Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 09/15/12
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1001 PM EDT FRI SEP 14 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS SOUTHERN NEW ENGLAND LATE TONIGHT
AND EARLY SATURDAY BRINGING SCATTERED SHOWERS. DRY AND COOLER WEATHER
WILL RETURN THIS WEEKEND INTO MONDAY...THEN A SLOW MOVING COLD FRONT
WILL LIKELY BRING SHOWERS WITH LOCALLY HEAVY RAINFALL TUE INTO EARLY
WEDNESDAY FOLLOWED BY DRY AND SEASONABLY COOL WEATHER TOWARD THE END
OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
10 PM UPDATE...
BAND OF SHOWERS WITH ISOLATED THUNDER ACROSS NY STATE AND NORTH
CENTRAL PA CONTINUES TO SLOWLY WEAKEN AS INSTABILITY WANES WITH
COOLING BLYR. LIGHTNING STRIKES DIMINISHING RAPIDLY AS WELL.
POTENT SHORT WAVE TAKING ON A NEGATIVE TILT ALONG WITH WEAK
INSTABILITY ALOFT SHOULD BE ABLE TO SUSTAIN A BAND OF SHOWERS
ACROSS THE REGION OVERNIGHT. 21Z SREF AND LATEST HRRR SUPPORT THIS
IDEA. BY NO MEANS A WASHOUT BUT BE PREPARED TO DODGE OF FEW
SHOWERS DURING THE PREDAWN HOURS INTO SAT MORNING. PREVIOUS
FORECAST CAPTURES THIS WELL SO NO CHANGES PLANNED.
IT WILL NOT BE AS COOL AS PREVIOUS NIGHTS WITH LOW LEVEL WARM AIR
ADVECTION AHEAD OF APPROACHING COLD FRONT ADVECTING DEW PTS INTO
THE L60S FROM COASTAL CT/RI INTO SOUTHEAST MA AT 9 PM. THIS
INCREASE IN LOW LEVEL MOISTURE WILL YIELD PATCHY FOG. ALREADY
SEEING SOME STRATUS/LOW CLOUDS FROM MVY TO CQX. THUS WILL BEGIN
THE ONSET OF FOG A BIT EARLIER WITH THIS FORECAST ISSUANCE.
OTHERWISE FORECAST MATCHING UP WELL WITH LATEST OBSERVATIONS/
SATELLITE IMAGERY AND RADAR TRENDS.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
MID-LEVEL TROUGH AND ATTENDING SURFACE COLD FRONT SHOULD BE
PROGRESSIVE WITH ANY LINGERING SHOWERS ACROSS RI AND EASTERN MA
CENTERED AROUND 12Z AND THEN MOVING OFF THE CAPE AROUND 15Z. LOW
PROBABILITY OF AN ISOLATED TSTM GIVEN INSTABILITY ALOFT COUPLED
WITH STRONG JET DYNAMICS. GREATEST RISK OF THUNDER WILL BE ALONG
THE SOUTH COAST INCLUDING CAPE AND THE ISLANDS.
STILL EXPECTING EXCELLENT DRYING AND COOLING BEHIND THIS COLD
FRONT. 850 MB TEMPERATURES SHOULD DROP FROM AROUND +10C AT 12Z
SAT TO +5C BY 00Z SUN. ALTHOUGH GOOD BOUNDARY LAYER MIXING WITH
DOWNSLOPE NW WINDS AND PARTIAL SUNSHINE /POST FRONTAL STRATO-CU/
SHOULD HELP TEMPERATURES REBOUND INTO THE LOWER 70S BY AFTERNOON.
COOLER ACROSS THE HIGHER TERRAIN IN RESPONSE TO THE COLD AIR
ADVECTION...ALTHOUGH CLOSE TO NORMAL FOR THIS TIME OF YEAR.
DRY WITH BELOW NORMAL TEMPERATURES EXPECTED SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGHLIGHTS...
* DRY WEATHER SUNDAY AND MONDAY
* LOCALLY HEAVY RAINFALL POSSIBLE TUE INTO EARLY WED
* DRY AND SEASONABLY COOL END OF NEXT WEEK
OVERVIEW...
MODEL GUIDANCE IS IN PRETTY GOOD AGREEMENT DURING THE LONG TERM
PERIOD. AMPLIFYING GT LAKES TROF AND SLOW MOVING COLD FRONT WILL
LIKELY BRING A PERIOD OF HEAVY RAINFALL SOMETIME DURING TUE INTO
EARLY WED TIMEFRAME. THERE ARE SOME TIMING DIFFERENCES AMONG THE
MODELS WITH GFS/UKMET FASTER THAN THE ECMWF/GGEM. SO WHILE THERE IS
SOME UNCERTAINTY WITH THE TIMING AND LOCATION OF THE AXIS OF
HEAVIEST RAINFALL...CONFIDENCE IS ABOVE NORMAL IN GETTING A HEAVY
RAINFALL EVENT ACROSS SNE. COOLER AND DRIER WEATHER WILL FOLLOW
TOWARD THE END OF NEXT WEEK.
SUN INTO MON...
HIGH PRES IN CONTROL WILL BRING DRY WEATHER WITH MAINLY CLEAR
SKIES. SUNDAY WILL BE THE COOLER OF THE 2 DAYS AS COOLEST 850 MB
TEMPS WILL BE OVER THE REGION...THEN MODERATING TEMPS MONDAY.
MON NIGHT INTO WED...
WE LEANED TOWARD SLOWER ECMWF SOLUTION FOR THIS PORTION OF THE
FORECAST AS AMPLIFIED TROF TO THE WEST WILL LIKELY SUPPORT A SLOWER
TIMING OF THE COLD FRONT. SO WHILE SHOWERS MAY MOVE INTO W ZONES BY
LATE MON NIGHT...IT APPEARS THE HEAVIEST RAINFALL WILL BE DURING TUE
INTO TUE NIGHT W ZONES AND MAINLY TUE NIGHT INTO EARLY WED ACROSS E
NEW ENG...WITH GRADUAL IMPROVING CONDITIONS FROM WEST TO EAST DURING
WED.
CONFIDENCE IS ABOVE NORMAL IN A HEAVY RAINFALL EVENT AS 50-60 KT LOW
LEVEL JET WILL RESULT IN STRONG LOW LEVEL CONVERGENCE AND ADVECT
ANOMALOUSLY HIGH PWATS NEAR 2" INTO SNE. GFS ENSEMBLE MEAN SHOWING
+3SD LLJ AND +2SD PWAT PLUME WHICH IS A PRETTY STRONG SIGNAL AT THIS
TIME RANGE FOR A HEAVY RAINFALL EVENT. LATEST GUIDANCE IS TARGETING
W ZONES FOR HEAVIEST RAIN BUT THIS IS NOT CERTAIN YET AS SUBSEQUENT
MODEL RUNS COULD STILL SHIFT THE AXIS. THERE IS ELEVATED
INSTABILITY WITH THE LOW LEVEL JET SO A FEW TSTMS ARE POSSIBLE AS
WELL.
THU INTO FRI...
DRY AND COOLER WEATHER FOLLOWS WITH HIGH PRES BUILDING OVER THE
REGION.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
SHORT TERM...
HIGH CONFIDENCE MOST LOCATIONS REMAIN VFR THROUGH TONIGHT. SPOTTY
MVFR/IFR COMING ONSHORE AT 9 PM FROM MVY TO CQX. IMPROVING
CONDITIONS FROM WEST TO EAST SUNRISE SAT.
A COLD FRONT ENTERS THE REGION TONIGHT WITH SCATTERED SHOWERS
MOVING ACROSS CT AND WESTERN MA INTO SOUTHWEST NH...THEN ACROSS RI
AND EASTERN MA 12Z-15Z SAT. A BRIEF PERIOD OF MARGINAL MVFR/VFR
MAY ACCOMPANY THESE SHOWERS. LOW PROBABILITY OF AN ISOLATED TSTM
LATE TONIGHT INTO SAT MORNING...WITH HIGHEST PROBABILITY ALONG THE
SOUTH COAST OF RI AND MA. VFR RETURNS BY SAT AFTERNOON WITH DRY
RUNWAYS AND A MODEST NW WIND.
KBOS TAF...HIGH CONFIDENCE FOR VFR THROUGH THIS EVENING. THEN
SCATTERED SHOWERS 12Z-15Z SAT WITH BRIEF MVFR POSSIBLE. VFR RETURNS
AFT 15Z WITH CIGS BKN050 ALONG WITH DRY WEATHER AND A MODEST NW WIND.
KBDL TAF...HIGH CONFIDENCE FOR VFR THIS EVENING. SCATTERED SHOWERS
WITH BRIEF MVFR POSSIBLE 08Z-12Z. IMPROVING TO VFR AFTER 12Z SAT
WITH CIGS BKN050 ALONG WITH DRY RUNWAYS AND A MODEST NW WIND.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
SUNDAY THROUGH MONDAY...HIGH CONFIDENCE. VFR...EXCEPT PATCHY LATE
NIGHT AND EARLY MORNING FOG IN THE INTERIOR VALLEYS.
TUESDAY INTO WEDNESDAY...MODERATE CONFIDENCE. MVFR/IFR CONDITIONS
IN SHOWERS...LOCALLY HEAVY. GRADUAL IMPROVEMENT FROM WEST TO EAST
DURING WED.
&&
.MARINE...
TODAY THROUGH SATURDAY NIGHT...HIGH CONFIDENCE.
RELATIVELY TRANQUIL WINDS AND SEAS TONIGHT INTO SATURDAY. A COLD
FRONT WILL CROSS THE WATERS SATURDAY...WITH WINDS BECOMING
NORTHWEST BY AFTERNOON. COULD SEE SOME GUSTS UP TO 20 KT SATURDAY
AFTERNOON AND NIGHT. THE INCREASED WINDS...AS WELL AS SOME SWELL
ARRIVING FROM DISTANT TROPICAL STORM NADINE...COULD LEAD TO
MARGINAL 5 FOOT SEAS ACROSS THE OUTER COASTAL WATERS.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
MAY SEE SOME MARGINAL 5 FT SEAS OVER THE OUTER COASTAL WATERS SUNDAY
INTO SUN NIGHT...OTHERWISE WINDS WILL BE BELOW SCA THRESHOLDS
THROUGH MONDAY.
HIGH CONFIDENCE IN A PERIOD OF SCA SOUTHERLY WINDS AND SEAS TUE INTO
TUE NIGHT ALTHOUGH TIMING OF STRONGEST WINDS NOT CERTAIN. THERE IS
EVEN A CHANCE OF GALE FORCE GUSTS SOMETIME LATE TUE OR TUE NIGHT
AS THE CORE OF THE LOW LEVEL JET MOVES THROUGH BUT CONFIDENCE IS
LOWER.
WINDS WILL BE SHIFTING TO THE WEST ON WEDNESDAY WITH DECREASINGG
SPEEDS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BELK/KJC
NEAR TERM...BELK/KJC/NOCERA - UPDATED 10 PM
SHORT TERM...BELK
LONG TERM...KJC
AVIATION...BELK/KJC - UPDATED 10 PM
MARINE...BELK/KJC
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
857 PM EDT FRI SEP 14 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL CROSS OUR AREA TONIGHT, FOLLOWED BY HIGH
PRESSURE FOR MOST OF SATURDAY AND SUNDAY. THE HIGH MOVES OFF TO
OUR EAST ON MONDAY AS AN AREA OF LOW PRESSURE, ALONG WITH A STRONG
COLD FRONT, APPROACHES FROM THE WEST. MEANWHILE, ANOTHER AREA OF
LOW PRESSURE WILL MOVE TOWARD OUR AREA FROM THE SOUTHEAST BEFORE
MERGING WITH THE AFOREMENTIONED FRONTAL SYSTEM. THE COLD FRONT
CROSSES THE REGION LATE TUESDAY NIGHT THROUGH EARLY WEDNESDAY.
HIGH PRESSURE WILL THEN BUILD IN FOR THURSDAY THROUGH FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THE SURFACE COLD FRONT STRETCHED ACROSS CENTRAL NEW YORK STATE AND
WEST CENTRAL PENNSYLVANIA AT 0000 UTC. AHEAD OF THE FRONT...THE
AIRMASS IS FAIRLY DRY AND STABLE...AS EVIDENCED BY THE 0000 UTC
SOUNDINGS. THE AIRMASS JUST AHEAD OF THE FRONT IS MARGINALLY
UNSTABLE (AS SHOWN BY THE LATEST MSAS LIFTED INDEX FIELDS)...BUT THE
COLUMN IS FAIRLY DRY ACROSS MUCH OF WESTERN AND CENTRAL
PENNSYLVANIA. THE LINE OF SHOWERS ASSOCIATED WITH THE FRONT ARE
HAVING A HARD TIME STAYING TOGETHER ACROSS THE ABOVEMENTIONED AREA.
FURTHER NORTH...THE MARGINAL INSTABILITY IS COUPLING WITH THE
SYNOPTIC SCALE LIFT AHEAD OF THE NEGATIVELY TILTED MID LEVEL TROUGH
SWEEPING ACROSS THE GREAT LAKES. THE COMBINATION HAS BEEN ENOUGH FOR
CHARGE SEPARATION TO OCCUR OVER NORTH CENTRAL PENNSYLVANIA AND
CENTRAL NEW YORK STATE. IT WOULD APPEAR AS THOUGH ANY THUNDER SHOULD
STAY WELL NORTH OF THE AREA...STAYING CLOSER TO THE INCREASING MID
LEVEL SHEAR OVER NEW ENGLAND.
AS MENTIONED EARLIER...THE AIRMASS IN PLACE IS DRY...AND THIS SHOULD
HELP MITIGATE THE SHOWER THREAT LATE THIS EVENING AND DURING THE
EARLY OVERNIGHT HOURS. THE LATEST HRRR SHOWS MUCH OF THE SHOWER
ACTIVITY DRYING UP BEFORE IT REACHES THE AREA. THE BEST CHANCE OF
SHOWERS WILL BE ACROSS THE SOUTHERN POCONOS AND NORTHWEST NEW
JERSEY...WHERE THE BEST OF THE RESIDUAL INSTABILITY SHOULD CROSS.
THE MENTION OF SHOWERS WAS MAINTAINED FOR PORTIONS OF THE LEHIGH
VALLEY...AS EXTRAPOLATION WOULD BRING SCATTERED SHOWERS TO THIS AREA
BY ABOUT 0400 UTC OR SO.
ELSEWHERE...THE FORECAST REMAINS DRY. THERE IS A NARROW BAND OF
CLOUDS WITHIN THE FRONTAL ZONE...AND THE CLOUDS SHOULD AFFECT MUCH
OF THE NORTHERN TWO THIRDS OF THE AREA. TIMING OF THE FRONT PUTS IT
IN THE LEHIGH VALLEY CLOSE TO 0600 UTC...THE PHILADELPHIA AREA BOUT
0800 UTC...AND OFF THE COAST BEFORE 1100 UTC. THE LOW LEVEL COOL
PUSH APPEARS TO BE FAIRLY STRONG...WITH GUSTS OVER 20 KNOTS ACROSS
PORTIONS OF WEST CENTRAL PENNSYLVANIA. AT THIS POINT...WILL NOT
INCREASE THE GUSTS IN THE FORECAST NOW UNTIL IT BECOMES MORE
APPARENT THAT THE GUSTINESS WILL MAKE IT INTO THE FORECAST AREA.
NO SIGNIFICANT CHANGES WERE MADE TO THE LOW TEMPERATURE AND WIND
FORECASTS FOR TONIGHT. THE HOURLY TEMPERATURES AND DEW POINTS WERE
ADJUSTED TO FIT EXPECTED TRENDS.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
AS THE MID LEVEL TROUGH AND THE SURFACE FRONT CONTINUE TO MOVE
FARTHER TO OUR EAST ON SATURDAY, HIGH PRESSURE WILL BEGIN BUILDING
INTO OUR REGION FROM THE WEST. AS A RESULT, WE EXPECT A MOSTLY SUNNY
SKY FOR SATURDAY AFTER PERHAPS SOME LINGERING MORNING CLOUDS OVER
OUR SOUTHEASTERN COUNTIES.
A NORTHWEST TO NORTH WIND SHOULD BRING DEW POINT READINGS DOWN INTO
THE 40S FOR SATURDAY AFTERNOON WITH AIR TEMPERATURES RISING INTO THE
70S. TEMPERATURES MAY NOT GET OUT OF THE 60S IN THE ELEVATED TERRAIN.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
A LARGE AREA OF HIGH PRESSURE BUILDS ACROSS THE REGION THIS WEEKEND,
MOVING DIRECTLY OVERHEAD ON SUNDAY AND THEN PUSHING EASTWARD THROUGH
MONDAY. THIS HIGH WILL DOMINATE OUR WEATHER THROUGH EARLY NEXT WEEK,
KEEPING US FAIRLY DRY.
THE HIGH SHIFTS EASTWARD ON MONDAY AS A STRONG SYSTEM STARTS TO
DEVELOP TO OUR WEST. WITH HIGH PUSHING EASTWARD, WE START TO GET A
RETURN FLOW AROUND IT INTO OUR AREA. THIS WILL BRING IN SOME WARMER
AND MOISTER AIR VIA WAA. THE MODELS CONTINUE TO DIFFER AS TO JUST
HOW MUCH OF AN IMPACT WE WILL FEEL ON MONDAY IN THE DEEPENING WAA. A
WARM FRONT BEGINS TO DEVELOP ACROSS THE SOUTHEASTERN STATES AND
BEGINS TO PUSH NORTHWARD. WITH THE WARM FRONT PUSHING NORTH, WE WILL
CONTINUE TO MOISTEN UP OUR ATMOSPHERE, WHICH HAS BEEN RELATIVELY DRY
THE PAST WEEK. DUE TO THAT DRY AIR IN PLACE, IT MIGHT TAKE A WHILE
FOR US TO BE MOIST ENOUGH TO SEE RAIN MOVE INTO THE AREA. AS A
RESULT, WE KEEP MONDAY FAIRLY DRY DURING THE DAY AND THEN START AN
INCREASE OF POPS THROUGH THE AFTERNOON AND MORE SO OVERNIGHT INTO
TUESDAY.
AN AREA OF LOW PRESSURE DEVELOPS ACROSS THE SOUTHEASTERN UNITED
STATES AND TRACKS TOWARD OUR REGION ON TUESDAY. THIS LOW LOOKS LIKE
IT BECOMES ENVELOPED INTO THE APPROACHING FRONTAL SYSTEM AS IT MOVES
NORTHEAST.
A COLD FRONT WILL APPROACH FROM THE WEST AND MOVE THROUGH LATE
TUESDAY NIGHT INTO WEDNESDAY. WITH THE INCREASING MOISTURE IN THE
WAA AHEAD OF THE SURFACE COLD FRONT TO OUR WEST, WE SEE PWATS
INCREASE UP TO AROUND 2 INCHES. THIS KEEPS THE INCREASED CHANCES FOR
HEAVY RAIN ACROSS THE REGION. FOR NOW, CONVECTION LOOKS LIKE IT
MIGHT BE LIMITED TO RIGHT ALONG THE FRONT WHERE THE BEST LIFT WILL
BE AND CONVECTION HAS BEEN MENTIONED BUT REMAINS SCATTERED OR
ISOLATED.
THE FRONT QUICKLY PUSHES THROUGH THE REGION AND WE SHOULD START TO
CLEAR OUT AND DRY OUT THROUGH THE DAY ON WEDNESDAY FROM WEST TO
EAST. ANOTHER AREA OF HIGH PRESSURE BUILDS IN BEHIND THE FRONT AND
THEN LASTS THROUGH MUCH OF THE REST OF THE WEEK.
TEMPERATURES WILL BE SLIGHTLY BELOW OR NEAR NORMAL THROUGH THE
EXTENDED PERIOD.
&&
.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
VFR CONDITIONS CONTINUE THIS EVENING WITH MAINLY MID AND HIGH
CLOUDINESS. A COLD FRONT STRETCHED ACROSS WESTERN NEW YORK STATE AND
WESTERN PENNSYLVANIA SHOULD CROSS THE LEHIGH VALLEY ABOUT 0600
UTC...PASS KPHL ABOUT 0800 UTC...AND EXIT THE COAST CLOSE TO 1100
UTC. AHEAD OF THE FRONT...A LIGHT SOUTH TO SOUTHWEST FLOW WILL
PERSIST...AND THIS SHOULD PREVENT PATCHY MVFR FOG FROM FORMING IN
PLACES LIKE KRDG AND KMIV.
THE BULK OF THE SHOWER ACTIVITY SHOULD PASS NORTH OF THE AREA...WITH
KABE HAVING THE BEST CHANCE OF SEEING ANY VFR RAIN SHOWERS. VFR
CEILINGS BETWEEN 4000 AND 6000 FEET SHOULD ACCOMPANY THE FRONT...AND
LINGER FOR A COUPLE OF HOURS AFTER THE FRONTAL PASSAGE. BEHIND THE
FRONT...WINDS SHOULD BECOME NORTH...BUT SPEEDS SHOULD REMAIN BELOW
10 KNOTS THROUGH SUNRISE.
VFR CONDITIONS ARE EXPECTED SATURDAY. AFTER THE STRATOCUMULUS DECK
EXITS IN THE MORNING...ONLY SCATTERED CLOUDS ARE EXPECTED FOR THE
BALANCE OF THE DAY. THE NORTHERLY WIND GRADIENT TIGHTENS DURING THE
MORNING...AND A FEW LOCATIONS (LIKE KPHL AND KACY) SHOULD SEE GUSTS
NEAR 20 KNOTS BETWEEN ABOUT 1400 UTC AND 1900 UTC. THE GUSTINESS
SHOULD BACK OFF BEFORE 0000 UTC SUNDAY.
OUTLOOK...
SATURDAY NIGHT AND SUNDAY...VFR CONDITIONS EXPECTED. NORTHWEST WINDS
WILL BECOME MORE SOUTHWESTERLY THROUGH SUNDAY WHILE REMAINING AROUND
10 KNOTS OR LESS.
MONDAY AND TUESDAY...VFR TO START ON MONDAY THEN DETERIORATING
CONDITIONS AS A COLD FRONT PUSHES TOWARD THE AREA, MOVING THROUGH
LATE TUESDAY. SUB-VFR CONDITIONS POSSIBLE, ESPECIALLY FROM MONDAY
AFTERNOON ONWARD AS LOW LEVEL MOISTURE INCREASES AND SHOWERS BEGIN
TO DEVELOP. WINDS WILL BE OUT OF THE SOUTH THROUGH TUESDAY SHIFTING
TO THE WEST TUESDAY NIGHT. WINDS MAY ALSO BECOME GUSTY LATE TUESDAY.
WEDNESDAY...MVFR/IFR CONDITIONS WILL IMPROVE AS THE COLD FRONT
PUSHES TO OUR EAST. ANY LINGERING SHOWERS SHOULD CLEAR OUT BY EARLY
AFTERNOON AND A RETURN TO VFR BY THE LATE AFTERNOON CAN BE
EXPECTED. WEST TO NORTHWEST WINDS WILL CONTINUE ON WEDNESDAY WITH
SPEEDS AROUND 10 TO 15 KNOTS. WINDS START TO SUBSIDE INTO
WEDNESDAY EVENING.
&&
.MARINE...
IT APPEARS AS THOUGH THE LOW LEVEL PRESSURE GRADIENT HAS BEEN
AUGMENTED BY LOCAL SEA AND BAY BREEZES...AS WINDS ARE GUSTING ABOVE
15 KNOTS OVER THE DELAWARE BAY AND PORTIONS OF THE NEW JERSEY COAST.
THE UPDATED FORECAST ACCOUNTED FOR THIS. HOWEVER...THE EFFECT
APPEARS TO BE LINGERING LATER INTO THE EVENING...AND THE FORECAST
WILL BE UPDATED TO ACCOUNT FOR THE CHANGE.
THERE COULD BE SOME GUSTS NEAR 20 KNOTS AS WINDS SHIFT TO THE NORTH
LATE TONIGHT BEHIND THE FRONT (THERE HAS BEEN SOME GUSTINESS WITH
THE FRONT OVER LAND ACROSS WESTERN PENNSYLVANIA). WHILE THERE COULD
BE A LOW LEVEL PUSH...WINDS ARE EXPECTED TO REMAIN BELOW 25 KNOTS
TONIGHT.
A DRY COLD FRONT FROM THE WEST IS FORECAST TO ARRIVE LATE
TONIGHT, FOLLOWED BY ANOTHER AREA OF HIGH PRESSURE FOR SATURDAY.
WIND SPEEDS AND WAVE HEIGHTS WILL REMAIN BELOW THE SMALL CRAFT
ADVISORY CRITERIA DURING SATURDAY.
OUTLOOK...
SEAS BUILD OVER THE WEEKEND TO AROUND 5 FEET AND A SMALL CRAFT
ADVISORY MAY BE NEEDED FOR SUNDAY. SEAS SUBSIDE AS HIGH PRESSURE
BUILDS OVERHEAD EARLY IN THE WEEK. HOWEVER, SEAS WILL START TO RISE
AGAIN LATE ON MONDAY INTO TUESDAY AS A WARM FRONT MAKES IT WAY
NORTHWARD AND THROUGH OUR AREA. WITH A SOUTHERLY FLOW IN PLACE, SEAS
WILL START TO RISE TO NEAR 5 FEET BY EARLY TUESDAY AND WILL CONTINUE
TO INCREASE THROUGH THE DAY. WITH THE GRADIENT TIGHTENING UP AS A
COLD FRONT APPROACHES FROM THE WEST FOR TUESDAY, WINDS WILL BECOME
INCREASINGLY GUSTIER OVER OUR AREA WATERS. GUSTS LOOK TO REMAIN
AROUND 30 KNOTS ON TUESDAY INTO WEDNESDAY BUT GUST UP TO GALE
FORCE REMAIN A POSSIBILITY. WAVEWATCH PUSHES SEAS UP AROUND 8 OR
9 FEET ON TUESDAY AND EVEN THOUGH THE WINDS LOOK TO BE PRETTY
ROBUST, WE DECIDED TO TONE IT DOWN JUST A BIT. A SMALL CRAFT
ADVISORY LOOKS LIKE IT WILL BE NEEDED FOR TUESDAY AND CONTINUING
INTO WEDNESDAY.
&&
.RIP CURRENTS...
THE RIP CURRENT RISK FOR SATURDAY MAY END UP BEING HIGHLY DEPENDENT
ON THE PERIOD OF THE INCOMING SWELLS FROM NADINE. THE 1800 UTC
WNAWAVE MODEL OUTPUT SHOWS A 13 TO 14 SECOND PERIOD WAVE SET
ARRIVING DURING THE MORNING. A PERIOD OF 13 OR 14 SECONDS...COMBINED
WITH A NORTH WIND NEAR 15 MPH...COULD END UP PUSHING THE RISK TO
MODERATE FOR NEW JERSEY...WITH THE BEST EXPOSURE.
FOR NOW...THE RIP CURRENT RISK FOR SATURDAY IS SET AT MODERATE.
HOWEVER...IF PERIOD DOES INDEED INCREASE TO 13 SECONDS OR GREATER...
IT COULD PRODUCE A MODERATE RISK OF RIP CURRENT...ESPECIALLY DURING
TIDE CHANGES.
THERE IS A HIGH PROBABILITY FOR AT LEAST A MODERATE RISK OF
DANGEROUS RIP CURRENTS SUNDAY THROUGH TUESDAY.
A 4 FT 14 SECOND SE SWELL IS STILL OUTLOOKED FOR SUNDAY FROM THE
00Z/14 WW3 AND THEN THAT EASES TO A 3 FT 12 SEC ESE SWELL MONDAY.
TUESDAY IS A PROBABLE STRENGTHENING CFP AND EITHER WAY...3 FT 10
SEC LEFTOVERS FROM NADINE OR A SOUTHERLY PRE-CFP 6 FT 6 SEC
SWELL... BOTH OPTIONS SUGGEST A MDT RISK.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MEOLA
NEAR TERM...HAYES
SHORT TERM...IOVINO
LONG TERM...MEOLA
AVIATION...HAYES/MEOLA
MARINE...IOVINO/HAYES/MEOLA
RIP CURRENTS...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
823 PM EDT FRI SEP 14 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL CROSS OUR AREA TONIGHT, FOLLOWED BY HIGH
PRESSURE FOR MOST OF SATURDAY AND SUNDAY. THE HIGH MOVES OFF TO
OUR EAST ON MONDAY AS AN AREA OF LOW PRESSURE, ALONG WITH A STRONG
COLD FRONT, APPROACHES FROM THE WEST. MEANWHILE, ANOTHER AREA OF
LOW PRESSURE WILL MOVE TOWARD OUR AREA FROM THE SOUTHEAST BEFORE
MERGING WITH THE AFOREMENTIONED FRONTAL SYSTEM. THE COLD FRONT
CROSSES THE REGION LATE TUESDAY NIGHT THROUGH EARLY WEDNESDAY.
HIGH PRESSURE WILL THEN BUILD IN FOR THURSDAY THROUGH FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THE SURFACE COLD FRONT STRETCHED ACROSS CENTRAL NEW YORK STATE AND
WEST CENTRAL PENNSYLVANIA AT 0000 UTC. AHEAD OF THE FRONT...THE
AIRMASS IS FAIRLY DRY AND STABLE...AS EVIDENCED BY THE 0000 UTC
SOUNDINGS. THE AIRMASS JUST AHEAD OF THE FRONT IS MARGINALLY
UNSTABLE (AS SHOWN BY THE LATEST MSAS LIFTED INDEX FIELDS)...BUT THE
COLUMN IS FAIRLY DRY ACROSS MUCH OF WESTERN AND CENTRAL
PENNSYLVANIA. THE LINE OF SHOWERS ASSOCIATED WITH THE FRONT ARE
HAVING A HARD TIME STAYING TOGETHER ACROSS THE ABOVEMENTIONED AREA.
FURTHER NORTH...THE MARGINAL INSTABILITY IS COUPLING WITH THE
SYNOPTIC SCALE LIFT AHEAD OF THE NEGATIVELY TILTED MID LEVEL TROUGH
SWEEPING ACROSS THE GREAT LAKES. THE COMBINATION HAS BEEN ENOUGH FOR
CHARGE SEPARATION TO OCCUR OVER NORTH CENTRAL PENNSYLVANIA AND
CENTRAL NEW YORK STATE. IT WOULD APPEAR AS THOUGH ANY THUNDER SHOULD
STAY WELL NORTH OF THE AREA...STAYING CLOSER TO THE INCREASING MID
LEVEL SHEAR OVER NEW ENGLAND.
AS MENTIONED EARLIER...THE AIRMASS IN PLACE IS DRY...AND THIS SHOULD
HELP MITIGATE THE SHOWER THREAT LATE THIS EVENING AND DURING THE
EARLY OVERNIGHT HOURS. THE LATEST HRRR SHOWS MUCH OF THE SHOWER
ACTIVITY DRYING UP BEFORE IT REACHES THE AREA. THE BEST CHANCE OF
SHOWERS WILL BE ACROSS THE SOUTHERN POCONOS AND NORTHWEST NEW
JERSEY...WHERE THE BEST OF THE RESIDUAL INSTABILITY SHOULD CROSS.
THE MENTION OF SHOWERS WAS MAINTAINED FOR PORTIONS OF THE LEHIGH
VALLEY...AS EXTRAPOLATION WOULD BRING SCATTERED SHOWERS TO THIS AREA
BY ABOUT 0400 UTC OR SO.
ELSEWHERE...THE FORECAST REMAINS DRY. THERE IS A NARROW BAND OF
CLOUDS WITHIN THE FRONTAL ZONE...AND THE CLOUDS SHOULD AFFECT MUCH
OF THE NORTHERN TWO THIRDS OF THE AREA. TIMING OF THE FRONT PUTS IT
IN THE LEHIGH VALLEY CLOSE TO 0600 UTC...THE PHILADELPHIA AREA BOUT
0800 UTC...AND OFF THE COAST BEFORE 1100 UTC. THE LOW LEVEL COOL
PUSH APPEARS TO BE FAIRLY STRONG...WITH GUSTS OVER 20 KNOTS ACROSS
PORTIONS OF WEST CENTRAL PENNSYLVANIA. AT THIS POINT...WILL NOT
INCREASE THE GUSTS IN THE FORECAST NOW UNTIL IT BECOMES MORE
APPARENT THAT THE GUSTINESS WILL MAKE IT INTO THE FORECAST AREA.
NO SIGNIFICANT CHANGES WERE MADE TO THE LOW TEMPERATURE AND WIND
FORECASTS FOR TONIGHT. THE HOURLY TEMPERATURES AND DEW POINTS WERE
ADJUSTED TO FIT EXPECTED TRENDS.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
AS THE MID LEVEL TROUGH AND THE SURFACE FRONT CONTINUE TO MOVE
FARTHER TO OUR EAST ON SATURDAY, HIGH PRESSURE WILL BEGIN BUILDING
INTO OUR REGION FROM THE WEST. AS A RESULT, WE EXPECT A MOSTLY SUNNY
SKY FOR SATURDAY AFTER PERHAPS SOME LINGERING MORNING CLOUDS OVER
OUR SOUTHEASTERN COUNTIES.
A NORTHWEST TO NORTH WIND SHOULD BRING DEW POINT READINGS DOWN INTO
THE 40S FOR SATURDAY AFTERNOON WITH AIR TEMPERATURES RISING INTO THE
70S. TEMPERATURES MAY NOT GET OUT OF THE 60S IN THE ELEVATED TERRAIN.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
A LARGE AREA OF HIGH PRESSURE BUILDS ACROSS THE REGION THIS WEEKEND,
MOVING DIRECTLY OVERHEAD ON SUNDAY AND THEN PUSHING EASTWARD THROUGH
MONDAY. THIS HIGH WILL DOMINATE OUR WEATHER THROUGH EARLY NEXT WEEK,
KEEPING US FAIRLY DRY.
THE HIGH SHIFTS EASTWARD ON MONDAY AS A STRONG SYSTEM STARTS TO
DEVELOP TO OUR WEST. WITH HIGH PUSHING EASTWARD, WE START TO GET A
RETURN FLOW AROUND IT INTO OUR AREA. THIS WILL BRING IN SOME WARMER
AND MOISTER AIR VIA WAA. THE MODELS CONTINUE TO DIFFER AS TO JUST
HOW MUCH OF AN IMPACT WE WILL FEEL ON MONDAY IN THE DEEPENING WAA. A
WARM FRONT BEGINS TO DEVELOP ACROSS THE SOUTHEASTERN STATES AND
BEGINS TO PUSH NORTHWARD. WITH THE WARM FRONT PUSHING NORTH, WE WILL
CONTINUE TO MOISTEN UP OUR ATMOSPHERE, WHICH HAS BEEN RELATIVELY DRY
THE PAST WEEK. DUE TO THAT DRY AIR IN PLACE, IT MIGHT TAKE A WHILE
FOR US TO BE MOIST ENOUGH TO SEE RAIN MOVE INTO THE AREA. AS A
RESULT, WE KEEP MONDAY FAIRLY DRY DURING THE DAY AND THEN START AN
INCREASE OF POPS THROUGH THE AFTERNOON AND MORE SO OVERNIGHT INTO
TUESDAY.
AN AREA OF LOW PRESSURE DEVELOPS ACROSS THE SOUTHEASTERN UNITED
STATES AND TRACKS TOWARD OUR REGION ON TUESDAY. THIS LOW LOOKS LIKE
IT BECOMES ENVELOPED INTO THE APPROACHING FRONTAL SYSTEM AS IT MOVES
NORTHEAST.
A COLD FRONT WILL APPROACH FROM THE WEST AND MOVE THROUGH LATE
TUESDAY NIGHT INTO WEDNESDAY. WITH THE INCREASING MOISTURE IN THE
WAA AHEAD OF THE SURFACE COLD FRONT TO OUR WEST, WE SEE PWATS
INCREASE UP TO AROUND 2 INCHES. THIS KEEPS THE INCREASED CHANCES FOR
HEAVY RAIN ACROSS THE REGION. FOR NOW, CONVECTION LOOKS LIKE IT
MIGHT BE LIMITED TO RIGHT ALONG THE FRONT WHERE THE BEST LIFT WILL
BE AND CONVECTION HAS BEEN MENTIONED BUT REMAINS SCATTERED OR
ISOLATED.
THE FRONT QUICKLY PUSHES THROUGH THE REGION AND WE SHOULD START TO
CLEAR OUT AND DRY OUT THROUGH THE DAY ON WEDNESDAY FROM WEST TO
EAST. ANOTHER AREA OF HIGH PRESSURE BUILDS IN BEHIND THE FRONT AND
THEN LASTS THROUGH MUCH OF THE REST OF THE WEEK.
TEMPERATURES WILL BE SLIGHTLY BELOW OR NEAR NORMAL THROUGH THE
EXTENDED PERIOD.
&&
.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
VFR CONDITIONS CONTINUE THIS EVENING WITH MAINLY MID AND HIGH
CLOUDINESS. A COLD FRONT STRETCHED ACROSS WESTERN NEW YORK STATE AND
WESTERN PENNSYLVANIA SHOULD CROSS THE LEHIGH VALLEY ABOUT 0600
UTC...PASS KPHL ABOUT 0800 UTC...AND EXIT THE COAST CLOSE TO 1100
UTC. AHEAD OF THE FRONT...A LIGHT SOUTH TO SOUTHWEST FLOW WILL
PERSIST...AND THIS SHOULD PREVENT PATCHY MVFR FOG FROM FORMING IN
PLACES LIKE KRDG AND KMIV.
THE BULK OF THE SHOWER ACTIVITY SHOULD PASS NORTH OF THE AREA...WITH
KABE HAVING THE BEST CHANCE OF SEEING ANY VFR RAIN SHOWERS. VFR
CEILINGS BETWEEN 4000 AND 6000 FEET SHOULD ACCOMPANY THE FRONT...AND
LINGER FOR A COUPLE OF HOURS AFTER THE FRONTAL PASSAGE. BEHIND THE
FRONT...WINDS SHOULD BECOME NORTH...BUT SPEEDS SHOULD REMAIN BELOW
10 KNOTS THROUGH SUNRISE.
VFR CONDITIONS ARE EXPECTED SATURDAY. AFTER THE STRATOCUMULUS DECK
EXITS IN THE MORNING...ONLY SCATTERED CLOUDS ARE EXPECTED FOR THE
BALANCE OF THE DAY. THE NORTHERLY WIND GRADIENT TIGHTENS DURING THE
MORNING...AND A FEW LOCATIONS (LIKE KPHL AND KACY) SHOULD SEE GUSTS
NEAR 20 KNOTS BETWEEN ABOUT 1400 UTC AND 1900 UTC. THE GUSTINESS
SHOULD BACK OFF BEFORE 0000 UTC SUNDAY.
OUTLOOK...
SATURDAY NIGHT AND SUNDAY...VFR CONDITIONS EXPECTED. NORTHWEST WINDS
WILL BECOME MORE SOUTHWESTERLY THROUGH SUNDAY WHILE REMAINING AROUND
10 KNOTS OR LESS.
MONDAY AND TUESDAY...VFR TO START ON MONDAY THEN DETERIORATING
CONDITIONS AS A COLD FRONT PUSHES TOWARD THE AREA, MOVING THROUGH
LATE TUESDAY. SUB-VFR CONDITIONS POSSIBLE, ESPECIALLY FROM MONDAY
AFTERNOON ONWARD AS LOW LEVEL MOISTURE INCREASES AND SHOWERS BEGIN
TO DEVELOP. WINDS WILL BE OUT OF THE SOUTH THROUGH TUESDAY SHIFTING
TO THE WEST TUESDAY NIGHT. WINDS MAY ALSO BECOME GUSTY LATE TUESDAY.
WEDNESDAY...MVFR/IFR CONDITIONS WILL IMPROVE AS THE COLD FRONT
PUSHES TO OUR EAST. ANY LINGERING SHOWERS SHOULD CLEAR OUT BY EARLY
AFTERNOON AND A RETURN TO VFR BY THE LATE AFTERNOON CAN BE
EXPECTED. WEST TO NORTHWEST WINDS WILL CONTINUE ON WEDNESDAY WITH
SPEEDS AROUND 10 TO 15 KNOTS. WINDS START TO SUBSIDE INTO
WEDNESDAY EVENING.
&&
.MARINE...
IT APPEARS AS THOUGH THE LOW LEVEL PRESSURE GRADIENT HAS BEEN
AUGMENTED BY LOCAL SEA AND BAY BREEZES...AS WINDS ARE GUSTING ABOVE
15 KNOTS OVER THE DELAWARE BAY AND PORTIONS OF THE NEW JERSEY COAST.
THE UPDATED FORECAST ACCOUNTED FOR THIS. HOWEVER...THE EFFECT
APPEARS TO BE LINGERING LATER INTO THE EVENING...AND THE FORECAST
WILL BE UPDATED TO ACCOUNT FOR THE CHANGE.
THERE COULD BE SOME GUSTS NEAR 20 KNOTS AS WINDS SHIFT TO THE NORTH
LATE TONIGHT BEHIND THE FRONT (THERE HAS BEEN SOME GUSTINESS WITH
THE FRONT OVER LAND ACROSS WESTERN PENNSYLVANIA). WHILE THERE COULD
BE A LOW LEVEL PUSH...WINDS ARE EXPECTED TO REMAIN BELOW 25 KNOTS
TONIGHT.
A DRY COLD FRONT FROM THE WEST IS FORECAST TO ARRIVE LATE
TONIGHT, FOLLOWED BY ANOTHER AREA OF HIGH PRESSURE FOR SATURDAY.
WIND SPEEDS AND WAVE HEIGHTS WILL REMAIN BELOW THE SMALL CRAFT
ADVISORY CRITERIA DURING SATURDAY.
OUTLOOK...
SEAS BUILD OVER THE WEEKEND TO AROUND 5 FEET AND A SMALL CRAFT
ADVISORY MAY BE NEEDED FOR SUNDAY. SEAS SUBSIDE AS HIGH PRESSURE
BUILDS OVERHEAD EARLY IN THE WEEK. HOWEVER, SEAS WILL START TO RISE
AGAIN LATE ON MONDAY INTO TUESDAY AS A WARM FRONT MAKES IT WAY
NORTHWARD AND THROUGH OUR AREA. WITH A SOUTHERLY FLOW IN PLACE, SEAS
WILL START TO RISE TO NEAR 5 FEET BY EARLY TUESDAY AND WILL CONTINUE
TO INCREASE THROUGH THE DAY. WITH THE GRADIENT TIGHTENING UP AS A
COLD FRONT APPROACHES FROM THE WEST FOR TUESDAY, WINDS WILL BECOME
INCREASINGLY GUSTIER OVER OUR AREA WATERS. GUSTS LOOK TO REMAIN
AROUND 30 KNOTS ON TUESDAY INTO WEDNESDAY BUT GUST UP TO GALE
FORCE REMAIN A POSSIBILITY. WAVEWATCH PUSHES SEAS UP AROUND 8 OR
9 FEET ON TUESDAY AND EVEN THOUGH THE WINDS LOOK TO BE PRETTY
ROBUST, WE DECIDED TO TONE IT DOWN JUST A BIT. A SMALL CRAFT
ADVISORY LOOKS LIKE IT WILL BE NEEDED FOR TUESDAY AND CONTINUING
INTO WEDNESDAY.
&&
.RIP CURRENTS...
WITH A 7 TO 10 SECOND WAVE PERIOD ALONG THE COASTS OF NEW JERSEY
AND DELAWARE AND WITH WAVE HEIGHTS IN THE 1 TO 2 FOOT RANGE, WE
WILL CARRY A LOW RISK OF RIP CURRENTS FOR THE BALANCE OF THE DAY.
THE WIND WILL REMAIN LIGHT AND IT SHOULD BEGIN TO FAVOR THE SOUTH
AND SOUTHEAST.
FOR SATURDAY...UNCERTAINTY AS SOLUTIONS RANGE FROM LOW TO MDT
DEPENDING ON THE PREDOMINANT PERIOD...BE IT A 1 FT 17 SEC
FORERUNNER ARRIVING FROM NADINE OR 2 FT 8 SEC.
THERE IS A HIGH PROBABILITY FOR AT LEAST A MODERATE RISK OF
DANGEROUS RIP CURRENTS SUNDAY THROUGH TUESDAY.
A 4 FT 14 SECOND SE SWELL IS STILL OUTLOOKED FOR SUNDAY FROM THE
00Z/14 WW3 AND THEN THAT EASES TO A 3 FT 12 SEC ESE SWELL MONDAY.
TUESDAY IS A PROBABLE STRENGTHENING CFP AND EITHER WAY...3 FT 10
SEC LEFTOVERS FROM NADINE OR A SOUTHERLY PRE-CFP 6 FT 6 SEC
SWELL... BOTH OPTIONS SUGGEST A MDT RISK.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MEOLA
NEAR TERM...HAYES
SHORT TERM...IOVINO
LONG TERM...MEOLA
AVIATION...HAYES/MEOLA
MARINE...IOVINO/HAYES/MEOLA
RIP CURRENTS...
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
352 PM CDT THU SEP 13 2012
...UPDATED SHORT TERM SECTION...
.SYNOPSIS...
ISSUED AT 1151 AM CDT THU SEP 13 2012
LATE MORNING WATER VAPOR LOOP AND RAP ANALYSIS SHOWED THE NORTHERN
STREAM MID LEVEL TROUGH AXIS MOVING INTO THE UPPER GREAT LAKES
REGION...WHICH EXTENDED SOUTHWEST INTO WESTERN KANSAS...MEETING A
DISTURBANCE WITH SUBTROPICAL CHARACTERISTICS OVER CENTRAL NEW
MEXICO. 12Z 700MB RAOB ANALYSIS SHOWED DEWPOINTS OF 4 TO 6 DEGC AT
EL PASO, MIDLAND, AMARILLO TX AND NORMAN, OK. THE SURFACE COLD FRONT
TIED TO THE OLD STORM THAT MOVED ACROSS CANADA OVER THE LAST COUPLE
OF DAYS HAD PUSHED WELL INTO TEXAS EXTENDING FROM JUST NORTH OF DEL
RIO TO AROUND MINERAL WELLS, TX AT 13Z. A 1031MB SURFACE HIGH WAS
ANALYZED ON THE 13Z ANALYSIS WITH TEMPERATURES BOTTOMING OUT IN THE
MID TO UPPER 30S ACROSS THE SAND HILLS OF NEBRASKA (NORTH PLATTE, NE
HAD A LOW OF 35 DEGREES). THE PRECIPITATION EVENT WHICH WAS TIED TO
THE MID LEVEL FRONTOGENETIC ZONE CONTINUED FROM PORTIONS OF WEST AND
NORTHWEST TEXAS INTO WESTERN OKLAHOMA AND SOUTH CENTRAL KANSAS. MORE
SPECIFICALLY CLOSER TO HOME AS OF 16Z...THE BACK EDGE OF THE
PRECIPITATION EXTENDED FROM BEAVER, OK TO GREENSBURG, KS TO GREAT
BEND, KS. LOW CLOUDS WERE DISSIPATING NOT TOO FAR NORTHWEST OF THIS
LINE...HOWEVER HIGH LEVEL CLOUD COVER CONTINUED ALL THE WAY
NORTHWEST TO A LAMAR, CO TO MCCOOK, NE LINE.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 351 PM CDT THU SEP 13 2012
THE NORTHWEST EDGE OF THE PRECIPITATION AREA WILL SLOWLY SHIFT
SOUTHEAST THROUGH THE EVENING...AND PER LATEST HIGH RESOLUTION
SIMULATED REFLECTIVITY PROGS...SHOULD BE EXITING COMANCHE AND BARBER
COUNTIES BY AROUND 03Z THIS EVENING. A COMPLICATING FACTOR HOWEVER
IS THE SPIN-UP OF THE MID LEVEL VORTICITY CENTER OVER WEST TEXAS
TONIGHT INTO EARLY FRIDAY...WHICH WILL ACT TO HALT THE 700-500MB
DEFORMATION ZONE...AND PERHAPS SHIFT IT BACK NORTHWARD 30 OR SO
MILES. WILL HAVE TO KEEP SOME CHANCE POPS IN THE FAR SOUTH CENTRAL
KANSAS AREAS...MAINLY SOUTHEASTERN CLARK AND SOUTHERN COMANCHE AND
BARBER COUNTIES. THERE WILL BE A GRADIENT IN CLOUD COVER AS
WELL...WITH SKY CLEARING QUICKLY NORTH OF THE PRECIPITATION AREA.
THE CLEARED OUT AREAS WILL SEE WINDS DIMINISHING TO LESS THAN 8
KNOTS TONIGHT AS 1030MB SURFACE HIGH SHIFTS SOUTH INTO WEST CENTRAL
KANSAS BY 12Z FRIDAY. GIVEN THE COOL START TO THE `TONIGHT`
PERIOD...SHOULD SEE TEMPERATURES BOTTOM OUT IN THE 43 TO 46F RANGE
OVER MANY AREAS NORTHWEST OF A HUGOTON TO DODGE CITY TO LARNED
LINE. IT WON`T BE SURPRISING TO SEE SOME CREEK/STREAM VALLEY AREAS
SEE LOWS DOWN TO AROUND 40...ESPECIALLY IN THE SYRACUSE TO SCOTT
CITY TO COLLYER AREAS. DEWPOINTS WILL BE FALLING INTO THE 30S...SO
THE PROBABILITY OF LOWER VISIBILITIES AT DAYBREAK WILL BE FAIRLY
LOW...AND FOG FORMATION DOES NOT APPEAR LIKELY.
ON FRIDAY...WILL CONTINUE THE NOTION OF WARMER NORTH...COOLER SOUTH
WITH HIGHS FRIDAY NEAR THE OKLAHOMA BORDER FROM MEADE STATE PARK TO
KIOWA IN THE MID TO UPPER 60S. AREAS ALONG I-70 SHOULD SEE
AFTERNOON TEMPERATURES PEAKING IN THE UPPER 70S UNDER MOSTLY CLEAR
SKY. THE SURFACE RIDGE AXIS WILL REMAIN CONFINED TO A
WEST-SOUTHWEST TO EAST NORTHEAST AXIS ACROSS KANSAS WITH LIGHT WINDS
THROUGHOUT THE DAY FRIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 123 PM CDT THU SEP 13 2012
MEDIUM RANGE MODELS INDICATE A POSITIVELY TILTED UPPER LEVEL
TROUGH OF LOW PRESSURE STRETCHED ACROSS THE SOUTH PLAINS AND
PORTIONS OF THE DESERT SOUTHWEST EARLY IN THE PERIOD FRIDAY NIGHT.
THE UPPER LEVEL TROUGH IS PROGGED TO BEGIN PUSHING SLOWLY EASTWARD
ACROSS WEST TEXAS THROUGHOUT THE WEEKEND KEEPING ANY PRECIP CHANCES
JUST OFF TO OUR SOUTH AND SOUTHEAST ACROSS OKLAHOMA AND TEXAS. ALONG
WITH A LACK OF AVAILABLE LOW LEVEL MOISTURE, LOOK FOR MOSTLY DRY
CONDITIONS TO PREVAIL ACROSS WESTERN KANSAS THROUGH AT LEAST SUNDAY
NIGHT. THE GFS, GEM, AND ECMWF THEN GENERALLY SHOW A LARGE SCALE
UPPER LEVEL TROUGH DROPPING SOUTH OUT OF CANADA INTO THE NORTHERN
PLAINS AND THE EXTREME WESTERN GREAT LAKES REGION EARLY NEXT WEEK
THIS WILL BRING THE POSSIBILITY FOR PRECIP TO THE CENTRAL PLAINS,
INCLUDING PORTIONS OF CENTRAL AND WESTERN KANSAS, AS AN ATTENDANT
COLD FRONT SURGES SOUTHWARD INTO THE REGION. THE PRIMARY ISSUES
THIS FAR OUT THOUGH INCLUDE THE TIMING AND STRENGTH OF THE SYSTEM
AS WELL AS THE AVAILABILITY OF LOW/MID LEVEL MOISTURE FOR THE
SYSTEM TO WORK WITH. DUE TO THIS UNCERTAINTY, SLIGHT POPS REMAIN
REASONABLE FOR MONDAY.
TEMPERATURES WILL BE NEAR NORMAL SATURDAY AS THE WARMING TREND
CONTINUES INTO THE WEEKEND. FOR SATURDAY, A LEE SIDE TROUGH OF LOW
PRESSURE IS EXPECTED TO DEVELOP ACROSS EASTERN COLORADO HELPING TO
INFLUENCE MORE OF A SOUTHERLY FLOW ACROSS WESTERN KANSAS. THIS
WILL DRAW SLIGHTLY WARMER AIR INTO THE AREA WITH H85 TEMPERATURES
RANGING FROM THE MID TEENS(C) ACROSS CENTRAL KANSAS TO NEAR 20C
ALONG THE COLORADO BORDER. WIDESPREAD 70S(F) CAN BE EXPECTED
SATURDAY AFTERNOON WITH NEAR 80F NOT OUT OF THE QUESTION.
SOUTHERLY WINDS WILL CONTINUE ACROSS WESTERN KANSAS SUNDAY HELPING
TO ADVECT WARMER AIR NORTHWARD INTO THE STATE. THE GEM, GFS AND
ECMWF SHOW H85 TEMPERATURES RANGING FROM THE UPPER TEENS(C) TO
NEAR 20C ACROSS CENTRAL KANSAS TO NEAR 25C IN FAR SOUTHWEST KANSAS.
ALONG WITH PLENTY OF SUNSHINE EXPECTED, LOOK FOR HIGHS UP INTO THE
LOW TO MID 80S(F) SUNDAY AFTERNOON. COOLER TEMPERATURES ARE LIKELY
EARLY NEXT WEEK AS A RESULT OF THE COLD FRONT PROJECTED TO DROP
SOUTHWARD INTO WESTERN KANSAS SOMETIME EARLY TO MID DAY MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1151 AM CDT THU SEP 13 2012
CEILING HAD IMPROVED AT GCK AND HYS AS SUBSIDENCE WAS BUILDING SOUTH
WITH THE STORM SYSTEM MOVING AWAY. DDC CONTINUED WITH MVFR CEILING
AS OF 16Z...HOWEVER THIS CEILING WILL SCATTER OUT BY EARLY AFTERNOON
WITH VFR CONDITIONS TAKING OVER FROM EARLY AFTERNOON THROUGH TONIGHT
AND BEYOND. WINDS WILL SLOWLY DECREASE TO 8 TO 10 KNOTS BY LATE THIS
AFTERNOON/EARLY THIS EVENING...AND CONTINUE TO DECREASE TO AROUND 5
TO 7 KNOTS THROUGH THE NIGHT TONIGHT. AT THIS TIME...NO REDUCTION IN
VISIBILITY IS EXPECTED DURING THE DAYBREAK TIME FRAME EARLY FRIDAY
MORNING DESPITE TEMPERATURES LIKELY BOTTOMING OUT AROUND THE MID 40S.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 45 73 46 76 / 10 0 0 0
GCK 43 74 46 77 / 10 0 0 0
EHA 46 71 46 77 / 10 0 0 0
LBL 47 70 47 76 / 10 0 0 0
HYS 44 77 46 77 / 10 0 0 0
P28 49 65 50 75 / 40 20 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...UMSCHEID
LONG TERM...JJOHNSON
AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
133 PM CDT THU SEP 13 2012
...UPDATE TO LONG TERM...
.SYNOPSIS...
ISSUED AT 1151 AM CDT THU SEP 13 2012
LATE MORNING WATER VAPOR LOOP AND RAP ANALYSIS SHOWED THE NORTHERN
STREAM MID LEVEL TROUGH AXIS MOVING INTO THE UPPER GREAT LAKES
REGION...WHICH EXTENDED SOUTHWEST INTO WESTERN KANSAS...MEETING A
DISTURBANCE WITH SUBTROPICAL CHARACTERISTICS OVER CENTRAL NEW
MEXICO. 12Z 700MB RAOB ANALYSIS SHOWED DEWPOINTS OF 4 TO 6 DEGC AT
EL PASO, MIDLAND, AMARILLO TX AND NORMAN, OK. THE SURFACE COLD FRONT
TIED TO THE OLD STORM THAT MOVED ACROSS CANADA OVER THE LAST COUPLE
OF DAYS HAD PUSHED WELL INTO TEXAS EXTENDING FROM JUST NORTH OF DEL
RIO TO AROUND MINERAL WELLS, TX AT 13Z. A 1031MB SURFACE HIGH WAS
ANALYZED ON THE 13Z ANALYSIS WITH TEMPERATURES BOTTOMING OUT IN THE
MID TO UPPER 30S ACROSS THE SAND HILLS OF NEBRASKA (NORTH PLATTE, NE
HAD A LOW OF 35 DEGREES). THE PRECIPITATION EVENT WHICH WAS TIED TO
THE MID LEVEL FRONTOGENETIC ZONE CONTINUED FROM PORTIONS OF WEST AND
NORTHWEST TEXAS INTO WESTERN OKLAHOMA AND SOUTH CENTRAL KANSAS. MORE
SPECIFICALLY CLOSER TO HOME AS OF 16Z...THE BACK EDGE OF THE
PRECIPITATION EXTENDED FROM BEAVER, OK TO GREENSBURG, KS TO GREAT
BEND, KS. LOW CLOUDS WERE DISSIPATING NOT TOO FAR NORTHWEST OF THIS
LINE...HOWEVER HIGH LEVEL CLOUD COVER CONTINUED ALL THE WAY
NORTHWEST TO A LAMAR, CO TO MCCOOK, NE LINE.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 313 AM CDT THU SEP 13 2012
THE AFOREMENTIONED TROUGH WILL CONTINUE TO DRIVE THE SENSIBLE
WEATHER ACROSS WESTERN AND CENTRAL KANSAS FOR THE NEXT 18 HOURS.
INITIALLY, THE CURRENT RAIN BAND WILL ADVECT SLOWLY EASTWARD, BEING
MAINTAINED BY PERSISTENT ISENTROPIC LIFT WITHIN THE TROUGH AXIS.
THE ISENTROPIC DOWNWARD OMEGA ZONE WILL APPROXIMATE THE BACK EDGE
OF THE SHOWER BAND, AND WILL PROBABLY BE LOCATED FROM ABOUT A HAYS
TO GARDEN CITY AND HUGOTON LINE BY 12 UTC. THE ISENTROPIC LIFT ZONE
WILL THEN SLOWLY PERSIST EASTWARD INTO SOUTH CENTRAL KANSAS INTO
THIS EVENING, BRINGING THE ENTIRE AREA MEASURABLE RAINFALL BETWEEN
TWO TENTHS AND A HALF INCH (AND LOCALLY HIGHER AMOUNTS). ALTHOUGH
THE CURRENT RADAR RETURNS ARE SLOWLY DIMINISHING, THE MODELS
CONTINUE TO DEVELOP ADDITIONAL ISENTROPIC LIFT PRECIPITATION LATER
THIS MORNING. OVERNIGHT LOWS COULD BECOME A CHALLENGE TONIGHT. THE
NAM IS SIGNIFICANTLY WARMER THAN WHAT THE CURRENT FORECAST DATABASE
HAD INDICATED, POSSIBLY DUE TO AN AIRMASS CHANGE THAT WILL OCCUR
BEHIND THE TROUGH. THE AIR WON`T BE THE SAME RAIN COOLED AIRMASS
FROM THE DAY, AND THESE WARMER TEMPERATURES ARE PLAUSIBLE. STRATUS
COULD REDEVELOP ANYWHERE ACROSS CENTRAL KANSAS AS WELL BUT THE
NORTHEAST WIND TRAJECTORIES DON`T SEEM TO HEAVILY FAVOR WIDESPREAD
FOG. WE WILL PROBABLY HEDGE LOW TEMPERATURES SOMEWHERE BETWEEN THE
TWO SOLUTIONS AT THIS POINT.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 123 PM CDT THU SEP 13 2012
MEDIUM RANGE MODELS INDICATE A POSITIVELY TILTED UPPER LEVEL
TROUGH OF LOW PRESSURE STRETCHED ACROSS THE SOUTH PLAINS AND
PORTIONS OF THE DESERT SOUTHWEST EARLY IN THE PERIOD FRIDAY NIGHT.
THE UPPER LEVEL TROUGH IS PROGGED TO BEGIN PUSHING SLOWLY EASTWARD
ACROSS WEST TEXAS THROUGHOUT THE WEEKEND KEEPING ANY PRECIP CHANCES
JUST OFF TO OUR SOUTH AND SOUTHEAST ACROSS OKLAHOMA AND TEXAS. ALONG
WITH A LACK OF AVAILABLE LOW LEVEL MOISTURE, LOOK FOR MOSTLY DRY
CONDITIONS TO PREVAIL ACROSS WESTERN KANSAS THROUGH AT LEAST SUNDAY
NIGHT. THE GFS, GEM, AND ECMWF THEN GENERALLY SHOW A LARGE SCALE
UPPER LEVEL TROUGH DROPPING SOUTH OUT OF CANADA INTO THE NORTHERN
PLAINS AND THE EXTREME WESTERN GREAT LAKES REGION EARLY NEXT WEEK
THIS WILL BRING THE POSSIBILITY FOR PRECIP TO THE CENTRAL PLAINS,
INCLUDING PORTIONS OF CENTRAL AND WESTERN KANSAS, AS AN ATTENDANT
COLD FRONT SURGES SOUTHWARD INTO THE REGION. THE PRIMARY ISSUES
THIS FAR OUT THOUGH INCLUDE THE TIMING AND STRENGTH OF THE SYSTEM
AS WELL AS THE AVAILABILITY OF LOW/MID LEVEL MOISTURE FOR THE
SYSTEM TO WORK WITH. DUE TO THIS UNCERTAINTY, SLIGHT POPS REMAIN
REASONABLE FOR MONDAY.
TEMPERATURES WILL BE NEAR NORMAL SATURDAY AS THE WARMING TREND
CONTINUES INTO THE WEEKEND. FOR SATURDAY, A LEE SIDE TROUGH OF LOW
PRESSURE IS EXPECTED TO DEVELOP ACROSS EASTERN COLORADO HELPING TO
INFLUENCE MORE OF A SOUTHERLY FLOW ACROSS WESTERN KANSAS. THIS
WILL DRAW SLIGHTLY WARMER AIR INTO THE AREA WITH H85 TEMPERATURES
RANGING FROM THE MID TEENS(C) ACROSS CENTRAL KANSAS TO NEAR 20C
ALONG THE COLORADO BORDER. WIDESPREAD 70S(F) CAN BE EXPECTED
SATURDAY AFTERNOON WITH NEAR 80F NOT OUT OF THE QUESTION.
SOUTHERLY WINDS WILL CONTINUE ACROSS WESTERN KANSAS SUNDAY HELPING
TO ADVECT WARMER AIR NORTHWARD INTO THE STATE. THE GEM, GFS AND
ECMWF SHOW H85 TEMPERATURES RANGING FROM THE UPPER TEENS(C) TO
NEAR 20C ACROSS CENTRAL KANSAS TO NEAR 25C IN FAR SOUTHWEST KANSAS.
ALONG WITH PLENTY OF SUNSHINE EXPECTED, LOOK FOR HIGHS UP INTO THE
LOW TO MID 80S(F) SUNDAY AFTERNOON. COOLER TEMPERATURES ARE LIKELY
EARLY NEXT WEEK AS A RESULT OF THE COLD FRONT PROJECTED TO DROP
SOUTHWARD INTO WESTERN KANSAS SOMETIME EARLY TO MID DAY MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1151 AM CDT THU SEP 13 2012
CEILING HAD IMPROVED AT GCK AND HYS AS SUBSIDENCE WAS BUILDING SOUTH
WITH THE STORM SYSTEM MOVING AWAY. DDC CONTINUED WITH MVFR CEILING
AS OF 16Z...HOWEVER THIS CEILING WILL SCATTER OUT BY EARLY AFTERNOON
WITH VFR CONDITIONS TAKING OVER FROM EARLY AFTERNOON THROUGH TONIGHT
AND BEYOND. WINDS WILL SLOWLY DECREASE TO 8 TO 10 KNOTS BY LATE THIS
AFTERNOON/EARLY THIS EVENING...AND CONTINUE TO DECREASE TO AROUND 5
TO 7 KNOTS THROUGH THE NIGHT TONIGHT. AT THIS TIME...NO REDUCTION IN
VISIBILITY IS EXPECTED DURING THE DAYBREAK TIME FRAME EARLY FRIDAY
MORNING DESPITE TEMPERATURES LIKELY BOTTOMING OUT AROUND THE MID 40S.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 47 73 48 76 / 10 0 0 0
GCK 44 74 48 77 / 10 0 0 0
EHA 46 71 48 77 / 10 0 0 0
LBL 48 70 49 76 / 10 0 0 0
HYS 44 77 48 77 / 10 0 0 0
P28 51 65 52 75 / 30 20 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...RUSSELL
LONG TERM...JJOHNSON
AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1152 AM CDT THU SEP 13 2012
...UPDATED AVIATION AND SYNOPSIS SECTIONS...
.SYNOPSIS...
ISSUED AT 1151 AM CDT THU SEP 13 2012
LATE MORNING WATER VAPOR LOOP AND RAP ANALYSIS SHOWED THE NORTHERN
STREAM MID LEVEL TROUGH AXIS MOVING INTO THE UPPER GREAT LAKES
REGION...WHICH EXTENDED SOUTHWEST INTO WESTERN KANSAS...MEETING A
DISTURBANCE WITH SUBTROPICAL CHARACTERISTICS OVER CENTRAL NEW
MEXICO. 12Z 700MB RAOB ANALYSIS SHOWED DEWPOINTS OF 4 TO 6 DEGC AT
EL PASO, MIDLAND, AMARILLO TX AND NORMAN, OK. THE SURFACE COLD FRONT
TIED TO THE OLD STORM THAT MOVED ACROSS CANADA OVER THE LAST COUPLE
OF DAYS HAD PUSHED WELL INTO TEXAS EXTENDING FROM JUST NORTH OF DEL
RIO TO AROUND MINERAL WELLS, TX AT 13Z. A 1031MB SURFACE HIGH WAS
ANALYZED ON THE 13Z ANALYSIS WITH TEMPERATURES BOTTOMING OUT IN THE
MID TO UPPER 30S ACROSS THE SAND HILLS OF NEBRASKA (NORTH PLATTE, NE
HAD A LOW OF 35 DEGREES). THE PRECIPITATION EVENT WHICH WAS TIED TO
THE MID LEVEL FRONTOGENETIC ZONE CONTINUED FROM PORTIONS OF WEST AND
NORTHWEST TEXAS INTO WESTERN OKLAHOMA AND SOUTH CENTRAL KANSAS. MORE
SPECIFICALLY CLOSER TO HOME AS OF 16Z...THE BACK EDGE OF THE
PRECIPITATION EXTENDED FROM BEAVER, OK TO GREENSBURG, KS TO GREAT
BEND, KS. LOW CLOUDS WERE DISSIPATING NOT TOO FAR NORTHWEST OF THIS
LINE...HOWEVER HIGH LEVEL CLOUD COVER CONTINUED ALL THE WAY
NORTHWEST TO A LAMAR, CO TO MCCOOK, NE LINE.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 313 AM CDT THU SEP 13 2012
THE AFOREMENTIONED TROUGH WILL CONTINUE TO DRIVE THE SENSIBLE
WEATHER ACROSS WESTERN AND CENTRAL KANSAS FOR THE NEXT 18 HOURS.
INITIALLY, THE CURRENT RAIN BAND WILL ADVECT SLOWLY EASTWARD, BEING
MAINTAINED BY PERSISTENT ISENTROPIC LIFT WITHIN THE TROUGH AXIS.
THE ISENTROPIC DOWNWARD OMEGA ZONE WILL APPROXIMATE THE BACK EDGE
OF THE SHOWER BAND, AND WILL PROBABLY BE LOCATED FROM ABOUT A HAYS
TO GARDEN CITY AND HUGOTON LINE BY 12 UTC. THE ISENTROPIC LIFT ZONE
WILL THEN SLOWLY PERSIST EASTWARD INTO SOUTH CENTRAL KANSAS INTO
THIS EVENING, BRINGING THE ENTIRE AREA MEASURABLE RAINFALL BETWEEN
TWO TENTHS AND A HALF INCH (AND LOCALLY HIGHER AMOUNTS). ALTHOUGH
THE CURRENT RADAR RETURNS ARE SLOWLY DIMINISHING, THE MODELS
CONTINUE TO DEVELOP ADDITIONAL ISENTROPIC LIFT PRECIPITATION LATER
THIS MORNING. OVERNIGHT LOWS COULD BECOME A CHALLENGE TONIGHT. THE
NAM IS SIGNIFICANTLY WARMER THAN WHAT THE CURRENT FORECAST DATABASE
HAD INDICATED, POSSIBLY DUE TO AN AIRMASS CHANGE THAT WILL OCCUR
BEHIND THE TROUGH. THE AIR WON`T BE THE SAME RAIN COOLED AIRMASS
FROM THE DAY, AND THESE WARMER TEMPERATURES ARE PLAUSIBLE. STRATUS
COULD REDEVELOP ANYWHERE ACROSS CENTRAL KANSAS AS WELL BUT THE
NORTHEAST WIND TRAJECTORIES DON`T SEEM TO HEAVILY FAVOR WIDESPREAD
FOG. WE WILL PROBABLY HEDGE LOW TEMPERATURES SOMEWHERE BETWEEN THE
TWO SOLUTIONS AT THIS POINT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 313 AM CDT THU SEP 13 2012
FOR FRIDAY A LINGERING UPPER LOW OVER CENTRAL KANSAS COULD KEEP SOME
LINGERING LIGHT RAIN SHOWERS IN OUR SOUTHEASTERN FA FROM COLDWATER
TO PRATT AND COOLER HIGH TEMPERATURES. THEN FOR SATURDAY AS THE
UPPER LOW MOVES EAST INTO THE OHIO VALLEY SOUTH WINDS RETURN WITH A
WARM FRONT MOVING ACROSS WESTERN KANSAS ON SUNDAY AHEAD OF AN UPPER
LEVEL SHORTWAVE TROUGH MOVING INTO THE NORTHERN PLAINS. A STRONG
UPPER LEVEL TROUGH THEN DIGS INTO THE CENTRAL PLAINS ON MONDAY
BRINGING A COLD FRONT ACROSS WESTERN KANSAS. WILL KEEP A SMALL POP
FOR SHOWERS AND THUNDERSTORMS WITH AND BEHIND THE COLD FRONT FOR
MONDAY. THE STRONG UPPER LOW AND TROUGH MOVE EAST INTO THE UPPER
MIDWEST AND OHIO VALLEY ON TUESDAY WHILE THE NEW CANADIAN HAS A LONG
WAVE TROUGH LINGERING FROM THE NORTHERN PLAINS INTO THE SOUTHERN
PLAINS. THE CANADIAN MODEL LOOKS TO BE THE ODD MODEL OUT AT THIS
TIME COMPARED TO THE GFS AND ECMWF. THEN FOR WEDNESDAY ANOTHER UPPER
LEVEL SHORTWAVE TROUGH MOVES OUT OF CENTRAL CANADA AND INTO THE
NORTHERN PLAINS. ANOTHER WARM UP IS FORECAST AHEAD OF THE WAVE ON
WEDNESDAY.
OVERNIGHT LOWS FALL INTO THE 40S ON SATURDAY MORNING THEN WARM INTO
THE 50S THROUGH THE MIDDLE OF NEXT WEEK. DAYTIME HIGHS LOOK TO WARM
FROM AROUND 70 ON FRIDAY TO THE LOW TO MID 80S ON SUNDAY WITH A WARM
FRONT. ON MONDAY A COLD FRONT WILL LOWER HIGHS INTO THE 70S WITH A
GRADUAL WARMING TREND INTO NEXT WEDNESDAY BACK INTO THE 80S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1151 AM CDT THU SEP 13 2012
CEILING HAD IMPROVED AT GCK AND HYS AS SUBSIDENCE WAS BUILDING SOUTH
WITH THE STORM SYSTEM MOVING AWAY. DDC CONTINUED WITH MVFR CEILING
AS OF 16Z...HOWEVER THIS CEILING WILL SCATTER OUT BY EARLY AFTERNOON
WITH VFR CONDITIONS TAKING OVER FROM EARLY AFTERNOON THROUGH TONIGHT
AND BEYOND. WINDS WILL SLOWLY DECREASE TO 8 TO 10 KNOTS BY LATE THIS
AFTERNOON/EARLY THIS EVENING...AND CONTINUE TO DECREASE TO AROUND 5
TO 7 KNOTS THROUGH THE NIGHT TONIGHT. AT THIS TIME...NO REDUCTION IN
VISIBILITY IS EXPECTED DURING THE DAYBREAK TIME FRAME EARLY FRIDAY
MORNING DESPITE TEMPERATURES LIKELY BOTTOMING OUT AROUND THE MID 40S.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 62 50 69 48 / 20 10 0 0
GCK 64 47 71 48 / 10 10 0 0
EHA 62 48 71 48 / 10 10 0 0
LBL 61 49 69 49 / 20 10 0 0
HYS 65 47 72 48 / 10 10 0 0
P28 58 50 68 52 / 100 30 20 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...RUSSELL
LONG TERM...KRUSE
AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS WICHITA KS
1147 PM CDT WED SEP 12 2012
.AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
AREAS OF RAIN WILL CONTINUE TO GRADUALLY SHIFT SOUTHEAST
OVERNIGHT...GETTING INTO THE KHUT-KICT BY 09-12Z...AS A STRONG
COLD FRONT SETTLES SOUTHEAST OVER SOUTHEAST KS. STRONG
NORTH/NORTHEAST WINDS WILL PREVAIL IN WAKE OF THE FRONT...AND COLD
ADVECTION WILL RESULT IN MVFR CIGS BELOW 2000 FT AGL...WITH PATCHY
IFR OVER MAINLY CENTRAL KS. RAIN CHANCES AND LOWER CIGS WILL
CONTINUE THROUGH THURSDAY FOR PRIMARILY KHUT-KICT.
ADK
&&
.PREV DISCUSSION... /ISSUED 938 PM CDT WED SEP 12 2012/
UPDATE...
STRONG COLD FRONT CONTINUES TO SURGE SOUTHEAST ACROSS THE FORECAST
AREA...QUITE A BIT FASTER THAN OPERATIONAL MODEL PROGS. FELT HRRR
AND RUC13 HAD THE BEST HANDLE ON THE SHORT-TERM TRENDS.
INITIAL ROUND OF SHOWERS/THUNDERSTORMS CURRENTLY EXITING OVER
EAST-CENTRAL KANSAS IS ASSOCIATED WITH THE SURFACE-850MB PORTION
OF THE COLD FRONT. THE MORE EXPANSIVE AREA OF PRECIPITATION WILL
CONTINUE TO SLOWLY TRANSITION SOUTHEAST INTO CENTRAL AND
EVENTUALLY SOUTH-CENTRAL KS AS THE NIGHT PROGRESSES. INSTABILITY
IS LACKING...SO NOT ANTICIPATING WIDESPREAD HEAVY RAIN...ALTHOUGH
ISOLATED LOCATIONS COULD APPROACH ONE-HALF INCH THROUGH SUNRISE.
WIDESPREAD RAINFALL AMOUNTS OF ONE/TWO-TENTHS OF AN INCH SEEMS
REASONABLE OVERNIGHT.
EXPECTING RAIN TO CONTINUE SHIFTING SLOWLY SOUTH THROUGH THE DAY
THURSDAY...AFFECTING SOUTH-CENTRAL/SOUTHEAST KS ALL DAY. LATEST
NAM IS NOW HINTING AT MID-LEVEL BAROCLINIC ZONE LINGERING A BIT
LONGER...WHICH COULD RESULT IN WIDESPREAD RAIN LINGERING OVER
SOUTHERN KANSAS THROUGH THURSDAY NIGHT.
ADK
PREV DISCUSSION... /ISSUED 649 PM CDT WED SEP 12 2012/
AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
WIDESPREAD RAIN/SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS WILL
GRADUALLY INCREASE FROM THE NORTHWEST THIS EVENING THROUGH TONIGHT
FOR ALL SITES EXCEPT KCNU...AS A STRONG COLD FRONT SURGES SOUTH
AND AN ASSOCIATED UPPER LEVEL TROUGH APPROACHES FROM THE
NORTHWEST. THUNDER CHANCES WILL BE GREATEST THIS EVENING FOR
KHUT-KSLN. STRONG/GUSTY NORTH WINDS WILL PREVAIL IMMEDIATELY
BEHIND THE COLD FRONT AS IT SURGES SOUTHEAST. ADDITIONALLY...CIGS
SHOULD GO MVFR BELOW 2000 FT AGL FOR ALL SITES EXCEPT KCNU
TONIGHT...WITH SCATTERED IFR CIGS FOR MAINLY KRSL-KSLN-KHUT.
ADK
PREV DISCUSSION... /ISSUED 318 PM CDT WED SEP 12 2012/
DISCUSSION...
MAIN FORECAST CHALLENGES ARE THE TIMING OF THE COLD FRONTAL PASSAGE
TONIGHT AND THE ASSOCIATED PRECIPITATION TONIGHT AND TOMORROW.
SYNOPSIS:
THE UPPER TROUGH AXIS IS SITUATED ACROSS THE INTER-MOUNTAIN WEST AND
IS SWINGING SOUTHEASTWARD TOWARD THE CENTRAL PLAINS. THIS WAVE WILL
BE THE MAIN WEATHER PRODUCER FOR THE NEXT FEW DAYS. THE SURFACE LOW
AND ASSOCIATED FRONT IS MOVING ACROSS THE CENTRAL PLAINS. IT HAS
SLOWED/STALLED OUT ACROSS CENTRAL KANSAS THIS MORNING/AFTERNOON.
THE WIND SHIFT IS JUST KNOCKING ON KRSL`S DOOR AS OF 3PM. SCATTERED
LIGHT SHOWERS THIS MORNING MOVED OFF TO THE NORTHEAST LEAVING MOSTLY
CLEAR SKIES...THAT IN COMBINATION WITH STOUT SOUTHERLY WINDS HAVE
ALLOWED TEMPS TO RISE INTO THE LOW TO MID 90S ACROSS MUCH OF THE
AREA...EXCEPT NEAREST THE FRONT. HOWEVER...SCATTERED MID-LEVEL
CLOUDS HAVE BEGUN TO DEVELOP OUT AHEAD OF THE SURFACE FRONT AND WILL
BE THE CONCERN FOR THIS AFTERNOON/EARLY EVENING.
TONIGHT - THURSDAY:
THE LATEST HIGHER RESOLUTION MODEL GUIDANCE (NAM/HRRR/RUC) CONTINUES
TO INDICATE SHOWER/THUNDERSTORM DEVELOPMENT AHEAD OF AND WITH THE
FRONT AS IT MOVES SOUTHWARD THIS EVENING. HAVE CUT BACK ON POPS
THROUGH 03Z THURSDAY OVER CENTRAL KANSAS...AND INCREASE IT GREATLY
FROM 03Z ON THROUGH THE NIGHT. INSTABILITY IS MARGINAL...BUT
INCREASES IN THE WARM SECTOR TOWARDS 00Z THURSDAY. SEVERE
THUNDERSTORMS ARE NOT EXPECTED...BUT SOME STRONGER STORMS COULD
DEVELOP IN THE MODEST CAPE/MINIMAL SHEAR REGION AHEAD OF THE FRONT.
THE MAIN CONCERN WILL BE ISOLATED STRONG WIND GUSTS. AS DRY AIR
FILTERS IN...INSTABILITY WILL BE ALL BUT SQUASHED.
THE FRONT IS EXPECTED TO MOVE SOUTHEAST FROM KRSL TO KICT AROUND
03-05Z AND THEN ON TO KCNU BY 10-12Z. HIGH PRESSURE HAS BUILT IN
BEHIND THE FRONT...INCREASING THE PRESSURE GRADIENT. AS THE FRONT
MOVES THROUGH WINDS WILL FLIRT WITH THE 30MPH WIND ADVISORY
CRITERIA. OBSERVING DAYTIME TRENDS...WINDS APPROACHED 30MPH...BUT DID
NOT EXCEED FOR LONG PERIODS OF TIME. REGARDLESS IT WILL BE WINDY
OUT OF THE NORTHEAST OVERNIGHT.
POST FRONTAL PRECIPITATION WILL CONTINUE THROUGH THE DAY THURSDAY
ENDING FROM NORTHWEST TO SOUTHEAST BY THURSDAY AFTERNOON.
WIDESPREAD PRECIPITATION ACCUMULATIONS OF 0.5 INCH TO 1 INCH ARE
EXPECTED WITH SOME AREAS SEEING HIGHER AMOUNTS. TEMPERATURES WILL
BE SIGNIFICANTLY COOLER BEHIND THE FRONT THURSDAY WITH AREAS UNDER
CLOUD COVER AND PRECIPITATION NOT MAKING IT OUT OF THE 60S. WHERE
THE SUN BREAKS OUT TEMPS WILL IMPROVE TO THE LOW 70S.
FRIDAY - SUNDAY:
THE WAVE THAT MOVES THROUGH WILL LEAVE BEHIND SOME ENERGY THAT WILL
MOVE IN FROM THE FOUR CORNERS REGION...TX/OK PANHANDLES AND WILL
IMPACT THE FORECAST INTO THE WEEKEND. IN ADDITION TO THE COOL
AIRMASS BEHIND THE FRONT...THIS ADDITIONAL SYSTEM WILL KEEP OKLAHOMA
AND PORTIONS OF SOUTHERN KANSAS CLOUDY AND COOL. TEMPS WILL BE IN
THE 70S WITH SOME AREAS POSSIBLY COOLER. THE LIFT ASSOCIATED WITH
THIS PV ANOMALY WILL ALSO KEEP PRECIPITATION CHANCES FOR SOUTHERN
KANSAS THROUGH FRIDAY AND SATURDAY. CONFIDENCE IS NOT HIGH ON HOW
EXPANSIVE THIS PRECIP WILL BE.
