THERMODYNAMIC PARAMETERS ON THE MODIFIED 15/12Z
CHS RAOB DEPICTED DCAPES NEAR 1400 J/KG WITH A WINDEX NEAR 60
KT...WHICH IS SUPPORTIVE OF AN ENHANCED WET MICROBURST
ENVIRONMENT. ATTM THINK THE RISK IS LIKELY TOO LOW TO JUSTIFY A
MENTION IN THE HAZARDOUS WEATHER OUTLOOK...BUT ONE OR TWO SEVERE
TSTM WARNINGS CAN NOT BE COMPLETELY RULED OUT THROUGH MID-LATE
AFTERNOON...MAINLY INLAND.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
THE CONVECTION WILL DIMINISH OVER LAND WITH THE SUNSET...SO MOST
PLACES WILL BE DRY DURING SUNDAY EVENING. ONCE AGAIN...SCATTERED
SHOWERS SHOULD AGAIN REDEVELOP OVER THE COASTAL WATERS AND MOVE
TOWARD THE COAST DURING THE LATE NIGHT HOURS...BUT MOST ACTIVITY
SHOULD REMAIN OFFSHORE.
A MID/UPPER-LEVEL LOW PRESSURE SYSTEM WILL MOVE ONSHORE MONDAY AND
THEN SHIFT SOUTHWEST OF THE AREA TUESDAY AND WEDNESDAY. MAINLY
AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS EACH DAY WITH PROBABLY
THE BETTER COVERAGE COMING TUESDAY AND WEDNESDAY AS A SURFACE TROUGH
OF LOW PRESSURE DEVELOPS INLAND. TEMPERATURES GENERALLY NEAR NORMAL
MONDAY...THEN SLIGHTLY ABOVE NORMAL TUESDAY AND WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
MID/UPPER-LEVEL HIGH PRESSURE OVER THE ATLANTIC TO EDGE WESTWARD AND
EXERT MORE INFLUENCE ON THE AREA THURSDAY INTO FRIDAY BEFORE
WEAKENING TOWARD THE END OF THE WEEK AS A TROUGH SHIFTS OFFSHORE TO
THE NORTH. THIS FEATURE WILL PUSH A COLD FRONT TOWARD THE AREA
ALTHOUGH CLIMATOLOGY WOULD SUGGEST IT WILL REMAIN TO THE NORTH.
FAVORABLE SYNOPTIC LIFT AND DEEPER MOISTURE ALONG WITH THE SURFACE
FRONT AND AREAS OF LOW PRESSURE ALONG IT WILL CREATE MORE FAVORABLE
CONDITIONS FOR SHOWERS AND THUNDERSTORMS FRIDAY THROUGH THE WEEKEND.
PRECIPITABLE WATER VALUES OF AT LEAST 2 INCHES WILL SUPPORT THE
THREAT FOR LOCALIZED HEAVY RAINFALL. TEMPERATURES TO START OUT ABOVE
NORMAL BEFORE FALLING BACK CLOSER TO NORMAL LATER IN THE WEEK AND
OVER THE WEEKEND WITH INCREASED CLOUDS/RAIN.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
VFR FOR THE NEXT 24 HOURS. ISOLATED SHOWERS AND POSSIBLY A TSTM
COULD IMPACT KCHS/KSAV AT JUST ABOUT ANY TIME THROUGH MID-
AFTERNOON...BUT ANY IMPACT DURATIONS SHOULD REMAIN LESS THAN 5-10
MINUTES AT BEST. WILL NOT HIGHLIGHT ANY MENTION OF SHRA OR TSRA AT
EITHER TERMINAL JUST YET BECAUSE OF THIS. LOW CHANCE FOR SHALLOW
GROUND FOG IMPACTING THE TERMINALS EARLY MONDAY.
EXTENDED AVIATION OUTLOOK...THERE ARE NO CONCERNS OF GREATER THAN 30
PERCENT CONFIDENCE.
&&
.MARINE...
WINDS WILL CONTINUE TO BE LIGHT TODAY AND TONIGHT IN THE VICINITY
OF THE SURFACE RIDGE. SUSTAINED WINDS WILL BE LESS THAN 15 KNOTS.
THERE MAY BE A SMALL SWELL OF 2 FEET OR SO IN THE WATERS DUE TO
THE LONG FETCH OF SOUTHEASTERLIES EXTENDING WELL OUT INTO THE
ATLANTIC...BUT THE SURFACE WINDS WILL BE TOO LIGHT TOO ADD MUCH
WIND WAVE INTO THE EQUATION...SO 2 TO 3 FEET NEARSHORE AND 3 TO 4
FEET OFFSHORE LOOK GOOD TODAY.
MONDAY THROUGH FRIDAY...ATLANTIC HIGH PRESSURE TO REMAIN IN CONTROL
THIS PERIOD WITH A WEAK TROPICAL WAVE OF LOW PRESSURE LIKELY
AFFECTING THE AREA MONDAY. THEREAFTER...A SOUTH/SOUTHWESTERLY FLOW
WILL DOMINATE AS A TROUGH OF LOW PRESSURE SETS UP INLAND AND
ATLANTIC HIGH PRESSURE STRENGTHENS OFFSHORE. CONDITIONS SHOULD
REMAIN BELOW ADVISORY LEVELS THROUGH THE PERIOD ALTHOUGH WINDS/SEAS
WILL BE ON THE INCREASE STARTING MID WEEK AS THE PRESSURE GRADIENT
STRENGTHENS BETWEEN THESE TWO SYSTEMS.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...ALSHEIMER/RJB
LONG TERM...RJB
AVIATION...
MARINE...
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
409 AM CDT SUN JUL 15 2012
.DISCUSSION...
837 PM CDT
CONVECTIVE ACTIVITY HAS SETTLED THIS EVENING AND SHOULD BE DRY
THROUGH THE REMAINDER OF THE EVENING. HAVE TWEAKED POPS TO REFLECT
DIMINISHED CHANCES. LATE TONIGHT ANOTHER MID LEVEL DISTURBANCE IS
EXPECTED TO DROP SOUTH ACROSS THE AREA. ISOLATED THUNDERSTORMS
ASSOCIATED WITH THIS WAVE HAVE ALREADY DEVELOPED OVER PORTIONS OF
WISCONSIN...BUT OVERALL FORCING/MOISTURE CONVERGENCE APPEARS TO BE
VERY WEAK AND DO NOT EXPECT MORE THAN ISOLATED COVERAGE IF ANY AS IT
MOVES INTO NORTHERN ILLINOIS. OTHERWISE...ONLY MADE MINOR TWEAKS TO
HOURLY TRENDS FOR T/TD...OVERALL FORECAST APPEARS ON TRACK. BMD
//PREV DISCUSSION...
210 PM CDT
CONCERNS WITH THE FORECAST ARE CENTERED ON CONVECTION THROUGH THIS
EVENING...AND THEN HOT TEMPERATURES THE NEXT SEVERAL DAYS.
SHORT TERM...REST OF THIS AFTERNOON THROUGH SUNDAY...
TOWERING CUMULUS ALONG WITH SOME SCATTERED STORMS HAVE DEVELOPED
EARLY THIS AFTERNOON ACROSS MAINLY THE EASTERN HALF OF THE
FORECAST AREA ALONG AND AHEAD OF A SHEARED OUT UPPER IMPULSE AND
AN ELEVATED /850-700MB/ WIND AND MOISTURE CONVERGENCE ZONE. GIVEN
A FAIRLY UNSTABLE AIR MASS PER MODIFIED AMDAR SOUNDINGS AND RAP
ANALYSIS...WITH MLCAPE VALUES OF 1000 TO 1500 J/KG...THESE STORMS
SHOULD CONTINUE TO REGENERATE WITH THE FURTHER FOCI OF BOUNDARY
INTERACTIONS. HAVE ALREADY SEEN THE DIVERGENT VELOCITY SIGNATURES
ON RADAR UNDERNEATH THESE STORMS WITHIN JUST TWO RADAR
VCPS...SHOWING THE DOWNDRAFT POTENTIAL ONCE AGAIN. ENVIRONMENTAL
DCAPE VALUES ANALYZED BY THE RAP OF 700 TO 1000 J/KG ARE SLIGHTLY
LESS THAN YESTERDAY...BUT SUFFICIENT ENOUGH FOR A POSSIBLE
ISOLATED SEVERE GUST...INCLUDING IN NEARSHORE AREAS OF THE LAKE IN
ANY STORMS THAT DRIFT NORTHEAST OVER THAT AREA.
AN UPPER LEVEL SHORT WAVE...AS PART OF THE LARGER BROAD
TROUGH...IS MOVING SOUTHEAST ACROSS WESTERN WI EARLY THIS
AFTERNOON. THE INITIAL SURFACE BOUNDARY UNDERNEATH THIS IS HELPING
TO FOCUS SOME SCATTERED STORMS...WITH SIMILAR ML INSTABILITY OF
1000 TO 1500 J/KG. MORE DEVELOPMENT IS ANTICIPATED THROUGH EARLY
EVENING IN ADVANCE OF THIS AS CONVERGENCE IMPROVES...AND SOME OF
THIS MAY POTENTIALLY BE ALONG OUTFLOW THAT IS ALREADY INTO
NORTHWEST IL. EXPLICIT CONVECTIVE MODELS DO KEY IN ON SCATTERED
STORM DEVELOPMENT TOWARD THE I-39 CORRIDOR BY LATE AFTERNOON. WITH
THE SHORT WAVE AND FRONTAL APPROACH...ALONG WITH DEEP LAYER SHEAR
VALUES OF SEMI-DECENT 30 KT PROJECTED...THESE SHOWERS AND
STORMS HAVE POTENTIAL TO HANG ON LATER INTO THE EVENING.
THE COOL FRONT WILL MOVE THROUGH THE AREA LATE TONIGHT AND SUNDAY
MORNING...BUT WASHING OUT AS IT DOES. TEMPERATURES ON SUNDAY ARE
ACTUALLY EXPECTED TO BE SLIGHTLY HIGHER THAN TODAY...AND DEW
POINTS SHOULD BE CLOSE. THIS WILL AGAIN PROVIDE MODEST
INSTABILITY...BUT HEIGHT RISES ALOFT SHOULD TEMPER STORM
DEVELOPMENT. A ROGUE LATE AFTERNOON CELL OR TWO CANNOT BE RULED
OUT ALONG WEAK SURFACE CONVERGENCE...BUT HAVE NOT MENTIONED IN THE
FORECAST AT THIS TIME. HIGHS ON SUNDAY LOOK TO TOP OUT IN THE
LOWER TO MID 90S...WITH A LAKE BREEZE PROVIDING SOME COOLING FOR
DOWNTOWN CHICAGO AND NEARBY AREAS DURING THE AFTERNOON. THESE LAKE
SHORE AREAS STILL MAY REACH 90 OR NEAR IT BEFORE THE LAKE BREEZE
PUSHES THROUGH.
MTF
LONG TERM...SUNDAY NIGHT THROUGH SATURDAY...
THE UPPER LEVEL RIDGE REESTABLISHES ITSELF ACROSS THE CENTRAL US AS
THE TROUGH MOVES OFF TOWARD THE NEW ENGLAND AREA. A WEAKENING AREA
OF LOW PRESSURE MOVES NORTH OF THE GREAT LAKES MONDAY NIGHT...WHILE
ITS COLD FRONT SINKS SOUTH DOWN THE LAKE ON TUESDAY.
PRECIP CHANCES DIMINISH AS THE TROUGH DRIFTS EASTWARD SUNDAY NIGHT.
THE BEST CHANCE OF PRECIP IN THE EXTENDED IS ALONG THE COLD FRONT
LATE TUESDAY THROUGH WEDNESDAY. GUIDANCE DIFFERS ON THE SPEED OF
THE FRONT...WITH THE GFS BRINGING THE FRONT THROUGH MUCH FASTER THAN
THE ECMWF. GIVEN ISSUES WITH THE GFS LATELY...AND THE ECMWF HAVING
VERY CONSISTENT TIMING OVER THE PAST FEW DAYS...GOING WITH THE
SLOWER SOLUTION. BOTH MODELS INDICATE MOISTURE WILL POOL ALONG THE
FRONT...BUT THEN DISSIPATE AS THE FRONT ENTERS NORTHERN IL.
THEREFORE...KEPT BEST PRECIP CHANCES NORTH OF I-80. LIMITED ACTUAL
PRECIP CHANCES TO LESS THAN 50 PERCENT GIVEN THE MODEL TRENDS AND
DRY CONDITIONS.
HIGH PRESSURE BUILDS IN BEHIND THE FRONT...AND GUIDANCE SUGGESTS
RANDOM PERIODS OF PRECIP DURING THE LATTER HALF OF NEXT WEEK.
HOWEVER...WITH NO CLEAR SOURCE OF FORCING...QUESTIONABLE MOISTURE
SOURCES...AND DROUGHT CONDITIONS...DECIDED TO KEEP THE REMAINDER OF
THE EXTENDED DRY. AT THIS POINT THE BIGGER CRIME IS GETTING FOLKS
HOPES UP FOR RAIN ONLY TO DISAPPOINT.
HEAT BUILDS ACROSS THE REGION THROUGH TUESDAY. GUIDANCE SUGGESTS
THERE WILL ONLY BE A SMALL PUSH OF SLIGHTLY COOLER AIR BEHIND THE
FRONT...WITH WEDNESDAY LOOKING TO BE A BIT COOLER. HOWEVER 850 HPA
TEMPS BEGIN TO WARM ALMOST IMMEDIATELY WITH THE UPPER LEVEL RIDGE SW
OF THE CWA. THEREFORE...THE LATTER HALF OF NEXT WEEK LOOKS ABOVE
AVERAGE.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* LIGHT SOUTH WIND BECOMING SOUTHWEST OVERNIGHT.
* VERY LOW PROBABILITY SHRA/TSRA POTENTIAL THROUGH MID MORNING.
* WIND SHIFT FROM LIGHT WEST-SOUTHWEST TO EAST-NORTHEAST WITH WEAK
TROUGH PASSAGE MID-LATE MORNING AND LAKE BREEZE PUSH FROM THE
EAST THIS AFTERNOON.
MDB
//DISCUSSION...UPDATED 09Z...
WEAK UPPER TROUGH/WEAK SURFACE FRONT CONTINUE TO APPROACH THE AREA
FROM THE NORTHWEST. EARLIER SPOTTY CONVECTION ASSOCIATED WITH IT
ACROSS CENTRAL/SOUTHERN WISCONSIN HAS DISSIPATED WITH LITTLE IN
THE WAY OF CLOUD COVER BEING GENERATED BY THE WAVE AT THIS TIME.
STILL EXPECT THAT THE TERMINALS WILL REMAIN DRY AS THESE FEATURES
PASS BUT A NON-ZERO CHANCE FOR SOME ISOLATED DEVELOPMENT DOES
EXIST BUT IS TOO LOW TO INCLUDE MENTION IN THE TAFS.
MDB
FROM 06Z...
THE MAIN FORECAST CONCERNS ARE SLIM CHANCES FOR ISOLD SHRA/TSRA
THROUGH DAYBREAK...AN OFF CHANCE THIS AFTERNOON...AND A LAKE
BREEZE PUSHING INLAND DURING THE AFTERNOON. SATELLITE IMAGERY
CONTINUES TO SHOW AN UPPER LEVEL TROUGH MOVING SOUTHEASTWARD
ACROSS CENTRAL/SOUTHERN WISCONSIN EARLY TONIGHT. RADAR CONTINUES
TO SHOW SOME SHRA/TSRA ACTIVITY AHEAD OF THIS WAVE ACROSS SOUTHERN
WI BUT LATEST IMAGERY SHOWS A WEAKENING TREND TO THIS ACTIVITY.
ENERGY ASSOCIATED WITH THE SHORTWAVE WILL REACH THE AREA IN THE
NEXT 2-3 HOURS OR SO AND BRING A VERY LOW CHANCE FOR KICKING OFF
SHRA/TSRA AS IT DOES SO. WILL CONTINUE TO LEAVE ANY PRECIP MENTION
OUT OF THE TAFS WITH THE CHANCE FOR OCCURRENCE TOO LOW. SHOULD
ANYTHING MAKE IT INTO NORTHERN ILLINOIS/NW INDIANA IT WOULD BE
VERY ISOLATED. IN ADDITION...A WEAK SURFACE TROUGH WILL BE
SETTLING ACROSS THE AREA LATER THIS MORNING. THIS MAY ALSO SERVE
AS A FOCUS FOR SHRA/TSRA DEVELOPMENT DURING THE MID/LATE MORNING
HOURS BUT THIS CHANCE IS ALSO VERY LOW.
LIGHT WINDS FAVORING A SOUTHWESTERLY DIRECTION WILL TURN NORTHERLY
AS THE SURFACE TROUGH PASSES MID/LATE MORNING. THE FLOW WILL
REMAIN WEAK WHICH WILL SUPPORT THE DEVELOPMENT OF A LAKE BREEZE
WHICH SHOULD MOVE FAIRLY FAR INLAND THIS AFTERNOON. WINDS WILL
TURN EAST TO NORTHEAST AS THE LAKE BREEZE BOUNDARY PASSES. IT IS
POSSIBLE THAT THE LAKE BREEZE COULD AID SOME SPOTTY TSRA
DEVELOPMENT THIS AFTERNOON BUT WARMING OF THE MID LEVELS SHOULD
PRECLUDE MUCH OF NOT ALL DEVELOPMENT THIS AFTERNOON.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* HIGH CONFIDENCE IN OVERALL WIND TRENDS.
* MEDIUM-HIGH CONFIDENCE IN NO ADDITIONAL TSRA AT TERMINALS.
* HIGH CONFIDENCE IN LAKE BREEZE OCCURRENCE THIS AFTERNOON.
MDB
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...VFR.
TUESDAY...VFR. CHANCE TSRA TUES NGT.
WEDNESDAY...SLGT CHANCE TSRA. OTHERWISE VFR.
THURSDAY AND FRIDAY...VFR.
RATZER
&&
.MARINE...
246 AM CDT
A SERIES OF SYSTEMS WILL PASS NORTH OF LAKE MICHIGAN BETWEEN NOW AND
WEDNESDAY...EACH BRINGING A COOL FRONTAL BOUNDARY DOWN THE LAKE. THE
FIRST AREA OF LOW PRESSURE IS MOVING ACROSS EASTERN ONTARIO AND
EXTENDS TOWARD NORTHERN LAKE MICHIGAN. A WEAK FRONT CONTINUES TO
DROP SOUTHWARD DOWN THE LAKE AND WILL BE TO THE SOUTH BY LATE
MORNING. HIGH PRESSURE THEN QUICKLY RETURNS BEHIND THE FRONT THIS
AFTERNOON. WINDS WILL LIKELY BECOME LIGHT AND VARIABLE OR ONSHORE
ACROSS MUCH OF THE CENTRAL AND SOUTHERN PART OF THE LAKE THIS
AFTERNOON THEN BECOME SOUTHERLY ACROSS THE LAKE THIS EVENING.
ANOTHER LOW PRESSURE SYSTEM TAKES SHAPE ACROSS THE DAKOTAS AND
TURNS EASTWARD AND CROSSES LAKE SUPERIOR MONDAY EVENING. THIS LOW
IS EXPECTED TO BE FAIRLY WELL ORGANIZED AND TIGHTENS THE PRESSURE
GRADIENT ACROSS THE NORTHERN END OF THE LAKE LEADING TO A PERIOD
OF 25-30 KT WINDS LATE MONDAY AFTERNOON AND MONDAY EVENING. AS THE
LOW EXITS INTO SOUTHERN QUEBEC TUESDAY A COLD FRONT WILL MARCH
DOWN THE LAKE BRINGING A SHIFT FROM BREEZY SOUTHERLY WINDS TO
BREEZY NORTHWESTERLY WINDS. AT THIS POINT...SPEEDS ON THE BACK
SIDE OF THE FRONT LOOK TO BE MODESTLY LOWER THAN THE WINDS AHEAD
OF THE FRONT. WILL NEED TO WATCH FOR SMALL CRAFT ADVISORY
CONDITIONS FROM WEDNESDAY AFTERNOON BUT AT THIS POINT IT SEEMS
THAT CRITERIA WILL NOT BE MET...HOWEVER...THE LONG FETCH IN PLACE
BEHIND THIS FRONT MAY ALLOW WAVES TO BUILD ENOUGH TO WARRANT
ISSUANCE. HIGH PRESSURE THEN BUILDS IN WEDNESDAY NIGHT AND DRIFTS
EASTWARD ACROSS MICHIGAN INTO FRIDAY NIGHT. ONCE THE STRONGER
NORTH TO NORTHEAST WINDS DIMINISH WEDNESDAY NIGHT LIGHTER WINDS
WILL RETURN AND FAVOR AN EAST TO SOUTHEAST DIRECTION INTO EARLY
SATURDAY WITH A PERIOD OF MORE ONSHORE WINDS FRIDAY WITH A LIGHTER
SYNOPTIC SCALE FLOW SUPPORTING LAKE BREEZE DEVELOPMENT.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
254 AM CDT SUN JUL 15 2012
.DISCUSSION...
837 PM CDT
CONVECTIVE ACTIVITY HAS SETTLED THIS EVENING AND SHOULD BE DRY
THROUGH THE REMAINDER OF THE EVENING. HAVE TWEAKED POPS TO REFLECT
DIMINISHED CHANCES. LATE TONIGHT ANOTHER MID LEVEL DISTURBANCE IS
EXPECTED TO DROP SOUTH ACROSS THE AREA. ISOLATED THUNDERSTORMS
ASSOCIATED WITH THIS WAVE HAVE ALREADY DEVELOPED OVER PORTIONS OF
WISCONSIN...BUT OVERALL FORCING/MOISTURE CONVERGENCE APPEARS TO BE
VERY WEAK AND DO NOT EXPECT MORE THAN ISOLATED COVERAGE IF ANY AS IT
MOVES INTO NORTHERN ILLINOIS. OTHERWISE...ONLY MADE MINOR TWEAKS TO
HOURLY TRENDS FOR T/TD...OVERALL FORECAST APPEARS ON TRACK. BMD
//PREV DISCUSSION...
210 PM CDT
CONCERNS WITH THE FORECAST ARE CENTERED ON CONVECTION THROUGH THIS
EVENING...AND THEN HOT TEMPERATURES THE NEXT SEVERAL DAYS.
SHORT TERM...REST OF THIS AFTERNOON THROUGH SUNDAY...
TOWERING CUMULUS ALONG WITH SOME SCATTERED STORMS HAVE DEVELOPED
EARLY THIS AFTERNOON ACROSS MAINLY THE EASTERN HALF OF THE
FORECAST AREA ALONG AND AHEAD OF A SHEARED OUT UPPER IMPULSE AND
AN ELEVATED /850-700MB/ WIND AND MOISTURE CONVERGENCE ZONE. GIVEN
A FAIRLY UNSTABLE AIR MASS PER MODIFIED AMDAR SOUNDINGS AND RAP
ANALYSIS...WITH MLCAPE VALUES OF 1000 TO 1500 J/KG...THESE STORMS
SHOULD CONTINUE TO REGENERATE WITH THE FURTHER FOCI OF BOUNDARY
INTERACTIONS. HAVE ALREADY SEEN THE DIVERGENT VELOCITY SIGNATURES
ON RADAR UNDERNEATH THESE STORMS WITHIN JUST TWO RADAR
VCPS...SHOWING THE DOWNDRAFT POTENTIAL ONCE AGAIN. ENVIRONMENTAL
DCAPE VALUES ANALYZED BY THE RAP OF 700 TO 1000 J/KG ARE SLIGHTLY
LESS THAN YESTERDAY...BUT SUFFICIENT ENOUGH FOR A POSSIBLE
ISOLATED SEVERE GUST...INCLUDING IN NEARSHORE AREAS OF THE LAKE IN
ANY STORMS THAT DRIFT NORTHEAST OVER THAT AREA.
AN UPPER LEVEL SHORT WAVE...AS PART OF THE LARGER BROAD
TROUGH...IS MOVING SOUTHEAST ACROSS WESTERN WI EARLY THIS
AFTERNOON. THE INITIAL SURFACE BOUNDARY UNDERNEATH THIS IS HELPING
TO FOCUS SOME SCATTERED STORMS...WITH SIMILAR ML INSTABILITY OF
1000 TO 1500 J/KG. MORE DEVELOPMENT IS ANTICIPATED THROUGH EARLY
EVENING IN ADVANCE OF THIS AS CONVERGENCE IMPROVES...AND SOME OF
THIS MAY POTENTIALLY BE ALONG OUTFLOW THAT IS ALREADY INTO
NORTHWEST IL. EXPLICIT CONVECTIVE MODELS DO KEY IN ON SCATTERED
STORM DEVELOPMENT TOWARD THE I-39 CORRIDOR BY LATE AFTERNOON. WITH
THE SHORT WAVE AND FRONTAL APPROACH...ALONG WITH DEEP LAYER SHEAR
VALUES OF SEMI-DECENT 30 KT PROJECTED...THESE SHOWERS AND
STORMS HAVE POTENTIAL TO HANG ON LATER INTO THE EVENING.
THE COOL FRONT WILL MOVE THROUGH THE AREA LATE TONIGHT AND SUNDAY
MORNING...BUT WASHING OUT AS IT DOES. TEMPERATURES ON SUNDAY ARE
ACTUALLY EXPECTED TO BE SLIGHTLY HIGHER THAN TODAY...AND DEW
POINTS SHOULD BE CLOSE. THIS WILL AGAIN PROVIDE MODEST
INSTABILITY...BUT HEIGHT RISES ALOFT SHOULD TEMPER STORM
DEVELOPMENT. A ROGUE LATE AFTERNOON CELL OR TWO CANNOT BE RULED
OUT ALONG WEAK SURFACE CONVERGENCE...BUT HAVE NOT MENTIONED IN THE
FORECAST AT THIS TIME. HIGHS ON SUNDAY LOOK TO TOP OUT IN THE
LOWER TO MID 90S...WITH A LAKE BREEZE PROVIDING SOME COOLING FOR
DOWNTOWN CHICAGO AND NEARBY AREAS DURING THE AFTERNOON. THESE LAKE
SHORE AREAS STILL MAY REACH 90 OR NEAR IT BEFORE THE LAKE BREEZE
PUSHES THROUGH.
MTF
LONG TERM...SUNDAY NIGHT THROUGH SATURDAY...
THE UPPER LEVEL RIDGE REESTABLISHES ITSELF ACROSS THE CENTRAL US AS
THE TROUGH MOVES OFF TOWARD THE NEW ENGLAND AREA. A WEAKENING AREA
OF LOW PRESSURE MOVES NORTH OF THE GREAT LAKES MONDAY NIGHT...WHILE
ITS COLD FRONT SINKS SOUTH DOWN THE LAKE ON TUESDAY.
PRECIP CHANCES DIMINISH AS THE TROUGH DRIFTS EASTWARD SUNDAY NIGHT.
THE BEST CHANCE OF PRECIP IN THE EXTENDED IS ALONG THE COLD FRONT
LATE TUESDAY THROUGH WEDNESDAY. GUIDANCE DIFFERS ON THE SPEED OF
THE FRONT...WITH THE GFS BRINGING THE FRONT THROUGH MUCH FASTER THAN
THE ECMWF. GIVEN ISSUES WITH THE GFS LATELY...AND THE ECMWF HAVING
VERY CONSISTENT TIMING OVER THE PAST FEW DAYS...GOING WITH THE
SLOWER SOLUTION. BOTH MODELS INDICATE MOISTURE WILL POOL ALONG THE
FRONT...BUT THEN DISSIPATE AS THE FRONT ENTERS NORTHERN IL.
THEREFORE...KEPT BEST PRECIP CHANCES NORTH OF I-80. LIMITED ACTUAL
PRECIP CHANCES TO LESS THAN 50 PERCENT GIVEN THE MODEL TRENDS AND
DRY CONDITIONS.
HIGH PRESSURE BUILDS IN BEHIND THE FRONT...AND GUIDANCE SUGGESTS
RANDOM PERIODS OF PRECIP DURING THE LATTER HALF OF NEXT WEEK.
HOWEVER...WITH NO CLEAR SOURCE OF FORCING...QUESTIONABLE MOISTURE
SOURCES...AND DROUGHT CONDITIONS...DECIDED TO KEEP THE REMAINDER OF
THE EXTENDED DRY. AT THIS POINT THE BIGGER CRIME IS GETTING FOLKS
HOPES UP FOR RAIN ONLY TO DISAPPOINT.
HEAT BUILDS ACROSS THE REGION THROUGH TUESDAY. GUIDANCE SUGGESTS
THERE WILL ONLY BE A SMALL PUSH OF SLIGHTLY COOLER AIR BEHIND THE
FRONT...WITH WEDNESDAY LOOKING TO BE A BIT COOLER. HOWEVER 850 HPA
TEMPS BEGIN TO WARM ALMOST IMMEDIATELY WITH THE UPPER LEVEL RIDGE SW
OF THE CWA. THEREFORE...THE LATTER HALF OF NEXT WEEK LOOKS ABOVE
AVERAGE.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* LIGHT SOUTH WIND BECOMING SOUTHWEST OVERNIGHT.
* VERY LOW PROBABILITY SHRA/TSRA POTENTIAL LATER TONIGHT INTO
EARLY MORNING.
* WIND SHIFT FROM LIGHT WEST-SOUTHWEST TO EAST-NORTHEAST WITH WEAK
TROUGH PASSAGE MID-LATE MORNING AND LAKE BREEZE PUSH FROM THE
EAST THIS AFTERNOON.
MDB
//DISCUSSION...UPDATED 06Z...
THE MAIN FORECAST CONCERNS ARE SLIM CHANCES FOR ISOLD SHRA/TSRA
THROUGH DAYBREAK...AN OFF CHANCE THIS AFTERNOON...AND A LAKE
BREEZE PUSHING INLAND DURING THE AFTERNOON. SATELLITE IMAGERY
CONTINUES TO SHOW AN UPPER LEVEL TROUGH MOVING SOUTHEASTWARD
ACROSS CENTRAL/SOUTHERN WISCONSIN EARLY TONIGHT. RADAR CONTINUES
TO SHOW SOME SHRA/TSRA ACTIVITY AHEAD OF THIS WAVE ACROSS SOUTHERN
WI BUT LATEST IMAGERY SHOWS A WEAKENING TREND TO THIS ACTIVITY.
ENERGY ASSOCIATED WITH THE SHORTWAVE WILL REACH THE AREA IN THE
NEXT 2-3 HOURS OR SO AND BRING A VERY LOW CHANCE FOR KICKING OFF
SHRA/TSRA AS IT DOES SO. WILL CONTINUE TO LEAVE ANY PRECIP MENTION
OUT OF THE TAFS WITH THE CHANCE FOR OCCURRENCE TOO LOW. SHOULD
ANYTHING MAKE IT INTO NORTHERN ILLINOIS/NW INDIANA IT WOULD BE
VERY ISOLATED. IN ADDITION...A WEAK SURFACE TROUGH WILL BE
SETTLING ACROSS THE AREA LATER THIS MORNING. THIS MAY ALSO SERVE
AS A FOCUS FOR SHRA/TSRA DEVELOPMENT DURING THE MID/LATE MORNING
HOURS BUT THIS CHANCE IS ALSO VERY LOW.
LIGHT WINDS FAVORING A SOUTHWESTERLY DIRECTION WILL TURN NORTHERLY
AS THE SURFACE TROUGH PASSES MID/LATE MORNING. THE FLOW WILL
REMAIN WEAK WHICH WILL SUPPORT THE DEVELOPMENT OF A LAKE BREEZE
WHICH SHOULD MOVE FAIRLY FAR INLAND THIS AFTERNOON. WINDS WILL
TURN EAST TO NORTHEAST AS THE LAKE BREEZE BOUNDARY PASSES. IT IS
POSSIBLE THAT THE LAKE BREEZE COULD AID SOME SPOTTY TSRA
DEVELOPMENT THIS AFTERNOON BUT WARMING OF THE MID LEVELS SHOULD
PRECLUDE MUCH OF NOT ALL DEVELOPMENT THIS AFTERNOON.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN OVERALL WIND TRENDS.
* MEDIUM-HIGH CONFIDENCE IN NO ADDITIONAL TSRA AT TERMINALS.
* HIGH CONFIDENCE IN LAKE BREEZE OCCURRENCE THIS AFTERNOON.
MDB
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...VFR.
TUESDAY...VFR. CHANCE TSRA TUES NGT.
WEDNESDAY...SLGT CHANCE TSRA. OTHERWISE VFR.
THURSDAY AND FRIDAY...VFR.
RATZER
&&
.MARINE...
246 AM CDT
A SERIES OF SYSTEMS WILL PASS NORTH OF LAKE MICHIGAN BETWEEN NOW AND
WEDNESDAY...EACH BRINGING A COOL FRONTAL BOUNDARY DOWN THE LAKE. THE
FIRST AREA OF LOW PRESSURE IS MOVING ACROSS EASTERN ONTARIO AND
EXTENDS TOWARD NORTHERN LAKE MICHIGAN. A WEAK FRONT CONTINUES TO
DROP SOUTHWARD DOWN THE LAKE AND WILL BE TO THE SOUTH BY LATE
MORNING. HIGH PRESSURE THEN QUICKLY RETURNS BEHIND THE FRONT THIS
AFTERNOON. WINDS WILL LIKELY BECOME LIGHT AND VARIABLE OR ONSHORE
ACROSS MUCH OF THE CENTRAL AND SOUTHERN PART OF THE LAKE THIS
AFTERNOON THEN BECOME SOUTHERLY ACROSS THE LAKE THIS EVENING.
ANOTHER LOW PRESSURE SYSTEM TAKES SHAPE ACROSS THE DAKOTAS AND
TURNS EASTWARD AND CROSSES LAKE SUPERIOR MONDAY EVENING. THIS LOW
IS EXPECTED TO BE FAIRLY WELL ORGANIZED AND TIGHTENS THE PRESSURE
GRADIENT ACROSS THE NORTHERN END OF THE LAKE LEADING TO A PERIOD
OF 25-30 KT WINDS LATE MONDAY AFTERNOON AND MONDAY EVENING. AS THE
LOW EXITS INTO SOUTHERN QUEBEC TUESDAY A COLD FRONT WILL MARCH
DOWN THE LAKE BRINGING A SHIFT FROM BREEZY SOUTHERLY WINDS TO
BREEZY NORTHWESTERLY WINDS. AT THIS POINT...SPEEDS ON THE BACK
SIDE OF THE FRONT LOOK TO BE MODESTLY LOWER THAN THE WINDS AHEAD
OF THE FRONT. WILL NEED TO WATCH FOR SMALL CRAFT ADVISORY
CONDITIONS FROM WEDNESDAY AFTERNOON BUT AT THIS POINT IT SEEMS
THAT CRITERIA WILL NOT BE MET...HOWEVER...THE LONG FETCH IN PLACE
BEHIND THIS FRONT MAY ALLOW WAVES TO BUILD ENOUGH TO WARRANT
ISSUANCE. HIGH PRESSURE THEN BUILDS IN WEDNESDAY NIGHT AND DRIFTS
EASTWARD ACROSS MICHIGAN INTO FRIDAY NIGHT. ONCE THE STRONGER
NORTH TO NORTHEAST WINDS DIMINISH WEDNESDAY NIGHT LIGHTER WINDS
WILL RETURN AND FAVOR AN EAST TO SOUTHEAST DIRECTION INTO EARLY
SATURDAY WITH A PERIOD OF MORE ONSHORE WINDS FRIDAY WITH A LIGHTER
SYNOPTIC SCALE FLOW SUPPORTING LAKE BREEZE DEVELOPMENT.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1241 AM CDT SUN JUL 15 2012
.DISCUSSION...
837 PM CDT
CONVECTIVE ACTIVITY HAS SETTLED THIS EVENING AND SHOULD BE DRY
THROUGH THE REMAINDER OF THE EVENING. HAVE TWEAKED POPS TO REFLECT
DIMINISHED CHANCES. LATE TONIGHT ANOTHER MID LEVEL DISTURBANCE IS
EXPECTED TO DROP SOUTH ACROSS THE AREA. ISOLATED THUNDERSTORMS
ASSOCIATED WITH THIS WAVE HAVE ALREADY DEVELOPED OVER PORTIONS OF
WISCONSIN...BUT OVERALL FORCING/MOISTURE CONVERGENCE APPEARS TO BE
VERY WEAK AND DO NOT EXPECT MORE THAN ISOLATED COVERAGE IF ANY AS IT
MOVES INTO NORTHERN ILLINOIS. OTHERWISE...ONLY MADE MINOR TWEAKS TO
HOURLY TRENDS FOR T/TD...OVERALL FORECAST APPEARS ON TRACK. BMD
//PREV DISCUSSION...
210 PM CDT
CONCERNS WITH THE FORECAST ARE CENTERED ON CONVECTION THROUGH THIS
EVENING...AND THEN HOT TEMPERATURES THE NEXT SEVERAL DAYS.
SHORT TERM...REST OF THIS AFTERNOON THROUGH SUNDAY...
TOWERING CUMULUS ALONG WITH SOME SCATTERED STORMS HAVE DEVELOPED
EARLY THIS AFTERNOON ACROSS MAINLY THE EASTERN HALF OF THE
FORECAST AREA ALONG AND AHEAD OF A SHEARED OUT UPPER IMPULSE AND
AN ELEVATED /850-700MB/ WIND AND MOISTURE CONVERGENCE ZONE. GIVEN
A FAIRLY UNSTABLE AIR MASS PER MODIFIED AMDAR SOUNDINGS AND RAP
ANALYSIS...WITH MLCAPE VALUES OF 1000 TO 1500 J/KG...THESE STORMS
SHOULD CONTINUE TO REGENERATE WITH THE FURTHER FOCI OF BOUNDARY
INTERACTIONS. HAVE ALREADY SEEN THE DIVERGENT VELOCITY SIGNATURES
ON RADAR UNDERNEATH THESE STORMS WITHIN JUST TWO RADAR
VCPS...SHOWING THE DOWNDRAFT POTENTIAL ONCE AGAIN. ENVIRONMENTAL
DCAPE VALUES ANALYZED BY THE RAP OF 700 TO 1000 J/KG ARE SLIGHTLY
LESS THAN YESTERDAY...BUT SUFFICIENT ENOUGH FOR A POSSIBLE
ISOLATED SEVERE GUST...INCLUDING IN NEARSHORE AREAS OF THE LAKE IN
ANY STORMS THAT DRIFT NORTHEAST OVER THAT AREA.
AN UPPER LEVEL SHORT WAVE...AS PART OF THE LARGER BROAD
TROUGH...IS MOVING SOUTHEAST ACROSS WESTERN WI EARLY THIS
AFTERNOON. THE INITIAL SURFACE BOUNDARY UNDERNEATH THIS IS HELPING
TO FOCUS SOME SCATTERED STORMS...WITH SIMILAR ML INSTABILITY OF
1000 TO 1500 J/KG. MORE DEVELOPMENT IS ANTICIPATED THROUGH EARLY
EVENING IN ADVANCE OF THIS AS CONVERGENCE IMPROVES...AND SOME OF
THIS MAY POTENTIALLY BE ALONG OUTFLOW THAT IS ALREADY INTO
NORTHWEST IL. EXPLICIT CONVECTIVE MODELS DO KEY IN ON SCATTERED
STORM DEVELOPMENT TOWARD THE I-39 CORRIDOR BY LATE AFTERNOON. WITH
THE SHORT WAVE AND FRONTAL APPROACH...ALONG WITH DEEP LAYER SHEAR
VALUES OF SEMI-DECENT 30 KT PROJECTED...THESE SHOWERS AND
STORMS HAVE POTENTIAL TO HANG ON LATER INTO THE EVENING.
THE COOL FRONT WILL MOVE THROUGH THE AREA LATE TONIGHT AND SUNDAY
MORNING...BUT WASHING OUT AS IT DOES. TEMPERATURES ON SUNDAY ARE
ACTUALLY EXPECTED TO BE SLIGHTLY HIGHER THAN TODAY...AND DEW
POINTS SHOULD BE CLOSE. THIS WILL AGAIN PROVIDE MODEST
INSTABILITY...BUT HEIGHT RISES ALOFT SHOULD TEMPER STORM
DEVELOPMENT. A ROGUE LATE AFTERNOON CELL OR TWO CANNOT BE RULED
OUT ALONG WEAK SURFACE CONVERGENCE...BUT HAVE NOT MENTIONED IN THE
FORECAST AT THIS TIME. HIGHS ON SUNDAY LOOK TO TOP OUT IN THE
LOWER TO MID 90S...WITH A LAKE BREEZE PROVIDING SOME COOLING FOR
DOWNTOWN CHICAGO AND NEARBY AREAS DURING THE AFTERNOON. THESE LAKE
SHORE AREAS STILL MAY REACH 90 OR NEAR IT BEFORE THE LAKE BREEZE
PUSHES THROUGH.
MTF
LONG TERM...SUNDAY NIGHT THROUGH SATURDAY...
THE UPPER LEVEL RIDGE REESTABLISHES ITSELF ACROSS THE CENTRAL US AS
THE TROUGH MOVES OFF TOWARD THE NEW ENGLAND AREA. A WEAKENING AREA
OF LOW PRESSURE MOVES NORTH OF THE GREAT LAKES MONDAY NIGHT...WHILE
ITS COLD FRONT SINKS SOUTH DOWN THE LAKE ON TUESDAY.
PRECIP CHANCES DIMINISH AS THE TROUGH DRIFTS EASTWARD SUNDAY NIGHT.
THE BEST CHANCE OF PRECIP IN THE EXTENDED IS ALONG THE COLD FRONT
LATE TUESDAY THROUGH WEDNESDAY. GUIDANCE DIFFERS ON THE SPEED OF
THE FRONT...WITH THE GFS BRINGING THE FRONT THROUGH MUCH FASTER THAN
THE ECMWF. GIVEN ISSUES WITH THE GFS LATELY...AND THE ECMWF HAVING
VERY CONSISTENT TIMING OVER THE PAST FEW DAYS...GOING WITH THE
SLOWER SOLUTION. BOTH MODELS INDICATE MOISTURE WILL POOL ALONG THE
FRONT...BUT THEN DISSIPATE AS THE FRONT ENTERS NORTHERN IL.
THEREFORE...KEPT BEST PRECIP CHANCES NORTH OF I-80. LIMITED ACTUAL
PRECIP CHANCES TO LESS THAN 50 PERCENT GIVEN THE MODEL TRENDS AND
DRY CONDITIONS.
HIGH PRESSURE BUILDS IN BEHIND THE FRONT...AND GUIDANCE SUGGESTS
RANDOM PERIODS OF PRECIP DURING THE LATTER HALF OF NEXT WEEK.
HOWEVER...WITH NO CLEAR SOURCE OF FORCING...QUESTIONABLE MOISTURE
SOURCES...AND DROUGHT CONDITIONS...DECIDED TO KEEP THE REMAINDER OF
THE EXTENDED DRY. AT THIS POINT THE BIGGER CRIME IS GETTING FOLKS
HOPES UP FOR RAIN ONLY TO DISAPPOINT.
HEAT BUILDS ACROSS THE REGION THROUGH TUESDAY. GUIDANCE SUGGESTS
THERE WILL ONLY BE A SMALL PUSH OF SLIGHTLY COOLER AIR BEHIND THE
FRONT...WITH WEDNESDAY LOOKING TO BE A BIT COOLER. HOWEVER 850 HPA
TEMPS BEGIN TO WARM ALMOST IMMEDIATELY WITH THE UPPER LEVEL RIDGE SW
OF THE CWA. THEREFORE...THE LATTER HALF OF NEXT WEEK LOOKS ABOVE
AVERAGE.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* LIGHT SOUTH WIND BECOMING SOUTHWEST OVERNIGHT.
* VERY LOW PROBABILITY SHRA/TSRA POTENTIAL LATER TONIGHT INTO
EARLY MORNING.
* WIND SHIFT FROM LIGHT WEST-SOUTHWEST TO EAST-NORTHEAST WITH WEAK
TROUGH PASSAGE MID-LATE MORNING AND LAKE BREEZE PUSH FROM THE
EAST THIS AFTERNOON.
MDB
//DISCUSSION...UPDATED 06Z...
THE MAIN FORECAST CONCERNS ARE SLIM CHANCES FOR ISOLD SHRA/TSRA
THROUGH DAYBREAK...AN OFF CHANCE THIS AFTERNOON...AND A LAKE
BREEZE PUSHING INLAND DURING THE AFTERNOON. SATELLITE IMAGERY
CONTINUES TO SHOW AN UPPER LEVEL TROUGH MOVING SOUTHEASTWARD
ACROSS CENTRAL/SOUTHERN WISCONSIN EARLY TONIGHT. RADAR CONTINUES
TO SHOW SOME SHRA/TSRA ACTIVITY AHEAD OF THIS WAVE ACROSS SOUTHERN
WI BUT LATEST IMAGERY SHOWS A WEAKENING TREND TO THIS ACTIVITY.
ENERGY ASSOCIATED WITH THE SHORTWAVE WILL REACH THE AREA IN THE
NEXT 2-3 HOURS OR SO AND BRING A VERY LOW CHANCE FOR KICKING OFF
SHRA/TSRA AS IT DOES SO. WILL CONTINUE TO LEAVE ANY PRECIP MENTION
OUT OF THE TAFS WITH THE CHANCE FOR OCCURRENCE TOO LOW. SHOULD
ANYTHING MAKE IT INTO NORTHERN ILLINOIS/NW INDIANA IT WOULD BE
VERY ISOLATED. IN ADDITION...A WEAK SURFACE TROUGH WILL BE
SETTLING ACROSS THE AREA LATER THIS MORNING. THIS MAY ALSO SERVE
AS A FOCUS FOR SHRA/TSRA DEVELOPMENT DURING THE MID/LATE MORNING
HOURS BUT THIS CHANCE IS ALSO VERY LOW.
LIGHT WINDS FAVORING A SOUTHWESTERLY DIRECTION WILL TURN NORTHERLY
AS THE SURFACE TROUGH PASSES MID/LATE MORNING. THE FLOW WILL
REMAIN WEAK WHICH WILL SUPPORT THE DEVELOPMENT OF A LAKE BREEZE
WHICH SHOULD MOVE FAIRLY FAR INLAND THIS AFTERNOON. WINDS WILL
TURN EAST TO NORTHEAST AS THE LAKE BREEZE BOUNDARY PASSES. IT IS
POSSIBLE THAT THE LAKE BREEZE COULD AID SOME SPOTTY TSRA
DEVELOPMENT THIS AFTERNOON BUT WARMING OF THE MID LEVELS SHOULD
PRECLUDE MUCH OF NOT ALL DEVELOPMENT THIS AFTERNOON.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN OVERALL WIND TRENDS.
* MEDIUM-HIGH CONFIDENCE IN NO ADDITIONAL TSRA AT TERMINALS.
* HIGH CONFIDENCE IN LAKE BREEZE OCCURRENCE THIS AFTERNOON.
MDB
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...VFR.
TUESDAY...VFR. CHANCE TSRA TUES NGT.
WEDNESDAY...SLGT CHANCE TSRA. OTHERWISE VFR.
THURSDAY AND FRIDAY...VFR.
RATZER
&&
.MARINE...
145 PM CDT
LOW PRESSURE ACROSS LAKE SUPERIOR WILL CONTINUE TO MOVE EAST
THROUGH SUNDAY. THIS WILL STEER A COOL FRONT ACROSS THE LAKE LATE
TONIGHT. AHEAD OF THIS WILL BE SOME SCATTERED STORMS...SOME OF
WHICH ARE LIKELY TO BE GUSTY BASED ON THE ENVIRONMENT. THESE WILL
BE MOST FAVORED ACROSS THE SOUTHERN THIRD OF THE LAKE INCLUDING
NEAR SHORE AREAS OF IL...IN...AND SOUTHWEST MI. WINDS BEHIND THE
FRONT ON SUNDAY WILL BECOME LIGHT AND BEGIN TURNING BACK TO
SOUTHERLY ALREADY BY AFTERNOON. SOUTHWEST WINDS WILL INCREASE ON
MON...WITH OPEN WATER LOCATIONS ACROSS THE NORTH LIKELY REACHING
30 KT DURING MON NIGHT. A COOL FRONT WILL SLOWLY WORK SOUTH
ACROSS THE LAKE ON TUESDAY AND TUESDAY NIGHT. THIS WILL SHIFT
WINDS TO THE NORTH AND PROVIDE A FOCUS FOR SCATTERED THUNDERSTORMS
ONCE AGAIN.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1120 PM CDT SAT JUL 14 2012
.DISCUSSION...
ISSUED 825 PM CDT SAT JUL 14 2012
CONVECTION CONTINUES TO DISSIPATE EARLY THIS EVENING WITH SEVERAL
LOCATIONS RECEIVING SOME DECENT RAINFALL FOR A CHANGE. PEORIA...
BLOOMINGTON AND THE NWS AT LINCOLN RECEIVED OVER 1 INCH OF RAIN.
SOME GUSTY WINDS AND SMALL HAIL WERE ASSOCIATED WITH THE STRONGEST
UPDRAFTS...BUT THOSE WERE FEW AND FAR BETWEEN. LATEST SATELLITE
DATA INDICATES THE 500 MB TROF AXIS RIGHT OVER THE FORECAST
AREA EARLY THIS EVENING. THERE WAS ANOTHER WEAK SHORTWAVE SEEN
OVER NW IL AND THAT WAS DRIFTING ESE AND MAY KEEP AT LEAST ISOLATED
SHOWERS GOING INTO THE OVERNIGHT HOURS. AREAS THAT DID RECEIVE THE
RAINFALL TODAY WILL SEE SOME FOG DEVELOP LATER TONIGHT. CURRENT
ZONE FORECAST HAS A GOOD HANDLE ON THE TRENDS THIS EVENING SO
OTHER THAN THE USUAL TWEAKS WITH THE HOURLY TEMPS...NO OTHER CHANGES
WERE MADE. AS A RESULT...NO ZONE UPDATE WILL BE NEEDED EARLY THIS
EVENING.
&&
.AVIATION...
ISSUED 1115 PM CDT SAT JUL 14 2012
FOG DEVELOPMENT AND COVERAGE DURING THE EARLY MORNING HOURS THE
MAIN FORECAST CONCERN.
ALL THE STORMS HAVE DISSIPATED LEAVING MAINLY CLEAR SKIES AND
LIGHT WINDS WHICH SHOULD LEAD TO FOG DEVELOPMENT...ESPECIALLY IN
THE AREAS THAT RECEIVED THE RAIN OVER THE PAST 24 HOURS. THAT
WOULD INCLUDE PIA...BMI AND CMI. DECATUR DID RECEIVE SOME VERY
LIGHT AMOUNTS SO WILL INCLUDE SOME BRIEF MVFR VSBYS STARTING AT
09Z. FURTHER NORTH...MVFR AND POSSIBLY SOME BRIEF IFR VSBYS
STARTING AT 09Z. WHAT FOG WE DO SEE OVERNIGHT SHOULD QUICKLY
DISSPATE SUNDAY MORNING BY 13 OR 14Z FOLLOWED BY A RAPID INCREASE
IN CUMULUS AFTR 16Z. FORECAST SOUNDINGS SUGGEST THERE SHOULD BE
ENOUGH DRY AIR MIX DOWN TO KEEP CLOUDS SCATTERED BUT THAT WILL
HAVE TO BE WATCHED...ESPECIALLY AT BMI AND CMI. CLOUD BASES WILL
RANGE FROM 4000-5000 FEET BY LATE MORNING WITH THE CUMULUS FIELD
DISSIPATING QUICKLY BY 00Z. SFC WINDS WILL BE LIGHT SOUTHERLY
TONIGHT AND SSW AT 10 KTS OR LESS ON SUNDAY/SUNDAY EVENING.
SMITH
&&
.PREV DISCUSSION...
ISSUED 236 PM CDT SAT JUL 14 2012
SCATTERED SHOWERS ACROSS CENTRAL ILLINOIS CONTINUE...WITH VERY
LITTLE MOVEMENT UNDER A WEAK UPPER LEVEL TROF. CONVECTIVE ACTIVITY
TO THE NW THIS MORNING SHOWING UP AS A LITTLE WEAK VORTEX ON VIS
SAT IMAGERY THIS AFTERNOON. BECAUSE OF THAT...HAVE MADE A COUPLE
OF CHANGES TO THE POPS FOR THE OVERNIGHT. OTHER THAN
THAT...FORECAST IS MOSTLY DRY BEYOND TONIGHT. NEXT CHANCE FOR
PRECIP COMES MID WEEK NEXT WEEK. ECMWF NOW HAVING SIMILAR ISSUE TO
THE LAST FEW RUNS OF THE GFS...SO KEEP SCALING BACK THE EXTENDED
POPS
SHORT TERM...TONIGHT AND TOMORROW...
FIRST CONCERN IS THE SMALL VORTEX TO THE NW MOVING NEAR THE REGION
IN THE OVERNIGHT. NEITHER HRRR NOR THE 4KM WRF ARE PICKING UP ON
THE SYSTEM...BUT THE AVAILABLE MOISTURE HAS NOW BEEN A BIT
ALTERED... PARTICULARLY IN THE EASTERN HALF OF THE CWA. FEEL LESS
LIKE THE SHOWERS AFTER 00Z WILL BE LIMITED TO REMNANTS FROM
TODAY...AND HAVE EXPANDED THE CHANCE POPS TO COVER THE ENTIRE
OVERNIGHT. IN ANY SPOTS THAT CLEAR OUT IN THE
OVERNIGHT...PARTICULARLY IN THE EAST WHERE THE BOUNDARY LAYER
MOISTURE HAS BEEN SIGNIF INCREASED BY THE SHOWERS AND
THUNDERSTORMS THIS AFTERNOON...PATCHY FOG WILL BE POSSIBLE IN THE
EARLY MORNING...AND HAVE PLACED THE MENTION IN THE GRIDS FOR A
COUPLE HOURS... MAINLY EAST OF I-55. TOMORROW...IN THE WAKE OF
EXITING SHOWERS...SOME SMALL POPS MOSTLY SOUTH OF INTERSTATE 70.
THESE POPS ARE MOSTLY A PRODUCT OF PREVIOUS MODEL SOLUTIONS WITH
THE ACTIVITY IN THE OHIO RIVER VALLEY. WILL KEEP THEM IN FOR ANY
LINGERING OVERNIGHT PRECIP...BUT MOSTLY REFLECTIVE OF EARLY IN THE
DAY.
LONG TERM...MONDAY THROUGH FRIDAY...
SCATTERED PRECIP THIS AFTERNOON WILL DO LITTLE TO ALLEVIATE THE
DROUGHT OVER THE REGION... PARTICULARLY WITH THE RIDGE BUILDING IN
THE WESTERN CONUS YET AGAIN...AND PUSHING 850MB TEMPS UP AND SFC
TEMPS BACK INTO THE MID-UPPER 90S. DRY WEATHER CONTINUES...HAVE
RAISED MAX TEMPS A DEGREE OR TWO OVER GUIDANCE SINCE MODELS KEEP
PRECIP AND CLOUD COVER IN ABSENCE OF REAL MOISTURE. BEST CHANCES FOR
PRECIP IN EXTENDED COME WITH WED NIGHT AND A PASSING TROF/SFC
BOUNDARY AS AN UPPER WAVE RIPPLES THROUGH THE 500MB FLOW ALONG THE
US/CAN BORDER. THIS FAR SOUTH...AVAILABLE MOISTURE WILL BE
QUESTIONABLE...AS WILL THE AMOUNT OF SFC CONVERGENCE. HAVE PULLED
BACK THE BLENDED POPS WHEREVER POSSIBLE. SCT SHOWER ACTIVITY IS
ALL THAT IS LIKELY IN THIS FORECAST...A VERY SMALL PERCENTAGE OF
AREA WILL SEE THE PRECIP.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
147 AM EDT SUN JUL 15 2012
.AVIATION.../06Z TAFS/
LIGHT SW FLOW OVER THE AREA THIS MORNING WITH MOIST AIRMASS IN
PLACE. THIS MAY ALLOW SOME MVFR VSBYS IN BR TO DVLP OVERNIGHT.
REMAINDER OF THE FCST SHOULD SEE VFR CONDITIONS. CONSIDERABLE
DIURNAL CU EXPECTED TODAY... ESPECIALLY AT FWA. MODERATE
INSTABILITY SHOULD DEVELOP ONCE AGAIN BUT WK FORCING ASSOCIATED
WITH SHRTWV MOVG ACROSS THE GRTLKS SUGGESTS LITTLE CHC OF TSTMS
AT THE TERMINALS. SKIES EXPECTED TO CLEAR THIS EVENING AND WINDS
DIMINISH AS A RIDGE OF HIGH PRESSURE MOVES INTO THE AREA.
&&
.PREV DISCUSSION... /ISSUED 311 PM EDT SAT JUL 14 2012/
SHORT TERM...
OTHER THAN BAND OF ISOLD CONVN FORMING ALG NRN EDGE OF SUB-TROPICAL
MSTR PLUME THIS AFTN...ATTN FOCUSED ON SLW EWD PROGRESSION OF MCV
OVR NE IL EMBEDDED WITHIN LARGER SCALE TROUGHING ANCHORED BY POTENT
SW SEEN IN VAPOR OVR NE MN. TAIL END OF IL MCV ACTIVELY CONVG
THROUGH E/NE IL ATTM WITHIN AXIS OF STG SFC BASED
HEATING/DESTABILIZATION. SHRT TERM RUC SOLUTIONS CARRY ORGANIZING
CLUSTER FM KMDW - S OF KIKK E/NEWD THROUGH NWRN CWA LT THIS
AFTN/EVE AND HAVE GENERALLY BOUGHT INTO ITS SOLUTION...DROPPING
POP/WX MENTION AFT 03Z.
OTHERWISE NRN STREAM SW TROUGH AND ASSOCD SFC TROUGH WILL BUCK EWD
THIS PD W/UNFVRBL TIMING SUN AFTN AND PER GENERAL WKNG OF UPR TROUGH
AND POORLY ALIGNED LL FLW SWD THROUGH THE OH VALLEY...MEASURABLE
PCPN CHCS APPEAR SLIM AND FIT IN CONTEXT OF HIGHRES INDICATIONS OF
AT BEST ISOLD AFTN DVLPMNT OVR FAR ERN/SERN AREAS. THUS PER THE
PREPONDERANCE OF MODEL BASED GUIDANCE WILL CHOP CONSIDERABLY AND
CONFINED TO SUN AFTN PD ALONE. TEMPS CONTD WELL ABV NORMAL THROUGH
THE PD.
LONG TERM...MONDAY THROUGH SATURDAY
MID LEVEL HEIGHTS TO BUILD ACROSS THE SOUTHERN GREAT LAKES REGION ON
MONDAY AS VORT FILAMENT CONTINUES TO GET ELONGATED AND WEAKEN FROM
NEW ENGLAND INTO THE MID MS RIVER VALLEY. MEANWHILE...UPPER LOW
WHICH HAS BEEN DIVORCED FROM MAIN WESTERLIES ACROSS THE PACIFIC
NORTHWEST WILL EVENTUALLY GET ABSORBED BY A STRONGER PV ANOMALY
DROPPING SOUTHWARD ACROSS BC CANADA. SEVERAL WEAK DISTURBANCES WILL
EJECT EASTWARD FROM THIS PV ANOMALY ACROSS FAR SOUTHERN CANADA/GREAT
LAKES REGION INTO TUESDAY...THROUGH THE BASE OF HUDSON BAY UPPER
LEVEL TROUGH. THIS WILL EVENTUALLY ALLOW A COOL FRONT TO DROP
SOUTHWARD ACROSS THE SOUTHERN GREAT LAKES TUESDAY NIGHT INTO
WEDNESDAY. IN THE MEANTIME...STRONGER WEST/SOUTHWEST LOW LEVEL FLOW
BETWEEN LOW LEVEL TROUGHING TO THE NORTHWEST AND SOUTHEAST CONUS
ANTICYCLONE. THIS WILL ALLOW A WEST TO EAST ORIENTED LOW LEVEL
THERMAL RIDGE TO ADVECT EASTWARD IN ADVANCE OF THE COOL FRONT
MONDAY/TUESDAY. MORE FAVORABLE LOW LEVEL THERMAL RIDGE POSITIONING
ON TUESDAY SHOULD MAKE THIS THE HOTTEST DAY OF THE PERIOD...ALTHOUGH
WILDCARD WILL BE POTENTIAL OF SOME CIRRUS BLOWOFF FROM UPSTREAM
CONVECTION. COMPLICATING THE TEMPERATURE FORECAST THIS PERIOD ARE
LARGE DIFFERENCES IN GUIDANCE THERMODYNAMIC PROFILES. 12Z NAM
SUGGESTS MIXING UP TO ABOUT 725 HPA TUESDAY AFTERNOON WHILE GFS IS
MOISTER AND MUCH MORE SHALLOW WITH MIXING. HAVE GENERALLY DISCOUNTED
GFS IDEA WITH MOIST LOW LEVEL BIAS AS OF LATE...WITH MORE WEIGHT TO
THE DEEPER MIXED NAM...ALTHOUGH THIS SOLUTION MAY BE TOO WELL MIXED.
THIS LARGELY SUPPORTS GOING HIGHS IN THE MID TO UPPER 90S AND HAVE
SLIGHTLY ADJUSTED PREVIOUS FORECAST UPWARD...ALTHOUGH POTENTIAL
AFOREMENTIONED HIGH CLOUD ISSUES WILL NEED TO BE CONSIDERED. MAY
NEED TO CONSIDER HEAT HEADLINES EVENTUALLY FOR TUESDAY WITH HEAT
INDICES AROUND 100 EXPECTED.
NO SIGNIFICANT CHANGES MADE TO LOW CHANCE TSRA POPS LATE TUESDAY
NIGHT ACROSS THE NORTH...EXPANDING ACROSS REMAINDER OF FORECAST AREA
WEDNESDAY WITH THE FRONT. LIMITING FACTORS FOR ORGANIZED CONVECTION
ARE MORE SUBSTANTIAL SHEAR PROFILES WELL BEHIND THE FRONT...LIMITED
MID LEVEL LAPSE RATES...AND STRONGER UPPER FORCING TRACKING ACROSS
THE NORTHERN GREAT LAKES. COOLER CONDITIONS FOR THURSDAY AND FRIDAY
BEHIND THE FRONT...ALTHOUGH IT APPEARS HEAT WILL RETURN AS UPPER
RIDGING BUILDS BACK INTO THE AREA JUST BEYOND THIS FORECAST PERIOD.
LOCAL AREA COULD BE PRONE TO CONVECTIVE CHANCES IN ADVANCE OF THIS
BUILDING RIDGE TOWARD THE END OF THE PERIOD...BUT CONFIDENCE MUCH TO
LOW TO INCLUDE IN ONGOING VERY DRY PATTERN.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...T
LONG TERM...MARSILI
AVIATION...JT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1217 AM CDT SUN JUL 15 2012
...UPDATED SYNOPSIS AND AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 1209 AM CDT SUN JUL 15 2012
AT 00Z SUNDAY A 500MB HIGH WAS CENTERED OVER SOUTHEAST COLORADO
AND NORTHEAST NEW MEXICO AND AN UPPER LEVEL RIDGE AXIS EXTENDED
NORTH NORTHEAST INTO NORTH DAKOTA. AN UPPER LEVEL TROUGH WAS
POSITIONED ACROSS THE NORTHWESTERN UNITED STATES AND A WEAK
ANTICYCLONIC FLOW APPEARS TO BE LOCATED ACROSS EASTERN NEW
MEXICO. A 70KT UPPER LEVEL JET WAS LOCATED WEST OF A 500MB HIGH
AND EXTENDED FROM SOUTHWEST WYOMING INTO SOUTHEAST CALIFORNIA.
ANOTHER JET STREAK WAS LOCATED BETWEEN THE DEVELOPING EAST TEXAS
UPPER LOW AND THE SOUTHEAST COLORADO UPPER HIGH. THE NOSE OF THIS
UPPER JET WAS LOCATED NEAR SOUTH CENTRAL KANSAS AND NORTHWEST
OKLAHOMA. A 700MB HIGH EXTENDED FROM THE PANHANDLE OF OKLAHOMA
ACROSS WESTERN KANSAS WITH TEMPERATURES RANGING FROM +12C AT DODGE
CITY, AMARILLO, AND NORTH PLATTE TO +17C AT DENVER. AN AREA OF
HIGHER DEWPOINTS WERE ALSO PRESENT ALONG AND EAST OF THE 12C
ISOTHERM. 850MB TEMPERATURES ACROSS WESTERN KANSAS AT 00Z SUNDAY
WERE 1-2C WARMER WHEN COMPARED TO 00Z SATURDAY TEMPERATURES BUT
SOME COOLING (1-2C) WAS OBSERVED AT OKLAHOMA CITY AND SPRINGFIELD.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW) ISSUED AT 304 PM
CDT SAT JUL 14 2012
A RIDGE OF UPPER LEVEL HIGH PRESSURE WILL DOMINATE THE HIGH PLAINS
FROM NEW MEXICO INTO WESTERN KANSAS AND NEBRASKA INTO SUNDAY. A LEE
TROUGH OF LOW PRESSURE WILL ALSO REMAIN IN EASTERN COLORADO WITH
LIGHT SOUTH TO SOUTHEAST WINDS TONIGHT. THE PRESSURE GRADIENT THEN
TIGHTENS ON SUNDAY WITH SOUTH TO SOUTHWEST WINDS OF 15 TO 25 MPH AND
GUSTY. A MID LEVEL CAPPING INVERSION WILL ALSO CONTINUE INTO SUNDAY
AFTERNOON, AND WITH TEMPERATURES APPROACHING 100, THE CAP MAY WEAKEN
ENOUGH TO SUPPORT SOME HIGH BASED THUNDERSTORMS LATE THIS AFTERNOON
INTO EARLY EVENING AND AGAIN ON SUNDAY. WILL ADD A SLIGHT CHANCE OF
THUNDER MAINLY EAST OF A LINE FROM WAKEENEY TO MEADE. WITH DEWPOINTS
ALSO MIXING OUT, IF ANY THUNDERSTORMS FORM, THEY COULD PUT OUT SOME
LOCALLY STRONG GUSTS FROM 40 TO 50 MPH. THE HRRR MESOSCALE MODEL
ALSO SUPPORTS A FEW THUNDERSTORMS LATE THIS AFTERNOON AND EARLY
EVENING.
OVERNIGHT LOWS WILL BE MILD AND IN THE MID TO UPPER 60S UNDER MOSTLY
CLEAR SKIES. FOR SUNDAY EXPECT HIGHS NEAR THE CENTURY MARK WITH
MOSTLY CLEAR TO PARTLY CLOUDY SKIES.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 435 PM CDT SAT JUL 14 2012
THERE WERE LITTLE OVERALL CHANGES IN EXPECTATIONS NOTED FOR THE
EXTENDED FORECAST PERIOD. THE GENERAL PATTERN CONTINUES TO INDICATE
A WEAKLY POSITIVE TILTED UPPER RIDGE BUILDING INTO THE GREAT PLAINS.
THE RIDGE BECOMES SLOWLY FLATTENED WITH TIME AS SHORTWAVES RIDE THE
NORTHERN PERIPHERY OF THIS RIDGE THROUGH THE WEEK. THIS WARM AIRMASS
WILL BE MARKED BY WARM TEMPERATURES IN THE MID TO UPPER 90S, AND
TEMPERATURES AROUND 100 DEGREES BY MID TO LATE WEEK. CAPPING IS
WEAK, ESPECIALLY ACROSS CENTRAL KANSAS WHERE 700 MB TEMPERATURES ARE
UNDER 10 DEGREES C. AN ISOLATED BRIEF AIRMASS THUNDERSTORM CANNOT
BE COMPLETELY RULED OUT ANY DAY, BUT CHANCES ARE QUITE LOW GIVEN THE
LACK OF NOTED SURFACE CONVERGENCE. THE BEST CHANCES MIGHT BE FARTHER
WEST AND SOUTH ON THE HIGHER TERRAIN OF THE PANHANDLES AND EASTERN
COLORADO. SOUTHWEST KANSAS SHOULD REMAIN IN A WARM SECTOR THROUGH HE
ENTIRE PERIOD, WHILE A STATIONARY FRONT RUNNING FROM IOWA THROUGH
NEBRASKA AND SOUTH DAKOTA SHOULD BE A FOCUS FOR MESOSCALE CONVECTIVE
SYSTEMS EACH NIGHT THROUGH THE MID TO LATE WEEK, AND REMAIN FOCUSED
WELL AWAY FROM CENTRAL KANSAS. CONVECTIVE STORMS THAT DEVELOP FARTHER
WEST WILL HAVE POOR STEERING FLOW WITH SUCH LIGHT MEAN WINDS DUE TO
THE UPPER HIGH. THE ATMOSPHERE WILL PROBABLY BE MORE CONDUCIVE TO
HEAT BURSTS AND GUSTY WINDS THAN TO SEVERE THUNDERSTORMS, ESPECIALLY
WEST OF HIGHWAY 283 TO THE COLORADO LINE.
TEMPERATURES BY LATE IN THE WEEK WERE RAISED A FEW DEGREES. SOME OF
THE BIAS CORRECTED MODEL OUTPUT STATISTICS GUIDANCE IS SUPPORTIVE OF
WARMER HIGHS UNDER THE UPPER RIDGE BY FRIDAY AND SATURDAY.
WIDESPREAD TEMPERATURES IN EXCESS OF 100 DEGREES AND POSSIBLY TO
AROUND 105 ARE INDICATED BY THIS GUIDANCE, AND SEEMS QUITE
REASONABLE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1209 AM CDT SUN JUL 15 2012
SURFACE PRESSURE GRADIENT ACROSS WESTERN KANSAS WILL STRENGTHEN
TODAY AS SURFACE PRESSURES FALL ALONG WITH LEE OF THE ROCKIES.
SURFACE LEE TROUGH WILL STAY WEST OF WESTERN KANSAS TODAY SO
SOUTH/SOUTHEAST WINDS WILL PERSIST AS WIND SPEEDS INCREASE INTO
THE 15 TO 20KT RANGE BY THE EARLY AFTERNOON. BUFR SOUNDINGS KEEP A
LAYER OF MOISTURE IN THE 700-600MB LEVEL ALONG WITH SOME WEAK MID
LEVEL INSTABILITY SO SOME HIGH BASED (VFR) CLOUDS ARE EXPECTED
LATER THIS MORNING/AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 72 97 72 98 / 0 10 10 10
GCK 70 98 72 97 / 0 0 10 10
EHA 68 99 70 95 / 10 10 10 10
LBL 70 99 72 97 / 0 10 10 10
HYS 71 98 74 99 / 0 10 10 10
P28 72 96 75 99 / 0 0 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...KRUSE
LONG TERM...RUSSELL
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS JACKSON KY
225 PM EDT SUN JUL 15 2012
.UPDATE...
ISSUED AT 225 PM EDT SUN JUL 15 2012
COVERAGE HAS PICKED UP ALONG AND SOUTH OF THE HAL ROGERS PARKWAY AND
HIGHWAY 80 CORRIDORS THANKS TO BUILDING INSTABILITY AS WELL AS AN
OUTFLOW BOUNDARY MOVING EAST SOUTHEAST ACROSS THE AREA. HAVE BEEFED
UP THE POPS DOWN SOUTH ALL THE WAY TO THE PORTIONS OF THE VIRGINIA
BORDER AS CONVECTION WILL LIKELY KEEP POPPING AS THE OUTFLOW BOUNDARY
CONTINUES TO MOVE THROUGH SOUTHEAST KENTUCKY. HAVE REDUCED POPS
FURTHER NORTH TO JUST SCATTERED AS THE UPPER LEVEL FORCING GRADUALLY
LESSENS.
ISSUED 1054 AM EDT SUN JUL 15 2012
SHOWERS CONTINUE TO FOCUS ALONG THE NORTHWEST PORTION OF
THE CWA THIS MORNING...AS A LOW LEVEL JET ALONG WITH SOME UPPER LEVEL
DIVERGENCE REMAIN IN PLACE NEAR THE OHIO RIVER. SOME OF THE HEAVIER
SHOWERS AND ISOLATED THUNDERSTORMS HAVE BEEN DROPPING A LOT OF RAIN
IN A SHORT PERIOD OF TIME...UP TO AN INCH IN LESS THAN 30 MINUTES.
FORTUNATELY...STORM MOTIONS ARE AROUND 15 KTS...HOWEVER WILL HAVE TO
MONITOR AT LEAST A FEW LOCATIONS FOR REPEATED ROUNDS...WHICH COULD
LEAD TO MINOR FLOODING IN LOW LYING AREAS AT A MINIMUM. HAVE
INCREASED POPS UP TO CATEGORICAL GIVEN THE RADAR TRENDS.
THE LATEST NAM SHOWS ACTIVITY PEAKING IN THE 15-18Z TIME FRAME AND
THEN SCATTERING OUT MORE FOR THE REST OF THE AFTERNOON AS SOME MID-
LEVEL CAPPING DEVELOPS. THIS IS SIMILAR TO THE 06Z RUN...SO IT MAY BE
ON TO SOMETHING. THE LAST RUN OF THE SREF CONTINUES THE HIGHER POPS
THROUGH 21Z AND THIS MAY ALSO BE A CONTENDER WITH ANY OUTFLOW
BOUNDARY INTERACTION. FOR NOW...WILL LEAN TOWARDS THE NAM IDEA.
FRESHENED UP THE REST OF THE GRIDS...MAINLY TO ALLOW FOR A FASTER
DIURNAL RISE WHERE CLOUDS ARE STARTING OUT THINNER. HIGHS RANGING
FROM THE LOWER 80S IN THE NORTH TO A FEW UPPER 80S IN THE SOUTHEAST
LOOK ON TARGET.
UPDATE ISSUED AT 700 AM EDT SUN JUL 15 2012
SHOWERS HAVE INCREASED OVER ERN KY THIS MORNING WITH A FEW RUMBLES
AS WELL...LENDING SOME CREDIBILITY TO THE HRRR AND NAM12...AND HAVE
BENT THE GRIDS IN THIS DIRECTION THROUGH THE REMAINDER OF THE
MORNING. ALSO UPDATED SKY...ALONG WITH TEMPS AND DEW PTS TO ESTABLISH
TRENDS HEADING INTO THE DAY. OTHERWISE...THE FCST IS ESSENTIALLY ON
TRACK. UPDATED ZONES WILL BE ISSUED SHORTLY.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 232 AM EDT SUN JUL 15 2012
ESSENTIALLY LOOKING AT A PERSISTENCE FORECAST FOR TODAY AND TONIGHT
WITH LITTLE CHANGE ANTICIPATED IN THE OVERALL. THE QUESTION REMAINS
WHERE AND WHEN CONVECTION WILL INITIATE...BUT THE NEAR TERM MODELS
ARE STILL PLUGGING SOME EARLY MORNING DEVELOPMENT OVER CNTRL TN AND
KY SPREADING EAST THROUGH THE MORNING AND CONTINUING THROUGH THE
AFTERNOON BEFORE DIMINISHING THIS EVENING FOLLOWING THE LOSS OF
DAYTIME HEATING.
MODELS ARE IN GENERAL AGREEMENT IN DEVELOPING SOME HEALTHY INSTABILITY
THIS MORNING...UPWARDS OF 3K J/KG MU CAPE AGAIN WITH CONVECTIVE TEMPS
IN THE LOWER 80S AND CURRENT FCST HIGHS IN THE MID 80S. FCST PWATS
CONTINUE TO RUN ABOUT 2 INCHES THROUGHOUT THE DAY...AND WITH A RIGHT
ENTRANCE REGION OF A MODEST 50-60KT UPPER LEVEL JET TRAVERSING UP THE
OHIO VALLEY THIS AFTERNOON...COUPLED WITH A MID LEVEL SHORT WAVE
MOVING UP FROM THE TN VALLEY...CAN SEE LITTLE REASON THIS MORNING
WHY WE WOULD NOT SEE SOME EFFICIENT TSTMS AGAIN LATER THIS MORNING
CONTINUING THROUGH THE AFTERNOON...WITH LOCALLY HEAVY RAINFALL AGAIN
THE PRIMARY CONCERN.
