Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/24/13
AREA FORECAST DISCUSSION
NWS NEW YORK NY
435 PM EDT WED MAY 22 2013
.SYNOPSIS...
A STALLED FRONT WILL REMAIN IN THE VICINITY INTO THURSDAY. A COLD
FRONT WILL THEN SLOWLY APPROACH FROM THE WEST THURSDAY...THEN MOVE
INTO WESTERN PORTIONS OF THE TRI-STATE THURSDAY NIGHT. A WAVE OF
LOW PRESSURE DEVELOPS ALONG THIS SLOW MOVING COLD FRONT
FRIDAY...REMAINS JUST EAST OF THE REGION SATURDAY...AND THEN
TRACKS NORTH ALONG THE NEW ENGLAND COAST ON SUNDAY. HIGH PRESSURE
OVER THE GREAT LAKES BUILDS SOUTHEAST ACROSS THE AREA MONDAY INTO
TUESDAY. A WARM FRONT WILL THEN APPROACH FROM THE SOUTHWEST BY MID
WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
WEAK FRONTAL BOUNDARY REMAINS STALLED JUST TO THE W AND S OF THE
AREA...WITH A MARINE AIRMASS REMAINING IN PLACE. THIS FRONT SHOULD
NOT MOVE MUCH...IF AT ALL TONIGHT...SO WOULD EXPECT MOST IF NOT
ALL PRECIPITATION TO GO N OF THE AREA. THIS IS CONSISTENT WITH THE
HRRR AND RAP...WHICH HAVE HAD THE BEST HANDLE ON THIS FRONT AND
THE WEATHER TODAY BY FAR...ALONG WITH THE NAM AND SREF.
BASED ON THIS HAVE GONE BASICALLY DRY ACROSS THE S 2/3 OF THE CWA
THIS EVENING...WITH SLIGHT CHANCE POPS FAR N TIER...THEN SLIGHT
CHANCE POPS THROUGHOUT OVERNIGHT IN RESPONSE TO AN APPROACHING
700-500 HPA SHORTWAVE.
WITH MARINE LAYER INTACT - WOULD EXPECT LOW CLOUD DECK TO RE-
ESTABLISH ITSELF ACROSS THE AREA OVERNIGHT. COULD SEE PATCHY FOG
AS WELL - POSSIBLY LOCALLY DENSE NEAR THE ATLANTIC COAST.
FOR LOWS USED A BLEND OF 50 PERCENT MAV GUIDANCE WITH 25 PERCENT
MET GUIDANCE AND 25 PERCENT NAM 2-METER TEMPERATURES. FORECASTING
LOWS 10-15 DEGREES ABOVE NORMAL.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
MIXING ASSOCIATED WITH PASSING 700-500 HPA SHORTWAVE THURSDAY
MORNING SHOULD ERODE THE MARINE INVERSION - BUT STILL WILL BE
LEFT WITH QUITE A BIT OF MID TO HIGH CLOUDS WITH MOIST SW FLOW
ALOFT.
PRE-FRONTAL TROUGH MOVING INTO THE LOWER HUDSON VALLEY/NE NJ
THURSDAY AFTERNOON SHOULD SERVE AS TRIGGER FOR SCT-NUMEROUS SHRA
WITH EMBEDDED TSRA. LIKELY POPS MAINLY FROM NYC-INTERIOR SW CT
ZONES ON W AND CHANCE POPS EAST OF THAT LINE. SOME SUGGESTION FROM
NAM/GFS THAT EASTERN AREAS WILL REMAIN DRY THURSDAY...BUT FOR NOW
TOO MUCH LOW-MID LEVEL MOISTURE AND INCREASING LOW LEVEL JET TO
FORECAST THAT AT THIS TIME.
WITH 30-35 KT BULK SHEAR...1000-1500 J/KG OF CAPE AND BULK
RICHARDSON NUMBERS 15-30 HAVE THE POTENTIAL FOR ISOLATED SEVERE
STORMS THURSDAY AFTERNOON ACROSS NE NJ/LOWER HUDSON VALLEY AND
MAYBE NYC AND SW CT ZONES. MAIN THREAT IS GUSTY WINDS AND LARGE
HAIL. ALSO NEED TO WATCH FOR LOW LEVEL HELICITY WITH S SFC FLOW
AND SW FLOW AT 850 HPA.
FOR HIGHS THURSDAY USED A BLEND OF MIXING DOWN FROM 975 HPA NEAR
THE COAST AND 950 HPA INLAND...WITH NAM 2-METER TEMPERATURES AND A
BLEND OF MAV AND MET GUIDANCE. FORECASTING VALUES AROUND NORMAL
EAST TO A FEW DEGREES ABOVE NORMAL WEST.
DEEP SW FLOW ALOFT...BECOMES DIFFLUENT AT 500 HPA AFTER MIDNIGHT.
HAVE THE POTENTIAL FOR HEAVY RAINFALL AS A RESULT. REFER TO THE
HYDROLOGY SECTION FOR DETAILS. SEVERE THREAT COULD LINGER INTO THE
EVENING ACROSS WESTERN ZONES AS WELL.
FOR LOWS THURSDAY NIGHT USED A BLEND OF MAV/MET GUIDANCE WITH
VALUES FORECAST AROUND 10 DEGREES ABOVE NORMAL.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
MODELS HAVE TRENDED CONSIDERABLY SLOWER AND DEEPER WITH THE
APPROACHING UPPER TROUGH OVER THE MID SECTION OF THE COUNTRY. THERE
IS VERY GOOD AGREEMENT WITH THE 12Z GFS AND ECMWF ON TAKING A CLOSED
UPPER LOW FROM THE MID ATLANTIC STATES ON FRI NE TO OVER NEW ENGLAND
ON SUN. THE NAM AND GGEM ARE TRENDING IN THAT DIRECTION...BUT ARE
MORE PROGRESSIVE BEYOND 00Z SAT. PREFERENCE AT THIS TIME IS TO GO
WITH THE SLOWER GFS/ECMWF SOLUTION BASED ON MODEL TRENDS AND THE RUN
TO RUN CONTINUITY BEING EXHIBITED OVER THE LAST SEVERAL MODEL CYCLES.
AS FOR SENSIBLE WEATHER...THIS RESULTS IN A WET...COOL WEEKEND WITH
THE POTENTIAL FOR ANOTHER 1 TO 2 INCHES OF RAINFALL IN THE FRI-SAT
TIME FRAME. SINCE THIS IS A BIG ADJUSTMENT FROM THE PREVIOUS
FORECAST...HAVE RAMPED UP RAIN CHANCES FRI INTO SAT...BUT THESE MAY
BE UNDERDONE...ESPECIALLY FOR SAT WHERE THERE IS A TREND IN THE
FORECAST TO DRY THINGS OUT SAT INTO SUN. LATEST ECMWF KEEPS
CONDITIONS WET INTO SUN WITH A GUSTY NW FLOW ON THE BACKSIDE. SO
THIS IS THE POINT IN THE FORECAST WHERE CONDITIONS MAY CONTINUE TO
DETERIORATE WITH SUBSEQUENT MODEL RUNS.
ONCE AGAIN...WHILE THE FORECAST HAS AGGRESSIVELY TAKEN A DOWNWARD
NOTE FOR THE HOLIDAY WEEKEND...RAIN CHANCES MAY BE ON THE INCREASE
SAT INTO SUN BASED ON LATEST TRENDS IN THE MODEL GUIDANCE.
IN ADDITION...SOME OF THE RAINFALL ON FRI...OR AT LEAST THE FIRST
HALF OF THE DAY MAY BE CONVECTIVE WITH LOCALIZED HEAVY RAINFALL WITH
ANY EMBEDDED THUNDERSTORMS. THEREAFTER...THE AIRMASS STABILIZES IN
THE LOW-LEVELS WITH POST-FRONTAL RAIN/SHOWERS...PRIMARILY DRIVEN BY
FRONTOGENETIC FORCING ON THE BACKSIDE OF THE LOW. WIND GUSTS SAT
INTO SUN MAY BE UP TO 35 MPH...BUT THIS IS THE POTENTIAL...WITH THE
FORECASTS SIGNIFICANTLY LOWER AT THIS TIME.
AS FOR TEMPS...DAYTIME HIGHS WITH THE CLOUD COVER AND RAIN WILL BE 5
TO 10 DEGREES BELOW NORMAL. STAYED BELOW GUIDANCE. OVERNIGHT LOWS
WILL BE CLOSE TO SEASONABLE. A GRADUAL WARM-UP TO NEAR SEASONABLE
LEVELS IS THEN FORECAST MON-WED.
&&
.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
FRONTAL BOUNDARY CONTINUES TO LINGER OVER THE AREA THIS AFTERNOON.
AS A RESULT...IMPROVEMENT HAS BEEN QUITE SLOW. IFR/MVFR CIGS AND
VSBY GENERALLY THE STANDARD. SOME POTENTIAL FOR A LITTLE MORE
IMPROVEMENT PRIMARILY AT NW TERMINALS.
IFR CONDITIONS MAY BE A LITTLE SLOWER TO RETURN AT KEWR...KTEB...AND
KSWF OVERNIGHT. HOWEVER...STILL HIGH ENOUGH POTENTIAL THAT IFR
CONDITIONS WERE INCLUDED IN THESE TAFS IN ADDITION TO ALL OTHER
SITES OVERNIGHT. POTENTIAL EXISTS FOR COASTAL TERMINALS TO DROP TO
LIFR AS WELL.
LOW-END CHANCES FOR TS TO AFFECT ANY ONE TERMINAL SITE AFTER 18Z
THURSDAY. HOWEVER...DID INCLUDE PROB30 GROUPS AT 30-HOUR SITES TO
INDICATE THE GROWING POTENTIAL LATE IN THE DAY.
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: POSSIBILITY FOR VSBY TO DROP QUICKER/LOWER
THAN FORECAST LATE THIS AFTERNOON INTO THIS EVENING.
KLGA FCSTER COMMENTS: POTENTIAL FOR CIGS TO GO VFR BRIEFLY EARLY
THIS EVENING.
KEWR FCSTER COMMENTS: CIGS MAY RISE HIGHER THAN INDICATED IN TAF
OVER NEXT 2-3 HOURS.
KTEB FCSTER COMMENTS: CIGS MAY RISE HIGHER THAN INDICATED IN TAF
OVER NEXT 2-3 HOURS.
KHPN FCSTER COMMENTS: CIGS MAY RISE HIGHER THAN INDICATED IN TAF
OVER NEXT 2-3 HOURS. POTENTIAL FOR VSBY/CIGS LOWER THAN FORECAST
TONIGHT.
KISP FCSTER COMMENTS: POSSIBILITY FOR VSBY TO DROP QUICKER/LOWER
THAN FORECAST LATE THIS AFTERNOON INTO THIS EVENING.
.OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY...
.THURSDAY-FRIDAY...NUMEROUS SHRA AND TSTMS POSSIBLE....PRIMARILY
THUR NIGHT AND FRIDAY. IFR POSSIBLE IN FOG AND STRATUS.
.SATURDAY...SHRA LIKELY WITH MVFR OR LOWER. N WINDS 25-30G35KT.
.SUNDAY...MOST LIKELY VFR WITH NW WINDS 20-25KT. POTENTIAL FOR G
UP TO 40KT.
.MONDAY...VFR. NW WINDS 15-20G25KT.
&&
.MARINE...
LATEST SATELLITE IMAGERY...WEB-CAMS...AND RAP SOUNDINGS WARRANT
EXTENDING DENSE FOG ADVISORY FOR THE WATERS S/W OF LONG ISLAND
THROUGH TONIGHT. MIGHT ULTIMATELY END UP NEED TO EXTEND INTO
THURSDAY MORNING - BUT TO MUCH UNCERTAINTY WITH TIMING OF MIXING
AHEAD OF APPROACHING SHORTWAVE LATE TONIGHT TO DO SO AT THIS TIME.
SEAS ARE RUNNING 1-2 FT BELOW WAVEWATCH FORECAST - SO FOR NOW HAVE
TAKEN 1 FT OFF OF WAVEWATCH THROUGH THURSDAY NIGHT. STILL EXPECT
SEAS TO COME UP TO SCA LEVELS TONIGHT AND CONTINUE THROUGH
THURSDAY NIGHT. WINDS ALSO INCREASE LATE TONIGHT AND REMAIN UP
INTO THURSDAY NIGHT. INCREASING LOW LEVEL JET THROUGH THURSDAY
NIGHT INCREASES POTENTIAL FOR SCA LEVEL GUSTS OVER THE COASTAL
OCEAN WATERS - SO HAVE KEPT HEADLINE AS SCA VICE CONVERTING TO AN
SCA FOR HAZARDOUS SEAS.
MARINE INVERSION APPEARS WILL LIMIT MIXING - SO WHILE COULD SEE
OCCASIONAL GUSTS TO 25 KT OVER THE REMAINDER OF THE WATERS FROM
LATE TONIGHT INTO THURSDAY NIGHT - DO NOT HAVE CONFIDENCE TO ISSUE
SCA AT THIS TIME FOR THE NON-OCEAN ZONES.
THERE IS A GOOD POTENTIAL FOR SCA CONDITIONS TO CONTINUE THROUGH THE
UPCOMING WEEKEND AS LOW PRESSURE FORMS OVER THE WATERS ON FRI AND
LIFTS SLOWLY TO THE NORTH AND EAST. SCA CONDITIONS ARE BECOMING
INCREASINGLY LIKELY...WITH THE POTENTIAL FOR GALE CONDITIONS SAT
INTO SUN. WINDS AND SEAS BEGIN TO SUBSIDE LATE SUN INTO MON WITH
HIGH PRESSURE BUILDING IN FROM THE GREAT LAKES REGION.
&&
.HYDROLOGY...
THERE IS THE POTENTIAL FOR AROUND 3/4 TO 1 INCH BASIN AVERAGE QPF
THURSDAY AND THURSDAY NIGHT WITH LOCALLY HIGHER AMOUNTS.
DO NOT EXPECT ANY WIDESPREAD FLOOD THREAT THURSDAY FROM ANY
SHRA/TSRA BUT COULD SEE SOME MINOR FLOODING UNDER ANY STRONGER
CONVECTION - ESPECIALLY IF THERE IS ANY TRAINING.
THE HEAVIEST RAINFALL IN THIS TIME FRAME WILL BE LATE THURSDAY
NIGHT - WITH LOCALIZED RAINFALL RATES OF 1-1.5 INCHES/HR POSSIBLE
NOTING PRECIPITABLE WATERS OF 1.5-1/75 INCHES IN THIS TIME
FRAME. IF THESE RATES ARE REALIZED...ESPECIALLY IF THE STORMS
PRODUCING THEM PASS OVER AREAS RECEIVING LOCALLY HEAVY RAINFALL
THURSDAY...THERE IS THE POTENTIAL FOR LOCALIZED FLASH FLOODING.
THE THREAT FOR LOCALIZED HEAVY RAINFALL WILL CONTINUE INTO THE FIRST
HALF OF FRI WITH EMBEDDED CONVECTION. THEREAFTER...A STRATIFORM RAIN
AND/OR SHOWERS DEVELOPS ON THE BACKSIDE OF DEVELOPING LOW PRESSURE.
AN ADDITIONAL 1 TO 2 INCHES OF RAINFALL IS POSSIBLE FRI INTO SAT.
THIS MAY EXACERBATE ANY ONGOING FLOODING. RAIN MAY LINGER EVEN INTO
SUN BASED ON LATEST MODEL TRENDS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ338-345-350-
353-355.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT FRIDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...MALOIT/DW
NEAR TERM...MALOIT
SHORT TERM...MALOIT
LONG TERM...DW
AVIATION...PICCA/MET
MARINE...MALOIT/DW
HYDROLOGY...MALOIT/DW
AREA FORECAST DISCUSSION
NWS ALBANY NY
433 PM EDT WED MAY 22 2013
.SYNOPSIS...
A COLD FRONT WILL SLOWLY APPROACH THE REGION INTO FRIDAY. PERIODS
OF SHOWERS AND THUNDERSTORMS WILL PRECEDE THE FRONT. THE RAIN WILL
BE HEAVY AT TIMES. COOLER AND SHOWERY CONDITIONS WILL PERSIST
INTO THE FIRST HALF OF THE MEMORIAL DAY WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
...SEVERE THUNDERSTORM WATCH 210 IN EFFECT UNTIL 10 PM...
MAIN BAND OF CONVECTION AND ASSOCIATED SEVERE WEATHER AND FLOODING
RAINFALL CONTINUES TO PROGRESS EAST. SOME REPORTS OF WIND DAMAGE
IN SCHENECTADY AND SCHOHARIE COUNTIES. MEANWHILE...HEAVY
RAINFALL...RADAR ESTIMATE SHOWS 2-3 INCHES HAS LED TO URBAN
FLOODING IN SCHENECTADY COUNTY.
WITH MCS-LIKE SYSTEM CONTINUING TO TRACK NORTHEAST THROUGH THE
LATE AFTERNOON SEVERE THREAT/FLASH FLOOD THREAT WILL CONTINUE EAST.
ATTENTION WILL TURN TO ACTIVITY FOR LATER THIS AFTERNOON AND
TONIGHT. CURRENTLY TO OUR WEST LAKE BREEZES ARE FORCING ISOLD
TSRA. HRRR SHOWS LAKE BREEZE TO BLOSSOM WITH CONVECTION INTO LATER
THIS AFTERNOON AND EVENING AS LARGER SCALE ASCENT TRANSLATES
EASTWARD FROM LOWER LAKES. INSTABILITY HAS RECOVERED ACROSS
WESTERN CWA WITH MESOANALYSIS SHOWS CAPES IN 1500-2000 J/KG RANGE.
BULK SHEAR WILL REMAIN FAVORABLE FOR SEVERE STORMS WITH VALUES
INTO THE 30-40 KNOT RANGE. WILL CARRY ENHANCED WORDING TO COINCIDE
WITH WATCH...THEN SCT SHRA/TSRA THROUGH REMAINDER OF OVERNIGHT AS
WAIT TO SEE HOW CONVECTION EVOLVES.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
COLD FRONT SLOWLY APPROACHES THE REGION ON THURSDAY...NOT CLEARING
CWA UNTIL FRIDAY MORNING.
SLOWLY MOVING FRONT WILL PROVIDE ENVIRONMENT FOR BOUTS OF HEAVY
RAIN THROUGH THE PERIOD. PWATS REMAIN IN THE 1.5 INCH RANGE
THROUGH THURSDAY...ONLY SLOWLY DROPPING OFF INTO FRIDAY.
APPROACHING UPPER LEVEL JET TOMORROW BRINGS RIGHT REAR QUAD INTO
FORECAST AREA FOR THE AFTERNOON. SEE HYDRO SECTION FOR DISCUSSION
ON FLOOD RISK.
SEVERE POTENTIAL TOMORROW IS NOT CLEAR CUT NOW. MODEL CAPE LOOKS
TO BE IN THE 1000 J/KG RANGE WITH BULK SHEAR RESPECTABLE IN THE
30-40 KNOT RANGE. MID LEVEL LAPSE RATES ARE RELATIVELY WEAK AT
5.5C/KM. SPC HAS REGION IN SEE TEXT. FROM TODAY/S VANTAGE POINT
THAT LOOKS APPROPRIATE.
WITH COLD FRONT MOVING THROUGH ON FRIDAY...SOME DIMINISHING IN
PRECIP EXPECTED FOR PART OF FRIDAY. HOWEVER GFS AND ECMWF COMING
INTO AGREEMENT ON CUT OFF MIGRATING SLOWLY FROM DELMARVA INTO NEW
ENGLAND INTO THE HOLIDAY WEEKEND. THIS WILL KEEP THE THREAT OF
RAIN/SHOWERS IN THE FORECAST FOR FRIDAY. WITH CWA ON COOL SIDE OF
SURFACE LOW TRACK...INSTABILITY LOOKS NEAR NIL. SO NO MENTION OF
TSRA FOR FRIDAY.
MINS ON SATURDAY MORNING IN ADIRONDACKS ARE FORECAST IN MID 30S.
THIS WOULD MEAN THREAT OF FROST GIVEN BEGINNING OF THE GROWING
SEASON THERE. WILL DEPEND ON CLOUDS AND PRECIP.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
MODEL GUIDANCE HAS TRENDED TO A WET START TO THE HOLIDAY WEEKEND
ALONG WITH CHILLY TEMPERATURES DUE TO MORE CLOUD COVER.
THE MODEL GUIDANCE HAS COME INTO FAIRLY GOOD AGREEMENT THAT AN AREA
OF LOW PRESSURE WILL FORM ON THE COLD FRONT JUST OFF COAST NEAR CAPE
COD AS SHORT WAVES MOVE THROUGH THE LONGWAVE. AN UPPER LEVEL LOW IS
EXPECTED TO DEVELOP OVER THE MID ATLANTIC REGION FRIDAY NIGHT WITH
ADDITIONAL SHORT WAVES MAINTAINING THIS UPPER LOW WITH IT MOVING
GRADUALLY NORTHWARD UP THE COAST. THE LOW ALONG THE BOUNDARY WILL
SLOW THE FRONT`S EASTWARD PROGRESS AND THROW RAIN SHOWERS AND CLOUDS
BACK ACROSS NEW ENGLAND AND EASTERN NEW YORK STATE SATURDAY. THE
REGION WILL REMAIN UNDER CYCLONIC FLOW THROUGH THE WEEKEND WITH
UPPER RIDGING NOT EXPECTED TO BEGIN TO BUILD IN UNTIL TUESDAY. AT
THE SURFACE...HIGH PRESSURE SHOULD BEGIN TO BUILD IN MONDAY AND
ESPECIALLY TUESDAY. IT APPEARS THE HIGH SHOULD HOLD ON FOR WEDNESDAY.
AS FOR TEMPERATURES...CHILLY. TEMPERATURES ARE EXPECTED TO RUN 10 TO
15 DEGREES BELOW NORMAL SATURDAY AND AGAIN SUNDAY. BRISK AND GUSTY
NORTHWESTERLY WINDS WILL ONLY ADD TO THE CHILL. TEMPERATURES ARE
EXPECTED TO MODERATE TOWARD SEASONABLE LEVELS MONDAY WITH THE HELP
OF SUNSHINE BUT STILL BE BELOW NORMAL BY AROUND 5 DEGREES.
THE GROWING SEASON IS UNDERWAY ACROSS THE MID HUDSON VALLEY...
GREATER CAPITAL DISTRICT...LAKE GEORGE SARATOGA REGION...THE MOHAWK
VALLEY...EASTERN CATSKILLS...TACONICS...BERKSHIRES...BENNINGTON AND
EASTERN WINDHAM COUNTIES VT AND LITCHFIELD COUNTY. IT WILL START ON
MAY 25TH FOR THE SOUTHERN ADIRONDACKS AND WESTERN WINDHAM COUNTY.
NIGHTTIME LOWS OVER THE WEEKEND ARE EXPECTED TO BE IN THE 40S WITH
30S ACROSS THE HIGHER TERRAIN. WITH THE EXPANSION OF THE GROWING
SEASON BY THIS TIME FROST ADVISORIES MIGHT BE NEEDED. CONDITIONS
WILL BE MORE FAVORABLE FOR FROST SUNDAY NIGHT/MONDAY MORNING AND
MONDAY NIGHT/TUESDAY MORNING.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
VFR PREVAILING WITH PERIODS OF MVFR FOR THE BALANCE OF THE
AFTERNOON. SCATTERED -SHRA AND TSRA WILL DIRECTLY AFFECT OR BE IN
THE VICINITY OF THE AIRPORTS FROM THE START OF THE TAF PERIOD
THROUGH AT LEAST 22Z. CLOUDS WILL BE HARD TO CLEAR
OUT...PARTICULARLY THE HIGH-LEVEL CI/CS...WHICH SHOULD LIMIT
INSTABILITY AND THE PROLIFERATION OF TS. HIGH DEWPOINTS OVERNIGHT
WILL RESULT IN SOME HAZY FOG...MAINLY MVFR...WITH A PERIOD OF IFR
FOG POSS AT KPSF WHERE WINDS THRU THE COLUMN WILL BE LIGHTER.
WITH LITTLE CHANGE IN THE ENVIRONMENT EXPECTED INTO EARLY
THURSDAY...MVFR CONDITIONS ARE EXPECTED TO PREVAIL AT THE AIRPORTS
INTO THE EARLY AFTERNOON HOURS...WITH MORE TS ACTIVITY IS
LIKELY...THOUGH PERHAPS NOT UNTIL AFTER THE END OF THE TAF PERIOD.
EXPECTING A PERIOD OF MARGINAL SHEAR DURING THE EARLY NIGHT EXCEPT
AT KPSF...35 KNOTS SHOULD BE ABOUT IT. SURFACE WINDS WILL HOLD UP
OVERNIGHT AT LESS THAN 10 KNOTS...PICKING UP TO SPEEDS ON THURSDAY
AVERAGING SLIGHTLY HIGHER THAN TODAY.
OUTLOOK...
THU PM AND NGT...MVFR WITH IFR POSSIBLE. -SHRA/-TSRA LIKELY.
FRI-FRI NGT...MAINLY VFR. CHC -SHRA/-TSRA...MAINLY IN THE AM.
SAT-SUN...VFR. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS INTO SATURDAY. PERIODS OF RAIN...MODERATE
TO HEAVY AT TIMES WILL CONTINUE INTO THE HOLIDAY WEEKEND.
RH VALUES WILL INCREASE TO 85 TO 100 PERCENT TONIGHT...AND
THURSDAY NIGHT...AND LOWER TO 45 TO 60 PERCENT THURSDAY AFTERNOON.
WINDS WILL GENERALLY BE SOUTH AT 5 TO 10 MPH.
&&
.HYDROLOGY...
ECMWF AND GFS VERY AGGRESSIVE IN BRINGING HEAVY RAINFALL INTO CWA
INTO THE MEMORIAL DAY WEEKEND. OPERATIONAL ECMWF AND GFS PRODUCE
5-7.5 INCHES OF RAIN IN CWA INTO SUNDAY. GEFS SHOW AVERAGE OF 2.25
INCHES THROUGH WEEKEND WITH 4 MEMBERS PUSHING IN EXCESS OF 3
INCHES. WHILE NOT QUITE READY TO ACCEPT TOTALS OF EURO AND
GFS...ENOUGH GUIDANCE AVAILABLE TO AT LEAST WARRANT POTENTIAL OF
HEAVY RAIN THREAT IN HWO. FIRST CHALLENGE FOR HEAVY RAIN WILL COME
TOMORROW WITH SLOWLY MOVING FRONT. EASTERN CWA AND CENTRAL CWA
HAVE SEEN HEAVIEST RAIN OVER THE LAST TWO DAYS AND WOULD APPEAR TO
BE THE REGION WHERE FLASH FLOOD THREAT IS AT HIGHEST.
WILL MONITOR CLOSELY FOR AT LEAST POTENTIAL OF FLASH FLOOD OR
FLOOD WATCH THURSDAY INTO WEEKEND.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...OKEEFE
NEAR TERM...OKEEFE
SHORT TERM...OKEEFE
LONG TERM...IAA
AVIATION...ELH/WASULA
FIRE WEATHER...OKEEFE
HYDROLOGY...OKEEFE
AREA FORECAST DISCUSSION
NWS NEW YORK NY
407 PM EDT WED MAY 22 2013
.SYNOPSIS...
A STALLED FRONT WILL REMAIN IN THE VICINITY INTO THURSDAY. A COLD
FRONT WILL THEN SLOWLY APPROACH FROM THE WEST THURSDAY...THEN MOVE
INTO WESTERN PORTIONS OF THE TRI-STATE THURSDAY NIGHT. A WAVE OF
LOW PRESSURE DEVELOPS ALONG THIS SLOW MOVING COLD FRONT
FRIDAY...REMAINS JUST EAST OF THE REGION SATURDAY...AND THEN
TRACKS NORTH ALONG THE NEW ENGLAND COAST ON SUNDAY. HIGH PRESSURE
OVER THE GREAT LAKES BUILDS SOUTHEAST ACROSS THE AREA MONDAY INTO
TUESDAY. A WARM FRONT WILL THEN APPROACH FROM THE SOUTHWEST BY MID
WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
WEAK FRONTAL BOUNDARY REMAINS STALLED JUST TO THE W AND S OF THE
AREA...WITH A MARINE AIRMASS REMAINING IN PLACE. THIS FRONT SHOULD
NOT MOVE MUCH...IF AT ALL TONIGHT...SO WOULD EXPECT MOST IF NOT
ALL PRECIPITATION TO GO N OF THE AREA. THIS IS CONSISTENT WITH THE
HRRR AND RAP...WHICH HAVE HAD THE BEST HANDLE ON THIS FRONT AND
THE WEATHER TODAY BY FAR...ALONG WITH THE NAM AND SREF.
BASED ON THIS HAVE GONE BASICALLY DRY ACROSS THE S 2/3 OF THE CWA
THIS EVENING...WITH SLIGHT CHANCE POPS FAR N TIER...THEN SLIGHT
CHANCE POPS THROUGHOUT OVERNIGHT IN RESPONSE TO AN APPROACHING
700-500 HPA SHORTWAVE.
WITH MARINE LAYER INTACT - WOULD EXPECT LOW CLOUD DECK TO RE-
ESTABLISH ITSELF ACROSS THE AREA OVERNIGHT. COULD SEE PATCHY FOG
AS WELL - POSSIBLY LOCALLY DENSE NEAR THE ATLANTIC COAST.
FOR LOWS USED A BLEND OF 50 PERCENT MAV GUIDANCE WITH 25 PERCENT
MET GUIDANCE AND 25 PERCENT NAM 2-METER TEMPERATURES. FORECASTING
LOWS 10-15 DEGREES ABOVE NORMAL.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
MIXING ASSOCIATED WITH PASSING 700-500 HPA SHORTWAVE THURSDAY
MORNING SHOULD ERODE THE MARINE INVERSION - BUT STILL WILL BE
LEFT WITH QUITE A BIT OF MID TO HIGH CLOUDS WITH MOIST SW FLOW
ALOFT.
PRE-FRONTAL TROUGH MOVING INTO THE LOWER HUDSON VALLEY/NE NJ
THURSDAY AFTERNOON SHOULD SERVE AS TRIGGER FOR SCT-NUMEROUS SHRA
WITH EMBEDDED TSRA. LIKELY POPS MAINLY FROM NYC-INTERIOR SW CT
ZONES ON W AND CHANCE POPS EAST OF THAT LINE. SOME SUGGESTION FROM
NAM/GFS THAT EASTERN AREAS WILL REMAIN DRY THURSDAY...BUT FOR NOW
TOO MUCH LOW-MID LEVEL MOISTURE AND INCREASING LOW LEVEL JET TO
FORECAST THAT AT THIS TIME.
WITH 30-35 KT BULK SHEAR...1000-1500 J/KG OF CAPE AND BULK
RICHARDSON NUMBERS 15-30 HAVE THE POTENTIAL FOR ISOLATED SEVERE
STORMS THURSDAY AFTERNOON ACROSS NE NJ/LOWER HUDSON VALLEY AND
MAYBE NYC AND SW CT ZONES. MAIN THREAT IS GUSTY WINDS AND LARGE
HAIL. ALSO NEED TO WATCH FOR LOW LEVEL HELICITY WITH S SFC FLOW
AND SW FLOW AT 850 HPA.
FOR HIGHS THURSDAY USED A BLEND OF MIXING DOWN FROM 975 HPA NEAR
THE COAST AND 950 HPA INLAND...WITH NAM 2-METER TEMPERATURES AND A
BLEND OF MAV AND MET GUIDANCE. FORECASTING VALUES AROUND NORMAL
EAST TO A FEW DEGREES ABOVE NORMAL WEST.
DEEP SW FLOW ALOFT...BECOMES DIFFLUENT AT 500 HPA AFTER MIDNIGHT.
HAVE THE POTENTIAL FOR HEAVY RAINFALL AS A RESULT. REFER TO THE
HYDROLOGY SECTION FOR DETAILS. SEVERE THREAT COULD LINGER INTO THE
EVENING ACROSS WESTERN ZONES AS WELL.
FOR LOWS THURSDAY NIGHT USED A BLEND OF MAV/MET GUIDANCE WITH
VALUES FORECAST AROUND 10 DEGREES ABOVE NORMAL.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
MODELS HAVE TRENDED CONSIDERABLY SLOWER AND DEEPER WITH THE
APPROACHING UPPER TROUGH OVER THE MID SECTION OF THE COUNTRY. THERE
IS VERY GOOD AGREEMENT WITH THE 12Z GFS AND ECMWF ON TAKING A CLOSED
UPPER LOW FROM THE MID ATLANTIC STATES ON FRI NE TO OVER NEW ENGLAND
ON SUN. THE NAM AND GGEM ARE TRENDING IN THAT DIRECTION...BUT ARE
MORE PROGRESSIVE BEYOND 00Z SAT. PREFERENCE AT THIS TIME IS TO GO
WITH THE SLOWER GFS/ECMWF SOLUTION BASED ON MODEL TRENDS AND THE RUN
TO RUN CONTINUITY BEING EXHIBITED OVER THE LAST SEVERAL MODEL CYCLES.
AS FOR SENSIBLE WEATHER...THIS RESULTS IN A WET...COOL WEEKEND WITH
THE POTENTIAL FOR ANOTHER 1 TO 2 INCHES OF RAINFALL IN THE FRI-SAT
TIME FRAME. SINCE THIS IS A BIG ADJUSTMENT FROM THE PREVIOUS
FORECAST...HAVE RAMPED UP RAIN CHANCES FRI INTO SAT...BUT THESE MAY
BE UNDERDONE...ESPECIALLY FOR SAT WHERE THERE IS A TREND IN THE
FORECAST TO DRY THINGS OUT SAT INTO SUN. LATEST ECMWF KEEPS
CONDITIONS WET INTO SUN WITH A GUSTY NW FLOW ON THE BACKSIDE. SO
THIS IS THE POINT IN THE FORECAST WHERE CONDITIONS MAY CONTINUE TO
DETERIORATE WITH SUBSEQUENT MODEL RUNS.
ONCE AGAIN...WHILE THE FORECAST HAS AGGRESSIVELY TAKEN A DOWNWARD
NOTE FOR THE HOLIDAY WEEKEND...RAIN CHANCES MAY BE ON THE INCREASE
SAT INTO SUN BASED ON LATEST TRENDS IN THE MODEL GUIDANCE.
IN ADDITION...SOME OF THE RAINFALL ON FRI...OR AT LEAST THE FIRST
HALF OF THE DAY MAY BE CONVECTIVE WITH LOCALIZED HEAVY RAINFALL WITH
ANY EMBEDDED THUNDERSTORMS. THEREAFTER...THE AIRMASS STABILIZES IN
THE LOW-LEVELS WITH POST-FRONTAL RAIN/SHOWERS...PRIMARILY DRIVEN BY
FRONTOGENETIC FORCING ON THE BACKSIDE OF THE LOW. WIND GUSTS SAT
INTO SUN MAY BE UP TO 35 MPH...BUT THIS IS THE POTENTIAL...WITH THE
FORECASTS SIGNIFICANTLY LOWER AT THIS TIME.
AS FOR TEMPS...DAYTIME HIGHS WITH THE CLOUD COVER AND RAIN WILL BE 5
TO 10 DEGREES BELOW NORMAL. STAYED BELOW GUIDANCE. OVERNIGHT LOWS
WILL BE CLOSE TO SEASONABLE. A GRADUAL WARM-UP TO NEAR SEASONABLE
LEVELS IS THEN FORECAST MON-WED.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
FRONTAL BOUNDARY CONTINUES TO LINGER OVER THE AREA THIS AFTERNOON.
AS A RESULT...IMPROVEMENT HAS BEEN QUITE SLOW. IFR/MVFR CIGS AND
VSBY GENERALLY THE STANDARD. SOME POTENTIAL FOR A LITTLE MORE
IMPROVEMENT PRIMARILY AT NW TERMINALS.
RECENT OBS SHOW WINDS FINALLY TURNING S AT KJFK/KEWR...WHICH MAY
BE A SIGN OF BRIEFLY INCREASING VSBY/CIGS. HOWEVER...BASED ON
CURRENT OBS AND DEVELOPING S WIND...GROWING POTENTIAL FOR IFR
VSBY TO PUSH BACK INTO COASTAL TERMINALS OVER NEXT FEW HOURS.
POTENTIAL FOR CONDITIONS TO DROP SOLIDLY INTO IFR AGAIN
TONIGHT...HOWEVER MUCH UNCERTAINTY EXISTS OVER TIMING AND EXTENT.
POTENTIAL ALSO EXISTS FOR LIFR/VLIFR ACROSS COASTAL TERMINALS.
DID NOT SHOW TS IN TAFS ON THURSDAY JUST YET...AS UPPER-LEVEL FLOW
INDICATES STORMS MAY BE SLOW TO APPROACH WESTERN TERMINALS AND
COULD HOLD OFF UNTIL LATE IN THE DAY. HOWEVER...LOW END
POTENTIAL EXISTS AT W TERMS GENERALLY 23/18Z THROUGH 24/00Z.
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: POSSIBILITY FOR VSBY TO DROP QUICKER/LOWER
THAN FORECAST LATE THIS AFTERNOON INTO THIS EVENING.
KLGA FCSTER COMMENTS: POTENTIAL FOR CIGS TO GO VFR BRIEFLY THIS
AFTERNOON AND EARLY THIS EVENING. WIND DIRECTION MAY STAY E/NE A
COUPLE HOURS LONGER THAN INDICATED IN TAF.
KEWR FCSTER COMMENTS: CIGS MAY RISE HIGHER THAN INDICATED IN TAF
OVER NEXT 2-3 HOURS. POTENTIAL FOR VSBY/CIGS LOWER THAN FORECAST
TONIGHT.
KTEB FCSTER COMMENTS: CIGS MAY RISE HIGHER THAN INDICATED IN TAF
OVER NEXT 2-3 HOURS. POTENTIAL FOR VSBY/CIGS LOWER THAN FORECAST
TONIGHT.
KHPN FCSTER COMMENTS: CIGS MAY RISE HIGHER THAN INDICATED IN TAF
OVER NEXT 2-3 HOURS. POTENTIAL FOR VSBY/CIGS LOWER THAN FORECAST
TONIGHT.
KISP FCSTER COMMENTS: POSSIBILITY FOR VSBY TO DROP QUICKER/LOWER
THAN FORECAST LATE THIS AFTERNOON INTO THIS EVENING.
.OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY...
.THURSDAY-FRIDAY...NUMEROUS SHRA AND TSTMS POSSIBLE....PRIMARILY
THUR NIGHT AND FRIDAY. IFR POSSIBLE IN FOG AND STRATUS.
.SATURDAY...SHRA LIKELY WITH MVFR OR LOWER. N WINDS 25-30G35KT.
.SUNDAY...MOST LIKELY VFR WITH NW WINDS 20-25KT. POTENTIAL FOR G
UP TO 40KT.
.MONDAY...VFR. NW WINDS 15-20G25KT.
&&
.MARINE...
LATEST SATELLITE IMAGERY...WEB-CAMS...AND RAP SOUNDINGS WARRANT
EXTENDING DENSE FOG ADVISORY FOR THE WATERS S/W OF LONG ISLAND
THROUGH TONIGHT. MIGHT ULTIMATELY END UP NEED TO EXTEND INTO
THURSDAY MORNING - BUT TO MUCH UNCERTAINTY WITH TIMING OF MIXING
AHEAD OF APPROACHING SHORTWAVE LATE TONIGHT TO DO SO AT THIS TIME.
SEAS ARE RUNNING 1-2 FT BELOW WAVEWATCH FORECAST - SO FOR NOW HAVE
TAKEN 1 FT OFF OF WAVEWATCH THROUGH THURSDAY NIGHT. STILL EXPECT
SEAS TO COME UP TO SCA LEVELS TONIGHT AND CONTINUE THROUGH
THURSDAY NIGHT. WINDS ALSO INCREASE LATE TONIGHT AND REMAIN UP
INTO THURSDAY NIGHT. INCREASING LOW LEVEL JET THROUGH THURSDAY
NIGHT INCREASES POTENTIAL FOR SCA LEVEL GUSTS OVER THE COASTAL
OCEAN WATERS - SO HAVE KEPT HEADLINE AS SCA VICE CONVERTING TO AN
SCA FOR HAZARDOUS SEAS.
MARINE INVERSION APPEARS WILL LIMIT MIXING - SO WHILE COULD SEE
OCCASIONAL GUSTS TO 25 KT OVER THE REMAINDER OF THE WATERS FROM
LATE TONIGHT INTO THURSDAY NIGHT - DO NOT HAVE CONFIDENCE TO ISSUE
SCA AT THIS TIME FOR THE NON-OCEAN ZONES.
THERE IS A GOOD POTENTIAL FOR SCA CONDITIONS TO CONTINUE THROUGH THE
UPCOMING WEEKEND AS LOW PRESSURE FORMS OVER THE WATERS ON FRI AND
LIFTS SLOWLY TO THE NORTH AND EAST. SCA CONDITIONS ARE BECOMING
INCREASINGLY LIKELY...WITH THE POTENTIAL FOR GALE CONDITIONS SAT
INTO SUN. WINDS AND SEAS BEGIN TO SUBSIDE LATE SUN INTO MON WITH
HIGH PRESSURE BUILDING IN FROM THE GREAT LAKES REGION.
&&
.HYDROLOGY...
THERE IS THE POTENTIAL FOR AROUND 3/4 TO 1 INCH BASIN AVERAGE QPF
THURSDAY AND THURSDAY NIGHT WITH LOCALLY HIGHER AMOUNTS.
DO NOT EXPECT ANY WIDESPREAD FLOOD THREAT THURSDAY FROM ANY
SHRA/TSRA BUT COULD SEE SOME MINOR FLOODING UNDER ANY STRONGER
CONVECTION - ESPECIALLY IF THERE IS ANY TRAINING.
THE HEAVIEST RAINFALL IN THIS TIME FRAME WILL BE LATE THURSDAY
NIGHT - WITH LOCALIZED RAINFALL RATES OF 1-1.5 INCHES/HR POSSIBLE
NOTING PRECIPITABLE WATERS OF 1.5-1/75 INCHES IN THIS TIME
FRAME. IF THESE RATES ARE REALIZED...ESPECIALLY IF THE STORMS
PRODUCING THEM PASS OVER AREAS RECEIVING LOCALLY HEAVY RAINFALL
THURSDAY...THERE IS THE POTENTIAL FOR LOCALIZED FLASH FLOODING.
THE THREAT FOR LOCALIZED HEAVY RAINFALL WILL CONTINUE INTO THE FIRST
HALF OF FRI WITH EMBEDDED CONVECTION. THEREAFTER...A STRATIFORM RAIN
AND/OR SHOWERS DEVELOPS ON THE BACKSIDE OF DEVELOPING LOW PRESSURE.
AN ADDITIONAL 1 TO 2 INCHES OF RAINFALL IS POSSIBLE FRI INTO SAT.
THIS MAY EXACERBATE ANY ONGOING FLOODING. RAIN MAY LINGER EVEN INTO
SUN BASED ON LATEST MODEL TRENDS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ338-345-350-
353-355.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT FRIDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...MALOIT/DW
NEAR TERM...MALOIT
SHORT TERM...MALOIT
LONG TERM...DW
AVIATION...PICCA
MARINE...MALOIT/DW
HYDROLOGY...MALOIT/DW
AREA FORECAST DISCUSSION
NWS NEW YORK NY
215 PM EDT WED MAY 22 2013
.SYNOPSIS...
A STALLED FRONT WILL REMAIN IN THE VICINITY INTO THURSDAY. A COLD
FRONT WILL THEN SLOWLY APPROACH FROM THE WEST THURSDAY...THEN PASS
THROUGH THURSDAY NIGHT INTO FRIDAY MORNING. CANADIAN HIGH PRESSURE
WILL THEN BUILD IN FOR THE MEMORIAL DAY WEEKEND AND EARLY NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BACK DOOR COLD FRONT THAT WENT THROUGH OVERNIGHT REMAINS STALLED
OUT TO THE W AND S OF THE AREA. HRRR AND RAP ARE THE ONLY MODELS WITH
ANY CLUE TO ITS EXISTENCE. LOOKING AT TRENDS IN VISIBLE SATELLITE
AND RAP SOUNDINGS...HAVE DOUBTS ABOUT HRRR/RAP SHOWING BOUNDARY
PUSH BACK INTO FAR W ZONES AS A WARM FRONT LATE THIS AFTERNOON.
AS A RESULT HAVE KEPT FORECAST CLOUDY-MOSTLY CLOUDY AND LOWERED
TEMPERATURES AGAIN. NOW FORECASTING HIGHS MAINLY IN THE 70S...WITH
UPPER 60S AT THE IMMEDIATE COAST.
STILL APPEARS MOST OF THE AREA WILL BE DRY THIS AFTERNOON PER
HRRR/RAP. HOWEVER WITH CONVECTION FIRING W OF AREA...HAVE KEPT
SLIGHT CHANCE TO CHANCE POPS THIS AFTERNOON OVER THE NW 1/2 OF THE
CWA WITH A SLIGHT CHANCE OF THUNDER. ANY THUNDERSTORMS WILL MOST
LIKELY BE ELEVATED IN NATURE AS THEY MOVE OVER THE AREA DUE TO THE
MARINE INVERSION IN PLACE...SO THE SEVERE THREAT THIS AFTERNOON IS
NIL ACROSS THE SE 1/2 OF THE CWA AND LESS THAN 5 PERCENT ELSEWHERE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
INCREASING CONCERN THAT THE MARINE LAYER WILL NOT DISSIPATE/FRONT
LIFT TO THE N BY THIS EVENING - AND THAT THE MARINE LAYER WILL
MAINTAIN ITSELF OVER MOST IF NOT ALL THE AREA TONIGHT. WILL
CONTINUE TO MONITOR TRENDS - BUT COULD END UP MAKING SIGNIFICANT
CHANGES TO TONIGHTS FORECAST IF CURRENT TRENDS HOLD.
SCT-ISOLD SHOWERS AND TSTMS THIS EVENING. CONVECTION SHOULD BE
SCATTERED AT BEST WITH ONLY MARGINAL INSTABILITY IN PLACE. SHOWERS
AND THUNDERSTORMS WILL BECOME MORE WIDESPREAD THURSDAY AS THE
UPPER LEVEL TROUGH AND ASSOCIATED SURFACE COLD FRONT APPROACH THE
AREA.
HIGHS ON THURSDAY IN THE MID TO UPPER 70S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
MAIN ISSUE FOR THE START OF THIS PERIOD IS THE INTERACTION OF THE
EASTWARD MOVING CENTRAL US TROUGH WITH SEVERAL NORTHERN STREAM
SHORTWAVES ROTATING AROUND A PERSISTENT EASTERN CANADIAN TROUGH. THE
COMPLEX INTERACTION IS RESULTING IN TIMING AND AMPLIFICATION ISSUES
AS THIS TROUGH SLIDES TO THE EAST COAST. GFS CONTINUES TO BE SLOWER
THAN ALL THE GUIDANCE FRI INTO SAT AS THE UPPER LOW NEGATIVELY TILTS
AND CLOSES OFF AS IT APPROACHES THE MID ATLANTIC STATES. THIS WOULD
RESULT IN A PROLONGED PERIOD OF POST-FRONTAL RAIN INTO SAT. WITH
MAJORITY OF 00Z OPERATIONAL GUIDANCE TRENDING A BIT SLOWER...HAVE
ALSO TRENDED A BIT SLOWER WITH PRECIPITATION GRADUALLY TAPERING
OFF FRI AFTERNOON INTO FRI NIGHT. SUBSEQUENT MODEL TRENDS WILL
NEED TO BE CLOSELY MONITORED TO SEE IF THE FRONTAL SYSTEM SLOWS
DOWN EVEN FURTHER.
AS FOR THE SENSIBLE WEATHER...COLD FRONT SLOWLY CROSSES THE REGION
THU NIGHT INTO FRI. ALTHOUGH INSTABILITY WILL LIKELY BE FALLING TO
MARGINAL LEVELS THURSDAY NIGHT...WIDESPREAD SHOWER AND THUNDERSTORM
DEVELOPMENT IS LIKELY WITH ABUNDANT MOISTURE STREAMING AHEAD OF
APPROACHING SHORTWAVE ENERGY/COLD FRONT. THE SEVERE THREAT SHOULD
DIMINISH INTO THURSDAY NIGHT...WITH HEAVY RAIN THE MAIN THREAT
WITH PWATS ABOUT 2 STD ABOVE NORMAL AND STEERING FLOW NEARLY ALIGNED
WITH THE SLOW MOVING FRONT. WILL HAVE TO MONITOR THE EXTENT OF
INTERACTION OF THE FRONT WITH A SUBTROPICAL PLUME STREAMING UP THE
COAST THURSDAY NIGHT...WHICH IF CLOSER TO THE COAST WOULD ENHANCE
THE FLASH FLOOD THREAT. CONVECTIVE THREAT SHOULD DECREASE IN
THE WAKE OF THE COLD FRONT...BUT POTENTIAL WAVE DEVELOPMENT COULD
PROLONG LIGHT TO MODERATE POST-FRONTAL STRATIFORM RAINS THROUGH
FRIDAY INTO FRI NIGHT...PARTICULARLY ACROSS EASTERN SECTIONS.
AVERAGE BASIN RAINFALL SHOULD BE CLOSE TO AN INCH...WITH LOCALIZED
HIGHER AMOUNTS.
A DRYING NW FLOW SET UPS FRI NIGHT INTO SAT WITH STRONG COLD
ADVECTION. HIGH PRESSURE BUILDS ACROSS THE GREAT LAKES AND INTO
THE MID ATLANTIC STATES THROUGH EARLY NEXT WEEK WITH TEMPERATURES
SEVERAL DEGREES BELOW SEASONABLE LEVELS.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
FRONTAL BOUNDARY CONTINUES TO LINGER OVER THE AREA THIS AFTERNOON.
AS A RESULT...IMPROVEMENT HAS BEEN QUITE SLOW. IFR/MVFR CIGS AND
VSBY GENERALLY THE STANDARD. SOME POTENTIAL FOR A LITTLE MORE
IMPROVEMENT PRIMARILY AT NW TERMINALS.
RECENT OBS SHOW WINDS FINALLY TURNING S AT KJFK/KEWR...WHICH MAY
BE A SIGN OF BRIEFLY INCREASING VSBY/CIGS. HOWEVER...BASED ON
CURRENT OBS AND DEVELOPING S WIND...GROWING POTENTIAL FOR IFR
VSBY TO PUSH BACK INTO COASTAL TERMINALS OVER NEXT FEW HOURS.
POTENTIAL FOR CONDITIONS TO DROP SOLIDLY INTO IFR AGAIN
TONIGHT...HOWEVER MUCH UNCERTAINTY EXISTS OVER TIMING AND EXTENT.
POTENTIAL ALSO EXISTS FOR LIFR/VLIFR ACROSS COASTAL TERMINALS.
DID NOT SHOW TS IN TAFS ON THURSDAY JUST YET...AS UPPER-LEVEL FLOW
INDICATES STORMS MAY BE SLOW TO APPROACH WESTERN TERMINALS AND
COULD HOLD OFF UNTIL LATE IN THE DAY. HOWEVER...LOW END
POTENTIAL EXISTS AT W TERMS GENERALLY 23/18Z THRU 24/00Z.
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: POSSIBILITY FOR VSBY TO DROP QUICKER/LOWER
THAN FORECAST LATE THIS AFTERNOON INTO THIS EVENING.
KLGA FCSTER COMMENTS: POTENTIAL FOR CIGS TO GO VFR BRIEFLY THIS
AFTERNOON AND EARLY THIS EVENING. WIND DIRECTION MAY STAY E/NE A
COUPLE HOURS LONGER THAN INDICATED IN TAF.
KEWR FCSTER COMMENTS: CIGS MAY RISE HIGHER THAN INDICATED IN TAF
OVER NEXT 2-3 HOURS. POTENTIAL FOR VSBY/CIGS LOWER THAN FORECAST
TONIGHT.
KTEB FCSTER COMMENTS: CIGS MAY RISE HIGHER THAN INDICATED IN TAF
OVER NEXT 2-3 HOURS. POTENTIAL FOR VSBY/CIGS LOWER THAN FORECAST
TONIGHT.
KHPN FCSTER COMMENTS: CIGS MAY RISE HIGHER THAN INDICATED IN TAF
OVER NEXT 2-3 HOURS. POTENTIAL FOR VSBY/CIGS LOWER THAN FORECAST
TONIGHT.
KISP FCSTER COMMENTS: POSSIBILITY FOR VSBY TO DROP QUICKER/LOWER
THAN FORECAST LATE THIS AFTERNOON INTO THIS EVENING.
.OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY...
.THURSDAY-FRIDAY...NUMEROUS SHRA AND TSTMS POSSIBLE....PRIMARILY
THUR NIGHT AND FRIDAY. IFR POSSIBLE IN FOG AND STRATUS.
.SATURDAY...SHRA LIKELY WITH MVFR OR LOWER. N WINDS 25-30G35KT.
.SUNDAY...MOST LIKELY VFR WITH NW WINDS 20-25KT. POTENTIAL FOR G
UP TO 40KT.
.MONDAY...VFR. NW WINDS 15-20G25KT.
&&
.MARINE...
BASED ON HRRR AND LATEST TRENDS IN OBSERVATIONS AND WEB-CAMS HAVE
EXTENDED THE DENSE FOG ADVISORY FOR THE COASTAL OCEAN ZONES...NY
HARBOR AND THE SOUTH SHORE BAYS OF LONG ISLAND THROUGH 22Z. GIVEN
NO RESTRICTIONS OF 1NM OR LESS IN VISIBILITY EVIDENT ON SOUND OR
EASTERN BAYS OF LONG ISLAND...HAVE CANCELLED THE DENSE FOG
ADVISORY THERE.
THERE SEEMS TO BE INCREASING POTENIAL FOR DENSE FOG OVER THE
SOUTHERN WATERS TO CONTINUE TONIGHT. IF TRENDS HOLD...WILL EXTEND
THE DENSE FOG ADVISORY IN TIME THROUGH TONIGHT WITH THE LATE
AFTERNOON FORECAST ISSUANCE.
SEAS ARE NOT INCREASING AS FAST AS FORECAST...SO HAVE ADJUSTED
DOWNWARD A FOOT OR SO ACROSS MOST OCEAN AREAS INTO THIS EVENING.
SEAS SLOWLY BUILD THIS AFTERNOON/EVENING TO SCA LEVELS ON THE
COASTAL OCEAN WATERS AND REMAIN ABOVE SCA LEVELS THROUGH
THURSDAY. SW FLOW INCREASES OVER THE COASTAL OCEAN WATERS TONIGHT
AS WELL WITH SFC BOUNDARY LIFTING TO NEAR THE LONG ISLAND COAST IF
NOT FARTHER N.
A COLD FRONT WILL MOVE EAST ACROSS THE AREA WATERS LATE THURSDAY
THROUGH FRIDAY AFTERNOON...WITH HIGH PRESSURE BUILDING THROUGH THE
WEEKEND. WINDS SHOULD GRADUALLY FALL BELOW MARGINAL SCA LEVELS
THURSDAY NIGHT...WITH SCA SEAS ON THE OCEAN LIKELY REMAINING ABOVE
SCA CRITERIA THROUGH SATURDAY MORNING WITH RESIDUAL SOUTHERLY
SWELLS. UNDERCUT WAVEWATCH BY A FOOT DURING THIS TIME AS IT WAS
SLOWER BRINGING THE FRONTAL SYSTEM ACROSS THE AREA. THERE IS THOUGH
SOME UNCERTAINTY WITH THE SEAS DUE TO THE TIMING DIFFERENCES AMONGST
THE MODELS.
&&
.HYDROLOGY...
SCT SHOWERS/TSTMS THIS EVENING WILL BE CAPABLE OF PRODUCING
LOCALLY HEAVY RAINFALL...WITH THE BEST CHANCES NORTH/WEST OF NYC.
TOTAL BASIN AVG QPF FOR WED-THU COULD BE 1/4 TO 1/2 INCH...WITH
LOCALLY HIGHER AMOUNTS IN TSTMS.
SHOWERS AND THUNDERSTORMS AHEAD OF AN APPROACHING COLD FRONT LATE
THU INTO FRIDAY MORNING...SHOULD PRODUCE AVERAGE BASIN
RAINFALL AMOUNTS CLOSE TO AN INCH...WITH LOCALIZED HIGHER AMOUNTS.
THERE IS THE POTENTIAL FOR TRAINING OF THUNDERSTORMS WHICH COULD
RESULT IN FLASH FLOODING. ADDITIONAL LIGHTER RAINFALL AMOUNTS ARE
LIKELY FRIDAY...POSSIBLY INTO FRIDAY NIGHT.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ338-345-
350-353-355.
SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 6 PM EDT
THURSDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...24/NV
NEAR TERM...MALOIT/NV
SHORT TERM...24
LONG TERM...NV
AVIATION...PICCA
MARINE...24/MALOIT/NV
HYDROLOGY...24/NV
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1249 PM EDT WED MAY 22 2013
.SYNOPSIS...
A STALLED FRONT WILL REMAIN IN THE VICINITY INTO THURSDAY. A COLD
FRONT WILL THEN SLOWLY APPROACH FROM THE WEST THURSDAY...THEN PASS
THROUGH THURSDAY NIGHT INTO FRIDAY MORNING. CANADIAN HIGH PRESSURE
WILL THEN BUILD IN FOR THE MEMORIAL DAY WEEKEND AND EARLY NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BACK DOOR COLD FRONT THAT WENT THROUGH OVERNIGHT REMAINS STALLED
OUT TO THE W AND S OF THE AREA. HRRR AND RAP ARE THE ONLY MODELS WITH
ANY CLUE TO ITS EXISTENCE. LOOKING AT TRENDS IN VISIBLE SATELLITE
AND RAP SOUNDINGS...HAVE DOUBTS ABOUT HRRR/RAP SHOWING BOUNDARY
PUSH BACK INTO FAR W ZONES AS A WARM FRONT LATE THIS AFTERNOON.
AS A RESULT HAVE KEPT FORECAST CLOUDY-MOSTLY CLOUDY AND LOWERED
TEMPERATURES AGAIN. NOW FORECASTING HIGHS MAINLY IN THE 70S...WITH
UPPER 60S AT THE IMMEDIATE COAST.
STILL APPEARS MOST OF THE AREA WILL BE DRY THIS AFTERNOON PER
HRRR/RAP. HOWEVER WITH CONVECTION FIRING W OF AREA...HAVE KEPT
SLIGHT CHANCE TO CHANCE POPS THIS AFTERNOON OVER THE NW 1/2 OF THE
CWA WITH A SLIGHT CHANCE OF THUNDER. ANY THUNDERSTORMS WILL MOST
LIKELY BE ELEVATED IN NATURE AS THEY MOVE OVER THE AREA DUE TO THE
MARINE INVERSION IN PLACE...SO THE SEVERE THREAT THIS AFTERNOON IS
NIL ACROSS THE SE 1/2 OF THE CWA AND LESS THAN 5 PERCENT ELSEWHERE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
INCREASING CONCERN THAT THE MARINE LAYER WILL NOT DISSIPATE/FRONT
LIFT TO THE N BY THIS EVENING - AND THAT THE MARINE LAYER WILL
MAINTAIN ITSELF OVER MOST IF NOT ALL THE AREA TONIGHT. WILL
CONTINUE TO MONITOR TRENDS - BUT COULD END UP MAKING SIGNIFICANT
CHANGES TO TONIGHTS FORECAST IF CURRENT TRENDS HOLD.
SCT-ISOLD SHOWERS AND TSTMS THIS EVENING. CONVECTION SHOULD BE
SCATTERED AT BEST WITH ONLY MARGINAL INSTABILITY IN PLACE. SHOWERS
AND THUNDERSTORMS WILL BECOME MORE WIDESPREAD THURSDAY AS THE
UPPER LEVEL TROUGH AND ASSOCIATED SURFACE COLD FRONT APPROACH THE
AREA.
HIGHS ON THURSDAY IN THE MID TO UPPER 70S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
MAIN ISSUE FOR THE START OF THIS PERIOD IS THE INTERACTION OF THE
EASTWARD MOVING CENTRAL US TROUGH WITH SEVERAL NORTHERN STREAM
SHORTWAVES ROTATING AROUND A PERSISTENT EASTERN CANADIAN TROUGH. THE
COMPLEX INTERACTION IS RESULTING IN TIMING AND AMPLIFICATION ISSUES
AS THIS TROUGH SLIDES TO THE EAST COAST. GFS CONTINUES TO BE SLOWER
THAN ALL THE GUIDANCE FRI INTO SAT AS THE UPPER LOW NEGATIVELY TILTS
AND CLOSES OFF AS IT APPROACHES THE MID ATLANTIC STATES. THIS WOULD
RESULT IN A PROLONGED PERIOD OF POST-FRONTAL RAIN INTO SAT. WITH
MAJORITY OF 00Z OPERATIONAL GUIDANCE TRENDING A BIT SLOWER...HAVE
ALSO TRENDED A BIT SLOWER WITH PRECIPITATION GRADUALLY TAPERING
OFF FRI AFTERNOON INTO FRI NIGHT. SUBSEQUENT MODEL TRENDS WILL
NEED TO BE CLOSELY MONITORED TO SEE IF THE FRONTAL SYSTEM SLOWS
DOWN EVEN FURTHER.
AS FOR THE SENSIBLE WEATHER...COLD FRONT SLOWLY CROSSES THE REGION
THU NIGHT INTO FRI. ALTHOUGH INSTABILITY WILL LIKELY BE FALLING TO
MARGINAL LEVELS THURSDAY NIGHT...WIDESPREAD SHOWER AND THUNDERSTORM
DEVELOPMENT IS LIKELY WITH ABUNDANT MOISTURE STREAMING AHEAD OF
APPROACHING SHORTWAVE ENERGY/COLD FRONT. THE SEVERE THREAT SHOULD
DIMINISH INTO THURSDAY NIGHT...WITH HEAVY RAIN THE MAIN THREAT
WITH PWATS ABOUT 2 STD ABOVE NORMAL AND STEERING FLOW NEARLY ALIGNED
WITH THE SLOW MOVING FRONT. WILL HAVE TO MONITOR THE EXTENT OF
INTERACTION OF THE FRONT WITH A SUBTROPICAL PLUME STREAMING UP THE
COAST THURSDAY NIGHT...WHICH IF CLOSER TO THE COAST WOULD ENHANCE
THE FLASH FLOOD THREAT. CONVECTIVE THREAT SHOULD DECREASE IN
THE WAKE OF THE COLD FRONT...BUT POTENTIAL WAVE DEVELOPMENT COULD
PROLONG LIGHT TO MODERATE POST-FRONTAL STRATIFORM RAINS THROUGH
FRIDAY INTO FRI NIGHT...PARTICULARLY ACROSS EASTERN SECTIONS.
AVERAGE BASIN RAINFALL SHOULD BE CLOSE TO AN INCH...WITH LOCALIZED
HIGHER AMOUNTS.
A DRYING NW FLOW SET UPS FRI NIGHT INTO SAT WITH STRONG COLD
ADVECTION. HIGH PRESSURE BUILDS ACROSS THE GREAT LAKES AND INTO
THE MID ATLANTIC STATES THROUGH EARLY NEXT WEEK WITH TEMPERATURES
SEVERAL DEGREES BELOW SEASONABLE LEVELS.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
FRONTAL BOUNDARY CONTINUES TO LINGER OVER THE AREA THIS MORNING.
AS A RESULT...HAVE GONE MORE PESSIMISTIC WITH THE FORECAST
THROUGH THE DAY...SHOWING IMPROVEMENT IN CIGS AND VSBY GENERALLY
AROUND 17Z-21Z. HOWEVER CONFIDENCE IN THIS
IMPROVEMENT...ESPECIALLY FOR CIGS...IS LOW. POTENTIAL FOR WINDS
TO STAY LIGHTER / MORE EASTERLY FOR A LONGER PERIOD THAN INDICATED
IN TAFS AS WELL.
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE THIS
AFTERNOON...GENERALLY AT KSWF AND PERHAPS KHPN. MARINE LAYER
LIKELY TO KEEP TS AWAY FROM TERMINALS FARTHER SE.
IT COULD BE ANOTHER TRICKY NIGHT FORECASTING VFR/IFR CONDITIONS.
LATEST GUIDANCE IS HINTING AT IFR OR LESS CONDITIONS AT THE
OUTLYING TERMINALS...HOWEVER GUIDANCE DIFFERS ON TIMING AND JUST
HOW LOW CIGS AND VSBYS GET. WILL HOLD OFF IN LOWERING CONDITIONS
TOO MUCH WITH LOW CONFIDENCE HOWEVER THIS WILL NEED TO BE
MONITORED. HIGHEST CONFIDENCE OF IFR OR LOWER CONDITIONS WILL BE
AT KGON.
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: LOW CONFIDENCE IN MUCH IMPROVEMENT AT
17Z...ESPECIALLY FOR CIGS. WINDS COULD STAY LIGHTER/MORE E FOR 1-2
HOURS LONGER THAN INDICATED IN TAF.
KLGA FCSTER COMMENTS: LOW CONFIDENCE IN MUCH IMPROVEMENT AT
17Z...ESPECIALLY FOR CIGS. WINDS COULD STAY LIGHTER/MORE E FOR 1-2
HOURS LONGER THAN INDICATED IN TAF.
KEWR FCSTER COMMENTS: LOW CONFIDENCE IN MUCH IMPROVEMENT AT
17Z...ESPECIALLY FOR CIGS. WINDS COULD STAY LIGHTER/MORE E FOR 1-2
HOURS LONGER THAN INDICATED IN TAF.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS YELLOW...WHICH IMPLIES
SLANT RANGE VISIBILITY 4-6SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: LOW CONFIDENCE IN MUCH IMPROVEMENT AT
17Z...ESPECIALLY FOR CIGS. WINDS COULD STAY LIGHTER FOR 1-2 HOURS
LONGER THAN INDICATED IN TAF.
KHPN FCSTER COMMENTS: LOW CONFIDENCE IN MUCH IMPROVEMENT AROUND
18-21Z...ESPECIALLY FOR CIGS.
KISP FCSTER COMMENTS: LOW POTENTIAL FOR CIGS/VSBY TO IMPROVE TO
MVFR OR HIGHER LEVELS AROUND 17-18Z. WIND SPEEDS MAY BE 1-2 HOURS
SLOWER TO INCREASE THAN SHOWN IN TAF.
.OUTLOOK FOR 12Z THURSDAY THROUGH SUNDAY...
.THURSDAY-FRIDAY...NUMEROUS SHRA AND TSTMS POSSIBLE. IFR POSSIBLE IN
FOG AND STRATUS.
.SATURDAY...RESIDUAL SHRA BEHIND A COLD FRONT WITH MVFR. BECOMING VFR
WITH NW WINDS INCREASING TO 20-30KT.
.SUNDAY...VFR WITH NW WINDS 20-25KT.
&&
.MARINE...
BASED ON HRRR AND LATEST TRENDS IN OBSERVATIONS AND WEB-CAMS HAVE
EXTENDED THE DENSE FOG ADVISORY FOR THE COASTAL OCEAN ZONES...NY
HARBOR AND THE SOUTH SHORE BAYS OF LONG ISLAND THROUGH 22Z. GIVEN
NO RESTRICTIONS OF 1NM OR LESS IN VISIBILITY EVIDENT ON SOUND OR
EASTERN BAYS OF LONG ISLAND...HAVE CANCELLED THE DENSE FOG
ADVISORY THERE.
THERE SEEMS TO BE INCREASING POTENIAL FOR DENSE FOG OVER THE
SOUTHERN WATERS TO CONTINUE TONIGHT. IF TRENDS HOLD...WILL EXTEND
THE DENSE FOG ADVISORY IN TIME THROUGH TONIGHT WITH THE LATE
AFTERNOON FORECAST ISSUANCE.
SEAS ARE NOT INCREASING AS FAST AS FORECAST...SO HAVE ADJUSTED
DOWNWARD A FOOT OR SO ACROSS MOST OCEAN AREAS INTO THIS EVENING.
SEAS SLOWLY BUILD THIS AFTERNOON/EVENING TO SCA LEVELS ON THE
COASTAL OCEAN WATERS AND REMAIN ABOVE SCA LEVELS THROUGH
THURSDAY. SW FLOW INCREASES OVER THE COASTAL OCEAN WATERS TONIGHT
AS WELL WITH SFC BOUNDARY LIFTING TO NEAR THE LONG ISLAND COAST IF
NOT FARTHER N.
A COLD FRONT WILL MOVE EAST ACROSS THE AREA WATERS LATE THURSDAY
THROUGH FRIDAY AFTERNOON...WITH HIGH PRESSURE BUILDING THROUGH THE
WEEKEND. WINDS SHOULD GRADUALLY FALL BELOW MARGINAL SCA LEVELS
THURSDAY NIGHT...WITH SCA SEAS ON THE OCEAN LIKELY REMAINING ABOVE
SCA CRITERIA THROUGH SATURDAY MORNING WITH RESIDUAL SOUTHERLY
SWELLS. UNDERCUT WAVEWATCH BY A FOOT DURING THIS TIME AS IT WAS
SLOWER BRINGING THE FRONTAL SYSTEM ACROSS THE AREA. THERE IS THOUGH
SOME UNCERTAINTY WITH THE SEAS DUE TO THE TIMING DIFFERENCES AMONGST
THE MODELS.
&&
.HYDROLOGY...
SCT SHOWERS/TSTMS THIS EVENING WILL BE CAPABLE OF PRODUCING
LOCALLY HEAVY RAINFALL...WITH THE BEST CHANCES NORTH/WEST OF NYC.
TOTAL BASIN AVG QPF FOR WED-THU COULD BE 1/4 TO 1/2 INCH...WITH
LOCALLY HIGHER AMOUNTS IN TSTMS.
SHOWERS AND THUNDERSTORMS AHEAD OF AN APPROACHING COLD FRONT LATE
THU INTO FRIDAY MORNING...SHOULD PRODUCE AVERAGE BASIN
RAINFALL AMOUNTS CLOSE TO AN INCH...WITH LOCALIZED HIGHER AMOUNTS.
THERE IS THE POTENTIAL FOR TRAINING OF THUNDERSTORMS WHICH COULD
RESULT IN FLASH FLOODING. ADDITIONAL LIGHTER RAINFALL AMOUNTS ARE
LIKELY FRIDAY...POSSIBLY INTO FRIDAY NIGHT.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ338-345-
350-353-355.
SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 6 PM EDT
THURSDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...MALOIT/24/NV
NEAR TERM...MALOIT
SHORT TERM...MALOIT/24
LONG TERM...NV
AVIATION...BC/PICCA
MARINE...MALOIT/24/NV
HYDROLOGY...24/NV
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1104 AM EDT WED MAY 22 2013
.SYNOPSIS...
A STALLED FRONT WILL REMAIN IN THE VICINITY INTO THURSDAY. A COLD
FRONT WILL THEN SLOWLY APPROACH FROM THE WEST THURSDAY...THEN PASS
THROUGH THURSDAY NIGHT INTO FRIDAY MORNING. CANADIAN HIGH PRESSURE
WILL THEN BUILD IN FOR THE MEMORIAL DAY WEEKEND AND EARLY NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HRRR IS THE ONLY MODEL WHICH SHOWS SHALLOW BACK DOOR FRONT MAKING
PROGRESS AS FAR TO THE S AND W AS IT DID...AND HOLDS THE FRONT
PRIMARILY TO OUT S AND W THROUGH MOST OF THE AFTERNOON. SUSPECT
THAT EVEN THE HRRR IS TOO FAST TO ERODE MARINE LAYER.
EXPECT MOST OF THE AREA TO BE CLOUDY THROUGH THE DAY AS A RESULT.
FOR NOW HAVE SIGNIFICANTLY SCALED BACK ON POPS FOR
TODAY...ESPECIALLY ACROSS THE SE 1/2 OF THE CWA...AND RESTRICTED
PROBABILITY OF THUNDER TO SLIGHT CHANCE AND THEN ONLY OVER NW
ZONES...AS STILL CANNOT RULE OUT CONVECTION FORMING OUTSIDE THE
CWA THEN MOVING IN.
TEMPERATURES LOWERED REFLECTING BLEND OF HRRR 2-METER TEMPERATURES
AND LAV GUIDANCE - WHICH IS NOT ALL THAT BAD. DID NOT GO AS WARM
AS THIS WOULD SUGGEST THOUGH OVER NW ZONES - GIVEN SUSPICION THAT
MARINE LAYER HOLDS ON. WILL HAVE BETTER IDEA WHICH WAY TO PLAY
NW/FAR W ZONES WITH NEXT UPDATE EARLY THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
HAVE CONCERN THAT IF THE MARINE LAYER DOES NOT DISSIPATE/FRONT
LIFT TO THE N BY THIS EVENING - THAT THE MARINE LAYER WILL
MAINTAIN ITSELF OVER MOST IF NOT ALL THE AREA TONIGHT. WILL
CONTINUE TO MONITOR TRENDS - BUT COULD END UP MAKING SIGNIFICANT
CHANGES TO TONIGHTS FORECAST IF CURRENT TRENDS HOLD.
SCT-ISOLD SHOWERS AND TSTMS THIS EVENING. CONVECTION SHOULD BE
SCATTERED AT BEST WITH ONLY MARGINAL INSTABILITY IN PLACE. SHOWERS
AND THUNDERSTORMS WILL BECOME MORE WIDESPREAD THURSDAY AS THE
UPPER LEVEL TROUGH AND ASSOCIATED SURFACE COLD FRONT APPROACH THE
AREA.
HIGHS ON THURSDAY IN THE MID TO UPPER 70S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
MAIN ISSUE FOR THE START OF THIS PERIOD IS THE INTERACTION OF THE
EASTWARD MOVING CENTRAL US TROUGH WITH SEVERAL NORTHERN STREAM
SHORTWAVES ROTATING AROUND A PERSISTENT EASTERN CANADIAN TROUGH. THE
COMPLEX INTERACTION IS RESULTING IN TIMING AND AMPLIFICATION ISSUES
AS THIS TROUGH SLIDES TO THE EAST COAST. GFS CONTINUES TO BE SLOWER
THAN ALL THE GUIDANCE FRI INTO SAT AS THE UPPER LOW NEGATIVELY TILTS
AND CLOSES OFF AS IT APPROACHES THE MID ATLANTIC STATES. THIS WOULD
RESULT IN A PROLONGED PERIOD OF POST-FRONTAL RAIN INTO SAT. WITH
MAJORITY OF 00Z OPERATIONAL GUIDANCE TRENDING A BIT SLOWER...HAVE
ALSO TRENDED A BIT SLOWER WITH PRECIPITATION GRADUALLY TAPERING
OFF FRI AFTERNOON INTO FRI NIGHT. SUBSEQUENT MODEL TRENDS WILL
NEED TO BE CLOSELY MONITORED TO SEE IF THE FRONTAL SYSTEM SLOWS
DOWN EVEN FURTHER.
AS FOR THE SENSIBLE WEATHER...COLD FRONT SLOWLY CROSSES THE REGION
THU NIGHT INTO FRI. ALTHOUGH INSTABILITY WILL LIKELY BE FALLING TO
MARGINAL LEVELS THURSDAY NIGHT...WIDESPREAD SHOWER AND THUNDERSTORM
DEVELOPMENT IS LIKELY WITH ABUNDANT MOISTURE STREAMING AHEAD OF
APPROACHING SHORTWAVE ENERGY/COLD FRONT. THE SEVERE THREAT SHOULD
DIMINISH INTO THURSDAY NIGHT...WITH HEAVY RAIN THE MAIN THREAT
WITH PWATS ABOUT 2 STD ABOVE NORMAL AND STEERING FLOW NEARLY ALIGNED
WITH THE SLOW MOVING FRONT. WILL HAVE TO MONITOR THE EXTENT OF
INTERACTION OF THE FRONT WITH A SUBTROPICAL PLUME STREAMING UP THE
COAST THURSDAY NIGHT...WHICH IF CLOSER TO THE COAST WOULD ENHANCE
THE FLASH FLOOD THREAT. CONVECTIVE THREAT SHOULD DECREASE IN
THE WAKE OF THE COLD FRONT...BUT POTENTIAL WAVE DEVELOPMENT COULD
PROLONG LIGHT TO MODERATE POST-FRONTAL STRATIFORM RAINS THROUGH
FRIDAY INTO FRI NIGHT...PARTICULARLY ACROSS EASTERN SECTIONS.
AVERAGE BASIN RAINFALL SHOULD BE CLOSE TO AN INCH...WITH LOCALIZED
HIGHER AMOUNTS.
A DRYING NW FLOW SET UPS FRI NIGHT INTO SAT WITH STRONG COLD
ADVECTION. HIGH PRESSURE BUILDS ACROSS THE GREAT LAKES AND INTO
THE MID ATLANTIC STATES THROUGH EARLY NEXT WEEK WITH TEMPERATURES
SEVERAL DEGREES BELOW SEASONABLE LEVELS.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
FRONTAL BOUNDARY CONTINUES TO LINGER OVER THE AREA THIS MORNING.
AS A RESULT...HAVE GONE MORE PESSIMISTIC WITH THE FORECAST
THROUGH THE DAY...SHOWING IMPROVEMENT IN CIGS AND VSBY GENERALLY
AROUND 17Z-21Z. HOWEVER CONFIDENCE IN THIS
IMPROVEMENT...ESPECIALLY FOR CIGS...IS LOW. POTENTIAL FOR WINDS
TO STAY LIGHTER / MORE EASTERLY FOR A LONGER PERIOD THAN INDICATED
IN TAFS AS WELL.
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE THIS
AFTERNOON...GENERALLY AT KSWF AND PERHAPS KHPN. MARINE LAYER
LIKELY TO KEEP TS AWAY FROM TERMINALS FARTHER SE.
IT COULD BE ANOTHER TRICKY NIGHT FORECASTING VFR/IFR CONDITIONS.
LATEST GUIDANCE IS HINTING AT IFR OR LESS CONDITIONS AT THE
OUTLYING TERMINALS...HOWEVER GUIDANCE DIFFERS ON TIMING AND JUST
HOW LOW CIGS AND VSBYS GET. WILL HOLD OFF IN LOWERING CONDITIONS
TOO MUCH WITH LOW CONFIDENCE HOWEVER THIS WILL NEED TO BE
MONITORED. HIGHEST CONFIDENCE OF IFR OR LOWER CONDITIONS WILL BE
AT KGON.
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: LOW CONFIDENCE IN MUCH IMPROVEMENT AT
17Z...ESPECIALLY FOR CIGS. WINDS COULD STAY LIGHTER/MORE E FOR 1-2
HOURS LONGER THAN INDICATED IN TAF.
KLGA FCSTER COMMENTS: LOW CONFIDENCE IN MUCH IMPROVEMENT AT
17Z...ESPECIALLY FOR CIGS. WINDS COULD STAY LIGHTER/MORE E FOR 1-2
HOURS LONGER THAN INDICATED IN TAF.
KEWR FCSTER COMMENTS: LOW CONFIDENCE IN MUCH IMPROVEMENT AT
17Z...ESPECIALLY FOR CIGS. WINDS COULD STAY LIGHTER/MORE E FOR 1-2
HOURS LONGER THAN INDICATED IN TAF.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS YELLOW...WHICH IMPLIES
SLANT RANGE VISIBILITY 4-6SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: LOW CONFIDENCE IN MUCH IMPROVEMENT AT
17Z...ESPECIALLY FOR CIGS. WINDS COULD STAY LIGHTER FOR 1-2 HOURS
LONGER THAN INDICATED IN TAF.
KHPN FCSTER COMMENTS: LOW CONFIDENCE IN MUCH IMPROVEMENT AROUND
18-21Z...ESPECIALLY FOR CIGS.
KISP FCSTER COMMENTS: LOW POTENTIAL FOR CIGS/VSBY TO IMPROVE TO
MVFR OR HIGHER LEVELS AROUND 17-18Z. WIND SPEEDS MAY BE 1-2 HOURS
SLOWER TO INCREASE THAN SHOWN IN TAF.
.OUTLOOK FOR 12Z THURSDAY THROUGH SUNDAY...
.THURSDAY-FRIDAY...NUMEROUS SHRA AND TSTMS POSSIBLE. IFR POSSIBLE IN
FOG AND STRATUS.
.SATURDAY...RESIDUAL SHRA BEHIND A COLD FRONT WITH MVFR. BECOMING VFR
WITH NW WINDS INCREASING TO 20-30KT.
.SUNDAY...VFR WITH NW WINDS 20-25KT.
&&
.MARINE...
BASED ON HRRR AND LATEST TRENDS IN OBSERVATIONS AND WEB-CAMS HAVE
EXTENDED THE DENSE FOG ADVISORY FOR THE COASTAL OCEAN ZONES...NY
HARBOR AND THE SOUTH SHORE BAYS OF LONG ISLAND THROUGH 22Z. GIVEN
NO RESTRICTIONS OF 1NM OR LESS IN VISIBILITY EVIDENT ON SOUND OR
EASTERN BAYS OF LONG ISLAND...HAVE CANCELLED THE DENSE FOG
ADVISORY THERE.
SEAS ARE NOT INCREASING AS FAST AS FORECAST...SO HAVE ADJUSTED
DOWNWARD A FOOT OR SO ACROSS MOST OCEAN AREAS INTO THIS EVENING.
SEAS SLOWLY BUILD THIS AFTERNOON/EVENING N TO SCA LEVELS AND
REMAIN ABOVE SCA LEVELS THROUGH THURSDAY. SW FLOW INCREASES OVER THE
COASTAL OCEAN WATERS TONIGHT AS WELL WITH SFC BOUNDARY LIFTING TO
NEAR THE LONG ISLAND COAST IF NOT FARTHER N.
A COLD FRONT WILL MOVE EAST ACROSS THE AREA WATERS LATE THURSDAY
THROUGH FRIDAY AFTERNOON...WITH HIGH PRESSURE BUILDING THROUGH THE
WEEKEND. WINDS SHOULD GRADUALLY FALL BELOW MARGINAL SCA LEVELS
THURSDAY NIGHT...WITH SCA SEAS ON THE OCEAN LIKELY REMAINING ABOVE
SCA CRITERIA THROUGH SATURDAY MORNING WITH RESIDUAL SOUTHERLY
SWELLS. UNDERCUT WAVEWATCH BY A FOOT DURING THIS TIME AS IT WAS
SLOWER BRINGING THE FRONTAL SYSTEM ACROSS THE AREA. THERE IS THOUGH
SOME UNCERTAINTY WITH THE SEAS DUE TO THE TIMING DIFFERENCES AMONGST
THE MODELS.
&&
.HYDROLOGY...
SCT SHOWERS/TSTMS THIS EVENING WILL BE CAPABLE OF PRODUCING
LOCALLY HEAVY RAINFALL...WITH THE BEST CHANCES NORTH/WEST OF NYC.
TOTAL BASIN AVG QPF FOR WED-THU COULD BE 1/4 TO 1/2 INCH...WITH
LOCALLY HIGHER AMOUNTS IN TSTMS.
SHOWERS AND THUNDERSTORMS AHEAD OF AN APPROACHING COLD FRONT LATE
THU INTO FRIDAY MORNING...SHOULD PRODUCE AVERAGE BASIN
RAINFALL AMOUNTS CLOSE TO AN INCH...WITH LOCALIZED HIGHER AMOUNTS.
THERE IS THE POTENTIAL FOR TRAINING OF THUNDERSTORMS WHICH COULD
RESULT IN FLASH FLOODING. ADDITIONAL LIGHTER RAINFALL AMOUNTS ARE
LIKELY FRIDAY...POSSIBLY INTO FRIDAY NIGHT.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ338-345-
350-353-355.
SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 6 PM EDT
THURSDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...24/NV
NEAR TERM...24/MALOIT/NV
SHORT TERM...24
LONG TERM...NV
AVIATION...BC/PICCA
MARINE...24/MALOIT/NV
HYDROLOGY...24/NV
AREA FORECAST DISCUSSION
NWS ALBANY NY
1047 AM EDT WED MAY 22 2013
.SYNOPSIS...
LOW PRESSURE WILL MOVE FROM THE GREAT LAKES REGION TODAY
INTO THE SAINT LAWRENCE VALLEY TOMORROW. WARM AND HUMID CONDITIONS
WILL PERSIST INTO THURSDAY WITH SHOWERS AND THUNDERSTORMS. A STRONG
COLD FRONT WILL MOVE SLOWLY THROUGH NEW YORK AND NEW ENGLAND INTO
THURSDAY NIGHT. LOW PRESSURE WILL FORM ALONG THIS FRONT ON THE COAST
FRIDAY...AS MUCH COLDER AIR POURS INTO THE REGION...AS THE WEATHER
MAY STAY UNSETTLED INTO THE FIRST HALF OF THE MEMORIAL DAY WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 AM EDT... A STATIONARY FRONT REMAINS OVER ERN NY AND WRN
NEW ENGLAND...AS IT APPEARS IT WILL BEGIN TO LIFT TO THE N/NE INTO
THE EARLY PM...AS A SHORT-WAVE WITH SOME SCT SHOWERS AND ISOLD
THUNDERSTORMS IS APPROACHING FROM WRN-CNTRL NY. THE POPS ARE
GRADUALLY INCREASED IN THE LATE MORNING INTO THE EARLY PM.
STRATUS IS HANGING TOUGH THIS MORNING...AND SHOULD GRADUALLY ERODE
FROM SW TO NE. THE IS A BETTER AREA OF CLEARING OVER THE OH
VALLEY. THERE IS YET...ANOTHER SHORT-WAVE MOVING TOWARD WRN PA.
THIS DISTURBANCE MAY INCREASE THE POTENTIAL FOR SEVERE WX IN THE
LATE PM/EARLY EVENING...ESPECIALLY OVER WRN NY
WE HAVE BACK OFF THE SVR WX WORDING UNTIL AFTER 3 PM IN THE HOURLY
GRIDS. THE SVR POTENTIAL WILL HINGE ON MORE SHEAR...AND LESSER
AMOUNTS OF INSTABILITY. THE LATEST EXPERIMENTAL HRRR FROM THE SPC
MESOANALYSIS PAGE SHOWS 40-50 KTS OF BULK SHEAR IN THE 0-6 KM
LAYER FROM THE CAPITAL REGION NORTH...AND AND 30-40 KTS TO THE
SOUTHEAST. INSTABILITY VALUES OFF THE 12Z NAM ARE GENERALLY
1000-1500 J/KG WITH SLIGHTLY HIGHER POCKETS OF SBCAPE. MID LEVEL
LAPSE RATES ARE IN THE 6-6.5 C/KM RANGE.
A NEW RUNNING OF THE LOCAL MAGLENTA SEVERE WEATHER INDEX SHOWS A
MINOR SEVERE EVENT WITH THE FOLLOWING VALUES PLUGGED IN:
CAPE=1000 K/KG
MAX SOUNDING WINDS=50 KTS
EHI=1.0
STORM SPEED= 35 KTS
0-3 KM SRH = 100 (M/S)^2
IF THE CAPE IS INCREASED TO 1500 J/KG...WE SHOW A MAJOR EVENT.
THE CONVECTIVE MODE WOULD INDICATE SOME MULTICELLS AND OR ISOLD
SUPERCELLS...POTENTIALLY CONGEALING INTO CLUSTERS AND LINES. THE
SATELLITE TRENDS WILL BE MONITORED CAREFULLY.
OUR LOCAL WRF SHOWS A FEW CLUSTERS DEVELOPING IN THE 0-3 KM
COLUMNAR REF PRODUCT IN THE EARLY TO MID PM...AND CONTINUING OVERNIGHT.
THE EXPERIMENTAL HRRR INDICATES LATE PM/EARLY PM.W
PWATS WILL CONTINUE TO RUN A FEW STANDARD DEVIATIONS ABOVE NORMAL
WITH VALUES OF 1.25-1.75 INCH RANGE...SO SOME HEAVY DOWNPOURS ARE POSSIBLE.
OVERALL..THE SLIGHT RISK FOR OUR AREA LOOKS FINE...AND WE WILL
CONTINUE TO MONITOR THE NEAR TERM TRENDS. MAX TEMPS IN THE M70S TO
M80S LOOK FINE FOR NOW.
CONVECTION WILL CONTINUE INTO THE EVNG HOURS AND DIM OVERNIGHT AS
FCA IS FIRMLY IN WARM SECTION. LOWS AND TD WILL BE IN THE
60S...AND AREAS OF PATCHY FOG POSSIBLE IN THE MORNING.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
THU AND THU NT 500HPA TROF STARTS MOVING E THROUGH GRTLKS AS SFC
LOW ORGANIZES ALONG SEMI-STALLED FRONT FROM FM LK ERIE UP ST
LAWRENCE VLY. THIS SYSTEM PUSHES SLOWLY EAST DRAGGING A CDFNT TO
BTV-SYR LINE THU AFTN...AND THROUGH FCA BY 12UTC FRI. NAM/GFS IN
PRETTY CLOSE AGREEMENT WITH THIS TIMING. WHILE THERE IS INCRG
DYNAMICS WITH APPROACHING JET AND TROF...CAPES 1000-1500 ...CLOUDS
WILL BE WIDESPREAD HOLDING MAX TEMPS TO MID 70S TO AROUND 80. SPC HAS
ONLY PUT AREA IN SEE TEXT ATTM...WITH LOW PROBS DUE TO LIMITED INSTABILITY.
REGARDLESS AREA WILL SEE PERIOD OF -SHRA/TSTMS INCRG THU...TRANSITIONING
TO -SHRA/-RA BEHIND THE CDFNT OVERNIGHT.
BY FRI MORNING CDFNT WILL BE IN I-95 CORRIDOR ALONG THE ATLC
COAST. 500HPA TROF WILL BE MOVING INTO NE USA...AND BOTH MODELS
DEVELOP A MODEST SFC LOW OVER NJ. THE WARMTH OF PAST FEW DAYS
WILL GIVE WAY TO A COOL BREEZY WITH -SHRA FRI. FINALLY SFC LOW
MOVES OFFSHORE FRI NT AS HIGH PRESSURE BUILDS INTO THE GRTLKS.
HWVR THE 500HPA TROF LINGERS AND CUTS OFF OVER NEW ENG SAT.
BETWEEN THESE TWO SYSTEMS A BRISK NW GRADIENT WILL DRIVE SOME
PRETTY COOL AIR INTO THE REGION FOR LATE MAY. WITH 500HPA CUT OFF
LINGERING SKIES MAY ONLY BE PS SAT IN GFS.
TEMPS WILL PROBABLY GO NOWHERE FRI...ONLY COMING OFF MORNING LOWS
A FEW DEG...OR HOLDING STEADY.
THE GFS/NAM ARE PROGRESSIVE WITH SFC LOW DEPARTING THE COAST FRI
NT...WITH ITS 500 HPA TROF CROSSING REGION SAT AND DEPARTING SAT
NT WITH PC SKIES AND A RATHER BRISK WIND GRADIENT.
THE 00UTC ECMWF CUTS OFF THE 500HPA LOW OVER NJ...DEVELOPS A
COASTAL LOW...WHICH LINGERS ALONG THE EAST COAST FOR THE WEEKEND
WITH PERIODS OF RAW CHILLY RAIN.
THE GFS TEMPS WOULD BRING MINS SAT MORNING INTO THE MID 30S TO
MID 40S WITH SOME NEAR 30 AND POTENTIAL FROST/FREEZE ISSUES IN
ADRNDKS. HIGHS SAT WILL ONLY REBOUND EVEN WITH THE STRONG SUN TO
THE 60S. LOWS SAT NIGHT WOULD AGAIN BE IN THE 30S. WINDS WILL
REMAIN BRISK. ECMWF WOULD RESULT IN SLIGHTLY WARMER NIGHT TIME
TEMPS AND COOLER YET DAYTIME TEMPS IN MID 50S TO LOW 60S. HPC
LEANS TWRD A BLEND WITH CHC POPS LINGERING INTO SAT. IT WILL BE A
FALL LIKE MEMORIAL DAY WEEKEND.
WILL LEAN TWRD GFS/HPC BLEND THROUGH SAT.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
THE ECMWF KEEPS THE 500HPA CUTOFF OVER RGN AND SFC LOW NEAR NEW
ENGLAND COAST FOR A RAW CHILLY WEEKEND...FINALLY CLEARING ON
MONDAY. HWVR AT THIS TIME ITS TO BE CONSIDERED AN OUTLIER.
GFS/NAM/HPC PROGRESSIVELY MOVE THIS SYSTEM ALONG. 17 OF 20
MEMBERS OF THE GEFS ENSEMBLE KEEP IT DRY FROM FRI NIGHT ONWARD.
ONLY 3 HAVE ANY QPF. SO THE WORST CASE IN THE GFS IS SOME CLOUDS
FOR SUNDAY MRNG. OVERALL THE SFC HIGH BUILDS INTO THE GRTLKS
SHIFTING SLOWLY EAST TO FCA BY TUES. AT 500 HPA RIDGE BUILDS FROM
GRT PLAINS TO GRTLKS.
PERIOD WILL START OFF PARTLY CLOUDY W/BLO NORMAL TEMPS AND A BREEZE
CONTINUING SUNDAY. SCT FROST AND FREEZE WILL BE POSSIBLE IN THE
HIR TRRN. IN TIME THIS WILL GIVE WAY TO BRILLIANT SUNSHINE MONDAY
AND TUESDAY...LIGHT WINDS AND TEMPS RETURNING TO NORMAL MONDAY AND
ABV BY TUESDAY AND WED.
WILL POPULATE WITH HPC MIDNIGHT SHIFT GUID.
THE GROWING SEASON IS UNDERWAY ACROSS THE MID HUDSON VALLEY...
GREATER CAPITAL DISTRICT...LAKE GEORGE SARATOGA REGION...THE
MOHAWK VALLEY...EASTERN CATSKILLS...TACONICS...BERKSHIRES...BENNINGTON
AND EASTERN WINDHAM COUNTIES VT AND LITCHFIELD COUNTY. IT WILL
START ON MAY 25TH FOR THE SOUTHERN ADIRONDACKS AND WESTERN WINDHAM
COUNTY.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
SOME LOW CLOUDS ARE AFFECTING MOST OF THE TAF SITE THIS
MORNING...WITH IFR SCATTERED VARIABLE BROKEN AT KALB...SOLID IFR
AT KPSF AND KGFL AND SOLID MVFR AT KPOU. SOME FOG IS OCCURRING AT
KPSF. THE LOW CLOUDS AND FOG SHOULD LIFT BTWN 13-15Z...LEAVING A
MIX OF CLOUDS ABOVE 3000 FEET AGL FOR THE REST OF THE DAY AT ALL
SITES.
THUNDERSTORMS SHOULD DEVELOP AGAIN THIS AFTERNOON AND CONTINUE MUCH
OF TONIGHT...BUT DUE TO THE SCATTERED NATURE...JUST PUTTING VCSH
UNTIL REGIONS OF THUNDERSTORM DEVELOPMENT CAN BE OBSERVED AND
MOVEMENT CAN BE TRACKED LATER TODAY. WHEREVER THUNDERSTORMS
OCCUR...MVFR AND IFR CONDITIONS WILL OCCUR BUT AGAIN...SCATTERED
NATURE TO THUNDERSTORMS PREVENTING ACKNOWLEDGING IN TAFS FOR NOW.
WINDS SHOULD BE SOUTH TO SOUTHWEST AT 10 KT OR LESS TODAY...
DIMINISHING TO LESS THAN 10 KT TONIGHT.
OUTLOOK...
THU...MVFR WITH IFR POSSIBLE. -SHRA/-TSRA LIKELY.
THU NIGHT...VFR/MVFR. CHC -SHRA/-TSRA ESPECIALLY IN THE EVNG.
FRI...MAINLY VFR. CHC -TSRA MAINLY IN THE AM.
SAT-SUN...VFR. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS THROUGH FRIDAY. OCCASIONAL SHOWERS AND
THUNDERSTORMS WILL CONTINUE THROUGH THURSDAY NIGHT. SHOWERS WILL
CONTINUE INTO FRIDAY.
RH VALUES WILL INCREASE TO 85 TO 100 PERCENT TONIGHT...AND
THURSDAY NIGHT...AND LOWER TO 45 TO 60 PERCENT THIS AFTERNOON.
WINDS WILL MAINLY LESS THAN 10 MPH THROUGH TONIGHT...BECOMING
SOUTHWEST AROUND 10MPH THURSDAY.
&&
.HYDROLOGY...
PWATS ON THE ORDER OF 1.5 TO 2.0 INCHES NEXT FEW DAYS. WHILE
WIDESPREAD FLOODING IS NOT ANTICIPATED...LOCALLY HEAVY RAINFALL IN
THUNDERSTORMS AND TRAINING COULD RESULT IN SMALL STREAM AND URBAN
FLOODING OVERNIGHT AND AGAIN THIS AFTERNOON. SIGNIFICANT WITHIN
BANK RISES ARE LIKELY IN LARGER RIVERS.
3-HR ZONAL FFG VALUES ARE GENERALLY IN THE 2.5-3.0 INCH RANGE AT
THIS TIME...WHICH ARE HIGH FOR MID TO LATE MAY.
DUE TO THE SCATTERED NATURE OF THE SHOWERS AND THUNDERSTORMS...
BASIN AVERAGE QPF WILL BE HIGHLY VARIABLE THIS WEEK. THE BEST
THREAT FOR SEEING SIGNIFICANT AMOUNTS OF SHOWERS OR THUNDERSTORMS
WILL THIS AFTERNOON INTO THURSDAY NIGHT.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SNYDER/WASULA
NEAR TERM...SNYDER/WASULA
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...NAS/WASULA
FIRE WEATHER...SNYDER
HYDROLOGY...SNYDER
AREA FORECAST DISCUSSION
NWS ALBANY NY
800 AM EDT WED MAY 22 2013
.SYNOPSIS...
LOW PRESSURE WILL MOVE FROM THE GREAT LAKES REGION TODAY INTO THE
SAINT LAWRENCE VALLEY THURSDAY. WARM HUMID CONDITIONS WILL PERSIST
INTO THURSDAY WITH SHOWERS AND THUNDERSTORMS. THURSDAY A STRONG
COLD FRONT WILL PUSH SLOWLY THROUGH NEW YORK AND NEW ENGLAND. LOW
PRESSURE WILL FORM ALONG THIS FRONT ON THE COAST FRIDAY...AS MUCH
COLDER AIR POURS INTO THE REGION. FRIDAY NIGHT THE STORM WILL MOVE
OFFSHORE AS HIGH PRESSURE BUILDS INTO THE GREAT LAKES REGION FOR
THE MEMORIAL DAY WEEKEND. IT WILL BRING FAIR WEATHER WITH
UNSEASONABLY COOL TEMPERATURES FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
TSTMS HAVE ENDED AND ONLY SCT -SHRA REMAIN MAINLY OVER S VT AND
BERKSHIRE COUNTY. SOME ISOLD -SHRA ARE ALONG THE S TIER. FOR THE
NEXT SVRL HOURS MOST OF THIS ACTIVITY WILL DIMINISH AND END.
CLOUDS OVER MUCH OF FCA WILL THIN WITH INCRG SUNSHINE FOR A FEW
HRS.
THE HOOSIC RIVER AND SOME SMALL STREAMS IN SOUTHERN VERMONT HAVE
REACHED BANK FULL AND MAY BRIEFLY EXCEED FLOOD THIS MORNING BEFORE
RECEDING. WARNINGS AND ADVISORIES HAVE BEEN ISSUED TO COVER THESE
SITUATIONS.
AT SFC WMFNT IS N OF FCA. IT WILL MOVE TO ST LAWRENCE VLY TO
MICHIGAN LINE...AS WEAK LOW PRESSURE FORMS ALONG AND PROPAGATES UP
IT TODAY. THIS LEAVES FCA IN WARM SECTOR WITH ALOT OF RESIDUAL
LLVL MOISTURE/CLOUDS FM TUES CONVECTION
WITH TD IN 60S...TEMPS REBOUNDING TO 80S...VRBL CLOUDS THE THREAT
OF TSTMS INCREASES THROUGH THE DAY. LOCAL WRF/HRRR WHICH HANDLED
TODAYS EVENT WELL...SHOW A MAINLY CELLULAR AND PULSE RESPONSE
TODAY IN SIMULATED REFL. GFS PRODUCES SFC CAPES ON THE ORDER OF
1000-2000 J/KG THE NAM 2000-4000 J/KG WITH A DEFINE PREFERENCE
FROM THE CAPITAL DISTRICT S & E AND THE MHWK VLY.
NAM AND GFS SHOW H850-700 LAPSE RATES AROUND 6.5 THIS AFTN.
GOING TO HRRR FOR THE LATE AFTN:
POU/ALB/GFL
CAPE 2000/1812/1777
J/KG MAX WIND 33/33/40 EHI OF 1.6/1.5/1.2
STORM SPEED 24/18/18
SRH 175/156/106
MAGLENTA 1.75/2.17/2.44 ALL MAJOR SEVERE
WHICH IS CONSIDERABLY STRONGER LOOKING THAN HRRR REFL. THE NAM
MODEL SOUNDINGS AND WRF MODEL SOUNDINGS ARE CONSIDERABLY LOWER IN
CAPE AROUND 1000-1200 J/KG.
PWATS WILL CONTINUE TO RUN A FEW STANDARD DEVIATIONS ABOVE NORMAL
WITH VALUES OF 1.50-1.8 INCHES.
SOME OTHER CONSIDERATIONS LLVL JET AT H850 HPA IS 25-35KTS...AND
BULK OF IT MAY PASS WEST OF FCA. THERE IS LITTLE ADDITIONAL UPPER
FORCING. SPC HAS OUTLOOKED NY PORTIONS OF FCA AT THIS POINT WILL
NOT TRY TO GET SPECIFIC...WILL GO WITH ENHANCED WORDING TODAY. IF
THERES A PREFERRED AREA IT WOULD MHWK VLY AND S...AND A PREFERRED
TIME OF LATER IN THE AFTN AND EVENING.
CONVECTION WILL CONTINUE INTO THE EVNG HOURS AND DIM OVERNIGHT AS
FCA IS FIRMLY IN WARM SECTION. LOWS AND TD WILL BE IN THE
60S...AND AREAS OF PATCHY FOG POSSIBLE IN THE MORNING.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
THU AND THU NT 500HPA TROF STARTS MOVING E THROUGH GRTLKS AS SFC
LOW ORGANIZES ALONG SEMI-STALLED FRONT FROM FM LK ERIE UP ST
LAWRENCE VLY. THIS SYSTEM PUSHES SLOWLY EAST DRAGGING A CDFNT TO
BTV-SYR LINE THU AFTN...AND THROUGH FCA BY 12UTC FRI. NAM/GFS IN
PRETTY CLOSE AGREEMENT WITH THIS TIMING. WHILE THERE IS INCRG
DYNAMICS WITH APPROACHING JET AND TROF...CAPES 1000-1500 ...CLOUDS
WILL BE WIDESPREAD HOLDING MAX TEMPS TO MID 70S TO AROUND 80. SPC HAS
ONLY PUT AREA IN SEE TEXT ATTM...WITH LOW PROBS DUE TO LIMITED INSTABILITY.
REGARDLESS AREA WILL SEE PERIOD OF -SHRA/TSTMS INCRG THU...TRANSITIONING
TO -SHRA/-RA BEHIND THE CDFNT OVERNIGHT.
BY FRI MORNING CDFNT WILL BE IN I-95 CORRIDOR ALONG THE ATLC
COAST. 500HPA TROF WILL BE MOVING INTO NE USA...AND BOTH MODELS
DEVELOP A MODEST SFC LOW OVER NJ. THE WARMTH OF PAST FEW DAYS
WILL GIVE WAY TO A COOL BREEZY WITH -SHRA FRI. FINALLY SFC LOW
MOVES OFFSHORE FRI NT AS HIGH PRESSURE BUILDS INTO THE GRTLKS.
HWVR THE 500HPA TROF LINGERS AND CUTS OFF OVER NEW ENG SAT.
BETWEEN THESE TWO SYSTEMS A BRISK NW GRADIENT WILL DRIVE SOME
PRETTY COOL AIR INTO THE REGION FOR LATE MAY. WITH 500HPA CUT OFF
LINGERING SKIES MAY ONLY BE PS SAT IN GFS.
TEMPS WILL PROBABLY GO NOWHERE FRI...ONLY COMING OFF MORNING LOWS
A FEW DEG...OR HOLDING STEADY.
THE GFS/NAM ARE PROGRESSIVE WITH SFC LOW DEPARTING THE COAST FRI
NT...WITH ITS 500 HPA TROF CROSSING REGION SAT AND DEPARTING SAT
NT WITH PC SKIES AND A RATHER BRISK WIND GRADIENT.
THE 00UTC ECMWF CUTS OFF THE 500HPA LOW OVER NJ...DEVELOPS A
COASTAL LOW...WHICH LINGERS ALONG THE EAST COAST FOR THE WEEKEND
WITH PERIODS OF RAW CHILLY RAIN.
THE GFS TEMPS WOULD BRING MINS SAT MORNING INTO THE MID 30S TO
MID 40S WITH SOME NEAR 30 AND POTENTIAL FROST/FREEZE ISSUES IN
ADRNDKS. HIGHS SAT WILL ONLY REBOUND EVEN WITH THE STRONG SUN TO
THE 60S. LOWS SAT NIGHT WOULD AGAIN BE IN THE 30S. WINDS WILL
REMAIN BRISK. ECMWF WOULD RESULT IN SLIGHTLY WARMER NIGHT TIME
TEMPS AND COOLER YET DAYTIME TEMPS IN MID 50S TO LOW 60S. HPC
LEANS TWRD A BLEND WITH CHC POPS LINGERING INTO SAT. IT WILL BE A
FALL LIKE MEMORIAL DAY WEEKEND.
WILL LEAN TWRD GFS/HPC BLEND THROUGH SAT.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
THE ECMWF KEEPS THE 500HPA CUTOFF OVER RGN AND SFC LOW NEAR NEW
ENGLAND COAST FOR A RAW CHILLY WEEKEND...FINALLY CLEARING ON
MONDAY. HWVR AT THIS TIME ITS TO BE CONSIDERED AN OUTLIER.
GFS/NAM/HPC PROGRESSIVELY MOVE THIS SYSTEM ALONG. 17 OF 20
MEMBERS OF THE GEFS ENSEMBLE KEEP IT DRY FROM FRI NIGHT ONWARD.
ONLY 3 HAVE ANY QPF. SO THE WORST CASE IN THE GFS IS SOME CLOUDS
FOR SUNDAY MRNG. OVERALL THE SFC HIGH BUILDS INTO THE GRTLKS
SHIFTING SLOWLY EAST TO FCA BY TUES. AT 500 HPA RIDGE BUILDS FROM
GRT PLAINS TO GRTLKS.
PERIOD WILL START OFF PARTLY CLOUDY W/BLO NORMAL TEMPS AND A BREEZE
CONTINUING SUNDAY. SCT FROST AND FREEZE WILL BE POSSIBLE IN THE
HIR TRRN. IN TIME THIS WILL GIVE WAY TO BRILLIANT SUNSHINE MONDAY
AND TUESDAY...LIGHT WINDS AND TEMPS RETURNING TO NORMAL MONDAY AND
ABV BY TUESDAY AND WED.
WILL POPULATE WITH HPC MIDNIGHT SHIFT GUID.
THE GROWING SEASON IS UNDERWAY ACROSS THE MID HUDSON VALLEY...
GREATER CAPITAL DISTRICT...LAKE GEORGE SARATOGA REGION...THE
MOHAWK VALLEY...EASTERN CATSKILLS...TACONICS...BERKSHIRES...BENNINGTON
AND EASTERN WINDHAM COUNTIES VT AND LITCHFIELD COUNTY. IT WILL
START ON MAY 25TH FOR THE SOUTHERN ADIRONDACKS AND WESTERN WINDHAM
COUNTY.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
SOME LOW CLOUDS ARE AFFECTING MOST OF THE TAF SITE THIS
MORNING...WITH IFR SCATTERED VARIABLE BROKEN AT KALB...SOLID IFR
AT KPSF AND KGFL AND SOLID MVFR AT KPOU. SOME FOG IS OCCURRING AT
KPSF. THE LOW CLOUDS AND FOG SHOULD LIFT BTWN 13-15Z...LEAVING A
MIX OF CLOUDS ABOVE 3000 FEET AGL FOR THE REST OF THE DAY AT ALL
SITES.
THUNDERSTORMS SHOULD DEVELOP AGAIN THIS AFTERNOON AND CONTINUE MUCH
OF TONIGHT...BUT DUE TO THE SCATTERED NATURE...JUST PUTTING VCSH
UNTIL REGIONS OF THUNDERSTORM DEVELOPMENT CAN BE OBSERVED AND
MOVEMENT CAN BE TRACKED LATER TODAY. WHEREVER THUNDERSTORMS
OCCUR...MVFR AND IFR CONDITIONS WILL OCCUR BUT AGAIN...SCATTERED
NATURE TO THUNDERSTORMS PREVENTING ACKNOWLEDGING IN TAFS FOR NOW.