MONDAY - WEDNESDAY:
THE NEXT MAIN SHORTWAVE WILL KICK THE ENERGY EASTWARD THAT WILL
IMPACT THE REGION OVER THE WEEKEND. THIS WAVE WILL AGAIN PUSH A
FRONT THROUGH THE AREA WITH ADDITIONAL PRECIPITATION CHANCES FOR
EARLY NEXT WEEK. THIS FRONT IS NOT QUITE AS POTENT AND HAS MUCH
LESS MOISTURE TO WORK WITH THAN THE SYSTEM FOR TONIGHT/THURSDAY.
SHOWERS/THUNDERSTORMS ARE POSSIBLE...BUT CONFIDENCE IS LACKING ON
HOW WIDESPREAD THE RAIN WILL BE FOR THE AREA. TEMPERATURES FOR THE
NEXT WORKWEEK WILL BE IN THE 70S AND LOW 80S...SEASONAL FOR MID
SEPTEMBER.
BILLINGS
AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
FOCUS IS ON THE TIMING OF THE FRONT AND ASSOCIATED PRECIPITATION/
CEILINGS. THERE IS GOOD AGREEMENT IN SHORT RANGE MODELS FOR SOME
RAIN SHOWERS/THUNDERSTORMS TO BREAK OUT AHEAD OF THE FRONT FROM
MID LEVEL DECK...WHICH WILL BE CLOSE TO KHUT/KSLN AND LIKELY CATCH
KICT LATER THIS AFTERNOON. THE MAIN SHOW WILL OCCUR TONIGHT WITH
PRECIPITATION CHANCES INCREASING AT MOST SITES DURING THE NIGHT
AND LINGERING INTO THE MORNING. ANTICIPATE MVFR CEILINGS TO OCCUR
IN THE VICINITY OF MORE WIDESPREAD RAIN. VERY GUSTY NORTH WINDS
ARE EXPECTED JUST BEHIND THE FRONT. -HOWERTON
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 55 64 51 74 / 60 70 30 10
HUTCHINSON 54 62 46 74 / 90 80 10 10
NEWTON 55 64 48 73 / 70 80 20 10
ELDORADO 56 65 51 75 / 40 80 30 10
WINFIELD-KWLD 59 68 54 74 / 40 90 50 20
RUSSELL 53 69 43 75 / 100 50 10 10
GREAT BEND 53 66 44 73 / 100 70 10 10
SALINA 53 66 45 75 / 100 70 10 10
MCPHERSON 54 63 46 74 / 100 70 10 10
COFFEYVILLE 62 75 55 77 / 20 50 50 30
CHANUTE 61 69 54 75 / 20 70 40 20
IOLA 60 68 54 74 / 20 70 30 20
PARSONS-KPPF 62 72 55 76 / 20 50 50 30
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
945 PM EDT FRI SEP 14 2012
.SYNOPSIS...
DRY CONDITIONS AND SEASONABLE TEMPERATURES WILL CONTINUE AS HIGH
PRESSURE REMAINS ACROSS THE MID ATLANTIC THROUGH TONIGHT. A
WEAK COLD FRONT WILL TRACK ACROSS THE AREA SATURDAY MORNING. HIGH
PRESSURE WILL RETURN SUNDAY BEFORE UNSETTLED WEATHER EARLY NEXT
WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
OVERALL A PRETTY QUIET EVENING OVER SE VA. HAVE SOME MID TO HIGH
LEVEL CLOUDS FROM NE NC THROUGH THE WESTERN SHORE OF THE CHES BAY
AND UP THE DELMARVA. THESE CLOUDS WILL CONTINUE TO SLIDE EWD
TONIGHT AS A COLD FRONT APPROACHES FROM THE NE. THE COLD FRONT AT
1Z STRETCHES FROM NR IPT TO KW99 TO JKL. THE FRONT WILL CONTINUE
TO SLIDE SE...BUT AHEAD OF IT...THE SKY WILL REMAIN CLEAR AS THE
FRONT IS AN ANAFRONT. ONCE THE FRONT PASSES...WILL SEE SOME MID
LEVEL CLOUD COVER MOVING THROUGH. THE LIFT BEHIND THE FRONT IS
WEAK SO NOT ANTICIPATING ANY SHOWERS WITH THE FRONT. SO HAVE TWEAK
THE SKY COVER TO SHOW THE CLEARING EXPECTED AHEAD OF THE FRONT.
HAVE ALSO TWEAKED THE OVERNIGHT LOWS...GIVING THE TEMPS A LITTLE
BOOST DUE TO THE CURRENT DEWPOINT READINGS AND EXPECTATION OF SOME
CONTINUED SRLY FLOW IN ADVANCE OF THE FRONT. DO NOT EXPECT THE
COOLER CONDITIONS BEHIND THE FRONT TO ARRIVE UNTIL LATER ON
SATURDAY SO SHOULD NOT SEE A BIG TEMP DROP IMMEDIATELY BEHIND THE
FRONT DUE TO THE CLOUDS THAT WILL ARRIVE.
PREV DISCUSSION...
A TOUCH MORE HUMID ACRS THE FA THIS AFTN AS COMPARED TO PAST FEW.
SFC HI PRES CONTS TO WEAKEN THROUGH THE EVE HRS...WHILE CDFNT
APPROACHES FM THE NW. SO FAR...LTL MOVEMENT (N) NOTED ON SCT SHRAS
OVR ECNTRL NC THIS AFTN...17Z/14 RUC KEEPS THOSE SHRAS GENLY FM
ALBEMARLE SND ON S...OTRW XPCG CLR-PCLDY WX E...AND P/MCLDY W.
PCPN CURRENTLY ASSOCIATED W/ THE CDFNT HAS CONTD TO
DIMINISH...APRS THAT HIGHEST PROB FOR ANY SHRAS AND MOST
WIDESPREAD CLDNS WILL RMN NNW OF THE FA THROUGH TNGT. CDFNT TO
PRESS INTO THE CNTRL PORTION OF FA BY 12Z/15. WILL HAVE POPS AOB
14% OVR THE FA OVRNGT.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
CDFNT PRESSES S AND E OF THE FA DURG SAT MRNG...W/ ASSOCIATED
WINDSHIFT TO THE N AS SFC HI PRES BUILDS EWD INTO THE ERN LAKES
RGN. FM SAT NGT THROUGH SUN...S/W MOVG INTO THE LWR MS
VALLEY...AND IN COMBINATION W/ STALLED FNTL BNDRY ACRSS THE
CAROLINAS...THERE WILL BE INCRSD COVERAGE OF CLDNS AND RAINFALL
(FM THE SRN MTNS THROUGH THE TN VLY AND LWR MS VLY. BY SUN
AFTN/EVE...CLDNS AND PCPN MAY BRUSH FAR SSW AREAS OF FA...OTRW SFC
HI PRES RMNS OVR THE RGN...PROVIDING DRY/NR SEASONABLE CONDS.
HI PRES TO BECOME SITUATED OFF THE E CST SUN NGT THROUGH MON...W/
TROUGH ALOFT DIGGING THROUGH THE MIDWEST. AT THE SAME TIME...S/W
WILL BE MOVG E THROUGH THE LWR MS VLY/SE STATES. MDLS GENLY AGREE
W/ INCRSG LLVL/MOIST FLO INTO THE MDATLC STATES...ESP ON
MON...BRINGING A MDT/HI PROB FOR RAINFALL. HI CHCS FOR MON TO BE
CONFINED TO INTR SECTIONS OF FA.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MEDIUM RANGE PERIOD BEGINS WITH SOUTHERN STREAM SHORTWAVE TROUGH
LIFTING NORTHEAST OUT OF THE DEEP SOUTH TOWARDS THE REGION... JUST
AHEAD OF THE NRN STREAM TROUGH POISED TO MOVE ACROSS THE MOUNTAINS
THROUGH TUESDAY. THE MODELS CONTINUE TO HANDLE THE UPPER TROUGH
SIMILARLY, WITH LLVL S WINDS STREAMING MOISTURE-RICH GULF MOISTURE
INTO THE REGION MONDAY NIGHT AND TUESDAY. PROGGED PW AND OMEGA
FIELDS INDICATE THAT OVERRUNNING MOISTURE SHOULD BE STRONG ENOUGH
TO WARRANT 50-60 POP FOR MONDAY NIGHT AND TUESDAY. FRONT APPROACHES
THE REGION TUESDAY NIGHT, WITH THE FRONT LKLY TO CLEAR THE REGION
WEDNESDAY. LOW/MIDLVL FLOW BECOMES W/NW WITH RESULTANT DOWNSLOPE
FLOW SUFFICIENT TO BRING A DRY FORECAST FOR THE LATTER HALF OF THE
WEEK AHEAD.
FOR TEMPERATURES...EXPECT MAXIMA TO AVERAGE NEAR TO JUST BELOW CLIMO
NORMAL FOR THE PERIOD. HIGHS GENERALLY INTO THE 70S TO NR 80. LOWS
IN THE 60S TO NR 70 TUESDAY MORNING...FALLING BACK INTO THE 50S AND
60S TOWARDS THE MIDDLE OF NEXT WEEK, WITH SOME EARLY MORNING LOWS IN
THE UPPER 40S POSSIBLE TOWARDS LATE NEXT WEEK WEST OF RIC.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
A WEAK COLD FRONT TO MOVE THROUGH THE TAF SITES EARLY SATURDAY
MORNING. MOS FCSTS FOR SBY AGAIN FORECASTING IFR FOG BUT HAVE BEEN
WRONG THE LAST SEVERAL MORNINGS SO ONLY WENT MVFR THERE. PRE-
FRONTAL CONDITIONS DO NOT APPEAR AS FAVORABLE FOR PATCHY FOG
ELSEWHERE AS THEY WERE EARLY FRIDAY MORNING. CALM/LIGHT WINDS WILL
INCREASE TOWARD SUNRISE.
BEHIND THE FRONT...NORTHERLY WINDS BECOME GUSTY NEAR THE BAY AND
COASTAL AREAS AND INCLUDED GUSTS AT ORF AND ECG.
OUTLOOK...MAINLY VFR CONDS THROUGH SUNDAY NIGHT. NEXT CHC FOR PRECIP
/ LWR CIGS / VSBYS WILL BE MON INTO TUE NGT.
&&
.MARINE...
WEAK SFC RIDGING OVER THE NORTHEAST CONTINUES TO SAG INTO THE REGION
THIS AFTERNOON...PROVIDING ONSHORE (E-NE) FLOW ~10 KT, WHICH WILL
CONTINUE THROUGH TONIGHT. SEAS RUNNING 2-4FT NEAR SHORE (1-2FT
BAY/SND). A WEAK (DRY) COLD FRONT WILL PUSH ACRS THE AREA LATE
TONIGHT INTO SAT MORN. BRIEF PERIOD OF SCA EXPECTED OVER THE CHES
BAY SAT MORNING INTO THE AFTN AND SCA HAS BEEN HOISTED FOR SATURDAY
OVER THE CHES BAY AND RIVERS. WINDS DIMINISH WITH SLACKENING
GRADIENT SAT AFTN AND EVENING. HOWEVER, SEAS OVER WATERS LOOK TO
REMAIN IN 3-4 FT RANGE DUE TO INCOMING E-SE SWELL (15-20 SEC)
ARRIVING ALONG THE MID-ATLANTIC COAST BEGINNING SAT EVENING THROUGH
SUNDAY FROM DISTANT TROP STORM NADINE, WHICH IS ORIENTED WELL E/SE
OF BERMUDA. THESE SWELLS WILL ALSO LIKELY RESULT IN CONTINUED
ELEVATED RIP THREAT THROUGH THE WEEKEND.
N-NW WINDS CONTINUE TO DIMINISH SAT NIGHT/SUN AS SFC HIGH PRESSURE
SLIDES OVERHEAD. SFC RIDGE IS EXPECTED TO SLIDE OFF THE COAST LATER
SUN THRU MON. A WARM FRONT THEN LIFTS ACROSS THE AREA DURING MON/MON
NGT, WITH S-SE FLOW 15 KT OR LESS MON-TUE. TIGHTENING PRESSURE
GRADIENT WILL ALLOW FOR INCREASING S/SE FLOW BY THE MIDDLE OF NEXT
WEEK, WITH SCA LIKELY TO BE NEEDED IN ASSOCIATION W/NEXT FRONTAL
PASSAGE TUE/WED OF NEXT WEEK.
&&
.EQUIPMENT...
AT SBY...NORMAL ASOS COMMS REMAIN DOWN AND ARE EXPECTED TO STAY DOWN
FOR SEVERAL DAYS. OBS ARE BEING SENT BY THE TOWER BUT THESE UPDATES
MAY NOT BE RELIABLE SO AMD NOT SKED WILL CONTINUE TO APPEAR IN THE
TAFS.
COMMS WITH ORF ASOS HAVE BEEN RESTORED.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT SATURDAY FOR
ANZ630>632-634>638.
&&
$$
SYNOPSIS...ALB/SAM
NEAR TERM...ALB/ESS
SHORT TERM...ALB
LONG TERM...MAM
AVIATION...LSA
MARINE...MAM
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
819 PM EDT FRI SEP 14 2012
.SYNOPSIS...
DRY CONDITIONS AND SEASONABLE TEMPERATURES WILL CONTINUE AS HIGH
PRESSURE REMAINS ACROSS THE MID ATLANTIC THROUGH TONIGHT. A
WEAK COLD FRONT WILL TRACK ACROSS THE AREA SATURDAY MORNING. HIGH
PRESSURE WILL RETURN SUNDAY BEFORE UNSETTLED WEATHER EARLY NEXT
WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
A TOUCH MORE HUMID ACRS THE FA THIS AFTN AS COMPARED TO PAST FEW.
SFC HI PRES CONTS TO WEAKEN THROUGH THE EVE HRS...WHILE CDFNT
APPROACHES FM THE NW. SO FAR...LTL MOVEMENT (N) NOTED ON SCT SHRAS
OVR ECNTRL NC THIS AFTN...17Z/14 RUC KEEPS THOSE SHRAS GENLY FM
ALBEMARLE SND ON S...OTRW XPCG CLR-PCLDY WX E...AND P/MCLDY W.
PCPN CURRENTLY ASSOCIATED W/ THE CDFNT HAS CONTD TO
DIMINISH...APRS THAT HIGHEST PROB FOR ANY SHRAS AND MOST
WIDESPREAD CLDNS WILL RMN NNW OF THE FA THROUGH TNGT. CDFNT TO
PRESS INTO THE CNTRL PORTION OF FA BY 12Z/15. WILL HAVE POPS AOB
14% OVR THE FA OVRNGT.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
CDFNT PRESSES S AND E OF THE FA DURG SAT MRNG...W/ ASSOCIATED
WINDSHIFT TO THE N AS SFC HI PRES BUILDS EWD INTO THE ERN LAKES
RGN. FM SAT NGT THROUGH SUN...S/W MOVG INTO THE LWR MS
VALLEY...AND IN COMBINATION W/ STALLED FNTL BNDRY ACRSS THE
CAROLINAS...THERE WILL BE INCRSD COVERAGE OF CLDNS AND RAINFALL
(FM THE SRN MTNS THROUGH THE TN VLY AND LWR MS VLY. BY SUN
AFTN/EVE...CLDNS AND PCPN MAY BRUSH FAR SSW AREAS OF FA...OTRW SFC
HI PRES RMNS OVR THE RGN...PROVIDING DRY/NR SEASONABLE CONDS.
HI PRES TO BECOME SITUATED OFF THE E CST SUN NGT THROUGH MON...W/
TROUGH ALOFT DIGGING THROUGH THE MIDWEST. AT THE SAME TIME...S/W
WILL BE MOVG E THROUGH THE LWR MS VLY/SE STATES. MDLS GENLY AGREE
W/ INCRSG LLVL/MOIST FLO INTO THE MDATLC STATES...ESP ON
MON...BRINGING A MDT/HI PROB FOR RAINFALL. HI CHCS FOR MON TO BE
CONFINED TO INTR SECTIONS OF FA.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MEDIUM RANGE PERIOD BEGINS WITH SOUTHERN STREAM SHORTWAVE TROUGH
LIFTING NORTHEAST OUT OF THE DEEP SOUTH TOWARDS THE REGION... JUST
AHEAD OF THE NRN STREAM TROUGH POISED TO MOVE ACROSS THE MOUNTAINS
THROUGH TUESDAY. THE MODELS CONTINUE TO HANDLE THE UPPER TROUGH
SIMILARLY, WITH LLVL S WINDS STREAMING MOISTURE-RICH GULF MOISTURE
INTO THE REGION MONDAY NIGHT AND TUESDAY. PROGGED PW AND OMEGA
FIELDS INDICATE THAT OVERRUNNING MOISTURE SHOULD BE STRONG ENOUGH
TO WARRANT 50-60 POP FOR MONDAY NIGHT AND TUESDAY. FRONT APPROACHES
THE REGION TUESDAY NIGHT, WITH THE FRONT LKLY TO CLEAR THE REGION
WEDNESDAY. LOW/MIDLVL FLOW BECOMES W/NW WITH RESULTANT DOWNSLOPE
FLOW SUFFICIENT TO BRING A DRY FORECAST FOR THE LATTER HALF OF THE
WEEK AHEAD.
FOR TEMPERATURES...EXPECT MAXIMA TO AVERAGE NEAR TO JUST BELOW CLIMO
NORMAL FOR THE PERIOD. HIGHS GENERALLY INTO THE 70S TO NR 80. LOWS
IN THE 60S TO NR 70 TUESDAY MORNING...FALLING BACK INTO THE 50S AND
60S TOWARDS THE MIDDLE OF NEXT WEEK, WITH SOME EARLY MORNING LOWS IN
THE UPPER 40S POSSIBLE TOWARDS LATE NEXT WEEK WEST OF RIC.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
A WEAK COLD FRONT TO MOVE THROUGH THE TAF SITES EARLY SATURDAY
MORNING. MOS FCSTS FOR SBY AGAIN FORECASTING IFR FOG BUT HAVE BEEN
WRONG THE LAST SEVERAL MORNINGS SO ONLY WENT MVFR THERE. PRE-
FRONTAL CONDITIONS DO NOT APPEAR AS FAVORABLE FOR PATCHY FOG
ELSEWHERE AS THEY WERE EARLY FRIDAY MORNING. CALM/LIGHT WINDS WILL
INCREASE TOWARD SUNRISE.
BEHIND THE FRONT...NORTHERLY WINDS BECOME GUSTY NEAR THE BAY AND
COASTAL AREAS AND INCLUDED GUSTS AT ORF AND ECG.
OUTLOOK...MAINLY VFR CONDS THROUGH SUNDAY NIGHT. NEXT CHC FOR PRECIP
/ LWR CIGS / VSBYS WILL BE MON INTO TUE NGT.
&&
.MARINE...
WEAK SFC RIDGING OVER THE NORTHEAST CONTINUES TO SAG INTO THE REGION
THIS AFTERNOON...PROVIDING ONSHORE (E-NE) FLOW ~10 KT, WHICH WILL
CONTINUE THROUGH TONIGHT. SEAS RUNNING 2-4FT NEAR SHORE (1-2FT
BAY/SND). A WEAK (DRY) COLD FRONT WILL PUSH ACRS THE AREA LATE
TONIGHT INTO SAT MORN. BRIEF PERIOD OF SCA EXPECTED OVER THE CHES
BAY SAT MORNING INTO THE AFTN AND SCA HAS BEEN HOISTED FOR SATURDAY
OVER THE CHES BAY AND RIVERS. WINDS DIMINISH WITH SLACKENING
GRADIENT SAT AFTN AND EVENING. HOWEVER, SEAS OVER WATERS LOOK TO
REMAIN IN 3-4 FT RANGE DUE TO INCOMING E-SE SWELL (15-20 SEC)
ARRIVING ALONG THE MID-ATLANTIC COAST BEGINNING SAT EVENING THROUGH
SUNDAY FROM DISTANT TROP STORM NADINE, WHICH IS ORIENTED WELL E/SE
OF BERMUDA. THESE SWELLS WILL ALSO LIKELY RESULT IN CONTINUED
ELEVATED RIP THREAT THROUGH THE WEEKEND.
N-NW WINDS CONTINUE TO DIMINISH SAT NIGHT/SUN AS SFC HIGH PRESSURE
SLIDES OVERHEAD. SFC RIDGE IS EXPECTED TO SLIDE OFF THE COAST LATER
SUN THRU MON. A WARM FRONT THEN LIFTS ACROSS THE AREA DURING MON/MON
NGT, WITH S-SE FLOW 15 KT OR LESS MON-TUE. TIGHTENING PRESSURE
GRADIENT WILL ALLOW FOR INCREASING S/SE FLOW BY THE MIDDLE OF NEXT
WEEK, WITH SCA LIKELY TO BE NEEDED IN ASSOCIATION W/NEXT FRONTAL
PASSAGE TUE/WED OF NEXT WEEK.
&&
.EQUIPMENT...
AT SBY...NORMAL ASOS COMMS REMAIN DOWN AND ARE EXPECTED TO STAY DOWN
FOR SEVERAL DAYS. OBS ARE BEING SENT BY THE TOWER BUT THESE UPDATES
MAY NOT BE RELIABLE SO AMD NOT SKED WILL CONTINUE TO APPEAR IN THE
TAFS.
COMMS WITH ORF ASOS HAVE BEEN RESTORED.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT SATURDAY FOR
ANZ630>632-634>638.
&&
$$
SYNOPSIS...ALB/SAM
NEAR TERM...ALB
SHORT TERM...ALB
LONG TERM...MAM
AVIATION...LSA
MARINE...MAM
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
728 PM EDT FRI SEP 14 2012
.SYNOPSIS...
SHOWERS WILL COME TO AN END THIS EVENING AS A COLD FRONT PUSHES
EAST OF THE AREA. DRY AND COOL CONDITIONS WILL FOLLOW WITH HIGH
PRESSURE BUILDING OVER THE AREA FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH SATURDAY/...
21Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO ACCOUNT
FOR THE LATEST COLD FRONT POSITION AS IT CROSSES OUR AREA.
RADAR, OBS, AND SAT IMAGERY INDICATE THAT A COLD FRONT HAS PUSHED
EAST OF THE PITTSBURGH METRO AND CURRENTLY EXTENDS ALONG A LINE FROM
DUBOIS TO WASHINGTON TO NEW MARTINSVILLE. SHOWERS HAVE BEEN
LIMITED ALONG THE FRONT, WITH THE MORE MOISTURE STARVED PRE-
FRONTAL ENVIRONMENT SOUTH OF PITTSBURGH LIMITING COVERAGE TO JUST
ISOLATED SHOWERS. NORTHWARD OF KPIT, SHOWERS ARE MORE NUMEROUS
WITH BETTER FORCING FROM 500MB POSITIVE VORTICITY ADVECTION AS A
VORT LOBE PASS FROM NE OHIO INTO WESTERN PA. A NOTICEABLE 5-10
DEGREE DECREASE IN TEMPERATURES ALONG WITH A SOUTHWEST TO
NORTHWEST WIND SHIFT WITH THE FRONTAL PASSAGE.
TONIGHT...RADAR TRENDS ALONG WITH THE HRRR SUPPORT THE FRONT
PUSHING EAST OF THE RIDGES BY 00Z WITH ANY LINGERING SHOWERS
COMING TO AN END BY 03Z. BEHIND THE FRONTAL BAND OF MOISTURE,
DRIER AIR IN THE 900-250MB LAYER WILL ADVECT INTO THE AREA AND
ALLOW FOR CLEARING SKIES ACROSS THE AREA BY DAWN. HIGH PRESSURE WILL
THEN BEGIN TO BUILD IN FROM THE WEST AND BECOME CENTERED ACROSS
IN/OH BY DAWN. DESPITE CLEARING SKIES, LOOSENING PRESSURE GRADIENT
WILL STILL BE ENOUGH FOR 5-10KT WINDS WHICH WILL PREVENT THE
DEVELOPMENT OF FOG NEAR DAWN. TEMPS WILL STEADILY DROP OFF IN
COLD AIR ADVECTION OVERNIGHT WITH LOWS NEAR LAMP GUIDANCE, RANGING
FROM THE UPPER 40S TO THE LOWER 50S ACROSS THE AREA.
SATURDAY...DESPITE RELATIVELY LOW CONVECTIVE TEMPS UNDR NW FLOW
ALOFT...LOW INVERSION LEVELS SHOULD PRECLUDE ANY SHRA ON
SATURDAY...ALTHOUGH CU/SC FIELD IS ANTICIPATED. TEMPS WERE
FORECAST USING NAM NMBRS.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
DRY WX WL CONT THROUGH SUNDAY WITH BUILDING HIGH PRES. BY
MONDAY...SHRTWV MOVG THRU THE BASE OF ADVNG LONGWAVE TROF IS
FORECAST TO PULL MSTR NWD ALNG THE APPALACHIANS. AS THE SYSTEM IS
STILL PROJECTED AS AN OPEN MID LVL WAVE...WWD EXTENT OF THE RESULTING
PCPN IS QNABLE...AND LIKELY P0PS IN THE LATE DAY WERE CONFINED TO
THE RIDGES FOR NOW.
SHORT TERM TEMPS WERE FORECAST ABOUT 5 DEGREES UNDR THE AVERAGES
USING TWEAKED NAM GUIDANCE.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MODELS HAVE COME TO A MUCH BETTER CONSENSUS ON THE OVERALL
PROGRESSION OF THE LONGWAVE TROUGH AND THE EMBEDDED WAVE OUT AHEAD
OF IT THROUGH THE FIRST HALF OF THE PERIOD. THE ECMWF HAS FINALLY
COME ON BOARD WITH THE GFS WITH A BIT MORE AMPLIFIED SYSTEM MOVING
ALONG THE APPALACHIANS BRINGING PRECIPITATION NORTHWARD MONDAY
NIGHT. THE DIFFERENCE COMES IN TIMING OF THE COLD FRONT WITH
THE ECMWF ONLY SLIGHTLY SLOWER. WILL INTRODUCE LIKELY POPS STARTING
MONDAY NIGHT THROUGH MUCH OF TUESDAY WITH BETTER MODEL
AGREEMENT.
NORTHWEST FLOW AND WHAT APPEARS TO BE THE COOLEST TEMPERATURES ALOFT
SO FAR THIS SEASON WILL KEEP TEMPERATURES WELL BELOW NORMAL
WEDNESDAY. THE DETERMINISTIC MODELS MAINTAIN A LONGWAVE TROUGH WITH
EMBEDDED WAVES IN THE FLOW THURSDAY AND FRIDAY WHICH COULD BRING
ROUNDS OF PRECIPITATION AND NEAR NORMAL TEMPERATURES FOR THE
REMAINDER OF THE WEEK.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
THE COLD FRONT HAS PUSHED EAST OF ALL PORTS AND SCATTERED RAIN
SHOWERS PERSIST BEHIND THE FRONT FOR SEVERAL HOURS. SHOWERS WILL
END FROM WEST TO EAST BEFORE MIDNIGHT. A PERIOD OF LOWER
IFR/MVFR CEILINGS CAN BE EXPECTED FOR SEVERAL HOURS BEHIND THE
COLD FRONT. NORTHWEST WIND GUSTS OF 25 TO 30 KNOTS CAN BE
EXPECTED IMMEDIATELY BEHIND THE COLD FRONT WITH DIMINISHING WINDS
INTO MIDNIGHT.
HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT SKIES BRINGING CLEARING
SKIES BY EARLY MORNING. SOME PATCHY MORNING FOG IS POSSIBLE IN
THE RIVER VALLEYS SATURDAY MORNING BUT IF WINDS REMAIN ABOVE 5 TO
10 KNOTS FOG WILL BE UNLIKELY.
.OUTLOOK /SATURDAY THROUGH TUESDAY/...
VFR CONDITIONS ARE EXPECTED UNDER HIGH PRESSURE SATURDAY THROUGH THE
FIRST HALF OF MONDAY. THE NEXT CHANCE FOR SHOWERS AND RESTRICTIONS
WILL BE WITH THE APPROACH OF A LOW PRESSURE SYSTEM AND COLD FRONT
MONDAY NIGHT AND TUESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
427 PM EDT THU SEP 13 2012
.SYNOPSIS...
ISSUED AT 427 PM EDT THU SEP 13 2012
A COLD FRONT WILL BRING RAIN TO THE AREA OVERNIGHT. THIS WILL BE
FOLLOWED BY COOLER BUT STILL SEASONABLE TEMPERATURES AROUND 70 ON
FRIDAY. AFTER A GRADUAL WARMING TREND TO THE MID 70S THROUGH
MONDAY...ANOTHER COLD FRONT WILL BRING A CHANCE FOR RAIN SHOWERS
MONDAY NIGHT AND TUESDAY ALONG WITH HIGH TEMPERATURES IN THE 60S.
&&
.UPDATE...
ISSUED AT 424 PM EDT THU SEP 13 2012
FORECAST WAS UPDATED TO ACCOUNT FOR THE SHOWERS DEVELOPING FROM
LANSING TO NEAR KALAMAZOO.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 335 PM EDT THU SEP 13 2012
TREND ON THE RAIN FOR TONIGHT HAS BEEN DOWN IN TERMS OF AMOUNTS FOR
SEVERAL MODEL RUNS NOW. REGIONAL RADAR LOOPS DO NOT LOOK OVERLY
IMPRESSIVE EITHER. STILL...EXPECT A BAND OF RAIN TO WORK THROUGH THE
ENTIRE FORECAST AREA BRINGING AMOUNTS ON THE ORDER OF A TENTH OR TWO
AT MOST LOCATIONS. THE FAR SOUTHEAST TOWARD JACKSON MAY SEE SLIGHTLY
HIGHER AMOUNTS. PRECIPITATION IS BEING FOCUSED BY THE RIGHT ENTRANCE
REGION OF A 300MB JET. CURRENT THINKING BASED ON SPC AND NSSL WRF
MODEL RUNS AND THE TRENDS IN THE LATEST HRRR IS THAT THE RAIN WILL
BE OFF TO THE EAST OF THE FORECAST AREA BY 12Z ON FRIDAY.
LOOKING FOR SOME MORNING CUMULUS DEVELOPMENT ON FRIDAY WITH DRIER
AIR TAKING OVER DURING THE AFTERNOON. IN GENERAL EXPECTING A PARTLY
CLOUDY TO MOSTLY SUNNY FORECAST FOR FRIDAY. FEEL THE AIR MASS
WILL BE TOO DRY FOR ANY SHOWER DEVELOPMENT OFF THE LAKE DESPITE
DELTA T/S IN THE MIDDLE TEENS C.
FRIDAY NIGHT THROUGH SATURDAY NIGHT LOOKS QUIET AND DRY WITH HIGH
PRESSURE IN CONTROL.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 335 PM EDT THU SEP 13 2012
FAIR WX WITH SEASONABLY MILD TEMPS IS ANTICIPATED SUNDAY THROUGH
MONDAY AFTERNOON IN A SOUTHERLY FLOW WAA PATTERN IN ADVANCE OF THE
APPROACHING COLD FRONT. THAT FRONT WILL BRING SOME SHOWERS MONDAY
NIGHT THROUGH TUESDAY. LAKE EFFECT CLOUDS AND SHOWERS ARE
ANTICIPATED TUESDAY NIGHT INTO WEDNESDAY AS H8 TEMPS (BRIEFLY) DIP
DOWN TO AROUND 0 TO -1 C BEFORE MODERATING.
IT WILL TURN COOLER TUESDAY THROUGH MIDWEEK AS A FAIRLY DEEP
LONGWAVE UPPER LEVEL TROUGH DEVELOPS FROM THE UPPER MIDWEST TO GREAT
LAKES REGIONS. A SECONDARY COLD FRONT WILL BRING THE CHANCE FOR
ADDITIONAL SHOWERS WEDNESDAY NIGHT THROUGH THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY)
ISSUED AT 1200 PM EDT THU SEP 13 2012
VFR CONDITIONS THIS AFTERNOON WILL GRADUALLY TRANSITION TO MVFR
TONIGHT AS LOW CLOUDS AND A BAND OF SHOWERS GRADUALLY MOVE IN FROM
THE WEST. SHOWERS SHOULD REACH KMKG BY LATE AFTN AND THE REST OF THE
TERMINALS THIS EVENING. CONDITIONS WILL GRADUALLY IMPROVE BACK TO
VFR FRIDAY MORNING AS THE LOWER CLOUDS AND SHOWERS EXIT THE AREA. NW
WINDS WILL RAMP UP TO 10-15 KTS BY LATE FRIDAY MORNING AS CLOUDS
SCATTER OUT BEFORE SKIES EVENTUALLY CLEAR.
&&
.MARINE...
ISSUED AT 335 PM EDT THU SEP 13 2012
HAVE OPTED TO KEEP THE CURRENT CONFIGURATION TO THE SMALL CRAFT
ADVISORIES WITH THE NORTH ENDING THIS EVENING AND THE SOUTH
OVERNIGHT. GRADIENT TURNS LAX TONIGHT IN THE WAKE OF FIRST FRONTAL
PASSAGE WHICH LEADS TO A DECAYING WAVE FIELD. WINDS INCREASE AGAIN
ON FRIDAY THOUGH IN THE WAKE OF A SECONDARY FRONT LATE TONIGHT.
WINDS WILL LIKELY NOSE UP TOWARDS 20 KNOTS FRIDAY WHICH SHOULD BUILD
A SOLID 3-5 FOOT WAVE FIELD DURING THE DAY. SO...RATHER THAN STRETCH
THE CURRENT SCA THROUGH TOMORROW THROUGH A 8-12 PERIOD OF QUIET
WAVES LATE TONIGHT AND TOMORROW MORNING OPTED TO LET THE CURRENT
HEADLINES EXPIRE TONIGHT. A NEW SCA WILL LIKELY BE NEED FOR FRIDAY
WITH THE OVERNIGHT FORECAST PACKAGE IF THE CURRENT FORECAST WINDS
HOLD.
&&
.HYDROLOGY...
ISSUED AT 335 PM EDT THU SEP 13 2012
NO HYDRO ISSUES ANTICIPATED WITH RAINFALL AMOUNTS PROBABLY ENDING UP
BELOW A THIRD OF AN INCH IN MANY AREAS TONIGHT. HIGHEST AMOUNTS WILL
BE IN THE FAR SOUTHEAST REACHES OF THE FORECAST AREA TOWARDS
JACKSON. RIVER LEVELS ARE LOW AND WELL WITHIN BANK. THE NEXT CHANCE
FOR RAIN DOES NOT COME UNTIL EARLY NEXT WEEK AFTER TONIGHT.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LMZ847>849.
SMALL CRAFT ADVISORY UNTIL 4 AM EDT FRIDAY FOR LMZ844>846.
&&
$$
UPDATE...MJS
SYNOPSIS...TJT
SHORT TERM...DUKE
LONG TERM...LAURENS
AVIATION...LAURENS
HYDROLOGY...DUKE
MARINE...DUKE
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
425 PM EDT THU SEP 13 2012
.SYNOPSIS...
ISSUED AT 335 PM EDT THU SEP 13 2012
A COLD FRONT WILL MOVE SOUTH OF THE STATE OF MICHIGAN TONIGHT
USHERING IN A COOLER AIR MASS. HIGHS FRIDAY...SATURDAY AND SUNDAY
WILL WARM A BIT EACH DAY WITH FRIDAY HIGHS ONLY AROUND 70...SATURDAY
IN THE LOWER 70S AND SUNDAY PUSHING INTO THE MIDDLE 70S. THE WEEKEND
IS EXPECTED TO BE DRY WITH A GOOD DEAL OF SUNSHINE. A BAND OF RAIN
WILL MOVE THROUGH THE AREA THIS EVENING AND OVERNIGHT. IT SHOULD BE
EAST OF LANSING AND JACKSON BY ABOUT SUNRISE ON FRIDAY.
&&
.UPDATE...
ISSUED AT 424 PM EDT THU SEP 13 2012
FORECAST WAS UPDATED TO ACCOUNT FOR THE SHOWERS DEVELOPING FROM
LANSING TO NEAR KALAMAZOO.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 335 PM EDT THU SEP 13 2012
TREND ON THE RAIN FOR TONIGHT HAS BEEN DOWN IN TERMS OF AMOUNTS FOR
SEVERAL MODEL RUNS NOW. REGIONAL RADAR LOOPS DO NOT LOOK OVERLY
IMPRESSIVE EITHER. STILL...EXPECT A BAND OF RAIN TO WORK THROUGH THE
ENTIRE FORECAST AREA BRINGING AMOUNTS ON THE ORDER OF A TENTH OR TWO
AT MOST LOCATIONS. THE FAR SOUTHEAST TOWARD JACKSON MAY SEE SLIGHTLY
HIGHER AMOUNTS. PRECIPITATION IS BEING FOCUSED BY THE RIGHT ENTRANCE
REGION OF A 300MB JET. CURRENT THINKING BASED ON SPC AND NSSL WRF
MODEL RUNS AND THE TRENDS IN THE LATEST HRRR IS THAT THE RAIN WILL
BE OFF TO THE EAST OF THE FORECAST AREA BY 12Z ON FRIDAY.
LOOKING FOR SOME MORNING CUMULUS DEVELOPMENT ON FRIDAY WITH DRIER
AIR TAKING OVER DURING THE AFTERNOON. IN GENERAL EXPECTING A PARTLY
CLOUDY TO MOSTLY SUNNY FORECAST FOR FRIDAY. FEEL THE AIR MASS
WILL BE TOO DRY FOR ANY SHOWER DEVELOPMENT OFF THE LAKE DESPITE
DELTA T/S IN THE MIDDLE TEENS C.
FRIDAY NIGHT THROUGH SATURDAY NIGHT LOOKS QUIET AND DRY WITH HIGH
PRESSURE IN CONTROL.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 335 PM EDT THU SEP 13 2012
FAIR WX WITH SEASONABLY MILD TEMPS IS ANTICIPATED SUNDAY THROUGH
MONDAY AFTERNOON IN A SOUTHERLY FLOW WAA PATTERN IN ADVANCE OF THE
APPROACHING COLD FRONT. THAT FRONT WILL BRING SOME SHOWERS MONDAY
NIGHT THROUGH TUESDAY. LAKE EFFECT CLOUDS AND SHOWERS ARE
ANTICIPATED TUESDAY NIGHT INTO WEDNESDAY AS H8 TEMPS (BRIEFLY) DIP
DOWN TO AROUND 0 TO -1 C BEFORE MODERATING.
IT WILL TURN COOLER TUESDAY THROUGH MIDWEEK AS A FAIRLY DEEP
LONGWAVE UPPER LEVEL TROUGH DEVELOPS FROM THE UPPER MIDWEST TO GREAT
LAKES REGIONS. A SECONDARY COLD FRONT WILL BRING THE CHANCE FOR
ADDITIONAL SHOWERS WEDNESDAY NIGHT THROUGH THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY)
ISSUED AT 1200 PM EDT THU SEP 13 2012
VFR CONDITIONS THIS AFTERNOON WILL GRADUALLY TRANSITION TO MVFR
TONIGHT AS LOW CLOUDS AND A BAND OF SHOWERS GRADUALLY MOVE IN FROM
THE WEST. SHOWERS SHOULD REACH KMKG BY LATE AFTN AND THE REST OF THE
TERMINALS THIS EVENING. CONDITIONS WILL GRADUALLY IMPROVE BACK TO
VFR FRIDAY MORNING AS THE LOWER CLOUDS AND SHOWERS EXIT THE AREA. NW
WINDS WILL RAMP UP TO 10-15 KTS BY LATE FRIDAY MORNING AS CLOUDS
SCATTER OUT BEFORE SKIES EVENTUALLY CLEAR.
&&
.MARINE...
ISSUED AT 335 PM EDT THU SEP 13 2012
HAVE OPTED TO KEEP THE CURRENT CONFIGURATION TO THE SMALL CRAFT
ADVISORIES WITH THE NORTH ENDING THIS EVENING AND THE SOUTH
OVERNIGHT. GRADIENT TURNS LAX TONIGHT IN THE WAKE OF FIRST FRONTAL
PASSAGE WHICH LEADS TO A DECAYING WAVE FIELD. WINDS INCREASE AGAIN
ON FRIDAY THOUGH IN THE WAKE OF A SECONDARY FRONT LATE TONIGHT.
WINDS WILL LIKELY NOSE UP TOWARDS 20 KNOTS FRIDAY WHICH SHOULD BUILD
A SOLID 3-5 FOOT WAVE FIELD DURING THE DAY. SO...RATHER THAN STRETCH
THE CURRENT SCA THROUGH TOMORROW THROUGH A 8-12 PERIOD OF QUIET
WAVES LATE TONIGHT AND TOMORROW MORNING OPTED TO LET THE CURRENT
HEADLINES EXPIRE TONIGHT. A NEW SCA WILL LIKELY BE NEED FOR FRIDAY
WITH THE OVERNIGHT FORECAST PACKAGE IF THE CURRENT FORECAST WINDS
HOLD.
&&
.HYDROLOGY...
ISSUED AT 335 PM EDT THU SEP 13 2012
NO HYDRO ISSUES ANTICIPATED WITH RAINFALL AMOUNTS PROBABLY ENDING UP
BELOW A THIRD OF AN INCH IN MANY AREAS TONIGHT. HIGHEST AMOUNTS WILL
BE IN THE FAR SOUTHEAST REACHES OF THE FORECAST AREA TOWARDS
JACKSON. RIVER LEVELS ARE LOW AND WELL WITHIN BANK. THE NEXT CHANCE
FOR RAIN DOES NOT COME UNTIL EARLY NEXT WEEK AFTER TONIGHT.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LMZ847>849.
SMALL CRAFT ADVISORY UNTIL 4 AM EDT FRIDAY FOR LMZ844>846.
&&
$$
UPDATE...MJS
SYNOPSIS...DUKE
SHORT TERM...DUKE
LONG TERM...LAURENS
AVIATION...LAURENS
HYDROLOGY...DUKE
MARINE...DUKE
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
335 PM EDT THU SEP 13 2012
.SYNOPSIS...
ISSUED AT 335 PM EDT THU SEP 13 2012
A COLD FRONT WILL MOVE SOUTH OF THE STATE OF MICHIGAN TONIGHT
USHERING IN A COOLER AIR MASS. HIGHS FRIDAY...SATURDAY AND SUNDAY
WILL WARM A BIT EACH DAY WITH FRIDAY HIGHS ONLY AROUND 70...SATURDAY
IN THE LOWER 70S AND SUNDAY PUSHING INTO THE MIDDLE 70S. THE WEEKEND
IS EXPECTED TO BE DRY WITH A GOOD DEAL OF SUNSHINE. A BAND OF RAIN
WILL MOVE THROUGH THE AREA THIS EVENING AND OVERNIGHT. IT SHOULD BE
EAST OF LANSING AND JACKSON BY ABOUT SUNRISE ON FRIDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 335 PM EDT THU SEP 13 2012
TREND ON THE RAIN FOR TONIGHT HAS BEEN DOWN IN TERMS OF AMOUNTS FOR
SEVERAL MODEL RUNS NOW. REGIONAL RADAR LOOPS DO NOT LOOK OVERLY
IMPRESSIVE EITHER. STILL...EXPECT A BAND OF RAIN TO WORK THROUGH THE
ENTIRE FORECAST AREA BRINGING AMOUNTS ON THE ORDER OF A TENTH OR TWO
AT MOST LOCATIONS. THE FAR SOUTHEAST TOWARD JACKSON MAY SEE SLIGHTLY
HIGHER AMOUNTS. PRECIPITATION IS BEING FOCUSED BY THE RIGHT ENTRANCE
REGION OF A 300MB JET. CURRENT THINKING BASED ON SPC AND NSSL WRF
MODEL RUNS AND THE TRENDS IN THE LATEST HRRR IS THAT THE RAIN WILL
BE OFF TO THE EAST OF THE FORECAST AREA BY 12Z ON FRIDAY.
LOOKING FOR SOME MORNING CUMULUS DEVELOPMENT ON FRIDAY WITH DRIER
AIR TAKING OVER DURING THE AFTERNOON. IN GENERAL EXPECTING A PARTLY
CLOUDY TO MOSTLY SUNNY FORECAST FOR FRIDAY. FEEL THE AIR MASS
WILL BE TOO DRY FOR ANY SHOWER DEVELOPMENT OFF THE LAKE DESPITE
DELTA T/S IN THE MIDDLE TEENS C.
FRIDAY NIGHT THROUGH SATURDAY NIGHT LOOKS QUIET AND DRY WITH HIGH
PRESSURE IN CONTROL.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 335 PM EDT THU SEP 13 2012
FAIR WX WITH SEASONABLY MILD TEMPS IS ANTICIPATED SUNDAY THROUGH
MONDAY AFTERNOON IN A SOUTHERLY FLOW WAA PATTERN IN ADVANCE OF THE
APPROACHING COLD FRONT. THAT FRONT WILL BRING SOME SHOWERS MONDAY
NIGHT THROUGH TUESDAY. LAKE EFFECT CLOUDS AND SHOWERS ARE
ANTICIPATED TUESDAY NIGHT INTO WEDNESDAY AS H8 TEMPS (BRIEFLY) DIP
DOWN TO AROUND 0 TO -1 C BEFORE MODERATING.
IT WILL TURN COOLER TUESDAY THROUGH MIDWEEK AS A FAIRLY DEEP
LONGWAVE UPPER LEVEL TROUGH DEVELOPS FROM THE UPPER MIDWEST TO GREAT
LAKES REGIONS. A SECONDARY COLD FRONT WILL BRING THE CHANCE FOR
ADDITIONAL SHOWERS WEDNESDAY NIGHT THROUGH THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY)
ISSUED AT 1200 PM EDT THU SEP 13 2012
VFR CONDITIONS THIS AFTERNOON WILL GRADUALLY TRANSITION TO MVFR
TONIGHT AS LOW CLOUDS AND A BAND OF SHOWERS GRADUALLY MOVE IN FROM
THE WEST. SHOWERS SHOULD REACH KMKG BY LATE AFTN AND THE REST OF THE
TERMINALS THIS EVENING. CONDITIONS WILL GRADUALLY IMPROVE BACK TO
VFR FRIDAY MORNING AS THE LOWER CLOUDS AND SHOWERS EXIT THE AREA. NW
WINDS WILL RAMP UP TO 10-15 KTS BY LATE FRIDAY MORNING AS CLOUDS
SCATTER OUT BEFORE SKIES EVENTUALLY CLEAR.
&&
.MARINE...
ISSUED AT 335 PM EDT THU SEP 13 2012
HAVE OPTED TO KEEP THE CURRENT CONFIGURATION TO THE SMALL CRAFT
ADVISORIES WITH THE NORTH ENDING THIS EVENING AND THE SOUTH
OVERNIGHT. GRADIENT TURNS LAX TONIGHT IN THE WAKE OF FIRST FRONTAL
PASSAGE WHICH LEADS TO A DECAYING WAVE FIELD. WINDS INCREASE AGAIN
ON FRIDAY THOUGH IN THE WAKE OF A SECONDARY FRONT LATE TONIGHT.
WINDS WILL LIKELY NOSE UP TOWARDS 20 KNOTS FRIDAY WHICH SHOULD BUILD
A SOLID 3-5 FOOT WAVE FIELD DURING THE DAY. SO...RATHER THAN STRETCH
THE CURRENT SCA THROUGH TOMORROW THROUGH A 8-12 PERIOD OF QUIET
WAVES LATE TONIGHT AND TOMORROW MORNING OPTED TO LET THE CURRENT
HEADLINES EXPIRE TONIGHT. A NEW SCA WILL LIKELY BE NEED FOR FRIDAY
WITH THE OVERNIGHT FORECAST PACKAGE IF THE CURRENT FORECAST WINDS
HOLD.
&&
.HYDROLOGY...
ISSUED AT 335 PM EDT THU SEP 13 2012
NO HYDRO ISSUES ANTICIPATED WITH RAINFALL AMOUNTS PROBABLY ENDING UP
BELOW A THIRD OF AN INCH IN MANY AREAS TONIGHT. HIGHEST AMOUNTS WILL
BE IN THE FAR SOUTHEAST REACHES OF THE FORECAST AREA TOWARDS
JACKSON. RIVER LEVELS ARE LOW AND WELL WITHIN BANK. THE NEXT CHANCE
FOR RAIN DOES NOT COME UNTIL EARLY NEXT WEEK AFTER TONIGHT.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR
LMZ847>849.
SMALL CRAFT ADVISORY UNTIL 4 AM EDT FRIDAY FOR LMZ844>846.
&&
$$
SYNOPSIS...DUKE
SHORT TERM...DUKE
LONG TERM...LAURENS
AVIATION...LAURENS
HYDROLOGY...DUKE
MARINE...DUKE
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1200 PM EDT THU SEP 13 2012
.SYNOPSIS...
ISSUED AT 340 AM EDT THU SEP 13 2012
CLOUDS WILL INCREASE THIS MORNING AND SHOWERS WILL GRADUALLY
BECOME MORE COMMONPLACE INTO THE AFTERNOON AND EVENING. THE RAIN
IS EXPECTED TO END FROM NORTHWEST TO SOUTHEAST LATER TONIGHT. HIGH
PRESSURE WILL RETURN FOR THE WEEKEND BRINGING SUNSHINE AND
TEMPERATURES IN THE UPPER 60S TO MID 70S.
&&
.UPDATE...
ISSUED AT 1058 AM EDT THU SEP 13 2012
TOUCHED UP THE FORECAST FROM THIS AFTERNOON THROUGH TONIGHT IN
TERMS OF POPS AND WEATHER. FOLLOWED THE LEAD OF BOTH THE HRRR AND
THE NSSL 4KM WRF MODELS WHICH BRING A BAND OF RAIN THROUGH THE
FORECAST AREA LATE THIS AFTERNOON THROUGH TONIGHT. MAIN CHANGE WAS
TO BACK OFF ON THE ARRIVAL TIME A BIT. THROUGH THIS
AFTERNOON AND EARLY EVENING...THE FAR NORTHWEST CWA NORTH OF MUSKEGON
AND BIG RAPIDS SHOULD BE THE MAIN AREA THAT IS AFFECTED BY RAIN.
IT WILL TAKE MORE INTO THE EVENING AND AFTER DARK TO AFFECT AREAS
LIKE GRAND RAPIDS. TEMPERATURES WILL BE HELD DOWN BY THE CLOUDS
MOVING INTO THE FAR NORTHWEST FORECAST AREA. TOWARD JXN HOWEVER
READINGS WILL LIKELY PUSH AT LEAST TO AROUND 80...IF NOT ECLIPSING
IT SLIGHTLY.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 340 AM EDT THU SEP 13 2012
A BAND OF RAIN WAS MOVING ACROSS WISCONSIN THIS MORNING AND SHOULD
REACH THE NW CORNER OF THE CWA NEAR LDM BY EARLY TO MID MORNING.
THE SOUTHEASTWARD MOVEMENT OF THE PCPN WILL BE SLOW...PROBABLY NOT
REACHING GRR UNTIL MID TO LATE AFTERNOON...AND ONLY REACHING THE
JXN AREA INTO THE EVENING.
THE UPPER FORCING AND FGEN PRODUCING THIS PCPN LOOKS WEAKER THAN
WHAT WAS SEEN ON PREVIOUS MODEL RUNS. I AM STILL HIGHLY CONFIDENT
IN MEASURABLE RAIN...HOWEVER IT NO LONGER LOOKS LIKE A GOOD
SOAKING RAIN. MOST AREAS WILL PROBABLY END UP WITH A QUARTER TO A
HALF INCH OF RAIN.
AS HAS BEEN THE TREND WITH THE MODELS...THIS SYSTEM MOVES OUT MUCH
QUICKER...AND MUCH OF THE PCPN SHOULD BE EAST BY 12Z FRIDAY. HAVE
REMOVE THE LOW CHANCE POPS FOR FRIDAY.
A VERY DRY AIR MASS FOLLOWS FOR FRIDAY NIGHT AND SATURDAY. THIS
WILL PRODUCE A LARGE DIURNAL TEMP SWING. ADJUSTED TEMPS DOWN FRIDAY
NIGHT WITH 40S COMMON. THEN INCREASED MAX TEMPS ON SATURDAY...WARMING
TO 70 TO 75.
MEANWHILE...IT LOOKS LIKE MUCH OF THE CWA WILL SEE SOME EARLY
MORNING SUNSHINE TODAY. SO HAVE ALSO INCREASED MAX TEMPS FOR TODAY
WITH THE EXCEPTION BEING IN THE NW CWA WHERE THE RAIN WILL ARRIVE
EARLY...HOLDING TEMPS IN THE 60S THERE.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 340 AM EDT THU SEP 13 2012
AS THE SFC RIDGE MOVES SLOWLY OFF TO THE EAST SATURDAY NIGHT AND
SUNDAY... A WARM ADVECTION PATTERN DEVELOPS AND TEMPERATURES WILL
MODERATE. THE ATMOSPHERE REMAINS QUITE DRY HOWEVER AND WOULD EXPECT
SKIES TO REMAIN MOSTLY CLEAR UNTIL MONDAY AFTERNOON WHEN THE NEXT
COLD FRONT APPROACHES FROM THE WEST. THAT FRONT WILL BRING OUR NEXT
CHANCE OF RAIN SHOWERS LATE MONDAY AND MONDAY NIGHT.
A DEEP H5 TROUGH IS PROGGED TO DIG INTO THE REGION ON TUESDAY WITH
SOME RATHER CHILLY AIR RUSHING IN BEHIND THE COLD FRONT MONDAY
NIGHT. H8 TEMPS DROPPING DOWN TO 1-3C WILL BE PLENTY COLD TO
GENERATE SOME ADDITIONAL LAKE EFFECT CLOUDS AND RAIN SHOWERS BEHIND
THE FRONT ON TUESDAY. THE PATTERN LOOKS PROGRESSIVE HOWEVER... AND
THE TROUGH IS EXPECTED TO KICK OUT ON TUESDAY NIGHT... WITH WARM
ADVECTION RETURNING ALREADY ON WEDNESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY)
ISSUED AT 1200 PM EDT THU SEP 13 2012
VFR CONDITIONS THIS AFTERNOON WILL GRADUALLY TRANSITION TO MVFR
TONIGHT AS LOW CLOUDS AND A BAND OF SHOWERS GRADUALLY MOVE IN FROM
THE WEST. SHOWERS SHOULD REACH KMKG BY LATE AFTN AND THE REST OF THE
TERMINALS THIS EVENING. CONDITIONS WILL GRADUALLY IMPROVE BACK TO
VFR FRIDAY MORNING AS THE LOWER CLOUDS AND SHOWERS EXIT THE AREA. NW
WINDS WILL RAMP UP TO 10-15 KTS BY LATE FRIDAY MORNING AS CLOUDS
SCATTER OUT BEFORE SKIES EVENTUALLY CLEAR.
&&
.MARINE...
ISSUED AT 934 AM EDT THU SEP 13 2012
WE HAVE EXPANDED THE SMALL CRAFT ADVISORY NORTH TO NOW INCLUDE THE
ENTIRE NEARSHORE. WE HAVE ALSO PULLED THE STARTING TIME OF THE
ADVISORY TO THE CURRENT TIME. THE BUOY OFF OF BIG SABLE POINT
INDICATES WAVES AROUND 5 FEET OR SO THIS MORNING IMMEDIATELY BEHIND
THE COLD FRONT MOVING THROUGH. WINDS AND WAVES ARE PICKING UP ALONG
THE ENTIRE COAST...A LITTLE QUICKER THAN EARLIER ANTICIPATED. WINDS
WILL PICK UP DOWN SOUTH TODAY...AND WINDS WILL DIMINISH LATER TODAY
AND THIS EVENING UP NORTH.
WE COULD BE FLIRTING WITH ADVISORY CRITERIA ONCE AGAIN ON FRIDAY
WITH WINDS EXPECTED TO BE APPROACHING 20 KNOTS. WITH THE COOLER AIR
OVER LAKE MICHIGAN...THAT COULD HELP BUILD WAVES ONCE AGAIN. WE WILL
LET THE CURRENT ADVISORY PLAY OUT FOR NOW. WE WILL RE-EVALUATE THE
NEED LATER TO EITHER EXTEND THE CURRENT ADVISORY...OR LET IT EXPIRE
AND ISSUE A NEW ONE IF NEEDED.
&&
.HYDROLOGY...
ISSUED AT 340 AM EDT THU SEP 13 2012
MOST AREAS WILL SEE LESS THAN A HALF INCH OF RAIN LATER TODAY
THROUGH TONIGHT. THIS WILL NOT CAUSE ANY HYDRO ISSUES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR
LMZ847>849.
SMALL CRAFT ADVISORY UNTIL 4 AM EDT FRIDAY FOR LMZ844>846.
&&
$$
UPDATE...DUKE
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...MEADE
AVIATION...LAURENS
HYDROLOGY...JK
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1059 AM EDT THU SEP 13 2012
.SYNOPSIS...
ISSUED AT 340 AM EDT THU SEP 13 2012
CLOUDS WILL INCREASE THIS MORNING AND SHOWERS WILL GRADUALLY
BECOME MORE COMMONPLACE INTO THE AFTERNOON AND EVENING. THE RAIN
IS EXPECTED TO END FROM NORTHWEST TO SOUTHEAST LATER TONIGHT. HIGH
PRESSURE WILL RETURN FOR THE WEEKEND BRINGING SUNSHINE AND
TEMPERATURES IN THE UPPER 60S TO MID 70S.
&&
.UPDATE...
ISSUED AT 1058 AM EDT THU SEP 13 2012
TOUCHED UP THE FORECAST FROM THIS AFTERNOON THROUGH TONIGHT IN
TERMS OF POPS AND WEATHER. FOLLOWED THE LEAD OF BOTH THE HRRR AND
THE NSSL 4KM WRF MODELS WHICH BRING A BAND OF RAIN THROUGH THE
FORECAST AREA LATE THIS AFTERNOON THROUGH TONIGHT. MAIN CHANGE WAS
TO BACK OFF ON THE ARRIVAL TIME A BIT. THROUGH THIS
AFTERNOON AND EARLY EVENING...THE FAR NORTHWEST CWA NORTH OF MUSKEGON
AND BIG RAPIDS SHOULD BE THE MAIN AREA THAT IS AFFECTED BY RAIN.
IT WILL TAKE MORE INTO THE EVENING AND AFTER DARK TO AFFECT AREAS
LIKE GRAND RAPIDS. TEMPERATURES WILL BE HELD DOWN BY THE CLOUDS
MOVING INTO THE FAR NORTHWEST FORECAST AREA. TOWARD JXN HOWEVER
READINGS WILL LIKELY PUSH AT LEAST TO AROUND 80...IF NOT ECLIPSING
IT SLIGHTLY.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 340 AM EDT THU SEP 13 2012
A BAND OF RAIN WAS MOVING ACROSS WISCONSIN THIS MORNING AND SHOULD
REACH THE NW CORNER OF THE CWA NEAR LDM BY EARLY TO MID MORNING.
THE SOUTHEASTWARD MOVEMENT OF THE PCPN WILL BE SLOW...PROBABLY NOT
REACHING GRR UNTIL MID TO LATE AFTERNOON...AND ONLY REACHING THE
JXN AREA INTO THE EVENING.
THE UPPER FORCING AND FGEN PRODUCING THIS PCPN LOOKS WEAKER THAN
WHAT WAS SEEN ON PREVIOUS MODEL RUNS. I AM STILL HIGHLY CONFIDENT
IN MEASURABLE RAIN...HOWEVER IT NO LONGER LOOKS LIKE A GOOD
SOAKING RAIN. MOST AREAS WILL PROBABLY END UP WITH A QUARTER TO A
HALF INCH OF RAIN.
AS HAS BEEN THE TREND WITH THE MODELS...THIS SYSTEM MOVES OUT MUCH
QUICKER...AND MUCH OF THE PCPN SHOULD BE EAST BY 12Z FRIDAY. HAVE
REMOVE THE LOW CHANCE POPS FOR FRIDAY.
A VERY DRY AIR MASS FOLLOWS FOR FRIDAY NIGHT AND SATURDAY. THIS
WILL PRODUCE A LARGE DIURNAL TEMP SWING. ADJUSTED TEMPS DOWN FRIDAY
NIGHT WITH 40S COMMON. THEN INCREASED MAX TEMPS ON SATURDAY...WARMING
TO 70 TO 75.
MEANWHILE...IT LOOKS LIKE MUCH OF THE CWA WILL SEE SOME EARLY
MORNING SUNSHINE TODAY. SO HAVE ALSO INCREASED MAX TEMPS FOR TODAY
WITH THE EXCEPTION BEING IN THE NW CWA WHERE THE RAIN WILL ARRIVE
EARLY...HOLDING TEMPS IN THE 60S THERE.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 340 AM EDT THU SEP 13 2012
AS THE SFC RIDGE MOVES SLOWLY OFF TO THE EAST SATURDAY NIGHT AND
SUNDAY... A WARM ADVECTION PATTERN DEVELOPS AND TEMPERATURES WILL
MODERATE. THE ATMOSPHERE REMAINS QUITE DRY HOWEVER AND WOULD EXPECT
SKIES TO REMAIN MOSTLY CLEAR UNTIL MONDAY AFTERNOON WHEN THE NEXT
COLD FRONT APPROACHES FROM THE WEST. THAT FRONT WILL BRING OUR NEXT
CHANCE OF RAIN SHOWERS LATE MONDAY AND MONDAY NIGHT.
A DEEP H5 TROUGH IS PROGGED TO DIG INTO THE REGION ON TUESDAY WITH
SOME RATHER CHILLY AIR RUSHING IN BEHIND THE COLD FRONT MONDAY
NIGHT. H8 TEMPS DROPPING DOWN TO 1-3C WILL BE PLENTY COLD TO
GENERATE SOME ADDITIONAL LAKE EFFECT CLOUDS AND RAIN SHOWERS BEHIND
THE FRONT ON TUESDAY. THE PATTERN LOOKS PROGRESSIVE HOWEVER... AND
THE TROUGH IS EXPECTED TO KICK OUT ON TUESDAY NIGHT... WITH WARM
ADVECTION RETURNING ALREADY ON WEDNESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 757 AM EDT THU SEP 13 2012
VFR CONDITIONS ARE EXPECTED TODAY WITH CLOUD BASES GENERALLY 5-8K
FT. CIGS/VSBYS WILL LOWER INTO MVFR CATEGORY LATE TODAY AND THIS
EVENING FROM WEST TO EAST AS STEADIER RAINS MOVE IN. THE RAIN
TRAILS WELL BEHIND THE COLD FRONT... AND AT 12Z THE FRONT WAS
ORIENTED FROM ROUGHLY THE SAGINAW BAY TO SRN LK MI. SW WINDS WILL
SHIFT TO THE WEST THEN NORTHWEST AS THE VERY SLOW MOVING FRONT
PASSES THROUGH TODAY. THE FRONT WAS THROUGH MKG AT 12Z... BUT
PROBABLY WONT PASS THROUGH JXN UNTIL NEARLY 00Z TONIGHT. SFC WIND
SPEEDS COULD REACH 12-15 KTS FROM THE WEST SOUTHWEST FOR A PERIOD
TODAY AHEAD OF THE COLD FRONT... BETWEEN APPROX 15Z AND 20Z.
&&
.MARINE...
ISSUED AT 934 AM EDT THU SEP 13 2012
WE HAVE EXPANDED THE SMALL CRAFT ADVISORY NORTH TO NOW INCLUDE THE
ENTIRE NEARSHORE. WE HAVE ALSO PULLED THE STARTING TIME OF THE
ADVISORY TO THE CURRENT TIME. THE BUOY OFF OF BIG SABLE POINT
INDICATES WAVES AROUND 5 FEET OR SO THIS MORNING IMMEDIATELY BEHIND
THE COLD FRONT MOVING THROUGH. WINDS AND WAVES ARE PICKING UP ALONG
THE ENTIRE COAST...A LITTLE QUICKER THAN EARLIER ANTICIPATED. WINDS
WILL PICK UP DOWN SOUTH TODAY...AND WINDS WILL DIMINISH LATER TODAY
AND THIS EVENING UP NORTH.
WE COULD BE FLIRTING WITH ADVISORY CRITERIA ONCE AGAIN ON FRIDAY
WITH WINDS EXPECTED TO BE APPROACHING 20 KNOTS. WITH THE COOLER AIR
OVER LAKE MICHIGAN...THAT COULD HELP BUILD WAVES ONCE AGAIN. WE WILL
LET THE CURRENT ADVISORY PLAY OUT FOR NOW. WE WILL RE-EVALUATE THE
NEED LATER TO EITHER EXTEND THE CURRENT ADVISORY...OR LET IT EXPIRE
AND ISSUE A NEW ONE IF NEEDED.
&&
.HYDROLOGY...
ISSUED AT 340 AM EDT THU SEP 13 2012
MOST AREAS WILL SEE LESS THAN A HALF INCH OF RAIN LATER TODAY
THROUGH TONIGHT. THIS WILL NOT CAUSE ANY HYDRO ISSUES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LMZ847>849.
SMALL CRAFT ADVISORY UNTIL 4 AM EDT FRIDAY FOR LMZ844>846.
&&
$$
UPDATE...DUKE
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...JK
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS DULUTH MN
705 AM CDT THU SEP 13 2012
.AVIATION.../12Z TAF ISSUANCE/
HIGH AND MID LEVEL CLOUDS WILL PERSIST TODAY AS AN UPPER LEVEL
LOW TRACKS SOUTHEAST OVER THE REGION. WINDS WILL BECOME GUSTY
BY THIS AFTERNOON...WITH THE STRONGEST WINDS AT KBRD. A FEW LIGHT
SHOWERS WILL BE POSSIBLE LATE TODAY...MAINLY NEAR KINL TO KHIB.
SKIES WILL CLEAR AFTER MIDNIGHT WITH BUILDING HIGH PRESSURE.
&&
.PREV DISCUSSION... /ISSUED 410 AM CDT THU SEP 13 2012/
SHORT TERM..CONVEYOR BELT OF UPPER LVL MOISTURE CONTINUES TO
MOVE NORTHEAST OVER ERN HALF OF CWA...ASSOCIATED WITH FORWARD
FLANK OF 30H TROF. BDRY LYR FEATURES A CYCLONIC FLOW OF RELATIVELY
DRY AIR UNDERCUTTING MOIST AIR ALOFT. A FEW SPRINKLES OR SHOWERS
ARE POSSIBLE THROUGH EARLY MORNING OVER PRICE COUNTY. WEDGE OF VERY
DRY AIR WITHIN 925/850 LYR HAS ADVECTED INTO AREA FROM TWIN PORTS
SOUTHWEST TO BRD LAKES VICINITY. A SECONDARY COLD FRONT IS LOCATED
OVER CTRL MAN/ONTARIO WITH DECENT LOW LVL THERMAL RIBBON INDICATED
IN RAP 925 ANALYSIS. LARGE MID/UPPER LVL LOW OVER ERN SASK IS
MOVING SE WITH GRADUAL MOISTENING OF LOWER LAYERS ACROSS SRN
MAN/ONTARIO.
TODAY...UPPER LOW OVER SASK WILL TRACK TOWARDS KINL BY EARLY
EVENING. CLOUDS WILL INCREASE WITH SLGT CHC PRECIP NEAR BORDER
THIS AFTN. MAX TEMPS IN NRN LAKE/COOK COUNTIES A BIT ON THE
CHILLY SIDE. STEEPENING LAPSE RATES WITH MID LVL MOISTURE MAY
GENERATE CONSIDERABLE VIRGA TODAY ACROSS NRN HALF OF MN ZONES.
BEST FORCING WILL REMAIN NEAR SECONDARY COLD FRONT NORTH OF THE
BORDER. VERY DEEP MIXING LAYER 0F 8K TO 10K TODAY ACROSS MOST OF
THE CWA SHOULD ALLOW MOMENTUM TRANSFER AND GUSTY WINDS. GUSTS WILL
NOT BE AS HIGH AS YESTERDAY AS CORE OF STRONGER WINDS ALOFT WILL
HAVE SHIFTED EAST OF REGION. ELEVATED FIRE DANGER MAY DEVELOP OVER
SWRN/SCTRL CWA IN THE AREA OF LOWEST RH AND GUSTY WINDS.
TONIGHT...MID LVL LOW MOVES TO ERN LAKE SUPERIOR WITH DEEP LYR
DRYING EXPECTED TO COVER MOST OF CWA BY EARLY FRIDAY. SFC HIGH
WILL MOVE INTO CWA WITH WINDS SUBSIDING. LATEST SREF PLUMES
SUPPORT TEMPS IN LOW/MID 30S RANGE OVER MOST OF CWA INLAND FROM
LAKE SUPERIOR. HAVE ISSUED FROST ADVISORY FOR CWA EXCEPT NSHORE
ZONES...AND ERN MOST WISC ZONES. CLOUD COVERAGE AND MIXING WILL
BE SLOWEST TO LEAVE ERN WISC ZONES. FROST DURATION MAY BE FAIRLY
LIMITED IN MOST LOCATIONS DUE TO INITIAL CLOUD COVERAGE AND WIND.
TOMORROW...VERY PLEASANT WEATHER PATTERN AS SFC/MID LVL RIDGING
PREVAIL FOR MOST OF THE DAY. NEAR CLIMO TEMPS AND ABUNDANT SUNSHINE.
LONG TERM...FRIDAY NIGHT THROUGH THURSDAY.
SFC HIGH PRESSURE AND MID LEVEL RIDGING WILL PREVAIL FRIDAY
RESULTING IN A DRY DAY WITH LIGHT WINDS. A TRANSITION TO WAA AND A
SRLY FLOW IS FOUND FRIDAY NIGHT AS AN ELONGATED H85 TROUGH MOVES
INTO THE LEE OF THE ROCKIES/WESTERN DAKOTAS. THE NORTHLAND REMAINS
SITUATED AHEAD OF THE TROUGH IN THE STRONG WAA SATURDAY...ALLOWING
FOR WELL ABOVE NORMAL TEMPS...IN THE 70S TO AROUND 80...AND GUSTY
SOUTH-SOUTHWEST WINDS. THE LATEST GFS/ECM/GEM ARE SHOWING GOOD
AGREEMENT THAT H85 TEMPS COMMENCE IN THE SINGLE DIGITS FRIDAY
EVENING...REACHING THE MID AND TEENS BY SATURDAY EVENING.
TEMPERATURES WILL BE COOLER ALONG THE NORTH SHORE OF LAKE SUPERIOR
WITH A LIGHT ONSHORE WIND.
THE LONG WAVE TROUGH AND H50 VORT...ACCOMPANIED BY A STRONG SFC COLD
FRONT...WILL SWEEP SOUTHEAST OVER THE REGION SUNDAY NIGHT INTO
MONDAY. THE FROPA WILL BRING RAIN SHOWERS...GUSTY NORTHWEST
WINDS...AND MUCH COOLER TEMPERATURES. HAVE LOWERED HIGHS MONDAY INTO
THE 50S AS A POTENT CAA REGIME WILL LIMIT MUCH WARMING AND KEEP
CLOUDS AND SHOWERS AROUND. LONG TERM MODELS CONTINUE TO SHOW H85
TEMPS FALL INTO THE NEGATIVE SINGLE DIGITS WITH H50 TEMPS
APPROACHING NEGATIVE 30 ACROSS THE BORDERLAND MONDAY NIGHT. THE COLD
TEMPS...STEEP LAPSE RATES...AND H10-H50 THICKNESSES OF 530 DAM
SUPPORT A CHANCE FOR ANY LINGERING RAIN SHOWERS IN THE MN ARROWHEAD
ZONES TO MIX WITH SNOW. HOWEVER...LITTLE OR NO ACCUMULATION IS
EXPECTED.
THE NORTHLAND REMAINS UNDER THE BROAD CYCLONIC FLOW THROUGH THE
REMAINDER OF THE WEEK...KEEPING COOLER TEMPERATURES AND ONGOING
CHANCES FOR SHOWERS THROUGH THE EXTENDED. .
&&
.POINT TEMPS/POPS...
DLH 65 37 68 40 / 10 10 0 0
INL 61 34 68 37 / 20 0 0 0
BRD 67 36 72 38 / 10 0 0 0
HYR 66 32 69 36 / 10 10 0 0
ASX 67 39 68 39 / 10 10 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...FROST ADVISORY FROM 2 AM TO 8 AM CDT FRIDAY FOR MNZ010>012-018-
019-025-026-033>038.
WI...FROST ADVISORY FROM 2 AM TO 8 AM CDT FRIDAY FOR WIZ001-002-
006>008.
LS...NONE.
&&
$$
AVIATION...GRANING
AREA FORECAST DISCUSSION
NWS DULUTH MN
410 AM CDT THU SEP 13 2012
.SHORT TERM..CONVEYOR BELT OF UPPER LVL MOISTURE CONTINUES TO
MOVE NORTHEAST OVER ERN HALF OF CWA...ASSOCIATED WITH FORWARD
FLANK OF 30H TROF. BDRY LYR FEATURES A CYCLONIC FLOW OF RELATIVELY
DRY AIR UNDERCUTTING MOIST AIR ALOFT. A FEW SPRINKLES OR SHOWERS
ARE POSSIBLE THROUGH EARLY MORNING OVER PRICE COUNTY. WEDGE OF VERY
DRY AIR WITHIN 925/850 LYR HAS ADVECTED INTO AREA FROM TWIN PORTS
SOUTHWEST TO BRD LAKES VICINITY. A SECONDARY COLD FRONT IS LOCATED
OVER CTRL MAN/ONTARIO WITH DECENT LOW LVL THERMAL RIBBON INDICATED
IN RAP 925 ANALYSIS. LARGE MID/UPPER LVL LOW OVER ERN SASK IS
MOVING SE WITH GRADUAL MOISTENING OF LOWER LAYERS ACROSS SRN
MAN/ONTARIO.
TODAY...UPPER LOW OVER SASK WILL TRACK TOWARDS KINL BY EARLY
EVENING. CLOUDS WILL INCREASE WITH SLGT CHC PRECIP NEAR BORDER
THIS AFTN. MAX TEMPS IN NRN LAKE/COOK COUNTIES A BIT ON THE
CHILLY SIDE. STEEPENING LAPSE RATES WITH MID LVL MOISTURE MAY
GENERATE CONSIDERABLE VIRGA TODAY ACROSS NRN HALF OF MN ZONES.
BEST FORCING WILL REMAIN NEAR SECONDARY COLD FRONT NORTH OF THE
BORDER. VERY DEEP MIXING LAYER 0F 8K TO 10K TODAY ACROSS MOST OF
THE CWA SHOULD ALLOW MOMENTUM TRANSFER AND GUSTY WINDS. GUSTS WILL
NOT BE AS HIGH AS YESTERDAY AS CORE OF STRONGER WINDS ALOFT WILL
HAVE SHIFTED EAST OF REGION. ELEVATED FIRE DANGER MAY DEVELOP OVER
SWRN/SCTRL CWA IN THE AREA OF LOWEST RH AND GUSTY WINDS.
TONIGHT...MID LVL LOW MOVES TO ERN LAKE SUPERIOR WITH DEEP LYR
DRYING EXPECTED TO COVER MOST OF CWA BY EARLY FRIDAY. SFC HIGH
WILL MOVE INTO CWA WITH WINDS SUBSIDING. LATEST SREF PLUMES
SUPPORT TEMPS IN LOW/MID 30S RANGE OVER MOST OF CWA INLAND FROM
LAKE SUPERIOR. HAVE ISSUED FROST ADVISORY FOR CWA EXCEPT NSHORE
ZONES...AND ERN MOST WISC ZONES. CLOUD COVERAGE AND MIXING WILL
BE SLOWEST TO LEAVE ERN WISC ZONES. FROST DURATION MAY BE FAIRLY
LIMITED IN MOST LOCATIONS DUE TO INITIAL CLOUD COVERAGE AND WIND.
TOMORROW...VERY PLEASANT WEATHER PATTERN AS SFC/MID LVL RIDGING
PREVAIL FOR MOST OF THE DAY. NEAR CLIMO TEMPS AND ABUNDANT SUNSHINE.
LONG TERM...FRIDAY NIGHT THROUGH THURSDAY.
SFC HIGH PRESSURE AND MID LEVEL RIDGING WILL PREVAIL FRIDAY
RESULTING IN A DRY DAY WITH LIGHT WINDS. A TRANSITION TO WAA AND A
SRLY FLOW IS FOUND FRIDAY NIGHT AS AN ELONGATED H85 TROUGH MOVES
INTO THE LEE OF THE ROCKIES/WESTERN DAKOTAS. THE NORTHLAND REMAINS
SITUATED AHEAD OF THE TROUGH IN THE STRONG WAA SATURDAY...ALLOWING
FOR WELL ABOVE NORMAL TEMPS...IN THE 70S TO AROUND 80...AND GUSTY
SOUTH-SOUTHWEST WINDS. THE LATEST GFS/ECM/GEM ARE SHOWING GOOD
AGREEMENT THAT H85 TEMPS COMMENCE IN THE SINGLE DIGITS FRIDAY
EVENING...REACHING THE MID AND TEENS BY SATURDAY EVENING.
TEMPERATURES WILL BE COOLER ALONG THE NORTH SHORE OF LAKE SUPERIOR
WITH A LIGHT ONSHORE WIND.
THE LONG WAVE TROUGH AND H50 VORT...ACCOMPANIED BY A STRONG SFC COLD
FRONT...WILL SWEEP SOUTHEAST OVER THE REGION SUNDAY NIGHT INTO
MONDAY. THE FROPA WILL BRING RAIN SHOWERS...GUSTY NORTHWEST
WINDS...AND MUCH COOLER TEMPERATURES. HAVE LOWERED HIGHS MONDAY INTO
THE 50S AS A POTENT CAA REGIME WILL LIMIT MUCH WARMING AND KEEP
CLOUDS AND SHOWERS AROUND. LONG TERM MODELS CONTINUE TO SHOW H85
TEMPS FALL INTO THE NEGATIVE SINGLE DIGITS WITH H50 TEMPS
APPROACHING NEGATIVE 30 ACROSS THE BORDERLAND MONDAY NIGHT. THE COLD
TEMPS...STEEP LAPSE RATES...AND H10-H50 THICKNESSES OF 530 DAM
SUPPORT A CHANCE FOR ANY LINGERING RAIN SHOWERS IN THE MN ARROWHEAD
ZONES TO MIX WITH SNOW. HOWEVER...LITTLE OR NO ACCUMULATION IS
EXPECTED.
THE NORTHLAND REMAINS UNDER THE BROAD CYCLONIC FLOW THROUGH THE
REMAINDER OF THE WEEK...KEEPING COOLER TEMPERATURES AND ONGOING
CHANCES FOR SHOWERS THROUGH THE EXTENDED. .
.AVIATION.../06Z TAF ISSUANCE/
HIGH CLOUDS WILL CONTINUE TO STREAM THROUGH THE NORTHLAND
OVERNIGHT...BUT THE CLOUDS WILL GRADUALLY DECREASE. MEANWHILE...A
COLD CORE WILL MOVE TO THE SOUTHEAST ACROSS THE REGION. THIS WILL
RESULT IN SOME LOW TO MID CLOUDS THURSDAY AFTERNOON AND EVENING.
WINDS WILL BE A BIT GUSTY DURING THE DAY...BUT THEN DECREASE QUICKLY
BY THURSDAY EVENING.
.POINT TEMPS/POPS...
DLH 65 37 68 40 / 10 10 0 0
INL 61 34 68 37 / 20 0 0 0
BRD 67 36 72 38 / 10 0 0 0
HYR 66 32 69 36 / 10 10 0 0
ASX 67 39 68 39 / 10 10 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...FROST ADVISORY FROM 2 AM TO 8 AM CDT FRIDAY FOR MNZ010>012-018-
019-025-026-033>038.
WI...FROST ADVISORY FROM 2 AM TO 8 AM CDT FRIDAY FOR WIZ001-002-
006>008.
LS...NONE.
&&
$$
SHORT TERM...CANNON
LONG TERM....GRANING
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1234 PM CDT Thu Sep 13 2012
...UPDATED AVIATION DISCUSSION...
.DISCUSSION...
/412 AM CDT THU SEP 13 2012/
Short Range (Today through Saturday)...
Primary weather concerns are focused over the next 18 hours. By
sunrise a cold front which entered northwest MO Wednesday evening
will have made it through the entire CWA. A pronounced upper trough
over the Northern and Central Plains will slide east-southeast
through MN/IA/MO today. While there has been little to no
pre-frontal convection multi-layered frontogenesis and isentropic
ascent primarily on the 305K surface have resulted in a sw-ne
oriented band of convection from KS through IA. However, this band
has steadily narrowed and decreased in intensity since midnight.
Have placed a strong emphasis on the 00Z NAM and LSX local WRF which
projected a steady weakening of the frontogenetical forcing as well
as just about eliminating the isentropic ascent by mid morning
today. Radar trends and latest HRRR model output further support
these two models. So, have lowered pops over most areas except the
far northwestern CWA.
Would have lowered them further except for a little fly in the
ointment...layered clouds/scattered convection associated with an
upper low just south of the 4-corners area is being tapped into by
the Plains upper trough. These scattered showers are being lifted
northeast and should see some of this moisture spread into the the
west central CWA by this afternoon...and possibly reaching into
central MO by late afternoon. Have also lowered temperatures within
the expected areas of showers and decent cold air advection.
Weak high pressure will move into the Central Plains and MO on
Friday although some semblance of the upper low will be hanging
around from NM into southern KS. This creates a little uncertainty
as to how far south the clearing will push south as well as the
threat of some showers possibly reaching the far southwestern
counties. Otherwise, looking at some very pleasant weather into the
first part of the weekend.
MJ
Medium Range (Sunday through Wednesday)...
