Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/21/15
AREA FORECAST DISCUSSION
NWS TUCSON AZ
930 PM MST MON MAY 18 2015
.SYNOPSIS...A WEATHER SYSTEM PASSING NORTH OF THE AREA WILL DROP
DAYTIME TEMPERATURES A FEW DEGREES FOR TUESDAY. TEMPERATURES WILL
REBOUND WEDNESDAY AND THURSDAY BEFORE DROPPING BACK DOWN TO BELOW
NORMAL READINGS BY SATURDAY. OTHERWISE...PERIODS OF GUSTY WINDS CAN
BE ANTICIPATED THIS WEEK AS WEATHER SYSTEMS PASS THROUGH THE REGION.
&&
.DISCUSSION...ISOLATED VERY LIGHT SHOWERS OR VIRGA WERE STILL
OCCURRING ACROSS ERN PIMA ...GRAHAM AND GREENLEE COUNTIES THIS
EVENING. EVENING RUNS OF THE HRRR INDICATE THAT THESE LIGHT
SHOWERS/VIRGA WILL CONTINUE TO MOVE NNE AND MOSTLY OUT OF THE AREAS
NE OF TUCSON BY MIDNIGHT. SHORT WAVE ROTATING THRU BROAD UPPER LEVEL
TROFINESS OVER THE WRN CONUS WILL LIFT NE AWAY FROM THE AREA
TONIGHT. DRY...COOLER AND NOT AS WINDY ON TUESDAY. WARMER WEDNESDAY
WITH HIGHS SIMILAR TO TODAY THEN ANOTHER STORM SYSTEM WILL IMPACT
THE AREA THURSDAY AND FRIDAY WITH STRONG GUSTY WINDS BOTH DAYS AND
COOLER TEMPERATURES. ALL OF THIS WILL KEEP BELOW NORMAL TEMPERATURES
ACROSS MOST OF THE AREA FOR THE REMAINDER OF THE WEEK.
&&
.AVIATION...VALID THRU 20/06Z. SCT-BKN CLOUDS 12-15K FT DISSIPATING
AFTER 19/08Z BECOMING CLEAR BY 19/10Z. A FEW CUMULUS CLOUDS OVER THE
MOUNTAINS AGAIN AFTER 19/20Z. SW SFC WINDS GENERALLY LESS THAN 10
KTS OR LESS OVERNIGHT. SW WINDS REDEVELOPING TUESDAY AFTERNOON 10-15
KTS WITH GUSTS TO 25 KT. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
&&
.FIRE WEATHER...ACTIVE WEATHER PATTERN WILL CONTINUE THROUGH THE
COMING WEEKEND WITH SEVERAL WINDY PERIODS. LIGHTER WINDS AND COOLER
TEMPERATURES EXPECTED TUESDAY AND WEDNESDAY HOWEVER DEWPOINTS WILL
BE LOWER WITH SINGLE DIGIT MIN RHS BECOMING FAIRLY WIDESPREAD ACROSS
LOWER ELEVATIONS OF ZONES 151 AND 152 BY WEDNESDAY AFTERNOON.
YET ANOTHER UPPER LOW WILL APPROACH CALIFORNIA LATER WEDNESDAY WITH
AN ASSOCIATED UPPER LEVEL DISTURBANCE PASSING ACROSS THE AREA LATE
THURSDAY RESULTING IN WINDS SIMILAR TO OR SLIGHTLY STRONGER THAN
TODAY WITH LOWER HUMIDITY LEVELS FOR SPOTTY RED FLAG CONDITIONS
SOUTHERN PORTIONS OF ZONES 151-152. THEN MODELS CURRENTLY INDICATE
THE UPPER LOW WILL MOVE OVER NORTHERN ARIZONA FRIDAY FOR EVEN
STRONGER WINDS. IF THIS COMES TO PASS WINDS WILL BE EVEN STRONGER
FOR MORE WIDESPREAD CRITICAL CONDITIONS ESPECIALLY ZONE 152. BY THE
END OF A WEEK OF LOW RH LEVELS AND BREEZINESS...FUELS WILL BE MORE
RECEPTIVE AS 10 AND 100 HOUR FUELS SHOULD BECOME QUITE DRY WITH THE
CURED GRASS READY TO GO ANY AFTERNOON.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
328 PM PDT Tue May 19 2015
.Synopsis...
Variable clouds and mainly mountain showers and afternoon
thunderstorms through the week as a series of weak low pressure
systems move across California. Daytime highs forecast to remain
below normal.
&&
.Discussion...
Broad upper low is over California and will only gradually shift
east into the weekend. Not as much activity as shown by short
range models thus far this afternoon over the mountains. The best
coverage is over the coastal range...not much at all over the
Sierra. HRRR model shows best activity over the coastal range and
the Sierra south of Kirkwood through the evening. WRF core model
indicates more mountain shower and thunderstorm activity Wednesday
and Thursday with possibly an isolated cell or two in valley.
Weak/moderate onshore flow will keep temperatures slightly below
normal srn sac/nrn sj valleys into the weekend.
&&
.Extended Discussion (Saturday through Tuesday)
Area will be sandwiched between ridging building over eastern
Pacific and trough departing to the east for the start of the weekend.
Models continue to differ on the track and speed of the trough as
it departs. GFS moves the trough off faster to the east with
riding across the area for the weekend into Tuesday, which would
lead to a dry forecast. ECMWF/GEM are slower with the departure
and continue the chance for mountain showers and thunderstorms
through at least Sunday. Given uncertainty, have not made major
changes to going forecast. Feel that there may be enough
instability present to continue the chance for daily showers and
thunderstorms across higher terrain through Sunday for now. May
then see a break in convection for Monday and Tuesday. Regardless,
valley should remain dry in either scenario. Temperatures will
hover within a few degrees of normal with valley highs generally
in the 80s and foothills/mountains in the 50s to 60s. CEO
&&
.Aviation...
Mainly VFR conditions for interior NorCal except during showers
and afternoon/evening thunderstorms that bring periods of MVFR.
Best chance for showers/thunderstorms is across higher terrain and far
northern portions of Sacramento valley. The onshore flow will
bring light winds to TAF sites around 5-12 kts. Delta breeze will
be 10-20 kts with gusts up to 25 kts.
&&
.STO Watches/Warnings/Advisories...
None.
&&
$$
AREA FORECAST DISCUSSION
NWS RENO NV
1032 PM PDT MON MAY 18 2015
.UPDATE...
SHOWERS HAVE INCREASED THIS EVENING ALONG A SUSANVILLE TO PYRAMID
LAKE TO LOVELOCK LINE AND ARE MOVING SOUTH. THESE SHOWERS HAVE
ACTUALLY INCREASED IN INTENSITY THE LAST HOUR, AND EXPECT THESE TO
CONTINUE THROUGH AT LEAST MIDNIGHT BEFORE GRADUALLY WANING AS THEY
MOVE SOUTH. AS A RESULT, HAVE INCREASED POPS FOR THE SIERRA FRONT
AND TAHOE REGION AS WELL AS HIGHWAY 50 EAST THROUGH FALLON. HRRR
SHOWS THE SHOWERS DIMINISHING ABOUT THIS TIME WHICH SEEMS
REASONABLE, BUT CONFIDENCE IN THE MODEL IS LOW. IT HAS PERFORMED
RATHER POORLY THE LAST COUPLE NIGHTS AFTER CONVECTIVE INITIATION
AND BEYOND 3 HOURS. AT THIS POINT THOUGH, IT SEEMS REASONABLE AND
IS SIMILAR TO MY BEST GUESS SO WILL RUN WITH IT.
RAINFALL AMOUNTS WITH THE SHOWERS SHOULD AVERAGE AROUND A TENTH OF
AN INCH, BUT LOCALLY HIGHER AMOUNTS TO 1/3 INCH ARE POSSIBLE. AS
OF THIS WRITING THE HEAVIEST RAINS LOOK MOST LIKELY TO OCCUR IN
SPANISH SPRINGS, HIDDEN VALLEY AND AROUND LOCKWOOD. WALLMANN
&&
.AVIATION...
SCATTERED SHOWERS CONTINUE THIS EVENING NEAR AND SOUTH OF I-80.
CIGS 3-4000 FEET WILL OCCUR IN THE SHOWERS THRU 10Z FOR
KTVL/KTRK/KRNO/KCXP. LOW CLOUD DECKS AND RAIN SHOWERS WILL CREATE
SOME MOUNTAIN OBSCURATION IN THE SIERRA. GENERALLY LIGHT WEST
WINDS WITH THE CHANCE OF GUSTS TO AROUND 30 KTS NEAR
THUNDERSTORMS. A FEW MORE SHOWERS ARE EXPECTED TUESDAY, BUT
COVERAGE IS EXPECTED TO BE LESS THAN THE LAST TWO DAYS.
TOLBY/WALLMANN
&&
.PREVIOUS DISCUSSION... /ISSUED 300 PM PDT MON MAY 18 2015/
SYNOPSIS...
LOW PRESSURE ALOFT WILL REMAIN OVER CALIFORNIA AND NEVADA THROUGH
THE END OF THE WORK WEEK, BRINGING BELOW AVERAGE TEMPERATURES
AND ROUNDS OF SHOWERS AND THUNDERSTORMS, MAINLY IN THE AFTERNOONS
AND EVENINGS. PRECIPITATION CHANCES DECREASE OVER THE MEMORIAL
DAY WEEKEND ALTHOUGH A FEW SHOWERS AND THUNDERSTORMS WILL STILL
BE POSSIBLE.
SHORT TERM...
A TROUGH OF LOW PRESSURE REMAINS OVER THE WEST. AN UPPER
DISTURBANCE OVER SOUTHEAST CALIFORNIA AND SOUTHERN NEVADA IS
ROTATING AROUND THE TROUGH, BRINGING INCREASED DIVERGENCE ALOFT
AND HELPING TO INITIATE SHOWERS AND THUNDERSTORMS OVER SOUTHERN
AND EASTERN NEVADA.
FOR NORTHEAST CALIFORNIA AND WESTERN NEVADA, ACTIVITY IS RESTRICTED
EARLY THIS AFTERNOON WITH THE BEST FORCING SOUTH AND EAST OF THE
AREA. HOWEVER, SCATTERED SHOWERS SHOULD STILL DEVELOP GIVEN THE
MOIST AND WEAKLY UNSTABLE ATMOSPHERE, ESPECIALLY FOR EASTERN
CALIFORNIA AND FAR WESTERN NEVADA WHERE THE HRRR AND NAM SHOW A
LIGHT WESTERLY FLOW OFF THE SIERRA (TO AID LOW LEVEL CONVERGENCE
AND UPWARD MOTION) INTO THE EVENING. AS FAR AS THUNDERSTORMS, LOW
FREEZING LEVELS AND WEAK INSTABILITY MAKE IT HARD TO RULE OUT
BRIEF, ISOLATED CELLS. ANY STORMS THIS EVENING WILL BE WEAK WITH
THE MAIN THREAT BEING LIGHTNING AND LARGE QUANTITIES OF SMALL,
SOFT HAIL (GRAUPEL TECHNICALLY).
LATE TONIGHT, THE HRRR AND LESS-SO THE GFS AND NAM ARE INDICATING
WRAP-AROUND PRECIPITATION OVER NORTHEAST CALIFORNIA AND NORTHWEST
NEVADA AS THE UPPER LOW ADVANCES INTO EASTERN NEVADA. WITH THIS IN
MIND, I HAVE LEFT IN SCATTERED SHOWERS NORTH OF RENO AND FALLON
WITH ISOLATED COVERAGE ELSEWHERE.
TUESDAY, THE REGION IS BETWEEN UPPER WAVES. HOWEVER, MOISTURE
REMAINS IN PLACE AND BETTER HEATING IS POSSIBLE WITH LITTLE UPPER
FORCING ALLOWING FOR LESS/THINNER CLOUD COVER IN THE MORNING. THIS
SHOULD FACILITATE SCATTERED SHOWERS IN THE AFTERNOON AND EVENING,
WITH A LOW CHANCE FOR THUNDERSTORMS.
WEDNESDAY, THE BEST UPPER FORCING OF THE SHORT TERM IS EXPECTED AS
ANOTHER DISTURBANCE RELOADS THE SOUTHWEST CONUS TROUGH. THE
DISTURBANCE IS EXPECTED TO MOVE FROM SOUTH TO NORTH THROUGH
CALIFORNIA WITH THE BEST FORCING IN THE AFTERNOON AND EVENING.
WITH THIS IN MIND, I HAVE BUMPED POP A BIT MORE OVER MUCH OF FAR
WESTERN NEVADA AND EASTERN CALIFORNIA WITH NUMEROUS SHOWERS EXPECTED
BY AFTERNOON. WITH THE FORCING, I WOULD EXPECTED AT LEAST ISOLATED
THUNDERSTORMS WITH HIGHER COVERAGE POSSIBLE IF WE CAN GET DECENT
MORNING HEATING (CLEARER SKIES). SNYDER
LONG TERM...THURSDAY THROUGH MONDAY...
BY THURSDAY AN AREA OF LOW PRESSURE WILL AGAIN BE ALONG THE
CENTRAL CALIFORNIA COAST. THIS WILL CONTINUE TO BRING WIDESPREAD
CHANCES OF PRECIPITATION, ISOLATED THUNDERSTORMS, AND BELOW
AVERAGE DAYTIME TEMPERATURES. THURSDAY CURRENTLY LOOKS TO BE THE
WETTEST DAY WITH MOISTURE WRAPPING AROUND THE LOW PRESSURE AND
BANKING AGAINST THE SIERRA FROM THE EAST. RELATIVELY DEEP MOISTURE
AND UPSLOPE FLOW COULD ALLOW SOME AREAS TO PICK UP ANOTHER ROUND
OF SIGNIFICANT PRECIPITATION, ESPECIALLY IN THE CENTRAL SIERRA.
BY FRIDAY THE LOW PRESSURE WILL MOVE INTO SOUTHERN NEVADA
BRINGING NORTHERLY FLOW TO THE AREA. THIS WILL DECREASE THE CHANCE
OF SIGNIFICANT QPF IN THE SIERRA, BUT WILL STILL ALLOW WIDESPREAD
PRECIPITATION TO WESTERN NEVADA AND THE SIERRA.
FOR THE HOLIDAY WEEKEND...
CHANCES FOR THUNDERSTORMS WILL BE ON THE DECREASE BY THE HOLIDAY
WEEKEND AS THE LOW PRESSURE MOVES INTO THE ROCKIES, BUT WITH SOME
RESIDUAL MOISTURE AND INCREASING TEMPERATURES THERE IS STILL A
SLIGHT CHANCE OF THUNDERSTORM ACTIVITY IN SIERRA AND WESTERN
NEVADA THROUGH THE WEEKEND. SIGNIFICANT MODEL DISCREPANCIES EXIST
BY THE WEEKEND SO FORECAST CONFIDENCE IS CURRENTLY LOW ON THE
BEST AREA FOR THUNDERSTORM CHANCES.
EXPECT A WARMING TREND THROUGH THE WEEKEND WITH DAYTIME
TEMPERATURES RIGHT AROUND SEASONAL AVERAGES WITH MID 70`S IN
WESTERN NEVADA AND MID 60`S IN THE SIERRA. BY MONDAY WESTERN
NEVADA VALLEYS COULD HIT 80 WITH SIERRA VALLEYS REACHING 70.
TOLBY
AVIATION...
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED
THROUGHOUT THE SIERRA AND WESTERN NEVADA THROUGH THIS EVENING.
LOW CLOUD DECKS AND RAIN SHOWERS WILL CREATE SOME MOUNTAIN
OBSCURATION IN THE SIERRA. GENERALLY LIGHT WEST WINDS WITH THE
CHANCE OF GUSTS TO AROUND 30 KTS NEAR THUNDERSTORMS. TOLBY
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS NEW YORK NY
431 PM EDT TUE MAY 19 2015
.SYNOPSIS...
A COLD FRONT CROSSES THE REGION TONIGHT. THE FRONT STALLS TO THE
SOUTH INTO THURSDAY AS HIGH PRESSURE BUILDS IN FROM THE WEST
THROUGH THURSDAY. LOW PRESSURE PASSES TO THE SOUTHEAST THURSDAY
NIGHT INTO FRIDAY MORNING...THEN A WEAK COLD FRONT MOVES THROUGH
FRIDAY AFTERNOON INTO EVENING. HIGH PRESSURE THEN CONTROLS THE
WEATHER THROUGH SUNDAY...FOLLOWED BY AN APPROACHING WARM FRONT ON
MONDAY. THIS BOUNDARY THEN STALLS NEAR THE AREA INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
SURFACE WARM FRONT STILL EDGING EASTWARD...BASICALLY TO NEAR THE
HUDSON RIVER AT 19Z...AND INCHING EAST. COLD FRONT IS FAST ON ITS
HEELS FROM EASTERN UPSTATE NEW YORK BACK INTO NE PA. MAIN QUESTION
IS HOW MUCH CONVECTION THAT FIRES ALONG THE FRONT OVER THE
CATSKILLS/POCONOS HOLDS TOGETHER IS IT TRACKS SE INTO THE CWA. NAM
IS MOST AGGRESSIVE...AND APPEARS ON OUTLIER. OTHER HI-RES MODELS
INCLUDING RAP AND HRRR AS WELL AS SREF SUGGESTS LITTLE IF
ANYTHING HOLD TOGETHER EAST OF THE HUDSON. POPS ARE WEIGHED
TOWARDS THIS CONSENSUS.
RAP SHOWING POTENTIAL FOR AROUND 1000 J/KG CAPE OVER THE LOWER
HUDSON VALLEY/NE NJ SO POTENTIAL FOR SOME LOCALLY STRONG STORMS
THERE...WITH LOCALLY HEAVY RAINFALL AS WELL NOTING PRECIPITABLE
WATERS TO AROUND 1.5 INCHES JUST AHEAD OF THE FRONT. COULD ALSO
SEE A FEW HUNDRED J/KG OF CAPE INTO INTERIOR SW CT ZONES...SO DO
HAVE CHANCE THUNDER IN FOR NE NJ/LOWER HUDSON VALLEY/SW CT AHEAD
OF THE FRONT.
SHOULD CLEAR OUT FAIRLY QUICKLY BEHIND THE FRONT...WITH 20-25KT
DOWNSLOPING BL WINDS. SO COULD SEE GUSTS TO AROUND 20 TO MAYBE
OCCASIONALLY 25 MPH BY MORNING.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
MAINLY ZONAL FLOW ALOFT WEDNESDAY-WEDNESDAY NIGHT...AND WITH BEST
FORCING WITH A PASSING N STREAM SHORT WAVE STAYING WELL TO THE
N...WENT WITH A DRY FORECAST IN THIS TIME FRAME.
GUSTY WINDS SHOULD CONTINUE THROUGH THE MORNING...THEN DIMINISH
INTO THE AFTERNOON AS LOW LEVEL WINDS REDUCE DOWN TO 15-20KT BY
MID TO LATE AFTERNOON. WINDS CONTINUE TO DIMINISH WEDNESDAY
NIGHT...WHICH COUPLED WITH MINIMAL CLOUD COVER SHOULD PROMOTE
SOLID RADIATIONAL COOLING.
FOR HIGHS WEDNESDAY USED A BLEND OF MIXING DOWN FROM 875-850 HPA
PER BUFKIT SOUNDINGS WITH NAM 2-METER TEMPERATURES AND A BLEND OF
MAV/MET/ECS GUIDANCE. HIGHS SHOULD BE A FEW DEGREES BELOW NORMAL.
FOR LOWS WEDNESDAY NIGHT...A BLEND OF ECS/MAV/MET GUIDANCE WAS
USED...TWEAKED DOWN SLIGHTLY OVER NORMALLY COLDER LOCATIONS. LOWS
SHOULD BE AROUND 5-10 DEGREES BELOW NORMAL.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
MOST OF THE GUIDANCE KEEPS THE DAYTIME HOURS OF THURSDAY DRY WITH
HIGH PRESSURE BEING THE MAIN INFLUENCE. AT THE LEAST...BROKEN TO
OVERCAST MID TO HIGH LEVEL CLOUDS DEVELOP. SO PARTLY SUNNY TO MOSTLY
CLOUDY. A BLEND OF MAV/NAM MOS LOOKED REASONABLE FOR HIGH
TEMPERATURES.
HAVE INSERTED SLIGHT CHANCE POPS FOR THURSDAY NIGHT FOR THE
SOUTHERN ZONES AS LOW PRESSURE PASSES TO THE SOUTHEAST...BRINGING
THE NORTHERN FRINGE OF THE PRECIPITATION SHIELD TO THIS PART OF
THE CWA. A COLD FRONT THEN FOLLOWS FRIDAY AFTERNOON INTO EVENING.
MOISTURE IS LACKING...BUT AN ISOLATED SHOWER IS NOT OUT OF THE
QUESTION. WILL HOWEVER MAINTAIN A DRY FORECAST FOR NOW. HIGHS FOR
FRIDAY SLIGHTLY ABOVE NORMAL.
HIGH PRESSURE IS THEN RESTORED FOR THE WEEKEND WITH DRY WEATHER
HIGHS SATURDAY IN THE MID-UPPER 60S...THEN WARMING INTO THE LOW-MID
70S ON SUNDAY AS WINDS SHIFT SW.
A WARM FRONT APPROACHES FROM THE SW LATE SUNDAY NIGHT. MEANWHILE...A
COLD FRONT DROPS DOWN FROM THE NORTH. SOME UNCERTAINTY REGARDING HOW
FAR SOUTH IT PUSHES. GIVEN MODEL AGREEMENT OF UPPER RIDGING...WILL
FAVOR THE IDEA THAT THE COLD FRONT REMAINS TO THE NORTH...OR AT MOST
PASSES THROUGH PART OF THE CWA BEFORE RETREATING BACK NORTH. IN ANY
CASE...WILL CARRY CHANCE POPS LATE SUN NIGHT THROUGH TUESDAY WITH
BOTH FRONTS NEARBY. A RUMBLE OF THUNDER ALSO POSSIBLE WITH SOME
CAPE PRESENT AFTER SUNDAY NIGHT.
&&
.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
A COLD FRONT ACROSS UPSTATE NY WILL PASS THRU THE REGION TONIGHT.
MAINLY VFR THRU 00Z...ESPECIALLY THE METRO. TSTMS APPEAR THEY WILL
REMAIN RELEGATED TO AREAS NW OF THE CITY THIS EVE. VCTS INCLUDED FOR
KSWF...OTHERWISE NO TSTMS FORECAST ELSEWHERE. THERE IS A LOW PROB
THAT TSTMS HOLD TOGETHER TO IMPACT THE METRO. MOST LIKELY SCENARIO
IS SCT -RA. VFR BEHIND THE COLD FRONT TONIGHT.
LIGHT SW WIND THIS EVE...WITH COMPLICATED MARINE INFLUENCED FLOW
AT THE COASTAL TERMINALS. WINDS BECOME NW BEHIND THE FRONT...WITH
SPEEDS GENERALLY 15-25 KT THRU THE REMAINDER OF THE TAF PERIOD.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT:
HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: SOME VARIABILITY IN WIND DIRECTION POSSIBLE
THRU 4Z. LOW CHANCE FOR MVFR CIGS 00Z TO 04Z.
KLGA FCSTER COMMENTS: SOME VARIABILITY IN WIND DIRECTION POSSIBLE
THEREAFTER THRU 4Z. LOW CHANCE FOR MVFR CIGS 00Z TO 04Z.
KEWR FCSTER COMMENTS: SIGNIFICANT CHANGES TO WIND DIRECTION THRU
3Z MAY BE NEEDED IF SEA BREEZE FLOW DEVELOPS...BRINGING WINDS TO
AROUND 140 TRUE. LOW PROB OF RESIDUAL TSTMS REACHING THE TERMINAL
AFT 00Z.
KTEB FCSTER COMMENTS: LOW PROB OF RESIDUAL TSTMS REACHING THE
TERMINAL AFT 00Z.
KHPN FCSTER COMMENTS: LOW PROB OF RESIDUAL TSTMS REACHING THE
TERMINAL AFT 00Z.
KISP FCSTER COMMENTS: CONDITIONS MAY REMAIN VFR TIL AROUND 00Z.
.OUTLOOK FOR 18Z WEDNESDAY THROUGH SATURDAY...
.WED...VFR. NW WINDS 15-25KT.
.THU...VFR WITH SW WINDS.
.FRI...VFR WITH W FLOW BECOMING NW.
.SAT...VFR WITH VRB WINDS.
.SUN...VFR WITH SW WINDS.
&&
.MARINE...
WINDS INCREASE THIS EVENING BEHIND A COLD FRONT...AND REMAIN GUSTY
TO AROUND 20 KT...WITH OCCASIONAL GUSTS TO AROUND 25 KT NEAR
SHORE IN THE NY BIGHT REGION...INTO WEDNESDAY EVENING...BEFORE
SUBSIDING LATER WEDNESDAY NIGHT. FOR NOW EXPECT CONDITIONS TO
STAY JUST BELOW SCA LEVELS...HOWEVER CANNOT COMPLETELY RULE OUT A
FEW HOURS OF GUSTS TO AROUND 25 KT NEAR SHORE AROUND NYC/WESTERN
LONG ISLAND WEDNESDAY MORNING.
SEAS ARE EXPECTED TO REMAIN BELOW 5 FT THROUGH THE REST OF THE
FORECAST PERIOD. THERE COULD BE HOWEVER BE FREQUENT GUSTS TO SCA
CRITERIA FRIDAY AFTERNOON AND EVENING BEHIND A COLD FRONT.
&&
.FIRE WEATHER...
WINDS WILL GUSTS TO AROUND 20 TO OCCASIONALLY 25 MPH WEDNESDAY
MORNING...THEN GUSTS SHOULD SLACKEN IN THE AFTERNOON. MINIMUM
RELATIVE HUMIDITIES ARE GENERALLY FORECAST TO BE 30-25
PERCENT...EXCEPT 25-30 PERCENT IN THE IMMEDIATE NYC METRO. GIVEN
THE UNCERTAINTY...PLUS UNCERTAINTY ON HOW MUCH RAINFALL WILL BE
RECEIVED THIS EVENING. WILL HOLD OFF ON ISSUING ANY FIRE WEATHER
RELATED PRODUCTS FOR WEDNESDAY AT THIS TIME.
&&
.HYDROLOGY...
GENERALLY LESS THAN .2 INCHES OF RAIN IS EXPECTED THROUGH THIS
EVENING. HOWEVER...ANY STRONGER CONVECTION WHICH DOES OCCUR OVER
MAINLY NE NJ/LOWER HUDSON VALLEY/SW CT COULD PRODUCE LOCALLY HEAVY
RAINFALL. IF THIS WERE TO OCCUR...THEN THE PONDING OF WATER ON
ROADWAYS WOULD BE POSSIBLE.
NO SIGNIFICANT PRECIPITATION AMOUNTS ARE EXPECTED FROM LATE
TONIGHT THROUGH SUNDAY.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JC/MALOIT
NEAR TERM...MALOIT
SHORT TERM...MALOIT
LONG TERM...JC
AVIATION...JMC/DS
MARINE...JC/MALOIT
FIRE WEATHER...
HYDROLOGY...JC/MALOIT
AREA FORECAST DISCUSSION
NWS NEW YORK NY
343 PM EDT TUE MAY 19 2015
.SYNOPSIS...
A COLD FRONT CROSSING THE REGION TONIGHT. THE FRONT STALLS TO THE
SOUTH INTO THURSDAY AS HIGH PRESSURE BUILDS IN FROM THE WEST
THROUGH THURSDAY. LOW PRESSURE PASSES TO THE SOUTHEAST THURSDAY
NIGHT INTO FRIDAY MORNING...THEN A WEAK COLD FRONT MOVES THROUGH
FRIDAY AFTERNOON INTO EVENING. HIGH PRESSURE THEN CONTROLS THE
WEATHER THROUGH SUNDAY...FOLLOWED BY AN APPROACHING WARM FRONT ON
MONDAY. THIS BOUNDARY THEN STALLS NEAR THE AREA INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
SURFACE WARM FRONT STILL EDGING EASTWARD...BASICALLY TO NEAR THE
HUDSON RIVER AT 19Z...AND INCHING EAST. COLD FRONT IS FAST ON ITS
HEELS FROM EASTERN UPSTATE NEW YORK BACK INTO NE PA. MAIN QUESTION
IS HOW MUCH CONVECTION THAT FIRES ALONG THE FRONT OVER THE
CATSKILLS/POCONOS HOLDS TOGETHER IS IT TRACKS SE INTO THE CWA. NAM
IS MOST AGGRESSIVE...AND APPEARS ON OUTLIER. OTHER HI-RES MODELS
INCLUDING RAP AND HRRR AS WELL AS SREF SUGGESTS LITTLE IF
ANYTHING HOLD TOGETHER EAST OF THE HUDSON. POPS ARE WEIGHED
TOWARDS THIS CONSENSUS.
RAP SHOWING POTENTIAL FOR AROUND 1000 J/KG CAPE OVER THE LOWER
HUDSON VALLEY/NE NJ SO POTENTIAL FOR SOME LOCALLY STRONG STORMS
THERE...WITH LOCALLY HEAVY RAINFALL AS WELL NOTING PRECIPITABLE
WATERS TO AROUND 1.5 INCHES JUST AHEAD OF THE FRONT. COULD ALSO
SEE A FEW HUNDRED J/KG OF CAPE INTO INTERIOR SW CT ZONES...SO DO
HAVE CHANCE THUNDER IN FOR NE NJ/LOWER HUDSON VALLEY/SW CT AHEAD
OF THE FRONT.
SHOULD CLEAR OUT FAIRLY QUICKLY BEHIND THE FRONT...WITH 20-25KT
DOWNSLOPING BL WINDS. SO COULD SEE GUSTS TO AROUND 20 TO MAYBE
OCCASIONALLY 25 MPH BY MORNING.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
MAINLY ZONAL FLOW ALOFT WEDNESDAY-WEDNESDAY NIGHT...AND WITH BEST
FORCING WITH A PASSING N STREAM SHORT WAVE STAYING WELL TO THE
N...WENT WITH A DRY FORECAST IN THIS TIME FRAME.
GUSTY WINDS SHOULD CONTINUE THROUGH THE MORNING...THEN DIMINISH
INTO THE AFTERNOON AS LOW LEVEL WINDS REDUCE DOWN TO 15-20KT BY
MID TO LATE AFTERNOON. WINDS CONTINUE TO DIMINISH WEDNESDAY
NIGHT...WHICH COUPLED WITH MINIMAL CLOUD COVER SHOULD PROMOTE
SOLID RADIATIONAL COOLING.
FOR HIGHS WEDNESDAY USED A BLEND OF MIXING DOWN FROM 875-850 HPA
PER BUFKIT SOUNDINGS WITH NAM 2-METER TEMPERATURES AND A BLEND OF
MAV/MET/ECS GUIDANCE. HIGHS SHOULD BE A FEW DEGREES BELOW NORMAL.
FOR LOWS WEDNESDAY NIGHT...A BLEND OF ECS/MAV/MET GUIDANCE WAS
USED...TWEAKED DOWN SLIGHTLY OVER NORMALLY COLDER LOCATIONS. LOWS
SHOULD BE AROUND 5-10 DEGREES BELOW NORMAL.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
MOST OF THE GUIDANCE KEEPS THE DAYTIME HOURS OF THURSDAY DRY WITH
HIGH PRESSURE BEING THE MAIN INFLUENCE. AT THE LEAST...BROKEN TO
OVERCAST MID TO HIGH LEVEL CLOUDS DEVELOP. SO PARTLY SUNNY TO MOSTLY
CLOUDY. A BLEND OF MAV/NAM MOS LOOKED REASONABLE FOR HIGH
TEMPERATURES.
HAVE INSERTED SLIGHT CHANCE POPS FOR THURSDAY NIGHT FOR THE
SOUTHERN ZONES AS LOW PRESSURE PASSES TO THE SOUTHEAST...BRINGING
THE NORTHERN FRINGE OF THE PRECIPITATION SHIELD TO THIS PART OF
THE CWA. A COLD FRONT THEN FOLLOWS FRIDAY AFTERNOON INTO EVENING.
MOISTURE IS LACKING...BUT AN ISOLATED SHOWER IS NOT OUT OF THE
QUESTION. WILL HOWEVER MAINTAIN A DRY FORECAST FOR NOW. HIGHS FOR
FRIDAY SLIGHTLY ABOVE NORMAL.
HIGH PRESSURE IS THEN RESTORED FOR THE WEEKEND WITH DRY WEATHER
HIGHS SATURDAY IN THE MID-UPPER 60S...THEN WARMING INTO THE LOW-MID
70S ON SUNDAY AS WINDS SHIFT SW.
A WARM FRONT APPROACHES FROM THE SW LATE SUNDAY NIGHT. MEANWHILE...A
COLD FRONT DROPS DOWN FROM THE NORTH. SOME UNCERTAINTY REGARDING HOW
FAR SOUTH IT PUSHES. GIVEN MODEL AGREEMENT OF UPPER RIDGING...WILL
FAVOR THE IDEA THAT THE COLD FRONT REMAINS TO THE NORTH...OR AT MOST
PASSES THROUGH PART OF THE CWA BEFORE RETREATING BACK NORTH. IN ANY
CASE...WILL CARRY CHANCE POPS LATE SUN NIGHT THROUGH TUESDAY WITH
BOTH FRONTS NEARBY. A RUMBLE OF THUNDER ALSO POSSIBLE WITH SOME
CAPE PRESENT AFTER SUNDAY NIGHT.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
A COLD FRONT ACROSS UPSTATE NY WILL PASS THRU THE REGION TONIGHT.
MAINLY VFR THRU 00Z...ESPECIALLY THE METRO. TSTMS APPEAR THEY WILL
REMAIN RELEGATED TO AREAS NW OF THE CITY THIS EVE. VCTS INCLUDED FOR
KSWF...OTHERWISE NO TSTMS FORECAST ELSEWHERE. THERE IS A LOW PROB
THAT TSTMS HOLD TOGETHER TO IMPACT THE METRO. MOST LIKELY SCENARIO
IS REMNANT MVFR CIGS AND PERHAPS SOME -RA. VFR BEHIND THE COLD
FRONT TONIGHT.
LIGHT SW WIND THIS EVE...WITH COMPLICATED MARINE INFLUENCED FLOW
AT THE COASTAL TERMINALS. WINDS BECOME NW BEHIND THE FRONT...WITH
SPEEDS GENERALLY 15-25 KT THRU THE REMAINDER OF THE TAF PERIOD.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT:
HTTP://WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: SOME VARIABILITY IN WIND DIRECTION POSSIBLE
THRU 4Z.
KLGA FCSTER COMMENTS: WINDS MAY REMAIN FROM THE NE BEYOND 20Z. SOME
VARIABILITY IN WIND DIRECTION POSSIBLE THEREAFTER THRU 4Z.
KEWR FCSTER COMMENTS: SIGNIFICANT CHANGES TO WIND DIRECTION THRU
3Z MAY BE NEEDED IF SEA BREEZE FLOW DEVELOPS...BRINGING WINDS TO
AROUND 140 TRUE. LOW PROB OF RESIDUAL TSTMS REACHING THE TERMINAL
AFT 00Z.
KTEB FCSTER COMMENTS: LOW PROB OF RESIDUAL TSTMS REACHING THE
TERMINAL AFT 00Z.
KHPN FCSTER COMMENTS: LOW PROB OF RESIDUAL TSTMS REACHING THE
TERMINAL AFT 00Z.
KISP FCSTER COMMENTS: CONDITIONS MAY REMAIN VFR TIL AROUND 00Z.
.OUTLOOK FOR 18Z WEDNESDAY THROUGH SATURDAY...
.WED...VFR. NW WINDS 15-25KT.
.THU...VFR WITH SW WINDS.
.FRI...VFR WITH W FLOW BECOMING NW.
.SAT...VFR WITH VRB WINDS.
.SUN...VFR WITH SW WINDS.
&&
.MARINE...
WINDS INCREASE THIS EVENING BEHIND A COLD FRONT...AND REMAIN GUSTY
TO AROUND 20 KT...WITH OCCASIONAL GUSTS TO AROUND 25 KT NEAR
SHORE IN THE NY BIGHT REGION...INTO WEDNESDAY EVENING...BEFORE
SUBSIDING LATER WEDNESDAY NIGHT. FOR NOW EXPECT CONDITIONS TO
STAY JUST BELOW SCA LEVELS...HOWEVER CANNOT COMPLETELY RULE OUT A
FEW HOURS OF GUSTS TO AROUND 25 KT NEAR SHORE AROUND NYC/WESTERN
LONG ISLAND WEDNESDAY MORNING.
&&
.FIRE WEATHER...
WINDS WILL GUSTS TO AROUND 20 TO OCCASIONALLY 25 MPH WEDNESDAY
MORNING...THEN GUSTS SHOULD SLACKEN IN THE AFTERNOON. MINIMUM
RELATIVE HUMIDITIES ARE GENERALLY FORECAST TO BE 30-25
PERCENT...EXCEPT 25-30 PERCENT IN THE IMMEDIATE NYC METRO. GIVEN
THE UNCERTAINTY...PLUS UNCERTAINTY ON HOW MUCH RAINFALL WILL BE
RECEIVED THIS EVENING. WILL HOLD OFF ON ISSUING ANY FIRE WEATHER
RELATED PRODUCTS FOR WEDNESDAY AT THIS TIME.
&&
.HYDROLOGY...
GENERALLY LESS THAN .2 INCHES OF RAIN IS EXPECTED THROUGH THIS
EVENING. HOWEVER...ANY STRONGER CONVECTION WHICH DOES OCCUR OVER
MAINLY NE NJ/LOWER HUDSON VALLEY/SW CT COULD PRODUCE LOCALLY HEAVY
RAINFALL. IF THIS WERE TO OCCUR...THEN THE PONDING OF WATER ON
ROADWAYS WOULD BE POSSIBLE.
NO SIGNIFICANT PRECIPITATION AMOUNTS ARE EXPECTED FROM LATE
TONIGHT THROUGH SUNDAY.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JC/MALOIT
NEAR TERM...MALOIT
SHORT TERM...MALOIT
LONG TERM...JC
AVIATION...JMC
MARINE...JC/MALOIT
FIRE WEATHER...
HYDROLOGY...JC/MALOIT
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
352 PM EDT TUE MAY 19 2015
.SYNOPSIS...
A COLD FRONT APPROACHING FROM THE WEST WILL PASS THROUGH OUR
REGION EARLY TONIGHT. HIGH PRESSURE IS FORECAST TO FOLLOW FOR
WEDNESDAY INTO WEDNESDAY NIGHT. WEAK LOW PRESSURE IS EXPECTED TO
BE LOCATED OVER NORTH CAROLINA ON THURSDAY BEFORE IT MOVES OUT TO
SEA ON THURSDAY NIGHT. A COLD FRONT FROM THE NORTHWEST IS
ANTICIPATED TO ARRIVE ON FRIDAY EVENING WITH HIGH PRESSURE
FORECAST TO BUILD ACROSS OUR REGION IN ITS WAKE FOR SATURDAY. A
WARM FRONT IS EXPECTED TO APPROACH FROM THE SOUTHWEST ON SUNDAY
AND MONDAY, AS A COLD FRONT PUSHES DOWN FROM THE NORTH AND
NORTHEAST. ANOTHER FRONTAL BOUNDARY MAY MOVE TOWARD OUR REGION
FROM THE NORTHWEST ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THE COLD FRONT WILL MOVE THROUGH THE CWA THIS EVENING AND BRING A
SMALL CHANCE OF SHOWERS AND THUNDERSTORMS. THE HRRR CONTINUES TO
HIT THINGS TOO HARD. WE HAVE NOTHING HIGHER THAN CHANCE.
NORTHWEST WINDS WILL WORK INTO THE REGION BEHIND THE COLD FRONT.
WHILE WE COULD SEE SOME GUSTS OVERNIGHT, IN GENERAL, SPEEDS SHOULD
REMAIN RIGHT AROUND 10 MPH.
OVERNIGHT LOWS WILL DROP INTO THE MID TO UPPER 40S ACROSS THE FAR
NORTHWEST AND INTO THE 50S ELSEWHERE. THE EXCEPTION MIGHT BE
SOUTHERN DELAWARE WHERE A LOW OF 60 IS POSSIBLE. THESE TEMPS
AREN`T TOO FAR FROM NORMAL.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
FOR TOMORROW, LOOKS LIKE LOTS OF SUNSHINE WITH BROAD SURFACE HIGH
PRESSURE NOSING IN FROM THE WEST. TEMPS WILL BE COOLER THAN WHAT
WE`RE SEEING TODAY AND SHOULD TOP OUT RIGHT AROUND 60 ACROSS THE
FAR NORTHWEST, IN THE 60S ACROSS THE LEHIGH VALLEY AND NORTHERN
COASTAL PLAIN , AND IN THE 70S ELSEWHERE. HUMIDITY LEVELS WILL BE
LOW. IT WILL BE BREEZY WITH NORTHWEST WIND GUSTS REACHING 20 TO 25
MPH.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
HIGH PRESSURE IS FORECAST TO CONTINUE INFLUENCING OUR WEATHER
INTO WEDNESDAY NIGHT. HOWEVER, HIGH AND MID LEVEL CLOUDS WILL BE
ON THE INCREASE, ESPECIALLY AFTER MIDNIGHT. LOW TEMPERATURES ARE
ANTICIPATED TO BE MAINLY IN THE 40S AND LOWER 50S IN OUR REGION
WITH A FEW READINGS IN THE UPPER 30S IN THE FAR NORTH.
THE MODEL GUIDANCE IS COMING INTO BETTER AGREEMENT REGARDING
THURSDAY`S WEAK LOW IN NORTH CAROLINA AND ITS IMPACTS ON OUR
WEATHER. IT APPEARS AS THOUGH MID LEVEL CLOUDS WILL BE OVERHEAD
FOR MUCH OF THURSDAY INTO THURSDAY EVENING. A DECK OF
STRATOCUMULUS IS ANTICIPATED TO EXPAND OVER OUR SOUTHERN COUNTIES
ON THURSDAY BEFORE CLEARING GRADUALLY FROM THE NORTHWEST ON
THURSDAY NIGHT. ALSO, RAIN IS ANTICIPATED TO AFFECT NORTHEASTERN
MARYLAND, DELAWARE AND SOUTHERN NEW JERSEY. THE FORECAST IMPACTS
ON THE NORTHERN EDGE OF THE SYSTEM MAY SHIFT A LITTLE AS WE GET
CLOSER TO THE EVENT.
A MID LEVEL SHORT WAVE TROUGH IS FORECAST TO APPROACH FROM THE
WEST ON THURSDAY NIGHT AND IT SHOULD PASS OVERHEAD EARLY ON
FRIDAY. A SECOND SHORT WAVE IS EXPECTED ON FRIDAY NIGHT. IT SHOULD
BE PRECEDED BY A COLD FRONTAL PASSAGE IN OUR REGION ON FRIDAY
EVENING. THE SYSTEM SHOULD NOT HAVE MUCH MOISTURE ASSOCIATED WITH
IT, SO WE WILL FORECAST FEW CLOUDS AND NO RAINFALL.
SURFACE HIGH PRESSURE WILL BUILD INTO OUR REGION ON FRIDAY NIGHT
AND SATURDAY. THE CENTER OF THE HIGH IS EXPECTED TO PASS OFF THE
COAST LATE ON SATURDAY. THE AIR MASS SHOULD BRING OUR FORECAST
AREA DRY WEATHER CONDITIONS ALONG WITH SLIGHTLY BELOW NORMAL
TEMPERATURES.
WARMTH AND MOISTURE WILL LIKELY BE ON THE INCREASE ON THE BACK
SIDE OF THE HIGH AS WE GET INTO SUNDAY AND MONDAY. MEANWHILE, A
BACK DOOR COLD FRONT MAY PUSH DOWN FROM THE NORTH AND NORTHEAST ON
SUNDAY NIGHT AND MONDAY. WE ARE ANTICIPATING AN INCREASE IN CLOUD
COVER FROM THE SOUTHWEST IN THE DEVELOPING ISENTROPIC LIFT. ALSO,
THERE MAY BE SOME STRATUS IN THE WAKE OF THE BACK DOOR COLD FRONT.
THE TIMING AND PROGRESSION OF BOTH BOUNDARIES REMAINS A LOW
CONFIDENCE FORECAST AT THIS POINT, FIVE AND SIX DAYS REMOVED.
HOWEVER, WE WILL INDICATE THE INCREASE IN CLOUD COVER ALONG WITH A
CHANCE OF SHOWERS ON SUNDAY NIGHT AND MONDAY MORNING, AND A CHANCE
OF SHOWERS AND THUNDERSTORMS ON MONDAY AFTERNOON.
THE AXIS OF A MID LEVEL RIDGE IS FORECAST TO PASS OVERHEAD ON
MONDAY NIGHT. ANOTHER FRONTAL BOUNDARY MAY APPROACH FROM THE
NORTHWEST ON TUESDAY, SO WE WILL CONTINUE TO MENTION THE POTENTIAL
FOR SOME CLOUDS AND A CHANCE OF SHOWERS AND AFTERNOON
THUNDERSTORMS.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
FINALLY TRANSITIONING TO VFR AND GETTING RID OF THE MARINE LAYER
WITH THE SW TO W WINDS. THE COLD FRONT WILL COME THROUGH THIS
EVENING. THE HRRR HI-RES MODELS CONTINUE TO SHOW SOME SHOWERS AND
THUNDERSTORMS MOVING THROUGH WITH THE FRONT. THE TAFS HAVE A
MENTION BETWEEN 21Z-24ZZ. ANY PRECIPITATION WILL BE SCATTERED AT
BEST. AFTER THE COLD FRONT PASSES, ALL TERMINALS WILL SEE VFR
CONDITIONS OVERNIGHT WITH WEST TO NORTHWEST WINDS AROUND 10 KT.
VFR CONDITIONS WILL REMAIN IN PLACE THROUGH TOMORROW, BUT
NORTHWEST WINDS WILL GUST UP TO 25 KT.
OUTLOOK...
WEDNESDAY NIGHT...MAINLY VFR.
THURSDAY AND THURSDAY NIGHT...MAINLY VFR. A CHANCE OF RAIN FROM
KILG, KMIV AND KACY SOUTHWARD.
FRIDAY THROUGH SUNDAY...MAINLY VFR.
&&
.MARINE...
FOR TONIGHT, THE COLD FRONT PASSES THROUGH IN THE EVENING.
NORTHWEST WINDS WILL INCREASE BEHIND THE FRONT. GUSTS SHOULD
SETTLE RIGHT AROUND 20 KT. GUSTS COULD REACH 25 KT. MODELS PEG THE
NORTHERN WATERS AFTER 3 AM. SEAS SHOULD BE NO WORSE THAN 4 FEET.
ISOLATED SHOWERS AND THUNDERSTORMS ARE EXPECTED WITH THE FRONTAL
PASSAGE.
FOR TOMORROW, HIGH PRESSURE BUILDS IN ACROSS AREA WATERS.
NORTHWEST WINDS WILL REMAIN. THOSE ISOLATED 25 KT GUSTS COULD
PERSIST THROUGH ABOUT 9 AM, OTHERWISE EXPECT 10 TO 15 KT. SEAS
WILL BE IN THE 2 TO 4 FOOT RANGE.
OUTLOOK...
WEDNESDAY NIGHT THROUGH SUNDAY...NO MARINE HEADLINES ARE
ANTICIPATED.
&&
.FIRE WEATHER...
FOR TOMORROW, WE`LL SEE WINDS GUSTING TO 25 MPH AND DRY FINE
FUELS ACROSS PORTIONS OF THE REGION, BUT MINIMUM RH`S ARE FORECAST
TO BE IN THE 30-40% RANGE.
ALSO, WIND GUSTS MAY BE AROUND 20 MPH FROM THE NORTHWEST ON
FRIDAY AFTERNOON. RELATIVE HUMIDITY VALUES MAY FALL INTO THE 30 TO
35 PERCENT RANGE AT THAT TIME IN MUCH OF OUR REGION.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...IOVINO
NEAR TERM...KRUZDLO
SHORT TERM...KRUZDLO
LONG TERM...IOVINO
AVIATION...IOVINO/KRUZDLO
MARINE...IOVINO/KRUZDLO
FIRE WEATHER...IOVINO/KRUZDLO
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
911 AM EDT TUE MAY 19 2015
.SYNOPSIS...
A COLD FRONT APPROACHING WESTERN PENNSYLVANIA WILL PASS
THROUGH OUR FORECAST AREA THIS EVENING. WEAK HIGH PRESSURE WILL
FOLLOW FOR WEDNESDAY. LOW PRESSURE ALONG THE NORTH CAROLINA COAST
LATE THURSDAY SHOULD MOVE OUT TO SEA BY FRIDAY. ANOTHER COLD FRONT
IS FORECAST TO ARRIVE FROM THE NORTHWEST FRIDAY AFTERNOON WITH
STRONGER HIGH PRESSURE MOVING TO THE MID ATLANTIC COAST THIS
WEEKEND. A WARM FRONT MAY APPROACH FROM THE SOUTHWEST FOR SUNDAY
NIGHT AND MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SO THE BACKDOOR FRONT THAT PUSHED SOUTH AND WEST ACROSS THE FORECAST
AREA YESTERDAY IS HANGING OUT ACROSS THE DELMARVA EARLY THIS
MORNING. THIS FRONT IS EXPECTED TO LIFT BACK NORTH ACROSS THE
COASTAL PLAIN DURING THE DAY.
THE COLD FRONT TO OUR WEST ISN`T IN ANY HURRY AND PROBABLY WON`T
MAKE IT OFF THE COAST UNTIL SOME TIME THIS EVENING. THE EARLIER
THINKING WAS THIS AFTERNOON.
THE FOG AND LOW CLOUDS WILL CONTINUE TO LESSEN OR DISSIPATE AS THE
DAYS PROGRESSES, BUT THE ASSUMPTION IS IMPROVEMENT WILL COMMENCE
DOWN SOUTH FIRST AND UP NORTH LAST. IMPROVEMENT SHOULD COINCIDE WITH
THE WARM FRONT AND IT`S MIGRATION TO THE NORTH. THE HRRR SHOWS WINDS
BECOMING WEST ACROSS THE SOUTHERN 1/2 OF THE CWA BY AROUND 15Z, BUT
NOT AROUND 18-19Z ACROSS THE NORTHEAST COASTAL ZONES.
THE ENTIRE AREA SHOULD HAVE ENOUGH TIME TO EXPERIENCE THESE WESTERLY
WINDS, BUT IF THIS DOESN`T MATERIALIZE FOR EVERYONE, FORECAST
TEMPERATURES WILL BE TOO HIGH FOR PLACES LIKE MONMOUTH COUNTY.
THE GFS ISN`T SHOWING DEEP LAYER MOISTURE TODAY AND THE BEST
INSTABILITY AND SYNOPTIC LIFT/FLOW ARE DECOUPLED. THE BEST SURFACE
BASED INSTABILITY SHOULD RESIDE ACROSS THE DELMARVA THIS AFTERNOON
WHILE THE BEST OVERALL LIFT/DYNAMICS/FLOW WILL BE ACROSS THE NORTH.
WITH THAT SAID, WE WILL CONTINUE WITH THE IDEA THAT OVERALL
CONVECTIVE ORGANIZATION WILL BE ON THE LOWER END AS THE DAY WEARS
ON. STILL, WITH SOME DRY AIR ALOFT, WE COULD SEE SOME DECENT GUSTS
IF THIS AFTERNOON`S THUNDERSTORMS DEVELOP ENOUGH TO TAP INTO THAT
LAYER.
AS FOR THE HIGH TEMPERATURES, WE USED MOSTLY AN EVEN BLEND OF THE
GFS/NAM MOS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
AN UPPER-LEVEL TROUGH IS FORECAST TO START SHARPENING UP ACROSS
SOUTHEASTERN CANADA AND INTO THE NORTHEAST LATER TONIGHT. THIS WILL
DRIVE A COLD FRONT OFFSHORE THIS EVENING AND ANY LINGERING
CONVECTION WILL EITHER DISSIPATE OR MOVE OUT TO SEA. AS A RESULT,
KEPT A MENTION IN FOR A TIME IN THE EVENING BUT QUICKLY TAPER THE
POPS DOWN FROM WEST TO EAST. FOLLOWING THE COLD FRONTAL PASSAGE, CAA
BEGINS TO OVERTAKE THE AREA THROUGH THE NIGHT.
THE PRESSURE GRADIENT SHOULD TIGHTEN SOME THROUGH THE NIGHT AS LOW
PRESSURE TRACKS NORTH OF MAINE AND HIGH PRESSURE BUILDS INTO THE
OHIO VALLEY. THIS ALONG WITH SOME CAA SHOULD PROMOTE SOME MIXING
THROUGH THE NIGHT AND THEREFORE AT LEAST SOME WIND AT THE SURFACE.
THE AIRMASS IS DRYING QUITE A BIT THEREFORE OTHER THAN SOME
STRATOCUMULUS ACROSS THE NORTHWEST ZONES, MOST AREAS SHOULD HAVE A
CLEAR OR MOSTLY CLEAR SKY.
AS FOR THE LOW TEMPERATURES, WE USED A NAM/GFS MOS BLEND WITH SOME
TWEAKS.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
500MB: CONFLUENT WESTERLY FLOW OVERHEAD TO START WEDNESDAY WITH
THE NORTHERN BRANCH SLIPPING SOUTHWARD AND BECOMING DOMINANT WITH
ITS SHORT WAVE PASSAGE FRIDAY AND COOLER THAN NORMAL HEIGHTS. A
VERY WARM RIDGE DEVELOPS ALONG THE EAST COAST SUNDAY THROUGH EARLY
NEXT WEEK.
TEMPERATURES: THE FIRST 18 DAYS HAVE AVERAGED AROUND 7 DEGREES
ABOVE NORMAL. CALENDAR DAY AVERAGES WILL BE BELOW NORMAL WEDNESDAY
THROUGH SUNDAY WITH GREATEST NEGATIVE DEPARTURES ALMOST 10 DEGREES
BELOW NORMAL ON SATURDAY. (AND POSSIBLY THURSDAY IF IT RAINS).
CONSIDERABLE WARMING SHOULD BEGIN AROUND MEMORIAL DAY OR
IMMEDIATELY THEREAFTER.
LONG TERM HAZARDS: LOW PROBABILITY POSSIBLE COUNTRYSIDE SPOTTY
TOUCH OF FROST N OF I-78 THURSDAY MORNING OR MAYBE A SLIGHTLY
GREATER CHANCE SATURDAY MORNING?
FORECAST BASIS: UNLESS OTHERWISE NOTED, A 50 50 BLEND 00Z/19 GFS/NAM
MOS GUIDANCE WEDNESDAY - THURSDAY, 00Z/19 MEX MOS THURSDAY NIGHT AND
FRIDAY, THEN THE 0521Z/19 WPC GRIDDED ELEMENTS OF MAX/MIN TEMP, 12
HOUR POP, 6 HOUR DEWPOINT-SKY-WIND FROM FRIDAY NIGHT THROUGH MONDAY.
THE DAILIES...
WEDNESDAY-WEDNESDAY NIGHT...WEAK HIGH PRESSURE IS EXPECTED TO FOLLOW
THE COLD FRONT AND IT SHOULD BRING DRY WEATHER CONDITIONS AND BELOW
NORMAL TEMPERATURES WITH PARTLY CLOUDY SKIES OVERALL (DIURNAL CU WED
AFTERNOON AND THEN SOME HIGH CLOUDINESS IS POSSIBLE LATE WED NIGHT).
WINDS WEDNESDAY NORTHWEST GUSTY 15-20 MPH. NEARLY CALM AT NIGHT.
TEMPERATURES MAY FALL INTO THE UPPER 30S IN PARTS OF THE POCONOS
REGION AND NORTHWESTERN NEW JERSEY EARLY ON THURSDAY MORNING IF THE
HIGH CLOUD COVER DOES NOT ARRIVE PRIOR TO 09Z/21. IT COULD BE CLOSE
FOR A TOUCH OF LOCALIZED FROST N OF I-78 IN TYPICALLY COLDEST
SPOTS... WALPACK AND PEQUEST NJ AMONG OTHERS? CONFIDENCE: AVERAGE.
THURSDAY...PARTLY CLOUDY OR CONSIDERABLE CLOUDINESS WITH THE APPROACHING
SHORT WAVE AND MODEL DEPENDENT. GENERALLY WEST OR NORTHWEST WIND
GUSTS 15 MPH OR LESS. TEMPERATURES MAY BE FORECAST TOO WARM.
THIS DEPENDENT ON SKYCOVER AND THE NORTHERN EXTENT OF THE RAIN
SHIELD. SINCE THERE IS UNCERTAINTY, THERE IS ALSO BELOW NORMAL
CONFIDENCE IN THE TEMPS AND PROBABILITY OF MEASURABLE RAIN. AT
THIS TIME, THINK THIS THURSDAY FORECAST IS ON THE WARMER SIDE OF
THE ENVELOPE OF SOLUTIONS.
FRIDAY...PARTLY TO MOSTLY SUNNY WITH DIURNAL CU/SC IN THE AFTERNOON. WEST
TO NORTHWEST WIND GUSTY 20 MPH BECOME NEARLY CALM LATE AT NIGHT.
EC HAS -2C AT 850 MB DOWN TO ABOUT I-80. COULD BE A COUNTRYSIDE RISK
OF SPOTTY FROST N OF I-80.
SATURDAY...LOOKS SUNNY! LIGHT WIND.
SUNDAY...INCREASING CLOUDS WITH WARM AIR ADVECTION. SHOWERS POSSIBLE AT NIGHT?
MONDAY...WARMER WITH A CHANCE OF SHOWERS? UNCERTAINTY FOR MEMORIAL
DAY AND ITS STILL POSSIBLE IT WILL BE RAINFREE. IT DOES APPEAR
THAT WAA SHOWERS SHOULD OCCUR SOMETIME SUNDAY OR MONDAY. PLENTY OF
TIME FOR MORE OPTIMISM IN THE MODEL GUIDANCE.
&&
.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
TODAY...IFR/LIFR CEILINGS IMPROVING TO MVFR TOWARD LATE MORNING,
THEN VFR DURING THE AFTERNOON AS A COLD FRONT APPROACHES. AFTER
SOME LIFR FOG EARLIER THIS MORNING, MAINLY MVFR FOG WILL IMPROVE
THROUGH THE MORNING. LIGHT EAST TO SOUTHEAST WINDS, TURNING
TOWARDS THE SOUTH AND SOUTHWEST AROUND 10 KNOTS IN THE AFTERNOON.
SOME SHOWERS AND THUNDERSTORMS /AFTERNOON/ ARE EXPECTED TO OCCUR
AHEAD OF THE COLD FRONT, HOWEVER THESE MAY BE MAINLY SCATTERED.
LOWER CONFIDENCE ON THE TIMING OF IMPROVEMENT TO MVFR/VFR, AND
ALSO SHOWER/THUNDER COVERAGE ESPECIALLY THIS AFTERNOON.
TONIGHT...A FEW SHOWERS OR A THUNDERSTORM EARLY, OTHERWISE VFR. WEST
TO NORTHWEST WINDS MOSTLY 5-15 KNOTS.
OUTLOOK...
WEDNESDAY...VFR. SCT-BKN AOA 5000 FT. NORTHWEST GUSTY 15 TO 20 KT
DURING THE DAY BECOME NEARLY CALM AT NIGHT.
THURSDAY...VFR. SCT-BKN AOA 5000 FT. GENERALLY WEST WIND GUST
UNDER 15 KT. SMALL CHC OF SHOWERS PHL SEWD, ESPECIALLY S DE AND
COASTAL SE NJ.
FRIDAY...VFR SCT-BKN AOA 5000 FT MAY BECOME COMPLETELY CLEAR NIGHT.
WEST-NORTHWEST WIND GUSTY 20 KT SHOULD DIMINISH AT NIGHT.
SATURDAY...VFR NEARLY CLEAR. LIGHT WIND.
&&
.MARINE...
A LIGHT ONSHORE FLOW TO START TODAY WILL VEER TO SOUTH THEN TO
SOUTHWEST AND WEST BY LATE AFTERNOON. A COLD FRONT WILL MOVE THROUGH
THIS EVENING WITH CAA DEVELOPING IN ITS WAKE. THE CONDITIONS ARE
EXPECTED TO BE BELOW SMALL CRAFT ADVISORY CRITERIA TODAY INTO
TONIGHT, HOWEVER THE CAA LATE TONIGHT AND MAINLY TOWARD DAYBREAK
WEDNESDAY MAY ALLOW FOR WIND GUSTS TO NEAR 25 KNOTS. THIS LOOKS
SHORT IN DURATION THOUGH IF IT WERE TO OCCUR. SOME SHOWERS AND
THUNDERSTORMS ARE EXPECTED TODAY INTO TONIGHT AHEAD OF THE COLD
FRONT.
OUTLOOK...
WEDNESDAY...NO SCA HEADLINE ANTICIPATED AT THIS TIME. NW WIND GUSTS
AROUND 20 KT DURING THE DAY DIMINISH AT NIGHT WITH STRONGEST
DAYTIME WIND PROBABLY ALONG THE NEARSHORE WATERS.
THURSDAY....SCA NOT ANTICIPATED AT THIS TIME, THOUGHT KEEPING AN
EYE ON THE NORTH CAROLINA SFC LOW.
FRIDAY....SMALL CHANCE OF SCA FOR NEARSHORE WEST TO NORTHWEST WIND
GUSTS NEAR 25 KT DURING THE DAY DIMINISHING AT NIGHT.
SATURDAY...NO MARINE HEADLINE ANTICIPATED.
&&
.FIRE WEATHER...
WIND GUSTS SHOULD BE AROUND 20 MPH FROM THE NORTHWEST ON WEDNESDAY
AFTERNOON. RELATIVE HUMIDITY VALUES MAY FALL TO NEAR 30 PERCENT
ESPECIALLY IN PARTS OF EASTERN PENNSYLVANIA AND NEW JERSEY.
FRIDAY AFTERNOON MAY BE SIMILAR TO WEDNESDAY AFTERNOON.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DRAG/KRUZDLO
NEAR TERM...GORSE/KRUZDLO
SHORT TERM...GORSE
LONG TERM...DRAG
AVIATION...DRAG/GORSE/KRUZDLO
MARINE...DRAG/GORSE
FIRE WEATHER...DRAG
AREA FORECAST DISCUSSION...UPDATE
NWS PEACHTREE CITY GA
742 PM EDT WED MAY 20 2015
.EVENING UPDATE...
UPPER DISTURBANCE PUSHING INTO NW AL IS SPARKING CONVECTION THERE...
WITH ONGOING CONVECTION STILL NOTED ACROSS EAST AND SE AL. THESE
STORMS MAY PUSH INTO THE COLUMBUS AREA BY 9 PM... BUT EXPECT SOME
WEAKENING... SO MAY BE MOSTLY SHOWERS. THE GREATER CONCERN IS THE
CONVECTION TO THE NORTH WHERE HAS BETTER UPPER SHORT WAVE SUPPORT.
THIS CONVECTION WILL LIKELY SPREAD ISOLATED TO POSSIBLY STILL
SCATTERED THUNDERSTORMS INTO NW GA BETWEEN 9-10 PM... THEN SPREAD
ACROSS THE REST OF NORTH GA THROUGH MIDNIGHT AND COULD PERSIST UNTIL
AROUND 2-3 AM THU MORNING. NO SEVERE STORMS ARE EXPECTED... WITH THE
MAIN THREAT BEING OCCASIONAL CLOUD TO GROUND LIGHTNING AND BRIEF
WIND GUSTS TO 35-40MPH OR SO. WILL UP POPS OVER THE NW ZONES AS GET
MORE CONFIDENT THE CONVECTION WILL HOLD TOGETHER... BUT OTHERWISE...
THE CURRENT FORECAST LOOK ON TRACK. 39
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
/ISSUED AT 336 PM EDT WED MAY 20 2015/
MAIN FORECAST CONCERN IS WITH PRECIP POTENTIAL THIS EVENING INTO THE
EARLY MORNING AS A SHORTWAVE AND SOME ENHANCED MOISTURE APPROACHES
THE CWA FROM THE WEST. CURRENTLY A BAND OF SHOWERS AND STORMS IS
PUSHING INTO WESTERN ALABAMA AHEAD OF THIS DISTURBANCE WITH A WEAK
TRANSLATED SFC LOW. WHILE SOME HI-RES SOLUTIONS DO NOT APPEAR TO
SUPPORT THIS HOLDING TOGETHER AND PUSHING INTO WEST GA...SOME
PREVIOUS RAP SOLUTIONS SUPPORTED IT AND WILL NEED TO BE CLOSELY
MONITORED ESPECIALLY IF SOME OUTFLOW BOUNDARIES OR OTHER MESOSCALE
FORCING COMES TO AID. THIS MAY RESULT IN UPPING POPS IN WESTERN
PORTIONS OF THE AREA BY THIS EVENING. STILL SOME MLCAPE NEAR 1000
J/KG AND DECENT DCAPE IN PLACE. IF ANY STORM DEVELOPMENT CAN
MUSTER...THERE COULD STILL BE STRONG DOWNDRAFT WINDS EVEN THOUGH IT
IS A SHEAR DEPRIVED ENVIRONMENT. KEEPING BEST CHANCE POPS MAINLY
NORTH OF I-20 CORRIDOR INTO THE EARLY MORNING WITH THE SHORTWAVE
INFLUENCE.
PROGGED THERMAL PROFILES INDICATE GOOD DRYING OF THE COLUMN FOR
THURSDAY AND NOW BETTER AGREEMENT WITH A NOTABLE CAPPING INVERSION
ABOVE 850 MB. HAVE TRIMMED BACK POPS NOW TO ONLY HAVE A SLIGHT
CHANCE IN THE FAR SOUTHERN TIER FOR THE AFTERNOON...OTHERWISE
LOOKING TO STAY TOO DRY AND STABLE. WINDS LOOK TO BE KICKING IN WITH
THE STRENGTHENING PRESSURE GRADIENT AND AFTERNOON MIXING. WHILE
CURRENTLY LOOKING TO STAY A BIT BELOW CRITERIA...WILL NEED TO KEEP
AN EYE ON TRENDS FOR ANY FIRE DANGER CONCERNS WITH ALREADY DRY FUELS
/THOUGH MAY BE ALTERED WITH AFOREMENTIONED PRECIP CHANCES/. TEMPS
THURSDAY LOOK TO HAVE A STRONG GRADIENT WITH BELOW NORMAL HIGHS IN
THE MID/UPPER 70S FOR THE NW TO THE LOW 90S SE.
BAKER
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
/ISSUED AT 336 PM EDT WED MAY 20 2015/
HAVE MADE A FEW MINOR ADJUSTMENTS TO POP AND WEATHER THROUGH THE
WEEKEND. LATEST LONG TERM MODELS HINT AT A MORE PROMINENT SURFACE
HIGH KEEPING MOISTURE TO THE WEST LARGELY AT BAY THROUGH
SUNDAY...WITH ONLY PORTIONS OF WESTERN AND NORTHERN GEORGIA AT
RISK FOR AN ISOLATED STORM. HAVE SCALED POPS BACK SOMEWHAT AS A
RESULT.
31
PREV DISCUSSION... /ISSUED 424 AM EDT WED MAY 20 2015/
LONG TERM PERIOD BEGINS A BIT DRIER AS THE FRONTAL SYSTEM WILL BE
SOUTH AND EAST OF THE AREA. HIGH PRESSURE BUILDING IN FROM THE
NORTHERN PLAINS AND MID WESTERN STATES BECOMES CENTERED OFF THE
MID ATLANTIC COAST AND STAYS THERE THROUGH THE WEEKEND. THIS RIDGE
CONTINUES TO ROTATE AND KEEPS THE DEEPER MOISTURE NORTH AND WEST
OF THE REGION THROUGH THE BEGINNING OF NEXT WEEK. THERE IS STILL
SOME MID AND UPPER LEVEL MOISTURE AROUND THE AREA SO WILL KEEP
SLIGHT CHANCE DIURNALLY DRIVEN POPS IN THE FORECAST DAYS 3-5. BY
TUESDAY THE RIDGE IS BEGINNING TO WEAKEN AND TRANSITION INTO MORE
OF A BERMUDA LIKE RIDGE. THIS WILL ALLOW DEEPER MOISTURE TO MOVE
IN FROM THE WEST ASSOCIATED WITH A WEAKENING FRONTAL BOUNDARY.
LOOKING AT INSTABILITIES INCREASING A BIT TUESDAY/WEDNESDAY ALONG
WITH PWS SO WILL INCREASE TO CHANCE POPS DAYS 6 AND 7.
01
&&
.AVIATION...
00Z UPDATE...
UPPER DISTURBANCE WILL SPREAD SCATTERED SHOWERS AND A FEW
THUNDERSTORMS INTO THE ATLANTA TAF SITES BETWEEN 02-06Z THU... WITH
MID LEVEL CIGS EXPECTED BY 01-02Z. MOS GUIDANCE IS STILL SHOWING A
CHANCE OF MVFR CIGS AT ATL AROUND 09-15Z THU MORNING. THESE SHOULD
SCT BY 15Z THU WITH FEW-SCT050 EXPECTED THU AFTERNOON. WINDS MAINLY
WNW 3-6 KTS TONIGHT...THEN INCREASE TO 10-12 KTS BY 15-16Z THU WITH
OCCASIONAL HIGHER GUSTS OF 18-22 KTS EXPECTED BY 16-18Z THU. THE
GUSTS SHOULD END BY 00-02Z FRI.
//ATL CONFIDENCE...00Z UPDATE...
MEDIUM ON LATE EVENING CONVECTION BEING THUNDERSTORMS AND MVFR CIGS
BY 09Z. HIGH ON ALL ELSE.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 66 85 56 81 / 20 10 10 5
ATLANTA 67 80 58 80 / 30 10 5 5
BLAIRSVILLE 61 74 48 74 / 30 20 10 5
CARTERSVILLE 64 79 53 79 / 30 10 5 5
COLUMBUS 70 88 61 84 / 10 10 10 5
GAINESVILLE 65 80 55 78 / 30 10 10 5
MACON 67 89 59 85 / 20 10 10 5
ROME 65 77 52 79 / 40 10 10 5
PEACHTREE CITY 65 83 54 81 / 20 10 5 5
VIDALIA 71 92 65 86 / 30 20 10 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BAKER
LONG TERM....31
AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
327 AM EDT TUE MAY 19 2015
.SYNOPSIS...
EXPECT SCATTERED MAINLY AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS TODAY AHEAD OF A WEAK FRONT THAT WILL CROSS THE AREA
TONIGHT. THE FRONT WILL STALL JUST TO OUR SOUTH
WEDNESDAY. AN UPPER DISTURBANCE AND SURFACE WAVE WILL MOVE
THROUGH THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
MORNING WATER VAPOR IMAGERY IS SHOWING THE UPPER RIDGE AXIS BREAKING
DOWN AS IT GIVES WAY TO SHORTWAVE ENERGY MOVING THROUGH THE
OHIO/MISSISSIPPI VALLEYS. SURFACE ANALYSIS INDICATES BROAD HIGH
PRESSURE ACROSS THE CAROLINAS AND SOUTHEAST WITH A COLD FRONT
EXTENDING FROM NEAR DETROIT SOUTHWESTWARD TO SOUTHERN ILLINOIS INTO
NORTHERN TEXAS. EARLIER CONVECTION HAS DIMINISHED WITH THE LOSS OF
HEATING AND THE DEBRIS CLOUDS ASSOCIATED WITH THAT CONVECTION ARE
ALSO DIMINISHING WHICH SHOULD ALLOW FOR SOME SUNSHINE THIS MORNING.
THE COLD FRONT OVER THE OHIO VALLEY WILL CONTINUE TO PUSH EASTWARD
TODAY AS SHORTWAVE ENERGY PUSHING INTO NEW ENGLAND BY THIS EVENING
AND THE COLD FRONT CROSSES OUR REGION. PWAT VALUES INCREASE TO
NEARLY 1.8 JUST AHEAD OF THE FRONT THIS AFTERNOON PROVIDING PLENTY
OF MOISTURE FOR CONVECTION WHILE A PRE-FRONTAL SURFACE TROUGH ALSO
COULD PROVIDE A FOCUS FOR CONVECTION. SOME LIMITING FACTORS TODAY
INCLUDE WEAK CONVERGENCE FORECAST ALONG THE FRONT AS WINDS AHEAD OF
THE FRONT ALREADY WILL BE FROM THE WEST AND 850MB FLOW IS ALSO
WESTERLY COMING ACROSS THE MOUNTAINS WHICH USUALLY INHIBITS
WIDESPREAD CONVECTION. MODERATE INSTABILITY IS FORECAST WITH LIFTED
INDEX VALUES AROUND -5C BUT SHEAR CONTINUES TO BE WEAK. MOST OF THE
NWP GUIDANCE INCLUDING THE HIGH RESOLUTION MODELS FOCUS THE
CONVECTION ACROSS SOUTHERN AND CENTRAL NORTH CAROLINA AND DEVELOP IT
EASTWARD THROUGH THE AFTERNOON THEN EXPANDING TO THE COASTAL REGIONS
OF NC/SC. THIS LOGICALLY MAKES SENSE AS THE BETTER UPPER LEVEL
SUPPORT WILL BE FURTHER TO THE NORTH AND THE SEA BREEZE COULD BE
ANOTHER TRIGGER FOR CONVECTION OR ENHANCE CONVECTION MOVING INTO THE
COASTAL AREAS LATE IN THE DAY. FOR THESE REASONS WILL CONTINUE WITH
ONLY CHANCE POPS WITH THE HIGHEST POPS ACROSS THE NORTHERN AND
EASTERN MIDLANDS AND PEE DEE REGION...AND COVERAGE COULD BECOME A
BIT MORE WIDESPREAD IF STORMS BECOME MULTICELLULAR WITH NEW
CONVECTION FORMING ON OUTFLOW BOUNDARIES. CONVECTION MAY LINGER
INTO THE EVENING HOURS ALONG AND AHEAD OF THE FRONT ACROSS THE
EASTERN AND SOUTHERN MIDLANDS BUT SHOULD END BY 06Z ACROSS THE AREA.
TEMPERATURES TODAY WILL AGAIN BE WARM IN THE UPPER 80S TO LOWER 90S
WITH LOWS TONIGHT RANGING FROM THE MID 60S NORTHERN MIDLANDS TO
LOWER 70S SOUTHEASTERN MIDLANDS.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
MODELS INDICATE THE FRONT WILL STALL NEAR THE CSRA AND SOUTHERN
MIDLANDS OR JUST TO THE SOUTH WEDNESDAY. DIURNAL SHOWER AND
THUNDERSTORM ACTIVITY WILL FAVOR THOSE REGIONS. DRIER AIR
ENTERING THE NORTHERN FA BEHIND THE FRONT EXPECTED TO PRECLUDE
CONVECTION THERE. MODELS DEVELOP A SURFACE WAVE OF LOW PRESSURE
ALONG THE STALLED FRONT...IN RESPONSE TO APPROACHING UPPER
ENERGY...WHICH SLOWLY TRACKS EAST ACROSS THE FA LATE WEDNESDAY
NIGHT AND THURSDAY. ACCEPTED GUIDANCE BLEND OF CHANCE POPS.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
MODELS REMAIN IN GOOD AGREEMENT WITH SOME MINOR TIMING AND
INTENSITY DIFFERENCES THROUGH THE WEEKEND AND INTO NEXT WEEK.
ON FRIDAY HIGH PRESSURE CROSSING THE CENTRAL GREAT LAKES WILL
USHER SLIGHTLY COOLER AND DRIER AIR SOUTHWARD AND INTO THE REGION.
THE HIGH WILL TRACK OFF THE NEW ENGLAND COAST ON SATURDAY ALLOWING
MOIST SOUTHERLY FLOW TO BEGIN RETURNING TO THE REGION. THIS WILL
ALLOW LOW CHANCES OF MAINLY DIURNAL SHOWERS AND THUNDERSTORMS TO
RETURN TO THE AREA. TEMPERATURES THROUGH THE LONG TERM WILL BE
NEAR TO SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS EXPECTED THROUGH THE PERIOD EXCEPT RESTRICTIONS IN
FOG AT AGS.
EVENING CONVECTION HAS COME TO AN END BUT RAIN COOLED AIR HAS
ALLOWED FOG TO DEVELOP AT AGS AND WILL LIKELY CONTINUE TO BE AN
ISSUE THROUGH 13Z WITH VSBYS RANGING BETWEEN 3SM AND 1/2SM.
ELSEWHERE...A WEAK LOW LEVEL JET IS HELPING TO KEEP THE SURFACE
WINDS UP JUST ENOUGH TO PREVENT FOG DEVELOPMENT THUS FAR. DO NOT
EXPECT MUCH FOG OUTSIDE OF AGS ALTHOUGH HRRR GUIDANCE AND NAM MOS
HINTING AT SOME POSSIBLE STRATUS CLOUD FORMATION AFTER 09Z IN
AREAS THAT RECEIVED RAINFALL SO HAVE INCLUDED A BRIEF PERIOD OF
MVFR CIGS TO ACCOUNT FOR THAT AT CAE/CUB.
HEATING AND SOME CONVERGENCE ASSOCIATED WITH A PRE-FRONTAL TROUGH
AND AN APPROACHING COLD FRONT SHOULD SUPPORT THUNDERSTORMS DURING
THE DAY TUESDAY. THE MODELS DISPLAY THE GREATER CONVERGENCE AND
INSTABILITY NORTH AND EAST OF THE TERMINALS AND WE EXPECT
SCATTERED THUNDERSTORM COVERAGE. THE CHANCE OF THUNDERSTORMS IS
TOO LOW TO INCLUDE IN THE TERMINAL FORECASTS AT THIS TIME THOUGH
OGB IS PROBABLY MOST LIKELY TO BE IMPACTED LATE THIS AFTERNOON
INTO EARLY EVENING.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN MAINLY
SCATTERED AFTERNOON AND EVENING THUNDERSTORMS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
155 AM EDT TUE MAY 19 2015
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO WEAKEN AND SHIFT EAST TODAY WHILE
ATMOSPHERIC MOISTURE INCREASES OVER THE REGION. A WEAK FRONT WILL
CROSS THE AREA THIS AFTERNOON AND EVENING BRINGING SHOWERS AND
THUNDERSTORMS. THE FRONT WILL REMAIN JUST SOUTH OF THE REGION
THROUGH THE WEEKEND WITH PARTLY CLOUDY SKIES AND LOW CHANCES OF
MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /THROUGH 6AM/...
EVENING CONVECTION CONTINUES TO WANE WITH THE STABILIZATION OF THE
ATMOSPHERE. HIGH PRESSURE OFF THE SOUTHEAST COAST WILL WEAKEN
TONIGHT. MOISTURE WILL REMAIN ELEVATED WITH PWAT VALUES AROUND 1.6
INCHES AHEAD OF AN APPROACHING FRONTAL BOUNDARY. UPPER LEVEL
CLOUDS AND HIGH DEW POINTS WILL KEEP LOWS ABOVE NORMAL...IN THE
UPPER 60S.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
UPPER LEVEL RIDGE WILL BEGIN THE DAY ALONG THE COAST AND CONTINUE
TRACKING EASTWARD INTO THE ATLANTIC BASIN TUESDAY WITH A ZONAL
PATTERN FOR TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. THE WEAK
FRONTAL BOUNDARY WILL MOVE THROUGH THE FORECAST AREA DURING THE
AFTERNOON HOURS TRIGGERING SHOWERS AND THUNDERSTORMS FOR THE LATE
MORNING THROUGH EVENING HOURS. PWAT VALUES WILL BE BETWEEN 1.6 AND
1.7 INCHES THROUGH MUCH OF TUESDAY AND WITH WEAK FLOW ALOFT COULD
LEAD TO SOME LOCALLY HEAVY RAINFALL. ONE CONCERN WILL BE THE LOW
LEVEL WINDS WHICH WILL TURN NORTHWESTERLY DURING THE LATE MORNING
AND EARLY AFTERNOON HOURS...WITH THIS DOWNSLOPING WIND CONVECTION
IS TYPICALLY SUPPRESSED ESPECIALLY ACROSS THE WESTERN MIDLANDS. AS
SUCH HAVE ADJUSTED POPS TO ACCOUNT FOR THE DOWNSLOPING WITH HIGHER
POPS IN THE CENTRAL AND EASTERN MIDLANDS. FRONT WILL STALL JUST
SOUTH OF THE AREA TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. THIS WILL
KEEP MOISTURE AND INSTABILITY GREATEST OVER THE SOUTHERN MIDLANDS
AND CSRA SO HAVE KEPT SLIGHT CHANCE POPS FOR THOSE AREAS TUESDAY.
SEVERE THREAT THROUGH THE SHORT TERM REMAINS LOW WITH THE MAIN
POTENTIAL FROM DAMAGING WIND GUSTS. DAYTIME HIGH TEMPERATURES WILL
BE IN THE UPPER 80S TO LOWER 90S WITH OVERNIGHT LOWS IN THE MIDDLE
TO UPPER 60S.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
MODELS REMAIN IN GOOD AGREEMENT WITH SOME MINOR TIMING AND
INTENSITY DIFFERENCES THROUGH THE WEEKEND AND INTO NEXT WEEK.
FRONTAL BOUNDARY WILL CONTINUE TO SHEAR APART SOUTH OF THE
FORECAST AREA WITH A WEAK AREA OF LOW PRESSURE EXPECTED TO CROSS
THE REGION THURSDAY AND THURSDAY NIGHT. ON FRIDAY HIGH PRESSURE
CROSSING THE CENTRAL GREAT LAKES WILL USHER SLIGHTLY COOLER AND
DRIER AIR SOUTHWARD AND INTO THE REGION. THE HIGH WILL TRACK OFF
THE NEW ENGLAND COAST ON SATURDAY ALLOWING MOIST SOUTHERLY FLOW TO
BEGIN RETURNING TO THE REGION. THIS WILL ALLOW LOW CHANCES OF
MAINLY DIURNAL SHOWERS AND THUNDERSTORMS TO RETURN TO THE AREA.
TEMPERATURES THROUGH THE LONG TERM WILL BE NEAR TO SLIGHTLY ABOVE
NORMAL.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS EXPECTED THROUGH THE PERIOD EXCEPT RESTRICTIONS IN
FOG AT AGS.
EVENING CONVECTION HAS COME TO AN END BUT RAIN COOLED AIR HAS
ALLOWED FOG TO DEVELOP AT AGS AND WILL LIKELY CONTINUE TO BE AN
ISSUE THROUGH 13Z WITH VSBYS RANGING BETWEEN 3SM AND 1/2SM.
ELSEWHERE...A WEAK LOW LEVEL JET IS HELPING TO KEEP THE SURFACE
WINDS UP JUST ENOUGH TO PREVENT FOG DEVELOPMENT THUS FAR. DO NOT
EXPECT MUCH FOG OUTSIDE OF AGS ALTHOUGH HRRR GUIDANCE AND NAM MOS
HINTING AT SOME POSSIBLE STRATUS CLOUD FORMATION AFTER 09Z IN
AREAS THAT RECEIVED RAINFALL SO HAVE INCLUDED A BRIEF PERIOD OF
MVFR CIGS TO ACCOUNT FOR THAT AT CAE/CUB.
HEATING AND SOME CONVERGENCE ASSOCIATED WITH A PRE-FRONTAL TROUGH
AND AN APPROACHING COLD FRONT SHOULD SUPPORT THUNDERSTORMS DURING
THE DAY TUESDAY. THE MODELS DISPLAY THE GREATER CONVERGENCE AND
INSTABILITY NORTH AND EAST OF THE TERMINALS AND WE EXPECT
SCATTERED THUNDERSTORM COVERAGE. THE CHANCE OF THUNDERSTORMS IS
TOO LOW TO INCLUDE IN THE TERMINAL FORECASTS AT THIS TIME THOUGH
OGB IS PROBABLY MOST LIKELY TO BE IMPACTED LATE THIS AFTERNOON
INTO EARLY EVENING.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN MAINLY
SCATTERED AFTERNOON AND EVENING THUNDERSTORMS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1249 PM CDT TUE MAY 19 2015
.UPDATE...
ISSUED AT 1037 AM CDT TUE MAY 19 2015
SURFACE HIGH PRESSURE CENTERED OVER THE NORTHERN PLAINS WILL
CONTINUE TO SHIFT EASTWARD TODAY BRINGING LIGHT NORTHERLY WINDS
AND CONTINUED ADVECTION OF COOL AND RELATIVELY DRY AIR INTO
CENTRAL IL. GENERAL SUBSIDENCE ALOFT IS INDICATED BY MODEL
FORECASTS AND CURRENT WATER VAPOR IMAGERY, HOWEVER A BAND OF LOW
CLOUD OVER PORTIONS OF IL MAINLY NORTH OF I-72 PERSISTS THIS
MORNING. MODEL TIME-HEIGHT PLOTS NOW INDICATE THIS LAYER FAIRLY
WELL AND HRRR HALTS THE PROGRESS OF THE BAND AROUND THE CURRENT
LOCATION. SURFACE HEATING WILL TEND TO RAISE THE CEILING HEIGHT
THROUGH THE AFTERNOON...BUT ENOUGH MOISTURE SHOULD PERSIST THAT
THE LAYER SHOULD TRANSITION INTO A SCATTERED SHALLOW CUMULUS LAYER
AROUND 4000-5000 FEET. FORECAST IS MORE OR LESS ON TRACK, BUT HAVE
MADE SOME MODIFICATIONS TO CLOUD COVER THROUGH THE AFTERNOON TO
BETTER DEPICT THE SITUATION.
&&
.SHORT TERM...(TODAY)
ISSUED AT 331 AM CDT TUE MAY 19 2015
CANADIAN HIGH PRESSURE WILL BEGIN TO BUILD INTO CENTRAL AND
SOUTHEAST ILLINOIS TODAY, ACCOMPANIED BY A CONTINUED FEED OF
COOLER/DRIER AIR IN THE WAKE OF YESTERDAY`S COLD FRONT. THIS
SCENARIO SUPPORTS A DRY DAY, WITH AFTERNOON HIGH TEMPERATURES
MAINLY IN THE 60S.
ONE FLY IN THE OINTMENT, ONE THAT MAY IMPACT TEMPERATURES ACROSS
NORTHERN PORTIONS OF THE FORECAST AREA, IS A LARGE AREA OF WRAP-
AROUND CLOUDINESS THAT HAS STARTED TO SINK INTO FAR NORTHERN
PORTIONS OVER THE FORECAST AREA OVER THE PAST FEW HOURS. NONE OF THE
MODEL GUIDANCE HAS A VERY GOOD HANDLE ON THE CURRENT SOUTHERN EXTENT
OF THE CLOUD SHIELD, OR IN MANY CASES EVEN INDICATES IT AT ALL. AT
THIS POINT, HAVE USED SIMPLE EXTRAPOLATION OF THE CURRENT CLOUD
SHIELD INTO MID-MORNING. THEN, AS DIURNAL MIXING GETS GOING, HAVE
ALLOWED THE SOUTHERN EDGE OF THE CLOUD SHIELD TO MIX-OUT/ERODE AND
BE NORTH OF THE AREA BY MIDDAY. SO, BASICALLY, MUCH OF THE FORECAST
AREA ALONG/NORTH OF I-74 WILL BE CLOUDY TO START THE DAY, GRADUALLY
BECOMING MOSTLY SUNNY BY AFTERNOON.
.LONG TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 331 AM CDT TUE MAY 19 2015
CANADIAN HIGH PRESSURE WILL BE SPRAWLED NORTH OF IL ACROSS WI
TONIGHT KEEPING CENTRAL IL DRY. MID/HIGH CLOUDS TO INCREASE FROM THE
WEST DURING TONIGHT AHEAD OF NEXT WEATHER SYSTEM EJECTING INTO THE
CENTRAL PLAINS. LOWS TONIGHT IN THE MID TO UPPER 40S WITH COOLEST
READINGS OVER EAST CENTRAL IL WHERE CLOUDS MOVE IN LATER.
SHORT WAVE TO WEAKEN AS IT EJECTS INTO CENTRAL IL WED AFTERNOON AND
LIKELY SPREADING LIGHT RAIN SHOWERS EAST ACROSS CENTRAL AND SE IL
DURING THE DAY WED. SPC KEEPS CHANCES OF THUNDER SOUTH OF I-64 OVER
SOUTHERN IL ON WED BUT KEPT SLIGHT CHANCE OF THUNDER WED AFTERNOON
OVER SW CWA. NE FLOW AROUND HIGH PRESSURE OVER THE GREAT LAKES WILL
TRY TO BRING DRIER AIR INTO NE CWA WHERE RAINFALL AMOUNTS ONLY ONE
TO TWO TENTHS WHILE A QUARTER TO A THIRD OF AN INCH OF RAIN SW CWA.
BEST RAIN CHANCES SHIFT INTO SE IL WED EVENING WHILE THE IL RIVER
VALLEY DRIER OUT AS WEAKENING SYSTEM GETS SHUNTED TO THE SE AS
ANOTHER HIGH PRESSURE SYSTEM NOSES INTO IL FROM THE CENTRAL PLAINS.
WENT A FEW DEGREES COOLER THAN MET/MAV GUIDANCE FOR HIGHS WED
ESPECIALLY CENTRAL AND WESTERN AREAS WHERE HIGHER CHANCES OF
RAIN WITH MID TO UPPER 50S NORTH AND LOWER 60S IN SOUTHEAST IL.
HIGH PRESSURE SETTLES INTO MO THU AFTERNOON INTO THU NIGHT AND TO
BRING DRY WEATHER TO IL WITH RETURN OF PARTLY TO MOSTLY SUNNY SKIES
BY THU AFTERNOON. MILDER HIGHS IN THE MID TO UPPER 60S BUT STILL
BELOW NORMAL HIGHS IN THE MID 70S. LOWS THU NIGHT IN THE MID TO
UPPER 40S. A NICE DAY IN STORE FRIDAY AS HIGH PRESSURE SETTLES OVER
IL WITH AMPLE SUNSHINE...FAIRLY LIGHT WINDS AND HIGHS IN THE LOWER
70S. DRY CONDITIONS CONTINUE FRIDAY NIGHT ACROSS IL WITH LOWS IN THE
LOW TO MID 50S.
MOST OF CENTRAL AND ESPECIALLY EASTERN IL APPEAR TO STAY DRY YET ON
SATURDAY WITH INCREASING CLOUDS AND HIGHS IN THE MID 70S AS HIGH
PRESSURE SLIPS OFF THE MID ATLANTIC COAST BY SUNSET SATURDAY AND
UPPER LEVEL RIDGE INTO IL. HAVE SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS SAT AFTERNOON OVER WEST CENTRAL IL WHILE BETTER
CHANCES OF SHOWERS AND THUNDERSTORMS TO SPREAD NE ACROSS CENTRAL IL
DURING SAT NIGHT AND SUNDAY WITH SHORT WAVES EJECTING NE FROM THE
LARGE UPPER LEVEL TROF OVER THE ROCKIES. INCREASING GULF MOISTURE
WITH SOUTHERLY FLOW TO PROVIDE GOOD CHANCES OF SHOWERS AND
THUNDERSTORMS SUNDAY INTO MONDAY AND TO EVEN LINGER INTO NEXT
TUESDAY. A WARMER AND MORE HUMID STRETCH OF WEATHER FROM SUNDAY
THROUGH TUESDAY WITH HIGHS IN THE UPPER 70S (LOWER 80S IN SOUTHEAST
IL) AND DEWPOINTS IN THE 60S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1249 PM CDT TUE MAY 19 2015
VFR CONDITIONS OVER MOST OF CENTRAL/SE IL THIS AFTERNOON...WITH
LINGERING MVFR CEILINGS KPIA-KBMI NORTHWARD. WITH DAYTIME
HEATING...CEILINGS SHOULD RAISE ABOVE MVFR THRESHOLDS WITHIN A FEW
HOURS ACROSS THE AREA...ALTHOUGH AREAS OF CLOUD COVER SCT-
BKN035-050 WILL LINGER THROUGH THE AFTERNOON ESPECIALLY KPIA-KBMI
NORTHWARD. LOW LEVEL CLOUD COVER DIMINISHING
EVENING/OVERNIGHT...THEN INCREASING LOW CLOUD COVER AND RAIN
SHOWERS AFTER 12Z. MODEL TIME-HEIGHT SECTIONS AND GUIDANCE
GENERALLY DEPICT CEILINGS REMAINING IN VFR RANGE UNTIL 18Z SO HAVE
INTRODUCED VCSH WITH CIGS/VSBY VFR STARTING 14-16Z. WINDS NNW
8-12 KTS DECREASING OVERNIGHT...THEN BECOMING ENE AROUND 10 KTS
AFTER 15Z WEDNESDAY.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...ONTON
SHORT TERM...BAK
LONG TERM...07
AVIATION...ONTON
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1037 AM CDT TUE MAY 19 2015
.UPDATE...
ISSUED AT 1037 AM CDT TUE MAY 19 2015
SURFACE HIGH PRESSURE CENTERED OVER THE NORTHERN PLAINS WILL
CONTINUE TO SHIFT EASTWARD TODAY BRINGING LIGHT NORTHERLY WINDS
AND CONTINUED ADVECTION OF COOL AND RELATIVELY DRY AIR INTO
CENTRAL IL. GENERAL SUBSIDENCE ALOFT IS INDICATED BY MODEL
FORECASTS AND CURRENT WATER VAPOR IMAGERY, HOWEVER A BAND OF LOW
CLOUD OVER PORTIONS OF IL MAINLY NORTH OF I-72 PERSISTS THIS
MORNING. MODEL TIME-HEIGHT PLOTS NOW INDICATE THIS LAYER FAIRLY
WELL AND HRRR HALTS THE PROGRESS OF THE BAND AROUND THE CURRENT
LOCATION. SURFACE HEATING WILL TEND TO RAISE THE CEILING HEIGHT
THROUGH THE AFTERNOON...BUT ENOUGH MOISTURE SHOULD PERSIST THAT
THE LAYER SHOULD TRANSITION INTO A SCATTERED SHALLOW CUMULUS LAYER
AROUND 4000-5000 FEET. FORECAST IS MORE OR LESS ON TRACK, BUT HAVE
MADE SOME MODIFICATIONS TO CLOUD COVER THROUGH THE AFTERNOON TO
BETTER DEPICT THE SITUATION.
&&
.SHORT TERM...(TODAY)
ISSUED AT 331 AM CDT TUE MAY 19 2015
CANADIAN HIGH PRESSURE WILL BEGIN TO BUILD INTO CENTRAL AND
SOUTHEAST ILLINOIS TODAY, ACCOMPANIED BY A CONTINUED FEED OF
COOLER/DRIER AIR IN THE WAKE OF YESTERDAY`S COLD FRONT. THIS
SCENARIO SUPPORTS A DRY DAY, WITH AFTERNOON HIGH TEMPERATURES
MAINLY IN THE 60S.
ONE FLY IN THE OINTMENT, ONE THAT MAY IMPACT TEMPERATURES ACROSS
NORTHERN PORTIONS OF THE FORECAST AREA, IS A LARGE AREA OF WRAP-
AROUND CLOUDINESS THAT HAS STARTED TO SINK INTO FAR NORTHERN
PORTIONS OVER THE FORECAST AREA OVER THE PAST FEW HOURS. NONE OF THE
MODEL GUIDANCE HAS A VERY GOOD HANDLE ON THE CURRENT SOUTHERN EXTENT
OF THE CLOUD SHIELD, OR IN MANY CASES EVEN INDICATES IT AT ALL. AT
THIS POINT, HAVE USED SIMPLE EXTRAPOLATION OF THE CURRENT CLOUD
SHIELD INTO MID-MORNING. THEN, AS DIURNAL MIXING GETS GOING, HAVE
ALLOWED THE SOUTHERN EDGE OF THE CLOUD SHIELD TO MIX-OUT/ERODE AND
BE NORTH OF THE AREA BY MIDDAY. SO, BASICALLY, MUCH OF THE FORECAST
AREA ALONG/NORTH OF I-74 WILL BE CLOUDY TO START THE DAY, GRADUALLY
BECOMING MOSTLY SUNNY BY AFTERNOON.
.LONG TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 331 AM CDT TUE MAY 19 2015
CANADIAN HIGH PRESSURE WILL BE SPRAWLED NORTH OF IL ACROSS WI
TONIGHT KEEPING CENTRAL IL DRY. MID/HIGH CLOUDS TO INCREASE FROM THE
WEST DURING TONIGHT AHEAD OF NEXT WEATHER SYSTEM EJECTING INTO THE
CENTRAL PLAINS. LOWS TONIGHT IN THE MID TO UPPER 40S WITH COOLEST
READINGS OVER EAST CENTRAL IL WHERE CLOUDS MOVE IN LATER.
SHORT WAVE TO WEAKEN AS IT EJECTS INTO CENTRAL IL WED AFTERNOON AND
LIKELY SPREADING LIGHT RAIN SHOWERS EAST ACROSS CENTRAL AND SE IL
DURING THE DAY WED. SPC KEEPS CHANCES OF THUNDER SOUTH OF I-64 OVER
SOUTHERN IL ON WED BUT KEPT SLIGHT CHANCE OF THUNDER WED AFTERNOON
OVER SW CWA. NE FLOW AROUND HIGH PRESSURE OVER THE GREAT LAKES WILL
TRY TO BRING DRIER AIR INTO NE CWA WHERE RAINFALL AMOUNTS ONLY ONE
TO TWO TENTHS WHILE A QUARTER TO A THIRD OF AN INCH OF RAIN SW CWA.
BEST RAIN CHANCES SHIFT INTO SE IL WED EVENING WHILE THE IL RIVER
VALLEY DRIER OUT AS WEAKENING SYSTEM GETS SHUNTED TO THE SE AS
ANOTHER HIGH PRESSURE SYSTEM NOSES INTO IL FROM THE CENTRAL PLAINS.
WENT A FEW DEGREES COOLER THAN MET/MAV GUIDANCE FOR HIGHS WED
ESPECIALLY CENTRAL AND WESTERN AREAS WHERE HIGHER CHANCES OF
RAIN WITH MID TO UPPER 50S NORTH AND LOWER 60S IN SOUTHEAST IL.
HIGH PRESSURE SETTLES INTO MO THU AFTERNOON INTO THU NIGHT AND TO
BRING DRY WEATHER TO IL WITH RETURN OF PARTLY TO MOSTLY SUNNY SKIES
BY THU AFTERNOON. MILDER HIGHS IN THE MID TO UPPER 60S BUT STILL
BELOW NORMAL HIGHS IN THE MID 70S. LOWS THU NIGHT IN THE MID TO
UPPER 40S. A NICE DAY IN STORE FRIDAY AS HIGH PRESSURE SETTLES OVER
IL WITH AMPLE SUNSHINE...FAIRLY LIGHT WINDS AND HIGHS IN THE LOWER
70S. DRY CONDITIONS CONTINUE FRIDAY NIGHT ACROSS IL WITH LOWS IN THE
LOW TO MID 50S.
MOST OF CENTRAL AND ESPECIALLY EASTERN IL APPEAR TO STAY DRY YET ON
SATURDAY WITH INCREASING CLOUDS AND HIGHS IN THE MID 70S AS HIGH
PRESSURE SLIPS OFF THE MID ATLANTIC COAST BY SUNSET SATURDAY AND
UPPER LEVEL RIDGE INTO IL. HAVE SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS SAT AFTERNOON OVER WEST CENTRAL IL WHILE BETTER
CHANCES OF SHOWERS AND THUNDERSTORMS TO SPREAD NE ACROSS CENTRAL IL
DURING SAT NIGHT AND SUNDAY WITH SHORT WAVES EJECTING NE FROM THE
LARGE UPPER LEVEL TROF OVER THE ROCKIES. INCREASING GULF MOISTURE
WITH SOUTHERLY FLOW TO PROVIDE GOOD CHANCES OF SHOWERS AND
THUNDERSTORMS SUNDAY INTO MONDAY AND TO EVEN LINGER INTO NEXT
TUESDAY. A WARMER AND MORE HUMID STRETCH OF WEATHER FROM SUNDAY
THROUGH TUESDAY WITH HIGHS IN THE UPPER 70S (LOWER 80S IN SOUTHEAST
IL) AND DEWPOINTS IN THE 60S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 650 AM CDT TUE MAY 19 2015
LARGE AREA OF MVFR CLOUDS HAS CONTINUED TO SINK SOUTHWARD ACROSS
CENTRAL ILLINOIS OVERNIGHT. KPIA & KBMI HAVE BEEN BENEATH THE
CLOUDS FOR A WHILE, BUT IT NOW LOOKS AS THOUGH ALL LOCAL TERMINALS
WILL BE IMPACTED. NONE OF THE MODEL GUIDANCE HAS HAD A GOOD FEEL
ON THESE CLOUDS AT ALL, AND INITIAL FORECAST IS BASED PARTLY ON
SATELLITE EXTRAPOLATION AND PARTLY ON DIURNAL EFFECTS THAT SHOULD
TEND TO ERODE THE SOUTHERN EDGE OF THE CLOUD FIELD. SO, HAVE SKIES
SCATTERING OUT AGAIN THIS AFTERNOON, WITH VFR CONDTIONS THEN
PERSISTING THROUGH THE REST OF THE PERIOD. HOWEVER, CONFIDENCE IN
THE EXACT TIME OF THE CLEARING IS NOT HIGH. NORTHWEST WINDS WILL
CONTINUE TO DIMINISH AS HIGH PRESSURE BUILDS INTO THE AREA,
BECOMING VARIABLE BY TONIGHT.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...ONTON
SHORT TERM...BAK
LONG TERM...07
AVIATION...BAK
AREA FORECAST DISCUSSION
NWS GOODLAND KS
541 PM MDT WED MAY 20 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 153 PM MDT WED MAY 20 2015
ACROSS THE FORECAST AREA THIS AFTERNOON...MOSTLY CLOUDY/CLOUDY SKY
CONDITIONS PERSIST ACROSS THE ENTIRE FORECAST AREA...ALTHOUGH SOME
THINNING OF THE LOW LEVEL CLOUD DECK IN PAST COUPLE HOURS HAS
ALLOWED TEMPS TO RISE A FEW DEGREES. THIS HAS PUT THE TRI STATE
REGION MAINLY IN THE MID 40S...WITH SOME NEAR 50F ACROSS FAR EASTERN
AND SOUTHERN ZONES.
GOING INTO TONIGHT...LOW LEVEL MOISTURE PROFILES FROM LATEST MODEL
GUIDANCE...COMBINED WITH SURFACE RIDGE NOSING FURTHER SOUTHWARD INTO
THE LOWER PORTION OF THE PLAINS...IS GOING TO KEEP LOW CLOUD DECK
OVER THE CWA FOR THE OVERNIGHT PERIOD WITH NORTHERLY FLOW BECOMING
SSE BY THURSDAY MORNING. MID/UPPER LEVELS DRY AS H5 RIDGE NOSES IN
OVER ROCKIES...GIVING WESTERLY FLOW AT 500 MB.
GOING INTO THURSDAY...RIDGE JUST TO OUR EAST WITH MODELS BRINGING
H5/H7 CUTOFF LOW INTO THE ROCKIES. SSE FLOW OVER MUCH OF THE CWA
WILL ALLOW FOR GULF MOISTURE TO FUNNEL UP NORTHWARD INTO THE WESTERN
PORTION OF THE AREA WHERE MODELS HAVE WEAK LEE-SIDE TROUGH DEVELOP.
SOME -RW DOES DEVELOP EARLY OVER THE CENTRAL ROCKIES AND MEANDERS
SLOWLY EASTWARD THRU THE DAY...SLICING INTO PORTION OF THE WESTERN
CWA. RIDGE FAIRLY STAGNANT BUT DOES HINT ENOUGH LOW LEVEL MOISTURE
TO FEED INTO CWA...WITH TROUGH SLIDING EAST SOME IN TANDEM. THIS
COULD TRIGGER A FEW LIGHT -RW WITH FOCUS OVER EASTERN COLORADO
ALTHOUGH SOME SPOTS IN NW KANSAS COULD SEE A SPOT SHOWER. HAVE KEPT
POPS IN SLIGHT CHANCE CATEGORY FOR THE ENTIRE DAY...BUT CENTRAL
EASTERN HALF MAINLY DRY. PLACEMENT OF RIDGE TOMORROW WILL AFFECT
HIGHS FOR THE ENTIRE AREA. WARMEST WILL BE EAST WHERE BEST CHANCES
FOR LESS AREAL CLOUD COVERAGE...COOLER WEST...BUT LOOKING FOR LOW TO
MID 60S.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 222 PM MDT WED MAY 20 2015
ANOTHER SLOW-MOVING UPPER TROUGH IN THE SOUTHWESTERN US IS
FORECAST TO IMPACT THE AREA STARTING THURSDAY NIGHT...CONTINUING
THROUGH THIS COMING WEEKEND. THE FIRST SHORT WAVE TROUGH IS
FORECAST TO MOVE ACROSS THE REGION THURSDAY EVENING THROUGH
FRIDAY MORNING AND LIFT NORTH DURING THE DAY. EXPECTING RAIN AND
RAIN SHOWERS WITH THIS BAND OF PRECIPITATION TOMORROW NIGHT AND
MODELS ARE IN FAIR AGREEMENT AS TO TIMING AND AMOUNTS. CURRENT
FORECAST IS THEREFORE MORE SPECIFIC IN TERMS OF PRECIP START
TIMES THURSDAY EVENING ALONG WITH HIGHER POP CONFIDENCE.
THE NEXT IMPULSE LIFTING OUT OF THE SOUTHWEST LOOKS TO ARRIVE SATURDAY
AFTERNOON INTO SATURDAY NIGHT WITH GUIDANCE NOT NEARLY AS
CONSISTENT WITH TIMING AND PLACEMENT OF RAINFALL. FORECAST IS MORE
OF A BROAD BRUSH APPROACH IN TERMS OF POPS AND QPF. RIGHT NOW
THINKING IS THE POTENTIAL FOR SEVERE WEATHER WILL BE LIMITED ON
SATURDAY. AFTER SATURDAY NIGHT...NUMEROUS WEAKER IMPULSES LIFT
NORTHEAST ACROSS THE REGION WITH CHANCES OF SCATTERED SHOWERS AND
THUNDERSTORMS INTO THE MIDDLE OF NEXT WEEK.
FRIDAY AFTERNOON TEMPERATURES WILL CONTINUE BELOW NORMAL WITH
LINGERING CLOUD COVER ASSOCIATED WITH EXITING SHORT WAVE.
TEMPERATURES WILL RETURN CLOSER TO NORMAL IN THE 70S FOR SATURDAY
INTO NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 522 PM MDT WED MAY 20 2015
MAIN CONCERN FOR NEXT 24 HOURS WILL BE POTENTIAL FOR MVFR STATUS
TO CONTINUE...MAINLY AT GOODLAND FOR MOST OF THE NIGHT. WHILE BULK
OF GUIDANCE HAS CIGS AOB 3500 FEET FOR TONIGHT...CONDITIONAL
CLIMATOLOGY WHICH IS SUPPORTED BY RAP SUPPORT MORE OF A
PERSISTENCE FORECAST THROUGH 08Z. CLOUDS TONIGHT WILL LIMIT ANY
FOG THREAT AND DO NOT ANTICIPATE ANY WIDESPREAD BELOW MVFR
CONDITIONS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JN
LONG TERM...99
AVIATION...JRM
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
608 PM CDT WED MAY 20 2015
...UPDATED AVIATION DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 155 PM CDT WED MAY 20 2015
UPPER LEVEL RIDGING WILL BUILD OVER THE PLAINS TONIGHT INTO
TOMORROW WITH THE NEXT STORM SYSTEM DIGGING INTO THE DESERT
SOUTHWEST. MID LEVELS OF THE ATMOSPHERE DRY OUT THIS EVENING INTO
THE OVERNIGHT, HOWEVER, LOW LEVEL MOISTURE STAYS IN PLACE ALLOWING
MOSTLY CLOUDY SKIES TO PERSIST. THERE MAY BE A FEW BREAKS IN THE
CLOUDS TOWARDS SUNSET INTO THE EVENING, THEN AGAIN TOMORROW
AFTERNOON. MOISTURE IN THE MID LEVELS OF THE ATMOSPHERE ALSO
INCREASE AGAIN TOMORROW AFTERNOON WHICH COULD HINDER THE SUN FROM
PENETRATING TO THE GROUND. A DOME OF HIGH PRESSURE WILL BE LOCATED
NORTH OF THE FORECAST AREA TONIGHT THEN SLIDE EAST OF THE AREA
TOMORROW. THIS WILL LEAD TO NORTHEASTERLY WINDS TONIGHT SHIFTING
TO MORE OF A SOUTHEASTERLY DIRECTION TOMORROW. AS FOR
TEMPERATURES, LOWS OVERNIGHT ARE PROGGED TO RANGE FROM AROUND 40
DEGREES ACROSS WEST CENTRAL KANSAS TO MID 40S ACROSS THE KS/OK
BORDER. HIGHS TOMORROW ARE EXPECTED TO REACH INTO THE LOWER TO MID
60S. THIS DEPENDS ON HOW MUCH CLOUD COVER THERE IS AND IF THE SUN
DOES BREAK THROUGH TEMPERATURES COULD BE HIGHER THAN FORECASTED.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 325 PM CDT WED MAY 20 2015
THE FORECAST CONTINUES TO BE A HUGE CHALLENGE GOING INTO THE
WEEKEND, ESPECIALLY REGARDING TEMPERATURES SATURDAY AND WHETHER OR
NOT WE WILL SEE SEVERE WX ANYWHERE ACROSS OUR AREA (SPOILER
ALERT: MOST LIKELY NOT).
TWO MORE COHERENT PRECIPITATION EVENTS ARE UPCOMING: THURSDAY
NIGHT/FRIDAY MORNING AND AGAIN SATURDAY. THE FIRST EVENT WILL BE
TIED TO A LEAD SHORTWAVE TROUGH EJECTING NORTHEAST AHEAD OF THE
PRIMARY UPPER LOW TAKING SHAPE JUST OFF THE COAST OF SOUTHERN
CALIFORNIA. THIS EVENT WILL EVOLVE NOT TOO DISSIMILAR TO YESTERDAY`S
PRECIP EVENT..IN THAT A SHIELD OF RAIN WILL DEVELOP ACROSS WEST
TEXAS/TX PANHANDLE AND ADJACENT NORTHEAST NEW MEXICO...EXTENDING
INTO EASTERN COLORADO ALONG A ZONE OF FAIRLY STRONG 800-700MB WARM
FRONTOGENESIS. THIS WILL CONTINUE TO MOVE NORTHEAST INTO SOUTHWEST
KANSAS DURING THE OVERNIGHT HOURS. WE WILL BE GOING WITH
CATEGORICAL POPS FOR MUCH OF THE AREA NOW FOR THE THURSDAY NITH
PERIOD (80+ PERCENT). RAINFALL TOTALS WITH THIS EVENT SHOULD BE LESS
THAN TUESDAY AS THIS LEAD WAVE AND ASSOCIATED LIFT WILL MOVE THROUGH
FAIRLY QUICKLY.
SOME VERY LIGHT RAIN OR DRIZZLE WILL LIKELY CONTINUE THROUGH THE DAY
FRIDAY WITH LOW LEVEL SOUTHEASTERLY COOL, MOIST UPSLOPE CONTINUING.
MEANWHILE, THE ECMWF CONTINUES TO SHOW ANOTHER LARGE ROUND OF
CONVECTIVE ACTIVITY FRIDAY ACROSS NORTHWEST TEXAS INTO OKLAHOMA,
WHICH WILL REINFORCE THE BOUNDARY DOWN THERE. ABOVE THE SURFACE, WE
WILL SEE A CONTINUED ADVECTION OF GULF MOISTURE INTO WESTERN KANSAS,
WHICH WILL TRANSLATE INTO A LARGE AREAL EXTENT OF STRATUS WITH THE
LOWER TROPOSPHERE REMAINING COOL. THE ECMWF AND GFS COMPLETELY
DIFFER BY FRIDAY NIGHT INTO SATURDAY. THE GFS40 BEGINS TO SHEAR OUT
THE UPPER LOW INTO A POSITIVELY TILTED TROUGH AXIS FROM ARIZONA INTO
WYOMING WITH THE ECMWF HANGING ONTO AN UPPER LOW CENTER ALONG THE
ARIZONA-UTAH BORDER. THIS IS THE BASIC REASONING BEHIND THE
DIFFERING OF SOLUTIONS AND WHY THE GFS40 IS SO AGGRESSIVE WITH THE
LOWER TROPOSPHERIC FLOW INTO WESTERN KANSAS AND NEBRASKA...WARMING
THE 850MB LEVEL UP IN THE PROCESS. THE SLOWER, DEEPER ECMWF SOLUTION
RESULTS IN 850MB REFLECTION ACROSS EAST-CENTRAL NEW MEXICO...WITH AN
EFFECTIVE BACKING OF THE LOWER TROPOSPHERIC FLOW NORTH AND EAST
ACROSS TEXAS PANHANDLE AND INTO SOUTHWEST KANSAS. THIS SCENARIO
KEEPS THE COOL, MOIST AIRMASS IN CHECK ACROSS THE CENTRAL HIGH
PLAINS, AND IS THE SCENARIO WHICH MAKES MORE SENSE GIVEN PAST
EXPERIENCE WITH THE SKILL OF THE ECMWF IN HANDLING SOUTHWEST LOWS
AT THE D+2 TO D+5 TIME FRAME. AS THE LOW APPROACHES SATURDAY, IT
WILL BEGIN TO LIFT OUT ACROSS THE ROCKIES...AND VIGOROUS
CONVECTION IS SUGGESTED BY THE ECMWF SATURDAY FROM WEST TEXAS NEAR
THE 850MB ZONE OF WARM FRONTOGENESIS INTO OKLAHOMA ALONG THE
SURFACE WARM FRONTOGENETIC ZONE. THE GFS MODEL JUST DOES NOT
APPEAR TO BE A REASONABLE SOLUTION AS ITS PERFORMANCE HAS BEEN
POOR AGAINST THE ECMWF IN THIS REGIME OVER THE PAST COUPLE OF
WEEKS.
THE END RESULT ON SATURDAY FOR SOUTHWEST KANSAS WILL LIKELY BE
COOLER TEMPERATURES, MUCH MORE CLOUD COVER, AND PERIODIC
PRECIPITATION INCLUDING DRIZZLE. TEMPERATURES WERE LOWERED SOME, BUT
WE COULD NOT LOWER DOWN TO THE COLDEST ECMWF SOLUTION DUE TO
RELUCTANCE OF NEIGHBORING OFFICES TO JUMP OFF THE SUPERBLEND
GUIDANCE MUCH (WHICH SHOWS UPPER 60S TO LOWER 70 HIGHS GIVEN SUCH
NCEP INFLUENCE). I EXPECT THE NCEP MODELS TO TREND TOWARD THE
ECMWF AS WE GET CLOSER TO SATURDAY. THE LACK OF CAPE, AS A RESULT,
WILL LEAD TO A LACK OF SEVERE WEATHER ACROSS SOUTHWEST KANSAS AS
IT APPEARS BASED ON THE ECMWF...WITH ANOTHER SEVERE
WEATHER/ONGOING FLOODING EPISODE LIKELY FROM NORTHWEST TEXAS INTO
SOUTHERN OKLAHOMA.
BEYOND SATURDAY...THE MAIN UPPER LOW WILL LIFT NORTH-NORTHEAST AS
ANOTHER PERTURBATION DIGS INTO THE BASE OF THE UPPER TROUGH ACROSS
NORTHERN MEXICO. THE MAIN 500MB TROUGH AXIS, AS SHOWN BY THE ECMWF,
WILL REMAIN WEST OF SOUTHWEST KANSAS THROUGH MONDAY...AND AS LONG AS
IT REMAINS WEST OF US, WE WILL KEEP GOOD CHANCES OF PRECIPITATION
GOING. THE AIRMASS WILL VERY SLOWLY MODIFY THROUGH MONDAY...BUT IT
WILL TAKE SOME SUSTAINED STRONG WESTERLY MOMENTUM IN THE MID
TROPOSPHERE TO ERODE THIS COOL AIRMASS. THIS MAY FINALLY OCCUR BY
MID NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 604 PM CDT WED MAY 20 2015
NORTHEAST WINDS AT 10 KNOTS OR LESS WILL GRADUALLY SHIFT TO THE
SOUTHEAST LATE TONIGHT AS AN AREA OF HIGH PRESSURE AT THE SURFACE
MOVES ACROSS KANSAS. THE SOUTHEASTERLY WINDS WILL THEN CONTINUE
DURING THE DAY ON THURSDAY AS A SURFACE PRESSURES BEGIN TO FALL
ACROSS SOUTHEAST COLORADO LATE DAY. 18Z NAM AND RAP BOTH SUGGESTS
HIGH MVFR/LOW VFR CLOUD COVER AT DDC AND GCK WILL GIVE WAY TO VFR
CEILINGS AT OR ABOVE 6000FT AGL BETWEEN 03Z AND 06Z THURSDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 43 64 48 60 / 0 10 80 90
GCK 43 63 48 61 / 0 10 80 90
EHA 45 61 48 67 / 10 10 70 70
LBL 45 65 48 64 / 10 10 80 80
HYS 42 63 47 60 / 0 10 60 70
P28 46 66 50 62 / 0 10 80 80
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...HOVORKA_42
LONG TERM...UMSCHEID
AVIATION...BURGERT
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1100 PM EDT WED MAY 20 2015
.UPDATE...
ISSUED AT 1100 PM EDT WED MAY 20 2015
LIGHT RAIN SHOWERS ARE MOVING IN FROM THE WEST...HOWEVER THE
RETURNS CONTINUE TO BE VERY LIGHT. THE LAST FEW RUNS OF THE HRRR
HAVE COME IN WITH LESS AREAL COVERAGE THROUGH THE NIGHT. WILL
MAINTAIN LOW END LIKELY POPS...BUT CUT BACK THE QPF...AS A FEW
HUNDREDTHS TO SEVERAL HUNDREDTHS OF AN INCH AT BEST LOOK MORE
REASONABLE AT THIS POINT. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 853 PM EDT WED MAY 20 2015
LIGHT PRECIPITATION IS TRYING TO MAKE IT IN FROM THE WEST...BUT
SO FAR...THE LOW LEVEL DRY AIR HAS BEEN HOLDING IT TO A FEW
SPRINKLES AT BEST. THE LATEST HRRR STILL CONTINUES TO SHOW SOME
BETTER AREAL COVERAGE EVENTUALLY SHIFTING ACROSS EASTERN KENTUCKY
THROUGH THE OVERNIGHT...AS A SHORT WAVE TROUGH DRAWS CLOSER TO
THE AREA. WILL STICK WITH THE CURRENT FORECAST AND MAINLY ADJUST
THE POP TIMING ACCORDING TO THE LATEST RADAR AND SHORT TERM MODEL
GUIDANCE TRENDS. UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 345 PM EDT WED MAY 20 2015
A GENERALLY ZONAL PATTERN WAS IN PLACE FROM THE PLAINS INTO THE
EASTERN CONUS THIS AFTERNOON. A SHORTWAVE TROUGH WAS MOVING EAST
IN THIS FLOW AND WAS OVER THE MS VALLEY REGION. FURTHER TO THE
NORTH OF THE REGION...AN UPPER LEVEL LOW WAS DROPPING SOUTH ACROSS
THE HUDSON BAY REGION. SFC HIGH PRESSURE AND SHORTWAVE RIDGING
THAT IS DEPARTING HAVE BROUGHT MOSTLY SUNNY SKIES TO THE REGION.
HOWEVER...HIGH CLOUDS HAVE BEEN INCREASING THIS AFTERNOON WITH MID
LEVEL CLOUDS AS CLOSE AS CENTRAL KY. RADAR RETURNS HAVE RAIN
SHOWERS ACROSS SOUTHERN IL AND INTO PARTS OF IN AS WELL AS WESTERN
KY AND MIDDLE TN. SOME THUNDERSTORMS ARE OCCURRING OVER SOUTHERN
MIDDLE TN. THESE SHOWERS AND STORMS ARE IN ASSOCIATION WITH THE
SHORTWAVE TROUGH MOVING FROM THE MS VALLEY AND INTO THE LOWER OH
AND TN VALLEY REGIONS. AT THE SFC...A LOW PRESSURE SYSTEM IS
NEARING THE MID MS VALLEY REGION.
THE SHORTWAVE TROUGH IS EXPECTED TO MOVE EAST ACROSS THE REGION
TONIGHT...WITH THE ATMOSPHERE SATURATING FROM THE TOP DOWN.
ANOTHER SHORTWAVE IS EXPECTED TO ROTATE AROUND THE UPPER LOW THAT
WILL MOVE FROM THE HUDSON AND JAMES BAY REGION INTO QUEBEC BY THE
END OF THE PERIOD. THIS SECOND SHORTWAVE WILL USHER IN A COLDER
AND DRIER AIR MASS INTO THE REGION. AT THE SFC...THE LOW PRESSURE
SYSTEM IS EXPECTED TO TRACK EAST JUST TO THE SOUTH OF THE REGION
TONIGHT WITH THIS SYSTEM REACHING THE EASTERN SEABOARD ON THURSDAY
EVENING. MEANWHILE...SFC HIGH PRESSURE WILL BUILD EAST INTO THE
REGION BEHIND THIS SFC LOW FOR THU NIGHT.
THE SHORTWAVE TROUGH MOVING ACROSS THE REGION TONIGHT AND THE SFC
LOW PASSING TO OUR SOUTH COMBINATION SHOULD BRING NUMEROUS SHOWERS
TO THE REGION BY LATE THIS EVENING INTO THE OVERNIGHT HOURS.
DEEPER MOISTURE AND SOMEWHAT BETTER INSTABILITY IS ANTICIPATED
NEAR THE TN BORDER CLOSER TO THE SFC LOW TRACK...AND A STRAY
THUNDERSTORM CANNOT BE RULED OUT NEAR THE TN BORDER AND THE
KY/TN/VA TRI STATE AREA THIS EVENING. THE LAST TWO GFS RUNS BRING
PRECIPITATION TO MUCH OF THE AREA TONIGHT. THE GFS HAD BEEN
CONSISTENTLY DRIER THAN MUCH OF THE GUIDANCE LEADING UP TO THIS
EVENT. WITH THE GFS NOW BRINGING SHOWERS TO THE AREA AS
WELL...POPS HAVE BEEN RAISED INTO THE LIKELY RANGE AS MEASURABLE
PRECIPITATION APPEARS PROBABLE FOR MOST LOCATIONS. LINGERING LOW
LEVEL MOISTURE AND WINDS BRIEFLY GOING UPSLOPE BEHIND THE
DEPARTING LOW WILL BRING THE THREAT FOR LINGERING SHOWERS INTO THE
DAY ON THURSDAY.
HIGH PRESSURE WILL USHER IN A COLDER AND DRIER AIR MASS LATE THU
INTO THU NIGHT...WITH WIDESPREAD LOW TO MID 40S ANTICIPATED. SOME
OF THE COOP MOS GUIDANCE SUGGESTS THAT COLDEST SPOTS IN THE NORTH
COULD REACH 39 OR 40...SO A FEW OF THE NORMALLY COLDER SPOTS MAY
NEED TO BE LOWERED A DEGREE OR TWO AS THU NIGHT APPROACHES.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 315 PM EDT WED MAY 20 2015
NORTHWESTERLY FLOW ALOFT WILL DOMINATE THE REGION AS AN UPPER LEVEL
RIDGE BUILDS INTO EASTERN KENTUCKY AT THE START OF THE PERIOD. BY
THE SECOND HALF OF THE WEEKEND...THIS RIDGE WILL STRENGTHEN AND PUSH
EWD TOWARD THE EAST COAST ALLOWING FOR A TRANSITION TO SOUTHERLY
FLOW AT MID AND UPPER LEVELS. AN ACTIVE WEATHER PATTERN IS THEN IN
STORE FOR EASTERN KENTUCKY AS THE SOUTHERLY FLOW BRINGS AN INCREASE
IN MOISTURE AND A SERIES OF IMPULSES THROUGH THE END OF THE PERIOD.