WINDS SHOULD BE SOUTH TO SOUTHWEST AT 10 KT OR LESS TODAY...
DIMINISHING TO LESS THAN 10 KT TONIGHT.
OUTLOOK...
THU...MVFR WITH IFR POSSIBLE. -SHRA/-TSRA LIKELY.
THU NIGHT...VFR/MVFR. CHC -SHRA/-TSRA ESPECIALLY IN THE EVNG.
FRI...MAINLY VFR. CHC -TSRA MAINLY IN THE AM.
SAT-SUN...VFR. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS THROUGH FRIDAY. OCCASIONAL SHOWERS AND
THUNDERSTORMS WILL CONTINUE THROUGH THURSDAY NIGHT. SHOWERS WILL
CONTINUE INTO FRIDAY.
RH VALUES WILL INCREASE TO 85 TO 100 PERCENT TONIGHT...AND
THURSDAY NIGHT...AND LOWER TO 45 TO 60 PERCENT THIS AFTERNOON.
WINDS WILL MAINLY LESS THAN 10 MPH THROUGH TONIGHT...BECOMING
SOUTHWEST AROUND 10MPH THURSDAY.
&&
.HYDROLOGY...
PWATS ON THE ORDER OF 1.5 TO 2.0 INCHES NEXT FEW DAYS. WHILE
WIDESPREAD FLOODING IS NOT ANTICIPATED...LOCALLY HEAVY RAINFALL IN
THUNDERSTORMS AND TRAINING COULD RESULT IN SMALL STREAM AND URBAN
FLOODING OVERNIGHT AND AGAIN THIS AFTERNOON. SIGNIFICANT WITHIN
BANK RISES ARE LIKELY IN LARGER RIVERS.
3-HR ZONAL FFG VALUES ARE GENERALLY IN THE 2.5-3.0 INCH RANGE AT
THIS TIME...WHICH ARE HIGH FOR MID TO LATE MAY.
DUE TO THE SCATTERED NATURE OF THE SHOWERS AND THUNDERSTORMS...
BASIN AVERAGE QPF WILL BE HIGHLY VARIABLE THIS WEEK. THE BEST
THREAT FOR SEEING SIGNIFICANT AMOUNTS OF SHOWERS OR THUNDERSTORMS
WILL THIS AFTERNOON INTO THURSDAY NIGHT.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SNYDER
NEAR TERM...SNYDER
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...NAS/WASULA
FIRE WEATHER...SNYDER
HYDROLOGY...SNYDER
AREA FORECAST DISCUSSION
NWS TAUNTON MA
729 AM EDT WED MAY 22 2013
.SYNOPSIS...
A STALLED FRONT WILL MOVE BACK NORTH AS A WARM FRONT TODAY. WARM
AND HUMID CONDITIONS CONTINUE INTO THURSDAY AND FRIDAY WITH
SHOWERS AND SCATTERED STRONG THUNDERSTORMS POSSIBLE. COOLER AND
LESS HUMID CONDITIONS ARE EXPECTED FOR THIS HOLIDAY WEEKEND AS
HIGH PRESSURE BUILDS ACROSS THE NORTHEAST.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
730 AM UPDATE...
CONVECTION IS FINALLY DYING DOWN AS IT ENTERS INTO ALREADY WORKED
OVER AIR. EXPECT PRECIP TO CONTINUE TO MOVE EASTWARD AND
DISSIPATE. TEMPS ARE SLOW TO REBOUND THIS MORNING...BUT WITH
WINDS SOUTH OF THE PIKE ALREADY SWITCHING TO THE SW...EXPECT TEMPS
TO JUMP LATER THIS MORNING. OTHERWISE BULK OF THE FORECAST REMAINS
ON TRACK AS STRONG TO SEVERE WEATHER IS STILL ANTICIPATED ACROSS
THE WESTERN HALF OF THE REGION.
PREVIOUS DISCUSSION...
CONTINUING TO MONITOR WAVES OF CONVECTION THIS MORNING. LATEST
RUNS OF THE HRRR APPEAR TO HAVE THE BEST HANDLE ON THESE BANDS OF
CONVECTION...ALTHOUGH ITS TIMING WAS SLOW BY A FEW HOURS. LEANED
HEAVILY ON THE 05Z HRRR WITH THE APPROPRIATE TIMING ADJUSTMENT FOR
THE EARLY MORNING FORECAST. SHOWERS AND THUNDERSTORMS ARE
REASONABLY HOLDING TOGETHER IN A HIGH SHEAR/LOW CAPE ENVIRONMENT.
LATER TODAY...EXPECTING THE STALLED BACK-DOOR COLD FRONT TO MOVE
BACK NORTH AS A WARM FRONT. THERE ARE STILL SOME QUESTIONS AS TO
HOW FAST THIS WILL HAPPEN. CURRENTLY THINKING THERE IS NOT ENOUGH
PUSH TO DRIVE IT COMPLETELY THROUGH SOUTHERN NEW ENGLAND. AS
SUCH...MAINTAINED COASTAL SEABREEZE FRONTS ALONG BOTH COASTS.
THIS HAS BIG RAMIFICATIONS FOR TEMPERATURES ALONG THE EAST COAST.
SHOULD THIS FRONT GET ENOUGH PUSH...CURRENT FORECAST TEMPERATURES
ARE LIKELY 5-10 DEGREES TOO LOW ALONG THE IMMEDIATE COASTLINE. AM
MORE CONFIDENT WITH TEMPERATURES FARTHER INLAND. SHOULD THERE BE
MORE SUNSHINE THAT CURRENTLY THINKING...LIKELY TOO LOW FARTHER
INLAND AS WELL.
THINKING THERE WILL BE MORE CLOUDS THAN SUNSHINE TODAY OWING TO
LOTS OF CONVECTIVE DEBRIS FROM THE OVERNIGHT SHOWERS...AS WELL AS
NEW CONVECTIVE CLOUDS AS WE HEAD INTO THIS AFTERNOON.
MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED LATER TODAY. THERE IS
THE POSSIBILITY FOR MORE ISOLATED SEVERE WEATHER. THE GREATEST
RISK SHOULD BE FARTHER WEST OF OUR REGION WHERE THE MORE FAVORABLE
COMBINATION OF INSTABILITY AND SHEAR SHOULD BE. THE BEST ADVICE IS
TO KEEP AN EYE ON THE SKY AND LATER FORECASTS IF YOU WILL BE
OUTDOORS THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
TONIGHT...MORE OF THE SAME TONIGHT. WARM FRONT CONTINUES TO PUSH
NORTH AS STRONGER SOUTH TO SOUTHWEST SYNOPTIC FLOW DEVELOPS.
DECENT INSTABILITY PERSISTS THROUGH THE NIGHT. SO THINKING WE WILL
BE SEEING ANOTHER NIGHT OF ISOLATED TO SCATTERED THUNDERSTORMS.
THE GREATEST RISK OF THESE WILL BE ACROSS THE INTERIOR...AWAY FROM
THE STABILIZING INFLUENCE OF THE OCEAN.
THURSDAY...SOUTHERN NEW ENGLAND REMAINS IN THE WARM SECTOR OF A
LOW PRESSURE MOVING FROM THE GREAT LAKES INTO THE SAINT LAWRENCE
RIVER VALLEY. THIS LOW HAS A RATHER AMPLIFIED UPPER SYSTEM...SO
ITS COLD FRONT WILL BE SLOW TO MOVE ACROSS OUR REGION.
EXPECTING MORE ROUNDS OF SHOWERS AND SCATTERED THUNDERSTORMS.
VERY HUMID AIRMASS IN PLACE AS WELL...WITH PRECIPITABLE WATER
VALUES AROUND 1.7 INCHES. WILL LIKELY SEE SOME HEAVY DOWNPOURS
WITH SOME SHOWERS...ALONG WITH SOME HAIL AND GUSTY WINDS. MAY NOT
QUITE REACH SEVERE THRESHOLDS AS CLOUDS WILL BE MORE PREVALENT...
THUS TEMPERATURES SHOULD BE LOWER THAN WEDNESDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
HIGHLIGHTS...
* SCATTERED SHOWERS AND THUNDERSTORMS FRIDAY
* COOLER AND LESS HUMID FOR THE WEEKEND
CONFIDENCE LEVEL/MODEL GUIDANCE...MODERATE CONFIDENCE IN OVERALL
FORECAST. 00Z MODELS CONTINUE TO SLOW DOWN THE ELONGATED TROUGH
MOVING ACROSS THE EASTERN HALF OF THE CONUS. THERE IS STILL SOME
TIMING DIFFERENCES ON WHEN THE SYSTEM WILL PUSH THROUGH THE
NORTHEAST. REGARDLESS APPEARS THAT ELONGATED TROUGH WILL MOVE INTO
NEW ENGLAND EVENTUALLY BECOMING A CUTOFF LOW BY THE WEEKEND. THIS
LOW WILL EVENTUALLY MOVE INTO THE MARITIMES BY THE BEGINNING OF
THE WORK WEEK AS HIGH PRESSURE MOVES IN. HAVE HIGH CONFIDENCE THAT
PRECIP WILL OCCUR ON FRIDAY AND COOLER TEMPS WILL DOMINATE THE
REGION FOR THE WEEKEND. LOW CONFIDENCE IN FORECAST AFTER TUES.
DETAILS...
THURSDAY NIGHT INTO FRIDAY...
UPPER LEVEL TROUGH WILL PUSH THROUGH THE EASTERN GREAT LAKES
REGION EVENTUALLY PUSHING A COLD FRONT THROUGH SOUTHERN NEW
ENGLAND. MODELS CONTINUE TO SLOW THE TIMING OF THE FRONT DOWN...SO
BELIEVE THAT IT MOVE THROUGH SOMETIME ON FRIDAY. BECAUSE OF THE
MODEL DIFFERENCE HAVE LOW CONFIDENCE IN TIMING.
REGARDLESS...BELIEVE THAT SHOWERS AND THUNDERSTORMS WILL MOVE
THROUGH WITH TEMPS NEAR AVG. CANNOT RULE OUT A FEW STRONG
THUNDERSTORMS ESPECIALLY ACROSS REGIONS SOUTH OF THE I-84
CORRIDOR. MODELS INDICATE SOME INSTABILITY WITH ABOUT 25KTS OF
SHEAR. PWAT VALUES OF OVER 1.5 INCHES LEADS FORECASTER TO BELIEVE
THAT HEAVY DOWNPOURS IS THE MAIN THREAT...BUT WITH FALLING HEIGHTS
AS COLD FRONT APPROACHES...SMALL HAIL AND GUSTY WINDS IS NOT OUT
OF THE QUESTION. ANY CHANCE FOR STRONG STORMS TO DEVELOP WILL
DIMINISH AFTER SUNSET AS DIURNAL HEATING IS LOST.
WEEKEND...TRICKY FORECAST IS PLAYING OUT FOR THE WEEKEND. MODELS
HAVE INDICATED THAT THE ELONGATED TROUGH WILL CUT OFF OVER THE MID
ATLANTIC AND SLOWLY ROTATE OVER NEW ENGLAND FOR THE WEEKEND. THIS
WILL ALLOW FOR MUCH COOLER AIR...WELL BELOW AVG AND EVEN HAS
SLOWED DOWN THE TIMING OF PRECIP. BELIEVE THAT PRECIP MAY LINGER
INTO SAT...BUT HAVE LOW CONFIDENCE THAT PRECIP WILL OCCUR ON
SUNDAY. FOR NOW HAVE CONTINUED WITH THE SLOW DOWN TREND IN THE
FORECAST. EXPECT HIGHS REACHING INTO THE MID TO UPPER 60S WITH
LOWS DROPPING INTO THE MID TO UPPER 30S. IF SKIES CLEAR OUT AS
THIS COLD POOL SITS OVER US...THERE IS A POSSIBILITY THAT
FROST/FREEZE HEADLINES MAY BE NEEDED AS THE ENTIRE REGION IS
OFFICIALLY IN THE GROWING SEASON.
MONDAY AND BEYOND...SURFACE HIGH PRESSURE WILL BE IN CONTROL FOR
THE FIRST HALF OF NEXT WEEK. THIS WILL HELP TEMPS REACH SEASONAL
CONDITIONS. APPEARS THAT THERE IS LIMITED MOISTURE KEEPING THE
FORECAST DRY...HOWEVER CANNOT RULE OUT A SPOT SHOWER OR TWO...ESP
IF SEA BREEZES DEVELOPS.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
OVERVIEW...MODERATE CONFIDENCE IN TIMING AND AREAL COVERAGE OF
STRATUS AND FOG THROUGH THIS MORNING.
TODAY...EXPECT MVFR-LIFR CONDITIONS TO GRADUALLY IMPROVE TO VFR
14-16Z AS SW WINDS DEVELOP. IFR MAY PERSIST MOST OF THE DAY AT
KACK. ISOLATED TO SCATTERED CONVECTION BECOMING MORE WIDESPREAD
THIS AFTERNOON...ESPECIALLY WEST OF KMHT-KORH-KIJD.
TONIGHT...MODERATE CONFIDENCE IN TRENDS. EXPECT VARIABLE
CONDITIONS DEPENDING UPON SHOWER AND FOG DEVELOPMENT. BETTER SHOT
FOR IFR VSBYS IN FOG ALONG S COAST ON S-SW WINDS AND MILD TEMPS
MAINLY AFTER MIDNIGHT. SCT SHOWERS/TSTMS ACROSS MOST OF THE REGION
THOUGH BEST SHOT ACROSS CENTRAL AND WESTERN AREAS...WITH MVFR-IFR
CIGS/VSBYS. MAY SEE LOCAL HEAVY DOWNPOURS. LOW CONFIDENCE ON
TIMING AND PLACEMENT.
THURSDAY...MODERATE CONFIDENCE IN TRENDS. VERY UNSETTLED PATTERN
AHEAD OF APPROACHING COLD FRONT. VARIABLE CONDITIONS BETWEEN VFR
AND MVFR/IFR IN SHRA/TSRA/PATCHY FOG. COLD FRONT CROSSES THE
REGION THU NIGHT...SO WILL SEE IMPROVING CONDITIONS ACROSS WESTERN
AREAS AFTER MIDNIGHT THU NIGHT...THEN INTO CENTRAL SECTIONS AFTER
06Z-07Z. MAY SEE SW WIND GUSTING UP TO 20-25 KT DURING THE DAY AS
WELL. WINDS SHIFT TO W-NW ACROSS CENTRAL AND WESTERN AREAS AFTER
MIDNIGHT.
KBOS TERMINAL...MODERATE CONFIDENCE IN TRENDS...LOWER CONFIDENCE
IN TIMING OF LOWER CONDITIONS AND CONVECTION THIS AFTERNOON.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF...MAINLY DUE TO TIMING
OF CONVECTION THIS AFTERNOON. COULD SEE BRIEF IFR IN A BAND OF
TSRA.
OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY...
THURSDAY NIGHT INTO FRIDAY...LOW CONFIDENCE. MODERATE CONFIDENCE
ON SEA BREEZE DEVELOPMENTS. VERY UNSETTLED PATTERN WITH
VARIABILITY BETWEEN VFR CONDITIONS AND MVFR/IFR CONDITIONS IN
SHRA/TSRA/FOG. IMPROVING CONDITIONS LATE FRIDAY NIGHT INTO
SATURDAY MORNING.
SATURDAY-SUNDAY...HIGH CONFIDENCE. VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE THROUGH TONIGHT.
WINDS EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA
THROUGH TODAY. INCREASING SW FLOW WILL RESULT IN SEAS BUILDING
OVER THE SOUTHERN COASTAL WATERS. SMALL CRAFT ADVISORY ISSUED FOR
LATER TODAY INTO THURSDAY FOR COASTAL WATERS WHERE CONFIDENCE IS
HIGHEST. WINDS SHOULD CONTINUE TO INCREASE TONIGHT INTO THURSDAY
AS A LOW PRESSURE MOVES INTO THE GREAT LAKES. AS SUCH COULD SEE
SMALL CRAFT ADVISORY EXPAND INTO MORE OF THE COASTAL WATERS AROUND
CAPE COD DUE TO 25 KT WIND GUSTS. CONFIDENCE IS NOT YET HIGH
ENOUGH TO ISSUE ADVISORIES FOR THOSE WATERS AT THIS TIME.
EXPECT LOW VSBYS IN HEAVY SHOWERS AND PATCHY FOG AT TIMES.
ISOLATED TO SCATTERED THUNDERSTORMS POSSIBLE AS WELL...ESPECIALLY
NEAR SHORE.
OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY...
FRIDAY...MODERATE TO HIGH CONFIDENCE. COLD FRONT WILL BE SLOW TO
CLEAR THE WATERS...SO EXPECT SW WINDS IN PLACE FOR A PORTION OF
THE DAY BEFORE SHIFTING TO W-NW ACROSS THE EASTERN WATERS.
THE WEEKEND...MODERATE CONFIDENCE. SEAS WILL REMAIN ABOVE SCA FOR
MOST OF THE WEEKEND ESP FOR THE OUTER WATERS. GUSTY NW BEHIND THE
FRONT WILL BRING GUSTS CLOSE TO GALE FORCE SAT INTO SAT NIGHT.
EXPECT BOTH SEAS AND WIND TO SLOWLY SUBSIDE THROUGHOUT THE DAY
ON SUNDAY.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON TODAY TO 6 PM EDT THURSDAY FOR
ANZ255-256.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 6 PM EDT
THURSDAY FOR ANZ235-254.
SMALL CRAFT ADVISORY FROM 9 PM THIS EVENING TO 6 PM EDT
THURSDAY FOR ANZ237.
&&
$$
SYNOPSIS...BELK/DUNTEN
NEAR TERM...BELK/DUNTEN
SHORT TERM...BELK
LONG TERM...DUNTEN
AVIATION...BELK/DUNTEN
MARINE...BELK/DUNTEN
AREA FORECAST DISCUSSION
NWS ALBANY NY
627 AM EDT WED MAY 22 2013
.SYNOPSIS...
LOW PRESSURE WILL MOVE FROM THE GREAT LAKES REGION TODAY INTO THE
SAINT LAWRENCE VALLEY THURSDAY. WARM HUMID CONDITIONS WILL PERSIST
INTO THURSDAY WITH SHOWERS AND THUNDERSTORMS. THURSDAY A STRONG
COLD FRONT WILL PUSH SLOWLY THROUGH NEW YORK AND NEW ENGLAND. LOW
PRESSURE WILL FORM ALONG THIS FRONT ON THE COAST FRIDAY...AS MUCH
COLDER AIR POURS INTO THE REGION. FRIDAY NIGHT THE STORM WILL MOVE
OFFSHORE AS HIGH PRESSURE BUILDS INTO THE GREAT LAKES REGION FOR
THE MEMORIAL DAY WEEKEND. IT WILL BRING FAIR WEATHER WITH
UNSEASONABLY COOL TEMPERATURES FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
TSTMS HAVE ENDED AND ONLY SCT -SHRA REMAIN MAINLY OVER S VT AND
BERKSHIRE COUNTY. SOME ISOLD -SHRA ARE ALONG THE S TIER. FOR THE
NEXT SVRL HOURS MOST OF THIS ACTIVITY WILL DIMINISH AND END.
CLOUDS OVER MUCH OF FCA WILL THIN WITH INCRG SUNSHINE FOR A FEW
HRS.
THE HOOSIC RIVER AND SOME SMALL STREAMS IN SOUTHERN VERMONT HAVE
REACHED BANKFUL AND MAY BRIEFLY EXCEED FLOOD THIS MORNING BEFORE
RECEDING. WARNINGS AND ADVISORIES HAVE BEEN ISSUED TO COVER THESE
SITUATIONS.
AT SFC WMFNT IS N OF FCA. IT WILL MOVE TO ST LAWRENCE VLY TO
MICHIGAN LINE...AS WEAK LOW PRESSURE FORMS ALONG AND PROPAGATES UP
IT TODAY. THIS LEAVES FCA IN WARM SECTOR WITH ALOT OF RESIDUAL
LLVL MOISTURE/CLOUDS FM TUES CONVECTION
WITH TD IN 60S...TEMPS REBOUNDING TO 80S...VRBL CLOUDS THE THREAT
OF TSTMS INCREASES THROUGH THE DAY. LOCAL WRF/HRRR WHICH HANDLED
TODAYS EVENT WELL...SHOW A MAINLY CELLULAR AND PULSE RESPONSE
TODAY IN SIMULATED REFL. GFS PRODUCES SFC CAPES ON THE ORDER OF
1000-2000 J/KG THE NAM 2000-4000 J/KG WITH A DEFINE PREFERENCE
FROM THE CAPITAL DISTRICT S & E AND THE MHWK VLY.
NAM AND GFS SHOW H850-700 LAPSE RATES AROUND 6.5 THIS AFTN.
GOING TO HRRR FOR THE LATE AFTN:
POU/ALB/GFL
CAPE 2000/1812/1777
J/KG MAX WIND 33/33/40 EHI OF 1.6/1.5/1.2
STORM SPEED 24/18/18
SRH 175/156/106
MAGLENTA 1.75/2.17/2.44 ALL MAJOR SEVERE
WHICH IS CONSIDERABLY STRONGER LOOKING THAN HRRR REFL. THE NAM
MODEL SOUNDINGS AND WRF MODEL SOUNDINGS ARE CONSIDERABLY LOWER IN
CAPE AROUND 1000-1200 J/KG.
PWATS WILL CONTINUE TO RUN A FEW STANDARD DEVIATIONS ABOVE NORMAL
WITH VALUES OF 1.50-1.8 INCHES.
SOME OTHER CONSIDERATIONS LLVL JET AT H850 HPA IS 25-35KTS...AND
BULK OF IT MAY PASS WEST OF FCA. THERE IS LITTLE ADDITIONAL UPPER
FORCING. SPC HAS OUTLOOKED NY PORTIONS OF FCA AT THIS POINT WILL
NOT TRY TO GET SPECIFIC...WILL GO WITH ENHANCED WORDING TODAY. IF
THERES A PREFERRED AREA IT WOULD MHWK VLY AND S...AND A PREFERRED
TIME OF LATER IN THE AFTN AND EVENING.
CONVECTION WILL CONTINUE INTO THE EVNG HOURS AND DIM OVERNIGHT AS
FCA IS FIRMLY IN WARM SECTION. LOWS AND TD WILL BE IN THE
60S...AND AREAS OF PATCHY FOG POSSIBLE IN THE MORNING.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
THU AND THU NT 500HPA TROF STARTS MOVING E THROUGH GRTLKS AS SFC
LOW ORGANIZES ALONG SEMI-STALLED FRONT FROM FM LK ERIE UP ST
LAWRENCE VLY. THIS SYSTEM PUSHES SLOWLY EAST DRAGGING A CDFNT TO
BTV-SYR LINE THU AFTN...AND THROUGH FCA BY 12UTC FRI. NAM/GFS IN
PRETTY CLOSE AGREEMENT WITH THIS TIMING. WHILE THERE IS INCRG
DYNAMICS WITH APPROACHING JET AND TROF...CAPES 1000-1500 ...CLOUDS
WILL BE WIDESPREAD HOLDING MAX TEMPS TO MID 70S TO AROUND 80. SPC HAS
ONLY PUT AREA IN SEE TEXT ATTM...WITH LOW PROBS DUE TO LIMITED INSTABILITY.
REGARDLESS AREA WILL SEE PERIOD OF -SHRA/TSTMS INCRG THU...TRANSITIONING
TO -SHRA/-RA BEHIND THE CDFNT OVERNIGHT.
BY FRI MORNING CDFNT WILL BE IN I-95 CORRIDOR ALONG THE ATLC
COAST. 500HPA TROF WILL BE MOVING INTO NE USA...AND BOTH MODELS
DEVELOP A MODEST SFC LOW OVER NJ. THE WARMTH OF PAST FEW DAYS
WILL GIVE WAY TO A COOL BREEZY WITH -SHRA FRI. FINALLY SFC LOW
MOVES OFFSHORE FRI NT AS HIGH PRESSURE BUILDS INTO THE GRTLKS.
HWVR THE 500HPA TROF LINGERS AND CUTS OFF OVER NEW ENG SAT.
BETWEEN THESE TWO SYSTEMS A BRISK NW GRADIENT WILL DRIVE SOME
PRETTY COOL AIR INTO THE REGION FOR LATE MAY. WITH 500HPA CUT OFF
LINGERING SKIES MAY ONLY BE PS SAT IN GFS.
TEMPS WILL PROBABLY GO NOWHERE FRI...ONLY COMING OFF MORNING LOWS
A FEW DEG...OR HOLDING STEADY.
THE GFS/NAM ARE PROGRESSIVE WITH SFC LOW DEPARTING THE COAST FRI
NT...WITH ITS 500 HPA TROF CROSSING REGION SAT AND DEPARTING SAT
NT WITH PC SKIES AND A RATHER BRISK WIND GRADIENT.
THE 00UTC ECMWF CUTS OFF THE 500HPA LOW OVER NJ...DEVELOPS A
COASTAL LOW...WHICH LINGERS ALONG THE EAST COAST FOR THE WEEKEND
WITH PERIODS OF RAW CHILLY RAIN.
THE GFS TEMPS WOULD BRING MINS SAT MORNING INTO THE MID 30S TO
MID 40S WITH SOME NEAR 30 AND POTENTIAL FROST/FREEZE ISSUES IN
ADRNDKS. HIGHS SAT WILL ONLY REBOUND EVEN WITH THE STRONG SUN TO
THE 60S. LOWS SAT NIGHT WOULD AGAIN BE IN THE 30S. WINDS WILL
REMAIN BRISK. ECMWF WOULD RESULT IN SLIGHTLY WARMER NIGHT TIME
TEMPS AND COOLER YET DAYTIME TEMPS IN MID 50S TO LOW 60S. HPC
LEANS TWRD A BLEND WITH CHC POPS LINGERING INTO SAT. IT WILL BE A
FALL LIKE MEMORIAL DAY WEEKEND.
WILL LEAN TWRD GFS/HPC BLEND THROUGH SAT.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
THE ECMWF KEEPS THE 500HPA CUTOFF OVER RGN AND SFC LOW NEAR NEW
ENGLAND COAST FOR A RAW CHILLY WEEKEND...FINALLY CLEARING ON
MONDAY. HWVR AT THIS TIME ITS TO BE CONSIDERED AN OUTLIER.
GFS/NAM/HPC PROGRESSIVELY MOVE THIS SYSTEM ALONG. 17 OF 20
MEMBERS OF THE GEFS ENSEMBLE KEEP IT DRY FROM FRI NIGHT ONWARD.
ONLY 3 HAVE ANY QPF. SO THE WORST CASE IN THE GFS IS SOME CLOUDS
FOR SUNDAY MRNG. OVERALL THE SFC HIGH BUILDS INTO THE GRTLKS
SHIFTING SLOWLY EAST TO FCA BY TUES. AT 500 HPA RIDGE BUILDS FROM
GRT PLAINS TO GRTLKS.
PERIOD WILL START OFF PARTLY CLOUDY W/BLO NORMAL TEMPS AND A BREEZE
CONTINUING SUNDAY. SCT FROST AND FREEZE WILL BE POSSIBLE IN THE
HIR TRRN. IN TIME THIS WILL GIVE WAY TO BRILLIANT SUNSHINE MONDAY
AND TUESDAY...LIGHT WINDS AND TEMPS RETURNING TO NORMAL MONDAY AND
ABV BY TUESDAY AND WED.
WILL POPULATE WITH HPC MIDNIGHT SHIFT GUID.
THE GROWING SEASON IS UNDERWAY ACROSS THE MID HUDSON VALLEY...
GREATER CAPITAL DISTRICT...LAKE GEORGE SARATOGA REGION...THE
MOHAWK VALLEY...EASTERN CATSKILLS...TACONICS...BERKSHIRES...BENNINGTON
AND EASTERN WINDHAM COUNTIES VT AND LITCHFIELD COUNTY. IT WILL
START ON MAY 25TH FOR THE SOUTHERN ADIRONDACKS AND WESTERN WINDHAM
COUNTY.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
ACCOUNTING FOR CURRENT SHOWER AND THUNDERSTORM ACTIVITY THAT SHOULD
CONTINUE AT KGFL THROUGH ABOUT 06Z...AT KALB THROUGH ABOUT
07Z-08Z...AND KPSF THROUGH ABOUT 08Z. SOME MVFR AND OCCASIONAL IFR
CONDITIONS IN THE SHOWERS AND THUNDERSTORMS. SOME OTHER ISOLATED
THUNDERSTORMS WELL WEST OF THE AREA COULD APPROACH THE AREA BETWEEN
KALB AND KPOU THROUGH SUNRISE...BUT WITH CONTINUED STABILIZATION OF
THE ATMOSPHERE THE THUNDERSTORMS COULD DISSIPATE BY THEN.
ONCE THE RAIN ENDS EARLY THIS MORNING...THERE COULD BE PERIODS OF
MVFR FOG AND VFR CEILINGS...BUT SCATTERED CLOUDS COULD DEVELOP BELOW
1000 FEET. WILL HAVE TO MONITOR FOR ANY BETTER CLEARING TOWARD
SUNRISE THAT COULD RESULT IN IFR FOG AND/OR CEILINGS BELOW 1000
FEET. FOR NOW NOT INDICATING ANY IFR CONDITIONS AT ANY TAF SITES
THROUGH THE EARLY MORNING HOURS...BUT WILL AMEND IF CONDITIONS AND
TRENDS CHANGE.
VFR CONDITIONS SHOULD PREVAIL THROUGH MOST OF THE DAY AFTER 12Z
UNTIL NEW CONVECTION DEVELOPS LATER IN THE AFTERNOON AND EVENING.
MIXED SIGNALS ABOUT WHERE THE CONCENTRATION OF THUNDERSTORMS WILL BE
LATER TODAY SO PUTTING VCSH IN ALL TAFS AFTER 22Z...BUT MORE
THUNDERSTORM ACTIVITY EXPECTED SCATTERED ACROSS THE REGION LATE
TOMORROW AFTERNOON AND EVENING.
WINDS SHOULD BE LIGHT SOUTH THROUGH SUNRISE...THEN BECOME VARIABLE
AT LESS THAN 10 KT THROUGH THE DAY TOMORROW...MAINLY SOUTH TO
SOUTHWEST. WINDS SHOULD BE LIGHT AGAIN TOMORROW EVENING. WINDS COULD
BE QUITE GUSTY IN THUNDERSTORMS TOMORROW AFTERNOON AND EVENING.
OUTLOOK...
WED...VFR/MVFR. CHC -SHRA/-TSRA ESPECIALLY DURING THE AFTN.
WED NIGHT...VFR/MVFR. AT KGFL AND KALB -SHRA/-TSRA LIKELY. AT KPSF
AND KPOU CHC -SHRA/-TSRA.
THU...MVFR WITH IFR POSSIBLE. -SHRA/-TSRA LIKELY.
THU NIGHT...VFR/MVFR. CHC -SHRA/-TSRA ESPECIALLY IN THE EVNG.
FRI...MAINLY VFR. CHC -TSRA MAINLY IN THE AM.
SAT-SUN...VFR. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS THROUGH FRIDAY. OCCASIONAL SHOWERS AND
THUNDERSTORMS WILL CONTINUE THROUGH THURSDAY NIGHT. SHOWERS WILL
CONTINUE INTO FRIDAY.
RH VALUES WILL INCREASE TO 85 TO 100 PERCENT TONIGHT...AND
THURSDAY NIGHT...AND LOWER TO 45 TO 60 PERCENT THIS AFTERNOON.
WINDS WILL MAINLY LESS THAN 10 MPH THROUGH TONIGHT...BECOMING
SOUTHWEST AROUND 10MPH THURSDAY.
&&
.HYDROLOGY...
PWATS ON THE ORDER OF 1.5 TO 2.0 INCHES NEXT FEW DAYS. WHILE
WIDESPREAD FLOODING IS NOT ANTICIPATED...LOCALLY HEAVY RAINFALL IN
THUNDERSTORMS AND TRAINING COULD RESULT IN SMALL STREAM AND URBAN
FLOODING OVERNIGHT AND AGAIN THIS AFTERNOON. SIGNIFICANT WITHIN
BANK RISES ARE LIKELY IN LARGER RIVERS.
3-HR ZONAL FFG VALUES ARE GENERALLY IN THE 2.5-3.0 INCH RANGE AT
THIS TIME...WHICH ARE HIGH FOR MID TO LATE MAY.
DUE TO THE SCATTERED NATURE OF THE SHOWERS AND THUNDERSTORMS...
BASIN AVERAGE QPF WILL BE HIGHLY VARIABLE THIS WEEK. THE BEST
THREAT FOR SEEING SIGNIFICANT AMOUNTS OF SHOWERS OR THUNDERSTORMS
WILL THIS AFTERNOON INTO THURSDAY NIGHT.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SNYDER
NEAR TERM...SNYDER
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...NAS
FIRE WEATHER...SNYDER
HYDROLOGY...SNYDER
AREA FORECAST DISCUSSION
NWS ALBANY NY
550 AM EDT WED MAY 22 2013
.SYNOPSIS...
LOW PRESSURE WILL MOVE FROM THE GREAT LAKES REGION TODAY INTO THE
SAINT LAWRENCE VALLEY THURSDAY. WARM HUMID CONDITIONS WILL PERSIST
INTO THURSDAY WITH SHOWERS AND THUNDERSTORMS. THURSDAY A STRONG
COLD FRONT WILL PUSH SLOWLY THROUGH NEW YORK AND NEW ENGLAND. LOW
PRESSURE WILL FORM ALONG THIS FRONT ON THE COAST FRIDAY...AS MUCH
COLDER AIR POURS INTO THE REGION. FRIDAY NIGHT THE STORM WILL MOVE
OFFSHORE AS HIGH PRESSURE BUILDS INTO THE GREAT LAKES REGION FOR
THE MEMORIAL DAY WEEKEND. IT WILL BRING FAIR WEATHER WITH
UNSEASONABLY COOL TEMPERATURES FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
TSTMS HAVE ENDED AND ONLY SCT -SHRA REMAIN MAINLY OVER S VT AND
BERKSHIRE COUNTY. SOME ISOLD -SHRA ARE ALONG THE S TIER. FOR THE
NEXT SVRL HOURS MOST OF THIS ACTIVITY WILL DIMINISH AND END.
CLOUDS OVER MUCH OF FCA WILL THIN WITH INCRG SUNSHINE FOR A FEW
HRS.
THE HOOSIC RIVER AND SOME SMALL STREAMS IN SOUTHERN VERMONT HAVE
REACHED BANKFUL AND MAY BRIEFLY EXCEED FLOOD THIS MORNING BEFORE
RECEDING. WARNINGS AND ADVISORIES HAVE BEEN ISSUED TO COVER THESE
SITUATIONS.
AT SFC WMFNT IS N OF FCA. IT WILL MOVE TO ST LAWRENCE VLY TO
MICHIGAN LINE...AS WEAK LOW PRESSURE FORMS ALONG AND PROPAGATES UP
IT TODAY. THIS LEAVES FCA IN WARM SECTOR WITH ALOT OF RESIDUAL
LLVL MOISTURE/CLOUDS FM TUES CONVECTION
WITH TD IN 60S...TEMPS REBOUNDING TO 80S...VRBL CLOUDS THE THREAT
OF TSTMS INCREASES THROUGH THE DAY. LOCAL WRF/HRRR WHICH HANDLED
TODAYS EVENT WELL...SHOW A MAINLY CELLULAR AND PULSE RESPONSE
TODAY IN SIMULATED REFL. GFS PRODUCES SFC CAPES ON THE ORDER OF
1000-2000 J/KG THE NAM 2000-4000 J/KG WITH A DEFINE PREFERENCE
FROM THE CAPITAL DISTRICT S & E AND THE MHWK VLY.
NAM AND GFS SHOW H850-700 LAPSE RATES AROUND 6.5 THIS AFTN.
GOING TO HRRR FOR THE LATE AFTN:
POU/ALB/GFL
CAPE 2000/1812/1777
J/KG MAX WIND 33/33/40 EHI OF 1.6/1.5/1.2
STORM SPEED 24/18/18
SRH 175/156/106
MAGLENTA 1.75/2.17/2.44 ALL MAJOR SEVERE
WHICH IS CONSIDERABLY STRONGER LOOKING THAN HRRR REFL. THE NAM
MODEL SOUNDINGS AND WRF MODEL SOUNDINGS ARE CONSIDERABLY LOWER IN
CAPE AROUND 1000-1200 J/KG.
PWATS WILL CONTINUE TO RUN A FEW STANDARD DEVIATIONS ABOVE NORMAL
WITH VALUES OF 1.50-1.8 INCHES.
SOME OTHER CONSIDERATIONS LLVL JET AT H850 HPA IS 25-35KTS...AND
BULK OF IT MAY PASS WEST OF FCA. THERE IS LITTLE ADDITIONAL UPPER
FORCING. SPC HAS OUTLOOKED NY PORTIONS OF FCA AT THIS POINT WILL
NOT TRY TO GET SPECIFIC...WILL GO WITH ENHANCED WORDING TODAY. IF
THERES A PREFERRED AREA IT WOULD MHWK VLY AND S...AND A PREFERRED
TIME OF LATER IN THE AFTN AND EVENING.
CONVECTION WILL CONTINUE INTO THE EVNG HOURS AND DIM OVERNIGHT AS
FCA IS FIRMLY IN WARM SECTION. LOWS AND TD WILL BE IN THE
60S...AND AREAS OF PATCHY FOG POSSIBLE IN THE MORNING.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
THU AND THU NT 500HPA TROF STARTS MOVING E THROUGH GRTLKS AS SFC
LOW ORGANIZES ALONG SEMI-STALLED FRONT FROM FM LK ERIE UP ST
LAWRENCE VLY. THIS SYSTEM PUSHES SLOWLY EAST DRAGGING A CDFNT TO
BTV-SYR LINE THU AFTN...AND THROUGH FCA BY 12UTC FRI. NAM/GFS IN
PRETTY CLOSE AGREEMENT WITH THIS TIMING. WHILE THERE IS INCRG
DYNAMICS WITH APPROACHING JET AND TROF...CAPES 1000-1500 ...CLOUDS
WILL BE WIDESPREAD HOLDING MAX TEMPS TO MID 70S TO AROUND 80. SPC HAS
ONLY PUT AREA IN SEE TEXT ATTM...WITH LOW PROBS DUE TO LIMITED INSTABILITY.
REGARDLESS AREA WILL SEE PERIOD OF -SHRA/TSTMS INCRG THU...TRANSITIONING
TO -SHRA/-RA BEHIND THE CDFNT OVERNIGHT.
BY FRI MORNING CDFNT WILL BE IN I-95 CORRIDOR ALONG THE ATLC
COAST. 500HPA TROF WILL BE MOVING INTO NE USA...AND BOTH MODELS
DEVELOP A MODEST SFC LOW OVER NJ. THE WARMTH OF PAST FEW DAYS
WILL GIVE WAY TO A COOL BREEZY WITH -SHRA FRI. FINALLY SFC LOW
MOVES OFFSHORE FRI NT AS HIGH PRESSURE BUILDS INTO THE GRTLKS.
HWVR THE 500HPA TROF LINGERS AND CUTS OFF OVER NEW ENG SAT.
BETWEEN THESE TWO SYSTEMS A BRISK NW GRADIENT WILL DRIVE SOME
PRETTY COOL AIR INTO THE REGION FOR LATE MAY. WITH 500HPA CUT OFF
LINGERING SKIES MAY ONLY BE PS SAT IN GFS.
TEMPS WILL PROBABLY GO NOWHERE FRI...ONLY COMING OFF MORNING LOWS
A FEW DEG...OR HOLDING STEADY.
THE GFS/NAM ARE PROGRESSIVE WITH SFC LOW DEPARTING THE COAST FRI
NT...WITH ITS 500 HPA TROF CROSSING REGION SAT AND DEPARTING SAT
NT WITH PC SKIES AND A RATHER BRISK WIND GRADIENT.
THE 00UTC ECMWF CUTS OFF THE 500HPA LOW OVER NJ...DEVELOPS A
COASTAL LOW...WHICH LINGERS ALONG THE EAST COAST FOR THE WEEKEND
WITH PERIODS OF RAW CHILLY RAIN.
THE GFS TEMPS WOULD BRING MINS SAT MORNING INTO THE MID 30S TO
MID 40S WITH SOME NEAR 30 AND POTENTIAL FROST/FREEZE ISSUES IN
ADRNDKS. HIGHS SAT WILL ONLY REBOUND EVEN WITH THE STRONG SUN TO
THE 60S. LOWS SAT NIGHT WOULD AGAIN BE IN THE 30S. WINDS WILL
REMAIN BRISK. ECMWF WOULD RESULT IN SLIGHTLY WARMER NIGHT TIME
TEMPS AND COOLER YET DAYTIME TEMPS IN MID 50S TO LOW 60S. HPC
LEANS TWRD A BLEND WITH CHC POPS LINGERING INTO SAT. IT WILL BE A
FALL LIKE MEMORIAL DAY WEEKEND.
WILL LEAN TWRD GFS/HPC BLEND THROUGH SAT.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
THE ECMWF KEEPS THE 500HPA CUTOFF OVER RGN AND SFC LOW NEAR NEW
ENGLAND COAST FOR A RAW CHILLY WEEKEND...FINALLY CLEARING ON
MONDAY. HWVR AT THIS TIME ITS TO BE CONSIDERED AN OUTLIER.
GFS/NAM/HPC PROGRESSIVELY MOVE THIS SYSTEM ALONG. 17 OF 20
MEMBERS OF THE GEFS ENSEMBLE KEEP IT DRY FROM FRI NIGHT ONWARD.
ONLY 3 HAVE ANY QPF. SO THE WORST CASE IN THE GFS IS SOME CLOUDS
FOR SUNDAY MRNG. OVERALL THE SFC HIGH BUILDS INTO THE GRTLKS
SHIFTING SLOWLY EAST TO FCA BY TUES. AT 500 HPA RIDGE BUILDS FROM
GRT PLAINS TO GRTLKS.
PERIOD WILL START OFF PARTLY CLOUDY W/BLO NORMAL TEMPS AND A BREEZE
CONTINUING SUNDAY. SCT FROST AND FREEZE WILL BE POSSIBLE IN THE
HIR TRRN. IN TIME THIS WILL GIVE WAY TO BRILLIANT SUNSHINE MONDAY
AND TUESDAY...LIGHT WINDS AND TEMPS RETURNING TO NORMAL MONDAY AND
ABV BY TUESDAY AND WED.
WILL POPULATE WITH HPC MIDNIGHT SHIFT GUID.
THE GROWING SEASON IS UNDERWAY ACROSS THE MID HUDSON VALLEY...
GREATER CAPITAL DISTRICT...LAKE GEORGE SARATOGA REGION...THE
MOHAWK VALLEY...EASTERN CATSKILLS...TACONICS...BERKSHIRES...BENNINGTON
AND EASTERN WINDHAM COUNTIES VT AND LITCHFIELD COUNTY. IT WILL
START ON MAY 25TH FOR THE SOUTHERN ADIRONDACKS AND WESTERN WINDHAM
COUNTY.
&&
.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
ACCOUNTING FOR CURRENT SHOWER AND THUNDERSTORM ACTIVITY THAT SHOULD
CONTINUE AT KGFL THROUGH ABOUT 06Z...AT KALB THROUGH ABOUT
07Z-08Z...AND KPSF THROUGH ABOUT 08Z. SOME MVFR AND OCCASIONAL IFR
CONDITIONS IN THE SHOWERS AND THUNDERSTORMS. SOME OTHER ISOLATED
THUNDERSTORMS WELL WEST OF THE AREA COULD APPROACH THE AREA BETWEEN
KALB AND KPOU THROUGH SUNRISE...BUT WITH CONTINUED STABILIZATION OF
THE ATMOSPHERE THE THUNDERSTORMS COULD DISSIPATE BY THEN.
ONCE THE RAIN ENDS EARLY THIS MORNING...THERE COULD BE PERIODS OF
MVFR FOG AND VFR CEILINGS...BUT SCATTERED CLOUDS COULD DEVELOP BELOW
1000 FEET. WILL HAVE TO MONITOR FOR ANY BETTER CLEARING TOWARD
SUNRISE THAT COULD RESULT IN IFR FOG AND/OR CEILINGS BELOW 1000
FEET. FOR NOW NOT INDICATING ANY IFR CONDITIONS AT ANY TAF SITES
THROUGH THE EARLY MORNING HOURS...BUT WILL AMEND IF CONDITIONS AND
TRENDS CHANGE.
VFR CONDITIONS SHOULD PREVAIL THROUGH MOST OF THE DAY AFTER 12Z
UNTIL NEW CONVECTION DEVELOPS LATER IN THE AFTERNOON AND EVENING.
MIXED SIGNALS ABOUT WHERE THE CONCENTRATION OF THUNDERSTORMS WILL BE
LATER TODAY SO PUTTING VCSH IN ALL TAFS AFTER 22Z...BUT MORE
THUNDERSTORM ACTIVITY EXPECTED SCATTERED ACROSS THE REGION LATE
TOMORROW AFTERNOON AND EVENING.
WINDS SHOULD BE LIGHT SOUTH THROUGH SUNRISE...THEN BECOME VARIABLE
AT LESS THAN 10 KT THROUGH THE DAY TOMORROW...MAINLY SOUTH TO
SOUTHWEST. WINDS SHOULD BE LIGHT AGAIN TOMORROW EVENING. WINDS COULD
BE QUITE GUSTY IN THUNDERSTORMS TOMORROW AFTERNOON AND EVENING.
OUTLOOK...
WED...VFR/MVFR. CHC -SHRA/-TSRA ESPECIALLY DURING THE AFTN.
WED NIGHT...VFR/MVFR. AT KGFL AND KALB -SHRA/-TSRA LIKELY. AT KPSF
AND KPOU CHC -SHRA/-TSRA.
THU...MVFR WITH IFR POSSIBLE. -SHRA/-TSRA LIKELY.
THU NIGHT...VFR/MVFR. CHC -SHRA/-TSRA ESPECIALLY IN THE EVNG.
FRI...MAINLY VFR. CHC -TSRA MAINLY IN THE AM.
SAT-SUN...VFR. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS THROUGH FRIDAY. OCCASIONAL SHOWERS AND
THUNDERSTORMS WILL CONTINUE THROUGH THURSDAY NIGHT. SHOWERS WILL
CONTINUE INTO FRIDAY.
RH VALUES WILL INCREASE TO 85 TO 100 PERCENT TONIGHT...AND
THURSDAY NIGHT...AND LOWER TO 45 TO 60 PERCENT THIS AFTERNOON.
WINDS WILL MAINLY LESS THAN 10 MPH THROUGH TONIGHT...BECOMING
SOUTHWEST AROUND 10MPH THURSDAY.
&&
.HYDROLOGY...
PWATS ON THE ORDER OF 1.5 TO 2.0 INCHES NEXT FEW DAYS. WHILE
WIDESPREAD FLOODING IS NOT ANTICIPATED...LOCALLY HEAVY RAINFALL IN
THUNDERSTORMS AND TRAINING COULD RESULT IN SMALL STREAM AND URBAN
FLOODING OVERNIGHT AND AGAIN THIS AFTERNOON. SIGNIFICANT WITHIN
BANK RISES ARE LIKELY IN LARGER RIVERS.
3-HR ZONAL FFG VALUES ARE GENERALLY IN THE 2.5-3.0 INCH RANGE AT
THIS TIME...WHICH ARE HIGH FOR MID TO LATE MAY.
DUE TO THE SCATTERED NATURE OF THE SHOWERS AND THUNDERSTORMS...
BASIN AVERAGE QPF WILL BE HIGHLY VARIABLE THIS WEEK. THE BEST
THREAT FOR SEEING SIGNIFICANT AMOUNTS OF SHOWERS OR THUNDERSTORMS
WILL THIS AFTERNOON INTO THURSDAY NIGHT.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SNYDER
NEAR TERM...SNYDER
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...NAS
FIRE WEATHER...SNYDER
HYDROLOGY...SNYDER
AREA FORECAST DISCUSSION
NWS TAUNTON MA
411 AM EDT WED MAY 22 2013
.SYNOPSIS...
A STALLED FRONT WILL MOVE BACK NORTH AS A WARM FRONT TODAY. WARM
AND HUMID CONDITIONS CONTINUE INTO THURSDAY AND FRIDAY WITH
SHOWERS AND SCATTERED STRONG THUNDERSTORMS POSSIBLE. COOLER AND
LESS HUMID CONDITIONS ARE EXPECTED FOR THIS HOLIDAY WEEKEND AS
HIGH PRESSURE BUILDS ACROSS THE NORTHEAST.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
4 AM UPDATE...
CONTINUING TO MONITOR WAVES OF CONVECTION THIS MORNING. LATEST
RUNS OF THE HRRR APPEAR TO HAVE THE BEST HANDLE ON THESE BANDS OF
CONVECTION...ALTHOUGH ITS TIMING WAS SLOW BY A FEW HOURS. LEANED
HEAVILY ON THE 05Z HRRR WITH THE APPROPRIATE TIMING ADJUSTMENT
FOR THE EARLY MORNING FORECAST. SHOWERS AND THUNDERSTORMS ARE
REASONABLY HOLDING TOGETHER IN A HIGH SHEAR/LOW CAPE ENVIRONMENT.
LATER TODAY...EXPECTING THE STALLED BACK-DOOR COLD FRONT TO MOVE
BACK NORTH AS A WARM FRONT. THERE ARE STILL SOME QUESTIONS AS TO
HOW FAST THIS WILL HAPPEN. CURRENTLY THINKING THERE IS NOT ENOUGH
PUSH TO DRIVE IT COMPLETELY THROUGH SOUTHERN NEW ENGLAND. AS
SUCH...MAINTAINED COASTAL SEABREEZE FRONTS ALONG BOTH COASTS.
THIS HAS BIG RAMIFICATIONS FOR TEMPERATURES ALONG THE EAST COAST.
SHOULD THIS FRONT GET ENOUGH PUSH...CURRENT FORECAST TEMPERATURES
ARE LIKELY 5-10 DEGREES TOO LOW ALONG THE IMMEDIATE COASTLINE. AM
MORE CONFIDENT WITH TEMPERATURES FARTHER INLAND. SHOULD THERE BE
MORE SUNSHINE THAT CURRENTLY THINKING...LIKELY TOO LOW FARTHER
INLAND AS WELL.
THINKING THERE WILL BE MORE CLOUDS THAN SUNSHINE TODAY OWING TO
LOTS OF CONVECTIVE DEBRIS FROM THE OVERNIGHT SHOWERS...AS WELL AS
NEW CONVECTIVE CLOUDS AS WE HEAD INTO THIS AFTERNOON.
MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED LATER TODAY. THERE IS
THE POSSIBILITY FOR MORE ISOLATED SEVERE WEATHER. THE GREATEST
RISK SHOULD BE FARTHER WEST OF OUR REGION WHERE THE MORE FAVORABLE
COMBINATION OF INSTABILITY AND SHEAR SHOULD BE. THE BEST ADVICE IS
TO KEEP AN EYE ON THE SKY AND LATER FORECASTS IF YOU WILL BE
OUTDOORS THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
TONIGHT...MORE OF THE SAME TONIGHT. WARM FRONT CONTINUES TO PUSH
NORTH AS STRONGER SOUTH TO SOUTHWEST SYNOPTIC FLOW DEVELOPS.
DECENT INSTABILITY PERSISTS THROUGH THE NIGHT. SO THINKING WE WILL
BE SEEING ANOTHER NIGHT OF ISOLATED TO SCATTERED THUNDERSTORMS.
THE GREATEST RISK OF THESE WILL BE ACROSS THE INTERIOR...AWAY FROM
THE STABILIZING INFLUENCE OF THE OCEAN.
THURSDAY...SOUTHERN NEW ENGLAND REMAINS IN THE WARM SECTOR OF A
LOW PRESSURE MOVING FROM THE GREAT LAKES INTO THE SAINT LAWRENCE
RIVER VALLEY. THIS LOW HAS A RATHER AMPLIFIED UPPER SYSTEM...SO
ITS COLD FRONT WILL BE SLOW TO MOVE ACROSS OUR REGION.
EXPECTING MORE ROUNDS OF SHOWERS AND SCATTERED THUNDERSTORMS.
VERY HUMID AIRMASS IN PLACE AS WELL...WITH PRECIPITABLE WATER
VALUES AROUND 1.7 INCHES. WILL LIKELY SEE SOME HEAVY DOWNPOURS
WITH SOME SHOWERS...ALONG WITH SOME HAIL AND GUSTY WINDS. MAY NOT
QUITE REACH SEVERE THRESHOLDS AS CLOUDS WILL BE MORE PREVALENT...
THUS TEMPERATURES SHOULD BE LOWER THAN WEDNESDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
HIGHLIGHTS...
* SCATTERED SHOWERS AND THUNDERSTORMS FRIDAY
* COOLER AND LESS HUMID FOR THE WEEKEND
CONFIDENCE LEVEL/MODEL GUIDANCE...MODERATE CONFIDENCE IN OVERALL
FORECAST. 00Z MODELS CONTINUE TO SLOW DOWN THE ELONGATED TROUGH
MOVING ACROSS THE EASTERN HALF OF THE CONUS. THERE IS STILL SOME
TIMING DIFFERENCES ON WHEN THE SYSTEM WILL PUSH THROUGH THE
NORTHEAST. REGARDLESS APPEARS THAT ELONGATED TROUGH WILL MOVE INTO
NEW ENGLAND EVENTUALLY BECOMING A CUTOFF LOW BY THE WEEKEND. THIS
LOW WILL EVENTUALLY MOVE INTO THE MARITIMES BY THE BEGINNING OF
THE WORK WEEK AS HIGH PRESSURE MOVES IN. HAVE HIGH CONFIDENCE THAT
PRECIP WILL OCCUR ON FRIDAY AND COOLER TEMPS WILL DOMINATE THE
REGION FOR THE WEEKEND. LOW CONFIDENCE IN FORECAST AFTER TUES.
DETAILS...
THURSDAY NIGHT INTO FRIDAY...
UPPER LEVEL TROUGH WILL PUSH THROUGH THE EASTERN GREAT LAKES
REGION EVENTUALLY PUSHING A COLD FRONT THROUGH SOUTHERN NEW
ENGLAND. MODELS CONTINUE TO SLOW THE TIMING OF THE FRONT DOWN...SO
BELIEVE THAT IT MOVE THROUGH SOMETIME ON FRIDAY. BECAUSE OF THE
MODEL DIFFERENCE HAVE LOW CONFIDENCE IN TIMING.
REGARDLESS...BELIEVE THAT SHOWERS AND THUNDERSTORMS WILL MOVE
THROUGH WITH TEMPS NEAR AVG. CANNOT RULE OUT A FEW STRONG
THUNDERSTORMS ESPECIALLY ACROSS REGIONS SOUTH OF THE I-84
CORRIDOR. MODELS INDICATE SOME INSTABILITY WITH ABOUT 25KTS OF
SHEAR. PWAT VALUES OF OVER 1.5 INCHES LEADS FORECASTER TO BELIEVE
THAT HEAVY DOWNPOURS IS THE MAIN THREAT...BUT WITH FALLING HEIGHTS
AS COLD FRONT APPROACHES...SMALL HAIL AND GUSTY WINDS IS NOT OUT
OF THE QUESTION. ANY CHANCE FOR STRONG STORMS TO DEVELOP WILL
DIMINISH AFTER SUNSET AS DIURNAL HEATING IS LOST.
WEEKEND...TRICKY FORECAST IS PLAYING OUT FOR THE WEEKEND. MODELS
HAVE INDICATED THAT THE ELONGATED TROUGH WILL CUT OFF OVER THE MID
ATLANTIC AND SLOWLY ROTATE OVER NEW ENGLAND FOR THE WEEKEND. THIS
WILL ALLOW FOR MUCH COOLER AIR...WELL BELOW AVG AND EVEN HAS
SLOWED DOWN THE TIMING OF PRECIP. BELIEVE THAT PRECIP MAY LINGER
INTO SAT...BUT HAVE LOW CONFIDENCE THAT PRECIP WILL OCCUR ON
SUNDAY. FOR NOW HAVE CONTINUED WITH THE SLOW DOWN TREND IN THE
FORECAST. EXPECT HIGHS REACHING INTO THE MID TO UPPER 60S WITH
LOWS DROPPING INTO THE MID TO UPPER 30S. IF SKIES CLEAR OUT AS
THIS COLD POOL SITS OVER US...THERE IS A POSSIBILITY THAT
FROST/FREEZE HEADLINES MAY BE NEEDED AS THE ENTIRE REGION IS
OFFICIALLY IN THE GROWING SEASON.
MONDAY AND BEYOND...SURFACE HIGH PRESSURE WILL BE IN CONTROL FOR
THE FIRST HALF OF NEXT WEEK. THIS WILL HELP TEMPS REACH SEASONAL
CONDITIONS. APPEARS THAT THERE IS LIMITED MOISTURE KEEPING THE
FORECAST DRY...HOWEVER CANNOT RULE OUT A SPOT SHOWER OR TWO...ESP
IF SEA BREEZES DEVELOPS.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
OVERVIEW...MODERATE CONFIDENCE IN TIMING AND AREAL COVERAGE OF
STRATUS AND FOG THROUGH THIS MORNING.
THROUGH 12Z...EXPECTING BANDS OF STRONG ENOUGH CONVECTION TO
AVOID. THESE BANDS OF CONVECTION SHOULD CONTINUE TO WEAKEN AS IT
MOVES EAST. MIXED CONDITIONS THIS MORNING WITH WIDESPREAD IFR
ACROSS THE MA COASTAL PLAIN AND MUCH OF RI AND NORTHERN
CT...IMPROVING TO POCKETS OF MVFR ACROSS THE INTERIOR. EVEN SOME
LOCALIZED VFR POSSIBLE.
TODAY...EXPECT MVFR-LIFR CONDITIONS TO GRADUALLY IMPROVE TO VFR
14-16Z AS SW WINDS DEVELOP. IFR MAY PERSIST MOST OF THE DAY AT
KACK. ISOLATED TO SCATTERED CONVECTION BECOMING MORE WIDESPREAD
THIS AFTERNOON...ESPECIALLY WEST OF KMHT-KORH-KIJD.
TONIGHT...MODERATE CONFIDENCE IN TRENDS. EXPECT VARIABLE
CONDITIONS DEPENDING UPON SHOWER AND FOG DEVELOPMENT. BETTER SHOT
FOR IFR VSBYS IN FOG ALONG S COAST ON S-SW WINDS AND MILD TEMPS
MAINLY AFTER MIDNIGHT. SCT SHOWERS/TSTMS ACROSS MOST OF THE REGION
THOUGH BEST SHOT ACROSS CENTRAL AND WESTERN AREAS...WITH MVFR-IFR
CIGS/VSBYS. MAY SEE LOCAL HEAVY DOWNPOURS. LOW CONFIDENCE ON
TIMING AND PLACEMENT.
THURSDAY...MODERATE CONFIDENCE IN TRENDS. VERY UNSETTLED PATTERN
AHEAD OF APPROACHING COLD FRONT. VARIABLE CONDITIONS BETWEEN VFR
AND MVFR/IFR IN SHRA/TSRA/PATCHY FOG. COLD FRONT CROSSES THE
REGION THU NIGHT...SO WILL SEE IMPROVING CONDITIONS ACROSS WESTERN
AREAS AFTER MIDNIGHT THU NIGHT...THEN INTO CENTRAL SECTIONS AFTER
06Z-07Z. MAY SEE SW WIND GUSTING UP TO 20-25 KT DURING THE DAY AS
WELL. WINDS SHIFT TO W-NW ACROSS CENTRAL AND WESTERN AREAS AFTER
MIDNIGHT.
KBOS TERMINAL...MODERATE CONFIDENCE IN TRENDS...LOWER CONFIDENCE
IN TIMING OF LOWER CONDITIONS AND CONVECTION THIS AFTERNOON.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF...MAINLY DUE TO TIMING
OF CONVECTION THIS AFTERNOON. COULD SEE BRIEF IFR IN A BAND OF
TSRA. APPEARS THIS BAND WILL PASS TO THE NORTH OF THE TERMINAL
THROUGH 0830Z. WILL CONTINUE TO MONITOR.
OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY...
THURSDAY NIGHT INTO FRIDAY...LOW CONFIDENCE. MODERATE CONFIDENCE
ON SEA BREEZE DEVELOPMENTS. VERY UNSETTLED PATTERN WITH
VARIABILITY BETWEEN VFR CONDITIONS AND MVFR/IFR CONDITIONS IN
SHRA/TSRA/FOG. IMPROVING CONDITIONS LATE FRIDAY NIGHT INTO
SATURDAY MORNING.
SATURDAY-SUNDAY...HIGH CONFIDENCE. VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE THROUGH TONIGHT.
WINDS EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA
THROUGH TODAY. INCREASING SW FLOW WILL RESULT IN SEAS BUILDING
OVER THE SOUTHERN COASTAL WATERS. SMALL CRAFT ADVISORY ISSUED FOR
LATER TODAY INTO THURSDAY FOR COASTAL WATERS WHERE CONFIDENCE IS
HIGHEST. WINDS SHOULD CONTINUE TO INCREASE TONIGHT INTO THURSDAY
AS A LOW PRESSURE MOVES INTO THE GREAT LAKES. AS SUCH COULD SEE
SMALL CRAFT ADVISORY EXPAND INTO MORE OF THE COASTAL WATERS AROUND
CAPE COD DUE TO 25 KT WIND GUSTS. CONFIDENCE IS NOT YET HIGH
ENOUGH TO ISSUE ADVISORIES FOR THOSE WATERS AT THIS TIME.
EXPECT LOW VSBYS IN HEAVY SHOWERS AND PATCHY FOG AT TIMES.
ISOLATED TO SCATTERED THUNDERSTORMS POSSIBLE AS WELL...ESPECIALLY
NEAR SHORE.
OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY...
FRIDAY...MODERATE TO HIGH CONFIDENCE. COLD FRONT WILL BE SLOW TO
CLEAR THE WATERS...SO EXPECT SW WINDS IN PLACE FOR A PORTION OF
THE DAY BEFORE SHIFTING TO W-NW ACROSS THE EASTERN WATERS.
THE WEEKEND...MODERATE CONFIDENCE. SEAS WILL REMAIN ABOVE SCA FOR
MOST OF THE WEEKEND ESP FOR THE OUTER WATERS. GUSTY NW BEHIND THE
FRONT WILL BRING GUSTS CLOSE TO GALE FORCE SAT INTO SAT NIGHT.
EXPECT BOTH SEAS AND WIND TO SLOWLY SUBSIDE THROUGHOUT THE DAY
ON SUNDAY.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON TODAY TO 6 PM EDT THURSDAY FOR
ANZ255-256.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 6 PM EDT
THURSDAY FOR ANZ235-254.
SMALL CRAFT ADVISORY FROM 9 PM THIS EVENING TO 6 PM EDT
THURSDAY FOR ANZ237.
&&
$$
SYNOPSIS...BELK/DUNTEN
NEAR TERM...BELK
SHORT TERM...BELK
LONG TERM...DUNTEN
AVIATION...BELK/DUNTEN
MARINE...BELK/DUNTEN
AREA FORECAST DISCUSSION
NWS ALBANY NY
321 AM EDT WED MAY 22 2013
.SYNOPSIS...
LOW PRESSURE WILL MOVE FROM THE GREAT LAKES REGION TODAY INTO THE
SAINT LAWRENCE VALLEY THURSDAY. WARM HUMID CONDITIONS WILL PERSIST
INTO THURSDAY WITH SHOWERS AND THUNDERSTORMS. THURSDAY A STRONG
COLD FRONT WILL PUSH SLOWLY THROUGH NEW YORK AND NEW ENGLAND. LOW
PRESSURE WILL FORM ALONG THIS FRONT ON THE COAST FRIDAY...AS MUCH
COLDER AIR POURS INTO THE REGION. FRIDAY NIGHT THE STORM WILL MOVE
OFFSHORE AS HIGH PRESSURE BUILDS INTO THE GREAT LAKES REGION FOR
THE MEMORIAL DAY WEEKEND. IT WILL BRING FAIR WEATHER WITH
UNSEASONABLY COOL TEMPERATURES FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
LINE OF THUNDERSTORMS EAST OF I-88 CORRIDOR MOVING THROUGH FCA
ATTM. MAINLY HEAVY RAIN AND FREQ LIGHTNING. AREAS OF MODERATE RAIN
EXTEND BEHIND IT.
MOST AREAS TO BE IMPACTED WILL SEE ANOTHER 0.5 TO 1.O INCH OF RAIN
BRINGING TOTALS FOR TODAY UP TO 2-3 INCHES IN MOST AREAS IMPACTED
WITH SOME ISOLD 4 INCH AMOUNTS. AREAL FLOOD ADVISORY HAS BEEN
ISSUED FROM MHWK VLY AND ADJACENT AREAS INTO S VT/BERKSHIRE COUNTY
FOR OVERNIGHT TO COVER ANY SMALL STREAM AND URBAN FLOODING.
THIS LINE SHOULD EXIT MOST OF UPSTATE NY/VT AND W MA NEXT 1.5 TO
2 HRS...EXCEPT CATSKILLS AND MID HUDSON VLY WHERE IT IS JUST
ARRIVING IN AREAS THAT HAVE NOT HAD MUCH PCPN AT ALL OR SINCE
SINCE LATE TUES AFTN. IT SHOULD THEN DIMINISH AND END OVERNIGHT
AT SFC WMFNT IS LIFTING NE THROUGH FCA OVERNIGHT AND WILL BE ALONG
N TIER OR N OF RGN WED MRNG. IT WILL MOVE TO ST LAWRENCE VLY TO
MICHIGAN LINE...AS WEAK LOW PRESSURE FORMS ALONG AND PROPAGATES UP
IT TODAY. THIS LEAVES FCA IN WARM SECTOR WITH ALOT OF RESIDUAL
LLVL MOISTURE/CLOUDS FM TUES CONVECTION
WITH TD IN 60S...TEMPS REBOUNDING TO 80S...VRBL CLOUDS THE THREAT
OF TSTMS INCREASES THROUGH THE DAY. LOCAL WRF/HRRR WHICH HANDLED
TODAYS EVENT WELL...SHOW A MAINLY CELLULAR AND PULSE RESPONSE
TODAY IN SIMULATED REFL. GFS PRODUCES SFC CAPES ON THE ORDER OF
1000-2000 J/KG THE NAM 2000-4000 J/KG WITH A DEFINE PREFERENCE
FROM THE CAPITAL DISTRICT S & E AND THE MHWK VLY.
NAM AND GFS SHOW H850-700 LAPSE RATES AROUND 6.5 THIS AFTN.
GOING TO HRRR FOR THE LATE AFTN:
POU/ALB/GFL
CAPE 2000/1812/1777
J/KG MAX WIND 33/33/40 EHI OF 1.6/1.5/1.2
STORM SPEED 24/18/18
SRH 175/156/106
MAGLENTA 1.75/2.17/2.44 ALL MAJOR SEVERE
WHICH IS CONSIDERABLY STRONGER LOOKING THAN HRRR REFL. THE NAM
MODEL SOUNDINGS AND WRF MODEL SOUNDINGS ARE CONSIDERABLY LOWER IN
CAPE AROUND 1000-1200 J/KG.
PWATS WILL CONTINUE TO RUN A FEW STANDARD DEVIATIONS ABOVE NORMAL
WITH VALUES OF 1.50-1.8 INCHES.
SOME OTHER CONSIDERATIONS LLVL JET AT H850 HPA IS 25-35KTS...AND
BULK OF IT MAY PASS WEST OF FCA. THERE IS LITTLE ADDITIONAL UPPER
FORCING. SPC HAS OUTLOOKED NY PORTIONS OF FCA AT THIS POINT WILL
NOT TRY TO GET SPECIFIC...WILL GO WITH ENHANCED WORDING TODAY. IF
THERES A PREFERRED AREA IT WOULD MHWK VLY AND S...AND A PREFERRED
TIME OF LATER IN THE AFTN AND EVENING.
CONVECTION WILL CONTINUE INTO THE EVNG HOURS AND DIM OVERNIGHT AS
FCA IS FIRMLY IN WARM SECTION. LOWS AND TD WILL BE IN THE
60S...AND AREAS OF PATCHY FOG POSSIBLE IN THE MORNING.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
THU AND THU NT 500HPA TROF STARTS MOVING E THROUGH GRTLKS AS SFC
LOW ORGANIZES ALONG SEMI-STALLED FRONT FROM FM LK ERIE UP ST
LAWRENCE VLY. THIS SYSTEM PUSHES SLOWLY EAST DRAGGING A CDFNT TO
BTV-SYR LINE THU AFTN...AND THROUGH FCA BY 12UTC FRI. NAM/GFS IN
PRETTY CLOSE AGREEMENT WITH THIS TIMING. WHILE THERE IS INCRG
DYNAMICS WITH APPROACHING JET AND TROF...CAPES 1000-1500 ...CLOUDS
WILL BE WIDESPREAD HOLDING MAX TEMPS TO MID 70S TO AROUND 80. SPC HAS
ONLY PUT AREA IN SEE TEXT ATTM...WITH LOW PROBS DUE TO LIMITED INSTABILITY.
REGARDLESS AREA WILL SEE PERIOD OF -SHRA/TSTMS INCRG THU...TRANSITIONING
TO -SHRA/-RA BEHIND THE CDFNT OVERNIGHT.
BY FRI MORNING CDFNT WILL BE IN I-95 CORRIDOR ALONG THE ATLC
COAST. 500HPA TROF WILL BE MOVING INTO NE USA...AND BOTH MODELS
DEVELOP A MODEST SFC LOW OVER NJ. THE WARMTH OF PAST FEW DAYS
WILL GIVE WAY TO A COOL BREEZY WITH -SHRA FRI. FINALLY SFC LOW
MOVES OFFSHORE FRI NT AS HIGH PRESSURE BUILDS INTO THE GRTLKS.
HWVR THE 500HPA TROF LINGERS AND CUTS OFF OVER NEW ENG SAT.
BETWEEN THESE TWO SYSTEMS A BRISK NW GRADIENT WILL DRIVE SOME
PRETTY COOL AIR INTO THE REGION FOR LATE MAY. WITH 500HPA CUT OFF
LINGERING SKIES MAY ONLY BE PS SAT IN GFS.
TEMPS WILL PROBABLY GO NOWHERE FRI...ONLY COMING OFF MORNING LOWS
A FEW DEG...OR HOLDING STEADY.
THE WEEKEND FCST IS DETERIORATING...
THE GFS IS PROGRESSIVE WITH SFC LOW DEPARTING THE COAST FRI
NT...WITH ITS 500 HPA TROF CROSSING REGION SAT AND DEPARTING SAT
NT WITH PC SKIES AND A RATHER BRISK WIND GRADIENT.
THE 00UTC ECMWF CUTS OFF THE 500HPA LOW OVER NJ...DEVELOPS A
COASTAL LOW...WHICH LINGERS ALONG THE EAST COAST FOR THE WEEKEND
WITH PERIODS OF RAW CHILLY RAIN.
THE GFS TEMPS WOULD BRING MINS SAT MORNING INTO THE MID 30S TO
MID 40S WITH SOME NEAR 30 AND POTENTIAL FROST/FREEZE ISSUES IN
ADRNDKS. HIGHS SAT WILL ONLY REBOUND EVEN WITH THE STRONG SUN TO
THE 60S. LOWS SAT NIGHT WOULD AGAIN BE IN THE 30S. WINDS WILL
REMAIN BRISK. ECMWF WOULD RESULT IN SLIGHTLY WARMER NIGHT TIME
TEMPS AND COOLER YET DAYTIME TEMPS IN MID 50S TO LOW 60S. HPC
LEANS TWRD A BLEND WITH CHC POPS LINGERING INTO SAT. IT WILL BE A
FALL LIKE MEMORIAL DAY WEEKEND.
WILL LEAN TWRD GFS/HPC BLEND THROUGH SAT. ATTM WILL MAKE NO
CHANGES BEYOND SAT NT TO MINIMIZE FLIP FLOPPING GIVEN THE SPREAD
IN MODELS SOLUTIONS ATTM.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
CANADIAN HIGH PRESSURE WILL BUILD INTO THE REGION SUNDAY. THE HIGH
WILL SHIFT EASTWARD ACROSS THE REGION AND OFFSHORE EARLY NEXT
WEEK. TEMPERATURES WILL GRADUALLY MODERATE AS THE HIGH SHIFTS TO
THE EAST WITH NEAR SEASONABLE TEMPERATURES FOR MONDAY.
THE GROWING SEASON IS UNDERWAY ACROSS THE MID HUDSON VALLEY...
GREATER CAPITAL DISTRICT...LAKE GEORGE SARATOGA REGION...THE MOHAWK
VALLEY...EASTERN CATSKILLS...TACONICS...BERKSHIRES...BENNINGTON AND
EASTERN WINDHAM COUNTIES VT AND LITCHFIELD COUNTY. IT WILL START ON
MAY 25TH FOR THE SOUTHERN ADIRONDACKS AND WESTERN WINDHAM COUNTY.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
ACCOUNTING FOR CURRENT SHOWER AND THUNDERSTORM ACTIVITY THAT SHOULD
CONTINUE AT KGFL THROUGH ABOUT 06Z...AT KALB THROUGH ABOUT
07Z-08Z...AND KPSF THROUGH ABOUT 08Z. SOME MVFR AND OCCASIONAL IFR
CONDITIONS IN THE SHOWERS AND THUNDERSTORMS. SOME OTHER ISOLATED
THUNDERSTORMS WELL WEST OF THE AREA COULD APPROACH THE AREA BETWEEN
KALB AND KPOU THROUGH SUNRISE...BUT WITH CONTINUED STABILIZATION OF
THE ATMOSPHERE THE THUNDERSTORMS COULD DISSIPATE BY THEN.
ONCE THE RAIN ENDS EARLY THIS MORNING...THERE COULD BE PERIODS OF
MVFR FOG AND VFR CEILINGS...BUT SCATTERED CLOUDS COULD DEVELOP BELOW
1000 FEET. WILL HAVE TO MONITOR FOR ANY BETTER CLEARING TOWARD
SUNRISE THAT COULD RESULT IN IFR FOG AND/OR CEILINGS BELOW 1000
FEET. FOR NOW NOT INDICATING ANY IFR CONDITIONS AT ANY TAF SITES
THROUGH THE EARLY MORNING HOURS...BUT WILL AMEND IF CONDITIONS AND
TRENDS CHANGE.
VFR CONDITIONS SHOULD PREVAIL THROUGH MOST OF THE DAY AFTER 12Z
UNTIL NEW CONVECTION DEVELOPS LATER IN THE AFTERNOON AND EVENING.
MIXED SIGNALS ABOUT WHERE THE CONCENTRATION OF THUNDERSTORMS WILL BE
LATER TODAY SO PUTTING VCSH IN ALL TAFS AFTER 22Z...BUT MORE
THUNDERSTORM ACTIVITY EXPECTED SCATTERED ACROSS THE REGION LATE
TOMORROW AFTERNOON AND EVENING.
WINDS SHOULD BE LIGHT SOUTH THROUGH SUNRISE...THEN BECOME VARIABLE
AT LESS THAN 10 KT THROUGH THE DAY TOMORROW...MAINLY SOUTH TO
SOUTHWEST. WINDS SHOULD BE LIGHT AGAIN TOMORROW EVENING. WINDS COULD
BE QUITE GUSTY IN THUNDERSTORMS TOMORROW AFTERNOON AND EVENING.
OUTLOOK...
WED...VFR/MVFR. CHC -SHRA/-TSRA ESPECIALLY DURING THE AFTN.
WED NIGHT...VFR/MVFR. AT KGFL AND KALB -SHRA/-TSRA LIKELY. AT KPSF
AND KPOU CHC -SHRA/-TSRA.
THU...MVFR WITH IFR POSSIBLE. -SHRA/-TSRA LIKELY.
THU NIGHT...VFR/MVFR. CHC -SHRA/-TSRA ESPECIALLY IN THE EVNG.
FRI...MAINLY VFR. CHC -TSRA MAINLY IN THE AM.
SAT-SUN...VFR. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS THROUGH FRIDAY. OCCASIONAL SHOWERS AND
THUNDERSTORMS WILL CONTINUE THROUGH THURSDAY NIGHT. SHOWERS WILL
CONTINUE INTO FRIDAY.
RH VALUES WILL INCREASE TO 85 TO 100 PERCENT TONIGHT...AND
THURSDAY NIGHT...AND LOWER TO 45 TO 60 PERCENT THIS AFTERNOON.
WINDS WILL MAINLY LESS THAN 10 MPH THROUGH TONIGHT...BECOMING
SOUTHWEST AROUND 10MPH THURSDAY.
&&
.HYDROLOGY...
PWATS ON THE ORDER OF 1.5 TO 2.0 INCHES NEXT FEW DAYS. WHILE
WIDESPREAD FLOODING IS NOT ANTICIPATED...LOCALLY HEAVY RAINFALL IN
THUNDERSTORMS AND TRAINING COULD RESULT IN SMALL STREAM AND URBAN
FLOODING OVERNIGHT AND AGAIN THIS AFTERNOON. SIGNIFICANT WITHIN
BANK RISES ARE LIKELY IN LARGER RIVERS.
3-HR ZONAL FFG VALUES ARE GENERALLY IN THE 2.5-3.0 INCH RANGE AT
THIS TIME...WHICH ARE HIGH FOR MID TO LATE MAY.
DUE TO THE SCATTERED NATURE OF THE SHOWERS AND THUNDERSTORMS...
BASIN AVERAGE QPF WILL BE HIGHLY VARIABLE THIS WEEK. THE BEST
THREAT FOR SEEING SIGNIFICANT AMOUNTS OF SHOWERS OR THUNDERSTORMS
WILL THIS AFTERNOON INTO THURSDAY NIGHT.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SNYDER
NEAR TERM...SNYDER
SHORT TERM...SNYDER
LONG TERM...IAA
AVIATION...NAS
FIRE WEATHER...SNYDER
HYDROLOGY...SNYDER
AREA FORECAST DISCUSSION
NWS TAUNTON MA
241 AM EDT WED MAY 22 2013
.SYNOPSIS...
A STALLED FRONT WILL MOVE BACK NORTH AS A WARM FRONT TODAY. WARM
AND HUMID CONDITIONS CONTINUE INTO THURSDAY AND FRIDAY WITH
SHOWERS AND SCATTERED STRONG THUNDERSTORMS POSSIBLE. COOLER AND
LESS HUMID CONDITIONS ARE EXPECTED FOR THIS HOLIDAY WEEKEND AS
HIGH PRESSURE BUILDS ACROSS THE NORTHEAST.
&&
.NEAR TERM /THROUGH TODAY/...
2 AM UPDATE...
CONTINUING TO MONITOR WAVES OF CONVECTION THIS MORNING. LATEST
RUNS OF THE HRRR APPEAR TO HAVE THE BEST HANDLE ON THESE BANDS OF
CONVECTION...ALTHOUGH ITS TIMING WAS SLOW BY A FEW HOURS. LEANED
HEAVILY ON THE HRRR WITH THE APPROPRIATE TIMING ADJUSTMENT FOR THE
EARLY MORNING FORECAST. SHOWERS AND THUNDERSTORMS ARE REASONABLY
HOLDING TOGETHER IN A HIGH SHEAR/LOW CAPE ENVIRONMENT.
LATER TODAY...EXPECTING THE STALLED BACK-DOOR COLD FRONT TO MOVE
BACK NORTH AS A WARM FRONT. THERE ARE STILL SOME QUESTIONS AS TO
HOW FAST THIS WILL HAPPEN. CURRENTLY THINKING THERE IS NOT ENOUGH
PUSH TO DRIVE IT COMPLETELY THROUGH SOUTHERN NEW ENGLAND. AS
SUCH...MAINTAINED COASTAL SEABREEZE FRONTS ALONG BOTH COASTS.
THIS HAS BIG RAMIFICATIONS FOR TEMPERATURES ALONG THE EAST COAST.
SHOULD THIS FRONT GET ENOUGH PUSH...CURRENT FORECAST TEMPERATURES
ARE LIKELY 5-10 DEGREES TOO LOW ALONG THE IMMEDIATE COASTLINE. AM
MORE CONFIDENT WITH TEMPERATURES FARTHER INLAND. SHOULD THERE BE
MORE SUNSHINE THAT CURRENTLY THINKING...LIKELY TOO LOW FARTHER
INLAND AS WELL.
THINKING THERE WILL BE MORE CLOUDS THAN SUNSHINE TODAY OWING TO
LOTS OF CONVECTIVE DEBRIS FROM THE OVERNIGHT SHOWERS...AS WELL AS
NEW CONVECTIVE CLOUDS AS WE HEAD INTO THIS AFTERNOON.
MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED LATER TODAY. THERE IS
THE POSSIBILITY FOR MORE ISOLATED SEVERE WEATHER. THE GREATEST
RISK SHOULD BE FARTHER WEST OF OUR REGION WHERE THE MORE FAVORABLE
COMBINATION OF INSTABILITY AND SHEAR SHOULD BE. THE BEST ADVICE IS
TO KEEP AN EYE ON THE SKY AND LATER FORECASTS IF YOU WILL BE
OUTDOORS THIS AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM THURSDAY/...
TONIGHT...MORE OF THE SAME TONIGHT. WARM FRONT CONTINUES TO PUSH
NORTH AS STRONGER SOUTH TO SOUTHWEST SYNOPTIC FLOW DEVELOPS.
DECENT INSTABILITY PERSISTS THROUGH THE NIGHT. SO THINKING WE WILL
BE SEEING ANOTHER NIGHT OF ISOLATED TO SCATTERED THUNDERSTORMS.
THE GREATEST RISK OF THESE WILL BE ACROSS THE INTERIOR...AWAY FROM
THE STABILIZING INFLUENCE OF THE OCEAN.
THURSDAY...SOUTHERN NEW ENGLAND REMAINS IN THE WARM SECTOR OF A
LOW PRESSURE MOVING FROM THE GREAT LAKES INTO THE SAINT LAWRENCE
RIVER VALLEY. THIS LOW HAS A RATHER AMPLIFIED UPPER SYSTEM...SO
ITS COLD FRONT WILL BE SLOW TO MOVE ACROSS OUR REGION.
EXPECTING MORE ROUNDS OF SHOWERS AND SCATTERED THUNDERSTORMS.
VERY HUMID AIRMASS IN PLACE AS WELL...WITH PRECIPITABLE WATER
VALUES AROUND 1.7 INCHES. WILL LIKELY SEE SOME HEAVY DOWNPOURS
WITH SOME SHOWERS...ALONG WITH SOME HAIL AND GUSTY WINDS. MAY NOT
QUITE REACH SEVERE THRESHOLDS AS CLOUDS WILL BE MORE PREVALENT...
THUS TEMPERATURES SHOULD BE LOWER THAN WEDNESDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
HIGHLIGHTS...
* SHOWERS AND SCATTERED THUNDERSTORMS THURSDAY INTO FRIDAY
* COOLER AND LESS HUMID FOR THE HOLIDAY WEEKEND INTO EARLY NEXT
WEEK
OVERVIEW AND MODEL PREFERENCES...
MEDIUM RANGE OPERATIONAL MODEL SUITE SIGNALING AN AMPLIFIED...
SLOWLY PROGRESSIVE PATTERN ACROSS THE LOWER 48. AT THE START...
NOTING LONG WAVE TROUGH ACROSS THE UPPER PLAINS INTO THE WESTERN
LAKES THOUGH SOME DIFFERENCES IN POSITIONING...ALONG WITH H5
CUTOFF LOW MOVING INTO THE WEST COAST. LOWER THAN AVERAGE
CONFIDENCE ON THE PROGRESSION OF THE UPPER LEVEL PATTERN
OPERATIONAL SUITE...THOUGH GENERAL SURFACE SYSTEM POSITIONS AND
TIMING SIGNALS THROUGH THE HOLIDAY WEEKEND SEEM FAIRLY GOOD.
BETTER CONTINUITY AMONGST THE MODEL ENSEMBLES...SO LEANED CLOSER
TO THOSE BUT DID INCORPORATE A LITTLE OF THE 12Z GFS/00Z ECMWF
INTO THE EARLY PORTION OF THE LONG TERM /WED NIGHT TO FRI/.
ANTICIPATE SLOW BUT STEADY CHANGE TO THE UPPER PATTERN LATE THIS
WEEK AS UPPER TROUGH MOVES ACROSS THE EASTERN U.S. FRI-SAT. THIS
WILL BRING AIRMASS CHANGE AS UPPER WINDS SHIFT TO NW...BRINGING
COOLER AND DRIER CONDITIONS FOR A GOOD CHUNK OF THE HOLIDAY
WEEKEND. MODERATE TO HIGH CONFIDENCE CONTINUES FOR THE THU-FRI
TIMEFRAME WITH PERIODIC PRECIP AND SCATTERED CONVECTION...THEN
COLD FRONT SHOULD SWEEP THROUGH FRI NIGHT INTO EARLY SAT. MODERATE
CONFIDENCE BEYOND FRIDAY AS MAY SEE SOME TIMING ISSUES WITH THE
PASSAGE OF THE UPPER TROUGH SOMETIME SAT. FEW SHOWERS ARE
POSSIBLE...BUT TIMING IS DIFFICULT. EXPECT HIGH TEMPS THIS WEEKEND
TO RUN UP TO 5 DEGREES BELOW SEASONAL NORMS. DOES LOOK TO BE DRY
INTO EARLY NEXT WEEK WITH CLOSE TO SEASONABLE TEMPS.
DETAILS...
THURSDAY NIGHT...TIMING OF A COLD FRONT IS STILL IN QUESTION.
THOUGH APPEARS IT SHOULD SLOWLY CROSS THE REGION THU NIGHT...MAY
REACH THE COAST BY 12Z FRI. HAVE CARRIED LIKELY TO CAT POPS AS
COLD FRONT PASSES. LOOKS LIKE BEST INSTABILITY MAY PASS E
OVERNIGHT...BUT COULD STILL SEE SOME ELEVATED CONVECTION SO KEPT
SCT THUNDER IN THE FORECAST. TEMPS DO START DROPPING BACK TO THE
LOWER-MID 50S LATE ACROSS FAR INTERIOR AREAS.
FRIDAY...COLD FRONT SHOULD CLEAR THE E COAST DURING THE MORNING
BUT SOME SHOWERS MAY LINGER INTO MID MORNING ACROSS E MA.
OTHERWISE...EXPECT CONDITIONS TO IMPROVE THOUGH IT WILL BE
NOTICEABLY COOLER AND LESS HUMID.
SATURDAY THROUGH TUESDAY...BLOCKING UPPER PATTERN CONTINUES
ACROSS LABRADOR INTO GREENLAND THROUGH THIS TIMEFRAME...WHICH WILL
KEEP HIGH PRES BUILDING OUT OF CENTRAL CANADA DOWN THE EASTERN
SEABOARD. LONG RANGE MODELS AND ENSEMBLES ARE IN PRETTY GOOD
AGREEMENT WITH THIS PORTION OF THE FORECAST. EXPECT DRY AND COOL
CONDITIONS THROUGH THE HOLIDAY WEEKEND INTO EARLY NEXT WEEK. ON
SATURDAY...EXPECT DAYTIME HIGHS ONLY IN THE 60S...RUNNING 4 TO 8
DEGREES BELOW SEASONAL NORMS...THOUGH WILL MODIFY A BIT THROUGH
THE REMAINDER OF THIS TIMEFRAME.
DUE TO SEVERE WEATHER WATCH THIS AFTERNOON...KEPT PREVIOUS FORECAST
GOING FROM SUNDAY ONWARD...BUT LOOKS IN GOOD SHAPE WITH LATEST MODEL
GUIDANCE.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
OVERVIEW...MODERATE CONFIDENCE IN TIMING AND AREAL COVERAGE OF
STRATUS AND FOG THROUGH THIS MORNING.
THROUGH 12Z...EXPECTING BANDS OF STRONG ENOUGH CONVECTION TO
AVOID. THESE BANDS OF CONVECTION SHOULD CONTINUE TO WEAKEN AS IT
MOVES EAST. MIXED CONDITIONS THIS MORNING WITH WIDESPREAD IFR
ACROSS THE MA COASTAL PLAIN AND MUCH OF RI AND NORTHERN
CT...IMPROVING TO POCKETS OF MVFR ACROSS THE INTERIOR. EVEN SOME
LOCALIZED VFR POSSIBLE.
TODAY...EXPECT MVFR-LIFR CONDITIONS TO GRADUALLY IMPROVE TO VFR
14-16Z AS SW WINDS DEVELOP. IFR MAY PERSIST MOST OF THE DAY AT
KACK. ISOLATED TO SCATTERED CONVECTION BECOMING MORE WIDESPREAD
THIS AFTERNOON...ESPECIALLY WEST OF KMHT-KORH-KIJD.
TONIGHT...MODERATE CONFIDENCE IN TRENDS. EXPECT VARIABLE
CONDITIONS DEPENDING UPON SHOWER AND FOG DEVELOPMENT. BETTER SHOT
FOR IFR VSBYS IN FOG ALONG S COAST ON S-SW WINDS AND MILD TEMPS
MAINLY AFTER MIDNIGHT. SCT SHOWERS/TSTMS ACROSS MOST OF THE REGION
THOUGH BEST SHOT ACROSS CENTRAL AND WESTERN AREAS...WITH MVFR-IFR
CIGS/VSBYS. MAY SEE LOCAL HEAVY DOWNPOURS. LOW CONFIDENCE ON
TIMING AND PLACEMENT.
THURSDAY...MODERATE CONFIDENCE IN TRENDS. VERY UNSETTLED PATTERN
AHEAD OF APPROACHING COLD FRONT. VARIABLE CONDITIONS BETWEEN VFR
AND MVFR/IFR IN SHRA/TSRA/PATCHY FOG. COLD FRONT CROSSES THE
REGION THU NIGHT...SO WILL SEE IMPROVING CONDITIONS ACROSS WESTERN
AREAS AFTER MIDNIGHT THU NIGHT...THEN INTO CENTRAL SECTIONS AFTER
06Z-07Z. MAY SEE SW WIND GUSTING UP TO 20-25 KT DURING THE DAY AS
WELL. WINDS SHIFT TO W-NW ACROSS CENTRAL AND WESTERN AREAS AFTER
MIDNIGHT.
KBOS TERMINAL...MODERATE CONFIDENCE IN TRENDS...LOWER CONFIDENCE
IN TIMING OF LOWER CONDITIONS AND CONVECTION THIS AFTERNOON.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF...MAINLY DUE TO TIMING
OF CONVECTION THIS AFTERNOON. COULD SEE BRIEF IFR IN A BAND OF
TSRA. APPEARS THIS BAND WILL PASS TO THE NORTH OF THE TERMINAL
THROUGH 0830Z. WILL CONTINUE TO MONITOR.
OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY...
FRIDAY...MODERATE TO HIGH CONFIDENCE. MAY SEE LEFTOVER POCKETS OF
MVFR CIGS/VSBYS POSSIBLE ACROSS E MA THROUGH 14Z-15Z FRI.
OTHERWISE...VFR.
SATURDAY-SUNDAY...HIGH CONFIDENCE. VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE THROUGH TONIGHT.
WINDS EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA
THROUGH TODAY. INCREASING SW FLOW WILL RESULT IN SEAS BUILDING
OVER THE SOUTHERN COASTAL WATERS. WILL ISSUE A SMALL CRAFT
ADVISORY FOR ROUGH SEAS LATER TODAY INTO THURSDAY. WINDS SHOULD
CONTINUE TO INCREASE TONIGHT INTO THURSDAY AS A LOW PRESSURE MOVES
INTO THE GREAT LAKES.
EXPECT LOW VSBYS IN HEAVY SHOWERS AND PATCHY FOG AT TIMES.
ISOLATED TO SCATTERED THUNDERSTORMS POSSIBLE AS WELL...ESPECIALLY
NEAR SHORE.
OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY...
FRIDAY...MODERATE TO HIGH CONFIDENCE. COLD FRONT WILL BE SLOW TO
CLEAR THE WATERS...SO EXPECT SW WINDS IN PLACE FOR A PORTION OF
THE DAY BEFORE SHIFTING TO W-NW ACROSS THE EASTERN WATERS.
SATURDAY-SUNDAY...MODERATE CONFIDENCE. SEAS WILL REMAIN ABOVE
SMALL CRAFT FOR MOST OF THE WEEKEND ESPECIALLY ON THE OUTER
WATERS. NW GUSTS MAY APPROACH 25 KT.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BELK/EVT
NEAR TERM...BELK
SHORT TERM...BELK
LONG TERM...EVT
AVIATION...BELK/EVT
MARINE...BELK/EVT
AREA FORECAST DISCUSSION
NWS ALBANY NY
156 AM EDT WED MAY 22 2013
.SYNOPSIS...
LOW PRESSURE WILL MOVE FROM THE GREAT LAKES REGION TODAY INTO THE
SAINT LAWRENCE VALLEY THURSDAY. WARM HUMID CONDITIONS WILL PERSIST
INTO THURSDAY WITH SHOWERS AND THUNDERSTORMS. THURSDAY A STRONG
COLD FRONT WILL PUSH SLOWLY THROUGH NEW YORK AND NEW ENGLAND. LOW
PRESSURE WILL FORM ALONG THIS FRONT ON THE COAST FRIDAY...AS MUCH
COLDER AIR POURS INTO THE REGION. FRIDAY NIGHT THE STORM WILL MOVE
OFFSHORE AS HIGH PRESSURE BUILDS INTO THE GREAT LAKES REGION FOR
THE MEMORIAL DAY WEEKEND. IT WILL BRING FAIR WEATHER WITH
UNSEASONABLY COOL TEMPERATURES FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
LINE OF THUNDERSTORMS EAST OF I-88 CORRIDOR MOVING THROUGH FCA
ATTM. MAINLY HEAVY RAIN AND FREQ LIGHTNING. AREAS OF MODERATE RAIN
EXTEND BEHIND IT.
MOST AREAS TO BE IMPACTED WILL SEE ANOTHER 0.5 TO 1.O INCH OF RAIN
BRINGING TOTALS FOR TODAY UP TO 2-3 INCHES IN MOST AREAS IMPACTED
WITH SOME ISOLD 4 INCH AMOUNTS. AREAL FLOOD ADVISORY HAS BEEN
ISSUED FROM MHWK VLY AND ADJACENT AREAS INTO S VT/BERKSHIRE COUNTY
FOR OVERNIGHT TO COVER ANY SMALL STREAM AND URBAN FLOODING.
THIS LINE SHOULD EXIT MOST OF UPSTATE NY/VT AND W MA NEXT 1.5 TO
2 HRS...EXCEPT CATSKILLS AND MID HUDSON VLY WHERE IT IS JUST
ARRIVING IN AREAS THAT HAVE NOT HAD MUCH PCPN AT ALL OR SINCE
SINCE LATE TUES AFTN. IT SHOULD THEN DIMINISH AND END OVERNIGHT
AT SFC WMFNT IS LIFTING NE THROUGH FCA OVERNIGHT AND WILL BE ALONG
N TIER OR N OF RGN WED MRNG. IT WILL MOVE TO ST LAWRENCE VLY TO
MICHIGAN LINE...AS WEAK LOW PRESSURE FORMS ALONG AND PROPAGATES UP
IT TODAY. THIS LEAVES FCA IN WARM SECTOR WITH ALOT OF RESIDUAL
LLVL MOISTURE/CLOUDS FM TUES CONVECTION
WITH TD IN 60S...TEMPS REBOUNDING TO 80S...VRBL CLOUDS THE THREAT
OF TSTMS INCREASES THROUGH THE DAY. LOCAL WRF/HRRR WHICH HANDLED
TODAYS EVENT WELL...SHOW A MAINLY CELLULAR AND PULSE RESPONSE
TODAY IN SIMULATED REFL. GFS PRODUCES SFC CAPES ON THE ORDER OF
1000-2000 J/KG THE NAM 2000-4000 J/KG WITH A DEFINE PREFERENCE
FROM THE CAPITAL DISTRICT S & E AND THE MHWK VLY.
NAM AND GFS SHOW H850-700 LAPSE RATES AROUND 6.5 THIS AFTN.
GOING TO HRRR FOR THE LATE AFTN:
POU/ALB/GFL
CAPE 2000/1812/1777
J/KG MAX WIND 33/33/40 EHI OF 1.6/1.5/1.2
STORM SPEED 24/18/18
SRH 175/156/106
MAGLENTA 1.75/2.17/2.44 ALL MAJOR SEVERE
WHICH IS CONSIDERABLY STRONGER LOOKING THAN HRRR REFL. THE NAM
MODEL SOUNDINGS AND WRF MODEL SOUNDINGS ARE CONSIDERABLY LOWER IN
CAPE AROUND 1000-1200 J/KG.
PWATS WILL CONTINUE TO RUN A FEW STANDARD DEVIATIONS ABOVE NORMAL
WITH VALUES OF 1.50-1.8 INCHES.
SOME OTHER CONSIDERATIONS LLVL JET AT H850 HPA IS 25-35KTS...AND
BULK OF IT MAY PASS WEST OF FCA. THERE IS LITTLE ADDITIONAL UPPER
FORCING. SPC HAS OUTLOOKED NY PORTIONS OF FCA AT THIS POINT WILL
NOT TRY TO GET SPECIFIC...WILL GO WITH ENHANCED WORDING TODAY. IF
THERES A PREFERRED AREA IT WOULD MHWK VLY AND S...AND A PREFERRED
TIME OF LATER IN THE AFTN AND EVENING.
CONVECTION WILL CONTINUE INTO THE EVNG HOURS AND DIM OVERNIGHT AS
FCA IS FIRMLY IN WARM SECTION. LOWS AND TD WILL BE IN THE
60S...AND AREAS OF PATCHY FOG POSSIBLE IN THE MORNING.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
THU-THU NIGHT...TRICKY FORECAST FOR STRONG TO SEVERE CONVECTION
ON THU WITH THE COLD FRONT STILL TO THE WEST. THE BETTER JET
DYNAMICS DURING THE AFTERNOON WITH APPRECIABLE MOISTURE AND
INSTABILITY IN PLACE. THE QUESTION WILL BE HOW MUCH HEATING OCCURS
WITH CLOUD COVER BEING AND ISSUE. LOCATIONS FROM THE CAPITAL
DISTRICT SOUTH AND EAST MAY HAVE THE BEST CHC FOR DESTABILIZATION
AND SEVERE WEATHER. NO SPC OUTLOOK YET...BUT DEFINITELY COULD SEE
ONE LATER FOR PARTS OF THE REGION. WILL MENTION SOME STRONG TO
SEVERE THUNDERSTORMS MAY BE POSSIBLE AGAIN ON THU. THE FRONT MOVES
THROUGH SLOWLY...WITH SHOWERS PERSISTING THROUGH THE OVERNIGHT. A
WEAK WAVE MOVE ALONG THE BOUNDARY TOO. THE COLD ADVECTION WILL
SLOWLY SEEP INTO THE REGION WITH LOWS IN THE 50S TO L60S BY
DAYBREAK FRI. HIGHS WILL GENERALLY BE IN THE 70S ON THU.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
COOLER AND DRY WEATHER EXPECTED FOR THE HOLIDAY WEEKEND. HAVE
FOLLOWED THE WEATHER PREDICTION CENTER`S GUIDANCE WHICH FAVORS THE
ECMWF ENSEMBLE MEAN WHICH HAS THE SUPPORT OF THE GEFS MEANS. WPC
INDICATES THE DETERMINISTIC/OPERATIONAL RUNS OF THE ECMWF AND GFS
DEVIATE SIGNIFICANTLY ENOUGH FROM THE STEADIER MEANS THAT THEY WERE
NOT INCORPORATION INTO THEIR FORECAST.
CANADIAN HIGH PRESSURE WILL BUILD INTO THE REGION AS WE HEAD INTO
THE WEEKEND BEHIND THE DEPARTING LOW PRESSURE SYSTEM. WILL HAVE
LINGER SHOWERS ON FRIDAY AS THE LOW PRESSURE SYSTEM MOVES OFF THE
EAST. ON SATURDAY...THE REGION WILL BE UNDER CYCLONIC FLOW. THE
HIGH WILL SHIFT EASTWARD ACROSS THE REGION AND OFFSHORE EARLY NEXT
WEEK. SATURDAY IS EXPECTED TO BE THE COOLEST DAY WITH HIGHS MAINLY
IN THE MID 50S TO MID 60S...AROUND 10 DEGREE BELOW NORMAL.
TEMPERATURES WILL GRADUALLY MODERATE AS THE HIGH SHIFTS TO THE EAST
WITH NEAR SEASONABLE TEMPERATURES FOR MONDAY.
THE GROWING SEASON IS UNDERWAY ACROSS THE MID HUDSON VALLEY...
GREATER CAPITAL DISTRICT...LAKE GEORGE SARATOGA REGION...THE MOHAWK
VALLEY...EASTERN CATSKILLS...TACONICS...BERKSHIRES...BENNINGTON AND
EASTERN WINDHAM COUNTIES VT AND LITCHFIELD COUNTY. IT WILL START ON
MAY 25TH FOR THE SOUTHERN ADIRONDACKS AND WESTERN WINDHAM COUNTY.
AT THIS TIME...NIGHTTIME LOWS FRIDAY NIGHT/SATURDAY MORNING AND
SATURDAY NIGHT/SUNDAY MORNING ARE EXPECTED TO BE IN THE 40S IN THE
VALLEYS AND 30S ACROSS THE HIGHER TERRAIN. WITH THE EXPANSION OF
THE GROWING SEASON BY THIS TIME FROST ADVISORIES WOULD BE LIKELY
NEEDED FOR THE HIGHER TERRAIN. TEMPERATURES ACROSS THE SOUTHERN
ADIRONDACKS COULD BE COLDER WHICH WOULD LEAD TO THE NEED FOR A
FREEZE WARNING.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
ACCOUNTING FOR CURRENT SHOWER AND THUNDERSTORM ACTIVITY THAT SHOULD
CONTINUE AT KGFL THROUGH ABOUT 06Z...AT KALB THROUGH ABOUT
07Z-08Z...AND KPSF THROUGH ABOUT 08Z. SOME MVFR AND OCCASIONAL IFR
CONDITIONS IN THE SHOWERS AND THUNDERSTORMS. SOME OTHER ISOLATED
THUNDERSTORMS WELL WEST OF THE AREA COULD APPROACH THE AREA BETWEEN
KALB AND KPOU THROUGH SUNRISE...BUT WITH CONTINUED STABILIZATION OF
THE ATMOSPHERE THE THUNDERSTORMS COULD DISSIPATE BY THEN.
ONCE THE RAIN ENDS EARLY THIS MORNING...THERE COULD BE PERIODS OF
MVFR FOG AND VFR CEILINGS...BUT SCATTERED CLOUDS COULD DEVELOP BELOW
1000 FEET. WILL HAVE TO MONITOR FOR ANY BETTER CLEARING TOWARD
SUNRISE THAT COULD RESULT IN IFR FOG AND/OR CEILINGS BELOW 1000
FEET. FOR NOW NOT INDICATING ANY IFR CONDITIONS AT ANY TAF SITES
THROUGH THE EARLY MORNING HOURS...BUT WILL AMEND IF CONDITIONS AND
TRENDS CHANGE.
VFR CONDITIONS SHOULD PREVAIL THROUGH MOST OF THE DAY AFTER 12Z
UNTIL NEW CONVECTION DEVELOPS LATER IN THE AFTERNOON AND EVENING.
MIXED SIGNALS ABOUT WHERE THE CONCENTRATION OF THUNDERSTORMS WILL BE
LATER TODAY SO PUTTING VCSH IN ALL TAFS AFTER 22Z...BUT MORE
THUNDERSTORM ACTIVITY EXPECTED SCATTERED ACROSS THE REGION LATE
TOMORROW AFTERNOON AND EVENING.
WINDS SHOULD BE LIGHT SOUTH THROUGH SUNRISE...THEN BECOME VARIABLE
AT LESS THAN 10 KT THROUGH THE DAY TOMORROW...MAINLY SOUTH TO
SOUTHWEST. WINDS SHOULD BE LIGHT AGAIN TOMORROW EVENING. WINDS COULD
BE QUITE GUSTY IN THUNDERSTORMS TOMORROW AFTERNOON AND EVENING.
OUTLOOK...
WED...VFR/MVFR. CHC -SHRA/-TSRA ESPECIALLY DURING THE AFTN.
WED NIGHT...VFR/MVFR. AT KGFL AND KALB -SHRA/-TSRA LIKELY. AT KPSF
AND KPOU CHC -SHRA/-TSRA.
THU...MVFR WITH IFR POSSIBLE. -SHRA/-TSRA LIKELY.
THU NIGHT...VFR/MVFR. CHC -SHRA/-TSRA ESPECIALLY IN THE EVNG.
FRI...MAINLY VFR. CHC -TSRA MAINLY IN THE AM.
SAT-SUN...VFR. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS THROUGH FRIDAY. OCCASIONAL SHOWERS AND
THUNDERSTORMS WILL CONTINUE THROUGH THURSDAY NIGHT. SHOWERS WILL
CONTINUE INTO FRIDAY.
RH VALUES WILL INCREASE TO 85 TO 100 PERCENT TONIGHT...AND
THURSDAY NIGHT...AND LOWER TO 45 TO 60 PERCENT THIS AFTERNOON.
WINDS WILL MAINLY LESS THAN 10 MPH THROUGH TONIGHT...BECOMING
SOUTHWEST AROUND 10MPH THURSDAY.
&&
.HYDROLOGY...
PWATS ON THE ORDER OF 1.5 TO 2.0 INCHES NEXT FEW DAYS. WHILE
WIDESPREAD FLOODING IS NOT ANTICIPATED...LOCALLY HEAVY RAINFALL IN
THUNDERSTORMS AND TRAINING COULD RESULT IN SMALL STREAM AND URBAN
FLOODING OVERNIGHT AND AGAIN THIS AFTERNOON. SIGNIFICANT WITHIN
BANK RISES ARE LIKELY IN LARGER RIVERS.
3-HR ZONAL FFG VALUES ARE GENERALLY IN THE 2.5-3.0 INCH RANGE AT
THIS TIME...WHICH ARE HIGH FOR MID TO LATE MAY.
DUE TO THE SCATTERED NATURE OF THE SHOWERS AND THUNDERSTORMS...
BASIN AVERAGE QPF WILL BE HIGHLY VARIABLE THIS WEEK. THE BEST
THREAT FOR SEEING SIGNIFICANT AMOUNTS OF SHOWERS OR THUNDERSTORMS
WILL THIS AFTERNOON INTO THURSDAY NIGHT.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SNYDER
NEAR TERM...SNYDER
SHORT TERM...SNYDER
LONG TERM...IAA/NAS
AVIATION...NAS
FIRE WEATHER...SNYDER
HYDROLOGY...SNYDER
AREA FORECAST DISCUSSION
NWS NEW YORK NY
146 AM EDT WED MAY 22 2013
.SYNOPSIS...
A FRONTAL BOUNDARY WILL MOVE INTO THE AREA OVERNIGHT...THEN
DISSIPATE WEDNESDAY MORNING. A COLD FRONT WILL THEN SLOWLY
APPROACH FROM THE WEST...THEN PASS THROUGH THURSDAY NIGHT INTO
FRIDAY MORNING. CANADIAN HIGH PRESSURE WILL THEN BUILD IN FOR THE
MEMORIAL DAY WEEKEND AND EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
HAVE UPDATED GRIDS TO REFLECT CURRENT OBSERVATION TRENDS.
ADVECTION FOG/STRATUS EXPANDING INTO ERN-MOST LONG ISLAND SOUND
AND NEARBY LAND AREAS. WILL CONTINUE WITH DENSE FOG ADVY FOR THE
FORKS OF LONG ISLAND AND COASTAL SE CT...WITH PATCHY FOG
ELSEWHERE.
WATCHING LINE OF CONVECTION OVER CENTRAL NY STATE...WHICH THE RA
AND HRRR SUGGEST COULD MAKE A RIGHT TURN TOWARD THE CWA OVERNIGHT
INTO EARLY WED MORNING. CONVECTION APPEARS OUTFLOW-DOMINATED
WHICH SUGGESTS EVENTUAL WEAKENING. HOWEVER...SINCE THAT OUTFLOW IS
SOMEWHAT ALIGNED WITH THE BULK 0-3 KM SHEAR...SOME REDEVELOPMENT
COULD OCCUR CLOSER TO THE HUDSON VALLEY AND INTERIOR SW CT LATE
TONIGHT...SO HAVE CARRIED A SLIGHT CHANCE POP FOR ALL AREAS LATE
TONIGHT INTO WED MORNING.