The cutoff low that forms across the southern High Plains this
weekend begins to eject eastward on Sunday, as the southwesterly jet
over the Texas Panhandle strengthens. The resultant wave appears a
bit weaker as it shifts eastward in the latest model runs, but could
still produce some widely scattered precipitation across southern
portions of the CWA on Sunday. Also on Sunday, the next deep trough
across the Northern Plains begins diving southeastward into the
forecast area, beginning the chance of precipitation across our
northwest by Sunday night. Most operational models kick this system
through fairly quickly on Monday, with the exception of the GEM and
a few of the GFS ensemble members, so have cut back precipitation
chances to the south and east on Monday night and Tuesday. Another
front will likely drop through the region sometime in the Wednesday
- Thursday timeframe again next week, and have kept in a chance of
precipitation Wednesday night when most models bring the boundary
through. Temperatures will be primarily below average through the
extended forecast, with little chance for recovery between potent
cold frontal passages.
Laflin
&&
.AVIATION...
For the 18Z TAFs...Axis of showers is slowly settling southeast
behind the cold front that drove south through Kansas and Missouri
overnight. Gusty 10 to 15 knot northeast winds behind the front continue
to advect in sufficiently dry air to keep ceilings in the MVFR
category this afternoon, though visibilities will likely be reduced
for brief periods as heavier showers occur along the leading edge of
the advancing moisture axis. By this evening ceilings will be going
up as more dry air moves in behind the front, with winds turning to
due east Friday morning.
Cutter
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
649 AM CDT THU SEP 13 2012
...UPDATED AVIATION DISCUSSION...
.DISCUSSION...
/412 AM CDT THU SEP 13 2012/
Short Range (Today through Saturday)...
Primary weather concerns are focused over the next 18 hours. By
sunrise a cold front which entered northwest MO Wednesday evening
will have made it through the entire CWA. A pronounced upper trough
over the Northern and Central Plains will slide east-southeast
through MN/IA/MO today. While there has been little to no
pre-frontal convection multi-layered frontogenesis and isentropic
ascent primarily on the 305K surface have resulted in a sw-ne
oriented band of convection from KS through IA. However, this band
has steadily narrowed and decreased in intensity since midnight.
Have placed a strong emphasis on the 00Z NAM and LSX local WRF which
projected a steady weakening of the frontogenetical forcing as well
as just about eliminating the isentropic ascent by mid morning
today. Radar trends and latest HRRR model output further support
these two models. So, have lowered pops over most areas except the
far northwestern CWA.
Would have lowered them further except for a little fly in the
ointment...layered clouds/scattered convection associated with an
upper low just south of the 4-corners area is being tapped into by
the Plains upper trough. These scattered showers are being lifted
northeast and should see some of this moisture spread into the the
west central CWA by this afternoon...and possibly reaching into
central MO by late afternoon. Have also lowered temperatures within
the expected areas of showers and decent cold air advection.
Weak high pressure will move into the Central Plains and MO on
Friday although some semblance of the upper low will be hanging
around from NM into southern KS. This creates a little uncertainty
as to how far south the clearing will push south as well as the
threat of some showers possibly reaching the far southwestern
counties. Otherwise, looking at some very pleasant weather into the
first part of the weekend.
MJ
Medium Range (Sunday through Wednesday)...
The cutoff low that forms across the southern High Plains this
weekend begins to eject eastward on Sunday, as the southwesterly jet
over the Texas Panhandle strengthens. The resultant wave appears a
bit weaker as it shifts eastward in the latest model runs, but could
still produce some widely scattered precipitation across southern
portions of the CWA on Sunday. Also on Sunday, the next deep trough
across the Northern Plains begins diving southeastward into the
forecast area, beginning the chance of precipitation across our
northwest by Sunday night. Most operational models kick this system
through fairly quickly on Monday, with the exception of the GEM and
a few of the GFS ensemble members, so have cut back precipitation
chances to the south and east on Monday night and Tuesday. Another
front will likely drop through the region sometime in the Wednesday
- Thursday timeframe again next week, and have kept in a chance of
precipitation Wednesday night when most models bring the boundary
through. Temperatures will be primarily below average through the
extended forecast, with little chance for recovery between potent
cold frontal passages.
Laflin
&&
.AVIATION...
For the 12Z TAFs...00Z NAM and latest HRRR are handling the post
frontal showers best. They favor hit and miss type showers at all 3
terminals. Showers have a better chance of becoming more numerous
early this afternoon but confidence is not overly high. So best to
handle using VCSH until/if they become more organized. Instability
is very limited so will forgo mention of thunder. Mainly MVFR
ceilings between KMCI and KSTJ which should work into KMKC. Unless
the showers become heavier not expecting IFR conditions this
morning. Shower threat should end early afternoon at KSTJ and shift
south into KC area by late afternoon with improving ceiling heights.
VFR conditions from tonight through the rest of the forecast period
with light and variable winds.
MJ
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
412 AM CDT THU SEP 13 2012
.DISCUSSION...
Short Range (Today through Saturday)...
Primary weather concerns are focused over the next 18 hours. By
sunrise a cold front which entered northwest MO Wednesday evening
will have made it through the entire CWA. A pronounced upper trough
over the Northern and Central Plains will slide east-southeast
through MN/IA/MO today. While there has been little to no
pre-frontal convection multi-layered frontogenesis and isentropic
ascent primarily on the 305K surface have resulted in a sw-ne
oriented band of convection from KS through IA. However, this band
has steadily narrowed and decreased in intensity since midnight.
Have placed a strong emphasis on the 00Z NAM and LSX local WRF which
projected a steady weakening of the frontogenetical forcing as well
as just about eliminating the isentropic ascent by mid morning
today. Radar trends and latest HRRR model output further support
these two models. So, have lowered pops over most areas except the
far northwestern CWA.
Would have lowered them further except for a little fly in the
ointment...layered clouds/scattered convection associated with an
upper low just south of the 4-corners area is being tapped into by
the Plains upper trough. These scattered showers are being lifted
northeast and should see some of this moisture spread into the the
west central CWA by this afternoon...and possibly reaching into
central MO by late afternoon. Have also lowered temperatures within
the expected areas of showers and decent cold air advection.
Weak high pressure will move into the Central Plains and MO on
Friday although some semblance of the upper low will be hanging
around from NM into southern KS. This creates a little uncertainty
as to how far south the clearing will push south as well as the
threat of some showers possibly reaching the far southwestern
counties. Otherwise, looking at some very pleasant weather into the
first part of the weekend.
MJ
Medium Range (Sunday through Wednesday)...
The cutoff low that forms across the southern High Plains this
weekend begins to eject eastward on Sunday, as the southwesterly jet
over the Texas Panhandle strengthens. The resultant wave appears a
bit weaker as it shifts eastward in the latest model runs, but could
still produce some widely scattered precipitation across southern
portions of the CWA on Sunday. Also on Sunday, the next deep trough
across the Northern Plains begins diving southeastward into the
forecast area, beginning the chance of precipitation across our
northwest by Sunday night. Most operational models kick this system
through fairly quickly on Monday, with the exception of the GEM and
a few of the GFS ensemble members, so have cut back precipitation
chances to the south and east on Monday night and Tuesday. Another
front will likely drop through the region sometime in the Wednesday
- Thursday timeframe again next week, and have kept in a chance of
precipitation Wednesday night when most models bring the boundary
through. Temperatures will be primarily below average through the
extended forecast, with little chance for recovery between potent
cold frontal passages.
Laflin
&&
.AVIATION...
For the 06Z TAFs...surface cold front is currently between MCI and
MKC and stretches northeastward into north central Missouri. This
front will continue to push southeast into the MKC and OJC terminals
over the next couple of hours. While there could be a few scattered
showers or even a brief thunderstorm near the front, the bulk of the
rainfall remains well behind the front. This activity is approaching
STJ where occasional MVFR or even IFR restrictions are likely.
This area of rain is still expected to gradually scatter out and
weaken as it spreads southward toward sunrise so that prolonged rain
may not occur as far south as MCI or MKC. However, models indicate
that scattered low clouds in high-end IFR or low-end MVFR may make it
as far south of the KC terminals before scattering and lifting
through mid morning.
Hawblitzel
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1211 AM CDT THU SEP 13 2012
.UPDATE...
ISSUED AT 930 PM CDT WED SEP 12 2012
CURRENT FORECAST LOOKS PRETTY MUCH ON TRACK FOR THE REST OF THE
NIGHT. COLD FRONT IS NOW STRETCHING FROM NEAR DAVENPORT IA
SOUTHWEST TO JUST NORTH OF THE KC METRO AREA. CURRENT RAP FORECAST
HAS IT PUSHING THROUGH KIRKSVILLE AROUND 09Z AND DOWN TO ALONG A
COLUMBIA MO-QUINCY IL LINE BY 12Z. NEW NAM AGREES WITH THIS
POSITION...THO THE TRUE LOW LEVEL BAROCLINICITY LAGS BACK IN
NORTHWEST/NORTH CENTRAL MISSOURI AT 12Z. STILL THINK THE AREA WILL
REMAIN DRY AT LEAST UNTIL THEN...POTENTIALLY INTO MID MORNING
THURSDAY. CURRENT TEMPERATURES ARE WITHIN 1 TO 2 DEGREES OF
FORECAST...SO TEMP TRENDS LOOK ON TRACK AT THIS TIME.
CARNEY
&&
.SHORT TERM...
ISSUED AT 208 PM CDT WED SEP 12 2012
(TONIGHT)
COLD FRONT CURRENTLY STRETCHING FROM SOUTHEAST NEBRASKA TO EASTERN
WISCONSIN WILL CONTINUE TO SLOWLY EDGE ITS WAY SOUTH TONIGHT AND
BE KNOCKING ON THE FAR NORTHERN PORTION OF THE CWA BY 12Z. RAIN
CONTINUES TO BE POST FRONTAL WITH THIS SYSTEM...SO THE FORECAST
REMAINS DRY OVERNIGHT. SOUTHERLY WIND AND INCREASING LOW LEVEL
MOISTURE SHOULD KEEP TEMPERATURES SLIGHTLY ABOVE NORMAL...WITH A
NOD GOING TO THE WARMER MET GUIDANCE.
CVKING
&&
.LONG TERM...
ISSUED AT 344 PM CDT WED SEP 12 2012
(THURSDAY THROUGH WEDNESDAY)
COLD FRONT WILL BE OVER NORTHERN PORTIONS OF FORECAST AREA BY
DAYBREAK THURSDAY MORNING...WITH SHOWERS SPREADING INTO THE
REGION...MAINLY POST FRONTAL. BEST CHANCES WILL BE OVER NORTHEAST
MO/WEST CENTRAL IL DURING THE DAY ON THURSDAY...THEN INCREASE IN
COVERAGE ACROSS REST OF FORECAST AREA THURSDAY EVENING. NOT A LOT OF
INSTABILITY WITH THIS SYSTEM...SO SHOULD BE MOSTLY RAIN/SHOWERS...
THOUGH SOME ISOLATED STORMS NOT OUT OF THE QUESTION FOR CENTRAL MO
THURSDAY AFTERNOON...SO LEFT MENTION IN THERE. MODELS CONTINUE TO BE
A LOT FASTER WITH ENDING THE PCPN...SO HAVE LOWERED POPS AFTER 06Z
FRIDAY AND HAVE PCPN COMING TO AN END AT ALL LOCATIONS BY 18Z FRIDAY.
AS FOR HIGHS ON THURSDAY...WILL BE DEPENDENT ON CLOUD COVER AND PCPN
COVERAGE. FOR NOW SHOULD SEE HIGHS RANGING FROM THE UPPER 60S FAR
NORTH TO THE LOW 80S ALONG AND SOUTH OF I-70. ALSO...WILL BE GOING
WITH A NON DIURNAL TREND...MAINLY FOR NORTHERN PORTIONS OF FORECAST
AREA...WITH HIGH TEMPS IN THE LATE MORNING HOURS...THEN TEMPS STEADY
OR SLOWLY FALLING DURING THE AFTERNOON HOURS.
BY THURSDAY NIGHT...COLDER AIR TO BEGIN FILTERING IN WITH LOWS IN
THE MID 40S TO MID 50S.
WILL SEE MORE FALL LIKE WEATHER ONCE AGAIN THROUGH THE WEEKEND.
HIGHS ON FRIDAY WILL BE IN THE LOW 70S AND IN THE MID 70S ON
SATURDAY. AS FOR LOW TEMPS...WILL SEE ANOTHER COLD NIGHT FRIDAY
NIGHT WITH LOWS IN THE UPPER 40S TO LOW 50S.
STRONG SURFACE RIDGE TO BEGIN MOVING OFF TO THE EAST LATE IN THE
WEEKEND AND INTO EARLY NEXT WEEK WITH TEMPS MODERATING A BIT. HIGHS
WILL BE IN THE UPPER 70S SUNDAY AND MONDAY.
THEN ANOTHER STRONG COLD FRONT TO MOVE INTO THE REGION ON
MONDAY...BRINGING ANOTHER CHANCE FOR SHOWERS AND THUNDERSTORMS
MONDAY AND MONDAY NIGHT. BEHIND THE SYSTEM...COOLER THAN NORMAL
WEATHER TO PERSIST WITH HIGHS IN THE MID 60S TO MID 70S WITH LOWS IN
THE MID 40S BY TUESDAY MORNING.
BYRD
&&
.AVIATION...
ISSUED AT 1210 AM CDT THU SEP 13 2012
VFR CONDITIONS AND LIGHT S FLOW WILL CONTINUE AREAWIDE...AHEAD OF
THE CDFNT...WHICH IS CURRENTLY FROM SERN IA TO NWRN MO. CDFNT
CONTINUES TO RUN A BIT SLOWER THAN ORIGINALLY THOUGHT...AND SHOULD
PUSH TO NEAR A KUIN-KCOU AXIS BETWEEN 11-15Z AND THEN PUSH INTO
THE STL METRO AREA BETWEEN 18-22Z. MODELS HAVE BACKED OFF ON PCPN
POTENTIAL WITH THIS...AS MUCH OF THE UPPER LEVEL SUPPORT MISSES US
TO THE N...LEAVING BEHIND WHAT WILL LIKELY BE A REGION OF SCT SHRA
BEHIND THE CDFNT. MODELS HAVE ALSO BACKED OFF ON THE NON-VFR CIGS
BEHIND THE FRONT...AND THIS MAKES SENSE CONSIDERING HOW THEY ARE
ALSO BACKING OFF ON THE PCPN POTENTIAL...WHICH WOULD BE NEEDED TO
HELP SUSTAIN ANY LO CLOUDS. REMOVED THE HI-END MVFR CIGS IN FAVOR
OF LO-END VFR CIGS FOR THIS ISSUANCE AND WILL NEED TO BE WATCHED
AS LOWER CLOUDS BEHIND CDFNT APPROACH.
SPECIFICS FOR KSTL...VFR AHEAD OF THE CDFNT THRU EARLY AFTERNOON
THURSDAY...TRANSITIONING TO LO-END VFR CIGS BEHIND CDFNT LATER ON
THURSDAY AFTERNOON. PCPN LOOKS SPOTTY AT BEST...AND KEPT VCSH
MENTION FOR NOW BUT WELL BEHIND FROPA.
TES
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1259 PM CDT THU SEP 13 2012
.UPDATE...UPDATED THE FORECAST FOR SKY COVER. HIGH LEVEL CLOUDS
ARE LINGERING A BIT LONGER AND HAVE INDICATED THAT IN THIS
FORECAST.
&&
.AVIATION...18Z KGRI TAF. VFR CONDITIONS ARE ANTICIPATED. WIND
WILL BE LIGHT AND VARIABLE FOR TONIGHT AS SURFACE HIGH PRESSURE
SETTLES IN. HIGH LEVEL CLOUDINESS WILL EVENTUALLY DISSIPATE AS THE
COLD FRONT SLIDES SOUTHEAST AND THE 1030 MB SURFACE HIGH BUILDS
IN. WIND WILL TURN MORE SOUTH SOUTHWEST ON FRIDAY AS THE SURFACE
HIGH SLIPS EAST...BUT WIND WILL REMAIN LIGHT.
&&
PREV DISCUSSION... /ISSUED 408 AM CDT THU SEP 13 2012/
SHORT TERM...THURSDAY THROUGH SATURDAY NIGHT. A RELATIVELY QUITE
PATTERN IS EXPECTED OVER THE NEXT FEW DAYS. PRECIPITATION WILL EXIT
THE OUTLOOK AREA THIS MORNING MORNING...AND THIS WILL BEGIN THE
RELATIVELY QUITE WEATHER AS HIGH PRESSURE SLIDES INTO THE REGION
FROM THE WEST.
THE LATEST RUNS OF BOTH THE NAM AND RUC SUGGEST PRECIPITATION ENDING
ACROSS THE CWA BY MID TO LATE MORNING. FURTHERMORE...THE HRRR ALSO
DEPICTS DRY CONDITIONS BY MID MORNING...SO WENT AHEAD AND SPLIT THE
12Z TO 18Z BLOCK INTO TWO 3 HOUR GROUPS TO ACCOUNT FOR THE
PRECIPITATION ENDING EARLIER THAN PREVIOUSLY FORECAST THIS
MORNING.
WITH LIGHT WINDS AND SUBSIDENCE EXPECTED BEHIND THE EXITING
STRATUS...THERE WILL BE A CHANCE FOR SOME PATCHY FOG EARLY THIS
MORNING...ESPECIALLY NORTHWESTERN PARTS OF THE CWA IF ENOUGH
CLEARING CAN OCCUR BEFORE DAYTIME HEATING BEGINS. CONFIDENCE IS NOT
HIGH ENOUGH TO GO WITH A PRE-FIRST PERIOD AS MOST SPOTS SHOULD BE
ABOVE 3 MILES OF VISIBILITY BY 12Z. NOT GOING TO INCLUDE THE
MENTIONING OF FOG AT THIS TIME BUT THOUGHT IT WAS WORTH MENTIONING.
GOING TO LEAVE IT IN THE GRIDS THOUGH.
THE BIGGEST FORECAST CHALLENGE FOR THE REST OF THE SHORT TERM WILL
BE TEMPERATURES. TEMPERATURES ON FRIDAY WERE NOTICEABLY DIFFERENT
THAN PREVIOUSLY FORECAST...WITH HIGHS 3 TO 4 DEGREES WARMER IN MOST
LOCATIONS. FRIDAY MORNING LOW TEMPERATURES WERE ALSO 3 TO 4 DEGREES
WARMER IN MOST LOCATIONS. THE THOUGHT BEHIND THESE HIGHER
TEMPERATURES IS MOST LIKELY GUIDANCE KEYING ON HIGHER DEWPOINTS FROM
THE RECENT RAINFALL...MOSTLY CLEAR SKIES...AND ADIABATIC COMPRESSION
FROM THE WESTERLY WIND COMPONENT. THE LATEST RUN OF THE NAM12 ALSO
DEPICTS WARM AIR ADVECTION AT 850MB AS OPPOSED TO PREVIOUS RUNS...SO
WENT AHEAD AND RAISED TEMPERATURES A FEW DEGREES TO ACCOUNT FOR THIS
WARMER SETUP. THIS WAS THE BIGGEST CHANGE DURING THIS PERIOD.
OVERALL...NEAR SEASONABLE TEMPERATURES AND DRY CONDITIONS WILL BE
EXPERIENCED BOTH FRIDAY AND SATURDAY.
LONG TERM...SUNDAY THROUGH WEDNESDAY...A BEAUTIFUL END OF THE
WEEKEND APPEARS TO BE ON TAP FOR THE REGION SUNDAY AS SEASONABLY
WARM TEMPERATURES...LIGHT SOUTHERLY WINDS....AND ONLY A FEW HIGH
CLOUDS ARE EXPECTED AHEAD OF AN APPROACHING FRONTAL BOUNDARY. THIS
FRONTAL BOUNDARY WILL BE STEERED ACROSS THE PLAINS SUNDAY NIGHT
THROUGH MONDAY BY AN UPPER LEVEL SHORTWAVE...WITH A MARKEDLY COOLER
AIRMASS EXPECTED IN ITS WAKE AS 850MB TEMPS AREA FORECAST TO DROP
8-10C BEHINDS THIS FRONT. WHILE THERE WILL ALSO BE A CHANCE FOR A
FEW SHOWERS AND EVEN AN ISOLATED THUNDERSTORM LATE SUNDAY NIGHT
THROUGH MONDAY EVENING...THE BEST UPPER LEVEL FORCING APPEARS TO BE
TO DIRECTED THE NORTHEAST OF THE LOCAL AREA IN BOTH LATEST RUNS OF
THE GFS AND EC...AND DECIDED TO TONE DOWN PRECIP CHANCES ACCORDINGLY
OVER THIS TIME PERIOD AS A DEVELOPING UPPER LEVEL RIDGE ACROSS THE
WESTERN STATES APPEARS TO BE SHIFTING THE FOCUS OF THIS SYSTEM AWAY
FROM THE AREA.
THEREAFTER...A GENERALLY NORTHWESTERLY UPPER LEVEL FLOW PATTERN IS
PROGGED TO KEEP MAIN FOCUS OF WEATHER ACROSS THE CENTER OF THE
COUNTRY THROUGH MID WEEK...WITH SEASONABLY COOL TEMPERATURES
EXPECTED AGAIN ON TUESDAY...WITH A BRIEF WARMING TO NEAR OR ABOVE
CLIMO WEDNESDAY...AHEAD OF THE NEXT APPROACHING COLD FRONT. WHILE
MODELS WERE TRYING TO KEY IN ON SOME SMALL CHANCE POPS WITH THIS
NEXT BOUNDARY WED/WED NIGHT...WITH PERSISTENT UPPER LEVEL RIDGE OVER
THE WEST COAST AND CORRESPONDING FOCUS OF STORM TRACK TO OUR
EAST...NOT TO MENTION VERY LIMITED LOW LEVEL MOISTURE...WENT AHEAD
AND REMOVED SMALL CHANCE POPS FROM THE FORECAST WITH THIS SECOND
FRONT MID WEEK IN COORDINATION WITH SURROUNDING OFFICES.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AVIATION/UPDATE...HEINLEIN
SHORT TERM...GUERRERO
LONG TERM...ROSSI
AREA FORECAST DISCUSSION
NWS HASTINGS NE
532 AM CDT THU SEP 13 2012
.AVIATION...12Z KGRI TAF...AFTER SOME PATCHY FOG DISSIPATES THIS
MORNING...VFR CONDITIONS ARE EXPECTED TO PREVAIL AT KGRI FOR THE
REMAINDER OF THE TAF PERIOD. WHILE A FEW SPOTS ACROSS THE REGION
HAVE FALLEN INTO MVFR VSBYS EARLY THIS MORNING...JUST ENOUGH MID
LEVEL STRATUS HAS PERSISTED AT KGRI TO KEEP SIGNIFICANT FOG
FORMATION AWAY FROM THE TERMINAL. AS A RESULT...ONLY MENTIONED
SOME BR WITH VFR VSBYS THROUGH 14Z...WITH CLEARING SKIES AND
IMPROVED VISIBILITIES THEREAFTER. WITH SURFACE HIGH PRESSURE
SINKING ACROSS THE LOCAL AREA TODAY...WINDS DO NO APPEAR TO BE
MUCH OF A CONCERN...WITH WEST TO NORTHWEST WINDS LESS THAN 10KTS
EXPECTED THROUGH THE AFTERNOON HOURS.
&&
.PREV DISCUSSION... /ISSUED 408 AM CDT THU SEP 13 2012/
SHORT TERM...THURSDAY THROUGH SATURDAY NIGHT. A RELATIVELY QUITE
PATTERN IS EXPECTED OVER THE NEXT FEW DAYS. PRECIPITATION WILL EXIT
THE OUTLOOK AREA THIS MORNING MORNING...AND THIS WILL BEGIN THE
RELATIVELY QUITE WEATHER AS HIGH PRESSURE SLIDES INTO THE REGION
FROM THE WEST.
THE LATEST RUNS OF BOTH THE NAM AND RUC SUGGEST PRECIPITATION ENDING
ACROSS THE CWA BY MID TO LATE MORNING. FURTHERMORE...THE HRRR ALSO
DEPICTS DRY CONDITIONS BY MID MORNING...SO WENT AHEAD AND SPLIT THE
12Z TO 18Z BLOCK INTO TWO 3 HOUR GROUPS TO ACCOUNT FOR THE
PRECIPITATION ENDING EARLIER THAN PREVIOUSLY FORECAST THIS
MORNING.
WITH LIGHT WINDS AND SUBSIDENCE EXPECTED BEHIND THE EXITING
STRATUS...THERE WILL BE A CHANCE FOR SOME PATCHY FOG EARLY THIS
MORNING...ESPECIALLY NORTHWESTERN PARTS OF THE CWA IF ENOUGH
CLEARING CAN OCCUR BEFORE DAYTIME HEATING BEGINS. CONFIDENCE IS NOT
HIGH ENOUGH TO GO WITH A PRE-FIRST PERIOD AS MOST SPOTS SHOULD BE
ABOVE 3 MILES OF VISIBILITY BY 12Z. NOT GOING TO INCLUDE THE
MENTIONING OF FOG AT THIS TIME BUT THOUGHT IT WAS WORTH MENTIONING.
GOING TO LEAVE IT IN THE GRIDS THOUGH.
THE BIGGEST FORECAST CHALLENGE FOR THE REST OF THE SHORT TERM WILL
BE TEMPERATURES. TEMPERATURES ON FRIDAY WERE NOTICEABLY DIFFERENT
THAN PREVIOUSLY FORECAST...WITH HIGHS 3 TO 4 DEGREES WARMER IN MOST
LOCATIONS. FRIDAY MORNING LOW TEMPERATURES WERE ALSO 3 TO 4 DEGREES
WARMER IN MOST LOCATIONS. THE THOUGHT BEHIND THESE HIGHER
TEMPERATURES IS MOST LIKELY GUIDANCE KEYING ON HIGHER DEWPOINTS FROM
THE RECENT RAINFALL...MOSTLY CLEAR SKIES...AND ADIABATIC COMPRESSION
FROM THE WESTERLY WIND COMPONENT. THE LATEST RUN OF THE NAM12 ALSO
DEPICTS WARM AIR ADVECTION AT 850MB AS OPPOSED TO PREVIOUS RUNS...SO
WENT AHEAD AND RAISED TEMPERATURES A FEW DEGREES TO ACCOUNT FOR THIS
WARMER SETUP. THIS WAS THE BIGGEST CHANGE DURING THIS PERIOD.
OVERALL...NEAR SEASONABLE TEMPERATURES AND DRY CONDITIONS WILL BE
EXPERIENCED BOTH FRIDAY AND SATURDAY.
LONG TERM...SUNDAY THROUGH WEDNESDAY...A BEAUTIFUL END OF THE
WEEKEND APPEARS TO BE ON TAP FOR THE REGION SUNDAY AS SEASONABLY
WARM TEMPERATURES...LIGHT SOUTHERLY WINDS....AND ONLY A FEW HIGH
CLOUDS ARE EXPECTED AHEAD OF AN APPROACHING FRONTAL BOUNDARY. THIS
FRONTAL BOUNDARY WILL BE STEERED ACROSS THE PLAINS SUNDAY NIGHT
THROUGH MONDAY BY AN UPPER LEVEL SHORTWAVE...WITH A MARKEDLY COOLER
AIRMASS EXPECTED IN ITS WAKE AS 850MB TEMPS AREA FORECAST TO DROP
8-10C BEHINDS THIS FRONT. WHILE THERE WILL ALSO BE A CHANCE FOR A
FEW SHOWERS AND EVEN AN ISOLATED THUNDERSTORM LATE SUNDAY NIGHT
THROUGH MONDAY EVENING...THE BEST UPPER LEVEL FORCING APPEARS TO BE
TO DIRECTED THE NORTHEAST OF THE LOCAL AREA IN BOTH LATEST RUNS OF
THE GFS AND EC...AND DECIDED TO TONE DOWN PRECIP CHANCES ACCORDINGLY
OVER THIS TIME PERIOD AS A DEVELOPING UPPER LEVEL RIDGE ACROSS THE
WESTERN STATES APPEARS TO BE SHIFTING THE FOCUS OF THIS SYSTEM AWAY
FROM THE AREA.
THEREAFTER...A GENERALLY NORTHWESTERLY UPPER LEVEL FLOW PATTERN IS
PROGGED TO KEEP MAIN FOCUS OF WEATHER ACROSS THE CENTER OF THE
COUNTRY THROUGH MID WEEK...WITH SEASONABLY COOL TEMPERATURES
EXPECTED AGAIN ON TUESDAY...WITH A BRIEF WARMING TO NEAR OR ABOVE
CLIMO WEDNESDAY...AHEAD OF THE NEXT APPROACHING COLD FRONT. WHILE
MODELS WERE TRYING TO KEY IN ON SOME SMALL CHANCE POPS WITH THIS
NEXT BOUNDARY WED/WED NIGHT...WITH PERSISTENT UPPER LEVEL RIDGE OVER
THE WEST COAST AND CORRESPONDING FOCUS OF STORM TRACK TO OUR
EAST...NOT TO MENTION VERY LIMITED LOW LEVEL MOISTURE...WENT AHEAD
AND REMOVED SMALL CHANCE POPS FROM THE FORECAST WITH THIS SECOND
FRONT MID WEEK IN COORDINATION WITH SURROUNDING OFFICES.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...GUERRERO
LONG TERM/AVIATION...ROSSI
AREA FORECAST DISCUSSION
NWS HASTINGS NE
408 AM CDT THU SEP 13 2012
.SHORT TERM...THURSDAY THROUGH SATURDAY NIGHT. A RELATIVELY QUITE
PATTERN IS EXPECTED OVER THE NEXT FEW DAYS. PRECIPITATION WILL EXIT
THE OUTLOOK AREA THIS MORNING MORNING...AND THIS WILL BEGIN THE
RELATIVELY QUITE WEATHER AS HIGH PRESSURE SLIDES INTO THE REGION
FROM THE WEST.
THE LATEST RUNS OF BOTH THE NAM AND RUC SUGGEST PRECIPITATION ENDING
ACROSS THE CWA BY MID TO LATE MORNING. FURTHERMORE...THE HRRR ALSO
DEPICTS DRY CONDITIONS BY MID MORNING...SO WENT AHEAD AND SPLIT THE
12Z TO 18Z BLOCK INTO TWO 3 HOUR GROUPS TO ACCOUNT FOR THE
PRECIPITATION ENDING EARLIER THAN PREVIOUSLY FORECAST THIS
MORNING.
WITH LIGHT WINDS AND SUBSIDENCE EXPECTED BEHIND THE EXITING
STRATUS...THERE WILL BE A CHANCE FOR SOME PATCHY FOG EARLY THIS
MORNING...ESPECIALLY NORTHWESTERN PARTS OF THE CWA IF ENOUGH
CLEARING CAN OCCUR BEFORE DAYTIME HEATING BEGINS. CONFIDENCE IS NOT
HIGH ENOUGH TO GO WITH A PRE-FIRST PERIOD AS MOST SPOTS SHOULD BE
ABOVE 3 MILES OF VISIBILITY BY 12Z. NOT GOING TO INCLUDE THE
MENTIONING OF FOG AT THIS TIME BUT THOUGHT IT WAS WORTH MENTIONING.
GOING TO LEAVE IT IN THE GRIDS THOUGH.
THE BIGGEST FORECAST CHALLENGE FOR THE REST OF THE SHORT TERM WILL
BE TEMPERATURES. TEMPERATURES ON FRIDAY WERE NOTICEABLY DIFFERENT
THAN PREVIOUSLY FORECAST...WITH HIGHS 3 TO 4 DEGREES WARMER IN MOST
LOCATIONS. FRIDAY MORNING LOW TEMPERATURES WERE ALSO 3 TO 4 DEGREES
WARMER IN MOST LOCATIONS. THE THOUGHT BEHIND THESE HIGHER
TEMPERATURES IS MOST LIKELY GUIDANCE KEYING ON HIGHER DEWPOINTS FROM
THE RECENT RAINFALL...MOSTLY CLEAR SKIES...AND ADIABATIC COMPRESSION
FROM THE WESTERLY WIND COMPONENT. THE LATEST RUN OF THE NAM12 ALSO
DEPICTS WARM AIR ADVECTION AT 850MB AS OPPOSED TO PREVIOUS RUNS...SO
WENT AHEAD AND RAISED TEMPERATURES A FEW DEGREES TO ACCOUNT FOR THIS
WARMER SETUP. THIS WAS THE BIGGEST CHANGE DURING THIS PERIOD.
OVERALL...NEAR SEASONABLE TEMPERATURES AND DRY CONDITIONS WILL BE
EXPERIENCED BOTH FRIDAY AND SATURDAY.
.LONG TERM...SUNDAY THROUGH WEDNESDAY...A BEAUTIFUL END OF THE
WEEKEND APPEARS TO BE ON TAP FOR THE REGION SUNDAY AS SEASONABLY
WARM TEMPERATURES...LIGHT SOUTHERLY WINDS....AND ONLY A FEW HIGH
CLOUDS ARE EXPECTED AHEAD OF AN APPROACHING FRONTAL BOUNDARY. THIS
FRONTAL BOUNDARY WILL BE STEERED ACROSS THE PLAINS SUNDAY NIGHT
THROUGH MONDAY BY AN UPPER LEVEL SHORTWAVE...WITH A MARKEDLY COOLER
AIRMASS EXPECTED IN ITS WAKE AS 850MB TEMPS AREA FORECAST TO DROP
8-10C BEHINDS THIS FRONT. WHILE THERE WILL ALSO BE A CHANCE FOR A
FEW SHOWERS AND EVEN AN ISOLATED THUNDERSTORM LATE SUNDAY NIGHT
THROUGH MONDAY EVENING...THE BEST UPPER LEVEL FORCING APPEARS TO BE
TO DIRECTED THE NORTHEAST OF THE LOCAL AREA IN BOTH LATEST RUNS OF
THE GFS AND EC...AND DECIDED TO TONE DOWN PRECIP CHANCES ACCORDINGLY
OVER THIS TIME PERIOD AS A DEVELOPING UPPER LEVEL RIDGE ACROSS THE
WESTERN STATES APPEARS TO BE SHIFTING THE FOCUS OF THIS SYSTEM AWAY
FROM THE AREA.
THEREAFTER...A GENERALLY NORTHWESTERLY UPPER LEVEL FLOW PATTERN IS
PROGGED TO KEEP MAIN FOCUS OF WEATHER ACROSS THE CENTER OF THE
COUNTRY THROUGH MID WEEK...WITH SEASONABLY COOL TEMPERATURES
EXPECTED AGAIN ON TUESDAY...WITH A BRIEF WARMING TO NEAR OR ABOVE
CLIMO WEDNESDAY...AHEAD OF THE NEXT APPROACHING COLD FRONT. WHILE
MODELS WERE TRYING TO KEY IN ON SOME SMALL CHANCE POPS WITH THIS
NEXT BOUNDARY WED/WED NIGHT...WITH PERSISTENT UPPER LEVEL RIDGE OVER
THE WEST COAST AND CORRESPONDING FOCUS OF STORM TRACK TO OUR
EAST...NOT TO MENTION VERY LIMITED LOW LEVEL MOISTURE...WENT AHEAD
AND REMOVED SMALL CHANCE POPS FROM THE FORECAST WITH THIS SECOND
FRONT MID WEEK IN COORDINATION WITH SURROUNDING OFFICES.
&&
.PREV DISCUSSION... /ISSUED 1229 AM CDT THU SEP 13 2012/
AVIATION...06Z KGRI TAF...AT 05Z...THE BACK EDGE OF THE
PRECIPITATION BAND WAS APPROACHING KGRI IN LATEST RADAR IMAGES.
AS A RESULT...EXPECT MORE STEADY PRECIPITATION TO END AT THE
TERMINAL PRIOR TO 06Z...WITH SHRAS CONTINUING IN THE VICINITY OF
THE TERMINAL FOR THE NEXT COUPLE OF HOURS. ONCE THE PRECIPITATION
BEGINS TO WANE AND SOME BREAKS IN MID LEVEL CLOUD DECK ARE
REALIZED...EXPECT CIGS TO DROP SIGNIFICANTLY AS LOW LEVEL STRATUS
AND SOME PATCHY FOG BEGINS TO FORM AND SPREAD ACROSS THE TERMINAL.
WHILE GUIDANCE IS NOT IN COMPLETE AGREEMENT WITH THE DEVELOPMENT
OF LOW VISIBILITIES WITH PATCHY FOG THIS MORNING...FAIRLY GOOD
AGREEMENT DEVELOPING THE LOW CIGS...SO WENT AHEAD AND INTRODUCED
SOME LIFR CIGS FROM 13/10Z-13/14Z...KEEPING VISIBILITIES IN PATCHY
FOG IN THE MVFR RANGE. ONCE THE SUN RISES AND STRATUS BEGINS TO
BREAK...EXPECT A RETURN TO VFR CONDITIONS BY 13/14Z...WITH LIGHT
WEST TO NORTHWESTERLY WINDS THROUGH THE AFTERNOON HOURS AS AN AREA
OF SURFACE HIGH PRESSURE SINKS SOUTHWARD ACROSS THE REGION.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...GUERRERO
LONG TERM/AVIATION...ROSSI
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1228 AM CDT THU SEP 13 2012
.AVIATION...
CLEARING SKIES OVERNIGHT WITH LIGHT WINDS LESS THAN 10 MILES AN HOUR
ARE EXPECTED OVER WESTERN NEBRASKA AS SURFACE HIGH PRESSURE BUILDS
IN. NO CLEAR FOG SIGNAL SO HAVE LEFT MENTION OUT OF TAFS AT BOTH
KVTN AND KLBF.
&&
.PREV DISCUSSION... /ISSUED 810 PM CDT WED SEP 12 2012/
UPDATE...
SHOWERS HAVE MOVED JUST EAST OF THE FORECAST AREA. HAVE ENDED
PRECIPITATION AND LOWERED POPS. TEMPERATURE FORECAST LOOKS TO BE
ON TRACK IF SKIES CLEAR LATER.
&&
.PREV DISCUSSION... /ISSUED 647 PM CDT WED SEP 12 2012/
AVIATION...
SOME ISOLATED SHOWERS OVER THE NEBRASKA PANHANDLE THIS EVENING
WILL DISSIPATE WITH THE SETTING OF THE SUN. THE MAIN AREA OF
PRECIPITATION IS MOVING INTO CENTRAL NEBRASKA AND IS GENERALLY
EAST OF A KONL TO KIML LINE AND MOVING SLOWLY EAST. MVFR CEILINGS
OVER SOUTHWEST NEBRASKA WILL RISE INTO VFR CATEGORIES AFTER 1303Z.
SKIES CLEARING OUT OVER WESTERN NEBRASKA AFTER 1306Z WITH LIGHT
WINDS AND CLEAR SKIES THURSDAY UNDER SURFACE HIGH PRESSURE.
PREV DISCUSSION... /ISSUED 327 PM CDT WED SEP 12 2012/
DISCUSSION...
UPPER LEVEL TROF SHOULD EXIT THE FCST AREA BY 03Z-06Z WITH 1028 MB
HIGH PRESSURE BUILDING IN OVERNIGHT. RECENT RAINS AND CALM
BOUNDARY LAYER WINDS IN THE WETTER AREAS MIGHT BE SUFFICIENT FOR
PATCHY FOG. LIMITING FACTOR MIGHT BE STRONG SUBSIDENCE WHICH WOULD
NEGATE MOISTURE POOLING.
GIVEN HIGHS IN THE 50S AND 60S THIS AFTERNOON FROST OR FREEZE
POTENTIAL TONIGHT COULD BECOME VERY HIGH IF SKIES CLEAR AS RAPIDLY
AS SOME EARLIER SOLNS OF THE RAP MODEL SHOWED. THE LATEST RAP IS
TRAPPING MOISTURE IN THE BOUNDARY LAYER BENEATH THE SFC HIGH AT
06Z WHICH IS A FOG SIGNATURE. FOR NOW SOME OF THE COOLER GUIDANCE
SUGGESTED PATCHY FROST ACROSS SHERIDAN COUNTY...NOTHING MORE AND
PATCHY FOG IS IN PLACE ACROSS THE WETTER AREAS.
HIGH PRESSURE AND CLEAR SKIES WILL DRIFT ACROSS THE FCST AREA
THURSDAY WITH HIGHS IN THE MID 70S.
FRIDAY THROUGH SUNDAY...ANOTHER SLOWLY EVOLVING NRN PLAINS LOW
PRESSURE SYSTEM WILL DROP INTO WCNTL NEB BY SUNDAY AFTERNOON. THE
TIMING OF THE COLD FRONTAL PASSAGE SUNDAY AFTERNOON SUGGESTS NO
TORCH FEST FOR THE FORECAST AREA AT THIS TIME. SATURDAY MIGHT
ACTUALLY BE THE WARMEST DAY WITH 90F MAYBE ACROSS NORTHWEST
NEB...80S ELSEWHERE. UPPER 70S MODERATING TO THE MID 80S SATURDAY
AND SUNDAY WOULD APPEAR TO BE THE OPERATIVE MODE AT THIS TIME.
WE WOULD EXPECT TO SEE 580DM 10-5MB THICKNESSES FOR HIGHS NEAR OR
ABOVE 90F BUT WE ARE STILL OPERATING IN THE LOW 570S.
MONDAY THROUGH WEDNESDAY...A COLD FRONT WILL SLICE THROUGH THE FCST
AREA SUNDAY AND SUNDAY NIGHT. THERE MAY BE SUFFICIENT RETURN
MOISTURE FOR ISOLD TSTMS SUNDAY NIGHT AND ISOLATED SHRA MONDAY.
TEMPS MONDAY STAY IN THE 60S AS A STRONG CANADIAN HIGH DROPS
THROUGH THE HIGH PLAINS. THE PACIFIC NORTH AMERICAN AMPLIFICATION
WILL BE IN FULL SWING THROUGH WEDNESDAY. MODEL CONSENSUS SUGGESTS
THE RIDGE AXIS LINING UP ACROSS BRITISH COLUMBIA AND THIS WOULD
DIVERT THE COLDEST AIR INTO THE UPPER MIDWEST. THE GEM POSITIONS
THE AXIS FARTHER WEST...IS MORE AMPLIFIED AND TRAPS SOME DYNAMICS
ACROSS WY PRODUCING SNOW.
SFC HIGH PRESSURE WILL MOVE QUICKLY SOUTH AND EAST TUESDAY WITH
LOW PRESSURE AND RETURN FLOW DEVELOPING WEDNESDAY. OTHER THAN THE
RAIN TONIGHT AND ISOLATED CHANCES LATE SUNDAY AND MONDAY THE
FORECAST IS DRY.
FIRE WEATHER...
DID GET RAIN TODAY IN PARTS OF THE FORECAST AREA...BUT MOST
LOCATIONS DID NOT RECEIVE ENOUGH TO WET FUELS TO THE POINT OF BEING
NOT CRITICALLY DRY. ALSO...WHAT WETTING DID OCCUR...WITH SEE THE
OPPORTUNITY TO DRY OUT ON THURSDAY WITH MOSTLY SUNNY SKIES AND HIGHS
IN THE 70S.
A WARMING TREND IS EXPECTED FOR THE WEEKEND...WITH HIGHS IN THE 80S
/AND POSSIBLY A FEW 90S/ FOR SATURDAY AND SUNDAY. DEWPOINTS SHOULD
STAY FAIRLY LOW...IN THE 30S AND LOW 40S THROUGH THIS PERIOD SO
AFTERNOON RELATIVE HUMIDITY WILL DROP TO 15 TO 20 PERCENT ACROSS
PORTIONS OF THE AREA THROUGH FRIDAY...SATURDAY...AND SUNDAY. AM NOT
LOOKING AT PARTICULARLY STRONG WINDS THESE DAYS...BUT COULD GET
GUSTS TO THE 20 TO 25 MPH RANGE EACH DAY.
ANOTHER STRONG SYSTEM THEN LOOKS TO MOVE THROUGH SUNDAY NIGHT...WITH
A WIND SHIFT TO THE NORTH AND MUCH COOLER TEMPERATURES FOR MONDAY.
SUNDAY NIGHT AND MONDAY WILL BE THE NEXT CHANCE FOR RAIN...ALTHOUGH
RAINFALL AMOUNTS DO NOT LOOK TOO IMPRESSIVE AT THIS POINT.
THE WEATHER LOOKS TO BE MARGINAL AT BEST FOR CRITICAL FIRE WEATHER
CONDITIONS OVER THE NEXT WEEK. HOWEVER...WITH THE CONTINUED DRYNESS
OF FUELS...EVEN MARGINAL FIRE WEATHER CONDITIONS CAN...AND HAS
CAUSED EXTREME FIRE BEHAVIOR. THEREFORE...WILL BE CLOSELY MONITORING
THE FORECAST FOR FRIDAY THROUGH SUNDAY FOR THE NEED FOR FIRE WEATHER
HEADLINES.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/EXTENDED...POWER/CDC
AVIATION...POWER
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
130 AM EDT THU SEP 13 2012
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO DOMINATE THE WEATHER THROUGH THE
END OF THE WORK WEEK. A WEAK AND MOISTURE STARVED COLD FRONT WILL
MOVE ACROSS THE AREA EARLY SATURDAY...THEN DISSIPATE ALTOGETHER
DURING SUNDAY. HIGH PRESSURE RIDGING FROM THE NE STATES WILL
DOMINATE THE WEATHER THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1035 PM WEDNESDAY...CENTER OF SURFACE HIGH PRESSURE TO TRACK
OFFSHORE FROM THE MID-ATLANTIC AND NE STATES OVERNIGHT INTO
THURSDAY. LATEST SAT IMAGERY INDICATES THIN TO OCCASIONALLY OPAQUE
CIRRUS TO OVERSPREAD THE FA FROM THE SW DURING THE OVERNIGHT.
AT THE SAME TIME...EXTRAPOLATION OF THE SC DECK NEARSHORE AND
OFFSHORE FROM THE CAROLINAS USING THE LATEST IR SAT IMAGERY AS THE
INITIAL TIME...WILL MOVE PARTIALLY ONSHORE SOUTH OF THE SC/NC BORDER.
LATEST HRRR MODEL OUTPUT ILLUSTRATES POSSIBLE PCPN ACCOMPANYING THE
SC DECK AS IT REACHES AND MOVES ACROSS THE COASTAL WATERS SOUTH OF
THE NC-SC BORDER. AT THIS POINT...THE DRY AIR ACROSS LAND LOCATIONS
WITHIN THE FA...AND THE SUBSIDENCE ALOFT SHOULD HELP TO PREVENT THE
PCPN FROM MOVING ONSHORE AND INLAND. CURRENT MIN FORECAST LOOKS ON
CUE AND SEE NO REASON TO DETOUR FROM PREVIOUS THINKING.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...HIGH PRESSURE RIDGING BACK FROM CENTER
SHIFTING FURTHER EAST INTO THE ATLANTIC OFF THE NEW ENGLAND COAST ON
THURS INTO EARLY FRI. THIS WILL CONTINUE TO PRODUCE AN E-NE ON SHORE
FLOW. BY FRIDAY...THE HIGH WEAKENS AS IT GETS SQUEEZED OUT BY A
MOISTURE STARVED COLD FRONT MOVING INTO THE CAROLINAS FROM THE
NORTHWEST. THE ON SHORE FLOW MAY PRODUCE SOME PATCHES OF CLOUDS
MOVING IN FROM THE WATERS OVERNIGHT THURS. THE MODELS SHOW PCP WATER
DOWN LESS THAN AN INCH THROUGH THURS AFTN BUT THEN AN INCREASE WITH
THIS ON SHORE FLOW AND APPROACHING COLD FRONT LATE FRI INTO SAT.
THE MID TO UPPER RIDGE SLIPS OFF THE EAST COAST BY FRIDAY AS
TROUGH DEEPENS DOWN THROUGH THE APPALACHIANS. THIS WILL PRODUCE A
RETURN FLOW VERY BRIEFLY ON FRI. BOTH THE NAM AND GFS SHOW VERY
LITTLE UPPER LEVEL FORCING WITH THIS SYSTEM WITH BEST ENERGY
COMING IN THROUGH THE MID LEVELS AS SHORTWAVE CROSSES THE AREA
THROUGH FRI AFTN INTO THE EVENING. DURING THIS TIME SHOULD SEE
INCREASED CLDS IN E-NE FLOW AT LOW LEVELS AND PASSING UPPER LEVEL
CLOUDS. THE MOISTURE PROFILES SHOW AN INCREASE IN RH UP GREATER
THAN 90 PERCENT ABOVE H5 BUT VERY DRY AIR REMAINING IN THE MID
LEVELS. THEREFORE EXPECT LIMITED...IF ANY CHC OF SHALLOW PASSING
SHWRS.
BY END OF PERIOD A DEEP NW FLOW WILL SET UP IN THE MID LEVELS AS H5
TROUGH PUSHES FARTHER EAST. THE MAIN EFFECT OF THE FRONT WILL BE
INCREASED CLOUDS FRI AND A REINFORCEMENT AND SHIFT TO MORE
NORTHERLY WINDS FRI INTO SAT WITH ONLY A SLIGHT CHC OF PCP FRI.
TEMPERATURES NEAR CLIMO THROUGH THE PERIOD...MID 80S AND MID 60S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 PM WEDNESDAY...SPLIT FLOW PATTERN DEVELOPS AT THE START OF
THE PERIOD AS A NORTHERN STREAM TROUGH DRIVES A COLD FRONT TOWARDS
THE EASTERN CAROLINAS. THIS FRONT DIVES INTO A RELATIVELY DRY AIR
MASS...AND MID/UPPER FORCING ASSOCIATED WITH IT IS QUITE WEAK.
THEREFORE...EXPECT VERY LITTLE IN THE WAY OF PRECIP WITH ITS
PASSAGE...AND INSTEAD WILL JUST SEE AN INCREASE IN CLOUD COVER. AS
WINDS TURN MORE E/NE BEHIND THE FRONT...THIS ADVECTS ATLANTIC
MOISTURE INTO THE COLUMN. INHERITED FORECAST SHOWS SCHC POP FOR THE
WKND...AND WILL LEAVE THIS UNCHANGED. HOWEVER...FORECAST PROFILES
SHOW MUCH DRIER AIR ABOVE 750MB OR SO THAN WAS PREDICTED YESTERDAY
SINCE THE ATLANTIC FETCH REMAINS CONFINED TO THE LOWER PART OF THE
COLUMN. IF THIS TREND CONTINUES...MAY HAVE TO REMOVE ALL MENTION OF
TSTMS...ESPECIALLY ON SATURDAY. TEMPS WILL BE RIGHT AROUND CLIMO
DURING THE WKND.
SOUTHERN STREAM VORT ALONG THE GULF COAST WILL THEN ROTATE NORTHEAST
ON LEE SIDE OF DEVELOPING LONGWAVE TROUGH ACROSS THE PLAINS. AT THE
SAME TIME...DEEP SE FLOW DEVELOPS AND IT APPEARS THAT LATE MON/TUE
WILL BE THE BEST CHANCE FOR RAINFALL DURING THE EXTENDED. A SURFACE
REFLECTION TO THIS MID-LEVEL IMPULSE MAY WORK JUST WEST OF THE
CWA...WHICH ALLOWS FOR THE WARM FRONT AND ITS ASSOCIATED LIFT TO
CROSS US LATE MONDAY. STILL DIFFERENCES IN STRENGTH OF THIS FEATURE
FROM THE MODELS...SO WILL KEEP LOW-CHC POP FOR NOW. WILL NOTE THAT
IF THE ECMWF IS CORRECT THIS COULD END UP BEING A ROBUST RAINFALL
EVENT...BUT WITH GUIDANCE FLIPPING IN ITS AMPLIFICATION OF CENTRAL
5H TROUGH...WILL KEEP ONLY LIMITED QPF FOR NOW. BY WEDNESDAY THIS
FEATURE WILL BE WELL NE OF THE AREA AND DRYING WILL OCCUR.
TEMPS FOR THE FIRST HALF OF NEXT WEEK WILL BE AROUND CLIMO FOR
HIGHS...BUT LOWS WILL BE A FEW DEGREES ABOVE EACH NIGHT DUE TO
INCREASED SOUTHERLY FLOW AND CLOUD COVER.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 06Z...EXPECT VFR THROUGH THE VALID PERIOD...WITH EXCEPTION OF
POTENTIAL FOR SHORT-LIVED MVFR DUE TO FOG AT KLBT BEFORE SUNRISE.
LIGHT NORTHEAST WINDS WILL CONTINUE OVERNIGHT WITH A FEW LINGERING
LOW TO HIGH LEVEL CLOUDS ACROSS THE AREA. GIVEN GUIDANCE AND FCST
SOUNDINGS...CANNOT RULE OUT FOG AT KLBT BEFORE DAYBREAK...THOUGH
CONFIDENCE IS LOW. ATTM...HAVE OPTED TO KEEP TEMPO IN CURRENT FCST.
AFTER SUNRISE...EAST-NORTHEAST WINDS WILL INCREASE TO AOB 10 KTS FOR
THE REMAINDER OF THE DAY. INCREASING MOISTURE...ESPECIALLY ALONG THE
COAST...WILL ALLOW FOR LOW CLOUDS TO DEVELOP EARLY ON IN THE DAY.
COVERAGE WILL BE FEW/SCT...THOUGH DO NOT ANTICIPATE ANY RESTRICTIONS
TO ARISE. INTO THE EVENING HOURS...CLOUD COVERAGE WILL DECREASE AND
WINDS WILL BECOME LIGHT.
THE EXTENDED OUTLOOK THROUGH MONDAY...POTENTIAL FOR BRIEF REDUCED
VSBYS IN BR AT FOG PRONE TERMINALS KLBT/KFLO IN THE PRE-DAWN HOURS
THROUGH SUNDAY. OTHERWISE EXPECT VFR...WITH A SLIGHT CHANCE OF
SHOWERS SUNDAY AND A BETTER CHANCE ON MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1040 PM WEDNESDAY...CENTER OF HIGH PRESSURE WILL MOVE
OFFSHORE FROM THE NE STATES...BUT CONTINUE TO RIDGE BACK ACROSS THE
LOCAL WATERS OVERNIGHT. THIS PRESSURE PATTERN WILL PRODUCE A NE TO
ENE WIND DIRECTION OVERNIGHT. THE SFC PG WILL SLIGHTLY TIGHTEN AS A
RESULT OF THE HIGHS CENTER MOVING FURTHER AWAY FROM THE ILM
WATERS...AND THUS PRODUCE 15 TO OCCASIONALLY 20 KT WIND SPEEDS. AS
FOR SEAS...2 TO 4 FT NORTH OF CAPE FEAR...3 TO 5 FT FROM CAPE FEAR
SOUTHWARD. SEAS WILL PRIMARILY BE A SUMMATION OF 2 TO 4 FT WIND
DRIVEN WAVES AT 4 TO 5 SECOND PERIODS...AND A 1 TO 2 FT RESIDUAL
EASTERLY SWELL AT 9-12 SECOND PERIODS.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...HIGH PRESSURE RIDGING DOWN FROM THE
NORTHEAST WILL GET SQUEEZED OUT AS COLD FRONT APPROACHES FROM THE
NORTHWEST LATE FRIDAY INTO SATURDAY. OVERALL WILL MAINTAIN A
DECENT E-NE FLOW THROUGH THURS WITH A SLIGHT BACKING TO THE NORTH
AS FRONT DRAWS CLOSER LATE FRI. PINCHED GRADIENT INITIALLY WILL
KEEP WINDS AROUND 15 KTS BUT AS GRADIENT RELAXES AND BACKS THROUGH
FRI EXPECT NE WINDS 10 TO 15 KTS AND DROPPING UNDER 10 KT FRI
NIGHT. SEAS WILL SUBSIDE FROM 3 TO 4 FT DOWN TO 2 TO 3 FT BY LATE
FRI AS WINDS DIMINISH. MAY SEE A FEW 5 FOOTERS IN OUTER WATERS EARLY
THURS.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 300 PM WEDNESDAY...COLD FRONT WILL BE PUSHING SOUTH/OFFSHORE
AT THE START OF THE PERIOD. A WEAK SURGE WILL EXIST BEHIND THIS
FRONT...AND NE WINDS OF AROUND 10 KTS ARE EXPECTED THROUGH MUCH OF
THE WKND BEFORE SLOWLY VEERING TO THE SOUTH ON MONDAY...STILL
AROUND 10 KTS. THE LONG DURATION NE WIND ACROSS A LONG FETCH DOWN
THE EAST COAST WILL CREATE A 3-4 FT/8SEC NE SWELL WHICH COMBINES
WITH A 1-2 FT NE WIND WAVE TO PRODUCE 2-4 FT SEAS...WITH SOME 5
FOOTERS POSSIBLE NEAR THE 20NM BOUNDARY. AS WINDS TURN TO THE SOUTH
MONDAY...SEAS WILL FALL...BECOMING 2-3 FT ACROSS THE WATERS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DCH
NEAR TERM...DCH
SHORT TERM...RGZ
LONG TERM...JDW
AVIATION...SGL/RJD
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
255 AM CDT THU SEP 13 2012
.DISCUSSION.../ISSUED AT 255 AM CDT/
LINGERING RAIN BAND IS ABOUT OUT OF SOUTHEAST CORNER OF AREA AND MID
AND HIGH CLOUDS WILL CONTINUE TO STEADILY DECREASE. THE HIGH CLOUDS
HAVE OBVIOUSLY BECOME THIN ENOUGH TO ALLOW FOR ENOUGH COOLING FOR
THE PATCHY FOG WE HAVE BEEN GOING FOR AS IT IS ALREADY DEVELOPING IN
A FEW PLACES. PLAN ON KEEPING INTO THE EARLY MORNING AND MAY ADJUST
AREA AT THE LAST MINUTE. THIS ADJUSTMENT COULD INCLUDE MAKING THE
FOG MORE THAN PATCHY AND SOME DENSE FOG NOT OUT OF THE QUESTION...
BUT THE DENSE STUFF SHOULD BE ISOLATED. COMING OUT OF THE FOG...WE
WILL GO INTO A CLEAR PERIOD WITH A SLOW WARMING TREND WHICH SHOULD
LAST THROUGH MOST OF THE COMING WEEKEND. LIGHT WINDS AT FIRST WILL
GIVE WAY TO A DEVELOPING SOUTHERLY FLOW. THE COMBINATION OF
WARMING...DRYING...AND INCREASING WINDS WILL LIKELY PRODUCE A
RETURN TO ELEVATED FIRE DANGER OVER THE WEEKEND AND WILL MENTION IN
HAZARDOUS WX OUTLOOK. GUIDANCE TEMPERATURES NEXT FEW DAYS LOOK
GENERALLY REASONABLE WITH A LIKELIHOOD OF A LITTLE GREATER DIURNAL
RANGE THAN WHAT GUIDANCE IS SHOWING IN THIS PATTERN.
LATE SUNDAY AND SUNDAY NIGHT COLD FRONT WILL COOL THE WX DOWN FOR
NEXT WEEK...THOUGH GUIDANCE WARMS IT UP SLIGHTLY AFTER INITIAL COOL
DOWN. GUIDANCE TEMPERATURES AGAIN LOOK RATHER MODERATE AND WILL GO
WITH THEM AS MODELS DIFFER ON THE STRENGTH OF COOL AIR INTRUSION.
THE GFS WOULD SUGGEST A DECENT FROST POTENTIAL LATE MONDAY NIGHT AND
EARLY TUESDAY MORNING.
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
VFR CONDITIONS EXPECTED TO PREVAIL THROUGH THE TAF PERIOD. WHERE
LINGERING LOW LEVEL MOISTURE REMAINS AND SKIES CLEAR...COULD SEE
PATCHY RADIATION FOG DEVELOP. HURON RECEIVED LIMITED AMOUNTS OF
RAIN...SO ANY FOG THERE SHOULD BE QUITE LIMITED. FURTHER TO THE
SOUTH AND EAST...CONTINUED MENTION OF FOG IN KFSD TERMINAL...BUT
LEFT MENTION OUT OF KSUX AS CONFIDENCE IS LOW THAT SKIES WILL CLEAR
ENOUGH TO RESULT IN FOG. HRRR DEVELOPS PATCHY DENSE FOG AROUND SIOUX
FALLS. WITH SCATTERED CLOUD COVER...CONFIDENCE IS IFFY WITH
FOG...BUT THE EARLIER THE CLEARING OCCURS...THE BETTER POTENTIAL
THERE IS FOR LOCALLY DENSE FOG.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
828 PM CDT FRI SEP 14 2012
.UPDATE...
LATEST RADAR IMAGES SHOW A LARGE AREA OF RAIN OVER CENTRAL
ARKANSAS. MOST MODELS INDICATE THE RAIN SHOULD STAY WEST OF THE
CWA HOWEVER LOOKING AT KNQA RADAR THE FRONT EDGE OF THE RAIN CONTINUES
TO PUSH EAST. HRRR MODEL IS THE ONLY ONE THAT PUSHES THE RAIN INTO
THE CWA INCLUDING MEMPHIS BY 10-12Z. WILL UPDATE TO RAISE POPS
TO 50 AROSS EASTERN ARKANSAS. WILL ALSO BUMP UP LOWS ACROSS THE
WEST DUE TO CLOUD COVER. UPDATE WILL BE OUT SHORTLY.
KRM
&&
.DISCUSSION... /ISSUED 305 PM CDT FRI SEP 14 2012/
SKIES ARE PARTLY TO MOSTLY CLOUDY ACROSS MUCH OF THE FORECAST
AREA THIS AFTERNOON WITH TEMPERATURES IN THE UPPER 70S TO UPPER
80S. THE COLD FRONT EXTENDS FROM NORTHWEST PENNSYLVANIA THROUGH
WEST TENNESSEE AND INTO SOUTHEAST TEXAS. SOME SCATTERED SHOWERS
AND ISOLATED THUNDERSTORMS CONTINUE TO MOVE ACROSS PORTIONS OF THE
FORECAST AREA NEAR THE FRONT. MOST OF THE ACTIVITY IN WEST
TENNESSEE IS MOVING SOUTHEAST WHILE THE ACTIVITY IN EAST ARKANSAS
IS MOVING NORTH.
AS THE FRONT CONTINUES TO PUSH EAST TONIGHT MORE SHOWERS AND A FEW
THUNDERSTORMS WILL BE POSSIBLE TONIGHT. THE FRONT SHOULD MOVE OUT
OF THE FORECAST AREA BY SATURDAY MORNING. HOWEVER AN UPPER LEVEL
DISTURBANCES WILL MOVE THROUGH THE REGION ON SATURDAY BRINGING
SCATTERED SHOWERS AND POSSIBLY A THUNDERSTORM OR TWO WITH IT. AN
UPPER LEVEL TROUGH WILL MOVE THROUGH THE REGION SUNDAY AND MONDAY
BRINGING A BETTER CHANCE OF RAIN. TEMPERATURES THIS WEEKEND WILL
REMAIN AT OR A FEW DEGREES BELOW NORMAL FOR MID SEPTEMBER.
BY MONDAY NIGHT...A COLD FRONT WILL MOVE THROUGH THE FORECAST AREA
BRINGING MORE SHOWERS AND A FEW THUNDERSTORMS. THIS FRONT SHOULD
BE OUT OF THE REGION BY TUESDAY MORNING WITH RAIN ENDING FROM WEST
TO EAST. MUCH COOLER AND DRIER AIR WILL MOVE INTO THE AREA BEHIND
THE FRONT WITH AFTERNOON TEMPERATURES ON TUESDAY IN THE 70S. SKIES
SHOULD CLEAR OUT AND WINDS WILL BECOME LIGHT BY WEDNESDAY MORNING
SETTING THE STAGE FOR A RATHER COOL MORNING. MANY LOCATIONS IN THE
NORTHERN HALF OF THE FORECAST AREA WILL SEE READINGS IN THE 40S ON
WEDNESDAY MORNING.
HIGH PRESSURE WILL REMAIN IN CONTROL OF THE WEATHER FROM WEDNESDAY
THROUGH EARLY FRIDAY MORNING WITH NO RAIN AND TEMPERATURES
REMAINING BELOW NORMAL. ANOTHER COLD FRONT WILL BE APPROACHING THE
REGION ON FRIDAY BRINGING A SMALL CHANCE OF SHOWERS AHEAD OF IT.
ARS
&&
.AVIATION...
00Z TAF CYCLE
VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD...EXCEPT FOR SOME BRIEF
LIGHT FOG POSSIBLE AT KMKL LATE TONIGHT. BEST CHANCES FOR
PRECIPITATION SHOULD REMAIN WEST OF THE AREA THROUGH THE PERIOD
THOUGH SOME SHOWERS COULD SNEAK INTO KJBR SAT AFTN. WINDS WILL
GENERALLY BE LIGHT NE.
SJM
&&
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 68 83 66 84 / 30 30 30 50
MKL 61 81 60 82 / 20 30 30 50
JBR 64 78 62 78 / 50 40 40 50
TUP 64 86 65 86 / 20 20 20 40
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1151 PM CDT WED SEP 12 2012
.DISCUSSION...
VFR CONDITIONS AND THUNDERSTORMS WILL DOMINATE WEST CENTRAL TEXAS
FOR THE NEXT 24 HOURS. SEE THE BELOW AVIATION SECTION FOR
ADDITIONAL INFORMATION.
&&
.AVIATION...
PLAN FOR THUNDERSTORMS TO DOMINATE WEST CENTRAL TEXAS WEATHER FOR
THE NEXT 24 HOURS. THE LATEST RUC BRINGS A SURFACE OUTFLOW
BOUNDARY ACROSS THE BIG COUNTRY AND INTO THE CONCHO VALLEY BY
AROUND 09Z. ALTHOUGH SHOWERS AND A FEW THUNDERSTORMS MAY ACCOMPANY
THIS BOUNDARY...I WILL LIKELY NOT INCLUDE ANY PREVAILING OR TEMPO
THUNDERSTORMS IN THE ABILENE OR SAN ANGELO TERMINALS FOR THAT TIME
FRAME. I WILL LIKELY INCLUDE A TEMPO WIND GROUP FOR THE ABILENE
TERMINAL FOR NORTHWEST WINDS FROM 08Z TO 12Z. OTHERWISE...THE
PREVIOUS TERMINALS LOOK ON TRACK.
HUBER
&&
.PREV DISCUSSION... /ISSUED 643 PM CDT WED SEP 12 2012/
DISCUSSION...
LOOK FOR VFR CONDITIONS AND THUNDERSTORMS TO DOMINATE WEST CENTRAL
TEXAS FOR THE NEXT 24 HOURS. AVIATION BELOW HAS DETAILS.
AVIATION...
MODELS CONTINUE TO INDICATE VFR CONDITIONS ACROSS WEST CENTRAL
TEXAS FOR THE NEXT 24 HOURS. IN ADDITION...AN APPROACHING UPPER-
LEVEL TROUGH OF LOW PRESSURE AND AN ASSOCIATED SURFACE COLD FRONT
WILL CONTINUE TO INITIATE SHOWERS AND THUNDERSTORMS ACROSS MANY
LOCATIONS IN WEST CENTRAL TEXAS DURING THE NEXT 24 HOURS. EXPECT
MAINLY SCATTERED SHOWERS AND A FEW THUNDERSTORMS OVERNIGHT
TONIGHT. THEN...PLAN FOR MANY MORE SHOWERS AND THUNDERSTORMS
TOMORROW...ESPECIALLY DURING THE AFTERNOON HOURS.
HUBER
PREV DISCUSSION... /ISSUED 408 PM CDT WED SEP 12 2012/
SHORT TERM...
CHANGES ARE ON THE HORIZON FOR WEST CENTRAL TEXAS AS WE DEVIATE FROM
OUR FAMILIAR HOT AND DRY TO MUCH COOLER AND WET WX CONDITIONS FOR
THE NEXT FEW DAYS. WE ALREADY HAVE A FAIRLY EXPANSIVE MID LEVEL
CLOUD DECK OVER WEST TX WITH SOME ASSOCIATED LIGHT RADAR ECHOS OVER
THE SOUTH PLAINS. MOST OF THIS HAS NOT BEEN REACHING THE GROUND BUT
INTENSITIES HAVE BEEN INCREASING OVER THE PAST HOUR OR SO AS THE
LEADING EDGE OF ENHANCED SYNOPTIC SCALE ASCENT OVERSPREADS THE AREA.
THIS IS ASSOCIATED WITH A COMPACT SHORTWAVE TROF CURRENTLY LOCATED
JUST TO THE ESE OF EL PASO IN CONJUNCTION WITH THE LARGER TROF
MOVING ACROSS THE ROCKIES. AS THIS FEATURE APPROACHES...LIFT WILL
INCREASE ACROSS THE REGION AND THUNDERSTORMS ARE EXPECTED TO
DEVELOP...MAINLY TOWARD MIDNIGHT AND THEREAFTER.
LOOKING UPSTREAM...A COLD FRONT HAS MOVED INTO THE PANHANDLE AND
WILL MOVE SOUTH OVERNIGHT...REACHING THE I-20 CORRIDOR BY AROUND
12Z. AS THIS COLD FRONT PROGRESSES SOUTH DURING THE DAY...COLD
ADVECTION AND ABUNDANT CLOUD COVER WILL AID IN KEEPING TEMPS
GENERALLY IN THE 70S. LOWER TO MID 80S ARE EXPECTED OVER THE
SOUTHEAST ZONES WHERE A LATER FROPA WILL ALLOW TEMPS TO WARM THROUGH
EARLY AFTERNOON. POPS WERE RAISED ACROSS THE BOARD WITH 70-90
PERCENT CHANCES IN MOST AREAS. LOCALIZED RAINFALL AMOUNTS MAY EXCEED
1-2 INCHES IN AREAS WHERE THE STRONGER CELLS DEVELOP. MOST AREAS ARE
EXPECTED TO SEE IN EXCESS OF 1/2 INCH.
JOHNSON
LONG TERM...
A WEAK CLOSED LOW IS PROGGED TO DEVELOP NEAR THE TEXAS/NEW MEXICO
BORDER THURSDAY NIGHT...WITH THE TROUGH AXIS EXTENDING TO THE
SOUTHWEST INTO SOUTHERN ARIZONA. LITTLE MOVEMENT WITH THIS UPPER
LOW AND TROUGH ARE INDICATED FOR FRIDAY. THE MODELS HAVE TRENDED
SLOWER WITH THE PROGRESSION OF THIS SYSTEM...WITH THE TROUGH AXIS
NOT EXPECTED TO MOVE EAST ACROSS WEST CENTRAL TEXAS UNTIL LATE
SATURDAY NIGHT/EARLY SUNDAY MORNING. A COOL AND MOIST AIRMASS IS
FORECAST TO REMAIN OVER OUR AREA THROUGH FRIDAY AND INTO SATURDAY.
PRECIPITABLE WATER VALUES NEAR OR ABOVE 1.5 INCHES WILL BE PRESENT
FRIDAY. WITH THIS MOISTURE AND LIFT ASSOCIATED WITH THE UPPER
TROUGH TO OUR WEST/NORTHWEST...EXPECT NUMEROUS SHOWERS AND A FEW
THUNDERSTORMS TO OCCUR THURSDAY NIGHT AND FRIDAY. RAIN CHANCES
WILL BEGIN TO DECREASE FRIDAY NIGHT...AND HAVE LOW CHANCE POPS
TRAILING OFF FROM THE NORTHWEST SATURDAY AND SATURDAY NIGHT.
WITH THE COMBINATION OF OVERCAST CONDITIONS...PRECIPITATION AND A
COOL AIRMASS IN PLACE...TEMPERATURES ON FRIDAY WILL BE WELL-BELOW
NORMAL. NOT EXPECTING MUCH BEYOND A 10 DEGREE TEMPERATURE RECOVERY
DURING THE DAY FRIDAY. HAVE REDUCED THE DIURNAL TEMPERATURE RANGE
THROUGH SATURDAY...GIVEN THE MOIST CONDITIONS AND PERSISTENT CLOUD
COVER.
DECREASING CLOUD COVER FROM THE NORTHWEST IS EXPECTED ON SUNDAY...
AS THE TROUGH MOVES EAST OF OUR AREA AND DRIER AIR ADVECTS INTO
WEST CENTRAL TEXAS. THE AIRMASS WILL MODIFY QUICKLY WITH TEMPERATURES
REACHING THE MID TO UPPER 80S FOR HIGHS SUNDAY. A WARMING TREND IS
INDICATED EARLY NEXT WEEK PER THE 850 MB THERMAL PATTERN.
THE 12Z MODELS CAST MORE DOUBT ON SOUTHWARD PROGRESS OF A COLD FRONT
INTO OUR AREA AND ASSOCIATED RAIN CHANCES NEXT TUESDAY. INDICATIONS
ARE FOR THIS TO BE A WEAK FRONT AT BEST. HAVE RETAINED THE SLIGHT
CHANCE POP FOR NOW AND HAVE TRENDED DAILY MAXIMUM TEMPERATURES
WARMER NEXT WEEK.
19
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 67 76 60 70 59 / 30 80 50 50 30
SAN ANGELO 70 79 60 70 60 / 30 80 60 60 40
JUNCTION 70 84 63 73 61 / 20 70 60 60 50
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
HUBER
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
313 PM CDT THU SEP 13 2012
.SHORT TERM...TONIGHT THROUGH SUNDAY
313 PM CDT THU SEP 13 2012
MAIN FORECAST CONCERNS ARE FOG IN RIVER VALLEYS AND FROST POTENTIAL
TONIGHT...THEN TEMPERATURES FRIDAY THROUGH SUNDAY.
LATEST WATER VAPOR SATELLITE IMAGERY SHOWS UPPER LEVEL LOW OVER
SOUTHERN MANITOBA AND SHORTWAVE TROUGH EMBEDDED IN THE
NORTHWESTERLY FLOW OVER CENTRAL NORTH DAKOTA. LATEST 19Z SURFACE
ANALYSIS INDICATING HIGH PRESSURE BUILDING INTO WESTERN IOWA AND
DRIER AIR BEGINNING TO ADVECT INTO WESTERN FORECAST AREA...WITH
DEWPOINTS FALLING INTO THE MIDDLE 20S TO MIDDLE 30S ACROSS SOUTHERN
AND WESTERN MINNESOTA.
THE 13.12Z GFS/NAM ARE IN DECENT AGREEMENT WITH DEVELOPING ZONAL
FLOW ACROSS THE NORTHERN TIER STATES THIS WEEKEND. THE MOST
SIGNIFICANT DIFFERENCE BETWEEN THE DETERMINISTIC MODELS IS THE NAM
SLIGHTLY FARTHER SOUTH WITH SURFACE FRONT SUNDAY THAN THE GFS. THIS
WOULD PUSH THE MOISTURE CONVERGENCE AND LIFT ALONG THE FRONT INTO THE
NORTHERN FORECAST AREA. HOWEVER...FEEL THE NAM IS TOO FAR SOUTH AND
FOLLOW MORE TOWARDS THE GFS DURING THIS TIMEFRAME.
TONIGHT...THE DETERMINISTIC 13.12Z GFS/NAM AND 13.18Z RAP ARE PICKING
UP WEAK WARM AIR ADVECTION AT 700MB OUT AHEAD OF THE SHORTWAVE TROUGH
OVER CENTRAL NORTH DAKOTA AND PRODUCING MOISTURE IN THE 600-800MB
LAYER PER BUFKIT SOUNDINGS. THE MOISTURE IN THIS LAYER THE
DETERMINISTIC MODELS PROG INTO THE FORECAST AREA AFTER 03Z FRIDAY AND
WILL HAVE IMPACTS ON TEMPERATURES AND FOG POTENTIAL. AT THIS TIME...
UNCERTAINTY EXIST ABOUT FOG DEVELOPMENT IN THE MISSISSIPPI RIVER
VALLEY...AS THE 13.12Z DETERMINISTIC MODELS ARE IN AGREEMENT SOME MID
LEVEL CLOUDS WILL DRIFT OVER THE FORECAST AREA BETWEEN 03Z-09Z
TIMEFRAME. FOR NOW...HAVE KEPT PATCHY TO AREAS FOG IN RIVER VALLEYS.
TEMPERATURES WILL BE AFFECTED BY THE SCATTERED TO BROKEN MID LEVEL
DECK CLOUDS ESPECIALLY OVER SOUTHEAST MINNESOTA AND NORTHEAST IOWA.
THE 13.12Z DETERMINISTIC MODELS DISSIPATE MOISTURE/MID CLOUD DECK
OVER WESTERN/CENTRAL WISCONSIN AND TEMPERATURES ARE EXPECTED TO FALL
INTO THE MIDDLE 30S OVER PARTS OF CENTRAL WISCONSIN AND PRODUCE
ISOLATED SPOTS OF PATCHY FROST.
SURFACE RIDGE DOMINATES THE FORECAST AREA FRIDAY INTO SATURDAY
PROVIDING DRY WEATHER CONDITIONS. TEMPERATURES ARE EXPECTED TO
MODERATE AND BE SLIGHTLY ABOVE NORMAL BOTH DAYS...AS THE 13.12Z
DETERMINISTIC MODELS ADVECT SOME WARMER AIR INTO THE AREA.
SURFACE RIDGE BUILDS INTO THE OHIO RIVER VALLEY SATURDAY
NIGHT/SUNDAY AND SOUTHERLY WINDS ON THE BACKSIDE OF THE HIGH PRESSURE
SYSTEM AND ALOFT...WILL USHER IN LOW LEVEL MOISTURE FROM THE
SOUTHERN PLAINS STATES NORTHWARD INTO THE FORECAST AREA. THIS IS
EVIDENT IN THE 850MB TO 925MB RELATIVE HUMIDITY FIELDS PER 13.12Z
GFS/NAM. HAVE INCREASE SKY COVER SLIGHTLY SUNDAY.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
313 PM CDT THU SEP 13 2012
MAIN FORECAST CONCERNS THROUGH THE PERIOD ARE PRECIPITATION CHANCES
AND TEMPERATURES. THE 13.12Z GFS/ECMWF/GEM ARE IN ALL PRETTY GOOD
AGREEMENT IN DIGGING UPPER LEVEL TROUGH OVER THE NORTHERN PLAINS AND
THE UPPER GREAT LAKES REGION THROUGH FORECAST PERIOD. BIGGEST
DIFFERENCE BETWEEN THE DETERMINISTIC MODELS IS TIMING OF THE
EMBEDDED SHORTWAVE TROUGHS IN THE NORTHERLY FLOW ALOFT. THIS WILL
HAVE IMPACTS ON TIMING OF PRECIPITATION CHANCES INTO THE FORECAST
AREA THROUGH THE FORECAST PERIOD. THE DETERMINISTIC 13.12Z
GFS/ECMWF/GEM CONTINUE TO SHOW COLDER AIR TO FILTER INTO THE AREA
WITH 850MB TEMPERATURES DROPPING TO AROUND ZERO DEGREES CELSIUS AT
12Z TUESDAY. THE 13.00Z GEFS INDICATE STANDARD ANOMALIES OF MINUS 1
TO MINUS 1.5 OVER THE FORECAST AREA MIDDLE OF NEXT WEEK.
TEMPERATURES WILL BE BELOW NORMAL THROUGH MUCH OF THE FORECAST
PERIOD WITH HIGH TEMPERATURES RISING INTO THE 50S TO 60S.
&&
.AVIATION...THROUGH 18Z FRIDAY
1228 PM CDT THU SEP 13 2012
BIGGEST CONCERN IS LIFR VALLEY FOG AT KLSE OVERNIGHT. QUITE A FEW
POSITIVES FOR LIFR VALLEY FOG INCLUDING LIGHTER WINDS IN THE
0-1KFT LAYER...RECENT SOAKING RAINS...CLOUDS PREVENTING AN THE MIXING
OF BOUNDARY LAYER MOISTURE TODAY AND A LOWER MAX TEMPERATURE
TODAY. THE LAST ITEMS MAKE FOR A SMALLER TEMPERATURE DEWPOINT
SPREAD...FAVORABLE FOR FOG FORMATION OVERNIGHT. THE ONLY NEGATIVE
RIGHT NOW IS AN UPSTREAM SHORTWAVE TROUGH THAT IS MOVING INTO MN
OVERNIGHT AND INTO WI. A FAIRLY CONSISTENT SIGNAL EXISTS IN THE
HIGH-RESOLUTION MODELS THAT THE WARM ADVECTION AHEAD OF THAT
SYSTEM WILL PROVIDE SOME INSTABILITY FOR SOME MID-LEVEL CLOUDS AND
VERY LIGHT RADAR ECHO. THIS WOULD ARRIVE AT KLSE BETWEEN
06-09Z...AND PROVIDE NO RAIN BUT SCT-BKN100 CLOUDS TO LIMIT
COOLING.
CONFIDENCE IS HIGH THAT IF THIS MID-LEVEL CLOUD DOES NOT MOVE OVER
KLSE..AN LIFR FOG EVENT WILL OCCUR FROM 09-14Z. AT THIS TIME...A
MAJORITY OF THE NUMERICAL GUIDANCE DOES GENERATE THIS CLOUD AND
THEREFORE THE KLSE TAF CONTAINS A REDUCTION ONLY TO MVFR IN FOG.
THIS MID-CLOUD FORECAST SHOULD BE RESOLVED VIA LATER TAF ISSUANCES
AND WE WILL BE PRUDENT TO UPDATE THE KLSE TAF AS SOON AS THE PROBABLE
OUTCOME HAS MORE CONFIDENCE.
A VFR PERIOD IS EXPECTED AT KRST AND KLSE FROM FRIDAY AT 15Z THROUGH
SUNDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
313 PM CDT THU SEP 13 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM.....DTJ
LONG TERM......DTJ
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1229 PM CDT THU SEP 13 2012
.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
307 AM CDT THU SEP 13 2012
MAIN FORECAST CONCERNS ARE ON TIMING THE END OF ONGOING
PRECIPITATION...POTENTIAL FOR FROST AND VALLEY FOG TONIGHT...AND
POSSIBLE FIRE WEATHER CONCERNS FOR SATURDAY.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE WESTERN U.S. INTO SOUTHWEST CANADA...