MONDAY IS LOOKING A LITTLE MORE INTERESTING THIS MORNING WITH FCST
SOUNDINGS DEPICTING A STRONGER CAP DEVELOPING BY LATE MORNING
CONTINUING THROUGH THE PEAK HEATING HOURS AS THE STRONG BERMUDA HIGH
IS PROGGED TO SHIFT WEST TOWARDS THE CENTRAL APPALACHIANS...WEAKENING
SLIGHTLY IN THE PROCESS. DRIER...BUT WARMER MID LEVEL ADVECTION WILL
EITHER SQUASH PRECIP CHANCES OR...IF THE CAP BREAKS...COULD RESULT
IN SOME STRONG STORMS AGAIN DEVELOPING DURING THE AFTERNOON WITH
DAMAGING WINDS POSSIBLE IN ADDITION TO THE THREAT FOR LOCALLY HEAVY
RAINFALL.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 232 AM EDT SUN JUL 15 2012
THE MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE GENERAL LONG WAVE
PATTERN...HOWEVER THERE ARE SOME DIFFERENCES IN THE TIMING SOME OF
THE SHORT WAVES LATER ON DURING THE PERIOD. ON MONDAY
NIGHT...KENTUCKY WILL BE DOMINATED BY THE UPPER RIDGE WITH A MAJOR
TROUGH JUST OFF THE WEST COAST. ALL THE FRONTAL ACTIVITY WILL BE
WELL NORTH OF THE AREA AND THE COAL FIELDS WILL BE DOMINATED BY THE
WARM...MOIST AND UNSTABLE AIR MASS. WITH TIME...AN UPPER TROUGH BEGINS
TO DROP SOUTH FROM AN UPPER LOW CENTER OVER THE CANADIAN MARITIMES.
THIS WILL ALLOW A COLD FRONT TO START MOVING TO THE SOUTH. BY
THURSDAY MORNING...THE FRONT WILL BE OVER NORTHERN KENTUCKY AND WILL
SLOWLY MOVE SOUTH DURING THE DAY. BY FRIDAY MORNING THE FRONT WILL
HAVE MOVED INTO CENTRAL TENNESSEE. THE 00GMT GFS IS WANTING TO SLOW
THE FRONT DOWN AND SORT OF STALL IT OVER THE AREA ON FRIDAY...WHILE
THE 12 GMT ECMWF WANTS TO MOVES IT SOUTH OF THE AREA MORE QUICKLY.
IN GENERAL...I HAVE MORE CONFIDENCE IN THE ECMWF AND WILL BE NUDGING
THE FORECAST TOWARD THE FASTER FRONTAL PASSAGE. IN EITHER CASE...AS
THE FRONT MOVES TO THE SOUTH...DRIER AIR WILL BE MOVING INTO THE
AREA AND MAKE THINGS MORE COMFORTABLE. EVEN THOUGH THE HIGHS WILL
STILL BE A LITTLE ABOVE NORMAL. THE OVERNIGHT LOWS WILL DROP DUE TO
THE DRIER AIR. IN THE MEAN TIME...KENTUCKY WILL BE UNDER A DIRTY
RIDGE WITH WARM MOIST UNSTABLE AIR OVER THE AREA WHICH WILL BE ABLE
TO PRODUCE MAINLY AFTERNOON AND EVENING CONVECTIVE THUNDERSTORMS AND
SHOWERS AND WILL KEEP TEMPERATURES WARM AND MISERABLE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 225 PM EDT SUN JUL 15 2012
SCATTERED TO NUMEROUS CONVECTION IS POPPING ACROSS THE
AREA...PARTICULARLY ALONG AND SOUTH OF THE HAL ROGERS PARKWAY AND
HIGHWAY 80 CORRIDORS. LOZ LOOKS TO SEE THE BEST CHANCE OF SEEING A
DIRECT HIT FROM THUNDERSTORMS AND HAVE INCLUDED A TEMPO BETWEEN 19
AND 21Z. HAVE HELD ONTO VCTS ELSEWHERE. FOG WILL AGAIN BE A CONCERN
TONIGHT AND HAVE GONE IFR AT MOST LOCATIONS...ALTHOUGH LIFR OR WORSE
IN LOCATIONS THAT HAVE SEEN THE HEAVIER RAIN SHOWERS IS LIKELY. ONCE
THE FOG BURNS OFF MONDAY MORNING...CONVECTION WILL LIKELY THREATEN
ONCE AGAIN...ALTHOUGH THIS MAY BE A BIT LATER IN THE DAY THAN WE HAVE
SEEN COMPARED TO THE LAST SEVERAL DAYS SO HAVE LEFT OUT ANY MENTION
FOR NOW.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...MB
LONG TERM....JJ
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS JACKSON KY
1054 AM EDT SUN JUL 15 2012
.UPDATE...
ISSUED AT 1054 AM EDT SUN JUL 15 2012
SHOWERS CONTINUE TO FOCUS ALONG THE NORTHWEST PORTION OF THE CWA
THIS MORNING...AS A LOW LEVEL JET ALONG WITH SOME UPPER LEVEL
DIVERGENCE REMAIN IN PLACE NEAR THE OHIO RIVER. SOME OF THE HEAVIER
SHOWERS AND ISOLATED THUNDERSTORMS HAVE BEEN DROPPING A LOT OF RAIN
IN A SHORT PERIOD OF TIME...UP TO AN INCH IN LESS THAN 30 MINUTES.
FORTUNATELY...STORM MOTIONS ARE AROUND 15 KTS...HOWEVER WILL HAVE TO
MONITOR AT LEAST A FEW LOCATIONS FOR REPEATED ROUNDS...WHICH COULD
LEAD TO MINOR FLOODING IN LOW LYING AREAS AT A MINIMUM. HAVE
INCREASED POPS UP TO CATEGORICAL GIVEN THE RADAR TRENDS.
THE LATEST NAM SHOWS ACTIVITY PEAKING IN THE 15-18Z TIME FRAME AND
THEN SCATTERING OUT MORE FOR THE REST OF THE AFTERNOON AS SOME MID-
LEVEL CAPPING DEVELOPS. THIS IS SIMILAR TO THE 06Z RUN...SO IT MAY BE
ON TO SOMETHING. THE LAST RUN OF THE SREF CONTINUES THE HIGHER POPS
THROUGH 21Z AND THIS MAY ALSO BE A CONTENDER WITH ANY OUTFLOW
BOUNDARY INTERACTION. FOR NOW...WILL LEAN TOWARDS THE NAM IDEA.
FRESHENED UP THE REST OF THE GRIDS...MAINLY TO ALLOW FOR A FASTER
DIURNAL RISE WHERE CLOUDS ARE STARTING OUT THINNER. HIGHS RANGING
FROM THE LOWER 80S IN THE NORTH TO A FEW UPPER 80S IN THE SOUTHEAST
LOOK ON TARGET.
UPDATE ISSUED AT 700 AM EDT SUN JUL 15 2012
SHOWERS HAVE INCREASED OVER ERN KY THIS MORNING WITH A FEW RUMBLES
AS WELL...LENDING SOME CREDIBILITY TO THE HRRR AND NAM12...AND HAVE
BENT THE GRIDS IN THIS DIRECTION THROUGH THE REMAINDER OF THE
MORNING. ALSO UPDATED SKY...ALONG WITH TEMPS AND DEW PTS TO ESTABLISH
TRENDS HEADING INTO THE DAY. OTHERWISE...THE FCST IS ESSENTIALLY ON
TRACK. UPDATED ZONES WILL BE ISSUED SHORTLY.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 232 AM EDT SUN JUL 15 2012
ESSENTIALLY LOOKING AT A PERSISTENCE FORECAST FOR TODAY AND TONIGHT
WITH LITTLE CHANGE ANTICIPATED IN THE OVERALL. THE QUESTION REMAINS
WHERE AND WHEN CONVECTION WILL INITIATE...BUT THE NEAR TERM MODELS
ARE STILL PLUGGING SOME EARLY MORNING DEVELOPMENT OVER CNTRL TN AND
KY SPREADING EAST THROUGH THE MORNING AND CONTINUING THROUGH THE
AFTERNOON BEFORE DIMINISHING THIS EVENING FOLLOWING THE LOSS OF
DAYTIME HEATING.
MODELS ARE IN GENERAL AGREEMENT IN DEVELOPING SOME HEALTHY INSTABILITY
THIS MORNING...UPWARDS OF 3K J/KG MU CAPE AGAIN WITH CONVECTIVE TEMPS
IN THE LOWER 80S AND CURRENT FCST HIGHS IN THE MID 80S. FCST PWATS
CONTINUE TO RUN ABOUT 2 INCHES THROUGHOUT THE DAY...AND WITH A RIGHT
ENTRANCE REGION OF A MODEST 50-60KT UPPER LEVEL JET TRAVERSING UP THE
OHIO VALLEY THIS AFTERNOON...COUPLED WITH A MID LEVEL SHORT WAVE
MOVING UP FROM THE TN VALLEY...CAN SEE LITTLE REASON THIS MORNING
WHY WE WOULD NOT SEE SOME EFFICIENT TSTMS AGAIN LATER THIS MORNING
CONTINUING THROUGH THE AFTERNOON...WITH LOCALLY HEAVY RAINFALL AGAIN
THE PRIMARY CONCERN.
MONDAY IS LOOKING A LITTLE MORE INTERESTING THIS MORNING WITH FCST
SOUNDINGS DEPICTING A STRONGER CAP DEVELOPING BY LATE MORNING
CONTINUING THROUGH THE PEAK HEATING HOURS AS THE STRONG BERMUDA HIGH
IS PROGGED TO SHIFT WEST TOWARDS THE CENTRAL APPALACHIANS...WEAKENING
SLIGHTLY IN THE PROCESS. DRIER...BUT WARMER MID LEVEL ADVECTION WILL
EITHER SQUASH PRECIP CHANCES OR...IF THE CAP BREAKS...COULD RESULT
IN SOME STRONG STORMS AGAIN DEVELOPING DURING THE AFTERNOON WITH
DAMAGING WINDS POSSIBLE IN ADDITION TO THE THREAT FOR LOCALLY HEAVY
RAINFALL.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 232 PM EDT SAT JUL 14 2012
THE MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE GENERAL LONG WAVE
PATTERN...HOWEVER THERE ARE SOME DIFFERENCES IN THE TIMING SOME OF
THE SHORT WAVES LATER ON DURING THE PERIOD. ON MONDAY
NIGHT...KENTUCKY WILL BE DOMINATED BY THE UPPER RIDGE WITH A MAJOR
TROUGH JUST OFF THE WEST COAST. ALL THE FRONTAL ACTIVITY WILL BE
WELL NORTH OF THE AREA AND THE COAL FIELDS WILL BE DOMINATED BY THE
WARM...MOIST AND UNSTABLE AIR MASS. WITH TIME...AN UPPER TROUGH BEGINS
TO DROP SOUTH FROM AN UPPER LOW CENTER OVER THE CANADIAN MARITIMES.
THIS WILL ALLOW A COLD FRONT TO START MOVING TO THE SOUTH. BY
THURSDAY MORNING...THE FRONT WILL BE OVER NORTHERN KENTUCKY AND WILL
SLOWLY MOVE SOUTH DURING THE DAY. BY FRIDAY MORNING THE FRONT WILL
HAVE MOVED INTO CENTRAL TENNESSEE. THE 00GMT GFS IS WANTING TO SLOW
THE FRONT DOWN AND SORT OF STALL IT OVER THE AREA ON FRIDAY...WHILE
THE 12 GMT ECMWF WANTS TO MOVES IT SOUTH OF THE AREA MORE QUICKLY.
IN GENERAL...I HAVE MORE CONFIDENCE IN THE ECMWF AND WILL BE NUDGING
THE FORECAST TOWARD THE FASTER FRONTAL PASSAGE. IN EITHER CASE...AS
THE FRONT MOVES TO THE SOUTH...DRIER AIR WILL BE MOVING INTO THE
AREA AND MAKE THINGS MORE COMFORTABLE. EVEN THOUGH THE HIGHS WILL
STILL BE A LITTLE ABOVE NORMAL. THE OVERNIGHT LOWS WILL DROP DUE TO
THE DRIER AIR. IN THE MEAN TIME...KENTUCKY WILL BE UNDER A DIRTY
RIDGE WITH WARM MOIST UNSTABLE AIR OVER THE AREA WHICH WILL BE ABLE
TO PRODUCE MAINLY AFTERNOON AND EVENING CONVECTIVE THUNDERSTORMS AND
SHOWERS AND WILL KEEP TEMPERATURES WARM AND MISERABLE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 700 AM EDT SUN JUL 15 2012
SCT SHRA WITH A FEW TSTMS MOVING NE ACROSS CNTRL AND NERN KY THIS
MORNING BUT ARE NOT AFFECTING THE TAF SITES JUST YET. MORE TSTMS ARE
EXPECTED TO DEVELOP THROUGH THE MORNING AND CONTINUE THROUGH THE
AFTERNOON...AND WILL ONCE AGAIN BRING TEMPORARY...LOCALIZED IFR OR
WORSE TO ANY TERMINAL THAT SEES CONVECTION TODAY. HOWEVER...WITH LOW
CONFIDENCE IN TIMING AND EXACT PLACEMENT...WILL CONTINUE WITH VC
GROUPS. LOW LEVEL WINDS ARE EXPECTED TO REDEVELOP AFTER 12Z OUT OF
THE SW TO AROUND 5 TO 10 KTS AND CONTINUE THROUGH THE EVENING BEFORE
DIMINISHING WITH CONVECTION AFTER SUNSET.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...MB
LONG TERM....JJ
AVIATION...MB
AREA FORECAST DISCUSSION
NWS JACKSON KY
701 AM EDT SUN JUL 15 2012
.UPDATE...
ISSUED AT 700 AM EDT SUN JUL 15 2012
SHOWERS HAVE INCREASED OVER ERN KY THIS MORNING WITH A FEW RUMBLES
AS WELL...LENDING SOME CREDIBILITY TO THE HRRR AND NAM12...AND HAVE
BENT THE GRIDS IN THIS DIRECTION THROUGH THE REMAINDER OF THE
MORNING. ALSO UPDATED SKY...ALONG WITH TEMPS AND DEW PTS TO ESTABLISH
TRENDS HEADING INTO THE DAY. OTHERWISE...THE FCST IS ESSENTIALLY ON
TRACK. UPDATED ZONES WILL BE ISSUED SHORTLY.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 232 AM EDT SUN JUL 15 2012
ESSENTIALLY LOOKING AT A PERSISTENCE FORECAST FOR TODAY AND TONIGHT
WITH LITTLE CHANGE ANTICIPATED IN THE OVERALL. THE QUESTION REMAINS
WHERE AND WHEN CONVECTION WILL INITIATE...BUT THE NEAR TERM MODELS
ARE STILL PLUGGING SOME EARLY MORNING DEVELOPMENT OVER CNTRL TN AND
KY SPREADING EAST THROUGH THE MORNING AND CONTINUING THROUGH THE
AFTERNOON BEFORE DIMINISHING THIS EVENING FOLLOWING THE LOSS OF
DAYTIME HEATING.
MODELS ARE IN GENERAL AGREEMENT IN DEVELOPING SOME HEALTHY INSTABILITY
THIS MORNING...UPWARDS OF 3K J/KG MU CAPE AGAIN WITH CONVECTIVE TEMPS
IN THE LOWER 80S AND CURRENT FCST HIGHS IN THE MID 80S. FCST PWATS
CONTINUE TO RUN ABOUT 2 INCHES THROUGHOUT THE DAY...AND WITH A RIGHT
ENTRANCE REGION OF A MODEST 50-60KT UPPER LEVEL JET TRAVERSING UP THE
OHIO VALLEY THIS AFTERNOON...COUPLED WITH A MID LEVEL SHORT WAVE
MOVING UP FROM THE TN VALLEY...CAN SEE LITTLE REASON THIS MORNING
WHY WE WOULD NOT SEE SOME EFFICIENT TSTMS AGAIN LATER THIS MORNING
CONTINUING THROUGH THE AFTERNOON...WITH LOCALLY HEAVY RAINFALL AGAIN
THE PRIMARY CONCERN.
MONDAY IS LOOKING A LITTLE MORE INTERESTING THIS MORNING WITH FCST
SOUNDINGS DEPICTING A STRONGER CAP DEVELOPING BY LATE MORNING
CONTINUING THROUGH THE PEAK HEATING HOURS AS THE STRONG BERMUDA HIGH
IS PROGGED TO SHIFT WEST TOWARDS THE CENTRAL APPALACHIANS...WEAKENING
SLIGHTLY IN THE PROCESS. DRIER...BUT WARMER MID LEVEL ADVECTION WILL
EITHER SQUASH PRECIP CHANCES OR...IF THE CAP BREAKS...COULD RESULT
IN SOME STRONG STORMS AGAIN DEVELOPING DURING THE AFTERNOON WITH
DAMAGING WINDS POSSIBLE IN ADDITION TO THE THREAT FOR LOCALLY HEAVY
RAINFALL.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 232 PM EDT SAT JUL 14 2012
THE MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE GENERAL LONG WAVE
PATTERN...HOWEVER THERE ARE SOME DIFFERENCES IN THE TIMING SOME OF
THE SHORT WAVES LATER ON DURING THE PERIOD. ON MONDAY
NIGHT...KENTUCKY WILL BE DOMINATED BY THE UPPER RIDGE WITH A MAJOR
TROUGH JUST OFF THE WEST COAST. ALL THE FRONTAL ACTIVITY WILL BE
WELL NORTH OF THE AREA AND THE COAL FIELDS WILL BE DOMINATED BY THE
WARM...MOIST AND UNSTABLE AIR MASS. WITH TIME...AN UPPER TROUGH BEGINS
TO DROP SOUTH FROM AN UPPER LOW CENTER OVER THE CANADIAN MARITIMES.
THIS WILL ALLOW A COLD FRONT TO START MOVING TO THE SOUTH. BY
THURSDAY MORNING...THE FRONT WILL BE OVER NORTHERN KENTUCKY AND WILL
SLOWLY MOVE SOUTH DURING THE DAY. BY FRIDAY MORNING THE FRONT WILL
HAVE MOVED INTO CENTRAL TENNESSEE. THE 00GMT GFS IS WANTING TO SLOW
THE FRONT DOWN AND SORT OF STALL IT OVER THE AREA ON FRIDAY...WHILE
THE 12 GMT ECMWF WANTS TO MOVES IT SOUTH OF THE AREA MORE QUICKLY.
IN GENERAL...I HAVE MORE CONFIDENCE IN THE ECMWF AND WILL BE NUDGING
THE FORECAST TOWARD THE FASTER FRONTAL PASSAGE. IN EITHER CASE...AS
THE FRONT MOVES TO THE SOUTH...DRIER AIR WILL BE MOVING INTO THE
AREA AND MAKE THINGS MORE COMFORTABLE. EVEN THOUGH THE HIGHS WILL
STILL BE A LITTLE ABOVE NORMAL. THE OVERNIGHT LOWS WILL DROP DUE TO
THE DRIER AIR. IN THE MEAN TIME...KENTUCKY WILL BE UNDER A DIRTY
RIDGE WITH WARM MOIST UNSTABLE AIR OVER THE AREA WHICH WILL BE ABLE
TO PRODUCE MAINLY AFTERNOON AND EVENING CONVECTIVE THUNDERSTORMS AND
SHOWERS AND WILL KEEP TEMPERATURES WARM AND MISERABLE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 700 AM EDT SUN JUL 15 2012
SCT SHRA WITH A FEW TSTMS MOVING NE ACROSS CNTRL AND NERN KY THIS
MORNING BUT ARE NOT AFFECTING THE TAF SITES JUST YET. MORE TSTMS ARE
EXPECTED TO DEVELOP THROUGH THE MORNING AND CONTINUE THROUGH THE
AFTERNOON...AND WILL ONCE AGAIN BRING TEMPORARY...LOCALIZED IFR OR
WORSE TO ANY TERMINAL THAT SEES CONVECTION TODAY. HOWEVER...WITH LOW
CONFIDENCE IN TIMING AND EXACT PLACEMENT...WILL CONTINUE WITH VC
GROUPS. LOW LEVEL WINDS ARE EXPECTED TO REDEVELOP AFTER 12Z OUT OF
THE SW TO AROUND 5 TO 10 KTS AND CONTINUE THROUGH THE EVENING BEFORE
DIMINISHING WITH CONVECTION AFTER SUNSET.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MB
SHORT TERM...MB
LONG TERM....JJ
AVIATION...MB
AREA FORECAST DISCUSSION
NWS JACKSON KY
123 AM EDT SUN JUL 15 2012
.UPDATE...
ISSUED AT 1100 PM EDT SAT JUL 14 2012
CONVECTION HAS DISSIPATED WITH THE LOSS OF DAYTIME HEATING. OVERNIGHT...
A LULL IN THE ACTIVITY IS EXPECTED...BUT 21Z SREF AND 0Z NAM SHOW
CONVECTIVE DEVELOPMENT GENERALLY OVER WESTERN SECTIONS TOWARD DAWN IN
ADVANCE OF AN APPROACHING SHORTWAVE. THE 18Z GFS IS RELATIVELY CONSISTENT
WITH THIS IDEA AS WELL. THEREFORE WE HAVE CONTINUED WITH A LULL IN
POPS OVER THE NEXT COUPLE OF HOURS AND THEN HAVE THEM INCREASING INTO
THE ISOLATED TO SCATTERED RANGE LATE. SOME SLIGHT ADJUSTMENTS TO
HOURLY TEMPS AND DEWPOINTS WERE ALSO MADE. UPDATED GRIDS AND ZFP ARE
ALREADY OUT.
UPDATE ISSUED AT 815 PM EDT SAT JUL 14 2012
CONVECTION CONTINUES TO WEAKEN AS WE APPROACH SUNSET...AND OVERALL
INTENSITIES HAVE DIMINISHED OVER THE PAST HOUR OR SO. MEASURABLE RAIN
CHANCES WILL BE HIGHEST INITIALLY FROM NEAR JKL TOWARD THE BIG SANDY
REGION AS THE REMAINING CONVECTION WORKS EAST NORTHEAST AND GRADUALLY
IS EXPECTED TO CONTINUE TO WEAKEN OVER THE NEXT TWO HOURS. POPS AND
SKY WERE UPDATED ACCORDINGLY BASED ON THESE TRENDS.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 335 PM EDT SAT JUL 14 2012
19Z SFC ANALYSIS SHOWS A WEAK PRESSURE PATTERN THROUGHOUT EAST
KENTUCKY WITH NO CLEAR SYNOPTIC SCALE FEATURES TO KEY IN ON.
HOWEVER...GIVEN THE HIGH PW AIR IN PLACE...NO CAP...AND SOME UPPER
LEVEL ENERGY...NOT MUCH WAS NEEDED TO INITIATE THE STORMS LATE THIS
MORNING THAT CONTINUE TO PERCOLATE OVER THE CWA AT THIS HOUR. THE
CLOUDS FILLED IN FROM THE SOUTH BY MID MORNING AND CONVECTION
FOLLOWED SHORTLY THEREAFTER. A FEW OF THE CELLS HAVE GOTTEN STRONG
AND OTHERS HAVE MERGED/TRAINED OVER THE SAME SPOTS CREATING A CONCERN
FOR MINOR URBAN OR SMALL STREAM FLOODING. REGARDLESS...THE RAINS IN
MANY LOCATIONS ARE NOW PUTTING A SERIOUS DENT IN THEIR ANNUAL
RAINFALL DEFICIT THANKS TO THESE PAST FEW DAYS. TEMPERATURES THIS
AFTERNOON HAVE BEEN HIGHLY DEPENDENT ON THE CONVECTIVE PATTERN AND
BREAKS FOR SUNSHINE WITH READINGS CURRENTLY RANGING FROM THE LOW 70S
IN THE RAIN COOLED SOUTHERN I-75 CORRIDOR TO MID 80S JUST SOUTH OF
STORMS NEAR I-64 AND IN THE...THUS FAR RAIN FREE...FAR SOUTHEAST.
DEWPOINTS...MEANWHILE...REMAIN PEGGED IN THE LOW TO MID 70S SUPPLYING
ALL THE JUICE THE CONVECTION COULD NEED.
THE MODELS REMAIN IN AGREEMENT THAT EAST KENTUCKY WILL BE ON THE
FRINGE OF THE WESTERN EXTENT OF A WEAK BERMUDA RIDGE AND AHEAD OF
TROUGHING COMING FROM THE NORTHERN PLAINS AND CROSSING THE GREAT
LAKES ON SUNDAY. THE ENERGY FROM THIS TROUGH WILL PASS BY TO THE
NORTH LATER SUNDAY AND THIS WILL SERVE TO FURTHER LIMIT THE EFFECT OF
THE EASTERN RIDGE ON OUR WEATHER INTO THE START OF THE NEW WORK WEEK.
IN THIS ENVIRONMENT THE MESOSCALE...OR SMALLER...WILL DOMINATE SO
HAVE LEANED MOST HEAVILY ON THE DETAILS OF THE NAM12 WITH A HEALTHY
DOSE OF THE HRRR EARLY ON TONIGHT.
SENSIBLE WEATHER WILL FEATURE SHOWERS AND THUNDERSTORMS WINDING
DOWN...FOR THE MOST PART...AFTER SUNSET...BUT NOT BEFORE LEAVING
BEHIND A FAIR AMOUNT OF RAINFALL IN SEVERAL LOCATIONS. EXPECT A LULL
THROUGH THE MIDDLE OF THE NIGHT WITH PATCHY FOG A GOOD BET. THE
APPROACH OF A SHORTWAVE INTO THE OHIO VALLEY LATE TONIGHT GIVES SOME
CREDENCE TO THE NAM12/S IDEA OF A CONVECTIVE CLUSTER FORMING OVER
CENTRAL TENNESSEE AND DRIFTING INTO THE CUMBERLAND VALLEY BY DAWN.
SOME SUPPORT FROM THE GFS BOLSTERS THIS IDEA...AS WELL. ACCORDINGLY...
HAVE DEVIATED FROM A STRICTLY DIURNALLY DRIVEN POP AND WX PATTERN TO
ALLOW FOR THIS IDEA IN THE GRIDS...THOUGH NOT WHOLE HOG JUST YET.
OTHERWISE...EXPECT A NEAR REPEAT OF TODAY FOR SUNDAY WITH CONVECTION
DRIVEN MAINLY BY DIURNAL HEATING AND MINOR OUTFLOWS/DIFFERENTIAL
HEATING BOUNDARIES. FOR BOTH TONIGHT AND SUNDAY NIGHT HAVE BEEN
GENEROUS WITH THE PATCHY FOG IN THE GRIDS AFTER MIDNIGHT...BUT HELD
OFF ON ANY DENSE UNTIL IT BECOMES MORE APPARENT WHERE THE BEST
NOCTURNAL CLEARING WILL OCCUR.
FOR TEMPERATURES...FOLLOWED A BLEND OF THE INHERITED GRIDS...
PERSISTENCE...AND SOME OF THE LATEST MET VALUES...AGAIN NOT MUCH IN
THE WAY OF TERRAIN EFFECTS FOR LOWS GIVEN THE HIGH DEWPOINTS. AS FOR
POPS...HAVE ENDED UP SIMILAR TO A BLEND OF THE MET AND MAV MOS
THROUGHOUT THE PERIOD.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 340 PM EDT SAT JUL 14 2012
THE MODELS REMAIN IN VERY GOOD AGREEMENT WITH THE GENERAL LONG WAVE
PATTERN THROUGH THE EXTENDED. A SHORT WAVE TROUGH WILL BE EXITING
THE APPALACHIANS ON MONDAY...HELPING TO TEMPORARILY BUCKLE
RIDGING ACROSS THE PLAINS AND INTO THE MISSISSIPPI VALLEY THROUGH
TUESDAY. THE RIDGE WILL THEN BUILD BACK IN STRONGER ACROSS THE
PLAINS...WITH A MORE VIGOROUS SHORT WAVE TROUGH TO MOVE THROUGH THE
GREAT LAKES AND NEW ENGLAND FOR WEDNESDAY AND THURSDAY...SENDING A
COLD FRONT SOUTH ACROSS THE OHIO VALLEY. THE MODELS HAVE COME ON
BOARD A BIT MORE...WITH A MORE PROGRESSIVE SOLUTION FOR THESE
FEATURES. FOR EASTERN KENTUCKY...THIS WILL KEEP THE THREAT OF
SCATTERED...MAINLY DIURNALLY DRIVEN CONVECTION ACROSS MOST OF THE AREA
THROUGH FRIDAY...BEFORE DEEPER MOISTURE SINKS FAR ENOUGH SOUTH ON
SATURDAY...TO ONLY JUSTIFY A FEW POPS UP ALONG THE TN/VA BORDER.
TEMPERATURES CONTINUE TO LOOK SLIGHTLY ABOVE NORMAL...WITH
PERSISTENT HUMIDITY UNTIL NEXT WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 123 AM EDT SUN JUL 15 2012
FOG AGAIN WILL BE THE FORECAST CHALLENGE THROUGH THE FIRST 6 HRS OF
THE PERIOD. VFR CONDITIONS ARE PRESENT AT ALL TAF SITES AT ISSUANCE
BUT CIGS ARE GRADUALLY THINNING AND THIS SHOULD ALLOW FOR ANOTHER
ROUND OF LOW STRATUS BUILDING DOWN INTO THE VALLEYS TOWARDS
DAYBREAK...WITH IFR OR WORSE DEVELOPING ON THE RIDGES WITHIN THE FIRST
COUPLE OF HOURS OF THE PERIOD BEFORE AFFECTING THE LOWER ELEVATIONS
BETWEEN 10Z AND 12Z. NEAR TERM MODELS SHOW PRECIP DEVELOPING OVER TN
BEFORE MOVING INTO CENTRAL KY AROUND 12Z AND HAVE INCLUDED VC GROUPS
TO ADDRESS THIS. SCATTERED TO NUMEROUS TSTMS ARE EXPECTED TO DEVELOP
THIS AFTERNOON AND WILL ONCE AGAIN BRING TEMPORARY...LOCALIZED IFR OR
WORSE TO ANY TERMINAL THAT SEES CONVECTION TODAY. HOWEVER...WITH LOW
CONFIDENCE IN TIMING AND EXACT PLACEMENT OF CONVECTION...WILL
CONTINUE WITH VC GROUPS FOR NOW AND LET THE 12Z ISSUANCE TAKE A
BETTER LOOK AT THIS. LOW LEVEL WINDS ARE EXPECTED TO REDEVELOP AFTER
12Z OUT OF THE SW TO AROUND 5 TO 10 KTS AND CONTINUE THROUGH THE
EVENING BEFORE DIMINISHING WITH CONVECTION AFTER SUNSET.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM....GEOGERIAN
AVIATION...MB
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
824 PM EDT MON JUL 16 2012
.SYNOPSIS...
LOW PRESSURE WILL MOVE EAST OUT OF THE GREAT LAKES AND THROUGH
SOUTHERN CANADA ON TUESDAY. A COLD FRONT WILL PUSH ACROSS NEW
ENGLAND DURING THE EVENING ON TUESDAY WITH SHOWERS AND
THUNDERSTORMS EXPECTED IN THE HOT AND HUMID AIR MASS AHEAD OF THE
FRONT. THE FRONT MOVES FULLY THROUGH THE REGION ON WEDNESDAY WITH
COOLER AND DRIER AIR BEHIND IT. HIGH PRESSURE BUILDS DOWN OUT OF
CANADA THROUGH THE END OF THE WEEK. ANOTHER DISTURBANCE IS
FORECAST TO APPROACH NEW ENGLAND EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
.UPDATE...
LIGHT CONVECTIVE SHOWERS ARE STILL MOVING THROUGH THE CAPITAL
DISTRICT AS WELL AS NORTHERN NH AND NORTHWESTERN MAINE. WE HAVEN`T
HAD A LIGHTNING STRIKE SO FAR TONIGHT AND HAVE CHANGED WORDING TO
ISOLATED THUNDER FOR THE NEXT FEW HOURS FROM SKOWHEGAN NORTHWARD
WHERE SOME WEAK INSTABILITY REMAINS. OTHERWISE REMOVED THUNDER
FROM THE OVERNIGHT PERIOD AS WELL AS 500MB TEMPS WILL ONLY BE
AROUND -8 DEGREES C.
AFTER THESE DIURNAL SHOWERS END...WARM ADVECTION SHOWERS WILL
DEVELOP FROM WEST TO EAST REACHING LEBANON AND CONCORD AROUND 1 AM
BEFORE DRIFTING INTO THE WHITE MOUNTAINS. HAVE ADJUSTED POPS TO
BETTER REFLECT THIS TREND. ALSO ADJUSTED TEMPERATURES AND DEW
POINTS FOR HOURLY DISCREPANCIES.
&&
LATEST HRRR MODEL RUNS CONTINUE TO CAPTURE CONVECTION DRIFTING
SOUTHEAST OUT OF THE INTERIOR THIS AFTERNOON. THIS PRECIPITATION
SHOULD WIND DOWN AFTER SUNSET THIS EVENING. MCS OVER THE GREAT
LAKES CONTINUES TO WEAKEN AND HEAD RAPIDLY EAST TOWARDS OUR
REGION. THIS WILL SPILL ADDITIONAL CLOUD COVER TO THE REGION LATE
TONIGHT.
PATCHY FOG WILL DEVELOP OVER THE MARINE LAYER AND ACROSS THE
INTERIOR VALLEYS OVERNIGHT. USED A BLEND OF MAV/MET NUMBERS FOR
OVERNIGHT MINS.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
STRONG WARM AIR ADVECTION WILL BE PRESENT OVER WESTERN PORTIONS OF
THE FORECAST AREA BY AROUND 12Z. THIS MAY TRIGGER A FEW SHOWERS
OR THUNDERSTORMS DURING THE EARLY MORNING HOURS.
A BLAST OF VERY WARM AIR WILL ENTER THE REGION WITH SOUTHERN ZONES
PEAKING OUT AT OR ABOVE +20C AT 850MB. THIS WILL ALLOW MID/UPPER
90S TO SOUTHERN INTERIOR SECTIONS. WITH CURRENT DEW POINTS FORECAST
TO BE IN THE MID 60S IN THIS LOCATION TOMORROW AFTERNOON...EXPECT
HEAT INDEX VALUES TO BE CLOSE TO 100 DEGREES. CURRENT GRIDS ARE
FORECAST TO BE JUST BELOW THE HEAT ADVISORY CRITERIA FOR A FEW
HOURS TUESDAY AFTERNOON. THEREFORE...WILL NOT BE ISSUING HEAT
ADVISORIES AT THIS TIME.
A ROUND OF STRONG TO SEVERE STORMS IS EXPECT TO ROLL OUT OF
NORTHERN AREAS DURING THE MID/LATE AFTERNOON HOURS. SPC HAS US IN
SLIGHT RISK. WITH INSTABILITY VALUES INCREASING...EXPECT POSSIBLE
LARGE HAIL...DAMAGING WINDS AND LOCALLY VERY HEAVY RAINFALL. HAVE
ADDED THIS ENHANCED WORDING TO MUCH OF THE NORTHERN HALF OF THE
FORECAST AREA. TRICK WILL BE THE TIMING OF THE SURFACE COLD FRONT
AND ANY PRE-FRONTAL TROUGHS. DIRECTIONAL SHEAR ACROSS MUCH OF MAINE
WILL ALSO BE FAVORABLE FOR A FEW ISOLATED TORNADOES IF CONDITIONS
LINE UP JUST RIGHT WITH LOW LEVEL SOUTHERLY WINDS AND MID/UPPER
LEVEL WESTERLIES.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
MODEL DISCREPANCIES ARE THE KEY TO THE WEDNESDAY FORECAST. MODEL
TRENDS HAVE BEEN SLOWING THE SOUTHWARD PROGRESSION OF THE
FRONT...LEAVING THE SOUTHERN HALF OF NEW HAMPSHIRE AND FAR
SOUTHWESTERN MAINE SUSCEPTIBLE TO ANOTHER OPPORTUNITY FOR
THUNDERSTORMS ALONG THE FRONT WEDNESDAY AFTERNOON. AT THIS TIME
THERE IS STILL ENOUGH UNCERTAINTY NOT TO BITE ON ANY SEVERE
WEATHER POTENTIAL BUT IT BEARS WATCHING AS THIS WILL BE A POTENT
FRONT WITH A LOT OF HEATING OUT AHEAD OF IT.
BEYOND LINGERING SHOWERS ON WEDNESDAY NIGHT...THE FRONT CLEARS AND
HIGH PRESSURE BUILDS OVER THE AREA AS A COOL UPPER TROUGH CARVES
OUT OVER NEW ENGLAND AND THE CANADIAN MARITIMES. AS THE TROUGH
MOVES OFFSHORE ON SUNDAY...HEIGHTS AND TEMPERATURES RISE AS WILL
THE HUMIDITY INTO MONDAY...WITH ANOTHER DISTURBANCE APPROACHING BY
TUESDAY. A MIX OF THE HPC AND GRIDDED MOS GUIDANCE WAS USED FOR
THE MEDIUM RANGE FORECAST.
&&
.AVIATION /22Z MONDAY THROUGH SATURDAY/...
SHORT TERM...MAINLY VFR CONDITIONS THIS EVENING. HOWEVER THERE
WILL BE IFR CONDITIONS IN QUICK PASSING SHOWERS. PATCHY FOG WILL
DEVELOP AROUND MIDNIGHT. LOCALLY LIFR CONDITIONS IN STRONG STORMS
TUESDAY AFTERNOON AND EVENING...MAINLY OVER NORTHERN AREAS.
LONG TERM...ON WEDNESDAY...SOUTHERN MAINE AND SOUTHERN AND
CENTRAL NEW HAMPSHIRE ARE EXPECTED TO SEE ADDITIONAL PRECIPITATION
AND MVFR/IFR CONDITIONS AS THE FRONT SLOWLY SAGS THROUGH THE AREA.
HIGH PRESSURE BUILDS OVER THE AREA FOR VFR CLEAR CONDITIONS
THURSDAY THROUGH SATURDAY.
&&
.MARINE...
SHORT TERM...WEAK LOW PRESSURE MOVES OUT OF THE GULF OF MAINE
TONIGHT WITH LIGHT WINDS AND SEAS. WINDS INCREASE OUT OF THE SOUTH
ON TUESDAY AHEAD OF A COLD FRONT. GUSTS MAY APPROACH 25 KT BY
TUESDAY AFTERNOON.
LONG TERM...EXPECT THE SEAS TO SUBSIDE AND WINDS TO DIMINISH ON
WEDNESDAY WITH THE PASSAGE OF THE FRONT. WINDS AND SEAS RELAX EVEN
FURTHER LATE IN THE WEEK AS HIGH PRESSURE BUILDS IN.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
UPDATE...HANES
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
942 AM EDT SUN JUL 15 2012
.SYNOPSIS...
THE COMBINATION OF A MID-LEVEL DISTURBANCE CROSSING THE GREAT
LAKES AND A MOIST AIR MASS IN PLACE ACROSS THE UPPER OHIO VALLEY
WILL MAKE SHOWERS AND THUNDERSTORMS LIKELY BY THIS AFTERNOON. A
DRY START TO THE WEEK IS THEN EXPECTED AS HIGH PRESSURE ALOFT
APPROACHES FROM THE SOUTHWEST.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE TO REMOVE MENTION OF MORNING FOG.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES THE UPPER OHIO VALLEY
IN A SOUTHWESTERLY FLOW BETWEEN A RIDGE ACROSS THE CAROLINAS AND A
TROUGH ACROSS THE WESTERN GREAT LAKES. AT THE SURFACE, DISCERNIBLE
FRONTAL/PRESSURE FEATURES ARE LACKING WITH A BROAD AREA OF TDS IN
THE UPPER 60S TO LOWER 70S ACROSS THE REGION. A SATURATED
ATMOSPHERIC COLUMN REMAINS IN PLACE WITH PRECIPITABLE WATER VALUES
IN THE 1.8-2.0 INCH RANGE EARLY THIS MORNING. DESPITE ONLY WEAK
CAPE REMAINING, ABUNDANT MOISTURE IN PLACE IS ENOUGH TO SUPPORT
WIDELY SCATTERED SHOWERS MOVING ACROSS THE AREA.
THE SOUTHWESTERLY MID-LEVEL FLOW WILL BECOME MORE ZONAL TODAY AS
THE TROUGH CROSSES THE GREAT LAKES. 500MB HEIGHTS WILL FALL
SLIGHTLY AS THIS FEATURE PASSES NORTH OF THE AREA, PROVIDING
ENOUGH FORCING IN A MOIST AND UNSTABLE ENVIRONMENT TO CONTRIBUTE
TO THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS. COVERAGE OF
CONVECTION IS EXPECTED TO INCREASE THIS MORNING AS ELEVATED
INSTABILITY INCREASES FROM THE SOUTHWEST. EXPECT MOSTLY CLOUDY
SKIES AGAIN TODAY WITH ABUNDANT MOISTURE. FOR TEMPS, HIGHS ARE
CLOSEST TO MAV GUIDANCE, RANGING FROM THE UPPER 70S ALONG THE I-80
CORRIDOR AND EASTERN RIDGES TO THE MID 80S IN EASTERN OHIO.
PWAT VALUES NEAR 2 INCHES WITH DEEP MOISTURE IN PLACE ALONG WITH
MODERATE INSTABILITY WILL SUPPORT LOCALLY HEAVY DOWNPOURS TODAY.
STORM MOTION OF AROUND 30KTS ALONG WITH THE GROUND BEING
RELATIVELY DRY ACROSS MUCH OF THE AREA WILL BE LIMITING FACTORS
FOR A FLASH FLOODING THREAT TODAY. HOWEVER, IF MULTIPLE STORMS
TRAIN OVER AREAS, FLOODING COULD BECOME A THREAT. WITH 0-6KM BULK
SHEAR AROUND 30KTS, ITS NOT OF THE QUESTION THAT A FEW ISOLATED
STRONG TO SEVERE THUNDERSTORMS WILL DEVELOP THIS AFTERNOON INTO
THE EVENING WITH THE PRIMARY THREAT BEING OF GUSTY WINDS AIDED
BY MOISTURE LOADING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
THERE IS OPERATIONAL MODEL AGREEMENT THAT THE MID-LEVEL TROUGH
WILL SHIFT EAST OF THE AREA WITH THE FLOW BECOMING NORTHWESTERLY.
WITH DEEP LAYER MOISTURE ADVECTING EAST OF THE AREA, CONVECTION
WITH LOCALLY HEAVY DOWNPOURS WILL DIMINISH BY 06Z WITH POPS
DECREASING TO SCHC QUICKLY AND DRY BY MONDAY MORNING. A DRY LAYER
ABOVE 850MB ALONG WITH 500MB RIDGING BUILDING INTO THE OHIO VALLEY
WILL ALLOW FOR A MOSTLY DRY FORECAST THROUGH THE DAY MONDAY AND
INTO MONDAY NIGHT. MODERATE INSTABILITY MAY BE ENOUGH TO INITIATE
AN ISOLATED SHOWER OR THUNDERSTORM SOUTHEAST OF PITTSBURGH INTO
THE AFTERNOON.
HIGHS MONDAY ARE A MAV/MET BLEND, RANGING FROM THE MID TO UPPER
80S ACROSS THE AREA. WITH TDS IN THE MID TO UPPER 60S TONIGHT AND
MONDAY NIGHT, LOWS WILL RANGE FROM THE MID 60S ACROSS THE I-80
CORRIDOR TO NEAR 70 FOR THE PITTSBURGH METRO AND LOCATIONS
SOUTHWESTWARD.
ECMWF/GFS ARE IN AGREEMENT THAT THE 500MB RIDGE CENTERED ACROSS
THE TENNESSEE VALLEY WILL EDGE TOWARD THE UPPER OHIO VALLEY ON
TUESDAY. IN ADDITION, THE REGION WILL BE IN WARM AIR ADVECTION
AHEAD OF A COLD FRONT APPROACHING FROM THE NORTHWEST. WITH 850MB
TEMPS FORECAST TO WARM TO NEAR 20C BY TUESDAY AFTERNOON, THIS
SUPPORTS HIGHS IN THE LOWER 90S ACROSS LOWLAND AREAS. WITH WARMEST
TDS IN EASTERN OHIO, HEAT INDICES WILL APPROACH 100 AND A HEAT
ADVISORY MAY BE NEEDED FOR LOCATIONS ALONG AND WEST OF I-77.
TUESDAY WILL BE A WARM AND MUGGY NIGHT WITH TEMPS ONLY COOLING
INTO THE LOWER 70S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
GLOBAL MODEL AGREEMENT AND RUN-TO-RUN CONSISTENCY IS VERY GOOD ON
THE SOUTHWARD PROGRESSION OF A COLD FRONT ACROSS THE AREA ON
WEDNESDAY. THE GFS AND ECMWF BOTH DEPICT IT CLEARING VIRTUALLY ALL
OF THE FORECAST AREA SAVE FOR MAYBE THE FARTHEST SOUTHEASTERN
COUNTIES BY THURSDAY MORNING. BECAUSE OF THIS AND DUE TO A MUCH
DRIER COLUMN FORECAST TO INFILTRATE THE AREA AFTER THIS TIME
FRAME...THE FORECAST WAS DRIED OUT BEYOND WEDNESDAY NIGHT. THE
RESULTANT DEEP NORTHWESTERLY FLOW WILL BRING MUCH LESS HUMID
CONDITIONS INTO THE REGION...HOWEVER WITH 850 MB TEMPERATURES FROM
THE MODEL CONSENSUS STILL RUNNING IN THE MID TEENS...TEMPERATURES
ARE LIKELY TO REMAIN AT LEAST UP TOWARD NORMAL HIGHS FOR JULY.
FRIES
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
THUNDERSTORMS HAVE CLEARED ALL SITES TO THE NORTHEAST FOR THE
EVENING AS OF 0530Z. SOME SHOWER ACTIVITY CONTINUES TO DEVELOP OVER
EASTERN OHIO AND MOVE NORTHEASTWARD...BUT IT IS RATHER SCATTERED.
THIS WILL NOT BE CARRIED AT ANY PARTICULAR TERMINAL...HOWEVER
CONTINUED INPUT OF MOISTURE INTO THE LOWER LEVELS FROM ANY
ADDITIONAL SHOWERS WILL ONLY INCREASE THE LIKELIHOOD OF VISIBILITIES
STARTING TO SLIDE OFF WITHIN THE NEXT 1-3 HOURS. ALL SITES SHOULD GO
MVFR PER BOTH STATISTICAL GUIDANCE AND PER SUGGESTIONS FROM BUFKIT
DATA. SHOWERS WILL REDEVELOP BY LATE MORNING SUNDAY AGAIN AS THINGS
BEGIN TO DESTABILIZE...WHICH SHOULD ALLOW FOR FOG TO BREAKUP BY THAT
TIME. FRIES
OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...
WEAK RIDGING SHOULD PROVIDE GENERALLY VFR CONDITIONS MONDAY INTO
TUESDAY. A COLD FRONT WILL SAG SOUTHWARD ACROSS THE GREAT LAKES AND
THROUGH THE OHIO VALLEY TUESDAY NIGHT AND WEDNESDAY. RESTRICTIONS
CAN BE EXPECTED IN SCATTERED PREFRONTAL THUNDERSTORMS. PREVAILING
VFR WEATHER SHOULD RETURN BY THURSDAY AS A SURFACE HIGH BUILDS IN.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
636 AM EDT SUN JUL 15 2012
.SYNOPSIS...
THE COMBINATION OF A MID-LEVEL DISTURBANCE CROSSING THE GREAT
LAKES AND A MOIST AIR MASS IN PLACE ACROSS THE UPPER OHIO VALLEY
WILL MAKE SHOWERS AND THUNDERSTORMS LIKELY BY THIS AFTERNOON. A
DRY START TO THE WEEK IS THEN EXPECTED AS HIGH PRESSURE ALOFT
APPROACHES FROM THE SOUTHWEST.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES THE UPPER OHIO VALLEY
IN A SOUTHWESTERLY FLOW BETWEEN A RIDGE ACROSS THE CAROLINAS AND A
TROUGH ACROSS THE WESTERN GREAT LAKES. AT THE SURFACE, DISCERNIBLE
FRONTAL/PRESSURE FEATURES ARE LACKING WITH A BROAD AREA OF TDS IN
THE UPPER 60S TO LOWER 70S ACROSS THE REGION. A SATURATED
ATMOSPHERIC COLUMN REMAINS IN PLACE WITH PRECIPITABLE WATER VALUES
IN THE 1.8-2.0 INCH RANGE EARLY THIS MORNING. DESPITE ONLY WEAK
CAPE REMAINING, ABUNDANT MOISTURE IN PLACE IS ENOUGH TO SUPPORT
WIDELY SCATTERED SHOWERS MOVING ACROSS THE AREA.
THE SOUTHWESTERLY MID-LEVEL FLOW WILL BECOME MORE ZONAL TODAY AS
THE TROUGH CROSSES THE GREAT LAKES. 500MB HEIGHTS WILL FALL
SLIGHTLY AS THIS FEATURE PASSES NORTH OF THE AREA, PROVIDING
ENOUGH FORCING IN A MOIST AND UNSTABLE ENVIRONMENT TO CONTRIBUTE
TO THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS. COVERAGE OF
CONVECTION IS EXPECTED TO INCREASE THIS MORNING AS ELEVATED
INSTABILITY INCREASES FROM THE SOUTHWEST. EXPECT MOSTLY CLOUDY
SKIES AGAIN TODAY WITH ABUNDANT MOISTURE. FOR TEMPS, HIGHS ARE
CLOSEST TO MAV GUIDANCE, RANGING FROM THE UPPER 70S ALONG THE I-80
CORRIDOR AND EASTERN RIDGES TO THE MID 80S IN EASTERN OHIO.
PWAT VALUES NEAR 2 INCHES WITH DEEP MOISTURE IN PLACE ALONG WITH
MODERATE INSTABILITY WILL SUPPORT LOCALLY HEAVY DOWNPOURS TODAY.
STORM MOTION OF AROUND 30KTS ALONG WITH THE GROUND BEING
RELATIVELY DRY ACROSS MUCH OF THE AREA WILL BE LIMITING FACTORS
FOR A FLASH FLOODING THREAT TODAY. HOWEVER, IF MULTIPLE STORMS
TRAIN OVER AREAS, FLOODING COULD BECOME A THREAT. WITH 0-6KM BULK
SHEAR AROUND 30KTS, ITS NOT OF THE QUESTION THAT A FEW ISOLATED
STRONG TO SEVERE THUNDERSTORMS WILL DEVELOP THIS AFTERNOON INTO
THE EVENING WITH THE PRIMARY THREAT BEING OF GUSTY WINDS AIDED
BY MOISTURE LOADING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
THERE IS OPERATIONAL MODEL AGREEMENT THAT THE MID-LEVEL TROUGH
WILL SHIFT EAST OF THE AREA WITH THE FLOW BECOMING NORTHWESTERLY.
WITH DEEP LAYER MOISTURE ADVECTING EAST OF THE AREA, CONVECTION
WITH LOCALLY HEAVY DOWNPOURS WILL DIMINISH BY 06Z WITH POPS
DECREASING TO SCHC QUICKLY AND DRY BY MONDAY MORNING. A DRY LAYER
ABOVE 850MB ALONG WITH 500MB RIDGING BUILDING INTO THE OHIO VALLEY
WILL ALLOW FOR A MOSTLY DRY FORECAST THROUGH THE DAY MONDAY AND
INTO MONDAY NIGHT. MODERATE INSTABILITY MAY BE ENOUGH TO INITIATE
AN ISOLATED SHOWER OR THUNDERSTORM SOUTHEAST OF PITTSBURGH INTO
THE AFTERNOON.
HIGHS MONDAY ARE A MAV/MET BLEND, RANGING FROM THE MID TO UPPER
80S ACROSS THE AREA. WITH TDS IN THE MID TO UPPER 60S TONIGHT AND
MONDAY NIGHT, LOWS WILL RANGE FROM THE MID 60S ACROSS THE I-80
CORRIDOR TO NEAR 70 FOR THE PITTSBURGH METRO AND LOCATIONS
SOUTHWESTWARD.
ECMWF/GFS ARE IN AGREEMENT THAT THE 500MB RIDGE CENTERED ACROSS
THE TENNESSEE VALLEY WILL EDGE TOWARD THE UPPER OHIO VALLEY ON
TUESDAY. IN ADDITION, THE REGION WILL BE IN WARM AIR ADVECTION
AHEAD OF A COLD FRONT APPROACHING FROM THE NORTHWEST. WITH 850MB
TEMPS FORECAST TO WARM TO NEAR 20C BY TUESDAY AFTERNOON, THIS
SUPPORTS HIGHS IN THE LOWER 90S ACROSS LOWLAND AREAS. WITH WARMEST
TDS IN EASTERN OHIO, HEAT INDICES WILL APPROACH 100 AND A HEAT
ADVISORY MAY BE NEEDED FOR LOCATIONS ALONG AND WEST OF I-77.
TUESDAY WILL BE A WARM AND MUGGY NIGHT WITH TEMPS ONLY COOLING
INTO THE LOWER 70S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
GLOBAL MODEL AGREEMENT AND RUN-TO-RUN CONSISTENCY IS VERY GOOD ON
THE SOUTHWARD PROGRESSION OF A COLD FRONT ACROSS THE AREA ON
WEDNESDAY. THE GFS AND ECMWF BOTH DEPICT IT CLEARING VIRTUALLY ALL
OF THE FORECAST AREA SAVE FOR MAYBE THE FARTHEST SOUTHEASTERN
COUNTIES BY THURSDAY MORNING. BECAUSE OF THIS AND DUE TO A MUCH
DRIER COLUMN FORECAST TO INFILTRATE THE AREA AFTER THIS TIME
FRAME...THE FORECAST WAS DRIED OUT BEYOND WEDNESDAY NIGHT. THE
RESULTANT DEEP NORTHWESTERLY FLOW WILL BRING MUCH LESS HUMID
CONDITIONS INTO THE REGION...HOWEVER WITH 850 MB TEMPERATURES FROM
THE MODEL CONSENSUS STILL RUNNING IN THE MID TEENS...TEMPERATURES
ARE LIKELY TO REMAIN AT LEAST UP TOWARD NORMAL HIGHS FOR JULY.
FRIES
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
THUNDERSTORMS HAVE CLEARED ALL SITES TO THE NORTHEAST FOR THE
EVENING AS OF 0530Z. SOME SHOWER ACTIVITY CONTINUES TO DEVELOP OVER
EASTERN OHIO AND MOVE NORTHEASTWARD...BUT IT IS RATHER SCATTERED.
THIS WILL NOT BE CARRIED AT ANY PARTICULAR TERMINAL...HOWEVER
CONTINUED INPUT OF MOISTURE INTO THE LOWER LEVELS FROM ANY
ADDITIONAL SHOWERS WILL ONLY INCREASE THE LIKELIHOOD OF VISIBILITIES
STARTING TO SLIDE OFF WITHIN THE NEXT 1-3 HOURS. ALL SITES SHOULD GO
MVFR PER BOTH STATISTICAL GUIDANCE AND PER SUGGESTIONS FROM BUFKIT
DATA. SHOWERS WILL REDEVELOP BY LATE MORNING SUNDAY AGAIN AS THINGS
BEGIN TO DESTABILIZE...WHICH SHOULD ALLOW FOR FOG TO BREAKUP BY THAT
TIME. FRIES
OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...
WEAK RIDGING SHOULD PROVIDE GENERALLY VFR CONDITIONS MONDAY INTO
TUESDAY. A COLD FRONT WILL SAG SOUTHWARD ACROSS THE GREAT LAKES AND
THROUGH THE OHIO VALLEY TUESDAY NIGHT AND WEDNESDAY. RESTRICTIONS
CAN BE EXPECTED IN SCATTERED PREFRONTAL THUNDERSTORMS. PREVAILING
VFR WEATHER SHOULD RETURN BY THURSDAY AS A SURFACE HIGH BUILDS IN.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
430 AM EDT SUN JUL 15 2012
.SYNOPSIS...
THE COMBINATION OF A MID-LEVEL DISTURBANCE CROSSING THE GREAT
LAKES AND A MOIST AIR MASS IN PLACE ACROSS THE UPPER OHIO VALLEY
WILL MAKE SHOWERS AND THUNDERSTORMS LIKELY BY THIS AFTERNOON. A
DRY START TO THE WEEK IS THEN EXPECTED AS HIGH PRESSURE ALOFT
APPROACHES FROM THE SOUTHWEST.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES THE UPPER OHIO VALLEY
IN A SOUTHWESTERLY FLOW BETWEEN A RIDGE ACROSS THE CAROLINAS AND A
TROUGH ACROSS THE WESTERN GREAT LAKES. AT THE SURFACE, DISCERNIBLE
FRONTAL/PRESSURE FEATURES ARE LACKING WITH A BROAD AREA OF TDS IN
THE UPPER 60S TO LOWER 70S ACROSS THE REGION. A SATURATED
ATMOSPHERIC COLUMN REMAINS IN PLACE WITH PRECIPITABLE WATER VALUES
IN THE 1.8-2.0 INCH RANGE EARLY THIS MORNING. DESPITE ONLY WEAK
CAPE REMAINING, ABUNDANT MOISTURE IN PLACE IS ENOUGH TO SUPPORT
WIDELY SCATTERED SHOWERS MOVING ACROSS THE AREA.
THE SOUTHWESTERLY MID-LEVEL FLOW WILL BECOME MORE ZONAL TODAY AS
THE TROUGH CROSSES THE GREAT LAKES. 500MB HEIGHTS WILL FALL
SLIGHTLY AS THIS FEATURE PASSES NORTH OF THE AREA, PROVIDING
ENOUGH FORCING IN A MOIST AND UNSTABLE ENVIRONMENT TO CONTRIBUTE
TO THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS. COVERAGE OF
CONVECTION IS EXPECTED TO INCREASE THIS MORNING AS ELEVATED
INSTABILITY INCREASES FROM THE SOUTHWEST. EXPECT MOSTLY CLOUDY
SKIES AGAIN TODAY WITH ABUNDANT MOISTURE. FOR TEMPS, HIGHS ARE
CLOSEST TO MAV GUIDANCE, RANGING FROM THE UPPER 70S ALONG THE I-80
CORRIDOR AND EASTERN RIDGES TO THE MID 80S IN EASTERN OHIO.
PWAT VALUES NEAR 2 INCHES WITH DEEP MOISTURE IN PLACE ALONG WITH
MODERATE INSTABILITY WILL SUPPORT LOCALLY HEAVY DOWNPOURS TODAY.
STORM MOTION OF AROUND 30KTS ALONG WITH THE GROUND BEING
RELATIVELY DRY ACROSS MUCH OF THE AREA WILL BE LIMITING FACTORS
FOR A FLASH FLOODING THREAT TODAY. HOWEVER, IF MULTIPLE STORMS
TRAIN OVER AREAS, FLOODING COULD BECOME A THREAT. WITH 0-6KM BULK
SHEAR AROUND 30KTS, ITS NOT OF THE QUESTION THAT A FEW ISOLATED
STRONG TO SEVERE THUNDERSTORMS WILL DEVELOP THIS AFTERNOON INTO
THE EVENING WITH THE PRIMARY THREAT BEING OF GUSTY WINDS AIDED
BY MOISTURE LOADING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
THERE IS OPERATIONAL MODEL AGREEMENT THAT THE MID-LEVEL TROUGH
WILL SHIFT EAST OF THE AREA WITH THE FLOW BECOMING NORTHWESTERLY.
WITH DEEP LAYER MOISTURE ADVECTING EAST OF THE AREA, CONVECTION
WITH LOCALLY HEAVY DOWNPOURS WILL DIMINISH BY 06Z WITH POPS
DECREASING TO SCHC QUICKLY AND DRY BY MONDAY MORNING. A DRY LAYER
ABOVE 850MB ALONG WITH 500MB RIDGING BUILDING INTO THE OHIO VALLEY
WILL ALLOW FOR A MOSTLY DRY FORECAST THROUGH THE DAY MONDAY AND
INTO MONDAY NIGHT. MODERATE INSTABILITY MAY BE ENOUGH TO INITIATE
AN ISOLATED SHOWER OR THUNDERSTORM SOUTHEAST OF PITTSBURGH INTO
THE AFTERNOON.
HIGHS MONDAY ARE A MAV/MET BLEND, RANGING FROM THE MID TO UPPER
80S ACROSS THE AREA. WITH TDS IN THE MID TO UPPER 60S TONIGHT AND
MONDAY NIGHT, LOWS WILL RANGE FROM THE MID 60S ACROSS THE I-80
CORRIDOR TO NEAR 70 FOR THE PITTSBURGH METRO AND LOCATIONS
SOUTHWESTWARD.
ECMWF/GFS ARE IN AGREEMENT THAT THE 500MB RIDGE CENTERED ACROSS
THE TENNESSEE VALLEY WILL EDGE TOWARD THE UPPER OHIO VALLEY ON
TUESDAY. IN ADDITION, THE REGION WILL BE IN WARM AIR ADVECTION
AHEAD OF A COLD FRONT APPROACHING FROM THE NORTHWEST. WITH 850MB
TEMPS FORECAST TO WARM TO NEAR 20C BY TUESDAY AFTERNOON, THIS
SUPPORTS HIGHS IN THE LOWER 90S ACROSS LOWLAND AREAS. WITH WARMEST
TDS IN EASTERN OHIO, HEAT INDICES WILL APPROACH 100 AND A HEAT
ADVISORY MAY BE NEEDED FOR LOCATIONS ALONG AND WEST OF I-77.
TUESDAY WILL BE A WARM AND MUGGY NIGHT WITH TEMPS ONLY COOLING
INTO THE LOWER 70S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
A COLD FRONT IS PROGGED TO MOVE SLOWLY SOUTHWARD ACROSS THE GREAT
LAKES AND THROUGH THE UPPER OHIO VALLEY ON WEDNESDAY. SCATTERED
SHOWERS AND THUNDERSTORMS WILL ACCOMPANY THIS BOUNDARY THROUGH
WEDNESDAY EVENING. DRY CONDITIONS CAN BE EXPECTED THURSDAY THROUGH
SATURDAY AS SURFACE HIGH PRESSURE BUILDS IN ACROSS THE GREAT LAKES
AND INTO NEW ENGLAND.
STAYED CLOSE TO HPC NUMBERS WITH TEMPERATURES REMAINING BETWEEN 5
AND 10 DEGREES ABOVE NORMAL THROUGH WEDNESDAY NIGHT...THEN CLOSER TO
NORMAL FOR THE LATTER PART OF THE WEEK.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
THUNDERSTORMS HAVE CLEARED ALL SITES TO THE NORTHEAST FOR THE
EVENING AS OF 0530Z. SOME SHOWER ACTIVITY CONTINUES TO DEVELOP OVER
EASTERN OHIO AND MOVE NORTHEASTWARD...BUT IT IS RATHER SCATTERED.
THIS WILL NOT BE CARRIED AT ANY PARTICULAR TERMINAL...HOWEVER
CONTINUED INPUT OF MOISTURE INTO THE LOWER LEVELS FROM ANY
ADDITIONAL SHOWERS WILL ONLY INCREASE THE LIKELIHOOD OF VISIBILITIES
STARTING TO SLIDE OFF WITHIN THE NEXT 1-3 HOURS. ALL SITES SHOULD GO
MVFR PER BOTH STATISTICAL GUIDANCE AND PER SUGGESTIONS FROM BUFKIT
DATA. SHOWERS WILL REDEVELOP BY LATE MORNING SUNDAY AGAIN AS THINGS
BEGIN TO DESTABILIZE...WHICH SHOULD ALLOW FOR FOG TO BREAKUP BY THAT
TIME. FRIES
OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...
WEAK RIDGING SHOULD PROVIDE GENERALLY VFR CONDITIONS MONDAY INTO
TUESDAY. A COLD FRONT WILL SAG SOUTHWARD ACROSS THE GREAT LAKES AND
THROUGH THE OHIO VALLEY TUESDAY NIGHT AND WEDNESDAY. RESTRICTIONS
CAN BE EXPECTED IN SCATTERED PREFRONTAL THUNDERSTORMS. PREVAILING
VFR WEATHER SHOULD RETURN BY THURSDAY AS A SURFACE HIGH BUILDS IN.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
228 AM EDT SUN JUL 15 2012
.SYNOPSIS...
A LOW PRESSURE TROUGH ACROSS THE MISSISSIPPI VALLEY WILL CONTINUE
TO CHANNEL HUMID CONDITIONS NORTHWARD ACROSS THE UPPER OHIO VALLEY
TODAY, MAKING SHOWERS AND THUNDERSTORMS LIKELY. A DRY START TO THE
WEEK IS EXPECTED AS HIGH PRESSURE ALOFT APPROACHES FROM THE SOUTHWEST.
&&
.NEAR TERM /THROUGH TODAY/...
06Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED THIS
MORNING TO REMOVE THUNDER FROM THE FORECAST THROUGH 14Z.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES THE UPPER OHIO VALLEY
IN A SOUTHWESTERLY FLOW BETWEEN A RIDGE ACROSS THE CAROLINAS AND A
TROUGH ACROSS THE WESTERN GREAT LAKES. AT THE SURFACE, DISCERNIBLE
FRONTAL/PRESSURE FEATURES ARE LACKING WITH A BROAD AREA OF TDS IN
THE UPPER 60S TO LOWER 70S ACROSS THE REGION. A SATURATED
ATMOSPHERIC COLUMN REMAINS IN PLACE WITH PRECIPITABLE WATER VALUES
IN THE 1.8-2.0 INCH RANGE EARLY THIS MORNING. DESPITE ONLY WEAK
CAPE REMAINING, ABUNDANT MOISTURE IN PLACE IS ENOUGH TO SUPPORT
SCATTERED SHOWERS MOVING ACROSS THE AREA.
THE SOUTHWESTERLY MID-LEVEL FLOW WILL BECOME MORE ZONAL TODAY AS
THE TROUGH CROSSES THE GREAT LAKES. 500MB HEIGHTS WILL LOWER
SLIGHTLY AS THIS FEATURE PASSES NORTH OF THE AREA, PROVIDING
ENOUGH FORCING IN A MOIST AND UNSTABLE ENVIRONMENT TO CONTRIBUTE
TO THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS. COVERAGE OF
CONVECTION IS EXPECTED TO INCREASE THIS MORNING AS ELEVATED
INSTABILITY INCREASES FROM THE SOUTHWEST. PWAT VALUES NEAR 2
INCHES WITH DEEP MOISTURE IN PLACE ALONG WITH MODERATE INSTABILITY
WILL SUPPORT LOCALLY HEAVY DOWNPOURS. STORM MOTION OF AROUND 30KTS
ALONG WITH THE GROUND BEING RELATIVELY DRY ACROSS MUCH OF THE AREA
WILL CONTRIBUTE TO LIMIT THE FLASH FLOODING THREAT TODAY, SO NO
MENTION IN THE HWO AT TIME. HOWEVER, IF MULTIPLE STORMS TRAIN OVER
AREAS WHICH BECOME SATURATED, FLOODING COULD BECOME A THREAT. FOR
TEMPS, HIGHS ARE CLOSEST TO MAV GUIDANCE, RANGING FROM THE LOWER
TO MID 80S ACROSS THE UPPER OHIO VALLEY.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM MONDAY/...
THERE IS OPERATIONAL MODEL AGREEMENT THAT THE MID-LEVEL TROUGH
WILL SHIFT EAST OF THE AREA, WITH THE FLOW BECOMING NORTHWESTERLY.
WITH DEEP LAYER MOISTURE ADVECTING EAST OF THE AREA, THIS WILL
DECREASE POPS TO SCHC QUICKLY OVERNIGHT AND DRY BY MONDAY MORNING.
A DRY LAYER ABOVE 850MB ALONG WITH 500MB RIDGING BUILDING INTO THE
OHIO VALLEY WILL ALLOW FOR A DRY FORECAST THROUGH THE DAY MONDAY.
HIGHS ARE A MAV/MET BLEND, RANGING FROM THE MID TO UPPER 80S
ACROSS THE AREA.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
A COLD FRONT IS PROGGED TO MOVE SLOWLY SOUTHWARD ACROSS THE GREAT
LAKES AND THROUGH THE UPPER OHIO VALLEY TUESDAY NIGHT AND
WEDNESDAY. SCATTERED SHOWERS AND THUNDERSTORMS WILL ACCOMPANY THIS
BOUNDARY THROUGH WEDNESDAY EVENING. DRY CONDITIONS CAN BE EXPECTED
THURSDAY THROUGH SATURDAY AS SURFACE HIGH PRESSURE BUILDS IN ACROSS
THE GREAT LAKES AND INTO NEW ENGLAND.
STAYED CLOSE TO HPC NUMBERS WITH TEMPERATURES REMAINING BETWEEN 5
AND 10 DEGREES ABOVE NORMAL THROUGH WEDNESDAY NIGHT...THEN CLOSER TO
NORMAL FOR THE LATTER PART OF THE WEEK.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
THUNDERSTORMS HAVE CLEARED ALL SITES TO THE NORTHEAST FOR THE
EVENING AS OF 0530Z. SOME SHOWER ACTIVITY CONTINUES TO DEVELOP OVER
EASTERN OHIO AND MOVE NORTHEASTWARD...BUT IT IS RATHER SCATTERED.
THIS WILL NOT BE CARRIED AT ANY PARTICULAR TERMINAL...HOWEVER
CONTINUED INPUT OF MOISTURE INTO THE LOWER LEVELS FROM ANY
ADDITIONAL SHOWERS WILL ONLY INCREASE THE LIKELIHOOD OF VISIBILITIES
STARTING TO SLIDE OFF WITHIN THE NEXT 1-3 HOURS. ALL SITES SHOULD GO
MVFR PER BOTH STATISTICAL GUIDANCE AND PER SUGGESTIONS FROM BUFKIT
DATA. SHOWERS WILL REDEVELOP BY LATE MORNING SUNDAY AGAIN AS THINGS
BEGIN TO DESTABILIZE...WHICH SHOULD ALLOW FOR FOG TO BREAKUP BY THAT
TIME. FRIES
OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...
WEAK RIDGING SHOULD PROVIDE GENERALLY VFR CONDITIONS MONDAY INTO
TUESDAY. A COLD FRONT WILL SAG SOUTHWARD ACROSS THE GREAT LAKES AND
THROUGH THE OHIO VALLEY TUESDAY NIGHT AND WEDNESDAY. RESTRICTIONS
CAN BE EXPECTED IN SCATTERED PREFRONTAL THUNDERSTORMS. PREVAILING
VFR WEATHER SHOULD RETURN BY THURSDAY AS A SURFACE HIGH BUILDS IN.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
145 PM EDT SUN JUL 15 2012
.UPDATE...
ISSUED AT 1119 AM EDT SUN JUL 15 2012
MORNING UPDATE MAINLY DEALS WITH TWEAKS TO THE FOG OVER LK SUPERIOR
AND CLOUD COVER THIS AFTN OVER INTERIOR LOCATIONS. FOR THE
FOG...EXTENDED THE DENSE FOG ADVY FOR NORTHERN AREAS THROUGH THIS
AFTN DUE TO RECENT WEBCAMS ALONG THE NRN KEWEENAW SHORELINE SHOWING
DENSE FOG AT THIS HOUR. FARTHER SOUTH AND EAST...WEBCAMS AND SHIP
OBS THIS MORNING SHOWING THE EXPANSE OF CLOUDS OVER THE SE LK
SUPERIOR MAINLY IN THE FORM OF LOW STRATUS. THUS...WILL LET THAT
ADVY EXPIRE AT NOON.
HIGH RES MODELS ARE ALL SHOWING DIURNAL CU AND LIGHT SHOWERS
DEVELOPING OVER THE WRN/CNTRL CWA AWAY FROM THE LK BREEZES OFF LK
SUPERIOR. AREAS FROM WRN LK SUPERIOR TO THE THUNDER BAY AND N SAW
SOME SCATTERED ACCAS EARLY THIS MORNING...WHICH SEEMS TO BE JUST E
OF THE VERY DRY AIR ON THE 12Z KINL SOUNDING. BUT WITH THE SLOW
LLVL WINDS NOT PUSHING THE DRY AIR E VERY QUICKLY...THINKING THE
LINGERING LLVL MOISTURE WILL BE ENOUGH TO DEVELOP A LARGER AREA OF
CU THAN PREVIOUSLY THOUGHT. THEREFORE...BUMPED SKIES UP TO PARTLY
CLOUDY FOR MUCH OF THE INTERIOR W AND CNTRL. SINCE WEAK
SHORTWAVE ENERGY WILL TRY TO WORK INTO THE AREA THIS AFTN FROM
MORNING SHOWERS IN NW MN...THAT MAY BE ENOUGH TO HELP PRODUCE AN
ISOLATED SHOWER OR TWO. WITH ALL OF THE HIGH RES MODELS AND THE NEW
12Z NAM KICKING OFF SHOWERS...EVEN THOUGH THEY MAY BE
OVERDOING THE LLVL TD VALUES SOME...WILL INTRODUCE THEM AROUND 18Z
OVER ERN ONTONAGON/GOGEBIC COUNTIES AND THEN DRIFT SE BEFORE
DIMINISHING IN THE LATE AFTN. SINCE THERE APPEARS TO BE PLENTY OF
DRY AIR ABOVE H750...WILL KEEP THUNDER MENTION OUT AS THIS WILL
LIKELY LIMIT CLOUD DEPTH TO A FEW KFT AND MAY EVEN HOLD OFF SHOWER
DEVELOPMENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 520 AM EDT SUN JUL 15 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW TROF JUST E OF THE FCST
AREA. SHRA/TSRA THAT ACCOMPANIED THE TROF ACROSS THE AREA YESTERDAY
HAVE RECENTLY EXITED THE SE PORTION OF THE FCST AREA. IN ITS WAKE...
CALM WIND/CLEARING SKIES AND MOISTURE FROM YESTERDAY`S RAINFALL HAS
LED TO SOME FOG DEVELOPMENT. FOG WILL QUICKLY BURN OFF WITHIN A
COUPLE HRS AFTER SUNRISE. UPSTREAM...A MID LEVEL RIDGE IS NOSING
INTO THE DAKOTAS/WRN MN. AS THE RIDGE SHIFTS E TODAY...UPPER MI WILL
FALL UNDER HEIGHT RISES/DEEP LAYER QVECTOR DIVERGENCE. MUCH DRIER
AIR...MAINLY IN THE MID LEVELS PER UPSTREAM 00Z KINL/CWPL
SOUNDINGS...WILL WORK AGAINST ANY AFTN CONVECTIVE DEVELOPMENT
DESPITE LAKE BREEZES PROVIDING LOW-LEVEL FORCING. THE K-INDEX ON THE
00Z CWPL/KINL SOUNDINGS WAS -11/-14C RESPECTIVELY DUE TO VERY DRY
AIR AROUND 700MB (DWPT DEPRESSIONS WERE IN EXCESS OF 40C). SO...
GOING DRY FCST APPEARS ON TRACK DESPITE SOME HIGH RES GUIDANCE
CONTINUING TO SHOW ISOLD CONVECTION OVER THE SCNTRL THIS AFTN.