BACK DOOR FRONT ADVANCING WWD INTO SOUTHERN CT AND EASTERN LONG
ISLAND WILL LEAD TO A COOLER NIGHT THAN ORIGINALLY FORECAST...WITH
LOWER 55-60. IT WILL HOWEVER REMAIN WARM AND MUGGY OVER THE
HUDSON VALLEY...NYC METRO AND LONG ISLAND...WITH LOWS IN THE 60S.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
LOOKS LIKE A SIMILAR DAY ON WEDNESDAY AS RIDGE SLOWLY SHIFTS
EAST. BACK DOOR COLD FRONT SHOULD QUICKLY WASH OUT WITH DAYTIME
HEATING...AND MORNING FOG AND STRATUS WILL GIVE WAY TO AT LEAST
PARTIAL SUNSHINE. CONVECTION SHOULD BE SCATTERED AT BEST WITH ONLY
MARGINAL INSTABILITY IN PLACE...LESS THAN TODAY. HIGHS IN THE MID
80S...EXCEPT ALONG THE COAST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THE UPPER TROUGH OVER THE MID SECTION OF THE COUNTRY TRANSLATES
EAST THROUGH THE END OF THE WEEK AND THEN OFFSHORE BY THE WEEKEND.
INTERACTION WITH SHORT WAVE ENERGY IN THE NORTHERN BRANCH OF THE
POLAR JET ACROSS EASTERN CANADA WILL AMPLIFY THE TROUGH ACROSS THE
OH VALLEY AND MID ATLANTIC STATES. THIS AMPLIFICATION RESULTS IN
TIMING ISSUES AMONGST THE GLOBAL MODELS...WITH THE OPERATIONAL 12Z
GFS THE SLOWEST AT THE WESTERN END OF THE ENVELOPE. THE ECMWF AND
GGEM ARE THE QUICKEST WITH SWINGING THE FRONT ACROSS THE COAST BY
FRI MORNING. IN FACT...THE GFS CONTINUES TO BECOME MUCH SLOWER
THAN ALL THE GUIDANCE FRI INTO SAT AS THE UPPER LOW CLOSES OFF
APPROACHING THE MID ATLANTIC STATES...TAKING ON A NEGATIVE TILT
MUCH CLOSER TO THE COAST. THIS WOULD RESULT IN A PROLONGED PERIOD
OF POST-FRONTAL RAIN INTO SAT. PREFERENCE AT THIS TIME WAS TO LEAN
TOWARD THE FASTER MODEL CONSENSUS WITH PCPN SHUTTING DOWN FRI
AFT. SUBSEQUENT MODEL TRENDS WILL NEED TO BE CLOSELY MONITORED TO
SEE IF THE FRONTAL SYSTEM SLOWS DOWN EVEN FURTHER.
AS FOR THE SENSIBLE WEATHER...COLD FRONT APPROACHES FROM THE WEST
THU...PASSING ACROSS THE REGION THU NIGHT INTO FRI. HIGH PW
VALUES AND MODERATE INSTABILITY WILL LEAD TO THE DEVELOPMENT OF
WIDESPREAD SHOWERS AND THUNDERSTORMS THAT WORK WEST TO EAST
DURING THIS TIME. THE ISOLATED SEVERE THREAT APPEARS LOW AT THIS
TIME WITH THE LOW-LEVEL JET DISPLACED EAST OF THE AREA AND
MARGINAL DEEP LAYER SHEAR. UNIDIRECTIONAL WIND PROFILES SUPPORT
SOME BOWING LINE SEGMENTS WITH GUSTY WINDS. WET-BULB ZERO VALUES ARE
WARM...SUPPORTING ONLY SMALL HAIL. THE MAIN THREAT LOOKS TO BE
THE POTENTIAL FOR HEAVY RAINFALL...ESPECIALLY IF THE UPPER FLOW
BACKS FURTHER WITH THE AMPLIFICATION OF THE UPPER TROF TO THE
WEST. AVERAGE BASIN RAINFALL SHOULD BE CLOSE TO AN INCH...WITH
LOCALIZED HIGHER AMOUNTS.
A DRIER NW FLOW SET UPS FRI NIGHT WITH STRONG COLD ADVECTION. HIGH
PRESSURE BUILDS ACROSS THE GREAT LAKES AND INTO THE MID ATLANTIC
STATES THROUGH EARLY NEXT WEEK WITH TEMPERATURES SEVERAL DEGREES
BELOW SEASONABLE LEVELS.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
LITTLE CHANGE TO THE AVIATION FORECAST AS A NEARLY STATIONARY
FRONT WILL REMAIN NORTH ACROSS THE LOWER HUDSON VALLEY WHILE
FARTHER EAST THE FRONT WAS MOVING WESTWARD AS A COLD FRONT. THE
FRONT WILL MAKE IT TO AROUND NEW YORK CITY BY MORNING BEFORE
MOVING BACK NORTH DURING THE MORNING.
STRATUS AND FOG HAS BEGUN TO MOVE IN FROM THE EAST AND WILL MOVE
INTO THE NYC AREA TERMINALS FROM 08Z TO 10Z. CEILINGS AND
VISIBILITIES BECOME IFR AND AS LOW AS VLIFR AT THE COASTAL
TERMINALS ESPECIALLY AFTER 07Z. CONDITIONS IMPROVE EARLY WEDNESDAY
MORNING...13Z TO 15Z. TIMING OF IMPROVEMENT AND CONDITIONS
UNCERTAIN. WIND WILL BE LIGHT FROM THE SOUTH THROUGH THE NIGHT
THEN INCREASE TO 10 TO 15 KT DURING WEDNESDAY.
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AFTER 16Z MAINLY NORTH
AND WEST OF THE NEW YORK TERMINALS.
.OUTLOOK FOR 06Z THURSDAY THROUGH SUNDAY...
.WEDNESDAY NIGHT...SCT SHRA AND TSTMS POSSIBLE. IFR POSSIBLE IN FOG
AND STRATUS.
.THURSDAY-FRIDAY...NUMEROUS SHRA AND TSTMS POSSIBLE. IFR POSSIBLE IN
FOG AND STRATUS.
.SATURDAY...RESIDUAL SHRA BEHIND A COLD FRONT WITH MVFR. BECOMING VFR
WITH NW WINDS INCREASING TO 20-30KT.
.SUNDAY...VFR WITH NW WINDS 20-25KT.
&&
.MARINE...
DENSE FOG BEGINNING TO DEVELOP ACROSS THE EASTERN WATERS.
THIS ADVECTION FOG IS EXPECTED TO EXPAND BACK WEST OVERNIGHT.
SHALLOW BACK DOOR COLD FRONT SHOULD BRING SE-E WINDS OVERNIGHT TO
THE ERN-MOST OCEAN WATERS...ALSO LONG ISLAND SOUND AND THE BAYS OF
LONG ISLAND. OTHERWISE...S-SW SUB SCA WINDS SHOULD CONTINUE
THROUGH WED NIGHT. SEAS SHOULD SLOWLY BUILD ON WED...BUT HAVE
UNDERCUT WAVEWATCH TO PREVENT REACHING SCA CRITERIA UNTIL
WEDNESDAY NIGHT. THINKING WITH STRONG INVERSION THAT WIND FORCING
WAS OVERDONE IN THE WW3 FORECAST.
A COLD FRONT WILL MOVE ACROSS THE AREA WATERS FRIDAY MORNING...WITH
HIGH PRESSURE BUILDING THROUGH THE WEEKEND. WINDS COULD BE BELOW
SCA LEVELS BY FRIDAY MORNING...WITH SEAS ON THE OCEAN REMAINING
ABOVE SCA CRITERIA THROUGH MUCH SATURDAY MORNING. UNDERCUT
WAVEWATCH BY A FOOT DURING THIS TIME AS IT WAS SLOWER BRINGING THE
FRONTAL SYSTEM ACROSS THE AREA. THERE IS THOUGH SOME UNCERTAINTY
WITH THE SEAS DUE TO THE TIMING DIFFERENCES AMONGST THE MODELS.
&&
.HYDROLOGY...
SLIGHT CHANCE FOR SOME SHOWERS/TSTMS TO ENTER THE AREA LATE
TONIGHT INTO EARLY WED MORNING. SCT SHOWERS/TSTMS LATER WED WILL
BE CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL...WITH THE BEST
CHANCES NORTH/WEST OF NYC. TOTAL BASIN AVG QPF FOR WED-THU COULD
BE 1/4 TO 1/2 INCH...WITH LOCALLY HIGHER AMTS IN TSTMS.
A MORE ORGANIZED EVENT LATE THU INTO FRI SHOULD PRODUCE AVERAGE
BASIN RAINFALL AMOUNTS CLOSE TO AN INCH...WITH LOCALIZED HIGHER
AMOUNTS. THERE IS THE POTENTIAL FOR TRAINING OF THUNDERSTORMS
WHICH COULD RESULT IN FLASH FLOODING.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR CTZ011-012.
NY...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR NYZ079-081.
NJ...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR ANZ330-340-
345-350-353.
&&
$$
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1232 AM EDT WED MAY 22 2013
.SYNOPSIS...
A FRONTAL BOUNDARY WILL MOVE INTO THE AREA OVERNIGHT...THEN
DISSIPATE WEDNESDAY MORNING. A COLD FRONT WILL THEN SLOWLY
APPROACH FROM THE WEST...THEN PASS THROUGH THURSDAY NIGHT INTO
FRIDAY MORNING. CANADIAN HIGH PRESSURE WILL THEN BUILD IN FOR THE
MEMORIAL DAY WEEKEND AND EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
HAVE UPDATED GRIDS TO REFLECT CURRENT OBSERVATION TRENDS.
ADVECTION FOG/STRATUS EXPANDING INTO ERN-MOST LONG ISLAND SOUND
AND NEARBY LAND AREAS. WILL CONTINUE WITH DENSE FOG ADVY FOR THE
FORKS OF LONG ISLAND AND COASTAL SE CT...WITH PATCHY FOG
ELSEWHERE.
WATCHING LINE OF CONVECTION OVER CENTRAL NY STATE...WHICH THE RA
AND HRRR SUGGEST COULD MAKE A RIGHT TURN TOWARD THE CWA OVERNIGHT
INTO EARLY WED MORNING. CONVECTION APPEARS OUTFLOW-DOMINATED
WHICH SUGGESTS EVENTUAL WEAKENING. HOWEVER...SINCE THAT OUTFLOW IS
SOMEWHAT ALIGNED WITH THE BULK 0-3 KM SHEAR...SOME REDEVELOPMENT
COULD OCCUR CLOSER TO THE HUDSON VALLEY AND INTERIOR SW CT LATE
TONIGHT...SO HAVE CARRIED A SLIGHT CHANCE POP FOR ALL AREAS LATE
TONIGHT INTO WED MORNING.
BACK DOOR FRONT ADVANCING WWD INTO SOUTHERN CT AND EASTERN LONG
ISLAND WILL LEAD TO A COOLER NIGHT THAN ORIGINALLY FORECAST...WITH
LOWER 55-60. IT WILL HOWEVER REMAIN WARM AND MUGGY OVER THE
HUDSON VALLEY...NYC METRO AND LONG ISLAND...WITH LOWS IN THE 60S.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
LOOKS LIKE A SIMILAR DAY ON WEDNESDAY AS RIDGE SLOWLY SHIFTS
EAST. BACK DOOR COLD FRONT SHOULD QUICKLY WASH OUT WITH DAYTIME
HEATING...AND MORNING FOG AND STRATUS WILL GIVE WAY TO AT LEAST
PARTIAL SUNSHINE. CONVECTION SHOULD BE SCATTERED AT BEST WITH ONLY
MARGINAL INSTABILITY IN PLACE...LESS THAN TODAY. HIGHS IN THE MID
80S...EXCEPT ALONG THE COAST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THE UPPER TROUGH OVER THE MID SECTION OF THE COUNTRY TRANSLATES
EAST THROUGH THE END OF THE WEEK AND THEN OFFSHORE BY THE WEEKEND.
INTERACTION WITH SHORT WAVE ENERGY IN THE NORTHERN BRANCH OF THE
POLAR JET ACROSS EASTERN CANADA WILL AMPLIFY THE TROUGH ACROSS THE
OH VALLEY AND MID ATLANTIC STATES. THIS AMPLIFICATION RESULTS IN
TIMING ISSUES AMONGST THE GLOBAL MODELS...WITH THE OPERATIONAL 12Z
GFS THE SLOWEST AT THE WESTERN END OF THE ENVELOPE. THE ECMWF AND
GGEM ARE THE QUICKEST WITH SWINGING THE FRONT ACROSS THE COAST BY
FRI MORNING. IN FACT...THE GFS CONTINUES TO BECOME MUCH SLOWER
THAN ALL THE GUIDANCE FRI INTO SAT AS THE UPPER LOW CLOSES OFF
APPROACHING THE MID ATLANTIC STATES...TAKING ON A NEGATIVE TILT
MUCH CLOSER TO THE COAST. THIS WOULD RESULT IN A PROLONGED PERIOD
OF POST-FRONTAL RAIN INTO SAT. PREFERENCE AT THIS TIME WAS TO LEAN
TOWARD THE FASTER MODEL CONSENSUS WITH PCPN SHUTTING DOWN FRI
AFT. SUBSEQUENT MODEL TRENDS WILL NEED TO BE CLOSELY MONITORED TO
SEE IF THE FRONTAL SYSTEM SLOWS DOWN EVEN FURTHER.
AS FOR THE SENSIBLE WEATHER...COLD FRONT APPROACHES FROM THE WEST
THU...PASSING ACROSS THE REGION THU NIGHT INTO FRI. HIGH PW
VALUES AND MODERATE INSTABILITY WILL LEAD TO THE DEVELOPMENT OF
WIDESPREAD SHOWERS AND THUNDERSTORMS THAT WORK WEST TO EAST
DURING THIS TIME. THE ISOLATED SEVERE THREAT APPEARS LOW AT THIS
TIME WITH THE LOW-LEVEL JET DISPLACED EAST OF THE AREA AND
MARGINAL DEEP LAYER SHEAR. UNIDIRECTIONAL WIND PROFILES SUPPORT
SOME BOWING LINE SEGMENTS WITH GUSTY WINDS. WET-BULB ZERO VALUES ARE
WARM...SUPPORTING ONLY SMALL HAIL. THE MAIN THREAT LOOKS TO BE
THE POTENTIAL FOR HEAVY RAINFALL...ESPECIALLY IF THE UPPER FLOW
BACKS FURTHER WITH THE AMPLIFICATION OF THE UPPER TROF TO THE
WEST. AVERAGE BASIN RAINFALL SHOULD BE CLOSE TO AN INCH...WITH
LOCALIZED HIGHER AMOUNTS.
A DRIER NW FLOW SET UPS FRI NIGHT WITH STRONG COLD ADVECTION. HIGH
PRESSURE BUILDS ACROSS THE GREAT LAKES AND INTO THE MID ATLANTIC
STATES THROUGH EARLY NEXT WEEK WITH TEMPERATURES SEVERAL DEGREES
BELOW SEASONABLE LEVELS.
&&
.AVIATION /04Z WEDNESDAY THROUGH SUNDAY/...
A NEARLY STATIONARY FRONT WILL REMAIN NORTH ACROSS THE LOWER HUDSON
VALLEY WHILE FARTHER EAST THE FRONT WAS MOVING WESTWARD AS A COLD
FRONT. THE FRONT WILL MAKE IT TO AROUND NEW YORK CITY BY MORNING
BEFORE MOVING BACK NORTH DURING THE MORNING.
STRATUS AND FOG WAS BEGINNING TO MOVE IN FROM THE EAST AND WILL MOVE
INTO THE NYC AREA TERMINALS FROM 08Z TO 10Z. CEILINGS AND
VISIBILITIES BECOME IFR AND AS LOW AS VLIFR AT THE COASTAL TERMINALS
ESPECIALLY AFTER 07Z. CONDITIONS IMPROVE EARLY WEDNESDAY
MORNING...13Z TO 15Z. TIMING OF IMPROVEMENT AND CONDITIONS
UNCERTAIN. WIND WILL BE LIGHT FROM THE SOUTH THROUGH THE NIGHT THEN
INCREASE TO 10 TO 15 KT DURING WEDNESDAY.
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AFTER 16Z MAINLY NORTH
AND WEST OF THE NEW YORK TERMINALS.
.OUTLOOK FOR 00Z THURSDAY THROUGH SUNDAY...
.WEDNESDAY NIGHT...SCT SHRA AND TSTMS POSSIBLE. IFR POSSIBLE IN FOG
AND STRATUS.
.THURSDAY-FRIDAY...NUMEROUS SHRA AND TSTMS POSSIBLE. IFR POSSIBLE IN
FOG AND STRATUS.
.SATURDAY...RESIDUAL SHRA BEHIND A COLD FRONT WITH MVFR. BECOMING VFR
WITH NW WINDS INCREASING TO 20-30KT.
.SUNDAY...VFR WITH NW WINDS 20-25KT.
&&
.MARINE...
DENSE FOG BEGINNING TO DEVELOP ACROSS THE EASTERN WATERS.
THIS ADVECTION FOG IS EXPECTED TO EXPAND BACK WEST OVERNIGHT.
SHALLOW BACK DOOR COLD FRONT SHOULD BRING SE-E WINDS OVERNIGHT TO
THE ERN-MOST OCEAN WATERS...ALSO LONG ISLAND SOUND AND THE BAYS OF
LONG ISLAND. OTHERWISE...S-SW SUB SCA WINDS SHOULD CONTINUE
THROUGH WED NIGHT. SEAS SHOULD SLOWLY BUILD ON WED...BUT HAVE
UNDERCUT WAVEWATCH TO PREVENT REACHING SCA CRITERIA UNTIL
WEDNESDAY NIGHT. THINKING WITH STRONG INVERSION THAT WIND FORCING
WAS OVERDONE IN THE WW3 FORECAST.
A COLD FRONT WILL MOVE ACROSS THE AREA WATERS FRIDAY MORNING...WITH
HIGH PRESSURE BUILDING THROUGH THE WEEKEND. WINDS COULD BE BELOW
SCA LEVELS BY FRIDAY MORNING...WITH SEAS ON THE OCEAN REMAINING
ABOVE SCA CRITERIA THROUGH MUCH SATURDAY MORNING. UNDERCUT
WAVEWATCH BY A FOOT DURING THIS TIME AS IT WAS SLOWER BRINGING THE
FRONTAL SYSTEM ACROSS THE AREA. THERE IS THOUGH SOME UNCERTAINTY
WITH THE SEAS DUE TO THE TIMING DIFFERENCES AMONGST THE MODELS.
&&
.HYDROLOGY...
SLIGHT CHANCE FOR SOME SHOWERS/TSTMS TO ENTER THE AREA LATE
TONIGHT INTO EARLY WED MORNING. SCT SHOWERS/TSTMS LATER WED WILL
BE CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL...WITH THE BEST
CHANCES NORTH/WEST OF NYC. TOTAL BASIN AVG QPF FOR WED-THU COULD
BE 1/4 TO 1/2 INCH...WITH LOCALLY HIGHER AMTS IN TSTMS.
A MORE ORGANIZED EVENT LATE THU INTO FRI SHOULD PRODUCE AVERAGE
BASIN RAINFALL AMOUNTS CLOSE TO AN INCH...WITH LOCALIZED HIGHER
AMOUNTS. THERE IS THE POTENTIAL FOR TRAINING OF THUNDERSTORMS
WHICH COULD RESULT IN FLASH FLOODING.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR CTZ011-012.
NY...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR NYZ079-081.
NJ...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR ANZ330-340-
345-350-353.
&&
$$
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1035 AM EDT WED MAY 22 2013
.DISCUSSION...
LARGE RIDGE AXIS OVER THE W ATLC WILL COMBINE WITH A WEAK LOW LVL
TROF CENTERED OFF THE FL BIG BEND TO GENERATE AN ACTIVE WX PATTERN
ACRS CENTRAL FL. DEEP BUT LIGHT SRLY FLOW WILL DRAW DEEP MOISTURE UP
FROM THE S...PWAT VALUES INCREASE FROM 1.5" AT KTBW/KXMR TO 1.8" AT
KMFL. RAP ANALYSIS SHOWING H100-H70 MEAN RH VALUES AOA 70PCT ACRS
THE ENTIRE PENINSULA. AIRMASS IS NOT EXPLOSIVELY UNSTABLE AS H50
TEMPS ARE HOLDING ARND -9C WITH MID LVL LAPSE RATES BTWN
5.5-6.0C/KM. HOWEVER...POSITION OF THE TROF AXIS WILL PLACE THE EAST
CENTRAL PENINSULA ON ITS ASCENDING SIDE.
ACTIVITY ALREADY DVLPG AREAWIDE WILL CONTINUE THRU THE DAY...ESP
ALNG THE EAST COAST SEA BREEZE AS IT DVLPS AND DRIFTS INLAND. THE
OFF HOUR MAV GUIDANCE CONTINUES TO INDICATE POPS BTWN 60-70PCT...
CAN SEE NO REASON TO DISCOUNT THEM AS MOISTURE IS ALMOST UNIFORMLY
DISTRIBUTED THRU THE COLUMN AND THERE ARE NO SIGNIFICANT INHIBITORS
TO UPWARD VERTICAL MOTION. MAX TEMPS WITHIN A FEW DEGS OF CLIMO
AVG...M/U80S AREAWIDE.
MINOR CHANGES TO PRECIP DISTRIBUTION AND TIMING TO FOCUS HIGHER POPS
OVER INTERIOR AND N CSTL ZONES.
&&
.AVIATION...
THRU 22/22Z...PREVAILING VFR ALL SITES...NMRS SHRAS/SCT TSRAS DVLPG
AND MVG N/NE ARND 10KTS WILL PRODUCE TEMPO IFR VSBYS/CIGS. BTWN
22/22Z-23/01Z...CONVECTION DIMINISHING BCMG SCT MVFR SHRAS W OF
KTIX-KOBE...CONTG THRU 23/03Z. AFT 23/03Z...VFR ALL SITES WITH LCL
MVFR VSBYS IN BR.
&&
.MARINE...
NO HIGHLIGHTS...NO SIG CHANGES. ATLC RIDGE AXIS OVER THE W ATLC WILL
GENERATE A LIGHT TO GENTLE S/SE BREEZE ACRS THE AREA...SEAS 2-3FT
NEARSHORE AND 3-4FT OFFSHORE. NMRS SHRAS/ISOLD TSRAS OVER THE GULF
STREAM DUE TO A MOIST AND UNSTABLE AIRMASS.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...KELLY
LONG TERM/IMPACT WX...BRAGAW
AREA FORECAST DISCUSSION...UPDATED
NWS MIAMI FL
937 AM EDT WED MAY 22 2013
.UPDATE 2...TROUGH OF LOW PRESSURE OVER THE FLORIDA PENINSULA
WILL CONTINUE TO MOVE SLOWLY EAST INTO THE WESTERN ATLANTIC WATERS
TODAY. THIS WILL ALLOW FOR A LITTLE BIT OF DRIER AIR TO WORK INTO
THE AREA FROM THE GULF OF MEXICO. HOWEVER...THE EAST AND WEST
COAST SEA BREEZES WILL DEVELOP TODAY AND PUSH INLAND. THE WEST
COAST SEA BREEZE WILL PUSH ACROSS THE AREA TODAY WITH THE EAST
COAST SEA BREEZE REMAINING NEAR THE EAST COAST METRO AREAS DUE TO
THE SOUTH TO SOUTHWEST STEERING FLOW OVER THE AREA.
SO THE SHOWERS AND THUNDERSTORMS OVER THE ATLANTIC WATERS THIS
MORNING SHOULD DISSIPATE BY NOON TIME WITH SHOWERS AND
THUNDERSTORMS DEVELOPING OVER THE LAND AREAS. SO WILL KEEP THE
SCATTERED TO NUMEROUS POPS OVER SOUTH FLORIDA FOR THIS AFTERNOON.
THERE COULD ALSO BE A FEW STRONG STORMS OVER THE INTERIOR AND EAST
COAST METRO AREAS THIS AFTERNOON INTO EARLY THIS EVENING. THE
PRIMARY IMPACTS FROM THE STRONG STORMS WILL BE GUSTY WINDS...HEAVY
RAINFALL...AND SMALL HAIL. SO WILL CONTINUE TO MENTION THIS IN THE
MORNING HWO PACKAGE.
REST OF THE FORECAST LOOKS GOOD AT THIS TIME AND NO OTHER CHANGES
ARE PLANNED.
&&
.UPDATE...54/BNB
.PREV DISCUSSION... /ISSUED 719 AM EDT WED MAY 22 2013/
AVIATION...SCATTERED SHOWERS WILL CONTINUE THIS MORNING ACROSS THE EASTERN
PORTIONS OF THE PENINSULA WITH TERMINALS KMIA...KOPF AND KTMB
POSSIBLY HAVING BRIEF PERIODS OF MVFR CEILINGS. THERE IS A LINGERING
MID TO UPPER LEVEL TROUGH AND AVAILABLE TROPICAL MOISTURE THAT IS
EXPECTED TO ENHANCE CHANCES OF CONVECTION TODAY WITH ALL TERMINALS
ASSIGNED VCTS AT 15Z EXCEPT FOR TERMINAL KAPF ASSIGNED AT 16Z. FOR
ALL TERMINALS BRIEF PERIODS OF IFR CONDITIONS MAY BE POSSIBLE WITH THE
STRONGER THUNDERSTORMS BY THE EARLY AFTERNOON.
&&
PREV DISCUSSION... /ISSUED 523 AM EDT WED MAY 22 2013/
UPDATE...SHOWERS HAVE RECENTLY INCREASED OVER THE ATLANTIC WITH
MOVEMENT ONSHORE THE COAST. SOME ARE BECOMING HEAVY WITH EVEN A
THUNDERSTORM IN FAR SOUTH MIAMI-DADE WITH A FEW LIGHTNING STRIKES
DETECTED. GIVEN THE RADAR TRENDS AND HRRR DEPICTION, HAVE INCREASED
WEATHER TO NUMEROUS FOR ALL OF THE EAST COAST AND INTERIOR THROUGH
THIS AFTERNOON. /GREGORIA
&&
PREV DISCUSSION... /ISSUED 356 AM EDT WED MAY 22 2013/
DISCUSSION...A MID-UPPER TROUGH JUST OFF THE ATLANTIC COAST WILL
GET PICKED UP AND MERGED BY A LONG WAVE TROUGH MOVING ACROSS THE
GREAT LAKES. MOISTURE AND INSTABILITY CONTINUES SUFFICIENT TODAY
TO ALLOW FOR SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS TO
DEVELOP. HRRR IS SHOWING NUMEROUS ACTIVITY THIS AFTERNOON. THE
FOCUS OF TSTORMS LOOKS TO BE ACROSS THE INTERIOR AND TO THE WEST
PALM BEACH METRO AREA. A FEW STRONG TSTORMS ARE POSSIBLE WITH
LOCALLY HEAVY RAINS THIS AFTERNOON GIVEN RESIDUAL COLD AIR ALOFT
AS WELL AS SOME UPPER LEVEL DIVERGENCE ESPECIALLY ACROSS PALM
BEACH COUNTY. HOWEVER, MID LEVEL TEMPS WILL SLOWLY BE WARMING
THROUGH THE DAY. STILL, WE WILL HIGHLIGHT A FEW STRONG TSTORMS IN
THE HAZARDOUS WEATHER OUTLOOK.
THE TREND THURSDAY AND INTO THE WEEKEND IS A DRYING ONE WITH LESS
AND LESS SHOWER AND TSTORMS ACTIVITY EXPECTED. THIS IS THE RESULT
OF THE LOCAL AREA BEING EAST OF A BUILDING RIDGE OVER THE GULF AND
WEST OF THE DEPARTING TROUGH WHICH WILL PROMOTE SUBSIDENCE. THAT
BEING SAID, THERE STILL LOOKS TO BE THE POTENTIAL FOR SCATTERED
AFTERNOON TSTORMS ALONG THE ATLANTIC COAST ON THURSDAY, AND
ISOLATED TSTORMS FRIDAY. THE TAIL END OF A COLD FRONT PUSHES INTO
FLORIDA ON FRIDAY. THIS FRONT DISSIPATES AND A STRONG SURFACE HIGH
BUILDS INTO THE EASTERN U.S. OVER THE WEEKEND. FRIDAY LOOKS HOT
AHEAD OF THE DISSIPATING FRONT WITH LOWER 90S MOST LOCALES. THEN
OVER THE WEEKEND IT TURNS BREEZY ON A NORTHEAST WIND AS THE STRONG
HIGH MOVES INTO THE OHIO VALLEY WITH A TIGHTER PRESSURE GRADIENT
LOCALLY. THE NORTHEAST WIND IS FORECAST TO LOWER DEWPOINTS INTO
THE MID 60S THIS WEEKEND, POSSIBLY EVEN LOWER 60S MAKING IT FEEL
NICE...ESPECIALLY ALONG THE ATLANTIC COAST WHERE TEMPS WILL BE
SLIGHTLY COOLER THAN THE GULF COAST ALONG WITH A STRONGER WIND.
FOR NEXT WEEK, MOISTURE WILL SLOWLY INCREASE AS WINDS TURN EAST TO
SOUTHEAST, LEADING TO AN INCREASING CHANCE OF DAILY SHOWERS AND
THUNDERSTORMS. HOWEVER, NO SIGNIFICANT WEATHER FEATURES ARE IN THE
OFFING.
MARINE...WINDS WILL BE ON THE DECREASE THIS MORNING THEN RATHER
LIGHT WINDS WILL PREVAIL THROUGH FRIDAY BEFORE WINDS TURN
NORTHEAST AND INCREASE OVER THE WEEKEND WITH A CORRESPONDING
INCREASE IN SEAS, ESPECIALLY OVER THE ATLANTIC. SWAN IS GENERATING
SEAS OF UP TO 5 FEET OVER THE ATLANTIC THIS WEEKEND.
FIRE WEATHER...NO CONCERNS AS RELATIVE HUMIDITIES REMAIN ABOVE
CRITICAL LEVELS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 86 72 87 73 / 60 40 30 20
FORT LAUDERDALE 86 74 88 76 / 60 40 30 20
MIAMI 87 74 89 76 / 60 40 30 20
NAPLES 86 71 86 72 / 30 10 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...54/BNB
AVIATION/RADAR...17/ERA
AREA FORECAST DISCUSSION
NWS MIAMI FL
719 AM EDT WED MAY 22 2013
.AVIATION...SCATTERED SHOWERS WILL CONTINUE THIS MORNING ACROSS THE EASTERN
PORTIONS OF THE PENINSULA WITH TERMINALS KMIA...KOPF AND KTMB
POSSIBLY HAVING BRIEF PERIODS OF MVFR CEILINGS. THERE IS A LINGERING
MID TO UPPER LEVEL TROUGH AND AVAILABLE TROPICAL MOISTURE THAT IS
EXPECTED TO ENHANCE CHANCES OF CONVECTION TODAY WITH ALL TERMINALS
ASSIGNED VCTS AT 15Z EXCEPT FOR TERMINAL KAPF ASSIGNED AT 16Z. FOR
ALL TERMINALS BRIEF PERIODS OF IFR CONDITIONS MAY BE POSSIBLE WITH THE
STRONGER THUNDERSTORMS BY THE EARLY AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 523 AM EDT WED MAY 22 2013/
UPDATE...SHOWERS HAVE RECENTLY INCREASED OVER THE ATLANTIC WITH
MOVEMENT ONSHORE THE COAST. SOME ARE BECOMING HEAVY WITH EVEN A
THUNDERSTORM IN FAR SOUTH MIAMI-DADE WITH A FEW LIGHTNING STRIKES
DETECTED. GIVEN THE RADAR TRENDS AND HRRR DEPICTION, HAVE INCREASED
WEATHER TO NUMEROUS FOR ALL OF THE EAST COAST AND INTERIOR THROUGH
THIS AFTERNOON. /GREGORIA
PREV DISCUSSION... /ISSUED 356 AM EDT WED MAY 22 2013/
DISCUSSION...A MID-UPPER TROUGH JUST OFF THE ATLANTIC COAST WILL
GET PICKED UP AND MERGED BY A LONG WAVE TROUGH MOVING ACROSS THE
GREAT LAKES. MOISTURE AND INSTABILITY CONTINUES SUFFICIENT TODAY
TO ALLOW FOR SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS TO
DEVELOP. HRRR IS SHOWING NUMEROUS ACTIVITY THIS AFTERNOON. THE
FOCUS OF TSTORMS LOOKS TO BE ACROSS THE INTERIOR AND TO THE WEST
PALM BEACH METRO AREA. A FEW STRONG TSTORMS ARE POSSIBLE WITH
LOCALLY HEAVY RAINS THIS AFTERNOON GIVEN RESIDUAL COLD AIR ALOFT
AS WELL AS SOME UPPER LEVEL DIVERGENCE ESPECIALLY ACROSS PALM
BEACH COUNTY. HOWEVER, MID LEVEL TEMPS WILL SLOWLY BE WARMING
THROUGH THE DAY. STILL, WE WILL HIGHLIGHT A FEW STRONG TSTORMS IN
THE HAZARDOUS WEATHER OUTLOOK.
THE TREND THURSDAY AND INTO THE WEEKEND IS A DRYING ONE WITH LESS
AND LESS SHOWER AND TSTORMS ACTIVITY EXPECTED. THIS IS THE RESULT
OF THE LOCAL AREA BEING EAST OF A BUILDING RIDGE OVER THE GULF AND
WEST OF THE DEPARTING TROUGH WHICH WILL PROMOTE SUBSIDENCE. THAT
BEING SAID, THERE STILL LOOKS TO BE THE POTENTIAL FOR SCATTERED
AFTERNOON TSTORMS ALONG THE ATLANTIC COAST ON THURSDAY, AND
ISOLATED TSTORMS FRIDAY. THE TAIL END OF A COLD FRONT PUSHES INTO
FLORIDA ON FRIDAY. THIS FRONT DISSIPATES AND A STRONG SURFACE HIGH
BUILDS INTO THE EASTERN U.S. OVER THE WEEKEND. FRIDAY LOOKS HOT
AHEAD OF THE DISSIPATING FRONT WITH LOWER 90S MOST LOCALES. THEN
OVER THE WEEKEND IT TURNS BREEZY ON A NORTHEAST WIND AS THE STRONG
HIGH MOVES INTO THE OHIO VALLEY WITH A TIGHTER PRESSURE GRADIENT
LOCALLY. THE NORTHEAST WIND IS FORECAST TO LOWER DEWPOINTS INTO
THE MID 60S THIS WEEKEND, POSSIBLY EVEN LOWER 60S MAKING IT FEEL
NICE...ESPECIALLY ALONG THE ATLANTIC COAST WHERE TEMPS WILL BE
SLIGHTLY COOLER THAN THE GULF COAST ALONG WITH A STRONGER WIND.
FOR NEXT WEEK, MOISTURE WILL SLOWLY INCREASE AS WINDS TURN EAST TO
SOUTHEAST, LEADING TO AN INCREASING CHANCE OF DAILY SHOWERS AND
THUNDERSTORMS. HOWEVER, NO SIGNIFICANT WEATHER FEATURES ARE IN THE
OFFING.
MARINE...WINDS WILL BE ON THE DECREASE THIS MORNING THEN RATHER
LIGHT WINDS WILL PREVAIL THROUGH FRIDAY BEFORE WINDS TURN
NORTHEAST AND INCREASE OVER THE WEEKEND WITH A CORRESPONDING
INCREASE IN SEAS, ESPECIALLY OVER THE ATLANTIC. SWAN IS GENERATING
SEAS OF UP TO 5 FEET OVER THE ATLANTIC THIS WEEKEND.
FIRE WEATHER...NO CONCERNS AS RELATIVE HUMIDITIES REMAIN ABOVE
CRITICAL LEVELS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 86 72 87 73 / 60 30 30 20
FORT LAUDERDALE 85 74 88 76 / 60 20 30 20
MIAMI 87 74 89 76 / 60 20 30 20
NAPLES 85 71 86 72 / 40 20 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...54/BNB
AVIATION/RADAR...17/ERA
AREA FORECAST DISCUSSION
NWS MIAMI FL
523 AM EDT WED MAY 22 2013
.UPDATE...SHOWERS HAVE RECENTLY INCREASED OVER THE ATLANTIC WITH
MOVEMENT ONSHORE THE COAST. SOME ARE BECOMING HEAVY WITH EVEN A
THUNDERSTORM IN FAR SOUTH MIAMI-DADE WITH A FEW LIGHTNING STRIKES
DETECTED. GIVEN THE RADAR TRENDS AND HRRR DEPICTION, HAVE INCREASED
WEATHER TO NUMEROUS FOR ALL OF THE EAST COAST AND INTERIOR THROUGH
THIS AFTERNOON. /GREGORIA
&&
.PREV DISCUSSION... /ISSUED 356 AM EDT WED MAY 22 2013/
DISCUSSION...A MID-UPPER TROUGH JUST OFF THE ATLANTIC COAST WILL
GET PICKED UP AND MERGED BY A LONG WAVE TROUGH MOVING ACROSS THE
GREAT LAKES. MOISTURE AND INSTABILITY CONTINUES SUFFICIENT TODAY
TO ALLOW FOR SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS TO
DEVELOP. HRRR IS SHOWING NUMEROUS ACTIVITY THIS AFTERNOON. THE
FOCUS OF TSTORMS LOOKS TO BE ACROSS THE INTERIOR AND TO THE WEST
PALM BEACH METRO AREA. A FEW STRONG TSTORMS ARE POSSIBLE WITH
LOCALLY HEAVY RAINS THIS AFTERNOON GIVEN RESIDUAL COLD AIR ALOFT
AS WELL AS SOME UPPER LEVEL DIVERGENCE ESPECIALLY ACROSS PALM
BEACH COUNTY. HOWEVER, MID LEVEL TEMPS WILL SLOWLY BE WARMING
THROUGH THE DAY. STILL, WE WILL HIGHLIGHT A FEW STRONG TSTORMS IN
THE HAZARDOUS WEATHER OUTLOOK.
THE TREND THURSDAY AND INTO THE WEEKEND IS A DRYING ONE WITH LESS
AND LESS SHOWER AND TSTORMS ACTIVITY EXPECTED. THIS IS THE RESULT
OF THE LOCAL AREA BEING EAST OF A BUILDING RIDGE OVER THE GULF AND
WEST OF THE DEPARTING TROUGH WHICH WILL PROMOTE SUBSIDENCE. THAT
BEING SAID, THERE STILL LOOKS TO BE THE POTENTIAL FOR SCATTERED
AFTERNOON TSTORMS ALONG THE ATLANTIC COAST ON THURSDAY, AND
ISOLATED TSTORMS FRIDAY. THE TAIL END OF A COLD FRONT PUSHES INTO
FLORIDA ON FRIDAY. THIS FRONT DISSIPATES AND A STRONG SURFACE HIGH
BUILDS INTO THE EASTERN U.S. OVER THE WEEKEND. FRIDAY LOOKS HOT
AHEAD OF THE DISSIPATING FRONT WITH LOWER 90S MOST LOCALES. THEN
OVER THE WEEKEND IT TURNS BREEZY ON A NORTHEAST WIND AS THE STRONG
HIGH MOVES INTO THE OHIO VALLEY WITH A TIGHTER PRESSURE GRADIENT
LOCALLY. THE NORTHEAST WIND IS FORECAST TO LOWER DEWPOINTS INTO
THE MID 60S THIS WEEKEND, POSSIBLY EVEN LOWER 60S MAKING IT FEEL
NICE...ESPECIALLY ALONG THE ATLANTIC COAST WHERE TEMPS WILL BE
SLIGHTLY COOLER THAN THE GULF COAST ALONG WITH A STRONGER WIND.
FOR NEXT WEEK, MOISTURE WILL SLOWLY INCREASE AS WINDS TURN EAST TO
SOUTHEAST, LEADING TO AN INCREASING CHANCE OF DAILY SHOWERS AND
THUNDERSTORMS. HOWEVER, NO SIGNIFICANT WEATHER FEATURES ARE IN THE
OFFING.
MARINE...WINDS WILL BE ON THE DECREASE THIS MORNING THEN RATHER
LIGHT WINDS WILL PREVAIL THROUGH FRIDAY BEFORE WINDS TURN
NORTHEAST AND INCREASE OVER THE WEEKEND WITH A CORRESPONDING
INCREASE IN SEAS, ESPECIALLY OVER THE ATLANTIC. SWAN IS GENERATING
SEAS OF UP TO 5 FEET OVER THE ATLANTIC THIS WEEKEND.
FIRE WEATHER...NO CONCERNS AS RELATIVE HUMIDITIES REMAIN ABOVE
CRITICAL LEVELS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 86 72 87 73 / 60 30 30 20
FORT LAUDERDALE 85 74 88 76 / 60 20 30 20
MIAMI 87 74 89 76 / 60 20 30 20
NAPLES 85 71 86 72 / 40 20 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MIAMI FL
356 AM EDT WED MAY 22 2013
.DISCUSSION...A MID-UPPER TROUGH JUST OFF THE ATLANTIC COAST WILL
GET PICKED UP AND MERGED BY A LONG WAVE TROUGH MOVING ACROSS THE
GREAT LAKES. MOISTURE AND INSTABILITY CONTINUES SUFFICIENT TODAY
TO ALLOW FOR SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS TO
DEVELOP. HRRR IS SHOWING NUMEROUS ACTIVITY THIS AFTERNOON. THE
FOCUS OF TSTORMS LOOKS TO BE ACROSS THE INTERIOR AND TO THE WEST
PALM BEACH METRO AREA. A FEW STRONG TSTORMS ARE POSSIBLE WITH
LOCALLY HEAVY RAINS THIS AFTERNOON GIVEN RESIDUAL COLD AIR ALOFT
AS WELL AS SOME UPPER LEVEL DIVERGENCE ESPECIALLY ACROSS PALM
BEACH COUNTY. HOWEVER, MID LEVEL TEMPS WILL SLOWLY BE WARMING
THROUGH THE DAY. STILL, WE WILL HIGHLIGHT A FEW STRONG TSTORMS IN
THE HAZARDOUS WEATHER OUTLOOK.
THE TREND THURSDAY AND INTO THE WEEKEND IS A DRYING ONE WITH LESS
AND LESS SHOWER AND TSTORMS ACTIVITY EXPECTED. THIS IS THE RESULT
OF THE LOCAL AREA BEING EAST OF A BUILDING RIDGE OVER THE GULF AND
WEST OF THE DEPARTING TROUGH WHICH WILL PROMOTE SUBSIDENCE. THAT
BEING SAID, THERE STILL LOOKS TO BE THE POTENTIAL FOR SCATTERED
AFTERNOON TSTORMS ALONG THE ATLANTIC COAST ON THURSDAY, AND
ISOLATED TSTORMS FRIDAY. THE TAIL END OF A COLD FRONT PUSHES INTO
FLORIDA ON FRIDAY. THIS FRONT DISSIPATES AND A STRONG SURFACE HIGH
BUILDS INTO THE EASTERN U.S. OVER THE WEEKEND. FRIDAY LOOKS HOT
AHEAD OF THE DISSIPATING FRONT WITH LOWER 90S MOST LOCALES. THEN
OVER THE WEEKEND IT TURNS BREEZY ON A NORTHEAST WIND AS THE STRONG
HIGH MOVES INTO THE OHIO VALLEY WITH A TIGHTER PRESSURE GRADIENT
LOCALLY. THE NORTHEAST WIND IS FORECAST TO LOWER DEWPOINTS INTO
THE MID 60S THIS WEEKEND, POSSIBLY EVEN LOWER 60S MAKING IT FEEL
NICE...ESPECIALLY ALONG THE ATLANTIC COAST WHERE TEMPS WILL BE
SLIGHTLY COOLER THAN THE GULF COAST ALONG WITH A STRONGER WIND.
FOR NEXT WEEK, MOISTURE WILL SLOWLY INCREASE AS WINDS TURN EAST TO
SOUTHEAST, LEADING TO AN INCREASING CHANCE OF DAILY SHOWERS AND
THUNDERSTORMS. HOWEVER, NO SIGNIFICANT WEATHER FEATURES ARE IN THE
OFFING.
&&
.MARINE...WINDS WILL BE ON THE DECREASE THIS MORNING THEN RATHER
LIGHT WINDS WILL PREVAIL THROUGH FRIDAY BEFORE WINDS TURN
NORTHEAST AND INCREASE OVER THE WEEKEND WITH A CORRESPONDING
INCREASE IN SEAS, ESPECIALLY OVER THE ATLANTIC. SWAN IS GENERATING
SEAS OF UP TO 5 FEET OVER THE ATLANTIC THIS WEEKEND.
&&
.FIRE WEATHER...NO CONCERNS AS RELATIVE HUMIDITIES REMAIN ABOVE
CRITICAL LEVELS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 86 72 87 73 / 60 30 30 20
FORT LAUDERDALE 85 74 88 76 / 50 20 30 20
MIAMI 87 74 89 76 / 50 20 30 20
NAPLES 85 71 86 72 / 40 20 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...57/GREGORIA
AVIATION/RADAR...60/BD
AREA FORECAST DISCUSSION
NWS MIAMI FL
144 AM EDT WED MAY 22 2013
.AVIATION...
FOR THE SHORT TERM...PASSING SHOWERS WILL LIKELY AFFECT ALL EAST
COAST TERMINALS EXCEPT KPBI FOR THE NEXT FEW HOURS. LOW CONFIDENCE
OF AN ISOLATED THUNDERSTORM OCCURRING IN THIS PERIOD WITH BRIEF
PERIODS OF MVFR CEILINGS POSSIBLE WITH PASSING SHOWERS. BY LATE
WEDNESDAY MORNING AND INTO THE AFTERNOON HOURS...THE COMBINATION
OF THE WEST AND EAST COAST SEA BREEZES...A LINGERING UPPER LEVEL LOW
AND AVAILABLE MOISTURE SHOULD RESULT IN VCTS ALL TERMINALS AROUND
15Z.
60
&&
.PREV DISCUSSION... /ISSUED 949 PM EDT TUE MAY 21 2013/
UPDATE...
UPDATED PRODUCTS EARLIER TO CANCEL FLOOD WATCH BUT HAVE KEPT SCT
POPS GOING THROUGH THE NIGHT. IT APPEARS THAT THE HEAVY RAIN
THREAT IS OVER, BUT WITH THE UPPER LOW STILL IN THE VICINITY
CANNOT RULE OUT A POSSIBLE STORM JUST ABOUT ANYWHERE AT ANY TIME.
LOW LEVEL FLOW CONTINUES SOUTHEASTERLY SO THE GREATEST THREAT WILL
BE THE SOUTHEAST COAST ESPECIALLY IF A LITTLE BIT OF CONVERGENCE
CAN SET UP WITH LESSENING FLOW NEAR THE COAST. THE HRRR CYCLE
SEEMS TO CHANGE EVERY TWO TO THREE HOURS BUT THE LATEST RUN IS
SHOWING QUIET ACTIVITY THROUGH 06Z BUT THE EARLIER RUN HAD SHOWN A
FLARE UP OF CONVECTION LATER TONIGHT ALTHOUGH NOT WIDESPREAD.
KOB
PREV DISCUSSION... /ISSUED 758 PM EDT TUE MAY 21 2013/
AVIATION...
THE SHOWERS AND SHOULD COME TO AN END OVER SOUTH FLORIDA BY 03Z
TONIGHT AND REMAIN DRY THROUGH 15Z ON WEDNESDAY. SO WILL KEEP VCSH
IN THE ALL OF SOUTH FLORIDA TAF SITES UNTIL 03Z...BEFORE GOING DRY
FOR REST OF TONIGHT. THE WINDS TONIGHT WILL ALSO REMAIN IN A
EASTERLY DIRECTION AT 5 KNOTS OR LESS TONIGHT AT ALL OF THE TAF
SITES.
ON WEDNESDAY...THE WEATHER WILL REMAIN DRY UNTIL 15Z BEFORE
SCATTERED SHOWERS AND THUNDERSTORMS DEVELOP OVER SOUTH FLORIDA. SO
WILL PUT IN A VCTS FOR ALL OF SOUTH FLORIDA TAF SITES AFTER 15Z ON
WEDNESDAY. THE EASTERLY WINDS WILL ALSO INCREASE TO AROUND 10
KNOTS WEDNESDAY MORNING AT ALL OF THE TAF SITES AND REMAIN
EASTERLY AT 10 KNOTS THROUGH WEDNESDAY AFTERNOON. THE ONLY
EXCEPTION TO THIS IS AT KAPF TAF SITE...WHERE THE WIND DIRECTION
WILL BECOME WESTERLY DUE TO THE WEST COAST SEA BREEZE PUSHING INLAND.
THE CEILING AND VIS WILL ALSO REMAIN IN THE VFR CONDITION TONIGHT
INTO WEDNESDAY AT ALL OF THE TAF SITES.
AVIATION...54/BNB
PREV DISCUSSION... /ISSUED 245 PM EDT TUE MAY 21 2013/
FLOOD WATCH IN EFFECT UNTIL 10 PM EDT THIS EVENING FOR EAST
COAST METRO AREAS...
SHORT TERM...
THE EAST AND WEST COAST SEA BREEZES WERE DEVELOPING ALONG BOTH
COASTS OF SOUTH FLORIDA EARLY THIS AFTERNOON. THESE SEA BREEZES
WILL PUSH SLOWLY INLAND THROUGH THE REST OF THE AFTERNOON HOURS
HELPING TO GENERATE SHOWERS AND THUNDERSTORMS OVER THE AREA. THE
STORMS WILL BE SLOW MOVING THIS AFTERNOON INTO THIS EVENING...AS
THE STEERING FLOW WILL BE LIGHT FROM THE SOUTH AHEAD OF A TROUGH
OF LOW PRESSURE LOCATED OVER THE EASTERN GULF OF MEXICO.
THE GPS-MET SATELLITE IMAGES WHERE SHOWING THE PWAT VALUES TO BE
BETWEEN 1.6 TO 1.7 INCHES EARLY THIS AFTERNOON OVER SOUTH
FLORIDA. THE AVERAGE PWAT VALUE FOR THIS TIME OF YEAR IS AROUND
1.35 INCHES FOR SOUTH FLORIDA. THIS WILL ALLOW FOR HEAVY RAINFALL
OVER SOUTH FLORIDA THIS AFTERNOON INTO THIS EVENING. SO, WILL
CONTINUE TO MENTION HEAVY RAINFALL IN THE FORECAST FOR SOUTH
FLORIDA FOR THIS AFTERNOON INTO THIS EVENING.
THE HEAVY RAINFALL FROM THE STORMS THIS AFTERNOON INTO THIS
EVENING OVER THE EAST COAST METRO AREAS WILL ALLOW FOR SOME
FLOODING TO OCCUR...AS THE GROUNDS ARE VERY SATURATED FROM THE
HEAVY RAINFALL FROM THE STORMS YESTERDAY. THEREFORE...THE FLOOD
WATCH WILL REMAIN IN PLACE OVER THE EAST COAST METRO AREAS THROUGH
LATE THIS EVENING.
THE MID TO UPPER LEVEL TROUGH OVER THE EASTERN GULF OF MEXICO WILL
MOVE EAST TONIGHT THROUGH THE FLORIDA PENINSULA AS THE UPPER LEVEL
LOW OVER NORTHERN FLORIDA MOVES EAST INTO THE WESTERN ATLANTIC
WATERS. THIS WILL ALLOW FOR THE DEEPER MOISTURE OVER SOUTH FLORIDA
TO MOVE EAST INTO THE WESTERN ATLANTIC WATERS ON WEDNESDAY WHICH
WILL ALLOW FOR SOME DRIER AIR TO WORK INTO THE AREA FROM THE
CENTRAL GULF OF MEXICO. THE DRIER AIR WILL STICK AROUND ON
THURSDAY OVER SOUTH FLORIDA. HOWEVER...THERE WILL STILL BE ENOUGH
MOISTURE OVER SOUTH FLORIDA EACH DAY TO ALLOW FOR SCATTERED
SHOWERS AND THUNDERSTORMS TO DEVELOP OVER THE AREA ON WEDNESDAY
AND THURSDAY ALONG THE SEA BREEZES WITH THE BEST COVERAGE OVER THE
INTERIOR AREAS.
LONG TERM...
A COLD FRONT LOCATED OVER THE CENTRAL UNITED STATES IS FORECAST BY
THE LONG RANGE MODELS TO MOVE SOUTHEAST AND THROUGH SOUTH FLORIDA
EARLY THIS WEEKEND. HIGH PRESSURE SHOULD THEN BUILD INTO THE AREA
FROM THE NORTH LATE THIS WEEKEND INTO EARLY NEXT WEEK. THIS WILL
ALLOW FOR MUCH DRIER AIR TO WORK INTO THE AREA FROM THE NORTH FOR
LATE THIS WEEKEND INTO EARLY NEXT WEEK. SO WILL KEEP A SLIGHT
CHANCE OF POPS OVER SOUTH FLORIDA FOR THE EARLY PART OF THIS
WEEKEND BEFORE GOING DRY FOR THE SECOND HALF OF THIS WEEKEND INTO
EARLY NEXT WEEK.
AVIATION...
SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP AND
PUSH SLOWLY NORTH THROUGH THE AFTERNOON HOURS. SO KEPT VCTS FOR ALL
TAF SITES THROUGH THE AFTERNOON. A FEW SHOWERS MAY MOVE NEAR THE
EAST COAST TAF SITES OVERNIGHT. AN UPPER LEVEL TROUGH WILL SHIFT
EAST TONIGHT INTO WEDNESDAY...PUSHING THE BEST DYNAMICS OVER THE
ATLANTIC WATERS. SO THUNDERSTORM ACTIVITY IS EXPECTED TO START NEAR
THE END OF THE TAF PERIOD ALONG THE SEA BREEZE BOUNDARIES.
MARINE...
THE WINDS WILL BE SOUTHERLY BELOW 10 KNOTS THROUGH LATE THIS
WEEK...BEFORE INCREASING TO BREEZY CONDITIONS FROM THE NORTHEAST
DIRECTION FOR THIS WEEKEND. THIS WILL ALLOW FOR THE SEAS TO REMAIN
BELOW 6 FEET FOR BOTH THE ATLANTIC AND GULF WATERS OF SOUTH
FLORIDA THROUGH LATE THIS WEEK INTO EARLY THIS WEEKEND...BEFORE
INCREASING TO AROUND 6 FEET IN THE GULF STREAM WATERS OF THE
ATLANTIC BY LATE THIS WEEKEND.
FIRE WEATHER...
THE RELATIVE HUMIDITY WILL REMAIN ABOVE THE 35 PERCENT CRITICAL
VALUE OVER SOUTH FLORIDA THROUGH REST OF THIS WEEK. SO NO PROBLEMS
ARE EXPECTED WITH THE FIRE WEATHER OVER SOUTH FLORIDA.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 86 74 88 73 / 50 40 30 30
FORT LAUDERDALE 86 77 88 76 / 50 30 30 20
MIAMI 87 76 89 75 / 50 30 30 20
NAPLES 87 71 88 71 / 40 20 20 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...57/DG
AVIATION/RADAR...60/BD
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
600 PM CDT WED MAY 22 2013
...UPDATE TO AVIATION FOR 00Z TAFS...
.SYNOPSIS...
ISSUED AT 340 PM CDT WED MAY 22 2013
THE 12Z UPPER AIR ANALYSIS SHOWED THE REMAINS OF THE NORTHERN PLAINS
CLOSED LOW WEAKENING OVER SOUTHERN MINNESOTA AS IT IS GETTING PHASED
WITH A STRONG SHORTWAVE TROUGH OVER HUDSON`S BAY. A DEEP CLOSED LOW
WAS OVER THE PACIFIC NORTHWEST. IN BETWEEN THESE FEATURES, WEAK
UPPER LEVEL RIDGING EXTENDED FROM CENTRAL CANADA SOUTHWARD ALONG THE
EASTERN SLOPES OF THE ROCKIES AND ADJACENT HIGH PLAINS.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 340 PM CDT WED MAY 22 2013
THE UPPER LOW WILL CONTINUE TO FILL AS IT MOVES INTO THE GREAT
LAKES ON THURSDAY. AS IT MOVES OUT, A SHORTWAVE TROUGH WILL ROTATE
AROUND THE WEST PART OF THE UPPER LOW, WHICH WILL HELP PUSH A COLD
FRONT SOUTH INTO THE CENTRAL HIGH PLAINS TONIGHT. A WEAK DISTURBANCE
WAS EVIDENT IN THE WATER VAPOR IMAGERY MOVING OUT OF THE FOUR
CORNERS REGION THIS AFTERNOON. THE MODELS ARE NOT PICKING UP ON
THIS FEATURE VERY WELL. THEY DO SHOW SOME WARM AIR ADVECTION
DEVELOPING AHEAD OF IT OVER WESTERN KANSAS TONIGHT ALONG WITH SOME
VERY WEAK ELEVATED INSTABILITY ATOP THE COLD FRONT AND LOW LEVEL
COLD ADVECTION THAT WILL BE MOVING INTO WESTERN KANSAS THIS EVENING.
THE HRRR IS STARTING TO SHOW CONVECTION DEVELOPING OVER EASTERN
COLORADO THIS EVENING WORKING INTO WESTERN KANSAS OVERNIGHT. LOW
STRATUS IS ALSO EXPECTED TO DEVELOP BEHIND THE FRONT TONIGHT.
ON THURSDAY, SMALL CHANCES FOR SHOWERS AND THUNDERSTORMS WILL MOVE
INTO CENTRAL KANSAS WHERE THE BEST, ALBEIT WEAK, ELEVATED INSTABILITY
WILL BE. AREAS FARTHER WEST WILL BE CLOUDY TO MOSTLY CLOUDY BUT
STABLE ALOFT. HIGH TEMPERATURES WILL STRUGGLE INTO THE LOW 70S IN
MOST AREAS GIVEN THE CLOUD COVER. AREAS ALONG THE OKLAHOMA BORDER
COULD REACH THE LOW/MID 70S.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 348 PM CDT WED MAY 22 2013
LOW LEVEL MOISTURE WILL SURGE BACK TO THE NORTHWEST INTO THE
SOUTHERN PLAINS BY LATE THURSDAY AS UPPER LEVEL TROUGHING DEVELOPS
ACROSS THE WESTERN UNITED STATES. SURGE HIGH PRESSURE WILL SLIDE
SOUTHEASTWARD INTO THE MIDWEST. A WARM ADVECTION PATTERN WILL
STRENGTHEN THURSDAY NIGHT AND SOME ELEVATED THUNDERSTORM ACTIVITY
IS POSSIBLE. THE UPPER LEVEL RIDGE AXIS BETWEEN THE WESTERN AND
EASTERN UNITED STATES TROUGHS WILL BE OVER THE CENTRAL PLAINS BY
FRIDAY. BUT SOME MID LEVEL FLOW COMING THROUGH THE RIDGE WILL
ALLOW FOR LEE TROUGHING AND A SURGE OF MOISTURE FROM THE SOUTHERN
PLAINS INTO KANSAS. WESTERN KANSAS WILL BE ON THE SOUTHERN EDGE OF
THE WESTERLIES AND THE UPPER LEVEL WINDS WILL NOT BE THAT
IMPRESSIVE. HOWEVER, WITH 2000-3000 J/KG CAPE AND STRONG
DIRECTIONAL TURNING, A FEW SEVERE THUNDERSTORMS ARE POSSIBLE,
PARTICULARLY IN FAR SOUTHWEST KANSAS. HIGH TEMPERATURES FRIDAY WILL
RANGE FROM THE UPPER 70S NEAR HAYS TO THE UPPER 80S IN FAR
SOUTHWEST KANSAS CLOSER TO THE LEE TROUGH.
UPPER LEVEL TROUGHING WILL REMAIN ACROSS THE WESTERN UNITED STATES
THROUGH MID NEXT WEEK, ALTHOUGH THERE IS SOME UNCERTAINTY IN HOW
FAR EAST IT WILL PROGRESS. THE ECMWF IS LESS PROGRESSIVE THAN THE
OTHER MODELS AND GENERALLY A LESS PROGRESSIVE SOLUTION IS THE BEST
ONE. FOR SATURDAY INTO MONDAY, MODERATE TO HIGH SURFACE BASED CAPE
WILL BE IN PLACE AHEAD OF A DRYLINE. A FEW THUNDERSTORMS WILL
DEVELOP EACH DAY ALONG THE DRYLINE AND SLOWLY MOVE EASTWARD. THESE
STORMS COULD BE SEVERE WITH LARGE HAIL AND DAMAGING WINDS. THE
UPPER LEVEL WINDS ARE STILL NOT PROGGED TO BE THAT STRONG, SO
TORNADIC STORMS ARE NOT EXPECTED, BUT CANNOT BE RULED OUT GIVEN THE
STRONG INSTABILITY. TEMPERATURES WILL BE FAIRLY WARM THROUGH THE
EXTENDED WITH LOWS IN THE 60S AND HIGHS IN THE 80S AND 90S SINCE
KANSAS WILL BE IN THE WARM SECTOR. THE WARMEST HIGH TEMPERATURES
OUGHT TO BE IN FAR WESTERN KANSAS BEHIND THE DRYLINE AND THE
WARMEST LOWS SHOULD BE IN SOUTH CENTRAL AND CENTRAL KANSAS WHERE
DEWPOINTS AND WINDS WILL BE HIGHEST.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 600 PM CDT WED MAY 22 2013
LIGHT AND VARIABLE WINDS WILL EVENTUALLY BECOME NE/E 10-20 KT THROUGH
THE OVERNIGHT HOURS. THESE UPSLOPE WINDS WILL CONTINUE INTO EARLY AFTERNOON
AS WELL. STRATUS IS EXPECTED TO DEVELOP LATE TONIGHT. VFR OR MVFR CIGS
EXPECTED. ISOLATED THREAT OF TS LATE TONIGHT BUT WILL KEEP OUT OF KGCK
TAF FOR NOW DUE TO ISOLATED NATURE. BETTER CHANCE FOR THUNDERSTORMS
TOMORROW.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 51 72 58 81 / 10 20 40 30
GCK 50 71 58 83 / 10 20 30 40
EHA 52 76 59 88 / 10 30 30 40
LBL 53 74 60 87 / 10 30 30 40
HYS 47 71 56 77 / 10 20 40 40
P28 54 73 59 78 / 10 30 30 40
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GERARD
SHORT TERM...GERARD
LONG TERM...FINCH
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
356 PM CDT WED MAY 22 2013
...UPDATED FOR LONG TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 340 PM CDT WED MAY 22 2013
THE 12Z UPPER AIR ANALYSIS SHOWED THE REMAINS OF THE NORTHERN PLAINS
CLOSED LOW WEAKENING OVER SOUTHERN MINNESOTA AS IT IS GETTING PHASED
WITH A STRONG SHORTWAVE TROUGH OVER HUDSON`S BAY. A DEEP CLOSED LOW
WAS OVER THE PACIFIC NORTHWEST. IN BETWEEN THESE FEATURES, WEAK
UPPER LEVEL RIDGING EXTENDED FROM CENTRAL CANADA SOUTHWARD ALONG THE
EASTERN SLOPES OF THE ROCKIES AND ADJACENT HIGH PLAINS.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 340 PM CDT WED MAY 22 2013
THE UPPER LOW WILL CONTINUE TO FILL AS IT MOVES INTO THE GREAT
LAKES ON THURSDAY. AS IT MOVES OUT, A SHORTWAVE TROUGH WILL ROTATE
AROUND THE WEST PART OF THE UPPER LOW, WHICH WILL HELP PUSH A COLD
FRONT SOUTH INTO THE CENTRAL HIGH PLAINS TONIGHT. A WEAK DISTURBANCE
WAS EVIDENT IN THE WATER VAPOR IMAGERY MOVING OUT OF THE FOUR
CORNERS REGION THIS AFTERNOON. THE MODELS ARE NOT PICKING UP ON
THIS FEATURE VERY WELL. THEY DO SHOW SOME WARM AIR ADVECTION
DEVELOPING AHEAD OF IT OVER WESTERN KANSAS TONIGHT ALONG WITH SOME
VERY WEAK ELEVATED INSTABILITY ATOP THE COLD FRONT AND LOW LEVEL
COLD ADVECTION THAT WILL BE MOVING INTO WESTERN KANSAS THIS EVENING.
THE HRRR IS STARTING TO SHOW CONVECTION DEVELOPING OVER EASTERN
COLORADO THIS EVENING WORKING INTO WESTERN KANSAS OVERNIGHT. LOW
STRATUS IS ALSO EXPECTED TO DEVELOP BEHIND THE FRONT TONIGHT.
ON THURSDAY, SMALL CHANCES FOR SHOWERS AND THUNDERSTORMS WILL MOVE
INTO CENTRAL KANSAS WHERE THE BEST, ALBEIT WEAK, ELEVATED INSTABILITY
WILL BE. AREAS FARTHER WEST WILL BE CLOUDY TO MOSTLY CLOUDY BUT
STABLE ALOFT. HIGH TEMPERATURES WILL STRUGGLE INTO THE LOW 70S IN
MOST AREAS GIVEN THE CLOUD COVER. AREAS ALONG THE OKLAHOMA BORDER
COULD REACH THE LOW/MID 70S.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 348 PM CDT WED MAY 22 2013
LOW LEVEL MOISTURE WILL SURGE BACK TO THE NORTHWEST INTO THE
SOUTHERN PLAINS BY LATE THURSDAY AS UPPER LEVEL TROUGHING DEVELOPS
ACROSS THE WESTERN UNITED STATES. SURGE HIGH PRESSURE WILL SLIDE
SOUTHEASTWARD INTO THE MIDWEST. A WARM ADVECTION PATTERN WILL
STRENGTHEN THURSDAY NIGHT AND SOME ELEVATED THUNDERSTORM ACTIVITY
IS POSSIBLE. THE UPPER LEVEL RIDGE AXIS BETWEEN THE WESTERN AND
EASTERN UNITED STATES TROUGHS WILL BE OVER THE CENTRAL PLAINS BY
FRIDAY. BUT SOME MID LEVEL FLOW COMING THROUGH THE RIDGE WILL
ALLOW FOR LEE TROUGHING AND A SURGE OF MOISTURE FROM THE SOUTHERN
PLAINS INTO KANSAS. WESTERN KANSAS WILL BE ON THE SOUTHERN EDGE OF
THE WESTERLIES AND THE UPPER LEVEL WINDS WILL NOT BE THAT
IMPRESSIVE. HOWEVER, WITH 2000-3000 J/KG CAPE AND STRONG
DIRECTIONAL TURNING, A FEW SEVERE THUNDERSTORMS ARE POSSIBLE,
PARTICULARLY IN FAR SOUTHWEST KANSAS. HIGH TEMPERATURES FRIDAY WILL
RANGE FROM THE UPPER 70S NEAR HAYS TO THE UPPER 80S IN FAR
SOUTHWEST KANSAS CLOSER TO THE LEE TROUGH.
UPPER LEVEL TROUGHING WILL REMAIN ACROSS THE WESTERN UNITED STATES
THROUGH MID NEXT WEEK, ALTHOUGH THERE IS SOME UNCERTAINTY IN HOW
FAR EAST IT WILL PROGRESS. THE ECMWF IS LESS PROGRESSIVE THAN THE
OTHER MODELS AND GENERALLY A LESS PROGRESSIVE SOLUTION IS THE BEST
ONE. FOR SATURDAY INTO MONDAY, MODERATE TO HIGH SURFACE BASED CAPE
WILL BE IN PLACE AHEAD OF A DRYLINE. A FEW THUNDERSTORMS WILL
DEVELOP EACH DAY ALONG THE DRYLINE AND SLOWLY MOVE EASTWARD. THESE
STORMS COULD BE SEVERE WITH LARGE HAIL AND DAMAGING WINDS. THE
UPPER LEVEL WINDS ARE STILL NOT PROGGED TO BE THAT STRONG, SO
TORNADIC STORMS ARE NOT EXPECTED, BUT CANNOT BE RULED OUT GIVEN THE
STRONG INSTABILITY. TEMPERATURES WILL BE FAIRLY WARM THROUGH THE
EXTENDED WITH LOWS IN THE 60S AND HIGHS IN THE 80S AND 90S SINCE
KANSAS WILL BE IN THE WARM SECTOR. THE WARMEST HIGH TEMPERATURES
OUGHT TO BE IN FAR WESTERN KANSAS BEHIND THE DRYLINE AND THE
WARMEST LOWS SHOULD BE IN SOUTH CENTRAL AND CENTRAL KANSAS WHERE
DEWPOINTS AND WINDS WILL BE HIGHEST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1237 PM CDT WED MAY 22 2013
VFR CONDITIONS WITH LIGHT AND VARIABLE WINDS CAN BE EXPECTED
THROUGH THE AFTERNOON HOURS. A COLD FRONT IS EXPECTED TO PUSH
THROUGH WESTERN KANSAS TONIGHT. WINDS WILL SWITCH AROUND TO THE
EAST TO NORTHEAST BEHIND THE FRONT AND COULD BECOME GUSTY TO
AROUND 20-25 KNOTS AT TIMES. STRATUS IS EXPECTED TO DEVELOP LATER
TONIGHT ESPECIALLY OVER SOUTHWEST KANSAS. HAVE INTRODUCED LOW MVFR
CIGS TO GARDEN CITY AND DODGE CITY BY 10Z THURSDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 51 72 58 81 / 10 20 40 30
GCK 50 71 58 83 / 10 20 30 40
EHA 52 76 59 88 / 10 30 30 40
LBL 53 74 60 87 / 10 30 30 40
HYS 47 71 56 77 / 10 20 40 40
P28 54 73 59 78 / 10 30 30 40
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GERARD
SHORT TERM...GERARD
LONG TERM...FINCH
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
343 PM CDT WED MAY 22 2013
...UPDATED SYNOPSIS AND SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 340 PM CDT WED MAY 22 2013
THE 12Z UPPER AIR ANALYSIS SHOWED THE REMAINS OF THE NORTHERN PLAINS
CLOSED LOW WEAKENING OVER SOUTHERN MINNESOTA AS IT IS GETTING PHASED
WITH A STRONG SHORTWAVE TROUGH OVER HUDSON`S BAY. A DEEP CLOSED LOW
WAS OVER THE PACIFIC NORTHWEST. IN BETWEEN THESE FEATURES, WEAK
UPPER LEVEL RIDGING EXTENDED FROM CENTRAL CANADA SOUTHWARD ALONG THE
EASTERN SLOPES OF THE ROCKIES AND ADJACENT HIGH PLAINS.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 340 PM CDT WED MAY 22 2013
THE UPPER LOW WILL CONTINUE TO FILL AS IT MOVES INTO THE GREAT
LAKES ON THURSDAY. AS IT MOVES OUT, A SHORTWAVE TROUGH WILL ROTATE
AROUND THE WEST PART OF THE UPPER LOW, WHICH WILL HELP PUSH A COLD
FRONT SOUTH INTO THE CENTRAL HIGH PLAINS TONIGHT. A WEAK DISTURBANCE
WAS EVIDENT IN THE WATER VAPOR IMAGERY MOVING OUT OF THE FOUR
CORNERS REGION THIS AFTERNOON. THE MODELS ARE NOT PICKING UP ON
THIS FEATURE VERY WELL. THEY DO SHOW SOME WARM AIR ADVECTION
DEVELOPING AHEAD OF IT OVER WESTERN KANSAS TONIGHT ALONG WITH SOME
VERY WEAK ELEVATED INSTABILITY ATOP THE COLD FRONT AND LOW LEVEL
COLD ADVECTION THAT WILL BE MOVING INTO WESTERN KANSAS THIS EVENING.
THE HRRR IS STARTING TO SHOW CONVECTION DEVELOPING OVER EASTERN
COLORADO THIS EVENING WORKING INTO WESTERN KANSAS OVERNIGHT. LOW
STRATUS IS ALSO EXPECTED TO DEVELOP BEHIND THE FRONT TONIGHT.
ON THURSDAY, SMALL CHANCES FOR SHOWERS AND THUNDERSTORMS WILL MOVE
INTO CENTRAL KANSAS WHERE THE BEST, ALBEIT WEAK, ELEVATED INSTABILITY
WILL BE. AREAS FARTHER WEST WILL BE CLOUDY TO MOSTLY CLOUDY BUT
STABLE ALOFT. HIGH TEMPERATURES WILL STRUGGLE INTO THE LOW 70S IN
MOST AREAS GIVEN THE CLOUD COVER. AREAS ALONG THE OKLAHOMA BORDER
COULD REACH THE LOW/MID 70S.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 415 AM CDT WED MAY 22 2013
MEDIUM RANGE MODELS INDICATE A WEAK UPPER LEVEL RIDGE OF HIGH
PRESSURE MOVING EAST INTO THE CENTRAL PLAINS THURSDAY AS A STRONG
CLOSED OFF LOW REMAINS ANCHORED ACROSS THE PACIFIC NORTHWEST. THIS
WILL SET UP A MORE DIVERGENT FLOW ALOFT ACROSS THE WESTERN HIGH
PLAINS AS A PREVAILING EASTERLY UPSLOPE FLOW CONTINUES TO SLOWLY
ADVECT MOISTURE INTO THE REGION NEAR THE SURFACE. THIS WILL BRING
THE POSSIBILITY FOR SHOWERS AND POTENTIALLY THUNDERSTORMS TO
PORTIONS OF WESTERN KANSAS THURSDAY AFTERNOON AND EVENING AS AN
UPPER LEVEL JET CORE LIFTS NORTHEAST OUT OF THE DESERT SOUTHWEST
INTO THE TEXAS PANHANDLE AND SOUTHERN KANSAS. HOWEVER, NAM AND GFS
MODEL SOUNDINGS SHOW A LACK OF SIGNIFICANT INSTABILITY, NOT TO
MENTION A POSSIBLE CAPPING ISSUE THAT COULD LIMIT THE POTENTIAL
FOR THUNDERSTORMS. STILL, UPSLOPE AND INCREASED LOW LEVEL
CONVERGENCE DUE TO A FRONTAL BOUNDARY PROJECTED TO EXTEND FROM
SOUTHEAST COLORADO INTO THE TEXAS PANHANDLE MAY SUPPORT RAIN
SHOWER DEVELOPMENT FROM THE TEXAS PANHANDLE NORTHEAST INTO
PORTIONS OF SOUTHWEST KANSAS THURSDAY WITH A SLIGHT CHANCE FOR
AN EMBEDDED THUNDERSTORM OR TWO.
THUNDERSTORM CHANCES INCREASE FRIDAY AS THE UPPER LEVEL RIDGE AXIS
SHIFTS SLIGHTLY EASTWARD WHILE SURFACE TROUGHING DEVELOPS AND
STRENGTHENS ACROSS EASTERN COLORADO HELPING TO DRAW THE FRONTAL
BOUNDARY NORTHWARD ACROSS WESTERN KANSAS. THIS WILL RESULT IN
INCREASING INSTABILITY ACROSS THE REGION BETTER SUPPORTING POTENTIAL
THUNDERSTORM DEVELOPMENT ACROSS SOUTHWEST AND CENTRAL KANSAS. THE
UPPER LEVEL PATTERN IS EXPECTED TO CHANGE VERY LITTLE THROUGHOUT
THE REMAINDER OF THE WEEKEND BRINGING A CHANCE FOR THUNDERSTORMS
TO CENTRAL AND PORTIONS OF WESTERN KANSAS EACH DAY THROUGH SUNDAY.
BELOW NORMAL TEMPERATURES ARE EXPECTED THURSDAY AS SURFACE HIGH
PRESSURE DROPS SOUTHEAST FROM THE NORTHERN PLAINS INTO THE UPPER
MIDWEST. THIS WILL HELP USHER SLIGHTLY COOLER AIR SOUTHWESTWARD
INTO THE WESTERN HIGH PLAINS WITH H85 TEMPERATURES JUST ABOVE 10C
ACROSS CENTRAL KANSAS TO THE MID TO UPPER TEENS(C) IN FAR SOUTHWEST
KANSAS. ALONG WITH EXPECTED INCREASING CLOUDS, LOOK FOR HIGHS ONLY
UP INTO THE 70S(F) THURSDAY AFTERNOON WITH THE COOLEST TEMPERATURES
IN CENTRAL KANSAS. A WARM FRONT IS PROJECTED TO LIFT NORTH ACROSS
WESTERN KANSAS FRIDAY AS SURFACE TROUGHING STRENGTHENS ACROSS
EASTERN COLORADO. EXPECT SLIGHTLY WARMER TEMPERATURES FRIDAY
AFTERNOON WITH HIGHS UP INTO THE MID TO UPPER 70S(F) ACROSS
CENTRAL KANSAS TO THE LOWER AND POSSIBLY THE MID 80S(F) IN EXTREME
SOUTHWEST KANSAS. THE WARMING TREND CONTINUES THROUGH THE WEEKEND
WITH WIDESPREAD 80S(F) TO NEAR 90F SATURDAY AND SUNDAY AS THE LOW
LEVEL SOUTHERLY FLOW PERSISTS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1237 PM CDT WED MAY 22 2013
VFR CONDITIONS WITH LIGHT AND VARIABLE WINDS CAN BE EXPECTED
THROUGH THE AFTERNOON HOURS. A COLD FRONT IS EXPECTED TO PUSH
THROUGH WESTERN KANSAS TONIGHT. WINDS WILL SWITCH AROUND TO THE
EAST TO NORTHEAST BEHIND THE FRONT AND COULD BECOME GUSTY TO
AROUND 20-25 KNOTS AT TIMES. STRATUS IS EXPECTED TO DEVELOP LATER
TONIGHT ESPECIALLY OVER SOUTHWEST KANSAS. HAVE INTRODUCED LOW MVFR
CIGS TO GARDEN CITY AND DODGE CITY BY 10Z THURSDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 51 72 58 81 / 10 20 40 30
GCK 50 71 58 83 / 10 20 30 40
EHA 52 76 59 88 / 10 30 30 40
LBL 53 74 60 87 / 10 30 30 40
HYS 47 71 56 77 / 10 20 40 40
P28 54 73 59 78 / 10 30 30 40
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GERARD
SHORT TERM...GERARD
LONG TERM...JJOHNSON
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS TOPEKA KS
326 AM CDT WED MAY 22 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 307 AM CDT WED MAY 22 2013
NORTHWEST FLOW BEGINNING TO TAKE OVER THE LOCAL AREA AS THE
SLOW-MOVING NORTHERN PLAINS SYSTEM INCHES EASTWARD. A WEAK POTENTIAL
VORTICITY ANOMALY WAS ROTATING SOUTHEAST INTO NORTHEAST KANSAS IN
RECENT HOURS WITH ONLY SOME HIGH CLOUDS RESULTING IN SOMEWHAT DRY
MID LEVELS. PERIODIC LOWER CLOUDS ALSO MAKING THEIR WAY SOUTHEAST
INTO KANSAS.
LOW-MID LEVEL MOISTURE WILL BE ON THE INCREASE TODAY...THOUGH
FORCING FOR PRECIPITATION WILL BE LACKING ON THE SOUTHWEST SIDE OF
THE SYSTEM AND IN DEEP BUT WEAK ISENTROPIC DOWNGLIDE. THE INCREASED
CLOUDS AND SOME COLD AIR ADVECTION ON NORTHWEST WINDS SHOULD KEEP
TEMPS A BIT COOLER THAN TUESDAY. SOME CLEARING SHOULD TAKE PLACE
TONIGHT AS RIDGING BEGINS TO DEVELOP THROUGH THE TROPOSPHERE WITH
ENOUGH WIND TO KEEP FOG IN CHECK.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 307 AM CDT WED MAY 22 2013
THURS THRU SAT...COOL HIGH PRESSURE CONTINUES TO PUSH SOUTH AND EAST
OF THE AREA WED NIGHT THROUGH THURSDAY...AND ANTICIPATE ANOTHER
DAY OF BELOW NORMAL HIGHS IN THE UPPER 60S NORTH TO MID 70S SOUTH.
FAR WESTERN AREAS MAY SEE A SLIGHT CHANCE FOR SOME LATE NIGHT POPS
INTO FRIDAY MORNING. CHANCES FOR PRECIPITATION IN THE AREA START TO
INCREASE ON FRIDAY AS FRONT ASSOCIATED WITH NORTHERN ROCKIES
SHORTWAVE SENDS TRAILING PRECIP INTO THE HIGH PLAINS AND MAY
DEVELOP PRECIP SOUTHWARD ALONG THE MID LEVEL FRONT ON THE HIGH
PLAINS. HAVE SPREAD POPS WEST TO EAST THROUGH FRIDAY...CONTINUING
INTO FRIDAY NIGHT AS LLJ VEERS NE OFF THE HIGH PLAINS AGAIN AND
BRINGS A SLIGHTLY HIGHER CHANCE FOR RAIN IN THE OVERNIGHT HOURS.
THIS WAVE PROPAGATES EAST SE THROUGH THE RIDGE AXIS OVER THE STATE
AND AS PROGGED WOULD LINGER STORM CHANCES INTO SATURDAY AFTERNOON.
DEPENDING ON WHERE BOUNDARIES ASSOCIATED WITH THAT SYSTEM REMAIN
AS THE LLJ INCREASES AGAIN EARLY SUNDAY MORNING...WOULD EXPECT
ANOTHER ROUND OF PRECIPITATION SOMEWHERE IN NE KS.
SUN-TUES...PRECIP CHANCES REMAIN SOMEWHAT ERRATIC AND DIFFICULT TO
TIME AS SMALL ROUNDS OF SW ENERGY ROTATE NE OUT OF THE SWRN TROF.
MOISTURE AND INSTABILITY ARE IN PLACE TO RESPOND TO THESE
WAVES...AS WELL AS NIGHTLY CYCLE OF THE LOW LEVEL JET. HAVE PRECIP
THROUGHOUT THE PERIOD WITH HIGHER CHANCES IN THE OVERNIGHT HOURS
AS A RESULT. AS WINDS COME BACK AROUND FROM THE SOUTH...TEMPERATURES
SHOULD WARM BACK TOWARD THE LOWER 80S FOR THE EXTENDED PORTION OF
THE FORECAST PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1136 PM CDT TUE MAY 21 2013
LATEST OBS SHOW SOME MVFR CIGS TO THE NORTH ACROSS NEB. MODELS
CONTINUE TO SHOW THESE CIGS REMAINING JUST NORTH OF THE TERMINALS
WITH THE 00Z OBJECTIVE MOS GUIDANCE KEEPING CONDITIONS VFR.
THEREFORE WILL MAINTAIN PREV VFR FORECAST. THE RAP AND GFS SUGGEST
SOME DECENT MIXING WITH THE POTENTIAL FOR SOME SFC WIND GUSTS
THROUGH THE LATE MORNING AND AFTERNOON ALONG WITH A STRATOCU DECK
FORMING ABOVE 3 KFT.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...65
LONG TERM...67
AVIATION...WOLTERS
AREA FORECAST DISCUSSION...CORRECTED
NWS TOPEKA KS
1149 PM CDT TUE MAY 21 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 339 PM CDT TUE MAY 21 2013
UPPER LOW REMAINS ACROSS THE NORTHERN PLAINS WITH ENERGY ROTATING
AROUND THE BASE MOVING INTO NORTH CENTRAL NEBRASKA. A STRONG
SHORTWAVE WAS MOVING INTO WESTERN OKLAHOMA AT LATE AFTERNOON. MODELS
STILL SHOWING BEST FORCING (Q-VECTOR CONVERGENCE AND VORTICITY
ADVECTION) REMAINING TO THE SOUTH OF THE FORECAST AREA THIS EVENING.
SHORT RANGE HIGH RESOLUTION MODELS BREAK OUT SOME CONVECTION IN FAR
EAST CENTRAL KANSAS EARLY THIS EVENING AND WILL MAINTAIN SMALL
PRECIPITATION CHANCES FOR PARTS OF ANDERSON COUNTY THIS EVENING.
COLD ADVECTION ACROSS NORTHERN KANSAS WILL CONTINUE THROUGH THE
NIGHT WITH TEMPERATURES FALLING INTO THE UPPER 40S IN NORTH CENTRAL
KANSAS TO THE MID 50S IN EAST CENTRAL KANSAS.
CLOUDS WILL BE ON THE DECREASE WEDNESDAY MORNING AND EXPECT SOME
SCATTERED CUMULUS CLOUDS FOR MUCH OF THE AFTERNOON. COOL HIGH
PRESSURE WILL BUILD INTO NORTHEAST KANSAS WEDNESDAY AS THE UPPER
TROUGH MOVES INTO THE GREAT LAKES DURING THE DAY. TEMPERATURES WILL
BE COOLEST ACROSS THE FAR NORTH WITH HIGHS IN THE 60S WITH LOWER 70S
ACROSS THE SOUTH.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 339 PM CDT TUE MAY 21 2013
WED NIGHT THROUGH THU NIGHT...THE UPPER TROUGH IN THE UPPER MS VALLEY
WILL SWING EASTWARD INTO THE GREAT LAKES AS THE HIGH PLAINS UPPER
RIDGE SHIFTS EASTWARD INTO THE EASTERN PLAINS. THIS WILL ALLOW FOR
THE DRY NORTH TO NORTHEASTERLY FLOW THROUGH 850MB TO PERSIST AND
KEEP ANY SIGNIFICANT MOISTURE AND/OR INSTABILITY TO THE SOUTH OF THE
COUNTY WARNING AREA UNTIL LATER THURSDAY NIGHT. THIS WHEN WEAK
THETA E/MOISTURE ADVECTION BEGINS ACROSS THE FAR WEST AND
SOUTHWESTERN PORTIONS OF THE CWA...SO WILL INTRODUCE A SLIGHT CHANCE
FOR THUNDERSTORMS AT THAT TIME. SEASONABLY COOL LOW TEMPERATURES IN
THE UPPER 40S AND LOWER 50S WEDNESDAY NIGHT WILL EDGE UP INTO THE LOW
TO MIDDLE 50S THURSDAY NIGHT WHILE HIGHS ON THURSDAY TOP OUT IN THE
LOW TO MIDDLE 70S.
FRI THROUGH TUESDAY...THE RIDGING ALOFT WILL SLOWLY TRANSLATE
EASTWARD INTO THE MO AND MS VALLEY AREAS OVER THE WEEKEND INTO EARLY
NEXT WEEK. THIS WILL TRANSITION THE FLOW ALOFT TO A MORE WEST AND
SOUTHWESTERLY DIRECTION. THIS WILL ALLOW FOR A LEE SIDE SFC
TROUGH/LOW IN THE CENTRAL HIGH PLAINS TO REMAIN ANCHORED THROUGH THE
PERIOD. AT THE SAME TIME...THE UPPER FLOW WILL LIKELY DIRECT A
SERIES OF WEAK SHORTWAVE TROUGHS OUT OF THE MAIN UPPER TROUGH IN THE
WESTERN CONUS OUT INTO THE CENTRAL PLAINS. MOISTURE RETURN WILL
CONTINUE/REMAIN IN PLACE THROUGH THE PERIOD...SO THE PASSAGE ANY OF
THE SHORTWAVE WILL HAVE THE POTENTIAL TO TRIGGER CONVECTION ACROSS
THE AREA THROUGH THE PERIOD. THIS FAR OUT IT REMAINS VERY DIFFICULT
TO PIN DOWN THE TIMING AND/OR AREAL EXTENT OF ANY CONVECTION AND
MESOSCALE FEATURES SUCH AS OUTFLOW BOUNDARIES FROM POSSIBLE MCS`S
EACH DAY WOULD ONLY COMPLICATE THE FCST. HAVE THEREFORE CONTINUED A
BROAD AND GENERAL FCST ON THE PRECIP POTENTIAL WITH HIGHS GENERALLY
IN THE 80S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1136 PM CDT TUE MAY 21 2013
LATEST OBS SHOW SOME MVFR CIGS TO THE NORTH ACROSS NEB. MODELS
CONTINUE TO SHOW THESE CIGS REMAINING JUST NORTH OF THE TERMINALS
WITH THE 00Z OBJECTIVE MOS GUIDANCE KEEPING CONDITIONS VFR.
THEREFORE WILL MAINTAIN PREV VFR FORECAST. THE RAP AND GFS SUGGEST
SOME DECENT MIXING WITH THE POTENTIAL FOR SOME SFC WIND GUSTS
THROUGH THE LATE MORNING AND AFTERNOON ALONG WITH A STRATOCU DECK
FORMING ABOVE 3 KFT.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...53
LONG TERM...63
AVIATION...WOLTERS
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1136 PM CDT TUE MAY 21 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 339 PM CDT TUE MAY 21 2013
UPPER LOW REMAINS ACROSS THE NORTHERN PLAINS WITH ENERGY ROTATING
AROUND THE BASE MOVING INTO NORTH CENTRAL NEBRASKA. A STRONG
SHORTWAVE WAS MOVING INTO WESTERN OKLAHOMA AT LATE AFTERNOON. MODELS
STILL SHOWING BEST FORCING (Q-VECTOR CONVERGENCE AND VORTICITY
ADVECTION) REMAINING TO THE SOUTH OF THE FORECAST AREA THIS EVENING.
SHORT RANGE HIGH RESOLUTION MODELS BREAK OUT SOME CONVECTION IN FAR
EAST CENTRAL KANSAS EARLY THIS EVENING AND WILL MAINTAIN SMALL
PRECIPITATION CHANCES FOR PARTS OF ANDERSON COUNTY THIS EVENING.
COLD ADVECTION ACROSS NORTHERN KANSAS WILL CONTINUE THROUGH THE
NIGHT WITH TEMPERATURES FALLING INTO THE UPPER 40S IN NORTH CENTRAL
KANSAS TO THE MID 50S IN EAST CENTRAL KANSAS.
CLOUDS WILL BE ON THE DECREASE WEDNESDAY MORNING AND EXPECT SOME
SCATTERED CUMULUS CLOUDS FOR MUCH OF THE AFTERNOON. COOL HIGH
PRESSURE WILL BUILD INTO NORTHEAST KANSAS WEDNESDAY AS THE UPPER
TROUGH MOVES INTO THE GREAT LAKES DURING THE DAY. TEMPERATURES WILL
BE COOLEST ACROSS THE FAR NORTH WITH HIGHS IN THE 60S WITH LOWER 70S
ACROSS THE SOUTH.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 339 PM CDT TUE MAY 21 2013
WED NIGHT THROUGH THU NIGHT...THE UPPER TROUGH IN THE UPPER MS VALLEY
WILL SWING EASTWARD INTO THE GREAT LAKES AS THE HIGH PLAINS UPPER
RIDGE SHIFTS EASTWARD INTO THE EASTERN PLAINS. THIS WILL ALLOW FOR
THE DRY NORTH TO NORTHEASTERLY FLOW THROUGH 850MB TO PERSIST AND
KEEP ANY SIGNIFICANT MOISTURE AND/OR INSTABILITY TO THE SOUTH OF THE
COUNTY WARNING AREA UNTIL LATER THURSDAY NIGHT. THIS WHEN WEAK
THETA E/MOISTURE ADVECTION BEGINS ACROSS THE FAR WEST AND
SOUTHWESTERN PORTIONS OF THE CWA...SO WILL INTRODUCE A SLIGHT CHANCE
FOR THUNDERSTORMS AT THAT TIME. SEASONABLY COOL LOW TEMPERATURES IN
THE UPPER 40S AND LOWER 50S WEDNESDAY NIGHT WILL EDGE UP INTO THE LOW
TO MIDDLE 50S THURSDAY NIGHT WHILE HIGHS ON THURSDAY TOP OUT IN THE
LOW TO MIDDLE 70S.
FRI THROUGH TUESDAY...THE RIDGING ALOFT WILL SLOWLY TRANSLATE
EASTWARD INTO THE MO AND MS VALLEY AREAS OVER THE WEEKEND INTO EARLY
NEXT WEEK. THIS WILL TRANSITION THE FLOW ALOFT TO A MORE WEST AND
SOUTHWESTERLY DIRECTION. THIS WILL ALLOW FOR A LEE SIDE SFC
TROUGH/LOW IN THE CENTRAL HIGH PLAINS TO REMAIN ANCHORED THROUGH THE
PERIOD. AT THE SAME TIME...THE UPPER FLOW WILL LIKELY DIRECT A
SERIES OF WEAK SHORTWAVE TROUGHS OUT OF THE MAIN UPPER TROUGH IN THE
WESTERN CONUS OUT INTO THE CENTRAL PLAINS. MOISTURE RETURN WILL
CONTINUE/REMAIN IN PLACE THROUGH THE PERIOD...SO THE PASSAGE ANY OF
THE SHORTWAVE WILL HAVE THE POTENTIAL TO TRIGGER CONVECTION ACROSS
THE AREA THROUGH THE PERIOD. THIS FAR OUT IT REMAINS VERY DIFFICULT
TO PIN DOWN THE TIMING AND/OR AREAL EXTENT OF ANY CONVECTION AND
MESOSCALE FEATURES SUCH AS OUTFLOW BOUNDARIES FROM POSSIBLE MCS`S
EACH DAY WOULD ONLY COMPLICATE THE FCST. HAVE THEREFORE CONTINUED A
BROAD AND GENERAL FCST ON THE PRECIP POTENTIAL WITH HIGHS GENERALLY
IN THE 80S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1136 PM CDT TUE MAY 21 2013
LATEST OBS SHOW SOME MVFR CIGS TO THE NORTH ACROSS NEB. MODELS
CONTINUE TO SHOW THESE CIGS REMAINING JUST NORTH OF THE TERMINALS
WITH THE 00Z OBJECTIVE MOS GUIDANCE KEEPING CONDITIONS VFR.
THEREFORE WILL MAINTAIN PREV IFR FORECAST. THE RAP AND GFS SUGGEST
SOME DECENT MIXING WITH THE POTENTIAL FOR SOME SFC WIND GUSTS
THROUGH THE LATE MORNING AND AFTERNOON ALONG WITH A STRATOCU DECK
FORMING ABOVE 3 KFT.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...53
LONG TERM...63
AVIATION...WOLTERS
AREA FORECAST DISCUSSION
NWS GRAY ME
1023 PM EDT THU MAY 23 2013
.SYNOPSIS...
A COLD FRONT WILL SLOWLY CROSS THE REGION TONIGHT WILL STALL OFF
THE COAST ON FRIDAY. LOW PRESSURE WILL DEVELOP ON THE FRONT SOUTH
OF CAPE COD FRIDAY NIGHT AND SLOWLY MOVE NORTH THROUGH THE GULF OF
MAINE THROUGH SUNDAY MORNING. LOW PRESSURE WILL CONTINUE NORTH
THROUGH THE MARITIMES SUNDAY NIGHT. HIGH PRESSURE WILL BUILD IN
FROM THE WEST MONDAY AND WILL SHIFT OFFSHORE ON TUESDAY. A WARM
FRONT WILL APPROACH FROM THE SOUTHWEST ON WEDNESDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
UPDATE...
HAVE UPDATED GRIDS BASED ON CURRENT CONDITIONS. RADAR CONTS TO
SHOW AREAS OF SHOWERS AND ISOLD TSTMS OVER THE NRN MTNS WHERE WE
HAVE ISSUED AN AREAL FLOOD ADVISORY. OVER SRN NH...THE ECHOES CONT TO
WEAKEN AS THEY HEAD NORTH...DESPITE A PRECIPITABLE WATER LEVEL
AXIS OF 1.6" OVER THE REGION.
LATEST HRRR RUN CONTS TO SHOW PCPN STREAMING IN FROM THE SOUTH
OVERNIGHT...ALONG AND AHEAD OF APPROACHING COLD FRONT. CATEGORICAL
POPS WILL REMAIN IN THE GRIDS OVERNIGHT WITH PATCHY/AREAS OF FOG.
EXPECT AROUND AN INCH OR SO OF RAINFALL OVER THE COASTAL AREAS
WHICH REMAINS WELL BELOW FLASH FLOOD GUIDANCE.
PREV DISC...
COLD FRONT APPROACHING FROM THE WEST WILL MAKE FOR A WET AND
BREEZY NIGHT ACROSS THE REGION. SCATTERED SHOWERS AND SOME
THUNDERSTORMS WILL GRADUALLY CHANGE TO A WIDESPREAD RAIN OVERNIGHT
AS THE FRONT SLOWLY CROSSES THE AREA. EXPECT THUNDERSTORM ACTIVITY
TO BE MAINLY CONFINED TO NEW HAMPSHIRE LATE THIS AFTERNOON AND
THIS EVENING AS MARINE LAYER PERSISTS ACROSS MOST OF MAINE. CAN`T
RULE OUT A RUMBLE OF THUNDER OVERNIGHT BUT SHOULD BE ISOLATED AND
HAVE NOT INCLUDED THIS IN THE FORECAST AFTER THIS EVENING. EXPECT
OVERNIGHT LOWS TO BE UNIFORM ACROSS THE REGION WITH MOST AREAS
DIPPING INTO THE MID 50S TO NEAR 60.
&&
.SHORT TERM /FRIDAY NIGHT/...
FRONT WILL STALL JUST OFF THE COAST ON FRIDAY WITH RAIN CONTINUING
THROUGH THE DAY ACROSS THE FORECAST AREA. NOT EXPECTING
TEMPERATURES TO MOVE MUCH FROM OVERNIGHT LOWS WITH MOST LOCATIONS
ONLY REACHING THE UPPER 50S TO LOWER 60S. RAIN CONTINUES FRIDAY
NIGHT AS LOW PRESSURE TRACKS NORTH ALONG THE FRONT. FOCUS WILL
TURN TO AREA RIVERS IN NORTHERN ZONES WHERE STORM TOTALS COULD
WILL FALL IN THE THE 2 TO 4 INCH RANGE BY LATE ON SUNDAY.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
CUTOFF AND SFC LOW WILL DRIFT SLOWLY NE THRU THE WEEKEND
CONTINUING PRCP ACROSS THE FCST AREA WITH THE POTENTIAL FOR HEAVY
RAINFALL. MODELS SHOWING MAX QPF ACROSS THE N/MT ZONES TO WRN NH
ZONES. GFS MUCH HIGHER ON QPF...WITH OTHER MODELS PREFERRED. USED
HPC QPF FOR A COMPROMISE. CUTOFF AND SFC LOWS MOVE NE OF THE AREA
MONDAY WITH IMPROVING WX...BUT STILL COOL AIR AND CYCLONIC FLOW
ALOFT ALONG WITH FAIRLY AMPLE RH COULD PRODUCE SOME CLOUDS AND
PSBL -SHRA EVEN ON MONDAY. FOR NOW WILL GO WITH SLGT CHC.
AN UPR LVL AND SFC RIDGE BUILD IN TUESDAY FINALLY BRINGING DRY WX
WITH WARMING TEMPS. AN UPR LVL SHORT WAVE TROF SLIDES E THRU THE
UPR LVL RIDGE LATE WEDNESDAY AND WEDNESDAY NGT...BRINGING ISOLD TO
SCT SHRA TO THE REGION WEDNESDAY NGT AND THURSDAY.
GENERALLY USED BLEND OF GFS40/NAM, MET/MAV & HPC QPF FOR DAYS 4
AND 5 THEN A BLEND OF GFS40, GMOS, MEX/ECE FOR THE REST OF THE
LONG TERM FCST.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
SHORT TERM...IFR/LIFR CEILINGS/VSBY TONIGHT THROUGH FRIDAY.
LONG TERM /SATURDAY THROUGH TUESDAY/...IFR/LIFR SATURDAY THRU MUCH
OF SUNDAY...IMPROVING TO VFR WITH PSBL MVFR ON MONDAY THEN VFR
TUESDAY.
&&
.MARINE...
SHORT TERM...SCA IN EFFECT THROUGH FRIDAY TONIGHT.
LONG TERM /SATURDAY THROUGH TUESDAY/...NE WINDS AHEAD OF
APPROACHING LOW AND SEAS LIKELY AT SCA LEVELS SATURDAY AND MAY
NEED TO EXTEND THE SCA THRU THE DAY. WINDS LET UP AND BACK TO THE
NW SLOWLY SATURDAY NGT THRU MONDAY...LIKELY DROPPING BELOW SCA
LEVELS BY LATE SATURDAY NGT OR EARLY SUNDAY. SEAS WILL BE SLOWER
TO DROP OFF. HIGH PRES PROVIDES RELATIVELY CALMER WINDS AND SEAS
ON TUESDAY.
&&
.FIRE WEATHER...
NO PROBLEMS NOTED.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT SATURDAY FOR ANZ150>154.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
854 PM EDT THU MAY 23 2013
.SYNOPSIS...
A COLD FRONT WILL SLOWLY CROSS THE REGION TONIGHT WILL STALL OFF
THE COAST ON FRIDAY. LOW PRESSURE WILL DEVELOP ON THE FRONT SOUTH
OF CAPE COD FRIDAY NIGHT AND SLOWLY MOVE NORTH THROUGH THE GULF OF
MAINE THROUGH SUNDAY MORNING. LOW PRESSURE WILL CONTINUE NORTH
THROUGH THE MARITIMES SUNDAY NIGHT. HIGH PRESSURE WILL BUILD IN
FROM THE WEST MONDAY AND WILL SHIFT OFFSHORE ON TUESDAY. A WARM
FRONT WILL APPROACH FROM THE SOUTHWEST ON WEDNESDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
UPDATE...
HAVE UPDATED GRIDS BASED ON CURRENT CONDITIONS. RADAR CONTS TO
SHOW AREAS OF SHOWERS AND ISOLD TSTMS OVER THE NRN MTNS WHERE WE
HAVE ISSUED AN AREAL FLOOD ADVISORY. OVER SRN NH...THE ECHOES CONT TO
WEAKEN AS THEY HEAD NORTH...DESPITE A PRECIPITABLE WATER LEVEL
AXIS OF 1.6" OVER THE REGION.
LATEST HRRR RUN CONTS TO SHOW PCPN STREAMING IN FROM THE SOUTH
OVERNIGHT...ALONG AND AHEAD OF APPROACHING COLD FRONT. CATEGORICAL
POPS WILL REMAIN IN THE GRIDS OVERNIGHT WITH PATCHY/AREAS OF FOG.
PREV DISC...
COLD FRONT APPROACHING FROM THE WEST WILL MAKE FOR A WET AND
BREEZY NIGHT ACROSS THE REGION. SCATTERED SHOWERS AND SOME
THUNDERSTORMS WILL GRADUALLY CHANGE TO A WIDESPREAD RAIN OVERNIGHT
AS THE FRONT SLOWLY CROSSES THE AREA. EXPECT THUNDERSTORM ACTIVITY
TO BE MAINLY CONFINED TO NEW HAMPSHIRE LATE THIS AFTERNOON AND
THIS EVENING AS MARINE LAYER PERSISTS ACROSS MOST OF MAINE. CAN`T
RULE OUT A RUMBLE OF THUNDER OVERNIGHT BUT SHOULD BE ISOLATED AND
HAVE NOT INCLUDED THIS IN THE FORECAST AFTER THIS EVENING. EXPECT
OVERNIGHT LOWS TO BE UNIFORM ACROSS THE REGION WITH MOST AREAS
DIPPING INTO THE MID 50S TO NEAR 60.
&&
.SHORT TERM /FRIDAY NIGHT/...
FRONT WILL STALL JUST OFF THE COAST ON FRIDAY WITH RAIN CONTINUING
THROUGH THE DAY ACROSS THE FORECAST AREA. NOT EXPECTING
TEMPERATURES TO MOVE MUCH FROM OVERNIGHT LOWS WITH MOST LOCATIONS
ONLY REACHING THE UPPER 50S TO LOWER 60S. RAIN CONTINUES FRIDAY
NIGHT AS LOW PRESSURE TRACKS NORTH ALONG THE FRONT. FOCUS WILL
TURN TO AREA RIVERS IN NORTHERN ZONES WHERE STORM TOTALS COULD
WILL FALL IN THE THE 2 TO 4 INCH RANGE BY LATE ON SUNDAY.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
CUTOFF AND SFC LOW WILL DRIFT SLOWLY NE THRU THE WEEKEND
CONTINUING PRCP ACROSS THE FCST AREA WITH THE POTENTIAL FOR HEAVY
RAINFALL. MODELS SHOWING MAX QPF ACROSS THE N/MT ZONES TO WRN NH
ZONES. GFS MUCH HIGHER ON QPF...WITH OTHER MODELS PREFERRED. USED
HPC QPF FOR A COMPROMISE. CUTOFF AND SFC LOWS MOVE NE OF THE AREA
MONDAY WITH IMPROVING WX...BUT STILL COOL AIR AND CYCLONIC FLOW
ALOFT ALONG WITH FAIRLY AMPLE RH COULD PRODUCE SOME CLOUDS AND
PSBL -SHRA EVEN ON MONDAY. FOR NOW WILL GO WITH SLGT CHC.
AN UPR LVL AND SFC RIDGE BUILD IN TUESDAY FINALLY BRINGING DRY WX
WITH WARMING TEMPS. AN UPR LVL SHORT WAVE TROF SLIDES E THRU THE
UPR LVL RIDGE LATE WEDNESDAY AND WEDNESDAY NGT...BRINGING ISOLD TO
SCT SHRA TO THE REGION WEDNESDAY NGT AND THURSDAY.
GENERALLY USED BLEND OF GFS40/NAM, MET/MAV & HPC QPF FOR DAYS 4
AND 5 THEN A BLEND OF GFS40, GMOS, MEX/ECE FOR THE REST OF THE
LONG TERM FCST.
&&
.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
SHORT TERM...IFR/LIFR CEILINGS/VSBY TONIGHT THROUGH FRIDAY.
LONG TERM /SATURDAY THROUGH TUESDAY/...IFR/LIFR SATURDAY THRU MUCH
OF SUNDAY...IMPROVING TO VFR WITH PSBL MVFR ON MONDAY THEN VFR
TUESDAY.
&&
.MARINE...
SHORT TERM...SCA IN EFFECT THROUGH FRIDAY TONIGHT.
LONG TERM /SATURDAY THROUGH TUESDAY/...NE WINDS AHEAD OF
APPROACHING LOW AND SEAS LIKELY AT SCA LEVELS SATURDAY AND MAY
NEED TO EXTEND THE SCA THRU THE DAY. WINDS LET UP AND BACK TO THE
NW SLOWLY SATURDAY NGT THRU MONDAY...LIKELY DROPPING BELOW SCA
LEVELS BY LATE SATURDAY NGT OR EARLY SUNDAY. SEAS WILL BE SLOWER
TO DROP OFF. HIGH PRES PROVIDES RELATIVELY CALMER WINDS AND SEAS
ON TUESDAY.
&&
.FIRE WEATHER...
NO PROBLEMS NOTED.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT SATURDAY FOR ANZ150>154.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1009 AM EDT WED MAY 22 2013
.SYNOPSIS...
A WARM FRONT WILL SLOWLY PROGRESS NORTH ACROSS THE REGION TODAY
AND TONIGHT. LOW PRESSURE WILL LIFT TO OUR WEST ON THURSDAY THEN
GRADUALLY PUSH A FRONT ACROSS THE AREA THURSDAY NIGHT INTO FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM UPDATE...12Z KCAR RAOB SHOWS DEEP LAYER MOISTURE PROFILE
THIS MORNING. VISIBLE IMAGERY ALSO SHOWS EXTENSIVE LOW CLOUD
ACROSS THE FA. EXPECT CLOUDY SKIES ACROSS THE REGION TODAY.
CURRENT RADAR IMAGERY DOES SHOW THE LAST OF THE STEADIER SHOWERS
EXITING THE INTERNATIONAL BORDER INTO NEW BRUNSWICK. MADE
ADJUSTMENTS TO POPS FOR TODAY UTILIZING THE RUC13 WHICH WAS DOING A
FAIRLY GOOD JOB AS OF EARLY THIS MORNING. THUS...ONLY EXPECTING
SCATTERED SHOWERS THE BALANCE OF THE DAY. OTHERWISE...ADJUSTED
CURRENT HOURLY TEMPS AND INTERPOLATED TO EXPECTED MAX TEMPS.
A WARM FRONT WILL LIFT NORTH ACROSS THE AREA TONIGHT AS THE LOW
FROM THE GREAT LAKES TRACKS TOWARD WESTERN NEW ENGLAND. SOME
SHOWERS WILL OCCUR ALONG THE FRONT MAINLY ACROSS THE FAR NORTH. AN
EMBEDDED RUMBLE OF THUNDER CAN`T BE RULED OUT. HUMID AIR WILL
LIKELY RESULT IN SOME FOG IN MANY AREAS WEDNESDAY NIGHT.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AN ACTIVE AND UNSETTLED PATTERN WILL CONTINUE TO UNFOLD...
LOW PRESSURE AND AN ASSOCIATED FRONTAL BOUNDARY LIFT NORTH EARLY
THURSDAY WITH THE AREA BREAKING INTO A WARMER AND MORE HUMID AIR
MASS. NOT EXPECTING MUCH IN THE WAY OF PRECIP IN THE MORNING
HOWEVER IN THE AFTERNOON EXPECT SHOWERS AND THUNDERSTORMS TO
DEVELOP OVER NW PORTIONS OF THE CWA ALONG AND AHEAD OF THE FRONT
AS IT BEGINS TO COLLAPSE BACK TO THE SOUTH AND EAST. MODELS DEPICT
CAPE VALUES OVER NW AREAS GENERALLY AROUND 500 TO 1000 J/KG BUT THERE
IS CONCERN AS SHEAR VALUES LOOK TO BE QUITE STRONG, IN EXCESS OF
40 KNOTS FROM 0-6 KM, WHICH COULD RESULT IN ORGANIZED STRONGER
STORMS DEVELOPING. PWAT VALUES NEAR 1.50 INCHES ALONG A FAIRLY
DEEP WARM CLOUD LAYER AND SLOW STORM MOTION VECTORS SUGGEST HEAVY
RAINFALL WILL BE THE BIGGEST THREAT BUT STRONG WINDS WILL ALSO BE POSSIBLE.