AT THE SURFACE...THE FIRST PART OF MEMORIAL DAY WEEKEND WILL FEATURE
DRY AND BEAUTIFUL SPRING WEATHER WITH TEMPERATURES TOPPING OUT IN
THE LOW TO MID 70S FRIDAY AND SATURDAY. THE SURFACE RIDGE THEN
SHIFTS EAST OF THE REGION SUNDAY AS THE UPPER LEVEL RIDGE
STRENGTHENS OVER THE SOUTHEASTERN US...ALLOWING FOR MOISTURE AND
CLOUD COVER TO INCREASE. THERE WILL BE CHANCES FOR SHOWERS AND
DIURNALLY DRIVEN CONVECTION SUNDAY AFTERNOON THROUGH WEDNESDAY WITH
INSTABILITY INCREASING EACH DAY. TEMPERATURES WILL BE DEPENDENT ON
CONVECTIVE TIMING/COVERAGE...BUT A GENERAL WARMING TREND FROM THE
70S ON FRIDAY INTO THE MID 80S BY WEDNESDAY IS ANTICIPATED.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 853 PM EDT WED MAY 20 2015
CLOUDS WILL THICKEN AND LOWER WITH LIGHT RAIN SHOWERS EVENTUALLY
BREAKING OUT ACROSS THE AREA AS AN UPPER LEVEL DISTURBANCE PASSES
THROUGH THE OHIO AND TENNESSEE VALLEYS TONIGHT. MVFR CONDITIONS
WILL WORK IN CLOSER TO MIDNIGHT FROM THE WEST AND THEN SPREAD
EASTWARD OVERNIGHT. EVENTUALLY...CEILINGS WILL LOWER TO IFR
STATUS CLOSER TOWARDS DAWN. CEILINGS WILL GRADUALLY IMPROVE TO
MVFR BY EARLY THURSDAY AFTERNOON. WINDS WILL REMAIN AT AROUND 5
KTS GENERALLY OUT OF THE NORTHEAST THROUGH THE NIGHT...BEFORE
BECOMING NORTHWEST AT 5 TO 10 KTS ON THURSDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...JP
LONG TERM...JVM
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
853 PM EDT WED MAY 20 2015
.UPDATE...
ISSUED AT 853 PM EDT WED MAY 20 2015
LIGHT PRECIPITATION IS TRYING TO MAKE IT IN FROM THE WEST...BUT
SO FAR...THE LOW LEVEL DRY AIR HAS BEEN HOLDING IT TO A FEW
SPRINKLES AT BEST. THE LATEST HRRR STILL CONTINUES TO SHOW SOME
BETTER AREAL COVERAGE EVENTUALLY SHIFTING ACROSS EASTERN KENTUCKY
THROUGH THE OVERNIGHT...AS A SHORT WAVE TROUGH DRAWS CLOSER TO
THE AREA. WILL STICK WITH THE CURRENT FORECAST AND MAINLY ADJUST
THE POP TIMING ACCORDING TO THE LATEST RADAR AND SHORT TERM MODEL
GUIDANCE TRENDS. UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 345 PM EDT WED MAY 20 2015
A GENERALLY ZONAL PATTERN WAS IN PLACE FROM THE PLAINS INTO THE
EASTERN CONUS THIS AFTERNOON. A SHORTWAVE TROUGH WAS MOVING EAST
IN THIS FLOW AND WAS OVER THE MS VALLEY REGION. FURTHER TO THE
NORTH OF THE REGION...AN UPPER LEVEL LOW WAS DROPPING SOUTH ACROSS
THE HUDSON BAY REGION. SFC HIGH PRESSURE AND SHORTWAVE RIDGING
THAT IS DEPARTING HAVE BROUGHT MOSTLY SUNNY SKIES TO THE REGION.
HOWEVER...HIGH CLOUDS HAVE BEEN INCREASING THIS AFTERNOON WITH MID
LEVEL CLOUDS AS CLOSE AS CENTRAL KY. RADAR RETURNS HAVE RAIN
SHOWERS ACROSS SOUTHERN IL AND INTO PARTS OF IN AS WELL AS WESTERN
KY AND MIDDLE TN. SOME THUNDERSTORMS ARE OCCURRING OVER SOUTHERN
MIDDLE TN. THESE SHOWERS AND STORMS ARE IN ASSOCIATION WITH THE
SHORTWAVE TROUGH MOVING FROM THE MS VALLEY AND INTO THE LOWER OH
AND TN VALLEY REGIONS. AT THE SFC...A LOW PRESSURE SYSTEM IS
NEARING THE MID MS VALLEY REGION.
THE SHORTWAVE TROUGH IS EXPECTED TO MOVE EAST ACROSS THE REGION
TONIGHT...WITH THE ATMOSPHERE SATURATING FROM THE TOP DOWN.
ANOTHER SHORTWAVE IS EXPECTED TO ROTATE AROUND THE UPPER LOW THAT
WILL MOVE FROM THE HUDSON AND JAMES BAY REGION INTO QUEBEC BY THE
END OF THE PERIOD. THIS SECOND SHORTWAVE WILL USHER IN A COLDER
AND DRIER AIR MASS INTO THE REGION. AT THE SFC...THE LOW PRESSURE
SYSTEM IS EXPECTED TO TRACK EAST JUST TO THE SOUTH OF THE REGION
TONIGHT WITH THIS SYSTEM REACHING THE EASTERN SEABOARD ON THURSDAY
EVENING. MEANWHILE...SFC HIGH PRESSURE WILL BUILD EAST INTO THE
REGION BEHIND THIS SFC LOW FOR THU NIGHT.
THE SHORTWAVE TROUGH MOVING ACROSS THE REGION TONIGHT AND THE SFC
LOW PASSING TO OUR SOUTH COMBINATION SHOULD BRING NUMEROUS SHOWERS
TO THE REGION BY LATE THIS EVENING INTO THE OVERNIGHT HOURS.
DEEPER MOISTURE AND SOMEWHAT BETTER INSTABILITY IS ANTICIPATED
NEAR THE TN BORDER CLOSER TO THE SFC LOW TRACK...AND A STRAY
THUNDERSTORM CANNOT BE RULED OUT NEAR THE TN BORDER AND THE
KY/TN/VA TRI STATE AREA THIS EVENING. THE LAST TWO GFS RUNS BRING
PRECIPITATION TO MUCH OF THE AREA TONIGHT. THE GFS HAD BEEN
CONSISTENTLY DRIER THAN MUCH OF THE GUIDANCE LEADING UP TO THIS
EVENT. WITH THE GFS NOW BRINGING SHOWERS TO THE AREA AS
WELL...POPS HAVE BEEN RAISED INTO THE LIKELY RANGE AS MEASURABLE
PRECIPITATION APPEARS PROBABLE FOR MOST LOCATIONS. LINGERING LOW
LEVEL MOISTURE AND WINDS BRIEFLY GOING UPSLOPE BEHIND THE
DEPARTING LOW WILL BRING THE THREAT FOR LINGERING SHOWERS INTO THE
DAY ON THURSDAY.
HIGH PRESSURE WILL USHER IN A COLDER AND DRIER AIR MASS LATE THU
INTO THU NIGHT...WITH WIDESPREAD LOW TO MID 40S ANTICIPATED. SOME
OF THE COOP MOS GUIDANCE SUGGESTS THAT COLDEST SPOTS IN THE NORTH
COULD REACH 39 OR 40...SO A FEW OF THE NORMALLY COLDER SPOTS MAY
NEED TO BE LOWERED A DEGREE OR TWO AS THU NIGHT APPROACHES.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 315 PM EDT WED MAY 20 2015
NORTHWESTERLY FLOW ALOFT WILL DOMINATE THE REGION AS AN UPPER LEVEL
RIDGE BUILDS INTO EASTERN KENTUCKY AT THE START OF THE PERIOD. BY
THE SECOND HALF OF THE WEEKEND...THIS RIDGE WILL STRENGTHEN AND PUSH
EWD TOWARD THE EAST COAST ALLOWING FOR A TRANSITION TO SOUTHERLY
FLOW AT MID AND UPPER LEVELS. AN ACTIVE WEATHER PATTERN IS THEN IN
STORE FOR EASTERN KENTUCKY AS THE SOUTHERLY FLOW BRINGS AN INCREASE
IN MOISTURE AND A SERIES OF IMPULSES THROUGH THE END OF THE PERIOD.
AT THE SURFACE...THE FIRST PART OF MEMORIAL DAY WEEKEND WILL FEATURE
DRY AND BEAUTIFUL SPRING WEATHER WITH TEMPERATURES TOPPING OUT IN
THE LOW TO MID 70S FRIDAY AND SATURDAY. THE SURFACE RIDGE THEN
SHIFTS EAST OF THE REGION SUNDAY AS THE UPPER LEVEL RIDGE
STRENGTHENS OVER THE SOUTHEASTERN US...ALLOWING FOR MOISTURE AND
CLOUD COVER TO INCREASE. THERE WILL BE CHANCES FOR SHOWERS AND
DIURNALLY DRIVEN CONVECTION SUNDAY AFTERNOON THROUGH WEDNESDAY WITH
INSTABILITY INCREASING EACH DAY. TEMPERATURES WILL BE DEPENDENT ON
CONVECTIVE TIMING/COVERAGE...BUT A GENERAL WARMING TREND FROM THE
70S ON FRIDAY INTO THE MID 80S BY WEDNESDAY IS ANTICIPATED.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 853 PM EDT WED MAY 20 2015
CLOUDS WILL THICKEN AND LOWER WITH LIGHT RAIN SHOWERS EVENTUALLY
BREAKING OUT ACROSS THE AREA AS AN UPPER LEVEL DISTURBANCE PASSES
THROUGH THE OHIO AND TENNESSEE VALLEYS TONIGHT. MVFR CONDITIONS
WILL WORK IN CLOSER TO MIDNIGHT FROM THE WEST AND THEN SPREAD
EASTWARD OVERNIGHT. EVENTUALLY...CEILINGS WILL LOWER TO IFR
STATUS CLOSER TOWARDS DAWN. CEILINGS WILL GRADUALLY IMPROVE TO
MVFR BY EARLY THURSDAY AFTERNOON. WINDS WILL REMAIN AT AROUND 5
KTS GENERALLY OUT OF THE NORTHEAST THROUGH THE NIGHT...BEFORE
BECOMING NORTHWEST AT 5 TO 10 KTS ON THURSDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...JP
LONG TERM...JVM
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
345 PM CDT TUE MAY 19 2015
.DISCUSSION...
OUR TEMPERATURES ARE IN THE LOW 80S NORTH TO MID 80S ELSEWHERE.
THE NORTHEAST WINDS ARE RUNNING OUT OF GAS. AS EXPECTED AFTERNOON
THUNDERSTORM INITIATION HAS OCCURRED OVER OUR TEXAS COUNTIES
LIFTING NORTHEAST WARD WITH MEAGER COVERAGE SO FAR. THE WINDS
THERE ARE MOIST FROM THE SOUTHEAST. FOR NOW...THE MORE STABLE AIR
REMAINS OVER OUR EAST AND MAYBE FOR A WHILE YET.
FARTHER WEST...THUNDERSTORMS ARE STRONGER AND TO SOME EXTENT A
BIT MORE NUMEROUS. THE WATER VAPOR SHOWS THE REASON IS A GOOD PUSH
OUT OF THE ROCKIES OUT INTO THE PLAINS WITH A LARGE UPPER LOW. THE
TAIL END OF THIS FEATURE WILL CONTINUE IT/S EVOLUTION BEYOND
SUNDOWN WITH THE EXPECTATION OF THE UPPER DIVERGENCE ALOFT AHEAD
OF THE LOW WORKING EAST OUT INTO THE MID SOUTH OVERNIGHT.
SO AFTER A BRIEF BREAK FROM THE ACTION WE HAVE THE WEAK FRONTAL
BOUNDARY NOW ALONG THE AR/LA STATE LINE OR SO WITH A CONTINUED
LIFT BACK TO THE NORTH OVERNIGHT. THE HRRR SHOWS A GOOD PUSH OF
QPF INTO OUR NW CORNER AFTER MIDNIGHT WITH MUCH OF THE DIURNAL
COVERAGE GONE HOURS EARLIER IN THE MID EVENING. THE NAM IS
SIMILAR...BUT MUCH SLOWER. THE RAIN THAT ACTUALLY FALLS IN THIS
AREA IS CRUCIAL TO RIVER FORECAST WHICH IS QPF DRIVEN. SO CLOSE
ATTENTION TO CONDITIONS IS MORE THAN WARRANTED WITH ALREADY PRETTY
HIGH WATER AND SOIL SATURATION AS YET ANOTHER FRONTAL BOUNDARY
WILL SETTLE INTO THE I-20 CORRIDOR LATE TOMORROW AND INTO EARLY
THURSDAY.
THE WEATHER PATTERN WILL NOT CHANGE GREATLY AS WE SEE ANOTHER
DEEP TROUGH MOVING INTO THE ROCKIES OVER THE WEEKEND AND OUT INTO
THE PLAINS EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 69 86 70 79 / 20 30 50 40
MLU 69 88 69 79 / 20 30 50 40
DEQ 68 82 62 74 / 60 50 50 30
TXK 68 83 67 75 / 50 40 50 40
ELD 67 83 65 75 / 20 30 50 40
TYR 70 84 66 78 / 30 30 50 40
GGG 69 85 68 79 / 30 30 50 40
LFK 71 86 71 83 / 20 20 30 40
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
24
AREA FORECAST DISCUSSION
NWS GRAY ME
1258 PM EDT TUE MAY 19 2015
.SYNOPSIS...
SHOWERS ASSOCIATED WITH A WARM FRONT WILL SPREAD ACROSS THE REGION
THIS MORNING. SHOWERS AND THUNDERSTORMS WILL DEVELOP THIS
AFTERNOON AND EVENING AHEAD OF A COLD FRONT. A NORTHWEST FLOW
WILL DEVELOP BEHIND THE FRONT TONIGHT AND PROVIDE COOL BUT MOSTLY
QUIET WEATHER INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1 PM UPDATE...FORECAST REMAINS ON TRACK. SHOWERS WITH EMBEDDED
THUNDER DEVELOPING ACROSS UPSTATE NY IN ADVANCE OF COLD FRONT.
THESE WILL MOVE EASTWARD AND INTO THE CT VALLEY AROUND OR AFTER 4
PM. HEATING IS BEGINNING TO OCCUR THERE AND SHOULD CONTRIBUTE TO
ENOUGH CAPE TO SUSTAIN A FEW STRONG TO LOCALLY SEVERE STORMS LATE
THIS AFTERNOON.
950 AM UPDATE...HAVE UPDATED THE FORECAST TO FRESHEN UP THE TIMING
OF POPS TODAY AS WELL AS TEMPERATURES. OVERALL...FORECAST REMAINS
ON TRACK. WIDESPREAD RAIN THIS MORNING WILL PUSH OFF THE COAST IN
A FEW HOURS AND SHOULD ALLOW FOR AT LEAST PARTIAL SUNSHINE THIS
AFTERNOON...ESPECIALLY ACROSS THE INTERIOR. THIS WILL LEAD TO
INCREASING INSTABILITY. AS A SHORT WAVE TROUGH APPROACHES THIS
AFTERNOON...THUNDERSTORMS SHOULD DEVELOP IN UPSTATE NY AND VT AND
REACH THE CT VALLEY BY 4 PM. THE STORMS SHOULD THEN PROGRESS
EASTWARD AND EXIT THE COAST BETWEEN 8 AND 9 PM. A FEW SEVERE
STORMS WILL BE POSSIBLE...ESPECIALLY ACROSS NH.
PREVIOUSLY...
530AM UPDATE...
HAVE UPDATED HOURLY PRECIPITATION CHANCES BASED ON RECENT RADAR
TRENDS. MUCH OF THE AREA IS SEEING SHOWERS NOW EXCEPT THE
IMMEDIATE COAST. THIS WILL CHANGE SOON. BACK EDGE OF PRECIPITATION
MOVING INTO VERMONT NOW AND WILL REACH WESTERN NEW HAMPSHIRE
WITHIN THE NEXT 2 TO 3 HOURS.
ORIGINAL DISCUSSION...
AREA OF SHOWERS AND A FEW EMBEDDED THUNDERSTORMS IS MOVING THROUGH
THE HUDSON VALLEY EARLY THIS MORNING AND SHOULD ARRIVE IN NEW
HAMPSHIRE IN THE NEXT TWO HOURS BEFORE SPREADING EASTWARD ACROSS
THE REST OF NEW HAMPSHIRE AND WESTERN MAINE THIS MORNING. THIS
AREA OF PRECIPITATION IS ASSOCIATED WITH A WARM FRONT-LIKE
FEATURE IN THAT BEHIND IT DEWPOINTS ARE SURGING INTO THE MID 60S
WHILE THE COOL MARITIME AIR MASS AHEAD OF IT IS COOLER AND WITH
LOWER DEWPOINTS. BUT YOU WILL BE HARD PRESSED TO FIND A
NOTICEABLE WIND SHIFT OR PRESSURE TROUGH WITH IT. SUCH IS LIFE IN
NORTHERN NEW ENGLAND.
AREA OF RAIN WILL MOVE INTO THE MIDCOAST REGION OF MAINE LATE IN
THE MORNING AND PERSIST INTO THE AFTERNOON. WHILE NEW HAMPSHIRE
WILL SEE THE RAIN ENDING EARLIER IN THE MORNING. BREAKS IN THE
CLOUDS SHOULD ALLOW FOR PRETTY GOOD WARMING INTO THE MID TO UPPER
70S OVER WESTERN NEW HAMPSHIRE. THE COMBINATION OF THIS WARMING...
THE INCREASING LOW LEVEL MOISTURE... AND COOLING TEMPERATURES
ALOFT ASSOCIATED WITH A SHORTWAVE TROUGH WILL PROVIDE SUBSTANTIAL
INSTABILITY THIS AFTERNOON... PERHAPS THE BEST SEEN YET THIS
SEASON. CAPE APPROACHES OR EXCEEDS 1000 BY LATE THIS AFTERNOON AND
EARLY EVENING OVER VERMONT AND NEW HAMPSHIRE. JUST AS INSTABILITY
IS INCREASING... A COLD FRONT WILL BEGIN MOVING ACROSS NORTHERN
NEW ENGLAND FROM WEST TO EAST. THIS WILL PROVIDE LOW LEVEL
CONVERGENCE TO ADD LIFT TO THE EQUATION... AIDING IN THE
DEVELOPMENT OF THUNDERSTORMS. BEST INSTABILITY AND LIFT DOES NOT
ARRIVE UNTIL LATE IN THE DAY... SO THUNDERSTORM POTENTIAL SEEMS TO
BE MORE IN THE 4PM-8PM TIME PERIOD... WITH REMNANT STORMS LIKELY
MAINTAINING THEMSELVES THROUGH ELEVATED INSTABILITY THROUGH
MIDNIGHT TONIGHT.
MESOSCALE MODELS INCLUDING THE NAM AND HRRR INDICATING POTENTIALLY
TWO SEPARATE AREAS OF MORE WIDESPREAD THUNDERSTORM ACTIVITY LATE
THIS AFTERNOON. THE FIRST IS OVER THE NORTHERN ADIRONDACKS AND THE
SECOND OVER THE CATSKILLS... BOTH AREAS FIRING AS THE FRONT MOVES
THROUGH TO PROVIDE LIFT AND MAY BE ENHANCED DUE TO TERRAIN-BASED
INSTABILITY. IF THIS SCENARIO UNFOLDS... THEN THE NORTHERN AREA OF
THUNDERSTORMS WOULD MOVE EAST ACROSS VERMONT AND THE NORTHERN HALF
OF NEW HAMPSHIRE AND INTO NORTHWEST MAINE IN THE EVENING. THE
SOUTHERN CLUSTER WOULD MOVE EAST MAINLY INTO MASSACHUSETTS. HAVE
ORIENTED AFTERNOON/EVENING THUNDERSTORM CHANCES AS BEING GREATEST
IN THE NORTH WHERE THE MORE NORTHERN CLUSTER OF STORMS WOULD MOVE
ACROSS BUT HAVE MAINTAINED AT LEAST A CHANCE OF THUNDERSTORMS OVER
ALL OF NEW HAMPSHIRE AND EXTENDING INTO FAR WESTERN/NORTHERN
MAINE IN THE EVENING.
ONE FINAL INGREDIENT TO ADD TO THE MIX TODAY IS INCREASING WIND
SHEAR. BY EVENING... AROUND THE TIME THE FRONT WILL BE MOVING INTO
NEW HAMPSHIRE... WINDS ALOFT APPROACH 50 KT AT 700 MB WHILE
SURFACE WINDS ARE BROADLY LIGHT OUT OF THE SOUTH. THIS WILL
PROVIDE ENOUGH SPEED SHEAR TO PROVIDE STORM ORGANIZATION AND
SUPERCELL TYPE STRUCTURES. THIS MAKES SEVERE THUNDERSTORMS MORE
LIKELY... WITH DAMAGING WINDS AND HAIL BEING THE PRIMARY THREATS.
HOWEVER... GIVEN LOW LEVEL WINDS OUT OF THE SOUTH... CANNOT RULE
OUT THE POSSIBILITY OF AN ISOLATED TORNADO PARTICULARLY IN AREAS
WHERE LOW LEVEL WINDS ARE CHANNELED BY TERRAIN AND PRODUCE GREATER
LOCALIZED DIRECTIONAL SHEAR. HAVE MENTIONED THE THREAT OF DAMAGING
WINDS AND LARGE HAIL IN THE PUBLIC FORECAST FOR LATE THIS
AFTERNOON. HAVE ALSO ORIENTED HOURLY PRECIPITATION CHANCES TO
BETTER REFLECT THE IDEA THAT EARLY MORNING SHOWERS WILL MOVE EAST
BEFORE THE CHANCE OF THUNDERSTORMS ARRIVES LATE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
COLD FRONT WILL PUSH EAST ACROSS THE REGION TONIGHT WITH
THUNDERSTORM ACTIVITY LIKELY LINGERING INTO THE EVENING...
POSSIBLY TO AROUND MIDNIGHT IN NORTHERN MAINE. COOLER AND DRIER
AIR WILL BE MOVING IN BEHIND THE COLD FRONT. COULD SEE SOME FOG
NEAR THE COAST BEFORE THE FRONT MOVES THROUGH AND BEGINS TO
MIX/DRY THINGS OUT. TEMPERATURES FALL INTO THE UPPER 40S AND LOW
50S.
WILL BE A COOLER DAY ON WEDNESDAY FOR MOST OF THE REGION. BUT ON
THE COAST IT MAY ACTUALLY BE A FEW DEGREES WARMER... A TYPICAL
RESULT OF A PASSING COLD FRONT AND A SHIFT TO OFFSHORE WINDS. HIGH
TEMPERATURES RANGE FROM THE MID 50S IN THE NORTH TO THE MID 60S
NEAR THE COAST. DEWPOINTS WILL BE FALLING INTO THE 30S WHICH WILL
MAKE IT DIFFICULT FOR ANY SHOWERS TO DEVELOP IN SPITE OF SOME LIFT
MOVING THROUGH WITH THE PASSING OF THE UPPER LEVEL TROUGH.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
A LARGE UPPER LEVEL TROUGH WILL DOMINATE THE FLOW ACROSS NEW
ENGLAND THROUGH THE WEEKEND. SEVERAL DISTURBANCES WILL ROTATE
AROUND THE TROUGH, HOWEVER, COOL DRY WEATHER WILL RULE FOR MUCH OF
THE PERIOD. A MOISTURE-STARVED FRONT DROPPING SOUTHWARD FROM
CANADA COULD BRING A FEW SHOWERS TO THE REGION FRIDAY. BEHIND THE
FRONT...TEMPERATURES WILL BE MAINLY IN THE 60S SATURDAY BUT SHOULD
START TO WARM INTO THE 70S MOST AREAS FOR SUNDAY AND MONDAY AS THE
TROUGH AXIS SLIDES EAST OF THE REGION. MODELS NOW DELAY NEXT
SIGNIFICANT PRECIPITATION UNTIL TUESDAY, ALLOWING FOR A VERY
PLEASANT HOLIDAY WEEKEND.
NOTE: THE FREEZE/FROST PROGRAM STARTS IN NORTHERN ZONES
THURSDAY MAY 21. LOW TEMPERATURES THURSDAY AND SATURDAY MORNINGS
WILL DROP NEAR OR BELOW FREEZING ACROSS NORTHERN ZONES AND MAY
REQUIRE FREEZE WARNINGS AND/OR FROST ADVISORIES.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
SHORT TERM...EARLY MORNING IFR/LIFR CONDITIONS WILL BEGIN
IMPROVING THIS MORNING EVEN AS AN AREA OF RAIN MOVES ACROSS THE
AREA. COULD SEE MVFR CEILINGS LINGER THROUGH MUCH OF THE DAY BUT
THERE IS A BETTER CHANCE THAT CONDITIONS WILL BREAK OUT TO VFR FOR
AT LEAST A FEW HOURS. THERE IS A CHANCE OF THUNDERSTORMS ACROSS
MUCH OF NEW HAMPSHIRE LATE THIS AFTERNOON INTO EARLY THIS EVENING.
LOW CLOUDS MAY MAKE A RETURN VISIT TO COASTAL MAINE EARLY THIS
EVENING BUT THE PASSING OF A COLD FRONT DURING THE NIGHT WILL
LIKELY IMPROVE CONDITIONS TO VFR EVENTUALLY.
LONG TERM...MAINLY VFR CONDITIONS EXPECTED.
&&
.MARINE...
SHORT TERM...SOUTHERLY FLOW INCREASES TODAY THEN SHIFTS TO THE
WEST TONIGHT BEHIND A COLD FRONT. WEST WINDS COULD GUST TO AROUND
20 KT ON WEDNESDAY.
LONG TERM...WITH MAINLY OFFSHORE FLOW...WINDS AND SEAS EXPECTED
TO REMAIN BELOW SCA CRITERIA. STRONGEST WINDS AND HIGHEST SEAS
SHOULD BE WELL OFFSHORE.
&&
.FIRE WEATHER...
MOIST AIR AND WIDESPREAD WETTING RAIN TODAY WILL KEEP FIRE DANGER
CONDITIONS LOW. DRY AIR MOVES IN BEHIND A COLD FRONT TONIGHT...
LEADING TO MUCH DRIER CONDITIONS WEDNESDAY INTO THE WEEKEND.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...EKSTER
AREA FORECAST DISCUSSION
NWS GRAY ME
954 AM EDT TUE MAY 19 2015
.SYNOPSIS...
SHOWERS ASSOCIATED WITH A WARM FRONT WILL SPREAD ACROSS THE REGION
THIS MORNING. SHOWERS AND THUNDERSTORMS WILL DEVELOP THIS
AFTERNOON AND EVENING AHEAD OF A COLD FRONT. A NORTHWEST FLOW
WILL DEVELOP BEHIND THE FRONT TONIGHT AND PROVIDE COOL BUT MOSTLY
QUIET WEATHER INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
950 AM UPDATE...HAVE UPDATED THE FORECAST TO FRESHEN UP THE TIMING
OF POPS TODAY AS WELL AS TEMPERATURES. OVERALL...FORECAST REMAINS
ON TRACK. WIDESPREAD RAIN THIS MORNING WILL PUSH OFF THE COAST IN
A FEW HOURS AND SHOULD ALLOW FOR AT LEAST PARTIAL SUNSHINE THIS
AFTERNOON...ESPECIALLY ACROSS THE INTERIOR. THIS WILL LEAD TO
INCREASING INSTABILITY. AS A SHORT WAVE TROUGH APPROACHES THIS
AFTERNOON...THUNDERSTORMS SHOULD DEVELOP IN UPSTATE NY AND VT AND
REACH THE CT VALLEY BY 4 PM. THE STORMS SHOULD THEN PROGRESS
EASTWARD AND EXIT THE COAST BETWEEN 8 AND 9 PM. A FEW SEVERE
STORMS WILL BE POSSIBLE...ESPECIALLY ACROSS NH.
PREVIOUSLY...
530AM UPDATE...
HAVE UPDATED HOURLY PRECIPITATION CHANCES BASED ON RECENT RADAR
TRENDS. MUCH OF THE AREA IS SEEING SHOWERS NOW EXCEPT THE
IMMEDIATE COAST. THIS WILL CHANGE SOON. BACK EDGE OF PRECIPITATION
MOVING INTO VERMONT NOW AND WILL REACH WESTERN NEW HAMPSHIRE
WITHIN THE NEXT 2 TO 3 HOURS.
ORIGINAL DISCUSSION...
AREA OF SHOWERS AND A FEW EMBEDDED THUNDERSTORMS IS MOVING THROUGH
THE HUDSON VALLEY EARLY THIS MORNING AND SHOULD ARRIVE IN NEW
HAMPSHIRE IN THE NEXT TWO HOURS BEFORE SPREADING EASTWARD ACROSS
THE REST OF NEW HAMPSHIRE AND WESTERN MAINE THIS MORNING. THIS
AREA OF PRECIPITATION IS ASSOCIATED WITH A WARM FRONT-LIKE
FEATURE IN THAT BEHIND IT DEWPOINTS ARE SURGING INTO THE MID 60S
WHILE THE COOL MARITIME AIR MASS AHEAD OF IT IS COOLER AND WITH
LOWER DEWPOINTS. BUT YOU WILL BE HARD PRESSED TO FIND A
NOTICEABLE WIND SHIFT OR PRESSURE TROUGH WITH IT. SUCH IS LIFE IN
NORTHERN NEW ENGLAND.
AREA OF RAIN WILL MOVE INTO THE MIDCOAST REGION OF MAINE LATE IN
THE MORNING AND PERSIST INTO THE AFTERNOON. WHILE NEW HAMPSHIRE
WILL SEE THE RAIN ENDING EARLIER IN THE MORNING. BREAKS IN THE
CLOUDS SHOULD ALLOW FOR PRETTY GOOD WARMING INTO THE MID TO UPPER
70S OVER WESTERN NEW HAMPSHIRE. THE COMBINATION OF THIS WARMING...
THE INCREASING LOW LEVEL MOISTURE... AND COOLING TEMPERATURES
ALOFT ASSOCIATED WITH A SHORTWAVE TROUGH WILL PROVIDE SUBSTANTIAL
INSTABILITY THIS AFTERNOON... PERHAPS THE BEST SEEN YET THIS
SEASON. CAPE APPROACHES OR EXCEEDS 1000 BY LATE THIS AFTERNOON AND
EARLY EVENING OVER VERMONT AND NEW HAMPSHIRE. JUST AS INSTABILITY
IS INCREASING... A COLD FRONT WILL BEGIN MOVING ACROSS NORTHERN
NEW ENGLAND FROM WEST TO EAST. THIS WILL PROVIDE LOW LEVEL
CONVERGENCE TO ADD LIFT TO THE EQUATION... AIDING IN THE
DEVELOPMENT OF THUNDERSTORMS. BEST INSTABILITY AND LIFT DOES NOT
ARRIVE UNTIL LATE IN THE DAY... SO THUNDERSTORM POTENTIAL SEEMS TO
BE MORE IN THE 4PM-8PM TIME PERIOD... WITH REMNANT STORMS LIKELY
MAINTAINING THEMSELVES THROUGH ELEVATED INSTABILITY THROUGH
MIDNIGHT TONIGHT.
MESOSCALE MODELS INCLUDING THE NAM AND HRRR INDICATING POTENTIALLY
TWO SEPARATE AREAS OF MORE WIDESPREAD THUNDERSTORM ACTIVITY LATE
THIS AFTERNOON. THE FIRST IS OVER THE NORTHERN ADIRONDACKS AND THE
SECOND OVER THE CATSKILLS... BOTH AREAS FIRING AS THE FRONT MOVES
THROUGH TO PROVIDE LIFT AND MAY BE ENHANCED DUE TO TERRAIN-BASED
INSTABILITY. IF THIS SCENARIO UNFOLDS... THEN THE NORTHERN AREA OF
THUNDERSTORMS WOULD MOVE EAST ACROSS VERMONT AND THE NORTHERN HALF
OF NEW HAMPSHIRE AND INTO NORTHWEST MAINE IN THE EVENING. THE
SOUTHERN CLUSTER WOULD MOVE EAST MAINLY INTO MASSACHUSETTS. HAVE
ORIENTED AFTERNOON/EVENING THUNDERSTORM CHANCES AS BEING GREATEST
IN THE NORTH WHERE THE MORE NORTHERN CLUSTER OF STORMS WOULD MOVE
ACROSS BUT HAVE MAINTAINED AT LEAST A CHANCE OF THUNDERSTORMS OVER
ALL OF NEW HAMPSHIRE AND EXTENDING INTO FAR WESTERN/NORTHERN
MAINE IN THE EVENING.
ONE FINAL INGREDIENT TO ADD TO THE MIX TODAY IS INCREASING WIND
SHEAR. BY EVENING... AROUND THE TIME THE FRONT WILL BE MOVING INTO
NEW HAMPSHIRE... WINDS ALOFT APPROACH 50 KT AT 700 MB WHILE
SURFACE WINDS ARE BROADLY LIGHT OUT OF THE SOUTH. THIS WILL
PROVIDE ENOUGH SPEED SHEAR TO PROVIDE STORM ORGANIZATION AND
SUPERCELL TYPE STRUCTURES. THIS MAKES SEVERE THUNDERSTORMS MORE
LIKELY... WITH DAMAGING WINDS AND HAIL BEING THE PRIMARY THREATS.
HOWEVER... GIVEN LOW LEVEL WINDS OUT OF THE SOUTH... CANNOT RULE
OUT THE POSSIBILITY OF AN ISOLATED TORNADO PARTICULARLY IN AREAS
WHERE LOW LEVEL WINDS ARE CHANNELED BY TERRAIN AND PRODUCE GREATER
LOCALIZED DIRECTIONAL SHEAR. HAVE MENTIONED THE THREAT OF DAMAGING
WINDS AND LARGE HAIL IN THE PUBLIC FORECAST FOR LATE THIS
AFTERNOON. HAVE ALSO ORIENTED HOURLY PRECIPITATION CHANCES TO
BETTER REFLECT THE IDEA THAT EARLY MORNING SHOWERS WILL MOVE EAST
BEFORE THE CHANCE OF THUNDERSTORMS ARRIVES LATE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
COLD FRONT WILL PUSH EAST ACROSS THE REGION TONIGHT WITH
THUNDERSTORM ACTIVITY LIKELY LINGERING INTO THE EVENING...
POSSIBLY TO AROUND MIDNIGHT IN NORTHERN MAINE. COOLER AND DRIER
AIR WILL BE MOVING IN BEHIND THE COLD FRONT. COULD SEE SOME FOG
NEAR THE COAST BEFORE THE FRONT MOVES THROUGH AND BEGINS TO
MIX/DRY THINGS OUT. TEMPERATURES FALL INTO THE UPPER 40S AND LOW
50S.
WILL BE A COOLER DAY ON WEDNESDAY FOR MOST OF THE REGION. BUT ON
THE COAST IT MAY ACTUALLY BE A FEW DEGREES WARMER... A TYPICAL
RESULT OF A PASSING COLD FRONT AND A SHIFT TO OFFSHORE WINDS. HIGH
TEMPERATURES RANGE FROM THE MID 50S IN THE NORTH TO THE MID 60S
NEAR THE COAST. DEWPOINTS WILL BE FALLING INTO THE 30S WHICH WILL
MAKE IT DIFFICULT FOR ANY SHOWERS TO DEVELOP IN SPITE OF SOME LIFT
MOVING THROUGH WITH THE PASSING OF THE UPPER LEVEL TROUGH.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
A LARGE UPPER LEVEL TROUGH WILL DOMINATE THE FLOW ACROSS NEW
ENGLAND THROUGH THE WEEKEND. SEVERAL DISTURBANCES WILL ROTATE
AROUND THE TROUGH, HOWEVER, COOL DRY WEATHER WILL RULE FOR MUCH OF
THE PERIOD. A MOISTURE-STARVED FRONT DROPPING SOUTHWARD FROM
CANADA COULD BRING A FEW SHOWERS TO THE REGION FRIDAY. BEHIND THE
FRONT...TEMPERATURES WILL BE MAINLY IN THE 60S SATURDAY BUT SHOULD
START TO WARM INTO THE 70S MOST AREAS FOR SUNDAY AND MONDAY AS THE
TROUGH AXIS SLIDES EAST OF THE REGION. MODELS NOW DELAY NEXT
SIGNIFICANT PRECIPITATION UNTIL TUESDAY, ALLOWING FOR A VERY
PLEASANT HOLIDAY WEEKEND.
NOTE: THE FREEZE/FROST PROGRAM STARTS IN NORTHERN ZONES
THURSDAY MAY 21. LOW TEMPERATURES THURSDAY AND SATURDAY MORNINGS
WILL DROP NEAR OR BELOW FREEZING ACROSS NORTHERN ZONES AND MAY
REQUIRE FREEZE WARNINGS AND/OR FROST ADVISORIES.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...EARLY MORNING IFR/LIFR CONDITIONS WILL BEGIN
IMPROVING THIS MORNING EVEN AS AN AREA OF RAIN MOVES ACROSS THE
AREA. COULD SEE MVFR CEILINGS LINGER THROUGH MUCH OF THE DAY BUT
THERE IS A BETTER CHANCE THAT CONDITIONS WILL BREAK OUT TO VFR FOR
AT LEAST A FEW HOURS. THERE IS A CHANCE OF THUNDERSTORMS ACROSS
MUCH OF NEW HAMPSHIRE LATE THIS AFTERNOON INTO EARLY THIS EVENING.
LOW CLOUDS MAY MAKE A RETURN VISIT TO COASTAL MAINE EARLY THIS
EVENING BUT THE PASSING OF A COLD FRONT DURING THE NIGHT WILL
LIKELY IMPROVE CONDITIONS TO VFR EVENTUALLY.
LONG TERM...MAINLY VFR CONDITIONS EXPECTED.
&&
.MARINE...
SHORT TERM...SOUTHERLY FLOW INCREASES TODAY THEN SHIFTS TO THE
WEST TONIGHT BEHIND A COLD FRONT. WEST WINDS COULD GUST TO AROUND
20 KT ON WEDNESDAY.
LONG TERM...WITH MAINLY OFFSHORE FLOW...WINDS AND SEAS EXPECTED
TO REMAIN BELOW SCA CRITERIA. STRONGEST WINDS AND HIGHEST SEAS
SHOULD BE WELL OFFSHORE.
&&
.FIRE WEATHER...
MOIST AIR AND WIDESPREAD WETTING RAIN TODAY WILL KEEP FIRE DANGER
CONDITIONS LOW. DRY AIR MOVES IN BEHIND A COLD FRONT TONIGHT...
LEADING TO MUCH DRIER CONDITIONS WEDNESDAY INTO THE WEEKEND.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
NEAR TERM UPDATE...EKSTER
AREA FORECAST DISCUSSION
NWS GRAY ME
535 AM EDT TUE MAY 19 2015
.SYNOPSIS...
SHOWERS ASSOCIATED WITH A WARM FRONT WILL SPREAD ACROSS THE REGION
THIS MORNING. SHOWERS AND THUNDERSTORMS WILL DEVELOP THIS
AFTERNOON AND EVENING AHEAD OF A COLD FRONT. A NORTHWEST FLOW
WILL DEVELOP BEHIND THE FRONT TONIGHT AND PROVIDE COOL BUT MOSTLY
QUIET WEATHER INTO THE WEEKEND.
&&
.NEAR TERM /TODAY/...
530AM UPDATE...
HAVE UPDATED HOURLY PRECIPITATION CHANCES BASED ON RECENT RADAR
TRENDS. MUCH OF THE AREA IS SEEING SHOWERS NOW EXCEPT THE
IMMEDIATE COAST. THIS WILL CHANGE SOON. BACK EDGE OF PRECIPITATION
MOVING INTO VERMONT NOW AND WILL REACH WESTERN NEW HAMPSHIRE
WITHIN THE NEXT 2 TO 3 HOURS.
ORIGINAL DISCUSSION...
AREA OF SHOWERS AND A FEW EMBEDDED THUNDERSTORMS IS MOVING THROUGH
THE HUDSON VALLEY EARLY THIS MORNING AND SHOULD ARRIVE IN NEW
HAMPSHIRE IN THE NEXT TWO HOURS BEFORE SPREADING EASTWARD ACROSS
THE REST OF NEW HAMPSHIRE AND WESTERN MAINE THIS MORNING. THIS
AREA OF PRECIPITATION IS ASSOCIATED WITH A WARM FRONT-LIKE
FEATURE IN THAT BEHIND IT DEWPOINTS ARE SURGING INTO THE MID 60S
WHILE THE COOL MARITIME AIR MASS AHEAD OF IT IS COOLER AND WITH
LOWER DEWPOINTS. BUT YOU WILL BE HARD PRESSED TO FIND A
NOTICEABLE WIND SHIFT OR PRESSURE TROUGH WITH IT. SUCH IS LIFE IN
NORTHERN NEW ENGLAND.
AREA OF RAIN WILL MOVE INTO THE MIDCOAST REGION OF MAINE LATE IN
THE MORNING AND PERSIST INTO THE AFTERNOON. WHILE NEW HAMPSHIRE
WILL SEE THE RAIN ENDING EARLIER IN THE MORNING. BREAKS IN THE
CLOUDS SHOULD ALLOW FOR PRETTY GOOD WARMING INTO THE MID TO UPPER
70S OVER WESTERN NEW HAMPSHIRE. THE COMBINATION OF THIS WARMING...
THE INCREASING LOW LEVEL MOISTURE... AND COOLING TEMPERATURES
ALOFT ASSOCIATED WITH A SHORTWAVE TROUGH WILL PROVIDE SUBSTANTIAL
INSTABILITY THIS AFTERNOON... PERHAPS THE BEST SEEN YET THIS
SEASON. CAPE APPROACHES OR EXCEEDS 1000 BY LATE THIS AFTERNOON AND
EARLY EVENING OVER VERMONT AND NEW HAMPSHIRE. JUST AS INSTABILITY
IS INCREASING... A COLD FRONT WILL BEGIN MOVING ACROSS NORTHERN
NEW ENGLAND FROM WEST TO EAST. THIS WILL PROVIDE LOW LEVEL
CONVERGENCE TO ADD LIFT TO THE EQUATION... AIDING IN THE
DEVELOPMENT OF THUNDERSTORMS. BEST INSTABILITY AND LIFT DOES NOT
ARRIVE UNTIL LATE IN THE DAY... SO THUNDERSTORM POTENTIAL SEEMS TO
BE MORE IN THE 4PM-8PM TIME PERIOD... WITH REMNANT STORMS LIKELY
MAINTAINING THEMSELVES THROUGH ELEVATED INSTABILITY THROUGH
MIDNIGHT TONIGHT.
MESOSCALE MODELS INCLUDING THE NAM AND HRRR INDICATING POTENTIALLY
TWO SEPARATE AREAS OF MORE WIDESPREAD THUNDERSTORM ACTIVITY LATE
THIS AFTERNOON. THE FIRST IS OVER THE NORTHERN ADIRONDACKS AND THE
SECOND OVER THE CATSKILLS... BOTH AREAS FIRING AS THE FRONT MOVES
THROUGH TO PROVIDE LIFT AND MAY BE ENHANCED DUE TO TERRAIN-BASED
INSTABILITY. IF THIS SCENARIO UNFOLDS... THEN THE NORTHERN AREA OF
THUNDERSTORMS WOULD MOVE EAST ACROSS VERMONT AND THE NORTHERN HALF
OF NEW HAMPSHIRE AND INTO NORTHWEST MAINE IN THE EVENING. THE
SOUTHERN CLUSTER WOULD MOVE EAST MAINLY INTO MASSACHUSETTS. HAVE
ORIENTED AFTERNOON/EVENING THUNDERSTORM CHANCES AS BEING GREATEST
IN THE NORTH WHERE THE MORE NORTHERN CLUSTER OF STORMS WOULD MOVE
ACROSS BUT HAVE MAINTAINED AT LEAST A CHANCE OF THUNDERSTORMS OVER
ALL OF NEW HAMPSHIRE AND EXTENDING INTO FAR WESTERN/NORTHERN
MAINE IN THE EVENING.
ONE FINAL INGREDIENT TO ADD TO THE MIX TODAY IS INCREASING WIND
SHEAR. BY EVENING... AROUND THE TIME THE FRONT WILL BE MOVING INTO
NEW HAMPSHIRE... WINDS ALOFT APPROACH 50 KT AT 700 MB WHILE
SURFACE WINDS ARE BROADLY LIGHT OUT OF THE SOUTH. THIS WILL
PROVIDE ENOUGH SPEED SHEAR TO PROVIDE STORM ORGANIZATION AND
SUPERCELL TYPE STRUCTURES. THIS MAKES SEVERE THUNDERSTORMS MORE
LIKELY... WITH DAMAGING WINDS AND HAIL BEING THE PRIMARY THREATS.
HOWEVER... GIVEN LOW LEVEL WINDS OUT OF THE SOUTH... CANNOT RULE
OUT THE POSSIBILITY OF AN ISOLATED TORNADO PARTICULARLY IN AREAS
WHERE LOW LEVEL WINDS ARE CHANNELED BY TERRAIN AND PRODUCE GREATER
LOCALIZED DIRECTIONAL SHEAR. HAVE MENTIONED THE THREAT OF DAMAGING
WINDS AND LARGE HAIL IN THE PUBLIC FORECAST FOR LATE THIS
AFTERNOON. HAVE ALSO ORIENTED HOURLY PRECIPITATION CHANCES TO
BETTER REFLECT THE IDEA THAT EARLY MORNING SHOWERS WILL MOVE EAST
BEFORE THE CHANCE OF THUNDERSTORMS ARRIVES LATE.
&&
.SHORT TERM /TONIGHT AND WEDNESDAY/...
COLD FRONT WILL PUSH EAST ACROSS THE REGION TONIGHT WITH
THUNDERSTORM ACTIVITY LIKELY LINGERING INTO THE EVENING...
POSSIBLY TO AROUND MIDNIGHT IN NORTHERN MAINE. COOLER AND DRIER
AIR WILL BE MOVING IN BEHIND THE COLD FRONT. COULD SEE SOME FOG
NEAR THE COAST BEFORE THE FRONT MOVES THROUGH AND BEGINS TO
MIX/DRY THINGS OUT. TEMPERATURES FALL INTO THE UPPER 40S AND LOW
50S.
WILL BE A COOLER DAY ON WEDNESDAY FOR MOST OF THE REGION. BUT ON
THE COAST IT MAY ACTUALLY BE A FEW DEGREES WARMER... A TYPICAL
RESULT OF A PASSING COLD FRONT AND A SHIFT TO OFFSHORE WINDS. HIGH
TEMPERATURES RANGE FROM THE MID 50S IN THE NORTH TO THE MID 60S
NEAR THE COAST. DEWPOINTS WILL BE FALLING INTO THE 30S WHICH WILL
MAKE IT DIFFICULT FOR ANY SHOWERS TO DEVELOP IN SPITE OF SOME LIFT
MOVING THROUGH WITH THE PASSING OF THE UPPER LEVEL TROUGH.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
A LARGE UPPER LEVEL TROUGH WILL DOMINATE THE FLOW ACROSS NEW
ENGLAND THROUGH THE WEEKEND. SEVERAL DISTURBANCES WILL ROTATE
AROUND THE TROUGH, HOWEVER, COOL DRY WEATHER WILL RULE FOR MUCH OF
THE PERIOD. A MOISTURE-STARVED FRONT DROPPING SOUTHWARD FROM
CANADA COULD BRING A FEW SHOWERS TO THE REGION FRIDAY. BEHIND THE
FRONT...TEMPERATURES WILL BE MAINLY IN THE 60S SATURDAY BUT SHOULD
START TO WARM INTO THE 70S MOST AREAS FOR SUNDAY AND MONDAY AS THE
TROUGH AXIS SLIDES EAST OF THE REGION. MODELS NOW DELAY NEXT
SIGNIFICANT PRECIPITATION UNTIL TUESDAY, ALLOWING FOR A VERY
PLEASANT HOLIDAY WEEKEND.
NOTE: THE FREEZE/FROST PROGRAM STARTS IN NORTHERN ZONES
THURSDAY MAY 21. LOW TEMPERATURES THURSDAY AND SATURDAY MORNINGS
WILL DROP NEAR OR BELOW FREEZING ACROSS NORTHERN ZONES AND MAY
REQUIRE FREEZE WARNINGS AND/OR FROST ADVISORIES.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...EARLY MORNING IFR/LIFR CONDITIONS WILL BEGIN
IMPROVING THIS MORNING EVEN AS AN AREA OF RAIN MOVES ACROSS THE
AREA. COULD SEE MVFR CEILINGS LINGER THROUGH MUCH OF THE DAY BUT
THERE IS A BETTER CHANCE THAT CONDITIONS WILL BREAK OUT TO VFR FOR
AT LEAST A FEW HOURS. THERE IS A CHANCE OF THUNDERSTORMS ACROSS
MUCH OF NEW HAMPSHIRE LATE THIS AFTERNOON INTO EARLY THIS EVENING.
LOW CLOUDS MAY MAKE A RETURN VISIT TO COASTAL MAINE EARLY THIS
EVENING BUT THE PASSING OF A COLD FRONT DURING THE NIGHT WILL
LIKELY IMPROVE CONDITIONS TO VFR EVENTUALLY.
LONG TERM...MAINLY VFR CONDITIONS EXPECTED.
&&
.MARINE...
SHORT TERM...SOUTHERLY FLOW INCREASES TODAY THEN SHIFTS TO THE
WEST TONIGHT BEHIND A COLD FRONT. WEST WINDS COULD GUST TO AROUND
20 KT ON WEDNESDAY.
LONG TERM...WITH MAINLY OFFSHORE FLOW...WINDS AND SEAS EXPECTED
TO REMAIN BELOW SCA CRITERIA. STRONGEST WINDS AND HIGHEST SEAS
SHOULD BE WELL OFFSHORE.
&&
.FIRE WEATHER...
MOIST AIR AND WIDESPREAD WETTING RAIN TODAY WILL KEEP FIRE DANGER
CONDITIONS LOW. DRY AIR MOVES IN BEHIND A COLD FRONT TONIGHT...
LEADING TO MUCH DRIER CONDITIONS WEDNESDAY INTO THE WEEKEND.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...KIMBLE
SHORT TERM...KIMBLE
LONG TERM...JENSENIUS
AREA FORECAST DISCUSSION
NWS GRAY ME
329 AM EDT TUE MAY 19 2015
.SYNOPSIS...
SHOWERS ASSOCIATED WITH A WARM FRONT WILL SPREAD ACROSS THE REGION
THIS MORNING. SHOWERS AND THUNDERSTORMS WILL DEVELOP THIS
AFTERNOON AND EVENING AHEAD OF A COLD FRONT. A NORTHWEST FLOW
WILL DEVELOP BEHIND THE FRONT TONIGHT AND PROVIDE COOL BUT MOSTLY
QUIET WEATHER INTO THE WEEKEND.
&&
.NEAR TERM /TODAY/...
AREA OF SHOWERS AND A FEW EMBEDDED THUNDERSTORMS IS MOVING THROUGH
THE HUDSON VALLEY EARLY THIS MORNING AND SHOULD ARRIVE IN NEW
HAMPSHIRE IN THE NEXT TWO HOURS BEFORE SPREADING EASTWARD ACROSS
THE REST OF NEW HAMPSHIRE AND WESTERN MAINE THIS MORNING. THIS
AREA OF PRECIPITATION IS ASSOCIATED WITH A WARM FRONT-LIKE
FEATURE IN THAT BEHIND IT DEWPOINTS ARE SURGING INTO THE MID 60S
WHILE THE COOL MARITIME AIR MASS AHEAD OF IT IS COOLER AND WITH
LOWER DEWPOINTS. BUT YOU WILL BE HARD PRESSED TO FIND A
NOTICEABLE WIND SHIFT OR PRESSURE TROUGH WITH IT. SUCH IS LIFE IN
NORTHERN NEW ENGLAND.
AREA OF RAIN WILL MOVE INTO THE MIDCOAST REGION OF MAINE LATE IN
THE MORNING AND PERSIST INTO THE AFTERNOON. WHILE NEW HAMPSHIRE
WILL SEE THE RAIN ENDING EARLIER IN THE MORNING. BREAKS IN THE
CLOUDS SHOULD ALLOW FOR PRETTY GOOD WARMING INTO THE MID TO UPPER
70S OVER WESTERN NEW HAMPSHIRE. THE COMBINATION OF THIS WARMING...
THE INCREASING LOW LEVEL MOISTURE... AND COOLING TEMPERATURES
ALOFT ASSOCIATED WITH A SHORTWAVE TROUGH WILL PROVIDE SUBSTANTIAL
INSTABILITY THIS AFTERNOON... PERHAPS THE BEST SEEN YET THIS
SEASON. CAPE APPROACHES OR EXCEEDS 1000 BY LATE THIS AFTERNOON AND
EARLY EVENING OVER VERMONT AND NEW HAMPSHIRE. JUST AS INSTABILITY
IS INCREASING... A COLD FRONT WILL BEGIN MOVING ACROSS NORTHERN
NEW ENGLAND FROM WEST TO EAST. THIS WILL PROVIDE LOW LEVEL
CONVERGENCE TO ADD LIFT TO THE EQUATION... AIDING IN THE
DEVELOPMENT OF THUNDERSTORMS. BEST INSTABILITY AND LIFT DOES NOT
ARRIVE UNTIL LATE IN THE DAY... SO THUNDERSTORM POTENTIAL SEEMS TO
BE MORE IN THE 4PM-8PM TIME PERIOD... WITH REMNANT STORMS LIKELY
MAINTAINING THEMSELVES THROUGH ELEVATED INSTABILITY THROUGH
MIDNIGHT TONIGHT.
MESOSCALE MODELS INCLUDING THE NAM AND HRRR INDICATING POTENTIALLY
TWO SEPARATE AREAS OF MORE WIDESPREAD THUNDERSTORM ACTIVITY LATE
THIS AFTERNOON. THE FIRST IS OVER THE NORTHERN ADIRONDACKS AND THE
SECOND OVER THE CATSKILLS... BOTH AREAS FIRING AS THE FRONT MOVES
THROUGH TO PROVIDE LIFT AND MAY BE ENHANCED DUE TO TERRAIN-BASED
INSTABILITY. IF THIS SCENARIO UNFOLDS... THEN THE NORTHERN AREA OF
THUNDERSTORMS WOULD MOVE EAST ACROSS VERMONT AND THE NORTHERN HALF
OF NEW HAMPSHIRE AND INTO NORTHWEST MAINE IN THE EVENING. THE
SOUTHERN CLUSTER WOULD MOVE EAST MAINLY INTO MASSACHUSETTS. HAVE
ORIENTED AFTERNOON/EVENING THUNDERSTORM CHANCES AS BEING GREATEST
IN THE NORTH WHERE THE MORE NORTHERN CLUSTER OF STORMS WOULD MOVE
ACROSS BUT HAVE MAINTAINED AT LEAST A CHANCE OF THUNDERSTORMS OVER
ALL OF NEW HAMPSHIRE AND EXTENDING INTO FAR WESTERN/NORTHERN
MAINE IN THE EVENING.
ONE FINAL INGREDIENT TO ADD TO THE MIX TODAY IS INCREASING WIND
SHEAR. BY EVENING... AROUND THE TIME THE FRONT WILL BE MOVING INTO
NEW HAMPSHIRE... WINDS ALOFT APPROACH 50 KT AT 700 MB WHILE
SURFACE WINDS ARE BROADLY LIGHT OUT OF THE SOUTH. THIS WILL
PROVIDE ENOUGH SPEED SHEAR TO PROVIDE STORM ORGANIZATION AND
SUPERCELL TYPE STRUCTURES. THIS MAKES SEVERE THUNDERSTORMS MORE
LIKELY... WITH DAMAGING WINDS AND HAIL BEING THE PRIMARY THREATS.
HOWEVER... GIVEN LOW LEVEL WINDS OUT OF THE SOUTH... CANNOT RULE
OUT THE POSSIBILITY OF AN ISOLATED TORNADO PARTICULARLY IN AREAS
WHERE LOW LEVEL WINDS ARE CHANNELED BY TERRAIN AND PRODUCE GREATER
LOCALIZED DIRECTIONAL SHEAR. HAVE MENTIONED THE THREAT OF DAMAGING
WINDS AND LARGE HAIL IN THE PUBLIC FORECAST FOR LATE THIS
AFTERNOON. HAVE ALSO ORIENTED HOURLY PRECIPITATION CHANCES TO
BETTER REFLECT THE IDEA THAT EARLY MORNING SHOWERS WILL MOVE EAST
BEFORE THE CHANCE OF THUNDERSTORMS ARRIVES LATE.
&&
.SHORT TERM /TONIGHT AND WEDNESDAY/...
COLD FRONT WILL PUSH EAST ACROSS THE REGION TONIGHT WITH
THUNDERSTORM ACTIVITY LIKELY LINGERING INTO THE EVENING...
POSSIBLY TO AROUND MIDNIGHT IN NORTHERN MAINE. COOLER AND DRIER
AIR WILL BE MOVING IN BEHIND THE COLD FRONT. COULD SEE SOME FOG
NEAR THE COAST BEFORE THE FRONT MOVES THROUGH AND BEGINS TO
MIX/DRY THINGS OUT. TEMPERATURES FALL INTO THE UPPER 40S AND LOW
50S.
WILL BE A COOLER DAY ON WEDNESDAY FOR MOST OF THE REGION. BUT ON
THE COAST IT MAY ACTUALLY BE A FEW DEGREES WARMER... A TYPICAL
RESULT OF A PASSING COLD FRONT AND A SHIFT TO OFFSHORE WINDS. HIGH
TEMPERATURES RANGE FROM THE MID 50S IN THE NORTH TO THE MID 60S
NEAR THE COAST. DEWPOINTS WILL BE FALLING INTO THE 30S WHICH WILL
MAKE IT DIFFICULT FOR ANY SHOWERS TO DEVELOP IN SPITE OF SOME LIFT
MOVING THROUGH WITH THE PASSING OF THE UPPER LEVEL TROUGH.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
A LARGE UPPER LEVEL TROUGH WILL DOMINATE THE FLOW ACROSS NEW
ENGLAND THROUGH THE WEEKEND. SEVERAL DISTURBANCES WILL ROTATE
AROUND THE TROUGH, HOWEVER, COOL DRY WEATHER WILL RULE FOR MUCH OF
THE PERIOD. A MOISTURE-STARVED FRONT DROPPING SOUTHWARD FROM
CANADA COULD BRING A FEW SHOWERS TO THE REGION FRIDAY. BEHIND THE
FRONT...TEMPERATURES WILL BE MAINLY IN THE 60S SATURDAY BUT SHOULD
START TO WARM INTO THE 70S MOST AREAS FOR SUNDAY AND MONDAY AS THE
TROUGH AXIS SLIDES EAST OF THE REGION. MODELS NOW DELAY NEXT
SIGNIFICANT PRECIPITATION UNTIL TUESDAY, ALLOWING FOR A VERY
PLEASANT HOLIDAY WEEKEND.
NOTE: THE FREEZE/FROST PROGRAM STARTS IN NORTHERN ZONES
THURSDAY MAY 21. LOW TEMPERATURES THURSDAY AND SATURDAY MORNINGS
WILL DROP NEAR OR BELOW FREEZING ACROSS NORTHERN ZONES AND MAY
REQUIRE FREEZE WARNINGS AND/OR FROST ADVISORIES.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...EARLY MORNING IFR/LIFR CONDITIONS WILL BEGIN
IMPROVING THIS MORNING EVEN AS AN AREA OF RAIN MOVES ACROSS THE
AREA. COULD SEE MVFR CEILINGS LINGER THROUGH MUCH OF THE DAY BUT
THERE IS A BETTER CHANCE THAT CONDITIONS WILL BREAK OUT TO VFR FOR
AT LEAST A FEW HOURS. THERE IS A CHANCE OF THUNDERSTORMS ACROSS
MUCH OF NEW HAMPSHIRE LATE THIS AFTERNOON INTO EARLY THIS EVENING.
LOW CLOUDS MAY MAKE A RETURN VISIT TO COASTAL MAINE EARLY THIS
EVENING BUT THE PASSING OF A COLD FRONT DURING THE NIGHT WILL
LIKELY IMPROVE CONDITIONS TO VFR EVENTUALLY.
LONG TERM...MAINLY VFR CONDITIONS EXPECTED.
&&
.MARINE...
SHORT TERM...SOUTHERLY FLOW INCREASES TODAY THEN SHIFTS TO THE
WEST TONIGHT BEHIND A COLD FRONT. WEST WINDS COULD GUST TO AROUND
20 KT ON WEDNESDAY.
LONG TERM...WITH MAINLY OFFSHORE FLOW...WINDS AND SEAS EXPECTED
TO REMAIN BELOW SCA CRITERIA. STRONGEST WINDS AND HIGHEST SEAS
SHOULD BE WELL OFFSHORE.
&&
.FIRE WEATHER...
MOIST AIR AND WIDESPREAD WETTING RAIN TODAY WILL KEEP FIRE DANGER
CONDITIONS LOW. DRY AIR MOVES IN BEHIND A COLD FRONT TONIGHT...
LEADING TO MUCH DRIER CONDITIONS WEDNESDAY INTO THE WEEKEND.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...KIMBLE
SHORT TERM...KIMBLE
LONG TERM...JENSENIUS
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
200 AM EDT TUE MAY 19 2015
.SYNOPSIS...
HIGH PRESSURE REMAINS ANCHORED OFF THE SOUTHEAST COAST THROUGH
TUESDAY. A COLD FRONT CROSSES THE REGION TUESDAY NIGHT. HIGH
PRESSURE BUILDS INTO THE AREA FROM THE WEST WEDNESDAY THROUGH
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
LATEST REGIONAL RADAR MOSAIC DEPICTS ISOLATED TO WIDELY SCATTERED
SHOWERS/THUNDERSTORMS ACROSS THE NW COUNTIES...WITH ANOTHER ISOLATED
THUNDERSTORM OVER HOPEWELL AS OF THIS WRITING. BETTER COVERAGE OF
SHOWERS AND THUNDERSTORMS FOUND JUST NORTH OF THE LOCAL AREA.
EARLIER THUNDERSTORMS HAVE LEFT BEHIND SEVERAL BOUNDARIES THIS
EVENING. WARM/HUMID AIRMASS REMAINS IN PLACE...WITH RAP MESOANALYSIS
DEPICTING 1000-1500 J/KG MLCAPE. BETTER FORCING ALOFT ALSO INDICATED
(ALBEIT LIMITED OVER THE LOCAL AREA) AS A SHORTWAVE VISIBLE ON WATER
VAPOR LIFTS ACROSS THE OH VALLEY. EXPECT THE BEST COVERAGE OF
SHOWERS/THUNDERSTORMS TO REMAIN NORTH OF THE LOCAL AREA
TONIGHT...BUT COMBINATION OF OUTFLOW BOUNDARIES AND
WARM/MOIST/RELATIVELY UNSTABLE AIRMASS WILL RESULT IN SLIGHT CHANCE-
CHANCE POPS THRU THE OVERNIGHT PERIOD. STORMS EXPECTED TO REMAIN SUB-
SEVERE DUE TO WEAK SHEAR PROFILES...BUT MEAN FLOW AOB 10 KT WILL
RESULT IN LOCALLY HEAVY RAINFALL.
BACKDOOR FRONT ALSO LOCATED OVER THE MD ERN SHORE THIS
EVENING...WITH ONSHORE FLOW OBSERVED AT OCEAN CITY WITH TEMPS
DROPPING INTO THE MID 60S. FOG OBSERVED DOV/GED/OXB...WITH
ADDITIONAL FOG EXPECTED THANKS TO ONSHORE FLOW. HAVE INCLUDED
AREAS OF FOG GENERALLY EAST OF HIGHWAY 13 IN MD. DO NOT ANTICIPATE
DENSE FOG ATTM. MILD TONIGHT WITH LOWS IN THE UPPER 60S TO AROUND
70 DEGREES. SKIES AVG PARTLY CLOUDY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY/...
A COLD FRONT MOVING THROUGH THE MIDWEST THIS AFTN WILL REACH THE
SPINE OF THE APPALACHIANS AROUND 12Z TUE. THE COLD FRONT THEN
CROSSES THE LOCAL AREA TUESDAY AFTN/EVE...BEFORE PUSHING OFFSHORE
TUE NIGHT. BULK SHEAR REMAINS MARGINAL AT BEST AND DOWNSLOPE FLOW
ALOFT IS LESS THAN IDEAL FOR WIDESPREAD CONVECTIVE DEVELOPMENT.
HOWEVER...STRONG SFC HEATING PRE-FRONTAL SHOULD YIELD ANOTHER
ROUND OF SCATTERED SHWRS/TSTMS IN THE AFTN/EVE. WARM AND HUMID
AGAIN TUE. HIGHS FROM THE MID 80S TO AROUND 90 (EXCEPT COOLER AT
THE IMMEDIATE COAST). LOWS TUE NIGHT IN THE 60S.
COOL/DRY HIGH PRESSURE BEGINS TO BUILD TOWARD THE AREA FROM THE
WEST ON WEDNESDAY...YIELDING A DRIER/MORE COMFORTABLE DAY WITH
PLENTY OF SUNSHINE. HIGH TEMPS FROM THE MID 70S NORTH TO THE LOW
80S SOUTH. COMFORTABLE WED NIGHT WITH LOWS IN THE MID 50S TO LOW
60S. SHORTWAVE ENERGY DIVES SOUTH INTO THE CAROLINAS ON THURSDAY
WITH WEAK SFC LOW PRESSURE DEVELOPING ALONG A STALLED FRONTAL
BOUNDARY. MOISTURE ASSOCIATED WITH THIS SYSTEM WILL GET SHOVED
NORTHWARD INTO THE LOCAL AREA...ESPECIALLY IN THE AFTN/EVE. WILL
CONTINUE TO CARRY CHC POPS FOR MUCH OF THE AREA. HOWEVER...IT
APPEARS THE HIGHEST LIKELIHOOD OF PCPN WILL BE ACROSS SE PARTS OF
THE FA. PLEASANT TEMPS ON THU WITH HIGHS MOSTLY IN THE 70S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
MEDIUM RANGE BEGINS WITH LATEST GFS/ECMWF INTO GOOD AGREEMENT WITH
WEAK UPPER TROUGH AXIS CROSSING THE REGION THU NIGHT...AND SFC LOW
PRESSURE SLIDING OFF THE COAST. WILL MAINTAIN LOW CHC POPS THU
NIGHT...AND SLIGHT CHC POPS THROUGH FRI MORNING IN THE FAR SE.
OTHERWISE. HIGH PRESSURE THEN GRADUALLY BUILDS ESE FROM THE UPPER
MIDWEST FRI-SAT...AND SLIDES OFF THE COAST ON SUN. THIS WILL RESULT
IN DRY CONDITIONS WITH COOLER TEMPERATURES FRI/SAT...PARTICULARLY AT
THE COAST ON SAT AS THE STRENGTH OF THE HIGH IS FAIRLY IMPRESSIVE...1030
MB+ AND ONSHORE FLOW INCREASES IN THE AFTN AS A PIECE OF THE HIGH
BECOMES CENTERED JUST OFFSHORE. SKIES WILL AVG MOSTLY SUNNY BOTH
DAYS ASIDE FROM SOME LINGERING CLOUDS FRI MORNING. HIGHS FRI WILL
BE FROM 75-80 F INLAND...TO 70-75 F NEAR THE COAST...TRENDING DOWN
TO THE MID 70S SAT INLAND TO ONLY THE UPPER 60S/LOWER 70S AT THE
COAST. LOWS WILL GENLY RANGE THROUGH THE 50S SAT AND SUN MORNING. FLOW
TURNS AROUND TO THE SSW SUN/MON AS SFC HIGH PUSHES WELL OFFSHORE
AND UPPER RIDGE AXIS MOVES BACK INTO THE REGION. HIGHS WARM BACK
INTO THE LWR 80S INLAND ON SUN...AND 85-90 F BY MON. CONDITIONS
BOTH DAYS WILL BE ABOUT 5 DEGREES COOLER AT THE COAST. WILL KEEP
FORECAST DRY THROUGH MIDDAY MON...THEN CARRY 20-30% POPS ACRS THE
NORTH BY MON AFTN.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
WILL MAINTAIN MAINLY VFR CONDITIONS AT ALL TAF SITES THRU THE 06Z
TAF PERIOD. ALTHO...EXPECT MVFR AND EVEN IFR CONDITIONS AT SBY
THRU EARLY THIS MORNG...DUE TO AREA OF SHOWERS AND POSSIBLY A TSTM
MOVNG THRU. OTHERWISE...WILL HAVE A VCSH AT OTHER TAF SITES DUE TO
CURRENT ACTIVITY ON RADAR...AND LINGERING INSTABILITY/BOUNDARIES
WITH SURFACE TROF CROSSING THE REGION.
CONTINUED CHCS FOR SHOWERS/TSTMS DURING TODAY...AS A COLD FRONT
APPROACHES AND MOVES ACRS THE AREA. FOR NOW...HAVE A VCSH STARTING
AT 16Z-18Z AT THE TAF SITES AND CONTINUING INTO EARLY THIS EVENG.
FRONT PUSHES OFF THE CST TNGT INTO WED MORNG...WITH NORTHERLY
WINDS BEHIND THE BOUNDARY USHERING DRIER AIR INTO THE REGION. VFR
CONDITIONS THEN EXPECTED THRU WED...AS HI PRES BLDS INTO THE AREA.
NEXT THREAT FOR SHOWERS/TSTMS WILL BE THU...AS A SHRTWV TROF
MOVES ACRS THE REGION.
&&
.MARINE...
WEAK SFC TROUGH OVER THE WATERS...WITH GENLY A LIGHT ONSHORE FLOW
LESS THAN 10 KT...THOUGH WIND DIRECTIONS ARE SOMEWHAT CHAOTIC DUE
TO SCATTERED TSTMS AND VERY WEAK PRESSURE GRADIENT. WINDS WIND
SHIFT TO BECOME A BIT MORE ORGANIZED FROM THE S/SE LATER THIS
EVENING...AND S/SW OVERNIGHT BUT SPEEDS AVG 10 KT OR LESS WITH
SEAS ONLY 2-3 FT AND WAVES IN THE BAY ONLY AROUND 1 FOOT (1-2 FT
MOUTH OF BAY). A COLD FRONT PUSHES ACROSS THE WATERS LATE TUE
(WITH PSBL SHRAS/TSTMS). WINDS BECOME N-NW POST- FRONTAL TUE
NIGHT. NOT A REAL STRONG COLD FRONT...BUT DOES APPEAR TO BE
SUFFICIENT COOL AIR SURGE TO LEAD TO LOW END SCA CONDITIONS FOR
THE BAY (AND PERHAPS THE RIVERS/SOUND). AT THIS TIME...KEEPING
CONDS BELOW SCA FOR THE OCEAN. IT WILL TEND TO BE FAIRLY SHORT IN
DURATION (AROUND 6 HRS..FROM AROUND 3-4 AM/WED THROUGH LATE
MORNING OR NOON/WED). SFC HI PRES BUILDS INTO THE RGN FM THE W WED
NIGHT...WITH A WEAK LOW PRESSURE SYSTEM PASSING BY TO THE SOUTH ON
THU. SOME UNCERTAINTY ON EXACT TRACK OF THIS SYSTEM...FOR NOW
MODELS KEEP WINDS FAIRLY LIGHT...10-15 KT AT MOST ALTHOUGH THIS
COULD CHANGE. HIGH PRESSURE THEN BUILDS OVER THE AREA LATER FRI-
SUN...FAIRLY COOL AIRMASS INITIALLY WILL LIKELY BRING SOME
INCREASE IN WINDS FRI NIGHT INTO SAT.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDM
NEAR TERM...JDM/SAM
SHORT TERM...JDM/MAS
LONG TERM...LKB
AVIATION...TMG
MARINE...LKB
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1114 PM EDT WED MAY 20 2015
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 329 PM EDT WED MAY 20 2015
COOLER THAN NORMAL WEATHER WILL CONTINUE THE REST OF THE WORK
WEEK...WITH FROST A GOOD BET EACH NIGHT ACROSS PORTIONS OF CENTRAL
LOWER MICHIGAN. SOME LIGHT RAIN SHOWERS OR SPRINKLES ARE POSSIBLE
ALONG INTERSTATE 94 THIS EVENING INTO TONIGHT. ANY RAINFALL AMOUNTS
WILL BE VERY LIGHT. AFTER A DRY AND PARTLY TO MOSTLY SUNNY DAY ON
THURSDAY SOME LIGHT RAIN SHOWERS WILL MOVE THROUGH THE AREA THURSDAY
NIGHT ALONG AND AHEAD OF A COLD FRONTAL PASSAGE. WARMER AIR WILL
MOVE IN FOR THE HOLIDAY WEEKEND WITH CHANCES FOR SHOWERS AND STORMS
RETURNING FOR SUNDAY INTO MEMORIAL DAY. HIGHS WILL REMAIN IN THE 60S
THE REST OF THE WORK WEEK RISING INTO THE 70S FOR SUNDAY AND
MEMORIAL DAY.
&&
.UPDATE...
ISSUED AT 604 PM EDT WED MAY 20 2015
ADDED CHANCE OF A MIX OF LIGHT RAIN AND SLEET TO THE FORECAST
THIS EVENING ACROSS THE SOUTHERN CWA PER NUMEROUS REPORTS OF A
RAIN/SLEET MIX IN THE CHICAGO AREA. AFTER THE PRECIP MOVED
IN...SOUTH HAVEN DROPPED TO 41 DEGREES REPORTING UP. THE FORECAST
IS DRY AFTER 06Z.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 329 PM EDT WED MAY 20 2015
SHORT TERM FOCUS WAS ON CHANCES FOR RAIN IN THE SOUTH THIS
EVENING...FROST POTENTIAL ACROSS CENTRAL LOWER MI TONIGHT AND THE
CHANCE FOR RAIN THURSDAY NIGHT WITH THE NEXT FRONT.
DECIDED TO ADD A MENTION OF LIGHT RAIN SHOWERS ALONG INTERSTATE 94
THIS EVENING AFTER ALL. HI-RES MODELS LIKE THE HRRR CONTINUE TO
INDICATE RAIN MAKING IT INTO OUR CWA...AND UPSTREAM RADAR TRENDS
WOULD AGREE. THAT SAID DRY AIR OVER LOWER MICHIGAN WILL TRY TO ERODE
IT AS IT MOVES IN. DEW POINT DEPRESSIONS AT THE SURFACE ACROSS THE
GRR CWA ARE IN EXCESS OF 20F IN MOST AREAS. PRECIP IS JUST TOO CLOSE
AT THIS POINT TO IGNORE. HAVE 20 PCT WORDING ALONG I-94 FOR NOW. WE
WILL BE WATCHING TO SEE IF IT MAKES IT INTO THE CWA AS WELL AS IF IT
TRENDS FURTHER NORTH TOWARDS I-96 WHICH THE HRRR CONTINUES TO SHOW
AS WELL.
OPTED TO ISSUE A FROST ADVISORY ACROSS THE FAR NORTHERN ROW OF
COUNTIES ALONG U.S. 10. CLOUDS WILL CLEAR OUT UP THERE OVERNIGHT
WITH VERY DRY AIR IN PLACE. VERY COLD READINGS OCCURRED LAST NIGHT
UP THERE AND THE AIR MASS HAS NOT CHANGED. FROST AND FREEZING
TEMPERATURES WILL BE POSSIBLE THE NEXT COUPLE NIGHTS UP THERE AS
WELL...THURSDAY NIGHT AND FRIDAY NIGHT.
A COLD FRONT WILL SWING THROUGH LOWER MICHIGAN THURSDAY NIGHT WITH
ALL OF THE SHORT TERM MODELS KICKING OUT SOME LIGHT PRECIPITATION.
THE COLD FRONT IS ASSOCIATED WITH AN UPPER LOW DRIFTING SOUTHEAST
ACROSS ONTARIO. MAY BE JUST ENOUGH MOISTURE AND LIFT FOR A FEW
SHOWERS. WILL CARRY 30 PCT CHANCES FOR RAIN THURSDAY NIGHT.
OTHERWISE QUIET WEATHER IS EXPECTED DURING THE DAY ON THURSDAY AND
AGAIN FRIDAY AND FRIDAY NIGHT.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 329 PM EDT WED MAY 20 2015
MULTIPLE ROUNDS OF SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE LATE
SUNDAY THROUGH WEDNESDAY. THE WEATHER WILL TREND WARMER AND MORE
HUMID THIS WEEKEND INTO THE MIDDLE OF NEXT WEEK.
SATURDAY IS SHAPING UP TO BE A BEAUTIFUL DAY WITH SURFACE HIGH
PRESSURE SLIDING OFF TO THE SOUTHEAST AND AN UPPER RIDGE BUILDING
INTO THE GREAT LAKES REGION. SOUTHWESTERLY RETURN FLOW SETS UP ON
SATURDAY...AND LOWER MICHIGAN WILL FINALLY START TO WARM UP AFTER A
COOL WEEK. HIGHS SHOULD BE AROUND 70 ON SATURDAY.
TEMPS WILL BE WARMER STILL ON SUNDAY AS A WARM FRONT APPROACHES FROM
THE SOUTH. TIMING DIFFERENCES EXIST BETWEEN THE LATEST GFS AND EURO.
THE 12Z EURO KEEPS SW LOWER MI MOSTLY DRY ON SUNDAY...WITH PERHAPS
SOME LIGHT RAIN MOVING INTO THE EXTREME SW CWA SUNDAY EVENING. THE
GFS IS MUCH WETTER SUNDAY. I WOULD DEFINITELY FAVOR A DRY SUNDAY
MORNING WITH PRECIP CHANCES INCREASING SUNDAY EVENING AND ESPECIALLY
SUNDAY NIGHT. SHOWERS AND THUNDERSTORMS ARE EXPECTED SUNDAY NIGHT
THROUGH WEDNESDAY...WITH SOME BREAKS IN THERE OF COURSE. CONFIDENCE
IN SEVERE WEATHER IS LOW AT THIS TIME...BUT SOME INSTABILITY DOES
DEVELOP MONDAY AFTERNOON AND EVENING PRIMARILY SOUTH OF I-96 ALONG
WITH 30-40 KNOTS OF 0-6 KM BULK SHEAR. HIGHS MONDAY THROUGH
WEDNESDAY OF NEXT WEEK SHOULD BE IN THE MID TO UPPER 70S. 80
DEGREES SEEMS POSSIBLE ON WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1111 PM EDT WED MAY 20 2015
THE RAIN IS PULLING AWAY FROM KJXN AT THIS TIME AND WILL LIKELY BE
EAST OF THIS SITE BY 06Z. THUS TONIGHTS TAFS WILL BE DRY WITH VFR
WEATHER EVEN INTO THU.
A COLD FRONT DROPS DOWN FROM THE NORTHWEST THURSDAY EVENING. SOME
INSTABILITY IS SHOWING UP FOR LOCATIONS NORTH OF KMKG AND KGRR.
THUS TAF SITES WILL NOT FEATURE THUNDER...ONLY VCSH. WILL NEED TO
MONITOR THE WIND GUSTS POTENTIAL AS DRY LOW LEVEL AIRMASSES
SOMETIMES SUPPORT GUSTY WINDS IF SHOWERS DO EVENTUALLY DEVELOP.
&&
.MARINE...
ISSUED AT 329 PM EDT WED MAY 20 2015
NOT EXPECTING SIGNIFICANT WINDS OR WAVES THE NEXT SEVERAL DAYS.
WINDS WILL COME UP A BIT THIS EVENING FROM HOLLAND SOUTH AND THEN
AGAIN THURSDAY AFTERNOON AND EVENING AHEAD OF A COLD FRONTAL
PASSAGE. IN BOTH CASES EXPECTING WINDS AND WAVES TO REMAIN BELOW
SMALL CRAFT ADVISORY THRESHOLDS. WAVES MAY RISE INTO THE 2-3 FOOT
RANGE DURING THE AFOREMENTIONED TIMES.
&&
.HYDROLOGY...
ISSUED AT 1139 AM EDT WED MAY 20 2015
NO REAL IMPACTS ARE EXPECTED IN THE NEAR FUTURE. RIVERS ARE STABLE
OR SLOWLY FALLING. ONLY SLIGHT CHANCES OF RAIN EXIST LATE THURSDAY
INTO EARLY FRIDAY. ANY MEANINGFUL PRECIPITATION IS EXPECTED TO
HOLD OFF UNTIL AT LEAST SUNDAY.
BY SUNDAY...CHANCES FOR PRECIPITATION WILL INCREASE AS A WARM
FRONT LIFTS NORTH AND BECOMES STATIONARY SOMEWHERE OVER THE GREAT
LAKES REGION. THE PLACEMENT OF THIS BOUNDARY...AND THE POSSIBILITY
OF IT MEANDERING A BIT...MAY PROVIDE MULTIPLE CHANCES FOR RAIN
THROUGH MUCH OF NEXT WEEK. THIS WILL BE SOMETHING TO MONITOR AND
UPDATES WILL BE PROVIDED AS WE GET CLOSER TO THE WEEKEND.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...FROST ADVISORY UNTIL 8 AM EDT THURSDAY FOR MIZ037>040.
LM...NONE.
&&
$$
UPDATE...EBW
SYNOPSIS...DUKE
SHORT TERM...DUKE
LONG TERM...EBW
AVIATION...MJS
HYDROLOGY...JAM
MARINE...DUKE
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
710 PM EDT WED MAY 20 2015
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 329 PM EDT WED MAY 20 2015
COOLER THAN NORMAL WEATHER WILL CONTINUE THE REST OF THE WORK
WEEK...WITH FROST A GOOD BET EACH NIGHT ACROSS PORTIONS OF CENTRAL
LOWER MICHIGAN. SOME LIGHT RAIN SHOWERS OR SPRINKLES ARE POSSIBLE
ALONG INTERSTATE 94 THIS EVENING INTO TONIGHT. ANY RAINFALL AMOUNTS
WILL BE VERY LIGHT. AFTER A DRY AND PARTLY TO MOSTLY SUNNY DAY ON
THURSDAY SOME LIGHT RAIN SHOWERS WILL MOVE THROUGH THE AREA THURSDAY
NIGHT ALONG AND AHEAD OF A COLD FRONTAL PASSAGE. WARMER AIR WILL
MOVE IN FOR THE HOLIDAY WEEKEND WITH CHANCES FOR SHOWERS AND STORMS
RETURNING FOR SUNDAY INTO MEMORIAL DAY. HIGHS WILL REMAIN IN THE 60S
THE REST OF THE WORK WEEK RISING INTO THE 70S FOR SUNDAY AND
MEMORIAL DAY.
&&
.UPDATE...
ISSUED AT 604 PM EDT WED MAY 20 2015
ADDED CHANCE OF A MIX OF LIGHT RAIN AND SLEET TO THE FORECAST
THIS EVENING ACROSS THE SOUTHERN CWA PER NUMEROUS REPORTS OF A
RAIN/SLEET MIX IN THE CHICAGO AREA. AFTER THE PRECIP MOVED
IN...SOUTH HAVEN DROPPED TO 41 DEGREES REPORTING UP. THE FORECAST
IS DRY AFTER 06Z.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 329 PM EDT WED MAY 20 2015
SHORT TERM FOCUS WAS ON CHANCES FOR RAIN IN THE SOUTH THIS
EVENING...FROST POTENTIAL ACROSS CENTRAL LOWER MI TONIGHT AND THE
CHANCE FOR RAIN THURSDAY NIGHT WITH THE NEXT FRONT.
DECIDED TO ADD A MENTION OF LIGHT RAIN SHOWERS ALONG INTERSTATE 94
THIS EVENING AFTER ALL. HI-RES MODELS LIKE THE HRRR CONTINUE TO
INDICATE RAIN MAKING IT INTO OUR CWA...AND UPSTREAM RADAR TRENDS
WOULD AGREE. THAT SAID DRY AIR OVER LOWER MICHIGAN WILL TRY TO ERODE
IT AS IT MOVES IN. DEW POINT DEPRESSIONS AT THE SURFACE ACROSS THE
GRR CWA ARE IN EXCESS OF 20F IN MOST AREAS. PRECIP IS JUST TOO CLOSE
AT THIS POINT TO IGNORE. HAVE 20 PCT WORDING ALONG I-94 FOR NOW. WE
WILL BE WATCHING TO SEE IF IT MAKES IT INTO THE CWA AS WELL AS IF IT
TRENDS FURTHER NORTH TOWARDS I-96 WHICH THE HRRR CONTINUES TO SHOW
AS WELL.
OPTED TO ISSUE A FROST ADVISORY ACROSS THE FAR NORTHERN ROW OF
COUNTIES ALONG U.S. 10. CLOUDS WILL CLEAR OUT UP THERE OVERNIGHT
WITH VERY DRY AIR IN PLACE. VERY COLD READINGS OCCURRED LAST NIGHT
UP THERE AND THE AIR MASS HAS NOT CHANGED. FROST AND FREEZING
TEMPERATURES WILL BE POSSIBLE THE NEXT COUPLE NIGHTS UP THERE AS
WELL...THURSDAY NIGHT AND FRIDAY NIGHT.
A COLD FRONT WILL SWING THROUGH LOWER MICHIGAN THURSDAY NIGHT WITH
ALL OF THE SHORT TERM MODELS KICKING OUT SOME LIGHT PRECIPITATION.
THE COLD FRONT IS ASSOCIATED WITH AN UPPER LOW DRIFTING SOUTHEAST
ACROSS ONTARIO. MAY BE JUST ENOUGH MOISTURE AND LIFT FOR A FEW
SHOWERS. WILL CARRY 30 PCT CHANCES FOR RAIN THURSDAY NIGHT.
OTHERWISE QUIET WEATHER IS EXPECTED DURING THE DAY ON THURSDAY AND
AGAIN FRIDAY AND FRIDAY NIGHT.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 329 PM EDT WED MAY 20 2015
MULTIPLE ROUNDS OF SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE LATE
SUNDAY THROUGH WEDNESDAY. THE WEATHER WILL TREND WARMER AND MORE
HUMID THIS WEEKEND INTO THE MIDDLE OF NEXT WEEK.
SATURDAY IS SHAPING UP TO BE A BEAUTIFUL DAY WITH SURFACE HIGH
PRESSURE SLIDING OFF TO THE SOUTHEAST AND AN UPPER RIDGE BUILDING
INTO THE GREAT LAKES REGION. SOUTHWESTERLY RETURN FLOW SETS UP ON
SATURDAY...AND LOWER MICHIGAN WILL FINALLY START TO WARM UP AFTER A
COOL WEEK. HIGHS SHOULD BE AROUND 70 ON SATURDAY.
TEMPS WILL BE WARMER STILL ON SUNDAY AS A WARM FRONT APPROACHES FROM
THE SOUTH. TIMING DIFFERENCES EXIST BETWEEN THE LATEST GFS AND EURO.
THE 12Z EURO KEEPS SW LOWER MI MOSTLY DRY ON SUNDAY...WITH PERHAPS
SOME LIGHT RAIN MOVING INTO THE EXTREME SW CWA SUNDAY EVENING. THE
GFS IS MUCH WETTER SUNDAY. I WOULD DEFINITELY FAVOR A DRY SUNDAY
MORNING WITH PRECIP CHANCES INCREASING SUNDAY EVENING AND ESPECIALLY
SUNDAY NIGHT. SHOWERS AND THUNDERSTORMS ARE EXPECTED SUNDAY NIGHT
THROUGH WEDNESDAY...WITH SOME BREAKS IN THERE OF COURSE. CONFIDENCE
IN SEVERE WEATHER IS LOW AT THIS TIME...BUT SOME INSTABILITY DOES
DEVELOP MONDAY AFTERNOON AND EVENING PRIMARILY SOUTH OF I-96 ALONG
WITH 30-40 KNOTS OF 0-6 KM BULK SHEAR. HIGHS MONDAY THROUGH
WEDNESDAY OF NEXT WEEK SHOULD BE IN THE MID TO UPPER 70S. 80
DEGREES SEEMS POSSIBLE ON WEDNESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 706 PM EDT WED MAY 20 2015
BASED ON RADAR TRENDS...WENT WITH MORE RAIN IN THE TAFS FOR THIS
EVENING. BY MIDNIGHT MOST OF THE RAIN SHOULD BE EAST OF THE TAF
SITES. IMPACTS SHOULD BE LIMITED GIVEN THE LACK OF LOW LEVEL
MOISTURE...HOWEVER KLWA EARLIER DID GO IFR WITH LIKELY GS. THE IS
LOOKING VFR WITH DRY AIR ADVECTION OCCURRING.
&&
.MARINE...
ISSUED AT 329 PM EDT WED MAY 20 2015
NOT EXPECTING SIGNIFICANT WINDS OR WAVES THE NEXT SEVERAL DAYS.
WINDS WILL COME UP A BIT THIS EVENING FROM HOLLAND SOUTH AND THEN
AGAIN THURSDAY AFTERNOON AND EVENING AHEAD OF A COLD FRONTAL
PASSAGE. IN BOTH CASES EXPECTING WINDS AND WAVES TO REMAIN BELOW
SMALL CRAFT ADVISORY THRESHOLDS. WAVES MAY RISE INTO THE 2-3 FOOT
RANGE DURING THE AFOREMENTIONED TIMES.
&&
.HYDROLOGY...
ISSUED AT 1139 AM EDT WED MAY 20 2015
NO REAL IMPACTS ARE EXPECTED IN THE NEAR FUTURE. RIVERS ARE STABLE
OR SLOWLY FALLING. ONLY SLIGHT CHANCES OF RAIN EXIST LATE THURSDAY
INTO EARLY FRIDAY. ANY MEANINGFUL PRECIPITATION IS EXPECTED TO
HOLD OFF UNTIL AT LEAST SUNDAY.
BY SUNDAY...CHANCES FOR PRECIPITATION WILL INCREASE AS A WARM
FRONT LIFTS NORTH AND BECOMES STATIONARY SOMEWHERE OVER THE GREAT
LAKES REGION. THE PLACEMENT OF THIS BOUNDARY...AND THE POSSIBILITY
OF IT MEANDERING A BIT...MAY PROVIDE MULTIPLE CHANCES FOR RAIN
THROUGH MUCH OF NEXT WEEK. THIS WILL BE SOMETHING TO MONITOR AND
UPDATES WILL BE PROVIDED AS WE GET CLOSER TO THE WEEKEND.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...FROST ADVISORY FROM 2 AM TO 8 AM EDT THURSDAY FOR MIZ037>040.
LM...NONE.
&&
$$
UPDATE...EBW
SYNOPSIS...DUKE
SHORT TERM...DUKE
LONG TERM...EBW
AVIATION...MJS
HYDROLOGY...JAM
MARINE...DUKE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
408 PM EDT TUE MAY 19 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 407 PM EDT TUE MAY 19 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE OVER
WRN CANADA AND A DOWNSTREAM TROUGH FROM ERN CANADA INTO THE NRN
GREAT LAKES. STRONG MID-LEVEL DRYING WAS EVIDENT THROUGH THE NORTHERN
LAKES BEHIND A SHORTWAVE TROUGH THAT HAS MOVED EAST OF LAKE
SUPERIOR. AT THE SFC...HIGH PRES OVER THE ERN DAKOTAS WAS BUILDING
INTO THE UPPER MS VALLEY AN WRN LAKES BRINGING DIMINISHING NW WINDS
AND CLEARING SKIES. VIS LOOP SHOWED CLEAR SKIES OVER THE WEST AND
THINNING CLOUDS CENTRAL. RADAR ALSO INDICATED THAT THE REMAINING -
SHSN HAD QUICKLY DISSIPATED WITH ONLY SOME ISOLD FLURRIES OVER THE
EAST.
TONIGHT...AS THE HIGH PRES RIDGE BUILDS FROM WI INTO LOWER
MI...EXPECT SKIES TO CLEAR AND WEST WINDS TO DIMINISH/DECOUPLE.
FAVORABLE RADIATIONAL COOLING CONDITIONS WITH PWAT VALUES AT OR
BELOW 0.25 INCH WILL ALLOW TEMPS TO DROP TOWARD THE LOWER END OF
GUIDANCE. MIN READINGS INTO THE MID TO UPPER 20S INLAND ARE EXPECTED
TO TEMPS TO AROUND 30 CLOSER TO THE LAKES. ALTHOUGH OUR FROST/FREEZE
PROGRAM HAS NOT STARTED YET...WOULD EXPECT A WIDESPREAD FROST ACROSS
UPPER MICHIGAN AND A HARD FREEZE OVER THE INTERIOR WEST. AN SPS HAS
BEEN ISSUED TO HIGHLIGHT THE EXPECTED CONDITIONS.
WEDNESDAY...WITH DRY HIGH PRES DOMINATING...ABUNDANT SUNSHINE AND
MIXING TO AROUND 6K FT (850 MB TEMPS AROUND 4C) WILL SUPPORT INLAND
HIGHS IN TOE LOW TO MID 60S. LAKE BREEZES WILL KEEP READINGS IN THE
50S ALONG THE GREAT LAKES.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 328 PM EDT TUE MAY 19 2015
A QUIET FIRST HALF OF THE LONG TERM PERIOD IS IN STORE FOR THE UPPER
GREAT LAKES REGION...DUE TO THE AREA BEING BETWEEN AN UPPER TROUGH
OVER EASTERN CANADA AND ANOTHER OVER THE SOUTHWESTERN
CONUS. WHILE THE UPPER GREAT LAKES REGION WILL BE BRUSHED BY A FEW
WAVES ASSOCIATED WITH THESE FEATURES...THE OVERALL FLOW WILL BE OUT
OF THE NORTHWEST OR WEST-NORTHWEST WITH LIMITED MOISTURE.
HIGH PRESSURE WILL DOMINATE MUCH OF THE WEDNESDAY TO SATURDAY
PERIOD...WITH TEMPERATURES GENERALLY RUNNING BELOW NORMAL
(ESPECIALLY NEAR LAKE SUPERIOR). THE ONLY SIGNIFICANT ITEM OF NOTE
IS A COLD FRONT THAT WILL DROP SOUTH ACROSS THE REGION ON WEDNESDAY
NIGHT AND THURSDAY. WITH MOISTURE CONTINUING TO LOOK LIMITED...WILL
JUST SHOW PARTLY CLOUDY SKIES AS IT MOVES THROUGH THE AREA. THERE
ARE SOME HINTS THAT DIURNAL HEATING MAY BE ENOUGH TO KICK OFF A
STRAY SHOWER OVER SOUTHERN MENOMINEE COUNTY (MORE LIKELY IN
NORTHEAST WISCONSIN) WITH SOME HELP FROM A LAKE BREEZE OFF THE BAY
OF GREEN BAY. DON/T HAVE ENOUGH CONFIDENCE TO INCLUDE POPS FOR
ANY FARTHER NORTH THAN THE CITY OF MENOMINEE...BUT IT WILL BE
SOMETHING TO WATCH. ANOTHER BRIEF COOL DOWN IS EXPECTED BEHIND THE
FRONT WITH THE NORTHERLY FLOW OFF LAKE SUPERIOR BEFORE HIGHS SLOWLY
RISE TOWARDS MORE NORMAL VALUES ON SATURDAY (DUE TO THE HIGH
DEPARTING AND SOUTHERLY FLOW STARTING TO DEVELOP.
MODELS REMAIN CONSISTENT ON ENERGY FROM THE SOUTHWESTERN CONUS
TROUGH EJECTING NORTHEAST TOWARDS THE AREA SATURDAY NIGHT INTO
EARLY NEXT WEEK. A SURFACE LOW DEVELOPING IN THE PLAINS WITH THIS
FEATURE WILL MOVE INTO IOWA BY SUNDAY NIGHT BEFORE LIFTING
NORTHEAST THROUGH THE GREAT LAKES REGION MONDAY INTO MONDAY NIGHT.
THE LATEST TREND IS FOR THE LOW AND ASSOCIATED UPPER LEVEL WAVE TO
LIFT FARTHER TO THE NORTH THAN THOUGHT YESTERDAY...SO WILL TREND
POPS UP ON SUNDAY NIGHT AND MONDAY AS THE LOW MOVES THROUGH.
INSTABILITY AND MID LEVEL LAPSE RATES REMAIN WEAK DURING THAT
PERIOD...WITH THE AREA GENERALLY ON THE NORTHWEST SIDE OF THE
SURFACE LOW...SO WILL KEEP THUNDER OUT OF THE FORECAST. NEXT WEEK
STILL LOOKS TO BE UNSETTLED...AS THE UPPER TROUGH IN THE SOUTHWEST
CONUS WEAKENS AND LIFTS THROUGH THE CENTRAL CONUS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 128 PM EDT TUE MAY 19 2015
AS HIGH PRESSURE BUILDS TOWARD THE AREA...EXPECT VFR CONDITIONS WITH
MUCH DRIER AIR AND MIXING AT KIWD AND INTO KCMX AND KSAW MID TO LATE
AFTERNOON AS NNW GRADUALLY DIMINISH.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 407 PM EDT TUE MAY 19 2015
AS HIGH PRES BUILDS ACROSS THE REGION FROM THE WEST AND THE PRES
GRADIENT WEAKENS...WINDS WILL DIMINISH TO LESS THAN 20 KNOTS. WED
THROUGH SAT...WINDS WILL BE UNDER 20KT AS SFC HIGH PRES REMAINS IN
CONTROL THROUGH MUCH OF THE PERIOD. A WEAK FRONT IS EXPECTED TO SAG
INTO THE REGION BY SUNDAY BUT WINDS WILL REMAIN GENERALLY LIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
330 PM EDT TUE MAY 19 2015
LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE
.SYNOPSIS...
ISSUED AT 330 PM EDT TUE MAY 19 2015
A COOL AIR MASS HAS SETTLED INTO SOUTHWEST LOWER MICHIGAN AND FROST
AND FREEZING TEMPERATURES ARE A DISTINCT POSSIBILITY TONIGHT. A
FREEZE WARNING HAS BEEN POSTED FOR CENTRAL LOWER MICHIGAN AND A
FROST ADVISORY HAS BEEN HOISTED FOR THE REMAINING AREAS OF SOUTHWEST
LOWER MICHIGAN. DRY WEATHER IS EXPECTED THE REMAINDER OF THE WORK
WEEK. CONDITIONS WILL REMAIN ON THE COOL SIDE OF NORMAL THIS
WEEK...WITH A WARMUP AS WE MOVE THROUGH THE HOLIDAY WEEKEND. ALONG
WITH THE WARMER AIR WILL COME CHANCES FOR RAIN...ESPECIALLY SUNDAY
INTO MEMORIAL DAY.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 330 PM EDT TUE MAY 19 2015
MAIN FOCUS OF THE SHORT TERM WAS ON WHETHER TO EXPAND A FROST
HEADLINE INTO THE COUNTIES THAT WERE NOT COVERED BY THE FREEZE
WARNING ACROSS CENTRAL LOWER. DECIDED TO DO THAT...SO A FROST
ADVISORY IS NOW IN PLACE FOR THE REST OF THE FORECAST
AREA...ESSENTIALLY FROM INTERSTATE 96 TO THE SOUTH. DRIER AIR
CONTINUES TO POUR INTO THE AREA ON NORTHWEST WINDS...WITH THE DEW
POINT CURRENTLY AT GRAND RAPIDS AT 31 DEGREES. THINKING THE
STRATOCUMULUS WILL FADE WITH THE SETTING SUN THIS EVENING WHICH
SHOULD SET UP OK RADIATIONAL CONDITIONS. ONE ITEM OF CONCERN IS A
CORE OF WIND THAT IS SEEN IN NAM CROSS SECTIONS IN BUFKIT.
STILL...GIVEN A DECENT AMOUNT OF MAINLY CLEAR SKIES TONIGHT AND VERY
DRY/COOL AIR ALREADY IN PLACE FELT HEADLINES WERE WARRANTED ACROSS
THE FORECAST AREA.
THE REMAINDER OF THE SHORT TERM WILL BE QUIET. WE HAVE A DRY
FORECAST IN PLACE TONIGHT THROUGH THURSDAY NIGHT. THERE IS A
SHORTWAVE THAT SLIDES BY THE SOUTHERN GREAT LAKES TOMORROW NIGHT
INTO THURSDAY...BUT HAVE SIDED WITH THE DRY ECMWF AND GFS MODELS.
THE PRECIP SHOULD MISS US JUST TO THE SOUTH. ALSO ON THURSDAY...A
WEAK TROUGH MOVES THROUGH THE LOWER PENINSULA WITH SOME SPOTTY
PRECIP AMOUNTS BEING KICKED OUT BY THE MODELS. MOISTURE IS NOT ALL
THAT DEEP IN THE WED NIGHT THROUGH THURS NIGHT TIME FRAME SO AM
OPTING FOR DRY.
IT WILL BE COOL THE NEXT SEVERAL DAYS WITH NO MAJOR WARM ADVECTION
PUSH AT 850MB/S.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 330 PM EDT TUE MAY 19 2015
THE MAIN FOCUS IN THE LONG TERM WILL BE THE POSSIBILITY FOR WET
WEATHER AND GUSTY WINDS GOING INTO THE HOLIDAY WEEKEND.
HIGH PRESSURE WILL BE IN CONTROL EARLY IN THE PERIOD FROM FRIDAY
THROUGH THE MAJORITY OF SATURDAY. AS HIGH PRESSURE PROGRESSES TO THE
EAST AN AREA OF LOW PRESSURE WILL BEGIN TO EJECT OUT OF THE
SOUTHWEST AND INTO THE CENTRAL PLAINS. A WARM FRONTAL BOUNDARY WILL
EXTEND OUT AHEAD OF THE SYSTEM...GIVING WAY TO SOUTHERLY INFLUENCE.
THIS SYSTEM WILL TAKE SOMEWHAT OF A SIMILAR TRACK TO LAST WEEKENDS
SYSTEM...THROUGH THE UPPER MIDWEST.
THE BEST PRECIPITATION CHANCES WILL LIKELY BE LATE SATURDAY NIGHT
INTO SUNDAY MORNING AND AGAIN MONDAY AFTERNOON AND EVENING. SATURDAY
NIGHTS RAINFALL WILL BE ASSOCIATED WITH THE RESULTING ISENTROPIC
LIFT WITH THE PASSAGE OF THE WARM FRONT. LOW PRESSURE THEN
TRANSITIONS FROM A CLOSED LOW TO A SHORT WAVE THAT IS EVENTUALLY
CONSUMED AROUND THE MAIN CYCLONIC FLOW NEAR THE HUDSON BAY. THE WARM
FRONTAL BOUNDARY GETS HINGED UP OVER CENTRAL AND NORTHERN LOWER
MICHIGAN AND BECOMES NEARLY STATIONARY. WE MAY VERY WELL SEE A LULL
IN ACTIVITY SUNDAY AFTERNOON AS WE LOSE THE LIFT.
GOING INTO MEMORIAL DAY IS WHERE WE SEE THE POSSIBILITY OF GUSTY
WINDS AND THE POTENTIAL FOR THUNDERSTORMS. WHILE UPPER LEVEL WINDS
ARE NOT SO IMPRESSIVE...AN 850MB JET CORE OF 40-50KTS MOVES OVER THE
SOUTHERN PORTIONS OF THE FORECAST AREA. THIS IS SOMETHING THAT WOULD
USUALLY TRIGGER SOME CONCERN...BUT THERE ARE A COUPLE OF LIMITING
FACTORS TO ANY REAL ORGANIZED CONVECTION. THE BEST LIFT WOULD REMAIN
NORTH ALONG THE BOUNDARY...WHILE THE BEST CAPE STAYS SOUTHEAST OF
GRAND RAPIDS. THIS MAY BE SOMETHING TO WATCH AS WE CREEP CLOSER TO
MONDAY IF CONDITIONS BECOME BETTER ORGANIZED. OTHERWISE...IT SEEMS
THE HOLIDAY WILL HAVE SCATTERED AFTERNOON THUNDERSTORMS...SOME
LOCALIZED HEAVY RAINFALL AND GUSTY WINDS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 219 PM EDT TUE MAY 19 2015
DRIER AIR WILL CONTINUE TO WORK INTO THE REGION OVER THE NEXT
SEVERAL HOURS. MVFR CONDITIONS WILL GRADUALLY IMPROVE WITH VFR
CONDITIONS EXPECTED AREA WIDE. GUSTY WINDS SHOULD CALM THROUGH
LATE THIS EVENING AND OVERNIGHT TONIGHT. CLEAR SKIES WILL SETTLE
ALSO SETTLE IN. HIGH LEVEL SCATTERED/BROKEN CLOUDS MAY FILTER IN
NEAR DAWN ON WEDNESDAY WITH WINDS REMAINING AROUND OR BELOW 5KTS.
NO REAL IMPACTS ARE EXPECTED THROUGH 18Z WEDNESDAY WITH VFR
CONDITIONS EXPECTED.
&&
.MARINE...
ISSUED AT 330 PM EDT TUE MAY 19 2015
EXTENDED THE SMALL CRAFT ADVISORY THROUGH 800 PM. OBS ARE STILL GUST
TO AROUND 20 KNOTS IN MOST AREAS. THE BUOYS AT LAST CHECK ARE IN THE
3 TO 5 FOOT RANGE AT MUSKEGON...PORT SHELDON AND SOUTH HAVEN IN
TERMS OF WAVE HEIGHTS. EXPECTING THINGS TO DIMINISH TONIGHT. ONE
POSSIBLE ISSUE IS HIGH RESOLUTION GUIDANCE LIKE THE HRRR IS SHOWING
A SURGE IN WINDS FROM HOLLAND SOUTH AFTER DARK. THIS IS LIKELY DUE
TO SOME CHANNELING AND FUNNELING DOWN THE SHORELINE IN NORTHERLY
FLOW. THE EVENING SHIFT WILL BE MONITORING THE LATEST TRENDS IN THE
HIGH RESO GUIDANCE FOR A POSSIBLE EXTENTION IN TIME SOUTH OF
HOLLAND. THE SOUTH HAVEN GLERL OB ON THE PIER AND THE BUOY JUST
OFFSHORE WILL BE THE PIECES OF DATA TO WATCH AFTER DARK TO SEE IF
THE HRRR VERIFIES. OTHERWISE FAIRLY LIGHT WINDS THE NEXT FEW DAYS.
&&
.HYDROLOGY...
ISSUED AT 140 PM EDT MON MAY 18 2015
IN GENERAL...RIVER LEVELS ACROSS SOUTHWEST LOWER MICHIGAN ARE
GRADUALLY FALLING. THAT WILL CONTINUE TO BE THE CASE WITH LIMITED
QPF THIS WEEK. FAIR WEATHER WILL DOMINATE FOR THE REST OF THE WEEK
INTO AT LEAST SATURDAY. THE NEXT SIGNIFICANT CHANCE FOR WIDESPREAD
RAINFALL WILL BE LATE IN THE HOLIDAY WEEKEND INTO NEXT WEEK.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...FROST ADVISORY FROM MIDNIGHT TONIGHT TO 8 AM EDT WEDNESDAY FOR
MIZ050-056>059-064>067-071>074.
FREEZE WARNING FROM MIDNIGHT TONIGHT TO 8 AM EDT WEDNESDAY FOR
MIZ037>040-043>046-051-052.
LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ844>849.
&&
$$
SYNOPSIS...DUKE
SHORT TERM...DUKE
LONG TERM...JAM
AVIATION...JAM
HYDROLOGY...EBW/CAS
MARINE...DUKE
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
307 PM EDT TUE MAY 19 2015
LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE
.SYNOPSIS...
ISSUED AT 307 PM EDT TUE MAY 19 2015
A COOL AIR MASS HAS SETTLED INTO SOUTHWEST LOWER MICHIGAN AND FROST
AND FREEZING TEMPERATURES ARE A DISTINCT POSSIBILITY TONIGHT. A
FREEZE WARNING HAS BEEN POSTED FOR CENTRAL LOWER MICHIGAN AND A
FROST ADVISORY HAS BEEN HOISTED FOR THE REMAINING AREAS OF SOUTHWEST
LOWER MICHIGAN. DRY WEATHER IS EXPECTED THE REMAINDER OF THE WORK
WEEK. CONDITIONS WILL REMAIN ON THE COOL SIDE OF NORMAL THIS
WEEK...WITH A WARMUP AS WE MOVE THROUGH THE HOLIDAY WEEKEND. ALONG
WITH THE WARMER AIR WILL COME CHANCES FOR RAIN...ESPECIALLY SUNDAY
INTO MEMORIAL DAY.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 307 PM EDT TUE MAY 19 2015
MAIN FOCUS OF THE SHORT TERM WAS ON WHETHER TO EXPAND A FROST
HEADLINE INTO THE COUNTIES THAT WERE NOT COVERED BY THE FREEZE
WARNING ACROSS CENTRAL LOWER. DECIDED TO DO THAT...SO A FROST
ADVISORY IS NOW IN PLACE FOR THE REST OF THE FORECAST
AREA...ESSENTIALLY FROM INTERSTATE 96 TO THE SOUTH. DRIER AIR
CONTINUES TO POUR INTO THE AREA ON NORTHWEST WINDS...WITH THE DEW
POINT CURRENTLY AT GRAND RAPIDS AT 31 DEGREES. THINKING THE
STRATOCUMULUS WILL FADE WITH THE SETTING SUN THIS EVENING WHICH
SHOULD SET UP OK RADIATIONAL CONDITIONS. ONE ITEM OF CONCERN IS A
CORE OF WIND THAT IS SEEN IN NAM CROSS SECTIONS IN BUFKIT.
STILL...GIVEN A DECENT AMOUNT OF MAINLY CLEAR SKIES TONIGHT AND VERY
DRY/COOL AIR ALREADY IN PLACE FELT HEADLINES WERE WARRANTED ACROSS
THE FORECAST AREA.
THE REMAINDER OF THE SHORT TERM WILL BE QUIET. WE HAVE A DRY
FORECAST IN PLACE TONIGHT THROUGH THURSDAY NIGHT. THERE IS A
SHORTWAVE THAT SLIDES BY THE SOUTHERN GREAT LAKES TOMORROW NIGHT
INTO THURSDAY...BUT HAVE SIDED WITH THE DRY ECMWF AND GFS MODELS.
THE PRECIP SHOULD MISS US JUST TO THE SOUTH. ALSO ON THURSDAY...A
WEAK TROUGH MOVES THROUGH THE LOWER PENINSULA WITH SOME SPOTTY
PRECIP AMOUNTS BEING KICKED OUT BY THE MODELS. MOISTURE IS NOT ALL
THAT DEEP IN THE WED NIGHT THROUGH THURS NIGHT TIME FRAME SO AM
OPTING FOR DRY.
IT WILL BE COOL THE NEXT SEVERAL DAYS WITH NO MAJOR WARM ADVECTION
PUSH AT 850MB/S.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 307 PM EDT TUE MAY 19 2015
THE MAIN FOCUS IN THE LONG TERM WILL BE THE POSSIBLITY FOR WET
WEATHER AND GUSTY WINDS GOING INTO THE HOLIDAY WEEKEND.
HIGH PRESSURE WILL BE IN CONTROL EARLY IN THE PERIOD FROM FRIDAY
THROUGH THE MAJORITY OF SATURDAY. AS HIGH PRESSURE PROGRESSES TO THE
EAST AN AREA OF LOW PRESSURE WILL BEGIN TO EJECT OUT OF THE
SOUTHWEST AND INTO THE CENTRAL PLAINS. A WARM FRONTAL BOUNDARY WILL
EXTEND OUT AHEAD OF THE SYSTEM...GIVING WAY TO SOUTHERLY INFLUENCE.
THIS SYSTEM WILL TAKE SOMEWHAT OF A SIMILAR TRACK TO LAST WEEKENDS
SYSTEM...THROUGH THE UPPER MIDWEST.
THE BEST PRECIPITION CHANCES WILL LIKELY BE LATE SATURDAY NIGHT INTO
SUNDAY MORNING AND AGAIN MONDAY AFTERNOON AND EVENING. SATURDAY
NIGHTS RAINFALL WILL BE ASSOCIATED WITH THE RESULTING ISENTROPIC
LIFT WITH THE PASSAGE OF THE WARM FRONT. LOW PRESSURE THEN
TRANSITIONS FROM A CLOSED LOW TO A SHORT WAVE THAT IS EVENTUALLY
CONSUMED AROUND THE MAIN CYCLONIC FLOW NEAR THE HUDSON BAY. THE WARM
FRONTAL BOUNDARY GETS HINGED UP OVER CENTRAL AND NORTHERN LOWER
MICHIGAN AND BECOMES NEARLY STATIONARY. WE MAY VERY WELL SEE A LULL
IN ACTIVITY SUNDAY AFTERNOON AS WE LOSE THE LIFT.
GOING INTO MEMORIAL DAY IS WHERE WE SEE THE POSSIBILITY OF GUSTY
WINDS AND THE POTENTIAL FOR THUNDERSTORMS. WHILE UPPER LEVEL WINDS
ARE NOT SO IMPRESSIVE...AN 850MB JET CORE OF 40-50KTS MOVES OVER THE
SOUTHERN PORTIONS OF THE FORECAST AREA. THIS IS SOMETHING THAT WOULD
USUALLY TRIGGER SOME CONCERN...BUT THERE ARE A COUPLE OF LIMITING
FACTORS TO ANY REAL ORGANIZED CONVECTION. THE BEST LIFT WOULD REMAIN
NORTH ALONG THE BOUNDARY...WHILE THE BEST CAPE STAYS SOUTHEAST OF
GRAND RAPIDS. THIS MAY BE SOMETHING TO WATCH AS WE CREEP CLOSER TO
MONDAY IF CONDITIONS BECOME BETTER ORGANIZED. OTHERWISE...IT SEEMS
THE HOLIDAY WILL HAVE SCATTERED AFTERNOON THUNDERSTORMS...SOME
LOCALIZED HEAVY RAINFALL AND GUSTY WINDS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 219 PM EDT TUE MAY 19 2015
DRIER AIR WILL CONTINUE TO WORK INTO THE REGION OVER THE NEXT
SEVERAL HOURS. MVFR CONDITIONS WILL GRADUALLY IMPROVE WITH VFR
CONDITIONS EXPECTED AREA WIDE. GUSTY WINDS SHOULD CALM THROUGH
LATE THIS EVENING AND OVERNIGHT TONIGHT. CLEAR SKIES WILL SETTLE
ALSO SETTLE IN. HIGH LEVEL SCATTERED/BROKEN CLOUDS MAY FILTER IN
NEAR DAWN ON WEDNESDAY WITH WINDS REMAINING AROUND OR BELOW 5KTS.
NO REAL IMPACTS ARE EXPECTED THROUGH 18Z WEDNESDAY WITH VFR
CONDITIONS EXPECTED.
&&
.MARINE...
ISSUED AT 307 PM EDT TUE MAY 19 2015
EXTENDED THE SMALL CRAFT ADVISORY THROUGH 800 PM. OBS ARE STILL GUST
TO AROUND 20 KNOTS IN MOST AREAS. THE BUOYS AT LAST CHECK ARE IN THE
3 TO 5 FOOT RANGE AT MUSKEGON...PORT SHELDON AND SOUTH HAVEN IN
TERMS OF WAVE HEIGHTS. EXPECTING THINGS TO DIMINISH TONIGHT. ONE
POSSIBLE ISSUE IS HIGH RESOLUTION GUIDANCE LIKE THE HRRR IS SHOWING
A SURGE IN WINDS FROM HOLLAND SOUTH AFTER DARK. THIS IS LIKELY DUE
TO SOME CHANNELLING AND FUNNELLING DOWN THE SHORELINE IN NORTHERLY
FLOW. THE EVENING SHIFT WILL BE MONITORING THE LATEST TRENDS IN THE
HIGH RESO GUIDANCE FOR A POSSIBLE EXTENTION IN TIME SOUTH OF
HOLLAND. THE SOUTH HAVEN GLERL OB ON THE PIER AND THE BUOY JUST
OFFSHORE WILL BE THE PIECES OF DATA TO WATCH AFTER DARK TO SEE IF
THE HRRR VERIFIES. OTHERWISE FAIRLY LIGHT WINDS THE NEXT FEW DAYS.
&&
.HYDROLOGY...
ISSUED AT 140 PM EDT MON MAY 18 2015
IN GENERAL...RIVER LEVELS ACROSS SOUTHWEST LOWER MICHIGAN ARE
GRADUALLY FALLING. THAT WILL CONTINUE TO BE THE CASE WITH LIMITED
QPF THIS WEEK. FAIR WEATHER WILL DOMINATE FOR THE REST OF THE WEEK
INTO AT LEAST SATURDAY. THE NEXT SIGNIFICANT CHANCE FOR WIDESPREAD
RAINFALL WILL BE LATE IN THE HOLIDAY WEEKEND INTO NEXT WEEK.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...FROST ADVISORY FROM MIDNIGHT TONIGHT TO 8 AM EDT WEDNESDAY FOR
MIZ050-056>059-064>067-071>074.
FREEZE WARNING FROM MIDNIGHT TONIGHT TO 8 AM EDT WEDNESDAY FOR
MIZ037>040-043>046-051-052.
LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ844>849.
&&
$$
SYNOPSIS...DUKE
SHORT TERM...DUKE
LONG TERM...JAM
AVIATION...JAM
HYDROLOGY...EBW/CAS
MARINE...DUKE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
329 PM EDT TUE MAY 19 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 506 AM EDT TUE MAY 19 2015
LATEST WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL
TROUGH FROM NE CANADA EXTENDING INTO THE UPPER GREAT LAKES WITH THE
WEAKENING REMANTS OF THE MID-LVL LOW CIRCULATION CENTER SW OF JAMES
BAY. AT THE SFC...A TROUGH EXTENDED ACROSS THE UPPER GREAT LAKES
FROM LOW PRES NOW OVER QUEBEC. WRAPAROUND MOISTURE FROM THE LOW
CIRCULATION STILL SUSTAINING SNOW SHOWERS MIXED WITH RAIN SHOWERS
ACROSS PORTIONS OF NRN UPPER MI EARLY THIS MORNING AS NOTED ON THE
MQT RADAR.
TODAY...SFC HIGH PRES WILL BUILD TOWARD THE AREA DURING THE DAY AS
LOW-LEVEL FLOW BECOMES INCREASINGLY ANTICYCLONIC. THE ASSOCIATED
DRYING AS THE DEEPER MOISTURE DEPARTS TO THE EAST WILL ALLOW ANY
LINGERING SNOW SHOWERS TO GRADUALLY DIMINISH THIS MORNING FROM WEST
TO EAST AND END OVER MOST OF THE CWA BY 18Z. ONLY A DUSTING TO MAYBE
HALF AN INCH OF SNOW ACCUMULATION IS POSSIBLE ON GRASSY AREAS OF
NORTH CENTRAL HIGHER TERRAIN LOCATIONS BEFORE SNOW ENDS THIS
MORNING. CLOUDS WILL SLOWLY DISSIPATE FROM WEST TO EAST MAINLY
DURING THE MID TO LATE AFTERNOON WITH HIGHER PRESSURE AND ASSOC
DRIER AIR WORKING IN FM WEST. OTHERWISE...UNSEASONABLY COLD
CONDITIONS ARE EXPECTED UNDER GUSTY NW WINDS (20 TO 25 MPH
ESPECIALLY EAST HALF) AS HIGHS WILL RANGE FROM UPPER 30S/LOWER 40S
NORTH AND EAST TO THE MID AND UPPER 40S SOUTH AND WEST.
TONIGHT...HIGH PRESSURE BUILDS INTO THE AREA TONIGHT. THE DRY AIR
ASSOCIATED WITH THE HIGH WILL DIMINISH ANY LINGERING CLOUDS OVER THE
EASTERN CWA QUICKLY DURING THE EARLY EVENING HOURS. THE CLEARING
SKIES AND WEAKENING WINDS WILL LEAD TO A COLD NIGHT ACROSS THE AREA.
HAVE FOLLOWED THE LOWER END OF MODEL GUIDANCE (GIVEN PWAT VALUES AT
OR BELOW 0.25IN ACROSS MUCH OF THE INTERIOR)...WHICH INDICATES
VALUES IN THE 20S FOR MOST INTERIOR LOCATIONS...COLDEST INTERIOR
WEST ALONG THE WI BORDER WHERE LOWS COULD DIP INTO THE LOWER TO MID
20S. ALTHOUGH OUR FROST/FREEZE PROGRAM HASN/T STARTED YET...WOULD
EXPECT A WIDESPREAD FROST ACROSS UPPER MICHIGAN AND A HARD FREEZE
OVER THE INTERIOR WEST. PERSONS WITH SENSITIVE PLANTS SHOULD TAKE
THE NECESSARY PRECAUTIONS TO PROTECT AGAINST A HARD FROST AND/OR
FREEZE AND WILL INCLUDE A MENTION OF THIS IN THE HWO STATEMENT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 328 PM EDT TUE MAY 19 2015
A QUIET FIRST HALF OF THE LONG TERM PERIOD IS IN STORE FOR THE UPPER
GREAT LAKES REGION...DUE TO THE AREA BEING BETWEEN AN UPPER TROUGH
OVER EASTERN CANADA AND ANOTHER OVER THE SOUTHWESTERN
CONUS. WHILE THE UPPER GREAT LAKES REGION WILL BE BRUSHED BY A FEW
WAVES ASSOCIATED WITH THESE FEATURES...THE OVERALL FLOW WILL BE OUT
OF THE NORTHWEST OR WEST-NORTHWEST WITH LIMITED MOISTURE.
HIGH PRESSURE WILL DOMINATE MUCH OF THE WEDNESDAY TO SATURDAY
PERIOD...WITH TEMPERATURES GENERALLY RUNNING BELOW NORMAL
(ESPECIALLY NEAR LAKE SUPERIOR). THE ONLY SIGNIFICANT ITEM OF NOTE
IS A COLD FRONT THAT WILL DROP SOUTH ACROSS THE REGION ON WEDNESDAY
NIGHT AND THURSDAY. WITH MOISTURE CONTINUING TO LOOK LIMITED...WILL
JUST SHOW PARTLY CLOUDY SKIES AS IT MOVES THROUGH THE AREA. THERE
ARE SOME HINTS THAT DIURNAL HEATING MAY BE ENOUGH TO KICK OFF A
STRAY SHOWER OVER SOUTHERN MENOMINEE COUNTY (MORE LIKELY IN
NORTHEAST WISCONSIN) WITH SOME HELP FROM A LAKE BREEZE OFF THE BAY
OF GREEN BAY. DON/T HAVE ENOUGH CONFIDENCE TO INCLUDE POPS FOR
ANY FARTHER NORTH THAN THE CITY OF MENOMINEE...BUT IT WILL BE
SOMETHING TO WATCH. ANOTHER BRIEF COOL DOWN IS EXPECTED BEHIND THE
FRONT WITH THE NORTHERLY FLOW OFF LAKE SUPERIOR BEFORE HIGHS SLOWLY
RISE TOWARDS MORE NORMAL VALUES ON SATURDAY (DUE TO THE HIGH
DEPARTING AND SOUTHERLY FLOW STARTING TO DEVELOP.
MODELS REMAIN CONSISTENT ON ENERGY FROM THE SOUTHWESTERN CONUS
TROUGH EJECTING NORTHEAST TOWARDS THE AREA SATURDAY NIGHT INTO
EARLY NEXT WEEK. A SURFACE LOW DEVELOPING IN THE PLAINS WITH THIS
FEATURE WILL MOVE INTO IOWA BY SUNDAY NIGHT BEFORE LIFTING
NORTHEAST THROUGH THE GREAT LAKES REGION MONDAY INTO MONDAY NIGHT.
THE LATEST TREND IS FOR THE LOW AND ASSOCIATED UPPER LEVEL WAVE TO
LIFT FARTHER TO THE NORTH THAN THOUGHT YESTERDAY...SO WILL TREND
POPS UP ON SUNDAY NIGHT AND MONDAY AS THE LOW MOVES THROUGH.
INSTABILITY AND MID LEVEL LAPSE RATES REMAIN WEAK DURING THAT
PERIOD...WITH THE AREA GENERALLY ON THE NORTHWEST SIDE OF THE
SURFACE LOW...SO WILL KEEP THUNDER OUT OF THE FORECAST. NEXT WEEK
STILL LOOKS TO BE UNSETTLED...AS THE UPPER TROUGH IN THE SOUTHWEST
CONUS WEAKENS AND LIFTS THROUGH THE CENTRAL CONUS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 128 PM EDT TUE MAY 19 2015
AS HIGH PRESSURE BUILDS TOWARD THE AREA...EXPECT VFR CONDITIONS WITH
MUCH DRIER AIR AND MIXING AT KIWD AND INTO KCMX AND KSAW MID TO LATE
AFTERNOON AS NNW GRADUALLY DIMINISH.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 506 AM EDT TUE MAY 19 2015
LOW PRES CENTERED OVER QUEBEC WILL CONTINUE TO LIFT NE TODAY AS HIGH
PRES GRADUALLY BUILDS IN FM THE WEST. NNW WINDS TO 20 TO 30 KNOTS
(HIGHEST EAST HALF) THIS MORNING WILL DIMINISH W TO E THIS
AFTERNOON/TONIGHT AS THE HIGH BUILDS IN FM THE WEST DECREASING THE
PRES GRADIENT. WED THRROUGH SAT...WINDS WILL BE UNDER 20KT AS SFC
HIGH PRES REMAINS IN CONTROL THROUGH MUCH OF THE PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...SRF
AVIATION...JLB
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
132 PM EDT TUE MAY 19 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 506 AM EDT TUE MAY 19 2015
LATEST WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL
TROUGH FROM NE CANADA EXTENDING INTO THE UPPER GREAT LAKES WITH THE
WEAKENING REMANTS OF THE MID-LVL LOW CIRCULATION CENTER SW OF JAMES
BAY. AT THE SFC...A TROUGH EXTENDED ACROSS THE UPPER GREAT LAKES
FROM LOW PRES NOW OVER QUEBEC. WRAPAROUND MOISTURE FROM THE LOW
CIRCULATION STILL SUSTAINING SNOW SHOWERS MIXED WITH RAIN SHOWERS
ACROSS PORTIONS OF NRN UPPER MI EARLY THIS MORNING AS NOTED ON THE
MQT RADAR.
