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
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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 VISIT US AT WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA
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 FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA
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 FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA
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 VISIT US AT WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA
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