HAVE ADDED ENHANCED WORDING MENTIONING HEAVY RAINFALL IN THE GRIDS
WITH AGAIN, THE BIGGEST CONCERN LOOKING TO BE OVER ROUGHLY THE
NORTHWESTERN THIRD OF THE CWA. SHOWERS/STORMS WILL CONTINUE TO
SHIFT SOUTH AND EAST WITH THE FRONT THURSDAY NIGHT WHILE GENERALLY
WEAKENING WITH TIME. GUIDANCE CONTINUES TO DEPICT THIS FRONT
GETTING HUNG UP AS IT NEARS THE COAST HEADING INTO FRIDAY. THIS
WILL KEEP PERIODS OF RAIN AND SHOWERS GOING RIGHT THROUGH FRIDAY
WITH THE HEAVIEST AND STEADIEST PRECIPITATION SHIFTING TO SOUTHERN
AND EASTERN AREAS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE GFS AND ECMWF HAVE COME INTO LINE BOTH DEPICTING LOW PRESSURE
DEVELOPING ALONG THE STALLED FRONT AND PUSHING NORTH FRIDAY NIGHT
INTO SATURDAY. THIS WILL RESULT IN CONTINUING RAINFALL THROUGH
SATURDAY WITH ADDITIONAL AMOUNTS OF A HALF INCH TO AN INCH
POSSIBLE BY LATE SATURDAY. WITH THE LOW LOOKING TO TRACK EAST OF
THE AREA THIS WILL KEEP THE AREA ON THE COOL SIDE OF THE SYSTEM
WITH NORTHERLY WINDS AND TEMPERATURES STRUGGLING TO MAKE IT OUT OF
THE UPPER 40S AND LOW 50S FOR SATURDAY. THE PICTURE BECOMES EVEN MORE
COMPLEX FOR SATURDAY NIGHT AS COLD AIR CONTINUES TO BE DRAWN
SOUTH. THIS COULD POTENTIALLY RESULT IN RAIN CHANGING TO SOME WET
SNOW OVER HIGHER ELEVATIONS SATURDAY BEFORE PRECIPITATION WINDS
DOWN TO SHOWERS HEADING INTO SUNDAY. TEMPERATURES REMAIN VERY COOL
FOR SUNDAY...ONLY REACHING THE LOW TO MID 50S AT BEST.
EXPECT SLOW IMPROVEMENT HEADING INTO EARLY NEXT WEEK. THE
LINGERING UPPER TROUGH WILL RESULT IN PERSISTING CLOUDS, COOL
TEMPERATURES, AND THE CHANCE OF SHOWERS MONDAY WITH WARMER DRIER
WEATHER EXPECTED BY TUESDAY.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: IFR CONDITIONS ARE EXPECTED IN LOW CLOUDS AND AREAS OF
FOG TODAY AND TONIGHT ALTHOUGH CONDITIONS MAY BRIEFLY IMPROVE TO
MVFR AT TIMES ACROSS THE NORTH DURING THE MIDDAY TODAY.
SHORT TERM:
EXPECT MVFR/IFR PERSISTING THURSDAY IN THE SOUTH DUE TO MARINE
FOG AND STRATUS. NORTHERN SITES SHOULD SEE SOME BRIEF IMPROVEMENT
DURING THE DAY BEFORE SHOWERS AND STORMS BRING A RETURN TO MVFR
AND EVENTUALLY IFR BY LATE DAY. EXPECT PREDOMINATELY MVFR AND IFR
CONDITIONS REGION WIDE THURSDAY NIGHT THROUGH SATURDAY DUE TO
CONTINUING PERIODS OF RAIN AND SHOWERS. SOME IMPROVEMENT WILL BE
POSSIBLE SUNDAY AS STEADIER PRECIPITATION WINDS DOWN.
&&
.MARINE...
NEAR TERM: WINDS AND SEAS WILL BE BELOW SCA TODAY AND TONIGHT.
HUMID AIR MOVING IN OVER THE COLDER WATERS WILL LIKELY RESULT IN
AREAS OF FOG THROUGH TONIGHT.
SHORT TERM:
WINDS/SEAS BUILD THURSDAY WITH SCA CONDITIONS EXPECTED BY THE
AFTERNOON CONTINUING THROUGH FRIDAY MORNING. ALSO EXPECT AREAS OF
FOG DURING THIS PERIOD REDUCING VISIBILITIES ALONG WITH PERIODS OF RAIN
AND SHOWERS. WINDS/SEAS MAY BRIEFLY DIMINISH LATE FRIDAY BEFORE
INCREASING ONCE AGAIN SATURDAY AS LOW PRESSURE MOVES NORTH.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON THURSDAY TO NOON EDT FRIDAY FOR
ANZ050>052.
&&
$$
NEAR TERM...BLOOMER/DUDA
SHORT TERM...FITZSIMMONS
LONG TERM...FITZSIMMONS
AVIATION...BLOOMER/DUDA/FITZSIMMONS
MARINE...BLOOMER/DUDA/FITZSIMMONS
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
656 AM EDT WED MAY 22 2013
.SYNOPSIS...
A WARM FRONT WILL REMAIN STALLED ACROSS NEW HAMPSHIRE AND MAINE
TODAY...LIFTING NORTH OF THE REGION TONIGHT. A COLD FRONT WILL
SLOWLY APPROACH FROM THE NORTHWEST THURSDAY PUSH OFFSHORE FRIDAY.
LOW PRESSURE WILL DEVELOP ALONG THE FRONT SOUTH OF NEW ENGLAND
FRIDAY NIGHT AND STRENGTHEN IN THE GULF OF MAINE ON SATURDAY,
MOVING INTO THE CANADIAN MARITIMES ON SUNDAY, WITH COOLER THAN
NORMAL TEMPERATURES EXPECTED FRIDAY THROUGH SUNDAY. ON MEMORIAL
DAY AND TUESDAY HIGH PRESSURE WILL NUDGE THE LOW NORTHWARD WITH
SEASONABLY WARM TEMPERATURES RETURNING TO NORTHERN NEW ENGLAND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
.UPDATE...
NOT MUCH TO CHANGE FOR THIS UPDATE AS POPS ARE ON TRACK. AREA OF
RAIN NOW MOVING INTO EASTERN MAINE AND OFFSHORE. HRRR HAS HAD A
GOOD HANDLE ON THE EVOLUTION OF THIS RAIN EVENT. WE SHOULD HAVE A
BREAK THROUGH THE MORNING BEFORE RAIN RETURNS THIS AFTERNOON.
&&
PREVIOUS DISCUSSION...
LIGHT TO MODERATE RAIN IS NOW MOVING OVER NORTHERN NEW ENGLAND
WITH A RAIN FREE AREA IMMEDIATELY BEHIND IT. FARTHER SOUTH
CONVECTION IS HEAVIER AND STILL MOVING ACROSS PORTSMOUTH WITH
MORE TO THE SOUTH AND WEST. WHEN THE RAIN DOES SUBSIDE PATCHY
DENSE FOG MAY FORM LATER THIS MORNING. MOST THUNDER IS TO OUR
SOUTH HOWEVER HAVE KEPT ISOLATED STRIKES IN THE FORECAST THIS
MORNING. A WARM FRONT IS THE FOCUS OF THE HEAVIER PRECIPITATION
AND STRETCHES THROUGH SOUTHERN NY STATE AND OVER LONG ISLAND
SOUND.
MOST OF THE PRECIPITATION WITH THIS BATCH WILL EXIT BY LATE
MORNING. WE WILL ONLY SEE A FEW HOURS MOSTLY FREE OF PRECIPITATION
AS THE WARM FRONT LIFTS NORTH AND LOW PRESSURE OVER THE GREAT
LAKES MOVES NORTHEAST ALONG IT. IN ADDITION DIURNAL HEATING AND
MUCAPES AOA 1000 J/KG THIS AFTERNOON WILL TRIGGER THUNDERSTORMS.
THAT SAID...SEVERE WEATHER IS NOT EXPECTED.
TEMPERATURES TODAY WILL DEPEND ON THE EASTWARD PROGRESSION OF THE
WARM FRONT. READINGS WILL RANGE FROM THE UPPER 50S NEAR JACKMAN AND
WATERVILLE TO 70S OVER MUCH OF NH AND FAR WESTERN MAINE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
RAIN CONTINUES TONIGHT INTO THE OVERNIGHT HOURS. THE WARM FRONT
WILL LIFT INTO CANADA BY TOMORROW AFTERNOON PLACING THE ENTIRETY
OF NH AND WESTERN MAINE IN THE WARM SECTOR. A NNE TO SSW ORIENTED
COLD FRONT WILL ARRIVE FROM THE WEST LATE IN THE DAY THURSDAY
HELPING TO GENERATE MODERATE RAIN AND ADDITIONAL THUNDERSTORMS.
AFTER WARM OVERNIGHT LOWS...ALMOST THE ENTIRE REGION SHOULD WARM
INTO THE 70S THURSDAY.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
THE SURFACE COLD FRONT APPROACHES FROM THE WEST THURSDAY NIGHT BUT
WILL BE SLOWED BY A STRENGTHENING SURFACE LOW FORECAST TO RIDE
NORTH UP THE ATLANTIC SEABOARD THURSDAY NIGHT INTO FRIDAY AND
SATURDAY. EXPECTEDLY, THE FORECAST MODELS ARE BICKERING ABOUT THE
STRENGTH OF THIS LOW, WHICH WILL ULTIMATELY DETERMINE HOW RAPIDLY
THE WET WEATHER WILL EXIT EASTERN NEW ENGLAND. THE GFS CONTINUES
TO BE BY FAR THE MOST AGGRESSIVE WITH THIS LOW -- CLOSING OFF A
1001 HPA LOW IN THE BAY OF FUNDY SATURDAY NIGHT. WPC HAS CONTINUED
TO FAVOR THE CONSISTENT AND WEAKER ECMWF SOLUTION, AND WE`VE
FOLLOWED THAT THINKING AS WELL HERE. THIS TRANSLATES TO DRYING OUT
ON SATURDAY INTO SUNDAY, WITH DRY WEATHER CONTINUING INTO EARLY
NEXT WEEK.
AGREEMENT DOES, HOWEVER, COME IN THE UNSEASONABLY COOL UPPER
LEVEL TROUGH OVER THE NORTHEASTERN STATES THROUGH ABOUT SUNDAY
BEFORE FILLING AND MOVING OFFSHORE EARLY NEXT WEEK. MAX
TEMPERATURES FOR FRIDAY AND SATURDAY WILL RUN SOME 10-15F BELOW
NORMAL FOR LATE MAY -- MAKING IT FEEL MORE LIKE PATRIOT`S DAY THAN
MEMORIAL DAY WEEKEND. EVENTUALLY BY THE BEGINNING OF NEXT WEEK A
RETURN TO MORE SEASONABLY WARM TEMPERATURES WILL RETURN.
&&
.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM...LIFR/IFR CONDITIONS TODAY IN FOG/DRIZZLE/SHOWERS/
STRATUS. SOME IMPROVEMENT TO MVFR IN BETWEEN PERIODS OF RAIN.
DETERIORATING CONDITIONS EXPECTED AGAIN TONIGHT.
LONG TERM...MVFR/IFR CONDITIONS THURSDAY NIGHT WILL PERSIST
THROUGH FRIDAY AND GRADUALLY GIVE WAY TO VFR CLEAR CONDITIONS BY
SUNDAY.
&&
.MARINE...
SHORT TERM...A SMALL CRAFT HAS BEEN ISSUED BEGINNING THURSDAY AT
NOON AND LASTING THROUGH FRIDAY. OTHERWISE FOG...DRIZZLE...AND
SHOWERS ARE EXPECTED TO SIGNIFICANTLY REDUCE VISIBILITIES.
LONG TERM...WITH THE FRONT/SURFACE LOW IN THE GULF OF MAINE INTO
THE WEEKEND, EXPECT SMALL CRAFT ADVISORY CONDITIONS IN THE COASTAL
WATERS TO EXTEND AT LEAST INTO FRIDAY AND SATURDAY.
&&
.FIRE WEATHER...
NO ISSUES ANTICIPATED THE REMAINDER OF THIS WEEK DUE TO WET
CONDITIONS.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON THURSDAY TO NOON EDT FRIDAY FOR
ANZ150>154.
&&
$$
SHORT TERM...HANES
LONG TERM...STJEAN
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
212 PM EDT WED MAY 22 2013
.SYNOPSIS...
UPPER LEVEL IMPULSES BRINGS AN INCREASE IN SHOWERS AND
THUNDERSTORMS THROUGH THURSDAY NIGHT...UNTIL A COLD FRONT CROSSES. MUCH
COOLER WEATHER IS FORECAST THIS HOLIDAY WEEKEND UNDER HIGH
PRESSURE.
&&
.NEAR TERM /THROUGH THURSDAY/...
DAYTIME HEATING CONTINUES TO PUSH OUR TEMPERATURES CLOSE TO THE
CONVECTIVE THRESHOLD. 16Z MESOANALYSIS ILLUSTRATES NO CINH LEFT
AND EQUIV POTENTIAL TEMPS BUILDING. STILL A FAIR AMOUNT OF UNCERTAINTY
WITH THE DEVELOPMENT OF STORMS AND HOW STRONG STORMS WILL BE
LATER TODAY AND TONIGHT. LATEST THINKING IS STORMS WILL DEVELOP
ALONG THE THETA-E RIDGE AXIS WHICH IS BUILDING ACROSS WV AND WRN
PA. TERRAIN INDUCED STORMS ARE ALREADY UNDERWAY OVER THE CENTRAL
MTNS OF WV. FARTHER W ACROSS OHIO...NOT SURE HOW MUCH DEVELOPMENT
WILL OCCUR THIS AFTERNOON UNTIL S/W TROUGH PASSES AROUND 0Z.
LIKELY POPS STILL ARE ON TRACK FOR THIS EVENING FOR THE ENTIRE
AREA. IF THE LATEST HRRR IS CORRECT WE COULD SEE SOME LOCALIZED
HIGH WATER POTENTIAL OVER NRN WV WITH TRAINING OF STORMS.
AFTER MIDNIGHT THINGS SHOULD QUIET DOWN AS LLVLS STABILIZE AND WE
AWAIT MAIN TROF AXIS TO TRAVERSE FROM THE WEST. NAM AND GFS AGREE
ON A PERIOD OF DRY OR ISOLD ACTIVITY TMRW FROM LATE MRNG THROUGH
MID AFTERNOON BEFORE UPPER LEVEL IMPULSES CROSS. DO NOT FORESEE A
SEVERE WEATHER THREAT THURSDAY DUE TO LACK OF HEATING AS AN
ABUNDANCE OF CLOUDS WILL BE PRESENCE KEEPING THERMODYNAMICS LOW.
GREATEST CHALLENGE IS IF NAM SCENARIO OF A BATCH OF TSTMS RIDING
NE FROM WV INTO SWRN PA AROUND DAYBREAK MATERIALIZES. FOR
NOW...HELD OFF IN FAVOR OF CONTINUITY PER LOW CONFIDENCE ON THIS
OUTCOME. 98
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
A RAPID TRANSITION TO MUCH COLDER CONDITIONS TAKES PLACE DURING
THIS PERIOD AS THE CONSENSUS OF THE MORE RELIABLE GLOBAL MODEL
SYSTEMS SUGGESTING THE MID-LEVEL SYSTEM TRACKING THROUGH THE
REGION SHOULD CLOSE OFF AS IT MOVES OVER PITTSBURGH AND SLOWLY
OOZES SOUTHEASTWARD. THE CLOSED SOLUTIONS FAVORED BY THE MORE
RELIABLE MODELS END UP TRENDING TOWARD THE SLOWER END OF THE
GUIDANCE PACK WITH THIS SYSTEM...WHICH MAKES SENSE GIVEN THE
HIGHER LONG WAVE AMPLITUDE. AS SUCH...THE SYSTEMS DEPARTURE WAS
SLOWED IN THE FORECAST WHICH RESULTED IN INCREASING POPS INTO
FRIDAY.
WHILE ITS DEPARTURE IS SLOWER...MUCH DRIER AIR DOES WORK INTO THE
AREA BY FRIDAY NIGHT WITH THE CONSENSUS OFFERING EXTREMELY LEAN
LAYER RH PROFILES AND WEAKENING NORTHWEST COLD ADVECTION. THIS
SETS THE STAGE FOR STELLAR RADIATIONAL COOLING GOING INTO SATURDAY
MORNING. GRIDDED GUIDANCE SUGGESTS WIDESPREAD 30S ACROSS THE
AREA...WHICH WITH 850 MB TEMPERATURES FALLING TOWARD -2C IS NOT TOO
SHOCKING. FROST WAS ADDED TO THE GRID TO ACCOMMODATE LOWS
GENERALLY IN THE MID 30S ACROSS VAST TRACTS OF THE CWA...AND
FROST/FREEZE HEADLINES SEEM POSSIBLE AT THIS POINT. THESE
TEMPERATURES AT 850 MB FAIL TO MODERATE DURING THE DAY SATURDAY
MUCH...SO TEMPERATURES WILL LIKELY ONLY WANDER FOR HIGHS FROM THE
UPPER 50S FRIDAY TOWARD THE LOWER 60S SATURDAY. FRIES
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
SIMILAR CONDITIONS PERSIST THROUGH THE REST OF THE WEEKEND AND
EVEN POSSIBLY INTO MONDAY MORNING WITH VERY DRY CONDITIONS AND
LIGHT WINDS FAVORING SUPERIOR RADIATIONAL COOLING EACH NIGHT. AS
SUCH...LOWS CONTINUE TO LOOK TO HEAD TOWARD THE 30S EACH
NIGHT...WITH A FEW LOCATIONS INEVITABLY DROPPING BELOW FREEZING.
ONCE AGAIN...FROST WAS ADDED TO THE FORECAST INTO THE
OVERNIGHT/EARLY MORNINGS THIS WEEKEND...AND FROST/FREEZE HEADLINES
AGAIN SEEM QUITE POSSIBLE.
OTHERWISE...VERY GRADUAL MODERATION OF LOW LEVEL TEMPERATURES WILL
BE LIKELY AS THE CLOSED SYSTEM DEPARTS EASTWARD BUT DRY CYCLONIC
NORTHWESTERLY FLOW ALOFT REMAINS THE LARGE CONTROLLING FACTOR FOR
OUR WEATHER. THIS IS THANKS IN PART TO THE FACT THAT THE MODEL
CONSENSUS KEEPS THE LARGE SCALE RIDGE AXIS LARGELY TO OUR WEST
THROUGH THE MIDDLE OF NEXT WEEK. AS A RESULT...CONDITIONS SHOULD
REMAIN GENERALLY DRY WITH VERY SLOW MODERATION OF TEMPERATURES
THROUGH THE WEEK. FRIES
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
LOW TO MEDIUM CONFIDENCE FORECAST ON SHOWER AND THUNDERSTORM TIMING.
VFR WEATHER WILL PREVAIL MUCH OF THE FCST PERIOD /AT LEAST INTO
THE OVERNIGHT HOURS/...THE CHALLENGE IS TIMING ON ANY SHRA OR TSRA
IMPACTING THE TERMINALS. MAINTAINED VCTS FOR LATE AFTERNOON AND
EVENING BEFORE TRANSITIONING TO VFR SHRA UNTIL MIDNIGHT. CLOUDS
WILL DEVELOP IN THE PREDAWN HOURS...LATEST GUIDANCE SUGGEST CIGS
IN THE 015-025 WHICH IS HIGHER THAN EARLIER RUNS AND IN LINE WITH
ONGOING FORECAST. STRATOCU WILL LIFT BY MID MRNG INTO A LOW END
VFR DECK. FOR PLACES THAT EXPERIENCE RAINFALL...PATCHY FOG COULD
DEVELOP DURING THE PREDAWN HOURS. 98
.OUTLOOK.../THURSDAY THROUGH SUNDAY/...
THE PROBABILITY OF WIDESPREAD IFR WEATHER IS LOW.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
117 PM EDT WED MAY 22 2013
.SYNOPSIS...
UPPER LEVEL IMPULSES BRINGS AN INCREASE IN SHOWERS AND
THUNDERSTORMS THROUGH THURSDAY NIGHT...UNTIL A COLD FRONT CROSSES. MUCH
COOLER WEATHER IS FORECAST THIS HOLIDAY WEEKEND UNDER HIGH
PRESSURE.
&&
.NEAR TERM /THROUGH THURSDAY/...
DAYTIME HEATING CONTINUES TO PUSH OUR TEMPERATURES CLOSE TO THE
CONVECTIVE THRESHOLD. 16Z MESOANALYSIS ILLUSTRATES NO CINH LEFT
AND EQUIV POTENTIAL TEMPS BUILDING. STILL A FAIR AMOUNT OF UNCERTAINTY
WITH THE DEVELOPMENT OF STORMS AND HOW STRONG STORMS WILL BE
LATER TODAY AND TONIGHT. LATEST THINKING IS STORMS WILL DEVELOP
ALONG THE THETA-E RIDGE AXIS WHICH IS BUILDING ACROSS WV AND WRN
PA. TERRAIN INDUCED STORMS ARE ALREADY UNDERWAY OVER THE CENTRAL
MTNS OF WV. FARTHER W ACROSS OHIO...NOT SURE HOW MUCH DEVELOPMENT
WILL OCCUR THIS AFTERNOON UNTIL S/W TROUGH PASSES AROUND 0Z.
LIKELY POPS STILL ARE ON TRACK FOR THIS EVENING FOR THE ENTIRE
AREA. IF THE LATEST HRRR IS CORRECT WE COULD SEE SOME LOCALIZED
HIGH WATER POTENTIAL OVER NRN WV WITH TRAINING OF STORMS.
AFTER MIDNIGHT THINGS SHOULD QUIET DOWN AS LLVLS STABILIZE AND WE
AWAIT MAIN TROF AXIS TO TRAVERSE FROM THE WEST. NAM AND GFS AGREE
ON A PERIOD OF DRY OR ISOLD ACTIVITY TMRW FROM LATE MRNG THROUGH
MID AFTERNOON BEFORE UPPER LEVEL IMPULSES CROSS. DO NOT FORESEE A
SEVERE WEATHER THREAT THURSDAY DUE TO LACK OF HEATING AS AN
ABUNDANCE OF CLOUDS WILL BE PRESENCE KEEPING THERMODYNAMICS LOW.
GREATEST CHALLENGE IS IF NAM SCENARIO OF A BATCH OF TSTMS RIDING
NE FROM WV INTO SWRN PA AROUND DAYBREAK MATERIALIZES. FOR
NOW...HELD OFF IN FAVOR OF CONTINUITY PER LOW CONFIDENCE ON THIS
OUTCOME.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY/...
A REINFORCING FRONT IS PROGGED FOR FRIDAY WITH RESIDUAL SHWR CHCS
FADING BY AFTN WITH PASSAGE OF THAT FEATURE. AS NW FLOW DVLPS WITH
PASSAGE OF THE AFOREMENTIONED PHASED TROF AXIS...COLD ADVCTN WL
LIMIT TEMP RECOVERY. EXPECT HIGHS ABOUT 10 DEGREES BELOW THE
SEASONAL AVERAGES UNDR THE RESULTING HIGH AMPLITUDE...ERN CONUS
TROF PTN.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE MODELS ARE IN GOOD AGREEMENT ON THE OVERALL UPPER LEVEL PATTERN
THROUGH THE EXTENDED WITH AN UPPER LEVEL RIDGING OF THE CENTRAL
CONUS AND TROUGHING IN BOTH THE WEST AND EAST. WHILE THIS WOULD
GENERALLY LEAD TO A MUCH LESS THAN CONFIDENT FORECAST IN THE
SHORTWAVES WITHIN THE FLOW...THIS DOESN`T SEEM TO BE THE CASE AS
BOTH THE GFS AND ECMWF SUGGEST THAT MUCH OF THE PRECIPITATION WILL
BE SUPPRESSED SOUTH OF THE REGION THROUGH MUCH OF THE PERIOD.
THUS...OPTED TO TAKE A BLEND OF THE MODELS AND HPC
GUIDANCE. ALSO...HEDGED A BIT COOLER WITH TEMPERATURES WITH
NORTHWEST FLOW PRESENT ESPECIALLY FOR THE FIRST HALF OF THE
PERIOD. THIS KEPT TEMPERATURES BELOW SEASONAL AVERAGES SAT/SUN
BEFORE MODERATING CLOSER TO NORMAL FOR THE REST OF THE PERIOD.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
LOW TO MEDIUM CONFIDENCE FORECAST ON SHOWER AND THUNDERSTORM TIMING.
VFR WEATHER WILL PREVAIL MUCH OF THE FCST PERIOD /AT LEAST INTO
THE OVERNIGHT HOURS/...THE CHALLENGE IS TIMING ON ANY SHRA OR TSRA
IMPACTING THE TERMINALS. MAINTAINED VCTS FOR LATE AFTERNOON AND
EVENING BEFORE TRANSITIONING TO VFR SHRA UNTIL MIDNIGHT. CLOUDS
WILL DEVELOP IN THE PREDAWN HOURS...LATEST GUIDANCE SUGGEST CIGS
IN THE 015-025 WHICH IS HIGHER THAN EARLIER RUNS AND IN LINE WITH
ONGOING FORECAST. STRATOCU WILL LIFT BY MID MRNG INTO A LOW END
VFR DECK. FOR PLACES THAT EXPERIENCE RAINFALL...PATCHY FOG COULD
DEVELOP DURING THE PREDAWN HOURS.
.OUTLOOK.../THURSDAY THROUGH SUNDAY/...
THE PROBABILITY OF WIDESPREAD IFR WEATHER IS LOW.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
SYNOPSIS...98
NEAR TERM...98
SHORT TERM...15
AVIATION...98
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1005 AM EDT WED MAY 22 2013
.SYNOPSIS...
HIGH PRESSURE PERSISTING OVER THE ATLANTIC WITH WARM AND HUMID
CONDITIONS UNTIL A COLD FRONT THURSDAY NIGHT. AN UPPER TROUGH
WILL LINGER OVER THE AREA FRIDAY WITH HIGH PRESSURE BUILDING
THROUGH SATURDAY. A FRONTAL BOUNDARY STALLS OUT ACROSS THE MID-
ATLANTIC SUNDAY NIGHT THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE BOTH AT THE UPPER-LEVELS AND THE SURFACE WILL REMAIN
OVER THE ATLANTIC OCEAN THROUGH TONIGHT. AN UPPER-LEVEL TROUGH WILL
SLOWLY SHIFT FROM THE CENTRAL CONUS INTO THE GREAT LAKES. A
SOUTHERLY FLOW AROUND THE HIGH WILL CONTINUE TO USHER IN WARM AND
HUMID CONDITIONS ACROSS OUR AREA.
LOW CLDS AND FOG ASSOCD WITH THE NOCTURNAL INVERSION LESS
PRONOUNCED THAN YDA...AND ITS BURNING AWAY QUICKER. THEREFORE...
THERE SHUD BE LESS OF A MAXT SPREAD THAN THERE WAS YDA. STILL...HV
TWEAKED I-95 CRRDR DOWN A DEGF OR TWO TO ACCNT FOR ITS IMPACT.
THE WARM AND HUMID AIRMASS IN PLACE WILL LEAD TO HIGH AMOUNTS OF
INSTABILITY. UNMODIFIED LWX RAOB REFLECTS THIS...BUT ALSO
HIGHLIGHTS THE CAPPING INHIBITION BTWN H9-8. HGTS SHUD BE DROPPING
TAFTN AS TROF AXIS CROSSES THE WRN GRTLKS. MODIFYING THE SNDG FOR
T/TD 88/68 YIELDS ARND 3000 J/KG OF SBCAPE W/O A CAP. MLCAPE MUCH
MORE RESERVED AND SLGTLY INHIBITED.
TERRAIN CIRCULATIONS AND A SURFACE TROUGH WILL ACT AS LIFTING
MECHANISMS FOR CONVECTION THIS AFTERNOON. THIS IS ALSO SIMILAR TO
TUESDAY. THEREFORE...A BETTER CHANCE FOR THUNDERSTORMS EXISTS THIS
AFTERNOON AND EVENING...ESPECIALLY NEAR AND WEST OF THE I-95
CORRIDOR. HV ADJUSTED POPS SLGTLY TO PLACE MORE EMPHASIS ON
APLCHNS AND DEEMPHASIZE INVOF CHESPK BAY. HRRR /WRF-ARW4 BOTH
SUGGEST THAT TSRA SHUD FIRE TAFTN W OF THE BLURDG...SPCLY AFTR
18Z. WL NEED TO WATCH THAT TIMING THO...AS RADAR TRENDS IN WVA
ATTM SUGGEST IT MAY BE ERLR.
ALTHOUGH WIDESPREAD SEVERE WEATHER WILL LIKELY HOLD OFF TO OUR
WEST FOR LOCATIONS CLOSER TO THE UPPER-LEVEL TROUGH...THERE IS A
THREAT FOR LOCALLY DAMAGING WIND GUSTS AND LARGE HAIL IN ANY
THUNDERSTORMS THAT DO DEVELOP DUE TO THE HIGH INSTABILITY.
CONVECTION WILL LIKELY DISSIPATE LATER THIS EVENING DUE TO THE LOSS
OF DAYTIME HEATING. HOWEVER...AN UPPER-LEVEL DISTURBANCE IS EXPECTED
TO PASS THROUGH THE REGION LATE TONIGHT AS THE UPPER-LEVEL TROUGH
CONTINUES TO SLIDE CLOSER TO OUR AREA. PLENTY OF MOISTURE AND
FORCING FROM THE UPPER-LEVEL DISTURBANCE MAY RESULT IN SCATTERED
SHOWERS/T-STORMS TOWARD MORNING. MIN TEMPS TONIGHT WILL RANGE FROM
THE 50S IN THE MOUNTAINS TO THE LOWER AND MIDDLE 70S IN DOWNTOWN
WASHINGTON/BALTIMORE.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
THURSDAY LOOKS TO BE THE LAST ABOVE NORMAL TEMPERATURE DAY FOR
AWHILE AHEAD OF THE COLD FRONT THAT CROSSES THURSDAY NIGHT
TIMEFRAME. PREFRONTAL LINES/CLUSTERS OF SHOWERS/THUNDERSTORMS
PROGRESS EAST ACROSS THE AREA THURSDAY INTO THURSDAY NIGHT. GFS BUFR
SNDG FOR KIAD PROGS A 1.6 INCH PWAT WHICH IS CERTAINLY HIGH...BUT
JUST SHY OF THE 2 STDEV INDICATOR OF FLASH FLOODING. WITH
PROGRESSIVE NATURE OF THE ACTIVITY...ANY FLASH FLOODING WOULD BE
LOCALIZED. DAMAGING WIND THREAT...PARTICULARLY WITH HEATING ON
THURSDAY IS ABLE TO PEAK BEFORE ORGANIZED ACTIVITY MOVES THROUGH.
FRIDAY...UPR TROUGH DRIFTS EAST OVER THE AREA WITH BACK EDGE OF
CLOUDS SLOW TO COME IN THE AFTERNOON. GUSTY NWLY FLOW FRIDAY
CONTINUES AS HIGH PRESSURE BUILDS THROUGH SATURDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
SHORTWAVE FROM TN VLY ON SUNDAY NOW LOOKS TO EXPAND EAST ACROSS THE
SOUTHERN-CENTRAL MID-ATLANTIC. CONVERGENCE ALONG THIS BOUNDARY WOULD
SET OFF SHOWERS. PATTERN IS STALLED INTO MID NEXT WEEK...SO A
PROLONGED CLOUDY/RAINY PERIOD IS POSSIBLE. THIS WOULD RESULT IN
BELOW NORMAL TEMPS.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
LOW CLOUDS BURNING OFF ATTM. MVFR AT DCA/MTN...BUT ANTICIPATE VFR
EVERYWHERE BY 15Z.
SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP AFTN...PRIMARILY
INVOF MRB. SOME OF THE THUNDERSTORMS WILL BE CAPABLE OF PRODUCING
GUSTY WINDS AND LARGE HAIL. AREAS OF LOW CLOUDS ARE POSSIBLE LATE
TONIGHT ALONG WITH SCATTERED SHOWERS/T-STORMS.
THUNDERSTORMS THURSDAY INTO THURSDAY EVENING AHEAD OF A COLD FRONT.
IFR CONDS POSSIBLE IN THE HEAVIEST ACTIVITY. SLY FLOW UNTIL A COLD
FROPA THURSDAY NIGHT. NWLY FLOW WITH GUSTS 25 TO POSSIBLY 30 KT WITH
MID LEVEL CIGS FRIDAY. NWLY FLOW CONTINUES THROUGH SATURDAY AS HIGH
PRESSURE BUILDS.
&&
.MARINE...
HIGH PRESSURE WILL REMAIN OVER THE ATLANTIC OCEAN THROUGH TONIGHT. A
SOUTHERLY FLOW WILL CONTINUE OVER THE WATERS DURING THIS TIME. A
SMALL CRAFT ADVISORY REMAINSS IN EFFECT FOR PORTIONS OF THE WATERS
THROUGH TONIGHT. SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE
LATER THIS AFTERNOON AND EVENING. ANY THUNDERSTORMS THAT DO
DEVELOP WILL BE CAPABLE OF PRODUCING GUSTY WINDS AND HAIL.
SLY FLOW AHEAD OF A LATE THURSDAY NIGHT COLD FRONT. SCA EXPANDED
THROUGH THURSDAY. EXPECT AN EXTENSION THURSDAY NIGHT FOR PREFRONTAL
SLY FLOW...THEN NWLY FLOW AROUND 25 KT FRIDAY THROUGH SATURDAY AS
HIGH PRESSURE BUILDS.
&&
.TIDES/COASTAL FLOODING...
A SOUTHERLY FLOW WILL CONTINUE OVER THE WATERS THROUGH THURSDAY
NIGHT...BUT THE FLOW MAY REMAIN JUST WEST OF SOUTH. TIDAL ANOMALIES
WILL LIKELY INCREASE A LITTLE...BUT WITH THE FLOW REMAINING WEST OF
SOUTH THE WATER LEVELS SHOULD REMAIN BELOW THRESHOLDS FOR MINOR
COASTAL FLOODING. THE CLOSEST WATER LEVELS WILL COME TO MINOR
FLOODING THRESHOLDS WILL BE DURING THE HIGH TIDE CYCLE LATE WEDNESDAY
NIGHT AND LATE THURSDAY NIGHT...THE HIGHER OF THE TWO HIGH TIDES.
TIDAL ANOMALIES WILL DECREASE FRIDAY BEHIND A COLD FRONT.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 9 PM THIS EVENING TO 6 PM EDT
THURSDAY FOR ANZ530-531-539.
SMALL CRAFT ADVISORY FROM 9 AM TO 6 PM EDT THURSDAY FOR ANZ535-
538.
SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 6 PM EDT
THURSDAY FOR ANZ532-536-540-542.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT THURSDAY FOR ANZ533-534-
537-541-543.
&&
$$
SYNOPSIS...BJL
NEAR TERM...HTS/BJL
SHORT TERM...BAJ
LONG TERM...BAJ
AVIATION...HTS/BJL/BAJ
MARINE...KLEIN/BJL/BAJ
TIDES/COASTAL FLOODING...BJL
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1026 PM EDT THU MAY 23 2013
.SYNOPSIS...
ISSUED AT 357 PM EDT THU MAY 23 2013
HIGH PRESSURE IS BUILDING INTO NORTHERN MICHIGAN TONIGHT...TO PUT
THE KIBOSH ON THE SOGGY CONDITIONS AND USHER IN A BEAUTIFUL HOLIDAY
WEEKEND. THAT HIGH PRESSURE SYSTEM WILL STICK AROUND THROUGH AT
LEAST MONDAY...PROVIDING PLENTY OF SUNNY BUT SEASONABLY COOL DAYS
AND CHILLY NIGHTS. SO CHILLY IN FACT...THAT FROST WILL BE POSSIBLE
OVER THE NEXT COUPLE NIGHTS.
&&
.UPDATE...
ISSUED AT 1026 PM EDT THU MAY 23 2013
SKIES HAVE CLEARED ACROSS MOST OF OUR CWA...WITH ONLY SOME
LINGERING SC ACROSS PORTIONS OF NE LWR MICHIGAN ATTM. ONLY FLY IN
THE CLEAR SKY OINTMENT FOR THE OVERNIGHT HOURS MAY BE A BANK OF
LOW CLOUDS DROPPING SOUTH THRU ERN ONTARIO. NAM AND GFS ARE NOT
HANDLING THIS AREA OF LOW CLOUDS WELL...THE RUC DOES ELUDE TO SOME
LOW LEVEL MOISTURE DROPPING SOUTH ALONG THE ERN EDGE OF THE
SURFACE RIDGE...BUT ACTUALLY KEEPS THIS MOISTURE EAST OF OUR CWA.
WILL CERTAINLY NEED TO KEEP AN EYE ON THIS AREA OF LOW CLOUDS TO
SEE IF IT GRAZES OUR ERN CWA. THIS WILL CERTAINLY HAVE AN IMPACT
ON LOW TEMPS AND FROST POTENTIAL OVERNIGHT. FOR NOW...WILL MAKE
SOME UPWARD ADJUSTMENTS TO CLOUD COVER FOR OUR ERN COUNTIES...BUT
WILL FALL SHORT OF A MOSTLY CLOUDY FORECAST. WILL KEEP THE FROST
ADVISORY IN TACT FOR ALL AREAS FOR NOW...BUT AGAIN WILL NEED TO
KEEP AN EYE ON THIS CLOUD COVER AND ITS POTENTIAL IMPACT ON
OVERNIGHT LOWS AND FROST DEVELOPMENT.
UPDATE ISSUED AT 718 PM EDT THU MAY 23 2013
SKIES CONTINUE TO CLEAR FROM NW TO SE ACROSS OUR CWA THIS EVENING
AS STRONG CANADIAN HIGH PRESSURE AND DRY AIR THRU THE COLUMN BUILD
INTO THE WRN GREAT LAKES REGION. AS SKIES CLEAR AND WINDS DIMINISH
WITH SUNSET...TEMPS WILL QUICKLY FALL THRU THE 40S AND INTO THE
30S OVERNIGHT. FROST DEVELOPMENT IS STILL A GOOD BET GIVEN CURRENT
DWPTS IN THE LOW 30S.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 357 PM EDT THU MAY 23 2013
ON THE LATEST SURFACE WEATHER MAP...1033 MB HIGH PRESSURE WAS OVER
NORTHERN MANITOBA CANADA WITH 1004 MB LOW PRESSURE OVER NORTHEAST NEW
YORK STATE. APX AND SURROUNDING RADARS SHOW THE BACK EDGE OF
DEPARTING RAINFALL EXITING INTO LAKE HURON. SATELLITE IMAGERY AND
SURFACE OBSERVATIONS SHOWS MARKED CLEARING ADVECTING IN FROM THE
NORTH AND WEST. THE MAIN SHORT TERM FORECAST CONCERN REVOLVES AROUND
LOW TEMPERATURES AND ASSOCIATED FROST/FREEZE HEADLINES TONIGHT.
TONIGHT...UNSEASONABLY COLD AIR ASSOCIATED WITH ARCTIC TYPE HIGH
PRESSURE CONTINUES TO BUILD IN FROM THE NORTHWEST. THIS WILL RESULT
IN SLOWLY DIMINISHING WINDS AND MAINLY CLEAR SKIES. THERE ARE A
COUPLE OF COMPETING FACTORS TO CONTEND WITH AS FAR AS LOW
TEMPERATURES GO. BOUNDARY LAYER WINDS DO NOT LOOK LIKE THEY FULLY
DECOUPLE WITH 950 MB WINDS REMAINING IN THE 15 TO 20 KNOT RANGE
THROUGH 12Z FRIDAY. HOWEVER...FROM A PURE COLD ADVECTION STANDPOINT
WITH 850 MB TEMPERATURES BOTTOMING OUT BETWEEN -2 AND -3
C...TEMPERATURES SHOULD NOT HAVE MUCH OF A PROBLEM FALLING THROUGH
THE 30S. COULD EVEN SEE SOME SHELTERED SPOTS HIT THE UPPER (OR EVEN
MIDDLE 20S). SO AT A MINIMUM...TEMPERATURES EXPECTED TO BE COLD
ENOUGH TO SUPPORT FROST (THOUGH THE EXTREMELY DRY AIR MASS VOID OF
MUCH MOISTURE IN ITSELF MAY NOT PRODUCE MUCH ACTUAL FROST) IN
ADDITION...TEMPERATURES IN A FEW SHELTERED SPOTS COULD SUPPORT A
FREEZE (BUT THIS IS NOT EXPECTED TO BE WIDESPREAD). SO WITH ALL THIS
IN MIND...WILL CONTINUE WITH THE ONGOING FROST ADVISORY...AS WELL AS
AN EXPANSION EASTWARD INTO THE REMAINING COUNTIES BORDERING LAKE
HURON.
FRIDAY...HIGH PRESSURE CONTINUES TO BUILD IN FROM THE NORTHWEST WITH
A VERY SLOW MODIFICATION IN TEMPERATURES. MODEL SOUNDING/CROSS
SECTIONS ARE VERY DRY...SUPPORTING LITTLE TO NO CLOUD COVER...SO
MOSTLY SUNNY CONDITIONS ARE EXPECTED. TEMPERATURES ARE STILL EXPECTED
TO BE A GOOD 10 TO 15 DEGREES BELOW AVERAGE FOR LATE MAY WITH HIGHS
ONLY IN THE MIDDLE 50S TO AROUND 60.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 357 PM EDT THU MAY 23 2013
RECENT TRENDS: TEMPERATURES...WARMING TREND LAST SEVEN DAYS ACROSS
NORTHERN MICHIGAN (ABOUT 2-4C ABOVE AVERAGE) THOUGH NOT A GREAT
START OUT THERE TODAY. 1-3C ABOVE NORMAL FOR THE MONTH OF MAY THUS
FAR. PRECIPITATION/HYDROLOGY: SIGNIFICANT RAINFALL LAST COUPLE OF
DAYS...SOME LOCALES PICKING UP 2-3+ INCHES OF PRECIP. OVERALL SOIL
MOISTURE (TOP 1M) STILL ABOVE NORMAL...TOP 25CM MOSTLY BELOW 50
PERCENT CAPACITY. AREA RIVERS ON THE RISE AFTER RAINFALL...RIFLE
RIVER NEAR STERLING ALREADY IN FLOOD WITH A FORECAST RISE OF ANOTHER
1.5 FEET OR SO. GREAT LAKES: WATER TEMPERATURES AVERAGING 4-5C
NORTHERN LAKES MICHIGAN/HURON...AROUND 6-7C FROM BEAVER ISLAND NORTH
AND EAST TO THE STRAITS. LAKE SUPERIOR/WHITEFISH BAY AROUND 3C.
LARGE SCALE PATTERN/FORECAST: SMALL-SCALE OMEGA BLOCKING PATTERN
ACROSS NORTH AMERICA WITH TROUGHS EAST AND WEST AND A NARROW RIDGE
IN BETWEEN. OVERALL RECENT PATTERN HAS BEEN PRETTY PROGRESSIVE (45
DAY HOVMOLLER ANALYSIS REFLECTS THIS RATHER NICELY)...THOUGH THE
CURRENT BLOCKING WILL KEEP THINGS HEMMED IN A BIT WITH EAST COAST
CYCLOGENESIS THIS WEEKEND HELPING BOG THINGS DOWN. BUT THE OVERALL
TREND INTO NEXT WEEK SHOULD BE RISING HEIGHTS ACROSS THE EAST WITH
MORE PERSISTENT TROUGHING OUT WEST (AND THUS AN OVERALL WARMING
TREND).
HIGH PRESSURE BUILDS INTO THE GREAT LAKES THIS WEEKEND AND GETS
STUCK BETWEEN AFOREMENTIONED EAST COAST CYCLONE AND LEE CYCLOGENESIS
ACROSS THE CENTRAL HIGH PLAINS. WATER VAPOR IMAGERY SHOWS A COMPACT
VORTICITY CENTER CROSSING 60N INTO NORTHERN MANITOBA THIS AFTERNOON
THAT IS FORECAST TO FLY BY EAST OF MICHIGAN EARLY SATURDAY...BUT
OTHERWISE NOT MUCH EXPECTED SYNOPTICALLY THROUGH SUNDAY. MAIN
FORECAST CONCERNS LOOK TO REVOLVE AROUND TEMPERATURES AND FROST
POTENTIAL THIS WEEKEND.
FRIDAY NIGHT THROUGH SUNDAY: SHORT WAVE TROUGH/JET STREAK WILL DROP
ACROSS LAKE HURON FROM THE NORTHWEST FRIDAY NIGHT...DISTURBANCE DOES
HAVE AN AREA OF CIRRUS WITH IT THAT WILL FLOAT ACROSS FOR A TIME.
WILL PROBABLY HAVE SOME IMPACT ON LOW TEMPERATURES BUT STILL EXPECT
A CHILLY NIGHT WITH LOWS DROPPING INTO THE 30S WITH SOME THREAT FOR
FROST ACROSS THE INTERIOR. PARTLY TO MOSTLY SUNNY SATURDAY...DEEP
MIXING WILL ALLOW TEMPERATURES TO WARM INTO THE 60S THOUGH MAY STILL
FALL A BIT SHORT OF AVERAGE FOR THE DAY.
SIMILAR STORY ON TAP FOR SATURDAY NIGHT...CLEAR/CLEARING SKIES AND
LIGHT/CALM WINDS WITH SURFACE RIDGE STUCK IN PLACE. PLAN TO MENTION
FROST POTENTIAL SUNDAY MORNING WITH LOWS ACROSS THE INTERIOR IN THE
LOWER-MID 30S. PLENTY OF SUN EXPECTED SUNDAY AFTERNOON ALONG WITH
SEASONABLE TEMPERATURES.
EXTENDED FORECAST (MONDAY THROUGH THURSDAY): HIGH PRESSURE EXPECTED
TO HOLD ON INTO THE MEMORIAL DAY HOLIDAY AND LIKELY INTO TUESDAY AS
WELL. THERE WILL BE A WARM FRONT ACROSS THE CENTRAL PLAINS AND INTO
THE MIDDLE MISSISSIPPI VALLEY THAT WILL BE THE MAIN FOCUS FOR
PRECIPITATION INTO NEXT WEEK...HOW QUICKLY THIS FEATURE LIFTS NORTH
TOWARD THE GREAT LAKES WILL BE THE ISSUE FOR THE LATTER HALF OF THE
EXTENDED PERIODS. TEMPERATURES WILL MODERATE MONDAY/TUESDAY...BUT
WILL START GETTING INTO BETTER WARM ADVECTION BY MIDWEEK. MAY ALSO
START TO GET NOTICEABLY MORE HUMID...AND BY WEDNESDAY MAY BE ENOUGH
INSTABILITY IN PLACE FOR SOME SHOWER/THUNDERSTORM DEVELOPMENT.
BETTER CHANCES FOR PRECIPITATION MAY BE IN THE OFFING FOR THURSDAY
AS WARM FRONT NUDGES CLOSER. HIGHS MEMORIAL DAY SHOULD BE WELL INTO
THE 60S/LOWER 70S...WITH MORE 70S DURING THE MIDWEEK PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 718 PM EDT THU MAY 23 2013
MAINLY SKC IS EXPECTED AT ALL TAF SITES THRU FRIDAY EVENING AS
STRONG CANADIAN HIGH PRESSURE AND DRY AIR THRU THE COLUMN BUILD
SOUTH INTO MICHIGAN. GUSTY NORTH WINDS WILL DIMINISH WITH SUNSET
THIS EVENING...AND THEN BECOME GUSTY AGAIN ON FRIDAY.
&&
.MARINE...
ISSUED AT 357 PM EDT THU MAY 23 2013
GUSTY NORTH WINDS THROUGH THIS EVENING DUE TO A TIGHT SURFACE
PRESSURE GRADIENT AND STRONG WINDS ALOFT. WINDS ARE THEN EXPECTED TO
SLOWLY DIMINISH OVERNIGHT AS HIGH PRESSURE BEGINS TO BUILD INTO THE
NEARSHORE WATERS. THEREFORE...HAVE EXTENDED THE SMALL CRAFT
ADVISORIES THROUGH LATE EVENING. HIGH PRESSURE IS THEN EXPECTED TO
GAIN FULL CONTROL FRIDAY INTO THE HOLIDAY WEEKEND LEADING TO
HEADLINE FREE CONDITIONS.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...FROST ADVISORY FROM 2 AM TO 8 AM EDT FRIDAY FOR MIZ016>036-041-
042.
LH...SMALL CRAFT ADVISORY UNTIL 2 AM EDT FRIDAY FOR LHZ345>349.
LM...SMALL CRAFT ADVISORY UNTIL 2 AM EDT FRIDAY FOR LMZ323-341-342-
344>346.
LS...SMALL CRAFT ADVISORY UNTIL 2 AM EDT FRIDAY FOR LSZ321-322.
&&
$$
UPDATE...MR
SYNOPSIS...KAB
SHORT TERM...AJS
LONG TERM...JPB
AVIATION...MR
MARINE...AJS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
402 PM EDT WED MAY 22 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 353 PM EDT WED MAY 22 2013
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW SLUGGISH UPR LO
OVER THE UPR MS RIVER VALLEY BTWN RDG OFF THE SE CONUS AND ANOTHER
RDG AXIS OVER THE ROCKIES. BAND OF -SHRA STRETCHING FM NE MN INTO
THE WRN CWA UNDER BAND OF H85-7 FGEN TO THE NE OF THE CLOSED LO IS
HOLDING FIRM EVEN THOUGH LLVL DRY AIR IS SURGING INTO NE MN/WRN LK
SUP IN STEADY NE FLOW BTWN HI PRES OVER NRN MANITOBA AND SFC LO PRES
IN THE LOWER LKS. ANOTHER LARGER AREA OF SHRA/ISOLD TS OVER THE SE
HALF OF WI/S HALF OF LK MI IS EXPANDING TO THE N AS SHRTWV OVER
IL/LEFT EXIT REGION OF SUPPORTING H3 JET MAX IS MOVING N OF THE
CLOSED LO. OTRW...LO CLDS HAVE BEEN QUITE PERSISTENT OVER UPR MI
WITH CHILLY NE WIND OFF LK SUP. SOME FOG HAS PERSISTED AS WELL NEAR
LK SUP E OF THE KEWEENAW...WHERE THE LLVL DRY AIR HAS NOT YET
ARRIVED.
MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE HOW DRIER AIR ARRIVING
FM THE N WL IMPACT POPS ASSOCIATED WITH BAND OF FGEN OVER THE WRN
ZNS AND AREA OF SHRA MOVING N TOWARD THE SE COUNTIES.
TNGT...UPR LO NOW OVER SE MN IS PROGGED TO DRIFT ESE...AND NAM SHOWS
BAND OF H85-7 FGEN/H85-5 QVECTOR CNVGC FOLLOWING THIS FEATURE SEWD
ACRS MAINLY THE W HALF OF THE CWA. AT THE SAME TIME...H7-3 QVECTOR
CNVGC/UPR DVGC IN LEFT EXIT AHEAD OF SHRTWV/SUPPORTING UPR JET
LIFTING NNEWD WL IMPACT MAINLY THE SE COUNTIES. LOOKS LIKE THESE
DYNAMICS MAY INTERACT FOR A TIME LATE THIS AFTN/EARLY EVNG OVER THE
SE ZNS. SO HIER POPS IN THIS AREA AT THAT TIME SEEM APPROPRIATE. AT
THE SAME TIME...DRIER AIR SURGING INTO THE NW CWA UNDER STRONGER NNE
FLOW WL END ANY LINGERING PCPN AS FGEN AXIS SHIFTS TO THE SE. THE
PCPN WL END EVEN OVER THE SE ZNS AFT 06Z FOLLOWING DEPARTURE OF
SHRTWV/ACCOMPANYING DYNAMICS AND ARRIVAL OF DRIER LLVL AIR. THE
ARRIVAL OF THE DRIER LLVL AIR AND EXIT OF THE DYNAMICS WL ALLOW FOR
SOME CLRG...BUT THE UPSLOPE NNE FLOW MAY SLOW THE PROCESS OVER THE
HIER TERRAIN NEAR LK SUP.
THU...HI PRES IS FCST TO BLD INTO THE UPR LKS...RESULTING IN DRY WX.
ALTHOUGH LINGERING H85 THERMAL TROF WITH TEMPS ARND 0C THRU 00Z
WOULD INDICATE QUITE A BIT OF DIURNAL CU/SC AT THIS TIME OF YEAR
OVER LAND...DRYNESS OF INCOMING AIRMASS AS WELL AS LLVL ACYC/
DIFFLUENT FLOW WL RESULT IN MOCLR SKIES. IF THERE IS ANY UPSLOPE SC
OVER THE HIER TERRAIN NEAR LK SUP...THIS CLD WL MIX OUT EARLY. THE
FCST H85 TEMPS AND MIXING TO H8-85 ON NAM FCST SDNGS YIELDS HI TEMPS
TOPPING OUT IN THE 50S OVER THE INTERIOR. BUT STIFF NNE WIND OFF LK
SUP WL CAUSE TEMPS TO HOLD IN THE 40S NEAR THE BIG LAKE. THESE
STRONGER NE WINDS WL DIMINISH OVER THE W IN THE AFTN WITH THE APRCH
OF THE HI CENTER/WEAKENING PRES GRADIENT.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 353 PM EDT WED MAY 22 2013
SLOW MOVING AND RATHER STABLE UPPER AIR PATTERN EXPECTED THROUGH THE
ENTIRE LENGTH OF THE LONG TERM. INITIALLY LATE THIS WEEK...THERE IS
A TROUGH OVER PACIFIC NORTHWEST WITH RIDGING OVER CENTRAL CONUS...
AND TROUGHING OVER MUCH OF EASTERN CANADA ACROSS THE GREAT LAKES.
EXPECT BELOW NORMAL TEMPERATURES TO PREVAIL THROUGH THE HOLIDAY
WEEKEND AS THE TROUGH ONLY SLOWLY MOVES TO THE EAST. EVENTUALLY...
WARMER TEMPERATURES ARE EXPECTED BY MIDDLE OF NEXT WEEK WHEN RIDGING
EXPANDS FROM PLAINS ACROSS THE GREAT LAKES. AFTER AN UNSETTLED AND
WET WEEK THAT HAS OCCURRED OVER THE UPPER GREAT LAKES...HUDSON BAY
HIGH PRESSURE RIDGING ACROSS THE GREAT LAKES SHOULD BRING A
PROLONGED PERIOD OF DRY WEATHER INTO NEXT WEEK. CERTAINLY POSSIBLE
THIS DRY WEATHER STRETCH MAY EVEN PERSIST INTO THE MIDDLE OF NEXT
WEEK. WARM FRONT FORMING TO THE SOUTH AND WEST OF UPPER MICHIGAN
WILL RESULT IN SOME SMALLER CHANCES OF PRECIP BY NEXT WEDNESDAY...
BUT GIVEN THE VERY DRY AIRMASS IN PLACE...GREATEST CHANCE OF SHOWERS
AND STORMS WILL LIKELY STAY TO WEST OF UPPER LAKES CLOSER TO AXIS OF
HIGHER H85-H7 MOISTURE AND INSTABILITY.
GUSTY WINDS AROUND ON THURSDAY DIMINISH BY THE WEEKEND AS HIGH
PRESSURE BUILDING SOUTH OUT OF NORTHERN ONTARIO BECOMES MORE
ESTABLISHED. LIGHTER WINDS ON THURSDAY NIGHT AND VERY DRY AIRMASS
OVERHEAD DUE TO STRONG MIXING EARLIER IN THE DAY WILL SUPPORT MIN
TEMPS DROPPING TO AROUND 20 DEGREES INTERIOR WEST AND IN THE 20S TO
LOWER 30S ELSEWHERE. EXPECT WIDESPREAD FROST FOR MANY AREAS ON
THURSDAY NIGHT. WE DO NOT OFFICIALLY BEGIN THE FROST AND FREEZE
HEADLINES UNTIL MEMORIAL DAY BUT WILL CONTINUE TO INCLUDE MENTION IN
THE GRIDS. WITH STRONG HIGH PRESSURE OVER THE AREA...NEAR 1030MB...
LAKE BREEZES MAY GET GUSTY AT TIMES THIS WEEKEND. AFTER A COOLER DAY
ALL AREAS ON FRIDAY...COOLING WILL BECOME MORE OF A LAKESIDE FEATURE
THROUGH THE WEEKEND AS INLAND AREAS RISE INTO THE 60S.
SEEMS THERE IS A SLIM CHANCE OF LGT RAIN/SPRINKLES OVER FAR WEST
CWA LATE FRIDAY NIGHT INTO SATURDAY MORNING. 12Z NAM SOUNDINGS SHOW
MOISTURE IN MID LEVELS ENHANCED BY RIGHT ENTRANCE REGION OF
DEPARTING JET STREAK OVER ONTARIO BUILDING DOWN ENOUGH ALONG WITH
SUFFICIENT UVM TO RESULT IN BAND OF LGT SHRA MAKING IT INTO IWD
06Z-12Z ON SATURDAY. ECMWF/GFS SHOW SOME MID LEVEL MOISTURE BUT HAVE
QPF STAYING OUT OF CWA. 12Z ECMWF DOES SHOW A BIT NOW THOUGH. NAM
SEEMS TOO AGGRESSIVE WITH EASTWARD PUSH OF LGT PRECIP SO WILL NOT
PUT A MENTION IN YET. INCREASE IN CLOUDS OVERNIGHT WILL IMPACT MIN
TEMPS AND MAY RESTRICT POTENTIAL FOR FROST...AT LEAST IN THE
INTERIOR WEST CWA. ELSEWHERE...TEMPS DROPPING INTO THE UPPER 20S OR
NEAR 30 DEGREES WILL SUPPORT MORE FROST...ESPECIALLY INLAND FROM THE
LAKES. IF THERE ARE BKN CLOUDS WEST...THEY SHOULD DISSIPATE BY
SATURDAY EVENING RESULTING IN ANOTHER COOL NIGHT WITH SOME FROST
INLAND FROM THE GREAT LAKES SHORES.
DUE TO COOL AND DAMP WEATHER AND MODERATE RAIN AMOUNTS IN SOME AREAS
/HAD REPORT TODAY OF OVER 4 INCHES TO WEST OF ONTONAGON/...FIRE
WEATHER ISSUES ARE TAKING A BRIEF HIATUS. EVENTUALLY DUE TO ALMOST A
WEEK OF DRYING...INCREASING SOUTH/SOUTHWEST WINDS...AND WARMER
TEMPERATURES INTO THE 70S EARLY-MID NEXT WEEK MAY SEE INCREASING
FIRE WEATHER CONCERNS FOR AREAS THAT HAVE NOT EXPERIENCED A FULL
GREEN UP AND/OR SEEN A LOT OF RAIN OVER THE LAST FEW DAYS. &&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 123 PM EDT WED MAY 22 2013
AS A STEADY NNE WIND BTWN HI PRES IN SCENTRAL CANADA AND LO PRES
OVER THE LWR GRT LKS ADVECTS MUCH DRIER LLVL AIR OVER UPR MI...
EXPECT IMPROVING CONDITIONS TO VFR THIS EVNG. CMX WL BE CLOSER TO
THE INCOMING DRIER AIR AND SEE A QUICKER IMPROVEMENT THAN AT IWD/
SAW...WHERE A MORE SGNFT UPSLOPE WIND COMPONENT WL ALSO SLOW THE
TREND TOWARD VFR. UNDER A TIGHTENING PRES GRADIENT...EXPECT GUSTY
NNE WINDS AT ALL 3 SITES TNGT/THU MRNG.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 353 PM EDT WED MAY 22 2013
EXPECT INCREASING NE WINDS UP TO 25-30 KTS UNDER SHARPENING PRES
GRADIENT IN ADVANCE OF HI PRES BUILDING TOWARD LAKE SUP THRU
TONIGHT. THIS STRENGTHENING FLOW WILL ADVECT DRIER AIR OVER THE
LAKE...SO LINGERING FOG SHOULD DISSIPATE THIS EVENING. BASED ON
CURRENT VISIBILITY REPORTS/WEBCAM IMAGERY NEAR THE LAKE...OPTED TO
CANX GOING DENSE FOG ADVISORIES THAT WERE SET TO EXPIRE AT 21Z.
CLOSER APPROACH OF HI PRES/WEAKER PRES GRADIENT WILL RESULT IN
SLOWLY DIMINISHING WINDS W TO E ON THU. AS HIGH PRESSURE CONTINUES TO
SPREAD ACROSS THE UPPER GREAT LAKES THROUGH THE WEEKEND...EXPECT
WINDS LESS THAN 20 KTS ON LAKE SUPERIOR. LIGHTER WINDS WILL CONTINUE
INTO EARLY NEXT WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
DENSE FOG ADVISORY UNTIL 6 PM EDT THIS EVENING FOR LMZ221-248-
250.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...KC
MARINE...KC/JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
407 AM EDT WED MAY 22 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 357 PM EDT TUE MAY 21 2013
12Z ROABS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW SLOW MOVING UPR LO
OVER ERN SDAKOTA BTWN UPR RDG OVER SCENTRAL CANADA AND A RIDGE OFF
THE SE CONUS. BAND OF SHRA/SCT TS THAT IMPACTED THE CWA EARLIER HAS
LIFTED TO THE N ALONG WITH RESPONSIBLE SHRTWV...ALLOWING FOR MAINLY
DRY WX OVER UPR MI EARLY THIS AFTN. BUT SINCE THE CWA IS N OF SFC
WARM FNT IN WI...PLENTY OF LO CLDS LINGER. THERE IS ALSO SOME FOG...
MAINLY NEAR THE COOLER GREAT LKS. ANOTHER DISTURBANCE IS ROTATING N
THRU IOWA ARND THE CLOSED LO. THE APRCH OF THIS DISTURBANCE HAS
RESULTED IN SOME SHRA OVER CENTRAL WI WHERE BREAKS IN THE LO CLDS
ALONG AND S OF WARM FNT HAVE LIFTED SB CAPE 500-1000 J/KG PER SPC
MESOANALYSIS.
MAIN FCST CONCERNS IN THE SHORT TERM ARE SHRA/TS TRENDS ASSOCIATED
WITH SHRTWV IN IOWA AND THEN APRCH OF MAIN UPR LO.
LATE THIS AFTN/TNGT...SHORT RANGE MODELS ARE IN FAIRLY GOOD
AGREEMENT SHOWING SHRA NOW OVER CENTRAL WI DRIFTING ACRS THE WI
BORDER BY 21Z AND THEN CONTINUING TO THE NE. RUC FCST SDNGS MODIFIED
FOR TEMP/DEWPT OF 68/58 YIELDS SBCAPE UP TO 750 J/KG...SO ADDED
MENTION OF TS. RELATIVELY WEAK WINDS SFC-H5 AS WELL AS DEEP
MSTR/SKINNY CAPE WITH PERSISTENT LO CLDS LIMITING DIURNAL HEATING
INDICATE A LO RISK FOR ANY SVR TS...BUT ANY SHRA COULD RESULT IN
SOME HEAVY RA WITH FCST KINX AS HI AS THE UPR 30S. ONCE THE SHRA
MOVE FARTHER TO THE NE AND AWAY FM THE SFC HEATING AREA...ONE MIGHT
EXPECT THESE SHRA TO DIMINISH THRU THE NGT. BUT FCST AREA OF H85-7
FGEN N OF WARM FNT MIGHT ACT TO SUSTAIN THESE SHRA. WL GO WITH HI
CHC-LIKELY POPS THIS EVNG NEAR THE WI BORDER DIMINISHING TO CHCY
POPS TO THE NE. SINCE THE LLVL FLOW IS FCST TO BACK MORE TO THE NE
FOLLOWING THE PASSAGE OF THIS SHRA AREA...EXPECT COOLER LAKE
AIR/SOME FOG TO MOVE BACK INTO THE AREA OVERNGT.
WED...AS CLOSED LO TO THE W BEGINS TO SHIFT FASTER TO THE ESE TO SW
WI BY 00Z THU...AREA OF LARGER SCALE QVECTOR CNVGC WL IMPACT MAINLY
THE AREA NEAR THE WI BORDER BUT WEAKEN WITH TIME AS THE UPR CLO
BEGINS TO OPEN. BAND OF RA ACCOMPANYING AXIS OF SHARPER FGEN OVER
WRN LK SUP/THE WRN ZNS SHOULD THUS SHIFT SLOWLY TO THE SE THRU THE
DAY. ARRIVAL OF DRIER AIR FM THE NW TO THE SE OF EXPANDING HI PRES
OVER SCENTRAL CANADA MIGHT START TO DIMINISH THE PCPN OVER THE FAR W
LATER IN THE DAY. OTRW...LOWERED FCST HI TEMPS TO ACCOUNT FOR STEADY
NE WIND OFF LK SUP AND EXPECTED CLD COVER.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 407 AM EDT WED MAY 22 2013
A CLOSED 500 MB LOW WILL BE IN THE PACIFIC NW WITH A TROUGH OVER THE
GREAT LAKES REGION AND A RIDGE ACROSS THE PLAINS 12Z THU. PATTERN
CHANGES LITTLE THIS FORECAST PERIOD WITH THE TROUGH OVER THE GREAT
LAKES MOVING TO THE EASTERN U.S. 12Z SAT AND THE RIDGE STAYING PUT
IN THE PLAINS. LOOKS DRY FOR THIS FORECAST PERIOD WITH COLD
TEMPERATURES. THERE WILL BE SOME FROST FOR THU NIGHT AND FRI NIGHT
AND PUT IT IN THE WEATHER GRIDS TO HELP WITH THE FIRE WEATHER
FORECAST. THE FROST/FREEZE SEASON STARTS AFTER MEMORIAL DAY...BUT
WILL MENTION THIS IN THE HWO PRODUCT. WITH THE RIDGE NEARBY AND VERY
DRY AND COLD AIR...GOOD RADIATIONAL COOLING CONDITIONS WILL SET UP
AND WENT WITH THE COLDEST GUIDANCE I COULD FIND FOR LOW TEMPERATURES
WHICH WAS THE ADJMET AND MADE A FEW ADJUSTMENTS FOR COLDER SPOTS.
HIGHS ON THU WILL STRUGGLE TO GET TO THE MID 50S. FOR FRI...WENT
COLDER FOR HIGHS AS WELL WITH A COLDER START IN THE MORNING AND 850
MB TEMPERATURES WARMING ONLY TO 4C. MIXING THIS DOWN TO THE SFC
WOULD GIVE ME HIGHS AROUND 60 AT BEST. THE TEMPERATURES WERE THE
MAIN THING THAT I ADJUSTED FOR THIS FORECAST WITH A SLIGHTLY COLDER
FORECAST.
IN THE EXTENDED...ECMWF AND GFS SHOW A 500 MB RIDGE ACROSS THE
PLAINS WITH TROUGHING IN THE PACIFIC NW AND IN NEW ENGLAND 12Z SAT.
PATTERN CHANGES VERY LITTLE 12Z SUN THROUGH 12Z TUE. WILL BE FAIRLY
DRY THIS FORECAST PERIOD AND QUIET WITH COLDER THAN NORMAL
TEMPERATURES WITH A SLOW WARMING TREND THROUGH THE PERIOD. THERE IS
A SLIGHT CHANCE FOR PCPN MONDAY NIGHT AND TUESDAY WITH A WARM FRONT
SETTING UP TO THE SOUTH...BUT NOT REAL IMPRESSED WITH SEEING MUCH
RAIN OUT OF THIS FOR NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1209 AM EDT WED MAY 22 2013
COOL/MOIST AIR UPSLOPING OFF LAKE SUPERIOR WILL LIKELY RESULT IN
LIFR CONDITIONS AT KIWD/KCMX/KSAW THRU THE NIGHT. CONDITIONS MAY END
UP VLIFR FOR MUCH OF THE NIGHT AT KSAW UNDER A MORE DIRECT LIGHT
UPSLOPE FLOW. EXPECT -SHRA/-DZ AT TIMES...ESPECIALLY AT KIWD/KCMX
DUE TO AN AREA OF MORE PERSISTENT SYNOPTIC FORCING. THESE MORE
PERSISTENT -SHRA SHOULD DRIFT SE AND AFFECT KSAW WED AFTN. THERE IS
LIGHT AT THE END OF THE TUNNEL AS LOW LOW PRES THAT HAS PLAGUED THE
AREA IN RECENT DAYS WILL CONTINUE TO WEAKEN AND WILL BE SHUNTED SE
BY HIGH PRES NOSING S TOWARD THE UPPER LAKES. DRIER AIR ASSOCIATED
WITH THE HIGH WILL LEAD TO STEADILY IMPROVING CONDITIONS FROM N TO S
WED AFTN/EVENING. KIWD/KCMX SHOULD BREAK OUT TO VFR IN THE
EVENING...PERHAPS SOONER...ESPECIALLY AT KCMX. IT MAY NOT BE UNTIL
NEAR THE END OF THIS FCST PERIOD THAT KSAW IMPROVES TO VFR.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 407 AM EDT WED MAY 22 2013
ARRIVAL OF DRIER AIR FROM THE NW TODAY WILL SLOWLY DIMINISH THE FOG
ON THE GREAT LAKES. GUSTY NORTHERLY WINDS ARE EXPECTED BEHIND THE
LOW PRESSURE SYSTEM TONIGHT INTO THURSDAY...BUT LINGERING WARM AIR
ALOFT SHOULD KEEP WINDS IN 20-25KT RANGE. THEN...A HIGH PRESSURE
RIDGE BUILDING SOUTHEAST OVER THE UPPER GREAT LAKES FOR THURSDAY
NIGHT THROUGH THE WEEKEND WILL BRING LIGHT WINDS TO LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LSZ249>251-
266-267.
DENSE FOG ADVISORY UNTIL 2 PM EDT /1 PM CDT/ THIS AFTERNOON FOR
LSZ162-240>242-245>248-263-265.
DENSE FOG ADVISORY UNTIL 8 AM EDT THIS MORNING FOR LSZ243-244-
264.
LAKE MICHIGAN...
DENSE FOG ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR LMZ221-248.
DENSE FOG ADVISORY UNTIL 6 PM EDT THIS EVENING FOR LMZ250.
&&
$$
SHORT TERM...KC
LONG TERM...07
AVIATION...ROLFSON
MARINE...07
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1210 AM EDT WED MAY 22 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 357 PM EDT TUE MAY 21 2013
12Z ROABS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW SLOW MOVING UPR LO
OVER ERN SDAKOTA BTWN UPR RDG OVER SCENTRAL CANADA AND A RIDGE OFF
THE SE CONUS. BAND OF SHRA/SCT TS THAT IMPACTED THE CWA EARLIER HAS
LIFTED TO THE N ALONG WITH RESPONSIBLE SHRTWV...ALLOWING FOR MAINLY
DRY WX OVER UPR MI EARLY THIS AFTN. BUT SINCE THE CWA IS N OF SFC
WARM FNT IN WI...PLENTY OF LO CLDS LINGER. THERE IS ALSO SOME FOG...
MAINLY NEAR THE COOLER GREAT LKS. ANOTHER DISTURBANCE IS ROTATING N
THRU IOWA ARND THE CLOSED LO. THE APRCH OF THIS DISTURBANCE HAS
RESULTED IN SOME SHRA OVER CENTRAL WI WHERE BREAKS IN THE LO CLDS
ALONG AND S OF WARM FNT HAVE LIFTED SB CAPE 500-1000 J/KG PER SPC
MESOANALYSIS.
MAIN FCST CONCERNS IN THE SHORT TERM ARE SHRA/TS TRENDS ASSOCIATED
WITH SHRTWV IN IOWA AND THEN APRCH OF MAIN UPR LO.
LATE THIS AFTN/TNGT...SHORT RANGE MODELS ARE IN FAIRLY GOOD
AGREEMENT SHOWING SHRA NOW OVER CENTRAL WI DRIFTING ACRS THE WI
BORDER BY 21Z AND THEN CONTINUING TO THE NE. RUC FCST SDNGS MODIFIED
FOR TEMP/DEWPT OF 68/58 YIELDS SBCAPE UP TO 750 J/KG...SO ADDED
MENTION OF TS. RELATIVELY WEAK WINDS SFC-H5 AS WELL AS DEEP
MSTR/SKINNY CAPE WITH PERSISTENT LO CLDS LIMITING DIURNAL HEATING
INDICATE A LO RISK FOR ANY SVR TS...BUT ANY SHRA COULD RESULT IN
SOME HEAVY RA WITH FCST KINX AS HI AS THE UPR 30S. ONCE THE SHRA
MOVE FARTHER TO THE NE AND AWAY FM THE SFC HEATING AREA...ONE MIGHT
EXPECT THESE SHRA TO DIMINISH THRU THE NGT. BUT FCST AREA OF H85-7
FGEN N OF WARM FNT MIGHT ACT TO SUSTAIN THESE SHRA. WL GO WITH HI
CHC-LIKELY POPS THIS EVNG NEAR THE WI BORDER DIMINISHING TO CHCY
POPS TO THE NE. SINCE THE LLVL FLOW IS FCST TO BACK MORE TO THE NE
FOLLOWING THE PASSAGE OF THIS SHRA AREA...EXPECT COOLER LAKE
AIR/SOME FOG TO MOVE BACK INTO THE AREA OVERNGT.
WED...AS CLOSED LO TO THE W BEGINS TO SHIFT FASTER TO THE ESE TO SW
WI BY 00Z THU...AREA OF LARGER SCALE QVECTOR CNVGC WL IMPACT MAINLY
THE AREA NEAR THE WI BORDER BUT WEAKEN WITH TIME AS THE UPR CLO
BEGINS TO OPEN. BAND OF RA ACCOMPANYING AXIS OF SHARPER FGEN OVER
WRN LK SUP/THE WRN ZNS SHOULD THUS SHIFT SLOWLY TO THE SE THRU THE
DAY. ARRIVAL OF DRIER AIR FM THE NW TO THE SE OF EXPANDING HI PRES
OVER SCENTRAL CANADA MIGHT START TO DIMINISH THE PCPN OVER THE FAR W
LATER IN THE DAY. OTRW...LOWERED FCST HI TEMPS TO ACCOUNT FOR STEADY
NE WIND OFF LK SUP AND EXPECTED CLD COVER.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 357 PM EDT TUE MAY 21 2013
AFTER A WET START TO THE WEEK...THE LONG TERM PERIOD LOOKS TO BE
FAIRLY DRY AS CANADIAN HIGH PRESSURE SLIDES THROUGH THE UPPER GREAT
LAKES REGION.
FIRST...THE UPPER TROUGH THAT HAS BEEN INFLUENCING THE WEATHER FOR
THE START OF THE WORK WEEK WILL BE SITUATED OVER WISCONSIN AND IOWA
AND SHIFTING EAST THROUGH THE GREAT LAKES REGION ON WEDNESDAY
NIGHT. MEANWHILE...THE SURFACE LOW WILL BE LOCATED OVER LOWER
MICHIGAN AT 00Z THURSDAY AND BEGIN TO MOVE UP THE ST LAWRENCE
SEAWAY WEDNESDAY NIGHT INTO THURSDAY AS A SHORTWAVE INTENSIFIES THE
LOW. AS THIS OCCURS...HIGH PRESSURE ORIGINATING FROM NORTH CENTRAL
CANADA WILL BE MOVING A RIDGE INTO THE UPPER MISSISSIPPI VALLEY ON
WEDNESDAY NIGHT AND THE UPPER GREAT LAKES ON THURSDAY. WITH THE
UPPER TROUGH AND CLOSE PROXIMITY OF THE LOW...THERE WILL STILL BE
DEEPER MOISTURE AND 850-700MB Q-VECTOR CONVERGENCE OVER THE
SOUTHEAST HALF OF THE CWA. IN ADDITION...WITH THE INCREASING
NORTHERLY 850-700MB FLOW OVER THE AREA MODELS ARE CONSISTENT ON AN
AREA OF FGEN SETUP FROM IRONWOOD THROUGH EASTERN LAKE SUPERIOR AT
00Z THURSDAY. THEN AS THE LOW SHIFTS EAST...THE FGEN WILL SLIDE
SOUTHEAST THROUGH THE NIGHT AND LIKELY EXIT THE MOST IF NOT ALL OF
THE CWA BY 12Z THURSDAY. AT THIS POINT...THINKING THAT THE MOVEMENT
OF THE PRECIPITATION SHOULD KEEP AMOUNTS UNDER A QUARTER OF AN
INCH.
CANADIAN HIGH PRESSURE THEN BECOMES THE DOMINATING FEATURE FOR THE
REST OF THE PERIOD...AS THE AREA IS UNDER NORTHWEST FLOW ALOFT.
THIS DRY CANADIAN AIR AND COOLER NORTHERLY LOW LEVEL WINDS WILL
LEAD TO NICE BUT SLIGHTLY COOLER THAN NORMAL START TO THE MEMORIAL
DAY WEEKEND. THE STRONGEST NORTHERLY FLOW OFF LAKE SUPERIOR WILL BE
ON THURSDAY WITH THE CLOSER PROXIMITY OF THE EXITING LOW. THIS WILL
KEEP TEMPERATURES COOLER THAN MOST OF THE DAYS...WITH HIGHS IN THE
UPPER 40S NEAR LAKE SUPERIOR AND IN THE 50S INLAND. FRIDAY-SUNDAY
WILL BE DOMINATED BY LAKE BREEZES EACH DAY...WITH THE WARMEST
TEMPERATURES OVER THE INTERIOR LOCATIONS /60S/. THERE ARE HINTS OF A
COUPLE WEAK SHORTWAVES MOVING THROUGH THE NORTHWEST FLOW ALOFT
FRI-SUN...BUT WILL THE DRY AIR IN PLACE...WOULDN/T EXPECT MUCH FOR
PRECIPITATION CHANCES. UNDER THE HIGH PRESSURE RIDGE ON THURSDAY
NIGHT...EXPECT TO SEE SOME SUB FREEZING LOWS OVER THE INTERIOR
PORTIONS OF UPPER MICHIGAN. PWAT VALUES AROUND 40 PERCENT OF NORMAL
AND LIGHT WINDS WOULD BE FAVORABLE WELL BELOW NORMAL LOWS. MAV/MET
GUIDANCE PICKING UP ON THIS IDEA WITH LOWS BETWEEN 25-30 OVER THE
WEST AND THAT SEEMS FAIRLY REASONABLE. HAVE TRENDED THAT DIRECTION
AND LOWERED TEMPS OVER THE WEST AROUND 5 DEGREES. FROST/FREEZE
HEADLINES DON/T START UNTIL MEMORIAL DAY...SO THERE WON/T BE ANY
HEADLINES...BUT ANYONE THAT HAS PLANTED EARLY WILL NEED TO PREPARE
FOR A POTENTIAL FROST/FREEZE.
UPPER RIDGING THAT WILL BE NEARLY STATIONARY JUST EAST OF THE
NORTHERN ROCKIES DURING THIS PERIOD WILL BEGIN TO SHIFT EAST ON
SUNDAY NIGHT AS THE UPPER TROUGH OVER THE NEW ENGLAND STATES SHIFTS
EAST INTO THE ATLANTIC. THIS WILL START A GRADUAL WARMING TREND
TOWARDS MEMORIAL DAY AND INTO THE FIRST PART OF NEXT WEEK. IN
ADDITION...IT WILL ALSO BRING BETTER OPPORTUNITIES FOR SHORTWAVES
TO RIDE OVER THE RIDGE AND INTO THE AREA LATER MONDAY AND MORE
LIKELY TOWARDS TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1209 AM EDT WED MAY 22 2013
COOL/MOIST AIR UPSLOPING OFF LAKE SUPERIOR WILL LIKELY RESULT IN
LIFR CONDITIONS AT KIWD/KCMX/KSAW THRU THE NIGHT. CONDITIONS MAY END
UP VLIFR FOR MUCH OF THE NIGHT AT KSAW UNDER A MORE DIRECT LIGHT
UPSLOPE FLOW. EXPECT -SHRA/-DZ AT TIMES...ESPECIALLY AT KIWD/KCMX
DUE TO AN AREA OF MORE PERSISTENT SYNOPTIC FORCING. THESE MORE
PERSISTENT -SHRA SHOULD DRIFT SE AND AFFECT KSAW WED AFTN. THERE IS
LIGHT AT THE END OF THE TUNNEL AS LOW LOW PRES THAT HAS PLAGUED THE
AREA IN RECENT DAYS WILL CONTINUE TO WEAKEN AND WILL BE SHUNTED SE
BY HIGH PRES NOSING S TOWARD THE UPPER LAKES. DRIER AIR ASSOCIATED
WITH THE HIGH WILL LEAD TO STEADILY IMPROVING CONDITIONS FROM N TO S
WED AFTN/EVENING. KIWD/KCMX SHOULD BREAK OUT TO VFR IN THE
EVENING...PERHAPS SOONER...ESPECIALLY AT KCMX. IT MAY NOT BE UNTIL
NEAR THE END OF THIS FCST PERIOD THAT KSAW IMPROVES TO VFR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 357 PM EDT TUE MAY 21 2013
GIVEN WIDESPREAD AREA OF RA THAT IMPACTED MUCH OF LAKE SUP INTO THIS
MORNING...SOME RECENT SHIP OBS THAT INDICATED LO VISIBILITY...AND
SHALLOW COOL AIRMASS OVER THE LAKE...OPTED TO EXTENDED DENSE FOG
ADVY THRU TONIGHT. ARRIVAL OF DRIER AIR FROM THE NW ON WED WILL
SLOWLY DIMINISH THE FOG. OTHERWISE...NE WINDS UP TO 25 TO 30 KTS...
WITH SOME GALE FORCE GUSTS AT THE HIER PLATFORMS...WILL CONTINUE
STRONGEST OVER WESTERN LAKE SUP WHERE TERRAIN FUNNELING WILL ENHANCE
THE WIND SPEEDS.
GUSTY NORTHERLY WINDS ARE EXPECTED BEHIND THE LOW PRESSURE SYSTEM
ON WEDNESDAY NIGHT INTO THURSDAY...BUT LINGERING WARM AIR ALOFT
SHOULD KEEP WINDS IN 20-25KT RANGE. THEN...A HIGH PRESSURE RIDGE
BUILDING SOUTHEAST OVER THE UPPER GREAT LAKES FOR THURSDAY NIGHT
THROUGH THE WEEKEND WILL BRING LIGHT WINDS TO LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 6 AM EDT /5 AM CDT/ EARLY THIS MORNING
FOR LSZ162-243>249-263>267.
LAKE MICHIGAN...
DENSE FOG ADVISORY UNTIL 8 AM EDT THIS MORNING FOR LMZ221-248-
250.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1248 PM CDT WED MAY 22 2013
.UPDATE...
ISSUED AT 625 AM CDT WED MAY 22 2013
AS DISCUSSED EARLIER...ENDED UP MAKING A FEW ADJUSTMENTS TO VERY
SHORT TERM GRIDS BASED ON LATEST RADAR TRENDS...AND WITH SUPPORT
FROM THE LATEST RAP13/HRRR QPF/REFLECTIVITY. ALTHOUGH CANNOT RULE
OUT A FEW SPOTS REPORTING LIGHT MEASURABLE RAIN WITH THIS
ACTIVITY...ESPECIALLY IN THE NANCE/POLK COUNTY AREA...THINK THAT
NON-MEASURABLE SPRINKLES WILL BE THE DOMINANT STORY FOR MOST OF
THE AFFECTED AREA...AND THUS LEFT OUT A MEASURABLE POP.
HOWEVER...BEEFED UP SPRINKLE WORDING TO WIDESPREAD IN SEVERAL FAR
NORTHEAST COUNTIES THROUGH NOON 17Z...AND EXPANDED AN ISOLATED
SPRINKLE MENTION AS FAR SOUTH AS A LOUP CITY-GENEVA LINE. IT MAY
TURN OUT THAT THIS LIGHT PRECIP MAY BE OUT OF THE PICTURE WELL
BEFORE NOON...BUT GIVEN THE VERY SLOW MOVING NATURE OF THE PARENT
MID LEVEL LOW TO THE EAST ANYTHING IS POSSIBLE. ALSO BEEFED UP SKY
COVER PERCENTAGES FROM MOSTLY CLOUDY TO OUTRIGHT CLOUDY ACROSS
ROUGHLY THE NORTHEAST 1/2 OF THE CWA THROUGH MID-DAY...WHILE
LEAVING A MORE OPTIMISTIC TREND IN PLACE FARTHER SOUTHWEST. THE
LATEST HRRR IS NOW SPORTING A ROUGHLY 20 DEGREE HIGH-TEMP GRADIENT
ACROSS THE CWA THIS AFTERNOON FROM ONLY LOW-MID 50S NORTHEAST TO
MID 70S SOUTHWEST. OTHER SHORT TERM MODELS SUCH AS THE RAP13 ARE
NOT AS COOL IN THE NORTHEAST AS THE HRRR...AND THUS WILL RESIST
THE URGE TO MODIFY AFTERNOON HIGHS AT THIS TIME...BUT FOR SURE ITS
POSSIBLE THAT SOME NORTHEAST AREAS COULD STRUGGLE TO REACH THE
MID-UPPER 50S AND NEXT SHIFT WILL HAVE MONITOR TRENDS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 509 AM CDT WED MAY 22 2013
WHILE THERE IS CERTAINLY NO HIGH-IMPACT WEATHER DURING THE NEXT
24 HOURS...THERE ARE AT LEAST A FEW TRICKY ELEMENTS AT
HAND...INCLUDING THE EXTENT OF LOW STRATUS AND ITS POSSIBLE
INFLUENCE ON A FAIRLY DECENT SOUTHWEST-NORTHEAST TEMP
GRADIENT...AND ALSO THE EXTENT OF SPRINKLES/LIGHT RAIN SHOWERS
MAINLY THIS MORNING IN THE NORTHEAST.
08Z OBJECTIVE SURFACE ANALYSIS REVEALS NO MAJOR FEATURES ACROSS
THE CENTRAL PLAINS...WITH THE CWA POSITIONED BETWEEN A MODEST 1004
MILLIBAR LOW OVER EASTERN IA...AND A 1014MB HIGH OVER THE NEB
PANHANDLE...A SOUTHWARD EXTENSION OF A STRONGER...BROADER HIGH
WELL TO THE NORTH IN CANADA. WITHIN THE MODEST PRESSURE GRADIENT
BETWEEN THESE FEATURES...A FAIRLY STEADY NORTH-NORTHWEST BREEZE OF
10-15 MPH HAS PREVAILED THROUGH THE NIGH IN MOST AREAS...WITH
OCCASIONAL GUSTS OVER 20 MPH. TEMPERATURES WILL START OUT THE
MORNING SEASONABLY COOL...WITH EVENTUAL LOWS AIMED INTO THE MID-
UPPER 40S ALL AREAS. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM
MODEL DATA FEATURES A CLOSED 500MB LOW DRIFTING SLOWLY
EAST...CENTERED NEAR THE IA/SD/NEB BORDER...AND A FAIRLY SHARP MID
LEVEL TROUGH AXIS THEN TRAILING SOUTH-SOUTHEAST INTO THE MID-SOUTH
STATES. OFF TO THE WEST OF THE LOCAL AREA...A LOW AMPLITUDE MID
LEVEL RIDGE IS ALIGNED NORTH-SOUTH THROUGH THE ROCKIES...WITH A
FAIRLY VIGOROUS...EXPANSIVE CLOSED LOW SPINNING OVER THE PACIFIC
NORTHWEST. WHILE IT HAS TAKEN ITS TIME FORMING...11-3.9 MICRON
SATELLITE IMAGERY AND AUTOMATED OBS HAVE FINALLY REVEALED THE
FORMATION OF FAIRLY WIDESPREAD LOW STRATUS MAINLY IN THE 1500-2500
FT RANGE OVER MUCH OF THE CWA...ALTHOUGH SOME BREAKS IN THE CLOUDS
DO STILL EXIST. ALSO JUST WITHIN THE PAST 90 MINUTES OR SO...AN
INCREASING FLARE-UP OF LIGHT RAIN/SPRINKLES HAS TAKEN PLACE MAINLY
OVER THE FAR NORTHERN/NORTHEAST CWA...WITH UPSTREAM OBS AT PLACES
SUCH AS ONEILL AND ALBION CONFIRMING AT LEAST TRACE AMOUNTS ARE
FALLING.
TODAY...THE MAIN STORY ALOFT INVOLVES THE CONTINUED SLOW DEPARTURE
OF THE CLOSED MID LEVEL LOW...WITH THE CENTER OF THIS FEATURE
PROGGED TO ONLY REACH NORTHEAST IA BY 00Z. AT THE SURFACE...A
MODEST PRESSURE GRADIENT WILL REMAIN IN PLACE AS HIGH PRESSURE TO
THE NORTH NOSES SOUTHWARD...AND THIS IN COMBINATION WITH MIXING TO
AT LEAST 850MB IN MOST AREAS WILL RESULT IN SOMEWHAT BREEZY
CONDITIONS ESPECIALLY WITHIN THE NORTHEAST 2/3 OF THE CWA...WITH
SUSTAINED NORTHWEST WINDS 15 TO POSSIBLY 20 MPH...AND SOME HIGHER
GUSTS. THE REAL CHALLENGE TODAY LIES INITIALLY WITH THE EXTENT AND
INTENSITY OF RAINFALL...AND ALSO JUST HOW STUBBORN THE LOW STRATUS
DECK WILL BE...AND WHETHER OR NOT IT RETREATS SLOW NORTHEAST
DURING THE AFTERNOON. STARTING OUT EARLY THIS MORNING THROUGH MID-
DAY...HAVE INTRODUCED A MENTION OF SPRINKLES TO A PREVIOUSLY
PRECIP-FREE FORECAST FOR FAR NORTHEAST AREAS MAINLY NORTH OF A
GREELEY-POLK LINE...AS DECENT LOW-MID LEVEL SATURATION UP TO
AROUND 600MB RESIDES MAINLY IN THIS ZONE AND POINTS
NORTHEAST...ASSOCIATED WITH A BATCH OF MID LEVEL MOISTURE FOCUSED
IN THE DEFORMATION ZONE ON THE BACK-SIDE OF THE DEPARTING LOW. THE
VERY SHORT TERM QUESTION THAT WILL NEED PONDERED OVER THE NEXT FEW
HOURS IS WHETHER TO EXPAND THIS SPRINKLE MENTION SOUTHWESTWARD
CLOSER TO I-80 PER SUGGESTION OF THE LATEST HRRR REFLECTIVITY
PROG...AND ALSO WHETHER TO UP THE ANTE TO A MEASURABLE POP. WILL
GIVE IT SOME TIME TO SEE IF AREA OBSERVATIONS SUPPORT A FEW
HUNDREDTHS OF ACCUMULATIONS BEFORE POSSIBLY MAKING THIS MOVE. AT
ANY RATE...ANY LIGHT RAINFALL IN THE NORTHEAST...ESPECIALLY OF THE
POTENTIALLY MEASURABLE VARIETY...IS EXPECTED TO BE OUT OF THE
PICTURE BY NOON...AS THE MID LEVELS START TO DRY OUT FROM WEST TO
EAST. CLOUD-WISE...HAVE LEANED TOWARD A COMBINATION OF THE NAM AND
HRRR...WITH THE EXPECTATION OF A RATHER SHARP SOUTHWEST-NORTHEAST
GRADIENT RANGING FROM MOSTLY SUNNY-PARTLY CLOUDY SOUTHWEST TO
MOSTLY CLOUDY AT BEST IN THE NORTHEAST. SHAKY CONFIDENCE IN THESE
CLOUD DETAILS LEAD TO SOMEWHAT SHAKY CONFIDENCE IN HIGH TEMPS. AT
LEAST FOR NOW...NUDGED SOUTHWEST AREAS UP A FEW DEGREES AND
NORTHEAST AREAS DOWN A FEW DEGREES VERSUS PREVIOUS...WHILE LEAVING
THE CENTRAL RATHER UNCHANGED. AS A RESULT...AM AIMING FROM UPPER
50S-LOW 60S FAR NORTH/NORTHEAST TO MID 60S TRI-CITIES TO MID 70S
SOUTHWEST. HOWEVER...AM STARTING TO WONDER IF THE HRRR MIGHT BE
ONTO SOMETHING...KEEPING MUCH OF THE NORTHEAST 1/2 OF THE CWA WELL
DOWN IN THE MID-50S AT BEST UNDER THE LONGEST-LASTING STRATUS.
THIS WILL BEAR WATCHING FOR LATER UPDATES...BUT DON/T WANT TO GO
QUITE THIS COOL YET.
TURNING TO THE TONIGHT PERIOD...00Z-12Z...CONFIDENCE REMAINS
RATHER HIGH IN A LEGITIMATELY DRY NIGHT...WITH THE SOLE POSSIBLE
EXCEPTION OF SOME PATCHY LIGHT DRIZZLE IN THE EVENING IN THE NORTH
UNDER A LOW STRATUS DECK...BUT THIS SCENARIO IS TOO UNCERTAIN TO
INSERT AT THIS TIME. IN THE MID-UPPER LEVELS...THE DEPARTING LOW
FINALLY SLIPS FAR ENOUGH EAST TO ALLOW THE RIDGE TO THE WEST TO
START BUILDING INTO NEB/KS. ALTHOUGH THERE WILL BE A MODEST
NORTHWEST-SOUTHEAST ORIENTED WING OF MID LEVEL MOISTURE
ADVECTION/ISENTROPIC LIFT THAT SETS UP FROM SOUTHWEST NEB TO
SOUTHEAST KS MAINLY AFTER MIDNIGHT AS EVIDENT ON THE 310K
SURFACE...SOUNDINGS SUGGEST THAT LIFT/MOISTURE SHOULD BE
INSUFFICIENT FOR PRECIP OVER THE CWA...ALTHOUGH A FEW SHOWERS OR
EVEN WEAK STORMS COULD FLARE UP WITHIN A FEW COUNTIES JUST TO THE
SOUTH/SOUTHWEST BY SUNRISE. AT THE SURFACE...HIGH PRESSURE WILL
CONTINUE OOZING DOWN FROM THE NORTH...KEEPING FAIRLY LIGHT BUT
STEADY NORTHERLY BREEZES AROUND 10 MPH IN PLACE. DESPITE THE
PRESENCE OF POTENTIALLY DECENT LOW LEVEL SATURATION...THESE
BREEZES SHOULD KEEP ANYTHING MORE THAN HAZE/LIGHT FOG AT BAY. THE
REAL QUESTION MARK AT THIS POINT TONIGHT AGAIN LIES WITH LOW
STRATUS TRENDS. WHILE THE PREVIOUS FORECAST HAD NO WORSE THAN
PARTLY CLOUDY SKIES...THE LATEST NAM RUNS AND ASSOCIATED MET
GUIDANCE FAIRLY AGGRESSIVELY BRING A BATCH OF LOW STRATUS BACK
SOUTHWARD ACROSS MOST OF THE CWA AS THE NIGHT WEARS ON...WITH THIS
ESPECIALLY EVIDENT AT 900MB. FOR NOW...HAVE STARTED AN UPWARD
TREND IN SKY COVER...BUT VERY WELL MAY NOT BE HIGH ENOUGH
ESPECIALLY POST-MIDNIGHT. EVEN IF STRATUS DOES END UP BEING MORE
WIDESPREAD THAN CURRENTLY SUGGESTED...CONFIDENCE IS DECENT THAT
LOW TEMPS WILL END UP SIMILAR TO THOSE OF THIS MORNING...AND USED
A BLEND OF MET/MAV GUIDANCE...AIMING FOR ANOTHER COOL ONE WITH MID
40S MOST SPOTS.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 509 AM CDT WED MAY 22 2013
MODELS ARE IN GOOD AGREEMENT TRANSITIONING A RIDGE OF HIGH PRESSURE
ACROSS THE PLAINS ON THURSDAY IN WAKE OF THE DEPARTING UPPER LEVEL
LOW. WHILE HEIGHTS ALOFT WILL BE RISING...EXPECT ONLY A MODESTLY
WARMER AFTERNOON ON THURSDAY AS 850MB TEMPS ARE EXPECTED TO ONLY
REBOUND A COUPLE OF DEGREES AND PLENTY OF CLOUD COVER IS EXPECTED IN
EASTERLY UPSLOPE FLOW.
AS THE WINDS SHIFT MORE SOUTHEASTERLY THURSDAY NIGHT AND
FRIDAY...EXPECT ADDITIONAL MOISTURE TO SURGE NORTHWARD...AND FOR
INCREASING INSTABILITY ACROSS THE REGION. THIS BUILDING INSTABILITY
COMBINED WITH SOME FORCING FROM THE LOW LEVEL JET...WILL LIKELY
RESULT IN A CHANCE OF THUNDERSTORMS THURSDAY NIGHT ACROSS THE
SOUTHERN HALF OF THE FORECAST AREA...WHICH WILL BE IN CLOSER
PROXIMITY TO THE JET. WITH THE NOSE OF THE NOCTURNAL JET MORE
FOCUSED ACROSS THE HEART OF LOCAL AREA FRIDAY AND FRIDAY
NIGHT...CANNOT RULE OUT ADDITIONAL ELEVATED SHOWER AND THUNDERSTORM
ACTIVITY ACROSS THE ENTIRE FORECAST AREA...WITH THE BEST CHANCES FOR
PRECIPITATION COMING DURING THE LATE EVENING AND OVERNIGHT HOURS.
THEREAFTER THE MID LEVEL CAP IS EXPECTED TO WEAKEN SUBSTANTIALLY BY
SATURDAY AFTERNOON... AND WITH SEVERAL THOUSAND JOULES OF CAPE TO
WORK WITH THROUGH THE REMAINDER OF THE LONG TERM PERIODS...WILL
LIKELY SEE THUNDERSTORMS AROUND EACH DAY AS PERIODIC VORTICITY
MAXIMA EJECT OUT OF THE LONGWAVE TROUGH ACROSS THE WEST COAST.
ADDITIONALLY...WITH THESE SUBSTANTIAL CAPE VALUES AND MARGINALLY
SUPPORTIVE SHEAR PROFILES...WILL HAVE THE POTENTIAL FOR SOME SEVERE
THUNDERSTORMS DEVELOP FROM TIME TO TIME SATURDAY ONWARD...WITH LARGE
HAIL AND STRONG THUNDERSTORM WIND GUSTS BEING THE PRIMARY THREATS.
TEMPERATURES THROUGH THE PERIOD ARE NOT EXPECTED TO FLUCTUATE A
WHOLE LOT AS THERE WILL BE LITTLE CHANGE IN THE UNDERLYING AIRMASS
SATURDAY ONWARD...WITH LOWER TO MIDDLE 80S EXPECTED EACH AFTERNOON
AND LOWER 60S EXPECTED AT NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1248 PM CDT WED MAY 22 2013
MVFR CONDITIONS FORECAST THROUGH 20Z...VFR 20-02Z...THEN MVFR
CONDITIONS 02-15Z.
AS OF MIDDAY A STRATUS DECK...WITH A CEILING NEAR 2000FT
AGL...PERSISTS AT KGRI. THIS CEILING IS EXPECTED TO CONTINUE
THROUGH ANOTHER COUPLE HOURS...BUT IS THEN EXPECTED TO SCATTER OUT
BY MID AFTERNOON...THUS THE VFR FORECAST BEGINNING 20Z. VFR
CONDITIONS ARE THEN FORECAST THROUGH THIS EVENING...HOWEVER
GUIDANCE SUGGESTS AN MVFR DECK WILL ONCE AGAIN INFILTRATE THE AREA
THIS EVENING AND INTO THE OVERNIGHT HOURS. IT IS WORTH NOTING THAT
SOME GUIDANCE SUGGESTS IFR CEILINGS...OR LOWER...WILL BE REALIZED
TONIGHT THROUGH EARLY THURSDAY MORNING...BUT AT THIS TIME
CONFIDENCE IS NOT HIGH ENOUGH TO INSERT SUCH CONDITIONS IN THE
TAF. FUTURE SHIFTS WILL WANT TO CONTINUE MONITORING FOR THE
POSSIBLE INSERTION OF A LOWER CEILING IN FUTURE TAFS. WHAT CEILING
DOES DEVELOP OVERNIGHT TONIGHT SHOULD SCATTER OUT POST- SUNRISE
THURSDAY. THE SURFACE WIND WILL TRANSITION FROM THE NORTHWEST TO
MORE OF A NORTH/NORTHEAST DIRECTION THROUGH THE NEXT 24
HOURS...SUSTAINED AT AROUND 14KTS AND GUSTING NEAR 20KTS THROUGH
THIS EVENING. VISIBILITY RESTRICTION IS NOT CURRENTLY EXPECTED AT
KGRI THROUGH THE NEXT 24 HOURS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...PFANNKUCH
LONG TERM...SAR
AVIATION...BRYANT/BRUM
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
950 AM CDT WED MAY 22 2013
.UPDATE...
ISSUED AT 949 AM CDT WED MAY 22 2013
UPDATED THE FORECAST FOR TRENDS IN CLOUD COVER AND PRECIPITATION.
THE SURFACE LOW WHICH HAS THE MOISTURE ROTATING AROUND IT IS NOW
OVER NORTHEAST IOWA AS OF 14Z...WHILE HIGH PRESSURE BUILDS INTO
THE PANHANDLE AND WESTERN NEBRASKA. THE CLOUD COVER WAS STARTING
TO BREAK UP THIS MORNING...MAINLY OVER THE SOUTHWEST PARTS OF THE
FORECAST AREA. THERE IS A NARROW BAND FROM APPROXIMATELY KOGA TO
KCDR THAT MAY PERSIST A BIT LONGER...BUT EXPECTING THIS AREA TO
MIX OUT AND DISSIPATE BY THE NOON HOUR. GOING FURTHER EAST...THE
CLOUDS WILL LIKELY PERSIST THROUGH MUCH OF THE DAY...OR AT LEAST
THROUGH MID AFTERNOON AS A THICKER LAYER OF MOISTURE WILL REMAIN.
THE SHOWERS HAVE DECREASED IN AREA AND INTENSITY BY LATE THIS
MORNING...WITH THE STRONGER ECHOES NOW OVER EASTERN NEBRASKA AND
EASTERN SOUTH DAKOTA...CLOSER TO THE SURFACE LOW. WILL KEEP
MENTION OF SHOWERS AND SPRINKLES ACROSS NORTH CENTRAL AND CENTRAL
NEBRASKA THROUGH THE MORNING...THEN DRY CONDITIONS EXPECTED FOR
THE AFTERNOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CDT WED MAY 22 2013
WRAP AROUND CLOUDINESS WILL CONTINUE TODAY ACROSS NRN NEB. THE LIGHT
RAIN SHOULD END BY NOON. THERE IS ONE MORE IMPULSE ACROSS ERN SD
WHICH WILL DROP SOUTH BEFORE THE SFC LOW DRIFTS EAST INTO THE
MIDWEST THIS AFTERNOON. THIS LEAVES MUCH OF THE SRN HALF OF THE FCST
AREA IN PARTLY CLOUDY SKIES WITH HIGHS IN THE 60S WHILE OVERCAST
SKIES KEEP THE NORTH IN THE 50S.
TONIGHT...AN INVERTED SFC LOW PRESSURE TROF WILL SHARPEN UP ACROSS
THE NRN AND CNTL ROCKIES. THIS WILL SET UP A BROAD BELT OF
EASTERLIES ACROSS THE FCST AREA WHICH COULD TRAP LOW LEVEL MOISTURE
AND PRODUCE UPSLOPE FOG AND STRATUS ACROSS WRN NEB. PRESUMABLY...DRY
AIR COULD MOVE INTO NCNTL NEB CLEARING SKIES THERE. GIVEN THE POOR
MODEL PERFORMANCE OF THE NAM IN THESE TYPES OF SITUATIONS...THE RAP
MODEL MIGHT BE THE BEST HANDLE FOR TONIGHTS SKY FORECAST.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 345 AM CDT WED MAY 22 2013
SFC HIGH PRESSURE WILL MOVE EAST OF THE REGION THURSDAY...WITH EAST
TO SOUTHEAST WINDS KEEPING CONDITIONS RATHER COOL...WITH HIGHS IN
THE 60S TO PERHAPS 70 IN A FEW LOCALS. INCREASING LOW LEVEL MOISTURE
COULD LEAD TO SOME STRATUS DEVELOPMENT...ESPECIALLY ACROSS SOUTHWEST
NEB AND THE PANHANDLE...WHICH COULD HOLD HIGHS DOWN FURTHER. A
SOUTHERLY LLJ CRACKS UP TO AROUND 45 KTS...ADVECTING MORE MOISTURE
AND BETTER CHANCES FOR STRATUS CLOUDS INTO THE AREA. WILL MAINTAIN A
SLIGHT CHANCE FOR SHOWERS/TSTMS ACROSS SOUTHWEST NEBRASKA...WHERE
WARM AIR ADVECTION WILL BE MAXIMIZED.
FRIDAY THROUGH TUESDAY APPEARS TO BE QUITE ACTIVE IN TERMS OF
CONVECTIVE POTENTIAL. A LARGE UPPER LEVEL LOW PRESSURE SYSTEM WILL
BECOME ANCHORED ACROSS THE PACIFIC NORTHWEST...PROVIDING A SOUTHWEST
FLOW ALOFT ACROSS THE CENTRAL CONUS. THIS FLOW DOESN/T APPEAR OVERLY
STRONG...BUT ADEQUATE ENOUGH TO SUPPORT SOME SEVERE TSTM POTENTIAL
FROM TIME TO TIME. MEANWHILE...PLENTY OF LOW LEVEL MOISTURE AND
STEEP MID LEVEL LAPSE RATES...WILL RESULT IN STRONG INSTABILITY
DURING THE AFTERNOON AND EVENING HOURS. IT APPEARS THAT A LEEWARD
TROUGH/DRY LINE WILL BE ESTABLISHED EACH AFTERNOON ACROSS WESTERN
NEB/KS...AND COULD SERVE AS A FOCUS FOR CONVECTIVE INITIATION AS
SHORTWAVE TROUGHS EJECT EASTWARD FROM THE WESTERN UPPER LOW. OF
COURSE TIMING OF THESE TROUGHS WILL BE A FACTOR...AND LATER
FORECASTS WILL REFINE THE TIMING AND INTENSITY OF ANY TSTMS.
TEMPERATURES THROUGH THE PERIOD COULD BE A CHALLENGE...ESPECIALLY
HIGH TEMPERATURES...AS POTENTIAL EXISTS FOR QUITE A BIT IN THE WAY
OF STRATUS CLOUDS DUE TO INCREASED GULF OF MEXICO MOISTURE...AND ANY
CONVECTIVE DEBRIS CLOUDINESS. FOR NOW WILL GO WITH HIGHS MAINLY IN
THE LOWER 70S TO LOWER 80S...WITH THE WARMEST READINGS ACROSS THE
WESTERN PORTIONS OF THE AREA. LOWS WILL BE MILD...MID 50S TO LOWER
60S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 622 AM CDT WED MAY 22 2013
IFR ACROSS NRN NEB SHOULD IMPROVE TO MVFR THIS MORNING WHILE THE
MVFR ALONG I-80 IMPROVES TO VFR. TONIGHT...UPSLOPE EASTERLIES
DEVELOP AND MVFR/IFR IS EXPECTED TO REDEVELOP ACROSS WRN NEB
PERHAPS AFFECTING THE KLBF TERMINAL. MEANWHILE...THE RAP MODEL
SUGGESTS CLEARING ACROSS NERN NEB AND THE KVTN TERMINAL.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BROOKS
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
627 AM CDT WED MAY 22 2013
.UPDATE...
ISSUED AT 625 AM CDT WED MAY 22 2013
AS DISCUSSED EARLIER...ENDED UP MAKING A FEW ADJUSTMENTS TO VERY
SHORT TERM GRIDS BASED ON LATEST RADAR TRENDS...AND WITH SUPPORT
FROM THE LATEST RAP13/HRRR QPF/REFLECTIVITY. ALTHOUGH CANNOT RULE
OUT A FEW SPOTS REPORTING LIGHT MEASURABLE RAIN WITH THIS
ACTIVITY...ESPECIALLY IN THE NANCE/POLK COUNTY AREA...THINK THAT
NON-MEASURABLE SPRINKLES WILL BE THE DOMINANT STORY FOR MOST OF
THE AFFECTED AREA...AND THUS LEFT OUT A MEASURABLE POP.