TODAY...SFC HIGH PRES WILL BUILD TOWARD THE AREA DURING THE DAY AS
LOW-LEVEL FLOW BECOMES INCREASINGLY ANTICYCLONIC. THE ASSOCIATED
DRYING AS THE DEEPER MOISTURE DEPARTS TO THE EAST WILL ALLOW ANY
LINGERING SNOW SHOWERS TO GRADUALLY DIMINISH THIS MORNING FROM WEST
TO EAST AND END OVER MOST OF THE CWA BY 18Z. ONLY A DUSTING TO MAYBE
HALF AN INCH OF SNOW ACCUMULATION IS POSSIBLE ON GRASSY AREAS OF
NORTH CENTRAL HIGHER TERRAIN LOCATIONS BEFORE SNOW ENDS THIS
MORNING. CLOUDS WILL SLOWLY DISSIPATE FROM WEST TO EAST MAINLY
DURING THE MID TO LATE AFTERNOON WITH HIGHER PRESSURE AND ASSOC
DRIER AIR WORKING IN FM WEST. OTHERWISE...UNSEASONABLY COLD
CONDITIONS ARE EXPECTED UNDER GUSTY NW WINDS (20 TO 25 MPH
ESPECIALLY EAST HALF) AS HIGHS WILL RANGE FROM UPPER 30S/LOWER 40S
NORTH AND EAST TO THE MID AND UPPER 40S SOUTH AND WEST.
TONIGHT...HIGH PRESSURE BUILDS INTO THE AREA TONIGHT. THE DRY AIR
ASSOCIATED WITH THE HIGH WILL DIMINISH ANY LINGERING CLOUDS OVER THE
EASTERN CWA QUICKLY DURING THE EARLY EVENING HOURS. THE CLEARING
SKIES AND WEAKENING WINDS WILL LEAD TO A COLD NIGHT ACROSS THE AREA.
HAVE FOLLOWED THE LOWER END OF MODEL GUIDANCE (GIVEN PWAT VALUES AT
OR BELOW 0.25IN ACROSS MUCH OF THE INTERIOR)...WHICH INDICATES
VALUES IN THE 20S FOR MOST INTERIOR LOCATIONS...COLDEST INTERIOR
WEST ALONG THE WI BORDER WHERE LOWS COULD DIP INTO THE LOWER TO MID
20S. ALTHOUGH OUR FROST/FREEZE PROGRAM HASN/T STARTED YET...WOULD
EXPECT A WIDESPREAD FROST ACROSS UPPER MICHIGAN AND A HARD FREEZE
OVER THE INTERIOR WEST. PERSONS WITH SENSITIVE PLANTS SHOULD TAKE
THE NECESSARY PRECAUTIONS TO PROTECT AGAINST A HARD FROST AND/OR
FREEZE AND WILL INCLUDE A MENTION OF THIS IN THE HWO STATEMENT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 238 AM EDT TUE MAY 19 2015
FROM WEDNESDAY THROUGH THE END OF THE WORK WEEK...A 500MB TROUGH
WILL REMAIN ACROSS THE GREAT LAKES REGION. THE LOW ITSELF WILL GET
AS CLOSE AS JAMES BAY THURSDAY AFTERNOON. AT THE SFC MUCH OF THIS
TIME PERIOD WILL BE MARKED BY A RIDGE OF HIGH PRESSURE EXTENDING
EITHER S CENTRAL CANADA OR THE NORTHERN TO CENTRAL PLAINS. LOOK FOR
THE RIDGE TO BE SUPPRESSED WEDNESDAY AFTERNOON INTO THURSDAY. A W-E
ORIENTED COLD FRONT SET UP JUST N OF LAKE SUPERIOR ACROSS ONTARIO
WILL SINK ACROSS LAKE SUPERIOR WEDNESDAY AFTERNOON...AND UPPER MI
WEDNESDAY NIGHT BEFORE PUSHING ACROSS WI AND LOWER MI DURING THE DAY
THURSDAY.
WEDNESDAY WILL BE DRY...AND EVEN WITH GOOD MIXING WINDS SHOULD STAY
FAIRLY LIGHT AS YOU NEED TO GO ABOVE 500MB TO GET ANYTHING ABOVE
15KTS. THE COLD FRONT SINKING THROUGH WILL BRING SOME MOISTURE TO
THE AREA...BUT IT/S NOT LOOKING LIKE MUCH MORE THAN CLOUD COVER.
MOST MODELS DO SHOW A BETTER CHANCE FOR AT LEAST SPRINKLES JUST S OF
MENOMINEE AND LOWER MI THURSDAY AFTERNOON...BUT NOTHING FOR UPPER
MI. THIS IS HANDLES WELL IN OUR PREVIOUS FCST...SO LIMITED CHANGES
WILL BE NEEDED. ANY REAL WARM UP WILL HAVE TO WAIT UNTIL THE
WEEKEND...AS COOL N WINDS OFF LAKE SUPERIOR AND 850MB TEMPS ON
THURSDAY HOVERING AROUND 2C. 850MB TEMPS MAY GET DOWN TO -3 OR -4C E
BY 12Z FRIDAY...LEADING TO ANOTHER CHILLY MORNING. OVERNIGHT LOWS IN
THE 30S WILL BE COMMON BOTH WEDNESDAY NIGHT AND THURSDAY NIGHT.
SATURDAY WILL BE A TRANSITION DAY AS THE CANADIAN HIGH EDGES TO THE
SE AND SLIGHTLY WARMER AIR MOVES IN. IT WILL END UP BEING THE
WARMEST DAY THIS WEEK WITH HIGHS NEAR NORMAL /60S TO AROUND 70F/.
THE 500MB RIDGE WILL STRENGTHEN OVER THE CWA SUNDAY AND MONDAY AS
THE SFC RIDGE LINGERS. THE GFS IS A BIT MORE AGGRESSIVE WITH THE MAIN
500MB TROUGH DIGGING BACK INTO THE UPPER GREAT LAKES ON
MONDAY...LEADING TO A STRONGER SYSTEM OVERALL. THE APEX OF THE RIDGE
WILL BE NEARBY AROUND 12Z MONDAY...WITH SW FLOW RETURNING AHEAD OF A
SFC LOW NEARING FROM THE SW. THE BEST CHANCE OF PRECIP IN THIS
LONGER TERM PERIOD WILL LIKELY HOLD OFF UNTIL THE DAYTIME HOURS
MONDAY. THERE IS STILL SOME UNCERTAINTY AS TO WHETHER THE BEST
CHANCE WILL BE OVER THE N OR S...DEPENDING ON THE TRACK/STRENGTH OF
THE SFC LOW AND NEARING SHORTWAVE ENERGY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 128 PM EDT TUE MAY 19 2015
AS HIGH PRESSURE BUILDS TOWARD THE AREA...EXPECT VFR CONDITIONS WITH
MUCH DRIER AIR AND MIXING AT KIWD AND INTO KCMX AND KSAW MID TO LATE
AFTERNOON AS NNW GRADUALLY DIMINISH.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 506 AM EDT TUE MAY 19 2015
LOW PRES CENTERED OVER QUEBEC WILL CONTINUE TO LIFT NE TODAY AS HIGH
PRES GRADUALLY BUILDS IN FM THE WEST. NNW WINDS TO 20 TO 30 KNOTS
(HIGHEST EAST HALF) THIS MORNING WILL DIMINISH W TO E THIS
AFTERNOON/TONIGHT AS THE HIGH BUILDS IN FM THE WEST DECREASING THE
PRES GRADIENT. WED THRROUGH SAT...WINDS WILL BE UNDER 20KT AS SFC
HIGH PRES REMAINS IN CONTROL THROUGH MUCH OF THE PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...KF
AVIATION...- NONE -
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
734 AM EDT TUE MAY 19 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 506 AM EDT TUE MAY 19 2015
LATEST WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL
TROUGH FROM NE CANADA EXTENDING INTO THE UPPER GREAT LAKES WITH THE
WEAKENING REMANTS OF THE MID-LVL LOW CIRCULATION CENTER SW OF JAMES
BAY. AT THE SFC...A TROUGH EXTENDED ACROSS THE UPPER GREAT LAKES
FROM LOW PRES NOW OVER QUEBEC. WRAPAROUND MOISTURE FROM THE LOW
CIRCULATION STILL SUSTAINING SNOW SHOWERS MIXED WITH RAIN SHOWERS
ACROSS PORTIONS OF NRN UPPER MI EARLY THIS MORNING AS NOTED ON THE
MQT RADAR.
TODAY...SFC HIGH PRES WILL BUILD TOWARD THE AREA DURING THE DAY AS
LOW-LEVEL FLOW BECOMES INCREASINGLY ANTICYCLONIC. THE ASSOCIATED
DRYING AS THE DEEPER MOISTURE DEPARTS TO THE EAST WILL ALLOW ANY
LINGERING SNOW SHOWERS TO GRADUALLY DIMINISH THIS MORNING FROM WEST
TO EAST AND END OVER MOST OF THE CWA BY 18Z. ONLY A DUSTING TO MAYBE
HALF AN INCH OF SNOW ACCUMULATION IS POSSIBLE ON GRASSY AREAS OF
NORTH CENTRAL HIGHER TERRAIN LOCATIONS BEFORE SNOW ENDS THIS
MORNING. CLOUDS WILL SLOWLY DISSIPATE FROM WEST TO EAST MAINLY
DURING THE MID TO LATE AFTERNOON WITH HIGHER PRESSURE AND ASSOC
DRIER AIR WORKING IN FM WEST. OTHERWISE...UNSEASONABLY COLD
CONDITIONS ARE EXPECTED UNDER GUSTY NW WINDS (20 TO 25 MPH
ESPECIALLY EAST HALF) AS HIGHS WILL RANGE FROM UPPER 30S/LOWER 40S
NORTH AND EAST TO THE MID AND UPPER 40S SOUTH AND WEST.
TONIGHT...HIGH PRESSURE BUILDS INTO THE AREA TONIGHT. THE DRY AIR
ASSOCIATED WITH THE HIGH WILL DIMINISH ANY LINGERING CLOUDS OVER THE
EASTERN CWA QUICKLY DURING THE EARLY EVENING HOURS. THE CLEARING
SKIES AND WEAKENING WINDS WILL LEAD TO A COLD NIGHT ACROSS THE AREA.
HAVE FOLLOWED THE LOWER END OF MODEL GUIDANCE (GIVEN PWAT VALUES AT
OR BELOW 0.25IN ACROSS MUCH OF THE INTERIOR)...WHICH INDICATES
VALUES IN THE 20S FOR MOST INTERIOR LOCATIONS...COLDEST INTERIOR
WEST ALONG THE WI BORDER WHERE LOWS COULD DIP INTO THE LOWER TO MID
20S. ALTHOUGH OUR FROST/FREEZE PROGRAM HASN/T STARTED YET...WOULD
EXPECT A WIDESPREAD FROST ACROSS UPPER MICHIGAN AND A HARD FREEZE
OVER THE INTERIOR WEST. PERSONS WITH SENSITIVE PLANTS SHOULD TAKE
THE NECESSARY PRECAUTIONS TO PROTECT AGAINST A HARD FROST AND/OR
FREEZE AND WILL INCLUDE A MENTION OF THIS IN THE HWO STATEMENT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 238 AM EDT TUE MAY 19 2015
FROM WEDNESDAY THROUGH THE END OF THE WORK WEEK...A 500MB TROUGH
WILL REMAIN ACROSS THE GREAT LAKES REGION. THE LOW ITSELF WILL GET
AS CLOSE AS JAMES BAY THURSDAY AFTERNOON. AT THE SFC MUCH OF THIS
TIME PERIOD WILL BE MARKED BY A RIDGE OF HIGH PRESSURE EXTENDING
EITHER S CENTRAL CANADA OR THE NORTHERN TO CENTRAL PLAINS. LOOK FOR
THE RIDGE TO BE SUPPRESSED WEDNESDAY AFTERNOON INTO THURSDAY. A W-E
ORIENTED COLD FRONT SET UP JUST N OF LAKE SUPERIOR ACROSS ONTARIO
WILL SINK ACROSS LAKE SUPERIOR WEDNESDAY AFTERNOON...AND UPPER MI
WEDNESDAY NIGHT BEFORE PUSHING ACROSS WI AND LOWER MI DURING THE DAY
THURSDAY.
WEDNESDAY WILL BE DRY...AND EVEN WITH GOOD MIXING WINDS SHOULD STAY
FAIRLY LIGHT AS YOU NEED TO GO ABOVE 500MB TO GET ANYTHING ABOVE
15KTS. THE COLD FRONT SINKING THROUGH WILL BRING SOME MOISTURE TO
THE AREA...BUT IT/S NOT LOOKING LIKE MUCH MORE THAN CLOUD COVER.
MOST MODELS DO SHOW A BETTER CHANCE FOR AT LEAST SPRINKLES JUST S OF
MENOMINEE AND LOWER MI THURSDAY AFTERNOON...BUT NOTHING FOR UPPER
MI. THIS IS HANDLES WELL IN OUR PREVIOUS FCST...SO LIMITED CHANGES
WILL BE NEEDED. ANY REAL WARM UP WILL HAVE TO WAIT UNTIL THE
WEEKEND...AS COOL N WINDS OFF LAKE SUPERIOR AND 850MB TEMPS ON
THURSDAY HOVERING AROUND 2C. 850MB TEMPS MAY GET DOWN TO -3 OR -4C E
BY 12Z FRIDAY...LEADING TO ANOTHER CHILLY MORNING. OVERNIGHT LOWS IN
THE 30S WILL BE COMMON BOTH WEDNESDAY NIGHT AND THURSDAY NIGHT.
SATURDAY WILL BE A TRANSITION DAY AS THE CANADIAN HIGH EDGES TO THE
SE AND SLIGHTLY WARMER AIR MOVES IN. IT WILL END UP BEING THE
WARMEST DAY THIS WEEK WITH HIGHS NEAR NORMAL /60S TO AROUND 70F/.
THE 500MB RIDGE WILL STRENGTHEN OVER THE CWA SUNDAY AND MONDAY AS
THE SFC RIDGE LINGERS. THE GFS IS A BIT MORE AGGRESSIVE WITH THE MAIN
500MB TROUGH DIGGING BACK INTO THE UPPER GREAT LAKES ON
MONDAY...LEADING TO A STRONGER SYSTEM OVERALL. THE APEX OF THE RIDGE
WILL BE NEARBY AROUND 12Z MONDAY...WITH SW FLOW RETURNING AHEAD OF A
SFC LOW NEARING FROM THE SW. THE BEST CHANCE OF PRECIP IN THIS
LONGER TERM PERIOD WILL LIKELY HOLD OFF UNTIL THE DAYTIME HOURS
MONDAY. THERE IS STILL SOME UNCERTAINTY AS TO WHETHER THE BEST
CHANCE WILL BE OVER THE N OR S...DEPENDING ON THE TRACK/STRENGTH OF
THE SFC LOW AND NEARING SHORTWAVE ENERGY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 728 AM EDT TUE MAY 19 2015
WRAPAROUND MOISTURE WILL CONTINUE TO AFFECT ALL SITES INTO THE
MORNING HOURS WITH MVFR TO OCCASIONAL IFR CONDITIONS IN LIGHT SNOW
SHOWERS. VFR CONDITIONS WITH MUCH DRIER AIR AND MIXING MOVE INTO
KIWD EARLY THIS AFTERNOON AND INTO KCMX AND KSAW MID TO LATE
AFTERNOON AS NNW GRADUALLY DIMINISH.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 506 AM EDT TUE MAY 19 2015
LOW PRES CENTERED OVER QUEBEC WILL CONTINUE TO LIFT NE TODAY AS HIGH
PRES GRADUALLY BUILDS IN FM THE WEST. NNW WINDS TO 20 TO 30 KNOTS
(HIGHEST EAST HALF) THIS MORNING WILL DIMINISH W TO E THIS
AFTERNOON/TONIGHT AS THE HIGH BUILDS IN FM THE WEST DECREASING THE
PRES GRADIENT. WED THRROUGH SAT...WINDS WILL BE UNDER 20KT AS SFC
HIGH PRES REMAINS IN CONTROL THROUGH MUCH OF THE PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...KF
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
506 AM EDT TUE MAY 19 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 506 AM EDT TUE MAY 19 2015
LATEST WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL
TROUGH FROM NE CANADA EXTENDING INTO THE UPPER GREAT LAKES WITH THE
WEAKENING REMANTS OF THE MID-LVL LOW CIRCULATION CENTER SW OF JAMES
BAY. AT THE SFC...A TROUGH EXTENDED ACROSS THE UPPER GREAT LAKES
FROM LOW PRES NOW OVER QUEBEC. WRAPAROUND MOISTURE FROM THE LOW
CIRCULATION STILL SUSTAINING SNOW SHOWERS MIXED WITH RAIN SHOWERS
ACROSS PORTIONS OF NRN UPPER MI EARLY THIS MORNING AS NOTED ON THE
MQT RADAR.
TODAY...SFC HIGH PRES WILL BUILD TOWARD THE AREA DURING THE DAY AS
LOW-LEVEL FLOW BECOMES INCREASINGLY ANTICYCLONIC. THE ASSOCIATED
DRYING AS THE DEEPER MOISTURE DEPARTS TO THE EAST WILL ALLOW ANY
LINGERING SNOW SHOWERS TO GRADUALLY DIMINISH THIS MORNING FROM WEST
TO EAST AND END OVER MOST OF THE CWA BY 18Z. ONLY A DUSTING TO MAYBE
HALF AN INCH OF SNOW ACCUMULATION IS POSSIBLE ON GRASSY AREAS OF
NORTH CENTRAL HIGHER TERRAIN LOCATIONS BEFORE SNOW ENDS THIS
MORNING. CLOUDS WILL SLOWLY DISSIPATE FROM WEST TO EAST MAINLY
DURING THE MID TO LATE AFTERNOON WITH HIGHER PRESSURE AND ASSOC
DRIER AIR WORKING IN FM WEST. OTHERWISE...UNSEASONABLY COLD
CONDITIONS ARE EXPECTED UNDER GUSTY NW WINDS (20 TO 25 MPH
ESPECIALLY EAST HALF) AS HIGHS WILL RANGE FROM UPPER 30S/LOWER 40S
NORTH AND EAST TO THE MID AND UPPER 40S SOUTH AND WEST.
TONIGHT...HIGH PRESSURE BUILDS INTO THE AREA TONIGHT. THE DRY AIR
ASSOCIATED WITH THE HIGH WILL DIMINISH ANY LINGERING CLOUDS OVER THE
EASTERN CWA QUICKLY DURING THE EARLY EVENING HOURS. THE CLEARING
SKIES AND WEAKENING WINDS WILL LEAD TO A COLD NIGHT ACROSS THE AREA.
HAVE FOLLOWED THE LOWER END OF MODEL GUIDANCE (GIVEN PWAT VALUES AT
OR BELOW 0.25IN ACROSS MUCH OF THE INTERIOR)...WHICH INDICATES
VALUES IN THE 20S FOR MOST INTERIOR LOCATIONS...COLDEST INTERIOR
WEST ALONG THE WI BORDER WHERE LOWS COULD DIP INTO THE LOWER TO MID
20S. ALTHOUGH OUR FROST/FREEZE PROGRAM HASN/T STARTED YET...WOULD
EXPECT A WIDESPREAD FROST ACROSS UPPER MICHIGAN AND A HARD FREEZE
OVER THE INTERIOR WEST. PERSONS WITH SENSITIVE PLANTS SHOULD TAKE
THE NECESSARY PRECAUTIONS TO PROTECT AGAINST A HARD FROST AND/OR
FREEZE AND WILL INCLUDE A MENTION OF THIS IN THE HWO STATEMENT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 238 AM EDT TUE MAY 19 2015
FROM WEDNESDAY THROUGH THE END OF THE WORK WEEK...A 500MB TROUGH
WILL REMAIN ACROSS THE GREAT LAKES REGION. THE LOW ITSELF WILL GET
AS CLOSE AS JAMES BAY THURSDAY AFTERNOON. AT THE SFC MUCH OF THIS
TIME PERIOD WILL BE MARKED BY A RIDGE OF HIGH PRESSURE EXTENDING
EITHER S CENTRAL CANADA OR THE NORTHERN TO CENTRAL PLAINS. LOOK FOR
THE RIDGE TO BE SUPPRESSED WEDNESDAY AFTERNOON INTO THURSDAY. A W-E
ORIENTED COLD FRONT SET UP JUST N OF LAKE SUPERIOR ACROSS ONTARIO
WILL SINK ACROSS LAKE SUPERIOR WEDNESDAY AFTERNOON...AND UPPER MI
WEDNESDAY NIGHT BEFORE PUSHING ACROSS WI AND LOWER MI DURING THE DAY
THURSDAY.
WEDNESDAY WILL BE DRY...AND EVEN WITH GOOD MIXING WINDS SHOULD STAY
FAIRLY LIGHT AS YOU NEED TO GO ABOVE 500MB TO GET ANYTHING ABOVE
15KTS. THE COLD FRONT SINKING THROUGH WILL BRING SOME MOISTURE TO
THE AREA...BUT IT/S NOT LOOKING LIKE MUCH MORE THAN CLOUD COVER.
MOST MODELS DO SHOW A BETTER CHANCE FOR AT LEAST SPRINKLES JUST S OF
MENOMINEE AND LOWER MI THURSDAY AFTERNOON...BUT NOTHING FOR UPPER
MI. THIS IS HANDLES WELL IN OUR PREVIOUS FCST...SO LIMITED CHANGES
WILL BE NEEDED. ANY REAL WARM UP WILL HAVE TO WAIT UNTIL THE
WEEKEND...AS COOL N WINDS OFF LAKE SUPERIOR AND 850MB TEMPS ON
THURSDAY HOVERING AROUND 2C. 850MB TEMPS MAY GET DOWN TO -3 OR -4C E
BY 12Z FRIDAY...LEADING TO ANOTHER CHILLY MORNING. OVERNIGHT LOWS IN
THE 30S WILL BE COMMON BOTH WEDNESDAY NIGHT AND THURSDAY NIGHT.
SATURDAY WILL BE A TRANSITION DAY AS THE CANADIAN HIGH EDGES TO THE
SE AND SLIGHTLY WARMER AIR MOVES IN. IT WILL END UP BEING THE
WARMEST DAY THIS WEEK WITH HIGHS NEAR NORMAL /60S TO AROUND 70F/.
THE 500MB RIDGE WILL STRENGTHEN OVER THE CWA SUNDAY AND MONDAY AS
THE SFC RIDGE LINGERS. THE GFS IS A BIT MORE AGGRESSIVE WITH THE MAIN
500MB TROUGH DIGGING BACK INTO THE UPPER GREAT LAKES ON
MONDAY...LEADING TO A STRONGER SYSTEM OVERALL. THE APEX OF THE RIDGE
WILL BE NEARBY AROUND 12Z MONDAY...WITH SW FLOW RETURNING AHEAD OF A
SFC LOW NEARING FROM THE SW. THE BEST CHANCE OF PRECIP IN THIS
LONGER TERM PERIOD WILL LIKELY HOLD OFF UNTIL THE DAYTIME HOURS
MONDAY. THERE IS STILL SOME UNCERTAINTY AS TO WHETHER THE BEST
CHANCE WILL BE OVER THE N OR S...DEPENDING ON THE TRACK/STRENGTH OF
THE SFC LOW AND NEARING SHORTWAVE ENERGY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 122 AM EDT TUE MAY 19 2015
WRAPAROUND MOISTURE IN LIGHT SNOW SHOWERS WILL CONTINUE TO AFFECT
ALL SITES DURING THE EARLY MORNING HOURS WITH IFR TO MVFR CONDITIONS
EXPECTED. SITES WILL BEGIN TO IMPROVE SLIGHTLY TOWARD 12Z BUT WILL
STILL REMAIN MVFR. VFR CONDITIONS WITH MUCH DRIER AIR AND MIXING MOVE
INTO CMX AND IWD THIS AFTERNOON AND WILL TAKE UNTIL THIS EVENING TO
GET VFR AT SAW WHICH WILL STAY MVFR THROUGH THEN.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 506 AM EDT TUE MAY 19 2015
LOW PRES CENTERED OVER QUEBEC WILL CONTINUE TO LIFT NE TODAY AS HIGH
PRES GRADUALLY BUILDS IN FM THE WEST. NNW WINDS TO 20 TO 30 KNOTS
(HIGHEST EAST HALF) THIS MORNING WILL DIMINISH W TO E THIS
AFTERNOON/TONIGHT AS THE HIGH BUILDS IN FM THE WEST DECREASING THE
PRES GRADIENT. WED THRROUGH SAT...WINDS WILL BE UNDER 20KT AS SFC
HIGH PRES REMAINS IN CONTROL THROUGH MUCH OF THE PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...KF
AVIATION...07
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
239 AM EDT TUE MAY 19 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 359 PM EDT MON MAY 18 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
NW ONTARIO INTO THE WRN GREAT LAKES WITH THE LOW CIRCULATION CENTER
NEAR CYQT. AT THE SFC...A TROUGH EXTENDED THROUGH NRN LAKE SUPERIOR
FROM LOW PRES E OF LAKE SUPERIOR. WITH THE WRAP-AROUND MOISTURE/PCPN
MOVING EDGING TOWARD THE AREA...RADARS INDICATED DIURNALLY ENHANCED
SCT/NMRS -SHSN/SHRA FROM NE MN INTO NW WI. SOME LIGHT RAIN OR
DRIZZLE HAD ALSO DEVELOPED INTO UPSLOPE FLOW LOCATIONS OF NW UPPER
MI.
TONIGHT...THE COMBINATION OF DEEP MOISTURE SLIDING INTO THE AREA
BEHIND THE MID LEVEL LOW AND CAA DROPPING 850 MB TEMPS INTO THE -8C
TO -11C RANGE WILL SUPPORT SCT/NMRS -SHRA/-SHSN INTO MAINLY THE WEST
HALF OF UPPER MI. THE MOST FAVORABLE UPSLOPE FLOW AND LOW LEVEL CONV
WILL SHIFT TO LOCATIONS OVER THE W FAVORED BY NRLY FLOW AND INTO N
CNTRL UPPER MI LATE. LOW LEVEL THICKNESS AND WET-BULB ZERO HEIGHTS
SUGGEST ANY PCPN WILL CHANGE OVER TO MAINLY SNOW FROM WEST TO EAST
THIS EVENING. ALTHOUGH QPF AMOUNTS TO AROUND A TENTH OF AN INCH ARE
EXPECTED...WITH THE RELATIVELY WARM GROUND...ANY SNOWFALL AMOUNTS
SHOULD REMAIN AROUND A HALF INCH OR LESS...MAINLY ON GRASSY SURFACES.
TUE...AS HIGH PRES BUILDS TOWARD THE AREA WITH INCREASINGLY ACYC
LOW LEVEL FLOW...AND THE DEEPER MOISTURE DEPARTS TO THE EAST...THE
LINGERING SNOW SHOWERS SHOULD GRADUALLY DIMINISH AND END OVER MOST OF
THE CWA BY 18Z. THERE MAY BE SOME LIGHT PCPN LINGERING OVER THE EAST
DURING THE AFTERNOON. CLOUDS WILL ALSO ONLY SLOWLY DISSIPATE FROM
WEST TO EAST DURING THE MID TO LATE AFTERNOON.
OTHERWISE...UNSEASONABLY COLD CONDITIONS ARE EXPECTED WITH HIGHS
ONLY FROM AROUND 40 NORTH TO THE MID AND UPPER 40S SOUTH AND WEST.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 238 AM EDT TUE MAY 19 2015
FROM WEDNESDAY THROUGH THE END OF THE WORK WEEK...A 500MB TROUGH
WILL REMAIN ACROSS THE GREAT LAKES REGION. THE LOW ITSELF WILL GET
AS CLOSE AS JAMES BAY THURSDAY AFTERNOON. AT THE SFC MUCH OF THIS
TIME PERIOD WILL BE MARKED BY A RIDGE OF HIGH PRESSURE EXTENDING
EITHER S CENTRAL CANADA OR THE NORTHERN TO CENTRAL PLAINS. LOOK FOR
THE RIDGE TO BE SUPPRESSED WEDNESDAY AFTERNOON INTO THURSDAY. A W-E
ORIENTED COLD FRONT SET UP JUST N OF LAKE SUPERIOR ACROSS ONTARIO
WILL SINK ACROSS LAKE SUPERIOR WEDNESDAY AFTERNOON...AND UPPER MI
WEDNESDAY NIGHT BEFORE PUSHING ACROSS WI AND LOWER MI DURING THE DAY
THURSDAY.
WEDNESDAY WILL BE DRY...AND EVEN WITH GOOD MIXING WINDS SHOULD STAY
FAIRLY LIGHT AS YOU NEED TO GO ABOVE 500MB TO GET ANYTHING ABOVE
15KTS. THE COLD FRONT SINKING THROUGH WILL BRING SOME MOISTURE TO
THE AREA...BUT IT/S NOT LOOKING LIKE MUCH MORE THAN CLOUD COVER.
MOST MODELS DO SHOW A BETTER CHANCE FOR AT LEAST SPRINKLES JUST S OF
MENOMINEE AND LOWER MI THURSDAY AFTERNOON...BUT NOTHING FOR UPPER
MI. THIS IS HANDLES WELL IN OUR PREVIOUS FCST...SO LIMITED CHANGES
WILL BE NEEDED. ANY REAL WARM UP WILL HAVE TO WAIT UNTIL THE
WEEKEND...AS COOL N WINDS OFF LAKE SUPERIOR AND 850MB TEMPS ON
THURSDAY HOVERING AROUND 2C. 850MB TEMPS MAY GET DOWN TO -3 OR -4C E
BY 12Z FRIDAY...LEADING TO ANOTHER CHILLY MORNING. OVERNIGHT LOWS IN
THE 30S WILL BE COMMON BOTH WEDNESDAY NIGHT AND THURSDAY NIGHT.
SATURDAY WILL BE A TRANSITION DAY AS THE CANADIAN HIGH EDGES TO THE
SE AND SLIGHTLY WARMER AIR MOVES IN. IT WILL END UP BEING THE
WARMEST DAY THIS WEEK WITH HIGHS NEAR NORMAL /60S TO AROUND 70F/.
THE 500MB RIDGE WILL STRENGTHEN OVER THE CWA SUNDAY AND MONDAY AS
THE SFC RIDGE LINGERS. THE GFS IS A BIT MORE AGGRESSIVE WITH THE MAIN
500MB TROUGH DIGGING BACK INTO THE UPPER GREAT LAKES ON
MONDAY...LEADING TO A STRONGER SYSTEM OVERALL. THE APEX OF THE RIDGE
WILL BE NEARBY AROUND 12Z MONDAY...WITH SW FLOW RETURNING AHEAD OF A
SFC LOW NEARING FROM THE SW. THE BEST CHANCE OF PRECIP IN THIS
LONGER TERM PERIOD WILL LIKELY HOLD OFF UNTIL THE DAYTIME HOURS
MONDAY. THERE IS STILL SOME UNCERTAINTY AS TO WHETHER THE BEST
CHANCE WILL BE OVER THE N OR S...DEPENDING ON THE TRACK/STRENGTH OF
THE SFC LOW AND NEARING SHORTWAVE ENERGY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 122 AM EDT TUE MAY 19 2015
WRAPAROUND MOISTURE IN LIGHT SNOW SHOWERS WILL CONTINUE TO AFFECT
ALL SITES DURING THE EARLY MORNING HOURS WITH IFR TO MVFR CONDITIONS
EXPECTED. SITES WILL BEGIN TO IMPROVE SLIGHTLY TOWARD 12Z BUT WILL
STILL REMAIN MVFR. VFR CONDITIONS WITH MUCH DRIER AIR AND MIXING MOVE
INTO CMX AND IWD THIS AFTERNOON AND WILL TAKE UNTIL THIS EVENING TO
GET VFR AT SAW WHICH WILL STAY MVFR THROUGH THEN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 PM EDT MON MAY 18 2015
LOW PRES EAST OF LAKE SUPERIOR WILL CONTINUE TO MOVE TO THE EAST
TONIGHT. A TIGHTENING PRES GRADIENT AHEAD OF HIGH PRES BUILDING
TOWARD THE AREA FROM THE NRN PLAINS WILL BOOST NNW WINDS TO 20 TO 30
KNOTS WITH THE POTENTIAL FOR A FEW GALE FORCE GUSTS OVER THE E HALF
LATE TONIGHT AND TUE MORNING. WINDS WILL DIMINISH W TO E TUE
AFTERNOON/NIGHT THE HIGH BUILDS IN FM THE WEST. WED THRROUGH
SAT...WINDS WILL BE UNDER 20KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
131 AM EDT TUE MAY 19 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 359 PM EDT MON MAY 18 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
NW ONTARIO INTO THE WRN GREAT LAKES WITH THE LOW CIRCULATION CENTER
NEAR CYQT. AT THE SFC...A TROUGH EXTENDED THROUGH NRN LAKE SUPERIOR
FROM LOW PRES E OF LAKE SUPERIOR. WITH THE WRAP-AROUND MOISTURE/PCPN
MOVING EDGING TOWARD THE AREA...RADARS INDICATED DIURNALLY ENHANCED
SCT/NMRS -SHSN/SHRA FROM NE MN INTO NW WI. SOME LIGHT RAIN OR
DRIZZLE HAD ALSO DEVELOPED INTO UPSLOPE FLOW LOCATIONS OF NW UPPER
MI.
TONIGHT...THE COMBINATION OF DEEP MOISTURE SLIDING INTO THE AREA
BEHIND THE MID LEVEL LOW AND CAA DROPPING 850 MB TEMPS INTO THE -8C
TO -11C RANGE WILL SUPPORT SCT/NMRS -SHRA/-SHSN INTO MAINLY THE WEST
HALF OF UPPER MI. THE MOST FAVORABLE UPSLOPE FLOW AND LOW LEVEL CONV
WILL SHIFT TO LOCATIONS OVER THE W FAVORED BY NRLY FLOW AND INTO N
CNTRL UPPER MI LATE. LOW LEVEL THICKNESS AND WET-BULB ZERO HEIGHTS
SUGGEST ANY PCPN WILL CHANGE OVER TO MAINLY SNOW FROM WEST TO EAST
THIS EVENING. ALTHOUGH QPF AMOUNTS TO AROUND A TENTH OF AN INCH ARE
EXPECTED...WITH THE RELATIVELY WARM GROUND...ANY SNOWFALL AMOUNTS
SHOULD REMAIN AROUND A HALF INCH OR LESS...MAINLY ON GRASSY SURFACES.
TUE...AS HIGH PRES BUILDS TOWARD THE AREA WITH INCREASINGLY ACYC
LOW LEVEL FLOW...AND THE DEEPER MOISTURE DEPARTS TO THE EAST...THE
LINGERING SNOW SHOWERS SHOULD GRADUALLY DIMINISH AND END OVER MOST OF
THE CWA BY 18Z. THERE MAY BE SOME LIGHT PCPN LINGERING OVER THE EAST
DURING THE AFTERNOON. CLOUDS WILL ALSO ONLY SLOWLY DISSIPATE FROM
WEST TO EAST DURING THE MID TO LATE AFTERNOON.
OTHERWISE...UNSEASONABLY COLD CONDITIONS ARE EXPECTED WITH HIGHS
ONLY FROM AROUND 40 NORTH TO THE MID AND UPPER 40S SOUTH AND WEST.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 320 PM EDT MON MAY 18 2015
A GENERALLY QUIET LONG TERM PERIOD IS IN STORE FOR THE UPPER GREAT
LAKES REGION. THIS IS DUE TO THE AREA LARGELY BEING BETWEEN AN
UPPER TROUGH OVER EASTERN CANADA AND ANOTHER OVER THE SOUTHWESTERN
CONUS. WHILE THE UPPER GREAT LAKES REGION WILL BE BRUSHED BY A FEW
WAVES ASSOCIATED WITH THESE FEATURES...THE OVERALL FLOW WILL BE OUT
OF THE NORTHWEST OR WEST-NORTHWEST WITH LIMITED MOISTURE.
HIGH PRESSURE BUILDS INTO THE AREA ON TUESDAY NIGHT AND REMAINS
INTO WEDNESDAY. THE DRY AIR ASSOCIATED WITH THE HIGH WILL DIMINISH
ANY LINGERING CLOUDS OVER THE EASTERN CWA QUICKLY DURING THE EARLY
EVENING HOURS. THE CLEARING SKIES AND WEAKENING WINDS WILL LEAD TO
A COLD NIGHT ACROSS THE AREA ON TUESDAY NIGHT. HAVE FOLLOWED THE
LOWER END OF GUIDANCE (WITH PWAT VALUES ONLY AROUND 0.25IN)...WHICH
GIVES VALUES IN THE 20S FOR MOST INTERIOR LOCATIONS. ALTHOUGH OUR
FROST/FREEZE PROGRAM HASN/T STARTED...WOULD EXPECT A WIDESPREAD
FROST (AND A HARD FREEZE FOR THE INTERIOR WEST) ACROSS UPPER
MICHIGAN AND PERSONS WITH SENSITIVE PLANTS WOULD BE WISE TO PREPARE
FOR A SOLID FROST.
A WEAK COLD FRONT DROPS SOUTH FROM ONTARIO WEDNESDAY NIGHT AND WITH
THE LACK OF MOISTURE ONLY SHOWED A PERIOD OF PARTLY CLOUDY SKIES
AS IT MOVES THROUGH. BEHIND THE FRONT...NORTHERLY FLOW OFF LAKE
SUPERIOR WILL KEEP TEMPERATURES COOLER NEAR LAKE SUPERIOR ON
THURSDAY (50S) WHILE AREAS INLAND RISE TO OR JUST ABOVE 60.
FRIDAY/SATURDAY CONTINUE TO LOOK DRY (WITH TEMPERATURES WARMING
TOWARDS NORMAL) AS ANOTHER CANADIAN HIGH PRESSURE MOVES ACROSS THE
AREA.
THE HIGH WILL DEPART SATURDAY NIGHT...AS ENERGY FROM THE
SOUTHWESTERN CONUS TROUGH EJECTS NORTHEAST TOWARDS THE AREA. A
SURFACE LOW DEVELOPING IN THE PLAINS WITH THIS FEATURE WILL MOVE
INTO IOWA BY SUNDAY NIGHT BEFORE SLOWLY SHIFTING EAST THROUGH
SOUTHERN WISCONSIN BY MONDAY NIGHT. AT THIS POINT...EXPECT THE CWA
TO BE ON THE NORTHERN EDGE OF MUCH OF THE FORCING (WARM FRONT
STALLS OVER SOUTHERN WISCONSIN) AND BEST CHANCES FOR RAIN WILL BE
OVER THE SOUTHERN HALF OF THE CWA AS WEAK SHORTWAVES LIFT NORTHEAST
ACROSS THE AREA IN THE SOUTHWESTERLY FLOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 122 AM EDT TUE MAY 19 2015
WRAPAROUND MOISTURE IN LIGHT SNOW SHOWERS WILL CONTINUE TO AFFECT
ALL SITES DURING THE EARLY MORNING HOURS WITH IFR TO MVFR CONDITIONS
EXPECTED. SITES WILL BEGIN TO IMPROVE SLIGHTLY TOWARD 12Z BUT WILL
STILL REMAIN MVFR. VFR CONDITIONS WITH MUCH DRIER AIR AND MIXING MOVE
INTO CMX AND IWD THIS AFTERNOON AND WILL TAKE UNTIL THIS EVENING TO
GET VFR AT SAW WHICH WILL STAY MVFR THROUGH THEN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 PM EDT MON MAY 18 2015
LOW PRES EAST OF LAKE SUPERIOR WILL CONTINUE TO MOVE TO THE EAST
TONIGHT. A TIGHTENING PRES GRADIENT AHEAD OF HIGH PRES BUILDING
TOWARD THE AREA FROM THE NRN PLAINS WILL BOOST NNW WINDS TO 20 TO 30
KNOTS WITH THE POTENTIAL FOR A FEW GALE FORCE GUSTS OVER THE E HALF
LATE TONIGHT AND TUE MORNING. WINDS WILL DIMINISH W TO E TUE
AFTERNOON/NIGHT THE HIGH BUILDS IN FM THE WEST. WED THRROUGH
SAT...WINDS WILL BE UNDER 20KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DULUTH MN
246 AM CDT TUE MAY 19 2015
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 245 AM CDT TUE MAY 19 2015
AN UPPER TROUGH WILL REMAIN OVER THE NORTHLAND TODAY...BUT DRIER
AIR AND WEAK HIGH PRESSURE AT THE SURFACE SHOULD SCOUR OUT THE
CLOUDS THAT COVERED MOST AREAS AS OF 0730Z AND KEEP MOST AREAS DRY
TODAY. SOME LIGHT SNOW SHOWERS CONTINUED EARLY THIS MORNING UNDER
THIS DECK OF STRATOCU AND THAT WILL CONTINUE UNTIL IT CLEARS. MORE
PERSISTENT SNOW SHOWERS ARE POSSIBLE OVER THE SNOWBELT REGION OF
ASHLAND/IRON COUNTIES. A SPOTTER IN GILE REPORTED SOME LIGHT SNOW
ACCUMULATION SHORTLY AFTER 05Z AND WEBCAMS AROUND IRONWOOD ALSO
SHOW SOME LIGHT ACCUMULATION. SHIP AND BUOY OBS INDICATE THE LAKE
IS AROUND 2 TO 4C AND WITH 850MB TEMPS AROUND -10C THIS
MORNING...FAVORABLE CONDITIONS FOR SNOW SHOWERS WILL CONTINUE THIS
MORNING. THE LAKE EFFECT WILL DIMINISH BY LATE MORNING AS TEMPS
WARM AND DRIER AIR CONTINUE TO MOVES IN. WE FOLLOWED THE RAP/NAM
ON CLEARING TODAY AND WENT WITH HIGHS IN THE FIFTIES FOR MOST AREAS.
TONIGHT WILL BE MOSTLY CLEAR...WITH SOME HIGH CLOUDS MOVING IN.
THE CLOUDS SHOULD BE THIN ENOUGH AND WINDS LIGHT ENOUGH TO ALLOW
FOR COLD TEMPERATURES. MOST AREAS WILL DROP BELOW FREEZING...WITH
SOME LOCALIZED AREAS INTO THE LOWER TWENTIES.
WE EXPECT PARTLY TO MOSTLY SUNNY SKIES WEDNESDAY WITH TEMPERATURES
WARMING INTO THE LOWER TO MIDDLE SIXTIES. A WEAK COLD FRONT WILL
JUST BE NEARING THE INTERNATIONAL BORDER BY EARLY WEDNESDAY
EVENING.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 245 AM CDT TUE MAY 19 2015
QUIET PERIOD THROUGH THE END OF THE WEEK ACROSS THE FORECAST AREA.
AN AREA OF HIGH PRESSURE WILL DOMINATE THE WEATHER ACROSS THE REGION
THROUGH SATURDAY WITH MAINLY SUNNY SKIES AND SLOWLY WARMING
TEMPERATURES. MODELS SHOW A VERY WEAK FRONT WILL MOVE THROUGH THE
FORECAST REGION EARLY THURSDAY BUT ONLY CLOUDS WILL BE SEEN WITH
THIS SYSTEM. THE NORTHWEST FLOW WILL SWITCH AROUND TO A S-SW FLOW
BY FRIDAY WHICH WILL ALLOW MOISTURE TO MOVE INTO THE REGION. THE
MODELS INDICATE A LOW PRESSURE AREA TO MOVE INTO THE CENTRAL PLAINS
BY THE SATURDAY NIGHT/SUNDAY TIMEFRAME. THIS WILL BRING A CHANCE
FOR SHOWERS TO THE REGION FOR SUNDAY AND MONDAY. MODELS DO SHOW
SOME INCREASE INSTABILITY...SO WILL HAVE ISOLATED TSTMS IN THE
GRIDS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 106 AM CDT TUE MAY 19 2015
AN AREA OF LOW PRESSURE JUST NORTH OF LAKE SUPERIOR WILL CONTINUE
MOVING NORTHEASTWARDS INTO QUEBEC PROVINCE. BEHIND IT HIGH
PRESSURE WILL BUILD INTO THE NORTHLAND THROUGH TUESDAY. CIGS WILL
VARY BETWEEN VFR/MVFR AT ALL SITES UNTIL AT LEAST 09Z. LAST
SEVERAL RAP SOUNDINGS AND LATEST NAM SHOW ALL SITES EXCEPT FOR
KHYR REACH VFR CIGS BETWEEN 09Z AND 13Z. KHYR SHOULD REACH VFR CIGS
AROUND 16Z. GUSTY WINDS WILL DEVELOP AT KDLH AND KHIB AROUND
13Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 53 34 63 39 / 0 0 0 0
INL 53 26 66 36 / 0 0 0 0
BRD 55 30 65 42 / 0 0 0 0
HYR 53 27 64 38 / 10 0 0 0
ASX 53 32 62 38 / 20 0 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 7 AM CDT THIS MORNING FOR LSZ121-140-
146>148.
&&
$$
SHORT TERM...MELDE
LONG TERM...STEWART
AVIATION...STEWART/WL
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
106 AM CDT TUE MAY 19 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY AFTERNOON)
ISSUED AT 251 PM CDT MON MAY 18 2015
MAIN CONCERNS IN THE SHORT TERM ARE CENTERED AROUND THE LINGERING
RAIN AND SNOW SHOWERS ACROSS THE REGION THIS AFTERNOON AND EVENING
WITH AN INCOMING COLD AIR MASS FROM THE NORTH PRODUCING
TEMPERATURES 15 TO 20 DEGREES BELOW NORMAL TODAY...TONIGHT AND
TOMORROW.
STACKED LOW PRESSURE SYSTEM CURRENTLY LIFTING NEWD FROM THE TIP
OF THE ARROWHEAD INTO ONTARIO AND THE NRN GREAT LAKES THIS
AFTERNOON WITH A COLD CANADIAN AIR MASS FILLING IN BEHIND THE
DEPARTING SYSTEM ACROSS MUCH OF THE UPPER MIDWEST. THIS STRONG
AREA OF LOW PRESSURE WHICH BROUGHT MUCH NEEDED RAIN TO THE REGION
THIS PAST WEEKEND IS CONTINUING TO PRODUCE LIGHT RAIN SHOWERS OVER
THE AREA TODAY WITH THE COLD AIR MIXING IN ALLOWING FOR A FEW SNOW
SHOWERS AS WELL. THE COLD AND WET CONDITIONS ARE ALSO COMBINING
WITH GUSTY N/NW WINDS TODAY AS HIGH PRESSURE TO THE WEST AND THE
DEEP SYSTEM TO THE EAST INDUCE A TIGHT PRESSURE GRADIENT OVER NRN
MN. HAVE HAD REPORTS OF SUSTAINED WINDS 15 TO 20 MPH...AND GUSTS
NEAR OR EXCEEDING 30 MPH. IN CASE YOU FORGOT WHAT FALL FEELS LIKE.
PRECIPITATION TRENDS TONIGHT WILL BE DRYING AS THE SYSTEM
CONTINUES TO MOVE TO THE EAST AND HIGH PRESSURE AND DRIER AIR MOVE
IN OVER THE UPPER MIDWEST. THE GRADIENT WILL ALSO RELAX AS THE
HIGH MOVES IN...WHICH WILL ALLOW THE WINDS TO DIMINISH THROUGH THE
OVERNIGHT HOURS...BUT REMAIN LIGHT FROM THE N/NW.
THE COLD CONDITIONS WILL PERSIST TONIGHT WITH LOWS IN THE UPPER 20S
AND 30S OVER MUCH OF THE AREA. A FEW ISOLATED COLDER LOCATIONS
INTO THE LOWER TO MID 20S ARE NOT OUT OF THE QUESTION...ESPECIALLY
IF CLOUDS MIX OUT OVER N-CENTRAL MN BEFORE SUNRISE TUE MORNING.
EXPECTING WEAK LAKE INDUCED CLOUDS AND LIGHT SNOW/DRIZZLE ALONG
THE SOUTH SHORE TONIGHT AND EARLY TUE MORNING...BUT WITH ONLY
LIGHT AMTS ANTICIPATED. MOST OF THE DAY TUESDAY WILL BE SUNNY
ACROSS THE NORTHLAND...BUT WITH THE INFLUENCE FROM THE COLD AIR
MASS STILL IN PLACE ONLY ALLOWING TEMPERATURES TO REACH INTO THE
LOWER TO MID 50S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 251 PM CDT MON MAY 18 2015
IN SUMMARY...THE NORTHLAND CAN ANTICIPATE CLEAR SKIES FOR MOST OF
THE MIDDLE AND LATTER HALF OF THE WEEK WITH TEMPERATURES SLIGHTLY
ON THE COOLER SIDE OF NORMAL. THERE IS AN OPPORTUNITY FOR LIGHT
RAIN OVER THE SOUTHERN FORECAST AREA OVER THE WEEKEND.
SURFACE HIGH PRESSURE OVER THE NORTHERN PLAINS AND UPPER MIDWEST
WILL HELP KEEP THE NORTHLAND DRY AND SUNNY FOR THE MIDDLE AND
LATTER HALF OF THE WEEK. COOL NW FLOW ALOFT WILL KEEP TEMPERATURES
SLIGHTLY ON THE COOLER SIDE FOR TUESDAY NIGHT THROUGH THURSDAY
NIGHT. THE COLDEST NIGHT WILL BE TUESDAY NIGHT WITH TEMPERATURES
LIKELY FALLING INTO THE UPPER 20S AND LOW 30S EARLY WEDNESDAY.
LEANED ON THE COOLER NAM/GFS MOS GUIDANCE FOR TUESDAY NIGHT LOWS
SINCE THE CLEAR SKIES AND LIGHT WINDS WILL PROMOTE RADIATIONAL
COOLING. A WEAK COLD FRONT WILL MOVE THROUGH THE NORTHLAND LATE
WEDNESDAY AND EARLY THURSDAY...BUT AT THIS TIME...IT APPEARS THERE
WILL BE FEW CLOUDS AND NO PCPN WITH THE PASSAGE OF THIS FRONT.
THE PATTERN WILL BEGIN TO CHANGE LATE THIS WEEK. THE NW FLOW WILL
SUBSIDE FRIDAY. LIGHT SW TO W WINDS ARE LIKELY. THE GFS AND ECMWF
INCREASE 850 HPA TEMPERATURES FOR FRIDAY TO A COUPLE DEGREES MORE
THAN THURSDAY. THINK THE SUNNY SKIES AND GENERALLY WARMER AIR MASS
SHOULD FAVOR SLIGHTLY WARMER TEMPERATURES COMPARED TO
THURSDAY...SO INCREASED THE FRIDAY FORECAST A BIT. THE GFS
EXTENDED MOS CAME IN WITH A HIGH OF 68 FOR FRIDAY. AVOIDED
INCREASING THE HIGH TEMPERATURE FOR THE TWIN PORTS AREA THAT MUCH
BECAUSE THE LIGHT WIND FLOW REGIME COULD RESULT IN A SUBTLE LAKE
BREEZE.
THE GFS/GEM/ECMWF ARE INDICATING A LOW WILL MOVE INTO THE PLAINS
OVER THE WEEKEND...AND THE ASSOCIATED WARM FRONT WILL BEGIN TO LIFT
INTO THE UPPER MIDWEST. THE GFS BRINGS THE WARM FRONT...ESPECIALLY
THE ELEVATED 850 HPA WARM FRONT...FASTER AND FARTHER NORTH THAN THE
ECMWF. MAINTAINED LOW PCPN CHANCES FOR SHOWERS AND STORMS OVER THE
SOUTHERN FORECAST AREA SATURDAY THROUGH SUNDAY. EASTERLY FLOW MAY
DEVELOP SUNDAY...AND IF SO...THE COOL FLOW FROM THE LAKE COULD
SUPPRESS ANY CHANCE OF THUNDER TO WELL SOUTH OF HIGHWAY 2.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 106 AM CDT TUE MAY 19 2015
AN AREA OF LOW PRESSURE JUST NORTH OF LAKE SUPERIOR WILL CONTINUE
MOVING NORTHEASTWARDS INTO QUEBEC PROVINCE. BEHIND IT HIGH
PRESSURE WILL BUILD INTO THE NORTHLAND THROUGH TUESDAY. CIGS WILL
VARY BETWEEN VFR/MVFR AT ALL SITES UNTIL AT LEAST 09Z. LAST
SEVERAL RAP SOUNDINGS AND LATEST NAM SHOW ALL SITES EXCEPT FOR
KHYR REACH VFR CIGS BETWEEN 09Z AND 13Z. KHYR SHOULD REACH VFR CIGS
AROUND 16Z. GUSTY WINDS WILL DEVELOP AT KDLH AND KHIB AROUND
13Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 34 63 39 63 / 0 0 0 0
INL 29 66 36 64 / 0 0 0 0
BRD 34 65 42 68 / 0 0 0 0
HYR 29 64 38 66 / 0 0 0 0
ASX 32 62 38 62 / 0 0 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 7 AM CDT THIS MORNING FOR LSZ121-140-
146>148.
&&
$$
SHORT TERM...BJT
LONG TERM...GROCHOCINSKI
AVIATION...STEWART/WL
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
650 AM CDT Tue May 19 2015
.SHORT TERM: (Through Late This Afternoon)
Issued at 425 AM CDT Tue May 19 2015
High pressure building into Missouri and Illinois brings cool
temperatures and calm weather to the area today. Expect highs in
the 60s and light winds out of the northwest to north.
42
.LONG TERM: (Tonight through Monday)
Issued at 425 AM CDT Tue May 19 2015
An upper disturbance induces a surface wave along a pre-existing
baroclinic zone stretching across the south central and
southeastern states. A southerly LLJ ahead of the low pressure
system interacts with the boundary to spread showers/thunderstorms
northward into the forecast area as early as late tonight.
Precipitation coverage seems most widespread on Wednesday, then
tapers off on Wednesday night when the surface wave both dampens
and moves farther away from the forecast area. High pressure
builds back into the region on Thursday for another day of cooler
temperatures and calm weather. The synoptic pattern for this
weekend resembles the synoptic pattern for the last two weekends.
A few periods of active weather appear likely between Friday and
Monday.
42
&&
.AVIATION: (For the 12z TAFs through 12z Wednesday Morning)
Issued at 650 AM CDT Tue May 19 2015
Over the last few hours some of the cold air SC (with MVFR cigs) in
the wake of the Great Lakes low has managed to drift south and
sneak into our far N counties...including KUIN. 00z and 06z
guidance as well as the latest RUC solutions suggest that this
cloudiness should become stationary and quickly dissipate over the
next few hours. Otherwise and elsewhere...VFR conditions are
expected today, with cloudiness limited to some high level CI
spreading from the Plains into the mid-Mississippi Valley. Mid and
high clouds will then slowly thicken overnight as WAA ramps up
ahead of upper level trof. Overnight synoptic guidance suggests
that only threat of rain during this TAF period will be limited to
KCOU just before daybreak, with cigs here possibily lowering to
around 5kft by this time.
Specifics for KSTL: Clouds aoa 10kft expected today and into
tonight, with north-northeast winds aob 10kts. Ceilings should
begin to lower on Wednesday morning as WAA intensifies across
area, with ceilings dropping into the 3-5kt range by late morning
as rain begins to push into the area.
Truett
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
915 PM PDT MON MAY 18 2015
.SYNOPSIS...AN AREA OF LOW PRESSURE LIFTING AWAY TO THE NORTHERN
INTERMOUNTAIN REGION WILL LEAVE LINGERING MOISTURE FOR SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS ACROSS THE SOUTHERN GREAT BASIN
TUESDAY. MOST AREAS WILL SEE DRY CONDITIONS ON WEDNESDAY AND
WEDNESDAY NIGHT. A NEW STORM SYSTEM WILL APPROACH THE AREA ON
THURSDAY THEN MOVE ACROSS ON FRIDAY BRINGING ADDITIONAL CHANCES FOR
SHOWERS AND THUNDERSTORMS. A SLOW DRYING AND WARMING TREND IS
EXPECTED FOR THE MEMORIAL DAY WEEKEND.
&&
.UPDATE...ONLY A FEW LINGERING LIGHT SHOWERS WERE INDICATED BY RADAR
ACROSS SOUTHERN NYE COUNTY AND MOHAVE COUNTY LATE THIS EVENING AND
WHATEVER REMAINS SHOULD FADE AWAY SHORTLY. SHOWERS ARE PRETTY WELL
OVER FOR AREAS FROM LAS VEGAS SOUTHWARD. ISOLATED TO SCATTERED LIGHT
SHOWERS WILL KEEP GOING OVER NORTHERN INYO COUNTY AND THE SOUTHERN
GREAT BASIN ZONES NEAR THE UPPER LOW CENTER BUT ANY PRECIP AMOUNTS
WILL BE MINIMAL. THE POP/WX/SKY/QPF GRIDS WERE ADJUSTED BASED ON
THESE LATEST TRENDS.
&&
.PREV DISCUSSION...
339 PM PDT MON MAY 18 2015
.SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT.
CLARK AND LINCOLN COUNTIES HAVE REALLY SEEN AN ACTIVE DAY AS SHOWERS
AND THUNDERSTORMS GOT GOING SHORTLY AFTER DAYBREAK IN THE NORTHEAST
QUADRANT OF A MID/UPPER LEVEL LOW. THE CENTER OF THIS LOW COULD BE
SEEN THIS AFTERNOON ON WATER VAPOR AND SATELLITE OVER DEATH VALLEY
NATIONAL PARK. DESPITE ONLY 0.53 INCH OF PWAT IN THIS MORNING`S NWS
VEGAS SOUNDING AND RELATIVELY LOW-TOPPED CONVECTION, THERE HAVE BEEN
SOME IMPRESSIVE PRECIPITATION TOTALS TODAY WHERE STRONGER STORMS
DEVELOPED OR ACTIVITY TRAINED. A FEW SPOTS IN SUMMERLIN WEST PICKED
UP OVER AN INCH OF RAIN AS WELL AS ONE GUAGE JUST SOUTH OF INSPIRADA
IN HENDERSON. WHILE WIDESPREAD HEAVY RAIN IS NOT EXPECTED THIS
EVENING, ANY SLOWER MOVING OR STRONGER ACTIVITY COULD DUMP A HALF OF
AN INCH OR MORE OF RAIN ESPECIALLY IF IT TRAINS. GIVEN THE
ATMOSPHERE HAS BECOME WORKED OVER IN AND AROUND THE LAS VEGAS VALLEY
EARLIER TODAY, WE THINK THAT THE INTENSITY OF ACTIVITY IMMEDIATELY
IN AND AROUND THE VALLEY SHOULD STAY TOWARD THE LOW-MODERATE END.
HOWEVER, CLOSER TO THE LOW CENTER IN THE NORTHEAST QUADRANT WHERE
ACTIVITY WAS MORE LIMITED EARLIER TODAY, THINGS COULD BE MORE ACTIVE
IN ESMERALDA, EASTERN INYO AND CENTRAL NYE COUNTIES. THE HRRR AND
LOCAL NMM AND ARW MODELS ALL KEY IN ON THESE AREAS FOR ACTIVITY TO
DEVELOP OR PERSIST THIS EVENING AND THUS POPS WERE ADJUSTED UP IN
THESE AREAS. THESE AREAS MAY BE THE SLOWEST TO SEE ACTIVITY END THIS
EVENING WHILE ELSEWHERE THINGS SHOULD END BETWEEN 7 AND 9 PM. LOW
FREEZING LEVELS HAVE ALSO RESULTED IN STRONGER ACTIVITY PRODUCING
HAIL WITH REPORTS EARLIER TODAY AS LARGE AS AN INCH IN DIAMETER IN
THE MOST INTENSE ACTIVITY. IN ADDITION SNOW LEVELS AROUND 8500 FEET
WERE NOTED AND A LIGHT COATING TO AN INCH OR TWO OF SNOW IS POSSIBLE
IN THE HIGHEST ELEVATIONS UNDER ANY SHOWER OR THUNDERSTORM ACTIVITY
OVERNIGHT.
THE LOW CENTER WILL TRANSITION ACROSS THE AREA TONIGHT WHICH WILL
PLACE US ON THE BACK SIDE OF THE LOW FOR TUESDAY. LINGERING ENERGY
AND MID-LEVEL MOISTURE WILL BE ENOUGH TO TOUCH OFF SCATTERED SHOWERS
AND ISOLATED THUNDERSTORMS MAINLY ACROSS THE SOUTHERN GREAT BASIN
BUT OUTSIDE OF LINCOLN AND CENTRAL NYE COUNTIES THE COVERAGE OF
ACTIVITY SHOULD BE LOWER TOMORROW. ONCE AGAIN, LOW FREEZING LEVELS
WILL ALLOW FOR HAIL IN ANY STRONGER ACTIVITY. HIGH TEMPS SHOULD WARM
UP SEVERAL DEGREES AS DRIER AIR WORKS IN AND ERODES AWAY THE CLOUDS
OVER THE MOJAVE DESERT.
ANOTHER LOW WILL APPROACH THE COAST OF CALIFORNIA ON WEDNESDAY. THIS
WILL SPREAD LOTS OF HIGH LEVEL MOISTURE INTO THE AREA AS THE JET
STREAM PASSES BY ACROSS SOCAL INTO ARIZONA RESULTING IN A DECENT
AMOUNT OF CIRRUS CLOUDS TO START TO THE DAY AND AGAIN WEDNESDAY
NIGHT. OTHERWISE, THE BEST MOISTURE AND INSTABILITY WILL BE OVER THE
SOUTHERN SIERRA CREST AND EASTERN SLOPES AS WELL AS ESMERALDA COUNTY
AND A FEW SHOWERS AND THUNDERSTORMS ARE POSSIBLE HERE MAINLY IN THE
AFTERNOON. THE REST OF THE AREA LOOKS DRY WITH WINDS PICKING UP FROM
THE SOUTH IN THE AFTERNOON AND EVENING AND GUSTING TO 20-30 MPH.
HIGH TEMPS SHOULD WARM BACK UP ANOTHER 3-5 DEGREES OVER TUESDAY.
THIS LOW WILL EVENTUALLY LOOP BACK OUT AND MERGE WITH ANOTHER LOW
THAT HEADS TOWARD THE COAST ON THURSDAY.
.LONG TERM...THURSDAY THROUGH MONDAY.
THE NEXT UPPER LOW WILL APPROACH THE CENTRAL CALIFORNIA COAST
THURSDAY. A SHORTWAVE ROTATING AROUND THE LOW WILL MOVE NORTHEAST
INTO CALIFORNIA AND NEVADA DURING THE DAY. AN AREA OF DIFFLUENCE AND
DECENT MID LEVEL MOISTURE WILL LEAD TO A CHANCE OF SHOWERS OVER MUCH
OF INYO COUNTY AND ACROSS ESMERALDA...CENTRAL NYE AND NORTHERN
LINCOLN COUNTIES. THE UPPER LOW WILL MOVE INLAND THURSDAY NIGHT AND
ACROSS SOUTHERN NEVADA INTO NORTHWEST ARIZONA FRIDAY. PRECIPITATION
CHANCES WILL THUS SPREAD EAST ACROSS A GOOD PORTION OF THE FORECAST
AREA...MAINLY NORTH OF INTERSTATE 40. WITH THE LOW MOVING
OVERHEAD...HIGH TEMPERATURES FRIDAY WILL BE SOME 10 TO 15 DEGREES
BELOW NORMAL. PRECIPITATION CHANCES WILL DECREASE AND SHIFT
NORTHEAST FRIDAY NIGHT AS THE LOW STARTS TO EXIT THE AREA.
HOWEVER...A SHORTWAVE TROUGH FOLLOWING BEHIND FROM THE NORTH WILL
BRING A CHANCE OF SHOWERS SATURDAY TO AREAS MAINLY NORTH OF LAS
VEGAS.
FOR SUNDAY THROUGH MONDAY THE MODELS ARE NOT IN VERY GOOD AGREEMENT
BUT IN GENERAL IT LOOKS LIKE THERE WILL BE SOME SORT OF UPPER TROUGH
ROUGHLY OVER NORTHERN NEVADA. THIS WOULD KEEP AT LEAST A SLIGHT
CHANCE OF SHOWERS OVER THE FAR NORTHERN PART OF THE FORECAST AREA
AND I LEFT SLIGHT CHANCE POPS IN FOR THOSE AREAS.
&&
.AVIATION...FOR MCCARRAN...LIGHT NORTHEAST WINDS THAT DEVELOPED
EARLY THIS EVENING SHOULD GIVE WAY TO TYPICAL DIURNAL DIRECTIONS AT
8 KTS OR LESS THE REST OF TONIGHT THROUGH TUESDAY EVENING.
CONDITIONS LOOK DRY IN THE LAS VEGAS VALLEY ON TUESDAY THOUGH,
ISOLATED SHRA/TSRA ARE POSSIBLE IN THE SPRING MOUNTAINS. ADDITIONAL
SHRA AND TSRA CHANCES EXIST FOR FRIDAY AND FRIDAY NIGHT IN THE LAS
VEGAS VALLEY.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...ISOLATED SHRA ACTIVITY MAY LINGER THOUGH THE NIGHT IN
THE SOUTHERN GREAT BASIN. SHRA/TSRA WILL AGAIN BE POSSIBLE ON
TUESDAY ESPECIALLY AFTER 18Z NORTH OF KIYK-KDRA-KACZ LINE. WINDS MAY
BE GUSTY AND ERRATIC IN AND NEAR SHRA/TSRA WITH CIGS LOWERING TO 5K-
8K FEET. OTHERWISE LOOK FOR WINDS TO TREND TOWARD TYPICAL DIURNAL
DIRECTIONS AT 10 KTS OR LESS WITH SCT-BKN CLOUDS AOA 10K FEET. &&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
UPDATE/AVIATION...ADAIR
SHORT TERM...STACHELSKI
LONG TERM...HARRISON
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
249 AM EDT TUE MAY 19 2015
.SYNOPSIS...
WARM AND MUGGY CONDITIONS WILL CONTINUE THROUGH THE NIGHT WITH
ADDITIONAL SHOWERS AND THUNDERSTORMS THROUGH SUNRISE. A COLD
FRONT WILL SWEEP THROUGH THE AREA BY EARLY AFTERNOON TUESDAY WITH
MORE SHOWERS AND STORMS POSSIBLE. MUCH COOLER WEATHER WILL FOLLOW
BEHIND THE FRONT FOR THE MIDDLE AND LATER PART OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
500 MB HEIGHT FALLS WERE OCCURRING ACROSS THE REGION THIS EVENING
SUPPORTED BY MODEST MID-UPR LEVEL DIVERGENCE ALOFT. A SERIES OF
WEAK MID-LVL IMPULSES ARE PROGGED TO CONTINUE TO SLIDE FROM THE
OHIO VALLEY OFF TO THE NORTHEAST ACROSS WESTERN...THEN CENTRAL NEW
YORK AS THE ENTIRE COMPLEX SYSTEM DRIFTS EASTWARD. MODERATE SFC
BASED INSTABILITY WILL WANE WITH THE LOSS OF SOLAR HEATING...
HOWEVER...ANOMALOUS MOISTURE IN THE BOUNDARY LAYER WILL REMAIN
AND CONTRIBUTE TO A LINGERING INSTABILITY AXIS ACROSS CNTRL NY AND
NRN PA THROUGH THE NIGHT. FORECAST WAS GENERALLY IN GOOD SHAPE TO
ACCOUNT FOR OCCASIONAL ROUNDS OF TSRA THROUGH THE NIGHT. GFS/GGEM
AND HRRR MODELS DO SUGGEST A POTENTIAL ENHANCEMENT OF HEAVIER
STORMS FOCUSING AGAIN FROM SOUTH CNTRL PA INTO CNTRL NY BETWEEN
03Z-09Z WHICH MATCHES WELL WITH THE INSTABILITY AXIS. WE ARE NO
LONGER THINKING ANY ORGANIZED SEVERE WEATHER OVERNIGHT...BUT HEAVY
RAIN POTENTIAL DOES REMAIN. THE QUESTION BEING IS THERE ENOUGH
EVIDENCE AND CONFIDENCE TO HOIST A FLASH FLOOD WATCH AS THERE HAVE
BEEN LOCALIZED AREAS OF EXTREME RAINFALL TODAY...ESPECIALLY HERE
IN THE HOME COUNTY.
RIGHT NOW...WE THINK THE CONVECTIVE STRENGTH WILL BE WEAKER THAN
EARLIER TODAY GIVEN THE LOSS OF BUOYANCY AND REALLY NO SIGNIFICANT
PUNCH TO THE DYNAMIC FORCING. CAN`T TOTALLY RULE OUT SOME HEAVIER
DOWNPOURS AND POTENTIAL OVERWHELMING OF STORM DRAINS IN ANY
DEVELOPED TOWN OR CITY THAT MIGHT GET A SLOW MOVING STORM...BUT
WILL DEAL WITH THAT ON THE SHORT TERM SHOULD IT UNFOLD.
OTHERWISE...JUST MINOR CHANGES THIS EVENING TO ADJUST FOR TEMPS IN
THE MARINE LAYER TO OUR EAST PUSHING WESTWARD.
COLD FRONT THEN SWEEPS INTO AND THROUGH THE REGION ON TUESDAY
MORNING WITH IMPROVING AND COOLER WEATHER DURING THE AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
QUIET WEATHER IS EXPECTED THROUGH THIS PERIOD WITH MUCH LOWER
TEMPERATURES BEHIND THE COLD FRONT. CANADIAN HIGH PRESSURE WILL
BUILD ACROSS THE GREAT LAKES TOWARD THE MID-ATLANTIC WEDNESDAY
INTO THURSDAY. LOW PRESSURE IS FORECAST TO TRACK FROM THE
TENNESSEE VALLEY TOWARD THE CAROLINAS WEDNESDAY NIGHT INTO
THURSDAY WITH ASSOCIATED RAIN WELL TO OUR SOUTH. GENERALLY WENT
WITH A BLEND OF MAV/MET GUIDANCE FOR TEMPERATURES WEDNESDAY AND
THURSDAY WHICH YIELDED UNSEASONABLY COOL HIGHS IN THE MID 50S TO
MID 60S ON WEDNESDAY... WARMING A BIT INTO THE 60S ON THURSDAY.
LOWS WEDNESDAY NIGHT WILL RANGE FROM THE MID 30S TO MID 40S WITH A
TOUCH OF FROST NOT OUT OF THE QUESTION IN NORMALLY COOLER
LOCATIONS.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
0245 AM UPDATE...WE ONLY MADE A COUPLE MINOR CHANGES TO THE
PREVIOUS FORECAST ISSUED MONDAY AFTERNOON. THE FIRST WAS TO LOWER
HIGH TEMPS A COUPLE DEGREES FOR FRIDAY AS A COLD FRONT PUSHES
THROUGH THE AREA AND THE SECOND CHANGE WAS TO REMOVE THE MENTION
OF PRECIP FOR SUNDAY.
PREVIOUS DISCUSSION...QUIET PD FOR THE XTNDD. SCNDRY FNT APRCHS
THE AREA ON FRI AND MGT GENERATE A FEW SHWRS OVER THE NRN AREAS
WITH PEAK HTG. HGTS BLDS AGAIN AS SFC HIPRES BLDS IN FOR THE
WEEKEND SO XPCT DRY WEATHER INTO SUNDAY. WITH THE TROFINESS ALOFT
IN THE PD...TEMPS WILL BE A BIT COOLER THAN NRML DESPITE THE
DAYTIME SUN.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
EXPECT CONTINUING RESTRICTIONS OVERNIGHT. FOR KBGM/KAVP, IFR CIGS
WILL PERSIST WITH KBGM BELOW ALTERNATE MINS. FOR KITH/KELM/KSYR
EXPECT A REDUCTION IN VISBYS NEAR SUNRISE AS CLEARING STARTS TO
MAKE IT IN AND ALLOW FOR AREAS OF FOG TO DEVELOP. EXPECT LOW
CLOUDS AND FOG TO MIX OUT BY LATER TUESDAY MORNING INTO THE
AFTERNOON WITH VFR EXPECTED BY MID AFTERNOON. HOWEVER AS THE COLD
FRONT CROSSES THE AREA AROUND MIDDAY INTO THE EARLY AFTERNOON THERE
MAY BE SOME ADDITIONAL SCATTERED SHOWERS AND THUNDERSTORMS THAT
COULD POTENTIALLY EFFECT KSYR/KRME/KBGM/KAVP. THESE COULD PRODUCE
GUSTY WINDS.
S/SE WINDS OVERNIGHT AROUND 5-10 KNOTS BECOMING SOUTHWEST AROUND
MID MORNING AT 10 KNOTS THEN NW BY AFTERNOON AT 10-15 KNOTS WITH
GUSTS AROUND 25 KNOTS.
.OUTLOOK...
TUE NGT-SAT...MAINLY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JAB
NEAR TERM...JAB
SHORT TERM...MSE
LONG TERM...DGM/PCF
AVIATION...PCF
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
154 AM EDT TUE MAY 19 2015
.SYNOPSIS...
WARM AND MUGGY CONDITIONS WILL CONTINUE THROUGH THE NIGHT WITH
ADDITIONAL SHOWERS AND THUNDERSTORMS THROUGH SUNRISE. A COLD
FRONT WILL SWEEP THROUGH THE AREA BY EARLY AFTERNOON TUESDAY WITH
MORE SHOWERS AND STORMS POSSIBLE. MUCH COOLER WEATHER WILL FOLLOW
BEHIND THE FRONT FOR THE MIDDLE AND LATER PART OF THE WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
500 MB HEIGHT FALLS WERE OCCURRING ACROSS THE REGION THIS EVENING
SUPPORTED BY MODEST MID-UPR LEVEL DIVERGENCE ALOFT. A SERIES OF
WEAK MID-LVL IMPULSES ARE PROGGED TO CONTINUE TO SLIDE FROM THE
OHIO VALLEY OFF TO THE NORTHEAST ACROSS WESTERN...THEN CENTRAL NEW
YORK AS THE ENTIRE COMPLEX SYSTEM DRIFTS EASTWARD. MODERATE SFC
BASED INSTABILITY WILL WANE WITH THE LOSS OF SOLAR HEATING...
HOWEVER...ANOMALOUS MOISTURE IN THE BOUNDARY LAYER WILL REMAIN
AND CONTRIBUTE TO A LINGERING INSTABILITY AXIS ACROSS CNTRL NY AND
NRN PA THROUGH THE NIGHT. FORECAST WAS GENERALLY IN GOOD SHAPE TO
ACCOUNT FOR OCCASIONAL ROUNDS OF TSRA THROUGH THE NIGHT. GFS/GGEM
AND HRRR MODELS DO SUGGEST A POTENTIAL ENHANCEMENT OF HEAVIER
STORMS FOCUSING AGAIN FROM SOUTH CNTRL PA INTO CNTRL NY BETWEEN
03Z-09Z WHICH MATCHES WELL WITH THE INSTABILITY AXIS. WE ARE NO
LONGER THINKING ANY ORGANIZED SEVERE WEATHER OVERNIGHT...BUT HEAVY
RAIN POTENTIAL DOES REMAIN. THE QUESTION BEING IS THERE ENOUGH
EVIDENCE AND CONFIDENCE TO HOIST A FLASH FLOOD WATCH AS THERE HAVE
BEEN LOCALIZED AREAS OF EXTREME RAINFALL TODAY...ESPECIALLY HERE
IN THE HOME COUNTY.
RIGHT NOW...WE THINK THE CONVECTIVE STRENGTH WILL BE WEAKER THAN
EARLIER TODAY GIVEN THE LOSS OF BUOYANCY AND REALLY NO SIGNIFICANT
PUNCH TO THE DYNAMIC FORCING. CAN`T TOTALLY RULE OUT SOME HEAVIER
DOWNPOURS AND POTENTIAL OVERWHELMING OF STORM DRAINS IN ANY
DEVELOPED TOWN OR CITY THAT MIGHT GET A SLOW MOVING STORM...BUT
WILL DEAL WITH THAT ON THE SHORT TERM SHOULD IT UNFOLD.
OTHERWISE...JUST MINOR CHANGES THIS EVENING TO ADJUST FOR TEMPS IN
THE MARINE LAYER TO OUR EAST PUSHING WESTWARD.
COLD FRONT THEN SWEEPS INTO AND THROUGH THE REGION ON TUESDAY
MORNING WITH IMPROVING AND COOLER WEATHER DURING THE AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY/...
QUIET WEATHER IS EXPECTED THROUGH THIS PERIOD WITH MUCH LOWER
TEMPERATURES BEHIND THE COLD FRONT. CANADIAN HIGH PRESSURE WILL
BUILD ACROSS THE GREAT LAKES TOWARD THE MID-ATLANTIC WEDNESDAY
INTO THURSDAY. LOW PRESSURE IS FORECAST TO TRACK FROM THE
TENNESSEE VALLEY TOWARD THE CAROLINAS WEDNESDAY NIGHT INTO
THURSDAY WITH ASSOCIATED RAIN WELL TO OUR SOUTH. GENERALLY WENT
WITH A BLEND OF MAV/MET GUIDANCE FOR TEMPERATURES WEDNESDAY AND
THURSDAY WHICH YIELDED UNSEASONABLY COOL HIGHS IN THE MID 50S TO
MID 60S ON WEDNESDAY... WARMING A BIT INTO THE 60S ON THURSDAY.
LOWS WEDNESDAY NIGHT WILL RANGE FROM THE MID 30S TO MID 40S WITH A
TOUCH OF FROST NOT OUT OF THE QUESTION IN NORMALLY COOLER
LOCATIONS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
QUIET PD FOR THE XTNDD. SCNDRY FNT APRCHS THE AREA ON FRI AND MGT
GENERATE A FEW SHWRS OVER THE NRN AREAS WITH PEAK HTG. HGTS BLDS
AGAIN AS SFC HIPRES BLDS IN FOR THE WEEKEND SO XPCT DRY WEATHER
INTO SUNDAY. WITH THE TROFINESS ALOFT IN THE PD...TEMPS WILL BE A
BIT COOLER THAN NRML DESPITE THE DAYTIME SUN.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
EXPECT CONTINUING RESTRICTIONS OVERNIGHT. FOR KBGM/KAVP, IFR CIGS
WILL PERSIST WITH KBGM BELOW ALTERNATE MINS. FOR KITH/KELM/KSYR
EXPECT A REDUCTION IN VISBYS NEAR SUNRISE AS CLEARING STARTS TO
MAKE IT IN AND ALLOW FOR AREAS OF FOG TO DEVELOP. EXPECT LOW
CLOUDS AND FOG TO MIX OUT BY LATER TUESDAY MORNING INTO THE
AFTERNOON WITH VFR EXPECTED BY MID AFTERNOON. HOWEVER AS THE COLD
FRONT CROSSES THE AREA AROUND MIDDAY INTO THE EARLY AFTERNOON THERE
MAY BE SOME ADDITIONAL SCATTERED SHOWERS AND THUNDERSTORMS THAT
COULD POTENTIALLY EFFECT KSYR/KRME/KBGM/KAVP. THESE COULD PRODUCE
GUSTY WINDS.
S/SE WINDS OVERNIGHT AROUND 5-10 KNOTS BECOMING SOUTHWEST AROUND
MID MORNING AT 10 KNOTS THEN NW BY AFTERNOON AT 10-15 KNOTS WITH
GUSTS AROUND 25 KNOTS.
.OUTLOOK...
TUE NGT-SAT...MAINLY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JAB
NEAR TERM...JAB
SHORT TERM...MSE
LONG TERM...DGM
AVIATION...PCF/RRM
AREA FORECAST DISCUSSION
NWS RALEIGH NC
318 PM EDT TUE MAY 19 2015
.SYNOPSIS...A COLD FRONT WILL MOVE ACROSS CENTRAL NORTH CAROLINA
TONIGHT...AND THEN STALL OVER SOUTH CAROLINA ON WEDNESDAY. THE
FRONT WILL THEN RETREAT NORTH IN ADVANCE OF AN AREA OF LOW PRESSURE
THAT WILL CROSS THE CAROLINAS ON THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 225 PM TUESDAY...
SCATTERED SHOWERS AND ISOLD TSTMS HAVE BROKEN OUT ACROSS PARTS OF
CENTRAL NC AS EXPECTED...WITH ACTIVITY EXPECTED TO CONTINUE TO
EXPAND AND MOVE EAST THROUGH THE REMAINDER OF THE AFTERNOON. LATEST
MESOANALYSIS STILL SHOWS THE BEST MOISTURE AND INSTABILITY LOCATED
ACROSS OUR EASTERN ZONES...AND SUGGESTS THAT SHOWER/TSTM COVERAGE
SHOULD INCREASE AS THEY EVOLVE EASTWARD LATER THIS AFTERNOON.
ANOTHER NOTABLE FEATURE IS A MID LEVEL VORT CURRENTLY MOVING E
ACROSS NE SC. THIS FEATURE MAY AID THE DEVELOPMENT AND MAINTENANCE
OF SHOWER/TSTM ACTIVITY ACROSS OUR SE ZONES AS IT MOVES EAST THE
REST OF THIS AFTERNOON. OTHERWISE...GIVEN WEAK MID-LEVEL LAPSE RATES
AND WEAK SHEAR...CELL INTENSITY SHOULD BE LIMITED...BUT STILL
CAPABLE OF PRODUCING BRIEF INTENSE DOWNPOURS GIVEN THE ABUNDANT
MOISTURE AND ABOVE-CLIMO PWAT VALUES IN PLACE ACROSS THE AREA.
SHOWER/TSTM ACTIVITY IS THEN EXPECTED TO DIMINISH AND MOVE EAST
TOWARD THE COAST LATER THIS EVENING.
OVERNIGHT...THE COLD FRONT WHICH IS CURRENTLY EXTENDING FROM
PITTSBURGH TO NASHVILLE TO MEMPHIS WILL MOVE S AND E AND ACROSS OUR
CWA. LATEST HRRR SUGGESTS AN ISOLD SHOWER CAN`T BE RULED OUT WITH
PASSAGE OF THE FRONT...BUT MOST PLACES WILL REMAIN DRY AS THE FRONT
MOVES ACROSS. MORE LIKELY WILL BE THE FORMATION OF SOME FOG...ESP
ACROSS AREAS THAT RECEIVE HEAVIER RAINFALL THIS AFTERNOON AND
EVENING. LOW TEMPS WILL BE COOLEST ACROSS THE NW (AROUND 60) WHERE
THE FRONT WILL MOVE THROUGH EARLIER IN THE NIGHT...VERSUS OUR SE
ZONES WHERE THE FROPA WILL OCCUR LATER IN THE NIGHT AND THUS HAVE
LOW IN THE MID TO UPPER 60S.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 225 PM TUESDAY...
THE COLD FRONT WILL STALL TO OUR SOUTH ACROSS SC ON WEDNESDAY. THIS
WILL ALLOW DRIER AND SLIGHTLY COOLER AIR TO MOVE INTO OUR AREA FROM
THE NW. AS SUCH...LOOK FOR FAIR WEATHER WITH HIGHS FROM THE MID 80S
NORTH TO UPPER 80S SOUTH.
WEDNESDAY NIGHT...A SHORT WAVE OVER THE MISS VALLEY WILL MOVE EAST
AND INDUCE A LOW PRESSURE WAVE ALONG THE OLD BOUNDARY TO OUR SOUTH.
THERE ARE STILL MODEL DIFFERENCES REGARDING WHERE (PARTICULARLY HOW
FAR NORTH) THAT WAVE WILL SET UP...BUT EITHER WAY IT APPEARS THAT A
FEW SHOWERS WILL BE POSSIBLE ACROSS OUR PIEDMONT ZONES LATER
OVERNIGHT. LOWS WILL RANGE FROM AROUND 60 NW TO MID 60S SE.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 315 PM TUESDAY...
THURSDAY TROUGH FRIDAY NIGHT: A QUICK MOVING S/W DISTURBANCE IS
EXPECTED TO MOVE FROM THE PLAINS TO OFF THE MID-ATLANTIC/NORTHEAST
U.S. COAST BY FRIDAY MORNING... SPREADING SHOWERS AND SOME STORMS
ACROSS CENTRAL ON THURSDAY. WHILE THE DISTURBANCE WILL TRACK JUST TO
OUR NORTH...AN AREA OF LOW PRESSURE IN RESPONSE WILL DEVELOP/DEEPEN
ALONG THE OLD FRONTAL ZONE NEAR THE NC/SC BORDER... THEN LIFT NORTH
AND EASTWARD ON THURSDAY NIGHT INTO FRIDAY. THIS SHOULD BRING A WIDE
RANGE IN TEMPS ACROSS CENTRAL NC ON THURSDAY... WITH THE POTENTIAL
FOR SOME ROTATING STORMS NEAR THE BOUNDARY... AS DEEP LAYER SHEAR IS
EXPECTED TO INCREASE TO 30 TO 35 KTS WITH A BACKED SURFACE FLOW AS
THE SURFACE APPROACHES. HOWEVER... WITH THE POSSIBILITY OF ON GOING
SHOWERS AND WIDESPREAD CLOUD COVER THERE IS QUITE A BIT OF
UNCERTAINTY WRT HOW MUCH DESTABILIZATION WE WILL SEE IN THE
DEVELOPING WARM SECTOR. THUS...SPC HAS PLACED SOUTHEASTERN/EASTERN
PORTIONS OF CENTRAL NC IN A MARGINAL RISK FOR SEVERE STORMS. FOR NOW
WILL CONTINUE TO MENTION A THREAT FOR ISOLATED SEVERE STORMS ACROSS
OUR SE/E COUNTIES IN THE HWO FOR THURSDAY. WILL GO WITH HIGHS TEMPS
ON THURSDAY RANGING FROM THE UPPER 60S/NEAR 70 (MAYBE NOT COOL
ENOUGH EVEN) NEAR THE NC/VA BORDER TO LOWER TO MID 80S
SOUTH/SOUTHEAST.
THE PRIMARY SURFACE LOW IS EXPECTED TO LIFT OFF TO THE NORTHEAST
LATE THURSDAY NIGHT INTO FRIDAY... BRINGING A RETURN TO DRY AND
QUIET WEATHER... WITH CLEARING/SUNNY SKIES BY FRIDAY AFTERNOON
ONWARD AS SURFACE HIGH PRESSURE BUILDS INTO THE AREA FROM THE
NORTHWEST. EXPECT HIGHS ON FRIDAY WILL BE IN THE UPPER 70S TO LOWER
80S. LOWS FRIDAY MORNING WILL BE DEPENDENT ON THE AMOUNT OF CLEARING
AND ANY LINGERING COOL STABLE AIRMASS. FOR NOW WILL GO WITH LOWS
RANGING FROM THE 50S NORTH TO THE MID 60S SE. LOWS SATURDAY... WITH
SURFACE HIGH PRESSURE TO THE NORTH OF THE REGION... ARE EXPECTED TO
BE IN THE MID TO UPPER 50S.
SATURDAY THROUGH TUESDAY: SURFACE HIGH PRESSURE WILL MOVE ACROSS THE
REGION THIS WEEKEND AND OFFSHORE EARLY NEXT WEEK AS MID LEVEL
RIDGING BEGINS TO BUILD AGAIN. THIS WILL YIELD A WARMING TREND EACH
DAY FROM HIGHS IN THE UPPER 70S TO LOWER 80S ON SATURDAY TO THE
UPPER 80S TO LOWER 90S ON TUESDAY. LOWS WILL FOLLOW A SIMILAR
TREND... 50S THIS WEEKEND TO THE MID TO UPPER 60S BY TUESDAY
MORNING. DRY CONDITIONS ARE GENERALLY EXPECTED FOR THIS PERIOD...
WITH INCREASING CHANCES OF AT LEAST SOME ISOLATED OR WIDELY
SCATTERED SHOWERS AND STORMS BY TUESDAY AFTERNOON (BEST CHANCE
NORTHWEST) AS LOW LEVEL MOISTURE INCREASES IN RETURN FLOW.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 225 PM TUESDAY...
SCATTERED SHOWERS AND TSTMS WILL BE POSSIBLE ACROSS MUCH OF CENTRAL
NC THROUGH THE REMAINDER OF THE AFTERNOON. THESE SHOWERS WILL
LOCALLY AND BRIEFLY REDUCE CIGS AND VSBY TO IFR OR MVFR. OUTSIDE OF
THESE SHOWERS/TSTMS...VFR CONDITIONS CAN BE EXPECTED. THE ACTIVITY
WILL WIND DOWN FROM WEST TO EAST THIS EVENING...ENDING AT INT/GSO BY
19/23Z...RDU BY 20/00Z...AND RWI/FAY BY 20/01Z. AREAS OF FOG WILL BE
POSSIBLE OVERNIGHT WHERE THE HEAVIEST RAIN OCCURS...BUT CONFIDENCE
RIGHT NOW IS STILL TOO LOW TO INCLUDE IN THE TAFS. WITH DRIER AIR
ARRIVING BEHIND THE FRONT...EXPECT VFR CONDITIONS DURING THE DAYTIME
WEDNESDAY.
OUTLOOK: AN AREA OF LOW PRESSURE WILL TRACK ACROSS THE CAROLINAS AND
RESULT IN A CHANCE OF SUB-VFR CEILINGS AND RAIN LATE WED NIGHT AND
EARLY THU...FOLLOWED BY SHOWERS AND STORMS THU AFTERNOON.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RAH
NEAR TERM...RAH
SHORT TERM...RAH
LONG TERM...RAH
AVIATION...RAH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
225 PM EDT TUE MAY 19 2015
.SYNOPSIS...A COLD FRONT WILL MOVE ACROSS CENTRAL NORTH CAROLINA
TONIGHT...AND THEN STALL OVER SOUTH CAROLINA ON WEDNESDAY. THE
FRONT WILL THEN RETREAT NORTH IN ADVANCE OF AN AREA OF LOW PRESSURE
THAT WILL CROSS THE CAROLINAS ON THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 225 PM TUESDAY...
SCATTERED SHOWERS AND ISOLD TSTMS HAVE BROKEN OUT ACROSS PARTS OF
CENTRAL NC AS EXPECTED...WITH ACTIVITY EXPECTED TO CONTINUE TO
EXPAND AND MOVE EAST THROUGH THE REMAINDER OF THE AFTERNOON. LATEST
MESOANALYSIS STILL SHOWS THE BEST MOISTURE AND INSTABILITY LOCATED
ACROSS OUR EASTERN ZONES...AND SUGGESTS THAT SHOWER/TSTM COVERAGE
SHOULD INCREASE AS THEY EVOLVE EASTWARD LATER THIS AFTERNOON.
ANOTHER NOTABLE FEATURE IS A MID LEVEL VORT CURRENTLY MOVING E
ACROSS NE SC. THIS FEATURE MAY AID THE DEVELOPMENT AND MAINTENANCE
OF SHOWER/TSTM ACTIVITY ACROSS OUR SE ZONES AS IT MOVES EAST THE
REST OF THIS AFTERNOON. OTHERWISE...GIVEN WEAK MID-LEVEL LAPSE RATES
AND WEAK SHEAR...CELL INTENSITY SHOULD BE LIMITED...BUT STILL
CAPABLE OF PRODUCING BRIEF INTENSE DOWNPOURS GIVEN THE ABUNDANT
MOISTURE AND ABOVE-CLIMO PWAT VALUES IN PLACE ACROSS THE AREA.
SHOWER/TSTM ACTIVITY IS THEN EXPECTED TO DIMINISH AND MOVE EAST
TOWARD THE COAST LATER THIS EVENING.
OVERNIGHT...THE COLD FRONT WHICH IS CURRENTLY EXTENDING FROM
PITTSBURGH TO NASHVILLE TO MEMPHIS WILL MOVE S AND E AND ACROSS OUR
CWA. LATEST HRRR SUGGESTS AN ISOLD SHOWER CAN`T BE RULED OUT WITH
PASSAGE OF THE FRONT...BUT MOST PLACES WILL REMAIN DRY AS THE FRONT
MOVES ACROSS. MORE LIKELY WILL BE THE FORMATION OF SOME FOG...ESP
ACROSS AREAS THAT RECEIVE HEAVIER RAINFALL THIS AFTERNOON AND
EVENING. LOW TEMPS WILL BE COOLEST ACROSS THE NW (AROUND 60) WHERE
THE FRONT WILL MOVE THROUGH EARLIER IN THE NIGHT...VERSUS OUR SE
ZONES WHERE THE FROPA WILL OCCUR LATER IN THE NIGHT AND THUS HAVE
LOW IN THE MID TO UPPER 60S.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 225 PM TUESDAY...
THE COLD FRONT WILL STALL TO OUR SOUTH ACROSS SC ON WEDNESDAY. THIS
WILL ALLOW DRIER AND SLIGHTLY COOLER AIR TO MOVE INTO OUR AREA FROM
THE NW. AS SUCH...LOOK FOR FAIR WEATHER WITH HIGHS FROM THE MID 80S
NORTH TO UPPER 80S SOUTH.
WEDNESDAY NIGHT...A SHORT WAVE OVER THE MISS VALLEY WILL MOVE EAST
AND INDUCE A LOW PRESSURE WAVE ALONG THE OLD BOUNDARY TO OUR SOUTH.
THERE ARE STILL MODEL DIFFERENCES REGARDING WHERE (PARTICULARLY HOW
FAR NORTH) THAT WAVE WILL SET UP...BUT EITHER WAY IT APPEARS THAT A
FEW SHOWERS WILL BE POSSIBLE ACROSS OUR PIEDMONT ZONES LATER
OVERNIGHT. LOWS WILL RANGE FROM AROUND 60 NW TO MID 60S SE.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 335 AM TUESDAY...
A WAVE OF LOW PRESSURE MOVING ALONG THE FRONTAL ZONE DRAPED ACROSS
THE MID-SOUTH AND CAROLINAS IS FORECAST TO SLOWLY DEEPEN AS IT MOVES
SOMEWHERE NEAR THE NC/SC ON THURSDAY AND THEN OFF THE NC COAST
THURSDAY NIGHT. THE GFS CONTINUES TO BE A WEAKER AND SOUTHERN
OUTLIER WHEN IT COMES TO THE LOCATION OF THE FRONT AND TRACK OF THE
WAVE...SO WILL LEAN TOWARD THE ECMWF/NAM...WHICH HAVE SUPPORT FROM
THE ECMWF ENSEMBLE. THE FORCING ALOFT WILL BE MOSTLY WEAK WITH THIS
SYSTEM AS THE LEAD SOUTHERN STREAM SHORTWAVE DEAMPLIFIES OVER THE
MIDWEST AND MERGES WITH A TRAILING NORTHERN STREAM WAVE THAT PASSES
TO OUR NORTH THURSDAY AFTERNOON. HOWEVER...WEAK HEIGHT FALLS AND
GOOD LOW-LEVEL CONVERGENCE NEAR THE FRONTAL ZONE/SFC LOW WILL LEAD
TO SCATTERED SHOWERS/STORMS THAT MAY BECOME NUMEROUS OVER THE
COASTAL PLAIN THURSDAY AFTERNOON/EVENING PENDING DESTABILIZATION AS
DEWPOINTS CREEP BACK INTO THE UPPER 60S. IF MORNING SHOWERS AND/OR
CLOUDS DONT LIMIT HEATING TOO MUCH THEN SOME WEAK CAPE MAY DEVELOP.
A CONDITIONAL SEVERE THREAT MAY THEN EXIST GIVEN 30-35KT OF MID-
LEVEL FLOW AND BACKED LOW-LEVEL FLOW AHEAD OF THE SURFACE
LOW....MAINLY EAST OF I-95 WHERE THE THE PARAMETER SPACE FOR SOME
ROTATING STORMS WOULD BE MAXIMIZED. THE DEEPER NAM SHOWS BETTER
POTENTIAL THAN THE ECMWF...SO AT THIS TIME THE SEVERE THREAT IS
LIKELY LOW BUT WORTH WATCHING. HIGHS WILL RANGE FROM THE MID 70S
NORTH TO LOW OR MID 80S SOUTH DEPENDING ON HOW ROBUST MID CLOUDS ARE
AS THEY ADVECT IN FROM THE WEST EARLY IN THE DAY.
PRECIP WILL COME TO AN END THURSDAY NIGHT AND EARLY FRIDAY AS THE
SURFACE LOW MOVES OFF THE COAST AND A MUCH MORE STABLE AIRMASS
FILTERS OVER THE REGION...COURTESY OF A RELATIVELY STRONG HIGH
PRESSURE THAT WILL BUILD ACROSS THE GREAT LAKES. THICKNESSES DROP
OFF SIGNIFICANTLY FRIDAY AND SUGGEST HIGHS IN THE MID 70S TO LOW 80S
FRIDAY AND SATURDAY. THE PATTERN WILL THEN SHIFT BACK TO TROUGHING
OUT WEST AND A SUB-TROPICAL RIDGE OVER THE SOUTHEAST US...WHICH
WILL BRING TEMPS BACK TO AND ABOVE NORMAL BY EARLY NEXT WEEK.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 225 PM TUESDAY...
SCATTERED SHOWERS AND TSTMS WILL BE POSSIBLE ACROSS MUCH OF CENTRAL
NC THROUGH THE REMAINDER OF THE AFTERNOON. THESE SHOWERS WILL
LOCALLY AND BRIEFLY REDUCE CIGS AND VSBY TO IFR OR MVFR. OUTSIDE OF
THESE SHOWERS/TSTMS...VFR CONDITIONS CAN BE EXPECTED. THE ACTIVITY
WILL WIND DOWN FROM WEST TO EAST THIS EVENING...ENDING AT INT/GSO BY
19/23Z...RDU BY 20/00Z...AND RWI/FAY BY 20/01Z. AREAS OF FOG WILL BE
POSSIBLE OVERNIGHT WHERE THE HEAVIEST RAIN OCCURS...BUT CONFIDENCE
RIGHT NOW IS STILL TOO LOW TO INCLUDE IN THE TAFS. WITH DRIER AIR
ARRIVING BEHIND THE FRONT...EXPECT VFR CONDITIONS DURING THE DAYTIME
WEDNESDAY.
OUTLOOK: AN AREA OF LOW PRESSURE WILL TRACK ACROSS THE CAROLINAS AND
RESULT IN A CHANCE OF SUB-VFR CEILINGS AND RAIN LATE WED NIGHT AND
EARLY THU...FOLLOWED BY SHOWERS AND STORMS THU AFTERNOON.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RAH
NEAR TERM...RAH
SHORT TERM...RAH
LONG TERM...22
AVIATION...RAH
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
722 AM EDT TUE MAY 19 2015
.SYNOPSIS...
HIGH PRESSURE CENTERED OVER THE DAKOTAS WILL BUILD SOUTHEAST
INTO THE PLAIN STATES AND EXTEND A RIDGE INTO THE REGION THROUGH
MID WEEK. FRIDAY MORNING A COLD FRONT WILL DROP SOUTH ACROSS THE
GREAT LAKES AND INTO NORTHERN OHIO. HIGH PRESSURE WILL
FOLLOW...BUILDING ACROSS THE REGION SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...COLD FRONT NOW THROUGH MOST OF THE AREA WITH WINDS NOW
FROM THE WNW. ADJUSTED HOURLY TEMPS INTO THE AFTERNOON TOWARD
THE HRRR TO CAPTURE THE NON DIURNAL TRENDS. CLOUDS ADVANCING
TOWARD THE AREA FROM THE NORTHWEST ASSOCIATED WITH WRAP AROUND
MOISTURE AND COOL AIR ALOFT. CURRENT TIMING STILL LOOKS GOOD
GETTING INTO KTOL AREA BETWEEN 8-9AM AND KCLE A LITTLE AFTER NOON
SO NO CHANGES TO SKY GRIDS.
ORIGINAL...COLD FRONT PROGRESSING EAST ACROSS THE AREA EARLY THIS
MORNING WITH SWLY FLOW KCLE-KMFD AND NWLY FLOW AT KTOL AND KFDY.
AT THIS TIME NO PRECIP IS ASSOCIATED WITH THE BOUNDARY AND NON IS
EXPECTED. SKIES CLEAR 100 MILES EITHER SIDE OF THE FRONT WITH
CLEARING JUST ABOUT TO ENTER NWRN PA. ON THE OTHER HAND...WRAP
AROUND MOISTURE/CLOUDS DROPPING ESE ACROSS SOUTHERN LAKE MI. THIS
LOW LEVEL CLOUD DECK IS EXPECTED INTO NWRN TOL AREA 12-13Z BASED
ON TIMING OF CURRENT MOVEMENT. CLOUDS REACH KCLE AROUND 17Z. HIGH
TODAY IN THE 60S BUT TEMPS WILL BE STEADY/SLOWLY FALLING POST
FRONT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
NO BIG CHANGE TO THE SHORT TERM THINKING. MUCH COOLER AND
GENERALLY DRY CONDITIONS CONTINUE TO BE EXPECTED DURING THIS
PERIOD AS HIGH PRESSURE TO OUR WEST FORCES MUCH COOLER AIR INTO
THE REGION. THIS HIGH WILL GRADUALLY BUILD EAST THROUGH MID WEEK.
THERE IS STILL A POTENTIAL FOR FROST EARLY WEDNESDAY MORNING WHERE
SKIES CLEAR. WILL NOT ISSUE AN ADVISORY JUST YET AS TEMPS MARGINAL
AND CLOUDS STILL MOVING TOWARD THE AREA. A WEAK SHORTWAVE EARLY
THURSDAY COULD PRODUCE A BRIEF SPRINKLE. PUT IN SLIGHT CHANCE FOR
MOST BUT WILL NOT GET INTO THE ZFP. ANOTHER COLD FRONT WILL DROP
ACROSS THE REGION FRIDAY AS UPPER TROF DIGS INTO QUEBEC. THIS
SHOULD AFFECT NORTHEAST OHIO AND NWRN PA TEMPS THE MOST BASED ON
PACKING AND ORIENTATION. HIGHS WEDNESDAY FROM THE MID 50S TO MID
60S. EXPECT A GRADUAL WARMUP INTO THURSDAY. FRIDAY WESTERN
COUNTIES COULD TACK ON ANOTHER COUPLE DEGREES BUT NERN OHIO AND
NWRN PA LIKELY DROP BACK TO 60 TO 65.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
UPPER LEVEL RIDGE BECOMES AMPLIFIED OVER THE WEEKEND ACROSS THE
MISSISSIPPI VALLEY REGION. THIS WILL HELP TO BUILD SURFACE HIGH
PRESSURE AS IT MOVES EAST OVER THE FORECAST AREA. EVENTUALLY...THE
SURFACE HIGH PUSHES EAST TO THE EAST COAST BY SUNDAY MORNING. THIS
WILL SET UP ANOTHER ROUND OF WARM AIR ADVECTION INTO THE FORECAST
AREA OVER THE WEEKEND. THE UNFORTUNATE SCENARIO WILL OCCUR WHERE THE
GULF OF MEXICO WILL OPEN UP AND SEND A STREAM OF MOISTURE NORTH
ACROSS EASTERN TEXAS INTO THE FORECAST AREA. THIS CONVEYOR BELT OF
MOISTURE WILL UNDOUBTEDLY BRING WITH IT A THREAT FOR SHOWERS AND
THUNDERSTORMS DURING THE LATTER HALF OF THE MEMORIAL DAY WEEKEND.
WILL CONTINUE THE GRADUAL INCREASE OF SHOWERS AND THUNDERSTORMS
SUNDAY INTO MONDAY FROM WEST TO EAST. HAVE A GUT FEELING WE MAY NEED
TO UP POPS TO LIKELY ALL AREAS FOR MONDAY. TEMPERATURE FORECAST IS A
TOUGH ONE AS WE GET INTO THE WEEKEND AND MONDAY AS THEY WILL BE
HIGHLY DEPENDENT ON HOW MUCH SUN BREAKS THROUGH THE OVERCAST BETWEEN
SHOWERS AND THUNDERSTORMS. IF WE GET A PERIOD OF SUN ANY OF THOSE
DAYS...MAX TEMPERATURES WILL BE UNDER FORECAST.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
COLD FRONT SHOULD CONTINUE TO MOVE EAST THROUGH THE REST OF THE
MORNING HOURS. SKIES CLEARED OVER MUCH OF THE FORECAST AREA. THE
EXCEPTION IS THE EXTREME EAST WHERE SOME LOWER CLOUDS FORMED BUT
APPEARS IT SHOULD MOVE EAST AS WELL. A STRATOCUMULUS DECK AROUND
3500 TO 4000 FEET WILL MOVE EAST INTO THE AREA THIS MORNING AND
LINGER OVER MOST OF THE AREA THROUGH MUCH OF THE TAF PERIOD. WINDS
WILL REMAIN AT 10 TO 15 KNOTS UNTIL THIS EVENING AND THEN
DIMINISH.
.OUTLOOK... NON-VFR POSSIBLE BEHIND A COLD FRONT IN NE OH/NW PA
TUESDAY NIGHT.
&&
.MARINE...
A SMALL CRAFT ADVISORY WILL BE NEEDED THIS AFTERNOON AND EARLY
TONIGHT AS WINDS INCREASE OUT OF THE WEST AND BECOME NORTHERLY
ACROSS THE LAKE. WINDS DO DIMINISH STARTING TONIGHT AND THEN `
CONSIDERABLY WEDNESDAY INTO WEDNESDAY NIGHT. WINDS DO INCREASE A
TAD OUT OF THE SOUTHWEST ON THURSDAY AHEAD OF A WEAK COLD FRONT
THAT MOVES SOUTHEAST ACROSS THE LAKE. AT THIS TIME...IT LOOKS LIKE
WINDS SHOULD BE WEAK ENOUGH TO AVOID SMALL CRAFT ADVISORIES. WINDS
THEN BECOME LIGHT AND VARIABLE AS HIGH PRESSURE BUILDS SOUTHEAST
ACROSS THE LAKE HEADING INTO THE WEEKEND.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 10 PM EDT
THIS EVENING FOR LEZ148-149.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...LOMBARDY
AVIATION...LOMBARDY
MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
630 AM EDT TUE MAY 19 2015
.SYNOPSIS...
HIGH PRESSURE CENTERED OVER THE DAKOTAS WILL BUILD SOUTHEAST
INTO THE PLAIN STATES AND EXTEND A RIDGE INTO THE REGION THROUGH
MID WEEK. FRIDAY MORNING A COLD FRONT WILL DROP SOUTH ACROSS THE
GREAT LAKES AND INTO NORTHERN OHIO. HIGH PRESSURE WILL
FOLLOW...BUILDING ACROSS THE REGION SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...COLD FRONT NOW THROUGH MOST OF THE AREA WITH WINDS NOW
FROM THE WNW. ADJUSTED HOURLY TEMPS INTO THE AFTERNOON TOWARD
THE HRRR TO CAPTURE THE NON DIURNAL TRENDS. CLOUDS ADVANCING
TOWARD THE AREA FROM THE NORTHWEST ASSOCIATED WITH WRAP AROUND
MOISTURE AND COOL AIR ALOFT. CURRENT TIMING STILL LOOKS GOOD
GETTING INTO KTOL AREA BETWEEN 8-9AM AND KCLE A LITTLE AFTER NOON
SO NO CHANGES TO SKY GRIDS.
ORIGINAL...COLD FRONT PROGRESSING EAST ACROSS THE AREA EARLY THIS
MORNING WITH SWLY FLOW KCLE-KMFD AND NWLY FLOW AT KTOL AND KFDY.
AT THIS TIME NO PRECIP IS ASSOCIATED WITH THE BOUNDARY AND NON IS
EXPECTED. SKIES CLEAR 100 MILES EITHER SIDE OF THE FRONT WITH
CLEARING JUST ABOUT TO ENTER NWRN PA. ON THE OTHER HAND...WRAP
AROUND MOISTURE/CLOUDS DROPPING ESE ACROSS SOUTHERN LAKE MI. THIS
LOW LEVEL CLOUD DECK IS EXPECTED INTO NWRN TOL AREA 12-13Z BASED
ON TIMING OF CURRENT MOVEMENT. CLOUDS REACH KCLE AROUND 17Z. HIGH
TODAY IN THE 60S BUT TEMPS WILL BE STEADY/SLOWLY FALLING POST
FRONT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
NO BIG CHANGE TO THE SHORT TERM THINKING. MUCH COOLER AND
GENERALLY DRY CONDITIONS CONTINUE TO BE EXPECTED DURING THIS
PERIOD AS HIGH PRESSURE TO OUR WEST FORCES MUCH COOLER AIR INTO
THE REGION. THIS HIGH WILL GRADUALLY BUILD EAST THROUGH MID WEEK.
THERE IS STILL A POTENTIAL FOR FROST EARLY WEDNESDAY MORNING WHERE
SKIES CLEAR. WILL NOT ISSUE AN ADVISORY JUST YET AS TEMPS MARGINAL
AND CLOUDS STILL MOVING TOWARD THE AREA. A WEAK SHORTWAVE EARLY
THURSDAY COULD PRODUCE A BRIEF SPRINKLE. PUT IN SLIGHT CHANCE FOR
MOST BUT WILL NOT GET INTO THE ZFP. ANOTHER COLD FRONT WILL DROP
ACROSS THE REGION FRIDAY AS UPPER TROF DIGS INTO QUEBEC. THIS
SHOULD AFFECT NORTHEAST OHIO AND NWRN PA TEMPS THE MOST BASED ON
PACKING AND ORIENTATION. HIGHS WEDNESDAY FROM THE MID 50S TO MID
60S. EXPECT A GRADUAL WARMUP INTO THURSDAY. FRIDAY WESTERN
COUNTIES COULD TACK ON ANOTHER COUPLE DEGREES BUT NERN OHIO AND
NWRN PA LIKELY DROP BACK TO 60 TO 65.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
UPPER LEVEL RIDGE BECOMES AMPLIFIED OVER THE WEEKEND ACROSS THE
MISSISSIPPI VALLEY REGION. THIS WILL HELP TO BUILD SURFACE HIGH
PRESSURE AS IT MOVES EAST OVER THE FORECAST AREA. EVENTUALLY...THE
SURFACE HIGH PUSHES EAST TO THE EAST COAST BY SUNDAY MORNING. THIS
WILL SET UP ANOTHER ROUND OF WARM AIR ADVECTION INTO THE FORECAST
AREA OVER THE WEEKEND. THE UNFORTUNATE SCENARIO WILL OCCUR WHERE THE
GULF OF MEXICO WILL OPEN UP AND SEND A STREAM OF MOISTURE NORTH
ACROSS EASTERN TEXAS INTO THE FORECAST AREA. THIS CONVEYOR BELT OF
MOISTURE WILL UNDOUBTEDLY BRING WITH IT A THREAT FOR SHOWERS AND
THUNDERSTORMS DURING THE LATTER HALF OF THE MEMORIAL DAY WEEKEND.
WILL CONTINUE THE GRADUAL INCREASE OF SHOWERS AND THUNDERSTORMS
SUNDAY INTO MONDAY FROM WEST TO EAST. HAVE A GUT FEELING WE MAY NEED
TO UP POPS TO LIKELY ALL AREAS FOR MONDAY. TEMPERATURE FORECAST IS A
TOUGH ONE AS WE GET INTO THE WEEKEND AND MONDAY AS THEY WILL BE
HIGHLY DEPENDENT ON HOW MUCH SUN BREAKS THROUGH THE OVERCAST BETWEEN
SHOWERS AND THUNDERSTORMS. IF WE GET A PERIOD OF SUN ANY OF THOSE
DAYS...MAX TEMPERATURES WILL BE UNDER FORECAST.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
COLD FRONT IS GRADUALLY PUSHING EAST ACROSS THE WESTERN HALF OF
THE FORECAST AREA AT THIS TIME AND SHOULD CONTINUE TO MOVE EAST
THROUGH THE REST OF THE MORNING HOURS. SKIES CLEARING OUT WITH THE
COLD FRONT FOR A PERIOD OF TIME. A STRATOCUMULUS DECK AROUND 4K
FEET WILL MOVE EAST INTO THE AREA THIS MORNING AND LINGER OVER
MOST OF THE AREA THROUGH MUCH OF THE TAF PERIOD. WINDS WILL
INCREASE ALONG THE FRONTAL BOUNDARY AND REMAIN AT 10 TO 15 KNOTS
UNTIL THIS EVENING AND THEN DIMINISH. LOW CLOUDS AT YOUNGSTOWN AND
AKRON CANTON SHOULD GRADUALLY SHIFT EAST THIS MORNING AS WELL.
.OUTLOOK... NON-VFR POSSIBLE BEHIND A COLD FRONT IN NE OH/NW PA
TUESDAY NIGHT.
&&
.MARINE...
A SMALL CRAFT ADVISORY WILL BE NEEDED THIS AFTERNOON AND EARLY
TONIGHT AS WINDS INCREASE OUT OF THE WEST AND BECOME NORTHERLY
ACROSS THE LAKE. WINDS DO DIMINISH STARTING TONIGHT AND THEN `
CONSIDERABLY WEDNESDAY INTO WEDNESDAY NIGHT. WINDS DO INCREASE A
TAD OUT OF THE SOUTHWEST ON THURSDAY AHEAD OF A WEAK COLD FRONT
THAT MOVES SOUTHEAST ACROSS THE LAKE. AT THIS TIME...IT LOOKS LIKE
WINDS SHOULD BE WEAK ENOUGH TO AVOID SMALL CRAFT ADVISORIES. WINDS
THEN BECOME LIGHT AND VARIABLE AS HIGH PRESSURE BUILDS SOUTHEAST
ACROSS THE LAKE HEADING INTO THE WEEKEND.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 10 PM EDT
THIS EVENING FOR LEZ148-149.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...LOMBARDY
AVIATION...LOMBARDY
MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
226 AM EDT TUE MAY 19 2015
.SYNOPSIS...
COLD FRONT PUSHES EAST THIS MORNING. UPPER LEVEL DISTURBANCE
PASSES BY WEDNESDAY NIGHT INTO THURSDAY. WEAK DRY COLD FRONT
PUSHES SOUTH FRIDAY. HIGH PRESSURE IN CONTROL FOR SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
SENT A QUICK UPDATE TO ADJUST POPS PER LATEST RADAR IMAGES. A
BROKEN LINE OF SHOWERS...WITH FEW LIGHTNING STRIKES TO OUR FAR
SOUTH OVER THE WESTERN SLOPES OF WV AND EXTREME SOUTHWEST VA...MOVING
EAST AROUND 15 KNOTS. BEHIND THIS LINE RADAR LOOKS DRY EVEN ALONG
THE UPCOMING COLD FRONT. THEREFORE...KEPT HIGH CHANCE WITH THE
SHOWERS AND REMOVE CHANCES BEHIND IT. REST OF FORECAST REMAINS ON
TRACK.
PREVIOUS DISCUSSION BELOW...
815 PM UPDATE...
FINE TUNED POPS TO KEY IN MAINLY ON BROKEN LINE OF SHOWERS
CROSSING THE OHIO RIVER AS OF 00Z. THE LINE CLOSER TO THE FRONT
WILL MOSTLY FALL APART BEFORE REACHING THE FCST AREA OVERNIGHT
TONIGHT. THE THREAT FOR THUNDER OVERALL QUICKLY WANES TONIGHT. THE
COLD FRONT CROSSES/MIXES THROUGH TUE MORNING.
PREV DISCN...
SCATTERED POPCORN CONVECTION IS BEING SEEN ACROSS THE AREA THIS
AFTERNOON...AS MOIST AIR MASS HEATS UP IN BOUNDARY LAYER HEATING.
OTHERWISE...SLIGHTLY MORE ORGANIZED CONVECTION NOTED OVER EASTERN
KY AND SOUTHERN OH...AS WEAK VORT FEATURE APPROACHES FROM THE
WEST. IT APPEARS THE LATEST RAP RUNS HAVE A FAIR HANDLE ON THE
OVERALL MASS FIELDS AND THE PROGRESSION OF FEATURES ACROSS
TONIGHT. USED A RATHER BROAD BRUSH APPROACH TO COVER POPS THIS
AFTERNOON AND THIS EVENING. HAVE FRONT CROSSING LATE TONIGHT AND
EARLY MORNING. SPEED UP TIMING SLIGHTLY...BY AN HOUR OR TWO...NOT
MUCH TO REALLY MAKE A CHANGE TO THE OVERALL FORECAST.
FOR TEMPS...WILL SEE A FEW DEGREES OF COOLING TUESDAY OVER TODAYS
HIGHS AS COOLER AIR MASS MOVES IN...WITH DRYING OF THE ATMOSPHERIC
COLUMN.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
REGION SHOULD START OUT DRY AS SURFACE HIGH PRESSURE TRIES TO TAKE
CONTROL OF THE WEATHER ACROSS THE AREA. HOWEVER...SEVERAL UPPER
LEVEL DISTURBANCES WILL MOVE EAST. THESE FEATURES MAY RESULT IN A
FEW SHOWERS WEDNESDAY NIGHT INTO EARLY THURSDAY. IN RESPONSE...HAVE
INCLUDED SLIGHT CHANCE POPS.
DRY CONDITIONS SHOULD THEN RETURN AS THE LAST OF THE DISTURBANCES
MOVE EAST.
MODELS SUGGEST A COLD FRONT WILL APPROACH THE AREA FROM THE NORTH ON
FRIDAY. LITTLE MOISTURE IS FORECAST WITH THIS FEATURE. SO OTHER
THAN A FEW MORE CLOUDS...EXPECT DRY WEATHER FOR FRIDAY.
HIGH TEMPERATURES ON WEDNESDAY AND THURSDAY WILL BE QUITE COOL.
TEMPERATURES ON FRIDAY WILL BE A LITTLE WARMER...WITH READINGS
CLOSER TO SEASONAL AVERAGES. GENERALLY WENT WITH A BLEND OF MET/MAV
NUMBERS...AND THEN THE MEX/ECMWF NUMBERS FOR THE LATTER PART OF THE
PERIOD.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
A HIGH BEGINS TO BUILD IN THE GULF OF MEXICO ON SUNDAY...MIGRATES
EAST AND TRIES TO STRENGTHEN. THIS WILL LEAD TO A POTENTIALLY
MESSY FORECAST FOR THE OHIO VALLEY WITH SEVERAL UPPER LEVEL
DISTURBANCES ROTATING AROUND THE CANADIAN LOW PRESSURE SYSTEMS.
HAVE CHANCE POPS ON SUNDAY AND MONDAY AS EXPECT MOISTURE TO BECOME
TRAPPED UNDER THE HIGH. THERE REALLY ISN/T ANYTHING SIGNIFICANT TO
FOCUS ON TO TIME THESE EVENTS.
WENT WITH A BLEND OF GUIDANCE FOR TEMPERATURES. TEMPERATURES WILL
RISE THROUGH THE EXTENDED PART OF THE FORECAST.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
SATELLITE IMAGES SHOW AN AREA OF CLEAR SKIES BETWEEN THE BATCH OF
SHOWERS CROSSING THE EASTERN MOUNTAINS ATTM AND THE COLD FRONT
CURRENTLY OVER CENTRAL OH. WITH DEWPOINTS IN THE MID 60S...THIS AREA OF
CLEARING COULD ALLOW RADIATIONAL COOLING TO REACH SATURATION FOR
FOG OR LOW STRATUS FORMATION OVERNIGHT. THEREFORE...CODED IFR
CEILINGS AT CKB...EKN AND HTS WHERE DEWPOINT DEPRESSION IS ALREADY
ZERO. OTHER SITES COULD EXPERIENCE MVFR CEILINGS OR VISIBILITIES
OVERNIGHT.
THE COLD FRONT IS EXPECTED TO REACH SOUTHEAST OH AROUND 12Z THIS
MORNING. SOME LOW STRATUS CLOUDS CAN BE EXPECTED ALONG ITS PATH
WITH NO PCPN. THE MORNING STRATUS WILL THEN MIX HIGHER BEFORE
MIXING OUT ALTOGETHER BY MID MORNING.
CALM FLOW EXPECTED AT MOST SITES OVERNIGHT...BECOMING LIGHT W TO
NW ON TUESDAY. IT MAY STRENGTHEN AND BECOME JUST A BIT GUSTY TUE
AFTERNOON.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: FOG AND STRATUS FORMATION OVERNIGHT AND BREAK
UP TUE MORNING MAY VARY. THERE MAY BE MORE IFR THAN FCST ON
EITHER...ESPECIALLY E OF THE OHIO RIVER.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE TUE 05/19/15
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
CRW CONSISTENCY M M M M M H H H H H M H
HTS CONSISTENCY M M M M M M M M M M M H
BKW CONSISTENCY M M H H M M M H H H H H
EKN CONSISTENCY M H M L M L L L H H H H
PKB CONSISTENCY H H M M M M M M M M M H
CKB CONSISTENCY M M M H H H H H H H H H
AFTER 06Z WEDNESDAY...
FOG/LOW CLOUDS POSSIBLE OVERNIGHT TUE NT INTO WED MORNING AND
POSSIBLY AGAIN OVERNIGHT THU NT INTO FRI MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JSH/ARJ
NEAR TERM...ARJ/TRM
SHORT TERM...JSH
LONG TERM...FB
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS TULSA OK
925 PM CDT WED MAY 20 2015
...UPDATE...
.DISCUSSION...
CLOUDY AND COOL POST-FRONTAL CONDITIONS ACROSS
THE FORECAST AREA THROUGH TONIGHT. AREA RADARS
ARE SHOWING ISOLATED SHOWERS/THUNDERSTORMS
ACROSS SRN OK...AND HAVE UPPED POPS FOR PARTS
OF SE OK AFTER 06Z AND INTO THURSDAY MORNING
BASED ON LATEST HRRR OUTPUT. ALSO BUMPED UP
CLOUD COVER AS WELL.
STILL EXPECTING SEVERAL ROUNDS OF POTENTIALLY
HEAVY PRECIPITATION OVER THE NEXT SEVERAL
DAYS...THE FIRST COMING ON FRIDAY. CONTEMPLATED
ISSUING A FLASH FLOOD WATCH...BUT WILL DEFER
TO THE NEXT SHIFT FOR NOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 50 68 53 63 / 10 10 20 80
FSM 56 70 56 65 / 10 10 10 50
MLC 55 68 56 63 / 20 10 30 60
BVO 49 67 51 63 / 10 10 20 80
FYV 49 65 49 62 / 10 10 10 40
BYV 48 63 48 62 / 10 10 10 30
MKO 52 67 54 63 / 10 10 20 70
MIO 48 65 49 64 / 10 10 10 50
F10 52 67 55 61 / 10 10 20 70
HHW 58 72 58 68 / 30 30 40 50
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...18
AREA FORECAST DISCUSSION
NWS MEDFORD OR
901 PM PDT MON MAY 18 2015
.DISCUSSION...THE FORECAST WAS UPDATED TO ADJUST THE PROBABILITY
OF PRECIPITATION AND PRECIPITATION AMOUNTS FORECAST FOR TONIGHT
THROUGH TUESDAY NIGHT...MAINLY TO SHAVE BACK THE AMOUNTS EXPECTED
FROM THE COAST INTO WESTERN AND CENTRAL DOUGLAS COUNTY AND ALSO
OVER LAKE COUNTY. THESE CHANGES ARE IN ACCORDANCE WITH THE 18Z GFS
AND RECENTLY ARRIVED 00Z NAM DATA.
COMPARED TO YESTERDAY AFTERNOON AND EVENING, SHOWERS WERE MORE
NUMEROUS BUT THUNDERSTORMS WERE LESS NUMEROUS. THE LARGE MAJORITY
OF THE THUNDERSTORMS OCCURRED BETWEEN 1 PM AND 4PM WITH ABOUT 135
LIGHTNING STRIKES COMPARED TO THE MORE THAN 300 YESTERDAY. SLOW
MOVING AND VERY MOIST SHOWERS ARE STILL MOST WIDESPREAD OVER THE
SISKIYOU MOUNTAINS AND HIGHER TERRAIN OF SISKIYOU COUNTY. SEVERAL
RAWS SITES IN THAT AREA HAVE RECEIVED AROUND 0.25 TO 0.60 INCHES
OF RAIN.
ANOTHER FEW BOLTS OF LIGHTNING ARE POSSIBLE DURING THE REMAINDER
OF THE EVENING, BUT ACTIVITY IS WANING WITH THE DECREASE IN
INSTABILITY DUE TO SURFACE COOLING. BUT, A SHORTWAVE ROTATING FROM
NORTHEAST TO SOUTHWEST ACROSS OUR AREA WILL CONTINUE SCATTERED TO
NUMEROUS SHOWERS OVERNIGHT INTO TUESDAY MORNING. THE THUNDERSTORM
FORECAST FOR TUESDAY AFTERNOON AND EVENING LOOKS ON TRACK...WITH
THE THREAT FARTHER EAST THAN IT WAS TODAY...SOUTH AND EAST OF THE
ROGUE VALLEY...DUE TO THE UPPER TROUGH TRACKING FARTHER EAST INTO
THE GREAT BASIN.