MIXING TO AROUND 800MB ON FCST SOUNDINGS SUPPORTS MAX TEMPS UPWARDS
OF AROUND 90F. LIGHT GRADIENT WIND WILL ALLOW LAKE BREEZES OFF
LAKE SUPERIOR AND LAKE MICHIGAN TO PROVIDE SOME COOLING LAKESIDE.
SHORTWAVE ENERGY EJECTING FROM THE TROF CURRENTLY OVER THE WRN
STATES WILL HEAD INTO SCNTRL CANADA TONIGHT. IN RESPONSE...LOW-LEVEL
JET WILL INCREASE TO 45-50KT INTO THE NRN PLAINS. THIS WILL LIKELY
SUPPORT A CLUSTER OF SHRA/TSRA ON THE NOSE OF THE LOW-LEVEL JET AND
ALONG EDGE OF CAP ACROSS ND INTO SRN MANITOBA/NRN MN AND NRN
ONTARIO. AT THIS TIME...IT STILL APPEARS LOW-LEVEL JET WILL BE W OF
THE AREA AT 12Z MON...SO DO NOT ANTICIPATE ANY CONVECTION LATE
TONIGHT...EXCEPT POSSIBLY OVER NW LAKE SUPERIOR/ISLE ROYALE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 520 AM EDT SUN JUL 15 2012
BY 12Z MONDAY THE FRONTAL BOUNDARY WOULD BE ACROSS LAKE SUPERIOR
/AS A WARM FRONT/...STRETCHING FROM THE SFC LOW SET UP FROM NW MN TO
CENTRAL SD. DEPENDING ON THE AMOUNT OF MIXING /UP TO AROUND 800MB AT
SAW/ A FEW GUSTS OF 30 TO 35KTS COULD BE POSSIBLE FROM LATE MORNING
THROUGH THE REMAINDER OF THE DAYTIME HOURS. IF CLOUD COVER DOES NOT
INHIBIT MIXING...THESE STRONGER GUSTS COULD BE POSSIBLE ACROSS THE
DOWNSLOPE LOCATIONS NEAR LAKE SUPERIOR GIVEN THE STRENGTHENING SW
FLOW. AS FOR THE OFFICIAL FCST...HAVE INCREASED WINDS QUITE A BIT
FROM THE PREVIOUS FORECAST...WITH GUSTS OF 20-25KTS ACROSS MUCH OF
THE CWA BY MID AFTERNOON.
THE RECORD HIGH TEMP FOR MONDAY AT WFO MQT IS 95 DEGREES...WHICH MAY
BE BROKEN BY THE END OF THE DAY. CURRENTLY GOING ONLY A COUPLE OF
DEGREES COOLER THAN THIS RECORD...WITH 850MB TEMPS OF 22-24C
ALLOWING SEVERAL SITES ACROSS THE INTERIOR W HALF OF UPPER MI
REACHING 95 OR ABOVE.
THE SFC LOW SHOULD PUSH ACROSS THE AREA MONDAY AFTERNOON
THROUGH TUESDAY NIGHT. THE TRACK IS STILL UNCERTAIN...WITH THE
14/18Z GFS AND 15/00Z NAM PUSHING THE SFC LOW ACROSS THE KEWEENAW
PENINSULA AND ACROSS LAKE SUPERIOR BY EARLY MONDAY EVENING. THE
FARTHER SOUTH 14/12Z ECMWF INDICATES A BROADER LOW...STRETCHING
ACROSS CENTRAL AND SOUTHERN UPPER MI MONDAY NIGHT. THE 14/12Z
CANADIAN IS BEYOND CONSENSUS FROM MONDAY AFTERNOON ON...TRACKING THE
SFC LOW ACROSS ONTARIO AND N LAKE SUPERIOR...AND WILL NOT BE USED IN
THIS FORECAST UNTIL IT MOVES BACK IN LINE WITH THE REMAINDER OF
AVAILABLE GUIDANCE WEDNESDAY MORNING.
HIGH PRESSURE OVER CENTRAL CANADA TUESDAY MORNING WILL SLOWLY SHIFT
SE ACROSS LAKE SUPERIOR AND UPPER MI TUESDAY THROUGH THURSDAY. THE
COOLEST AFTERNOON TEMPS LOOK TO BE WEDNESDAY...TOPPING OUT IN THE
70S...COOLEST NEAR LAKE SUPERIOR AS DRY COOL AIR REMAINS. 850MB
TEMPS WEDNESDAY WILL BE A COOL 10-12C. THE FCST FOR THE CWA WILL
REMAIN DRY TUESDAY NIGHT THROUGH FRIDAY NIGHT. EXPECT THE SFC HIGH
TO DRIFT E TO THE LOWER GREAT LAKES AND W QUEBEC BY DAYBREAK FRIDAY
AND THE NEW ENGLAND COAST FRIDAY NIGHT...WITH A RIDGE REMAINING
ACROSS THE UPPER GREAT LAKES REGION.
A RELATIVELY WEAK SFC LOW STRETCHING FROM CENTRAL CANADA THROUGH THE
CENTRAL PLAINS LOOKS TO BECOME BETTER ORGANIZED TO OUR W SATURDAY
NIGHT...AS A SERIES OF DISTURBANCES NEAR FROM W AND CENTRAL CANADA
AS 500MB RIDGE BECOMES SUPPRESSED ACROSS THE CENTRAL AND SOUTHERN
PLAINS. KEPT CHANCE POPS FOR SATURDAY...ALTHOUGH CONFIDENCE IS
MODERATE TO LOW FOR SPECIFICS THAT FAR OUT IN THIS FCST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 144 PM EDT SUN JUL 15 2012
MAINLY VFR CONDITIONS THROUGH THE PERIOD...AS THE DEVELOPING WARM
FRONT TONIGHT IS EXPECTED TO STAY TO THE N OF THE AREA.
THEREFORE...ALL OF THE ASSOCIATED CONVECTION SHOULD REMAIN OVER NRN
LK SUPERIOR OR SRN ONTARIO.
HAVE SOME CONCERN WITH FOG/STRATUS OVER LK SUPERIOR AND IT/S
POSSIBLE EFFECT ON KCMX/KIWD. CURRENT THINKING IS THAT IT SHOULDN/T
AFFECT KIWD DO TO INCREASING SWRLY FLOW TONIGHT. KCMX ON THE
OTHERHAND IS TRICKY. WITH WINDS BECOMING ERLY THIS EVENING AND LOSS
OF DIURNAL HEATING...COULD SEE THE FOG/STRATUS OVER LK SUPERIOR MOVE
IN AND QUICKLY BRING CIGS/VSBYS DONE. INDICATIONS ARE THAT IT IS A
STRATUS DECK...BUT THE LIGHT UPSLOPE FLOW WOULD HELP VSBYS GO DOWN.
DON/T HAVE ENOUGH CONFIDENCE TO HIT THE LOW CLOUDS/VSBYS HARD...SO
WILL MENTION OF MVFR VSBY AND SCT003 FOR NOW...BUT THINKING THAT
WILL LIKELY NEED TO BE DROPPED TO ALT LANDING MINS.
FINALLY...COULD GET QUITE GUSTY...TO 35KTS...OUT OF THE SSW AT THE
END OF THE TAF PERIOD AND FOR THE REST OF THE AFTN TOMORROW FOR KIWD
AND POTENTIALLY KCMX.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 520 AM EDT SUN JUL 15 2012
BIGGEST CONCERN IN THE SHORT TERM WILL BE FOG. 11-3.9MICRON
SATELLITE IMAGERY INDICATES FOG (PROBABLY NOT STRATUS) EXPANDING S
AND E FROM NCNTRL LAKE SUPERIOR. MORE FOG MAY BE DEVELOPING FROM
KEWEENAW BAY TOWARD MARQUETTE/MUNISING. WITH DEVELOPING MESO HIGH
PRES OVER THE LAKE TODAY...IT`S QUITE POSSIBLE FOG MAY END UP
SPREADING TO THE SHORELINES AROUND THE ENTIRE LAKE TODAY. ALWAYS
DIFFICULT TO FCST MARINE FOG...SO TRENDS WILL NEED TO MONITORED
CLOSELY TODAY FOR MOVEMENT/DEVELOPMENT/DISSIPATION OF FOG. ONCE
DAYLIGHT ARRIVES...VIS SATELLITE IMAGERY WILL PROVIDE A BETTER LOOK
AT HOW THE FOG IS EVOLVING. QUITE POSSIBLE DENSE FOG ADVY MAY NEED
TO BE ISSUED. FOR NOW...CARRIED FOG MENTION THRU EARLY AFTN OVER
MAINLY CNTRL AND ERN LAKE SUPERIOR.
OTHERWISE...WITH HIGH PRES DEVELOPING OVER LAKE SUPERIOR TODAY...
WINDS WILL BE UNDER 15KT. ALTHOUGH WINDS WILL BECOME S-SE TONIGHT IN
ADVANCE OF APPROACHING LOW PRES...SPEEDS SHOULD REMAIN 15KT OR LESS.
THERE IS SOME UNCERTAINTY IN WHERE WARM FRONT ASSOCIATED WITH THE
LOW WILL BE POSITIONED MON. AT THIS TIME...IT APPEARS THAT AT LEAST
SRN PORTIONS OF THE LAKE WILL SEE INCREASING S-SW WINDS MON UPWARDS
OF 20KT AS WARM FRONT DRIFTS N. AS LOW PASSES ACROSS THE AREA MON
NIGHT...A COLD FRONT WILL PUSH S...BRINGING A SHIFT TO NORTHERLY
WINDS UPWARDS OF 20KT INTO TUE MORNING. HIGH PRES WILL THEN BUILD
INTO THE UPPER GREAT LAKES DURING THE MIDWEEK PERIOD...RESULTING IN
WINDS UNDER 20KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 6 PM EDT THIS EVENING FOR LSZ243>245-
263-264-266.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...SRF
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...SRF
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1121 AM EDT SUN JUL 15 2012
.UPDATE...
ISSUED AT 1119 AM EDT SUN JUL 15 2012
MORNING UPDATE MAINLY DEALS WITH TWEAKS TO THE FOG OVER LK SUPERIOR
AND CLOUD COVER THIS AFTN OVER INTERIOR LOCATIONS. FOR THE
FOG...EXTENDED THE DENSE FOG ADVY FOR NORTHERN AREAS THROUGH THIS
AFTN DUE TO RECENT WEBCAMS ALONG THE NRN KEWEENAW SHORELINE SHOWING
DENSE FOG AT THIS HOUR. FARTHER SOUTH AND EAST...WEBCAMS AND SHIP
OBS THIS MORNING SHOWING THE EXPANSE OF CLOUDS OVER THE SE LK
SUPERIOR MAINLY IN THE FORM OF LOW STRATUS. THUS...WILL LET THAT
ADVY EXPIRE AT NOON.
HIGH RES MODELS ARE ALL SHOWING DIURNAL CU AND LIGHT SHOWERS
DEVELOPING OVER THE WRN/CNTRL CWA AWAY FROM THE LK BREEZES OFF LK
SUPERIOR. AREAS FROM WRN LK SUPERIOR TO THE THUNDER BAY AND N SAW
SOME SCATTERED ACCAS EARLY THIS MORNING...WHICH SEEMS TO BE JUST E
OF THE VERY DRY AIR ON THE 12Z KINL SOUNDING. BUT WITH THE SLOW
LLVL WINDS NOT PUSHING THE DRY AIR E VERY QUICKLY...THINKING THE
LINGERING LLVL MOISTURE WILL BE ENOUGH TO DEVELOP A LARGER AREA OF
CU THAN PREVIOUSLY THOUGHT. THEREFORE...BUMPED SKIES UP TO PARTLY
CLOUDY FOR MUCH OF THE INTERIOR W AND CNTRL. SINCE WEAK
SHORTWAVE ENERGY WILL TRY TO WORK INTO THE AREA THIS AFTN FROM
MORNING SHOWERS IN NW MN...THAT MAY BE ENOUGH TO HELP PRODUCE AN
ISOLATED SHOWER OR TWO. WITH ALL OF THE HIGH RES MODELS AND THE NEW
12Z NAM KICKING OFF SHOWERS...EVEN THOUGH THEY MAY BE
OVERDOING THE LLVL TD VALUES SOME...WILL INTRODUCE THEM AROUND 18Z
OVER ERN ONTONAGON/GOGEBIC COUNTIES AND THEN DRIFT SE BEFORE
DIMINISHING IN THE LATE AFTN. SINCE THERE APPEARS TO BE PLENTY OF
DRY AIR ABOVE H750...WILL KEEP THUNDER MENTION OUT AS THIS WILL
LIKELY LIMIT CLOUD DEPTH TO A FEW KFT AND MAY EVEN HOLD OFF SHOWER
DEVELOPMENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 520 AM EDT SUN JUL 15 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW TROF JUST E OF THE FCST
AREA. SHRA/TSRA THAT ACCOMPANIED THE TROF ACROSS THE AREA YESTERDAY
HAVE RECENTLY EXITED THE SE PORTION OF THE FCST AREA. IN ITS WAKE...
CALM WIND/CLEARING SKIES AND MOISTURE FROM YESTERDAY`S RAINFALL HAS
LED TO SOME FOG DEVELOPMENT. FOG WILL QUICKLY BURN OFF WITHIN A
COUPLE HRS AFTER SUNRISE. UPSTREAM...A MID LEVEL RIDGE IS NOSING
INTO THE DAKOTAS/WRN MN. AS THE RIDGE SHIFTS E TODAY...UPPER MI WILL
FALL UNDER HEIGHT RISES/DEEP LAYER QVECTOR DIVERGENCE. MUCH DRIER
AIR...MAINLY IN THE MID LEVELS PER UPSTREAM 00Z KINL/CWPL
SOUNDINGS...WILL WORK AGAINST ANY AFTN CONVECTIVE DEVELOPMENT
DESPITE LAKE BREEZES PROVIDING LOW-LEVEL FORCING. THE K-INDEX ON THE
00Z CWPL/KINL SOUNDINGS WAS -11/-14C RESPECTIVELY DUE TO VERY DRY
AIR AROUND 700MB (DWPT DEPRESSIONS WERE IN EXCESS OF 40C). SO...
GOING DRY FCST APPEARS ON TRACK DESPITE SOME HIGH RES GUIDANCE
CONTINUING TO SHOW ISOLD CONVECTION OVER THE SCNTRL THIS AFTN.
MIXING TO AROUND 800MB ON FCST SOUNDINGS SUPPORTS MAX TEMPS UPWARDS
OF AROUND 90F. LIGHT GRADIENT WIND WILL ALLOW LAKE BREEZES OFF
LAKE SUPERIOR AND LAKE MICHIGAN TO PROVIDE SOME COOLING LAKESIDE.
SHORTWAVE ENERGY EJECTING FROM THE TROF CURRENTLY OVER THE WRN
STATES WILL HEAD INTO SCNTRL CANADA TONIGHT. IN RESPONSE...LOW-LEVEL
JET WILL INCREASE TO 45-50KT INTO THE NRN PLAINS. THIS WILL LIKELY
SUPPORT A CLUSTER OF SHRA/TSRA ON THE NOSE OF THE LOW-LEVEL JET AND
ALONG EDGE OF CAP ACROSS ND INTO SRN MANITOBA/NRN MN AND NRN
ONTARIO. AT THIS TIME...IT STILL APPEARS LOW-LEVEL JET WILL BE W OF
THE AREA AT 12Z MON...SO DO NOT ANTICIPATE ANY CONVECTION LATE
TONIGHT...EXCEPT POSSIBLY OVER NW LAKE SUPERIOR/ISLE ROYALE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 520 AM EDT SUN JUL 15 2012
BY 12Z MONDAY THE FRONTAL BOUNDARY WOULD BE ACROSS LAKE SUPERIOR
/AS A WARM FRONT/...STRETCHING FROM THE SFC LOW SET UP FROM NW MN TO
CENTRAL SD. DEPENDING ON THE AMOUNT OF MIXING /UP TO AROUND 800MB AT
SAW/ A FEW GUSTS OF 30 TO 35KTS COULD BE POSSIBLE FROM LATE MORNING
THROUGH THE REMAINDER OF THE DAYTIME HOURS. IF CLOUD COVER DOES NOT
INHIBIT MIXING...THESE STRONGER GUSTS COULD BE POSSIBLE ACROSS THE
DOWNSLOPE LOCATIONS NEAR LAKE SUPERIOR GIVEN THE STRENGTHENING SW
FLOW. AS FOR THE OFFICIAL FCST...HAVE INCREASED WINDS QUITE A BIT
FROM THE PREVIOUS FORECAST...WITH GUSTS OF 20-25KTS ACROSS MUCH OF
THE CWA BY MID AFTERNOON.
THE RECORD HIGH TEMP FOR MONDAY AT WFO MQT IS 95 DEGREES...WHICH MAY
BE BROKEN BY THE END OF THE DAY. CURRENTLY GOING ONLY A COUPLE OF
DEGREES COOLER THAN THIS RECORD...WITH 850MB TEMPS OF 22-24C
ALLOWING SEVERAL SITES ACROSS THE INTERIOR W HALF OF UPPER MI
REACHING 95 OR ABOVE.
THE SFC LOW SHOULD PUSH ACROSS THE AREA MONDAY AFTERNOON
THROUGH TUESDAY NIGHT. THE TRACK IS STILL UNCERTAIN...WITH THE
14/18Z GFS AND 15/00Z NAM PUSHING THE SFC LOW ACROSS THE KEWEENAW
PENINSULA AND ACROSS LAKE SUPERIOR BY EARLY MONDAY EVENING. THE
FARTHER SOUTH 14/12Z ECMWF INDICATES A BROADER LOW...STRETCHING
ACROSS CENTRAL AND SOUTHERN UPPER MI MONDAY NIGHT. THE 14/12Z
CANADIAN IS BEYOND CONSENSUS FROM MONDAY AFTERNOON ON...TRACKING THE
SFC LOW ACROSS ONTARIO AND N LAKE SUPERIOR...AND WILL NOT BE USED IN
THIS FORECAST UNTIL IT MOVES BACK IN LINE WITH THE REMAINDER OF
AVAILABLE GUIDANCE WEDNESDAY MORNING.
HIGH PRESSURE OVER CENTRAL CANADA TUESDAY MORNING WILL SLOWLY SHIFT
SE ACROSS LAKE SUPERIOR AND UPPER MI TUESDAY THROUGH THURSDAY. THE
COOLEST AFTERNOON TEMPS LOOK TO BE WEDNESDAY...TOPPING OUT IN THE
70S...COOLEST NEAR LAKE SUPERIOR AS DRY COOL AIR REMAINS. 850MB
TEMPS WEDNESDAY WILL BE A COOL 10-12C. THE FCST FOR THE CWA WILL
REMAIN DRY TUESDAY NIGHT THROUGH FRIDAY NIGHT. EXPECT THE SFC HIGH
TO DRIFT E TO THE LOWER GREAT LAKES AND W QUEBEC BY DAYBREAK FRIDAY
AND THE NEW ENGLAND COAST FRIDAY NIGHT...WITH A RIDGE REMAINING
ACROSS THE UPPER GREAT LAKES REGION.
A RELATIVELY WEAK SFC LOW STRETCHING FROM CENTRAL CANADA THROUGH THE
CENTRAL PLAINS LOOKS TO BECOME BETTER ORGANIZED TO OUR W SATURDAY
NIGHT...AS A SERIES OF DISTURBANCES NEAR FROM W AND CENTRAL CANADA
AS 500MB RIDGE BECOMES SUPPRESSED ACROSS THE CENTRAL AND SOUTHERN
PLAINS. KEPT CHANCE POPS FOR SATURDAY...ALTHOUGH CONFIDENCE IS
MODERATE TO LOW FOR SPECIFICS THAT FAR OUT IN THIS FCST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 749 AM EDT SUN JUL 15 2012
FOG WHICH HAS LED TO HIGHLY VARIABLE VIS/CIGS OVERNIGHT WILL BURN
OFF OVER THE NEXT HR OR TWO...LEAVING VFR CONDITIONS TO PREVAIL
TODAY AND TONIGHT AT KIWD/KCMX/KSAW. THERE IS A SMALL POTENTIAL FOR
FOG TO REDEVELOP TONIGHT...BUT A SLOW INCREASE IN NEAR SFC WINDS WILL
WORK TO LIMIT POTENTIAL. ALSO...SOIL MOISTURE WHICH PLAYED A ROLE IN
FOG DEVELOPMENT OVERNIGHT WILL HAVE A CHANCE TO DRY OUT TODAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 520 AM EDT SUN JUL 15 2012
BIGGEST CONCERN IN THE SHORT TERM WILL BE FOG. 11-3.9MICRON
SATELLITE IMAGERY INDICATES FOG (PROBABLY NOT STRATUS) EXPANDING S
AND E FROM NCNTRL LAKE SUPERIOR. MORE FOG MAY BE DEVELOPING FROM
KEWEENAW BAY TOWARD MARQUETTE/MUNISING. WITH DEVELOPING MESO HIGH
PRES OVER THE LAKE TODAY...IT`S QUITE POSSIBLE FOG MAY END UP
SPREADING TO THE SHORELINES AROUND THE ENTIRE LAKE TODAY. ALWAYS
DIFFICULT TO FCST MARINE FOG...SO TRENDS WILL NEED TO MONITORED
CLOSELY TODAY FOR MOVEMENT/DEVELOPMENT/DISSIPATION OF FOG. ONCE
DAYLIGHT ARRIVES...VIS SATELLITE IMAGERY WILL PROVIDE A BETTER LOOK
AT HOW THE FOG IS EVOLVING. QUITE POSSIBLE DENSE FOG ADVY MAY NEED
TO BE ISSUED. FOR NOW...CARRIED FOG MENTION THRU EARLY AFTN OVER
MAINLY CNTRL AND ERN LAKE SUPERIOR.
OTHERWISE...WITH HIGH PRES DEVELOPING OVER LAKE SUPERIOR TODAY...
WINDS WILL BE UNDER 15KT. ALTHOUGH WINDS WILL BECOME S-SE TONIGHT IN
ADVANCE OF APPROACHING LOW PRES...SPEEDS SHOULD REMAIN 15KT OR LESS.
THERE IS SOME UNCERTAINTY IN WHERE WARM FRONT ASSOCIATED WITH THE
LOW WILL BE POSITIONED MON. AT THIS TIME...IT APPEARS THAT AT LEAST
SRN PORTIONS OF THE LAKE WILL SEE INCREASING S-SW WINDS MON UPWARDS
OF 20KT AS WARM FRONT DRIFTS N. AS LOW PASSES ACROSS THE AREA MON
NIGHT...A COLD FRONT WILL PUSH S...BRINGING A SHIFT TO NORTHERLY
WINDS UPWARDS OF 20KT INTO TUE MORNING. HIGH PRES WILL THEN BUILD
INTO THE UPPER GREAT LAKES DURING THE MIDWEEK PERIOD...RESULTING IN
WINDS UNDER 20KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 6 PM EDT THIS EVENING FOR LSZ243>245-
263-264-266.
DENSE FOG ADVISORY UNTIL NOON EDT TODAY FOR LSZ242-246>249-265.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...SRF
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
750 AM EDT SUN JUL 15 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 520 AM EDT SUN JUL 15 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW TROF JUST E OF THE FCST
AREA. SHRA/TSRA THAT ACCOMPANIED THE TROF ACROSS THE AREA YESTERDAY
HAVE RECENTLY EXITED THE SE PORTION OF THE FCST AREA. IN ITS WAKE...
CALM WIND/CLEARING SKIES AND MOISTURE FROM YESTERDAY`S RAINFALL HAS
LED TO SOME FOG DEVELOPMENT. FOG WILL QUICKLY BURN OFF WITHIN A
COUPLE HRS AFTER SUNRISE. UPSTREAM...A MID LEVEL RIDGE IS NOSING
INTO THE DAKOTAS/WRN MN. AS THE RIDGE SHIFTS E TODAY...UPPER MI WILL
FALL UNDER HEIGHT RISES/DEEP LAYER QVECTOR DIVERGENCE. MUCH DRIER
AIR...MAINLY IN THE MID LEVELS PER UPSTREAM 00Z KINL/CWPL
SOUNDINGS...WILL WORK AGAINST ANY AFTN CONVECTIVE DEVELOPMENT
DESPITE LAKE BREEZES PROVIDING LOW-LEVEL FORCING. THE K-INDEX ON THE
00Z CWPL/KINL SOUNDINGS WAS -11/-14C RESPECTIVELY DUE TO VERY DRY
AIR AROUND 700MB (DWPT DEPRESSIONS WERE IN EXCESS OF 40C). SO...
GOING DRY FCST APPEARS ON TRACK DESPITE SOME HIGH RES GUIDANCE
CONTINUING TO SHOW ISOLD CONVECTION OVER THE SCNTRL THIS AFTN.
MIXING TO AROUND 800MB ON FCST SOUNDINGS SUPPORTS MAX TEMPS UPWARDS
OF AROUND 90F. LIGHT GRADIENT WIND WILL ALLOW LAKE BREEZES OFF
LAKE SUPERIOR AND LAKE MICHIGAN TO PROVIDE SOME COOLING LAKESIDE.
SHORTWAVE ENERGY EJECTING FROM THE TROF CURRENTLY OVER THE WRN
STATES WILL HEAD INTO SCNTRL CANADA TONIGHT. IN RESPONSE...LOW-LEVEL
JET WILL INCREASE TO 45-50KT INTO THE NRN PLAINS. THIS WILL LIKELY
SUPPORT A CLUSTER OF SHRA/TSRA ON THE NOSE OF THE LOW-LEVEL JET AND
ALONG EDGE OF CAP ACROSS ND INTO SRN MANITOBA/NRN MN AND NRN
ONTARIO. AT THIS TIME...IT STILL APPEARS LOW-LEVEL JET WILL BE W OF
THE AREA AT 12Z MON...SO DO NOT ANTICIPATE ANY CONVECTION LATE
TONIGHT...EXCEPT POSSIBLY OVER NW LAKE SUPERIOR/ISLE ROYALE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 520 AM EDT SUN JUL 15 2012
BY 12Z MONDAY THE FRONTAL BOUNDARY WOULD BE ACROSS LAKE SUPERIOR
/AS A WARM FRONT/...STRETCHING FROM THE SFC LOW SET UP FROM NW MN TO
CENTRAL SD. DEPENDING ON THE AMOUNT OF MIXING /UP TO AROUND 800MB AT
SAW/ A FEW GUSTS OF 30 TO 35KTS COULD BE POSSIBLE FROM LATE MORNING
THROUGH THE REMAINDER OF THE DAYTIME HOURS. IF CLOUD COVER DOES NOT
INHIBIT MIXING...THESE STRONGER GUSTS COULD BE POSSIBLE ACROSS THE
DOWNSLOPE LOCATIONS NEAR LAKE SUPERIOR GIVEN THE STRENGTHENING SW
FLOW. AS FOR THE OFFICIAL FCST...HAVE INCREASED WINDS QUITE A BIT
FROM THE PREVIOUS FORECAST...WITH GUSTS OF 20-25KTS ACROSS MUCH OF
THE CWA BY MID AFTERNOON.
THE RECORD HIGH TEMP FOR MONDAY AT WFO MQT IS 95 DEGREES...WHICH MAY
BE BROKEN BY THE END OF THE DAY. CURRENTLY GOING ONLY A COUPLE OF
DEGREES COOLER THAN THIS RECORD...WITH 850MB TEMPS OF 22-24C
ALLOWING SEVERAL SITES ACROSS THE INTERIOR W HALF OF UPPER MI
REACHING 95 OR ABOVE.
THE SFC LOW SHOULD PUSH ACROSS THE AREA MONDAY AFTERNOON
THROUGH TUESDAY NIGHT. THE TRACK IS STILL UNCERTAIN...WITH THE
14/18Z GFS AND 15/00Z NAM PUSHING THE SFC LOW ACROSS THE KEWEENAW
PENINSULA AND ACROSS LAKE SUPERIOR BY EARLY MONDAY EVENING. THE
FARTHER SOUTH 14/12Z ECMWF INDICATES A BROADER LOW...STRETCHING
ACROSS CENTRAL AND SOUTHERN UPPER MI MONDAY NIGHT. THE 14/12Z
CANADIAN IS BEYOND CONSENSUS FROM MONDAY AFTERNOON ON...TRACKING THE
SFC LOW ACROSS ONTARIO AND N LAKE SUPERIOR...AND WILL NOT BE USED IN
THIS FORECAST UNTIL IT MOVES BACK IN LINE WITH THE REMAINDER OF
AVAILABLE GUIDANCE WEDNESDAY MORNING.
HIGH PRESSURE OVER CENTRAL CANADA TUESDAY MORNING WILL SLOWLY SHIFT
SE ACROSS LAKE SUPERIOR AND UPPER MI TUESDAY THROUGH THURSDAY. THE
COOLEST AFTERNOON TEMPS LOOK TO BE WEDNESDAY...TOPPING OUT IN THE
70S...COOLEST NEAR LAKE SUPERIOR AS DRY COOL AIR REMAINS. 850MB
TEMPS WEDNESDAY WILL BE A COOL 10-12C. THE FCST FOR THE CWA WILL
REMAIN DRY TUESDAY NIGHT THROUGH FRIDAY NIGHT. EXPECT THE SFC HIGH
TO DRIFT E TO THE LOWER GREAT LAKES AND W QUEBEC BY DAYBREAK FRIDAY
AND THE NEW ENGLAND COAST FRIDAY NIGHT...WITH A RIDGE REMAINING
ACROSS THE UPPER GREAT LAKES REGION.
A RELATIVELY WEAK SFC LOW STRETCHING FROM CENTRAL CANADA THROUGH THE
CENTRAL PLAINS LOOKS TO BECOME BETTER ORGANIZED TO OUR W SATURDAY
NIGHT...AS A SERIES OF DISTURBANCES NEAR FROM W AND CENTRAL CANADA
AS 500MB RIDGE BECOMES SUPPRESSED ACROSS THE CENTRAL AND SOUTHERN
PLAINS. KEPT CHANCE POPS FOR SATURDAY...ALTHOUGH CONFIDENCE IS
MODERATE TO LOW FOR SPECIFICS THAT FAR OUT IN THIS FCST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 749 AM EDT SUN JUL 15 2012
FOG WHICH HAS LED TO HIGHLY VARIABLE VIS/CIGS OVERNIGHT WILL BURN
OFF OVER THE NEXT HR OR TWO...LEAVING VFR CONDITIONS TO PREVAIL
TODAY AND TONIGHT AT KIWD/KCMX/KSAW. THERE IS A SMALL POTENTIAL FOR
FOG TO REDEVELOP TONIGHT...BUT A SLOW INCREASE IN NEAR SFC WINDS WILL
WORK TO LIMIT POTENTIAL. ALSO...SOIL MOISTURE WHICH PLAYED A ROLE IN
FOG DEVELOPMENT OVERNIGHT WILL HAVE A CHANCE TO DRY OUT TODAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 520 AM EDT SUN JUL 15 2012
BIGGEST CONCERN IN THE SHORT TERM WILL BE FOG. 11-3.9MICRON
SATELLITE IMAGERY INDICATES FOG (PROBABLY NOT STRATUS) EXPANDING S
AND E FROM NCNTRL LAKE SUPERIOR. MORE FOG MAY BE DEVELOPING FROM
KEWEENAW BAY TOWARD MARQUETTE/MUNISING. WITH DEVELOPING MESO HIGH
PRES OVER THE LAKE TODAY...IT`S QUITE POSSIBLE FOG MAY END UP
SPREADING TO THE SHORELINES AROUND THE ENTIRE LAKE TODAY. ALWAYS
DIFFICULT TO FCST MARINE FOG...SO TRENDS WILL NEED TO MONITORED
CLOSELY TODAY FOR MOVEMENT/DEVELOPMENT/DISSIPATION OF FOG. ONCE
DAYLIGHT ARRIVES...VIS SATELLITE IMAGERY WILL PROVIDE A BETTER LOOK
AT HOW THE FOG IS EVOLVING. QUITE POSSIBLE DENSE FOG ADVY MAY NEED
TO BE ISSUED. FOR NOW...CARRIED FOG MENTION THRU EARLY AFTN OVER
MAINLY CNTRL AND ERN LAKE SUPERIOR.
OTHERWISE...WITH HIGH PRES DEVELOPING OVER LAKE SUPERIOR TODAY...
WINDS WILL BE UNDER 15KT. ALTHOUGH WINDS WILL BECOME S-SE TONIGHT IN
ADVANCE OF APPROACHING LOW PRES...SPEEDS SHOULD REMAIN 15KT OR LESS.
THERE IS SOME UNCERTAINTY IN WHERE WARM FRONT ASSOCIATED WITH THE
LOW WILL BE POSITIONED MON. AT THIS TIME...IT APPEARS THAT AT LEAST
SRN PORTIONS OF THE LAKE WILL SEE INCREASING S-SW WINDS MON UPWARDS
OF 20KT AS WARM FRONT DRIFTS N. AS LOW PASSES ACROSS THE AREA MON
NIGHT...A COLD FRONT WILL PUSH S...BRINGING A SHIFT TO NORTHERLY
WINDS UPWARDS OF 20KT INTO TUE MORNING. HIGH PRES WILL THEN BUILD
INTO THE UPPER GREAT LAKES DURING THE MIDWEEK PERIOD...RESULTING IN
WINDS UNDER 20KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL NOON EDT TODAY FOR LSZ242>249-263>266.
LAKE MICHIGAN...NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
522 AM EDT SUN JUL 15 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 520 AM EDT SUN JUL 15 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW TROF JUST E OF THE FCST
AREA. SHRA/TSRA THAT ACCOMPANIED THE TROF ACROSS THE AREA YESTERDAY
HAVE RECENTLY EXITED THE SE PORTION OF THE FCST AREA. IN ITS WAKE...
CALM WIND/CLEARING SKIES AND MOISTURE FROM YESTERDAY`S RAINFALL HAS
LED TO SOME FOG DEVELOPMENT. FOG WILL QUICKLY BURN OFF WITHIN A
COUPLE HRS AFTER SUNRISE. UPSTREAM...A MID LEVEL RIDGE IS NOSING
INTO THE DAKOTAS/WRN MN. AS THE RIDGE SHIFTS E TODAY...UPPER MI WILL
FALL UNDER HEIGHT RISES/DEEP LAYER QVECTOR DIVERGENCE. MUCH DRIER
AIR...MAINLY IN THE MID LEVELS PER UPSTREAM 00Z KINL/CWPL
SOUNDINGS...WILL WORK AGAINST ANY AFTN CONVECTIVE DEVELOPMENT
DESPITE LAKE BREEZES PROVIDING LOW-LEVEL FORCING. THE K-INDEX ON THE
00Z CWPL/KINL SOUNDINGS WAS -11/-14C RESPECTIVELY DUE TO VERY DRY
AIR AROUND 700MB (DWPT DEPRESSIONS WERE IN EXCESS OF 40C). SO...
GOING DRY FCST APPEARS ON TRACK DESPITE SOME HIGH RES GUIDANCE
CONTINUING TO SHOW ISOLD CONVECTION OVER THE SCNTRL THIS AFTN.
MIXING TO AROUND 800MB ON FCST SOUNDINGS SUPPORTS MAX TEMPS UPWARDS
OF AROUND 90F. LIGHT GRADIENT WIND WILL ALLOW LAKE BREEZES OFF
LAKE SUPERIOR AND LAKE MICHIGAN TO PROVIDE SOME COOLING LAKESIDE.
SHORTWAVE ENERGY EJECTING FROM THE TROF CURRENTLY OVER THE WRN
STATES WILL HEAD INTO SCNTRL CANADA TONIGHT. IN RESPONSE...LOW-LEVEL
JET WILL INCREASE TO 45-50KT INTO THE NRN PLAINS. THIS WILL LIKELY
SUPPORT A CLUSTER OF SHRA/TSRA ON THE NOSE OF THE LOW-LEVEL JET AND
ALONG EDGE OF CAP ACROSS ND INTO SRN MANITOBA/NRN MN AND NRN
ONTARIO. AT THIS TIME...IT STILL APPEARS LOW-LEVEL JET WILL BE W OF
THE AREA AT 12Z MON...SO DO NOT ANTICIPATE ANY CONVECTION LATE
TONIGHT...EXCEPT POSSIBLY OVER NW LAKE SUPERIOR/ISLE ROYALE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 520 AM EDT SUN JUL 15 2012
BY 12Z MONDAY THE FRONTAL BOUNDARY WOULD BE ACROSS LAKE SUPERIOR
/AS A WARM FRONT/...STRETCHING FROM THE SFC LOW SET UP FROM NW MN TO
CENTRAL SD. DEPENDING ON THE AMOUNT OF MIXING /UP TO AROUND 800MB AT
SAW/ A FEW GUSTS OF 30 TO 35KTS COULD BE POSSIBLE FROM LATE MORNING
THROUGH THE REMAINDER OF THE DAYTIME HOURS. IF CLOUD COVER DOES NOT
INHIBIT MIXING...THESE STRONGER GUSTS COULD BE POSSIBLE ACROSS THE
DOWNSLOPE LOCATIONS NEAR LAKE SUPERIOR GIVEN THE STRENGTHENING SW
FLOW. AS FOR THE OFFICIAL FCST...HAVE INCREASED WINDS QUITE A BIT
FROM THE PREVIOUS FORECAST...WITH GUSTS OF 20-25KTS ACROSS MUCH OF
THE CWA BY MID AFTERNOON.
THE RECORD HIGH TEMP FOR MONDAY AT WFO MQT IS 95 DEGREES...WHICH MAY
BE BROKEN BY THE END OF THE DAY. CURRENTLY GOING ONLY A COUPLE OF
DEGREES COOLER THAN THIS RECORD...WITH 850MB TEMPS OF 22-24C
ALLOWING SEVERAL SITES ACROSS THE INTERIOR W HALF OF UPPER MI
REACHING 95 OR ABOVE.
THE SFC LOW SHOULD PUSH ACROSS THE AREA MONDAY AFTERNOON
THROUGH TUESDAY NIGHT. THE TRACK IS STILL UNCERTAIN...WITH THE
14/18Z GFS AND 15/00Z NAM PUSHING THE SFC LOW ACROSS THE KEWEENAW
PENINSULA AND ACROSS LAKE SUPERIOR BY EARLY MONDAY EVENING. THE
FARTHER SOUTH 14/12Z ECMWF INDICATES A BROADER LOW...STRETCHING
ACROSS CENTRAL AND SOUTHERN UPPER MI MONDAY NIGHT. THE 14/12Z
CANADIAN IS BEYOND CONSENSUS FROM MONDAY AFTERNOON ON...TRACKING THE
SFC LOW ACROSS ONTARIO AND N LAKE SUPERIOR...AND WILL NOT BE USED IN
THIS FORECAST UNTIL IT MOVES BACK IN LINE WITH THE REMAINDER OF
AVAILABLE GUIDANCE WEDNESDAY MORNING.
HIGH PRESSURE OVER CENTRAL CANADA TUESDAY MORNING WILL SLOWLY SHIFT
SE ACROSS LAKE SUPERIOR AND UPPER MI TUESDAY THROUGH THURSDAY. THE
COOLEST AFTERNOON TEMPS LOOK TO BE WEDNESDAY...TOPPING OUT IN THE
70S...COOLEST NEAR LAKE SUPERIOR AS DRY COOL AIR REMAINS. 850MB
TEMPS WEDNESDAY WILL BE A COOL 10-12C. THE FCST FOR THE CWA WILL
REMAIN DRY TUESDAY NIGHT THROUGH FRIDAY NIGHT. EXPECT THE SFC HIGH
TO DRIFT E TO THE LOWER GREAT LAKES AND W QUEBEC BY DAYBREAK FRIDAY
AND THE NEW ENGLAND COAST FRIDAY NIGHT...WITH A RIDGE REMAINING
ACROSS THE UPPER GREAT LAKES REGION.
A RELATIVELY WEAK SFC LOW STRETCHING FROM CENTRAL CANADA THROUGH THE
CENTRAL PLAINS LOOKS TO BECOME BETTER ORGANIZED TO OUR W SATURDAY
NIGHT...AS A SERIES OF DISTURBANCES NEAR FROM W AND CENTRAL CANADA
AS 500MB RIDGE BECOMES SUPPRESSED ACROSS THE CENTRAL AND SOUTHERN
PLAINS. KEPT CHANCE POPS FOR SATURDAY...ALTHOUGH CONFIDENCE IS
MODERATE TO LOW FOR SPECIFICS THAT FAR OUT IN THIS FCST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 132 AM EDT SUN JUL 15 2012
GIVEN CLEARING SKIES AND ADDITIONAL LOW-LEVEL MOISTURE FM RECENT
RAINFALL...EXPECT STRATUS/FOG TO DEVELOP OVER MUCH OF UPPER MI.
CONFIDENCE IS FAIRLY HIGH THAT FOG WILL BRING KSAW VSBY AND CIGS
DOWN TO LIFR AND POSSIBLE VLIFR CONDITIONS OVERNIGHT AS RAINFALL WAS
MORE ABUNDANT IN THAT AREA ON SATURDAY. AT IWD AND CMX...LESSER
RAINFALL ON SATURDAY CASTS SOME UNCERTAINTY AS TO FOG POTENTIAL
OVERNIGHT. HAVE ALREADY SEEN LOWER STRATUS DECK FORM AT CMX...AND
THOUGH THAT MAY BE INTERMITTENT INITIALLY FOR THE OVERNIGHT HOURS
DUE TO BLOWOFF CLOUDS OVR WESTERN LK SUPERIOR...WILL GO WITH IDEA
THAT STRATUS AND IFR FOG STAY IN THERE OVERNIGHT. MAY EVEN SEE LOWER
VSBY LATER TONIGHT BRIEFLY IF THE BLOWOFF DISIPPATES COMPLETELY. AT
IWD WILL KEEP WITH AN MVFR VSBY FOR JUST PATCHY FOG. ALL CIG/VSBY
REDUCTION WILL BE DONE SHORTLY AFT SUNRISE. EXPECT VFR CONDITIONS
FROM MID MORNING THRU THE END OF THE FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 520 AM EDT SUN JUL 15 2012
BIGGEST CONCERN IN THE SHORT TERM WILL BE FOG. 11-3.9MICRON
SATELLITE IMAGERY INDICATES FOG (PROBABLY NOT STRATUS) EXPANDING S
AND E FROM NCNTRL LAKE SUPERIOR. MORE FOG MAY BE DEVELOPING FROM
KEWEENAW BAY TOWARD MARQUETTE/MUNISING. WITH DEVELOPING MESO HIGH
PRES OVER THE LAKE TODAY...IT`S QUITE POSSIBLE FOG MAY END UP
SPREADING TO THE SHORELINES AROUND THE ENTIRE LAKE TODAY. ALWAYS
DIFFICULT TO FCST MARINE FOG...SO TRENDS WILL NEED TO MONITORED
CLOSELY TODAY FOR MOVEMENT/DEVELOPMENT/DISSIPATION OF FOG. ONCE
DAYLIGHT ARRIVES...VIS SATELLITE IMAGERY WILL PROVIDE A BETTER LOOK
AT HOW THE FOG IS EVOLVING. QUITE POSSIBLE DENSE FOG ADVY MAY NEED
TO BE ISSUED. FOR NOW...CARRIED FOG MENTION THRU EARLY AFTN OVER
MAINLY CNTRL AND ERN LAKE SUPERIOR.
OTHERWISE...WITH HIGH PRES DEVELOPING OVER LAKE SUPERIOR TODAY...
WINDS WILL BE UNDER 15KT. ALTHOUGH WINDS WILL BECOME S-SE TONIGHT IN
ADVANCE OF APPROACHING LOW PRES...SPEEDS SHOULD REMAIN 15KT OR LESS.
THERE IS SOME UNCERTAINTY IN WHERE WARM FRONT ASSOCIATED WITH THE
LOW WILL BE POSITIONED MON. AT THIS TIME...IT APPEARS THAT AT LEAST
SRN PORTIONS OF THE LAKE WILL SEE INCREASING S-SW WINDS MON UPWARDS
OF 20KT AS WARM FRONT DRIFTS N. AS LOW PASSES ACROSS THE AREA MON
NIGHT...A COLD FRONT WILL PUSH S...BRINGING A SHIFT TO NORTHERLY
WINDS UPWARDS OF 20KT INTO TUE MORNING. HIGH PRES WILL THEN BUILD
INTO THE UPPER GREAT LAKES DURING THE MIDWEEK PERIOD...RESULTING IN
WINDS UNDER 20KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...JLA
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
656 AM CDT SUN JUL 15 2012
.UPDATED FOR 12Z AVIATION DISCUSSION...
&&
.DISCUSSION...
ANOTHER WARM DAY IS EXPECTED TODAY...WITH POTENTIALLY RECORD
BREAKING HEAT ON MONDAY. ON TUESDAY A FRONTAL BOUNDARY WILL SLOWLY
SLIDE SOUTHEAST THROUGH THE REGION. THIS WILL BE ACCOMPANIED BY A
FEW SHOWERS AND THUNDERSTORMS...AS WELL AS SOME SLIGHTLY COOLER
WEATHER. HOWEVER...THIS BOUNDARY WILL STRUGGLE TO MAKE IT SOUTH OF
THE IA/MN BORDER...AND EVENTUALLY SWING BACK NORTHWARD AS A WARM
FRONT...SETTING THE STAGE FOR ANOTHER HEAT WAVE FOR THE UPCOMING
WEEKEND.
TODAY THROUGH TUESDAY...SYNOPTIC ANALYSIS VIA NORTH AMERICAN WATER
VAPOR IMAGERY AND 500MB HEIGHTS AND WINDS IDENTIFIED AN UPPER LEVEL
TROUGH ACROSS THE GREAT LAKES...WITH A DOWNSTREAM RIDGE CENTERED
OVER THE HIGH PLAINS. AN H850 THERMAL RIDGE WAS LONGITUDINALLY
ORIENTED ON THE LEE SIDE OF THE ROCKIES...WHILE AT THE SURFACE A LOW
PRESSURE SYSTEM WAS LOCATED IN EASTERN MONTANA. OVER THE NEXT COUPLE
OF DAYS...A SHORTWAVE WILL ROUND THE UPPER LEVEL RIDGE AND CAUSE THE
SURFACE LOW TO TRACK EASTWARD ACROSS THE US/CANADA BORDER. AS A
RESULT...SOUTHWEST FLOW AND THE H850 THERMAL RIDGE WILL ALSO
PROPAGATE EASTWARD AND BE LOCATED OVER THE UPPER MIDWEST BY MONDAY
AFTERNOON. FROM A CONCEPTUAL MODEL PERSPECTIVE...THIS IS THE PERFECT
SETUP FOR RECORD WARMTH. FROM A NUMERICAL MODEL PERSPECTIVE...THE NAM
HAS BEEN THE WARMEST WITH WIDESPREAD HUNDREDS ACROSS THE CWA. IN
FACT...FORECAST BURR SOUNDINGS FROM THE 15.00 NAM FOR MONDAY
AFTERNOON ARE ALMOST IDENTICAL TO THE OBSERVED 00Z MSP SOUNDING FROM
JULY 4 2012...WHICH YIELDED A HIGH TEMP OF 102 AT KMSP.
THEREFORE...TEMPERATURES WERE INCREASED A COUPLE OF DEGREES FROM THE
PREVIOUS FORECAST. AFTERNOON MIXING SHOULD KEEP DEWPOINTS IN THE
UPPER 50S TO LOWER 60S...SO HEAT INDICES WILL NOT EXCEED THE ACTUAL
AIR TEMPERATURE BY MORE THAN A FEW DEGREES. THEREFORE HAVE ISSUED A
HEAT ADVISORY BEGINNING LATE MONDAY MORNING AND LASTING THROUGH LATE
MONDAY EVENING. AS THE AFOREMENTIONED SURFACE LOW CONTINUES TOWARDS
THE GREAT LAKES MONDAY NIGHT...A DIFFUSE COLD FRONT WILL GRADUALLY
SLIDE SOUTHWARD THROUGH THE REGION. THE H850 THERMAL RIDGE WILL TAKE
ON A MORE EAST/WEST ORIENTATION WITH THE WARMEST TEMPERATURES SOUTH
OF THE CWA. ALSO...WINDS WILL WEAKEN SLIGHTLY SO NOT EXPECTING AS
MUCH DYNAMICALLY INDUCED BOUNDARY LAYER HEATING DURING AFTERNOON
HOURS. WITH THAT SAID...TEMPERATURES WILL STILL REACH THE MID 90S
SOUTH OF THE FRONT ACROSS FAR SOUTHERN MINNESOTA...SO THE HEAT
ADVISORY MAY NEED TO BE EXTENDED TO COVER THIS AREA. AS FAR AS
PRECIP GOES...WARM AIR ALOFT SHOULD KEEP THE PRECIP CHANCES ACROSS
THE NORTH FOR SUNDAY AND MONDAY. AS THE FRONTAL BOUNDARY SAGS
SOUTHWARD...PRECIP CHANCES WILL INCREASE ALONG IT. LOW LEVEL
CONVERGENCE IS RELATIVELY WEAK...AND THERE IS LITTLE IN THE WAY OF
UPPER LEVEL FORCING. NONE THE LESS...A FEW ISOLATED SHOWERS AND
THUNDERSTORMS WILL LIKELY PERCOLATE ALONG THIS BOUNDARY...WITH
ISOLATED SEVERE WIND AND HAIL POSSIBLE.
WEDNESDAY THROUGH SATURDAY...AS MENTIONED EARLIER...THIS BOUNDARY
WILL STRUGGLE TO PUSH SOUTH OF THE IA/MN BORDER. BY MIDWEEK ANOTHER
UPPER LEVEL WAVE WILL CROSS THE IDAHO PANHANDLE...RESULTING IN
ANOTHER LEESIDE LOW IN SOUTHERN ALBERTA. THIS WILL DRAW THE
LINGERING FRONTAL BOUNDARY BACK NORTHWARD AS A WARM FRONT. THE
PRECIP WILL STILL REMAIN FOCUSED ALONG THIS BOUNDARY...WITH BETTER
CHANCES NEAR THE MN/DAKOTA BORDER. THE UPPER LEVEL RIDGE WILL BUILD
ACROSS THE CENTRAL CONUS...WITH HOT AND HUMID CONDITIONS RETURNING
TO THE REGION BY THE END OF THE WEEK. GIVEN THE SYNOPTIC
SETUP...INCREASED TEMPS A FEW DEGREES ABOVE GUIDANCE IN THE
EXTENDED. SO IN SUMMATION...LOOKS LIKE THE DRY AND WARM CONDITIONS
WILL STICK AROUND FOR AT LEAST THE NEXT 7 TO 10 DAYS.
&&
.AVIATION.../12Z TAF ISSUANCE/
HIGH PRESSURE IS CENTERED OVER CENTRAL MINNESOTA EARLY THIS
MORNING WITH CALM WINDS AND PATCHY FOG/HAZE AT SOME OF THE TAF
SITES. A VERY BENIGN DAY AND EVENING IN STORE FOR AVIATION
INTERESTS. NAM CU RULE INDICATES SCT050 THIS AFTERNOON IN WESTERN
WISCONSIN BUT RAP CU RULE INDICATES NO CU. WENT WITH FEW050 KSTC
EASTWARD. HIGH PRESSURE WILL EXIT THE AREA AND BY LATE MORNING
WILL SEE SE WINDS AROUND THE 10 KT RANGE INCREASING IN THE
AFTERNOON WITH...KAXN AND KRWF GUSTING UP TO 20 KNOTS IN THE
AFTERNOON. OTHER SITES WILL SEE A LIGHT WEST WIND BACK TO THE
SOUTH AND SOUTHEAST IN THE AFTERNOON WITH SPEEDS LESS THAN 10
KNOTS. FOR TONIGHT SOUTHEAST WINDS WILL REMAIN AROUND 10KTS. FOR
MONDAY SKC WITH SOUTHWEST WINDS NEAR 20 KTS.
KMSP...VFR THROUGH THE PERIOD. LIGHT WINDS BECOMING SOUTH SOUTHEAST
8-10 KNOTS SUNDAY AFTERNOON WITH A FEW GUSTS TO 13KTS.
OUTLOOK...
MONDAY...VFR. HOT. WINDS S-SW 15-20 KTS.
TUESDAY...VFR. CHANCE OF TSRA WITH FRONTAL PASSAGE. WINDS
BECOMING NE 5-10 KTS.
WEDNESDAY...VFR. EAST WINDS 5 TO 10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...HEAT ADVISORY FROM 11 AM TO 9 PM CDT MONDAY 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...HEAT ADVISORY FROM 11 AM TO 9 PM CDT MONDAY FOR BARRON-CHIPPEWA-
DUNN-EAU CLAIRE-PEPIN-PIERCE-POLK-RUSK-ST. CROIX.
&&
$$
JRB/DRL
AREA FORECAST DISCUSSION
NWS BILLINGS MT
917 PM MDT MON JUL 16 2012
.SHORT TERM...VALID FOR TUE AND WED...
CONVECTION CONTINUES A SLOW NORTH-NORTHEAST PROPAGATION ACROSS THE
SOUTH CENTRAL PART OF MT AS OF 03 UTC. BASED ON OBJECTIVE ANALYSIS
DATA FROM THE RAP...THERE IS 500-1000 J/KG OF MUCAPE AVAILABLE FOR
THIS ACTIVITY...BUT THE MID-LEVEL LAPSE RATES ARE NOT MUCH STEEPER
THAN MOIST ADIABATIC. ADD IN RELATIVELY WEAK STEERING FLOW OUTSIDE
OF FAR SOUTHEASTERN MT...AND IT IS EASY TO SEE WHY THE STORMS HAVE
MAINLY BEEN RAIN PRODUCERS. THE MAIN QUESTION HEADING FORWARD WILL
BE HOW LONG THE CONVECTION WILL PERSIST OVERNIGHT AS IT PROPAGATES
INTO MORE OF SOUTHEASTERN MT. THERE ARE CONFLICTING SIGNALS IN THE
MODEL DATA WITH THE 00 UTC NAM ESSENTIALLY DRY AFTER 06 UTC...EVEN
WHILE THE LAST COUPLE HRRR RUNS SIMULATE PRECIPITATION MOVING INTO
SOUTHEASTERN MT. SINCE THE RESERVOIR OF MODEST MUCAPE EXTENDS INTO
AREAS DOWNSTREAM OF CURRENT CONVECTION...WE DECIDED TO MAINTAIN 40
PERCENT POPS FOR PLACES LIKE MILES CITY AND BAKER AFTER 06 UTC. WE
DO NOT HAVE A LOT OF CONFIDENCE IN THIS IDEA THOUGH. WE DID DECIDE
TO LOWER POPS BACK CLOSER TO 30 PERCENT ACROSS SOUTH CENTRAL MT IN
THE 06 TO 12 UTC TIME FRAME BASED ON OBSERVATIONAL TRENDS...BUT WE
MADE ONLY MINOR CHANGES TO THE REST OF TONIGHT/S FORECAST. SCHULTZ
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
12Z GFS HAS MADE A CHANGE WITH THE MEDIUM RANGE FORECAST. OVERALL
PATTERN LOOKS A BIT MORE UNSETTLED AS THE NEW MODEL RUN NOW KEEPS
THE UPPER OVER OREGON IN PLACE AND DOES NOT SCOOP IT UP WITH THE
ADVANCING TROUGH. THIS IS DUE TO THE FACT THAT THE MODEL KEEPS
THE UPPER TROUGH NORTH OF THE CONTINENTAL US AND SWINGS WEAKER
ENERGY ACROSS SOUTHERN ENERGY. THIS ALLOW THE FORECAST AREA TO
REMAIN IN SOUTHWEST FLOW...AND WITH THAT...ACCESS TO MONSOON
MOISTURE. THE TREND MAKES SENSE...ESPECIALLY SINCE THIS COMES IN
LINE WITH WHAT THE ECMWF WAS DOING. THAT BEING SAID...THERE IS A
LARGE TIMING DIFFERENCES IN SWINGING THE WEAKENING UPPER LEVEL
LOW ACROSS FROM THE GFS AND ECMWF. THE ECMWF WAS ABOUT A DAY
FASTER. WILL OPT TO SEE ANOTHER COUPLE OF RUNS BEFORE JUMPING ON
ANY CHANGES. GIVEN THE 12Z RUNS...WOULD SEE THE BEST CHANCE OF
CONVECTION NOW ON FRIDAY AND SATURDAY...IF THESE CHANGES HOLD
TRUE. WILL SEE HOW THIS POTENTIAL CHANGE EVOLVES. TWH
&&
.AVIATION...
SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE TO IMPACT THE
AREA THIS EVENING...WITH A DECREASE IN COVERAGE AFTER 06Z. LOCAL
MVFR CONDITIONS AND HEAVY RAIN/SMALL HAIL CAN BE EXPECTED IN THE
STRONGER CELLS. OTHERWISE VFR WILL PREVAIL. MORE THUNDERSTORM
ACTIVITY IS ANTICIPATED ON TUESDAY WITH THE GREATEST COVERAGE
BEING EAST OF KBIL...WITH LOCAL MVFR AGAIN IN THIS AREA. ERRATIC
SFC WINDS CAN BE EXPECTED NEAR STORMS. JKL
&&
.PRELIMINARY POINT TEMP/POPS...
TUE WED THU FRI SAT SUN MON
-----------------------------------------------------------
BIL 064/091 066/096 066/098 065/098 065/095 063/095 064/095
54/T 20/U 11/U 21/U 11/U 11/U 11/U
LVM 053/088 054/094 054/096 056/096 056/093 054/094 054/094
54/T 20/U 11/U 11/B 10/U 01/B 11/B
HDN 065/093 064/099 064/101 062/101 062/098 060/098 060/098
54/T 21/U 11/G 21/G 21/U 11/U 11/U
MLS 069/094 069/099 069/101 069/101 069/097 066/098 066/098
45/T 31/B 11/G 21/G 21/U 11/U 11/U
4BQ 065/092 066/098 066/100 066/100 065/097 062/097 062/097
44/T 32/T 11/U 21/U 21/B 11/U 11/U
BHK 064/091 065/096 065/098 064/098 064/094 063/094 063/094
45/T 42/T 21/U 21/U 21/B 11/U 11/U
SHR 060/089 061/096 061/098 059/098 059/096 057/096 056/096
54/T 31/B 11/U 11/U 11/B 11/B 11/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
855 PM MDT MON JUL 16 2012
.DISCUSSION...
UPDATE FORTHCOMING. HAVE LOWERED POPS ACROSS MOST OF THE COUNTY
WARNING AREA. THE UPPER LOW ALONG THE CALIFORNIA/OREGON COAST IS WELL
DEPICTED BY SATELLITE IMAGERY AND CONTINUES TO SEND MOISTURE AND
SHORT WAVE ENERGY ACROSS SOUTHWEST MONTANA...INTO NORTH CENTRAL
MONTANA. SHOWERS AND THUNDERSTORMS THAT HAVE DEVELOPED ARE GENERALLY
ISOLATED IN NATURE AND ARE MAINLY PRODUCING BRIEF HEAVY RAIN DUE TO
CONTINUED HIGH PRECIPITABLE WATER VALUES. HAVE DROPPED POPS BACK INTO THE
SCATTERED CATEGORY. HRRR ANALYSIS CONTINUES TO SHOW CONVECTIVE
ACTIVITY CONTINUING THROUGH THE EVENING BEFORE DIMINISHING AFTER 09Z.
TEMPERATURE FORECASTS LOOK ON TRACK. EMANUEL
&&
.AVIATION...
UPDATED 0030Z.
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO PUSH NORTHWARD THROUGH
CENTRAL AND NORTH CENTRAL MONTANA THIS EVENING. EXPECT A BRIEF
PERIOD OF HEAVY RAIN...AND HAIL UP TO ONE HALF INCH FROM THE
STRONGER STORMS. MOUNTAINS WILL BE OBSCURED FOR A SHORT TIME IN
HEAVIER RAINFALL. EXPECT SHOWERS TO DIMINISH AFTER 09Z
TUESDAY...WITH MORE STORMS REDEVELOPING IN SOUTHWEST MONTANA AFTER
20Z TUESDAY. BRUSDA
&&
.PREV DISCUSSION...ISSUED 251 PM MDT MON JUL 16 2012
TONIGHT THROUGH WEDNESDAY...A WEATHER DISTURBANCE ALOFT OVER
SOUTHERN IDAHO MONDAY AFTERNOON WILL BE MOVING NORTH TONIGHT. IT
WILL MOVE INTO SOUTHWEST MONTANA THIS EVENING AND REACH CENTRAL
MONTANA LATE TONIGHT. MONSOONAL MOISTURE IS ASSOCIATED WITH THE
DISTURBANCE ALONG WITH INSTABILITY. WILL GO WITH SCATTERED SHOWERS
AND THUNDERSTORMS FOR MOST LOWER ELEVATIONS WITH MORE WIDESPREAD
SHOWERS AND THUNDERSTORMS IN THE MOUNTAINS OVER SOUTHWEST AND
CENTRAL MONTANA. THE PLAINS OF NORTHERN MOUNTAIN WILL CONTINUE
RELATIVELY DRIER UNTIL THURSDAY WHEN THE DISTURBANCE REACHES THAT
AREA. EVEN THOUGH SOUTHWEST AND MOST OF CENTRAL MONTANA WILL BE
SOUTH OF THE DISTURBANCE TUESDAY AFTERNOON AND SOMEWHAT
DRIER..THERE WILL AGAIN BE INSTABILITY OVER THAT AREA SO WILL
CONTINUE THE IDEA OF A CHANCE OF SHOWERS AND THUNDERSTORMS. AS THE
DISTURBANCE MOVES INTO CANADA BY TUESDAY EVENING A DRIER AIRMASS
WILL SPREAD OVER THE FORECAST AREA RESULTING IN MOSTLY CLEAR SKIES
WITH LITTLE IF ANY THREAT OF PRECIPITATION. STILL SEE A WARMING
TREND TUESDAY AND WEDNESDAY AND ESPECIALLY WEDNESDAY WITH HIGHS
THAT DAY EXPECTED TO BE SOME 5 TO 10 DEGREES WARMER THAN THOSE OF
TUESDAY. BLANK
WEDNESDAY NIGHT THROUGH MONDAY NIGHT...A LOW PRESSURE TROF WILL
BE OVER THE PACIFIC NORTHWEST WEDNESDAY NIGHT WITH
UNSETTLED...SOUTHWEST FLOW ALOFT OVER THE ZONES. A SHORTWAVE WILL
MOVE THROUGH THIS FLOW ALOFT THURSDAY. THE AIRMASS SHOULD BE VERY
DRY ACROSS THE SOUTHWEST ZONES AND MOST INSTABILITY AND CONVECTION
IS EXPECTED TO THE NORTH. THE TROF WILL REMAIN OVER THE PACIFIC
NORTHWEST FRIDAY ALTHOUGH THE AIRMASS WILL BE QUITE DRY AND THE
CHANCE OF AFTERNOON CONVECTION WILL BE SLIGHT. THE UPPER LEVEL
TROF WILL FINALLY MOVE EAST SATURDAY BUT THE LOW WILL BE QUITE FAR
NORTH...CROSSING THROUGH ALBERTA. CENTRAL MONTANA WILL REMAIN
QUITE DRY. HIGH PRESSURE AND CONTINUED VERY WARM TEMPERATURES WILL
CONTINUE THROUGH MONDAY. AT THIS TIME...A RETURN OF MONSOONAL
MOISTURE IS POSSIBLE ACROSS THE SOUTHWEST ZONES MONDAY AND THE
POSSIBILITY OF AFTERNOON CONVECTION WILL INCREASE. ZELZER
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 57 83 60 94 / 30 40 20 10
CTB 53 75 55 90 / 30 50 30 10
HLN 58 87 58 93 / 60 40 20 10
BZN 51 88 50 93 / 50 30 20 10
WEY 42 75 40 80 / 40 30 10 10
DLN 51 81 51 88 / 40 30 20 10
HVR 57 84 59 95 / 20 50 30 10
LWT 55 83 56 90 / 50 50 30 10
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...EMANUEL/BLANK
LONG TERM...ZELZER
AVIATION...BRUSDA
WEATHER.GOV/GREATFALLS
AREA FORECAST DISCUSSION
NWS GLASGOW MT
312 PM MDT SUN JUL 15 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH TUESDAY...
WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL LOW OVER THE PACIFIC
NORTHWEST WHICH CONTINUE TO MOVE SOUTHWARD OVER THE WEST COAST
BEFORE BECOMING STATIONARY SOMEWHERE NEAR THE NORTHERN CALIFORNIA
COAST LINE BY THE END OF THE SHORT TERM PERIOD. THIS WILL LEAVE
MONTANA IN AN OVER ALL SW FLOW ALOFT PATTERN. THIS WILL CONTINUE
THE FEEDING OF PACIFIC MOISTURE FOR THE NEXT FEW DAYS ALONG WITH
DISTURBANCES MOVING OVER MONTANA CAUGHT IN THIS FLOW.FOR
THUNDERSTORMS ACROSS THE CENTRAL AND NORTHERN ROCKIES OVERNIGHT
LAST NIGHT AND TODAY.
SO LOOKING AT THE FORECAST FOR LATE THIS AFTERNOON AND THIS
EVENING THE CHANCE OF SHOWERS AND THUNDERSTORMS IS POSSIBLE. THE
WATER VAPOR IMAGERY SHOWS TWO JET STREAKS...ONE MOVING INTO SW
MONTANA AND ONE MOVING INTO SW WYOMING WHICH SHOULD HELP AID IN
THUNDERSTORM DEVELOPMENT ACROSS CENTRAL AND EASTERN MONTANA LATE
THIS AFTERNOON AND EVENING. THUNDERSTORMS THAT ARE ALREADY THERE
COULD BE ENHANCED BY THE LEFT FRONT ENTRANCE REGION OF THE JET
STREAK ACROSS SW WYOMING ONCE IT GETS CLOSE TO CENTRAL MONTANA
LATE THIS EVENING. THE LATEST HRRR MODELS SHOWS CONVECTION
DEVELOPING ACROSS CENTRAL MONTANA AND MOVING EASTWARD INTO
NORTHEAST MONTANA THIS EVENING. SO DECIDED TO INCREASE POPS AND
MENTION BRIEF MODERATE RAINFALL ALONG WITH POSSIBLE GUSTY WINDS.
THE CHANCE OF THUNDERSTORMS WILL END AFTER MIDNIGHT BUT REDEVELOP
MONDAY AFTERNOON AS ANOTHER SHORTWAVE MOVE UP IN THE SW FLOW FROM
THE NORTHERN GREAT BASIN. THIS WAVE SEEMS TO GET STUCK OVER
CENTRAL MONTANA BEFORE GETTING PUSHED NE TUESDAY EVENING. SHOULD
PROVIDE ENOUGH LIFT AND INSTABILITY TO CONTINUE CHANCE TO SLIGHT
CHANCE POPS ACROSS THE REGION THROUGH THE SAME TIME FRAME. NO
SEVERE WEATHER IS EXPECT DURING THIS TIME FRAME BUT A FEW STRONG
THUNDERSTORMS CELL ARE POSSIBLE. SPC HAS A GENERAL THUNDERSTORM
RISK FOR MONDAY AND WE ARE PROBABLY LOOKING AT THE SAME THING
FOR TUESDAY. HIGHS ACROSS THE REGION BOTH MONDAY AND TUESDAY WILL
BE IN THE UPPER 80S AND LOWER 90S. CLOUD COVER WILL PLAY BIG
FACTOR IN THE TEMPERATURE FORECAST MORE ON TUESDAY RATHER THEN
MONDAY. RSMITH
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...
AFTERNOON UPDATE...THE ONLY REAL CHANGE TO THE EXTENDED FORECAST
IS TO ADD SOME POPS INTO THE FORECAST IN THE FRIDAY INTO SATURDAY
TIME FRAME. A SURFACE TROF SETS UP OVER THE EASTERN MT AND ND
BORDER WITH A SOUTHWEST FLOW ALOFT WHICH GENERALLY ALLOWS FOR SOME
THUNDERSTORMS TO FORM. NO BIG EVENT EXPECTED AT THIS TIME JUST
GENERAL THUNDERSTORMS. OTHERWISE TUESDAY NIGHT INTO WEDNESDAY
NIGHT IS THE EVENT OF INTEREST IN THE EXTENDED AND HAVE INCREASED
POPS A BIT ALONG THE CANADIAN BORDER AND NORTH DAKOTA BORDER
AREAS. FRANSEN
SOUTHWEST FLOW ALOFT WILL BE OVER MONTANA THROUGH FRIDAY AND NOW
ARE A DAY LATER WITH MOVING THE WEST COAST UPPER TROUGH INLAND
(FRIDAY NIGHT VERSUS THURSDAY NIGHT). WITHIN THE SOUTHWEST FLOW
ALOFT...A SHORTWAVE TUESDAY NIGHT INTO WEDNESDAY WILL BRING A
CHANCE OF SHOWERS AND THUNDERSTORMS TO THE FORECAST AREA. THEN THE
RIDGE OVER THE CENTRAL U.S. STRENGTHENS AND WARMS TEMPERATURES
INTO THE 90S FOR MOST OF THE AREA FOR THURSDAY AND FRIDAY. DRIER
AIRMASS WILL ALSO LIMIT PRECIP CHANCES ALTHOUGH WEAK WAVES COULD
BRING A SHOWER OR THUNDERSTORM WEDNESDAY NIGHT AND THURSDAY.
THE UPPER TROUGH MOVES INLAND FRIDAY AND THROUGH THE FORECAST AREA
FRIDAY NIGHT. WITH LIMITED MOISTURE...WILL MENTION A SLIGHT CHANCE
OF SHOWERS AND THUNDERSTORMS FOR NOW. THE WAVE WILL FLATTEN THE
RIDGE SO THAT THE FLOW ALOFT BECOMES ZONAL FOR NEXT WEEKEND WITH
DRY WEATHER. FORRESTER
&&
.AVIATION...
LOOK FOR VFR CONDITIONS TODAY AND TONIGHT WITH A MIX AND MID AND
HIGH LEVEL CLOUDS. MAY SEE SOME WIDELY SCATTERED SHOWERS OR
THUNDERSTORMS AFFECT THE TAF SITES BTWN 21Z THROUGH 05Z. EAST TO
SOUTHEAST WINDS EARLY THIS MORNING WILL DIMINISH AND TURN TO THE
WEST OR WEST- NORTHWEST AROUND 10 KTS AS A LOW PRESSURE SYSTEM
MOVES FROM EASTERN MT INTO WESTERN ND. FRANSEN
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1107 AM EDT SUN JUL 15 2012
.SYNOPSIS...
A SOUTHWESTERLY FLOW WILL BRING INCREASINGLY HUMID AIR INTO THE
REGION TODAY ALONG WITH SOME SHOWERS AND THUNDERSTORMS. A FEW STORMS
WILL CONTAIN LOCALLY HEAVY RAINFALL...BUT ANY HEAVIER RAIN AMOUNTS
WILL BE SPOTTY. A RIDGE OF HIGH PRESSURE WILL BUILD INTO THE LOWER
GREAT LAKES MONDAY WITH MAINLY DRY CONDITIONS.
&&
.NEAR TERM /THROUGH TONIGHT/...
TODAY THERE WILL BE SOME SPOTTY HEAVY RAIN AS CONVECTION MOVES
SLOWLY ACROSS THE AREA...HOWEVER COVERAGE OF THE BETTER RAINS WILL
BE TOO SPARSE TO OFFER MUCH RELIEF TO THE ONGOING DROUGHT. AS IS
OFTEN THE CASE...MODEL GUIDANCE IS STRUGGLING A BIT WITH
CONVECTION...WITH A FAIR SPREAD OF QPF SOLUTIONS BETWEEN THE
NAM/RGEM/GFS/EUROPEAN/SREF. THE HRRR HAS ALSO BEEN INCONSISTENT RUN
TO RUN ON SPECIFICS.
TWO MAIN AREAS OF RAIN ARE MOVING THROUGH THE AREA THIS MORNING. THE
FIRST IS NOW MOVING INTO CENTRAL NY AND OUT OF OUR CWA...WITH A
SECOND AREA OF SHOWERS MOVING INTO WESTERN NY. BOTH OF THESE AREAS
ARE WEAKENING IN INTENSITY AND AREAL COVERAGE...EXCEPT FOR THE
PORTION MOVING THROUGH CHAUTAUQUA COUNTY. EXPECT THIS TREND TO
CONTINUE THROUGH EARLY AFTERNOON...WITH HEAVY RAIN CONFINED TO THE
WESTERN SOUTHERN TIER...AND MUCH LIGHTER SHOWERS FOR THE REST OF THE
AREA. THE NORTH COUNTRY WILL REMAIN DRY THROUGH EARLY AFTERNOON
BEFORE A FEW SHOWERS POP UP LATER ON.
AS HAS BEEN THE CASE THE PAST TWO DAYS...THE FLOW ALOFT WILL BE
FAIRLY LIGHT. HOWEVER...TODAY THE PRECIPITABLE WATER VALUES WILL BE
SIGNIFICANTLY GREATER...BETWEEN 1.75 INCHES AND 2.00 INCHES. WITH
ANOMALOUSLY HIGH MOISTURE AVAILABLE IN THE COLUMN AND RELATIVELY
SLOW STORM MOTION...ANY OF THE STRONGER STORMS WILL LAY DOWN SOME
HEAVY RAIN IN ISOLATED AREAS WITH LOCAL AMOUNTS OF SEVERAL INCHES.
DESPITE THE LOCALLY HEAVY RAIN...MOST LOCATIONS WILL SEE LESS THAN A
QUARTER INCH WHICH WILL DO LITTLE OR NOTHING TO ALLEVIATE THE
PARCHED SOIL CONDITIONS.
THE UPPER TROF WILL SLOWLY MOVE ACROSS THE REGION BY THIS
EVENING...BUT BY THIS TIME...DRIER AIR SHOULD BE IN PLACE IN THE
BOUNDARY LAYER...SO SHOWER AND THUNDERSTORMS SHOULD TAPER OFF
AND/OR EXIT EAST. THE WEAK FRONTAL BOUNDARY ASSOCIATED WITH THE
TROF WILL NOT ACTUALLY CROSS THE REGION TONIGHT. THIS WILL KEEP
MOIST AIR IN PLACE...AND DEPENDING ON RAINFALL TODAY COULD RESULT
IN AREAS OF FOG TONIGHT.
TEMPERATURES WILL BE A BIT COOLER TODAY THAN THEY WERE
YESTERDAY...HOWEVER INCREASED MOISTURE WILL MAKE IT FEEL MORE MUGGY.
HIGHS SHOULD BE IN THE LOWER 80S NORTH OF THE THRU-WAY...BUT MAY
STAY IN THE UPPER 70S IN THE SOUTHERN TIER WHERE CLOUDS AND SHOWERS
SHOULD LIMIT TEMPERATURES A BIT. FOR TONIGHT...LOWS WILL RANGE FROM
THE LOWER 60S IN THE SOUTHERN TIER...TO AROUND 70 IN THE
BUFFALO/ROCHESTER METRO AREAS.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
DURING THE COURSE OF MONDAY...THE AXIS OF A WEAK UPPER LEVEL TROUGH
DRAPED FROM THE NEW ENGLAND COAST TO THE MID ATLANTIC STATES WILL
SLIDE OUT TO SEA...ALLOWING THE LEADING EDGE OF BROAD/FLAT UPPER
RIDGING TO EDGE NORTHEAST INTO THE LOWER LAKES. MEANWHILE AT THE
SURFACE...LINGERING WEAK TROUGHINESS ACROSS THE LOWER LAKES AT THE
START OF THE DAY WILL ALSO SLIDE EASTWARD...GIVING WAY TO MODEST LOW
LEVEL RIDGING DURING THE AFTERNOON.