HOWEVER...BEEFED UP SPRINKLE WORDING TO WIDESPREAD IN SEVERAL FAR
NORTHEAST COUNTIES THROUGH NOON 17Z...AND EXPANDED AN ISOLATED
SPRINKLE MENTION AS FAR SOUTH AS A LOUP CITY-GENEVA LINE. IT MAY
TURN OUT THAT THIS LIGHT PRECIP MAY BE OUT OF THE PICTURE WELL
BEFORE NOON...BUT GIVEN THE VERY SLOW MOVING NATURE OF THE PARENT
MID LEVEL LOW TO THE EAST ANYTHING IS POSSIBLE. ALSO BEEFED UP SKY
COVER PERCENTAGES FROM MOSTLY CLOUDY TO OUTRIGHT CLOUDY ACROSS
ROUGHLY THE NORTHEAST 1/2 OF THE CWA THROUGH MID-DAY...WHILE
LEAVING A MORE OPTIMISTIC TREND IN PLACE FARTHER SOUTHWEST. THE
LATEST HRRR IS NOW SPORTING A ROUGHLY 20 DEGREE HIGH-TEMP GRADIENT
ACROSS THE CWA THIS AFTERNOON FROM ONLY LOW-MID 50S NORTHEAST TO
MID 70S SOUTHWEST. OTHER SHORT TERM MODELS SUCH AS THE RAP13 ARE
NOT AS COOL IN THE NORTHEAST AS THE HRRR...AND THUS WILL RESIST
THE URGE TO MODIFY AFTERNOON HIGHS AT THIS TIME...BUT FOR SURE ITS
POSSIBLE THAT SOME NORTHEAST AREAS COULD STRUGGLE TO REACH THE
MID-UPPER 50S AND NEXT SHIFT WILL HAVE MONITOR TRENDS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 509 AM CDT WED MAY 22 2013
WHILE THERE IS CERTAINLY NO HIGH-IMPACT WEATHER DURING THE NEXT
24 HOURS...THERE ARE AT LEAST A FEW TRICKY ELEMENTS AT
HAND...INCLUDING THE EXTENT OF LOW STRATUS AND ITS POSSIBLE
INFLUENCE ON A FAIRLY DECENT SOUTHWEST-NORTHEAST TEMP
GRADIENT...AND ALSO THE EXTENT OF SPRINKLES/LIGHT RAIN SHOWERS
MAINLY THIS MORNING IN THE NORTHEAST.
08Z OBJECTIVE SURFACE ANALYSIS REVEALS NO MAJOR FEATURES ACROSS
THE CENTRAL PLAINS...WITH THE CWA POSITIONED BETWEEN A MODEST 1004
MILLIBAR LOW OVER EASTERN IA...AND A 1014MB HIGH OVER THE NEB
PANHANDLE...A SOUTHWARD EXTENSION OF A STRONGER...BROADER HIGH
WELL TO THE NORTH IN CANADA. WITHIN THE MODEST PRESSURE GRADIENT
BETWEEN THESE FEATURES...A FAIRLY STEADY NORTH-NORTHWEST BREEZE OF
10-15 MPH HAS PREVAILED THROUGH THE NIGH IN MOST AREAS...WITH
OCCASIONAL GUSTS OVER 20 MPH. TEMPERATURES WILL START OUT THE
MORNING SEASONABLY COOL...WITH EVENTUAL LOWS AIMED INTO THE MID-
UPPER 40S ALL AREAS. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM
MODEL DATA FEATURES A CLOSED 500MB LOW DRIFTING SLOWLY
EAST...CENTERED NEAR THE IA/SD/NEB BORDER...AND A FAIRLY SHARP MID
LEVEL TROUGH AXIS THEN TRAILING SOUTH-SOUTHEAST INTO THE MID-SOUTH
STATES. OFF TO THE WEST OF THE LOCAL AREA...A LOW AMPLITUDE MID
LEVEL RIDGE IS ALIGNED NORTH-SOUTH THROUGH THE ROCKIES...WITH A
FAIRLY VIGOROUS...EXPANSIVE CLOSED LOW SPINNING OVER THE PACIFIC
NORTHWEST. WHILE IT HAS TAKEN ITS TIME FORMING...11-3.9 MICRON
SATELLITE IMAGERY AND AUTOMATED OBS HAVE FINALLY REVEALED THE
FORMATION OF FAIRLY WIDESPREAD LOW STRATUS MAINLY IN THE 1500-2500
FT RANGE OVER MUCH OF THE CWA...ALTHOUGH SOME BREAKS IN THE CLOUDS
DO STILL EXIST. ALSO JUST WITHIN THE PAST 90 MINUTES OR SO...AN
INCREASING FLARE-UP OF LIGHT RAIN/SPRINKLES HAS TAKEN PLACE MAINLY
OVER THE FAR NORTHERN/NORTHEAST CWA...WITH UPSTREAM OBS AT PLACES
SUCH AS ONEILL AND ALBION CONFIRMING AT LEAST TRACE AMOUNTS ARE
FALLING.
TODAY...THE MAIN STORY ALOFT INVOLVES THE CONTINUED SLOW DEPARTURE
OF THE CLOSED MID LEVEL LOW...WITH THE CENTER OF THIS FEATURE
PROGGED TO ONLY REACH NORTHEAST IA BY 00Z. AT THE SURFACE...A
MODEST PRESSURE GRADIENT WILL REMAIN IN PLACE AS HIGH PRESSURE TO
THE NORTH NOSES SOUTHWARD...AND THIS IN COMBINATION WITH MIXING TO
AT LEAST 850MB IN MOST AREAS WILL RESULT IN SOMEWHAT BREEZY
CONDITIONS ESPECIALLY WITHIN THE NORTHEAST 2/3 OF THE CWA...WITH
SUSTAINED NORTHWEST WINDS 15 TO POSSIBLY 20 MPH...AND SOME HIGHER
GUSTS. THE REAL CHALLENGE TODAY LIES INITIALLY WITH THE EXTENT AND
INTENSITY OF RAINFALL...AND ALSO JUST HOW STUBBORN THE LOW STRATUS
DECK WILL BE...AND WHETHER OR NOT IT RETREATS SLOW NORTHEAST
DURING THE AFTERNOON. STARTING OUT EARLY THIS MORNING THROUGH MID-
DAY...HAVE INTRODUCED A MENTION OF SPRINKLES TO A PREVIOUSLY
PRECIP-FREE FORECAST FOR FAR NORTHEAST AREAS MAINLY NORTH OF A
GREELEY-POLK LINE...AS DECENT LOW-MID LEVEL SATURATION UP TO
AROUND 600MB RESIDES MAINLY IN THIS ZONE AND POINTS
NORTHEAST...ASSOCIATED WITH A BATCH OF MID LEVEL MOISTURE FOCUSED
IN THE DEFORMATION ZONE ON THE BACK-SIDE OF THE DEPARTING LOW. THE
VERY SHORT TERM QUESTION THAT WILL NEED PONDERED OVER THE NEXT FEW
HOURS IS WHETHER TO EXPAND THIS SPRINKLE MENTION SOUTHWESTWARD
CLOSER TO I-80 PER SUGGESTION OF THE LATEST HRRR REFLECTITY
PROG...AND ALSO WHETHER TO UP THE ANTE TO A MEASURABLE POP. WILL
GIVE IT SOME TIME TO SEE IF AREA OBSERVATIONS SUPPORT A FEW
HUNDREDTHS OF ACCUMULATIONS BEFORE POSSIBLY MAKING THIS MOVE. AT
ANY RATE...ANY LIGHT RAINFALL IN THE NORTHEAST...ESPECIALLY OF THE
POTENTIALLY MEASURABLE VARIETY...IS EXPECTED TO BE OUT OF THE
PICTURE BY NOON...AS THE MID LEVELS START TO DRY OUT FROM WEST TO
EAST. CLOUD-WISE...HAVE LEANED TOWARD A COMBINATION OF THE NAM AND
HRRR...WITH THE EXPECTATION OF A RATHER SHARP SOUTHWEST-NORTHEAST
GRADIENT RANGING FROM MOSTLY SUNNY-PARTLY CLOUDY SOUTHWEST TO
MOSTLY CLOUDY AT BEST IN THE NORTHEAST. SHAKY CONFIDENCE IN THESE
CLOUD DETAILS LEAD TO SOMEWHAT SHAKY CONFIDENCE IN HIGH TEMPS. AT
LEAST FOR NOW...NUDGED SOUTHWEST AREAS UP A FEW DEGREES AND
NORTHEAST AREAS DOWN A FEW DEGREES VERSUS PREVIOUS...WHILE LEAVING
THE CENTRAL RATHER UNCHANGED. AS A RESULT...AM AIMING FROM UPPER
50S-LOW 60S FAR NORTH/NORTHEAST TO MID 60S TRI-CITIES TO MID 70S
SOUTHWEST. HOWEVER...AM STARTING TO WONDER IF THE HRRR MIGHT BE
ONTO SOMETHING...KEEPING MUCH OF THE NORTHEAST 1/2 OF THE CWA WELL
DOWN IN THE MID-50S AT BEST UNDER THE LONGEST-LASTING STRATUS.
THIS WILL BEAR WATCHING FOR LATER UPDATES...BUT DON/T WANT TO GO
QUITE THIS COOL YET.
TURNING TO THE TONIGHT PERIOD...00Z-12Z...CONFIDENCE REMAINS
RATHER HIGH IN A LEGITIMATELY DRY NIGHT...WITH THE SOLE POSSIBLE
EXCEPTION OF SOME PATCHY LIGHT DRIZZLE IN THE EVENING IN THE NORTH
UNDER A LOW STRATUS DECK...BUT THIS SCENARIO IS TOO UNCERTAIN TO
INSERT AT THIS TIME. IN THE MID-UPPER LEVELS...THE DEPARTING LOW
FINALLY SLIPS FAR ENOUGH EAST TO ALLOW THE RIDGE TO THE WEST TO
START BUILDING INTO NEB/KS. ALTHOUGH THERE WILL BE A MODEST
NORTHWEST-SOUTHEAST ORIENTED WING OF MID LEVEL MOISTURE
ADVECTION/ISENTROPIC LIFT THAT SETS UP FROM SOUTHWEST NEB TO
SOUTHEAST KS MAINLY AFTER MIDNIGHT AS EVIDENT ON THE 310K
SURFACE...SOUNDINGS SUGGEST THAT LIFT/MOISTURE SHOULD BE
INSUFFICIENT FOR PRECIP OVER THE CWA...ALTHOUGH A FEW SHOWERS OR
EVEN WEAK STORMS COULD FLARE UP WITHIN A FEW COUNTIES JUST TO THE
SOUTH/SOUTHWEST BY SUNRISE. AT THE SURFACE...HIGH PRESSURE WILL
CONTINUE OOZING DOWN FROM THE NORTH...KEEPING FAIRLY LIGHT BUT
STEADY NORTHERLY BREEZES AROUND 10 MPH IN PLACE. DESPITE THE
PRESENCE OF POTENTIALLY DECENT LOW LEVEL SATURATION...THESE
BREEZES SHOULD KEEP ANYTHING MORE THAN HAZE/LIGHT FOG AT BAY. THE
REAL QUESTION MARK AT THIS POINT TONIGHT AGAIN LIES WITH LOW
STRATUS TRENDS. WHILE THE PREVIOUS FORECAST HAD NO WORSE THAN
PARTLY CLOUDY SKIES...THE LATEST NAM RUNS AND ASSOCIATED MET
GUIDANCE FAIRLY AGGRESSIVELY BRING A BATCH OF LOW STRATUS BACK
SOUTHWARD ACROSS MOST OF THE CWA AS THE NIGHT WEARS ON...WITH THIS
ESPECIALLY EVIDENT AT 900MB. FOR NOW...HAVE STARTED AN UPWARD
TREND IN SKY COVER...BUT VERY WELL MAY NOT BE HIGH ENOUGH
ESPECIALLY POST-MIDNIGHT. EVEN IF STRATUS DOES END UP BEING MORE
WIDESPREAD THAN CURRENTLY SUGGESTED...CONFIDENCE IS DECENT THAT
LOW TEMPS WILL END UP SIMILAR TO THOSE OF THIS MORNING...AND USED
A BLEND OF MET/MAV GUIDANCE...AIMING FOR ANOTHER COOL ONE WITH MID
40S MOST SPOTS.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 509 AM CDT WED MAY 22 2013
MODELS ARE IN GOOD AGREEMENT TRANSITIONING A RIDGE OF HIGH PRESSURE
ACROSS THE PLAINS ON THURSDAY IN WAKE OF THE DEPARTING UPPER LEVEL
LOW. WHILE HEIGHTS ALOFT WILL BE RISING...EXPECT ONLY A MODESTLY
WARMER AFTERNOON ON THURSDAY AS 850MB TEMPS ARE EXPECTED TO ONLY
REBOUND A COUPLE OF DEGREES AND PLENTY OF CLOUD COVER IS EXPECTED IN
EASTERLY UPSLOPE FLOW.
AS THE WINDS SHIFT MORE SOUTHEASTERLY THURSDAY NIGHT AND
FRIDAY...EXPECT ADDITIONAL MOISTURE TO SURGE NORTHWARD...AND FOR
INCREASING INSTABILITY ACROSS THE REGION. THIS BUILDING INSTABILITY
COMBINED WITH SOME FORCING FROM THE LOW LEVEL JET...WILL LIKELY
RESULT IN A CHANCE OF THUNDERSTORMS THURSDAY NIGHT ACROSS THE
SOUTHERN HALF OF THE FORECAST AREA...WHICH WILL BE IN CLOSER
PROXIMITY TO THE JET. WITH THE NOSE OF THE NOCTURNAL JET MORE
FOCUSED ACROSS THE HEART OF LOCAL AREA FRIDAY AND FRIDAY
NIGHT...CANNOT RULE OUT ADDITIONAL ELEVATED SHOWER AND THUNDERSTORM
ACTIVITY ACROSS THE ENTIRE FORECAST AREA...WITH THE BEST CHANCES FOR
PRECIPITATION COMING DURING THE LATE EVENING AND OVERNIGHT HOURS.
THEREAFTER THE MID LEVEL CAP IS EXPECTED TO WEAKEN SUBSTANTIALLY BY
SATURDAY AFTERNOON... AND WITH SEVERAL THOUSAND JOULES OF CAPE TO
WORK WITH THROUGH THE REMAINDER OF THE LONG TERM PERIODS...WILL
LIKELY SEE THUNDERSTORMS AROUND EACH DAY AS PERIODIC VORTICITY
MAXIMA EJECT OUT OF THE LONGWAVE TROUGH ACROSS THE WEST COAST.
ADDITIONALLY...WITH THESE SUBSTANTIAL CAPE VALUES AND MARGINALLY
SUPPORTIVE SHEAR PROFILES...WILL HAVE THE POTENTIAL FOR SOME SEVERE
THUNDERSTORMS DEVELOP FROM TIME TO TIME SATURDAY ONWARD...WITH LARGE
HAIL AND STRONG THUNDERSTORM WIND GUSTS BEING THE PRIMARY THREATS.
TEMPERATURES THROUGH THE PERIOD ARE NOT EXPECTED TO FLUCTUATE A
WHOLE LOT AS THERE WILL BE LITTLE CHANGE IN THE UNDERLYING AIRMASS
SATURDAY ONWARD...WITH LOWER TO MIDDLE 80S EXPECTED EACH AFTERNOON
AND LOWER 60S EXPECTED AT NIGHT.
&&
.AVIATION...(FOR THE 12Z KGRI TAF THROUGH 12Z THURSDAY MORNING)
ISSUED AT 625 AM CDT WED MAY 22 2013
ALTHOUGH CONFIDENCE IS HIGH IN VFR VISIBILITY THROUGH THE
PERIOD...CEILING TRENDS CONTINUE TO BE TRICKY AS PLENTY OF LOWER
STRATUS HANGS AROUND THE AREA ON THE BACK SIDE OF A DEPARTING MID
LEVEL LOW. STARTING OFF THROUGH THE MORNING INTO THE MID-AFTERNOON
HOURS...HAVE CONTINUED A PREVAILING MVFR CEILING...ALTHOUGH JUST
WITHIN THE PAST HOUR CLOUDS AT THE MVFR LEVEL HAVE SCATTERED A
BIT...DIMINISHING CONFIDENCE SOMEWHAT AND SUGGESTING THAT MVFR
MAY BE MORE OFF-AND-ON. ALSO THIS MORNING...A FEW SPRINKLES CANNOT
BE RULED OUT AT KGRI...BUT GIVEN SUCH LOW IMPACT WILL OMIT ANY
PRECIP MENTION. THROUGH THE LATE AFTERNOON AND EVENING
HOURS...KEPT TREND FROM PREVIOUS FORECAST BY RAISING PREVAILING
CEILING TO LOW-END VFR. HOWEVER...CONFIDENCE IN THE DETAILS REALLY
DECREASES BY THE LAST 6 HOURS OR SO LATE TONIGHT...AS SOME
MODELS/GUIDANCE SUGGEST A LOW-MVFR AND POSSIBLY EVEN IFR DECK
COULD MATERIALIZE...WHILE OTHER MODELS KEEP CEILING VFR. AS A
COMPROMISE BETWEEN THE WIDE POSSIBILITIES AT THIS TIME
RANGE...WILL INTRODUCE A SCATTERED LOW-END MVFR CLOUD GROUP.
WIND-WISE...A STEADY NORTH-NORTHWEST BREEZE WILL PREVAIL MUCH OF
THE DAY WITH GUST POTENTIAL TO AROUND 22KT...BEFORE SLACKENING THIS
EVENING AND AVERAGING UNDER 10KT OVERNIGHT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...PFANNKUCH
LONG TERM...SAR
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
625 AM CDT WED MAY 22 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CDT WED MAY 22 2013
WRAP AROUND CLOUDINESS WILL CONTINUE TODAY ACROSS NRN NEB. THE LIGHT
RAIN SHOULD END BY NOON. THERE IS ONE MORE IMPULSE ACROSS ERN SD
WHICH WILL DROP SOUTH BEFORE THE SFC LOW DRIFTS EAST INTO THE
MIDWEST THIS AFTERNOON. THIS LEAVES MUCH OF THE SRN HALF OF THE FCST
AREA IN PARTLY CLOUDY SKIES WITH HIGHS IN THE 60S WHILE OVERCAST
SKIES KEEP THE NORTH IN THE 50S.
TONIGHT...AN INVERTED SFC LOW PRESSURE TROF WILL SHARPEN UP ACROSS
THE NRN AND CNTL ROCKIES. THIS WILL SET UP A BROAD BELT OF
EASTERLIES ACROSS THE FCST AREA WHICH COULD TRAP LOW LEVEL MOISTURE
AND PRODUCE UPSLOPE FOG AND STRATUS ACROSS WRN NEB. PRESUMABLY...DRY
AIR COULD MOVE INTO NCNTL NEB CLEARING SKIES THERE. GIVEN THE POOR
MODEL PERFORMANCE OF THE NAM IN THESE TYPES OF SITUATIONS...THE RAP
MODEL MIGHT BE THE BEST HANDLE FOR TONIGHTS SKY FORECAST.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 345 AM CDT WED MAY 22 2013
SFC HIGH PRESSURE WILL MOVE EAST OF THE REGION THURSDAY...WITH EAST
TO SOUTHEAST WINDS KEEPING CONDITIONS RATHER COOL...WITH HIGHS IN
THE 60S TO PERHAPS 70 IN A FEW LOCALS. INCREASING LOW LEVEL MOISTURE
COULD LEAD TO SOME STRATUS DEVELOPMENT...ESPECIALLY ACROSS SOUTHWEST
NEB AND THE PANHANDLE...WHICH COULD HOLD HIGHS DOWN FURTHER. A
SOUTHERLY LLJ CRACKS UP TO AROUND 45 KTS...ADVECTING MORE MOISTURE
AND BETTER CHANCES FOR STRATUS CLOUDS INTO THE AREA. WILL MAINTAIN A
SLIGHT CHANCE FOR SHOWERS/TSTMS ACROSS SOUTHWEST NEBRASKA...WHERE
WARM AIR ADVECTION WILL BE MAXIMIZED.
FRIDAY THROUGH TUESDAY APPEARS TO BE QUITE ACTIVE IN TERMS OF
CONVECTIVE POTENTIAL. A LARGE UPPER LEVEL LOW PRESSURE SYSTEM WILL
BECOME ANCHORED ACROSS THE PACIFIC NORTHWEST...PROVIDING A SOUTHWEST
FLOW ALOFT ACROSS THE CENTRAL CONUS. THIS FLOW DOESN/T APPEAR OVERLY
STRONG...BUT ADEQUATE ENOUGH TO SUPPORT SOME SEVERE TSTM POTENTIAL
FROM TIME TO TIME. MEANWHILE...PLENTY OF LOW LEVEL MOISTURE AND
STEEP MID LEVEL LAPSE RATES...WILL RESULT IN STRONG INSTABILITY
DURING THE AFTERNOON AND EVENING HOURS. IT APPEARS THAT A LEEWARD
TROUGH/DRY LINE WILL BE ESTABLISHED EACH AFTERNOON ACROSS WESTERN
NEB/KS...AND COULD SERVE AS A FOCUS FOR CONVECTIVE INITIATION AS
SHORTWAVE TROUGHS EJECT EASTWARD FROM THE WESTERN UPPER LOW. OF
COURSE TIMING OF THESE TROUGHS WILL BE A FACTOR...AND LATER
FORECASTS WILL REFINE THE TIMING AND INTENSITY OF ANY TSTMS.
TEMPERATURES THROUGH THE PERIOD COULD BE A CHALLENGE...ESPECIALLY
HIGH TEMPERATURES...AS POTENTIAL EXISTS FOR QUITE A BIT IN THE WAY
OF STRATUS CLOUDS DUE TO INCREASED GULF OF MEXICO MOISTURE...AND ANY
CONVECTIVE DEBRIS CLOUDINESS. FOR NOW WILL GO WITH HIGHS MAINLY IN
THE LOWER 70S TO LOWER 80S...WITH THE WARMEST READINGS ACROSS THE
WESTERN PORTIONS OF THE AREA. LOWS WILL BE MILD...MID 50S TO LOWER
60S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 622 AM CDT WED MAY 22 2013
IFR ACROSS NRN NEB SHOULD IMPROVE TO MVFR THIS MORNING WHILE THE
MVFR ALONG I-80 IMPROVES TO VFR. TONIGHT...UPSLOPE EASTERLIES
DEVELOP AND MVFR/IFR IS EXPECTED TO REDEVELOP ACROSS WRN NEB
PERHAPS AFFECTING THE KLBF TERMAINAL. MEANWHILE...THE RAP MODEL
SUGGESTS CLEARING ACROSS NERN NEB AND THE KVTN TERMINAL.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
510 AM CDT WED MAY 22 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 509 AM CDT WED MAY 22 2013
WHILE THERE IS CERTAINLY NO HIGH-IMPACT WEATHER DURING THE NEXT
24 HOURS...THERE ARE AT LEAST A FEW TRICKY ELEMENTS AT
HAND...INCLUDING THE EXTENT OF LOW STRATUS AND ITS POSSIBLE
INFLUENCE ON A FAIRLY DECENT SOUTHWEST-NORTHEAST TEMP
GRADIENT...AND ALSO THE EXTENT OF SPRINKLES/LIGHT RAIN SHOWERS
MAINLY THIS MORNING IN THE NORTHEAST.
08Z OBJECTIVE SURFACE ANALYSIS REVEALS NO MAJOR FEATURES ACROSS
THE CENTRAL PLAINS...WITH THE CWA POSITIONED BETWEEN A MODEST 1004
MILLIBAR LOW OVER EASTERN IA...AND A 1014MB HIGH OVER THE NEB
PANHANDLE...A SOUTHWARD EXTENSION OF A STRONGER...BROADER HIGH
WELL TO THE NORTH IN CANADA. WITHIN THE MODEST PRESSURE GRADIENT
BETWEEN THESE FEATURES...A FAIRLY STEADY NORTH-NORTHWEST BREEZE OF
10-15 MPH HAS PREVAILED THROUGH THE NIGH IN MOST AREAS...WITH
OCCASIONAL GUSTS OVER 20 MPH. TEMPERATURES WILL START OUT THE
MORNING SEASONABLY COOL...WITH EVENTUAL LOWS AIMED INTO THE MID-
UPPER 40S ALL AREAS. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM
MODEL DATA FEATURES A CLOSED 500MB LOW DRIFTING SLOWLY
EAST...CENTERED NEAR THE IA/SD/NEB BORDER...AND A FAIRLY SHARP MID
LEVEL TROUGH AXIS THEN TRAILING SOUTH-SOUTHEAST INTO THE MID-SOUTH
STATES. OFF TO THE WEST OF THE LOCAL AREA...A LOW AMPLITUDE MID
LEVEL RIDGE IS ALIGNED NORTH-SOUTH THROUGH THE ROCKIES...WITH A
FAIRLY VIGOROUS...EXPANSIVE CLOSED LOW SPINNING OVER THE PACIFIC
NORTHWEST. WHILE IT HAS TAKEN ITS TIME FORMING...11-3.9 MICRON
SATELLITE IMAGERY AND AUTOMATED OBS HAVE FINALLY REVEALED THE
FORMATION OF FAIRLY WIDESPREAD LOW STRATUS MAINLY IN THE 1500-2500
FT RANGE OVER MUCH OF THE CWA...ALTHOUGH SOME BREAKS IN THE CLOUDS
DO STILL EXIST. ALSO JUST WITHIN THE PAST 90 MINUTES OR SO...AN
INCREASING FLARE-UP OF LIGHT RAIN/SPRINKLES HAS TAKEN PLACE MAINLY
OVER THE FAR NORTHERN/NORTHEAST CWA...WITH UPSTREAM OBS AT PLACES
SUCH AS ONEILL AND ALBION CONFIRMING AT LEAST TRACE AMOUNTS ARE
FALLING.
TODAY...THE MAIN STORY ALOFT INVOLVES THE CONTINUED SLOW DEPARTURE
OF THE CLOSED MID LEVEL LOW...WITH THE CENTER OF THIS FEATURE
PROGGED TO ONLY REACH NORTHEAST IA BY 00Z. AT THE SURFACE...A
MODEST PRESSURE GRADIENT WILL REMAIN IN PLACE AS HIGH PRESSURE TO
THE NORTH NOSES SOUTHWARD...AND THIS IN COMBINATION WITH MIXING TO
AT LEAST 850MB IN MOST AREAS WILL RESULT IN SOMEWHAT BREEZY
CONDITIONS ESPECIALLY WITHIN THE NORTHEAST 2/3 OF THE CWA...WITH
SUSTAINED NORTHWEST WINDS 15 TO POSSIBLY 20 MPH...AND SOME HIGHER
GUSTS. THE REAL CHALLENGE TODAY LIES INITIALLY WITH THE EXTENT AND
INTENSITY OF RAINFALL...AND ALSO JUST HOW STUBBORN THE LOW STRATUS
DECK WILL BE...AND WHETHER OR NOT IT RETREATS SLOW NORTHEAST
DURING THE AFTERNOON. STARTING OUT EARLY THIS MORNING THROUGH MID-
DAY...HAVE INTRODUCED A MENTION OF SPRINKLES TO A PREVIOUSLY
PRECIP-FREE FORECAST FOR FAR NORTHEAST AREAS MAINLY NORTH OF A
GREELEY-POLK LINE...AS DECENT LOW-MID LEVEL SATURATION UP TO
AROUND 600MB RESIDES MAINLY IN THIS ZONE AND POINTS
NORTHEAST...ASSOCIATED WITH A BATCH OF MID LEVEL MOISTURE FOCUSED
IN THE DEFORMATION ZONE ON THE BACK-SIDE OF THE DEPARTING LOW. THE
VERY SHORT TERM QUESTION THAT WILL NEED PONDERED OVER THE NEXT FEW
HOURS IS WHETHER TO EXPAND THIS SPRINKLE MENTION SOUTHWESTWARD
CLOSER TO I-80 PER SUGGESTION OF THE LATEST HRRR REFLECTITY
PROG...AND ALSO WHETHER TO UP THE ANTE TO A MEASURABLE POP. WILL
GIVE IT SOME TIME TO SEE IF AREA OBSERVATIONS SUPPORT A FEW
HUNDREDTHS OF ACCUMULATIONS BEFORE POSSIBLY MAKING THIS MOVE. AT
ANY RATE...ANY LIGHT RAINFALL IN THE NORTHEAST...ESPECIALLY OF THE
POTENTIALLY MEASURABLE VARIETY...IS EXPECTED TO BE OUT OF THE
PICTURE BY NOON...AS THE MID LEVELS START TO DRY OUT FROM WEST TO
EAST. CLOUD-WISE...HAVE LEANED TOWARD A COMBINATION OF THE NAM AND
HRRR...WITH THE EXPECTATION OF A RATHER SHARP SOUTHWEST-NORTHEAST
GRADIENT RANGING FROM MOSTLY SUNNY-PARTLY CLOUDY SOUTHWEST TO
MOSTLY CLOUDY AT BEST IN THE NORTHEAST. SHAKY CONFIDENCE IN THESE
CLOUD DETAILS LEAD TO SOMEWHAT SHAKY CONFIDENCE IN HIGH TEMPS. AT
LEAST FOR NOW...NUDGED SOUTHWEST AREAS UP A FEW DEGREES AND
NORTHEAST AREAS DOWN A FEW DEGREES VERSUS PREVIOUS...WHILE LEAVING
THE CENTRAL RATHER UNCHANGED. AS A RESULT...AM AIMING FROM UPPER
50S-LOW 60S FAR NORTH/NORTHEAST TO MID 60S TRI-CITIES TO MID 70S
SOUTHWEST. HOWEVER...AM STARTING TO WONDER IF THE HRRR MIGHT BE
ONTO SOMETHING...KEEPING MUCH OF THE NORTHEAST 1/2 OF THE CWA WELL
DOWN IN THE MID-50S AT BEST UNDER THE LONGEST-LASTING STRATUS.
THIS WILL BEAR WATCHING FOR LATER UPDATES...BUT DON/T WANT TO GO
QUITE THIS COOL YET.
TURNING TO THE TONIGHT PERIOD...00Z-12Z...CONFIDENCE REMAINS
RATHER HIGH IN A LEGITIMATELY DRY NIGHT...WITH THE SOLE POSSIBLE
EXCEPTION OF SOME PATCHY LIGHT DRIZZLE IN THE EVENING IN THE NORTH
UNDER A LOW STRATUS DECK...BUT THIS SCENARIO IS TOO UNCERTAIN TO
INSERT AT THIS TIME. IN THE MID-UPPER LEVELS...THE DEPARTING LOW
FINALLY SLIPS FAR ENOUGH EAST TO ALLOW THE RIDGE TO THE WEST TO
START BUILDING INTO NEB/KS. ALTHOUGH THERE WILL BE A MODEST
NORTHWEST-SOUTHEAST ORIENTED WING OF MID LEVEL MOISTURE
ADVECTION/ISENTROPIC LIFT THAT SETS UP FROM SOUTHWEST NEB TO
SOUTHEAST KS MAINLY AFTER MIDNIGHT AS EVIDENT ON THE 310K
SURFACE...SOUNDINGS SUGGEST THAT LIFT/MOISTURE SHOULD BE
INSUFFICIENT FOR PRECIP OVER THE CWA...ALTHOUGH A FEW SHOWERS OR
EVEN WEAK STORMS COULD FLARE UP WITHIN A FEW COUNTIES JUST TO THE
SOUTH/SOUTHWEST BY SUNRISE. AT THE SURFACE...HIGH PRESSURE WILL
CONTINUE OOZING DOWN FROM THE NORTH...KEEPING FAIRLY LIGHT BUT
STEADY NORTHERLY BREEZES AROUND 10 MPH IN PLACE. DESPITE THE
PRESENCE OF POTENTIALLY DECENT LOW LEVEL SATURATION...THESE
BREEZES SHOULD KEEP ANYTHING MORE THAN HAZE/LIGHT FOG AT BAY. THE
REAL QUESTION MARK AT THIS POINT TONIGHT AGAIN LIES WITH LOW
STRATUS TRENDS. WHILE THE PREVIOUS FORECAST HAD NO WORSE THAN
PARTLY CLOUDY SKIES...THE LATEST NAM RUNS AND ASSOCIATED MET
GUIDANCE FAIRLY AGGRESSIVELY BRING A BATCH OF LOW STRATUS BACK
SOUTHWARD ACROSS MOST OF THE CWA AS THE NIGHT WEARS ON...WITH THIS
ESPECIALLY EVIDENT AT 900MB. FOR NOW...HAVE STARTED AN UPWARD
TREND IN SKY COVER...BUT VERY WELL MAY NOT BE HIGH ENOUGH
ESPECIALLY POST-MIDNIGHT. EVEN IF STRATUS DOES END UP BEING MORE
WIDESPREAD THAN CURRENTLY SUGGESTED...CONFIDENCE IS DECENT THAT
LOW TEMPS WILL END UP SIMILAR TO THOSE OF THIS MORNING...AND USED
A BLEND OF MET/MAV GUIDANCE...AIMING FOR ANOTHER COOL ONE WITH MID
40S MOST SPOTS.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 509 AM CDT WED MAY 22 2013
MODELS ARE IN GOOD AGREEMENT TRANSITIONING A RIDGE OF HIGH PRESSURE
ACROSS THE PLAINS ON THURSDAY IN WAKE OF THE DEPARTING UPPER LEVEL
LOW. WHILE HEIGHTS ALOFT WILL BE RISING...EXPECT ONLY A MODESTLY
WARMER AFTERNOON ON THURSDAY AS 850MB TEMPS ARE EXPECTED TO ONLY
REBOUND A COUPLE OF DEGREES AND PLENTY OF CLOUD COVER IS EXPECTED IN
EASTERLY UPSLOPE FLOW.
AS THE WINDS SHIFT MORE SOUTHEASTERLY THURSDAY NIGHT AND
FRIDAY...EXPECT ADDITIONAL MOISTURE TO SURGE NORTHWARD...AND FOR
INCREASING INSTABILITY ACROSS THE REGION. THIS BUILDING INSTABILITY
COMBINED WITH SOME FORCING FROM THE LOW LEVEL JET...WILL LIKELY
RESULT IN A CHANCE OF THUNDERSTORMS THURSDAY NIGHT ACROSS THE
SOUTHERN HALF OF THE FORECAST AREA...WHICH WILL BE IN CLOSER
PROXIMITY TO THE JET. WITH THE NOSE OF THE NOCTURNAL JET MORE
FOCUSED ACROSS THE HEART OF LOCAL AREA FRIDAY AND FRIDAY
NIGHT...CANNOT RULE OUT ADDITIONAL ELEVATED SHOWER AND THUNDERSTORM
ACTIVITY ACROSS THE ENTIRE FORECAST AREA...WITH THE BEST CHANCES FOR
PRECIPITATION COMING DURING THE LATE EVENING AND OVERNIGHT HOURS.
THEREAFTER THE MID LEVEL CAP IS EXPECTED TO WEAKEN SUBSTANTIALLY BY
SATURDAY AFTERNOON... AND WITH SEVERAL THOUSAND JOULES OF CAPE TO
WORK WITH THROUGH THE REMAINDER OF THE LONG TERM PERIODS...WILL
LIKELY SEE THUNDERSTORMS AROUND EACH DAY AS PERIODIC VORTICITY
MAXIMA EJECT OUT OF THE LONGWAVE TROUGH ACROSS THE WEST COAST.
ADDITIONALLY...WITH THESE SUBSTANTIAL CAPE VALUES AND MARGINALLY
SUPPORTIVE SHEAR PROFILES...WILL HAVE THE POTENTIAL FOR SOME SEVERE
THUNDERSTORMS DEVELOP FROM TIME TO TIME SATURDAY ONWARD...WITH LARGE
HAIL AND STRONG THUNDERSTORM WIND GUSTS BEING THE PRIMARY THREATS.
TEMPERATURES THROUGH THE PERIOD ARE NOT EXPECTED TO FLUCTUATE A
WHOLE LOT AS THERE WILL BE LITTLE CHANGE IN THE UNDERLYING AIRMASS
SATURDAY ONWARD...WITH LOWER TO MIDDLE 80S EXPECTED EACH AFTERNOON
AND LOWER 60S EXPECTED AT NIGHT.
&&
.AVIATION...(FOR THE 06Z KGRI TAF THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1250 AM CDT WED MAY 22 2013
ALTHOUGH CONFIDENCE IS HIGH IN VFR VISIBILITY THROUGH THE
PERIOD...ALONG WITH LITTLE IF ANY RISK OF PRECIPITATION...CEILING
TRENDS APPEAR TO BE SOMEWHAT TRICKY AS PLENTY OF LOWER STRATUS
HANGS AROUND THE AREA ON THE BACK SIDE OF A DEPARTING MID LEVEL
LOW. STARTING OFF EARLY THIS MORNING...HAVE CONTINUED TO DELAY THE
ONSET OF PREVAILING MVFR CEILING UNTIL 09Z...ALTHOUGH AT LEAST
BRIEF INSTANCES OF MVFR MAY BE OBSERVED BEFORE THEN. LEANING
HEAVILY TOWARD LATEST CEILING TRENDS FROM 00Z NAM AND 05Z GFS LAMP
GUIDANCE...KEPT A BROKEN MVFR DECK IN PLACE THROUGH MID-
AFTERNOON...WHICH IS SEVERAL HOURS LATER THAN PREVIOUS FORECAST
INDICATED. CONFIDENCE STARTS TO WANE ESPECIALLY DURING THE FINAL 9
HOURS OR SO...BUT FOR NOW WILL AIM FOR A RETURN TO AT LEAST LOW-
END VFR CEILING BY LATE AFTERNOON. WILL CONTINUE THIS LOW-END VFR
THROUGH THE EVENING HOURS...BUT ITS WORTH NOTING THAT THE LATEST
NAM/MET GUIDANCE ACTUALLY RE-ESTABLISHES A SOLID MVFR DECK AFTER
SUNSET...SO THIS TREND WILL BEAR WATCHING. WIND-WISE...A STEADY
NORTH-NORTHWEST BREEZE WILL PREVAIL...WITH GUST POTENTIAL OF
18-22KT THROUGH LATE AFTERNOON BEFORE SLACKENING SOMEWHAT DURING
THE EVENING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...SAR
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
730 AM EDT WED MAY 22 2013
.SYNOPSIS...
MOSTLY CLOUDY SKIES ARE EXPECTED ACROSS THE NORTH COUNTRY TODAY.
A WARM FRONT LIFTING NORTHEASTWARD ACROSS THE REGION LATE THIS
AFTERNOON AND EVENING WILL BRING THE POTENTIAL FOR ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS. SOME THUNDERSTORMS MAY
PRODUCE SMALL HAIL...GUSTY WINDS...AND LOCALLY HEAVY DOWNPOURS. A
SLOW-MOVING COLD FRONT WILL THEN APPROACH FROM THE EASTERN GREAT
LAKES REGION BRINGING ADDITIONAL WIDESPREAD RAINFALL AND EMBEDDED
THUNDERSTORMS DURING THURSDAY AND THURSDAY NIGHT. WHILE IT WON/T
BE RAINING CONTINUOUSLY...PERIODS OF BRIEFLY HEAVY RAIN ASSOCIATED
WITH THE SHOWERS AND THUNDERSTORMS WILL GENERALLY BRING AN
ADDITIONAL 1 TO 2 INCHES OF RAIN ACROSS THE NORTH COUNTRY THROUGH
THURSDAY NIGHT. SOME MINOR FLOODING WILL BE POSSIBLE...MAINLY
THURSDAY INTO THURSDAY NIGHT WITH THE MOST WIDESPREAD RAINFALL.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AS OF 722 AM EDT WEDNESDAY...UNSETTLED PATTERN CONTINUES ACROSS THE
NORTH COUNTRY IN VCNTY OF E-W ORIENTED FRONTAL ZONE WHICH REMAINS
DRAPED ACROSS THE REGION. SFC TROUGH AND 850MB TEMP GRADIENT
SUGGESTS SYNOPTIC FRONTAL ZONE IS UP NEAR THE INTL BORDER...BUT
GIVEN THE WIDESPREAD CONVECTION THAT HAS OCCURRED IN SEVERAL WAVES
DURING THE PAST 6-12 HOURS...THE EFFECTIVE FRONTAL POSITION
EXTENDS ACROSS THE SRN TIER OF NY INTO NWRN CT WHERE LARGE
MESOSCALE COLD POOL HAS BEEN ESTABLISHED.
WILL SEE PATCHY FOG ACROSS THE REGION THRU 13Z GIVEN SATURATED
LOW-LEVEL CONDITIONS AND GENERALLY LIGHT WINDS. WEAK SFC LOW
ACROSS NRN NY WILL GENERALLY DISSIPATE THRU THE REMAINDER OF THIS
MORNING. THERE ARE SLIGHT 700-500MB HEIGHT RISES THIS MORNING THRU
EARLY AFTN...AND ABSENCE OF LOW-LEVEL CONVERGENCE SUGGESTS
ADDITIONAL RAINFALL IS UNLIKELY THRU ABOUT 19Z. CLOUDS BUT NO PCPN
THRU MID AFTN...WILL TREND SKY COVER FROM OVC TO BKN BY NOONTIME.
THEREAFTER...THERE IS A SWLY BACKING AND STRENGTHENING OF 850MB
FLOW ACROSS WRN PA INTO CENTRAL NY PER MODEL GUIDANCE. FEEL THAT
REMNANT OUTFLOW BOUNDARY ACROSS CENTRAL NY WILL ENHANCE ISENTROPIC
ASCENT LATE IN THE DAY ACROSS THE ADIRONDACKS AND S-CENTRAL
VT...ALLOWING FOR DEVELOPMENT OF SHOWER AND TSTM ACTIVITY. THE 00Z
NAM SHOWS DEVELOPMENT OF MUCAPE OF 500-1000 J/KG ACROSS ALL BUT
NERN PORTION OF THE FORECAST AREA 21-00Z. RAP SOUNDINGS SHOW A BIT
MORE INSTABILITY...UP TO 1500 J/KG...THOUGH SFC DEWPOINTS MAY BE A
BIT OVERDONE HERE. BASED ON CONSENSUS OF THE MODELS INCLUDING
LOCALLY RUN 4KM WRF...LOOKING FOR DEVELOPMENT OF A FEW STRONG LATE
DAY/EVENING TSTMS AS WELL. SPC CALIBRATED SVR PROBABILITIES AND
DAY 1 OUTLOOK SUPPORT A FEW SEVERE STORMS...AND MENTIONED GUSTY
WINDS AND SMALL HAIL IN THE FORECAST AND HWO FOR LATE
AFTN/EVENING. DEEP LAYER (SFC-6KM) SHEAR EXCEEDS 40 KTS AND IS
SUPPORTIVE OF SOME LONG-LIVED UPDRAFTS. 00Z ALB SOUNDING SHOWED PW
VALUES OF 1.52"...AND NWD ADVECTION OF THIS MOIST AIR MASS WILL
ALSO YIELD LOCALLY HEAVY DOWNPOURS WITH THE CONVECTION LATE THIS
AFTN INTO THIS EVENING. AFTN TEMPS TODAY HIGHLY DEPEND ON SOME
SUNNY BREAKS DURING THE LATE MORNING-MID AFTN PERIOD. ANTICIPATE
SOME INTERVALS OF SUN TODAY...AND WITH 850MB TEMPS OF +14C COULD
WARM QUICKLY DURING THE EARLY AFTN. HIGH TEMPERATURES IN THE
VALLEYS GENERALLY IN THE MID TO UPR 70S...BUT COULD REACH 80F IF
WE GET A BIT MORE SUNSHINE AND INSOLATIONAL HEATING.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH FRIDAY/...
AS OF 418 AM EDT WEDNESDAY...DEEP-LAYER SWLY FLOW AND WARM ADVECTION
CONTINUES OVERNIGHT...WITH BEST ISENTROPIC ASCENT GRADUALLY
SHIFTING NORTH AND EAST. HAVE CARRIED LIKELY POPS FOR WIDESPREAD
SHOWERS AND CONTINUED EMBEDDED TSTMS. SOME DECREASE IN CAPE
OVERNIGHT...SO KEPT ENHANCED WIND/HAIL WORDING JUST THRU THE
EVENING HOURS. LOWS WILL BE ON THE WARM SIDE TONIGHT WITH 60S
DEWPOINTS IN PLACE ALONG WITH CLOUDS AND S-SW WINDS ALL NIGHT. LOW
TEMPS WILL MAINLY BE IN THE UPR 50S TO LOWER 60S.
THURSDAY WILL PRODUCE OUR MOST WIDESPREAD RAINFALL AS COLD FRONT AND
ASSOCIATED POSITIVE TILT 500MB TROUGH BEGINS TO SHIFT SLOWLY SEWD
ACROSS THE FORECAST AREA. MOIST AND MARGINALLY UNSTABLE AIR MASS
WILL SUPPORT SEVERAL BANDS OF SLOW MOVING CONVECTION ALONG/IN
ADVANCE OF THE COLD FRONT. GIVEN THE SETUP...MOST OF THE NWP QPF
LOOKED ON THE LOW SIDE GIVEN EVOLUTION AND MOIST AIR MASS IN
PLACE. TRENDED CLOSER TO HIGHER ECMWF QPF WITH WIDESPREAD 1+"
RAINFALL AMTS ACROSS THE CWA. SOME OF THIS HEAVY RAIN CONTINUES
INTO THURSDAY NIGHT...ESPECIALLY CENTRAL AND ERN VT. CAN/T RULE
OUT LOCALIZED 2" RAINFALL AMTS BEFORE THINGS LIGHTEN UP EARLY
FRIDAY. SOME MINOR FLOODING IS POSSIBLE...REFER TO HYDRO SECTION
BELOW. HIGHS THURSDAY GENERALLY IN THE MID 70S. EPISODES OF
SHOWERS/TSTMS EXPECTED UNDER CLOUDY SKIES.
FRIDAY...LIKELY POPS FOR RAIN SHOWERS IN THE MORNING...THEN
SLOW/GRADUAL DRYING FROM NW-SE ACROSS THE REGION. SHOULD SEE SOME
PARTIAL SUNSHINE LATE IN THE DAY FROM THE CHAMPLAIN VALLEY WWD.
COOLER TEMPS WITH HIGHS IN THE LOW-MID 60S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 450 AM EDT WEDNESDAY...LOTS OF UNCERTAINTY IN FCST AS WE
HEAD INTO THE HOLIDAY WEEKEND...AS LATEST TRENDS SHOW A MUCH
DEEPER/SLOWER SYSTEM FOR FRIDAY INTO SUNDAY. HAVE TRENDED TWD THE
00Z ECMWF AND 12Z GFS SOLUTIONS FOR THIS FCST...WHICH SUPPORTS THE
MENTION OF RAIN ON SATURDAY INTO SATURDAY NIGHT. IF CRNT TRENDS
CONT FOR A MUCH DEEPER AND SLOWER SYSTEM...ADDITIONAL SHOWERS
WOULD BE POSSIBLE FOR SUNDAY. LATEST 00Z ECMWF SHOWS NORTHERN AND
SOUTHERN STREAM INTERACTION BY 12Z SAT...WHICH HELPS TO PRODUCE A
CLOSED AND SLOW MOVING 5H/7H CIRCULATION OVER THE MID ATLANTIC
STATES. WHILE SFC LOW PRES TRACKS FROM NJ COAST TO THE GULF OF
MAINE BY 18Z SUNDAY. GIVEN THE POSITION AND TRACK OF CLOSED SYSTEM
AND ASSOCIATED SFC LOW PRES...EXPECT HEAVIEST QPF TO BE JUST SOUTH
AND EAST OF OUR CWA ON FRIDAY INTO SATURDAY. HOWEVER...BACKSIDE
DEFORMATION BAND OF ENHANCED MID LVL RH AND ASSOCIATED 850 TO
500MB LIFT IS EXPECTED TO DEVELOP. ITS EXTREMELY DIFFICULT TO
DETERMINE EXACT PLACEMENT AND MOVEMENT OF THESE BANDS AND THE
ASSOCIATED PRECIP...THEREFORE WL JUST MENTION CHC POPS FOR
SATURDAY INTO SATURDAY NIGHT. FEEL SYSTEM WL SLIDE JUST FAR ENOUGH
EAST BY SUNDAY TO KEEP FCST DRY ATTM. ON SUNDAY...AS SFC LOW PRES
TRACKS INTO THE GULF OF MAINE...LOOK FOR GUSTY NORTHWEST WINDS TO
DEVELOP. LATEST SOUNDINGS SHOW 85H WINDS BTWN 35 AND 45
KNOTS...WHICH WITH SOME MIXING WL SUPPORT GUSTS BTWN 25 AND 35
MPH..ESPECIALLY SUNDAY AFTN. PROGGED 85H TEMPS SUPPORT HIGHS ONLY
IN THE L/M 50S MTNS TO U50S/L60S FOR SAT AND SUNDAY. EXPECT A
RAW/CLOUDY AND BREEZY TYPE DAY ON SUNDAY...WITH BLW NORMAL TEMPS.
SFC HIGH PRES WL FINALLY BUILD INTO OUR CWA ON MONDAY INTO
TUES...WITH A SLOW CLRING TREND...ALONG WITH WARMER TEMPS. IF
SKIES CLR AND WINDS BECM LIGHT...PATCHY FROST WL BE POSSIBLE IN
THE COLDER MTN VALLEYS LATE THIS WEEKEND OR EARLY NEXT WEEK.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 12Z THURSDAY...IFR CIGS AT MSS/PBG/SLK WL SLOWLY IMPROVE TO
MVFR/VFR BY 15Z THIS MORNING. CIGS WL BE THE SLOWEST TO IMPROVE AT
MSS DUE TO A LIGHT NE DRAINAGE FLW DOWN THE SLV. EXPECT SOME
CLRING BTWN 15Z-18Z TODAY WITH VFR CONDITIONS...BEFORE MORE
SHOWERS/STORMS DEVELOP BY 21Z. A SFC BOUNDARY CONTS TO BE DRAPED
ACRS OUR TAF SITES AND WL BE THE FOCUS FOR PRECIP. THIS
FRNT...COMBINED WITH SFC HEATING/INSTABILITY WL PRODUCE MORE
SCATTERED/NUMEROUS SHOWERS/STORMS LATE THIS AFTN THRU THIS
EVENING. MVFR TO BRIEF PERIODS OF IFR CIGS/VIS LIKELY IN THE
HEAVIER STORMS. IN ADDITION...BRIEF GUSTY WINDS WL BE POSSIBLE.
THIS SHOWERS WL WEAKEN TWD LATE EVENING WITH AREAS OF LOW CLOUDS
AND PATCHY FOG LIKELY DEVELOPING BY 06Z THURSDAY...ESPECIALLY
MSS/SLK/MPV.
OUTLOOK 12Z THURSDAY THROUGH SUNDAY... UNSETTLED WX WITH OCCASIONAL
SHOWERS/STORMS WL CONT FOR THURSDAY INTO FRIDAY ACRS OUR TAF
SITES. THE STRONGER SHOWERS/STORMS ON THURS AFTN/EVENING
ASSOCIATED WITH A SFC COLD FRNT WL PRODUCE MVFR CONDITIONS...WITH
BRIEF PERIODS OF IFR LIKELY. ALSO...ANY STORMS WL HAVE THE
POTENTIAL TO PRODUCE GUSTY SFC WINDS UP TO 40 MPH. AREAS OF FOG
AND LOW CLOUDS WL BE POSSIBLE ON THURSDAY NIGHT...WITH SOME
LOCALIZED IFR/LIFR LIKELY. SCATTERED SHOWERS MAY LINGER INTO
SATURDAY/SUNDAY WITH MVFR...BEFORE HIGH PRES SLOWLY BUILDS INTO THE
REGION BY EARLY NEXT WK. GUSTY NORTHWEST WINDS WL BE POSSIBLE OVER
THE WEEKEND...WITH AREAS OF LLVL TURBULENCE.
&&
.HYDROLOGY...
430AM WEDNESDAY...WIDESPREAD 1.0" TO 1.5" RAINFALL (WITH LOCALLY
HIGHER AMTS) HAS OCCURRED ACROSS THE NORTH COUNTRY DURING THE PAST
24-30 HOURS ASSOCIATED WITH SEVERAL EPISODES OF HEAVY SHOWERS AND
TSTMS. AN ADDITIONAL 1-2" RAINFALL IS FORECAST BETWEEN LATE
AFTN/EVENING SHOWERS AND TSTMS AND THE MORE WIDESPREAD RAIN AND
EMBEDDED TSTMS ON THURSDAY. WHILE ANTECEDENT SOIL CONDITIONS HAVE
BEEN DRY...AND VEGETATION IS FULLY ACTIVE...THE ADDITIONAL
RAINFALL WILL EVENTUALLY BRING THE POTENTIAL FOR STREET/POOR
DRAINAGE FLOODING. ASSOCIATED MINOR FLOODING WOULD MOST LIKELY
OCCUR DURING THE DAY THURSDAY AND INTO THURSDAY NIGHT. MAIN-STEM
RIVER FLOODING IS NOT FORECAST...BUT MAY NEED TO WATCH SOME OF THE
SMALLER RIVERS AND STREAMS THAT COULD LOCALLY EXCEED BANKFUL LATER
THURSDAY AND THURSDAY NIGHT.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...BANACOS
SHORT TERM...BANACOS
LONG TERM...TABER
AVIATION...TABER
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
723 AM EDT WED MAY 22 2013
.SYNOPSIS...
MOSTLY CLOUDY SKIES ARE EXPECTED ACROSS THE NORTH COUNTRY TODAY.
A WARM FRONT LIFTING NORTHEASTWARD ACROSS THE REGION LATE THIS
AFTERNOON AND EVENING WILL BRING THE POTENTIAL FOR ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS. SOME THUNDERSTORMS MAY
PRODUCE SMALL HAIL...GUSTY WINDS...AND LOCALLY HEAVY DOWNPOURS. A
SLOW-MOVING COLD FRONT WILL THEN APPROACH FROM THE EASTERN GREAT
LAKES REGION BRINGING ADDITIONAL WIDESPREAD RAINFALL AND EMBEDDED
THUNDERSTORMS DURING THURSDAY AND THURSDAY NIGHT. WHILE IT WON/T
BE RAINING CONTINUOUSLY...PERIODS OF BRIEFLY HEAVY RAIN ASSOCIATED
WITH THE SHOWERS AND THUNDERSTORMS WILL GENERALLY BRING AN
ADDITIONAL 1 TO 2 INCHES OF RAIN ACROSS THE NORTH COUNTRY THROUGH
THURSDAY NIGHT. SOME MINOR FLOODING WILL BE POSSIBLE...MAINLY
THURSDAY INTO THURSDAY NIGHT WITH THE MOST WIDESPREAD RAINFALL.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AS OF 722 AM EDT WEDNESDAY...UNSETTLED PATTERN CONTINUES ACROSS THE
NORTH COUNTRY IN VCNTY OF E-W ORIENTED FRONTAL ZONE WHICH REMAINS
DRAPED ACROSS THE REGION. SFC TROUGH AND 850MB TEMP GRADIENT
SUGGESTS SYNOPTIC FRONTAL ZONE IS UP NEAR THE INTL BORDER...BUT
GIVEN THE WIDESPREAD CONVECTION THAT HAS OCCURRED IN SEVERAL WAVES
DURING THE PAST 6-12 HOURS...THE EFFECTIVE FRONTAL POSITION
EXTENDS ACROSS THE SRN TIER OF NY INTO NWRN CT WHERE LARGE
MESOSCALE COLD POOL HAS BEEN ESTABLISHED.
WILL SEE PATCHY FOG ACROSS THE REGION THRU 13Z GIVEN SATURATED
LOW-LEVEL CONDITIONS AND GENERALLY LIGHT WINDS. WEAK SFC LOW
ACROSS NRN NY WILL GENERALLY DISSIPATE THRU THE REMAINDER OF THIS
MORNING. THERE ARE SLIGHT 700-500MB HEIGHT RISES THIS MORNING THRU
EARLY AFTN...AND ABSENCE OF LOW-LEVEL CONVERGENCE SUGGESTS
ADDITIONAL RAINFALL IS UNLIKELY THRU ABOUT 19Z. CLOUDS BUT NO PCPN
THRU MID AFTN...WILL TREND SKY COVER FROM OVC TO BKN BY NOONTIME.
THEREAFTER...THERE IS A SWLY BACKING AND STRENGTHENING OF 850MB
FLOW ACROSS WRN PA INTO CENTRAL NY PER MODEL GUIDANCE. FEEL THAT
REMNANT OUTFLOW BOUNDARY ACROSS CENTRAL NY WILL ENHANCE ISENTROPIC
ASCENT LATE IN THE DAY ACROSS THE ADIRONDACKS AND S-CENTRAL
VT...ALLOWING FOR DEVELOPMENT OF SHOWER AND TSTM ACTIVITY. THE 00Z
NAM SHOWS DEVELOPMENT OF MUCAPE OF 500-1000 J/KG ACROSS ALL BUT
NERN PORTION OF THE FORECAST AREA 21-00Z. RAP SOUNDINGS SHOW A BIT
MORE INSTABILITY...UP TO 1500 J/KG...THOUGH SFC DEWPOINTS MAY BE A
BIT OVERDONE HERE. BASED ON CONSENSUS OF THE MODELS INCLUDING
LOCALLY RUN 4KM WRF...LOOKING FOR DEVELOPMENT OF A FEW STRONG LATE
DAY/EVENING TSTMS AS WELL. SPC CALIBRATED SVR PROBABILITIES AND
DAY 1 OUTLOOK SUPPORT A FEW SEVERE STORMS...AND MENTIONED GUSTY
WINDS AND SMALL HAIL IN THE FORECAST AND HWO FOR LATE
AFTN/EVENING. DEEP LAYER (SFC-6KM) SHEAR EXCEEDS 40 KTS AND IS
SUPPORTIVE OF SOME LONG-LIVED UPDRAFTS. 00Z ALB SOUNDING SHOWED PW
VALUES OF 1.52"...AND NWD ADVECTION OF THIS MOIST AIR MASS WILL
ALSO YIELD LOCALLY HEAVY DOWNPOURS WITH THE CONVECTION LATE THIS
AFTN INTO THIS EVENING. AFTN TEMPS TODAY HIGHLY DEPEND ON SOME
SUNNY BREAKS DURING THE LATE MORNING-MID AFTN PERIOD. ANTICIPATE
SOME INTERVALS OF SUN TODAY...AND WITH 850MB TEMPS OF +14C COULD
WARM QUICKLY DURING THE EARLY AFTN. HIGH TEMPERATURES IN THE
VALLEYS GENERALLY IN THE MID TO UPR 70S...BUT COULD REACH 80F IF
WE GET A BIT MORE SUNSHINE AND INSOLATIONAL HEATING.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH FRIDAY/...
AS OF 418 AM EDT WEDNESDAY...DEEP-LAYER SWLY FLOW AND WARM ADVECTION
CONTINUES OVERNIGHT...WITH BEST ISENTROPIC ASCENT GRADUALLY
SHIFTING NORTH AND EAST. HAVE CARRIED LIKELY POPS FOR WIDESPREAD
SHOWERS AND CONTINUED EMBEDDED TSTMS. SOME DECREASE IN CAPE
OVERNIGHT...SO KEPT ENHANCED WIND/HAIL WORDING JUST THRU THE
EVENING HOURS. LOWS WILL BE ON THE WARM SIDE TONIGHT WITH 60S
DEWPOINTS IN PLACE ALONG WITH CLOUDS AND S-SW WINDS ALL NIGHT. LOW
TEMPS WILL MAINLY BE IN THE UPR 50S TO LOWER 60S.
THURSDAY WILL PRODUCE OUR MOST WIDESPREAD RAINFALL AS COLD FRONT AND
ASSOCIATED POSITIVE TILT 500MB TROUGH BEGINS TO SHIFT SLOWLY SEWD
ACROSS THE FORECAST AREA. MOIST AND MARGINALLY UNSTABLE AIR MASS
WILL SUPPORT SEVERAL BANDS OF SLOW MOVING CONVECTION ALONG/IN
ADVANCE OF THE COLD FRONT. GIVEN THE SETUP...MOST OF THE NWP QPF
LOOKED ON THE LOW SIDE GIVEN EVOLUTION AND MOIST AIR MASS IN
PLACE. TRENDED CLOSER TO HIGHER ECMWF QPF WITH WIDESPREAD 1+"
RAINFALL AMTS ACROSS THE CWA. SOME OF THIS HEAVY RAIN CONTINUES
INTO THURSDAY NIGHT...ESPECIALLY CENTRAL AND ERN VT. CAN/T RULE
OUT LOCALIZED 2" RAINFALL AMTS BEFORE THINGS LIGHTEN UP EARLY
FRIDAY. SOME MINOR FLOODING IS POSSIBLE...REFER TO HYDRO SECTION
BELOW. HIGHS THURSDAY GENERALLY IN THE MID 70S. EPISODES OF
SHOWERS/TSTMS EXPECTED UNDER CLOUDY SKIES.
FRIDAY...LIKELY POPS FOR RAIN SHOWERS IN THE MORNING...THEN
SLOW/GRADUAL DRYING FROM NW-SE ACROSS THE REGION. SHOULD SEE SOME
PARTIAL SUNSHINE LATE IN THE DAY FROM THE CHAMPLAIN VALLEY WWD.
COOLER TEMPS WITH HIGHS IN THE LOW-MID 60S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 450 AM EDT WEDNESDAY...LOTS OF UNCERTAINTY IN FCST AS WE
HEAD INTO THE HOLIDAY WEEKEND...AS LATEST TRENDS SHOW A MUCH
DEEPER/SLOWER SYSTEM FOR FRIDAY INTO SUNDAY. HAVE TRENDED TWD THE
00Z ECMWF AND 12Z GFS SOLUTIONS FOR THIS FCST...WHICH SUPPORTS THE
MENTION OF RAIN ON SATURDAY INTO SATURDAY NIGHT. IF CRNT TRENDS
CONT FOR A MUCH DEEPER AND SLOWER SYSTEM...ADDITIONAL SHOWERS
WOULD BE POSSIBLE FOR SUNDAY. LATEST 00Z ECMWF SHOWS NORTHERN AND
SOUTHERN STREAM INTERACTION BY 12Z SAT...WHICH HELPS TO PRODUCE A
CLOSED AND SLOW MOVING 5H/7H CIRCULATION OVER THE MID ATLANTIC
STATES. WHILE SFC LOW PRES TRACKS FROM NJ COAST TO THE GULF OF
MAINE BY 18Z SUNDAY. GIVEN THE POSITION AND TRACK OF CLOSED SYSTEM
AND ASSOCIATED SFC LOW PRES...EXPECT HEAVIEST QPF TO BE JUST SOUTH
AND EAST OF OUR CWA ON FRIDAY INTO SATURDAY. HOWEVER...BACKSIDE
DEFORMATION BAND OF ENHANCED MID LVL RH AND ASSOCIATED 850 TO
500MB LIFT IS EXPECTED TO DEVELOP. ITS EXTREMELY DIFFICULT TO
DETERMINE EXACT PLACEMENT AND MOVEMENT OF THESE BANDS AND THE
ASSOCIATED PRECIP...THEREFORE WL JUST MENTION CHC POPS FOR
SATURDAY INTO SATURDAY NIGHT. FEEL SYSTEM WL SLIDE JUST FAR ENOUGH
EAST BY SUNDAY TO KEEP FCST DRY ATTM. ON SUNDAY...AS SFC LOW PRES
TRACKS INTO THE GULF OF MAINE...LOOK FOR GUSTY NORTHWEST WINDS TO
DEVELOP. LATEST SOUNDINGS SHOW 85H WINDS BTWN 35 AND 45
KNOTS...WHICH WITH SOME MIXING WL SUPPORT GUSTS BTWN 25 AND 35
MPH..ESPECIALLY SUNDAY AFTN. PROGGED 85H TEMPS SUPPORT HIGHS ONLY
IN THE L/M 50S MTNS TO U50S/L60S FOR SAT AND SUNDAY. EXPECT A
RAW/CLOUDY AND BREEZY TYPE DAY ON SUNDAY...WITH BLW NORMAL TEMPS.
SFC HIGH PRES WL FINALLY BUILD INTO OUR CWA ON MONDAY INTO
TUES...WITH A SLOW CLRING TREND...ALONG WITH WARMER TEMPS. IF
SKIES CLR AND WINDS BECM LIGHT...PATCHY FROST WL BE POSSIBLE IN
THE COLDER MTN VALLEYS LATE THIS WEEKEND OR EARLY NEXT WEEK.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 06Z THURSDAY...ONCE AGAIN ANOTHER CHALLENGING AVIATION
FCST WITH REGARDS TO POTENTIAL IFR CIGS/VIS THRU THIS MORNING.
CRNT OBS SHOW TAF SITES RANGING FROM VFR AT RUT TO MVFR AT
BTV/SLK/MSS AND IFR AT MPV/PBG. RADAR SHOWS BAND OF MODERATE RAIN
ACRS THE CPV...WHICH WL BE EAST AND SOUTH OF MPV/RUT TAF SITES BY
07Z. GIVEN 925MB WINDS OF 25 TO 35 KNTS...EXPECT STRATUS
DEVELOPMENT WITH IFR LIKELY AT MPV/MSS/SLK BY 08Z THIS MORNING.
MEANWHILE...SOUNDINGS SHOW PLENTY OF BL RH AT RUT/BTV/PBG...BUT
FEEL MVFR CONDITIONS WITH PERIODS OF IFR CIGS CAN BE EXPECTED TWD
MORNING. ANY IFR CIGS SHOULD SLOWLY DISSIPATE BY 15Z AT
MPV/MSS/SLK...AS SOUTHERLY WINDS DEVELOP. SFC BOUNDARY CONTS TO BE
DRAPED ACRS OUR TAF SITES THIS AFTN. THIS FRNT...COMBINED WITH SFC
HEATING/INSTABILITY WL PRODUCE MORE SCATTERED/NUMEROUS
SHOWERS/STORMS AFT 21Z TODAY...WITH MVFR TO BRIEF PERIODS OF IFR
CIGS/VIS LIKELY IN THE HEAVIER STORMS. IN ADDITION...BRIEF GUSTY
WINDS WL BE POSSIBLE. THIS SHOWERS WL WEAKEN TWD LATE EVENING WITH
AREAS OF LOW CLOUDS AND PATCHY FOG LIKELY DEVELOPING BY 06Z
THURSDAY...ESPECIALLY MSS/SLK/MPV.
OUTLOOK 06Z THURSDAY THROUGH SUNDAY...
UNSETTLED WX WITH OCCASIONAL SHOWERS/STORMS WL CONT FOR THURSDAY
INTO FRIDAY ACRS OUR TAF SITES. THE STRONGER SHOWERS/STORMS ON
THURS AFTN/EVENING ASSOCIATED WITH A SFC COLD FRNT WL PRODUCE MVFR
CONDITIONS...WITH BRIEF PERIODS OF IFR LIKELY. ALSO...ANY STORMS
WL HAVE THE POTENTIAL TO PRODUCE GUSTY SFC WINDS UP TO 40 MPH. AREAS
OF FOG AND LOW CLOUDS WL BE POSSIBLE ON THURSDAY NIGHT...WITH SOME
LOCALIZED IFR/LIFR LIKELY. SCATTERED SHOWERS MAY LINGER INTO EARLY
SATURDAY MORNING...BEFORE HIGH PRES SLOWLY BUILDS INTO THE REGION
BY SUNDAY. GUSTY NORTHWEST WINDS WL BE POSSIBLE OVER THE
WEEKEND...WITH AREAS OF LLVL TURBULENCE.
&&
.HYDROLOGY...
430AM WEDNESDAY...WIDESPREAD 1.0" TO 1.5" RAINFALL (WITH LOCALLY
HIGHER AMTS) HAS OCCURRED ACROSS THE NORTH COUNTRY DURING THE PAST
24-30 HOURS ASSOCIATED WITH SEVERAL EPISODES OF HEAVY SHOWERS AND
TSTMS. AN ADDITIONAL 1-2" RAINFALL IS FORECAST BETWEEN LATE
AFTN/EVENING SHOWERS AND TSTMS AND THE MORE WIDESPREAD RAIN AND
EMBEDDED TSTMS ON THURSDAY. WHILE ANTECEDENT SOIL CONDITIONS HAVE
BEEN DRY...AND VEGETATION IS FULLY ACTIVE...THE ADDITIONAL
RAINFALL WILL EVENTUALLY BRING THE POTENTIAL FOR STREET/POOR
DRAINAGE FLOODING. ASSOCIATED MINOR FLOODING WOULD MOST LIKELY
OCCUR DURING THE DAY THURSDAY AND INTO THURSDAY NIGHT. MAIN-STEM
RIVER FLOODING IS NOT FORECAST...BUT MAY NEED TO WATCH SOME OF THE
SMALLER RIVERS AND STREAMS THAT COULD LOCALLY EXCEED BANKFUL LATER
THURSDAY AND THURSDAY NIGHT.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...BANACOS
SHORT TERM...BANACOS
LONG TERM...TABER
AVIATION...TABER
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
451 AM EDT WED MAY 22 2013
.SYNOPSIS...
MOSTLY CLOUDY SKIES ARE EXPECTED ACROSS THE NORTH COUNTRY TODAY.
A WARM FRONT LIFTING NORTHEASTWARD ACROSS THE REGION LATE THIS
AFTERNOON AND EVENING WILL BRING THE POTENTIAL FOR ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS. SOME THUNDERSTORMS MAY
PRODUCE SMALL HAIL...GUSTY WINDS...AND LOCALLY HEAVY DOWNPOURS. A
SLOW-MOVING COLD FRONT WILL THEN APPROACH FROM THE EASTERN GREAT
LAKES REGION BRINGING ADDITIONAL WIDESPREAD RAINFALL AND EMBEDDED
THUNDERSTORMS DURING THURSDAY AND THURSDAY NIGHT. WHILE IT WON/T
BE RAINING CONTINUOUSLY...PERIODS OF BRIEFLY HEAVY RAIN ASSOCIATED
WITH THE SHOWERS AND THUNDERSTORMS WILL GENERALLY BRING AN
ADDITIONAL 1 TO 2 INCHES OF RAIN ACROSS THE NORTH COUNTRY THROUGH
THURSDAY NIGHT. SOME MINOR FLOODING WILL BE POSSIBLE...MAINLY
THURSDAY INTO THURSDAY NIGHT WITH THE MOST WIDESPREAD RAINFALL.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AS OF 418 AM EDT WEDNESDAY...UNSETTLED PATTERN CONTINUES ACROSS THE
NORTH COUNTRY IN VCNTY OF E-W ORIENTED FRONTAL ZONE WHICH REMAINS
DRAPED ACROSS THE REGION. SFC TROUGH AND 850MB TEMP GRADIENT
SUGGESTS SYNOPTIC FRONTAL ZONE IS UP NEAR THE INTL BORDER...BUT
GIVEN THE WIDESPREAD CONVECTION THAT HAS OCCURRED IN SEVERAL WAVES
DURING THE PAST 6-12 HOURS...THE EFFECTIVE FRONTAL POSITION
EXTENDS ACROSS THE SRN TIER OF NY INTO NWRN CT WHERE LARGE
MESOSCALE COLD POOL HAS BEEN ESTABLISHED.
REMAINING RAIN SHOWERS ACROSS THE NORTH COUNTRY DEPART EWD INTO NH
BY 10Z THIS MORNING. WILL SEE PATCHY FOG AROUND THRU 12Z GIVEN SATURATED
LOW-LEVEL CONDITIONS AND GENERALLY LIGHT WINDS. WEAK SFC LOW ACROSS
NRN NY WILL GENERALLY DISSIPATE THRU THE REMAINDER OF THIS MORNING.
THERE ARE SLIGHT 700-500MB HEIGHT RISES THIS MORNING THRU EARLY
AFTN...AND ABSENCE OF LOW-LEVEL CONVERGENCE SUGGESTS ADDITIONAL
RAINFALL IS UNLIKELY THRU ABOUT 19Z. THEREAFTER...THERE IS A SWLY
BACKING AND STRENGTHENING OF 850MB FLOW ACROSS WRN PA INTO CENTRAL
NY PER MODEL GUIDANCE. FEEL THAT REMNANT OUTFLOW BOUNDARY ACROSS
CENTRAL NY WILL ENHANCE ISENTROPIC ASCENT LATE IN THE DAY ACROSS THE
ADIRONDACKS AND S-CENTRAL VT...ALLOWING FOR DEVELOPMENT OF SHOWER
AND TSTM ACTIVITY. THE 00Z NAM SHOWS DEVELOPMENT OF MUCAPE OF
500-1000 J/KG ACROSS ALL BUT NERN PORTION OF THE FORECAST AREA
21-00Z. RAP SOUNDINGS SHOW A BIT MORE INSTABILITY...UP TO 1500
J/KG...THOUGH SFC DEWPOINTS MAY BE A BIT OVERDONE HERE. BASED ON
CONSENSUS OF THE MODELS INCLUDING LOCALLY RUN 4KM WRF...LOOKING
FOR DEVELOPMENT OF A FEW STRONG LATE DAY/EVENING TSTMS AS WELL.
SPC CALIBRATED SVR PROBABILITIES AND DAY 1 OUTLOOK SUPPORT A FEW
SEVERE STORMS...AND MENTIONED GUSTY WINDS AND SMALL HAIL IN THE
FORECAST AND HWO FOR LATE AFTN/EVENING. DEEP LAYER (SFC-6KM) SHEAR
EXCEEDS 40 KTS AND IS SUPPORTIVE OF SOME LONG-LIVED UPDRAFTS. 00Z
ALB SOUNDING SHOWED PW VALUES OF 1.52"...AND NWD ADVECTION OF THIS
MOIST AIR MASS WILL ALSO YIELD LOCALLY HEAVY DOWNPOURS WITH THE
CONVECTION LATE THIS AFTN INTO THIS EVENING. AFTN TEMPS TODAY
HIGHLY DEPEND ON SOME SUNNY BREAKS DURING THE LATE MORNING-MID
AFTN PERIOD. ANTICIPATE SOME INTERVALS OF SUN TODAY...AND WITH
850MB TEMPS OF +14C COULD WARM QUICKLY DURING THE EARLY AFTN. HIGH
TEMPERATURES IN THE VALLEYS GENERALLY IN THE MID TO UPR 70S...BUT
COULD REACH 80F IF WE GET A BIT MORE SUNSHINE AND INSOLATIONAL
HEATING.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH FRIDAY/...
AS OF 418 AM EDT WEDNESDAY...DEEP-LAYER SWLY FLOW AND WARM ADVECTION
CONTINUES OVERNIGHT...WITH BEST ISENTROPIC ASCENT GRADUALLY
SHIFTING NORTH AND EAST. HAVE CARRIED LIKELY POPS FOR WIDESPREAD
SHOWERS AND CONTINUED EMBEDDED TSTMS. SOME DECREASE IN CAPE
OVERNIGHT...SO KEPT ENHANCED WIND/HAIL WORDING JUST THRU THE
EVENING HOURS. LOWS WILL BE ON THE WARM SIDE TONIGHT WITH 60S
DEWPOINTS IN PLACE ALONG WITH CLOUDS AND S-SW WINDS ALL NIGHT. LOW
TEMPS WILL MAINLY BE IN THE UPR 50S TO LOWER 60S.
THURSDAY WILL PRODUCE OUR MOST WIDESPREAD RAINFALL AS COLD FRONT AND
ASSOCIATED POSITIVE TILT 500MB TROUGH BEGINS TO SHIFT SLOWLY SEWD
ACROSS THE FORECAST AREA. MOIST AND MARGINALLY UNSTABLE AIR MASS
WILL SUPPORT SEVERAL BANDS OF SLOW MOVING CONVECTION ALONG/IN
ADVANCE OF THE COLD FRONT. GIVEN THE SETUP...MOST OF THE NWP QPF
LOOKED ON THE LOW SIDE GIVEN EVOLUTION AND MOIST AIR MASS IN
PLACE. TRENDED CLOSER TO HIGHER ECMWF QPF WITH WIDESPREAD 1+"
RAINFALL AMTS ACROSS THE CWA. SOME OF THIS HEAVY RAIN CONTINUES
INTO THURSDAY NIGHT...ESPECIALLY CENTRAL AND ERN VT. CAN/T RULE
OUT LOCALIZED 2" RAINFALL AMTS BEFORE THINGS LIGHTEN UP EARLY
FRIDAY. SOME MINOR FLOODING IS POSSIBLE...REFER TO HYDRO SECTION
BELOW. HIGHS THURSDAY GENERALLY IN THE MID 70S. EPISODES OF
SHOWERS/TSTMS EXPECTED UNDER CLOUDY SKIES.
FRIDAY...LIKELY POPS FOR RAIN SHOWERS IN THE MORNING...THEN
SLOW/GRADUAL DRYING FROM NW-SE ACROSS THE REGION. SHOULD SEE SOME
PARTIAL SUNSHINE LATE IN THE DAY FROM THE CHAMPLAIN VALLEY WWD.
COOLER TEMPS WITH HIGHS IN THE LOW-MID 60S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 450 AM EDT WEDNESDAY...LOTS OF UNCERTAINTY IN FCST AS WE
HEAD INTO THE HOLIDAY WEEKEND...AS LATEST TRENDS SHOW A MUCH
DEEPER/SLOWER SYSTEM FOR FRIDAY INTO SUNDAY. HAVE TRENDED TWD THE
00Z ECMWF AND 12Z GFS SOLUTIONS FOR THIS FCST...WHICH SUPPORTS THE
MENTION OF RAIN ON SATURDAY INTO SATURDAY NIGHT. IF CRNT TRENDS
CONT FOR A MUCH DEEPER AND SLOWER SYSTEM...ADDITIONAL SHOWERS
WOULD BE POSSIBLE FOR SUNDAY. LATEST 00Z ECMWF SHOWS NORTHERN AND
SOUTHERN STREAM INTERACTION BY 12Z SAT...WHICH HELPS TO PRODUCE A
CLOSED AND SLOW MOVING 5H/7H CIRCULATION OVER THE MID ATLANTIC
STATES. WHILE SFC LOW PRES TRACKS FROM NJ COAST TO THE GULF OF
MAINE BY 18Z SUNDAY. GIVEN THE POSITION AND TRACK OF CLOSED SYSTEM
AND ASSOCIATED SFC LOW PRES...EXPECT HEAVIEST QPF TO BE JUST SOUTH
AND EAST OF OUR CWA ON FRIDAY INTO SATURDAY. HOWEVER...BACKSIDE
DEFORMATION BAND OF ENHANCED MID LVL RH AND ASSOCIATED 850 TO
500MB LIFT IS EXPECTED TO DEVELOP. ITS EXTREMELY DIFFICULT TO
DETERMINE EXACT PLACEMENT AND MOVEMENT OF THESE BANDS AND THE
ASSOCIATED PRECIP...THEREFORE WL JUST MENTION CHC POPS FOR
SATURDAY INTO SATURDAY NIGHT. FEEL SYSTEM WL SLIDE JUST FAR ENOUGH
EAST BY SUNDAY TO KEEP FCST DRY ATTM. ON SUNDAY...AS SFC LOW PRES
TRACKS INTO THE GULF OF MAINE...LOOK FOR GUSTY NORTHWEST WINDS TO
DEVELOP. LATEST SOUNDINGS SHOW 85H WINDS BTWN 35 AND 45
KNOTS...WHICH WITH SOME MIXING WL SUPPORT GUSTS BTWN 25 AND 35
MPH..ESPECIALLY SUNDAY AFTN. PROGGED 85H TEMPS SUPPORT HIGHS ONLY
IN THE L/M 50S MTNS TO U50S/L60S FOR SAT AND SUNDAY. EXPECT A
RAW/CLOUDY AND BREEZY TYPE DAY ON SUNDAY...WITH BLW NORMAL TEMPS.
SFC HIGH PRES WL FINALLY BUILD INTO OUR CWA ON MONDAY INTO
TUES...WITH A SLOW CLRING TREND...ALONG WITH WARMER TEMPS. IF
SKIES CLR AND WINDS BECM LIGHT...PATCHY FROST WL BE POSSIBLE IN
THE COLDER MTN VALLEYS LATE THIS WEEKEND OR EARLY NEXT WEEK.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 06Z THURSDAY...ONCE AGAIN ANOTHER CHALLENGING AVIATION
FCST WITH REGARDS TO POTENTIAL IFR CIGS/VIS THRU THIS MORNING.
CRNT OBS SHOW TAF SITES RANGING FROM VFR AT RUT TO MVFR AT
BTV/SLK/MSS AND IFR AT MPV/PBG. RADAR SHOWS BAND OF MODERATE RAIN
ACRS THE CPV...WHICH WL BE EAST AND SOUTH OF MPV/RUT TAF SITES BY
07Z. GIVEN 925MB WINDS OF 25 TO 35 KNTS...EXPECT STRATUS
DEVELOPMENT WITH IFR LIKELY AT MPV/MSS/SLK BY 08Z THIS MORNING.
MEANWHILE...SOUNDINGS SHOW PLENTY OF BL RH AT RUT/BTV/PBG...BUT
FEEL MVFR CONDITIONS WITH PERIODS OF IFR CIGS CAN BE EXPECTED TWD
MORNING. ANY IFR CIGS SHOULD SLOWLY DISSIPATE BY 15Z AT
MPV/MSS/SLK...AS SOUTHERLY WINDS DEVELOP. SFC BOUNDARY CONTS TO BE
DRAPED ACRS OUR TAF SITES THIS AFTN. THIS FRNT...COMBINED WITH SFC
HEATING/INSTABILITY WL PRODUCE MORE SCATTERED/NUMEROUS
SHOWERS/STORMS AFT 21Z TODAY...WITH MVFR TO BRIEF PERIODS OF IFR
CIGS/VIS LIKELY IN THE HEAVIER STORMS. IN ADDITION...BRIEF GUSTY
WINDS WL BE POSSIBLE. THIS SHOWERS WL WEAKEN TWD LATE EVENING WITH
AREAS OF LOW CLOUDS AND PATCHY FOG LIKELY DEVELOPING BY 06Z
THURSDAY...ESPECIALLY MSS/SLK/MPV.
OUTLOOK 06Z THURSDAY THROUGH SUNDAY...
UNSETTLED WX WITH OCCASIONAL SHOWERS/STORMS WL CONT FOR THURSDAY
INTO FRIDAY ACRS OUR TAF SITES. THE STRONGER SHOWERS/STORMS ON
THURS AFTN/EVENING ASSOCIATED WITH A SFC COLD FRNT WL PRODUCE MVFR
CONDITIONS...WITH BRIEF PERIODS OF IFR LIKELY. ALSO...ANY STORMS
WL HAVE THE POTENTIAL TO PRODUCE GUSTY SFC WINDS UP TO 40 MPH. AREAS
OF FOG AND LOW CLOUDS WL BE POSSIBLE ON THURSDAY NIGHT...WITH SOME
LOCALIZED IFR/LIFR LIKELY. SCATTERED SHOWERS MAY LINGER INTO EARLY
SATURDAY MORNING...BEFORE HIGH PRES SLOWLY BUILDS INTO THE REGION
BY SUNDAY. GUSTY NORTHWEST WINDS WL BE POSSIBLE OVER THE
WEEKEND...WITH AREAS OF LLVL TURBULENCE.
&&
.HYDROLOGY...
430AM WEDNESDAY...WIDESPREAD 1.0" TO 1.5" RAINFALL (WITH LOCALLY
HIGHER AMTS) HAS OCCURRED ACROSS THE NORTH COUNTRY DURING THE PAST
24-30 HOURS ASSOCIATED WITH SEVERAL EPISODES OF HEAVY SHOWERS AND
TSTMS. AN ADDITIONAL 1-2" RAINFALL IS FORECAST BETWEEN LATE
AFTN/EVENING SHOWERS AND TSTMS AND THE MORE WIDESPREAD RAIN AND
EMBEDDED TSTMS ON THURSDAY. WHILE ANTECEDENT SOIL CONDITIONS HAVE
BEEN DRY...AND VEGETATION IS FULLY ACTIVE...THE ADDITIONAL
RAINFALL WILL EVENTUALLY BRING THE POTENTIAL FOR STREET/POOR
DRAINAGE FLOODING. ASSOCIATED MINOR FLOODING WOULD MOST LIKELY
OCCUR DURING THE DAY THURSDAY AND INTO THURSDAY NIGHT. MAIN-STEM
RIVER FLOODING IS NOT FORECAST...BUT MAY NEED TO WATCH SOME OF THE
SMALLER RIVERS AND STREAMS THAT COULD LOCALLY EXCEED BANKFUL LATER
THURSDAY AND THURSDAY NIGHT.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...BANACOS
SHORT TERM...BANACOS
LONG TERM...TABER
AVIATION...TABER
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
425 AM EDT WED MAY 22 2013
.SYNOPSIS...
MOSTLY CLOUDY SKIES ARE EXPECTED ACROSS THE NORTH COUNTRY TODAY.
A WARM FRONT LIFTING NORTHEASTWARD ACROSS THE REGION LATE THIS
AFTERNOON AND EVENING WILL BRING THE POTENTIAL FOR ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS. SOME THUNDERSTORMS MAY
PRODUCE SMALL HAIL...GUSTY WINDS...AND LOCALLY HEAVY DOWNPOURS. A
SLOW-MOVING COLD FRONT WILL THEN APPROACH FROM THE EASTERN GREAT
LAKES REGION BRINGING ADDITIONAL WIDESPREAD RAINFALL AND EMBEDDED
THUNDERSTORMS DURING THURSDAY AND THURSDAY NIGHT. WHILE IT WON/T
BE RAINING CONTINUOUSLY...PERIODS OF BRIEFLY HEAVY RAIN ASSOCIATED
WITH THE SHOWERS AND THUNDERSTORMS WILL GENERALLY BRING AN
ADDITIONAL 1 TO 2 INCHES OF RAIN ACROSS THE NORTH COUNTRY THROUGH
THURSDAY NIGHT. SOME MINOR FLOODING WILL BE POSSIBLE...MAINLY
THURSDAY INTO THURSDAY NIGHT WITH THE MOST WIDESPREAD RAINFALL.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AS OF 418 AM EDT WEDNESDAY...UNSETTLED PATTERN CONTINUES ACROSS THE
NORTH COUNTRY IN VCNTY OF E-W ORIENTED FRONTAL ZONE WHICH REMAINS
DRAPED ACROSS THE REGION. SFC TROUGH AND 850MB TEMP GRADIENT
SUGGESTS SYNOPTIC FRONTAL ZONE IS UP NEAR THE INTL BORDER...BUT
GIVEN THE WIDESPREAD CONVECTION THAT HAS OCCURRED IN SEVERAL WAVES
DURING THE PAST 6-12 HOURS...THE EFFECTIVE FRONTAL POSITION
EXTENDS ACROSS THE SRN TIER OF NY INTO NWRN CT WHERE LARGE
MESOSCALE COLD POOL HAS BEEN ESTABLISHED.
REMAINING RAIN SHOWERS ACROSS THE NORTH COUNTRY DEPART EWD INTO NH
BY 10Z THIS MORNING. WILL SEE PATCHY FOG AROUND THRU 12Z GIVEN SATURATED
LOW-LEVEL CONDITIONS AND GENERALLY LIGHT WINDS. WEAK SFC LOW ACROSS
NRN NY WILL GENERALLY DISSIPATE THRU THE REMAINDER OF THIS MORNING.
THERE ARE SLIGHT 700-500MB HEIGHT RISES THIS MORNING THRU EARLY
AFTN...AND ABSENCE OF LOW-LEVEL CONVERGENCE SUGGESTS ADDITIONAL
RAINFALL IS UNLIKELY THRU ABOUT 19Z. THEREAFTER...THERE IS A SWLY
BACKING AND STRENGTHENING OF 850MB FLOW ACROSS WRN PA INTO CENTRAL
NY PER MODEL GUIDANCE. FEEL THAT REMNANT OUTFLOW BOUNDARY ACROSS
CENTRAL NY WILL ENHANCE ISENTROPIC ASCENT LATE IN THE DAY ACROSS THE
ADIRONDACKS AND S-CENTRAL VT...ALLOWING FOR DEVELOPMENT OF SHOWER
AND TSTM ACTIVITY. THE 00Z NAM SHOWS DEVELOPMENT OF MUCAPE OF
500-1000 J/KG ACROSS ALL BUT NERN PORTION OF THE FORECAST AREA
21-00Z. RAP SOUNDINGS SHOW A BIT MORE INSTABILITY...UP TO 1500
J/KG...THOUGH SFC DEWPOINTS MAY BE A BIT OVERDONE HERE. BASED ON
CONSENSUS OF THE MODELS INCLUDING LOCALLY RUN 4KM WRF...LOOKING
FOR DEVELOPMENT OF A FEW STRONG LATE DAY/EVENING TSTMS AS WELL.
SPC CALIBRATED SVR PROBABILITIES AND DAY 1 OUTLOOK SUPPORT A FEW
SEVERE STORMS...AND MENTIONED GUSTY WINDS AND SMALL HAIL IN THE
FORECAST AND HWO FOR LATE AFTN/EVENING. DEEP LAYER (SFC-6KM) SHEAR
EXCEEDS 40 KTS AND IS SUPPORTIVE OF SOME LONG-LIVED UPDRAFTS. 00Z
ALB SOUNDING SHOWED PW VALUES OF 1.52"...AND NWD ADVECTION OF THIS
MOIST AIR MASS WILL ALSO YIELD LOCALLY HEAVY DOWNPOURS WITH THE
CONVECTION LATE THIS AFTN INTO THIS EVENING. AFTN TEMPS TODAY
HIGHLY DEPEND ON SOME SUNNY BREAKS DURING THE LATE MORNING-MID
AFTN PERIOD. ANTICIPATE SOME INTERVALS OF SUN TODAY...AND WITH
850MB TEMPS OF +14C COULD WARM QUICKLY DURING THE EARLY AFTN. HIGH
TEMPERATURES IN THE VALLEYS GENERALLY IN THE MID TO UPR 70S...BUT
COULD REACH 80F IF WE GET A BIT MORE SUNSHINE AND INSOLATIONAL
HEATING.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH FRIDAY/...
AS OF 418 AM EDT WEDNESDAY...DEEP-LAYER SWLY FLOW AND WARM ADVECTION
CONTINUES OVERNIGHT...WITH BEST ISENTROPIC ASCENT GRADUALLY
SHIFTING NORTH AND EAST. HAVE CARRIED LIKELY POPS FOR WIDESPREAD
SHOWERS AND CONTINUED EMBEDDED TSTMS. SOME DECREASE IN CAPE
OVERNIGHT...SO KEPT ENHANCED WIND/HAIL WORDING JUST THRU THE
EVENING HOURS. LOWS WILL BE ON THE WARM SIDE TONIGHT WITH 60S
DEWPOINTS IN PLACE ALONG WITH CLOUDS AND S-SW WINDS ALL NIGHT. LOW
TEMPS WILL MAINLY BE IN THE UPR 50S TO LOWER 60S.
THURSDAY WILL PRODUCE OUR MOST WIDESPREAD RAINFALL AS COLD FRONT AND
ASSOCIATED POSITIVE TILT 500MB TROUGH BEGINS TO SHIFT SLOWLY SEWD
ACROSS THE FORECAST AREA. MOIST AND MARGINALLY UNSTABLE AIR MASS
WILL SUPPORT SEVERAL BANDS OF SLOW MOVING CONVECTION ALONG/IN
ADVANCE OF THE COLD FRONT. GIVEN THE SETUP...MOST OF THE NWP QPF
LOOKED ON THE LOW SIDE GIVEN EVOLUTION AND MOIST AIR MASS IN
PLACE. TRENDED CLOSER TO HIGHER ECMWF QPF WITH WIDESPREAD 1+"
RAINFALL AMTS ACROSS THE CWA. SOME OF THIS HEAVY RAIN CONTINUES
INTO THURSDAY NIGHT...ESPECIALLY CENTRAL AND ERN VT. CAN/T RULE
OUT LOCALIZED 2" RAINFALL AMTS BEFORE THINGS LIGHTEN UP EARLY
FRIDAY. SOME MINOR FLOODING IS POSSIBLE...REFER TO HYDRO SECTION
BELOW. HIGHS THURSDAY GENERALLY IN THE MID 70S. EPISODES OF
SHOWERS/TSTMS EXPECTED UNDER CLOUDY SKIES.
FRIDAY...LIKELY POPS FOR RAIN SHOWERS IN THE MORNING...THEN
SLOW/GRADUAL DRYING FROM NW-SE ACROSS THE REGION. SHOULD SEE SOME
PARTIAL SUNSHINE LATE IN THE DAY FROM THE CHAMPLAIN VALLEY WWD.
COOLER TEMPS WITH HIGHS IN THE LOW-MID 60S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 225 PM EDT TUESDAY...DEPARTING LOW PRESSURE SYSTEM WILL
HAVE POSITIVELY TILTED UPPER LEVEL TROUGH MOVE OVER THE NORTH
COUNTRY ON FRIDAY...KEEPING CHC OF SHOWERS OVER MUCH OF THE AREA.
LATE FRIDAY IN TO FRIDAY NIGHT...TROUGH LOOKS TO TILT NEUTRAL TO
NEGATIVE AS THE SFC LOW PUSHES OFF THE NEW ENGLAND COAST. SFC LOW
TRAVERSES NEWD NEAR NEWFOUNDLAND...KEEPING BACK/WRN EDGE OF
PRECIP NEAR VT...THEREFORE HAVE KEPT SLGT CHC POPS OVER VT FRIDAY
NIGHT THROUGH FIRST HALF OF SATURDAY. AS HIGH PRESSURE BUILDS
OVER SW HUDSONS BAY...EXTENDING SWD OVER THE CENTRAL GREAT
LAKES...A SHORTWAVE ROTATING ABOUT THE UPPER LEVEL LOW OVER NEW
ENGLAND WILL BE FAIRLY DRY BUT BRING CLOUDS FOR THE REST OF
SATURDAY INTO SATURDAY NIGHT. ON SUNDAY...SOME TROUGHINESS
REMAINING OVER ERN ZONES...WITH CLOUDS OVER MOST OF VT. THE SFC
HIGH PRESSURE AND SOME UPPER LEVEL RIDGING WILL TAKE HOLD OF THE
REGION FOR THE REST OF THE PERIOD.
BELOW NORMAL MAX TEMPS WILL GRADUALLY TREND WARMER THROUGHOUT THE
PERIOD WITH MIN TEMPS GENERALLY IN THE 40S.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 06Z THURSDAY...ONCE AGAIN ANOTHER CHALLENGING AVIATION
FCST WITH REGARDS TO POTENTIAL IFR CIGS/VIS THRU THIS MORNING.
CRNT OBS SHOW TAF SITES RANGING FROM VFR AT RUT TO MVFR AT
BTV/SLK/MSS AND IFR AT MPV/PBG. RADAR SHOWS BAND OF MODERATE RAIN
ACRS THE CPV...WHICH WL BE EAST AND SOUTH OF MPV/RUT TAF SITES BY
07Z. GIVEN 925MB WINDS OF 25 TO 35 KNTS...EXPECT STRATUS
DEVELOPMENT WITH IFR LIKELY AT MPV/MSS/SLK BY 08Z THIS MORNING.
MEANWHILE...SOUNDINGS SHOW PLENTY OF BL RH AT RUT/BTV/PBG...BUT
FEEL MVFR CONDITIONS WITH PERIODS OF IFR CIGS CAN BE EXPECTED TWD
MORNING. ANY IFR CIGS SHOULD SLOWLY DISSIPATE BY 15Z AT
MPV/MSS/SLK...AS SOUTHERLY WINDS DEVELOP. SFC BOUNDARY CONTS TO BE
DRAPED ACRS OUR TAF SITES THIS AFTN. THIS FRNT...COMBINED WITH SFC
HEATING/INSTABILITY WL PRODUCE MORE SCATTERED/NUMEROUS
SHOWERS/STORMS AFT 21Z TODAY...WITH MVFR TO BRIEF PERIODS OF IFR
CIGS/VIS LIKELY IN THE HEAVIER STORMS. IN ADDITION...BRIEF GUSTY
WINDS WL BE POSSIBLE. THIS SHOWERS WL WEAKEN TWD LATE EVENING WITH
AREAS OF LOW CLOUDS AND PATCHY FOG LIKELY DEVELOPING BY 06Z
THURSDAY...ESPECIALLY MSS/SLK/MPV.
OUTLOOK 06Z THURSDAY THROUGH SUNDAY...
UNSETTLED WX WITH OCCASIONAL SHOWERS/STORMS WL CONT FOR THURSDAY
INTO FRIDAY ACRS OUR TAF SITES. THE STRONGER SHOWERS/STORMS ON
THURS AFTN/EVENING ASSOCIATED WITH A SFC COLD FRNT WL PRODUCE MVFR
CONDITIONS...WITH BRIEF PERIODS OF IFR LIKELY. ALSO...ANY STORMS
WL HAVE THE POTENTIAL TO PRODUCE GUSTY SFC WINDS UP TO 40 MPH. AREAS
OF FOG AND LOW CLOUDS WL BE POSSIBLE ON THURSDAY NIGHT...WITH SOME
LOCALIZED IFR/LIFR LIKELY. SCATTERED SHOWERS MAY LINGER INTO EARLY
SATURDAY MORNING...BEFORE HIGH PRES SLOWLY BUILDS INTO THE REGION
BY SUNDAY. GUSTY NORTHWEST WINDS WL BE POSSIBLE OVER THE
WEEKEND...WITH AREAS OF LLVL TURBULENCE.
&&
.HYDROLOGY...
430AM WEDNESDAY...WIDESPREAD 1.0" TO 1.5" RAINFALL (WITH LOCALLY
HIGHER AMTS) HAS OCCURRED ACROSS THE NORTH COUNTRY DURING THE PAST
24-30 HOURS ASSOCIATED WITH SEVERAL EPISODES OF HEAVY SHOWERS AND
TSTMS. AN ADDITIONAL 1-2" RAINFALL IS FORECAST BETWEEN LATE
AFTN/EVENING SHOWERS AND TSTMS AND THE MORE WIDESPREAD RAIN AND
EMBEDDED TSTMS ON THURSDAY. WHILE ANTECEDENT SOIL CONDITIONS HAVE
BEEN DRY...AND VEGETATION IS FULLY ACTIVE...THE ADDITIONAL
RAINFALL WILL EVENTUALLY BRING THE POTENTIAL FOR STREET/POOR
DRAINAGE FLOODING. ASSOCIATED MINOR FLOODING WOULD MOST LIKELY
OCCUR DURING THE DAY THURSDAY AND INTO THURSDAY NIGHT. MAIN-STEM
RIVER FLOODING IS NOT FORECAST...BUT MAY NEED TO WATCH SOME OF THE
SMALLER RIVERS AND STREAMS THAT COULD LOCALLY EXCEED BANKFUL LATER
THURSDAY AND THURSDAY NIGHT.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...BANACOS
SHORT TERM...BANACOS
LONG TERM...KGM
AVIATION...TABER
HYDROLOGY...BANACOS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
805 PM EDT THU MAY 23 2013
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA OVERNIGHT AND EARLY FRIDAY MORNING.
A CANADIAN HIGH PRESSURE SYSTEM WILL BUILD INTO THE REGION WITH
CLEAR AND COOL CONDITIONS FOR MOST OF THE HOLIDAY WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 240 PM THURSDAY...
UPPER LEVEL TROUGH CONTINUES TO DIG SOUTHWARD THIS AFTERNOON AIDED
BY A 50-75 KNOT UPPER JET OVER THE UPPER MISSISSIPPI VALLEY. THE
SURFACE COLD FRONT IS CURRENTLY MOVING ACROSS CENTRAL TENNESSEE AND
WILL TAKE ITS TIME MOVING ACROSS THE MOUNTAINS THIS EVENING. THE
MAIN 500 MB VORT MAX ASSOCIATED WITH THE FRONT WILL NOT ARRIVE UNTIL
CLOSER TO 00Z. FRONTAL PASSAGE WILL FINALLY OCCUR AFTER 00Z IN THE
NORTHWEST PIEDMONT...CLOSER TO 3Z IN THE TRIANGLE AREA...AND NEAR 6Z
FOR THE I-95 CORRIDOR.
CURRENT RADAR TRENDS SHOW A MYRIAD OF SURFACE BOUNDARIES LEFT OVER
FROM LAST NIGHTS CONVECTION AND DIFFERENTIAL HEATING THIS MORNING.
IN ADDITION A SMALL SHORTWAVE TROUGH IS MOVING NORTHWARD FROM
UPSTATE SOUTH CAROLINA. AT THIS TIME THE BOUNDARY INITIATING THE
MOST CONVECTION SPANS SW TO NE FROM THE ROCKINGHAM AREA TO ROANOKE
RAPIDS. AT THIS TIME INGREDIENTS FOR THUNDERSTORMS ARE A BIT
HEALTHIER THAN IN PREVIOUS DAYS. CURRENTLY THERE IS ABOUT 1000 ML
CAPE IN THE EAST WITH LOW LEVEL LAPSE RATES BETWEEN 7-8. EFFECTIVE
SHEAR IS AROUND 20 KNOTS. RAP SOUNDINGS SHOW VERY TALL SKINNY CAPE
IN THE HAIL GROWTH ZONE MAKING SEVERE HAIL UNLIKELY IN THIS SCENARIO
BUT PEA HAIL IS CERTAINLY POSSIBLE. STRAIGHT HODOGRAPHS WITH 20
KNOTS OF SHEAR SUPPORT A MORE LINEAR MULTICELLULAR CONVECTIVE MODE.
THERE IS A RELATIVELY DRIER LAYER NEAR 800 MB WITH A VERY MODEST
INVERTED V MAKING SEVERE WINDS A LITTLE BIT MORE POSSIBLE THAN IN
PREVIOUS DAYS BUT GUSTS WILL MORE LIKELY TOP OUT IN THE 30-40 KNOT
RANGE. CURRENT SPC ANALYSIS ALSO SHOWS AN AREA OF 500-700 J/KG OF
DCAPE ACROSS THE SOUTH CENTRAL PORTION OF THE CWA. DESPITE
PARAMETERS BEING RELATIVELY BETTER TODAY...MID LEVEL LAPSE RATES ARE
STILL VERY WEAK. OVERALL BULK SHEAR IS LOW. THERE IS ENOUGH LIFT IN
THE MID LEVELS TO SUPPORT MORE LIGHTNING THAN IN PREVIOUS DAYS BUT
ANY SEVERE THREAT WILL BE FAIRLY SUBDUED. AS THE VORT MAX APPROACHES
FROM THE NORTHWEST...DYNAMICS WILL IMPROVE SLIGHTLY AND IF THERE IS
STILL CONVECTION AROUND THE NORTHWEST PIEDMONT WOULD BE THE MOST
LIKELY LOCATION TO SEE SEVERE WEATHER.
WITH SEVERE POTENTIAL LOW...HEAVY RAIN AND FLOODING WILL AGAIN BE
THE LARGEST THREAT. WHILE ONLY A QUARTER TO A HALF OF AN INCH OF
WIDESPREAD PRECIPITATION IS EXPECTED...AREAS RECEIVING HEAVY RAINS
OVER THE PAST FEW DAYS WOULD BE A BIT MORE PRIMED FOR URBAN AND
SMALL STREAM FLOODING. CORFIDI VECTORS SHOW THAT STORMS SHOULD BE
PROGRESSIVE ENOUGH TO AVOID TRAINING BUT ORIENTATION OF INDIVIDUAL
BOUNDARIES COULD ALLOW FOR SOME TRAINING CELLS THIS AFTERNOON.
MOISTURE TRANSPORT...PW VALUES AND SURFACE CONVERGENCE ARE ALL BEST
IN THE COASTAL PLAIN THIS AFTERNOON...MAKING THIS THE MOST LIKELY
LOCATION FOR FLOODING TODAY.
SOUTH SOUTHWESTERLY WINDS TODAY WILL SHIFT TO NORTHWESTERLY AFTER
FRONTAL PASSAGE AND SUSTAINED WINDS WILL ELEVATE TO 10-15 KNOTS.
HIGHS TODAY WILL BE LARGELY DEPENDENT UPON CONVECTION AND CLOUD
COVER BUT IN GENERAL...UPPER 70S TO NEAR 80 IN THE NW AND LOWER TO
MID 80S IN THE SOUTH. LOWS WILL BE DEPENDENT UPON THE TIMING OF THE
FRONTAL PASSAGE UPPER 50S TO NEAR 60 IN THE NW AND MID 60S SE. SOME
MVFR CEILINGS OR VISIBILITIES COULD BE POSSIBLE IN THE EAST BEFORE
MAIN FRONT MOVES THROUGH EARLY FRIDAY MORNING.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
AS OF 240 PM THURSDAY...
FRIDAY AND FRIDAY NIGHT...
THE COLD FRONT WILL SLOWLY MOVE OUT OF THE EASTERN AREAS OF THE CWA
DURING THE EARLY MORNING. AFTER FRONTAL PASSAGE WINDS WILL SHIFT TO
NORTHWESTERLY AND INCREASE IN SPEED TO 15 KNOTS SUSTAINED. A VERY
TALL MIXED LAYER DURING THE AFTERNOON AND THE PASSAGE OF A 30 KNOT
850 JET WILL HELP TRANSPORT SOME OF THOSE WINDS DOWN TO THE SURFACE
AND GUSTS OF 25-30 KNOTS ARE POSSIBLE FRIDAY AFTERNOON. SKIES WILL
GRADUALLY CLEAR OUT AND THICKNESSES SUPPORT HIGH TEMPERATURES IN THE
MID 70S IN MOST LOCATIONS. ON FRIDAY NIGHT WINDS WILL REMAIN
BLUSTERY WHICH WILL HELP TO OFFSET RADIATIONAL COOLING A BIT AS
THICKNESSES SUPPORT LOWS NEAR 40 DEGREES BUT WILL GO A BIT
CONSERVATIVE IN THE LOWER 40S. STILL VERY POSSIBLE TO BREAK THE LOW
TEMPERATURE RECORDS AT BOTH RDU AND GSO WHICH ARE BOTH 43 DEGREES.
-ELLIS
SATURDAY THROUGH SUNDAY NIGHT...
A DEEP UPPER LEVEL LOW WILL DRIFT NWD ALONG THE NORTHERN MID
ATLANTIC AND NEW ENGLAND COAST THROUGH SUNDAY. DUE TO THE EXTENSIVE
CIRCULATION ASSOCIATED WITH THIS SYSTEM IN TANDEM WITH AN AMPLIFYING
RIDGE OVER THE CENTRAL U.S....THE FLOW ALOFT ACROSS CENTRAL NC WILL
BE NWLY. AT THE SURFACE...COOL CANADIAN HIGH PRESSURE WILL BUILD
SEWD FROM THE GREAT LAKES INTO THE CAROLINAS. THE DEEP N-NW FLOW
WILL RESULT IN A DRY AND COOL HOLIDAY WEEKEND. THICKNESSES SATURDAY
AFTERNOON IN THE 1360S...SOME 30-35M BELOW NORMAL AND SUPPORTIVE OF
TEMPS UPPER 60S TO NEAR 70. ALLOWING FOR THE WARMTH OF A LATE MAY
SUN...FAVOR TEMPS IN THE LOW-MID 70S.
TEMPS WILL COOL OFF QUICKLY SATURDAY EVENING THEN STABILIZE AS MODEL
RH CROSS SECTIONS SUGGEST INCREASING MID-HIGH LEVEL CLOUDINESS AFTER
MIDNIGHT. THESE CLOUDS ASSOCIATED WITH DISTURBANCES IN THE NW FLOW
ALOFT. THIS TYPE OF PATTERN SUPPORTIVE OF OROGRAPHIC ENHANCED
CLOUDINESS...SO THE USUALLY TOO WET GFS MAY BE ONTO SOMETHING. THE
ARRIVAL OF THESE CLOUDS WILL PLAY A ROLE IN DETERMINING MIN TEMPS.
FAVOR COOLEST TEMPS NE WHERE CLOUDS WILL BE LESS/THINNER COMPARED TO
THE WEST-SW. IF CLOUDS ARE SLOW TO ARRIVE OR THIN...MIN TEMPS MAY
END UP BEING 2-3 DEGREES COOLER THAN FORECAST.
MODEST WARM UP EXPECTED SUNDAY AS THICKNESSES RECOVER INTO THE
1370S/LOW 1380S. EXPECT AFTERNOON TEMPS IN THE MID-UPPER 70S UNDER
PARTLY-MOSTLY SUNNY SKIES. SUNDAY NIGHT SHOULD BE A LITTLE MILDER AS
AIR MASS CONTINUES TO MODIFY. MOS GUIDANCE APPEARS TOO WARM BY A
CATEGORY. FAVOR MIN TEMPS NEAR 50 COOLER SPOTS TO LOW-MID 50S
ELSEWHERE. -WSS
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 PM THURSDAY...