THE PATTERN STILL LOOKS TO REMAIN SIMILARLY ACTIVE WITH OCCASIONAL
SHOWERS...MOST NUMEROUS AND MAINLY OVER THE HIGHER TERRAIN DURING
THE AFTERNOON AND EVENING HOURS THROUGH FRIDAY. AT THIS EARLY
JUNCTURE, MODEL DIFFERENCES ARE SUBSTANTIAL REGARDING THE HOLIDAY
WEEKEND FORECAST. BUT, THE PROBABILITIES ARE SHADED TOWARDS A
WARMER AND DRIER PATTERN.
&&
.AVIATION...FOR THE 19/00Z TAF CYCLE...CURRENT RADAR IMAGERY SHOWS
MORE SHOWERS THAN THUNDERSTORMS ACROSS THE CWA. LOOK FOR THE
POTENTIAL FOR THUNDERSTORMS TO DIMINISH THIS EVENING. RIGHT NOW VFR
CIGS ARE STILL PREVAILING, YET MVFR CIGS SHOULD DEVELOP LATER
TONIGHT INTO TUESDAY MORNING UNDER A STABLE AIR MASS WITH PLENTY OF
LOW LEVEL MOISTURE. VFR AND BKN TO OVC DECKS WILL CONTINUE TOMORROW
WITH PLENTY OF MISTURE MOISTURE AND VERTICAL MOTION. /CS
&&
.MARINE...UPDATED 200 PM PDT, MONDAY 18 MAY 2015...A PATTERN OF WEAK
HIGH PRESSURE OFFSHORE AND WEAK LOW PRESSURE INLAND WILL PERSIST
MOST OF THIS WEEK WITH LIGHT TO MODERATE NORTH WINDS AND NORTHWEST
SWELL OVER THE WATERS. WINDS WILL APPROACH SMALL CRAFT ADVISORY
LEVELS ON TUESDAY EVENING AND WEDNESDAY MORNING SOUTH OF CAPE
BLANCO. AFTER THIS NORTH WINDS AROUND 10-20 KTS WILL CONTINUE INTO
THWE WEEKEND. /CS
&&
.PREV DISCUSSION... /ISSUED 521 PM PDT MON MAY 18 2015/
SHORT TERM...MOISTURE CONTINUES TO ROTATE IN OVER OUR AREA FROM
THE EAST AS AN UPPER LOW MOVES INTO THE GREAT BASIN. DYNAMICS ARE
WEAK, BUT THERE IS PLENTY OF INSTABILITY PRESENT FROM THE CASCADE
CREST AND SISKIYOUS EASTWARD, AND NUMEROUS SHOWERS AND ISOLATED
THUNDERSTORMS HAVE ALREADY DEVELOPED. THIS CONVECTION WILL
INCREASE IN COVERAGE AND MIGRATE TOWARD THE WEST THROUGH THE
AFTERNOON. CONVECTION IS ALREADY TRYING TO SPILL OVER ONTO THE
WEST SIDE, BUT IT IS BEING INHIBITED BY THE LITTLE REMAINING CAP.
THE SUN IS PEAKING THROUGH IN THE WEST SIDE VALLEYS AND THE
SURFACE HEATING WILL BREAK THE CAP PRETTY SOON. MESOANALYSIS
INDICATES WE`VE BUILT 500-1000 J/KG OF SURFACE BASED CAPE
OVER JACKSON AND JOSEPHINE COUNTIES ALREADY, WHICH SHOULD BE
RELEASED EVENTUALLY, AND RESULT IN SHOWERS AND THUNDERSTORMS THERE
AS WELL. LATEST RAP AND HRRR GUIDANCE ACTUALLY SHOWS QUITE A LOT
OF CONVECTION OVER THE ROGUE AND ILLINOIS VALLEYS LATER THIS
AFTERNOON. THEY MAY BE A BIT OVERDONE, BUT PEOPLE IN THESE AREAS
SHOULD KEEP AN EYE ON THE SKY. AS OPPOSED TO YESTERDAY, THE SUN IS
ALSO POKING OUT IN THE UMPQUA, AND THEY DO STAND A BETTER CHANCE
OF SEEING SOME THUNDERSTORMS THIS AFTERNOON AS WELL. THERE IS A
LOT OF MOISTURE IN THE PROFILE (PRECIPITABLE WATER IS NEAR AN
INCH) AND THUS ANY OF THESE STORMS WILL BE CAPABLE OF PRODUCING
SMALL HAIL AND HEAVY DOWNPOURS. WITH LITTLE WIND ALOFT TO SPEAK
OF, STRONG WINDS SHOULDN`T BE MUCH OF A CONCERN, BUT WE COULD SEE
GUSTY WINDS AROUND STORMS.
THINGS WILL STABILIZE TONIGHT AS THE BOUNDARY LAYER COOLS, BUT
SHOWERS ARE LIKELY TO CONTINUE OVERNIGHT ALONG THE MOUNTAINS AND
EAST SIDE. AS BROAD TROUGHING REMAINS OVER THE REGION, WE EXPECT
TO REPEAT THIS BASIC DIURNAL PATTERN OF NIGHT TIME SHOWERS AND
MORE WIDESPREAD SHOWERS AND THUNDERSTORMS IN THE AFTERNOONS
TOMORROW THROUGH THURSDAY. WE SHOULD GRADUALLY BECOME MORE STABLE
ON THE WEST SIDE, SO THUNDERSTORMS BECOME LESS OF AN ISSUE. ONE
BIGGER CHANGE I MADE WAS TO INCREASE POPS OVER THE WEST SIDE
TUESDAY NIGHT INTO WEDNESDAY MORNING AS ALL THE MODELS ARE SHOWING
A DEFORMATION BAND FORMING OVER THE AREA. -WRIGHT
LONG TERM...THE MODELS SHOW THE WEAK UPPER LOW MOVING INTO
ARIZONA WITH WEAK RIDGING BUILDING OFFSHORE. THE GFS SHOWS MORE
RIDGING COMPARED TO THE EC AND BOTH CONTINUE TO SHOW QPF OVER MOST
OF THE AREA. I SUSPECT THE QPF MAY BE OVERDONE NOT ONLY WITH
AMOUNTS, BUT ALSO THE COVERAGE. THUS HAVE SCALED BACK ON POPS FOR
FRIDAY. ANOTHER WEAK UPPER LOW MOVES INTO THE AREA SATURDAY, BUT
THIS ONE WILL BE COMING IN FROM THE NORTHWEST AND IS NOT EXPECTED
TO HAVE ANY OVER WATER TRAJECTORY, THEREFORE MOISTURE WILL BE
LIMITED AND ANY SHOWERS SHOULD BE ISOLATED AND EAST OF THE
CASCADES. THE EC AND GFS DISAGREE WITH THE PROGRESSION OF THE
UPPER LOW SUNDAY AND THE UPSTREAM UPPER LOW. THE GFS KEEPS THE
UPPER LOW OVER THE AREA SUNDAY WHILE THE EC MOVES IT INTO NORTHERN
CAL. FOR NOW WE`LL GO WITH A BLEND BETWEEN THE TWO AND KEEP A
SLIGHT CHANCE OF SHOWERS EAST OF THE CASCADES. THE ENSEMBLE MEAN
SHOWS A LARGE SPREAD IN THIS TIME PERIOD WHICH YIELDS LOWER
CONFIDENCE IN THE FORECAST. -PETRUCELLI
FIRE WEATHER...UPDATED 200 PM PDT, MONDAY 18 MAY 2015...AN UPPER
LOW CENTERED JUST EAST OF THE BAY AREA IS SENDING MOISTURE NORTHEAST
TOWARDS THE AREA. SO FAR ISOLATED STORMS HAVE BEEN CONFINED TO THE
CASCADES EAST, BUT THEY ARE EXPECTED TO BECOME MORE FREQUENT AS THE
AFTERNOON PROGRESSES INTO THIS EVENING. THE LATEST MESOSCALE ANALYSIS
SHOWS HIGHER CAPE VALUES WEST OF THE CASCADES COMPARED TO YESTERDAY
AND THE MOIST LAYER IS MUCH DEEPER ALL THE WAY UP TO 400 MB BASED IN
THIS MORNINGS SOUNDING. THE 700 MB FLOW WILL BE FROM THE EAST TO
NORTHEAST, THERE IS A BETTER CHANCE FOR SHOWERS AND ISOLATED STORMS
TO MAKE THEIR WAY WEST OF THE CASCADES. WITH PLENTY OF MOISTURE
AVAILABLE, THUNDERSTORMS ARE LIKELY TO BE RAIN PRODUCERS AND THEY
WILL BE SLOW MOVERS. SO HEAVY RAINFALL IS POSSIBLE.
THUNDERSTORMS WILL DECREASE THIS EVENING AND END TONIGHT, BUT WE`LL
CONTINUE TO GET MUCH NEEDED RAIN SHOWERS OVERNIGHT TONIGHT.
THE UPPER LOW WILL MOVE EAST AND WEAKEN TUESDAY WITH THE BEST CHANCE
FOR THUNDERSTORMS ALONG AND EAST OF THE CASCADES. THE ATMOSPHERE IS
EXPECTED TO BE MORE STABLE WEST OF THE CASCADES DUE TO A MARINE
INFLUENCE, SO WERE ONLY EXPECTING SHOWERS. -PETRUCELLI
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...NONE.
$$
DW/MAP/CZS
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
531 PM EDT TUE MAY 19 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS CENTRAL PENNSYLVANIA TODAY WITH A
MARGINAL/ISOLATED SEVERE WEATHER RISK FROM THE EASTERN COAL REGION
INTO THE POCONOS. A COOLER AND MAINLY DRY WEATHER PATTERN WITH
NEAR TO BELOW NORMAL TEMPERATURES WILL GRIP THE REGION FROM
WEDNESDAY INTO THE WEEKEND...FOLLOWED BY A GRADUAL WARMING TREND
WITH UNSETTLED CONDITIONS THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
WINDS NOW GUSTY WITH MIXING FAIRLY DEEP IN THE CENTRAL MTNS WHERE
SUN HAS BEEN OUT LONGEST. ML CAPES ABOVE 500 THERE NOW. COLD
FRONT ONLY THROUGH ABOUT 5 COUNTIES AT THIS POINT AND TAKING IT/S
TIME. CAPES RISING IN THE SUSQ VALLEY WHERE DEWPOINTS ARE STILL
VERY HIGH. OLD BOUNDARY LYING OVER OR EVEN JUST TO THE WEST OF THE
MAIN STEM SUSQ RIVER AT 1 PM. HRRR AND RUC ARE IN AGREEMENT THAT
SHRA AND WIDELY SCT TSRA WILL FORM IN THE EASTERN COUNTIES IN THE
MIDDLE OF THE AFTERNOON...BUT TAKE UNTIL SUNSET FOR ALL OF THEM TO
GET TO THE EAST OF THE CWA. WINDS ALOFT WILL HELP MOVE THESE SCT
SHRA ALONG AND FLOODING WORRIES VERY LOW.
AS THE SUN SETS AND SHOWERS EXIT/WANE CONCURRENTLY...THE REST OF
THE AREA SHOULD BE MAINLY CLEAR. BUT THE LOWER CLOUDS OVER THE
UPPER GREAT LAKES WILL BEGIN TO SLIDE INTO THE NW. THESE CLOUDS
WILL TRY TO COVER THE NWRN HALF OF THE AREA. SCT CLOUDS MAY MAKE
IT DOWN THE HILLS INTO THE SE BY THE END OF THE NIGHT BUT THE
DOWNSLOPE WILL HELP TO DRY THEM UP. CLOUDS IN THE NW WILL HELP
KEEP TEMPS UP IN THE U30S ON THE NW PLATEAU AND OTHER AREAS WILL
FALL TO THE 40S AND L50S. URBAN AREAS IN THE SE MAY HOLD NEAR 55F
DESPITE THE CLEAR SKY DUE TO THE WINDS STAYING UP FOR MOST/ALL OF
THE NIGHT AND KEEPING THE BLYR WELL-MIXED.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
PRESSURE RISES AND SUBSIDENCE MOVES IN FROM THE NW BUT WINDS WILL
STILL BE NW AND RATHER GUSTY DURING THE DAY ON WED AS CENTER OF
SFC HIGH STAYS WELL TO THE WEST. MIXING SHOULD ALLOW GUSTS INTO
THE 20S OR EVEN NEAR 30 MPH. MAXES WILL BE MUCH COOLER THAN
TUES...BUT THE MID/LATE MAY SUN/HEATING WILL ALLOW US TO MIX WELL
ABOVE 8H TEMPS. SO EVEN THOUGH MORNING 8H TEMPS WILL BE -2C IN THE
NRN TIER AND ONLY +2C IN THE SRN TIER...WE SHOULD STILL GET BACK
TO THE M50S N AND NEAR 70F IN THE SERN CITIES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
THE MODELS SHOW A SHORTWAVE TROUGH MOVING QUICKLY ESEWD FROM THE
UPPER GREAT LAKES THROUGH THE CENTRAL APPALACHIANS AND NORTHERN
MID ATLANTIC STATES THU-FRI WITH PLENTY OF CLOUDS AND SOME
SHOWERS POSSIBLE ON THU. A WEAK SFC LOW IS FCST TO EMERGE OFF THE
CAROLINAS INTO FRIDAY WITH SOME SPREAD IN THE GUIDANCE...OWING TO
VARIABILITY IN THE HANDLING OF THE PARENT SHORTWAVE. A SECONDARY
COLD FRONT SHOULD CROSS THE AREA ON FRIDAY FOLLOWED BY A
REINFORCING SHOT OF COOL AIR. CONFIDENCE REMAINS ON THE LOW SIDE
FOR FROST THU MORNING IN THE NORTH AS THE PATTERN DOES NOT LOOK
FAVORABLE OR CONDUCIVE.
CONFIDENCE IN FROST POTENTIAL IS MUCH HIGHER ON SATURDAY MORNING
OVER THE NORTH-CNTRL ZONES WITH A LARGE AREA OF HIGH PRESSURE
FCST TO SETTLE OVER CENTRAL PA. MAINTAINED FROST WORDING IN SOME
NORTHERN ZONES. DRY WX SHOULD HOLD ON UNTIL EARLY NEXT WEEK AS
THE UPPER RIDGE BUILDS AGAIN OVER THE ERN U.S.
AN E-W FRONTAL BOUNDARY LOOKS TO BECOME A FOCUS FOR PCPN MON-TUE
AS IT PIVOTS AND LIFTS NWD IN A SIMILAR FASHION TO THIS PAST
WEEKEND. ALL GUIDANCE POINTS TO A GRADUAL WARMING TREND OVER THE
WEEKEND...WITH EVEN MILDER AND MORE MUGGY CONDITIONS STARTING
MEMORIAL DAY AND CONTINUING INTO NEXT WEEK.
&&
.AVIATION /22Z TUESDAY THROUGH SUNDAY/...
THE COLD FRONT HAS CLEARED MY EASTERN ZONES LEAVING BEHIND VFR
CONDITIONS AND A GUSTY WNW WIND.
MOST OF THE REGION WILL REMAIN VFR INTO WEDNESDAY...WITH THE
POSSIBLE EXCEPTION OF HIGHER ELEVATIONS FROM JOHNSTOWN INTO THE
NORTHERN MOUNTAINS WHERE CEILINGS MAY DROP INTO THE MVFR CATEGORY
FOR A TIME LATER TONIGHT THROUGH MID MORNING TOMORROW.
OUTLOOK...
WED-FRI...NO SIG WX.
SUN...MAINLY VFR...MVFR POSS IN SHRA/TSRA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...RXR/STEINBUGL
AVIATION...DANGELO/LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
400 PM EDT TUE MAY 19 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS CENTRAL PENNSYLVANIA TODAY WITH A
MARGINAL/ISOLATED SEVERE WEATHER RISK FROM THE EASTERN COAL REGION
INTO THE POCONOS. A COOLER AND MAINLY DRY WEATHER PATTERN WITH
NEAR TO BELOW NORMAL TEMPERATURES WILL GRIP THE REGION FROM
WEDNESDAY INTO THE WEEKEND...FOLLOWED BY A GRADUAL WARMING TREND
WITH UNSETTLED CONDITIONS THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
WINDS NOW GUSTY WITH MIXING FAIRLY DEEP IN THE CENTRAL MTNS WHERE
SUN HAS BEEN OUT LONGEST. ML CAPES ABOVE 500 THERE NOW. COLD
FRONT ONLY THROUGH ABOUT 5 COUNTIES AT THIS POINT AND TAKING IT/S
TIME. CAPES RISING IN THE SUSQ VALLEY WHERE DEPOINTS ARE STILL
VERY HIGH. OLD BOUNDARY LYING OVER OR EVEN JUST TO THE WEST OF THE
MAIN STEM SUSQ RIVER AT 1 PM. HRRR AND RUC ARE IN AGREEMENT THAT
SHRA AND WIDELY SCT TSRA WILL FORM IN THE EASTERN COUNTIES IN THE
MIDDLE OF THE AFTERNOON...BUT TAKE UNTIL SUNSET FOR ALL OF THEM TO
GET TO THE EAST OF THE CWA. WINDS ALOFT WILL HELP MOVE THESE SCT
SHRA ALONG AND FLOODING WORRIES VERY LOW.
AS THE SUN SETS AND SHOWERS EXIT/WANE CONCURRENTLY...THE REST OF
THE AREA SHOULD BE MAINLY CLEAR. BUT THE LOWER CLOUDS OVER THE
UPPER GREAT LAKES WILL BEGIN TO SLIDE INTO THE NW. THESE CLOUDS
WILL TRY TO COVER THE NWRN HALF OF THE AREA. SCT CLOUDS MAY MAKE
IT DOWN THE HILLS INTO THE SE BY THE END OF THE NIGHT BUT THE
DOWNSLOPE WILL HELP TO DRY THEM UP. CLOUDS IN THE NW WILL HELP
KEEP TEMPS UP IN THE U30S ON THE NW PLATEAU AND OTHER AREAS WILL
FALL TO THE 40S AND L50S. URBAN AREAS IN THE SE MAY HOLD NEAR 55F
DESPITE THE CLEAR SKIY DUE TO THE WINDS STAYING UP FOR MOST/ALL
OF THE NIGHT AND KEEPING THE BLYR WELL-MIXED.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
PRESSURE RISES AND SUBSIDENCE MOVES IN FROM THE NW BUT WINDS WILL
STILL BE NW AND RATHER GUSTY DURING THE DAY ON WED AS CENTER OF
SFC HIGH STAYS WELL TO THE WEST. MIXING SHOULD ALLOW GUSTS INTO
THE 20S OR EVEN NEAR 30 MPH. MAXES WILL BE MUCH COOLER THAN
TUES...BUT THE MID/LATE MAY SUN/HEATING WILL ALLOW US TO MIX WELL
ABOVE 8H TEMPS. SO EVEN THOUGH MORNING 8H TEMPS WILL BE -2C IN THE
NRN TIER AND ONLY +2C IN THE SRN TIER...WE SHOULD STILL GET BACK
TO THE M50S N AND NEAR 70F IN THE SERN CITIES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
THE MODELS SHOW A SHORTWAVE TROUGH MOVING QUICKLY ESEWD FROM THE
UPPER GREAT LAKES THROUGH THE CENTRAL APPALACHIANS AND NORTHERN
MID ATLANTIC STATES THU-FRI WITH PLENTY OF CLOUDS AND SOME
SHOWERS POSSIBLE ON THU. A WEAK SFC LOW IS FCST TO EMERGE OFF THE
CAROLINAS INTO FRIDAY WITH SOME SPREAD IN THE GUIDANCE...OWING TO
VARIABILITY IN THE HANDLING OF THE PARENT SHORTWAVE. A SECONDARY
COLD FRONT SHOULD CROSS THE AREA ON FRIDAY FOLLOWED BY A
REINFORCING SHOT OF COOL AIR. CONFIDENCE REMAINS ON THE LOW SIDE
FOR FROST THU MORNING IN THE NORTH AS THE PATTERN DOES NOT LOOK
FAVORABLE OR CONDUCIVE.
CONFIDENCE IN FROST POTENTIAL IS MUCH HIGHER ON SATURDAY MORNING
OVER THE NORTH-CNTRL ZONES WITH A LARGE AREA OF HIGH PRESSURE
FCST TO SETTLE OVER CENTRAL PA. MAINTAINED FROST WORDING IN SOME
NORTHERN ZONES. DRY WX SHOULD HOLD ON UNTL EARLY NEXT WEEK AS THE
UPPER RIDGE BUILDS AGAIN OVER THE ERN U.S.
AN E-W FRONTAL BOUNDARY LOOKS TO BECOME A FOCUS FOR PCPN MON-TUE
AS IT PIVOTS AND LIFTS NWD IN A SIMILAR FASHION TO THIS PAST
WEEKEND. ALL GUIDANCE POINTS TO A GRADUAL WARMING TREND OVER THE
WEEKEND...WITH EVEN MILDER AND MORE MUGGY CONDITIONS STARTING
MEMORIAL DAY AND CONTINUING INTO NEXT WEEK.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
COLD FRONT MOVING RATHER SLOWLY THIS AFTN. IT MAY NOT CLEAR LNS
BEFORE 00Z. THUS...SHOWERS AND SCT THUNDERSTORMS ARE EXPECTED TO
DEVELOP - MAINLY ALONG AND TO THE EAST OF IPT AND MDT. HIGH
PRESSURE THEN MOVES IN. BUT CLOUD DECK UNDER UPPER LOW WILL SLIDE
ACROSS THE AREA FROM NW-SE LATER THIS EVENING AND OVERNIGHT.
SOME STRATUS CLOUDS WILL LINGER INTO THE MORNING...BUT BREAK UP
AND LIFT TO JUST HARMLESS CU. CIGS SHOULD REMAIN MVFR
TONIGHT...BUT COULD DIP TO IFR AT BFD AND JST. WILL LEAVE THEM
LOWER-END MVFR FOR NOW.
OUTLOOK...
WED...NO SIG WX.
WED NIGHT-THURS...MAINLY VFR. SHRA POSS ESP S.
THURS NIGHT-FRI...NO SIG WX.
SUN...MAINLY VFR...MVFR POSS IN SHRA/TSRA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...RXR/STEINBUGL
AVIATION...DANGELO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
113 PM EDT TUE MAY 19 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS CENTRAL PENNSYLVANIA TODAY WITH A
MARGINAL/ISOLATED SEVERE WEATHER RISK FROM THE EASTERN COAL REGION
INTO THE POCONOS. A COOLER AND MAINLY DRY WEATHER PATTERN WITH
NEAR TO BELOW NORMAL TEMPERATURES WILL GRIP THE REGION FROM
WEDNESDAY INTO THE WEEKEND...FOLLOWED BY A GRADUAL WARMING TREND
WITH UNSETTLED CONDITIONS THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
WINDS NOW GUSTY WITH MIXING FAIRLY DEEP IN THE CENTRAL MTNS WHERE
SUN HAS BEEN OUT LONGEST. ML CAPES ABOVE 500 THERE NOW. COLD
FRONT ONLY THROUGH ABOUT 5 COUNTIES AT THIS POINT AND TAKING IT/S
TIME. CAPES RISING IN THE SUSQ VALLEY WHERE DEPOINTS ARE STILL
VERY HIGH. OLD BOUNDARY LYING OVER OR EVEN JUST TO THE WEST OF THE
MAIN STEM SUSQ RIVER AT 1 PM. HRRR AND RUC ARE IN AGREEMENT THAT
SHRA AND WIDELY SCT TSRA WILL FORM IN THE EASTERN COUNTIES IN THE
MIDDLE OF THE AFTERNOON...BUT TAKE UNTIL SUNSET FOR ALL OF THEM TO
GET TO THE EAST OF THE CWA. WINDS ALOFT WILL HELP MOVE THESE SCT
SHRA ALONG AND FLOODING WORRIES VERY LOW.
AS THE SUN SETS AND SHOWERS EXIT/WANE CONCURRENTLY...THE REST OF
THE AREA SHOULD BE MAINLY CLEAR. BUT THE LOWER CLOUDS OVER THE
UPPER GREAT LAKES WILL BEGIN TO SLIDE INTO THE NW. THESE CLOUDS
WILL TRY TO COVER THE NWRN HALF OF THE AREA. SCT CLOUDS MAY MAKE
IT DOWN THE HILLS INTO THE SE BY THE END OF THE NIGHT BUT THE
DOWNSLOPE WILL HELP TO DRY THEM UP. CLOUDS IN THE NW WILL HELP
KEEP TEMPS UP IN THE U30S ON THE NW PLATEAU AND OTHER AREAS WILL
FALL TO THE 40S AND L50S. URBAN AREAS IN THE SE MAY HOLD NEAR 55F
DESPITE THE CLEAR SKIY DUE TO THE WINDS STAYING UP FOR MOST/ALL
OF THE NIGHT AND KEEPING THE BLYR WELL-MIXED.
&&
.SHORT TERM /WEDNESDAY/...
PRESSURE RISES AND SUBSIDENCE MOVES IN FROM THE NW BUT WINDS WILL
STILL BE NW AND RATHER GUSTY DURING THE DAY ON WED AS CENTER OF
SFC HIGH STAYS WELL TO THE WEST. MIXING SHOULD ALLOW GUSTS INTO
THE 20S OR EVEN NEAR 30 MPH. MAXES WILL BE MUCH COOLER THAN
TUES...BUT THE MID/LATE MAY SUN/HEATING WILL ALLOW US TO MIX WELL
ABOVE 8H TEMPS. SO EVEN THOUGH MORNING 8H TEMPS WILL BE -2C IN THE
NRN TIER AND ONLY +2C IN THE SRN TIER...WE SHOULD STILL GET BACK
TO THE M50S N AND NEAR 70F IN THE SERN CITIES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
THE MODELS SHOW A SHORTWAVE TROUGH MOVING QUICKLY ESEWD FROM THE
UPPER GREAT LAKES THROUGH CENTRAL APPALACHIANS AND NORTHERN MID
ATLANTIC STATES THU-FRI WITH SOME SHOWERS POSSIBLE ON THU. A SFC
LOW IS FCST TO EMERGE OFF THE CAROLINAS INTO FRIDAY WITH SOME
SPREAD IN THE GUIDANCE...OWING TO VARIABILITY IN THE HANDLING OF
THE PARENT SHORTWAVE. A SECONDARY COLD FRONT SHOULD CROSS THE AREA
ON FRIDAY FOLLOWED BY ANOTHER SHOT OF COOL AIR. CONFIDENCE REMAINS
ON THE LOW SIDE FOR FROST THU MORNING IN THE NORTH AS THE PATTERN
DOES NOT LOOK FAVORABLE OR CONDUCIVE.
CONFIDENCE IN FROST POTENTIAL IS MUCH HIGHER ON SATURDAY MORNING
OVER THE NORTH-CNTRL ZONES WITH A LARGE AREA OF HP FCST TO SETTLE
OVER CENTRAL PA. WILL ADD FROST WORDING TO THE HWO FOR THE 3 ZONES
THAT ARE STILL NOT IN THE GROWING SEASON /MCKEAN-POTTER-ELK/. DRY
WX SHOULD HOLD ON UNTL EARLY NEXT WEEK AS THE UPPER RIDGE BUILDS
AGAIN OVER THE ERN U.S. AN E-W FRONTAL BOUNDARY COULD BE A FOCUS
FOR PCPN AS IT PIVOTS AND LIFTS NWD IN A SIMILAR FASHION TO THIS
PAST WEEKEND. CLOSELY FOLLOWED THE ROBUST NATIONAL SUPERBLEND
PROTOTYPE GUIDANCE FOR TEMPERATURES WHICH FAVORS A GRADUAL
WARMING TREND FOR THE AREA BEYOND THE END OF THE PERIOD.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
COLD FRONT MOVING RATHER SLOWLY THIS AFTN. IT MAY NOT CLEAR LNS
BEFORE 00Z. THUS...SHOWERS AND SCT THUNDERSTORMS ARE EXPECTED TO
DEVELOP - MAINLY ALONG AND TO THE EAST OF IPT AND MDT. HIGH
PRESSURE THEN MOVES IN. BUT CLOUD DECK UNDER UPPER LOW WILL SLIDE
ACROSS THE AREA FROM NW-SE LATER THIS EVENING AND OVERNIGHT.
SOME STRATUS CLOUDS WILL LINGER INTO THE MORNING...BUT BREAK UP
AND LIFT TO JUST HARMLESS CU. CIGS SHOULD REMAIN MVFR
TONIGHT...BUT COULD DIP TO IFR AT BFD AND JST. WILL LEAVE THEM
LOWER-END MVFR FOR NOW.
OUTLOOK...
WED...NO SIG WX.
WED NIGHT-THURS...MAINLY VFR. SHRA POSS ESP S.
THURS NIGHT-FRI...NO SIG WX.
SUN...MAINLY VFR...MVFR POSS IN SHRA/TSRA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...STEINBUGL
AVIATION...DANGELO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
831 AM EDT TUE MAY 19 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS CENTRAL PENNSYLVANIA TODAY WITH A
MARGINAL/ISOLATED SEVERE WEATHER RISK FROM THE EASTERN COAL REGION
INTO THE POCONOS. A COOLER AND MAINLY DRY WEATHER PATTERN WITH
NEAR TO BELOW NORMAL TEMPERATURES WILL GRIP THE REGION FROM
WEDNESDAY INTO THE WEEKEND...FOLLOWED BY A GRADUAL WARMING TREND
WITH UNSETTLED CONDITIONS THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
815 AM UPDATE...
SHOWERS EXITING TO THE EAST. COLD FRONT BARELY TO THE WEST OF BFD
AND PIT...MOVING SLOWLY BUT STEADILY. THE FRONT WILL BE HALF WAY
THROUGH THE CWA AROUND NOON BUT TAKE ALL AFTERNOON AND MAYBE UNTIL
EARLY EVENING DAY TO GET TOTALLY OUT OF THE CWA. HIGH MOISTURE IN
THE EAST AND ALL DAY TO COOK/MIX WILL MAKE THE KETTLE BUBBLE WHEN
THE FRONT APPROACHES/PASSES. HAVE DELAYED EXIT OF STORMS FROM
LANCASTER CO BY AN HOUR OR TWO.
PREV...
09Z RADAR SHOWS WHAT IS LEFT OF MEASURABLE SHOWERS MOVG EWD ALONG
RDG-LNS LINE. WILL TAPER DOWN POPS THROUGH MID MORNING BASED ON
RADAR TRENDS AND HRRR. SUBTLE BACKDOOR TYPE FRONT HAS ALLOWED
MARINE AIR/EASTERLY LLVL FLOW TO REACH AS FAR WEST AS THE SUSQ
RIVER WITH WDSPRD LOW CIGS AND FOG EXPECTED TO PERSIST THROUGH
DAYBREAK. TO THE WEST ALONG THE ALLEGHANY FRONT...WEAK BUT MOIST
UPSLOPE IS PROMOTING LOW CIGS AND FOG ALONG THE RT 219 CORRIDOR.
SHORTWAVE CURRENTLY MOVING THROUGH THE UPPER GREAT LAKES WILL
TEAM WITH ADDITIONAL ENERGY DROPPING DOWN AROUND THE HUDSON BAY
UPPER TROUGH TO FLATTEN THE ANOMALOUS RIDGE OVER THE NORTHEASTERN
U.S. ONCE THE LOW CLOUDS/FOG BURN OFF THIS MORNING...STRONG PRE-
FRONTAL BOUNDARY LAYER WARMING SHOULD PROVE MORE THAN ADEQUATE FOR
CONVECTION WITH HRRR SHOWING DEVELOPMENT EAST OF THE SUSQ RIVER
BY 18-19Z. THE SPC DAY 1 MARGINAL RISK JUST CLIPS EAST-CENTRAL PA
FROM THE COAL REGION ENEWD INTO THE POCONOS WITH INCREASING SHEAR
TO THE NORTH. HOWEVER DESPITE WEAKER FLOW ALOFT...CANT RULE OUT
THREAT FOR GUSTY WINDS/SMALL HAIL IN MORE CAPE-DRIVEN STORMS
WITHIN STEEP LLVL LAPSE RATE ENVIRONMENT OVER THE LWR SQV. HEAVY
DOWNPOURS COULD POSE MINOR FLOOD THREAT PROBABLY MORE SO CONFINED
TO URBAN/POOR DRAINAGE AREAS VS. SMALL STREAMS AND CREEKS GIVEN
DRY ANTECEDENT CONDITIONS AND BELOW NORMAL STREAM FLOWS FOR THIS
TIME OF YEAR. ANY EARLY EVENING ACTIVITY OVER FAR ERN SXNS SHOULD
PUSH OUT OF THE CWA AFTER 00Z AS NOTICEABLY DRIER AIR SPREADS
ACROSS THE AREA IN THE WAKE OF THE COLD FRONT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
A COOLER BROAD CYCLONIC FLOW WILL BEGIN TO GRIP THE REGION ON
WEDNESDAY WITH DAYTIME HIGHS SOME 15-20F COOLER THAN TODAY. THE
COOLER AIR ALOFT SHOULD PROMOTE AFTN CU DEVELOPMENT WITH A NW
BREEZE ADDING TO THE RELATIVE CHILL. THE MODELS SHOW A SHORTWAVE
TROUGH MOVING QUICKLY ESEWD FROM THE UPPER GREAT LAKES THROUGH
CENTRAL APPALACHIANS AND NORTHERN MID ATLANTIC STATES THU-FRI WITH
SOME SHOWERS POSSIBLE ON THU. A SFC LOW IS FCST TO EMERGE OFF THE
CAROLINAS INTO FRIDAY WITH SOME SPREAD IN THE GUIDANCE...OWING TO
VARIABILITY IN THE HANDLING OF THE PARENT SHORTWAVE. A SECONDARY
COLD FRONT SHOULD CROSS THE AREA ON FRIDAY FOLLOWED BY ANOTHER
SHOT OF COOL AIR. CONFIDENCE REMAINS ON THE LOW SIDE FOR FROST
THU MORNING IN THE NORTH AS THE PATTERN DOES NOT LOOK FAVORABLE
OR CONDUCIVE.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
CONFIDENCE IN FROST POTENTIAL IS MUCH HIGHER ON SATURDAY MORNING
OVER THE NORTH-CNTRL ZONES WITH A LARGE AREA OF HP FCST TO SETTLE
OVER CENTRAL PA. WILL ADD FROST WORDING TO THE HWO FOR THE 3 ZONES
THAT ARE STILL NOT IN THE GROWING SEASON /MCKEAN-POTTER-ELK/. DRY
WX SHOULD HOLD ON UNTL EARLY NEXT WEEK AS THE UPPER RIDGE BUILDS
AGAIN OVER THE ERN U.S. AN E-W FRONTAL BOUNDARY COULD BE A FOCUS
FOR PCPN AS IT PIVOTS AND LIFTS NWD IN A SIMILAR FASHION TO THIS
PAST WEEKEND. CLOSELY FOLLOWED THE ROBUST NATIONAL SUPERBLEND
PROTOTYPE GUIDANCE FOR TEMPERATURES WHICH FAVORS A GRADUAL
WARMING TREND FOR THE AREA BEYOND THE END OF THE PERIOD.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
PATCHY DENSE FOG AND LOW STRATOCU IS CONTINUING THROUGH THE
EASTERN TAF SITES. EXPECT FOR THIS TO PERSIST OVER THE NEXT FEW
HOURS...LIFTING BETWEEN 13Z TO 15Z. IFR AT BFD AND JST WILL
PERSIST AS WELL AND BY 14Z SHOULD LIFT TO MVFR ADN BY 16Z BE VFR.
THE COLD FRONT IS SLOWLY MOVING EASTWARD AND WILL MOVE THROUGH
THIS AFTERNOON. STILL CAN/T RULE OUT AN ISOLD SHRA/TSRA ACROSS
EASTERN PA ARND MIDDAY WITH PASSAGE OF THE FRONT.
OTHERWISE...EXPECT A RETURN TO WIDESPREAD VFR CONDS...AS A GUSTY
WEST WIND BRINGS MUCH DRIER AIR INTO THE REGION BEHIND THE COLD
FRONT.
GUSTY WINDS SHOULD SUBSIDE BY EARLY EVENING...WITH STRONG
NORTHWESTERLY FLOW INCREASING OVERNIGHT WHICH COULD MIX DOWN
STRONTER WINDS EARLY WEDNESDAY MORNING.
OUTLOOK...
WED-SAT...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...DANGELO/STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...STEINBUGL
AVIATION...FITZGERALD/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
744 AM EDT TUE MAY 19 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS CENTRAL PENNSYLVANIA TODAY WITH A
MARGINAL/ISOLATED SEVERE WEATHER RISK FROM THE EASTERN COAL REGION
INTO THE POCONOS. A COOLER AND MAINLY DRY WEATHER PATTERN WITH
NEAR TO BELOW NORMAL TEMPERATURES WILL GRIP THE REGION FROM
WEDNESDAY INTO THE WEEKEND...FOLLOWED BY A GRADUAL WARMING TREND
WITH UNSETTLED CONDITIONS THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
09Z RADAR SHOWS WHAT IS LEFT OF MEASURABLE SHOWERS MOVG EWD ALONG
RDG-LNS LINE. WILL TAPER DOWN POPS THROUGH MID MORNING BASED ON
RADAR TRENDS AND HRRR. SUBTLE BACKDOOR TYPE FRONT HAS ALLOWED
MARINE AIR/EASTERLY LLVL FLOW TO REACH AS FAR WEST AS THE SUSQ
RIVER WITH WDSPRD LOW CIGS AND FOG EXPECTED TO PERSIST THROUGH
DAYBREAK. TO THE WEST ALONG THE ALLEGHANY FRONT...WEAK BUT MOIST
UPSLOPE IS PROMOTING LOW CIGS AND FOG ALONG THE RT 219 CORRIDOR.
SHORTWAVE CURRENTLY MOVING THROUGH THE UPPER GREAT LAKES WILL
TEAM WITH ADDITIONAL ENERGY DROPPING DOWN AROUND THE HUDSON BAY
UPPER TROUGH TO FLATTEN THE ANOMALOUS RIDGE OVER THE NORTHEASTERN
U.S. ONCE THE LOW CLOUDS/FOG BURN OFF THIS MORNING...STRONG PRE-
FRONTAL BOUNDARY LAYER WARMING SHOULD PROVE MORE THAN ADEQUATE FOR
CONVECTION WITH HRRR SHOWING DEVELOPMENT EAST OF THE SUSQ RIVER
BY 18-19Z. THE SPC DAY 1 MARGINAL RISK JUST CLIPS EAST-CENTRAL PA
FROM THE COAL REGION ENEWD INTO THE POCONOS WITH INCREASING SHEAR
TO THE NORTH. HOWEVER DESPITE WEAKER FLOW ALOFT...CANT RULE OUT
THREAT FOR GUSTY WINDS/SMALL HAIL IN MORE CAPE-DRIVEN STORMS
WITHIN STEEP LLVL LAPSE RATE ENVIRONMENT OVER THE LWR SQV. HEAVY
DOWNPOURS COULD POSE MINOR FLOOD THREAT PROBABLY MORE SO CONFINED
TO URBAN/POOR DRAINAGE AREAS VS. SMALL STREAMS AND CREEKS GIVEN
DRY ANTECEDENT CONDITIONS AND BELOW NORMAL STREAM FLOWS FOR THIS
TIME OF YEAR. ANY EARLY EVENING ACTIVITY OVER FAR ERN SXNS SHOULD
PUSH OUT OF THE CWA AFTER 00Z AS NOTICEABLY DRIER AIR SPREADS
ACROSS THE AREA IN THE WAKE OF THE COLD FRONT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
A COOLER BROAD CYCLONIC FLOW WILL BEGIN TO GRIP THE REGION ON
WEDNESDAY WITH DAYTIME HIGHS SOME 15-20F COOLER THAN TODAY. THE
COOLER AIR ALOFT SHOULD PROMOTE AFTN CU DEVELOPMENT WITH A NW
BREEZE ADDING TO THE RELATIVE CHILL. THE MODELS SHOW A SHORTWAVE
TROUGH MOVING QUICKLY ESEWD FROM THE UPPER GREAT LAKES THROUGH
CENTRAL APPALACHIANS AND NORTHERN MID ATLANTIC STATES THU-FRI WITH
SOME SHOWERS POSSIBLE ON THU. A SFC LOW IS FCST TO EMERGE OFF THE
CAROLINAS INTO FRIDAY WITH SOME SPREAD IN THE GUIDANCE...OWING TO
VARIABILITY IN THE HANDLING OF THE PARENT SHORTWAVE. A SECONDARY
COLD FRONT SHOULD CROSS THE AREA ON FRIDAY FOLLOWED BY ANOTHER
SHOT OF COOL AIR. CONFIDENCE REMAINS ON THE LOW SIDE FOR FROST
THU MORNING IN THE NORTH AS THE PATTERN DOES NOT LOOK FAVORABLE
OR CONDUCIVE.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
CONFIDENCE IN FROST POTENTIAL IS MUCH HIGHER ON SATURDAY MORNING
OVER THE NORTH-CNTRL ZONES WITH A LARGE AREA OF HP FCST TO SETTLE
OVER CENTRAL PA. WILL ADD FROST WORDING TO THE HWO FOR THE 3 ZONES
THAT ARE STILL NOT IN THE GROWING SEASON /MCKEAN-POTTER-ELK/. DRY
WX SHOULD HOLD ON UNTL EARLY NEXT WEEK AS THE UPPER RIDGE BUILDS
AGAIN OVER THE ERN U.S. AN E-W FRONTAL BOUNDARY COULD BE A FOCUS
FOR PCPN AS IT PIVOTS AND LIFTS NWD IN A SIMILAR FASHION TO THIS
PAST WEEKEND. CLOSELY FOLLOWED THE ROBUST NATIONAL SUPERBLEND
PROTOTYPE GUIDANCE FOR TEMPERATURES WHICH FAVORS A GRADUAL
WARMING TREND FOR THE AREA BEYOND THE END OF THE PERIOD.
&&
.AVIATION /11Z TUESDAY THROUGH SATURDAY/...
PATCHY DENSE FOG AND LOW STRATOCU IS CONTINUING THROUGH THE
EASTERN TAF SITES. EXPECT FOR THIS TO PERSIST OVER THE NEXT FEW
HOURS...LIFTING BETWEEN 13Z TO 15Z. IFR AT BFD AND JST WILL
PERSIST AS WELL AND BY 14Z SHOULD LIFT TO MVFR ADN BY 16Z BE VFR.
THE COLD FRONT IS SLOWLY MOVING EASTWARD AND WILL MOVE THROUGH
THIS AFTERNOON. STILL CAN/T RULE OUT AN ISOLD SHRA/TSRA ACROSS
EASTERN PA ARND MIDDAY WITH PASSAGE OF THE FRONT.
OTHERWISE...EXPECT A RETURN TO WIDESPREAD VFR CONDS...AS A GUSTY
WEST WIND BRINGS MUCH DRIER AIR INTO THE REGION BEHIND THE COLD
FRONT.
GUSTY WINDS SHOULD SUBSIDE BY EARLY EVENING...WITH STRONG
NORTHWESTERLY FLOW INCREASING OVERNIGHT WHICH COULD MIX DOWN
STRONTER WINDS EARLY WEDNESDAY MORNING.
OUTLOOK...
WED-SAT...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...STEINBUGL
AVIATION...FITZGERALD/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
512 AM EDT TUE MAY 19 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS CENTRAL PENNSYLVANIA TODAY WITH A
MARGINAL/ISOLATED SEVERE WEATHER RISK FROM THE EASTERN COAL REGION
INTO THE POCONOS. A COOLER AND MAINLY DRY WEATHER PATTERN WITH
NEAR TO BELOW NORMAL TEMPERATURES WILL GRIP THE REGION FROM
WEDNESDAY INTO THE WEEKEND...FOLLOWED BY A GRADUAL WARMING TREND
WITH UNSETTLED CONDITIONS THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
09Z RADAR SHOWS WHAT IS LEFT OF MEASURABLE SHOWERS MOVG EWD ALONG
RDG-LNS LINE. WILL TAPER DOWN POPS THROUGH MID MORNING BASED ON
RADAR TRENDS AND HRRR. SUBTLE BACKDOOR TYPE FRONT HAS ALLOWED
MARINE AIR/EASTERLY LLVL FLOW TO REACH AS FAR WEST AS THE SUSQ
RIVER WITH WDSPRD LOW CIGS AND FOG EXPECTED TO PERSIST THROUGH
DAYBREAK. TO THE WEST ALONG THE ALLEGHANY FRONT...WEAK BUT MOIST
UPSLOPE IS PROMOTING LOW CIGS AND FOG ALONG THE RT 219 CORRIDOR.
SHORTWAVE CURRENTLY MOVING THROUGH THE UPPER GREAT LAKES WILL
TEAM WITH ADDITIONAL ENERGY DROPPING DOWN AROUND THE HUDSON BAY
UPPER TROUGH TO FLATTEN THE ANOMALOUS RIDGE OVER THE NORTHEASTERN
U.S. ONCE THE LOW CLOUDS/FOG BURN OFF THIS MORNING...STRONG PRE-
FRONTAL BOUNDARY LAYER WARMING SHOULD PROVE MORE THAN ADEQUATE FOR
CONVECTION WITH HRRR SHOWING DEVELOPMENT EAST OF THE SUSQ RIVER
BY 18-19Z. THE SPC DAY 1 MARGINAL RISK JUST CLIPS EAST-CENTRAL PA
FROM THE COAL REGION ENEWD INTO THE POCONOS WITH INCREASING SHEAR
TO THE NORTH. HOWEVER DESPITE WEAKER FLOW ALOFT...CANT RULE OUT
THREAT FOR GUSTY WINDS/SMALL HAIL IN MORE CAPE-DRIVEN STORMS
WITHIN STEEP LLVL LAPSE RATE ENVIRONMENT OVER THE LWR SQV. HEAVY
DOWNPOURS COULD POSE MINOR FLOOD THREAT PROBABLY MORE SO CONFINED
TO URBAN/POOR DRAINAGE AREAS VS. SMALL STREAMS AND CREEKS GIVEN
DRY ANTECEDENT CONDITIONS AND BELOW NORMAL STREAM FLOWS FOR THIS
TIME OF YEAR. ANY EARLY EVENING ACTIVITY OVER FAR ERN SXNS SHOULD
PUSH OUT OF THE CWA AFTER 00Z AS NOTICEABLY DRIER AIR SPREADS
ACROSS THE AREA IN THE WAKE OF THE COLD FRONT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
A COOLER BROAD CYCLONIC FLOW WILL BEGIN TO GRIP THE REGION ON
WEDNESDAY WITH DAYTIME HIGHS SOME 15-20F COOLER THAN TODAY. THE
COOLER AIR ALOFT SHOULD PROMOTE AFTN CU DEVELOPMENT WITH A NW
BREEZE ADDING TO THE RELATIVE CHILL. THE MODELS SHOW A SHORTWAVE
TROUGH MOVING QUICKLY ESEWD FROM THE UPPER GREAT LAKES THROUGH
CENTRAL APPALACHIANS AND NORTHERN MID ATLANTIC STATES THU-FRI WITH
SOME SHOWERS POSSIBLE ON THU. A SFC LOW IS FCST TO EMERGE OFF THE
CAROLINAS INTO FRIDAY WITH SOME SPREAD IN THE GUIDANCE...OWING TO
VARIABILITY IN THE HANDLING OF THE PARENT SHORTWAVE. A SECONDARY
COLD FRONT SHOULD CROSS THE AREA ON FRIDAY FOLLOWED BY ANOTHER
SHOT OF COOL AIR. CONFIDENCE REMAINS ON THE LOW SIDE FOR FROST
THU MORNING IN THE NORTH AS THE PATTERN DOES NOT LOOK FAVORABLE
OR CONDUCIVE.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
CONFIDENCE IN FROST POTENTIAL IS MUCH HIGHER ON SATURDAY MORNING
OVER THE NORTH-CNTRL ZONES WITH A LARGE AREA OF HP FCST TO SETTLE
OVER CENTRAL PA. WILL ADD FROST WORDING TO THE HWO FOR THE 3 ZONES
THAT ARE STILL NOT IN THE GROWING SEASON /MCKEAN-POTTER-ELK/. DRY
WX SHOULD HOLD ON UNTL EARLY NEXT WEEK AS THE UPPER RIDGE BUILDS
AGAIN OVER THE ERN U.S. AN E-W FRONTAL BOUNDARY COULD BE A FOCUS
FOR PCPN AS IT PIVOTS AND LIFTS NWD IN A SIMILAR FASHION TO THIS
PAST WEEKEND. CLOSELY FOLLOWED THE ROBUST NATIONAL SUPERBLEND
PROTOTYPE GUIDANCE FOR TEMPERATURES WHICH FAVORS A GRADUAL
WARMING TREND FOR THE AREA BEYOND THE END OF THE PERIOD.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
AN UNSTABLE AIR MASS AHEAD OF AN APPROACHING COLD FRONT WILL
ALLOW FOR SCATTERED SHRA TO CONTINUE TO MOVE ACROSS CENTRAL PA
OVERNIGHT. ANY OF THESE SHRA COULD PRODUCE BRIEF VIS REDUCTIONS.
HOWEVER...THE MAIN AVIATION CONCERN OVERNIGHT AND THROUGH THE
FIRST HALF OF THE MORNING WILL BE THE DEVELOPING LOW CIGS ACROSS
CENTRAL PA. THE LOW CIGS IN EASTERN PA IS A RESULT OF MARINE AIR
FLOWING OFF THE ATLANTIC OCEAN...COUPLED WITH THE AMPLE LOW LEVEL
MOISTURE PROVIDED BY THE SHOWERS FROM EARLIER.
IFR CIGS ARE ALREADY PRESENT ACROSS MUCH OF EASTERN AND WESTERN
PA AT 06Z...WITH AOO AND UNV THE LONE HOLD OUTS. NEAR TERM MDL
DATA SUPPORT THESE LOW CIGS CONTINUING THROUGH 12Z. THE WESTERN
TAF SITES THAT ARE IFR ARE DUE TO A PLUME OF MOISTURE AHEAD OF
APPROACHING COLD FRONT THAT WILL ASCEND THE W MTNS...LIKELY
RESULTING IN IFR CIGS AT KBFD/KJST OVERNIGHT. BOTH THE SREF AND
LATEST HRRR SUPPORT THIS SCENARIO. MOST FAVORABLE CONDS OVERNIGHT
SHOULD BE AT KAOO/KUNV...WHERE SIG REDUCTIONS APPEAR UNLIKELY.
LOW CIGS ACROSS THE W MTNS AND EASTERN PA SHOULD LIFT BY LATE AM.
CAN/T RULE OUT AN ISOLD SHRA/TSRA ACROSS EASTERN PA ARND MIDDAY
WITH PASSAGE OF COLD FRONT. OTHERWISE...EXPECT A RETURN TO
WIDESPREAD VFR CONDS...AS A GUSTY WEST WIND BRINGS MUCH DRIER AIR
INTO THE REGION BEHIND THE COLD FRONT.
OUTLOOK...
WED-SAT...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...STEINBUGL
AVIATION...FITZGERALD/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
247 AM EDT TUE MAY 19 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS CENTRAL PENNSYLVANIA TODAY WITH A
MARGINAL/ISOLATED SEVERE WEATHER RISK FROM THE EASTERN COAL REGION
INTO THE POCONOS. A COOLER WEATHER PATTERN WILL GRIP THE REGION
INTO THE WEEKEND BEFORE SUMMER HEAT RETURNS BY MEMORIAL DAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
06Z RADAR SHOWS SCT SHOWERS MAINLY S/E OF I-99 CORRIDOR WITH THE
GREATEST CONCENTRATION /INCLUDING RECENT UPTICK/ OF PCPN ACTIVITY
FOCUSED OVER THE LWR SQV. HRRR FAVORS THIS SCENARIO AND PLACED
HIGHEST POPS FROM THE SOUTH-CENTRAL MTNS NEWD INTO THRU THE SUSQ
VLY. SUBTLE BACKDOOR TYPE FRONT HAS ALLOWED MARINE AIR/EASTERLY
LLVL FLOW TO PENETRATE WWD TO ALONG THE SUSQ RIVER WITH WDSPRD LOW
CIGS AND FOG EXPECTED TO PERSIST THROUGH DAYBREAK. TO THE
WEST...WEAK BUT MOIST UPSLOPE IS PROMOTING LOW CIGS AND FOG ALONG
THE RT 219 CORRIDOR. SITES SUCH AS AOO/UNV WILL LKLY SEE AT LEAST
SOME PATCHY FOG GIVEN LGT WINDS AND MUGGY AIR W/60-65F DEWPTS BUT
MAY ESCAPE THE WORST CONDITIONS.
SHORTWAVE CURRENTLY MOVING THROUGH THE WESTERN GREAT LAKES WILL
TEAM WITH ADDITIONAL ENERGY DROPPING DOWN FROM HUDSON BAY UPPER
TROUGH TO FLATTEN THE ANOMALOUS RIDGE OVER THE NORTHEASTERN U.S.
ONCE THE LOW CLOUDS/FOG ARE ERODED...STRONG PRE-FRONTAL BOUNDARY
LAYER WARMING SHOULD PROVE MORE THAN ADEQUATE FOR CONVECTION WITH
HRRR SHOWING DEVELOPMENT ALONG/EAST OF THE SUSQ VLY BY 18-19Z. SPC
HAS OUTLOOKED EAST-CENTRAL PA FROM THE COAL REGION ENEWD INTO THE
POCONOS WITH MARGINAL SEVERE RISK WITH INCREASING SHEAR TO THE
NORTH. HOWEVER DESPITE WEAKER FLOW ALOFT...CANT RULE OUT THREAT
FOR GUSTY WINDS/SMALL HAIL IN MORE CAPE-DRIVEN STORMS IN STEEP
LLVL LAPSE RATE ENVIRONMENT OVER THE LWR SQV. HEAVY DOWNPOURS
COULD POSE MINOR FLOOD THREAT PROBABLY MORE SO TO URBAN/POOR
DRAINAGE AREAS VS. SMALL STREAMS GIVEN RECENT DRY CONDITIONS AND
BELOW NORMAL STREAM FLOWS FOR THIS TIME OF YEAR.
ANY EARLY EVENING ACTIVITY OVER FAR ERN SXNS SHOULD PUSH OUT OF
THE CWA AFTER 00Z AS NOTICEABLY DRIER AIR SPREADS ACROSS THE AREA
IN THE WAKE OF THE COLD FRONT.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
A COOLER BROAD CYCLONIC FLOW WILL BEGIN TO GRIP THE REGION ON
WEDNESDAY WITH DAYTIME HIGHS SOME 15-20F COOLER THAN TODAY. THE
COOLER AIR ALOFT SHOULD PROMOTE AFTN CU DEVELOPMENT WITH A NW
BREEZE ADDING TO THE RELATIVE CHILL. THE MODELS SHOW A SHORTWAVE
TROUGH MOVING QUICKLY FROM THE UPPER GREAT LAKES TOWARD THE MID
ATLANTIC WITH SOME SHOWERS POSSIBLY REACHING THE SW MTNS BY 12Z
THU. THE OTHER CONCERN IS FROST FOR THE NRN MTNS WITH THE FINAL 3
ZONES STARTING THE GROWING SEASON ON 5/21 BUT THE OVERALL PATTERN
DOES NOT LOOK THAT FAVORABLE ATTM SUGGESTING LOW CONFIDENCE.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
A WEAK WAVE EJECTS EASTWARD FROM THE S PLAINS TOWARD THE
CAROLINA/S ON THU...WHILE TROUGH CONTINUES TO SPIN OVER EASTERN
CANADA. CENTRAL PA REMAINS BETWEEN THESE TWO FEATURES...WHICH WILL
KEEP US DRY. EVEN WITH NW FLOW...DAYTIME TEMPS WILL REBOUND A BIT
WARMER EACH DAY. BUT DIURNAL TEMP RANGES WILL BE FAIRLY LARGE
THANKS TO THE DRIER AIRMASS...WHICH WILL BRING CHILLY MORNINGS.
THE COLDEST CONTINUES TO LOOK LIKE THURSDAY MORNING WHERE THERE
REMAINS A RISK FOR PATCHY FROST...MAINLY OVER THE NORTH-CENTRAL
ZONES WHERE GUIDANCE IS SHOWING POSS FOR MID 30S AOA BFD /JUST IN
TIME FOR THE START OF THE GROWING SEASON/.
THE WEAK LOW OVER CAROLINAS/MID ATLANTIC REGION SLIDES OFFSHORE
FRI...WITH SPRAWLING HIGH PRESSURE AREA BUILDING IN FOR SAT/SUN.
ONCE RIDGE AXIS SLIDES BY SAT NIGHT...HUMIDITY WILL BEGIN TO
SLOWLY INCREASE ON SUNDAY WITH RISING TEMPS /AND ISOLATED
LATE DAY CONVECTION POSS/. WARMER AND MUGGIER CONDITIONS ON
MEMORIAL DAY...WITH SCATTERED TO EVEN NUMEROUS SHOWERS/TSTMS IN
THE FORECAST.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AN UNSTABLE AIR MASS AHEAD OF AN APPROACHING COLD FRONT WILL
ALLOW FOR SCATTERED SHRA TO CONTINUE TO MOVE ACROSS CENTRAL PA
OVERNIGHT. ANY OF THESE SHRA COULD PRODUCE BRIEF VIS REDUCTIONS.
HOWEVER...THE MAIN AVIATION CONCERN OVERNIGHT AND THROUGH THE
FIRST HALF OF THE MORNING WILL BE THE DEVELOPING LOW CIGS ACROSS
CENTRAL PA. THE LOW CIGS IN EASTERN PA IS A RESULT OF MARINE AIR
FLOWING OFF THE ATLANTIC OCEAN...COUPLED WITH THE AMPLE LOW LEVEL
MOISTURE PROVIDED BY THE SHOWERS FROM EARLIER.
IFR CIGS ARE ALREADY PRESENT ACROSS MUCH OF EASTERN AND WESTERN
PA AT 06Z...WITH AOO AND UNV THE LONE HOLD OUTS. NEAR TERM MDL
DATA SUPPORT THESE LOW CIGS CONTINUING THROUGH 12Z. THE WESTERN
TAF SITES THAT ARE IFR ARE DUE TO A PLUME OF MOISTURE AHEAD OF
APPROACHING COLD FRONT THAT WILL ASCEND THE W MTNS...LIKELY
RESULTING IN IFR CIGS AT KBFD/KJST OVERNIGHT. BOTH THE SREF AND
LATEST HRRR SUPPORT THIS SCENARIO. MOST FAVORABLE CONDS OVERNIGHT
SHOULD BE AT KAOO/KUNV...WHERE SIG REDUCTIONS APPEAR UNLIKELY.
LOW CIGS ACROSS THE W MTNS AND EASTERN PA SHOULD LIFT BY LATE AM.
CAN/T RULE OUT AN ISOLD SHRA/TSRA ACROSS EASTERN PA ARND MIDDAY
WITH PASSAGE OF COLD FRONT. OTHERWISE...EXPECT A RETURN TO
WIDESPREAD VFR CONDS...AS A GUSTY WEST WIND BRINGS MUCH DRIER AIR
INTO THE REGION BEHIND THE COLD FRONT.
OUTLOOK...
WED-SAT...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...RXR
AVIATION...FITZGERALD/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
150 AM EDT TUE MAY 19 2015
.SYNOPSIS...
A NEARLY STATIONARY...BACK DOOR COLD FRONT WILL BE LOCATED ACROSS
THE SUSQUEHANNA VALLEY TONIGHT. THIS BOUNDARY WILL COMBINE WITH AN
EXTENSIVE PLUME OF DEEP MOISTURE TO FOCUS ADDITIONAL HEAVY
SHOWERS AND THUNDERSTORMS ACROSS CENTRAL PENNSYLVANIA AND THE
SUSQUEHANNA VALLEY OVERNIGHT. A SEPARATE COLD FRONT WILL APPROACH
FROM THE UPPER MIDWEST...PUSHING SOUTHEAST ACROSS THE COMMONWEALTH
TUESDAY AND BRINGING WITH IT...ANOTHER FEW ROUNDS OF SHOWERS AND
THUNDERSTORMS TUESDAY. A COOLER AND DRY AIRMASS WILL MOVE IN
BEHIND THE COLD FRONT FOR THE MIDDLE OF THIS WEEK. SATURDAY AND
SUNDAY SHOULD FEATURE DRY WEATHER WITH PLEASANTLY LOW HUMIDITY
AND NEAR TO SLIGHTLY BELOW NORMAL HIGH TEMPERATURES. WARMER
TEMPERATURES AND MUGGINESS WILL RETURN FOR MEMORIAL DAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
VERY HIGH PWAT AIR WILL STAY PARKED OVER THE AREA THROUGH THE
OVERNIGHT. HOWEVER...WITH THE LOSS OF DAYTIME HEATING...
INSTABILITY AND PRECIP RATES IN THE SHRA/TSRA HAVE STEADILY
DIMINISHED.
NEARLY STATIONARY/BACK DOOR CFRONT JUST WEST OF THE SUSQ RIVER
MAINSTEM WILL HELP TO REFIRE AND FOCUS ADDITIONAL LOW-TOPPED
CONVECTION THROUGH THE OVERNIGHT HOURS WITH BASIN AVG RAINFALL
AMOUNTS GENERALLY AROUND ONE QUARTER OF AN INCH. THE FEW LOCATIONS
THAT SEE SLOW MVG OR TRAINING HEAVY SHRA/TSRA WILL PICK UP ANOTHER
0.5 TO 1.0 OF RAIN...PERHAPS LEADING TO SOME ADDITIONAL MINOR
FLOODING NEAR AND TO THE EAST OF A KSEG TO KMDT AND KTHV LINE.
ELSEWHERE...A RATHER MILD/MUGGY NIGHT IS IN STORE WITH ISOLATED TO
SCTD SHRA. LOWS EARLY TUESDAY WILL BE IN THE 60-65F RANGE FROM
NORTH TO SOUTH.
FOG AND LOW CLOUDS ARE AGAIN EXPECTED OVER MOST/ALL OF THE AREA
LATE TONIGHT/EARLY TUESDAY. PERHAPS ONLY THE PLACES WHICH CAN
KEEP WIND OVER 5-6KTS THROUGH THE NIGHT - MAINLY HIGHER ELEVS IN
THE WEST - CAN STAY AWAY FROM BAD VISBYS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
COLD FRONT PUSHES SE ACROSS THE REGION TUESDAY. DEWPOINTS DROP
THROUGH THE DAY IN THE NW HALF OF THE CWA...BUT THE SE WILL STAY
VERY WARM AND HUMID THROUGH MOST OF THE AFTERNOON. PWATS STILL AOA
35 MM NEAR AND SE OF THE I-81 CORRIDOR THROUGH 18Z TUESDAY...AND
THE COMBINATION OF THE HEAT AND MOISTURE WILL HELP TO FIRE UP SFC-
BASED CAPES INTO THE 1500-2000 J/KG RANGE. EXPECT A BKN LINE OR
TWO OF SHOWERS AND PERHAPS A RUMBLE OF THUNDER ALONG THE CFRONT
FROM NEAR KELM...TO KUNV AND KJST DURING THE MIDDAY HOURS. THIS
AREA OF CONVECTION WILL LIKELY INTENSIFY INTO A BKN LINE OF STRONG
TSRA AFTER 16Z TUESDAY NEAR A KAVP TO KSEG AND KHGR LINE.
SPC/S MARGINAL RISK FOR SVR TSRA NIPS A FEW OF OUR EASTERN
COUNTIES TUESDAY...AND COULD SEE THIS BEING EXTENDED A TAD FURTHER
TO THE SW BASED MAINLY ON INSTABILITY AND A LOCALIZED LARGE HAIL
THREAT /COMPARED TO BETTER DEEP LAYER SHEAR FURTHER NORTH/.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
AREA OF SHOWERS/TSTMS WILL BE DEPARTING LATE TUE/EARLY TUE
EVE...ASSOCIATED WITH A COLD FRONT CLEARING THE REGION.
IN IT/S WAKE...RESPECTABLE ANTICYCLONE WILL BUILD IN FROM THE WEST
WITH A PUSH OF NOTICEABLY COOLER AND DRIER AIR FILTERING IN FOR
MIDWEEK. A WEAK WAVE EJECTS EASTWARD FROM THE S PLAINS TOWARD THE
CAROLINA/S ON THU...WHILE TROUGH CONTINUES TO SPIN OVER EASTERN
CANADA. CENTRAL PA REMAINS BETWEEN THESE TWO FEATURES...WHICH WILL
KEEP US DRY. EVEN WITH NW FLOW...DAYTIME TEMPS WILL REBOUND A BIT
WARMER EACH DAY. BUT DIURNAL TEMP RANGES WILL BE FAIRLY LARGE
THANKS TO THE DRIER AIRMASS...WHICH WILL BRING CHILLY MORNINGS.
THE COLDEST CONTINUES TO LOOK LIKE THURSDAY MORNING WHERE THERE
REMAINS A RISK FOR PATCHY FROST...MAINLY OVER THE NORTH-CENTRAL
ZONES WHERE GUIDANCE IS SHOWING POSS FOR MID 30S AOA BFD /JUST IN
TIME FOR THE START OF THE GROWING SEASON/.
THE WEAK LOW OVER CAROLINAS/MID ATLANTIC REGION SLIDES OFFSHORE
FRI...WITH SPRAWLING HIGH PRESSURE AREA BUILDING IN FOR SAT/SUN.
ONCE RIDGE AXIS SLIDES BY SAT NIGHT...HUMIDITY WILL BEGIN TO
SLOWLY INCREASE ON SUNDAY WITH RISING TEMPS /AND ISOLATED
LATE DAY CONVECTION POSS/. WARMER AND MUGGIER CONDITIONS ON
MEMORIAL DAY...WITH SCATTERED TO EVEN NUMEROUS SHOWERS/TSTMS IN
THE FORECAST.
&&
.AVIATION /05Z TUESDAY THROUGH SATURDAY/...
AN UNSTABLE AIR MASS AHEAD OF AN APPROACHING COLD FRONT WILL
ALLOW FOR SCATTERED SHRA TO CONTINUE TO MOVE ACROSS CENTRAL PA
OVERNIGHT. ANY OF THESE SHRA COULD PRODUCE BRIEF VIS REDUCTIONS.
HOWEVER...THE MAIN AVIATION CONCERN OVERNIGHT AND THROUGH THE
FIRST HALF OF THE MORNING WILL BE THE DEVELOPING LOW CIGS ACROSS
CENTRAL PA. THE LOW CIGS IN EASTERN PA IS A RESULT OF MARINE AIR
FLOWING OFF THE ATLANTIC OCEAN...COUPLED WITH THE AMPLE LOW LEVEL
MOISTURE PROVIDED BY THE SHOWERS FROM EARLIER.
IFR CIGS ARE ALREADY PRESENT ACROSS MUCH OF EASTERN AND WESTERN
PA AT 06Z...WITH AOO AND UNV THE LONE HOLD OUTS. NEAR TERM MDL
DATA SUPPORT THESE LOW CIGS CONTINUING THROUGH 12Z. THE WESTERN
TAF SITES THAT ARE IFR ARE DUE TO A PLUME OF MOISTURE AHEAD OF
APPROACHING COLD FRONT THAT WILL ASCEND THE W MTNS...LIKELY
RESULTING IN IFR CIGS AT KBFD/KJST OVERNIGHT. BOTH THE SREF AND
LATEST HRRR SUPPORT THIS SCENARIO. MOST FAVORABLE CONDS OVERNIGHT
SHOULD BE AT KAOO/KUNV...WHERE SIG REDUCTIONS APPEAR UNLIKELY.
LOW CIGS ACROSS THE W MTNS AND EASTERN PA SHOULD LIFT BY LATE AM.
CAN/T RULE OUT AN ISOLD SHRA/TSRA ACROSS EASTERN PA ARND MIDDAY
WITH PASSAGE OF COLD FRONT. OTHERWISE...EXPECT A RETURN TO
WIDESPREAD VFR CONDS...AS A GUSTY WEST WIND BRINGS MUCH DRIER AIR
INTO THE REGION BEHIND THE COLD FRONT.
OUTLOOK...
WED-SAT...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...RXR
AVIATION...FITZGERALD/CERU
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1037 PM EDT WED MAY 20 2015
.SYNOPSIS...
UNSETTLED WEATHER WILL CROSS THE AREA LATE TONIGHT INTO THURSDAY
WITH THE PASSING OF A COLD FRONT. DRIER CANADIAN HIGH PRESSURE WILL
BUILD OVER THE CAROLINAS AND NORTHEAST GEORGIA FRIDAY AND REMAIN
THROUGH THE WEEKEND. SOUTHERLY FLOW MOISTURE AROUND BERMUDA HIGH
PRESSURE WILL GRADUALLY RETURN EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 1030 PM...KGSP RADAR INDICATED ONLY A FEW WEAK RETURNS ACROSS
THE FORECAST AREA. REGIONAL RADAR CONTINUED TO SHOW A BAND OF
SHRA/TSRA ACROSS NRN GA INTO EASTERN TN...SLIDING EAST. THE UPSTREAM
CONVECTION HAS DEVELOPED WITHIN AN AREA OF WEAK INSTABILITY...WHICH
HAS INCREASED SINCE SUNSET. WARMING CLOUD TOPS AND REDUCED LIGHTNING
COUNTS INDICATE THAT THE CONVECTION HAS RECENTLY WEAKEN.
HOWEVER...THE RAP SHOWS LINGERING LOW VALUES OF CAPE REMAINING PAST
MIDNIGHT. I WILL CONTINUE TO FORECAST 20-30 POPS ACROSS THE FORECAST
AREA THROUGH TONIGHT...WITH VALUES RISING DURING THE PRE DAWN HOURS.
THE FORECAST UPDATE WILL ALSO FEATURE ADJUSTMENT TO SKY
GRIDS...TEMPERATURES...AND DEWPOINTS.
AS OF 750 PM...LATEST RADAR TRENDS INDICATED THAT A CLUSTER OF WEAK
SHOWERS WERE MOVING EAST FROM THE GSP AREA...SOUTH OF THE STATE
LINE. THESE SHRA WERE TRIGGER NEAR A WEST TO EAST WARM FROM ACROSS
THE REGION. RECENT SPC ANALYSIS INDICATED THAT THE REGION THE SHRA
EXISTED WAS BECOMING INCREASINGLY LESS UNSTABLE...WITH CIN VALUES
AROUND 50 J/KG AND CAPE AROUND 250 J/KG. IT APPEARS THAT BASED ON
THE STABILITY PATTERN AND HISTORY OF OUTFLOW BOUNDARIES...NEW
CONVECTION WILL LIKELY FAVOR AREAS SOUTH OF THE RECENT ACTIVITY. I
WILL UPDATE THE FORECAST TO REFLECT THE LATEST THINKING.
LATE TONIGHT...A MID LEVEL SHORT WAVE WILL RIPPLE OVER THE SOUTHERN
APPALACHIANS...AS A SFC LOW DEVELOPS ACROSS THE WESTERN CAROLINAS.
CIRCULATION AROUND THE LOW SHOULD RESULT IN A INCREASE IN CAPE
ACROSS THE PIEDMONT. I WILL ADJUST POPS AND TSRA MENTION FOR LATE
TONIGHT INTO THURSDAY MORNING.
AS OF 550 PM...LATEST RADAR IMAGES INDICATED A FEW SHOWERS ACROSS
THE ESCARPMENT...PRIMARILY FROM POLK COUNTY WEST INTO NE GA. THESE
SHOWERS HAVE DEVELOPED IN THE VICINITY OF A WARM FRONT. NORTH OF THE
FRONT...ACROSS THE I-40 CORRIDOR DEWPOINTS RANGED IN THE U30S...WITH
DEWPOINTS IND THE MID TO U60S ACROSS THE UPPER SAVANNAH RIVER
VALLEY. LATEST SPC MESOSCALE ANALYSIS INDICATED CAPES ABOVE 500 J`KG
ACROSS THE UPSTATE...WITH NEAR ZERO ACROSS I-40. I WILL EXPAND CHC
POPS ACROSS THE HIGH TERRAIN ALONG THE CAROLINA BORDER AND NE GA
THROUGH EARLY THIS EVENING. IN ADDITION...I WILL INCREASE CHC POPS
ACROSS THE WESTERN NC MTNS A LITTLE EARLIER...BASED ON RADAR TRENDS
OVER MIDDLE TN. IN ADDITION...OBSERVED TEMPERATURES RANGE A LITTLE
WARMER THAN FORECAST...I HAVE ADJUSTED HRLY TEMPS AND DEWPOINTS.
AS OF 245 PM EDT WEDNESDAY...A WEAK UPPER SHORTWAVE CONTINUES TO
SLIDE THROUGH THE OH/TN VALLEYS AT THIS TIME AMIDST NEARLY ZONAL H5
FLOW. AT THE SURFACE...A COLD FRONT ASSOCIATED WITH SAID UPPER WAVE
IS SLIDING EAST THROUGH CENTRAL ARKANSAS. CLOSER TO HOME...REMNANT
COLD FRONTAL PASSAGE FROM TUESDAY HAS BEGUN TO LIFT NORTHWARD AS A
WARM FRONT WITH DEWPOINTS GRADUALLY INCREASING. RECENT OBS AROUND
THE REGION INDICATE DEWPOINTS IN THE UPPER 40S ALONG AND NORTH OF
I40...WITH DEWPOINTS INCREASING FURTHER SOUTH TOWARD THE I85
CORRIDOR. IN RESPONSE...THE 18Z MESOANALYSIS INDICATES MINIMALLY
INCREASING CAPE OVER THESE AREAS. THUS...CONTINUED WITH AN ISOLATED
POP MENTION OVER THE CLIMO FAVORED REGIONS OF THE UPPER FRENCH BROAD
VALLEY...AND ALSO PORTIONS OF THE I85 CORRIDOR.
BEYOND THAT THE FOCUS SHIFTS TO THE ABOVE MENTIONED UPPER WAVE AS IT
APPROACHES FROM THE WEST. MODELS CONTINUE TO PROG A DYING BAND OF
CONVECTION SLIDING INTO THE NC HIGH TERRAIN OVERNIGHT...BEFORE
PUSHING THROUGH THE REMAINDER OF WESTERN NC THROUGH MID/LATE
MORNING. EXPECTING CONVECTION TO REINITIATE OVER THE NC PIEDMONT AS
THE PRIMARY UPPER VORT MAX SLIDES BY TO THE NORTH BY AROUND DAYBREAK
THURSDAY...WITH ENOUGH INSTABILITY IN/AROUND THE REGION TO PROMOTE A
FEW THUNDERSTORMS. ALL IN ALL IT LOOKS RATHER UNEVENTFUL AS THE
FRONT ADVECTS THROUGH THE AREA BY 14Z-15Z WITH SURFACE FLOW VEERING
SHARPLY WEST/NORTHWEST AS HIGH PRESSURE SLIDES IN. INCREASED
PRESSURE GRADIENT ALONG WITH MIXING OF ENHANCED LOW LEVEL WINDS WILL
LIKELY PROMOTE SOME GUSTS EARLY ON IN THE DAY...AMONGST CLEARING
SKIES. TEMPERATURES THROUGH THE PERIOD WILL COOL SLIGHTLY BEHIND
THE COLD FRONTAL PASSAGE...HOWEVER SHOULD REMAIN ABOVE NORMAL.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM WED...THE SHORT RANGE SHAPES UP TO BE FAIRLY QUIET. A
SHORT WAVE WILL PASS BY WELL TO THE N ON THURSDAY EVENING...WHICH
SHOULD PUSH THE UPPER TROF AXIS ACROSS THE WESTERN CAROLINAS/NE
GEORGIA OVERNIGHT. SOME RESIDUAL MOISTURE MAY GET FORCED UP THE W
SIDE OF THE MTNS BY THE NW FLOW...BUT THAT SHOULD NOT AMOUNT TO MUCH
MORE THAN A SMALL CHANCE OF SHOWERS THAT WOULD TAPER OFF BY
MIDNIGHT. FROM THAT POINT ONWARD...THE UPPER PATTERN EVOLVES SLOWLY
WITH A RIDGE AXIS TO THE WEST THROUGH THE END OF SATURDAY. THAT
SHOULD TAKE SURFACE HIGH PRESSURE SLOWLY PAST TO THE NORTH ON FRIDAY
AND SATURDAY...PERHAPS REACHING THE MID ATLANTIC COAST BY SUNSET
SATURDAY. MOISTURE RETURN IS NOT EXPECTED AS THE UPPER RIDGE AXIS
REMAINS WELL TO THE WEST. THUS...EXPECT DRY WEATHER AND NORMAL TEMPS
FOR BOTH FRIDAY AND SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 205 PM EDT WED...A STRONG ULVL RIDGE WILL CONTINUE TO BUILD
ACROSS THE ERN CONUS SAT NIGHT WITH THE AXIS MOVING OF THE EAST
COAST BY LATE MONDAY. THE GFS H5 Z ENS MEAN AGREES WELL WITH THE OP
MODEL PROGRESSIONS AND VERY LITTLE MEMBER SPREAD IS SEEN ACROSS THE
SE/RN STATES THROUGH MOST OF THE PERIOD. IN THE LOWER LEVELS...A
STRENGTHENING BERMUDA HIGH WILL MAINTAIN A RIDGE ACROSS THE
CAROLINAS SUN/MON BEFORE BREAKING DOWN TUE/WED AS A UPPER S/W AND
COLD FRONT APPROACHES FROM THE WEST.
THERE ISN/T MUCH CHANGE IN THE SENSIBLE WX FCST FROM THE PREVIOUS
PACKAGE. THE BEST GOM MOISTURE FLUX WILL BE MAXIMIZED WEST OF THE
CWFA INTO MON...BEFORE ADDED ATL MOISTURE BEGINS TO ADVECT FROM THE
SE. MODEL SOUNDINGS SHOW A PERSISTENT MLVL SUBS INVERSION INTO MON
AS WELL...SO ANY CONVEC ACTIVITY SHOULD REMAIN RELEGATED ACROSS THE
HIGHER TERRAIN AND SHUNTED WITH DEEPER SHOWERS DEVELOPING MON
AFTERNOON IN LOCALIZED MECH LIFT...POSSIBLY PRODUCING A FEW TSTMS.
POPS REMAIN SLIGHT TO LOW END CHANCE THROUGH MON...WITH AN INCREASE
TO MID RANGE MTN POPS TUE/WED AS THE SUBS PATTERN WEAKENS IN A
DIURNALLY DESTABILIZING ATMOS. TEMPS WEREN/T CHANGED MUCH...STILL
EXPECT A MODEST INCREASE EACH AFTERNOON WITH MAXES ARND 10 DEGREES
ABOVE NORMAL BY WED.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
AT KCLT...LATEST RADAR TRENDS INDICATED THAT A CLUSTER OF WEAK
SHOWERS WERE MOVING EAST FROM THE GSP AREA...SOUTH OF THE STATE
LINE. THESE SHRA WERE TRIGGER NEAR A WEST TO EAST WARM FROM ACROSS
THE REGION. RECENT SPC ANALYSIS INDICATED THAT THE REGION THE SHRA
EXISTED WAS BECOMING INCREASINGLY LESS UNSTABLE...WITH CIN VALUES
AROUND 50 J/KG AND CAPE AROUND 250 J/KG. IT APPEARS THAT BASED ON
THE STABILITY PATTERN AND HISTORY OF OUTFLOW BOUNDARIES...NEW
CONVECTION WILL LIKELY FAVOR AREAS SOUTH OF THE RECENT ACTIVITY. I
WILL KEEP THE EARLY PORTION OF THE CLT TAF DRY AND VFR...WITH LIGHT
SOUTH WINDS. LATE TONIGHT...A MID LEVEL SHORT WAVE WILL RIPPLE OVER
THE SOUTHERN APPALACHIANS...AS A SFC LOW DEVELOPS ACROSS THE WESTERN
CAROLINAS. CIRCULATION AROUND THE LOW SHOULD RESULT IN A INCREASE IN
CAPE ACROSS THE PIEDMONT. I WILL CONTINUE TO INDICATE A PROB30
BETWEEN 9Z-12Z. THE SFC LOW SHOULD TRACK EAST THROUGH THE REST OF
THE DAY...RESULTING IN VEERING WEST TO NORTHWEST WINDS...WITH
MARGINAL GUSTS DURING THE LATE MORNING AND AFTERNOON.
ELSEWHERE...SHOWERS WILL REMAIN IN THE VICINITY OF GSP AND GMU
THROUGH 1Z. VFR WITH LIGHT SOUTH WINDS WILL REMAIN THROUGH TONIGHT.
BY SUNRISE...SFC LOW PRESSURE IS EXPECTED TO DEVELOP OVER THE REGION
AND WILL TRACK EAST THROUGH THE DAY...I WILL INDICATED VCSH AROUND
SUNRISE FOR MOST OF THE TAFS. IN THE WAKE OF THE LOW...CLOUD BASES
WILL RISE AND WINDS SHOULD VEER FROM THE NORTHWEST...WITH GUSTY
CONDITIONS FROM LATE MORNING THROUGH THE AFTERNOON.
OUTLOOK...DEEP HIGH PRESSURE WILL SETTLE OVER THE SOUTHEAST LATE
THIS WEEK AND REMAIN THROUGH TUESDAY. CONDITIONS SHOULD REMAIN
GENERALLY FAIR THROUGH THE PERIOD.
CONFIDENCE TABLE...
02-08Z 08-14Z 14-20Z 20-00Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 88% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 90% HIGH 97% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...SBK
NEAR TERM...NED
SHORT TERM...PM
LONG TERM...SBK
AVIATION...NED
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
1202 AM CDT TUE MAY 19 2015
.UPDATE...
UPDATED FOR 06Z AVIATION DISCUSSION.
&&
.AVIATION.../06Z TAFS/
GENERALLY VFR CONDITIONS CAN BE EXPECTED OVER THE NEXT 24 HOURS WITH
EXCEPTION OF KCSV WHERE MVFR/IFR VISIBILITIES AND CEILINGS WILL
CONTINUE OFF AND ON THROUGH 16Z WITH THE WORST CONDITIONS EXPECTED
BETWEEN 09Z-14Z.
&&
.PREV DISCUSSION... /ISSUED 844 PM CDT MON MAY 18 2015/
DISCUSSION...
FRONTAL BOUNDARY CURRENTLY STRETCHES FROM CENTRAL IN SOUTHWEST
THROUGH THE MO BOOTHEEL. THIS FEATURE WILL MOVE SOUTHEAST AND
PUSH ACROSS THE MID STATE LATE TONIGHT. FORCING ALONG THIS
BOUNDARY IS EXPECTED TO BE VERY WEAK. IN FACT...NVA LOOKS LIKE IT
WILL DOMINATE AFT 06Z. LATEST HRRR SHOWS A NARROW AND VERY LIGHT
DISORGANIZED BAND OF SHOWER ACTIVITY FOR LATE TONIGHT WHEN THE
FRONT MOVES THROUGH.
WILL GO AHEAD AND LOWER POPS. I WILL KEEP THE CHC CATEGORY GOING
OVER THE FAR SOUTHEAST FOR THE PRE 06Z TIMEFRAME. AFT 06Z...WILL
KEEP A SLIGHT CHANCE OF SHOWERS AND TSTMS GOING AREA WIDE.
OTW...WILL GO AHEAD AND ADD SOME PATCHY FOG ACROSS THE PLATEAU FOR
LATE TONIGHT. MODEL GUIDANCE LEANS TOWARD THE REDUCTION OF VSBYS. ALSO...
DRIER AIR IS NOT EXPECTED TO REACH THE PLAT PRIOR TO 12Z.
REMAINDER OF FCST APPEARS TO BE ON TRACK. COOLER AIR SHOULD REACH
INTO OUR NW COUNTIES BY SUNRISE AS THE FRONT MOVES THROUGH.
PREV DISCUSSION... /ISSUED 309 PM CDT MON MAY 18 2015/
DISCUSSION...
LATEST RADAR IMAGERY SHOWS SCATTERED SHOWERS AND A COUPLE OF
THUNDERSTORMS HAVE DEVELOPED THROUGHOUT THE MID STATE WITH THE
HEAVIEST CONCENTRATION SOUTH OF I-40. EXPECT THIS ACTIVITY TO
CONTINUE SPREADING EASTWARD THROUGH THE AFTERNOON. SHOWERS AND
STORMS WILL DIMINISH THIS EVENING AND TONIGHT AS A COLD FRONT
CURRENTLY IN SE MO AND S IL MOVES ACROSS THE AREA LATE TONIGHT
AND TOMORROW. MOISTURE WILL LINGER OVER SOUTHEASTERN ZONES
ON TUESDAY PRIOR TO FROPA SO COULD STILL SEE SOME ISOLATED SHOWERS
OR STORMS.
SOMEWHAT COOLER AND DRIER WEATHER IS OTHERWISE EXPECTED TUESDAY
INTO WEDNESDAY BEFORE THE NEXT SYSTEM APPROACHES FROM THE PLAINS.
NAM/ECMWF ARE MUCH MORE AGGRESSIVE THAN THE GFS IN BRINGING
NUMEROUS SHOWERS AND STORMS ACROSS THE AREA LATE WEDNESDAY INTO
EARLY THURSDAY. THEIR DEGREE OF MOISTURE RETURN FROM THE GULF MAY
BE TOO AGGRESSIVE...BUT WILL STILL GO AHEAD AND BUMP UP POPS FOR
THIS TIME FRAME. REMAINDER OF THE WEEK LOOKS QUITE NICE WITH LOWS
IN THE 50S AND HIGHS IN THE 70S.
GLOBAL MODELS AGREE THAT MIDDLE TENNESSEE WILL TRANSITION
INTO A WARMER BUT WETTER PATTERN OVER THE MEMORIAL DAY WEEKEND AS
THE PERSISTENT UPPER RIDGE OVER THE SOUTHEAST CONUS SHIFTS MORE
INTO THE ATLANTIC OCEAN...ALLOWING THE ACTIVE SUBTROPICAL JET TO
SHIFT FURTHER TO THE SOUTH OVER OUR REGION. THUS RAIN CHANCES WILL
INCREASE FROM SUNDAY ONWARD WITH HIGHS RETURNING INTO THE 80S AND
LOWS IN THE 60S.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1056 PM CDT Wed May 20 2015
.UPDATE...
The threat of severe thunderstorms has diminished across West
Central Texas. Most thunderstorms have moved south of our
counties. The old remaining thunderstorm cluster is over our
Northwest Hill Country counties, and the threat there has evolved
into more of a heavy rain threat, with the potential for local
flash flooding. Thus, we have canceled Severe Thunderstorm Watch
192 for all counties.
&&
.PREV DISCUSSION... /ISSUED 627 PM CDT Wed May 20 2015/
AVIATION...
/00Z TAFS/
Look for very challenging flight weather to continue for the next
24 hours. A cold front continue to move slowly south toward our
Interstate 10 corridor. North of the front low -winter-like stratus
has covered much of West Central Texas. Expect some improvement
tomorrow afternoon. Otherwise, plan for IFR to MVFR ceilings to
dominate.
PREV DISCUSSION... /ISSUED 552 PM CDT Wed May 20 2015/
UPDATE...
Thunderstorms, some severe, will continue to develop along or near
the cold front this evening. The cold front now extends near a
line from Barnhart...to Eldorado...to Brady. After coordination
with the Storm Prediction Central...we have issued Severe
Thunderstorm Watch number 192, which is valid until midnight CDT
tonight, for counties along and south of a line from Mertzon to
Brady. The latest Zone package headlines this watch for the
appropriate counties.
PREV DISCUSSION... /ISSUED 350 PM CDT Wed May 20 2015/
SHORT TERM...
(Tonight and Thursday)
A rather strong cold front has moved south of a San Angelo to
Coleman line this afternoon, dropping temperatures into the upper
50s and lower 60s across the Big Country. Low clouds and cold
advection north of the front has greatly reduced instability,
limiting the potential for diurnal convection. Ahead of the front,
temperatures have warmed into the lower 80s with dewpoints hanging
in the mid/upper 60s. Modified RAP soundings indicate SBCAPE values
on the order of 2000-2500 J/kg in the warm sector with effective
shear values exceeding 35 kts. This will support organized
convection this afternoon and during the evening hours, with the
primary focus along and south of the front. The primary concern is
for large hail and damaging winds. However, a tornadic storm cannot
be ruled out in the vicinity of this boundary.
Right moving supercell vectors are from the west and northwest at 10
to 15 mph. This slow storm motion and the presence of the
aforementioned cold front will support the potential for locally
heavy rainfall along the I-10 corridor tonight. Additional storms
will be possible overnight as isentropic ascent develops over the
frontal zone. As the front moves south overnight and early Thursday,
rain chances are expected to diminish during the morning hours.
However, shortwave ridging aloft will be shifting to the east as a
strong shortwave trough moves across the southern Rockies.
Increasing large scale ascent will promote the development of
scattered showers and thunderstorms during the afternoon hours.
Fortunately, the severe weather potential is expected to remain low
on Thursday. Much cooler temperatures are anticipated tomorrow, with
highs in the 60s across most of the area.
Johnson
LONG TERM...
(Thursday night through next Wednesday)
The main focus is with the severe weather and heavy rainfall
possibility for the Memorial Day holiday weekend.
Increased chance and coverage of showers and thunderstorms
is expected across our area Thursday night, with the arrival
of a stronger shortwave in southwest flow aloft. With subsidence
and advection of some drier mid-level air in the wake of this
departing shortwave, will have reduced chances for showers and
thunderstorms on Friday.
An upper low will move northeast into southeastern Utah Friday
night, with an upper trough trailing from the low across the
Desert Southwest. The main chance for showers and thunderstorms
Friday night will be overnight, and across our northwestern
counties, with the possibility of a weak embedded disturbance
out ahead of the main trough lifting northeast into far west
or northwest Texas.
The aforementioned upper trough will move slowly east across
Arizona and New Mexico over the holiday weekend. Given the
forecast strength of this system, will have increased potential
for severe weather with stronger instability and increased
vertical shear. Carrying higher PoPs over the weekend with the
highest rain chance on Saturday night. Heavy rainfall will also
be possible with repeat convective activity and precipitable
water values at or above 1.5 inches across much of our area.
The upper trough is progged to eventually lift northeast across
Texas, but the 12Z GFS and ECMWF differ on the timing.
Following departure of this system, drier and warmer conditions
look to be in store for our area as heights build aloft. May
have another upper trough approach from the southwestern states
next Wednesday, but keeping PoPs below mention with the
uncertainty at this time.
19
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 57 66 58 78 67 / 50 40 60 50 40
San Angelo 60 68 61 81 67 / 60 40 60 30 30
Junction 65 72 65 82 68 / 70 50 50 30 30
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
627 PM CDT Wed May 20 2015
.AVIATION...
/00Z TAFS/
Look for very challenging flight weather to continue for the next
24 hours. A cold front continue to move slowly south toward our
Interstate 10 corridor. North of the front low -winter-like stratus
has covered much of West Central Texas. Expect some improvement
tomorrow afternoon. Otherwise, plan for IFR to MVFR ceilings to
dominate.
&&
.PREV DISCUSSION... /ISSUED 552 PM CDT Wed May 20 2015/
UPDATE...
Thunderstorms, some severe, will continue to develop along or near
the cold front this evening. The cold front now extends near a
line from Barnhart...to Eldorado...to Brady. After coordination
with the Storm Prediction Central...we have issued Severe
Thunderstorm Watch number 192, which is valid until midnight CDT
tonight, for counties along and south of a line from Mertzon to
Brady. The latest Zone package headlines this watch for the
appropriate counties.
PREV DISCUSSION... /ISSUED 350 PM CDT Wed May 20 2015/
SHORT TERM...
(Tonight and Thursday)
A rather strong cold front has moved south of a San Angelo to
Coleman line this afternoon, dropping temperatures into the upper
50s and lower 60s across the Big Country. Low clouds and cold
advection north of the front has greatly reduced instability,
limiting the potential for diurnal convection. Ahead of the front,
temperatures have warmed into the lower 80s with dewpoints hanging
in the mid/upper 60s. Modified RAP soundings indicate SBCAPE values
on the order of 2000-2500 J/kg in the warm sector with effective
shear values exceeding 35 kts. This will support organized
convection this afternoon and during the evening hours, with the
primary focus along and south of the front. The primary concern is
for large hail and damaging winds. However, a tornadic storm cannot
be ruled out in the vicinity of this boundary.
Right moving supercell vectors are from the west and northwest at 10
to 15 mph. This slow storm motion and the presence of the
aforementioned cold front will support the potential for locally
heavy rainfall along the I-10 corridor tonight. Additional storms
will be possible overnight as isentropic ascent develops over the
frontal zone. As the front moves south overnight and early Thursday,
rain chances are expected to diminish during the morning hours.
However, shortwave ridging aloft will be shifting to the east as a
strong shortwave trough moves across the southern Rockies.
Increasing large scale ascent will promote the development of
scattered showers and thunderstorms during the afternoon hours.
Fortunately, the severe weather potential is expected to remain low
on Thursday. Much cooler temperatures are anticipated tomorrow, with
highs in the 60s across most of the area.
Johnson
LONG TERM...
(Thursday night through next Wednesday)
The main focus is with the severe weather and heavy rainfall
possibility for the Memorial Day holiday weekend.
Increased chance and coverage of showers and thunderstorms
is expected across our area Thursday night, with the arrival
of a stronger shortwave in southwest flow aloft. With subsidence
and advection of some drier mid-level air in the wake of this
departing shortwave, will have reduced chances for showers and
thunderstorms on Friday.
An upper low will move northeast into southeastern Utah Friday
night, with an upper trough trailing from the low across the
Desert Southwest. The main chance for showers and thunderstorms
Friday night will be overnight, and across our northwestern
counties, with the possibility of a weak embedded disturbance
out ahead of the main trough lifting northeast into far west
or northwest Texas.
The aforementioned upper trough will move slowly east across
Arizona and New Mexico over the holiday weekend. Given the
forecast strength of this system, will have increased potential
for severe weather with stronger instability and increased
vertical shear. Carrying higher PoPs over the weekend with the
highest rain chance on Saturday night. Heavy rainfall will also
be possible with repeat convective activity and precipitable
water values at or above 1.5 inches across much of our area.
The upper trough is progged to eventually lift northeast across
Texas, but the 12Z GFS and ECMWF differ on the timing.
Following departure of this system, drier and warmer conditions
look to be in store for our area as heights build aloft. May
have another upper trough approach from the southwestern states
next Wednesday, but keeping PoPs below mention with the
uncertainty at this time.
19
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 57 66 58 78 67 / 50 40 60 50 40
San Angelo 60 68 61 81 67 / 60 40 60 30 30
Junction 65 72 65 82 68 / 70 50 50 30 30
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
602 PM CDT Tue May 19 2015
.AVIATION...
/00Z TAFS/
Scattered showers and thunderstorms are affecting mainly the KABI
TAF this evening, where a VCTS group was included. Elsewhere,
convection should remain isolated. Stratus will move back into all
of the TAF sites after 06z, resulting in MVFR/IFR ceilings. VFR
ceilings should return to all sites by late morning or early
afternoon Wednesday. A cold front will approach KABI around 17z,
then slowly move south. Scattered showers and thunderstorms will
be possible along and behind the front, along with a wind shift to
the north at 8 to 12 knots.
&&
.PREV DISCUSSION... /ISSUED 353 PM CDT Tue May 19 2015/
SHORT TERM...
(Today and Tonight)
..Flash flood Watch has been extended until 10 PM CDT tonight for
the Big Country, Concho Valley, and Heartland...
The atmosphere is unstable this afternoon with RUC SB CAPES of
4000 J/KG. Severe storms are certainly possible this afternoon and
evening with the very strong instability. Strong storms were
already developing in the Trans Pecos and eastern Permian basin,
where less stratus was bringing more heating and instability.
These will likely move eastward into the Concho Valley this
evening. Scattered showers and thunderstorms were also developing
from Robert Lee to Brownwood, then northward into the Big Country.
With saturated soil conditions from Wednesday storms, the flash
flood watch has been extended to 10 PM CDT to catch the evening
storms. While coverage is expected to be less, excessive rainfall
rates from slow moving storms will likely cause localized flash
flooding on saturated soils. The atmosphere remains very moist,
with the SPC mesoanalysis page indicating very high precipitable
waters of 1.5 to 1.7 inches, which could bring very efficient
rainfall production.
Wednesday, a cold front will move into the Big Country in the
afternoon, and through the rest of West Central Texas overnight.
The atmosphere will remain unstable, and the front may be a
focus for severe thunderstorm development and localized flooding.
04
LONG TERM...
(Wednesday night through Tuesday)
The slow moving cold front is forecast to be near the I-20
corridor by Wednesday evening. A potent shortwave trough is
progged to be lifting northeast across Far West TX by this time,
increasing large scale forcing for ascent. Precipitable water
values will be in the 1.4 to 1.6" range, providing ample moisture
for convective development. As thunderstorms develop along/north
of this cold front, southerly winds above the boundary layer will
feed Gulf moisture into the complex. This will help propagate the
cold front slowly south across the CWA through Thursday morning,
with east to northeast surface winds developing across West
Central TX. Relatively weak winds aloft will result in slower
storm motions, enhancing the potential for locally heavy rainfall.
Another Flash Flood Watch may be required for this period.
The best rain chances shift to the southern zones on Thursday as
slightly drier air advects into the area behind this cold front.
Cooler temperatures are anticipated on Thursday, with highs in the
mid/upper 60s across the Big Country to the mid 70s along the I-10
corridor. The next shortwave trough is progged to approach West TX
Thursday and Thursday night. Rain chances ramp up accordingly, as
fairly widespread convection is anticipated across West Central
TX. Additional locally heavy rainfall will be possible during the
overnight hours.
Southerly winds are forecast to resume on Friday as the
aforementioned surface boundary washes out. Temperatures are
expected to respond by warming into the upper 70s to lower 80s.
Again, showers and thunderstorms will be possible, especially
during the afternoon and evening hours as thunderstorms over the
Permian Basin drift east into West Central TX.
The weather pattern over the weekend suggests a potential not only
for heavy rainfall, but also for severe weather. Southwest flow
aloft increases as a strong shortwave trough moves slowly east
across the Four Corners. Warmer surface temperatures, rich Gulf
moisture, and steepening mid-level lapse rates will increase the
potential for strong to severe thunderstorms.
In summary, showers and thunderstorms will be possible areawide
through Monday. The severe weather threat will be relatively low,
albeit still present. The potential for severe thunderstorms will
increase this weekend. Heavy rainfall will be the primary concern
through the period. Total rainfall amounts exceeding 4 inches are
possible.
Johnson
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 68 78 59 69 60 / 40 40 50 30 60
San Angelo 68 83 63 73 63 / 30 30 60 40 60
Junction 69 83 67 77 65 / 20 20 60 50 50
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH until 10 PM CDT this evening FOR THE FOLLOWING
ZONES: Brown...Callahan...Coke...Coleman...Concho...Fisher...
Haskell...Irion...Jones...McCulloch...Nolan...Runnels...San
Saba...Shackelford...Sterling...Taylor...Throckmorton...Tom
Green.
&&
$$
Daniels
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
353 PM CDT Tue May 19 2015
.SHORT TERM...
(Today and Tonight)
...Flash flood Watch has been extended until 10 PM CDT tonight for
the Big Country, Concho Valley, and Heartland...
The atmosphere is unstable this afternoon with RUC SB CAPES of
4000 J/KG. Severe storms are certainly possible this afternoon and
evening with the very strong instability. Strong storms were
already developing in the Trans Pecos and eastern Permian basin,
where less stratus was bringing more heating and instability.
These will likely move eastward into the Concho Valley this
evening. Scattered showers and thunderstorms were also developing
from Robert Lee to Brownwood, then northward into the Big Country.
With saturated soil conditions from Wednesday storms, the flash
flood watch has been extended to 10 PM CDT to catch the evening
storms. While coverage is expected to be less, excessive rainfall
rates from slow moving storms will likely cause localized flash
flooding on saturated soils. The atmosphere remains very moist,
with the SPC mesoanalysis page indicating very high precipitable
waters of 1.5 to 1.7 inches, which could bring very efficient
rainfall production.
Wednesday, a cold front will move into the Big Country in the
afternoon, and through the rest of West Central Texas overnight.
The atmosphere will remain unstable, and the front may be a
focus for severe thunderstorm development and localized flooding.
04
.LONG TERM...
(Wednesday night through Tuesday)
The slow moving cold front is forecast to be near the I-20
corridor by Wednesday evening. A potent shortwave trough is
progged to be lifting northeast across Far West TX by this time,
increasing large scale forcing for ascent. Precipitable water
values will be in the 1.4 to 1.6" range, providing ample moisture
for convective development. As thunderstorms develop along/north
of this cold front, southerly winds above the boundary layer will
feed Gulf moisture into the complex. This will help propagate the
cold front slowly south across the CWA through Thursday morning,
with east to northeast surface winds developing across West
Central TX. Relatively weak winds aloft will result in slower
storm motions, enhancing the potential for locally heavy rainfall.
Another Flash Flood Watch may be required for this period.
The best rain chances shift to the southern zones on Thursday as
slightly drier air advects into the area behind this cold front.
Cooler temperatures are anticipated on Thursday, with highs in the
mid/upper 60s across the Big Country to the mid 70s along the I-10
corridor. The next shortwave trough is progged to approach West TX
Thursday and Thursday night. Rain chances ramp up accordingly, as
fairly widespread convection is anticipated across West Central
TX. Additional locally heavy rainfall will be possible during the
overnight hours.
Southerly winds are forecast to resume on Friday as the
aforementioned surface boundary washes out. Temperatures are
expected to respond by warming into the upper 70s to lower 80s.
Again, showers and thunderstorms will be possible, especially
during the afternoon and evening hours as thunderstorms over the
Permian Basin drift east into West Central TX.
The weather pattern over the weekend suggests a potential not only
for heavy rainfall, but also for severe weather. Southwest flow
aloft increases as a strong shortwave trough moves slowly east
across the Four Corners. Warmer surface temperatures, rich Gulf
moisture, and steepening mid-level lapse rates will increase the
potential for strong to severe thunderstorms.
In summary, showers and thunderstorms will be possible areawide
through Monday. The severe weather threat will be relatively low,
albeit still present. The potential for severe thunderstorms will
increase this weekend. Heavy rainfall will be the primary concern
through the period. Total rainfall amounts exceeding 4 inches are
possible.
Johnson
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 68 78 59 69 60 / 40 40 50 30 60
San Angelo 68 83 63 73 63 / 30 30 60 40 60
Junction 69 83 67 77 65 / 20 20 60 50 50
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH until 10 PM CDT this evening FOR THE FOLLOWING
ZONES: Brown...Callahan...Coke...Coleman...Concho...Fisher...
Haskell...Irion...Jones...McCulloch...Nolan...Runnels...San
Saba...Shackelford...Sterling...Taylor...Throckmorton...Tom
Green.
&&
$$
04/25
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1258 PM CDT TUE MAY 19 2015
.AVIATION...
MVFR CIGS HAVE LIFTED IN SAN ANTONIO AND WILL WITHIN THE NEXT
COUPLE OF HOURS IN DRT AND AUS. SOUTHEASTERLY WINDS WILL GUST IN
THE LOW 20 KTS THIS AFTERNOON. THERE IS A SLIGHT CHANCE FOR
SHRA/TSRA THIS AFTERNOON...BUT PROBABILITY IS TOO LOW TO INCLUDE
IN THE TAFS. CIGS WILL LOWER AGAIN LATER TONIGHT AT ALL TERMINALS
EVENTUALLY DROPPING TO IFR IN AUSTIN AND SAN ANTONIO.
&&
.PREV DISCUSSION... /ISSUED 832 AM CDT TUE MAY 19 2015/
UPDATE...
MORNING SHOWER ACTIVITY IS INCREASING OVER THE NORTHERN COUNTIES
AS MOISTURE FEEDS INTO THE MCV IN THE FWD CWA. UPPED POPS A BIT IN
THIS REGION TO ACCOUNT FOR THIS NEW ACTIVITY. OTHERWISE...NO MAJOR
CHANGES WERE MADE TO THE FORECAST.
PREV DISCUSSION... /ISSUED 357 AM CDT TUE MAY 19 2015/
SHORT TERM (TODAY THROUGH WEDNESDAY)...
A SLOW MOVING MCS OVER WEST CENTRAL TX IS PRODUCING FLASH
FLOODING OVER THE SAN ANGELO AREA EARLY THIS MORNING. IN THE PAST
HOUR OR SO...THE SOUTHERN PORTION OF THE COMPLEX IS TAKING OVER
AND SHOWING A MORE FORWARD PROPAGATING TREND. HI-RES MODEL
SUGGESTED CORFIDI VECTORS SUGGEST THE STORMS TO REMAIN MOSTLY IN
THE FORECAST AREAS TO THE NORTH...BUT AS NOTED IN THE LATEST
SPENES AND FFGMPD DISCUSSIONS...DIFFLUENCE ALOFT IS CAUSING HI-
RES SOLUTIONS TO SLOW DOWN THE MOTION WITH THE SYSTEM EXPECTED
BECOME MORE DISORGANIZED AND SLOWER TOWARD DAYBREAK. UPSHEAR
PROPAGATION VECTORS AND MODEL DEPICTIONS OF AN INCREASING MOISTURE
TAP LATER IN THE MORNING WOULD SUGGEST THAT WE SHOULD CONSIDER AT
LEAST A MENTION OF LOCALLY HEAVY RAINFALL OVER THE NORTHERN HILL
COUNTRY INTO THE NORTHERN PART OF AUSTIN METRO FOR TODAY. SHOULD
THE HRRR CONTINUE TO ADVERTISE ROBUST STORM DEVELOPMENT FURTHER
DOWN THE I-35 CORRIDOR...WE MAY CONSIDER A RAISE OF POPS AND
EXPANSION OF THE HEAVY RAINFALL MENTION. OTHER HI-RES MODELS SHOW
POOR AGREEMENT ON THESE SHORT-TERM TRENDS...SO WITH LOW CONFIDENCE
WILL NOT EXPRESS A CONCERN OVER THE SATURATED SOILS OR THE NEED
FOR A FFA AT THIS TIME.
ASIDE FROM THE ACTIVITY AFFECTING NORTHERN COUNTIES TODAY...OVERALL
MODEL TRENDS HAVE BEEN CONSISTENT FOR A RELATIVELY STABLE FORECAST
FOR OUR SOUTHERN COUNTIES TODAY INTO WEDNESDAY. FORECAST WEAK 700
MB RIDGING SHOULD LEAD TO EVEN LESS CONVECTIVE ACTIVITY FOR
DAYTIME WEDNESDAY THAN TODAY.
LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...
THE RECOVERY TIME FOR SOUTH CENTRAL TX SOILS AND RIVERS IS SHORT
AS MODEL CONSENSUS NOW SHOWS GOOD AGREEMENT ON A COLD FRONT FOCUS
FOR MORE CONVECTION WEDNESDAY NIGHT INTO THURSDAY. THE MORE
DISTINCT INDICATION OF THE FRONT WOULD SUGGEST THAT THE FRONT
COULD POSSIBLY REMOVE SOME OF THE LOW LEVEL MOISTURE AND LEAD TO
LIGHTER RAINFALL TOTALS INITIALLY. SOME BRIEF HEAVY DOWNPOURS AND
A FEW STRONG STORMS COULD OCCUR WEDNESDAY EVENING GIVEN THE
EVENING TIMING EXPECTED.
MODELS SHOW HIGHEST QPF CONCENTRATIONS SHIFTING TO WESTERN
COUNTIES BY LATE THURSDAY WHERE ELEVATED MOISTURE POOLING IS
PINNED AGAINST THE HIGHER TERRAIN TO THE WEST. THE WEAK MID-LEVEL
RIDGING IS CLEARS OUT BY THEN...AND OVERRUNNING OF THE UNSTABLE
MOIST AIR SHOULD BE ABLE TO SPREAD EAST ACROSS ALL AREAS THURSDAY
NIGHT INTO FRIDAY WITH MULTIPLE ROUNDS OF ELEVATED STORMS THAT
TRANSITION INTO DEEPER CONVECTION BY FRIDAY. AT SOME POINT A FLASH
FLOOD WATCH WILL PROBABLY BE ISSUED...POSSIBLY AS EARLY AS
THURSDAY NIGHT. THE HEAVIEST RAINFALL CONCERN IS SAVED FOR
MEMORIAL DAY WEEKEND...AND WITH ALL MODELS SHOWING A GOOD PATTERN
FOR A SLOW MOVING COMPLEX ENHANCED BY A HIGH AMPLITUDE UPPER
TROUGH...WILL SHOW MOST OF THE ATTENTION FOR LATE SATURDAY THROUGH
LATE SUNDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 72 86 70 80 68 / 30 20 30 40 40
AUSTIN BERGSTROM INTL AIRPORT 71 85 69 80 67 / 20 20 30 40 40
NEW BRAUNFELS MUNI AIRPORT 71 85 71 81 68 / 20 20 20 40 30
BURNET MUNI AIRPORT 70 84 67 76 65 / 30 20 40 40 50
DEL RIO INTL AIRPORT 73 86 71 82 69 / 20 20 50 50 60
GEORGETOWN MUNI AIRPORT 71 84 68 77 66 / 20 20 30 40 40
HONDO MUNI AIRPORT 71 85 71 82 69 / 30 20 40 40 40
SAN MARCOS MUNI AIRPORT 72 85 70 80 68 / 20 20 20 40 40
LA GRANGE - FAYETTE REGIONAL 73 86 71 82 70 / 10 20 20 50 40
SAN ANTONIO INTL AIRPORT 72 85 72 81 69 / 30 20 30 40 40
STINSON MUNI AIRPORT 72 87 73 82 70 / 20 20 30 40 40
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...05/TB3
SYNOPTIC/GRIDS...HAMPSHIRE
PUBLIC SERVICE/DATA COLLECTION...TREADWAY
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
832 AM CDT TUE MAY 19 2015
.UPDATE...
MORNING SHOWER ACTIVITY IS INCREASING OVER THE NORTHERN COUNTIES
AS MOISTURE FEEDS INTO THE MCV IN THE FWD CWA. UPPED POPS A BIT IN
THIS REGION TO ACCOUNT FOR THIS NEW ACTIVITY. OTHERWISE...NO MAJOR
CHANGES WERE MADE TO THE FORECAST.
&&
.PREV DISCUSSION... /ISSUED 645 AM CDT TUE MAY 19 2015/
DISCUSSION...12Z AVIATION BELOW.
AVIATION...BKN-OVC MVFR TO IFR CEILINGS WITH STRATUS THIS
MORNING ACROSS SOUTH-CENTRAL TEXAS. REMNANTS OF OVERNIGHT
CONVECTIVE COMPLEX IS PASSING NORTH OF THE CWA THIS MORNING.
A FEW SHRA AND ISOLATED TSTMS POSSIBLE THROUGH THE MORNING ACROSS
THE HILL COUNTRY AND CENTRAL TEXAS NEAR AUS...FEEDING INTO WHAT IS
LEFT OF THE MCV FARTHER TO THE NORTH. OTHERWISE...CEILINGS SLOWLY
RISING AFTER 16Z AND EVENTUALLY BECOMING VFR 18Z-20Z.
MVFR CEILINGS RE-DEVELOPING 03Z-05Z AUS/SAT/SSF AND BECOMING IFR
06Z-08Z. MVFR CEILINGS RE-DEVELOP AT DRT 06Z-08Z.
PREV DISCUSSION... /ISSUED 357 AM CDT TUE MAY 19 2015/
SHORT TERM (TODAY THROUGH WEDNESDAY)...
A SLOW MOVING MCS OVER WEST CENTRAL TX IS PRODUCING FLASH
FLOODING OVER THE SAN ANGELO AREA EARLY THIS MORNING. IN THE PAST
HOUR OR SO...THE SOUTHERN PORTION OF THE COMPLEX IS TAKING OVER
AND SHOWING A MORE FORWARD PROPAGATING TREND. HI-RES MODEL
SUGGESTED CORFIDI VECTORS SUGGEST THE STORMS TO REMAIN MOSTLY IN
THE FORECAST AREAS TO THE NORTH...BUT AS NOTED IN THE LATEST
SPENES AND FFGMPD DISCUSSIONS...DIFFLUENCE ALOFT IS CAUSING HI-
RES SOLUTIONS TO SLOW DOWN THE MOTION WITH THE SYSTEM EXPECTED
BECOME MORE DISORGANIZED AND SLOWER TOWARD DAYBREAK. UPSHEAR
PROPAGATION VECTORS AND MODEL DEPICTIONS OF AN INCREASING MOISTURE
TAP LATER IN THE MORNING WOULD SUGGEST THAT WE SHOULD CONSIDER AT
LEAST A MENTION OF LOCALLY HEAVY RAINFALL OVER THE NORTHERN HILL
COUNTRY INTO THE NORTHERN PART OF AUSTIN METRO FOR TODAY. SHOULD
THE HRRR CONTINUE TO ADVERTISE ROBUST STORM DEVELOPMENT FURTHER
DOWN THE I-35 CORRIDOR...WE MAY CONSIDER A RAISE OF POPS AND
EXPANSION OF THE HEAVY RAINFALL MENTION. OTHER HI-RES MODELS SHOW
POOR AGREEMENT ON THESE SHORT-TERM TRENDS...SO WITH LOW CONFIDENCE
WILL NOT EXPRESS A CONCERN OVER THE SATURATED SOILS OR THE NEED
FOR A FFA AT THIS TIME.
ASIDE FROM THE ACTIVITY AFFECTING NORTHERN COUNTIES TODAY...OVERALL
MODEL TRENDS HAVE BEEN CONSISTENT FOR A RELATIVELY STABLE FORECAST
FOR OUR SOUTHERN COUNTIES TODAY INTO WEDNESDAY. FORECAST WEAK 700
MB RIDGING SHOULD LEAD TO EVEN LESS CONVECTIVE ACTIVITY FOR
DAYTIME WEDNESDAY THAN TODAY.
LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...
THE RECOVERY TIME FOR SOUTH CENTRAL TX SOILS AND RIVERS IS SHORT
AS MODEL CONSENSUS NOW SHOWS GOOD AGREEMENT ON A COLD FRONT FOCUS
FOR MORE CONVECTION WEDNESDAY NIGHT INTO THURSDAY. THE MORE
DISTINCT INDICATION OF THE FRONT WOULD SUGGEST THAT THE FRONT
COULD POSSIBLY REMOVE SOME OF THE LOW LEVEL MOISTURE AND LEAD TO
LIGHTER RAINFALL TOTALS INITIALLY. SOME BRIEF HEAVY DOWNPOURS AND
A FEW STRONG STORMS COULD OCCUR WEDNESDAY EVENING GIVEN THE
EVENING TIMING EXPECTED.
MODELS SHOW HIGHEST QPF CONCENTRATIONS SHIFTING TO WESTERN
COUNTIES BY LATE THURSDAY WHERE ELEVATED MOISTURE POOLING IS
PINNED AGAINST THE HIGHER TERRAIN TO THE WEST. THE WEAK MID-LEVEL
RIDGING IS CLEARS OUT BY THEN...AND OVERRUNNING OF THE UNSTABLE
MOIST AIR SHOULD BE ABLE TO SPREAD EAST ACROSS ALL AREAS THURSDAY
NIGHT INTO FRIDAY WITH MULTIPLE ROUNDS OF ELEVATED STORMS THAT
TRANSITION INTO DEEPER CONVECTION BY FRIDAY. AT SOME POINT A FLASH
FLOOD WATCH WILL PROBABLY BE ISSUED...POSSIBLY AS EARLY AS
THURSDAY NIGHT. THE HEAVIEST RAINFALL CONCERN IS SAVED FOR
MEMORIAL DAY WEEKEND...AND WITH ALL MODELS SHOWING A GOOD PATTERN
FOR A SLOW MOVING COMPLEX ENHANCED BY A HIGH AMPLITUDE UPPER
TROUGH...WILL SHOW MOST OF THE ATTENTION FOR LATE SATURDAY THROUGH
LATE SUNDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 85 71 86 69 81 / 50 20 20 40 30
AUSTIN BERGSTROM INTL AIRPORT 85 71 85 69 82 / 40 20 20 30 40
NEW BRAUNFELS MUNI AIRPORT 85 71 85 70 82 / 30 20 20 30 40
BURNET MUNI AIRPORT 82 70 84 67 78 / 50 30 20 40 30
DEL RIO INTL AIRPORT 87 72 86 70 83 / 30 20 20 50 40
GEORGETOWN MUNI AIRPORT 84 71 84 67 79 / 50 20 20 40 30
HONDO MUNI AIRPORT 86 71 86 71 83 / 30 20 20 40 40
SAN MARCOS MUNI AIRPORT 85 71 85 70 82 / 30 20 20 30 40
LA GRANGE - FAYETTE REGIONAL 85 73 86 71 83 / 30 20 20 20 40
SAN ANTONIO INTL AIRPORT 85 72 86 71 82 / 30 20 20 30 40
STINSON MUNI AIRPORT 87 73 87 72 84 / 30 20 20 30 40
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...TB3
SYNOPTIC/GRIDS...HAMPSHIRE
PUBLIC SERVICE/DATA COLLECTION...TREADWAY
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
645 AM CDT TUE MAY 19 2015
.DISCUSSION...12Z AVIATION BELOW.
&&
.AVIATION...BKN-OVC MVFR TO IFR CEILINGS WITH STRATUS THIS
MORNING ACROSS SOUTH-CENTRAL TEXAS. REMNANTS OF OVERNIGHT
CONVECTIVE COMPLEX IS PASSING NORTH OF THE CWA THIS MORNING.
A FEW SHRA AND ISOLATED TSTMS POSSIBLE THROUGH THE MORNING ACROSS
THE HILL COUNTRY AND CENTRAL TEXAS NEAR AUS...FEEDING INTO WHAT IS
LEFT OF THE MCV FARTHER TO THE NORTH. OTHERWISE...CEILINGS SLOWLY
RISING AFTER 16Z AND EVENTUALLY BECOMING VFR 18Z-20Z.
MVFR CEILINGS RE-DEVELOPING 03Z-05Z AUS/SAT/SSF AND BECOMING IFR
06Z-08Z. MVFR CEILINGS RE-DEVELOP AT DRT 06Z-08Z.
&&
.PREV DISCUSSION... /ISSUED 357 AM CDT TUE MAY 19 2015/
SHORT TERM (TODAY THROUGH WEDNESDAY)...
A SLOW MOVING MCS OVER WEST CENTRAL TX IS PRODUCING FLASH
FLOODING OVER THE SAN ANGELO AREA EARLY THIS MORNING. IN THE PAST
HOUR OR SO...THE SOUTHERN PORTION OF THE COMPLEX IS TAKING OVER
AND SHOWING A MORE FORWARD PROPAGATING TREND. HI-RES MODEL
SUGGESTED CORFIDI VECTORS SUGGEST THE STORMS TO REMAIN MOSTLY IN
THE FORECAST AREAS TO THE NORTH...BUT AS NOTED IN THE LATEST
SPENES AND FFGMPD DISCUSSIONS...DIFFLUENCE ALOFT IS CAUSING HI-
RES SOLUTIONS TO SLOW DOWN THE MOTION WITH THE SYSTEM EXPECTED
BECOME MORE DISORGANIZED AND SLOWER TOWARD DAYBREAK. UPSHEAR
PROPAGATION VECTORS AND MODEL DEPICTIONS OF AN INCREASING MOISTURE
TAP LATER IN THE MORNING WOULD SUGGEST THAT WE SHOULD CONSIDER AT
LEAST A MENTION OF LOCALLY HEAVY RAINFALL OVER THE NORTHERN HILL
COUNTRY INTO THE NORTHERN PART OF AUSTIN METRO FOR TODAY. SHOULD
THE HRRR CONTINUE TO ADVERTISE ROBUST STORM DEVELOPMENT FURTHER
DOWN THE I-35 CORRIDOR...WE MAY CONSIDER A RAISE OF POPS AND
EXPANSION OF THE HEAVY RAINFALL MENTION. OTHER HI-RES MODELS SHOW
POOR AGREEMENT ON THESE SHORT-TERM TRENDS...SO WITH LOW CONFIDENCE
WILL NOT EXPRESS A CONCERN OVER THE SATURATED SOILS OR THE NEED
FOR A FFA AT THIS TIME.
ASIDE FROM THE ACTIVITY AFFECTING NORTHERN COUNTIES TODAY...OVERALL
MODEL TRENDS HAVE BEEN CONSISTENT FOR A RELATIVELY STABLE FORECAST
FOR OUR SOUTHERN COUNTIES TODAY INTO WEDNESDAY. FORECAST WEAK 700
MB RIDGING SHOULD LEAD TO EVEN LESS CONVECTIVE ACTIVITY FOR
DAYTIME WEDNESDAY THAN TODAY.
LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...
THE RECOVERY TIME FOR SOUTH CENTRAL TX SOILS AND RIVERS IS SHORT
AS MODEL CONSENSUS NOW SHOWS GOOD AGREEMENT ON A COLD FRONT FOCUS
FOR MORE CONVECTION WEDNESDAY NIGHT INTO THURSDAY. THE MORE
DISTINCT INDICATION OF THE FRONT WOULD SUGGEST THAT THE FRONT
COULD POSSIBLY REMOVE SOME OF THE LOW LEVEL MOISTURE AND LEAD TO
LIGHTER RAINFALL TOTALS INITIALLY. SOME BRIEF HEAVY DOWNPOURS AND
A FEW STRONG STORMS COULD OCCUR WEDNESDAY EVENING GIVEN THE
EVENING TIMING EXPECTED.
MODELS SHOW HIGHEST QPF CONCENTRATIONS SHIFTING TO WESTERN
COUNTIES BY LATE THURSDAY WHERE ELEVATED MOISTURE POOLING IS
PINNED AGAINST THE HIGHER TERRAIN TO THE WEST. THE WEAK MID-LEVEL
RIDGING IS CLEARS OUT BY THEN...AND OVERRUNNING OF THE UNSTABLE
MOIST AIR SHOULD BE ABLE TO SPREAD EAST ACROSS ALL AREAS THURSDAY
NIGHT INTO FRIDAY WITH MULTIPLE ROUNDS OF ELEVATED STORMS THAT
TRANSITION INTO DEEPER CONVECTION BY FRIDAY. AT SOME POINT A FLASH
FLOOD WATCH WILL PROBABLY BE ISSUED...POSSIBLY AS EARLY AS
THURSDAY NIGHT. THE HEAVIEST RAINFALL CONCERN IS SAVED FOR
MEMORIAL DAY WEEKEND...AND WITH ALL MODELS SHOWING A GOOD PATTERN
FOR A SLOW MOVING COMPLEX ENHANCED BY A HIGH AMPLITUDE UPPER
TROUGH...WILL SHOW MOST OF THE ATTENTION FOR LATE SATURDAY THROUGH
LATE SUNDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 85 71 86 69 81 / 40 20 20 40 30
AUSTIN BERGSTROM INTL AIRPORT 85 71 85 69 82 / 30 20 20 30 40
NEW BRAUNFELS MUNI AIRPORT 85 71 85 70 82 / 20 20 20 30 40
BURNET MUNI AIRPORT 82 70 84 67 78 / 40 30 20 40 30
DEL RIO INTL AIRPORT 87 72 86 70 83 / 30 20 20 50 40
GEORGETOWN MUNI AIRPORT 84 71 84 67 79 / 40 20 20 40 30
HONDO MUNI AIRPORT 86 71 86 71 83 / 30 20 20 40 40
SAN MARCOS MUNI AIRPORT 85 71 85 70 82 / 30 20 20 30 40
LA GRANGE - FAYETTE REGIONAL 85 73 86 71 83 / 30 20 20 20 40
SAN ANTONIO INTL AIRPORT 85 72 86 71 82 / 30 20 20 30 40
STINSON MUNI AIRPORT 87 73 87 72 84 / 20 20 20 30 40
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...76
SYNOPTIC/GRIDS...18
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
357 AM CDT TUE MAY 19 2015
.SHORT TERM (TODAY THROUGH WEDNESDAY)...
A SLOW MOVING MCS OVER WEST CENTRAL TX IS PRODUCING FLASH
FLOODING OVER THE SAN ANGELO AREA EARLY THIS MORNING. IN THE PAST
HOUR OR SO...THE SOUTHERN PORTION OF THE COMPLEX IS TAKING OVER
AND SHOWING A MORE FORWARD PROPAGATING TREND. HI-RES MODEL
SUGGESTED CORFIDI VECTORS SUGGEST THE STORMS TO REMAIN MOSTLY IN
THE FORECAST AREAS TO THE NORTH...BUT AS NOTED IN THE LATEST
SPENES AND FFGMPD DISCUSSIONS...DIFFLUENCE ALOFT IS CAUSING HI-
RES SOLUTIONS TO SLOW DOWN THE MOTION WITH THE SYSTEM EXPECTED
BECOME MORE DISORGANIZED AND SLOWER TOWARD DAYBREAK. UPSHEAR
PROPAGATION VECTORS AND MODEL DEPICTIONS OF AN INCREASING MOISTURE
TAP LATER IN THE MORNING WOULD SUGGEST THAT WE SHOULD CONSIDER AT
LEAST A MENTION OF LOCALLY HEAVY RAINFALL OVER THE NORTHERN HILL
COUNTRY INTO THE NORTHERN PART OF AUSTIN METRO FOR TODAY. SHOULD
THE HRRR CONTINUE TO ADVERTISE ROBUST STORM DEVELOPMENT FURTHER
DOWN THE I-35 CORRIDOR...WE MAY CONSIDER A RAISE OF POPS AND
EXPANSION OF THE HEAVY RAINFALL MENTION. OTHER HI-RES MODELS SHOW
POOR AGREEMENT ON THESE SHORT-TERM TRENDS...SO WITH LOW CONFIDENCE
WILL NOT EXPRESS A CONCERN OVER THE SATURATED SOILS OR THE NEED
FOR A FFA AT THIS TIME.