TROUGHING FROM SOUTH CENTRAL CANADA INTO NEBRASKA...AND RIDGING
ALONG THE EAST COAST. WITHIN THE UPPER TROUGHING...NOTABLE FEATURES
INCLUDE A SHORTWAVE OVER NORTHWEST IOWA AND AN UPPER LOW OVER
CENTRAL SASKATCHEWAN. THE FORECAST AREA RESIDES IN SOUTHWEST FLOW
AHEAD OF THE NORTHWEST IOWA SHORTWAVE...AS WELL AS IN A RIGHT
ENTRANCE REGION OF A 100-120KT JET AT THE TROPOPAUSE EXTENDING
FROM CENTRAL MINNESOTA INTO NORTHERN ONTARIO. THE FORECAST AREA
ALSO RESIDES IN A LOW TO MID LEVEL FRONTOGENESIS ZONE...WHICH
SHOWS UP IN 700MB PROFILER DATA AS WELL AS IN 850MB TEMPS FROM 00Z
RAOBS (8C AT MPX COMPARED TO 13C AT GRB AND 16C AT DVN). THE
COMBINATION OF ALL THESE FORCING FEATURES RESULTING IN A BAND OF
SHOWERS FROM THE OKLAHOMA AND TEXAS PANHANDLES NORTHEASTWARD TO LA
CROSSE AND INTO EASTERN UPPER MICHIGAN. BACK EDGE OF SHOWERS WAS
NEAR ALBERT LEA AND DODGE CENTER MN. BACK EDGE OF THE CIRRUS CLOUD
COVER WAS QUITE A BIT FARTHER NORTHWEST...THOUGH...NEAR ST CLOUD.
PLENTY OF LOW LEVEL DRY AIR ALSO TO THE NORTHWEST...NOTED BY
SURFACE DEWPOINTS IN THE TEENS AND LOW 20S ACROSS NORTH DAKOTA TO
ALEXANDRIA MN. GOES SOUNDER PRECIPITABLE WATER IMAGERY DEPICTING
VALUES AROUND 0.3 INCHES OVER NORTH DAKOTA...OR ABOUT 50 PERCENT
OF NORMAL.
TODAY AND TONIGHT...AFTER MUCH STRUGGLES THE PAST COUPLE DAYS WITH
THE UPPER LOW IN SASKATCHEWAN...MODELS ARE ALL NOW IN SYNC WITH
BASICALLY WHAT THE OUTLIER 11.00Z NAM SUGGESTED. MODELS DROP THE
UPPER LOW INTO THE MEAN TROUGHING... REACHING NORTHERN MINNESOTA
BY 00Z. THE UPPER LOW THEN RAPIDLY HEADS EAST TO NORTHERN LOWER
MICHIGAN BY 12Z FRIDAY. MEANWHILE...THE NORTHWEST IOWA SHORTWAVE
IS PROGGED TO MOVE NORTHEAST THROUGH THE FORECAST AREA DURING THE
DAY TODAY. THE COMBINATION OF THE UPPER LOW AND IOWA SHORTWAVE WILL
PUSH THE FRONTOGENESIS ZONE AND ITS ASSOCIATED SHOWERS EAST OUT OF
THE FORECAST AREA. TIMING WISE...MOST OF THE AREA SHOULD BE DRY
AFTER 18Z. IN ADDITION...AS THE UPPER LOW APPROACHES...DRIER AIR
AND CLEARING SEEN OFF TO OUR NORTHWEST OVER THE DAKOTAS AND
NORTHWEST MINNESOTA WILL ADVECT IN. PREVIOUSLY THERE WAS CONCERN
ABOUT THE UPPER LOW DROPPING INTO MINNESOTA BRINGING SOME ISOLATED
PRECIPITATION TO THE AREA. HOWEVER...NOW THAT MODELS ARE TRACKING
THE UPPER LOW SO FAR NORTH...AND ITS TIMING DOES NOT COINCIDE WITH
PEAK HEATING...NOT ANTICIPATING ANY PRECIPITATION WITH IT.
THEREFORE...DRY CONDITIONS ARE EXPECTED ONCE THE PRECIPITATION
ASSOCIATED WITH THE FRONTOGENESIS ENDS. IN FACT...INDICATIONS ARE
THAT MUCH OF THE FORECAST AREA WILL BE CLEAR TONIGHT. WITH
PRECIPITABLE WATER VALUES DROPPING TO 0.3-0.4 INCHES AND LIGHT
WINDS ASSOCIATED WITH HIGH PRESSURE OVERHEAD AFTER MIDNIGHT...
TEMPERATURES ARE GOING TO TANK. HAVE LEANED TOWARDS THE COLDER OF
GUIDANCE...DROPPING THE TYPICAL COLD SPOTS IN WISCONSIN TO NEAR
FREEZING WITH MID 30S TO MID 40S ELSEWHERE. PATCHY FROST LOOKS
LIKELY ACROSS TAYLOR...CLARK... JACKSON...MONROE...JUNEAU AND
ADAMS COUNTIES. APPEARS FROST COVERAGE RIGHT NOW SHOULD STAY LOW
ENOUGH TO PRECLUDE THE NEED FOR ANY ADVISORY. WITH RECENT RAINS
AND LATE IN THE DAY CLEARING...VALLEY FOG ALSO LOOKS LIKELY FOR
THE WISCONSIN RIVER VALLEY AND MISSISSIPPI RIVER TRIBUTARIES. THE
MAIN MISSISSIPPI VALLEY HAS A CONCERN WITH THE DRY AIR
IMPACT...GIVEN THAT TEMP/DEWPOINT SPREADS OF AT LEAST 30F ARE
POSSIBLE BY LATE THIS AFTERNOON. LIGHT WINDS EXTENDING UP A FEW
THOUSAND FEET AND RECENT RAIN SHOULD ALLOW GOOD DEWPOINT RECOVERY
THIS EVENING...BUT WHETHER IT IS ENOUGH IS UNCERTAIN. THEREFORE...
HAVE KEPT THE MISSISSIPPI RIVER VALLEY AT PATCHY FOG FOR THE
PRESENT TIME.
FRIDAY THROUGH SATURDAY NIGHT...MODELS SHOW THAT THE RIDGING
CURRENTLY OVER SOUTHWEST CANADA WILL BREAK DOWN...IN RESPONSE TO
TROUGHING OVER THE GULF OF ALASKA PUSHING EAST. AS SUCH...WE SHOULD
SEE THE FLOW OVER THE NORTHERN U.S. TURN MORE ZONAL....ALLOWING SOME
WARMER AIR THAT GETS DOWNSLOPED OFF THE ROCKIES TO PUSH INTO THE
FORECAST AREA. THERE ARE INDICATIONS THAT TOWARDS LATE SATURDAY
NIGHT SOME WEAK RIDGING WILL BUILD OVER THE WESTERN GREAT LAKES...IN
RESPONSE TO THE GULF OF ALASKA TROUGHING STALLING OVER CENTRAL
CANADA. EXPECT A COLD FRONT TO SEPARATE THE TROUGHING/RIDGING
INTERFACE...WHICH BY 12Z SUNDAY WILL EXTEND FROM NORTHWEST ONTARIO
SOUTHWEST INTO CENTRAL SOUTH DAKOTA. PLENTY OF DRY AIR FROM THE
LOW TO UPPER LEVELS OF THE TROPOSPHERE AHEAD OF THE FRONT IS
EXPECTED TO PRODUCE CLEAR SKIES FOR MUCH OF THIS PERIOD. A
TIGHTENING PRESSURE GRADIENT AHEAD OF THE FRONT SHOULD HELP TO
INCREASE THE WINDS OVER THE FORECAST AREA...BEGINNING FRIDAY NIGHT
AND ESPECIALLY FOR SATURDAY AND SATURDAY NIGHT. WITH MORE
WIND...AS WELL AS PRECIPITABLE WATER VALUES PROGGED TO CLIMB TO
AROUND 0.5 INCHES... ANTICIPATE WARMER LOWS FOR FRIDAY NIGHT AND
THUS LITTLE CONCERN FOR FOG OR FROST. 850MB TEMPS OF 8-10C ON
FRIDAY SHOULD ALLOW FOR HIGHS IN THE LOWER 70S. ON SATURDAY...
THOSE 850MB TEMPS CLIMB TO 11-13C AND WITH THE INCREASING
SOUTHWEST WIND...TEMPERATURES SHOULD TOP OUT IN THE MID TO UPPER
70S. A FEW LOCATIONS MAY EVEN REACH 80. MAY HAVE TO WATCH FIRE
WEATHER CONDITIONS FOR SATURDAY. SEE FIRE WEATHER DISCUSSION
BELOW. EVEN WARMER LOWS EXPECTED SATURDAY NIGHT WITH A SOUTHWEST
BREEZE CONTINUING...THOUGH THE DRY AIR LIKELY ALLOWING SOME OF THE
TYPICAL COLD SPOTS TO DROP INTO THE LOW TO MID 40S.
.LONG TERM...SUNDAY THROUGH WEDNESDAY NIGHT
307 AM CDT THU SEP 13 2012
13.00Z ECMWF/GFS/UKMET AND GFS ENSEMBLES ARE IN EXCELLENT AGREEMENT
ON A MAJOR PATTERN SHIFT FOR THE LONG TERM PERIOD. THE 13.00Z
CANADIAN HAS THE PATTERN SHIFT TOO...BUT WILL BE DISCOUNTED AS AN
OUTLIER SINCE THE POSITION OF THE UPPER TROUGHING COME 00Z TUESDAY
AND ESPECIALLY BY 00Z WEDNESDAY DOES NOT AGREE WITH THE
AFOREMENTIONED MODELS.
ON SUNDAY...RIDGING REALLY AMPLIFIES OVER FAR WESTERN CANADA. IN
TURN...THIS FORCES A DEEPENING TROUGH DOWNSTREAM...WHICH DIGS DOWN
INTO THE NORTHERN PLAINS SUNDAY NIGHT. THIS TROUGH DIGGING DOWN
SHOULD HELP PUSH EASTWARD THE COLD FRONT THAT WAS OVER SOUTH DAKOTA
12Z SUNDAY. IT APPEARS THE FRONT WILL CROSS THE FORECAST AREA SUNDAY
NIGHT. PRIOR TO THE FRONTAL PASSAGE...SUNDAY SHOULD BE ANOTHER WARM
DAY WITH 850MB TEMPS OF 12-14C AND PLENTY OF SUN. HIGHS ARE LIKELY
TO BE EQUAL TO OR SLIGHTLY HIGHER THAN SATURDAY. ANOTHER
FRONTOGENETIC BAND OF PRECIPITATION LOOKS TO DEVELOP ON THE COOL
SIDE OF THE FRONT. THEREFORE...40-60 PERCENT CHANCES OF PRECIPITATION
EXIST ACROSS THE FORECAST AREA FOR BOTH SUNDAY NIGHT AND MONDAY.
FUTURE SHIFTS MAY BE ABLE TO INCREASE THESE MORE. ADDED A LOW
CHANCE OF THUNDER AS WELL GIVEN MUCAPE FORECASTS OF 300 J/KG OR SO
WITH THE FRONTOGENESIS BAND. THE UPPER TROUGH LOOKS TO DIG INTO
THE AREA FOR MONDAY NIGHT AND TUESDAY. COMBINATION OF COOL
TEMPERATURES ALOFT AND ANY SHORTWAVES MOVING THROUGH THE TROUGH
RESULTS IN THE NEED TO MAINTAIN 20-30 PERCENT CHANCES DURING THIS
TIME FRAME. A BRIEF BREAK IN PRECIPITATION IS ANTICIPATED TUESDAY
NIGHT...THEN MODELS HAVE ANOTHER POTENT SHORTWAVE DROPPING DOWN
INTO THE NORTHERN PLAINS ON WEDNESDAY. SOME WARM ADVECTION AND
DPVA FORCED PRECIPITATION IS POSSIBLE AHEAD OF IT...THOUGH
AVAILABLE MOISTURE IS A QUESTION MARK...THUS CONSENSUS 20 PERCENT
CHANCES ARE WARRANTED.
AS THE UPPER TROUGH DROPS INTO THE AREA ON MONDAY...850MB TEMPS
REALLY TUMBLE. BY 00Z TUESDAY...THEY ARE FORECAST DOWN TO AT LEAST
3-6C AND MAY EVEN FALL A LITTLE MORE...ESPECIALLY AS WE HEAD TO 12Z
TUESDAY. AS A RESULT...BOTH MONDAY AND TUESDAY LOOK CHILLY WITH
HIGHS IN THE 60S MONDAY AND 50S TUESDAY. 850MB TEMPS SHOULD WARM
BACK UP TUESDAY NIGHT INTO WEDNESDAY...PERHAPS PEAKING AS HIGH AS
8-11C PER 13.00Z ECMWF...IN RESPONSE TO THE NEXT POTENT SHORTWAVE
DROPPING THROUGH THE TROUGH. THEREFORE...HIGHS SHOULD CLIMB BACK
INTO THE 60S FOR WEDNESDAY.
FOR THOSE LOOKING FARTHER OUT...IT APPEARS THE MEAN UPPER TROUGHING
WILL STAY IN PLACE AND PERHAPS EVEN AMPLIFY THROUGH THE END OF NEXT
WEEK...PER THE 13.00Z ECMWF/GFS. THIS IS ALSO IN GOOD AGREEMENT WITH
THE 12.00Z CFS WHICH HAS BEEN SHOWING A CONSISTENT SIGNAL OF
BELOW NORMAL TEMPERATURES FOR THE LATTER HALF OF SEPTEMBER OVER
THE CENTRAL AND EASTERN PORTION OF THE U.S.
&&
.AVIATION...THROUGH 18Z FRIDAY
1228 PM CDT THU SEP 13 2012
BIGGEST CONCERN IS LIFR VALLEY FOG AT KLSE OVERNIGHT. QUITE A FEW
POSITIVES FOR LIFR VALLEY FOG INCLUDING LIGHTER WINDS IN THE
0-1KFT LAYER...RECENT SOAKING RAINS...CLOUDS PREVENTING AN THE MIXING
OF BOUNDARY LAYER MOISTURE TODAY AND A LOWER MAX TEMPERATURE
TODAY. THE LAST ITEMS MAKE FOR A SMALLER TEMPERATURE DEWPOINT
SPREAD...FAVORABLE FOR FOG FORMATION OVERNIGHT. THE ONLY NEGATIVE
RIGHT NOW IS AN UPSTREAM SHORTWAVE TROUGH THAT IS MOVING INTO MN
OVERNIGHT AND INTO WI. A FAIRLY CONSISTENT SIGNAL EXISTS IN THE
HIGH-RESOLUTION MODELS THAT THE WARM ADVECTION AHEAD OF THAT
SYSTEM WILL PROVIDE SOME INSTABILITY FOR SOME MID-LEVEL CLOUDS AND
VERY LIGHT RADAR ECHO. THIS WOULD ARRIVE AT KLSE BETWEEN
06-09Z...AND PROVIDE NO RAIN BUT SCT-BKN100 CLOUDS TO LIMIT
COOLING.
CONFIDENCE IS HIGH THAT IF THIS MID-LEVEL CLOUD DOES NOT MOVE OVER
KLSE..AN LIFR FOG EVENT WILL OCCUR FROM 09-14Z. AT THIS TIME...A
MAJORITY OF THE NUMERICAL GUIDANCE DOES GENERATE THIS CLOUD AND
THEREFORE THE KLSE TAF CONTAINS A REDUCTION ONLY TO MVFR IN FOG.
THIS MID-CLOUD FORECAST SHOULD BE RESOLVED VIA LATER TAF ISSUANCES AND WE
WILL BE PRUDENT TO UPDATE THE KLSE TAF AS SOON AS THE PROBABLE
OUTCOME HAS MORE CONFIDENCE.
A VFR PERIOD IS EXPECTED AT KRST AND KLSE FROM FRIDAY AT 15Z THROUGH SUNDAY.
&&
.FIRE WEATHER...FRIDAY AND SATURDAY
307 AM CDT THU SEP 13 2012
ON FRIDAY...HIGH PRESSURE OVERHEAD COMBINED WITH PLENTY OF DRY AIR
WILL RESULT IN RELATIVE HUMIDITY VALUES DROPPING TO AROUND 25
PERCENT ACROSS MUCH OF THE AREA. RECENT RAINS PLUS WINDS LESS THAN
10 MPH SHOULD PRECLUDE ANY FIRE WEATHER CONCERNS...THOUGH THE DRY
AIR AND FULL SUNSHINE WILL HELP TO DRY OUT FUELS.
ON SATURDAY...THE COMBINATION OF SOUTHWEST WINDS INCREASE TO 10 TO
15 MPH WITH HIGHER GUSTS...ALONG WITH PLENTY OF DRY AIR IN THE
ATMOSPHERE ALLOWING FOR GOOD MIXING SHOULD SEND RELATIVE HUMIDITY
VALUES PLUMMETING TO 25 TO 30 PERCENT IN THE AFTERNOON. LOWEST
RELATIVE HUMIDITY VALUES AND HIGHEST WINDS LOOK TO OCCUR WEST OF THE
MISSISSIPPI RIVER. IN ADDITION...HIGH TEMPERATURES ARE EXPECTED TO
TOP OUT IN THE MID TO UPPER 70S. WILL HAVE TO WAIT AND SEE HOW MUCH
THE FUELS DRY OUT OVER THE NEXT TWO DAYS...BUT AT LEAST WEATHER WISE
THERE IS SOME CONCERN FOR INCREASED WILDFIRE POTENTIAL. THE CONCERN
WOULD ONLY INCREASE WITH A LITTLE MORE WIND AND/OR LOWER RELATIVE
HUMIDITY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
307 AM CDT THU SEP 13 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM.....AJ
LONG TERM......AJ
AVIATION...BAUMGARDT
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1147 AM CDT THU SEP 13 2012
.UPDATE...MAIN CONCERNS/PROBLEMS OF THE DAY IS TIMING THE
BEGINNING/END OF PRECIP AND HIGH TEMPS. REGARDING HIGHS...THEY
WERE LOWERED AND MODIFIED TO TOP OUT IN THE UPPER 50S TO THE LOW
60S...AS WE WILL HAVE MOSTLY CLOUDY SKIES AND PRECIP TO CONTEND
WITH TODAY. CURRENT TEMPERATURE TREND HAS BEEN TOO FAR AHEAD AND
WARM.
RADAR SHOWS A RAGGED BAND OF LIGHT PRECIP STRETCHING SW-NE ACROSS
TWO-THIRDS OF THE WESTERN PORTION OF THE CWA. HOURLY PRECIPITATION
AMOUNTS HAVE BEEN RANGING FROM ONE TO FIVE HUNDREDTHS OF AN INCH
ACROSS SOUTHWEST AND SOUTH CENTRAL WISCONSIN. OVER THE LAST TWO
HOURS...THE BAND HAS DIMINISHED IN INTENSITY AND BECOME RAGGED AS IT
PROGRESSES EAST. RAIN SHOULD BE FAIRLY STEADY OVER ANY GIVEN AREA
THOUGH WITH A DURATION OF TWO TO THREE HOURS. TOTAL AMOUNTS ARE
ANTICIPATED TO BE AROUND A TENTH AT BEST. ALL NUMERICAL MODELS ARE
SHOWING THIS BAND OF PRECIPITATION...SO CONFIDENCE IS HIGH THAT
AREAS WILL BE HIT WITH A FEW HUNDREDTHS AT LEAST. HRRR IN PARTICULAR
SHOWS IT DIMINISHING AS IT MOVES EAST...WHICH DOES COINCIDE WITH
CURRENT THINKING. SHOULD BE OUT OF FAR SOUTHEAST WISCONSIN BETWEEN
6-7 PM THIS EVENING.
&&
.AVIATION/18Z TAFS/...LIGHT RAIN WILL CONTINUE EASTWARD ACROSS
SOUTHERN WISCONSIN THIS AFTERNOON...SLOWLY WINDING DOWN WEST TO
EAST. THE RAIN SHOULD CLEAR THE SOUTHEAST EARLY EVENING...WITH
JUST LINGERING MID AND HIGH LEVEL CLOUDS. SKIES EXPECTED TO CLEAR
FROM THE WEST THROUGH LATE EVENING...REMAINING MOSTLY CLEAR
THROUGH THE NIGHT AND ALSO THROUGH FRIDAY. VFR CONDITIONS THUS
EXPECTED TO PREVAIL THROUGH TOMORROW.
&&
.PREV DISCUSSION... /ISSUED 326 AM CDT THU SEP 13 2012/
TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM.
WILL CONTINUE TO MARCH THE BAND OF RAIN ACROSS THE FORECAST AREA
TODAY...BUT HAVE HAD TO SLOW IT DOWN QUITE A BIT. FRONTOGENESIS
CONTINUES TO BE THE MAIN FORCING MECHANISM...ESPECIALLY IN THE
800-600MB LAYER AND THIS ALSO SHOWS A DIMINISHING TREND THIS
AFTERNOON. IN ADDITION...THE UPPER DIVERGENCE ASSOCIATED WITH THE
RIGHT ENTRANCE OF THE JET WEAKENS SIGNIFICANTLY THIS AFTERNOON.
PRECIP PROBABILITIES REMAIN FAIRLY HIGH...BUT RAINFALL AMOUNTS
WON/T BE VERY BENEFICIAL...REMAINING ON THE LIGHT SIDE.
TEMPS FELL PRETTY HARD IN THE WAKE OF THE COLD FRONT
OVERNIGHT...AND RECOVERY WILL BE DIFFICULT TODAY GIVEN THE CLOUDS
AND RAIN. THERE WILL BE AN EVAPORATIVE COOLING ELEMENT TO THE
RESTRICTED TEMPS DUE TO THE LOW DEWPOINTS THAT ADVECTED IN. WILL
END THE RAIN FROM WEST TO EAST BEGINNING THIS AFTERNOON...CLEARING
IT OUT OF THE SOUTHEAST BY EARLY TO MID EVENING.
HIGH PRESSURE AND VERY LOW DEWPOINTS ARRIVE TONIGHT. COULD SEE
SOME UPPER 30S READINGS FOR LOW TEMPS TONIGHT...ESPECIALLY WEST OF
MADISON AND IN THE VALLEYS. NOT CONCERNED ABOUT ANY FROST DUE TO
THE WARM SOIL TEMPS.
FRIDAY THROUGH SATURDAY NIGHT...FORECAST CONFIDENCE IS HIGH.
SHORTWAVE TROUGH SHIFTS WELL EAST OF THE AREA FRIDAY...WITH WEST
NORTHWEST WINDS AT 500MB OVER THE REGION THROUGH SATURDAY NIGHT.
AT THE SURFACE...HIGH PRESSURE OVER THE REGION FRIDAY WILL SLIDE
EAST SOUTHEAST THROUGH SATURDAY NIGHT. DRY AIRMASS IN PLACE WILL
BRING QUIET WEATHER TO THE AREA DURING THIS TIME. LIGHT WINDS AND
CLEAR SKIES SHOULD LEAD TO PATCHY FOG IN THE WISCONSIN RIVER
VALLEY.
WEAK WARM AIR ADVECTION IN THE LOW LEVEL OCCURS AS WELL...AS
WINDS SHIFT SOUTH TO SOUTHWEST. 925MB TEMPERATURES CONTINUE TO BE
WARMER ON THE NAM THAN THE GFS/ECMWF DURING THIS TIME. LEANED
TOWARD NAM AND WENT WITH LOWER TO MID 70S FRIDAY...AND MID TO
UPPER 70S SATURDAY. LAKE BREEZE SHOULD COOL THINGS DOWN NEAR LAKE
DURING AFTERNOON HOURS EACH DAY. LOWS IN THE 40S ARE EXPECTED EACH
NIGHT...LOWER 50S CLOSE TO LAKE MICHIGAN.
SUNDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE IS MEDIUM.
ECMWF/GFS CONTINUE TO SHOW QUIET WEATHER THROUGH SUNDAY...AS AREA
REMAINS BETWEEN HIGH PRESSURE TO THE EAST SOUTHEAST...AND THE COLD
FRONT TO THE NORTHWEST. ANOTHER MILD DAY WITH HIGHS IN THE MID TO
UPPER 70S ARE EXPECTED.
THEY BOTH THEN BRING A STRONG COLD FRONT SOUTHEAST TOWARD THE
AREA SUNDAY NIGHT...THEN THROUGH THE AREA MONDAY...EXITING THE
REGION MONDAY NIGHT. BOTH MODELS SHOWING A DIGGING UPPER LEVEL
TROUGH SLIDING SOUTHEAST TOWARD THE AREA SUNDAY NIGHT...THEN
ACROSS THE AREA MONDAY THROUGH TUESDAY...BEFORE MOVING EAST
TUESDAY NIGHT.
GFS FORECAST SOUNDINGS SHOWING GOOD DEEP MOISTURE PROFILES ACROSS
THE AREA MONDAY WITH THE FRONTAL PASSAGE. KEPT HIGH CHANCE POPS
GOING FOR MONDAY ACROSS THE AREA WITH THIS SYSTEM...WITH LIKELY
POPS IN THE FAR WEST. ADDED SLIGHT CHANCES FOR THUNDER AS WELL
WITH WEAK INSTABILITY IN ADJUSTED GFS FORECAST SOUNDINGS.
TEMPERATURES WILL BE RELATIVELY COOL WITH THE CLOUDS AND
PRECIPITATION.
HIGH PRESSURE RIDGE AXIS SHIFTS ACROSS THE AREA TUESDAY NIGHT AND
WEDNESDAY...WITH WARM AIR ADVECTION KICKING IN WEDNESDAY AHEAD OF
ANOTHER SYSTEM MOVING TOWARD THE AREA. KEPT POPS AND COOL
TEMPERATURES GOING FOR THIS PERIOD AS WELL.
AVIATION/12Z TAFS/...BAND OF RAIN WILL CONTINUE TO MARCH ACROSS
THE AREA TODAY. IT LOOKS LIKE THERE WILL BE ABOUT A 6 TO 7 HOUR
PERIOD OF MVFR CIGS WITH RAIN. VSBYS LOOK TO REMAIN VFR THROUGH
THE TAF PERIOD. THE RAIN SHOULD BEGIN TO EXIT THE MADISON AREA BY
EARLY AFTERNOON...AND EARLY EVENING IN THE SOUTHEAST...INCLUDING
THE MILWAUKEE METRO AREA. CLEARING SHOULD BE RAPID IN THE WAKE OF
THE RAIN WITH HIGH PRESSURE AND LIGHT WINDS TONIGHT.
MARINE...A NORTHERLY WIND WILL BRING WAVES CLOSE TO SMALL CRAFT
ADVISORY LEVELS FROM PORT WASHINGTON SOUTH TO WINTHROP HARBOR
TODAY. BUT WILL HOLD OFF ON ISSUING ONE. SMALL CRAFT SHOULD
EXERCISE CAUTION OUT ON LAKE MICHIGAN.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...ET/DDV
TODAY/TONIGHT AND AVIATION/MARINE...DAVIS
FRIDAY THROUGH WEDNESDAY...WOOD
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
618 AM CDT THU SEP 13 2012
.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
307 AM CDT THU SEP 13 2012
MAIN FORECAST CONCERNS ARE ON TIMING THE END OF ONGOING
PRECIPITATION...POTENTIAL FOR FROST AND VALLEY FOG TONIGHT...AND
POSSIBLE FIRE WEATHER CONCERNS FOR SATURDAY.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE WESTERN U.S. INTO SOUTHWEST CANADA...
TROUGHING FROM SOUTH CENTRAL CANADA INTO NEBRASKA...AND RIDGING
ALONG THE EAST COAST. WITHIN THE UPPER TROUGHING...NOTABLE FEATURES
INCLUDE A SHORTWAVE OVER NORTHWEST IOWA AND AN UPPER LOW OVER
CENTRAL SASKATCHEWAN. THE FORECAST AREA RESIDES IN SOUTHWEST FLOW
AHEAD OF THE NORTHWEST IOWA SHORTWAVE...AS WELL AS IN A RIGHT
ENTRANCE REGION OF A 100-120KT JET AT THE TROPOPAUSE EXTENDING
FROM CENTRAL MINNESOTA INTO NORTHERN ONTARIO. THE FORECAST AREA
ALSO RESIDES IN A LOW TO MID LEVEL FRONTOGENESIS ZONE...WHICH
SHOWS UP IN 700MB PROFILER DATA AS WELL AS IN 850MB TEMPS FROM 00Z
RAOBS (8C AT MPX COMPARED TO 13C AT GRB AND 16C AT DVN). THE
COMBINATION OF ALL THESE FORCING FEATURES RESULTING IN A BAND OF
SHOWERS FROM THE OKLAHOMA AND TEXAS PANHANDLES NORTHEASTWARD TO LA
CROSSE AND INTO EASTERN UPPER MICHIGAN. BACK EDGE OF SHOWERS WAS
NEAR ALBERT LEA AND DODGE CENTER MN. BACK EDGE OF THE CIRRUS CLOUD
COVER WAS QUITE A BIT FARTHER NORTHWEST...THOUGH...NEAR ST CLOUD.
PLENTY OF LOW LEVEL DRY AIR ALSO TO THE NORTHWEST...NOTED BY
SURFACE DEWPOINTS IN THE TEENS AND LOW 20S ACROSS NORTH DAKOTA TO
ALEXANDRIA MN. GOES SOUNDER PRECIPITABLE WATER IMAGERY DEPICTING
VALUES AROUND 0.3 INCHES OVER NORTH DAKOTA...OR ABOUT 50 PERCENT
OF NORMAL.
TODAY AND TONIGHT...AFTER MUCH STRUGGLES THE PAST COUPLE DAYS WITH
THE UPPER LOW IN SASKATCHEWAN...MODELS ARE ALL NOW IN SYNC WITH
BASICALLY WHAT THE OUTLIER 11.00Z NAM SUGGESTED. MODELS DROP THE
UPPER LOW INTO THE MEAN TROUGHING... REACHING NORTHERN MINNESOTA
BY 00Z. THE UPPER LOW THEN RAPIDLY HEADS EAST TO NORTHERN LOWER
MICHIGAN BY 12Z FRIDAY. MEANWHILE...THE NORTHWEST IOWA SHORTWAVE
IS PROGGED TO MOVE NORTHEAST THROUGH THE FORECAST AREA DURING THE
DAY TODAY. THE COMBINATION OF THE UPPER LOW AND IOWA SHORTWAVE WILL
PUSH THE FRONTOGENESIS ZONE AND ITS ASSOCIATED SHOWERS EAST OUT OF
THE FORECAST AREA. TIMING WISE...MOST OF THE AREA SHOULD BE DRY
AFTER 18Z. IN ADDITION...AS THE UPPER LOW APPROACHES...DRIER AIR
AND CLEARING SEEN OFF TO OUR NORTHWEST OVER THE DAKOTAS AND
NORTHWEST MINNESOTA WILL ADVECT IN. PREVIOUSLY THERE WAS CONCERN
ABOUT THE UPPER LOW DROPPING INTO MINNESOTA BRINGING SOME ISOLATED
PRECIPITATION TO THE AREA. HOWEVER...NOW THAT MODELS ARE TRACKING
THE UPPER LOW SO FAR NORTH...AND ITS TIMING DOES NOT COINCIDE WITH
PEAK HEATING...NOT ANTICIPATING ANY PRECIPITATION WITH IT.
THEREFORE...DRY CONDITIONS ARE EXPECTED ONCE THE PRECIPITATION
ASSOCIATED WITH THE FRONTOGENESIS ENDS. IN FACT...INDICATIONS ARE
THAT MUCH OF THE FORECAST AREA WILL BE CLEAR TONIGHT. WITH
PRECIPITABLE WATER VALUES DROPPING TO 0.3-0.4 INCHES AND LIGHT
WINDS ASSOCIATED WITH HIGH PRESSURE OVERHEAD AFTER MIDNIGHT...
TEMPERATURES ARE GOING TO TANK. HAVE LEANED TOWARDS THE COLDER OF
GUIDANCE...DROPPING THE TYPICAL COLD SPOTS IN WISCONSIN TO NEAR
FREEZING WITH MID 30S TO MID 40S ELSEWHERE. PATCHY FROST LOOKS
LIKELY ACROSS TAYLOR...CLARK... JACKSON...MONROE...JUNEAU AND
ADAMS COUNTIES. APPEARS FROST COVERAGE RIGHT NOW SHOULD STAY LOW
ENOUGH TO PRECLUDE THE NEED FOR ANY ADVISORY. WITH RECENT RAINS
AND LATE IN THE DAY CLEARING...VALLEY FOG ALSO LOOKS LIKELY FOR
THE WISCONSIN RIVER VALLEY AND MISSISSIPPI RIVER TRIBUTARIES. THE
MAIN MISSISSIPPI VALLEY HAS A CONCERN WITH THE DRY AIR
IMPACT...GIVEN THAT TEMP/DEWPOINT SPREADS OF AT LEAST 30F ARE
POSSIBLE BY LATE THIS AFTERNOON. LIGHT WINDS EXTENDING UP A FEW
THOUSAND FEET AND RECENT RAIN SHOULD ALLOW GOOD DEWPOINT RECOVERY
THIS EVENING...BUT WHETHER IT IS ENOUGH IS UNCERTAIN. THEREFORE...
HAVE KEPT THE MISSISSIPPI RIVER VALLEY AT PATCHY FOG FOR THE
PRESENT TIME.
FRIDAY THROUGH SATURDAY NIGHT...MODELS SHOW THAT THE RIDGING
CURRENTLY OVER SOUTHWEST CANADA WILL BREAK DOWN...IN RESPONSE TO
TROUGHING OVER THE GULF OF ALASKA PUSHING EAST. AS SUCH...WE SHOULD
SEE THE FLOW OVER THE NORTHERN U.S. TURN MORE ZONAL....ALLOWING SOME
WARMER AIR THAT GETS DOWNSLOPED OFF THE ROCKIES TO PUSH INTO THE
FORECAST AREA. THERE ARE INDICATIONS THAT TOWARDS LATE SATURDAY
NIGHT SOME WEAK RIDGING WILL BUILD OVER THE WESTERN GREAT LAKES...IN
RESPONSE TO THE GULF OF ALASKA TROUGHING STALLING OVER CENTRAL
CANADA. EXPECT A COLD FRONT TO SEPARATE THE TROUGHING/RIDGING
INTERFACE...WHICH BY 12Z SUNDAY WILL EXTEND FROM NORTHWEST ONTARIO
SOUTHWEST INTO CENTRAL SOUTH DAKOTA. PLENTY OF DRY AIR FROM THE
LOW TO UPPER LEVELS OF THE TROPOSPHERE AHEAD OF THE FRONT IS
EXPECTED TO PRODUCE CLEAR SKIES FOR MUCH OF THIS PERIOD. A
TIGHTENING PRESSURE GRADIENT AHEAD OF THE FRONT SHOULD HELP TO
INCREASE THE WINDS OVER THE FORECAST AREA...BEGINNING FRIDAY NIGHT
AND ESPECIALLY FOR SATURDAY AND SATURDAY NIGHT. WITH MORE
WIND...AS WELL AS PRECIPITABLE WATER VALUES PROGGED TO CLIMB TO
AROUND 0.5 INCHES... ANTICIPATE WARMER LOWS FOR FRIDAY NIGHT AND
THUS LITTLE CONCERN FOR FOG OR FROST. 850MB TEMPS OF 8-10C ON
FRIDAY SHOULD ALLOW FOR HIGHS IN THE LOWER 70S. ON SATURDAY...
THOSE 850MB TEMPS CLIMB TO 11-13C AND WITH THE INCREASING
SOUTHWEST WIND...TEMPERATURES SHOULD TOP OUT IN THE MID TO UPPER
70S. A FEW LOCATIONS MAY EVEN REACH 80. MAY HAVE TO WATCH FIRE
WEATHER CONDITIONS FOR SATURDAY. SEE FIRE WEATHER DISCUSSION
BELOW. EVEN WARMER LOWS EXPECTED SATURDAY NIGHT WITH A SOUTHWEST
BREEZE CONTINUING...THOUGH THE DRY AIR LIKELY ALLOWING SOME OF THE
TYPICAL COLD SPOTS TO DROP INTO THE LOW TO MID 40S.
.LONG TERM...SUNDAY THROUGH WEDNESDAY NIGHT
307 AM CDT THU SEP 13 2012
13.00Z ECMWF/GFS/UKMET AND GFS ENSEMBLES ARE IN EXCELLENT AGREEMENT
ON A MAJOR PATTERN SHIFT FOR THE LONG TERM PERIOD. THE 13.00Z
CANADIAN HAS THE PATTERN SHIFT TOO...BUT WILL BE DISCOUNTED AS AN
OUTLIER SINCE THE POSITION OF THE UPPER TROUGHING COME 00Z TUESDAY
AND ESPECIALLY BY 00Z WEDNESDAY DOES NOT AGREE WITH THE
AFOREMENTIONED MODELS.
ON SUNDAY...RIDGING REALLY AMPLIFIES OVER FAR WESTERN CANADA. IN
TURN...THIS FORCES A DEEPENING TROUGH DOWNSTREAM...WHICH DIGS DOWN
INTO THE NORTHERN PLAINS SUNDAY NIGHT. THIS TROUGH DIGGING DOWN
SHOULD HELP PUSH EASTWARD THE COLD FRONT THAT WAS OVER SOUTH DAKOTA
12Z SUNDAY. IT APPEARS THE FRONT WILL CROSS THE FORECAST AREA SUNDAY
NIGHT. PRIOR TO THE FRONTAL PASSAGE...SUNDAY SHOULD BE ANOTHER WARM
DAY WITH 850MB TEMPS OF 12-14C AND PLENTY OF SUN. HIGHS ARE LIKELY
TO BE EQUAL TO OR SLIGHTLY HIGHER THAN SATURDAY. ANOTHER
FRONTOGENETIC BAND OF PRECIPITATION LOOKS TO DEVELOP ON THE COOL
SIDE OF THE FRONT. THEREFORE...40-60 PERCENT CHANCES OF PRECIPITATION
EXIST ACROSS THE FORECAST AREA FOR BOTH SUNDAY NIGHT AND MONDAY.
FUTURE SHIFTS MAY BE ABLE TO INCREASE THESE MORE. ADDED A LOW
CHANCE OF THUNDER AS WELL GIVEN MUCAPE FORECASTS OF 300 J/KG OR SO
WITH THE FRONTOGENESIS BAND. THE UPPER TROUGH LOOKS TO DIG INTO
THE AREA FOR MONDAY NIGHT AND TUESDAY. COMBINATION OF COOL
TEMPERATURES ALOFT AND ANY SHORTWAVES MOVING THROUGH THE TROUGH
RESULTS IN THE NEED TO MAINTAIN 20-30 PERCENT CHANCES DURING THIS
TIME FRAME. A BRIEF BREAK IN PRECIPITATION IS ANTICIPATED TUESDAY
NIGHT...THEN MODELS HAVE ANOTHER POTENT SHORTWAVE DROPPING DOWN
INTO THE NORTHERN PLAINS ON WEDNESDAY. SOME WARM ADVECTION AND
DPVA FORCED PRECIPITATION IS POSSIBLE AHEAD OF IT...THOUGH
AVAILABLE MOISTURE IS A QUESTION MARK...THUS CONSENSUS 20 PERCENT
CHANCES ARE WARRANTED.
AS THE UPPER TROUGH DROPS INTO THE AREA ON MONDAY...850MB TEMPS
REALLY TUMBLE. BY 00Z TUESDAY...THEY ARE FORECAST DOWN TO AT LEAST
3-6C AND MAY EVEN FALL A LITTLE MORE...ESPECIALLY AS WE HEAD TO 12Z
TUESDAY. AS A RESULT...BOTH MONDAY AND TUESDAY LOOK CHILLY WITH
HIGHS IN THE 60S MONDAY AND 50S TUESDAY. 850MB TEMPS SHOULD WARM
BACK UP TUESDAY NIGHT INTO WEDNESDAY...PERHAPS PEAKING AS HIGH AS
8-11C PER 13.00Z ECMWF...IN RESPONSE TO THE NEXT POTENT SHORTWAVE
DROPPING THROUGH THE TROUGH. THEREFORE...HIGHS SHOULD CLIMB BACK
INTO THE 60S FOR WEDNESDAY.
FOR THOSE LOOKING FARTHER OUT...IT APPEARS THE MEAN UPPER TROUGHING
WILL STAY IN PLACE AND PERHAPS EVEN AMPLIFY THROUGH THE END OF NEXT
WEEK...PER THE 13.00Z ECMWF/GFS. THIS IS ALSO IN GOOD AGREEMENT WITH
THE 12.00Z CFS WHICH HAS BEEN SHOWING A CONSISTENT SIGNAL OF
BELOW NORMAL TEMPERATURES FOR THE LATTER HALF OF SEPTEMBER OVER
THE CENTRAL AND EASTERN PORTION OF THE U.S.
&&
.AVIATION...TODAY THROUGH FRIDAY MORNING
618 AM CDT THU SEP 13 2012
GOOD VFR CONDITIONS TO PREVAIL AT THE TAF SITES THIS PERIOD...BUT
FOR FRONT AND TAIL ENDS OF THE PERIOD AT KLSE.
THE COLD FRONT AND BAND OF POST-FRONT -RA WILL CONTINUE TO MOVE
SOUTH/EAST OF THE AREA THIS MORNING. IT APPEAR THE -RA WILL MOVE
EAST OF KLSE AROUND 13Z. THE MID CLOUD WAS EXITING KRST AND WILL
MOVE EAST OF KLSE DURING THE MID-MORNING HOURS...LEAVING ONLY
SCT-BKN HIGH CLOUDS INTO THE EARLY AFTERNOON HOURS AS DRIER HIGH
PRESSURE MOVED INTO THE UPPER MIDWEST BEHIND THE COLD FRONT.
THE HIGH WILL BRING MOSTLY CLEAR SKIES...LIGHT WINDS AND COOL TEMPS
TO THE AREA TONIGHT...A FAVORABLE SET-UP FOR LATE NIGHT/EARLY
MORNING VALLEY FOG. BIG QUESTION IS HOW MUCH BOUNDARY LAYER DRYING
WILL SPREAD INTO THE AREA TODAY. PLENTY OF DRY AIR UPSTREAM OVER ND
AND NORTHERN MN EARLY THIS MORNING WITH SFC DEW POINTS IN THE UPPER
20S/30S. THIS AIRMASS EXPECTED TO ADVECT INTO THE AREA TODAY...BUT
THE RECENT RAINS AND GENERALLY LIGHT WINDS MAY PREVENT DEW POINTS
FROM DROPPING MUCH BELOW THE LOWER 40S...THEN ALLOWING THE DEW
POINTS TO RISE A BIT THIS EVENING AND END UP NEAR THE EXPECTED LOWS.
HAVE INTRODUCED BCFG TO KLSE TAF AFTER 08Z FOR NOW WITH PLENTY OF
UNCERTAINTY WITH THE SFC DEW POINT TRENDS TODAY. 00Z TAF SET THIS
EVENING SHOULD BE ABLE TO ADD MORE DETAIL TO THE OVERNIGHT FOG
THREAT IN THE MS/WI RIVER VALLEYS.
&&
.FIRE WEATHER...FRIDAY AND SATURDAY
307 AM CDT THU SEP 13 2012
ON FRIDAY...HIGH PRESSURE OVERHEAD COMBINED WITH PLENTY OF DRY AIR
WILL RESULT IN RELATIVE HUMIDITY VALUES DROPPING TO AROUND 25
PERCENT ACROSS MUCH OF THE AREA. RECENT RAINS PLUS WINDS LESS THAN
10 MPH SHOULD PRECLUDE ANY FIRE WEATHER CONCERNS...THOUGH THE DRY
AIR AND FULL SUNSHINE WILL HELP TO DRY OUT FUELS.
ON SATURDAY...THE COMBINATION OF SOUTHWEST WINDS INCREASE TO 10 TO
15 MPH WITH HIGHER GUSTS...ALONG WITH PLENTY OF DRY AIR IN THE
ATMOSPHERE ALLOWING FOR GOOD MIXING SHOULD SEND RELATIVE HUMIDITY
VALUES PLUMMETING TO 25 TO 30 PERCENT IN THE AFTERNOON. LOWEST
RELATIVE HUMIDITY VALUES AND HIGHEST WINDS LOOK TO OCCUR WEST OF THE
MISSISSIPPI RIVER. IN ADDITION...HIGH TEMPERATURES ARE EXPECTED TO
TOP OUT IN THE MID TO UPPER 70S. WILL HAVE TO WAIT AND SEE HOW MUCH
THE FUELS DRY OUT OVER THE NEXT TWO DAYS...BUT AT LEAST WEATHER WISE
THERE IS SOME CONCERN FOR INCREASED WILDFIRE POTENTIAL. THE CONCERN
WOULD ONLY INCREASE WITH A LITTLE MORE WIND AND/OR LOWER RELATIVE
HUMIDITY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
307 AM CDT THU SEP 13 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM.....AJ
LONG TERM......AJ
AVIATION.......RRS
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
307 AM CDT THU SEP 13 2012
.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
307 AM CDT THU SEP 13 2012
MAIN FORECAST CONCERNS ARE ON TIMING THE END OF ONGOING
PRECIPITATION...POTENTIAL FOR FROST AND VALLEY FOG TONIGHT...AND
POSSIBLE FIRE WEATHER CONCERNS FOR SATURDAY.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE WESTERN U.S. INTO SOUTHWEST CANADA...
TROUGHING FROM SOUTH CENTRAL CANADA INTO NEBRASKA...AND RIDGING
ALONG THE EAST COAST. WITHIN THE UPPER TROUGHING...NOTABLE FEATURES
INCLUDE A SHORTWAVE OVER NORTHWEST IOWA AND AN UPPER LOW OVER
CENTRAL SASKATCHEWAN. THE FORECAST AREA RESIDES IN SOUTHWEST FLOW
AHEAD OF THE NORTHWEST IOWA SHORTWAVE...AS WELL AS IN A RIGHT
ENTRANCE REGION OF A 100-120KT JET AT THE TROPOPAUSE EXTENDING
FROM CENTRAL MINNESOTA INTO NORTHERN ONTARIO. THE FORECAST AREA
ALSO RESIDES IN A LOW TO MID LEVEL FRONTOGENESIS ZONE...WHICH
SHOWS UP IN 700MB PROFILER DATA AS WELL AS IN 850MB TEMPS FROM 00Z
RAOBS (8C AT MPX COMPARED TO 13C AT GRB AND 16C AT DVN). THE
COMBINATION OF ALL THESE FORCING FEATURES RESULTING IN A BAND OF
SHOWERS FROM THE OKLAHOMA AND TEXAS PANHANDLES NORTHEASTWARD TO LA
CROSSE AND INTO EASTERN UPPER MICHIGAN. BACK EDGE OF SHOWERS WAS
NEAR ALBERT LEA AND DODGE CENTER MN. BACK EDGE OF THE CIRRUS CLOUD
COVER WAS QUITE A BIT FARTHER NORTHWEST...THOUGH...NEAR ST CLOUD.
PLENTY OF LOW LEVEL DRY AIR ALSO TO THE NORTHWEST...NOTED BY
SURFACE DEWPOINTS IN THE TEENS AND LOW 20S ACROSS NORTH DAKOTA TO
ALEXANDRIA MN. GOES SOUNDER PRECIPITABLE WATER IMAGERY DEPICTING
VALUES AROUND 0.3 INCHES OVER NORTH DAKOTA...OR ABOUT 50 PERCENT
OF NORMAL.
TODAY AND TONIGHT...AFTER MUCH STRUGGLES THE PAST COUPLE DAYS WITH
THE UPPER LOW IN SASKATCHEWAN...MODELS ARE ALL NOW IN SYNC WITH
BASICALLY WHAT THE OUTLIER 11.00Z NAM SUGGESTED. MODELS DROP THE
UPPER LOW INTO THE MEAN TROUGHING... REACHING NORTHERN MINNESOTA
BY 00Z. THE UPPER LOW THEN RAPIDLY HEADS EAST TO NORTHERN LOWER
MICHIGAN BY 12Z FRIDAY. MEANWHILE...THE NORTHWEST IOWA SHORTWAVE
IS PROGGED TO MOVE NORTHEAST THROUGH THE FORECAST AREA DURING THE
DAY TODAY. THE COMBINATION OF THE UPPER LOW AND IOWA SHORTWAVE WILL
PUSH THE FRONTOGENESIS ZONE AND ITS ASSOCIATED SHOWERS EAST OUT OF
THE FORECAST AREA. TIMING WISE...MOST OF THE AREA SHOULD BE DRY
AFTER 18Z. IN ADDITION...AS THE UPPER LOW APPROACHES...DRIER AIR
AND CLEARING SEEN OFF TO OUR NORTHWEST OVER THE DAKOTAS AND
NORTHWEST MINNESOTA WILL ADVECT IN. PREVIOUSLY THERE WAS CONCERN
ABOUT THE UPPER LOW DROPPING INTO MINNESOTA BRINGING SOME ISOLATED
PRECIPITATION TO THE AREA. HOWEVER...NOW THAT MODELS ARE TRACKING
THE UPPER LOW SO FAR NORTH...AND ITS TIMING DOES NOT COINCIDE WITH
PEAK HEATING...NOT ANTICIPATING ANY PRECIPITATION WITH IT.
THEREFORE...DRY CONDITIONS ARE EXPECTED ONCE THE PRECIPITATION
ASSOCIATED WITH THE FRONTOGENESIS ENDS. IN FACT...INDICATIONS ARE
THAT MUCH OF THE FORECAST AREA WILL BE CLEAR TONIGHT. WITH
PRECIPITABLE WATER VALUES DROPPING TO 0.3-0.4 INCHES AND LIGHT
WINDS ASSOCIATED WITH HIGH PRESSURE OVERHEAD AFTER MIDNIGHT...
TEMPERATURES ARE GOING TO TANK. HAVE LEANED TOWARDS THE COLDER OF
GUIDANCE...DROPPING THE TYPICAL COLD SPOTS IN WISCONSIN TO NEAR
FREEZING WITH MID 30S TO MID 40S ELSEWHERE. PATCHY FROST LOOKS
LIKELY ACROSS TAYLOR...CLARK... JACKSON...MONROE...JUNEAU AND
ADAMS COUNTIES. APPEARS FROST COVERAGE RIGHT NOW SHOULD STAY LOW
ENOUGH TO PRECLUDE THE NEED FOR ANY ADVISORY. WITH RECENT RAINS
AND LATE IN THE DAY CLEARING...VALLEY FOG ALSO LOOKS LIKELY FOR
THE WISCONSIN RIVER VALLEY AND MISSISSIPPI RIVER TRIBUTARIES. THE
MAIN MISSISSIPPI VALLEY HAS A CONCERN WITH THE DRY AIR
IMPACT...GIVEN THAT TEMP/DEWPOINT SPREADS OF AT LEAST 30F ARE
POSSIBLE BY LATE THIS AFTERNOON. LIGHT WINDS EXTENDING UP A FEW
THOUSAND FEET AND RECENT RAIN SHOULD ALLOW GOOD DEWPOINT RECOVERY
THIS EVENING...BUT WHETHER IT IS ENOUGH IS UNCERTAIN. THEREFORE...
HAVE KEPT THE MISSISSIPPI RIVER VALLEY AT PATCHY FOG FOR THE
PRESENT TIME.
FRIDAY THROUGH SATURDAY NIGHT...MODELS SHOW THAT THE RIDGING
CURRENTLY OVER SOUTHWEST CANADA WILL BREAK DOWN...IN RESPONSE TO
TROUGHING OVER THE GULF OF ALASKA PUSHING EAST. AS SUCH...WE SHOULD
SEE THE FLOW OVER THE NORTHERN U.S. TURN MORE ZONAL....ALLOWING SOME
WARMER AIR THAT GETS DOWNSLOPED OFF THE ROCKIES TO PUSH INTO THE
FORECAST AREA. THERE ARE INDICATIONS THAT TOWARDS LATE SATURDAY
NIGHT SOME WEAK RIDGING WILL BUILD OVER THE WESTERN GREAT LAKES...IN
RESPONSE TO THE GULF OF ALASKA TROUGHING STALLING OVER CENTRAL
CANADA. EXPECT A COLD FRONT TO SEPARATE THE TROUGHING/RIDGING
INTERFACE...WHICH BY 12Z SUNDAY WILL EXTEND FROM NORTHWEST ONTARIO
SOUTHWEST INTO CENTRAL SOUTH DAKOTA. PLENTY OF DRY AIR FROM THE
LOW TO UPPER LEVELS OF THE TROPOSPHERE AHEAD OF THE FRONT IS
EXPECTED TO PRODUCE CLEAR SKIES FOR MUCH OF THIS PERIOD. A
TIGHTENING PRESSURE GRADIENT AHEAD OF THE FRONT SHOULD HELP TO
INCREASE THE WINDS OVER THE FORECAST AREA...BEGINNING FRIDAY NIGHT
AND ESPECIALLY FOR SATURDAY AND SATURDAY NIGHT. WITH MORE
WIND...AS WELL AS PRECIPITABLE WATER VALUES PROGGED TO CLIMB TO
AROUND 0.5 INCHES... ANTICIPATE WARMER LOWS FOR FRIDAY NIGHT AND
THUS LITTLE CONCERN FOR FOG OR FROST. 850MB TEMPS OF 8-10C ON
FRIDAY SHOULD ALLOW FOR HIGHS IN THE LOWER 70S. ON SATURDAY...
THOSE 850MB TEMPS CLIMB TO 11-13C AND WITH THE INCREASING
SOUTHWEST WIND...TEMPERATURES SHOULD TOP OUT IN THE MID TO UPPER
70S. A FEW LOCATIONS MAY EVEN REACH 80. MAY HAVE TO WATCH FIRE
WEATHER CONDITIONS FOR SATURDAY. SEE FIRE WEATHER DISCUSSION
BELOW. EVEN WARMER LOWS EXPECTED SATURDAY NIGHT WITH A SOUTHWEST
BREEZE CONTINUING...THOUGH THE DRY AIR LIKELY ALLOWING SOME OF THE
TYPICAL COLD SPOTS TO DROP INTO THE LOW TO MID 40S.
.LONG TERM...SUNDAY THROUGH WEDNESDAY NIGHT
307 AM CDT THU SEP 13 2012
13.00Z ECMWF/GFS/UKMET AND GFS ENSEMBLES ARE IN EXCELLENT AGREEMENT
ON A MAJOR PATTERN SHIFT FOR THE LONG TERM PERIOD. THE 13.00Z
CANADIAN HAS THE PATTERN SHIFT TOO...BUT WILL BE DISCOUNTED AS AN
OUTLIER SINCE THE POSITION OF THE UPPER TROUGHING COME 00Z TUESDAY
AND ESPECIALLY BY 00Z WEDNESDAY DOES NOT AGREE WITH THE
AFOREMENTIONED MODELS.
ON SUNDAY...RIDGING REALLY AMPLIFIES OVER FAR WESTERN CANADA. IN
TURN...THIS FORCES A DEEPENING TROUGH DOWNSTREAM...WHICH DIGS DOWN
INTO THE NORTHERN PLAINS SUNDAY NIGHT. THIS TROUGH DIGGING DOWN
SHOULD HELP PUSH EASTWARD THE COLD FRONT THAT WAS OVER SOUTH DAKOTA
12Z SUNDAY. IT APPEARS THE FRONT WILL CROSS THE FORECAST AREA SUNDAY
NIGHT. PRIOR TO THE FRONTAL PASSAGE...SUNDAY SHOULD BE ANOTHER WARM
DAY WITH 850MB TEMPS OF 12-14C AND PLENTY OF SUN. HIGHS ARE LIKELY
TO BE EQUAL TO OR SLIGHTLY HIGHER THAN SATURDAY. ANOTHER
FRONTOGENETIC BAND OF PRECIPITATION LOOKS TO DEVELOP ON THE COOL
SIDE OF THE FRONT. THEREFORE...40-60 PERCENT CHANCES OF PRECIPITATION
EXIST ACROSS THE FORECAST AREA FOR BOTH SUNDAY NIGHT AND MONDAY.
FUTURE SHIFTS MAY BE ABLE TO INCREASE THESE MORE. ADDED A LOW
CHANCE OF THUNDER AS WELL GIVEN MUCAPE FORECASTS OF 300 J/KG OR SO
WITH THE FRONTOGENESIS BAND. THE UPPER TROUGH LOOKS TO DIG INTO
THE AREA FOR MONDAY NIGHT AND TUESDAY. COMBINATION OF COOL
TEMPERATURES ALOFT AND ANY SHORTWAVES MOVING THROUGH THE TROUGH
RESULTS IN THE NEED TO MAINTAIN 20-30 PERCENT CHANCES DURING THIS
TIME FRAME. A BRIEF BREAK IN PRECIPITATION IS ANTICIPATED TUESDAY
NIGHT...THEN MODELS HAVE ANOTHER POTENT SHORTWAVE DROPPING DOWN
INTO THE NORTHERN PLAINS ON WEDNESDAY. SOME WARM ADVECTION AND
DPVA FORCED PRECIPITATION IS POSSIBLE AHEAD OF IT...THOUGH
AVAILABLE MOISTURE IS A QUESTION MARK...THUS CONSENSUS 20 PERCENT
CHANCES ARE WARRANTED.
AS THE UPPER TROUGH DROPS INTO THE AREA ON MONDAY...850MB TEMPS
REALLY TUMBLE. BY 00Z TUESDAY...THEY ARE FORECAST DOWN TO AT LEAST
3-6C AND MAY EVEN FALL A LITTLE MORE...ESPECIALLY AS WE HEAD TO 12Z
TUESDAY. AS A RESULT...BOTH MONDAY AND TUESDAY LOOK CHILLY WITH
HIGHS IN THE 60S MONDAY AND 50S TUESDAY. 850MB TEMPS SHOULD WARM
BACK UP TUESDAY NIGHT INTO WEDNESDAY...PERHAPS PEAKING AS HIGH AS
8-11C PER 13.00Z ECMWF...IN RESPONSE TO THE NEXT POTENT SHORTWAVE
DROPPING THROUGH THE TROUGH. THEREFORE...HIGHS SHOULD CLIMB BACK
INTO THE 60S FOR WEDNESDAY.
FOR THOSE LOOKING FARTHER OUT...IT APPEARS THE MEAN UPPER TROUGHING
WILL STAY IN PLACE AND PERHAPS EVEN AMPLIFY THROUGH THE END OF NEXT
WEEK...PER THE 13.00Z ECMWF/GFS. THIS IS ALSO IN GOOD AGREEMENT WITH
THE 12.00Z CFS WHICH HAS BEEN SHOWING A CONSISTENT SIGNAL OF
BELOW NORMAL TEMPERATURES FOR THE LATTER HALF OF SEPTEMBER OVER
THE CENTRAL AND EASTERN PORTION OF THE U.S.
&&
.AVIATION...THROUGH 06Z FRIDAY
1146 PM CDT WED SEP 12 2012
BAND OF POST FRONT RAINS CONTINUES ACROSS THE AREA WITH VFR
CONDITIONS. EXPECT THIS RAIN TO REMAIN OVER THE AREA FOR MUCH OF
THE NIGHT AS A WEAK SHORT WAVE TROUGH COMING OUT OF NEBRASKA HOLDS
THE FRONT AND THE FRONTOGENESIS IN PLACE. ONCE THIS WAVE CLEARS
THE AREA EARLY THURSDAY MORNING...EXPECT THE RAIN WILL END AROUND
12Z. LITTLE CHANGE IN CONDITIONS EXPECTED TO OCCUR WHILE IT IS
RAINING WITH JUST AN OUTSIDE CHANCE AT SOME MVFR CONDITIONS. SKIES
SHOULD CLEAR OUT THURSDAY AFTERNOON AS HIGH PRESSURE BUILDS INTO
THE AREA. THE 13.00Z NAM CONTINUES THE TREND OF SHOWING DEEP MIXING
OCCURRING THURSDAY AFTERNOON WITH THE HIGH. WINDS STILL LOOK TO BE
FAIRLY UNIFORM IN THE MIXED LAYER WITH SUSTAINED SPEEDS AROUND 10
TO 12 KNOTS. COULD BE SOME SLIGHTLY HIGHER GUSTS AND HAVE INCLUDED
THIS POSSIBILITY FOR KRST. THE WINDS SHOULD RAPIDLY DIMINISH NEAR
SUNSET AND WITH THE CLEAR SKIES...COULD BE A VALLEY FOG NIGHT
SETTING UP FOR KLSE. WILL HAVE TO SEE HOW MUCH MIXING OCCURS
THURSDAY AFTERNOON AND HOW BIG THE TEMP/DEW POINT SPREADS BECOME
BEFORE COMMITTING TO SOME FOG.
&&
.FIRE WEATHER...FRIDAY AND SATURDAY
307 AM CDT THU SEP 13 2012
ON FRIDAY...HIGH PRESSURE OVERHEAD COMBINED WITH PLENTY OF DRY AIR
WILL RESULT IN RELATIVE HUMIDITY VALUES DROPPING TO AROUND 25
PERCENT ACROSS MUCH OF THE AREA. RECENT RAINS PLUS WINDS LESS THAN
10 MPH SHOULD PRECLUDE ANY FIRE WEATHER CONCERNS...THOUGH THE DRY
AIR AND FULL SUNSHINE WILL HELP TO DRY OUT FUELS.
ON SATURDAY...THE COMBINATION OF SOUTHWEST WINDS INCREASE TO 10 TO
15 MPH WITH HIGHER GUSTS...ALONG WITH PLENTY OF DRY AIR IN THE
ATMOSPHERE ALLOWING FOR GOOD MIXING SHOULD SEND RELATIVE HUMIDITY
VALUES PLUMMETING TO 25 TO 30 PERCENT IN THE AFTERNOON. LOWEST
RELATIVE HUMIDITY VALUES AND HIGHEST WINDS LOOK TO OCCUR WEST OF THE
MISSISSIPPI RIVER. IN ADDITION...HIGH TEMPERATURES ARE EXPECTED TO
TOP OUT IN THE MID TO UPPER 70S. WILL HAVE TO WAIT AND SEE HOW MUCH
THE FUELS DRY OUT OVER THE NEXT TWO DAYS...BUT AT LEAST WEATHER WISE
THERE IS SOME CONCERN FOR INCREASED WILDFIRE POTENTIAL. THE CONCERN
WOULD ONLY INCREASE WITH A LITTLE MORE WIND AND/OR LOWER RELATIVE
HUMIDITY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
307 AM CDT THU SEP 13 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS NEW YORK NY
438 AM EDT SAT SEP 15 2012
.SYNOPSIS...
A COLD FRONT WILL PASS THIS MORNING...ALLOWING HIGH PRESSURE TO
BUILD IN THROUGH THE REMAINDER OF THE WEEKEND. AS THE HIGH MOVES
SLOWLY OFF THE COAST MONDAY...AN INTENSIFYING LOW PRESSURE SYSTEM
WILL MOVE NORTHEAST AND MERGE WITH A COLD FRONT AS IT PASSES OVER
THE REGION TUESDAY NIGHT. HIGH PRESSURE WILL MOVE EAST ACROSS THE
AREA WEDNESDAY THROUGH THURSDAY FOLLOWED BY A COLD FRONT LATE
FRIDAY.
&&
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
COLD FRONT AT 3AM STRETCHED FROM NEAR KDXR THRU THE CITY. THE SHRA
WERE POST FRONTAL ASSOCIATED WITH THE MID LVL FORCING...AND ONLY
INTO NWRN ORANGE COUNTY. PCPN IS HOLDING TOGETHER...SO FOLLOWED
THE HRRR FOR NEAR TERM LIKELY POPS.
&&
.SHORT TERM /7 AM THIS MORNING THROUGH MONDAY NIGHT/...
SHRA IN ASSOCIATION WITH H7 MOISTURE AXIS WILL EXIT EWD THRU THE
MRNG HOURS. THE HRRR WAS FOLLOWED CLOSELY FOR POPS. BEST DYNAMICS
REMAIN TO THE N...SO LGT TO MDT RAIN RATES CAN BE EXPECTED.
MIDWEST HIPRES WILL THEN BUILD INTO THE REGION FOR THE REMAINDER
OF THE WEEKEND. SKIES WILL THEREFORE REMAIN MAINLY CLEAR THRU THE
PERIOD. TEMPS A BLEND OF THE MET/MAV.
THE HIGH DRIFTS OFFSHORE ON MON...RESULTING IN DEVELOPING RETURN
FLOW. 00Z MODELS SUPPORT THE CURRENT FCST OF DRY. THERE SHOULD BE
SOME INCREASING HIGH AND POTENTIALLY MID CLOUD COVER FROM THE SW.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
POTENTIAL FOR A SIGNIFICANT STORM TUESDAY THROUGH TUESDAY NIGHT.
00Z MODELS SHOW NO DEVIATION FROM THE STORMY SOLN. TABLE IS SET
SO NO SIGNIFICANT CHANGES WERE MADE TO THE EXTENDED.
FORECAST MODELS SHOW A SHORT WAVE OVER THE SOUTH CENTRAL U.S.
MOVING NE AND AN AMPLIFYING SHORT WAVE MOVING SE TOWARD THE GREAT
LAKES THAT PHASE TOGETHER PRODUCING A FULL AMPLITUDE TROUGH THAT
BECOMES NEGATIVELY TITLED BY TUESDAY NIGHT.
ALTHOUGH THERE ARE ALWAYS DIFFERENCES IN EXACTLY WHERE THE LOW
LEVEL LOW PRES SYSTEM DEVELOPS ALONG WITH ITS AMPLIFICATION AND
SUBSEQUENT TRACK...THERE ARE GROWING SIGNALS OF AN INTENSIFYING
LOW PRES SYSTEM MOVING TO THE N-NE AND PASSING JUST WEST OF THE
AREA LATE TUESDAY.
POTENTIAL IMPACTS ASSOCIATED WITH THIS SYSTEM WOULD INCLUDE SEVERE
TSTMS WITH ISOLATED TORNADOES...FLASH FLOOD PRODUCING
RAINFALL...STRONG GRADIENT WINDS AND COASTAL FLOODING.
AN OUTLOOK FOR THIS STORM WILL BE ISSUED WITH THIS FCST UPDATE.
STAY TUNED.
FAIR WEATHER WILL RETURN ON WEDNESDAY AS HIGH PRESSURE MOVES
TOWARD THE AREA WHICH IS FORECAST TO CONTINUE ON THURSDAY.
&&
.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
A COLD FRONT CONTINUES TO MOVE EAST AND AT 08Z WAS THROUGH THE
LOWER HUDSON VALLEY AND NYC. THE FRONT IS EXPECTED TO BE EAST OF THE
REGION BY 12Z TONIGHT.
VFR. S-SW FLOW AT 10 KT OR LESS WILL SHIFT TO THE NW AND BECOME
GUSTY BEHIND THE COLD FRONT.
AREAS OF LIGHT SHOWERS MOVING THROUGH THE LOWER HUDSON VALLY AND
INTO NORTHEASTERN NEW JERSEY CONTINUES TO BE LIGHT AND MAY WEAKEN AS
THE AREA SHIFTS EAST WITH THE BETTER FORCING TO THE NORTH. MVFR
CEILINGS WERE OBSERVED IN SOUTHERN CONNECTICUT BUT ARE NOT EXPECTED
AT THE TERMINALS.
NW WINDS INCREASE WITH GUSTS AROUND 20 KT IN THE MORNING. SOME
UNCERTAINTY WITH HOW STRONG WINDS ARE IN THE LOW LEVELS DURING THE
AFTN...BUT THERE IS THE POTENTIAL FOR OCCASIONAL GUSTS AROUND 20 KT
TO CONTINUE THROUGH THE AFTN AS WELL. DUE TO LOWER CONFIDENCE...HAVE
NOT INCLUDED THIS IN THE TAFS.
OUTLOOK FOR 06Z SUNDAY THROUGH WEDNESDAY...
.SATURDAY NIGHT-MONDAY AFTERNOON...VFR.
.MONDAY NIGHT-TUESDAY NIGHT...IFR/MVFR CONDITIONS WITH WIDESPREAD
SHOWERS AHEAD OF AN APPROACHING WARM FRONT FOLLOWED BY A COLD FRONT.
.WEDNESDAY...CLEARING CONDITIONS AS HIGH PRESSURE BUILDS IN BEHIND
THE COLD FRONT.
&&
.MARINE...
A COLD FRONT MOVES ACROSS THE FORECAST WATERS EARLY THIS MORNING
WITH WINDS SHIFTING TO THE NORTH TO NORTHWEST BEHIND THE FRONT. THIS
AFTERNOON THE FRONT WILL MOVE SLOWLY ONCE IT MOVES EAST OF THE
FORECAST WATERS AND WINDS MAY GUST OCCASIONALLY TO 25 KT ON THE
EASTERN OCEAN WATERS WITH SEAS COMING UP TO CLOSE TO 5 FT LATE THIS
AFTERNOON INTO EARLY THIS EVENING. HIGH PRESSURE BUILDS INTO THE
WATERS LATE THIS AFTERNOON INTO SUNDAY AND WINDS AND SEAS WILL
REMAIN BELOW SMALL CRAFT LEVELS.
&&
.HYDROLOGY...
NO SIGNIFICANT PRECIPITATION IS EXPECTED INTO MONDAY.
MONDAY NIGHT THROUGH TUESDAY NIGHT...THERE IS A POTENTIAL FOR A
WIDESPREAD HEAVY RAINFALL FROM 1 TO 3 INCHES WITH ISOLATED AMOUNTS
OF 4 INCHES LEADING TO MINOR URBAN POOR DRAINAGE FLOODING.
ISOLATED URBAN FLASH FLOODING CANNOT BE RULED OUT. STAY TUNED.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JMC/GC
NEAR TERM...JMC
SHORT TERM...JMC
LONG TERM...JMC/GC
AVIATION...MET
MARINE...MET
HYDROLOGY...JMC/GC
AREA FORECAST DISCUSSION
NWS NEW YORK NY
327 AM EDT SAT SEP 15 2012
.SYNOPSIS...
A COLD FRONT WILL PASS THIS MORNING...ALLOWING HIGH PRESSURE TO
BUILD IN THROUGH THE REMAINDER OF THE WEEKEND. AS THE HIGH MOVES
SLOWLY OFF THE COAST MONDAY...AN INTENSIFYING LOW PRESSURE SYSTEM
WILL MOVE NORTHEAST AND MERGE WITH A COLD FRONT AS IT PASSES OVER
THE REGION TUESDAY NIGHT. HIGH PRESSURE WILL MOVE EAST ACROSS THE
AREA WEDNESDAY THROUGH THURSDAY FOLLOWED BY A COLD FRONT LATE
FRIDAY.
&&
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
COLD FRONT AT 3AM STRETCHED FROM NEAR KDXR THRU THE CITY. THE SHRA
WERE POST FRONTAL ASSOCIATED WITH THE MID LVL FORCING...AND ONLY
INTO NWRN ORANGE COUNTY. PCPN IS HOLDING TOGETHER...SO FOLLOWED
THE HRRR FOR NEAR TERM LIKELY POPS.
&&
.SHORT TERM /7 AM THIS MORNING THROUGH MONDAY NIGHT/...
SHRA IN ASSOCIATION WITH H7 MOISTURE AXIS WILL EXIT EWD THRU THE
MRNG HOURS. THE HRRR WAS FOLLOWED CLOSELY FOR POPS. BEST DYNAMICS
REMAIN TO THE N...SO LGT TO MDT RAIN RATES CAN BE EXPECTED.
MIDWEST HIPRES WILL THEN BUILD INTO THE REGION FOR THE REMAINDER
OF THE WEEKEND. SKIES WILL THEREFORE REMAIN MAINLY CLEAR THRU THE
PERIOD. TEMPS A BLEND OF THE MET/MAV.
THE HIGH DRIFTS OFFSHORE ON MON...RESULTING IN DEVELOPING RETURN
FLOW. 00Z MODELS SUPPORT THE CURRENT FCST OF DRY. THERE SHOULD BE
SOME INCREASING HIGH AND POTENTIALLY MID CLOUD COVER FROM THE SW.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
POTENTIAL FOR A SIGNIFICANT STORM TUESDAY THROUGH TUESDAY NIGHT.
00Z MODELS SHOW NO DEVIATION FROM THE STORMY SOLN. TABLE IS SET
SO NO SIGNIFICANT CHANGES WERE MADE TO THE EXTENDED.
FORECAST MODELS SHOW A SHORT WAVE OVER THE SOUTH CENTRAL U.S.
MOVING NE AND AN AMPLIFYING SHORT WAVE MOVING SE TOWARD THE GREAT
LAKES THAT PHASE TOGETHER PRODUCING A FULL AMPLITUDE TROUGH THAT
BECOMES NEGATIVELY TITLED BY TUESDAY NIGHT.
ALTHOUGH THERE ARE ALWAYS DIFFERENCES IN EXACTLY WHERE THE LOW
LEVEL LOW PRES SYSTEM DEVELOPS ALONG WITH ITS AMPLIFICATION AND
SUBSEQUENT TRACK...THERE ARE GROWING SIGNALS OF AN INTENSIFYING
LOW PRES SYSTEM MOVING TO THE N-NE AND PASSING JUST WEST OF THE
AREA LATE TUESDAY.
POTENTIAL IMPACTS ASSOCIATED WITH THIS SYSTEM WOULD INCLUDE SEVERE
TSTMS WITH ISOLATED TORNADOES...FLASH FLOOD PRODUCING
RAINFALL...STRONG GRADIENT WINDS AND COASTAL FLOODING.
AN OUTLOOK FOR THIS STORM WILL BE ISSUED WITH THIS FCST UPDATE.
STAY TUNED.
FAIR WEATHER WILL RETURN ON WEDNESDAY AS HIGH PRESSURE MOVES
TOWARD THE AREA WHICH IS FORECAST TO CONTINUE ON THURSDAY.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
A COLD FRONT APPROACHING FROM THE WEST WILL PASS THROUGH
THE TERMINALS BETWEEN 06Z AND 12Z TONIGHT.
VFR. S-SW FLOW AT 10 KT OR LESS WILL SHIFT TO THE W AND
EVENTUALLY NW BEHIND THE COLD FRONT.
MODELS CONTINUE TO INDICATE THAT THE SHOWERS OVER EASTERN PA WILL
WEAKEN AS THEY MOVE EAST WITH THE BETTER FORCING LIFTING TO THE N
OF THE AREA. HAVE KEPT TEMPO AT KSWF BETWEEN 07Z AND 09Z WHERE A
LIGHT SHOWER MAY BE ABLE TO HOLD TOGETHER. OTHERWISE...WET RUNWAYS
NOT EXPECTED AT REMAINDER OF TERMINALS.
NW WINDS INCREASE WITH GUSTS AROUND 20 KT IN THE MORNING. SOME
UNCERTAINTY WITH HOW STRONG WINDS ARE IN THE LOW LEVELS DURING THE
AFTN...BUT THERE IS THE POTENTIAL FOR OCCASIONAL GUSTS AROUND 20
KT TO CONTINUE THROUGH THE AFTN AS WELL. DUE TO LOWER
CONFIDENCE...HAVE NOT INCLUDED THIS IN THE TAFS.
OUTLOOK FOR 06Z SUNDAY THROUGH WEDNESDAY...
.SATURDAY NIGHT-MONDAY AFTERNOON...VFR.
.MONDAY NIGHT-TUESDAY NIGHT...IFR/MVFR CONDITIONS WITH WIDESPREAD
SHOWERS AHEAD OF AN APPROACHING WARM FRONT FOLLOWED BY A COLD FRONT.
.WEDNESDAY...CLEARING CONDITIONS AS HIGH PRESSURE BUILDS IN BEHIND
THE COLD FRONT.
&&
.MARINE...
A COLD FRONT MOVES ACROSS THE FORECAST WATERS EARLY THIS MORNING
WITH WINDS SHIFTING TO THE NORTH TO NORTHWEST BEHIND THE FRONT. THIS
AFTERNOON THE FRONT WILL MOVE SLOWLY ONCE IT MOVES EAST OF THE
FORECAST WATERS AND WINDS MAY GUST OCCASIONALLY TO 25 KT ON THE
EASTERN OCEAN WATERS WITH SEAS COMING UP TO CLOSE TO 5 FT LATE THIS
AFTERNOON INTO EARLY THIS EVENING. HIGH PRESSURE BUILDS INTO THE
WATERS LATE THIS AFTERNOON INTO SUNDAY AND WINDS AND SEAS WILL
REMAIN BELOW SMALL CRAFT LEVELS.
&&
.HYDROLOGY...
NO SIGNIFICANT PRECIPITATION IS EXPECTED INTO MONDAY.
MONDAY NIGHT THROUGH TUESDAY NIGHT...THERE IS A POTENTIAL FOR A
WIDESPREAD HEAVY RAINFALL FROM 1 TO 3 INCHES WITH ISOLATED AMOUNTS
OF 4 INCHES LEADING TO MINOR URBAN POOR DRAINAGE FLOODING.
ISOLATED URBAN FLASH FLOODING CANNOT BE RULED OUT. STAY TUNED.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JMC/GC
NEAR TERM...JMC
SHORT TERM...JMC
LONG TERM...JMC/GC
AVIATION...MET
MARINE...MET
HYDROLOGY...JMC/GC
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
201 AM EDT SAT SEP 15 2012
.SYNOPSIS...
DRY CONDITIONS AND SEASONABLE TEMPERATURES WILL CONTINUE AS HIGH
PRESSURE REMAINS ACROSS THE MID ATLANTIC THROUGH TONIGHT. A
WEAK COLD FRONT WILL TRACK ACROSS THE AREA SATURDAY MORNING. HIGH
PRESSURE WILL RETURN SUNDAY BEFORE UNSETTLED WEATHER EARLY NEXT
WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
OVERALL A PRETTY QUIET EVENING OVER SE VA. HAVE SOME MID TO HIGH
LEVEL CLOUDS FROM NE NC THROUGH THE WESTERN SHORE OF THE CHES BAY
AND UP THE DELMARVA. THESE CLOUDS WILL CONTINUE TO SLIDE EWD
TONIGHT AS A COLD FRONT APPROACHES FROM THE NE. THE COLD FRONT AT
1Z STRETCHES FROM NR IPT TO KW99 TO JKL. THE FRONT WILL CONTINUE
TO SLIDE SE...BUT AHEAD OF IT...THE SKY WILL REMAIN CLEAR AS THE
FRONT IS AN ANAFRONT. ONCE THE FRONT PASSES...WILL SEE SOME MID
LEVEL CLOUD COVER MOVING THROUGH. THE LIFT BEHIND THE FRONT IS
WEAK SO NOT ANTICIPATING ANY SHOWERS WITH THE FRONT. SO HAVE TWEAK
THE SKY COVER TO SHOW THE CLEARING EXPECTED AHEAD OF THE FRONT.
HAVE ALSO TWEAKED THE OVERNIGHT LOWS...GIVING THE TEMPS A LITTLE
BOOST DUE TO THE CURRENT DEWPOINT READINGS AND EXPECTATION OF SOME
CONTINUED SRLY FLOW IN ADVANCE OF THE FRONT. DO NOT EXPECT THE
COOLER CONDITIONS BEHIND THE FRONT TO ARRIVE UNTIL LATER ON
SATURDAY SO SHOULD NOT SEE A BIG TEMP DROP IMMEDIATELY BEHIND THE
FRONT DUE TO THE CLOUDS THAT WILL ARRIVE.
PREV DISCUSSION...
A TOUCH MORE HUMID ACRS THE FA THIS AFTN AS COMPARED TO PAST FEW.
SFC HI PRES CONTS TO WEAKEN THROUGH THE EVE HRS...WHILE CDFNT
APPROACHES FM THE NW. SO FAR...LTL MOVEMENT (N) NOTED ON SCT SHRAS
OVR ECNTRL NC THIS AFTN...17Z/14 RUC KEEPS THOSE SHRAS GENLY FM
ALBEMARLE SND ON S...OTRW XPCG CLR-PCLDY WX E...AND P/MCLDY W.
PCPN CURRENTLY ASSOCIATED W/ THE CDFNT HAS CONTD TO
DIMINISH...APRS THAT HIGHEST PROB FOR ANY SHRAS AND MOST
WIDESPREAD CLDNS WILL RMN NNW OF THE FA THROUGH TNGT. CDFNT TO
PRESS INTO THE CNTRL PORTION OF FA BY 12Z/15. WILL HAVE POPS AOB
14% OVR THE FA OVRNGT.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
CDFNT PRESSES S AND E OF THE FA DURG SAT MRNG...W/ ASSOCIATED
WINDSHIFT TO THE N AS SFC HI PRES BUILDS EWD INTO THE ERN LAKES
RGN. FM SAT NGT THROUGH SUN...S/W MOVG INTO THE LWR MS
VALLEY...AND IN COMBINATION W/ STALLED FNTL BNDRY ACRSS THE
CAROLINAS...THERE WILL BE INCRSD COVERAGE OF CLDNS AND RAINFALL
(FM THE SRN MTNS THROUGH THE TN VLY AND LWR MS VLY. BY SUN
AFTN/EVE...CLDNS AND PCPN MAY BRUSH FAR SSW AREAS OF FA...OTRW SFC
HI PRES RMNS OVR THE RGN...PROVIDING DRY/NR SEASONABLE CONDS.