GIVEN THESE DEVELOPMENTS...EXPECT THAT MONDAY SHOULD LARGELY BE
ANOTHER DRY AND HOT/HUMID DAY...WITH 850 MB TEMPS OF +16C/+17C AGAIN
SUPPORTING WIDESPREAD HIGHS IN THE UPPER 80S/LOWER 90S GIVEN WHAT
SHOULD BE A DECENT AMOUNT OF SUNSHINE. WHILE BOTH THE GFS AND ECMWF
BOTH SPIT OUT SOME LIGHT QPF ACROSS THE AREA PRIOR TO THE DEPARTURE
OF THE LOW LEVEL TROUGH...BELIEVE THAT THIS IS OVERDONE GIVEN ONLY
WEAK LINGERING FORCING AND FAIRLY WARM MID LEVEL TEMPS...WHICH
SHOULD HELP TO KEEP ANY PRECIP ISOLATED IN COVERAGE AT BEST. HAVE
THEREFORE KEPT POPS AT THE VERY LOW END OF THE SLIGHT CHANCE RANGE
OR BELOW ON MONDAY.
MONDAY NIGHT...BROAD/FLAT UPPER RIDGING WILL REMAIN INTACT ACROSS
MUCH OF THE AREA...WHILE A SLOW MOVING COLD FRONTAL BOUNDARY OVER
CENTRAL ONTARIO PROVINCE SAGS SOUTHWARD INTO THE UPPER LAKES AND
SOUTHERN ONTARIO. WHILE I CANNOT TOTALLY RULE OUT SOME ASSOCIATED
ISOLATED CONVECTION SNEAKING INTO THE SAINT LAWRENCE VALLEY TOWARD
DAYBREAK ON TUESDAY...IT DOES APPEAR THAT THE FRONT WILL REMAIN FAR
ENOUGH TO OUR NORTH AND THAT WE WILL REMAIN CAPPED ENOUGH FOR MAINLY
DRY WEATHER TO CONTINUE AREAWIDE. WITH NO AIRMASS CHANGE AND AN
INCREASING SOUTHWESTERLY LOW LEVEL FLOW EXPECTED WITH TIME IN
RESPONSE TO THE APPROACHING FRONT...EXPECT DOWNRIGHT SULTRY
TEMPERATURES WITH OVERNIGHT LOWS RANGING FROM THE MID AND UPPER 60S
ACROSS INTERIOR SECTIONS...TO THE LOWER 70S ACROSS THE LAKE PLAINS.
ON TUESDAY...THE AFOREMENTIONED FRONT WILL CONTINUE TO SLOWLY SAG
SOUTH TOWARD OUR REGION...WITH NOTABLE TIMING DIFFERENCES SEEN
AMONGST THE VARIOUS GUIDANCE PACKAGES. THE 00Z NAM IS AN EXTREMELY
FAST OUTLIER THAT BRINGS THE FRONT COMPLETELY THROUGH THE AREA BY
THE END OF THE DAY...WHICH SEEMS HIGHLY UNLIKELY GIVEN ITS
NEAR-PARALLEL ORIENTATION TO THE UPPER LEVEL FLOW...NOT TO MENTION
THE PROPENSITY FOR SUCH BOUNDARIES TO GET HUNG UP ACROSS THE LOWER
LAKES AT THIS TIME OF YEAR. FOR THIS REASON...HAVE COMPLETELY
DISREGARDED THIS SOLUTION. OF THE REMAINING GUIDANCE...THE GFS
REMAINS A BIT ON THE FASTER SIDE THOUGH NOT AS FAST AS ITS PREVIOUS
RUNS...BRINGING THE BOUNDARY INTO NORTHERN NEW YORK/LAKE ONTARIO BY
THE END OF THE DAY...WHICH IS CLOSE ENOUGH TO GENERATE SOME
CONVECTION ACROSS BOTH THE NORTH COUNTRY AND NIAGARA/ORLEANS
COUNTIES. MEANWHILE...THE VERY CONSISTENT ECMWF REMAINS A TOUCH
SLOWER THAN THE GFS AND ONLY BRINGS A RISK OF CONVECTION INTO THE
NORTH COUNTRY...WITH THE 00Z GEM GLOBAL A BIT SLOWER STILL. AT THIS
JUNCTURE...FEEL A COMPROMISE BETWEEN THE GFS/ECMWF REPRESENTS THE
MOST PLAUSIBLE SCENARIO...WHICH WOULD BRING AT LEAST A LOW TO MODEST
CHANCE OF CONVECTION TO LAKE ONTARIO AND THE NORTH COUNTRY BY LATE
IN THE DAY.
FURTHER TO THE SOUTH...CONDITIONS SHOULD REMAIN DRY THROUGH THE DAY
ON TUESDAY...THANKS TO BOTH GREATER DISTANCE FROM THE FRONT AND
STRONG MID LEVEL CAPPING...AS EVEN HOTTER AIR RIDES EAST ALONG THE
PERIPHERY OF THE MAIN UPPER LEVEL RIDGE. A CONSENSUS OF THE
GFS/GEM/ECMWF SUPPORTS 850 MB TEMPS RISING TO THE +20/+21C RANGE
AREAWIDE DURING THE COURSE OF TUESDAY...AND THIS COUPLED WITH GOOD
MIXING AND A DECENT AMOUNT OF SUN WILL LIKELY RESULT IN A REAL
SCORCHER OF A DAY SOUTH OF LAKE ONTARIO. AT THIS POINT...WIDESPREAD
HIGHS IN THE LOWER TO MID 90S APPEAR TO BE A SOLID BET...WITH UPPER
90S NOT AT ALL OUT OF THE QUESTION FOR THE NORMAL HOT SPOTS IN
INTERIOR PORTIONS OF OUR CWA. COUPLED WITH DEWPOINTS IN THE MID TO
UPPER 60S...SOME LOCATIONS SOUTH OF LAKE ONTARIO COULD SEE APPARENT
TEMPERATURES REACHING THE 100 DEGREE MARK TUESDAY AFTERNOON...WHICH
WOULD NECESSITATE THE ISSUANCE OF A HEAT ADVISORY. AS IT REMAINS FAR
TOO EARLY FOR THAT...FOR NOW WILL JUST MENTION THIS POTENTIAL IN THE
HWO. EAST OF LAKE ONTARIO...SOMEWHAT GREATER AMOUNTS OF CLOUD COVER
WILL LIKELY HELP KEEP TEMPS A LITTLE COOLER...THOUGH IT SHOULD STILL
BE UNCOMFORTABLY HOT EVEN THERE WITH HIGHS IN THE UPPER 80S TO LOWER
90S.
TUESDAY NIGHT AND WEDNESDAY...THE COLD FRONT WILL SLOWLY SAG SOUTH
ACROSS THE REGION...BRINGING A RISK OF CONVECTION TO THE ENTIRE
CWA...ALONG WITH THE POTENTIAL FOR LOCALLY HEAVY RAINFALL GIVEN
PRECIPITABLE WATER VALUES IN THE VICINITY OF AROUND 2 INCHES. AT
THIS JUNCTURE...THE TIMING OF THIS BOUNDARY REMAINS AN ISSUE WITH
THE GFS REMAINING THE FASTEST...THE CANADIAN THE SLOWEST...AND THE
ECMWF IN THE MIDDLE...WITH FROPA TIMES RANGING BETWEEN EARLY TO MID
WEDNESDAY MORNING AND WEDNESDAY AFTERNOON. GIVEN THAT THIS FRONT
APPEARS TO BE ANAFRONTAL WITH MOST OF ITS PRECIP FALLING BEHIND THE
ACTUAL SURFACE BOUNDARY...THIS MEANS THAT ANY ASSOCIATED CONVECTION
COULD END AS EARLY AS SOMETIME WEDNESDAY MORNING...OR AS LATE AS THE
END OF THE DAY WEDNESDAY.
GIVEN THE CONTINUED UNCERTAINTIES IN TIMING AND THE AFOREMENTIONED
NEAR-PARALLEL ORIENTATION OF THE FRONT TO THE UPPER FLOW...FEEL IT
IS BEST TO SLOW DOWN THE TIMING OF THIS FRONT AND ITS ASSOCIATED
CONVECTION A BIT FROM THE PREVIOUS FORECAST...FAVORING A COMPROMISE
SOLUTION ALONG THE LINES OF THE ECMWF. AS A RESULT...CHANCES FOR
CONVECTION WILL BE IN PLACE FROM TUESDAY NIGHT THROUGH WEDNESDAY
MORNING ACROSS THE ENTIRE AREA...BEFORE DIMINISHING FROM NORTH TO
SOUTH DURING THE COURSE OF WEDNESDAY AFTERNOON. TEMPERATURE-WISE...
EXPECT ANOTHER SULTRY NIGHT IN ADVANCE OF THE FRONT TUESDAY NIGHT
WITH LOWS AGAIN RANGING FROM THE UPPER 60S TO LOWER 70S...FOLLOWED
BY SOMEWHAT COOLER HIGHS IN THE UPPER 70S TO MID 80S ON WEDNESDAY
GIVEN THE PASSAGE OF THE FRONT AND ITS ASSOCIATED CLOUD COVER/PRECIP.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
SIMPLY PUT...SPRAWLING CANADIAN HIGH PRESSURE WILL BUILD SOUTHEAST
ACROSS THE GREAT LAKES AND NORTHEAST DURING THIS PERIOD...BRINGING A
RETURN TO DRY WEATHER ALONG WITH A COOLER AND NOTICEABLY LESS HUMID
AIRMASS.
IN TERMS OF ACTUAL TEMPERATURES...EXPECT DAILY HIGHS TO FALL BACK
INTO THE MID 70S TO LOWER 80S FOR BOTH THURSDAY AND FRIDAY...BEFORE
WARMING BACK INTO THE LOWER TO MID 80S ON SATURDAY AS WARMING
COMMENCES ALOFT. MEANWHILE...NIGHTTIME LOWS WILL RANGE IN THE MID
50S TO LOWER 60S ALL THREE NIGHTS. HUMIDITY LEVELS WILL ALSO BE MUCH
MORE COMFORTABLE...WITH DEWPOINTS REMAINING IN THE MID TO UPPER 50S
DURING THE BULK OF THE PERIOD.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
AN AREA OF SHOWERS WILL CONTINUE TO MOVE EAST ACROSS THE REGION
THROUGH EARLY AFTERNOON. THUNDERSTORM COVERAGE IS VERY SPARSE
RIGHT NOW WITH JUST SOME STRIKES NEAR THE PA SATE LINE WHICH WILL
IMPACT KJHW FOR THE NEXT HOUR OR TWO. THIS AFTERNOON WITH SOME
LIMITED DAYTIME HEATING EXPECT SCATTERED STORMS TO DEVELOP ONCE
AGAIN...MAINLY ACROSS THE SOUTHERN TIER INTO THE FINGER LAKES AND
CENTRAL NY. EXPECT MAINLY VFR AND MVFR CONDITIONS MOST OF THE TIME
IN THE LIGHT RAIN...BUT ANY EMBEDDED THUNDERSTORMS WILL PRODUCE
LOCALIZED IFR.
AFTERWARD...EXPECT A GENERAL CLEARING TREND FROM WEST TO EAST
LATE THIS AFTERNOON AND EVENING. THIS SHOULD RESULT IN MAINLY VFR
CONDITIONS...BUT THERE WILL BE AN INCREASING CHANCE FOR FOG
OVERNIGHT. THE COMBINATION OF LIGHT WINDS AND LINGERING BOUNDARY
LAYER MOISTURE MAY RESULT IN FAIRLY WIDESPREAD FOG. WINDS MAY
LIMIT HOW LOW VSBY DROPS AT BUF/IAG/ROC/ART...BUT DENSE FOG MAY
DEVELOP AT JHW...IN A RELATIVELY LIGHT FLOW.
OUTLOOK...
MONDAY AND TUESDAY...MAINLY VFR.
TUESDAY NIGHT...AREAS OF MVFR IN SCATTERED -SHRA/-TSRA.
WEDNESDAY...BECOMING VFR.
THURSDAY...VFR.
&&
.MARINE...
HIGH PRESSURE WILL REMAIN ANCHORED ALONG THE MID ATLANTIC COAST
THROUGH EARLY NEXT WEEK. MEANWHILE A WEAK TROUGH WILL APPROACH THE
LOWER LAKES TODAY AND ALLOW SOUTHWEST WINDS TO INCREASE
SOMEWHAT TO THE 10-15 KNOT RANGE...WITH THE STRONGEST WINDS ON LAKE
ERIE. EXPECT CONDITIONS TO REMAIN BELOW SMALL CRAFT CRITERIA...BUT
WAVES MAY GET A LITTLE CHOPPY ON LAKE ERIE.
A RIDGE OF HIGH PRESSURE WILL NOSE INTO THE LOWER LAKES MONDAY WITH
RELATIVELY LIGHT WINDS. SOUTHWEST WINDS WILL PICK UP AGAIN TUESDAY
AHEAD OF A STRONGER COLD FRONT...ESPECIALLY ON LAKE ERIE WHERE
CONDITIONS MAY APPROACH SMALL CRAFT ADVISORY CRITERIA.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL/HITCHCOCK
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL/HITCHCOCK
MARINE...APFFEL/JJR
AREA FORECAST DISCUSSION
NWS BUFFALO NY
757 AM EDT SUN JUL 15 2012
.SYNOPSIS...
A SOUTHWESTERLY FLOW WILL BRING INCREASINGLY HUMID AIR INTO THE REGION
TODAY ALONG WITH SOME SHOWERS AND THUNDERSTORMS. A FEW STORMS WILL
CONTAIN LOCALLY HEAVY RAINFALL...BUT ANY HEAVIER RAIN AMOUNTS WILL
BE SPOTTY. A RIDGE OF HIGH PRESSURE WILL BUILD INTO THE LOWER GREAT
LAKES MONDAY WITH MAINLY DRY CONDITIONS.
&&
.NEAR TERM /THROUGH TONIGHT/...
TODAY WILL BRING AN OPPORTUNITY FOR DROUGHT RELIEF...HOWEVER SHOWERS
AND THUNDERSTORMS WILL BE PATCHY IN NATURE...SO MANY COULD MISS
OUT. AS IS OFTEN THE CASE...MODEL GUIDANCE IS STRUGGLING A BIT
WITH CONVECTION...WITH A FAIR SPREAD OF QPF SOLUTIONS BETWEEN THE
NAM/RGEM/GFS/EUROPEAN/SREF. THE HRRR HAS ALSO BEEN INCONSISTENT
RUN TO RUN ON SPECIFICS.
DESPITE THE DIFFERENCES...THERE SEEMS TO BE A FAIR CONSENSUS THAT THE MOST
SIGNIFICANT RAINS WILL COME LATE MORNING AND EARLY AFTERNOON.
EARLY MORNING RADAR TRENDS ARE BEGINNING TO SUPPORT THIS...AS
SHOWERS AND THUNDERSTORMS EXPAND ACROSS LAKE ERIE AND SOUTHERN
ONTARIO. IT APPEARS THE TRIGGER TO THIS IS A COMBINATION OF MOIST
AIR IN THE BOUNDARY LAYER...AND THE CYCLONIC FLOW OUT AHEAD OF AN
APPROACHING UPPER TROF. FOLLOWING MODEL GUIDANCE AND RADAR
TRENDS...IT APPEARS STEADIEST RAINS WILL BE SOUTH OF LAKE
ONTARIO...ESPECIALLY IN THE SOUTHERN TIER AND FINGER LAKES
REGIONS.
AS HAS BEEN THE CASE THE PAST TWO DAYS...THE FLOW ALOFT WILL BE
FAIRLY LIGHT. HOWEVER...TODAY THE PRECIPITABLE WATER VALUES WILL BE
SIGNIFICANTLY GREATER...BETWEEN 1.75 INCHES AND 2.00 INCHES. IF IT
WERE NOT FOR THE VERY DRY CONDITIONS IN PLACE...THIS WOULD POSE A
GREATER FLOODING THREAT...BUT EVEN STILL THERE IS A REAL POTENTIAL
FOR FLOODING ALBEIT LOCALIZED. HAVE THE MOST CONCERN FOR THE
SOUTHERN TIER...WHERE TERRAIN CAN FUNNEL RUNOFF. DUE TO THE HIT OR
MISS NATURE OF CONVECTION...MEAN QPFS COULD BE A BIT MISLEADING.
WHILE BASIN-WIDE QPF FORECASTS RANGE FROM NEAR A HALF INCH EXPECTED
IN THE SOUTHERN TIER DOWN TO A TENTH OF AN INCH NORTH AND WEST OF
I-90...RAINFALL BY LOCATION SHOULD VARY SIGNIFICANTLY.
THE UPPER TROF WILL SLOWLY MOVE ACROSS THE REGION BY THIS
EVENING...BUT BY THIS TIME...DRIER AIR SHOULD BE IN PLACE IN THE
BOUNDARY LAYER...SO SHOWER AND THUNDERSTORMS SHOULD TAPER OFF
AND/OR EXIT EAST. THE WEAK FRONTAL BOUNDARY ASSOCIATED WITH THE
TROF WILL NOT ACTUALLY CROSS THE REGION TONIGHT. THIS WILL KEEP
MOIST AIR IN PLACE...AND DEPENDING ON RAINFALL TODAY COULD RESULT
IN AREAS OF FOG TONIGHT.
TEMPERATURES WILL BE A BIT COOLER TODAY THAN THEY WERE
YESTERDAY...HOWEVER INCREASED MOISTURE WILL MAKE IT FEEL MORE MUGGY.
HIGHS SHOULD BE IN THE LOWER 80S NORTH OF THE THRU-WAY...BUT MAY
STAY IN THE UPPER 70S IN THE SOUTHERN TIER WHERE CLOUDS AND SHOWERS
SHOULD LIMIT TEMPERATURES A BIT. FOR TONIGHT...LOWS WILL RANGE FROM
THE LOWER 60S IN THE SOUTHERN TIER...TO AROUND 70 IN THE
BUFFALO/ROCHESTER METRO AREAS.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
DURING THE COURSE OF MONDAY...THE AXIS OF A WEAK UPPER LEVEL TROUGH
DRAPED FROM THE NEW ENGLAND COAST TO THE MID ATLANTIC STATES WILL
SLIDE OUT TO SEA...ALLOWING THE LEADING EDGE OF BROAD/FLAT UPPER
RIDGING TO EDGE NORTHEAST INTO THE LOWER LAKES. MEANWHILE AT THE
SURFACE...LINGERING WEAK TROUGHINESS ACROSS THE LOWER LAKES AT THE
START OF THE DAY WILL ALSO SLIDE EASTWARD...GIVING WAY TO MODEST LOW
LEVEL RIDGING DURING THE AFTERNOON.
GIVEN THESE DEVELOPMENTS...EXPECT THAT MONDAY SHOULD LARGELY BE
ANOTHER DRY AND HOT/HUMID DAY...WITH 850 MB TEMPS OF +16C/+17C AGAIN
SUPPORTING WIDESPREAD HIGHS IN THE UPPER 80S/LOWER 90S GIVEN WHAT
SHOULD BE A DECENT AMOUNT OF SUNSHINE. WHILE BOTH THE GFS AND ECMWF
BOTH SPIT OUT SOME LIGHT QPF ACROSS THE AREA PRIOR TO THE DEPARTURE
OF THE LOW LEVEL TROUGH...BELIEVE THAT THIS IS OVERDONE GIVEN ONLY
WEAK LINGERING FORCING AND FAIRLY WARM MID LEVEL TEMPS...WHICH
SHOULD HELP TO KEEP ANY PRECIP ISOLATED IN COVERAGE AT BEST. HAVE
THEREFORE KEPT POPS AT THE VERY LOW END OF THE SLIGHT CHANCE RANGE
OR BELOW ON MONDAY.
MONDAY NIGHT...BROAD/FLAT UPPER RIDGING WILL REMAIN INTACT ACROSS
MUCH OF THE AREA...WHILE A SLOW MOVING COLD FRONTAL BOUNDARY OVER
CENTRAL ONTARIO PROVINCE SAGS SOUTHWARD INTO THE UPPER LAKES AND
SOUTHERN ONTARIO. WHILE I CANNOT TOTALLY RULE OUT SOME ASSOCIATED
ISOLATED CONVECTION SNEAKING INTO THE SAINT LAWRENCE VALLEY TOWARD
DAYBREAK ON TUESDAY...IT DOES APPEAR THAT THE FRONT WILL REMAIN FAR
ENOUGH TO OUR NORTH AND THAT WE WILL REMAIN CAPPED ENOUGH FOR MAINLY
DRY WEATHER TO CONTINUE AREAWIDE. WITH NO AIRMASS CHANGE AND AN
INCREASING SOUTHWESTERLY LOW LEVEL FLOW EXPECTED WITH TIME IN
RESPONSE TO THE APPROACHING FRONT...EXPECT DOWNRIGHT SULTRY
TEMPERATURES WITH OVERNIGHT LOWS RANGING FROM THE MID AND UPPER 60S
ACROSS INTERIOR SECTIONS...TO THE LOWER 70S ACROSS THE LAKE PLAINS.
ON TUESDAY...THE AFOREMENTIONED FRONT WILL CONTINUE TO SLOWLY SAG
SOUTH TOWARD OUR REGION...WITH NOTABLE TIMING DIFFERENCES SEEN
AMONGST THE VARIOUS GUIDANCE PACKAGES. THE 00Z NAM IS AN EXTREMELY
FAST OUTLIER THAT BRINGS THE FRONT COMPLETELY THROUGH THE AREA BY
THE END OF THE DAY...WHICH SEEMS HIGHLY UNLIKELY GIVEN ITS
NEAR-PARALLEL ORIENTATION TO THE UPPER LEVEL FLOW...NOT TO MENTION
THE PROPENSITY FOR SUCH BOUNDARIES TO GET HUNG UP ACROSS THE LOWER
LAKES AT THIS TIME OF YEAR. FOR THIS REASON...HAVE COMPLETELY
DISREGARDED THIS SOLUTION. OF THE REMAINING GUIDANCE...THE GFS
REMAINS A BIT ON THE FASTER SIDE THOUGH NOT AS FAST AS ITS PREVIOUS
RUNS...BRINGING THE BOUNDARY INTO NORTHERN NEW YORK/LAKE ONTARIO BY
THE END OF THE DAY...WHICH IS CLOSE ENOUGH TO GENERATE SOME
CONVECTION ACROSS BOTH THE NORTH COUNTRY AND NIAGARA/ORLEANS
COUNTIES. MEANWHILE...THE VERY CONSISTENT ECMWF REMAINS A TOUCH
SLOWER THAN THE GFS AND ONLY BRINGS A RISK OF CONVECTION INTO THE
NORTH COUNTRY...WITH THE 00Z GEM GLOBAL A BIT SLOWER STILL. AT THIS
JUNCTURE...FEEL A COMPROMISE BETWEEN THE GFS/ECMWF REPRESENTS THE
MOST PLAUSIBLE SCENARIO...WHICH WOULD BRING AT LEAST A LOW TO MODEST
CHANCE OF CONVECTION TO LAKE ONTARIO AND THE NORTH COUNTRY BY LATE
IN THE DAY.
FURTHER TO THE SOUTH...CONDITIONS SHOULD REMAIN DRY THROUGH THE DAY
ON TUESDAY...THANKS TO BOTH GREATER DISTANCE FROM THE FRONT AND
STRONG MID LEVEL CAPPING...AS EVEN HOTTER AIR RIDES EAST ALONG THE
PERIPHERY OF THE MAIN UPPER LEVEL RIDGE. A CONSENSUS OF THE
GFS/GEM/ECMWF SUPPORTS 850 MB TEMPS RISING TO THE +20/+21C RANGE
AREAWIDE DURING THE COURSE OF TUESDAY...AND THIS COUPLED WITH GOOD
MIXING AND A DECENT AMOUNT OF SUN WILL LIKELY RESULT IN A REAL
SCORCHER OF A DAY SOUTH OF LAKE ONTARIO. AT THIS POINT...WIDESPREAD
HIGHS IN THE LOWER TO MID 90S APPEAR TO BE A SOLID BET...WITH UPPER
90S NOT AT ALL OUT OF THE QUESTION FOR THE NORMAL HOT SPOTS IN
INTERIOR PORTIONS OF OUR CWA. COUPLED WITH DEWPOINTS IN THE MID TO
UPPER 60S...SOME LOCATIONS SOUTH OF LAKE ONTARIO COULD SEE APPARENT
TEMPERATURES REACHING THE 100 DEGREE MARK TUESDAY AFTERNOON...WHICH
WOULD NECESSITATE THE ISSUANCE OF A HEAT ADVISORY. AS IT REMAINS FAR
TOO EARLY FOR THAT...FOR NOW WILL JUST MENTION THIS POTENTIAL IN THE
HWO. EAST OF LAKE ONTARIO...SOMEWHAT GREATER AMOUNTS OF CLOUD COVER
WILL LIKELY HELP KEEP TEMPS A LITTLE COOLER...THOUGH IT SHOULD STILL
BE UNCOMFORTABLY HOT EVEN THERE WITH HIGHS IN THE UPPER 80S TO LOWER
90S.
TUESDAY NIGHT AND WEDNESDAY...THE COLD FRONT WILL SLOWLY SAG SOUTH
ACROSS THE REGION...BRINGING A RISK OF CONVECTION TO THE ENTIRE
CWA...ALONG WITH THE POTENTIAL FOR LOCALLY HEAVY RAINFALL GIVEN
PRECIPITABLE WATER VALUES IN THE VICINITY OF AROUND 2 INCHES. AT
THIS JUNCTURE...THE TIMING OF THIS BOUNDARY REMAINS AN ISSUE WITH
THE GFS REMAINING THE FASTEST...THE CANADIAN THE SLOWEST...AND THE
ECMWF IN THE MIDDLE...WITH FROPA TIMES RANGING BETWEEN EARLY TO MID
WEDNESDAY MORNING AND WEDNESDAY AFTERNOON. GIVEN THAT THIS FRONT
APPEARS TO BE ANAFRONTAL WITH MOST OF ITS PRECIP FALLING BEHIND THE
ACTUAL SURFACE BOUNDARY...THIS MEANS THAT ANY ASSOCIATED CONVECTION
COULD END AS EARLY AS SOMETIME WEDNESDAY MORNING...OR AS LATE AS THE
END OF THE DAY WEDNESDAY.
GIVEN THE CONTINUED UNCERTAINTIES IN TIMING AND THE AFOREMENTIONED
NEAR-PARALLEL ORIENTATION OF THE FRONT TO THE UPPER FLOW...FEEL IT
IS BEST TO SLOW DOWN THE TIMING OF THIS FRONT AND ITS ASSOCIATED
CONVECTION A BIT FROM THE PREVIOUS FORECAST...FAVORING A COMPROMISE
SOLUTION ALONG THE LINES OF THE ECMWF. AS A RESULT...CHANCES FOR
CONVECTION WILL BE IN PLACE FROM TUESDAY NIGHT THROUGH WEDNESDAY
MORNING ACROSS THE ENTIRE AREA...BEFORE DIMINISHING FROM NORTH TO
SOUTH DURING THE COURSE OF WEDNESDAY AFTERNOON. TEMPERATURE-WISE...
EXPECT ANOTHER SULTRY NIGHT IN ADVANCE OF THE FRONT TUESDAY NIGHT
WITH LOWS AGAIN RANGING FROM THE UPPER 60S TO LOWER 70S...FOLLOWED
BY SOMEWHAT COOLER HIGHS IN THE UPPER 70S TO MID 80S ON WEDNESDAY
GIVEN THE PASSAGE OF THE FRONT AND ITS ASSOCIATED CLOUD COVER/PRECIP.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
SIMPLY PUT...SPRAWLING CANADIAN HIGH PRESSURE WILL BUILD SOUTHEAST
ACROSS THE GREAT LAKES AND NORTHEAST DURING THIS PERIOD...BRINGING A
RETURN TO DRY WEATHER ALONG WITH A COOLER AND NOTICEABLY LESS HUMID
AIRMASS.
IN TERMS OF ACTUAL TEMPERATURES...EXPECT DAILY HIGHS TO FALL BACK
INTO THE MID 70S TO LOWER 80S FOR BOTH THURSDAY AND FRIDAY...BEFORE
WARMING BACK INTO THE LOWER TO MID 80S ON SATURDAY AS WARMING
COMMENCES ALOFT. MEANWHILE...NIGHTTIME LOWS WILL RANGE IN THE MID
50S TO LOWER 60S ALL THREE NIGHTS. HUMIDITY LEVELS WILL ALSO BE MUCH
MORE COMFORTABLE...WITH DEWPOINTS REMAINING IN THE MID TO UPPER 50S
DURING THE BULK OF THE PERIOD.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AN AREA OF SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE REGION
THROUGH MID-AFTERNOON. RADAR TRENDS SUGGEST MOST WIDESPREAD
SHOWERS WILL BE BETWEEN 15Z AND 21Z...WITH EMBEDDED THUNDERSTORM
ACTIVITY LIKELY. OUTSIDE OF THESE...EXPECT MAINLY VFR CONDITIONS.
SHOWERS AND THUNDERSTORMS MAY LOWER VSBY TO 2SM AT TIMES IN HEAVY RAINFALL.
AFTERWARD...EXPECT A GENERAL CLEARING TREND FROM WEST TO EAST LATE THIS
AFTERNOON AND EVENING. THIS SHOULD RESULT IN MAINLY VFR
CONDITIONS...BUT THERE WILL BE AN INCREASING CHANCE FOR FOG
OVERNIGHT. THE COMBINATION OF LIGHT WINDS AND LINGERING BOUNDARY
LAYER MOISTURE MAY RESULT IN FAIRLY WIDESPREAD FOG. WINDS MAY
LIMIT HOW LOW VSBY DROPS AT BUF/IAG/ROC/ART...BUT DENSE FOG MAY
DEVELOP AT JHW...IN A RELATIVELY LIGHT FLOW.
OUTLOOK...
MONDAY AND TUESDAY...MAINLY VFR.
TUESDAY NIGHT...AREAS OF MVFR IN SCATTERED -SHRA/-TSRA.
WEDNESDAY...BECOMING VFR.
THURSDAY...VFR.
&&
.MARINE...
HIGH PRESSURE WILL REMAIN ANCHORED ALONG THE MID ATLANTIC COAST
THROUGH EARLY NEXT WEEK. MEANWHILE A WEAK TROUGH WILL APPROACH THE
LOWER LAKES TODAY AND ALLOW SOUTHWEST WINDS TO INCREASE
SOMEWHAT TO THE 10-15 KNOT RANGE...WITH THE STRONGEST WINDS ON LAKE
ERIE. EXPECT CONDITIONS TO REMAIN BELOW SMALL CRAFT CRITERIA...BUT
WAVES MAY GET A LITTLE CHOPPY ON LAKE ERIE.
A RIDGE OF HIGH PRESSURE WILL NOSE INTO THE LOWER LAKES MONDAY WITH
RELATIVELY LIGHT WINDS. SOUTHWEST WINDS WILL PICK UP AGAIN TUESDAY
AHEAD OF A STRONGER COLD FRONT...ESPECIALLY ON LAKE ERIE WHERE
CONDITIONS MAY APPROACH SMALL CRAFT ADVISORY CRITERIA.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL
MARINE...APFFEL/JJR
AREA FORECAST DISCUSSION
NWS BUFFALO NY
552 AM EDT SUN JUL 15 2012
.SYNOPSIS...
A SOUTHWESTERLY FLOW WILL BRING INCREASINGLY HUMID AIR INTO THE REGION
TODAY ALONG WITH SOME SHOWERS AND THUNDERSTORMS. A FEW STORMS WILL
CONTAIN LOCALLY HEAVY RAINFALL...BUT ANY HEAVIER RAIN AMOUNTS WILL
BE SPOTTY. A RIDGE OF HIGH PRESSURE WILL BUILD INTO THE LOWER GREAT
LAKES MONDAY WITH MAINLY DRY CONDITIONS.
&&
.NEAR TERM /THROUGH TONIGHT/...
TODAY WILL BRING AN OPPORTUNITY FOR DROUGHT RELIEF...HOWEVER SHOWERS
AND THUNDERSTORMS WILL BE PATCHY IN NATURE...SO MANY COULD MISS OUT.
THERE APPEARS TO BE TWO FEATURES WHICH WILL KEY THIS ACTIVITY. THE
FIRST IS A MODEST 25 KT LOW LEVEL JET FOUND AT 925 MB...WHICH IS
KEYING THE ADVANCE OF LOW LEVEL MOISTURE. THE SECOND IS AN UPPER
LEVEL TROF AXIS...WHICH WILL CROSS THE REGION LATE AFTERNOON INTO
THIS EVENING.
AS IS OFTEN THE CASE...MODEL GUIDANCE IS STRUGGLING A BIT WITH
CONVECTION...WITH A FAIR SPREAD OF QPF SOLUTIONS BETWEEN THE
NAM/RGEM/GFS/EUROPEAN/SREF. THE HRRR HAS ALSO BEEN INCONSISTENT RUN TO
RUN AND HAS BEEN LATE IN CATCHING ON TO CONVECTION WHICH HAS
DEVELOPED. GIVEN THIS SCENARIO WILL TEND TO WEIGHT RADAR TRENDS
IN THE NEAR TERM...AND A SREF WEIGHTED ENSEMBLE OF AVAILABLE
GUIDANCE FROM LATE MORNING ON. THIS SUGGESTS FAIRLY MODEST SHOWER
ACTIVITY WILL MOVE ACROSS THE REGION THROUGH MID TO LATE
MORNING...WITH THE BEST CHANCE FOR THIS SOUTH OF LAKE ONTARIO.
EXPECT SHOWERS TO BE HIT AND MISS.
THERE SEEMS TO BE A FAIR CONSENSUS THAT THE MOST SIGNIFICANT RAINS
WILL COME LATE MORNING AND EARLY AFTERNOON. THIS MAKES SENSE GIVEN
THE APPROACH OF A SLOW MOVING UPPER LEVEL TROF AND THE
CONTRIBUTION OF DAYTIME HEATING. THIS WILL LIKELY BRING SHOWERS
AND THUNDERSTORMS TO THE SOUTHERN TIER AND INTO THE FINGER LAKES
REGION...AND PERHAPS ELSEWHERE THOUGH COVERAGE SHOULD BE A BIT
MORE SPARSE. CONVECTION WILL FORM ALONG ANY BOUNDARY IT CAN
FIND...BUT HAVE SOME CONCERN MUCH OF THE BUFFALO METRO AREA (AND
WATERTOWN FOR THAT MATTER) WILL MISS OUT IN A SOUTHWEST FLOW WHICH
CAN TEND TO SHADOW THE REGION FROM AFTERNOON CONVECTION.
AS HAS BEEN THE CASE THE PAST TWO DAYS...THE FLOW ALOFT WILL BE
FAIRLY LIGHT. HOWEVER...TODAY THE PRECIPITABLE WATER VALUES WILL BE
SIGNIFICANTLY GREATER...BETWEEN 1.75 INCHES AND 2.00 INCHES. IF IT
WERE NOT FOR THE VERY DRY CONDITIONS IN PLACE...THIS WOULD POSE A
GREATER FLOODING THREAT...BUT EVEN STILL THERE IS A REAL POTENTIAL
FOR FLOODING ALBEIT LOCALIZED. HAVE THE MOST CONCERN FOR THE
SOUTHERN TIER...WHERE TERRAIN CAN FUNNEL RUNOFF. DUE TO THE HIT OR
MISS NATURE OF CONVECTION...MEAN QPFS COULD BE A BIT MISLEADING.
WHILE BASIN-WIDE QPF FORECASTS RANGE FROM NEAR A HALF INCH EXPECTED
IN THE SOUTHERN TIER DOWN TO A TENTH OF AN INCH NORTH AND WEST OF
I-90...RAINFALL BY LOCATION SHOULD VARY SIGNIFICANTLY.
THE UPPER TROF WILL SLOWLY MOVE ACROSS THE REGION BY THIS
EVENING...BUT BY THIS TIME...DRIER AIR SHOULD BE IN PLACE IN THE
BOUNDARY LAYER...SO SHOWER AND THUNDERSTORMS SHOULD TAPER OFF
AND/OR EXIT EAST. THE WEAK FRONTAL BOUNDARY ASSOCIATED WITH THE
TROF WILL NOT ACTUALLY CROSS THE REGION TONIGHT. THIS WILL KEEP
MOIST AIR IN PLACE...AND DEPENDING ON RAINFALL TODAY COULD RESULT
IN AREAS OF FOG TONIGHT.
TEMPERATURES WILL BE A BIT COOLER TODAY THAN THEY WERE
YESTERDAY...HOWEVER INCREASED MOISTURE WILL MAKE IT FEEL MORE MUGGY.
HIGHS SHOULD BE IN THE LOWER 80S NORTH OF THE THRU-WAY...BUT MAY
STAY IN THE UPPER 70S IN THE SOUTHERN TIER WHERE CLOUDS AND SHOWERS
SHOULD LIMIT TEMPERATURES A BIT. FOR TONIGHT...LOWS WILL RANGE FROM
THE LOWER 60S IN THE SOUTHERN TIER...TO AROUND 70 IN THE
BUFFALO/ROCHESTER METRO AREAS.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
DURING THE COURSE OF MONDAY...THE AXIS OF A WEAK UPPER LEVEL TROUGH
DRAPED FROM THE NEW ENGLAND COAST TO THE MID ATLANTIC STATES WILL
SLIDE OUT TO SEA...ALLOWING THE LEADING EDGE OF BROAD/FLAT UPPER
RIDGING TO EDGE NORTHEAST INTO THE LOWER LAKES. MEANWHILE AT THE
SURFACE...LINGERING WEAK TROUGHINESS ACROSS THE LOWER LAKES AT THE
START OF THE DAY WILL ALSO SLIDE EASTWARD...GIVING WAY TO MODEST LOW
LEVEL RIDGING DURING THE AFTERNOON.
GIVEN THESE DEVELOPMENTS...EXPECT THAT MONDAY SHOULD LARGELY BE
ANOTHER DRY AND HOT/HUMID DAY...WITH 850 MB TEMPS OF +16C/+17C AGAIN
SUPPORTING WIDESPREAD HIGHS IN THE UPPER 80S/LOWER 90S GIVEN WHAT
SHOULD BE A DECENT AMOUNT OF SUNSHINE. WHILE BOTH THE GFS AND ECMWF
BOTH SPIT OUT SOME LIGHT QPF ACROSS THE AREA PRIOR TO THE DEPARTURE
OF THE LOW LEVEL TROUGH...BELIEVE THAT THIS IS OVERDONE GIVEN ONLY
WEAK LINGERING FORCING AND FAIRLY WARM MID LEVEL TEMPS...WHICH
SHOULD HELP TO KEEP ANY PRECIP ISOLATED IN COVERAGE AT BEST. HAVE
THEREFORE KEPT POPS AT THE VERY LOW END OF THE SLIGHT CHANCE RANGE
OR BELOW ON MONDAY.
MONDAY NIGHT...BROAD/FLAT UPPER RIDGING WILL REMAIN INTACT ACROSS
MUCH OF THE AREA...WHILE A SLOW MOVING COLD FRONTAL BOUNDARY OVER
CENTRAL ONTARIO PROVINCE SAGS SOUTHWARD INTO THE UPPER LAKES AND
SOUTHERN ONTARIO. WHILE I CANNOT TOTALLY RULE OUT SOME ASSOCIATED
ISOLATED CONVECTION SNEAKING INTO THE SAINT LAWRENCE VALLEY TOWARD
DAYBREAK ON TUESDAY...IT DOES APPEAR THAT THE FRONT WILL REMAIN FAR
ENOUGH TO OUR NORTH AND THAT WE WILL REMAIN CAPPED ENOUGH FOR MAINLY
DRY WEATHER TO CONTINUE AREAWIDE. WITH NO AIRMASS CHANGE AND AN
INCREASING SOUTHWESTERLY LOW LEVEL FLOW EXPECTED WITH TIME IN
RESPONSE TO THE APPROACHING FRONT...EXPECT DOWNRIGHT SULTRY
TEMPERATURES WITH OVERNIGHT LOWS RANGING FROM THE MID AND UPPER 60S
ACROSS INTERIOR SECTIONS...TO THE LOWER 70S ACROSS THE LAKE PLAINS.
ON TUESDAY...THE AFOREMENTIONED FRONT WILL CONTINUE TO SLOWLY SAG
SOUTH TOWARD OUR REGION...WITH NOTABLE TIMING DIFFERENCES SEEN
AMONGST THE VARIOUS GUIDANCE PACKAGES. THE 00Z NAM IS AN EXTREMELY
FAST OUTLIER THAT BRINGS THE FRONT COMPLETELY THROUGH THE AREA BY
THE END OF THE DAY...WHICH SEEMS HIGHLY UNLIKELY GIVEN ITS
NEAR-PARALLEL ORIENTATION TO THE UPPER LEVEL FLOW...NOT TO MENTION
THE PROPENSITY FOR SUCH BOUNDARIES TO GET HUNG UP ACROSS THE LOWER
LAKES AT THIS TIME OF YEAR. FOR THIS REASON...HAVE COMPLETELY
DISREGARDED THIS SOLUTION. OF THE REMAINING GUIDANCE...THE GFS
REMAINS A BIT ON THE FASTER SIDE THOUGH NOT AS FAST AS ITS PREVIOUS
RUNS...BRINGING THE BOUNDARY INTO NORTHERN NEW YORK/LAKE ONTARIO BY
THE END OF THE DAY...WHICH IS CLOSE ENOUGH TO GENERATE SOME
CONVECTION ACROSS BOTH THE NORTH COUNTRY AND NIAGARA/ORLEANS
COUNTIES. MEANWHILE...THE VERY CONSISTENT ECMWF REMAINS A TOUCH
SLOWER THAN THE GFS AND ONLY BRINGS A RISK OF CONVECTION INTO THE
NORTH COUNTRY...WITH THE 00Z GEM GLOBAL A BIT SLOWER STILL. AT THIS
JUNCTURE...FEEL A COMPROMISE BETWEEN THE GFS/ECMWF REPRESENTS THE
MOST PLAUSIBLE SCENARIO...WHICH WOULD BRING AT LEAST A LOW TO MODEST
CHANCE OF CONVECTION TO LAKE ONTARIO AND THE NORTH COUNTRY BY LATE
IN THE DAY.
FURTHER TO THE SOUTH...CONDITIONS SHOULD REMAIN DRY THROUGH THE DAY
ON TUESDAY...THANKS TO BOTH GREATER DISTANCE FROM THE FRONT AND
STRONG MID LEVEL CAPPING...AS EVEN HOTTER AIR RIDES EAST ALONG THE
PERIPHERY OF THE MAIN UPPER LEVEL RIDGE. A CONSENSUS OF THE
GFS/GEM/ECMWF SUPPORTS 850 MB TEMPS RISING TO THE +20/+21C RANGE
AREAWIDE DURING THE COURSE OF TUESDAY...AND THIS COUPLED WITH GOOD
MIXING AND A DECENT AMOUNT OF SUN WILL LIKELY RESULT IN A REAL
SCORCHER OF A DAY SOUTH OF LAKE ONTARIO. AT THIS POINT...WIDESPREAD
HIGHS IN THE LOWER TO MID 90S APPEAR TO BE A SOLID BET...WITH UPPER
90S NOT AT ALL OUT OF THE QUESTION FOR THE NORMAL HOT SPOTS IN
INTERIOR PORTIONS OF OUR CWA. COUPLED WITH DEWPOINTS IN THE MID TO
UPPER 60S...SOME LOCATIONS SOUTH OF LAKE ONTARIO COULD SEE APPARENT
TEMPERATURES REACHING THE 100 DEGREE MARK TUESDAY AFTERNOON...WHICH
WOULD NECESSITATE THE ISSUANCE OF A HEAT ADVISORY. AS IT REMAINS FAR
TOO EARLY FOR THAT...FOR NOW WILL JUST MENTION THIS POTENTIAL IN THE
HWO. EAST OF LAKE ONTARIO...SOMEWHAT GREATER AMOUNTS OF CLOUD COVER
WILL LIKELY HELP KEEP TEMPS A LITTLE COOLER...THOUGH IT SHOULD STILL
BE UNCOMFORTABLY HOT EVEN THERE WITH HIGHS IN THE UPPER 80S TO LOWER
90S.
TUESDAY NIGHT AND WEDNESDAY...THE COLD FRONT WILL SLOWLY SAG SOUTH
ACROSS THE REGION...BRINGING A RISK OF CONVECTION TO THE ENTIRE
CWA...ALONG WITH THE POTENTIAL FOR LOCALLY HEAVY RAINFALL GIVEN
PRECIPITABLE WATER VALUES IN THE VICINITY OF AROUND 2 INCHES. AT
THIS JUNCTURE...THE TIMING OF THIS BOUNDARY REMAINS AN ISSUE WITH
THE GFS REMAINING THE FASTEST...THE CANADIAN THE SLOWEST...AND THE
ECMWF IN THE MIDDLE...WITH FROPA TIMES RANGING BETWEEN EARLY TO MID
WEDNESDAY MORNING AND WEDNESDAY AFTERNOON. GIVEN THAT THIS FRONT
APPEARS TO BE ANAFRONTAL WITH MOST OF ITS PRECIP FALLING BEHIND THE
ACTUAL SURFACE BOUNDARY...THIS MEANS THAT ANY ASSOCIATED CONVECTION
COULD END AS EARLY AS SOMETIME WEDNESDAY MORNING...OR AS LATE AS THE
END OF THE DAY WEDNESDAY.
GIVEN THE CONTINUED UNCERTAINTIES IN TIMING AND THE AFOREMENTIONED
NEAR-PARALLEL ORIENTATION OF THE FRONT TO THE UPPER FLOW...FEEL IT
IS BEST TO SLOW DOWN THE TIMING OF THIS FRONT AND ITS ASSOCIATED
CONVECTION A BIT FROM THE PREVIOUS FORECAST...FAVORING A COMPROMISE
SOLUTION ALONG THE LINES OF THE ECMWF. AS A RESULT...CHANCES FOR
CONVECTION WILL BE IN PLACE FROM TUESDAY NIGHT THROUGH WEDNESDAY
MORNING ACROSS THE ENTIRE AREA...BEFORE DIMINISHING FROM NORTH TO
SOUTH DURING THE COURSE OF WEDNESDAY AFTERNOON. TEMPERATURE-WISE...
EXPECT ANOTHER SULTRY NIGHT IN ADVANCE OF THE FRONT TUESDAY NIGHT
WITH LOWS AGAIN RANGING FROM THE UPPER 60S TO LOWER 70S...FOLLOWED
BY SOMEWHAT COOLER HIGHS IN THE UPPER 70S TO MID 80S ON WEDNESDAY
GIVEN THE PASSAGE OF THE FRONT AND ITS ASSOCIATED CLOUD COVER/PRECIP.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
SIMPLY PUT...SPRAWLING CANADIAN HIGH PRESSURE WILL BUILD SOUTHEAST
ACROSS THE GREAT LAKES AND NORTHEAST DURING THIS PERIOD...BRINGING A
RETURN TO DRY WEATHER ALONG WITH A COOLER AND NOTICEABLY LESS HUMID
AIRMASS.
IN TERMS OF ACTUAL TEMPERATURES...EXPECT DAILY HIGHS TO FALL BACK
INTO THE MID 70S TO LOWER 80S FOR BOTH THURSDAY AND FRIDAY...BEFORE
WARMING BACK INTO THE LOWER TO MID 80S ON SATURDAY AS WARMING
COMMENCES ALOFT. MEANWHILE...NIGHTTIME LOWS WILL RANGE IN THE MID
50S TO LOWER 60S ALL THREE NIGHTS. HUMIDITY LEVELS WILL ALSO BE MUCH
MORE COMFORTABLE...WITH DEWPOINTS REMAINING IN THE MID TO UPPER 50S
DURING THE BULK OF THE PERIOD.
&&
.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
THE THREAT FOR SHOWERS AND THUNDERSTORMS WILL INCREASE FROM SW TO NE
BETWEEN 09Z AND 15Z AS A WEAK LOW LEVEL JET KEYS THE ADVANCE OF
MOIST AIR. RADAR SUGGESTS THESE STORMS WILL BE SCATTERED IN
NATURE...NOT IMPACTING ALL TAF SITES. MOISTURE IN THE LOW LAYERS
MAY LOWER JHW TO IFR OR LOWER EARLY THIS MORNING...BUT AN
APPROACHING THUNDERSTORM MAY MIX THIS OUT AROUND DAYBREAK.
BEHIND THIS INITIAL AREA OF SHOWERS AND THUNDERSTORMS WILL BE
ANOTHER OPPORTUNITY FOR CONVECTION WITH AN APPROACHING SHORTWAVE
THIS AFTERNOON. LAKE SHADOWING WILL DIMINISH THE POTENTIAL AT
BUF/IAG/ART...THOUGH THE LAKES ARE WARM ENOUGH THAT THUNDERSTORMS
CANNOT COMPLETELY BE RULED OUT AT ANY TAF LOCATION. THIS SAID...THE
BEST CHANCE FOR THUNDERSTORMS WILL BE OUT AHEAD OF THIS SHORTWAVE AT
JHW/ROC EARLY THIS AFTERNOON.
EXPECT A GENERAL CLEARING TREND FROM WEST TO EAST LATE THIS
AFTERNOON AND EVENING. THIS SHOULD RESULT IN MAINLY VFR
CONDITIONS...BUT THERE WILL BE AN INCREASING CHANCE FOR FOG
OVERNIGHT. THE COMBINATION OF LIGHT WINDS AND LINGERING BOUNDARY
LAYER MOISTURE MAY RESULT IN FAIRLY WIDESPREAD IFR OR LOWER
CONDITIONS LATE TONIGHT...ESPECIALLY IF SKIES CLEAR OUT.
OUTLOOK...
MONDAY AND TUESDAY...MAINLY VFR.
TUESDAY NIGHT...AREAS OF MVFR IN SCATTERED -SHRA/-TSRA.
WEDNESDAY...BECOMING VFR.
THURSDAY...VFR.
&&
.MARINE...
HIGH PRESSURE WILL REMAIN ANCHORED ALONG THE MID ATLANTIC COAST
THROUGH EARLY NEXT WEEK. MEANWHILE A WEAK TROUGH WILL APPROACH THE
LOWER LAKES TODAY AND ALLOW SOUTHWEST WINDS TO INCREASE
SOMEWHAT TO THE 10-15 KNOT RANGE...WITH THE STRONGEST WINDS ON LAKE
ERIE. EXPECT CONDITIONS TO REMAIN BELOW SMALL CRAFT CRITERIA...BUT
WAVES MAY GET A LITTLE CHOPPY ON LAKE ERIE.
A RIDGE OF HIGH PRESSURE WILL NOSE INTO THE LOWER LAKES MONDAY WITH
RELATIVELY LIGHT WINDS. SOUTHWEST WINDS WILL PICK UP AGAIN TUESDAY
AHEAD OF A STRONGER COLD FRONT...ESPECIALLY ON LAKE ERIE WHERE
CONDITIONS MAY APPROACH SMALL CRAFT ADVISORY CRITERIA.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL
MARINE...APFFEL/JJR
AREA FORECAST DISCUSSION
NWS BUFFALO NY
331 AM EDT SUN JUL 15 2012
.SYNOPSIS...
A SOUTHWESTERLY FLOW WILL BRING INCREASINGLY HUMID AIR INTO THE REGION
TODAY ALONG WITH SOME SHOWERS AND THUNDERSTORMS. A FEW STORMS WILL
CONTAIN LOCALLY HEAVY RAINFALL...BUT ANY HEAVIER RAIN AMOUNTS WILL
BE SPOTTY. A RIDGE OF HIGH PRESSURE WILL BUILD INTO THE LOWER GREAT
LAKES MONDAY WITH MAINLY DRY CONDITIONS.
&&
.NEAR TERM /THROUGH TONIGHT/...
TODAY WILL BRING AN OPPORTUNITY FOR DROUGHT RELIEF...HOWEVER SHOWERS
AND THUNDERSTORMS WILL BE PATCHY IN NATURE...SO MANY COULD MISS OUT.
THERE APPEARS TO BE TWO FEATURES WHICH WILL KEY THIS ACTIVITY. THE
FIRST IS A MODEST 25 KT LOW LEVEL JET FOUND AT 925 MB...WHICH IS
KEYING THE ADVANCE OF LOW LEVEL MOISTURE. DEW POINTS HAVE RISEN TO
AROUND 70 ACROSS OHIO EARLY THIS MORNING...WITH MODEST SHOWER
ACTIVITY EXTENDING FROM SOUTHERN ONTARIO TO FAR SOUTHWESTERN NEW
YORK. THIS IS LIFTING TO THE NE...AND SHOULD SPREAD FURTHER INTO THE
CWA THROUGH MID-MORNING.
AS IS OFTEN THE CASE...MODEL GUIDANCE IS STRUGGLING A BIT WITH
CONVECTION...WITH A FAIR SPREAD OF QPF SOLUTIONS BETWEEN THE
NAM/RGEM/GFS/EUROPEAN/SREF. THE HRRR HAS ALSO BEEN INCONSISTENT RUN TO
RUN...AND GIVEN THIS SCENARIO WILL TEND TO WEIGHT RADAR TRENDS IN THE
NEAR TERM...AND A SREF WEIGHTED ENSEMBLE OF AVAILABLE GUIDANCE FROM
LATE MORNING ON. THIS SUGGESTS FAIRLY MODEST SHOWER ACTIVITY WILL
MOVE ACROSS THE REGION THROUGH MID TO LATE MORNING...WITH THE BEST
CHANCE FOR THIS SOUTH OF LAKE ONTARIO. EXPECT SHOWERS TO BE HIT AND
MISS.
THERE SEEMS TO BE A FAIR CONSENSUS THAT THE MOST SIGNIFICANT RAINS
WILL COME EARLY AFTERNOON. THIS MAKES SENSE GIVEN THE APPROACH OF A
SLOW MOVING UPPER LEVEL TROF AND THE CONTRIBUTION OF DAYTIME
HEATING. THIS WILL LIKELY BRING SHOWERS AND THUNDERSTORMS TO THE
SOUTHERN TIER AND INTO THE FINGER LAKES REGION...AND PERHAPS
ELSEWHERE THOUGH COVERAGE SHOULD BE A BIT MORE SPARSE. CONVECTION
WILL FORM ALONG ANY BOUNDARY IT CAN FIND...BUT HAVE SOME CONCERN
MUCH OF THE BUFFALO METRO AREA (AND WATERTOWN FOR THAT MATTER) WILL
MISS OUT IN A SOUTHWEST FLOW WHICH CAN TEND TO SHADOW THE REGION
FROM AFTERNOON CONVECTION.
AS HAS BEEN THE CASE THE PAST TWO DAYS...THE FLOW ALOFT WILL BE
FAIRLY LIGHT. HOWEVER...TODAY THE PRECIPITABLE WATER VALUES WILL BE
SIGNIFICANTLY GREATER...BETWEEN 1.75 INCHES AND 2.00 INCHES. IF IT
WERE NOT FOR THE VERY DRY CONDITIONS IN PLACE...THIS WOULD POSE A
GREATER FLOODING THREAT...BUT EVEN STILL THERE IS A REAL POTENTIAL
FOR FLOODING ALBEIT LOCALIZED. HAVE THE MOST CONCERN FOR THE
SOUTHERN TIER...WHERE TERRAIN CAN FUNNEL RUNOFF. DUE TO THE HIT OR
MISS NATURE OF CONVECTION...MEAN QPFS COULD BE A BIT MISLEADING.
WHILE BASIN-WIDE QPF FORECASTS RANGE FROM NEAR A HALF INCH EXPECTED
IN THE SOUTHERN TIER DOWN TO A TENTH OF AN INCH NORTH AND WEST OF
I-90...RAINFALL BY LOCATION SHOULD VARY SIGNIFICANTLY.
THE UPPER TROF WILL SLOWLY MOVE ACROSS THE REGION THIS EVENING...BUT
BY THIS TIME...DRIER AIR SHOULD BE IN PLACE IN THE BOUNDARY
LAYER...SO SHOWER AND THUNDERSTORMS SHOULD TAPER OFF AND/OR EXIT
EAST. THE WEAK FRONTAL BOUNDARY ASSOCIATED WITH THE TROF WILL NOT
ACTUALLY CROSS THE REGION TONIGHT. THIS WILL KEEP MOIST AIR IN
PLACE...AND DEPENDING ON RAINFALL TODAY COULD RESULT IN FOG TONIGHT.
TEMPERATURES WILL BE A BIT COOLER TODAY THAN THEY WERE
YESTERDAY...HOWEVER INCREASED MOISTURE WILL MAKE IT FEEL MORE MUGGY.
HIGHS SHOULD BE IN THE LOWER 80S NORTH OF THE THRU-WAY...BUT MAY
STAY IN THE UPPER 70S IN THE SOUTHERN TIER WHERE CLOUDS AND SHOWERS
SHOULD LIMIT TEMPERATURES A BIT. FOR TONIGHT...LOWS WILL RANGE FROM
THE LOWER 60S IN THE SOUTHERN TIER...TO AROUND 70 IN THE
BUFFALO/ROCHESTER METRO AREAS.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
DURING THE COURSE OF MONDAY...THE AXIS OF A WEAK UPPER LEVEL TROUGH
DRAPED FROM THE NEW ENGLAND COAST TO THE MID ATLANTIC STATES WILL
SLIDE OUT TO SEA...ALLOWING THE LEADING EDGE OF BROAD/FLAT UPPER
RIDGING TO EDGE NORTHEAST INTO THE LOWER LAKES. MEANWHILE AT THE
SURFACE...LINGERING WEAK TROUGHINESS ACROSS THE LOWER LAKES AT THE
START OF THE DAY WILL ALSO SLIDE EASTWARD...GIVING WAY TO MODEST LOW
LEVEL RIDGING DURING THE AFTERNOON.
GIVEN THESE DEVELOPMENTS...EXPECT THAT MONDAY SHOULD LARGELY BE
ANOTHER DRY AND HOT/HUMID DAY...WITH 850 MB TEMPS OF +16C/+17C AGAIN
SUPPORTING WIDESPREAD HIGHS IN THE UPPER 80S/LOWER 90S GIVEN WHAT
SHOULD BE A DECENT AMOUNT OF SUNSHINE. WHILE BOTH THE GFS AND ECMWF
BOTH SPIT OUT SOME LIGHT QPF ACROSS THE AREA PRIOR TO THE DEPARTURE
OF THE LOW LEVEL TROUGH...BELIEVE THAT THIS IS OVERDONE GIVEN ONLY
WEAK LINGERING FORCING AND FAIRLY WARM MID LEVEL TEMPS...WHICH
SHOULD HELP TO KEEP ANY PRECIP ISOLATED IN COVERAGE AT BEST. HAVE
THEREFORE KEPT POPS AT THE VERY LOW END OF THE SLIGHT CHANCE RANGE
OR BELOW ON MONDAY.
MONDAY NIGHT...BROAD/FLAT UPPER RIDGING WILL REMAIN INTACT ACROSS
MUCH OF THE AREA...WHILE A SLOW MOVING COLD FRONTAL BOUNDARY OVER
CENTRAL ONTARIO PROVINCE SAGS SOUTHWARD INTO THE UPPER LAKES AND
SOUTHERN ONTARIO. WHILE I CANNOT TOTALLY RULE OUT SOME ASSOCIATED
ISOLATED CONVECTION SNEAKING INTO THE SAINT LAWRENCE VALLEY TOWARD
DAYBREAK ON TUESDAY...IT DOES APPEAR THAT THE FRONT WILL REMAIN FAR
ENOUGH TO OUR NORTH AND THAT WE WILL REMAIN CAPPED ENOUGH FOR MAINLY
DRY WEATHER TO CONTINUE AREAWIDE. WITH NO AIRMASS CHANGE AND AN
INCREASING SOUTHWESTERLY LOW LEVEL FLOW EXPECTED WITH TIME IN
RESPONSE TO THE APPROACHING FRONT...EXPECT DOWNRIGHT SULTRY
TEMPERATURES WITH OVERNIGHT LOWS RANGING FROM THE MID AND UPPER 60S
ACROSS INTERIOR SECTIONS...TO THE LOWER 70S ACROSS THE LAKE PLAINS.
ON TUESDAY...THE AFOREMENTIONED FRONT WILL CONTINUE TO SLOWLY SAG
SOUTH TOWARD OUR REGION...WITH NOTABLE TIMING DIFFERENCES SEEN
AMONGST THE VARIOUS GUIDANCE PACKAGES. THE 00Z NAM IS AN EXTREMELY
FAST OUTLIER THAT BRINGS THE FRONT COMPLETELY THROUGH THE AREA BY
THE END OF THE DAY...WHICH SEEMS HIGHLY UNLIKELY GIVEN ITS
NEAR-PARALLEL ORIENTATION TO THE UPPER LEVEL FLOW...NOT TO MENTION
THE PROPENSITY FOR SUCH BOUNDARIES TO GET HUNG UP ACROSS THE LOWER
LAKES AT THIS TIME OF YEAR. FOR THIS REASON...HAVE COMPLETELY
DISREGARDED THIS SOLUTION. OF THE REMAINING GUIDANCE...THE GFS
REMAINS A BIT ON THE FASTER SIDE THOUGH NOT AS FAST AS ITS PREVIOUS
RUNS...BRINGING THE BOUNDARY INTO NORTHERN NEW YORK/LAKE ONTARIO BY
THE END OF THE DAY...WHICH IS CLOSE ENOUGH TO GENERATE SOME
CONVECTION ACROSS BOTH THE NORTH COUNTRY AND NIAGARA/ORLEANS
COUNTIES. MEANWHILE...THE VERY CONSISTENT ECMWF REMAINS A TOUCH
SLOWER THAN THE GFS AND ONLY BRINGS A RISK OF CONVECTION INTO THE
NORTH COUNTRY...WITH THE 00Z GEM GLOBAL A BIT SLOWER STILL. AT THIS
JUNCTURE...FEEL A COMPROMISE BETWEEN THE GFS/ECMWF REPRESENTS THE
MOST PLAUSIBLE SCENARIO...WHICH WOULD BRING AT LEAST A LOW TO MODEST
CHANCE OF CONVECTION TO LAKE ONTARIO AND THE NORTH COUNTRY BY LATE
IN THE DAY.
FURTHER TO THE SOUTH...CONDITIONS SHOULD REMAIN DRY THROUGH THE DAY
ON TUESDAY...THANKS TO BOTH GREATER DISTANCE FROM THE FRONT AND
STRONG MID LEVEL CAPPING...AS EVEN HOTTER AIR RIDES EAST ALONG THE
PERIPHERY OF THE MAIN UPPER LEVEL RIDGE. A CONSENSUS OF THE
GFS/GEM/ECMWF SUPPORTS 850 MB TEMPS RISING TO THE +20/+21C RANGE
AREAWIDE DURING THE COURSE OF TUESDAY...AND THIS COUPLED WITH GOOD
MIXING AND A DECENT AMOUNT OF SUN WILL LIKELY RESULT IN A REAL
SCORCHER OF A DAY SOUTH OF LAKE ONTARIO. AT THIS POINT...WIDESPREAD
HIGHS IN THE LOWER TO MID 90S APPEAR TO BE A SOLID BET...WITH UPPER
90S NOT AT ALL OUT OF THE QUESTION FOR THE NORMAL HOT SPOTS IN
INTERIOR PORTIONS OF OUR CWA. COUPLED WITH DEWPOINTS IN THE MID TO
UPPER 60S...SOME LOCATIONS SOUTH OF LAKE ONTARIO COULD SEE APPARENT
TEMPERATURES REACHING THE 100 DEGREE MARK TUESDAY AFTERNOON...WHICH
WOULD NECESSITATE THE ISSUANCE OF A HEAT ADVISORY. AS IT REMAINS FAR
TOO EARLY FOR THAT...FOR NOW WILL JUST MENTION THIS POTENTIAL IN THE
HWO. EAST OF LAKE ONTARIO...SOMEWHAT GREATER AMOUNTS OF CLOUD COVER
WILL LIKELY HELP KEEP TEMPS A LITTLE COOLER...THOUGH IT SHOULD STILL
BE UNCOMFORTABLY HOT EVEN THERE WITH HIGHS IN THE UPPER 80S TO LOWER
90S.
TUESDAY NIGHT AND WEDNESDAY...THE COLD FRONT WILL SLOWLY SAG SOUTH
ACROSS THE REGION...BRINGING A RISK OF CONVECTION TO THE ENTIRE
CWA...ALONG WITH THE POTENTIAL FOR LOCALLY HEAVY RAINFALL GIVEN
PRECIPITABLE WATER VALUES IN THE VICINITY OF AROUND 2 INCHES. AT
THIS JUNCTURE...THE TIMING OF THIS BOUNDARY REMAINS AN ISSUE WITH
THE GFS REMAINING THE FASTEST...THE CANADIAN THE SLOWEST...AND THE
ECMWF IN THE MIDDLE...WITH FROPA TIMES RANGING BETWEEN EARLY TO MID
WEDNESDAY MORNING AND WEDNESDAY AFTERNOON. GIVEN THAT THIS FRONT
APPEARS TO BE ANAFRONTAL WITH MOST OF ITS PRECIP FALLING BEHIND THE
ACTUAL SURFACE BOUNDARY...THIS MEANS THAT ANY ASSOCIATED CONVECTION
COULD END AS EARLY AS SOMETIME WEDNESDAY MORNING...OR AS LATE AS THE
END OF THE DAY WEDNESDAY.
GIVEN THE CONTINUED UNCERTAINTIES IN TIMING AND THE AFOREMENTIONED
NEAR-PARALLEL ORIENTATION OF THE FRONT TO THE UPPER FLOW...FEEL IT
IS BEST TO SLOW DOWN THE TIMING OF THIS FRONT AND ITS ASSOCIATED
CONVECTION A BIT FROM THE PREVIOUS FORECAST...FAVORING A COMPROMISE
SOLUTION ALONG THE LINES OF THE ECMWF. AS A RESULT...CHANCES FOR
CONVECTION WILL BE IN PLACE FROM TUESDAY NIGHT THROUGH WEDNESDAY
MORNING ACROSS THE ENTIRE AREA...BEFORE DIMINISHING FROM NORTH TO
SOUTH DURING THE COURSE OF WEDNESDAY AFTERNOON. TEMPERATURE-WISE...
EXPECT ANOTHER SULTRY NIGHT IN ADVANCE OF THE FRONT TUESDAY NIGHT
WITH LOWS AGAIN RANGING FROM THE UPPER 60S TO LOWER 70S...FOLLOWED
BY SOMEWHAT COOLER HIGHS IN THE UPPER 70S TO MID 80S ON WEDNESDAY
GIVEN THE PASSAGE OF THE FRONT AND ITS ASSOCIATED CLOUD COVER/PRECIP.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
SIMPLY PUT...SPRAWLING CANADIAN HIGH PRESSURE WILL BUILD SOUTHEAST
ACROSS THE GREAT LAKES AND NORTHEAST DURING THIS PERIOD...BRINGING A
RETURN TO DRY WEATHER ALONG WITH A COOLER AND NOTICEABLY LESS HUMID
AIRMASS.
IN TERMS OF ACTUAL TEMPERATURES...EXPECT DAILY HIGHS TO FALL BACK
INTO THE MID 70S TO LOWER 80S FOR BOTH THURSDAY AND FRIDAY...BEFORE
WARMING BACK INTO THE LOWER TO MID 80S ON SATURDAY AS WARMING
COMMENCES ALOFT. MEANWHILE...NIGHTTIME LOWS WILL RANGE IN THE MID
50S TO LOWER 60S ALL THREE NIGHTS. HUMIDITY LEVELS WILL ALSO BE MUCH
MORE COMFORTABLE...WITH DEWPOINTS REMAINING IN THE MID TO UPPER 50S
DURING THE BULK OF THE PERIOD.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
THE THREAT FOR SHOWERS AND THUNDERSTORMS WILL INCREASE FROM SW TO NE
BETWEEN 06Z AND 15Z AS A WEAK LOW LEVEL JET KEYS THE ADVANCE OF
MOIST AIR. RADAR SUGGESTS THESE STORMS WILL BE SCATTERED IN
NATURE...NOT IMPACTING ALL TAF SITES. THERE IS A MINIMAL CHANCE FOR
FOG AT BUF/IAG/ROC/ART...BUT AT JHW THERE APPEARS A GOOD CHANCE FOR
A SHOWER SHORTLY AFTER 06Z...WHICH MAY LEAD TO FOG AND LOW CLOUDS
IFR OR LOWER.
BEHIND THIS INITIAL AREA OF SHOWERS AND THUNDERSTORMS WILL BE
ANOTHER OPPORTUNITY FOR CONVECTION WITH AN APPROACHING SHORTWAVE
THIS AFTERNOON. LAKE SHADOWING WILL DIMINISH THE POTENTIAL AT
BUF/IAG/ART...THOUGH THE LAKES ARE WARM ENOUGH THAT THUNDERSTORMS
CANNOT COMPLETELY BE RULED OUT AT ANY TAF LOCATION. THIS SAID...THE
BEST CHANCE FOR THUNDERSTORMS WILL BE OUT AHEAD OF THIS SHORTWAVE AT
JHW/ROC EARLY THIS AFTERNOON.
EXPECT A GENERAL CLEARING TREND FROM WEST TO EAST LATE THIS
AFTERNOON AND EVENING. THIS SHOULD RESULT IN MAINLY VFR
CONDITIONS...BUT THERE WILL BE AN INCREASING CHANCE FOR FOG
OVERNIGHT. THE COMBINATION OF LIGHT WINDS AND LINGERING BOUNDARY
LAYER MOISTURE MAY RESULT IN FAIRLY WIDESPREAD IFR OR LOWER
CONDITIONS LATE TONIGHT...ESPECIALLY IF SKIES CLEAR OUT.
OUTLOOK...
MONDAY AND TUESDAY...MAINLY VFR.
TUESDAY NIGHT...AREAS OF MVFR IN SCATTERED -SHRA/-TSRA.
WEDNESDAY...BECOMING VFR.
THURSDAY...VFR.
&&
.MARINE...
HIGH PRESSURE WILL REMAIN ANCHORED ALONG THE MID ATLANTIC COAST
THROUGH EARLY NEXT WEEK. MEANWHILE A WEAK TROUGH WILL APPROACH THE
LOWER LAKES TODAY AND ALLOW SOUTHWEST WINDS TO INCREASE
SOMEWHAT TO THE 10-15 KNOT RANGE...WITH THE STRONGEST WINDS ON LAKE
ERIE. EXPECT CONDITIONS TO REMAIN BELOW SMALL CRAFT CRITERIA...BUT
WAVES MAY GET A LITTLE CHOPPY ON LAKE ERIE.
A RIDGE OF HIGH PRESSURE WILL NOSE INTO THE LOWER LAKES MONDAY WITH
RELATIVELY LIGHT WINDS. SOUTHWEST WINDS WILL PICK UP AGAIN TUESDAY
AHEAD OF A STRONGER COLD FRONT...ESPECIALLY ON LAKE ERIE WHERE
CONDITIONS MAY APPROACH SMALL CRAFT ADVISORY CRITERIA.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL
MARINE...APFFEL/JJR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
300 PM CDT SUN JUL 15 2012
.SHORT TERM...
THE MAIN CHALLENGES WILL BE CONVECTIVE CHANCES LATE THIS AFTERNOON
AND OVERNIGHT...ALONG WITH TEMPS AND RESULTANT HEAT INDICES
THROUGH MONDAY IN THE SOUTH. MODELS CONTINUE TO DIFFER IN REGARDS
TO WARM FRONTAL PLACEMENT AND CONVECTION...WITH THE GFS STILL TOO
FAR SOUTH WITH THE NAM PERHAPS TOO FAR NORTH. THE ECMWF REMAINS A
DECENT COMPROMISE ALTHOUGH IT IS MORE IN THE NORTHERLY NAM CAMP.
THE LATEST NEAR TERM HRRR AND OTHER MESOSCALE MODELS ARE ALSO IN
AGREEMENT WITH THE CAP HOLDING INTO THIS EVENT WITH A MORE
NORTHERLY MCS OVERNIGHT...SO WILL BASE POPS ON THIS SCENARIO.
FOR TONIGHT...EXPECT CONVECTION TO DEVELOP SOMEWHERE IN NC ND TO
THE WEST OF THE FORECAST AREA AROUND OR SHORTLY BEFORE 00Z. STORM
MOTION VECTORS AND INCREASE LLJ WILL LIKELY CAUSE THESE STORMS TO
TRACK NEAR THE CANADIAN BORDER THEN TURN INTO NE ND/NW MN
OVERNIGHT. THERE WILL BE AMPLE SHEAR/INSTABILITY FOR A FEW SEVERE
STORMS...AND GIVEN A VERY PRONOUNCED WARM FRONT AND HIGH
SHEAR...CAN/T RULE OUT A TORNADO EITHER IF DEWPOINTS CAN POOL
ENOUGH LOCALLY. IT STILL IS UNCERTAIN HOW CURRENT CAP WILL AFFECT
CONVECTION THOUGH...BUT POTENTIAL EXISTS FOR SEVERE STORMS SO WILL
MENTION OVERNIGHT. IT WILL BE VERY MILD OVERNIGHT...WITH THE
SOUTH REMAINING IN THE 70S.
FOR MON...THE FRONT WILL SAG INTO THE SOUTH BUT IT WILL REMAIN
VERY WARM HERE. HEAT INDICES WILL RISE TO AROUND 100...AND WE MAY
NEED SOME HEAT HEADLINES HERE. FOR NOW WILL HOLD ON HEADLINES WITH
UNCERTAINTY IN REGARDS TO CLOUD COVER/DEWPOINTS BUT SOMETHING TO
KEEP IN MIND FOR LATER SHIFTS. THERE WILL BE THE CHANCE FOR
SHOWERS OR STORMS BUT MOST AREAS WILL REMAIN DRY.
ON TUE/WED...EXPECTING A COUPLE OF DRY DAYS WITH TEMPS NEAR
NORMAL AND HIGH PRESSURE BUILDING IN. THERE COULD BE A THREAT FOR
SOME CONVECTION IN THE FAR SOUTH...BUT FEEL ITS NOT WORTH A
MENTION BUT SOMETHING TO KEEP IN MIND.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
GFS/ECMWF IN POOR AGREEMENT WEDNESDAY THROUGH NEXT WEEKEND...
BECOMING 180 DEGREES OUT OF PHASE ACROSS THE NORTHERN PLAINS BY
00 UTC SATURDAY WITH RESPECT TO THE 500 HPA HEIGHT PATTERN. DESPITE
ALLBLEND POPS OF 20 TO 30 PERCENT NEARLY EVERY PERIOD...WILL FOLLOW
PREVIOUS FORECAST CLOSELY TO MAINTAIN CONTINUITY. GIVEN RECENT
SYNOPTIC REGIME...PREFER THE HOTTER AND DRIER ECMWF SOLUTION. BEST
AGREEMENT BETWEEN GFS/ECMWF FOR PRECIPITATION IS WEDNESDAY NIGHT
INTO THURSDAY AS A WEAK SHORT-WAVE MAY MOVE THROUGH RIDGE ALOFT.
ALSO INCLUDED LOW POPS FRIDAY NIGHT INTO SATURDAY ON THE OFF-CHANCE
THE OVERLY AGGRESSIVE GFS VERIFIES WITH ANOTHER WAVE MOVING ALONG
THE CANADIAN BORDER. TEMPERATURES EXPECTED TO INCREASE SLIGHTLY EACH
DAY...WITH MANY LOCATIONS BACK IN THE 90S BY FRIDAY/SATURDAY.
OVERNIGHT LOWS MAY ALSO BE VERY WARM BY WEEK/S END...AT OR ABOVE 70
DEGREES.