ASIDE FROM THE ACTIVITY AFFECTING NORTHERN COUNTIES TODAY...OVERALL
MODEL TRENDS HAVE BEEN CONSISTENT FOR A RELATIVELY STABLE FORECAST
FOR OUR SOUTHERN COUNTIES TODAY INTO WEDNESDAY. FORECAST WEAK 700
MB RIDGING SHOULD LEAD TO EVEN LESS CONVECTIVE ACTIVITY FOR
DAYTIME WEDNESDAY THAN TODAY.
&&
.LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...
THE RECOVERY TIME FOR SOUTH CENTRAL TX SOILS AND RIVERS IS SHORT
AS MODEL CONSENSUS NOW SHOWS GOOD AGREEMENT ON A COLD FRONT FOCUS
FOR MORE CONVECTION WEDNESDAY NIGHT INTO THURSDAY. THE MORE
DISTINCT INDICATION OF THE FRONT WOULD SUGGEST THAT THE FRONT
COULD POSSIBLY REMOVE SOME OF THE LOW LEVEL MOISTURE AND LEAD TO
LIGHTER RAINFALL TOTALS INITIALLY. SOME BRIEF HEAVY DOWNPOURS AND
A FEW STRONG STORMS COULD OCCUR WEDNESDAY EVENING GIVEN THE
EVENING TIMING EXPECTED.
MODELS SHOW HIGHEST QPF CONCENTRATIONS SHIFTING TO WESTERN
COUNTIES BY LATE THURSDAY WHERE ELEVATED MOISTURE POOLING IS
PINNED AGAINST THE HIGHER TERRAIN TO THE WEST. THE WEAK MID-LEVEL
RIDGING IS CLEARS OUT BY THEN...AND OVERRUNNING OF THE UNSTABLE
MOIST AIR SHOULD BE ABLE TO SPREAD EAST ACROSS ALL AREAS THURSDAY
NIGHT INTO FRIDAY WITH MULTIPLE ROUNDS OF ELEVATED STORMS THAT
TRANSITION INTO DEEPER CONVECTION BY FRIDAY. AT SOME POINT A FLASH
FLOOD WATCH WILL PROBABLY BE ISSUED...POSSIBLY AS EARLY AS
THURSDAY NIGHT. THE HEAVIEST RAINFALL CONCERN IS SAVED FOR
MEMORIAL DAY WEEKEND...AND WITH ALL MODELS SHOWING A GOOD PATTERN
FOR A SLOW MOVING COMPLEX ENHANCED BY A HIGH AMPLITUDE UPPER
TROUGH...WILL SHOW MOST OF THE ATTENTION FOR LATE SATURDAY THROUGH
LATE SUNDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 85 71 86 69 81 / 40 20 20 40 30
AUSTIN BERGSTROM INTL AIRPORT 85 71 85 69 82 / 30 20 20 30 40
NEW BRAUNFELS MUNI AIRPORT 85 71 85 70 82 / 20 20 20 30 40
BURNET MUNI AIRPORT 82 70 84 67 78 / 40 30 20 40 30
DEL RIO INTL AIRPORT 87 72 86 70 83 / 30 20 20 50 40
GEORGETOWN MUNI AIRPORT 84 71 84 67 79 / 40 20 20 40 30
HONDO MUNI AIRPORT 86 71 86 71 83 / 30 20 20 40 40
SAN MARCOS MUNI AIRPORT 85 71 85 70 82 / 30 20 20 30 40
LA GRANGE - FAYETTE REGIONAL 85 73 86 71 83 / 30 20 20 20 40
SAN ANTONIO INTL AIRPORT 85 72 86 71 82 / 30 20 20 30 40
STINSON MUNI AIRPORT 87 73 87 72 84 / 20 20 20 30 40
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...76
SYNOPTIC/GRIDS...18
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
358 PM EDT TUE MAY 19 2015
.SYNOPSIS...
HIGH PRESSURE OVER THE OHIO VALLEY AND UPPER MIDWEST WILL MOVE
EAST TONIGHT...INTRODUCING A MUCH DRIER AIRMASS TO THE MID
ATLANTIC REGION FOR WEDNESDAY. AN UPPER LEVEL DISTURBANCE WILL
PASS ACROSS THE REGION THURSDAY...FOLLOWED BY TRANQUIL WEATHER
FOR FRIDAY AND SATURDAY COURTESY OF DRY HIGH PRESSURE.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 345 PM EDT TUESDAY...
CHANGE IN AIRMASS IS UNDERWAY WITH FALLING DEWPOINTS. SURFACE COLD
FRONT HAS MOVED EAST OF THE MOUNTAINS. ANY SHOWER ACTIVITY WILL
QUICKLY MOVE EAST THIS EVENING AND AWAY FROM THE FORECAST AREA.
TREND THROUGH THE EVENING WILL BE FOR CLEARING SKIES WITH FAIR/DRY
WEATHER EXPECTED THE NEXT 24 HOURS PER HIGH PRESSURE WHICH IS
BUILDING INTO THE MID ATLANTIC REGION FROM THE NORTHWEST.
TEMPERATURES TONIGHT AND WEDNESDAY WILL ACTUALLY RESEMBLE
SOMETHING CLOSE TO NORMAL WITH 50S FOR LOWS AND 70S TO AROUND 80
FOR HIGHS. WITH LOW DEWPOINTS FORECAST FOR WEDNESDAY...AFTERNOON
HUMIDITY MINIMUMS MAY DIP TO BETWEEN 25-30 PERCENT.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
AS OF 330 PM EDT TUESDAY...
A GOOD DEGREE OF UNCERTAINTY IN THE FORECAST EARLY IN THE SHORT TERM
PERIOD AS GUIDANCE DIFFERENCES ON HANDLING OF SURFACE FEATURES...
WHICH WILL HAVE AN IMPACT ON RAIN CHANCES WEDNESDAY NIGHT THROUGH
THURSDAY. SHORT WAVE ENERGY EJECTING OUT OF AN WESTERN UPPER LEVEL
RIDGE WILL COMBINE WITH SOME SHORT WAVE ENERGY ROTATING AROUND AN
UPPER TROF OVER THE GREAT LAKES AND HEAD IN OUR DIRECTION. THIS
WILL HELP DRIVE DEVELOPMENT OF A SURFACE LOW OVER THE SOUTHEAST US
LATE WEDNESDAY NIGHT...WHICH WILL THEN MOVE OFF THE MIDDLE ATLANTIC
COAST BY THURSDAY NIGHT. THE OPERATIONAL GFS RUN IS ON BOARD WITH
OTHER MODELS IN HANDLING OF DYNAMICS BUT IS MUCH LESS AGGRESSIVE AND
FURTHER EAST IN DEVELOPING PRECIPITATION OVER THE AREA. OTHER
OPERATIONAL RUNS AND ENSEMBLES DO GENERATE A MUCH MORE COHESIVE
PRECIPITATION SHIELD NORTH AND WEST OF THE LOW ASSOCIATED WITH
ENHANCED LIFT IN DEFORMATION AREAS AND RR QUAD OF UPPER JET WHERE WE
NORMALLY EXPECT TO SEE THESE FEATURES. THUS WILL LEAN TOWARD THE
WETTER GUIDANCE AND RAMP POPS UP TO HIGH CHANCE FOR MOST AREAS BY
LATE WED NIGHT AND THROUGH THURSDAY. BELIEVE THUNDER CHANCES WILL
STAY JUST SOUTH OF THE FOOTHILLS/PIEDMONT OF NC SINCE WE WILL BE IN
A COOLER AND MORE STABLE ENVIRONMENT WITH THE LOW TRACKING TO OUR
SOUTH. AS THE LOW DEPARTS THURSDAY NIGHT...HIGH PRESSURE WILL BUILD
IN FROM THE UPPER MIDWEST AND WE WILL SEE STEADILY IMPROVING
CONDITIONS WITH QUIET WEATHER EXPECTED AS WE HEAD INTO THE WEEKEND.
TEMPERATURES WILL START OFF A BIT COOL ON THURSDAY WITH
PRECIPITATION ON THE COOL SIDE OF THE LOW...BUT VALUES WILL REBOUND
TO SEASONAL LEVELS WITH GENERALLY UPPER 60S/AROUND 70 BLUE RIDGE
WEST AND LOW TO MID 70S EAST.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 330 PM EDT TUESDAY...
UPPER PATTERN WILL BE DEVELOPING A LARGE TROF OVER THE EASTERN US
DURING THE EXTENDED PERIOD...WITH A BERMUDA HIGH OFF THE COAST. THIS
WILL GIVE US A VERY COMFORTABLE AND PLEASANT SATURDAY FOLLOWED BY
HEAT AND HUMIDITY MOVING BACK INTO THE REGION BY SUNDAY...WITH THE
TRULY UNCOMFORTABLE CONDITIONS HOLDING OFF UNTIL THE FIRST PART OF
NEXT WEEK. HOWEVER THE CHANCES FOR SHOWERS AND THUNDERSTORMS WILL BE
ONLY MODEST AS SIGNIFICANT DYNAMIC FORCING WILL BE ABSENT...LEAVING
US TO RELY ON OROGRAPHIC FORCING FROM THE BLUE RIDGE WEST TO FOCUS
LIFT AND GENERATE SOME CONVECTIVE ACTIVITY. PWATS WILL ONCE AGAIN BE
RISING ABOVE ONE INCH SO THE POSSIBILITY OF LOCAL DOWNPOURS WILL BE
INCREASING. BY TUESDAY A COLD FRONT WILL BE APPROACHING FROM THE
WEST AND LOOKS TO BRING GREATER COVERAGE OF PRECIPITATION TO THE
REGION TUESDAY AFTERNOON AND EVENING. AFTER A COMFORTABLE
SATURDAY...EXPECT RISING TEMPERATURES TO BE ABOUT 10 DEGREES ABOVE
NORMAL AS WE HEAD INTO NEXT WEEK.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
AS OF 200 PM EDT TUESDAY...
SCATTERED SHOWERS/STORMS OVER THE AREA THIS EVENING WILL
DISSIPATE BY SUNSET. A MUCH DRIER AIRMASS WILL ADVECT INTO THE
FORECAST AREA OVERNIGHT AND WEDNESDAY. THIS DRY AIRMASS WILL
PREVENT DEEP CONVECTION WEDNESDAY.
ASIDE FROM THE SHOWER ACTIVITY THIS EVENING ANTICIPATING MAINLY
VFR THROUGH THE VALID TAF PERIOD. SOME OF THE MODELS INDICATE THAT
A SHALLOW LAYER OF MOISTURE MAY GET TRAPPED UP AGAINST THE WEST
SIDE OF THE APPALACHIANS LATE TONIGHT. THIS MAY RESULT IN A PERIOD
OF LOW STRATUS 4-8FT AGL VCNTY OF KBLF EARLY WEDNESDAY MORNING.
ANY LOW CLOUD THAT DOES FORM SHOULD DISSIPATE QUICKLY WEDNESDAY
MORNING.
EXTENDED AVIATION DISCUSSION...
AN UPPER LEVEL DISTURBANCE WILL LIKELY BRING SOME MVFR CEILINGS
AND SHOWERS BACK INTO THE AREA THURSDAY...MOVING OUT FRIDAY
MORNING...WITH VFR CONDITIONS RETURNING FRIDAY AFTERNOON AND
SATURDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PM
NEAR TERM...PM
SHORT TERM...MBS
LONG TERM...MBS
AVIATION...PM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
217 AM EDT TUE MAY 19 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE EAST ACROSS THE OHIO VALLEY OVERNIGHT...
THEN CROSS THE MID ATLANTIC REGION TUESDAY. SOME ADDITIONAL SHOWERS
ARE POSSIBLE IN THE WEST OVERNIGHT...WITH SHOWERS AND A FEW STORMS
POSSIBLE ON TUESDAY...ESPECIALLY ACROSS THE SOUTHEAST PART OF THE
REGION. ONCE THE FRONT PASSES EAST OF THE AREA TUESDAY...COOLER...DRIER
AIR WILL FILTER INTO THE REGION FOR MID WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 935 PM EDT MONDAY...
MUCH OF THE SHOWER AND THUNDERSTORM ACTIVITY HAS ENDED ACROSS THE
REGION. WHAT REMAINS IS MAINLY ACROSS BUCKINGHAM COUNTY VA...BUT
THERE TOO...THE PRECIPITATION WILL CONTINUE TO DISSIPATE. ISOLATED
TO SCATTERED SHOWERS ARE EXPECTED TO RETURN TO WESTERN PARTS OF
THE AREA AFTER MIDNIGHT IN ADVANCE OF AN APPROACHING COLD FRONT.
HAVE MADE MINOR ADJUSTMENTS UPWARD TO THE EXPECTED LOW
TEMPERATURES ACROSS THE EASTERN PORTIONS OF THE AREA. PATCHY FOG
IS EXPECTED TO DEVELOP OVERNIGHT...WITH AREAS THAT RECEIVED RAIN
TODAY...RIVER VALLEYS AND MOUNTAIN VALLEYS THE MOST LIKELY AREAS
TO EXPERIENCE SOME. NO OTHER NOTABLE CHANGES WERE MADE AT THIS
TIME.
AS OF 640 PM EDT MONDAY...
NO MAJOR CHANGES TO THE FORECAST AS WE HEAD INTO THE EVENING
HOURS. WE STILL EXPECT SCATTERED SHOWERS AND SOME STORMS ACROSS
MUCH OF THE REGION. WHAT DID CHANGE WAS THE FOCUS FOR WHERE THE
BEST CHANCES WOULD BE IN THE NEXT COUPLE OF HOURS BASED UPON WHERE
THE GREATEST CONCENTRATION IS CURRENTLY LOCATED...FROM FRANKLIN
COUNTY VA SOUTHWEST TO AROUND PILOT MOUNTAIN IN NORTH
CAROLINA...AND WEST TO THE GRAYSON HIGHLANDS OF SOUTHWEST
VIRGINIA. ALSO...ANOTHER GENEROUS REGION OF PRECIPITATION WAS
MOVING THROUGH ROCKBRIDGE COUNTY VA...AND THERE WAS ANOTHER ONE
APPROACHING WESTERN GREENBRIER COUNTY AND SUMMERS COUNTY IN
SOUTHEAST WEST VIRGINIA. AS WE PROGRESS INTO THE LATE EVENING AND
TOWARDS MIDNIGHT....FORECAST CHANGES WERE A LITTLE MORE EXPANSIVE.
BASED UPON THE LATEST HRRR AND RNK WRF. THE FORECAST WILL NOW
REFLECT LITTLE OR NO COVERAGE OF PRECIPITATION OUTSIDE SOUTHEAST
WEST VIRGINIA AND NEIGHBORING PORTIONS OF SOUTHWEST VIRGINIA ONCE
WE REACH THAT TIME TONIGHT.
AS OF 330 PM EDT MONDAY...
PWATS 2-3 STANDARD DEVIATIONS ABOVE NORMAL WILL HELP FUEL
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS THIS EVENING.
THE AIRMASS IS UNSEASONABLY JUICY BUT LACK OF ANY GOOD DYNAMICS
SHOULD KEEP ACTIVITY UNORGANIZED. NEVER THE LESS...SLOW MOVEMENT
WILL YIELD HEAVY DOWNPOURS FOR ANY PASSING SHOWER/STORM.
FORECAST AREA REMAINS UNDERNEATH A VERY SHARP UPPER LEVEL
RIDGE...WHICH IS PROMOTING VERY LIGHT STEERING WINDS...0-8KM MEAN
WIND OF ONLY 11 KTS...FROM 290 DEGREES. THIS UPPER RIDGE IS
EXPECTED TO WEAKEN AS WE TRANSITION THROUGH THE NEXT 12-18
HOURS...AS LOW PRESSURE MOVES ACROSS THE GREAT LAKES AND INTO
ONTARIO CANADA. AT THE SURFACE...A COLD FRONT WILL TRAIL SOUTH
FROM THE LOW...CROSSING THE OHIO VALLEY TONIGHT. AS THE FRONT
APPROACHES...IT WILL FOCUS THE DEEPER MOISTURE FROM THE OH/TN
VALLEYS INTO THE WEST SIDE OF THE APPALACHIANS. THIS SQUEEZE PLAY
OF DEEPER MOISTURE IN ADDITION TO LINGERING INSTABILITY OVER THE
MOUNTAINS WILL RESULT IN GOOD COVERAGE OF SHOWER ACTIVITY THROUGH
THIS EVENING.
COVERAGE AND INTENSITY OF SHOWER AND THUNDERSTORM ACTIVITY WILL
DECREASE WITH THE LOSS OF DAYTIME HEATING. HOWEVER...WITH THE
COLD FRONT CONTINUING ITS APPROACH OVERNIGHT...SHOWER THREAT WILL
NOT SUBSIDE ALTOGETHER. MOISTURE TRANSPORT AND CONVERGENCE PER
SOUTHWEST WIND FLOW AHEAD OF THE FRONT WILL CONTINUE TO GENERATE
ACTIVITY INTO THE LATE NIGHT.
SURFACE FRONT IS EXPECTED TO REACH THE WESTERN SLOPES OF THE
APPALACHIANS BY DAYBREAK TUESDAY...THEN MOVE OVER AND EAST OF THE
MTNS MID-DAY...CLEARING THE CWA BY TUESDAY EVENING. WILL MAINTAIN
THREAT FOR SHOWERS UNTIL THE PASSAGE OF THE FRONT...FOLLOWED BY
CLEARING AND DRYING WITH FROPA.
MET/MAV TEMPERATURE GUIDANCE LOOKS GOOD...AND USED A BLEND FOR
TONIGHT`S LOWS AND TUESDAYS HIGHS...READINGS REMAINING QUITE MILD
TONIGHT...AOA 60 FOR LOWS...FOLLOWED BY ANOTHER WARM DAY TUESDAY
WITH HIGHS RANGING IN THE 70S MTNS TO THE 80S IN THE LOWER
ELEVATIONS.
ANY SIGNIFICANT COOLING/DRYING WILL NOT TAKE PLACE UNTIL WE CHANGE
AIRMASSES LATER TUESDAY...BECOMING NOTICEABLE ONCE THE SUN GOES
DOWN TUESDAY EVENING.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
AS OF 300 PM EDT MONDAY...
ANY LINGERING CONVECTION IN THE FAR SOUTHEAST PORTIONS OF FORECAST
AREA WILL TAPER OFF BY 06Z WEDNESDAY. LOW TEMPERATURES TUESDAY NIGHT
WILL RANGE FROM THE UPPER 40S IN THE NORTHWEST MOUNTAINS TO
THE LOWER 60S IN THE PIEDMONT.
HIGH PRESSURE IN THE MIDWEST WILL RIDGE SOUTHEAST INTO OUR AREA FOR
WEDNESDAY PROVIDING A BREAK FROM THE ACTIVE CONVECTION. THE COOLER
HIGH TEMPERATURES ON WEDNESDAY WILL ALSO BE A WELCOME CHANGE WITH
READINGS FROM THE LOWER 60S IN THE NORTHWEST MOUNTAINS TO THE MID
80S IN THE PIEDMONT. WITH A WEAK SHORTWAVE ROTATING EAST ACROSS THE
REGION WEDNESDAY NIGHT...ALLOW FOR SOME LIGHT POPS IN THE WEST.
LOW TEMPERATURES WEDNESDAY NIGHT WILL VARY FROM THE UPPER 40S IN
THE WEST TO THE UPPER 50S IN THE EAST.
THURSDAYS FORECAST REMAINS A CHALLENGE WITH THE LATEST MODEL RUNS
ALL DEPICT A STRONGER SHORTWAVE TRACKING ACROSS THE AREA...BUT WITH
WIDELY VARYING DEGREES OF INTENSITY AND RESULTANT
MOISTURE/PRECIPITATION. WITH CAUTION...ELECTED TO USE A BLEND OF
SUPERBLEND AND HPCGUIDE WITH SCATTERED POPS FOR THURSDAY. HIGH
TEMPERATURES THURSDAY WILL WARM TO AROUND 60 DEGREES IN THE
NORTHWEST TO AROUND 80 DEGREES ALONG THE SOUTHERN BLUE RIDGE.
SHORTWAVE WILL EXIT TO THE SOUTHEAST THURSDAY NIGHT AS SFC HIGH
PRESSURE SLIDES FROM THE PLAINS TO THE GREAT LAKES. OVERALL...THE
AIRMASS APPEARS TO BE TOO STABLE AND DRY IN THE LOWER LEVELS TO
SUPPORT MUCH THUNDER WITH THIS EVENT. HOWEVER...A NOSE OF
INSTABILITY SUPPORT ISOLATED THUNDERSTORM ACROSS SOUTHERN PORTIONS
OF FORECAST AREA. DIURNAL CONVECTION TAPERS OFF QUICKLY THURSDAY
NIGHT. LOW TEMPERATURES THURSDAY NIGHT WILL GENERALLY VARY FROM THE
UPPER 40S IN THE MOUNTAINS TO THE UPPER 50S IN THE PIEDMONT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 300 PM EDT MONDAY...
MOISTURE...WARMTH...AND HUMIDITY ARE POISED TO RETURN BY EARLY NEXT
WEEK AS YET ANOTHER DEEP UPPER LOW BUILDS INTO THE SOUTHWEST UNITED
STATE...THE NORTHEAST TROUGH PUSHES EASTWARD INTO THE NORTHERN
ATLANTIC...AND AN ELONGATED RIDGE BETWEEN THESE TWO FEATURES DRIFTS
INTO OUR REGION. HIGH TEMPERATURES FRIDAY WARM INTO THE MID 60S IN
THE MOUNTAINS TO THE MID 70S IN THE PIEDMONT. LOW TEMPERATURES WILL
DROP INTO THE MID 40S TO THE 50S IN GENERAL.
ON SATURDAY...CANADIAN HIGH PRESSURE SHIFTS OFF THE MID-ATLANTIC
COAST...AS FRONTAL BOUNDARY IS CENTRAL U.S. LIFTS NORTHEAST. KEPT
SATURDAY DRY...WITH HIGH TEMPERATURES RANGING FROM THE MID 60S IN
THE NORTHWEST MOUNTAINS TO THE UPPER 70S IN THE PIEDMONT.
AS THE HIGH CENTER MOVES EAST...AN EAST TO SOUTHEAST RETURN FLOW ON
THE BACKSIDE MAY DEVELOP A WEDGE ACROSS THE REGION OVER THE WEEKEND.
WITH THE POTENTIAL OF OVERRUNNING PRECIPITATION DEVELOPING FROM THE
WEST. ADDED A SLIGHT CHANCE OF SHOWERS IN THE NORTHWEST MOUNTAINS OF
NORTH CAROLINA. MODERATED LOW TEMPERATURES SATURDAY NIGHT WITH
VALUES MAINLY IN THE 50S...WITH INCREASED CLOUD COVER. SCATTERED
SHOWERS CONTINUED ON SUNDAY WITH THE BEST CHANCES IN THE NORTHWEST.
THE UPPER RIDGE WILL SHIFT SOUTHEAST BY MONDAY...ALLOWING AN ACTIVE
BAROCLINIC ZONE TO SHIFT SOUTH AND EAST INTO THE REGION FROM THE
OH/TN VALLEY. CONTINUED THE POTENTIAL FOR SCATTERED CONVECTION ON
TUESDAY.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 200 AM EDT TUESDAY...
OCCASIONAL SHOWER ACTIVITY WILL MOVE ACROSS THE AREA OVERNIGHT AS
WEAK DISTURBANCES PASS OVERHEAD...INTERACTING WITH THE VERY MOIST
AIR IN THE LOW LEVELS OF THE ATMOSPHERE. THROUGH THE REMAINDER
OF THE NIGHT...MID LEVEL CLOUDS WITH BASES AT 8KFT AND UP WILL
REMAIN IN PLACE. WILL ALSO SEE LOCALIZED IFR CONDITIONS AS POCKETS
OF FOG AND ASSOCIATED UPSLOPE LOW CEILINGS DEVELOP...ESPECIALLY
ACROSS AREAS THAT RECEIVED SIGNIFICANT RAINFALL ON MONDAY.
HOWEVER...ANY SHOWERS MOVING ACROSS THE AREA OVERNIGHT MAY STIR
THE ATMOSPHERE JUST ENOUGH TO CAUSE FOG AND LOW CLOUDS TO MIX OUT
FOR A TIME.
FOG AND LOW CEILINGS WILL LIFT AFTER 19/13Z AS HEATING CAUSING
WESTERLY WIND FLOW ALOFT TO MIX DOWN TO THE SURFACE. EXPECT BANDS
OF SHOWER ACTIVITY TO PASS ACROSS THE AREA DURING THE MORNING AND
AFTERNOON...WHICH MAY RESULT IN BRIEF PERIODS OF MVFR/IFR
VISIBILITIES. A COLD FRONT WILL ENTER SOUTHEAST WEST VIRGINIA
DURING THE AFTERNOON...RESULTING IN A SOLID NORTHWEST WIND SHIFT
WITH SPEEDS 6 TO 10 KTS. OCCASIONAL GUSTS UP TO 25 KNOTS ARE
POSSIBLE IN THE MOUNTAINS. FROPA WILL ALSO RESULT IN CLEARING
SKIES AS HIGH PRESSURE BUILDS IN. THE FRONT WILL CONTINUE TO CROSS
THE AREA...EXITING TO THE EAST AROUND 20/00Z.
EXTENDED AVIATION DISCUSSION...
DRIER/COOLER CONDITIONS ARE EXPECTED TUESDAY NIGHT AND WEDNESDAY.
AN UPPER DISTURBANCE WILL LIKELY BRING SOME MVFR CEILINGS AND
SHOWERS BACK INTO THE AREA THURSDAY...MOVING OUT FRIDAY MORNING...
WITH VFR CONDITIONS RETURNING FRIDAY AFTERNOON AND SATURDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS/PM
NEAR TERM...DS/PM
SHORT TERM...KK
LONG TERM...KK
AVIATION...AMS/NF
AREA FORECAST DISCUSSION
NWS PORTLAND
240 PM PDT TUE MAY 19 2015
.SYNOPSIS...BROAD LOW PRESSURE CONTINUES TO DOMINATE THE WESTERN
UNITED STATES WITH GENERAL UNSETTLED WEATHER ACROSS THE REGION
THROUGH THE WEEKEND. ONSHORE FLOW SHOULD WEAKEN AGAIN
WEDNESDAY...ALLOWING A RETURN TO WARMER TEMPERATURES AND A SLIGHT
CHANCE OF THUNDER TO SPREAD BACK WEST INTO THE WILLAMETTE VALLEY.
INCREASING ONSHORE FLOW SHOULD KEEP TEMPERATURES NEAR NORMAL
THURSDAY THROUGH THE WEEKEND...AND KEEP THE BEST SHOWER/THUNDERSTORM
CHANCES CONFINED TO THE CASCADES.
&&
.SHORT TERM...TONIGHT THROUGH FRIDAY...CONVECTION BEGAN FIRING UP IN
EARNEST AROUND 1 PM THIS AFTERNOON NEARER THE CASCADE CREST WHERE
THE STRATUS HAD BURNED OFF OR WAS RELATIVELY THIN TO BEGIN WITH.
THERE ARE SOME THIN SPOTS IN THE STRATUS ELSEWHERE OFF THE CASCADES
BUT FIND IT HARD TO BELIEVE THE TEMPERATURES WILL WARM ENOUGH TO
REACH CONVECTIVE TEMPERATURES AROUND THE MID 70S TODAY. BOTTOM LINE
WILL BE A FAR LESS EXCITING EVENING THAN LAST NIGHT THOUGH STILL
HAVE POTENTIAL FOR BRIEF HEAVY RAINS UNDER SOME OF THE CELLS.
SHOWERS WILL GREATLY DIMINISH AGAIN THIS EVENING AS THE SUN SETS.
THERE IS A WEAK LOWER TO MID LEVEL SHORTWAVE ROTATING AROUND THE
NORTHWESTERN PERIPHERY OF THE LOOSELY DEFINED CLOSED UPPER LOW
TRANSITING THE GREAT BASIN TONIGHT. THIS SHORTWAVE MAY HOLD TOGETHER
LONG ENOUGH TO BRING LIGHT CONVECTIVE DEBRIS SHOWERS OVERNIGHT
MAINLY TO THE EASTERN HALF OF LANE COUNTY.
WEDNESDAY CAN LARGELY BE CONSIDERED A TRANSITION DAY AS THE PREVIOUS
UPPER LOW OVER THE DESERT SW WILL HAVE LIFTED AND CONTINUES TO MOVE
NORTHEAST ACROSS THE ROCKIES WHILE ANOTHER UPPER LOW DROPS SOUTH
FROM THE GULF OF ALASKA AND WELL OFFSHORE. AS SUCH THE PACNW WILL
REMAIN IN A MOIST GREY AREA WITH A FAIRLY NON DESCRIPT UPPER LEVEL
FLOW PATTERN. EXPECT ANOTHER MORNING WITH A FAIRLY DEEP STRATUS
LAYER BUT THIS TIME WITH INDICATIONS OF THE LAYER CLEARING BEGINNING
MID-DAY TO EARLY AFTERNOON. UPPER LEVEL CONDITIONS REMAIN MOIST AND
UNSTABLE AND WILL LIKELY PROMOTE ANOTHER DAY OF THUNDERSTORMS.
EXPECT STORMS TO INITIATE OVER THE CASCADES AROUND MID-DAY. THE
LOWER ELEVATIONS WILL NEED THE STRATUS LAYER TO BURN OFF BEFORE
DEEPER CONVECTION CAN DEVELOP. SEEMS LIKE THE NORTH END OF THE
VALLEY MAY CLEAR OUT AS EARLY AS 2 OR 3 PM WHILE THE SOUTH END MAY
NOT BREAK FREE UNTIL CLOSER TO 4 OR 5. WOULD THEN EXPECT THE DEEPER
SHOWERS AND POSSIBLE THUNDERSTORMS TO DEVELOP AN HOUR OR TWO AFTER
THAT. GIVEN A LATE STRATUS BREAKOUT AS EXPECTED...THE SURFACE
INVERSION COULD BREAK RATHER QUICKLY WITH STORMS GOING FROM THE
PROVERBIAL 0 TO 60 FAIRLY QUICKLY. STILL COULD SEE LOCALIZED VERY
HEAVY RAINS BUT WILL NEED TO SORT OUT SOME OF THE DETAILS REGARDING
TIMING AND COVERAGE BEFORE GETTING TOO CONFIDENT ON THE QUALITY
DETAILS.
THURSDAY AND FRIDAY APPEAR TO BRING A ANOTHER COUPLE DAYS OF
INCREASING MARINE LAYER WITH TEMPERATURES BACK DOWN TO THE LOWER
70S. HAVE LOWER CONFIDENCE WITH REGARD TO HOW LONG THE LAYER WILL
LAST ON THURSDAY. FEEL REASONABLY CONFIDENT THERE WILL BE CONVECTION
FOR THE CASCADES AGAIN BUT AM NOT TERRIBLY SURE ABOUT THE LOWER
ELEVATIONS. THAT WILL ALL DEPEND ON THE EXTENT AND DURATION OF THE
STRATUS LAYER. FRIDAY IS A LITTLE MORE CERTAIN AND HAVE REASONABLE
CONFIDENCE THE THUNDERSTORMS WILL STAY EAST OF THE CREST BUT STILL
MIGHT GET ENOUGH INSTABILITY FOR SOME SHOWERS ALONG THE WEST SLOPES.
TEMPERATURES WILL EASILY BE WARMEST TOMORROW AD GIVE THE BEST SHOT
OF VALLEY STORMS WHILE THURSDAY AND FRIDAY WILL DROP BACK CLOSER TO
THE 70 DEGREE MARK. /JBONK
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY...MODEL GUIDANCE CONTINUES
TO REMAIN IN GENERAL AGREEMENT FOR THE END OF THE WEEK WITH THE
BLOCKING PATTERN CONTINUING WITH HIGH PRESSURE OVER ALASKA AND
WESTERN CANADA ABOVE UPPER LOW PRESSURE SLOWLY SLIDING EAST ACROSS
THE SOUTHWESTERN U.S. AND GREAT BASIN. KEPT SOME SLIGHT CHANCE
SHOWERS IN THE CASCADES FOR THE WEEKEND WITH PERHAPS SHOWERS
ATTEMPTING TO MAKE THEIR WAY INTO THE FOOTHILLS OR EASTERN
VALLEY...THOUGH CONFIDENCE IS LOW. HEIGHTS MAY RISE A BIT FOR THE
START OF THE WEEK THOUGH MODELS DIVERGE CONSIDERABLY IN THE DETAILS
SO CONFIDENCE REMAINS LOWER IN THE SPECIFICS FOR THIS TIME. CULLEN
.AVIATION....MVFR STRATUS THIS AFTERNOON WILL LIKELY LIFT ENOUGH TO
PRODUCE VFR CONDITIONS ACROSS THE INTERIOR THIS EVENING. THERE IS A
CHANCE CONDITIONS COULD FLUCTUATE BETWEEN MVFR AND VFR THIS EVENING
IN POCKETS AROUND THE WILLAMETTE VALLEY DUE TO THE SLOW IMPROVEMENT
THUS FAR TODAY. EITHER WAY...EXPECT CONDITIONS TO DETERIORATE ONCE
AGAIN TO MVFR LATER TONIGHT FOR MOST INTERIOR TAF SITES...LIKELY
BETWEEN 09Z AND 18Z WEDNESDAY. KEUG...KHIO...KSLE WILL LIKELY BE THE
LOCATIONS TO HOLD ONTO VFR CONDITIONS THE LONGEST. COASTAL LOCATIONS
SHOULD STAY SOLIDLY HIGH END IFR TO MVFR THROUGH APPROXIMATELY 18Z
WEDNESDAY BEFORE CONDITIONS LIKELY IMPROVE TO VFR AFTER 18Z
WEDNESDAY.
KPDX AND APPROACHES...MVFR CONDITIONS SHOULD GIVE WAY TO VFR TOWARDS
23Z TUESDAY. IT IS POSSIBLE CONDITIONS COULD FLUCTUATE IN AND OUT OF
HIGH END MVFR CONDITIONS THIS EVENING...BUT EXPECT A DETERIORATION
MORE SOLIDLY INTO MVFR LATER TONIGHT BETWEEN 09Z AND 18Z WEDNESDAY.
PATCHY DRIZZLE IN THE MORNING AGAIN COULD BRING ADDITIONAL IFR
CONDITIONS AFTER 12Z WEDNESDAY...BUT CONFIDENCE IN THIS SCENARIO
DEVELOPING IS LOW. /NEUMAN
&&
.MARINE...SURFACE HIGH PRESSURE AND THERMAL LOW PRESSURE OVER THE
INLAND NORTHWEST SHOULD GENERALLY KEEP WINDS BELOW 20 KT THROUGH THE
UPCOMING WEEKEND. SEAS WILL ALSO HOVER IN THE 3 TO 6 FT RANGE
THROUGH THIS PERIOD. A FRESH NORTHWEST SWELL WILL LIKELY MAKE SEAS A
BIT CHOPPIER THAN NORMAL DESPITE WINDS REMAINING RELATIVELY LIGHT.
STRONG TO VERY STRONG EBBS WILL LIKELY PRODUCE STEEP EBB CHOP THE
NEXT SEVERAL MORNINGS ON THE COLUMBIA RIVER BAR...BUT SEAS SHOULD
REMAIN SMALL ENOUGH THAT SMALL CRAFT ADVISORIES FOR ROUGH BAR DO NOT
APPEAR NECESSARY. /NEUMAN
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
Area Forecast Discussion
National Weather Service Spokane WA
1146 AM PDT TUE MAY 19 2015
.SYNOPSIS...
A mild, occasionally unsettled pattern will persist over the
region through the week. While most of the area will remain dry,
scattered showers and a few afternoon and evening thunderstorms
will be possible mainly over the southeast and Cascades. A shift
to a cooler and more unsettled pattern is expected for the
upcoming holiday weekend.
&&
.DISCUSSION...
Rest of today...Deep upper level low continues to hover over
northern Utah with moisture and instability streaming westward
over southern Idaho and much of Oregon. Meanwhile most of the
Inland Northwest continues to see relatively drier air filter in
from the northeast due to a strong high pressure east of the
Continental Divide. This drier air mass will ensure that most of
the forecast area sees a dry and mild day. The only locations
which could see some precipitation develop later today would be
across extreme SE Washington and adjacent portions of the Idaho
Panhandle. Models have been insistent that the best potential
instability will develop in this area later today. Whether or not
this instability can produce deep enough convection for showers or
thunderstorms remains uncertain. Yesterday the coverage was quite
limited and all the lightning strikes occurred south and west of
our forecast area. That might be the same story today. Various
runs of the HRRR vary on whether or not to produce convection in
this area. The latest GOES Bufr soundings in that area suggest
a little more heating could tap into the potential instability
and produce some rapidly developing cumulus towers and eventually
some showers. The other area with some convective potential is
near the Cascades. Satellite is already detecting some of this
convection but it looks like the tops are too shallow to produce
preciptiation for now. If it does deepen enough, we would see a
small chance of showers in that area, however the models have been
showing this signature for the last several days and it has yet to
materialize at least during the afternoon hours. fx
&&
.AVIATION...
18Z TAFS: Dry northeast flow will deliver VFR conditions to all
forecast sites. There will be a small chance of -shra that could
develop over extreme SE WA/NC ID and an westward drift could move
them close enough to LWS to warrant the mention of vcsh in their
forecast. The HRRR keeps this threat through 04-06z or so. After
that we should see any chance of convection move out of that area
with VFR conditions prevailing. fx
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 75 50 77 51 78 52 / 0 10 0 10 10 10
Coeur d`Alene 74 49 77 49 77 50 / 0 10 0 10 20 20
Pullman 75 47 77 48 75 47 / 10 10 10 10 30 50
Lewiston 81 53 82 54 80 54 / 10 20 10 20 30 30
Colville 79 49 80 49 82 50 / 0 0 0 10 10 10
Sandpoint 74 45 75 45 76 46 / 0 0 0 10 10 10
Kellogg 75 46 76 46 76 47 / 10 10 10 10 20 30
Moses Lake 82 55 83 55 84 54 / 10 0 0 10 10 10
Wenatchee 83 56 84 58 83 58 / 0 10 10 10 20 20
Omak 82 49 83 50 83 52 / 0 0 0 10 20 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1159 PM EDT MON MAY 18 2015
.SYNOPSIS...
COLD FRONT CROSSES FIRST THING TUESDAY MORNING. HIGH PRESSURE
BUILDS TOWARD THE AREA ON WEDNESDAY. IT MAT BE TEMPORARILY THWARTED
BY A WAVE ON THURSDAY...BEFORE BUILDING IN IN ERNEST ON FRIDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
SENT A QUICK UPDATE TO ADJUST POPS PER LATEST RADAR IMAGES. A
BROKEN LINE OF SHOWERS...WITH FEW LIGHTNING STRIKES TO OUR FAR
SOUTH OVER THE WESTERN SLOPES OF WV AND EXTREME SOUTHWEST VA...MOVING
EAST AROUND 15 KNOTS. BEHIND THIS LINE RADAR LOOKS DRY EVEN ALONG
THE UPCOMING COLD FRONT. THEREFORE...KEPT HIGH CHANCE WITH THE
SHOWERS AND REMOVE CHANCES BEHIND IT. REST OF FORECAST REMAINS ON
TRACK.
PREVIOUS DISCUSSION BELOW...
815 PM UPDATE...
FINE TUNED POPS TO KEY IN MAINLY ON BROKEN LINE OF SHOWERS
CROSSING THE OHIO RIVER AS OF 00Z. THE LINE CLOSER TO THE FRONT
WILL MOSTLY FALL APART BEFORE REACHING THE FCST AREA OVERNIGHT
TONIGHT. THE THREAT FOR THUNDER OVERALL QUICKLY WANES TONIGHT. THE
COLD FRONT CROSSES/MIXES THROUGH TUE MORNING.
PREV DISCN...
SCATTERED POPCORN CONVECTION IS BEING SEEN ACROSS THE AREA THIS
AFTERNOON...AS MOIST AIR MASS HEATS UP IN BOUNDARY LAYER HEATING.
OTHERWISE...SLIGHTLY MORE ORGANIZED CONVECTION NOTED OVER EASTERN
KY AND SOUTHERN OH...AS WEAK VORT FEATURE APPROACHES FROM THE
WEST. IT APPEARS THE LATEST RAP RUNS HAVE A FAIR HANDLE ON THE
OVERALL MASS FIELDS AND THE PROGRESSION OF FEATURES ACROSS
TONIGHT. USED A RATHER BROAD BRUSH APPROACH TO COVER POPS THIS
AFTERNOON AND THIS EVENING. HAVE FRONT CROSSING LATE TONIGHT AND
EARLY MORNING. SPEED UP TIMING SLIGHTLY...BY AN HOUR OR TWO...NOT
MUCH TO REALLY MAKE A CHANGE TO THE OVERALL FORECAST.
FOR TEMPS...WILL SEE A FEW DEGREES OF COOLING TUESDAY OVER TODAYS
HIGHS AS COOLER AIR MASS MOVES IN...WITH DRYING OF THE ATMOSPHERIC
COLUMN.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
ZONAL FLOW FOR THE SHORT TERM PART OF THE FORECAST SHOULD PROVIDE
FOR A DRY FORECAST. DO HAVE SLIGHT CHANCE POPS WEDNESDAY NIGHT AS
SEVERAL UPPER LEVEL DISTURBANCES MOVE ACROSS THE NORTHERN OHIO VALLEY
AROUND THE 520+ LOW OVER NEWFOUNDLAND.
WENT MAINLY WITH ALL BLEND GUIDANCE FOR TEMPERATURES THROUGH THE
PERIOD...KEEPING THEM BELOW CLIMATOLOGY.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
A HIGH BEGINS TO BUILD IN THE GULF OF MEXICO ON SUNDAY...MIGRATES
EAST AND TRIES TO STRENGTHEN. THIS WILL LEAD TO A POTENTIALLY
MESSY FORECAST FOR THE OHIO VALLEY WITH SEVERAL UPPER LEVEL
DISTURBANCES ROTATING AROUND THE CANADIAN LOW PRESSURE SYSTEMS.
HAVE CHANCE POPS ON SUNDAY AND MONDAY AS EXPECT MOISTURE TO BECOME
TRAPPED UNDER THE HIGH. THERE REALLY ISN/T ANYTHING SIGNIFICANT TO
FOCUS ON TO TIME THESE EVENTS.
WENT WITH A BLEND OF GUIDANCE FOR TEMPERATURES. TEMPERATURES WILL
RISE THROUGH THE EXTENDED PART OF THE FORECAST.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
COLD FRONT CROSSES TUE...EARLY ENOUGH TO PRECLUDE A THUNDERSTORM
THREAT. ONE LAST LINE OF BROKEN SHOWERS...WELL IN ADVANCE OF THE
COLD FRONT...WAS CROSSING THE OHIO RIVER NEAR 00Z...AND WILL CROSS
WV THROUGH MIDNIGHT WITH NOTHING WORSE THAN MVFR CONDITIONS LIKELY.
THERE WAS ANOTHER BROKEN LINE OF SHOWERS AND THUNDERSTORMS NEAR THE
INDIANA / OHIO LINE...CLOSER TO THE COLD FRONT...BUT THIS LINE WILL
LIKELY FALL APART BEFORE REACHING THE MIDDLE OHIO VALLEY OVERNIGHT.
VALLEY FOG WILL AGAIN FORM OVERNIGHT E OF THE OHIO RIVER. MVFR
STRATUS WILL ALSO FORM OVERNIGHT. THE MORNING STRATUS WILL THEN MIX
HIGHER BEFORE MIXING OUT ALTOGETHER ON TUE.
LIGHT S TO SW FLOW OVERNIGHT WILL BECOME LIGHT W TO NW ON TUE. IT
MAY STRENGTHEN AND BECOME JUST A BIT GUSTY TUE AFTERNOON. LIGHT W
FLOW ALOFT OVERNIGHT WILL BECOME LIGHT TO MODERATE W TO NW ON TUE.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: FOG AND STRATUS FORMATION OVERNIGHT AND BREAK
UP TUE MORNING MAY VARY. THERE MAY BE MORE IFR THAN FCST ON
EITHER...ESPECIALLY E OF THE OHIO RIVER.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE TUE 05/19/15
UTC 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
EDT 1HRLY 22 23 00 01 02 03 04 05 06 07 08 09
CRW CONSISTENCY H M M M M M M H H H H M
HTS CONSISTENCY H H H M M M M M M M H H
BKW CONSISTENCY H H H H H H L L L L L L
EKN CONSISTENCY H M H L M M M L M L L L
PKB CONSISTENCY M H H H H H M M M M M M
CKB CONSISTENCY H H M H M M M L L L L M
AFTER 06Z WEDNESDAY...
FOG/LOW CLOUDS POSSIBLE OVERNIGHT TUE NT INTO WED MORNING AND
POSSIBLY AGAIN OVERNIGHT THU NT INTO FRI MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...FB/KMC/TRM
NEAR TERM...ARJ/TRM
SHORT TERM...FB
LONG TERM...FB
AVIATION...TRM
AREA FORECAST DISCUSSION...UPDATED
NWS CHEYENNE WY
913 PM MDT WED MAY 20 2015
.UPDATE...
ISSUED AT 913 PM MDT WED MAY 20 2015
NO MAJOR CHANGES FOR THE EVENING UPDATE. MOST OF THE LIGHT SHOWER
ACTIVITY FROM LATE AFTERNOON EARLY EVENING HAS DISSIPATED WITH THE
EXCEPTION OF SOME LIGHT TO MODERATE SHOWERS PERSISTING IN
SOUTHWESTERN CARBON COUNTY WY. AREAS OF DENSE FOG HAVE REDEVELOPED
OVER THE SUMMIT BETWEEN CHEYENNE AND LARAMIE...AND WILL CONTINUE
THE DENSE FOG ADVISORY THROUGH THURSDAY MORNING FOR THAT PART OF
THE SOUTH LARAMIE RANGE.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 243 PM MDT WED MAY 20 2015
SFC ANALYSIS SHOWS THE HIGH PRESSURE CENTER LOCATED NEAR THE PINE
RIDGE WITH EAST TO NORTHEAST UPSLOPE AND PERSISTENT LOW CLOUDS
ACROSS THE REGION. IT HAS BEEN ANOTHER COOL DAY WITH TEMPS A GOOD
20 DEGREES BELOW NORMAL. EXPIRED THE DENSE FOG ADVISORY FOR THE
SOUTH LARAMIE RANGE WITH WYDOT OBS SHOWING MOST VIS ABOVE 1 MILE.
THE HRRR DOES INDICATE VIS DROPPING BELOW ONE HALF MILE OVER THE
SOUTH LARAMIE RANGE BY 03Z. THIS MAKES SENSE WITH SFC WINDS
REMAINING SOUTHEAST TO SOUTH OVERNIGHT. HAVE AREAS OF FOG FROM
BUFORD TO THE SUMMIT BY EARLY TONIGHT AND CONTINUING THROUGH
THURSDAY MORING. WILL LET THE EVENING/NIGHT SHIFT MONITOR THE OBS
AND WEBCAMS OVER THE SUMMIT...AS DENSE FOG IS DEFINITELY POSSIBLE IN
THIS PATTERN. SHOWERS DEVELOPING THIS AFTN ALONG AND WEST OF THE
LARAMIE RANGE HAVE BEEN STRUGGLING TO STAY TOGETHER IN THE VERY
STABLE AIRMASS OVER THE PLAINS. KEPT ISOLATED TO SCATTERED SHOWERS
CONFINED TO MAINLY THE LARAMIE RANGE AND POINTS WEST THROUGH THE
EVENING.
PATTERN DOES NOT CHANGE A WHOLE LOT BY THURSDAY. LOW CLOUDS WILL BE
STUBBORN TO CLEAR YET AGAIN WITH MOIST SOUTHEAST LLVL FLOW.
SLIGHTLY BETTER INSTABILITY WILL EXIST ALONG THE LARAMIE RANGE (CAPE
VALUES OF 100-200 J/KG) BUT THIS IS LARGELY DEPENDENT ON SOME AFTN
CLEARING...WHICH IS QUESTIONABLE. INSTABILITY REALLY DROPS OFF TO
THE EAST OF CHEYENNE SO EXPECTING STORMS TO REMAIN CONFINED IN
VICINITY OF THE LARAMIE RANGE. A SHORTWAVE WILL EJECT NORTHWARD
FROM COLORADO BY LATE THURS NIGHT AND FRI MORNING. WITH GOOD UPPER
LEVEL DIFLUENCE...MODELS HAVE BEEN CONSISTENT AT SHOWING WIDESPREAD
RAIN DEVELOPING OVER THE PLAINS BY FRI MORNING AND CONTINUING
THROUGH MUCH OF THE DAY. THIS IS LOOKING LIKE ANOTHER 0.25-0.75
INCH MAINLY STRATIFORM RAIN EVENT FOR LOCATIONS TO THE EAST OF THE
LARAMIE RANGE. DID LOWER HIGHS A FEW DEGREES ON FRI WITH HIGHS
STRUGGLING TO GET ABOVE THE MID 50S.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 243 PM MDT WED MAY 20 2015
THE MAIN CONCERN WITH THIS PORTION OF THE FORECAST IS THE SEVERE
WEATHER POTENTIAL SATURDAY.
SATURDAY-SATURDAY NIGHT:
LATEST LOOK AT THE GEM/GEFS ENSEMBLES AND ECMWF ARE SHOWING
REALLY GOOD AGREEMENT IN THE TRACK OF THE UPPER LEVEL TROF THIS
WEEKEND. THE MODELS ARE ALSO IN AGREEMENT IN SHOWING THIS CLOSED
UPPER TROF OPENING UP IN NORTHWEST COLORADO AND SENDING ITS FIRST
PIECE OF ENERGY INTO OUR REGION SATURDAY. HOWEVER...THERE IS QUITE
A BIT OF STANDARD DEVIATION IN THE PLACEMENT OF THE SURFACE LOW
AROUND 00Z SUNDAY. THE MEAN ENSEMBLES ARE SHOWING THE SURFACE LOW
DEVELOPING IN EASTERN COLORADO. HOWEVER...THERE IS SOME HINTS THAT
THIS SURFACE LOW MAY ACTUALLY DEVELOP FURTHER NORTH IN NORTHEAST
COLORADO AND LIFT NORTHEAST THROUGH THE NEBRASKA PANHANDLE. IF
THIS SURFACE LOW DEVELOPS FURTHER NORTH...WE MAY SEE WARMER
TEMPERATURES AND HIGHER LOW LEVEL MOISTURE BEING DRAWN INTO AREAS
EAST OF THE LARAMIE WHICH WILL RESULT IN HIGHER INSTABILITY. THIS
COULD SET THE STAGE FOR SEVERE WEATHER IN AREAS EAST OF THE
LARAMIE RANGE SATURDAY AFTN/EVE...ESPECIALLY WITH 0-6KM SHEAR
VALUES APPROACHING 40 TO 50 KTS. ANOTHER CONCERN IS WHETHER OR NOT
WE WILL SEE LOW CLOUDS. AT THIS POINT...IT DOES NOT APPEAR THAT
THE LOW CLOUDS WILL BE PRESENT...BUT WE WILL HAVE TO SEE HOW THAT
EVOLVES. IF THE LOW CLOUDS ARE NOT PRESENT...TEMPERATURES SHOULD
BE ABLE TO CLIMB TO THE 60S.
SUNDAY-SUNDAY NIGHT:
THE MODELS ARE SHOWING THE MAIN UPPER LEVEL TROF MOVING INTO THE
AREA ON SUNDAY IN ITS WEAKENED STATE. THERE IS A LITTLE MORE
UNCERTAINTY ON HOW THIS TROF WILL IMPACT THE AREA ON SUNDAY
AFTERNOON INTO SUNDAY EVENING. AT THIS POINT...IT APPEARS LIKE THE
MAIN CONVECTION SHOW WILL BE ON SATURDAY AFTERNOON/EVENING.
HOWEVER...IF WE DO NOT SEE MANY STORMS DURING THAT TIME...THEN
SUNDAY MAY BE A DAY TO WATCH AS WELL. IF WE DO SEE WIDESPREAD
CONVECTION ON SATURDAY THEN SUNDAY CHANCES MAY BE MUCH SMALLER.
FOR NOW...WE WILL STAY WITH THE MODEL BLENDS FOR CONSISTENCY SAKE.
MONDAY-WEDNESDAY:
MODELS/ENSEMBLES ARE IN PRETTY GOOD AGREEMENT IN SHOWING THE UPPER
LEVEL RIDGE BUILDING OVER THE AREA AHEAD OF THE NEXT UPPER LEVEL
TROF MOVING INTO THE NORTHERN ROCKIES. THIS TROF WILL INDUCE UPPER
LEVEL DIFFLUENCE OVER THE AREA ON MONDAY AND TUESDAY WHICH COULD
SPARK SOME CONVECTION OVER THE MOUNTAINS WITH SOME OF THIS
CONVECTION POSSIBLY SPILLING OVER INTO THE PLAINS. OVERALL...IT
DOES NOT LOOK LIKE A REAL WET PATTERN...BUT WE CANNOT RULE OUT THE
AFTERNOON AND EVENING CONVECTION CHANCES OVER OUR AREA EITHER.
ALTHOUGH...TEMPERATURES WILL NOT BE TOO COOL WITH HIGHS CLIMBING
TO NEAR NORMAL READING WITH HIGHS MAINLY IN THE 60S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 616 PM MDT WED MAY 20 2015
STARTING TO SEE CEILINGS LIFT TO VFR FLIGHT CATEGORY AT
CHADRON...SCOTTSBLUFF AND ALLIANCE WITH SIDNEY STILL IN MVFR A BIT
LONGER THROUGH 03Z. UPSLOPE FLOW AT CHEYENNE AND LARAMIE WILL
RESULT IN PROLONGED MVFR CEILINGS AROUND 1500 FT AGL THROUGH 03Z
THEN WE DROP THE CEILINGS TO IFR OR BELOW 1000 FT AGL AS UPSLOPE
FLOW STRENGTHENS A BIT OVERNIGHT...AND WE ALSO BRING IN SOME LIGHT
FOG FOR THOSE SITES TOWARD MORNING. A BIT MORE DRIER AIR WORKING
INTO RAWLINS AND THEY SHOULD STAY VFR THROUGH THE FORECAST PERIOD.
&&
.FIRE WEATHER...
ISSUED AT 243 PM MDT WED MAY 20 2015
NO FIRE WEATHER CONCERNS THROUGH THE WEEKEND. TEMPERATURES WILL
REMAIN BELOW NORMAL AND AFTERNOON HUMIDITY VALUES WILL BE ABOVE 50
PERCENT. THE BEST CHANCE OF WIDESPREAD WETTING RAIN WILL COME
THURSDAY NIGHT AND FRIDAY.
&&
.HYDROLOGY...
ISSUED AT 243 PM MDT WED MAY 20 2015
LARAMIE RIVER AT FORT LARAMIE AND LARAMIE WILL CONTINUE TO RUN AT
RELATIVELY HIGH LEVELS THROUGH THIS WEEK...BUT AT THIS TIME IS
EXPECTED TO REMAIN WITHIN ITS BANKS. ANOTHER ROUND OF MODERATE TO
HEAVY RAINFALL IS EXPECTED OVER THE HIGH PLAINS AND POSSIBLY THE
LARAMIE VALLEY ON FRIDAY...SO WILL NEED TO CONTINUE TO MONITOR
THE LARAMIE RIVER THROUGH LATE THIS WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...DENSE FOG ADVISORY UNTIL 10 AM MDT THURSDAY FOR WYZ116.
NE...NONE.
&&
$$
UPDATE...JG
SHORT TERM...ZF
LONG TERM...REC
AVIATION...JG
FIRE WEATHER...ZF
HYDROLOGY...ZF
AREA FORECAST DISCUSSION...UPDATED
NWS CHEYENNE WY
616 PM MDT WED MAY 20 2015
.UPDATE...FOR 00Z AVIATION FORECAST RELEASE.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 243 PM MDT WED MAY 20 2015
SFC ANALYSIS SHOWS THE HIGH PRESSURE CENTER LOCATED NEAR THE PINE
RIDGE WITH EAST TO NORTHEAST UPSLOPE AND PERSISTENT LOW CLOUDS
ACROSS THE REGION. IT HAS BEEN ANOTHER COOL DAY WITH TEMPS A GOOD
20 DEGREES BELOW NORMAL. EXPIRED THE DENSE FOG ADVISORY FOR THE
SOUTH LARAMIE RANGE WITH WYDOT OBS SHOWING MOST VIS ABOVE 1 MILE.
THE HRRR DOES INDICATE VIS DROPPING BELOW ONE HALF MILE OVER THE
SOUTH LARAMIE RANGE BY 03Z. THIS MAKES SENSE WITH SFC WINDS
REMAINING SOUTHEAST TO SOUTH OVERNIGHT. HAVE AREAS OF FOG FROM
BUFORD TO THE SUMMIT BY EARLY TONIGHT AND CONTINUING THROUGH
THURSDAY MORING. WILL LET THE EVENING/NIGHT SHIFT MONITOR THE OBS
AND WEBCAMS OVER THE SUMMIT...AS DENSE FOG IS DEFINITELY POSSIBLE IN
THIS PATTERN. SHOWERS DEVELOPING THIS AFTN ALONG AND WEST OF THE
LARAMIE RANGE HAVE BEEN STRUGGLING TO STAY TOGETHER IN THE VERY
STABLE AIRMASS OVER THE PLAINS. KEPT ISOLATED TO SCATTERED SHOWERS
CONFINED TO MAINLY THE LARAMIE RANGE AND POINTS WEST THROUGH THE
EVENING.
PATTERN DOES NOT CHANGE A WHOLE LOT BY THURSDAY. LOW CLOUDS WILL BE
STUBBORN TO CLEAR YET AGAIN WITH MOIST SOUTHEAST LLVL FLOW.
SLIGHTLY BETTER INSTABILITY WILL EXIST ALONG THE LARAMIE RANGE (CAPE
VALUES OF 100-200 J/KG) BUT THIS IS LARGELY DEPENDENT ON SOME AFTN
CLEARING...WHICH IS QUESTIONABLE. INSTABILITY REALLY DROPS OFF TO
THE EAST OF CHEYENNE SO EXPECTING STORMS TO REMAIN CONFINED IN
VICINITY OF THE LARAMIE RANGE. A SHORTWAVE WILL EJECT NORTHWARD
FROM COLORADO BY LATE THURS NIGHT AND FRI MORNING. WITH GOOD UPPER
LEVEL DIFLUENCE...MODELS HAVE BEEN CONSISTENT AT SHOWING WIDESPREAD
RAIN DEVELOPING OVER THE PLAINS BY FRI MORNING AND CONTINUING
THROUGH MUCH OF THE DAY. THIS IS LOOKING LIKE ANOTHER 0.25-0.75
INCH MAINLY STRATIFORM RAIN EVENT FOR LOCATIONS TO THE EAST OF THE
LARAMIE RANGE. DID LOWER HIGHS A FEW DEGREES ON FRI WITH HIGHS
STRUGGLING TO GET ABOVE THE MID 50S.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 243 PM MDT WED MAY 20 2015
THE MAIN CONCERN WITH THIS PORTION OF THE FORECAST IS THE SEVERE
WEATHER POTENTIAL SATURDAY.
SATURDAY-SATURDAY NIGHT:
LATEST LOOK AT THE GEM/GEFS ENSEMBLES AND ECMWF ARE SHOWING
REALLY GOOD AGREEMENT IN THE TRACK OF THE UPPER LEVEL TROF THIS
WEEKEND. THE MODELS ARE ALSO IN AGREEMENT IN SHOWING THIS CLOSED
UPPER TROF OPENING UP IN NORTHWEST COLORADO AND SENDING ITS FIRST
PIECE OF ENERGY INTO OUR REGION SATURDAY. HOWEVER...THERE IS QUITE
A BIT OF STANDARD DEVIATION IN THE PLACEMENT OF THE SURFACE LOW
AROUND 00Z SUNDAY. THE MEAN ENSEMBLES ARE SHOWING THE SURFACE LOW
DEVELOPING IN EASTERN COLORADO. HOWEVER...THERE IS SOME HINTS THAT
THIS SURFACE LOW MAY ACTUALLY DEVELOP FURTHER NORTH IN NORTHEAST
COLORADO AND LIFT NORTHEAST THROUGH THE NEBRASKA PANHANDLE. IF
THIS SURFACE LOW DEVELOPS FURTHER NORTH...WE MAY SEE WARMER
TEMPERATURES AND HIGHER LOW LEVEL MOISTURE BEING DRAWN INTO AREAS
EAST OF THE LARAMIE WHICH WILL RESULT IN HIGHER INSTABILITY. THIS
COULD SET THE STAGE FOR SEVERE WEATHER IN AREAS EAST OF THE
LARAMIE RANGE SATURDAY AFTN/EVE...ESPECIALLY WITH 0-6KM SHEAR
VALUES APPROACHING 40 TO 50 KTS. ANOTHER CONCERN IS WHETHER OR NOT
WE WILL SEE LOW CLOUDS. AT THIS POINT...IT DOES NOT APPEAR THAT
THE LOW CLOUDS WILL BE PRESENT...BUT WE WILL HAVE TO SEE HOW THAT
EVOLVES. IF THE LOW CLOUDS ARE NOT PRESENT...TEMPERATURES SHOULD
BE ABLE TO CLIMB TO THE 60S.
SUNDAY-SUNDAY NIGHT:
THE MODELS ARE SHOWING THE MAIN UPPER LEVEL TROF MOVING INTO THE
AREA ON SUNDAY IN ITS WEAKENED STATE. THERE IS A LITTLE MORE
UNCERTAINTY ON HOW THIS TROF WILL IMPACT THE AREA ON SUNDAY
AFTERNOON INTO SUNDAY EVENING. AT THIS POINT...IT APPEARS LIKE THE
MAIN CONVECTION SHOW WILL BE ON SATURDAY AFTERNOON/EVENING.
HOWEVER...IF WE DO NOT SEE MANY STORMS DURING THAT TIME...THEN
SUNDAY MAY BE A DAY TO WATCH AS WELL. IF WE DO SEE WIDESPREAD
CONVECTION ON SATURDAY THEN SUNDAY CHANCES MAY BE MUCH SMALLER.
FOR NOW...WE WILL STAY WITH THE MODEL BLENDS FOR CONSISTENCY SAKE.
MONDAY-WEDNESDAY:
MODELS/ENSEMBLES ARE IN PRETTY GOOD AGREEMENT IN SHOWING THE UPPER
LEVEL RIDGE BUILDING OVER THE AREA AHEAD OF THE NEXT UPPER LEVEL
TROF MOVING INTO THE NORTHERN ROCKIES. THIS TROF WILL INDUCE UPPER
LEVEL DIFFLUENCE OVER THE AREA ON MONDAY AND TUESDAY WHICH COULD
SPARK SOME CONVECTION OVER THE MOUNTAINS WITH SOME OF THIS
CONVECTION POSSIBLY SPILLING OVER INTO THE PLAINS. OVERALL...IT
DOES NOT LOOK LIKE A REAL WET PATTERN...BUT WE CANNOT RULE OUT THE
AFTERNOON AND EVENING CONVECTION CHANCES OVER OUR AREA EITHER.
ALTHOUGH...TEMPERATURES WILL NOT BE TOO COOL WITH HIGHS CLIMBING
TO NEAR NORMAL READING WITH HIGHS MAINLY IN THE 60S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 616 PM MDT WED MAY 20 2015
STARTING TO SEE CEILINGS LIFT TO VFR FLIGHT CATEGORY AT
CHADRON...SCOTTSBLUFF AND ALLIANCE WITH SIDNEY STILL IN MVFR A BIT
LONGER THROUGH 03Z. UPSLOPE FLOW AT CHEYENNE AND LARAMIE WILL
RESULT IN PROLONGED MVFR CEILINGS AROUND 1500 FT AGL THROUGH 03Z
THEN WE DROP THE CEILINGS TO IFR OR BELOW 1000 FT AGL AS UPSLOPE
FLOW STRENGTHENS A BIT OVERNIGHT...AND WE ALSO BRING IN SOME LIGHT
FOG FOR THOSE SITES TOWARD MORNING. A BIT MORE DRIER AIR WORKING
INTO RAWLINS AND THEY SHOULD STAY VFR THROUGH THE FORECAST PERIOD.
&&
.FIRE WEATHER...
ISSUED AT 243 PM MDT WED MAY 20 2015
NO FIRE WEATHER CONCERNS THROUGH THE WEEKEND. TEMPERATURES WILL
REMAIN BELOW NORMAL AND AFTERNOON HUMIDITY VALUES WILL BE ABOVE 50
PERCENT. THE BEST CHANCE OF WIDESPREAD WETTING RAIN WILL COME
THURSDAY NIGHT AND FRIDAY.
&&
.HYDROLOGY...
ISSUED AT 243 PM MDT WED MAY 20 2015
LARAMIE RIVER AT FORT LARAMIE AND LARAMIE WILL CONTINUE TO RUN AT
RELATIVELY HIGH LEVELS THROUGH THIS WEEK...BUT AT THIS TIME IS
EXPECTED TO REMAIN WITHIN ITS BANKS. ANOTHER ROUND OF MODERATE TO
HEAVY RAINFALL IS EXPECTED OVER THE HIGH PLAINS AND POSSIBLY THE
LARAMIE VALLEY ON FRIDAY...SO WILL NEED TO CONTINUE TO MONITOR
THE LARAMIE RIVER THROUGH LATE THIS WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...DENSE FOG ADVISORY UNTIL 10 AM MDT THURSDAY FOR WYZ116.
NE...NONE.
&&
$$
SHORT TERM...ZF
LONG TERM...REC
AVIATION...JG
FIRE WEATHER...ZF
HYDROLOGY...ZF
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
412 AM CDT THU MAY 21 2015
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
INITIALLY UPDATED POPS ACROSS PORTIONS OF WESTERN AND SOUTHERN
ARKANSAS TO REFLECT CURRENT RADAR TRENDS AS WELL AS TREND TOWARDS
THE HRRR WHICH SHOWS PRECIPITATION CONTINUING FOR MUCH OF THE FIRST
HALF OF THE DAY ACROSS SOUTHERN ARKANSAS. PRECIP SHOULD CONTINUE TO
WEAKEN AND SPREAD TO THE SOUTH AS SLOW MOVING COLD FRONT CONTINUES
TO MOVE SOUTH.
CONTINUED THE TREND OF LOWERING TEMPS AND GOING BELOW GUIDANCE FOR
THURSDAY AND FRIDAY WITH STRONG NORTHERLY FLOW IN PLACE. AT THIS
POINT..TEMPERATURES WILL BE RUNNING TEN TO FIFTEEN DEGREES BELOW
NORMAL IN MOST LOCATIONS ACROSS THE STATE.
HIGH PRESSURE AT THE SURFACE BEGINS TO SHIFT OFF TO THE EAST LATE
FRIDAY ALLOWING A RETURN OF MOIST SOUTHERLY FLOW. SOUTHERLY FLOW
WILL BE DEEP AND MOISTURE WILL INCREASE DRAMATICALLY LATE SATURDAY.
BEGAN TO TREND DEWPOINTS UP AT THIS POINT WITH RAW MODELS SUGGESTING
70 PLUS DEWPOINTS WILL BE IN PLACE ACROSS SW ARKANSAS.
AT THIS POINT THERE STILL REMAINS SOME UNCERTAINTY ON THE SEVERE
WEATHER POTENTIAL. BUT MODEL SOUNDINGS DO SUGGEST SOME STRONGER
THUNDERSTORMS WILL BE POSSIBLE ON SUNDAY ACROSS WESTERN ARKANSAS.
RAINFALL TOTALS WILL GENERALLY BE LIGHT AND LIMITED TO WESTERN
ARKANSAS THROUGH THE FIRST HALF OF THE WEEKEND. RAINFALL CHANCES AND
QPF INCREASE SUNDAY EVENING WITH AN ADDITIONAL ONE TO TWO INCHES
POSSIBLE. WESTERN ARKANSAS HAS BEEN FAIRLY HARD HIT IN THE PAST FEW
WEEKS WITH HEAVY RAIN...AND AN ADDITIONAL ROUND OF HEAVY RAIN WILL
LIKELY BE PROBLEMATIC. THIS IS STILL A FEW DAYS OUT...BUT BEARS
WATCHING IN FUTURE FORECASTS.
&&
.LONG TERM...MONDAY THROUGH WEDNESDAY
NO SIG CHGS WERE MADE TO THE CURRENT FCST AS THE LATEST MODEL TRENDS
CONT TO INDC AN UNSETTLED WX PATTERN ACRS THE MID SOUTH. A
PERSISTENT SWLY FLOW ALOFT WL CONT TO BRING SEVERAL UPR LVL IMPULSES
NEWD THRU AR. THESE FEATURES WL INTERACT WITH THE MOIST AIRMASS IN
PLACE TO PRODUCE GOOD CHCS OF SHRA/TSRA. WITH SOILS ALREADY QUITE
SATURATED...ANY ADDITIONAL RAINFALL WL ONLY ENHANCE THE CHCS OF
ADDITIONAL FLOODING OVR MUCH OF THE AREA.
SOME OF THE MODELS DO INDC THAT THE UPR PATTERN WL DE-AMPLIFY OVR
THE SRN STATES HEADING INTO THE MIDDLE OF NEXT WEEK. THIS WL RESULT
IN DRIER CONDS FOR THE FA.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 65 47 68 54 / 10 10 0 20
CAMDEN AR 71 55 74 59 / 30 10 10 20
HARRISON AR 65 46 65 51 / 10 10 30 30
HOT SPRINGS AR 71 53 69 58 / 20 10 20 20
LITTLE ROCK AR 70 53 72 58 / 10 10 10 20
MONTICELLO AR 68 53 73 60 / 30 10 10 10
MOUNT IDA AR 71 51 66 57 / 20 10 30 20
MOUNTAIN HOME AR 66 46 66 51 / 10 10 10 20
NEWPORT AR 65 48 70 56 / 10 10 0 10
PINE BLUFF AR 68 53 72 59 / 20 10 10 20
RUSSELLVILLE AR 71 52 68 56 / 10 10 30 20
SEARCY AR 67 48 72 54 / 10 10 10 20
STUTTGART AR 67 52 72 59 / 20 10 10 20
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...65 / LONG TERM...44
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1044 PM PDT WED MAY 20 2015
.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.
&&
.DISCUSSION...AS OF 9:00 PM PDT WEDNESDAY...UPPER LEVEL TROUGH JUST
WEST OF SAN FRANCISCO BROUGHT ANOTHER DAY OF COOL TEMPERATURES TO
THE AREA. STRATUS BURNED OFF IN SOME AREAS THIS AFTERNOON BUT OAK
SOUNDING SHOWS A DEEP MARINE LAYER AROUND 3000 FEET SO LOW CLOUDS
WILL REDEVELOP AND EXTEND WELL INLAND TONIGHT.
A STRONG DISTURBANCE APPROACHING THE BACK SIDE OF THE TROUGH WILL
INTENSIFY THE TROUGH AND PUSH IT TOWARDS SOUTHERN CALIFORNIA ON THURSDAY.
THIS WILL HELP DEEPEN THE MARINE LAYER EVEN MORE ON THURSDAY...TO
THE POINT WHERE THERE COULD BE LOCAL DRIZZLE OR LIGHT SHOWERS.
THIS ALSO RENEWS SLIGHT CHANCES OF SHOWERS OR THUNDERSTORMS OVER
THE MOUNTAINS WITH THE BEST CHANCES OVER THE SAN BENITO COUNTY
MOUNTAINS. THE LATEST HRRR AND WRF MODELS SHOW SCATTERED PRECIP
AMOUNTS OF 1 TO 3 HUNDREDTHS OF AN INCH NEAR THE COAST AND LIGHT
CONVECTIVE PRECIP IN THE SAN BENITO COUNTY MOUNTAINS.
SLIGHT PRECIP CHANCES CONTINUE INTO FRIDAY AS THE LOW MOVES INLAND
OVER SOUTHERN CALIFORNIA BUT THUNDERSTORM CHANCES WILL BE
DIMINISHED ON THE BACK SIDE OF THE LOW. PRECIP CHANCES END FRIDAY
NIGHT.
PREVIOUS MODEL RUNS INDICATED AN UPPER LEVEL RIDGE BUILDING OFF
THE COAST THIS WEEKEND BUT LATEST MODELS ARE BRINGING ANOTHER
UPPER LEVEL DISTURBANCE ALONG THE BACK SIDE OF THE LOW THROUGH
THE NORTHERN CALIFORNIA INTERIOR ON SATURDAY WITH ONLY WEAK
RIDGING SUNDAY AND MONDAY. DRY WEATHER IS STILL EXPECTED AND
TEMPERATURES SHOULD STILL WARM UP SATURDAY THROUGH MONDAY BUT NOT
AS MUCH AS ORIGINALLY THOUGHT.
&&
.AVIATION...AS OF 10:44 PM PDT WEDNESDAY...LOW CLOUD ARE FILLING
IN ACROSS THE REGION WITH BORDERLINE IFR/MVFR CIGS BEING REPORTED.
ONSHORE FLOW WILL PREVAIL THROUGH TONIGHT WITH GUSTIER WINDS
FORECAST THURSDAY AFTERNOON. THE LOW SITUATED OVER THE REGION IS
EXPECTED TO SLIDE SOUTH THURSDAY WHICH WILL RESULT IN AREAS OF
DRIZZLE TO VICINITY SHOWERS ALONG THE COAST AND LOCALLY INLAND AS
CIGS LIFT. MODERATE CONFIDENCE.
VICINITY OF KSFO...BORDERLINE IFR/MVFR CIGS EXPECTED THROUGH
TONIGHT. CIGS ARE EXPECTED TO LIFT A BIT THURSDAY RESULTING IN
-DZ AND VCSH. ONSHORE FLOW WILL PREVAIL.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...MVFR CIGS EXPECTED THROUGH MUCH OF
THE FORECAST PERIOD. ONSHORE FLOW WILL CONTINUE. -DZ AND VCSH POSS
THURSDAY MORNING.
&&
.MARINE...AS OF 8:44 PM PDT WEDNESDAY...UNSETTLED WEATHER IS
EXPECTED OVER THE COASTAL WATERS AS A STORM SYSTEM WILL MOVE
THROUGH THE REGION THURSDAY AND FRIDAY. LIGHT TO MODERATE
NORTHERLY WINDS WILL CONTINUE AS THE STORM SYSTEM SLIDES THROUGH.
NORTHERLY WINDS WILL INCREASE FRIDAY AND OVER THE WEEKEND AS THE
NORTHERLY PRESSURE GRADIENT INCREASES.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...NONE.
$$
PUBLIC FORECAST: W PI
AVIATION/MARINE: CW
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
857 PM PDT WED MAY 20 2015
.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.
&&
.DISCUSSION...AS OF 9:00 PM PDT WEDNESDAY...UPPER LEVEL TROUGH JUST
WEST OF SAN FRANCISCO BROUGHT ANOTHER DAY OF COOL TEMPERATURES TO
THE AREA. STRATUS BURNED OFF IN SOME AREAS THIS AFTERNOON BUT OAK
SOUNDING SHOWS A DEEP MARINE LAYER AROUND 3000 FEET SO LOW CLOUDS
WILL REDEVELOP AND EXTEND WELL INLAND TONIGHT.
A STRONG DISTURBANCE APPROACHING THE BACK SIDE OF THE TROUGH WILL
INTENSIFY THE TROUGH AND PUSH IT TOWARDS SOUTHERN CALIFORNIA ON THURSDAY.
THIS WILL HELP DEEPEN THE MARINE LAYER EVEN MORE ON THURSDAY...TO
THE POINT WHERE THERE COULD BE LOCAL DRIZZLE OR LIGHT SHOWERS.
THIS ALSO RENEWS SLIGHT CHANCES OF SHOWERS OR THUNDERSTORMS OVER
THE MOUNTAINS WITH THE BEST CHANCES OVER THE SAN BENITO COUNTY
MOUNTAINS. THE LATEST HRRR AND WRF MODELS SHOW SCATTERED PRECIP
AMOUNTS OF 1 TO 3 HUNDREDTHS OF AN INCH NEAR THE COAST AND LIGHT
CONVECTIVE PRECIP IN THE SAN BENITO COUNTY MOUNTAINS.
SLIGHT PRECIP CHANCES CONTINUE INTO FRIDAY AS THE LOW MOVES INLAND
OVER SOUTHERN CALIFORNIA BUT THUNDERSTORM CHANCES WILL BE
DIMINISHED ON THE BACK SIDE OF THE LOW. PRECIP CHANCES END FRIDAY
NIGHT.
PREVIOUS MODEL RUNS INDICATED AN UPPER LEVEL RIDGE BUILDING OFF
THE COAST THIS WEEKEND BUT LATEST MODELS ARE BRINGING ANOTHER
UPPER LEVEL DISTURBANCE ALONG THE BACK SIDE OF THE LOW THROUGH
THE NORTHERN CALIFORNIA INTERIOR ON SATURDAY WITH ONLY WEAK
RIDGING SUNDAY AND MONDAY. DRY WEATHER IS STILL EXPECTED AND
TEMPERATURES SHOULD STILL WARM UP SATURDAY THROUGH MONDAY BUT NOT
AS MUCH AS ORIGINALLY THOUGHT.
&&
.AVIATION...AS OF 5:00 PM PDT WEDNESDAY...A MIX OF LOW AND MID-
LEVEL CLOUDS PREVAILS ONCE AGAIN TODAY AS A LOW PRESSURE SYSTEM
REMAINS OVER THE AREA. CLEARING IS NOT EXPECTED OVER BAY AREA
TERMINALS THIS AFTERNOON WITH CIGS EXPECTED TO FILL BACK IN THIS
EVENING AND OVERNIGHT. ONSHORE FLOW WILL PREVAIL. THE LOW IS
EXPECTED TO SLIDE SOUTH THURSDAY WHICH WILL RESULT IN AREAS OF
DRIZZLE TO VICINITY SHOWERS ALONG THE COAST AND LOCALLY INLAND AS
CIGS LIFT. MODERATE CONFIDENCE.
VICINITY OF KSFO...MVFR CIGS EXPECTED THROUGH MUCH OF THE FORECAST
PERIOD. ONSHORE FLOW WILL PREVAIL. -DZ AND VCSH POSS TOMORROW MORNING.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...MVFR CIGS EXPECTED TO RETURN THIS
EVENING AND PERSIST THROUGH MUCH OF THE FORECAST PERIOD. ONSHORE
FLOW WILL CONTINUE. -DZ AND VCSH POSS TOMORROW MORNING.
&&
.MARINE...AS OF 01:09 PM PDT WEDNESDAY...LIGHT TO MODERATE
NORTHERLY WINDS ARE EXPECTED OVER THE COASTAL WATERS THROUGH
FRIDAY. A STORM SYSTEM WILL MOVE OVER THE COASTAL WATERS THURSDAY
INCREASING THE CHANCE OF SHOWERS INTO FRIDAY. THE SURFACE PRESSURE
GRADIENT WILL STRENGTHEN FRIDAY EVENING AS THE STORM SYSTEM MOVES
OUT OF THE AREA. THE STRENGTHENING SURFACE PRESSURE GRADIENT WILL
RESULT IN INCREASING WINDS AND DETERIORATING SEA CONDITIONS
THROUGH THE WEEKEND.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...NONE.
$$
PUBLIC FORECAST: W PI
AVIATION: CW
MARINE: MM
VISIT US AT WEATHER.GOV/SANFRANCISCO
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AREA FORECAST DISCUSSION
NWS PUEBLO CO
1141 PM MDT WED MAY 20 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 328 PM MDT WED MAY 20 2015
CURRENT WATER VAPOR IMAGERY AND UPPER AIR ANALYSIS INDICATING A
UPPER RIDGING BUILDING ACROSS THE STATE WITH A BROAD UPPER TROUGH
DIGGING ACROSS THE WEST COAST. WATER VAPOR IMAGERY ALSO INDICATING
AN EMBEDDED SHORT WAVE LIFTING OUT ACROSS THE SOUTHERN GREAT BASIN
WITH ANOTHER ONE ROUNDING THE BASE OF THE TROUGH ACROSS THE SOUTHERN
CALIF COAST ATTM. WARMING ALOFT AND MOIST LOW LEVEL UPSLOPE KEEPING
LOW CLOUDS TRAPPED AND COOL TEMPERATURES IN THE 40S AND 50S ACROSS
THE EASTERN PLAINS AT THIS TIME. REGIONAL SATELLITE AND RADAR DATA
INDICATING INSOLATION ACROSS THE HIGHER TERRAIN TERRAIN WEST OF THE
FRONT RANGE IS HELPING TO DEVELOP ISOLATED SHOWERS AND A FEW
EMBEDDED THUNDERSTORMS THROUGH THE EARLY AFTERNOON...WITH THE BEST
COVERAGE ACROSS THE NORTHERN AND CENTRAL MTS.
TONIGHT...TRANSITORY UPPER RIDGE CONTINUES TO BUILD ACROSS THE STATE
WITH THE PASSING GREAT BASIN EMBEDDED WAVE HELPING TO DEVELOP
CONVECTION THROUGH THE LATE EVENING HOURS...MAINLY OVER THE HIGHER
TERRAIN. LATEST NAM...GFS AND EC ARE BULLISH WITH BRINGING SHOWERS
ACROSS THE STABLE I-25 CORRIDOR...AND HAVE STAYED CLOSER TO THE HRRR
AND RAP WHICH KEEPS BEST CHANCES OF GENERALLY LIGHT RAIN ACROSS EL
PASO COUNTY. MODEL SOUNDINGS INDICATING CLOUDS TO LOWER ACROSS THE
PLAINS AGAIN OVERNIGHT...WITH FOG AND PATCHY DRIZZLE POSSIBLE ALONG
AND WEST OF THE I-25 CORRIDOR.
THURSDAY...SOUTHERLY FLOW ALOFT INCREASES THROUGH THE DAY AS THE
WEST COAST SYSTEM SLOWLY MOVES EAST. LATEST MODELS ARE A TAD SLOWLY
WITH THE SOUTHERN CALIF SHORT WAVE LIFTING OUT ACROSS THE DESERT
SOUTHWEST AND INTO THE ROCKIES...WHICH MAY DELAY THE
ONSET...COVERAGE AND INTENSITY OF SHOWERS AND THUNDERSTORMS ACROSS
THE AREA. AT ANY RATE...WILL SEE SHOWERS AND STORMS DEVELOPING
ACROSS THE HIGHER TERRAIN THROUGH THE AFTERNOON WITH STORMS MOVING
ACROSS THE ADJACENT PLAINS THROUGH THE LATE AFTERNOON AND EARLY
EVENING. SLOWER MOVEMENT OF THE SYSTEM LOOKS TO HINDER MIXING ACROSS
THE EASTERN PLAINS...WITH LOW CLOUDS SLOWLY LIFTING THROUGH THE LATE
MORNING AND AFTERNOON.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 328 PM MDT WED MAY 20 2015
THURSDAY NIGHT AND FRIDAY...AN UPPER LEVEL STORM SYSTEM ACROSS THE
SOUTHWEST US IS FORECAST TO EJECT A RATHER STRONG SHORTWAVE TROUGH
INTO COLORADO. SURFACE FLOW FROM THE SOUTHEAST WITH BRING IN A DEEP
LAYER OF MOISTURE...WHICH WILL BE LIFTED BY THE TERRAIN AND
SHORTWAVE DYNAMICS TO PRODUCE ANOTHER EPISODE OF WIDESPREAD
MODERATE...AND LOCALLY HEAVY RAINFALL TO THE EASTERN MOUNTAINS AND
PLAINS. THE SHOWERS AND STORMS ARE DEPICTED BY THE GFS AND NAM TO
MAINLY OCCUR DURING THE FIRST HALF OF THURSDAY NIGHT...AND QUICKLY
SPREAD NORTH AND EAST DURING THE OVERNIGHT. A FEW LIGHTNING STRIKES
ARE POSSIBLE ACROSS THE CWA WITH ELEVATED INSTABILITY...HOWEVER
SEVERE WEATHER IS UNLIKELY THROUGH THURSDAY NIGHT. GFS IS MORE HEAVY
HANDED WITH PRECIPITATION ACROSS THE I-25 AND EASTERN MOUNTAINS THAN
THE NAM ON THE LATEST RUNS. MORE THAN AN INCH OF RAIN IS POSSIBLE
OVER THE EASTERN HALF OF THE CWA...WITH LOCALLY HIGHER AMOUNTS. WITH
SATURATED GROUND...THE POTENTIAL FOR FLASH FLOODING AND FLOODING IS
THERE. RIVERS AND LARGE CREEKS MAY ALSO EXPERIENCE MORE EROSION
ISSUES. SNOW LEVELS WILL REMAIN HIGH...WITH SEVERAL INCHES OF SNOW
POSSIBLE THROUGH FRIDAY MORNING ABOVE 10 KFT.
IN THE WAKE OF THE SHORTWAVE...SINKING MOTION AND DRYING WILL OCCUR.
MODELS ARE HINTING AT A DRY LINE ACROSS THE FAR EASTERN
PLAINS...WHICH COULD SPARK STRONG TO SEVERE STORMS NEAR THE KANSAS
BORDER. CAPES OVER 1000 J/KG AND 0-6 KM BULK SHEARS ABOVE 50 KNOTS
COULD CAUSE SOME STORM ROTATION. ELSEWHERE ON FRIDAY...ISOLATED
SHOWERS AND STORMS WILL OCCUR ACROSS THE MOUNTAINS FRIDAY AFTERNOON
AND DISSIPATE FRIDAY EVENING.
SATURDAY...THE MAIN UPPER SYSTEM WILL MIGRATE THROUGH THE GREAT
BASIN...WITH SOUTH-SOUTHWEST FLOW ACROSS THE CWA. ISOLATED TO
SCATTERED SHOWERS AND STORMS MAY DEVELOP ACROSS THE MOUNTAINS AND
HIGH VALLEYS...AND THE DRY LINE IS FORECAST TO BE ACROSS THE EASTERN
COUNTIES AGAIN...WITH A RISK OF STRONG TO MARGINALLY SEVERE STORMS
DURING THE AFTERNOON AND EVENING.
SUNDAY AND MONDAY...THE NEXT SYSTEM WILL MOVE ACROSS THE ROCKIES
SUNDAY INTO MONDAY. A WEAK COLD FRONT WILL PUSH THROUGH THE PLAINS
SUNDAY MORNING BRINGING MOISTURE INTO THE REGION. AN UPPER
DISTURBANCE WILL BRING SOME SHOWERS AND STORM TO THE AREA...LASTING
INTO MONDAY AFTERNOON.
TUESDAY AND WEDNESDAY...A MODEST RIDGE MAY BUILD INTO THE
AREA...PROVIDING SOME SUNSHINE...AND ONLY THE POSSIBILITY OF
AFTERNOON AND EVENING ISOLATED SHOWERS AND STORMS. -TLM-
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1137 PM MDT WED MAY 20 2015
UPSLOPE FLOW CONTINUES OVER THE PLAINS OVERNIGHT AND INTO THE
MORNING THURSDAY...WITH IFR/LIFR CONDITIONS AT KCOS AND KPUB IN
FOG AND DRIZZLE UNTIL MIDMORNING. CIGS AND VIS GRADUALLY IMPROVE
DURING THE DAY...THOUGH CONDITIONS WILL LIKELY STAY MVFR OR WORSE
ALL DAY. SHOWERS WILL REDEVELOP AND LAST INTO THE EVENING WITH
FAIRLY WIDESPREAD IFR AGAIN THU EVENING OVER THE MOUNTAINS AND
PLAINS.
AT KALS...VFR CONDITIONS PREVAIL OVERNIGHT AND DURING THE DAY THU
WITH AN INCREASING CHANCE OF -SHRA/-TSRA AFTER 18Z.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...MW
LONG TERM...TM
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS NEW YORK NY
504 AM EDT THU MAY 21 2015
.SYNOPSIS...
WEAK HIGH PRESSURE QUICKLY MOVES EAST TODAY...GIVING WAY TO LOW
PRESSURE THAT PASSES TO THE SOUTH AND EAST TONIGHT. A COLD FRONT
MOVES THROUGH LATE FRIDAY. HIGH PRESSURE BUILDS ACROSS THE AREA
ON SATURDAY...THEN MOVES OFFSHORE EARLY SUNDAY. A WARM FRONT WILL
THEN SLOWLY APPROACH FROM THE SOUTHWEST LATE SUNDAY THROUGH
TUESDAY. THE FRONT MAY LIFT TO THE NORTH WEDNESDAY MORNING...AND
BE FOLLOWED BY A COLD FRONT LATER WEDNESDAY INTO THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
PLENTY OF MID AND HIGH LEVEL CLOUDS THIS MORNING OUT AHEAD OF
UPSTREAM SHORTWAVE WILL LOWER AND THICKEN AS THE DAY PROGRESSES.
THERE COULD BE A FEW PEEKS OF SUN EARLY...BUT MAINLY CLOUDY
CONDITIONS ARE ANTICIPATED.
AT THE SFC...LOW PRESSURE OVER THE APPALACHIANS TO OUR SOUTH WILL
MOVE TOWARD THE MID ATLANTIC COAST LATE TODAY AHEAD OF THE
SHORTWAVE.
SOUTHWEST ZONES...THEN COASTAL ZONES FROM NYC EAST COULD SEE LIGHT
RAIN MOVE IN THIS AFTERNOON. LATEST HRRR SIMULATED
REFLECTIVITY...ALONG WITH HIGH RES ARW/NMM...DOES FORECAST RAIN TO
APPROACH THE AREA...AND CLIP THE SW ZONES THIS AFTERNOON. WILL
MAINTAIN CHANCE POPS DURING THE AFTERNOON...WITH A GENERAL
LOWERING OF POPS AS YOU HEAD NORTHWARD.
WITH PLENTY OF CLOUD COVER IN PLACE...TEMPS WILL STRUGGLE THROUGH
THE 50S...AND INTO THE LOWER 60S. THIS IS BELOW NORMAL BY 5 TO 10
DEGREES...AND IS SUPPORTED BY LATEST MOS NUMBERS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
LARGE UPPER TROUGH/LOW PRESSURE OVER EASTERN CANADA...WITH
SHORTWAVE ENERGY PIN-WHEELING AROUND THE CLOSED LOW...WILL PREVAIL
THIS TIME FRAME.
STRENGTHENING SHORTWAVE ROUNDING THE BASE OF THE LARGE UPPER TROUGH
QUICKLY TRAVERSES FROM WEST TO EAST TONIGHT...PASSING TO THE EAST OF
THE AREA EARLY FRIDAY MORNING. IN RESPONSE...SFC LOW OFF THE MID
ATLANTIC COAST IS EXPECTED TO DEEPEN SLIGHTLY...LOWERING A FEW
MILLIBARS...AS IT TRACKS SOMEWHERE JUST SOUTH AND EAST OF THE
40N/70W BENCHMARK TONIGHT INTO EARLY FRIDAY. IN FACT...CONSENSUS IS
OBSERVED IN LATEST NAM/GFS/SREF MEAN AND ECMWF WITH HANDLING OF THIS
LOW.
PRECIP SHIELD EXTENDS NORTH AND WEST OF THIS SFC LOW...AND EXPANDS
AHEAD OF THE AFOREMENTIONED SHORTWAVE.
AS FOR POPS...WILL CONTINUE TO CARRY HIGH CHANCE TO LIKELY POPS NEAR
THE COAST. THIS BASED ON ANALYSIS OF GFS AND NAM STATISTICAL
MOS...NCEP MODEL PLAN FIELDS...AND SREF PLUMES. IN GENERAL...COASTAL
LOCALES TONIGHT COULD OBSERVE ANYWHERE FROM AROUND A TENTH OF AN
INCH ON AVERAGE. ACROSS NORTHERN ZONES SUCH AS THE LOWER HUDSON
VALLEY AND SW CT...POPS REMAIN LOWER AND QPF WOULD RANGE FROM A
TRACE TO MAYBE A TENTH OF AN INCH.
ANY RAIN DEPARTS EARLY FRIDAY...WITH DRY WEATHER EXPECTED THROUGH
THE MORNING. CLOUDS GIVE WAY TO BRIEF SUNSHINE. BY AFTERNOON...A
COLD FRONT AHEAD OF DIGGING TROUGH APPROACHES LATE. CLOUDS INCREASE
AGAIN...AND A FEW SHOWERS ARE POSSIBLE. NAM MOST AGGRESSIVE IN
DEVELOPING AT LEAST SCATTERED COVERAGE DURING THE LATE AFTERNOON
HOURS...BUT WILL LEAN TOWARD SREF/ECMWF/GFS AND ONLY FORECAST
SLIGHT CHANCE POPS ATTM.
A COOL NIGHT IS EXPECTED TONIGHT...WITH LOWS IN THE 40S TO LOWER
50S. WEST FLOW AND BRIEF WAA FRIDAY WILL RESULT IN NEAR TO
PERHAPS SLIGHTLY ABOVE NORMAL TEMPS IN THE 70 TO 75 DEGREE RANGE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
PLEASANT WEATHER CONDITIONS ARE EXPECTED FOR THE WEEKEND AS HIGH
PRESSURE BUILDS ACROSS THE AREA ON SATURDAY...THEN OFFSHORE SUNDAY
MORNING. HIGH TEMPERATURES ON SATURDAY WILL BE IN THE MID TO UPPER
60S AND LOW TO MID 70S ON SUNDAY. A WARM FRONT LIFTS NORTH ON MONDAY
BRINGING A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS. INSTABILITY
SLOWLY INCREASES THROUGH THIS TIME...SO MENTIONED CHANCE THUNDER ON
TUESDAY FROM NYC NORTH/WEST. THE WARM FRONT SHOULD LIFT TO THE NE BY
WEDNESDAY MORNING...BUT COULD BE FOLLOWED BY A WEAK COLD FRONT OR
PRE-FRONTAL WEDNESDAY AFTERNOON INTO THURSDAY MORNING...WITH CHANCE
OF AFTERNOON SHOWERS AND THUNDERSTORMS ONCE AGAIN WEDNESDAY AND
THURSDAY.
TEMPERATURES WILL SLOWLY WARM UP DURING THE WEEK. WITH TEMPERATURES
STARTING OUT IN THE LOW TO MID 70S ON MONDAY...THEN LOW TO MID 80S
BY MIDWEEK.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
WEAK HIGH PRESSURE GIVES WAY TO LOW PRESSURE PASSING WELL SOUTH
AND EAST OF LONG ISLAND THROUGH TONIGHT.
EXPECTING MAINLY VFR CONDITIONS...ALTHOUGH MVFR CANNOT TOTALLY BE
RULED OUT AT TIMES DURING THE LIGHT RAIN LATER TODAY AND THIS
EVENING.
A GENERAL NORTHERLY FLOW LESS THAN 10 KT WILL BECOME MORE
SOUTHERLY AT 10-15 KT BEFORE RETURNING TO A MORE NORTHERLY FLOW
LATE TONIGHT WHICH WILL AGAIN LOWER TO LESS THAN 10 KT.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT: HTTP://WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: HIGHER CHANCES FOR LIGHT RAIN AND MVFR AFTER
21Z. TIMING OF MORE SOUTHERLY WIND COULD BE OFF BY 1-2 HOURS.
KLGA FCSTER COMMENTS: HIGHER CHANCES FOR LIGHT RAIN AND MVFR AFTER
21Z. TIMING OF MORE SOUTHERLY WIND COULD BE OFF BY 1-2 HOURS.
KEWR FCSTER COMMENTS: HIGHER CHANCES FOR LIGHT RAIN AND MVFR AFTER
21Z. TIMING OF MORE SOUTHERLY WIND COULD BE OFF BY 1-2 HOURS.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: HIGHER CHANCES FOR LIGHT RAIN AND MVFR AFTER
23Z. TIMING OF MORE SOUTHERLY WIND COULD BE OFF BY 1-2 HOURS.
KHPN FCSTER COMMENTS: HIGHER CHANCES FOR LIGHT RAIN AND MVFR AFTER
23Z. TIMING OF MORE SOUTHERLY WIND COULD BE OFF BY 1-2 HOURS.
KISP FCSTER COMMENTS: HIGHER CHANCES FOR LIGHT RAIN AND MVFR AFTER
21Z. TIMING OF MORE SOUTHERLY WIND COULD BE OFF BY 1-2 HOURS.
.OUTLOOK FOR 09Z FRIDAY THROUGH MONDAY...
.FRI-FRI NIGHT...POSSIBLE MVFR EARLY MORNING AND IN AFTERNOON.
OTHERWISE VFR. NW GUSTS 25-30 KT...LOWERING AT NIGHT WITH GUSTS
15-20 KT.
.SAT-SUN NIGHT...VFR. W GUSTS 15-20 KT DURING DAY SAT. SW GUSTS
15-25 KT DURING DAY SUN AND INTO EARLY SUN EVE.
.MON...POSSIBLE MVFR OR LOWER IN RAIN SHOWERS.
&&
.MARINE...
HIGH PRESSURE BRIEFLY BUILDS ACROSS THE WATERS TODAY. AS
SUCH...TRANQUIL WINDS AND SEAS ARE FORECAST. BY TONIGHT...THE HIGH
DEPARTS AND LOW PRESSURE APPROACHES AND TRACKS SOUTH AND EAST OF THE
WATERS. THIS LOW MOVES NORTHEAST AS A COLD FRONT APPROACHES FRIDAY
AFTERNOON. LIGHT NORTHERLY WINDS TONIGHT INTO FRIDAY MORNING TURN
TOWARD BACK TO THE WEST AND INCREASE DURING THE AFTERNOON. THERE
COULD VERY WELL BE 25 TO PERHAPS 30 KT GUSTS NEAR SHORE LATE IN
THE AFTERNOON...ESPECIALLY NY HARBOR AND WESTERN LI SOUND. WILL
HOLD OFF THOUGH ON ANY ADVISORIES ATTM DUE TO LATE 3RD
PERIOD...AND MAINLY A NEAR SHORE CONCERN.
TRANQUIL SEAS TONIGHT BUILDS LATE FRIDAY AFTERNOON IN RESPONSE TO
THE STRENGTHENING WESTERLY WINDS.
TRANQUIL CONDITIONS ARE EXPECTED SATURDAY AND SUNDAY MORNING...AS
HIGH PRESSURE BUILDS ACROSS THE AREA WATERS. SOUTHWEST FLOW
INCREASING TO 15-20 KT MAY BUILD OCEAN SEAS TO 5 FT SUNDAY
AFTERNOON/EVENING...ESPECIALLY FARTHER EAST WHERE A LONGER FETCH
WILL EXIST. OCEAN SEAS FALL BELOW SCA LEVELS BRIEFLY ON
MONDAY...THEN BUILD BACK TO SCA LEVELS ON TUESDAY.
&&
.FIRE WEATHER...
TODAY WILL REMAIN MAINLY CLOUDY AND COOL WITH LIGHT WINDS. SOME RAIN
IS EXPECTED LATE TODAY AND THROUGH TONIGHT...MAINLY ALONG THE COAST.
THEN...DRY WEATHER RETURNS FRIDAY. WEATHER CONDITIONS ON FRIDAY MAY
STILL BE CONDUCIVE TO GROWTH/SPREAD OF ANY FIRES THAT DEVELOP. MIN
RH ARE FORECAST TO BE IN THE 20S AND W-NW WINDS WILL GUST TO 25-30
MPH FRI AFTERNOON. KBDI IS IN THE 100S ACROSS MOST OF SRN CT AND THE
LOWER HUDSON VALLEY AND IN THE 200S ACROSS NYC METRO AND LONG
ISLAND...BUT MAY NOT BE FULLY REPRESENTATIVE OF THE PERSISTENT DRY
CONDITIONS THAT HAVE BEEN IN PLACE.
&&
.HYDROLOGY...
DRY THROUGH THIS MORNING. THEN THERE IS THE POTENTIAL
FOR AROUND A TENTH OF AN INCH OF RAIN ON AVERAGE NEAR THE COAST.
NORTHERN ZONES SUCH AS THE LOWER HUDSON VALLEY AND SRN CT...QPF
WOULD RANGE FROM A TRACE TO MAYBE A TENTH OF AN INCH.
THERE IS A CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS MONDAY
INTO THE MIDDLE OF THE WEEK. MODEL UNCERTAINTIES ON
TIMING/PLACEMENT OF ANY HEAVY RAIN ARE STILL TOO LARGE TO MERIT
MENTION OF SPECIFIC AMOUNTS...AND MAY NOT EVEN PAN PER MODEL
FORECASTS OUT GIVEN THE PERSISTENT DRY PATTERN THAT HAS BEEN IN
PLACE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...FIG/PW
NEAR TERM...PW
SHORT TERM...PW
LONG TERM...FIG
AVIATION...JM
MARINE...FIG/PW
FIRE WEATHER...
HYDROLOGY...FIG/PW
AREA FORECAST DISCUSSION
NWS NEW YORK NY
338 AM EDT THU MAY 21 2015
.SYNOPSIS...
WEAK HIGH PRESSURE QUICKLY MOVES EAST TODAY...GIVING WAY TO LOW
PRESSURE THAT PASSES TO THE SOUTH AND EAST TONIGHT. A COLD FRONT
MOVES THROUGH LATE FRIDAY. HIGH PRESSURE BUILDS ACROSS THE AREA
ON SATURDAY...THEN MOVES OFFSHORE EARLY SUNDAY. A WARM FRONT WILL
THEN SLOWLY APPROACH FROM THE SOUTHWEST LATE SUNDAY THROUGH
TUESDAY. THE FRONT MAY LIFT TO THE NORTH WEDNESDAY MORNING...AND
BE FOLLOWED BY A COLD FRONT LATER WEDNESDAY INTO THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
PLENTY OF MID AND HIGH LEVEL CLOUDS THIS MORNING OUT AHEAD OF
UPSTREAM SHORTWAVE WILL LOWER AND THICKEN AS THE DAY PROGRESSES.
THERE COULD BE A FEW PEEKS OF SUN EARLY...BUT MAINLY CLOUDY
CONDITIONS ARE ANTICIPATED.
AT THE SFC...LOW PRESSURE OVER THE APPALACHIANS TO OUR SOUTH WILL
MOVE TOWARD THE MID ATLANTIC COAST LATE TODAY AHEAD OF THE
SHORTWAVE.
SOUTHWEST ZONES...THEN COASTAL ZONES FROM NYC EAST COULD SEE LIGHT
RAIN MOVE IN THIS AFTERNOON. LATEST HRRR SIMULATED
REFLECTIVITY...ALONG WITH HIGH RES ARW/NMM...DOES FORECAST RAIN TO
APPROACH THE AREA...AND CLIP THE SW ZONES THIS AFTERNOON. WILL
MAINTAIN CHANCE POPS DURING THE AFTERNOON...WITH A GENERAL
LOWERING OF POPS AS YOU HEAD NORTHWARD.
WITH PLENTY OF CLOUD COVER IN PLACE...TEMPS WILL STRUGGLE THROUGH
THE 50S...AND INTO THE LOWER 60S. THIS IS BELOW NORMAL BY 5 TO 10
DEGREES...AND IS SUPPORTED BY LATEST MOS NUMBERS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
LARGE UPPER TROUGH/LOW PRESSURE OVER EASTERN CANADA...WITH
SHORTWAVE ENERGY PIN-WHEELING AROUND THE CLOSED LOW...WILL PREVAIL
THIS TIME FRAME.
STRENGTHENING SHORTWAVE ROUNDING THE BASE OF THE LARGE UPPER TROUGH
QUICKLY TRAVERSES FROM WEST TO EAST TONIGHT...PASSING TO THE EAST OF
THE AREA EARLY FRIDAY MORNING. IN RESPONSE...SFC LOW OFF THE MID
ATLANTIC COAST IS EXPECTED TO DEEPEN SLIGHTLY...LOWERING A FEW
MILLIBARS...AS IT TRACKS SOMEWHERE JUST SOUTH AND EAST OF THE
40N/70W BENCHMARK TONIGHT INTO EARLY FRIDAY. IN FACT...CONSENSUS IS
OBSERVED IN LATEST NAM/GFS/SREF MEAN AND ECMWF WITH HANDLING OF THIS
LOW.
PRECIP SHIELD EXTENDS NORTH AND WEST OF THIS SFC LOW...AND EXPANDS
AHEAD OF THE AFOREMENTIONED SHORTWAVE.
AS FOR POPS...WILL CONTINUE TO CARRY HIGH CHANCE TO LIKELY POPS NEAR
THE COAST. THIS BASED ON ANALYSIS OF GFS AND NAM STATISTICAL
MOS...NCEP MODEL PLAN FIELDS...AND SREF PLUMES. IN GENERAL...COASTAL
LOCALES TONIGHT COULD OBSERVE ANYWHERE FROM AROUND A TENTH OF AN
INCH ON AVERAGE. ACROSS NORTHERN ZONES SUCH AS THE LOWER HUDSON
VALLEY AND SW CT...POPS REMAIN LOWER AND QPF WOULD RANGE FROM A
TRACE TO MAYBE A TENTH OF AN INCH.
ANY RAIN DEPARTS EARLY FRIDAY...WITH DRY WEATHER EXPECTED THROUGH
THE MORNING. CLOUDS GIVE WAY TO BRIEF SUNSHINE. BY AFTERNOON...A
COLD FRONT AHEAD OF DIGGING TROUGH APPROACHES LATE. CLOUDS INCREASE
AGAIN...AND A FEW SHOWERS ARE POSSIBLE. NAM MOST AGGRESSIVE IN
DEVELOPING AT LEAST SCATTERED COVERAGE DURING THE LATE AFTERNOON
HOURS...BUT WILL LEAN TOWARD SREF/ECMWF/GFS AND ONLY FORECAST
SLIGHT CHANCE POPS ATTM.
A COOL NIGHT IS EXPECTED TONIGHT...WITH LOWS IN THE 40S TO LOWER
50S. WEST FLOW AND BRIEF WAA FRIDAY WILL RESULT IN NEAR TO
PERHAPS SLIGHTLY ABOVE NORMAL TEMPS IN THE 70 TO 75 DEGREE RANGE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
PLEASANT WEATHER CONDITIONS ARE EXPECTED FOR THE WEEKEND AS HIGH
PRESSURE BUILDS ACROSS THE AREA ON SATURDAY...THEN OFFSHORE SUNDAY
MORNING. HIGH TEMPERATURES ON SATURDAY WILL BE IN THE MID TO UPPER
60S AND LOW TO MID 70S ON SUNDAY. A WARM FRONT LIFTS NORTH ON MONDAY
BRINGING A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS. INSTABILITY
SLOWLY INCREASES THROUGH THIS TIME...SO MENTIONED CHANCE THUNDER ON
TUESDAY FROM NYC NORTH/WEST. THE WARM FRONT SHOULD LIFT TO THE NE BY
WEDNESDAY MORNING...BUT COULD BE FOLLOWED BY A WEAK COLD FRONT OR
PRE-FRONTAL WEDNESDAY AFTERNOON INTO THURSDAY MORNING...WITH CHANCE
OF AFTERNOON SHOWERS AND THUNDERSTORMS ONCE AGAIN WEDNESDAY AND
THURSDAY.
TEMPERATURES WILL SLOWLY WARM UP DURING THE WEEK. WITH TEMPERATURES
STARTING OUT IN THE LOW TO MID 70S ON MONDAY...THEN LOW TO MID 80S
BY MIDWEEK.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
HIGH PRESSURE BUILDS IN FROM THE WEST THROUGH TONIGHT. LOW
PRESSURE WILL PASS SOUTH OF THE REGION ON THURSDAY.
VFR THROUGH THE TAF PERIOD. LIGHT WINDS LESS THAN 10 KTS WILL
INCREASE THURSDAY WHILE BECOMING MORE SOUTHERLY. WIND SPEEDS
INCREASE TO 10-15 KT FOR THE AFTERNOON AND THEN LOWER AGAIN
THURSDAY NIGHT AS THEY BECOME MORE NORTHERLY.
SOME -RA WILL DEVELOP FOR MOST TERMINALS THURSDAY AFTERNOON AND
EVENING....BUT CATEGORIES WILL REMAIN VFR.
.OUTLOOK FOR 06Z FRIDAY THROUGH MONDAY...
.LATE THU NIGHT...POSSIBLE MVFR IN RAIN. OTHERWISE VFR.
.FRI-FRI NIGHT...POSSIBLE MVFR EARLY. OTHERWISE VFR. NW GUSTS
15-20 KT...POSSIBLY UP TO 25 KT.
.SAT-SUN...VFR. S-SW WIND GUSTS BETWEEN 15-20 KT LATE SUN MORNING
AND SUN AFTERNOON.
.MON...CHANCE OF MVFR OR LOWER IN RAIN.
&&
.MARINE...
HIGH PRESSURE BRIEFLY BUILDS ACROSS THE WATERS TODAY. AS
SUCH...TRANQUIL WINDS AND SEAS ARE FORECAST. BY TONIGHT...THE HIGH
DEPARTS AND LOW PRESSURE APPROACHES AND TRACKS SOUTH AND EAST OF THE
WATERS. THIS LOW MOVES NORTHEAST AS A COLD FRONT APPROACHES FRIDAY
AFTERNOON. LIGHT NORTHERLY WINDS TONIGHT INTO FRIDAY MORNING TURN
TOWARD BACK TO THE WEST AND INCREASE DURING THE AFTERNOON. THERE
COULD VERY WELL BE 25 TO PERHAPS 30 KT GUSTS NEAR SHORE LATE IN
THE AFTERNOON...ESPECIALLY NY HARBOR AND WESTERN LI SOUND. WILL
HOLD OFF THOUGH ON ANY ADVISORIES ATTM DUE TO LATE 3RD
PERIOD...AND MAINLY A NEAR SHORE CONCERN.
TRANQUIL SEAS TONIGHT BUILDS LATE FRIDAY AFTERNOON IN RESPONSE TO
THE STRENGTHENING WESTERLY WINDS.
TRANQUIL CONDITIONS ARE EXPECTED SATURDAY AND SUNDAY MORNING...AS
HIGH PRESSURE BUILDS ACROSS THE AREA WATERS. SOUTHWEST FLOW
INCREASING TO 15-20 KT MAY BUILD OCEAN SEAS TO 5 FT SUNDAY
AFTERNOON/EVENING...ESPECIALLY FARTHER EAST WHERE A LONGER FETCH
WILL EXIST. OCEAN SEAS FALL BELOW SCA LEVELS BRIEFLY ON
MONDAY...THEN BUILD BACK TO SCA LEVELS ON TUESDAY.
&&
.FIRE WEATHER...
TODAY WILL REMAIN MAINLY CLOUDY AND COOL WITH LIGHT WINDS. SOME RAIN
IS EXPECTED LATE TODAY AND THROUGH TONIGHT...MAINLY ALONG THE COAST.
THEN...DRY WEATHER RETURNS FRIDAY. WEATHER CONDITIONS ON FRIDAY MAY
STILL BE CONDUCIVE TO GROWTH/SPREAD OF ANY FIRES THAT DEVELOP. MIN
RH ARE FORECAST TO BE IN THE 20S AND W-NW WINDS WILL GUST TO 25-30
MPH FRI AFTERNOON. KBDI IS IN THE 100S ACROSS MOST OF SRN CT AND THE
LOWER HUDSON VALLEY AND IN THE 200S ACROSS NYC METRO AND LONG
ISLAND...BUT MAY NOT BE FULLY REPRESENTATIVE OF THE PERSISTENT DRY
CONDITIONS THAT HAVE BEEN IN PLACE.
&&
.HYDROLOGY...
DRY THROUGH THIS MORNING. THEN THERE IS THE POTENTIAL
FOR AROUND A TENTH OF AN INCH OF RAIN ON AVERAGE NEAR THE COAST.
NORTHERN ZONES SUCH AS THE LOWER HUDSON VALLEY AND SRN CT...QPF
WOULD RANGE FROM A TRACE TO MAYBE A TENTH OF AN INCH.
THERE IS A CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS MONDAY
INTO THE MIDDLE OF THE WEEK. MODEL UNCERTAINTIES ON
TIMING/PLACEMENT OF ANY HEAVY RAIN ARE STILL TOO LARGE TO MERIT
MENTION OF SPECIFIC AMOUNTS...AND MAY NOT EVEN PAN PER MODEL
FORECASTS OUT GIVEN THE PERSISTENT DRY PATTERN THAT HAS BEEN IN
PLACE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...FIG/PW
NEAR TERM...PW
SHORT TERM...PW
LONG TERM...FIG
AVIATION...JM
MARINE...FIG/PW
FIRE WEATHER...
HYDROLOGY...FIG/PW
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
337 AM EDT THU MAY 21 2015
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL TRACK SOUTH AND EAST OF OUR REGION LATE
TODAY AND TONIGHT, THEN A COLD FRONT CROSSES OUR AREA LATER FRIDAY.
HIGH PRESSURE BUILDS IN SATURDAY BUT THEN SHIFTS OFFSHORE SATURDAY
NIGHT AND SUNDAY. THE NEXT COLD FRONT DROPS INTO OUR AREA SUNDAY
NIGHT INTO MONDAY, THEN AS LOW PRESSURE TRACKS FROM THE PLAINS TO
THE GREAT LAKES REGION THE FRONT LIFTS BACK NORTH AS A WARM FRONT
LATE MONDAY INTO TUESDAY. A COLD FRONT IS FORECAST TO REMAIN WELL TO
OUR WEST DURING WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
TODAY...HPC QPF AND 00Z/21 MODEL CONSENSUS HAS THE NORTHERN EDGE
OF THE MEASURABLE RAIN TODAY NEAR I-95. THIS 330AM FORECAST THEN
TAKES INTO ACCOUNT THE HRRR AS WELL AS THE NARRE THROUGH THIS
MORNING. CONFIDENCE ON TEMPS/POPS IS BELOW AVERAGE FROM SE PA
ACROSS CENTRAL NJ WHERE GREATEST UNCERTAINTY EXISTS (KPHL-KTTN).
NO RAIN IS EXPECTED IN NE PA AND NNJ TODAY.
LIGHT WIND WILL BE N-NE THIS MORNING THEN THIS AFTN BECOMES LIGHT
SOUTH IN THE NORTH AND REMAINING E-NE ACROSS ACROSS THE SOUTH.
WARMEST TEMPS MAY BE IN NNJ TODAY WHERE NO RAIN IS FCST.
FCST BASED ON A GENERAL 50 50 BLEND OF 00Z/21 NAM/GFS MOS.
CAUSE OF THE RAIN AND CLOUD COVER: INSTABILITY BURST WITH SLY FLOW
WAA AHEAD OF A RELATIVELY STRONG 500MB SHORT WAVE MOVING ESEWD
FROM THE MIDWEST THIS MORNING AND ARRIVING IN THE UPPER OHIO
VALLEY THIS EVENING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
LEFTOVER RAIN ALONG THE COAST AND A CHANCE OF A PERIOD OF RAIN
ELSEWHERE EARLY, THEN CLEARING TOWARD DAWN AS THE RELATIVELY STRONG
500MB SHORT WAVE SEEN AS AN -80M 12 HR HFC PASSES THROUGH E PA
REACHING LI BY DAYBREAK FRIDAY.
PATCHY FOG POSSIBLE TOWARD DAWN IF IT CLEARS FAST ENOUGH AND IT
REMAINS DECOUPLED THROUGH THE NIGHT.
LIGHT WIND TREND W-NW OVERNIGHT.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
THE SYNOPTIC SETUP IS COMPRISED OF A CLOSED LOW ACROSS EASTERN
CANADA THAT SHIFTS EASTWARD FRIDAY AND OVER THE WEEKEND AS ENERGY
STARTS TO EJECT INTO THE CENTRAL AND SOUTHERN PLAINS. THE LATTER
WILL TEND TO BUILD A RIDGE FROM NEAR FLORIDA NORTHWESTWARD TOWARD
THE MIDWEST SATURDAY INTO MONDAY. THE RIDGE THEN STRENGTHENS SOME AS
IT SHIFTS EASTWARD MONDAY AND TUESDAY, HOWEVER IT SHOULD FLATTEN
SOME ON ITS NORTHERN SIDE. THE MAIN FEATURE OF INTEREST IS A COLD
FRONT THAT DROPS DOWN LATE SUNDAY INTO MONDAY, BUT THEN IT LIFTS
BACK NORTH AS A WARM FRONT AS THE RIDGE BUILDS. IT LOOKS TO TURN
RATHER WARM TO EVEN HOT NEXT WEEK AS THE UPPER-LEVEL RIDGE IS IN
PLACE. WE USED A MODEL BLEND FOR FRIDAY THROUGH SUNDAY, THEN THE 00Z
WPC GUIDANCE WITH CONTINUITY THEREAFTER. SOME TWEAKS WERE THEN MADE
FOLLOWING ADDITIONAL COLLABORATION WITH OUR NEIGHBORING OFFICES.
FOR FRIDAY AND SATURDAY...THE CLOSED LOW TO OUR NORTH IS FORECAST TO
BE SHIFTING EASTWARD DURING THIS TIME FRAME AS ENERGY EJECTS INTO
THE CENTRAL AND SOUTHERN PLAINS. THIS WILL TAKE SURFACE LOW PRESSURE
INTO THE CANADIAN MARITIMES FRIDAY AND A COLD FRONT THROUGH OUR AREA
LATE IN THE DAY. WHILE THERE IS SOME INCREASE IN MOISTURE AHEAD OF
THE FRONT AND ALSO SOME LOWER LEVEL INSTABILITY FORECAST, THE DEEP
WESTERLY FLOW SHOULD TEND TO LIMIT THE CONVERGENCE. WHILE SOME
ISOLATED SHOWERS CANNOT BE RULED OUT, WE OPTED TO KEEP THE FORECAST
FRIDAY DRY ATTM. THE PRESSURE GRADIENT TIGHTENS WITH BREEZY
CONDITIONS DURING FRIDAY, THEN THIS GRADUALLY RELAXES LATER FRIDAY
NIGHT AND SATURDAY AS SURFACE HIGH PRESSURE MOVES IN. A MUCH DRIER
AIRMASS FOLLOWS THE FRONT, AND THIS WILL SET THE STAGE FOR A CHILLY
FRIDAY NIGHT AND EARLY SATURDAY. THERE COULD BE SOME FROST FORMATION
EARLY SATURDAY MORNING ACROSS PORTIONS OF THE NORTHERN ZONES,
PENDING WE DECOUPLE. FOR NOW, WE INCLUDED A PATCHY FROST MENTION.
HIGH PRESSURE THEN BEGINS TO SHIFT OFFSHORE SATURDAY NIGHT AS
RIDGING BUILDS TO OUR WEST.
FOR SUNDAY AND MONDAY...A RIDGE TO OUR WEST WILL GRADUALLY BUILD
EASTWARD. SOME ENERGY SLIDING SOUTHEASTWARD ACROSS NEW ENGLAND WILL
DROP A COLD FRONT INTO OUR AREA SUNDAY NIGHT AND MONDAY. THIS
FEATURE GENERALLY LOOKS TO BE ON THE WEAK SIDE, AND THERE IS SOME
GUIDANCE THAT HOLDS THIS FRONT FARTHER TO THE NORTH IN THE FORM OF A
WARM FRONT. THE FRONT DOES NOT LOOK TO STAY IN PLACE LONG AS THE
BUILDING RIDGE ALOFT ALONG WITH SURFACE HIGH PRESSURE TO OUR EAST
WILL HELP REINFORCE A SOUTHWESTERLY FLOW. THEREFORE THE BOUNDARY
SHOULD MOVE NORTH AS A WARM FRONT DURING MONDAY AND MONDAY NIGHT.
THERE MAY BE SOME CONVECTION RIDING ALONG OR NEAR THIS FRONT,
HOWEVER THIS MAY NOT BE UNTIL LATE MONDAY AS THE RIDGE AXIS MOVES
ACROSS. A WARMER AIRMASS SHOULD OVERSPREAD THE AREA ESPECIALLY
MONDAY AS AN EXPANDING WARM SECTOR MOVES NORTH, AND SOME INCREASE IN
THE DEW POINTS WILL ALSO OCCUR.
FOR TUESDAY AND WEDNESDAY...WE SHOULD BE IN THE WARM SECTOR DURING
THIS TIME FRAME AS A SHORT WAVE ALOFT AND SURFACE LOW TRACKS TO OUR
NORTH, WHICH WILL FLATTEN THE RIDGE SOME. WHILE THE SURFACE COLD
FRONT IS CURRENTLY FORECAST TO STAY TO OUR WEST, SOME CONVECTION
CANNOT BE RULED OUT AS THERE ARE SOME INDICATIONS OF A LEE SIDE
TROUGH DEVELOPING IN THE PRESENCE OF A WARM TO HOT AIRMASS ALONG
WITH AN INCREASE IN THE HUMIDITY. SOME PLACES HAVE A GOOD CHC OF
REACHING 90 DEGREES EACH AFTERNOON.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THROUGH 12Z...VFR. AREAS OF CIGS AOA 20000 FT LOWER TO NEAR 10000
FT AT 12Z. WIND NNW BECOMING NNE WITH GUSTS 10-15 KT FROM THE I-95
CORRIDOR EASTWARD INCLUDING KPHL GROUP OF TAFS.
AFTER 12Z TODAY...VFR CIGS. LIGHT RAIN IS FORECAST TO SPREAD INTO
OUR REGION FROM THE WEST AND SOUTHWEST AROUND 1500Z. THE RAIN IS
EXPECTED TO REMAIN SOUTH OF KRDG AND KABE. A PERIOD OF LIGHT RAIN
IS ANTICIPATED FOR KILG, KPHL, KPNE AND KTTN DURING THE AFTN WITH
THE CATEGORICAL RAIN PROBABILITY RESTRICTED TO KILG. CONDITIONS
SHOULD REMAIN IN THE VFR CATEGORY AT THOSE LOCATIONS WITH CEILINGS
STAYING ABOVE 3000 FEET AND VISIBILITY VALUES STAYING ABOVE 5
MILES.
THE RAIN IS FORECAST TO HAVE A GREATER IMPACT ON KMIV AND KACY
THAN ON OUR TAF SITES TO THE NORTH. CONDITIONS MAY DROP TO MVFR AT
KMIV AND KACY THIS THURSDAY AFTERNOON.
AFTER THIS MORNINGS LIGHT NE WIND TO START, A LIGHT SOUTHWEST
WIND MAY DEVELOP AT KRDG, KABE, KTTN, KPNE, KPHL AND KILG DURING
MIDDAY. THE WIND MAY REMAIN VARIABLE AT KMIV AND KACY OR IT COULD
RESETTLE INTO THE NORTHEAST OR EAST DURING THE AFTERNOON HOURS AT
THOSE LOCATIONS.
TONIGHT...MOSTLY VFR CIGS; ALTHOUGH, SOME LINGERING RAIN/SHWRS
MAY MEAN SOME SUB-VFR THROUGH THE FIRST PART OF THE NIGHT MAINLY
FROM AROUND KMIV/KACY AND SOUTH. LIGHT WIND TREND W-NW OVERNIGHT.
OUTLOOK...
FRIDAY...VFR OVERALL. A COLD FRONT MOVES THROUGH LATER IN THE DAY
WITH PERHAPS AN ISOLATED BRIEF SHOWER. WEST WINDS BECOMING NORTHWEST
AND GUSTING UP TO 25 KNOTS MAINLY DURING THE AFTERNOON AND EVENING,
THEN DIMINISHING.
SATURDAY...VFR. NORTHWEST WINDS AROUND 10 KNOTS.
SUNDAY...VFR. SOUTHWEST WINDS 10 TO 15 KNOTS, THEN TENDING TO BECOME
LIGHT AND VARIABLE AT NIGHT AS A FRONT DROPS NEAR OR INTO THE AREA.
MONDAY...MAINLY VFR. LIGHT AND VARIABLE WINDS BECOMING SOUTHWEST
AROUND 10 KNOTS. A FEW SHOWERS AND THUNDERSTORMS ARE POSSIBLE
ESPECIALLY IN THE AFTERNOON.
&&
.MARINE...
SAFE BOATING WEEK CONTINUES THROUGH FRIDAY MORNING.