12Z GFS TRENDING TOWARD THE 00Z ECMWF. THE ECMWF HELD ONTO THE L/W
TROUGH ALONG THE EASTERN SEABOARD RESULTING IN A SLOWER WARMING
TREND WHERE AS THE GFS WITH ITS BUILDING MID-UPPER HEIGHTS
ADVERTISES A QUICKER/MORE NOTABLE WARM-UP. THE ECMWF SOLUTION OF A
LINGERING TROUGH NEAR OR OFFSHORE OF THE NEW ENGLAND COAST AND AN
AMPLIFYING RIDGE OVER THE MS RIVER VALLEY WILL MAINTAIN A NW FLOW
ALOFT OVER CENTRAL NC. THE ECMWF HINTS AT POSSIBLE DISTURBANCES
ASSOCIATED WITH MCS ACTIVITY THAT MAY OCCUR IN THE UPPER MID
WEST/GREAT LAKES TUESDAY-THURSDAY CROSSING OUR REGION. IF THIS WERE
TO OCCUR...COULD SEE A PERIOD OF UNSETTLED WEATHER ANYTIME BETWEEN
WEDNESDAY-THURSDAY. IF GFS WERE TO VERIFY WITH THE RIDGE BUILDING
CLOSER TO HOME...MCS ACTIVITY WILL BE SHUNTED MORE TO OUR NORTH. FOR
NOW...WILL KEEP POPS NO HIGHER THAN 20 PERCENT TUESDAY INTO
THURSDAY. LOW LEVEL THICKNESSES RETURN TO NEAR OR SLIGHTLY ABOVE
NORMAL VALUES TUESDAY ONWARD. WILL HAVE AFTERNOON TEMPS NEAR 80-LOWER
80S TUESDAY...AND LOW-MID 80S WEDNESDAY/THURSDAY. AGAIN...IF GFS
VERIFIES...WED/THU COULD SEE TEMPS IN THE UPPER 80S TO NEAR 90.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 805 PM THURSDAY...
NUMEROUS SHOWERS AND STORMS DEVELOPED BETWEEN KRDU AND KRWI/KFAY
AROUND 18Z...AND HAVE SINCE PUSHED EAST INTO THE COASTAL
PLAIN...LEAVING VFR CONDITIONS ACROSS CENTRAL NC WITH A
SOUTH-SOUTHWESTERLY SURFACE WIND. A SECOND LINE OF STORMS HAS
RECENTLY DEVELOPED AND EXTENDS FROM KRNK TO KTNB AS A COLD FRONT AND
UPPER LEVEL TROUGH APPROACHES FROM THE WEST. IT APPEARS THIS LINE
OF STORMS SHOULD SWEEP ACROSS THE TRIAD AREA BETWEEN 00Z AND
02Z...MOVING TO KRDU BY 03-04Z...AND IF IT HOLDS TOGETHER...REACHING
KFAY/KRWI BY 05-06Z. A STRONG WIND SHIFT TO WEST-NORTHWESTERLY
WINDS WILL ACCOMPANY THE LINE..AND CONFIDENCE IS FAIRLY HIGH THAT
GUSTS WILL EXCEED 30KT AT KGSO/KINT. IN ADDITION..CEILINGS AND VSBYS
MAY BRIEFLY FALL TO TO MVFR. FURTHER EAST...MVFR CEILINGS MAY
DEVELOP AHEAD OF THE LINE DUE TO ABUNDANT LOW LEVEL MOISTURE...BUT A
SWITCH NORTHWESTERLY WINDS SHOULD HELP TO SCOUR CEILINGS BY FRIDAY
MORNING.
VFR CONDITIONS WILL CONTINUE ON FRIDAY WITH WINDS STRENGTHENING TO
NEAR 15KT AND GUSTING TO AT LEAST 25KT AS AN UPPER LEVEL TROUGH
SWINGS ACROSS THE AREA.
OUTLOOK...
VFR CONDITIONS ARE EXPECTED THROUGH THE WEEKEND.
&&
.CLIMATE...
MORNING LOW TEMPERATURES ON THE 25TH AND 26TH ARE EXPECTED TO BE
NEAR RECORD MIN TEMPS FOR THE DATE.
RECORD MIN TEMP/YEAR SET MAY 25TH MAY 26TH
RDU 43 / 1967 43 / 1979
GSO 43 / 1956 42 / 1930
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLAES
NEAR TERM...ELLIS
SHORT TERM...ELLIS/WSS
LONG TERM...WSS
AVIATION...SMITH
CLIMATE...RAH
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1015 AM EDT WED MAY 22 2013
.SYNOPSIS...
BERMUDA HIGH PRESSURE WILL DOMINATE THE WEATHER ACROSS THE EASTERN
CAROLINAS THROUGH THURSDAY. SHOWERS AND THUNDERSTORMS WILL INCREASE
THURSDAY AND THURSDAY NIGHT AHEAD OF AN APPROACHING COLD FRONT. THE
FRONT WILL CROSS THE REGION FRIDAY MORNING. A MUCH COOLER AND DRIER
AIRMASS WILL FOLLOW...COMPLEMENTS OF A CANADIAN HIGH PRESSURE...AND
AFFECT THE AREA THIS WEEKEND. THE HIGH WILL SLIDE OFF THE EAST COAST
EARLY NEXT WEEK WITH TEMPERATURES REBOUNDING TO NEAR NORMAL...ALONG
WITH AN INCREASE IN AFTERNOON SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 10:30 AM WEDNESDAY...FIRST SHOWERS OF THE DAY JUST STARTING
TO POP OVER THE COASTAL COUNTIES. NO SIGNIFICANT CHANGES ARE
NEEDED TO THE FORECAST EARLY THIS MORNING. EARLIER DISCUSSION FROM
3:00 AM FOLLOWS:
THE WEAK UPPER LEVEL SHEAR AXIS THAT HAS BEEN NEARLY STATIONARY
ACROSS THE EASTERN CAROLINAS FOR THE PAST TWO DAYS HAS DECAYED AS
LIGHT SOUTHERLY FLOW HAS ESTABLISHED ITSELF THROUGHOUT THE 500-700
MB LAYER. ALTHOUGH THE OVERALL AIRMASS REMAINS THE SAME AS
YESTERDAY...TRIGGERS FOR TODAY`S CONVECTION WILL BE SURFACE
BOUNDARIES ONLY. EARLY MORNING CONVECTION MOVING ONSHORE ACROSS OAK
ISLAND THROUGH WILMINGTON IS ASSOCIATED WITH A LOW-LEVEL CONVERGENCE
AXIS WHERE SOUTHWEST WINDS ACROSS THE SC COASTAL WATERS CONVERGE
WITH SOUTH WINDS CLOSER TO THE GULF STREAM. THIS CONVECTIVE ACTIVITY
SHOULD BECOME MORE ISOLATED IN NATURE TOWARD DAYBREAK...BUT THE
REMNANT CONVERGENCE AXIS MAY BECOME ACTIVE AGAIN BY LATE MORNING AS
THE DEVELOPING SEABREEZE CIRCULATION CREATES ADDITIONAL CONVERGENCE
IN THE LOW LEVELS.
BY EARLY AFTERNOON WE SHOULD HAVE A DEVELOPING FIELD OF SCATTERED
SHOWERS ACROSS MOST OF THE AREA EAST OF I-95 AND WEST OF THE
BEACHES. AS THE SEABREEZE MAKES GOOD PROGRESS INLAND THIS AFTERNOON
EXPECT CLEARING CONDITIONS WITHIN 20 MILES OF THE COAST...BUT
SHOWER AND T-STORM CHANCES WILL INCREASE TO 30-40 PERCENT WEST OF
THE SEABREEZE BOUNDARY IN A MODERATELY UNSTABLE AND COMPLETELY
UNCAPPED AIRMASS. 850 MB TEMPS IN THE +15C TO +17C RANGE WILL
SUPPORT TEMPERATURES IN THE MID 80S INLAND TODAY...WITH LOWER 80S
CLOSER TO THE COAST.
SOUTHWESTERLY WINDS WILL INCREASE ABOVE THE SURFACE TONIGHT AS A
MID-LATITUDE STORM SYSTEM SWEEPS EAST INTO THE GREAT LAKES. A WEAK
VORTICITY MAXIMUM LOCATED ACROSS GEORGIA THIS EVENING WILL MOVE
EASTWARD AND SHOULD SUSTAIN ISOLATED TO SCATTERED SHOWER AND T-STORM
POTENTIAL THROUGH THE NIGHT ACROSS THE EASTERN CAROLINAS. WHILE THE
SC PEE DEE REGION WILL BE THE CLOSEST GEOGRAPHICALLY TO THE INCOMING
VORT ALOFT...PRECIP CHANCES MAY ACTUALLY BECOME GREATEST IN THE
WILMINGTON AREA AS MODELS ARE INSISTENT THAT A BLOB OF GULF STREAM
CONVECTION WILL MOVE NORTH INTO THE CAPE FEAR REGION OVERNIGHT. LOWS
SHOULD FALL TO 66-70...WARMEST AT THE BEACHES.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...THIS PERIOD WILL BE HIGHLIGHTED BY THE
EVOLUTION OF A RATHER DEEP MID-LEVEL TROF THAT WILL DOMINATE THE
WEATHER ACROSS THE FA BY THE END OF THIS PERIOD. AT THE BEGINNING OF
THE SHORT TERM...THE AMPLIFYING UPPER TROF IS PROGGED TO BE JUST
EAST OF THE MISSISSIPPI RIVER...AND BY LATE FRIDAY NIGHT ITS NORTH
TO SOUTH TROF AXIS WILL HAVE MOVED JUST OFF THE NORTH AND SOUTH
CAROLINA COASTS...VIA NAM AND GFS MODELS. MODELS AT TIMES HAVE TRIED
TO MAKE THIS AN AMPLIFIED FULL LATITUDE TROF BUT INDIVIDUAL
VORTS/IMPULSES ROTATING THROUGH THIS UPPER FEATURE...ARE PROGGED TO
MOVE AT DIFFERENT SPEEDS AND THUS PREVENTING THE CARVING OF A TRUE
FULL LATITUDE TROF. ONE OF THE STRONGER VORTS IS PROGGED TO TRACK
ACROSS THE FA FRIDAY AFTERNOON/EVENING AS DYNAMICS FROM THIS FEATURE
AND COLDER TEMPS ALOFT PROVIDE ENOUGH INSTABILITY FOR ISOLATED
CONVECTION.
AT THE SURFACE...WESTERN ATLANTIC RIDGING WILL CONTINUE ACROSS THE
FA EARLY THURSDAY. A PRE-FRONTAL OR LEE SIDE TROF ORIENTED N-S WILL
DEVELOP ACROSS THE WEST-CENTRAL CAROLINAS AND BECOME THE FOCUS FOR
CONVECTION DEVELOPMENT AS IT SLOWLY PROGRESSES EASTWARD. IN ADDITION
MID-DAY/AFTERNOON DIURNALLY INDUCED CONVECTION WILL BREAK OUT ACROSS
THE COASTAL PORTIONS OF THE ILM CWA. WILL INDICATE 50 POPS
INLAND...WITH 30-40 CLOSER TO THE COAST DURING THE DAY THURSDAY. FOR
THURSDAY NIGHT...THE APPROACHING COLD FRONT WILL BECOME THE PRIMARY
FORCE FOR INDUCING CONVECTION. HOWEVER...THE SUB-TROPICAL/TROPICAL
MOISTURE FEED WILL HAVE BEEN PUSHED OFFSHORE AND NO LONGER THE
PRIMARY SOURCE. THINKING IS THAT ENOUGH MOISTURE WILL REMAIN FOR
ADDITIONAL CONVECTION TO FIRE AHEAD OF THE COLD FRONT...DEPENDING
HOW MUCH THE ATM IS ABLE TO DE-STABILIZE FROM THE CONVECTION THAT
DEVELOPED EARLIER IN THE DAY. AS A RESULT...WILL HIGHLIGHT 40-50
POPS IN THE EVENING AND SLOWLY DROP THEM TO SLIGHT CHANCE OVERNIGHT.
MODELS AFTER MIDNIGHT FRIDAY...DIVERGE FROM ONE ANOTHER WITH RESPECT
TO THEIR SOLUTIONS RELATED TO THE TIMING AND PLACEMENT OF THE COLD
FRONT. FOR EXAMPLE THE NAM AND CANADIAN HAVE THE FRONT OFF THE
CAROLINA COASTS BY DAYBREAK FRI...WHEREAS THE GFS LAGS BEHIND AND
ONLY HAS IT PROGRESSING THROUGH THE COASTAL CAROLINAS BY DAYBREAK
FRI. WILL LEAN TOWARD THE SLIGHTLY SLOWER PROGRESSION OF THE CFP.
POST FRONTAL DRIER AIR FINALLY ADVECTS ACROSS THE FA DURING THE DAY
FRI. CANADIAN HIGH PRESSURE WILL FINALLY PROVIDE RELIEF FROM THE
HUMID SUBTROPICAL/TROPICAL AIR MASS THAT AFFECTED THE FA FOR MUCH OF
THIS WEEK.
AS FOR MAX/MIN TEMPS...A RANGE OF 80 TO 85 FOR HIGHS THU...SIMILAR
TO WHAT THE NAM/GFS MOS GUIDANCE SHOWS. THE COLD AIR ADVECTION
BEHIND THE CFP WILL LAG BEHIND...AND BE OFFSET BY A DOWNSLOPE
TRAJECTORY IN THE WIND FIELDS. AS A RESULT...HAVE GONE ABOVE
GUIDANCE FOR FRIDAYS HIGHS WITH THE COASTAL COUNTIES LIKELY TO BE
WARMER THAN INLAND. A COMPROMISED MOS GUIDANCE MIN FORECAST WAS
USED.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 300 AM WEDNESDAY...FOR SATURDAY THRU MONDAY MID LEVEL FEATURES
REMAIN RELATIVELY UNCHANGED WITH THE TROF AXIS ASSOCIATED WITH THE
UPPER TROF HAVING ONLY PROGRESSED JUST OFF THE EAST COAST. THE
CENTRAL U.S. WILL BE HIGHLIGHTED BY AN UPPER RIDGE WITH ITS AXIS
RUNNING N-S ALONG THE MISSISSIPPI RIVER. BY TUESDAY...THE EUROPEAN
FLATTENS THIS RIDGE WHEREAS THE GFS PROGRESSES IT EASTWARD AND
MAINTAINING ITS IDENTITY. PREFERRED THE GFS SOLUTION AT THIS POINT.
AT THE SFC...CANADIAN HIGH PRESSURE TO RIDGE ACROSS THE FA SATURDAY.
ITS CENTER IS PROGGED TO BREAK APART BY SUNDAY...WITH THE SOUTHERN
EXTENT OF ITS CENTER MOVING ACROSS AND OFFSHORE FROM THE CAROLINAS
MONDAY AND TUESDAY. SUBSIDENCE ALOFT WILL KEEP A LID ON THE
DIURNALLY DRIVEN CU FROM DEVELOPING IN THE VERTICAL. THEREFORE NO
POPS THROUGH SUNDAY. FOR LATE SUNDAY NIGHT THRU TUESDAY...MODELS ARE
HINTING AT A BACK-DOOR COLD FRONT DROPPING SOUTHWARD...AND BECOMING
STATIONARY JUST NORTH OF THE FA. THIS MAY BECOME AN AID TO POSSIBLE
MCS/MCC THAT DEVELOP WELL UPSTREAM MON AND TUE...WHICH WILL FOLLOW
THE NW-SE UPPER FLOW. TOO FAR OUT IN TIME TO PREDICT THEIR
TIMING...HOWEVER ENOUGH OF A POSSIBILITY TO PLACE A LOW CHANCE POP
IN THE GOING FORECAST.
FOR THIS UPCOMING MEMORIAL DAY WEEKEND...SATURDAY THROUGH MONDAY
MORNING TEMPS ACROSS THE FA WILL RUN 5 TO 10 DEGREES BELOW
NORMAL...ESPECIALLY WITH OVERNIGHT LOWS. FOR MONDAY THRU
TUESDAY...WILL BE LOOKING AT NEAR NORMAL TEMPS. IF THE BACK-DOOR
COLD FRONT DROPS FURTHER SOUTH THAN ANTICIPATED...THE NW FLOW AHEAD
OF IT COULD PUSH TEMPS WELL INTO THE 80S TO AROUND 90...MUCH HIGHER
THAN THE CURRENT MOS GUIDANCE.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
AS OF 12Z...A BIT LESS DEEP MOISTURE TODAY WITH MAINLY SOUTHERLY
FLOW. A LOW LCL INDICATES A MVFR CEILING COULD FORM AN HOUR OR SO
AFTER SUNRISE. HRRR MODEL INDICATES AN EARLY START TO CONVECTION
ALONG THE SEA BREEZE TODAY...WITH SHOWERS LIKELY NOT AS STRONG DUE
TO LACK OF MOISTURE. MOST OF THE ACTIVITY WILL ACTUALLY BE BETWEEN
THE INLAND AND COASTAL TERMINALS...NEARING THE INLAND TERMINALS BY
18Z. SOUTHERLY FLOW WILL BE A BIT GUSTY THIS AFTERNOON...DIMINISHING
DIURNALLY THIS EVENING. WILL REEVALUATE BACK END OF TAFS ON THE NEXT
MODEL RUN AS ANOTHER SLUG OF MOISTURE ADVECTS IN FROM THE SOUTH.
EXTENDED OUTLOOK...SHOWERS/T-STORMS POSSIBLE THURSDAY THROUGH EARLY
FRIDAY. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 700 AM WEDNESDAY...LATEST OBS SHOW LIGHT SOUTH WINDS WITH
SEAS IN THE 3 TO 4 FT RANGE. NO SIGNIFICANT CHANGES ARE NEEDED TO
THE FORECAST. EARLIER DISCUSSION FROM 3:00 AM FOLLOWS:
BERMUDA HIGH PRESSURE WILL MOVE LITTLE THROUGH TONIGHT...CONTINUING
TO PUMP AIR FROM THE CARIBBEAN NORTHWARD ACROSS THE CAROLINA COASTAL
WATERS. LOW PRESSURE WILL MOVE EAST ACROSS THE GREAT LAKES...TOO FAR
AWAY FOR ANY DIRECT AFFECTS JUST YET. A TYPICAL SUMMER/TROPICAL
WEATHER REGIME IS EXPECTED WITH SCATTERED SHOWERS AND THUNDERSTORMS
OVER THE COASTAL WATERS ENDING THIS MORNING...THEN REDEVELOPING
TONIGHT. MODELS ARE ACTUALLY QUITE INSISTENT THAT AT LEAST ONE
CONCENTRATED BATCH OF CONVECTION COULD ROLL IN OFF THE GULF STREAM
OVERNIGHT AND TOWARD COASTAL NORTH CAROLINA.
OUTSIDE OF ANY SHOWER AND THUNDERSTORM ACTIVITY...SOUTH WINDS SHOULD
AVERAGE 10-15 KNOTS WITH 3-4 FT SEAS. DOMINANT WAVE PERIODS AT THE
FRYING PAN SHOALS BUOY ARE 6 SECONDS...WITH YESTERDAY`S 10 SECOND
EASTERLY SWELL HARDLY REGISTERING ANYMORE.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...WESTERN ATLANTIC RIDGING WILL PROVIDE A
RATHER SOLID 15 KT SOUTHERLY FLOW DURING THU...BECOMING SW LATE
THU AFTERNOON AND NIGHT. THE SFC PG WILL TIGHTEN BETWEEN THE
APPROACHING COLD FRONT AND THE WESTERN ATLANTIC HIGH CENTERED WELL
OFFSHORE FROM THE SE U.S.COAST. COULD SEE 15 TO 20 KT WITH SOME
HIGHER GUSTS. CFP SLATED FOR AFTER DAYBREAK FRI...WITH WINDS
VEERING TO W TO NW 10 TO 15 KT...INCREASING TO 15 TO 25 KT FRIDAY
NIGHT DUE TO COLD AIR ADVECTION COMBINED WITH A TIGHTENED SFC PG.
SIGNIFICANT SEAS WILL RANGE FROM 2 TO 4 FT THU...BUILDING TO 3 TO
5 FT LATE THU THROUGH EARLY FRI. TEMPORARILY DROPPING BACK TO 2 TO
4 FT DURING FRIDAY...THEN BUILDING BACK TO 3 TO 5 FT FRI NIGHT
WITH 6 FOOTERS POSSIBLE OUTER WATERS OFF CAPE FEAR. SIG. SEAS WILL
PRIMARILY BE DRIVEN BY AN ESE GROUND SWELL AT 8 TO 9 SECOND
PERIODS DURING EARLY THU...WITH 4 TO 6 SECOND PERIOD WIND DRIVEN
WAVES TO DOMINATE LATE THU THRU FRI NITE. SCEC CONDITIONS POSSIBLE
FOR ALL WATERS...WITH A BORDERLINE SCA FOR THE ILM NC WATERS
DURING THE INFLUX OF COLD AIR FRI NIGHT.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 AM WEDNESDAY...POSSIBLE SCEC OR SCA CONDITIONS WILL
PEAK DURING EARLY SATURDAY...WITH A DIMINISHING AND SUBSIDING
TREND FOR WINDS AND SIGNIFICANT SEAS RESPECTIVELY DURING THE
LATTER 2/3RDS OF THIS PERIOD. ALL IN RESPONSE TO THE CENTER OF THE
MODERATING CANADIAN HIGH PUSHING ACROSS THE LOCAL WATERS SUNDAY
THROUGH SUNDAY NIGHT. WINDS ARE PROGGED TO BECOME VARIABLE IN
DIRECTION DURING SUNDAY AND SUNDAY NIGHT AT 10 KT OR LESS.
SIGNIFICANT SEAS WILL BE DRIVEN BY LOCALLY PRODUCED SHORT PERIOD
WIND DRIVEN WAVES ON SATURDAY...WITH AN 8 TO 9 SECOND PERIOD SMALL
EASTERLY SWELL DOMINATING ON SUNDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DCH
NEAR TERM...REK/TRA
SHORT TERM...DCH
LONG TERM...DCH
AVIATION...TRA/SGL
MARINE...DCH/REK/TRA
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
703 AM EDT WED MAY 22 2013
.SYNOPSIS...
BERMUDA HIGH PRESSURE WILL DOMINATE THE WEATHER ACROSS THE EASTERN
CAROLINAS THROUGH THURSDAY. SHOWERS AND THUNDERSTORMS WILL INCREASE
THURSDAY AND THURSDAY NIGHT AHEAD OF AN APPROACHING COLD FRONT. THE
FRONT WILL CROSS THE REGION FRIDAY MORNING. A MUCH COOLER AND DRIER
AIRMASS WILL FOLLOW...COMPLEMENTS OF A CANADIAN HIGH PRESSURE...AND
AFFECT THE AREA THIS WEEKEND. THE HIGH WILL SLIDE OFF THE EAST COAST
EARLY NEXT WEEK WITH TEMPERATURES REBOUNDING TO NEAR NORMAL...ALONG
WITH AN INCREASE IN AFTERNOON SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 700 AM WEDNESDAY...EARLIER SHOWER ACTIVITY OFFSHORE AND OVER
WILMINGTON DISSIPATED A COUPLE HOURS AGO. THE ATMOSPHERE REMAINS
SUPPORTIVE OF AT LEAST SHALLOW CONVECTION...BUT CERTAINLY WITH LESS
COVERAGE THAN WHAT WAS EXPERIENCED YESTERDAY GIVEN DRIER AIR ALOFT
AND SUBSEQUENT LOWER PRECIPITABLE WATER VALUES. THIS WILL REDUCE
PRECIPITATION EFFICIENCY AND SHOULD LEAD TO LOWER RAINFALL TOTALS
EVEN WHERE IT DOES RAIN. NO SIGNIFICANT CHANGES ARE NEEDED TO THE
FORECAST EARLY THIS MORNING. PREVIOUS DISCUSSION FROM 300 AM
FOLLOWS...
THE WEAK UPPER LEVEL SHEAR AXIS THAT HAS BEEN NEARLY STATIONARY
ACROSS THE EASTERN CAROLINAS FOR THE PAST TWO DAYS HAS DECAYED AS
LIGHT SOUTHERLY FLOW HAS ESTABLISHED ITSELF THROUGHOUT THE 500-700
MB LAYER. ALTHOUGH THE OVERALL AIRMASS REMAINS THE SAME AS
YESTERDAY...TRIGGERS FOR TODAY`S CONVECTION WILL BE SURFACE
BOUNDARIES ONLY. EARLY MORNING CONVECTION MOVING ONSHORE ACROSS OAK
ISLAND THROUGH WILMINGTON IS ASSOCIATED WITH A LOW-LEVEL CONVERGENCE
AXIS WHERE SOUTHWEST WINDS ACROSS THE SC COASTAL WATERS CONVERGE
WITH SOUTH WINDS CLOSER TO THE GULF STREAM. THIS CONVECTIVE ACTIVITY
SHOULD BECOME MORE ISOLATED IN NATURE TOWARD DAYBREAK...BUT THE
REMNANT CONVERGENCE AXIS MAY BECOME ACTIVE AGAIN BY LATE MORNING AS
THE DEVELOPING SEABREEZE CIRCULATION CREATES ADDITIONAL CONVERGENCE
IN THE LOW LEVELS.
BY EARLY AFTERNOON WE SHOULD HAVE A DEVELOPING FIELD OF SCATTERED
SHOWERS ACROSS MOST OF THE AREA EAST OF I-95 AND WEST OF THE
BEACHES. AS THE SEABREEZE MAKES GOOD PROGRESS INLAND THIS AFTERNOON
EXPECT CLEARING CONDITIONS WITHIN 20 MILES OF THE COAST...BUT
SHOWER AND T-STORM CHANCES WILL INCREASE TO 30-40 PERCENT WEST OF
THE SEABREEZE BOUNDARY IN A MODERATELY UNSTABLE AND COMPLETELY
UNCAPPED AIRMASS. 850 MB TEMPS IN THE +15C TO +17C RANGE WILL
SUPPORT TEMPERATURES IN THE MID 80S INLAND TODAY...WITH LOWER 80S
CLOSER TO THE COAST.
SOUTHWESTERLY WINDS WILL INCREASE ABOVE THE SURFACE TONIGHT AS A
MID-LATITUDE STORM SYSTEM SWEEPS EAST INTO THE GREAT LAKES. A WEAK
VORTICITY MAXIMUM LOCATED ACROSS GEORGIA THIS EVENING WILL MOVE
EASTWARD AND SHOULD SUSTAIN ISOLATED TO SCATTERED SHOWER AND T-STORM
POTENTIAL THROUGH THE NIGHT ACROSS THE EASTERN CAROLINAS. WHILE THE
SC PEE DEE REGION WILL BE THE CLOSEST GEOGRAPHICALLY TO THE INCOMING
VORT ALOFT...PRECIP CHANCES MAY ACTUALLY BECOME GREATEST IN THE
WILMINGTON AREA AS MODELS ARE INSISTENT THAT A BLOB OF GULF STREAM
CONVECTION WILL MOVE NORTH INTO THE CAPE FEAR REGION OVERNIGHT. LOWS
SHOULD FALL TO 66-70...WARMEST AT THE BEACHES.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...THIS PERIOD WILL BE HIGHLIGHTED BY THE
EVOLUTION OF A RATHER DEEP MID-LEVEL TROF THAT WILL DOMINATE THE
WEATHER ACROSS THE FA BY THE END OF THIS PERIOD. AT THE BEGINNING OF
THE SHORT TERM...THE AMPLIFYING UPPER TROF IS PROGGED TO BE JUST
EAST OF THE MISSISSIPPI RIVER...AND BY LATE FRIDAY NIGHT ITS NORTH
TO SOUTH TROF AXIS WILL HAVE MOVED JUST OFF THE NORTH AND SOUTH
CAROLINA COASTS...VIA NAM AND GFS MODELS. MODELS AT TIMES HAVE TRIED
TO MAKE THIS AN AMPLIFIED FULL LATITUDE TROF BUT INDIVIDUAL
VORTS/IMPULSES ROTATING THROUGH THIS UPPER FEATURE...ARE PROGGED TO
MOVE AT DIFFERENT SPEEDS AND THUS PREVENTING THE CARVING OF A TRUE
FULL LATITUDE TROF. ONE OF THE STRONGER VORTS IS PROGGED TO TRACK
ACROSS THE FA FRIDAY AFTERNOON/EVENING AS DYNAMICS FROM THIS FEATURE
AND COLDER TEMPS ALOFT PROVIDE ENOUGH INSTABILITY FOR ISOLATED
CONVECTION.
AT THE SURFACE...WESTERN ATLANTIC RIDGING WILL CONTINUE ACROSS THE
FA EARLY THURSDAY. A PRE-FRONTAL OR LEE SIDE TROF ORIENTED N-S WILL
DEVELOP ACROSS THE WEST-CENTRAL CAROLINAS AND BECOME THE FOCUS FOR
CONVECTION DEVELOPMENT AS IT SLOWLY PROGRESSES EASTWARD. IN ADDITION
MID-DAY/AFTERNOON DIURNALLY INDUCED CONVECTION WILL BREAK OUT ACROSS
THE COASTAL PORTIONS OF THE ILM CWA. WILL INDICATE 50 POPS
INLAND...WITH 30-40 CLOSER TO THE COAST DURING THE DAY THURSDAY. FOR
THURSDAY NIGHT...THE APPROACHING COLD FRONT WILL BECOME THE PRIMARY
FORCE FOR INDUCING CONVECTION. HOWEVER...THE SUB-TROPICAL/TROPICAL
MOISTURE FEED WILL HAVE BEEN PUSHED OFFSHORE AND NO LONGER THE
PRIMARY SOURCE. THINKING IS THAT ENOUGH MOISTURE WILL REMAIN FOR
ADDITIONAL CONVECTION TO FIRE AHEAD OF THE COLD FRONT...DEPENDING
HOW MUCH THE ATM IS ABLE TO DE-STABILIZE FROM THE CONVECTION THAT
DEVELOPED EARLIER IN THE DAY. AS A RESULT...WILL HIGHLIGHT 40-50
POPS IN THE EVENING AND SLOWLY DROP THEM TO SLIGHT CHANCE OVERNIGHT.
MODELS AFTER MIDNIGHT FRIDAY...DIVERGE FROM ONE ANOTHER WITH RESPECT
TO THEIR SOLUTIONS RELATED TO THE TIMING AND PLACEMENT OF THE COLD
FRONT. FOR EXAMPLE THE NAM AND CANADIAN HAVE THE FRONT OFF THE
CAROLINA COASTS BY DAYBREAK FRI...WHEREAS THE GFS LAGS BEHIND AND
ONLY HAS IT PROGRESSING THROUGH THE COASTAL CAROLINAS BY DAYBREAK
FRI. WILL LEAN TOWARD THE SLIGHTLY SLOWER PROGRESSION OF THE CFP.
POST FRONTAL DRIER AIR FINALLY ADVECTS ACROSS THE FA DURING THE DAY
FRI. CANADIAN HIGH PRESSURE WILL FINALLY PROVIDE RELIEF FROM THE
HUMID SUBTROPICAL/TROPICAL AIR MASS THAT AFFECTED THE FA FOR MUCH OF
THIS WEEK.
AS FOR MAX/MIN TEMPS...A RANGE OF 80 TO 85 FOR HIGHS THU...SIMILAR
TO WHAT THE NAM/GFS MOS GUIDANCE SHOWS. THE COLD AIR ADVECTION
BEHIND THE CFP WILL LAG BEHIND...AND BE OFFSET BY A DOWNSLOPE
TRAJECTORY IN THE WIND FIELDS. AS A RESULT...HAVE GONE ABOVE
GUIDANCE FOR FRIDAYS HIGHS WITH THE COASTAL COUNTIES LIKELY TO BE
WARMER THAN INLAND. A COMPROMISED MOS GUIDANCE MIN FORECAST WAS
USED.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 300 AM WEDNESDAY...FOR SATURDAY THRU MONDAY MID LEVEL FEATURES
REMAIN RELATIVELY UNCHANGED WITH THE TROF AXIS ASSOCIATED WITH THE
UPPER TROF HAVING ONLY PROGRESSED JUST OFF THE EAST COAST. THE
CENTRAL U.S. WILL BE HIGHLIGHTED BY AN UPPER RIDGE WITH ITS AXIS
RUNNING N-S ALONG THE MISSISSIPPI RIVER. BY TUESDAY...THE EUROPEAN
FLATTENS THIS RIDGE WHEREAS THE GFS PROGRESSES IT EASTWARD AND
MAINTAINING ITS IDENTITY. PREFERRED THE GFS SOLUTION AT THIS POINT.
AT THE SFC...CANADIAN HIGH PRESSURE TO RIDGE ACROSS THE FA SATURDAY.
ITS CENTER IS PROGGED TO BREAK APART BY SUNDAY...WITH THE SOUTHERN
EXTENT OF ITS CENTER MOVING ACROSS AND OFFSHORE FROM THE CAROLINAS
MONDAY AND TUESDAY. SUBSIDENCE ALOFT WILL KEEP A LID ON THE
DIURNALLY DRIVEN CU FROM DEVELOPING IN THE VERTICAL. THEREFORE NO
POPS THROUGH SUNDAY. FOR LATE SUNDAY NIGHT THRU TUESDAY...MODELS ARE
HINTING AT A BACK-DOOR COLD FRONT DROPPING SOUTHWARD...AND BECOMING
STATIONARY JUST NORTH OF THE FA. THIS MAY BECOME AN AID TO POSSIBLE
MCS/MCC THAT DEVELOP WELL UPSTREAM MON AND TUE...WHICH WILL FOLLOW
THE NW-SE UPPER FLOW. TOO FAR OUT IN TIME TO PREDICT THEIR
TIMING...HOWEVER ENOUGH OF A POSSIBILITY TO PLACE A LOW CHANCE POP
IN THE GOING FORECAST.
FOR THIS UPCOMING MEMORIAL DAY WEEKEND...SATURDAY THROUGH MONDAY
MORNING TEMPS ACROSS THE FA WILL RUN 5 TO 10 DEGREES BELOW
NORMAL...ESPECIALLY WITH OVERNIGHT LOWS. FOR MONDAY THRU
TUESDAY...WILL BE LOOKING AT NEAR NORMAL TEMPS. IF THE BACK-DOOR
COLD FRONT DROPS FURTHER SOUTH THAN ANTICIPATED...THE NW FLOW AHEAD
OF IT COULD PUSH TEMPS WELL INTO THE 80S TO AROUND 90...MUCH HIGHER
THAN THE CURRENT MOS GUIDANCE.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 12Z...A BIT LESS DEEP MOISTURE TODAY WITH MAINLY SOUTHERLY
FLOW. A LOW LCL INDICATES A MVFR CEILING COULD FORM AN HOUR OR SO
AFTER SUNRISE. HRRR MODEL INDICATES AN EARLY START TO CONVECTION
ALONG THE SEA BREEZE TODAY...WITH SHOWERS LIKELY NOT AS STRONG DUE
TO LACK OF MOISTURE. MOST OF THE ACTIVITY WILL ACTUALLY BE BETWEEN
THE INLAND AND COASTAL TERMINALS...NEARING THE INLAND TERMINALS BY
18Z. SOUTHERLY FLOW WILL BE A BIT GUSTY THIS AFTERNOON...DIMINISHING
DIURNALLY THIS EVENING. WILL REEVALUATE BACK END OF TAFS ON THE NEXT
MODEL RUN AS ANOTHER SLUG OF MOISTURE ADVECTS IN FROM THE SOUTH.
EXTENDED OUTLOOK...SHOWERS/T-STORMS POSSIBLE THURSDAY THROUGH EARLY
FRIDAY. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 700 AM WEDNESDAY...ISOLATED SHOWERS MAY CONTINUE THROUGH THE
MORNING HOURS BUT SHOULD DISSIPATE WITH THE AFTERNOON SEABREEZE
CIRCULATION. NO SIGNIFICANT CHANGES ARE NEEDED TO THE FORECAST.
PREVIOUS DISCUSSION FROM 300 AM FOLLOWS...
BERMUDA HIGH PRESSURE WILL MOVE LITTLE THROUGH TONIGHT...CONTINUING
TO PUMP AIR FROM THE CARIBBEAN NORTHWARD ACROSS THE CAROLINA COASTAL
WATERS. LOW PRESSURE WILL MOVE EAST ACROSS THE GREAT LAKES...TOO FAR
AWAY FOR ANY DIRECT AFFECTS JUST YET. A TYPICAL SUMMER/TROPICAL
WEATHER REGIME IS EXPECTED WITH SCATTERED SHOWERS AND THUNDERSTORMS
OVER THE COASTAL WATERS ENDING THIS MORNING...THEN REDEVELOPING
TONIGHT. MODELS ARE ACTUALLY QUITE INSISTENT THAT AT LEAST ONE
CONCENTRATED BATCH OF CONVECTION COULD ROLL IN OFF THE GULF STREAM
OVERNIGHT AND TOWARD COASTAL NORTH CAROLINA.
OUTSIDE OF ANY SHOWER AND THUNDERSTORM ACTIVITY...SOUTH WINDS SHOULD
AVERAGE 10-15 KNOTS WITH 3-4 FT SEAS. DOMINANT WAVE PERIODS AT THE
FRYING PAN SHOALS BUOY ARE 6 SECONDS...WITH YESTERDAY`S 10 SECOND
EASTERLY SWELL HARDLY REGISTERING ANYMORE.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...WESTERN ATLANTIC RIDGING WILL PROVIDE A
RATHER SOLID 15 KT SOUTHERLY FLOW DURING THU...BECOMING SW LATE
THU AFTERNOON AND NIGHT. THE SFC PG WILL TIGHTEN BETWEEN THE
APPROACHING COLD FRONT AND THE WESTERN ATLANTIC HIGH CENTERED WELL
OFFSHORE FROM THE SE U.S.COAST. COULD SEE 15 TO 20 KT WITH SOME
HIGHER GUSTS. CFP SLATED FOR AFTER DAYBREAK FRI...WITH WINDS
VEERING TO W TO NW 10 TO 15 KT...INCREASING TO 15 TO 25 KT FRIDAY
NIGHT DUE TO COLD AIR ADVECTION COMBINED WITH A TIGHTENED SFC PG.
SIGNIFICANT SEAS WILL RANGE FROM 2 TO 4 FT THU...BUILDING TO 3 TO
5 FT LATE THU THROUGH EARLY FRI. TEMPORARILY DROPPING BACK TO 2 TO
4 FT DURING FRIDAY...THEN BUILDING BACK TO 3 TO 5 FT FRI NIGHT
WITH 6 FOOTERS POSSIBLE OUTER WATERS OFF CAPE FEAR. SIG. SEAS WILL
PRIMARILY BE DRIVEN BY AN ESE GROUND SWELL AT 8 TO 9 SECOND
PERIODS DURING EARLY THU...WITH 4 TO 6 SECOND PERIOD WIND DRIVEN
WAVES TO DOMINATE LATE THU THRU FRI NITE. SCEC CONDITIONS POSSIBLE
FOR ALL WATERS...WITH A BORDERLINE SCA FOR THE ILM NC WATERS
DURING THE INFLUX OF COLD AIR FRI NIGHT.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 AM WEDNESDAY...POSSIBLE SCEC OR SCA CONDITIONS WILL
PEAK DURING EARLY SATURDAY...WITH A DIMINISHING AND SUBSIDING
TREND FOR WINDS AND SIGNIFICANT SEAS RESPECTIVELY DURING THE
LATTER 2/3RDS OF THIS PERIOD. ALL IN RESPONSE TO THE CENTER OF THE
MODERATING CANADIAN HIGH PUSHING ACROSS THE LOCAL WATERS SUNDAY
THROUGH SUNDAY NIGHT. WINDS ARE PROGGED TO BECOME VARIABLE IN
DIRECTION DURING SUNDAY AND SUNDAY NIGHT AT 10 KT OR LESS.
SIGNIFICANT SEAS WILL BE DRIVEN BY LOCALLY PRODUCED SHORT PERIOD
WIND DRIVEN WAVES ON SATURDAY...WITH AN 8 TO 9 SECOND PERIOD SMALL
EASTERLY SWELL DOMINATING ON SUNDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DCH/TRA
NEAR TERM...TRA
SHORT TERM...DCH
LONG TERM...DCH
AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
650 AM EDT WED MAY 22 2013
.SYNOPSIS...
WESTERN ATLANTIC HIGH PRESSURE WILL DOMINATE THE WEATHER ACROSS
THE EASTERN CAROLINAS THROUGH EARLY THURSDAY. SHOWERS AND
THUNDERSTORMS WILL INCREASE THURSDAY AND THURSDAY NIGHT AHEAD OF
AN APPROACHING COLD FRONT. THE FRONT WILL CROSS THE REGION FRIDAY
MORNING. A MUCH COOLER AND DRIER AIR MASS WILL FOLLOW...COMPLEMENTS
OF A CANADIAN HIGH PRESSURE...AND AFFECT THE AREA THIS WEEKEND.
THE HIGH WILL SLIDE OFF THE EAST COAST EARLY NEXT WEEK WITH
TEMPERATURES REBOUNDING TO NEAR NORMAL...ALONG WITH AN INCREASE IN
DIURNALLY DRIVEN CONVECTION.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM WEDNESDAY...THE WEAK UPPER LEVEL SHEAR AXIS THAT HAS
BEEN NEARLY STATIONARY ACROSS THE EASTERN CAROLINAS FOR THE PAST TWO
DAYS HAS DECAYED AS LIGHT SOUTHERLY FLOW HAS ESTABLISHED ITSELF
THROUGHOUT THE 500-700 MB LAYER. ALTHOUGH THE OVERALL AIRMASS
REMAINS THE SAME AS YESTERDAY...TRIGGERS FOR TODAY`S CONVECTION WILL
BE SURFACE BOUNDARIES ONLY. EARLY MORNING CONVECTION MOVING ONSHORE
ACROSS OAK ISLAND THROUGH WILMINGTON IS ASSOCIATED WITH A LOW-LEVEL
CONVERGENCE AXIS WHERE SOUTHWEST WINDS ACROSS THE SC COASTAL WATERS
CONVERGE WITH SOUTH WINDS CLOSER TO THE GULF STREAM. THIS CONVECTIVE
ACTIVITY SHOULD BECOME MORE ISOLATED IN NATURE TOWARD DAYBREAK...BUT
THE REMNANT CONVERGENCE AXIS MAY BECOME ACTIVE AGAIN BY LATE
MORNING AS THE DEVELOPING SEABREEZE CIRCULATION CREATES ADDITIONAL
CONVERGENCE IN THE LOW LEVELS.
BY EARLY AFTERNOON WE SHOULD HAVE A DEVELOPING FIELD OF SCATTERED
SHOWERS ACROSS MOST OF THE AREA EAST OF I-95 AND WEST OF THE
BEACHES. AS THE SEABREEZE MAKES GOOD PROGRESS INLAND THIS AFTERNOON
EXPECT CLEARING CONDITIONS WITHIN 20 MILES OF THE COAST...BUT
SHOWER AND T-STORM CHANCES WILL INCREASE TO 30-40 PERCENT WEST OF
THE SEABREEZE BOUNDARY IN A MODERATELY UNSTABLE AND COMPLETELY
UNCAPPED AIRMASS. 850 MB TEMPS IN THE +15C TO +17C RANGE WILL
SUPPORT TEMPERATURES IN THE MID 80S INLAND TODAY...WITH LOWER 80S
CLOSER TO THE COAST.
SOUTHWESTERLY WINDS WILL INCREASE ABOVE THE SURFACE TONIGHT AS A
MID-LATITUDE STORM SYSTEM SWEEPS EAST INTO THE GREAT LAKES. A WEAK
VORTICITY MAXIMUM LOCATED ACROSS GEORGIA THIS EVENING WILL MOVE
EASTWARD AND SHOULD SUSTAIN ISOLATED TO SCATTERED SHOWER AND T-STORM
POTENTIAL THROUGH THE NIGHT ACROSS THE EASTERN CAROLINAS. WHILE THE
SC PEE DEE REGION WILL BE THE CLOSEST GEOGRAPHICALLY TO THE INCOMING
VORT ALOFT...PRECIP CHANCES MAY ACTUALLY BECOME GREATEST IN THE
WILMINGTON AREA AS MODELS ARE INSISTENT THAT A BLOB OF GULF STREAM
CONVECTION WILL MOVE NORTH INTO THE CAPE FEAR REGION OVERNIGHT. LOWS
SHOULD FALL TO 66-70...WARMEST AT THE BEACHES.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...THIS PERIOD WILL BE HIGHLIGHTED BY THE
EVOLUTION OF A RATHER DEEP MID-LEVEL TROF THAT WILL DOMINATE THE
WEATHER ACROSS THE FA BY THE END OF THIS PERIOD. AT THE BEGINNING OF
THE SHORT TERM...THE AMPLIFYING UPPER TROF IS PROGGED TO BE JUST
EAST OF THE MISSISSIPPI RIVER...AND BY LATE FRIDAY NIGHT ITS NORTH
TO SOUTH TROF AXIS WILL HAVE MOVED JUST OFF THE NORTH AND SOUTH
CAROLINA COASTS...VIA NAM AND GFS MODELS. MODELS AT TIMES HAVE TRIED
TO MAKE THIS AN AMPLIFIED FULL LATITUDE TROF BUT INDIVIDUAL
VORTS/IMPULSES ROTATING THROUGH THIS UPPER FEATURE...ARE PROGGED TO
MOVE AT DIFFERENT SPEEDS AND THUS PREVENTING THE CARVING OF A TRUE
FULL LATITUDE TROF. ONE OF THE STRONGER VORTS IS PROGGED TO TRACK
ACROSS THE FA FRIDAY AFTERNOON/EVENING AS DYNAMICS FROM THIS FEATURE
AND COLDER TEMPS ALOFT PROVIDE ENOUGH INSTABILITY FOR ISOLATED
CONVECTION.
AT THE SURFACE...WESTERN ATLANTIC RIDGING WILL CONTINUE ACROSS THE
FA EARLY THURSDAY. A PRE-FRONTAL OR LEE SIDE TROF ORIENTED N-S WILL
DEVELOP ACROSS THE WEST-CENTRAL CAROLINAS AND BECOME THE FOCUS FOR
CONVECTION DEVELOPMENT AS IT SLOWLY PROGRESSES EASTWARD. IN ADDITION
...MID-DAY/AFTERNOON DIURNALLY INDUCED CONVECTION WILL BREAK OUT
ACROSS THE COASTAL PORTIONS OF THE ILM CWA. WILL INDICATE 50 POPS
INLAND...WITH 30-40 CLOSER TO THE COAST DURING THE DAY THURSDAY. FOR
THURSDAY NIGHT...THE APPROACHING COLD FRONT WILL BECOME THE PRIMARY
FORCE FOR INDUCING CONVECTION. HOWEVER...THE SUB-TROPICAL/TROPICAL
MOISTURE FEED WILL HAVE BEEN PUSHED OFFSHORE AND NO LONGER THE
PRIMARY SOURCE. THINKING IS THAT ENOUGH MOISTURE WILL REMAIN FOR
ADDITIONAL CONVECTION TO FIRE AHEAD OF THE COLD FRONT...DEPENDING
HOW MUCH THE ATM IS ABLE TO DE-STABILIZE FROM THE CONVECTION THAT
DEVELOPED EARLIER IN THE DAY. AS A RESULT...WILL HIGHLIGHT 40-50
POPS IN THE EVENING AND SLOWLY DROP THEM TO SLIGHT CHANCE OVERNIGHT.
MODELS AFTER MIDNIGHT FRIDAY...DIVERGE FROM ONE ANOTHER WITH RESPECT
TO THEIR SOLUTIONS RELATED TO THE TIMING AND PLACEMENT OF THE COLD
FRONT. FOR EXAMPLE THE NAM AND CANADIAN HAVE THE FRONT OFF THE
CAROLINA COASTS BY DAYBREAK FRI...WHEREAS THE GFS LAGS BEHIND AND
ONLY HAS IT PROGRESSING THROUGH THE COASTAL CAROLINAS BY DAYBREAK
FRI. WILL LEAN TOWARD THE SLIGHTLY SLOWER PROGRESSION OF THE CFP.
POST FRONTAL DRIER AIR FINALLY ADVECTS ACROSS THE FA DURING THE DAY
FRI. CANADIAN HIGH PRESSURE WILL FINALLY PROVIDE RELIEF FROM THE
HUMID SUBTROPICAL/TROPICAL AIR MASS THAT AFFECTED THE FA FOR MUCH OF
THIS WEEK.
AS FOR MAX/MIN TEMPS...A RANGE OF 80 TO 85 FOR HIGHS THU...SIMILAR
TO WHAT THE NAM/GFS MOS GUIDANCE SHOWS. THE COLD AIR ADVECTION
BEHIND THE CFP WILL LAG BEHIND...AND BE OFFSET BY A DOWNSLOPE
TRAJECTORY IN THE WIND FIELDS. AS A RESULT...HAVE GONE ABOVE
GUIDANCE FOR FRIDAYS HIGHS WITH THE COASTAL COUNTIES LIKELY TO BE
WARMER THAN INLAND. A COMPROMISED MOS GUIDANCE MIN FORECAST WAS
USED.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 300 AM WEDNESDAY...FOR SATURDAY THRU MONDAY MID LEVEL FEATURES
REMAIN RELATIVELY UNCHANGED WITH THE TROF AXIS ASSOCIATED WITH THE
UPPER TROF HAVING ONLY PROGRESSED JUST OFF THE EAST COAST. THE
CENTRAL U.S. WILL BE HIGHLIGHTED BY AN UPPER RIDGE WITH ITS AXIS
RUNNING N-S ALONG THE MISSISSIPPI RIVER. BY TUESDAY...THE EUROPEAN
FLATTENS THIS RIDGE WHEREAS THE GFS PROGRESSES IT EASTWARD AND
MAINTAINING ITS IDENTITY. PREFERRED THE GFS SOLUTION AT THIS POINT.
AT THE SFC...CANADIAN HIGH PRESSURE TO RIDGE ACROSS THE FA SATURDAY.
ITS CENTER IS PROGGED TO BREAK APART BY SUNDAY...WITH THE SOUTHERN
EXTENT OF ITS CENTER MOVING ACROSS AND OFFSHORE FROM THE CAROLINAS
MONDAY AND TUESDAY. SUBSIDENCE ALOFT WILL KEEP A LID ON THE
DIURNALLY DRIVEN CU FROM DEVELOPING IN THE VERTICAL. THEREFORE NO
POPS THROUGH SUNDAY. FOR LATE SUNDAY NIGHT THRU TUESDAY...MODELS ARE
HINTING AT A BACK-DOOR COLD FRONT DROPPING SOUTHWARD...AND BECOMING
STATIONARY JUST NORTH OF THE FA. THIS MAY BECOME AN AID TO POSSIBLE
MCS/MCC THAT DEVELOP WELL UPSTREAM MON AND TUE...WHICH WILL FOLLOW
THE NW-SE UPPER FLOW. TOO FAR OUT IN TIME TO PREDICT THEIR
TIMING...HOWEVER ENOUGH OF A POSSIBILITY TO PLACE A LOW CHANCE POP
IN THE GOING FORECAST.
FOR THIS UPCOMING MEMORIAL DAY WEEKEND...SATURDAY THROUGH MONDAY
MORNING TEMPS ACROSS THE FA WILL RUN 5 TO 10 DEGREES BELOW
NORMAL...ESPECIALLY WITH OVERNIGHT LOWS. FOR MONDAY THRU
TUESDAY...WILL BE LOOKING AT NEAR NORMAL TEMPS. IF THE BACK-DOOR
COLD FRONT DROPS FURTHER SOUTH THAN ANTICIPATED...THE NW FLOW AHEAD
OF IT COULD PUSH TEMPS WELL INTO THE 80S TO AROUND 90...MUCH HIGHER
THAN THE CURRENT MOS GUIDANCE.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 12Z...A BIT LESS DEEP MOISTURE TODAY WITH MAINLY SOUTHERLY
FLOW. A LOW LCL INDICATES A MVFR CEILING COULD FORM AN HOUR OR SO
AFTER SUNRISE. HRRR MODEL INDICATES AN EARLY START TO CONVECTION
ALONG THE SEA BREEZE TODAY...WITH SHOWERS LIKELY NOT AS STRONG DUE
TO LACK OF MOISTURE. MOST OF THE ACTIVITY WILL ACTUALLY BE BETWEEN
THE INLAND AND COASTAL TERMINALS...NEARING THE INLAND TERMINALS BY
18Z. SOUTHERLY FLOW WILL BE A BIT GUSTY THIS AFTERNOON...DIMINISHING
DIURNALLY THIS EVENING. WILL REEVALUATE BACK END OF TAFS ON THE NEXT
MODEL RUN AS ANOTHER SLUG OF MOISTURE ADVECTS IN FROM THE SOUTH.
EXTENDED OUTLOOK...SHOWERS/T-STORMS POSSIBLE THURSDAY THROUGH EARLY
FRIDAY. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM WEDNESDAY...BERMUDA HIGH PRESSURE WILL MOVE LITTLE
THROUGH TONIGHT...CONTINUING TO PUMP AIR FROM THE CARIBBEAN
NORTHWARD ACROSS THE CAROLINA COASTAL WATERS. LOW PRESSURE WILL MOVE
EAST ACROSS THE GREAT LAKES...TOO FAR AWAY FOR ANY DIRECT AFFECTS
JUST YET. A TYPICAL SUMMER/TROPICAL WEATHER REGIME IS EXPECTED WITH
SCATTERED SHOWERS AND THUNDERSTORMS OVER THE COASTAL WATERS ENDING
THIS MORNING...THEN REDEVELOPING TONIGHT. MODELS ARE ACTUALLY QUITE
INSISTENT THAT AT LEAST ONE CONCENTRATED BATCH OF CONVECTION COULD
ROLL IN OFF THE GULF STREAM OVERNIGHT AND TOWARD COASTAL NORTH
CAROLINA.
OUTSIDE OF ANY SHOWER AND THUNDERSTORM ACTIVITY...SOUTH WINDS SHOULD
AVERAGE 10-15 KNOTS WITH 3-4 FT SEAS. DOMINANT WAVE PERIODS AT THE
FRYING PAN SHOALS BUOY ARE 6 SECONDS...WITH YESTERDAY`S 10 SECOND
EASTERLY SWELL HARDLY REGISTERING ANYMORE.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...WESTERN ATLANTIC RIDGING WILL PROVIDE A
RATHER SOLID 15 KT SOUTHERLY FLOW DURING THU...BECOMING SW LATE
THU AFTERNOON AND NIGHT. THE SFC PG WILL TIGHTEN BETWEEN THE
APPROACHING COLD FRONT AND THE WESTERN ATLANTIC HIGH CENTERED WELL
OFFSHORE FROM THE SE U.S.COAST. COULD SEE 15 TO 20 KT WITH SOME
HIGHER GUSTS. CFP SLATED FOR AFTER DAYBREAK FRI...WITH WINDS
VEERING TO W TO NW 10 TO 15 KT...INCREASING TO 15 TO 25 KT FRIDAY
NIGHT DUE TO COLD AIR ADVECTION COMBINED WITH A TIGHTENED SFC PG.
SIGNIFICANT SEAS WILL RANGE FROM 2 TO 4 FT THU...BUILDING TO 3 TO
5 FT LATE THU THROUGH EARLY FRI. TEMPORARILY DROPPING BACK TO 2 TO
4 FT DURING FRIDAY...THEN BUILDING BACK TO 3 TO 5 FT FRI NIGHT
WITH 6 FOOTERS POSSIBLE OUTER WATERS OFF CAPE FEAR. SIG. SEAS WILL
PRIMARILY BE DRIVEN BY AN ESE GROUND SWELL AT 8 TO 9 SECOND
PERIODS DURING EARLY THU...WITH 4 TO 6 SECOND PERIOD WIND DRIVEN
WAVES TO DOMINATE LATE THU THRU FRI NITE. SCEC CONDITIONS POSSIBLE
FOR ALL WATERS...WITH A BORDERLINE SCA FOR THE ILM NC WATERS
DURING THE INFLUX OF COLD AIR FRI NIGHT.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 AM WEDNESDAY...POSSIBLE SCEC OR SCA CONDITIONS WILL
PEAK DURING EARLY SATURDAY...WITH A DIMINISHING AND SUBSIDING
TREND FOR WINDS AND SIGNIFICANT SEAS RESPECTIVELY DURING THE
LATTER 2/3RDS OF THIS PERIOD. ALL IN RESPONSE TO THE CENTER OF THE
MODERATING CANADIAN HIGH PUSHING ACROSS THE LOCAL WATERS SUNDAY
THROUGH SUNDAY NIGHT. WINDS ARE PROGGED TO BECOME VARIABLE IN
DIRECTION DURING SUNDAY AND SUNDAY NIGHT AT 10 KT OR LESS.
SIGNIFICANT SEAS WILL BE DRIVEN BY LOCALLY PRODUCED SHORT PERIOD
WIND DRIVEN WAVES ON SATURDAY...WITH AN 8 TO 9 SECOND PERIOD SMALL
EASTERLY SWELL DOMINATING ON SUNDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DCH
NEAR TERM...TRA
SHORT TERM...DCH
LONG TERM...DCH
AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
136 AM EDT WED MAY 22 2013
.SYNOPSIS...
BERMUDA HIGH PRESSURE WILL DOMINATE THE WEATHER ACROSS THE EASTERN
CAROLINAS. SHOWERS AND THUNDERSTORMS WILL INCREASE ON THURSDAY AHEAD
OF A COLD FRONT THAT WILL CROSS THE REGION EARLY FRIDAY. COOLER AND
DRIER WEATHER WILL FOLLOW FOR THE WEEKEND AND EARLY NEXT WEEK AS
HIGH PRESSURE MOVES OFF THE EAST COAST.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 130 AM THURSDAY...ONLY CHANGES TO THE FORECAST WERE TO
INCREASE CLOUD COVER INLAND GIVEN THE RECENT DEVELOPMENT OF PLENTY
OF LOW STRATUS FROM THE PEE DEE REGION AS FAR EAST AS WHITEVILLE AND
ELIZABETHTOWN. THE LAST FOUR RUNS OF THE HRRR ARE INSISTENT THAT
SCATTERED SHOWERS WILL DEVELOP JUST WEST OF I-95 IN THE NEXT FEW
HOURS. THIS LINES UP NICELY WITH WHAT`S LEFT OF THE 700-500 MB SHEAR
AXIS THAT HAS DEVELOPED CONVECTION EACH OF THE LAST TWO NIGHTS. I
HAVE ONLY INCLUDED A TINY 15-20 PERCENT POP MAINLY FOR THE
DARLINGTON-BENNETTSVILLE CORRIDOR. OTHERWISE NO SIGNIFICANT
CHANGES. PREVIOUS DISCUSSION FROM 1000 PM FOLLOWS...
THE DIURNALLY DRIVEN CONVECTION HAS ENDED ACROSS THE AREA WITH THE
LOSS OF HEATING. SOME OF THE HIGHEST RESOLUTION MODELS ARE
INDICATING A FEW SHOWERS MAY DEVELOP AFTER MIDNIGHT. WE DO EXPECT
CONVECTION TO DEVELOP/EXPAND ACROSS THE WATERS AS A WEAK UPPER LEVEL
DISTURBANCE PASSES UP THE COAST...TO OUR E. IT IS POSSIBLE THAT THE
CONVECTION MAY DEVELOP/EXPAND ONTO THE IMMEDIATE COAST VERY LATE
TONIGHT...BUT THE RISK REMAINS SMALL. CONSIDERABLE EVE CLOUD COVER
WILL CONTINUE TO VERY SLOWLY DIMINISH DURING THE LATE NIGHT.
NIGHTTIME TEMPS WILL AGAIN BE ABOVE NORMAL...MID AND UPPER 60S. THE
LAST TIME MINIMUMS WERE BELOW NORMAL WAS ON MAY 15TH.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...DEEP SOUTH TO SOUTHWEST FLOW FOR MUCH OF THE
PERIOD WILL CONTINUE TO PUMP PLENTY OF GULF MOISTURE INTO THE
REGION. BERMUDA HIGH AND MID LEVEL RIDING OVER THE WESTERN ATLANTIC
BRIEFLY EXPAND WEST WED. INCREASE IN MID LEVEL SUBSIDENCE WILL
LIMIT COVERAGE OF AFTERNOON SHOWERS AND THUNDERSTORMS. DIURNAL
INSTABILITY ALONG WITH PRECIPITABLE WATER VALUES AROUND 1.7 INCHES
AND CONVERGENCE ALONG THE SEA BREEZE HOWEVER SUGGEST POP WILL NOT
BE ZERO. GIVEN THE LIMITING FACTORS SLIGHT CHANCE TO LOW CHANCE
SEEMS REASONABLE WITH INLAND SC FAVORED. WORTH NOTING THAT THE 12Z
NAM IS NOT AS AGGRESSIVE WITH THE BUILDING RIDGE AND IS SLOWER TO
EXIT THE SHORTWAVE REMNANTS. DISCOUNTING THIS SCENARIO FOR NOW AS
IT IS A SIGNIFICANT CHANGE FROM PREVIOUS SOLUTIONS BUT SHOULD IT
VERIFY POP WOULD NEED TO BE MUCH HIGHER.
MID LEVEL RIDGE QUICKLY WEAKENS THU WITH 5H TROUGH APPROACHING FROM
THE WEST. WHILE THE LOCAL ENVIRONMENT REMAINS RELATIVELY
UNCHANGED...DEEP SOUTHERLY FLOW PUSHES PWATS NEAR 1.8 INCHES...THE
LOSS OF SUBSIDENCE WILL RESULT IN A SIGNIFICANT INCREASE IN STORM
COVERAGE. IN ADDITION ANOTHER STRETCHED SHORTWAVE WILL MOVE INTO THE
AREA FROM THE BAHAMAS EARLY THU. PVA AHEAD OF IT REACHES THE AREA
LATE WED NIGHT OR THU MORNING AND SHOULD ENHANCE CONVECTION. AS HAS
BEEN THE CASE OVER THE PAST FEW DAYS THE ENVIRONMENT IS NOT
SUPPORTIVE OF SEVERE WEATHER. HOWEVER DEEP WARM LAYER AND RELATIVELY
SLOW STORM MOTION WITH POTENTIAL FOR TRAINING STORMS WILL KEEP THE
FLOOD THREAT ELEVATED...ESPECIALLY IN AREAS THAT HAVE ALREADY
RECEIVED SIGNIFICANT RAINFALL THE LAST FEW DAYS.
CONVECTION WILL BE WINDING DOWN THU EVENING AS DRY AIR JUST AHEAD OF
THE 5H TROUGH AXIS AND SURFACE COLD FRONT STARTS TO MOVE IN. COLD
FRONT IS SLOW TO CROSS THE AREA...NOT REACHING THE COAST UNTIL CLOSE
TO THE END OF THE PERIOD...BUT ALOFT WESTERLY FLOW STARTS DEVELOPING
BEFORE 00Z FRI. HIGHS WILL BE NEAR TO SLIGHTLY ABOVE CLIMO...WITH
NUMBERS TEMPERED BY CLOUDS IN SOME AREAS WHILE LOWS CONTINUE TO RUN
ABOVE CLIMO.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 3 PM TUESDAY...CHANGE IN AIR MASS EXPECTED ON FRIDAY AS
COLD FRONT MAKES ITS WAY OFF SHORE AND COOL CANADIAN HIGH PRESSURE
BUILDS IN. EXPECT COOLER AND DRIER AIR TO MAKE ITS WAY INTO THE
COASTAL CAROLINAS IN DEEP WEST TO NORTHWEST FLOW. PCP WATER VALUES
UP ABOVE 1.5 INCHES OVER THE DAYS LEADING UP TO FRIDAY WILL DROP
OUT TO LESS THAN AN INCH BY FRI AFTN AND BE DOWN TO LESS THAN A
HALF INCH BY SAT MORNING AS ATMOSPHERIC COLUMN DRIES OUT.
THEREFORE DO NOT EXPECT ANY PCP THROUGH THE WEEKEND IN A
RELATIVELY COOLER AND DRIER NORTHERLY FLOW.
AS FOR TEMPS...FRIDAY SHOULD MAKE IT INTO THE 80S IN MOST PLACES BUT
WILL FEEL COOLER AND DRIER BY THE END OF THE DAY. THE 850 TEMPS DROP
FROM CLOSE TO 15C PREVIOUS DAYS DOWN TO 8 TO 10C THROUGH THE
WEEKEND. SATURDAY AND SUNDAY TEMPS WILL REMAIN BETWEEN 75 TO 80 MOST
PLACES WITH MUCH LOWER DEWPOINTS REACHING DOWN INTO THE 40S INLAND
TO AROUND 50 ALONG THE COAST AS COMPARED TO 65 THE PREVIOUS DAYS.
WILL ALSO SEE MUCH GREATER DIURNAL SWINGS DUE TO THE DRY AIR MASS IN
PLACE. OVERNIGHT LOWS WILL REACH DOWN TO THE LOWER END OF THE 50S
BOTH FRI NIGHT AND SAT NIGHT IN COOL ADVECTION AND BETTER
RADIATIONAL COOLING SAT NIGHT AS HIGH PRESSURE SHIFTS OVERHEAD.
BY LATE SUNDAY INTO MONDAY THE HIGH PRESSURE WILL SHIFT OFF SHORE
GIVING WAY TO A WARMER MOISTER RETURN FLOW THROUGH EARLY NEXT WEEK.
THEREFORE WILL SEE A WARMING TREND. THE GFS SHOWS A WEAK COLD FRONT
DROPPING SOUTH INTO NORTH CAROLINA LATE MONDAY INTO TUES. THEREFORE
WILL SHOW CLOUDS AND CHC OF PCP BACK IN THE FORECAST HOLDING TO THE
NORTH ON MONDAY AND OVER LOCAL AREA BY TUES.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 06Z...THROUGH DAYBREAK...RICH LOW LEVEL MOISTURE WILL HELP
DEVELOP PATCHES OF LOW STRATUS INLAND...PERIODICALLY AFFECTING THE
FLO/LBT AIRPORTS THROUGH 09Z. THE EXPECTATION IS STRATOCUMULUS
CLOUDS DEVELOPING JUST ABOVE THE STRATUS AROUND 2000-3000 FT AGL
WILL HELP ERODE THE LOWER IFR DECK BY 09Z. AT THE COAST VFR
CONDITIONS COULD COME DOWN INTO THE MVFR RANGE AS THE SAME MOISTURE
AROUND 2000-3000 FT AGL PRODUCES A SCT-BKN LAYER OF STRATOCUMULUS IN
THE NEXT FEW HOURS. LIGHT SOUTH WINDS.
AFTER DAYBREAK....ANTICIPATE VFR CONDITIONS WILL PREVAIL WITH
SCATTERED TO OCNL BKN CU/TCU DEVELOPING BY LATE MORNING. SFC WINDS
FROM THE SOUTH WILL INCREASE TO 10-15 KT WITH HIGHER GUSTS AT
CRE/MYR/ILM WITH THE AFTERNOON SEABREEZE. ISOLATED SHRA/TSRA ARE
POSSIBLE INLAND...BUT PROBS ARE TOO LOW TO INCLUDE IN THE TAF AT
THIS TIME.
EVENING HOURS...VFR WITH DIMINISHING WINDS.
EXTENDED OUTLOOK...SLIGHT CHC OF SHOWERS WEDNESDAY. SHOWERS/T-STORMS
POSSIBLE THURSDAY THROUGH EARLY FRIDAY. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 130 AM THURSDAY...NO SIGNIFICANT CHANGES ARE NEEDED TO THE
FORECAST. PREVIOUS DISCUSSION FROM 1000 PM FOLLOWS...
A BERMUDA RIDGE WILL CONTINUE TO DOMINATE THE WATERS AS A WEAK UPPER
LEVEL DISTURBANCE MOVES UP THE COAST...TO OUR E. S TO SW WINDS WILL
BE AROUND 10 KT OR LESS FOR THE REMAINDER OF THE NIGHT. SEAS WILL BE
NEAR 3 FT. A WEAK 7 TO 8 SECOND SE SWELL WILL REMAIN.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...BERMUDA HIGH REMAINS IN CONTROL WED BEFORE
RETREATING EAST THU AHEAD OF A COLD FRONT EXPECTED TO CROSS THE
WATERS LATE THU NIGHT. WED BERMUDA HIGH MAINTAINS SOUTHERLY FLOW
WITH SPEEDS OF 10 TO 15 KT RANGE AND SEAS 2 TO 4 FT. WIND SPEEDS
INCREASE SLIGHTLY THEN VEER THU INTO THU NIGHT AS THE COLD FRONT
APPROACHES FROM THE WEST. WINDS WILL GENERALLY BE 10 TO 15 KT WITH
PERIODS OF SUSTAINED 15 KT LIKELY...ESPECIALLY IN THE AFTERNOON.
WINDS EVENTUALLY VEER TO WEST LATE THU NIGHT AS FRONT PASSES. SEAS
BRIEFLY RISE TO 3 TO 5 FT THU THEN DROP BACK TO 2 TO 4 FT AS PERIOD
ENDS.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 3 PM TUESDAY...COLD FRONT MOVING FARTHER ON FRIDAY AS
COOLER AND DRIER CANADIAN HIGH PRESSURE BUILDS IN BEHIND IT
THROUGH THE WEEKEND. WINDS WILL VEER AROUND FROM WEST AROUND 10
KTS FRIDAY MORNING...TO NORTH TO NORTHEAST AT 15 TO 20 KTS FRIDAY
NIGHT INTO SATURDAY IN COOL SURGE AND TIGHTENED GRADIENT. WINDS
WILL LIGHTEN AND CONTINUE TO VEER AS HIGH PRESSURE SHIFTS OVERHEAD
ON SUNDAY.
SEAS WILL BE ENTIRELY WIND-WAVE DOMINATED BETWEEN 3 AND 5 FT THROUGH
FRI INTO SATURDAY. BY LATE SATURDAY INTO SUNDAY...THE SEAS WILL
SUBSIDE AND WINDS LIGHTEN AS HIGH SHIFTS CLOSER OVERHEAD. EXPECT
SEAS DOWN TO 3 FT OR LESS BY SAT NIGHT INTO SUNDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RJD/TRA
SHORT TERM...III
LONG TERM...RGZ
AVIATION...SGL/TRA
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
125 PM CDT WED MAY 22 2013
.UPDATE...
ISSUED AT 125 PM CDT WED MAY 22 2013
CONFINED REMAINING POPS THIS AFTERNOON ALONG AND SOUTHEAST OF A
LINE FROM FORMAN TO WAHPETON TO WADENA. LOW STRATUS AND LINGERING
LIGHT RAIN SHOWERS WILL CONTINUE TO MOVE SOUTH AND EAST AS THE
RESPONSIBLE SURFACE LOW SLIDES INTO NORTHERN ILLINOIS. ADJUSTED
SKY AND AND TEMPERATURE GRIDS TO MATCH LATEST OBSERVATIONAL
TRENDS. OTHERWISE...NO MAJOR CHANGES TO THIS FORECAST.
UPDATE ISSUED AT 1024 AM CDT WED MAY 22 2013
NO SIGNIFICANT CHANGES REQUIRED WITH THIS UPDATE AS THE INHERITED
FORECAST IS ON TRACK AND BLENDED TO 15 UTC OBSERVED TRENDS. GIVEN
RADAR AND SURFACE OBSERVATIONS...DID INCREASE POPS TO NEAR 100
FOR THIS MORNING ACROSS LAKES COUNTRY...DECREASING THROUGH THE
AFTERNOON WITH THE CWA EXPECTED TO BE PRECIPITATION FREE BY 22-00
UTC. THE RAP HAS PERFORMED WELL IN REGARDS TO THE STRATUS SHIELD
THE PAST COUPLE OF DAYS AND FOLLOWED ITS LATEST 14 UTC SOLUTION
FOR CLOUD COVER.
UPDATE ISSUED AT 647 AM CDT WED MAY 22 2013
NORTH TO NORTHEASTERLY WINDS PICKING UP HAVE SCOURED OUT THE FOG
THAT WAS STARTING TO FORM OVER OUR NORTHWESTERN COUNTIES...SO
REMOVED MENTION FOR THE REST OF THE MORNING. RAIN WILL LINGER OVER
THE SOUTHEASTERN COUNTIES FOR A WHILE LONGER THIS MORNING BEFORE
DRYING OUT THIS AFTERNOON. CLOUDS WILL DECREASE THROUGHOUT THE
DAY.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 330 AM CDT WED MAY 22 2013
UPPER LOW FINALLY BEGINNING TO PULL AWAY FROM THE CWA AS IT WILL
SLOWLY MOVE SOUTHEASTWARD INTO IA TODAY. SFC HIGH PRESSURE HAS
STARTED TO NOSE DOWN OUT OF CANADA INTO THE NORTHERN PLAINS. MOST
OF THE PRECIP HAS MOVED SOUTH OF THE AREA ALTHOUGH A FEW SCATTERED
SHOWERS STILL LINGER IN THE SOUTHERN COUNTIES. THE NORTH HAS
CLEARED OUT COMPLETELY AND THERE HAS BEEN SOME PATCHY FOG
FORMATION AROUND CANDO AND LANGDON. HOWEVER...THERE IS STILL A
PRESSURE GRADIENT AND THINK THIS WILL KEEP FOG FROM BECOMING
WIDESPREAD AND DENSE. WILL KEEP A CLOSE EYE ON OBS THROUGH THE
EARLY MORNING HOURS.
SHOWERS AND CLOUDS WILL LINGER OVER THE SOUTHERN COUNTIES FOR MUCH
OF THE DAY BEFORE FINALLY CLEARING OUT BY LATE AFTERNOON. THIS
WILL KEEP TEMPS COOLER AND AROUND 60 WHILE THE NORTH WILL BE A BIT
WARMER. THE SFC HIGH WILL MOVE FURTHER DOWN FROM CANADA INTO THE
UPPER MS VALLEY TONIGHT. THIS SHOULD HELP THE NORTHER TIER ALONG WITH
EASTERN COUNTIES GET DOWN TO BELOW 40 DEGREES IN SOME AREAS.
THURSDAY SHOULD BE QUIET AND A BIT WARMER AS UPPER RIDGING BUILDS
OVER THE REGION. WITH SOME DECENT SUNSHINE KEPT HIGHS IN THE 60S
TO LOW 70S.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 330 AM CDT WED MAY 22 2013
THURSDAY NIGHT SOUTHEASTERLY WINDS STILL START PICKING UP OVER THE
WESTERN COUNTIES AS SFC HIGH PRESSURE OVER MN/WI ALONG WITH A
DEVELOPING LOW OVER MT CREATES A DECENT PRESSURE GRADIENT. THE
WINDS WILL HELP KEEP THE WESTERN COUNTIES FROM COMPLETELY
DECOUPLING AND STAY A BIT WARMER WHILE THE EAST WILL AGAIN DROP TO
AROUND 40 DEGREES. SOUTHEASTERLY WINDS WILL CONTINUE INTO FRIDAY
AND FRIDAY NIGHT AS A LEE TROUGH CONTINUES OVER THE WESTERN
PLAINS. MODELS ARE ALL IN FAIRLY DECENT AGREEMENT ON A WEAK
SHORTWAVE COMING OVER THE UPPER RIDGE AND SOME DECENT ISENTROPIC
LIFT PRODUCING SOME PRECIP FRIDAY AFTERNOON INTO FRIDAY NIGHT. AT
THIS POINT THE INSTABILITY SEEMS FAIRLY WEAK WITH SFC BASED CAPE
STAYING WEST OF OUR AREA AND ONLY A LITTLE BIT OF ELEVATED CAPE TO
WORK WITH. INCLUDED A CHANCE OF SHOWERS WITH ISOLATED
THUNDERSTORMS THROUGH FRIDAY NIGHT WITH BEST CHANCES IN OUR WEST.
SATURDAY-TUESDAY...00Z MODELS CONTINUE TO SUGGEST THE SYNOPTIC
PATTERN WILL BE DOMINATED BY LONGWAVE TROUGHING OVER THE WESTERN
US...WITH SOME DEGREE OF MID/UPPER LEVEL RIDGING INTO THE PLAINS
DURING MUCH OF THIS PERIOD. A SERIES OF WEAK UPPER LEVEL SHORTWAVE
TROUGHS EJECTING OUT OF THE BROADER TROUGH TO THE WEST WILL LEAD TO
BOUTS OF SHOWERS OR THUNDERSTORMS ACROSS THE REGION WITHIN THE LOW
TO MID-LEVEL WARM AIR ADVECTION ZONE ASSOCIATED WITH THE INDIVIDUAL
WAVES. WITH THIS TYPE OF PATTERN...CONFIDENCE IN THE
TIMING/PLACEMENT OF INDIVIDUAL WAVES IS LOW...SO CONTINUED TO CARRY
SOME POPS FOR MUCH OF THE PERIOD...ALTHOUGH MANY DRY HOURS ARE
EXPECTED.
THE 00Z GFS/ECMWF SUGGEST A TREND TO A MORE PREDOMINANT ACTIVE
SOUTHWEST FLOW PATTERN ACROSS THE PLAINS TOWARDS THE MIDDLE OF NEXT
WEEK...ALTHOUGH THE GFS IS MORE AMPLIFIED. THE GFS/ECMWF 925 MB
TEMPS RISE TO NEAR 20C ON TUESDAY...SUPPORTING HIGH TEMPS RISING
FROM MAINLY THE 60S OVER THE WEEKEND INTO THE 70S BY MONDAY OR
TUESDAY...WITH LOWS PRIMARILY IN THE 50S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 125 PM CDT WED MAY 22 2013
MVFR STRATUS DECK AND LIGHT RAIN SHOWERS HAVE MOVED JUST SOUTH OF
KBJI AND KFAR WITH CLEARING TO THE NORTH OF THIS LINE. EXPECT VFR
CONDITIONS TO PERSIST AT ALL TAF SITES THROUGH 18 UTC THURSDAY WITH
NORTHEAST WINDS GUSTING AT TIMES TO 25 KTS THIS AFTERNOON WEAKENING
AFTER SUNSET.
&&
.HYDROLOGY...
ISSUED AT 125 PM CDT WED MAY 22 2013
RIVER FLOOD WARNINGS REMAIN IN EFFECT AT WALHALLA AND NECHE ALONG
THE PEMBINA RIVER...WITH WALHALLA HAVING CRESTED EARLIER.
BIGGEST FORECAST CHANGE IS ALONG PARK RIVER AT GRAFTON WHERE THE
RECENT RAINFALL HAS TRIGGERED RAPID STAGE RISES TOWARD MAJOR AND
ULTIMATELY NEAR RECORD FLOOD LEVELS.
RIVER FLOOD WARNINGS ARE NOW IN EFFECT FOR MOST OF THE NORTHERN
MAINSTEM RED AS WELL AS THE SOUTHERN VALLEY MINNESOTA TRIBUTARIES
TO THE RED. THESE POINTS ARE ALL EXPECTED TO ACHIEVE MINOR FLOOD
STAGE EXCEPT FOR OSLO WHERE MODERATE FLOODING IS FORECAST.
AREAL FLOOD WARNINGS WILL BE IN EFFECT FOR PEMBINA...EASTERN
CAVALIER...AND WALSH COUNTIES THROUGH THURSDAY. BY THEN AREAL
FLOODING SHOULD BECOME LESS OF A CONCERN WITH LITTLE PRECIPITATION
AND THE CHANCE FOR SOME DRYING WITH WARMER TEMPERATURES.
A FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH FRIDAY AFTERNOON FOR
AREAS DOWNSTREAM OF THE RENWICK DAM ON THE TONGUE RIVER. WATER
REMAINS VERY HIGH AT THE DAM SITE AND IS BEING HELD BACK BY A
CONSTRUCTED EARTHEN LEVEE ON TOP OF THE DAM STRUCTURE. ALSO...
OFFICIALS ARE CONTINUING TO MONITOR SEVERAL RETENTION DAMS TO THE
WEST OF RENWICK DAM.
AT THIS TIME...OFFICIALS NOTE THE TEMPORARY LEVEE ON TOP OF THE
RENWICK DAM APPEARS TO BE STABLE AND WILL BE CONTINUALLY MONITORED.
HOWEVER...THE THREAT REMAINS AND FAILURE WOULD MEAN MAJOR FLOODING
WOULD BE IMMINENT FOR THE CITIES OF AKRA...CAVALIER...AND BATHGATE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...FLASH FLOOD WATCH THROUGH FRIDAY AFTERNOON FOR NDZ008.
MN...NONE.
&&
$$
UPDATE...ROGERS
SHORT TERM...JR
LONG TERM...JR/MAKOWSKI
AVIATION...ROGERS
HYDROLOGY...BH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1233 PM CDT WED MAY 22 2013
.UPDATE...
ISSUED AT 1230 PM CDT WED MAY 22 2013
MAIN CHANGE TO THE FORECAST WAS TO INCREASE MAX TEMPERATURES THIS
AFTERNOON A COUPLE OF DEGREES IN MOST LOCATIONS. TEMPERATURES HAVE
BEEN RISING A LITTLE MORE QUICKLY THAN INITIALLY ANTICIPATED...AND
THE LATEST GFS LAMP GUIDANCE SUPPORTS THE SLIGHTLY WARMER VALUES.
THE REST OF THE FORECAST IS IN GOOD SHAPE AND ONLY CHANGES WERE TO
CAPTURE CURRENT TRENDS.
UPDATE ISSUED AT 1006 AM CDT WED MAY 22 2013
MADE ONLY MINOR ADJUSTMENTS TO THE CURRENT FORECAST. THE 22.12Z
NAM AND LATEST RAP STILL SUGGEST A SMALL CHANCE FOR A SHOWER IN
THE FAR SOUTHEAST CORNER OF THE FORECAST AREA TODAY. DID NOT
INCREASE RAIN CHANCES IN THAT AREA FOR THE UPDATE...BUT WILL HAVE
TO KEEP AN EYE ON RADAR TRENDS IN CASE A STRAY SHOWER TRIES TO
MOVE IN LATER.
CLOUDS CONTINUE TO CLEAR FROM NORTH TO SOUTH...WITH THE MOST
ABUNDANT CLOUD COVER IN THE SOUTHERN JAMES RIVER VALLEY AS OF MID
MORNING. ADJUSTED NEAR TERM SKY COVER GRIDS TO REFLECT THE
TRENDS...WITH THE FORECAST FOR THIS AFTERNOON STILL ON TRACK.
UPDATE ISSUED AT 641 AM CDT WED MAY 22 2013
SURFACE HIGH PRESSURE CONTINUES TO BUILD INTO THE REGION THIS
MORNING. ENOUGH GRADIENT FLOW HAS DEVELOPED TO MIX OUT MORNING FOG
ACROSS THE NORTHERN PORTIONS OF THE STATE. AS OF THE 11Z
OBS...THERE WAS NO FOG REPORTED ACROSS THE NORTHERN CWA. AS A
RESULT...REMOVED MORNING FOG WORDING FROM THE GRIDS AND ZONES.
FURTHERMORE...REGIONAL RADARS ARE NOT DETECTING ANY SHOWER
ACTIVITY ACROSS THE SOUTHERN CWA. LOWERED MORNING POPS AS A
RESULT. OTHERWISE...ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS
BASED ON CURRENT OBS/TRENDS. THE UPDATED GRIDDED AND TEXT PRODUCTS
HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 343 AM CDT WED MAY 22 2013
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE DRY AND COOL
WEATHER IN THE WAKE OF THE STORM SYSTEM WHICH BROUGHT WIDESPREAD
HEAVY RAINFALL TO MUCH OF WEST AND CENTRAL NORTH DAKOTA THE PAST
SEVERAL DAYS.
CURRENTLY...MOSTLY CLEAR CONDITIONS ACROSS NORTHERN NORTH DAKOTA
WITH HIGH PRESSURE SLOWLY BUILDING SOUTH INTO THE NORTHERN PLAINS.
SCATTERED LIGHT RAIN CONTINUES TO ADVECT WEST-SOUTHWEST FURTHER
SOUTH...STILL UNDER THE INFLUENCE OF THE CLOSED UPPER LOW WHICH IS
MOVING SLOWLY SOUTH AND EAST INTO THE MID/UPPER MISSISSIPPI VALLEY
REGION. PRECIPITATION CHANCES WILL CONTINUE TO DIMINISH FROM NORTH
TO SOUTH AS THE LOW MOVES OUT OF THE REGION...AND SKIES WILL
CONTINUE TO CLEAR FROM NORTH TO SOUTH NOW THROUGH 15Z. WILL MAINTAIN
MORNING FOG NORTH WITH T/TD SPREADS NEARING ZERO AS SKIES
CLEAR...AND SEVERAL OBSERVING SITES REPORTING FOG. WILL MONITOR FOR
POSSIBLE DENSE FOG...HOWEVER WINDS ARE EXPECTED TO INCREASE SHORTLY
AFTER SUNRISE SO DO NOT EXPECT THE DURATION OF THE FOG TO BE VERY
LONG.
THE RIDGE CONTINUES TO BUILD SLOWLY SOUTH ACROSS THE CENTRAL
DAKOTAS TODAY...WITH GENERALLY SUNNY SKIES AND HIGHS IN THE 60S. THE
LATEST 00Z GFS/ECMWF DO GENERATE 100-200 J/KG OF MUCAPE THIS
AFTERNOON/EARLY EVENING ALONG A COLD FRONT PUSHING SOUTH ACROSS
SOUTHERN MANITOBA INTO NORTHEASTERN NORTH DAKOTA. FOR NOW WILL LEAVE
THINGS DRY...BUT COULD SEE A SHOWER OR TWO AROUND THE TURTLE
MOUNTAINS/DEVILS LAKE BASIN AREA.
ANOTHER COOL NIGHT WEDNESDAY THANKS TO CLEAR SKIES...LIGHT
WINDS...AND SFC DEWPOINTS RANGING FROM 35-45. THIS SHOULD RESULT IN
LOW TEMPERATURES AROUND 40 TO 45. SOUTHEAST RETURN FLOW INCREASES
LATE TONIGHT FAR WEST.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 343 AM CDT WED MAY 22 2013
DRY CONDITIONS ARE EXPECTED THURSDAY AS MID/UPPER LEVEL RIDGING
DEVELOPS OVER THE PLAINS. GRADIENT FLOW WILL INCREASE WEST IN
RESPONSE TO AN UPPER LEVEL LOW OVER THE PACIFIC NORTHWEST. WIND
ADVISORY CONDITIONS WILL BE POSSIBLE OVER SOUTHWESTERN NORTH DAKOTA
THURSDAY AFTERNOON/EVENING.
THE MEDIUM RANGE MODELS PROG THE FIRST IMPULSE TO EJECT FROM OF THE
AFOREMENTIONED PACIFIC NORTHWEST LOW OVER WESTERN AND CENTRAL NORTH
DAKOTA FRIDAY. THIS WILL LEAD TO THUNDERSTORM CHANCES DEVELOPING
AREAWIDE BY FRIDAY AFTERNOON.
AN UNSETTLED WEATHER PATTERN WILL CONTINUE THROUGH THE END OF THE
PERIOD. PERSISTENT SOUTHWESTERLY FLOW ALOFT COMBINED WITH GULF OF
MEXICO MOISTURE TAP WILL LEAD TO CHANCES FOR THUNDERSTORMS EACH DAY
THIS WEEKEND THROUGH THE FIRST PART OF NEXT WEEK. THE PERSISTENT
RETURN FLOW SHOULD ALSO ALLOW FOR A GRADUAL WARMING TREND TO DEVELOP
SATURDAY AND CONTINUE THROUGH THE END OF THE PERIOD. BY
TUESDAY...HIGHS SHOULD GENERALLY BE IN THE MID 70S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1230 PM CDT WED MAY 22 2013
EAST / NORTHEAST WINDS INCREASED LATE THIS MORNING...AND EXPECT
GUSTS TO NEAR 25 KTS AT ALL TERMINAL LOCATIONS THROUGH THE
AFTERNOON. WINDS WILL DIMINISH THIS EVENING...BUT WILL INCREASE
AGAIN THURSDAY MORNING. VFR CONDITIONS WILL PREVAIL THROUGH THE
PERIOD...WITH ONLY PASSING SCATTERED CLOUDS AROUND 4KFT EXPECTED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CK
SHORT TERM...NH
LONG TERM...TM
AVIATION...CK
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1025 AM CDT WED MAY 22 2013
.UPDATE...
ISSUED AT 1024 AM CDT WED MAY 22 2013
NO SIGNIFICANT CHANGES REQUIRED WITH THIS UPDATE AS THE INHERITED
FORECAST IS ON TRACK AND BLENDED TO 15 UTC OBSERVED TRENDS. GIVEN
RADAR AND SURFACE OBSERVATIONS...DID INCREASE POPS TO NEAR 100
FOR THIS MORNING ACROSS LAKES COUNTRY...DECREASING THROUGH THE
AFTERNOON WITH THE CWA EXPECTED TO BE PRECIPITATION FREE BY 22-00
UTC. THE RAP HAS PERFORMED WELL IN REGARDS TO THE STRATUS SHIELD
THE PAST COUPLE OF DAYS AND FOLLOWED ITS LATEST 14 UTC SOLUTION
FOR CLOUD COVER.
UPDATE ISSUED AT 647 AM CDT WED MAY 22 2013
NORTH TO NORTHEASTERLY WINDS PICKING UP HAVE SCOURED OUT THE FOG
THAT WAS STARTING TO FORM OVER OUR NORTHWESTERN COUNTIES...SO
REMOVED MENTION FOR THE REST OF THE MORNING. RAIN WILL LINGER OVER
THE SOUTHEASTERN COUNTIES FOR A WHILE LONGER THIS MORNING BEFORE
DRYING OUT THIS AFTERNOON. CLOUDS WILL DECREASE THROUGHOUT THE
DAY.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 330 AM CDT WED MAY 22 2013
UPPER LOW FINALLY BEGINNING TO PULL AWAY FROM THE CWA AS IT WILL
SLOWLY MOVE SOUTHEASTWARD INTO IA TODAY. SFC HIGH PRESSURE HAS
STARTED TO NOSE DOWN OUT OF CANADA INTO THE NORTHERN PLAINS. MOST
OF THE PRECIP HAS MOVED SOUTH OF THE AREA ALTHOUGH A FEW SCATTERED
SHOWERS STILL LINGER IN THE SOUTHERN COUNTIES. THE NORTH HAS
CLEARED OUT COMPLETELY AND THERE HAS BEEN SOME PATCHY FOG
FORMATION AROUND CANDO AND LANGDON. HOWEVER...THERE IS STILL A
PRESSURE GRADIENT AND THINK THIS WILL KEEP FOG FROM BECOMING
WIDESPREAD AND DENSE. WILL KEEP A CLOSE EYE ON OBS THROUGH THE
EARLY MORNING HOURS.
SHOWERS AND CLOUDS WILL LINGER OVER THE SOUTHERN COUNTIES FOR MUCH
OF THE DAY BEFORE FINALLY CLEARING OUT BY LATE AFTERNOON. THIS
WILL KEEP TEMPS COOLER AND AROUND 60 WHILE THE NORTH WILL BE A BIT
WARMER. THE SFC HIGH WILL MOVE FURTHER DOWN FROM CANADA INTO THE
UPPER MS VALLEY TONIGHT. THIS SHOULD HELP THE NORTHER TIER ALONG WITH
EASTERN COUNTIES GET DOWN TO BELOW 40 DEGREES IN SOME AREAS.
THURSDAY SHOULD BE QUIET AND A BIT WARMER AS UPPER RIDGING BUILDS
OVER THE REGION. WITH SOME DECENT SUNSHINE KEPT HIGHS IN THE 60S
TO LOW 70S.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 330 AM CDT WED MAY 22 2013
THURSDAY NIGHT SOUTHEASTERLY WINDS STILL START PICKING UP OVER THE
WESTERN COUNTIES AS SFC HIGH PRESSURE OVER MN/WI ALONG WITH A
DEVELOPING LOW OVER MT CREATES A DECENT PRESSURE GRADIENT. THE
WINDS WILL HELP KEEP THE WESTERN COUNTIES FROM COMPLETELY
DECOUPLING AND STAY A BIT WARMER WHILE THE EAST WILL AGAIN DROP TO
AROUND 40 DEGREES. SOUTHEASTERLY WINDS WILL CONTINUE INTO FRIDAY
AND FRIDAY NIGHT AS A LEE TROUGH CONTINUES OVER THE WESTERN
PLAINS. MODELS ARE ALL IN FAIRLY DECENT AGREEMENT ON A WEAK
SHORTWAVE COMING OVER THE UPPER RIDGE AND SOME DECENT ISENTROPIC
LIFT PRODUCING SOME PRECIP FRIDAY AFTERNOON INTO FRIDAY NIGHT. AT
THIS POINT THE INSTABILITY SEEMS FAIRLY WEAK WITH SFC BASED CAPE
STAYING WEST OF OUR AREA AND ONLY A LITTLE BIT OF ELEVATED CAPE TO
WORK WITH. INCLUDED A CHANCE OF SHOWERS WITH ISOLATED
THUNDERSTORMS THROUGH FRIDAY NIGHT WITH BEST CHANCES IN OUR WEST.
SATURDAY-TUESDAY...00Z MODELS CONTINUE TO SUGGEST THE SYNOPTIC
PATTERN WILL BE DOMINATED BY LONGWAVE TROUGHING OVER THE WESTERN
US...WITH SOME DEGREE OF MID/UPPER LEVEL RIDGING INTO THE PLAINS
DURING MUCH OF THIS PERIOD. A SERIES OF WEAK UPPER LEVEL SHORTWAVE
TROUGHS EJECTING OUT OF THE BROADER TROUGH TO THE WEST WILL LEAD TO
BOUTS OF SHOWERS OR THUNDERSTORMS ACROSS THE REGION WITHIN THE LOW
TO MID-LEVEL WARM AIR ADVECTION ZONE ASSOCIATED WITH THE INDIVIDUAL
WAVES. WITH THIS TYPE OF PATTERN...CONFIDENCE IN THE
TIMING/PLACEMENT OF INDIVIDUAL WAVES IS LOW...SO CONTINUED TO CARRY
SOME POPS FOR MUCH OF THE PERIOD...ALTHOUGH MANY DRY HOURS ARE
EXPECTED.
THE 00Z GFS/ECMWF SUGGEST A TREND TO A MORE PREDOMINANT ACTIVE
SOUTHWEST FLOW PATTERN ACROSS THE PLAINS TOWARDS THE MIDDLE OF NEXT
WEEK...ALTHOUGH THE GFS IS MORE AMPLIFIED. THE GFS/ECMWF 925 MB
TEMPS RISE TO NEAR 20C ON TUESDAY...SUPPORTING HIGH TEMPS RISING
FROM MAINLY THE 60S OVER THE WEEKEND INTO THE 70S BY MONDAY OR
TUESDAY...WITH LOWS PRIMARILY IN THE 50S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 1024 AM CDT WED MAY 22 2013
THE EDGE OF THE MVFR STRATUS FIELD WITH EMBEDDED LIGHT RAIN WAS
JUST OVER THE KBJI AND KFAR TERMINALS...WITH VFR CONDITIONS
EXPECTED BY 16-17 UTC. OTHERWISE VFR CONDITIONS ARE EXPECTED FOR
KDVL...KGFK AND KTVF FOR THE 12 UTC TAFS. WILL CONTINUE TO MONITOR
STRATUS ACROSS WESTERN ONTARIO AND EASTERN MANITOBA PUSHING
SOUTHEAST. HOWEVER....THE STRATUS IS EXPECTED TO DISSOLVE THROUGH
THE DAY BEFORE REACHING NORTH DAKOTA. NORTHEAST WIND GUSTS OF
20-25 KTS WILL BE COMMON AT ALL TAF SITES LATE THIS MORNING AND
AFTERNOON.
&&
.HYDROLOGY...
ISSUED AT 650 PM CDT TUE MAY 21 2013
RAIN SHOWERS WILL BE ON THE WANE FROM THIS EVENING THROUGH WEDNESDAY
ALLOWING RIVER FORECASTING TO BE MORE RUNOFF AS OPPOSED TO QPF
BASED. RIVER FLOOD WARNINGS REMAIN IN EFFECT AT WALHALLA AND NECHE
ALONG THE PEMBINA RIVER WITH WALHALLA HAVING CRESTED EARLIER.
BIGGEST FORECAST CHANGE IS ALONG PARK RIVER AT GRAFTON WHERE THE
COPIOUS RAINFALL HAS TRIGGERED RAPID STAGE RISES TOWARD MAJOR AND
ULTIMATELY NEAR RECORD FLOOD LEVELS.
RIVER FLOOD WARNINGS ARE NOW IN EFFECT FOR MOST OF THE MAINSTEM RED
AS WELL AS THE SOUTHERN VALLEY MINNESOTA TRIBUTARIES TO THE RED.
THESE POINTS ARE ALL EXPECTED TO ACHIEVE MINOR FLOOD STAGE SAVE FOR
OSLO WHERE MODERATE FLOODING IS FORECAST.
AREAL FLOOD WARNINGS WILL BE IN EFFECT FOR PEMBINA...EASTERN
CAVALIER...AND WALSH COUNTIES THROUGH THURSDAY. BY THEN AREAL
FLOODING SHOULD BECOME LESS OF A CONCERN WITH A DEARTH OF
PRECIPITATION AND THE CHANCE FOR SOME DRYING WITH WARMER
TEMPERATURES.
THE FLASH FLOOD WATCH REMAINS IN EFFECT FOR PARTS OF PEMBINA COUNTY
AS HEAVY RAINFALL OVER THE PAST FEW DAYS HAS CAUSED FLOOD WATERS TO
APPROACH THE TOP OF THE SPILLWAY AT THE RENWICK DAM. WATER
REMAINS VERY HIGH AND IS BEING HELD BACK BY A CONSTRUCTED EARTHEN
LEVEE ON TOP OF THE DAM STRUCTURE. OFFICIALS CONTINUE TO MONITOR
THE DAM AND THE NEW CLAY LEVEE FOR ANY EROSION. THERE ARE SEVERAL
OLD RETENTION DAMS TO THE WEST OF THE RENWICK DAM...AND WITH THE
LARGE AMOUNT OF WATER IN THE AREA THESE DAMS COULD FAIL. IF ONE OF
THESE OLDER DAMS TO THE WEST DID FAIL...THE TEMPORARY LEVEE ON TOP
OF THE RENWICK DAM WOULD NO LONGER BE ABLE TO HOLD BACK
WATER...AND FLOODING WOULD BE IMMINENT FOR THE CITIES OF
AKRA...CAVALIER...AND BATHGATE. THE PEMBINA COUNTY EMERGENCY
MANAGEMENT ANTICIPATES A POSSIBLE BREACH WITHIN THE NEXT 12
HOURS...AND HAVE ORDERED A MANDATORY EVACUATION FOR THE AREA
IMMEDIATELY DOWNSTREAM OF THE RENWICK DAM...INCLUDING THE CITY OF
CAVALIER.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...AYD
SHORT TERM...JR
LONG TERM...JR/MAKOWSKI
AVIATION...AYD
HYDROLOGY...WJB/TG/JH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1012 AM CDT WED MAY 22 2013
.UPDATE...
ISSUED AT 1006 AM CDT WED MAY 22 2013
MADE ONLY MINOR ADJUSTMENTS TO THE CURRENT FORECAST. THE 22.12Z
NAM AND LATEST RAP STILL SUGGEST A SMALL CHANCE FOR A SHOWER IN
THE FAR SOUTHEAST CORNER OF THE FORECAST AREA TODAY. DID NOT
INCREASE RAIN CHANCES IN THAT AREA FOR THE UPDATE...BUT WILL HAVE
TO KEEP AN EYE ON RADAR TRENDS IN CASE A STRAY SHOWER TRIES TO
MOVE IN LATER.
CLOUDS CONTINUE TO CLEAR FROM NORTH TO SOUTH...WITH THE MOST
ABUNDANT CLOUD COVER IN THE SOUTHERN JAMES RIVER VALLEY AS OF MID
MORNING. ADJUSTED NEAR TERM SKY COVER GRIDS TO REFLECT THE
TRENDS...WITH THE FORECAST FOR THIS AFTERNOON STILL ON TRACK.
UPDATE ISSUED AT 641 AM CDT WED MAY 22 2013
SURFACE HIGH PRESSURE CONTINUES TO BUILD INTO THE REGION THIS
MORNING. ENOUGH GRADIENT FLOW HAS DEVELOPED TO MIX OUT MORNING FOG
ACROSS THE NORTHERN PORTIONS OF THE STATE. AS OF THE 11Z
OBS...THERE WAS NO FOG REPORTED ACROSS THE NORTHERN CWA. AS A
RESULT...REMOVED MORNING FOG WORDING FROM THE GRIDS AND ZONES.
FURTHERMORE...REGIONAL RADARS ARE NOT DETECTING ANY SHOWER
ACTIVITY ACROSS THE SOUTHERN CWA. LOWERED MORNING POPS AS A
RESULT. OTHERWISE...ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS
BASED ON CURRENT OBS/TRENDS. THE UPDATED GRIDDED AND TEXT PRODUCTS
HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 343 AM CDT WED MAY 22 2013
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE DRY AND COOL
WEATHER IN THE WAKE OF THE STORM SYSTEM WHICH BROUGHT WIDESPREAD
HEAVY RAINFALL TO MUCH OF WEST AND CENTRAL NORTH DAKOTA THE PAST
SEVERAL DAYS.
CURRENTLY...MOSTLY CLEAR CONDITIONS ACROSS NORTHERN NORTH DAKOTA
WITH HIGH PRESSURE SLOWLY BUILDING SOUTH INTO THE NORTHERN PLAINS.
SCATTERED LIGHT RAIN CONTINUES TO ADVECT WEST-SOUTHWEST FURTHER
SOUTH...STILL UNDER THE INFLUENCE OF THE CLOSED UPPER LOW WHICH IS
MOVING SLOWLY SOUTH AND EAST INTO THE MID/UPPER MISSISSIPPI VALLEY
REGION. PRECIPITATION CHANCES WILL CONTINUE TO DIMINISH FROM NORTH
TO SOUTH AS THE LOW MOVES OUT OF THE REGION...AND SKIES WILL
CONTINUE TO CLEAR FROM NORTH TO SOUTH NOW THROUGH 15Z. WILL MAINTAIN
MORNING FOG NORTH WITH T/TD SPREADS NEARING ZERO AS SKIES
CLEAR...AND SEVERAL OBSERVING SITES REPORTING FOG. WILL MONITOR FOR
POSSIBLE DENSE FOG...HOWEVER WINDS ARE EXPECTED TO INCREASE SHORTLY
AFTER SUNRISE SO DO NOT EXPECT THE DURATION OF THE FOG TO BE VERY
LONG.
THE RIDGE CONTINUES TO BUILD SLOWLY SOUTH ACROSS THE CENTRAL
DAKOTAS TODAY...WITH GENERALLY SUNNY SKIES AND HIGHS IN THE 60S. THE
LATEST 00Z GFS/ECMWF DO GENERATE 100-200 J/KG OF MUCAPE THIS
AFTERNOON/EARLY EVENING ALONG A COLD FRONT PUSHING SOUTH ACROSS
SOUTHERN MANITOBA INTO NORTHEASTERN NORTH DAKOTA. FOR NOW WILL LEAVE
THINGS DRY...BUT COULD SEE A SHOWER OR TWO AROUND THE TURTLE
MOUNTAINS/DEVILS LAKE BASIN AREA.
ANOTHER COOL NIGHT WEDNESDAY THANKS TO CLEAR SKIES...LIGHT
WINDS...AND SFC DEWPOINTS RANGING FROM 35-45. THIS SHOULD RESULT IN
LOW TEMPERATURES AROUND 40 TO 45. SOUTHEAST RETURN FLOW INCREASES
LATE TONIGHT FAR WEST.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 343 AM CDT WED MAY 22 2013
DRY CONDITIONS ARE EXPECTED THURSDAY AS MID/UPPER LEVEL RIDGING
DEVELOPS OVER THE PLAINS. GRADIENT FLOW WILL INCREASE WEST IN
RESPONSE TO AN UPPER LEVEL LOW OVER THE PACIFIC NORTHWEST. WIND
ADVISORY CONDITIONS WILL BE POSSIBLE OVER SOUTHWESTERN NORTH DAKOTA
THURSDAY AFTERNOON/EVENING.
THE MEDIUM RANGE MODELS PROG THE FIRST IMPULSE TO EJECT FROM OF THE
AFOREMENTIONED PACIFIC NORTHWEST LOW OVER WESTERN AND CENTRAL NORTH
DAKOTA FRIDAY. THIS WILL LEAD TO THUNDERSTORM CHANCES DEVELOPING
AREAWIDE BY FRIDAY AFTERNOON.
AN UNSETTLED WEATHER PATTERN WILL CONTINUE THROUGH THE END OF THE
PERIOD. PERSISTENT SOUTHWESTERLY FLOW ALOFT COMBINED WITH GULF OF
MEXICO MOISTURE TAP WILL LEAD TO CHANCES FOR THUNDERSTORMS EACH DAY
THIS WEEKEND THROUGH THE FIRST PART OF NEXT WEEK. THE PERSISTENT
RETURN FLOW SHOULD ALSO ALLOW FOR A GRADUAL WARMING TREND TO DEVELOP
SATURDAY AND CONTINUE THROUGH THE END OF THE PERIOD. BY
TUESDAY...HIGHS SHOULD GENERALLY BE IN THE MID 70S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 641 AM CDT WED MAY 22 2013
VFR CIGS ALL TERMINALS THROUGH THE 12Z TAF PERIOD. EARLY MORNING FOG
POSSIBLE AT KMOT-KISN THROUGH 14Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CK
SHORT TERM...NH
LONG TERM...TM
AVIATION...NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
112 AM CDT WED MAY 22 2013
.UPDATE...
ISSUED AT 112 AM CDT WED MAY 22 2013
ONLY MINIMAL CHANGES WERE NEEDED FOR THIS EARLY MORNING FORECAST
UPDATE. CLOUDS CONTINUE TO CLEAR ACROSS THE NORTH WITH HIGH
PRESSURE SLOWLY BUILDING SOUTH INTO THE NORTHERN PLAINS. ISOLATED
TO SCATTERED LIGHT RAIN WILL PERSIST CENTRAL AND SOUTH...WITH
CHANCES FOR PRECIPITATION DIMINISHING FROM NORTH TO SOUTH NOW
THROUGH 15Z...AS THE UPPER LOW CONTINUES TO MOVE SOUTH AND EAST
TOWARDS THE MISSISSIPPI VALLEY. WILL MAINTAIN FOG IN THE FORECAST
NORTH WITH T/TD SPREADS NEARING ZERO AT SOME LOCATIONS WHERE SKIES
HAVE CLEARED.
UPDATE ISSUED AT 853 PM CDT TUE MAY 21 2013
ISENTROPIC LIFT PERSISTS ACROSS THE SOUTH AND WEST...WITH THE WEST
LIKELY GETTING SOME UPSLOPE COMPONENT AS WELL AS EASTERLY LOW
LEVEL WINDS CONTINUE TO PULL LOW LEVEL MOISTURE INTO THE REGION.
UPPED THE CHANCE OF RAIN SHOWERS TO LIKELY ACROSS PORTIONS OF THE
SOUTH FOR THE EVENING AND EARLY MORNING. SO FAR DO NOT SEE A FIRM
TREND ON CLEARING ACROSS THE NORTH YET. SO HAVE SLOWED THE
PROGRESSION OF CLEARING UNTIL LATER TONIGHT. THIS MAY CAUSE SOME
PROBLEMS WITH FOG FORMATION NORTH UNTIL LATE. UPSLOPE FLOW
CONTRIBUTING TO LIGHT FOG SOUTHWEST THIS EVENING.
UPDATE ISSUED AT 650 PM CDT TUE MAY 21 2013
AT 6 PM CDT...THE CLOUD SHIELD EXTENDS ACROSS ALL OF NORTH DAKOTA
EXCEPT THE FAR NORTHERN TIER OF COUNTIES WHERE BREAKS IN THE
OVERCAST ARE NOW FORMING. AFTER SUNSET THE EAST NORTHEAST FLOW OUT
OF CANADA WITH WARMER TEMPERATURES AND LOWER DEW POINTS WILL
FURTHER ERODE THE CLOUDS. WITH MINOT STILL REPORTED A LIGHT SHOWER
ADDED SPRINKLES FOR SEVERAL HOURS THIS EVENING ALONG AND NORTH OF
LAKE SAKAKAWEA EXCLUDING THE NORTHERN BORDER COUNTIES WHERE
CLEARING WILL DEFINITELY BE FOUND. ACROSS THE SOUTH HALF WILL
STILL SEE SCATTERED SHOWERS THIS EVENING FOLLOWED BY CLEARING
OVERNIGHT. WILL THE NORTH CLEARING BY MIDNIGHT...AND ABUNDANT
SURFACE MOISTURE PRESENT...AREAS OF FOG STILL LOOK REASONABLE.
TEMPERATURE TRENDS LOOK GOOD AND DID NOT TOUCH THEM WITH THIS
FORECAST.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 327 PM CDT TUE MAY 21 2013
THE HIGHLIGHT OF THE SHORT TERM IS THE END OF THE LONG DURATION
RAINFALL EVENT ACROSS THE AREA.
FOR TONIGHT...THE RAP THROUGHOUT THE DAY HAS HAD A GOOD HANDLE ON
THE STRATUS DECK ACROSS THE AREA..AND FOLLOWED ITS LATEST 19 UTC
RUN FOR CLOUD COVER THROUGH THE NIGHT WHICH ADVECTS DRIER AIR
SOUTHWEST AND SCOURS OUT THE STRATUS. DID ADD A MENTION OF FOG TO
THE NORTHWEST AND NORTH CENTRAL WHERE SKIES FIRST CLEAR TONIGHT
AND WINDS BECOME LIGHT...ALLOWING FOR GOOD RADIATIONAL COOLING
INTO THE UPPER 30S AND SATURATION IN LIGHT OF THE RECENT RAINFALL.