HI PRES TO BECOME SITUATED OFF THE E CST SUN NGT THROUGH MON...W/
TROUGH ALOFT DIGGING THROUGH THE MIDWEST. AT THE SAME TIME...S/W
WILL BE MOVG E THROUGH THE LWR MS VLY/SE STATES. MDLS GENLY AGREE
W/ INCRSG LLVL/MOIST FLO INTO THE MDATLC STATES...ESP ON
MON...BRINGING A MDT/HI PROB FOR RAINFALL. HI CHCS FOR MON TO BE
CONFINED TO INTR SECTIONS OF FA.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MEDIUM RANGE PERIOD BEGINS WITH SOUTHERN STREAM SHORTWAVE TROUGH
LIFTING NORTHEAST OUT OF THE DEEP SOUTH TOWARDS THE REGION... JUST
AHEAD OF THE NRN STREAM TROUGH POISED TO MOVE ACROSS THE MOUNTAINS
THROUGH TUESDAY. THE MODELS CONTINUE TO HANDLE THE UPPER TROUGH
SIMILARLY, WITH LLVL S WINDS STREAMING MOISTURE-RICH GULF MOISTURE
INTO THE REGION MONDAY NIGHT AND TUESDAY. PROGGED PW AND OMEGA
FIELDS INDICATE THAT OVERRUNNING MOISTURE SHOULD BE STRONG ENOUGH
TO WARRANT 50-60 POP FOR MONDAY NIGHT AND TUESDAY. FRONT APPROACHES
THE REGION TUESDAY NIGHT, WITH THE FRONT LKLY TO CLEAR THE REGION
WEDNESDAY. LOW/MIDLVL FLOW BECOMES W/NW WITH RESULTANT DOWNSLOPE
FLOW SUFFICIENT TO BRING A DRY FORECAST FOR THE LATTER HALF OF THE
WEEK AHEAD.
FOR TEMPERATURES...EXPECT MAXIMA TO AVERAGE NEAR TO JUST BELOW CLIMO
NORMAL FOR THE PERIOD. HIGHS GENERALLY INTO THE 70S TO NR 80. LOWS
IN THE 60S TO NR 70 TUESDAY MORNING...FALLING BACK INTO THE 50S AND
60S TOWARDS THE MIDDLE OF NEXT WEEK, WITH SOME EARLY MORNING LOWS IN
THE UPPER 40S POSSIBLE TOWARDS LATE NEXT WEEK WEST OF RIC.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
A WEAK COLD FRONT WILL APPROACH FROM THE THE NW AND MOVE THROUGH
THE TAF SITES BETWEEN 10-15Z LATER THIS MORNING. PATCHY FOG
SHOWING UP IN SOME OF THE AREA...BUT NOT AFFECTING TAF SITES AS OF
YET. IN GENERAL LOOKS LIKE LIGHT SSW FLOW AHEAD OF THE FRONT WILL
INHIBIT FOG FORMATION EARLY THIS MORNING...ALTHOUGH DECIDED TO ADD
A TEMPO GROUP AT KECG WHERE FRONT WILL BE DELAYED BY SEVERAL HRS
KEEPING NEAR CALM WINDS AND SLIGHTLY MORE MOIST AIRMASS IN PLACE
THROUGH 12Z.
OTHERWISE...NORTHERLY WINDS BECOME GUSTY TO 15-20 KT BETWEEN
12-18Z IN THE WAKE OF THE FRONT WITH GOOD MIXING. WINDS AND
GUSTINESS SLOWLY SUBSIDE THROUGH THE AFTN HRS AS HIGH PRESSURE
BUILDS IN FROM THE N. QUIET CONDITIONS PREVAIL TONIGHT/SUN.
SE FLOW WILL BRING INCREASING MOISTURE BY MON...WITH PERIODS OF PRECIP
AND LWR CIGS/VSBYS MON AFTN THROUGH TUE.
&&
.MARINE...
SSW FLOW PERSISTS EARLY THIS MORNING AHEAD OF A COLD FRONT. SEAS
RUNNING 2-3 FT NEAR SHORE (1-2FT BAY/SND). UPSTREAM OBS AND LATEST
MODEL DATA CONTINUE TO SUPPORT A COLD SURGE/SCA EVENT OVER THE
CHES BAY AND RIVERS LATER THIS MORNING INTO THE AFTN AND SCA HAS
BEEN HOISTED FOR SATURDAY OVER THE CHES BAY AND RIVERS. WINDS
DIMINISH WITH SLACKENING GRADIENT THIS AFTN AND EVENING. HOWEVER,
SEAS OVER WATERS LOOK TO REMAIN IN 3-4 FT RANGE DUE TO INCOMING
E-SE SWELL (15-20 SEC) ARRIVING ALONG THE MID- ATLANTIC COAST
BEGINNING THIS EVENING THROUGH SUNDAY FROM DISTANT TROP STORM
NADINE (WHICH IS ORIENTED WELL E/SE OF BERMUDA). THESE SWELLS WILL
ALSO LIKELY RESULT IN CONTINUED ELEVATED RIP THREAT THROUGH THE
WEEKEND.
N-NW WINDS CONTINUE TO DIMINISH SAT NIGHT/SUN AS SFC HIGH PRESSURE
SLIDES OVERHEAD. SFC RIDGE IS EXPECTED TO SLIDE OFF THE COAST LATER
SUN THRU MON. A WARM FRONT THEN LIFTS ACROSS THE AREA DURING MON/MON
NGT...WITH S-SE FLOW INCREASING TO 15 KT MON-TUE. TIGHTENING PRESSURE
GRADIENT MAY LEAD TO SCA CONDITIONS IN S/SE FLOW MON NGT/TUE/TUE
NGT (APPEARS LIKELY DUE TO 5 FT+ SEAS FOR COAST).
&&
.EQUIPMENT...
AT SBY...NORMAL ASOS COMMS REMAIN DOWN AND ARE EXPECTED TO STAY DOWN
FOR SEVERAL DAYS. OBS ARE BEING SENT BY THE TOWER BUT THESE UPDATES
MAY NOT BE RELIABLE SO AMD NOT SKED WILL CONTINUE TO APPEAR IN THE
TAFS.
COMMS WITH ORF ASOS HAVE BEEN RESTORED.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO 6 PM EDT THIS
EVENING FOR ANZ630>632-634>638.
&&
$$
SYNOPSIS...ALB/SAM
NEAR TERM...ALB/ESS
SHORT TERM...ALB
LONG TERM...MAM
AVIATION...LKB
MARINE...LKB/MAM
EQUIPMENT...AKQ
AREA FORECAST DISCUSSION
NWS GAYLORD MI
408 AM EDT SAT SEP 15 2012
.SYNOPSIS...
ISSUED AT 341 AM EDT SAT SEP 15 2012
OUTSTANDING WEATHER IS EXPECTED THIS WEEKEND AS HIGH PRESSURE SLIDES
ACROSS THE GREAT LAKES. THE NEXT COLD FRONT WILL MOVE THROUGH ON
MONDAY...BRINGING THE NEXT CHANCE OF RAIN. LAKE EFFECT RAIN SHOWERS
MAY DEVELOP TUESDAY...AS MUCH COOLER AIR INVADES THE REGION.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 341 AM EDT SAT SEP 15 2012
SHARP UPPER TROUGH WORKING INTO NEW ENGLAND WITH A SOLID NW FLOW
ALOFT OVER NRN MICHIGAN. ATMOSPHERIC SUBSIDENCE WITH DRY AIR
ADVECTION WITHIN ADVANCING SFC HIGH PRESSURE. STILL...VERY GOOD
OVERLAKE INSTABILITY HAS LED TO THE DEVELOPMENT OF STRATO CU IN
BACKING NW-W 1000-850MB FLOW...ATTACHED TO GREEN BAY. WINDS ARE
WEAKENING WITH TIME...SO FETCH AND INLAND PENETRATION WILL
CONTINUE LEAD TO LESS CLOUD...BUT THIS MAY TAKE THROUGH EARLY
DAYBREAK...WHEN MIXING INTO DRIER AIR ALOFT CAN HELP MIX IT ALL
OUT. TEMPERATURES WERE QUITE CHILLY...DIPPING INTO THE 30S IN
SEVERAL LOCALES OF NRN LOWER. SKIES WERE FAIRLY CLEAR ACROSS
EASTERN UPPER...WITH LATEST RUC ANALYSIS SUGGESTING A WEAKER WIND
FLOW AND LESS MOISTURE FLUX OFF WHITEFISH BAY/EASTERN LAKE
SUPERIOR. CANNOT RULE OUT SOME STRATO CU INTO CHIPPEWA COUNTY
THOUGH OVER THE NEXT FEW HOURS.
TODAY AND TONIGHT...VERY QUIET. SFC HIGH PRESSURE WILL MOVE IN
OVERHEAD WITH SOME SCATTERED CUMULUS DEVELOPMENT...MAINLY ALONG
THE AXIS OF THE SFC HIGH...AND AREAS EAST. THIS BRINGS THE BETTER
CU ACROSS NE LOWER AND EASTERN CHIP/MACK. BY LATER THIS
AFTERNOON...SOME LAKE BREEZES WILL TRY TO CONSOLIDATE THIS CLOUD
MORE INLAND. THE CLOUDS WILL QUICKLY ERODE TO CLEAR SKIES IN THE
EVENING WITH ONLY SOME SCATTERED MID CLOUD POSSIBLE OVERNIGHT.
THIS WILL BE AHEAD OF A WEAK SHORTWAVE AND LOW LEVEL WARM FRONT
LIFTING OUR WAY. A 30-35KT WSW ORIENTED LLJ COULD THEORETICALLY
RESULT IN SOME THIN CLOUDINESS LATE. WOULD HEDGE MY BETS ON A
FAIRLY CLEAR EVENING THOUGH. LOW TEMPS LIKELY IN THE LOW TO MID
40S WEST/NW CWA IN BETTER SW FLOW DEVELOPING...WITH THE COLDEST
MID TO UPPER 30S IN LOW LYING AREAS OF THE EASTERN CWA OF NRN
LOWER.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 341 AM EDT SAT SEP 15 2012
HIGH PRESSURE AT THE SURFACE AND ALOFT SUNDAY IS EXPECTED TO LEAD TO
VERY PLEASANT WEATHER FOR THE LAST SUNDAY OF SUMMER (THE AUTUMNAL
EQUINOX IS EARLY SATURDAY MORNING ON SEPTEMBER 22ND). A COLD FRONT
WILL THEN MOVE ACROSS THE REGION LATER MONDAY SETTING THE STAGE FOR
LONG WAVE TROUGHING TO SETTLE INTO THE REGION FOR MUCH OF NEXT WEEK.
THIS WILL LEAD TO AN EXTENDED PERIOD OF COOLER AND UNSETTLED
WEATHER. THE MAIN LONG TERM FORECAST CONCERNS REVOLVE AROUND POPS
FOR ALL OF NEXT WEEK.
SUNDAY...SURFACE HIGH PRESSURE SHIFTS OFF TO OUR EAST WHILE UPPER
LEVEL HEIGHTS MAX/FLATTEN OUT. THIS IS EXPECTED TO LEAD TO LOTS OF
SUNSHINE AND MILD TEMPERATURES WITH HIGHS RANGING FROM THE MIDDLE
70S TO LOWER 80S.
SUNDAY NIGHT INTO MONDAY NIGHT...PARTLY CLOUDY SKIES WITH MILDER
TEMPERATURES SUNDAY NIGHT AS SOUTHWEST WINDS STAY UP A BIT. A COLD
FRONT MOVES ACROSS THE REGION LATER MONDAY LIKELY BRINGING SHOWERS.
LOWS SUNDAY NIGHT IN THE 50S WITH HIGHS ON MONDAY RANGING FROM THE
MIDDLE AND UPPER 60S NORTH TO THE MIDDLE AND UPPER 70S SOUTHEAST.
LOWS MONDAY NIGHT IN THE MIDDLE 40S TO LOWER 50S.
TUESDAY...HEIGHTS CONTINUE TO FALL AND COMBINE WITH INCREASING OVER
LAKE INSTABILITY (AS 850 MB TEMPERATURES FALL TO BETWEEN ZERO AND -2
C) AND A SHORT WAVE MOVING THROUGH THE FLOW TO PRODUCE A CHANCE OF
RAIN SHOWERS. THE MEAN FLOW APPEARS TO BE NORTH OR NORTH NORTHWEST
SO LOCALS NEAR THE LAKE SHORES WILL LIKELY HAVE THE BEST SHOT OF
RAIN. HIGHS RANGING FROM THE MUCH COOLER LOWER 50S NORTH TO AROUND
60 SOUTHEAST.
TUESDAY NIGHT...A WEDGE OF DRIER AIR IN COMBINATION WITH HIGH
PRESSURE NOSING IN FROM THE NORTH WILL SET THE STAGE FOR A VERY
CHILLY NIGHT. IF WINDS DECOUPLE...AND RIGHT NOW IT LOOKS LIKE THEY
WILL...THIS COULD LEAD TO THE FIRST SIGNIFICANT FROST OR FREEZE OF
THE SEASON.
WEDNESDAY THROUGH FRIDAY...ENERGY RIDING SOUTHEAST ON THE BACKSIDE
OF A BLOSSOMING PACIFIC RIDGE AMPLIFIES THE LONG WAVE TROUGH ACROSS
THE GREAT LAKES. SO THIS IN COMBINATION WITH PERIODIC SHORT WAVES
MOVING THROUGH THE FLOW AND INCREASING OVER LAKE INSTABILITY BRINGS
MORE CHANCES FOR RAIN SHOWERS. THE DETAILS OF WHICH WILL NEED TO BE
WORKED OUT BY FUTURE SHIFTS. HIGHS GENERALLY RANGING FROM THE MIDDLE
50S TO THE MIDDLE 60S. LOWS IN THE UPPER 30S AND 40S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 159 AM EDT SAT SEP 15 2012
NO AVIATION CONCERNS OUTSIDE THE NEXT FEW HOURS OR SO. COLD LOW
LEVEL AIR IS RESULTING IN OVERLAKE INSTABILITY AND THE DEVELOPMENT
OF MARGINAL MVFR BKN CIGS AT TVC. THIS SHOULD BE FEW AND FAR
BETWEEN AS THE AIR MASS IS ALSO DRYING WITH WEAKENING NORTHERLY
LOW LEVEL FLOW. HIGH PRESSURE AND DRY AIR CONTINUE TO SETTLE IN
OVER THE REGION TODAY AND TOMORROW FOR A QUICK PERIOD OF SCATTERED
CU...BECOMING SKC IN MBL/TVC AND LIKELY PLN/APN BY LATER IN THE
AFTERNOON WITH LAKES BREEZES. SKIES WILL BE CLEAR HEADING THROUGH
THE NIGHT...WITH ONLY SOME SCT MID CLOUD LOOKING POSSIBLE.
&&
.MARINE...
ISSUED AT 159 AM EDT SAT SEP 15 2012
DROPPED SMALL CRAFT ADVISORY ACROSS THE NE LOWER NEARSHORE WATERS
UNDER A WEAKENING LOW LEVEL WIND FIELD...WITH SUPPORT FROM LATEST
MARINE OBS. THIS DESPITE GOOD OVERLAKE INSTABILITY...BUT GUSTY
WINDS ARE LIKELY...ESPECIALLY OVER LAKE HURON. HIGH PRESSURE WILL
THEN SETTLE INTO THE REGION TODAY FOR ONSHORE LAKE BREEZES IN THE
AFTERNOON. THIS HIGH EXITS EAST TONIGHT WITH SOUTHERLY WINDS
RETURNING. THERE IS AN OUTSIDE CHANCE AT SOME LOW END ADVISORY
LEVEL WINDS IN COASTAL CONVERGENCE REGIONS FROM MANISTEE THROUGH
THE MANITOU ISLANDS. CONFIDENCE IS LOW AT THIS POINT...ESPECIALLY
WITH LOW LEVEL WARMING AND INCREASING STABILITY. THESE SAME
ADVISORY POSSIBILITIES CONTINUE THROUGH SUNDAY NIGHT IN ADVANCE OF
THE NEXT LOW PRESSURE AND COLD FRONT WHICH PASSES MONDAY.
INSTABILITY OVER THE LAKES INCREASES RELATIVELY SUBSTANTIALLY
BEHIND THIS FRONT FOR WHAT COULD VERY WELL TURN OUT TO BE THE
BETTER CHANCES FOR ADVISORIES. UNSTABLE CONDITIONS ARE EXPECTED TO
HOLD FROM MONDAY NIGHT ALL THE WAY THROUGH NEXT WORK WEEK AND
POSSIBLY NEXT WEEKEND.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
SYNOPSIS...AS
SHORT TERM...SD
LONG TERM...AS
AVIATION...SD
MARINE...SD
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
143 AM EDT SAT SEP 15 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE NORTH COUNTRY OVERNIGHT BRINGING
A CHANCE OF SHOWERS TO THE REGION. A RIDGE OF HIGH PRESSURE WILL
BUILD INTO THE REGION ON SATURDAY AND WILL REMAIN THROUGH MONDAY.
A LOW PRESSURE AREA MOVING INTO THE REGION ON TUESDAY WILL BRING
SOME HEAVY RAIN TO THE NORTH COUNTRY TUESDAY AND TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 120 AM EDT SATURDAY...MINOR UPDATE TO GOING FORECAST THIS
EARLY AM MAINLY TO ADJUST POPS FROM THE CHAMPLAIN VALLEY EASTWARD.
INITIAL PRE-FRONTAL TROUGH HAD PASSED THROUGH THE REGION WITH MAIN
COLD FRONT STILL OFF TO OUR WEST. WHAT WAS A RAGGED LINE OF
SHOWERS ACROSS NORTHERN NEW YORK HAS REDEVELOPED INTO A FAIR SHARP
LINE OF SHOWERS COMING INTO THE CHAMPLAIN VALLEY. 3KM HRRR MODEL
HAS THIS HANDLED VERY WELL...INCLUDING A BRIEF 1-2 HOUR PERIOD OF
EASTERLY WINDS AHEAD OF THE RAIN WHICH IS OCCURRING AT THE SURFACE
RIGHT NOW. HRRR HOLDS INTO HIGHER POPS EAST OF THE GREENS NOT SO
HAVE BUMPED UP A BIT FOR AT LEAST A 1 HOUR PERIOD OF LIKELY
SHOWERS. STILL NOT LOOKING AT A BUNCH OF PRECIP WITH THIS THING
THOUGH AS UPSTREAM OBS SHOWING MAINLY LESS THAN A TENTH OF AN INCH
HAS FALLEN.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH SUNDAY NIGHT/...
AS OF 433 PM EDT FRIDAY...SOME SHORTWAVES TO DROP THROUGH THE
REGION SATURDAY MORNING SO HAVE GONE WITH SLIGHT CHANCE POPS FOR
SHOWERS ACROSS THE NORTHERN ADIRONDACKS AND NORTHERN VERMONT. DEW
POINTS DROP DURING THE DAY AND BTV 4 KM MODEL NOT SHOWING ANY
SHOWER ACTIVITY DURING SATURDAY AFTERNOON. SKIES CLEARING OUT
SATURDAY NIGHT AND WILL REMAIN MOSTLY CLEAR THROUGH SUNDAY
NIGHT...AS A RIDGE OF HIGH PRESSURE WILL BE OVER THE REGION. THERE
WILL BE A FEEL OF FALL IN THE AIR SATURDAY AND SUNDAY...AS MAX
TEMPERATURES WILL BE MAINLY IN THE 60S ON BOTH DAYS. MIN
TEMPERATURES SATURDAY NIGHT AND SUNDAY NIGHT WILL BE MAINLY IN THE
30S...WITH SOME UPPER 20S IN THE ADIRONDACKS...AND TEMPERATURES
AROUND 40 IN THE CHAMPLAIN VALLEY. EXPECTING AREAS OF FROST AROUND
THE REGION LATE SATURDAY NIGHT AND EARLY SUNDAY MORNING...AND ALSO
AGAIN LATE SUNDAY NIGHT AND EARLY MONDAY MORNING. ALSO EXPECTING
SOME RADIATION FOG TO FORM OVER THE SHELTERED FOG PRONE VALLEYS OF
EASTERN AND NORTHEAST VERMONT LATE SATURDAY NIGHT AND ALSO AGAIN
LATE SUNDAY NIGHT... AS CLEAR SKIES AND NEARLY CALM WINDS WILL
PROVIDE IDEAL CONDITIONS FOR RADIATION FOG TO FORM...MAINLY IN THE
RIVER VALLEYS.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 339 PM EDT FRIDAY...LONGER RANGE GUIDANCE REMAINS IN PRETTY
DECENT AGREEMENT FOR ALL OF NEXT WEEK, SO OVERALL CONFIDENCE IN
THE FORECAST DETAILS ARE AT THE MODERATE LEVEL. DAILY DETAILS FOLLOW:
MONDAY: HIGH PRESSURE IN CONTROL BUT MOVING OFF TO THE EAST. AFTER
A COOL START, TEMPERATURES WILL MODERATE QUITE NICELY. 850MB
TEMPERATURES REACH 8-10C, WHICH SHOULD SUPPORT SURFACE
TEMPERATURES INTO THE MID 70S IN THE VALLEYS. LOTS OF SUN AS WELL.
MONDAY NIGHT: THINGS BEGIN TO CHANGE QUICKLY. A DEVELOPING STORM
OFF TO OUR WEST ASSOCIATED WITH A STRONG DIGGING TROUGH WILL TAP
INTO ABUNDANT MOISTURE DOWN IN THE SOUTHEASTERN US AND OVER THE
GULF. THAT MEANS CLOUDS WILL QUICKLY INCREASE, AND RAIN SHOULD
BEGIN TO FALL, MAINLY AFTER MIDNIGHT. WITH THE CLOUDS AND RAIN, IT
WILL BE MUCH MILDER THAN SUNDAY NIGHT, AND I WENT A BIT WARMER
THAN GFS MOS AND ALONG THE LINES OF THE 00Z ECMWF MOS GUIDANCE. IN
GENERAL, 50S TO LOW 60S FOR LOWS.
TUESDAY: GONNA BE AN INTERESTING DAY. MODELS CONTINUE TO INDICATE
A SERIOUS AMOUNT OF DYNAMICS WITH THE SYSTEM. LOOKING AT 100KTS+
AT 250MB AND EVEN A 50-60KT LOWER LEVEL JET AT 850MB. THIS WILL
NOT ONLY EASILY BRING UP ALL THAT GULF MOISTURE, BUT BE AN
EFFICIENT RAIN MAKER TOO. LATEST GUIDANCE INDICATES A WIDESPREAD 1
TO 3 INCHES OF RAIN. AT THAT AMOUNT, WE SHOULD BE FINE WITH REGARD
TO FLOOD THREAT, THOUGH SIGNIFICANT RISES WOULD OCCUR ON THE
RIVERS (ESPECIALLY IF WE SEE MORE TOTALS IN THE 3" RANGE). LATER
FORECASTS WILL MONITOR THIS THREAT.
AS MENTIONED ABOVE, WE`LL HAVE A PRETTY STRONG LOW LEVEL JET.
ALTHOUGH RIGHT NOW IT APPEARS MOST OF THAT FLOW WILL BE SOUTHERLY,
IF WE SEE THINGS TURN MORE SOUTHEASTERLY, WE`LL HAVE TO CONTEND
WITH SOME GUSTY WINDS ON THE WESTERN SLOPES OF THE GREENS. COULD
BE A LITTLE BREEZY IN THE CHAMPLAIN VALLEY THANKS TO SOME
FUNNELING OF SOUTHERLY WINDS, HOWEVER WITH ALL THE RAIN AROUND,
WE`LL HAVE A STABILIZING LAYER TO KEEP ALL THAT WIND FROM GETTING
TO THE GROUND. WENT BELOW GUIDANCE A FEW DEGREES DUE TO ALL THE
RAIN AND CLOUDS. LOTS OF PRIMARILY 60S FOR HIGHS.
INSTABILITY LOOKS MARGINAL, SO WENT PRIMARILY WITH RAIN, INSTEAD
OF SHOWERS OR THUNDER.
TUESDAY NIGHT: DEEPENING LOW PRESSURE CENTER SHOULD MOVE FROM
SOUTH TO NORTH RIGHT ACROSS THE AREA. AS IT PASSES BY TO THE NORTH
LATER AT NIGHT, WINDS WILL SWITCH TO THE WEST AND START TO PULL A
FAIRLY SIGNIFICANT COLD FRONT ACROSS THE AREA. BY DAYBREAK, WE
SHOULD HAVE A PRETTY DECENT WEST-EAST TEMPERATURE GRADIENT -- 40S
ACROSS NORTHERN NEW YORK WHILE STILL IN THE 50S IN VERMONT. RAIN
WILL TAPER OFF EARLY, BUT THEN START BACK UP AGAIN WITH THE
FRONTAL PASSAGE WITH PERHAPS SOME BRIEFLY HEAVY SHOWERS. THIS FAR
OUT, DID NOT GET CUTE -- JUST PAINTED IN LIKELY POPS FOR THE WHOLE NIGHT.
WEDNESDAY: RESIDUAL CLOUDS AND SHOWERS IN THE MORNING, OTHERWISE
CLEARING. COLD AIR ADVECTION WILL MAKE ITSELF FELT, WITH 850MB
TEMPERATURES DROPPING TO THE 2-5C RANGE BY LATE AFTERNOON. WARMEST
TEMPERATURES WILL BE IN SOUTHEASTERN VERMONT (MID 60S) WHILE
STRUGGLING TO HIT 60F IN THE ST LAWRENCE VALLEY.
THURSDAY AND FRIDAY: HIGH PRESSURE HANGS TIGHT ALONG THE EAST
COAST. SHOULD BE DRY THURSDAY, THOUGH BY FRIDAY SOME MOISTURE FROM
A SYSTEM WELL TO THE WEST MAY START TO OOZE IN, ESPECIALLY WESTERN
AREAS, DURING THE DAY. PAINTED IN LOW CHANCE POPS DUE TO
UNCERTAINTY. STAYED CLOSE TO GUIDANCE FOR TEMPERATURES, SO LOTS OF
60S THURSDAY WITH SOME MODERATION INTO THE LOWER 70S FRIDAY AS
SOUTHWEST FLOW BETWEEN THE HIGH TO THE EAST AND SYSTEM TO THE WEST
GETS ESTABLISHED.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 06Z SUNDAY...SFC COLD FRONT SWINGING THROUGH THE AREA AT
06Z TO CLEAR EAST BY 12Z. BAND OF LIGHT -SHRAS TO AFFECT VT
TERMINALS THROUGH 08Z...OTW DRY CONDS EXPECTED. VRB CIGS
ALONG/BEHIND FRONTAL BOUNDARY THROUGH 13Z WITH GENERALLY VFR
EXPECTED AT KPBG/KBTV/KRUT...OCCNL MVFR AT KMPV/KMSS...AND IFR AT
KSLK WHERE SOME PATCH -DZ AND/OR BR ALSO POSSBL. WINDS TRENDING
LIGHT TO MODERATE WEST/NORTHWESTERLY OVERNIGHT INTO
TOMORROW...WITH OCCNL GUSTS TO NEAR 20 KT IN THE 18-22Z TIME FRAME
AS CIGS TREND VFR IN ALL AREAS. SKIES TO THEN TREND SKC BY 00Z AS
WINDS ABATE TO LIGHT.
OUTLOOK 06Z SUNDAY THROUGH WEDNESDAY...
06Z SUNDAY THROUGH 00Z TUESDAY...MAINLY VFR. COULD BE LOCAL IFR IN
FOG AT KMPV/KSLK SATURDAY/SUNDAY NIGHT.
00Z TUESDAY THROUGH 12Z WEDNESDAY...MVFR AND LOCAL IFR IN PERIODS
OF RAIN.
12Z WEDNESDAY ONWARD...TRENDING TOWARD VFR.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...WGH
NEAR TERM...BANACOS
SHORT TERM...WGH
LONG TERM...NASH
AVIATION...JMG/MUCCILLI
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
120 AM EDT SAT SEP 15 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE NORTH COUNTRY OVERNIGHT BRINGING
A CHANCE OF SHOWERS TO THE REGION. A RIDGE OF HIGH PRESSURE WILL
BUILD INTO THE REGION ON SATURDAY AND WILL REMAIN THROUGH MONDAY.
A LOW PRESSURE AREA MOVING INTO THE REGION ON TUESDAY WILL BRING
SOME HEAVY RAIN TO THE NORTH COUNTRY TUESDAY AND TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 120 AM EDT SATURDAY...MINOR UPDATE TO GOING FORECAST THIS
EARLY AM MAINLY TO ADJUST POPS FROM THE CHAMPLAIN VALLEY EASTWARD.
INITIAL PRE-FRONTAL TROUGH HAD PASSED THROUGH THE REGION WITH MAIN
COLD FRONT STILL OFF TO OUR WEST. WHAT WAS A RAGGED LINE OF
SHOWERS ACROSS NORTHERN NEW YORK HAS REDEVELOPED INTO A FAIR SHARP
LINE OF SHOWERS COMING INTO THE CHAMPLAIN VALLEY. 3KM HRRR MODEL
HAS THIS HANDLED VERY WELL...INCLUDING A BRIEF 1-2 HOUR PERIOD OF
EASTERLY WINDS AHEAD OF THE RAIN WHICH IS OCCURRING AT THE SURFACE
RIGHT NOW. HRRR HOLDS INTO HIGHER POPS EAST OF THE GREENS NOT SO
HAVE BUMPED UP A BIT FOR AT LEAST A 1 HOUR PERIOD OF LIKELY
SHOWERS. STILL NOT LOOKING AT A BUNCH OF PRECIP WITH THIS THING
THOUGH AS UPSTREAM OBS SHOWING MAINLY LESS THAN A TENTH OF AN INCH
HAS FALLEN.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH SUNDAY NIGHT/...
AS OF 433 PM EDT FRIDAY...SOME SHORTWAVES TO DROP THROUGH THE
REGION SATURDAY MORNING SO HAVE GONE WITH SLIGHT CHANCE POPS FOR
SHOWERS ACROSS THE NORTHERN ADIRONDACKS AND NORTHERN VERMONT. DEW
POINTS DROP DURING THE DAY AND BTV 4 KM MODEL NOT SHOWING ANY
SHOWER ACTIVITY DURING SATURDAY AFTERNOON. SKIES CLEARING OUT
SATURDAY NIGHT AND WILL REMAIN MOSTLY CLEAR THROUGH SUNDAY
NIGHT...AS A RIDGE OF HIGH PRESSURE WILL BE OVER THE REGION. THERE
WILL BE A FEEL OF FALL IN THE AIR SATURDAY AND SUNDAY...AS MAX
TEMPERATURES WILL BE MAINLY IN THE 60S ON BOTH DAYS. MIN
TEMPERATURES SATURDAY NIGHT AND SUNDAY NIGHT WILL BE MAINLY IN THE
30S...WITH SOME UPPER 20S IN THE ADIRONDACKS...AND TEMPERATURES
AROUND 40 IN THE CHAMPLAIN VALLEY. EXPECTING AREAS OF FROST AROUND
THE REGION LATE SATURDAY NIGHT AND EARLY SUNDAY MORNING...AND ALSO
AGAIN LATE SUNDAY NIGHT AND EARLY MONDAY MORNING. ALSO EXPECTING
SOME RADIATION FOG TO FORM OVER THE SHELTERED FOG PRONE VALLEYS OF
EASTERN AND NORTHEAST VERMONT LATE SATURDAY NIGHT AND ALSO AGAIN
LATE SUNDAY NIGHT... AS CLEAR SKIES AND NEARLY CALM WINDS WILL
PROVIDE IDEAL CONDITIONS FOR RADIATION FOG TO FORM...MAINLY IN THE
RIVER VALLEYS.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 339 PM EDT FRIDAY...LONGER RANGE GUIDANCE REMAINS IN PRETTY
DECENT AGREEMENT FOR ALL OF NEXT WEEK, SO OVERALL CONFIDENCE IN
THE FORECAST DETAILS ARE AT THE MODERATE LEVEL. DAILY DETAILS FOLLOW:
MONDAY: HIGH PRESSURE IN CONTROL BUT MOVING OFF TO THE EAST. AFTER
A COOL START, TEMPERATURES WILL MODERATE QUITE NICELY. 850MB
TEMPERATURES REACH 8-10C, WHICH SHOULD SUPPORT SURFACE
TEMPERATURES INTO THE MID 70S IN THE VALLEYS. LOTS OF SUN AS WELL.
MONDAY NIGHT: THINGS BEGIN TO CHANGE QUICKLY. A DEVELOPING STORM
OFF TO OUR WEST ASSOCIATED WITH A STRONG DIGGING TROUGH WILL TAP
INTO ABUNDANT MOISTURE DOWN IN THE SOUTHEASTERN US AND OVER THE
GULF. THAT MEANS CLOUDS WILL QUICKLY INCREASE, AND RAIN SHOULD
BEGIN TO FALL, MAINLY AFTER MIDNIGHT. WITH THE CLOUDS AND RAIN, IT
WILL BE MUCH MILDER THAN SUNDAY NIGHT, AND I WENT A BIT WARMER
THAN GFS MOS AND ALONG THE LINES OF THE 00Z ECMWF MOS GUIDANCE. IN
GENERAL, 50S TO LOW 60S FOR LOWS.
TUESDAY: GONNA BE AN INTERESTING DAY. MODELS CONTINUE TO INDICATE
A SERIOUS AMOUNT OF DYNAMICS WITH THE SYSTEM. LOOKING AT 100KTS+
AT 250MB AND EVEN A 50-60KT LOWER LEVEL JET AT 850MB. THIS WILL
NOT ONLY EASILY BRING UP ALL THAT GULF MOISTURE, BUT BE AN
EFFICIENT RAIN MAKER TOO. LATEST GUIDANCE INDICATES A WIDESPREAD 1
TO 3 INCHES OF RAIN. AT THAT AMOUNT, WE SHOULD BE FINE WITH REGARD
TO FLOOD THREAT, THOUGH SIGNIFICANT RISES WOULD OCCUR ON THE
RIVERS (ESPECIALLY IF WE SEE MORE TOTALS IN THE 3" RANGE). LATER
FORECASTS WILL MONITOR THIS THREAT.
AS MENTIONED ABOVE, WE`LL HAVE A PRETTY STRONG LOW LEVEL JET.
ALTHOUGH RIGHT NOW IT APPEARS MOST OF THAT FLOW WILL BE SOUTHERLY,
IF WE SEE THINGS TURN MORE SOUTHEASTERLY, WE`LL HAVE TO CONTEND
WITH SOME GUSTY WINDS ON THE WESTERN SLOPES OF THE GREENS. COULD
BE A LITTLE BREEZY IN THE CHAMPLAIN VALLEY THANKS TO SOME
FUNNELING OF SOUTHERLY WINDS, HOWEVER WITH ALL THE RAIN AROUND,
WE`LL HAVE A STABILIZING LAYER TO KEEP ALL THAT WIND FROM GETTING
TO THE GROUND. WENT BELOW GUIDANCE A FEW DEGREES DUE TO ALL THE
RAIN AND CLOUDS. LOTS OF PRIMARILY 60S FOR HIGHS.
INSTABILITY LOOKS MARGINAL, SO WENT PRIMARILY WITH RAIN, INSTEAD
OF SHOWERS OR THUNDER.
TUESDAY NIGHT: DEEPENING LOW PRESSURE CENTER SHOULD MOVE FROM
SOUTH TO NORTH RIGHT ACROSS THE AREA. AS IT PASSES BY TO THE NORTH
LATER AT NIGHT, WINDS WILL SWITCH TO THE WEST AND START TO PULL A
FAIRLY SIGNIFICANT COLD FRONT ACROSS THE AREA. BY DAYBREAK, WE
SHOULD HAVE A PRETTY DECENT WEST-EAST TEMPERATURE GRADIENT -- 40S
ACROSS NORTHERN NEW YORK WHILE STILL IN THE 50S IN VERMONT. RAIN
WILL TAPER OFF EARLY, BUT THEN START BACK UP AGAIN WITH THE
FRONTAL PASSAGE WITH PERHAPS SOME BRIEFLY HEAVY SHOWERS. THIS FAR
OUT, DID NOT GET CUTE -- JUST PAINTED IN LIKELY POPS FOR THE WHOLE NIGHT.
WEDNESDAY: RESIDUAL CLOUDS AND SHOWERS IN THE MORNING, OTHERWISE
CLEARING. COLD AIR ADVECTION WILL MAKE ITSELF FELT, WITH 850MB
TEMPERATURES DROPPING TO THE 2-5C RANGE BY LATE AFTERNOON. WARMEST
TEMPERATURES WILL BE IN SOUTHEASTERN VERMONT (MID 60S) WHILE
STRUGGLING TO HIT 60F IN THE ST LAWRENCE VALLEY.
THURSDAY AND FRIDAY: HIGH PRESSURE HANGS TIGHT ALONG THE EAST
COAST. SHOULD BE DRY THURSDAY, THOUGH BY FRIDAY SOME MOISTURE FROM
A SYSTEM WELL TO THE WEST MAY START TO OOZE IN, ESPECIALLY WESTERN
AREAS, DURING THE DAY. PAINTED IN LOW CHANCE POPS DUE TO
UNCERTAINTY. STAYED CLOSE TO GUIDANCE FOR TEMPERATURES, SO LOTS OF
60S THURSDAY WITH SOME MODERATION INTO THE LOWER 70S FRIDAY AS
SOUTHWEST FLOW BETWEEN THE HIGH TO THE EAST AND SYSTEM TO THE WEST
GETS ESTABLISHED.
&&
.AVIATION /05Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 00Z SUNDAY...AREA OF SHOWERS AND LOW CLOUDS WILL CREATE
VFR/MVFR CONDITIONS THIS EVENING AND TONIGHT...TRENDING TO
ALL VFR ON SATURDAY. PERIODS OF SHOWERS AND POSSIBLE THUNDERSTORMS
ASSOCIATED WITH A COLD FRONT WILL PUSH THROUGH MSS/SLK THROUGH THE
EVENING WITH REDUCED VISIBILITIES AND CEILINGS. THIS ACTIVITY WILL
GRADUALLY WEAKEN AND TAPER TO MORE SCATTERED SHOWERS AS IT ENTERS
THE CHAMPLAIN VALLEY AND VERMONT. ACCOMPANYING AND FOLLOWING THIS
COLD FRONT IS AN AREA OF LOWER CLOUDS...WHICH WILL REDUCE CEILINGS
TO 1500-3000 FEET FOR A PERIOD OVERNIGHT AT ALL TAF SITES. THIS
SHOULD GRADUALLY LIFT SATURDAY MORNING AND BECOME A BROKEN DECK OF
STRATOCUMULUS WITH CEILINGS GENERALLY 3-5K FEET. EVEN WITH
RAINFALL...NOT EXPECTING MUCH IF ANY FOG TONIGHT WITH INCREASED LOW
LEVEL WIND FIELD AND FALLING DEW POINTS FOLLOWING FRONTAL PASSAGE.
WINDS TONIGHT WILL TURN FROM THE SOUTH AHEAD OF THE COLD FRONT TO
WEST/NORTHWEST BEHIND...GENERALLY 5-10 KNOTS WITH SOME GUSTS UP TO
20 KNOTS FOLLOWING PASSAGE. ON SATURDAY...WINDS REMAIN WEST-
NORTHWESTERLY 10-15 KNOTS.
OUTLOOK 00Z SUNDAY THROUGH WEDNESDAY...
00Z SUNDAY THROUGH 00Z TUESDAY...MAINLY VFR. COULD BE LOCAL IFR
IN FOG AT KMPV/KSLK SATURDAY/SUNDAY NIGHT.
00Z TUESDAY THROUGH 12Z WEDNESDAY...MVFR AND LOCAL IFR IN PERIODS
OF RAIN.
12Z WEDNESDAY ONWARD...TRENDING TOWARD VFR.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...WGH
NEAR TERM...BANACOS
SHORT TERM...WGH
LONG TERM...NASH
AVIATION...MUCCILLI/NASH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
240 AM EDT SAT SEP 15 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL DROP SOUTHWARD THROUGH NORTH CAROLINA
TODAY... THEN STALL NEAR THE SOUTH CAROLINA BORDER THROUGH SUNDAY...
BEFORE DRIFTING BACK NORTHWARD AS A WARM FRONT SUNDAY NIGHT. A
STRONG STORM SYSTEM WILL APPROACH THE AREA FROM THE SOUTHWEST MONDAY
THROUGH TUESDAY.
&&
.NEAR TERM /TODAY THROUGH SUNDAY NIGHT/...
AS OF 215 AM SATURDAY...
FOR TODAY/TONIGHT: EXPECT A FAIRLY QUIET AND SUMMER-LIKE DAY
OVERALL... BUT WITH AN INCREASE IN CLOUDS LATE. THE LATEST SURFACE
ANALYSIS SHOWS THE VERY WEAK SURFACE RIDGE CONTINUING TO LOSE ITS
GRIP ON THE AREA AHEAD OF AN INCOMING COOL FRONT... STRETCHING FROM
NEW ENGLAND ACROSS SE WV TO THE MO/AR BORDER. AS ANTICIPATED...
SURFACE DEW POINTS HAVE REBOUNDED FROM 24 HOURS AGO TO AROUND 60
WEST AND MID-UPPER 60S EAST. WITH LIGHT WINDS AND ONLY PATCHES OF
HIGH CLOUDS EARLY THIS MORNING... FOG FORMATION IS FAVORED
ESPECIALLY IN LOW-LYING AREAS AND NEAR BODIES OF WATER OVER THE
EASTERN CWA. INDEED... THE HRRR MODEL DEPICTS DENSE FOG FROM RDU
NORTH AND EAST AS WELL AS IN THE FAR SRN CWA IN THE PREDAWN HOURS.
OTHERWISE... THE DEPARTURE OF THE WEAK UPPER LEVEL WAVE IS NOW
PUSHING YESTERDAY`S COPIOUS MID/HIGH CLOUDINESS OFF THE NC COAST.
ANY DAYBREAK FOG/STRATUS IN THE EASTERN CWA SHOULD LIFT AND MIX OUT
BY MID MORNING... AND FORECAST SOUNDINGS UNIFORMLY SUPPORT
DEVELOPMENT OF SCATTERED FLAT DAYTIME CUMULUS BY THIS AFTERNOON.
WE`LL ALSO SEE THICKENING MID/HIGH CLOUDS BY LATE IN THE DAY AS THE
CLOUD SHIELD FROM THE OH VALLEY BACK OVER THE MID MISS VALLEY SLIDES
EASTWARD. THE SURFACE FRONT IS EXPECTED TO MAKE A SLOW SOUTHWARD
DRIFT THROUGH CENTRAL NC TODAY. A PRECEDING WEAK TROUGH WILL SWING
SURFACE WINDS AROUND TO NORTHERLY AND NORTHEASTERLY THIS MORNING...
BEFORE THE FRONTAL ZONE ITSELF DROPS SOUTHWARD LATER THIS
AFTERNOON... REACHING THE SC BORDER AREA BY EARLY-MID EVENING. THE
DELAY IN THE ARRIVAL OF COOLER LOW LEVEL THICKNESSES (ESPECIALLY IN
SRN NC WHERE THICKNESSES WILL PEAK NEAR 1410 METERS) AND LIMITED
CLOUD COVER THROUGH THE FIRST HALF OF THE DAY WILL ALLOW TEMPS TO
TOP OUT NEAR 80 TO 85... A COUPLE OF DEGREES ABOVE NORMAL. REGARDING
PRECIP CHANCES... DAYTIME HEATING WITH HIGHER SURFACE DEW POINTS AND
WEAK MASS CONVERGENCE ALONG THE PREFRONTAL TROUGH MAY INSTIGATE A
FEW SHALLOW LATE-AFTERNOON SHOWERS IN THE SOUTHEAST CWA... A
SCENARIO SUPPORTED BY THE CONVECTION-ALLOWING WRF-NMM. IN GENERAL
HOWEVER... THE MID LEVELS ARE LIKELY TO REMAIN TOO DRY AND STABLE
FOR ANY CONVECTIVE PRECIP TODAY... AND DYNAMIC FORCING FOR ASCENT IS
ABSENT AS WELL. BUT THE VORTICITY MAXIMUM CURRENTLY NOTED IN WATER
VAPOR IMAGERY OVER TN IS EXPECTED TO EASE EASTWARD THROUGH TODAY...
SHEARING ACROSS THE NC MTNS INTO THE SRN FOOTHILLS AND SRN PIEDMONT
STARTING THIS EVENING. ACCOMPANYING THIS WILL BE AN INCREASE IN
MOIST UPGLIDE AROUND 300K OVER WRN NC... AS THE 850 MB ANTICYCLONE
JUST TO OUR WEST THIS MORNING SHIFTS ESE RESULTING IN RETURN FLOW
INTO THE WRN CAROLINAS. SO ALONG WITH THE THICKER MID/HIGH CLOUDS
SPREADING IN FROM THE WEST THIS EVENING AND TONIGHT... LOWER LEVEL
MOISTURE WILL INCREASE AS WELL ESPECIALLY IN AREAS WEST OF HIGHWAY
1. WILL BRING IN A CHANCE OF SHOWERS AND STORMS INTO THE WRN AND SW
CWA OVERNIGHT. LOWS 57-64 WITH CLOUDS AND THE STALLED FRONT KEEPING
TEMPS UP IN THE SOUTHERN CWA.
FOR SUNDAY/SUNDAY NIGHT: A DEEP POSITIVELY-TILTED MID LEVEL TROUGH
WHICH NOW STRETCHES FROM SRN NM ACROSS THE TX PANHANDLE INTO ERN KS
WILL SHIFT EASTWARD ACROSS TX SUNDAY/SUNDAY NIGHT... WHILE WEAK
VORTICITY SHEARS EASTWARD IN FAST WEST-EAST FLOW AHEAD OF THE TROUGH
INTO NC. AT THE SURFACE... THE FRONTAL ZONE WILL REMAIN STALLED NEAR
THE NC/SC STATE LINE THROUGH SUNDAY... BUT AS THE HIGH PRESSURE AREA
CENTERED TO OUR NORTH OVER SWRN PA PUSHES EASTWARD ACROSS THE MID
ATLANTIC REGION... THE LOW LEVEL FLOW WILL STEADILY VEER FROM
NORTHEASTERLY TO EASTERLY THEN FINALLY TO SOUTHEASTERLY... WITH THE
FRONTAL ZONE KICKING BACK NORTHWARD THROUGH THE SRN PIEDMONT/WRN
SANDHILLS. IN ADDITION TO THE IMPROVING MID LEVEL LIFT OVER NC...
UPPER DIVERGENCE WILL STEADILY INCREASE AS FLOW ALOFT SPEEDS UP TO
OUR NORTH AND NW. AND THE DEEPENING LOW LEVEL RETURN FLOW WILL
GENERATE IMPROVING MOIST UPGLIDE PARTICULARLY OVER WRN AND NRN NC...
ALONG THE NORTHEAST-DRIFTING AND WEAKENING SURFACE FRONTAL ZONE.
MOISTURE WILL CONTINUE TO DEEPEN WITH PRECIP WATER VALUES INCREASING
TO 150-200% OF NORMAL SUNDAY THROUGH SUNDAY NIGHT. EXPECT THE CHANCE
FOR SHOWERS AND A FEW STORMS TO INCREASE AND SPREAD FROM THE FAR WRN
CWA EARLY ACROSS THE REST OF THE WRN CWA THROUGH SUNDAY... THEN WE
SHOULD SEE SCATTERED SHOWERS AND STORMS AREAWIDE (YET STILL FOCUSED
ON THE WEST/NORTH WHERE MOISTURE TRANSPORT WILL BE HIGHEST) SUNDAY
EVENING AND NIGHT AS THE MOIST UPGLIDE AND UPPER LEVEL FORCING
COMPENSATES FOR THE LOSS OF DAYTIME HEATING AND INSTABILITY.
THICKNESSES STAY NEAR SEASONAL NORMALS BUT WITH CLOUDS OVERSPREADING
THE AREA... EXPECT HIGHS TO BE A BIT UNDER NORMAL... IN THE UPPER
70S TO LOWER 80S. LOWS 61-65. -GIH
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 240 AM SATURDAY...
MONDAY...
AN UPPER LOW CURRENTLY OVER SOUTHERN NEW MEXICO WILL OPEN UP AND
DRIFT SLOWLY ACROSS THE SOUTHERN US THIS WEEKEND...AND EVENTUALLY
LIFT NORTHEAST TOWARD THE APPALACHIANS LATE MONDAY WHILE A NORTHERN
STREAM SHORTWAVE AMPLIFIES OUT OF CANADA INTO THE MID WEST.
WARM...MOIST ADVECTION WILL RAMP UP MONDAY AS A DEEP SOUTHWESTERLY
FLOW DEVELOPS AHEAD OF THE SOUTHERN STREAM WAVE...TAPPING THE GULF
OF MEXICO WHERE PW VALUES ARE WELL OVER 2 INCHES. HOWEVER...THE
STRENGTHENING LOW LEVEL JET AND BEST UPPER DIVERGENCE ASSOCIATED
WITH AN INTENSIFYING UPPER JET OVER THE GREAT LAKES WILL STILL BE
WEST OF THE MOUNTAINS DURING THE DAY...AND ONLY ISOLATED TO
SCATTERED WARM ADVECTION SHOWERS/STORMS ARE EXPECTED OVER CENTRAL
NC. DEEP LAYER SHEAR WILL BE INCREASING DURING THE DAY AS THE
HEIGHTS ALOFT BEGIN TO FALL OVER THE OHIO VALLEY AHEAD OF THE
NORTHERN STREAM WAVE. HOWEVER... INSTABILITY MAY BE HAMPERED BY
WIDESPREAD CLOUD COVER AND RELATIVELY WARM...MOIST MID LEVELS. WHILE
A FEW STRONG STORMS WILL BE POSSIBLE... THE MAIN SEVERE THREAT
SHOULD INSTEAD COME LATER MONDAY NIGHT INTO TUESDAY AS BETTER
SYNOPTIC FORCING ARRIVES. HIGHS MONDAY ARE FORECAST TO RANGE FROM
THE MID 70S NORTHWEST TO LOWER 80S SOUTHEAST.
MONDAY NIGHT THROUGH TUESDAY NIGHT...
THE AFOREMENTIONED SOUTHERN STREAM WAVE IS FORECAST TO WEAKEN AND
LIFT NORTHEAST FROM THE GULF COAST AND ALONG THE APPALACHIANS MONDAY
NIGHT AND TUESDAY. STRENGTHENING UPPER LEVEL DIVERGENCE...ALONG
WITH A 35-45 KT LOW LEVEL JET AND STRONG LOW LEVEL VEERING WILL
BRING A A PERIOD OF WIDESPREAD SHOWERS/STORMS TO THE AREA DURING
THIS PERIOD. HOWEVER...MODELS HAVE DIVERGED A BIT IN THE LAST FEW
RUNS REGARDING THE TIMING OF BEST FORCING...WITH THE GFS NOW
SLIGHTLY FASTER THAN THE ECMWF/NAM. PRECIP WILL CONTINUE TO BE
FOCUSED ALONG THE MOUNTAINS AND FOOTHILLS MONDAY EVENING AND
INITIALLY THERE MAY BE A STRONG GRADIENT BETWEEN WIDESPREAD SHOWERS
OVER THE WESTERN PIEDMONT AND LITTLE TO NO ACTIVITY TO THE EAST.
HOWEVER...AS THE REMNANTS OF THE SOUTHERN STREAM SHORTWAVE
ARRIVES...PRECIP WILL SPREAD EAST ACROSS THE CWA...BETWEEN 06Z AND
18Z TUESDAY BASED ON CURRENT MODEL PROJECTIONS. WHILE MODELS HAVE
GRADUALLY BACKED OFF ON SHOWING A SURFACE LOW EAST OF THE
MOUNTAINS...THERE WILL STILL BE A WINDOW WHERE BACKED SURFACE
WINDS...STRONG LOW LEVEL SHEAR AND LOW LCLS MAY SUPPORT A TORNADO
THREAT. HOWEVER...INSTABILITY AND POTENTIAL UPDRAFT STRENGTH ARE
QUESTIONABLE DUE TO THE LESS FAVORABLE OVERNIGHT
TIMING...PARTICULARLY IN THE GFS SOLUTION. AS SUCH... QUITE A BIT OF
UNCERTAINTY REMAINS REGARDING THE SEVERE/TORNADO THREAT. HEAVY RAIN
LOOKS TO ALMOST CERTAINLY BE AN ISSUE...ESPECIALLY OVER THE WESTERN
PIEDMONT...WITH A PROLONGED FETCH OF GULF MOISTURE AND PERSISTENT
ISENTROPIC/UPSLOPE AIDED ACCENT MONDAY NIGHT. LOWS SHOULD BE MUGGY
IN THE MID TO UPPER 60S.
AS THE COLD FRONT APPROACHES FROM THE MID WEST ON TUESDAY...MODELS
ARE SHOWING A BIT MORE OF A NEGATIVE TILT TO THE MAIN TROUGH AXIS AS
IT SWINGS ACROSS THE OH/TN VALLEY REGIONS. THUS...SHOWERS AND
STORMS SHOULD BEGIN TO SHIFT EAST ACROSS THE CWA MORE RAPIDLY BY
TUESDAY AFTERNOON AND EVENING...MOVING EAST OF THE COASTAL PLAIN BY
TUESDAY NIGHT. THE COLD FRONT MAY LAG A BIT...BUT SHOULD ALSO CLEAR
THE AREA BY WEDNESDAY MORNING...WITH HIGH PRESSURE BUILDING ACROSS
THE CENTRAL APPALACHIANS. QUIET WEATHER IS THEN EXPECTED THROUGH
THE END OF THE WEEK...WITH THE POTENTIAL FOR ANOTHER NORTHERN STREAM
WAVE APPROACHING FROM THE MIDWEST NEXT WEEKEND.
REGARDING POPS AND TEMPS....
WILL NOT MAKE ANY SIGNIFICANT CHANGES TO THE LIKELY/CATEGORICAL POPS
MONDAY NIGHT AND TUESDAY...AND WILL HAVE POPS COMING TO AN END IN
THE EAST PRIOR TO 12Z WEDNESDAY. HIGHS TUESDAY WILL BE TRICKY DUE
TO THE PRECIP COVERAGE BUT SHOULD BE MOSTLY IN THE 70S...EXCEPT FOR
THE FAR SOUTHEAST WHERE 80 MAY BE POSSIBLE.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 240 AM SATURDAY...
DRIER AND MORE STABLE AIR IS FORECAST TO FILTER ACROSS THE AREA
WEDNESDAY AND THURSDAY AS THE EARLY WEEK STORM SYSTEM DEPARTS THE
REGION AND HIGH PRESSURE BUILDS ACROSS THE LOWER MIDWEST. THIS WILL
LEAD TO A RELATIVE MIN IN HIGH TEMPS...AS MUCH AS 4-8 DEGREES BELOW
NORMAL BASED ON POST-FRONTAL THICKNESSES SOME 15-20M BELOW NORMAL.
MODELS THEN SHOW ANOTHER NORTHERN STREAM WAVE DIVING OUT OF CANADA
AND STRENGTHENING THE LONG WAVE TROUGH OVER THE EASTERN HALF OF THE
US....WITH ANOTHER COLD FRONT POSSIBLY APPROACHING THE CAROLINAS BY
NEXT WEEKEND.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 215 AM SATURDAY...
THE MAIN CONCERN EARLY THIS MORNING IS AREAS OF FOG FORMING NEAR
KRWI. EXPECT IFR/LIFR CONDITIONS TO HOLD HERE FOR THE REMAINDER OF
THE NIGHT... GIVEN THE LIGHT WINDS AND CLEAR SKIES ALOFT ENSURING
GOOD RADIATIONAL COOLING AND LITTLE TO NO LOW LEVEL MIXING
VERTICALLY OR HORIZONTALLY. BANKS OF FOG... MAINLY NEAR BODIES OF
WATER... ARE POSSIBLE AT KRDU AND KFAY AS WELL PRIOR TO 12Z THIS
MORNING. A BRIEF PERIOD OF MVFR VSBY IS POSSIBLE AT THESE LOCATIONS.
LOWER NEAR-GROUND HUMIDITY AT KINT/KGSO WILL LIMIT ANY FOG
DEVELOPMENT AT THESE SITES.
ANY ADVERSE AVIATION CONDITIONS AT KRDU/KFAY WILL LIFT/MIX OUT BY
14Z. SIMILARLY... THE IFR/LIFR VSBY/CIG AT KRWI WILL SLOWLY IMPROVE
TO VFR THROUGH 15Z. AFTER THIS TIME... DAYTIME CUMULUS CLOUDS THIS
AFTERNOON AT ALL CENTRAL NC FORECAST SITES WILL BE BASED ABOVE 4
THOUSAND FT AGL. A WEAK FRONT WILL SINK SOUTHWARD THROUGH NC DURING
TODAY. WINDS OVER CENTRAL NC WILL BE LIGHT (UNDER 8 KTS OVERALL)
FROM THE NORTH THEN NORTHEAST THIS MORNING... EVENTUALLY SHIFTING TO
BE FROM THE EAST THEN ESE LATER TODAY AS HIGH PRESSURE TO OUR NORTH
BUILDS IN BRIEFLY BEHIND THE FRONT. ONLY ISOLATED SHOWERS ARE
EXPECTED THROUGH NIGHTFALL... HOWEVER CLOUDS BASED ABOVE 4 THOUSAND
FEET WILL STEADILY INCREASE IN NUMBER AND THICKEN BY EARLY
EVENING... RESULTING IN BROKEN TO OVERCAST VFR SKIES AT
KINT/KGSO/KRDU TOWARD 06Z WHILE SKIES REMAIN FAIR AT KRWI/KFAY. NO
FOG IS EXPECTED PRIOR TO 06Z TONIGHT.
LOOKING BEYOND 06Z TONIGHT... CIGS WILL LOWER TOWARD SUNDAY MORNING
BUT WILL MOSTLY REMAIN VFR... AS WILL VSBYS WITH LITTLE TO NO FOG
EXPECTED TO DEVELOP. A MID-UPPER TROUGH OVER NM/TX THIS MORNING WILL
MOVE SLOWLY EASTWARD SUNDAY THROUGH MONDAY AS A STRENGTHENING FRONT
APPROACHES FROM THE WEST... AND AVIATION CONDITIONS WILL SLOWLY
DETERIORATE IN THIS TIME FRAME... STARTING FIRST AT KINT/KGSO SUNDAY
NIGHT WITH MVFR CIGS/VSBYS IN SHOWERS/STORMS. MVFR TO IFR CONDITIONS
ARE LIKELY ALL ACROSS CENTRAL NC LATE MONDAY WELL INTO TUESDAY WITH
STRONG VEERING WINDS THROUGH THE LOWEST 10 THOUSAND FT. IMPROVING
CONDITIONS ARE EXPECTED WEDNESDAY WITH A COOLER INCOMING AIR MASS
BEHIND THE FRONT. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...SMITH
LONG TERM...SMITH
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
215 AM EDT SAT SEP 15 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL DROP SOUTHWARD THROUGH NORTH CAROLINA
TODAY... THEN STALL NEAR THE SOUTH CAROLINA BORDER THROUGH SUNDAY...
BEFORE DRIFTING BACK NORTHWARD AS A WARM FRONT SUNDAY NIGHT. A
STRONG STORM SYSTEM WILL APPROACH THE AREA FROM THE SOUTHWEST MONDAY
THROUGH TUESDAY.
&&
.NEAR TERM /TODAY THROUGH SUNDAY NIGHT/...
AS OF 215 AM SATURDAY...
FOR TODAY/TONIGHT: EXPECT A FAIRLY QUIET AND SUMMER-LIKE DAY
OVERALL... BUT WITH AN INCREASE IN CLOUDS LATE. THE LATEST SURFACE
ANALYSIS SHOWS THE VERY WEAK SURFACE RIDGE CONTINUING TO LOSE ITS
GRIP ON THE AREA AHEAD OF AN INCOMING COOL FRONT... STRETCHING FROM
NEW ENGLAND ACROSS SE WV TO THE MO/AR BORDER. AS ANTICIPATED...
SURFACE DEW POINTS HAVE REBOUNDED FROM 24 HOURS AGO TO AROUND 60
WEST AND MID-UPPER 60S EAST. WITH LIGHT WINDS AND ONLY PATCHES OF
HIGH CLOUDS EARLY THIS MORNING... FOG FORMATION IS FAVORED
ESPECIALLY IN LOW-LYING AREAS AND NEAR BODIES OF WATER OVER THE
EASTERN CWA. INDEED... THE HRRR MODEL DEPICTS DENSE FOG FROM RDU
NORTH AND EAST AS WELL AS IN THE FAR SRN CWA IN THE PREDAWN HOURS.
OTHERWISE... THE DEPARTURE OF THE WEAK UPPER LEVEL WAVE IS NOW
PUSHING YESTERDAY`S COPIOUS MID/HIGH CLOUDINESS OFF THE NC COAST.
ANY DAYBREAK FOG/STRATUS IN THE EASTERN CWA SHOULD LIFT AND MIX OUT
BY MID MORNING... AND FORECAST SOUNDINGS UNIFORMLY SUPPORT
DEVELOPMENT OF SCATTERED FLAT DAYTIME CUMULUS BY THIS AFTERNOON.
WE`LL ALSO SEE THICKENING MID/HIGH CLOUDS BY LATE IN THE DAY AS THE
CLOUD SHIELD FROM THE OH VALLEY BACK OVER THE MID MISS VALLEY SLIDES
EASTWARD. THE SURFACE FRONT IS EXPECTED TO MAKE A SLOW SOUTHWARD
DRIFT THROUGH CENTRAL NC TODAY. A PRECEDING WEAK TROUGH WILL SWING
SURFACE WINDS AROUND TO NORTHERLY AND NORTHEASTERLY THIS MORNING...
BEFORE THE FRONTAL ZONE ITSELF DROPS SOUTHWARD LATER THIS
AFTERNOON... REACHING THE SC BORDER AREA BY EARLY-MID EVENING. THE
DELAY IN THE ARRIVAL OF COOLER LOW LEVEL THICKNESSES (ESPECIALLY IN
SRN NC WHERE THICKNESSES WILL PEAK NEAR 1410 METERS) AND LIMITED
CLOUD COVER THROUGH THE FIRST HALF OF THE DAY WILL ALLOW TEMPS TO
TOP OUT NEAR 80 TO 85... A COUPLE OF DEGREES ABOVE NORMAL. REGARDING
PRECIP CHANCES... DAYTIME HEATING WITH HIGHER SURFACE DEW POINTS AND
WEAK MASS CONVERGENCE ALONG THE PREFRONTAL TROUGH MAY INSTIGATE A
FEW SHALLOW LATE-AFTERNOON SHOWERS IN THE SOUTHEAST CWA... A
SCENARIO SUPPORTED BY THE CONVECTION-ALLOWING WRF-NMM. IN GENERAL
HOWEVER... THE MID LEVELS ARE LIKELY TO REMAIN TOO DRY AND STABLE
FOR ANY CONVECTIVE PRECIP TODAY... AND DYNAMIC FORCING FOR ASCENT IS
ABSENT AS WELL. BUT THE VORTICITY MAXIMUM CURRENTLY NOTED IN WATER
VAPOR IMAGERY OVER TN IS EXPECTED TO EASE EASTWARD THROUGH TODAY...
SHEARING ACROSS THE NC MTNS INTO THE SRN FOOTHILLS AND SRN PIEDMONT
STARTING THIS EVENING. ACCOMPANYING THIS WILL BE AN INCREASE IN
MOIST UPGLIDE AROUND 300K OVER WRN NC... AS THE 850 MB ANTICYCLONE
JUST TO OUR WEST THIS MORNING SHIFTS ESE RESULTING IN RETURN FLOW
INTO THE WRN CAROLINAS. SO ALONG WITH THE THICKER MID/HIGH CLOUDS
SPREADING IN FROM THE WEST THIS EVENING AND TONIGHT... LOWER LEVEL
MOISTURE WILL INCREASE AS WELL ESPECIALLY IN AREAS WEST OF HIGHWAY
1. WILL BRING IN A CHANCE OF SHOWERS AND STORMS INTO THE WRN AND SW
CWA OVERNIGHT. LOWS 57-64 WITH CLOUDS AND THE STALLED FRONT KEEPING
TEMPS UP IN THE SOUTHERN CWA.
FOR SUNDAY/SUNDAY NIGHT: A DEEP POSITIVELY-TILTED MID LEVEL TROUGH
WHICH NOW STRETCHES FROM SRN NM ACROSS THE TX PANHANDLE INTO ERN KS
WILL SHIFT EASTWARD ACROSS TX SUNDAY/SUNDAY NIGHT... WHILE WEAK
VORTICITY SHEARS EASTWARD IN FAST WEST-EAST FLOW AHEAD OF THE TROUGH
INTO NC. AT THE SURFACE... THE FRONTAL ZONE WILL REMAIN STALLED NEAR
THE NC/SC STATE LINE THROUGH SUNDAY... BUT AS THE HIGH PRESSURE AREA
CENTERED TO OUR NORTH OVER SWRN PA PUSHES EASTWARD ACROSS THE MID
ATLANTIC REGION... THE LOW LEVEL FLOW WILL STEADILY VEER FROM
NORTHEASTERLY TO EASTERLY THEN FINALLY TO SOUTHEASTERLY... WITH THE
FRONTAL ZONE KICKING BACK NORTHWARD THROUGH THE SRN PIEDMONT/WRN
SANDHILLS. IN ADDITION TO THE IMPROVING MID LEVEL LIFT OVER NC...
UPPER DIVERGENCE WILL STEADILY INCREASE AS FLOW ALOFT SPEEDS UP TO
OUR NORTH AND NW. AND THE DEEPENING LOW LEVEL RETURN FLOW WILL
GENERATE IMPROVING MOIST UPGLIDE PARTICULARLY OVER WRN AND NRN NC...
ALONG THE NORTHEAST-DRIFTING AND WEAKENING SURFACE FRONTAL ZONE.
MOISTURE WILL CONTINUE TO DEEPEN WITH PRECIP WATER VALUES INCREASING
TO 150-200% OF NORMAL SUNDAY THROUGH SUNDAY NIGHT. EXPECT THE CHANCE
FOR SHOWERS AND A FEW STORMS TO INCREASE AND SPREAD FROM THE FAR WRN
CWA EARLY ACROSS THE REST OF THE WRN CWA THROUGH SUNDAY... THEN WE
SHOULD SEE SCATTERED SHOWERS AND STORMS AREAWIDE (YET STILL FOCUSED
ON THE WEST/NORTH WHERE MOISTURE TRANSPORT WILL BE HIGHEST) SUNDAY
EVENING AND NIGHT AS THE MOIST UPGLIDE AND UPPER LEVEL FORCING
COMPENSATES FOR THE LOSS OF DAYTIME HEATING AND INSTABILITY.
THICKNESSES STAY NEAR SEASONAL NORMALS BUT WITH CLOUDS OVERSPREADING
THE AREA... EXPECT HIGHS TO BE A BIT UNDER NORMAL... IN THE UPPER
70S TO LOWER 80S. LOWS 61-65. -GIH
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 230 PM FRIDAY...
MONDAY THROUGH TUESDAY NIGHT:
A FAIR AMOUNT OF UNCERTAINTY PERSISTS WITH REGARD TO THE SPECIFICS
OF THE FORECAST IN THIS PERIOD...THOUGH OVERALL CHANCES FOR RAIN
(PERHAPS HEAVY) REMAIN HIGH...ESPECIALLY OVER WESTERN PORTIONS OF
THE STATE. UNCERTAINTY IN THE EVOLUTION OF THE UPPER LEVEL PATTERN
(AND ATTENDANT SURFACE PATTERN) OVER THE EASTERN CONUS IS LARGE DUE
TO SEVERAL FACTORS. A STALLED SOUTHERN STREAM WAVE OVER THE DESERT
SOUTHWEST IS EXPECTED TO BECOME PROGRESSIVE OVER THE WEEKEND...
TRACKING INTO THE LOWER MS RIVER VALLEY BY SUN NIGHT/MONDAY. AT THE
SAME TIME...A NORTHERN STREAM TROUGH IS PROGGED TO DIG SOUTHEAST
FROM CANADA INTO THE UPPER MIDWEST SUNDAY NIGHT...AMPLIFYING AS IT
DIGS SOUTHWARD/SSE INTO THE OH/TN VALLEYS MONDAY NIGHT AND TUESDAY.
IN ADDITION TO TYPICAL UNCERTAINTY IN THE EVOLUTION OF THE NORTHERN
STREAM PATTERN OVER CANADA (DATA SPARSE AREA) SEVERAL DAYS FROM
NOW...MATTERS ARE FURTHER COMPLICATED BY THE POTENTIAL INTERACTION
BETWEEN THE NORTHERN AND SOUTHERN STREAM WAVES EARLY NEXT WEEK. THE
EVOLUTION OF THE UPPER LEVEL PATTERN (IN ADDITION TO DEEP CONVECTION
UPSTREAM OF THE AREA OVER THE DEEP SOUTH/SOUTHEAST ON MONDAY) WILL
IN LARGE PART DETERMINE THE LOW-LEVEL HEIGHT/MSLP PATTERN OVER THE
CAROLINAS MON-TUE.
ALTHOUGH CONFIDENCE IN WIDESPREAD CLOUD COVER AND PRECIPITATION IS
HIGH...PARTICULARLY MONDAY NIGHT/TUESDAY...IT IS STILL DIFFICULT TO
DETERMINE THE NATURE OF THE SEVERE THREAT. HAVING SAID THAT...THE
12Z GFS/ECMWF ARE INDICATING STRONG/VEERING LOW-LEVEL FLOW (40-50 KT
AT H85) MONDAY NIGHT/TUESDAY...WITH RELATIVELY LARGE CLOCKWISE-
CURVED HODOGRAPHS /STRONG 0-1 KM SRH/ AND 35-45 KNOTS OF DEEP LAYER
SHEAR IN THE PRESENCE OF A VERY MOIST BOUNDARY LAYER (SFC DEWPOINTS
IN THE UPPER 60S) AND DEEP-LAYER ASCENT. WITH THE ABOVE IN MIND...
THE LATEST GUIDANCE SUGGESTS AN ISOLD TORNADO POTENTIAL MONDAY NIGHT
INTO TUESDAY...THOUGH THE GFS/ECMWF DIFFER ON THE TIMING...THE GFS
ARGUING EARLIER (ON MONDAY NIGHT) AND THE ECMWF LATER (TUE MORNING
INTO TUE AFTERNOON). HEAVY RAINFALL AND FLOODING WOULD ALSO BE
POSSIBLE MONDAY AFTERNOON THROUGH TUESDAY...ESPECIALLY IN THE W/NW
PIEDMONT...THOUGH THE BEST CHANCE SHOULD BE FURTHER WEST IN THE
FOOTHILLS/MOUNTAINS.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 315 PM FRIDAY...
WEDNESDAY THROUGH FRIDAY:
EXPECT HEIGHT RISES ALOFT AND HIGH PRESSURE BUILDING INTO THE AREA
WED/THU...WITH CLEARING SKIES AND TEMPERATURES 5-10F COOLER THAN
NORMAL. A DEEPENING UPPER LEVEL TROUGH IS POSSIBLE OVER THE GREAT
LAKES FRIDAY...WHICH WOULD PUSH ANOTHER FRONT TOWARD THE SOUTHERN
APPALACHIANS OVER THE WEEKEND. AT THIS TIME EXPECT PARTLY CLOUDY
SKIES AND NEAR NORMAL TEMPS ON FRIDAY. -VINCENT
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 215 AM SATURDAY...
THE MAIN CONCERN EARLY THIS MORNING IS AREAS OF FOG FORMING NEAR
KRWI. EXPECT IFR/LIFR CONDITIONS TO HOLD HERE FOR THE REMAINDER OF
THE NIGHT... GIVEN THE LIGHT WINDS AND CLEAR SKIES ALOFT ENSURING
GOOD RADIATIONAL COOLING AND LITTLE TO NO LOW LEVEL MIXING
VERTICALLY OR HORIZONTALLY. BANKS OF FOG... MAINLY NEAR BODIES OF
WATER... ARE POSSIBLE AT KRDU AND KFAY AS WELL PRIOR TO 12Z THIS
MORNING. A BRIEF PERIOD OF MVFR VSBY IS POSSIBLE AT THESE LOCATIONS.
LOWER NEAR-GROUND HUMIDITY AT KINT/KGSO WILL LIMIT ANY FOG
DEVELOPMENT AT THESE SITES.
ANY ADVERSE AVIATION CONDITIONS AT KRDU/KFAY WILL LIFT/MIX OUT BY
14Z. SIMILARLY... THE IFR/LIFR VSBY/CIG AT KRWI WILL SLOWLY IMPROVE
TO VFR THROUGH 15Z. AFTER THIS TIME... DAYTIME CUMULUS CLOUDS THIS
AFTERNOON AT ALL CENTRAL NC FORECAST SITES WILL BE BASED ABOVE 4
THOUSAND FT AGL. A WEAK FRONT WILL SINK SOUTHWARD THROUGH NC DURING
TODAY. WINDS OVER CENTRAL NC WILL BE LIGHT (UNDER 8 KTS OVERALL)
FROM THE NORTH THEN NORTHEAST THIS MORNING... EVENTUALLY SHIFTING TO
BE FROM THE EAST THEN ESE LATER TODAY AS HIGH PRESSURE TO OUR NORTH
BUILDS IN BRIEFLY BEHIND THE FRONT. ONLY ISOLATED SHOWERS ARE
EXPECTED THROUGH NIGHTFALL... HOWEVER CLOUDS BASED ABOVE 4 THOUSAND
FEET WILL STEADILY INCREASE IN NUMBER AND THICKEN BY EARLY
EVENING... RESULTING IN BROKEN TO OVERCAST VFR SKIES AT
KINT/KGSO/KRDU TOWARD 06Z WHILE SKIES REMAIN FAIR AT KRWI/KFAY. NO
FOG IS EXPECTED PRIOR TO 06Z TONIGHT.
LOOKING BEYOND 06Z TONIGHT... CIGS WILL LOWER TOWARD SUNDAY MORNING
BUT WILL MOSTLY REMAIN VFR... AS WILL VSBYS WITH LITTLE TO NO FOG
EXPECTED TO DEVELOP. A MID-UPPER TROUGH OVER NM/TX THIS MORNING WILL
MOVE SLOWLY EASTWARD SUNDAY THROUGH MONDAY AS A STRENGTHENING FRONT
APPROACHES FROM THE WEST... AND AVIATION CONDITIONS WILL SLOWLY
DETERIORATE IN THIS TIME FRAME... STARTING FIRST AT KINT/KGSO SUNDAY
NIGHT WITH MVFR CIGS/VSBYS IN SHOWERS/STORMS. MVFR TO IFR CONDITIONS
ARE LIKELY ALL ACROSS CENTRAL NC LATE MONDAY WELL INTO TUESDAY WITH
STRONG VEERING WINDS THROUGH THE LOWEST 10 THOUSAND FT. IMPROVING
CONDITIONS ARE EXPECTED WEDNESDAY WITH A COOLER INCOMING AIR MASS
BEHIND THE FRONT. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...VINCENT
LONG TERM...VINCENT
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1117 PM CDT FRI SEP 14 2012
.DISCUSSION...
UPDATED FOR 06Z AVIATION DISCUSSION
&&
.PREV DISCUSSION... /ISSUED 828 PM CDT FRI SEP 14 2012/
UPDATE...
LATEST RADAR IMAGES SHOW A LARGE AREA OF RAIN OVER CENTRAL
ARKANSAS. MOST MODELS INDICATE THE RAIN SHOULD STAY WEST OF THE
CWA HOWEVER LOOKING AT KNQA RADAR THE FRONT EDGE OF THE RAIN CONTINUES
TO PUSH EAST. HRRR MODEL IS THE ONLY ONE THAT PUSHES THE RAIN INTO
THE CWA INCLUDING MEMPHIS BY 10-12Z. WILL UPDATE TO RAISE POPS
TO 50 ACROSS EASTERN ARKANSAS. WILL ALSO BUMP UP LOWS ACROSS THE
WEST DUE TO CLOUD COVER. UPDATE WILL BE OUT SHORTLY.
KRM
DISCUSSION... /ISSUED 305 PM CDT FRI SEP 14 2012/
SKIES ARE PARTLY TO MOSTLY CLOUDY ACROSS MUCH OF THE FORECAST
AREA THIS AFTERNOON WITH TEMPERATURES IN THE UPPER 70S TO UPPER
80S. THE COLD FRONT EXTENDS FROM NORTHWEST PENNSYLVANIA THROUGH
WEST TENNESSEE AND INTO SOUTHEAST TEXAS. SOME SCATTERED SHOWERS
AND ISOLATED THUNDERSTORMS CONTINUE TO MOVE ACROSS PORTIONS OF THE
FORECAST AREA NEAR THE FRONT. MOST OF THE ACTIVITY IN WEST
TENNESSEE IS MOVING SOUTHEAST WHILE THE ACTIVITY IN EAST ARKANSAS
IS MOVING NORTH.
AS THE FRONT CONTINUES TO PUSH EAST TONIGHT MORE SHOWERS AND A FEW
THUNDERSTORMS WILL BE POSSIBLE TONIGHT. THE FRONT SHOULD MOVE OUT
OF THE FORECAST AREA BY SATURDAY MORNING. HOWEVER AN UPPER LEVEL
DISTURBANCES WILL MOVE THROUGH THE REGION ON SATURDAY BRINGING
SCATTERED SHOWERS AND POSSIBLY A THUNDERSTORM OR TWO WITH IT. AN
UPPER LEVEL TROUGH WILL MOVE THROUGH THE REGION SUNDAY AND MONDAY
BRINGING A BETTER CHANCE OF RAIN. TEMPERATURES THIS WEEKEND WILL
REMAIN AT OR A FEW DEGREES BELOW NORMAL FOR MID SEPTEMBER.
BY MONDAY NIGHT...A COLD FRONT WILL MOVE THROUGH THE FORECAST AREA
BRINGING MORE SHOWERS AND A FEW THUNDERSTORMS. THIS FRONT SHOULD
BE OUT OF THE REGION BY TUESDAY MORNING WITH RAIN ENDING FROM WEST
TO EAST. MUCH COOLER AND DRIER AIR WILL MOVE INTO THE AREA BEHIND
THE FRONT WITH AFTERNOON TEMPERATURES ON TUESDAY IN THE 70S. SKIES
SHOULD CLEAR OUT AND WINDS WILL BECOME LIGHT BY WEDNESDAY MORNING
SETTING THE STAGE FOR A RATHER COOL MORNING. MANY LOCATIONS IN THE
NORTHERN HALF OF THE FORECAST AREA WILL SEE READINGS IN THE 40S ON
WEDNESDAY MORNING.
HIGH PRESSURE WILL REMAIN IN CONTROL OF THE WEATHER FROM WEDNESDAY
THROUGH EARLY FRIDAY MORNING WITH NO RAIN AND TEMPERATURES
REMAINING BELOW NORMAL. ANOTHER COLD FRONT WILL BE APPROACHING THE
REGION ON FRIDAY BRINGING A SMALL CHANCE OF SHOWERS AHEAD OF IT.
ARS
&&
.AVIATION...
06Z TAF CYCLE
MAINLY VFR CONDS WILL PREVAIL THROUGH THE PERIOD. SOME IFR/MVFR
CIGS MAY DEVELOP AT KJBR AND KMEM OVER THE NEXT FEW HOURS AND
HAVE ADDED SOME TEMPOS FOR THIS POSSIBILITY. SOME LIGHT FOG IS
ALSO POSSIBLE AT KMKL. CONDS SHOULD BE VFR EVERYWHERE AFT 15/13Z.
A FEW SHRAS WILL BE POSSIBLE NEAR KJBR AND KMEM THROUGH SATURDAY
THOUGH MOST PRECIP WILL REMAIN TO THE WEST. WINDS WILL GENERALLY
BE LIGHT NE.
SJM
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 68 83 66 84 / 30 30 30 50
MKL 61 81 60 82 / 20 30 30 50
JBR 64 78 62 78 / 50 40 40 50
TUP 64 86 65 86 / 20 20 20 40
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
357 AM CDT SAT SEP 15 2012
.SHORT TERM (TODAY THROUGH SUNDAY)...MSAS ANALYSIS REVEALS FRONTAL
HAS BECOME STATIONARY EARLY THIS MORNING ACROSS THE NEARSHORE
MIDDLE TEXAS COASTAL WATERS. WEAK MID/UPPER LEVEL CYCLONIC SHEAR
AXIS ALSO OVER THE REGION...AND THE TWO FEATURES ARE INTERACTING
WITH DEEP MOISTURE AND GENERATING NUMEROUS SHOWERS AND THUNDERSTORMS
JUST OFFSHORE. GFS/NAM IN ADDITION TO HRRR AND NSSL 4 KM WRF
INDICATE THE BOUNDARY REMAINING JUST OFFSHORE THROUGH THE MORNING
HOURS...ALTHOUGH A SLIGHT WESTWARD DRIFT IN THE CONVECTION IS
LIKELY TO OCCUR. SOME OF THESE SHOWERS AND THUNDERSTORMS MAY
SNEAK ACROSS THE BARRIER ISLANDS INTO COASTAL LOCATIONS OF NUECES
AND KLEBERG COUNTIES THROUGH THE MORNING...BUT THE BULK OF THE
CONVECTION WILL REMAIN JUST OFFSHORE. FURTHER INLAND ACROSS SOUTH
TEXAS...A FEW WEAK SHOWERS MAY DEVELOP TOWARDS AND AFTER SUNRISE.
A SHARP GRADIENT IN POPS IS INDICATED THIS MORNING. LATER THIS
AFTERNOON...THE BOUNDARY DRIFTS BACK INLAND AND WASHES OUT. A
RETURN TO WEAK ONSHORE FLOW SHOULD ALLOW FOR ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS TO DEVELOP ACROSS THE INLAND COASTAL
BEND AND BRUSH COUNTRY MID TO LATE AFTERNOON.
ATTENTION THEN SHIFTS TO LATE TONIGHT INTO SUNDAY. POSITIVELY
TILTED TROUGH APPROACHES THE RIO GRANDE PLAINS AFTER MIDNIGHT
ALONG WITH A MODEST 50-60 KT UPPER LEVEL JET STREAK. MID/UPPER
LEVEL FORCING WILL GRADUALLY INCREASE OVERNIGHT AND PEAK ACROSS
THE RIO GRANDE PLAINS AND WESTERN BRUSH COUNTRY AROUND 12Z SUNDAY.