THERE IS A NEW USCG SAFETY APP THAT SHOULD BE OF VALUE TO
MARINERS AND WAS JUST UNVEILED THIS WEEK:
HTTP:/WWW.USCG.MIL/MOBILE
THIS APP PROVIDES ADDITIONAL SAFE BOATING RESOURCES FOR MOBILE DEVICE
USERS. WHEN LOCATION ENABLED, USERS CAN RECEIVE THE LATEST WEATHER
REPORTS FROM THE CLOSEST NOAA BUOY AS WELL AS REPORT THE LOCATION
OF A HAZARD ON THE WATER. IT FEATURES AN EMERGENCY ASSISTANCE
BUTTON, WHICH CAN CALL THE CLOSEST CG COMMAND CENTER.
THE FORECAST:
ISSUING SCA FOR THE DE BAY ATLC WATERS TONIGHT. NCAROLINA LOW
INTENSIFIES IN ITS DEPARTURE AND SHOULD DEVELOP MARGINAL 5 FT
HAZARDOUS SEAS AND A FEW SCA GUSTS AROUND 25 KT OVERNIGHT NEAR
44009.
OTHERWISE NO MARINE HEADLINE ANTICIPATED THROUGH TONIGHT.
NORTHERLY WINDS EARLY TODAY TEND NORTHEAST NORTHEAST-EAST BY
DAYBREAK THEN ONSHORE SOUTHEAST THIS AFTERNOON. WINDS EVENTUALLY BECOMING
NORTHWEST EVERYWHERE LATER THIS THURSDAY NIGHT.
OUTLOOK...
FRIDAY...A COLD FRONT MOVES THROUGH THE AREA LATE IN THE DAY AND THE
EVENING AS LOW PRESSURE MOVES AWAY, WITH A NORTHWEST WIND IN ITS
WAKE. PRIOR TO THIS, SOME GUSTS TO NEAR 25 KNOTS SHOULD LINGER
ACROSS THE FAR SOUTHERN COASTAL WATERS EARLY. THE FORECAST SOUNDINGS
SHOW BETTER MIXING MOSTLY NEARSHORE DURING THE DAY, THEN EXPANDING
TO OFFSHORE AT NIGHT AS COLDER AIR MOVES IN AND THEREFORE A SMALL
CRAFT ADVISORY MAY BE NEEDED FOR LATER FRIDAY NIGHT.
SATURDAY AND SUNDAY...NORTHWEST WIND GUSTS TO 25 KNOTS MAY OCCUR TO
START SATURDAY, OTHERWISE THE CONDITIONS SHOULD BE BELOW ADVISORY
CRITERIA.
MONDAY...A SOUTHWESTERLY FLOW IS ANTICIPATED TO INCREASE SOME,
HOWEVER THE CONDITIONS OVERALL SHOULD BE BELOW ADVISORY CRITERIA.
SOME SHOWERS AND THUNDERSTORMS ARE POSSIBLE.
&&
.FIRE WEATHER...
FOR FRIDAY AFTERNOON, THERE MAY BE THE RISK FOR ENHANCED WILDFIRE
SPREAD AS WEST-NORTHWEST WINDS GUST TO 20-25 MPH AT TIMES. IN
ADDITION, THIS WILL COMBINE WITH RELATIVE HUMIDITY VALUES DROPPING
TO AROUND 30 PERCENT IN SOME AREAS ALONG WITH DRY FINE FUELS. THIS
WILL DEPEND ON HOW MUCH WETTING OCCURS LATER TODAY ESPECIALLY ACROSS
THE SOUTHERN AREAS.
&&
.RIP CURRENTS...
SST`S ABOVE NORMAL AND JUST OFF THE COAST SSTS WELL ABOVE NORMAL
BY ALMOST 3C. THIS IS NOT GOOD ONCE IT TURNS HOT AND BEACHES ARE
UNGUARDED, SWIMMERS MAY TAKE CHANCES AT UNGUARDED LOCATIONS. BE
SMART ABOUT ANY SWIMMING EARLY THIS SEASON. ATLANTIC COASTAL WATER
TEMPS ARE WARMING --UPPER 50S TO MID 60S.
RIP CURRENT AWARENESS WEEK FOR MT HOLLY IS JUNE 7-13 WITH PSAS
VIA PUBLIC INFORMATION STATEMENTS, SOCIAL MEDIA, NOAA WEATHER
RADIO AND ANY MEDIA INTERVIEWS DESIRED (CONTACT OFFICE).
FOR RIP CURRENTS: DESPITE ANTICIPATED PROJECTIONS OF LOW OR
MODERATE RISK THROUGH THE MEMORIAL DAY WEEKEND, EARLY SEASON
FATALITIES OCCUR WHEN SWIMMING AT UNGUARDED TIMES/LOCATIONS.
WEAKER SWIMMERS OR SWIMMING IN AREAS WHERE RIP CURRENTS ARE
STRONGER (JETTIES) CAN QUICKLY BECOME LIFE THREATENING. WHEN
TRAINED LIFEGUARDS ARE NOT NEARBY, TIMELY RESCUE IS MUCH LESS
LIKELY. LETS GET THROUGH THE MONTH OF MAY WITH ALL SWIMMERS SAFE!
SWIM IN THE PRESENCE OF LIFE GUARDS! THANK YOU.
&&
.CLIMATE...
**TOP 10 WARMEST MAY CONTINUES LIKELY IN PORTIONS OF THE FORECAST
AREA**
THE FIRST 19 DAYS OF MAY IN OUR FORECAST AREA WERE AVERAGING WITHIN
ABOUT 1/2 DEGREE OF 7 DEGREES ABOVE NORMAL.
BASED ON THE ENSEMBLE AND A FORECAST THAT IS DETERMINISTICALLY
CONSERVATIVE INCLUDING OUR 330 PM MAY 20 PROJECTIONS THROUGH THE
27TH AND THEN THE 00Z/21 CONSERVATIVE FTPRHA THEREAFTER THROUGH
THE 31ST...EASILY OUTLOOKS A TOP 10 WARMEST MAY ON RECORD.
FOR PHILADELPHIA...PERIOD OF RECORD BACK TO 1874. PROJECTING AN
AVG TEMP OF 68.7 TO 69.3 OR AROUND 5 DEGREES ABOVE NORMAL AND AT
THE LEAST, 3RD WARMEST ON RECORD. WARMEST WAS 70.8 IN 1991. THEN
69.2 2004.
FOR ALLENTOWN...POR TO 1922. YESTERDAY WE WERE PROJECTING 65.0 OR
5.1 DEGREES ABOVE NORMAL AND 8TH WARMEST ON RECORD. WARMEST WAS
67.2 IN 1991.
POSTED BECAUSE WE`RE EXPECTING OUR FIRST 90 IN PHILADELPHIA BY THE
MIDDLE OF NEXT WEEK.
NORMAL FIRST DATE OF 90 OR HIGHER.
PHILADELPHIA MAY 29
ALLENTOWN MAY 30
WILMINGTON JUNE 4
ATLANTIC CITY JUNE 11.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 8 AM EDT
FRIDAY FOR ANZ455.
&&
$$
SYNOPSIS...GORSE
NEAR TERM...DRAG
SHORT TERM...DRAG
LONG TERM...GORSE
AVIATION...DRAG/GORSE
MARINE...DRAG/GORSE
FIRE WEATHER...GORSE
RIP CURRENTS...DRAG
CLIMATE...DRAG
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
238 AM EDT THU MAY 21 2015
.SYNOPSIS...
WEAK HIGH PRESSURE PREVAILS OVER THE MID ATLANTIC STATES EARLY TODAY.
LOW PRESSURE INN THE CAROLINAS WILL STRENGTHEN AS IT MOVES NORTHEASTWARD
OUT TO SEA THIS EVENING. A WEAK COLD FRONT WILL CROSS THE AREA FRIDAY,
FOLLOWED BY HIGH PRESSURE RETURNING ACROSS THE REGION FRIDAY NIGHT
THROUGH SATURDAY, BEFORE PROGRESSING OFFSHORE SUNDAY. ORGANIZING
LOW PRESSURE ACROSS THE CENTRAL UNITED STATES WILL ALLOW A WARM
FRONT TO LIFT NORTH THROUGH THE REGION MONDAY, AND A COLD FRONT IS
FORECAST TO APPROACH FROM THE WEST TUESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
TODAY...HPC QPF AND 00Z/21 MODEL CONSENSUS HAS THE NORTHERN EDGE
OF THE MEASURABLE RAIN TODAY NEAR I-95. THIS 330AM FORECAST THEN
TAKES INTO ACCOUNT THE HRRR AS WELL AS THE NARRE THROUGH THIS
MORNING. CONFIDENCE ON TEMPS/POPS IS BELOW AVERAGE FROM SE PA
ACROSS CENTRAL NJ WHERE GREATEST UNCERTAINTY EXISTS (KPHL-KTTN).
NO RAIN IS EXPECTED IN NE PA AND NNJ TODAY.
LIGHT WIND WILL BE N-NE THIS MORNING THEN THIS AFTN BECOMES LIGHT
SOUTH IN THE NORTH AND REMAINING E-NE ACROSS ACROSS THE SOUTH.
WARMEST TEMPS MAY BE IN NNJ TODAY WHERE NO RAIN IS FCST.
FCST BASED ON A GENERAL 50 50 BLEND OF 00Z/21 NAM/GFS MOS.
CAUSE OF THE RAIN AND CLOUD COVER: INSTABILITY BURST WITH SLY FLOW
WAA AHEAD OF A RELATIVELY STRONG 500MB SHORT WAVE MOVING ESEWD
FROM THE MIDWEST THIS MORNING AND ARRIVING IN THE UPPER OHIO
VALLEY THIS EVENING.
&&
.SHORT TERM /TONIGHT/...
LEFTOVER RAIN ALONG THE COAST AND A CHANCE OF A PERIOD OF RAIN
ELSEWHERE EARLY, THEN CLEARING TOWARD DAWN AS THE RELATIVELY STRONG
500MB SHORT WAVE SEEN AS AN -80M 12 HR HFC PASSES THROUGH E PA
REACHING LI BY DAYBREAK FRIDAY.
PATCHY FOG POSSIBLE TOWARD DAWN IF IT CLEARS FAST ENOUGH AND IT
REMAINS DECOUPLED THROUGH THE NIGHT.
LIGHT WIND TREND W-NW OVERNIGHT.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
ANOTHER WEAK SURFACE LOW PRESSURE WILL BE TRACKING TOWARD NORTHERN
NEW ENGLAND AND THE CANADIAN MARITIMES THROUGH THE DAYTIME FRIDAY,
WITH ITS ASSOCIATED COLD FRONT EXPECTED TO CROSS OUT REGION FRIDAY
AFTERNOON TO EVENING. WITH VERY LIMITED MOISTURE, WE HAVE
MAINTAINED A DRY FORECAST FRIDAY; ALTHOUGH, WEST- NORTHWEST WINDS
WILL PICK UP IN THE WAKE OF THIS FRONT AS THE PRESSURE GRADIENT
TIGHTENS FOR A TIME. WINDS THEN RELAX LATER FRIDAY NIGHT AND
THROUGH SATURDAY AS AN AREA OF HIGH PRESSURE BUILDS EASTWARD FROM
THE MIDWEST STATES. A COOL FRIDAY NIGHT WITH BELOW AVERAGE
TEMPERATURES IS ANTICIPATED FOR OUR AREA, WITH CLEARING SKIES AND
LIGHT WINDS. OVERNIGHT LOWS WILL RANGE FROM THE LOWER 50S IN THE
SOUTHERN DELMARVA TO THE LOWER 40S ACROSS OUR NORTHERN ZONES AND
PERHAPS EVEN SOME 30S AND PATCHY FROST INTO THE HIGHER TERRAIN OF
THE POCONOS.
LIGHT WINDS, AMPLE SUN, AND NEAR AVERAGE MAY TEMPERATURES ARE
EXPECTED FOR OUR AREA WITH HIGH PRESSURE PASSING OVER THE REGION
SATURDAY. WHILE SUNDAY WILL STILL BE PLEASANT, TEMPERATURES AND
DEWPOINTS WILL BE CREEPING UPWARD A FEW DEGREES AS THE AREA OF HIGH
PRESSURE EASES OFFSHORE AND A RETURN SOUTHWESTERLY FLOW SETS UP OVER
THE REGION. THIS WARMING TREND AND GRADUAL INCREASE IN DEWPOINTS
WILL CONTINUE THEN INTO MONDAY AS AN AREA OF LOW PRESSURE IS
FORECAST TO ORGANIZE OVER THE CENTRAL UNITED STATES, WITH ITS
ASSOCIATED WARM FRONT LIFTING NORTH THROUGH THE OHIO VALLEY AND OUR
REGION MONDAY. THERE SHOULD BE ENOUGH LIFT AND INSTABILITY AS THIS
BOUNDARY PASSES NORTH FOR SOME SCATTERED SHWR/TSTORM ACTIVITY ACROSS
OUR REGION, AND WE HAVE KEPT CHANCE POPS IN PLACE FOR MEMORIAL DAY,
SOMEWHAT HIGHER CHANCES FOR THE NORTHERN TWO-THIRDS OF THE FORECAST
AREA.
A MORE NOTICEABLE INCREASE IN WARMTH AND HUMIDITY IS THEN EXPECTED
GOING INTO TUESDAY AS OUR REGION WILL BE IN THE WARM SECTOR, WITH
THE SURFACE LOW AND WARM FRONT TO OUR NORTH. BUILDING INSTABILITY
AND A COLD FRONT APPROACHING FROM THE WEST WILL YIELD MORE SCATTERED
SHWR/TSTORM POTENTIAL, AND WE KEPT SOME CHANCE POPS IN PLACE THROUGH
THIS TIMEFRAME. DAYTIME TEMPERATURES SHOULD EASILY REACH INTO THE
MIDDLE AND UPPER 80S FROM THE DELAWARE VALLEY INTO THE DELMARVA,
WITH SOMEWHAT COOLER UPPER 70S/LOW 80S FARTHER NORTH AND ALONG THE
COAST. A LITTLE MORE UNCERTAINTY EXISTS INTO WEDNESDAY WITH REGARDS
TO ISOLATED/SCATTERED PRECIP POTENTIAL DEPENDING ON THE PROGRESS OF
THE FRONTAL BOUNDARY, AND FOR NOW, WE INTRODUCED SOME VERY LOW POPS
INTO THE FORECAST FOR THE WEDNESDAY TIMEFRAME.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THROUGH 12Z...VFR. AREAS OF CIGS AOA 20000 FT LOWER TO NEAR 10000
FT AT 12Z. WIND NNW BECOMING NNE WITH GUSTS 10-15 KT FROM THE I-95
CORRIDOR EASTWARD INCLUDING KPHL GROUP OF TAFS.
AFTER 12Z TODAY...VFR CIGS. LIGHT RAIN IS FORECAST TO SPREAD INTO
OUR REGION FROM THE WEST AND SOUTHWEST AROUND 1500Z. THE RAIN IS
EXPECTED TO REMAIN SOUTH OF KRDG AND KABE. A PERIOD OF LIGHT RAIN
IS ANTICIPATED FOR KILG, KPHL, KPNE AND KTTN DURING THE AFTN WITH
THE CATEGORICAL RAIN PROBABILITY RESTRICTED TO KILG. CONDITIONS
SHOULD REMAIN IN THE VFR CATEGORY AT THOSE LOCATIONS WITH CEILINGS
STAYING ABOVE 3000 FEET AND VISIBILITY VALUES STAYING ABOVE 5
MILES.
THE RAIN IS FORECAST TO HAVE A GREATER IMPACT ON KMIV AND KACY
THAN ON OUR TAF SITES TO THE NORTH. CONDITIONS MAY DROP TO MVFR AT
KMIV AND KACY THIS THURSDAY AFTERNOON.
AFTER THIS MORNINGS LIGHT NE WIND TO START, A LIGHT SOUTHWEST
WIND MAY DEVELOP AT KRDG, KABE, KTTN, KPNE, KPHL AND KILG DURING
MIDDAY. THE WIND MAY REMAIN VARIABLE AT KMIV AND KACY OR IT COULD
RESETTLE INTO THE NORTHEAST OR EAST DURING THE AFTERNOON HOURS AT
THOSE LOCATIONS.
TONIGHT...MOSTLY VFR CIGS; ALTHOUGH, SOME LINGERING RAIN/SHWRS
MAY MEAN SOME SUB-VFR THROUGH THE FIRST PART OF THE NIGHT MAINLY
FROM AROUND KMIV/KACY AND SOUTH. LIGHT WIND TREND W-NW OVERNIGHT.
OUTLOOK...
FRIDAY...VFR CONDITIONS ARE EXPECTED WITH WEST-NORTHWEST WINDS
GUSTING TO AROUND 20 KNOTS DURING THE AFTERNOON.
SATURDAY...CONTINUED VFR WITH LIGHT NORTHWEST WINDS.
SUNDAY...VFR CONDITIONS WITH SOUTHWEST WINDS 10 TO 15 KNOTS.
MONDAY...MAINLY VFR WITH LIGHT SOUTHWEST WINDS; ALTHOUGH, SOME
SCATTERED SHWRS/TSTORMS AND SUB-VFR POSSIBLE AT TIMES.
&&
.MARINE...
SAFE BOATING WEEK CONTINUES THROUGH FRIDAY MORNING.
THERE IS A NEW USCG SAFETY APP THAT SHOULD BE OF VALUE TO
MARINERS AND WAS JUST UNVEILED THIS WEEK:
HTTP:/WWW.USCG.MIL/MOBILE
THIS APP PROVIDES ADDITIONAL SAFE BOATING RESOURCES FOR MOBILE DEVICE
USERS. WHEN LOCATION ENABLED, USERS CAN RECEIVE THE LATEST WEATHER
REPORTS FROM THE CLOSEST NOAA BUOY AS WELL AS REPORT THE LOCATION
OF A HAZARD ON THE WATER. IT FEATURES AN EMERGENCY ASSISTANCE
BUTTON, WHICH CAN CALL THE CLOSEST CG COMMAND CENTER.
THE FORECAST:
ISSUING SCA FOR THE DE BAY ATLC WATERS TONIGHT. NCAROLINA LOW
INTENSIFIES IN ITS DEPARTURE AND SHOULD DEVELOP MARGINAL 5 FT
HAZARDOUS SEAS AND A FEW SCA GUSTS AROUND 25 KT OVERNIGHT NEAR
44009.
OTHERWISE NO MARINE HEADLINE ANTICIPATED THROUGH TONIGHT.
NORTHERLY WINDS EARLY TODAY TEND NORTHEAST NORTHEAST-EAST BY
DAYBREAK THEN ONSHORE SOUTHEAST THIS AFTERNOON. WINDS EVENTUALLY BECOMING
NORTHWEST EVERYWHERE LATER THIS THURSDAY NIGHT.
OUTLOOK...
FRIDAY...WHILE WE HAVE NO HEADLINE ANTICIPATED AT THIS TIME THERE
IS SMALL POTENTIAL FOR AN SCA WEST-NORTHWEST FLOW LATE FRIDAY OR
FRIDAY NIGHT.
SATURDAY AND SUNDAY...CONTINUED SUB-ADVISORY CONDITIONS; ALTHOUGH,
SOME WIND GUSTS TO AROUND 20 KNOTS STILL POSSIBLE AT TIMES.
MONDAY...SUB-ADVISORY ANTICIPATED AT THIS TIME. SOME SCATTERED
SHWRS/TSTORMS EXPECTED WITH LOCALLY HIGHER WINDS/SEAS NEAR
TSTORMS.
&&
.FIRE WEATHER...
FOR FRIDAY AFTERNOON, THERE MAY BE THE RISK FOR ENHANCED WILDFIRE
SPREAD AS A WEST-NORTHWESTERLY WIND GUSTS TO BETWEEN 20 TO 25 MPH AT
TIMES. IN ADDITION, THIS WILL COMBINE WITH RELATIVE HUMIDITY VALUES
NEARING 30 PERCENT IN SOME AREAS ALONG WITH DRY FINE FUELS.
&&
.RIP CURRENTS...
SST`S ABOVE NORMAL AND JUST OFF THE COAST SSTS WELL ABOVE NORMAL
BY ALMOST 3C. THIS IS NOT GOOD ONCE IT TURNS HOT AND BEACHES ARE
UNGUARDED, SWIMMERS MAY TAKE CHANCES AT UNGUARDED LOCATIONS. BE
SMART ABOUT ANY SWIMMING EARLY THIS SEASON. ATLANTIC COASTAL WATER
TEMPS ARE WARMING --UPPER 50S TO MID 60S.
RIP CURRENT AWARENESS WEEK FOR MT HOLLY IS JUNE 7-13 WITH PSAS
VIA PUBLIC INFORMATION STATEMENTS, SOCIAL MEDIA, NOAA WEATHER
RADIO AND ANY MEDIA INTERVIEWS DESIRED (CONTACT OFFICE).
FOR RIP CURRENTS: DESPITE ANTICIPATED PROJECTIONS OF LOW OR
MODERATE RISK THROUGH THE MEMORIAL DAY WEEKEND, EARLY SEASON
FATALITIES OCCUR WHEN SWIMMING AT UNGUARDED TIMES/LOCATIONS.
WEAKER SWIMMERS OR SWIMMING IN AREAS WHERE RIP CURRENTS ARE
STRONGER (JETTIES) CAN QUICKLY BECOME LIFE THREATENING. WHEN
TRAINED LIFEGUARDS ARE NOT NEARBY, TIMELY RESCUE IS MUCH LESS
LIKELY. LETS GET THROUGH THE MONTH OF MAY WITH ALL SWIMMERS SAFE!
SWIM IN THE PRESENCE OF LIFE GUARDS! THANK YOU.
&&
.CLIMATE...
**TOP 10 WARMEST MAY CONTINUES LIKELY IN PORTIONS OF THE FORECAST
AREA**
THE FIRST 19 DAYS OF MAY IN OUR FORECAST AREA WERE AVERAGING WITHIN
ABOUT 1/2 DEGREE OF 7 DEGREES ABOVE NORMAL.
BASED ON THE ENSEMBLE AND A FORECAST THAT IS DETERMINISTICALLY
CONSERVATIVE INCLUDING OUR 330 PM MAY 20 PROJECTIONS THROUGH THE
27TH AND THEN THE 00Z/21 CONSERVATIVE FTPRHA THEREAFTER THROUGH
THE 31ST...EASILY OUTLOOKS A TOP 10 WARMEST MAY ON RECORD.
FOR PHILADELPHIA...PERIOD OF RECORD BACK TO 1874. PROJECTING AN
AVG TEMP OF 68.7 TO 69.3 OR AROUND 5 DEGREES ABOVE NORMAL AND AT
THE LEAST, 3RD WARMEST ON RECORD. WARMEST WAS 70.8 IN 1991. THEN
69.2 2004.
FOR ALLENTOWN...POR TO 1922. YESTERDAY WE WERE PROJECTING 65.0 OR
5.1 DEGREES ABOVE NORMAL AND 8TH WARMEST ON RECORD. WARMEST WAS
67.2 IN 1991.
POSTED BECAUSE WE`RE EXPECTING OUR FIRST 90 IN PHILADELPHIA BY THE
MIDDLE OF NEXT WEEK.
NORMAL FIRST DATE OF 90 OR HIGHER.
PHILADELPHIA MAY 29
ALLENTOWN MAY 30
WILMINGTON JUNE 4
ATLANTIC CITY JUNE 11.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KLINE/DRAG 238
NEAR TERM...DRAG 238
SHORT TERM...DRAG 238
LONG TERM...KLINE
AVIATION...DRAG/KLINE 238
MARINE...DRAG/KLINE 238
FIRE WEATHER...
RIP CURRENTS...
CLIMATE...238
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
140 AM EDT THU MAY 21 2015
.PREV DISCUSSION... /ISSUED 742 PM EDT WED MAY 20 2015/
EVENING UPDATE...
UPPER DISTURBANCE PUSHING INTO NW AL IS SPARKING CONVECTION THERE...
WITH ONGOING CONVECTION STILL NOTED ACROSS EAST AND SE AL. THESE
STORMS MAY PUSH INTO THE COLUMBUS AREA BY 9 PM... BUT EXPECT SOME
WEAKENING... SO MAY BE MOSTLY SHOWERS. THE GREATER CONCERN IS THE
CONVECTION TO THE NORTH WHERE HAS BETTER UPPER SHORT WAVE SUPPORT.
THIS CONVECTION WILL LIKELY SPREAD ISOLATED TO POSSIBLY STILL
SCATTERED THUNDERSTORMS INTO NW GA BETWEEN 9-10 PM... THEN SPREAD
ACROSS THE REST OF NORTH GA THROUGH MIDNIGHT AND COULD PERSIST UNTIL
AROUND 2-3 AM THU MORNING. NO SEVERE STORMS ARE EXPECTED... WITH THE
MAIN THREAT BEING OCCASIONAL CLOUD TO GROUND LIGHTNING AND BRIEF
WIND GUSTS TO 35-40MPH OR SO. WILL UP POPS OVER THE NW ZONES AS GET
MORE CONFIDENT THE CONVECTION WILL HOLD TOGETHER... BUT OTHERWISE...
THE CURRENT FORECAST LOOK ON TRACK. 39
SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
/ISSUED AT 336 PM EDT WED MAY 20 2015/
MAIN FORECAST CONCERN IS WITH PRECIP POTENTIAL THIS EVENING INTO THE
EARLY MORNING AS A SHORTWAVE AND SOME ENHANCED MOISTURE APPROACHES
THE CWA FROM THE WEST. CURRENTLY A BAND OF SHOWERS AND STORMS IS
PUSHING INTO WESTERN ALABAMA AHEAD OF THIS DISTURBANCE WITH A WEAK
TRANSLATED SFC LOW. WHILE SOME HI-RES SOLUTIONS DO NOT APPEAR TO
SUPPORT THIS HOLDING TOGETHER AND PUSHING INTO WEST GA...SOME
PREVIOUS RAP SOLUTIONS SUPPORTED IT AND WILL NEED TO BE CLOSELY
MONITORED ESPECIALLY IF SOME OUTFLOW BOUNDARIES OR OTHER MESOSCALE
FORCING COMES TO AID. THIS MAY RESULT IN UPPING POPS IN WESTERN
PORTIONS OF THE AREA BY THIS EVENING. STILL SOME MLCAPE NEAR 1000
J/KG AND DECENT DCAPE IN PLACE. IF ANY STORM DEVELOPMENT CAN
MUSTER...THERE COULD STILL BE STRONG DOWNDRAFT WINDS EVEN THOUGH IT
IS A SHEAR DEPRIVED ENVIRONMENT. KEEPING BEST CHANCE POPS MAINLY
NORTH OF I-20 CORRIDOR INTO THE EARLY MORNING WITH THE SHORTWAVE
INFLUENCE.
PROGGED THERMAL PROFILES INDICATE GOOD DRYING OF THE COLUMN FOR
THURSDAY AND NOW BETTER AGREEMENT WITH A NOTABLE CAPPING INVERSION
ABOVE 850 MB. HAVE TRIMMED BACK POPS NOW TO ONLY HAVE A SLIGHT
CHANCE IN THE FAR SOUTHERN TIER FOR THE AFTERNOON...OTHERWISE
LOOKING TO STAY TOO DRY AND STABLE. WINDS LOOK TO BE KICKING IN WITH
THE STRENGTHENING PRESSURE GRADIENT AND AFTERNOON MIXING. WHILE
CURRENTLY LOOKING TO STAY A BIT BELOW CRITERIA...WILL NEED TO KEEP
AN EYE ON TRENDS FOR ANY FIRE DANGER CONCERNS WITH ALREADY DRY FUELS
/THOUGH MAY BE ALTERED WITH AFOREMENTIONED PRECIP CHANCES/. TEMPS
THURSDAY LOOK TO HAVE A STRONG GRADIENT WITH BELOW NORMAL HIGHS IN
THE MID/UPPER 70S FOR THE NW TO THE LOW 90S SE.
BAKER
LONG TERM /FRIDAY THROUGH WEDNESDAY/...
/ISSUED AT 336 PM EDT WED MAY 20 2015/
HAVE MADE A FEW MINOR ADJUSTMENTS TO POP AND WEATHER THROUGH THE
WEEKEND. LATEST LONG TERM MODELS HINT AT A MORE PROMINENT SURFACE
HIGH KEEPING MOISTURE TO THE WEST LARGELY AT BAY THROUGH
SUNDAY...WITH ONLY PORTIONS OF WESTERN AND NORTHERN GEORGIA AT
RISK FOR AN ISOLATED STORM. HAVE SCALED POPS BACK SOMEWHAT AS A
RESULT.
31
PREV DISCUSSION... /ISSUED 424 AM EDT WED MAY 20 2015/
LONG TERM PERIOD BEGINS A BIT DRIER AS THE FRONTAL SYSTEM WILL BE
SOUTH AND EAST OF THE AREA. HIGH PRESSURE BUILDING IN FROM THE
NORTHERN PLAINS AND MID WESTERN STATES BECOMES CENTERED OFF THE
MID ATLANTIC COAST AND STAYS THERE THROUGH THE WEEKEND. THIS RIDGE
CONTINUES TO ROTATE AND KEEPS THE DEEPER MOISTURE NORTH AND WEST
OF THE REGION THROUGH THE BEGINNING OF NEXT WEEK. THERE IS STILL
SOME MID AND UPPER LEVEL MOISTURE AROUND THE AREA SO WILL KEEP
SLIGHT CHANCE DIURNALLY DRIVEN POPS IN THE FORECAST DAYS 3-5. BY
TUESDAY THE RIDGE IS BEGINNING TO WEAKEN AND TRANSITION INTO MORE
OF A BERMUDA LIKE RIDGE. THIS WILL ALLOW DEEPER MOISTURE TO MOVE
IN FROM THE WEST ASSOCIATED WITH A WEAKENING FRONTAL BOUNDARY.
LOOKING AT INSTABILITIES INCREASING A BIT TUESDAY/WEDNESDAY ALONG
WITH PWS SO WILL INCREASE TO CHANCE POPS DAYS 6 AND 7.
01
&&
.AVIATION...
06Z UPDATE...
MODELS ARE CONTINUING TO ADD SOME MVFR CIGS TOWARDS DAWN. ANY
CIGS SHOULD CLEAR OUT SHORTLY AFTER SUNRISE...WITH VFR CONDITIONS
EXPECTED THROUGH THE PERIOD. WINDS WILL SHIFT MORE TO THE NW LATER
THIS AFTERNOON WITH FREQUENT GUSTS TO AROUND 20KT.
//ATL CONFIDENCE...06Z UPDATE...
HIGH CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 85 56 81 59 / 10 5 0 5
ATLANTA 80 58 80 63 / 10 0 0 5
BLAIRSVILLE 74 48 74 54 / 30 5 0 5
CARTERSVILLE 79 53 79 56 / 10 0 0 5
COLUMBUS 88 61 84 65 / 10 0 0 5
GAINESVILLE 80 55 78 59 / 10 0 0 5
MACON 89 59 85 63 / 10 0 0 5
ROME 77 52 79 55 / 10 0 0 5
PEACHTREE CITY 83 54 81 60 / 10 0 0 5
VIDALIA 92 65 86 66 / 20 0 0 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
152 AM EDT THU MAY 21 2015
.UPDATE...
ISSUED AT 152 AM EDT THU MAY 21 2015
LIGHT RAIN SHOWERS ARE PROGRESSING ACROSS PORTIONS OF THE REGION
TONIGHT IN ASSOCIATION WITH WEAK WAVE PASSING ACROSS THE OHIO AND
TN VALLEYS. DID BRING POPS DOWN A BIT JUST GIVEN THE LIGHT NATURE
OF THIS ACTIVITY. OTHERWISE MADE SOME MINOR ADJUSTMENTS TOWARDS
LATEST OBS AND TRENDS.
UPDATE ISSUED AT 1100 PM EDT WED MAY 20 2015
LIGHT RAIN SHOWERS ARE MOVING IN FROM THE WEST...HOWEVER THE
RETURNS CONTINUE TO BE VERY LIGHT. THE LAST FEW RUNS OF THE HRRR
HAVE COME IN WITH LESS AREAL COVERAGE THROUGH THE NIGHT. WILL
MAINTAIN LOW END LIKELY POPS...BUT CUT BACK THE QPF...AS A FEW
HUNDREDTHS TO SEVERAL HUNDREDTHS OF AN INCH AT BEST LOOK MORE
REASONABLE AT THIS POINT. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 853 PM EDT WED MAY 20 2015
LIGHT PRECIPITATION IS TRYING TO MAKE IT IN FROM THE WEST...BUT
SO FAR...THE LOW LEVEL DRY AIR HAS BEEN HOLDING IT TO A FEW
SPRINKLES AT BEST. THE LATEST HRRR STILL CONTINUES TO SHOW SOME
BETTER AREAL COVERAGE EVENTUALLY SHIFTING ACROSS EASTERN KENTUCKY
THROUGH THE OVERNIGHT...AS A SHORT WAVE TROUGH DRAWS CLOSER TO
THE AREA. WILL STICK WITH THE CURRENT FORECAST AND MAINLY ADJUST
THE POP TIMING ACCORDING TO THE LATEST RADAR AND SHORT TERM MODEL
GUIDANCE TRENDS. UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 345 PM EDT WED MAY 20 2015
A GENERALLY ZONAL PATTERN WAS IN PLACE FROM THE PLAINS INTO THE
EASTERN CONUS THIS AFTERNOON. A SHORTWAVE TROUGH WAS MOVING EAST
IN THIS FLOW AND WAS OVER THE MS VALLEY REGION. FURTHER TO THE
NORTH OF THE REGION...AN UPPER LEVEL LOW WAS DROPPING SOUTH ACROSS
THE HUDSON BAY REGION. SFC HIGH PRESSURE AND SHORTWAVE RIDGING
THAT IS DEPARTING HAVE BROUGHT MOSTLY SUNNY SKIES TO THE REGION.
HOWEVER...HIGH CLOUDS HAVE BEEN INCREASING THIS AFTERNOON WITH MID
LEVEL CLOUDS AS CLOSE AS CENTRAL KY. RADAR RETURNS HAVE RAIN
SHOWERS ACROSS SOUTHERN IL AND INTO PARTS OF IN AS WELL AS WESTERN
KY AND MIDDLE TN. SOME THUNDERSTORMS ARE OCCURRING OVER SOUTHERN
MIDDLE TN. THESE SHOWERS AND STORMS ARE IN ASSOCIATION WITH THE
SHORTWAVE TROUGH MOVING FROM THE MS VALLEY AND INTO THE LOWER OH
AND TN VALLEY REGIONS. AT THE SFC...A LOW PRESSURE SYSTEM IS
NEARING THE MID MS VALLEY REGION.
THE SHORTWAVE TROUGH IS EXPECTED TO MOVE EAST ACROSS THE REGION
TONIGHT...WITH THE ATMOSPHERE SATURATING FROM THE TOP DOWN.
ANOTHER SHORTWAVE IS EXPECTED TO ROTATE AROUND THE UPPER LOW THAT
WILL MOVE FROM THE HUDSON AND JAMES BAY REGION INTO QUEBEC BY THE
END OF THE PERIOD. THIS SECOND SHORTWAVE WILL USHER IN A COLDER
AND DRIER AIR MASS INTO THE REGION. AT THE SFC...THE LOW PRESSURE
SYSTEM IS EXPECTED TO TRACK EAST JUST TO THE SOUTH OF THE REGION
TONIGHT WITH THIS SYSTEM REACHING THE EASTERN SEABOARD ON THURSDAY
EVENING. MEANWHILE...SFC HIGH PRESSURE WILL BUILD EAST INTO THE
REGION BEHIND THIS SFC LOW FOR THU NIGHT.
THE SHORTWAVE TROUGH MOVING ACROSS THE REGION TONIGHT AND THE SFC
LOW PASSING TO OUR SOUTH COMBINATION SHOULD BRING NUMEROUS SHOWERS
TO THE REGION BY LATE THIS EVENING INTO THE OVERNIGHT HOURS.
DEEPER MOISTURE AND SOMEWHAT BETTER INSTABILITY IS ANTICIPATED
NEAR THE TN BORDER CLOSER TO THE SFC LOW TRACK...AND A STRAY
THUNDERSTORM CANNOT BE RULED OUT NEAR THE TN BORDER AND THE
KY/TN/VA TRI STATE AREA THIS EVENING. THE LAST TWO GFS RUNS BRING
PRECIPITATION TO MUCH OF THE AREA TONIGHT. THE GFS HAD BEEN
CONSISTENTLY DRIER THAN MUCH OF THE GUIDANCE LEADING UP TO THIS
EVENT. WITH THE GFS NOW BRINGING SHOWERS TO THE AREA AS
WELL...POPS HAVE BEEN RAISED INTO THE LIKELY RANGE AS MEASURABLE
PRECIPITATION APPEARS PROBABLE FOR MOST LOCATIONS. LINGERING LOW
LEVEL MOISTURE AND WINDS BRIEFLY GOING UPSLOPE BEHIND THE
DEPARTING LOW WILL BRING THE THREAT FOR LINGERING SHOWERS INTO THE
DAY ON THURSDAY.
HIGH PRESSURE WILL USHER IN A COLDER AND DRIER AIR MASS LATE THU
INTO THU NIGHT...WITH WIDESPREAD LOW TO MID 40S ANTICIPATED. SOME
OF THE COOP MOS GUIDANCE SUGGESTS THAT COLDEST SPOTS IN THE NORTH
COULD REACH 39 OR 40...SO A FEW OF THE NORMALLY COLDER SPOTS MAY
NEED TO BE LOWERED A DEGREE OR TWO AS THU NIGHT APPROACHES.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 315 PM EDT WED MAY 20 2015
NORTHWESTERLY FLOW ALOFT WILL DOMINATE THE REGION AS AN UPPER LEVEL
RIDGE BUILDS INTO EASTERN KENTUCKY AT THE START OF THE PERIOD. BY
THE SECOND HALF OF THE WEEKEND...THIS RIDGE WILL STRENGTHEN AND PUSH
EWD TOWARD THE EAST COAST ALLOWING FOR A TRANSITION TO SOUTHERLY
FLOW AT MID AND UPPER LEVELS. AN ACTIVE WEATHER PATTERN IS THEN IN
STORE FOR EASTERN KENTUCKY AS THE SOUTHERLY FLOW BRINGS AN INCREASE
IN MOISTURE AND A SERIES OF IMPULSES THROUGH THE END OF THE PERIOD.
AT THE SURFACE...THE FIRST PART OF MEMORIAL DAY WEEKEND WILL FEATURE
DRY AND BEAUTIFUL SPRING WEATHER WITH TEMPERATURES TOPPING OUT IN
THE LOW TO MID 70S FRIDAY AND SATURDAY. THE SURFACE RIDGE THEN
SHIFTS EAST OF THE REGION SUNDAY AS THE UPPER LEVEL RIDGE
STRENGTHENS OVER THE SOUTHEASTERN US...ALLOWING FOR MOISTURE AND
CLOUD COVER TO INCREASE. THERE WILL BE CHANCES FOR SHOWERS AND
DIURNALLY DRIVEN CONVECTION SUNDAY AFTERNOON THROUGH WEDNESDAY WITH
INSTABILITY INCREASING EACH DAY. TEMPERATURES WILL BE DEPENDENT ON
CONVECTIVE TIMING/COVERAGE...BUT A GENERAL WARMING TREND FROM THE
70S ON FRIDAY INTO THE MID 80S BY WEDNESDAY IS ANTICIPATED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 134 AM EDT THU MAY 21 2015
SEEING A FEW LIGHT RAIN SHOWERS MOVE ACROSS THE REGION
TONIGHT...HOWEVER WE ARE STRUGGLING GIVEN THE DRIER AIR IN PLACE
AND THE GENERALLY SHEARED OUT SYSTEM. THOSE WHO DID RECEIVE RAIN
WILL HAVE TO BEST CHANCES OF SEEING FALLING CIGS OVERNIGHT WITH A
BIT MORE LOW LEVEL MOISTURE TO PLAY WITH. GENERALLY SLOWLY BRING
MOST SITES TO MVFR BETWEEN 07Z AND 09Z AND RIGHT NOW KEPT WITH
THE LOWER VIS...HOWEVER THINK THE BIGGER RESTRICTION WILL BE THE
CEILINGS FOR MUCH OF THE PERIOD. TOWARD DAWN DO BRING SITES DOWN
TO IFR WITH SOUNDINGS INDICATING THE LOW LEVEL MOISTURE TRAPPED IN
THE LOWER LAYERS AND ALSO INTRODUCED SOME DRIZZLE. DID OPT TO MIX
THIS OUT BY EARLY AFTERNOON TODAY AND BRING TAFS SITES BACK TO
MVFR. OTHERWISE GENERALLY LIGHT WINDS THROUGH THE PERIOD AND
EVENTUALLY COMING OUT OF THE NW THIS AFTERNOON.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...JP
LONG TERM...JVM
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
135 AM EDT THU MAY 21 2015
.UPDATE...
ISSUED AT 1100 PM EDT WED MAY 20 2015
LIGHT RAIN SHOWERS ARE MOVING IN FROM THE WEST...HOWEVER THE
RETURNS CONTINUE TO BE VERY LIGHT. THE LAST FEW RUNS OF THE HRRR
HAVE COME IN WITH LESS AREAL COVERAGE THROUGH THE NIGHT. WILL
MAINTAIN LOW END LIKELY POPS...BUT CUT BACK THE QPF...AS A FEW
HUNDREDTHS TO SEVERAL HUNDREDTHS OF AN INCH AT BEST LOOK MORE
REASONABLE AT THIS POINT. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 853 PM EDT WED MAY 20 2015
LIGHT PRECIPITATION IS TRYING TO MAKE IT IN FROM THE WEST...BUT
SO FAR...THE LOW LEVEL DRY AIR HAS BEEN HOLDING IT TO A FEW
SPRINKLES AT BEST. THE LATEST HRRR STILL CONTINUES TO SHOW SOME
BETTER AREAL COVERAGE EVENTUALLY SHIFTING ACROSS EASTERN KENTUCKY
THROUGH THE OVERNIGHT...AS A SHORT WAVE TROUGH DRAWS CLOSER TO
THE AREA. WILL STICK WITH THE CURRENT FORECAST AND MAINLY ADJUST
THE POP TIMING ACCORDING TO THE LATEST RADAR AND SHORT TERM MODEL
GUIDANCE TRENDS. UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 345 PM EDT WED MAY 20 2015
A GENERALLY ZONAL PATTERN WAS IN PLACE FROM THE PLAINS INTO THE
EASTERN CONUS THIS AFTERNOON. A SHORTWAVE TROUGH WAS MOVING EAST
IN THIS FLOW AND WAS OVER THE MS VALLEY REGION. FURTHER TO THE
NORTH OF THE REGION...AN UPPER LEVEL LOW WAS DROPPING SOUTH ACROSS
THE HUDSON BAY REGION. SFC HIGH PRESSURE AND SHORTWAVE RIDGING
THAT IS DEPARTING HAVE BROUGHT MOSTLY SUNNY SKIES TO THE REGION.
HOWEVER...HIGH CLOUDS HAVE BEEN INCREASING THIS AFTERNOON WITH MID
LEVEL CLOUDS AS CLOSE AS CENTRAL KY. RADAR RETURNS HAVE RAIN
SHOWERS ACROSS SOUTHERN IL AND INTO PARTS OF IN AS WELL AS WESTERN
KY AND MIDDLE TN. SOME THUNDERSTORMS ARE OCCURRING OVER SOUTHERN
MIDDLE TN. THESE SHOWERS AND STORMS ARE IN ASSOCIATION WITH THE
SHORTWAVE TROUGH MOVING FROM THE MS VALLEY AND INTO THE LOWER OH
AND TN VALLEY REGIONS. AT THE SFC...A LOW PRESSURE SYSTEM IS
NEARING THE MID MS VALLEY REGION.
THE SHORTWAVE TROUGH IS EXPECTED TO MOVE EAST ACROSS THE REGION
TONIGHT...WITH THE ATMOSPHERE SATURATING FROM THE TOP DOWN.
ANOTHER SHORTWAVE IS EXPECTED TO ROTATE AROUND THE UPPER LOW THAT
WILL MOVE FROM THE HUDSON AND JAMES BAY REGION INTO QUEBEC BY THE
END OF THE PERIOD. THIS SECOND SHORTWAVE WILL USHER IN A COLDER
AND DRIER AIR MASS INTO THE REGION. AT THE SFC...THE LOW PRESSURE
SYSTEM IS EXPECTED TO TRACK EAST JUST TO THE SOUTH OF THE REGION
TONIGHT WITH THIS SYSTEM REACHING THE EASTERN SEABOARD ON THURSDAY
EVENING. MEANWHILE...SFC HIGH PRESSURE WILL BUILD EAST INTO THE
REGION BEHIND THIS SFC LOW FOR THU NIGHT.
THE SHORTWAVE TROUGH MOVING ACROSS THE REGION TONIGHT AND THE SFC
LOW PASSING TO OUR SOUTH COMBINATION SHOULD BRING NUMEROUS SHOWERS
TO THE REGION BY LATE THIS EVENING INTO THE OVERNIGHT HOURS.
DEEPER MOISTURE AND SOMEWHAT BETTER INSTABILITY IS ANTICIPATED
NEAR THE TN BORDER CLOSER TO THE SFC LOW TRACK...AND A STRAY
THUNDERSTORM CANNOT BE RULED OUT NEAR THE TN BORDER AND THE
KY/TN/VA TRI STATE AREA THIS EVENING. THE LAST TWO GFS RUNS BRING
PRECIPITATION TO MUCH OF THE AREA TONIGHT. THE GFS HAD BEEN
CONSISTENTLY DRIER THAN MUCH OF THE GUIDANCE LEADING UP TO THIS
EVENT. WITH THE GFS NOW BRINGING SHOWERS TO THE AREA AS
WELL...POPS HAVE BEEN RAISED INTO THE LIKELY RANGE AS MEASURABLE
PRECIPITATION APPEARS PROBABLE FOR MOST LOCATIONS. LINGERING LOW
LEVEL MOISTURE AND WINDS BRIEFLY GOING UPSLOPE BEHIND THE
DEPARTING LOW WILL BRING THE THREAT FOR LINGERING SHOWERS INTO THE
DAY ON THURSDAY.
HIGH PRESSURE WILL USHER IN A COLDER AND DRIER AIR MASS LATE THU
INTO THU NIGHT...WITH WIDESPREAD LOW TO MID 40S ANTICIPATED. SOME
OF THE COOP MOS GUIDANCE SUGGESTS THAT COLDEST SPOTS IN THE NORTH
COULD REACH 39 OR 40...SO A FEW OF THE NORMALLY COLDER SPOTS MAY
NEED TO BE LOWERED A DEGREE OR TWO AS THU NIGHT APPROACHES.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 315 PM EDT WED MAY 20 2015
NORTHWESTERLY FLOW ALOFT WILL DOMINATE THE REGION AS AN UPPER LEVEL
RIDGE BUILDS INTO EASTERN KENTUCKY AT THE START OF THE PERIOD. BY
THE SECOND HALF OF THE WEEKEND...THIS RIDGE WILL STRENGTHEN AND PUSH
EWD TOWARD THE EAST COAST ALLOWING FOR A TRANSITION TO SOUTHERLY
FLOW AT MID AND UPPER LEVELS. AN ACTIVE WEATHER PATTERN IS THEN IN
STORE FOR EASTERN KENTUCKY AS THE SOUTHERLY FLOW BRINGS AN INCREASE
IN MOISTURE AND A SERIES OF IMPULSES THROUGH THE END OF THE PERIOD.
AT THE SURFACE...THE FIRST PART OF MEMORIAL DAY WEEKEND WILL FEATURE
DRY AND BEAUTIFUL SPRING WEATHER WITH TEMPERATURES TOPPING OUT IN
THE LOW TO MID 70S FRIDAY AND SATURDAY. THE SURFACE RIDGE THEN
SHIFTS EAST OF THE REGION SUNDAY AS THE UPPER LEVEL RIDGE
STRENGTHENS OVER THE SOUTHEASTERN US...ALLOWING FOR MOISTURE AND
CLOUD COVER TO INCREASE. THERE WILL BE CHANCES FOR SHOWERS AND
DIURNALLY DRIVEN CONVECTION SUNDAY AFTERNOON THROUGH WEDNESDAY WITH
INSTABILITY INCREASING EACH DAY. TEMPERATURES WILL BE DEPENDENT ON
CONVECTIVE TIMING/COVERAGE...BUT A GENERAL WARMING TREND FROM THE
70S ON FRIDAY INTO THE MID 80S BY WEDNESDAY IS ANTICIPATED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 134 AM EDT THU MAY 21 2015
SEEING A FEW LIGHT RAIN SHOWERS MOVE ACROSS THE REGION
TONIGHT...HOWEVER WE ARE STRUGGLING GIVEN THE DRIER AIR IN PLACE
AND THE GENERALLY SHEARED OUT SYSTEM. THOSE WHO DID RECEIVE RAIN
WILL HAVE TO BEST CHANCES OF SEEING FALLING CIGS OVERNIGHT WITH A
BIT MORE LOW LEVEL MOISTURE TO PLAY WITH. GENERALLY SLOWLY BRING
MOST SITES TO MVFR BETWEEN 07Z AND 09Z AND RIGHT NOW KEPT WITH
THE LOWER VIS...HOWEVER THINK THE BIGGER RESTRICTION WILL BE THE
CEILINGS FOR MUCH OF THE PERIOD. TOWARD DAWN DO BRING SITES DOWN
TO IFR WITH SOUNDINGS INDICATING THE LOW LEVEL MOISTURE TRAPPED IN
THE LOWER LAYERS AND ALSO INTRODUCED SOME DRIZZLE. DID OPT TO MIX
THIS OUT BY EARLY AFTERNOON TODAY AND BRING TAFS SITES BACK TO
MVFR. OTHERWISE GENERALLY LIGHT WINDS THROUGH THE PERIOD AND
EVENTUALLY COMING OUT OF THE NW THIS AFTERNOON.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...JP
LONG TERM...JVM
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS CARIBOU ME
352 AM EDT THU MAY 21 2015
.SYNOPSIS...
HIGH PRESSURE TO THE SOUTH WILL MOVE EAST TODAY. ANOTHER COLD
FRONT WILL APPROACH FROM QUEBEC LATER TONIGHT AND MOVING
THROUGH THE REGION ON FRIDAY WITH SHOWERS FOR THE REGION.
CONDITIONS WILL REMAIN UNSETTLED INTO SATURDAY AN UPPER LOW MOVES
ACROSS THE REGION FROM CANADA.
&&
.NEAR TERM /THROUGH TONIGHT/...
ANOTHER COLD FRONT EXPECTED TO AFFECT THE REGION.
06Z SURFACE ANALYSIS SHOWED HIGH PRES OVER NYS SLIDING E. SKIES
WERE GENERALLY CLEAR PER THE LATEST IR SATL IMAGERY W/SOME CLOUDS
SKIRTING NORTHERN AREAS AND ANOTHER BATCH MOVING INTO WESTERN AND
SW AREAS. TEMPERATURES VARYING QUITE A BIT, MEANING LOW LYING
REGIONS HAVE DROPPED BACK INTO THE MID AND UPPER 20S AS WINDS HAVE
DROPPED OFF. ELSEWHERE, TEMPERATURES WERE AVERAGING IN THE 40S
W/WINDS AOA 6 MPH. TEMPERATURES ARE EXPECTED TO DROP OFF BY
SUNRISE W/THE COOL AIR IN PLACE. THOSE CLOUDS ACROSS THE WEST AND
SW WILL INCREASE TODAY AS ANOTHER FRONTAL BOUNDARY SLIDES TOWARDS
THE REGION. AN UPPER DISTURBANCE SEEN IN WATER VAPOR IMAGERY IS
FORECAST BY THE NAM AND GFS TO SWINGS ACROSS THE REGION. LLVL
CONVERGENCE IN THE WESTERN AREAS COMBINED W/SOME WEAK MID LEVEL
FORCING COULD ALLOW FOR A FEW SHOWERS LATER THIS AFTERNOON.
DECIDED TO TAKE A CONSENSUS APCH(NAM/GFS AND HRRR 3KM) AND BROUGHT
20-30% POPS INTO THE WNW AREAS A BIT EARLIER THAN PREVIOUSLY
FORECAST. THE REST OF THE CWA WILL REMAIN DRY. DAYTIME
TEMPERATURES ARE FORECAST TO BE IN THE LOW/MID 60S NORTH AND WEST
TO THE UPPER 60S CENTRAL AND DOWNEAST.
A WAVE OF LOW PRESSURE OVER SOUTHERN QUEBEC IS EXPECTED TO DEVELOP
ON THE FRONTAL BOUNDARY AND MOVE NE ACROSS NW MAINE. SHOWERS ARE
FORECAST TO MOVE INTO NORTHERN AND WESTERN AREAS OVERNIGHT. RAINFALL
AMOUNTS WILL BE LIGHT(<.05"). TEMPERATURES ARE EXPECTED TO BE
WARMER THAN THEY WERE THIS MORNING HOLDING IN THE 40S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
LOW PRESSURE WILL TRACK EAST OF THE GULF OF MAINE DURING FRIDAY.
STEADY RAIN ASSOCIATED WITH THIS LOW SHOULD REMAIN TO THE EAST OF
THE STATE. HOWEVER, SHOWERS ASSOCIATED WITH AN APPROACHING UPPER
LOW FROM THE NORTHWEST AND ATTENDANT COLD FRONT CAN BE EXPECTED ON
FRIDAY. THE COLD FRONT WILL MOVE EAST OF THE DOWN EAST COAST EARLY
FRIDAY EVENING WITH ANY LINGERING SHOWERS PUSHING OFFSHORE.
NORTHWEST WINDS BEHIND THE FRONT WILL USHER IN COLDER AIR FRIDAY
NIGHT. 850MB TEMPS FALL TO AROUND -5C BY 12Z SATURDAY WITH 925 MB
TEMPS DOWN TO AROUND 0C. WITH THE COLD AIR ALOFT WE COULD SEE A
FEW SNOW SHOWERS ACROSS NORTHERN AREAS AS THE 500 MB LOW TRACKS
ACROSS THE REGION. EXPECT GUSTY NORTHWEST WINDS ON SATURDAY AS LOW
PRESSURE REMAINS TO OUR NORTHEAST AND A RIDGE OF HIGH PRESSURE
BUILDS EAST. SKIES WILL BE PARTLY SUNNY ACROSS NORTHERN AND
CENTRAL AREAS WITH THE CHANCE OF A SHOWER AND PARTLY TO MOSTLY
SUNNY SKIES DOWN EAST. HIGHS ON SATURDAY WILL BE BELOW NORMAL FOR
THIS TIME OF YEAR WITH HIGHS EXPECTED TO RANGE FROM THE MID TO
UPPER 50S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
A SHORT WAVE IS EXPECTED TO APPROACH FROM THE NORTHWEST SATURDAY
EVENING AND CROSS THE REGION LATER SATURDAY NIGHT AND INTO EARLY
SUNDAY. EXPECT PARTLY TO MOSTLY CLOUDY SKIES SATURDAY NIGHT WITH
THE CHANCE FOR A SHOWER MAINLY ACROSS NORTHERN AREAS. HIGHS ON
SUNDAY WILL RANGE FROM THE LOW TO MID 60S NORTH AND CENTRAL AND
UPPER 60S TO NEAR 70 DOWN EAST. EXPECT MAINLY CLEAR SKIES SUNDAY
NIGHT FOLLOWED BY A MAINLY SUNNY AND WARM MEMORIAL DAY. CLOUDS
WILL INCREASE MONDAY NIGHT WITH A FEW SHOWERS EXPECTED AS WARM
FRONT LIFTS NORTHEAST TOWARD THE REGION. EXPECT A CHANCE FOR
SHOWERS AND PERHAPS AN ISLD TSTM TUESDAY INTO WEDNESDAY IN ADVANCE
OF A SLOW MOVING COLD FRONT FROM THE NORTHWEST. TEMPERATURES WILL
AVERAGE ABOVE NORMAL THROUGH MID WEEK.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
NEAR TERM: VFR CONDITIONS THROUGH TONIGHT FOR ALL TERMINALS.
SHORT TERM: VFR BUT MVFR IN ANY RAIN SHOWERS FRIDAY AND RAIN/SNOW
SHOWERS FRIDAY NIGHT. VFR CONDITIONS EXPECTED SATURDAY THROUGH
MONDAY.
&&
.MARINE...
NEAR TERM: NO HEADLINES THROUGH TONIGHT. SEAS ARE TO REMAIN 2 TO 3
FT INTO TONIGHT W/WINDS 10 TO 15 KTS.
SHORT TERM: WINDS/SEAS MAY REACH SCA LEVELS FRIDAY NIGHT AND
SATURDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HEWITT/DUDA
MARINE...HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS DULUTH MN
331 AM CDT THU MAY 21 2015
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 330 AM CDT THU MAY 21 2015
QUIET SHORT TERM FORECAST WITH UPPER LEVEL RIDGING BUILDING INTO
THE DAKOTAS...COMPLIMENTED BY BROAD SFC HIGH PRESSURE THROUGH THE
REMAINDER OF THE WEEK.
WINDS WILL BE OUT OF THE NORTH TODAY WITH AFTERNOON GUSTS IN THE
15 TO 20 KT RANGE AS HUDSON BAY LOW DEPARTS TO THE EAST. SKIES
WILL BECOME MOSTLY SUNNY WITH AFTERNOON TEMPERATURES IN THE 60S
TO LOW 70S. CONDITIONS WILL BE COOLER ALONG THE SHORES OF LAKE
SUPERIOR. THE RELATIVELY COOL AIR ALOFT WITH H85 TEMPS IN THE
SINGLE DIGITS WILL RESULT IN DEEP AFTERNOON MIXING TO AROUND 6000
FT...PROMOTING FALLING DEW POINTS/RH VALUES. HAVE LOWERED THE
MINIMUM RELATIVE HUMIDITY TODAY INTO THE 25 TO 30% RANGE ACROSS
THE FORECAST AREA.
FRIDAY WILL AGAIN BE SUNNY AND DRY WITH TEMPERATURES IN THE 60S TO
LOW 70S. WINDS WILL BE LIGHT...BECOMING SOUTHWEST 5 TO 10 MPH IN
THE AFTERNOON INLAND FROM LAKE SUPERIOR.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 312 AM CDT THU MAY 21 2015
A GENERALLY WET PATTERN DEVELOPING OVER THE WEEKEND AND INTO EARLY
NEXT WEEK WITH TEMPERATURES NEAR TO SLIGHTLY WARMER THAN NORMAL.
LARGE DIFFERENCES BETWEEN MODELS AND RUN-TO-RUN LEAD TO SLIGHTLY
LOWER THAN USUAL CONFIDENCE IN THE FORECAST....BUT AM FAIRLY
CONFIDENT IN A WIDESPREAD HALF INCH TO AN INCH OF RAINFALL ACROSS
MUCH OF THE REGION...WITH THE EXCEPTION OF FAR NORTHEAST MINNESOTA
FROM THE IRON EAST ACROSS THE ARROWHEAD REGION WHICH MAY MISS OUT ON
SOME OF THE HIGHER PRECIP AMOUNTS.
ON THE SYNOPTIC SCALE A LONGWAVE TROUGH WILL DEEPEN ACROSS THE
DESERT SOUTHWEST WITH A WEAK RIDGE AXIS OVER THE SOUTHEAST EXTENDING
UP THROUGH THE UPPER MIDWEST...WITH A BROAD AREA OF HIGH PRESSURE
OVER THE MID ATLANTIC STATES. THIS WILL RESULT IN SOUTHERN FLOW AT
LOW LEVELS ACROSS THE CENTRAL PLAINS INTO THE MISSISSIPPI RIVER
VALLEY...RESULTING IN RICH GULF MOISTURE BEING ADVECTED INTO THE
NORTHLAND. LARGE SCALE FORCING FROM MID-LEVEL DISTURBANCES WILL
RESULT IN SHOWERS AND A FEW THUNDERSTORMS LATE SATURDAY BUT MORE SO
SUNDAY INTO MONDAY.
IN GENERAL THERMODYNAMIC PROFILES DO NOT SUPPORT THUNDERSTORMS DUE
TO MID-LEVEL LAPSE RATES...BUT A FEW EMBEDDED STORMS WILL BE
POSSIBLE LATE IN THE WEEKEND INTO EARLY NEXT WEEK. THE POTENTIAL FOR
SEVERE THUNDERSTORMS IS VERY LOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 105 AM CDT THU MAY 21 2015
VFR CONDITIONS EXPECTED AT ALL TERMINALS THROUGH THE FORECAST
PERIOD...EXCEPT FOR KHYR AND KBRD. BETWEEN 07Z AND 10Z THE LATEST
GUIDANCE SHOWS DEW POINT DEPRESSIONS BETWEEN 4 TO 6 DEGREES F
ALONG WITH LIGHT WINDS AT KBRD AND KHYR. DURING THIS TIME FRAME
MVFR VIS IS POSSIBLE AS FOG MAY DEVELOP.
A COLD FRONT IS CURRENTLY LOCATED ALONG THE INTERNATIONAL BORDER.
THE FRONT WILL MOVE FROM NORTH TO SOUTH FOR THE REST OF TONIGHT
AND ON THURSDAY. THIS WILL SHIFT WINDS FROM A WESTERLY DIRECTION
TO A NORTHERLY DIRECTION BETWEEN 14Z AND 18Z AT ALL TERMINALS.
HOWEVER THE LAST FEW RAP RUNS AND LATEST NAM/GFS SHOW WINDS AT
KDLH SHIFT TO A NORTHEASTERLY DIRECTION AROUND 14Z BEFORE
BECOMING NORTHERLY AT 18Z. GUSTY WINDS WILL DEVELOP IN WAKE OF THE
COLD FRONT PASSAGE ONCE WINDS BECOME NORTHERLY. AFTER 01Z EXPECT
WINDS TO DECOUPLE AS THE NIGHT TIME INVERSION SETS UP.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 65 36 65 47 / 0 0 0 0
INL 64 35 70 48 / 0 0 0 0
BRD 67 40 70 48 / 0 0 0 0
HYR 67 35 69 45 / 0 0 0 0
ASX 63 32 65 46 / 0 0 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...GRANING
LONG TERM...JJM
AVIATION...WL
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
106 AM CDT THU MAY 21 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 349 PM CDT WED MAY 20 2015
AN UPPER LEVEL WAVE WAS MOVING THROUGH THE UPPER MISSISSIPPI RIVER
VALLEY AT 18Z. MEANWHILE...A WEAK COLD FRONT WAS DROPPING SOUTH FROM
CANADA TOWARD THE MN BORDER. CLOUDS HAD DRIFTED INTO THE REGION THIS
AFTERNOON AS A RESULT OF THIS WAVE. THE FRONT WILL MOVE THROUGH NE
MN BY 12Z THURSDAY AND THROUGH NW WI BY 18Z. NO RAIN IS EXPECTED
WITH THIS FRONTAL PASSAGE...JUST A FEW CLOUDS AND A WIND SHIFT TO
THE NORTH OR NORTHWEST. SOME BRIEF GUSTY WINDS OUT OF THE NW MAY
OCCUR WITH FROPA...BUT WILL QUICKLY SUBSIDE. OTHERWISE...HIGH
PRESSURE WILL BUILD OVER THE AREA ON THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 349 PM CDT WED MAY 20 2015
THE FIRST PART OF THE LONG TERM PERIOD LOOKS TO BE FAIRLY QUIET...
WITH BROAD SFC HIGH PRESSURE CENTERED ACROSS THE OHIO RIVER VALLEY
FRIDAY... AND A MID-LAYERED TROUGH LOCATED ACROSS NEW ENGLAND...
CREATING A RIDGE ACROSS THE NORTHERN PLAINS. WITH LIGHT SOUTHERLY
WINDS ACROSS THE NORTHLAND AND LOW LEVEL EASTERLY FLOW OFF THE
LAKE...HIGH RES MODULES ARE INDICATING A POSSIBLE LAKE BREEZE
FORMING FRIDAY AFTERNOON ALONG THE NORTH SHORE. OTHERWISE... THE
MAIN FOCUS FOR THE LONG TERM PERIOD WILL BE A COLORADO LOW
APPROACHING THE NORTHLAND THIS WEEKEND. THERE REMAINS A SIGNIFICANT
DIFFERENCE BETWEEN THE ECMWF AND THE GFS/NAM/GEM REGARDING THE
IMPACTS OF THE LOW... WITH ECMWF COMING IN MOSTLY DRY SATURDAY
AFTERNOON... GFS COMING IN WITH NEARLY 0.5 INCHES OF RAIN IN CENTRAL
MINNESOTA... AND THE OTHER MODELS A BIT LESS. DECIDED TO LEAN AWAY
FROM THE ECMWF AND MORE TOWARDS THE WET SIDE AS IT APPEARS TO BE AN
OUTLIER. EXPECTING THE WARM FRONT TO MOVE NORTHWARD AND STALL ACROSS
OUR SOUTHERN CWA...JUST SOUTH OF DULUTH... SATURDAY EVENING AND
SUNDAY... WHERE THERE COULD BE ENOUGH MU CAPE TO PRODUCE THUNDERSTORM
ACTIVITY. FARTHER SOUTH OF THE STALLED FRONT WILL LIKELY SEE
SCATTERED SHOWERS. THE WET PATTERN... WITH OCCASIONAL CHANCES OF
THUNDERSTORMS...WILL CONTINUE INTO EARLY NEXT WEEK AS MOISTURE
INCREASES OUT OF THE SOUTH. WHILE IT IS STILL FAR OUT... THE GFS IS
INDICATING ENHANCED INSTABILITY AROUND WEDNESDAY OF NEXT WEEK FOR
STRONG THUNDERSTORMS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 105 AM CDT THU MAY 21 2015
VFR CONDITIONS EXPECTED AT ALL TERMINALS THROUGH THE FORECAST
PERIOD...EXCEPT FOR KHYR AND KBRD. BETWEEN 07Z AND 10Z THE LATEST
GUIDANCE SHOWS DEW POINT DEPRESSIONS BETWEEN 4 TO 6 DEGREES F
ALONG WITH LIGHT WINDS AT KBRD AND KHYR. DURING THIS TIME FRAME
MVFR VIS IS POSSIBLE AS FOG MAY DEVELOP.
A COLD FRONT IS CURRENTLY LOCATED ALONG THE INTERNATIONAL BORDER.
THE FRONT WILL MOVE FROM NORTH TO SOUTH FOR THE REST OF TONIGHT
AND ON THURSDAY. THIS WILL SHIFT WINDS FROM A WESTERLY DIRECTION
TO A NORTHERLY DIRECTION BETWEEN 14Z AND 18Z AT ALL TERMINALS.
HOWEVER THE LAST FEW RAP RUNS AND LATEST NAM/GFS SHOW WINDS AT
KDLH SHIFT TO A NORTHEASTERLY DIRECTION AROUND 14Z BEFORE
BECOMING NORTHERLY AT 18Z. GUSTY WINDS WILL DEVELOP IN WAKE OF THE
COLD FRONT PASSAGE ONCE WINDS BECOME NORTHERLY. AFTER 01Z EXPECT
WINDS TO DECOUPLE AS THE NIGHT TIME INVERSION SETS UP.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 40 65 45 70 / 0 0 0 10
INL 33 70 45 74 / 0 0 0 0
BRD 40 70 47 69 / 0 0 0 30
HYR 35 69 43 71 / 0 0 0 20
ASX 35 65 43 72 / 0 0 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...GSF
LONG TERM...MCLOVIN
AVIATION...WL
AREA FORECAST DISCUSSION
NWS TULSA OK
1137 PM CDT WED MAY 20 2015
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
MVFR TO IFR CONDITIONS TONIGHT WILL GIVE WAY TO VFR CONDITIONS
ON THURSDAY AT ALL AREA TAF SITES.
&&
.PREV DISCUSSION... /ISSUED 925 PM CDT WED MAY 20 2015/
..UPDATE...
DISCUSSION...
CLOUDY AND COOL POST-FRONTAL CONDITIONS ACROSS
THE FORECAST AREA THROUGH TONIGHT. AREA RADARS
ARE SHOWING ISOLATED SHOWERS/THUNDERSTORMS
ACROSS SRN OK...AND HAVE UPPED POPS FOR PARTS
OF SE OK AFTER 06Z AND INTO THURSDAY MORNING
BASED ON LATEST HRRR OUTPUT. ALSO BUMPED UP
CLOUD COVER AS WELL.
STILL EXPECTING SEVERAL ROUNDS OF POTENTIALLY
HEAVY PRECIPITATION OVER THE NEXT SEVERAL
DAYS...THE FIRST COMING ON FRIDAY. CONTEMPLATED
ISSUING A FLASH FLOOD WATCH...BUT WILL DEFER
TO THE NEXT SHIFT FOR NOW.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...10
AREA FORECAST DISCUSSION
NWS PORTLAND
244 AM PDT THU MAY 21 2015
.SYNOPSIS...A BROAD UPPER LEVEL TROUGH OVER THE EASTERN PACIFIC AND
ALONG THE WEST COAST WITH LIGHT EASTERLY FLOW ALOFT WILL CONTINUE TO
BRING A THREAT OF SHOWERS AND THUNDERSTORMS TO THE CASCADES THURSDAY
AFTERNOON AND EVENING. ONSHORE FLOW WILL KEEP THE COAST CLOUDY AND
COOL...WITH LOW CLOUDS SPREADING INTO THE VALLEYS IN THE NIGHTS AND
MORNINGS. THE ONSHORE FLOW IS FORECAST TO INCREASE LATE THURSDAY AND
ESPECIALLY THURSDAY NIGHT AND FRIDAY AS ANOTHER SYSTEM DROPS IN FROM
THE NORTHWEST...PUSHING ANY THUNDER EAST OF THE CASCADES ON FRIDAY.
THE STRONGER ONSHORE FLOW WILL CONTINUE THROUGH THE WEEKEND WITH SOME
THREAT OF SHOWERS. ANOTHER UPPER LOW LOOKS LIKE IT WILL APPROACH THE
AREA EARLY NEXT WEEK...BRINGING CONTINUED SHOWER CHANCES.
&&
.SHORT TERM...CONVECTION HAS ONE LAST HURRAH THIS EVENING WITH A
STORM STRENGTHENING IN THE NEWPORT AREA AND PRODUCING A FEW LIGHTNING
STRIKES AND SOME FAIRLY HEAVY RAIN. SMALL ISOLATED SHOWERS REMAIN
TONIGHT...GENERALLY SOUTH OF SALEM AND TILLAMOOK AND THE HRRR SHOWS
THE TREND WILL LIKELY CONTINUE THROUGH THE EARLY MORNING HOURS. ADDED
PATCHY FOG FOR TONIGHT AND INTO EARLY THURSDAY MORNING ALONG THE
COAST AND IN THE SOUTH VALLEY WHERE SHOWERS COVERAGE WAS HIGHEST
WEDNESDAY. DO NOT EXPECT ANY SIGNIFICANTLY DETERIORATED VISIBILITY
WITH FOG TONIGHT AND INTO THURSDAY THOUGH.
MARINE CLOUDS CONTINUE TO HUG THE COAST...WITH CEILINGS
LOWER THAN LAST NIGHT LIKELY DUE TO A WEAKENING OF THE ONSHORE FLOW
INLAND TODAY. THE MODELS STILL SAY THE LOW CLOUDS SHOULD PUSH INLAND
LATER TONIGHT AND THURSDAY MORNING AND IT LOOKS LIKE THEY ARE
STARTING TO DO SO WITH LOW CLOUDS BEING REPORTED AT KELSO. AS
IMPULSES ROTATE AROUND THE LARGE SCALE WEST COAST LOW...THE MODELS
SAY THE ONSHORE FLOW WILL INCREASE THURSDAY AFTERNOON...AND IF THIS
HAPPENS IT IS POSSIBLE THE LOW CLOUDS WILL HAVE TROUBLE BREAKING UP
THURSDAY AFTERNOON. THIS MAY AGAIN KEEP THE BEST CHANCE OF THUNDER UP
IN THE CASCADES THURSDAY AFTERNOON AND EVENING.
THE MODELS SHOW ANOTHER SYSTEM DROPPING DOWN AND APPROACHING THE
SOUTH WASHINGTON AND NORTH OREGON COASTS FROM OFF THE B.C. COAST ON
FRIDAY. THIS REINFORCES THE ONSHORE FLOW IN SOUTHWEST WASHINGTON AND
NORTHWEST OREGON ON FRIDAY...AND MAY MAKE IT DIFFICULT FOR THE LOW
CLOUDS TO CLEAR AGAIN IN THE AFTERNOON. IN ADDITION...THE WINDS AT
ALL LEVELS ARE TURNING MORE WEST TO NORTHWESTERLY...AND THIS SHOULD
PUSH MOST OF THE THUNDERSTORMS EAST OF THE CASCADE CREST FRIDAY
AFTERNOON AND EVENING. IF ANY DO FORM...IT WILL BE BRIEFLY RIGHT AT
THE CREST AND THEN THEY WILL MOVE OFF INTO CENTRAL OREGON...BUT HAVE
LEFT THUNDER OUT OF THE FORECAST AT THIS TIME.
ON FRIDAY NIGHT AND SATURDAY...THE SYSTEM APPROACHING FROM THE
NORTHWEST MOVES ACROSS OUR AREA. THIS SHOULD MAINTAIN SUBSTANTIAL
ONSHORE FLOW. THE BIGGEST QUESTION IS WHETHER THE COLD POOL
ASSOCIATED WITH THE LOW WILL MOVE OVERHEAD...WHICH COULD TRIGGER SOME
SHOWERS OR EVEN SOME THUNDERSTORMS. THE MODELS HAVE SHOWN A VARIETY
OF SOLUTIONS. THE GFS HAS SUGGESTED AT TIMES THAT THE ABOVE SCENARIO
IS POSSIBLE. THE ECMWF AND CANADIAN MODELS HAVE BEEN SHEARING A LEAD
SHORT WAVE SOUTH ALONG THE COAST SATURDAY...WAITING UNTIL SUNDAY FOR
A TRAILING LOW TO COME OVERHEAD. WILL CONTINUE THE BROAD BRUSHED
CHANCE OF SHOWERS FOR NOW WITH MEDIOCRE CONFIDENCE IN ANY DETAILS AT
BEST. BOWEN/TOLLESON
.LONG TERM...NO SIGNIFICANT CHANGES. PREVIOUS DISCUSSION FOLLOWS...
SATURDAY NIGHT THROUGH WEDNESDAY...MODELS HAVE AGAIN COME INTO
REASONABLE AGREEMENT THAT AN UPPER LOW WILL SLIDE ACROSS THE PACIFIC
NORTHWEST LATE SATURDAY INTO SUNDAY...THOUGH STILL PLENTY OF SPREAD
AMONG MODEL GUIDANCE AS TO IF THE LOW TRACKS MORE EASTWARD ACROSS THE
CASCADES OR MORE SOUTHWARD TOWARDS THE GREAT BASIN.
REGARDLESS...INTRODUCED SLIGHT CHANCE POPS FOR MOST OF THE AREA
SUNDAY. MAY END UP SEEING SOME THUNDERSTORMS NEAR THE CASCADE CREST
IF THE UPPER LOW TRACKS OVERHEAD AND LINGERS. FLOW ALOFT LOOKS TO
REMAIN RATHER WEAK OR WEAKLY ONSHORE WITH CONTINUED POSSIBILITIES FOR
SHOWERS IN THE CASCADES. TEMPERATURES WILL REMAIN NEAR SEASONAL FOR
THE FIRST HALF OF NEXT WEEK. CULLEN
&&
.AVIATION...DESPITE THE FEW SHOWERS STILL MOVING W ACROSS NW OREGON
EARLY THU MORNING...CONDITIONS WERE GENERALLY VFR OVER INLAND
AREAS...WITH JUST A FEW PATCHES OF AN MVFR CIG SHOWING UP
OCCASIONALLY. A WEAK ONSHORE FLOW WAS KEEPING THE COAST SOCKED IN
WITH IFR CIGS. EXPECT SOME MVFR CIGS TO SPREAD LOCALLY INLAND THIS
MORNING BETWEEN 11Z AND 15Z...MOST LIKELY IN THE N VALLEY AT THE
KPDX AND KTTD TAF SITES. THERE IS ABOUT A 30 PERCENT CHANCE FOR MVFR
CIGS TO FORM ELSEWHERE. THE INLAND CIGS SHOULD GIVE WAY TO VFR
CONDITIONS AGAIN INLAND AREAS BETWEEN 18Z AND 20Z. ALONG THE COAST
CIGS ARE EXPECTED TO LIFT A FEW HUNDRED FEET DURING THE MORNING
BEFORE BREAKING UP BETWEEN 18Z AND 21Z. VFR CONDITIONS ARE LIKELY TO
BE SHORT LIVED ALONG THE COAST THOUGH...WITH IFR CIGS REFORMING AT
THE END OF THE DAY AFTER 01Z.
KPDX AND APPROACHES...VFR CONDITIONS ARE LIKELY TO GIVE WAY TO AN
MVFR CLOUD DECK SPREADING UP THE COLUMBIA RIVER BETWEEN 11Z AND 15Z.
AFTER A FEW HOURS OF MVFR CIGS...EXPECT VFR CONDITIONS TO REDEVELOP
AFTER 18Z TO 20Z...AND THEN TO PERSIST PAST 10Z TONIGHT.
&&
.MARINE...A RATHER PERSISTENT WEATHER PATTERN WITH HIGH PRES
CENTERED ABOUT 600 NM OFFSHORE WILL CONTINUE THROUGH THE REST OF THE
WEEK AND THE WEEKEND. THIS WILL KEEP WINDS OUT OF THE NW BUT
GENERALLY BELOW 20 KT. A FRESH SWELL OF 5 TO 6 FT WILL ALSO
CONTINUE OUT OF THE WNW.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.
&&
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
538 AM EDT THU MAY 21 2015
.SYNOPSIS...
A SEASONABLY COOL WEATHER PATTERN WILL CONTINUE THROUGH THE END OF
THE WEEK WITH A RATHER CHILLY START TO THE WEEKEND. A GRADUAL
WARMING TREND IS FORECAST THROUGH THE EARLY TO MIDDLE PART OF NEXT
WEEK ALONG WITH AN INCREASING RISK FOR SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
EARLY AM WV LOOP SHOWS A WELL DEFINED MID LVL SHORTWAVE TRACKING
EASTWARD ACROSS S ONTARIO. LOW TO MID LVL THETA-E ADVECTION AHEAD
OF THE WAVE ALONG WITH MODEST HEIGHT FALLS AND PERHAPS SOME RIGHT
ENTRANCE REGION JET DYNAMICS ARE COMBINING TO PRODUCE SOME
SPOTTY/VERY LIGHT RAIN ACROSS EASTERN OHIO/WESTERN PA AS OF 0830Z.
UPSTREAM SFC REPORTS INDICATING ONLY A FEW HUNDREDTHS OF AN INCH
RAIN FROM THIS FEATURE OVR OHIO AND SUSPECT EVEN LESS OVR MOST OF
CENTRAL PA...WHERE DRY AIR IN THE LOW LVLS IS CURRENTLY
RESULTING IN VIRGA. WEAKENING SHORTWAVE WILL PASS NORTH OF PA
LATER THIS MORNING...CAUSING DWINDLING AREA OF -SHRA TO PRESS
EAST. LATEST 4KM NAM/HRRR INDICATE ONLY A SLIGHT CHC OF LINGERING
-SHRA BY NOON ACROSS THE SE COUNTIES.
A SECOND SHORTWAVE...DIVING INTO THE UPPER MIDWEST THIS AM...WILL
PUSH INTO WESTERN PA BY THIS EVENING. INCREASING LG SCALE FORCING
AHEAD OF THIS FEATURE WILL LIKELY PRODUCE ANOTHER ROUND OF SCT
-SHRA THIS EVENING. ALL NR TERM MDL INDICATE THE BEST CHC OF
MEASURABLE RAIN WILL BE ACROSS THE CENTRAL MTNS THIS
EVENING...ALONG PLUME OF SLIGHTLY HIGHER PWATS.
OVERCAST SKIES...COMBINED WITH AN ALREADY CHILLY AIR MASS OVR THE
AREA...WILL RESULT IN AN UNSEASONABLY COOL DAY WITH AFTERNOON
HIGHS 10 TO 20 DEGREES BELOW LATE MAY CLIMO...RANGING FROM 55-60F
OVER MOST OF CENTRAL PA.
TRENDED POPS DOWNWARD FROM NW TO SE EARLY TONIGHT AS DRIER AIR
ARRIVES IN WAKE OF PASSING SHORTWAVE. SFC LOW PASSING OFF THE MID
ATL COAST STRENGTHENS A BIT...WHICH SHOULD LEAD TO A SLIGHT
UPTICK IN NW WINDS INTO FRIDAY MORNING. LOWS SHOULD AVG IN THE
L-M40S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
THE MAIN LARGE SCALE UPPER TROUGH AXIS IS PROGGED TO ROTATE
THROUGH THE ERN GREAT LAKES AND NRN NEW ENGLAND ON DAY 2 WHICH
SHOULD DRIVE A RE-ENFORCING SFC COLD FRONT THROUGH CENTRAL PA.
MODEL CONSENSUS CONTINUES TO SUGGEST ISOLD/WDLY SCT SHOWERS WITH
THE FRONTAL PASSAGE BUT WITH VERY LIMITED MSTR KEPT POPS AOB 20
PCT. DAY 2 MAX TEMPS SHOULD MODERATE SOME BUT STILL AVG BELOW
NORMAL FOR THIS TIME OF YEAR.
BEHIND THE COLD FRONT...A SPRAWLING AREA OF HIGH PRESSURE WILL
BUILD INTO THE REGION FRI NIGHT/A.M. SATURDAY. CONFIDENCE
CONTINUES TO INCREASE FOR AREAS OF FROST ALONG THE ALLEGHENY
FRONT BY SATURDAY MORNING. COULD EVEN SEE SOME FROST IN THE
OUTLYING AREAS AROUND STATE COLLEGE. WITH A FAVORABLE PATTERN AND
SUPPORT FROM MODEL CONSENSUS...COLLABORATED WITH BUF/BGM ON A
FREEZE WATCH FOR THE NRN MTNS WITH FCST MINS IN THE 28-32F RANGE.
WILL ALSO CONTINUE TO HIGHLIGHT FROST RISK IN THE HWO AND LATER
SHIFTS CAN ADD FROST HEADLINES AS NEEDED.
AFTER A RATHER CHILLY START TO THE WEEKEND...TEMPS SHOULD REBOUND
NICELY ON SATURDAY WITH HIGHS GENERALLY FROM 65-70F. HIGH PRESSURE
SLIDES OFF THE MID ATLC COAST SATURDAY NIGHT WITH A WARMER RETURN
FLOW SETTING UP INTO SUNDAY.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ALL GUIDANCE CONTINUES TO SIGNAL A WARMING TREND INTO THE MIDDLE
OF NEXT WEEK...WITH HIGH CONFIDENCE IN ABOVE NORMAL TEMPERATURES
BY MEMORIAL DAY AS ANOMALOUS 500MB RIDGE BUILDS OVER THE EASTERN
U.S. GFS/ECMWF DISAGREE ON PLACEMENT OF WARM FRONTAL ZONE LIFTING
NWD FROM THE SRN PLAINS/LWR MS VLY. THIS WILL LKLY IMPACT PCPN
RISK EARLY NEXT WEEK. A COLD FRONT IS PROGGED TO APPROACH THE AREA
LATER IN THE WEEK. WITH LOW CONFIDENCE IN BOUNDARY PLACEMENT AT
THIS RANGE...WILL MAINTAIN DAILY RISK OF MAINLY AFTERNOON
THUNDERSTORMS GIVEN INCREASINGLY HUMID/MUGGY SUMMER-LIKE PATTERN.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
A WEAK AREA OF LOW PRESSURE WILL TRACK SOUTH OF PENNSYLVANIA EARLY
THIS MORNING...BRINGING A FEW -SHRA TO THE CENTRAL AND SOUTHERN
PART OF THE STATE. HOWEVER...DRY AIR AT LOW LEVELS SHOULD ENSURE
VFR CONDS LAST THRU DAWN. THE -SHRA SHOULD PASS EAST OF THE AREA
BY LATE MORNING. HOWEVER...A MOISTENING SERLY FLOW ASCENDING THE
HIGHER TERRAIN OF SOUTH CENTRAL PA IS LIKELY TO PRODUCE MVFR CIGS
AT KJST/KAOO...AND POSSIBLY KUNV...DURING MUCH OF THE DAYLIGHT
HOURS. HRRR EVEN IMPLIES THE CHC OF IFR CIGS AT KJST THIS AFTN.
HOWEVER...ODDS OF THIS STILL LESS THAN 50 PCT. IMPROVING FLYING
CONDS EXPECTED THIS EVENING...AS WINDS SHIFT TO THE NW...DRAWING
DRIER AIR AND CLEARING SKIES INTO THE REGION.
OUTLOOK...
FRI-SUN...NO SIG WX EXPECTED.
MON...MAINLY VFR...MVFR POSS IN SHRA/TSRA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY MORNING
FOR PAZ004>006-010-011-037.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...FITZGERALD/STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...STEINBUGL
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1149 PM CDT Wed May 20 2015
.AVIATION...
/06Z TAFS/
Look for IFR to MVFR conditions to continue for the next 24 hours.
Models this cycle present little chance for improvement during the
next 24 hours, as winter-like stratus remains firmly in place
across West Central Texas. Showers and perhaps a few thunderstorms
will develop, as warm air glides up and over the unseasonably cool
air near the surface.
&&
.PREV DISCUSSION... /ISSUED 1056 PM CDT Wed May 20 2015/
UPDATE...
The threat of severe thunderstorms has diminished across West
Central Texas. Most thunderstorms have moved south of our
counties. The old remaining thunderstorm cluster is over our
Northwest Hill Country counties, and the threat there has evolved
into more of a heavy rain threat, with the potential for local
flash flooding. Thus, we have canceled Severe Thunderstorm Watch
192 for all counties.
PREV DISCUSSION... /ISSUED 627 PM CDT Wed May 20 2015/
AVIATION...
/00Z TAFS/
Look for very challenging flight weather to continue for the next
24 hours. A cold front continue to move slowly south toward our
Interstate 10 corridor. North of the front low -winter-like stratus
has covered much of West Central Texas. Expect some improvement
tomorrow afternoon. Otherwise, plan for IFR to MVFR ceilings to
dominate.
PREV DISCUSSION... /ISSUED 552 PM CDT Wed May 20 2015/
UPDATE...
Thunderstorms, some severe, will continue to develop along or near
the cold front this evening. The cold front now extends near a
line from Barnhart...to Eldorado...to Brady. After coordination
with the Storm Prediction Central...we have issued Severe
Thunderstorm Watch number 192, which is valid until midnight CDT
tonight, for counties along and south of a line from Mertzon to
Brady. The latest Zone package headlines this watch for the
appropriate counties.
PREV DISCUSSION... /ISSUED 350 PM CDT Wed May 20 2015/
SHORT TERM...
(Tonight and Thursday)
A rather strong cold front has moved south of a San Angelo to
Coleman line this afternoon, dropping temperatures into the upper
50s and lower 60s across the Big Country. Low clouds and cold
advection north of the front has greatly reduced instability,
limiting the potential for diurnal convection. Ahead of the front,
temperatures have warmed into the lower 80s with dewpoints hanging
in the mid/upper 60s. Modified RAP soundings indicate SBCAPE values
on the order of 2000-2500 J/kg in the warm sector with effective
shear values exceeding 35 kts. This will support organized
convection this afternoon and during the evening hours, with the
primary focus along and south of the front. The primary concern is
for large hail and damaging winds. However, a tornadic storm cannot
be ruled out in the vicinity of this boundary.
Right moving supercell vectors are from the west and northwest at 10
to 15 mph. This slow storm motion and the presence of the
aforementioned cold front will support the potential for locally
heavy rainfall along the I-10 corridor tonight. Additional storms
will be possible overnight as isentropic ascent develops over the
frontal zone. As the front moves south overnight and early Thursday,
rain chances are expected to diminish during the morning hours.
However, shortwave ridging aloft will be shifting to the east as a
strong shortwave trough moves across the southern Rockies.
Increasing large scale ascent will promote the development of
scattered showers and thunderstorms during the afternoon hours.
Fortunately, the severe weather potential is expected to remain low
on Thursday. Much cooler temperatures are anticipated tomorrow, with
highs in the 60s across most of the area.
Johnson
LONG TERM...
(Thursday night through next Wednesday)
The main focus is with the severe weather and heavy rainfall
possibility for the Memorial Day holiday weekend.
Increased chance and coverage of showers and thunderstorms
is expected across our area Thursday night, with the arrival
of a stronger shortwave in southwest flow aloft. With subsidence
and advection of some drier mid-level air in the wake of this
departing shortwave, will have reduced chances for showers and
thunderstorms on Friday.
An upper low will move northeast into southeastern Utah Friday
night, with an upper trough trailing from the low across the
Desert Southwest. The main chance for showers and thunderstorms
Friday night will be overnight, and across our northwestern
counties, with the possibility of a weak embedded disturbance
out ahead of the main trough lifting northeast into far west
or northwest Texas.
The aforementioned upper trough will move slowly east across
Arizona and New Mexico over the holiday weekend. Given the
forecast strength of this system, will have increased potential
for severe weather with stronger instability and increased
vertical shear. Carrying higher PoPs over the weekend with the
highest rain chance on Saturday night. Heavy rainfall will also
be possible with repeat convective activity and precipitable
water values at or above 1.5 inches across much of our area.
The upper trough is progged to eventually lift northeast across
Texas, but the 12Z GFS and ECMWF differ on the timing.
Following departure of this system, drier and warmer conditions
look to be in store for our area as heights build aloft. May
have another upper trough approach from the southwestern states
next Wednesday, but keeping PoPs below mention with the
uncertainty at this time.
19
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 57 66 58 78 67 / 50 40 60 50 40
San Angelo 60 68 61 81 67 / 60 40 60 30 30
Junction 65 72 65 82 68 / 70 50 50 30 30
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1250 AM MDT THU MAY 21 2015
.UPDATE...
ISSUED AT 913 PM MDT WED MAY 20 2015
NO MAJOR CHANGES FOR THE EVENING UPDATE. MOST OF THE LIGHT SHOWER
ACTIVITY FROM LATE AFTERNOON EARLY EVENING HAS DISSIPATED WITH THE
EXCEPTION OF SOME LIGHT TO MODERATE SHOWERS PERSISTING IN
SOUTHWESTERN CARBON COUNTY WY. AREAS OF DENSE FOG HAVE REDEVELOPED
OVER THE SUMMIT BETWEEN CHEYENNE AND LARAMIE...AND WILL CONTINUE
THE DENSE FOG ADVISORY THROUGH THURSDAY MORNING FOR THAT PART OF
THE SOUTH LARAMIE RANGE.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 243 PM MDT WED MAY 20 2015
SFC ANALYSIS SHOWS THE HIGH PRESSURE CENTER LOCATED NEAR THE PINE
RIDGE WITH EAST TO NORTHEAST UPSLOPE AND PERSISTENT LOW CLOUDS
ACROSS THE REGION. IT HAS BEEN ANOTHER COOL DAY WITH TEMPS A GOOD
20 DEGREES BELOW NORMAL. EXPIRED THE DENSE FOG ADVISORY FOR THE
SOUTH LARAMIE RANGE WITH WYDOT OBS SHOWING MOST VIS ABOVE 1 MILE.
THE HRRR DOES INDICATE VIS DROPPING BELOW ONE HALF MILE OVER THE
SOUTH LARAMIE RANGE BY 03Z. THIS MAKES SENSE WITH SFC WINDS
REMAINING SOUTHEAST TO SOUTH OVERNIGHT. HAVE AREAS OF FOG FROM
BUFORD TO THE SUMMIT BY EARLY TONIGHT AND CONTINUING THROUGH
THURSDAY MORING. WILL LET THE EVENING/NIGHT SHIFT MONITOR THE OBS
AND WEBCAMS OVER THE SUMMIT...AS DENSE FOG IS DEFINITELY POSSIBLE IN
THIS PATTERN. SHOWERS DEVELOPING THIS AFTN ALONG AND WEST OF THE
LARAMIE RANGE HAVE BEEN STRUGGLING TO STAY TOGETHER IN THE VERY
STABLE AIRMASS OVER THE PLAINS. KEPT ISOLATED TO SCATTERED SHOWERS
CONFINED TO MAINLY THE LARAMIE RANGE AND POINTS WEST THROUGH THE
EVENING.
PATTERN DOES NOT CHANGE A WHOLE LOT BY THURSDAY. LOW CLOUDS WILL BE
STUBBORN TO CLEAR YET AGAIN WITH MOIST SOUTHEAST LLVL FLOW.
SLIGHTLY BETTER INSTABILITY WILL EXIST ALONG THE LARAMIE RANGE (CAPE
VALUES OF 100-200 J/KG) BUT THIS IS LARGELY DEPENDENT ON SOME AFTN
CLEARING...WHICH IS QUESTIONABLE. INSTABILITY REALLY DROPS OFF TO
THE EAST OF CHEYENNE SO EXPECTING STORMS TO REMAIN CONFINED IN
VICINITY OF THE LARAMIE RANGE. A SHORTWAVE WILL EJECT NORTHWARD
FROM COLORADO BY LATE THURS NIGHT AND FRI MORNING. WITH GOOD UPPER
LEVEL DIFLUENCE...MODELS HAVE BEEN CONSISTENT AT SHOWING WIDESPREAD
RAIN DEVELOPING OVER THE PLAINS BY FRI MORNING AND CONTINUING
THROUGH MUCH OF THE DAY. THIS IS LOOKING LIKE ANOTHER 0.25-0.75
INCH MAINLY STRATIFORM RAIN EVENT FOR LOCATIONS TO THE EAST OF THE
LARAMIE RANGE. DID LOWER HIGHS A FEW DEGREES ON FRI WITH HIGHS
STRUGGLING TO GET ABOVE THE MID 50S.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 243 PM MDT WED MAY 20 2015
THE MAIN CONCERN WITH THIS PORTION OF THE FORECAST IS THE SEVERE
WEATHER POTENTIAL SATURDAY.
SATURDAY-SATURDAY NIGHT:
LATEST LOOK AT THE GEM/GEFS ENSEMBLES AND ECMWF ARE SHOWING
REALLY GOOD AGREEMENT IN THE TRACK OF THE UPPER LEVEL TROF THIS
WEEKEND. THE MODELS ARE ALSO IN AGREEMENT IN SHOWING THIS CLOSED
UPPER TROF OPENING UP IN NORTHWEST COLORADO AND SENDING ITS FIRST
PIECE OF ENERGY INTO OUR REGION SATURDAY. HOWEVER...THERE IS QUITE
A BIT OF STANDARD DEVIATION IN THE PLACEMENT OF THE SURFACE LOW
AROUND 00Z SUNDAY. THE MEAN ENSEMBLES ARE SHOWING THE SURFACE LOW
DEVELOPING IN EASTERN COLORADO. HOWEVER...THERE IS SOME HINTS THAT
THIS SURFACE LOW MAY ACTUALLY DEVELOP FURTHER NORTH IN NORTHEAST
COLORADO AND LIFT NORTHEAST THROUGH THE NEBRASKA PANHANDLE. IF
THIS SURFACE LOW DEVELOPS FURTHER NORTH...WE MAY SEE WARMER
TEMPERATURES AND HIGHER LOW LEVEL MOISTURE BEING DRAWN INTO AREAS
EAST OF THE LARAMIE WHICH WILL RESULT IN HIGHER INSTABILITY. THIS
COULD SET THE STAGE FOR SEVERE WEATHER IN AREAS EAST OF THE
LARAMIE RANGE SATURDAY AFTN/EVE...ESPECIALLY WITH 0-6KM SHEAR
VALUES APPROACHING 40 TO 50 KTS. ANOTHER CONCERN IS WHETHER OR NOT
WE WILL SEE LOW CLOUDS. AT THIS POINT...IT DOES NOT APPEAR THAT
THE LOW CLOUDS WILL BE PRESENT...BUT WE WILL HAVE TO SEE HOW THAT
EVOLVES. IF THE LOW CLOUDS ARE NOT PRESENT...TEMPERATURES SHOULD
BE ABLE TO CLIMB TO THE 60S.
SUNDAY-SUNDAY NIGHT:
THE MODELS ARE SHOWING THE MAIN UPPER LEVEL TROF MOVING INTO THE
AREA ON SUNDAY IN ITS WEAKENED STATE. THERE IS A LITTLE MORE
UNCERTAINTY ON HOW THIS TROF WILL IMPACT THE AREA ON SUNDAY
AFTERNOON INTO SUNDAY EVENING. AT THIS POINT...IT APPEARS LIKE THE
MAIN CONVECTION SHOW WILL BE ON SATURDAY AFTERNOON/EVENING.
HOWEVER...IF WE DO NOT SEE MANY STORMS DURING THAT TIME...THEN
SUNDAY MAY BE A DAY TO WATCH AS WELL. IF WE DO SEE WIDESPREAD
CONVECTION ON SATURDAY THEN SUNDAY CHANCES MAY BE MUCH SMALLER.
FOR NOW...WE WILL STAY WITH THE MODEL BLENDS FOR CONSISTENCY SAKE.
MONDAY-WEDNESDAY:
MODELS/ENSEMBLES ARE IN PRETTY GOOD AGREEMENT IN SHOWING THE UPPER
LEVEL RIDGE BUILDING OVER THE AREA AHEAD OF THE NEXT UPPER LEVEL
TROF MOVING INTO THE NORTHERN ROCKIES. THIS TROF WILL INDUCE UPPER
LEVEL DIFFLUENCE OVER THE AREA ON MONDAY AND TUESDAY WHICH COULD
SPARK SOME CONVECTION OVER THE MOUNTAINS WITH SOME OF THIS
CONVECTION POSSIBLY SPILLING OVER INTO THE PLAINS. OVERALL...IT
DOES NOT LOOK LIKE A REAL WET PATTERN...BUT WE CANNOT RULE OUT THE
AFTERNOON AND EVENING CONVECTION CHANCES OVER OUR AREA EITHER.
ALTHOUGH...TEMPERATURES WILL NOT BE TOO COOL WITH HIGHS CLIMBING
TO NEAR NORMAL READING WITH HIGHS MAINLY IN THE 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1246 AM MDT THU MAY 21 2015
WYOMING TAFS...MOUNTAINS MOSTLY OBSCURED. IFR PREVAILS IN FOG
AND LOW CLOUDS THROUGH MID MORNING...THEN VFR WITH CEILINGS AROUND
4000 FEET AGL. IN THE LATE AFTERNOON AND EARLY EVENING...ISOLATED
TO SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS PRODUCING
VISIBILITIES 4 TO 6 MILES WITH OCCASIONAL MVFR CEILINGS.
NEBRASKA TAFS...VFR AND OCCASIONAL MVFR PREVAIL THROUGH THE
PRE DAWN HOURS...EXCEPT AT SIDNEY WHERE IFR IN FOG AND LOW CLOUDS
PREVAILS FROM 10Z TO 15Z. AFTER MID MORNING...VFR PREVAILS WITH
CEILINGS FROM 3000 TO 5000 FEET AGL...THEN MVFR DEVELOPS AGAIN
AT SIDNEY THURSDAY EVENING.
&&
.FIRE WEATHER...
ISSUED AT 243 PM MDT WED MAY 20 2015
NO FIRE WEATHER CONCERNS THROUGH THE WEEKEND. TEMPERATURES WILL
REMAIN BELOW NORMAL AND AFTERNOON HUMIDITY VALUES WILL BE ABOVE 50
PERCENT. THE BEST CHANCE OF WIDESPREAD WETTING RAIN WILL COME
THURSDAY NIGHT AND FRIDAY.
&&
.HYDROLOGY...
ISSUED AT 243 PM MDT WED MAY 20 2015
LARAMIE RIVER AT FORT LARAMIE AND LARAMIE WILL CONTINUE TO RUN AT
RELATIVELY HIGH LEVELS THROUGH THIS WEEK...BUT AT THIS TIME IS
EXPECTED TO REMAIN WITHIN ITS BANKS. ANOTHER ROUND OF MODERATE TO
HEAVY RAINFALL IS EXPECTED OVER THE HIGH PLAINS AND POSSIBLY THE
LARAMIE VALLEY ON FRIDAY...SO WILL NEED TO CONTINUE TO MONITOR
THE LARAMIE RIVER THROUGH LATE THIS WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...DENSE FOG ADVISORY UNTIL 10 AM MDT THIS MORNING FOR WYZ116.
NE...NONE.
&&
$$
UPDATE...JG
SHORT TERM...ZF
LONG TERM...REC
AVIATION...RUBIN
FIRE WEATHER...ZF
HYDROLOGY...ZF
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
639 AM CDT THU MAY 21 2015
.AVIATION...21/12Z TAF CYCLE
MVFR CIGS WL BE WIDESPREAD ACRS THE FA THRU MUCH OF THE MRNG. THE
NRN EDGE OF ONGOING SHRA/TSRA ACTIVITY ACRS SRN AR COULD BRIEFLY
AFFECT THE SRN TAF SITES EARLY IN THE PD...WITH VCSH MENTIONED
ATTM. PRECIP WL CONT TO SHIFT SLOLY SWD AS THE MRNG PROGRESSES.
LOW CLOUDS WL GRADUALLY ERODE HEADING INTO THIS AFTN AS DRIER AIR
CONTS TO FILTER INTO THE AREA...WITH VFR CONDS RETURNING. /44/
&&
.PREV DISCUSSION... /ISSUED 412 AM CDT THU MAY 21 2015/
SHORT TERM...TODAY THROUGH SUNDAY NIGHT
INITIALLY UPDATED POPS ACROSS PORTIONS OF WESTERN AND SOUTHERN
ARKANSAS TO REFLECT CURRENT RADAR TRENDS AS WELL AS TREND TOWARDS
THE HRRR WHICH SHOWS PRECIPITATION CONTINUING FOR MUCH OF THE FIRST
HALF OF THE DAY ACROSS SOUTHERN ARKANSAS. PRECIP SHOULD CONTINUE TO
WEAKEN AND SPREAD TO THE SOUTH AS SLOW MOVING COLD FRONT CONTINUES
TO MOVE SOUTH.
CONTINUED THE TREND OF LOWERING TEMPS AND GOING BELOW GUIDANCE FOR
THURSDAY AND FRIDAY WITH STRONG NORTHERLY FLOW IN PLACE. AT THIS
POINT..TEMPERATURES WILL BE RUNNING TEN TO FIFTEEN DEGREES BELOW
NORMAL IN MOST LOCATIONS ACROSS THE STATE.
HIGH PRESSURE AT THE SURFACE BEGINS TO SHIFT OFF TO THE EAST LATE
FRIDAY ALLOWING A RETURN OF MOIST SOUTHERLY FLOW. SOUTHERLY FLOW
WILL BE DEEP AND MOISTURE WILL INCREASE DRAMATICALLY LATE SATURDAY.
BEGAN TO TREND DEWPOINTS UP AT THIS POINT WITH RAW MODELS SUGGESTING
70 PLUS DEWPOINTS WILL BE IN PLACE ACROSS SW ARKANSAS.
AT THIS POINT THERE STILL REMAINS SOME UNCERTAINTY ON THE SEVERE
WEATHER POTENTIAL. BUT MODEL SOUNDINGS DO SUGGEST SOME STRONGER
THUNDERSTORMS WILL BE POSSIBLE ON SUNDAY ACROSS WESTERN ARKANSAS.
RAINFALL TOTALS WILL GENERALLY BE LIGHT AND LIMITED TO WESTERN
ARKANSAS THROUGH THE FIRST HALF OF THE WEEKEND. RAINFALL CHANCES AND
QPF INCREASE SUNDAY EVENING WITH AN ADDITIONAL ONE TO TWO INCHES
POSSIBLE. WESTERN ARKANSAS HAS BEEN FAIRLY HARD HIT IN THE PAST FEW
WEEKS WITH HEAVY RAIN...AND AN ADDITIONAL ROUND OF HEAVY RAIN WILL
LIKELY BE PROBLEMATIC. THIS IS STILL A FEW DAYS OUT...BUT BEARS
WATCHING IN FUTURE FORECASTS.
LONG TERM...MONDAY THROUGH WEDNESDAY
NO SIG CHGS WERE MADE TO THE CURRENT FCST AS THE LATEST MODEL TRENDS
CONT TO INDC AN UNSETTLED WX PATTERN ACRS THE MID SOUTH. A
PERSISTENT SWLY FLOW ALOFT WL CONT TO BRING SEVERAL UPR LVL IMPULSES
NEWD THRU AR. THESE FEATURES WL INTERACT WITH THE MOIST AIRMASS IN
PLACE TO PRODUCE GOOD CHCS OF SHRA/TSRA. WITH SOILS ALREADY QUITE
SATURATED...ANY ADDITIONAL RAINFALL WL ONLY ENHANCE THE CHCS OF
ADDITIONAL FLOODING OVR MUCH OF THE AREA.
SOME OF THE MODELS DO INDC THAT THE UPR PATTERN WL DE-AMPLIFY OVR
THE SRN STATES HEADING INTO THE MIDDLE OF NEXT WEEK. THIS WL RESULT
IN DRIER CONDS FOR THE FA.
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
848 AM PDT THU MAY 21 2015
.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.
&&
.DISCUSSION...AS OF 08:45 AM PDT THURSDAY...DEEP STRATUS DECK
COVERS MUCH OF THE BAY AREA THIS MORNING...MOSTLY CLOUDY START TO
THE DAY. INTERESTING TO NOTE THE CLOUDS ARE NOT YOUR TYPICAL
MARINE LAYER...SODARS AND PROFILERS DO NOT INDICATE A DEFINED
MARINE LAYER. THE KOAK SOUNDING ON THE OTHER HAND DOES SHOW A
MOIST LOWER 5K FEET. SYNOPTICALLY SPEAKING...A WEAK UPPER LEVEL
DISTURBANCE IS CURRENTLY SITTING OFF THE SF BAY COAST. THE
ASSOCIATED LIFT AND MOIST LOWER 5K FT HELPED TO PRODUCE SOME LIGHT
SHOWERS OVERNIGHT WITH SEVERAL STATIONS MEASURING UP TO A TENTH.
FOR THE REST OF TODAY...ANOTHER STRONGER UPPER LOW IS FORECAST TO
DROP SOUTHWARD THROUGH THE BASE OF A BROAD UPPER TROUGH. THE
UPPER LOW CAN BE SEEN ON THE WATER VAPOR NEAR 130W. LATEST SHORT
TERM MODELS...THE HRRR AND RAP BOTH INDICATE INCREASED SHOWER
ACTIVITY THIS AFTERNOON AS THE UPPER LOW DEEPENS OFF THE COAST.
THE BEST CHANCE FOR SHOWERS WILL BE OVER TERRAIN FAVORED
LOCATIONS. IN FACT...THE LATEST NAM/HRRR INDICATE A LITTLE BIT OF
SFC INSTABILITY OVER THE E BAY HILLS AND THE GABILAN RANGE THIS
AFTERNOON. THEREFORE COULD NOT TOTALLY RULE OUT SOME THUNDER AS WELL.
GIVEN THE UNCERTAINTY OF ACTUAL LOCATIONS FOR SHOWER
ACTIVITY...LATEST FORECAST HAS BLANKET COVERAGE OF SHOWERS THIS
AFTERNOON. NO MAJOR UPDATE IS NEEDED AT THIS TIME...BUT WILL LIKE
TWEAK THE WEATHER GRIDS TO BETTER REFLECT REALITY THIS AFTERNOON.
&&
.PREV DISCUSSION...AS OF 3:58 AM PDT THURSDAY...THE TROUGH AND
UPPER LOW WILL MOVE SOUTH AND EAST OF THE AREA BY LATE FRIDAY WITH
HIGH PRESSURE BUILDING INLAND DURING THE WEEKEND FROM THE EASTERN
PACIFIC. THIS WILL USHER IN A SHORT-LIVED WARMING TREND FOR
SATURDAY AND SUNDAY. BY EARLY NEXT WEEK...THOUGH..ANOTHER TROUGH
WILL SET UP ALONG THE COAST FOR A RETURN TO BELOW-NORMAL
TEMPERATURES.
&&
.AVIATION...AS OF 4:57 AM PDT THURSDAY...A PERSISTENT AREA OF LOW
PRESSURE POSITIONED OVER THE WEST COAST WILL MAINTAIN CLOUD COVER
OVER THE TERMINALS TODAY. HOWEVER...A SMALLER SCALE LOW PRESSURE
SYSTEM WORKING ITS WAY TOWARDS THE CENTRAL CALIFORNIA COAST WILL
LIFT THE CLOUD DECK A BIT LATER THIS MORNING INTO THE AFTERNOON
HOURS PROVIDING THE AREA WITH A POSSIBILITY OF SHOWERS.
VICINITY OF KSFO...MVFR CIGS BKN-OVC030 ARE EXPECTED TO IMPROVE TO
VFR BKN-OVC035-050 LATER THIS MORNING INTO THE AFTERNOON HOURS. A
PERIOD OF BKN015 WILL BE POSSIBLE DURING THE EARLY MORNING HOURS. A
SLIGHT CHANCE OF SHOWERS IS ALSO IN THE GENERAL AREA FORECAST.
WESTERLY WINDS WILL REACH 15 KT THIS AFTERNOON.
CONFIDENCE IS MODERATE.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...MVFR CIGS BKN-OVC030 ARE EXPECTED
TO PREVAIL TODAY WITH A PERIOD OF BKN012 POSSIBLE EARLY THIS
MORNING. A SLIGHT CHANCE OF SHOWERS IS IN THE GENERAL AREA
FORECAST FOR THE LATE MORNING AFTERNOON HOURS. WESTERLY WINDS WILL
REACH 10 KT THIS AFTERNOON WITH STRONGER GUSTS IN THE SALINAS
VALLEY.
CONFIDENCE IS MODERATE.
&&
.MARINE...AS OF 02:23 AM PDT THURSDAY...A STORM SYSTEM WILL SLIDE
SOUTH ALONG THE COAST TODAY PROMOTING A POSSIBILITY OF SHOWERS
ACROSS THE COASTAL WATERS. GENERALLY LIGHT WINDS AND GENTLE SEAS
ARE EXPECTED THROUGH FRIDAY AS THE STORM PASSES. NORTHERLY WINDS
WILL INCREASE BEHIND THE DEPARTING STORM SYSTEM FRIDAY EVENING AS
THE SURFACE PRESSURE GRADIENT STRENGTHENS. THE INCREASING WINDS
WILL RESULT IN DETERIORATING SEA CONDITIONS.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 1 PM
&&
$$
PUBLIC FORECAST: MM
AVIATION/MARINE: LARRY
VISIT US AT WEATHER.GOV/SANFRANCISCO
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AREA FORECAST DISCUSSION
NWS NEW YORK NY
746 AM EDT THU MAY 21 2015
.SYNOPSIS...
WEAK HIGH PRESSURE QUICKLY MOVES EAST TODAY...GIVING WAY TO LOW
PRESSURE THAT PASSES TO THE SOUTH AND EAST TONIGHT. A COLD FRONT
MOVES THROUGH LATE FRIDAY. HIGH PRESSURE BUILDS ACROSS THE AREA
ON SATURDAY...THEN MOVES OFFSHORE EARLY SUNDAY. A WARM FRONT WILL
THEN SLOWLY APPROACH FROM THE SOUTHWEST LATE SUNDAY THROUGH
TUESDAY. THE FRONT MAY LIFT TO THE NORTH WEDNESDAY MORNING...AND
BE FOLLOWED BY A COLD FRONT LATER WEDNESDAY INTO THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FORECAST SEEMS ON TRACK. MADE MINOR ADJUSTMENTS TO TEMPERATURE AND
DEWPOINT TO REFLECT LATEST SURFACE OBSERVATIONS. OTHERWISE...PLENTY
OF MID AND HIGH LEVEL CLOUDS THIS MORNING OUT AHEAD OF UPSTREAM
SHORTWAVE WILL LOWER AND THICKEN AS THE DAY PROGRESSES.
THERE COULD BE A FEW PEEKS OF SUN EARLY...BUT MAINLY CLOUDY
CONDITIONS ARE ANTICIPATED.
AT THE SFC...LOW PRESSURE OVER THE APPALACHIANS TO OUR SOUTH WILL
MOVE TOWARD THE MID ATLANTIC COAST LATE TODAY AHEAD OF THE
SHORTWAVE.
SOUTHWEST ZONES...THEN COASTAL ZONES FROM NYC EAST COULD SEE LIGHT
RAIN MOVE IN THIS AFTERNOON. LATEST HRRR SIMULATED
REFLECTIVITY...ALONG WITH HIGH RES ARW/NMM...DOES FORECAST RAIN TO
APPROACH THE AREA...AND CLIP THE SW ZONES THIS AFTERNOON. WILL
MAINTAIN CHANCE POPS DURING THE AFTERNOON...WITH A GENERAL
LOWERING OF POPS AS YOU HEAD NORTHWARD.
WITH PLENTY OF CLOUD COVER IN PLACE...TEMPS WILL STRUGGLE THROUGH
THE 50S...AND INTO THE LOWER 60S. THIS IS BELOW NORMAL BY 5 TO 10
DEGREES...AND IS SUPPORTED BY LATEST MOS NUMBERS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
LARGE UPPER TROUGH/LOW PRESSURE OVER EASTERN CANADA...WITH
SHORTWAVE ENERGY PIN-WHEELING AROUND THE CLOSED LOW...WILL PREVAIL
THIS TIME FRAME.
STRENGTHENING SHORTWAVE ROUNDING THE BASE OF THE LARGE UPPER TROUGH
QUICKLY TRAVERSES FROM WEST TO EAST TONIGHT...PASSING TO THE EAST OF
THE AREA EARLY FRIDAY MORNING. IN RESPONSE...SFC LOW OFF THE MID
ATLANTIC COAST IS EXPECTED TO DEEPEN SLIGHTLY...LOWERING A FEW
MILLIBARS...AS IT TRACKS SOMEWHERE JUST SOUTH AND EAST OF THE
40N/70W BENCHMARK TONIGHT INTO EARLY FRIDAY. IN FACT...CONSENSUS IS
OBSERVED IN LATEST NAM/GFS/SREF MEAN AND ECMWF WITH HANDLING OF THIS
LOW.
PRECIP SHIELD EXTENDS NORTH AND WEST OF THIS SFC LOW...AND EXPANDS
AHEAD OF THE AFOREMENTIONED SHORTWAVE.
AS FOR POPS...WILL CONTINUE TO CARRY HIGH CHANCE TO LIKELY POPS NEAR
THE COAST. THIS BASED ON ANALYSIS OF GFS AND NAM STATISTICAL
MOS...NCEP MODEL PLAN FIELDS...AND SREF PLUMES. IN GENERAL...COASTAL
LOCALES TONIGHT COULD OBSERVE ANYWHERE FROM AROUND A TENTH OF AN
INCH ON AVERAGE. ACROSS NORTHERN ZONES SUCH AS THE LOWER HUDSON
VALLEY AND SW CT...POPS REMAIN LOWER AND QPF WOULD RANGE FROM A
TRACE TO MAYBE A TENTH OF AN INCH.
ANY RAIN DEPARTS EARLY FRIDAY...WITH DRY WEATHER EXPECTED THROUGH
THE MORNING. CLOUDS GIVE WAY TO BRIEF SUNSHINE. BY AFTERNOON...A
COLD FRONT AHEAD OF DIGGING TROUGH APPROACHES LATE. CLOUDS INCREASE
AGAIN...AND A FEW SHOWERS ARE POSSIBLE. NAM MOST AGGRESSIVE IN
DEVELOPING AT LEAST SCATTERED COVERAGE DURING THE LATE AFTERNOON
HOURS...BUT WILL LEAN TOWARD SREF/ECMWF/GFS AND ONLY FORECAST
SLIGHT CHANCE POPS ATTM.
A COOL NIGHT IS EXPECTED TONIGHT...WITH LOWS IN THE 40S TO LOWER
50S. WEST FLOW AND BRIEF WAA FRIDAY WILL RESULT IN NEAR TO
PERHAPS SLIGHTLY ABOVE NORMAL TEMPS IN THE 70 TO 75 DEGREE RANGE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
PLEASANT WEATHER CONDITIONS ARE EXPECTED FOR THE WEEKEND AS HIGH
PRESSURE BUILDS ACROSS THE AREA ON SATURDAY...THEN OFFSHORE SUNDAY
MORNING. HIGH TEMPERATURES ON SATURDAY WILL BE IN THE MID TO UPPER
60S AND LOW TO MID 70S ON SUNDAY. A WARM FRONT LIFTS NORTH ON MONDAY
BRINGING A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS. INSTABILITY
SLOWLY INCREASES THROUGH THIS TIME...SO MENTIONED CHANCE THUNDER ON
TUESDAY FROM NYC NORTH/WEST. THE WARM FRONT SHOULD LIFT TO THE NE BY
WEDNESDAY MORNING...BUT COULD BE FOLLOWED BY A WEAK COLD FRONT OR
PRE-FRONTAL WEDNESDAY AFTERNOON INTO THURSDAY MORNING...WITH CHANCE
OF AFTERNOON SHOWERS AND THUNDERSTORMS ONCE AGAIN WEDNESDAY AND
THURSDAY.
TEMPERATURES WILL SLOWLY WARM UP DURING THE WEEK. WITH TEMPERATURES
STARTING OUT IN THE LOW TO MID 70S ON MONDAY...THEN LOW TO MID 80S
BY MIDWEEK.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
WEAK HIGH PRESSURE GIVES WAY TO LOW PRESSURE PASSING WELL SOUTH
AND EAST OF LONG ISLAND THROUGH TONIGHT.
EXPECTING MAINLY VFR CONDITIONS...ALTHOUGH MVFR CANNOT TOTALLY BE
RULED OUT AT TIMES DURING THE LIGHT RAIN LATER TODAY AND THIS
EVENING.
WINDS WILL BECOME MORE SOUTHERLY AT 10-15 KT BEFORE RETURNING TO
A MORE NORTHERLY FLOW LATE TONIGHT WHICH WILL AGAIN LOWER TO LESS
THAN 10 KT.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: HIGHER CHANCES FOR LIGHT RAIN AND MVFR AFTER
21Z. TIMING OF MORE SOUTHERLY WIND COULD BE OFF BY 1-2 HOURS.
KLGA FCSTER COMMENTS: HIGHER CHANCES FOR LIGHT RAIN AND MVFR AFTER
21Z. TIMING OF MORE SOUTHERLY WIND COULD BE OFF BY 1-2 HOURS.
KEWR FCSTER COMMENTS: HIGHER CHANCES FOR LIGHT RAIN AND MVFR AFTER
21Z. TIMING OF MORE SOUTHERLY WIND COULD BE OFF BY 1-2 HOURS.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: HIGHER CHANCES FOR LIGHT RAIN AND MVFR AFTER
23Z. TIMING OF MORE SOUTHERLY WIND COULD BE OFF BY 1-2 HOURS.
KHPN FCSTER COMMENTS: HIGHER CHANCES FOR LIGHT RAIN AND MVFR AFTER
03Z. TIMING OF MORE SOUTHERLY WIND COULD BE OFF BY 1-2 HOURS.
KISP FCSTER COMMENTS: HIGHER CHANCES FOR LIGHT RAIN AND MVFR AFTER
22Z. TIMING OF MORE SOUTHERLY WIND COULD BE OFF BY 1-2 HOURS.
.OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
.FRI-FRI NIGHT...POSSIBLE MVFR EARLY MORNING AND IN AFTERNOON.
OTHERWISE VFR. NW GUSTS 25-30 KT...LOWERING AT NIGHT WITH GUSTS
15-20 KT.
.SAT-SUN NIGHT...VFR. W GUSTS 15-20 KT DURING DAY SAT. SW GUSTS
15-25 KT DURING DAY SUN AND INTO EARLY SUN EVE.
.MON...POSSIBLE MVFR OR LOWER IN RAIN SHOWERS.
&&
.MARINE...
HIGH PRESSURE BRIEFLY BUILDS ACROSS THE WATERS TODAY. AS
SUCH...TRANQUIL WINDS AND SEAS ARE FORECAST. BY TONIGHT...THE HIGH
DEPARTS AND LOW PRESSURE APPROACHES AND TRACKS SOUTH AND EAST OF THE
WATERS. THIS LOW MOVES NORTHEAST AS A COLD FRONT APPROACHES FRIDAY
AFTERNOON. LIGHT NORTHERLY WINDS TONIGHT INTO FRIDAY MORNING TURN
TOWARD BACK TO THE WEST AND INCREASE DURING THE AFTERNOON. THERE
COULD VERY WELL BE 25 TO PERHAPS 30 KT GUSTS NEAR SHORE LATE IN
THE AFTERNOON...ESPECIALLY NY HARBOR AND WESTERN LI SOUND. WILL
HOLD OFF THOUGH ON ANY ADVISORIES ATTM DUE TO LATE 3RD
PERIOD...AND MAINLY A NEAR SHORE CONCERN.
TRANQUIL SEAS TONIGHT BUILDS LATE FRIDAY AFTERNOON IN RESPONSE TO
THE STRENGTHENING WESTERLY WINDS.
TRANQUIL CONDITIONS ARE EXPECTED SATURDAY AND SUNDAY MORNING...AS
HIGH PRESSURE BUILDS ACROSS THE AREA WATERS. SOUTHWEST FLOW
INCREASING TO 15-20 KT MAY BUILD OCEAN SEAS TO 5 FT SUNDAY
AFTERNOON/EVENING...ESPECIALLY FARTHER EAST WHERE A LONGER FETCH
WILL EXIST. OCEAN SEAS FALL BELOW SCA LEVELS BRIEFLY ON
MONDAY...THEN BUILD BACK TO SCA LEVELS ON TUESDAY.
&&
.FIRE WEATHER...
TODAY WILL REMAIN MAINLY CLOUDY AND COOL WITH LIGHT WINDS. SOME RAIN
IS EXPECTED LATE TODAY AND THROUGH TONIGHT...MAINLY ALONG THE COAST.
THEN...DRY WEATHER RETURNS FRIDAY. WEATHER CONDITIONS ON FRIDAY MAY
STILL BE CONDUCIVE TO GROWTH/SPREAD OF ANY FIRES THAT DEVELOP. MIN
RH ARE FORECAST TO BE IN THE 20S AND W-NW WINDS WILL GUST TO 25-30
MPH FRI AFTERNOON. KBDI IS IN THE 100S ACROSS MOST OF SRN CT AND THE
LOWER HUDSON VALLEY AND IN THE 200S ACROSS NYC METRO AND LONG
ISLAND...BUT MAY NOT BE FULLY REPRESENTATIVE OF THE PERSISTENT DRY
CONDITIONS THAT HAVE BEEN IN PLACE.
&&
.HYDROLOGY...
DRY THROUGH THIS MORNING. THEN THERE IS THE POTENTIAL
FOR AROUND A TENTH OF AN INCH OF RAIN ON AVERAGE NEAR THE COAST.
NORTHERN ZONES SUCH AS THE LOWER HUDSON VALLEY AND SRN CT...QPF
WOULD RANGE FROM A TRACE TO MAYBE A TENTH OF AN INCH.
THERE IS A CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS MONDAY
INTO THE MIDDLE OF THE WEEK. MODEL UNCERTAINTIES ON
TIMING/PLACEMENT OF ANY HEAVY RAIN ARE STILL TOO LARGE TO MERIT
MENTION OF SPECIFIC AMOUNTS...AND MAY NOT EVEN PAN PER MODEL
FORECASTS OUT GIVEN THE PERSISTENT DRY PATTERN THAT HAS BEEN IN
PLACE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
700 AM EDT THU MAY 21 2015
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL TRACK SOUTH AND EAST OF OUR REGION LATE
TODAY AND TONIGHT, THEN A COLD FRONT CROSSES OUR AREA LATER FRIDAY.
HIGH PRESSURE BUILDS IN SATURDAY BUT THEN SHIFTS OFFSHORE SATURDAY
NIGHT AND SUNDAY. THE NEXT COLD FRONT DROPS INTO OUR AREA SUNDAY
NIGHT INTO MONDAY, THEN AS LOW PRESSURE TRACKS FROM THE PLAINS TO
THE GREAT LAKES REGION THE FRONT LIFTS BACK NORTH AS A WARM FRONT
LATE MONDAY INTO TUESDAY. A COLD FRONT IS FORECAST TO REMAIN WELL TO
OUR WEST DURING WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
TODAY...HPC QPF AND 00Z/21 MODEL CONSENSUS HAS THE NORTHERN EDGE
OF THE MEASURABLE RAIN TODAY NEAR I-95. CALLED IT SHOWERS ON THE
NORTHERN EDGE OF THE RAIN SHIELD WHERE MORE SPORADIC. A PERIOD OF
MDT TO HEAVY RAIN APPEARS PROBABLE FAR SE NJ AND DELAWARE.