&&
.AVIATION...
EXPECT VFR CONDITIONS THROUGH 18 UTC MONDAY. LATE THIS AFTERNOON AND
EVENING...SHOWERS AND THUNDERSTORMS WILL DEVELOP ALONG AND NORTH OF
A WARM FRONT STRETCHING ALONG THE HIGHWAY 2 CORRIDOR. WITH THE
EXCEPTION OF KDVL...THINK CONVECTION WILL REMAIN NORTH OF TAF
SITES...SO KEPT 18 UTC ISSUANCE DRY AT THIS TIME. WILL NEED TO WATCH
KGFK AND KTVF FOR POSSIBLE DEVELOPMENT FARTHER SOUTH. WINDS SOUTH OF
THE FRONT WILL CONTINUE FROM THE SOUTHEAST...GUSTING TO 25 KTS AT
TIMES. NORTH OF THE FRONT...WINDS WILL BE FROM THE EAST-NORTHEAST.
LATE TONIGHT...WINDS WILL SHIFT TO THE NORTHWEST AFTER SURFACE
TROUGH PASSAGE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
DK/ROGERS
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
333 PM CDT SUN JUL 15 2012
.DISCUSSION...
CURRENTLY...UPPER LEVEL RIDING IS PUSHING BACK INTO THE REGION
FROM THE EAST WHICH HAS PUSHED THE MOISTURE AXIS THAT CONTAINS
PWAT VALUES GREATER THAN 2 INCHES TO THE WESTERN HALF OF THE
MIDSOUTH. AN OUTFLOW BOUNDARY PUSHING NORTH INTO NW MS IS
PRODUCING SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WITH
ISOLATED TO SCATTERED CONVECTION ACROSS EASTERN ARKANSAS AND THE
MO BOOTHEEL. DRIER AIR WORKING INTO THE EASTERN HALF HAS SEVERELY
LIMITED AREAL COVERAGE EAST OF MEMPHIS FOR NOW. TEMPS ARE
GENERALLY IN THE MID AND UPPER 80S THOUGH A FEW READINGS ABOVE 90
CAN BE FOUND ACROSS NE MS AND SE PARTS OF WEST TN.
TONIGHT...BEST CHANCES FOR SHOWERS AND THUNDERSTORMS WILL CONTINUE
TO BE ACROSS THE WESTERN HALF OF THE MIDSOUTH THROUGH EARLY
EVENING WITH LESS COVERAGE TO THE EAST. SOME OF STORMS WILL
CONTAIN VERY HEAVY RAINFALL AND GUSTY WINDS. CONVECTION IS MAINLY
SURFACE HEATING BASED SO ACTIVITY WILL DISSIPATE QUICKLY THIS
EVENING AND THIS IS CONFIRMED NICELY BY THE LATEST HRRR RUN.
TEMPS WILL BE SIMILAR TO THE PAST SEVERAL NIGHT WITH LOWS IN THE
70 TO 75 DEGREE RANGE.
MONDAY THROUGH WEDNESDAY...UPPER RIDGE WILL BE OVER THE AREA AND
TEMPS WILL START TO HEAT UP INTO THE MID 90S BY TUESDAY AND
WEDNESDAY. SURFACE DEWPOINTS SHOULD REMAIN IN AT LEAST THE LOWER
70S WHICH MAY PRODUCE HEAT INDEX VALUES NEAR ADVISORY LEVELS BY
MIDWEEK. EVEN WITH THE UPPER RIDGE OVER THE AREA THE MID LEVEL
CAPPING WILL NOT BE STRONG ENOUGH TO COMPLETELY SHUT OFF
CONVECTION...THOUGH AREAL COVERAGE WILL BE LOWER AS PWAT VALUES
FALL. OVERNIGHT LOWS WILL BE TRENDING UP AS WELL.
THURSDAY THROUGH SUNDAY...UPPER RIDGE MAY WEAKEN SLIGHTLY AS AN
UPPER TROF MOVING THROUGH THE NORTHEAST/EASTERN GREAT LAKES SENDS
A BACK DOOR COLD FRONT INTO THE OHIO VALLEY. 12Z MODELS ARE NOT IN
VERY GOOD AGREEMENT ATTM. THE 12Z GFS LEANS TOWARD MORE UPPER
LEVEL RIDGING. MEANWHILE THE ECMWF DEVELOPS A CLOSED 500 MB LOW
OVER THE EASTERN OHIO VALLEY BY SUNDAY AFTERNOON. HAVE GENERALLY
GONE WITH A COMPROMISE BETWEEN THE COOLER/WETTER ECMWF AND THE
WARMER/DRIER GFS.
SJM
&&
.AVIATION...
18Z TAF CYCLE
CIGS AND VSBYS AT ALL TAF SITES HAVE BECOME VFR AND SHOULD REMAIN
SO THROUGH LATE THIS EVENING. PWATS REMAIN IN EXCESS OF 2 INCHES
AT ALL SURROUNDING 12Z SOUNDING LOCATIONS (KJAN...KLZK...KOHX)
WITH THE EXCEPTION BEING KBMX WHERE DRIER AIR HAS WORKED IN WITH
PWATS AROUND 1.45 INCHES DUE TO RIDGING ALOFT SPREADING WESTWARD.
PLAN TO CARRY VCTS AT ALL SITES FOR THIS AFTERNOON...BUT KEEP
TEMPOS AT ALL SITES EXCEPT KTUP WHERE DRIER AIRMASS MAY WORK IN.
THE HIGHEST CONVECTIVE POTENTIAL SHOULD REMAIN ALONG AND WEST OF
THE MISSISSIPPI RIVER TO INCLUDE KMEM AND KJBR. IN FACT...A
PROMINANT OUTFLOW BOUNDARY CURRENTLY OVER THE DELTA COUNTIES OF
NORTH CENTRAL MISSISSIPPI SHOULD CONTINUE TO PUSH NORTH TOWARDS
KMEM LATER THIS AFTERNOON AND MAY FOCUS CONVECTIVE ACTIVITY. TEMPO
AT KMEM MAY NEED TO BE EXTENDED BEYOND CURRENT EXPIRATION OF 15/22Z.
CONVECTION SHOULD WANE IN COVERAGE AND INTENSITY LATER THIS
EVENING WITH MOST LOCATIONS RAIN FREE AFTER 16/02Z.
LOWER CIGS SHOULD ONCE AGAIN OCCUR IN MOST LOCATIONS LATE TONIGHT
WITH AT LEAST REDUCTIONS TO MVFR. THERE MAY EVEN BE IFR CIGS AT
SOME LOCATIONS BUT CONFIDENCE NOT HIGH ENOUGH TO INCLUDE IN THE
LATEST TAF. THERE MAY ALSO BE SOME MVFR VSBYS IN PATCHY FOG.
LOW CLOUDS SHOULD MIX OUT BY LATER MONDAY MORNING WITH MOST
LOCATIONS BECOMING VFR NEAR THE END OF THE TAF FORECAST PERIOD.
CONVECTIVE POTENTIAL APPEARS LOWER TOMORROW AS THE PERSISTENT
UPPER TROUGH AXIS BEGINS TO SHIFT NORTHWEST AND UPPER RIDGING
BUILDS FROM THE SOUTHEAST.
JLH
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 75 93 76 95 / 20 30 10 20
MKL 71 93 72 94 / 20 30 10 20
JBR 73 93 74 95 / 20 20 10 20
TUP 73 94 74 94 / 20 20 10 30
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1235 PM CDT SUN JUL 15 2012
.AVIATION...
18Z TAFS THROUGH 20Z...CARRYING SHRA/TSRA FOR IAH AND CXO AND UTS. GENERALLY
WENT WITH VCSH ELSEWHERE BUT WILL HAVE TO WATCH FOR ADDITIONAL AFTERNOON
DEVELOPMENT OUT WEST WHERE CONVECTIVE TEMPERATURES ARE PROBABLY GOING
TO BE REACHED AGAIN (ALREADY SEEING REDEVELOPMENT IN/AROUND THE MATAGORDA
BAY AREA). VFR OVERNIGHT WITH LIGHT WINDS. LEANING TOWARD WETTER MODEL
SOLUTIONS FOR TOMORROW...SO INTRODUCED VCSH TOWARD THE COAST IN THE
MORNING AND VCTS FURTHER INLAND IN THE AFTER4NOON. GOOD COORDINATION
CALL WITH CWSU ZHU. 42
&&
.PREV DISCUSSION... /ISSUED 1013 AM CDT SUN JUL 15 2012/
DISCUSSION...
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ALONG THE
COAST MOVING NORTHEAST. THESE HAVE PRODUCED GUSTS OF 20-27 KTS
AND .77" OF RAIN AT GLS. 00Z/06Z MODELS DID A VERY POOR JOB IN
RESOLVING THESE STORMS AS WELL AS THE TEXAS TECH WRF/4KM NAT WRF
THOUGH THE RUC HAS DONE A MARGINAL JOB BUT WITH TOO MUCH
CONVECTION OVER THE GULF. WATER VAPOR HAS A SMALL CYCLONIC
CIRCULATION EMBEDDED IN THE MOIST AXIS JUST WEST OF MATAGORDA BAY.
AREA SOUNDINGS AND ACARS SOUNDINGS INDICATE THAT CONVECTIVE TEMPS
OF 82 TO 85 SHOULD BE SUFFICIENT FOR FURTHER DEVELOPMENT. HAVE
RAISED POPS IN THE SOUTH AND NORTHEAST FOR THE SHORT TERM TRENDS
THIS MORNING AND IN THE WEST FOR THE AFTERNOON AS VORT LIFTS NORTH
AND SPEED DIVERGENCE ALOFT HAS SOME ADDITIONAL LIFT. SHEAR AXIS
CONTINUES TO MOVE WEST AND THIS TO SHOULD HELP TO DESTABILIZE THE
WESTERN AREAS THIS AFTERNOON. STILL WORRIED ABOUT THE MOIST AXIS
ACROSS THE CENTRAL GULF AND OVER LA...WV CONTINUES TO CLEARLY
DEPICT THE WESTWARD PROGRESSION...COULD MAKE FOR A WET
MONDAY/TUESDAY. 45
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 73 92 74 93 74 / 20 30 20 30 20
HOUSTON (IAH) 74 91 75 92 76 / 20 30 10 30 20
GALVESTON (GLS) 81 90 81 90 81 / 20 30 20 30 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...45
AVIATION/MARINE...42
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1013 AM CDT SUN JUL 15 2012
.DISCUSSION...
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ALONG THE
COAST MOVING NORTHEAST. THESE HAVE PRODUCED GUSTS OF 20-27 KTS
AND .77" OF RAIN AT GLS. 00Z/06Z MODELS DID A VERY POOR JOB IN
RESOLVING THESE STORMS AS WELL AS THE TEXAS TECH WRF/4KM NAT WRF
THOUGH THE RUC HAS DONE A MARGINAL JOB BUT WITH TOO MUCH
CONVECTION OVER THE GULF. WATER VAPOR HAS A SMALL CYCLONIC
CIRCULATION EMBEDDED IN THE MOIST AXIS JUST WEST OF MATAGORDA BAY.
AREA SOUNDINGS AND ACARS SOUNDINGS INDICATE THAT CONVECTIVE TEMPS
OF 82 TO 85 SHOULD BE SUFFICIENT FOR FURTHER DEVELOPMENT. HAVE
RAISED POPS IN THE SOUTH AND NORTHEAST FOR THE SHORT TERM TRENDS
THIS MORNING AND IN THE WEST FOR THE AFTERNOON AS VORT LIFTS NORTH
AND SPEED DIVERGENCE ALOFT HAS SOME ADDITIONAL LIFT. SHEAR AXIS
CONTINUES TO MOVE WEST AND THIS TO SHOULD HELP TO DESTABILIZE THE
WESTERN AREAS THIS AFTERNOON. STILL WORRIED ABOUT THE MOIST AXIS
ACROSS THE CENTRAL GULF AND OVER LA...WV CONTINUES TO CLEARLY
DEPICT THE WESTWARD PROGRESSION...COULD MAKE FOR A WET
MONDAY/TUESDAY. 45
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 91 73 92 74 93 / 40 20 30 20 30
HOUSTON (IAH) 90 74 91 75 92 / 40 20 30 10 30
GALVESTON (GLS) 88 81 90 81 90 / 40 20 30 20 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...45
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1126 PM CDT SAT JUL 14 2012
.AVIATION...
NOT MUCH CHANGE FROM EARLIER THINKING. DO EXPECT SOME SCT
SHRA/TSTM REDEVELOPMENT LATER TONIGHT AND TOWARD MORNING. THOUGH
IT COULD BE ANYWHERE...MOST FAVORABLE LOCATIONS WOULD BE CLOSER TO
THE COAST AND UP TOWARD THE LAKE LIVINGSTON AREA CLOSER TO THE
UPPER CIRCULATION AND WHERE THE MORE FAVORABLE JET STRUCTURE WILL
BE. BEST COURSE OF ACTION WILL PROBABLY BE TO USE VCSH/VCTS`S AND
AMEND WHEN NECESSARY VERSUS CLUTTER TAFS WITH TEMPOS ETC. PRECIP
SHOULD EXPAND IN COVERAGE WITH MID/LATE MORNING HEATING AGAIN
SUNDAY. PRECIP SHOULD TAKER OFF FROM SOUTH TO NORTH DURING THE
LATE AFTN AND EARLY EVNG HOURS. 47
&&
.PREV DISCUSSION... /ISSUED 916 PM CDT SAT JUL 14 2012/
SHOWERS AND THUNDERSTORMS HAVE DIMINISHED QUICKLY YET AGAIN THIS
EVENING. UPDATED GRIDS FOR OBSERVED CONDITIONS IN THE VERY SHORT
RANGE. LOW LEVEL CIRCULATION APPARENT IN RAP13...PROFILER
WINDS...VWP WINDS AND SATELLITE LOOPS NEAR LONGVIEW (KGGG). AT
700MB PROFILER AND VWP WINDS SUGGEST TROUGH IS NEAR OR JUST OFF
THE SE TEXAS COAST AND CURVE BACK TO THE LOW. PWAT VALUES DO
APPEAR SLIGHTLY REDUCED FROM PREVIOUS EVENINGS WITH 00Z RAOB
VALUES RANGING FROM 1.8 TO NEAR 2 INCHES. BLENDED TPW IMAGERY FOR
THE CWA ARE AROUND 1.88 INCH SO STILL PLENTY MOISTURE RICH BUT A
TAD LOWER. SFC MESO BOUNDARIES GALORE THIS EVENING FROM CONVECTIVE
OUTFLOWS AND A LATE DEVELOPING SEA BREEZE. ONE BOUNDARY FROM NORTH
OF COLLEGE STATION TO CALDWELL ON SOUTHWESTWARD. ANOTHER OVER
COLORADO COUNTY..SEVERAL FROM CONVECTION OCCURRING NORTH OF CWA
AND OLD SEA BREEZE BOUNDARY FROM LIBERTY TO KHOU TO KBYY. HRRR AND
TX TECH WRF REFLECTIVITY FORECASTS ARE FOR GENERALLY QUIET NIGHT
WITH SOME DEVELOPMENT TOWARDS SUNRISE BUT FEEL WITH MULTITUDE OF
BOUNDARIES AND SLOWLY RETREATING TROUGH/LOW SOME ISOLATED TO
SCATTERED CONVECTION POSSIBLE A COUPLE OF HOURS PRIOR TO SUNRISE
MAINLY NEAR COAST AND NORTH OF A LINE FROM NORMANGEE TO LIVINGSTON
NEARER TO 850-700MB LOW. THIS IS HANDLED WELL IN OUR CURRENT
FORECAST LATER TONIGHT AND TOMORROW MORNING SO NO CHANGE
NECESSARY. STILL A POSSIBILITY FOR SOME ISOLATED HEAVY RAINS ON
SUNDAY SO MENTION OF LOCALLY HEAVY RAINS IN ZFP/GRIDS REMAINS A
GOOD IDEA. 04
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 73 88 73 92 74 / 20 50 20 30 20
HOUSTON (IAH) 74 89 74 91 75 / 20 50 30 40 20
GALVESTON (GLS) 80 88 82 90 81 / 30 50 40 40 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1041 PM CDT MON JUL 16 2012
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND TUESDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN AREA OF LOW
PRESSURE MOVING EAST OVER WESTERN LAKE SUPERIOR AND THE ARROWHEAD OF
MINNESOTA. WIDELY SCT SHOWERS AND ISOLATED THUNDERSTORMS HAVE
SLOWLY BEEN FIZZLING IN THE WARM ADVECTION CORRIDOR AHEAD OF THE LOW
OVER THE UPPER PENINSULA AND FAR NORTHWEST WISCONSIN. MID-LEVEL
CONVERGENT CLOUD BAND STILL EXISTS ALL THE WAY TO THE DAKOTAS AND
WILL LEAVE A MENTION OF AN ISOLATED SHOWER OVER FAR N-C WISCONSIN
THROUGH THE REST OF THE AFTERNOON. THE COLD FRONT EXTENDING WEST
OVER THE NORTHERN PLAINS REMAINS MOSTLY INACTIVE SO FAR. THE OTHER
MAIN STORY HAS BEEN THE HEAT TODAY. MOST PLACES IN THE HEAT
ADVISORY ARE IN THE MID TO UPPER 90S AND WITH A FEW MORE HOURS OF
HEATING...HAVE NO PLANS TO TAKE DOWN THE HEADLINES. AS THE COLD
FRONT SLOWLY DROPS SOUTH ACROSS THE REGION OVER THE NEXT 24
HOURS...THUNDERSTORMS CHANCES AND HEAT RELATED HEADLINES ARE THE
MAIN FORECAST CONCERNS.
TONIGHT...LOW PRESSURE OVER NORTHERN MINNESOTA WILL MOVE EAST OVER
LAKE SUPERIOR AND INTO SOUTHEAST ONTARIO. TRAILING COLD FRONT WILL
SLOWLY DROP SOUTH INTO NORTHERN WISCONSIN LATE THIS EVENING AND
ACROSS MUCH OF NORTHERN WISCONSIN AFTER MIDNIGHT. AHEAD OF
FRONT...BAND OF ISENTROPIC ASCENT AND WEAK CONVERGENCE ON THE 310K
SURFACE...AS NOTED BY THE MID-LEVEL CLOUD BAND OVER CENTRAL
MINNESOTA AND THE UPPER PENINSULA...WILL DROP SOUTH ACROSS NORTHERN
WISCONSIN THIS EVENING. WILL LEAVE A SLIGHT CHANCE OF SHOWERS TO
ACCOUNT FOR THIS POSSIBILITY. TEND TO THINK BETTER CHANCES OF
PRECIPITATION WILL OCCUR AFTER MIDNIGHT THOUGH. LATEST MODELS
INDICATED THAT THE SHORTWAVE OVER SOUTHERN SASKATCHEWAN WILL SHEAR
AS IT MOVES ACROSS SW ONTARIO LATE. RIGHT REAR QUAD OF A JET STREAK
WILL BECOME COINCIDENT WITH THE ELEVATED FRONT WHERE CAPES WILL
REACH OVER 1000 J/KG WHEN LIFTED FROM 750MB. ADDITIONALLY...WILL
ALSO HAVE MODERATE 850-700MB FGEN OVER NORTHERN WISCONSIN AS WELL.
THE LATEST HIRES-WRF SHOWS SHOWERS AND STORMS DEVELOPING OVER THE
NORTHERN PLAINS THIS EVENING...WHERE THE AFOREMENTIONED FORCING WILL
EXIST...BEFORE MOVING EAST WITH THE FORCING INTO NORTHERN WISCONSIN
LATE. AS A RESULT...WILL KEEP LOW END CHANCE WORDING OVER N-C
WISCONSIN LIKE THE PREVIOUS FORECAST SHOWED...BUT BRING THE SLIGHT
CHANCES OF SHOWERS FARTHER SOUTH THIS EVENING. SHOULD BE A WARM AND
MUGGY NIGHT WITH LOWS MAINLY IN THE 70S EXCEPT OVER FAR N-C
WISCONSIN.
TUESDAY...THE COLD FRONT WILL DROP SOUTH THROUGH THE DAY AND FINALLY
CLEAR THE SOUTHERN CWA BETWEEN 21-00Z. POTENTIAL FOR SHOWERS AND
STORMS WILL CARRY OVER FROM LATE TONIGHT INTO TUESDAY MORNING NORTH
OF ROUTE 29. IN THE AFTERNOON...SURFACE BASED CONVECTION BECOMES A
POSSIBILITY THOUGH IT DOES CONTINUE TO LOOK MARGINAL. DESPITE MOST
MODELS SPITTING OUT PRECIP TOMORROW...THERE WILL BE CAPPING TO
OVERCOME ESPECIALLY IF DEWPOINTS MIX OUT AGAIN. THINK MOISTURE
POOLING ALONG THE FRONT WILL HELP MITIGATE THAT ISSUE SOMEWHAT
TOMORROW SO WILL LEAVE A LOW CHANCE OF STORMS OVER THE SOUTHERN HALF
OF FORECAST AREA. GIVEN THE MAGNITUDE OF THE CAPES (GREATER THAN
2000 J/KG)...ISOLD SVR WILL BE POSSIBLE BUT THE BETTER WIND FIELDS
WILL EXIST BEHIND THE FRONT SO STILL NOT EXPECTING ANY WIDESPREAD
POTENTIAL. WITH THE FRONT NOT CLEARING CENTRAL WISCONSIN UNTIL LATE
IN THE DAY...TEMPS WILL SOAR ONCE AGAIN TOMORROW. MID TO UPPER 90S
LOOKS DOABLE BUT WITH MORE HUMIDITY THANKS TO THE MOISTURE POOLING
ALONG THE BOUNDARY. WILL EXTEND THE HEAT ADVISORY FOR THE HOT SPOTS OF
WAUPACA AND WAUSHARA COUNTIES...AND ALSO FOR WINNEBAGO. WINDS DO
TURN NE BEHIND THE FRONT...AND SHOULD BRING COOLER LAKE AIR INTO THE
NORTHERN FOX VALLEY AND LAKE SHORE COUNTIES BEFORE POINTS FARTHER
WEST.
.LONG TERM...THU NGT THRU NXT MON. THREE MAIN DETAILS TO DECIPHER
DURING THE EXTENDED PERIOD. FIRST...HOW LONG WL ANY PCPN HANG
AROUND TUE NGT AS THE CDFNT CONTS TO SLOWLY SAG SWD? SECOND...WHAT
ARE THE PCPN CHCS WED NGT/THU WITH THE PASSAGE OF A MID-LEVEL
SHORTWAVE? LASTLY...WHAT IS THE TIMING OF SHORTWAVE ENERGY
EJECTING EWD FROM THE PACIFIC NW UPR TROF FOR NXT WEEKEND? TEMPS
WL COOL TO AROUND NORMAL MID-WEEK...BUT BEGIN A SLOW UPTICK TOWARD
NXT WEEKEND WITH ANOTHER ROUND OF 90+ MAX TEMPS.
THE WEST TO EAST ORIENTATED CDFNT WL SLOWLY SINK TOWARD THE WI/IL
BORDER TUE NGT WITH FRONTOGENETICALLY FORCED POST-FRONTAL SHWRS/
TSTMS CNTRL/E-CNTRL WI THRU MUCH OF THE NGT. MAY EVEN NEED TO
CARRY A SLGT CHC POP OVER PARTS OF THE NORTH DEPENDING ON HOW FAR
SOUTH THE FNT GETS ON TUE. COOLER AIR FILTERING INTO THE REGION WL
ALLOW FOR TEMPS TO DROP INTO THE 50S NORTH...60 TO 65 DEGS
ELSEWHERE.
ENUF OF A NW FLOW ALOFT STILL IN PLACE ON WED TO SEND THE CDFNT
INTO NRN IL...BUT WL HAVE TO WATCH FOR LINGERING PCPN CHCS WED
MORNING OVER CNTRL/E-CNTRL WI. A WEAK AREA OF HI PRES IS THEN FCST
TO MOVE INTO NRN SECTIONS OF THE GREAT LKS AND BRING DRIER AIR
INTO NE WI ON E-NE WINDS BY WED AFTERNOON. TEMPS THROUGHOUT THE
FCST AREA WL BE MUCH CLOSER TO NORMAL FOR MID-JULY WITH MOST
LOCATIONS IN THE LWR TO MID 80S AND DEW PTS SETTLING INTO THE 50S.
SOME MODEL DISCREPANCY ARISES WED NGT AS THE ECMWF MAINTAINS A
FAVORABLE FRONTOGENETICAL FORCING SIGNAL ACROSS THE SRN HALF OF
WI...WHILE THE MAJORITY OF THE OTHER MDLS SUGGEST THAT THIS WL NOT
OCCUR. SINCE THE ECMWF HAS BEEN HINTING AT THIS FOR A WHILE NOW...
DO NOT WISH TO DISCOUNT IT...THUS HAVE ADDED A SMALL POP FOR CNTRL
WI AFTER MIDNGT. A WEAK/LITTLE MID-LEVEL SHORTWAVE IS FCST TO DROP
SE FROM THE UPR MS VALLEY TOWARD IL ON THU ALONG THE BAROCLINIC
ZONE AIDED BY THE RIGHT ENTRANCE REGION OF THE UPR JET. WHILE THE
MDLS GENERALLY AGREE ON THIS SCENARIO...PCPN CHCS LOOK MINIMAL
BASED ON A LACK OF SFC FEATURE AND INSTABILITY. ACTUAL MDL QPF
LOCATION ALSO VARY FROM NRN WI TO SRN WI TO NONE AT ALL...THUS
A LOW END POP WL SUFFICE WITH MOST AREAS AGAIN MISSING OUT ON MUCH
NEEDED RAINFALL.
THIS SHORTWAVE SHOULD HAVE PULLED FAR ENUF AWAY BY THU EVENING
SUCH THAT THE SLGT CHC POPS WERE REMOVED. OTHERWISE...MAIN STORY
FOR THU NGT INTO FRI WL BE THE RISING UPR HEIGHTS AS THE LARGE AND
DOMINANT UPR RDG OVER THE CNTRL CONUS EDGES A BIT FARTHER EAST.
LOOK FOR MAX TEMPS ON FRI TO START EDGING UPWARD WITH READINGS
RANGING FROM THE LWR 80S NORTH/LAKESHORE TO THE MID TO UPR 80S
CNTRL/E-CNTRL WI.
FCST CONTINUITY BREAKS DOWN NXT WEEKEND BETWEEN OPERATIONAL MDLS
AND ENSEMBLE MEANS. THE GFS/CANADIAN MDLS WANT TO QUICKLY RACE A
PIECE OF MID-LEVEL ENERGY EWD ACROSS EXTREME SRN CANADA BEFORE
TURNING SE INTO THE WRN GREAT LKS AS EARLY AS SAT. THE ECMWF IS
MUCH SLOWER (BY 18 HOURS). MEANWHILE...THE ECMWF AND GFS ENSEMBLE
MEANS ARE EVEN SLOWER YET. THIS PLACES PLENTY OF DOUBT AS TO
EXACTLY WHEN TO BRING THE NXT CHC OF PCPN TO THE FCST AREA.
BETWEEN THE KNOWN FAST BIAS OF THE GFS COUPLED WITH THE LOCATION
OF THE UPR RDG (POKING NE TOWARD WI)...FEEL THE SLOWER WAY IS THE
PROPER CALL. THEREFORE...HAVE KEPT SAT DRY AND VERY WARM WITH MAX
TEMPS RANGING FROM THE MID 80S TO LWR 90S.
WL NEED TO CARRY SOME SORT OF POP FOR SAT NGT INTO SUNDAY AS THE
MID-LEVEL ENERGY FINALLY DOES REACH THE WRN GREAT LKS ACCOMPANIED
BY A WEAK CDFNT. IT WOULD APPEAR THAT THE BETTER CHCS OF ACTUALLY
SEEING MEASURABLE PCPN WL AGAIN BE ACROSS THE NORTH WHERE THE CAP
IS WEAKER AND THE FNT APPROACHES AT PEAK HEATING. THE FNT REACHES
CNTRL/E-CNTRL WI SUNDAY NGT WHICH IS TYPICALLY NOT GOOD TIMING
WITH THE LOSS OF HEATING. IF THE FNT IS STILL CLOSE ENUF HEADED
INTO MON...THERE WOULD BE A POTENTIAL OF SEEING SHWRS/TSTMS
DEVELOP OVER SRN SECTIONS OF THE FCST AREA.
&&
.AVIATION...VFR WEATHER EXPECTED OVERNIGHT. LOW LEVEL WIND SHEAR
MA BE OF CONCERN FOR LIGHT AIRCRAFT AS LIGHT SOUTHWEST WINDS ARE
EXPECTED AT THE SURFACE WITH WEST SOUTHWEST WINDS AT 35 KNOTS
AROUND 1000 FT AGL.
A WEAK COLD FRONT WILL DROP SOUTH ACROSS THE REGION TUESDAY. IT
WILL BE FOLLOWED BY SCATTERED SHOWERS AND THUNDERSTORMS WITH MVFR
CIGS AND VSBYS. THERE MAY BE A PERIOD OF IFR CIGS IN FAR NORTHERN
WISCONSIN BETWEEN 12 AND 16Z IN THE MORNING.
RDM
&&
.MARINE...THE COOL FRONT CROSSING THE AREA TUE WL LIKELY HAVE A
SIG IMPACT ON BOATERS ON THE LAKE AND BAY. TIMING STILL A LITTLE
DIFFICULT TO GAUGE...BUT BALLPARKING IT WOULD HAVE A WIND SHIFT
OCCURRING BETWEEN 19-21Z. BUT EXPECT WLY WINDS OF 5-10 KTS AHEAD OF
THE FRONT TO ABRUPTLY SHIFT TO THE NE...WITH GUSTS OF 25-30 KTS FOR
A COUPLE HRS AFTER FROPA. THAT COULD ALSO RESULT IN SEAS QUICKLY
GETTING VERY CHOPPY. SHORT DURATION OF THE CONDITIONS AND THE ABRUPT
ONSET SUGGEST SITN PROBABLY BEST HANDLED WITH MARINE WX STATEMENT
RATHER THAN A SMALL CRAFT ADVISORY. BUT ADDED MENTION OF CONDITIONS
INTO HWO TO GIVE BOATERS A HEADS-UP ON THE SITN IF THEY ARE PLANNING
TO GO OUT ON THE LAKE OR BAY TOMORROW.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 7 PM CDT TUESDAY FOR WIZ037-045-048.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
704 PM CDT MON JUL 16 2012
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND TUESDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN AREA OF LOW
PRESSURE MOVING EAST OVER WESTERN LAKE SUPERIOR AND THE ARROWHEAD OF
MINNESOTA. WIDELY SCT SHOWERS AND ISOLATED THUNDERSTORMS HAVE
SLOWLY BEEN FIZZLING IN THE WARM ADVECTION CORRIDOR AHEAD OF THE LOW
OVER THE UPPER PENINSULA AND FAR NORTHWEST WISCONSIN. MID-LEVEL
CONVERGENT CLOUD BAND STILL EXISTS ALL THE WAY TO THE DAKOTAS AND
WILL LEAVE A MENTION OF AN ISOLATED SHOWER OVER FAR N-C WISCONSIN
THROUGH THE REST OF THE AFTERNOON. THE COLD FRONT EXTENDING WEST
OVER THE NORTHERN PLAINS REMAINS MOSTLY INACTIVE SO FAR. THE OTHER
MAIN STORY HAS BEEN THE HEAT TODAY. MOST PLACES IN THE HEAT
ADVISORY ARE IN THE MID TO UPPER 90S AND WITH A FEW MORE HOURS OF
HEATING...HAVE NO PLANS TO TAKE DOWN THE HEADLINES. AS THE COLD
FRONT SLOWLY DROPS SOUTH ACROSS THE REGION OVER THE NEXT 24
HOURS...THUNDERSTORMS CHANCES AND HEAT RELATED HEADLINES ARE THE
MAIN FORECAST CONCERNS.
TONIGHT...LOW PRESSURE OVER NORTHERN MINNESOTA WILL MOVE EAST OVER
LAKE SUPERIOR AND INTO SOUTHEAST ONTARIO. TRAILING COLD FRONT WILL
SLOWLY DROP SOUTH INTO NORTHERN WISCONSIN LATE THIS EVENING AND
ACROSS MUCH OF NORTHERN WISCONSIN AFTER MIDNIGHT. AHEAD OF
FRONT...BAND OF ISENTROPIC ASCENT AND WEAK CONVERGENCE ON THE 310K
SURFACE...AS NOTED BY THE MID-LEVEL CLOUD BAND OVER CENTRAL
MINNESOTA AND THE UPPER PENINSULA...WILL DROP SOUTH ACROSS NORTHERN
WISCONSIN THIS EVENING. WILL LEAVE A SLIGHT CHANCE OF SHOWERS TO
ACCOUNT FOR THIS POSSIBILITY. TEND TO THINK BETTER CHANCES OF
PRECIPITATION WILL OCCUR AFTER MIDNIGHT THOUGH. LATEST MODELS
INDICATED THAT THE SHORTWAVE OVER SOUTHERN SASKATCHEWAN WILL SHEAR
AS IT MOVES ACROSS SW ONTARIO LATE. RIGHT REAR QUAD OF A JET STREAK
WILL BECOME COINCIDENT WITH THE ELEVATED FRONT WHERE CAPES WILL
REACH OVER 1000 J/KG WHEN LIFTED FROM 750MB. ADDITIONALLY...WILL
ALSO HAVE MODERATE 850-700MB FGEN OVER NORTHERN WISCONSIN AS WELL.
THE LATEST HIRES-WRF SHOWS SHOWERS AND STORMS DEVELOPING OVER THE
NORTHERN PLAINS THIS EVENING...WHERE THE AFOREMENTIONED FORCING WILL
EXIST...BEFORE MOVING EAST WITH THE FORCING INTO NORTHERN WISCONSIN
LATE. AS A RESULT...WILL KEEP LOW END CHANCE WORDING OVER N-C
WISCONSIN LIKE THE PREVIOUS FORECAST SHOWED...BUT BRING THE SLIGHT
CHANCES OF SHOWERS FARTHER SOUTH THIS EVENING. SHOULD BE A WARM AND
MUGGY NIGHT WITH LOWS MAINLY IN THE 70S EXCEPT OVER FAR N-C
WISCONSIN.
TUESDAY...THE COLD FRONT WILL DROP SOUTH THROUGH THE DAY AND FINALLY
CLEAR THE SOUTHERN CWA BETWEEN 21-00Z. POTENTIAL FOR SHOWERS AND
STORMS WILL CARRY OVER FROM LATE TONIGHT INTO TUESDAY MORNING NORTH
OF ROUTE 29. IN THE AFTERNOON...SURFACE BASED CONVECTION BECOMES A
POSSIBILITY THOUGH IT DOES CONTINUE TO LOOK MARGINAL. DESPITE MOST
MODELS SPITTING OUT PRECIP TOMORROW...THERE WILL BE CAPPING TO
OVERCOME ESPECIALLY IF DEWPOINTS MIX OUT AGAIN. THINK MOISTURE
POOLING ALONG THE FRONT WILL HELP MITIGATE THAT ISSUE SOMEWHAT
TOMORROW SO WILL LEAVE A LOW CHANCE OF STORMS OVER THE SOUTHERN HALF
OF FORECAST AREA. GIVEN THE MAGNITUDE OF THE CAPES (GREATER THAN
2000 J/KG)...ISOLD SVR WILL BE POSSIBLE BUT THE BETTER WIND FIELDS
WILL EXIST BEHIND THE FRONT SO STILL NOT EXPECTING ANY WIDESPREAD
POTENTIAL. WITH THE FRONT NOT CLEARING CENTRAL WISCONSIN UNTIL LATE
IN THE DAY...TEMPS WILL SOAR ONCE AGAIN TOMORROW. MID TO UPPER 90S
LOOKS DOABLE BUT WITH MORE HUMIDITY THANKS TO THE MOISTURE POOLING
ALONG THE BOUNDARY. WILL EXTEND THE HEAT ADVISORY FOR THE HOT SPOTS OF
WAUPACA AND WAUSHARA COUNTIES...AND ALSO FOR WINNEBAGO. WINDS DO
TURN NE BEHIND THE FRONT...AND SHOULD BRING COOLER LAKE AIR INTO THE
NORTHERN FOX VALLEY AND LAKE SHORE COUNTIES BEFORE POINTS FARTHER
WEST.
.LONG TERM...THU NGT THRU NXT MON. THREE MAIN DETAILS TO DECIPHER
DURING THE EXTENDED PERIOD. FIRST...HOW LONG WL ANY PCPN HANG
AROUND TUE NGT AS THE CDFNT CONTS TO SLOWLY SAG SWD? SECOND...WHAT
ARE THE PCPN CHCS WED NGT/THU WITH THE PASSAGE OF A MID-LEVEL
SHORTWAVE? LASTLY...WHAT IS THE TIMING OF SHORTWAVE ENERGY
EJECTING EWD FROM THE PACIFIC NW UPR TROF FOR NXT WEEKEND? TEMPS
WL COOL TO AROUND NORMAL MID-WEEK...BUT BEGIN A SLOW UPTICK TOWARD
NXT WEEKEND WITH ANOTHER ROUND OF 90+ MAX TEMPS.
THE WEST TO EAST ORIENTATED CDFNT WL SLOWLY SINK TOWARD THE WI/IL
BORDER TUE NGT WITH FRONTOGENETICALLY FORCED POST-FRONTAL SHWRS/
TSTMS CNTRL/E-CNTRL WI THRU MUCH OF THE NGT. MAY EVEN NEED TO
CARRY A SLGT CHC POP OVER PARTS OF THE NORTH DEPENDING ON HOW FAR
SOUTH THE FNT GETS ON TUE. COOLER AIR FILTERING INTO THE REGION WL
ALLOW FOR TEMPS TO DROP INTO THE 50S NORTH...60 TO 65 DEGS
ELSEWHERE.
ENUF OF A NW FLOW ALOFT STILL IN PLACE ON WED TO SEND THE CDFNT
INTO NRN IL...BUT WL HAVE TO WATCH FOR LINGERING PCPN CHCS WED
MORNING OVER CNTRL/E-CNTRL WI. A WEAK AREA OF HI PRES IS THEN FCST
TO MOVE INTO NRN SECTIONS OF THE GREAT LKS AND BRING DRIER AIR
INTO NE WI ON E-NE WINDS BY WED AFTERNOON. TEMPS THROUGHOUT THE
FCST AREA WL BE MUCH CLOSER TO NORMAL FOR MID-JULY WITH MOST
LOCATIONS IN THE LWR TO MID 80S AND DEW PTS SETTLING INTO THE 50S.
SOME MODEL DISCREPANCY ARISES WED NGT AS THE ECMWF MAINTAINS A
FAVORABLE FRONTOGENETICAL FORCING SIGNAL ACROSS THE SRN HALF OF
WI...WHILE THE MAJORITY OF THE OTHER MDLS SUGGEST THAT THIS WL NOT
OCCUR. SINCE THE ECMWF HAS BEEN HINTING AT THIS FOR A WHILE NOW...
DO NOT WISH TO DISCOUNT IT...THUS HAVE ADDED A SMALL POP FOR CNTRL
WI AFTER MIDNGT. A WEAK/LITTLE MID-LEVEL SHORTWAVE IS FCST TO DROP
SE FROM THE UPR MS VALLEY TOWARD IL ON THU ALONG THE BAROCLINIC
ZONE AIDED BY THE RIGHT ENTRANCE REGION OF THE UPR JET. WHILE THE
MDLS GENERALLY AGREE ON THIS SCENARIO...PCPN CHCS LOOK MINIMAL
BASED ON A LACK OF SFC FEATURE AND INSTABILITY. ACTUAL MDL QPF
LOCATION ALSO VARY FROM NRN WI TO SRN WI TO NONE AT ALL...THUS
A LOW END POP WL SUFFICE WITH MOST AREAS AGAIN MISSING OUT ON MUCH
NEEDED RAINFALL.
THIS SHORTWAVE SHOULD HAVE PULLED FAR ENUF AWAY BY THU EVENING
SUCH THAT THE SLGT CHC POPS WERE REMOVED. OTHERWISE...MAIN STORY
FOR THU NGT INTO FRI WL BE THE RISING UPR HEIGHTS AS THE LARGE AND
DOMINANT UPR RDG OVER THE CNTRL CONUS EDGES A BIT FARTHER EAST.
LOOK FOR MAX TEMPS ON FRI TO START EDGING UPWARD WITH READINGS
RANGING FROM THE LWR 80S NORTH/LAKESHORE TO THE MID TO UPR 80S
CNTRL/E-CNTRL WI.
FCST CONTINUITY BREAKS DOWN NXT WEEKEND BETWEEN OPERATIONAL MDLS
AND ENSEMBLE MEANS. THE GFS/CANADIAN MDLS WANT TO QUICKLY RACE A
PIECE OF MID-LEVEL ENERGY EWD ACROSS EXTREME SRN CANADA BEFORE
TURNING SE INTO THE WRN GREAT LKS AS EARLY AS SAT. THE ECMWF IS
MUCH SLOWER (BY 18 HOURS). MEANWHILE...THE ECMWF AND GFS ENSEMBLE
MEANS ARE EVEN SLOWER YET. THIS PLACES PLENTY OF DOUBT AS TO
EXACTLY WHEN TO BRING THE NXT CHC OF PCPN TO THE FCST AREA.
BETWEEN THE KNOWN FAST BIAS OF THE GFS COUPLED WITH THE LOCATION
OF THE UPR RDG (POKING NE TOWARD WI)...FEEL THE SLOWER WAY IS THE
PROPER CALL. THEREFORE...HAVE KEPT SAT DRY AND VERY WARM WITH MAX
TEMPS RANGING FROM THE MID 80S TO LWR 90S.
WL NEED TO CARRY SOME SORT OF POP FOR SAT NGT INTO SUNDAY AS THE
MID-LEVEL ENERGY FINALLY DOES REACH THE WRN GREAT LKS ACCOMPANIED
BY A WEAK CDFNT. IT WOULD APPEAR THAT THE BETTER CHCS OF ACTUALLY
SEEING MEASURABLE PCPN WL AGAIN BE ACROSS THE NORTH WHERE THE CAP
IS WEAKER AND THE FNT APPROACHES AT PEAK HEATING. THE FNT REACHES
CNTRL/E-CNTRL WI SUNDAY NGT WHICH IS TYPICALLY NOT GOOD TIMING
WITH THE LOSS OF HEATING. IF THE FNT IS STILL CLOSE ENUF HEADED
INTO MON...THERE WOULD BE A POTENTIAL OF SEEING SHWRS/TSTMS
DEVELOP OVER SRN SECTIONS OF THE FCST AREA.
&&
.AVIATION...VFR WEATHER EXPECTED OVERNIGHT. LOW LEVEL WIND SHEAR
MA BE OF CONCERN FOR LIGHT AIRCRAFT IN EASTERN WISCONSIN AS LIGHT
SOUTHWEST WINDS ARE EXPECTED AT THE SURFACE WITH WEST SOUTHWEST
WINDS AT 35 KNOTS AROUND 1000 FT AGL.
A WEAK COLD FRONT WILL DROP SOUTH ACROSS THE REGION TUESDAY. IT
WILL BE FOLLOWED BY SCATTERED SHOWERS AND THUNDERSTORMS WITH MVFR
CIGS AND VSBYS.
RDM
&&
.MARINE...THE COOL FRONT CROSSING THE AREA TUE WL LIKELY HAVE A
SIG IMPACT ON BOATERS ON THE LAKE AND BAY. TIMING STILL A LITTLE
DIFFICULT TO GAUGE...BUT BALLPARKING IT WOULD HAVE A WIND SHIFT
OCCURRING BETWEEN 19-21Z. BUT EXPECT WLY WINDS OF 5-10 KTS AHEAD OF
THE FRONT TO ABRUPTLY SHIFT TO THE NE...WITH GUSTS OF 25-30 KTS FOR
A COUPLE HRS AFTER FROPA. THAT COULD ALSO RESULT IN SEAS QUICKLY
GETTING VERY CHOPPY. SHORT DURATION OF THE CONDITIONS AND THE ABRUPT
ONSET SUGGEST SITN PROBABLY BEST HANDLED WITH MARINE WX STATEMENT
RATHER THAN A SMALL CRAFT ADVISORY. BUT ADDED MENTION OF CONDITIONS
INTO HWO TO GIVE BOATERS A HEADS-UP ON THE SITN IF THEY ARE PLANNING
TO GO OUT ON THE LAKE OR BAY TOMORROW.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 7 PM CDT TUESDAY FOR WIZ037-045-048.
HEAT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR WIZ020-021-030-031-
035-036-038>040-049-050-073-074.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
236 PM CDT SUN JUL 15 2012
.SHORT TERM...TONIGHT AND MONDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE
CENTERED ON THE MONTANA-NORTH DAKOTA BORDER AND ITS ASSOCIATED WARM
FRONT EXTENDING ACROSS THE DAKOTAS. YESTERDAYS UPPER TROUGH HAS
MOVED TO THE EASTERN GREAT LAKES. WISCONSIN LIES BETWEEN THESE TWO
FEATURES IN A REGION OF BUILDING HEIGHTS ALOFT. DIURNAL CU HAS
POPPED OVER CENTRAL AND NORTH-CENTRAL WISCONSIN AND AREA RADARS HAVE
DETECTED A SOLE SPRINKLE THAT DEVELOPED EARLIER OVER THE
PORTAGE/WAUPACA BORDER. THE CU LOOKS RATHER FEISTY SO WILL ADD AN
ISOLATED SPRINKLE MENTION FOR THE REST OF THE AFTERNOON. AS THE MID-LEVEL
RIDGE BUILDS INTO OUR AREA...THE MAIN FORECAST CONCERNS INCLUDE
CLOUDS AND TEMPS INCLUDING HEAT HEADLINES OVER THE NEXT 24 HOURS.
TONIGHT...LOW PRESSURE WILL MOVE NE OVER THE NORTHERN PLAINS AND
HIGH PRESSURE WILL REMAIN CENTERED OVER THE SE CONUS. UPSTREAM
MID-DECK AND CIRRUS WILL LIKELY MAKE IT AT LEAST OVER THE NORTHERN
HALF OF THE FORECAST AREA TONIGHT AND LIGHT AND VARIABLE WINDS AT
THE SURFACE WILL PICK UP LATE. THESE CONDITIONS POINT TOWARDS
A WARMER NIGHT AND WILL GO WITH LOWS RANGING THROUGH THE 60S.
MONDAY...UPSTREAM LOW PRESSURE WILL MOVE EAST OVER NORTHERN
MINNESOTA AND WESTERN LAKE SUPERIOR. AS THIS OCCURS...A COLD FRONT
WILL SAG INTO NORTHWEST WISCONSIN LATE IN THE DAY...BUT AIRMASS
AHEAD OF THE FRONT IS PRETTY DRY...SO THINKING THERE IS SLIM CHANCES
OF A COOLING THUNDERSTORM. WILL LEAVE A SLIGHT CHANCE OVER FAR
NORTHERN VILAS IN CASE A ROGUE STORM DECIDES TO MAKE A RUN TOWARDS
THE NORTHERN TIP OF THE COUNTY. OTHERWISE...THE HEAT WILL BE THE
MAIN STORY TOMORROW. THE LATEST GUIDANCE SHOWS 850MB TEMPS IN THE
24-25C RANGE WHICH WOULD PUT HIGHS NEAR 100F. A TIGHTENING PRESSURE
GRADIENT WILL SUPPORT GOOD MIXING GREATER THAN 800MB...AND HELP TO
MIX OUT DEWPOINTS INTO THE LOW TO MID 60S. BUT THE GOOD MIXING ALSO
SUPPORTS GOING ON THE WARM SIDE OF GUIDANCE...WHICH PLACES HIGHS IN
THE MID TO UPPER 90S OVER CENTRAL AND EAST-CENTRAL WISCONSIN...AND
LOW TO MID 90S FARTHER NORTH. SOME 100S WILL LIKELY BE REACHED IN
THE HOT SPOTS AROUND WAUPACA AND WAUSHARA. ONLY CONCERN WITH TEMPS
IS THE MID AND HIGH LEVEL MOISTURE UPSTREAM...THOUGH ITS TOUGH TO
GAUGE HOW THICK IT WILL BE TOMORROW. BECAUSE DEWPOINTS WILL LIKELY
BE MIXING OUT...THINK HEAT INDICES MAY STRUGGLE TO REACH ADVISORY CRITERIA
OVER CENTRAL WISCONSIN. NONETHELESS...NO POINT IN CANCELLING
HEADLINES AT THIS POINT AS POTENTIAL WILL STILL BE THERE AND IT WILL
BE VERY HOT.
.LONG TERM...MONDAY NIGHT THROUGH NEXT SUNDAY.
CONTINUE TO DEAL WITH FLUCTUATIONS IN POSITION/STRENGTH OF STRONG
CENTRAL U.S. RIDGE WITH SYSTEMS EJECTING OUT OF WESTERN TROF THROUGH
CANADA. TEMPERATURES EXPECTED TO START OUT WARM...THEN RETURN TO
NEAR NORMAL LEVELS BEFORE HEATING UP AGAIN ON THE WEEKEND.
INITIALLY WILL BE DEALING WITH COOL FRONT MOVING INTO/THROUGH CWA
MONDAY NIGHT AND TUESDAY. MAIN FORCING WITH UPPER JET REMAINS OVER
THE NORTH...PULLS OUT TUE NIGHT. SOME INSTABILITY...THOUGH
LIMITED. NAM STRONGER WITH SURFACE LOW...FASTER WITH FRONT
PASSING...AND SHOWS DRY FRONTAL PASSAGE. EC ON SLOWER END OF
GUIDANCE WITH SYSTEM AND FOR PAST TWO RUNS SUGGESTS MCS/S MAY MOVE ALONG
FRONT TUE NIGHT/WED OVER SOUTHERN HALF OF STATE. NOT SEEING ANY SIG
FORCING FOR SCENARIO...EXCEPT FOR SOME RELATIVELY WEAK WAA OVER
MN/SD. FEW TEMPS/HEAT INDICES REACH ADVISORY LEVELS TUE AFTN OVER
THE SOUTH...BUT WILL NOT EXTEND CURRENT ADVISORY GIVEN CLOUD/PCPN
CONCERNS. CWA REMAINS ON EDGE OF SEE TEXT BY SPC FOR MONDAY NIGHT
INTO TUE NIGHT. SHEAR IS LIMITED...THOUGH COULD SEE SOME GUSTY
WINDS AND MARGINAL HAIL WITH SOME TO THE STORMS IF THEY DEVELOP.
FRONT WILL SAG SOUTH INTO NORTHERN ILLINOIS ON WEDNESDAY WITH DRY
CANADIAN HIGH PRESSURE MOVING IN FOR WED-FRI PERIOD.
SPREAD SEEN IN ENSEMBLES FOR THE WEEKEND...WITH RIDGE
POSITION/STRENGTH...THOUGH MEANS SUGGEST GOING ON THE WARM
SIDE.
&&
.AVIATION...FOR 12Z TAF ISSUANCE. AFTER FG BURNS OFF EARLY TDA...
VFR CONDITIONS EXPECTED. SOME FG POSSIBLE AGAIN TNGT...BUT IT WL
BE MUCH MORE PATCHY AND PROBABLY NOT OF A CONSEQUENCE TO AVIATION
INTERESTS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM NOON TO 9 PM CDT MONDAY FOR WIZ020-021-030-
031-035>040-045-048>050-073-074.
&&
$$
MPC/TE
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
355 AM EDT TUE JUL 17 2012
.SYNOPSIS...
07Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A VERY SUMMER-LIKE UPPER
LEVEL PATTERN IN PLACE OVER THE CENTRAL AND EASTERN CONUS. A FAST
NORTHERN STREAM FLOW IS BEGIN HELD WELL TO THE NORTH ACROSS SOUTHERN
CANADA BY A LARGE AND DOMINANT UPPER LEVEL RIDGE ALIGNED OVER THE MS
VALLEY. ANOTHER LARGE AREA OF UPPER LEVEL RIDGING IS CENTERED TO THE
NORTHEAST OF THE BAHAMAS...AND THIS FEATURE WILL BECOME THE DOMINANT
PLAYER IN OUR WEATHER FOR THE SECOND HALF OF THE WEEK. IN BETWEEN
THESE FEATURES...WE STILL FIND A TUTT (TROPICAL UPPER TROPOSPHERIC
TROUGH) CELL ROTATING SLOWLY WESTWARD ACROSS NORTHERN FLORIDA. THE
TUTT IS CURRENTLY CENTERED JUST TO THE WEST OF JACKSONVILLE AND WILL
ONLY VERY SLOWLY MIGRATE WESTWARD TOWARD THE SUWANNEE RIVER VALLEY
THROUGH THE DAY. SYNOPTIC SUPPORT ASSOCIATED WITH THIS TUTT CELL
COMBINED WITH THE LEADING EDGE OF AN ASSOCIATED RELATIVELY COLD
MID-LEVEL POCKET OF AIR HAS BEEN FORCING AN AXIS OF CONVECTION EARLY
THIS MORNING FROM APALACHEE BAY SE INTO THE TAMPA BAY AREA. AS WE
HEAD TOWARD DAWN...THE MAJORITY OF THE CONVECTION SHOULD SHIFT TO
THE COASTAL WATERS...HOWEVER DUE TO THE UPPER SUPPORT...CAN NOT RULE
OUT SHOWERS FOR THE COASTAL LAND ZONES.
AT THE SURFACE...SUBTROPICAL RIDGE AXIS IS ALIGNED OVER THE SOUTHERN
HALF OF FL PENINSULA THIS MORNING...AND THIS GENERAL POSITION IS
EXPECTED TO HOLD THROUGH THE SHORT TERM FORECAST PERIOD.
&&
.SHORT TERM (TODAY THROUGH THURSDAY)...
TODAY...TUTT CELL WILL CONTINUE TO INFLUENCE MAINLY THE CENTRAL
AND NORTHERN PORTIONS OF THE FORECAST AREA WITH SOME SYNOPTIC LIFT
AND ENHANCED INSTABILITY FROM ITS ASSOCIATED COOL POOL. THIS
INFLUENCE WILL BE FELT MOSTLY IN THE POTENTIAL FOR A FEW STRONGER
STORMS WITH SMALL HAIL AND FREQUENT LIGHTNING. SOUTH OF THE I-4
CORRIDOR...WHILE THE POTENTIAL FOR STRONGER STORMS WILL BE LESS...A
MOIST ATMOSPHERE AND DEVELOPING SEA-BREEZES WILL STILL ALLOW FOR A
GOOD COVERAGE OF DIURNAL CONVECTION. IN FACT...THE GFS IS SHOWING PW
VALUES REMAINING ABOVE 2" FOR THE SOUTHERN ZONES WHICH MAY LEAD TO
SOME HEAVY RAINFALL POTENTIAL. WE SAW THIS ON MONDAY OVER HIGHLANDS
COUNTY AND SIMILAR ATMOSPHERIC CONDITIONS WILL AGAIN LEAD TO THIS
LOCALIZED THREAT.
TONIGHT...TUTT CELL WILL BEGIN TO WEAKEN AND LIFT OUT TO THE NORTH.
LINGERING SCATTERED STORMS OVER THE INTERIOR SHOULD BE DIMINISHING
DURING THE LATE EVENING HOURS. AFTER MIDNIGHT EXPECT A SCATTERING OF
NOCTURNAL SHOWERS/STORMS TO DEVELOP OVER THE COASTAL WATERS. LOW
LEVEL FLOW WILL FAVOR THE BEST CHANCES FOR THESE STORMS TO MIGRATE
BACK TO THE COAST FROM MANATEE COUNTY NORTHWARD ALONG THE NATURE
COAST.
WEDNESDAY...HEIGHTS WILL BE BUILDING OVER THE PENINSULA AS UPPER
LEVEL RIDGING EXPANDS WESTWARD FROM THE BAHAMAS. A SIGNIFICANTLY
DRIER COLUMN ASSOCIATED WITH THIS FEATURE`S SUPPRESSION WILL BE
EXPANDING INTO SOUTHERN FLORIDA...HOWEVER IT APPEARS AS THOUGH THE
INFLUENCE OF THIS AIRMASS WILL REMAIN SOUTH OF OUR ZONES FOR THE
DAYLIGHT HOURS. EXPECT THE SCATTERED NOCTURNAL SHOWERS NEAR THE
COAST TO CONTINUE DURING THE MORNING HOURS AND SLOWLY BEGIN TO
MIGRATE INLAND. ONCE SEA-BREEZE CIRCULATIONS BECOME ESTABLISHED...
WILL EXPECT MORE ROBUST DEEP CONVECTION TO DEVELOP. THE GREATEST
CHANCES FOR THESE STORMS WILL BE SLIDING INLAND AS THE AFTERNOON
PROGRESSES WITH THE BEACHES LIKELY BECOMING MOSTLY DRY AFTER MID
AFTERNOON. THE BUILDING HEIGHTS WILL ALLOW HIGH TEMPS TO START
RISING A COUPLE DEGREES AS WELL.
THURSDAY...STACKED RIDGING WILL BE WELL ESTABLISHED OVER THE
FORECAST AREA. MAY SEE A FEW MORE NOCTURNAL SHOWERS OVER THE COASTAL
WATERS...WITH THE BEST CHANCES FOR ANY INLAND PENETRATION DURING THE
EARLY MORNING HOURS NORTH OF THE TAMPA BAY AREA. BY AFTERNOON...THE
SEA-BREEZE WILL BE PUSHING INLAND AND LIKELY ONCE AGAIN TAKING THE
MAJORITY OF THE SHOWERS/STORMS INLAND WITH IT. BEST CHANCES FOR THE
AFTERNOON STORMS WILL BE NORTH OF THE 1-4 CORRIDOR IN ASSOCIATED
WITH SOME STILL DECENT COLUMN MOISTURE. SOUTH OF I-4...A MUCH DRIER
AND MORE HOSTILE COLUMN FOR DEEP CONVECTION LOOKS TO BECOME
ESTABLISHED. WILL ONLY HIGHLIGHT WIDELY SCT STORMS FOR THESE INLAND
ZONES. TEMPERATURES SHOULD BE NOTICEABLY WARMER WAS WELL WITH
WIDESPREAD MIDDLE 90S AWAY FROM THE BEACHES.
&&
.LONG TERM (FRIDAY THROUGH MONDAY)...
SUB-TROPICAL RIDGE WILL BE
WELL ESTABLISHED OVER THE REGION THURSDAY NIGHT AND FRIDAY WITH SLUG
OF DRY AIR LIFTING NORTHWARD ACROSS THE REGION. WILL CONTINUE WITH
JUST A SLIGHT CHANCE OF AFTERNOON STORMS WHICH IS AT OR ABOVE 00Z
MEX GUIDANCE POPS WHICH SHOW POPS BELOW 15 PERCENT SOUTH OF TAMPA
BAY.
THE TRICKY PART OF THE FORECAST WILL BE IN THE RETURN OF MOISTURE
FROM THE SOUTH. THE SUB-TROPICAL RIDGE REMAINS STRONG OVER CENTRAL
FLORIDA WHICH WILL SERVE TO SUPPRESS AFTERNOON STORMS. BUT ITS HARD
TO IGNORE PRECIPITABLE WATERS OF OVER TWO INCHES AS WELL. DRY SLOT
ON SATURDAY IS FORECAST TO BE IN PLACE FROM THE TAMPA BAY AREA
NORTHWARD THROUGH PORTIONS OF THE NATURE COAST. OTHERWISE...HIGHER
MOISTURE WARRANTS AT LEAST A CHANCE OF AFTERNOON STORMS WITH RAIN
CHANCES NEAR 30 PERCENT AROUND FORT MYERS.
DECIDED TO STAY A BIT ABOVE GUIDANCE FOR RAIN CHANCES ON SUNDAY AND
MONDAY. THE STORY REMAINS THE SAME...HIGH MOISTURE AVAILABILITY WILL
BE OFFSET BY SUBSIDENCE UNDER THE STRONG SUB-TROPICAL RIDGE. WILL
KEEP AFTERNOON RAIN CHANCES AROUND 40 PERCENT...WHICH IS A BIT ABOVE
GUIDANCE BUT NEAR OR EVEN A BIT BELOW NORMAL FOR THIS TIME OF YEAR.
WITH THE STRONG SUB-TROPICAL RIDGE OVERHEAD...TEMPERATURES WILL SOAR
GIVEN ENOUGH SUNSHINE...ESPECIALLY AWAY FROM THE INFLUENCE OF THE
SEA BREEZES. I WOULD NOT BE SURPRISED TO SEE SOME UPPER 90S ACROSS
THE INTERIOR OVER THE WEEKEND.
&&
.AVIATION...
PERSISTENT AREA OF SHOWERS AND A FEW THUNDERSTORMS WILL CONTINUE TO
IMPACT PIE AND SRQ THROUGH THE EARLY MORNING HOURS. FMY AND RSW MAY
SEE A FEW MORNING SHOWERS...BUT BEST CHANCE AT MVFR/IFR CONDITIONS
WILL OCCUR AFTER 16Z. CONFIDENCE IN TIMING STILL TOO LOW TO
INTRODUCE TEMPO GROUPS FOR THE AFTERNOON HOURS.
&&
.MARINE...
THE SUBTROPICAL RIDGE AXIS WILL REMAIN ALIGNED ACROSS THE SOUTHERN
FLORIDA PENINSULA INTO THE EASTERN GULF OF MEXICO THROUGH THE NEXT
SEVERAL DAYS. THIS RIDGE POSITION WILL KEEP WINDS AND SEAS LOW
THROUGH THE PERIOD. LATE NIGHT AND EARLY MORNING SHOWERS AND STORMS
WILL BE FAIRLY COMMON OVER THE COASTAL WATERS THE NEXT COUPLE OF
NIGHTS.
&&
.FIRE WEATHER...
ABUNDANT LOW LEVEL MOISTURE WILL KEEP RELATIVE HUMIDITY LEVELS WELL
ABOVE CRITICAL VALUES THROUGH AT LEAST THURSDAY. NO SIGNIFICANT FIRE
WEATHER CONCERNS ARE ANTICIPATED.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 89 77 90 77 / 50 30 40 20
FMY 90 75 91 76 / 50 20 40 10
GIF 91 73 93 74 / 60 30 50 30
SRQ 89 76 90 76 / 40 30 30 10
BKV 90 71 92 72 / 50 30 50 20
SPG 89 79 90 80 / 40 30 40 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE...MROCZKA
LONG TERM/AVIATION...JILLSON
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
333 AM EDT TUE JUL 17 2012
.DISCUSSION...
TODAY-TONIGHT...
LATEST RAP ANALYSIS SHOWS A GENERAL DECREASE IN INSTABILITY OVER THE
PAST 24HRS. THE MID LVL VORTICITY FIELD OVER FL HAS BECOME SOMEWHAT
DISORGANIZED WITH NOTEWORTHY MAXES OVER N AND S PENINSULA...
SEPARATED BY AN ELONGATED MIN ALONG THE I-4 CORRIDOR. TEMPS ALOFT
HAVE WARMED A BIT WITH H50 READINGS NEAR -8C AREAWIDE. UPR LVL
DIVERGENCE FIELD HAS WEAKENED AS WELL. EVEN SO...EVENING SOUNDINGS
SHOW THE LCL AIRMASS REMAINS NEARLY SATURATED THRU THE H100-H50 LYR
WITH PW VALUES ARND 2.2" AT KTBW/KMFL. THE ATLC RIDGE AXIS IS PARKED
OVER THE FL STRAITS AND WILL INTERACT WITH AN INVERTED TROF AXIS
EXTENDING FROM THE CAROLINA COAST TO JUST N OF THE YUCATAN PENINSULA
TO PRODUCE A DEEP LYR SW FLOW ACRS CENTRAL FL.
THE TROF WILL DRIFT SLOWLY NWD THRU TONIGHT AS ANTICYCLONIC
CIRCULATIONS OVER THE DEEP S AND E OF THE BAHAMAS SQUEEZE IT FROM
BOTH FLANKS. AS A RESULT...DESPITE DECREASING INSTABILITY...CENTRAL
FL WILL REMAIN ON THE ASCENDING RIGHT SIDE OF THE TROF. THE LCL
AIRMASS REMAINS PRIMED FOR ANOTHER ROUND OF HIGH PRECIP COVERAGE
THIS AFTN WITH DEEP LOW/MID LVL MOISTURE IN PLACE. THE SWRLY
STEERING FLOW WILL FAVOR THE E FL COAST FOR TOTAL COVERAGE...MAINLY
N OF SEBASTIAN INLET AS THE W/SW FLOW WILL PLACE MARTIN/ST. LUCIE
CO. IN THE SHADOW OF LAKE OKEECHOBEE. THOUGH THE H75-H60 LYR
CONTINUES TO DISPLAY SOME RESPECTABLE LAPSE RATES...THE OVERALL
THREAT FOR STRG/SVR WX HAS DIMINISHED. PRIMARY WX THREATS WILL BE CG
LIGHTNING AND LCL FLOODING.
SCT SHRAS/ISOLD TSRAS WILL LINGER INTO THE EVENING AS THE INVERTED
TROF PUSHES NWD AND MERGES WITH A SHORT WAVE TROF OVER THE MID
ATLC/NEW ENGLAND SEABOARD. THIS WILL LEAVE THE LCL AIRMASS WITH
LITTLE TO NO DYNAMIC SUPPORT BEYOND LCL DIURNAL HEATING...THUS ANY
PRECIP SHOULD DISSIPATE BEFORE MIDNIGHT. NO CHANGE IN LOW LVL
AIRMASS... MAX/MIN TEMPS WILL BE WITHIN A DEG OR TWO OF MONDAY
READINGS.
WED-THU...MID/UPPER LEVEL CUT OFF LOW IS PROGGED TO LIFT SLOWLY
NORTH OVER GEORGIA ON WED THEN SHEAR OUT THU AS BROAD TROUGH TAKES
SHAPE OVER THE EASTERN HALF OF THE COUNTRY. HIGH MOISTURE WILL
CONTINUE ON WED ALONG WITH WESTERLY STEERING FLOW...SO HAVE GONE
ABOUT 10 PERCENT ABOVE MOS POPS.
DEEP LAYER RIDGING IS FORECAST TO BUILD IN OVER THE SOUTH CENTRAL
PENINSULA ON THU. SOME DRYING SHOULD AFFECT THE SOUTH BUT HIGHER
MOISTURE IS STILL SHOWN BY THE GFS ACROSS THE NORTH HALF. MOS POPS
ARE 20 PERCENT OR LESS AREAWIDE...BUT HAVE GONE WITH 30 PERCENT
ACROSS THE NORTH HALF WHERE MOISTURE AND WESTERLY STEERING STILL
SHOULD BE ABLE TO BRING SCATTERED COVERAGE TO THE EASTERN SIDE OF
THE PENINSULA.
A LITTLE MORE SUNSHINE WILL ALLOW MAX TEMPERATURES TO CLIMB INTO
THE MID 90S ACROSS THE INTERIOR AND POSSIBLY THE NORTH COAST WHERE
THE SEA BREEZE SHOULD BE INHIBITED.
FRI-SAT...DEEP LAYER RIDGE AXIS IS STILL FORECAST TO BUILD A
LITTLE FARTHER NORTH TO THE CENTRAL PENINSULA FRI WITH CONTINUED
DRYING WORKING UP FROM THE SOUTH. THE EAST/WEST COAST BOUNDARY
COLLISION ACROSS THE INTERIOR AND NORTH COAST SHOULD GENERATE
ISOLATED STORMS LATE IN THE DAY AND HAVE GONE WITH 20 PERCENT POPS
THERE. THE SPACE AND TREASURE COAST SHOULD ESCAPE STORMS ON FRI.
THE SAME GENERAL PATTERN WILL CONTINUE INTO SAT...THOUGH THE 00Z
GFS INDICATES SOME MOISTURE LIFTING INTO SOUTHERN SECTIONS. MOS
POPS ARE 25 TO 30 PERCENT AREAWIDE ON SAT BUT HAVE JUST INDICATED
20 PERCENT FOR NOW.
LITTLE CHANGE IN MAX TEMPERATURES...LOW-MID 90S...BUT WITH LOW
COVERAGE AND LATE OCCURRENCE OF STORMS...IT WILL FEEL HOTTER.
SUN-TUE...TROUGHING OVER THE EASTERN PART OF THE COUNTRY WILL KEEP
DEEP LAYER RIDGE AXIS DRAPED ACROSS THE FLORIDA PENINSULA. THE 00Z
GFS/ECMWF SHOW HIGHER MOISTURE LIFTING BACK ACROSS THE ENTIRE
AREA ON SUNDAY AND CONTINUING INTO MON. THIS SHOULD BRING A
TYPICAL SCATTERED COVERAGE OF AFTERNOON SHOWERS/STORMS...WITH
INTERIOR SECTIONS THE MOST FAVORED. THE MODELS INDICATE SOME
DRYING WORKING IN FROM THE SOUTHEAST TUE...BUT WILL NOT DEVIATE
FROM THE MOS POPS WHICH ARE 30-40 PERCENT.
&&
.AVIATION...
THRU 17/15Z...BRIEF IFR CIGS/MVFR VSBYS IN BR N OF KISM-KTTS...VCSH
S OF KFPR-KOBE WITH OCNL CIGS BTWN FL040-060...VFR ELSEWHERE.
BTWN 17/15Z-17/18Z...SFC WNDSHFT FROM SW TO S/SE COASTAL SITES
ASSOCD WITH THE E COAST SEA BREEZE...SEA BREEZE NOT EXPECTED TO
ADVANCE PAST THE I-95 CORRIDOR....SCT MVFR SHRAS/ISOLD IFR TSRAS ALL
SITES.
BTWN 17/18Z-17/24Z...VCTS ALL SITES WITH NMRS MVFR SHRAS AND SCT IFR
TSRAS DVLPG AREAWIDE...OCNL SFC WND G22KTS NEAR TSRAS.
BTWN 18/00Z-18/03Z...VCSH ALL SITES WITH SCT MVFR SHRAS AND ISOLD
IFR TSRAS.
AFT 18/03Z...PREVAILING VFR ALL SITES WITH CIGS AOA FL120...BRIEF
IFR CIGS N OF KISM-KEVB.
&&
.MARINE...
TODAY-TONIGHT...ATLC RIDGE OVER THE FL STRAITS WILL GENERATE A LIGHT
TO GENTLE SW BREEZE AREAWIDE. WINDS WILL VEER TO THE S/SE NEAR THE
COAST IN THE AFTN AS THE EAST COAST SEA BREEZE FORMS...BUT WILL
SHIFT BACK TO THE SW SHORTLY AFT SUNSET. INCREASED POTENTIAL FOR
OFFSHORE MOVING TSTMS...ESPECIALLY N OF SEBASTIAN INLET. SEAS
2-3FT NEARSHORE AND 3-4FT OFFSHORE...LARGELY IN AN ERLY SWELL.
DOMINANT PDS BTWN 9-10 SEC.
WED-THU...SOUTH/SOUTHWEST FLOW SHOULD PERSIST AS AXIS OF ATLANTIC
SURFACE RIDGE LIFTS SLOWLY TOWARDS THE CENTRAL PENINSULA. SPEEDS
SHOULD BE AROUND 10 KNOTS...WITH SOME NOCTURNAL INCREASE TO 10-15
KNOTS ACROSS NORTHERN SECTIONS. SCATTERED STORMS ARE EXPECTED TO
PUSH OFF THE MAINLAND ON WED AND POSSIBLE AGAIN ON THU FROM ABOUT
SEBASTIAN INLET NORTH.
FRI-SAT...VERY LITTLE CHANGE IN THE SURFACE RIDGE POSITION AND
HENCE THE WINDS. WEAKER STEERING LEVEL WINDS AND DRIER AIR SHOULD
INHIBIT STORMS FROM AFFECTING THE ATLANTIC.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 89 74 93 76 / 70 40 50 20
MCO 91 74 94 75 / 60 30 50 20
MLB 89 74 92 75 / 70 40 50 20
VRB 89 73 92 76 / 70 40 40 20
LEE 91 75 94 77 / 60 30 50 20
SFB 92 75 95 77 / 60 30 50 20
ORL 91 75 95 78 / 60 30 50 20
FPR 89 74 91 75 / 60 40 40 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM....LASCODY
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
513 AM EDT TUE JUL 17 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 512 AM EDT TUE JUL 17 2012
MAIN FCST CONCERN IN THE SHORT TERM WILL BE PCPN CHANCES. WATER
VAPOR IMAGERY AND RUC ANALYSIS SHOW CNTRL CONUS RIDGE LOSING SOME
AMPLITUDE AS A BROAD TROF SETTLES INTO SE CANADA. ALTHOUGH COLD
FRONT ASSOCIATED WITH SE CANADA TROF IS DROPPING S THRU UPPER
MI...VERY LITTLE CONVECTION HAS OCCURRED IN THE VCNTY OF IT. LITTLE
FORCING IN THE PRESENCE OF WARM MID LEVEL TEMPS PER 00Z KINL/KGRB
SOUNDINGS HAS BEEN WORKING AGAINST SHRA/TSRA DEVELOPMENT SO FAR.
SOUTHWARD MOVING COLD FRONT SHOULD HAVE CLEARED ALL OF THE FCST AREA
AT 12Z THIS MORNING...EXCEPT THE FAR SCNTRL AROUND KMNN. WITH FRONT
CONTINUING TO SETTLE S TODAY...IT WOULD APPEAR THERE IS LITTLE RISK
OF PCPN. HOWEVER...SUBTLE SHORTWAVE CURRENTLY ASSOCIATED WITH
CONVECTION IN NRN SD WILL BE TRACKING E AND COULD PROVIDE LIFT OVER
THE SFC BOUNDARY...POSSIBLY RESULTING IN SOME SHRA ACROSS THE AREA
THIS MORNING AND THEN ACROSS THE SCNTRL THIS AFTN. POTENTIAL FOR
TSRA WILL BE DIMINISHING WITH TIME AS INSTABILITY WEAKENS PER NAM
MLCAPE PROGS. OTHER ISSUE TODAY IS FOG. QUITE A BIT OF FOG/STRATUS
HAS PLAGUED LAKE SUPERIOR OVER THE LAST COUPLE OF DAYS. THAT MAY
STILL BE THE CASE. UNFORTUNATELY...STRATOCU IS OBSCURING A BETTER
LOOK BELOW ON 11-3.9MICRON SATELLITE IMAGERY. WHETHER OR NOT THERE
IS FOG ON THE LAKE...WITH A STEADY NRLY FLOW PUSHING MARINE LAYER
INLAND/UPSLOPE EARLY THIS MORNING...WILL ASSUME THERE COULD BE SOME
FOG...ESPECIALLY OVER THE HIGHER TERRAIN AS THE COOLER AIR
ENCOUNTERS INITIALLY HIGHER DWPTS.
WHILE A SHRA MAY LINGER OVER THE FAR SCNTRL EARLY THIS EVENING...DRY
WEATHER SHOULD RULE TONIGHT AS SFC HIGH PRES BUILDS S. HOWEVER...IT
IS NOTED THAT SOME OF THE GLOBAL MODELS DO SHOW PCPN BRUSHING THE SW
FCST AREA DURING THE NIGHT...A RESULT OF WEAK WAA OVER SFC COLD
FRONT THAT PASSED TODAY. BASED ON LOCATION OF SFC/850MB FRONTS IN
THOSE MODELS...IT APPEARS PCPN IS BEING GENERATED TOO FAR TO THE NE.