THE FORCING GRADUALLY MOVES EASTWARD DURING THE SUNDAY...INTO THE
COASTAL BEND/VICTORIA REGION MIDDAY. SHOWERS AND THUNDERSTORMS ARE
LIKELY ACROSS WESTERN CWA OVERNIGHT AND EARLY SUNDAY MORNING...AND
ACROSS THE EAST LATE SUNDAY MORNING THROUGH AFTERNOON. POPS ARE
HIGHEST ACROSS THE NORTH AND NORTHEAST CWA SUNDAY. HIGH TEMPS VERY
DEPENDENT ON CLOUD COVER AND RAINFALL TODAY AND SUNDAY...GENERALLY
IN THE MID AND UPPER 80S.
&&
.LONG TERM (SUNDAY NIGHT THROUGH SATURDAY)...MID LVL TROUGH WILL
ADVANCE INTO THE COASTAL WATERS SUN NIGHT WITH PCPN ENDING OVER THE
WATERS BY MONDAY MORNING. CLEARING SKIES AND SUBSIDENT FLOW WILL
ALLOW TEMPS TO RECOVER INTO THE 90S AREA WIDE. ANOTHER TROUGH AND
ASSOCIATED WEAK COOL FRONT WILL DIP INTO SOUTH TEXAS TUESDAY.
HOWEVER NOT EXPECTING PCPN DUE TO DRY ATMOSPHIC COLUMN (PWS NEAR
1.3"). ENOUGH MOISTURE WILL POOL ALONG THE BOUNDARY OVER THE GULF
WATERS BY WED AM TO GENERATE A FEW SHOWERS. A WEAK MID LVL RIDGE
WILL BUILD BACK OVER SOUTH TEXAS THROUGH THE REMAINDER OF THE WEEK
WITH A GRADUAL WARMING TREND AND NO SIGNIFICANT OPPORTUNITIES FOR
RAINFALL. A WEAK TO MODERATE ONSHORE FLOW WILL PERSIST THROUGH THE
END OF THE FORECAST PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 89 71 87 70 90 / 50 40 70 20 10
VICTORIA 88 68 86 67 90 / 50 50 80 30 10
LAREDO 88 70 88 71 98 / 40 60 50 10 10
ALICE 89 69 87 68 93 / 50 40 70 20 10
ROCKPORT 86 71 85 71 89 / 50 40 80 30 10
COTULLA 86 67 85 68 94 / 40 70 70 10 10
KINGSVILLE 88 70 87 69 91 / 50 40 70 20 10
NAVY CORPUS 86 73 86 73 87 / 50 40 70 20 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
JR/76...SHORT TERM
JM/75...LONG TERM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
305 AM CDT SAT SEP 15 2012
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
305 AM CDT SAT SEP 15 2012
MAIN FORECAST CONCERN REMAINS ON THE SUNDAY NIGHT THROUGH MONDAY
NIGHT TIME FRAME WITH TIMING OF THE PRECIPITATION AND TEMPERATURES
IN ITS WAKE.
07Z SURFACE ANALYSIS SHOWS HIGH PRESSURE FROM LAKE SUPERIOR THROUGH
EASTERN WISCONSIN AND ILLINOIS. SKIES WERE CLEAR AROUND THE FORECAST
AREA WITH JUST SOME PATCHY FOG IN SOME OF THE FOG PRONE AREAS OF
CENTRAL WISCONSIN.
15.00Z MODELS IN EXCELLENT AGREEMENT THROUGH THE PERIOD...WITH THE
MAIN CHANGE BEING A SLOWER ONSET OF PRECIPITATION ACROSS THE AREA
SUNDAY NIGHT. OTHERWISE PREVIOUS FORECAST ON TRACK.
IN THE NEAR TERM...HIGH PRESSURE WILL CONTINUE TO SLIDE EAST OF THE
AREA TODAY...WITH PRESSURE GRADIENT TIGHTENING. TEMPERATURES WILL BE
A FEW DEGREES WARMER THAN YESTERDAY WITH PERSISTENT SOUTHWEST FLOW.
WITH GOOD MIXING AND WINDS GUSTING TO NEAR 20 MPH WILL SEE NEAR
CRITICAL FIRE WEATHER CONDITIONS ACROSS SOUTHEAST MINNESOTA AND
NORTHEAST IOWA (SEE FIRE WEATHER DISCUSSION BELOW). THIS QUIET
WEATHER WILL CONTINUE RIGHT INTO SUNDAY...WITH THE WARM TEMPERATURES
CONTINUING UNDER PLENTY OF SUNSHINE.
ATTENTION THEN TURNS TO THE SUNDAY NIGHT THROUGH MONDAY NIGHT TIME
FRAME. SHORTWAVE TROUGH DIGS ACROSS THE NORTHERN PLAINS...PUSHING
SURFACE COLD FRONT ACROSS THE AREA ON MONDAY. RATHER STRONG
850MB-700MB FRONTOGENESIS ACCOMPANIES THE FRONT ACROSS THE AREA.
MODELS HAVE TRENDED SLOWER WITH THE SYSTEM AND THUS HAVE BACKED OFF
ON RAIN PROBABILITIES SUNDAY EVENING. BOTH THE GFS AND NAM SHOWING
500-1000 J/KG OF MOST UNSTABLE CAPE SUNDAY NIGHT AND MONDAY AND THUS
DID KEEP THE ISOLATED THUNDER MENTION IN THE GRIDS. SEVERE WEATHER
POTENTIAL LOOKS TO BE RATHER LIMITED AS SHEAR ONLY 25 TO 30
KNOTS...BUT CANNOT RULE OUT SOME SMALL HAIL OR GUSTY WINDS WITH SOME
OF THE STRONGER CELLS. HIGHEST RAIN PROBABILITIES LOOK TO BE LATE
SUNDAY NIGHT INTO MONDAY. STRONG COLD ADVECTION IN THE WAKE OF THE
FRONT...COMBINED WITH THE CLOUDS AND RAIN WILL HOLD TEMPERATURES
DOWN ON MONDAY...WITH HIGHS MAINLY IN THE 60S.
AS THE FRONT PULLS EAST OF THE AREA MONDAY NIGHT...HIGH PRESSURE
SETTLES IN FROM THE WEST. MODELS DO SHOW A DECREASE IN THE
CLOUDS...WITH STILL STRONG COLD AIR ADVECTION. TEMPERATURES EXPECTED
TO DROP INTO THE 30S IN MANY LOCATIONS. HOWEVER...MODELS ARE SHOWING
PRESSURE GRADIENT TO REMAIN STRONG ENOUGH TO PRECLUDE THE MENTION
OF FROST...BUT THIS WILL HAVE TO BE WATCHED.
.LONG TERM...TUESDAY THROUGH FRIDAY
305 AM CDT SAT SEP 15 2012
A COOL PERIOD IS IN STORE FOR THE REGION THROUGH THE PERIOD AS THE
PATTERN WILL BE DOMINATED BY NORTHWEST FLOW ALOFT. HIGHS MAY
STRUGGLE TO GET OUT OF THE 50S ON TUESDAY...DESPITE PLENTY OF
SUNSHINE. ANOTHER SHORTWAVE DROPS THROUGH THE FLOW ON WEDNESDAY
PUSHING YET ANOTHER SURFACE BOUNDARY ACROSS THE AREA. SOME SHOWERS
ARE POSSIBLE WITH THE FRONTAL PASSAGE. AS WAVES CONTINUE TO RIDE
THROUGH THE FLOW THURSDAY AND FRIDAY...A LONG WAVE TROUGH DEVELOPS
OVER THE UPPER MIDWEST BY THE END OF THE WEEK. THE ECMWF DOES
DEVELOP A CLOSED 500MB LOW OVER WISCONSIN BY 18Z FRIDAY...WHILE THE
GFS CLOSES THE LOW OFF FURTHER NORTH OVER SOUTHERN ONTARIO. NONE
THE LESS...THE COOL WEATHER WILL CONTINUE WITH A CHANCE OF SHOWERS
OVER PORTIONS OF THE AREA.
&&
.AVIATION...THROUGH 06Z SUNDAY
1149 PM CDT FRI SEP 14 2012
AS EXPECTED...THE DEW POINT RECOVERED BACK INTO THE MID 40S THIS
EVENING...BUT THE TEMP/DEW POINT SPREAD WAS 10 DEGREES AT BOTH 03Z
AND 04Z. WHILE DENSE VALLEY FOG IS STILL POSSIBLE WITH THIS
TEMP/DEW POINT SPREAD IT IS NOT VERY PROBABLE. ALSO...THE WINDS AT
THE SURFACE HAVE ALREADY SWUNG AROUND TO THE SOUTHEAST AND THE
15.00Z NAM AND 15.01Z RAP BUFKIT SOUNDING INDICATE THIS WILL
CONTINUE THROUGH THE NIGHT. THE WINDS AT THE RIDGE TOP LEVEL ARE
EXPECTED TO COME AROUND THE SOUTH/SOUTHWEST OVERNIGHT AND INCREASE
TO A RANGE OF 15 TO 20 KNOTS WHICH WOULD ALSO HELP PREVENT THE FOG
FORMATION. THIS TURNING OF THE WINDS LOOKS TO BE LEGITIMATE AS THE
VWP FROM KMPX SHOWS A TURN TO THE SOUTHWEST HAS OCCURRED THERE.
WILL THUS BACK OUT OF THE FOG SCENARIO FOR KLSE AND GO WITH VFR
CONDITIONS THROUGH THE NIGHT BUT CONTINUE TO INCLUDE BCFG IN THE
EVENT THE WINDS DO NOT COME UP AS EXPECTED. AS THE HIGH CONTINUES
TO PULL AWAY...THE GRADIENT AHEAD OF THE NEXT APPROACHING SYSTEM
WILL INCREASE ENOUGH TO PRODUCE SOME GUSTS AROUND 20 KNOTS
SATURDAY AFTERNOON AT KRST.
&&
.FIRE WEATHER...THIS AFTERNOON
305 PM CDT SAT SEP 15 2012
NEAR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED OVER SOUTHEAST
MINNESOTA AND NORTHEAST IOWA THIS AFTERNOON. AS THE HIGH TRANSLATES
EASTWARD...THE PRESSURE GRADIENT WILL TIGHTEN WITH SOUTHERLY WINDS
GUSTING TO 20-22 MPH. DEW POINTS SHOULD AGAIN LOWER IN THE AFTERNOON
PROVIDING DRY RELATIVE HUMIDITIES IN THE MIDDLE 20S. AT THIS TIME
THE CONDITIONS WILL IMPACT FIRE CONTROL BUT A RED FLAG WARNING WILL
NOT BE NEEDED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
305 AM CDT SAT SEP 15 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RABERDING
LONG TERM...RABERDING
AVIATION...04
FIRE WEATHER...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1150 PM CDT FRI SEP 14 2012
.SHORT TERM...THROUGH MONDAY
325 PM CDT FRI SEP 14 2012
MOST OF THE FORECAST SHIFT WAS SPENT ON EARLY NEXT WEEK AS A
POTENT COLD FRONT MOVES THROUGH. THERE IS SOME CHANCE FOR RIVER
VALLEY FOG SATURDAY MORNING AS WELL. OVERALL THE ONGOING FORECAST
WAS IN GOOD SHAPE AND SMALL CHANGES WERE MADE.
LARGE HEIGHT RISES SEEN TO THE NORTHWEST IN THE MORNING RAOBS
WITH 130M/12HR AT KINL AT 250 MB INDICATIVE OF THE RIDGE BUILDING
TAKING PLACE INTO THE GREAT LAKES FOR THE WEEKEND. THIS RISE IS
LARGE IN EXPANSE AS WELL...ALMOST NORTH TO THE NW TERRITORIES OF
CANADA. LARGEST FALLS HAVE JUST COME INTO BRITISH COLUMBIA THIS
MORNING AND THIS WILL BE THE WEATHER SYSTEM THAT AFFECTS THE AREA
MONDAY. AN UNUSUALLY DRY AIR MASS IS MOVING IN AS WELL WITH 50
PERCENT NORMAL PRECIPITABLE WATER OVER THE ENTIRE NORTHERN PLAINS JUST
NW OF THE AREA.
MODELS IN REMARKABLE AGREEMENT THROUGH THE SHORT TERM WITH ONLY
MINOR TIMING DIFFERENCES NOTED WITH THE FRONT ON MONDAY. THE
PREDICTABILITY SEEMS HIGHER THAN NORMAL.
TONIGHT IS AGAIN A TOUGH VALLEY FOG FORECAST. THE WIND SPEEDS ARE
SINGLE DIGITS IN THE LOWEST 1KM...CLEAR SKIES AND DRY CONDITIONS
ALOFT ALSO ARE EXCELLENT. DEW POINTS HAVE NOT LOWERED TOO MUCH
TODAY AND THIS IS ALSO FAVORABLE...AND THE ONE LIMITING FACTOR WE
HAVE BEEN WATCHING CLOSELY. THERE HAVE BEEN NO DENSE VALLEY FOG
DAYS IN SEPTEMBER WHERE THE 00Z T/TD SPREAD WAS OVER 23F. WE ARE
THINKING IT WILL BE ABOUT 20F AT 00Z. SO...PROBABILITIES SEEM TO
BE INCREASING FOR SATURDAY MORNING VALLEY FOG...LOCALLY
DENSE...AND HAVE STEPPED UP THE COVERAGE IN THE FORECAST.
HAVE TAKEN A STEP TO BUILD SOME TIMING INTO THE PRECIPITATION
SUNDAY NIGHT AND MONDAY. THE 14.12Z MODEL AGREEMENT ON THE RAIN
BAND MOVING IN ASSOCIATED WITH THE CURRENT BRITISH COLUMBIA
SHORTWAVE TROUGH IS VERY GOOD. THERE WAS A SLIGHT INCREASE IN
SPEED AND WHILE SUNDAY REMAINS DRY...IT APPEARS THE AREA IS GOING
TO SEE RAIN SUNDAY NIGHT AND MONDAY. THE STRONG SHORTWAVE TROUGH
WILL HAVE MANY FORCING MECHANISMS FOR LIFT INCLUDING 700-850 MB
FRONTOGENESIS AND UPPER LEVEL JET ENTRANCE REGION DIVERGENCE.
MOISTURE FROM THE SOUTH WILL INCREASE SUNDAY INTO THE
FRONT...INCREASING THE EASE IN PRODUCING RAIN. THE 14.09Z AND
14.15Z SREF REMAIN FAST WITH THE HIGHEST RAIN PROBABILITIES OVER
THE FORECAST AREA SUNDAY NIGHT...AND THUS FELT IT WAS PRUDENT TO
INCREASE THE RAIN CHANCES FOR SW WI BY MONDAY MORNING. BOTTOM
LINE IS THAT TIMING IS STILL SOMEWHAT SHAKY...BUT ALL AREAS WILL
LIKELY SEE RAIN FROM THIS SYSTEM.
SOME INSTABILITY WILL BUILD IN THE WARM SECTOR PRE-FRONTALLY ON
SUNDAY AND ENHANCE THE RAIN CHANCES SUNDAY NIGHT. A GOOD CAPPING
INVERSION REMAINS IN THE PLACE TO LIMIT CONVECTION ON AND AHEAD
OF THE FRONT. SO...DO NOT FEEL SEVERE CHANCES ARE TOO GREAT WITH
WEAKER SHEAR AND SBCAPES IN THE 500 J/KG RANGE. EMBEDDED POST-
FRONTAL THUNDER IS POSSIBLE...BUT NOT A LARGE CONCERN.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
325 PM CDT FRI SEP 14 2012
THIS PERIOD IS DOMINATED BY THE LARGE SCALE TROUGH AND BELOW
NORMAL TEMPERATURES. 850 MB TEMPERATURE ANOMALIES ARE IN THE
2-2.5 RANGE WHICH IS APPROACHING RECORD COLD. CHECKING THE RECORD
LOWS AND LOW MAX TEMPERATURES...WE ARE A HANDFUL OF DEGREES AWAY
NEXT WEEK. WITH THE PROGRESSIVE NORTHWEST FLOW...IDEAL RADIATIVE
COOLING NIGHTS LOOK MINIMAL RIGHT NOW TO TARGET A DAY FOR RECORD
COLD. BUT...PEOPLE WILL NOTICE THIS COLD.
OVERALL WITH THE BAROCLINIC ZONE NEARBY...EACH NW FLOW SHORT WAVE
TROUGH WILL WORK ON THE RIBBON AND THIS DOES CAUSE SOME MODEL
DIFFERENCES. ON TUESDAY...THE 14.12Z GFS IS AN OUTLIER WITH THE
WARMING FROM THE WEST...SUGGESTING HIGHS IN THE MIDDLE 60S.
14.12Z CANADIAN/ECMWF AND 14.00Z ECMWF ARE MUCH SLOWER WITH THE
WARMING AND AFTER A COLD MORNING...HAVE DECIDED TO KEEP HIGHS
ABOUT 5F LOWER THAN GFS SUGGESTIONS. OVERALL WE WILL HAVE
PROGRESSIVE PRECIPITATION CHANCES AND A COLD PERIOD.
&&
.AVIATION...THROUGH 06Z SUNDAY
1149 PM CDT FRI SEP 14 2012
AS EXPECTED...THE DEW POINT RECOVERED BACK INTO THE MID 40S THIS
EVENING...BUT THE TEMP/DEW POINT SPREAD WAS 10 DEGREES AT BOTH 03Z
AND 04Z. WHILE DENSE VALLEY FOG IS STILL POSSIBLE WITH THIS
TEMP/DEW POINT SPREAD IT IS NOT VERY PROBABLE. ALSO...THE WINDS AT
THE SURFACE HAVE ALREADY SWUNG AROUND TO THE SOUTHEAST AND THE
15.00Z NAM AND 15.01Z RAP BUFKIT SOUNDING INDICATE THIS WILL
CONTINUE THROUGH THE NIGHT. THE WINDS AT THE RIDGE TOP LEVEL ARE
EXPECTED TO COME AROUND THE SOUTH/SOUTHWEST OVERNIGHT AND INCREASE
TO A RANGE OF 15 TO 20 KNOTS WHICH WOULD ALSO HELP PREVENT THE FOG
FORMATION. THIS TURNING OF THE WINDS LOOKS TO BE LEGITIMATE AS THE
VWP FROM KMPX SHOWS A TURN TO THE SOUTHWEST HAS OCCURRED THERE.
WILL THUS BACK OUT OF THE FOG SCENARIO FOR KLSE AND GO WITH VFR
CONDITIONS THROUGH THE NIGHT BUT CONTINUE TO INCLUDE BCFG IN THE
EVENT THE WINDS DO NOT COME UP AS EXPECTED. AS THE HIGH CONTINUES
TO PULL AWAY...THE GRADIENT AHEAD OF THE NEXT APPROACHING SYSTEM
WILL INCREASE ENOUGH TO PRODUCE SOME GUSTS AROUND 20 KNOTS
SATURDAY AFTERNOON AT KRST.
&&
.FIRE WEATHER...
325 PM CDT FRI SEP 14 2012
NEAR CRITICAL FIRE WEATHER CONDITIONS ARE STILL EXPECTED OVER
SOUTHEAST MINNESOTA AND NORTHEAST IOWA ON SATURDAY. AS THE HIGH
TRANSLATES EASTWARD...THE PRESSURE GRADIENT WILL TIGHTEN WITH
SOUTHERLY WINDS GUSTING TO 20-22 MPH. DEW POINTS SHOULD AGAIN
LOWER IN THE AFTERNOON PROVIDING DRY RELATIVE HUMIDITIES IN THE
MIDDLE 20S. AT THIS TIME THE CONDITIONS WILL IMPACT FIRE CONTROL
BUT A RED FLAG WARNING IS NOT ANTICIPATED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
325 PM CDT FRI SEP 14 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...04
FIRE WEATHER...RIECK
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
330 AM PDT SAT SEP 15 2012
.SYNOPSIS...
HIGH PRESSURE ALOFT AND OFFSHORE FLOW WILL RESULT IN ANOTHER VERY
HOT DAY TODAY. COOLING WILL BEGIN SUNDAY AS THE HIGH ALOFT WEAKENS
AND SURFACE FLOW BECOMES ONSHORE. LOCAL STRONG AND GUSTY EAST WINDS
WILL CONTINUE THROUGH AND BELOW MOUNTAIN PASSES AND CANYONS OF SAN
DIEGO COUNTY TODAY WITH LOW HUMIDITIES. COOLER WEATHER WILL CONTINUE
MONDAY AND TUESDAY WITH A COASTAL MARINE LAYER. HOWEVER...MOST AREAS
WILL CONTINUE TO HAVE TEMPERATURES ABOVE NORMAL MOST OF NEXT WEEK
DUE TO HIGH PRESSURE ALOFT CONTINUING.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
THE VERY HOT WEATHER IS EXPECTED AGAIN TODAY...WITH TEMPERATURES
SIMILAR TO THOSE OF SATURDAY EXCEPT FOR HIGHER TEMPERATURES ALONG
THE IMMEDIATE COAST DUE TO A BIT MORE EAST FLOW THERE. SO...MOST
AREAS W OF THE MTNS WILL BE 100+...WITH MOSTLY 90S WITHIN A FEW
MILES OF THE COAST BEFORE THE AFTERNOON SEA BREEZE DEVELOPS. GOING
FOR 99 AT KSAN DUE TO MANY BUFKIT PROFILES...INCLUDING
SREF...SHOWING A NEARLY ADIABATIC SOUNDING BELOW 700 MB THROUGH
ABOUT 1 PM WHEN THE SEA BREEZE BEGINS. 06Z LOCAL WRF AND HRRR MODELS
INDICATE GUST POTENTIAL AROUND 35-38 MPH IN THE MTNS/FOOTHILLS
MAINLY OF CENTRAL SAN DIEGO COUNTY...THOUGH THIS IS DOWN SLIGHTLY
FROM PREVIOUS RUNS AS...AT LEAST IN THE WRF...THE 850 MB THERMAL
GRADIENT IS A BIT LESS STRONG OVER THE MTNS THAN PREVIOUSLY
INDICATED. WILL CONTINUE MENTION OF LOCAL GUSTS TO 40 MPH FOR FIRE
WEATHER PURPOSES...SEE FIRE WEATHER SECTION FOR MORE DETAILS.
SUNDAY WILL BE QUITE A CHANGE DUE TO SURFACE ONSHORE FLOW DEVELOPING
REGIONWIDE AND PROBABLY A WEAK EDDY. HENCE...COASTAL AREAS WILL BE
15-20 DEGREES COOLER WITH MOST OTHER AREAS 3 TO 10 DEGREES COOLER.
TIMING OF THE STRATUS WILL BE TRICKY AND BASED ON THE STRENGTH OF
THE EDDY AS THERE IS CURRENTLY STRATUS ALONG THE BAJA COAST STARTING
ABOUT 25 MILES S OF THE US/MEXICO BORDER. FOR NOW...EXPECT
STRATUS/FOG TO MOVE INTO THE COASTAL WATERS SUNDAY AND THEN SPREAD
ONTO LAND SUNDAY EVENING. THERE COULD BE A PERIOD OF DENSE FOG WITH
THE ONSET OF THE STRATUS/FOG...AS IS OFTEN THE CASE WHEN STRATUS/FOG
RETURNS AFTER A HEAT WAVE.
OVERALL...HIGH PRESSURE ALOFT WILL CONTINUE MOST OF NEXT WEEK...WITH
SOME RESTRENGTHENING AROUND WED/THU. THE POSITION OF THE HIGH WILL
BE SIMILAR TO THE CURRENT HIGH BUT NOT QUITE AS STRONG...SO IT WILL
MOST LIKELY NOT BE QUITE AS HOT IN SOCAL AS IT IS NOW. WE WILL HAVE
TO WATCH THE REMNANTS OF TROPICAL STORM KRISTY NOT TOO FAR TO THE
SOUTH/SOUTHWEST AS A LOW TO OUR SOUTH COULD ALLOW FOR SOME OFFSHORE
FLOW TO DEVELOP AND INCREASE TEMPS NEAR THE COAST AROUND
MIDWEEK...THOUGH THIS IS NOT EXPECTED TO BRING ANY SIGNIFICANT
MOISTURE TO THE AREA.
&&
.FIRE WEATHER...
THERE WILL BE AN ELEVATED POTENTIAL FOR WILD FIRE GROWTH THROUGH THIS
AFTERNOON...BUT WIDESPREAD AND PERSISTENT CRITICAL LEVELS ARE NOT
EXPECTED. LOCAL MODELS SHOW PEAK SUSTAINED WIND POTENTIAL THROUGH
AND BELOW THE PASSES AND CANYONS OF THE SAN DIEGO COUNTY MTNS OF 20
TO 30 MPH WITH SOME GUSTS AROUND 40 MPH POSSIBLE IN THE WINDIEST
SPOTS IN THE MID TO LATE MORNING. WINDS WILL BE WEAKER TOWARD THE
COAST. LOWEST RELATIVE HUMIDITIES WILL GENERALLY BE AT LOWER
ELEVATIONS IN THE VALLEYS THAN THE PEAK WINDS...WITH 8 TO 10 PERCENT
IN A FEW LOCATIONS...WITH THE MOUNTAINS HAVING MIN RH VALUES AROUND
10 TO 15 PERCENT...MOSTLY IN THE EARLY AFTERNOON. CRITICAL FIRE
WEATHER CONDITIONS WILL LIKELY DEVELOP LOCALLY FOR A FEW HOURS IN
THE LATE MORNING/EARLY AFTERNOON IN THE SAN DIEGO COUNTY MOUNTAINS
AND FOOTHILLS...MAINLY FROM INTERSTATE 8 NORTH TO HIGHWAY 78...BUT
THESE CONDITIONS ARE NOT EXPECTED TO PERSIST 6 HOURS OR MORE. WINDS
SHOULD WEAKEN GRADUALLY IN THE AFTERNOON AND MORE SUBSTANTIALLY THIS
EVENING. HUMIDITIES WILL BE HIGHER ON SUNDAY DUE TO DEVELOPING
ONSHORE FLOW.
&&
.AVIATION...
150930Z...HIGH PRESSURE OVER THE REGION WILL MAINTAIN VFR CONDS
THROUGH THE TAF PERIOD. OCCASIONAL MODERATE UP/DOWNDRAFTS WILL
ACCOMPANY GUSTY EASTERLY WINDS UP TO 20 KT AT THE SURFACE FOR THE
VALLEYS AND WEST OF THE MTNS THIS AFTERNOON.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
SPECIAL WEATHER STATEMENT FOR HOT WEATHER...SEE LAXSPSSGX.
&&
$$
PUBLIC/FIRE WEATHER...JAD
AVIATION...JJT
AREA FORECAST DISCUSSION
NWS NEW YORK NY
719 AM EDT SAT SEP 15 2012
.SYNOPSIS...
A COLD FRONT WILL PASS THIS MORNING...ALLOWING HIGH PRESSURE TO
BUILD IN THROUGH THE REMAINDER OF THE WEEKEND. AS THE HIGH MOVES
SLOWLY OFF THE COAST MONDAY...AN INTENSIFYING LOW PRESSURE SYSTEM
WILL MOVE NORTHEAST AND MERGE WITH A COLD FRONT AS IT PASSES OVER
THE REGION TUESDAY NIGHT. HIGH PRESSURE WILL MOVE EAST ACROSS THE
AREA WEDNESDAY THROUGH THURSDAY FOLLOWED BY A COLD FRONT LATE
FRIDAY.
&&
.NEAR TERM /UNTIL 11 AM THIS MORNING/...
COLD FRONT AT 6AM WAS CLEARING MONTAUK. LINE OF SHRA TRACKING EWD
THRU CNTRL CT AND CLIPPING LI. POPS UPDATED TO BETTER CAPTURE THIS
BAND. RAPID CLEARING UPSTREAM...SO AFT ANY RAIN FALLS SKIES WILL
CLEAR. THE HRRR WAS FOLLOWED FAIRLY CLOSELY FOR POPS THIS MRNG.
&&
.SHORT TERM /11 AM THIS MORNING THROUGH MONDAY NIGHT/...
MIDWEST HIPRES WILL BUILD INTO THE REGION FOR THE REMAINDER OF
THE WEEKEND. SKIES WILL THEREFORE REMAIN MAINLY CLEAR THRU THE
PERIOD. TEMPS A BLEND OF THE MET/MAV. BREEZY NW FLOW TODAY...BUT
LIGHT WINDS ON SUN.
THE HIGH DRIFTS OFFSHORE ON MON...RESULTING IN DEVELOPING RETURN
FLOW. 00Z MODELS SUPPORT THE CURRENT FCST OF DRY. THERE SHOULD BE
SOME INCREASING HIGH AND POTENTIALLY MID CLOUD COVER FROM THE SW.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
POTENTIAL FOR A SIGNIFICANT STORM TUESDAY THROUGH TUESDAY NIGHT.
00Z MODELS SHOW NO DEVIATION FROM THE STORMY SOLN. TABLE IS SET
SO NO SIGNIFICANT CHANGES WERE MADE TO THE EXTENDED.
FORECAST MODELS SHOW A SHORT WAVE OVER THE SOUTH CENTRAL U.S.
MOVING NE AND AN AMPLIFYING SHORT WAVE MOVING SE TOWARD THE GREAT
LAKES THAT PHASE TOGETHER PRODUCING A FULL AMPLITUDE TROUGH THAT
BECOMES NEGATIVELY TITLED BY TUESDAY NIGHT.
ALTHOUGH THERE ARE ALWAYS DIFFERENCES IN EXACTLY WHERE THE LOW
LEVEL LOW PRES SYSTEM DEVELOPS ALONG WITH ITS AMPLIFICATION AND
SUBSEQUENT TRACK...THERE ARE GROWING SIGNALS OF AN INTENSIFYING
LOW PRES SYSTEM MOVING TO THE N-NE AND PASSING JUST WEST OF THE
AREA LATE TUESDAY.
POTENTIAL IMPACTS ASSOCIATED WITH THIS SYSTEM WOULD INCLUDE SEVERE
TSTMS WITH ISOLATED TORNADOES...FLASH FLOOD PRODUCING
RAINFALL...STRONG GRADIENT WINDS AND COASTAL FLOODING.
AN OUTLOOK FOR THIS STORM WILL BE ISSUED WITH THIS FCST UPDATE.
STAY TUNED.
FAIR WEATHER WILL RETURN ON WEDNESDAY AS HIGH PRESSURE MOVES
TOWARD THE AREA WHICH IS FORECAST TO CONTINUE ON THURSDAY.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
A COLD FRONT WAS EAST OF THE TERMINALS EARLY THIS MORNING. HIGH
PRESSURE WILL BUILD IN THIS AFTERNOON THROUGH SUNDAY.
GENERALLY VFR CONDITIONS...HOWEVER THERE COULD BE LOCAL MARGINAL VFR
CEILINGS AROUND 2K FT AT THE TERMINALS EAST OF NYC THROUGH 13Z.
WINDS WILL BE NORTH TO NORTHWEST WITH GUSTS AROUND 20 KT UNTIL ABOUT
15Z...THEN WINDS WILL REMAIN STRONG THROUGH THE AFTERNOON. WINDS
DIMINISH FARTHER AFTER 00Z.
OUTLOOK FOR 12Z SUNDAY THROUGH WEDNESDAY...
.SUNDAY-MONDAY AFTERNOON...VFR.
.MONDAY NIGHT-TUESDAY NIGHT...IFR/MVFR CONDITIONS WITH WIDESPREAD
SHOWERS AHEAD OF AN APPROACHING WARM FRONT FOLLOWED BY A COLD FRONT.
.WEDNESDAY...CLEARING CONDITIONS AS HIGH PRESSURE BUILDS IN BEHIND
THE COLD FRONT.
&&
.MARINE...
A COLD FRONT MOVES ACROSS THE FORECAST WATERS EARLY THIS MORNING
WITH WINDS SHIFTING TO THE NORTH TO NORTHWEST BEHIND THE FRONT. THIS
AFTERNOON THE FRONT WILL MOVE SLOWLY ONCE IT MOVES EAST OF THE
FORECAST WATERS AND WINDS MAY GUST OCCASIONALLY TO 25 KT ON THE
EASTERN OCEAN WATERS WITH SEAS COMING UP TO CLOSE TO 5 FT LATE THIS
AFTERNOON INTO EARLY THIS EVENING. HIGH PRESSURE BUILDS INTO THE
WATERS LATE THIS AFTERNOON INTO SUNDAY AND WINDS AND SEAS WILL
REMAIN BELOW SMALL CRAFT LEVELS.
&&
.HYDROLOGY...
NO SIGNIFICANT PRECIPITATION IS EXPECTED INTO MONDAY.
MONDAY NIGHT THROUGH TUESDAY NIGHT...THERE IS A POTENTIAL FOR A
WIDESPREAD HEAVY RAINFALL FROM 1 TO 3 INCHES WITH ISOLATED AMOUNTS
OF 4 INCHES LEADING TO MINOR URBAN POOR DRAINAGE FLOODING.
ISOLATED URBAN FLASH FLOODING CANNOT BE RULED OUT. STAY TUNED.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JMC/GC
NEAR TERM...JMC
SHORT TERM...JMC
LONG TERM...JMC/GC
AVIATION...MET
MARINE...MET
HYDROLOGY...JMC/GC
AREA FORECAST DISCUSSION
NWS NEW YORK NY
603 AM EDT SAT SEP 15 2012
.SYNOPSIS...
A COLD FRONT WILL PASS THIS MORNING...ALLOWING HIGH PRESSURE TO
BUILD IN THROUGH THE REMAINDER OF THE WEEKEND. AS THE HIGH MOVES
SLOWLY OFF THE COAST MONDAY...AN INTENSIFYING LOW PRESSURE SYSTEM
WILL MOVE NORTHEAST AND MERGE WITH A COLD FRONT AS IT PASSES OVER
THE REGION TUESDAY NIGHT. HIGH PRESSURE WILL MOVE EAST ACROSS THE
AREA WEDNESDAY THROUGH THURSDAY FOLLOWED BY A COLD FRONT LATE
FRIDAY.
&&
.NEAR TERM /UNTIL 11 AM THIS MORNING/...
COLD FRONT AT 6AM WAS CLEARING MONTAUK. LINE OF SHRA TRACKING EWD
THRU CNTRL CT AND CLIPPING LI. POPS UPDATED TO BETTER CAPTURE THIS
BAND. RAPID CLEARING UPSTREAM...SO AFT ANY RAIN FALLS SKIES WILL
CLEAR. THE HRRR WAS FOLLOWED FAIRLY CLOSELY FOR POPS THIS MRNG.
&&
.SHORT TERM /11 AM THIS MORNING THROUGH MONDAY NIGHT/...
MIDWEST HIPRES WILL BUILD INTO THE REGION FOR THE REMAINDER OF
THE WEEKEND. SKIES WILL THEREFORE REMAIN MAINLY CLEAR THRU THE
PERIOD. TEMPS A BLEND OF THE MET/MAV. BREEZY NW FLOW TODAY...BUT
LIGHT WINDS ON SUN.
THE HIGH DRIFTS OFFSHORE ON MON...RESULTING IN DEVELOPING RETURN
FLOW. 00Z MODELS SUPPORT THE CURRENT FCST OF DRY. THERE SHOULD BE
SOME INCREASING HIGH AND POTENTIALLY MID CLOUD COVER FROM THE SW.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
POTENTIAL FOR A SIGNIFICANT STORM TUESDAY THROUGH TUESDAY NIGHT.
00Z MODELS SHOW NO DEVIATION FROM THE STORMY SOLN. TABLE IS SET
SO NO SIGNIFICANT CHANGES WERE MADE TO THE EXTENDED.
FORECAST MODELS SHOW A SHORT WAVE OVER THE SOUTH CENTRAL U.S.
MOVING NE AND AN AMPLIFYING SHORT WAVE MOVING SE TOWARD THE GREAT
LAKES THAT PHASE TOGETHER PRODUCING A FULL AMPLITUDE TROUGH THAT
BECOMES NEGATIVELY TITLED BY TUESDAY NIGHT.
ALTHOUGH THERE ARE ALWAYS DIFFERENCES IN EXACTLY WHERE THE LOW
LEVEL LOW PRES SYSTEM DEVELOPS ALONG WITH ITS AMPLIFICATION AND
SUBSEQUENT TRACK...THERE ARE GROWING SIGNALS OF AN INTENSIFYING
LOW PRES SYSTEM MOVING TO THE N-NE AND PASSING JUST WEST OF THE
AREA LATE TUESDAY.
POTENTIAL IMPACTS ASSOCIATED WITH THIS SYSTEM WOULD INCLUDE SEVERE
TSTMS WITH ISOLATED TORNADOES...FLASH FLOOD PRODUCING
RAINFALL...STRONG GRADIENT WINDS AND COASTAL FLOODING.
AN OUTLOOK FOR THIS STORM WILL BE ISSUED WITH THIS FCST UPDATE.
STAY TUNED.
FAIR WEATHER WILL RETURN ON WEDNESDAY AS HIGH PRESSURE MOVES
TOWARD THE AREA WHICH IS FORECAST TO CONTINUE ON THURSDAY.
&&
.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
A COLD FRONT CONTINUES TO MOVE EAST AND AT 08Z WAS THROUGH THE
LOWER HUDSON VALLEY AND NYC. THE FRONT IS EXPECTED TO BE EAST OF THE
REGION BY 12Z TONIGHT.
VFR. S-SW FLOW AT 10 KT OR LESS WILL SHIFT TO THE NW AND BECOME
GUSTY BEHIND THE COLD FRONT.
AREAS OF LIGHT SHOWERS MOVING THROUGH THE LOWER HUDSON VALLY AND
INTO NORTHEASTERN NEW JERSEY CONTINUES TO BE LIGHT AND MAY WEAKEN AS
THE AREA SHIFTS EAST WITH THE BETTER FORCING TO THE NORTH. MVFR
CEILINGS WERE OBSERVED IN SOUTHERN CONNECTICUT BUT ARE NOT EXPECTED
AT THE TERMINALS.
NW WINDS INCREASE WITH GUSTS AROUND 20 KT IN THE MORNING. SOME
UNCERTAINTY WITH HOW STRONG WINDS ARE IN THE LOW LEVELS DURING THE
AFTN...BUT THERE IS THE POTENTIAL FOR OCCASIONAL GUSTS AROUND 20 KT
TO CONTINUE THROUGH THE AFTN AS WELL. DUE TO LOWER CONFIDENCE...HAVE
NOT INCLUDED THIS IN THE TAFS.
OUTLOOK FOR 06Z SUNDAY THROUGH WEDNESDAY...
.SATURDAY NIGHT-MONDAY AFTERNOON...VFR.
.MONDAY NIGHT-TUESDAY NIGHT...IFR/MVFR CONDITIONS WITH WIDESPREAD
SHOWERS AHEAD OF AN APPROACHING WARM FRONT FOLLOWED BY A COLD FRONT.
.WEDNESDAY...CLEARING CONDITIONS AS HIGH PRESSURE BUILDS IN BEHIND
THE COLD FRONT.
&&
.MARINE...
A COLD FRONT MOVES ACROSS THE FORECAST WATERS EARLY THIS MORNING
WITH WINDS SHIFTING TO THE NORTH TO NORTHWEST BEHIND THE FRONT. THIS
AFTERNOON THE FRONT WILL MOVE SLOWLY ONCE IT MOVES EAST OF THE
FORECAST WATERS AND WINDS MAY GUST OCCASIONALLY TO 25 KT ON THE
EASTERN OCEAN WATERS WITH SEAS COMING UP TO CLOSE TO 5 FT LATE THIS
AFTERNOON INTO EARLY THIS EVENING. HIGH PRESSURE BUILDS INTO THE
WATERS LATE THIS AFTERNOON INTO SUNDAY AND WINDS AND SEAS WILL
REMAIN BELOW SMALL CRAFT LEVELS.
&&
.HYDROLOGY...
NO SIGNIFICANT PRECIPITATION IS EXPECTED INTO MONDAY.
MONDAY NIGHT THROUGH TUESDAY NIGHT...THERE IS A POTENTIAL FOR A
WIDESPREAD HEAVY RAINFALL FROM 1 TO 3 INCHES WITH ISOLATED AMOUNTS
OF 4 INCHES LEADING TO MINOR URBAN POOR DRAINAGE FLOODING.
ISOLATED URBAN FLASH FLOODING CANNOT BE RULED OUT. STAY TUNED.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JMC/GC
NEAR TERM...JMC
SHORT TERM...JMC
LONG TERM...JMC/GC
AVIATION...MET
MARINE...MET
HYDROLOGY...JMC/GC
AREA FORECAST DISCUSSION...UPDATED
NWS MELBOURNE FL
1138 AM EDT SAT SEP 15 2012
.DISCUSSION...
LARGE CONTINENTAL RIDGE BLANKETING MUCH OF THE ERN SEABOARD WILL
MAINTAIN A DEEP E/NERLY FLOW ACRS CENTRAL FL THRU THE DAY. WINDS
WILL NOT BE QUITE AS STRONG AS FRI AS THE WEAK FRONTAL BNDRY OVER
THE SE CONUS HAS LARGELY BEEN BRIDGED BY THE RIDGE AND WILL NOT PLAY
A DIRECT ROLE FOR CENTRAL FL WX THIS AFTN/EVNG.
MORNING SOUNDINGS SHOW MOISTURE INCREASING FROM N TO S ACRS THE
PENINSULA...PWAT VALUES 1.7" AT KJAX...1.9"-2.0" AT KXMR/KTBW...AND
2.2" AT KMFL. MID LVL LAPSE RATES REMAIN WEAK...BTWN 5.0-5.5C/KM...
THOUGH H50 TEMPS HAVE COOLED SLIGHTLY TO BTWN -7.5C AND -8.0C.
LATEST RAP ANALYSIS SHOWS SOME DRIER AIR JUST OFF THE E FL COAST
WITH H100-H70 MEAN RH BLO 70PCT...H85-H50 MEAN RH BLO 60PCT.
THE LIGHTER WINDS WILL ALLOW THE EAST COAST SEA BREEZE TO FORM WITH
BETTER DEFINITION THAN IN RECENT DAYS. THIS IN TURN WILL ALLOW A FEW
DIURNAL SHRAS TO DVLP INTO TSRAS...WHILE THE WEAKER STEERING FLOW
WILL RESULT IN SLOWER STORM MOTION AND LOCAL HEAVY RAIN. THE FOCUS
FOR SCT SHRAS/ISOLD TSRAS WILL SHIFT TO THE WRN PENINSULA LATE IN
THE DAY. DEEP ONSHORE FLOW WILL KEEP MAX TEMPS IN THE M/U80S COAST
AND U80S/L90S INLAND.
THE GFS SHOWS THE DRIER AIR TRYING TO PUSH INTO THE AREA...WHICH
SHOULD WORK TO LOWER POPS THIS AFTN. WILL LOWER POPS TO 20PCT FOR
COASTAL VOLUSIA AND NRN BREVARD....REMAINDER OF THE FCST LOOKS GOOD.
&&
.AVIATION...
THRU 16/00Z...E/NE SFC WND 8-13KTS...PREVAILING VFR ALL SITES...
BRIEF PDS OF IFR CIGS/VSBYS IN SCT SHRAS/ISOLD TSRA WITH OCNL SFC
WND G22-25KTS. AFT 16/00Z...SFC WND E/NE AOB 5KTS...PREVAILING VFR
ALL SITES...ISOLD IFR CIGS/VSBYS COASTAL SITES.
&&
.MARINE...
LARGE CONTINENTAL RIDGE AXIS CENTERED OVER THE MIDWEST WILL GENERATE
A GENTLE TO MODERATE E/NE SFC/BNDRY LYR BREEZE THRU SUNSET...
LINGERING SWELL WILL KEEP SEAS 3-4FT AREAWIDE. ISOLD SHRAS/TSRAS MVG
ONSHORE. VERY LONG PD SWELLS FROM DISTANT T.C. NADINE WILL BEGIN TO
PROPAGATE INTO THE LCL ATLC THIS AFTN BUT INITIALLY SHOULD GO
UNNOTICED. SWELLS WILL BUILD TONIGHT AND BOOST SEAS TO 5-6FT
OVERNIGHT. THIS WILL GENERATE HAZARDOUS BOATING CONDITIONS NEAR
INLETS BY DAYBREAK SUNDAY.
NOTE TO USERS: NOAA BUOY 41009 HAS BEEN RETURNED TO SERVICE.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECAST/AVIATION...BRAGAW
RADAR/IMPACT WX.....GLITTO
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1015 AM EDT SAT SEP 15 2012
.DISCUSSION...
LARGE CONTINENTAL RIDGE BLANKETING MUCH OF THE ERN SEABOARD WILL
MAINTAIN A DEEP E/NERLY FLOW ACRS CENTRAL FL THRU THE DAY. WINDS
WILL NOT BE QUITE AS STRONG AS FRI AS THE WEAK FRONTAL BNDRY OVER
THE SE CONUS HAS LARGELY BEEN BRIDGED BY THE RIDGE AND WILL NOT PLAY
A DIRECT ROLE FOR CENTRAL FL WX THIS AFTN/EVNG.
MORNING SOUNDINGS SHOW MOISTURE INCREASING FROM N TO S ACRS THE
PENINSULA...PWAT VALUES 1.7" AT KJAX...1.9"-2.0" AT KXMR/KTBW...AND
2.2" AT KMFL. MID LVL LAPSE RATES REMAIN WEAK...BTWN 5.0-5.5C/KM...
THOUGH H50 TEMPS HAVE COOLED SLIGHTLY TO BTWN -7.5C AND -8.0C.
LATEST RAP ANALYSIS SHOWS SOME DRIER AIR JUST OFF THE E FL COAST
WITH H100-H70 MEAN RH BLO 70PCT...H85-H50 MEAN RH BLO 60PCT.
THE LIGHTER WINDS WILL ALLOW THE EAST COAST SEA BREEZE TO FORM WITH
BETTER DEFINITION THAN IN RECENT DAYS. THIS IN TURN WILL ALLOW A FEW
DIURNAL SHRAS TO DVLP INTO TSRAS...WHILE THE WEAKER STEERING FLOW
WILL RESULT IN SLOWER STORM MOTION AND LOCAL HEAVY RAIN. THE FOCUS
FOR SCT SHRAS/ISOLD TSRAS WILL SHIFT TO THE WRN PENINSULA LATE IN
THE DAY. DEEP ONSHORE FLOW WILL KEEP MAX TEMPS IN THE M/U80S COAST
AND U80S/L90S INLAND.
THE GFS SHOWS THE DRIER AIR TRYING TO PUSH INTO THE AREA...WHICH
SHOULD WORK TO LOWER POPS THIS AFTN. WILL LOWER POPS TO 20PCT FOR
COASTAL VOLUSIA AND NRN BREVARD....REMAINDER OF THE FCST LOOKS GOOD.
NOTE TO USERS: THE SOUTHERN REGION SERVER IS CURRENTLY OTS. WITH
THIS OUTAGE...ALL SOUTHERN REGION WEBPAGES ARE UNAVAILABLE.
TECHNICIANS ARE WORKING ON THE PROBLEM...NO RTS ETA AT THIS TIME.
&&
.AVIATION...
THRU 16/00Z...E/NE SFC WND 8-13KTS...PREVAILING VFR ALL SITES...
BRIEF PDS OF IFR CIGS/VSBYS IN SCT SHRAS/ISOLD TSRA WITH OCNL SFC
WND G22-25KTS. AFT 16/00Z...SFC WND E/NE AOB 5KTS...PREVAILING VFR
ALL SITES...ISOLD IFR CIGS/VSBYS COASTAL SITES.
&&
.MARINE...
LARGE CONTINENTAL RIDGE AXIS CENTERED OVER THE MIDWEST WILL GENERATE
A GENTLE TO MODERATE E/NE SFC/BNDRY LYR BREEZE THRU SUNSET...
LINGERING SWELL WILL KEEP SEAS 3-4FT AREAWIDE. ISOLD SHRAS/TSRAS MVG
ONSHORE. VERY LONG PD SWELLS FROM DISTANT T.C. NADINE WILL BEGIN TO
PROPAGATE INTO THE LCL ATLC THIS AFTN BUT INITIALLY SHOULD GO
UNNOTICED. SWELLS WILL BUILD TONIGHT AND BOOST SEAS TO 5-6FT
OVERNIGHT. THIS WILL GENERATE HAZARDOUS BOATING CONDITIONS NEAR
INLETS BY DAYBREAK SUNDAY.
NOTE TO USERS: NOAA BUOY 41009 HAS BEEN RETURNED TO SERVICE.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECAST/AVIATION...BRAGAW
RADAR/IMPACT WX.....GLITTO
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1000 AM CDT SAT SEP 15 2012
.UPDATE...
ISSUED AT 1000 AM CDT SAT SEP 15 2012
RAIN OVER SW MISSOURI IS ENCOUNTERING DRY HIGH PRESSURE AS IT MOVES
EAST INTO THE MISSISSIPPI VALLEY. THE 1000/500 MB LAYER MEAN RH FROM
THE 09Z RUC MODEL APPEARS TO HAVE A GOOD HANDLE ON THE LEADING EDGE
OF THE THICKER OVERCAST AND RAIN AREAS. BASED ON THE RUC MEAN
RH...THE LEADING EDGE WILL DRIFT ONLY SLIGHTLY EASTWARD ACROSS SE
MISSOURI TODAY. UPDATED FORECAST TO SHARPEN THE POP GRADIENT ACROSS
SE MISSOURI. TEMP GRADIENT WAS ALSO SHARPENED...BASED ON THE LARGE
DIFFERENCE IN EXPECTED CLOUDS AND WEATHER ACROSS THE REGION.
&&
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 1218 AM CDT SAT SEP 15 2012
AN UPPER LEVEL CUT OFF LOW REMAINED OVER THE DESERT SOUTHWEST THIS
MORNING. THIS LOW WAS PUMPING UP GULF MOISTURE OVER THROUGH THE
GULF STATES AND INTO AR. A WEAK DIRTY HIGH WAS HOLDING IN PLACE
OVER THE PAH FA KEEPING SHOWERS AT BAY FOR NOW. HOWEVER THIS
CLOSED LOW WILL OPEN UP AND START TO INVADE THE FA AS WE HEAD
THROUGH THE WEEKEND. THE MODELS ARE SHOWING A LATER ONSET FROM ONE
RUN TO THE NEXT AS THE STUBBORN HIGH IS SLOW TO DEPART. HOWEVER
THE HIGH WILL BE FORCED EAST OF THE AREA AS THE UPPER LEVEL OPEN
WAVE MAKES ITS WAY INTO THE HEARTLAND. AS FOR NOW THE SOUTHERN
PORTIONS OF THE AREA WOULD HAVE THE BEST CHANCE AND MOST QPF THIS
WEEKEND. HOWEVER BY MONDAY THIS OPEN WAVE PHASES WITH A SHARPENING
LONG WAVE TROUGH AND KICKS A COLD FRONT THROUGH THE
AREA...RESULTING IN BETTER COVERAGE OF RAIN IN THE FORM OF
THUNDERSTORMS MOST LIKELY MONDAY AND MONDAY NIGHT. CURRENTLY ALL
PARAMETERS ARE SUGGESTING NO SEVERE WX EXPECTED AT THIS TIME.
ONLY MINOR EDITS TO TEMPS FOR COLLAB PURPOSES MAINLY.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 1218 AM CDT SAT SEP 15 2012
THE PATTERN IN THE LONG TERM WILL BE HIGHLY AMPLIFIED AND STAGNANT
WITH A DEEP TROF COVERING MUCH OF THE NORTH CENTRAL U.S. AND GREAT
LAKES REGION...WITH A RIDGE PERSISTENT OVER THE FAR WEST U.S.
DEPARTING MOISTURE TUESDAY MORNING WILL BE FOLLOWED BY DRY WEATHER
THROUGH WEDNESDAY NIGHT. A WEAKENING FRONTAL SYSTEM WILL BRING A
SMALL CHANCE OF CONVECTION TO THE REGION THURSDAY...FOLLOWED BY A
BETTER CHANCE OF CONVECTION THURSDAY NIGHT INTO FRIDAY...WHEN A
STRONG FRONT IS FORECAST TO MOVE THROUGH.
&&
.AVIATION...
ISSUED AT 614 AM CDT SAT SEP 15 2012
CONSIDERABLE HIGH CLOUDS WITH NE WINDS AOB 10 KTS. THERE IS A LOW
PROB OF -SHRA AT KPAH AND KCGI BUT NOT IN THE TAFS AT THIS TIME
GIVEN LOW CONFIDENCE.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...MY
SHORT TERM/LONG TERM...KH/CN
AVIATION...CN
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
955 AM EDT SAT SEP 15 2012
.SYNOPSIS...
A COLD FRONT DRAPED ACROSS THE SAINT LAWRENCE VALLEY WILL CROSS
THE REGION THIS MORNING ACCOMPANIED BY SCATTERED SHOWERS. HIGH
PRESSURE AND DRIER AIR FOLLOWS LATE SATURDAY THROUGH MONDAY. A
WARM FRONT WILL LIFT NORTH THROUGH NEW ENGLAND TUESDAY WHILE LOW
PRESSURE LIFTS NORTH OF THE REGION. DRIER AIR FILTERS IN WEDNESDAY
THROUGH FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
.UPDATE...A LINE OF SHOWERS ALONG A COLD FRONT CONTINUES TO PUSH
EAST THIS MORNING. A FEW CONVECTIVE CELLS ARE TRYING TO GET GOING
IN WEAK CAPE NEAR SKOWHEGAN. NOT EXPECTING MUCH TO COME OF THIS
BUT INCLUDED ISOLATED LIGHTNING FOR A COUPLE HOURS. HRRR GENERATES
A FEW MORE HOURS OF SHOWERS BUT THIS MAY BE OVERDONE. THERE IS AN
AREA OF CLEARING BEHIND THE BOUNDARY BUT IT QUICKLY FILLED IN WITH
COLD AIR STRATUS WHICH IS PUSHING SOUTHEAST OUT OF VERMONT AND NY.
WINDS ARE GUSTING INTO THE UPPER TEENS AND LOWER 20S. UPDATED THE
FORECAST TO REFLECT CURRENT CONDITIONS AND TREND POPS EAST.
&&
PREVIOUS DISCUSSION...COLD FNT IS APPROACHING WRN PORTIONS OF
THE CWFA ATTM...WITH MOSTLY POST FRONTAL PCPN. REGIONAL 88DS ARE
SHOWING A LOT MORE BARK THAN BITE WITH THE FRONTAL PCPN. WHILE
THERE IS A CONCENTRATED BAND ADVANCING EWD...WITH EMBEDDED ECHOES
ON THE ORDER OF 40 DBZ...MUCH OF THIS IS FAILING TO REACH THE
GROUND. SEEING A LOT OF 10SM -RA FROM REGIONAL METAR OBS...WITH
HEAVIEST RAFL...AROUND A TENTH...OCCURRING INVOF KALB. SOME OF
THIS MAY HOLD TOGETHER INTO SRN NH...BUT EXPECT A CONTINUED
WEAKENING TREND THRU THE EARLY MORNING. WITH RA STRUGGLING TO
AMOUNT TO MORE THAN A TRACE PCPN...HAVE KEPT POP BLO LIKELY...WITH
HIGHEST CHC IN THE MTNS.
ONCE FNT CROSSES THE CWFA...WILL SEE RAPID CLEARING OUTSIDE OF THE
MTNS FROM SW TO NE. CAA AND DIURNAL HEATING WILL PROMOTE BOUNDARY
LAYER MIXING AND HELP 20-25 KT WIND GUSTS REACH THE SFC THIS AFTN.
BUOYS OFF OSWEGO NY ARE GUSTING TO NEAR 25 KT ATTM...SUPPORTING
SIMILAR VALUES OVER LAND TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
THE REGION WILL REMAIN UNDER CYCLONIC FLOW ALOFT TNGT...WHILE SFC
SYSTEM LIFTS WELL TO THE NE. LACK OF DEEP MOISTURE WILL PRECLUDE
MUCH IN THE WAY OF CLOUDS IN THE MTNS PAST THIS AFTN. SO EXPECTING
CLEAR SKIES...AND A WEAKENING GRADIENT THRU THE NGT. THIS WILL
ALLOW EFFICIENT RADIATIONAL COOLING...WITH READINGS IN THE LOW TO
MID 30S IN THE NRN MTNS. HAVE GONE WITH A FROST ADVISORY FOR THE
ZONES MOST LIKELY TO SEE WIDESPREAD FROST.
AS HIGH PRES BUILDS EWD...QUIET AND SUNNY DAY EXPECTED FOR SUN.
WILL STILL SEE SOME GUSTY WINDS AS BOUNDARY LAYER MIXES OUT DURING
THE DAY. OTHERWISE...NEAR 70 FOR THE COASTAL AREAS AND 60S FOR
MTNS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
MAINLY CLEAR AND QUIET CONDITIONS ARE EXPECTED TO CONTINUE DURING
THE PERIOD SUNDAY NIGHT INTO MONDAY. A LARGE AREA OF SURFACE HIGH
PRESSURE WILL GRADUALLY EASE OFF THE COAST DURING THIS PERIOD.
THEREAFTER...THE FLOW BECOME MERIDIONAL WITH TIME AS LOW PRESSURE
INTENSIFIES AND PASSES BY TO OUR WEST ON TUESDAY. THIS WILL SET UP
A STRONG AND VERY MOIST SOUTHERLY FLOW FROM THE ATLANTIC WATERS.
HIGHEST QPF IS EXPECTED WEST OF OUR REGION...BUT WE ARE STILL
ANTICIPATING SOME WELL NEEDED RAINFALL...MAINLY TUESDAY NIGHT.
LOW PRESSURE WILL CONTINUE TO INTENSIFY AS IT MOVES INTO CANADA
WEDNESDAY...DRAGGING A COLD FRONT THROUGH NORTHERN NEW ENGLAND.
THE CANADIAN GEM IS THE SLOWEST MODEL BRINGING THE CLOUDS AND SCT
-SHRA OFF THE COAST WEDNESDAY MORNING. THIS APPEARS TO BE A
REASONABLE SOLUTION CONSIDERING THE UPPER LEVEL TROUGH REMAINS WELL
TO THE WEST BY 12Z WEDNESDAY.
AFTER SOME DRY AND CHILLY WEATHER CONDITIONS THURSDAY AND
FRIDAY...A LARGE UPPER LEVEL LOW PRESSURE SYSTEM WILL GRADUALLY
APPROACH FROM THE WEST BY NEXT WEEKEND. THIS WILL BRING MORE
UNSETTLED CONDITIONS BACK TO THE REGION.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM...LOCAL IFR/LIFR PSBL WITH LOW CLOUDS/FOG AHEAD OF COLD
FNT. COULD SEE ISOLD MVFR CONDS IN SHRA ALONG FNT...THEN RAPID
CLEARING TO VFR CONDS EXPECTED BEHIND IT. WILL SEE CLOUDS ACROSS
THE NRN MTNS...BUT LACK OF APPRECIABLE MOISTURE SHOULD KEEP CIGS
ABV 3KFT. GUSTY WLY WINDS EXPECTED THIS AFTN..AOA 20 KT.
LONG TERM...VFR SUNDAY NIGHT AND MONDAY. CONDITIONS WILL
DETERIORATE TO IFR AND LIFR IN RAIN AND FOG TUESDAY AND WEDNESDAY
FROM WEST TO EAST AS A WARM FRONT LIFTS THROUGH THE AREA.
THEREAFTER...CONDITIONS IMPROVE TO VFR.
&&
.MARINE...
SHORT TERM...WINDS AND SEAS WILL BUILD THIS AFTN AS COLD FNT
CROSSES THE WATERS. ATTM WINDS LOOK TO REMAIN JUST BLO SCA
THRESHOLDS...THOUGH SEAS COULD BUILD ABV 5 FT ON THE OUTER WATERS
LATE TNGT.
LONG TERM...WINDS AND SEAS MAY INCREASE TO NEAR SCA CONDITIONS
TUESDAY AFTERNOON INTO WEDNESDAY AS LOW PRESSURE PASSES JUST NORTH
OF THE WATERS...PRODUCING A GUSTY AND PERSISTENT SOUTHERLY FLOW.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...FROST ADVISORY FROM MIDNIGHT TONIGHT TO 7 AM EDT SUNDAY FOR
MEZ007-008-012.
NH...FROST ADVISORY FROM MIDNIGHT TONIGHT TO 7 AM EDT SUNDAY FOR
NHZ001>004.
MARINE...NONE.
&&
$$
UPDATE...HANES
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1053 AM EDT SAT SEP 15 2012
.SYNOPSIS...
ISSUED AT 341 AM EDT SAT SEP 15 2012
OUTSTANDING WEATHER IS EXPECTED THIS WEEKEND AS HIGH PRESSURE SLIDES
ACROSS THE GREAT LAKES. THE NEXT COLD FRONT WILL MOVE THROUGH ON
MONDAY...BRINGING THE NEXT CHANCE OF RAIN. LAKE EFFECT RAIN SHOWERS
MAY DEVELOP TUESDAY...AS MUCH COOLER AIR INVADES THE REGION.
&&
.UPDATE...
ISSUED AT 1052 AM EDT SAT SEP 15 2012
HIGH PRESSURE CENTERED RIGHT OVER MICHIGAN THIS MORNING. SOME
EARLY HIGHER ELEVATION FOG/STRATUS HAS BEEN THINNING...WITH
DIURNAL CU DEVELOPMENT EXPECTED BY MIDDAY. LIGHT WINDS TODAY WITH
LAKE BREEZES BEING FAIRLY UBIQUITOUS...AFTERNOON HIGHS MOSTLY IN
THE 60S/NEAR 70S ACROSS PARTS OF NORTHWEST LOWER.
UPDATE ISSUED AT 640 AM EDT SAT SEP 15 2012
BROKEN LAKE CLOUDS CONTINUE TO ROLL IN OFF LAKES MICHIGAN AND
HURON WITHIN A DRYING NORTHERLY FLOW. THESE CLOUDS ARE RATHER
THIN...AND DO NOT EXPECTED THEM TO LAST TOO MUCH AFTER SUNRISE
DUE TO MIXING INTO DRIER AIR. STILL LOOKING FOR A GOOD DEAL OF
SUNSHINE TODAY WITH LIGHT WINDS/AFTERNOON LAKE BREEZES.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 341 AM EDT SAT SEP 15 2012
SHARP UPPER TROUGH WORKING INTO NEW ENGLAND WITH A SOLID NW FLOW
ALOFT OVER NRN MICHIGAN. ATMOSPHERIC SUBSIDENCE WITH DRY AIR
ADVECTION WITHIN ADVANCING SFC HIGH PRESSURE. STILL...VERY GOOD
OVERLAKE INSTABILITY HAS LED TO THE DEVELOPMENT OF STRATO CU IN
BACKING NW-W 1000-850MB FLOW...ATTACHED TO GREEN BAY. WINDS ARE
WEAKENING WITH TIME...SO FETCH AND INLAND PENETRATION WILL
CONTINUE LEAD TO LESS CLOUD...BUT THIS MAY TAKE THROUGH EARLY
DAYBREAK...WHEN MIXING INTO DRIER AIR ALOFT CAN HELP MIX IT ALL
OUT. TEMPERATURES WERE QUITE CHILLY...DIPPING INTO THE 30S IN
SEVERAL LOCALES OF NRN LOWER. SKIES WERE FAIRLY CLEAR ACROSS
EASTERN UPPER...WITH LATEST RUC ANALYSIS SUGGESTING A WEAKER WIND
FLOW AND LESS MOISTURE FLUX OFF WHITEFISH BAY/EASTERN LAKE
SUPERIOR. CANNOT RULE OUT SOME STRATO CU INTO CHIPPEWA COUNTY
THOUGH OVER THE NEXT FEW HOURS.
TODAY AND TONIGHT...VERY QUIET. SFC HIGH PRESSURE WILL MOVE IN
OVERHEAD WITH SOME SCATTERED CUMULUS DEVELOPMENT...MAINLY ALONG
THE AXIS OF THE SFC HIGH...AND AREAS EAST. THIS BRINGS THE BETTER
CU ACROSS NE LOWER AND EASTERN CHIP/MACK. BY LATER THIS
AFTERNOON...SOME LAKE BREEZES WILL TRY TO CONSOLIDATE THIS CLOUD
MORE INLAND. THE CLOUDS WILL QUICKLY ERODE TO CLEAR SKIES IN THE
EVENING WITH ONLY SOME SCATTERED MID CLOUD POSSIBLE OVERNIGHT.
THIS WILL BE AHEAD OF A WEAK SHORTWAVE AND LOW LEVEL WARM FRONT
LIFTING OUR WAY. A 30-35KT WSW ORIENTED LLJ COULD THEORETICALLY
RESULT IN SOME THIN CLOUDINESS LATE. WOULD HEDGE MY BETS ON A
FAIRLY CLEAR EVENING THOUGH. LOW TEMPS LIKELY IN THE LOW TO MID
40S WEST/NW CWA IN BETTER SW FLOW DEVELOPING...WITH THE COLDEST
MID TO UPPER 30S IN LOW LYING AREAS OF THE EASTERN CWA OF NRN
LOWER.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 341 AM EDT SAT SEP 15 2012
HIGH PRESSURE AT THE SURFACE AND ALOFT SUNDAY IS EXPECTED TO LEAD TO
VERY PLEASANT WEATHER FOR THE LAST SUNDAY OF SUMMER (THE AUTUMNAL
EQUINOX IS EARLY SATURDAY MORNING ON SEPTEMBER 22ND). A COLD FRONT
WILL THEN MOVE ACROSS THE REGION LATER MONDAY SETTING THE STAGE FOR
LONG WAVE TROUGHING TO SETTLE INTO THE REGION FOR MUCH OF NEXT WEEK.
THIS WILL LEAD TO AN EXTENDED PERIOD OF COOLER AND UNSETTLED
WEATHER. THE MAIN LONG TERM FORECAST CONCERNS REVOLVE AROUND POPS
FOR ALL OF NEXT WEEK.
SUNDAY...SURFACE HIGH PRESSURE SHIFTS OFF TO OUR EAST WHILE UPPER
LEVEL HEIGHTS MAX/FLATTEN OUT. THIS IS EXPECTED TO LEAD TO LOTS OF
SUNSHINE AND MILD TEMPERATURES WITH HIGHS RANGING FROM THE MIDDLE
70S TO LOWER 80S.
SUNDAY NIGHT INTO MONDAY NIGHT...PARTLY CLOUDY SKIES WITH MILDER
TEMPERATURES SUNDAY NIGHT AS SOUTHWEST WINDS STAY UP A BIT. A COLD
FRONT MOVES ACROSS THE REGION LATER MONDAY LIKELY BRINGING SHOWERS.
LOWS SUNDAY NIGHT IN THE 50S WITH HIGHS ON MONDAY RANGING FROM THE
MIDDLE AND UPPER 60S NORTH TO THE MIDDLE AND UPPER 70S SOUTHEAST.
LOWS MONDAY NIGHT IN THE MIDDLE 40S TO LOWER 50S.
TUESDAY...HEIGHTS CONTINUE TO FALL AND COMBINE WITH INCREASING OVER
LAKE INSTABILITY (AS 850 MB TEMPERATURES FALL TO BETWEEN ZERO AND -2
C) AND A SHORT WAVE MOVING THROUGH THE FLOW TO PRODUCE A CHANCE OF
RAIN SHOWERS. THE MEAN FLOW APPEARS TO BE NORTH OR NORTH NORTHWEST
SO LOCALS NEAR THE LAKE SHORES WILL LIKELY HAVE THE BEST SHOT OF
RAIN. HIGHS RANGING FROM THE MUCH COOLER LOWER 50S NORTH TO AROUND
60 SOUTHEAST.
TUESDAY NIGHT...A WEDGE OF DRIER AIR IN COMBINATION WITH HIGH
PRESSURE NOSING IN FROM THE NORTH WILL SET THE STAGE FOR A VERY
CHILLY NIGHT. IF WINDS DECOUPLE...AND RIGHT NOW IT LOOKS LIKE THEY
WILL...THIS COULD LEAD TO THE FIRST SIGNIFICANT FROST OR FREEZE OF
THE SEASON.
WEDNESDAY THROUGH FRIDAY...ENERGY RIDING SOUTHEAST ON THE BACKSIDE
OF A BLOSSOMING PACIFIC RIDGE AMPLIFIES THE LONG WAVE TROUGH ACROSS
THE GREAT LAKES. SO THIS IN COMBINATION WITH PERIODIC SHORT WAVES
MOVING THROUGH THE FLOW AND INCREASING OVER LAKE INSTABILITY BRINGS
MORE CHANCES FOR RAIN SHOWERS. THE DETAILS OF WHICH WILL NEED TO BE
WORKED OUT BY FUTURE SHIFTS. HIGHS GENERALLY RANGING FROM THE MIDDLE
50S TO THE MIDDLE 60S. LOWS IN THE UPPER 30S AND 40S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 640 AM EDT SAT SEP 15 2012
LOW LEVEL BKN MVFR LAKE CLOUDS WILL CONTINUE TO AFFECT THE
TVC/PLN/APN AREAS THROUGH AN HOUR OR TWO AFTER SUNRISE...AND WILL
BE HANDLED BY A TEMPO GROUP. HIGH PRESSURE STILL SETTLES IN FOR
TODAY AND TONIGHT...AND MIXING INTO DRIER AIR WILL RESULT IN JUST
SOME SCATTERED CU THIS AFTERNOON. THESE CLOUDS WILL LIKELY DEPART
THE AIRPORTS BY LATE AFTERNOON DUE TO LAKE BREEZE DEVELOPMENT. CALM
WINDS TONIGHT WITH ONLY THE CHANCE FOR SCATTERED LOW TO MID
CLOUDS. MAINLY CLEAR THOUGH.
&&
.MARINE...
ISSUED AT 159 AM EDT SAT SEP 15 2012
DROPPED SMALL CRAFT ADVISORY ACROSS THE NE LOWER NEARSHORE WATERS
UNDER A WEAKENING LOW LEVEL WIND FIELD...WITH SUPPORT FROM LATEST
MARINE OBS. THIS DESPITE GOOD OVERLAKE INSTABILITY...BUT GUSTY
WINDS ARE LIKELY...ESPECIALLY OVER LAKE HURON. HIGH PRESSURE WILL
THEN SETTLE INTO THE REGION TODAY FOR ONSHORE LAKE BREEZES IN THE
AFTERNOON. THIS HIGH EXITS EAST TONIGHT WITH SOUTHERLY WINDS
RETURNING. THERE IS AN OUTSIDE CHANCE AT SOME LOW END ADVISORY
LEVEL WINDS IN COASTAL CONVERGENCE REGIONS FROM MANISTEE THROUGH
THE MANITOU ISLANDS. CONFIDENCE IS LOW AT THIS POINT...ESPECIALLY
WITH LOW LEVEL WARMING AND INCREASING STABILITY. THESE SAME
ADVISORY POSSIBILITIES CONTINUE THROUGH SUNDAY NIGHT IN ADVANCE OF
THE NEXT LOW PRESSURE AND COLD FRONT WHICH PASSES MONDAY.
INSTABILITY OVER THE LAKES INCREASES RELATIVELY SUBSTANTIALLY
BEHIND THIS FRONT FOR WHAT COULD VERY WELL TURN OUT TO BE THE
BETTER CHANCES FOR ADVISORIES. UNSTABLE CONDITIONS ARE EXPECTED TO
HOLD FROM MONDAY NIGHT ALL THE WAY THROUGH NEXT WORK WEEK AND
POSSIBLY NEXT WEEKEND.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JB
SYNOPSIS...AS
SHORT TERM...SD
LONG TERM...AS
AVIATION...SD
MARINE...SD
AREA FORECAST DISCUSSION
NWS GAYLORD MI
648 AM EDT SAT SEP 15 2012
.SYNOPSIS...
ISSUED AT 341 AM EDT SAT SEP 15 2012
OUTSTANDING WEATHER IS EXPECTED THIS WEEKEND AS HIGH PRESSURE SLIDES
ACROSS THE GREAT LAKES. THE NEXT COLD FRONT WILL MOVE THROUGH ON
MONDAY...BRINGING THE NEXT CHANCE OF RAIN. LAKE EFFECT RAIN SHOWERS
MAY DEVELOP TUESDAY...AS MUCH COOLER AIR INVADES THE REGION.
&&
.UPDATE...
ISSUED AT 640 AM EDT SAT SEP 15 2012
BROKEN LAKE CLOUDS CONTINUE TO ROLL IN OFF LAKES MICHIGAN AND
HURON WITHIN A DRYING NORTHERLY FLOW. THESE CLOUDS ARE RATHER
THIN...AND DO NOT EXPECTED THEM TO LAST TOO MUCH AFTER SUNRISE
DUE TO MIXING INTO DRIER AIR. STILL LOOKING FOR A GOOD DEAL OF
SUNSHINE TODAY WITH LIGHT WINDS/AFTERNOON LAKE BREEZES.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 341 AM EDT SAT SEP 15 2012
SHARP UPPER TROUGH WORKING INTO NEW ENGLAND WITH A SOLID NW FLOW
ALOFT OVER NRN MICHIGAN. ATMOSPHERIC SUBSIDENCE WITH DRY AIR
ADVECTION WITHIN ADVANCING SFC HIGH PRESSURE. STILL...VERY GOOD
OVERLAKE INSTABILITY HAS LED TO THE DEVELOPMENT OF STRATO CU IN
BACKING NW-W 1000-850MB FLOW...ATTACHED TO GREEN BAY. WINDS ARE
WEAKENING WITH TIME...SO FETCH AND INLAND PENETRATION WILL
CONTINUE LEAD TO LESS CLOUD...BUT THIS MAY TAKE THROUGH EARLY
DAYBREAK...WHEN MIXING INTO DRIER AIR ALOFT CAN HELP MIX IT ALL
OUT. TEMPERATURES WERE QUITE CHILLY...DIPPING INTO THE 30S IN
SEVERAL LOCALES OF NRN LOWER. SKIES WERE FAIRLY CLEAR ACROSS
EASTERN UPPER...WITH LATEST RUC ANALYSIS SUGGESTING A WEAKER WIND
FLOW AND LESS MOISTURE FLUX OFF WHITEFISH BAY/EASTERN LAKE
SUPERIOR. CANNOT RULE OUT SOME STRATO CU INTO CHIPPEWA COUNTY
THOUGH OVER THE NEXT FEW HOURS.
TODAY AND TONIGHT...VERY QUIET. SFC HIGH PRESSURE WILL MOVE IN
OVERHEAD WITH SOME SCATTERED CUMULUS DEVELOPMENT...MAINLY ALONG
THE AXIS OF THE SFC HIGH...AND AREAS EAST. THIS BRINGS THE BETTER
CU ACROSS NE LOWER AND EASTERN CHIP/MACK. BY LATER THIS
AFTERNOON...SOME LAKE BREEZES WILL TRY TO CONSOLIDATE THIS CLOUD
MORE INLAND. THE CLOUDS WILL QUICKLY ERODE TO CLEAR SKIES IN THE
EVENING WITH ONLY SOME SCATTERED MID CLOUD POSSIBLE OVERNIGHT.
THIS WILL BE AHEAD OF A WEAK SHORTWAVE AND LOW LEVEL WARM FRONT
LIFTING OUR WAY. A 30-35KT WSW ORIENTED LLJ COULD THEORETICALLY
RESULT IN SOME THIN CLOUDINESS LATE. WOULD HEDGE MY BETS ON A
FAIRLY CLEAR EVENING THOUGH. LOW TEMPS LIKELY IN THE LOW TO MID
40S WEST/NW CWA IN BETTER SW FLOW DEVELOPING...WITH THE COLDEST
MID TO UPPER 30S IN LOW LYING AREAS OF THE EASTERN CWA OF NRN
LOWER.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 341 AM EDT SAT SEP 15 2012
HIGH PRESSURE AT THE SURFACE AND ALOFT SUNDAY IS EXPECTED TO LEAD TO
VERY PLEASANT WEATHER FOR THE LAST SUNDAY OF SUMMER (THE AUTUMNAL
EQUINOX IS EARLY SATURDAY MORNING ON SEPTEMBER 22ND). A COLD FRONT
WILL THEN MOVE ACROSS THE REGION LATER MONDAY SETTING THE STAGE FOR
LONG WAVE TROUGHING TO SETTLE INTO THE REGION FOR MUCH OF NEXT WEEK.
THIS WILL LEAD TO AN EXTENDED PERIOD OF COOLER AND UNSETTLED
WEATHER. THE MAIN LONG TERM FORECAST CONCERNS REVOLVE AROUND POPS
FOR ALL OF NEXT WEEK.
SUNDAY...SURFACE HIGH PRESSURE SHIFTS OFF TO OUR EAST WHILE UPPER
LEVEL HEIGHTS MAX/FLATTEN OUT. THIS IS EXPECTED TO LEAD TO LOTS OF
SUNSHINE AND MILD TEMPERATURES WITH HIGHS RANGING FROM THE MIDDLE
70S TO LOWER 80S.
SUNDAY NIGHT INTO MONDAY NIGHT...PARTLY CLOUDY SKIES WITH MILDER
TEMPERATURES SUNDAY NIGHT AS SOUTHWEST WINDS STAY UP A BIT. A COLD
FRONT MOVES ACROSS THE REGION LATER MONDAY LIKELY BRINGING SHOWERS.
LOWS SUNDAY NIGHT IN THE 50S WITH HIGHS ON MONDAY RANGING FROM THE
MIDDLE AND UPPER 60S NORTH TO THE MIDDLE AND UPPER 70S SOUTHEAST.
LOWS MONDAY NIGHT IN THE MIDDLE 40S TO LOWER 50S.
TUESDAY...HEIGHTS CONTINUE TO FALL AND COMBINE WITH INCREASING OVER
LAKE INSTABILITY (AS 850 MB TEMPERATURES FALL TO BETWEEN ZERO AND -2
C) AND A SHORT WAVE MOVING THROUGH THE FLOW TO PRODUCE A CHANCE OF
RAIN SHOWERS. THE MEAN FLOW APPEARS TO BE NORTH OR NORTH NORTHWEST
SO LOCALS NEAR THE LAKE SHORES WILL LIKELY HAVE THE BEST SHOT OF
RAIN. HIGHS RANGING FROM THE MUCH COOLER LOWER 50S NORTH TO AROUND
60 SOUTHEAST.
TUESDAY NIGHT...A WEDGE OF DRIER AIR IN COMBINATION WITH HIGH
PRESSURE NOSING IN FROM THE NORTH WILL SET THE STAGE FOR A VERY
CHILLY NIGHT. IF WINDS DECOUPLE...AND RIGHT NOW IT LOOKS LIKE THEY
WILL...THIS COULD LEAD TO THE FIRST SIGNIFICANT FROST OR FREEZE OF
THE SEASON.
WEDNESDAY THROUGH FRIDAY...ENERGY RIDING SOUTHEAST ON THE BACKSIDE
OF A BLOSSOMING PACIFIC RIDGE AMPLIFIES THE LONG WAVE TROUGH ACROSS
THE GREAT LAKES. SO THIS IN COMBINATION WITH PERIODIC SHORT WAVES
MOVING THROUGH THE FLOW AND INCREASING OVER LAKE INSTABILITY BRINGS
MORE CHANCES FOR RAIN SHOWERS. THE DETAILS OF WHICH WILL NEED TO BE
WORKED OUT BY FUTURE SHIFTS. HIGHS GENERALLY RANGING FROM THE MIDDLE
50S TO THE MIDDLE 60S. LOWS IN THE UPPER 30S AND 40S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 640 AM EDT SAT SEP 15 2012
LOW LEVEL BKN MVFR LAKE CLOUDS WILL CONTINUE TO AFFECT THE
TVC/PLN/APN AREAS THROUGH AN HOUR OR TWO AFTER SUNRISE...AND WILL
BE HANDLED BY A TEMPO GROUP. HIGH PRESSURE STILL SETTLES IN FOR
TODAY AND TONIGHT...AND MIXING INTO DRIER AIR WILL RESULT IN JUST
SOME SCATTERED CU THIS AFTERNOON. THESE CLOUDS WILL LIKELY DEPART
THE AIRPORTS BY LATE AFTERNOON DUE TO LAKE BREEZE DEVELOPMENT. CALM
WINDS TONIGHT WITH ONLY THE CHANCE FOR SCATTERED LOW TO MID
CLOUDS. MAINLY CLEAR THOUGH.
&&
.MARINE...
ISSUED AT 159 AM EDT SAT SEP 15 2012
DROPPED SMALL CRAFT ADVISORY ACROSS THE NE LOWER NEARSHORE WATERS
UNDER A WEAKENING LOW LEVEL WIND FIELD...WITH SUPPORT FROM LATEST
MARINE OBS. THIS DESPITE GOOD OVERLAKE INSTABILITY...BUT GUSTY
WINDS ARE LIKELY...ESPECIALLY OVER LAKE HURON. HIGH PRESSURE WILL
THEN SETTLE INTO THE REGION TODAY FOR ONSHORE LAKE BREEZES IN THE
AFTERNOON. THIS HIGH EXITS EAST TONIGHT WITH SOUTHERLY WINDS
RETURNING. THERE IS AN OUTSIDE CHANCE AT SOME LOW END ADVISORY
LEVEL WINDS IN COASTAL CONVERGENCE REGIONS FROM MANISTEE THROUGH
THE MANITOU ISLANDS. CONFIDENCE IS LOW AT THIS POINT...ESPECIALLY
WITH LOW LEVEL WARMING AND INCREASING STABILITY. THESE SAME
ADVISORY POSSIBILITIES CONTINUE THROUGH SUNDAY NIGHT IN ADVANCE OF
THE NEXT LOW PRESSURE AND COLD FRONT WHICH PASSES MONDAY.