A QUIET WEDNESDAY IS FORECAST WITH A SURFACE RIDGE AXIS ACROSS THE
AREA. GIVEN GOOD MODEL AGREEMENT...USED A BLEND OF THE 12 UTC
GEM/GFS/NAM/ECMWF AND 15 UTC SREF FOR ALL FIELDS...WITH GENERALLY
SUNNY SKIES AND HIGHS IN THE 60S.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 327 PM CDT TUE MAY 21 2013
BY WEDNESDAY NIGHT AN UPPER LEVEL SHORTWAVE RIDGE BETWEEN THE
EXITING LOW PRESSURE SYSTEM TO THE EAST...AND THE ESTABLISHED UPPER
LEVEL LOW OVER THE WEST COAST/ROCKIES...WILL BE SITUATED OVER THE
PLAINS OF NORTH AMERICA. AT THE SURFACE...COOL HIGH PRESSURE RIDGE
MOVING SOUTH FROM CANADA NOSES INTO THE DAKOTAS.
BY THURSDAY THE SURFACE PRESSURE GRADIENT INCREASES AS THE
INTENSIFYING SURFACE LOW OVER THE ROCKIES/LEE OF THE ROCKIES SETS UP
A STRONGER SOUTHERLY/SOUTHEASTERLY WIND FLOW ACROSS THE WESTERN
PLAINS. SOUTHEAST WINDS 20 TO 30 MPH CAN BE EXPECTED OVER THE
WESTERN THIRD OF NORTH DAKOTA.
FRIDAY THROUGH THE MEMORIAL DAY WEEKEND...THE LARGE UPPER LEVEL LOW
OVER THE ROCKIES SETS UP A SOUTHWEST FLOW ALOFT OVER NORTH
DAKOTA...AND A SERIES OF UPPER LEVEL IMPULSES WILL TRAVERSE
NORTHEASTWARD ACROSS THE DAKOTAS. THUS A CHANCE OF THUNDERSTORMS
THROUGHOUT THIS PERIOD.
FAIRLY SEASONABLE TEMPERATURES IN THE LONG TERM...WITH HIGHS IN THE
60S AND 70S AND LOWS IN THE 40S AND 50S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 112 AM CDT WED MAY 22 2013
BOUNDARY LAYER MOISTURE CONTINUES TO DECREASE...WITH MAINLY VFR
CIGS NOW AT KDIK-KBIS-KJMS...CLEAR SKIES AT KMOT...AND TRENDING
TOWARDS SKC AT KISN. MAY STILL SEE SOME MVFR CIGS AT THE SOUTHERN
TERMINALS OF KDIK-KBIS-KJMS EARLY THIS MORNING. ALL TERMINALS WILL
BE SKC BY 15-18Z TODAY AND REMAIN SO THROUGH THE REMAINDER OF THE
06Z TAF PERIOD.
&&
.HYDROLOGY...
ISSUED AT 327 PM CDT TUE MAY 21 2013
FLOOD WARNINGS CONTINUE FOR THE PIPESTEM CREEK NEAR PINGREE AND
THE FORECAST POINTS OF TOWNER...BANTRY AND WESTHOPE ON THE SOURIS.
CONTINUING TO MONITOR THE WINTERING RIVER NEAR KARLSRUHE AND THE
WILLOW CREEK NEAR WILLOW CITY WHICH MAY APPROACH FLOOD STAGE IN
THE NEXT 24-48 HOURS. HAVE HELD OFF ON A FLOOD WARNING FOR
NOW...AND WILL WATCH HOW THESE WATERWAYS RESPOND TO RUNOFF.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...NH
SHORT TERM...AYD
LONG TERM...JV
AVIATION...NH
HYDROLOGY...AYD
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
640 AM EDT WED MAY 22 2013
.SYNOPSIS...
LOW PRESSURE WILL MOVE EAST ACROSS THE GREAT LAKES TODAY...WITH A
COLD FRONT MOVING INTO THE OHIO VALLEY TONIGHT. SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE AHEAD OF THIS FRONT. A SECONDARY
TROUGH WILL BRING A CHANCE OF RAIN AGAIN ON THURSDAY. MUCH COLDER
AIR WILL MOVE INTO THE REGION ON FRIDAY...AS HIGH PRESSURE BUILDS
INTO THE OHIO VALLEY THROUGH SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A SOMEWHAT-DISORGANIZED SURFACE LOW IS CURRENTLY LOCATED IN IOWA
AND NORTHERN ILLINOIS. THIS LOW WILL SLOWLY MOVE TO THE EAST
TODAY...STRENGTHENING SLIGHTLY AS IT CROSSES THE SOUTHERN GREAT
LAKES. SOUTH OF THE LOW...A WEAK COLD FRONT WILL MOVE INTO THE ILN
CWA BY EVENING. THIS FRONT IS TOUGH TO PICK OUT ON SURFACE
TEMPERATURE FIELDS...BUT IS A BIT MORE EVIDENT WHEN EXAMINING
THETA-E SLIGHTLY ALOFT...AND ALSO LOOKING FOR SLIGHT WIND SHIFT
FROM SSW TO WSW. AT THE SAME TIME...A CLOSED UPPER LOW OVER THE
NORTHERN MISSISSIPPI VALLEY WILL BEGIN ITS MOVE TO THE EAST...WITH
A SHORTWAVE ROTATING NORTHEAST THROUGH INDIANA AND MICHIGAN. IN
THE RIGHT ENTRANCE REGION OF AN UPPER JET...THE SETUP OVER OHIO
WILL BE FAVORABLE FOR LARGE-SCALE LIFT.
THE STANDARD SUITE OF MODELS (GFS/NAM/CMC/ECMWF) HAS THUS FAR
APPEARED MUCH TOO AGGRESSIVE WITH THE OVERNIGHT PRECIPITATION
FORECAST OVER ILLINOIS AND INDIANA. THIS IS ADMITTEDLY A REGION
WHERE LIFT IS FORECAST TO CONTINUE TO ENHANCE THROUGH MORNING...IN
A REGION OF FALLING HEIGHTS AND A 30-40 KNOT LLJ. DEWPOINTS NORTH
OF THE CURRENT TENNESSEE CONVECTION ARE ABOUT 3-6 DEGREES LOWER THAN
IN THE SOUTHERN STATES...BUT THE AIR MASS COULD NOT BE DESCRIBED
AS PARTICULARLY DRY. AS WAS THE CASE YESTERDAY...THE HRRR HAS THE
CLOSEST APPROXIMATION TO THE CURRENT ACTIVITY. SEVERAL OTHER
CONVECTIVE-ALLOWING MODELS DEPICT QUITE A BIT OF CONVECTION MOVING
INTO THE ILN CWA AS EARLY AS 12Z...WHICH DOES NOT APPEAR REALISTIC
GIVEN THE LACK OF INSTABILITY AND CURRENT RADAR TRENDS. THE
OVERALL CHANCES FOR RAIN IN THE ILN CWA DO NOT APPEAR PARTICULARLY
HIGH THROUGH THE MORNING HOURS...THOUGH SLIGHTLY MORE SO IN THE
WESTERN PART OF THE CWA.
THE MAIN CONCERN FOR THE FORECAST TODAY IS THE POTENTIAL FOR
SEVERE WEATHER THIS AFTERNOON. GIVEN THE WIDE VARIANCE IN THE
HANDLING OF THE CURRENT WEATHER SITUATION...AND THE FACT THAT
THESE MESOSCALE FEATURES WILL BE VERY IMPORTANT IN CONVECTIVE
FORECASTING FOR THIS AFTERNOON...IT IS TOUGH TO TRUST ANY OF THE
SPECIFIC QPF/SIM-RADAR DEPICTIONS FOR THE AFTERNOON HOURS.
TO BEGIN WITH THE BIGGEST LIMITING FACTOR FOR TODAY...INSTABILITY
WILL BE IN QUESTION. GIVEN THE EXPECTED CLOUD COVER...AND EVEN
PRECIPITATION IN SOME PLACES...THE SURFACE TEMP FORECAST IS ON THE
LOW SIDE OF GUIDANCE. GIVEN THE THERMAL PROFILE...MLCAPE WILL
STRUGGLE TO REACH 1000 J/KG...WITH THE MOST INSTABILITY FORECAST
TO BE IN THE SOUTHEASTERN PARTS OF THE CWA. IN THE
NORTHWEST...WHERE TEMPS WILL BE THE COOLEST...INSTABILITY WILL BE
EVEN LESS (500 J/KG OR SO). SOUNDINGS ARE RELATIVELY MOIST THROUGH
THEIR DEPTH...WITH RATHER LOW LCL HEIGHTS (AROUND 2000-3000 FEET
AGL) FORECAST ON THE GFS/NAM (THE RAP13 APPEARS A BIT DRIER).
BECAUSE OF THE MOIST CONDITIONS...THE CAPE PROFILE IS NARROW.
UNLIKE YESTERDAY...THE OVERALL FORCING ENVIRONMENT WILL BE MORE
FAVORABLE FOR CONVECTIVE DEVELOPMENT...EVEN IF INSTABILITY IS
WEAK. WIND SHEAR IS ALSO SOMEWHAT OF A STRENGTH FOR
TODAY...ALTHOUGH MODEL-TO-MODEL ASSESSMENT ON SHEAR VALUES IS NOT
IN AS GOOD OF CONSENSUS AS IS USUALLY THE CASE. MOST OF THE SHEAR
WILL BE FAIRLY UNIDIRECTIONAL (ALL IN THE TOP-RIGHT QUADRANT OF
THE HODOGRAPH)...BUT WITH A DECENT CHANGE IN SPEED. 30-40 KNOTS OF
DEEP LAYER SHEAR WILL BE PRESENT...WITH 15-25 KNOTS IN THE 0-1KM
LAYER. 0-3KM SRH VALUES WILL GET INTO THE 100-200 RANGE...SO THERE
WILL CERTAINLY BE SOME POTENTIAL FOR ROTATING STORMS. THIS COULD
BE ENHANCED BY BOUNDARY INTERACTIONS OR AREAS OF BACKING SURFACE
WINDS (PERHAPS FURTHER NORTH AND CLOSER TO THE SURFACE LOW).
THE LACK OF INSTABILITY...ESPECIALLY IN THE HAIL GROWTH
ZONE...WILL LIMIT THE POTENTIAL FOR LARGE HAIL (PERHAPS OUTSIDE OF
A STRONGER / ROTATING UPDRAFT). THE THREAT FOR STRONG WINDS AND
TORNADOES DOES APPEAR TO EXIST...BUT THE THERMODYNAMIC ENVIRONMENT
SEEMS TO LIMIT THIS FROM BEING A HIGHER-END SEVERE EVENT. A
CLOUDIER/GRUNGIER MORNING WOULD SUPPORT AN ISOLATED SEVERE THREAT
WITH CLUSTERS OF STORMS CAPABLE OF STRONG WINDS AND MAYBE A BIT OF
ROTATION. THE OUTSIDE SHOT FOR TODAY WOULD BE A GREATER DEAL OF
BOUNDARY LAYER DESTABILIZATION (BETWEEN INSOLATION AND MOISTURE
ADVECTION)...WHICH WOULD BRING A GREATER RISK OF ALL THE SEVERE
MODES COMING TO THE TABLE. HOWEVER...GIVEN ALL THE EVIDENCE...THIS
FORECAST WILL LEAN TOWARD THE FORMER SOLUTION. THE HWO WILL FOLLOW
SUIT WITH A RELATIVELY TYPICAL-SOUNDING SEVERE THREAT WORDING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
THE INITIAL COLD FRONT WILL BE CROSSING THE ILN CWA DURING THE
EVENING HOURS...PRODUCING A RELATIVELY SMALL CHANGE IN THE
TEMPERATURE AND WIND FIELDS. BEHIND THE FRONT...PRECIPITATION WILL
BECOME LESS LIKELY...ESPECIALLY IN THE SOUTH AND SOUTHWEST
PORTIONS OF THE CWA.
A SECONDARY TROUGH (BOTH ALOFT AND AT THE SURFACE) WILL BE
ROTATING SOUTHEAST THROUGH THE CWA ON THURSDAY. THIS WILL BRING A
RENEWED CHANCE OF PRECIPITATION...ESPECIALLY IN THE NORTHERN AND
EASTERN PARTS OF THE CWA. INSTABILITY WILL BE VERY WEAK...BUT JUST
ENOUGH FOR SOME RISK OF THUNDER. THE AIR MASS ALOFT WILL BE
INCREASINGLY COLD...HELPING TO LEAD TO THE POSSIBILITY OF
CONVECTIVE SHOWERS.
ALONG WITH THIS ACTIVITY WILL BE A SECONDARY COLD FRONT...MUCH
BETTER DEFINED THAN THE FIRST. A NNW WIND SHIFT WILL ALLOW FOR
COLD ADVECTION TO BEGIN ON THURSDAY (AND ESPECIALLY THURSDAY
NIGHT). AS A RESULT...THE MAX TEMP GRADIENT FOR THURSDAY IS
SOMEWHAT SHARP (ABOUT 10 DEGREES FROM SW TO NE) AND THURSDAY
NIGHT MIN TEMPS MAY GET INTO THE 30S IN THE NORTHERN PORTIONS OF
THE CWA.
WITH DRY HIGH PRESSURE IN PLACE FOR FRIDAY...RELATIVELY TRANQUIL
CONDITIONS ARE EXPECTED.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
DRY WEATHER SHOULD CONTINUE ON SATURDAY FOR MOST OF THE AREA
EXCEPT FOR FAR SOUTHEAST COUNTIES WHERE A DEVELOPING FRONTAL
BOUNDARY MAY CAUSE A FEW SHOWERS.
FOR SUNDAY THROUGH TUESDAY...THAT FRONTAL BOUNDARY IS FORECAST TO
LINGER ACROSS KENTUCKY. THIS PATTERN WILL PROVIDE A CHANCE OF
SHOWERS EACH DAY TO THE SOUTHERN PART OF THE FORECAST AREA...WITH
NORTHERN LOCATIONS ENJOYING A PERIOD OF DRY WEATHER.
SLIGHTLY BELOW NORMAL HIGHS AVERAGING IN THE LOWER 70S ON THURSDAY
WILL BE FOLLOWED BY BELOW NORMAL 60S ON FRIDAY UNDER CLOUDS AND
SHOWERS. TEMPERATURES WILL THEN GRADUALLY REBOUND FROM SATURDAY
ONWARD...WITH HIGHS REACHING THE MID AND UPPER 70S BY TUESDAY.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
REGION WILL REMAIN IN A MOIST SOUTH TO SOUTHWEST FLOW AT THE
SURFACE AND ALOFT AS THE CENTER OF AN UPPER LEVEL LOW PIVOTS
SOUTHEAST TOWARD THE WESTERN GREAT LAKES. AS THE LOW MOVES
SOUTHEAST...A SURFACE COLD FRONT WILL PUSH EAST THROUGH OUR AREA
TONIGHT.
LATEST ANALYSIS AND MODELS INDICATE THAT OUR AREA IS STILL IN AN
INSTABILITY MINIMUM THIS MORNING. AS SUCH...THE LOW LEVEL JET
THAT IS OVER THE AREA MAY PRODUCE SOME SCATTERED SHOWERS THIS
MORNING.
FOR THIS AFTERNOON INTO THIS EVENING...THE PROSPECTS OF SHOWERS
AND THUNDERSTORMS WILL INCREASE AS DAYTIME HEATING INTERACTS WITH
LARGE SCALE SYNOPTIC LIFT. BEST CHANCE FOR WIDESPREAD SHOWERS AND
THUNDERSTORMS WILL BE FROM MID AFTERNOON INTO THE EVENING HOURS.
HAVE PLACED THIS IN THE TAFS WITH A PREDOMINANT MVFR -SHRA AND A
VCTS/CB. AS STORMS BECOME MORE APPARENT AND CAN BE TRACKED ON
RADAR...TAFS WILL BE FINED TUNED ACCORDINGLY. WITH A MOIST
AIRMASS...SOME LOCAL MVFR CIGS AND IFR VSBYS WILL BE POSSIBLE IN
THUNDERSTORMS. DAYTIME HEATING/MIXING WILL PRODUCE SOUTH/SOUTHWEST
WINDS OF 12-16 KNOTS WITH GUSTS UP TO 30 KNOTS.
FOR TONIGHT...THE COLD FRONT IS FORECAST TO PUSH EAST ACROSS THE
REGION. LARGE SCALE LIFT DECREASES AS DOES THE INSTABILITY.
HOWEVER...MODELS INDICATE THAT THERE COULD BE A BAND OF SHOWERS
AND A FEW EMBEDDED THUNDERSTORMS ALONG AND AHEAD OF THE FRONT.
HAVE INDICATED THIS WITH A VCSH AS THUNDERSTORMS CHANCES WILL WANE
BETWEEN 01Z AND 06Z. AFTER FRONTAL PASSAGE...THERE SHOULD BE A
REPRIEVE IN PCPN BUT LOW LEVEL MOISTURE WILL REMAIN. IT IS UNCLEAR
AT THIS TIME IF MVFR CEILINGS WILL DEVELOP BEHIND THE FRONT SO
HAVE LEFT THEM AT VFR FOR NOW.
OUTLOOK...MVFR CONDITIONS POSSIBLE WITH SHOWERS AND EMBEDDED
THUNDERSTORMS THURSDAY INTO THURSDAY EVENING.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...CONIGLIO
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
430 AM EDT WED MAY 22 2013
.SYNOPSIS...
LOW PRESSURE WILL MOVE EAST ACROSS THE GREAT LAKES TODAY...WITH A
COLD FRONT MOVING INTO THE OHIO VALLEY TONIGHT. SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE AHEAD OF THIS FRONT. A SECONDARY
TROUGH WILL BRING A CHANCE OF RAIN AGAIN ON THURSDAY. MUCH COLDER
AIR WILL MOVE INTO THE REGION ON FRIDAY...AS HIGH PRESSURE BUILDS
INTO THE OHIO VALLEY THROUGH SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A SOMEWHAT-DISORGANIZED SURFACE LOW IS CURRENTLY LOCATED IN IOWA
AND NORTHERN ILLINOIS. THIS LOW WILL SLOWLY MOVE TO THE EAST
TODAY...STRENGTHENING SLIGHTLY AS IT CROSSES THE SOUTHERN GREAT
LAKES. SOUTH OF THE LOW...A WEAK COLD FRONT WILL MOVE INTO THE ILN
CWA BY EVENING. THIS FRONT IS TOUGH TO PICK OUT ON SURFACE
TEMPERATURE FIELDS...BUT IS A BIT MORE EVIDENT WHEN EXAMINING
THETA-E SLIGHTLY ALOFT...AND ALSO LOOKING FOR SLIGHT WIND SHIFT
FROM SSW TO WSW. AT THE SAME TIME...A CLOSED UPPER LOW OVER THE
NORTHERN MISSISSIPPI VALLEY WILL BEGIN ITS MOVE TO THE EAST...WITH
A SHORTWAVE ROTATING NORTHEAST THROUGH INDIANA AND MICHIGAN. IN
THE RIGHT ENTRANCE REGION OF AN UPPER JET...THE SETUP OVER OHIO
WILL BE FAVORABLE FOR LARGE-SCALE LIFT.
THE STANDARD SUITE OF MODELS (GFS/NAM/CMC/ECMWF) HAS THUS FAR
APPEARED MUCH TOO AGGRESSIVE WITH THE OVERNIGHT PRECIPITATION
FORECAST OVER ILLINOIS AND INDIANA. THIS IS ADMITTEDLY A REGION
WHERE LIFT IS FORECAST TO CONTINUE TO ENHANCE THROUGH MORNING...IN
A REGION OF FALLING HEIGHTS AND A 30-40 KNOT LLJ. DEWPOINTS NORTH
OF THE CURRENT TENNESSEE CONVECTION ARE ABOUT 3-6 DEGREES LOWER THAN
IN THE SOUTHERN STATES...BUT THE AIR MASS COULD NOT BE DESCRIBED
AS PARTICULARLY DRY. AS WAS THE CASE YESTERDAY...THE HRRR HAS THE
CLOSEST APPROXIMATION TO THE CURRENT ACTIVITY. SEVERAL OTHER
CONVECTIVE-ALLOWING MODELS DEPICT QUITE A BIT OF CONVECTION MOVING
INTO THE ILN CWA AS EARLY AS 12Z...WHICH DOES NOT APPEAR REALISTIC
GIVEN THE LACK OF INSTABILITY AND CURRENT RADAR TRENDS. THE
OVERALL CHANCES FOR RAIN IN THE ILN CWA DO NOT APPEAR PARTICULARLY
HIGH THROUGH THE MORNING HOURS...THOUGH SLIGHTLY MORE SO IN THE
WESTERN PART OF THE CWA.
THE MAIN CONCERN FOR THE FORECAST TODAY IS THE POTENTIAL FOR
SEVERE WEATHER THIS AFTERNOON. GIVEN THE WIDE VARIANCE IN THE
HANDLING OF THE CURRENT WEATHER SITUATION...AND THE FACT THAT
THESE MESOSCALE FEATURES WILL BE VERY IMPORTANT IN CONVECTIVE
FORECASTING FOR THIS AFTERNOON...IT IS TOUGH TO TRUST ANY OF THE
SPECIFIC QPF/SIM-RADAR DEPICTIONS FOR THE AFTERNOON HOURS.
TO BEGIN WITH THE BIGGEST LIMITING FACTOR FOR TODAY...INSTABILITY
WILL BE IN QUESTION. GIVEN THE EXPECTED CLOUD COVER...AND EVEN
PRECIPITATION IN SOME PLACES...THE SURFACE TEMP FORECAST IS ON THE
LOW SIDE OF GUIDANCE. GIVEN THE THERMAL PROFILE...MLCAPE WILL
STRUGGLE TO REACH 1000 J/KG...WITH THE MOST INSTABILITY FORECAST
TO BE IN THE SOUTHEASTERN PARTS OF THE CWA. IN THE
NORTHWEST...WHERE TEMPS WILL BE THE COOLEST...INSTABILITY WILL BE
EVEN LESS (500 J/KG OR SO). SOUNDINGS ARE RELATIVELY MOIST THROUGH
THEIR DEPTH...WITH RATHER LOW LCL HEIGHTS (AROUND 2000-3000 FEET
AGL) FORECAST ON THE GFS/NAM (THE RAP13 APPEARS A BIT DRIER).
BECAUSE OF THE MOIST CONDITIONS...THE CAPE PROFILE IS NARROW.
UNLIKE YESTERDAY...THE OVERALL FORCING ENVIRONMENT WILL BE MORE
FAVORABLE FOR CONVECTIVE DEVELOPMENT...EVEN IF INSTABILITY IS
WEAK. WIND SHEAR IS ALSO SOMEWHAT OF A STRENGTH FOR
TODAY...ALTHOUGH MODEL-TO-MODEL ASSESSMENT ON SHEAR VALUES IS NOT
IN AS GOOD OF CONSENSUS AS IS USUALLY THE CASE. MOST OF THE SHEAR
WILL BE FAIRLY UNIDIRECTIONAL (ALL IN THE TOP-RIGHT QUADRANT OF
THE HODOGRAPH)...BUT WITH A DECENT CHANGE IN SPEED. 30-40 KNOTS OF
DEEP LAYER SHEAR WILL BE PRESENT...WITH 15-25 KNOTS IN THE 0-1KM
LAYER. 0-3KM SRH VALUES WILL GET INTO THE 100-200 RANGE...SO THERE
WILL CERTAINLY BE SOME POTENTIAL FOR ROTATING STORMS. THIS COULD
BE ENHANCED BY BOUNDARY INTERACTIONS OR AREAS OF BACKING SURFACE
WINDS (PERHAPS FURTHER NORTH AND CLOSER TO THE SURFACE LOW).
THE LACK OF INSTABILITY...ESPECIALLY IN THE HAIL GROWTH
ZONE...WILL LIMIT THE POTENTIAL FOR LARGE HAIL (PERHAPS OUTSIDE OF
A STRONGER / ROTATING UPDRAFT). THE THREAT FOR STRONG WINDS AND
TORNADOES DOES APPEAR TO EXIST...BUT THE THERMODYNAMIC ENVIRONMENT
SEEMS TO LIMIT THIS FROM BEING A HIGHER-END SEVERE EVENT. A
CLOUDIER/GRUNGIER MORNING WOULD SUPPORT AN ISOLATED SEVERE THREAT
WITH CLUSTERS OF STORMS CAPABLE OF STRONG WINDS AND MAYBE A BIT OF
ROTATION. THE OUTSIDE SHOT FOR TODAY WOULD BE A GREATER DEAL OF
BOUNDARY LAYER DESTABILIZATION (BETWEEN INSOLATION AND MOISTURE
ADVECTION)...WHICH WOULD BRING A GREATER RISK OF ALL THE SEVERE
MODES COMING TO THE TABLE. HOWEVER...GIVEN ALL THE EVIDENCE...THIS
FORECAST WILL LEAN TOWARD THE FORMER SOLUTION. THE HWO WILL FOLLOW
SUIT WITH A RELATIVELY TYPICAL-SOUNDING SEVERE THREAT WORDING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
THE INITIAL COLD FRONT WILL BE CROSSING THE ILN CWA DURING THE
EVENING HOURS...PRODUCING A RELATIVELY SMALL CHANGE IN THE
TEMPERATURE AND WIND FIELDS. BEHIND THE FRONT...PRECIPITATION WILL
BECOME LESS LIKELY...ESPECIALLY IN THE SOUTH AND SOUTHWEST
PORTIONS OF THE CWA.
A SECONDARY TROUGH (BOTH ALOFT AND AT THE SURFACE) WILL BE
ROTATING SOUTHEAST THROUGH THE CWA ON THURSDAY. THIS WILL BRING A
RENEWED CHANCE OF PRECIPITATION...ESPECIALLY IN THE NORTHERN AND
EASTERN PARTS OF THE CWA. INSTABILITY WILL BE VERY WEAK...BUT JUST
ENOUGH FOR SOME RISK OF THUNDER. THE AIR MASS ALOFT WILL BE
INCREASINGLY COLD...HELPING TO LEAD TO THE POSSIBILITY OF
CONVECTIVE SHOWERS.
ALONG WITH THIS ACTIVITY WILL BE A SECONDARY COLD FRONT...MUCH
BETTER DEFINED THAN THE FIRST. A NNW WIND SHIFT WILL ALLOW FOR
COLD ADVECTION TO BEGIN ON THURSDAY (AND ESPECIALLY THURSDAY
NIGHT). AS A RESULT...THE MAX TEMP GRADIENT FOR THURSDAY IS
SOMEWHAT SHARP (ABOUT 10 DEGREES FROM SW TO NE) AND THURSDAY
NIGHT MIN TEMPS MAY GET INTO THE 30S IN THE NORTHERN PORTIONS OF
THE CWA.
WITH DRY HIGH PRESSURE IN PLACE FOR FRIDAY...RELATIVELY TRANQUIL
CONDITIONS ARE EXPECTED.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
DRY WEATHER SHOULD CONTINUE ON SATURDAY FOR MOST OF THE AREA
EXCEPT FOR FAR SOUTHEAST COUNTIES WHERE A DEVELOPING FRONTAL
BOUNDARY MAY CAUSE A FEW SHOWERS.
FOR SUNDAY THROUGH TUESDAY...THAT FRONTAL BOUNDARY IS FORECAST TO
LINGER ACROSS KENTUCKY. THIS PATTERN WILL PROVIDE A CHANCE OF
SHOWERS EACH DAY TO THE SOUTHERN PART OF THE FORECAST AREA...WITH
NORTHERN LOCATIONS ENJOYING A PERIOD OF DRY WEATHER.
SLIGHTLY BELOW NORMAL HIGHS AVERAGING IN THE LOWER 70S ON THURSDAY
WILL BE FOLLOWED BY BELOW NORMAL 60S ON FRIDAY UNDER CLOUDS AND
SHOWERS. TEMPERATURES WILL THEN GRADUALLY REBOUND FROM SATURDAY
ONWARD...WITH HIGHS REACHING THE MID AND UPPER 70S BY TUESDAY.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
REGION WILL REMAIN IN A MOIST SOUTH TO SOUTHWEST FLOW AT THE
SURFACE AND ALOFT AS THE CENTER OF AN UPPER LEVEL LOW PIVOTS
SOUTHEAST TOWARD THE WESTERN GREAT LAKES. AS THE LOW MOVES
SOUTHEAST...A SURFACE COLD FRONT WILL PUSH EAST THROUGH OUR AREA
TONIGHT.
LATEST ANALYSIS AND MODELS INDICATE THAT OUR AREA IS IN AN
INSTABILITY MINIMUM EARLY THIS MORNING. AS SUCH...THE LOW LEVEL
JET THAT IS FORECAST TO DEVELOP OVERNIGHT SHOULD PRODUCE SOME
SCATTERED SHOWERS AND PERHAPS A RUMBLE OF THUNDER.
FOR TODAY INTO THIS EVENING...THE PROSPECTS OF SHOWERS AND
THUNDERSTORMS WILL INCREASE THROUGH THE DAY AS DAYTIME HEATING
INTERACTS WITH LARGE SCALE SYNOPTIC LIFT. BEST CHANCE FOR
WIDESPREAD SHOWERS AND THUNDERSTORMS WILL BE FROM MID AFTERNOON
INTO THE EVENING HOURS. HAVE PLACED THIS IN THE TAFS WITH A
PREDOMINANT MVFR -SHRA AND A VCTS/CB. AS STORMS BECOME MORE APPARENT
AND CAN BE TRACKED ON RADAR...TAFS WILL BE FINED TUNED
ACCORDINGLY. WITH A MOIST AIRMASS...SOME LOCAL MVFR CIGS AND IFR
VSBYS WILL BE POSSIBLE IN THUNDERSTORMS. DAYTIME HEATING/MIXING
WILL PRODUCE SOUTH/SOUTHWEST WINDS OF 10-15 KNOTS WITH GUSTS
AROUND 25 KNOTS.
FOR TONIGHT...A COLD FRONT IS FORECAST TO PUSH EAST ACROSS THE
REGION. LARGE SCALE LIFT DECREASES AS DOES THE INSTABILITY.
HOWEVER...MODELS INDICATE THAT THERE COULD BE A BAND OF SHOWERS
AND A FEW EMBEDDED THUNDERSTORMS ALONG AND AHEAD OF THE FRONT.
HAVE INDICATED THIS WITH A VCSH AS THUNDERSTORMS CHANCES WILL WANE
BETWEEN 01Z AND 06Z. AFTER FRONTAL PASSAGE...THERE SHOULD BE A
REPRIEVE IN PCPN BUT LOW LEVEL MOISTURE WILL LIKELY RESULT IN SOME
MVFR CIGS.
OUTLOOK...MVFR CONDITIONS POSSIBLE THURSDAY INTO THURSDAY EVENING.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...CONIGLIO
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
412 AM EDT WED MAY 22 2013
.SYNOPSIS...
LOW PRESSURE WILL MOVE EAST ACROSS THE GREAT LAKES TODAY...WITH A
COLD FRONT MOVING INTO THE OHIO VALLEY TONIGHT. SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE AHEAD OF THIS FRONT. A SECONDARY
TROUGH WILL BRING A CHANCE OF RAIN AGAIN ON THURSDAY. MUCH COLDER
AIR WILL MOVE INTO THE REGION ON FRIDAY...AS HIGH PRESSURE BUILDS
INTO THE OHIO VALLEY THROUGH SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A SOMEWHAT-DISORGANIZED SURFACE LOW IS CURRENTLY LOCATED IN IOWA
AND NORTHERN ILLINOIS. THIS LOW WILL SLOWLY MOVE TO THE EAST
TODAY...STRENGTHENING SLIGHTLY AS IT CROSSES THE SOUTHERN GREAT
LAKES. SOUTH OF THE LOW...A WEAK COLD FRONT WILL MOVE INTO THE ILN
CWA BY EVENING. THIS FRONT IS TOUGH TO PICK OUT ON SURFACE
TEMPERATURE FIELDS...BUT IS A BIT MORE EVIDENT WHEN EXAMINING
THETA-E SLIGHTLY ALOFT...AND ALSO LOOKING FOR SLIGHT WIND SHIFT
FROM SSW TO WSW. AT THE SAME TIME...A CLOSED UPPER LOW OVER THE
NORTHERN MISSISSIPPI VALLEY WILL BEGIN ITS MOVE TO THE EAST...WITH
A SHORTWAVE ROTATING NORTHEAST THROUGH INDIANA AND MICHIGAN. IN
THE RIGHT ENTRANCE REGION OF AN UPPER JET...THE SETUP OVER OHIO
WILL BE FAVORABLE FOR LARGE-SCALE LIFT.
THE STANDARD SUITE OF MODELS (GFS/NAM/CMC/ECMWF) HAS THUS FAR
APPEARED MUCH TOO AGGRESSIVE WITH THE OVERNIGHT PRECIPITATION
FORECAST OVER ILLINOIS AND INDIANA. THIS IS ADMITTEDLY A REGION
WHERE LIFT IS FORECAST TO CONTINUE TO ENHANCE THROUGH MORNING...IN
A REGION OF FALLING HEIGHTS AND A 30-40 KNOT LLJ. DEWPOINTS NORTH
OF THE CURRENT TENNESSEE CONVECTION ARE ABOUT 3-6 DEGREES LOWER THAN
IN THE SOUTHERN STATES...BUT THE AIR MASS COULD NOT BE DESCRIBED
AS PARTICULARLY DRY. AS WAS THE CASE YESTERDAY...THE HRRR HAS THE
CLOSEST APPROXIMATION TO THE CURRENT ACTIVITY. SEVERAL OTHER
CONVECTIVE-ALLOWING MODELS DEPICT QUITE A BIT OF CONVECTION MOVING
INTO THE ILN CWA AS EARLY AS 12Z...WHICH DOES NOT APPEAR REALISTIC
GIVEN THE LACK OF INSTABILITY AND CURRENT RADAR TRENDS. THE
OVERALL CHANCES FOR RAIN IN THE ILN CWA DO NOT APPEAR PARTICULARLY
HIGH THROUGH THE MORNING HOURS...THOUGH SLIGHTLY MORE SO IN THE
WESTERN PART OF THE CWA.
THE MAIN CONCERN FOR THE FORECAST TODAY IS THE POTENTIAL FOR
SEVERE WEATHER THIS AFTERNOON. GIVEN THE WIDE VARIANCE IN THE
HANDLING OF THE CURRENT WEATHER SITUATION...AND THE FACT THAT
THESE MESOSCALE FEATURES WILL BE VERY IMPORTANT IN CONVECTIVE
FORECASTING FOR THIS AFTERNOON...IT IS TOUGH TO TRUST ANY OF THE
SPECIFIC QPF/SIM-RADAR DEPICTIONS FOR THE AFTERNOON HOURS.
TO BEGIN WITH THE BIGGEST LIMITING FACTOR FOR TODAY...INSTABILITY
WILL BE IN QUESTION. GIVEN THE EXPECTED CLOUD COVER...AND EVEN
PRECIPITATION IN SOME PLACES...THE SURFACE TEMP FORECAST IS ON THE
LOW SIDE OF GUIDANCE. GIVEN THE THERMAL PROFILE...MLCAPE WILL
STRUGGLE TO REACH 1000 J/KG...WITH THE MOST INSTABILITY FORECAST
TO BE IN THE SOUTHEASTERN PARTS OF THE CWA. IN THE
NORTHWEST...WHERE TEMPS WILL BE THE COOLEST...INSTABILITY WILL BE
EVEN LESS (500 J/KG OR SO). SOUNDINGS ARE RELATIVELY MOIST THROUGH
THEIR DEPTH...WITH RATHER LOW LCL HEIGHTS (AROUND 2000-3000 FEET
AGL) FORECAST ON THE GFS/NAM (THE RAP13 APPEARS A BIT DRIER).
BECAUSE OF THE MOIST CONDITIONS...THE CAPE PROFILE IS NARROW.
UNLIKE YESTERDAY...THE OVERALL FORCING ENVIRONMENT WILL BE MORE
FAVORABLE FOR CONVECTIVE DEVELOPMENT...EVEN IF INSTABILITY IS
WEAK. WIND SHEAR IS ALSO SOMEWHAT OF A STRENGTH FOR
TODAY...ALTHOUGH MODEL-TO-MODEL ASSESSMENT ON SHEAR VALUES IS NOT
IN AS GOOD OF CONSENSUS AS IS USUALLY THE CASE. MOST OF THE SHEAR
WILL BE FAIRLY UNIDIRECTIONAL (ALL IN THE TOP-RIGHT QUADRANT OF
THE HODOGRAPH)...BUT WITH A DECENT CHANGE IN SPEED. 30-40 KNOTS OF
DEEP LAYER SHEAR WILL BE PRESENT...WITH 15-25 KNOTS IN THE 0-1KM
LAYER. 0-3KM SRH VALUES WILL GET INTO THE 100-200 RANGE...SO THERE
WILL CERTAINLY BE SOME POTENTIAL FOR ROTATING STORMS. THIS COULD
BE ENHANCED BY BOUNDARY INTERACTIONS OR AREAS OF BACKING SURFACE
WINDS (PERHAPS FURTHER NORTH AND CLOSER TO THE SURFACE LOW).
THE LACK OF INSTABILITY...ESPECIALLY IN THE HAIL GROWTH
ZONE...WILL LIMIT THE POTENTIAL FOR LARGE HAIL (PERHAPS OUTSIDE OF
A STRONGER / ROTATING UPDRAFT). THE THREAT FOR STRONG WINDS AND
TORNADOES DOES APPEAR TO EXIST...BUT THE THERMODYNAMIC ENVIRONMENT
SEEMS TO LIMIT THIS FROM BEING A HIGHER-END SEVERE EVENT. A
CLOUDIER/GRUNGIER MORNING WOULD SUPPORT AN ISOLATED SEVERE THREAT
WITH CLUSTERS OF STORMS CAPABLE OF STRONG WINDS AND MAYBE A BIT OF
ROTATION. THE OUTSIDE SHOT FOR TODAY WOULD BE A GREATER DEAL OF
BOUNDARY LAYER DESTABILIZATION (BETWEEN INSOLATION AND MOISTURE
ADVECTION)...WHICH WOULD BRING A GREATER RISK OF ALL THE SEVERE
MODES COMING TO THE TABLE. HOWEVER...GIVEN ALL THE EVIDENCE...THIS
FORECAST WILL LEAN TOWARD THE FORMER SOLUTION. THE HWO WILL FOLLOW
SUIT WITH A RELATIVELY TYPICAL-SOUNDING SEVERE THREAT WORDING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
THE SHORT TERM DISCUSSION WILL BE UPDATED SHORTLY.
PREVIOUS DISCUSSION FOLLOWS >
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO OVERSPREAD THE FA
DURING THE DAYTIME HOURS ON WEDNESDAY. THERE IS STILL SOME
QUESTION AS TO THE SEVERE POTENTIAL FOR WEDNESDAY. THERE IS BETTER
INSTABILITY ACROSS EASTERN PORTIONS OF THE FA FOR WEDNESDAY. IN
ADDITION STORMS WILL HOLD OFF A LITTLE LONGER ACROSS EASTERN
PORTIONS OF THE FA WHICH WILL ALLOW FOR SOME MORE HEATING. DUE TO
THIS BELIEVE THAT THE BETTER SEVERE THREAT WILL BE ACROSS EASTERN
PORTIONS OF THE FA FOR WEDNESDAY WITH THE MAIN THREATS BEING
DAMAGING WINDS AND LARGE HAIL. PRECIPITATION COVERAGE ACROSS THE AREA
WILL DIMINISH DURING THE LATE EVENING HOURS HOWEVER SOME ISOLATED
ACTIVITY WILL STILL REMAIN POSSIBLE. ADDITIONAL SHOWERS AND
THUNDERSTORMS WILL BEGIN TO MOVE INTO WESTERN PORTIONS OF THE FA
LATE IN THE OVERNIGHT HOURS WEDNESDAY NIGHT AS THE COLD FRONT
APPROACHES THE AREA.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
SHOWERS ARE LIKELY TO DEVELOP MAINLY OVER NORTHERN LOCATIONS ON
THURSDAY AS A SHARP UPPER TROUGH AND COOL AIRMASS PUSH THROUGH THE
GREAT LAKES AND OHIO VALLEY. FRIDAY WILL BE DRY AND COOL WITH HIGH
PRESSURE CROSSING THE AREA. DRY WEATHER SHOULD CONTINUE ON SATURDAY
FOR MOST OF THE AREA EXCEPT FOR FAR SOUTHEAST COUNTIES WHERE A
DEVELOPING FRONTAL BOUNDARY MAY CAUSE A FEW SHOWERS.
FOR SUNDAY THROUGH TUESDAY...THAT FRONTAL BOUNDARY IS FORECAST TO
LINGER ACROSS KENTUCKY. THIS PATTERN WILL PROVIDE A CHANCE OF
SHOWERS EACH DAY TO THE SOUTHERN PART OF THE FORECAST AREA...WITH
NORTHERN LOCATIONS ENJOYING A PERIOD OF DRY WEATHER.
SLIGHTLY BELOW NORMAL HIGHS AVERAGING IN THE LOWER 70S ON THURSDAY
WILL BE FOLLOWED BY BELOW NORMAL 60S ON FRIDAY UNDER CLOUDS AND
SHOWERS. TEMPERATURES WILL THEN GRADUALLY REBOUND FROM SATURDAY
ONWARD...WITH HIGHS REACHING THE MID AND UPPER 70S BY TUESDAY.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
REGION WILL REMAIN IN A MOIST SOUTH TO SOUTHWEST FLOW AT THE
SURFACE AND ALOFT AS THE CENTER OF AN UPPER LEVEL LOW PIVOTS
SOUTHEAST TOWARD THE WESTERN GREAT LAKES. AS THE LOW MOVES
SOUTHEAST...A SURFACE COLD FRONT WILL PUSH EAST THROUGH OUR AREA
TONIGHT.
LATEST ANALYSIS AND MODELS INDICATE THAT OUR AREA IS IN AN
INSTABILITY MINIMUM EARLY THIS MORNING. AS SUCH...THE LOW LEVEL
JET THAT IS FORECAST TO DEVELOP OVERNIGHT SHOULD PRODUCE SOME
SCATTERED SHOWERS AND PERHAPS A RUMBLE OF THUNDER.
FOR TODAY INTO THIS EVENING...THE PROSPECTS OF SHOWERS AND
THUNDERSTORMS WILL INCREASE THROUGH THE DAY AS DAYTIME HEATING
INTERACTS WITH LARGE SCALE SYNOPTIC LIFT. BEST CHANCE FOR
WIDESPREAD SHOWERS AND THUNDERSTORMS WILL BE FROM MID AFTERNOON
INTO THE EVENING HOURS. HAVE PLACED THIS IN THE TAFS WITH A
PREDOMINANT MVFR -SHRA AND A VCTS/CB. AS STORMS BECOME MORE APPARENT
AND CAN BE TRACKED ON RADAR...TAFS WILL BE FINED TUNED
ACCORDINGLY. WITH A MOIST AIRMASS...SOME LOCAL MVFR CIGS AND IFR
VSBYS WILL BE POSSIBLE IN THUNDERSTORMS. DAYTIME HEATING/MIXING
WILL PRODUCE SOUTH/SOUTHWEST WINDS OF 10-15 KNOTS WITH GUSTS
AROUND 25 KNOTS.
FOR TONIGHT...A COLD FRONT IS FORECAST TO PUSH EAST ACROSS THE
REGION. LARGE SCALE LIFT DECREASES AS DOES THE INSTABILITY.
HOWEVER...MODELS INDICATE THAT THERE COULD BE A BAND OF SHOWERS
AND A FEW EMBEDDED THUNDERSTORMS ALONG AND AHEAD OF THE FRONT.
HAVE INDICATED THIS WITH A VCSH AS THUNDERSTORMS CHANCES WILL WANE
BETWEEN 01Z AND 06Z. AFTER FRONTAL PASSAGE...THERE SHOULD BE A
REPRIEVE IN PCPN BUT LOW LEVEL MOISTURE WILL LIKELY RESULT IN SOME
MVFR CIGS.
OUTLOOK...MVFR CONDITIONS POSSIBLE THURSDAY INTO THURSDAY EVENING.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...CONIGLIO
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS TULSA OK
1157 PM CDT TUE MAY 21 2013
.DISCUSSION...
THE 06Z TAF DISCUSSION IS INCLUDED BELOW.
&&
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
CLOUDS WILL BE CLEARING SOON AT ALL OF THE TAF SITES...AND WITH
THE SATURATED CONDITIONS NEAR THE GROUND...THERE WILL BE SOME FOG
DEVELOPMENT. I THINK CONDITIONS WILL BE WORSE DOWN AT KMLC AND
KFSM WHERE RECENT HEAVY RAINS HAVE OCCURRED. NEVERTHELESS...VSBYS
WILL DROP DOWN TO IFR AND POSSIBLY LOWER FOR A TIME. VFR
CONDITIONS WILL PREVAIL ON WEDNESDAY EVERYWHERE.
LACY
&&
.PREV DISCUSSION... /ISSUED 917 PM CDT TUE MAY 21 2013/
..UPDATE...
DISCUSSION...
PRECIPITATION HAS MOVED EAST OUT OF THE ENTIRE FORECAST AREA
QUICKLY THIS EVENING. SKIES ARE CLEARING FROM THE WEST AS DRY AIR
PUSHES IN BEHIND THE DEPARTING UPPER SYSTEM. HAVE REMOVED POPS FOR
ALL BUT THE EASTERN MOST SLIVER OF THE CWA. HAVE ALSO CLEARED
SKIES A LITTLE FASTER OVERNIGHT. HAVE LEFT FORECAST MINIMUM
TEMPERATURES AS THEY WERE. UPDATED PRODUCTS HAVE ALL BEEN SENT.
PREV DISCUSSION... /ISSUED 648 PM CDT TUE MAY 21 2013/
DISCUSSION...
THE 00Z TAF DISCUSSION IS INCLUDED BELOW.
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
RAIN/STORMS ARE MOVING OUT...WITH SKIES CLEARING THIS EVENING. DUE
TO THE RECENT RAINS AND WET GROUND...SOME PATCHY FOG WILL LIKELY
DEVELOP. THINK THE FOG WILL BE MOST PROMINENT OVER SOUTHEAST OK
WHERE THE HEAVIEST RAINS FELL SO I HAVE BROUGHT KMLC DOWN TO IFR
VSBY. THE HYDROLAPSE BECOMES UNFAVORABLE FOR WIDESPREAD DENSE FOG
TONIGHT AS THE BOUNDARY LAYER DRIES OUT AFTER MIDNIGHT. SO FOR
NOW STAYED CONSERVATIVE ON VSBYS AT THE OTHER SITES.
LACY
PREV DISCUSSION... /ISSUED 312 PM CDT TUE MAY 21 2013/
DISCUSSION...
LINEAR MCS THAT HAS FORMED AHEAD OF COMPACT UPPER SYSTEM SURGING
ACROSS OK/TX IS CURRENTLY MOVING ACROSS PORTIONS OF SERN OK. THE
LINE HAS BEEN STRONG/MARGINALLY SEVERE SO FAR...AND STILL COULD SEE
SOME 60+ MPH WIND GUSTS OVER THE NEXT FEW HOURS. HRRR HAS SHOWN A
VERY GOOD HANDLE ON THE COMPLEX...WITH THE LEADING EDGE EXITING OUR
FORECAST AREA AROUND 22Z-23Z. CURRENT FLASH FLOOD WATCH IS SET TO
EXPIRE AT 00Z...ALTHOUGH MAY EXTEND IT A FEW MORE HOURS. WILL TAKE A
LAST LOOK AT RADAR BEFORE FINAL DECISION. OTHERWISE...PARTIALLY
CLEARING SKIES ALONG WITH DRIER LOW-LEVEL AIR WILL ALLOW TEMPS TO
FALL INTO THE 50S FOR MUCH OF THE AREA.
WEAK SURFACE BOUNDARY MAY BE PRESENT ACROSS THE AREA ON
WEDNESDAY...ALTHOUGH ATMOSPHERE SHOULD BE TOO DRY AND WORKED OVER TO
SUPPORT PRECIPITATION.
UPPER PATTERN WILL BECOME INCREASINGLY AMPLIFIED BY MID-TO-LATE
WEEK...WITH RIDGING THROUGH THE PLAINS SANDWICHED BY DEEP UPPER
SYSTEMS ACROSS THE PAC NW AND THE EAST COAST. MODELS SUGGEST THAT
SEVERAL WEAK WAVES WILL MOVE INTO THE MEAN RIDGE POSITION...WITH AT
LEAST SOME LOW POPS WARRANTED ACROSS WRN SECTIONS IN THE VERY
WARM/MOIST AIRMASS.
UPPER RIDGE SHOULD FLATTEN SOME ACROSS THE SRN/CENTRL PLAINS GOING
INTO THE WEEKEND. WITH THE FORECAST AREA ALONG THE SRN EDGE OF THE
STRONGER UPPER FLOW...SHOULD SEE PERIODIC SHOWER/THUNDERSTORM
EPISODES...ESPECIALLY ACROSS NE OK/NW AR. TOUGH TO PINPOINT WHICH
DAY WILL HAVE THE BEST CHANCES...SO HAVE MAINTAINED GENERAL CHANCE
POPS FOR ABOUT THE NRN HALF OF THE AREA FOR THE WEEKEND AND INTO
EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 55 81 58 78 / 10 0 10 20
FSM 58 83 62 81 / 20 10 10 10
MLC 55 83 61 84 / 10 0 10 20
BVO 52 81 54 77 / 10 0 10 20
FYV 54 79 55 76 / 20 10 10 10
BYV 56 79 55 77 / 30 10 10 10
MKO 55 82 60 79 / 10 10 10 20
MIO 54 78 56 78 / 10 10 10 10
F10 55 82 61 79 / 10 0 10 20
HHW 60 85 64 85 / 10 0 10 20
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...30
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
506 PM EDT WED MAY 22 2013
.SYNOPSIS...
AN APPROACHING UPPER LEVEL TROUGH WILL CONTINUE TO INFLUENCE THE
REGION THROUGH THURSDAY. A COLD FRONT MOVES THROUGH THE AREA
THURSDAY NIGHT...BEFORE A COOLER AND DRIER AIRMASS SETTLES IN FOR
THE WEEKEND AND MODIFIES THROUGH THE EARLY PART OF NEXT WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 430 PM...INCREASED POPS ACROSS THE UPSTATE OF SOUTH CAROLINA
AND THE PIEDMONT OF NORTH CAROLINA DURING THE OVERNIGHT HOURS AS
SHORT TERM CONVECTIVE MODEL GUIDANCE CONTINUES WIDESPREAD CONVECTION
ACROSS THE ABOVE MENTIONED REGIONS THROUGH 10Z THURSDAY. ALSO
TOUCHED UP SKY AND TEMP GRIDS. OTHERWISE...NO OTHER CHANGES WERE
MADE.
REMAINDER OF PREVIOUS DISCUSSION...
AS OF MID AFTERNOON...A BROKEN BAND OF SHOWERS AND THUNDERSTORMS WAS
LOCATED JUST EAST OF THE BLUE RIDGE IN NC FROM I-40 NEWD...WITH
OTHER STORMS POPPING UP ACROSS THE HIGHER TERRAIN AIDED BY
DIFFERENTIAL HEATING. EXPECT THE STORMS TO BECOME MORE NUMEROUS
ACROSS THE MTNS THROUGH LATE AFTERNOON...WITH THAT CONVECTION MOVING
EAST OVER THE FOOTHILLS AND PIEDMONT INTO THE EVENING. POP HAS BEEN
ADJUSTED ACCORDINGLY. SOME OF THESE STORMS WILL PRODUCE LARGE HAIL
AND DAMAGING WIND GUSTS. HIGH TEMPS STILL LOOK OKAY.
FOR TONIGHT...THE CONVECTION ALLOWING MODELS SUGGEST THAT ANOTHER
ROUND OF STORMS WILL FIRE TO THE WEST AND THEN MOVE EAST INTO THE
FCST AREA IN THE EARLY EVENING. THE HRRR AND 4KM WRF PAINT A SIMILAR
PICTURE WITH NUMEROUS STORMS OVER THE WESTERN HALF OF THE FCST AREA
THROUGH MID TO LATE EVENING. A SHORT WAVE MOVING AROUND THE UPPER
TROF...COMBINED WITH SOME UPPER DIVERGENCE...SHOULD PROVIDE THE
NECESSARY SUPPORT FOR THIS CONVECTION TO THRIVE. WITH THAT IN
MIND...THE POP WAS RAISED TO LIKELY OVER THE WESTERN HALF. AFTER
SOME LOSS OF HEATING...THE STORMS SHOULD BECOME A BIT LESS NUMEROUS
OVER THE NC PIEDMONT. AT THAT POINT...THE POP WAS KEPT BELOW 50 PCT
ONLY BECAUSE OF SOME UNCERTAINTY GIVEN BY THE CONVECTION HAVING NOT
YET DEVELOPED AS OF 18Z. MIN TEMPS SHOULD REMAIN MILD.
THE COLD FRONT WILL MOVE IN FROM THE WEST ON THURSDAY...MOST LIKELY
OVER THE MTNS IN THE MORNING AND THEN MOVING OUT OVER THE FOOTHILLS
IN THE AFTERNOON. NEW CONVECTION SHOULD DEVELOP ALONG THE FRONT
MAINLY OVER THE PIEDMONT IN THE AFTERNOON. THIS IS TRICKY BECAUSE OF
THE LIKELIHOOD OF WIDESPREAD DEBRIS CLOUDINESS INTO THE EARLY
AFTERNOON THAT WOULD LIMIT CONVECTION. THINK THE MTNS STAND A CHANCE
BECAUSE OF THE FRONT EARLY IN THE DAY. THE UPSTATE AND NE GEORGIA
HAS THE LEAST FAVORABLE ENVIRONMENT...SO A 20 PCT POP WAS KEPT. THE
PIEDMONT HAS A BETTER CHANCE AHEAD OF THE FRONT SO A LIKELY POP WAS
CARRIED OVER THE EASTERN ZONES FOR A TIME. SEVERE STORMS ARE
POSSIBLE...BUT MORE LIKELY TO THE EAST OF I-77. HIGH TEMPS WILL BE
AFEW DEGREES COOLER.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 230 PM WEDNESDAY...A SURFACE COLD FRONT SHOULD BE LOCATED NEAR
THE EDGE OF OUR WESTERN NORTH CAROLINA PIEDMONT EARLY THURSDAY
EVENING. THIS LINES UP WELL WITH THE SHORT TERM SUITE OF MODELS...
AND LINES UP WITH WITH AN AXIS OF DPVA WHICH SHOULD BE CROSSING THAT
REGION LATE IN THE DAY/EARLY EVENING. CONVECTIVE ALLOWING MODELS
ALSO DEPICT THIS TREND AND IS SUPPORTED BY INSTABILITY LINGERING
ACROSS THAT AREA. AS A RESULT WE WILL HAVE A CORRIDOR OF LOWER
CHANCE POPS IN OUR EASTERN FORECAST AREA (FA) UNTIL AROUND DARK OR
SO.
A SECOND AREA OF PRECIPITATION FOR THURSDAY NIGHT WILL BE IN THE NC
MOUNTAINS WHERE ANOTHER LOBE OF ENERGY...EMBEDDED IN A SHARPENING H5
TROF...CROSSES THE AREA. WE WILL CARRY CHANCE POPS IN THE NC
MOUNTAINS THURSDAY NIGHT AND FRIDAY MORNING...IN A CONTINUALLY
DEEPENING FORCED UPPER AIR PATTERN. ALTHOUGH THE SHARPENING TROF
CROSSES ALL OF OUR REGION FRIDAY...THE ATMOSPHERE LOOKS TO DRY FOR
ANY PRECIPITATION.
MEANWHILE THE H85 ISALLOBARIC PATTERN WAS INDICATING SIGNIFICANT
CROSS CONTOURS OF THERMAL STRUCTURE AND HEIGHTS FRIDAY. THIS
SUGGESTS AT LEAST SIGNIFICANT COLD AIR ADVECTION (ESPECIALLY JUST
ABOVE THE SURFACE) AND MIXING DOWN. WE HAVE FOLLOWED BUFKIT
INFORMATION FOR WIND GUSTS FRIDAY...AND IN ALL LIKELIHOOD WE WILL
NEED SOME TYPE OF WIND HEADLINE FRIDAY FOR PART OF OUR FAA...
PARTICULARLY IN THE AFTERNOON.
HIGH PRESSURE WILL EDGE TOWARD THE REGION FRIDAY NIGHT...WHICH WILL
BRING A COOL/COLD NIGHT AROUND THE AREA. SOME MOUNTAIN LOCATIONS TO
DIP INTO THE 30S...BUT BELIEVE ENOUGH MIXING SHOULD PREVENT FROST
DUE TO THE LINGERING GRADIENT OF HIGH PRESSURE OFF TO THE NORTHWEST
AND LOW PRESSURE MOVING UP THE EASTERN SEABOARD. HOWEVER WE WILL
HAVE TO MONITOR TRENDS.
HIGH PRESSURE TO HOLD SWAY SATURDAY WITH A PLEASANT DAY ON
TAP.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 225 PM WEDNESDAY...RATHER GOOD AGREEMENT IS HAD IN THE UPPER
LEVEL OMEGA PATTERN OVER THE EXT RANGE. THE 12Z GFS IS A BIT OF AN
OUTLIER AND SHARPENS THE EAST COAST TROF AND SUBSEQUENT DEEP NW/LY
FLOW GRADIENT MORESO THAN THE OTHER OP MODELS...BUT NOT ENOUGH FOR A
SIGFNT LLVL RESPONSE. AT THE SFC...THERE ARE MAJOR DIFFERENCES
EVOLVING WITH THE SYNOPTIC PATTERN...THUS A LESS THAN AVG
CONFIDENCE IS HAD AS THE EXT RANGE PROGRESSES.
HIGH PRESSURE CONTINUES TO BUILD IN FROM THE NORTH SUN AND KEEPS
THINGS DRY. HIGH TEMPS WILL BE A LITTLE BELOW NORMAL WITH A
REINFORCING CP AIRMASS MIXING IN. THE LLVL FLOW BECOMES DEFINED
SW/LY MON AS THE ATL HIGH NUDGES IN. THIS WILL ALSO ENABLE A WARM
FRONT OR STATIONARY TO PERHAPS IMPINGE UPON THE REGION MON NIGHT
INTO TUE. THERE IS LOW CONFIDENCE IN THIS FEATURE...HOWEVER...AS THE
GFS KEEPS ANY FRONTOGENESIS WELL TO THE NORTH OF THE REGION WITH A
WEAK TROF BUILDING INTO THE SFC SE RIDGE...WHILE THE ECMWF HAS THE
WARM FRONT STALLING OUT ACROSS THE CWFA DURING THE DAY TUE INTO WED.
RIGHT NOW...POPS HAVE BEEN CONTINUED IN THE LOW END CHANCE RANGE MON
THROUGH TUE...AND A DRIER HPC BLEND WAS MAINTAINED FOR WED.
SOUNDINGS SHOW VERY LITTLE SBCAPE DEVELOPING MON AS THE UPPER FLOW
KEEPS A SUBSIDENCE INVERSION IN PLACE...HOWEVER A RELATIVE WEAKENING
ALOFT TUE SHOULD ENABLE THE DEVELOPMENT OF SOME ENHANCE CONVECTION
AND TSTMS. MAX TEMPS WILL WARM EACH DAY MON THROUGH THE PERIOD TO A
LITTLE ABOVE NORMAL IN GOOD SW/LY FLOW AND INSOLATION.
&&
.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
AT KCLT FOR 21Z UPDATE...THINK CONDITIONS WILL REMAIN VFR INTO THE
EARLY EVENING...WITH BKN CLOUD BASES AROUND THE 035 TO 045 RANGE.
THE LATEST GUIDANCE...INCLUDING THE CONVECTIVE MODELS...IS FOCUSING
MORE ON THE MID TO LATE EVENING ACROSS THE NC PIEDMONT FOR WHEN A
BROKEN BAND OF STORMS WILL MOVE THROUGH. REMOVED PREVIOUS PROB30 AND
WENT WITH A 4HR TEMPO GROUP FOR TSRA WITH MVFR VISB. THE FRONT
SHOULD STAY WEST OF THE TERMINAL THROUGH EARLY AFTERNOON AND WILL
SERVE AS A TRIGGER FOR NEW DEVELOPMENT BY LATE MORNING
THURSDAY...THUS ANOTHER PROB30 GROUP TOWARD THE END OF THE PERIOD.
AS A RESULT...WIND DIRECTION SHOULD REMAIN S TO SW.
ELSEWHERE...VFR FOR THE TIME BEING. CONVECTIVE CLOUD BASES SHOULD
REMAIN IN THE 035 TO 050 RANGE...MAINLY FEW TO SCT...AND THEN SHOULD
DROP INTO THE MVFR RANGE THIS EVENING AS CONVECTION BECOMES MORE
NUMEROUS. THE FRONT WILL PROBABLY MAKE IT INTO THE MTNS THURSDAY
MORNING SO THE WIND AT KAVL WAS SHIFTED TO NW. ANOTHER ROUND OF
SHOWERS AND STORMS IS POSSIBLE OVER NC THURSDAY LATE IN THE PERIOD.
OUTLOOK... CEILING AND VISIBILITY RESTRICTIONS IN SCATTERED SHOWERS
AND THUNDERSTORMS AGAIN THURSDAY AFTN/EVE. GENERALLY VFR WEATHER
FRIDAY AND SATURDAY.
CONFIDENCE TABLE...
21-03Z 03-09Z 09-15Z 15-21Z
KCLT HIGH 100% HIGH 87% HIGH 88% MED 79%
KGSP HIGH 92% MED 71% HIGH 91% HIGH 100%
KAVL MED 77% HIGH 81% HIGH 86% HIGH 100%
KHKY HIGH 80% LOW 56% MED 72% HIGH 83%
KGMU HIGH 92% MED 69% HIGH 88% HIGH 100%
KAND HIGH 93% MED 74% HIGH 88% 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...CDG/PM/WIMBERLEY
SHORT TERM...TS
LONG TERM...SBK
AVIATION...CDG/PM/WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
245 PM EDT WED MAY 22 2013
.SYNOPSIS...
AN APPROACHING UPPER LEVEL TROUGH WILL CONTINUE TO INFLUENCE THE
REGION THROUGH THURSDAY. A COLD FRONT MOVES THROUGH THE AREA
THURSDAY NIGHT...BEFORE A COOLER AND DRIER AIRMASS SETTLES IN FOR
THE WEEKEND AND MODIFIES THROUGH THE EARLY PART OF NEXT WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF MID AFTERNOON...A BROKEN BAND OF SHOWERS AND THUNDERSTORMS WAS
LOCATED JUST EAST OF THE BLUE RIDGE IN NC FROM I-40 NEWD...WITH
OTHER STORMS POPPING UP ACROSS THE HIGHER TERRAIN AIDED BY
DIFFERENTIAL HEATING. EXPECT THE STORMS TO BECOME MORE NUMEROUS
ACROSS THE MTNS THROUGH LATE AFTERNOON...WITH THAT CONVECTION MOVING
EAST OVER THE FOOTHILLS AND PIEDMONT INTO THE EVENING. POP HAS BEEN
ADJUSTED ACCORDINGLY. SOME OF THESE STORMS WILL PRODUCE LARGE HAIL
AND DAMAGING WIND GUSTS. HIGH TEMPS STILL LOOK OKAY.
FOR TONIGHT...THE CONVECTION ALLOWING MODELS SUGGEST THAT ANOTHER
ROUND OF STORMS WILL FIRE TO THE WEST AND THEN MOVE EAST INTO THE
FCST AREA IN THE EARLY EVENING. THE HRRR AND 4KM WRF PAINT A SIMILAR
PICTURE WITH NUMEROUS STORMS OVER THE WESTERN HALF OF THE FCST AREA
THROUGH MID TO LATE EVENING. A SHORT WAVE MOVING AROUND THE UPPER
TROF...COMBINED WITH SOME UPPER DIVERGENCE...SHOULD PROVIDE THE
NECESSARY SUPPORT FOR THIS CONVECTION TO THRIVE. WITH THAT IN
MIND...THE POP WAS RAISED TO LIKELY OVER THE WESTERN HALF. AFTER
SOME LOSS OF HEATING...THE STORMS SHOULD BECOME A BIT LESS NUMEROUS
OVER THE NC PIEDMONT. AT THAT POINT...THE POP WAS KEPT BELOW 50 PCT
ONLY BECAUSE OF SOME UNCERTAINTY GIVEN BY THE CONVECTION HAVING NOT
YET DEVELOPED AS OF 18Z. MIN TEMPS SHOULD REMAIN MILD.
THE COLD FRONT WILL MOVE IN FROM THE WEST ON THURSDAY...MOST LIKELY
OVER THE MTNS IN THE MORNING AND THEN MOVING OUT OVER THE FOOTHILLS
IN THE AFTERNOON. NEW CONVECTION SHOULD DEVELOP ALONG THE FRONT
MAINLY OVER THE PIEDMONT IN THE AFTERNOON. THIS IS TRICKY BECAUSE OF
THE LIKELIHOOD OF WIDESPREAD DEBRIS CLOUDINESS INTO THE EARLY
AFTERNOON THAT WOULD LIMIT CONVECTION. THINK THE MTNS STAND A CHANCE
BECAUSE OF THE FRONT EARLY IN THE DAY. THE UPSTATE AND NE GEORGIA
HAS THE LEAST FAVORABLE ENVIRONMENT...SO A 20 PCT POP WAS KEPT. THE
PIEDMONT HAS A BETTER CHANCE AHEAD OF THE FRONT SO A LIKELY POP WAS
CARRIED OVER THE EASTERN ZONES FOR A TIME. SEVERE STORMS ARE
POSSIBLE...BUT MORE LIKELY TO THE EAST OF I-77. HIGH TEMPS WILL BE
AFEW DEGREES COOLER.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 230 PM WEDNESDAY...A SURFACE COLD FRONT SHOULD BE LOCATED NEAR
THE EDGE OF OUR WESTERN NORTH CAROLINA PIEDMONT EARLY THURSDAY
EVENING. THIS LINES UP WELL WITH THE SHORT TERM SUITE OF MODELS...
AND LINES UP WITH WITH AN AXIS OF DPVA WHICH SHOULD BE CROSSING THAT
REGION LATE IN THE DAY/EARLY EVENING. CONVECTIVE ALLOWING MODELS
ALSO DEPICT THIS TREND AND IS SUPPORTED BY INSTABILITY LINGERING
ACROSS THAT AREA. AS A RESULT WE WILL HAVE A CORRIDOR OF LOWER
CHANCE POPS IN OUR EASTERN FORECAST AREA (FA) UNTIL AROUND DARK OR
SO.
A SECOND AREA OF PRECIPITATION FOR THURSDAY NIGHT WILL BE IN THE NC
MOUNTAINS WHERE ANOTHER LOBE OF ENERGY...EMBEDDED IN A SHARPENING H5
TROF...CROSSES THE AREA. WE WILL CARRY CHANCE POPS IN THE NC
MOUNTAINS THURSDAY NIGHT AND FRIDAY MORNING...IN A CONTINUALLY
DEEPENING FORCED UPPER AIR PATTERN. ALTHOUGH THE SHARPENING TROF
CROSSES ALL OF OUR REGION FRIDAY...THE ATMOSPHERE LOOKS TO DRY FOR
ANY PRECIPITATION.
MEANWHILE THE H85 ISALLOBARIC PATTERN WAS INDICATING SIGNIFICANT
CROSS CONTOURS OF THERMAL STRUCTURE AND HEIGHTS FRIDAY. THIS
SUGGESTS AT LEAST SIGNIFICANT COLD AIR ADVECTION (ESPECIALLY JUST
ABOVE THE SURFACE) AND MIXING DOWN. WE HAVE FOLLOWED BUFKIT
INFORMATION FOR WIND GUSTS FRIDAY...AND IN ALL LIKELIHOOD WE WILL
NEED SOME TYPE OF WIND HEADLINE FRIDAY FOR PART OF OUR FAA...
PARTICULARLY IN THE AFTERNOON.
HIGH PRESSURE WILL EDGE TOWARD THE REGION FRIDAY NIGHT...WHICH WILL
BRING A COOL/COLD NIGHT AROUND THE AREA. SOME MOUNTAIN LOCATIONS TO
DIP INTO THE 30S...BUT BELIEVE ENOUGH MIXING SHOULD PREVENT FROST
DUE TO THE LINGERING GRADIENT OF HIGH PRESSURE OFF TO THE NORTHWEST
AND LOW PRESSURE MOVING UP THE EASTERN SEABOARD. HOWEVER WE WILL
HAVE TO MONITOR TRENDS.
HIGH PRESSURE TO HOLD SWAY SATURDAY WITH A PLEASANT DAY ON
TAP.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 225 PM WEDNESDAY...RATHER GOOD AGREEMENT IS HAD IN THE UPPER
LEVEL OMEGA PATTERN OVER THE EXT RANGE. THE 12Z GFS IS A BIT OF AN
OUTLIER AND SHARPENS THE EAST COAST TROF AND SUBSEQUENT DEEP NW/LY
FLOW GRADIENT MORESO THAN THE OTHER OP MODELS...BUT NOT ENOUGH FOR A
SIGFNT LLVL RESPONSE. AT THE SFC...THERE ARE MAJOR DIFFERENCES
EVOLVING WITH THE SYNOPTIC PATTERN...THUS A LESS THAN AVG
CONFIDENCE IS HAD AS THE EXT RANGE PROGRESSES.
HIGH PRESSURE CONTINUES TO BUILD IN FROM THE NORTH SUN AND KEEPS
THINGS DRY. HIGH TEMPS WILL BE A LITTLE BELOW NORMAL WITH A
REINFORCING CP AIRMASS MIXING IN. THE LLVL FLOW BECOMES DEFINED
SW/LY MON AS THE ATL HIGH NUDGES IN. THIS WILL ALSO ENABLE A WARM
FRONT OR STATIONARY TO PERHAPS IMPINGE UPON THE REGION MON NIGHT
INTO TUE. THERE IS LOW CONFIDENCE IN THIS FEATURE...HOWEVER...AS THE
GFS KEEPS ANY FRONTOGENESIS WELL TO THE NORTH OF THE REGION WITH A
WEAK TROF BUILDING INTO THE SFC SE RIDGE...WHILE THE ECMWF HAS THE
WARM FRONT STALLING OUT ACROSS THE CWFA DURING THE DAY TUE INTO WED.
RIGHT NOW...POPS HAVE BEEN CONTINUED IN THE LOW END CHANCE RANGE MON
THROUGH TUE...AND A DRIER HPC BLEND WAS MAINTAINED FOR WED.
SOUNDINGS SHOW VERY LITTLE SBCAPE DEVELOPING MON AS THE UPPER FLOW
KEEPS A SUBSIDENCE INVERSION IN PLACE...HOWEVER A RELATIVE WEAKENING
ALOFT TUE SHOULD ENABLE THE DEVELOPMENT OF SOME ENHANCE CONVECTION
AND TSTMS. MAX TEMPS WILL WARM EACH DAY MON THROUGH THE PERIOD TO A
LITTLE ABOVE NORMAL IN GOOD SW/LY FLOW AND INSOLATION.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...THINK CONDITIONS WILL REMAIN VFR INTO THE EARLY
EVENING...WITH SCT CLOUD BASES AROUND THE 035 TO 045 RANGE. THE
LATEST GUIDANCE...INCLUDING THE CONVECTIVE MODELS...IS FOCUSING MORE
ON THE MID TO LATE EVENING ACROSS THE NC PIEDMONT FOR WHEN A BROKEN
BAND OF STORMS WILL MOVE THROUGH. WILL CARRY A PROB30 FOR THIS IN
THE 03Z TO 06Z TIME FRAME. EXPECT ADJUSTMENTS TO THE PROB AND MIGHT
HAVE TO INCLUDE A TEMPO LATER IN THE DAY. WITH COOLING...THE CLOUD
BASES SHOULD FALL INTO MVFR RANGE LATE THIS EVENING AND STAY THERE
THROUGH EARLY AFTERNOON ON THURSDAY. FOG COULD BECOME A PROBLEM
AROUND DAYBREAK IF SIGNIFICANT RAIN HAPPENS LATE TONIGHT.
OTHERWISE...THE VSBY WAS KEPT ABOVE 5 MILES. THE FRONT SHOULD STAY
WEST OF THE TERMINAL THROUGH EARLY AFTERNOON AND WILL SERVE AS A
TRIGGER FOR NEW DEVELOPMENT BY LATE MORNING THURSDAY...THUS ANOTHER
PROB30 GROUP TOWARD THE END OF THE PERIOD. AS A RESULT...WIND
DIRECTION SHOULD REMAIN S TO SW.
ELSEWHERE...VFR FOR THE TIME BEING. CONVECTIVE CLOUD BASES SHOULD
REMAIN IN THE 035 TO 050 RANGE...MAINLY FEW TO SCT...AND THEN SHOULD
DROP INTO THE MVFR RANGE THIS EVENING AS CONVECTION BECOMES MORE
NUMEROUS. THE FRONT WILL PROBABLY MAKE IT INTO THE MTNS THURSDAY
MORNING SO THE WIND AT KAVL WAS SHIFTED TO NW. ANOTHER ROUND OF
SHOWERS AND STORMS IS POSSIBLE OVER NC THURSDAY LATE IN THE PERIOD.
OUTLOOK... CEILING AND VISIBILITY RESTRICTIONS IN SCATTERED SHOWERS
AND THUNDERSTORMS AGAIN THURSDAY AFTN/EVE. GENERALLY VFR WEATHER
FRIDAY AND SATURDAY.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT HIGH 86% HIGH 100% HIGH 86% HIGH 90%
KGSP HIGH 100% MED 79% HIGH 87% HIGH 97%
KAVL HIGH 93% MED 77% HIGH 81% HIGH 97%
KHKY HIGH 93% MED 73% LOW 54% HIGH 80%
KGMU HIGH 100% MED 79% HIGH 83% HIGH 94%
KAND HIGH 100% HIGH 80% HIGH 82% HIGH 95%
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...PM
SHORT TERM...TS
LONG TERM...SBK
AVIATION...PM
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
205 PM CDT WED MAY 22 2013
.MESOSCALE UPDATE...FOR THIS AFTERNOON AND EVENING...
VIS SATELLITE IMAGERY CONTINUES TO SHOW A BROKEN CLOUD DECK OVER
MIDDLE TN THAT HAS BEEN LIMITING DIURNAL HEATING UNTIL THE LAST
HOUR OR SO. WITH THE CLOUD DECK DETERIORATING ENOUGH TO ALLOW
SUNLIGHT TO POKE THROUGH...INSTABILITY AND LOW LEVEL
THERMODYNAMICS ARE INCREASING. SPC MESOANALYSIS SHOWS A 3 HOUR
CAPE CHANGE ACROSS MUCH OF THE MID STATE OF ABOUT 400-600 J/KG
WITH A CORRESPONDING DECREASE IN CONVECTIVE INHIBITION. FORECAST
CAPE VALUES APPEAR TO BE BEST OUT EAST ON THE CUMBERLAND BUT
GREATER THAN 1500 J/KG ACROSS THE MID STATE. FORECAST SOUNDINGS ARE
UNCAPPED WITH STRONG LOW LEVEL LAPSE RATES AS WELL. RUC FORECAST
SOUNDINGS SHOW CONVECTIVE TEMPERATURES BEING REACHED BETWEEN NOW
AND THE NEXT HOUR SO EXPECT INITIATION OF CONVECTION TO BEGIN VERY
SOON.
DYNAMICALLY SPEAKING...UPPER LEVEL FORCING IS INCREASING
ASSOCIATED WITH HEIGHT FALLS OVER WESTERN TENNESSEE. THE BEST
UPPER LEVEL SUPPORT IS COINCIDENT WITH THE RRQ OF THE NEGATIVELY
TILTED 300 MB LOW. AS THIS SHORTWAVE CONTINUES TO SWING AROUND
AND AMPLIFY THE UPPER LEVEL LIFT IN ASSOCIATION WITH THE
LOW...THE POSSIBILITY FOR SEVERE HAIL AND WINDS WILL INCREASE.
EXPECT ISOLATED TO SCATTERED STRONG TO POSSIBLY SEVERE STORMS
BEGIN OUT EAST WHERE BETTER THERMODYNAMIC INSTABILITY IS BEST. IN
THE NEXT FEW HOURS AS LOCATIONS OUT WEST CONTINUE TO
DESTABILIZE...THE FOCUS FOR SEVERE POTENTIAL WILL TRANSITION TO
THE FRONT WHERE UPPER LEVEL SUPPORT AND SHEAR IS BEST. BELIEVE LARGE
HAIL AND DAMAGING STRAIGHT LINE WINDS ARE THE BIGGEST THREATS.
&&
.PREV DISCUSSION... /ISSUED 1137 AM CDT WED MAY 22 2013/
AVIATION 18Z DISCUSSION...
WELL STACKED TROUGH TO PASS EASTWARD THROUGH THE MID STATE TODAY.
CONVECTION EXPECTED TO DEVELOP WITH THE BEST COVERAGE ACROSS
EASTERN MIDDLE TN. A FEW STORMS COULD REACH STRONG TO SEVERE
LIMITS. AFT 00Z...CONVECTION WILL DIMINISH BUT CLOUDINESS AND SOME
LATE NIGHT FOG WILL PERSIST. REDUCED VSBYS AND CIGS AOB 1KFT WILL
OCCUR AT CSV AFT 06Z. IMPROVING CONDITIONS AREA WIDE AFT 12Z.
PREV DISCUSSION... /ISSUED 1037 AM CDT WED MAY 22 2013/
UPDATE...
HAVE UPDATED THE FORECAST TO PROVIDE A LITTLE BETTER TIMING OF THE
EXPECTED CONVECTION THIS AFTN. REST OF THE FCST APPEARS IN GOOD
SHAPE.
MORNING UA ANALYSIS DEPICTS A SEASONALLY STRONG SOMEWHAT
NEGATIVELY TILTED MID LVL SHORT WAVE ACRS ARKANSAS APPROACHING THE
AREA. THE REGION IS ALSO ENTERING THE RR QUAD OF A RELATIVELY
STRONG UPPER LVL JET STREAK WHICH WILL ENHANCE LIFT THIS
AFTERNOON. THERMODYNAMICS DON`T LOOK ALL THAT IMPRESSIVE RIGHT NOW
AS THE ATMOS IS PRETTY WORKED OVER AND A FAIR AMOUNT OF DEBRIS
CLOUD HAS HUNG ARND. MORNING SOUNDING DEPICTS A DEEP DRY/CAPPED
LOWER ATMOSPHERE THAT IS INHIBITING ANY DEVELOPMENT. DO EXPECT A
LITTLE MORE SUN TO DEVELOP...AND A SLOW INCRS IN LLVL MSTR IS
STILL ANTICIPATED. THE COMBINATION OF COOLING MID LVL TEMPS AND A
WARMING/MOISTENING LOWER ATMOS WILL ALLOW CONVECTION TO INITIATE
MOST LIKELY RIGHT ALONG A COLD FRONT PROGGED TO CROSS THE AREA IN
THE MID/LATE AFTN. DECENT SPEED SHEAR IN PLACE SO EXPECT ACTIVITY
TO ORIENT IN A LINE WITH DAMAGING STRAIGHT LINE WINDS POSSIBLE.
SPC CONTINUES A VERY LOW CHANCE OF A TORNADO AS WELL.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
12
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1137 AM CDT WED MAY 22 2013
.AVIATION 18Z DISCUSSION...
WELL STACKED TROUGH TO PASS EASTWARD THROUGH THE MID STATE TODAY.
CONVECTION EXPECTED TO DEVELOP WITH THE BEST COVERAGE ACROSS
EASTERN MIDDLE TN. A FEW STORMS COULD REACH STRONG TO SEVERE
LIMITS. AFT 00Z...CONVECTION WILL DIMINISH BUT CLOUDINESS AND SOME
LATE NIGHT FOG WILL PERSIST. REDUCED VSBYS AND CIGS AOB 1KFT WILL
OCCUR AT CSV AFT 06Z. IMPROVING CONDITIONS AREA WIDE AFT 12Z.
&&
.PREV DISCUSSION... /ISSUED 1037 AM CDT WED MAY 22 2013/
UPDATE...
HAVE UPDATED THE FORECAST TO PROVIDE A LITTLE BETTER TIMING OF THE
EXPECTED CONVECTION THIS AFTN. REST OF THE FCST APPEARS IN GOOD
SHAPE.
MORNING UA ANALYSIS DEPICTS A SEASONALLY STRONG SOMEWHAT
NEGATIVELY TILTED MID LVL SHORT WAVE ACRS ARKANSAS APPROACHING THE
AREA. THE REGION IS ALSO ENTERING THE RR QUAD OF A RELATIVELY
STRONG UPPER LVL JET STREAK WHICH WILL ENHANCE LIFT THIS
AFTERNOON. THERMODYNAMICS DON`T LOOK ALL THAT IMPRESSIVE RIGHT NOW
AS THE ATMOS IS PRETTY WORKED OVER AND A FAIR AMOUNT OF DEBRIS
CLOUD HAS HUNG ARND. MORNING SOUNDING DEPICTS A DEEP DRY/CAPPED
LOWER ATMOSPHERE THAT IS INHIBITING ANY DEVELOPMENT. DO EXPECT A
LITTLE MORE SUN TO DEVELOP...AND A SLOW INCRS IN LLVL MSTR IS
STILL ANTICIPATED. THE COMBINATION OF COOLING MID LVL TEMPS AND A
WARMING/MOISTENING LOWER ATMOS WILL ALLOW CONVECTION TO INITIATE
MOST LIKELY RIGHT ALONG A COLD FRONT PROGGED TO CROSS THE AREA IN
THE MID/LATE AFTN. DECENT SPEED SHEAR IN PLACE SO EXPECT ACTIVITY
TO ORIENT IN A LINE WITH DAMAGING STRAIGHT LINE WINDS POSSIBLE.
SPC CONTINUES A VERY LOW CHANCE OF A TORNADO AS WELL.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1037 AM CDT WED MAY 22 2013
.UPDATE...
HAVE UPDATED THE FORECAST TO PROVIDE A LITTLE BETTER TIMING OF THE
EXPECTED CONVECTION THIS AFTN. REST OF THE FCST APPEARS IN GOOD
SHAPE.
MORNING UA ANALYSIS DEPICTS A SEASONALLY STRONG SOMEWHAT
NEGATIVELY TILTED MID LVL SHORT WAVE ACRS ARKANSAS APPROACHING THE
AREA. THE REGION IS ALSO ENTERING THE RR QUAD OF A RELATIVELY
STRONG UPPER LVL JET STREAK WHICH WILL ENHANCE LIFT THIS
AFTERNOON. THERMODYNAMICS DON`T LOOK ALL THAT IMPRESSIVE RIGHT NOW
AS THE ATMOS IS PRETTY WORKED OVER AND A FAIR AMOUNT OF DEBRIS
CLOUD HAS HUNG ARND. MORNING SOUNDING DEPICTS A DEEP DRY/CAPPED
LOWER ATMOSPHERE THAT IS INHIBITING ANY DEVELOPMENT. DO EXPECT A
LITTLE MORE SUN TO DEVELOP...AND A SLOW INCRS IN LLVL MSTR IS
STILL ANTICIPATED. THE COMBINATION OF COOLING MID LVL TEMPS AND A
WARMING/MOISTENING LOWER ATMOS WILL ALLOW CONVECTION TO INITIATE
MOST LIKELY RIGHT ALONG A COLD FRONT PROGGED TO CROSS THE AREA IN
THE MID/LATE AFTN. DECENT SPEED SHEAR IN PLACE SO EXPECT ACTIVITY
TO ORIENT IN A LINE WITH DAMAGING STRAIGHT LINE WINDS POSSIBLE.
SPC CONTINUES A VERY LOW CHANCE OF A TORNADO AS WELL.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
JOHNSTONE
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
540 AM CDT WED MAY 22 2013
.UPDATE...
12Z TAF DISCUSSION.
&&
.AVIATION...
RADAR IMAGERY SHOWS MOST RECENT MCS HAS COLLAPSED WITH JUST A FEW
REMAINING -TSRA APPROACHING CSV. BY 12Z TAF ISSUANCE TIME...ALL
PRECIP SHOULD BE EAST OF AIRPORTS WITH DRY AND VFR CONDITIONS
EXPECTED THROUGH THE MORNING. LAMP GUIDANCE INDICATES GUSTY
SOUTHWEST WINDS TODAY WITH SPEEDS 5-12 KTS AND GUSTS TO 15-25
KTS. SHORTWAVE TROUGH ON WATER VAPOR IMAGERY OVER OKLAHOMA WILL
SWING ACROSS THE REGION LATER TODAY PRODUCING ANOTHER ROUND OF
SHOWERS AND STORMS IN THE AFTERNOON. DUE TO UNCERTAINTY ON
COVERAGE WILL ONLY MENTION VCTS AT CKV/BNA BUT TEMPO -TSRA AT
CSV. MUCH DRIER AIR ALOFT WILL FILTER IN BY 23/00Z WITH LESS
CLOUD COVER AND SOME PATCHY FOG POSSIBLE LATE IN TAF PERIOD.
55
&&
.PREV DISCUSSION... /ISSUED 246 AM CDT WED MAY 22 2013/
DISCUSSION...
CURRENT SETUP...UPPER TROUGH TAKING ON NEGATIVE TILT THROUGH THE MID-
LEVELS BASED ON LATEST RUC WITH THE COLDER AIR ALOFT REMAINING
BACK OVER CENTRAL PLAINS NOSING DOWN INTO ARKANSAS. A 35 TO 40
KNOT LOW LEVEL JET WAS CONTINUING TO FEED MOIST PLUME INTO MIDDLE
TENNESSEE. WIND FIELD LOOKS TO BE UNIDIRECTIONAL WITH SPEED SHEAR IN
THE LOWER TROPOSPHERE. UPPER LEVEL JET JUST RUNNING NORTH TO SOUTH
FROM ABOUT TEXARKANA NORTHWARD INTO IOWA WITH A 65 KNOT MID LEVEL
JET CUTTING ACROSS CENTRAL ARKANSAS. ON-GOING CONVECTION CURRENTLY
ACROSS FAR WESTERN KENTUCKY...WESTERN TENNESSEE AND DOWN THROUGH
MISSISSIPPI...BEEN SHOWING SIGNS OF WEAKENING LAST COUPLE OF HOURS
AS CLOUD TOPS CONTINUE TO WARM.
WITH THE CURRENT SETUP LOOKS LIKE SHOWERS AND STORMS WILL BE
LIKELY DURING THE DAY...WITH A FEW STRONG TO SEVERE STORMS
POSSIBLE...ESPECIALLY MID-DAY THROUGH THE AFTERNOON AND INTO THE
EARLY EVENING HOURS. THINK THE MAIN THREAT WILL BE DAMAGING WINDS AND
LARGE HAIL BUT ISOLATED TORNADOES ARE ALSO POSSIBLE. EVEN THOUGH
THE WIND FIELDS ARE UNIDIRECTIONAL THE SWEAT INDEX CLIMBS TO 362
AT 18Z AND 413 BY 00Z WITH MID-LEVEL DRYING IN PLACE DURING THE
MID-DAY THROUGH THE AFTERNOON/EARLY EVENING.
ON THURSDAY A SHORT WAVE ON THE BACK SIDE OF UPPER TROUGH WILL
DROP DOWN THROUGH THE OHIO VALLEY AND BRING A CHANCE FOR SHOWERS
AND ISOLATED THUNDERSTORMS MAINLY TO THE NORTHEAST HALF DURING THE
AFTERNOON WITH A SLIGHT CHANCE REMAINING ALONG THE PLATEAU
THURSDAY NIGHT. MUCH OF THE MEMORIAL DAY WEEKEND LOOKS DRY HOWEVER
MODELS HAVE BEEN DIFFERING. GFS HAS WARM FRONT DRAPED ACROSS THE
OHIO VALLEY THROUGH THE WEEKEND WHICH WOULD KEEP MID STATE
BASICALLY WARM AND DRY. THE EURO HAS WARM FRONT DRAPED THROUGH
WESTERN TENNESSEE INTO NORTHERN ALABAMA AND KEEPS SHOWERS AND
STORMS IN THE MID STATE JUST ABOUT EACH DAY THROUGH THE MEMORIAL
DAY WEEKEND. HAVE OPTED TO GO WITH GFS FOR THIS FORECAST PACKAGE.
HAVE BACKED OFF A TAD FROM MAV MOS ON HIGHS TODAY AND WENT CLOSER
TO THE MET DUE TO CLOUD COVER AND SHOWER/STORM CHANCES. STAYED
CLOSE TO MOS GUIDANCE THROUGH REMAINDER OF FORECAST.
BOYD
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
246 AM CDT WED MAY 22 2013
.DISCUSSION...
CURRENT SETUP...UPPER TROUGH TAKING ON NEGATIVE TILT THROUGH THE MID-
LEVELS BASED ON LATEST RUC WITH THE COLDER AIR ALOFT REMAINING
BACK OVER CENTRAL PLAINS NOSING DOWN INTO ARKANSAS. A 35 TO 40
KNOT LOW LEVEL JET WAS CONTINUING TO FEED MOIST PLUME INTO MIDDLE
TENNESSEE. WIND FIELD LOOKS TO BE UNIDIRECTIONAL WITH SPEED SHEAR IN
THE LOWER TROPOSPHERE. UPPER LEVEL JET JUST RUNNING NORTH TO SOUTH
FROM ABOUT TEXARKANA NORTHWARD INTO IOWA WITH A 65 KNOT MID LEVEL
JET CUTTING ACROSS CENTRAL ARKANSAS. ON-GOING CONVECTION CURRENTLY
ACROSS FAR WESTERN KENTUCKY...WESTERN TENNESSEE AND DOWN THROUGH
MISSISSIPPI...BEEN SHOWING SIGNS OF WEAKENING LAST COUPLE OF HOURS
AS CLOUD TOPS CONTINUE TO WARM.
WITH THE CURRENT SETUP LOOKS LIKE SHOWERS AND STORMS WILL BE
LIKELY DURING THE DAY...WITH A FEW STRONG TO SEVERE STORMS
POSSIBLE...ESPECIALLY MID-DAY THROUGH THE AFTERNOON AND INTO THE
EARLY EVENING HOURS. THINK THE MAIN THREAT WILL BE DAMAGING WINDS AND
LARGE HAIL BUT ISOLATED TORNADOES ARE ALSO POSSIBLE. EVEN THOUGH
THE WIND FIELDS ARE UNIDIRECTIONAL THE SWEAT INDEX CLIMBS TO 362
AT 18Z AND 413 BY 00Z WITH MID-LEVEL DRYING IN PLACE DURING THE
MID-DAY THROUGH THE AFTERNOON/EARLY EVENING.
ON THURSDAY A SHORT WAVE ON THE BACK SIDE OF UPPER TROUGH WILL
DROP DOWN THROUGH THE OHIO VALLEY AND BRING A CHANCE FOR SHOWERS
AND ISOLATED THUNDERSTORMS MAINLY TO THE NORTHEAST HALF DURING THE
AFTERNOON WITH A SLIGHT CHANCE REMAINING ALONG THE PLATEAU
THURSDAY NIGHT. MUCH OF THE MEMORIAL DAY WEEKEND LOOKS DRY HOWEVER
MODELS HAVE BEEN DIFFERING. GFS HAS WARM FRONT DRAPED ACROSS THE
OHIO VALLEY THROUGH THE WEEKEND WHICH WOULD KEEP MID STATE
BASICALLY WARM AND DRY. THE EURO HAS WARM FRONT DRAPED THROUGH
WESTERN TENNESSEE INTO NORTHERN ALABAMA AND KEEPS SHOWERS AND
STORMS IN THE MID STATE JUST ABOUT EACH DAY THROUGH THE MEMORIAL
DAY WEEKEND. HAVE OPTED TO GO WITH GFS FOR THIS FORECAST PACKAGE.
HAVE BACKED OFF A TAD FROM MAV MOS ON HIGHS TODAY AND WENT CLOSER
TO THE MET DUE TO CLOUD COVER AND SHOWER/STORM CHANCES. STAYED
CLOSE TO MOS GUIDANCE THROUGH REMAINDER OF FORECAST.
BOYD
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 79 61 78 52 / 60 30 20 10
CLARKSVILLE 76 58 76 49 / 60 20 20 10
CROSSVILLE 76 59 73 51 / 70 50 30 20
COLUMBIA 79 61 80 54 / 60 30 20 10
LAWRENCEBURG 78 60 80 55 / 60 30 20 10
WAVERLY 77 59 77 50 / 60 20 20 10
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
BOYD
01
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1242 AM CDT WED MAY 22 2013
.DISCUSSION...SEE AVIATION SECTION FOR 06Z TAFS.
&&
.AVIATION...LOOP OF KCRP RADAR SHOWS OUTFLOW BOUNDARY/FRONT MOVING
SOUTH AT 20 MPH INTO THE VICTORIA CROSSROADS REGION. LOW STRATUS HAS
MOVED INTO THE COASTAL PLAINS WITH CEILINGS RANGING FROM IFR IN THE
COASTAL BEND TO LOW END MVFR IN THE VICTORIA CROSSROADS. EXPECT THE
BOUNDARY WILL STALL BEFORE MOVING INTO THE COASTAL WATERS OR COASTAL
BEND LATER DURING THE OVERNIGHT. EAST-SOUTHEASTERLY LOW LEVEL FLOW
WILL PUSH LOW CLOUDS WESTWARD INTO THE BRUSH COUNTRY REACHING LRD
AREA BY 09Z. ONLY PLACED A MENTION OF LIGHT SHOWERS IN THE VCT TAF
BEHIND THE FRONT EARLY THIS MORNING. MVFR CEILINGS WILL SLOWLY LIFT
DURING THE MORNING HOURS AND SCATTER OUT BY 18Z AREA-WIDE. VFR CONDS
WILL EXIST INTO THE EVENING HOURS WEDNESDAY WITH MVFR CIGS RETURNING
TO THE COASTAL PLAINS BY 02-03Z THURSDAY.
&&
.PREV DISCUSSION... /ISSUED 906 PM CDT TUE MAY 21 2013/
DISCUSSION...CONVECTION HAS FAILED TO DEVELOP AS OF WRITING AS SSW
FLOW FROM H95 TO H7, PER 00Z AREA RAOBS, IS LIKELY NEGATING CONVECTIVE
DEVELOPMENT. LATEST AVAILABLE HRRR AND 18Z TTU WRF ALSO INDICATE
ONLY LOW CHANCES OF PRECIP DEVELOPING TONIGHT. THUS...HAVE LOWERED
POPS FOR TONIGHT AREAWIDE. STILL THINK A THIN BAND OF SHOWERS AND
A FEW RUMBLES OF THUNDER WILL DEVELOP OVERNIGHT...PRIMARILY ACROSS
NORTHERN AND NE ZONES. WILL CONTINUE TO MONITOR SITUATION THROUGH
THE NIGHT. OTHERWISE...ONLY OTHER CHANGE OF SIGNIFICANCE WAS TO
INCLUDE MENTION OF HAZE AND SMOKE FARTHER INLAND TONIGHT AS SMOKE
FROM AGRICULTURAL FIRES OVER STATE OF YUCATAN MEX CONTINUES TO
IMPACT S TX. AIR PARTICULATES WILL LIKELY POOL ALONG STALLING WEAK
SFC FRONT ACROSS NORTHERN ZONES TONIGHT RESULTING IN A
CONTINUATION OF HAZE/SMOKINESS THROUGH WEDNESDAY. UPDATED PRODUCTS
TO BE SENT SHORTLY.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 75 92 75 91 76 / 10 10 10 10 10
VICTORIA 73 90 74 89 73 / 10 10 10 10 10
LAREDO 76 98 75 96 75 / 10 10 10 10 10
ALICE 73 93 75 91 75 / 10 10 10 10 10
ROCKPORT 75 86 75 85 76 / 10 10 10 10 10
COTULLA 73 98 74 96 74 / 10 10 10 10 10
KINGSVILLE 74 92 75 91 75 / 10 10 10 10 10
NAVY CORPUS 75 84 75 84 75 / 10 10 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
TMT/89...AVIATION
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
148 PM EDT WED MAY 22 2013
.SYNOPSIS...
A LARGE LOW PRESSURE SYSTEM WILL TRACK FROM THE CENTRAL PLAINS INTO
THE GREAT LAKES BY THURSDAY. THIS SYSTEM WILL PUSH A COLD FRONT
THROUGH THE AREA THURSDAY INTO THURSDAY EVENING... FOLLOWED BY HIGH
PRESSURE ON FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 135 PM EDT WEDNESDAY...
ADJUSTED POPS ACROSS TO LATEST RADAR TRENDS WITH CONVECTION
DEVELOPING OVER THE MOUNTAINS.
AS OF 925 AM EDT WEDNESDAY...
ADJUSTED POPS FOR LATEST RADAR TREND...SHAPING POPS THIS MORNING
INTO TOWARDS LATEST RNK WRFARW. KEPT THE BEST CHANCE FOR
THUNDERSTORMS THIS AFTERNOON IN THE WEST. SWODY1 HAS PLACED A
SLIGHT RISK JUST TO OUR WEST. MORNING RUN SHOWED THE POTENTIAL
FOR LINE OF CONVECTION REACHING THE WEST BETWEEN 00Z AND 06Z
TONIGHT. WILL REVIEW 12Z RUN BEFORE MAKING ANY MAJOR ADJUSTMENTS
FOR TONIGHT. MODIFIED TEMPERATURES AND DEW POINTS THIS MORNING
INTO THIS AFTERNOON. RAISED HIGH TEMPERATURES UP A FEW DEGREES IN
SOUTHEAST. UPDATED FIRE WEATHER GRIDS...FWFRNK OUT. ADDITIONAL
CHANGES LATER TODAY.
AS OF 340 AM EDT WEDNESDAY...
A COUPLE OF CONCERNS TODAY. THE MAIN CONCERN IS WITH THE POTENTIAL
FOR ISOLATED HEAVY RAIN IN THUNDERSTORMS THIS AFTERNOON. THE LOWEST
FLASH FLOOD GUIDANCE IS CURRENTLY OBSERVED IN AREAS THAT HAVE
RECEIVED HEAVY RAIN RECENTLY AND MOSTLY IN THE MOUNTAINS INCLUDING
WATAUGA... ASHE... GRAYSON... INTO SMYTH AND TAZEWELL OF VA.
HOWEVER... GIVEN THE EXPECTED SCATTERED NATURE OF THE CONVECTION
THIS AFTERNOON... IT APPEARS THAT THE FLOODING THREAT WILL BE
ISOLATED. THEREFORE... OPTED OUT OF A FLASH FLOOD WATCH AT THE
CURRENT TIME. THE LATEST HI-RES MODELS INCLUDING THE HRRR INDICATE
AT LEAST SCATTERED THUNDERSTORMS WILL DEVELOP OVER OUR REGION THIS
AFTERNOON... PRIMARILY OVER THE MOUNTAINS AND FOOTHILLS SPREADING
NE INTO THE VA PIEDMONT LATE THIS AFTERNOON AS WELL. WE WILL
CONTINUE THE CHANCE CATEGORY POP FOR THOSE ZONES THIS AFTERNOON.
EVEN MORE PROBLEMATIC MAY BE THE POSSIBLE LINE OF CONVECTION THAT
THE HI-RES MODELS AND EVEN A FEW OF THE OPERATIONAL MODELS ARE
PICKING UP ON ACROSS KY/TN THIS AFTERNOON. SOME OF THESE MODELS
INDICATE A POTENTIAL MCS THAT MAY HOLD TOGETHER LONG ENOUGH TO SURGE
INTO FAR SW VA... SOUTHERN WVA... AND POSSIBLY NORTHWEST NC BETWEEN
00Z AND 06Z TONIGHT. IT IS UNCLEAR HOW STRONG OR HOW FAST THIS
CONVECTION WOULD BE AT THE CURRENT TIME. IF THIS APPEARS MORE LIKELY
IN THE MODEL RUNS TODAY... THERE MAY BE A CONCERN WITH FLASH
FLOODING THIS EVENING. WE WILL GO WITH HIGH CHANCE TO LOW END LIKELY
THIS EVENING TO COVER THIS POTENTIAL.
THE SLIGHT RISK FOR SEVERE CONVECTION CONTINUES TO BE JUST WEST OF
OUR REGION TODAY INTO TONIGHT.
CONDITIONS TODAY WILL BE WARM AND HUMID WITH THE SOUTHERLY FLOW OUT
AHEAD OF THE APPROACHING COLD FRONT AND UPPER TROUGH. HIGHS
TEMPERATURES SHOULD REACH THE MID 70S IN THE MOUNTAINS TO THE MID
80S IN THE SOUTHEAST. LOWS TONIGHT WILL DIP BACK INTO THE 50S TO MID
60S SE.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AS OF 320 AM EDT WEDNESDAY...
A LEAD SURFACE TROUGH OR CONVECTIVE OUTFLOW MAY AFFECT THE REGION
BEFORE THE ACTUAL COLD FRONT ARRIVES THURSDAY. THIS MAY AFFECT THE
CONVECTIVE CHANCES GREATLY AS THE MAIN COLD FRONT ARRIVES THURSDAY.
OTHERWISE... A PERIOD OF LIKELY POP CAN BE EXPECTED WITH THE FRONT
THURSDAY... POSSIBLY LASTING INTO THE EARLY EVENING AROUND DANVILLE.
LACK OF HEATING THURSDAY... ESPECIALLY WEST OF THE BLUE RIDGE MAY
ALSO LIMIT DESTABILIZATION. THE AREA WITH THE BETTER INSOLATION
COULD BE SOUTHSIDE VA/NW NC PIEDMONT. AT THIS TIME...THE STORM
PREDICTION CENTER HAS A 5 PERCENT THREAT OF SVR WX MAINLY OVER THE
PIEDMONT AND TIDEWATER AREAS OF VA/NC.
THE FRONT WILL BE EAST OF THE AREA GOING INTO THURSDAY EVENING WITH
LINGERING SHORTWAVE INDUCED SHOWERS ACROSS THE MTNS OVERNIGHT. THE
MAIN SHORTWAVE SHIFTS EAST BY 12Z FRIDAY WITH DRIER AND COOLER AIR
ARRIVING. HIGHS FRIDAY WILL RANGE FROM THE LOWER TO MID 60S WEST TO
THE LOWER TO MID 70S EAST.
FRIDAY NIGHT AND SATURDAY:
QUITE WEATHER IS EXPECTED TO RETURN FOR THE REST OF THE SHORT TERM
FORECAST... WITH THE MID LEVEL TROUGH AXIS HAVING PUSHED TO THE EAST
OF THE AREA BY FRIDAY EVENING AND HIGH PRESSURE AT THE SURFACE
BUILDING INTO THE REGION FOR THIS TIME FRAME. THIS WILL YIELD
GENERALLY COOL AND DRY CONDITIONS... WITH BELOW NORMAL TEMPS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 130 PM EDT TUESDAY
FOR THE LONG RANGE FORECAST...THE MODELS KEEP A TROUGH IN PLACE
EARLY ON AND THEN GO MORE TOWARD A ZONAL TO RIDGE CONFIGURATION BY
THE END OF THE PERIOD.
WE SHOULD BE MAINLY DRY AS SFC HIGH BUILDS ACROSS THIS WEEKEND...SO
WEEKEND HOLIDAY PLANS ARE LOOKING GOOD FOR OUTDOOR ACTIVITIES AT
LEAST SATURDAY...AS THE LATEST ECMWF SHOWS ANOTHER WEAK SHORTWAVE
PUSHING ACROSS BY SUNDAY AND MAY BRING SOME SHOWERS ACROSS THE MTN
EMPIRE OF SW VA/INTO THE NC MTNS SUNDAY MORNING.
THE FLOW SWINGS MORE TOWARD THE SOUTHEAST SUNDAY EVENING INTO EARLY
NEXT WEEK WITH INCREASING HUMIDITY AND TEMPS. MODELS KEEPING MORE
ACTIVE WEATHER ACROSS THE OHIO VALLEY AND WEST...ALTHOUGH A WESTERLY
FLOW ALOFT CAN BRING STORMS WORKING EAST INTO THE MTNS. GIVEN WPC
SOLUTION OF THE ECMWF ENSEMBLE WILL KEEP THE FORECAST MORE ON THE
LOW CHANCE SIDE...BUT IF THE 12Z ECMWF VERIFIES WE COULD BE GETTING
SOAKED AGAIN MONDAY-WEDNESDAY.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 140 PM EDT WEDNESDAY...
SCATTERED MVFR/IFR CONVECTION DEVELOPING IN THE WARM UNSTABLE AIR
ACROSS CWA THIS AFTERNOON. THE BEST CHANCE OF THUNDERSTORMS WILL
OCCUR ACROSS WESTERN TAF SITES OF BLF/LWB/RNK. RNKWRF ARW SHOWED
GOOD COVERAGE OF STORM ACROSS THE MOUNTAINS THIS AFTERNOON INTO
TONIGHT. ECMWF/GFS GENERALLY CONSISTENT ON A LINE OF STRONG
THUNDERSTORMS MOVING INTO FAR SW VA FROM KY/TN IN THE 00Z-04Z TIME
FRAME...THEN GENERALLY DISSIPATING AS MOVE EAST. FOR THE EAST...
THERE IS POTENTIAL TSRA DEVELOPMENT ACROSS THE NC
PIEDMONT...LIFTING NORTHWARD TOWARD LYH/DAN/EVEN ROA BY LATE
AFTERNOON INTO THIS EVENING.
S-SW WINDS 5-10KTS THROUGH TAF VALID PERIOD...WITH LOW END GUSTS
ACROSS THE PIEDMONT. AREAS OF FOG WILL DEVELOP TONIGHT INTO
WEDNESDAY MORNING WHERE RAIN FALLS THIS AFTERNOON INTO THIS
EVENING.
MEDIUM TO HIGH CONFIDENCE IN CIGS/VSBYS THROUGH TAF VALID PERIOD.
HIGH CONFIDENCE IN WIND SPD/DIR THROUGH TAF VALID PERIOD.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/JH/KK
SHORT TERM...WP
LONG TERM...WP
AVIATION...KK/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
940 AM EDT WED MAY 22 2013
.SYNOPSIS...
A LARGE LOW PRESSURE SYSTEM WILL TRACK FROM THE CENTRAL PLAINS INTO
THE GREAT LAKES BY THURSDAY. THIS SYSTEM WILL PUSH A COLD FRONT
THROUGH THE AREA THURSDAY INTO THURSDAY EVENING... FOLLOWED BY HIGH
PRESSURE ON FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 925 AM EDT WEDNESDAY...
ADJUSTED POPS FOR LATEST RADAR TREND...SHAPING POPS THIS MORNING
INTO TOWARDS LATEST RNK WRFARW. KEPT THE BEST CHANCE FOR
THUNDERSTORMS THIS AFTERNOON IN THE WEST. SWODY1 HAS PLACED A
SLIGHT RISK JUST TO OUR WEST. MORNING RUN SHOWED THE POTENTIAL
FOR LINE OF CONVECTION REACHING THE WEST BETWEEN 00Z AND 06Z
TONIGHT. WILL REVIEW 12Z RUN BEFORE MAKING ANY MAJOR ADJUSTMENTS
FOR TONIGHT. MODIFIED TEMPERATURES AND DEW POINTS THIS MORNING
INTO THIS AFTERNOON. RAISED HIGH TEMPERATURES UP A FEW DEGREES IN
SOUTHEAST. UPDATED FIRE WEATHER GRIDS...FWFRNK OUT. ADDITIONAL
CHANGES LATER TODAY.
AS OF 340 AM EDT WEDNESDAY...
A COUPLE OF CONCERNS TODAY. THE MAIN CONCERN IS WITH THE POTENTIAL
FOR ISOLATED HEAVY RAIN IN THUNDERSTORMS THIS AFTERNOON. THE LOWEST
FLASH FLOOD GUIDANCE IS CURRENTLY OBSERVED IN AREAS THAT HAVE
RECEIVED HEAVY RAIN RECENTLY AND MOSTLY IN THE MOUNTAINS INCLUDING
WATAUGA... ASHE... GRAYSON... INTO SMYTH AND TAZEWELL OF VA.
HOWEVER... GIVEN THE EXPECTED SCATTERED NATURE OF THE CONVECTION
THIS AFTERNOON... IT APPEARS THAT THE FLOODING THREAT WILL BE
ISOLATED. THEREFORE... OPTED OUT OF A FLASH FLOOD WATCH AT THE
CURRENT TIME. THE LATEST HI-RES MODELS INCLUDING THE HRRR INDICATE
AT LEAST SCATTERED THUNDERSTORMS WILL DEVELOP OVER OUR REGION THIS
AFTERNOON... PRIMARILY OVER THE MOUNTAINS AND FOOTHILLS SPREADING
NE INTO THE VA PIEDMONT LATE THIS AFTERNOON AS WELL. WE WILL
CONTINUE THE CHANCE CATEGORY POP FOR THOSE ZONES THIS AFTERNOON.