NONETHELESS...IT WILL BE SOMETHING TO KEEP IN MIND FOR LATER
FORECASTS. IT WILL BE A MUCH MORE COMFORTABLE NIGHT FOR SLEEPING AS
TEMPS DROP INTO THE 50S AWAY FROM THE LAKESHORES. DEPENDING ON SKY
COVER...TEMPS IN THE TRADITIONAL COOL SPOTS COULD SLIP INTO THE
UPPER 40S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 512 AM EDT TUE JUL 17 2012
WEDNESDAY THROUGH FRIDAY...AS THE UPPER LEVEL LOW CENTERED OVER
NORTHERN QUEBEC SHIFTS SLOWLY TO THE SOUTHEAST WEDNESDAY...A HIGH
PRESSURE RIDGE ORIENTED FROM NORTH TO SOUTH OVER MANITOBA INTO THE
NORTHERN PLAINS WILL BEGIN TO BUILD EASTWARD INTO MUCH OF THE UPPER
GREAT LAKES REGION THROUGH MUCH OF THE DAY FRIDAY. THIS WILL ALLOW A
SURFACE RIDGE OVER CENTRAL CANADA TO EXPAND SOUTH AND EASTWARD
ENCOMPASSING MUCH OF THE GREAT LAKES REGION THROUGH FRIDAY
AFTERNOON. THE HIGH PRESSURE RIDGE ALONG WITH LITTLE MOISTURE SHOULD
HELP KEEP MOST OF THE UPPER PENINSULA DRY THROUGH THIS TIME PERIOD
WITH THE EXCEPTION OF WEDNESDAY NIGHT INTO EARLY THURSDAY ALONG THE
WISCONSIN BORDER AS MANY OF THE MODELS BRING A SHORTWAVE THROUGH THE
AREA AROUND THIS TIME. AS PREVIOUS SHIFT MENTIONED COOLEST
TEMPERATURES WILL LIKELY BE WEDNESDAY AS THE HIGHER HEIGHTS
ASSOCIATED WITH THE RIDGE SHOULD HOLD OFF UNTIL LATER IN THE
WEEK...ALLOWING FOR A GRADUAL WARMING TREND THURSDAY AND
FRIDAY...BEFORE WARMING MORE RAPIDLY OVER THE WEEKEND.
FRIDAY NIGHT THROUGH MONDAY...AS UPPER LEVEL TROUGHING BEGINS TO
MOVE INTO THE PACIFIC NORTHWEST THROUGH FRIDAY AFTERNOON...EXPECT
THE UPPER LEVEL RIDGE SHOWN AT H500 TO INTENSIFY. THIS SHOULD HELP
TO INCREASE TEMPERATURES ACROSS THE REGION THROUGH THE WEEKEND INTO
THE FIRST PART OF NEXT WEEK. AT THIS POINT THE WARMEST TEMPERATURES
WILL LIKELY MOVE INTO THE REGION OVER THE WEEKEND WITH TEMPERATURES
APPROACHING OR EXCEEDING THE 90 DEGREE MARK. BY MONDAY THE GFS AND
EC ARE IN AGREEMENT THAT THE UPPER LEVEL TROUGH OVER THE PACIFIC
NORTHWEST WILL SHIFT TO NORTHERN MANITOBA...WHICH SHOULD HELP TO
WEAKEN THE RIDGE THROUGH OUT THE DAY...KEEPING TEMPERATURES SLIGHTLY
COOLER. THERE ARE A FEW CHANCES OF SHOWERS AND THUNDERSTORMS THROUGH
THIS PERIOD AS SEVERAL SHORT WAVES ROTATE AROUND THE RIDGE. THE BEST
CHANCE OF PRECIPITATION WOULD LIKELY BE FRIDAY NIGHT INTO SATURDAY
AS ONE OF THE WAVES PASS THROUGH AND THEN AGAIN SUNDAY NIGHT INTO
EARLY MONDAY AS THE NEXT WAVE AN ASSOCIATED WEAK COLD FRONT MOVE
INTO THE AREA. ONE LIMITING FACTOR FOR EACH SHORTWAVE WILL LIKELY BE
THE LACK OF MOISTURE AVAILABLE. WINDS SHOULD REMAIN FAIRLY WEAK AND
A MAJORITY OF THE ISOBARS ARE CLOSED TO THE GULF...WHICH INDICATES A
REDUCTION IN THE AMOUNT OF MOISTURE TRANSPORT INTO THE REGION. AN
ADDITIONAL LIMITING FACTOR FOR THE SHORTWAVE MOVING INTO THE REGION
SUNDAY NIGHT INTO MONDAY WILL BE THE PRESENCE OF A LARGE CAP WITH
H850 TEMPS PROGGED TO BE AOA 21 DEGREES CELSIUS...SO ANY STORM
DEVELOPMENT MAY BE CONFINED ALONG THE COLD FRONT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 137 AM EDT TUE JUL 17 2012
A COLD FRONT WILL DROP SOUTH ACROSS THE AREA OVERNIGHT. SINCE FOG HAS
BEEN PRESENT OVER LAKE SUPERIOR...WIND SHIFT TO THE N SHOULD BRING
IFR/POTENTIAL LIFR CONDITIONS TO ALL SITES AFTER FROPA OVERNIGHT. LOW
CONFIDENCE IN SHRA/TSRA ACCOMPANYING FRONT WITH MOST OF THE PCPN
REMAINING TO THE NORTH AND EAST. EXPECT DRIER AIR MOVING IN WITH ACYC
NRLY FLOW TO BRING IMPROVING CONDITIONS BY AFTERNOON.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 512 AM EDT TUE JUL 17 2012
FOG HAD BEEN AN ISSUE OVER THE LAST COUPLE OF DAYS. HOWEVER...BASED
ON A FEW SHIP OBS OVERNIGHT...IT APPEARS FOG HAS EITHER DISSIPATED
OR COVERAGE HAS BECOME PATCHY. WILL KEEP A MENTION OF PATCHY FOG IN
THE MORNING. OTHERWISE...AN EXTENDED PERIOD OF GOOD VIS IS SETTING
UP AS DRIER AIR WORKS INTO THE AREA FOR SEVERAL DAYS.
AS FOR WINDS...WITH HIGH PRES BUILDING S TOWARD THE UPPER LAKES
TODAY AND THEN DOMINATING THE AREA THRU FRI...WINDS WILL BE ON THE
LIGHT SIDE. THE STRONGEST WINDS (UP AROUND 15KT) WILL OCCUR TODAY AS
THE HIGH BUILDS S TOWARD THE AREA. LOCALLY HIGHER WINDS...AGAIN UP
AROUND 15KT...WILL OCCUR WED OVER THE W AND ALSO OVER THE FAR ERN
PORTION OF THE LAKE AS MESO HIGH DEVELOPS OVER CNTRL LAKE SUPERIOR.
WINDS THU/FRI SHOULD BE 10KT OR LESS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KEC
AVIATION...JLB
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
1100 PM MDT MON JUL 16 2012
AVIATION SECTION UPDATED
.DISCUSSION...
UPDATE FORTHCOMING. HAVE LOWERED POPS ACROSS MOST OF THE COUNTY
WARNING AREA. THE UPPER LOW ALONG THE CALIFORNIA/OREGON COAST IS
WELL DEPICTED BY SATELLITE IMAGERY AND CONTINUES TO SEND MOISTURE
AND SHORT WAVE ENERGY ACROSS SOUTHWEST MONTANA...INTO NORTH CENTRAL
MONTANA. SHOWERS AND THUNDERSTORMS THAT HAVE DEVELOPED ARE GENERALLY
ISOLATED IN NATURE AND ARE MAINLY PRODUCING BRIEF HEAVY RAIN DUE TO
CONTINUED HIGH PRECIPITABLE WATER VALUES. HAVE DROPPED POPS BACK
INTO THE SCATTERED CATEGORY. HRRR ANALYSIS CONTINUES TO SHOW
CONVECTIVE ACTIVITY CONTINUING THROUGH THE EVENING BEFORE
DIMINISHING AFTER 09Z. TEMPERATURE FORECASTS LOOK ON TRACK. EMANUEL
&&
.AVIATION...
UPDATED 0500Z.
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DIMINISH OVER THE
REGION...WITH MOST ACTIVITY DIMINISHING AFTER 09Z...HOWEVER MORE
STORMS WILL REDEVELOP AFTER 14Z IN NORTH CENTRAL MONTANA...AND AFTER
19Z IN SOUTHWEST MONTANA. SOME STORMS COULD PRODUCE BRIEF HEAVY
RAIN. BRUSDA
&&
.PREV DISCUSSION...ISSUED 251 PM MDT MON JUL 16 2012
TONIGHT THROUGH WEDNESDAY...A WEATHER DISTURBANCE ALOFT OVER
SOUTHERN IDAHO MONDAY AFTERNOON WILL BE MOVING NORTH TONIGHT. IT
WILL MOVE INTO SOUTHWEST MONTANA THIS EVENING AND REACH CENTRAL
MONTANA LATE TONIGHT. MONSOONAL MOISTURE IS ASSOCIATED WITH THE
DISTURBANCE ALONG WITH INSTABILITY. WILL GO WITH SCATTERED SHOWERS
AND THUNDERSTORMS FOR MOST LOWER ELEVATIONS WITH MORE WIDESPREAD
SHOWERS AND THUNDERSTORMS IN THE MOUNTAINS OVER SOUTHWEST AND
CENTRAL MONTANA. THE PLAINS OF NORTHERN MOUNTAIN WILL CONTINUE
RELATIVELY DRIER UNTIL THURSDAY WHEN THE DISTURBANCE REACHES THAT
AREA. EVEN THOUGH SOUTHWEST AND MOST OF CENTRAL MONTANA WILL BE
SOUTH OF THE DISTURBANCE TUESDAY AFTERNOON AND SOMEWHAT
DRIER..THERE WILL AGAIN BE INSTABILITY OVER THAT AREA SO WILL
CONTINUE THE IDEA OF A CHANCE OF SHOWERS AND THUNDERSTORMS. AS THE
DISTURBANCE MOVES INTO CANADA BY TUESDAY EVENING A DRIER AIRMASS
WILL SPREAD OVER THE FORECAST AREA RESULTING IN MOSTLY CLEAR SKIES
WITH LITTLE IF ANY THREAT OF PRECIPITATION. STILL SEE A WARMING
TREND TUESDAY AND WEDNESDAY AND ESPECIALLY WEDNESDAY WITH HIGHS
THAT DAY EXPECTED TO BE SOME 5 TO 10 DEGREES WARMER THAN THOSE OF
TUESDAY. BLANK
WEDNESDAY NIGHT THROUGH MONDAY NIGHT...A LOW PRESSURE TROF WILL
BE OVER THE PACIFIC NORTHWEST WEDNESDAY NIGHT WITH
UNSETTLED...SOUTHWEST FLOW ALOFT OVER THE ZONES. A SHORTWAVE WILL
MOVE THROUGH THIS FLOW ALOFT THURSDAY. THE AIRMASS SHOULD BE VERY
DRY ACROSS THE SOUTHWEST ZONES AND MOST INSTABILITY AND CONVECTION
IS EXPECTED TO THE NORTH. THE TROF WILL REMAIN OVER THE PACIFIC
NORTHWEST FRIDAY ALTHOUGH THE AIRMASS WILL BE QUITE DRY AND THE
CHANCE OF AFTERNOON CONVECTION WILL BE SLIGHT. THE UPPER LEVEL
TROF WILL FINALLY MOVE EAST SATURDAY BUT THE LOW WILL BE QUITE FAR
NORTH...CROSSING THROUGH ALBERTA. CENTRAL MONTANA WILL REMAIN
QUITE DRY. HIGH PRESSURE AND CONTINUED VERY WARM TEMPERATURES WILL
CONTINUE THROUGH MONDAY. AT THIS TIME...A RETURN OF MONSOONAL
MOISTURE IS POSSIBLE ACROSS THE SOUTHWEST ZONES MONDAY AND THE
POSSIBILITY OF AFTERNOON CONVECTION WILL INCREASE. ZELZER
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 57 83 60 94 / 30 40 20 10
CTB 53 75 55 90 / 30 50 30 10
HLN 58 87 58 93 / 60 40 20 10
BZN 51 88 50 93 / 50 30 20 10
WEY 42 75 40 80 / 40 30 10 10
DLN 51 81 51 88 / 40 30 20 10
HVR 57 84 59 95 / 20 50 30 10
LWT 55 83 56 90 / 50 50 30 10
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...EMANUEL/BLANK
LONG TERM...ZELZER
AVIATION...BRUSDA
WEATHER.GOV/GREATFALLS
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
347 AM EDT TUE JUL 17 2012
.SYNOPSIS...
A TROUGH OF LOW PRESSURE WILL LINGER OVER INLAND AREAS THROUGH
THURSDAY. A COLD FRONT WILL MOVE INTO THE AREA FRIDAY AND STALL
THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 335 AM TUESDAY...UPPER AIR ANALYSIS SHOWS A WEAK EAST-WEST
ORIENTED 500 MB TROUGH ACROSS EASTERN NORTH CAROLINA WITH A CLOSED
UPPER LOW OVER NORTHEASTERN FLORIDA. WHILE THE TROUGH GRADUALLY
LIFTS OUT...LEAVING EASTERN NC IN A COL AREA...THERE IS STILL SOME
DECENT MID-LEVEL VORTICITY AROUND DURING THE MID-AFTERNOON HOURS. AT
THE SURFACE A TROUGH LINGERS OVER THE PIEDMONT REGION AS HIGH PRESSURE
WELL OFFSHORE CONTINUES TO PROVIDE WARM...MOISTURE AND UNSTABLE TO
EASTERN NC. BOTH THE RAP AND GFS INDICATE THAT GIVEN MAX
TEMPERATURES INTO THE LOWER 90S AND DEWPOINTS IN THE LOWER AND
MIDDLE 70S LATER THIS AFTERNOON...CAPE VALUES IN EXCESS OF 3000
J/KG AND LI VALUES OF -6 TO -8 ARE FORECAST. GIVEN THESE
FACTORS...THINK ANOTHER GOOD COVERAGE OF SHOWERS AND TSTMS CAN BE
EXPECTED WITH THE HIGHEST PROBABILITY IN AREAS SIMILAR TO
YESTERDAY OVER THE NORTHWESTERN CWA WITH POPS TAPERING BACK TO
MINIMAL NEAR THE SOUTHERN COASTAL AREA. WILL AGAIN HIGHLIGHT
LOCALLY STRONG STORMS IN THE HAZARDOUS WEATHER OUTLOOK.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
AS OF 340 AM TUESDAY...SHOWERS AND TSTMS WILL ONCE AGAIN DISSIPATE
WITH LOSS OF HEATING AFTER ABOUT 02Z. MINIMUM TEMPERATURES WILL
AGAIN BE BETWEEN 73 AND 78 DEGREES WITH LIKELY SOME LEFTOVER HIGH
DEBRIS CLOUDS FROM ANY CONVECTION THAT DEVELOPS DURING THE
AFTERNOON AND EVENING HOURS.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 330 AM TUE...LONG TERM PERIOD WILL FEATURE THE POTENTIAL FOR
PERIODS OF WIDESPREAD HEAVY RAIN THIS WEEKEND. FOR WED AND THUR...E
NC WILL REMAIN IN TYPICAL SUMMER REGIME WITH ISO-SCT AFTERNOON
THUNDERSTORMS MAINLY ASSOCIATED WITH SEA BREEZE FRONT.
WEAKNESS IN THE MID LEVELS WILL BRING A CHANCE OF DIURNAL CONVECTION
ACROSS INLAND AREAS WED AFTERNOON. SUBTROPICAL MOISTURE WILL STREAM
NORTHEASTWARD OFF THE COAST WED NIGHT...AND WILL BRING SCT
THUNDERSTORMS FOR THE COASTAL WATERS. SOME OF THIS CONVECTION MAY
ADVECT OFF THE OCEAN AND AFFECT THE COASTAL COUNTIES LATE WED NIGHT.
FOR THUR...PIEDMONT THERMAL TROUGH WILL STRENGTHEN SOMEWHAT IN
RESPONSE TO BUILDING CENTRAL CONUS RIDGE AND DIGGING OF EASTERN
CONUS TROUGH. SOMEWHAT BETTER CHANCE FOR MORE ORGANIZED CONVECTION
WELL INLAND NEARER THE THERMAL TROUGH. BOTH GFS AND ECMWF IN FAIRLY
GOOD AGREEMENT WITH THE SYNOPTIC REGIME THROUGH THIS WEEKEND...
THOUGH SOME TIMING DIFFERENCES IN ARRIVAL OF SFC BOUNDARY THAT WILL
SET THE STAGE FOR POSSIBLE PERIODS OF HEAVY RAIN THIS WEEKEND. SIDED
WITH MORE CONSISTENT/SLOWER ECM SOLN...AS THIS HAS SUPPORT FROM ITS
ENSEMBLE MEAN...GEFS ENSEMBLE MEAN SOLN...AND OPERATIONAL 17/00Z
CANADIAN MODEL. THIS SOLN HANGS UP THE EAST-WEST ORIENTED FRONT
THROUGH THE WEEKEND...AND WITH PWATS AROUND 2.25 INCHES OR HIGHER...
COULD BRING THREAT FOR FLOODING. IF THESE PWAT VALS COME TO
FRUITION...THEY WOULD BE NEAR THE 99TH PERCENTILE FOR CLIMATOLOGICAL
VALUES FOR JULY...WHICH COULD CERTAINLY POSE THREAT FOR FLOODING
RAINS. THE UNSETTLED WEATHER MAY LINGER INTO THE BEGINNING OF NEXT
WEEK.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH 00Z WEDNESDAY/...
AS OF 1250 AM TUESDAY...WILL CONTINUE PREVIOUS TAF FORECAST OF
SHOWING SOME PATCHY FOG AT EWN WHERE HEAVY RAINFALL OCCURRED IN
THUNDERSTORMS EARLIER THIS EVENING. OTHERWISE...EXPECT VFR
CONDITIONS WITH A BIT OF A LIGHT SOUTHWEST BREEZE PREVENTING ANY
DENSE FOG AT THE REMAINING TERMINALS. ONCE AGAIN...SCATTERED TSTMS
WILL BE A GOOD POSSIBILITY LATER TODAY...ESPECIALLY AT KPGV AND
PERHAPS AGAIN AT KEWN/KISO.
LONG TERM /TUE NIGHT THROUGH SAT/
AS OF 330 AM TUESDAY...MAINLY VFR CONDITIONS OTHER THAN SOME TEMPO
REDUCTION TO VSBYS/CIGS LATE AT NIGHT/EARLY IN THE MORNING DUE TO
RADIATION FOG/BR. SMALL CHANCES OF AFTERNOON THUNDERSTORMS DUE TO
SEA BREEZE FRONT PROPAGATING INLAND EACH AFTERNOON. BETTER CHANCE
FOR WIDESPREAD RAIN AND THUNDERSTORMS ARRIVES ON FRIDAY AND WILL
LINGER INTO THE WEEKEND...WITH PERIODS OF IFR CONDITIONS POSSIBLE.
&&
.MARINE...
SHORT TERM /THROUGH TUESDAY...
AS OF 345 AM TUESDAY...THE SAME PATTERN THAT WE HAVE SEEN OVER THE
PAST SEVERAL DAYS WILL CONTINUE. GRADIENT BETWEEN SURFACE TROUGH
OVER THE PIEDMONT REGION AND THE SEMI-PERMANENT BERMUDA HIGH
OFFSHORE WILL LEAD TO STOUTEST WINDS OF 10 TO 15 KNOTS WITH
OCCASIONAL GUSTS TO 20 KNOTS. SEAS WILL RUN 2 TO 4 FEET WITH
OCCASIONAL 5 FOOT SEAS OVER THE OUTER WATERS...ESPECIALLY IN THE
CENTRAL WATERS.
LONG TERM /TUE NIGHT THROUGH SAT/
AS OF 330 AM TUE...LATEST RUN OF THE MAJOR MODELS IN VERY CLOSE
AGREEMENT THROUGH LATE WEEK. STILL PREFER THE 00Z ECMWF HANDLING OF
THE SOUTHWARD MOVING COOL FRONT THIS WEEKEND...WHICH HANGS UP THE
FRONT OVER EASTERN NC THIS WEEKEND. THE GFS PUSHES THE FRONT TO THE
SOUTH WHICH IS HARD TO DO THIS TIME OF YEAR. SOUTHWEST FLOW
CONTINUES THROUGH FRIDAY. EXPECTING A NORTHEAST FLOW OVER THE
CENTRAL AND NORTHERN WATERS SATURDAY AND SUNDAY NORTH OF THE FRONT
WITH A SOUTHWEST FLOW OVER THE SOUTHERN WATERS. STILL LOOKING AT
SMALL CRAFT SEAS DEVELOPING OVER THE CENTRAL AND SOUTHERN WATERS
LATE WED NIGHT THROUGH FRIDAY NIGHT AHEAD OF THE FRONT. WINDS AND
SEAS SHOULD FALL BELOW SCA THIS WEEKEND WITH FRONT OVERHEAD.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...TL
AVIATION...CTC/TL
MARINE...CTC/TL
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
305 AM EDT TUE JUL 17 2012
.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL UNTIL WEDNESDAY...WITH HOT DAYS AND
MUGGY NIGHTS ACROSS THE LOWLANDS. A COLD FRONT SINKS SOUTHEAST
ON THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
HOT AND HUMID AIRMASS MOVING INTO REGION...AS AN UPPER LEVEL RIDGE
BROADENS OVER FORECAST AREA TODAY. WITH ABUNDANT LOW LEVEL MOISTURE
AND GOOD DAYTIME HEATING...EXPECTING ISOLATED CONVECTION TODAY. NAM
DOES KEEP THE BULK OF IT WEST OF THE FORECAST AREA...IN CENTRAL
KY...TIED TO AN UPPER LEVEL DISTURBANCE SLIDING SOUTH THERE. GFS
PAINTS A LITTLE MORE PRECIP INTO THE FORECAST AREA THIS
AFTERNOON...AND RAP SOUNDINGS SHOW MODEST INSTABILITY...SO EXPANDED
THE AREAL COVERAGE OF THE SLIGHT CHANCE POPS A BIT FOR THIS
AFTERNOON...BUT STILL THINK THINGS SHOULD BE MOSTLY ISOLATED.
MODEL GUIDANCE FOR AFTERNOON HIGHS GENERALLY A BIT WARMER THAN
PREVIOUS FORECAST...SO BUMPED UP HIGHS A BIT. COMBINED WITH
DEWPOINTS CLIMBING INTO THE 70S...THIS PRODUCED HEAT INDEX VALUES
AROUND TO JUST ABOVE 100 DEGREES ALONG AND WEST OF THE OHIO RIVER.
ISSUED HEAT ADVISORY FOR THESE AREAS. EXPECTING A MUGGY NIGHT
TONIGHT WITH TEMPS ONLY DROPPING INTO THE LOW 70S ACROSS MUCH OF THE
LOWLANDS. MOST GUIDANCE VERY CLOSE FOR LOWS TONIGHT...SO BLENDED IN
NEW 00Z MOS.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
5H RIDGE IN PLACE AS TROUGH SAGS ACROSS EASTERN CANADA THROUGH THE
PERIOD. BAROCLINIC ZONE WILL BE DRAPED ACROSS THE GREAT LAKES AND
WILL SLOWLY NUDGE SOUTHWARD WITH TIME. THIS LEADS TO MOISTENING AND
DESTABILIZATION OF THE ATMOSPHERIC COLUMN LATE WEDNESDAY NIGHT INTO
THURSDAY. THUS HAVE NUDGED POP VALUES HIGHER TO ACCOUNT FOR INCREASE
IN MOISTURE.
MODELS GENERALLY AGREE WITH IDEA OF SLOWLY TRANSITIONING THE FRONT
INTO CWA WED NIGHT...WITH BOUNDARY STAYING TO OUR SOUTH INTO
FRIDAY. THIS SHOULD LEAD TO A PERIOD OF UNSETTLED WEATHER...
ESPECIALLY IN THE AFTERNOON WHEN BOUNDARY LAYER HEATING IS
MAXIMIZED. FOR TEMPS...USED MAINLY INHERITED VALUES WITH MINOR
CHANGES BASED ON LATEST MOS GUIDANCE.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
DRIER AIR WILL MOVE INTO THE CWA FOR FRIDAY BEHIND THE FRONT...WITH
A NORTHWESTERLY FLOW PATTERN ALOFT SETTING UP ACROSS THE CWA...AND
COOLER WEATHER TAKING HOLD. STILL LOOKING AT A CHANCE FOR SHOWERS
AND THUNDERSTORMS IN THE EXTENDED AS WEAK RIPPLES IN THE FLOW WILL
KEEP A MENTION...ESPECIALLY DOWN SOUTH WHERE BETTER MOISTURE WILL
EXIST. TEMPERATURES WILL BEGIN TO WARM BY THE WEEKEND AS HIGH OVER
CENTRAL U.S. BUILDS EAST.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
AREAS OF FOG STARTING TO SHOW UP IN OBS...LIKE KEKN. IN GENERAL
EXPECT AREAS OF MVFR VISIBILITIES THROUGH 12Z OR SO...DROPPING
INTO IFR IN MOST PRONE LOCATIONS LIKE KEKN. SHOULD RETURN TO VFR
FOR BULK OF THE DAY TUESDAY. HOWEVER...WITH LOTS OF LOW LEVEL
MOISTURE...EXPECT ISOLATED DIURNAL CONVECTION ON TUESDAY
AFTERNOON.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: TIMING AND DENSITY OF FOG MAY VARY.
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 TUE 07/17/12
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EDT 1HRLY 04 05 06 07 08 09 10 11 12 13 14 15
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY M M M H H M H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY L L L L L L H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 06Z WEDNESDAY...
MORE WIDESPREAD CONVECTION EXPECTED WEDNESDAY AFTERNOON AND
WEDNESDAY NIGHT...WITH IFR IN HEAVIER SHOWERS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
WVZ005>011-014.
OH...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
OHZ066-067-075-076-083>087.
KY...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
KYZ101-103.
VA...NONE.
&&
$$
SYNOPSIS...MZ
NEAR TERM...MZ
SHORT TERM...KMC
LONG TERM...SL
AVIATION...MZ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
853 AM EDT TUE JUL 17 2012
.UPDATE...
ISSUED AT 852 AM EDT TUE JUL 17 2012
ADDED DRIZZLE TO NORTH CENTRAL UPR MICHIGAN...ROUGHLY NEGAUNEE TO
MUNISING WITH MOIST NORTHERLY FLOW. MAINLY A HIGHER TERRAIN ISSUE.
OTHERWISE...KEPT TSRA MENTION FOR TODAY RESTRICTED TO VCNTY OF WI
BORDER AS COMPLEX OF SHRA/TSRA NEAR KDLH IS EXPECTED TO PROPEL ESE
THROUGH THE EARLY AFTN. FINALLY...BASED ON SFC OBS AND WEB CAMS
TRIMMED FOG OUT OF MOST CWA EXCEPT NORTH CENTRAL DUE TO THE SLIGHTLY
CONVERGENT NORTHERLY FLOW OFF LK SUPERIOR. NO OTHER CHANGES NEEDED
AT THIS POINT.
COOLER TEMPERATURES ARE LIKELY MOST NOTABLE WEATHER EVERYONE WILL
KEY IN ON TODAY. CURRENT FCST HAS FINE HANDLE ON TEMP TRENDS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 512 AM EDT TUE JUL 17 2012
MAIN FCST CONCERN IN THE SHORT TERM WILL BE PCPN CHANCES. WATER
VAPOR IMAGERY AND RUC ANALYSIS SHOW CNTRL CONUS RIDGE LOSING SOME
AMPLITUDE AS A BROAD TROF SETTLES INTO SE CANADA. ALTHOUGH COLD
FRONT ASSOCIATED WITH SE CANADA TROF IS DROPPING S THRU UPPER
MI...VERY LITTLE CONVECTION HAS OCCURRED IN THE VCNTY OF IT. LITTLE
FORCING IN THE PRESENCE OF WARM MID LEVEL TEMPS PER 00Z KINL/KGRB
SOUNDINGS HAS BEEN WORKING AGAINST SHRA/TSRA DEVELOPMENT SO FAR.
SOUTHWARD MOVING COLD FRONT SHOULD HAVE CLEARED ALL OF THE FCST AREA
AT 12Z THIS MORNING...EXCEPT THE FAR SCNTRL AROUND KMNN. WITH FRONT
CONTINUING TO SETTLE S TODAY...IT WOULD APPEAR THERE IS LITTLE RISK
OF PCPN. HOWEVER...SUBTLE SHORTWAVE CURRENTLY ASSOCIATED WITH
CONVECTION IN NRN SD WILL BE TRACKING E AND COULD PROVIDE LIFT OVER
THE SFC BOUNDARY...POSSIBLY RESULTING IN SOME SHRA ACROSS THE AREA
THIS MORNING AND THEN ACROSS THE SCNTRL THIS AFTN. POTENTIAL FOR
TSRA WILL BE DIMINISHING WITH TIME AS INSTABILITY WEAKENS PER NAM
MLCAPE PROGS. OTHER ISSUE TODAY IS FOG. QUITE A BIT OF FOG/STRATUS
HAS PLAGUED LAKE SUPERIOR OVER THE LAST COUPLE OF DAYS. THAT MAY
STILL BE THE CASE. UNFORTUNATELY...STRATOCU IS OBSCURING A BETTER
LOOK BELOW ON 11-3.9MICRON SATELLITE IMAGERY. WHETHER OR NOT THERE
IS FOG ON THE LAKE...WITH A STEADY NRLY FLOW PUSHING MARINE LAYER
INLAND/UPSLOPE EARLY THIS MORNING...WILL ASSUME THERE COULD BE SOME
FOG...ESPECIALLY OVER THE HIGHER TERRAIN AS THE COOLER AIR
ENCOUNTERS INITIALLY HIGHER DWPTS.
WHILE A SHRA MAY LINGER OVER THE FAR SCNTRL EARLY THIS EVENING...DRY
WEATHER SHOULD RULE TONIGHT AS SFC HIGH PRES BUILDS S. HOWEVER...IT
IS NOTED THAT SOME OF THE GLOBAL MODELS DO SHOW PCPN BRUSHING THE SW
FCST AREA DURING THE NIGHT...A RESULT OF WEAK WAA OVER SFC COLD
FRONT THAT PASSED TODAY. BASED ON LOCATION OF SFC/850MB FRONTS IN
THOSE MODELS...IT APPEARS PCPN IS BEING GENERATED TOO FAR TO THE NE.
NONETHELESS...IT WILL BE SOMETHING TO KEEP IN MIND FOR LATER
FORECASTS. IT WILL BE A MUCH MORE COMFORTABLE NIGHT FOR SLEEPING AS
TEMPS DROP INTO THE 50S AWAY FROM THE LAKESHORES. DEPENDING ON SKY
COVER...TEMPS IN THE TRADITIONAL COOL SPOTS COULD SLIP INTO THE
UPPER 40S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 512 AM EDT TUE JUL 17 2012
WEDNESDAY THROUGH FRIDAY...AS THE UPPER LEVEL LOW CENTERED OVER
NORTHERN QUEBEC SHIFTS SLOWLY TO THE SOUTHEAST WEDNESDAY...A HIGH
PRESSURE RIDGE ORIENTED FROM NORTH TO SOUTH OVER MANITOBA INTO THE
NORTHERN PLAINS WILL BEGIN TO BUILD EASTWARD INTO MUCH OF THE UPPER
GREAT LAKES REGION THROUGH MUCH OF THE DAY FRIDAY. THIS WILL ALLOW A
SURFACE RIDGE OVER CENTRAL CANADA TO EXPAND SOUTH AND EASTWARD
ENCOMPASSING MUCH OF THE GREAT LAKES REGION THROUGH FRIDAY
AFTERNOON. THE HIGH PRESSURE RIDGE ALONG WITH LITTLE MOISTURE SHOULD
HELP KEEP MOST OF THE UPPER PENINSULA DRY THROUGH THIS TIME PERIOD
WITH THE EXCEPTION OF WEDNESDAY NIGHT INTO EARLY THURSDAY ALONG THE
WISCONSIN BORDER AS MANY OF THE MODELS BRING A SHORTWAVE THROUGH THE
AREA AROUND THIS TIME. AS PREVIOUS SHIFT MENTIONED COOLEST
TEMPERATURES WILL LIKELY BE WEDNESDAY AS THE HIGHER HEIGHTS
ASSOCIATED WITH THE RIDGE SHOULD HOLD OFF UNTIL LATER IN THE
WEEK...ALLOWING FOR A GRADUAL WARMING TREND THURSDAY AND
FRIDAY...BEFORE WARMING MORE RAPIDLY OVER THE WEEKEND.
FRIDAY NIGHT THROUGH MONDAY...AS UPPER LEVEL TROUGHING BEGINS TO
MOVE INTO THE PACIFIC NORTHWEST THROUGH FRIDAY AFTERNOON...EXPECT
THE UPPER LEVEL RIDGE SHOWN AT H500 TO INTENSIFY. THIS SHOULD HELP
TO INCREASE TEMPERATURES ACROSS THE REGION THROUGH THE WEEKEND INTO
THE FIRST PART OF NEXT WEEK. AT THIS POINT THE WARMEST TEMPERATURES
WILL LIKELY MOVE INTO THE REGION OVER THE WEEKEND WITH TEMPERATURES
APPROACHING OR EXCEEDING THE 90 DEGREE MARK. BY MONDAY THE GFS AND
EC ARE IN AGREEMENT THAT THE UPPER LEVEL TROUGH OVER THE PACIFIC
NORTHWEST WILL SHIFT TO NORTHERN MANITOBA...WHICH SHOULD HELP TO
WEAKEN THE RIDGE THROUGH OUT THE DAY...KEEPING TEMPERATURES SLIGHTLY
COOLER. THERE ARE A FEW CHANCES OF SHOWERS AND THUNDERSTORMS THROUGH
THIS PERIOD AS SEVERAL SHORT WAVES ROTATE AROUND THE RIDGE. THE BEST
CHANCE OF PRECIPITATION WOULD LIKELY BE FRIDAY NIGHT INTO SATURDAY
AS ONE OF THE WAVES PASS THROUGH AND THEN AGAIN SUNDAY NIGHT INTO
EARLY MONDAY AS THE NEXT WAVE AN ASSOCIATED WEAK COLD FRONT MOVE
INTO THE AREA. ONE LIMITING FACTOR FOR EACH SHORTWAVE WILL LIKELY BE
THE LACK OF MOISTURE AVAILABLE. WINDS SHOULD REMAIN FAIRLY WEAK AND
A MAJORITY OF THE ISOBARS ARE CLOSED TO THE GULF...WHICH INDICATES A
REDUCTION IN THE AMOUNT OF MOISTURE TRANSPORT INTO THE REGION. AN
ADDITIONAL LIMITING FACTOR FOR THE SHORTWAVE MOVING INTO THE REGION
SUNDAY NIGHT INTO MONDAY WILL BE THE PRESENCE OF A LARGE CAP WITH
H850 TEMPS PROGGED TO BE AOA 21 DEGREES CELSIUS...SO ANY STORM
DEVELOPMENT MAY BE CONFINED ALONG THE COLD FRONT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 735 AM EDT TUE JUL 17 2012
MOIST UPSLOPE FLOW OFF LAKE SUPERIOR IN THE WAKE OF COLD FRONT WILL
CONTINUE TO RESULT IN IFR/LIFR CIGS FOR THE NEXT SEVERAL HRS AT
KIWD/KCMX/KSAW. WITH MORE DIRECT UPSLOPE FLOW...THE LWR LIFR CIGS
WILL PREVAIL AT KIWD/KSAW. VIS RESTRICTION IN FOG WILL ALSO OCCUR AT
KIWD/KSAW. AS DRIER AIR MAKES INROADS WITH FLOW BECOMING MORE
ANTICYCLONIC...IMPROVEMENT EXPECTED BY THE AFTN (BEGINNING FIRST AT
KCMX) WITH VFR CONDITIONS FROM EARLY AFTN THRU THE END OF THE FCST
PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 512 AM EDT TUE JUL 17 2012
FOG HAD BEEN AN ISSUE OVER THE LAST COUPLE OF DAYS. HOWEVER...BASED
ON A FEW SHIP OBS OVERNIGHT...IT APPEARS FOG HAS EITHER DISSIPATED
OR COVERAGE HAS BECOME PATCHY. WILL KEEP A MENTION OF PATCHY FOG IN
THE MORNING. OTHERWISE...AN EXTENDED PERIOD OF GOOD VIS IS SETTING
UP AS DRIER AIR WORKS INTO THE AREA FOR SEVERAL DAYS.
AS FOR WINDS...WITH HIGH PRES BUILDING S TOWARD THE UPPER LAKES
TODAY AND THEN DOMINATING THE AREA THRU FRI...WINDS WILL BE ON THE
LIGHT SIDE. THE STRONGEST WINDS (UP AROUND 15KT) WILL OCCUR TODAY AS
THE HIGH BUILDS S TOWARD THE AREA. LOCALLY HIGHER WINDS...AGAIN UP
AROUND 15KT...WILL OCCUR WED OVER THE W AND ALSO OVER THE FAR ERN
PORTION OF THE LAKE AS MESO HIGH DEVELOPS OVER CNTRL LAKE SUPERIOR.
WINDS THU/FRI SHOULD BE 10KT OR LESS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SHORT TERM...ROLFSON
LONG TERM...KEC
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
736 AM EDT TUE JUL 17 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 512 AM EDT TUE JUL 17 2012
MAIN FCST CONCERN IN THE SHORT TERM WILL BE PCPN CHANCES. WATER
VAPOR IMAGERY AND RUC ANALYSIS SHOW CNTRL CONUS RIDGE LOSING SOME
AMPLITUDE AS A BROAD TROF SETTLES INTO SE CANADA. ALTHOUGH COLD
FRONT ASSOCIATED WITH SE CANADA TROF IS DROPPING S THRU UPPER
MI...VERY LITTLE CONVECTION HAS OCCURRED IN THE VCNTY OF IT. LITTLE
FORCING IN THE PRESENCE OF WARM MID LEVEL TEMPS PER 00Z KINL/KGRB
SOUNDINGS HAS BEEN WORKING AGAINST SHRA/TSRA DEVELOPMENT SO FAR.
SOUTHWARD MOVING COLD FRONT SHOULD HAVE CLEARED ALL OF THE FCST AREA
AT 12Z THIS MORNING...EXCEPT THE FAR SCNTRL AROUND KMNN. WITH FRONT
CONTINUING TO SETTLE S TODAY...IT WOULD APPEAR THERE IS LITTLE RISK
OF PCPN. HOWEVER...SUBTLE SHORTWAVE CURRENTLY ASSOCIATED WITH
CONVECTION IN NRN SD WILL BE TRACKING E AND COULD PROVIDE LIFT OVER
THE SFC BOUNDARY...POSSIBLY RESULTING IN SOME SHRA ACROSS THE AREA
THIS MORNING AND THEN ACROSS THE SCNTRL THIS AFTN. POTENTIAL FOR
TSRA WILL BE DIMINISHING WITH TIME AS INSTABILITY WEAKENS PER NAM
MLCAPE PROGS. OTHER ISSUE TODAY IS FOG. QUITE A BIT OF FOG/STRATUS
HAS PLAGUED LAKE SUPERIOR OVER THE LAST COUPLE OF DAYS. THAT MAY
STILL BE THE CASE. UNFORTUNATELY...STRATOCU IS OBSCURING A BETTER
LOOK BELOW ON 11-3.9MICRON SATELLITE IMAGERY. WHETHER OR NOT THERE
IS FOG ON THE LAKE...WITH A STEADY NRLY FLOW PUSHING MARINE LAYER
INLAND/UPSLOPE EARLY THIS MORNING...WILL ASSUME THERE COULD BE SOME
FOG...ESPECIALLY OVER THE HIGHER TERRAIN AS THE COOLER AIR
ENCOUNTERS INITIALLY HIGHER DWPTS.
WHILE A SHRA MAY LINGER OVER THE FAR SCNTRL EARLY THIS EVENING...DRY
WEATHER SHOULD RULE TONIGHT AS SFC HIGH PRES BUILDS S. HOWEVER...IT
IS NOTED THAT SOME OF THE GLOBAL MODELS DO SHOW PCPN BRUSHING THE SW
FCST AREA DURING THE NIGHT...A RESULT OF WEAK WAA OVER SFC COLD
FRONT THAT PASSED TODAY. BASED ON LOCATION OF SFC/850MB FRONTS IN
THOSE MODELS...IT APPEARS PCPN IS BEING GENERATED TOO FAR TO THE NE.
NONETHELESS...IT WILL BE SOMETHING TO KEEP IN MIND FOR LATER
FORECASTS. IT WILL BE A MUCH MORE COMFORTABLE NIGHT FOR SLEEPING AS
TEMPS DROP INTO THE 50S AWAY FROM THE LAKESHORES. DEPENDING ON SKY
COVER...TEMPS IN THE TRADITIONAL COOL SPOTS COULD SLIP INTO THE
UPPER 40S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 512 AM EDT TUE JUL 17 2012
WEDNESDAY THROUGH FRIDAY...AS THE UPPER LEVEL LOW CENTERED OVER
NORTHERN QUEBEC SHIFTS SLOWLY TO THE SOUTHEAST WEDNESDAY...A HIGH
PRESSURE RIDGE ORIENTED FROM NORTH TO SOUTH OVER MANITOBA INTO THE
NORTHERN PLAINS WILL BEGIN TO BUILD EASTWARD INTO MUCH OF THE UPPER
GREAT LAKES REGION THROUGH MUCH OF THE DAY FRIDAY. THIS WILL ALLOW A
SURFACE RIDGE OVER CENTRAL CANADA TO EXPAND SOUTH AND EASTWARD
ENCOMPASSING MUCH OF THE GREAT LAKES REGION THROUGH FRIDAY
AFTERNOON. THE HIGH PRESSURE RIDGE ALONG WITH LITTLE MOISTURE SHOULD
HELP KEEP MOST OF THE UPPER PENINSULA DRY THROUGH THIS TIME PERIOD
WITH THE EXCEPTION OF WEDNESDAY NIGHT INTO EARLY THURSDAY ALONG THE
WISCONSIN BORDER AS MANY OF THE MODELS BRING A SHORTWAVE THROUGH THE
AREA AROUND THIS TIME. AS PREVIOUS SHIFT MENTIONED COOLEST
TEMPERATURES WILL LIKELY BE WEDNESDAY AS THE HIGHER HEIGHTS
ASSOCIATED WITH THE RIDGE SHOULD HOLD OFF UNTIL LATER IN THE
WEEK...ALLOWING FOR A GRADUAL WARMING TREND THURSDAY AND
FRIDAY...BEFORE WARMING MORE RAPIDLY OVER THE WEEKEND.
FRIDAY NIGHT THROUGH MONDAY...AS UPPER LEVEL TROUGHING BEGINS TO
MOVE INTO THE PACIFIC NORTHWEST THROUGH FRIDAY AFTERNOON...EXPECT
THE UPPER LEVEL RIDGE SHOWN AT H500 TO INTENSIFY. THIS SHOULD HELP
TO INCREASE TEMPERATURES ACROSS THE REGION THROUGH THE WEEKEND INTO
THE FIRST PART OF NEXT WEEK. AT THIS POINT THE WARMEST TEMPERATURES
WILL LIKELY MOVE INTO THE REGION OVER THE WEEKEND WITH TEMPERATURES
APPROACHING OR EXCEEDING THE 90 DEGREE MARK. BY MONDAY THE GFS AND
EC ARE IN AGREEMENT THAT THE UPPER LEVEL TROUGH OVER THE PACIFIC
NORTHWEST WILL SHIFT TO NORTHERN MANITOBA...WHICH SHOULD HELP TO
WEAKEN THE RIDGE THROUGH OUT THE DAY...KEEPING TEMPERATURES SLIGHTLY
COOLER. THERE ARE A FEW CHANCES OF SHOWERS AND THUNDERSTORMS THROUGH
THIS PERIOD AS SEVERAL SHORT WAVES ROTATE AROUND THE RIDGE. THE BEST
CHANCE OF PRECIPITATION WOULD LIKELY BE FRIDAY NIGHT INTO SATURDAY
AS ONE OF THE WAVES PASS THROUGH AND THEN AGAIN SUNDAY NIGHT INTO
EARLY MONDAY AS THE NEXT WAVE AN ASSOCIATED WEAK COLD FRONT MOVE
INTO THE AREA. ONE LIMITING FACTOR FOR EACH SHORTWAVE WILL LIKELY BE
THE LACK OF MOISTURE AVAILABLE. WINDS SHOULD REMAIN FAIRLY WEAK AND
A MAJORITY OF THE ISOBARS ARE CLOSED TO THE GULF...WHICH INDICATES A
REDUCTION IN THE AMOUNT OF MOISTURE TRANSPORT INTO THE REGION. AN
ADDITIONAL LIMITING FACTOR FOR THE SHORTWAVE MOVING INTO THE REGION
SUNDAY NIGHT INTO MONDAY WILL BE THE PRESENCE OF A LARGE CAP WITH
H850 TEMPS PROGGED TO BE AOA 21 DEGREES CELSIUS...SO ANY STORM
DEVELOPMENT MAY BE CONFINED ALONG THE COLD FRONT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 735 AM EDT TUE JUL 17 2012
MOIST UPSLOPE FLOW OFF LAKE SUPERIOR IN THE WAKE OF COLD FRONT WILL
CONTINUE TO RESULT IN IFR/LIFR CIGS FOR THE NEXT SEVERAL HRS AT
KIWD/KCMX/KSAW. WITH MORE DIRECT UPSLOPE FLOW...THE LWR LIFR CIGS
WILL PREVAIL AT KIWD/KSAW. VIS RESTRICTION IN FOG WILL ALSO OCCUR AT
KIWD/KSAW. AS DRIER AIR MAKES INROADS WITH FLOW BECOMING MORE
ANTICYCLONIC...IMPROVEMENT EXPECTED BY THE AFTN (BEGINNING FIRST AT
KCMX) WITH VFR CONDITIONS FROM EARLY AFTN THRU THE END OF THE FCST
PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 512 AM EDT TUE JUL 17 2012
FOG HAD BEEN AN ISSUE OVER THE LAST COUPLE OF DAYS. HOWEVER...BASED
ON A FEW SHIP OBS OVERNIGHT...IT APPEARS FOG HAS EITHER DISSIPATED
OR COVERAGE HAS BECOME PATCHY. WILL KEEP A MENTION OF PATCHY FOG IN
THE MORNING. OTHERWISE...AN EXTENDED PERIOD OF GOOD VIS IS SETTING
UP AS DRIER AIR WORKS INTO THE AREA FOR SEVERAL DAYS.
AS FOR WINDS...WITH HIGH PRES BUILDING S TOWARD THE UPPER LAKES
TODAY AND THEN DOMINATING THE AREA THRU FRI...WINDS WILL BE ON THE
LIGHT SIDE. THE STRONGEST WINDS (UP AROUND 15KT) WILL OCCUR TODAY AS
THE HIGH BUILDS S TOWARD THE AREA. LOCALLY HIGHER WINDS...AGAIN UP
AROUND 15KT...WILL OCCUR WED OVER THE W AND ALSO OVER THE FAR ERN
PORTION OF THE LAKE AS MESO HIGH DEVELOPS OVER CNTRL LAKE SUPERIOR.
WINDS THU/FRI SHOULD BE 10KT OR LESS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KEC
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS ALBANY NY
1205 PM EDT TUE JUL 17 2012
.SYNOPSIS...
A HOT AND HUMID AIR MASS WILL LINGER ACROSS THE REGION TODAY. A COLD
FRONT WILL SAG SLOWLY SOUTH FROM THE SAINT LAWRENCE VALLEY THIS
EVENING...REACHING THE MOHAWK VALLEY WEDNESDAY MORNING...AND THE
LONG ISLAND SOUND BY WEDNESDAY EVENING. HIGH PRESSURE WILL BUILD
FROM HUDSON`S VALLEY LATE WEDNESDAY INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
WMFNT AND ITS CLOUDS AND -SHRA/TSTMS HAS MOVED E OF FCA. PATCHY
MID CLOUDS ACROSS S TIER AND VT...WITH CLEARING OVER REST OF FCA.
THE CLOUDS WILL CLEAR THE S AND E PTNS OF FCA 17-18UTC.
WITH FULL SUN FOR SVRL HRS CONVECTIVE POTENTIAL EVOLVES...AND
CURRENT THINKING HAS NOT CHANGED FM EARLIER TDY. WHILE 12UTC ALB
SNDG AND MDL SOUNDINGS ACROSS FCA SHOW SOME CAPPING...BUF 12UTC
SNDG AND MDL SNDGS INDICATE THIS WILL BE GONE PARTICULARLY N HALF
OF BTWN 18-21UTC.
MOST GUID AND MDL SOUNDINGS HAVE 1000-2000 J/KG OF CAPE ACROSS FCA
AND MINIMAL CIN VALUES BY 21UTC...AGAIN PARTICULARLY N. MAIN ISSUE
AT LEAST INTO THE EVENING IS LACK OF LARGE SCALE FORCING. MID AND
UPR JET AXIS AND FAVORABLE QUADS REMAIN WELL N OF FCA...WITH ONLY
MINIMAL INTERACTION ACROSS N TIER THIS AFTN. AS THIS SHIFTS S TNGT
...THE DYNAMICS WILL ALSO SHIFT S....BY NOT UNTIL AFT 03UTC.
IN SPITE OF A LACK OF LARGE SCALE DYNAMIC FORCING THERE`S DIURNAL
HEATING...AND MOST AREAS WILL SEE L/M 90S...ELEVATED TRRN...GRTLKS
LAKE BREEZES...COLD POOLS AND OUTFLOW BOUNDARIES FROM CONVECTION
TO THE N...A WEAK TROF ACROSS THE E GRTLKS...AND LOCAL EFFECTS TO
TRIGGER CONVECTION. H850 HPA JET OF 30-50KTS NOSES INTO FCA
DURING THE AFTN...AND IT COULD BE SUFFICIENT W/ EXPECTED CAPE TO
GET THINGS GOING. ADD PWATS OF 1.50-ALMOST 2.0 TODAY.
ON THE LARGER SCALE SFC LOW IN OTTAWA VALLEY WILL ZIP EAST TO
MAINE BY EVENING...AND ITS TRAILING CDFNT WILL START TO SAG INTO
N TIER OF NYS BY 00UTC...REACHING THE MHWK VLY BY WED MORNING.
MOST OF LARGE SCALE AND LOCAL MESO SCALE WRF AND HRRR MODELS HV
CONVECTION FIRING ALONG AND AHEAD OF THE CDFNT DURING THE MID AFTN
NR CANADIAN/USA BORDER...AND SHIFTING TO N TIER OF FCA 21-23UTC.
ALL THESE MODELS MAINTAIN THIS CONVECTION INTO THE EVENING AS IT
SHIFTS ESE...POSSIBLY REACHING MHWK VLY/CAP RGN. BUT MODELS WEAKEN
CONVECTION WITH THE END OF DIURNAL HEATING...AND RESURGENCE OF THE
CAP OVERNIGHT. WITH H850 JET PUNCHING EAST....0-6 KM DEEP BULK
SHEAR VALUES ARE ALREADY 40+...MHWK VLY AND N.
SPC HAS OUTLOOKED N HALF OF FCA TODAY. POTENTIAL WATCH DECISION
95% BASED ON LATEST MCD. BUT THE SOUTHERN EXTENT OF SVR CONVECTION
REMAINS QUESTIONABLE.
IN SUMMARY EXPECT A HOT HUMID AFTN. CONVECTION ORGANIZING ALONG N
NY BORDER. APPEARS CURRENT LINE ALONG NVT/N NH IS BACK BUILDING INTO
NYS...AND THIS WILL BCM MORE ORGANIZED NEXT FEW HRS AND SHIFT ESE.
HOW FAR SOUTH REMAINS A QUESTION...BUT N TIER OF FCA REMAINS AT
RISK FOR POSSIBLE SVR. ISOLD-SCT CELLS COULD STILL FORM AFTER CAPS
GIVE WAY THIS AFTN ANYWHERE FM MHWK VLY N AND THESE COULD BCM
QUITE HEALTHY...WITH HEAVY DOWNPOURS.
AS CDFNT SAGS SLOWLY S TNGT IT WILL REMAIN FOCUS OF -SHRA AND
CONVECTION...BUT MDLS CLEARLY SUG CONVECTION WEAKENS CONSIDERABLY
OVERNIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
WEDNESDAY...COMPLICATED CONVECTIVE FORECAST ONCE AGAIN. SPC JUST
CONTINUED THE SLIGHT RISK WHERE THEY LEFT OFF FROM DAY 1.
JUXTAPOSITION OF BEST SHEAR AND CAPE FROM THE ASSORTED GUIDANCE
INDICATES THE LIKELY LOCATIONS FOR A LARGE HAIL AND DAMAGING WIND
THREAT WILL BE SOUTH OF ALBANY...WHERE AN ABUNDANCE OF INSTABILITY
MAY BE IN PLACE WITH SBCAPES OF 1500-3500 J/KG /DUE TO SFC DEWPTS
IN THE L70S/. WE WILL MENTION FROM THE CAPITAL REGION SOUTH IN THE
HWO FOR A SEVERE WEATHER THREAT. LIFTED INDICES ARE IN THE -4C TO
-8C RANGE. ALSO...A SECOND SPEED MAX WILL BE MOVING THROUGH THE
MID AND UPPER JET ALOFT. PORTIONS OF THE ALY FCST AREA WILL BE IN
THE RIGHT REAR QUADRANT OF THE JET STREAK. DEEP ORGANIZED LOOKS
POSSIBLE WITH BULK SHEAR VALUES IN THE 0-6 KM LAYER AROUND 40 KTS
AGAIN.
THE QUESTION WILL BE HOW MUCH HEATING WILL OCCUR WITH CLOUDS
AROUND. IT IS LIKELY SOME ISOLATION WITH OCCURS WITH THUNDERSTORMS
OCCURRING QUICKLY...A MID LEVEL SHORT-WAVE SLICES THROUGH THE
REGION VIA THE GFS/CAN/NAM. THIS ACTUALLY LOOKS LIKE A BETTER CHC
FOR SOME SVR THUNDERSTORMS ON THIS DAY WITH A FEW CLUSTERS OR
LINES. MAX TEMPS WILL RANGE FROM THE U70S AND L80S OVER THE NRN
ZONES...TO THE M80S TO NEAR 90F FROM THE CAPITAL REGION SOUTH. IT
SHOULD ALSO BE EMPHASIZED THAT THE PWATS WILL BE A FEW STANDARD
DEVIATIONS ABOVE NORMAL IN THE 1.50-2.00 INCH RANGE. SOME LOCALLY
HVY DOWNPOURS ARE POSSIBLE...AS SOME LOCATIONS COULD RECEIVE A
QUICK FEW INCHES OF RAINFALL. THE MID LEVEL FLOW IS FAST...SO ANY
CELLS SHOULD BE FAST MOVERS...AND LARGE PCPN DEFICITS CONTINUE
OVER THE HSA. HEAT INDICES REMAINED BELOW ADVISORY CRITERIA OVER
THE MID HUDSON VALLEY...AND NW CT...WITH MAINLY 90S.
WED NIGHT...THE FRONT SLOWLY SAGS SOUTH OF THE AREA...AS COOLER
AND DRIER AIR MOVES INTO THE REGION. WE DIMINISHED THE SHOWERS AND
THUNDERSTORMS AROUND MIDNIGHT FROM ALY SOUTH...AND JUST KEPT A
SLIGHT CHC OF SHOWERS IN OVERNIGHT. HUMIDITY LEVELS WILL LEAVE THE
OPPRESSIVE CATEGORY. LOWS WILL RANGE FROM THE LOWER TO M60S FROM
THE CAPITAL REGION SOUTH AND EAST...AND MAINLY 50S NORTH AND WEST.
THU-THU NIGHT...LOW LEVEL COLD ADVECTION CONTINUES OVER THE FCST
AREA WITH H850 VALUES OF 10C TO 15C FROM THE NW TO SE. A LARGE
DOME OF CANADIAN HIGH PRESSURE BUILDS DOWN FROM JAMES BAY. ASIDE
FROM SOME FAIR WX CUMULUS...IT SHOULD BE A SEASONABLE MID JULY DAY
WITH COMFORTABLE HUMIDITY LEVELS. WE CONTINUED THE DRY WX INTO THU
NIGHT...THOUGH THE NAM TRIES TO RUN A DISTURBANCE CLOSE TO REGION
WITH SOME SHOWERS/TSTMS. WE INCREASED THE CLOUDS OVER THE SRN
TIER...BUT WE DID NOT BUY INTO THIS POSSIBLE CONVECTIVE FEEDBACK
DISTURBANCE. LOWS WILL MAINLY BE IN THE 50S...WITH SOME U40S OVER
THE SRN DACKS...AND GREENS...AND SOME L60S OVER THE MID HUDSON
VALLEY...AND SRN LITCHFIELD CTY.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
MAINLY DRY CONDITIONS WITH TEMPS AVERAGING NEAR NORMAL ARE EXPECTED
DURING THE LONG TERM PERIOD.
A LARGE RIDGE OF HIGH PRESSURE WILL BUILD ACROSS OUR REGION FROM
SOUTHERN CANADA ON FRIDAY AND SETTLE ACROSS OUR REGION ON SATURDAY
BEFORE SLIDING OFF THE EASTERN SEABOARD ON SUNDAY. A COLD FRONT IS
THEN EXPECTED TO DROP SOUTHEAST THROUGH OUR REGION FROM SOUTHERN
CANADA ON MONDAY. HOWEVER IT APPEAR AT THIS TIME THAT VERY LITTLE
MOISTURE EXISTS WITH THIS SYSTEM AND THE FRONTAL PASSAGE MAY OCCUR
WITH LITTLE IF ANY PCPN. H8 TEMPS GENERALLY REMAIN BETWEEN +10 AND
+14C UNTIL SUNDAY AFTERNOON WHEN VALUES RISE TO +15 TO +17 C AS
RETURN FLOW SETS UP WITH HIGH SLIDING OFF THE COAST TO OUR
SOUTHEAST. H8 TEMPS THEN ARE EXPECTED TO START FALLING BY MONDAY
AFTERNOON ACROSS NORTHERN HALF OF FA IN THE WAKE OF THE COLD FRONT.
EXPECT HIGHS ON FRIDAY IN THE 70S TO AROUND 80...MID 70S TO LOWER
80S ON SATURDAY...MAINLY UPPER 70S TO MID 80S ON SUNDAY AND MONDAY.
LOWS ARE EXPECTED TO BE IN THE UPPER 40S TO UPPER 50S FRIDAY
NIGHT...50S TO AROUND 60 SATURDAY NIGHT...AND MID 50S TO MID 60S
SUNDAY NIGHT.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
MID AND HIGH CLOUDS ARE EXPECTED TO GRADUALLY INCREASE ACROSS THE
TAF SITES THROUGH THIS MORNING WITH HOT AND BREEZY CONDITIONS
DEVELOPING BY THIS AFTERNOON. SHOWERS AND THUNDERSTORMS WILL BE
PRIMARILY CONFINED TO FAR NORTHERN AREAS AS WELL AS SOME OF THE
HIGHER TERRAIN. INCREASING SOUTHWEST WINDS ARE EXPECTED TO RESULT IN
DOWNSLOPING IN THE HUDSON VALLEY WHICH SHOULD LIMIT CONVECTIVE
ACTIVITY FOR MOST OF THE TAF SITES. SINCE THE BEST CHANCE OF
THUNDERSTORMS WILL BE AT KGFL LATE THIS AFTERNOON INTO EARLY THIS
EVENING WILL LEAVE PROB 30 IN AT KGFL.
LIGHT AND VARIABLE WINDS WILL BECOME SOUTHWEST BY MID MORNING AND
INCREASE TO 10 TO 15 KTS BY AFTERNOON AND THEN SUBSIDE TO 3 TO 6 KTS
THIS EVENING.
OUTLOOK...
WED...VFR/MVFR. SCT SHOWERS/TSTMS.
THU-SAT...VFR...NO SIG WX.
&&
.FIRE WEATHER...
A HOT AIR MASS WILL BE OVER NEW YORK AND NEW ENGLAND
TODAY. A COLD FRONT WILL APPROACH FROM THE NORTH THIS AFTERNOON AND
EVENING WITH A CHANCE OF SHOWERS AND THUNDERSTORMS MAINLY NORTH AND
WEST OF THE CAPITAL REGION. THE FRONTAL BOUNDARY WILL SLOWLY DRIFT
SOUTH OF THE CAPITAL REGION ON WEDNESDAY WITH MORE SHOWERS AND
THUNDERSTORMS. HIGH PRESSURE WILL BUILD IN ON THURSDAY FROM ONTARIO
AND THE GREAT LAKES REGION WITH DRY WEATHER INTO THE WEEKEND.
RELATIVE HUMIDITY VALUES WILL BE IN THE 25 TO 45 PERCENT RANGE
THIS AFTERNOON...THEN INCREASE TO 85 TO 100 PERCENT TONIGHT.
EXPECT THE RH VALUES TO BE HIGHER ON WEDNESDAY AFTERNOON IN THE 40
TO 55 PERCENT RANGE.
THE WINDS WILL INCREASE FROM THE SOUTHWEST TO WEST AT 10 TO 20 MPH
WITH SOME GUSTS AROUND 25 TO 30 MPH THIS AFTERNOON. THE WINDS WILL BE
LIGHT AND VARIABLE TONIGHT AT 10 MPH OR LESS...AND INCREASE FROM
THE WEST NORTHWEST AT 5 TO 15 MPH ON WEDNESDAY WITH THE FRONTAL
PASSAGE.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED ON THE MAIN STEM RIVERS OVER THE
NEXT 5 DAYS.
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A FRONTAL PASSAGE
TUESDAY THROUGH WEDNESDAY WILL PRODUCE SOME HEAVY RAINFALL DUE TO
A SHORT PERIOD OF ANOMALOUSLY HIGH PRECIPITABLE WATER VALUES IN
THE 1.5 TO 2 INCH RANGE. SOME PONDING OF WATER ON ROADWAYS OR POOR
DRAINAGE FLOODING IS POSSIBLE...ESPECIALLY ON WEDNESDAY. ZONAL
FLASH FLOOD GUIDANCE VALUES REMAIN HIGH FOR MID JULY. THE
POTENTIAL FOR FLASH FLOODING IS LOW AT THIS TIME IN THE ALY HYDRO
SERVICE AREA.
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...SNYDER
NEAR TERM...SNYDER
SHORT TERM...WASULA
LONG TERM...11
AVIATION...11
FIRE WEATHER...WASULA
HYDROLOGY...WASULA
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1131 AM EDT TUE JUL 17 2012
.SYNOPSIS...
A TROUGH OF LOW PRESSURE WILL LINGER OVER INLAND AREAS THROUGH
THURSDAY. A COLD FRONT WILL MOVE INTO THE AREA FRIDAY AND STALL
THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1115 AM TUESDAY...MINOR CHANGES TO PREV FCST. SATL SHOWS SKIES
CLEAR ACROSS MOST OF THE REGION WITH SOME SHRA OFFSHORE AND TO THE
S. AXIS OF BEST PRECIP WTR IS CURRENTLY TO THE SE WITH DRIER AIR TO
THE NW. LOWERED POPS A BIT FOR INLAND AND NRN COUNTIES GIVEN THE
DRIER AIR IN THESE AREAS. ALSO LOWERED INIT SKY COVER GIVEN CLR
SKIES ACROSS THE REGION...SHLD BECOME PC LATER AS CU DEVELOP.
PREV DISC...SOME ISOLATED SHOWERS HAVE DEVELOPED EAST OF WILMINGTON
AND ARE MOVING OFFSHORE INTO OUR FAR SOUTHERN COASTAL WATERS. THESE
SHOWERS SHOULD REMAIN OFFSHORE AND EXPECT GENERALLY DRY CONDITIONS
THRU THE MORNING. UPPER AIR ANALYSIS SHOWS A WEAK EAST-WEST ORIENTED
500 MB TROUGH ACROSS EASTERN NORTH CAROLINA WITH A CLOSED UPPER LOW
OVER NORTHEASTERN FLORIDA. WHILE THE TROUGH GRADUALLY LIFTS
OUT...LEAVING EASTERN NC IN A COL AREA...THERE IS STILL SOME DECENT
MID-LEVEL VORTICITY AROUND DURING THE MID-AFTERNOON HOURS. AT THE
SURFACE A TROUGH LINGERS OVER THE PIEDMONT REGION AS HIGH PRESSURE
WELL OFFSHORE CONTINUES TO PROVIDE WARM...MOISTURE AND UNSTABLE TO
EASTERN NC. BOTH THE RAP AND GFS INDICATE THAT GIVEN MAX
TEMPERATURES INTO THE LOWER 90S AND DEWPOINTS IN THE LOWER AND
MIDDLE 70S LATER THIS AFTERNOON...CAPE VALUES IN EXCESS OF 3000 J/KG
AND LI VALUES OF -6 TO -8 ARE FORECAST. GIVEN THESE FACTORS...THINK
ANOTHER GOOD COVERAGE OF SHOWERS AND TSTMS CAN BE EXPECTED WITH THE
HIGHEST PROBABILITY IN AREAS SIMILAR TO YESTERDAY OVER THE
NORTHWESTERN CWA WITH POPS TAPERING BACK TO MINIMAL NEAR THE
SOUTHERN COASTAL AREA. WILL AGAIN HIGHLIGHT LOCALLY STRONG STORMS IN
THE HAZARDOUS WEATHER OUTLOOK.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
AS OF 340 AM TUESDAY...SHOWERS AND TSTMS WILL ONCE AGAIN DISSIPATE
WITH LOSS OF HEATING AFTER ABOUT 02Z. MINIMUM TEMPERATURES WILL
AGAIN BE BETWEEN 73 AND 78 DEGREES WITH LIKELY SOME LEFTOVER HIGH
DEBRIS CLOUDS FROM ANY CONVECTION THAT DEVELOPS DURING THE
AFTERNOON AND EVENING HOURS.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 330 AM TUE...LONG TERM PERIOD WILL FEATURE THE POTENTIAL FOR
PERIODS OF WIDESPREAD HEAVY RAIN THIS WEEKEND. FOR WED AND THUR...E
NC WILL REMAIN IN TYPICAL SUMMER REGIME WITH ISO-SCT AFTERNOON
THUNDERSTORMS MAINLY ASSOCIATED WITH SEA BREEZE FRONT.
WEAKNESS IN THE MID LEVELS WILL BRING A CHANCE OF DIURNAL CONVECTION
ACROSS INLAND AREAS WED AFTERNOON. SUBTROPICAL MOISTURE WILL STREAM
NORTHEASTWARD OFF THE COAST WED NIGHT...AND WILL BRING SCT
THUNDERSTORMS FOR THE COASTAL WATERS. SOME OF THIS CONVECTION MAY
ADVECT OFF THE OCEAN AND AFFECT THE COASTAL COUNTIES LATE WED NIGHT.
FOR THUR...PIEDMONT THERMAL TROUGH WILL STRENGTHEN SOMEWHAT IN
RESPONSE TO BUILDING CENTRAL CONUS RIDGE AND DIGGING OF EASTERN
CONUS TROUGH. SOMEWHAT BETTER CHANCE FOR MORE ORGANIZED CONVECTION
WELL INLAND NEARER THE THERMAL TROUGH. BOTH GFS AND ECMWF IN FAIRLY
GOOD AGREEMENT WITH THE SYNOPTIC REGIME THROUGH THIS WEEKEND...
THOUGH SOME TIMING DIFFERENCES IN ARRIVAL OF SFC BOUNDARY THAT WILL
SET THE STAGE FOR POSSIBLE PERIODS OF HEAVY RAIN THIS WEEKEND. SIDED
WITH MORE CONSISTENT/SLOWER ECM SOLN...AS THIS HAS SUPPORT FROM ITS
ENSEMBLE MEAN...GEFS ENSEMBLE MEAN SOLN...AND OPERATIONAL 17/00Z
CANADIAN MODEL. THIS SOLN HANGS UP THE EAST-WEST ORIENTED FRONT
THROUGH THE WEEKEND...AND WITH PWATS AROUND 2.25 INCHES OR HIGHER...
COULD BRING THREAT FOR FLOODING. IF THESE PWAT VALS COME TO
FRUITION...THEY WOULD BE NEAR THE 99TH PERCENTILE FOR CLIMATOLOGICAL
VALUES FOR JULY...WHICH COULD CERTAINLY POSE THREAT FOR FLOODING
RAINS. THE UNSETTLED WEATHER MAY LINGER INTO THE BEGINNING OF NEXT
WEEK.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH 00Z WEDNESDAY/...
AS OF 645 AM TUESDAY...AGAIN THIS MORNING...A LIGHT 3 TO 5 KNOT
WIND HAS PREVENTED ANY FOG FORMATION AT THE TAF SITES. WITH A
SURFACE TROUGH INLAND AND SOME WEAK UPPER ENERGY IN PLACE..SCATTERED
TSTMS WILL BE A GOOD POSSIBILITY LATER TODAY...ESPECIALLY AT KPGV
AND PERHAPS AGAIN AT KEWN/KISO.
LONG TERM /TUE NIGHT THROUGH SAT/
AS OF 330 AM TUESDAY...MAINLY VFR CONDITIONS OTHER THAN SOME TEMPO
REDUCTION TO VSBYS/CIGS LATE AT NIGHT/EARLY IN THE MORNING DUE TO
RADIATION FOG/BR. SMALL CHANCES OF AFTERNOON THUNDERSTORMS DUE TO
SEA BREEZE FRONT PROPAGATING INLAND EACH AFTERNOON. BETTER CHANCE
FOR WIDESPREAD RAIN AND THUNDERSTORMS ARRIVES ON FRIDAY AND WILL
LINGER INTO THE WEEKEND...WITH PERIODS OF IFR CONDITIONS POSSIBLE.
&&
.MARINE...
SHORT TERM /THROUGH TUESDAY...
AS OF 1115 AM TUESDAY...NO CHANGES WITH SW WINDS 10 TO 20 KTS AND
SEAS 2 TO 4 FEET...HIGHEST OFFSHORE.
PREV DISC...CURRENT BUOY OBSERVATIONS INDICATING GENERALLY SW WINDS
OF 10 TO 15 KNOTS WITH A GUST TO 18 KNOTS AT DIAMOND BUOY WITH SEAS
AT 2 TO 4 FEET WITH A ROLLING 10 TO 11 SECOND SWELL. THE SAME
PATTERN THAT WE HAVE SEEN OVER THE PAST SEVERAL DAYS WILL CONTINUE.
GRADIENT BETWEEN SURFACE TROUGH OVER THE PIEDMONT REGION AND THE
SEMI-PERMANENT BERMUDA HIGH OFFSHORE WILL LEAD TO STOUTEST WINDS OF
10 TO 15 KNOTS WITH OCCASIONAL GUSTS TO 20 KNOTS. SEAS WILL RUN 2 TO
4 FEET WITH OCCASIONAL 5 FOOT SEAS OVER THE OUTER
WATERS...ESPECIALLY IN THE CENTRAL WATERS.
LONG TERM /TUE NIGHT THROUGH SAT/
AS OF 330 AM TUE...LATEST RUN OF THE MAJOR MODELS IN VERY CLOSE
AGREEMENT THROUGH LATE WEEK. STILL PREFER THE 00Z ECMWF HANDLING OF
THE SOUTHWARD MOVING COOL FRONT THIS WEEKEND...WHICH HANGS UP THE
FRONT OVER EASTERN NC THIS WEEKEND. THE GFS PUSHES THE FRONT TO THE
SOUTH WHICH IS HARD TO DO THIS TIME OF YEAR. SOUTHWEST FLOW
CONTINUES THROUGH FRIDAY. EXPECTING A NORTHEAST FLOW OVER THE
CENTRAL AND NORTHERN WATERS SATURDAY AND SUNDAY NORTH OF THE FRONT
WITH A SOUTHWEST FLOW OVER THE SOUTHERN WATERS. STILL LOOKING AT
SMALL CRAFT SEAS DEVELOPING OVER THE CENTRAL AND SOUTHERN WATERS
LATE WED NIGHT THROUGH FRIDAY NIGHT AHEAD OF THE FRONT. WINDS AND
SEAS SHOULD FALL BELOW SCA THIS WEEKEND WITH FRONT OVERHEAD.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...CTC
NEAR TERM...RF/CTC
SHORT TERM...CTC
LONG TERM...TL
AVIATION...CTC/TL
MARINE...RF/CTC/TL
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
1045 AM CDT TUE JUL 17 2012
.DISCUSSION...
15 UTC SURFACE ANALYSIS SHOWS A LOW PRESSURE CENTER ACROSS SOUTH-
CENTRAL SD AND A WEAK FRONTAL BOUNDARY EXTENDING EASTWARD INTO
SOUTHWEST MN. SHOWERS AND ISOLATED THUNDER HAVE BEEN CONFINED TO
A NARROW CORRIDOR COINCIDENT WITH BEST MID-LEVEL CONVERGENCE ALONG
AND SOUTH OF A LINE FROM MOBRIDGE SD TO WAHPETON TO PARK RAPIDS.
THERE IS A SECONDARY CONVECTIVE CLUSTER ALONG I-94 WEST OF
BISMARCK...MOVING TO THE EAST-NORTHEAST AROUND 20 KTS. NORTHEAST
SURFACE FLOW...COMBINED WITH DRIER MID-LEVELS AND LITTLE TO NO
INSTABILITY SHOULD RESULT IN THESE SHOWERS AND STORMS DISSIPATING
LATER THIS MORNING. AS SUCH...FOCUSED CHANCE POPS LATE THIS
MORNING ACROSS THE SOUTH...DECREASING TO SLIGHT CHANCE THIS
AFTERNOON. LATEST HRRR DOES SUGGEST ACTIVITY FARTHER WEST WILL
HOLD TOGETHER...SO WILL NEED TO MONITOR LATEST OBSERVATIONS AND
ADJUST FORECAST IF PRECIPITATION HOLDS TOGETHER ACROSS EASTERN ND.
WARMEST TEMPERATURES ALOFT ARE ACROSS THE SOUTH TODAY...BUT
SIGNIFICANT CONVECTIVE DEBRIS FROM OVERNIGHT HAS LIMITED
TEMPERATURE RISE THIS MORNING. AREAS FARTHER NORTH WILL SEE MORE
SUN...BUT COOLER TEMPERATURES ALOFT. ALL SAID...HIGHS THIS
AFTERNOON WILL BE A BALANCE BETWEEN CLOUD COVER AND BOUNDARY LAYER
THERMAL PROFILE...MAXING OUT IN THE UPPER 70S TO LOWER 80S. DID
DECREASE A DEGREE OR TWO ACROSS THE SOUTH WHERE PREVIOUS FORECAST
CURVE WAS RISING TOO FAST.
&&
.AVIATION...
PATCHY MVFR CIGS LIKELY TO SCATTER OUT THIS AFTERNOON AS SOME DRYING
IN THE LOWER LEVELS TAKES HOLD. TSRA TO BE CONFINED TO AREAS ALONG
ND/SD/MN BORDER AREA.
&&
.PREV DISCUSSION... /ISSUED 345 AM CDT TUE JUL 17 2012/
DISCUSSION...FORECAST CHALLENGE CONCERNS MAINLY SHORT TERM PCPN
CHANCES...TEMPERATURES AND NEAR TERM AVIATION/CLOUD TRENDS. MODELS
IN GOOD AGREEMENT WITH MAIN FEATURES WITH GFS ACTUALLY DOING BEST
WITH LOW LEVEL MOISTURE FIELDS. WILL USE BLEND FOR FORECAST
CHALLENGE.