THIS 630AM FORECAST THEN TAKES INTO ACCOUNT THE HRRR AS WELL AS
THE NARRE THROUGH THIS MID AFTERNOON.
EXPANDED THE POTENTIAL FOR .01 NORTHWARD IN THIS ISSUANCE.
CONFIDENCE ON TEMPS/POPS IS BELOW AVERAGE FROM SE PA ACROSS
CENTRAL NJ WHERE GREATEST UNCERTAINTY EXISTS (KPHL- KTTN). TEMPS
WILL FALL INTO THE LOW AND MID 50S WHEN THE RAIN BECOMES STEADY. A
CHILLY DAY FOR THE DELMARVA. TEMPS WERE LOWERED SLIGHTLY IN THIS
UPDATE.
MEASURABLE RAIN IS NOT EXPECTED IN NE PA AND FAR NNJ TODAY (I80
NORTH).
LIGHT WIND WILL BE N-NE EARLY THIS MORNING THEN MIDDAY-THIS AFTN
BECOMES LIGHT SOUTH IN THE NORTH AND REMAINING E-NE ACROSS ACROSS
THE SOUTH.
WARMEST TEMPS MAY BE IN NNJ TODAY WHERE NO RAIN IS FCST.
FCST BASED ON A GENERAL 50 50 BLEND OF 00Z/21 NAM/GFS MOS.
CAUSE OF THE RAIN AND CLOUD COVER: INSTABILITY BURST WITH SLY FLOW
850 WAA BENEATH WSW FLOW AT MID LEVELS (700-500MB) WITH DECENT RRQ
250 JET AIDING LIFT. THIS AHEAD OF A RELATIVELY STRONG 500MB SHORT
WAVE MOVING ESEWD FROM THE MIDWEST THIS MORNING AND ARRIVING IN
THE UPPER OHIO VALLEY THIS EVENING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
LEFTOVER RAIN ALONG THE COAST AND A CHANCE OF A PERIOD OF RAIN OR
SHOWERS ELSEWHERE EARLY, THEN CLEARING TOWARD DAWN AS THE RELATIVELY
STRONG 500MB SHORT WAVE SEEN AS AN -80M 12 HR HFC PASSES THROUGH E
PA REACHING LI BY DAYBREAK FRIDAY.
PATCHY FOG POSSIBLE TOWARD DAWN IF IT CLEARS FAST ENOUGH AND IT
REMAINS DECOUPLED THROUGH THE NIGHT.
LIGHT WIND TREND W-NW OVERNIGHT.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
THE SYNOPTIC SETUP IS COMPRISED OF A CLOSED LOW ACROSS EASTERN
CANADA THAT SHIFTS EASTWARD FRIDAY AND OVER THE WEEKEND AS ENERGY
STARTS TO EJECT INTO THE CENTRAL AND SOUTHERN PLAINS. THE LATTER
WILL TEND TO BUILD A RIDGE FROM NEAR FLORIDA NORTHWESTWARD TOWARD
THE MIDWEST SATURDAY INTO MONDAY. THE RIDGE THEN STRENGTHENS SOME AS
IT SHIFTS EASTWARD MONDAY AND TUESDAY, HOWEVER IT SHOULD FLATTEN
SOME ON ITS NORTHERN SIDE. THE MAIN FEATURE OF INTEREST IS A COLD
FRONT THAT DROPS DOWN LATE SUNDAY INTO MONDAY, BUT THEN IT LIFTS
BACK NORTH AS A WARM FRONT AS THE RIDGE BUILDS. IT LOOKS TO TURN
RATHER WARM TO EVEN HOT NEXT WEEK AS THE UPPER-LEVEL RIDGE IS IN
PLACE. WE USED A MODEL BLEND FOR FRIDAY THROUGH SUNDAY, THEN THE 00Z
WPC GUIDANCE WITH CONTINUITY THEREAFTER. SOME TWEAKS WERE THEN MADE
FOLLOWING ADDITIONAL COLLABORATION WITH OUR NEIGHBORING OFFICES.
FOR FRIDAY AND SATURDAY...THE CLOSED LOW TO OUR NORTH IS FORECAST TO
BE SHIFTING EASTWARD DURING THIS TIME FRAME AS ENERGY EJECTS INTO
THE CENTRAL AND SOUTHERN PLAINS. THIS WILL TAKE SURFACE LOW PRESSURE
INTO THE CANADIAN MARITIMES FRIDAY AND A COLD FRONT THROUGH OUR AREA
LATE IN THE DAY. WHILE THERE IS SOME INCREASE IN MOISTURE AHEAD OF
THE FRONT AND ALSO SOME LOWER LEVEL INSTABILITY FORECAST, THE DEEP
WESTERLY FLOW SHOULD TEND TO LIMIT THE CONVERGENCE. WHILE SOME
ISOLATED SHOWERS CANNOT BE RULED OUT, WE OPTED TO KEEP THE FORECAST
FRIDAY DRY ATTM. THE PRESSURE GRADIENT TIGHTENS WITH BREEZY
CONDITIONS DURING FRIDAY, THEN THIS GRADUALLY RELAXES LATER FRIDAY
NIGHT AND SATURDAY AS SURFACE HIGH PRESSURE MOVES IN. A MUCH DRIER
AIRMASS FOLLOWS THE FRONT, AND THIS WILL SET THE STAGE FOR A CHILLY
FRIDAY NIGHT AND EARLY SATURDAY. THERE COULD BE SOME FROST FORMATION
EARLY SATURDAY MORNING ACROSS PORTIONS OF THE NORTHERN ZONES,
PENDING WE DECOUPLE. FOR NOW, WE INCLUDED A PATCHY FROST MENTION.
HIGH PRESSURE THEN BEGINS TO SHIFT OFFSHORE SATURDAY NIGHT AS
RIDGING BUILDS TO OUR WEST.
FOR SUNDAY AND MONDAY...A RIDGE TO OUR WEST WILL GRADUALLY BUILD
EASTWARD. SOME ENERGY SLIDING SOUTHEASTWARD ACROSS NEW ENGLAND WILL
DROP A COLD FRONT INTO OUR AREA SUNDAY NIGHT AND MONDAY. THIS
FEATURE GENERALLY LOOKS TO BE ON THE WEAK SIDE, AND THERE IS SOME
GUIDANCE THAT HOLDS THIS FRONT FARTHER TO THE NORTH IN THE FORM OF A
WARM FRONT. THE FRONT DOES NOT LOOK TO STAY IN PLACE LONG AS THE
BUILDING RIDGE ALOFT ALONG WITH SURFACE HIGH PRESSURE TO OUR EAST
WILL HELP REINFORCE A SOUTHWESTERLY FLOW. THEREFORE THE BOUNDARY
SHOULD MOVE NORTH AS A WARM FRONT DURING MONDAY AND MONDAY NIGHT.
THERE MAY BE SOME CONVECTION RIDING ALONG OR NEAR THIS FRONT,
HOWEVER THIS MAY NOT BE UNTIL LATE MONDAY AS THE RIDGE AXIS MOVES
ACROSS. A WARMER AIRMASS SHOULD OVERSPREAD THE AREA ESPECIALLY
MONDAY AS AN EXPANDING WARM SECTOR MOVES NORTH, AND SOME INCREASE IN
THE DEW POINTS WILL ALSO OCCUR.
FOR TUESDAY AND WEDNESDAY...WE SHOULD BE IN THE WARM SECTOR DURING
THIS TIME FRAME AS A SHORT WAVE ALOFT AND SURFACE LOW TRACKS TO OUR
NORTH, WHICH WILL FLATTEN THE RIDGE SOME. WHILE THE SURFACE COLD
FRONT IS CURRENTLY FORECAST TO STAY TO OUR WEST, SOME CONVECTION
CANNOT BE RULED OUT AS THERE ARE SOME INDICATIONS OF A LEE SIDE
TROUGH DEVELOPING IN THE PRESENCE OF A WARM TO HOT AIRMASS ALONG
WITH AN INCREASE IN THE HUMIDITY. SOME PLACES HAVE A GOOD CHC OF
REACHING 90 DEGREES EACH AFTERNOON.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
TODAY...VFR CIGS. LIGHT RAIN IS FORECAST TO SPREAD INTO OUR REGION
FROM THE WEST AND SOUTHWEST THIS MORNING. THE RAIN IS EXPECTED TO
REMAIN NEAR OR JUST SOUTH OF KABE. A PERIOD OF RAIN IS ANTICIPATED
FOR KILG, KPHL, KPNE AND KTTN DURING THE AFTN WITH THE CATEGORICAL
RAIN PROBABILITY RESTRICTED TO KILG. CONDITIONS SHOULD REMAIN IN
THE VFR CATEGORY AT THOSE LOCATIONS WITH CEILINGS STAYING ABOVE
3000 FEET AND VISIBILITY VALUES STAYING ABOVE 5 MILES.
THE RAIN IS FORECAST TO HAVE A GREATER IMPACT ON KMIV AND KACY
THAN ON OUR TAF SITES TO THE NORTH. CONDITIONS SHOULD DROP TO
MVFR AT KMIV AND KACY THIS AFTERNOON.
AFTER THIS MORNINGS LIGHT NE WIND TO START, A LIGHT SOUTHWEST
WIND MAY DEVELOP AT KRDG, KABE, KTTN, KPNE, KPHL AND KILG DURING
MIDDAY. THE WIND MAY REMAIN VARIABLE AT KMIV AND KACY OR IT COULD
RESETTLE INTO THE NORTHEAST OR EAST DURING THE AFTERNOON HOURS AT
THOSE LOCATIONS.
TONIGHT...MOSTLY VFR CIGS; ALTHOUGH, SOME LINGERING RAIN/SHWRS
MAY MEAN SOME SUB-VFR THROUGH THE FIRST PART OF THE NIGHT MAINLY
FROM AROUND KMIV/KACY AND SOUTH. LIGHT WIND TREND W-NW OVERNIGHT.
OUTLOOK...
FRIDAY...VFR OVERALL. A COLD FRONT MOVES THROUGH LATER IN THE DAY
WITH PERHAPS AN ISOLATED BRIEF SHOWER. WEST WINDS BECOMING NORTHWEST
AND GUSTING UP TO 25 KNOTS MAINLY DURING THE AFTERNOON AND EVENING,
THEN DIMINISHING.
SATURDAY...VFR. NORTHWEST WINDS AROUND 10 KNOTS.
SUNDAY...VFR. SOUTHWEST WINDS 10 TO 15 KNOTS, THEN TENDING TO BECOME
LIGHT AND VARIABLE AT NIGHT AS A FRONT DROPS NEAR OR INTO THE AREA.
MONDAY...MAINLY VFR. LIGHT AND VARIABLE WINDS BECOMING SOUTHWEST
AROUND 10 KNOTS. A FEW SHOWERS AND THUNDERSTORMS ARE POSSIBLE
ESPECIALLY IN THE AFTERNOON.
&&
.MARINE...
SAFE BOATING WEEK CONTINUES THROUGH FRIDAY MORNING.
THERE IS A NEW USCG SAFETY APP THAT SHOULD BE OF VALUE TO
MARINERS AND WAS JUST UNVEILED THIS WEEK:
HTTP:/WWW.USCG.MIL/MOBILE
THIS APP PROVIDES ADDITIONAL SAFE BOATING RESOURCES FOR MOBILE DEVICE
USERS. WHEN LOCATION ENABLED, USERS CAN RECEIVE THE LATEST WEATHER
REPORTS FROM THE CLOSEST NOAA BUOY AS WELL AS REPORT THE LOCATION
OF A HAZARD ON THE WATER. IT FEATURES AN EMERGENCY ASSISTANCE
BUTTON, WHICH CAN CALL THE CLOSEST CG COMMAND CENTER.
THE FORECAST:
ISSUED SCA FOR THE DE BAY ATLC WATERS TONIGHT. NCAROLINA LOW
INTENSIFIES IN ITS DEPARTURE AND SHOULD DEVELOP MARGINAL 5 FT
HAZARDOUS SEAS AND A FEW SCA GUSTS AROUND 25 KT OVERNIGHT NEAR
44009.
OTHERWISE NO MARINE HEADLINE ANTICIPATED THROUGH TONIGHT.
NORTHERLY WINDS EARLY TODAY TEND NORTHEAST NORTHEAST-EAST BY
DAYBREAK THEN ONSHORE SOUTHEAST THIS AFTERNOON. WINDS EVENTUALLY BECOMING
NORTHWEST EVERYWHERE LATER THIS THURSDAY NIGHT.
OUTLOOK...
FRIDAY...A COLD FRONT MOVES THROUGH THE AREA LATE IN THE DAY AND THE
EVENING AS LOW PRESSURE MOVES AWAY, WITH A NORTHWEST WIND IN ITS
WAKE. PRIOR TO THIS, SOME GUSTS TO NEAR 25 KNOTS SHOULD LINGER
ACROSS THE FAR SOUTHERN COASTAL WATERS EARLY. THE FORECAST SOUNDINGS
SHOW BETTER MIXING MOSTLY NEARSHORE DURING THE DAY, THEN EXPANDING
TO OFFSHORE AT NIGHT AS COLDER AIR MOVES IN AND THEREFORE A SMALL
CRAFT ADVISORY MAY BE NEEDED FOR LATER FRIDAY NIGHT.
SATURDAY AND SUNDAY...NORTHWEST WIND GUSTS TO 25 KNOTS MAY OCCUR TO
START SATURDAY, OTHERWISE THE CONDITIONS SHOULD BE BELOW ADVISORY
CRITERIA.
MONDAY...A SOUTHWESTERLY FLOW IS ANTICIPATED TO INCREASE SOME,
HOWEVER THE CONDITIONS OVERALL SHOULD BE BELOW ADVISORY CRITERIA.
SOME SHOWERS AND THUNDERSTORMS ARE POSSIBLE.
&&
.FIRE WEATHER...
FOR FRIDAY AFTERNOON, THERE MAY BE THE RISK FOR ENHANCED WILDFIRE
SPREAD AS WEST-NORTHWEST WINDS GUST TO 20-25 MPH AT TIMES. IN
ADDITION, THIS WILL COMBINE WITH RELATIVE HUMIDITY VALUES DROPPING
TO AROUND 30 PERCENT IN SOME AREAS ALONG WITH DRY FINE FUELS. THIS
WILL DEPEND ON HOW MUCH WETTING OCCURS LATER TODAY ESPECIALLY ACROSS
THE SOUTHERN AREAS.
&&
.RIP CURRENTS...
SST`S ABOVE NORMAL AND JUST OFF THE COAST SSTS WELL ABOVE NORMAL
BY ALMOST 3C. THIS IS NOT GOOD ONCE IT TURNS HOT AND BEACHES ARE
UNGUARDED, SWIMMERS MAY TAKE CHANCES AT UNGUARDED LOCATIONS. BE
SMART ABOUT ANY SWIMMING EARLY THIS SEASON. ATLANTIC COASTAL WATER
TEMPS ARE WARMING --UPPER 50S TO MID 60S.
RIP CURRENT AWARENESS WEEK FOR MT HOLLY IS JUNE 7-13 WITH PSAS
VIA PUBLIC INFORMATION STATEMENTS, SOCIAL MEDIA, NOAA WEATHER
RADIO AND ANY MEDIA INTERVIEWS DESIRED (CONTACT OFFICE).
FOR RIP CURRENTS: DESPITE ANTICIPATED PROJECTIONS OF LOW OR
MODERATE RISK THROUGH THE MEMORIAL DAY WEEKEND, EARLY SEASON
FATALITIES OCCUR WHEN SWIMMING AT UNGUARDED TIMES/LOCATIONS.
WEAKER SWIMMERS OR SWIMMING IN AREAS WHERE RIP CURRENTS ARE
STRONGER (JETTIES) CAN QUICKLY BECOME LIFE THREATENING. WHEN
TRAINED LIFEGUARDS ARE NOT NEARBY, TIMELY RESCUE IS MUCH LESS
LIKELY. LETS GET THROUGH THE MONTH OF MAY WITH ALL SWIMMERS SAFE!
SWIM IN THE PRESENCE OF LIFE GUARDS! THANK YOU.
&&
.CLIMATE...
**TOP 10 WARMEST MAY CONTINUES LIKELY IN PORTIONS OF THE FORECAST
AREA**
THE FIRST 19 DAYS OF MAY IN OUR FORECAST AREA WERE AVERAGING WITHIN
ABOUT 1/2 DEGREE OF 7 DEGREES ABOVE NORMAL.
BASED ON THE ENSEMBLE AND A FORECAST THAT IS DETERMINISTICALLY
CONSERVATIVE INCLUDING OUR 330 PM MAY 20 PROJECTIONS THROUGH THE
27TH AND THEN THE 00Z/21 CONSERVATIVE FTPRHA THEREAFTER THROUGH
THE 31ST...EASILY OUTLOOKS A TOP 10 WARMEST MAY ON RECORD.
FOR PHILADELPHIA...PERIOD OF RECORD BACK TO 1874. PROJECTING AN
AVG TEMP OF 68.7 TO 69.3 OR AROUND 5 DEGREES ABOVE NORMAL AND AT
THE LEAST, 3RD WARMEST ON RECORD. WARMEST WAS 70.8 IN 1991. THEN
69.2 2004.
FOR ALLENTOWN...POR TO 1922. YESTERDAY WE WERE PROJECTING 65.0 OR
5.1 DEGREES ABOVE NORMAL AND 8TH WARMEST ON RECORD. WARMEST WAS
67.2 IN 1991.
POSTED BECAUSE WE`RE EXPECTING OUR FIRST 90 IN PHILADELPHIA BY THE
MIDDLE OF NEXT WEEK.
NORMAL FIRST DATE OF 90 OR HIGHER.
PHILADELPHIA MAY 29
ALLENTOWN MAY 30
WILMINGTON JUNE 4
ATLANTIC CITY JUNE 11.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 8 AM EDT
FRIDAY FOR ANZ455.
&&
$$
SYNOPSIS...GORSE
NEAR TERM...DRAG 7A
SHORT TERM...DRAG
LONG TERM...GORSE
AVIATION...DRAG/GORSE 7A
MARINE...DRAG/GORSE
FIRE WEATHER...
RIP CURRENTS...
CLIMATE...
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
10 AM EDT THU MAY 21 2015
.DISCUSSION... CURRENT-THIS AFTERNOON...THE NASA VERTICAL WIND
PROFILERS SCATTERED ABOUT BREVARD COUNTY WERE DETECTING WEST TO
SOUTHWEST WINDS THROUGH 10000 FEET. THE 8AM/12Z SOUNDINGS FROM THE
FLORIDA RAOP SITES WERE INDICATING 500MB TEMPERATURES IN THE -9C TO -
10C RANGE AND A SLIGHTLY MORE MOIST ATMOSPHERE THAN WEDNESDAY.
SHOULD A SEA BREEZE BY EARLY AFTERNOON SOUTH OF CAPE CANAVERAL AND
BY MID AFTERNOON NORTH OF THE CAPE. THE HRRR IS INDICATING A LATE
AFTERNOON EAST COAST SEA BREEZE AND WEST WIND (SEA BREEZE) COLLISION
FROM SOUTHERN VOLUSIA COUNTY TO LAKE OKEECHOBEE. THIS LOOKS GOOD AND
WILL NOT CHANGE THE CURRENT FORECAST. PRIMARY CONCERNS WILL BE WIND
GUSTS AND HAIL WITH THE STRONGER STORMS.
.AVIATION...BRIEF...TOO BRIEF FOR A TEMPO GROUP...MVFR CEILINGS KLEE-
KSFB-KTIX AND SOUTH AS PATCHES OF STRATOCU MOVE NW-SE IN THE WARMING
LOWEST LAYERS.
PREVIOUS AVWX DISC...EXPECT A SIMILAR DIURNAL CONVECTIVE PATTERN TO
WED...AND AS SUCH ADDED TEMPO TS GROUPS TO DAB-SFB=TIX. ALSO HAVE
LATE EVENING VCTS (22Z-02Z) ALONG THE DAB-FPR CORRIDOR FOR LINGERING
STORMS THAT LINGER OR DRIFT OVER THE EAST COAST.
.MARINE... CURRENT-THIS AFTERNOON...BUOYS RECORDING 1 TO 2 FOOT SEAS
NEARSHORE AND TO 3 FEET AT BUOY 010 120NM OFFSHORE. THE NOAA BUOYS
AND CMAN SITES WERE RECORDING SOUTHWEST TO WEST WINDS AT 5 TO 10
KNOTS. SEA BREEZES WILL GIVE AN ONSHORE COMPONENT EARLY AFTERNOON
CAPE CANAVERAL SOUTH AND A MID TO LATE AFTERNOON ONSHORE COMPONENT
NORTH OF CAPE CANAVERAL. MAIN CONCERNS WILL BE STRONG WINDS FROM
STORMS MOVING OVER THE INDIAN RIVER LAGOON AND INTO THE NEARSHORE
WATERS.
PREVIOUS AFD
TODAY/TONIGHT...SHORT WAVE TROUGH MOVING THROUGH THE NERN CONUS WILL
SPIN UP THE TN/OH VALLEY SFC LOW AS IT MOVES ACROSS THE CAROLINAS
TODAY AND OFFSHORE. IN TURN...THIS WILL DRAG A SFC TROUGH THROUGH
NERN FL TODAY AND INTO ECFL BY TONIGHT. AHEAD OF THE SFC TROUGH...
ENHANCED RIBBON OF MOISTURE WILL SAG SEWD ACROSS THE NRN AND CTRL
CWA BY THIS AFTERNOON AND EVENING. WEAK MID LEVEL TROUGHING ALOFT
WITH EMBEDDED RIPPLES SLIDING EWD ACROSS NRN-CTRL FL SHOULD AID
DIURNAL CONVECTION.
IN LIGHT OF THIS...WENT 10-15PCT ABOVE GUIDANCE POPS FOR THIS AREA
RESULTING IN 40-50PCT FOR THE NRN 4 COS PLUS NRN BREVARD...AND 25-30
TO THE SOUTH. AS WAS THE CASE WEDNESDAY...WITH H50 TEMPS -9C/-10C
STRONG/SEVERE STORMS WILL BE POSSIBLE ALONG BOUNDARY INTERACTIONS
WITH ACTIVITY LINGERING A FEW HOURS PAST SUNSET.
SHADED MAXES A DEGREE ABOVE MAV MOS FOR THE MOST PART...GIVEN THAT
WED`S MAXES VERIFIED 1-3F HIGHER.
FRI...THE FRONTAL BOUNDARY WILL ADVANCE TO AROUND THE SOUTH CENTRAL
PENINSULA AND MAY BE HARD TO DISCERN LATER IN THE DAY. DEEPER
MOISTURE WILL LIE IN/AROUND THIS FEATURE WITH HIGHEST RAIN CHANCES
SOUTH FROM I-4. FOR NOW WILL GO WITH 20 TO 30 PERCENT ALONG THE I-4
CORRIDOR WITH 30 TO 50 POPS SOUTHWARD/INTERIOR AS AFTERNOON BOUNDARY
COLLISIONS WILL FAVOR MORE SHOWERS/ISOLD STORMS HERE. NORTHERLY FLOW
EARLY IN THE DAY WILL CONTINUE TO VEER TO NERLY THRU THE AFTERNOON.
NNW/NW STEERING FLOW REMAINS FORECAST UNDER 10 KTS SO SOME HEAVY
RAINFALL NOT OUT OF THE QUESTION. ANOTHER WARM DAY UNTIL THE ONSHORE
FLOW FILTERS INTO THE AREA BEHIND THE FRONT WITH MIDDLE 80S FORECAST
ALONG THE VOLUSIA COAST INCREASING INTO THE U80S/NEAR 90 DEGREES
FURTHER SOUTH ALONG THE COAST AND L90S...PERHAPS A FEW M90S
SOUTHWARD OVER THE INTERIOR IF ENOUGH SURFACE HEATING IS REALIZED.
OVERNIGHT LOWS IN THE U60S/L70S.
THE WEEKEND...ONSHORE FLOW IN THE LOW LEVELS WITH OCNL BREEZY
CONDITIONS POSSIBLE ALONG THE COAST. THE ECSB WILL MOVE INLAND EARLY
WITH ISOLATED SHOWERY PRECIPITATION POSSIBLE AREAWIDE BEFORE
NOON...THEN AFTERNOON/EVENING CONVECTION FAVORING THE INTERIOR
SOUTHWARD FROM ORLANDO AS WELL AS OVER THE WESTERN PENINSULA.
MORNING/EARLY AFTERNOON RAIN CHANCES FAVOR THE COAST WITH
AFTERNOON/EVENING CHANCES FAVORING THE INTERIOR ACROSS ECFL. HIGH
PRESSURE WILL RE-ESTABLISH ITSELF NORTH OF THE AREA LATER IN THE
WEEKEND PROMOTING THE DEEPER ONSHORE FLOW ACROSS THE AREA. L/M 80S
FOR HIGHS ALONG THE COAST AND UPPER 80S TO NEAR 90 DEGREES DEEPER
INTO THE INTERIOR. LOWS IN THE U60S/L70S...EXCEPT SOME M70S POSSIBLE
ALONG THE SPACE/TREASURE COASTS WHERE ONSHORE FLOW REMAINS ELEVATED.
MON-WED...THE RIDGE OF HIGH PRESSURE TO THE NORTH WILL SLIDE ONLY A
BIT FURTHER SOUTH THRU EARLY NEXT WEEK BUT WE RETAIN A DEEPER
ONSHORE FLOW OVER THE AREA. DEEPER CONVECTION NOT LIKELY BUT SHOWERY
PRECIPITATION WILL AGAIN FAVOR THE COAST IN THE MORNING/EARLY
AFTERNOON AND INTERIOR/WESTERN PENINSULA IN THE AFTERNOON IN A
PERSISTENT WEATHER PATTERN. THE EAST COAST SEA BREEZE WILL BE ACTIVE
EACH DAY PUSHING WELL INLAND IN THE AFTERNOON/EARLY EVENING.
HIGH/LOW TEMPERATURES COMPARABLE TO THE PREVIOUS PERIOD.
&&
.AVIATION...EXPECT A SIMILAR DIURNAL CONVECTIVE PATTERN TO WED...AND
AS SUCH ADDED TEMPO TS GROUPS TO DAB-SFB=TIX. ALSO HAVE LATE EVENING
VCTS (22Z-02Z) ALONG THE DAB-FPR CORRIDOR FOR LINGERING STORMS THAT
LINGER OR DRIFT OVER THE EAST COAST.
&&
.MARINE...TODAY/TONIGHT...SW FLOW AVERAGING 10-13KT WILL GIVE WAY TO
ONSHORE SEA BREEZE CIRC NEAR THE COAST IN THE AFTERNOON. SEAS 2-3FT
WITH HIGHER WINDS AND SEAS IN OFFSHORE MOVING STORMS...ESPECIALLY
NORTH OF THE CAPE AND NEAR THE COAST.
FRI...WEAK FRONTAL BOUNDARY IS EXPECTED TO SETTLE INTO SOUTH CENTRAL
FLORIDA AND WEAKEN FURTHER. NORTHERLY WINDS BEHIND THIS FEATURE WILL
VEER TO NNE INTO THE AFTERNOON...THEN NE/ENE THROUGH THE NIGHT. WIND
SPEEDS SHOULD BE AOB 15 KNOTS. SEAS 2-3 FT DURING THE DAY INCREASING
AWAY FROM THE COAST UP TO 4 FT FRI NIGHT.
SAT-MON...HIGH PRESSURE SLOWLY RE-ESTABLISHES ITSELF NORTH OF THE
WATERS WITH DEEPENING LOW-LEVEL ONSHORE FLOW. LIGHT SHOWERY
PRECIPITATION WILL BE FORECAST WITH FOCUS OF ATLC COASTAL SHOWERS AT
NIGHT AND IN THE MORNINGS ALONG THE COAST AND ACTIVITY FOCUSING
DEEPER INLAND IN THE AFTERNOON WITH THE ECSB. A STRONGER PRESSURE
GRADIENT WILL DEVELOP OVER THE AREA THIS WEEKEND WITH CAUTIONARY
STATEMENTS POSSIBLE AS EARLY AS SAT AFTERNOON FOR WINDS OFFSHORE
PERHAPS CONTINUING WELL OFFSHORE INTO SUN. OTHERWISE WINDS 10-15 KTS
INTRACOASTAL/NEAR SHORE WATERS. SEAS 3-4 FT ON SAT AND MAYBE
INCREASING TOWARDS 5 FT LATE IN THE DAY WITH THE STRONGER
WINDS...WITH EAST FETCH BUILDING SEAS TO 4-6 FT INTO SAT NIGHT INTO
SUN/MON OVER THE OPEN ATLC
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 92 69 86 71 / 50 20 10 10
MCO 93 72 93 72 / 40 20 30 20
MLB 91 71 88 75 / 30 30 20 20
VRB 91 71 89 74 / 20 30 30 20
LEE 92 71 90 71 / 40 20 30 20
SFB 93 72 90 71 / 50 20 30 20
ORL 94 73 90 72 / 40 20 30 20
FPR 90 71 89 73 / 20 30 30 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...WIMMER
LONG TERM/IMPACT WX...BRAGAW
AREA FORECAST DISCUSSION
NWS CARIBOU ME
912 AM EDT THU MAY 21 2015
.SYNOPSIS...
HIGH PRESSURE TO THE SOUTH WILL MOVE EAST TODAY. ANOTHER COLD
FRONT WILL APPROACH FROM CUBIC LATER TONIGHT AND MOVING THROUGH
THE REGION ON FRIDAYS WITH SHOWERS FOR THE REGION. CONDITIONS
WILL REMAIN UNSETTLED INTO STUART AN UPPER LOW MOVES ACROSS THE
REGION FROM CANAD.
&&
.NEAR TERM /THROUGH TONIGHT/...
910 AM UPDATE...THE FORECAST IS STILL PRETTY MUCH ON TRACK. MID
AND HIGH CLOUDS HAVE COME IN A BIT FASTER THAN PREVIOUSLY
ANTICIPATED, SO HAVE ADJUSTED ACCORDINGLY. THE LATEST HRRR
GUIDANCE CONTINUES TO INDICATE THAT THERE WILL BE ISOLATED TO
PERHAPS EVEN SCATTERED SHOWERS THIS AFTERNOON, WITH SOME ACTIVITY
MAKING IT ALL THE WAY TO BANGOR, ELLSWORTH, AND EVEN MACHIAS. MOST
OF THE OTHER MODELS ARE NOT NEARLY AS GENEROUS WITH THE PRECIP AND
KEEP IT MUCH FURTHER NORTH. BUT THE HRRR DID VERY WELL WITH THE
SHOWERS THAT DEVELOPED YESTERDAY, SO WENT AHEAD AND ADDED ISOLATED
AFTERNOON SHOWERS FOR EVERYWHERE BASICALLY NORTH OF BANGOR. NO
OTHER CHANGES WERE NEEDED AT THIS TIME.
PREVIOUS DISCUSSION...CLOUDS WILL INCREASE TODAY AS ANOTHER
FRONTAL BOUNDARY SLIDES TOWARDS THE REGION. AN UPPER DISTURBANCE
SEEN IN WATER VAPOR IMAGERY IS FORECAST BY THE NAM AND GFS TO
SWINGS ACROSS THE REGION. LLVL CONVERGENCE IN THE WESTERN AREAS
COMBINED W/SOME WEAK MID LEVEL FORCING COULD ALLOW FOR A FEW
SHOWERS LATER THIS AFTERNOON. DECIDED TO TAKE A CONSENSUS
APCH(NAM/GFS AND HRRR 3KM) AND BROUGHT 20-30% POPS INTO THE WNW
AREAS A BIT EARLIER THAN PREVIOUSLY FORECAST. THE REST OF THE CWA
WILL REMAIN DRY. DAYTIME TEMPERATURES ARE FORECAST TO BE IN THE
LOW/MID 60S NORTH AND WEST TO THE UPPER 60S CENTRAL AND DOWNEAST.
A WAVE OF LOW PRESSURE OVER SOUTHERN QUEBEC IS EXPECTED TO DEVELOP
ON THE FRONTAL BOUNDARY AND MOVE NE ACROSS NW MAINE. SHOWERS ARE
FORECAST TO MOVE INTO NORTHERN AND WESTERN AREAS OVERNIGHT. RAINFALL
AMOUNTS WILL BE LIGHT(<.05"). TEMPERATURES ARE EXPECTED TO BE
WARMER THAN THEY WERE THIS MORNING HOLDING IN THE 40S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
LOW PRESSURE WILL TRACK EAST OF THE GULF OF MAINE DURING FRIDAY.
STEADY RAIN ASSOCIATED WITH THIS LOW SHOULD REMAIN TO THE EAST OF
THE STATE. HOWEVER, SHOWERS ASSOCIATED WITH AN APPROACHING UPPER
LOW FROM THE NORTHWEST AND ATTENDANT COLD FRONT CAN BE EXPECTED ON
FRIDAY. THE COLD FRONT WILL MOVE EAST OF THE DOWN EAST COAST EARLY
FRIDAY EVENING WITH ANY LINGERING SHOWERS PUSHING OFFSHORE.
NORTHWEST WINDS BEHIND THE FRONT WILL USHER IN COLDER AIR FRIDAY
NIGHT. 850MB TEMPS FALL TO AROUND -5C BY 12Z SATURDAY WITH 925 MB
TEMPS DOWN TO AROUND 0C. WITH THE COLD AIR ALOFT WE COULD SEE A
FEW SNOW SHOWERS ACROSS NORTHERN AREAS AS THE 500 MB LOW TRACKS
ACROSS THE REGION. EXPECT GUSTY NORTHWEST WINDS ON SATURDAY AS LOW
PRESSURE REMAINS TO OUR NORTHEAST AND A RIDGE OF HIGH PRESSURE
BUILDS EAST. SKIES WILL BE PARTLY SUNNY ACROSS NORTHERN AND
CENTRAL AREAS WITH THE CHANCE OF A SHOWER AND PARTLY TO MOSTLY
SUNNY SKIES DOWN EAST. HIGHS ON SATURDAY WILL BE BELOW NORMAL FOR
THIS TIME OF YEAR WITH HIGHS EXPECTED TO RANGE FROM THE MID TO
UPPER 50S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
A SHORT WAVE IS EXPECTED TO APPROACH FROM THE NORTHWEST SATURDAY
EVENING AND CROSS THE REGION LATER SATURDAY NIGHT AND INTO EARLY
SUNDAY. EXPECT PARTLY TO MOSTLY CLOUDY SKIES SATURDAY NIGHT WITH
THE CHANCE FOR A SHOWER MAINLY ACROSS NORTHERN AREAS. HIGHS ON
SUNDAY WILL RANGE FROM THE LOW TO MID 60S NORTH AND CENTRAL AND
UPPER 60S TO NEAR 70 DOWN EAST. EXPECT MAINLY CLEAR SKIES SUNDAY
NIGHT FOLLOWED BY A MAINLY SUNNY AND WARM MEMORIAL DAY. CLOUDS
WILL INCREASE MONDAY NIGHT WITH A FEW SHOWERS EXPECTED AS WARM
FRONT LIFTS NORTHEAST TOWARD THE REGION. EXPECT A CHANCE FOR
SHOWERS AND PERHAPS AN ISLD TSTM TUESDAY INTO WEDNESDAY IN ADVANCE
OF A SLOW MOVING COLD FRONT FROM THE NORTHWEST. TEMPERATURES WILL
AVERAGE ABOVE NORMAL THROUGH MID WEEK.
&&
.AVIATION /13Z THURSDAY THROUGH MONDAY/...
NEAR TERM: VFR CONDITIONS THROUGH TONIGHT FOR ALL TERMINALS.
SHORT TERM: VFR BUT MVFR IN ANY RAIN SHOWERS FRIDAY AND RAIN/SNOW
SHOWERS FRIDAY NIGHT. VFR CONDITIONS EXPECTED SATURDAY THROUGH
MONDAY.
&&
.MARINE...
NEAR TERM: NO HEADLINES THROUGH TONIGHT. SEAS ARE TO REMAIN 2 TO 3
FT INTO TONIGHT W/WINDS 10 TO 15 KTS.
SHORT TERM: WINDS/SEAS MAY REACH SCA LEVELS FRIDAY NIGHT AND
SATURDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HASTINGS/HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HASTINGS/HEWITT/DUDA
MARINE...HASTINGS/HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS CARIBOU ME
704 AM EDT THU MAY 21 2015
.SYNOPSIS...
HIGH PRESSURE TO THE SOUTH WILL MOVE EAST TODAY. ANOTHER COLD
FRONT WILL APPROACH FROM CUBIC LATER TONIGHT AND MOVING THROUGH
THE REGION ON FRIDAYS WITH SHOWERS FOR THE REGION. CONDITIONS
WILL REMAIN UNSETTLED INTO STUART AN UPPER LOW MOVES ACROSS THE
REGION FROM CANAD.
&&
.NEAR TERM /THROUGH TONIGHT/...
7 AM UPDATE: 09Z SATE IMAGERY SHOWED MID/HIGH CLOUDS MOVING ENE
IN ASSOCIATION W/AN UPPER DISTURBANCE MOVING ACROSS NORTHERN NY AND
NORTHERN NEW ENGLAND. MOST OF THE METERS SHOWED THE HIGH CLOUDS TO
BE THIN. SUNSHINE WILL ALLOW FOR TEMPERATURES TO WARM AFTER A CHILLY
START. WINDS WILL PICK UP BY MID MORNING BACKING TO SW BY THE AFTERNOON.
PREVIOUS DISCUSSION...
CLOUDS WILL INCREASE TODAY AS ANOTHER FRONTAL BOUNDARY SLIDES
TOWARDS THE REGION. AN UPPER DISTURBANCE SEEN IN WATER VAPOR
IMAGERY IS FORECAST BY THE NAM AND GFS TO SWINGS ACROSS THE
REGION. LLVL CONVERGENCE IN THE WESTERN AREAS COMBINED W/SOME WEAK
MID LEVEL FORCING COULD ALLOW FOR A FEW SHOWERS LATER THIS
AFTERNOON. DECIDED TO TAKE A CONSENSUS APCH(NAM/GFS AND HRRR 3KM)
AND BROUGHT 20-30% POPS INTO THE WNW AREAS A BIT EARLIER THAN
PREVIOUSLY FORECAST. THE REST OF THE CWA WILL REMAIN DRY. DAYTIME
TEMPERATURES ARE FORECAST TO BE IN THE LOW/MID 60S NORTH AND WEST
TO THE UPPER 60S CENTRAL AND DOWNEAST.
A WAVE OF LOW PRESSURE OVER SOUTHERN QUEBEC IS EXPECTED TO DEVELOP
ON THE FRONTAL BOUNDARY AND MOVE NE ACROSS NW MAINE. SHOWERS ARE
FORECAST TO MOVE INTO NORTHERN AND WESTERN AREAS OVERNIGHT. RAINFALL
AMOUNTS WILL BE LIGHT(<.05"). TEMPERATURES ARE EXPECTED TO BE
WARMER THAN THEY WERE THIS MORNING HOLDING IN THE 40S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
LOW PRESSURE WILL TRACK EAST OF THE GULF OF MAINE DURING FRIDAY.
STEADY RAIN ASSOCIATED WITH THIS LOW SHOULD REMAIN TO THE EAST OF
THE STATE. HOWEVER, SHOWERS ASSOCIATED WITH AN APPROACHING UPPER
LOW FROM THE NORTHWEST AND ATTENDANT COLD FRONT CAN BE EXPECTED ON
FRIDAY. THE COLD FRONT WILL MOVE EAST OF THE DOWN EAST COAST EARLY
FRIDAY EVENING WITH ANY LINGERING SHOWERS PUSHING OFFSHORE.
NORTHWEST WINDS BEHIND THE FRONT WILL USHER IN COLDER AIR FRIDAY
NIGHT. 850MB TEMPS FALL TO AROUND -5C BY 12Z SATURDAY WITH 925 MB
TEMPS DOWN TO AROUND 0C. WITH THE COLD AIR ALOFT WE COULD SEE A
FEW SNOW SHOWERS ACROSS NORTHERN AREAS AS THE 500 MB LOW TRACKS
ACROSS THE REGION. EXPECT GUSTY NORTHWEST WINDS ON SATURDAY AS LOW
PRESSURE REMAINS TO OUR NORTHEAST AND A RIDGE OF HIGH PRESSURE
BUILDS EAST. SKIES WILL BE PARTLY SUNNY ACROSS NORTHERN AND
CENTRAL AREAS WITH THE CHANCE OF A SHOWER AND PARTLY TO MOSTLY
SUNNY SKIES DOWN EAST. HIGHS ON SATURDAY WILL BE BELOW NORMAL FOR
THIS TIME OF YEAR WITH HIGHS EXPECTED TO RANGE FROM THE MID TO
UPPER 50S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
A SHORT WAVE IS EXPECTED TO APPROACH FROM THE NORTHWEST SATURDAY
EVENING AND CROSS THE REGION LATER SATURDAY NIGHT AND INTO EARLY
SUNDAY. EXPECT PARTLY TO MOSTLY CLOUDY SKIES SATURDAY NIGHT WITH
THE CHANCE FOR A SHOWER MAINLY ACROSS NORTHERN AREAS. HIGHS ON
SUNDAY WILL RANGE FROM THE LOW TO MID 60S NORTH AND CENTRAL AND
UPPER 60S TO NEAR 70 DOWN EAST. EXPECT MAINLY CLEAR SKIES SUNDAY
NIGHT FOLLOWED BY A MAINLY SUNNY AND WARM MEMORIAL DAY. CLOUDS
WILL INCREASE MONDAY NIGHT WITH A FEW SHOWERS EXPECTED AS WARM
FRONT LIFTS NORTHEAST TOWARD THE REGION. EXPECT A CHANCE FOR
SHOWERS AND PERHAPS AN ISLD TSTM TUESDAY INTO WEDNESDAY IN ADVANCE
OF A SLOW MOVING COLD FRONT FROM THE NORTHWEST. TEMPERATURES WILL
AVERAGE ABOVE NORMAL THROUGH MID WEEK.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
NEAR TERM: VFR CONDITIONS THROUGH TONIGHT FOR ALL TERMINALS.
SHORT TERM: VFR BUT MVFR IN ANY RAIN SHOWERS FRIDAY AND RAIN/SNOW
SHOWERS FRIDAY NIGHT. VFR CONDITIONS EXPECTED SATURDAY THROUGH
MONDAY.
&&
.MARINE...
NEAR TERM: NO HEADLINES THROUGH TONIGHT. SEAS ARE TO REMAIN 2 TO 3
FT INTO TONIGHT W/WINDS 10 TO 15 KTS.
SHORT TERM: WINDS/SEAS MAY REACH SCA LEVELS FRIDAY NIGHT AND
SATURDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HEWITT/DUDA
MARINE...HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
852 AM PDT THU MAY 21 2015
.SYNOPSIS...A PACIFIC STORM WILL BRING PLENTY OF CLOUD COVER TO THE
AREA OVER THE NEXT FEW DAYS AND INCREASING CHANCES FOR SHOWERS AND
THUNDERSTORMS TODAY AND FRIDAY...MAINLY NORTH OF INTERSTATE 40.
COOLER BUT STILL MILD TEMPERATURES ARE EXPECTED TODAY FOLLOWED BY
MUCH COOLER CONDITIONS ON FRIDAY. SHOWER CHANCES WILL PERSIST MAINLY
ACROSS THE SOUTHERN GREAT BASIN...WITH A WARMING TREND THROUGH THE
HOLIDAY WEEKEND.
&&
.UPDATE...JETSTREAK OVER WESTERN ARIZONA THIS MORNING LEADING TO
SOME WEAK RADAR RETURNS OVER NORTHERN MOHAVE COUNTY. THIS PROBABLY
NOTHING MORE THAN VIRGA OR SPRINKLES. DID INCREASE POPS FOR THE
HIGHER TERRAIN OF NORTHERN MOHAVE COUNTY IN THE MORNING UPDATE.
OTHERWISE...AIR MASS WILL DESTABILZE ONCE AGAIN THIS AFTERNOON UNDER
INFLUENCE OF BROAD TROUGH OVER THE WESTERN STATES. CONVECTION WILL
OCCUR MAINLY OVER THE HIGHER TERRAIN OF INYO COUNTY AND SOUTHERN
NEVADA. LATEST 12Z GFS/NAM AND 14Z HRRR SUPPORT A SLIGHT CHANCE OF A
SHOWER OR THUNDERSTORM FOR THE LAS VEGAS VALLEY LATE THIS
AFTERNOON/EARLY EVENING FOR AREAS MAINLY WEST OF I-15. WILL LEAVE IN
FOR NOW, BUT MONITOR CU DEVELOPMENT AND LATER RUNS OF THE HRRR FOR
FURTHER UPDATES.
&&
.PREV DISCUSSION...
229 AM PDT THU MAY 21 2015
.SHORT TERM...THROUGH SATURDAY NIGHT.
LOW PRESSURE OFF THE WEST COAST THIS MORNING WILL BE THE WEATHER
MAKER FOR THE AREA THROUGH THE SHORT TERM. THIS MEANS INCREASING
CHANCES FOR SHOWERS AND THUNDERSTORMS, GUSTY WINDS AT TIMES AND
COOLER CONDITIONS HEADING INTO THE MEMORIAL DAY WEEKEND.
SHOWERS ARE EXPECTED LATER THIS MORNING OVER THE SIERRA AND THEN
SPREAD EAST ACROSS THE SOUTHERN GREAT BASIN DURING THE DAY. LOCAL
MODELS FORECAST A FEW SHOWERS OVER THE LAS VEGAS VALLEY LATE THIS
AFTERNOON INTO THE EVENING HOURS.
THE LOW IS FORECAST TO TRACK FROM NEAR POINT CONCEPTION ALONG THE
SOUTHERN CAL COAST THIS EVENING...ACROSS THE MOJAVE DESERT TONIGHT
INTO EARLY FRIDAY THEN LIFT NORTHEAST THROUGH MOHAVE COUNTY ARIZONA
INTO UTAH FRIDAY AND FRIDAY NIGHT. THIS WILL GIVE US THE BEST CHANCE
OF PRECIPITATION...ESPECIALLY ACROSS THE NORTHERN PORTIONS OF THE
CWA. MOISTURE/STABILITY PROFILES AND LIFT PROVIDED BY THE LOW AND
ITS ASSOCIATED JET WILL AID IN SHOWER AND THUNDERSTORM DEVELOPMENT.
MODEL SOLUTIONS DIVERGE ON SATURDAY REGARDING SHORTWAVE ENERGY
DIVING SOUTH ALONG THE WEST COAST AND ITS INTERATION WITH THE
DEPARTING LOW OVER UTAH. THE ECMWF IS VERY PROGRESSIVE WITH THIS
FEATURE AND TAKES IT HARMLESSLY INTO NORTHERN MEXICO SATURDAY NIGHT
WHILE THE GFS AND NAM ARE STRONGER AND SLOWER...INTERACTING WITH
MOISTURE OVER THE SOUTHERN GREAT BASIN SATURDAY. THESE SOLUTIONS
WHICH ARE SUPPORTED BY THE GFS ENSEMBLE MEAN...WOULD KEEP ACTIVE
WEATHER OVER THE NORTHERN FORECAST AREA INTO SATURDAY NIGHT.
OVERALL, TEMPERATURES ALOFT STAY ON WARMER SIDE AND SNOW LEVELS ARE
EXPECTED TO REMAIN QUITE HIGH...GENERALLY ABOVE 7500-8000 FEET. SNOW
ACCUMULATIONS UP TO 8 INCHES ARE POSSIBLE IN THE HIGHER TERRAIN OF
THE SIERRA BETWEEN 5 AM THIS MORNING AND 5 AM SATURDAY WHILE ONLY
TRACE TO LIGHT AMOUNTS ARE EXPECTED ELSEWHERE. RAIN AMOUNTS DURING
THE SAME TIME FRAME COULD RANGE FROM A FEW HUNDRETHS TO A TENTH OF
SO IN THE DESERTS WITH .25-.50 INCH IN THE SOUTHERN GREAT BASIN.
LOCALLY HEAVIER AMOUNTS WILL BE POSSIBLE WHERE THUNDERSTORMS FORM.
WIND GUSTS COULD BE STRONG AT TIME IN THE WESTERN MOJAVE DESERT
LATER TODAY AND AGAIN FRIDAY AFTERNOON BUT SHOULD STAY JUST UNDER
ADVISORY LEVELS. TEMPERATURES AREA GENERALLY EXPECTED TO BE ABOUT 5
DEGREES COOLER TODAY...THEN ANOTHER 5-8 DEGREES COOLER FRIDAY BEFORE
WARMING AGAIN...BUT STAYING WELL BELOW NORMAL...ON SATURDAY.
.LONG TERM...SUNDAY THROUGH WEDNESDAY.
A LOW PRESSURE SYSTEM WILL SLIDE INTO THE PACIFIC NORTHWEST SUNDAY
AND LINGER THERE THROUGH WEDNESDAY, AT LEAST ACCORDING TO THE 00Z
MODELS. MAYBE THEY ARE FINALLY GOING TO TREND TOWARD A COMMON
SOLUTION. FOR SUNDAY, WE WILL REMAIN UNDER THE INFLUENCE OF OUR
DEPARTING TROUGH. THE WESTERN EDGE OF THIS TROUGH FINALLY PUSHES
EAST WITH THE FINAL PIECE OF ENERGY SLIDING SOUTH THROUGH CALIFORNIA
AND INTO SOUTHERN ARIZONA. QUASI-ZONAL FLOW ALOFT SETS IN MONDAY,
QUICKLY FOLLOWED BY SOUTHWEST FLOW TUESDAY AHEAD OF ANOTHER
APPROACHING TROUGH. SOME SORT OF TROUGHING/SHORTWAVE ENERGY APPEARS
TO MOVE ACROSS THE REGION WEDNESDAY, EVEN THOUGH THE MODELS PRODUCE
THIS FEATURE IN DIFFERENT WAYS. GIVEN THE PATTERN EVOLUTION, A
CHANCE OF SHOWERS WILL REMAIN POSSIBLE PRETTY MUCH EVERY DAY, MAINLY
ACROSS THE SOUTHERN SIERRA AND HIGHER TERRAIN OF THE SOUTHERN GREAT
BASIN. TEMPERATURES WILL MODERATE A BIT, WARMING TO WITHIN A FEW OF
DEGREES OF NORMAL BY WEDNESDAY. SOUTH TO SOUTHWEST BREEZES ARE
LIKELY BOTH MONDAY AND TUESDAY AFTERNOON/EARLY EVENING. &&
$$
.AVIATION...FOR MCCARRAN... SOUTHERLY WINDS OF 8-10KTS TO CONTINUE
THROUGH THE OVERNIGHT HOURS THEN BACK TO THE SOUTHEAST FOR MUCH OF
THE DAY. SHOWERS AND A FEW THUNDERSTORMS ARE POSSIBLE TODAY AND
COULD IMPACT ALL APPROACH CORRIDORS. THERE REMAINS A SLIGHT CHANCE
OF A SHOWER OR THUNDERSTORM DEVELOPING IN THE LAS VEGAS VALLEY LATER
TODAY OR THIS EVENING.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...SHOWERS AND THUNDERSTORMS ARE POSSIBLE NORTH OF
INTERSTATE 40 TODAY AND FRIDAY. STRONG UPDRAFTS AND CONVECTIVE
TURBULENCE...GUSTY SURFACE WINDS...AND SMALL HAIL WILL BE POSSIBLE
WITH STRONGER STORM CELLS. OTHERWISE SOUTHERLY SURFACE WINDS IN THE
10-20KT RANGE WITH GUSTS TO 25KTS ARE EXPECTED TODAY.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
UPDATE...PIERCE
SHORT TERM/AVIATION...SALMEN
LONG TERM...PADDOCK
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1039 AM EDT THU MAY 21 2015
.SYNOPSIS...
STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE TODAY. THE HIGHEST
RISK FOR SEVERE WEATHER WILL BE ACROSS SOUTHEAST NORTH CAROLINA.
LOW PRESSURE WILL MOVE ALONG A WEAK FRONT TODAY. AS LOW PRESSURE
DEPARTS WELL TO OUR NORTHEAST...IT WILL DRAG A COLD FRONT ACROSS
THE AREA LATE IN THE DAY AND THIS EVENING. HIGH PRESSURE WILL
BUILD ACROSS THE EASTERN CAROLINAS FRIDAY AND SATURDAY. THE HIGH
WILL MOVE OFFSHORE SUNDAY...BRINGING A RETURN TO HIGHER HUMIDITY
BY TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM THURSDAY...EASTERN NC REMAINS IN A MARGINAL RISK
FOR SEVERE WEATHER. CONVECTION WAS LOCATED OFFSHORE THIS MORNING
AND ANY FOG LIFTED...BUT STRATUS IS STILL BREAKING UP WITH A
FAIRLY DECENT BLANKET OF STRATOCU OVER NORTH CAROLINA. EXPECT
STRATOCU TO DISSIPATE SOME WITH A GREATER AMOUNT OF SUNSHINE
MIXING IN. APPROACH OF A WAVE OF LOW PRESSURE AT THE SURFACE ALONG
WITH SHORTWAVE IN THE MID LEVELS WILL COMBINE WITH HEATING OF THE
DAY AND MOISTURE RICH AIR TO BEGIN TO TRIGGER SHOWERS AND
THUNDERSTORMS ACROSS THE EASTERN CAROLINAS LATE MORNING.
THE MID LEVEL SHORTWAVE WILL MOVE ACROSS THE FORECAST AREA NEAR
THE TIME OF PEAK HEATING WITH THE UPPER JET IN A FAVORABLE
POSITION FOR ORGANIZED STORMS TO DEVELOP. THE BEST MOISTURE WILL
BE LOCATED TO THE SOUTH OF WARM FRONT AND CLOSER TO THE COAST WITH
DEWPOINTS UP AROUND 70. THE MARGINAL AREA OUTLINED BY SPC LINES UP
WITH BEST CONVECTIVE PARAMETERS...WITH ML CAPE CLOSE TO 1200 J/KG
AND BULK SHEAR VALUES WILL REACH AROUND 35 KT...HIGHEST ACROSS
SOUTHEAST NORTH CAROLINA. DCAPE WILL BE ABOVE 500 AS SW-WESTERLY
FLOW ALOFT WILL PROMOTE DRYING THROUGH THE MID LEVELS AND A
GREATER INVERTED V TYPE PROFILE THROUGH THE AFTERNOON. THE
DOWNSLOPING WESTERLY FLOW WILL ALSO PRODUCE MORE SUBSIDENCE WHICH
COULD ACT AGAINST CONVECTIVE DEVELOPMENT....BUT THIS WESTERLY
FLOW ALOFT WILL ALSO ALLOW FOR GREATER VERTICAL SHEAR AND MAY SEE
A FEW LINE SEGMENTS DEVELOP WITH POTENTIAL FOR DAMAGING
WIND. CAN NOT RULE OUT SOME HAIL OR BRIEF TORNADO...AS WELL. EXPECT
THIS TO AFFECT MAINLY THE NORTHERN TIER COUNTIES OF LOCAL CWA AND
MAINLY OVER EASTERN NORTH CAROLINA. KEPT POPS HIGHEST IN THIS
AREA. POPS WILL TREND DOWN TO CHANCE AND SLIGHT CHANCE ACROSS MOST
OF SOUTH CAROLINA. ANY STORMS AND CONVECTIVE DEBRIS CLOUDS WILL
MOVE SWIFTLY OFF TO THE EAST IN A 25 TO 35 KT WESTERLY STEERING
FLOW.
THE LINGERING WEAK FRONT WHICH HAS PUSHED BACK NORTH AS A WARM
FRONT WILL GET NUDGED EAST THROUGH THE DAY AS AS SFC LOW SWEEPS
ACROSS THE CAROLINAS AND OFF SHORE BY THIS EVENING. THE BEST CHC
OF MORE WIDESPREAD CONVECTION WILL BE ALONG AND N OF THE LOW
PRESSURE TRACK....PROVIDING THE NECESSARY LIFT FOR SHOWERS AND
THUNDERSTORMS. THEREFORE AS LOW TRACKS OFF THE COAST BY EARLY THIS
EVENING ANY CONVECTION WILL COME TO AN END.
A TRAILING COLD FRONT SHOULD SWEEP OFFSHORE AS LOW PRESSURE PULLS
OFF TO THE NE INTO THIS EVE...BRINGING DRIER AND MORE STABLE AIR
INTO THE AREA OVERNIGHT. WE WILL BE ON THE SOUTHERN PERIPHERY OF
ANOTHER WEAK MID-LEVEL TROUGH PIVOTING AROUND UPPER LOW ACROSS
SOUTHEAST CANADA. THIS MAY BRING AN UPTICK IN CLOUD COVER
OVERNIGHT...BUT NO RAINFALL.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...FAIR WEATHER WITH LOW RELATIVE HUMIDITY
IS EXPECTED THROUGH THE PERIOD AS HIGH PRESSURE SETTLES OVER THE
AREA. MAX TEMPERATURES EACH DAY WILL BE IN THE UPPER 70S TO
LOWER 80S...THOUGH SATURDAY SHOULD BE A DEGREE OR TWO WARMER THAN
FRIDAY. MINS FRIDAY NIGHT WILL FALL TO THE UPPER 50S TO LOWER 60S
AND MODERATE SLIGHTLY TO THE LOW TO MID 60S SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...SURFACE HIGH PRESSURE WILL REMAIN OVER THE
AREA THROUGH THE PERIOD AS A HIGH PRESSURE RIDGE BUILDS IN ALOFT
BY THE MIDDLE OF THE WEEK. THE RESULT WILL BE FAIR WEATHER THROUGH
THE PERIOD BUT TEMPERATURES AND HUMIDITY WILL BE ON THE RISE. MAX
TEMPERATURES WILL MODERATE FROM LOW TO MID 80S SUNDAY TO MID 80S TO
AROUND 90 BY WEDNESDAY. MIN TEMPERATURES WILL ALSO BE ON THE RISE
THROUGH THE PERIOD...GOING FROM LOW TO MID 60S SUNDAY NIGHT TO UPPER
60S TO LOWER 70S BY WEDNESDAY NIGHT. DRY WEATHER IS EXPECTED
THROUGH MOST OF THE PERIOD...THOUGH A SLIGHTLY WEAKER UPPER RIDGE
WEDNESDAY COULD ALLOW FOR THE DEVELOPMENT OF ISOLATED THUNDERSTORMS
DURING THE AFTERNOON AND EVENING.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
PATCHY DENSE FOG SHOULD DISSIPATE FAIRLY RAPIDLY THIS MORNING AS
SOUTHWEST FLOW COMMENCES AHEAD OF LOW PRESSURE CENTERED JUST WEST OF
THE REGION. THIS SOUTHWEST FLOW WILL INCREASE THIS MORNING...WITH
GUSTS OVER 20 KTS EXPECTED BY LATE MORNING. THE HRRR MODEL CONTINUES
TO SHOW MODERATE CONVECTION OVER OUR NORTHERN COUNTIES. OUR NORTHERN
COASTAL COUNTIES STAND THE BEST CHANCE FOR SHOWERS AS THEY WILL
LIKELY HEAT UP THE MOST AND WILL HAVE THE LOW LEVEL CONVERGENCE OF
THE SEA BREEZE BOUNDARY. THE LOW AND ASSOCIATED CONVECTION WILL EXIT
THE AREA THIS EVENING...WITH NORTHERLY WINDS ON THE BACK SIDE.
EXTENDED OUTLOOK...VFR. FOG POSSIBLE MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM THURSDAY...SW WINDS 15 TO 20 KT AHEAD OF A COLD
FRONT...WILL SHIFT TO THE NW THIS EVE...AND THEN N OVERNIGHT AS
LOW PRESSURE TO OUR N MOVES FURTHER AWAY. A DEVELOPING NORTHERLY
SURGE WILL INCREASE WINDS TO AROUND 20 KT LATE TONIGHT AND WE WILL
BE NEAR SMALL CRAFT SHOULD EXERCISE CAUTION LEVELS. SEAS WILL BE 2
TO 4 FT TODAY WITH SOME 5 FT SEAS ACROSS THE OUTERMOST WATERS LATE
TONIGHT. WINDS AND SEAS WILL BE LOCALLY HIGHER IN SCATTERED TO
NUMEROUS THUNDERSTORMS TODAY AND THIS EVE.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...LOOKS LIKE A QUIET PERIOD ON THE WATERS WITH
NE WINDS OF 10 TO 15 KT FRIDAY INTO SATURDAY THAT WILL BECOME MORE
EASTERLY BY SATURDAY NIGHT. SEAS OF 3 FEET OR LESS ARE EXPECTED
THROUGH THE PERIOD.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 300 AM THURSDAY...SUMMER LIKE CONDITIONS WILL CONTINUE ON THE
WATERS WITH SE WINDS OF 10 TO 15 KT EXPECTED THROUGH THE FORECAST
PERIOD WITH SEAS OF 3 FT OR LESS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RGZ
SHORT TERM...RAN
LONG TERM...RAN
AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
650 AM EDT THU MAY 21 2015
.SYNOPSIS...
STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE TODAY. THE HIGHEST
RISK FOR SEVERE WEATHER WILL BE ACROSS SOUTHEAST NORTH CAROLINA.
LOW PRESSURE WILL MOVE ALONG A WEAK FRONT TODAY. AS LOW PRESSURE
DEPARTS WELL TO OUR NORTHEAST...IT WILL DRAG A COLD FRONT ACROSS
THE AREA LATE IN THE DAY AND THIS EVENING. HIGH PRESSURE WILL
BUILD ACROSS THE EASTERN CAROLINAS FRIDAY AND SATURDAY. THE HIGH
WILL MOVE OFFSHORE SUNDAY...BRINGING A RETURN TO HIGHER HUMIDITY
BY TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 600 AM THURSDAY...CONVECTION WAS LOCATED OFFSHORE THIS
MORNING. VISIBILITIES WERE AS LOW AS A HALF MILE IN PATCHY FOG
EARLY THIS MORNING. ANY FOG WILL LIFT AND DISSIPATE THROUGH 730
AM. THE CONVECTION WAS LOCATED OFFSHORE THIS MORNING. APPROACH OF
A SURFACE WAVE AND MID-LEVEL DISTURBANCE WILL BEGIN TO TRIGGER
SHOWERS AND THUNDERSTORMS ACROSS THE EASTERN CAROLINAS LATE
MORNING WITH THE HIGHEST CONCENTRATION OF THUNDERSTORMS EXPECTED
ACROSS EASTERN NORTH CAROLINA THIS AFTERNOON.
A WEAK FRONT WILL BE DRAPED ACROSS THE AREA TODAY. A WAVE OF LOW
PRESSURE AT THE SURFACE WILL MOVE ALONG THE FRONT...PROVIDING THE
NECESSARY LIFT FOR SHOWERS AND THUNDERSTORMS...ESPECIALLY ALONG
AND N OF THE LOW PRESSURE TRACK. A MID-LEVEL SHORTWAVE WILL MOVE
ACROSS THE FORECAST AREA NEAR THE TIME OF PEAK HEATING WITH THE
UPPER JET IN A FAVORABLE POSITION FOR ORGANIZED STORMS TO DEVELOP.
INSTABILITY WILL BE GROWING THROUGH THE MORNING AND EARLY
AFTERNOON...PEAKING AROUND 2500 J/KG AND POSSIBLY AS HIGH AS 3000
J/KG DURING THE AFTERNOON. BULK SHEAR VALUES WILL REACH AROUND 35
KT...HIGHEST ACROSS SOUTHEAST NORTH CAROLINA.
THUS...SEVERE WEATHER IS CERTAINLY POSSIBLE WITH THE HIGHEST
PROBABILITY ALONG AND NORTH OF THE LOW TRACK ACROSS SOUTHEAST NORTH
CAROLINA AND POINTS NORTH. WILL CARRY HIGHEST POPS...LIKELY TO
CATEGORICAL...IN THESE AREAS AS WE DO EXPECT THE CONVECTION TO
BECOME RATHER WELL ORGANIZED. WILL TREND POPS DOWN TO CHANCE AND
SLIGHT CHANCE ACROSS MOST OF SOUTH CAROLINA.
WHILE STRONGEST WINDS THIS AFTERNOON WILL BE N OF THE AREA...WE ARE
EXPECTING MID LEVEL WINDS TO REACH AROUND 40 KT. THE DIRECTION WILL
BE WESTERLY WHICH TENDS TO BE A DRYING AND MORE SUBSIDENT FLOW FOR
THE EASTERN CAROLINAS. THE MODEL SOUNDINGS ALSO SHOW THE DEVELOPMENT
OF INVERTED V SOUNDINGS...WHICH SIGNALS THE POTENTIAL FOR STRONG TO
PERHAPS DAMAGING WIND GUSTS AT THE SURFACE IN THE MORE PERSISTENT
STORMS.
A COLD FRONT SHOULD SWEEP OFFSHORE AS LOW PRESSURE PULLS OFF TO THE
NE LATE DAY AND THIS EVE...BRINGING AN END TO THE SHOWERS AND
THUNDERSTORMS AS DRIER AND MORE STABLE AIR REACHES THE AREA
OVERNIGHT. WE WILL BE ON THE SOUTHERN PERIPHERY OF ANOTHER WEAK
MID-LEVEL TROUGH PIVOTING AROUND UPPER LOW ACROSS SOUTHEAST
CANADA. THIS MAY BRING AN UPTICK IN CLOUD COVER OVERNIGHT...BUT
NO RAINFALL.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM THURSDAY...FAIR WEATHER WITH LOW RELATIVE HUMIDITY
IS EXPECTED THROUGH THE PERIOD AS HIGH PRESSURE SETTLES OVER THE
AREA. MAX TEMPERATURES EACH DAY WILL BE IN THE UPPER 70S TO
LOWER 80S...THOUGH SATURDAY SHOULD BE A DEGREE OR TWO WARMER THAN
FRIDAY. MINS FRIDAY NIGHT WILL FALL TO THE UPPER 50S TO LOWER 60S
AND MODERATE SLIGHTLY TO THE LOW TO MID 60S SATURDAY NIGHT.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...SURFACE HIGH PRESSURE WILL REMAIN OVER THE
AREA THROUGH THE PERIOD AS A HIGH PRESSURE RIDGE BUILDS IN ALOFT
BY THE MIDDLE OF THE WEEK. THE RESULT WILL BE FAIR WEATHER THROUGH
THE PERIOD BUT TEMPERATURES AND HUMIDITY WILL BE ON THE RISE. MAX
TEMPERATURES WILL MODERATE FROM LOW TO MID 80S SUNDAY TO MID 80S TO
AROUND 90 BY WEDNESDAY. MIN TEMPERATURES WILL ALSO BE ON THE RISE
THROUGH THE PERIOD...GOING FROM LOW TO MID 60S SUNDAY NIGHT TO UPPER
60S TO LOWER 70S BY WEDNESDAY NIGHT. DRY WEATHER IS EXPECTED
THROUGH MOST OF THE PERIOD...THOUGH A SLIGHTLY WEAKER UPPER RIDGE
WEDNESDAY COULD ALLOW FOR THE DEVELOPMENT OF ISOLATED THUNDERSTORMS
DURING THE AFTERNOON AND EVENING.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
PATCHY DENSE FOG SHOULD DISSIPATE FAIRLY RAPIDLY THIS MORNING AS
SOUTHWEST FLOW COMMENCES AHEAD OF LOW PRESSURE CENTERED JUST WEST OF
THE REGION. THIS SOUTHWEST FLOW WILL INCREASE THIS MORNING...WITH
GUSTS OVER 20 KTS EXPECTED BY LATE MORNING. THE HRRR MODEL CONTINUES
TO SHOW MODERATE CONVECTION OVER OUR NORTHERN COUNTIES. OUR NORTHERN
COASTAL COUNTIES STAND THE BEST CHANCE FOR SHOWERS AS THEY WILL
LIKELY HEAT UP THE MOST AND WILL HAVE THE LOW LEVEL CONVERGENCE OF
THE SEA BREEZE BOUNDARY. THE LOW AND ASSOCIATED CONVECTION WILL EXIT
THE AREA THIS EVENING...WITH NORTHERLY WINDS ON THE BACK SIDE.
EXTENDED OUTLOOK...VFR. FOG POSSIBLE MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 600 AM THURSDAY...SW WINDS 15 TO 20 KT AHEAD OF A COLD
FRONT...WILL SHIFT TO THE NW THIS EVE...AND THEN N OVERNIGHT AS
LOW PRESSURE TO OUR N MOVES FURTHER AWAY. A DEVELOPING NORTHERLY
SURGE WILL INCREASE WINDS TO AROUND 20 KT LATE TONIGHT AND WE WILL
BE NEAR SMALL CRAFT SHOULD EXERCISE CAUTION LEVELS. SEAS WILL BE 2
TO 4 FT TODAY WITH SOME 5 FT SEAS ACROSS THE OUTERMOST WATERS LATE
TONIGHT. WINDS AND SEAS WILL BE LOCALLY HIGHER IN SCATTERED TO
NUMEROUS THUNDERSTORMS TODAY AND THIS EVE.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...LOOKS LIKE A QUIET PERIOD ON THE WATERS WITH
NE WINDS OF 10 TO 15 KT FRIDAY INTO SATURDAY THAT WILL BECOME MORE
EASTERLY BY SATURDAY NIGHT. SEAS OF 3 FEET OR LESS ARE EXPECTED
THROUGH THE PERIOD.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 300 AM THURSDAY...SUMMER LIKE CONDITIONS WILL CONTINUE ON THE
WATERS WITH SE WINDS OF 10 TO 15 KT EXPECTED THROUGH THE FORECAST
PERIOD WITH SEAS OF 3 FT OR LESS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RJD
SHORT TERM...RAN
LONG TERM...RAN
AVIATION...43
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
718 AM EDT THU MAY 21 2015
.SYNOPSIS...
A SEASONABLY COOL WEATHER PATTERN WILL CONTINUE THROUGH THE END OF
THE WEEK WITH A RATHER CHILLY START TO THE WEEKEND. A GRADUAL
WARMING TREND IS FORECAST THROUGH THE EARLY TO MIDDLE PART OF NEXT
WEEK ALONG WITH AN INCREASING RISK FOR SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
EARLY AM WV LOOP SHOWS A WELL DEFINED MID LVL SHORTWAVE TRACKING
EASTWARD ACROSS S ONTARIO. LOW TO MID LVL THETA-E ADVECTION AHEAD
OF THE WAVE ALONG WITH MODEST HEIGHT FALLS AND PERHAPS SOME RIGHT
ENTRANCE REGION JET DYNAMICS ARE COMBINING TO PRODUCE SOME
SPOTTY/VERY LIGHT RAIN ACROSS EASTERN OHIO/WESTERN PA AS OF 0830Z.
UPSTREAM SFC REPORTS INDICATING ONLY A FEW HUNDREDTHS OF AN INCH
RAIN FROM THIS FEATURE OVR OHIO AND SUSPECT EVEN LESS OVR MOST OF
CENTRAL PA...WHERE DRY AIR IN THE LOW LVLS IS CURRENTLY
RESULTING IN VIRGA. WEAKENING SHORTWAVE WILL PASS NORTH OF PA
LATER THIS MORNING...CAUSING DWINDLING AREA OF -SHRA TO PRESS
EAST. LATEST 4KM NAM/HRRR INDICATE ONLY A SLIGHT CHC OF LINGERING
-SHRA BY NOON ACROSS THE SE COUNTIES.
A SECOND SHORTWAVE...DIVING INTO THE UPPER MIDWEST THIS AM...WILL
PUSH INTO WESTERN PA BY THIS EVENING. INCREASING LG SCALE FORCING
AHEAD OF THIS FEATURE WILL LIKELY PRODUCE ANOTHER ROUND OF SCT
-SHRA THIS EVENING. ALL NR TERM MDL INDICATE THE BEST CHC OF
MEASURABLE RAIN WILL BE ACROSS THE CENTRAL MTNS THIS
EVENING...ALONG PLUME OF SLIGHTLY HIGHER PWATS.
OVERCAST SKIES...COMBINED WITH AN ALREADY CHILLY AIR MASS OVR THE
AREA...WILL RESULT IN AN UNSEASONABLY COOL DAY WITH AFTERNOON
HIGHS 10 TO 20 DEGREES BELOW LATE MAY CLIMO...RANGING FROM 55-60F
OVER MOST OF CENTRAL PA.
TRENDED POPS DOWNWARD FROM NW TO SE EARLY TONIGHT AS DRIER AIR
ARRIVES IN WAKE OF PASSING SHORTWAVE. SFC LOW PASSING OFF THE MID
ATL COAST STRENGTHENS A BIT...WHICH SHOULD LEAD TO A SLIGHT
UPTICK IN NW WINDS INTO FRIDAY MORNING. LOWS SHOULD AVG IN THE
L-M40S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
THE MAIN LARGE SCALE UPPER TROUGH AXIS IS PROGGED TO ROTATE
THROUGH THE ERN GREAT LAKES AND NRN NEW ENGLAND ON DAY 2 WHICH
SHOULD DRIVE A RE-ENFORCING SFC COLD FRONT THROUGH CENTRAL PA.
MODEL CONSENSUS CONTINUES TO SUGGEST ISOLD/WDLY SCT SHOWERS WITH
THE FRONTAL PASSAGE BUT WITH VERY LIMITED MSTR KEPT POPS AOB 20
PCT. DAY 2 MAX TEMPS SHOULD MODERATE SOME BUT STILL AVG BELOW
NORMAL FOR THIS TIME OF YEAR.
BEHIND THE COLD FRONT...A SPRAWLING AREA OF HIGH PRESSURE WILL
BUILD INTO THE REGION FRI NIGHT/A.M. SATURDAY. CONFIDENCE
CONTINUES TO INCREASE FOR AREAS OF FROST ALONG THE ALLEGHENY
FRONT BY SATURDAY MORNING. COULD EVEN SEE SOME FROST IN THE
OUTLYING AREAS AROUND STATE COLLEGE. WITH A FAVORABLE PATTERN AND
SUPPORT FROM MODEL CONSENSUS...COLLABORATED WITH BUF/BGM ON A
FREEZE WATCH FOR THE NRN MTNS WITH FCST MINS IN THE 28-32F RANGE.
WILL ALSO CONTINUE TO HIGHLIGHT FROST RISK IN THE HWO AND LATER
SHIFTS CAN ADD FROST HEADLINES AS NEEDED.
AFTER A RATHER CHILLY START TO THE WEEKEND...TEMPS SHOULD REBOUND
NICELY ON SATURDAY WITH HIGHS GENERALLY FROM 65-70F. HIGH PRESSURE
SLIDES OFF THE MID ATLC COAST SATURDAY NIGHT WITH A WARMER RETURN
FLOW SETTING UP INTO SUNDAY.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ALL GUIDANCE CONTINUES TO SIGNAL A WARMING TREND INTO THE MIDDLE
OF NEXT WEEK...WITH HIGH CONFIDENCE IN ABOVE NORMAL TEMPERATURES
BY MEMORIAL DAY AS ANOMALOUS 500MB RIDGE BUILDS OVER THE EASTERN
U.S. GFS/ECMWF DISAGREE ON PLACEMENT OF WARM FRONTAL ZONE LIFTING
NWD FROM THE SRN PLAINS/LWR MS VLY. THIS WILL LKLY IMPACT PCPN
RISK EARLY NEXT WEEK. A COLD FRONT IS PROGGED TO APPROACH THE AREA
LATER IN THE WEEK. WITH LOW CONFIDENCE IN BOUNDARY PLACEMENT AT
THIS RANGE...WILL MAINTAIN DAILY RISK OF MAINLY AFTERNOON
THUNDERSTORMS GIVEN INCREASINGLY HUMID/MUGGY SUMMER-LIKE PATTERN.
&&
.AVIATION /11Z THURSDAY THROUGH MONDAY/...
A WEAK AREA OF LOW PRESSURE WILL TRACK SOUTH OF PENNSYLVANIA EARLY
THIS MORNING...BRINGING A SCT -SHRA TO THE CENTRAL AND SOUTHERN
PART OF THE STATE. DRY AIR AT LOW LEVELS SHOULD ENSURE VFR CONDS
OVER MOST OF THE AREA. HOWEVER...A MOISTENING SERLY FLOW ASCENDING
THE HIGHER TERRAIN OF SOUTH CENTRAL PA IS LIKELY TO PRODUCE MVFR
CIGS AT KJST/KAOO...AND POSSIBLY KUNV...DURING MUCH OF THE
DAYLIGHT HOURS. LATEST HRRR EVEN IMPLIES THE CHC OF IFR CIGS AT
KJST BTWN 13Z-16Z. HOWEVER...ODDS OF THIS STILL ONLY ARND 50 PCT.
IMPROVING FLYING CONDS EXPECTED THIS EVENING...AS WINDS SHIFT TO
THE NW...DRAWING DRIER AIR AND CLEARING SKIES INTO THE REGION.
OUTLOOK...
FRI-SUN...NO SIG WX EXPECTED.
MON...MAINLY VFR...MVFR POSS IN SHRA/TSRA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY MORNING
FOR PAZ004>006-010-011-037.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...FITZGERALD/STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...STEINBUGL
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1015 AM CDT THU MAY 21 2015
.AVIATION/18Z TAFS/...VFR THIS PERIOD WITH WESTERLY SURFACE FLOW
AHEAD OF FRONT DROPPING SOUTHWARD FROM NRN WI. PREFER THE DRIER
LOOK OF THE HRRR WITH RESPECT TO PRECIP COVERAGE. LATEST GUIDANCE
SUGGESTS FRONT DROPS THROUGH TAF SITES BETWEEN 01Z-03Z. BRIEF
PERIOD OF GUSTY NE WINDS POSSIBLE. HAVE ALSO KEPT THE EVENING
POPS WITH THIS FEATURE AS WELL. NAM/RAP SOUNDINGS SHOW LITTLE
POTENTIAL FOR POST FRONTAL MVFR CIGS. QUIET HIGH PRESSURE
DOMINATES FOR FRIDAY.
PC
&&
.PREV DISCUSSION... /ISSUED 312 AM CDT THU MAY 21 2015/
TODAY AND TONIGHT...FORECAST CONFIDENCE IS HIGH.
MOST PLACES SHOULD START OUT SUNNY THIS MORNING AS CLOUDS EXIT
THE FAR SOUTHEAST. TEMPS WILL REBOUND INTO THE UPPER 60S TO AROUND
70 THIS AFTERNOON...AS A WARMER AIR MASS PUSHES IN AHEAD OF AN
APPROACHING TROF/COLD FRONT DROPPING IN FROM THE NORTH FOR LATE
THIS AFTERNOON AND EVENING.
THE TROF...OR BACK DOOR COLD FRONT...WILL BE TIMED DURING MAX
DIABATIC HEATING...COUPLED WITH FAIRLY COLD TEMPS ALOFT. NEARLY
ALL THE MODELS DEVELOP SOME SHOWERS...MAYBE EVEN A RUMBLE OF
THUNDER...OVER THE FOX VALLEY OF EAST CENTRAL WISCONSIN VERY LATE
THIS AFTERNOON AND DRIFT IT SOUTH ACROSS THE EASTERN HALF OF THE
FORECAST AREA THIS EVENING.
THE FRONT WILL ACCELERATE DOWN THE LAKE SHORE WHILE THE SHOWERS
GRADUALLY DIMINISH WITH THE LOSS OF HEATING. WILL EXPAND THE POPS
A BIT GIVEN THE CONSENSUS. ALSO EXPECT A COUPLE OF HOURS OF GUSTY
NORTHEAST WINDS NEAR THE LAKE SHORE AFTER THE FRONT HITS. THINGS
WILL THEN CALM DOWN VERY QUICKLY THEREAFTER.
SHORT TERM...FRIDAY THROUGH SATURDAY NIGHT...FORECAST CONFIDENCE
IS MEDIUM.
MODELS ARE IN GOOD AGREEMENT WITH HIGH PRESSURE SLIDING SOUTHEAST
ACROSS THE WESTERN GREAT LAKES REGION FRIDAY AND FRIDAY NIGHT. THE
HIGH WILL BRING QUIET WEATHER. COOL TEMPERATURES IN THE 50S TO
AROUND 60 ARE EXPECTED NEAR LAKE MICHIGAN FRIDAY...WITH ONSHORE
WINDS. MILDER MID TO UPPER 60S ARE EXPECTED WELL INLAND. LOWS
SHOULD FALL INTO THE 40S FRIDAY NIGHT...WITH LIGHT SOUTH WINDS.
MODELS CONTINUE TO SHOW DIFFERENCES WITH PRECIPITATION TRENDS
SATURDAY AND SATURDAY NIGHT. THE GFS TAKES THE 850 MB JET AND
POINTS IT INTO THE REGION LATER SATURDAY INTO SATURDAY NIGHT. THE
NAM/CANADIAN/ECMWF ALL KEEP THIS FEATURE WEST OF THE AREA DURING
THIS TIME. THE MODELS DO SLIDE A MODEST 500 MB VORTICITY MAXIMUM
EAST NORTHEAST THROUGH THE AREA SATURDAY AFTERNOON...WITH THE
BUILDING 500 MB RIDGE TO THE WEST OF THE REGION. STEADY WARM AIR
ADVECTION DEVELOPS OVER THE REGION SATURDAY INTO SATURDAY
NIGHT...WHICH BRINGS MORE MOISTURE AS WELL.
AREA FORECAST SOUNDINGS RESPOND WITH DEEPER MOISTURE PROFILES
SATURDAY NIGHT...THOUGH LITTLE ELEVATED CAPE EXISTS. FOR
NOW...WILL LEAVE IN LOW POPS IN THE FAR WEST SATURDAY
AFTERNOON...THEN SPREAD THEM INTO THE REST OF THE AREA SATURDAY
NIGHT. COULD SEE THIS PERIOD ENDING UP DRY...IF NAM/ECMWF/CANADIAN
MODELS VERIFY OVER THE AGGRESSIVE GFS.
LONG TERM...SUNDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE IS
MEDIUM.
GFS/ECMWF CONTINUE TO DIFFER WITH TIMING OF PRECIPITATION SUNDAY.
THE GFS CONTINUES TO BE MORE AGGRESSIVE AND HAS QPF OVER THE AREA
WITH WARM AIR/MOISTURE ADVECTION CONTINUING. THE ECMWF PUSHES THE
FOCUSED WARM AIR ADVECTION INTO THE AREA SUNDAY AFTERNOON. AS
DISCUSSED EARLIER...THE ECMWF MAY BE MORE REALISTIC WITH ITS
SLOWER TIMING INTO THE AREA THAN THE AGGRESSIVE GFS. CONTINUED TO
USE CONSENSUS MODEL POPS FOR NOW ON SUNDAY...HIGHEST IN THE
SOUTHWEST COUNTIES.
THE GFS THEN KEEPS THE WARM FRONT WELL NORTH OF THE AREA SUNDAY
NIGHT INTO MONDAY...WITH THE ECMWF KEEPING IT OVER OR NEAR THE
AREA. BOTH MODELS DO SHOW SOUTHWEST FLOW AT 500 MB...WITH SEVERAL
VORTICITY MAXIMA PUSHING THROUGH. GFS VERY AGGRESSIVE WITH MEAN
LAYER CAPE/DEEP LAYER SHEAR MONDAY INTO MONDAY NIGHT...WHICH IS
PROBABLY OVERDONE. WILL CONTINUE WITH THE CONSENSUS MODEL POPS FOR
THIS PERIOD...AND KEEP THUNDER MENTION GOING. IF THE PRECIPITATION
OCCURS AS THE MODELS ARE SHOWING...WE SHOULD GET SOME BENEFICIAL
RAINFALL OVER THE AREA.
SOUTHWEST FLOW AT 500 MB LINGERS INTO THE MIDDLE OF THE WEEK ON
THE GFS/ECMWF...WITH SOUTH WINDS AT THE SURFACE HELPING KEEP WARM
AND MOIST CONDITIONS OVER THE AREA. WILL CONTINUE CONSENSUS POPS
FOR THIS PERIOD...AND KEPT THUNDER WORDING IN THIS PERIOD AS
WELL. MORE BENEFICIAL RAINFALL MAY OCCUR DURING THIS TIME.
AVIATION/12Z TAFS/...
VFR CONDITIONS EXPECTED DURING THE TAF PERIOD. THE MAIN
OPERATIONAL CONCERN IS LIKELY THE COLD FRONT THAT WILL BE TRACKING
SOUTH ACROSS THE AREA THIS EVENING. IT WILL BE ACCOMPANIED BY A
COUPLE HOUR PERIOD OF GUSTY NORTHEAST WINDS IN THE WAKE OF THE
FRONT FOR KMKE AND TO A WEAKER EXTENT AT KUES/KENW. A FEW SHOWERS
ARE ALSO POSSIBLE.
WINDS WILL SHIFT FROM WESTERLY TO NORTHEAST VERY ABRUPTLY AS THE
FRONT MOVES THROUGH. SOMETIMES THESE FRONTS WILL HAVE A BRIEF
PERIOD OF MVFR CIGS WITH THEM...BUT THEN CLEAR OUT VERY QUICKLY.
NOT SURE IF THAT WILL OCCUR IN THIS CASE. LOOK FOR THE WINDS TO
GUST TO AROUND 20KTS FOR AN HOUR OR SO...THEN SETTLE DOWN QUICKLY
THEREAFTER.
MARINE...A COLD FRONT WILL RACE DOWN THE LAKE EARLY THIS
EVENING...REACHING SHEBOYGAN AROUND 7 PM AND KENOSHA BY 9-10PM
THIS EVENING. WINDS WILL SHIFT ABRUPTLY FROM WESTERLY TO NORTHEAST
AND GUST TO AROUND 20KTS FOR A FEW HOURS BEFORE SETTLING BACK
DOWN.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...DAVIS
FRIDAY THROUGH WEDNESDAY...WOOD
AREA FORECAST DISCUSSION...UPDATED
NWS LITTLE ROCK AR
1237 PM CDT THU MAY 21 2015
.AVIATION...
MVFR CIGS CONTINUE DUE TO INVERSION OVER THE REGION. THERE WILL BE
LIFTING THIS AFTERNOON...BUT SOUTHERN SITES WILL REMAIN MVFR
THROUGH 22/00Z. WITH NORTHEAST WINDS OVERNIGHT...SOME LOWER CLOUDS
ARE EXPECTED DUE TO THE TERRAIN...BUT KEPT SCT FOR NOW. NEXT
SYSTEM WILL APPROACH AFTER SUNRISE FROM THE WEST...BUT ONLY AN
INCREASE IN CLOUD COVER FOR NOW.
&&
.PREV DISCUSSION... /ISSUED 412 AM CDT THU MAY 21 2015/
SHORT TERM...TODAY THROUGH SUNDAY NIGHT
INITIALLY UPDATED POPS ACROSS PORTIONS OF WESTERN AND SOUTHERN
ARKANSAS TO REFLECT CURRENT RADAR TRENDS AS WELL AS TREND TOWARDS
THE HRRR WHICH SHOWS PRECIPITATION CONTINUING FOR MUCH OF THE FIRST
HALF OF THE DAY ACROSS SOUTHERN ARKANSAS. PRECIP SHOULD CONTINUE TO
WEAKEN AND SPREAD TO THE SOUTH AS SLOW MOVING COLD FRONT CONTINUES
TO MOVE SOUTH.
CONTINUED THE TREND OF LOWERING TEMPS AND GOING BELOW GUIDANCE FOR
THURSDAY AND FRIDAY WITH STRONG NORTHERLY FLOW IN PLACE. AT THIS
POINT..TEMPERATURES WILL BE RUNNING TEN TO FIFTEEN DEGREES BELOW
NORMAL IN MOST LOCATIONS ACROSS THE STATE.
HIGH PRESSURE AT THE SURFACE BEGINS TO SHIFT OFF TO THE EAST LATE
FRIDAY ALLOWING A RETURN OF MOIST SOUTHERLY FLOW. SOUTHERLY FLOW
WILL BE DEEP AND MOISTURE WILL INCREASE DRAMATICALLY LATE SATURDAY.
BEGAN TO TREND DEWPOINTS UP AT THIS POINT WITH RAW MODELS SUGGESTING
70 PLUS DEWPOINTS WILL BE IN PLACE ACROSS SW ARKANSAS.
AT THIS POINT THERE STILL REMAINS SOME UNCERTAINTY ON THE SEVERE
WEATHER POTENTIAL. BUT MODEL SOUNDINGS DO SUGGEST SOME STRONGER
THUNDERSTORMS WILL BE POSSIBLE ON SUNDAY ACROSS WESTERN ARKANSAS.
RAINFALL TOTALS WILL GENERALLY BE LIGHT AND LIMITED TO WESTERN
ARKANSAS THROUGH THE FIRST HALF OF THE WEEKEND. RAINFALL CHANCES AND
QPF INCREASE SUNDAY EVENING WITH AN ADDITIONAL ONE TO TWO INCHES
POSSIBLE. WESTERN ARKANSAS HAS BEEN FAIRLY HARD HIT IN THE PAST FEW
WEEKS WITH HEAVY RAIN...AND AN ADDITIONAL ROUND OF HEAVY RAIN WILL
LIKELY BE PROBLEMATIC. THIS IS STILL A FEW DAYS OUT...BUT BEARS
WATCHING IN FUTURE FORECASTS.
LONG TERM...MONDAY THROUGH WEDNESDAY
NO SIG CHGS WERE MADE TO THE CURRENT FCST AS THE LATEST MODEL TRENDS
CONT TO INDC AN UNSETTLED WX PATTERN ACRS THE MID SOUTH. A
PERSISTENT SWLY FLOW ALOFT WL CONT TO BRING SEVERAL UPR LVL IMPULSES
NEWD THRU AR. THESE FEATURES WL INTERACT WITH THE MOIST AIRMASS IN
PLACE TO PRODUCE GOOD CHCS OF SHRA/TSRA. WITH SOILS ALREADY QUITE
SATURATED...ANY ADDITIONAL RAINFALL WL ONLY ENHANCE THE CHCS OF
ADDITIONAL FLOODING OVR MUCH OF THE AREA.
SOME OF THE MODELS DO INDC THAT THE UPR PATTERN WL DE-AMPLIFY OVR
THE SRN STATES HEADING INTO THE MIDDLE OF NEXT WEEK. THIS WL RESULT
IN DRIER CONDS FOR THE FA.
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AVIATION...58
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
316 PM PDT Thu May 21 2015
.Synopsis...
Mild weather with mountain showers and thunderstorms will continue
through Friday. Warmer temperatures with fewer mountain showers
expected this weekend into next week.
&&
.Discussion...
A broad upper level trough remains quasi-stationary along the West
Coast, with blocking ridge situated over the Rockies. Several
shortwaves have been rotating through this upper trough, and the
current one is moving toward the California coast today.
Widespread showers and thunderstorms have once again developed
this afternoon across the interior mountains of Northern
California once again. Lightning networks havent detected quite as
much lightning as yesterday, but today`s showers do seem to be
producing more in the way of precipitation. We`ve also seen a few
reports of snow above 8000 ft or so along the high Sierra. With
southeast to easterly flow aloft, some showers may try to work
their way down the hill toward the Valley this evening into Friday
morning. The ARW, NMM, and HRRR all hint at this possibility.
The aforementioned shortwave pushes south toward Southern
California on Friday, with steering flow becoming more northerly.
While we should still expect some mountain showers and
thunderstorms Friday afternoon, they shouldn`t be as widespread.
Northerly flow aloft will continue over Northern California
through the weekend. This should promote warmer weather, with
temperatures closer to normal. Isolated showers will still be
possible over the mountains, but confined to primarily Lake Tahoe
and southward.
Dang
&&
.Extended Discussion (Monday through Thursday)
For the extended period, the ability of the general upper trough
pattern over the region to persist through the rest of May is
impressive. with no significant heat-ups in sight. Upper low
pressure systems with weak short waves will pass through at times.
Unlike the current system, most of the lows will be centered to the
north and east of the forecast area. Most of the instability will
linger over the mountains, with afternoon heating bringing some
thunderstorms. The Valley should remain generally dry.
Temperatures will gradually warm to near to slightly above normal
levels by mid week on. Daytime highs in the valley will generally
be in the low to mid 80s with 70s in Delta Breeze influenced areas
(upper 60s for the Vallejo/Benicia area). Mountain highs will
range in the 50s/60s while Foothills warm into the 70s. EK
&&
.Aviation...
General VFR conditions expected for tonight, except in
SCT showers and ISO evening thunderstorms in the mountains and
foothills, possibly passing through the northern Sacramento Valley
. Could see some bkn020-025 cigs for the Delta and into the
southern Sacramento Valley 12-18z Friday morning. The Delta could
see gusts to 30kt tonight, with southwest gusts to around 20kt for
the Sacramento metro area through 05z. EK
&&
.STO Watches/Warnings/Advisories...
None.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1102 AM PDT THU MAY 21 2015
.SYNOPSIS...A LOW PRESSURE TROUGH OVER THE WEST COAST WILL KEEP COOLER
THAN NORMAL WEATHER FOR THE AREA ALONG WITH THE POSSIBILITY FOR LIGHT
SHOWERS THROUGH THE REST OF THE WORK WEEK. SLIGHT WARMING CAN BE
EXPECTED OVER THE WEEKEND AS A WEAK RIDGE STARTS TO BUILD INTO
OUR AREA.
&&
.DISCUSSION...AS OF 08:45 AM PDT THURSDAY...DEEP STRATUS DECK
COVERS MUCH OF THE BAY AREA THIS MORNING...MOSTLY CLOUDY START TO
THE DAY. INTERESTING TO NOTE THE CLOUDS ARE NOT YOUR TYPICAL
MARINE LAYER...SODARS AND PROFILERS DO NOT INDICATE A DEFINED
MARINE LAYER. THE KOAK SOUNDING ON THE OTHER HAND DOES SHOW A
MOIST LOWER 5K FEET. SYNOPTICALLY SPEAKING...A WEAK UPPER LEVEL
DISTURBANCE IS CURRENTLY SITTING OFF THE SF BAY COAST. THE
ASSOCIATED LIFT AND MOIST LOWER 5K FT HELPED TO PRODUCE SOME LIGHT
SHOWERS OVERNIGHT WITH SEVERAL STATIONS MEASURING UP TO A TENTH.
FOR THE REST OF TODAY...ANOTHER STRONGER UPPER LOW IS FORECAST TO
DROP SOUTHWARD THROUGH THE BASE OF A BROAD UPPER TROUGH. THE
UPPER LOW CAN BE SEEN ON THE WATER VAPOR NEAR 130W. LATEST SHORT
TERM MODELS...THE HRRR AND RAP BOTH INDICATE INCREASED SHOWER
ACTIVITY THIS AFTERNOON AS THE UPPER LOW DEEPENS OFF THE COAST.
THE BEST CHANCE FOR SHOWERS WILL BE OVER TERRAIN FAVORED
LOCATIONS. IN FACT...THE LATEST NAM/HRRR INDICATE A LITTLE BIT OF
SFC INSTABILITY OVER THE E BAY HILLS AND THE GABILAN RANGE THIS
AFTERNOON. THEREFORE COULD NOT TOTALLY RULE OUT SOME THUNDER AS WELL.
GIVEN THE UNCERTAINTY OF ACTUAL LOCATIONS FOR SHOWER
ACTIVITY...LATEST FORECAST HAS BLANKET COVERAGE OF SHOWERS THIS
AFTERNOON. NO MAJOR UPDATE IS NEEDED AT THIS TIME...BUT WILL LIKE
TWEAK THE WEATHER GRIDS TO BETTER REFLECT REALITY THIS AFTERNOON.
&&
.PREV DISCUSSION...AS OF 3:58 AM PDT THURSDAY...THE TROUGH AND
UPPER LOW WILL MOVE SOUTH AND EAST OF THE AREA BY LATE FRIDAY WITH
HIGH PRESSURE BUILDING INLAND DURING THE WEEKEND FROM THE EASTERN
PACIFIC. THIS WILL USHER IN A SHORT-LIVED WARMING TREND FOR
SATURDAY AND SUNDAY. BY EARLY NEXT WEEK...THOUGH..ANOTHER TROUGH
WILL SET UP ALONG THE COAST FOR A RETURN TO BELOW-NORMAL
TEMPERATURES.
&&
.AVIATION...AS OF 11:00 AM PDT THURSDAY...WIDESPREAD CLOUDS TODAY
ALONG WITH A DEEP ALBEIT POORLY DEFINED MARINE LAYER PLUS ONSHORE
SURFACE FLOW WILL KEEPS CIGS GOING IN ALL SPOTS THROUGH THE
PERIOD. DID MAKE SOME ADJUSTMENTS TO THE TAFS FROM THE PREVIOUS
PACKAGE TO KEEP CIGS LOWER IN MOST SPOTS. MVFR GENERALLY EXPECTED
TONIGHT. WINDS SPEEDS MOSTLY UNDER 15 KT EXCEPT AT SFO. A FEW LIGHT
SHOWERS ALSO POSSIBLE THROUGH THE PERIOD. MODERATE CONFIDENCE.
VICINITY OF KSFO...STILL SHOWING BKN015 ON THE 5 MINUTE OB
ALTHOUGH CAMS ARE SHOWING DEFINITE BREAKS AND LIFTING. WIDESPREAD
CLOUDS THROUGH THE AREA ALONG WITH WESTERLY FLOW AT THE SURFACE
SHOULD KEEPS CIGS GOING ALL DAY UNDER 5KFT. WESTERLY WINDS FROM
21Z TO 02Z AROUND 15 KT FROM 260 TO 280. MODERATE CONFIDENCE.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...MVFR THROUGH THE PERIOD DUE TO
PERSISTENT ONSHORE FLOW PLUS DEEP MARINE LAYER. SPEEDS WILL PICK
UP THROUGH THE DAY WITH WESTERLY VALUES OF 8 TO 12 KT AFTER 20Z.
LOCALLY HIGHER GUSTS TO KSNS POSSIBLE. MODERATE CONFIDENCE.
&&
.MARINE...AS OF 11:00 AM PDT THURSDAY...A STORM SYSTEM WILL SLIDE
SOUTH ALONG THE COAST TODAY PROMOTING A POSSIBILITY OF SHOWERS
ACROSS THE COASTAL WATERS. GENERALLY LIGHT WINDS AND GENTLE SEAS
ARE EXPECTED THROUGH FRIDAY AS THE STORM PASSES. NORTHERLY WINDS
WILL INCREASE BEHIND THE DEPARTING STORM SYSTEM FRIDAY EVENING AS
THE SURFACE PRESSURE GRADIENT STRENGTHENS. THE INCREASING WINDS
WILL RESULT IN DETERIORATING SEA CONDITIONS.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 1 PM
&&
$$
PUBLIC FORECAST: MM
AVIATION/MARINE: BELL
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AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
339 PM MDT THU MAY 21 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 339 PM MDT THU MAY 21 2015
CLOUD COVER OVER THE FORECSAT AREA HAS BEEN INCREASING AS AN
EJECTING UPPER LEVEL TROUGH ROTATES INTO THE STATE FROM THE SOUTH.
SCATTERED SHOWER ACTIVITY HAS DEVELOPED OVER THE MOUNTAINS BUT
CONVECTION ON THE PLAINS HAS BEEN LIMITED BY THE STABLE LAYER IN
PLACE ACROSS NORTHEAST COLORADO. LATER THIS EVENING...DYNAMIC
FORCING ALOFT SHOULD PRODUCE A WIDESPREAD SHIELD OF PRECIPITATION
THAT EXTENDS FROM THE MOUNTAINS OUT ACROSS THE PLAINS. SNOW LEVELS
IN THE MOUNTAINS SHOULD GRADUALLY COME DOWN...BUT ONLY TO ABOUT
9500 OR 10 THOUSAND FEET. HIGHER MOUNTAIN PASSES ARE EXPECTED TO
PICK UP SEVERAL INCHES OF SNOW...AND THE WINTER WEATHER ADVISORY
REMAINS IN EFFECT FOR THIS.
SHORT RANGE MODELS CONTINUE TO SHOW GENERALLY LIGHT AMOUNTS OF QPF
FROM THIS SYSTEM...WITH THE RAP RUN SHOWING ONE-HALF INCH OR LESS
ACROSS THE PLAINS. ANY RAIN THAT FALLS WILL NOT TAKE VERY LONG TO
FIND ITS WAY TO CREEKS AND STREAMS SINCE THE GROUND REMAINS SO
CLOSE TO SATURATION. LIGHTER AMOUNTS OF RAIN SHOULD REDUCE THE
STRAIN ON THE HYDROLOGIC SITUATION. RIVER LEVELS IN THE DENVER AND
BOULDER AREA HAVE PLENTY OF CAPACITY TO HANDLE TONIGHTS RAINFALL.
LINGERING LIGHT RAIN SHOWERS ARE EXPECTED FRIDAY MORNING AS THE
UPPER TROUGH SLOWLY EXITS THE STATE. THERE SHOULD BE A BREAK IN
THE RAIN BY MIDDAY...BUT AFTERNOON HEATING OF THE MOIST AIRMASS
MAY DE-STABILIZE THE ATMOSPHERE AND PRODUCE SCATTERED
THUNDERSTORMS LATE IN THE AFTERNOON. TEMPERATURES ARE FORECAST TO
BE 5-10 DEGREES WARMER THAN THIS AFTERNOON. THE THREAT OF
LOCALIZED FLOOD PROBLEMS FRIDAY AFTERNOON WILL HINGE ON HOW MUCH
RAIN FALLS TONIGHT AND WHETHER AFTERNOON STORMS TRACK OVER AREAS
THAT RECEIVE APPRECIABLE RAIN TONIGHT.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 339 PM MDT THU MAY 21 2015
SCATTERED RAIN SHOWERS AND ISOLATED THUNDERSTORMS ON FRIDAY
EVENING ARE EXPECTED TO GRADUALLY DECREASE AS THE AIRMASS
STABILIZES...WITH MOST AREAS SEEING PARTIAL CLEARING OVERNIGHT.
SATURDAY IS SHAPING UP TO BE A MORE ACTIVE WEATHER DAY. THE LATEST
MODEL RUNS INDICATE A STRONGER WAVE WITH LARGE SCALE Q-G
ASCENT...NOW LOCATED IN THE EASTERN PACIFIC...ROTATING NORTHEAST
OUT OF THE SOUTHWEST U.S. TROUGH. THE FORECAST AREA WILL LIKELY
RESIDE NEAR THE RIGHT REAR ENTRANCE REGION OF A DEPARTING JET AND
THE LEFT EXIT REGION OF AN APPROACHING SPEED MAX BY AFTERNOON. AT
THE SAME TIME...LOW/MID LEVEL WIND FIELDS WILL BE STRENGTHENING...
AND A SURFACE LOW PRESSURE IS EXPECTED TO DEEPEN OVER EASTERN
COLORADO. THIS WOULD PUT A DRYLINE INTO PLAY DEPENDING EXACTLY ON
WHERE THE SURFACE LOW DEEPENS. THINK THE GFS IS OVERDOING THE LOW
LEVEL DRYING OVER NORTHEAST COLORADO...SO AT THIS TIME FAVOR THE
ECMWF/NAM DEPICTION. CAPES ALONG AND AHEAD OF POTENTIAL DRYLINE
WOULD BE CAPABLE OF INCREASING TO 1500-2000 J/KG WITH SUFFICIENT
HEATING AND T/TD OF 68/50. WIND SHEAR WOULD SUPPORT SUPERCELLS
WITH LARGE HAIL AND TORNADO POTENTIAL...BUT ONLY IF WE GET THE
REQUIRED HEATING. WILL CONTINUE TO MONITOR THIS SEVERE POTENTIAL
THROUGH SATURDAY.
BY SUNDAY...AIRMASS IS STILL EXPECTED TO BE UNSTABLE UNDER
GENERAL TROUGHINESS. BOTH WIND SHEAR AND INSTABILITY WOULD BE A
LITTLE WEAKER THOUGH. SEVERE THREAT IS STILL THERE BUT LOWER THAN
SATURDAY. WILL CONTINUE THE FORECAST OF SCATTERED SHOWERS AND
THUNDERSTORMS.
MONDAY THROUGH MOST OF NEXT WEEK WILL FEATURE MORE AFTERNOON AND
EVENING CONVECTION EACH DAY WITH PLENTY OF RESIDUAL MOISTURE.
HOWEVER...TEMPERATURES WILL BE MODERATING AS FLOW ALOFT TURNS
MORE WESTERLY AND WE SHOULD FINALLY SEE MORE SUNSHINE AT LEAST
DURING THE MORNING HOURS. POTENTIAL FOR EMBEDDED DISTURBANCES
THROUGH THIS PERIOD BUT HARD TO TIME THESE RIGHT NOW.
&&
.AVIATION...(FOR THE TAFS THROUGH 00Z FRIDAY LATE AFTERNOON)
ISSUED AT 339 PM MDT THU MAY 21 2015
CLOUD HEIGHTS WILL GRADUALLY COME BACK DOWN TO MARGINAL VFR
CATEGORY THROUGH THE EVENING AS THE UPPER LEVEL DISTURBANCE
APPROACHES THE STATE FROM THE SOUTH. WINDS SHOULD TRANSITION TO
THE SOUTHEASTERLY THROUGH THE EVENING HOURS WHICH WILL HELP HOLD
THE MOIST LOW LEVEL AIRMASS IN PLACE OVER THE DENVER METRO AREA.
AS THE HEAVIEST PART OF THE SYSTEM MOVES OVER DENVER DURING THE
MORNING HOURS...IFR CEILINGS MAY DEVELOP. IMPROVED CONDITIONS ARE
EXPECTED BY LATE MORNING AS THE UPPER DISTURBANCE CLEARS OUT OF
THE STATE. ADDITIONAL SHOWERS ARE POSSIBLE LATE TOMORROW AFTERNOON
AS DAYTIME HEATING BEGINS TO DE-STABILIZE THE MOIST AIRMASS THAT
WILL BE IN PLACE.
&&
.HYDROLOGY...
ISSUED AT 339 PM MDT THU MAY 21 2015
FLOOD WARNINGS CONTINUE FOR THE SOUTH PLATTE FROM CENTRAL WELD
COUNTY INTO WESTERN MORGAN COUNTY. AT THIS TIME...GENERALLY MINOR
FLOODING IS ANTICIPATED WITH WATER LEVELS BELOW LAST WEEKS CREST.
CONTINUED MINOR FLOODING IS STILL ANTICIPATED ON THE CACHE LA
POUDRE IN WESTERN WELD COUNTY THROUGH EARLY NEXT WEEK.
NO APPRECIABLE RAIN HAS FALLEN IN THE PAST 36-48 HOURS SO THE
RIVERS SHOULD CONTINUE A SLOW DECREASE THROUGH THIS EVENING EXCEPT
FOR THE FLOOD CREST MOVING DOWN THE SOUTH PLATTE WHICH WILL MOVE
THROUGH FORT MORGAN AFTER MIDNIGHT.
ANOTHER ORGANIZED SHORTWAVE WILL MOVE THROUGH THE REGION TONIGHT
WITH MORE LIGHT TO MODERATE RAIN AND SOME EMBEDDED
THUNDERSHOWERS. TOTAL LIQUID PRECIPITATION IS EXPECTED TO RANGE
FROM .25 TO .75 INCHES ON THE PLAINS WITH UPWARDS OF AN INCH
POSSIBLE IN THE MOUNTAINS AND HIGHER FOOTHILLS. ALTHOUGH THESE
AMOUNTS DO NOT SEEM LARGE...THE SATURATED GROUND CONDITIONS
SHOULD RESULT IN EFFICIENT RUNOFF. RIVERS AND STREAMS THAT ARE
ALREADY RUNNING HIGH WILL CONTINUE TO DO SO.
SATURDAY WILL HAVE POTENTIAL FOR STRONGER THUNDERSTORMS WITH
HEAVY RAINFALL AND A FLASH FLOOD THREAT. PRECIPITABLE WATER
VALUES NEAR 0.70 TO 0.90 INCH ON THE PLAINS AND ANY STRONGER DEEP
CONVECTION THAT DEVELOPS WOULD SUPPORT POTENTIAL FOR QUICK 1 TO
1.5 INCH RAINFALL AMOUNTS FROM THE ISOLATED STRONGER STORMS. FLASH
FLOOD GUIDANCE CONTINUES TO DROP WITH ADDITIONAL RAINFALL AND SOIL
SATURATION. SUNDAY MAY ALSO SEE SOME THREAT OF LOCALIZED FLASH
FLOODING BUT MOISTURE LEVELS AND INSTABILITY WILL BE LESS THAN
SATURDAY.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 AM MDT FRIDAY FOR COZ034.
&&
$$
SHORT TERM...DANKERS
LONG TERM...BARJENBRUCH
AVIATION...DANKERS
HYDROLOGY...BARJENBRUCH/DANKERS
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
1135 AM CDT THU MAY 21 2015
.UPDATE...
FORECAST REASONING FROM SOUNDING DISCUSSION ALONG WITH
RADAR...MESO-ANALYSIS...AND HRRR MODEL TRENDS ALL SUPPORT RAISING
THE POP TO LIKELY RANGE FOR MUCH OF THE AREA THE REMAINDER OF
TODAY. TEMPERATURES WERE RISING A BIT FASTER AND ALREADY REACHED
THE FORECAST HIGHS. ANOTHER RISE OF A DEGREE OR TWO IS
POSSIBLE...HOWEVER INCREASING SHOWERS AND THUNDERSTORMS AND
ASSOCIATED CLOUD COVER WILL BE CAPPING OFF THE TEMPERATURES AND
CAUSING A GENERAL DOWNTREND AS THE AFTERNOON PROGRESSES. UPDATES
HAVE BEEN SENT. 22/TD
&&
.PREV DISCUSSION... /ISSUED 757 AM CDT THU MAY 21 2015/
..SOUNDING DISCUSSION...
PLENTY OF MOISTURE POOLING AHEAD OF THE WEAK FRONT CURRENTLY
LOCATED OVER NORTHERN LOUISIANA AND SOUTHERN MISSISSIPPI. PW IS
ABOUT 150% OF NORMAL FOR LATE MAY. AN INVERSION FROM THE SURFACE
TO 1000 FEET IS CAPPING THE ATMOSPHERE NOW...BUT WILL MIX OUT
WITH DAYTIME HEATING. PLENTY OF INSTABILITY WITH MLCAPE AROUND
1900 J/KG WITH ML LI OF -6 AND A 500MB TEMPERATURE OF -10C. WITH
THIS INSTABILITY...GOOD MOISTURE...AND THE FRONT AND ANY SEA
BREEZE BOUNDARIES BEING LIFTING MECHANISMS...STRONG TO PERHAPS
SEVERE STORMS WILL BE POSSIBLE TODAY. MAIN CONCERN WOULD BE STRONG
WIND GUSTS WITH A LESSER CHANCE OF HAIL GIVEN HIGH FREEZING LEVEL
AROUND 13700 FEET AND WET BULB ZERO ABOUT 2000 LESS THAN THAT.
THERE IS NOT MUCH IN THE WAY OF DIRECTIONAL WIND SHEAR ON THE
CURRENT SOUNDING WITH ALL WINDS HAVE A WESTERLY COMPONENT. BUT AS
THE FRONT NEARS MAY GET A BIT MORE DIRECTIONAL SHEAR. ONE LAST
THING TO MENTION IS WE MAY SEE A FEW THUNDERSTORMS DEVELOP AHEAD
OF THE FRONT WITH A CONVECTIVE TEMPERATURE CALCULATED AT
82F. CURRENT FORECAST HAS US REACHING 82F AROUND 16-17Z AND 11Z
HRRR HAS PRECIPITATION FORMING AROUND THEN TOO.
12Z BALLOON INFO: NO ISSUES WITH THE FLIGHT THAT LASTED 94 MINUTES
AND ASCENDED TO A HEIGHT OF 20.4 MILES ABOVE THE GROUND. THE
BALLOON BURST 21 MILES DOWNRANGE FROM THE OFFICE NEAR ANSLEY.
ANSORGE
PREV DISCUSSION... /ISSUED 430 AM CDT THU MAY 21 2015/
SYNOPSIS...
LATEST SURFACE ANALYSIS SHOWED A 1011MB LOW OVER WESTERN TENNESSEE
WITH A FRONTAL BOUNDARY EXTENDING SOUTHWEST TO WEST CENTRAL
ALABAMA TO WEST CENTRAL MISSISSIPPI TO WEST CENTRAL LOUISIANA.
A 1024MB HIGH WAS LOCATED OVER NEBRASKA/KANSAS. UPPER AIR
ANALYSIS SHOWED A HIGH OVER MEXICO...DISTURBANCE RIDING ON TOP OF THE
RIDGE OVER TEXAS AND A POSITIVELY TILTED TROUGH FROM GREAT LAKES
TO IOWA. IR SHOWED CLOUD COOLING AND SEVERAL THUNDERSTORM COMPLEX
EAST OF THE BIG BEND TO NORTH CENTRAL TEXAS. RADAR REVEALED
ISOLATED CONVECTION ALONG THE FRONT OVER SOUTHERN MISSISSIPPI AND
EAST CENTRAL LOUISIANA.
DISCUSSION...
FRONTAL BOUNDARY WILL CONTINUE TO PUSH SOUTH INTO THE FORECAST
AREA TODAY. SURFACE HEATING WILL INCREASE INSTABILITY AND SURFACE
CONVERGENCE WILL YIELD SCATTERED CONVECTION TODAY. WITH THE
FRONTAL BOUNDARY PUSHING SOUTH THROUGH THE AREA TONIGHT...THE
THREAT OF CONVECTION WILL CONTINUE OVERNIGHT. UPPER LEVEL TROUGH
UP NORTH WILL SWING SOUTH ... GREAT LAKES AND MID ATLANTIC
REGIONS. SURFACE HIGH ON THE PLAINS WILL PRESS SOUTHEAST OVER THE
MID SOUTH THROUGH FRIDAY AND DRY AIR WILL FILTER IN AS EARLY AS
THIS AFTERNOON ACROSS THE NORTH ZONES.
THE FRONTAL BOUNDARY IS EXPECTED TO PUSH SOUTH INTO THE CENTRAL
GULF COAST REGION TONIGHT AND LINGERS ACROSS THE AREA ON FRIDAY
BEFORE BECOMING DIFFUSE ON SATURDAY. HIGH PRESSURE WILL SETTLE
OVER THE EAST AND SOUTHERLY FLOW DEVELOP OVER THE LOWER
MISSISSIPPI VALLEY AND FORECAST AREA SATURDAY AFTERNOON. A
BUILDING UPPER LEVEL RIDGE OVER THE CENTRAL U.S AT THE END OF WEEK
WILL TRAVERSE INTO THE EASTERN CONUS OVER THE WEEKEND. THIS UPPER
LEVEL RIDGE ALONG WITH OVERALL DRIER AIR IN THE ATMOSPHERIC COLUMN
SHOULD HAMPER MOST CONVECTION ON SATURDAY...ISOLATED FOR WEST
ZONES. RAIN CHANCES WILL START TO GO UP AGAIN ON SUNDAY AS THE
UPPER RIDGE AXIS SHIFTS TO THE EAST OF THE REGION AND DISTURBANCES
IN THE SOUTHWEST FLOW ALOFT AHEAD OF A WESTERN CONUS SYSTEM BEGIN
TO IMPACT THE REGION. THIS PATTERN WILL CONTINUE THROUGH THE EARLY
PART OF NEXT WEEK WITH DAILY CHANCES FOR SCATTERED CONVECTION.
AVIATION...
FOG SHOULD ONLY AFFECT THE HOUMA TERMINAL THIS MORNING. CEILINGS
SHOULD STAY ABOVE 015 THIS MORNING AS WELL. WILL SHOW VCTS FOR TODAY
AT ALL SITES. IT LOOKS LIKE THERE WILL BE TWO WAVES OF SH/TS...ONE
DURING THE MORNING AS THE BOUNDARY SINKS SOUTHWARD THEN AGAIN IN THE
AFTERNOON AS HEATING AND BOTH THE FRONTAL BOUNDARY AND C-BRZ
BOUNDARIES BEGIN TO ENHANCE ACTIVITY DURING THE AFTERNOON AND EARLY
EVENING. NOT EXPECTING TO SEE ANY LARGE RESTRICTIONS IN VIS
OVERNIGHT AND CEILINGS SHOULD STAY AROUND 020 FOR THE MOST PART.
MARINE...LIGHT WIND REGIME EXPECTED TO PERSIST TODAY BUT STILL
LOOKS LIKE A WEAK NOCTURNAL JET OVER THE MS SOUND AND JUST TO THE
SOUTH WILL DEVELOP THE NEXT FEW NIGHTS CAUSING WINDS TO STRENGTHEN
IN THESE AREAS TO NEAR OR JUST OVER 10 KTS. HIGH PRESSURE SLIDES
THROUGH THE AREA TODAY/FRIDAY AS A WEAK FRONT TRIES TO PUSH INTO THE
COASTAL WATERS. HIGH PRESSURE WILL QUICKLY SHIFT EAST AND MODERATE
ONSHORE FLOW WILL DEVELOP OVER THE WEEKEND.
DECISION SUPPORT...
DSS CODE...GREEN...UPGRADE TO YELLOW POSSIBLE THIS AFTERNOON.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...MONITORING STRONG TO SEVERE THUNDERSTORM POTENTIAL
TODAY.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT
TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 82 62 81 65 / 60 20 40 20
BTR 86 65 82 68 / 60 30 40 20
ASD 86 67 80 68 / 60 30 40 20
MSY 86 73 84 73 / 60 30 40 20
GPT 86 68 80 71 / 50 30 40 20
PQL 86 66 81 68 / 50 30 40 10
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
116 PM EDT THU MAY 21 2015
.SYNOPSIS...
HIGH PRESSURE TO THE SOUTH WILL MOVE EAST TODAY. ANOTHER COLD
FRONT WILL APPROACH FROM CUBIC LATER TONIGHT AND MOVING THROUGH
THE REGION ON FRIDAYS WITH SHOWERS FOR THE REGION. CONDITIONS
WILL REMAIN UNSETTLED INTO STUART AN UPPER LOW MOVES ACROSS THE
REGION FROM CANAD.
&&
.NEAR TERM /THROUGH TONIGHT/...
115 PM UPDATE...NO SIGNFICANT CHANGES NEEDED WITH THIS UPDATE.
TWEAKED TEMPERATURES UP A COUPLE OF DEGREES AS MANY LOCATIONS WERE
ALREADY DRAWING CLOSE TO THEIR FORECASTED HIGH. ALSO ADDED
ISOLATED SHOWERS TO THIS AFTERNOON`S FORECAST FOR THE BANGOR AREA,
AS WE`RE STARTING TO SEE DECENT CUMULUS POPPING UP AND THE HRRR
CONTINUES TO SHOW THAT SHOWERS ARE GOING TO DEVELOP. NO OTHER
CHANGES WERE NEEDED.
PREVIOUS DISCUSSION...CLOUDS WILL INCREASE TODAY AS ANOTHER
FRONTAL BOUNDARY SLIDES TOWARDS THE REGION. AN UPPER DISTURBANCE
SEEN IN WATER VAPOR IMAGERY IS FORECAST BY THE NAM AND GFS TO
SWINGS ACROSS THE REGION. LLVL CONVERGENCE IN THE WESTERN AREAS
COMBINED W/SOME WEAK MID LEVEL FORCING COULD ALLOW FOR A FEW
SHOWERS LATER THIS AFTERNOON. DECIDED TO TAKE A CONSENSUS
APCH(NAM/GFS AND HRRR 3KM) AND BROUGHT 20-30% POPS INTO THE WNW
AREAS A BIT EARLIER THAN PREVIOUSLY FORECAST. THE REST OF THE CWA
WILL REMAIN DRY. DAYTIME TEMPERATURES ARE FORECAST TO BE IN THE
LOW/MID 60S NORTH AND WEST TO THE UPPER 60S CENTRAL AND DOWNEAST.
A WAVE OF LOW PRESSURE OVER SOUTHERN QUEBEC IS EXPECTED TO DEVELOP
ON THE FRONTAL BOUNDARY AND MOVE NE ACROSS NW MAINE. SHOWERS ARE
FORECAST TO MOVE INTO NORTHERN AND WESTERN AREAS OVERNIGHT. RAINFALL
AMOUNTS WILL BE LIGHT(<.05"). TEMPERATURES ARE EXPECTED TO BE
WARMER THAN THEY WERE THIS MORNING HOLDING IN THE 40S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
LOW PRESSURE WILL TRACK EAST OF THE GULF OF MAINE DURING FRIDAY.
STEADY RAIN ASSOCIATED WITH THIS LOW SHOULD REMAIN TO THE EAST OF
THE STATE. HOWEVER, SHOWERS ASSOCIATED WITH AN APPROACHING UPPER
LOW FROM THE NORTHWEST AND ATTENDANT COLD FRONT CAN BE EXPECTED ON
FRIDAY. THE COLD FRONT WILL MOVE EAST OF THE DOWN EAST COAST EARLY
FRIDAY EVENING WITH ANY LINGERING SHOWERS PUSHING OFFSHORE.
NORTHWEST WINDS BEHIND THE FRONT WILL USHER IN COLDER AIR FRIDAY
NIGHT. 850MB TEMPS FALL TO AROUND -5C BY 12Z SATURDAY WITH 925 MB
TEMPS DOWN TO AROUND 0C. WITH THE COLD AIR ALOFT WE COULD SEE A
FEW SNOW SHOWERS ACROSS NORTHERN AREAS AS THE 500 MB LOW TRACKS
ACROSS THE REGION. EXPECT GUSTY NORTHWEST WINDS ON SATURDAY AS LOW
PRESSURE REMAINS TO OUR NORTHEAST AND A RIDGE OF HIGH PRESSURE
BUILDS EAST. SKIES WILL BE PARTLY SUNNY ACROSS NORTHERN AND
CENTRAL AREAS WITH THE CHANCE OF A SHOWER AND PARTLY TO MOSTLY
SUNNY SKIES DOWN EAST. HIGHS ON SATURDAY WILL BE BELOW NORMAL FOR
THIS TIME OF YEAR WITH HIGHS EXPECTED TO RANGE FROM THE MID TO
UPPER 50S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
A SHORT WAVE IS EXPECTED TO APPROACH FROM THE NORTHWEST SATURDAY
EVENING AND CROSS THE REGION LATER SATURDAY NIGHT AND INTO EARLY
SUNDAY. EXPECT PARTLY TO MOSTLY CLOUDY SKIES SATURDAY NIGHT WITH
THE CHANCE FOR A SHOWER MAINLY ACROSS NORTHERN AREAS. HIGHS ON
SUNDAY WILL RANGE FROM THE LOW TO MID 60S NORTH AND CENTRAL AND
UPPER 60S TO NEAR 70 DOWN EAST. EXPECT MAINLY CLEAR SKIES SUNDAY
NIGHT FOLLOWED BY A MAINLY SUNNY AND WARM MEMORIAL DAY. CLOUDS
WILL INCREASE MONDAY NIGHT WITH A FEW SHOWERS EXPECTED AS WARM
FRONT LIFTS NORTHEAST TOWARD THE REGION. EXPECT A CHANCE FOR
SHOWERS AND PERHAPS AN ISLD TSTM TUESDAY INTO WEDNESDAY IN ADVANCE
OF A SLOW MOVING COLD FRONT FROM THE NORTHWEST. TEMPERATURES WILL
AVERAGE ABOVE NORMAL THROUGH MID WEEK.
&&
.AVIATION /17Z THURSDAY THROUGH MONDAY/...
NEAR TERM: VFR CONDITIONS THROUGH TONIGHT FOR ALL TERMINALS.
SHORT TERM: VFR BUT MVFR IN ANY RAIN SHOWERS FRIDAY AND RAIN/SNOW
SHOWERS FRIDAY NIGHT. VFR CONDITIONS EXPECTED SATURDAY THROUGH
MONDAY.
&&
.MARINE...
NEAR TERM: NO HEADLINES THROUGH TONIGHT. SEAS ARE TO REMAIN 2 TO 3
FT INTO TONIGHT W/WINDS 10 TO 15 KTS.
SHORT TERM: WINDS/SEAS MAY REACH SCA LEVELS FRIDAY NIGHT AND
SATURDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HASTINGS/HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HASTINGS/HEWITT/DUDA
MARINE...HASTINGS/HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
329 PM EDT THU MAY 21 2015
LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE
.SYNOPSIS...
ISSUED AT 329 PM EDT THU MAY 21 2015
SCATTERED RAIN SHOWERS WILL MOVE SOUTH THROUGH THE AREA WITH A COLD
FRONT. BEHIND THIS FRONT...HIGH TEMPERATURES FRIDAY WILL BE AROUND
60...WHICH IS ABOUT 10 DEGREES BELOW NORMAL THIS TIME OF YEAR.
PATCHY FROST IS POSSIBLE OVER PARTS OF CENTRAL LOWER MICHIGAN FRIDAY
MORNING. THERE IS EVEN BETTER POTENTIAL FOR FROST SATURDAY MORNING.