INSTABILITY OVER THE LAKES INCREASES RELATIVELY SUBSTANTIALLY
BEHIND THIS FRONT FOR WHAT COULD VERY WELL TURN OUT TO BE THE
BETTER CHANCES FOR ADVISORIES. UNSTABLE CONDITIONS ARE EXPECTED TO
HOLD FROM MONDAY NIGHT ALL THE WAY THROUGH NEXT WORK WEEK AND
POSSIBLY NEXT WEEKEND.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...SD
SYNOPSIS...AS
SHORT TERM...SD
LONG TERM...AS
AVIATION...SD
MARINE...SD
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
925 AM MDT SAT SEP 15 2012
.DISCUSSION...
UPDATE FORTHCOMING. HAVE ADJUSTED POPS AND WEATHER GRIDS ALONG THE
HI-LINE THIS MORNING. BOTH THE GFS AND EUROPEAN MODELS DEVELOP A
LITTLE QPF ACROSS THE HI-LINE AS WEAK SHORTWAVE ENERGY PROPAGATES
EASTWARD WITHIN THE FLOW ALOFT. HRRR ANALYSIS ALSO HINTS AT A FEW
WEAK RETURNS DURING THE MORNING HOURS. LITTLE...IF
ANY...ACCUMULATION EXPECTED. REMAINDER OF FORECAST LOOKS ON TRACK.
EMANUEL
&&
.AVIATION...
UPDATED 1110Z.
EXPECT VFR CONDITIONS WITH THE EXCEPTION OF LOCAL MVFR VISIBILITIES
IN SMOKE OVER SOUTHWEST MONTANA. A COLD FRONT WILL SWEEP SOUTH THIS
MORNING SHIFTING WINDS TO THE NORTHWEST TO NORTH. HAVE ONLY FAIR
CONFIDENCE IN THE TIMING OF THE WIND SWITCH ALONG WITH FORECAST
DIRECTIONS. CEILINGS SHOULD GENERALLY BE ABOVE 12000 FT INTO
TONIGHT. AHEAD OF A CANADIAN WEATHER SYSTEM A FEW SHOWERS WILL
DEVELOP IN THE NORTH AFTER MIDNIGHT AND COULD SEE CEILINGS LOWER TO
NEAR 5000 FT WITH THE SHOWERS. BLANK
&&
.PREV DISCUSSION...ISSUED 326 AM MDT SAT SEP 15 2012
SATURDAY THROUGH MONDAY...
WINDS WILL AGAIN DEVELOP TODAY AS A COLD FRONT APPROACHES AND
EVENTUALLY MOVES ACROSS THE AREA. MODELS STILL VARY ON TIMING OF
THE FRONT ACROSS THE AREA...HOWEVER IT SHOULD MOVE ACROSS MOST OF
CENTRAL AND NORTH CENTRAL MONTANA TO LIMIT MAXIMUM TEMPERATURES
TODAY INTO THE UPPER 70S AND LOW 80S. WINDS WILL BE BREEZY AT
TIMES...HOWEVER THE STRONGEST WINDS ARE NOT EXPECTED TO
COINCIDE WITH THE LOWEST RH VALUES AND FIRE WEATHER HIGHLITES ARE
NOT EXPECTED AT THIS TIME. WIDESPREAD PRECIPITATION IS NOT
EXPECTED WITH THIS FRONTAL PASSAGE OR THE NORTHWEST FLOW BEHIND IT
WITH THE BEST CHANCE OF SHOWERS SUNDAY. ANY SHOWERS THAT DO DEVELOP
THIS WEEKEND WILL BE LIGHT ISOLATED AND SHORT LIVED. TEMPERATURES
WILL COOL DOWN SUNDAY WITH MAXIMUM TEMPERATURES STRUGGLING TO REACH
INTO THE 70S. LOWS MONDAY MORNING WILL BE APPROACHING FREEZING AT
MANY LOCATIONS ACROSS THE AREA...HOWEVER BY MONDAY HIGH TEMPERATURES
WILL BE CLIMBING INTO THE 70S AGAIN AS THE COLD AIR MASS STARTS TO
TRANSITION EASTWARD. SUK
MONDAY NIGHT THROUGH SATURDAY...MODELS ARE IN AGREEMENT IN
FORECASTING A NORTHWEST FLOW ALOFT THROUGH THE PERIOD AS A STRONG
RIDGE ALOFT BECOMES ESTABLISHED FROM THE WEST COAST STATES TO
WESTERN CANADA. ALTHOUGH THERE WILL OCCASIONALLY BE WEAK WEATHER
DISTURBANCES EMBEDDED IN THIS FLOW..NOT ONLY DO NOT SEE ANY THREAT
FOR PRECIPITATION DO NOT EXPECT MUCH IN THE WAY OF CLOUDINESS. HIGH
TEMPERATURES SHOULD BE RELATIVELY STABLE RANGING FROM THE MID 70S TO
LOWER 80S THROUGH THE PERIOD. GUSTY WEST TO NORTHWEST WINDS MIGHT
AFFECT THE PLAINS ON TUESDAY AS A COLD FRONT MOVES THROUGH THE AREA.
BLANK
&&
.FIRE WEATHER...RELATIVE HUMIDITIES WILL ONCE AGAIN DROP INTO THE
TEENS AND SINGLE DIGITS SATURDAY BUT THE WINDS WILL NOT BE AS
STRONG...BREEZY WINDS WILL BE POSSIBLE ALONG THE HILINE.
A COLD FRONT IS EXPECTED TO MOVE THROUGH THE FORECAST AREA TUESDAY.
GUSTY WEST WINDS COULD DEVELOP AHEAD OF THE COLD FRONT THEN BECOME
GUSTY OUT OF THE NORTHWEST BEHIND THE FRONT. THESE WINDS COMBINED
WITH EXPECTED LOW RELATIVE HUMIDITIES COULD CREATE CRITICAL FIRE
WEATHER CONDITIONS. NO SHOWERS OR THUNDERSTORMS ARE EXPECTED WITH
THIS FRONT.
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 80 47 66 39 / 0 10 0 0
CTB 73 42 64 33 / 0 20 10 0
HLN 82 49 71 39 / 0 0 10 0
BZN 83 41 72 32 / 0 10 20 10
WEY 74 30 67 23 / 10 10 20 10
DLN 82 41 71 35 / 10 10 10 10
HVR 82 46 67 35 / 0 20 20 0
LWT 81 44 62 35 / 0 10 10 10
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...EMANUEL/SUK
LONG TERM...BLANK
AVIATION...BLANK
WEATHER.GOV/GREATFALLS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1030 AM EDT SAT SEP 15 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL DRIFT SOUTH TODAY AND DISSIPATE OVER THE AREA
SUNDAY. LOW PRESSURE DEVELOPING ALONG THE GULF COAST MONDAY WILL
MOVE THROUGH THE WESTERN CAROLINAS TUESDAY...BRINGING PERIODS OF
SHOWERS AND THUNDERSTORMS TO THE AREA...WITH LOCALLY HEAVY RAIN
POSSIBLE. A COLD FRONT WILL CROSS THE AREA EARLY WEDNESDAY...WITH
HIGH PRESSURE BUILDING IN BEHIND IT CREATING COOLER AND DRIER
WEATHER FOR THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM SATURDAY...FOG HAS LIFTED ACROSS THE EASTERN CAROLINAS
BUT STUBBORN LOW CLOUDS IN THE SC PEE DEE REGION MAY TAKE ANOTHER 30
MINUTES OR SO TO BURN OFF. MOSTLY SUNNY SKIES LATE THIS MORNING WILL
TURN PARTLY CLOUDY ACROSS MOST OF OUR AREA THIS AFTERNOON AS FAIRLY
STEEP LOW-LEVEL LAPSE RATES AND GOOD MOISTURE CONTENT BELOW 850 MB
HELP PRODUCE A CUMULUS CLOUD FIELD. THE 12Z CHS SOUNDING SHOWED THE
06Z GFS AND NAM MODELS WERE BOTH 5 DEGREES F TOO DRY WITH DEWPOINTS
FROM THE SURFACE UP THROUGH 850 MB. THIS ADDITIONAL MOISTURE SHOULD
HELP ENHANCE THE AFTERNOON CUMULUS.
THE BIGGEST QUESTION MARK WITH TODAY`S FORECAST IS THE POTENTIAL OF
AFTERNOON AND EVENING SHOWERS. THE 06Z GFS AND NAM MODELS PRODUCE
SOME ISOLATED SHOWERS BUT THE ASSOCIATED STATISTICAL OUTPUT SHOWS
ONLY 0-10 PERCENT POPS. THE PAST SEVERAL HRRR RUNS ALSO SHOW DRY
WEATHER THROUGH THIS EVENING. GIVEN FAIRLY MOIST LOW-LEVELS AND
STEEP LAPSE RATES UP THROUGH AN INVERSION AT 10-11 KFT I EXPECT AT
LEAST SOME ISOLATED SHOWERS MUCH LIKE EXPERIENCED YESTERDAY. THE
SEABREEZE BOUNDARY...PARTICULARLY IN SE NORTH CAROLINA WHERE NATURAL
CONVERGENCE IS PRODUCED BY THE SEABREEZE...IS AN OBVIOUSLY TRIGGER.
A SECOND POSSIBLE TRIGGER IS THE ARRIVAL OF A DYING COLD FRONT FROM
THE NORTH LATE THIS AFTERNOON...ALTHOUGH CONVERGENCE IS WEAKENING
WITH THIS FEATURE GIVEN THE INCREASINGLY SIMILAR WIND DIRECTIONS ON
EITHER SIDE. IN ANY CASE WE`LL KEEP POPS NO HIGHER THAN 25% THROUGH
THIS EVENING.
HIGHS TODAY SHOULD REACH THE MID 80S AWAY FROM THE OCEAN...WITH
HIGHS AROUND 80 ON THE BEACHES. MORNING LOW CLOUDS AND FOG SHOULD
HAVE NO IMPACT ON THESE TEMPERATURES.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...SHORT TERM WILL FEATURE A TRANSITIONAL
PERIOD AS SPLIT FLOW 500MB PATTERN TRANSITIONS TO A HIGHLY AMPLIFIED
TROUGH ACROSS THE EASTERN HALF OF THE COUNTRY. HIGH PRESSURE
DRIFTING ACROSS THE MID ATLANTIC SUNDAY WILL ALLOW WINDS TO TURN
GRADUALLY FROM NE TO SE THROUGH THE DAY. THIS OCCURS AT THE SAME
TIME THAT A 60KT 300MB JET MAX MOVES ACROSS NC. EVEN THOUGH FORECAST
SOUNDINGS REMAIN RELATIVELY DRY ABOVE 850MB...THE INCREASING
MOISTURE ON SE FLOW COMBINED WITH THE SUBTLE UPPER SUPPORT COULD
SPAWN AN ISOLATED SHOWER/TSTM DURING THE AFTN...AND WILL KEEP
INHERITED SCHC POP. TEMPS SUNDAY WILL BE RIGHT AROUND CLIMO...LOW TO
MID 80S MOST LOCATIONS. MINS WILL FALL TO RIGHT AROUND CLIMO SUNDAY
NIGHT...MID 60S.
SOUTHERN STREAM VORT MAX WILL GET STRUNG OUT AND LIFT NORTHEAST AS A
DEEP 500MB TROUGH DIGS ACROSS THE CENTRAL PLAINS. WAVE OF LOW
PRESSURE DEVELOPS BENEATH THIS UPPER VORT AND SLIDES NORTHEAST
TOWARDS THE AREA...PUSHING A WARM FRONT ACROSS THE CAROLINAS DURING
MONDAY. AS THIS OCCURS...FLOW WITHIN THE COLUMN TURNS TO BECOME DEEP
SOUTHEASTERLY...ADVECTING SIGNIFICANTLY INCREASED MOISTURE INTO THE
CAROLINAS. ALTHOUGH BEST RAIN CHANCES WILL HOLD OFF UNTIL MONDAY
NIGHT...WILL SHOW INCREASING POP THROUGH THE DAY FROM SOUTH TO
NORTH. WITH PWATS RISING TO NEARLY TWO INCHES MONDAY NIGHT...AND
FORCING INCREASING LATE...EXPECT A PERIOD OF MDT/HEAVY RAINFALL
DEVELOPING AT THE END OF THE PERIOD...AND WILL BUMP ALL LOCATIONS TO
LIKELY POP. TEMPS WILL BE TEMPERED BY CLOUDS/RAIN...REMAINING IN THE
LOW 80S. INCREASED SOUTHERLY FLOW AND RAIN WILL KEEP MINS WELL ABOVE
CLIMO...ONLY FALLING TO AROUND 70.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3 AM SATURDAY...A VERY WET TUESDAY EXPECTED BEFORE DRIER AND
COOLER WEATHER DEVELOPS FOR THE LATTER HALF OF THE UPCOMING WEEK.
INGREDIENTS APPEAR TO BE COMING TOGETHER TO SUPPORT A VERY WET
TUESDAY WITH MODERATE/HEAVY RAINFALL LIKELY ACROSS THE ENTIRE CWA.
SOUTHERN STREAM VORT MAX BEGINS TO PHASE WITH NORTHERN STREAM ENERGY
JUST WEST OF THE CWA. AS THIS OCCURS...SURFACE LOW WORKS UP ALONG
THE APPALACHIANS ACROSS THE WESTERN CAROLINAS. THE KEEPS THE CWA IN
DEEP SOUTHERLY FLOW WHICH ADVECTS A STRONG THETA-E RIDGE INTO THE
AREA. PWATS RISE TO NEARLY 2.25 INCHES...OR 2-3 SD`S ABOVE NORMAL
FOR MID-SEPTEMBER. AT THE SAME TIME...WE ENTER THE RIGHT DIFFLUENT
PORTION OF AN 80-90KT 300MB JET AND 850MB TRANSPORT WINDS APPROACH
40-50 KTS. THIS ALL POINTS TOWARDS PERIODS OF HEAVY RAINFALL...AND
HPC IS PAINTING 1-1.5" OF QPF ACROSS THIS AREA. WITH SUCH STRONG LOW
LEVEL WINDS IN PLACE...COULD BE CONCERNED ABOUT A SEVERE WIND
POTENTIAL...HOWEVER...LACK OF INSOLATION KEEPS ML LAPSE RATES BELOW
6C/KM...SO HEAVY RAIN EXPECTED TO BE THE PRIMARY THREAT. RAIN WILL
CONTINUE THROUGH TUESDAY NIGHT BEFORE LOW MOVES OFF TO THE NORTHEAST
AND ITS ASSOCIATED COLD FRONT DRAGS THROUGH BY EARLY WEDNESDAY.
BEHIND THIS FRONT...COOLER AND DRIER WEATHER EXPECTED THROUGH THE
REST OF THE EXTENDED. HIGH PRESSURE BUILDS DOWN THE COAST AS 500MB
TROUGH RELOADS ACROSS THE MIDWEST. THIS WILL BRING COOL E/NE LOW
LEVEL FLOW...BUT ALSO MOSTLY SUNNY AND DRY CONDITIONS TO FINISH THE
WEEK.
TEMPS TUESDAY WILL BE AROUND CLIMO WITH CLOUDS AND RAIN...FALLING TO
BELOW CLIMO FOR THE REST OF THE WEEK BEHIND THE COLD FRONT. MINS
TUESDAY NIGHT WILL BE ABOVE CLIMO...BEFORE FALLING TO NEAR NORMAL
WED-FRI.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 12Z...FAIRLY WIDESPREAD FOG/STRATUS OVER THE REGION THAT
SHOULD MIX OUT BY 13Z OR SHORTLY THEREAFTER. WASHED OUT COLD FRONT
DROPPING THROUGH THE REGION WILL NOT PROVIDE MUCH IN THE WAY OF
LIFT. LITTLE TO NO CONVECTION IS EXPECTED...PERHAPS ISOLATED ALONG
THE RESULTANT. REINFORCING HIGH PRESSURE WILL GIVE US LIGHT
NORTHEAST FLOW...BECOMING SOUTHEAST ALONG THE COAST.
TONIGHT...INCREASING MOISTURE AS THE BOUNDARY UNDERGOES
FRONTOGENESIS AND RIDES BACK TO THE NORTH AS A WARM FRONT. WILL LOOK
CLOSER AT THE POTENTIAL FOR FOG SUNDAY MORNING IN THE NEXT SET OF
TAFS.
THE EXTENDED OUTLOOK THROUGH WEDNESDAY...LOW CONFIDENCE IFR IN
PRE-DAWN BR SUN-TUE. ISOLATED SHRA/TSRA SUN BECOMING SCATTERED ON
MON...NUMEROUS TUE. VFR DEVELOPING WED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM SATURDAY...A SURFACE COLD FRONT OVER NORTHERN NORTH
CAROLINA WILL MOVE SOUTH TO CAPE FEAR LATE THIS AFTERNOON. WINDS ON
BOTH SIDES OF THE BOUNDARY ARE NORTHERLY SO THE FEATURE IS
CERTAINLY LOSING ITS DEFINITION AS IT MOVES SOUTH. UNLESS THERE IS
A LINE OF CLOUDS OR SHOWERS ACCOMPANYING THE FRONT...THE ONLY IMPACT
MARINERS SHOULD NOTE AS THE FRONT REACHES US IS A VEERING OF THE
WIND DIRECTION A LITTLE MORE EASTERLY. OTHERWISE NORTH-NORTHEASTERLY
WINDS AROUND 10 KT WILL CONTINUE THROUGH THE DAY...TURNING EAST TO
EVEN SOUTHEAST ALONG THE IMMEDIATE COAST AS A WEAK SEABREEZE
DEVELOPS. SEA HEIGHTS AT THE BUOYS ARE 3-4 FT LIKE YESTERDAY...BUT
SPECTRAL WAVE DATA LOOKS VERY DIFFERENT THAN YESTERDAY WITH VERY
LITTLE SHORT PERIOD WAVE ENERGY PRESENT. THE DOMINANT PERIOD IS NOW
9-10 SECONDS IN AN EASTERLY SWELL THAT SHOULD PERSIST THROUGH
TONIGHT.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...HIGH PRESSURE DRIFTING ACROSS THE
MID-ATLANTIC STATES WILL KEEP WINDS LIGHT SUNDAY...AS THEY VEER
SLOWLY FROM THE NE EARLY...TO SE BY NIGHT. SEAS SUNDAY WILL FALL
SLOWLY THROUGH THE DAY...FROM 3-4 FT EARLY TO 2-4 FT LATE...FORMED
BY A COMBINATION OF AN EASTERLY WIND WAVE AND A 2-3 FT/12SEC SE
SWELL FROM HURRICANE NADINE. CONDITIONS ACROSS THE WATERS WILL
DETERIORATE MONDAY AS A STORM SYSTEM PASSES WEST OF THE AREA. A
WARM FRONT WILL CROSS THE WATERS DURING MONDAY...TURNING WINDS TO
THE SOUTH...WHICH WILL THEN INCREASE DRAMATICALLY MONDAY NIGHT.
WINDS LESS THAN 10 KTS EARLY MONDAY WILL RISE UP TO 15-20 KTS
MONDAY NIGHT. ALTHOUGH THE LONG PERIOD SWELL WILL DECAY AS
HURRICANE NADINE PULLS AWAY...THIS INCREASING WIND WILL FORCE
STEEPER WAVES...AND SEAS WILL BUILD TO 3-5 FT BY THE END OF THE
PERIOD...WITH ISOLATED 6 FTERS POSSIBLE. AT THIS TIME IT APPEARS A
SCEC WILL BE NEEDED MONDAY NIGHT...WITH AN SCA POSSIBLE.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3 AM SATURDAY...STRONG SOUTHERLY WINDS TUESDAY CREATE
HAZARDOUS CONDITIONS ACROSS THE COASTAL WATERS...WITH A SMALL CRAFT
ADVISORY LIKELY NEEDED MUCH OF THE DAY. SOUTHERLY WINDS AHEAD OF A
COLD FRONT WILL BE 15-20 KTS...POSSIBLY HIGHER...AND HELP BUILD SEAS
TO 4-6 FT. THESE WAVES WILL BE QUITE STEEP AS WELL...WITH A DOMINANT
PERIOD OF 5-6 SECONDS. VERY LATE TUESDAY NIGHT THE COLD FRONT WILL
CROSS THE WATERS...TURNING WINDS TO THE NW...THEN NE ON WEDNESDAY
WHILE SPEEDS DECREASE TO 10-15 KTS. SEAS FALL QUICKLY...BECOMING 2-3
FT THROUGH MUCH OF WEDNESDAY...ALTHOUGH A CONFUSED SEA STATE IS
LIKELY EARLY WEDNESDAY DUE TO SEVERAL DIFFERENT WAVE GROUPS PRESENT
IN THE SPECTRUM.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...TRA
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...43
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
932 AM EDT SAT SEP 15 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL MOVE SOUTH OF THE REGION TODAY. HIGH
PRESSURE WILL BUILD OVER THE AREA TONIGHT INTO SUNDAY THEN MOVE
OFFSHORE SUNDAY NIGHT. LOW PRESSURE WILL MOVE NORTH FROM THE GULF
COAST REGION MONDAY AND ACROSS WESTERN NORTH CAROLINA MONDAY
NIGHT. A COLD FRONT WILL MOVE ACROSS THE REGION TUESDAY NIGHT
FOLLOWED BY HIGH PRESSURE BUILDING IN FROM THE NORTHWEST LATE
WEDNESDAY INTO FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 930 AM SATURDAY...LATEST RUNS OF BOTH THE RAP AND NAM12 SHOW
NO PRECIPITATION ACROSS THE CWA FOR THE REMAINDER OF THE DAY AND
HAVE UPDATED TO DROP ANY MENTION OF POPS. COLD FRONT IS NOW SOUTH
OF THE CWA WITH DECENT SUBSIDENCE KICKING IN. EXPECT SUNSHINE TO
ALLOW MAX TEMPERATURES TO REACH FORECAST VALUES IN THE LOWER 80S
OVER MOST LOCATIONS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
AS OF 215 AM SATURDAY...HIGH PRES WILL BUILD IN FROM THE N WITH
DRY WX EXPECTED. AS WINDS GO LIGHT INLAND WILL AGAIN HAVE THE
THREAT FOR SOME PATCHY FOG LATE. LOWS WILL RANGE FROM THE UPR 50S
COOLER INLAND SPOTS TO MID/UPR 60S BEACHES.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 315 AM SAT...MODELS ARE ALL IN GENERAL GOOD AGREEMENT
THROUGH THE PERIOD UNTIL MID WEEK WHEN THERE ARE MINOR TIMING
DIFFERENCES WITH THE COLD FRONT PUSHING OFF THE COAST ON WED.
GENERALLY FOLLOWED A BLEND OF MODEL GUIDANCE FOR MAJOR FEATURES.
FOLLOWED CLOSE TO MOS BIAS CORRECTED GUIDANCE FOR TEMPS THROUGH
THE PERIOD...WHICH WILL BE PRETTY CLOSE TO CLIMATOLOGY VALUES. MAD
ONLY MINOT POP ADJUSTMENTS THROUGH THE PERIOD. GENERALLY JUST A
SLIGHT CHANCE OF A SHOWER THROUGH SUNDAY INTO SUNDAY NIGHT...WITH
A GRADUAL INCREASE IN POPS ON MONDAY. THE BEST CHANCE OF SHOWERS
AND THUNDERSTORMS WILL COME ON TUESDAY AHEAD OF THE APPROACHING
COLD FRONT. COULD SEE SOME STRONG THUNDERSTORMS BUT CONFIDENCE IN
TIMING AND INSTABILITY IS TOO LOW AT THIS POINT TO GIVE E
DEFINITIVE CHANCE OF SEVERE STORMS. THE ECMWF DRIES THINGS OUT
DEFINITIVELY ON WEDNESDAY...BUT GFS IS A BIT SLOWER TO CLEAR
THINGS OUT COMPLETELY ALONG THE COAST...THEREFORE CONTINUED TO
CARRY SLIGHT CHANCE POPS THROUGH THE DAY WEDNESDAY BEFORE DRYING
THINGS OUT THURSDAY AND FRIDAY.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM /THROUGH TONIGHT/...
AS OF 615 AM SATURDAY...WIDESPREAD LIFR IN FOG/ST EARLY THIS
MORN. CONDITIONS SHLD BEGIN TO IMPROVE AROUND 12Z AS WEAK COLD
FRONT DROPS INTO REGION AND MIXING STARTS. ONCE FOG LIFTS EXPECT
VFR REST OF THE DAY WITH POSS SOME ISOLD SHRA NEAR CST LATE. AS
HIGH PRES BUILDS IN FROM THE N TONIGHT WILL AGAIN HAVE THE THREAT
FOR SOME PATCHY FOG AND IFR CONDITIONS AT TIMES MAINLY AFT 08Z.
LONG TERM /SUNDAY THROUGH WED/...
AS OF 315 AM SAT...VFR CONDITIONS PREVAIL THROUGH SUNDAY INTO
SUNDAY NIGHT ALTHOUGH CAN`T RULE OUT A STRAY SHOWER SUNDAY NIGHT.
THE CHANCE FOR SCATTERED SHOWERS WILL INCREASE INTO MONDAY AND
MONDAY NIGHT...BUT WOULD EXPECT MOSTLY MVFR CONDITIONS. BY TUESDAY
MORE WIDESPREAD SHOWERS AND TSTMS WILL MOVE INTO THE AREA AHEAD OF
A COLD FRONT. MVFR CONDITIONS WILL BE PREDOMINATE WITH PERIODS OF
IFR POSSIBLE OCCASIONALLY. CONDITIONS SHOULD BEGIN TO IMPROVE
BEHIND THE FRONT ON WEDNESDAY.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 930 AM SATURDAY...GENERALLY NW/NNW WINDS OF 10 TO 15 KNOTS
ARE EXPECTED THROUGH THIS AFTERNOON WITH SEAS OF 2 TO 4 FEET
BUILDING TO 3 TO 5 FEET LATE. OF INTEREST WILL BE DEVELOPMENT OF
LONG PERIOD SWELLS BY THIS EVENING. CURRENT OBSERVATIONS SHOWING
ABOUT 8 SECOND PERIODS...BUT THESE ARE FORECAST TO INCREASE TO 15
SECONDS OR GREATER BY EVENING. THIS WILL LEAD TO ROUGH SURF AND AN
INCREASED THREAT OF RIP CURRENTS. N TO NE WINDS WILL CONT AT
MAINLY 10 TO 15 KTS TONIGHT AS HIGH PRES BUILDS IN FROM THE
N...COULD BE SOME GUSTS TO 20 KT EARLY ESPCLY CNTRL AND NRN WTRS.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 315 AM SAT...AS MENTIONED IN LONG TERM DISCUSSION NO
SIGNIFICANT MODEL DIFFERENCES THROUGH THE PERIOD. THERE IS JUST A
MINOR TIMING DIFFERENCE WITH THE COLD FRONT MOVING THROUGH THE
REGION WEDNESDAY. FOLLOWED A BLEND OF GFS/ECMWF FOR WINDS IN THAT
TIME PERIOD. EARLY IN THE PERIOD SCA CONDITIONS DUE MAINLY TO THE
LONG PERIOD SWELL WILL BEGIN TO DIMINISH. SEAS WILL FALL BELOW SCA
CONDITIONS ALL WATERS BY LATE SUNDAY AFTERNOON. THE LULL IN CALM
CONDITIONS WILL BE SHORT ON MONDAY AS WINDS BECOME SOUTHERLY INCREASE
TO 20 TO 25 KT AHEAD OF THE APPROACHING COLD FRONT ON
TUESDAY...WITH SEAS BUILDING TO 6 TO 7 FEET ACROSS A LARGE PORTION
OF THE WATERS. THE COLD FRONT SHOULD PASS THROUGH THE WATERS
WEDNESDAY WITH SEAS SUBSIDING.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...BEACH HAZARDS STATEMENT UNTIL 8 PM EDT THIS EVENING FOR NCZ103.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 6 PM EDT
SUNDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 1 PM EDT
SUNDAY FOR AMZ150-156-158.
&&
$$
SYNOPSIS...RF
NEAR TERM...CTC
SHORT TERM...RF
LONG TERM...RSB
AVIATION...RSB/RF
MARINE...RSB/CTC/RF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
715 AM EDT SAT SEP 15 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL DROP SOUTHWARD THROUGH NORTH CAROLINA
TODAY... THEN STALL NEAR THE SOUTH CAROLINA BORDER THROUGH SUNDAY...
BEFORE DRIFTING BACK NORTHWARD AS A WARM FRONT SUNDAY NIGHT. A
STRONG STORM SYSTEM WILL APPROACH THE AREA FROM THE SOUTHWEST MONDAY
THROUGH TUESDAY.
&&
.NEAR TERM /TODAY THROUGH SUNDAY NIGHT/...
AS OF 215 AM SATURDAY...
FOR TODAY/TONIGHT: EXPECT A FAIRLY QUIET AND SUMMER-LIKE DAY
OVERALL... BUT WITH AN INCREASE IN CLOUDS LATE. THE LATEST SURFACE
ANALYSIS SHOWS THE VERY WEAK SURFACE RIDGE CONTINUING TO LOSE ITS
GRIP ON THE AREA AHEAD OF AN INCOMING COOL FRONT... STRETCHING FROM
NEW ENGLAND ACROSS SE WV TO THE MO/AR BORDER. AS ANTICIPATED...
SURFACE DEW POINTS HAVE REBOUNDED FROM 24 HOURS AGO TO AROUND 60
WEST AND MID-UPPER 60S EAST. WITH LIGHT WINDS AND ONLY PATCHES OF
HIGH CLOUDS EARLY THIS MORNING... FOG FORMATION IS FAVORED
ESPECIALLY IN LOW-LYING AREAS AND NEAR BODIES OF WATER OVER THE
EASTERN CWA. INDEED... THE HRRR MODEL DEPICTS DENSE FOG FROM RDU
NORTH AND EAST AS WELL AS IN THE FAR SRN CWA IN THE PREDAWN HOURS.
OTHERWISE... THE DEPARTURE OF THE WEAK UPPER LEVEL WAVE IS NOW
PUSHING YESTERDAY`S COPIOUS MID/HIGH CLOUDINESS OFF THE NC COAST.
ANY DAYBREAK FOG/STRATUS IN THE EASTERN CWA SHOULD LIFT AND MIX OUT
BY MID MORNING... AND FORECAST SOUNDINGS UNIFORMLY SUPPORT
DEVELOPMENT OF SCATTERED FLAT DAYTIME CUMULUS BY THIS AFTERNOON.
WE`LL ALSO SEE THICKENING MID/HIGH CLOUDS BY LATE IN THE DAY AS THE
CLOUD SHIELD FROM THE OH VALLEY BACK OVER THE MID MISS VALLEY SLIDES
EASTWARD. THE SURFACE FRONT IS EXPECTED TO MAKE A SLOW SOUTHWARD
DRIFT THROUGH CENTRAL NC TODAY. A PRECEDING WEAK TROUGH WILL SWING
SURFACE WINDS AROUND TO NORTHERLY AND NORTHEASTERLY THIS MORNING...
BEFORE THE FRONTAL ZONE ITSELF DROPS SOUTHWARD LATER THIS
AFTERNOON... REACHING THE SC BORDER AREA BY EARLY-MID EVENING. THE
DELAY IN THE ARRIVAL OF COOLER LOW LEVEL THICKNESSES (ESPECIALLY IN
SRN NC WHERE THICKNESSES WILL PEAK NEAR 1410 METERS) AND LIMITED
CLOUD COVER THROUGH THE FIRST HALF OF THE DAY WILL ALLOW TEMPS TO
TOP OUT NEAR 80 TO 85... A COUPLE OF DEGREES ABOVE NORMAL. REGARDING
PRECIP CHANCES... DAYTIME HEATING WITH HIGHER SURFACE DEW POINTS AND
WEAK MASS CONVERGENCE ALONG THE PREFRONTAL TROUGH MAY INSTIGATE A
FEW SHALLOW LATE-AFTERNOON SHOWERS IN THE SOUTHEAST CWA... A
SCENARIO SUPPORTED BY THE CONVECTION-ALLOWING WRF-NMM. IN GENERAL
HOWEVER... THE MID LEVELS ARE LIKELY TO REMAIN TOO DRY AND STABLE
FOR ANY CONVECTIVE PRECIP TODAY... AND DYNAMIC FORCING FOR ASCENT IS
ABSENT AS WELL. BUT THE VORTICITY MAXIMUM CURRENTLY NOTED IN WATER
VAPOR IMAGERY OVER TN IS EXPECTED TO EASE EASTWARD THROUGH TODAY...
SHEARING ACROSS THE NC MTNS INTO THE SRN FOOTHILLS AND SRN PIEDMONT
STARTING THIS EVENING. ACCOMPANYING THIS WILL BE AN INCREASE IN
MOIST UPGLIDE AROUND 300K OVER WRN NC... AS THE 850 MB ANTICYCLONE
JUST TO OUR WEST THIS MORNING SHIFTS ESE RESULTING IN RETURN FLOW
INTO THE WRN CAROLINAS. SO ALONG WITH THE THICKER MID/HIGH CLOUDS
SPREADING IN FROM THE WEST THIS EVENING AND TONIGHT... LOWER LEVEL
MOISTURE WILL INCREASE AS WELL ESPECIALLY IN AREAS WEST OF HIGHWAY
1. WILL BRING IN A CHANCE OF SHOWERS AND STORMS INTO THE WRN AND SW
CWA OVERNIGHT. LOWS 57-64 WITH CLOUDS AND THE STALLED FRONT KEEPING
TEMPS UP IN THE SOUTHERN CWA.
FOR SUNDAY/SUNDAY NIGHT: A DEEP POSITIVELY-TILTED MID LEVEL TROUGH
WHICH NOW STRETCHES FROM SRN NM ACROSS THE TX PANHANDLE INTO ERN KS
WILL SHIFT EASTWARD ACROSS TX SUNDAY/SUNDAY NIGHT... WHILE WEAK
VORTICITY SHEARS EASTWARD IN FAST WEST-EAST FLOW AHEAD OF THE TROUGH
INTO NC. AT THE SURFACE... THE FRONTAL ZONE WILL REMAIN STALLED NEAR
THE NC/SC STATE LINE THROUGH SUNDAY... BUT AS THE HIGH PRESSURE AREA
CENTERED TO OUR NORTH OVER SWRN PA PUSHES EASTWARD ACROSS THE MID
ATLANTIC REGION... THE LOW LEVEL FLOW WILL STEADILY VEER FROM
NORTHEASTERLY TO EASTERLY THEN FINALLY TO SOUTHEASTERLY... WITH THE
FRONTAL ZONE KICKING BACK NORTHWARD THROUGH THE SRN PIEDMONT/WRN
SANDHILLS. IN ADDITION TO THE IMPROVING MID LEVEL LIFT OVER NC...
UPPER DIVERGENCE WILL STEADILY INCREASE AS FLOW ALOFT SPEEDS UP TO
OUR NORTH AND NW. AND THE DEEPENING LOW LEVEL RETURN FLOW WILL
GENERATE IMPROVING MOIST UPGLIDE PARTICULARLY OVER WRN AND NRN NC...
ALONG THE NORTHEAST-DRIFTING AND WEAKENING SURFACE FRONTAL ZONE.
MOISTURE WILL CONTINUE TO DEEPEN WITH PRECIP WATER VALUES INCREASING
TO 150-200% OF NORMAL SUNDAY THROUGH SUNDAY NIGHT. EXPECT THE CHANCE
FOR SHOWERS AND A FEW STORMS TO INCREASE AND SPREAD FROM THE FAR WRN
CWA EARLY ACROSS THE REST OF THE WRN CWA THROUGH SUNDAY... THEN WE
SHOULD SEE SCATTERED SHOWERS AND STORMS AREAWIDE (YET STILL FOCUSED
ON THE WEST/NORTH WHERE MOISTURE TRANSPORT WILL BE HIGHEST) SUNDAY
EVENING AND NIGHT AS THE MOIST UPGLIDE AND UPPER LEVEL FORCING
COMPENSATES FOR THE LOSS OF DAYTIME HEATING AND INSTABILITY.
THICKNESSES STAY NEAR SEASONAL NORMALS BUT WITH CLOUDS OVERSPREADING
THE AREA... EXPECT HIGHS TO BE A BIT UNDER NORMAL... IN THE UPPER
70S TO LOWER 80S. LOWS 61-65. -GIH
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 240 AM SATURDAY...
MONDAY...
AN UPPER LOW CURRENTLY OVER SOUTHERN NEW MEXICO WILL OPEN UP AND
DRIFT SLOWLY ACROSS THE SOUTHERN US THIS WEEKEND...AND EVENTUALLY
LIFT NORTHEAST TOWARD THE APPALACHIANS LATE MONDAY WHILE A NORTHERN
STREAM SHORTWAVE AMPLIFIES OUT OF CANADA INTO THE MID WEST.
WARM...MOIST ADVECTION WILL RAMP UP MONDAY AS A DEEP SOUTHWESTERLY
FLOW DEVELOPS AHEAD OF THE SOUTHERN STREAM WAVE...TAPPING THE GULF
OF MEXICO WHERE PW VALUES ARE WELL OVER 2 INCHES. HOWEVER...THE
STRENGTHENING LOW LEVEL JET AND BEST UPPER DIVERGENCE ASSOCIATED
WITH AN INTENSIFYING UPPER JET OVER THE GREAT LAKES WILL STILL BE
WEST OF THE MOUNTAINS DURING THE DAY...AND ONLY ISOLATED TO
SCATTERED WARM ADVECTION SHOWERS/STORMS ARE EXPECTED OVER CENTRAL
NC. DEEP LAYER SHEAR WILL BE INCREASING DURING THE DAY AS THE
HEIGHTS ALOFT BEGIN TO FALL OVER THE OHIO VALLEY AHEAD OF THE
NORTHERN STREAM WAVE. HOWEVER... INSTABILITY MAY BE HAMPERED BY
WIDESPREAD CLOUD COVER AND RELATIVELY WARM...MOIST MID LEVELS. WHILE
A FEW STRONG STORMS WILL BE POSSIBLE... THE MAIN SEVERE THREAT
SHOULD INSTEAD COME LATER MONDAY NIGHT INTO TUESDAY AS BETTER
SYNOPTIC FORCING ARRIVES. HIGHS MONDAY ARE FORECAST TO RANGE FROM
THE MID 70S NORTHWEST TO LOWER 80S SOUTHEAST.
MONDAY NIGHT THROUGH TUESDAY NIGHT...
THE AFOREMENTIONED SOUTHERN STREAM WAVE IS FORECAST TO WEAKEN AND
LIFT NORTHEAST FROM THE GULF COAST AND ALONG THE APPALACHIANS MONDAY
NIGHT AND TUESDAY. STRENGTHENING UPPER LEVEL DIVERGENCE...ALONG
WITH A 35-45 KT LOW LEVEL JET AND STRONG LOW LEVEL VEERING WILL
BRING A A PERIOD OF WIDESPREAD SHOWERS/STORMS TO THE AREA DURING
THIS PERIOD. HOWEVER...MODELS HAVE DIVERGED A BIT IN THE LAST FEW
RUNS REGARDING THE TIMING OF BEST FORCING...WITH THE GFS NOW
SLIGHTLY FASTER THAN THE ECMWF/NAM. PRECIP WILL CONTINUE TO BE
FOCUSED ALONG THE MOUNTAINS AND FOOTHILLS MONDAY EVENING AND
INITIALLY THERE MAY BE A STRONG GRADIENT BETWEEN WIDESPREAD SHOWERS
OVER THE WESTERN PIEDMONT AND LITTLE TO NO ACTIVITY TO THE EAST.
HOWEVER...AS THE REMNANTS OF THE SOUTHERN STREAM SHORTWAVE
ARRIVES...PRECIP WILL SPREAD EAST ACROSS THE CWA...BETWEEN 06Z AND
18Z TUESDAY BASED ON CURRENT MODEL PROJECTIONS. WHILE MODELS HAVE
GRADUALLY BACKED OFF ON SHOWING A SURFACE LOW EAST OF THE
MOUNTAINS...THERE WILL STILL BE A WINDOW WHERE BACKED SURFACE
WINDS...STRONG LOW LEVEL SHEAR AND LOW LCLS MAY SUPPORT A TORNADO
THREAT. HOWEVER...INSTABILITY AND POTENTIAL UPDRAFT STRENGTH ARE
QUESTIONABLE DUE TO THE LESS FAVORABLE OVERNIGHT
TIMING...PARTICULARLY IN THE GFS SOLUTION. AS SUCH... QUITE A BIT OF
UNCERTAINTY REMAINS REGARDING THE SEVERE/TORNADO THREAT. HEAVY RAIN
LOOKS TO ALMOST CERTAINLY BE AN ISSUE...ESPECIALLY OVER THE WESTERN
PIEDMONT...WITH A PROLONGED FETCH OF GULF MOISTURE AND PERSISTENT
ISENTROPIC/UPSLOPE AIDED ACCENT MONDAY NIGHT. LOWS SHOULD BE MUGGY
IN THE MID TO UPPER 60S.
AS THE COLD FRONT APPROACHES FROM THE MID WEST ON TUESDAY...MODELS
ARE SHOWING A BIT MORE OF A NEGATIVE TILT TO THE MAIN TROUGH AXIS AS
IT SWINGS ACROSS THE OH/TN VALLEY REGIONS. THUS...SHOWERS AND
STORMS SHOULD BEGIN TO SHIFT EAST ACROSS THE CWA MORE RAPIDLY BY
TUESDAY AFTERNOON AND EVENING...MOVING EAST OF THE COASTAL PLAIN BY
TUESDAY NIGHT. THE COLD FRONT MAY LAG A BIT...BUT SHOULD ALSO CLEAR
THE AREA BY WEDNESDAY MORNING...WITH HIGH PRESSURE BUILDING ACROSS
THE CENTRAL APPALACHIANS. QUIET WEATHER IS THEN EXPECTED THROUGH
THE END OF THE WEEK...WITH THE POTENTIAL FOR ANOTHER NORTHERN STREAM
WAVE APPROACHING FROM THE MIDWEST NEXT WEEKEND.
REGARDING POPS AND TEMPS....
WILL NOT MAKE ANY SIGNIFICANT CHANGES TO THE LIKELY/CATEGORICAL POPS
MONDAY NIGHT AND TUESDAY...AND WILL HAVE POPS COMING TO AN END IN
THE EAST PRIOR TO 12Z WEDNESDAY. HIGHS TUESDAY WILL BE TRICKY DUE
TO THE PRECIP COVERAGE BUT SHOULD BE MOSTLY IN THE 70S...EXCEPT FOR
THE FAR SOUTHEAST WHERE 80 MAY BE POSSIBLE.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 240 AM SATURDAY...
DRIER AND MORE STABLE AIR IS FORECAST TO FILTER ACROSS THE AREA
WEDNESDAY AND THURSDAY AS THE EARLY WEEK STORM SYSTEM DEPARTS THE
REGION AND HIGH PRESSURE BUILDS ACROSS THE LOWER MIDWEST. THIS WILL
LEAD TO A RELATIVE MIN IN HIGH TEMPS...AS MUCH AS 4-8 DEGREES BELOW
NORMAL BASED ON POST-FRONTAL THICKNESSES SOME 15-20M BELOW NORMAL.
MODELS THEN SHOW ANOTHER NORTHERN STREAM WAVE DIVING OUT OF CANADA
AND STRENGTHENING THE LONG WAVE TROUGH OVER THE EASTERN HALF OF THE
US....WITH ANOTHER COLD FRONT POSSIBLY APPROACHING THE CAROLINAS BY
NEXT WEEKEND.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 715 AM SATURDAY...
THE MAIN AVIATION CONCERN THIS MORNING IS AREAS OF FOG. SCT BANKS OF
IFR/LIFR FOG WILL PERSIST NEAR KRWI/KFAY THROUGH 13Z-14Z WITH
ISOLATED BANKS NEAR KRDU. LOWER NEAR-GROUND HUMIDITY AT KINT/KGSO
WILL LIMIT ANY FOG DEVELOPMENT AT THESE SITES.
ANY ADVERSE AVIATION CONDITIONS AT KRDU/KFAY WILL LIFT/MIX OUT BY
14Z. SIMILARLY... THE IFR/LIFR VSBY/CIG AT KRWI WILL SLOWLY IMPROVE
TO VFR THROUGH 15Z. AFTER THIS TIME... DAYTIME CUMULUS CLOUDS THIS
AFTERNOON AT ALL CENTRAL NC FORECAST SITES WILL BE BASED ABOVE 4
THOUSAND FT AGL. A WEAK FRONT WILL SINK SOUTHWARD THROUGH NC DURING
TODAY. WINDS OVER CENTRAL NC WILL BE LIGHT (UNDER 8 KTS OVERALL)
FROM THE NORTH THEN NORTHEAST THIS MORNING... EVENTUALLY SHIFTING TO
BE FROM THE EAST THEN ESE LATER TODAY AS HIGH PRESSURE TO OUR NORTH
BUILDS IN BRIEFLY BEHIND THE FRONT. ONLY ISOLATED SHOWERS ARE
EXPECTED THROUGH NIGHTFALL... HOWEVER CLOUDS BASED ABOVE 4 THOUSAND
FEET WILL STEADILY INCREASE IN NUMBER AND THICKEN BY EARLY
EVENING... RESULTING IN BROKEN TO OVERCAST VFR SKIES AT
KINT/KGSO/KRDU TOWARD 06Z WHILE SKIES REMAIN FAIR AT KRWI/KFAY. NO
SIGNIFICANT FOG IS EXPECTED THROUGH 12Z SUNDAY MORNING.
LOOKING BEYOND 12Z SUNDAY MORNING... CIGS WILL LOWER TOWARD SUNDAY
MORNING BUT WILL MOSTLY REMAIN VFR... AS WILL VSBYS WITH LITTLE TO
NO FOG EXPECTED TO DEVELOP. A MID-UPPER TROUGH OVER NM/TX THIS
MORNING WILL MOVE SLOWLY EASTWARD SUNDAY THROUGH MONDAY AS A
STRENGTHENING FRONT APPROACHES FROM THE WEST... AND AVIATION
CONDITIONS WILL SLOWLY DETERIORATE IN THIS TIME FRAME... STARTING
FIRST AT KINT/KGSO SUNDAY NIGHT WITH MVFR CIGS/VSBYS IN
SHOWERS/STORMS. MVFR TO IFR CONDITIONS ARE LIKELY ALL ACROSS CENTRAL
NC LATE MONDAY WELL INTO TUESDAY WITH STRONG VEERING WINDS THROUGH
THE LOWEST 10 THOUSAND FT. IMPROVING CONDITIONS ARE EXPECTED
WEDNESDAY WITH A COOLER INCOMING AIR MASS BEHIND THE FRONT. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...SMITH
LONG TERM...SMITH
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1044 AM EDT SAT SEP 15 2012
.SYNOPSIS...
WEAK SURFACE HIGH PRESSURE WILL REMAIN IN PLACE OVER THE REGION
TODAY THROUGH SUNDAY. STRONG LOW PRESSURE SYSTEM OFF THE GULF COAST
WILL TRACK NORTHEAST ACROSS EASTERN TENNESSEE BEFORE A COLD FRONT
MOVES IN FROM THE WEST TUESDAY NIGHT. DRY HIGH PRESSURE WILL BUILD
IN FORM THE NORTH ON WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1030 AM EDT UPDATE...TRYING TO PINPOINT TIMING OF DIURNAL
CONVECTION. SATELLITE IMAGERY SHOWING CU ALREADY POPPING UP ON THE
HIGHEST RIDGETOPS. NAM AND RAP PROG SOUNDINGS SUPPORT PLENTY OF CU
BUT A WARM LAYER AROUND 600MB LIMITS THE INSTABILITY THROUGH MUCH OF
THE AFTERNOON...FINALLY COOLING A BIT AFTER ABOUT 20Z WHEN CAPE
INCREASES TO VALUES MORE IN LINE WITH MEASURABLE PRECIP. WILL DELAY
ONSET OF POPS A BIT BUT OTHERWISE...TODAY/S FORECAST LOOKS GOOD.
AT 230 AM EDT SATURDAY...A FLAT UPPER RIDGE WILL REMAIN OVER THE
SOUTHEAST TODAY AND TONIGHT....WHILE AN UPPER TROUGH CROSSES THE
NORTHEAST...AND A SOUTHERN STREAM TROUGH CROSSES TX. A COLD FRONT
WILL CROSS OUR AREA TODAY...STALLING IN A WEST TO EAST ORIENTATION
TO OUR SOUTH TONIGHT. MOISTURE ASSOCIATED WITH THE FRONT IS EXPECTED
TO SUPPORT CONVECTIVE DEVELOPMENT IN THE MOUNTAINS TODAY WITH MODEST
INSTABILITY. BY TONIGHT...ISENTROPIC UPGLIDE SETS UP OVER THE
BOUNDARY...SUPPORTING A SMALL CHANCE OF MORE WIDESPREAD
PRECIPITATION ACROSS THE AREA. TEMPERATURES WILL BE NEAR NORMAL.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
AS OF 330 AM SATURDAY...AS PREVIOUSLY MENTIONED...THE HEAVY RAIN
EVENT LOOKS LIKELY THROUGH THE SHORT TERM PERIOD AS MODELS CONTINUE
TO SHOW A STRONG LOW PRESSURE SYSTEM OVER THE GULF COAST MOVING
ACROSS OUR CWA MONDAY THROUGH TUESDAY. BY SUNDAY...EXPECT INCREASING
MOIST SOUTHERLY FLOW ACROSS THE REGION AS THE HIGH PRESSURE SHIFTS
EAST AND THE LOW PRESSURE SLOWLY APPROACHES FROM THE GULF COAST. AS
A RESULT...MOISTURE WILL DEEPEN AND INSTABILITY WILL BE GOOD ENOUGH
TO TRIGGER WIDESPREAD SHOWERS AND THUNDERSTORMS ON SUNDAY. AS THE
SOUTHERN STREAM SHORT WAVE TROUGH AND ASSOCIATED LOW PRESSURE SYSTEM
MOVE ACROSS AL/GA MONDAY...STRONG 250 MB UPPER LEVEL JET DEVELOPS
JUST TO OUR NORTHEAST AND LINGERS THROUGH TUESDAY ALLOWING GOOD
UPPER DIVERGENCE ACROSS OUR CWA. WITH CONTINUED DEEPENING
MOISTURE...GOOD UPPER LEVEL FORCING AND INSTABILITY...WILL KEEP
LIKELY POPS ON MONDAY.
THE HEAVIEST RAIN WILL OCCUR MONDAY NIGHT THROUGH TUESDAY MORNING AS
THE CENTER OF LOW PRESSURE MOVES ACROSS OUR CWA. THE UPPER FORCING
WILL BE THE STRONGEST IN THIS PERIOD WITH THE AID OF WARM AIR
ADVECTION DRIVEN BY STRONG 850 MB SOUTHERLY JET...POSITIVE VORTICITY
ADVECTION AND GOOD UPPER LEVEL DIVERGENCE. THE LATEST MODEL RUNS
SHOW HIGHER TOTAL QPF VALUES WITH 2-4 INCHES OVER THE PIEDMONT AND
HIGHER AMOUNTS IN THE MOUNTAINS. SEVERE WEATHER IS NOT OUT OF THE
QUESTION AS MODELS CONTINUE TO SHOW 0-3 KM BULK SHEAR MAGNITUDE OF
25-30KTS OVERLAPPING DECENT CAPE VALUES OVER OUR AREA. PRECIP WILL
DECREASE FROM WEST TO EAST TUESDAY AS AN ASSOCIATED COLD FRONT
PUSHES SE ACROSS THE REGION AND DRIER AIRMASS MOVES IN FROM THE NW
BY LATE TUESDAY. TEMPERATURES WILL BE NEAR NORMAL ON SUNDAY BEFORE
DROPPING BY 3-5 DEGREES BELOW NORMAL MON/TUE.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 2 AM SATURDAY...THE LATEST MEDIUM RANGE MODELS CONTINUE TO
INDICATE THAT DRY SURFACE HIGH PRESSURE WILL BUILD IN FROM THE NORTH
WEDNESDAY AND REMAIN IN PLACE THROUGH FRIDAY. THIS WILL RESULT IN
CONTINUED DRY WEATHER AND COOL TEMPERATURES ACROSS THE REGION
THROUGH FRIDAY. TEMPERATURES WILL STAY 5-10 DEGREES BELOW NORMAL
WED/THU WITH AFTERNOON HIGHS IN THE MID 70S OVER THE PIEDMONT AND
60S IN THE MOUNTAINS. WITH COLD AIR ADVECTION AND CLEAR
SKIES...OVERNIGHT LOWS WILL PLUNGE INTO THE LOW 50S OVER THE
PIEDMONT AND 40S IN THE VALLEYS/MOUNTAINS THROUGH THE PERIOD.
TEMPERATURES SHOULD RISE BY 3-5 DEGREES F BY FRIDAY AS HIGH PRESSURE
SHIFTS EAST AND LLVL FLOW BECOMES SOUTHERLY. ANOTHER COLD FONT WILL
APPROACH THE APPALACHIANS BY FRIDAY NIGHT/SATURDAY MORNING FOR LOW
END/SLIGHT CHANCE POP THERE.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...ALREADY MIXING DOWN SOME STRONGER WINDS NEAR 8 KT PER SFC
OBS. THIS IS SUPPORTED BY VAD WINDS FROM TERMINAL DOPPLER AND GOES
SOUNDING THERMAL PROFILE. DESPITE DEEP MIXING TODAY...WINDS IN THE
MIXED LAYER WILL BE FAIRLY WEAK AND EXCEPT FOR OCCASIONAL GUSTS
ABOVE 10 KT DOUBT WE WILL SEE MUCH FURTHER INCREASE FROM CURRENT
OBS. ALSO IT APPEARS TOO DRY IN THE LOW LEVELS TO GET MUCH CUMULUS
DEVELOPMENT BUT A FEW VFR CU ARE NOT OUT OF THE QUESTION THIS
AFTERNOON.
ELSEWHERE...SOME FOG REMAINS IN THE MOUNTAIN VALLEYS AS OF 1030 AM
EDT BUT VSBY AT ALL OBS SITES HAS IMPROVED TO VFR. ENOUGH LOW LEVEL
MOISTURE WILL RETURN TO THE MOUNTAINS FOR A CHANCE OF THUNDER THIS
AFTERNOON...BUT NOT ENOUGH OF A CHANCE TO MENTION AT KAVL.
PRECIPITATION CHANCES WERE LOWERED SLIGHTLY FROM PREVIOUS FORECAST
AND DELAYED UNTIL AFTER 18Z. LOW LEVEL MOISTURE WILL INCREASE ACROSS
THE AREA THIS EVENING AS ISENTROPIC UPGLIDE SETS UP OVER THE
STALLING FRONT TO OUR SOUTH...BRINGING LOW VFR CIGS TO THE AREA.
PRECIPITATION CHANCES ARE TOO LOW TO MENTION IN THE TAFS. THE MODEL
GUIDANCE CONSENSUS FAVORS MVFR FOG AT MOST SITES SUNDAY
MORNING...AND IFR AT KAVL. WITH LIMITED CONFIDENCE...VFR WILL BE
MAINTAINED FOR NOW. WINDS WILL VEER FROM N TO NE TODAY...THEN GO
CALM TONIGHT.
OUTLOOK...A SLOW MOVING COLD FRONT WILL BE STALLED TO OUR SOUTH
SUNDAY. LOW PRESSURE WILL SUPPLY DEEP MOISTURE ACROSS THE REGION
SUNDAY NIGHT THROUGH MONDAY...AND RESTRICTIONS ARE LIKELY. A STRONG
COLD FRONT IS EXPECTED TO REACH THE REGION BY MID WEEK...BRINGING IN
DRIER AIR.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...JAT/WIMBERLEY
SHORT TERM...JOH
LONG TERM...JOH
AVIATION...JAT/WIMBERLEY
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1058 AM CDT SAT SEP 15 2012
.DISCUSSION...CONVECTION HAS REMAINED OVER THE GULF WATERS NEAR
THE FRONTAL BOUNDARY LOCATED OVER THE NEARSHORE WATERS. THE BOUNDARY
IS EXPECTED TO DRIFT INLAND BY THIS AFTERNOON AS WINDS OFFSHORE
HAVE SHIFTED TO THE EAST. EXPECT THE FRONT WILL REMAIN A FOCUS FOR
CONVECTIVE DEVELOPMENT. 12Z CRP SOUNDING SHOWED PLENTIFUL MOISTURE
WITH PRECIPITABLE WATER AT 2.14 INCHES. ONCE FRONTAL INVERSION IS
REMOVED WITH A LITTLE BIT OF HEATING...EXPECT CONVECTION WILL FORM
DURING THE AFTERNOON OVER THE COASTAL PLAINS. THE 00Z 4KM WRF MODEL
GIVES A BIT OF CONFIDENCE IN THIS SCENARIO. WILL HAVE TO WAIT UNTIL
TONIGHT FOR UPPER DYNAMICS TO APPROACH FOR BETTER RAIN CHANCES OUT
WEST. WOULD PREFER TO SEE BETTER LOW LEVEL THERMAL ADVECTION
PROFILE FOR LIKELY POPS BUT ENERGETIC UPPER LEVEL JET STREAK
COMING OUT OF NORTHERN MEXICO INTO CENTRAL TEXAS SHOULD PROVIDE
SUFFICIENT LIFT TO WARRANT THE HIGH POPS NORTHWEST FOR LATER
TONIGHT. LOWERED MAX TEMPS A CATEGORY FOR NORTHERN BRUSH COUNTRY
TODAY.
&&
.PREV DISCUSSION... /ISSUED 639 AM CDT SAT SEP 15 2012/
DISCUSSION...UPDATE FOR 12Z AVIATION BELOW.
AVIATION...COLD FRONT HAS BECOME STATIONARY JUST OFFSHORE EARLY
THIS MORNING WITH N TO NE WINDS AROUND 10 KTS PREVAILING BEHIND IT
ACROSS SOUTH TEXAS TERMINALS. BKN MVFR CIGS WILL PREVAIL THROUGH
THE MORNING AT MANY TAF SITES. IN ADDITION...ISOLATED SHRA
POSSIBLE DURING THE MORNING NEAR VCT. NUMEROUS SHOWERS AND
THUNDERSTORMS LOCATED NEAR THE FRONT SHOULD REMAIN JUST OFFSHORE
THROUGH THE MORNING. THE FRONT WILL WEAKEN AND WASH OUT IN THE
AFTERNOON. AS THIS HAPPENS...CIGS WILL BECOME VFR ACROSS SOUTH
TEXAS TERMINALS AND ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS WILL DEVELOP INLAND.
PREV DISCUSSION... /ISSUED 357 AM CDT SAT SEP 15 2012/
SHORT TERM (TODAY THROUGH SUNDAY)...MSAS ANALYSIS REVEALS FRONTAL
HAS BECOME STATIONARY EARLY THIS MORNING ACROSS THE NEARSHORE
MIDDLE TEXAS COASTAL WATERS. WEAK MID/UPPER LEVEL CYCLONIC SHEAR
AXIS ALSO OVER THE REGION...AND THE TWO FEATURES ARE INTERACTING
WITH DEEP MOISTURE AND GENERATING NUMEROUS SHOWERS AND THUNDERSTORMS
JUST OFFSHORE. GFS/NAM IN ADDITION TO HRRR AND NSSL 4 KM WRF
INDICATE THE BOUNDARY REMAINING JUST OFFSHORE THROUGH THE MORNING
HOURS...ALTHOUGH A SLIGHT WESTWARD DRIFT IN THE CONVECTION IS
LIKELY TO OCCUR. SOME OF THESE SHOWERS AND THUNDERSTORMS MAY
SNEAK ACROSS THE BARRIER ISLANDS INTO COASTAL LOCATIONS OF NUECES
AND KLEBERG COUNTIES THROUGH THE MORNING...BUT THE BULK OF THE
CONVECTION WILL REMAIN JUST OFFSHORE. FURTHER INLAND ACROSS SOUTH
TEXAS...A FEW WEAK SHOWERS MAY DEVELOP TOWARDS AND AFTER SUNRISE.
A SHARP GRADIENT IN POPS IS INDICATED THIS MORNING. LATER THIS
AFTERNOON...THE BOUNDARY DRIFTS BACK INLAND AND WASHES OUT. A
RETURN TO WEAK ONSHORE FLOW SHOULD ALLOW FOR ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS TO DEVELOP ACROSS THE INLAND COASTAL
BEND AND BRUSH COUNTRY MID TO LATE AFTERNOON.
ATTENTION THEN SHIFTS TO LATE TONIGHT INTO SUNDAY. POSITIVELY
TILTED TROUGH APPROACHES THE RIO GRANDE PLAINS AFTER MIDNIGHT
ALONG WITH A MODEST 50-60 KT UPPER LEVEL JET STREAK. MID/UPPER
LEVEL FORCING WILL GRADUALLY INCREASE OVERNIGHT AND PEAK ACROSS
THE RIO GRANDE PLAINS AND WESTERN BRUSH COUNTRY AROUND 12Z SUNDAY.
THE FORCING GRADUALLY MOVES EASTWARD DURING THE SUNDAY...INTO THE
COASTAL BEND/VICTORIA REGION MIDDAY. SHOWERS AND THUNDERSTORMS ARE
LIKELY ACROSS WESTERN CWA OVERNIGHT AND EARLY SUNDAY MORNING...AND
ACROSS THE EAST LATE SUNDAY MORNING THROUGH AFTERNOON. POPS ARE
HIGHEST ACROSS THE NORTH AND NORTHEAST CWA SUNDAY. HIGH TEMPS VERY
DEPENDENT ON CLOUD COVER AND RAINFALL TODAY AND SUNDAY...GENERALLY
IN THE MID AND UPPER 80S.
LONG TERM (SUNDAY NIGHT THROUGH SATURDAY)...MID LVL TROUGH WILL
ADVANCE INTO THE COASTAL WATERS SUN NIGHT WITH PCPN ENDING OVER THE
WATERS BY MONDAY MORNING. CLEARING SKIES AND SUBSIDENT FLOW WILL
ALLOW TEMPS TO RECOVER INTO THE 90S AREA WIDE. ANOTHER TROUGH AND
ASSOCIATED WEAK COOL FRONT WILL DIP INTO SOUTH TEXAS TUESDAY.
HOWEVER NOT EXPECTING PCPN DUE TO DRY ATMOSPHIC COLUMN (PWS NEAR
1.3"). ENOUGH MOISTURE WILL POOL ALONG THE BOUNDARY OVER THE GULF
WATERS BY WED AM TO GENERATE A FEW SHOWERS. A WEAK MID LVL RIDGE
WILL BUILD BACK OVER SOUTH TEXAS THROUGH THE REMAINDER OF THE WEEK
WITH A GRADUAL WARMING TREND AND NO SIGNIFICANT OPPORTUNITIES FOR
RAINFALL. A WEAK TO MODERATE ONSHORE FLOW WILL PERSIST THROUGH THE
END OF THE FORECAST PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 89 71 87 70 90 / 50 40 70 20 10
VICTORIA 88 68 86 67 90 / 50 50 80 30 10
LAREDO 88 70 88 71 98 / 40 60 50 10 10
ALICE 89 69 87 68 93 / 50 40 70 20 10
ROCKPORT 86 71 85 71 89 / 50 40 80 30 10
COTULLA 84 67 85 68 94 / 40 70 70 10 10
KINGSVILLE 88 70 87 69 91 / 50 40 70 20 10
NAVY CORPUS 86 73 86 73 87 / 50 40 70 20 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
TT/89...SHORT TERM
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
639 AM CDT SAT SEP 15 2012
.DISCUSSION...UPDATE FOR 12Z AVIATION BELOW.
&&
.AVIATION...COLD FRONT HAS BECOME STATIONARY JUST OFFSHORE EARLY
THIS MORNING WITH N TO NE WINDS AROUND 10 KTS PREVAILING BEHIND IT
ACROSS SOUTH TEXAS TERMINALS. BKN MVFR CIGS WILL PREVAIL THROUGH
THE MORNING AT MANY TAF SITES. IN ADDITION...ISOLATED SHRA
POSSIBLE DURING THE MORNING NEAR VCT. NUMEROUS SHOWERS AND
THUNDERSTORMS LOCATED NEAR THE FRONT SHOULD REMAIN JUST OFFSHORE
THROUGH THE MORNING. THE FRONT WILL WEAKEN AND WASH OUT IN THE
AFTERNOON. AS THIS HAPPENS...CIGS WILL BECOME VFR ACROSS SOUTH
TEXAS TERMINALS AND ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS WILL DEVELOP INLAND.
&&
.PREV DISCUSSION... /ISSUED 357 AM CDT SAT SEP 15 2012/
SHORT TERM (TODAY THROUGH SUNDAY)...MSAS ANALYSIS REVEALS FRONTAL
HAS BECOME STATIONARY EARLY THIS MORNING ACROSS THE NEARSHORE
MIDDLE TEXAS COASTAL WATERS. WEAK MID/UPPER LEVEL CYCLONIC SHEAR
AXIS ALSO OVER THE REGION...AND THE TWO FEATURES ARE INTERACTING
WITH DEEP MOISTURE AND GENERATING NUMEROUS SHOWERS AND THUNDERSTORMS
JUST OFFSHORE. GFS/NAM IN ADDITION TO HRRR AND NSSL 4 KM WRF
INDICATE THE BOUNDARY REMAINING JUST OFFSHORE THROUGH THE MORNING
HOURS...ALTHOUGH A SLIGHT WESTWARD DRIFT IN THE CONVECTION IS
LIKELY TO OCCUR. SOME OF THESE SHOWERS AND THUNDERSTORMS MAY
SNEAK ACROSS THE BARRIER ISLANDS INTO COASTAL LOCATIONS OF NUECES
AND KLEBERG COUNTIES THROUGH THE MORNING...BUT THE BULK OF THE
CONVECTION WILL REMAIN JUST OFFSHORE. FURTHER INLAND ACROSS SOUTH
TEXAS...A FEW WEAK SHOWERS MAY DEVELOP TOWARDS AND AFTER SUNRISE.
A SHARP GRADIENT IN POPS IS INDICATED THIS MORNING. LATER THIS
AFTERNOON...THE BOUNDARY DRIFTS BACK INLAND AND WASHES OUT. A
RETURN TO WEAK ONSHORE FLOW SHOULD ALLOW FOR ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS TO DEVELOP ACROSS THE INLAND COASTAL
BEND AND BRUSH COUNTRY MID TO LATE AFTERNOON.
ATTENTION THEN SHIFTS TO LATE TONIGHT INTO SUNDAY. POSITIVELY
TILTED TROUGH APPROACHES THE RIO GRANDE PLAINS AFTER MIDNIGHT
ALONG WITH A MODEST 50-60 KT UPPER LEVEL JET STREAK. MID/UPPER
LEVEL FORCING WILL GRADUALLY INCREASE OVERNIGHT AND PEAK ACROSS
THE RIO GRANDE PLAINS AND WESTERN BRUSH COUNTRY AROUND 12Z SUNDAY.
THE FORCING GRADUALLY MOVES EASTWARD DURING THE SUNDAY...INTO THE
COASTAL BEND/VICTORIA REGION MIDDAY. SHOWERS AND THUNDERSTORMS ARE
LIKELY ACROSS WESTERN CWA OVERNIGHT AND EARLY SUNDAY MORNING...AND
ACROSS THE EAST LATE SUNDAY MORNING THROUGH AFTERNOON. POPS ARE
HIGHEST ACROSS THE NORTH AND NORTHEAST CWA SUNDAY. HIGH TEMPS VERY
DEPENDENT ON CLOUD COVER AND RAINFALL TODAY AND SUNDAY...GENERALLY
IN THE MID AND UPPER 80S.
LONG TERM (SUNDAY NIGHT THROUGH SATURDAY)...MID LVL TROUGH WILL
ADVANCE INTO THE COASTAL WATERS SUN NIGHT WITH PCPN ENDING OVER THE
WATERS BY MONDAY MORNING. CLEARING SKIES AND SUBSIDENT FLOW WILL
ALLOW TEMPS TO RECOVER INTO THE 90S AREA WIDE. ANOTHER TROUGH AND
ASSOCIATED WEAK COOL FRONT WILL DIP INTO SOUTH TEXAS TUESDAY.
HOWEVER NOT EXPECTING PCPN DUE TO DRY ATMOSPHIC COLUMN (PWS NEAR
1.3"). ENOUGH MOISTURE WILL POOL ALONG THE BOUNDARY OVER THE GULF
WATERS BY WED AM TO GENERATE A FEW SHOWERS. A WEAK MID LVL RIDGE
WILL BUILD BACK OVER SOUTH TEXAS THROUGH THE REMAINDER OF THE WEEK
WITH A GRADUAL WARMING TREND AND NO SIGNIFICANT OPPORTUNITIES FOR
RAINFALL. A WEAK TO MODERATE ONSHORE FLOW WILL PERSIST THROUGH THE
END OF THE FORECAST PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 71 87 70 90 71 / 40 70 20 10 10
VICTORIA 68 86 67 90 67 / 50 80 30 10 10
LAREDO 70 88 71 98 73 / 60 50 10 10 10
ALICE 69 87 68 93 69 / 40 70 20 10 10
ROCKPORT 71 85 71 89 73 / 40 80 30 10 10
COTULLA 67 85 68 94 69 / 70 70 10 10 10
KINGSVILLE 70 87 69 91 70 / 40 70 20 10 10
NAVY CORPUS 73 86 73 87 75 / 40 70 20 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
JR/76...SHORT TERM/AVIATION
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
221 PM CDT SAT SEP 15 2012
...UPDATED LONG TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 210 PM CDT SAT SEP 15 2012
IN THE HIGHER LEVELS OF THE ATMOSPHERE, THERE WAS A LIGHT 250MB JET
FROM CENTRAL OLD MEXICO NORTHEAST THROUGH TEXAS AND OKLAHOMA TO THE
EAST COAST OVER COASTAL NORTH CAROLINA. THE AVERAGE SPEED IN THIS
JET WAS 60 KNOTS, WITH A SMALL PEAK JETLET AROUND 70 KNOTS DOWN IN
THE WEST TEXAS PANHANDLE. IN THE NORTHEASTERN PART OF THE U.S.,
THERE WAS TROUGH WITH 90 KNOTS OF NORTHWEST WINDS ON THE WEST SIDE
OF THE TROUGH, OVER THE NORTHEASTERN GREAT LAKES, THEN CURVING TO A
90 KNOT SOUTHERLY JET OVER EASTERN QUEBEC, CANADA. THE 500MB CHART
SHOWED HIGH PRESSURE CENTERED OVER WESTERN UTAH STRETCHING EAST
THROUGH KANSAS, WITH AN UPPER LOW OVER QUEBEC AND ANOTHER OVER THE
GULF OF MEXICO. THE 700MB PATTERN WAS SIMILAR TO THE 500MB LEVEL,
WITH A NORTHEAST WIND AT DDC OF 05 KNOTS AND A 700MB TEMP OF +05.
THE 850MB ANALYSIS SHOWED A WEALTH OF MOISTURE MOVING NORTHEASTWARD
FROM THE TEXAS GULF COAST TO CENTRAL AND EASTERN KANSAS. A WARM
FRONT WAS TO OUR NORTH, FROM SOUTHERN SASKATCHEWAN TO THE EASTERN
DAKOTAS TO SOUTH CENTRAL NEBRASKA. A COLD FRONT WAS EVIDENT FROM AN
850MB LOW PRESSURE CENTER OVER CENTRAL OKLAHOMA SOUTHWESTWARD TO
WEST TEXAS AND THEN WEST TO A LOW OVER WESTERN MEXICO.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 210 PM CDT SAT SEP 15 2012
FOR TONIGHT, HIGH PRESSURE OVERHEAD WILL ALLOW CLEAR OR CLEARING
SKIES, LIGHT SOUTHEAST WINDS IN OUR CENTRAL AND EAST, BUT A TROUGH
IN COLORADO SHOULD TURN WINDS LIGHT SOUTHWEST IN OUR WESTERN
COUNTIES. ALTHOUGH ONLY 5 TO 10 MPH SOUTHWEST WINDS WILL BE OVER
OUR WESTERN COUNTIES, THINK THE UPSLOPE FLOW AFFECT WILL HELP
TEMPERATURES FROM FALLING AS PREVIOUSLY FORECAST. I RAISED MINIMUM
TEMPERATURES IN OUR CENTRAL AND WEST, WHICH NOW FIT BETTER WITH OUR
ISC NEIGHBORS. REVIEWED LAST NIGHT LOWS, WITH GCK AND HYS BOTTOMING
OUT AT 41F, AND THINK THEY SHOULD BE NEAR THAT LEVEL IN THE WEST
TONIGHT. ALL MODEL GUIDANCE IS EVEN HIGHER, IN THE MID 40S OUT
WEST, BUT DID NOT WANT TO SEE-SAW BACK AND FORTH TOO MUCH. IN THE
NEARER TERM, THE NAM AND HRRR MODELS BOTH PRODUCED A LITTLE LIGHT
RAIN IN MY EXTREME SOUTHEAST BY 19Z TODAY. SINCE THIS HAS NOT
MATERIALIZED, DECIDED TO LEAVE POPS OUT OF OUR SOUTHEAST COUNTIES
SUCH AS COMANCHE AND BARBER.
SUNDAY WILL SEE THE SURFACE TROUGH IN OUR WESTERN COUNTIES, PERHAPS
AS FAR EAST AT KEARNY, GRANT AND STEVENS COUNTIES. WINDS WILL SHIFT
SOUTH AND BY AFTERNOON INCREASE INTO THE 12 TO 15 MPH RANGE, GUSTING
TO NEAR 20 MPH. THIS SOUTH WIND WILL AID IN TRANSPORTING WARMER AIR
INTO SOUTHWESTERN KANSAS, ALLOWING MAXIMUM TEMPERATURES TO WARM
APPROXIMATELY 10F DEGREES MORE THAN TODAY. SUNDAY`S HIGHS SHOULD
RANGE FROM 84F IN HAYS AND DODGE CITY TO 89F IN SYRACUSE. HIGH
PRESSURE ALOFT OVER THE PLAINS WILL STILL KEEP A LOT OF SUNSHINE
OVERHEAD, WHICH WILL ALSO AID IN WARMING UP THE SURFACE.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 218 PM CDT SAT SEP 15 2012
AN UPPER LEVEL TROUGH WILL EXIT CANADA AND MOVE SOUTHEAST ACROSS THE
NORTHERN PLAINS SUNDAY NIGHT AND MONDAY. AS THIS SYSTEM CROSSES THE
NORTHERN PLAINS A COLD FRONT WILL MOVE ACROSS WESTERN KANSAS.
PRECIPITATION CHANCES WITH THIS COLD FRONT AT THIS TIME STILL
APPEARS SMALL. IF PRECIPITATION DOES OCCUR IT WILL BE ON MONDAY AS
THE UPPER TROUGH CROSSES PORTIONS OF NORTH CENTRAL KANSAS. ANOTHER
AREA WHERE A FEW SHOWERS OR EVEN A THUNDERSTORM MAY DEVELOP WILL BE
IN FAR SOUTHWEST KANSAS NEAR THE LEFT EXIT REGION OF AN UPPER LEVEL
JET. GIVEN THE EXPECTED CLOUD COVER AND THE COOLING THAT IS FORECAST
BEHIND THIS FRONT IN THE 925-850MB LEVEL WILL TREND HIGHS DOWN A
COUPLE OF DEGREES AND FAVOR THE COOLEST MODEL GUIDANCE. HIGHS MONDAY
MAY STRUGGLE TO REACH THE UPPER 60S ACROSS PORTIONS OF WESTERN AND
NORTH CENTRAL KANSAS. GUSTY NORTH WINDS WILL DEVELOP BEHIND THIS
FRONT EARLY MONDAY. NAM MEAN MIXED LAYER WINDS SUGGESTING SUSTAINED
WIND SPEEDS OF 30 TO 35 MPH AT 15Z AND 18Z MONDAY. GFS WAS A LITTLE
WEAKER WITH THESE MIXED LAYER WINDS BUT GIVEN THE MAGNITUDE OF THE
COLD AIR ADVECTION DEVELOPING EARLY MONDAY WILL LEAN TOWARDS THE
STRONGER NAM WINDS AT THIS TIME.
BY MONDAY NIGHT THE UPPER LEVEL TROUGH WILL MOVE EAST OF THE AREA AS
AN AREA OF HIGH PRESSURE AT THE SURFACE BEGINS TO SETTLE INTO
KANSAS. SKIES MAY BE CLEAR EARLY BUT BASED ON THE GFS AND ECMWF SOME
700MB MOISTURE AND WARM AIR ADVECTION IMPROVES DURING THE OVERNIGHT
HOURS ACROSS WESTERN KANSAS. GIVEN LIGHT WINDS AND DEWPOINT IN THE
UPPER 30S TO LOWER 40S WILL FAVOR THE COOLER GUIDANCE FOR OVERNIGHT
TEMPERATURES BUT AM RELUCTANT TO GO MUCH LOWER THAN THE MID 40S
GIVEN THE POTENTIAL FOR SOME CLOUD COVER TOWARDS DAYBREAK.
ON TUESDAY A TROUGH OF LOW PRESSURE A THE SURFACE WILL DEVELOP ALONG
THE LEE OF THE ROCKIES AS A NORTHWEST FLOW PERSISTS. 850MB
TEMPERATURE TRENDS TUESDAY AND WEDNESDAY CONTINUES TO SUPPORT HIGHS
REBOUNDING BACK INTO THE 80S. THIS WARM UP HOWEVER WILL BE SHORT
LIVED AS ANOTHER COLD FRONT IS FORECAST TO MOVE SOUTH ACROSS THE
CENTRAL PLAINS WEDNESDAY NIGHT OR EARLY THURSDAY. NOT ONLY WILL THIS
FRONT BRING COOLER TEMPERATURES BACK TO WESTERN KANSAS BUT THERE MAY
ALSO BE A SLIGHT CHANCE FOR THUNDERSTORMS AS WELL AS ANOTHER UPPER
LEVEL TROUGH CROSSES THE NORTHERN PLAINS. AT THIS TIME MODELS APPEAR
TO BE STRUGGLING WITH THE TRACK AND STRENGTH OF THIS NEXT UPPER
LEVEL SYSTEM. CONFIDENCE IS NOT HIGH ON WHICH MAY BE MORE CORRECT SO
WILL STAY CLOSE TO CONSENSUS FROM THE CREXTENDFCST_INT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1149 AM CDT SAT SEP 15 2012
SURFACE HIGH PRESSURE OVER KANSAS WILL KEEP VFR CONDITIONS
PREVAILING THROUGH THE 24 HOUR TAF PERIOD. CLEAR SKIES WILL
DOMINATE THE TAF SITES, BUT JUST EAST OF THE SITES NEAR MEDICINE
LODGE (P28) AND PRATT (PTT) MVFR CIGS AROUND BKN-OVC025-030 WILL
LINGER THIS AFTERNOON IN ISENTROPIC LIFT FROM OKLAHOMA. LIGHT AND
VARIABLE WINDS EARLY THIS AFTERNOON WILL SHIFT SOUTHEAST AT UNDER
10 KNOTS BY 20Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 53 84 52 72 / 0 0 10 10
GCK 51 87 51 71 / 0 0 10 10
EHA 51 87 52 71 / 0 0 10 10
LBL 50 86 52 73 / 0 0 0 0
HYS 53 85 55 70 / 0 0 10 20
P28 57 85 58 76 / 0 0 10 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURKE
SHORT TERM...BURKE
LONG TERM...BURGERT
AVIATION...BURKE
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
214 PM CDT SAT SEP 15 2012
...UPDATED FOR THE SYNOPSIS AND SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 210 PM CDT SAT SEP 15 2012
IN THE HIGHER LEVELS OF THE ATMOSPHERE, THERE WAS A LIGHT 250MB JET
FROM CENTRAL OLD MEXICO NORTHEAST THROUGH TEXAS AND OKLAHOMA TO THE
EAST COAST OVER COASTAL NORTH CAROLINA. THE AVERAGE SPEED IN THIS
JET WAS 60 KNOTS, WITH A SMALL PEAK JETLET AROUND 70 KNOTS DOWN IN
THE WEST TEXAS PANHANDLE. IN THE NORTHEASTERN PART OF THE U.S.,
THERE WAS TROUGH WITH 90 KNOTS OF NORTHWEST WINDS ON THE WEST SIDE
OF THE TROUGH, OVER THE NORTHEASTERN GREAT LAKES, THEN CURVING TO A
90 KNOT SOUTHERLY JET OVER EASTERN QUEBEC, CANADA. THE 500MB CHART
SHOWED HIGH PRESSURE CENTERED OVER WESTERN UTAH STRETCHING EAST
THROUGH KANSAS, WITH AN UPPER LOW OVER QUEBEC AND ANOTHER OVER THE
GULF OF MEXICO. THE 700MB PATTERN WAS SIMILAR TO THE 500MB LEVEL,
WITH A NORTHEAST WIND AT DDC OF 05 KNOTS AND A 700MB TEMP OF +05.