CURRENT CONVECTION ORIENTED ALONG ND/SD BORDER AREA VCNTY ELEVATED
BOUNDARY IN MOIST AXIS WITH SUPPORT FROM ENTRANCE REGION OF UPPER
JET MAXIMA. FAVORED CONVECTIVE PARAMETERS REMAIN ACROSS NE SD TO
SD/ND BORDER AREA THROUGH THE MORNING. WITH JET MAXIMA SHIFTING EAST
THIS MORNING WOULD EXPECT CONVECTION TO GRADUALLY DIMINISH. WILL
MONITOR TRENDS FOR MORNING POPS HOWEVER WILL LIKELY CONFINE ANY POPS
TO ALONG AND SOUTH OF I94 CORRIDOR. FOR TEMPERATURES PATCHY MVFR
CIGS BECOMING MASKED BY UPPER LEVEL CONVECTIVE DEBRIS CLOUDS. COLUMN
CONTINUES TO COOL SLIGHTLY TODAY IN WAKE OF BOUNDARY PASSAGE. GFS
HINTS AT SOME DRYING IN LOWER LEVELS SO FEEL THERE WILL AT THE LEAST
BE SOME PARTIAL SUNSHINE. WARMEST AIR ACROSS THE SOUTH HOWEVER
CLOUDS LIKELY TO STICK AROUND LONGER WITH CURRENT CONVECTION.
OVERALL LOOKING AT COOLER MORE SEASONAL TEMPERATURES TODAY.
SURFACE AND ELEVATED BOUNDARY MOVES VERY LITTLE OVER THE NEXT 24-36
HOURS. ALONG WITH DAY TIME HEATING MODELS HINTING AT ANOTHER
WEAK WEAK IMPULSE TO INTERACT WITH NEAR STATIONARY BOUNDARY FOR MORE
CONVECTIVE DEVELOPMENT ACROSS NORTHERN HIGH PLAINS THIS AFTERNOON.
THIS CONVECTION LIKELY TO PROPAGATE ALONG ND/SD BORDER AGAIN LATER
TONIGHT ALONG LOW LEVEL MOISTURE AXIS. AT THIS POINT WILL HOLD OFF
ANY ANY SEVERE MENTION ALTHOUGH ANY CHANCES LIKELY CONFINED TO
BORDER AREA. FARTHER NORTH EASTERLY FLOW/UPSLOPE WILL LIMIT ANY
PCPN CHANCES TO FAR WESTERN FA AT BEST. ALTHOUGH CONFIDENCE LOW WILL
INTRODUCE SLIGHT CHANCE POPS TO FAR WEST WITH BETTER CHANCES
CONTINUING ALONG ND/SD/MN BORDER AREA. MORE COMFORTABLE MINIMUM
TEMPERATURES WILL CONTINUE ACROSS MOST AREAS.
COULD SEE SOME LINGERING CONVECTION ACROSS FAR SOUTH WEDNESDAY AM
AND WILL INTRODUCE LOW POPS TO THIS AREA. REMAINDER LIKELY TO REMAIN
DRY AND AM HESITANT TO SPREAD POPS FURTHER WEST AND NORTH WITH
CURRENT DRY CONDITIONS AND DRIER EASTERLY FLOW. TEMPERATURES AGAIN
LOOK TO BE AT OR A LITTLE BLO SEASONAL AVERAGES.
HEIGHTS BUILD LATER IN THE WORK WEEK WITH INCREASING SOUTHERLY FLOW
AND WARM ADVECTION. THIS WILL ALLOW TEMPERATURES TO RECOVER BACK
ABOVE AVERAGE. WITH LACK OF ANY LOW LEVEL CONVERGENCE AND LOW LEVEL
JET CONVERGENCE WELL TO OUR WEST AND PCPN CHANCES LOOK MINIMAL. AT
THIS POINT WILL STAY CONSISTENT AND LEAVE POPS AS IS AS CONDITIONS
OVERALL LOOK DRY.
LONG TERM (FRI-MON)...
MODELS IN GOOD AGREEMENT WITH THE EXTENDED PERIOD WITH WRT 500MB
FLOW. RIDGING CONTINUES TO BUILD INTO THE NORTHERN PLAINS FRIDAY
WITH THE THERMAL AXIS TO MOVE OVER THE CWFA ON SATURDAY. SLGT CHC
POPS CONTINUE AS CONVECTION IS POSSIBLE AS COMPLEXES RIDE THE RIDGE
ON THE EDGE OF THE CAP...THOUGH WIDE SPREAD RAINFALL IS NOT
EXPECTED. UPPER 80 ANS LOW 90S ON FRI AND SAT. WIND SHIFT SATURDAY
NIGHT WILL ALLOW TEMPS TO RETURN TO NEAR MID SUMMER NORMALS FOR THE
BEGINNING OF THE WEEK..
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
ROGERS/WJB/VOELKER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
937 AM CDT TUE JUL 17 2012
.DISCUSSION...BOWMAN RADAR THIS MORNING DEPICTING A MID LEVEL
SHORTWAVE SPINNING NEAR KDIK WHICH IS MOVING NORTHEAST WITH TIME.
AN AREA OF SHOWERS AND ISOLATED THUNDERSTORMS ASSOCIATED WITH THIS
DISTURBANCE WILL CONTINUE TO MIGRATE NORTHEAST THROUGH 18Z AND
HAVE INCREASED POPS ACROSS NORTH CENTRAL NORTH DAKOTA...WHICH IS
WHAT THE HRRR MODEL IS ALSO IMPLYING. SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS SHOULD SUFFICE TO COVER THIS SHORTWAVE.
THE WEST/SOUTHWEST/AND FAR SOUTH CENTRAL IS UNDER A SLIGHT RISK
FOR SEVERE WEATHER THIS AFTERNOON AND TONIGHT. THE HRRR IS SUGGESTING
AN AREA OF THUNDERSTORMS DEVELOPING OVER SOUTHWEST NORTH DAKOTA
EARLY THIS AFTERNOON AND THEN PROGRESSING EAST. LATEST VISIBLE
IMAGERY ALREADY SHOWING SOME CLEARING IN THE SOUTHWEST AND WILL
NEED TO WATCH THIS AREA BY 18Z. THE HRRR/GFS SHOW MORE
THUNDERSTORMS DEVELOPING OVER EASTERN MONTANA THIS EVENING AND THIS
SHOULD BE THE MAIN ACTION WITH THE UPPER SHORTWAVE THAT ROLLS
THROUGH TONIGHT. FOR TONIGHT...A POSSIBLE MCS COULD DEVELOP PER
SPC OVER SOUTH DAKOTA OR SOUTHERN NORTH DAKOTA. HEAVY RAIN/LARGE
HAIL AND/OR DAMAGING WINDS WILL BE THE MAIN THREATS. WILL FOCUS ON
THIS DURING THE AFTERNOON AND EVENING UPDATES.
&&
.AVIATION...AT 930 AM CDT...A STATIONARY FRONTAL BOUNDARY EXTENDED
EAST-WEST ACROSS SOUTH DAKOTA...THEN EXTENDED FROM NORTHWESTERN
SOUTH DAKOTA ACROSS EASTERN MONTANA INTO SOUTHERN SASKATCHEWAN. THE
FRONT ACROSS SOUTH DAKOTA WILL BE THE FOCUS FOR THUNDERSTORMS ACROSS
THE SOUTHERN THIRD OF NORTH DAKOTA THIS MORNING. A MOIST EAST TO
NORTHEASTERLY LOW LEVEL FLOW ACROSS NORTH DAKOTA WAS BRINGING MVFR
TO OCNL IFR CONDITIONS. HAZARDS TO AVIATION TODAY INCLUDE MVFR TO
OCNL IFR CONDITIONS INCLUDING KISN/KMOT/KJMS/KBIS/KDIK THROUGH 18Z
TUESDAY. THUNDERSTORMS WILL CONTINUE TO FORM AND TRACK ACROSS THE
SOUTHERN THIRD OF THE STATE AS WELL AS FAR WESTERN NORTH DAKOTA.
THIS SHOULD IMPACT KISN/KDIK/KBIS/KJMS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KS
AVIATION...JV
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
957 AM EDT TUE JUL 17 2012
.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL UNTIL WEDNESDAY...WITH HOT DAYS AND
MUGGY NIGHTS ACROSS THE LOWLANDS. A COLD FRONT SINKS SOUTHEAST
ON THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM UPDATE...DID ELECT TO ADD AT LEAST A SLIGHT CHANCE OF POPS
CWA WIDE THIS AFTERNOON. IN THE MOIST...HUMID...ATMOSPHERE...DONT
FEEL CAN TOTALLY RULE IT OUT DURING PEAK DAYTIME HEATING. IN
ADDITION...NAM SUGGESTING UPPER AIR DISTURBANCES ROUNDING RIDGE
COULD TRIGGER STORMS IN THE EASTERN PARTS OF CWA...ALTHOUGH GREATER
CHANCES EXIST WEST OF THE CWA. ALSO DID BUMP UP MAX TEMPS A DEGREE OR
SO IN A FEW LOCATIONS FOR TODAY BASED ON THE FACT THAT WE ARE
ALREADY SEVERAL DEGREES WARMER IN MANY LOCATIONS THAT THE CURRENT
GUIDANCE WOULD SUGGEST...AND WITH A LACK OF CLOUD COVER THIS
AM...SHOULD GET SOME DECENT HEATING GOING. CURRENT HEAT ADVISORY
LOCATION LOOKS GOOD.
PREVIOUS DISCUSSION FOLLOWS...
HOT AND HUMID AIRMASS MOVING INTO REGION...AS AN UPPER LEVEL
RIDGE BROADENS OVER FORECAST AREA TODAY. WITH ABUNDANT LOW LEVEL
MOISTURE AND GOOD DAYTIME HEATING...EXPECTING ISOLATED CONVECTION
TODAY. NAM DOES KEEP THE BULK OF IT WEST OF THE FORECAST AREA...IN
CENTRAL KY...TIED TO AN UPPER LEVEL DISTURBANCE SLIDING SOUTH
THERE. GFS PAINTS A LITTLE MORE PRECIP INTO THE FORECAST AREA THIS
AFTERNOON...AND RAP SOUNDINGS SHOW MODEST INSTABILITY...SO
EXPANDED THE AREAL COVERAGE OF THE SLIGHT CHANCE POPS A BIT FOR
THIS AFTERNOON...BUT STILL THINK THINGS SHOULD BE MOSTLY ISOLATED.
MODEL GUIDANCE FOR AFTERNOON HIGHS GENERALLY A BIT WARMER THAN
PREVIOUS FORECAST...SO BUMPED UP HIGHS A BIT. COMBINED WITH
DEWPOINTS CLIMBING INTO THE 70S...THIS PRODUCED HEAT INDEX VALUES
AROUND TO JUST ABOVE 100 DEGREES ALONG AND WEST OF THE OHIO RIVER.
ISSUED HEAT ADVISORY FOR THESE AREAS. EXPECTING A MUGGY NIGHT
TONIGHT WITH TEMPS ONLY DROPPING INTO THE LOW 70S ACROSS MUCH OF THE
LOWLANDS. MOST GUIDANCE VERY CLOSE FOR LOWS TONIGHT...SO BLENDED IN
NEW 00Z MOS.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
5H RIDGE IN PLACE AS TROUGH SAGS ACROSS EASTERN CANADA THROUGH THE
PERIOD. BAROCLINIC ZONE WILL BE DRAPED ACROSS THE GREAT LAKES AND
WILL SLOWLY NUDGE SOUTHWARD WITH TIME. THIS LEADS TO MOISTENING AND
DESTABILIZATION OF THE ATMOSPHERIC COLUMN LATE WEDNESDAY NIGHT INTO
THURSDAY. THUS HAVE NUDGED POP VALUES HIGHER TO ACCOUNT FOR INCREASE
IN MOISTURE.
MODELS GENERALLY AGREE WITH IDEA OF SLOWLY TRANSITIONING THE FRONT
INTO CWA WED NIGHT...WITH BOUNDARY STAYING TO OUR SOUTH INTO
FRIDAY. THIS SHOULD LEAD TO A PERIOD OF UNSETTLED WEATHER...
ESPECIALLY IN THE AFTERNOON WHEN BOUNDARY LAYER HEATING IS
MAXIMIZED. FOR TEMPS...USED MAINLY INHERITED VALUES WITH MINOR
CHANGES BASED ON LATEST MOS GUIDANCE.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
DRIER AIR WILL MOVE INTO THE CWA FOR FRIDAY BEHIND THE FRONT...WITH
A NORTHWESTERLY FLOW PATTERN ALOFT SETTING UP ACROSS THE CWA...AND
COOLER WEATHER TAKING HOLD. STILL LOOKING AT A CHANCE FOR SHOWERS
AND THUNDERSTORMS IN THE EXTENDED AS WEAK RIPPLES IN THE FLOW WILL
KEEP A MENTION...ESPECIALLY DOWN SOUTH WHERE BETTER MOISTURE WILL
EXIST. TEMPERATURES WILL BEGIN TO WARM BY THE WEEKEND AS HIGH OVER
CENTRAL U.S. BUILDS EAST.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
SOME PATCHES OF MAINLY MVFR FOG FLOATING AROUND THE FORECAST AREA
THIS MORNING...EXPECTING THINGS RETURN TO VFR SHORTLY AND REMAIN
THERE FOR BULK OF THE DAY. HOWEVER...WITH LOTS OF LOW LEVEL
MOISTURE...EXPECT ISOLATED DIURNAL CONVECTION ON THIS
AFTERNOON...WHICH COULD BRING ABOUT SOME BRIEF PERIODS OF MVFR IN
THE HEAVIEST SHOWERS. EXPECTING ENOUGH WIND AND INCOMING CLOUDS TO
PRECLUDE MUCH FOG WEDNESDAY MORNING...HOWEVER KEKN WILL BE THE
LAST TO SEE THE INCOMING CLOUDS SO PUT IN SOME IFR FOG THERE.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: TIMING AND DENSITY OF FOG DISSIPATION MAY
VARY THIS MORNING. IF CLOUDS SLOWER TO ENTER AREA TONIGHT...COULD
SEE MORE WIDESPREAD FOG DEVELOP.
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.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z WEDNESDAY...
MORE WIDESPREAD CONVECTION EXPECTED WEDNESDAY AFTERNOON AND
WEDNESDAY NIGHT...WITH IFR IN HEAVIER SHOWERS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR WVZ005>011-014.
OH...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR OHZ066-067-075-
076-083>087.
KY...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR KYZ101-103.
VA...NONE.
&&
$$
SYNOPSIS...MZ
NEAR TERM...MZ/SL
SHORT TERM...KMC
LONG TERM...SL
AVIATION...MZ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
646 AM EDT TUE JUL 17 2012
.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL UNTIL WEDNESDAY...WITH HOT DAYS AND
MUGGY NIGHTS ACROSS THE LOWLANDS. A COLD FRONT SINKS SOUTHEAST
ON THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
HOT AND HUMID AIRMASS MOVING INTO REGION...AS AN UPPER LEVEL
RIDGE BROADENS OVER FORECAST AREA TODAY. WITH ABUNDANT LOW LEVEL
MOISTURE AND GOOD DAYTIME HEATING...EXPECTING ISOLATED CONVECTION
TODAY. NAM DOES KEEP THE BULK OF IT WEST OF THE FORECAST AREA...IN
CENTRAL KY...TIED TO AN UPPER LEVEL DISTURBANCE SLIDING SOUTH
THERE. GFS PAINTS A LITTLE MORE PRECIP INTO THE FORECAST AREA THIS
AFTERNOON...AND RAP SOUNDINGS SHOW MODEST INSTABILITY...SO
EXPANDED THE AREAL COVERAGE OF THE SLIGHT CHANCE POPS A BIT FOR
THIS AFTERNOON...BUT STILL THINK THINGS SHOULD BE MOSTLY ISOLATED.
MODEL GUIDANCE FOR AFTERNOON HIGHS GENERALLY A BIT WARMER THAN
PREVIOUS FORECAST...SO BUMPED UP HIGHS A BIT. COMBINED WITH
DEWPOINTS CLIMBING INTO THE 70S...THIS PRODUCED HEAT INDEX VALUES
AROUND TO JUST ABOVE 100 DEGREES ALONG AND WEST OF THE OHIO RIVER.
ISSUED HEAT ADVISORY FOR THESE AREAS. EXPECTING A MUGGY NIGHT
TONIGHT WITH TEMPS ONLY DROPPING INTO THE LOW 70S ACROSS MUCH OF THE
LOWLANDS. MOST GUIDANCE VERY CLOSE FOR LOWS TONIGHT...SO BLENDED IN
NEW 00Z MOS.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
5H RIDGE IN PLACE AS TROUGH SAGS ACROSS EASTERN CANADA THROUGH THE
PERIOD. BAROCLINIC ZONE WILL BE DRAPED ACROSS THE GREAT LAKES AND
WILL SLOWLY NUDGE SOUTHWARD WITH TIME. THIS LEADS TO MOISTENING AND
DESTABILIZATION OF THE ATMOSPHERIC COLUMN LATE WEDNESDAY NIGHT INTO
THURSDAY. THUS HAVE NUDGED POP VALUES HIGHER TO ACCOUNT FOR INCREASE
IN MOISTURE.
MODELS GENERALLY AGREE WITH IDEA OF SLOWLY TRANSITIONING THE FRONT
INTO CWA WED NIGHT...WITH BOUNDARY STAYING TO OUR SOUTH INTO
FRIDAY. THIS SHOULD LEAD TO A PERIOD OF UNSETTLED WEATHER...
ESPECIALLY IN THE AFTERNOON WHEN BOUNDARY LAYER HEATING IS
MAXIMIZED. FOR TEMPS...USED MAINLY INHERITED VALUES WITH MINOR
CHANGES BASED ON LATEST MOS GUIDANCE.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
DRIER AIR WILL MOVE INTO THE CWA FOR FRIDAY BEHIND THE FRONT...WITH
A NORTHWESTERLY FLOW PATTERN ALOFT SETTING UP ACROSS THE CWA...AND
COOLER WEATHER TAKING HOLD. STILL LOOKING AT A CHANCE FOR SHOWERS
AND THUNDERSTORMS IN THE EXTENDED AS WEAK RIPPLES IN THE FLOW WILL
KEEP A MENTION...ESPECIALLY DOWN SOUTH WHERE BETTER MOISTURE WILL
EXIST. TEMPERATURES WILL BEGIN TO WARM BY THE WEEKEND AS HIGH OVER
CENTRAL U.S. BUILDS EAST.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
SOME PATCHES OF MAINLY MVFR FOG FLOATING AROUND THE FORECAST AREA
THIS MORNING...EXPECTING THINGS RETURN TO VFR SHORTLY AND REMAIN
THERE FOR BULK OF THE DAY. HOWEVER...WITH LOTS OF LOW LEVEL
MOISTURE...EXPECT ISOLATED DIURNAL CONVECTION ON THIS
AFTERNOON...WHICH COULD BRING ABOUT SOME BRIEF PERIODS OF MVFR IN
THE HEAVIEST SHOWERS. EXPECTING ENOUGH WIND AND INCOMING CLOUDS TO
PRECLUDE MUCH FOG WEDNESDAY MORNING...HOWEVER KEKN WILL BE THE
LAST TO SEE THE INCOMING CLOUDS SO PUT IN SOME IFR FOG THERE.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: TIMING AND DENSITY OF FOG DISSIPATION MAY
VARY THIS MORNING. IF CLOUDS SLOWER TO ENTER AREA TONIGHT...COULD
SEE MORE WIDESPREAD FOG DEVELOP.
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.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EDT 1HRLY 07 08 09 10 11 12 13 14 15 16 17 18
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY L L L H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z WEDNESDAY...
MORE WIDESPREAD CONVECTION EXPECTED WEDNESDAY AFTERNOON AND
WEDNESDAY NIGHT...WITH IFR IN HEAVIER SHOWERS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
WVZ005>011-014.
OH...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
OHZ066-067-075-076-083>087.
KY...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
KYZ101-103.
VA...NONE.
&&
$$
SYNOPSIS...MZ
NEAR TERM...MZ
SHORT TERM...KMC
LONG TERM...SL
AVIATION...MZ
AREA FORECAST DISCUSSION
NWS PUEBLO CO
317 PM MDT TUE JUL 17 2012
.SHORT TERM...
(TONIGHT AND WEDNESDAY)
CURRENT WATER VAPOR IMAGERY TELLING THE STORY WITH MUCH DRIER AIR
ACROSS WESTERN COLORADO MOVING INTO CENTRAL AND EASTERN COLORADO
ALONG WITH SUBSIDENCE ASSOCIATED WITH UPPER LEVEL RIDGING ACROSS THE
SOUTHERN HIGH PLAINS AND SOUTHERN ROCKIES BUILDING INTO THE CENTRAL
ROCKIES...HAS HELPED TO TAME CONVECTION ACROSS THE AREA THROUGH THE
EARLY AFTERNOON. REGIONAL RADARS STILL INDICATING ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE HIGHER TERRAIN...WITH
THE BEST COVERAGE ACROSS THE SOUTHWEST AND CENTRAL MTS AT THIS TIME.
RADAR DATA ALSO INDICATING A FEW CELLS POPPING ACROSS KIOWA COUNTY AT
THIS TIME. SATELLITE AND VISUAL INSPECTION INDICATING CU ACROSS THE
EASTERN MTS SHOWING MORE VERTICAL DEVELOPMENT AS WELL. AT THE
SFC...WEAK FRONTAL BOUNDARY HAS PUSHED THROUGH ALL OF THE SOUTHEAST
PLAINS WITH LATEST DATA INDICATING LOWER PRESSURES ACROSS THE LEE OF
THE ROCKIES AT THIS TIME.
TONIGHT...WITH A FEW MORE HOURS OF HEATING ALONG WITH WINDS BECOMING
MORE UPSLOPE ACROSS THE EASTERN PLAINS...SHOULD CONTINUE TO SEE
ISOLATED TO SCATTERED STORMS FIRING ACROSS THE HIGHER TERRAIN
THROUGH THE EARLY EVENING...WITH A FEW STORMS FIRING ACROSS THE
IMMEDIATE ADJACENT PLAINS THROUGH THE FAR SE PLAINS. LATEST HIGHER
RESOLUTION HRRR MODEL CONTINUES TO INDICATE SCATTERED STORMS FIRING
ACROSS THE PIKES PEAK REGION THROUGH THE EARLY EVENING WITH THE
DEVELOPING LOW LEVEL UPSLOPE. THIS STILL POSES A THREAT FOR LOCALLY
HEAVY RAINFALL WITH WEAK WESTERLY FLOW ALOFT ACROSS THE EASTERN MTS
AT THIS TIME. NOT AS CONCERNED WITH THE HEAVY RAIN THREAT ACROSS
WESTERN PORTIONS OF THE AREA WITH FLOW ALOFT A TAD FASTER WITH DEW
PTS DOWN INTO THE 30S AT THIS TIME. CLEARING SKIES EXPECTED THROUGH
THE OVERNIGHT AND HAVE FOLLOWED CLOSER TO THE COOLER SIDE OF
GUIDANCE FOR OVERNIGHT LOWS.
WEDNESDAY...UPPER LEVEL RIDGING CONTINUES TO BUILD ACROSS THE
CENTRAL ROCKIES AND INTO THE NORTHERN ROCKIES WITH UPPER FLOW
BECOMING MORE SOUTHERLY ACROSS WESTERN PORTIONS OF THE AREA AND
MORE NORTHERLY ACROSS EASTERN PORTIONS OF THE STATE...THOUGH
REMAINING WEAK. MOISTURE PLUME ACROSS EASTERN COLORADO GETS PUSHED
SOUTH AND EAST OF THE AREA...THOUGH ENOUGH MOISTURE TO REMAIN
UNDERNEATH BUILDING RIDGE TO SUPPORT MORE ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS ACROSS THE AREA...WITH BEST COVERAGE OVER
THE HIGHER TERRAIN. LATEST NAM CONTINUES TO INDICATED STORMS FIRING
ALONG OLD BOUNDARY ACROSS THE NEW MEXICO BORDER IN THE LATE
AFTERNOON WITH THE GFS KEEPING THE BOUNDARY WELL SOUTH OF THE AREA.
AT ANY RATE...HAVE KEPT ISOLATED POPS ACROSS THE FAR SOUTHEAST
PLAINS WITH CONVECTIVE TEMPS IN THE MID 90S BEING REACHED. WITH
DRIER AIR ACROSS REGION...HEAVY RAIN THREAT DIMINISHES...THOUGH A
LOCALLY HEAVY RAINER WILL STILL BE POSSIBLE WITH THE WEAK FLOW ALOFT.
TEMPERATURES LOOK TO BE AROUND OR SLIGHTLY WARMER THAN TODAY. -MW
.LONG TERM...
STAGNANT WX PATTERN WILL BE OVER THE REGION DURING THIS FCST PD.
CENTER OF MID LVL HI PRESSURE SYSTEM WILL DEVELOP PRETTY MUCH OVER
THE E PLAINS OF CO. THIS WILL FORCE THE MAIN MSTR PLUME TO THE WEST
OF THE FCST AREA...GENERALLY FROM THE CONTDVD ON WEST. EAST OF THE
CONTDVD IT WILL GENERALLY BE DRY...ESPECIALLY OVER THE PLAINS. WITH
THE HIGH DIRECTLY OVERHEAD...MAX TEMPERATURES ON THE PLAINS WILL
LIKELY GET UP INTO THE 100S AND REMAIN THERE THROUGHOUT THE FCST PD.
OVERALL THROUGH THIS FCST PD...I EXPECT SCTD AFTERNOON POPS OVER
THE CONTDVD...ISOLD POPS OVER THE REST OF THE MTNS AND VALLEYS...AND
HOT AND DRY ELSEWHERE.
GIVEN THE LOCATION OF THE MID LEVEL HIGH PRESSURE CELL DURING THIS
PERIOD...THE PROBABILITY OF FLASH FLOODING OVER THE WALDO BURN SCAR
WILL LIKELY BE LESS THAN NORMAL. /HODANISH
&&
.AVIATION...
ISOLATED TO SCATTERED STORMS TO REMAIN POSSIBLE ACROSS THE HIGHER
TERRAIN THROUGH THE EARLY EVENING...WITH A FEW STORMS SPREAD EAST
ACROSS THE IMMEDIATE ADJACENT PLAINS. BEST CHANCES OF AFFECTING
TERMINALS STILL REMAINS AT COS THROUGH 02Z WITH BRIEF MVFR CIGS AND
VIS ALONG WITH GUSTY OUTFLOW WINDS OF 25-35KTS POSSIBLE WITH STORMS.
VFR CONDITIONS WITH CLEARING SKIES AFT 06Z. AFTERNOON CONVECTION
TOMORROW TO REMAIN MORE OVER THE HIGHER TERRAIN. -MW
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
23/34
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
408 PM EDT TUE JUL 17 2012
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
PRIMARY CONCERN IS COVERAGE OF TSRA THIS AFTERNOON AND EVOLUTION
THIS EVENING. SO FAR TODAY...CONVECTION CLOSELY FOLLOWING MORNING
HRRR RUNS WITH ONE COMPLEX MOVING THROUGH EAST AND NOW SOUTHERN
PARTS OF ATL METRO. OTHER SCT STORMS ACROSS WESTCENTRAL AND FAR NE
GA. HRRR DID PROG ABUNDANT CONVECTION OVER NW GA TO NRN AL ALONG
CUMBERLAND PLATEAU AFTER 21Z WHICH IS NOT PANNING OUT SO FAR.
EXPECT TSRA TO CONTINUE TO PUSH SLOWLY SSW. HEAVY RAIN HAS BEEN
OCCURRING BUT FORTUNATELY...NO ONE AREA IS APPROACHING FFG.
EXPECTION TSRA TO WEAKEN SOME AFTER 6PM AND DISSIPATE BY 9PM.
UPPER LOW OVER NRN FL CONTINUES TO BE PRIMARY FEATURE. THIS LOW
PROGGED BY ALL MODELS TO DRIFT NORTH TONIGHT AND TOMORROW AS IT
GETS PICKED UP BY WEAK WESTERLIES WHICH DRIFT INTO THE MID
ATLANTIC WED. IMPACT FOR CWA IS HIGH MEAN RH AND CONTINUED DIURNAL
CONVECTION WITH NO PREFERENCE FOR ANY ONE LOCATION. CHC POPS
APPEAR MOST APPROPRIATE. ISOLD SVR STORMS AGAIN LIKELY. IF WE GET
MORE CLOUDS OR MORNING PRECIP WED...WILL SEE LESS THAN TODAY.
HAVE TWEAKED MAX TEMP GUIDANCE UP A LITTLE BASED ON RECENT TRENDS
AND MORE ISOLATED AFTERNOON CONVECTION THAN MODELS DEPICTING.
GUIDANCE BLEND WORKING WELL WITH SLIGHT UPWARD ADJUSTMENT FOR MIN
TEMPS.
SNELSON
.LONG TERM /THURSDAY THROUGH TUESDAY/...
MINOR DISCREPANCIES IN MODEL SOLUTIONS FOR THE LONG TERM BUT OVERALL
DECENT GENERAL CONSENSUS. GFS HAS GREATER AMOUNTS OF MOISTURE THAN
THE ECMWF FOR MUCH OF THE FORECAST PERIOD AND SLIGHT DIFFERENCES IN
LOCATION OF THE SFC FRONT PROGGED TO DIP SOUTHWARD INTO THE AREA FOR
THE WEEKEND. DUE TO UNCERTAINTY WITH LOCATION OF THIS BOUNDARY THIS
LATE IN THE FORECAST PERIOD... HAVE MAINTAINED CURRENT FORECAST.
PREVIOUS DISCUSSION FOLLOWS...
BAKER
/ISSUED AT 355 AM EDT TUE JUL 17 2012/
MODEL AGREEMENT THROUGH THE WEEKEND IS FAIRLY GOOD...WITH ATLANTIC
RIDGE REMAINING OFF THE EAST COAST AS UPPER LEVEL ENERGY REMAINS
ACROSS THE SOUTHEAST. TROUGH STRETCHES DOWN THE APPALACHIANS AND
EXTENDS INTO NORTH AND CENTRAL GEORGIA THROUGH THE LATER HALF OF
THE WEEK AS SURFACE LOW EXPECTED TO DEVELOP OVER THE CAROLINAS
INTO THE WEEKEND. IN ADDITION...A FRONTAL BOUNDARY PUSHES INTO THE
TENNESSEE VALLEY BY THE END OF THE WORK WEEK...AND INTO NORTH
GEORGIA BY SUNDAY MORNING. THE COMBINATION OF THESE FEATURES WILL
KEEP AMPLE MOISTURE AND ENOUGH INSTABILITY TO SUPPORT GOOD CHANCE
POPS ACROSS THE MAJORITY OF THE AREA THROUGH SUNDAY. BY NEXT
WEEK...MODEL SOLUTIONS DIFFER...THOUGH NOT AS SIGNIFICANTLY AS IN
DAYS PAST. EXTENDED MODELS AGREE WITH YET ANOTHER FRONTAL BOUNDARY
PUSHING INTO THE REGION BY TUESDAY AFTERNOON...BUT EXPECTED
IMPACTS DIFFER. ECMWF 1-2C COOLER WITH 850MB TEMPERATURES THAN THE
GFS AS THIS EARLY WEEK EVENT UNFOLDS. AS A RESULT...COULD SEE
SLIGHTLY COOLER HIGHS AS EARLY AS SUNDAY...WITH MORE SEASONAL
AFTERNOON TEMPS IN THE UPPER 80S. GRADUAL WARMING TREND EXPECTED
INTO TUESDAY WITH HIGHS BACK IN THE LOW 90S.
PRECIP ACTIVITY THROUGH THE EXTENDED WILL INCREASE EACH
AFTERNOON...COUPLED LARGELY WITH THE DIURNAL HEATING.
MOIST ENVIRONMENT WILL PERSIST THROUGH THE WEEK AND INTO THE
WEEKEND...WITH MODEL SOUNDINGS INDICATING PRECIPITABLE WATER
VALUES NEARING 2.0 INCHES.
31
&&
AVIATION...
18Z UPDATE...
PRIMARY CONCERN IS TIMING AND LIKELIHOOD OF TSRA THIS AFTERNOON.
MOST LIKELY TIME FOR TSRA IS 18Z-22Z WITH DECREASING COVERAGE
AFTER. COULD SEE WIND GUSTS TO 25KTS WITH ANY STRONG STORMS. HAVE
INCLUDED VCSH FOR 22Z- 01Z FOR LINGERING PRECIP. SIMILAR PATTERN
TOMORROW WITH MAINLY AFTERNOON TSRA. WEST COMPONENT WINDS EXPECTED
THROUGH THE PERIOD.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM CONFIDENCE ON TIMING AND LIKELIHOOD OF TSRA
HIGH ON ALL OTHER ELEMENTS
SNELSON
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 71 95 71 94 / 20 40 30 40
ATLANTA 74 92 73 91 / 20 50 30 40
BLAIRSVILLE 67 88 68 87 / 20 40 30 50
CARTERSVILLE 69 93 70 92 / 20 50 30 50
COLUMBUS 75 94 73 92 / 30 50 40 50
GAINESVILLE 72 93 72 91 / 20 40 30 50
MACON 73 94 72 93 / 30 50 30 40
ROME 70 94 71 92 / 20 50 30 50
PEACHTREE CITY 70 93 70 91 / 20 50 40 40
VIDALIA 74 94 74 95 / 30 50 40 40
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
SEVERE THUNDERSTORM WATCH UNTIL 8 PM EDT THIS EVENING FOR THE
FOLLOWING ZONES: CRISP...DODGE...DOOLY...MONTGOMERY...PULASKI...
STEWART...SUMTER...TELFAIR...TOOMBS...WEBSTER...WHEELER...WILCOX.
&&
$$
SHORT TERM...SNELSON
LONG TERM....BAKER
AVIATION...SNELSON
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
200 PM EDT TUE JUL 17 2012
.PREV DISCUSSION... /ISSUED 113 PM EDT TUE JUL 17 2012/
UPDATE...
QUICK UPDATE TO TWEAK POPS AND WX BASED ON CURRENT TRENDS. TWEAKED
DOWN TEMPS A LITTLE BASED ON MORNING CLOUDS AND EXPECTED PRECIP.
NEW WATCH CONFINED TO FAR SOUTHERN COUNTIES BUT COULD SEE ISOLD
SEVERE STORMS JUST ABOUT ANYWHERE. CONVECTION ALLOWING MODELS...ESP
RECENT HRRR RUNS...FAVORING SOUTHERN GA...NE GA AND ERN ATL METRO THRU
21Z THEN NW GA AFTER 21Z. SEEMS REASONABLE. MID LEVEL CLOUDS
FINALLY DISSIPATING WHICH SHOULD ALLOW TEMPS TO CLIMB QUICKLY.
CAPE ALREADY NEAR 3000 J/KG BASED ON SPC MESOANALYSIS. 0-1KM AND
0-6KM SHEAR VERY WEAK SO EXPECT SLOW MOVING PULSE STORMS YET
AGAIN. PW NEAR 1.9 INCHES SO VERY HEAVY RAINFALL LIKELY WITH ISOLD
FLOODING POSSIBLE.
SNELSON
PREV DISCUSSION... /ISSUED 723 AM EDT TUE JUL 17 2012/
SHORT TERM /TODAY THROUGH WEDNESDAY NIGHT/...
/ISSUED AT 355 AM EDT TUE JUL 17 2012/
A COMBINATION OF TWO MAIN FEATURES WILL BE THE FOCUS FOR
THUNDERSTORM DEVELOPMENT THROUGH 48 HOURS. AN H5 LOW JUST OFF THE
GA/FL COAST WAS MOVING ONSHORE AND THE GFS/NAM HAVE A GOOD HANDLE ON
THIS. THIS LOW WILL STALL OVER NORTH FL/SOUTH GA AND CONTINUE TO
PUMP IN ATLANTIC MOISTURE TO THE CWA. THIS UPPER LOW WAS ALSO
PULLING A WEAK SHORT WAVE INTO THE CWA. AT THE SAME TIME A LEE SIDE
TROUGH WAS DEVELOPING FROM LGC TO UPSTATE SOUTH CAROLINA. THE
COMBINATION OF THESE ARE BRINGING THE THREAT OF THUNDERSTORMS TO THE
CWA WITH THE MAIN THREAT DURING DAYTIME HEATING BOTH TODAY AND
WEDNESDAY. THE HIGHEST PROBABILITIES WILL BE IN THE VICINITY OF THE
UPPER LOW...ACROSS CENTRAL GA. THIS WILL ALSO HAVE A PLAY ON TEMPS.
MOST AREAS MONDAY SAW TEMPS IN THE LOW TO MID 90S...HOWEVER IN AREAS
THAT GOT RAIN...TEMPS STRUGGLED TO GET OUT OF THE UPPER 80S. NO
CHANGE IN AIRMASS THROUGH WEDNESDAY AND THIS SHOULD YIELD A
PERSISTENCE IN TEMP FORECASTS.
17
LONG TERM /THURSDAY THROUGH MONDAY/...
/ISSUED AT 355 AM EDT TUE JUL 17 2012/
MODEL AGREEMENT THROUGH THE WEEKEND IS FAIRLY GOOD...WITH ATLANTIC
RIDGE REMAINING OFF THE EAST COAST AS UPPER LEVEL ENERGY REMAINS
ACROSS THE SOUTHEAST. TROUGH STRETCHES DOWN THE APPALACHIANS AND
EXTENDS INTO NORTH AND CENTRAL GEORGIA THROUGH THE LATER HALF OF
THE WEEK AS SURFACE LOW EXPECTED TO DEVELOP OVER THE CAROLINAS
INTO THE WEEKEND. IN ADDITION...A FRONTAL BOUNDARY PUSHES INTO THE
TENNESSEE VALLEY BY THE END OF THE WORK WEEK...AND INTO NORTH
GEORGIA BY SUNDAY MORNING. THE COMBINATION OF THESE FEATURES WILL
KEEP AMPLE MOISTURE AND ENOUGH INSTABILITY TO SUPPORT GOOD CHANCE
POPS ACROSS THE MAJORITY OF THE AREA THROUGH SUNDAY. BY NEXT
WEEK...MODEL SOLUTIONS DIFFER...THOUGH NOT AS SIGNIFICANTLY AS IN
DAYS PAST. EXTENDED MODELS AGREE WITH YET ANOTHER FRONTAL BOUNDARY
PUSHING INTO THE REGION BY TUESDAY AFTERNOON...BUT EXPECTED
IMPACTS DIFFER. ECMWF 1-2C COOLER WITH 850MB TEMPERATURES THAN THE
GFS AS THIS EARLY WEEK EVENT UNFOLDS. AS A RESULT...COULD SEE
SLIGHTLY COOLER HIGHS AS EARLY AS SUNDAY...WITH MORE SEASONAL
AFTERNOON TEMPS IN THE UPPER 80S. GRADUAL WARMING TREND EXPECTED
INTO TUESDAY WITH HIGHS BACK IN THE LOW 90S.
PRECIP ACTIVITY THROUGH THE EXTENDED WILL INCREASE EACH
AFTERNOON...COUPLED LARGELY WITH THE DIURNAL HEATING.
MOIST ENVIRONMENT WILL PERSIST THROUGH THE WEEK AND INTO THE
WEEKEND...WITH MODEL SOUNDINGS INDICATING PRECIPITABLE WATER
VALUES NEARING 2.0 INCHES.
31
&&
.AVIATION...
18Z UPDATE...
PRIMARY CONCERN IS TIMING AND LIKELIHOOD OF TSRA THIS AFTERNOON.
MOST LIKELY TIME FOR TSRA IS 18Z-22Z WITH DECREASING COVERAGE
AFTER. COULD SEE WIND GUSTS TO 25KTS WITH ANY STRONG STORMS. HAVE
INCLUDED VCSH FOR 22Z- 01Z FOR LINGERING PRECIP. SIMILAR PATTERN
TOMORROW WITH MAINLY AFTERNOON TSRA. WEST COMPONENT WINDS EXPECTED
THROUGH THE PERIOD.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM CONFIDENCE ON TIMING AND LIKELIHOOD OF TSRA
HIGH ON ALL OTHER ELEMENTS
SNELSON
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 93 72 94 72 / 50 30 50 30
ATLANTA 92 74 92 73 / 40 30 50 30
BLAIRSVILLE 87 68 87 67 / 40 30 40 30
CARTERSVILLE 92 70 92 71 / 50 30 40 30
COLUMBUS 93 74 94 73 / 40 30 50 30
GAINESVILLE 92 72 92 72 / 50 30 40 30
MACON 91 73 94 73 / 50 30 50 30
ROME 93 70 94 72 / 60 30 40 30
PEACHTREE CITY 91 71 92 71 / 40 30 50 30
VIDALIA 92 74 94 75 / 50 30 50 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
SEVERE THUNDERSTORM WATCH UNTIL 8 PM EDT THIS EVENING FOR THE
FOLLOWING ZONES: CRISP...DODGE...DOOLY...MONTGOMERY...PULASKI...
STEWART...SUMTER...TELFAIR...TOOMBS...WEBSTER...WHEELER...WILCOX.
&&
$$
SHORT TERM...SNELSON
LONG TERM....BAKER
AVIATION...SNELSON
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
113 PM EDT TUE JUL 17 2012
.UPDATE...
QUICK UPDATE TO TWEAK POPS AND WX BASED ON CURRENT TRENDS. TWEAKED
DOWN TEMPS A LITTLE BASED ON MORNING CLOUDS AND EXPECTED PRECIP.
NEW WATCH CONFINED TO FAR SOUTHERN COUNTIES BUT COULD SEE ISOLD
SEVERE STORMS JUST ABOUT ANYWHERE. CONVECTION ALLOWING MODELS...ESP
RECENT HRRR RUNS...FAVORING SOUTHERN GA...NE GA AND ERN ATL METRO THRU
21Z THEN NW GA AFTER 21Z. SEEMS REASONABLE. MID LEVEL CLOUDS
FINALLY DISSIPATING WHICH SHOULD ALLOW TEMPS TO CLIMB QUICKLY.
CAPE ALREADY NEAR 3000 J/KG BASED ON SPC MESOANALYSIS. 0-1KM AND
0-6KM SHEAR VERY WEAK SO EXPECT SLOW MOVING PULSE STORMS YET
AGAIN. PW NEAR 1.9 INCHES SO VERY HEAVY RAINFALL LIKELY WITH ISOLD
FLOODING POSSIBLE.
SNELSON
&&
.PREV DISCUSSION... /ISSUED 723 AM EDT TUE JUL 17 2012/
SHORT TERM /TODAY THROUGH WEDNESDAY NIGHT/...
/ISSUED AT 355 AM EDT TUE JUL 17 2012/
A COMBINATION OF TWO MAIN FEATURES WILL BE THE FOCUS FOR
THUNDERSTORM DEVELOPMENT THROUGH 48 HOURS. AN H5 LOW JUST OFF THE
GA/FL COAST WAS MOVING ONSHORE AND THE GFS/NAM HAVE A GOOD HANDLE ON
THIS. THIS LOW WILL STALL OVER NORTH FL/SOUTH GA AND CONTINUE TO
PUMP IN ATLANTIC MOISTURE TO THE CWA. THIS UPPER LOW WAS ALSO
PULLING A WEAK SHORT WAVE INTO THE CWA. AT THE SAME TIME A LEE SIDE
TROUGH WAS DEVELOPING FROM LGC TO UPSTATE SOUTH CAROLINA. THE
COMBINATION OF THESE ARE BRINGING THE THREAT OF THUNDERSTORMS TO THE
CWA WITH THE MAIN THREAT DURING DAYTIME HEATING BOTH TODAY AND
WEDNESDAY. THE HIGHEST PROBABILITIES WILL BE IN THE VICINITY OF THE
UPPER LOW...ACROSS CENTRAL GA. THIS WILL ALSO HAVE A PLAY ON TEMPS.
MOST AREAS MONDAY SAW TEMPS IN THE LOW TO MID 90S...HOWEVER IN AREAS
THAT GOT RAIN...TEMPS STRUGGLED TO GET OUT OF THE UPPER 80S. NO
CHANGE IN AIRMASS THROUGH WEDNESDAY AND THIS SHOULD YIELD A
PERSISTENCE IN TEMP FORECASTS.
17
LONG TERM /THURSDAY THROUGH MONDAY/...
/ISSUED AT 355 AM EDT TUE JUL 17 2012/
MODEL AGREEMENT THROUGH THE WEEKEND IS FAIRLY GOOD...WITH ATLANTIC
RIDGE REMAINING OFF THE EAST COAST AS UPPER LEVEL ENERGY REMAINS
ACROSS THE SOUTHEAST. TROUGH STRETCHES DOWN THE APPALACHIANS AND
EXTENDS INTO NORTH AND CENTRAL GEORGIA THROUGH THE LATER HALF OF
THE WEEK AS SURFACE LOW EXPECTED TO DEVELOP OVER THE CAROLINAS
INTO THE WEEKEND. IN ADDITION...A FRONTAL BOUNDARY PUSHES INTO THE
TENNESSEE VALLEY BY THE END OF THE WORK WEEK...AND INTO NORTH
GEORGIA BY SUNDAY MORNING. THE COMBINATION OF THESE FEATURES WILL
KEEP AMPLE MOISTURE AND ENOUGH INSTABILITY TO SUPPORT GOOD CHANCE
POPS ACROSS THE MAJORITY OF THE AREA THROUGH SUNDAY. BY NEXT
WEEK...MODEL SOLUTIONS DIFFER...THOUGH NOT AS SIGNIFICANTLY AS IN
DAYS PAST. EXTENDED MODELS AGREE WITH YET ANOTHER FRONTAL BOUNDARY
PUSHING INTO THE REGION BY TUESDAY AFTERNOON...BUT EXPECTED
IMPACTS DIFFER. ECMWF 1-2C COOLER WITH 850MB TEMPERATURES THAN THE
GFS AS THIS EARLY WEEK EVENT UNFOLDS. AS A RESULT...COULD SEE
SLIGHTLY COOLER HIGHS AS EARLY AS SUNDAY...WITH MORE SEASONAL
AFTERNOON TEMPS IN THE UPPER 80S. GRADUAL WARMING TREND EXPECTED
INTO TUESDAY WITH HIGHS BACK IN THE LOW 90S.
PRECIP ACTIVITY THROUGH THE EXTENDED WILL INCREASE EACH
AFTERNOON...COUPLED LARGELY WITH THE DIURNAL HEATING.
MOIST ENVIRONMENT WILL PERSIST THROUGH THE WEEK AND INTO THE
WEEKEND...WITH MODEL SOUNDINGS INDICATING PRECIPITABLE WATER
VALUES NEARING 2.0 INCHES.
31
AVIATION...
12Z UPDATE...
EXPECT RAPID CU DEVELOPMENT THIS MORNING WITH SCATTERED SHRA/TSRA
DEVELOPING AROUND NOON AND CONTINUING INTO THIS EVENING. WINDS
OVERALL WILL BE NORTH TO NORTHWEST AROUND 7 KTS OR LESS...EXCEPT
GUSTY IN TSRA. WINDS SHOULD GO CALM THIS EVENING.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM ON TIMING OF TSRA
HIGH ON ALL OTHER ELEMENTS
17
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 93 72 94 72 / 50 30 50 30
ATLANTA 92 74 92 73 / 40 30 50 30
BLAIRSVILLE 87 68 87 67 / 40 30 40 30
CARTERSVILLE 92 70 92 71 / 50 30 40 30
COLUMBUS 93 74 94 73 / 40 30 50 30
GAINESVILLE 92 72 92 72 / 50 30 40 30
MACON 91 73 94 73 / 50 30 50 30
ROME 93 70 94 72 / 60 30 40 30
PEACHTREE CITY 91 71 92 71 / 40 30 50 30
VIDALIA 92 74 94 75 / 50 30 50 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
SEVERE THUNDERSTORM WATCH UNTIL 8 PM EDT THIS EVENING FOR THE
FOLLOWING ZONES: CRISP...DODGE...DOOLY...MONTGOMERY...PULASKI...
STEWART...SUMTER...TELFAIR...TOOMBS...WEBSTER...WHEELER...WILCOX.
&&
$$
SHORT TERM...SNELSON
LONG TERM....BAKER
AVIATION...SNELSON
AREA FORECAST DISCUSSION
NWS ALBANY NY
418 PM EDT TUE JUL 17 2012
.SYNOPSIS...
A HOT AND HUMID AIR MASS WILL LINGER ACROSS THE REGION TODAY. A COLD
FRONT WILL SAG SLOWLY SOUTH FROM THE SAINT LAWRENCE VALLEY THIS
EVENING...REACHING THE MOHAWK VALLEY WEDNESDAY MORNING...AND THE
LONG ISLAND SOUND BY WEDNESDAY EVENING. HIGH PRESSURE WILL BUILD
FROM HUDSON`S VALLEY LATE WEDNESDAY INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
WMFNT AND ITS CLOUDS AND -SHRA/TSTMS HAS MOVED E OF FCA. PATCHY
MID CLOUDS ACROSS S TIER AND VT...WITH CLEARING OVER REST OF FCA.
THE CLOUDS WILL CLEAR THE S AND E PTNS OF FCA 17-18UTC.
WITH FULL SUN FOR SVRL HRS CONVECTIVE POTENTIAL EVOLVES...AND
CURRENT THINKING HAS NOT CHANGED FM EARLIER TDY. WHILE 12UTC ALB
SNDG AND MDL SOUNDINGS ACROSS FCA SHOW SOME CAPPING...BUF 12UTC
SNDG AND MDL SNDGS INDICATE THIS WILL BE GONE PARTICULARLY N HALF
OF BTWN 18-21UTC.
MOST GUID AND MDL SOUNDINGS HAVE 1000-2000 J/KG OF CAPE ACROSS FCA
AND MINIMAL CIN VALUES BY 21UTC...AGAIN PARTICULARLY N. MAIN ISSUE
AT LEAST INTO THE EVENING IS LACK OF LARGE SCALE FORCING. MID AND
UPR JET AXIS AND FAVORABLE QUADS REMAIN WELL N OF FCA...WITH ONLY
MINIMAL INTERACTION ACROSS N TIER THIS AFTN. AS THIS SHIFTS S TNGT
THE DYNAMICS WILL ALSO SHIFT S....BY NOT UNTIL AFT 03UTC.
IN SPITE OF A LACK OF LARGE SCALE DYNAMIC FORCING THERE`S DIURNAL
HEATING...AND MOST AREAS WILL SEE L/M 90S...ELEVATED TRRN...GRTLKS
LAKE BREEZES...COLD POOLS AND OUTFLOW BOUNDARIES FROM CONVECTION
TO THE N...A WEAK TROF ACROSS THE E GRTLKS...AND LOCAL EFFECTS TO
TRIGGER CONVECTION. H850 HPA JET OF 30-50KTS NOSES INTO FCA
DURING THE AFTN...AND IT COULD BE SUFFICIENT W/ EXPECTED CAPE TO
GET THINGS GOING. ADD PWATS OF 1.50-ALMOST 2.0 TODAY.
ON THE LARGER SCALE SFC LOW IN OTTAWA VALLEY WILL ZIP EAST TO
MAINE BY EVENING...AND ITS TRAILING CDFNT WILL START TO SAG INTO
N TIER OF NYS BY 00UTC...REACHING THE MHWK VLY BY WED MORNING.
MOST OF LARGE SCALE AND LOCAL MESO SCALE WRF AND HRRR MODELS HV
CONVECTION FIRING ALONG AND AHEAD OF THE CDFNT DURING THE MID AFTN
NR CANADIAN/USA BORDER...AND SHIFTING TO N TIER OF FCA 21-23UTC.
ALL THESE MODELS MAINTAIN THIS CONVECTION INTO THE EVENING AS IT
SHIFTS ESE...POSSIBLY REACHING MHWK VLY/CAP RGN. BUT MODELS WEAKEN
CONVECTION WITH THE END OF DIURNAL HEATING...AND RESURGENCE OF THE
CAP OVERNIGHT. WITH H850 JET PUNCHING EAST....0-6 KM DEEP BULK
SHEAR VALUES ARE ALREADY 40+...MHWK VLY AND N.
SPC HAS OUTLOOKED N HALF OF FCA TODAY. POTENTIAL WATCH DECISION
95% BASED ON LATEST MCD. BUT THE SOUTHERN EXTENT OF SVR CONVECTION
REMAINS QUESTIONABLE.
IN SUMMARY EXPECT A HOT HUMID AFTN. CONVECTION ORGANIZING ALONG N
NY BORDER. APPEARS CURRENT LINE ALONG NVT/N NH IS BACK BUILDING INTO
NYS...AND THIS WILL BCM MORE ORGANIZED NEXT FEW HRS AND SHIFT ESE.
HOW FAR SOUTH REMAINS A QUESTION...BUT N TIER OF FCA REMAINS AT
RISK FOR POSSIBLE SVR. ISOLD-SCT CELLS COULD STILL FORM AFTER CAPS
GIVE WAY THIS AFTN ANYWHERE FM MHWK VLY N AND THESE COULD BCM
QUITE HEALTHY...WITH HEAVY DOWNPOURS.
AS CDFNT SAGS SLOWLY S TNGT IT WILL REMAIN FOCUS OF -SHRA AND
CONVECTION...BUT MDLS CLEARLY SUG CONVECTION WEAKENS CONSIDERABLY
OVERNIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
AFTER A LATE NIGHT LUL IN CONVECTION MDL SUITE IN AGREEMENT WITH
CDFNT BEGINNING THE DAY IN MHWK VLY AND CONTINUING SWRD.
CONVECTION FIRES MID DAY...WITH MAIN THREAT S & E OF ALB. WITH S
AREAS IN BETTER JET DYNAMICS...JUXTAPOSED TO CDFNT AND CAPES
REBUILDING TO 1500-3000 J/KG ASSORTED GUIDANCE INDICATES THE
LIKELY LOCATIONS FOR A SVR CONVECTION THREAT WILL BE SOUTH OF
ALBANY.
VARIATIONS IN CLOUD COVER COULD DAMPEN THIS RESPONSE AND LOCAL WRF
DOESN`T GET CONVECTION WELL ORGANIZED TILL ITS STRADDLING THE
SOUTH TIER OF COUNTIES WED.
WITH PWATS STILL IN THE 1.50-2.00 INCH RANGE SOUTH SOME LOCALLY
HVY DOWNPOURS ARE POSSIBLE...AS SOME LOCATIONS COULD RECEIVE A
QUICK FEW INCHES OF RAINFALL. THE MID LEVEL FLOW IS FAST...SO ANY
CELLS SHOULD BE FAST MOVERS...AND LARGE PCPN DEFICITS CONTINUE
OVER THE HSA.
FURTHER N WED TEMPS WILL REMAIN ABV NORMALS ONE MORE DAY BUT
DRIER AIR WILL BE FILTERING INTO N TIER WITH CLEARING.
WED NT CDFNT MOVES S OF FCA...MOST OF AREA CLEARS AND DRIES..HWVR
CLOUDS MAY LINGER OVER S PTNS OF FCA. WHAT WILL BE VERY NOTICEABLE
IS DEPARTURE OF HUMIDITY AS TD DROP INTO 50S.
BY THU LARGE SFC HIGH BUILDS SE INTO FCA FM ONT/HUD BAY WITH FAIR
AND SEASONABLE CONDS ACROSS ENTIRE FCA INTO THU NT.
A RECENT WRINKLE IN NAM/GFS IS THE FORMATION OF A WAVE ALONG THE
STALLED FRONT TO OUR SOUTH LATE THU AND FRI OVER S VA. WHILE NOT
AS VIGOROUS AS THE 06UTC RUNS,..THE CURRENT SUITE BRINGS INCRG
CLOUDS AND CHC -SHRA TO S TIER OF FCA LATE FRI.
WILL POPULATE THIS PERIOD WITH MET/MAV BLEND AS GUID IN CLOSE
AGREEMENT.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
A NICE START TO THE WEEKEND AS A RIDGE OF HIGH PRESSURE WILL BE OVER
THE REGION ON SATURDAY. THE GFS WANTS TO LINGER ONTO THE UPPER TROF
AXIS AND RESULTS IN ISOLATED CONVECTION ACROSS THE REGION.
HOWEVER...THE GFS ALSO HINTS AT RISING HEIGHTS WHICH IS ALONG THE
SAME AS OTHER GLOBAL GUIDANCE. WE WILL RETAIN THE DRY FORECAST
ALONG WITH AT OR SLIGHTLY BELOW NORMAL TEMPERATURES.
THEN TRENDS ON SUNDAY ARE BECOMING A LITTLE MORE ACTIVE...BUT NOT A
WASHOUT. ANOTHER SHORTWAVE WITHIN THE NORTHWEST FLOW REGIME ALOFT
IS EXPECTED TO TRACK TOWARD THE GREAT LAKES REGION LATER ON SUNDAY.
AT THIS TIME...WE WILL INTRODUCE A SLIGHT CHANCE FOR CONVECTION AND
CONTINUE TO MONITOR TRENDS. BY SUNDAY NIGHT...ALL OF THE AVAILABLE
GUIDANCE SUGGESTS A PV ANOMALY CROSSES THE REGION. WE WILL HAVE THE
HIGHER POPS...30-40 PERCENT...AT THIS TIME ACROSS MOST OF THE REGION
SUNDAY NIGHT.
BY MONDAY...THAT PV ANOMALY DOES TRACK EAST YET THE CYCLONIC FLOW
REGIME REMAINS IN PLACE. THE ECMWF/DGEX WANTS TO LINGER A SURFACE
TROUGH ACROSS THE REGION WHILE THE GFS IS THE MOST AGGRESSIVE TO
CLEAR OUT OF OUR SOUTHERN COUNTIES. HPC GUIDANCE IS SOMEWHAT IN THE
MIDDLE OF THE GUIDANCE ENVELOPE AND HAVE FOLLOWED THE GUIDANCE
CLOSELY. TEMPERATURES AND DEWPOINTS WILL BE ON THE CLIMB AS WELL AS
WE AVERAGE TOWARD ABOVE NORMAL INTO EARLY NEXT WEEK.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
SHOWERS AND THUNDERSTORMS WILL BE PRIMARILY CONFINED TO FAR NORTHERN
AREAS LATER TODAY AND TONIGHT AS A COLD FRONT DROPS SOUTH FROM
CANADA. AN ISOLATED THUNDERSTORM IS NOT OUT OF THE QUESTION FURTHER
SOUTH BUT TO LOW OF PROBABILITY TO MENTION IN A TAF. INCREASING
SOUTHWEST WINDS ARE EXPECTED TO RESULT IN DOWNSLOPING IN THE HUDSON
VALLEY WHICH SHOULD ALSO HELP LIMIT CONVECTIVE ACTIVITY FOR MOST OF
THE TAF SITES. THE BEST CHANCE OF THUNDERSTORMS WILL BE AT KGFL LATE
THIS AFTERNOON INTO EARLY THIS EVENING. MODELS SHOW MOST CONVECTION
DYING OUT OVERNIGHT BUT SOME ISOLATED RAIN SHOWERS AND FOG AND
STRATO CU EXPECTED AS MOISTURE POOLS AHEAD OF COLD FRONT. FOR
TOMORROW...COLD FRONT CONTINUES TO MOVE SOUTH WITH BEST CHANCE OF
THUNDERSTORMS OVER SOUTHERN AREAS AS COLD FRONT CONTINUES SOUTH.
SOUTHWEST WINDS 10 TO 15 KTS BY AFTERNOON SUBSIDING TO 3 TO 6 KTS
THIS EVENING. FOR WEDNESDAY...WINDS WEST TO NORTHWEST BECOMING
NORTHWEST TO NORTH AT 5 TO 10 KTS.
OUTLOOK...
WED...VFR/MVFR. SCT SHOWERS/TSTMS.
THU..NO SIG WX.
FRI-SUN...VFR...SLIGHT CHC ISOLD AFTERNOON TSTM.
&&
.FIRE WEATHER...
A HOT AND HUMID AIR MASS WILL LINGER ACROSS THE REGION TODAY. A COLD
FRONT WILL SAG SLOWLY SOUTH FROM THE SAINT LAWRENCE VALLEY THIS
EVENING...REACHING THE MOHAWK VALLEY WEDNESDAY MORNING...AND THE
LONG ISLAND SOUND BY WEDNESDAY EVENING. HIGH PRESSURE WILL BUILD
FROM HUDSON`S VALLEY LATE WEDNESDAY INTO THE WEEKEND.
RELATIVE HUMIDITY VALUES WILL INCREASE TO 80 TO 100 PERCENT
TONIGHT..AND RECOVER TO 40-60 PERCENT WEDNESDAY AFTERNOON. VALES
WEDNESDAY WILL INCREASE TO 60-80 PERCENT.
SOUTHWEST WINDS 10 TO 15 MPH WITH HIGHER GUSTS WILL BECOME LIGHT
AND VARIABLE TONIGHT AT 10 MPH OR LESS...AND INCREASE FROM THE
WEST NORTHWEST TO 5 TO 15 MPH ON WEDNESDAY.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED ON THE MAIN STEM RIVERS OVER THE
NEXT 5 DAYS.
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A FRONTAL PASSAGE
TONIGHT INTO WEDNESDAY WILL PRODUCE SOME HEAVY RAINFALL DUE TO A
SHORT PERIOD OF ANOMALOUSLY HIGH PRECIPITABLE WATER VALUES IN THE
1.5 TO 2 INCH RANGE. SOME PONDING OF WATER ON ROADWAYS OR POOR
DRAINAGE FLOODING IS POSSIBLE...ESPECIALLY ON WEDNESDAY. ZONAL
FLASH FLOOD GUIDANCE VALUES REMAIN HIGH FOR MID JULY. THE
POTENTIAL FOR FLASH FLOODING IS LOW AT THIS TIME IN THE ALY HYDRO
SERVICE AREA.
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...SNYDER
NEAR TERM...SNYDER
SHORT TERM...SNYDER
LONG TERM...BGM
AVIATION...
FIRE WEATHER...SNYDER
HYDROLOGY...WASULA/SNYDER
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS ALBANY NY
105 PM EDT TUE JUL 17 2012
.SYNOPSIS...
A HOT AND HUMID AIR MASS WILL LINGER ACROSS THE REGION TODAY. A COLD
FRONT WILL SAG SLOWLY SOUTH FROM THE SAINT LAWRENCE VALLEY THIS
EVENING...REACHING THE MOHAWK VALLEY WEDNESDAY MORNING...AND THE
LONG ISLAND SOUND BY WEDNESDAY EVENING. HIGH PRESSURE WILL BUILD
FROM HUDSON`S VALLEY LATE WEDNESDAY INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
WMFNT AND ITS CLOUDS AND -SHRA/TSTMS HAS MOVED E OF FCA. PATCHY
MID CLOUDS ACROSS S TIER AND VT...WITH CLEARING OVER REST OF FCA.
THE CLOUDS WILL CLEAR THE S AND E PTNS OF FCA 17-18UTC.
WITH FULL SUN FOR SVRL HRS CONVECTIVE POTENTIAL EVOLVES...AND
CURRENT THINKING HAS NOT CHANGED FM EARLIER TDY. WHILE 12UTC ALB
SNDG AND MDL SOUNDINGS ACROSS FCA SHOW SOME CAPPING...BUF 12UTC
SNDG AND MDL SNDGS INDICATE THIS WILL BE GONE PARTICULARLY N HALF
OF BTWN 18-21UTC.
MOST GUID AND MDL SOUNDINGS HAVE 1000-2000 J/KG OF CAPE ACROSS FCA
AND MINIMAL CIN VALUES BY 21UTC...AGAIN PARTICULARLY N. MAIN ISSUE
AT LEAST INTO THE EVENING IS LACK OF LARGE SCALE FORCING. MID AND
UPR JET AXIS AND FAVORABLE QUADS REMAIN WELL N OF FCA...WITH ONLY
MINIMAL INTERACTION ACROSS N TIER THIS AFTN. AS THIS SHIFTS S TNGT
THE DYNAMICS WILL ALSO SHIFT S....BY NOT UNTIL AFT 03UTC.
IN SPITE OF A LACK OF LARGE SCALE DYNAMIC FORCING THERE`S DIURNAL
HEATING...AND MOST AREAS WILL SEE L/M 90S...ELEVATED TRRN...GRTLKS
LAKE BREEZES...COLD POOLS AND OUTFLOW BOUNDARIES FROM CONVECTION
TO THE N...A WEAK TROF ACROSS THE E GRTLKS...AND LOCAL EFFECTS TO
TRIGGER CONVECTION. H850 HPA JET OF 30-50KTS NOSES INTO FCA
DURING THE AFTN...AND IT COULD BE SUFFICIENT W/ EXPECTED CAPE TO
GET THINGS GOING. ADD PWATS OF 1.50-ALMOST 2.0 TODAY.
ON THE LARGER SCALE SFC LOW IN OTTAWA VALLEY WILL ZIP EAST TO
MAINE BY EVENING...AND ITS TRAILING CDFNT WILL START TO SAG INTO
N TIER OF NYS BY 00UTC...REACHING THE MHWK VLY BY WED MORNING.
MOST OF LARGE SCALE AND LOCAL MESO SCALE WRF AND HRRR MODELS HV
CONVECTION FIRING ALONG AND AHEAD OF THE CDFNT DURING THE MID AFTN
NR CANADIAN/USA BORDER...AND SHIFTING TO N TIER OF FCA 21-23UTC.
ALL THESE MODELS MAINTAIN THIS CONVECTION INTO THE EVENING AS IT
SHIFTS ESE...POSSIBLY REACHING MHWK VLY/CAP RGN. BUT MODELS WEAKEN
CONVECTION WITH THE END OF DIURNAL HEATING...AND RESURGENCE OF THE
CAP OVERNIGHT. WITH H850 JET PUNCHING EAST....0-6 KM DEEP BULK
SHEAR VALUES ARE ALREADY 40+...MHWK VLY AND N.
SPC HAS OUTLOOKED N HALF OF FCA TODAY. POTENTIAL WATCH DECISION
95% BASED ON LATEST MCD. BUT THE SOUTHERN EXTENT OF SVR CONVECTION
REMAINS QUESTIONABLE.
IN SUMMARY EXPECT A HOT HUMID AFTN. CONVECTION ORGANIZING ALONG N
NY BORDER. APPEARS CURRENT LINE ALONG NVT/N NH IS BACK BUILDING INTO
NYS...AND THIS WILL BCM MORE ORGANIZED NEXT FEW HRS AND SHIFT ESE.
HOW FAR SOUTH REMAINS A QUESTION...BUT N TIER OF FCA REMAINS AT
RISK FOR POSSIBLE SVR. ISOLD-SCT CELLS COULD STILL FORM AFTER CAPS
GIVE WAY THIS AFTN ANYWHERE FM MHWK VLY N AND THESE COULD BCM
QUITE HEALTHY...WITH HEAVY DOWNPOURS.
AS CDFNT SAGS SLOWLY S TNGT IT WILL REMAIN FOCUS OF -SHRA AND
CONVECTION...BUT MDLS CLEARLY SUG CONVECTION WEAKENS CONSIDERABLY
OVERNIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
AFTER A LATE NIGHT LUL IN CONVECTION MDL SUITE IN AGREEMENT WITH
CDFNT BEGINNING THE DAY IN MHWK VLY AND CONTINUING SWRD.
CONVECTION FIRES MID DAY...WITH MAIN THREAT S & E OF ALB. WITH S
AREAS IN BETTER JET DYNAMICS...JUXTAPOSED TO CDFNT AND CAPES
REBUILDING TO 1500-3000 J/KG ASSORTED GUIDANCE INDICATES THE
LIKELY LOCATIONS FOR A SVR CONVECTION THREAT WILL BE SOUTH OF
ALBANY.
VARIATIONS IN CLOUD COVER COULD DAMPEN THIS RESPONSE AND LOCAL WRF
DOESN`T GET CONVECTION WELL ORGANIZED TILL ITS STRADDLING THE
SOUTH TIER OF COUNTIES WED.
WITH PWATS STILL IN THE 1.50-2.00 INCH RANGE SOUTH SOME LOCALLY
HVY DOWNPOURS ARE POSSIBLE...AS SOME LOCATIONS COULD RECEIVE A
QUICK FEW INCHES OF RAINFALL. THE MID LEVEL FLOW IS FAST...SO ANY
CELLS SHOULD BE FAST MOVERS...AND LARGE PCPN DEFICITS CONTINUE
OVER THE HSA.
FURTHER N WED TEMPS WILL REMAIN ABV NORMALS ONE MORE DAY BUT
DRIER AIR WILL BE FILTERING INTO N TIER WITH CLEARING.
WED NT CDFNT MOVES S OF FCA...MOST OF AREA CLEARS AND DRIES..HWVR
CLOUDS MAY LINGER OVER S PTNS OF FCA. WHAT WILL BE VERY NOTICABLE
IS DEPARTURE OF HUMIDITY AS TD DROP INTO 50S.
BY THU LARGE SFC HIGH BUILDS SE INTO FCA FM ONT/HUD BAY WITH FAIR
AND SEASONABLE CONDS ACROSS ENTIRE FCA INTO THU NT.
A RECENT WRINKLE IN NAM/GFS IS THE FORMATION OF A WAVE ALONG THE
STALLED FRONT TO OUR SOUTH LATE THU AND FRI OVER S VA. WHILE NOT
AS VIGOROUS AS THE 06UTC RUNS,..THE CURRENT SUITE BRINGS INCRG
CLOUDS AND CHC -SHRA TO S TIER OF FCA LATE FRI.
WILL POPULATE THIS PERIOD WITH MET/MAV BLEND AS GUID IN CLOSE
AGREEMENT.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
MAINLY DRY CONDITIONS WITH TEMPS AVERAGING NEAR NORMAL ARE EXPECTED
DURING THE LONG TERM PERIOD.
A LARGE RIDGE OF HIGH PRESSURE WILL BUILD ACROSS OUR REGION FROM
SOUTHERN CANADA ON FRIDAY AND SETTLE ACROSS OUR REGION ON SATURDAY
BEFORE SLIDING OFF THE EASTERN SEABOARD ON SUNDAY. A COLD FRONT IS
THEN EXPECTED TO DROP SOUTHEAST THROUGH OUR REGION FROM SOUTHERN
CANADA ON MONDAY. HOWEVER IT APPEAR AT THIS TIME THAT VERY LITTLE
MOISTURE EXISTS WITH THIS SYSTEM AND THE FRONTAL PASSAGE MAY OCCUR
WITH LITTLE IF ANY PCPN. H8 TEMPS GENERALLY REMAIN BETWEEN +10 AND
+14C UNTIL SUNDAY AFTERNOON WHEN VALUES RISE TO +15 TO +17 C AS
RETURN FLOW SETS UP WITH HIGH SLIDING OFF THE COAST TO OUR
SOUTHEAST. H8 TEMPS THEN ARE EXPECTED TO START FALLING BY MONDAY
AFTERNOON ACROSS NORTHERN HALF OF FA IN THE WAKE OF THE COLD FRONT.
EXPECT HIGHS ON FRIDAY IN THE 70S TO AROUND 80...MID 70S TO LOWER
80S ON SATURDAY...MAINLY UPPER 70S TO MID 80S ON SUNDAY AND MONDAY.
LOWS ARE EXPECTED TO BE IN THE UPPER 40S TO UPPER 50S FRIDAY
NIGHT...50S TO AROUND 60 SATURDAY NIGHT...AND MID 50S TO MID 60S
SUNDAY NIGHT.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
SHOWERS AND THUNDERSTORMS WILL BE PRIMARILY CONFINED TO FAR NORTHERN
AREAS LATER TODAY AND TONIGHT AS A COLD FRONT DROPS SOUTH FROM
CANADA. AN ISOLATED THUNDERSTORM IS NOT OUT OF THE QUESTION FURTHER
SOUTH BUT TO LOW OF PROBABILITY TO MENTION IN A TAF. INCREASING
SOUTHWEST WINDS ARE EXPECTED TO RESULT IN DOWNSLOPING IN THE HUDSON
VALLEY WHICH SHOULD ALSO HELP LIMIT CONVECTIVE ACTIVITY FOR MOST OF
THE TAF SITES. THE BEST CHANCE OF THUNDERSTORMS WILL BE AT KGFL LATE
THIS AFTERNOON INTO EARLY THIS EVENING. MODELS SHOW MOST CONVECTION
DYING OUT OVERNIGHT BUT SOME ISOLATED RAIN SHOWERS AND FOG AND
STRATO CU EXPECTED AS MOISTURE POOLS AHEAD OF COLD FRONT. FOR
TOMORROW...COLD FRONT CONTINUES TO MOVE SOUTH WITH BEST CHANCE OF
THUNDERSTORMS OVER SOUTHERN AREAS AS COLD FRONT CONTINUES SOUTH.
SOUTHWEST WINDS 10 TO 15 KTS BY AFTERNOON SUBSIDING TO 3 TO 6 KTS
THIS EVENING. FOR WEDNESDAY...WINDS WEST TO NORTHWEST BECOMING
NORTHWEST TO NORTH AT 5 TO 10 KTS.
OUTLOOK...
WED...VFR/MVFR. SCT SHOWERS/TSTMS.
THU..NO SIG WX.
FRI-SUN...VFR...SLIGHT CHC ISOLD AFTERNOON TSTM.
&&
.FIRE WEATHER...
A HOT AND HUMID AIR MASS WILL LINGER ACROSS THE REGION TODAY. A COLD
FRONT WILL SAG SLOWLY SOUTH FROM THE SAINT LAWRENCE VALLEY THIS
EVENING...REACHING THE MOHAWK VALLEY WEDNESDAY MORNING...AND THE
LONG ISLAND SOUND BY WEDNESDAY EVENING. HIGH PRESSURE WILL BUILD
FROM HUDSON`S VALLEY LATE WEDNESDAY INTO THE WEEKEND.
RELATIVE HUMIDITY VALUES WILL INCREASE TO 80 TO 100 PERCENT
TONIGHT..AND RECOVER TO 40-60 PERCENT WEDNESDAY AFTERNOON. VALES
WEDNESDAY WILL INCREASE TO 60-80 PERCENT.
SOUTHWEST WINDS 10 TO 15 MPH WITH HIGHER GUSTS WILL BECOME LIGHT
AND VARIABLE TONIGHT AT 10 MPH OR LESS...AND INCREASE FROM THE
WEST NORTHWEST TO 5 TO 15 MPH ON WEDNESDAY.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED ON THE MAIN STEM RIVERS OVER THE
NEXT 5 DAYS.
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A FRONTAL PASSAGE
TONGIHT INTO WEDNESDAY WILL PRODUCE SOME HEAVY RAINFALL DUE TO A
SHORT PERIOD OF ANOMALOUSLY HIGH PRECIPITABLE WATER VALUES IN THE
1.5 TO 2 INCH RANGE. SOME PONDING OF WATER ON ROADWAYS OR POOR
DRAINAGE FLOODING IS POSSIBLE...ESPECIALLY ON WEDNESDAY. ZONAL
FLASH FLOOD GUIDANCE VALUES REMAIN HIGH FOR MID JULY. THE
POTENTIAL FOR FLASH FLOODING IS LOW AT THIS TIME IN THE ALY HYDRO
SERVICE AREA.