RAIN CHANCES RETURN SUNDAY AFTERNOON WITH A WARMER AND WETTER
PATTERN LASTING WELL INTO NEXT WEEK.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 329 PM EDT THU MAY 21 2015
SCATTERED SHOWERS ARE POSSIBLE THIS EVENING. COOLER THAN NORMAL
TEMPERATURES WILL PERSIST THROUGH FRIDAY NIGHT. FROST FORMATION IS
POSSIBLE TONIGHT MAINLY ACROSS CENTRAL LOWER MICHIGAN. WIDESPREAD
AREAS OF FROST ARE MORE LIKELY LATE FRIDAY NIGHT INTO SATURDAY
MORNING.
A WEAK COLD FRONT WILL DROP SOUTH THROUGH LOWER MICHIGAN THIS
EVENING AS AN UPPER LEVEL SHORTWAVE PROPAGATES OVER THE LOWER GREAT
LAKES REGION. MOISTURE IS CONFINED TO THE MID LEVELS WITH CLOUD
BASES AROUND 9K FEET. SFC DEWPOINTS ARE ONLY IN THE 30S TO LOWER
40S. ALL THIS SHOULD RESULT IN ISOLATED TO SCATTERED LIGHT RAIN
SHOWERS...CONFIRMED BY THE LAST SEVERAL RUNS OF THE RAP AND HRRR. A
SIMILAR AIRMASS YESTERDAY EVENING RESULTED IN A RAIN/SLEET MIX
MAINLY IN THE CHICAGO AREA. BUT PRECIP THIS EVENING WILL LIKELY NOT
BE HEAVY ENOUGH TO CAUSE SIGNIFICANT WET-BULBING.
MID-LEVEL CLOUDS WILL START TO CLEAR OUT FROM NORTH TO SOUTH LATE
TONIGHT AND WINDS WILL SUBSIDE AS THEY VEER NORTHERLY BEHIND THE SFC
FRONT. THIS SHOULD ALLOW DECENT RADIATIONAL COOLING CONDITIONS TO
SET UP AFTER MIDNIGHT. FROST WILL BE POSSIBLE ACROSS CENTRAL LOWER
MICHIGAN.
ANOTHER COOL DAY IS EXPECTED ON FRIDAY WITH NORTHWEST FLOW AT THE
SURFACE. BUT PLENTY OF SUNSHINE IS EXPECTED AS A SURFACE HIGH BUILDS
IN. UPPER RIDGING WILL CONTINUE TO BUILD IN THROUGH SATURDAY NIGHT
AS THE SFC HIGH SLIDES OFF TO THE SOUTHEAST. FAIR WEATHER IS
EXPECTED FRIDAY NIGHT THROUGH SATURDAY NIGHT...BUT THIS SHOULD ALLOW
GOOD FROST CONDITIONS TO SET UP FRIDAY NIGHT INTO SATURDAY MORNING.
WITH CLEAR SKIES AND LIGHT WINDS...LOWS WILL LIKELY DROP INTO THE
LOW TO MID 30S ACROSS MUCH OF THE FORECAST AREA. SOUTHWEST RETURN
FLOW FINALLY SETS UP SATURDAY...ALONG WITH PLENTY OF SUNSHINE AND
HIGHS IN THE LOWER 70S.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 329 PM EDT THU MAY 21 2015
THE MAIN STORY IN THE LONG TERM PERIOD IS THAT WE WILL FINALLY SEE
WARMER TEMPERATURES AS THE PERSISTENT HUDSON BAY UPPER LOW RETREATS
AND WE GET INTO DEEP SOUTHWEST FLOW. HIGHS IN THE 70S ARE LIKELY
AWAY FROM LK MI... WITH PERHAPS 80 DEGREES AND NOTICEABLY MORE HUMID
FROM MONDAY ON.
PROLONGED WARM ADVECTION PATTERN WITH A FLOW OFF THE GULF AND A
QUASI STATIONARY FRONTAL BOUNDARY WILL LIKELY LEAD TO ROUNDS OF
SHOWERS AND POSSIBLE TSTMS. HOWEVER THE TIMING/LOCATION/DURATION OF
CONVECTIVE EPISODES AND DAILY POSITION OF THE SFC FRONT IS LOW
CONFIDENCE AT THIS TIME. CURRENTLY WE HAVE THE HIGHEST POPS ON
SUNDAY NIGHT AND MONDAY WHICH IS WHEN THE SFC WARM FRONT IS LIFTING
NORTH THROUGH THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 153 PM EDT THU MAY 21 2015
VFR WEATHER WILL CONTINUE THE NEXT 24 HOURS. THE AREA OF CLOUDS
CURRENTLY OVERHEAD WITH BASES AT OR ABOVE 12,000 FT WILL MOVE OUT
THIS AFTERNOON... AND WILL BE FOLLOWED BY A NARROW BAND OF CLOUDS
DROPPING DOWN FROM THE NORTH THIS EVENING. THESE CLOUDS WILL HAVE
BASES BETWEEN 6000 AND 10,000 FT AND MAY PRODUCE A FEW LIGHT
RAIN SHOWERS OR SPRINKLES BUT NO REDUCTIONS TO VSBYS. CLEAR SKIES
WILL FOLLOW BEHIND THIS BAND OF CLOUDS FOR LATER NIGHT AND FRIDAY
MORNING. A PERIOD OF GUSTY WEST WINDS IS EXPECTED THROUGH 00Z
BEFORE DIMINISHING AND TURNING NORTHERLY LATER TONIGHT.
&&
.MARINE...
ISSUED AT 329 PM EDT THU MAY 21 2015
BREEZY WESTERLY WINDS WILL CONTINUE THIS AFTERNOON WITH WAVES IN
THE 1 TO 3 FOOT RANGE. SCATTERED LIGHT SHOWERS WILL BE POSSIBLE
LATE THIS AFTERNOON AND EVENING. WINDS ARE EXPECTED TO SUBSIDE
AND VEER NORTHERLY BEHIND A WEAK COLD FRONT OVERNIGHT. WAVES WILL
BE 1 TO 2 FEET. NORTHERLY WINDS OF 5 TO 10 KNOTS ON FRIDAY WITH
WAVES AROUND 1 FOOT. FRIDAY WILL FEATURE PLENTY OF SUNSHINE BUT
STILL COOLER THAN NORMAL TEMPS. WINDS WILL TURN SOUTHWESTERLY ON
SATURDAY IN THE 5 TO 15 KNOT RANGE WITH WAVES AROUND 1 FOOT.
&&
.HYDROLOGY...
ISSUED AT 1240 PM EDT THU MAY 21 2015
NO CONCERNS THROUGH THE WEEKEND. PRECIPITATION THAT COULD AFFECT
MAINSTEM RIVERS IS NOT EXPECTED UNTIL LATE SUNDAY...WHICH MARKS THE
START OF A WETTER PATTERN LASTING WELL INTO THE COMING WORK WEEK.
NATIONAL GUIDANCE ADVERTISES UNIFORM RAINFALL TOTALS OF 1-1.5
INCHES ACROSS THE AREA THROUGH THURSDAY MORNING. GIVEN THAT BASE
FLOWS ARE NEAR OR BELOW NORMAL AND THAT RAIN SHOULD BE SPREAD OUT
OVER TIME...WE EXPECT FAIRLY GENTLE RISES WILL BE UNDERWAY BY THE
MIDDLE OF NEXT WEEK.
THAT SAID...FORECASTING CONVECTIVE RAINFALL THIS FAR OUT IS
HIGHLY UNCERTAIN SO THERE STILL REMAINS A FAIRLY WIDE RANGE OF
POSSIBILITIES FOR RAINFALL AND RIVER RESPONSES AT THIS POINT.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...FROST ADVISORY FROM 3 AM TO 9 AM EDT FRIDAY FOR MIZ037>040-
043>046.
LM...NONE.
&&
$$
SYNOPSIS...TJT
SHORT TERM...EBW
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...TJT
MARINE...EBW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
606 PM EDT THU MAY 21 2015
.SYNOPSIS...
LOW PRESSURE ALONG A COLD FRONT WILL SHIFT OFF THE COAST OVERNIGHT
MOVING THE COLD FRONT OFF THE COAST. COOLER HIGH PRESSURE WILL
BUILD INTO REGION FRIDAY AND CONTINUE INTO THE WEEKEND. AS THE
HIGH PRESSURE SHIFTS OFF THE COAST BY THE MIDDLE OF NEXT WEEK
HIGHER HUMDITIES WILL RETURN TO THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 600 PM THURSDAY..SEVERE THUNDERSTORM WATCH 193 HAS BEEN
CANCELLED FOR THE ENTIRE AREA. RELEVANT PORTION OF PREVIOUS
DISCUSSION FROM 3 PM FOLLOWS BELOW:
DRY AIR WILL ADVECT IN BEHIND THIS TROUGH WITH DEWPOINT TEMPS
ALREADY DROPPING WEST OF I95 FROM NEAR 70 DOWN CLOSER TO 60 BY MID
AFTERNOON. TEMPS WILL BE SLOWER TO DROP IN CONTINUED SUNSHINE
THROUGH THE NEXT SEVERAL HOURS.
THEN THE MAIN H5 TROUGH EXTENDING DOWN FROM GREAT LAKES WILL
PUSH A COLD FRONT SOUTH AS IT MOVES EAST OVERNIGHT. SFC WINDS WILL
VEER AROUND QUITE ABRUPTLY AS THIS FRONT MOVES DOWN FROM THE
NORTH LATE EVENING INTO THE OVERNIGHT HOURS. A COUPLE OF THE MESO
MODELS WERE SHOWING A COUPLE OF SHWRS AS THIS FRONT MOVES THROUGH
BUT FOR NOW WILL KEEP POPS OUT OF FORECAST AFTER THIS INITIAL LINE
PASSES WITH DRIER AND RELATIVELY COOLER AIR MOVING IN. 850 TEMPS
WILL DROP FROM NEAR 16 C LATE THIS AFTERNOON DOWN TO 9C BY
MORNING. OVERALL EXPECT A COMPLETE CHANGE IN AIR MASS WITH WARMER
MORE HUMID AIR MASS TRANSITIONING TO A MORE SEASONABLE RELATIVELY
DRIER AIR MASS. TEMPS TONIGHT WILL BE SLOWER TO DROP INITIALLY BUT
ONCE FRONT DROPS SOUTH...TEMPS AND DEWPOINTS WILL FALL MORE
RAPIDLY WITH TEMPS DOWN NEAR 60 BY DAYBREAK.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...AS THE FRONT EXITS THE FORECAST REGION...COOLER
DRY HIGH PRESSURE WILL MOVE IN. GFS AND NAM ARE SHOWING THE
PRECIPITABLE WATER VALUES FALLING TO A RANGE OF 0.5 TO 1 INCHES.
THE HIGH PRESSURE CENTER WILL STAY TO THE NORTH DURING THIS PERIOD.
NO PRECIPITATION IS EXPECTED THROUGH THIS PERIOD AND MAXIMUM
TEMPERATURES ARE EXPECTED TO BE IN THE UPPER 70S FRIDAY AND AROUND
80 ON SATURDAY. LOWS EACH NIGHT SHOULD BOTTOM OUT IN THE MIDDLE
50S FRIDAY NIGHT AND THE UPPER 50S ON SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...SURFACE HIGH PRESSURE WILL BE CENTERED JUST
TO THE NORTH OF THE AREA AND WILL SHIFT OFF THE COAST BY THE
BEGINNING OF NEXT WEEK. THE AREA WILL SEE A RETURN OF ONSHORE
FLOW...A RETURN TO HIGHER HUMIDITIES...AND A WARM UP IN TEMPERATURES.
ALOFT A RIDGE STUBBORNLY HOLDS ON THROUGH ALMOST THURSDAY SO THE
CHANCES OF PRECIPITATION WILL BE MINIMAL THROUGH AT LEAST EARLY
TUESDAY AND MAYBE AN ISOLATED CHANCE OF A DIURNAL SHOWERS OR
THUNDERSTORMS BY LATE TUESDAY THROUGH THURSDAY. MAXIMUM TEMPERATURES
WILL REBOUND TO AROUND 90 BY TUESDAY AND REMAIN AT THOSE LEVELS
THROUGH THURSDAY. MINIMUM TEMPERATURES WILL BE IN THE LOWER 60S
ON SUNDAY NIGHT AND WILL SLOWLY RISE INTO THE UPPER 60S BY
WEDNESDAY NIGHT.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
AS OF 18Z...THE HRRR MODEL CONTINUES TO SHOW MODERATE CONVECTION
OVER NORTHERN TERMINALS THROUGH THE AFTERNOON HOURS. THIS AGREES
WITH THE LATEST 12Z RUN OF THE NAM. KLBT WILL BE UNDER THE GUN
19-21Z WITH KILM 20-24Z. AT KCRE MOIST ONSHORE FLOW COULD RESULT
IN TEMPO IFR MARINE STRATUS CIGS THROUGH 20Z...POSSIBLY A FEW
HOURS LATER IF WINDS DO NOT SHIFT FURTHER TO THE SW LATER THIS
AFTERNOON. CONVECTION SHOULD MOVE OFF EARLY THIS EVENING. SW-W
WINDS WILL SHIFT TO THE NORTH TONIGHT AS LOW PRESSURE PULLS OFF TO
THE NE. MUCH DRIER AIR WILL USHER IN OVERNIGHT...WITH VFR CONDITIONS
EXPECTED FOR FRIDAY WITH SCATTERED SKIES.
EXTENDED OUTLOOK...VFR. MORNING FOG POSSIBLE MONDAY AND TUESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/... AS OF 600 PM THURSDAY...SEVERE
THUNDERSTORM WATCH 193 HAS BEEN CANCELLED. RELEVANT PORTION OF
PREVIOUS DISCUSSION BELOW:
SW WINDS 15 TO 20 KT AHEAD OF A COASTAL TROUGH...WILL SHIFT TO THE W-
NW THROUGH THIS EVENING AS IT SHIFTS OFF SHORE. THE ASSOCIATED COLD
FRONT WILL GET PUSHED SOUTH TONIGHT WITH A MORE ABRUPT SHIFT OF
WINDS TO THE N LATE THIS EVENING INTO THE OVERNIGHT HOURS. THIS WILL
PRODUCE A NORTHERLY SURGE WITH WINDS INCREASING TO AROUND 20 KT LATE
TONIGHT. MODELS CONTINUE TO SHOW WINDS AND SEAS REACHING NEAR SMALL
CRAFT SHOULD EXERCISE CAUTION THRESHOLDS. SEAS 2 TO 4 FT THROUGH
THIS EVENING INTO OVERNIGHT MAY SEE SOME 5 FOOTERS OVERNIGHT ACROSS
THE OUTERMOST WATERS.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...A COLD FRONT WILL HAVE PUSHED EAST OF THE
WATERS AND HIGH PRESSURE WILL BUILD OVER THE WATERS. WINDS WILL
BE FROM THE NORTH AT 15 TO 20 KNOTS ON FRIDAY MORNING AND WILL
SLOWLY WEAKEN TO 10 TO 15 KTS BY THE OF END FRIDAY AND REMAIN AT
THESE SPEEDS. WINDS WILL BEGIN THE DAY FROM THE NORTH AND WILL
VEER TO THE EAST BY SATURDAY. SEA HEIGHTS WILL START OUT AT 2 TO 4
FEET EARLY FRIDAY AND WILL SETTLE OUT AT 2 TO 3 FEET THROUGH
SATURDAY NIGHT.
LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 3 PM THURSDAY...HIGH PRESSURE WILL RULE THE COASTAL WATERS
WITH SOUTHEAST WINDS OF 10 KNOTS SLOWLY SHIFTING TO THE SOUTH AT
10 KNOTS BY TUESDAY. SEAS WILL REMAIN AT 2 TO 3 FEET FOR THE
ENTIRE FORECAST PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RGZ/JDW
SHORT TERM...HAWKINS
LONG TERM...HAWKINS
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
343 PM EDT THU MAY 21 2015
.SYNOPSIS...
LOW PRESSURE ALONG A COLD FRONT WILL SHIFT OFF THE COAST OVERNIGHT
MOVING THE COLD FRONT OFF THE COAST. COOLER HIGH PRESSURE WILL
BUILD INTO REGION FRIDAY AND CONTINUE INTO THE WEEKEND. AS THE
HIGH PRESSURE SHIFTS OFF THE COAST BY THE MIDDLE OF NEXT WEEK
HIGHER HUMDITIES WILL RETURN TO THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/... AS OF 300 PM THURSDAY...SEVERE
THUNDERSTORM WATCH 193 REMAINS IN EFFECT FOR SOUTHEAST NC THROUGH 8
PM. TROUGH EXTENDING FROM LOW PRESSURE AT THE SURFACE ALONG WITH
SHORTWAVE IN THE MID LEVELS WILL CONTINUE TO COMBINE WITH HEATING OF
THE DAY AND MOISTURE RICH AIR TO TO TRIGGER SHOWERS AND
THUNDERSTORMS ACROSS THE EASTERN CAROLINAS THIS AFTERNOON. THESE
THUNDERSTORMS MAY CONTAIN DAMAGING WINDS AND POSSIBLE HAIL. CAN NOT
RULE OUT AN ISOLATED TORNADO. A FAIRLY DECENT LINE SEGMENT DEVELOPED
JUST WEST OF ILM CWA EXTENDING INTO MARLBORO AND DARLINGTON COUNTIES
EARLY THIS AFTERNOON. THIS LINE ALONG I95 MID AFTERNOON WILL MOVE
EAST TOWARD THE COAST. IT REMAINS ALIGNED ALONG STEEP MOISTURE
GRADIENT AS EVIDENT ON WATER VAPOR IMAGERY AS WELL AS BEST
CONVERGENCE ALONG SFC TROUGH EXTENDING FROM LOW. DRY AIR WILL PUNCH
IN FROM THE WEST PROVIDING SOME DECENT DOWNDRAFT POTENTIAL WITH
THESE STORMS.
THIS TROUGH OF LOW PRESSURE WITH LINE OF CONVECTION WAS RUNNING
DOWN ALONG I95 MID AFTERNOON AND WILL CONTINUE EAST WITH LOW
BECOMES ELONGATED DOWN THE EAST COAST THROUGH EARLY THIS EVENING.
DRY AIR WILL ADVECT IN BEHIND THIS TROUGH WITH DEWPOINT TEMPS
ALREADY DROPPING WEST OF I95 FROM NEAR 70 DOWN CLOSER TO 60 BY MID
AFTERNOON. TEMPS WILL BE SLOWER TO DROP IN CONTINUED SUNSHINE
THROUGH THE NEXT SEVERAL HOURS.
THEN THE MAIN H5 TROUGH EXTENDING DOWN FROM GREAT LAKES WILL
PUSH A COLD FRONT SOUTH AS IT MOVES EAST OVERNIGHT. SFC WINDS WILL
VEER AROUND QUITE ABRUPTLY AS THIS FRONT MOVES DOWN FROM THE
NORTH LATE EVENING INTO THE OVERNIGHT HOURS. A COUPLE OF THE MESO
MODELS WERE SHOWING A COUPLE OF SHWRS AS THIS FRONT MOVES THROUGH
BUT FOR NOW WILL KEEP POPS OUT OF FORECAST AFTER THIS INITIAL LINE
PASSES WITH DRIER AND RELATIVELY COOLER AIR MOVING IN. 850 TEMPS
WILL DROP FROM NEAR 16 C LATE THIS AFTERNOON DOWN TO 9C BY
MORNING. OVERALL EXPECT A COMPLETE CHANGE IN AIR MASS WITH WARMER
MORE HUMID AIR MASS TRANSITIONING TO A MORE SEASONABLE RELATIVELY
DRIER AIR MASS. TEMPS TONIGHT WILL BE SLOWER TO DROP INITIALLY BUT
ONCE FRONT DROPS SOUTH...TEMPS AND DEWPOINTS WILL FALL MORE
RAPIDLY WITH TEMPS DOWN NEAR 60 BY DAYBREAK.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...AS THE FRONT EXITS THE FORECAST REGION...COOLER
DRY HIGH PRESSURE WILL MOVE IN. GFS AND NAM ARE SHOWING THE
PRECIPITABLE WATER VALUES FALLING TO A RANGE OF 0.5 TO 1 INCHES.
THE HIGH PRESSURE CENTER WILL STAY TO THE NORTH DURING THIS PERIOD.
NO PRECIPITATION IS EXPECTED THROUGH THIS PERIOD AND MAXIMUM
TEMPERATURES ARE EXPECTED TO BE IN THE UPPER 70S FRIDAY AND AROUND
80 ON SATURDAY. LOWS EACH NIGHT SHOULD BOTTOM OUT IN THE MIDDLE
50S FRIDAY NIGHT AND THE UPPER 50S ON SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...SURFACE HIGH PRESSURE WILL BE CENTERED JUST
TO THE NORTH OF THE AREA AND WILL SHIFT OFF THE COAST BY THE
BEGINNING OF NEXT WEEK. THE AREA WILL SEE A RETURN OF ONSHORE
FLOW...A RETURN TO HIGHER HUMIDITIES...AND A WARM UP IN TEMPERATURES.
ALOFT A RIDGE STUBBORNLY HOLDS ON THROUGH ALMOST THURSDAY SO THE
CHANCES OF PRECIPITATION WILL BE MINIMAL THROUGH AT LEAST EARLY
TUESDAY AND MAYBE AN ISOLATED CHANCE OF A DIURNAL SHOWERS OR
THUNDERSTORMS BY LATE TUESDAY THROUGH THURSDAY. MAXIMUM TEMPERATURES
WILL REBOUND TO AROUND 90 BY TUESDAY AND REMAIN AT THOSE LEVELS
THROUGH THURSDAY. MINIMUM TEMPERATURES WILL BE IN THE LOWER 60S
ON SUNDAY NIGHT AND WILL SLOWLY RISE INTO THE UPPER 60S BY
WEDNESDAY NIGHT.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
AS OF 18Z...THE HRRR MODEL CONTINUES TO SHOW MODERATE CONVECTION
OVER NORTHERN TERMINALS THROUGH THE AFTERNOON HOURS. THIS AGREES
WITH THE LATEST 12Z RUN OF THE NAM. KLBT WILL BE UNDER THE GUN
19-21Z WITH KILM 20-24Z. AT KCRE MOIST ONSHORE FLOW COULD RESULT
IN TEMPO IFR MARINE STRATUS CIGS THROUGH 20Z...POSSIBLY A FEW
HOURS LATER IF WINDS DO NOT SHIFT FURTHER TO THE SW LATER THIS
AFTERNOON. CONVECTION SHOULD MOVE OFF EARLY THIS EVENING. SW-W
WINDS WILL SHIFT TO THE NORTH TONIGHT AS LOW PRESSURE PULLS OFF TO
THE NE. MUCH DRIER AIR WILL USHER IN OVERNIGHT...WITH VFR CONDITIONS
EXPECTED FOR FRIDAY WITH SCATTERED SKIES.
EXTENDED OUTLOOK...VFR. MORNING FOG POSSIBLE MONDAY AND TUESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM THURSDAY...SEVERE THUNDERSTORM WATCH 193 HAS BEEN
ISSUED FOR SOUTHEAST NC INTO THE LOCAL COASTAL WATERS NORTH OF
CAPE FEAR THROUGH 8 PM. SW WINDS 15 TO 20 KT AHEAD OF A COASTAL
TROUGH...WILL SHIFT TO THE W-NW THROUGH THIS EVENING AS IT SHIFTS
OFF SHORE. THE ASSOCIATED COLD FRONT WILL GET PUSHED SOUTH TONIGHT
WITH A MORE ABRUPT SHIFT OF WINDS TO THE N LATE THIS EVENING INTO
THE OVERNIGHT HOURS. THIS WILL PRODUCE A NORTHERLY SURGE WITH
WINDS INCREASING TO AROUND 20 KT LATE TONIGHT. MODELS CONTINUE TO
SHOW WINDS AND SEAS REACHING NEAR SMALL CRAFT SHOULD EXERCISE
CAUTION THRESHOLDS. SEAS 2 TO 4 FT THROUGH THIS EVENING INTO
OVERNIGHT MAY SEE SOME 5 FOOTERS OVERNIGHT ACROSS THE OUTERMOST
WATERS.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...A COLD FRONT WILL HAVE PUSHED EAST OF THE
WATERS AND HIGH PRESSURE WILL BUILD OVER THE WATERS. WINDS WILL
BE FROM THE NORTH AT 15 TO 20 KNOTS ON FRIDAY MORNING AND WILL
SLOWLY WEAKEN TO 10 TO 15 KTS BY THE OF END FRIDAY AND REMAIN AT
THESE SPEEDS. WINDS WILL BEGIN THE DAY FROM THE NORTH AND WILL
VEER TO THE EAST BY SATURDAY. SEA HEIGHTS WILL START OUT AT 2 TO 4
FEET EARLY FRIDAY AND WILL SETTLE OUT AT 2 TO 3 FEET THROUGH
SATURDAY NIGHT.
LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 3 PM THURSDAY...HIGH PRESSURE WILL RULE THE COASTAL WATERS
WITH SOUTHEAST WINDS OF 10 KNOTS SLOWLY SHIFTING TO THE SOUTH AT
10 KNOTS BY TUESDAY. SEAS WILL REMAIN AT 2 TO 3 FEET FOR THE
ENTIRE FORECAST PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RGZ
SHORT TERM...HAWKINS
LONG TERM...HAWKINS
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
315 PM EDT THU MAY 21 2015
.SYNOPSIS...
LOW PRESSURE WILL MOVE OFF OF THE COAST TONIGHT. HIGH PRESSURE
WILL BUILD INTO THE AREA FROM THE NORTHWEST TONIGHT AND FRIDAY.
THE HIGH WILL THEN GRADUALLY MOVE OFFSHORE AND PROVIDE DRY AND
SEASONABLY MILD WEATHER THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 315 PM THURSDAY...CONVECTION FIRING AS EXPECTED IN ADVANCE
OF LOW MOVING EAST ALONG DIFFUSE WARM FRONT BISECTING EASTERN NC
THIS AFTERNOON. EARLIER INSOLATION HELPED TO DESTABILIZE THE
ATMOSPHERE AND WITH INCREASING MID LEVEL FLOW EXPECTED
THUNDERSTORM ORGANIZATION WILL INCREASE AND WITH IT THE THREAT FOR
SEVERE WEATHER. THE MAIN CONCERNS BEING LARGE HAIL AND
DAMAGING WINDS ALTHOUGH AN ISOLATED TORNADO CANNOT BE RULED OUT.
PRECIPITATION SHOULD EAST OF THE COASTAL PLAIN BY 22Z AND
ALONG/OFF THE COAST BY 00Z. NOT EXPECTING MUCH IF ANY
PRECIPITATION AFTER 00Z BUT WILL HOLD ONTO A 30% POP THROUGH 03Z
AS THE HRRR AND RAP-13 MODELS PRODUCE PRECIPITATION AFTER 00Z.
OVERNIGHT LOWS WILL BE COOLER THAN LAST NIGHT WITH READINGS IN THE
MIDDLE TO UPPER 50S.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
AS OF 315 PM THURSDAY...HIGH PRESSURE BUILDING OVER THE AREA FROM
THE NORTH WILL PRODUCE COOLER/DRIER WEATHER ACROSS NC FRIDAY.
HIGHS WILL BE IN THE LOWER TO MIDDLE 70S WITH A FEW UPPER 70S
POSSIBLE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
AS OF 3 PM THU...SEVERAL DAYS OF DRY WEATHER. SURFACE RIDGE OVER
THE EASTERN SEABOARD SATURDAY WILL MOVE OFF THE COAST SUNDAY AND
REMAIN OVER THE WESTERN ATLANTIC THROUGH MIDWEEK. WARM AND HUMID
CONDITIONS DEVELOP EARLY NEXT WEEK IN SOUTHWEST FLOW. COASTAL
PLAINS TROF SETS UP BY WEDNESDAY AND THURSDAY WITH A CHANCE FOR
AFTERNOON AND EVENING CONVECTION GENERALLY ALONG AND WEST OF
HIGHWAY 17.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
SHORT TERM /THROUGH 18Z FRIDAY/...
AS OF 130 PM THURSDAY...CONDITIONS WILL BECOME MVFR FOR THIS
AFTERNOON AS A WARM FRONT LIFTS NORTH THROUGH THE AREA. MOST OF THE
TAF SITES ARE CURRENTLY IN VFR CONDITIONS...BUT ALL THIS WILL
CHANGE ONCE LOW LEVEL CLOUDS START TO LIFT NORTH AND GOOD COVERAGE
OF SHOWERS AND THUNDERSTORMS START TO DEVELOP THIS AFTERNOON.
VISIBILITY MAY REDUCED WITH THE HEAVIER RAINFALL ASSOCIATED WITH
STRONG THUNDERSTORMS (EXPECT GUSTY WINDS). WINDS WILL SHIFT TO
THE NORTH TONIGHT AS THE LOW LIFTS TO THE NE.
FORECASTING SOUNDING CONTINUES TO SHOW LOW LEVEL MOISTURE WILL KEEP
CONDITIONS MVFR OR LOWER....BUT AT THIS MOMENT HAVE INDICATED SCT AT
700 FT AS CONFIDENCE REMAINS LOW. LIGHT NORTHERLY WINDS WILL HELP
PRECLUDE FOG DEVELOPMENT. EXPECT VFR CONDITIONS FOR FRIDAY UNDER
FEW TO SCATTERED CLOUDS.
LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 3 PM THU...DRY/VFR THROUGH THE PERIOD. LIGHT NORTH SURFACE
FLOW SATURDAY THEN LIGHT SOUTHERLY SUNDAY THROUGH TUESDAY.
&&
.MARINE...
SHORT TERM /THROUGH FRIDAY/...
AS OF 315 PM THURSDAY...LOW PRESSURE WILL MOVE ACROSS THE WATERS
THIS EVENING WITH THE FLOW VEERING FROM MODERATE SOUTHERLY TO
NORTHERLY TONIGHT. AS WINDS BECOME NORTH THEY WILL INCREASE TO 20
TO 25 KT OVER THE NORTHERN WATERS WITH SEAS BUILDING TO 4 TO 6 FT
OVER THE NORTHERN AND CENTRAL WATERS. THE COMBINATION OF MODERATE
FLOW AND GUSTY NORTH WINDS TONIGHT WILL PRODUCE MARGINAL ADVISORY
CONDITIONS OVER THE NORTHERN AND CENTRAL WATERS TONIGHT INTO
FRIDAY MORNING. AS HIGH PRESSURE BUILDS OVER THE WATERS FRIDAY
WINDS WILL DIMINISH TO 10 TO 15 KT AND SEAS WILL SUBSIDE TO 3 TO 5
FT.
LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 3 PM THU..DRY FRONT WILL DROP THROUGH FRIDAY NIGHT.
TEMPORARY SURGE IN WINDS/SEAS LATE FRIDAY NIGHT INTO EARLY
SATURDAY BUT WILL REMAIN BELOW SMALL CRAFT LEVELS. GENERALLY
LIGHT WINDS AND SEAS FOR THE REMAINDER OF THE LONG TERM. HIGH
PRESSURE WILL MOVE OFF THE EAST COAST SATURDAY NIGHT AND WILL
REMAIN OVER THE WESTERN ATLANTIC EARLY NEXT WEEK. LIGHT NORTHERLY
FLOW SATURDAY WILL BECOME LIGHT SOUTHERLY SUNDAY THROUGH TUESDAY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT FRIDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
FRIDAY FOR AMZ150.
&&
$$
SYNOPSIS...JME
NEAR TERM...JME
SHORT TERM...JME
LONG TERM...HSA
AVIATION...HSA/BM
MARINE...JME/HSA
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
147 PM EDT THU MAY 21 2015
.SYNOPSIS...
A SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED FOR SOUTHEAST NORTH
CAROLINA INTO THE LOCAL COASTAL WATERS NORTH OF CAPE FEAR THROUGH
8 PM. ANY SEVERE THUNDERSTORMS WILL TRACK EAST AS TROUGH OF LOW
PRESSURE TRACKS EAST TOWARD THE COAST THROUGH THIS AFTERNOON. AS
LOW PRESSURE DEPARTS WELL TO OUR NORTHEAST...IT WILL DRAG A COLD
FRONT ACROSS THE AREA LATE IN THE DAY AND THIS EVENING. HIGH
PRESSURE WILL BUILD ACROSS THE EASTERN CAROLINAS FRIDAY AND
SATURDAY. THE HIGH WILL MOVE OFFSHORE SUNDAY...BRINGING A RETURN
TO HIGHER HUMIDITY BY TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM THURSDAY...SEVERE THUNDERSTORM WATCH 193 HAS BEEN
ISSUED FOR SOUTHEAST NC THROUGH 8 PM. APPROACH OF A WAVE OF LOW
PRESSURE AT THE SURFACE ALONG WITH SHORTWAVE IN THE MID LEVELS
WILL COMBINE WITH HEATING OF THE DAY AND MOISTURE RICH AIR TO TO
CONTINUE TO TRIGGER SHOWERS AND THUNDERSTORMS ACROSS THE EASTERN
CAROLINAS LATE MORNING. THESE THUNDERSTORMS MAY CONTAIN DAMAGING
WINDS AND HAIL. CAN NOT RULE OUT AN ISOLATED TORNADO. A FAIRLY
DECENT LINE SEGMENT HAS DEVELOPED JUST WEST OF ILM CWA INTO
MARLBORO AND DARLINGTON COUNTIES EARLY THIS AFTERNOON ALIGNED WITH
BEST CONVERGENCE ALONG SFC TROUGH AS DRY AIR PUNCHES IN FROM THE
WEST AS EVIDENT ON WATER VAPOR IMAGERY.
THE MID LEVEL SHORTWAVE WILL MOVE ACROSS THE FORECAST AREA NEAR
THE TIME OF PEAK HEATING WITH THE UPPER JET IN A FAVORABLE
POSITION FOR ORGANIZED STORMS TO DEVELOP. THE BEST MOISTURE WILL
BE LOCATED TO THE SOUTH OF WARM FRONT AND CLOSER TO THE COAST WITH
DEWPOINTS UP AROUND 70. THE MARGINAL AREA OUTLINED BY SPC LINES UP
WITH BEST CONVECTIVE PARAMETERS...WITH ML CAPE CLOSE TO 1200 J/KG
AND BULK SHEAR VALUES WILL REACH AROUND 35 KT...HIGHEST ACROSS
SOUTHEAST NORTH CAROLINA. DCAPE WILL BE ABOVE 500 AS SW-WESTERLY
FLOW ALOFT WILL PROMOTE DRYING THROUGH THE MID LEVELS AND A
GREATER INVERTED V TYPE PROFILE THROUGH THE AFTERNOON. THE
DOWNSLOPING WESTERLY FLOW WILL ALSO PRODUCE MORE SUBSIDENCE WHICH
COULD ACT AGAINST CONVECTIVE DEVELOPMENT....BUT THIS WESTERLY
FLOW ALOFT WILL ALSO ALLOW FOR GREATER VERTICAL SHEAR AND MAY SEE
A FEW LINE SEGMENTS DEVELOP WITH POTENTIAL FOR DAMAGING
WIND. CAN NOT RULE OUT SOME HAIL OR BRIEF TORNADO...AS WELL. EXPECT
THIS TO AFFECT MAINLY THE NORTHERN TIER COUNTIES OF LOCAL CWA AND
MAINLY OVER EASTERN NORTH CAROLINA. KEPT POPS HIGHEST IN THIS
AREA. POPS WILL TREND DOWN TO CHANCE AND SLIGHT CHANCE ACROSS MOST
OF SOUTH CAROLINA. ANY STORMS AND CONVECTIVE DEBRIS CLOUDS WILL
MOVE SWIFTLY OFF TO THE EAST IN A 25 TO 35 KT WESTERLY STEERING
FLOW.
THE LINGERING WEAK FRONT WHICH HAS PUSHED BACK NORTH AS A WARM
FRONT WILL GET NUDGED EAST THROUGH THE DAY AS AS SFC LOW SWEEPS
ACROSS THE CAROLINAS AND OFF SHORE BY THIS EVENING. THE BEST CHC
OF MORE WIDESPREAD CONVECTION WILL BE ALONG AND N OF THE LOW
PRESSURE TRACK....PROVIDING THE NECESSARY LIFT FOR SHOWERS AND
THUNDERSTORMS. THEREFORE AS LOW TRACKS OFF THE COAST BY EARLY THIS
EVENING ANY CONVECTION WILL COME TO AN END.
A TRAILING COLD FRONT SHOULD SWEEP OFFSHORE AS LOW PRESSURE PULLS
OFF TO THE NE INTO THIS EVE...BRINGING DRIER AND MORE STABLE AIR
INTO THE AREA OVERNIGHT. WE WILL BE ON THE SOUTHERN PERIPHERY OF
ANOTHER WEAK MID-LEVEL TROUGH PIVOTING AROUND UPPER LOW ACROSS
SOUTHEAST CANADA. THIS MAY BRING AN UPTICK IN CLOUD COVER
OVERNIGHT...BUT NO RAINFALL.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...FAIR WEATHER WITH LOW RELATIVE HUMIDITY
IS EXPECTED THROUGH THE PERIOD AS HIGH PRESSURE SETTLES OVER THE
AREA. MAX TEMPERATURES EACH DAY WILL BE IN THE UPPER 70S TO
LOWER 80S...THOUGH SATURDAY SHOULD BE A DEGREE OR TWO WARMER THAN
FRIDAY. MINS FRIDAY NIGHT WILL FALL TO THE UPPER 50S TO LOWER 60S
AND MODERATE SLIGHTLY TO THE LOW TO MID 60S SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...SURFACE HIGH PRESSURE WILL REMAIN OVER THE
AREA THROUGH THE PERIOD AS A HIGH PRESSURE RIDGE BUILDS IN ALOFT
BY THE MIDDLE OF THE WEEK. THE RESULT WILL BE FAIR WEATHER THROUGH
THE PERIOD BUT TEMPERATURES AND HUMIDITY WILL BE ON THE RISE. MAX
TEMPERATURES WILL MODERATE FROM LOW TO MID 80S SUNDAY TO MID 80S TO
AROUND 90 BY WEDNESDAY. MIN TEMPERATURES WILL ALSO BE ON THE RISE
THROUGH THE PERIOD...GOING FROM LOW TO MID 60S SUNDAY NIGHT TO UPPER
60S TO LOWER 70S BY WEDNESDAY NIGHT. DRY WEATHER IS EXPECTED
THROUGH MOST OF THE PERIOD...THOUGH A SLIGHTLY WEAKER UPPER RIDGE
WEDNESDAY COULD ALLOW FOR THE DEVELOPMENT OF ISOLATED THUNDERSTORMS
DURING THE AFTERNOON AND EVENING.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 18Z...THE HRRR MODEL CONTINUES TO SHOW MODERATE CONVECTION
OVER NORTHERN TERMINALS THROUGH THE AFTERNOON HOURS. THIS AGREES
WITH THE LATEST 12Z RUN OF THE NAM. KLBT WILL BE UNDER THE GUN
19-21Z WITH KILM 20-24Z. AT KCRE MOIST ONSHORE FLOW COULD RESULT
IN TEMPO IFR MARINE STRATUS CIGS THROUGH 20Z...POSSIBLY A FEW
HOURS LATER IF WINDS DO NOT SHIFT FURTHER TO THE SW LATER THIS
AFTERNOON. CONVECTION SHOULD MOVE OFF EARLY THIS EVENING. SW-W
WINDS WILL SHIFT TO THE NORTH TONIGHT AS LOW PRESSURE PULLS OFF TO
THE NE. MUCH DRIER AIR WILL USHER IN OVERNIGHT...WITH VFR CONDITIONS
EXPECTED FOR FRIDAY WITH SCATTERED SKIES.
EXTENDED OUTLOOK...VFR. MORNING FOG POSSIBLE MONDAY AND TUESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM THURSDAY...SEVERE THUNDERSTORM WATCH 193 HAS BEEN
ISSUED FOR SOUTHEAST NC INTO THE LOCAL COASTAL WATERS NORTH OF
CAPE FEAR THROUGH 8 PM. SW WINDS 15 TO 20 KT AHEAD OF A COLD
FRONT...WILL SHIFT TO THE NW THIS EVE...AND THEN N OVERNIGHT AS
LOW PRESSURE TO OUR N MOVES FURTHER AWAY. A DEVELOPING NORTHERLY
SURGE WILL INCREASE WINDS TO AROUND 20 KT LATE TONIGHT AND WE WILL
BE NEAR SMALL CRAFT SHOULD EXERCISE CAUTION LEVELS. SEAS WILL BE 2
TO 4 FT TODAY WITH SOME 5 FT SEAS ACROSS THE OUTERMOST WATERS LATE
TONIGHT. WINDS AND SEAS WILL BE LOCALLY HIGHER IN SCATTERED TO
NUMEROUS THUNDERSTORMS TODAY AND THIS EVE.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...LOOKS LIKE A QUIET PERIOD ON THE WATERS WITH
NE WINDS OF 10 TO 15 KT FRIDAY INTO SATURDAY THAT WILL BECOME MORE
EASTERLY BY SATURDAY NIGHT. SEAS OF 3 FEET OR LESS ARE EXPECTED
THROUGH THE PERIOD.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 300 AM THURSDAY...SUMMER LIKE CONDITIONS WILL CONTINUE ON THE
WATERS WITH SE WINDS OF 10 TO 15 KT EXPECTED THROUGH THE FORECAST
PERIOD WITH SEAS OF 3 FT OR LESS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RGZ
SHORT TERM...RAN
LONG TERM...RAN
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
114 PM EDT THU MAY 21 2015
.SYNOPSIS...
A SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED FOR SOUTHEAST NORTH
CAROLINA INTO THE LOCAL COASTAL WATERS NORTH OF CAPE FEAR THROUGH
8 PM. ANY SEVERE THUNDERSTORMS WILL TRACK EAST AS TROUGH OF LOW
PRESSURE TRACKS EAST TOWARD THE COAST THROUGH THIS AFTERNOON. AS
LOW PRESSURE DEPARTS WELL TO OUR NORTHEAST...IT WILL DRAG A COLD
FRONT ACROSS THE AREA LATE IN THE DAY AND THIS EVENING. HIGH
PRESSURE WILL BUILD ACROSS THE EASTERN CAROLINAS FRIDAY AND
SATURDAY. THE HIGH WILL MOVE OFFSHORE SUNDAY...BRINGING A RETURN
TO HIGHER HUMIDITY BY TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM THURSDAY...SEVERE THUNDERSTORM WATCH 193 HAS BEEN
ISSUED FOR SOUTHEAST NC THROUGH 8 PM. APPROACH OF A WAVE OF LOW
PRESSURE AT THE SURFACE ALONG WITH SHORTWAVE IN THE MID LEVELS
WILL COMBINE WITH HEATING OF THE DAY AND MOISTURE RICH AIR TO TO
CONTINUE TO TRIGGER SHOWERS AND THUNDERSTORMS ACROSS THE EASTERN
CAROLINAS LATE MORNING. THESE THUNDERSTORMS MAY CONTAIN DAMAGING
WINDS AND HAIL. CAN NOT RULE OUT AN ISOLATED TORNADO. A FAIRLY
DECENT LINE SEGMENT HAS DEVELOPED JUST WEST OF ILM CWA INTO
MARLBORO AND DARLINGTON COUNTIES EARLY THIS AFTERNOON ALIGNED WITH
BEST CONVERGENCE ALONG SFC TROUGH AS DRY AIR PUNCHES IN FROM THE
WEST AS EVIDENT ON WATER VAPOR IMAGERY.
THE MID LEVEL SHORTWAVE WILL MOVE ACROSS THE FORECAST AREA NEAR
THE TIME OF PEAK HEATING WITH THE UPPER JET IN A FAVORABLE
POSITION FOR ORGANIZED STORMS TO DEVELOP. THE BEST MOISTURE WILL
BE LOCATED TO THE SOUTH OF WARM FRONT AND CLOSER TO THE COAST WITH
DEWPOINTS UP AROUND 70. THE MARGINAL AREA OUTLINED BY SPC LINES UP
WITH BEST CONVECTIVE PARAMETERS...WITH ML CAPE CLOSE TO 1200 J/KG
AND BULK SHEAR VALUES WILL REACH AROUND 35 KT...HIGHEST ACROSS
SOUTHEAST NORTH CAROLINA. DCAPE WILL BE ABOVE 500 AS SW-WESTERLY
FLOW ALOFT WILL PROMOTE DRYING THROUGH THE MID LEVELS AND A
GREATER INVERTED V TYPE PROFILE THROUGH THE AFTERNOON. THE
DOWNSLOPING WESTERLY FLOW WILL ALSO PRODUCE MORE SUBSIDENCE WHICH
COULD ACT AGAINST CONVECTIVE DEVELOPMENT....BUT THIS WESTERLY
FLOW ALOFT WILL ALSO ALLOW FOR GREATER VERTICAL SHEAR AND MAY SEE
A FEW LINE SEGMENTS DEVELOP WITH POTENTIAL FOR DAMAGING
WIND. CAN NOT RULE OUT SOME HAIL OR BRIEF TORNADO...AS WELL. EXPECT
THIS TO AFFECT MAINLY THE NORTHERN TIER COUNTIES OF LOCAL CWA AND
MAINLY OVER EASTERN NORTH CAROLINA. KEPT POPS HIGHEST IN THIS
AREA. POPS WILL TREND DOWN TO CHANCE AND SLIGHT CHANCE ACROSS MOST
OF SOUTH CAROLINA. ANY STORMS AND CONVECTIVE DEBRIS CLOUDS WILL
MOVE SWIFTLY OFF TO THE EAST IN A 25 TO 35 KT WESTERLY STEERING
FLOW.
THE LINGERING WEAK FRONT WHICH HAS PUSHED BACK NORTH AS A WARM
FRONT WILL GET NUDGED EAST THROUGH THE DAY AS AS SFC LOW SWEEPS
ACROSS THE CAROLINAS AND OFF SHORE BY THIS EVENING. THE BEST CHC
OF MORE WIDESPREAD CONVECTION WILL BE ALONG AND N OF THE LOW
PRESSURE TRACK....PROVIDING THE NECESSARY LIFT FOR SHOWERS AND
THUNDERSTORMS. THEREFORE AS LOW TRACKS OFF THE COAST BY EARLY THIS
EVENING ANY CONVECTION WILL COME TO AN END.
A TRAILING COLD FRONT SHOULD SWEEP OFFSHORE AS LOW PRESSURE PULLS
OFF TO THE NE INTO THIS EVE...BRINGING DRIER AND MORE STABLE AIR
INTO THE AREA OVERNIGHT. WE WILL BE ON THE SOUTHERN PERIPHERY OF
ANOTHER WEAK MID-LEVEL TROUGH PIVOTING AROUND UPPER LOW ACROSS
SOUTHEAST CANADA. THIS MAY BRING AN UPTICK IN CLOUD COVER
OVERNIGHT...BUT NO RAINFALL.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...FAIR WEATHER WITH LOW RELATIVE HUMIDITY
IS EXPECTED THROUGH THE PERIOD AS HIGH PRESSURE SETTLES OVER THE
AREA. MAX TEMPERATURES EACH DAY WILL BE IN THE UPPER 70S TO
LOWER 80S...THOUGH SATURDAY SHOULD BE A DEGREE OR TWO WARMER THAN
FRIDAY. MINS FRIDAY NIGHT WILL FALL TO THE UPPER 50S TO LOWER 60S
AND MODERATE SLIGHTLY TO THE LOW TO MID 60S SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 300 AM THURSDAY...SURFACE HIGH PRESSURE WILL REMAIN OVER THE
AREA THROUGH THE PERIOD AS A HIGH PRESSURE RIDGE BUILDS IN ALOFT
BY THE MIDDLE OF THE WEEK. THE RESULT WILL BE FAIR WEATHER THROUGH
THE PERIOD BUT TEMPERATURES AND HUMIDITY WILL BE ON THE RISE. MAX
TEMPERATURES WILL MODERATE FROM LOW TO MID 80S SUNDAY TO MID 80S TO
AROUND 90 BY WEDNESDAY. MIN TEMPERATURES WILL ALSO BE ON THE RISE
THROUGH THE PERIOD...GOING FROM LOW TO MID 60S SUNDAY NIGHT TO UPPER
60S TO LOWER 70S BY WEDNESDAY NIGHT. DRY WEATHER IS EXPECTED
THROUGH MOST OF THE PERIOD...THOUGH A SLIGHTLY WEAKER UPPER RIDGE
WEDNESDAY COULD ALLOW FOR THE DEVELOPMENT OF ISOLATED THUNDERSTORMS
DURING THE AFTERNOON AND EVENING.
&&
.AVIATION /17Z THURSDAY THROUGH MONDAY/...
PATCHY DENSE FOG SHOULD DISSIPATE FAIRLY RAPIDLY THIS MORNING AS
SOUTHWEST FLOW COMMENCES AHEAD OF LOW PRESSURE CENTERED JUST WEST OF
THE REGION. THIS SOUTHWEST FLOW WILL INCREASE THIS MORNING...WITH
GUSTS OVER 20 KTS EXPECTED BY LATE MORNING. THE HRRR MODEL CONTINUES
TO SHOW MODERATE CONVECTION OVER OUR NORTHERN COUNTIES. OUR NORTHERN
COASTAL COUNTIES STAND THE BEST CHANCE FOR SHOWERS AS THEY WILL
LIKELY HEAT UP THE MOST AND WILL HAVE THE LOW LEVEL CONVERGENCE OF
THE SEA BREEZE BOUNDARY. THE LOW AND ASSOCIATED CONVECTION WILL EXIT
THE AREA THIS EVENING...WITH NORTHERLY WINDS ON THE BACK SIDE.
EXTENDED OUTLOOK...VFR. FOG POSSIBLE MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM THURSDAY...SEVERE THUNDERSTORM WATCH 193 HAS BEEN
ISSUED FOR SOUTHEAST NC INTO THE LOCAL COASTAL WATERS NORTH OF
CAPE FEAR THROUGH 8 PM. SW WINDS 15 TO 20 KT AHEAD OF A COLD
FRONT...WILL SHIFT TO THE NW THIS EVE...AND THEN N OVERNIGHT AS
LOW PRESSURE TO OUR N MOVES FURTHER AWAY. A DEVELOPING NORTHERLY
SURGE WILL INCREASE WINDS TO AROUND 20 KT LATE TONIGHT AND WE WILL
BE NEAR SMALL CRAFT SHOULD EXERCISE CAUTION LEVELS. SEAS WILL BE 2
TO 4 FT TODAY WITH SOME 5 FT SEAS ACROSS THE OUTERMOST WATERS LATE
TONIGHT. WINDS AND SEAS WILL BE LOCALLY HIGHER IN SCATTERED TO
NUMEROUS THUNDERSTORMS TODAY AND THIS EVE.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...LOOKS LIKE A QUIET PERIOD ON THE WATERS WITH
NE WINDS OF 10 TO 15 KT FRIDAY INTO SATURDAY THAT WILL BECOME MORE
EASTERLY BY SATURDAY NIGHT. SEAS OF 3 FEET OR LESS ARE EXPECTED
THROUGH THE PERIOD.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 300 AM THURSDAY...SUMMER LIKE CONDITIONS WILL CONTINUE ON THE
WATERS WITH SE WINDS OF 10 TO 15 KT EXPECTED THROUGH THE FORECAST
PERIOD WITH SEAS OF 3 FT OR LESS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RGZ
SHORT TERM...RAN
LONG TERM...RAN
AVIATION...DL
AREA FORECAST DISCUSSION
NWS PORTLAND
233 PM PDT THU MAY 21 2015
.SYNOPSIS...A BROAD UPPER LEVEL TROUGH OVER THE EASTERN PACIFIC AND
ALONG THE WEST COAST WILL CONTINUE TO BRING A THREAT OF SHOWERS AND
THUNDERSTORMS TO THE CASCADES THROUGH THIS EVENING. THE MARINE LAYER
IS EXPECTED TO DEEPEN TONIGHT AND FRIDAY. THIS WILL PUSH THE
CONVECTIVE THREAT EAST OF THE CASCADES. STRONG ONSHORE FLOW WILL
CONTINUE THROUGH SATURDAY...THEN WEAKEN A LITTLE SUNDAY. ANOTHER
UPPER LOW LOOKS LIKE IT WILL APPROACH THE AREA EARLY NEXT WEEK...
BRINGING CONTINUED SHOWER CHANCES.
&&
.SHORT TERM...TONIGHT THROUGH SUNDAY...CONVECTION ALREADY FIRING
EARLY THIS AFTERNOON IN THE HIGHER CASCADES. A FEW LIGHTNING STRIKES
NOTED IN NE COWLITZ COUNTY IN THE WA CASCADES AND ALSO MCKENZIE PASS
IN THE LANE COUNTY CASCADES. THE 02 HR FCST OFF THE 18Z HRRR RUN
DEPICTS THE GENERAL CONVECTIVITY REASONABLY WELL. CELLS ARE DRIFTING
EAST TO WEST...BUT THE GENERAL TREND HAS BEEN FOR THEM TO WEAKEN UPON
REACHING THE LOWER CASCADE FOOTHILLS.
THE OVERALL LARGE-SCALE PATTERN THROUGH TONIGHT CONSISTS OF A BROAD
UPPER LOW CENTERED OFF THE CENTRAL CALIFORNIA COAST WITH MULTIPLE
SUBTLE SHORT-WAVES ROTATING AROUND IT. MEANWHILE...THERE IS A SECOND
LOW ALONG THE CENTRAL BRITISH COLUMBIA COAST. THIS WILL BE THE ONE
THAT BECOMES THE MAIN PLAYER LATER IN THE WEEKEND. VERY MOIST AIR
MASS IN PLACE AS EVIDENCED BY THE 1.11 PRECIPITABLE WATER FROM
THE 12Z KSLE SOUNDING. THIS IS WELL ABOVE THE 90TH PERCENTILE VALUE
FOR THIS TIME OF YEAR...OR ABOUT 2 STANDARD DEVIATIONS ABOVE AVERAGE.
THE SOUNDING ALSO SHOWED EAST FLOW FROM AROUND 850 MB THROUGH 300 MB.
THE 18Z HRRR SHOWS QPF SPREADING INTO THE WILLAMETTE VALLEY THIS
EVENING...GENERALLY AFTER 01Z FRI. ALTHOUGH MODEL SOUNDINGS FOR THE
WILLAMETTE VALLEY SHOW IMPRESSIVE CONVECTIVE POTENTIAL...NOT
EXPECTING MUCH IN THE WAY OF THUNDERSTORMS WEST OF THE CASCADE
FOOTHILLS. MODEL SOUNDINGS...ESPECIALLY THE NAM...ARE TOO HIGH WITH
THE SFC DEW POINTS. AS AN EXAMPLE...THE NAM SOUNDING FOR KPDX GIVES A
DEW POINT OF 62-65 DEG 00Z FRI...WHICH TRANSLATES TO NEARLY 2500 J/KG
SFC-BASED CAPE. THE GFS IS NOT AS EXTREME...BUT STILL INDICATES
SURFACE DEW POINTS NEAR 60.
THE SPC STORM-SCALE ENSEMBLE OF OPPORTUNITY...SSEO...FOCUSES
REFLECTIVITY VALUES OVER SW WA CASCADES AND FOOTHILLS INTO THE N
WILLAMETTE VALLEY 00Z TO 03Z FRI. IT ALSO INDICATES A 70 PCT OR
GREATER PROBABILITY OF 40 DBZ ECHOES OR GREATER. MODIFIED FORECAST
SOUNDING VALID 00Z FRI WITH A DEW POINT CLOSER TO 50 DEG F AND
SLIGHTLY COOLER SFC TEMP YIELDS A MORE REALISTIC CAPE OF ABOUT 900
J/KG... MIXED LAYER CAPE OF 675 J/KG AND LI OF -3C. THE COASTAL ZONES
HAVE THE LOWEST POPS THROUGH THIS EVENING. BY 06Z FRI THE BULK OF THE
FORECAST AREA WILL RESIDE IN A COL AREA AS THE UPPER LOW AND
ASSOCIATED EAST FLOW SINK SOUTH INTO CALIFORNIA AND NEVADA.
THE HI-RES WRF-ARW AND A MODEL CROSS-SECTION FROM KAST-KDLS SHOW A
FAIRLY SUBSTANTIAL MARINE LAYER BY 12Z FRI...DUE TO ANOTHER SYSTEM
DROPPING SOUTH ALONG THE BRITISH COLUMBIA COAST TO THE SOUTH
WASHINGTON AND NORTH OREGON COAST. THE WRF-ARW INDICATES AFTERNOON
CLEARING...AS DO FCST MODEL SOUNDINGS. THE MAIN CHANGE FRI WILL BE A
CHANGE IN FLOW ALOFT FROM THE WEAK EAST OF THE PAST COUPLE DAYS TO
MORE NW-N. THIS RESULTS IN A MORE STABLE AIR MASS...PUSHING THE
THUNDERSTORM THREAT FRI EAST OF THE CASCADES.
12Z MODEL RUNS HAVE AN UPPER TROUGH EXTENDING FROM VANCOUVER ISLAND
TO THE FAR N OREGON COAST 12Z SAT. GFS MODEL SOUNDINGS SUGGEST MARINE
LAYER TOPS TO NEARLY 5000 FT SAT MORNING. HAVE ADDED A MENTION OF
DRIZZLE SAT MORNING DUE TO THE FCST DEPTH OF THE MARINE LAYER. GOING
WITH SLIGHT CHANCE TO CHANCE POPS SAT AFTERNOON IN THE S WA AND FAR N
OREGON CASCADES...CLOSEST TO THE COL AREA. LEFT OUT ANY MENTION OF
THUNDERSTORMS. MODELS STILL SHOWING LARGE DIFFERENCES SUN AND BEYOND.
IF THE ECMWF IS CORRECT...THERE WOULD BE STRONGER ONSHORE FLOW SUN
WITH LESS AFTERNOON SUN. THE GFS AND NAM HAVE LESS ONSHORE FLOW. IN
ANY EVENT...GENERAL CONDITIONS LOOK STABLE...WITH ANY SHOWER THREAT
CONFINED TO NRN PART OF S WA CASCADE ZONE.
WEISHAAR
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY...GFS AND ECMWF BOTH SHOW
AN UPPER LEVEL LOW OR TROUGH SITTING OVER OREGON AND WASHINGTON
THROUGH TUE. MAIN MODEL DIFFERNCE IS THAT THE GFS MAINTAINS A CLOSED
FEATURE...KEEPING IT OVER SW WA...WHILE THE ECMWF HAS MORE OF AN OPEN
TROUGH A LITTLE MORE EAST THAN THE GFS. REGARDLESS OF WHICH MODEL
VERIFIES BEST...THE MAIN SENSIBLE WEATHER FOR THE CWA WOULD BE
CONTINUED ONSHORE LOW-LEVEL FLOW WITH THE BEST THREAT OF SHOWERS...
ALBEIT SMALL...OVER THE CASCADES. THE GFS HOLDS THE UPPER LOW
SOMEWHERE OVER SE WA WED...WHILE THE ECMWF HAS A MORE PRORESSIVE NWLY
FLOW ALOFT. HAVE GONE WITH SLIGHT CHANCE POPS FOR THE CASCADES
WED...BUT IF THE GFS IS MORE RIGHT...THEN IT WOULD BE DRY. TOO MUCH
UNCERTAINTY TO TOTALLY DISREGARD ANY PRECIP THREAT. WEISHAAR
&&
.AVIATION...SCATTERED SHOWERS OVER THE CASCADES WILL CONTINUE TO
DRIFT WEST THIS AFTERNOON/EVENING. ISOLATED THUNDERSTORMS HAVE
BEGUN TO FORM OVER THE LINN AND LANE COUNTY CASCADES. EXPECT THE
THREAT FOR LIGHTNING TO INCREASE INTO THIS EVENING. THESE SHOWERS
CONTINUE TO BRING A MIXTURE OF VFR TO MVFR CIGS TO THE INLAND
VALLEY...WITH BRIEF PERIODS OF REDUCED FLIGHT RULES UNDER HEAVIER
SHOWERS. CONDITIONS INLAND WILL ONCE AGAIN DETERIORATE TOWARDS
MVFR AFTER 06Z. MARINE STRATUS WILL FILTER INLAND LATE TONIGHT.
THE COAST CONTINUES TO REMAIN SOCKED IN UNDER WEAK ONSHORE FLOW.
IFR CIGS HAVE RAISED A FEW HUNDRED FEET AND WILL CONTINUE TO
RISE THIS AFTERNOON...WITH MVFR CIGS POSSIBLE FOR A FEW HOURS.
HOWEVER...ANY IMPROVEMENTS WILL BE SHORT LIVED WITH CIGS LOWERING
TOWARDS IFR THIS EVENING AS MARINE STRATUS RETURNS.
KPDX AND APPROACHES...CONDITIONS WILL REMAIN MOSTLY VFR THIS
AFTERNOON AND EVENING. SCATTERED SHOWERS WILL CONTINUE TO DRIFT
WEST AND COULD IMPACT THE TERMINAL WITH PERIODS OF REDUCED FLIGHT
RULES UNDER HEAVIER SHOWERS. CONDITIONS DETERIORATE TOWARDS MVFR
AFTER 06Z. MARINE STRATUS WILL FILTER IN AGAIN LATE TONIGHT. /64
&&
.MARINE...A RATHER PERSISTENT WEATHER PATTERN WITH HIGH PRES
CENTERED ABOUT 600 NM OFFSHORE WILL CONTINUE THROUGH THE REST OF
THE WEEK AND THE WEEKEND. THIS WILL KEEP WINDS OUT OF THE NW BUT
GENERALLY BELOW 20 KT. A FRESH SWELL OF 5 TO 6 FT WILL ALSO
CONTINUE OUT OF THE WNW.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.
&&
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS PORTLAND
916 AM PDT THU MAY 21 2015
.SYNOPSIS...A BROAD UPPER LEVEL TROUGH OVER THE EASTERN PACIFIC AND
ALONG THE WEST COAST WILL CONTINUE TO BRING A THREAT OF SHOWERS AND
THUNDERSTORMS TO THE CASCADES THROUGH THIS EVENING. THE MARINE LAYER
IS EXPECTED TO DEEPEN TONIGHT AND FRIDAY. THIS WILL PUSH THE
CONVECTIVE THREAT EAST OF THE CASCADES. THE STRONGER ONSHORE FLOW
WILL CONTINUE THROUGH THE WEEKEND WITH SOME THREAT OF SHOWERS.
ANOTHER UPPER LOW LOOKS LIKE IT WILL APPROACH THE AREA EARLY NEXT
WEEK...BRINGING CONTINUED SHOWER CHANCES.
&&
.SHORT TERM...MORNING VISIBLE SATELLITE IMAGERY SHOWS CONSIDERABLE
CLOUD COVER ACROSS THE AREA. KRTX DUAL-POL DOPPLER RADAR INDICATING
SOME SHOWER ACTIVITY ACROSS THE CENTRAL OREGON COAST RANGE AND
COAST...AS WELL AS THE NORTH AND CENTRAL OREGON CASCADES. VERY MOIST
AIR MASS IN PLACE AS EVIDENCED BY THE 1.11 PRECIPITABLE WATER FROM
THE 12Z KSLE SOUNDING. THIS IS WELL ABOVE THE 90TH PERCENTILE VALUE
FOR THIS TIME OF YEAR. THE SOUNDING ALSO SHOWED EAST FLOW FROM AROUND
850 MB THROUGH 300 MB.
THE MARINE LAYER THIS MORNING APPEARS TO BE MORE BROKEN...EXCEPT
ALONG THE COASTAL AREAS. THE HI-RES WRF-ARW MAINTAINS THE MARINE
LAYER THROUGH AT LEAST 18Z THEN SHOWS IT BREAKING UP IN SW WA AND THE
N OREGON COASTS RANGE BETWEEN 18Z AND 21Z. OBVIOUSLY...CLOUD COVER
WILL HAVE A BIG IMPACT ON THE ABILITY FOR PARCELS TO REACH THE
CONVECTIVE TEMPERATURE. THE 14Z HRRR SHOWS SHOWERS AND POSSIBLE
CONVECTION DEVELOPING OVER THE HIGHER CASCADES AS EARLY AS 18Z ...BUT
THE GREATER COVERAGE LOOKS TO OCCUR JUST AFTER 00Z FRI. THE SPC
STORM-SCALE ENSEMBLE OF OPPORTUNITY...SSEO...FOCUSES REFLECTIVITY
VALUES OVER SW WA CASCADES AND FOOTHILLS INTO THE N WILLAMETTE VALLEY
00Z TO 03Z FRI. IT ALSO INDICATES A 70 PCT OR GREATER PROBABILITY OF
40 DBZ ECHOES OR GREATER. NAM AND GFS FORECAST SOUNDING FOR A POINT
NEAR SANTIAM PASS SHOWS IMPRESSIVE CONVECTIVE PARAMETERS LATE THIS
AFTERNOON...WITH CAPES IN EXCESS OF 1500 J/KG...MIXED LAYER CAPES OF
750 J/KG AND LI OF -4 TO -6 DEG C. ALL OF THIS IS PREDICATED ON A SFC
DEW POINT OF CLOSE TO 55 DEG F AT 850 MB...WHICH IS A LITTLE
OVERDONE. MODIFIED FORECAST SOUNDING VALID 00Z FRI WITH A DEW POINT
CLOSER TO 50 DEG F AND SLIGHTLY COOLER SFC TEMP YIELDS A MORE
REALISTIC CAPE OF ABOUT 900 J/KG... MIXED LAYER CAPE OF 675 J/KG AND
LI OF -3C. MODIFIED SOUNDING ALSO SHOWED MINIMAL CIN SO IF THERE IS
ANY APPRECIABLE SUNSHINE CONVECTION SHOULD DEVELOP QUICKLY. HIGHEST
POPS THIS AFTERNOON AND THIS EVENING WILL BE OVER THE CASCADES AND
FOOTHILLS...BUT THE DEEP EAST FLOW WILL ALLOW ANY SHOWERS AND
THUNDERSTORMS THAT DEVELOP OVER THE CASCADES TO DRIFT INTO THE
WILLAMETTE VALLEY. THE COASTAL ZONES HAVE THE LOWEST POPS...ALTHOUGH
A CELL EARLY THIS MORNING DROPPED JUST OVER ONE-HALF INCH OF RAIN AT
KONP IN A SHORT TIME. BY 06Z FRI THE BULK OF THE FORECAST AREA WILL
RESIDE IN A COL AREA AS THE UPPER LOW AND ASSOCIATED EAST FLOW SINK
SOUTH INTO CALIFORNIA AND NEVADA.
THE MODELS SHOW ANOTHER SYSTEM DROPPING SOUTH ALONG THE BRITISH
COLUMBIA COAST TO THE SOUTH WASHINGTON AND NORTH OREGON COAST FRIDAY.
THIS WILL DEEPEN THE MARINE LAYER IN SOUTHWEST WASHINGTON AND
NORTHWEST OREGON...AND MAY MAKE IT DIFFICULT FOR THE LOW CLOUDS TO
CLEAR IN THE AFTERNOON. IN ADDITION...THE WINDS AT ALL LEVELS ARE
TURNING MORE WEST TO NORTHWESTERLY...AND THIS SHOULD PUSH MOST OF THE
THUNDERSTORMS EAST OF THE CASCADE CREST FRIDAY AFTERNOON AND EVENING.
IF ANY DO FORM...IT WILL BE BRIEFLY RIGHT AT THE CREST AND THEN THEY
WILL MOVE OFF INTO CENTRAL OREGON...BUT HAVE LEFT THUNDER OUT OF THE
FORECAST AT THIS TIME.
ON FRIDAY NIGHT AND SATURDAY...THE SYSTEM APPROACHING FROM THE
NORTHWEST MOVES ACROSS OUR AREA. THIS SHOULD MAINTAIN SUBSTANTIAL
ONSHORE FLOW. THE BIGGEST QUESTION IS WHETHER THE COLD POOL
ASSOCIATED WITH THE LOW WILL MOVE OVERHEAD...WHICH COULD TRIGGER SOME
SHOWERS OR EVEN SOME THUNDERSTORMS. THE MODELS HAVE SHOWN A VARIETY
OF SOLUTIONS. THE GFS HAS SUGGESTED AT TIMES THAT THE ABOVE SCENARIO
IS POSSIBLE. THE ECMWF AND CANADIAN MODELS HAVE BEEN SHEARING A LEAD
SHORT WAVE SOUTH ALONG THE COAST SATURDAY...WAITING UNTIL SUNDAY FOR
A TRAILING LOW TO COME OVERHEAD. WILL CONTINUE THE BROAD BRUSHED
CHANCE OF SHOWERS FOR NOW WITH MEDIOCRE CONFIDENCE IN ANY DETAILS AT
BEST. WEISHAAR
.LONG TERM...NO SIGNIFICANT CHANGES. PREVIOUS DISCUSSION FOLLOWS...
SATURDAY NIGHT THROUGH WEDNESDAY...MODELS HAVE AGAIN COME INTO
REASONABLE AGREEMENT THAT AN UPPER LOW WILL SLIDE ACROSS THE PACIFIC
NORTHWEST LATE SATURDAY INTO SUNDAY...THOUGH STILL PLENTY OF SPREAD
AMONG MODEL GUIDANCE AS TO IF THE LOW TRACKS MORE EASTWARD ACROSS THE
CASCADES OR MORE SOUTHWARD TOWARDS THE GREAT BASIN. REGARDLESS...
INTRODUCED SLIGHT CHANCE POPS FOR MOST OF THE AREASUNDAY. MAY END UP
SEEING SOME THUNDERSTORMS NEAR THE CASCADE CREST IF THE UPPER LOW
TRACKS OVERHEAD AND LINGERS. FLOW ALOFT LOOKS TO REMAIN RATHER WEAK
OR WEAKLY ONSHORE WITH CONTINUED POSSIBILITIES FOR SHOWERS IN THE
CASCADES. TEMPERATURES WILL REMAIN NEAR SEASONAL FOR THE FIRST HALF
OF NEXT WEEK. CULLEN
&&
.AVIATION...ISOLATED SHOWERS CONTINUE TO MOVE THROUGH THE REGION
THIS MORNING BRINGING A MIXTURE OF VFR TO MVFR CIGS TO THE INLAND
VALLEY. THE COAST REMAINS SOCKED IN UNDER WEAK ONSHORE FLOW WITH
IFR/LIFR CIGS AOB 700 FT. CONDITIONS INLAND LOOK TO GRADUALLY
IMPROVE TOWARDS WIDESPREAD VFR AFTER 18Z. CIGS ALONG THE COAST
LOOK TO LIFT LATE THIS MORNING WITH CONDITIONS LIKELY TURNING MVFR
FOR A FEW HOURS THIS AFTERNOON. ISOLATED TO SCATTERED SHOWERS LOOK
TO CONTINUE THROUGH AT LEAST THIS EVENING...WITH THUNDERSTORMS
POSSIBLE ALONG THE CASCADES AND FOOTHILLS. BRIEF PERIODS OF
REDUCED FLIGHT RULES WILL BE POSSIBLE UNDER HEAVIER SHOWERS.
CONDITIONS TONIGHT WILL ONCE AGAIN DETERIORATE TOWARDS MVFR INLAND
AND IFR ALONG THE COAST AS MARINE STRATUS RETURNS.
KPDX AND APPROACHES...A MIXTURE OF MVFR TO VFR CIGS WILL GIVE WAY
TO MOSTLY VFR CONDITIONS AFTER 18Z. SCATTERED SHOWERS CONTINUE
THROUGH THIS EVENING...WITH BRIEF PERIODS OF REDUCED FLIGHT RULES
POSSIBLE UNDER HEAVIER SHOWERS. CONDITIONS DETERIORATE TOWARD MVFR
LATE TONIGHT AS MARINE STRATUS RETURNS. /64
&&
.MARINE...A RATHER PERSISTENT WEATHER PATTERN WITH HIGH PRES
CENTERED ABOUT 600 NM OFFSHORE WILL CONTINUE THROUGH THE REST OF THE
WEEK AND THE WEEKEND. THIS WILL KEEP WINDS OUT OF THE NW BUT
GENERALLY BELOW 20 KT. A FRESH SWELL OF 5 TO 6 FT WILL ALSO
CONTINUE OUT OF THE WNW.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.
&&
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
529 PM EDT THU MAY 21 2015
.SYNOPSIS...
AN UNSEASONABLY COOL WEATHER PATTERN WILL CONTINUE THROUGH THE
END OF THE WEEK WITH A RATHER CHILLY START TO THE WEEKEND. A
GRADUAL WARMING TREND IS FORECAST THROUGH THE EARLY TO MIDDLE PART
OF NEXT WEEK ALONG WITH AN INCREASING RISK FOR SHOWERS AND
THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
FLOW AROUND AN AREA OF LOW PRESSURE OVER NORTH CAROLINA THIS AFTN
WILL CONTINUE TO SUPPORT A LARGE AREA OF CLOUDS ACROSS PA. RADAR
IMAGERY SHOWS THAT SHOWERS HAVE MOVED EAST OF THE STATE FOR THE
TIME BEING. HOWEVER...A SHORTWAVE CURRENTLY MOVING ACROSS THE
OHIO VALLEY WILL LIKELY HELP FIRE SOME MORE SHOWERS ACROSS THE NRN
MTNS AND LAURELS LATE THIS AFTN AND EVENING. LATEST HRRR GUIDANCE
SUGGESTS THOUGH THAT THEY SHOULD REMAIN ISOLATED IN COVERAGE.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
THE MAIN LARGE SCALE UPPER TROUGH AXIS IS PROGGED TO ROTATE
THROUGH THE ERN GREAT LAKES AND NRN NEW ENGLAND ON FRIDAY WHICH
SHOULD DRIVE A RE-ENFORCING SFC COLD FRONT THROUGH CENTRAL PA.
MODEL CONSENSUS CONTINUES TO SUGGEST ISOLD/WDLY SCT SHOWERS WITH
THE FRONTAL PASSAGE BUT WITH VERY LIMITED MSTR KEPT POPS AOB 20
PCT. MAX TEMPS SHOULD MODERATE SOME BUT STILL AVG BELOW NORMAL
FOR THIS TIME OF YEAR.
BEHIND THE COLD FRONT ACROSS THE REGION...A SPRAWLING AREA OF
HIGH PRESSURE /1030MB+/ WILL BUILD UNDER A DEVELOPING LARGE UPPER
RIDGE OVER THE REGION. A REINFORCING SHOT OF COLDER AIR AHEAD OF
RIDGE AXIS WILL BRING QUITE CHILLY TEMPS FOR SAT MORNING...WHERE A
FREEZE IS LOOKING MORE LIKELY ACROSS MUCH OF THE NORTHERN MTNS. A
/WELL COORDINATED/ FREEZE WATCH REMAINS IN EFFECT THERE...WITH
SCT FROST EXTENDING INTO THE LAUREL HIGHLANDS AND PORTIONS OF THE
CENTRAL MTNS. POTENTIAL FLY IN THE OINTMENT COULD BE THE
WINDS...THOUGH LIGHT...REMAINING JUST HIGH ENOUGH TO KEEP TEMPS
FROM BOTTOMING OUT COMPLETELY.
THE COLD AIR IS QUICKLY REPLACED BY MODERATING TEMPS ON SAT...AS
HIGHS REBOUND INTO THE 60S UNDER FULL SUN. NOT QUITE AS CHILLY FOR
SAT NIGHT WITH LOWS SETTLING BACK INTO THE 40S IN MOST
LOCALES...UPPER 30S POSS IN THE NW MTNS.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
SUNDAY MARKS BEGINNING OF A ROBUST WARM-UP THAT WILL CONTINUE
THROUGH NEXT WEEK. ALL GUIDANCE SIGNALS THIS WARMING TREND...WITH
HIGH CONFIDENCE IN ABOVE NORMAL TEMPERATURES BY MEMORIAL DAY AS
ANOMALOUS 500MB RIDGE BUILDS OVER THE EASTERN U.S.
SOME DIFFERENCES ON PLACEMENT OF A WARM FRONTAL ZONE LIFTING NWD
FROM THE SRN PLAINS/LWR MS VLY WHICH WILL HAVE IMPACTS ON PCPN
RISK EARLY NEXT WEEK...THOUGH BEST DAILY POPS /HIGH CHANCE TO LOW
LIKELY/ WILL BE OVER THE NW WITH CHANCE POPS IN THE SE.
SLOW EVOLVING FLOW PATTERN GRADUALLY TAKES RIDGE AXIS EASTWARD AS
TROUGH OVER THE CENTRAL PORTION OF THE COUNTY WEAKENS...WITH JET
STREAM RETREATING NORTHWARD AND BECOMING MORE ZONAL. THIS WILL
STRETCH A SLOWLY APPROACHING COLD FRONTAL BOUNDARY MORE W-E...AND
LIKELY REMAINING OFF TO OUR NW. WE/LL REMAIN ON THE VERY WARM AND
MUGGY SIDE OF THE FRONT IN A VERY SUMMER-LIKE PATTERN...KEEPING
DAILY SHOWER/TSTM CHANCES IN THE FORECAST. HIGHS FROM MONDAY
ONWARD WILL RANGE FROM THE UPPER 70S NORTH TO THE MID/UPPER 80S
SE...WITH MILD LOWS IN THE 60S TO AROUND 70 IN THE SE.
&&
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
A WEAK DISTURBANCE WILL PASS THROUGH THIS EVENING WHICH WILL SHIFT
THE LARGE SCALE FLOW TO THE NORTHWEST AND ALLOW FOR DRIER AIR TO
SWEEP INTO THE REGION OVERNIGHT. THE AREA OF MVFR/IFR FROM THE
CENTRAL MOUNTAINS INTO THE LAUREL HIGHLANDS WILL CONTINUE INTO THE
EVENING BEFORE GRADUALLY IMPROVING LATER THIS EVENING.
HIGH PRESSURE WILL BUILD ACROSS THE REGION FRIDAY INTO THE
WEEKEND.
OUTLOOK...
FRI-SUN...NO SIG WX EXPECTED.
MON-TUE...MAINLY VFR...MVFR POSS IN SHRA/TSRA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY MORNING
FOR PAZ004>006-010-011-017-037.
&&
$$
SYNOPSIS...GARTNER
NEAR TERM...GARTNER
SHORT TERM...GARTNER/RXR
LONG TERM...RXR/STEINBUGL
AVIATION...LA CORTE/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
359 PM EDT THU MAY 21 2015
.SYNOPSIS...
AN UNSEASONABLY COOL WEATHER PATTERN WILL CONTINUE THROUGH THE
END OF THE WEEK WITH A RATHER CHILLY START TO THE WEEKEND. A
GRADUAL WARMING TREND IS FORECAST THROUGH THE EARLY TO MIDDLE PART
OF NEXT WEEK ALONG WITH AN INCREASING RISK FOR SHOWERS AND
THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
FLOW AROUND AN AREA OF LOW PRESSURE OVER NORTH CAROLINA THIS AFTN
WILL CONTINUE TO SUPPORT A LARGE AREA OF CLOUDS ACROSS PA. RADAR
IMAGERY SHOWS THAT SHOWERS HAVE MOVED EAST OF THE STATE FOR THE
TIME BEING. HOWEVER...A SHORTWAVE CURRENTLY MOVING ACROSS THE
OHIO VALLEY WILL LIKELY HELP FIRE SOME MORE SHOWERS ACROSS THE NRN
MTNS AND LAURELS LATE THIS AFTN AND EVENING. LATEST HRRR GUIDANCE
SUGGESTS THOUGH THAT THEY SHOULD REMAIN ISOLATED IN COVERAGE.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
THE MAIN LARGE SCALE UPPER TROUGH AXIS IS PROGGED TO ROTATE
THROUGH THE ERN GREAT LAKES AND NRN NEW ENGLAND ON FRIDAY WHICH
SHOULD DRIVE A RE-ENFORCING SFC COLD FRONT THROUGH CENTRAL PA.
MODEL CONSENSUS CONTINUES TO SUGGEST ISOLD/WDLY SCT SHOWERS WITH
THE FRONTAL PASSAGE BUT WITH VERY LIMITED MSTR KEPT POPS AOB 20
PCT. MAX TEMPS SHOULD MODERATE SOME BUT STILL AVG BELOW NORMAL
FOR THIS TIME OF YEAR.
BEHIND THE COLD FRONT ACROSS THE REGION...A SPRAWLING AREA OF
HIGH PRESSURE /1030MB+/ WILL BUILD UNDER A DEVELOPING LARGE UPPER
RIDGE OVER THE REGION. A REINFORCING SHOT OF COLDER AIR AHEAD OF
RIDGE AXIS WILL BRING QUITE CHILLY TEMPS FOR SAT MORNING...WHERE A
FREEZE IS LOOKING MORE LIKELY ACROSS MUCH OF THE NORTHERN MTNS. A
/WELL COORDINATED/ FREEZE WATCH REMAINS IN EFFECT THERE...WITH
SCT FROST EXTENDING INTO THE LAUREL HIGHLANDS AND PORTIONS OF THE
CENTRAL MTNS. POTENTIAL FLY IN THE OINTMENT COULD BE THE
WINDS...THOUGH LIGHT...REMAINING JUST HIGH ENOUGH TO KEEP TEMPS
FROM BOTTOMING OUT COMPLETELY.
THE COLD AIR IS QUICKLY REPLACED BY MODERATING TEMPS ON SAT...AS
HIGHS REBOUND INTO THE 60S UNDER FULL SUN. NOT QUITE AS CHILLY FOR
SAT NIGHT WITH LOWS SETTLING BACK INTO THE 40S IN MOST
LOCALES...UPPER 30S POSS IN THE NW MTNS.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
SUNDAY MARKS BEGINNING OF A ROBUST WARM-UP THAT WILL CONTINUE
THROUGH NEXT WEEK. ALL GUIDANCE SIGNALS THIS WARMING TREND...WITH
HIGH CONFIDENCE IN ABOVE NORMAL TEMPERATURES BY MEMORIAL DAY AS
ANOMALOUS 500MB RIDGE BUILDS OVER THE EASTERN U.S.
SOME DIFFERENCES ON PLACEMENT OF A WARM FRONTAL ZONE LIFTING NWD
FROM THE SRN PLAINS/LWR MS VLY WHICH WILL HAVE IMPACTS ON PCPN
RISK EARLY NEXT WEEK...THOUGH BEST DAILY POPS /HIGH CHANCE TO LOW
LIKELY/ WILL BE OVER THE NW WITH CHANCE POPS IN THE SE.
SLOW EVOLVING FLOW PATTERN GRADUALLY TAKES RIDGE AXIS EASTWARD AS
TROUGH OVER THE CENTRAL PORTION OF THE COUNTY WEAKENS...WITH JET
STREAM RETREATING NORTHWARD AND BECOMING MORE ZONAL. THIS WILL
STRETCH A SLOWLY APPROACHING COLD FRONTAL BOUNDARY MORE W-E...AND
LIKELY REMAINING OFF TO OUR NW. WE/LL REMAIN ON THE VERY WARM AND
MUGGY SIDE OF THE FRONT IN A VERY SUMMER-LIKE PATTERN...KEEPING
DAILY SHOWER/TSTM CHANCES IN THE FORECAST. HIGHS FROM MONDAY
ONWARD WILL RANGE FROM THE UPPER 70S NORTH TO THE MID/UPPER 80S
SE...WITH MILD LOWS IN THE 60S TO AROUND 70 IN THE SE.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
FLOW AROUND AN AREA OF LOW PRESSURE OVER NORTH CAROLINA THIS AFTN
WILL CONTINUE TO SUPPORT A LARGE AREA OF CLOUDS ACROSS PA. MOST
OF THE CIGS ARE...AND WILL REMAIN VFR...BUT UPSLOPE FLOW IS
CAUSING SOME LOWERED CIGS AT KAOO AND KUNV AND IFR AT KJST.
SHOWERS HAVE MOVED EAST OF THE STATE FOR THE TIME BEING.
HOWEVER...A SHORTWAVE MOVING ACROSS THE OHIO VALLEY WILL LIKELY
HELP FIRE SOME MORE SHOWERS ACROSS THE WRN AND NRN MTNS LATE THIS
AFTN AND EVENING....THOUGH THEY SHOULD REMAIN ISOLATED IN
COVERAGE.
IMPROVING FLYING CONDS ARE EXPECTED LATER THIS EVENING...AS WINDS
SHIFT TO THE NW...DRAWING DRIER AIR AND CLEARING SKIES INTO THE
REGION.
HIGH PRESSURE WILL BUILD ACROSS THE REGION FRIDAY INTO THE
WEEKEND.
OUTLOOK...
FRI-SUN...NO SIG WX EXPECTED.
MON-TUE...MAINLY VFR...MVFR POSS IN SHRA/TSRA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY MORNING
FOR PAZ004>006-010-011-017-037.
&&
$$
SYNOPSIS...GARTNER
NEAR TERM...GARTNER
SHORT TERM...GARTNER/RXR
LONG TERM...RXR/STEINBUGL
AVIATION...FITZGERALD/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
308 PM EDT THU MAY 21 2015
.SYNOPSIS...
AN UNSEASONABLY COOL WEATHER PATTERN WILL CONTINUE THROUGH THE
END OF THE WEEK WITH A RATHER CHILLY START TO THE WEEKEND. A
GRADUAL WARMING TREND IS FORECAST THROUGH THE EARLY TO MIDDLE PART
OF NEXT WEEK ALONG WITH AN INCREASING RISK FOR SHOWERS AND
THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
FLOW AROUND AN AREA OF LOW PRESSURE OVER NORTH CAROLINA THIS AFTN
WILL CONTINUE TO SUPPORT A LARGE AREA OF CLOUDS ACROSS PA. RADAR
IMAGERY SHOWS THAT SHOWERS HAVE MOVED EAST OF THE STATE FOR THE
TIME BEING. HOWEVER...A SHORTWAVE CURRENTLY MOVING ACROSS THE
OHIO VALLEY WILL LIKELY HELP FIRE SOME MORE SHOWERS ACROSS THE NRN
MTNS AND LAURELS LATE THIS AFTN AND EVENING. LATEST HRRR GUIDANCE
SUGGESTS THOUGH THAT THEY SHOULD REMAIN ISOLATED IN COVERAGE.
&&
.SHORT TERM /FRIDAY...
THE MAIN LARGE SCALE UPPER TROUGH AXIS IS PROGGED TO ROTATE
THROUGH THE ERN GREAT LAKES AND NRN NEW ENGLAND ON FRIDAY WHICH
SHOULD DRIVE A RE-ENFORCING SFC COLD FRONT THROUGH CENTRAL PA.
MODEL CONSENSUS CONTINUES TO SUGGEST ISOLD/WDLY SCT SHOWERS WITH
THE FRONTAL PASSAGE BUT WITH VERY LIMITED MSTR KEPT POPS AOB 20
PCT. MAX TEMPS SHOULD MODERATE SOME BUT STILL AVG BELOW NORMAL
FOR THIS TIME OF YEAR.
BEHIND THE COLD FRONT...A SPRAWLING AREA OF HIGH PRESSURE WILL
BUILD INTO THE REGION STARTING FRIDAY NIGHT. NO SIGNIFICANT ACTIVE
WEATHER IS EXPECTED.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
CONFIDENCE CONTINUES TO INCREASE FOR AREAS OF FROST ALONG THE
ALLEGHENY FRONT BY SATURDAY MORNING. COULD EVEN SEE SOME FROST IN
THE OUTLYING AREAS AROUND STATE COLLEGE. WITH A FAVORABLE PATTERN
AND SUPPORT FROM MODEL CONSENSUS...COLLABORATED WITH BUF/BGM ON A
FREEZE WATCH FOR THE NRN MTNS WITH FCST MINS IN THE 28-32F RANGE.
WILL ALSO CONTINUE TO HIGHLIGHT FROST RISK IN THE HWO AND LATER
SHIFTS CAN ADD FROST HEADLINES AS NEEDED.
ALL GUIDANCE CONTINUES TO SIGNAL A WARMING TREND INTO THE MIDDLE
OF NEXT WEEK...WITH HIGH CONFIDENCE IN ABOVE NORMAL TEMPERATURES
BY MEMORIAL DAY AS ANOMALOUS 500MB RIDGE BUILDS OVER THE EASTERN
U.S. GFS/ECMWF DISAGREE ON PLACEMENT OF WARM FRONTAL ZONE LIFTING
NWD FROM THE SRN PLAINS/LWR MS VLY. THIS WILL LKLY IMPACT PCPN
RISK EARLY NEXT WEEK. A COLD FRONT IS PROGGED TO APPROACH THE AREA
LATER IN THE WEEK. WITH LOW CONFIDENCE IN BOUNDARY PLACEMENT AT
THIS RANGE...WILL MAINTAIN DAILY RISK OF MAINLY AFTERNOON
THUNDERSTORMS GIVEN INCREASINGLY HUMID/MUGGY SUMMER-LIKE PATTERN.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
FLOW AROUND AN AREA OF LOW PRESSURE OVER NORTH CAROLINA THIS AFTN
WILL CONTINUE TO SUPPORT A LARGE AREA OF CLOUDS ACROSS PA. MOST
OF THE CIGS ARE...AND WILL REMAIN VFR...BUT UPSLOPE FLOW IS
CAUSING SOME LOWERED CIGS AT KAOO AND KUNV AND IFR AT KJST.
SHOWERS HAVE MOVED EAST OF THE STATE FOR THE TIME BEING.
HOWEVER...A SHORTWAVE MOVING ACROSS THE OHIO VALLEY WILL LIKELY
HELP FIRE SOME MORE SHOWERS ACROSS THE WRN AND NRN MTNS LATE THIS
AFTN AND EVENING....THOUGH THEY SHOULD REMAIN ISOLATED IN
COVERAGE.
IMPROVING FLYING CONDS ARE EXPECTED LATER THIS EVENING...AS WINDS
SHIFT TO THE NW...DRAWING DRIER AIR AND CLEARING SKIES INTO THE
REGION.
HIGH PRESSURE WILL BUILD ACROSS THE REGION FRIDAY INTO THE
WEEKEND.
OUTLOOK...
FRI-SUN...NO SIG WX EXPECTED.
MON-TUE...MAINLY VFR...MVFR POSS IN SHRA/TSRA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY MORNING
FOR PAZ004>006-010-011-037.
&&
$$
SYNOPSIS...GARTNER
NEAR TERM...GARTNER
SHORT TERM...GARTNER/STEINBUGL
LONG TERM...STEINBUGL
AVIATION...FITZGERALD/GARTNER
AREA FORECAST DISCUSSION
NWS AMARILLO TX
354 PM CDT THU MAY 21 2015
.SHORT TERM...
MUCH OF THE TEXAS PANHANDLE HAS SEEN NEARLY 48 HOURS OF OVERCAST SKY
CONDITIONS IN THE WAKE OF A COLD FRONT THAT PASSED THROUGH TUESDAY
EVENING. DESPITE THE DIFFERENTIAL ADVECTION PROFILE SEEN IN THE
12Z SOUNDING...MOISTURE WAS QUITE DEEP EVEN EXTENDING ABOVE THE
EAST-NORTHEASTERLY LOW LEVEL FLOW TO NEAR 700 MB WHERE FLOW WAS MORE
SOUTHWESTERLY. VISIBLE SATELLITE SHOWS SOME BREAKS IN THE NORTHEAST
TEXAS PANHANDLE AND THE EASTERN OKLAHOMA PANHANDLE THIS AFTERNOON
AND THIS HAS BEEN COINCIDENT WITH WARMER TEMPERATURES IN THE LOWER
60S. FURTHER WEST TEMPERATURES HAVE YET TO RISE OUT OF THE 50S AND
SO A SHORT TERM UPDATE WAS SENT TO LOWER TEMPERATURES SLIGHTLY. OUR
RECORD LOW MAX TEMPERATURE FOR TODAY IS 56 SET IN 1900. BASED ON
CURRENT TRENDS IN THE OBSERVATIONS AND EXAMINING THE DIURNAL CURVE
FROM YESTERDAY UNDER SIMILAR CONDITIONS...WE SHOULD REACH OR
SLIGHTLY EXCEED THIS TEMPERATURE THIS AFTERNOON.
SHORT RANGE GUIDANCE AGREES ON TIMING OF ONSET OF DEEPER SATURATION
SEEN ON ISENTROPIC SURFACES. THIS IS CAUSING SOME CONVECTION IN
EASTERN NEW MEXICO EXTENDING EAST TO JUST ACROSS THE TEXAS STATE
LINE...NEAR BOVINA. THIS ACTIVITY SHOULD CONTINUE MOVING
NORTHEASTWARD THIS AFTERNOON WHILE EXPANDING AS ASCENT FROM
APPROACHING LEAD WAVE STRENGTHENS. GIVEN THE SHORT RANGE MODEL
AGREEMENT ON THE LARGE SCALE BELIEVE THIS IS A FAIRLY GOOD CASE FOR
SUCCESS OF CONVECTION ALLOWING MODELS WITH TIMING AND COVERAGE OF
PRECIPITATION THIS EVENING AND INTO THE NIGHT. HOURLY PROBABILITY OF
PRECIPITATION GRIDS FOLLOW THESE MODELS INCLUDING THE HRRR AND
TTU-WRF FAIRLY CLOSELY. MOST OF THE PRECIPITATION SHOULD EXIT THE
AREA EARLY TOMORROW MORNING. SUBSIDENCE/MID LEVEL HEIGHT RISES IN
THE WAKE OF THE LEAD SHORTWAVE AND PRECEDING THE CLOSED UPPER LOW
SHOULD LIMIT OPPORTUNITY FOR CONVECTION TOMORROW AFTERNOON. HAVE
SIGNIFICANT REDUCED PRECIPITATION PROBABILITIES FOR TOMORROW
AFTERNOON. MODEL FORECAST SOUNDINGS REVEAL DIFFERENCES IN MODELS
WITH HOW MOIST THE LOW LEVELS ARE AND THIS HAS IMPLICATIONS FOR BOTH
CLOUD COVER AND TEMPERATURES. THE NAM HAS GENERALLY PERFORMED WELL
THE DAY FOLLOWING A NIGHTTIME CONVECTIVE EVENT RECENTLY SO GAVE IT
SOME CREDIT BUT TOOK A BLENDED APPROACH BETWEEN THE DRIER/WARMER NAM
AND THE MOIST/COOL GFS AND ECMWF. QPF GRIDS WERE ADJUSTED SLIGHTLY
AND DEVIATE ONLY SLIGHTLY FROM WPC GUIDANCE...MAINLY IN JUST A
TEMPORAL SENSE BUT WITH SLIGHTLY HIGHER AMOUNTS. TOTALS THROUGH
TOMORROW RANGE FROM AROUND A HALF INCH IN THE NORTHWEST TO NEAR AN
INCH IN THE SOUTHEAST.
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY
SPLIT FLOW UPPER AIR PATTERN WILL MAINTAIN A WET AND ACTIVE WEATHER
PATTERN FOR THE EXTENDED PERIOD AS A SERIES OF UPPER LEVEL
DISTURBANCES PASS ACROSS THE SOUTHERN PLAINS.
A PACIFIC UPPER LOW WILL MOVE ACROSS THE GREAT BASIN AREA FRIDAY
EVENING...WITH A LEAD SHORTWAVE EJECTING OUT OF THIS SYSTEM BEFORE
MOVING OVER THE REGION LATE FRIDAY NIGHT. LOW-LEVEL MOISTURE WILL
REMAIN PLENTIFUL COURTESY OF PERSISTENT SOUTHEAST UPSLOPE SURFACE FLOW
AND A LIFTING WARM FRONT. WITH THE DRYLINE REMAINING IN EASTERN NM
LARGE SCALE ASCENT WILL BE THE PRIMARY FOCUS FOR CONVECTION
INITIATION FRIDAY EVENING...WITH THE HIGHEST CHANCES FOR PRECIP
OCCURRING BETWEEN 06-12Z SATURDAY. HIGH PW VALUES...NEAR THE 99TH
PERCENTILE...WILL SUPPORT MODERATE TO HEAVY RAINFALL. THIS IN TURN
RAISES CONCERN FOR THE FLOODING POTENTIAL PARTICULARLY OVER THE
SOUTHEAST TEXAS PANHANDLE WHERE RAINFALL TOTALS OVER 2 INCHES
OCCURRED OVER THE PAST 3 DAYS AND SOILS ARE MORE CONDUCIVE TO
FLOODING. DID CONTEMPLATE EXPANDING THE CURRENT FLASH FLOOD WATCH
FURTHER WESTWARD GIVEN ALL THE RAIN THE SOUTHERN TEXAS PANHANDLE HAS
RECEIVED RECENTLY. DECIDED TO HOLD OFF ON EXPANDING THE WATCH AS
CONFIDENCE IS NOT HIGH ENOUGH THAT ENOUGH RAINFALL WILL RESULT IN
FLASH FLOODING.
THE UPPER LOW WILL MOVE INTO THE FOUR CORNERS REGION SATURDAY EVENING
AND LIFT SLOWLY TO THE NORTHEAST SUNDAY. SEVERAL UPPER LEVEL
SHORTWAVE TROUGHS WILL MAINTAIN A THREAT OF SHOWERS AND THUNDERSTORMS
THROUGH THE HOLIDAY WEEKEND. THE DRYLINE WILL MIX A BIT FURTHER
EASTWARD SUNDAY...WHICH WILL FOCUS STORM INITIATION GENERALLY OVER
THE EASTERN PANHANDLES. IN GENERAL NOT EXPECTING MUCH IN THE WAY OF
SEVERE WEATHER ALTHOUGH POSSIBLE IF THERE IS ENOUGH DAYTIME
DESTABILIZATION...SOME STRONG TO SEVERE STORMS WILL BE POSSIBLE.
MAY SEE A BRIEF BREAK IN THE RAIN EARLY NEXT WEEK ALTHOUGH WITH THE
MEDIUM RANGE MODELS IN DISAGREEMENT IN THE SPEED OF THE UPPER
TROUGH...HELD ONTO SLIGHT CHANCE POPS MEMORIAL DAY. DECENT LOW-LEVEL
MOISTURE IN PLACE AND ANOTHER UPPER DISTURBANCE MOVING THROUGH THE
FOUR CORNERS REGION CAN GENERATE MORE SHOWERS AND THUNDERSTORMS
MIDWEEK.
CLK
&&
.PRELIMINARY POINT TEMPS/POPS...
AMARILLO TX 48 67 57 71 56 / 80 40 60 60 20
BEAVER OK 48 67 57 71 58 / 80 50 40 60 40
BOISE CITY OK 46 70 54 72 51 / 70 30 40 30 20
BORGER TX 50 68 59 72 59 / 80 50 50 50 30
BOYS RANCH TX 49 71 58 74 56 / 80 40 60 50 20
CANYON TX 48 67 57 72 55 / 70 40 60 50 20
CLARENDON TX 49 66 58 70 58 / 80 50 50 70 40
DALHART TX 46 70 54 73 53 / 70 30 50 50 20
GUYMON OK 47 69 57 72 56 / 80 50 40 50 20
HEREFORD TX 47 68 57 73 55 / 70 40 70 40 20
LIPSCOMB TX 49 65 58 69 59 / 80 50 40 70 40
PAMPA TX 47 64 56 69 57 / 80 50 50 60 40
SHAMROCK TX 51 65 59 69 59 / 80 50 50 70 50
WELLINGTON TX 53 67 61 71 61 / 80 50 50 70 50
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...FLASH FLOOD WATCH FROM LATE FRIDAY NIGHT THROUGH LATE SATURDAY
NIGHT FOR THE FOLLOWING ZONES: ARMSTRONG...COLLINGSWORTH...
DONLEY...GRAY...WHEELER.
OK...NONE.
&&
$$
17/05
AREA FORECAST DISCUSSION
NWS EL PASO TX/SANTA TERESA NM
210 PM MDT THU MAY 21 2015
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE AREA THIS
AFTERNOON AND EVENING...INTERACTING WITH A STALLED OUT FRONTAL
BOUNDARY AND LOW LEVEL MOISTURE OVER SOUTH-CENTRAL NEW MEXICO AND
FAR WEST TEXAS. THIS WILL RESULT IN ISOLATED TO SCATTERED
THUNDERSTORMS DEVELOPING THIS AFTERNOON EAST OF THE CONTINENTAL
DIVIDE...SPREADING INTO THE RIO GRANDE VALLEY BY EARLY EVENING. A
FEW STORMS WILL BE SEVERE...PRODUCING DAMAGING WIND AND LARGE
HAIL. DRY SOUTHWEST FLOW WILL PREVAIL THROUGH THE WEEKEND.
&&
.DISCUSSION...
MAIN CONCERN IS SEVERE WEATHER POTENTIAL THIS AFTERNOON AND
EVENING. AS IS OFTEN THE CASE...BACKDOOR COLD FRONT PUSHED FURTHER
WEST OVERNIGHT THAN ORIGINALLY PROGGED...AND LOW CLOUD COVER HAS
HELPED LIMIT THE EASTWARD RETROGRESSION. QUASI-STATIONARY FRONT
CURRENTLY EXTENDS FROM THE EAST SLOPES OF THE BLACK RANGE TO
RIGHT AROUND DEMING AND COLUMBUS. RADAR THIN LINE EXTENDS FROM
JUST SE OF COLUMBUS ESE TO SAMALAYUCA...AND THIS IS LIKELY THE
FRONT. FROM THERE IT IS LIKELY BANKED UP AGAINST HIGHER TERRAIN SW
OF THE RIO GRANDE.
MEANWHILE...SHORTWAVE TROUGH IS SHARPLY DEFINED ON WATER VAPOR
IMAGERY ENTERING FAR SW NEW MEXICO...SOME MID-LEVEL CLOUDS AND VIRGA
ASSOCIATED WITH THIS FEATURE ARE ALSO APPARENT ON VISIBLE
SATELLITE AND RADAR IMAGERY RESPECTIVELY.
JUST NOW STARTING TO SEE CONVECTION INITIATE ALONG THE BLACK RANGE
AND PARTS OF SIERRA COUNTY. EXPECT CELLS TO DEVELOP FURTHER TO THE
SOUTH WITHIN INSTABILITY PLUME ALONG THE FRONT IN THE NEXT HOUR.
SEVERAL WRF RUNS AND HRRR SEEM TO BE HANDLING THE SITUATION WELL
DUE TO WELL- DEFINED BOUNDARIES AND CLEAR UPPER LEVEL FORCING.
EXPECT STORMS TO LIGHT UP ALONG THE FRONT AND MOVE
EASTWARD...INITIALLY ALONG THE BLACK RANGE INTO EASTERN LUNA
COUNTY...THEN SHIFTING EASTWARD TOWARDS THE RIO GRANDE BETWEEN 4
PM AND 6 PM AS LOW CLOUDS CONTINUE TO BREAK UP AND DESTABILIZATION
OCCURS BEHIND THE FRONT.
EXCELLENT DEEP LAYER SHEAR IS PRESENT FOR ROTATING UPDRAFTS...WITH
0-6KM SHEAR AOA 60 KNOTS AND 40 KNOTS IN THE 0-3KM LAYER. WET BULB
ZERO VALUES AROUND 12KFT MSL SUGGEST LARGE HAIL POSSIBLE...BUT
MODEL SOUNDINGS INDICATE MID-LEVEL LAPSE RATES IN THE -10 TO -20 C
LAYER ARE NOT TERRIBLY STEEP...WHICH IS A LIMITING FACTOR. SFC-
BASED CAPE VALUES WILL GENERALLY RUN FROM 1000-1500 J/KG IN THE
MAIN INSTABILITY AXIS ALONG THE FRONT.
MAIN THREATS WILL BE DAMAGING WINDS...LARGE HAIL (BUT LIKELY ON
THE LOWER END OF SEVERE CRITERIA DUE TO LIMITED LAPSE RATES). LCL
HEIGHTS AROUND 7000 FT MSL ARE A LITTLE LOW FOR AROUND THESE
PARTS...BUT LOW-LEVEL SPEED SHEAR IN THE 0-1KM LAYER IS LIMITED.
STILL...A QUICK-SPINUP FUNNEL IS OUT OF THE QUESTION ESPECIALLY IN
RAPIDLY DEVELOPING CELLS EARLY ON.
PW VALUES AT OR AROUND AN INCH ALONG THE RIO GRANDE SUGGESTS HEAVY
DOWNPOURS POSSIBLE...BUT A STEADY STORM MOTION SHOULD LIMIT FLASH
FLOOD THREAT TO LOCALIZED/POOR DRAINAGE AREAS WHERE RAINFALL RATES
ARE MORE OF AN ISSUE.
EXPECT THUNDERSTORM THREAT WILL DIMINISH QUICKLY AFTER 10PM WITH
LACK OF UPPER LEVEL SUPPORT...BUT A FEW ISOLATED STORMS WILL
REMAIN POSSIBLE THROUGH THE NIGHT EAST OF THE RIO GRANDE.
LOW LEVEL MOISTURE WILL AGAIN PUSH WELL WEST OF THE RIO GRANDE
OVERNIGHT... MAINLY AIDED BY CONVECTIVE OUTFLOW...BUT IT WILL BE
RAZOR-THIN AND QUICKLY MIX OUT TO THE EAST. STILL...THE LOW LEVEL
MOISTURE WILL NOT BE FAR TO OUR EAST THROUGH THE WEEKEND...AND A
SPOT SHOWER OR THUNDERSTORM IS NOT OUT OF THE QUESTION IN FAR
EASTERN HUDSPETH OR OTERO COUNTIES.
ELSEWHERE...DRY SOUTHWEST FLOW WILL PREVAIL THROUGH THE WEEKEND AS
THE MAIN UPPER LOW OFF CALIFORNIA MOVES TO THE EAST. TEMPERATURES
WILL MAINLY BE IN THE LOWER AND MID-80S ACROSS THE LOWLANDS
THROUGH THE WEEKEND...WITH A WARM-UP TOWARDS THE MIDDLE OF NEXT WEEK.
SOUTHEAST LOW LEVEL FLOW MAY BRING THE THUNDERSTORM THREAT BACK TO
THE RIO GRANDE BY WEDNESDAY.
&&
.AVIATION...VALID 22/00Z-23/00Z...
BACKDOOR FRONT HAS PUSHED WESTWARD TO CONTINENTAL DIVIDE: TIL 06Z
WINDS 120-160/13G23KTS SCT-BKN040 SCT-BKN100-140 SCT-BKN200-250
ISOLD TO SCT AREAS BKN020 BKN040 OVC-70 3SM -TSRAGS. 06Z-15Z:
SCT040-060 SCT100-140 SCT 200-250 WINDS 120/10KTS...AFT 15Z:
FEW-SCT070 FEW-SCT150. WINDS 23015G25KTS. LGT TO MDT MECHANICAL
TURBC OVR/NR MTNS BLO 15K FT MSL.
&&
.FIRE WEATHER...
A SURGE OF MOISTURE FROM THE EAST WILL RESULT IN SCATTERED SHOWERS
AND THUNDERSTORMS TODAY AND TONIGHT GENERALLY EAST OF A TCS-DMN LINE.
A FEW OF STORMS WILL BE STRONG WITH LARGER HAIL AND WIND GUSTS UP TO
50 MPH. THE INCREASED CLOUDS WILL AND RAIN WILL KEEP TEMPERATURES
BELOW NORMAL FOR MOST AREAS TODAY. HOWEVER THE EXTREME SOUTHWEST
CORNER OF THE NMEX BOOT HEEL MAY SEE NEAR CRITICAL FIRE WX
CONDITIONS THIS AFTN IN A SMALL AREA NEAR/ON THE AZ BORDER BUT
GENERALLY NOT MEETING TIME REQUIREMENTS FOR RED FLAG. DRY AND WINDY
CONDITIONS WILL RETURN ON FRIDAY WITH WARMER TEMPERATURES EXPECTED.
RED FLAG CONDITIONS SHOULD BE MEET IN ZONE 11 AND NEAR RED FLAG IN
OTHER LOWLANDS. BREEZY TO WINDY CONDITIONS WILL CONTINUE THROUGH THE
WEEKEND AS A LOW PRESSURE SYSTEM PASSES NORTH OF THE LOCAL AREA. DRY
CONDITIONS WITH SEASONAL TEMPERATURES WILL OCCUR MEMORIAL DAY AND
THE FIRST PART OF NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
EL PASO 59 88 62 84 58 / 30 0 0 0 0
SIERRA BLANCA 57 85 61 82 53 / 40 10 10 10 0
LAS CRUCES 50 84 50 79 50 / 30 0 0 0 0
ALAMOGORDO 52 83 53 80 51 / 50 0 0 0 0
CLOUDCROFT 38 59 39 55 39 / 50 10 10 0 0
TRUTH OR CONSEQUENCES 53 80 50 77 49 / 30 0 0 0 0
SILVER CITY 44 75 43 66 43 / 0 0 0 0 0
DEMING 47 83 46 78 47 / 10 0 0 0 0
LORDSBURG 44 82 45 74 46 / 0 0 0 0 0
WEST EL PASO METRO 60 88 62 83 57 / 30 0 0 0 0
DELL CITY 51 85 56 82 51 / 50 10 10 0 0
FORT HANCOCK 59 90 63 87 56 / 30 0 0 0 0
LOMA LINDA 53 80 58 75 53 / 40 0 0 0 0
FABENS 56 89 59 85 55 / 30 0 0 0 0
SANTA TERESA 53 88 56 82 53 / 30 0 0 0 0
WHITE SANDS HQ 58 83 57 79 54 / 30 0 0 0 0
JORNADA RANGE 46 82 48 78 46 / 30 0 0 0 0
HATCH 51 83 49 78 48 / 30 0 0 0 0
COLUMBUS 53 81 52 77 51 / 0 0 0 0 0
OROGRANDE 55 84 57 80 54 / 40 0 0 0 0
MAYHILL 43 67 46 65 44 / 50 10 10 0 0
MESCALERO 41 69 42 66 42 / 50 10 10 0 0
TIMBERON 43 68 44 64 44 / 50 10 10 0 0
WINSTON 42 71 41 67 42 / 20 0 0 0 0
HILLSBORO 45 79 45 76 46 / 20 0 0 0 0
SPACEPORT 48 82 45 78 46 / 30 0 0 0 0
LAKE ROBERTS 43 73 41 66 41 / 10 0 0 0 0
HURLEY 42 75 42 69 43 / 0 0 0 0 0
CLIFF 43 79 43 73 44 / 0 0 0 0 0
MULE CREEK 38 76 35 71 38 / 0 0 0 0 0
FAYWOOD 45 76 44 71 45 / 10 0 0 0 0
ANIMAS 46 80 45 76 47 / 0 0 0 0 0
HACHITA 46 84 44 78 46 / 0 0 0 0 0
ANTELOPE WELLS 46 83 43 79 46 / 0 0 0 0 0
CLOVERDALE 46 76 43 73 45 / 0 0 0 0 0
&&
.EPZ WATCHES/WARNINGS/ADVISORIES...
NM...FIRE WEATHER WATCH FROM FRIDAY AFTERNOON THROUGH FRIDAY EVENING
FOR NMZ111.
TX...NONE.
&&
$$
25-HARDIMAN / 20-NOVLAN
AREA FORECAST DISCUSSION
NWS SEATTLE WA
330 PM PDT THU MAY 21 2015
.SYNOPSIS...SHOWERS AND THUNDERSTORMS ARE OVER THE MOUNTAINS THIS
AFTERNOON AND A FEW COULD SPREAD TO THE LOWLANDS THIS EVENING. LOW
CLOUDS ON THE COAST WILL PUSH INLAND OVERNIGHT. FRIDAY AND SATURDAY
WILL BE COOLER WITH A CHANCE OF SHOWERS OVER THE INTERIOR OF WESTERN
WASHINGTON AND THE CASCADES. A PATTERN OF MORNING CLOUDS WITH SOME
AFTERNOON SUNSHINE IS LIKELY NEXT WEEK WITH A CONTINUING CHANCE OF
SHOWERS IN THE MOUNTAINS.
&&
.SHORT TERM...SCATTERED SHOWERS AND THUNDERSTORMS OVER THE MOUNTAINS
THIS AFTERNOON MAY SPREAD TO PORTIONS OF THE LOWLANDS THIS EVENING.
THE HRRR CONTINUES TO SHOW THE BEST CHANCE OF SHOWERS FOR THE
LOWLANDS IS OVER SW WA. MARINE STRATUS ON THE COAST WILL SPREAD
INLAND OVERNIGHT AND MARINE AIR SHOULD CONTINUE TO PUSH INTO WRN WA
THROUGH FRIDAY FOR A COOLER DAY. A CHANCE OF SHOWERS MIGHT PERSIST
FRIDAY THROUGH SATURDAY AS A WEAK UPPER LOW DROPS OVER THE AREA.
HIGHS WILL BE IN THE 60S AND THE BEST CHANCE FOR SHOWERS WILL BE
OVER THE CASCADES.
.LONG TERM...ANOTHER WEAK UPPER LOW WILL REMAIN OVER THE REGION
SUNDAY THROUGH WEDNESDAY WITH CONTINUED MODERATE LOW LEVEL ONSHORE
FLOW. MOST DAYS SHOULD SEE MORNING CLOUDS WITH SOME AFTERNOON
SUNSHINE OVER THE INTERIOR. THE COAST WILL PROBABLY STAY CLOUDY AND
COOL EACH DAY. THERE WILL BE A CHANCE OF SHOWERS...MAINLY IN THE
MOUNTAINS EACH AFTERNOON AND EVENING HOURS. THE POSITION OF THE LOW
CHANGES FROM RUN TO RUN AND SO IT IS HARD TO SAY IF THE LOWLANDS
WILL SEE ANY SHOWERS...BUT THE NORTH CASCADES PROBABLY HAVE THE BEST
CHANCE OF SHOWERS AND COULD SEE A SOAKING RAIN OR TWO IF THE LOW
BRINGS MOISTURE WWD FROM EASTERN WA...WHICH SOME MODELS RUNS HAVE
SHOWN.
&&
.AVIATION...AN UPPER LOW OVER THE CENTRAL COAST OF BRITISH COLUMBIA
IS FORECAST TO SLOWLY DIG S THRU TONIGHT. THE FLOW ALOFT WILL
GENERALLY BE LIGHT SLY. THE AIR MASS WAS UNSTABLE OVER THE MTNS THIS
AFTERNOON. THERE IS A CHANCE THAT AN ISOLATED TSTM COULD DRIFT OVER
THE LOWLANDS LATE TODAY OR EARLY THIS EVENING. THE LOWLAND AREAS
THAT WILL HAVE THE GREATEST CHANCE WILL BE E OF A KSEA-KPLU LINE AND
S OF KOLM. THE RISK OF TSTMS SHOULD END BY 0600 UTC.
MEANWHILE...THE SFC ONSHORE PRES GRADIENT CONTINUED TO TIGHTEN
THIS AFTERNOON. THIS WILL TRANSLATE TO LOW CLOUDS ACROSS THE
INTERIOR LOWLANDS FRI MORNING. ANTICIPATE WIDESPREAD IFR CIGS BY
1200 UTC. THERE WILL ALSO BE AREAS OF 1-3SM BR OR -DZ BR ON THE
COAST AFTER 0600 UTC.
KSEA...VFR CONDITIONS ARE ANTICIPATED TIL 0900 UTC. AFTER 0900
UTC...LOOK FOR CIGS IN THE 1-2K FT RANGE TO DEVELOP OVER THE
TERMINAL. CIGS SHOULD SETTLE NEAR 010 BY 1200 UTC.
&&
.MARINE...
PERSISTENT HIGH PRES OFFSHORE WITH LOWER PRES INLAND WILL RESULT
IN CONTINUED ONSHORE FLOW OF VARYING STRENGTH THROUGH TUE.
MEANWHILE...THE ONSHORE PRES GRADIENT CONTINUED TO STRENGTHEN THIS
AFTERNOON. THIS COMBINED WITH A MODEST TEMPERATURE GRADIENT
BETWEEN THE COAST /IN THE MID 50S/ AND THE INTERIOR /IN THE 70S/
THIS AFTERNOON WILL LIKELY RESULT IN GALE FORCE WINDS OVER THE
CENTRAL U.S. STRAIT OF JUAN DE FUCA THIS EVENING.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...GALE WARNING IN EFFECT TIL 5 AM FRI FOR THE CENTRAL STRAIT
OF JUAN DE FUCA.
SMALL CRAFT ADVISORIES ARE IN EFFECT FOR THE COASTAL WATERS
FROM CAPE FLATTERY TO CAPE SHOALWATER FROM 10 NM OUT TO 60
NM AND THE EAST ENTRANCE TO THE STRAIT OF JUAN DE FUCA.
&&
$$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
323 PM CDT THU MAY 21 2015
.TONIGHT - CONFIDENCE...MEDIUM
DRY AND MILD WESTERLY FLOW WILL PERSIST INTO THE EARLY EVENING
HOURS. FRONTAL BOUNDARY THEN PROGGED TO SWEEP SOUTH AND SHIFT
WINDS TO THE NE. ALREADY SEEING SOME NORTHERLY 20 KNOT PLUS GUSTS
ACRS NRN WI WITH WEAK POST FRONTAL PRESSURE RISES VCNTY U.P. SO NE
GUSTINESS EXPECTED ESPECIALLY NEAR LAKE MICHIGAN. WILL LEAVE
MENTION OF A FEW SHRA IN PARTS OF THE ERN CWA THIS EVENING. KGRB
RADAR SHOWS A FEW SHRA POPPING UP WITHIN AGITATED CU FIELD VCNTY
FRONTAL BOUNDARY. HIGH PRESSURE SETTLES IN LATER IN THE NIGHT.
.FRIDAY - CONFIDENCE...HIGH
SURFACE HIGH PRESSURE EXPECTED TO DOMINATE WITH PLENTY OF SUNSHINE AND
LIGHT WIND REGIME. ONSHORE COMPONENT WILL KEEP THE EAST COOLER. 925
TEMPS RISE TO AROUND 9C IN THE EAST AND 14C IN THE WEST...SO EXPECT
A DECENT EAST/WEST GRADIENT IN TEMPS.
.SHORT TERM...FRIDAY NIGHT THROUGH SUNDAY NIGHT.
FRIDAY NIGHT AND SATURDAY...FORECAST CONFIDENCE HIGH
SURFACE HIGH CENTERED OVER LOWER MICHIGAN SHIFTS SLOWLY TO THE
SOUTHEAST AND EXPANDS. WARMING 850 MB TEMPS AS COLD POOL MOVES EAST
WITH DEPARTING SRN CANADIAN CLOSED LOW...AND 500 MB HEIGHTS SLOWLY
RISE AS DEEPENING TROUGH MOVES INTO WESTERN U.S. WILL SEE LOWS HOLD
IN THE UPPER 40S IN THE SW THIRD...WITH LOW TO MID 40S ELSEWHERE.
SOME 700 MB MOISTURE AND OMEGA MOVE ACROSS WESTERN WI SATURDAY
AFTERNOON...BUT STRONGER Q-VECTOR CONVERGENCE STAYS TO THE WEST WITH
MORE FOCUSED 850 MB WARM AIR ADVECTION AND LOWER CONDENSATION
PRESSURE DEFICITS. SOUNDINGS ARE ALSO DRY BELOW 5K FT REFLECTING
INFLUENCE OF LOBE OF SURFACE HIGH PRESSURE EXTENDING WESTWARD OVER
SRN WI FROM BROAD HIGH CENTERED OVER THE MID-ATLANTIC STATES. NO
MORE THAN SLIGHT POPS WARRANTED AND WILL KEEP LIMITED TO THE FAR NW.
SOME DIFFERENCES IN HOW WARM 925 MB TEMPS GET SO CONSENSUS HIGHS IN
THE LOWER 70S AWAY FROM LAKE MICHIGAN LOOK GOOD WITH UPPER 60S
LAKESIDE.
SATURDAY NIGHT...FORECAST CONFIDENCE HIGH
JET SHIFTS NWD WITH UPPER RIDGING DEVELOPING OVER CENTRAL SECTIONS
OF THE COUNTRY IN RESPONSE TO DEEP FULL-LATITUDE TROUGH DIGGING INTO
THE SW U.S. PCPN CHANCES ARE PREDICATED ON TIMING OF PRECURSOR SHORT
WAVES EJECTING AHEAD OF DEEP WESTERN U.S. TROUGH AND LIFTING TOWARD
THE WESTERN GREAT LAKES IN MOIST SLY FLOW.
FIRST SHORT WAVE APPROACHES...WITH TIMING DIFFERENCES CAUSING PCPN
CHANCES THROUGH 12Z SUNDAY TO RANGE FROM KEEPING THE ENTIRE CWA
DRY/12Z GFS/...TO BRINGING PCPN INTO THE WEST OR FAR SOUTH/NAM AND
12ZECMWF/...OR OVER ALL BUT THE FAR NORTH AND EAST/12Z CANADIAN.
WILL FOLLOW CONSENSUS POPS WHICH LIMITS CHANCE POPS TO THE SOUTH
CENTRAL AND SLIGHT CHANCE ELSEWHERE WITH LESS THAN 15 PCT IN THE FAR
SOUTHEAST. LOWS WILL HOLD IN THE 50S OVERNIGHT WITH RISING 925 MB
TEMPS
SUNDAY AND SUNDAY NIGHT...FORECAST CONFIDENCE MEDIUM
ALL MODELS SWING INITIAL SHORT WAVE ACROSS SRN WI SUNDAY
MORNING...WITH ANOTHER WARM ADVECTION SURGE APPROACHING THE FAR
SOUTH BY 00Z MONDAY. HIGHER RESOLUTION VERSIONS OF GFS AND NAM
INDICATE THERE WILL PROBABLY SEE A BREAK IN THE PCPN BETWEEN THESE
TWO ROUNDS...BUT MODEL TIMING UNCERTAINTY LEADS TO POPS ALL DAY IN
THE CONSENSUS POPS. BETTER POPS SUNDAY NIGHT WITH WARM ADVECTION
SURGE. HOPEFULLY LATER RUNS WILL LEAD TO BETTER RESOLUTION TO PCPN
TIMING.
IF BREAK IN PCPN IS LONG ENOUGH...AND A BIT OF SUN CAN POP
THROUGH...COULD SEE TEMPS RISE HIGHER THAN UPPER 60S TO LOWER 70S
WITH FORECAST 925 MB TEMPS. INSTABILITY IN SOUNDINGS NOT THAT
IMPRESSIVE SO WILL LIMIT CHANCES OF THUNDER. LOWS WILL ONLY COOL
INTO THE UPPER 50S TO AROUND 60 NEAR THE IL BORDER.
.LONG TERM...MONDAY THROUGH THURSDAY...FORECAST CONFIDENCE MEDIUM
AN UNSETTLED AND WET PERIOD IN OVERALL SWLY MID TO UPPER LEVEL FLOW
AS WESTERN TROUGH MOVES OUT INTO THE PLAINS MONDAY...AND THEN
DAMPENS AS IT CROSSES THE UPPER MIDWEST TUESDAY AND IS ABSORBED INTO
A CLOSED LOW OVER HUDSON BAY. MOIST SRLY SURFACE FLOW CONTINUES AS
SURFACE LOW PASSES BY TO THE WEST AND NORTH OF THE STATE. GFS AND
ECMWF BRING ANOTHER SURGE OF MOISTURE WITH A SHORT WAVE TUESDAY
NIGHT...WITH THE GFS DEVELOPING A SURFACE LOW THAT MOVES RIGHT ACROSS
THE STATE WEDNESDAY. ECMWF DRIES AREA OUT WEDNESDAY INTO
THURSDAY...WITH ANOTHER WAVE MOVING IN FOR THURSDAY AFTERNOON/NIGHT.
GFS KEEPS AREA DRY ONCE PCPN ENDS WEDNESDAY EVENING. RESULT IS
CHANCE POPS THROUGH THE EXTENDED WITH BLENDED SOLUTION. LOOKING FOR
ABOVE NORMAL TEMPERATURES THROUGH THE EXTENDED.
&&
.AVIATION/00Z TAFS/...VFR THIS PERIOD WITH WESTERLY SURFACE FLOW
AHEAD OF FRONT DROPPING SOUTHWARD FROM NRN WI. PREFER THE DRIER LOOK
OF THE HRRR WITH RESPECT TO PRECIP COVERAGE. LATEST GUIDANCE
SUGGESTS FRONT DROPS THROUGH TAF SITES BETWEEN 01Z-03Z. BRIEF PERIOD
OF GUSTY NE WINDS POSSIBLE. HAVE ALSO KEPT THE EVENING POPS WITH
THIS FEATURE AS WELL. NAM/RAP SOUNDINGS SHOW LITTLE POTENTIAL FOR
POST FRONTAL MVFR CIGS. QUIET HIGH PRESSURE DOMINATES FOR FRIDAY.
&&
.MARINE...A COLD FRONT WILL RACE DOWN THE LAKE EARLY THIS
EVENING...REACHING SHEBOYGAN AROUND 7 PM AND KENOSHA BY 9-10PM THIS
EVENING. WINDS WILL SHIFT ABRUPTLY FROM WESTERLY TO NORTHEAST AND
MAY GUST TO AROUND 20KTS POST FROPA FOR A TIME BEFORE SETTLING BACK
DOWN.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TONIGHT/FRIDAY AND AVIATION/MARINE...COLLAR
FRIDAY NIGHT THROUGH THURSDAY...REM