THE 850MB ANALYSIS SHOWED A WEALTH OF MOISTURE MOVING NORTHEASTWARD
FROM THE TEXAS GULF COAST TO CENTRAL AND EASTERN KANSAS. A WARM
FRONT WAS TO OUR NORTH, FROM SOUTHERN SASKATCHEWAN TO THE EASTERN
DAKOTAS TO SOUTH CENTRAL NEBRASKA. A COLD FRONT WAS EVIDENT FROM AN
850MB LOW PRESSURE CENTER OVER CENTRAL OKLAHOMA SOUTHWESTWARD TO
WEST TEXAS AND THEN WEST TO A LOW OVER WESTERN MEXICO.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 210 PM CDT SAT SEP 15 2012
FOR TONIGHT, HIGH PRESSURE OVERHEAD WILL ALLOW CLEAR OR CLEARING
SKIES, LIGHT SOUTHEAST WINDS IN OUR CENTRAL AND EAST, BUT A TROUGH
IN COLORADO SHOULD TURN WINDS LIGHT SOUTHWEST IN OUR WESTERN
COUNTIES. ALTHOUGH ONLY 5 TO 10 MPH SOUTHWEST WINDS WILL BE OVER
OUR WESTERN COUNTIES, THINK THE UPSLOPE FLOW AFFECT WILL HELP
TEMPERATURES FROM FALLING AS PREVIOUSLY FORECAST. I RAISED MINIMUM
TEMPERATURES IN OUR CENTRAL AND WEST, WHICH NOW FIT BETTER WITH OUR
ISC NEIGHBORS. REVIEWED LAST NIGHT LOWS, WITH GCK AND HYS BOTTOMING
OUT AT 41F, AND THINK THEY SHOULD BE NEAR THAT LEVEL IN THE WEST
TONIGHT. ALL MODEL GUIDANCE IS EVEN HIGHER, IN THE MID 40S OUT
WEST, BUT DID NOT WANT TO SEE-SAW BACK AND FORTH TOO MUCH. IN THE
NEARER TERM, THE NAM AND HRRR MODELS BOTH PRODUCED A LITTLE LIGHT
RAIN IN MY EXTREME SOUTHEAST BY 19Z TODAY. SINCE THIS HAS NOT
MATERIALIZED, DECIDED TO LEAVE POPS OUT OF OUR SOUTHEAST COUNTIES
SUCH AS COMANCHE AND BARBER.
SUNDAY WILL SEE THE SURFACE TROUGH IN OUR WESTERN COUNTIES, PERHAPS
AS FAR EAST AT KEARNY, GRANT AND STEVENS COUNTIES. WINDS WILL SHIFT
SOUTH AND BY AFTERNOON INCREASE INTO THE 12 TO 15 MPH RANGE, GUSTING
TO NEAR 20 MPH. THIS SOUTH WIND WILL AID IN TRANSPORTING WARMER AIR
INTO SOUTHWESTERN KANSAS, ALLOWING MAXIMUM TEMPERATURES TO WARM
APPROXIMATELY 10F DEGREES MORE THAN TODAY. SUNDAY`S HIGHS SHOULD
RANGE FROM 84F IN HAYS AND DODGE CITY TO 89F IN SYRACUSE. HIGH
PRESSURE ALOFT OVER THE PLAINS WILL STILL KEEP A LOT OF SUNSHINE
OVERHEAD, WHICH WILL ALSO AID IN WARMING UP THE SURFACE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 326 AM CDT SAT SEP 15 2012
FOG WILL PROBABLY NOT LAST LONG ON SUNDAY MORNING. WINDS WILL BECOME
SOUTHERLY AND THEN WESTERLY RATHER QUICKLY, WHICH IS NOT AS
CONDUCIVE TO MAINTAINING FOG AS SOUTHEASTERLY. BY THE AFTERNOON,
VERY DRY MID LEVEL AIR WILL BE IN PLACE, ALONG WITH A WARMING
BOUNDARY LAYER. UPPER 80S COULD BE EXPECTED ON THE WESTERN COUNTIES,
WITH MID 80S ELSEWHERE AS THE MID LEVEL HEIGHTS AND SUBSIDENCE
INCREASES. SUNDAY NIGHT WILL REMAIN RELATIVELY MILD AS LIGHT
SOUTHERLY WINDS AND THE SAME AIRMASS REMAINS IN PLACE. AT SOME
POINT, WEAK SHOWERS OR VIRGA MIGHT BEGIN TO SPREAD INTO WESTERN KANSAS
FROM THE NORTH. THIS WOULD BE ASSOCIATED WITH INCREASING CYCLONIC
FLOW AND INTENSIFYING JET ENERGY INTO THE CENTRAL PLAINS THAT IS
ASSOCIATED WITH A STRONGLY AMPLIFYING UPPER TROUGH OVER THE NORTHERN
PLAINS. A COLD SURFACE FRONT WILL DIVE INTO THE AREA BEFORE 12Z AND
MOVE RAPIDLY THROUGH ALL OF WESTERN KANSAS BY EARLY MORNING. WINDS
WILL PROBABLY AT LEAST BORDER ON OR EXCEED ADVISORY CRITERIA ACROSS
ALL OF WESTERN KANSAS AND MUCH OF CENTRAL KANSAS. THE GFS MOS WIND
SPEEDS SEEM MORE REASONABLE FOR THIS EPISODE, AND NUMERICAL MODELS
SEEM TO BE INCREASING WITH EACH RUN. COLD ADVECTION SHOULD LIMIT
HIGHS TO THE LOW 70S AT BEST MONDAY AFTERNOON.
A COOL NIGHT SHOULD BE EXPECTED MONDAY NIGHT INTO TUESDAY MORNING.
MOST OF THE MODEL OUTPUT ARE SOMEWHERE IN THE 40S WITH RESPECT TO
MINIMUM TEMPERATURES. A SLOW WARMING TREND IS THEN EXPECTED HEADING
INTO THE NEXT FEW DAYS IN THE MIDDLE TO LATE PART OF THE WEEK. WHILE
TUESDAY WILL SEE WARMING TEMPERATURES, WEDNESDAY APPEARS THE WARMEST
WITH HIGHS ON THE LATEST NAM WARMING TO NEAR 90S DEGREES NEAR THE
COLORADO LINE. ANOTHER WEAK COLD FRONT WILL ARRIVE LATE WEDNESDAY
AFTERNOON, WHICH COULD TEMPER HIGHS SEVERAL DEGREES LOWER FOR
THURSDAY AFTERNOON. CONSENSUS BETWEEN THE GFS AND ECMWF INDICATES
SHOWERS AND THUNDERSTORMS WOULD BE POSSIBLE ALONG THE CONVERGENCE
ZONE AS IT INTERACTS WITH A HIGHER THETA-E AIRMASS OVER SOUTH
CENTRAL KANSAS AND CENTRAL OKLAHOMA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1149 AM CDT SAT SEP 15 2012
SURFACE HIGH PRESSURE OVER KANSAS WILL KEEP VFR CONDITIONS
PREVAILING THROUGH THE 24 HOUR TAF PERIOD. CLEAR SKIES WILL
DOMINATE THE TAF SITES, BUT JUST EAST OF THE SITES NEAR MEDICINE
LODGE (P28) AND PRATT (PTT) MVFR CIGS AROUND BKN-OVC025-030 WILL
LINGER THIS AFTERNOON IN ISENTROPIC LIFT FROM OKLAHOMA. LIGHT AND
VARIABLE WINDS EARLY THIS AFTERNOON WILL SHIFT SOUTHEAST AT UNDER
10 KNOTS BY 20Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 53 84 52 72 / 0 0 10 10
GCK 51 87 51 71 / 0 0 10 10
EHA 51 87 52 71 / 0 0 10 10
LBL 50 86 52 73 / 0 0 0 0
HYS 53 85 55 70 / 0 0 10 20
P28 57 85 58 76 / 0 0 10 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURKE
SHORT TERM...BURKE
LONG TERM...RUSSELL
AVIATION...BURKE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
344 PM EDT SAT SEP 15 2012
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 339 PM EDT SAT SEP 15 2012
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A WNW FLOW ALF
OVER THE UPR GRT LKS TO THE W OF SLOWLY DEPARTING TROF IN QUEBEC AND
E OF MORE ZONAL FLOW OVER THE NRN ROCKIES. SFC HI PRES UNDER THE
CONFLUENT UPR FLOW IN THE GRT LKS IS CENTERED OVER SE ONTARIO JUST E
OF THE SAULT. SOME SC LINGERS OVER THE ERN CWA EARLY THIS AFTN IN
ASSOCIATION WITH DEPARTING H85 THERMAL TROF/LINGERING LLVL MSTR
SHOWN ON THE 12Z APX RAOB. BUT AS THE HI IS SHIFTING TO THE E...THE
SSW RETURN FLOW ON ITS WESTERN FLANK IS DRAWING WARMER/DRIER AIR
NOTED TO THE W BACK INTO THE UPR LKS. 12Z H85 TEMPS ARE AS HI AS 20C
AT BISMARCK. 12Z H85-7 DEWPT DEPRESSIONS ARE 20 TO 25C IN THE NRN
PLAINS...WHERE PWAT IS GENERALLY 0.25 TO 0.50 INCH...AS LITTLE AS 50
PCT OF NORMAL. MOISTER AIR AT H925-85 LURKS TO THE S IN KANSAS/
MISSOURI.
TONIGHT...AS THE HI TO THE E DRIFTS FARTHER AWAY UNDER WNW FLOW
ALF...THE LLVL WIND IS FCST TO SHIFT TO THE WSW IN ADVANCE OF LO
PRES TROF APRCHG FM THE W AHEAD OF SHRTWV EMBEDDED IN THE ZONAL FLOW
ALONG THE NDAKOTA/CNDN BORDER THIS MRNG. THIS FLOW IS PROGGED TO
ADVECT THE MUCH WARMER H85 AIR TO THE W THIS MRNG INTO THE UPR
LKS...WITH H85 TEMPS FCST TO RISE AS HI AS 16-18C AT IWD BY 12Z SUN.
ANY LINGERING LO CLDS OVER THE E SHOULD DISSIPATE EARLY WITH THE
ARRIVAL OF THIS WARMER AND DRIER AIR. ALTHOUGH THE AIRMASS IS
PROGGED TO REMAIN DRY THRU THE NGT...INCRSG H925 WINDS UP TO
30-35KTS LATE AS WELL AS THE ARRIVAL OF SOME PATCHY HI CLDS INDICATE
TNGT WL BE MUCH WARMER THAN THIS MRNG. EXPECT THE HIEST MIN TEMPS
OVER THE W AND NCNTRL NEAR LK SUP.
SUN...INCOMING LO PRES TROF IS PROGGED TO DRIFT INTO THE WRN CWA IN
THE AFTN AND INTERACT WITH H85 THERMAL RDG/AXIS OF H85 TEMPS IN THE
14-15C RANGE IN PLACE. ALTHOUGH MODELS INDICATE SW FLOW IN ADVANCE
OF THE TROF WL ADVECT MOISTER LLVL AIR IN KS/MO THIS MRNG INTO THE
UPR LKS...VERY DRY H85-7 AIR IN THE NRN PLAINS/ADJOINING SRN CAN AND
LACK OF SGNFT DYNAMIC FORCING TO ERODE MID LVL CAPPING/CAUSE H5
FALLS WL BE LIMITING FACTORS FOR PCPN. EVEN WITH THESE NEGATIVES...
SOME MODELS...ESPECIALLY THE CONSISTENT 12Z GFS...DO GENERATE SOME
PCPN OVER MAINLY THE NRN TIER COUNTIES ALONG AND AHEAD OF THE
INCOMING TROF. CONSIDERING THE NEGATIVES...OPTED TO FOLLOW THE DRIER
12Z NAM/LOCAL WRF-ARW MODELS AND MAINTAIN A PCPN-FREE FCST FOR MOST
OF THE CWA. DID RETAIN GOING SCHC POPS OVER WRN AND NCNTRL LK SUP
CLOSER TO MORE SUBSTANTIAL H5 FALLS ASSOCIATED WITH DEEPENING TROF
IN SCNTRL CAN. FCST STEEP H7-5 LAPSE RATES IN EXCESS OF 7C/KM
WARRANTS A MENTION OF TS IN THIS AREA DESPITE LIMITED MSTR.
MIXING TO H8 ON NAM/GFS FCST SDNGS YIELDS HI TEMPS NEAR 80 OVER THE
INTERIOR SCNTRL AWAY FM MODERATION OFF LK MI. WITH MORE MID/HI CLDS
AND/OR THE ARRIVAL OF THE TROF/WSHFT TO THE W...TEMPS OVER THE W AND
NRN TIER WL BE LOWER. THE COMBINATION OF THE UNSEASONABLE WARMTH
OVER MAINLY THE SCNTRL...GUSTY WSW WINDS TO 25-30 MPH ENHANCED BY
THE DEEPER MIXING...AND MIN RH DIPPING TO ARND 30 PCT AS DEWPTS MIX
OUT INTO THE 45-50 RANGE DESPITE SLOW ARRIVAL OF MORE LLVL MSTR
LATER IN THE DAY WL LEAD TO AN ELEVATED RISK OF WILDFIRES...
ESPECIALLY OVER THE CNTRL AND E WHERE THE PRES GRADIENT WL REMAIN
SHARPEST THRU THE DAY.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 339 PM EDT SAT SEP 15 2012
THE MAIN FORECAST CONCERN FOR SUNDAY NIGHT AND MONDAY ARE POPS
ASSOCIATED WITH THE UPPER TROUGH AND COLD FRONT MOVING INTO THE
UPPER LAKES. SUNDAY NIGHT SHOULD START OUT QUIET DESPITE THE COLD
FRONT BEING OVER WESTERN LAKE SUPERIOR. MOISTURE IS VERY LIMITED
ALONG THE FRONT SUNDAY EVENING...AND DYNAMICS ARE LACKING DUE TO THE
UPPER JET STILL BEING WELL WEST OVER THE UPPER MIDWEST.
HOWEVER...THIS IS EXPECTED TO CHANGE LATER SUNDAY NIGHT INTO MONDAY
AS THE UPPER TROUGH SHARPENS AS A RESULT OF THE 110 KT UPPER JET
DIVING SOUTH FROM THE YUKON SUNDAY NIGHT. THIS WILL ALLOW THE
UPSTREAM THERMAL GRADIENT TO TIGHTEN AND ASSOCIATED FRONTOGENETIC
CIRCULATION TO STRENGTHEN LATE SUNDAY AND INTO MONDAY AS IT MOVES
INTO UPPER MICHIGAN. MEANWHILE...DEEPER PACIFIC ORIGIN MOISTURE WILL
MOVE ACROSS THE REGION /WITH PRECIPITABLE WATER VALUES GREATER THAN
1 INCH/ AS SURFACE LOW PRESSURE DEVELOPS ALONG THE FRONT IN RESPONSE
TO THE RIGHT ENTRANCE REGION OF THE JET MOVING OVERHEAD. THERE ARE
SOME DIFFERENCES BETWEEN THE GFS AND NAM WITH REGARDS TO THE
PLACEMENT OF THE LOW AND THE MOVEMENT OF THE COLD FRONT...WITH THE
GFS BEING SLOWER AND AS SUCH FURTHER WEST WITH THE LOW PRES
DEVELOPMENT COMPARED TO THE NAM. THE NAM TENDS TO AGREE MORE WITH
THE 00Z ECMWF AND ALSO HAS SOME SUPPORT FROM SREF MEMBERS.
INCREASING 850MB COLD ADVECTION WILL ALLOW FOR INCREASING LAKE
INDUCED INSTABILITY LATE MONDAY INTO MONDAY NIGHT ON N-NW PBL WINDS
ON THE NW SIDE OF THE LOW. ALL OF THIS SHOULD COMBINE TO GIVE A
PERIOD OF STEADY RAIN STARTING LATE SUNDAY NIGHT AND CONTINUING
THROUGH MONDAY...AND IN FACT CONTINUING INTO MONDAY NIGHT INTO
TUESDAY FOR AREAS NEAR LAKE SUPERIOR. WITH THE LAKE AND TERRAIN
ENHANCEMENT DUE TO NORTHERLY FLOW OFF THE LAKE...SOME AREAS CLOSE TO
LAKE SUPERIOR COULD SEE 1-1.5 INCHES OF RAIN LATE SUNDAY
NIGHT-TUESDAY MORNING.
AS SUCH...HAVE OPTED TO MAKE ONLY MINOR TWEAKS TO THE GOING
FORECAST FOR SUNDAY NIGHT INTO TUESDAY. DUE TO THE EXTREMELY DRY
AIRMASS ALONG AND AHEAD OF THE FRONT...HAVE OPTED TO BACK OFF POPS
ESPECIALLY SUNDAY EVENING. ALTHOUGH IT MAY TAKE A LITTLE TIME FOR
THE FAR EAST TO SEE STEADY RAIN ON MONDAY DUE TO THE LOW PRESSURE
DEVELOPMENT ALONG THE FRONT KEEPING THAT AREA IN THE WARM SECTOR A
LITTLE LONGER...THE EXPECTATION IS THAT THE ENTIRE AREA WILL
EVENTUALLY SEE RAIN MONDAY. WILL THEREFORE GO WITH CATEGORICAL POPS
FOR THE ENTIRE FORECAST AREA ON MONDAY BUT WILL GO WITH THE HIGHEST
POPS ACROSS NORTH CENTRAL AND WESTERN UPPER MICHIGAN DUE TO THE
EVENTUAL LAKE/TERRAIN ENHANCEMENT DURING THE AFTERNOON. WILL
CONTINUE WITH CATEGORICAL POPS NEAR LAKE SUPERIOR ON MONDAY NIGHT
WITH NORTHERLY FLOW AND 850MB TEMPS DROPPING TO -3C...ALLOWING FOR
LAKE INDUCED EQUILIBRIUM LEVELS ABOVE 20KFT. WOULD NOT BE SHOCKED IF
THERE ARE SOME LIGHTNING STRIKES MONDAY NIGHT ESPECIALLY WITH THE
UPPER TROUGH OVERHEAD.
ALTHOUGH N-NW FLOW CONTINUES INTO TUESDAY...THE PBL FLOW BECOMES
NEUTRAL OR EVEN ANTI-CYCLONIC AS THE DAY GOES ON. IN ADDITION...THE
DEEP MOISTURE SHOULD BE SCOURED OUT AND THE BEST Q-VECT CONVERGENCE
MOVES EAST. DUE TO THE MODERATE LAKE INSTABILITY FROM 850MB TEMPS
AROUND -3C COMBINED WITH ONSHORE FLOW...CANNOT REMOVE POPS NEAR THE
LAKE...BUT WILL CONTINUE WITH SCATTERED POPS. BY TUESDAY
EVENING...IT SHOULD START TO CLEAR OUT AS THE UPR TROUGH MOVES EAST
AND THE SFC HIGH MOVES OVERHEAD. ALTHOUGH THE 12Z GFS IS QUITE
PROGRESSIVE IN MOVING THE HIGH TO THE EAST TUE NIGHT...THE GEM AND
ECMWF ARE CONSISTENT IN SHOWING A SLOWER AND LESS PROGRESSIVE SOLN.
WITH THE HIGH BEING OVERHEAD...IT LOOKS LIKE A GOOD RADIATIONAL
COOLING NIGHT ESPECIALLY ACROSS THE INTERIOR WEST AWAY FROM ANY
REMAINING LAKE CLOUDS...SO AREAS OF FROST ARE EXPECTED...IF NOT A
HARD FREEZE.
TEMPS FOR MONDAY/TUESDAY WILL REMAIN BELOW NORMAL...ALTHOUGH MONDAY
WILL BE WARMER THAN TUESDAY...ESPECIALLY ACROSS THE EAST. WITH 850MB
TEMPS AROUND -3C ON TUESDAY AND BLUSTERY N-NW FLOW...EXPECT TEMPS TO
STRUGGLE TO REACH 50...ESPECIALLY WHERE IT STAYS CLOUDY FOR MUCH OF
THE DAY NEAR LAKE SUPERIOR.
IN THE EXTENDED /WED-NEXT SATURDAY/...IT CERTAINLY LOOKS LIKE A
AUTUMN PATTERN ACROSS THE GREAT LAKES AS THE PATTERN WILL BE
DOMINATED BY AN INTENSIFYING LONGITUDINAL TROUGH ACROSS CENTRAL
CANADA AND EXTENDING SOUTHWARD INTO THE GREAT LAKES REGION BY THE
END OF THE WEEK. THIS WILL ALLOW FOR THE UNSETTLED AND COOL
WEATHER TO CONTINUE. AS FOR THE SPECIFICS...THE FIRST UPPER LOW THAT
WILL PLAGUE THE AREA EARLY IN THE WEEK WILL EJECT OUT TUE NIGHT/WED
IN RESPONSE TO ANOTHER SHORTWAVE DIVING DOWN THE BACK SIDE OF THE
LONG WAVE TROUGH. THIS SHOULD ALLOW FOR BRIEF RIDGING TO BUILD
ACROSS THE UPPER GREAT LAKES WED BEFORE THE NEXT SYSTEM MOVES IN AND
CLOSES OFF OVER THE GREAT LAKES BY FRI. AS SUCH...WILL CONTINUE WITH
CHANCE POPS FOR THE ENTIRE AREA THURSDAY. AS THE EVENT BECOMES A
LITTLE CLEARER IN THE NEXT FEW DAYS...POPS WILL LIKELY NEED TO BE
INCREASED IN THE FRIDAY/SATURDAY TIME PERIOD AS IT WILL BE COLD
ENOUGH ALOFT FOR LAKE ENHANCEMENT AND MOST OF THE NAEFS MEMBERS ALL
HAVE RAIN ON FRIDAY INTO SATURDAY. THE UPPER LOW SETTLES OVER THE
GREAT LAKES ON SATURDAY...ALTHOUGH THE ECMWF POSITION IS SOUTH OF
THE GFS POSITION. REGARDLESS...SATURDAY LOOKS UNSETTLED AND RATHER
WET. TEMPS THROUGH THE EXTENDED PERIOD WILL BE BELOW NORMAL. FRIDAY
AND ESPECIALLY SATURDAY COULD STRUGGLE TO GET OUT OF THE UPPER 40S
IF IT STAYS CLOUDY AND RAINY FOR THE ENTIRE DAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 124 PM EDT SAT SEP 15 2012
EXPECT VFR CONDITIONS TO PREVAIL THIS FCST PERIOD AT ALL 3 SITES
WITH DRY AIRMASS ASSOCIATED WITH HI PRES IN SE CANADA DOMINATING.
TIGHTENING PRES GRADIENT BTWN THE DEPARTING HI PRES AND A COLD FRONT
MOVING ACROSS THE NRN PLAINS WILL LEAD TO LLWS TONIGHT.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 339 PM EDT SAT SEP 15 2012
EXPECT ESE WINDS UP TO 20 KTS THIS AFTERNOON TO VEER TO THE WSW
TONIGHT INTO SUN AS HI PRES IN SE ONTARIO RETREATS TO THE E AND A LO
PRES TROF APPROACHES FROM THE NW.
LOW PRESSURE WILL DEVELOP ALONG A COLD FRONT MOVING ACROSS THE UPPER
LAKES ON MONDAY. IT WILL DEEPEN AT IT MOVES JUST EAST OF LAKE
SUPERIOR ON MONDAY. THE TIGHTENING PRESSURE GRADIENT COMBINED WITH
INCREASING LAKE INSTABILITY WILL ALLOW FOR GALE FORCE NORTHERLY
WINDS ACROSS CENTRAL LAKE SUPERIOR MONDAY AND THEN ACROSS THE EAST
HALF OF LAKE SUPERIOR MONDAY NIGHT. HIGH PRESSURE BUILDS IN TUESDAY
NIGHT BEFORE A BROAD AREA OF LOW PRESSURE MOVES SOUTH THU AND
FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM MONDAY EVENING THROUGH TUESDAY MORNING FOR
LSZ267.
GALE WATCH FROM MONDAY EVENING THROUGH LATE MONDAY NIGHT FOR
LSZ266.
GALE WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING FOR LSZ264.
GALE WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...MRD
AVIATION...KC
MARINE...KC/MRD
AREA FORECAST DISCUSSION
NWS GAYLORD MI
139 PM EDT SAT SEP 15 2012
.SYNOPSIS...
ISSUED AT 341 AM EDT SAT SEP 15 2012
OUTSTANDING WEATHER IS EXPECTED THIS WEEKEND AS HIGH PRESSURE SLIDES
ACROSS THE GREAT LAKES. THE NEXT COLD FRONT WILL MOVE THROUGH ON
MONDAY...BRINGING THE NEXT CHANCE OF RAIN. LAKE EFFECT RAIN SHOWERS
MAY DEVELOP TUESDAY...AS MUCH COOLER AIR INVADES THE REGION.
&&
.UPDATE...
ISSUED AT 139 PM EDT SAT SEP 15 2012
SCATTERED-BROKEN AREA OF CU/SC ACROSS MUCH OF NORTHERN LOWER AT
EARLY AFTERNOON...MOSTLY SUNNY ACROSS EASTERN UPPER AND FAR
NORTHEAST LOWER (WHILE A LITTLE COOLER ALOFT FARTHER NORTH IT IS
DRIER IN THE LOW LEVELS WITH DEW POINTS IN THE 35-40F RANGE). NO
BIG CHANGES TO THE FORECAST...JUST TWEAKS TO ACCOUNT FOR CURRENT
TRENDS.
UPDATE ISSUED AT 1052 AM EDT SAT SEP 15 2012
HIGH PRESSURE CENTERED RIGHT OVER MICHIGAN THIS MORNING. SOME
EARLY HIGHER ELEVATION FOG/STRATUS HAS BEEN THINNING...WITH
DIURNAL CU DEVELOPMENT EXPECTED BY MIDDAY. LIGHT WINDS TODAY WITH
LAKE BREEZES BEING FAIRLY UBIQUITOUS...AFTERNOON HIGHS MOSTLY IN
THE 60S/NEAR 70S ACROSS PARTS OF NORTHWEST LOWER.
UPDATE ISSUED AT 640 AM EDT SAT SEP 15 2012
BROKEN LAKE CLOUDS CONTINUE TO ROLL IN OFF LAKES MICHIGAN AND
HURON WITHIN A DRYING NORTHERLY FLOW. THESE CLOUDS ARE RATHER
THIN...AND DO NOT EXPECTED THEM TO LAST TOO MUCH AFTER SUNRISE
DUE TO MIXING INTO DRIER AIR. STILL LOOKING FOR A GOOD DEAL OF
SUNSHINE TODAY WITH LIGHT WINDS/AFTERNOON LAKE BREEZES.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 341 AM EDT SAT SEP 15 2012
SHARP UPPER TROUGH WORKING INTO NEW ENGLAND WITH A SOLID NW FLOW
ALOFT OVER NRN MICHIGAN. ATMOSPHERIC SUBSIDENCE WITH DRY AIR
ADVECTION WITHIN ADVANCING SFC HIGH PRESSURE. STILL...VERY GOOD
OVERLAKE INSTABILITY HAS LED TO THE DEVELOPMENT OF STRATO CU IN
BACKING NW-W 1000-850MB FLOW...ATTACHED TO GREEN BAY. WINDS ARE
WEAKENING WITH TIME...SO FETCH AND INLAND PENETRATION WILL
CONTINUE LEAD TO LESS CLOUD...BUT THIS MAY TAKE THROUGH EARLY
DAYBREAK...WHEN MIXING INTO DRIER AIR ALOFT CAN HELP MIX IT ALL
OUT. TEMPERATURES WERE QUITE CHILLY...DIPPING INTO THE 30S IN
SEVERAL LOCALES OF NRN LOWER. SKIES WERE FAIRLY CLEAR ACROSS
EASTERN UPPER...WITH LATEST RUC ANALYSIS SUGGESTING A WEAKER WIND
FLOW AND LESS MOISTURE FLUX OFF WHITEFISH BAY/EASTERN LAKE
SUPERIOR. CANNOT RULE OUT SOME STRATO CU INTO CHIPPEWA COUNTY
THOUGH OVER THE NEXT FEW HOURS.
TODAY AND TONIGHT...VERY QUIET. SFC HIGH PRESSURE WILL MOVE IN
OVERHEAD WITH SOME SCATTERED CUMULUS DEVELOPMENT...MAINLY ALONG
THE AXIS OF THE SFC HIGH...AND AREAS EAST. THIS BRINGS THE BETTER
CU ACROSS NE LOWER AND EASTERN CHIP/MACK. BY LATER THIS
AFTERNOON...SOME LAKE BREEZES WILL TRY TO CONSOLIDATE THIS CLOUD
MORE INLAND. THE CLOUDS WILL QUICKLY ERODE TO CLEAR SKIES IN THE
EVENING WITH ONLY SOME SCATTERED MID CLOUD POSSIBLE OVERNIGHT.
THIS WILL BE AHEAD OF A WEAK SHORTWAVE AND LOW LEVEL WARM FRONT
LIFTING OUR WAY. A 30-35KT WSW ORIENTED LLJ COULD THEORETICALLY
RESULT IN SOME THIN CLOUDINESS LATE. WOULD HEDGE MY BETS ON A
FAIRLY CLEAR EVENING THOUGH. LOW TEMPS LIKELY IN THE LOW TO MID
40S WEST/NW CWA IN BETTER SW FLOW DEVELOPING...WITH THE COLDEST
MID TO UPPER 30S IN LOW LYING AREAS OF THE EASTERN CWA OF NRN
LOWER.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 341 AM EDT SAT SEP 15 2012
HIGH PRESSURE AT THE SURFACE AND ALOFT SUNDAY IS EXPECTED TO LEAD TO
VERY PLEASANT WEATHER FOR THE LAST SUNDAY OF SUMMER (THE AUTUMNAL
EQUINOX IS EARLY SATURDAY MORNING ON SEPTEMBER 22ND). A COLD FRONT
WILL THEN MOVE ACROSS THE REGION LATER MONDAY SETTING THE STAGE FOR
LONG WAVE TROUGHING TO SETTLE INTO THE REGION FOR MUCH OF NEXT WEEK.
THIS WILL LEAD TO AN EXTENDED PERIOD OF COOLER AND UNSETTLED
WEATHER. THE MAIN LONG TERM FORECAST CONCERNS REVOLVE AROUND POPS
FOR ALL OF NEXT WEEK.
SUNDAY...SURFACE HIGH PRESSURE SHIFTS OFF TO OUR EAST WHILE UPPER
LEVEL HEIGHTS MAX/FLATTEN OUT. THIS IS EXPECTED TO LEAD TO LOTS OF
SUNSHINE AND MILD TEMPERATURES WITH HIGHS RANGING FROM THE MIDDLE
70S TO LOWER 80S.
SUNDAY NIGHT INTO MONDAY NIGHT...PARTLY CLOUDY SKIES WITH MILDER
TEMPERATURES SUNDAY NIGHT AS SOUTHWEST WINDS STAY UP A BIT. A COLD
FRONT MOVES ACROSS THE REGION LATER MONDAY LIKELY BRINGING SHOWERS.
LOWS SUNDAY NIGHT IN THE 50S WITH HIGHS ON MONDAY RANGING FROM THE
MIDDLE AND UPPER 60S NORTH TO THE MIDDLE AND UPPER 70S SOUTHEAST.
LOWS MONDAY NIGHT IN THE MIDDLE 40S TO LOWER 50S.
TUESDAY...HEIGHTS CONTINUE TO FALL AND COMBINE WITH INCREASING OVER
LAKE INSTABILITY (AS 850 MB TEMPERATURES FALL TO BETWEEN ZERO AND -2
C) AND A SHORT WAVE MOVING THROUGH THE FLOW TO PRODUCE A CHANCE OF
RAIN SHOWERS. THE MEAN FLOW APPEARS TO BE NORTH OR NORTH NORTHWEST
SO LOCALS NEAR THE LAKE SHORES WILL LIKELY HAVE THE BEST SHOT OF
RAIN. HIGHS RANGING FROM THE MUCH COOLER LOWER 50S NORTH TO AROUND
60 SOUTHEAST.
TUESDAY NIGHT...A WEDGE OF DRIER AIR IN COMBINATION WITH HIGH
PRESSURE NOSING IN FROM THE NORTH WILL SET THE STAGE FOR A VERY
CHILLY NIGHT. IF WINDS DECOUPLE...AND RIGHT NOW IT LOOKS LIKE THEY
WILL...THIS COULD LEAD TO THE FIRST SIGNIFICANT FROST OR FREEZE OF
THE SEASON.
WEDNESDAY THROUGH FRIDAY...ENERGY RIDING SOUTHEAST ON THE BACKSIDE
OF A BLOSSOMING PACIFIC RIDGE AMPLIFIES THE LONG WAVE TROUGH ACROSS
THE GREAT LAKES. SO THIS IN COMBINATION WITH PERIODIC SHORT WAVES
MOVING THROUGH THE FLOW AND INCREASING OVER LAKE INSTABILITY BRINGS
MORE CHANCES FOR RAIN SHOWERS. THE DETAILS OF WHICH WILL NEED TO BE
WORKED OUT BY FUTURE SHIFTS. HIGHS GENERALLY RANGING FROM THE MIDDLE
50S TO THE MIDDLE 60S. LOWS IN THE UPPER 30S AND 40S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 139 PM EDT SAT SEP 15 2012
VFR CONDITIONS EXPECTED THROUGH SUNDAY MORNING. AS GRADIENT
INCREASES TONIGHT SOME LOW LEVEL WIND SHEAR MAY BECOME AN ISSUE
(FOR NOW ONLY CARRIED IN TVC TERMINAL FORECAST).
&&
.MARINE...
ISSUED AT 159 AM EDT SAT SEP 15 2012
DROPPED SMALL CRAFT ADVISORY ACROSS THE NE LOWER NEARSHORE WATERS
UNDER A WEAKENING LOW LEVEL WIND FIELD...WITH SUPPORT FROM LATEST
MARINE OBS. THIS DESPITE GOOD OVERLAKE INSTABILITY...BUT GUSTY
WINDS ARE LIKELY...ESPECIALLY OVER LAKE HURON. HIGH PRESSURE WILL
THEN SETTLE INTO THE REGION TODAY FOR ONSHORE LAKE BREEZES IN THE
AFTERNOON. THIS HIGH EXITS EAST TONIGHT WITH SOUTHERLY WINDS
RETURNING. THERE IS AN OUTSIDE CHANCE AT SOME LOW END ADVISORY
LEVEL WINDS IN COASTAL CONVERGENCE REGIONS FROM MANISTEE THROUGH
THE MANITOU ISLANDS. CONFIDENCE IS LOW AT THIS POINT...ESPECIALLY
WITH LOW LEVEL WARMING AND INCREASING STABILITY. THESE SAME
ADVISORY POSSIBILITIES CONTINUE THROUGH SUNDAY NIGHT IN ADVANCE OF
THE NEXT LOW PRESSURE AND COLD FRONT WHICH PASSES MONDAY.
INSTABILITY OVER THE LAKES INCREASES RELATIVELY SUBSTANTIALLY
BEHIND THIS FRONT FOR WHAT COULD VERY WELL TURN OUT TO BE THE
BETTER CHANCES FOR ADVISORIES. UNSTABLE CONDITIONS ARE EXPECTED TO
HOLD FROM MONDAY NIGHT ALL THE WAY THROUGH NEXT WORK WEEK AND
POSSIBLY NEXT WEEKEND.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JPB
SYNOPSIS...AJS
SHORT TERM...SMD
LONG TERM...AJS
AVIATION...JPB
MARINE...SMD
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
1200 PM MDT SAT SEP 15 2012
.DISCUSSION...
UPDATE FORTHCOMING. HAVE ADJUSTED POPS AND WEATHER GRIDS ALONG THE
HI-LINE THIS MORNING. BOTH THE GFS AND EUROPEAN MODELS DEVELOP A
LITTLE QPF ACROSS THE HI-LINE AS WEAK SHORTWAVE ENERGY PROPAGATES
EASTWARD WITHIN THE FLOW ALOFT. HRRR ANALYSIS ALSO HINTS AT A FEW
WEAK RETURNS DURING THE MORNING HOURS. LITTLE...IF
ANY...ACCUMULATION EXPECTED. REMAINDER OF FORECAST LOOKS ON TRACK.
EMANUEL
&&
.AVIATION...
UPDATED 1800Z.
EXPECT VFR CONDITIONS WITH THE EXCEPTION OF LOCAL MVFR VISIBILITIES
IN SMOKE OVER SOUTHWEST MONTANA. A WEAK COLD FRONT MOVING SOUTH THIS
MORNING SHIFTED WINDS TO THE NORTH. CEILINGS SHOULD GENERALLY BE AT
OR ABOVE 12000 FT INTO TONIGHT. A FEW SHOWERS WILL DEVELOP IN THE
NORTH AFTER MIDNIGHT AND COULD SEE CEILINGS LOWER TO NEAR 5000 FT
NEAR ANY SHOWERS. TERMINALS AT KHVR AND KLWT MAY SEE SOME MORNING
SHOWERS SUNDAY BEFORE SKIES CLEAR IN THE AFTERNOON.
&&
.PREV DISCUSSION...ISSUED 326 AM MDT SAT SEP 15 2012
SATURDAY THROUGH MONDAY...
WINDS WILL AGAIN DEVELOP TODAY AS A COLD FRONT APPROACHES AND
EVENTUALLY MOVES ACROSS THE AREA. MODELS STILL VARY ON TIMING OF
THE FRONT ACROSS THE AREA...HOWEVER IT SHOULD MOVE ACROSS MOST OF
CENTRAL AND NORTH CENTRAL MONTANA TO LIMIT MAXIMUM TEMPERATURES
TODAY INTO THE UPPER 70S AND LOW 80S. WINDS WILL BE BREEZY AT
TIMES...HOWEVER THE STRONGEST WINDS ARE NOT EXPECTED TO
COINCIDE WITH THE LOWEST RH VALUES AND FIRE WEATHER HIGHLITES ARE
NOT EXPECTED AT THIS TIME. WIDESPREAD PRECIPITATION IS NOT
EXPECTED WITH THIS FRONTAL PASSAGE OR THE NORTHWEST FLOW BEHIND IT
WITH THE BEST CHANCE OF SHOWERS SUNDAY. ANY SHOWERS THAT DO DEVELOP
THIS WEEKEND WILL BE LIGHT ISOLATED AND SHORT LIVED. TEMPERATURES
WILL COOL DOWN SUNDAY WITH MAXIMUM TEMPERATURES STRUGGLING TO REACH
INTO THE 70S. LOWS MONDAY MORNING WILL BE APPROACHING FREEZING AT
MANY LOCATIONS ACROSS THE AREA...HOWEVER BY MONDAY HIGH TEMPERATURES
WILL BE CLIMBING INTO THE 70S AGAIN AS THE COLD AIR MASS STARTS TO
TRANSITION EASTWARD. SUK
MONDAY NIGHT THROUGH SATURDAY...MODELS ARE IN AGREEMENT IN
FORECASTING A NORTHWEST FLOW ALOFT THROUGH THE PERIOD AS A STRONG
RIDGE ALOFT BECOMES ESTABLISHED FROM THE WEST COAST STATES TO
WESTERN CANADA. ALTHOUGH THERE WILL OCCASIONALLY BE WEAK WEATHER
DISTURBANCES EMBEDDED IN THIS FLOW..NOT ONLY DO NOT SEE ANY THREAT
FOR PRECIPITATION DO NOT EXPECT MUCH IN THE WAY OF CLOUDINESS. HIGH
TEMPERATURES SHOULD BE RELATIVELY STABLE RANGING FROM THE MID 70S TO
LOWER 80S THROUGH THE PERIOD. GUSTY WEST TO NORTHWEST WINDS MIGHT
AFFECT THE PLAINS ON TUESDAY AS A COLD FRONT MOVES THROUGH THE AREA.
BLANK
&&
.FIRE WEATHER...RELATIVE HUMIDITIES WILL ONCE AGAIN DROP INTO THE
TEENS AND SINGLE DIGITS SATURDAY BUT THE WINDS WILL NOT BE AS
STRONG...BREEZY WINDS WILL BE POSSIBLE ALONG THE HILINE.
A COLD FRONT IS EXPECTED TO MOVE THROUGH THE FORECAST AREA TUESDAY.
GUSTY WEST WINDS COULD DEVELOP AHEAD OF THE COLD FRONT THEN BECOME
GUSTY OUT OF THE NORTHWEST BEHIND THE FRONT. THESE WINDS COMBINED
WITH EXPECTED LOW RELATIVE HUMIDITIES COULD CREATE CRITICAL FIRE
WEATHER CONDITIONS. NO SHOWERS OR THUNDERSTORMS ARE EXPECTED WITH
THIS FRONT.
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 80 47 66 39 / 0 10 0 0
CTB 73 42 64 33 / 0 20 10 0
HLN 82 49 71 39 / 0 0 10 0
BZN 83 41 72 32 / 0 10 20 10
WEY 74 30 67 23 / 10 10 20 10
DLN 82 41 71 35 / 10 10 10 10
HVR 82 46 67 35 / 0 20 20 0
LWT 81 44 62 35 / 0 10 10 10
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
WEATHER.GOV/GREATFALLS
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
209 PM EDT SAT SEP 15 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL MOVE SOUTH OF THE REGION TODAY. HIGH
PRESSURE WILL BUILD OVER THE AREA TONIGHT INTO SUNDAY THEN MOVE
OFFSHORE SUNDAY NIGHT. LOW PRESSURE WILL MOVE NORTH FROM THE GULF
COAST REGION MONDAY AND ACROSS WESTERN NORTH CAROLINA MONDAY
NIGHT. A COLD FRONT WILL MOVE ACROSS THE REGION TUESDAY NIGHT
FOLLOWED BY HIGH PRESSURE BUILDING IN FROM THE NORTHWEST LATE
WEDNESDAY INTO FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1 PM SATURDAY...LATEST RAP MODEL RUNS CONTINUE TO INDICATE
THAT THE REMAINDER OF THE DAY WILL BE DRY. NAM DOES SHOW SOME
LIGHT QPF MOVING FROM NORTH TO SOUTH ACROSS THE PAMLICO
SOUND...BUT LITTLE EVIDENCE IN SATELLITE OF THAT AT THIS TIME AND
WILL LEAVE OUT OF FORECAST. NO MAJOR CHANGES AT THIS TIME.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
AS OF 215 AM SATURDAY...HIGH PRES WILL BUILD IN FROM THE N WITH
DRY WX EXPECTED. AS WINDS GO LIGHT INLAND WILL AGAIN HAVE THE
THREAT FOR SOME PATCHY FOG LATE. LOWS WILL RANGE FROM THE UPR 50S
COOLER INLAND SPOTS TO MID/UPR 60S BEACHES.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 315 AM SAT...MODELS ARE ALL IN GENERAL GOOD AGREEMENT
THROUGH THE PERIOD UNTIL MID WEEK WHEN THERE ARE MINOR TIMING
DIFFERENCES WITH THE COLD FRONT PUSHING OFF THE COAST ON WED.
GENERALLY FOLLOWED A BLEND OF MODEL GUIDANCE FOR MAJOR FEATURES.
FOLLOWED CLOSE TO MOS BIAS CORRECTED GUIDANCE FOR TEMPS THROUGH
THE PERIOD...WHICH WILL BE PRETTY CLOSE TO CLIMATOLOGY VALUES. MAD
ONLY MINOT POP ADJUSTMENTS THROUGH THE PERIOD. GENERALLY JUST A
SLIGHT CHANCE OF A SHOWER THROUGH SUNDAY INTO SUNDAY NIGHT...WITH
A GRADUAL INCREASE IN POPS ON MONDAY. THE BEST CHANCE OF SHOWERS
AND THUNDERSTORMS WILL COME ON TUESDAY AHEAD OF THE APPROACHING
COLD FRONT. COULD SEE SOME STRONG THUNDERSTORMS BUT CONFIDENCE IN
TIMING AND INSTABILITY IS TOO LOW AT THIS POINT TO GIVE E
DEFINITIVE CHANCE OF SEVERE STORMS. THE ECMWF DRIES THINGS OUT
DEFINITIVELY ON WEDNESDAY...BUT GFS IS A BIT SLOWER TO CLEAR
THINGS OUT COMPLETELY ALONG THE COAST...THEREFORE CONTINUED TO
CARRY SLIGHT CHANCE POPS THROUGH THE DAY WEDNESDAY BEFORE DRYING
THINGS OUT THURSDAY AND FRIDAY.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
SHORT TERM /THROUGH TONIGHT/...
AS OF 2 PM SATURDAY...VFR CONDITIONS ARE EXPECTED FOR ALL TAF SITES
UNTIL LATE TONIGHT. AS HIGH PRESSURE CONTINUES TO BUILD IN FROM
THE NW AND WITH WINDS EXPECTED TO DECOUPLE...THERE IS A GOOD
CHANCE OF FOG FORMATION AFTER 6Z. MOS GUIDANCE HAS INDICATED LIFR
TO VLIFR CONDITIONS...BUT FOR NOW WILL BE CONSERVATIVE TO FORECAST
LIFR CONDITIONS TO ALL TAF SITES. WOULD NOT BE A SURPRISE IF CONDITIONS
DROP EVEN LOWER. ANY FOG FORMATION THAT DEVELOPS...WILL START TO
LIFT OUT BY 12Z.
LONG TERM /SUNDAY THROUGH WED/...
AS OF 2 PM SAT...VFR CONDITIONS WILL CONTINUE FOR SUNDAY ALTHOUGH
CAN`T RULE OUT A STRAY SHOWER SUNDAY NIGHT. AS LOW PRESSURE SYS
APPROACHES TE AREA...THERE IS AN INCREASE CHANCE OF SCATTERED SHOWERS FOR
MONDAY...SO MVFR CONDITIONS CAN BE EXPECTED. BY TUESDAY MORE
WIDESPREAD SHOWERS AND TSTMS WILL MOVE INTO THE AREA AHEAD OF A
COLD FRONT. MVFR CONDITIONS WILL BE PREDOMINATE WITH PERIODS OF
IFR POSSIBLE OCCASIONALLY. CONDITIONS SHOULD BEGIN TO IMPROVE
BEHIND THE FRONT ON WEDNESDAY.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1 PM SATURDAY...A BIT OF AN UPTICK IN WIND SPEEDS OVER THE
NORTHERN WATERS WITH DUCK GUSTING TO 23 KNOTS AND OREGON INLET TO
19 KNOTS...SO HAVE INCREASED WINDS A HAIR IN THESE MARINE ZONES.
OTHERWISE...NW/NNW WINDS OF 10 TO 15 KNOTS ARE EXPECTED THROUGH
THIS AFTERNOON WITH SEAS OF 2 TO 4 FEET BUILDING TO 3 TO 5 FEET
LATE. OF INTEREST WILL BE DEVELOPMENT OF LONG PERIOD SWELLS BY
THIS EVENING. CURRENT OBSERVATIONS STILL SHOWING ABOUT 8 SECOND
PERIODS...BUT THESE ARE FORECAST TO INCREASE TO 15 SECONDS OR
GREATER BY EVENING. THIS WILL LEAD TO ROUGH SURF AND AN INCREASED
THREAT OF RIP CURRENTS. N TO NE WINDS WILL CONT AT MAINLY 10 TO 15
KTS TONIGHT AS HIGH PRES BUILDS IN FROM THE N...COULD BE SOME
GUSTS TO 20 KT EARLY ESPCLY CNTRL AND NRN WTRS.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 315 AM SAT...AS MENTIONED IN LONG TERM DISCUSSION NO
SIGNIFICANT MODEL DIFFERENCES THROUGH THE PERIOD. THERE IS JUST A
MINOR TIMING DIFFERENCE WITH THE COLD FRONT MOVING THROUGH THE
REGION WEDNESDAY. FOLLOWED A BLEND OF GFS/ECMWF FOR WINDS IN THAT
TIME PERIOD. EARLY IN THE PERIOD SCA CONDITIONS DUE MAINLY TO THE
LONG PERIOD SWELL WILL BEGIN TO DIMINISH. SEAS WILL FALL BELOW SCA
CONDITIONS ALL WATERS BY LATE SUNDAY AFTERNOON. THE LULL IN CALM
CONDITIONS WILL BE SHORT ON MONDAY AS WINDS BECOME SOUTHERLY INCREASE
TO 20 TO 25 KT AHEAD OF THE APPROACHING COLD FRONT ON
TUESDAY...WITH SEAS BUILDING TO 6 TO 7 FEET ACROSS A LARGE PORTION
OF THE WATERS. THE COLD FRONT SHOULD PASS THROUGH THE WATERS
WEDNESDAY WITH SEAS SUBSIDING.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...BEACH HAZARDS STATEMENT UNTIL 8 PM EDT THIS EVENING FOR NCZ103.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 6 PM EDT
SUNDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 1 PM EDT
SUNDAY FOR AMZ150-156-158.
&&
$$
SYNOPSIS...RF
NEAR TERM...CTC
SHORT TERM...RF
LONG TERM...RSB
AVIATION...BM/RSB
MARINE...RSB/CTC/RF
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
105 PM EDT SAT SEP 15 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL DRIFT SOUTH TODAY AND DISSIPATE OVER THE AREA
SUNDAY. LOW PRESSURE DEVELOPING ALONG THE GULF COAST MONDAY WILL
MOVE THROUGH THE WESTERN CAROLINAS TUESDAY...BRINGING PERIODS OF
SHOWERS AND THUNDERSTORMS TO THE AREA...WITH LOCALLY HEAVY RAIN
POSSIBLE. A COLD FRONT WILL CROSS THE AREA EARLY WEDNESDAY...WITH
HIGH PRESSURE BUILDING IN BEHIND IT CREATING COOLER AND DRIER
WEATHER FOR THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM SATURDAY...ADJUSTED SHOWER CHANCES DOWN JUST A TAD
FROM NOW THROUGH 6 PM. ALTHOUGH THE CUMULUS FIELD IS AS EXPANSIVE AS
THOUGHT...THE VERTICAL EXTENT OF THE CUMULUS IS NOT AS GREAT AS
EXPECTED. THIS MAY CHANGE WITH ADDITIONAL HEATING THROUGH THE
AFTERNOON BUT LATEST MESOSCALE MODELS CONTINUE TO SHOW LITTLE
CONVECTIVE PRECIPITATION THROUGH THE AFTERNOON. PREVIOUS DISCUSSION
FROM 1000 AM FOLLOWS...
FOG HAS LIFTED ACROSS THE EASTERN CAROLINAS BUT STUBBORN LOW CLOUDS
IN THE SC PEE DEE REGION MAY TAKE ANOTHER 30 MINUTES OR SO TO BURN
OFF. MOSTLY SUNNY SKIES LATE THIS MORNING WILL TURN PARTLY CLOUDY
ACROSS MOST OF OUR AREA THIS AFTERNOON AS FAIRLY STEEP LOW-LEVEL
LAPSE RATES AND GOOD MOISTURE CONTENT BELOW 850 MB HELP PRODUCE A
CUMULUS CLOUD FIELD. THE 12Z CHS SOUNDING SHOWED THE 06Z GFS AND NAM
MODELS WERE BOTH 5 DEGREES F TOO DRY WITH DEWPOINTS FROM THE SURFACE
UP THROUGH 850 MB. THIS ADDITIONAL MOISTURE SHOULD HELP ENHANCE THE
AFTERNOON CUMULUS.
THE BIGGEST QUESTION MARK WITH TODAY`S FORECAST IS THE POTENTIAL OF
AFTERNOON AND EVENING SHOWERS. THE 06Z GFS AND NAM MODELS PRODUCE
SOME ISOLATED SHOWERS BUT THE ASSOCIATED STATISTICAL OUTPUT SHOWS
ONLY 0-10 PERCENT POPS. THE PAST SEVERAL HRRR RUNS ALSO SHOW DRY
WEATHER THROUGH THIS EVENING. GIVEN FAIRLY MOIST LOW-LEVELS AND
STEEP LAPSE RATES UP THROUGH AN INVERSION AT 10-11 KFT I EXPECT AT
LEAST SOME ISOLATED SHOWERS MUCH LIKE EXPERIENCED YESTERDAY. THE
SEABREEZE BOUNDARY...PARTICULARLY IN SE NORTH CAROLINA WHERE NATURAL
CONVERGENCE IS PRODUCED BY THE SEABREEZE...IS AN OBVIOUSLY TRIGGER.
A SECOND POSSIBLE TRIGGER IS THE ARRIVAL OF A DYING COLD FRONT FROM
THE NORTH LATE THIS AFTERNOON...ALTHOUGH CONVERGENCE IS WEAKENING
WITH THIS FEATURE GIVEN THE INCREASINGLY SIMILAR WIND DIRECTIONS ON
EITHER SIDE. IN ANY CASE WE`LL KEEP POPS NO HIGHER THAN 25% THROUGH
THIS EVENING.
HIGHS TODAY SHOULD REACH THE MID 80S AWAY FROM THE OCEAN...WITH
HIGHS AROUND 80 ON THE BEACHES. MORNING LOW CLOUDS AND FOG SHOULD
HAVE NO IMPACT ON THESE TEMPERATURES.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...SHORT TERM WILL FEATURE A TRANSITIONAL
PERIOD AS SPLIT FLOW 500MB PATTERN TRANSITIONS TO A HIGHLY AMPLIFIED
TROUGH ACROSS THE EASTERN HALF OF THE COUNTRY. HIGH PRESSURE
DRIFTING ACROSS THE MID ATLANTIC SUNDAY WILL ALLOW WINDS TO TURN
GRADUALLY FROM NE TO SE THROUGH THE DAY. THIS OCCURS AT THE SAME
TIME THAT A 60KT 300MB JET MAX MOVES ACROSS NC. EVEN THOUGH FORECAST
SOUNDINGS REMAIN RELATIVELY DRY ABOVE 850MB...THE INCREASING
MOISTURE ON SE FLOW COMBINED WITH THE SUBTLE UPPER SUPPORT COULD
SPAWN AN ISOLATED SHOWER/TSTM DURING THE AFTN...AND WILL KEEP
INHERITED SCHC POP. TEMPS SUNDAY WILL BE RIGHT AROUND CLIMO...LOW TO
MID 80S MOST LOCATIONS. MINS WILL FALL TO RIGHT AROUND CLIMO SUNDAY
NIGHT...MID 60S.
SOUTHERN STREAM VORT MAX WILL GET STRUNG OUT AND LIFT NORTHEAST AS A
DEEP 500MB TROUGH DIGS ACROSS THE CENTRAL PLAINS. WAVE OF LOW
PRESSURE DEVELOPS BENEATH THIS UPPER VORT AND SLIDES NORTHEAST
TOWARDS THE AREA...PUSHING A WARM FRONT ACROSS THE CAROLINAS DURING
MONDAY. AS THIS OCCURS...FLOW WITHIN THE COLUMN TURNS TO BECOME DEEP
SOUTHEASTERLY...ADVECTING SIGNIFICANTLY INCREASED MOISTURE INTO THE
CAROLINAS. ALTHOUGH BEST RAIN CHANCES WILL HOLD OFF UNTIL MONDAY
NIGHT...WILL SHOW INCREASING POP THROUGH THE DAY FROM SOUTH TO
NORTH. WITH PWATS RISING TO NEARLY TWO INCHES MONDAY NIGHT...AND
FORCING INCREASING LATE...EXPECT A PERIOD OF MDT/HEAVY RAINFALL
DEVELOPING AT THE END OF THE PERIOD...AND WILL BUMP ALL LOCATIONS TO
LIKELY POP. TEMPS WILL BE TEMPERED BY CLOUDS/RAIN...REMAINING IN THE
LOW 80S. INCREASED SOUTHERLY FLOW AND RAIN WILL KEEP MINS WELL ABOVE
CLIMO...ONLY FALLING TO AROUND 70.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3 AM SATURDAY...A VERY WET TUESDAY EXPECTED BEFORE DRIER AND
COOLER WEATHER DEVELOPS FOR THE LATTER HALF OF THE UPCOMING WEEK.
INGREDIENTS APPEAR TO BE COMING TOGETHER TO SUPPORT A VERY WET
TUESDAY WITH MODERATE/HEAVY RAINFALL LIKELY ACROSS THE ENTIRE CWA.
SOUTHERN STREAM VORT MAX BEGINS TO PHASE WITH NORTHERN STREAM ENERGY
JUST WEST OF THE CWA. AS THIS OCCURS...SURFACE LOW WORKS UP ALONG
THE APPALACHIANS ACROSS THE WESTERN CAROLINAS. THE KEEPS THE CWA IN
DEEP SOUTHERLY FLOW WHICH ADVECTS A STRONG THETA-E RIDGE INTO THE
AREA. PWATS RISE TO NEARLY 2.25 INCHES...OR 2-3 SD`S ABOVE NORMAL
FOR MID-SEPTEMBER. AT THE SAME TIME...WE ENTER THE RIGHT DIFFLUENT
PORTION OF AN 80-90KT 300MB JET AND 850MB TRANSPORT WINDS APPROACH
40-50 KTS. THIS ALL POINTS TOWARDS PERIODS OF HEAVY RAINFALL...AND
HPC IS PAINTING 1-1.5" OF QPF ACROSS THIS AREA. WITH SUCH STRONG LOW
LEVEL WINDS IN PLACE...COULD BE CONCERNED ABOUT A SEVERE WIND
POTENTIAL...HOWEVER...LACK OF INSOLATION KEEPS ML LAPSE RATES BELOW
6C/KM...SO HEAVY RAIN EXPECTED TO BE THE PRIMARY THREAT. RAIN WILL
CONTINUE THROUGH TUESDAY NIGHT BEFORE LOW MOVES OFF TO THE NORTHEAST
AND ITS ASSOCIATED COLD FRONT DRAGS THROUGH BY EARLY WEDNESDAY.
BEHIND THIS FRONT...COOLER AND DRIER WEATHER EXPECTED THROUGH THE
REST OF THE EXTENDED. HIGH PRESSURE BUILDS DOWN THE COAST AS 500MB
TROUGH RELOADS ACROSS THE MIDWEST. THIS WILL BRING COOL E/NE LOW
LEVEL FLOW...BUT ALSO MOSTLY SUNNY AND DRY CONDITIONS TO FINISH THE
WEEK.
TEMPS TUESDAY WILL BE AROUND CLIMO WITH CLOUDS AND RAIN...FALLING TO
BELOW CLIMO FOR THE REST OF THE WEEK BEHIND THE COLD FRONT. MINS
TUESDAY NIGHT WILL BE ABOVE CLIMO...BEFORE FALLING TO NEAR NORMAL
WED-FRI.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 18Z...VFR CONDITIONS THROUGH THE EVENING HOURS WITH SCATTERED
CUMULUS. A STRAY SHOWER IS POSSIBLE ALONG THE SEA BREEZE BOUNDARY...
BUT WILL BE VERY ISOLATED IN NATURE NOT WARRANTING A VCSH MENTION.
TONIGHT...MOISTURE WILL POOL ALONG THE STALLING FRONTAL BOUNDARY.
THINK MID AND HIGH CLOUDS WILL STILL BE SCATTERED ENOUGH TO SUPPORT
RADIATIONAL COOLING WITH FOG/STRATUS AFTER 09Z. SUNDAY MORNING...
MOISTURE CONTINUES TO BE ON THE INCREASE WITH SOME ISENTROPIC LIFT
DEVELOPING...PARTICULARLY IN THE LBT VICINITY. SCATTERED
SHOWERS/T-STORMS ARE POSSIBLE SUNDAY AFTERNOON.
THE EXTENDED OUTLOOK...MOISTURE WILL CONTINUE TO BE ON THE INCREASE
WITH SCATTERED CONVECTION SUNDAY EVENING THROUGH MONDAY...BECOMING
NUMEROUS ON TUESDAY WITH MODERATE CONFIDENCE FOR INTERMITTENT IFR
CONDITIONS. BECOMING VFR WEDNESDAY THROUGH THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM SATURDAY...NO CHANGES TO THE FORECAST ARE NEEDED. THE
SEABREEZE IS JUST NOW BEGINNING TO SHOW UP IN MESONET WIND
OBSERVATIONS AT THE BEACHES. PREVIOUS DISCUSSION FROM 1000 AM
FOLLOWS...
A SURFACE COLD FRONT OVER NORTHERN NORTH CAROLINA WILL MOVE SOUTH TO
CAPE FEAR LATE THIS AFTERNOON. WINDS ON BOTH SIDES OF THE BOUNDARY
ARE NORTHERLY SO THE FEATURE IS CERTAINLY LOSING ITS DEFINITION AS
IT MOVES SOUTH. UNLESS THERE IS A LINE OF CLOUDS OR SHOWERS
ACCOMPANYING THE FRONT...THE ONLY IMPACT MARINERS SHOULD NOTE AS THE
FRONT REACHES US IS A VEERING OF THE WIND DIRECTION A LITTLE MORE
EASTERLY. OTHERWISE NORTH-NORTHEASTERLY WINDS AROUND 10 KT WILL
CONTINUE THROUGH THE DAY...TURNING EAST TO EVEN SOUTHEAST ALONG THE
IMMEDIATE COAST AS A WEAK SEABREEZE DEVELOPS. SEA HEIGHTS AT THE
BUOYS ARE 3-4 FT LIKE YESTERDAY...BUT SPECTRAL WAVE DATA LOOKS VERY
DIFFERENT THAN YESTERDAY WITH VERY LITTLE SHORT PERIOD WAVE ENERGY
PRESENT. THE DOMINANT PERIOD IS NOW 9-10 SECONDS IN AN EASTERLY
SWELL THAT SHOULD PERSIST THROUGH TONIGHT.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...HIGH PRESSURE DRIFTING ACROSS THE
MID-ATLANTIC STATES WILL KEEP WINDS LIGHT SUNDAY...AS THEY VEER
SLOWLY FROM THE NE EARLY...TO SE BY NIGHT. SEAS SUNDAY WILL FALL
SLOWLY THROUGH THE DAY...FROM 3-4 FT EARLY TO 2-4 FT LATE...FORMED
BY A COMBINATION OF AN EASTERLY WIND WAVE AND A 2-3 FT/12SEC SE
SWELL FROM HURRICANE NADINE. CONDITIONS ACROSS THE WATERS WILL
DETERIORATE MONDAY AS A STORM SYSTEM PASSES WEST OF THE AREA. A
WARM FRONT WILL CROSS THE WATERS DURING MONDAY...TURNING WINDS TO
THE SOUTH...WHICH WILL THEN INCREASE DRAMATICALLY MONDAY NIGHT.
WINDS LESS THAN 10 KTS EARLY MONDAY WILL RISE UP TO 15-20 KTS
MONDAY NIGHT. ALTHOUGH THE LONG PERIOD SWELL WILL DECAY AS
HURRICANE NADINE PULLS AWAY...THIS INCREASING WIND WILL FORCE
STEEPER WAVES...AND SEAS WILL BUILD TO 3-5 FT BY THE END OF THE
PERIOD...WITH ISOLATED 6 FTERS POSSIBLE. AT THIS TIME IT APPEARS A
SCEC WILL BE NEEDED MONDAY NIGHT...WITH AN SCA POSSIBLE.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3 AM SATURDAY...STRONG SOUTHERLY WINDS TUESDAY CREATE
HAZARDOUS CONDITIONS ACROSS THE COASTAL WATERS...WITH A SMALL CRAFT
ADVISORY LIKELY NEEDED MUCH OF THE DAY. SOUTHERLY WINDS AHEAD OF A
COLD FRONT WILL BE 15-20 KTS...POSSIBLY HIGHER...AND HELP BUILD SEAS
TO 4-6 FT. THESE WAVES WILL BE QUITE STEEP AS WELL...WITH A DOMINANT
PERIOD OF 5-6 SECONDS. VERY LATE TUESDAY NIGHT THE COLD FRONT WILL
CROSS THE WATERS...TURNING WINDS TO THE NW...THEN NE ON WEDNESDAY
WHILE SPEEDS DECREASE TO 10-15 KTS. SEAS FALL QUICKLY...BECOMING 2-3
FT THROUGH MUCH OF WEDNESDAY...ALTHOUGH A CONFUSED SEA STATE IS
LIKELY EARLY WEDNESDAY DUE TO SEVERAL DIFFERENT WAVE GROUPS PRESENT
IN THE SPECTRUM.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...TRA
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...43/TRA
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
104 PM EDT SAT SEP 15 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL MOVE SOUTH OF THE REGION TODAY. HIGH
PRESSURE WILL BUILD OVER THE AREA TONIGHT INTO SUNDAY THEN MOVE
OFFSHORE SUNDAY NIGHT. LOW PRESSURE WILL MOVE NORTH FROM THE GULF
COAST REGION MONDAY AND ACROSS WESTERN NORTH CAROLINA MONDAY
NIGHT. A COLD FRONT WILL MOVE ACROSS THE REGION TUESDAY NIGHT
FOLLOWED BY HIGH PRESSURE BUILDING IN FROM THE NORTHWEST LATE
WEDNESDAY INTO FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1 PM SATURDAY...LATEST RAP MODEL RUNS CONTINUE TO INDICATE
THAT THE REMAINDER OF THE DAY WILL BE DRY. NAM DOES SHOW SOME
LIGHT QPF MOVING FROM NORTH TO SOUTH ACROSS THE PAMLICO
SOUND...BUT LITTLE EVIDENCE IN SATELLITE OF THAT AT THIS TIME AND
WILL LEAVE OUT OF FORECAST. NO MAJOR CHANGES AT THIS TIME.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
AS OF 215 AM SATURDAY...HIGH PRES WILL BUILD IN FROM THE N WITH
DRY WX EXPECTED. AS WINDS GO LIGHT INLAND WILL AGAIN HAVE THE
THREAT FOR SOME PATCHY FOG LATE. LOWS WILL RANGE FROM THE UPR 50S
COOLER INLAND SPOTS TO MID/UPR 60S BEACHES.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 315 AM SAT...MODELS ARE ALL IN GENERAL GOOD AGREEMENT
THROUGH THE PERIOD UNTIL MID WEEK WHEN THERE ARE MINOR TIMING
DIFFERENCES WITH THE COLD FRONT PUSHING OFF THE COAST ON WED.
GENERALLY FOLLOWED A BLEND OF MODEL GUIDANCE FOR MAJOR FEATURES.
FOLLOWED CLOSE TO MOS BIAS CORRECTED GUIDANCE FOR TEMPS THROUGH
THE PERIOD...WHICH WILL BE PRETTY CLOSE TO CLIMATOLOGY VALUES. MAD
ONLY MINOT POP ADJUSTMENTS THROUGH THE PERIOD. GENERALLY JUST A
SLIGHT CHANCE OF A SHOWER THROUGH SUNDAY INTO SUNDAY NIGHT...WITH
A GRADUAL INCREASE IN POPS ON MONDAY. THE BEST CHANCE OF SHOWERS
AND THUNDERSTORMS WILL COME ON TUESDAY AHEAD OF THE APPROACHING
COLD FRONT. COULD SEE SOME STRONG THUNDERSTORMS BUT CONFIDENCE IN
TIMING AND INSTABILITY IS TOO LOW AT THIS POINT TO GIVE E
DEFINITIVE CHANCE OF SEVERE STORMS. THE ECMWF DRIES THINGS OUT
DEFINITIVELY ON WEDNESDAY...BUT GFS IS A BIT SLOWER TO CLEAR
THINGS OUT COMPLETELY ALONG THE COAST...THEREFORE CONTINUED TO
CARRY SLIGHT CHANCE POPS THROUGH THE DAY WEDNESDAY BEFORE DRYING
THINGS OUT THURSDAY AND FRIDAY.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
SHORT TERM /THROUGH TONIGHT/...
AS OF 615 AM SATURDAY...WIDESPREAD LIFR IN FOG/ST EARLY THIS
MORN. CONDITIONS SHLD BEGIN TO IMPROVE AROUND 12Z AS WEAK COLD
FRONT DROPS INTO REGION AND MIXING STARTS. ONCE FOG LIFTS EXPECT
VFR REST OF THE DAY WITH POSS SOME ISOLD SHRA NEAR CST LATE. AS
HIGH PRES BUILDS IN FROM THE N TONIGHT WILL AGAIN HAVE THE THREAT
FOR SOME PATCHY FOG AND IFR CONDITIONS AT TIMES MAINLY AFT 08Z.
LONG TERM /SUNDAY THROUGH WED/...
AS OF 315 AM SAT...VFR CONDITIONS PREVAIL THROUGH SUNDAY INTO
SUNDAY NIGHT ALTHOUGH CAN`T RULE OUT A STRAY SHOWER SUNDAY NIGHT.
THE CHANCE FOR SCATTERED SHOWERS WILL INCREASE INTO MONDAY AND
MONDAY NIGHT...BUT WOULD EXPECT MOSTLY MVFR CONDITIONS. BY TUESDAY
MORE WIDESPREAD SHOWERS AND TSTMS WILL MOVE INTO THE AREA AHEAD OF
A COLD FRONT. MVFR CONDITIONS WILL BE PREDOMINATE WITH PERIODS OF
IFR POSSIBLE OCCASIONALLY. CONDITIONS SHOULD BEGIN TO IMPROVE
BEHIND THE FRONT ON WEDNESDAY.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1 PM SATURDAY...A BIT OF AN UPTICK IN WIND SPEEDS OVER THE
NORTHERN WATERS WITH DUCK GUSTING TO 23 KNOTS AND OREGON INLET TO
19 KNOTS...SO HAVE INCREASED WINDS A HAIR IN THESE MARINE ZONES.
OTHERWISE...NW/NNW WINDS OF 10 TO 15 KNOTS ARE EXPECTED THROUGH
THIS AFTERNOON WITH SEAS OF 2 TO 4 FEET BUILDING TO 3 TO 5 FEET
LATE. OF INTEREST WILL BE DEVELOPMENT OF LONG PERIOD SWELLS BY
THIS EVENING. CURRENT OBSERVATIONS STILL SHOWING ABOUT 8 SECOND
PERIODS...BUT THESE ARE FORECAST TO INCREASE TO 15 SECONDS OR
GREATER BY EVENING. THIS WILL LEAD TO ROUGH SURF AND AN INCREASED
THREAT OF RIP CURRENTS. N TO NE WINDS WILL CONT AT MAINLY 10 TO 15
KTS TONIGHT AS HIGH PRES BUILDS IN FROM THE N...COULD BE SOME
GUSTS TO 20 KT EARLY ESPCLY CNTRL AND NRN WTRS.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 315 AM SAT...AS MENTIONED IN LONG TERM DISCUSSION NO
SIGNIFICANT MODEL DIFFERENCES THROUGH THE PERIOD. THERE IS JUST A
MINOR TIMING DIFFERENCE WITH THE COLD FRONT MOVING THROUGH THE
REGION WEDNESDAY. FOLLOWED A BLEND OF GFS/ECMWF FOR WINDS IN THAT
TIME PERIOD. EARLY IN THE PERIOD SCA CONDITIONS DUE MAINLY TO THE
LONG PERIOD SWELL WILL BEGIN TO DIMINISH. SEAS WILL FALL BELOW SCA
CONDITIONS ALL WATERS BY LATE SUNDAY AFTERNOON. THE LULL IN CALM
CONDITIONS WILL BE SHORT ON MONDAY AS WINDS BECOME SOUTHERLY INCREASE
TO 20 TO 25 KT AHEAD OF THE APPROACHING COLD FRONT ON
TUESDAY...WITH SEAS BUILDING TO 6 TO 7 FEET ACROSS A LARGE PORTION
OF THE WATERS. THE COLD FRONT SHOULD PASS THROUGH THE WATERS
WEDNESDAY WITH SEAS SUBSIDING.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...BEACH HAZARDS STATEMENT UNTIL 8 PM EDT THIS EVENING FOR NCZ103.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 6 PM EDT
SUNDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 1 PM EDT
SUNDAY FOR AMZ150-156-158.
&&
$$
SYNOPSIS...RF
NEAR TERM...CTC
SHORT TERM...RF
LONG TERM...RSB
AVIATION...RSB/RF
MARINE...RSB/CTC/RF
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
153 PM EDT SAT SEP 15 2012
.SYNOPSIS...
WEAK HIGH PRESSURE DRIFTS SLOWLY EAST REACHING THE COAST BY SUNDAY.
A STRONG LOW PRESSURE SYSTEM OFF THE GULF COAST WILL TRACK NORTHEAST
ACROSS EASTERN TENNESSEE BEFORE MEETING UP WITH A COLD FRONT MOVING
IN FROM THE WEST LATE TUESDAY. DRY HIGH PRESSURE WILL BUILD IN FORM
THE NORTH ON WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1030 AM EDT UPDATE...TRYING TO PINPOINT TIMING OF DIURNAL
CONVECTION. SATELLITE IMAGERY SHOWING CU ALREADY POPPING UP ON THE
HIGHEST RIDGETOPS. NAM AND RAP PROG SOUNDINGS SUPPORT PLENTY OF CU
BUT A WARM LAYER AROUND 600MB LIMITS THE INSTABILITY THROUGH MUCH OF
THE AFTERNOON...FINALLY COOLING A BIT AFTER ABOUT 20Z WHEN CAPE
INCREASES TO VALUES MORE IN LINE WITH MEASURABLE PRECIP. WILL DELAY
ONSET OF POPS A BIT BUT OTHERWISE...TODAY/S FORECAST LOOKS GOOD.
AT 230 AM EDT SATURDAY...A FLAT UPPER RIDGE WILL REMAIN OVER THE
SOUTHEAST TODAY AND TONIGHT....WHILE AN UPPER TROUGH CROSSES THE
NORTHEAST...AND A SOUTHERN STREAM TROUGH CROSSES TX. A COLD FRONT
WILL CROSS OUR AREA TODAY...STALLING IN A WEST TO EAST ORIENTATION
TO OUR SOUTH TONIGHT. MOISTURE ASSOCIATED WITH THE FRONT IS EXPECTED
TO SUPPORT CONVECTIVE DEVELOPMENT IN THE MOUNTAINS TODAY WITH MODEST
INSTABILITY. BY TONIGHT...ISENTROPIC UPGLIDE SETS UP OVER THE
BOUNDARY...SUPPORTING A SMALL CHANCE OF MORE WIDESPREAD
PRECIPITATION ACROSS THE AREA. TEMPERATURES WILL BE NEAR NORMAL.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
AS OF 330 AM SATURDAY...AS PREVIOUSLY MENTIONED...THE HEAVY RAIN
EVENT LOOKS LIKELY THROUGH THE SHORT TERM PERIOD AS MODELS CONTINUE
TO SHOW A STRONG LOW PRESSURE SYSTEM OVER THE GULF COAST MOVING
ACROSS OUR CWA MONDAY THROUGH TUESDAY. BY SUNDAY...EXPECT INCREASING
MOIST SOUTHERLY FLOW ACROSS THE REGION AS THE HIGH PRESSURE SHIFTS
EAST AND THE LOW PRESSURE SLOWLY APPROACHES FROM THE GULF COAST. AS
A RESULT...MOISTURE WILL DEEPEN AND INSTABILITY WILL BE GOOD ENOUGH
TO TRIGGER WIDESPREAD SHOWERS AND THUNDERSTORMS ON SUNDAY. AS THE
SOUTHERN STREAM SHORT WAVE TROUGH AND ASSOCIATED LOW PRESSURE SYSTEM
MOVE ACROSS AL/GA MONDAY...STRONG 250 MB UPPER LEVEL JET DEVELOPS
JUST TO OUR NORTHEAST AND LINGERS THROUGH TUESDAY ALLOWING GOOD
UPPER DIVERGENCE ACROSS OUR CWA. WITH CONTINUED DEEPENING
MOISTURE...GOOD UPPER LEVEL FORCING AND INSTABILITY...WILL KEEP
LIKELY POPS ON MONDAY.
THE HEAVIEST RAIN WILL OCCUR MONDAY NIGHT THROUGH TUESDAY MORNING AS
THE CENTER OF LOW PRESSURE MOVES ACROSS OUR CWA. THE UPPER FORCING
WILL BE THE STRONGEST IN THIS PERIOD WITH THE AID OF WARM AIR
ADVECTION DRIVEN BY STRONG 850 MB SOUTHERLY JET...POSITIVE VORTICITY
ADVECTION AND GOOD UPPER LEVEL DIVERGENCE. THE LATEST MODEL RUNS
SHOW HIGHER TOTAL QPF VALUES WITH 2-4 INCHES OVER THE PIEDMONT AND
HIGHER AMOUNTS IN THE MOUNTAINS. SEVERE WEATHER IS NOT OUT OF THE
QUESTION AS MODELS CONTINUE TO SHOW 0-3 KM BULK SHEAR MAGNITUDE OF
25-30KTS OVERLAPPING DECENT CAPE VALUES OVER OUR AREA. PRECIP WILL
DECREASE FROM WEST TO EAST TUESDAY AS AN ASSOCIATED COLD FRONT
PUSHES SE ACROSS THE REGION AND DRIER AIRMASS MOVES IN FROM THE NW
BY LATE TUESDAY. TEMPERATURES WILL BE NEAR NORMAL ON SUNDAY BEFORE
DROPPING BY 3-5 DEGREES BELOW NORMAL MON/TUE.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 130 PM SATURDAY...THE MEDIUM RANGE LOOKS LIKE IT WILL BE
DOMINATED BY A LARGE UPPER TROF OVER THE EASTERN HALF OF NORTH
AMERICA. IN THE WAKE OF A DEPARTING SHORT WAVE TROF...A SHORT WAVE
RIDGE IMPOSED ON THE OVERALL LONG WAVE TROF WILL MOVE OVERHEAD
WEDNESDAY AND WEDNESDAY NIGHT. THIS WILL SUPPORT DRY HIGH PRESSURE
FOR THE END OF THE WORK WEEK. BY FRIDAY...ANOTHER STRONG SHORT WAVE
DIVING DOWN INTO THE TROF WILL CARVE OUT A NEW CLOSED LOW OVER THE
UPPER MIDWEST THAT IS FCST TO DEEPEN OVER THE WRN GREAT LAKES FRIDAY
NIGHT AND SATURDAY IN THE ECMWF. MEANWHILE...THE OPERATIONAL GFS
KEEPS THE UPPER TROF OPEN AND THUS MORE PROGRESSIVE. THE OLD GFS
ENSEMBLE MEAN GIVES MORE CONFIDENCE TO SOMETHING MORE LIKE THE ECMWF
AS IT KEEPS THE UPPER TROF AXIS TO OUR WEST ON SATURDAY...SO I AM
INCLINED TO FOLLOW THE ECMWF WITH THE TIMING OF THE NEXT FRONT. HPC
HAS THE POSITION W OF THE MTNS AT 12Z SATURDAY. THE UPPER PATTERN
SUGGESTS A SLOWER MOVEMENT OF THE FRONT AS THE TROF AXIS WILL STILL
BE OUT OVER THE OH/MID MS VALLEY BY THE END OF THE DAY. SO...THE
FCST RAMPS UP TO A CHANCE POP FROM W TO E LATE FRIDAY NIGHT AND INTO
SATURDAY AND KEEPS THAT CHANCE THROUGH THE DAY. MOISTURE FROM THE
GULF REMAINS CUT OFF FROM THIS SYSTEM SO IT SHOULD NOT BE THE RAIN
MAKER EXPECTED OF THE SYSTEM EARLY IN THE WEEK. WITH THE UPPER
PATTERN RESEMBLING SOMETHING MORE WINTER-LIKE...TEMPS WILL CONTINUE
TO RUN A CATEGORY OR TWO BELOW NORMAL THROUGH THE PERIOD.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AT KCLT...BIGGEST CONCERN THIS AFTERNOON WILL BE DIURNAL CUMULUS.
TOO DRY IN THE LOWER LEVELS TO EXPECT MUCH MORE THAN SCATTERED CU AT
VFR LEVEL TO DEVELOP UNTIL EARLY EVENING WHEN MOISTURE WILL INCREASE
AND A CEILING IS EXPECTED TO FORM BUT STILL AT VFR LEVEL. WINDS WILL
REMAIN LIGHT AND NORTHEASTERLY THEN BECOME MORE EASTERLY TONIGHT.
NOT ANTICIPATING ANY FLIGHT RESTRICTIONS OVERNIGHT DUE TO CIG OR
FOG...THOUGH PRECIPITATION CHANCES INCREASE OVERNIGHT AND SCATTERED
SHOWERS MAY PRODUCE BRIEF DROPS TO MVFR EARLY TOMORROW MORNING.
SHOWERS AND THUNDERSTORMS SHOULD INCREASE IN COVERAGE AFTER DAYBREAK
AND CEILINGS WILL MOST LIKELY LOWER WITH THE INCREASING DEEP LAYER
MOISTURE. KEPT CIG VFR TOMORROW MORNING WITH A MENTION OF VCSH UNTIL
CONFIDENCE INCREASES WITH THE PRECIP...AND OF COURSE WE MAY NEED TO
UPGRADE TO VCTS IF CONFIDENCE GETS SUFFICIENTLY HIGH THAT PRECIP
WILL OCCUR AT THE AIRFIELD.
ELSEWHERE...BKN CEILINGS ARE LIKELY TO DEVELOP OVER MUCH OF THE MTNS
THIS AFTN WITH SCATTERED SHOWERS STILL EXPECTED TO DEVELOP AS WELL.
COOLING IN THE MID TO UPPER ATMOSPHERE AFTER PEAK HEATING MAY
ACTUALLY CAUSE THE PEAK OF ACTIVITY TO BE A LITTLE LATER THAN
USUAL...BUT CONVECTION SHOULD DIMINISH AFTER SUNSET THOUGH CLOUD
COVER WILL GRADUALLY INCREASE INTO TOMORROW. MENTIONED VCSH FOR A
TIME AT KAVL THIS AFTN. CONVECTION A CONCERN ONCE AGAIN TOMORROW
WITH GREATER INSTABILITY WARRANTING A THUNDER MENTION. INCREASING
DEEP LAYER MOISTURE SHOULD ENABLE CIGS TO LOWER TO AT LEAST LOW
VFR...NOT CONFIDENT ENOUGH AT THIS POINT TO GO WITH MVFR CIGS THOUGH
THEY CANNOT BE RULED OUT.
OUTLOOK...A SLOW MOVING COLD FRONT WILL BE STALLED TO OUR SOUTH
SUNDAY. LOW PRESSURE WILL SUPPLY DEEP MOISTURE ACROSS THE REGION
SUNDAY NIGHT THROUGH MONDAY...AND RESTRICTIONS ARE LIKELY AT THAT
TIME. A STRONG COLD FRONT IS EXPECTED TO REACH THE REGION BY MID
WEEK...BRINGING IN DRIER AIR.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...JAT/WIMBERLEY
SHORT TERM...JOH
LONG TERM...PM
AVIATION...WIMBERLEY