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...SNYDER
NEAR TERM...SNYDER
SHORT TERM...SNYDER
LONG TERM...11
AVIATION...11
FIRE WEATHER...SNYDER
HYDROLOGY...WASULA/SNYDER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
345 PM EDT TUE JUL 17 2012
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 343 PM EDT TUE JUL 17 2012
COLD FRONT IS WELL TO THE SOUTH OF UPPER MICHIGAN AS PORTIONS OF
SOUTHERN WICSONSIN AND LOWER MICHIGAN CONTINUE TO BAKE. YET...DRY
DAY THAT WAS SUPPOSED TO BE OVER MOST OF THE AREA HAS HAD TOUGH TIME
TAKING SHAPE. MAIN CULPRIT FOR THE SHRA CURRENTLY ROAMING CNTRL UPR
MICHIGAN SEEMS TO HAVE BEEN A SUBTLE H6-H5 JET STREAK ALONG WITH
RIBBON OF LINGERING HIGHER H7 DWPNTS ACROSS THE AREA. ADDITIONAL
LIFT IS PROVIDED BY A WEAK SHORTWAVE NOW PUSHING INTO WESTERN LK
SUPERIOR. BULK OF ANY TSRA HAVE STAYED OVR NORTHERN WISCONSIN ALONG
NORTH EDGE OF 1-6KM MUCAPE GRADIENT. SHRA IN THE NORTH HAVE NOT
BEEN ALL THAT HEAVY...WITH ONLY A FEW HUNDREDTHS OBSERVED AT RAIN
GAGES OVR WESTERN UPR MICHIGAN THIS AFTN. EXPECT ALL THE MENTIONED
FORCING MECHANISMS TO DRIFT SOUTH OUT OF THE AREA EARLY THIS EVENING
AND HAVE PUT AN END TO POPS AT THAT TIME. RAPID REFRESH RUC MODEL
/HRRR/ WHICH DID NOT DO WELL SHOWING THE SHRA/TSRA FOR MUCH OF THE
MORNING FINALLY CAUGHT ON BY EARLY THIS AFTN...AND FCSTS A SIMILAR
FATE TO PRECIP THIS EVENING.
CLEARING SKIES THEN EXPECTED FM NORTHWEST TO SOUTHEAST THROUGH THE
EVENING. THINK THE CLEARING COULD LEAD TO FOG OVERNIGHT TONIGHT
THROUGH EARLY WEDNESDAY MORNING. PLUSES FOR FOG FORMATION ARE ADDED
SFC MOISTURE FROM THE RAIN TODAY/MINIMAL MIXING OR DRYING TODAY
ALONG WITH FAIRLY LIGHT WINDS/COOLING TEMPS. BEST CHANCE FOR FOG
WILL BE OVER WEST HALF AND ALSO WHERE NORTHEAST WINDS UPSLOPE
/HIGHER TERRAIN OF WEST AND NORTH CENTRAL/. LOOKS LIKE AM ON MY
OWN ON THIS ONE THOUGH AS NO GUIDANCE HAS REALLY ANY HINT OF FOG
TONIGHT. GIVEN THOSE SIGNALS...IT IS TOUGH TO GO WITH ANYTHING MORE
THAN PATCHY FOG AT THIS POINT.
IF ANY FOG/STRATUS DEVELOPS TONIGHT IT WILL DEPART SHORTLY AFTER
SUNRISE ON WEDNESDAY MORNING SINCE IT WILL SFC BASED/SHALLOW. WITH
MAINLY SUNNY SKIES FOR THE AFTN HIGH TEMPS SHOULD RISE WELL INTO
THE 70S MOST AREAS WITH EVEN SOME LOWER 80S POSSIBLE TOWARD THE
WISCONSIN BORDER. DAYTIME MIXING WILL RESULT IN LESS HUMID
CONDITIONS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 343 PM EDT TUE JUL 17 2012
AREA WILL BE BETWEEN TWO UPPER TROUGHS ON WED NIGHT...ONE OVER
QUEBEC AND THE OTHER OVER THE PAC NW. THIS WILL LEAD TO A RIDGE
OVER THE NRN PLAINS AND CANADIAN PRAIRIES THAT WILL TRY TO PUSH
EAST TOWARDS THE CWA...BUT WILL BE HELD OFF REINFORCING NRN STREAM
WAVES ATTEMPTING TO KEEP THE UPPER TORUGH OVER QUEBEC. THIS WILL
PUT THE CWA ON THE EDGE OF THE WARM TEMPS THIS WEEKEND...UNTIL THE
UPPER RIDGE FINALLY MOVES OVERHEAD DURING THE BEGINNING OF NEXT
WEEK.
CANADIAN HIGH PRESSURE RIDGE WILL BE OVER UPPER MI ON WED NIGHT AND
THEN GRADUALLY SHIFT SOUTHEAST THROUGH THE REST OF THE WORK WEEK AS
THE TROUGH OVER QUEBEC MOVES INTO THE NEW ENGLAND STATES. MODELS
CONSISTENT ON A SHORTWAVE SLIDING THROUGH THE FLOW ON WED NIGHT INTO
THURS...BUT VARY CONSIDERABLY ON THE LOCATION/INTENSITY. ECMWF IS
THE FARTHEST N AND STRONGEST WITH THE LLVL WAA OVER NRN WI...WHILE
THE REST OF THE MODELS ARE MUCH WEAKER WITH THE WAA AND FARTHER SW.
DRY AIR DOES TRY TO BREAK DOWN THE MOISTURE IN THE MID LVLS OVER THE
SW HALF OF THE CWA WED NIGHT INTO THURS MORNING...BEFORE DIMINISHING
IN THE AFTN. LLVL DRY AIR WILL LIKELY KEEP IT MID CLOUDS AND WITH
THE BEST FORCING LIKELY STAYING TO THE S...WANTED TO KEEP POPS
IN NRN WI. BUT WITH 12Z ECMWF CONTINUING TO SHOW PCPN MAKING IT
INTO UPPER MI...WILL CONTINUE MENTION SLIGHT CHANCES JUST OVER
THE WI BORDER.
OTHERWISE...HIGH PRESSURE RIDGE AND DRY CANADIAN AIR WILL KEEP THE
AREA MOSTLY/PARTLY CLEAR INTO FRI. TEMPS WILL BE SLIGHTLY ABOVE
NORMAL ON THURS AND THEN WARM SLIGHTLY ON FRI...AS WARM AIR ALOFT
STARTS TO WORK E AND BACK OVER THE CWA.
NRN STREAM WAVE SLIDING THROUGH CNTRL CANADA FRI NIGHT AND INTO NRN
ONTARIO WILL TRY TO PUSH A COLD FRONT TOWARDS THE AREA ON SAT INTO
SUN. IT ACTUALLY MOVES INTO NRN MN ON FRI...BUT STALLS AS IT
RUNS INTO THE SFC HIGH OVER UPPER MI. WITH IT BEING A GOOD WAYS AWAY
FROM IT/S SOURCE...AND LIMITED CONVERGENCE...EXPECT PCPN TO BE
SCATTERED ALONG THE FRONT. THUS...WILL CONTINUE TO MENTION SLIGHT
AND LOW CHANCE POPS FRI NIGHT INTO SUN. FRONT FINALLY SLIDES S OF
THE AREA ON SUN NIGHT AND WILL END PCPN CHANCE AT THAT POINT.
UPPER RIDGE THEN REALLY BUILDS IN MON/TUES AS ANOTHER CANADIAN HIGH
PRESSURE RIDGE SLIDES INTO THE AREA. THERE ARE A FEW
WEAK SHORTWAVES TRYING TO ROUND THE RIDGE...BUT WITH LITTLE
TO NO INSTABILITY...WILL KEEP THE FORECAST DRY FOR MON AND
MON NIGHT. ANOTHER COLD FRONT WILL LIKELY APPROACH THE UPPER GREAT
LAKES LATE TUES AFTN AND INTO WED...SO HAVE BROUGHT IN CHANCES
OVER THE WEST. HIGHS ARE STILL EXPECTED TO BE ABOVE NORMAL THROUGH
THE PERIOD...IN THE 80S AND LOW 90S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 156 PM EDT TUE JUL 17 2012
CIGS LIFTING LAST FEW HOURS AND EXPECT SLOW IMPROVEMENT THROUGH REST
OF AFTN. AREA OF LGT SHRA IMPACTS KIWD VERY EARLY THIS AFTN WITH SCT
SHRA IMPACTING KSAW THROUGH LATE AFTN. GENERALLY EXPECT SHRA TO MISS
KCMX TO SOUTH. BECOMING CONCERNED MAY SEE FOG WITH LOW VSBY/CIGS
TONIGHT WITH ADDED MOISTURE FM SHOWERS TODAY AND AS NIGHTTIME COOLING
OCCURS SETTING UP SFC BASED INVERSION. BEST CHANCE FOR FOG WILL BE AT
KSAW WITH IDEAL UPSLOPE LOW-LEVELS WIND FCST. THINKING THERE
CERTAINLY IS POTENTIAL FOR CONDITIONS TO FALL BLO ALTERNATE MINS
OVERNIGHT TONIGHT. TAF ONLY SHOWS MVFR RIGHT NOW...BUT MAY NEED TO
UPDATE THIS LATER THIS AFTN. ELSEWHERE...LIGHTER FOG IS POSSIBLE AS
WINDS ARE NOT AS FAVORABLE FOR UPSLOPE. IF WINDS BECOME LIGHT ENOUGH
THOUGH...COULD SEE PATCHY DENSE FOG AT KIWD AND KCMX AS WELL. VFR
CONDITIONS EXPECTED AFTER ANY LOW CLOUDS/FOG DIMINISH ON WEDNESDAY
MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 343 PM EDT TUE JUL 17 2012
HIGH PRES BUILDING S TOWARD THE UPPER LAKES WILL ARRIVE IN FULL
FORCE LATE TONIGHT INTO WEDNESDAY. THE HIGH WILL REMAIN OVERHEAD
THROUGH THE UPCOMING WEEKEND...SO WINDS WILL BE ON THE LIGHT SIDE...
MAINLY LESS THAN 15 KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...SRF
AVIATION...JLA
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
157 PM EDT TUE JUL 17 2012
.UPDATE...
ISSUED AT 1212 PM EDT TUE JUL 17 2012
FOG/DRIZZLE IS ALL BUT GONE AS DRIER AIR IS TRYING TO WORK IN FM
NORTH. PRETTY CLEAR OVR MUCH OF NORTHERN AND EASTERN LK SUPERIOR AS
OF NOON. MAIN ISSUE WITH THE FCST IS WHAT TO DO WITH COMPLEX OF SHRA
AND ISOLD TSRA PUSHING ACROSS NORTHWEST WISCONSIN. MAJORITY OF
MODELS HAVE REALLY MISSED THIS AREA OF SHRA. RUC AND SREF DO HAVE
SOME CLUE WITH IT AND INDICATE WEST AND SOUTHWEST CWA BEING
IMPACTED MOST THROUGH THE AFTN...WHICH MATCHES CURRENT RADAR TRENDS
WELL. STARTED TO SEE SIGNS OF MOST TSRA STAYING SOUTH OF WI
BORDER...SO WILL CONTINUE TO CUT BACK ON THOSE CHANCES. LOW CLOUDS
MAY HANG AROUND THROUGH GOOD PART OF AFTN WHERE NORTH/NORTHEAST
WINDS ACROSS LK SUPERIOR IS RESULTING IN UPSLOPE LIFTING. FAR WEST
AND NORTH CNTRL APPEAR MOST PRONE TO LINGERING LOW CLOUDS. DUE TO THE
PERSISTENT ONSHORE FLOW AND CLOUDS...TWEAKED TEMPS DOWN SOME IN THE
NORTH. MOST AREAS WILL END UP IN THE 70S FOR THE AFTN.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 512 AM EDT TUE JUL 17 2012
MAIN FCST CONCERN IN THE SHORT TERM WILL BE PCPN CHANCES. WATER
VAPOR IMAGERY AND RUC ANALYSIS SHOW CNTRL CONUS RIDGE LOSING SOME
AMPLITUDE AS A BROAD TROF SETTLES INTO SE CANADA. ALTHOUGH COLD
FRONT ASSOCIATED WITH SE CANADA TROF IS DROPPING S THRU UPPER
MI...VERY LITTLE CONVECTION HAS OCCURRED IN THE VCNTY OF IT. LITTLE
FORCING IN THE PRESENCE OF WARM MID LEVEL TEMPS PER 00Z KINL/KGRB
SOUNDINGS HAS BEEN WORKING AGAINST SHRA/TSRA DEVELOPMENT SO FAR.
SOUTHWARD MOVING COLD FRONT SHOULD HAVE CLEARED ALL OF THE FCST AREA
AT 12Z THIS MORNING...EXCEPT THE FAR SCNTRL AROUND KMNN. WITH FRONT
CONTINUING TO SETTLE S TODAY...IT WOULD APPEAR THERE IS LITTLE RISK
OF PCPN. HOWEVER...SUBTLE SHORTWAVE CURRENTLY ASSOCIATED WITH
CONVECTION IN NRN SD WILL BE TRACKING E AND COULD PROVIDE LIFT OVER
THE SFC BOUNDARY...POSSIBLY RESULTING IN SOME SHRA ACROSS THE AREA
THIS MORNING AND THEN ACROSS THE SCNTRL THIS AFTN. POTENTIAL FOR
TSRA WILL BE DIMINISHING WITH TIME AS INSTABILITY WEAKENS PER NAM
MLCAPE PROGS. OTHER ISSUE TODAY IS FOG. QUITE A BIT OF FOG/STRATUS
HAS PLAGUED LAKE SUPERIOR OVER THE LAST COUPLE OF DAYS. THAT MAY
STILL BE THE CASE. UNFORTUNATELY...STRATOCU IS OBSCURING A BETTER
LOOK BELOW ON 11-3.9MICRON SATELLITE IMAGERY. WHETHER OR NOT THERE
IS FOG ON THE LAKE...WITH A STEADY NRLY FLOW PUSHING MARINE LAYER
INLAND/UPSLOPE EARLY THIS MORNING...WILL ASSUME THERE COULD BE SOME
FOG...ESPECIALLY OVER THE HIGHER TERRAIN AS THE COOLER AIR
ENCOUNTERS INITIALLY HIGHER DWPTS.
WHILE A SHRA MAY LINGER OVER THE FAR SCNTRL EARLY THIS EVENING...DRY
WEATHER SHOULD RULE TONIGHT AS SFC HIGH PRES BUILDS S. HOWEVER...IT
IS NOTED THAT SOME OF THE GLOBAL MODELS DO SHOW PCPN BRUSHING THE SW
FCST AREA DURING THE NIGHT...A RESULT OF WEAK WAA OVER SFC COLD
FRONT THAT PASSED TODAY. BASED ON LOCATION OF SFC/850MB FRONTS IN
THOSE MODELS...IT APPEARS PCPN IS BEING GENERATED TOO FAR TO THE NE.
NONETHELESS...IT WILL BE SOMETHING TO KEEP IN MIND FOR LATER
FORECASTS. IT WILL BE A MUCH MORE COMFORTABLE NIGHT FOR SLEEPING AS
TEMPS DROP INTO THE 50S AWAY FROM THE LAKESHORES. DEPENDING ON SKY
COVER...TEMPS IN THE TRADITIONAL COOL SPOTS COULD SLIP INTO THE
UPPER 40S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 512 AM EDT TUE JUL 17 2012
WEDNESDAY THROUGH FRIDAY...AS THE UPPER LEVEL LOW CENTERED OVER
NORTHERN QUEBEC SHIFTS SLOWLY TO THE SOUTHEAST WEDNESDAY...A HIGH
PRESSURE RIDGE ORIENTED FROM NORTH TO SOUTH OVER MANITOBA INTO THE
NORTHERN PLAINS WILL BEGIN TO BUILD EASTWARD INTO MUCH OF THE UPPER
GREAT LAKES REGION THROUGH MUCH OF THE DAY FRIDAY. THIS WILL ALLOW A
SURFACE RIDGE OVER CENTRAL CANADA TO EXPAND SOUTH AND EASTWARD
ENCOMPASSING MUCH OF THE GREAT LAKES REGION THROUGH FRIDAY
AFTERNOON. THE HIGH PRESSURE RIDGE ALONG WITH LITTLE MOISTURE SHOULD
HELP KEEP MOST OF THE UPPER PENINSULA DRY THROUGH THIS TIME PERIOD
WITH THE EXCEPTION OF WEDNESDAY NIGHT INTO EARLY THURSDAY ALONG THE
WISCONSIN BORDER AS MANY OF THE MODELS BRING A SHORTWAVE THROUGH THE
AREA AROUND THIS TIME. AS PREVIOUS SHIFT MENTIONED COOLEST
TEMPERATURES WILL LIKELY BE WEDNESDAY AS THE HIGHER HEIGHTS
ASSOCIATED WITH THE RIDGE SHOULD HOLD OFF UNTIL LATER IN THE
WEEK...ALLOWING FOR A GRADUAL WARMING TREND THURSDAY AND
FRIDAY...BEFORE WARMING MORE RAPIDLY OVER THE WEEKEND.
FRIDAY NIGHT THROUGH MONDAY...AS UPPER LEVEL TROUGHING BEGINS TO
MOVE INTO THE PACIFIC NORTHWEST THROUGH FRIDAY AFTERNOON...EXPECT
THE UPPER LEVEL RIDGE SHOWN AT H500 TO INTENSIFY. THIS SHOULD HELP
TO INCREASE TEMPERATURES ACROSS THE REGION THROUGH THE WEEKEND INTO
THE FIRST PART OF NEXT WEEK. AT THIS POINT THE WARMEST TEMPERATURES
WILL LIKELY MOVE INTO THE REGION OVER THE WEEKEND WITH TEMPERATURES
APPROACHING OR EXCEEDING THE 90 DEGREE MARK. BY MONDAY THE GFS AND
EC ARE IN AGREEMENT THAT THE UPPER LEVEL TROUGH OVER THE PACIFIC
NORTHWEST WILL SHIFT TO NORTHERN MANITOBA...WHICH SHOULD HELP TO
WEAKEN THE RIDGE THROUGH OUT THE DAY...KEEPING TEMPERATURES SLIGHTLY
COOLER. THERE ARE A FEW CHANCES OF SHOWERS AND THUNDERSTORMS THROUGH
THIS PERIOD AS SEVERAL SHORT WAVES ROTATE AROUND THE RIDGE. THE BEST
CHANCE OF PRECIPITATION WOULD LIKELY BE FRIDAY NIGHT INTO SATURDAY
AS ONE OF THE WAVES PASS THROUGH AND THEN AGAIN SUNDAY NIGHT INTO
EARLY MONDAY AS THE NEXT WAVE AN ASSOCIATED WEAK COLD FRONT MOVE
INTO THE AREA. ONE LIMITING FACTOR FOR EACH SHORTWAVE WILL LIKELY BE
THE LACK OF MOISTURE AVAILABLE. WINDS SHOULD REMAIN FAIRLY WEAK AND
A MAJORITY OF THE ISOBARS ARE CLOSED TO THE GULF...WHICH INDICATES A
REDUCTION IN THE AMOUNT OF MOISTURE TRANSPORT INTO THE REGION. AN
ADDITIONAL LIMITING FACTOR FOR THE SHORTWAVE MOVING INTO THE REGION
SUNDAY NIGHT INTO MONDAY WILL BE THE PRESENCE OF A LARGE CAP WITH
H850 TEMPS PROGGED TO BE AOA 21 DEGREES CELSIUS...SO ANY STORM
DEVELOPMENT MAY BE CONFINED ALONG THE COLD FRONT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 156 PM EDT TUE JUL 17 2012
CIGS LIFTING LAST FEW HOURS AND EXPECT SLOW IMPROVEMENT THROUGH REST
OF AFTN. AREA OF LGT SHRA IMPACTS KIWD VERY EARLY THIS AFTN WITH SCT
SHRA IMPACTING KSAW THROUGH LATE AFTN. GENERALLY EXPECT SHRA TO MISS
KCMX TO SOUTH. BECOMING CONCERNED MAY SEE FOG WITH LOW VSBY/CIGS
TONIGHT WITH ADDED MOISTURE FM SHOWERS TODAY AND AS NIGHTTIME COOLING
OCCURS SETTING UP SFC BASED INVERSION. BEST CHANCE FOR FOG WILL BE AT
KSAW WITH IDEAL UPSLOPE LOW-LEVELS WIND FCST. THINKING THERE
CERTAINLY IS POTENTIAL FOR CONDITIONS TO FALL BLO ALTERNATE MINS
OVERNIGHT TONIGHT. TAF ONLY SHOWS MVFR RIGHT NOW...BUT MAY NEED TO
UPDATE THIS LATER THIS AFTN. ELSEWHERE...LIGHTER FOG IS POSSIBLE AS
WINDS ARE NOT AS FAVORABLE FOR UPSLOPE. IF WINDS BECOME LIGHT ENOUGH
THOUGH...COULD SEE PATCHY DENSE FOG AT KIWD AND KCMX AS WELL. VFR
CONDITIONS EXPECTED AFTER ANY LOW CLOUDS/FOG DIMINISH ON WEDNESDAY
MORNING. &&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 512 AM EDT TUE JUL 17 2012
FOG HAD BEEN AN ISSUE OVER THE LAST COUPLE OF DAYS. HOWEVER...BASED
ON A FEW SHIP OBS OVERNIGHT...IT APPEARS FOG HAS EITHER DISSIPATED
OR COVERAGE HAS BECOME PATCHY. WILL KEEP A MENTION OF PATCHY FOG IN
THE MORNING. OTHERWISE...AN EXTENDED PERIOD OF GOOD VIS IS SETTING
UP AS DRIER AIR WORKS INTO THE AREA FOR SEVERAL DAYS.
AS FOR WINDS...WITH HIGH PRES BUILDING S TOWARD THE UPPER LAKES
TODAY AND THEN DOMINATING THE AREA THRU FRI...WINDS WILL BE ON THE
LIGHT SIDE. THE STRONGEST WINDS (UP AROUND 15KT) WILL OCCUR TODAY AS
THE HIGH BUILDS S TOWARD THE AREA. LOCALLY HIGHER WINDS...AGAIN UP
AROUND 15KT...WILL OCCUR WED OVER THE W AND ALSO OVER THE FAR ERN
PORTION OF THE LAKE AS MESO HIGH DEVELOPS OVER CNTRL LAKE SUPERIOR.
WINDS THU/FRI SHOULD BE 10KT OR LESS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SHORT TERM...ROLFSON
LONG TERM...KEC
AVIATION...JLA
MARINE...ROLFSON
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
1213 PM EDT TUE JUL 17 2012
.UPDATE...
ISSUED AT 1212 PM EDT TUE JUL 17 2012
FOG/DRIZZLE IS ALL BUT GONE AS DRIER AIR IS TRYING TO WORK IN FM
NORTH. PRETTY CLEAR OVR MUCH OF NORTHERN AND EASTERN LK SUPERIOR AS
OF NOON. MAIN ISSUE WITH THE FCST IS WHAT TO DO WITH COMPLEX OF SHRA
AND ISOLD TSRA PUSHING ACROSS NORTHWEST WISCONSIN. MAJORITY OF
MODELS HAVE REALLY MISSED THIS AREA OF SHRA. RUC AND SREF DO HAVE
SOME CLUE WITH IT AND INDICATE WEST AND SOUTHWEST CWA BEING
IMPACTED MOST THROUGH THE AFTN...WHICH MATCHES CURRENT RADAR TRENDS
WELL. STARTED TO SEE SIGNS OF MOST TSRA STAYING SOUTH OF WI
BORDER...SO WILL CONTINUE TO CUT BACK ON THOSE CHANCES. LOW CLOUDS
MAY HANG AROUND THROUGH GOOD PART OF AFTN WHERE NORTH/NORTHEAST
WINDS ACROSS LK SUPERIOR IS RESULTING IN UPSLOPE LIFTING. FAR WEST
AND NORTH CNTRL APPEAR MOST PRONE TO LINGERING LOW CLOUDS. DUE TO THE
PERSISTENT ONSHORE FLOW AND CLOUDS...TWEAKED TEMPS DOWN SOME IN THE
NORTH. MOST AREAS WILL END UP IN THE 70S FOR THE AFTN.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 512 AM EDT TUE JUL 17 2012
MAIN FCST CONCERN IN THE SHORT TERM WILL BE PCPN CHANCES. WATER
VAPOR IMAGERY AND RUC ANALYSIS SHOW CNTRL CONUS RIDGE LOSING SOME
AMPLITUDE AS A BROAD TROF SETTLES INTO SE CANADA. ALTHOUGH COLD
FRONT ASSOCIATED WITH SE CANADA TROF IS DROPPING S THRU UPPER
MI...VERY LITTLE CONVECTION HAS OCCURRED IN THE VCNTY OF IT. LITTLE
FORCING IN THE PRESENCE OF WARM MID LEVEL TEMPS PER 00Z KINL/KGRB
SOUNDINGS HAS BEEN WORKING AGAINST SHRA/TSRA DEVELOPMENT SO FAR.
SOUTHWARD MOVING COLD FRONT SHOULD HAVE CLEARED ALL OF THE FCST AREA
AT 12Z THIS MORNING...EXCEPT THE FAR SCNTRL AROUND KMNN. WITH FRONT
CONTINUING TO SETTLE S TODAY...IT WOULD APPEAR THERE IS LITTLE RISK
OF PCPN. HOWEVER...SUBTLE SHORTWAVE CURRENTLY ASSOCIATED WITH
CONVECTION IN NRN SD WILL BE TRACKING E AND COULD PROVIDE LIFT OVER
THE SFC BOUNDARY...POSSIBLY RESULTING IN SOME SHRA ACROSS THE AREA
THIS MORNING AND THEN ACROSS THE SCNTRL THIS AFTN. POTENTIAL FOR
TSRA WILL BE DIMINISHING WITH TIME AS INSTABILITY WEAKENS PER NAM
MLCAPE PROGS. OTHER ISSUE TODAY IS FOG. QUITE A BIT OF FOG/STRATUS
HAS PLAGUED LAKE SUPERIOR OVER THE LAST COUPLE OF DAYS. THAT MAY
STILL BE THE CASE. UNFORTUNATELY...STRATOCU IS OBSCURING A BETTER
LOOK BELOW ON 11-3.9MICRON SATELLITE IMAGERY. WHETHER OR NOT THERE
IS FOG ON THE LAKE...WITH A STEADY NRLY FLOW PUSHING MARINE LAYER
INLAND/UPSLOPE EARLY THIS MORNING...WILL ASSUME THERE COULD BE SOME
FOG...ESPECIALLY OVER THE HIGHER TERRAIN AS THE COOLER AIR
ENCOUNTERS INITIALLY HIGHER DWPTS.
WHILE A SHRA MAY LINGER OVER THE FAR SCNTRL EARLY THIS EVENING...DRY
WEATHER SHOULD RULE TONIGHT AS SFC HIGH PRES BUILDS S. HOWEVER...IT
IS NOTED THAT SOME OF THE GLOBAL MODELS DO SHOW PCPN BRUSHING THE SW
FCST AREA DURING THE NIGHT...A RESULT OF WEAK WAA OVER SFC COLD
FRONT THAT PASSED TODAY. BASED ON LOCATION OF SFC/850MB FRONTS IN
THOSE MODELS...IT APPEARS PCPN IS BEING GENERATED TOO FAR TO THE NE.
NONETHELESS...IT WILL BE SOMETHING TO KEEP IN MIND FOR LATER
FORECASTS. IT WILL BE A MUCH MORE COMFORTABLE NIGHT FOR SLEEPING AS
TEMPS DROP INTO THE 50S AWAY FROM THE LAKESHORES. DEPENDING ON SKY
COVER...TEMPS IN THE TRADITIONAL COOL SPOTS COULD SLIP INTO THE
UPPER 40S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 512 AM EDT TUE JUL 17 2012
WEDNESDAY THROUGH FRIDAY...AS THE UPPER LEVEL LOW CENTERED OVER
NORTHERN QUEBEC SHIFTS SLOWLY TO THE SOUTHEAST WEDNESDAY...A HIGH
PRESSURE RIDGE ORIENTED FROM NORTH TO SOUTH OVER MANITOBA INTO THE
NORTHERN PLAINS WILL BEGIN TO BUILD EASTWARD INTO MUCH OF THE UPPER
GREAT LAKES REGION THROUGH MUCH OF THE DAY FRIDAY. THIS WILL ALLOW A
SURFACE RIDGE OVER CENTRAL CANADA TO EXPAND SOUTH AND EASTWARD
ENCOMPASSING MUCH OF THE GREAT LAKES REGION THROUGH FRIDAY
AFTERNOON. THE HIGH PRESSURE RIDGE ALONG WITH LITTLE MOISTURE SHOULD
HELP KEEP MOST OF THE UPPER PENINSULA DRY THROUGH THIS TIME PERIOD
WITH THE EXCEPTION OF WEDNESDAY NIGHT INTO EARLY THURSDAY ALONG THE
WISCONSIN BORDER AS MANY OF THE MODELS BRING A SHORTWAVE THROUGH THE
AREA AROUND THIS TIME. AS PREVIOUS SHIFT MENTIONED COOLEST
TEMPERATURES WILL LIKELY BE WEDNESDAY AS THE HIGHER HEIGHTS
ASSOCIATED WITH THE RIDGE SHOULD HOLD OFF UNTIL LATER IN THE
WEEK...ALLOWING FOR A GRADUAL WARMING TREND THURSDAY AND
FRIDAY...BEFORE WARMING MORE RAPIDLY OVER THE WEEKEND.
FRIDAY NIGHT THROUGH MONDAY...AS UPPER LEVEL TROUGHING BEGINS TO
MOVE INTO THE PACIFIC NORTHWEST THROUGH FRIDAY AFTERNOON...EXPECT
THE UPPER LEVEL RIDGE SHOWN AT H500 TO INTENSIFY. THIS SHOULD HELP
TO INCREASE TEMPERATURES ACROSS THE REGION THROUGH THE WEEKEND INTO
THE FIRST PART OF NEXT WEEK. AT THIS POINT THE WARMEST TEMPERATURES
WILL LIKELY MOVE INTO THE REGION OVER THE WEEKEND WITH TEMPERATURES
APPROACHING OR EXCEEDING THE 90 DEGREE MARK. BY MONDAY THE GFS AND
EC ARE IN AGREEMENT THAT THE UPPER LEVEL TROUGH OVER THE PACIFIC
NORTHWEST WILL SHIFT TO NORTHERN MANITOBA...WHICH SHOULD HELP TO
WEAKEN THE RIDGE THROUGH OUT THE DAY...KEEPING TEMPERATURES SLIGHTLY
COOLER. THERE ARE A FEW CHANCES OF SHOWERS AND THUNDERSTORMS THROUGH
THIS PERIOD AS SEVERAL SHORT WAVES ROTATE AROUND THE RIDGE. THE BEST
CHANCE OF PRECIPITATION WOULD LIKELY BE FRIDAY NIGHT INTO SATURDAY
AS ONE OF THE WAVES PASS THROUGH AND THEN AGAIN SUNDAY NIGHT INTO
EARLY MONDAY AS THE NEXT WAVE AN ASSOCIATED WEAK COLD FRONT MOVE
INTO THE AREA. ONE LIMITING FACTOR FOR EACH SHORTWAVE WILL LIKELY BE
THE LACK OF MOISTURE AVAILABLE. WINDS SHOULD REMAIN FAIRLY WEAK AND
A MAJORITY OF THE ISOBARS ARE CLOSED TO THE GULF...WHICH INDICATES A
REDUCTION IN THE AMOUNT OF MOISTURE TRANSPORT INTO THE REGION. AN
ADDITIONAL LIMITING FACTOR FOR THE SHORTWAVE MOVING INTO THE REGION
SUNDAY NIGHT INTO MONDAY WILL BE THE PRESENCE OF A LARGE CAP WITH
H850 TEMPS PROGGED TO BE AOA 21 DEGREES CELSIUS...SO ANY STORM
DEVELOPMENT MAY BE CONFINED ALONG THE COLD FRONT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 735 AM EDT TUE JUL 17 2012
MOIST UPSLOPE FLOW OFF LAKE SUPERIOR IN THE WAKE OF COLD FRONT WILL
CONTINUE TO RESULT IN IFR/LIFR CIGS FOR THE NEXT SEVERAL HRS AT
KIWD/KCMX/KSAW. WITH MORE DIRECT UPSLOPE FLOW...THE LWR LIFR CIGS
WILL PREVAIL AT KIWD/KSAW. VIS RESTRICTION IN FOG WILL ALSO OCCUR AT
KIWD/KSAW. AS DRIER AIR MAKES INROADS WITH FLOW BECOMING MORE
ANTICYCLONIC...IMPROVEMENT EXPECTED BY THE AFTN (BEGINNING FIRST AT
KCMX) WITH VFR CONDITIONS FROM EARLY AFTN THRU THE END OF THE FCST
PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 512 AM EDT TUE JUL 17 2012
FOG HAD BEEN AN ISSUE OVER THE LAST COUPLE OF DAYS. HOWEVER...BASED
ON A FEW SHIP OBS OVERNIGHT...IT APPEARS FOG HAS EITHER DISSIPATED
OR COVERAGE HAS BECOME PATCHY. WILL KEEP A MENTION OF PATCHY FOG IN
THE MORNING. OTHERWISE...AN EXTENDED PERIOD OF GOOD VIS IS SETTING
UP AS DRIER AIR WORKS INTO THE AREA FOR SEVERAL DAYS.
AS FOR WINDS...WITH HIGH PRES BUILDING S TOWARD THE UPPER LAKES
TODAY AND THEN DOMINATING THE AREA THRU FRI...WINDS WILL BE ON THE
LIGHT SIDE. THE STRONGEST WINDS (UP AROUND 15KT) WILL OCCUR TODAY AS
THE HIGH BUILDS S TOWARD THE AREA. LOCALLY HIGHER WINDS...AGAIN UP
AROUND 15KT...WILL OCCUR WED OVER THE W AND ALSO OVER THE FAR ERN
PORTION OF THE LAKE AS MESO HIGH DEVELOPS OVER CNTRL LAKE SUPERIOR.
WINDS THU/FRI SHOULD BE 10KT OR LESS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SHORT TERM...ROLFSON
LONG TERM...KEC
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
125 PM EDT TUE JUL 17 2012
.SYNOPSIS...
HIGH PRESSURE WILL PREVAIL UNTIL WEDNESDAY...WITH HOT DAYS AND
MUGGY NIGHTS ACROSS THE LOWLANDS. A COLD FRONT SINKS SOUTHEAST
ON THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM UPDATE...DID ELECT TO ADD AT LEAST A SLIGHT CHANCE OF POPS
CWA WIDE THIS AFTERNOON. IN THE MOIST...HUMID...ATMOSPHERE...DONT
FEEL CAN TOTALLY RULE IT OUT DURING PEAK DAYTIME HEATING. IN
ADDITION...NAM SUGGESTING UPPER AIR DISTURBANCES ROUNDING RIDGE
COULD TRIGGER STORMS IN THE EASTERN PARTS OF CWA...ALTHOUGH GREATER
CHANCES EXIST WEST OF THE CWA. ALSO DID BUMP UP MAX TEMPS A DEGREE OR
SO IN A FEW LOCATIONS FOR TODAY BASED ON THE FACT THAT WE ARE
ALREADY SEVERAL DEGREES WARMER IN MANY LOCATIONS THAT THE CURRENT
GUIDANCE WOULD SUGGEST...AND WITH A LACK OF CLOUD COVER THIS
AM...SHOULD GET SOME DECENT HEATING GOING. CURRENT HEAT ADVISORY
LOCATION LOOKS GOOD.
PREVIOUS DISCUSSION FOLLOWS...
HOT AND HUMID AIRMASS MOVING INTO REGION...AS AN UPPER LEVEL
RIDGE BROADENS OVER FORECAST AREA TODAY. WITH ABUNDANT LOW LEVEL
MOISTURE AND GOOD DAYTIME HEATING...EXPECTING ISOLATED CONVECTION
TODAY. NAM DOES KEEP THE BULK OF IT WEST OF THE FORECAST AREA...IN
CENTRAL KY...TIED TO AN UPPER LEVEL DISTURBANCE SLIDING SOUTH
THERE. GFS PAINTS A LITTLE MORE PRECIP INTO THE FORECAST AREA THIS
AFTERNOON...AND RAP SOUNDINGS SHOW MODEST INSTABILITY...SO
EXPANDED THE AREAL COVERAGE OF THE SLIGHT CHANCE POPS A BIT FOR
THIS AFTERNOON...BUT STILL THINK THINGS SHOULD BE MOSTLY ISOLATED.
MODEL GUIDANCE FOR AFTERNOON HIGHS GENERALLY A BIT WARMER THAN
PREVIOUS FORECAST...SO BUMPED UP HIGHS A BIT. COMBINED WITH
DEWPOINTS CLIMBING INTO THE 70S...THIS PRODUCED HEAT INDEX VALUES
AROUND TO JUST ABOVE 100 DEGREES ALONG AND WEST OF THE OHIO RIVER.
ISSUED HEAT ADVISORY FOR THESE AREAS. EXPECTING A MUGGY NIGHT
TONIGHT WITH TEMPS ONLY DROPPING INTO THE LOW 70S ACROSS MUCH OF THE
LOWLANDS. MOST GUIDANCE VERY CLOSE FOR LOWS TONIGHT...SO BLENDED IN
NEW 00Z MOS.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
5H RIDGE IN PLACE AS TROUGH SAGS ACROSS EASTERN CANADA THROUGH THE
PERIOD. BAROCLINIC ZONE WILL BE DRAPED ACROSS THE GREAT LAKES AND
WILL SLOWLY NUDGE SOUTHWARD WITH TIME. THIS LEADS TO MOISTENING AND
DESTABILIZATION OF THE ATMOSPHERIC COLUMN LATE WEDNESDAY NIGHT INTO
THURSDAY. THUS HAVE NUDGED POP VALUES HIGHER TO ACCOUNT FOR INCREASE
IN MOISTURE.
MODELS GENERALLY AGREE WITH IDEA OF SLOWLY TRANSITIONING THE FRONT
INTO CWA WED NIGHT...WITH BOUNDARY STAYING TO OUR SOUTH INTO
FRIDAY. THIS SHOULD LEAD TO A PERIOD OF UNSETTLED WEATHER...
ESPECIALLY IN THE AFTERNOON WHEN BOUNDARY LAYER HEATING IS
MAXIMIZED. FOR TEMPS...USED MAINLY INHERITED VALUES WITH MINOR
CHANGES BASED ON LATEST MOS GUIDANCE.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
DRIER AIR WILL MOVE INTO THE CWA FOR FRIDAY BEHIND THE FRONT...WITH
A NORTHWESTERLY FLOW PATTERN ALOFT SETTING UP ACROSS THE CWA...AND
COOLER WEATHER TAKING HOLD. STILL LOOKING AT A CHANCE FOR SHOWERS
AND THUNDERSTORMS IN THE EXTENDED AS WEAK RIPPLES IN THE FLOW WILL
KEEP A MENTION...ESPECIALLY DOWN SOUTH WHERE BETTER MOISTURE WILL
EXIST. TEMPERATURES WILL BEGIN TO WARM BY THE WEEKEND AS HIGH OVER
CENTRAL U.S. BUILDS EAST.
&&
.AVIATION /17Z TUESDAY THROUGH SATURDAY/...
18Z TUESDAY THROUGH 18Z WEDNESDAY...
MAINLY VFR CONDITIONS FOR THE PERIOD. SCATTERED SHOWERS AND
THUNDERSTORMS ARE DEVELOPING ON RADAR...AND ARE EXPECTED TO
CONTINUE THROUGH ABOUT 02Z...WHEN LOSS OF DAYTIME HEATING ALLOWS
THEM TO DISSIPATE. GREATEST CHANCE FOR CONVECTION IS IN SOUTHEAST
OHIO...EASTERN KENTUCKY...AND SOUTHERN WV. EXPECT BRIEF HEAVY
DOWNPOURS AND GUSTY WINDS IN VICINITY OF STORMS. ALSO...BRIEF MVFR
CONDITIONS ARE ALSO POSSIBLE IN VICINITY OF STORMS.
STORMS WILL DISSIPATE AFTER 02Z. CLOUDS WILL BE ON THE INCREASE
OVERNIGHT IN ADVANCE OF A COLD FRONT...PROGGED TO MOVE INTO THE
AREA WEDNESDAY NIGHT. INCREASING CLOUDS SHOULD HELP TO PREVENT
WIDESPREAD FOG FORMATION TONIGHT...HOWEVER...PATCHY IFR/MVFR FOG
IS STILL EXPECTED IN FAVORED MOUNTAIN/RIVER VALLEYS. ANY FOG THAT
DOES DEVELOP WILL DISSIPATE AFTER 13Z. OTHERWISE...SHOWERS AND
STORMS WILL BE ON THE INCREASE AFTER 14Z IN ADVANCE OF THE
APPROACHING COLD FRONT. EXPECT HEAVY DOWNPOURS...BRIEF GUSTY
WINDS...AND MVFR/IFR CONDITIONS IN VICINITY OF STORMS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: IF CLOUDS SLOWER TO ENTER AREA
TONIGHT...COULD SEE MORE WIDESPREAD FOG DEVELOP.
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.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z WEDNESDAY...
MORE WIDESPREAD CONVECTION EXPECTED WEDNESDAY AFTERNOON AND
NIGHT AND AGAIN ON THURSDAY AND THURSDAY NIGHT...WITH IFR IN HEAVIER
SHOWERS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR WVZ005>011-014.
OH...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR OHZ066-067-075-
076-083>087.
KY...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR KYZ101-103.
VA...NONE.
&&
$$
SYNOPSIS...MZ
NEAR TERM...MZ/SL
SHORT TERM...KMC
LONG TERM...SL
AVIATION...SL
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
336 PM CDT TUE JUL 17 2012
.SHORT TERM...
PRECIPITATION THIS MORNING WAS NOT AS EXTENSIVE AS YESTERDAY AND WAS
ALSO LIMITED TO NEAR THE TX/NM STATE LINE. 12Z MODELS WERE NOT
GENERATING MUCH PRECIPITATION AS WELL WITH THE NAM BEING THE ONLY
MODEL WITH POPS OVER PORTIONS OF THE FORECAST AREA. HRRR RUNS THROUGH
14Z WERE ALSO NOT BREAKING OUT PRECIPITATION OVER THE REGION BUT THE
LATEST RUNS SINCE 15Z ARE SHOWING SOME CONVECTION OVER THE ROLLING
PLAINS WHILE LEAVING THE SOUTH PLAINS HIGH AND DRY. HARD TO TELL
HOW THINGS WILL PLAY OUT AS WV SATELLITE LOOP SHOWS DRIER AIR
PUSHING INTO THE REGION ALOFT AND MODELS INDICATE CAP HAS
STRENGTHENED JUST A BIT AS WELL. WILL KEEP BEST CHANCES FOR PRECIP
TONIGHT NEAR THE STATE LINE WHICH IS CLOSER TO THE MID-LEVEL
MOISTURE AXIS AND BETTER LAPSE RATES. ONE OTHER ISSUE IS THE
UPPER-LEVEL LOW WHICH IS STARTING TO SLOWLY DRIFT TO THE NORTHWEST
OVER THE LAST COUPLE OF HOURS. DEPENDING ON HOW CLOSE THIS GETS TO
THE REGION...THIS MAY HELP INITIATE A FEW STORMS LATER THIS
EVENING. AS A RESULT...WILL KEEP MENTION OF ISOLATED POPS OVER THE
ROLLING PLAINS AND THE EASTERN/CENTRAL SOUTH PLAINS THROUGH THE
NIGHT. WITH THE UPPER LOW MOVING WEST AND THE RIDGE PUSHING BACK
OVER THE AREA...POP CHANCES DECREASE TOMORROW EVEN MORE WITH
TEMPERATURES A FEW DEGREES WARMER THAN TODAY.
JORDAN
&&
.LONG TERM...
UA RIDGE WILL COMMENCE TO BUILD ACROSS THE CENTRAL PLAINS WEDNESDAY
NIGHT/THURSDAY MORNING...WHERE THE MONSOONAL MOISTURE PLUME WILL BE
CAPABLE OF BENDING EASTWARD TOWARDS THE SOUTHWESTERN TEXAS PANHANDLE
AND FAR WESTERN SOUTH PLAINS. LATEST MODEL RUNS HAVE BACKED OFF ON
SHOWING PRECIP DEVELOPING ACROSS THE AFOREMENTIONED AREAS...AS IT
GETS SHUNTED WESTWARD QUICKER THAN PREVIOUS RUNS. MID-LEVEL
INSTABILITY DROP TO 50-100 J/KG AND PWATS ALSO DECLINE TO AOA 1.00
INCH. WILL GO AHEAD AND MAINTAIN POPS TO JUST WEST OF THE TEXAS
STATE LINE. THEREAFTER...THE UA RIDGE ACROSS THE CENTRAL PLAINS WILL
BE THE DOMINATE SYNOPTIC FEATURE FOR THE SOUTHERN PLAINS...AS SLOWLY
INCREASING HEIGHT FIELDS WILL PROMOTE TEMPS TO WARM ABOVE SEASONAL
NORMS BY THE WEEKEND /MID 90S ON THE CAPROCK TO TRIPLE DIGITS OFF
THE CAPROCK/....AND LARGE SCALE SUBSIDENCE WILL MITIGATE STORM
POTENTIAL. THEREAFTER...BOTH THE GFS AND ECMWF HINT AT THE CENTER OF
THE UA RIDGE TRANSLATING EAST TOWARDS THE CENTRAL MISSISSIPPI VALLEY
EARLY NEXT WEEK. AN EASTERLY WAVE IS EXHIBITED BRUSHING ACROSS THE
SOUTHERN LOCALES ON TUESDAY. THE SAID MODELS ARE VOID OF
PRECIP...GIVEN THIS WEAKNESS IS DISPLAYED TO BE RELATIVELY WEAK.
WILL NEED TO KEEP AN EYE ON HOW THE SYNOPTIC PATTERN EVOLVES AND
WHETHER OR NOT THIS EASTERLY WAVE WILL INDEED PROVE TO BE
INCONSEQUENTIAL FOR THE SOUTHERN PLAINS...OR TURN OUT TO BE A
SYNOPTIC SPARK FOR CI.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 62 93 64 92 65 / 20 10 10 10 10
TULIA 64 94 66 93 67 / 20 10 10 10 10
PLAINVIEW 67 94 67 92 68 / 10 10 10 0 0
LEVELLAND 65 94 67 93 67 / 20 10 10 0 0
LUBBOCK 69 95 68 94 69 / 10 10 10 0 0
DENVER CITY 64 93 67 92 66 / 20 10 10 10 10
BROWNFIELD 65 93 67 92 67 / 20 10 10 0 0
CHILDRESS 70 99 72 99 73 / 10 10 10 0 0
SPUR 66 96 69 95 70 / 10 10 10 0 0
ASPERMONT 71 99 72 98 72 / 10 10 10 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
14/29
AREA FORECAST DISCUSSION
NWS SPOKANE WA
231 PM PDT Tue Jul 17 2012
.SYNOPSIS...
An unusually strong and moist upper level low will continue to
dominate our weather through Thursday. The presence of this low
will equate to localized showers and thunderstorms each day with
heavy rain at times. Another strong upper level low is expected
to move into the region via the Gulf of Alaska Thursday night and
Friday and will bring a better chance of thunderstorms. The
possibility showers and thunderstorms will remain over the
northern mountains through the weekend...otherwise the forecast
will be dry.
&&
.DISCUSSION...
Tonight...A large closed low will remain along the Northern
California coast with southerly flow ahead of this low over the
Inland Northwest. The wave that brought thunderstorms to the
region Monday night and Tuesday will continue to pull away from
the area into Southern British Columbia through the evening.
Another wave over Oregon will weaken as it moves north into
Washington this evening. Net result for tonight should be much
less lightning activity compared to last night. However there is
plenty of instability this afternoon with surface based CAPES as
of 1 pm per LAPS data of 1500-2000 J/KG. A lack of forcing and a
weak cap has limited thunderstorm activity south of Highway 2
today but some cells are developing across Northeast Oregon, the
Blues, and Camas Prairie this afternoon that will be tracking
north tonight. These may weaken when coming off the higher terrain
but potential also exists for an outflow boundary to tap into the
strong instability for thunderstorms propogating north from the
Blues into the Palouse, Lewiston area, Upper Columbia Basin,
Spokane, and Coeur D`Alene areas. HRRR which has been handling the
convection reasonably well today suggests a better potential for
storms to come off the mountains and impact Pullman and Lewiston
so will indicate better thunder chances here and only slight
chance mention from Moses Lake to Spokane. This activity will
weaken after sunset although a lingering area of mid level
instability could trigger a stray thunderstorm overnight from the
Blues to the Central Panhandle Mountains. A secondary weak wave
with less instability will track across Southern BC overnight
which could bring a few showers to areas near the Canadian border.
Also with very moist low levels and a trend towards clearing skies
overnight will likely see some patchy fog in the northern valleys
as well as the Idaho Panhandle valleys. JW
Wednesday through Friday Evening...The models are actually in
pretty good agreement after showing numerous solution changes
over the past 2-3 days. The closed low that has been cut-off from
any steering flow will remain nearly stationary through Thursday.
Meanwhile the first upper level trough that was thought to nudge
the closed low out of the region will track meekly through
northern BC. A secondary low currently near the Aleutian chain
will track into the Gulf of Alaska. This low is progged by the
models to gain strength and result in the closed low getting
ejected northeast through the Pacific Northwest late Thursday
night and Friday. There are still some minor timing issues, but
this is the second run in a row for the majority of the models to
show this solution.
Wednesday through Thursday...As mentioned above the closed low
will continue to remain nearly stationary along the southwest
Oregon coast. Pacific moisture will continue to wrap around the
low and move into the Inland Northwest. The atmosphere will
remain unstable, however the difference from the past few days is
there will not be any robust short wave disturbances moving
through the region. Therefore convection for the area will rely on
surface based heating and orographics for shower and thunderstorm
initiation. So while showers and Thunderstorms are expected, they
should not be as widespread and should not be as active. Meanwhile
the models are indicating the passage of the closed low will hold
off 24 hours until Friday. Therefore temperatures for Thursday
have been increased with highs remaining warmer then normals.
Thursday night through Friday evening. The stronger secondary
upper level low is now progged by the models to begin pushing the
closed low inland Thursday night and Friday. There will be
abundant moisture to work with as PW`s will be well above an inch
which is 150-180 percent of normal. The trough becomes negatively
tilted through the night. This pattern is good for very active
thunderstorms and there is no reason not to think this will happen Thursday
night ad Friday. Instability parameters and 0-6km wind shear will
definitely be in place and the kicker will be provided by a mid-
level cold front that tracks from near the Washington/Oregon
Cascades at 06z Friday and is mainly east of the the forecast area
by Friday afternoon. Nocturnal thunderstorms tend to be high
based with gusty outflow winds and the chance of medium to large
hail. This should be case again Thursday and Friday, however
because of the amounts of moisture expected locally heavy rain will
result in localized urban and small stream flooding. Debris flows
will also be possible. /Tobin
Friday night through Tuesday: An upper level low pressure system
that kicks out the cut off low over the region for Friday will
make its way across British Columbia through this period. There
is some question how far south this low will actually get amongst
the latest 00Z model runs. The GFS keeps the low north of the
region; the Canadian is much further south with the center of the
low tracking right across eastern WA; and the ECMWF is right in
the middle, but is the strongest of the three. How far south this
low actually tracks will determine how much precipitation we get,
if any.
The Canadian model does not track this low very well and
actually retrogrades it a bit Monday into Tuesday. This idea does
not make any sense, especially since this low pressure system is
not expected to be cut off from the Polar Jet stream unlike the
past systems we have been experiencing. Thus, the Canadian run was
thrown out of my decision making process. The GEFS ensemble mean
is a nice compromise between the 00Z GFS and ECMWF operational
runs. This would swing the low pressure system through the region
Sunday afternoon through Monday afternoon. Kept a mention of a
slight chance of showers across the northern mountains. We could
see some thunderstorms, but it looks like the best instability
will remain to our north where British Columbia will have the best
shot at thunderstorms. This low will draw up some monsoonal
moisture from the south as well, but this moisture looks as if it will
remain to our south. However, we may see some showers and
thunderstorms that could track southwest to northeast from the
Northeast Blue Mountains into the Central Panhandle. Confidence is
too low to mention showers or thunderstorms across these areas at
this time. If this low decides to track even further south, then
temperatures will need to be lowered even more, but for now went
with temperatures near normal through Monday.
The general long wave trend after Monday continues to indicate that
there will be very little movement of the strong ridge of higher
pressure over the central United States and over the eastern
Pacific. This will allow the possibility for more weather systems
to dive southward over the eastern Pacific high down into the Pac
NW. At this time, I don`t see any other strong low pressure
systems that will track into the region after Monday. This should
result in more of a zonal flow pattern over the Northwest. It
looks like we will be lacking moisture, which should result in a
fairly dry forecast after Monday. We should see temperatures warming a
bit with highs slight above average for Tuesday. /SVH
&&
.AVIATION...
18Z TAFS: A band of showers and thunderstorms north of the
Columbia Basin will impact KOMK and KCQV through the afternoon as
a slow moving wave continues to track north. Elsewhere
thunderstorms will likely develop 20-22z over the Blue Mountains
and track north towards KPUW/KLWS and used VCTS to account for
possible thunderstorms at these terminals. These storms may
survive the trip north to KGEG-KSFF-KCOE but confidence is lower
of storms impacting these sites with the main threat being from
00z-04z. This activity should wind down after 04z as the lower
atmosphere stabilizes with the loss of day time heating. JW
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 64 87 62 89 62 82 / 20 20 20 30 30 50
Coeur d`Alene 61 86 59 89 60 80 / 20 20 20 30 30 60
Pullman 58 86 56 86 58 81 / 40 20 20 30 30 20
Lewiston 67 94 65 95 68 91 / 40 30 30 30 30 20
Colville 60 90 59 90 58 85 / 30 20 30 30 30 60
Sandpoint 58 85 56 89 55 79 / 20 20 20 30 30 60
Kellogg 60 85 57 90 57 82 / 20 20 20 30 30 60
Moses Lake 64 93 62 93 63 89 / 20 20 10 20 30 50
Wenatchee 68 92 65 94 65 88 / 20 20 10 20 40 40
Omak 64 94 62 95 62 88 / 30 20 10 20 40 60
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1129 AM PDT Tue Jul 17 2012
.SYNOPSIS...
An unusually strong and moist upper level low will continue to
dominate our weather through midweek. The presence of this low
will equate to more showers and thunderstorms each day with
localized flooding possible. Yet another strong upper level low is
expected to move into the region via the Gulf of Alaska late week
or weekend. This will bring a renewed threat of thunderstorms.
&&
.DISCUSSION...
Radar imagery as of 11 am indicated a west-east band of showers
and thunderstorms stretching from Omak through Chewelah and
Sandpoint. With this band slowly moving through pops remain high
through the afternoon north of Highway 2. Cloud cover and
precipitation will also keep temperatures cooler than previously
thought so high temperatures were lowered for this afternoon. South
of Highway 2 increased sun breaks will aid in destabilizing the
atmosphere this afternoon. However with no strong wave to initate
convection thunderstorms may have a hard time making it off the
mountains. The latest HRRR suggests thunderstorms developing over
the Blues, Camas Prairie, and Central Panhandle Mountains early
this afternoon but dissipating after coming off the mountains.
With LAPS data indicating surface based CAPES of around 1000 J/KG
and with potential outflow winds from thunderstorms acting as a
forcing mechanism for convection to develop in the lower elevations,
will not completely remove pops for the rest of today in places
like Ritzville, Pullman, and Spokane. Pullman and Lewiston areas
may have a better chance this afternoon given closer proximity to
where convection is expected to initiate. With convection over the
Blues unlikely to make it as far north as Spokane/Coeur D`Alene
areas this afternoon pops were trimmed down quite a bit. These
areas may have a better chance in the evening depending on how
much thunderstorm activity can make it off the mountains. JW
&&
.AVIATION...
18Z TAFS: A band of showers and thunderstorms north of the
Columbia Basin will impact KOMK and KCQV through the afternoon as
a slow moving wave continues to track north. Elsewhere
thunderstorms will likely develop 20-22z over the Blue Mountains
and track north towards KPUW/KLWS and used VCTS to account for
possible thunderstorms at these terminals. These storms may
survive the trip north to KGEG-KSFF-KCOE but confidence is lower
of storms impacting these sites with the main threat being from
00z-04z. This activity should wind down after 04z as the lower
atmosphere stabilizes with the loss of day time heating. JW
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 84 65 83 60 80 59 / 20 30 20 20 30 30
Coeur d`Alene 84 62 82 58 79 57 / 20 40 20 20 40 30
Pullman 85 60 81 55 79 56 / 30 30 20 20 40 30
Lewiston 94 68 90 64 89 66 / 30 30 30 30 40 30
Colville 82 61 86 59 80 55 / 70 50 20 30 40 30
Sandpoint 79 59 81 56 76 52 / 70 50 20 20 40 30
Kellogg 81 59 81 56 78 55 / 30 40 20 20 40 30
Moses Lake 92 65 88 61 85 60 / 10 30 20 10 20 30
Wenatchee 90 69 88 63 84 62 / 20 30 20 10 20 40
Omak 80 66 90 60 82 58 / 90 30 20 10 20 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
332 PM CDT TUE JUL 17 2012
.SHORT TERM...TONIGHT AND WEDNESDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW THE SURFACE
COLD FRONT STRETCHING FROM ABOUT WISCONSIN RAPIDS TO APPLETON TO
KEWAUNEE EARLY THIS AFTERNOON. ELEVATED CONVECTION MOVED INTO N-C
WISCONSIN THIS MORNING IN A REGION OF UPPER DIVERGENCE...MID-LEVEL
FGEN...AND POSSIBLY AHEAD OF A WEAK MCV. ADDITIONAL CONVECTION HAS
JUST RECENTLY DEVELOPMENT IN THE WARM SECTOR OVER CENTRAL AND
EAST-CENTRAL WISCONSIN AND WILL NEED TO WATCH THIS AREA FOR SEVERE
DEVELOPMENT. WITH ML CAPES APPROACHING 2000 J/KG...INHIBITION HAS
BEEN ERODING THIS AFTERNOON AND THINK AN ISOLATED SEVERE STORM
REMAINS POSSIBLE GENERALLY SOUTH OF A MARSHFIELD TO GREEN BAY LINE.
THE MAIN THREATS WILL BE LARGE HAIL AND DAMAGING WINDS. PRECIP
TRENDS THROUGH TONIGHT ARE THE MAIN FORECAST CONCERNS.
TONIGHT...AS THE UPPER FLOW VEERS TO THE NORTHWEST...THE SURFACE
COLD FRONT WILL GET DRIVEN SOUTH FROM CENTRAL WISCONSIN TO NORTHERN
ILLINOIS. THE 850MB FRONT WILL NOT BE SO QUICK AND WILL LINGER
ALONG THE ROUTE 29 CORRIDOR THROUGH THE EVENING BEFORE SHIFTING TO
THE SOUTH. THOUGH UPPER DIVERGENCE PULLS OUT BY THIS
EVENING...850-700MB FGEN WILL LINGER ALONG THE FRONTAL SLOPE AND
THEN PUSH SOUTH LATE TONIGHT. ANY SURFACE BASED STORMS WILL BE
MOVING SOUTH OF THE FORECAST AREA EARLY THIS EVENING...BUT THE
CONVERGENT FLOW AND MID-LEVEL FGEN WILL KEEP SCATTERED POTENTIAL OF
SHOWERS AND STORMS GOING THROUGH THE NIGHT OVER CENTRAL AND
EAST-CENTRAL WISCONSIN. DO THINK STORM COVERAGE AND INTENSITY WILL
DIMINISH WITH LOSS OF HEATING...SO THE POSSIBILITY OF SEVERE
CONVECTION MAY ONLY OCCUR UNTIL EARLY THIS EVENING. COOLER AND
DRIER AIR WILL BE ARRIVING BEHIND THE FRONT AND TEMPS WILL BE
FALLING INTO THE LOWER 50S NORTH TO MID 60S SOUTH.
WEDNESDAY...A SLIGHT CHANCE OF SHOWERS WILL LINGER ACROSS CENTRAL
WISCONSIN AND THE SOUTHERN FOX VALLEY IN THE MORNING...BUT ELEVATED
CONVERGENCE HAS WEAKENED ENOUGH BY THIS TIME THAT DO NOT THINK THERE
WILL BE MANY ECHOES AROUND. AS A RESULT...WENT DRY FOR THE
AFTERNOON. NORTHERN AND NORTHEAST WISCONSIN WILL ENJOY A COOLER AND
LESS HUMID DAY UNDER PARTLY TO MOSTLY SUNNY CONDITIONS...WITH HIGHS
RANGING FROM THE UPPER 70S TO MID 80S. A FEW UPPER 80S WILL STILL
BE POSSIBLE OVER CENTRAL WISCONSIN.
.LONG TERM...WED NGT THRU NXT TUE. THE LARGE SCALE PATTERN IS
EXPECTED TO CONSIST OF A STRONG/PERSISTENT UPR RDG ALOFT OVER THE
CNTRL ROCKIES/CNTRL PLAINS AND AN UPR TROF OVER THE ERN CONUS.
BIGGEST FCST ISSUE REMAINS THE HANDLING OF SHORTWAVE TROFS MOVING
FROM THE NE PACIFIC...THRU SRN CANADA...THEN DROPPING SE INTO THE
ERN UPR TROF. EACH OF THESE SHORTWAVE TROFS WL BE ACCOMPANIED BY A
WEAK CDFNT WHICH ARE FCST TO DROP INTO WI AND EVENTUALLY STALL AS
THEY ENCOUNTER THE UPR RDG. ANY PCPN CHCS WL BE TIED TO THESE
CDFNTS...BUT AT LEAST WE WL HAVE A COUPLE CHCS FOR PCPN IN THE
EXTENDED PERIOD. TEMPS WL REMAIN ABOVE NORMAL UNTIL FURTHERN
NOTICE.
WHILE THE SFC BOUNDARY REMAINS QUASI-STNRY ACROSS CNTRL IA/NRN IL
WED NGT...THE 8H BOUNDARY TO SIT ACROSS SRN WI WITH A TIGHT
BAROCLINIC ZONE IN THE VCNTY OF THE 8H BOUNDARY. A SHORTWAVE TROF
IS FCST TO MOVE INTO THE WRN GREAT LKS BRINGING MODEST LEVELS OF
FRONTOGENETICAL FORCING INTO THE SRN HALF OF WI. BEST CONVERGENCE
SHOULD BE OVER SRN WI AS WELL...BUT CLOSE ENUF TO WARRANT CHC POPS
OVER CNTRL/E-CNTRL WI. NRN WI APPEARS TO BE TOO FAR AWAY FROM THE
PRIMARY FORCING/LIFT...THUS WL ONLY MENTION SLGT CHC POPS FOR THE
FAR NORTH.
PCPN CHCS ACROSS CNTRL/E-CNTRL WI SHOULD GRADUALLY DIMINISH THU
MORNING AS THE SHORTWAVE TROF BEGINS TO PULL AWAY FROM THE REGION.
A WEAK AREA OF HI PRES IS THEN SET TO BUILD SOUTH INTO THE NRN/WRN
GREAT LKS THU AFTERNOON AND BRING SOME MIXED SUNSHINE BACK TO NE
WI. MAX TEMPS ARE EXPECTED TO BE CLOSE TO SEASONAL NORMALS WITH
PLENTY OF LOCATIONS REACHING THE 80 TO 85 DEG RANGE (COOLER
LAKESIDE).
AS THE HI PRES SETTLES OVER THE REGION THU NGT...QUIET AND MORE
COMFORTABLE CONDITIONS WL EXIST AS COOLER/DRIER AIR FILTERS INTO
NE WI. UNDER MOSTLY CLEAR SKIES AND LIGHT WINDS...THU NGT APPEARS
TO BE THE COOLEST NGT OF THE EXTENDED PERIOD WITH READINGS DIPPING
INTO THE LWR 50S NORTH...AROUND 60 DEGS E-CNTRL WI. NE WI TO STILL
RESIDE IN A NW FLOW ALOFT THRU FRI WITH THE BACK EDGE OF HI PRES
REACHING INTO WI. CLOCKWISE CIRCULATION AROUND THE SFC HI WL BRING
SOME COOLING TO THE LAKESHORE ON E-SE WINDS. THE REST OF THE FCST
AREA TO SEE MORE OF A S-SE WIND AND WITH PLENTY OF SUNSHINE
ANTICIPATED...TEMPS WL BEGIN TO GET WARM ONCE AGAIN AS READINGS
REACH THE MID TO UPR 80S.
ATTENTION TURNS TO OUR NORTH AND WEST FRI NGT WHERE A CDFNT WL
ATTEMPT TO PUSH SE INTO THE WRN GREAT LKS. AS HAS BEEN THE CASE OF
LATE...ANY CDFNT HAS BEEN A SLOW MOVER AND THIS LATEST ONE IS NO
DIFFERENT. LATEST MDL TIMING HAS THIS FNT ONLY REACHING NRN
SECTIONS OF THE GREAT LKS BY SAT AFTERNOON...THUS HAVE MAINTAINED
A DRY FRI NGT AND ONLY A MINIMAL POP FOR THE NORTH ON SAT. A MORE
PREVAILING S-SW WIND WL BRING WARMER/MORE HUMID AIR MASS INTO WI
WITH MAX TEMPS ON SAT AGAIN FLIRTING WITH 90 DEGS AND DEW POINTS
IN THE MID 60S. THE SLOW NATURE OF THIS CDFNT IS EVIDENT AS THE
MDLS NOW DO NOT BRING THE BOUNDARY INTO NRN WI UNTIL SUNDAY. BROAD
LOW-LEVEL WAA COUPLED WITH INCREASING INSTABILITY (CAPES BETWEEN
1K AND 2K J/KG/LI`S AROUND -4)...PLENTY OF MOISTURE (DEW POINTS
IN THE MID TO UPR 60S) AND THE FNT ITSELF SHOULD BE ABLE TO
GENERATE AT LEAST A CHC FOR SHWRS/TSTMS ESPECIALLY OVER THE NORTH.
TEMPS FOR SUNDAY MAY BE TRICKY DEPENDING ON THE AMOUNT OF CLOUD
COVER/EXTENT OF ANY PCPN...BUT DUE TO THE EXPECTED WARM START TO
THE DAY...ANOTHER VERY WARM DAY ON TAP WITH PLENTY OF UPR 80S TO
LWR 90S OVER THE REGION.
THE CDFNT IS PROGGED TO SLOWLY SAG THRU CNTRL/E-CNTRL WI SUNDAY
NGT...BUT WITH THE LOSS OF DAYTIME HEATING...THE SHWR/TSTM
ACTIVITY MAY BECOME MORE WIDELY SCATTERED WITH TIME. ANY PCPN CHCS
FOR MON WL BE FOCUSED OVER THE SRN HALF OF WI AS THE FNT GRINDS TO
A HALT AS IT HITS THE UPR RDG. TEMPS ARE FCST TO BE A BIT COOLER
BY MON WITH LOWER DEW POINTS OVER THE NORTH AS DRIER AIR TRIES TO
PUSH INTO THE AREA. WINDS ARE FCST TO BACK SW ONCE AGAIN BY NXT
TUE AHEAD OF THE NXT CDFNT WHICH IS EXPECTED TO MOVE ACROSS THE
UPR MS VALLEY. BETTER UPR SUPPORT TO BE SITUATED WELL TO OUR NORTH
WHERE A PROMINENT SHORTWAVE TROF TO BE SITUATED. NEVERTHELESS...MAY
NEED TO CARRY SOME SORT OF POP ACROSS PORTIONS OF THE FCST AREA TO
ACCOUNT FOR INCREASING LOW-LEVEL WAA/INSTABILITY PARAMETERS.
&&
.AVIATION...MVFR CIGS WILL CONTINUE TO SPREAD SOUTHWARD OVER
NORTHERN WISCONSIN AS A COLD FRONT DROPS SOUTH OVER THE STATE. THE
LATEST TRENDS SUPPORT THESE MVFR CIGS MOVING INTO CENTRAL WISCONSIN
THOUGH THINK DOWNSLOPING WILL KEEP THESE CIGS VFR OVER THE FOX
VALLEY. COVERAGE OF SHOWERS AND STORMS ARE TRENDING HIGHER ACROSS
THE ENTIRE AREA THIS AFTERNOON INTO THIS EVENING AS THIS COLD FRONT
MOVES SOUTH. HAVE ADDED TEMPO GROUPS TO ACCOUNT FOR THIS. DRIER
AIR OVER LAKE SUPERIOR WILL MOVE SOUTH BEHIND THE FRONT TONIGHT AND
WILL HELP SKIES CLEAR OVER NORTHERN AND NORTHEAST WISCONSIN. SOME
POTENTIAL FOR SHOWERS...STORMS AND MVFR CIGS REMAINING OVER CENTRAL
AND EVEN EAST-CENTRAL WISCONSIN AS MOISTURE LINGERS BEHIND THE
FRONT. CLEARING SKIES SHOULD OCCUR EVERYWHERE LATE TONIGHT INTO
WEDNESDAY MORNING.
MPC
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR WIZ037-045-048.
&&
$$
MPC/KALLAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
248 PM CDT TUE JUL 17 2012
.SHORT TERM...THROUGH THURSDAY NIGHT
248 PM CDT TUE JUL 17 2012
MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES THROUGH THE PERIOD.
SURFACE ANALYSIS THIS AFTERNOON SHOWS A COLD FRONT ACROSS SOUTHERN
MINNESOTA INTO CENTRAL WISCONSIN. REGIONAL RADARS INDICATE STORMS
HAVE DEVELOPED NORTH OF THE FRONT ACROSS WISCONSIN.
THE CONVECTION ACROSS WISCONSIN HAS DEVELOPED IN RESPONSE TO A
WEAK SHORT WAVE TROUGH THAT DEVELOPED OUT OF THE STORMS OVER THE
DAKOTAS LAST NIGHT. THIS IS ALSO BEING AIDED BY THE RIGHT ENTRACE
REGION OF THE UPPER LEVEL JET OVER LAKE SUPERIOR. THE BEST CAPE
EXISTS ALONG AND AHEAD OF THE FRONT WITH AN AXIS OF 2500 J/KG OF
ML CAPE FROM CENTRAL INTO EAST CENTRAL WISCONSIN. AS THE WAVE
MOVES EAST THIS AFTERNOON...WOULD EXPECT THE CONVECTION TO
GRADUALLY SINK TO THE SOUTHEAST TOWARD THE HIGHER CAPE BUT MOST
SHOULD REMAIN BEHIND THE FRONT WHERE THERE IS NO CAP IN PLACE. THE
17.12Z HI-RES ARW AND 17.15Z HRRR SHOW THIS TREND OCCURRING WITH
THE BEST CHANCE OF ANYTHING CLIPPING THE AREA IN THE I94 CORRIDOR.
AFTER THIS EVENING THROUGH WEDNESDAY...ANY ACTIVITY THAT DEVELOPS
WILL BE CLOSELY TIED TO THE POSITION OF THE FRONT. THE 17.12Z
MODELS ALL HAVE DIFFERENT SOLUTIONS ON HOW FAR SOUTH THE FRONT
WILL GET BEFORE STALLING OUT. THE NAM AND GFS TAKE THE FRONT INTO
CENTRAL IOWA AND NORTHERN ILLINOIS TONIGHT WHILE THE 17.00Z ECMWF
HAS THE FRONT FROM NORTHERN IOWA ALONG THE WISCONSIN/ILLINOIS
BORDER. ALL THE MODELS SHOW JUST A SLOW SOUTHWARD DRIFT TO THE
FRONT WEDNESDAY. AT THIS POINT...NOT EXPECTING ANY SHORT WAVE
TROUGHS TO INTERACT WITH THE FRONT...BUT THAT COULD CHANGE IF
CONVECTION DEVELOPS OVER THE HIGH PLAINS TUESDAY NIGHT.
THE MODELS THEN DO SHOW A SHORT WAVE TROUGH COMING OUT OF THE FLOW
OVER THE ROCKIES AND TOPPING THE UPPER LEVEL RIDGE AND MOVING
ACROSS MINNESOTA AND WISCONSIN. AGAIN...THE POSITION OF THE FRONT
WILL HAVE A BIG IMPACT ON WHERE ANY CONVECTION MAY DEVELOP. WOULD
BE MORE ENTHUSED ABOUT THE RAIN CHANCES WITH THIS WAVE IF THERE
WAS ANY MOISTURE TRANSPORT OF SIGNIFIGANCE WITH THE WAVE. WITH THE
LACK OF RETURNING MOISTURE AND ANECEDENT DRY CONDTIONS...HAVE HELD
THE RAIN CHANCES FOR WEDNESDAY NIGHT AROUND 40 PERCENT. AS THIS
WAVE THEN EXITS OFF TO THE EAST THURSDAY...EXPECT THE RAIN TO MOVE
EAST AS WELL DURING THE DAY WITH A DRY THURSDAY NIGHT AS HIGH
PRESSURE BUILDS IN FROM THE NORTH.
.LONG TERM...FRIDAY THROUGH TUESDAY
248 PM CDT TUE JUL 17 2012
THE HIGH THEN LOOKS TO REMAIN OVER THE AREA INTO THE START OF THE
WEEKEND BEFORE THE NEXT FRONT STARTS TO SINK INTO THE AREA.
CURRENT INDICATIONS ARE THAT THIS FRONT WILL MOVE SOUTH ACROSS THE
AREA FROM SATURDAY NIGHT THROUGH MONDAY. THE UPPER LEVEL RIDGE IS
STILL EXPECTED TO BE ANCHORED OVER THE CENTRAL PART OF THE COUNTRY
WITH THE BULK OF THE SHORT WAVE ENERGY RIDING UP OVER THE RIDGE
ACROSS SOUTHERN CANADA. NOT OUT OF THE REALM OF POSSIBILITY THAT
ONE OF THESE WAVES COULD TEMPORARILY FLATTEN THE RIDGE AND GET
INTO THE AREA...BUT WOULD NOT COUNT ON THIS HAPPENING. THUS ANY
RAIN WITH THE FRONT SHOULD STAY ON THE SCATTERED SIDE.
&&
.AVIATION...THROUGH 18Z WEDNESDAY
1258 PM CDT TUE JUL 17 2012
CURRENTLY WATCHING A COLD FRONT DROPPING SOUTH THROUGH SOUTHERN
INTO CENTRAL WI. FROPA AT KRST/KLSE EXPECTED TO BE BETWEEN 21-24Z.
VERY WARM AIR MASS AHEAD OF THIS FRONT WITH A FAIRLY STRONG CAP
FOR CONVECTIVE INHIBITION DESPITE THE FRONTAL PASSAGE. THIS WILL
HAVE TO BE MONITORED VERY CLOSELY THIS AFTERNOON. ANY MORE
SURFACE HEATING OR COOLING ALOFT LATER THIS AFTERNOON COULD SPELL
SCATTERED SHRA/TS FOR THE TAF SITES. CONFIDENCE STILL NOT REAL
HIGH IN THIS SCENARIO..,WITH MOST CONVECTION IF ANY STAYING
NORTHEAST OF THE TAF SITES. WILL CONTINUE THE DRY FORECAST FOR
NOW AND CONTINUE TO MONITOR CLOSELY. AFTER FROPA THIS
EVENING/OVERNIGHT...EXPECT A FEW LOWER CLOUDS WITH BASES IN THE
2-3KFT RANGE AFTER 08Z. ALSO...ADDED SOME 6SM BR AT BOTH KRST/KLSE
TAF SITES WITH MOISTENING/COOLING BOUNDARY. WEDNESDAY WILL SEE LOW
PRESSURE PUSHING EAST OUT OF THE CENTRAL PLAINS. THIS LOW WILL
WORK ON THE FRONTAL BOUNDARY FOR SCATTERED SHRA/TS...BUT THIS
LOOKS TO BE MORE IN THE AFTERNOON IN PEAK HEATING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
248 PM CDT TUE JUL 17 2012
WI...HEAT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR WIZ041>044-053>055-
061.
MN...HEAT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR MNZ094>096.
IA...HEAT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR IAZ008>011-018-019-
029-030.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...DAS