EVEN MORE PROBLEMATIC MAY BE THE POSSIBLE LINE OF CONVECTION THAT
THE HI-RES MODELS AND EVEN A FEW OF THE OPERATIONAL MODELS ARE
PICKING UP ON ACROSS KY/TN THIS AFTERNOON. SOME OF THESE MODELS
INDICATE A POTENTIAL MCS THAT MAY HOLD TOGETHER LONG ENOUGH TO SURGE
INTO FAR SW VA... SOUTHERN WVA... AND POSSIBLY NORTHWEST NC BETWEEN
00Z AND 06Z TONIGHT. IT IS UNCLEAR HOW STRONG OR HOW FAST THIS
CONVECTION WOULD BE AT THE CURRENT TIME. IF THIS APPEARS MORE LIKELY
IN THE MODEL RUNS TODAY... THERE MAY BE A CONCERN WITH FLASH
FLOODING THIS EVENING. WE WILL GO WITH HIGH CHANCE TO LOW END LIKELY
THIS EVENING TO COVER THIS POTENTIAL.
THE SLIGHT RISK FOR SEVERE CONVECTION CONTINUES TO BE JUST WEST OF
OUR REGION TODAY INTO TONIGHT.
CONDITIONS TODAY WILL BE WARM AND HUMID WITH THE SOUTHERLY FLOW OUT
AHEAD OF THE APPROACHING COLD FRONT AND UPPER TROUGH. HIGHS
TEMPERATURES SHOULD REACH THE MID 70S IN THE MOUNTAINS TO THE MID
80S IN THE SOUTHEAST. LOWS TONIGHT WILL DIP BACK INTO THE 50S TO MID
60S SE.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AS OF 320 AM EDT WEDNESDAY...
A LEAD SURFACE TROUGH OR CONVECTIVE OUTFLOW MAY AFFECT THE REGION
BEFORE THE ACTUAL COLD FRONT ARRIVES THURSDAY. THIS MAY AFFECT THE
CONVECTIVE CHANCES GREATLY AS THE MAIN COLD FRONT ARRIVES THURSDAY.
OTHERWISE... A PERIOD OF LIKELY POP CAN BE EXPECTED WITH THE FRONT
THURSDAY... POSSIBLY LASTING INTO THE EARLY EVENING AROUND DANVILLE.
LACK OF HEATING THURSDAY... ESPECIALLY WEST OF THE BLUE RIDGE MAY
ALSO LIMIT DESTABILIZATION. THE AREA WITH THE BETTER INSOLATION
COULD BE SOUTHSIDE VA/NW NC PIEDMONT. AT THIS TIME...THE STORM
PREDICTION CENTER HAS A 5 PERCENT THREAT OF SVR WX MAINLY OVER THE
PIEDMONT AND TIDEWATER AREAS OF VA/NC.
THE FRONT WILL BE EAST OF THE AREA GOING INTO THURSDAY EVENING WITH
LINGERING SHORTWAVE INDUCED SHOWERS ACROSS THE MTNS OVERNIGHT. THE
MAIN SHORTWAVE SHIFTS EAST BY 12Z FRIDAY WITH DRIER AND COOLER AIR
ARRIVING. HIGHS FRIDAY WILL RANGE FROM THE LOWER TO MID 60S WEST TO
THE LOWER TO MID 70S EAST.
FRIDAY NIGHT AND SATURDAY:
QUITE WEATHER IS EXPECTED TO RETURN FOR THE REST OF THE SHORT TERM
FORECAST... WITH THE MID LEVEL TROUGH AXIS HAVING PUSHED TO THE EAST
OF THE AREA BY FRIDAY EVENING AND HIGH PRESSURE AT THE SURFACE
BUILDING INTO THE REGION FOR THIS TIME FRAME. THIS WILL YIELD
GENERALLY COOL AND DRY CONDITIONS... WITH BELOW NORMAL TEMPS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 130 PM EDT TUESDAY
FOR THE LONG RANGE FORECAST...THE MODELS KEEP A TROUGH IN PLACE
EARLY ON AND THEN GO MORE TOWARD A ZONAL TO RIDGE CONFIGURATION BY
THE END OF THE PERIOD.
WE SHOULD BE MAINLY DRY AS SFC HIGH BUILDS ACROSS THIS WEEKEND...SO
WEEKEND HOLIDAY PLANS ARE LOOKING GOOD FOR OUTDOOR ACTIVITIES AT
LEAST SATURDAY...AS THE LATEST ECMWF SHOWS ANOTHER WEAK SHORTWAVE
PUSHING ACROSS BY SUNDAY AND MAY BRING SOME SHOWERS ACROSS THE MTN
EMPIRE OF SW VA/INTO THE NC MTNS SUNDAY MORNING.
THE FLOW SWINGS MORE TOWARD THE SOUTHEAST SUNDAY EVENING INTO EARLY
NEXT WEEK WITH INCREASING HUMIDITY AND TEMPS. MODELS KEEPING MORE
ACTIVE WEATHER ACROSS THE OHIO VALLEY AND WEST...ALTHOUGH A WESTERLY
FLOW ALOFT CAN BRING STORMS WORKING EAST INTO THE MTNS. GIVEN WPC
SOLUTION OF THE ECMWF ENSEMBLE WILL KEEP THE FORECAST MORE ON THE
LOW CHANCE SIDE...BUT IF THE 12Z ECMWF VERIFIES WE COULD BE GETTING
SOAKED AGAIN MONDAY-WEDNESDAY.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
AS OF 745 AM EDT WEDNESDAY...
PATCHY FOG WILL DISSIPATE QUICKLY...ALTHOUGH IFR CIGS MAY LINGER
ACROSS THE PIEDMONT FROM DAN-LYH FOR A WHILE THIS MORNING.
OTHERWISE...MOSTLY VFR AFT 14Z WITH SC/CU DEVELOPING FROM EARLY
MORNING MOISTURE. MAIN CONCERN WILL COME LATE TODAY AS THE STRONG
COLD FRONT RESPONSIBLE FOR ALL OF THE SEVERE WEATHER IN THE
MIDWEST RECENTLY APPROACHES THE AREA FROM THE WEST. ECMWF/GFS
GENERALLY CONSISTENT ON A LINE OF STRONG THUNDERSTORMS MOVING
INTO FAR SW VA FROM KY/TN IN THE 00Z-04Z TIME FRAME...THEN
GENERALLY DISSIPATING AS IT MOVES TOWARD THE NEW RIVER VALLEY
REGION...SIMILAR TIMING TO WHAT WE SAW YESTERDAY...BUT EXPECT
ACTIVITY TO BE A LITTLE MORE POTENT THIS EVENING. DO NOT EXPECT
THIS ACTIVITY TO SURVIVE AS IT REACHES THE PIEDMONT.
HOWEVER...MODELS SHOW...ESPECIALLY THE GFS...POTENTIAL TSRA
DEVELOPMENT ACROSS THE NC PIEDMONT...LIFTING NORTHWARD TOWARD
LYH/DAN/EVEN ROA BY LATE AFTERNOON. HAVE PLAYED SOME POTENTIAL FOR
THIS INTO THE TAFS. OTHERWISE...MOSTLY MVFR CIGS AND MVFR VSBYS IN
VCTS AND/OR TSRA MOSTLY AFT 00Z...AGAIN LITTLE OF WHICH SHOULD
REACH THE PIEDMONT. S-SW WINDS 5-10KTS THROUGH TAF VALID
PERIOD...WITH LOW END GUSTS ACROSS THE PIEDMONT.
MEDIUM TO HIGH CONFIDENCE IN CIGS/VSBYS THROUGH TAF VALID PERIOD.
HIGH CONFIDENCE IN WIND SPD/DIR THROUGH TAF VALID PERIOD.
AS OF 202 AM EDT WEDNESDAY...
THE MAIN CONCERN THIS MORNING APPEARS TO BE FOG AROUND AREAS THAT
HAD HEAVY RAINFALL RECENTLY. LATEST DATA SUGGESTS PATCHY FOG WITH
SOME AREAS OF LOCALLY DENSE FOG. IFR TO LIFR FOG WILL BE POSSIBLE.
THE EARLIER SHOWERS HAVE DISSIPATED. ONLY ISOLATED LIGHT RAIN
SHOWERS ARE EXPECTED THIS MORNING.
A QUICK IMPROVEMENT TO CONDITIONS WEDNESDAY MORNING WITH THE ONSET
OF HEATING AND DECENT MIXING BY MID OR LATE MORNING. THINK ALL SITES
WILL BE VFR BY 15Z/11AM BUT WITH A BETTER SHOT AT AFTERNOON
CONVECTION DEVELOPING ESPCLY WEST OF THE BLUE RIDGE BY 20Z/4PM. WITH
POTENTIAL TO SEE A BAND OF SHRA/TSRA DEVELOP WESTERN
SLOPES...INCLUDED A PREVAILING -TSRA THREAT AT BOTH KBLF/KLWB
WEDNESDAY AFTERNOON WHILE LEAVING ELSW VFR W/OUT CONVECTION UNDER
SCTD/BKN 5-6K FT CU FIELDS.
THE REGION STAYS IN A WARM...MOIST AIRMASS THROUGH THURSDAY AHEAD
OF A COLD FRONT THAT SHOULD PUSH THROUGH LATE IN THE DAY THURSDAY.
THIS WILL BRING THE BEST COVERAGE OF SHOWERS WEDNESDAY NIGHT INTO
THURSDAY ALONG WITH AREAS OF LATE NIGHT/EARLY MORNING FOG.
HIGH PRESSURE AND BETTER FLYING CONDITIONS ARE EXPECTED ON FRIDAY
AND THROUGH MUCH OF THE WEEKEND BEHIND THE FRONT.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/RAB
NEAR TERM...AMS/JH/KK
SHORT TERM...WP
LONG TERM...WP
AVIATION...RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
750 AM EDT WED MAY 22 2013
.SYNOPSIS...
A LARGE LOW PRESSURE SYSTEM WILL TRACK FROM THE CENTRAL PLAINS INTO
THE GREAT LAKES BY THURSDAY. THIS SYSTEM WILL PUSH A COLD FRONT
THROUGH THE AREA THURSDAY INTO THURSDAY EVENING... FOLLOWED BY HIGH
PRESSURE ON FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 340 AM EDT WEDNESDAY...
A COUPLE OF CONCERNS TODAY. THE MAIN CONCERN IS WITH THE POTENTIAL
FOR ISOLATED HEAVY RAIN IN THUNDERSTORMS THIS AFTERNOON. THE LOWEST
FLASH FLOOD GUIDANCE IS CURRENTLY OBSERVED IN AREAS THAT HAVE
RECEIVED HEAVY RAIN RECENTLY AND MOSTLY IN THE MOUNTAINS INCLUDING
WATAUGA... ASHE... GRAYSON... INTO SMYTH AND TAZEWELL OF VA.
HOWEVER... GIVEN THE EXPECTED SCATTERED NATURE OF THE CONVECTION
THIS AFTERNOON... IT APPEARS THAT THE FLOODING THREAT WILL BE
ISOLATED. THEREFORE... OPTED OUT OF A FLASH FLOOD WATCH AT THE
CURRENT TIME. THE LATEST HI-RES MODELS INCLUDING THE HRRR INDICATE
AT LEAST SCATTERED THUNDERSTORMS WILL DEVELOP OVER OUR REGION THIS
AFTERNOON... PRIMARILY OVER THE MOUNTAINS AND FOOTHILLS SPREADING
NE INTO THE VA PIEDMONT LATE THIS AFTERNOON AS WELL. WE WILL
CONTINUE THE CHANCE CATEGORY POP FOR THOSE ZONES THIS AFTERNOON.
EVEN MORE PROBLEMATIC MAY BE THE POSSIBLE LINE OF CONVECTION THAT
THE HI-RES MODELS AND EVEN A FEW OF THE OPERATIONAL MODELS ARE
PICKING UP ON ACROSS KY/TN THIS AFTERNOON. SOME OF THESE MODELS
INDICATE A POTENTIAL MCS THAT MAY HOLD TOGETHER LONG ENOUGH TO SURGE
INTO FAR SW VA... SOUTHERN WVA... AND POSSIBLY NORTHWEST NC BETWEEN
00Z AND 06Z TONIGHT. IT IS UNCLEAR HOW STRONG OR HOW FAST THIS
CONVECTION WOULD BE AT THE CURRENT TIME. IF THIS APPEARS MORE LIKELY
IN THE MODEL RUNS TODAY... THERE MAY BE A CONCERN WITH FLASH
FLOODING THIS EVENING. WE WILL GO WITH HIGH CHANCE TO LOW END LIKELY
THIS EVENING TO COVER THIS POTENTIAL.
THE SLIGHT RISK FOR SEVERE CONVECTION CONTINUES TO BE JUST WEST OF
OUR REGION TODAY INTO TONIGHT.
CONDITIONS TODAY WILL BE WARM AND HUMID WITH THE SOUTHERLY FLOW OUT
AHEAD OF THE APPROACHING COLD FRONT AND UPPER TROUGH. HIGHS
TEMPERATURES SHOULD REACH THE MID 70S IN THE MOUNTAINS TO THE MID
80S IN THE SOUTHEAST. LOWS TONIGHT WILL DIP BACK INTO THE 50S TO MID
60S SE.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AS OF 320 AM EDT WEDNESDAY...
A LEAD SURFACE TROUGH OR CONVECTIVE OUTFLOW MAY AFFECT THE REGION
BEFORE THE ACTUAL COLD FRONT ARRIVES THURSDAY. THIS MAY AFFECT THE
CONVECTIVE CHANCES GREATLY AS THE MAIN COLD FRONT ARRIVES THURSDAY.
OTHERWISE... A PERIOD OF LIKELY POP CAN BE EXPECTED WITH THE FRONT
THURSDAY... POSSIBLY LASTING INTO THE EARLY EVENING AROUND DANVILLE.
LACK OF HEATING THURSDAY... ESPECIALLY WEST OF THE BLUE RIDGE MAY
ALSO LIMIT DESTABILIZATION. THE AREA WITH THE BETTER INSOLATION
COULD BE SOUTHSIDE VA/NW NC PIEDMONT. AT THIS TIME...THE STORM
PREDICTION CENTER HAS A 5 PERCENT THREAT OF SVR WX MAINLY OVER THE
PIEDMONT AND TIDEWATER AREAS OF VA/NC.
THE FRONT WILL BE EAST OF THE AREA GOING INTO THURSDAY EVENING WITH
LINGERING SHORTWAVE INDUCED SHOWERS ACROSS THE MTNS OVERNIGHT. THE
MAIN SHORTWAVE SHIFTS EAST BY 12Z FRIDAY WITH DRIER AND COOLER AIR
ARRIVING. HIGHS FRIDAY WILL RANGE FROM THE LOWER TO MID 60S WEST TO
THE LOWER TO MID 70S EAST.
FRIDAY NIGHT AND SATURDAY:
QUITE WEATHER IS EXPECTED TO RETURN FOR THE REST OF THE SHORT TERM
FORECAST... WITH THE MID LEVEL TROUGH AXIS HAVING PUSHED TO THE EAST
OF THE AREA BY FRIDAY EVENING AND HIGH PRESSURE AT THE SURFACE
BUILDING INTO THE REGION FOR THIS TIME FRAME. THIS WILL YIELD
GENERALLY COOL AND DRY CONDITIONS... WITH BELOW NORMAL TEMPS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 130 PM EDT TUESDAY
FOR THE LONG RANGE FORECAST...THE MODELS KEEP A TROUGH IN PLACE
EARLY ON AND THEN GO MORE TOWARD A ZONAL TO RIDGE CONFIGURATION BY
THE END OF THE PERIOD.
WE SHOULD BE MAINLY DRY AS SFC HIGH BUILDS ACROSS THIS WEEKEND...SO
WEEKEND HOLIDAY PLANS ARE LOOKING GOOD FOR OUTDOOR ACTIVITIES AT
LEAST SATURDAY...AS THE LATEST ECMWF SHOWS ANOTHER WEAK SHORTWAVE
PUSHING ACROSS BY SUNDAY AND MAY BRING SOME SHOWERS ACROSS THE MTN
EMPIRE OF SW VA/INTO THE NC MTNS SUNDAY MORNING.
THE FLOW SWINGS MORE TOWARD THE SOUTHEAST SUNDAY EVENING INTO EARLY
NEXT WEEK WITH INCREASING HUMIDITY AND TEMPS. MODELS KEEPING MORE
ACTIVE WEATHER ACROSS THE OHIO VALLEY AND WEST...ALTHOUGH A WESTERLY
FLOW ALOFT CAN BRING STORMS WORKING EAST INTO THE MTNS. GIVEN WPC
SOLUTION OF THE ECMWF ENSEMBLE WILL KEEP THE FORECAST MORE ON THE
LOW CHANCE SIDE...BUT IF THE 12Z ECMWF VERIFIES WE COULD BE GETTING
SOAKED AGAIN MONDAY-WEDNESDAY.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 745 AM EDT WEDNESDAY...
PATCHY FOG WILL DISSIPATE QUICKLY...ALTHOUGH IFR CIGS MAY LINGER
ACROSS THE PIEDMONT FROM DAN-LYH FOR A WHILE THIS MORNING.
OTHERWISE...MOSTLY VFR AFT 14Z WITH SC/CU DEVELOPING FROM EARLY
MORNING MOISTURE. MAIN CONCERN WILL COME LATE TODAY AS THE STRONG
COLD FRONT RESPONSIBLE FOR ALL OF THE SEVERE WEATHER IN THE
MIDWEST RECENTLY APPROACHES THE AREA FROM THE WEST. ECMWF/GFS
GENERALLY CONSISTENT ON A LINE OF STRONG THUNDERSTORMS MOVING
INTO FAR SW VA FROM KY/TN IN THE 00Z-04Z TIME FRAME...THEN
GENERALLY DISSIPATING AS IT MOVES TOWARD THE NEW RIVER VALLEY
REGION...SIMILAR TIMING TO WHAT WE SAW YESTERDAY...BUT EXPECT
ACTIVITY TO BE A LITTLE MORE POTENT THIS EVENING. DO NOT EXPECT
THIS ACTIVITY TO SURVIVE AS IT REACHES THE PIEDMONT.
HOWEVER...MODELS SHOW...ESPECIALLY THE GFS...POTENTIAL TSRA
DEVELOPMENT ACROSS THE NC PIEDMONT...LIFTING NORTHWARD TOWARD
LYH/DAN/EVEN ROA BY LATE AFTERNOON. HAVE PLAYED SOME POTENTIAL FOR
THIS INTO THE TAFS. OTHERWISE...MOSTLY MVFR CIGS AND MVFR VSBYS IN
VCTS AND/OR TSRA MOSTLY AFT 00Z...AGAIN LITTLE OF WHICH SHOULD
REACH THE PIEDMONT. S-SW WINDS 5-10KTS THROUGH TAF VALID
PERIOD...WITH LOW END GUSTS ACROSS THE PIEDMONT.
MEDIUM TO HIGH CONFIDENCE IN CIGS/VSBYS THROUGH TAF VALID PERIOD.
HIGH CONFIDENCE IN WIND SPD/DIR THROUGH TAF VALID PERIOD.
AS OF 202 AM EDT WEDNESDAY...
THE MAIN CONCERN THIS MORNING APPEARS TO BE FOG AROUND AREAS THAT
HAD HEAVY RAINFALL RECENTLY. LATEST DATA SUGGESTS PATCHY FOG WITH
SOME AREAS OF LOCALLY DENSE FOG. IFR TO LIFR FOG WILL BE POSSIBLE.
THE EARLIER SHOWERS HAVE DISSIPATED. ONLY ISOLATED LIGHT RAIN
SHOWERS ARE EXPECTED THIS MORNING.
A QUICK IMPROVEMENT TO CONDITIONS WEDNESDAY MORNING WITH THE ONSET
OF HEATING AND DECENT MIXING BY MID OR LATE MORNING. THINK ALL SITES
WILL BE VFR BY 15Z/11AM BUT WITH A BETTER SHOT AT AFTERNOON
CONVECTION DEVELOPING ESPCLY WEST OF THE BLUE RIDGE BY 20Z/4PM. WITH
POTENTIAL TO SEE A BAND OF SHRA/TSRA DEVELOP WESTERN
SLOPES...INCLUDED A PREVAILING -TSRA THREAT AT BOTH KBLF/KLWB
WEDNESDAY AFTERNOON WHILE LEAVING ELSW VFR W/OUT CONVECTION UNDER
SCTD/BKN 5-6K FT CU FIELDS.
THE REGION STAYS IN A WARM...MOIST AIRMASS THROUGH THURSDAY AHEAD
OF A COLD FRONT THAT SHOULD PUSH THROUGH LATE IN THE DAY THURSDAY.
THIS WILL BRING THE BEST COVERAGE OF SHOWERS WEDNESDAY NIGHT INTO
THURSDAY ALONG WITH AREAS OF LATE NIGHT/EARLY MORNING FOG.
HIGH PRESSURE AND BETTER FLYING CONDITIONS ARE EXPECTED ON FRIDAY
AND THROUGH MUCH OF THE WEEKEND BEHIND THE FRONT.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/JH/KK
SHORT TERM...WP
LONG TERM...WP
AVIATION...RAB
AREA FORECAST DISCUSSION...ISSUED BY WFO RALEIGH NC
NWS BLACKSBURG VA
340 AM EDT WED MAY 22 2013
.SYNOPSIS...
A LARGE LOW PRESSURE SYSTEM WILL TRACK FROM THE CENTRAL PLAINS INTO
THE GREAT LAKES BY THURSDAY. THIS SYSTEM WILL PUSH A COLD FRONT
THROUGH THE AREA THURSDAY INTO THURSDAY EVENING... FOLLOWED BY HIGH
PRESSURE ON FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 340 AM EDT WEDNESDAY...
A COUPLE OF CONCERNS TODAY. THE MAIN CONCERN IS WITH THE POTENTIAL
FOR ISOLATED HEAVY RAIN IN THUNDERSTORMS THIS AFTERNOON. THE LOWEST
FLASH FLOOD GUIDANCE IS CURRENTLY OBSERVED IN AREAS THAT HAVE
RECEIVED HEAVY RAIN RECENTLY AND MOSTLY IN THE MOUNTAINS INCLUDING
WATAUGA... ASHE... GRAYSON... INTO SMYTH AND TAZEWELL OF VA.
HOWEVER... GIVEN THE EXPECTED SCATTERED NATURE OF THE CONVECTION
THIS AFTERNOON... IT APPEARS THAT THE FLOODING THREAT WILL BE
ISOLATED. THEREFORE... OPTED OUT OF A FLASH FLOOD WATCH AT THE
CURRENT TIME. THE LATEST HI-RES MODELS INCLUDING THE HRRR INDICATE
AT LEAST SCATTERED THUNDERSTORMS WILL DEVELOP OVER OUR REGION THIS
AFTERNOON... PRIMARILY OVER THE MOUNTAINS AND FOOTHILLS SPREADING
NE INTO THE VA PIEDMONT LATE THIS AFTERNOON AS WELL. WE WILL
CONTINUE THE CHANCE CATEGORY POP FOR THOSE ZONES THIS AFTERNOON.
EVEN MORE PROBLEMATIC MAY BE THE POSSIBLE LINE OF CONVECTION THAT
THE HI-RES MODELS AND EVEN A FEW OF THE OPERATIONAL MODELS ARE
PICKING UP ON ACROSS KY/TN THIS AFTERNOON. SOME OF THESE MODELS
INDICATE A POTENTIAL MCS THAT MAY HOLD TOGETHER LONG ENOUGH TO SURGE
INTO FAR SW VA... SOUTHERN WVA... AND POSSIBLY NORTHWEST NC BETWEEN
00Z AND 06Z TONIGHT. IT IS UNCLEAR HOW STRONG OR HOW FAST THIS
CONVECTION WOULD BE AT THE CURRENT TIME. IF THIS APPEARS MORE LIKELY
IN THE MODEL RUNS TODAY... THERE MAY BE A CONCERN WITH FLASH
FLOODING THIS EVENING. WE WILL GO WITH HIGH CHANCE TO LOW END LIKELY
THIS EVENING TO COVER THIS POTENTIAL.
THE SLIGHT RISK FOR SEVERE CONVECTION CONTINUES TO BE JUST WEST OF
OUR REGION TODAY INTO TONIGHT.
CONDITIONS TODAY WILL BE WARM AND HUMID WITH THE SOUTHERLY FLOW OUT
AHEAD OF THE APPROACHING COLD FRONT AND UPPER TROUGH. HIGHS
TEMPERATURES SHOULD REACH THE MID 70S IN THE MOUNTAINS TO THE MID
80S IN THE SOUTHEAST. LOWS TONIGHT WILL DIP BACK INTO THE 50S TO MID
60S SE.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
AS OF 320 AM EDT WEDNESDAY...
A LEAD SURFACE TROUGH OR CONVECTIVE OUTFLOW MAY AFFECT THE REGION
BEFORE THE ACTUAL COLD FRONT ARRIVES THURSDAY. THIS MAY AFFECT THE
CONVECTIVE CHANCES GREATLY AS THE MAIN COLD FRONT ARRIVES THURSDAY.
OTHERWISE... A PERIOD OF LIKELY POP CAN BE EXPECTED WITH THE FRONT
THURSDAY... POSSIBLY LASTING INTO THE EARLY EVENING AROUND DANVILLE.
LACK OF HEATING THURSDAY... ESPECIALLY WEST OF THE BLUE RIDGE MAY
ALSO LIMIT DESTABILIZATION. THE AREA WITH THE BETTER INSOLATION
COULD BE SOUTHSIDE VA/NW NC PIEDMONT. AT THIS TIME...THE STORM
PREDICTION CENTER HAS A 5 PERCENT THREAT OF SVR WX MAINLY OVER THE
PIEDMONT AND TIDEWATER AREAS OF VA/NC.
THE FRONT WILL BE EAST OF THE AREA GOING INTO THURSDAY EVENING WITH
LINGERING SHORTWAVE INDUCED SHOWERS ACROSS THE MTNS OVERNIGHT. THE
MAIN SHORTWAVE SHIFTS EAST BY 12Z FRIDAY WITH DRIER AND COOLER AIR
ARRIVING. HIGHS FRIDAY WILL RANGE FROM THE LOWER TO MID 60S WEST TO
THE LOWER TO MID 70S EAST.
FRIDAY NIGHT AND SATURDAY:
QUITE WEATHER IS EXPECTED TO RETURN FOR THE REST OF THE SHORT TERM
FORECAST... WITH THE MID LEVEL TROUGH AXIS HAVING PUSHED TO THE EAST
OF THE AREA BY FRIDAY EVENING AND HIGH PRESSURE AT THE SURFACE
BUILDING INTO THE REGION FOR THIS TIME FRAME. THIS WILL YIELD
GENERALLY COOL AND DRY CONDITIONS... WITH BELOW NORMAL TEMPS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 130 PM EDT TUESDAY
FOR THE LONG RANGE FORECAST...THE MODELS KEEP A TROUGH IN PLACE
EARLY ON AND THEN GO MORE TOWARD A ZONAL TO RIDGE CONFIGURATION BY
THE END OF THE PERIOD.
WE SHOULD BE MAINLY DRY AS SFC HIGH BUILDS ACROSS THIS WEEKEND...SO
WEEKEND HOLIDAY PLANS ARE LOOKING GOOD FOR OUTDOOR ACTIVITIES AT
LEAST SATURDAY...AS THE LATEST ECMWF SHOWS ANOTHER WEAK SHORTWAVE
PUSHING ACROSS BY SUNDAY AND MAY BRING SOME SHOWERS ACROSS THE MTN
EMPIRE OF SW VA/INTO THE NC MTNS SUNDAY MORNING.
THE FLOW SWINGS MORE TOWARD THE SOUTHEAST SUNDAY EVENING INTO EARLY
NEXT WEEK WITH INCREASING HUMIDITY AND TEMPS. MODELS KEEPING MORE
ACTIVE WEATHER ACROSS THE OHIO VALLEY AND WEST...ALTHOUGH A WESTERLY
FLOW ALOFT CAN BRING STORMS WORKING EAST INTO THE MTNS. GIVEN WPC
SOLUTION OF THE ECMWF ENSEMBLE WILL KEEP THE FORECAST MORE ON THE
LOW CHANCE SIDE...BUT IF THE 12Z ECMWF VERIFIES WE COULD BE GETTING
SOAKED AGAIN MONDAY-WEDNESDAY.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 202 AM EDT WEDNESDAY...
THE MAIN CONCERN THIS MORNING APPEARS TO BE FOG AROUND AREAS THAT
HAD HEAVY RAINFALL RECENTLY. LATEST DATA SUGGESTS PATCHY FOG WITH
SOME AREAS OF LOCALLY DENSE FOG. IFR TO LIFR FOG WILL BE POSSIBLE.
THE EARLIER SHOWERS HAVE DISSIPATED. ONLY ISOLATED LIGHT RAIN
SHOWERS ARE EXPECTED THIS MORNING.
A QUICK IMPROVEMENT TO CONDITIONS WEDNESDAY MORNING WITH THE ONSET
OF HEATING AND DECENT MIXING BY MID OR LATE MORNING. THINK ALL SITES
WILL BE VFR BY 15Z/11AM BUT WITH A BETTER SHOT AT AFTERNOON
CONVECTION DEVELOPING ESPCLY WEST OF THE BLUE RIDGE BY 20Z/4PM. WITH
POTENTIAL TO SEE A BAND OF SHRA/TSRA DEVELOP WESTERN
SLOPES...INCLUDED A PREVAILING -TSRA THREAT AT BOTH KBLF/KLWB
WEDNESDAY AFTERNOON WHILE LEAVING ELSW VFR W/OUT CONVECTION UNDER
SCTD/BKN 5-6K FT CU FIELDS.
THE REGION STAYS IN A WARM...MOIST AIRMASS THROUGH THURSDAY AHEAD
OF A COLD FRONT THAT SHOULD PUSH THROUGH LATE IN THE DAY THURSDAY.
THIS WILL BRING THE BEST COVERAGE OF SHOWERS WEDNESDAY NIGHT INTO
THURSDAY ALONG WITH AREAS OF LATE NIGHT/EARLY MORNING FOG.
HIGH PRESSURE AND BETTER FLYING CONDITIONS ARE EXPECTED ON FRIDAY
AND THROUGH MUCH OF THE WEEKEND BEHIND THE FRONT.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...PWB
SHORT TERM...PWB/BSD/WP
LONG TERM...WP
AVIATION.../WFORAH
AREA FORECAST DISCUSSION...ISSUED BY WFO RALEIGH NC
NWS BLACKSBURG VA
320 AM EDT WED MAY 22 2013
.SYNOPSIS...
A LARGE LOW PRESSURE SYSTEM WILL TRACK FROM THE CENTRAL PLAINS INTO
THE GREAT LAKES BY THURSDAY. THIS SYSTEM WILL PUSH A COLD FRONT
THROUGH THE AREA THURSDAY INTO THURSDAY EVENING... FOLLOWED BY HIGH
PRESSURE ON FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 320 AM EDT WEDNESDAY...
A COUPLE OF CONCERNS TODAY. THE MAIN CONCERN IS WITH THE POTENTIAL
FOR ISOLATED HEAVY RAIN IN THUNDERSTORMS THIS AFTERNOON. THE LOWEST
FLASH FLOOD GUIDANCE IS CURRENTLY OBSERVED IN AREAS THAT HAVE
RECEIVED HEAVY RAIN RECENTLY AND MOSTLY IN THE MOUNTAINS INCLUDING
WATAUGA... ASHE... GRAYSON... INTO SMYTH AND TAZEWELL OF VA.
HOWEVER... GIVEN THE EXPECTED SCATTERED NATURE OF THE CONVECTION
THIS AFTERNOON... IT APPEARS THAT THE FLOODING THREAT WILL BE
ISOLATED. THEREFORE... OPTED OUT OF A FLASH FLOOD WATCH AT THE
CURRENT TIME. THE LATEST HI-RES MODELS INCLUDING THE HRRR INDICATE
AT LEAST SCATTERED THUNDERSTORMS WILL DEVELOP OVER OUR REGION THIS
AFTERNOON... PRIMARILY OVER THE MOUNTAINS AND FOOTHILLS SPREADING
NE INTO THE VA PIEDMONT LATE THIS AFTERNOON AS WELL. WE WILL
CONTINUE THE CHANCE CATEGORY POP FOR THOSE ZONES THIS AFTERNOON.
EVEN MORE PROBLEMATIC MAY BE THE POSSIBLE LINE OF CONVECTION THAT
THE HI-RES MODELS AND EVEN A FEW OF THE OPERATIONAL MODELS ARE
PICKING UP ON ACROSS KY/TN THIS AFTERNOON. SOME OF THESE MODELS
INDICATE A POTENTIAL MCS THAT MAY HOLD TOGETHER LONG ENOUGH TO SURGE
INTO FAR SW VA... SOUTHERN WVA... AND POSSIBLY NORTHWEST NC BETWEEN
00Z AND 06Z TONIGHT. IT IS UNCLEAR HOW STRONG OR HOW FAST THIS
CONVECTION WOULD BE AT THE CURRENT TIME. IF THIS APPEARS MORE LIKELY
IN THE MODEL RUNS TODAY... THERE MAY BE A CONCERN WITH FLASH
FLOODING THIS EVENING. WE WILL GO WITH HIGH CHANCE TO LOW END LIKELY
THIS EVENING TO COVER THIS POTENTIAL.
THE SLIGHT RISK FOR SEVERE CONVECTION CONTINUES TO BE JUST WEST OF
OUR REGION TODAY INTO TONIGHT.
CONDITIONS TODAY WILL BE WARM AND HUMID WITH THE SOUTHERLY FLOW OUT
AHEAD OF THE APPROACHING COLD FRONT AND UPPER TROUGH. HIGHS
TEMPERATURES SHOULD REACH THE MID 70S IN THE MOUNTAINS TO THE MID
80S IN THE SOUTHEAST. LOWS TONIGHT WILL DIP BACK INTO THE 50S TO MID
60S SE.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AS OF 320 AM EDT WEDNESDAY...
A LEAD SURFACE TROUGH OR CONVECTIVE OUTFLOW MAY AFFECT THE REGION
BEFORE THE ACTUAL COLD FRONT ARRIVES THURSDAY. THIS MAY AFFECT THE
CONVECTIVE CHANCES GREATLY AS THE MAIN COLD FRONT ARRIVES THURSDAY.
OTHERWISE... A PERIOD OF LIKELY POP CAN BE EXPECTED WITH THE FRONT
THURSDAY... POSSIBLY LASTING INTO THE EARLY EVENING AROUND DANVILLE.
LACK OF HEATING THURSDAY... ESPECIALLY WEST OF THE BLUE RIDGE MAY
ALSO LIMIT DESTABILIZATION. THE AREA WITH THE BETTER INSOLATION
COULD BE SOUTHSIDE VA/NW NC PIEDMONT. AT THIS TIME...THE STORM
PREDICTION CENTER HAS A 5 PERCENT THREAT OF SVR WX MAINLY OVER THE
PIEDMONT AND TIDEWATER AREAS OF VA/NC.
THE FRONT WILL BE EAST OF THE AREA GOING INTO THURSDAY EVENING WITH
LINGERING SHORTWAVE INDUCED SHOWERS ACROSS THE MTNS OVERNIGHT. THE
MAIN SHORTWAVE SHIFTS EAST BY 12Z FRIDAY WITH DRIER AND COOLER AIR
ARRIVING. HIGHS FRIDAY WILL RANGE FROM THE LOWER TO MID 60S WEST TO
THE LOWER TO MID 70S EAST.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 130 PM EDT TUESDAY
FOR THE LONG RANGE FORECAST...THE MODELS KEEP A TROUGH IN PLACE
EARLY ON AND THEN GO MORE TOWARD A ZONAL TO RIDGE CONFIGURATION BY
THE END OF THE PERIOD.
WE SHOULD BE MAINLY DRY AS SFC HIGH BUILDS ACROSS THIS WEEKEND...SO
WEEKEND HOLIDAY PLANS ARE LOOKING GOOD FOR OUTDOOR ACTIVITIES AT
LEAST SATURDAY...AS THE LATEST ECMWF SHOWS ANOTHER WEAK SHORTWAVE
PUSHING ACROSS BY SUNDAY AND MAY BRING SOME SHOWERS ACROSS THE MTN
EMPIRE OF SW VA/INTO THE NC MTNS SUNDAY MORNING.
THE FLOW SWINGS MORE TOWARD THE SOUTHEAST SUNDAY EVENING INTO EARLY
NEXT WEEK WITH INCREASING HUMIDITY AND TEMPS. MODELS KEEPING MORE
ACTIVE WEATHER ACROSS THE OHIO VALLEY AND WEST...ALTHOUGH A WESTERLY
FLOW ALOFT CAN BRING STORMS WORKING EAST INTO THE MTNS. GIVEN WPC
SOLUTION OF THE ECMWF ENSEMBLE WILL KEEP THE FORECAST MORE ON THE
LOW CHANCE SIDE...BUT IF THE 12Z ECMWF VERIFIES WE COULD BE GETTING
SOAKED AGAIN MONDAY-WEDNESDAY.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 202 AM EDT WEDNESDAY...
THE MAIN CONCERN THIS MORNING APPEARS TO BE FOG AROUND AREAS THAT
HAD HEAVY RAINFALL RECENTLY. LATEST DATA SUGGESTS PATCHY FOG WITH
SOME AREAS OF LOCALLY DENSE FOG. IFR TO LIFR FOG WILL BE POSSIBLE.
THE EARLIER SHOWERS HAVE DISSIPATED. ONLY ISOLATED LIGHT RAIN
SHOWERS ARE EXPECTED THIS MORNING.
A QUICK IMPROVEMENT TO CONDITIONS WEDNESDAY MORNING WITH THE ONSET
OF HEATING AND DECENT MIXING BY MID OR LATE MORNING. THINK ALL SITES
WILL BE VFR BY 15Z/11AM BUT WITH A BETTER SHOT AT AFTERNOON
CONVECTION DEVELOPING ESPCLY WEST OF THE BLUE RIDGE BY 20Z/4PM. WITH
POTENTIAL TO SEE A BAND OF SHRA/TSRA DEVELOP WESTERN
SLOPES...INCLUDED A PREVAILING -TSRA THREAT AT BOTH KBLF/KLWB
WEDNESDAY AFTERNOON WHILE LEAVING ELSW VFR W/OUT CONVECTION UNDER
SCTD/BKN 5-6K FT CU FIELDS.
THE REGION STAYS IN A WARM...MOIST AIRMASS THROUGH THURSDAY AHEAD
OF A COLD FRONT THAT SHOULD PUSH THROUGH LATE IN THE DAY THURSDAY.
THIS WILL BRING THE BEST COVERAGE OF SHOWERS WEDNESDAY NIGHT INTO
THURSDAY ALONG WITH AREAS OF LATE NIGHT/EARLY MORNING FOG.
HIGH PRESSURE AND BETTER FLYING CONDITIONS ARE EXPECTED ON FRIDAY
AND THROUGH MUCH OF THE WEEKEND BEHIND THE FRONT.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...PWB
SHORT TERM...PWB/WP
LONG TERM...WP
AVIATION.../WFORAH
AREA FORECAST DISCUSSION...ISSUED BY WFO RALEIGH NC
NWS BLACKSBURG VA
202 AM EDT WED MAY 22 2013
.SYNOPSIS...
AN UPPER LEVEL AREA OF LOW PRESSURE WILL DRIFT EAST AND OFFSHORE
OVERNIGHT. A LARGE LOW PRESSURE SYSTEM WILL TRACK FROM THE
CENTRAL PLAINS INTO THE GREAT LAKES BY THURSDAY. THIS SYSTEM WILL
PUSH A COLD FRONT THROUGH THE AREA THURSDAY...FOLLOWED BY HIGH
PRESSURE ON FRIDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 915 PM EDT TUESDAY...
BAND OF WEAKENING CONVECTION ASSOCIATED WITH OLD OUTFLOW BAND TO
THE WEST CONTINUES TO FADE ALONG THE WESTERN SLOPES ATTM WHILE NEW
OUTFLOW HAS GIVEN RISE TO ADDED SHRA/TSRA OVER THE WESTERN RIDGES.
LATEST MESO ANALYSIS SHOWS STILL ENOUGH INSTABILITY TO KEEP STORMS
GOING A WHILE LONGER MOUNTAINS WITH SOME OF THIS COVERAGE PERHAPS
DEVELOPING ACROSS THE BLUE RIDGE WHERE THE BEST LEFTOVER CAPES
EXIST. APPEARS THE OVERALL SEVERE THREAT SHOULD SLOWLY FADE PER
LOSS OF HEATING BUT LOW WET BULBS AND LOTS OF DRY AIR ALOFT OFF
EVENING SOUNDINGS STILL SUPPORT AT LEAST ISOLATED SEVERE POTENTIAL
THROUGH MIDNIGHT ESPCLY IF STORMS BECOME MORE LINEAR. THEREFORE
NUDGED UP POPS TO LOW LIKELYS FAR WEST OVER THE NEW FEW HOURS
WHILE KEEPING A SCATTERED NATURE FARTHER EAST DESPITE THE LACK OF
COVERAGE OFF THE LATEST HRRR SHORTLY AFTER MIDNIGHT. LOW LEVELS
ESPCLY EAST SHOW A BIT MORE DRYING THIS EVENING WITH SOME LIGHT
MIXING ONGOING WHICH SHOULD SLOW DOWN FOG FORMATION UNTIL LATE
EXCEPT WHERE RAINFALL HAS ALREADY OCCURRED. HOWEVER MOIST
DEWPOINTS WILL HOLD TEMPS MOSTLY IN THE MUGGY 60S WITH ONLY THE
DEEPER VALLEYS AND SPOTS SEEING SHOWERS PERHAPS FALLING INTO THE
50S LATE.
WARM AND HUMID CONDITIONS CONTINUE ON WEDNESDAY IN THE SOUTHERLY
FLOW OUT AHEAD OF THE APPROACHING COLD FRONT AND UPPER TROUGH.
INCREASED POPS FROM WEST TO EAST ON WEDNESDAY...WITH HIGHEST POPS
ALONG WESTERN MOUNTAINS. THE SWODY2 (DAY TWO CONVECTIVE OUTLOOK)
HAS THE SLIGHT RISK JUST TO OUR WEST ON WEDNESDAY. PLAYED HIGHS
TEMPERATURES COOLER ON WEDNESDAY WITH READINGS FROM THE MID 70S IN
THE MOUNTAINS TO THE MID 80S IN THE SOUTHEAST.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AS OF 255 PM EDT TUESDAY...
HAVE A COUPLE DAYS MORE OF HUMID WEATHER BEFORE FRONT SWINGS ACROSS
THURSDAY AND BRINGS A RETURN TO LOWER DEWPOINTS.
UNTIL THEN...NO MAJOR CHANGES TO THE FORECAST. WEDNESDAY NIGHT A
PIECE OF SHORTWAVE ENERGY ARRIVES ACROSS THE CENTRAL APPALACHIANS
WHICH CREATES AN AREA OF SHOWERS AND STORMS...MAINLY AFFECTING THE
WRN EDGE OF THE FORECAST AREA. THE BETTER PUSH OF THE FRONT ON
THURSDAY COMBINED WITH BETTER UPPER SUPPORT SHOULD BRING SOME
ENHANCED THREAT OF SHOWERS AND STORMS. TIMING OF THIS FRONT DOES
VARY SOMEWHAT FROM THE MODELS BUT ENOUGH AGREEMENT TO HAVE HIGH
CHANCE TO LIKLEY IN THE AREA THURSDAY. TIMING ALSO GIVES ISSUES TO
SVR THREAT. ATTM...EXPECT A LINE OF SHRA/TSRA TO BE IN THE MTNS IN
THE MORNING AND MOVING INTO THE PIEDMONT BY EARLY AFTERNOON. NOT
SEEING A LOT OF HEATING AS CLOUDS WILL BE GENEROUSLY SPREAD. ONE
AREA WITH THE BETTER INSOLATION COULD BE SOUTHSIDE VA/NW NC
PIEDMONT. AT THIS TIME...THE STORM PREDICTION CENTER HAS A 5 PERCENT
THREAT OF SVR WX MAINLY OVER THE PIEDMONT AND TIDEWATER AREAS OF
VA/NC.
THE FRONT WILL BE EAST OF THE AREA GOING INTO THURSDAY EVENING WITH
LINGERING SHORTWAVE INDUCED SHOWERS ACROSS THE MTNS OVERNIGHT. THE
MAIN SHORTWAVE SHIFTS EAST BY 12Z FRIDAY WITH DRIER AND COOLER AIR
ARRIVING. HIGHS FRIDAY WILL RANGE FROM THE LOWER TO MID 60S WEST TO
THE LOWER TO MID 70S EAST.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 130 PM EDT TUESDAY
FOR THE LONG RANGE FORECAST...THE MODELS KEEP A TROUGH IN PLACE
EARLY ON AND THEN GO MORE TOWARD A ZONAL TO RIDGE CONFIGURATION BY
THE END OF THE PERIOD.
WE SHOULD BE MAINLY DRY AS SFC HIGH BUILDS ACROSS THIS WEEKEND...SO
WEEKEND HOLIDAY PLANS ARE LOOKING GOOD FOR OUTDOOR ACTIVITIES AT
LEAST SATURDAY...AS THE LATEST ECMWF SHOWS ANOTHER WEAK SHORTWAVE
PUSHING ACROSS BY SUNDAY AND MAY BRING SOME SHOWERS ACROSS THE MTN
EMPIRE OF SW VA/INTO THE NC MTNS SUNDAY MORNING.
THE FLOW SWINGS MORE TOWARD THE SOUTHEAST SUNDAY EVENING INTO EARLY
NEXT WEEK WITH INCREASING HUMIDITY AND TEMPS. MODELS KEEPING MORE
ACTIVE WEATHER ACROSS THE OHIO VALLEY AND WEST...ALTHOUGH A WESTERLY
FLOW ALOFT CAN BRING STORMS WORKING EAST INTO THE MTNS. GIVEN WPC
SOLUTION OF THE ECMWF ENSEMBLE WILL KEEP THE FORECAST MORE ON THE
LOW CHANCE SIDE...BUT IF THE 12Z ECMWF VERIFIES WE COULD BE GETTING
SOAKED AGAIN MONDAY-WEDNESDAY.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 202 AM EDT WEDNESDAY...
THE MAIN CONCERN THIS MORNING APPEARS TO BE FOG AROUND AREAS THAT
HAD HEAVY RAINFALL RECENTLY. LATEST DATA SUGGESTS PATCHY FOG WITH
SOME AREAS OF LOCALLY DENSE FOG. IFR TO LIFR FOG WILL BE POSSIBLE.
THE EARLIER SHOWERS HAVE DISSIPATED. ONLY ISOLATED LIGHT RAIN
SHOWERS ARE EXPECTED THIS MORNING.
A QUICK IMPROVEMENT TO CONDITIONS WEDNESDAY MORNING WITH THE ONSET
OF HEATING AND DECENT MIXING BY MID OR LATE MORNING. THINK ALL SITES
WILL BE VFR BY 15Z/11AM BUT WITH A BETTER SHOT AT AFTERNOON
CONVECTION DEVELOPING ESPCLY WEST OF THE BLUE RIDGE BY 20Z/4PM. WITH
POTENTIAL TO SEE A BAND OF SHRA/TSRA DEVELOP WESTERN
SLOPES...INCLUDED A PREVAILING -TSRA THREAT AT BOTH KBLF/KLWB
WEDNESDAY AFTERNOON WHILE LEAVING ELSW VFR W/OUT CONVECTION UNDER
SCTD/BKN 5-6K FT CU FIELDS.
THE REGION STAYS IN A WARM...MOIST AIRMASS THROUGH THURSDAY AHEAD
OF A COLD FRONT THAT SHOULD PUSH THROUGH LATE IN THE DAY THURSDAY.
THIS WILL BRING THE BEST COVERAGE OF SHOWERS WEDNESDAY NIGHT INTO
THURSDAY ALONG WITH AREAS OF LATE NIGHT/EARLY MORNING FOG.
HIGH PRESSURE AND BETTER FLYING CONDITIONS ARE EXPECTED ON FRIDAY
AND THROUGH MUCH OF THE WEEKEND BEHIND THE FRONT.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/JH/KK
SHORT TERM...WP
LONG TERM...WP
AVIATION.../WFORAH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1252 PM CDT WED MAY 22 2013
.SHORT TERM...(TODAY AND FRIDAY)
ISSUED AT 309 AM CDT WED MAY 22 2013
MAIN FORECAST CONCERN ARE PRECIPITATION CHANCES THROUGH TONIGHT...
THEN POSSIBLE PATCHY FROST OVER CENTRAL WISCONSIN THURSDAY NIGHT.
LATEST WATER VAPOR SATELLITE IMAGERY SHOWING UPPER LEVEL LOW OVER
THE NORTHERN PLAINS AND SHORTWAVE TROUGHS ROTATING AROUND THE UPPER
LEVEL LOW. LATEST MOSAIC RADAR INDICATING SCATTERED SHOWERS
EXTENDING FROM LAKE SUPERIOR INTO SOUTHWEST MINNESOTA AND ANOTHER
AREA OF SHOWERS AND THUNDERSTORMS FROM WESTERN ILLINOIS INTO
SOUTHERN LAKE MICHIGAN.
THE 22.00Z GFS/NAM ARE IN GOOD AGREEMENT WITH OVERALL UPPER LEVEL
FLOW THROUGH FORECAST PERIOD. BOTH MODELS ARE IN DECENT AGREEMENT
LIFTING SHORTWAVE TROUGH OVER MISSOURI AND EASTERN KANSAS
INTO SOUTHERN WISCONSIN TODAY. THE 22.00Z GFS/NAM AND 22.03Z RAP ARE
IN AGREEMENT IN INCREASING PV ADVECTION...QG FORCING AND VERTICAL
MOTION OVER THE FORECAST AREA 12-18Z TODAY AND DEVELOP
PRECIPITATION OVER MUCH OF THE FORECAST AREA BY 18Z TODAY.
CONFIDENCE IS INCREASING THE FORECAST AREA WILL SEE PRECIPITATION
DEVELOP OVER FORECAST AREA BY 18Z. THE DETERMINISTIC MODELS INDICATE
0-6KM MOST UNSTABLE CAPE 300-500 J/KG OVER SOUTHEASTERN HALF OF THE
FORECAST AREA AFTER 15Z TODAY. WILL CONTINUE TO MENTION ISOLATED
THUNDERSTORMS.
THE 22.00Z GFS/NAM SUGGEST UPPER LEVEL LOW WEAKENS AND DRIFTS SLOWLY
EAST INTO THE GREAT LAKES REGION...AS AN UPPER LEVEL TROUGH
DIGS OVER EASTERN GREAT LAKES REGION TONIGHT. WITH SURFACE RIDGE
BUILDING INTO SOUTHERN ONTARIO AND THE WESTERN GREAT LAKES REGION...
CLOUDS AND PRECIPITATION WILL DIMINISH FROM NORTH TO SOUTH ACROSS
FORECAST AREA AFTER 06Z THURSDAY.
DRY NORTHEASTERLY FLOW ALOFT DEVELOPS OVER FORECAST AREA THURSDAY.
THE 22.00Z GFS/NAM BUFKIT SOUNDINGS ARE INDICATING FORECAST AREA
MIXING UP TO 825MB BY 21Z. THIS SHOULD ALLOW FOR DEWPOINTS TO FALL
INTO THE MIDDLE 20S TO MIDDLE 30S ACROSS MUCH OF THE FORECAST AREA
THURSDAY AFTERNOON.
NEXT CONCERN IS LOW TEMPERATURES AND PATCHY FROST FRIDAY MORNING...
WITH THE COMBINATION OF SURFACE RIDGE CENTERED AND DRY AIRMASS OVER
FORECAST AREA...TEMPERATURES ARE EXPECTED TO DROP INTO THE MIDDLE
30S ACROSS PORTIONS OF CENTRAL WISCONSIN. PATCHY FROST WILL BE
POSSIBLE ACROSS THIS PART OF THE FORECAST AREA.
.LONG TERM...(FRIDAY NIGHT INTO TUESDAY)
ISSUED AT 309 AM CDT WED MAY 22 2013
MAIN FORECAST CONCERN ARE PRECIPITATION CHANCES THROUGH FORECAST
PERIOD. THE 22.00Z GFS/ECMWF/GEM CONTINUE TO DIFFER ON TIMING OF
SHORTWAVE TROUGHS OVER-TOPPING UPPER LEVEL RIDGE OVER THE CENTRAL
UNITED STATES AND PLACEMENT OF THE SURFACE RIDGE OVER THE
GREAT LAKES REGION. WITH THIS...CONFIDENCE IN FORECAST IS LOW AND
WILL CONTINUE WITH CONSISTENCY OF PRECIPITATION CHANCES THROUGH
FORECAST PERIOD. TEMPERATURES WILL CLIMB INTO THE 60S FOR THE
MEMORIAL DAY WEEKEND AND BE IN THE 70S TUESDAY...AS THE
DETERMINISTIC MODELS INDICATE WARMER AIR ALOFT TO FILTER INTO THE
REGION BY 00Z TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1252 PM CDT WED MAY 22 2013
CLOSED LOW LOCATED OVER NORTHEAST IA WILL SLOWLY FILL IN AND
MOVE EAST INTO LOWER MI BY MORNING. PLAN ON IFR/MVFR CLOUD
COVER AND BAND OF SHRA NORTH OF THE LOW TO PERSIST INTO TONIGHT.
THEN LOOK FOR FAIRLY RAPID IMPROVEMENT INTO VFR CATEGORY AROUND
07Z AT KRST AND AROUND 09Z AT KLSE AS DRIER AIR WORKS IN FROM THE
NORTH. HIGH PRESSURE WILL PROVIDE CLEAR SKIES ON THURSDAY WITH
NORTH/NORTHEAST WINDS IN THE 10-20KT RANGE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM.....DTJ
LONG TERM......DTJ
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
645 AM CDT WED MAY 22 2013
.SHORT TERM...(TODAY AND FRIDAY)
ISSUED AT 309 AM CDT WED MAY 22 2013
MAIN FORECAST CONCERN ARE PRECIPITATION CHANCES THROUGH TONIGHT...
THEN POSSIBLE PATCHY FROST OVER CENTRAL WISCONSIN THURSDAY NIGHT.
LATEST WATER VAPOR SATELLITE IMAGERY SHOWING UPPER LEVEL LOW OVER
THE NORTHERN PLAINS AND SHORTWAVE TROUGHS ROTATING AROUND THE UPPER
LEVEL LOW. LATEST MOSAIC RADAR INDICATING SCATTERED SHOWERS
EXTENDING FROM LAKE SUPERIOR INTO SOUTHWEST MINNESOTA AND ANOTHER
AREA OF SHOWERS AND THUNDERSTORMS FROM WESTERN ILLINOIS INTO
SOUTHERN LAKE MICHIGAN.
THE 22.00Z GFS/NAM ARE IN GOOD AGREEMENT WITH OVERALL UPPER LEVEL
FLOW THROUGH FORECAST PERIOD. BOTH MODELS ARE IN DECENT AGREEMENT
LIFTING SHORTWAVE TROUGH OVER MISSOURI AND EASTERN KANSAS
INTO SOUTHERN WISCONSIN TODAY. THE 22.00Z GFS/NAM AND 22.03Z RAP ARE
IN AGREEMENT IN INCREASING PV ADVECTION...QG FORCING AND VERTICAL
MOTION OVER THE FORECAST AREA 12-18Z TODAY AND DEVELOP
PRECIPITATION OVER MUCH OF THE FORECAST AREA BY 18Z TODAY.
CONFIDENCE IS INCREASING THE FORECAST AREA WILL SEE PRECIPITATION
DEVELOP OVER FORECAST AREA BY 18Z. THE DETERMINISTIC MODELS INDICATE
0-6KM MOST UNSTABLE CAPE 300-500 J/KG OVER SOUTHEASTERN HALF OF THE
FORECAST AREA AFTER 15Z TODAY. WILL CONTINUE TO MENTION ISOLATED
THUNDERSTORMS.
THE 22.00Z GFS/NAM SUGGEST UPPER LEVEL LOW WEAKENS AND DRIFTS SLOWLY
EAST INTO THE GREAT LAKES REGION...AS AN UPPER LEVEL TROUGH
DIGS OVER EASTERN GREAT LAKES REGION TONIGHT. WITH SURFACE RIDGE
BUILDING INTO SOUTHERN ONTARIO AND THE WESTERN GREAT LAKES REGION...
CLOUDS AND PRECIPITATION WILL DIMINISH FROM NORTH TO SOUTH ACROSS
FORECAST AREA AFTER 06Z THURSDAY.
DRY NORTHEASTERLY FLOW ALOFT DEVELOPS OVER FORECAST AREA THURSDAY.
THE 22.00Z GFS/NAM BUFKIT SOUNDINGS ARE INDICATING FORECAST AREA
MIXING UP TO 825MB BY 21Z. THIS SHOULD ALLOW FOR DEWPOINTS TO FALL
INTO THE MIDDLE 20S TO MIDDLE 30S ACROSS MUCH OF THE FORECAST AREA
THURSDAY AFTERNOON.
NEXT CONCERN IS LOW TEMPERATURES AND PATCHY FROST FRIDAY MORNING...
WITH THE COMBINATION OF SURFACE RIDGE CENTERED AND DRY AIRMASS OVER
FORECAST AREA...TEMPERATURES ARE EXPECTED TO DROP INTO THE MIDDLE
30S ACROSS PORTIONS OF CENTRAL WISCONSIN. PATCHY FROST WILL BE
POSSIBLE ACROSS THIS PART OF THE FORECAST AREA.
.LONG TERM...(FRIDAY NIGHT INTO TUESDAY)
ISSUED AT 309 AM CDT WED MAY 22 2013
MAIN FORECAST CONCERN ARE PRECIPITATION CHANCES THROUGH FORECAST
PERIOD. THE 22.00Z GFS/ECMWF/GEM CONTINUE TO DIFFER ON TIMING OF
SHORTWAVE TROUGHS OVER-TOPPING UPPER LEVEL RIDGE OVER THE CENTRAL
UNITED STATES AND PLACEMENT OF THE SURFACE RIDGE OVER THE
GREAT LAKES REGION. WITH THIS...CONFIDENCE IN FORECAST IS LOW AND
WILL CONTINUE WITH CONSISTENCY OF PRECIPITATION CHANCES THROUGH
FORECAST PERIOD. TEMPERATURES WILL CLIMB INTO THE 60S FOR THE
MEMORIAL DAY WEEKEND AND BE IN THE 70S TUESDAY...AS THE
DETERMINISTIC MODELS INDICATE WARMER AIR ALOFT TO FILTER INTO THE
REGION BY 00Z TUESDAY.
&&
.AVIATION...TODAY AND TONIGHT
644 AM CDT WED MAY 22 2013
CLOSED CIRCULATION TO PASS JUST SOUTH OF THE TAF LOCATIONS OVER
THE NEXT 24 HOURS. BROAD AREA OF LIGHT SHOWERS IN THE DEFORMATION
AREA ON THE NORTHERN/WESTERN PERIPHERY. BROAD WEAK LIFT AND
AVAILABLE MOISTURE WILL KEEP SHOWERS GOING...IN AT LEAST HIT-AND-
MISS FASHION...FOR THE BULK OF THE PERIOD. ALSO OF CONCERN ARE LOW
CLOUDS. IFR IS NOT FAR AWAY AND EXPECT IT TO EXPAND BACK INTO OUR
REGION...FIRST AT KRST...AND FINALLY AT KLSE. THE PERSISTANT LOW
SYSTEM WILL FINALLY DEPART ON THURSDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM.....DTJ
LONG TERM......DTJ
AVIATION...MW
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
309 AM CDT WED MAY 22 2013
.SHORT TERM...(TODAY AND FRIDAY)
ISSUED AT 309 AM CDT WED MAY 22 2013
MAIN FORECAST CONCERN ARE PRECIPITATION CHANCES THROUGH TONIGHT...
THEN POSSIBLE PATCHY FROST OVER CENTRAL WISCONSIN THURSDAY NIGHT.
LATEST WATER VAPOR SATELLITE IMAGERY SHOWING UPPER LEVEL LOW OVER
THE NORTHERN PLAINS AND SHORTWAVE TROUGHS ROTATING AROUND THE UPPER
LEVEL LOW. LATEST MOSAIC RADAR INDICATING SCATTERED SHOWERS
EXTENDING FROM LAKE SUPERIOR INTO SOUTHWEST MINNESOTA AND ANOTHER
AREA OF SHOWERS AND THUNDERSTORMS FROM WESTERN ILLINOIS INTO
SOUTHERN LAKE MICHIGAN.
THE 22.00Z GFS/NAM ARE IN GOOD AGREEMENT WITH OVERALL UPPER LEVEL
FLOW THROUGH FORECAST PERIOD. BOTH MODELS ARE IN DECENT AGREEMENT
LIFTING SHORTWAVE TROUGH OVER MISSOURI AND EASTERN KANSAS
INTO SOUTHERN WISCONSIN TODAY. THE 22.00Z GFS/NAM AND 22.03Z RAP ARE
IN AGREEMENT IN INCREASING PV ADVECTION...QG FORCING AND VERTICAL
MOTION OVER THE FORECAST AREA 12-18Z TODAY AND DEVELOP
PRECIPITATION OVER MUCH OF THE FORECAST AREA BY 18Z TODAY.
CONFIDENCE IS INCREASING THE FORECAST AREA WILL SEE PRECIPITATION
DEVELOP OVER FORECAST AREA BY 18Z. THE DETERMINISTIC MODELS INDICATE
0-6KM MOST UNSTABLE CAPE 300-500 J/KG OVER SOUTHEASTERN HALF OF THE
FORECAST AREA AFTER 15Z TODAY. WILL CONTINUE TO MENTION ISOLATED
THUNDERSTORMS.
THE 22.00Z GFS/NAM SUGGEST UPPER LEVEL LOW WEAKENS AND DRIFTS SLOWLY
EAST INTO THE GREAT LAKES REGION...AS AN UPPER LEVEL TROUGH
DIGS OVER EASTERN GREAT LAKES REGION TONIGHT. WITH SURFACE RIDGE
BUILDING INTO SOUTHERN ONTARIO AND THE WESTERN GREAT LAKES REGION...
CLOUDS AND PRECIPITATION WILL DIMINISH FROM NORTH TO SOUTH ACROSS
FORECAST AREA AFTER 06Z THURSDAY.
DRY NORTHEASTERLY FLOW ALOFT DEVELOPS OVER FORECAST AREA THURSDAY.
THE 22.00Z GFS/NAM BUFKIT SOUNDINGS ARE INDICATING FORECAST AREA
MIXING UP TO 825MB BY 21Z. THIS SHOULD ALLOW FOR DEWPOINTS TO FALL
INTO THE MIDDLE 20S TO MIDDLE 30S ACROSS MUCH OF THE FORECAST AREA
THURSDAY AFTERNOON.
NEXT CONCERN IS LOW TEMPERATURES AND PATCHY FROST FRIDAY MORNING...
WITH THE COMBINATION OF SURFACE RIDGE CENTERED AND DRY AIRMASS OVER
FORECAST AREA...TEMPERATURES ARE EXPECTED TO DROP INTO THE MIDDLE
30S ACROSS PORTIONS OF CENTRAL WISCONSIN. PATCHY FROST WILL BE
POSSIBLE ACROSS THIS PART OF THE FORECAST AREA.
.LONG TERM...(FRIDAY NIGHT INTO TUESDAY)
ISSUED AT 309 AM CDT WED MAY 22 2013
MAIN FORECAST CONCERN ARE PRECIPITATION CHANCES THROUGH FORECAST
PERIOD. THE 22.00Z GFS/ECMWF/GEM CONTINUE TO DIFFER ON TIMING OF
SHORTWAVE TROUGHS OVER-TOPPING UPPER LEVEL RIDGE OVER THE CENTRAL
UNITED STATES AND PLACEMENT OF THE SURFACE RIDGE OVER THE
GREAT LAKES REGION. WITH THIS...CONFIDENCE IN FORECAST IS LOW AND
WILL CONTINUE WITH CONSISTENCY OF PRECIPITATION CHANCES THROUGH
FORECAST PERIOD. TEMPERATURES WILL CLIMB INTO THE 60S FOR THE
MEMORIAL DAY WEEKEND AND BE IN THE 70S TUESDAY...AS THE
DETERMINISTIC MODELS INDICATE WARMER AIR ALOFT TO FILTER INTO THE
REGION BY 00Z TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1131 PM CDT TUE MAY 21 2013
THE MAIN FOCUS AT THE TAF SITES IS WITH THE POTENTIAL FOR MVFR TO
IFR FLIGHT CONDITIONS AND RAIN SHOWERS AS A LOW PRESSURE SYSTEM
MOVES THROUGH THE REGION. THIS LOW IS CURRENTLY TO THE NORTHWEST
OF THE REGION BUT IS STARTING TO SINK TO THE SOUTHEAST. ALL OF THE
MVFR TO IFR CEILINGS ARE CURRENTLY TO THE NORTH AND WEST OF THIS
LOW AND ARE EXPECTED TO GET INTO THE REGION LATER WEDNESDAY
MORNING. THE EXACT TIMING OF THAT IS IN DOUBT...BUT RST SHOULD SEE
SOME IFR CEILINGS MOVE IN AROUND DAYBREAK WITH MVFR POSSIBLE INTO
LSE AROUND THE SAME TIME. SOME SHOWERS ARE EXPECTED TO DEVELOP IN
THE MORNING HOURS AS WELL AND LAST THROUGH MUCH OF THE DAY BEFORE
DIMINISHING IN THE EVENING HOURS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM.....DTJ
LONG TERM......DTJ
AVIATION.......HALBACH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1059 PM MDT TUE MAY 21 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 325 PM MDT TUE MAY 21 2013
EXTENDED THE WIND ADVISORY UNTIL 6 PM MDT FOR MOST OF THE NEBRASKA
PANHANDLE. AT 2 PM MDT WINDS WERE GUSTING TO 51 MPH AT SCOTTSBLUFF
AND 44 MPH AT ALLIANCE. WINDS SHOULD BEGIN A SLOW DECREASE THE
REST OF THIS AFTERNOON AND THEN DROP OFF MORE QUICKLY THIS
EVENING.
WINDS WILL SHIFT TO THE NORTHEAST OVER EASTERN AREAS TONIGHT AND
THEN TURN TO THE SOUTHEAST WEDNESDAY. THIS WILL BEGIN TO ALLOW LOW
LEVEL MOISTURE TO ADVECT WESTWARD WHICH MAY ALLOW FOR INCREASING
CHANCES OF THUNDERSTORMS THROUGH THE WEEK. KEPT A SLIGHT CHANCE
FOR SHOWERS AND THUNDERSTORMS OVER THE MOUNTAINS AND ADJACENT
PLAINS FOR WEDNESDAY AFTERNOON. MODEL SOUNDINGS SHOWING STEEP
LAPSE RATES WITH LITTLE TO NO CONVECTIVE INHIBITION. INSTABILITY
IS NOT ALL THAT GREAT SO MAINLY LOOKING AT SHOWERS WITH A FEW WEAK
THUNDERSTORMS. MODELS DO SHOW AN ELEVATED WARM FRONT MOVE EAST
ACROSS THE FORECAST AREA WEDNESDAY NIGHT. THERE MAY BE ENOUGH
INSTABILITY AND LIFT TO KEEP ISOLATED SHOWERS AND WEAK
THUNDERSTORMS PECULATING INTO THE NIGH-TIME WHILE SHIFTING EAST
INTO WESTERN NEBRASKA.
SOUTH TO SOUTHEAST WINDS SHOULD BEGIN TO RAMP UP WEDNESDAY NIGHT
AND THURSDAY. MODELS HAVE BEEN TRENDING STRONGER WITH LOW LEVEL
FLOW THURSDAY. NAM AND GFS BUFKIT SOUNDING AT LUSK SHOWING 50 KT
WINDS A FEW THOUSAND FEET ABOVE GROUND LEVEL THURSDAY AFTERNOON.
SOUNDINGS ALSO SHOWING A VERY STRONG LOW LEVEL INVERSION DUE IN
PART TO THE MOIST LOW LEVEL FLOW. KEPT A CHANCE FOR THUNDERSTORMS
MAINLY OVER THE MOUNTAINS THURSDAY. MOST LIKELY A FEW STORMS WILL
DEVELOP OVER THE LARAMIE RANGE...BUT WITH SUCH A STRONG CAP IN
PLACE...STORMS MAY HAVE A TOUGH TIME MOVING INTO LOWER ELEVATIONS.
ALONG WITH THE INVERSION EXPECTING A LOT OF STRATUS THURSDAY.
STRATUS SHOULD PUT A LID ON TEMPERATURES. FOLLOWED THE PREVIOUS
FORECAST SHIFT IN LOWERING DAYTIME HIGHS FOR THURSDAY. ALSO WARMED
THE LOW A BIT WEDNESDAY NIGHT AND THURSDAY NIGHT.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 325 PM MDT TUE MAY 21 2013
FIRST UPPER SHORTWAVE EJECTING FROM PAC NW UPPER LOW WILL MOVE
ACROSS THE AREA FRIDAY MORNING. TIMING SUCH THAT THERE MAY BE A BIT
OF CONVECTION OVER MAINLY THE PANHANDLE BUT IF SFC BOUNDARY MOVES
FAR ENOUGH EAST THE ACTIVITY WOULD BE EAST OF THE CWA. WILL KEEP
SOME LOW POPS IN PLACE UNTIL BETTER CERTAINTY. SW FLOW ALOFT
REMAIN IN PLACE OVER THE CWA OVER THE WEEKEND INTO EARLY NEXT WEEK
SO SOME AFTERNOON AND EVENING CONVECTION WILL CONTINUE TO BE A
POSSIBILITY...THOUGH TIMING WILL BE DIFFICULT. ECMWF DEPICTING IT
PRETTY MUCH DAILY WHILE GFS DRIER. WILL KEEP POPS WHERE IT LOOKS
MORE FAVORABLE SUCH AS SUNDAY AND MONDAY. TEMPERATURES WILL BE
ON THE WARM SIDE FOR MUCH OF THE PERIOD...GENERALLY A LITTLE ABOVE
SEASONAL AVERAGES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY EVENING)
ISSUED AT 1057 PM MDT TUE MAY 21 2013
LATEST SREF AND HRRR GUIDANCE SHOWING SOME WRAP AROUND LOW CLOUDS
MAKING IT INTO KCDR AND KAIA OVERNIGHT. UPSTREAM OBSERVATIONS IN
SOUTH DAKOTA REPORTING CEILINGS DOWN AROUND 1500 FEET...SO THEIR
FORECAST SEEMS REASONABLE. WENT AHEAD AND LOWERED CEILINGS AT KCDR
AND KAIA TONIGHT. VFR ELSEWHERE.
&&
.FIRE WEATHER...
ISSUED AT 325 PM MDT TUE MAY 21 2013
WINDS WILL DROP OFF QUICKLY THIS EVENING AND BECOME LIGHT. WINDS
WILL REMAIN ON THE LIGHT SIDE MAINLY IN THE 10 TO 15 MPH RANGE
WEDNESDAY BUT WILL BEGIN TO INCREASE WEDNESDAY NIGHT...WITH STRONG
SOUTHEAST WINDS ALONG AND EAST OF THE LARAMIE RANGE FOR THURSDAY.
CHANCES FOR SHOWERS AND THUNDERSTORMS WILL MAINLY BE CONFINED TO
THE MOUNTAINS WEDNESDAY AND THURSDAY AFTERNOON.
WEATHER CONDITIONS WILL VARY GREATLY FROM WEST TO EAST OVER THE
FORECAST AREA LATE THIS WEEK AND WEEKEND. RELATIVELY MOIST
CONDITIONS WILL BE FOUND EAST OF THE LARAMIE RANGE UNDER SOUTH TO
SOUTHEAST LOW LEVEL FLOW...WHILE WEST OF THE LARAMIE RANGE DRY
SOUTHWEST FLOW WILL DOMINATE PRODUCING LOW HUMIDITY.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...LIEBL
LONG TERM...RE
AVIATION...CLAYCOMB
FIRE WEATHER...LIEBL
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
421 AM EDT FRI MAY 24 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 225 AM EDT FRI MAY 24 2013
STRONG AND COOL CANADIAN HIGH PRESSURE CENTERED OVER THE GREAT
LAKES WILL BUILD ACROSS THE OHIO VALLEY THE NEXT FEW DAYS. THIS
WILL BRING BELOW NORMAL TEMPERATURES BUT DRY WEATHER FOR INDIANA
THROUGH SATURDAY NIGHT.
AS THE HIGH BEGINS TO DRIFT EAST ON SUNDAY...A WARM FRONT WILL
APPROACH INDIANA FROM THE SOUTHWEST...BRING MORE CLOUDS...WARMER
TEMPERATURES AND SMALL CHANCES FOR RAIN ON SUNDAY AFTERNOON
THROUGH MONDAY.
TEMPERATURES WILL RETURN TO NEAR NORMAL MEMORIAL DAY AND ABOVE
NORMAL BY MIDWEEK NEXT WEEK. THUNDERSTORM CHANCES WILL ALSO RETURN
NEXT WEEK AS GULF MOISTURE SPREADS NORTH ACROSS THE OHIO VALLEY.
&&
.NEAR TERM /TODAY/...
ISSUED AT 225 AM EDT FRI MAY 24 2013
SURFACE ANALYSIS EARLY THIS MORNING SHOWS A LARGE AREA OF HIGH
PRESSURE CENTERED OVER THE NORTH WOODS OF WISCONSIN AND LAKE
SUPERIOR. COOL NORTH FLOW WAS IN PLACE ACROSS INDIANA. IR PICTURES
SHOWED STRATOCU EXITING THE AREA TO THE EAST. THE WESTERN 1/2 OF
THE OF THE STATE HAD ALREADY BECOME CLEAR.
MAIN FORECAST CHALLENGE TODAY WILL BE TEMPS. FORECAST SOUNDINGS
AND TIME HEIGHTS REMAIN QUITE DRY. FORECAST SOUNDINGS SHOW
CONVECTIVE TEMPS IN THE UPPER 70S...AND GIVEN OUR 850MB TEMPS
AROUND 3-5 DEGREES AMID COLD AIR ADVECTION...WE WILL NOT GET THAT
WARM. THUS MOSTLY SUNNY SKIES EXPECTED TODAY.
BACK TO TEMPS...GIVEN OUR 850MB TEMPS AND THE COOL START AND
ONGOING COLD AIR ADVECTION WILL TREND HIGHS AT OR BELOW MAVMOS.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 225 AM EDT FRI MAY 24 2013
MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE POPS ON SUNDAY
AND SUNDAY NIGHT.
LITTLE CHANGE IS EXPECTED THROUGH SATURDAY NIGHT WITH THE ONGOING
WEATHER. THE PREVIOUSLY MENTIONED LARGE ARE OF HIGH PRESSURE WILL
REMAIN ACROSS THE GREAT LAKES AND INDIANA...CONTINUING TO DOMINATE
TH REGIONS WEATHER...PROVIDING MOSTLY CLEAR...COOL NIGHTS AND
MOSTLY SUNNY AND COOL DAYS.
ECMWF AND GFS CONTINUE TO BUILD A STRONG RIDGE OVER THE PLAINS
STATES ALOFT WITH NORTHWEST FLOW ON THE LEE SIDE OF THE RIDGE
SPILLING INTO INDIANA AND THE OHIO VALLEY. BY SATURDAY...SOME WARM
AIR ADVECTION BEGINS IN SOUTHWEST INDIANA...HOWEVER THE COLD AIR
LOOKS TO REMAIN IN PLACE THROUGH THE DAY AS 850MB TEMPS LOOK TO
HOLD NEAR 5C THROUGH THE DAY. THUS WITH A FEW MORE HIGH AND MID CLOUDS
EXPECTED ON SATURDAY WILL TREND HIGHS CLOSE TO EXPECTED PERSISTENCE.
GFS INDICATES A SHORT WAVE PUSHING THROUGH THE NORTHWEST FLOW ACROSS
INDIANA ON SUNDAY AFTERNOON AS WARM AIR ADVECTION CONTINUES IN THE
LOWER LEVELS. GULF MOISTURE REMAINS CUT OFF AND DEW POINTS LOOK TO
REMAIN IN THE RELATIVELY DRY 40S. GFS 300K ISENTROPIC SURFACE
SHOWS SOME LIFT ACROSS THE AREA ON LATE SUNDAY AFTERNOON AND INTO
SUNDAY NIGHT AS SPECIFIC HUMIDITIES RISE TO NEAR 7G/KG. FORECAST
SOUNDINGS AND TIME HEIGHTS HINT AT MORE MOISTURE AVAILABLE IN THE
COLUMN HOWEVER. THUS CONFIDENCE IN ANY RAIN REMAINS LOW AND WILL
CONTINUE TO CARRY A LOW CHC POP DURING THIS TIME PERIOD. AS FOR
TEMPS WILL CONTINUE TO HOLD VALUES AT OR BELOW MAVMOS GIVEN THE
ADDITIONAL CLOUD COVER EXPECTED ACROSS THE AREA...ALONG WITH THE
LOW PRECIPITATION CHANCES.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 152 AM EDT THU MAY 23 2013
ENSEMBLES IN GOOD AGREEMENT WITH THE LONG WAVE FEATURES DURING THIS
PERIOD. UPPER RIDGE CURRENTLY OVER THE PLAINS IS EXPECTED TO
GRADUALLY SHIFT EAST INTO THE MIDWEST AND OHIO VALLEY BY THE MIDDLE
OF NEXT WEEK. APPEARS THERE IS A POTENTIAL FOR EMBEDDED SHORT WAVE
TROUGHS TO RIDE THROUGH THE RIDGE...AT LEAST ON MONDAY AND TUESDAY.
WILL CONTINUE WITH CHANCE POPS AT THOSE TIMES.
BY NEXT WEDNESDAY AND THURSDAY...ENSEMBLES SUGGEST THE UPPER RIDGE
WILL BUILD MORE AGGRESSIVELY OVER THE AREA AS DEEP TROUGHING DEVELOPS
OVER THE WEST COAST AND ROCKIES. THIS SHOULD HELP TO CAP OFF
PRECIPITATION CHANCES LATER NEXT WEEK...WITH THE ENSEMBLES
SUGGESTING LITTLE THREAT FOR PRECIPITATION AFTER TUESDAY. WILL GO
DRY FOR NEXT WEDNESDAY AND THURSDAY.
&&
.AVIATION /DISCUSSION FOR THE 240900Z KIND TAF UPDATE/...
ISSUED AT 421 AM EDT FRI MAY 24 2013
AREA OF MVFR CEILINGS AROUND 020 CONTINUE TO DRIFT SOUTH...AFFECTING
THE KIND TERMINAL. EXTRAPOLATION OF THE BACK EDGE SUGGESTS THESE
CEILINGS WILL SCATTER OUT AT KIND AROUND 241100Z. THERE WAS SOME
POCKETS OF IFR CEILINGS AS WELL...BUT THESE SEEM TO HAVE DISSIPATED
FOR THE MOST PART BASED ON UPSTREAM OBSERVATIONS.
PREVIOUS DISCUSSION FOLLOWS.
POCKETS OF MVFR CEILINGS TO PERSIST AT KBMG AND KIND FOR THE NEXT
FEW HOURS...OTHERWISE VFR CONDITIONS EXPECTED.
STRATOCU DECK CONTINUES TO ERODE FROM THE NORTHWEST...WITH KHUF AND
KLAF NOW MAINLY CLEAR WITH PREDOMINANT CEILING UP TO 3500-4000FT AT
BOTH KBMG AND KIND. RAP DATA INDICATING THAT A N/NE FLOW WILL KEEP
AXIS OF DEEPER MOISTURE THROUGH THE BOUNDARY LAYER ALIGNED ACROSS
THE REGION FOR THE NEXT 3-6 HOURS. CURRENT SATELLITE IMAGERY
SUPPORTS THIS THINKING AS AREA OF LOWER CLOUDS DRIFTING SOUTH ACROSS
NORTHERN INDIANA. WILL KEEP CLOUDS IN AT KBMG AND KIND FOR THE NEXT
FEW HOURS WITH CLEARING THEREAFTER AS DRIER AIR ADVECTS INTO THE
REGION WITH THE HIGH. NORTHERLY WINDS AT 10-15KTS CURRENTLY WILL
DIMINISH TO 5-10KTS LATE.
THE HIGH WILL EXPAND ACROSS THE OHIO VALLEY WITH QUIET WEATHER
TODAY. PRESENCE OF THE DEPARTING LOW LEVEL THERMAL TROUGH INTO THE
AFTERNOON MAY BE JUST ENOUGH TO GENERATE A FEW CU AT KIND.
OTHERWISE...ANTICIPATE CLEAR SKIES AND NORTHERLY WINDS TO NEAR 10KTS
ALL DAY. MAY START TO SEE SOME THIN CIRRUS DRIFT INTO THE REGION
TONIGHT AS IT SPILLS OVER TOP OF THE UPPER RIDGE OVER THE CENTRAL
PLAINS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...PUMA
NEAR TERM...PUMA
SHORT TERM...PUMA
LONG TERM....JAS
AVIATION...RYAN/JAS
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
225 AM EDT FRI MAY 24 2013
.UPDATE...
THE SYNOPSIS...NEAR TERM...SHORT TERM AND LONG TERM SECTIONS HAVE
BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 225 AM EDT FRI MAY 24 2013
STRONG AND COOL CANADIAN HIGH PRESSURE CENTERED OVER THE GREAT
LAKES WILL BUILD ACROSS THE OHIO VALLEY THE NEXT FEW DAYS. THIS
WILL BRING BELOW NORMAL TEMPERATURES BUT DRY WEATHER FOR INDIANA
THROUGH SATURDAY NIGHT.
AS THE HIGH BEGINS TO DRIFT EAST ON SUNDAY...A WARM FRONT WILL
APPROACH INDIANA FROM THE SOUTHWEST...BRING MORE CLOUDS...WARMER
TEMPERATURES AND SMALL CHANCES FOR RAIN ON SUNDAY AFTERNOON
THROUGH MONDAY.
TEMPERATURES WILL RETURN TO NEAR NORMAL MEMORIAL DAY AND ABOVE
NORMAL BY MIDWEEK NEXT WEEK. THUNDERSTORM CHANCES WILL ALSO RETURN
NEXT WEEK AS GULF MOISTURE SPREADS NORTH ACROSS THE OHIO VALLEY.
&&
.NEAR TERM /TODAY/...
ISSUED AT 225 AM EDT FRI MAY 24 2013
SURFACE ANALYSIS EARLY THIS MORNING SHOWS A LARGE AREA OF HIGH
PRESSURE CENTERED OVER THE NORTH WOODS OF WISCONSIN AND LAKE
SUPERIOR. COOL NORTH FLOW WAS IN PLACE ACROSS INDIANA. IR PICTURES
SHOWED STRATOCU EXITING THE AREA TO THE EAST. THE WESTERN 1/2 OF
THE OF THE STATE HAD ALREADY BECOME CLEAR.
MAIN FORECAST CHALLENGE TODAY WILL BE TEMPS. FORECAST SOUNDINGS
AND TIME HEIGHTS REMAIN QUITE DRY. FORECAST SOUNDINGS SHOW
CONVECTIVE TEMPS IN THE UPPER 70S...AND GIVEN OUR 850MB TEMPS
AROUND 3-5 DEGREES AMID COLD AIR ADVECTION...WE WILL NOT GET THAT
WARM. THUS MOSTLY SUNNY SKIES EXPECTED TODAY.
BACK TO TEMPS...GIVEN OUR 850MB TEMPS AND THE COOL START AND
ONGOING COLD AIR ADVECTION WILL TREND HIGHS AT OR BELOW MAVMOS.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 225 AM EDT FRI MAY 24 2013
MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE POPS ON SUNDAY
AND SUNDAY NIGHT.
LITTLE CHANGE IS EXPECTED THROUGH SATURDAY NIGHT WITH THE ONGOING
WEATHER. THE PREVIOUSLY MENTIONED LARGE ARE OF HIGH PRESSURE WILL
REMAIN ACROSS THE GREAT LAKES AND INDIANA...CONTINUING TO DOMINATE
TH REGIONS WEATHER...PROVIDING MOSTLY CLEAR...COOL NIGHTS AND
MOSTLY SUNNY AND COOL DAYS.
ECMWF AND GFS CONTINUE TO BUILD A STRONG RIDGE OVER THE PLAINS
STATES ALOFT WITH NORTHWEST FLOW ON THE LEE SIDE OF THE RIDGE
SPILLING INTO INDIANA AND THE OHIO VALLEY. BY SATURDAY...SOME WARM
AIR ADVECTION BEGINS IN SOUTHWEST INDIANA...HOWEVER THE COLD AIR
LOOKS TO REMAIN IN PLACE THROUGH THE DAY AS 850MB TEMPS LOOK TO
HOLD NEAR 5C THROUGH THE DAY. THUS WITH A FEW MORE HIGH AND MID CLOUDS
EXPECTED ON SATURDAY WILL TREND HIGHS CLOSE TO EXPECTED PERSISTENCE.
GFS INDICATES A SHORT WAVE PUSHING THROUGH THE NORTHWEST FLOW ACROSS
INDIANA ON SUNDAY AFTERNOON AS WARM AIR ADVECTION CONTINUES IN THE
LOWER LEVELS. GULF MOISTURE REMAINS CUT OFF AND DEW POINTS LOOK TO
REMAIN IN THE RELATIVELY DRY 40S. GFS 300K ISENTROPIC SURFACE
SHOWS SOME LIFT ACROSS THE AREA ON LATE SUNDAY AFTERNOON AND INTO
SUNDAY NIGHT AS SPECIFIC HUMIDITIES RISE TO NEAR 7G/KG. FORECAST
SOUNDINGS AND TIME HEIGHTS HINT AT MORE MOISTURE AVAILABLE IN THE
COLUMN HOWEVER. THUS CONFIDENCE IN ANY RAIN REMAINS LOW AND WILL
CONTINUE TO CARRY A LOW CHC POP DURING THIS TIME PERIOD. AS FOR
TEMPS WILL CONTINUE TO HOLD VALUES AT OR BELOW MAVMOS GIVEN THE
ADDITIONAL CLOUD COVER EXPECTED ACROSS THE AREA...ALONG WITH THE
LOW PRECIPITATION CHANCES.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 152 AM EDT THU MAY 23 2013
ENSEMBLES IN GOOD AGREEMENT WITH THE LONG WAVE FEATURES DURING THIS
PERIOD. UPPER RIDGE CURRENTLY OVER THE PLAINS IS EXPECTED TO
GRADUALLY SHIFT EAST INTO THE MIDWEST AND OHIO VALLEY BY THE MIDDLE
OF NEXT WEEK. APPEARS THERE IS A POTENTIAL FOR EMBEDDED SHORT WAVE
TROUGHS TO RIDE THROUGH THE RIDGE...AT LEAST ON MONDAY AND TUESDAY.
WILL CONTINUE WITH CHANCE POPS AT THOSE TIMES.
BY NEXT WEDNESDAY AND THURSDAY...ENSEMBLES SUGGEST THE UPPER RIDGE
WILL BUILD MORE AGGRESSIVELY OVER THE AREA AS DEEP TROUGHING DEVELOPS
OVER THE WEST COAST AND ROCKIES. THIS SHOULD HELP TO CAP OFF
PRECIPITATION CHANCES LATER NEXT WEEK...WITH THE ENSEMBLES
SUGGESTING LITTLE THREAT FOR PRECIPITATION AFTER TUESDAY. WILL GO
DRY FOR NEXT WEDNESDAY AND THURSDAY.
&&
.AVIATION /DISCUSSION FOR 240600Z TAF ISSUANCE/...
ISSUED AT 1231 AM EDT FRI MAY 24 2013
POCKETS OF MVFR CEILINGS TO PERSIST AT KBMG AND KIND FOR THE NEXT
FEW HOURS...OTHERWISE VFR CONDITIONS EXPECTED.
STRATOCU DECK CONTINUES TO ERODE FROM THE NORTHWEST...WITH KHUF AND
KLAF NOW MAINLY CLEAR WITH PREDOMINANT CEILING UP TO 3500-4000FT AT
BOTH KBMG AND KIND. RAP DATA INDICATING THAT A N/NE FLOW WILL KEEP
AXIS OF DEEPER MOISTURE THROUGH THE BOUNDARY LAYER ALIGNED ACROSS
THE REGION FOR THE NEXT 3-6 HOURS. CURRENT SATELLITE IMAGERY
SUPPORTS THIS THINKING AS AREA OF LOWER CLOUDS DRIFTING SOUTH ACROSS
NORTHERN INDIANA. WILL KEEP CLOUDS IN AT KBMG AND KIND FOR THE NEXT
FEW HOURS WITH CLEARING THEREAFTER AS DRIER AIR ADVECTS INTO THE
REGION WITH THE HIGH. NORTHERLY WINDS AT 10-15KTS CURRENTLY WILL
DIMINISH TO 5-10KTS LATE.
THE HIGH WILL EXPAND ACROSS THE OHIO VALLEY WITH QUIET WEATHER
TODAY. PRESENCE OF THE DEPARTING LOW LEVEL THERMAL TROUGH INTO THE
AFTERNOON MAY BE JUST ENOUGH TO GENERATE A FEW CU AT KIND.
OTHERWISE...ANTICIPATE CLEAR SKIES AND NORTHERLY WINDS TO NEAR 10KTS
ALL DAY. MAY START TO SEE SOME THIN CIRRUS DRIFT INTO THE REGION
TONIGHT AS IT SPILLS OVER TOP OF THE UPPER RIDGE OVER THE CENTRAL
PLAINS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...PUMA
NEAR TERM...PUMA
SHORT TERM...PUMA
LONG TERM....JAS
AVIATION...RYAN
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1231 AM EDT FRI MAY 24 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 300 PM EDT THU MAY 23 2013
UPPER TROUGH ACROSS THE LOWER GREAT LAKES WILL MOVE SOUTHEAST ACROSS
THE APPALACHIANS ON FRIDAY AS COOL CANADIAN HIGH PRESSURE SETTLES
ACROSS THE GREAT LAKES AND OHIO VALLEY. THIS WILL RESULT IN CLEARING
TONIGHT WITH BELOW TEMPERATURES THROUGH THE MEMORIAL DAY WEEKEND.
SHOWER CHANCES WILL RETURN BY SATURDAY. TEMPERATURES WILL RETURN TO
NEAR NORMAL MEMORIAL DAY AND ABOVE NORMAL BY MIDWEEK NEXT WEEK.
THUNDERSTORM CHANCES WILL ALSO RETURN NEXT WEEK AS GULF MOISTURE
SPREADS NORTH ACROSS THE OHIO VALLEY.
&&
.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 945 PM EDT THU MAY 23 2013
UPDATE...
HUNG ONTO CLOUD COVER A FEW HOURS LONGER THAN ORIGINAL
FORECAST...BUT ANTICIPATE CLEARING TO ACCELERATE AFTER MIDNIGHT AS
HIGH PRESSURE MAKES PUSH INTO FORECAST AREA. THIS WILL RESULT IN
SUBSTANTIAL RADIATIONAL COOLING AND TEMPS DIPPING INTO THE UPPER
30S/LOW 40S. CURRENTLY...TEMPS ACROSS THE AREA ARE IN THE UPPER
40S/LOW 50S. CURRENT RADAR MOSAIC IS SHOWING A FEW LIGHT RETURNS
OVER THE NORTHEAST QUADRANT AS ORIGINALLY EXPECTED...BUT THESE
SHOULD DISSIPATE WITHIN THE NEXT HOUR.
PREVIOUS DISCUSSION...
MAIN CHALLENGES TONIGHT WILL BE TIMING OF END OF SHOWERS...CLEARING
AND FINALLY TEMPERATURES AS AN UPPER LOW DROPS SOUTHEAST ACROSS THE
LOWER GREAT LAKES AND COOL CANADIAN HIGH SURFACE BUILDS IN BEHIND A
COLD FRONT.
MODELS IN GOOD AGREEMENT ON DROPPING AN UPPER TROUGH...ACROSS THE
WESTERN GREAT LAKES THIS AFTERNOON...TO LAKE ERIE BY FRIDAY MORNING.
IN ADDITION...COOL CANADIAN HIGH PRESSURE WILL BUILD IN BEHIND A
COLD FRONT THAT WAS PRESENTLY NEAR AN IND-HUF LINE. THIS WILL ALLOW
CLEARING FROM NORTHWEST TO SOUTHEAST AS WELL AS AN END TO THE
SHOWERS. THE SHOWERS SHOULD ONLY HANG AROUND TIL DARK ACROSS OUR
EASTERN COUNTIES...SO PULLED SLIGHT CHANCE SHOWER POPS AFTER 02Z.
LEANED TOWARD THE COLDER 12Z NAM MOS WHICH WAS BRINGING OVERNIGHT
LOWS IN THE UPPER 30S ACROSS OUR NORTHWEST OVERNIGHT AND 40S
ELSEWHERE. NORTHWEST WINDS WILL DROP TO BELOW 10 KNOTS AT DARK AS
WELL.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
ISSUED AT 300 PM EDT THU MAY 23 2013
MAIN FOCUS TO THE SHORT TERM WILL BE ON POPS FOR THE MEMORIAL DAY
WEEKEND WITH SO MANY OUTDOOR ACTIVITIES ON TAP.
MODELS IN GOOD AGREEMENT ON COOL CANADIAN HIGH PRESSURE...KEEPING
TEMPERATURES BELOW NORMAL THROUGH THE WEEKEND AS UPPER RIDGE CAMPS
OUT ACROSS THE PLAINS. MODEL TIME SECTIONS SUGGEST CLEAR SKIES
FRIDAY AND FRIDAY NIGHT WITH A DRY COLUMN AND HIGH PRESSURE IN
PLACE. HOWEVER...MODELS IN AGREEMENT ON BRINGING QPF TO ALL OR PARTS
OF CENTRAL INDIANA SATURDAY THROUGH SUNDAY AS UPPER WAVES TOP THE
CENTRAL RIDGE AND DROP SOUTHEAST ACROSS CENTRAL INDIANA. IN
ADDITION...305K ISENTROPIC LIFT WILL BE PLACE WITH INCREASING
MOISTURE. THUS...WILL ADD SMALL POPS SATURDAY AND SATURDAY NIGHT
ACROSS ALL BUT NORTHEASTERN PARTS OF THE FORECAST AREA AND RAISE
POPS SLIGHTLY ON SUNDAY WITH GENERALLY CHANCE POPS WEST OF
INTERSTATES 69 AND 65 AND SLIGHT CHANCE POPS EAST. GULF MOISTURE
DOES NOT START INCREASING UNTIL EARLY NEXT WEEK...AND MODEL TIME
SECTIONS ALSO REVEAL DRY AIR BELOW 850 MILLIBARS. SO...AM
COMFORTABLE WITH THE LOWER ALLBLEND POPS. WOULD NOT RULE OUT THUNDER
SUNDAY...BUT BEST INSTABILITY WILL BE WEST OF CENTRAL INDIANA.
ALLBLEND TEMPERATURES RESEMBLE THE CLOSE MOS AND LOOK REASONABLE
WITH THE COOL CANADIAN AIR POISED TO HANG AROUND.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
ISSUED AT 152 AM EDT THU MAY 23 2013
MODELS ARE SIMILAR ENOUGH FOR THE MOST PART THAT THE ALL BLEND
INITIALIZATION WAS USED FOR MOST ITEMS.
A WARM FRONT WILL REMAIN IN THE NEIGHBORHOOD EARLY IN THE
EXTENDED...WHICH WILL ALLOW SOME SHOWERS AND THUNDERSTORMS TO
DEVELOP. LOCATION OF FRONT AND TIMING OF ITS MOVING NORTHEAST
REMAINS SOMEWHAT UNCERTAIN...SO RELUCTANTLY KEPT LOW POPS IN SUNDAY
NIGHT INTO WEDNESDAY /EVEN THOUGH IT LIKELY WILL NOT RAIN EACH
PERIOD/. RIDGING WILL THEN BUILD IN FOR THE END OF THE PERIOD.
TEMPERATURES WILL WARM THROUGH THE PERIOD AS THE FRONT LIFTS
NORTHEAST AND UPPER RIDGING BUILDS IN.
&&
.AVIATION /DISCUSSION FOR 240600Z TAF ISSUANCE/...
ISSUED AT 1231 AM EDT FRI MAY 24 2013
POCKETS OF MVFR CEILINGS TO PERSIST AT KBMG AND KIND FOR THE NEXT
FEW HOURS...OTHERWISE VFR CONDITIONS EXPECTED.
STRATOCU DECK CONTINUES TO ERODE FROM THE NORTHWEST...WITH KHUF AND
KLAF NOW MAINLY CLEAR WITH PREDOMINANT CEILING UP TO 3500-4000FT AT
BOTH KBMG AND KIND. RAP DATA INDICATING THAT A N/NE FLOW WILL KEEP
AXIS OF DEEPER MOISTURE THROUGH THE BOUNDARY LAYER ALIGNED ACROSS
THE REGION FOR THE NEXT 3-6 HOURS. CURRENT SATELLITE IMAGERY
SUPPORTS THIS THINKING AS AREA OF LOWER CLOUDS DRIFTING SOUTH ACROSS
NORTHERN INDIANA. WILL KEEP CLOUDS IN AT KBMG AND KIND FOR THE NEXT
FEW HOURS WITH CLEARING THEREAFTER AS DRIER AIR ADVECTS INTO THE
REGION WITH THE HIGH. NORTHERLY WINDS AT 10-15KTS CURRENTLY WILL
DIMINISH TO 5-10KTS LATE.
THE HIGH WILL EXPAND ACROSS THE OHIO VALLEY WITH QUIET WEATHER
TODAY. PRESENCE OF THE DEPARTING LOW LEVEL THERMAL TROUGH INTO THE
AFTERNOON MAY BE JUST ENOUGH TO GENERATE A FEW CU AT KIND.
OTHERWISE...ANTICIPATE CLEAR SKIES AND NORTHERLY WINDS TO NEAR 10KTS
ALL DAY. MAY START TO SEE SOME THIN CIRRUS DRIFT INTO THE REGION
TONIGHT AS IT SPILLS OVER TOP OF THE UPPER RIDGE OVER THE CENTRAL
PLAINS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...MK/TDUD
SHORT TERM...MK
LONG TERM....50
AVIATION...RYAN
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS TOPEKA KS
347 AM CDT FRI MAY 24 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 347 AM CDT FRI MAY 24 2013
00Z 500MB RAOBS INDICATE RISING HEIGHTS OVER THE CENTRAL CONUS WITH
UPPER TROFS FLANKING A DEVELOPING RIDGE. THE RIDGE AT 700MB WAS OVER
EASTERN KANSAS...WHILE AT 850MB DEWPOINTS RANGED FROM AROUND 3C AT
KTOP AND KOUN TO AROUND 12 AT KDDC...KAMA...AND KFWD. WESTERN KANSAS
RADARS AND OBSERVATIONS INDICATING SOME ISOLATED MID LEVEL
CONVECTION WITH A WEAKENING CONVECTIVE CLUSTER OVER EASTERN COLORADO.
ISENTROPIC LIFT INCREASES AND LOWERS TO AROUND 850MB TODAY AS THE
700MB RIDGE SHIFTS TO THE MISSOURI BORDER. LOW/MID LEVELS SLOWLY
SATURATE...AND THERE MAY BE ENOUGH LIFT FOR ISOLATED TO SCATTERED
ELEVATED STORMS BY SUNRISE AND CONTINUING THROUGH MUCH OF THE DAY.
CHANCES SHOULD BE LIMITED TO THE WESTERN PORTIONS OF THE COUNTY
WARNING AREA WITH THE MID LEVEL RIDGE STILL IN PLACE. SOME WEAKENING
IN THE WAA OCCURS IN THE AFTERNOON AND COULD LEAD TO A DOWNWARD
TREND...BUT A STRONGER LOW LEVEL JET IN AN INCREASINGLY MOIST
TROPOSPHERE SUGGESTS SOME CHANCE FOR CONVECTION INCREASING AND
SPREADING ACROSS KANSAS TONIGHT. THERE IS NOT MUCH OF A FOCUSING
MECHANISM TO POINT TO ANY PARTICULAR LOCATIONS IN THE REGION FOR
BETTER PRECIP CHANCES...BUT KEPT LARGEST CHANCES IN THE NORTH AND
WEST WHERE SLIGHTLY BETTER MOISTURE ADVECTION AND PRECIPITABLE WATER
SHOULD RESIDE. SOUTHEAST WINDS WILL INCREASE MORE THAN RECENT DAYS
BY LATE THIS MORNING AS LEE LOW PRESSURE DEEPENS...WITH THE BETTER
MIXING AND MODEST LOW LEVEL WAA RESULTING IN SLIGHTLY WARMER HIGHS.
LOWS TONIGHT WILL BE SEVERAL DEGREES WARMER IN THE MORE MOIST AND
INSULATED AIRMASS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 347 AM CDT FRI MAY 24 2013
THE WEEKEND PATTERN WILL BE CHARACTERIZED BY TROUGHS IN THE WEST AND
EAST WITH A RIDGE OVER THE CENTRAL PLAINS THIS PATTERN REMAINS INTO
MONDAY BEFORE THE RIDGE MOVES OFF TO THE EAST BY WEDNESDAY. SEVERAL
PIECES OF ENERGY WILL MOVE OUT OF THE WESTERN TROUGH FROM SATURDAY
THROUGH NEXT WEDNESDAY....HOWEVER THE UPPER TROUGH WILL MOVE OUT
INTO THE EASTERN ROCKIES BY FRIDAY. THIS WILL PROVIDE NUMEROUS
CHANCES FOR THUNDERSTORMS THROUGH THE PERIOD. THE TIMING OF THE
WAVES EMANATING OUT OF THE WESTERN TROUGH IS HARD TO CALL AT THIS
TIME. ALSO ANY MESOSCALE BOUNDARIES LEFT OVER FROM DECAYING
OVERNIGHT CONVECTION WILL PROVIDE A FOCUS FOR LATER DEVELOPMENT.
MOISTURE WILL MOVE BACK INTO CENTRAL AND EASTERN KANSAS AS THE LOW
LEVEL JET BECOMES SOUTH TO SOUTHWEST OVER CENTRAL AND EASTERN
KANSAS. A THETA-E RIDGE WILL STRETCH ACROSS NORTH CENTRAL AND
NORTHEAST KANSAS THROUGH MUCH OF THE NEXT WEEK. CONVECTION IS
EXPECTED TO DEVELOP IN THE WESTERN HIGH PLAINS AND INTO CENTRAL AND
EASTERN NEBRASKA SATURDAY NIGHT WITH ISENTROPIC LIFT OVER A FRONTAL
BOUNDARY NEAR THE NEBRASKA BORDER. HIGHEST CHANCES WILL REMAIN
FOCUSED NORTH. AGAIN ANY OLD OUTFLOW BOUNDARY ACROSS THE CWA COULD
BE A FOCUS FOR AFTERNOON CONVECTION AS MCS/S MOVE ACROSS NEBRASKA
AND NORTHERN KANSAS ON SUNDAY. INSTABILITY COULD BE AS HIGH AS 3000
J/KG TO 4800 J/KG MUCAPE ACROSS THE CWA. DEEP LAYER SHEAR AROUND 30
KTS SUNDAY AFTERNOON. MOISTURE TRANSPORT VECTORS INCREASE ACROSS
CENTRAL KANSAS INTO SOUTHEAST NEBRASKA THROUGH THE DAY. PRECIPITABLE
WATER VALUES INCREASE TO AROUND 1.5 INCHES. LOCALLY HEAVY RAINFALL
IS POSSIBLE WITH ANY CONVECTION SUNDAY AND SUNDAY NIGHT.
CONTINUED CHANCES FOR NOCTURNAL CONVECTION WILL CONTINUE THROUGH THE
BULK OF THE WEEK WITH MORE WIDELY SCATTERED ACTIVITY IN THE
AFTERNOON AND EVENING HOURS. IF THUNDERSTORMS CONTINUE TO MOVE OVER
THE SAME AREAS DURING THE WEEK COULD SEE SOME FLOOD/FLASH FLOODING.
HIGHS WILL BE IN THE 80S THROUGH THE MONDAY THROUGH THURSDAY PERIOD
WITH LOWS IN THE 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1145 PM CDT THU MAY 23 2013
MODELS CONTINUE TO SHOW INCREASING MOISTURE ADVECTION UP THROUGH
CENTRAL KS AS THE LOW LEVEL JET VEERS AROUND MORE TO THE SOUTH.
LATEST SATELLITE SHOWS A BAND OF AC WITHIN THE AXIS OF MOISTURE
ADVECTION. THEREFORE WILL CONTINUE WITH A MENTION OF VCSH AT MHK
BY MID MORNING AS ISENTROPIC PROGS SHOW SOME LIFT WITH LOWERING
COND PRES DEF DEVELOPING ACROSS NORTH CENTRAL KS. THINK TOP AND FOE
WILL REMAIN MAINLY TO THE EAST OF THE BETTER MOISTURE ADVECTION.
THE NAM HAS BACKED OFF ON THE LOW LEVEL SATURATION AND MVFR CIGS.
WITH THE RUC SHOWING SOME CONSISTENCY IN KEEPING CIGS VFR...HAVE
TAKEN OUT THE MENTION OF MVFR CIGS AT MHK.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...65
LONG TERM...53
AVIATION...WOLTERS
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1145 PM CDT THU MAY 23 2013
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 341 PM CDT THU MAY 23 2013
ALTHOUGH THE SURFACE LOW THAT IMPACTED THE REGION THIS PAST WEEKEND
HAS PROGRESSED EAST OF THE GREAT LAKES REGION...AN ASSOCIATED COLD
FRONT STILL STRETCHED WESTWARD ACROSS NORTHERN MISSOURI AND INTO
EASTERN NEBRASKA. ENOUGH MOISTURE AND LIFT WAS PRESENT NEAR THIS
BOUNDARY TO KEEP MUCH OF NORTHEASTERN KANSAS UNDER CLOUD COVER
THROUGH MUCH OF THE DAY TODAY. VISIBLE SATELLITE IMAGERY SHOWED
SOME SCATTERING OUT WITH THE CLOUD COVER BY MID AFTERNOON...WHICH
ALLOWED AFTERNOON TEMPERATURES TO REACH INTO THE UPPER 60S TO LOWER
70S.
SURFACE HIGH PRESSURE OVER THE NORTHERN PLAINS HAS SPILLED SOUTHWARD
INTO THE CENTRAL PLAINS TODAY AND WILL SHIFT EAST OF THE AREA
TONIGHT INTO FRIDAY AS THE UPPER LEVEL RIDGE CONTINUES TO BUILD OVER
THE CENTRAL AND SOUTHERN PLAINS. EXPECT ANOTHER COOLER NIGHT ACROSS
THE CWA THIS EVENING AS OVERNIGHT LOWS LOOK TO DROP INTO THE
UPPER 40S TO LOWER 50S. MODELS CONTINUE TO SHOW SEVERAL EMBEDDED
SHORTWAVES DEVELOPING ALONG THE NORTHERN EXTENT OF THIS RIDGE OVER
THE UPCOMING DAYS...THE FIRST LOOKING TO DEVELOP TONIGHT INTO FRIDAY
ACROSS EASTERN COLORADO AND WESTERN KANSAS. THIS SHORTWAVE ALSO
LOOKS TO COINCIDE WITH A FRONTAL BOUNDARY STRETCHING SOUTHWARD FROM
A SURFACE LOW OVER MONTANA INTO WESTERN NEBRASKA AND WESTERN KANSAS.
BETTER CHANCES FOR PRECIPITATION LOOK TO BE ACROSS THE WESTERN HALF
OF KANSAS IN THE VICINITY OF THIS BOUNDARY AND SHORTWAVE. THERE IS
STILL SOME UNCERTAINTY AMONGST THE MODELS REGARDING HOW MUCH
MOISTURE AND LIFT WILL BE ABLE TO SPREAD EASTWARD INTO THE FORECAST
AREA ON FRIDAY TO SUPPORT THE DEVELOPMENT OF SOME SCATTERED SHOWERS
AND THUNDERSTORMS. DUE TO THIS UNCERTAINTY...HAVE CHANCE POPS
PRIMARILY FOCUSED OVER NORTH CENTRAL AND CENTRAL KANSAS THROUGH THE
DAY WITH A MOSTLY DRY FORECAST FOR FAR EASTERN KANSAS. COULD START
SEEING ANY SCATTERED PRECIPITATION THAT DEVELOPS SHIFT INTO
NORTHEASTERN KANSAS BY FRIDAY EVENING AS THE SHORTWAVE PIVOTS A BIT
FURTHER EAST ALONG THE RIDGE. THE INCREASED CLOUD COVER ACROSS THE
AREA ON FRIDAY WILL KEEP TEMPERATURES ON THE COOLER SIDE ONCE
AGAIN...WITH AFTERNOON HIGHS LOOKING TO TOP OUT IN THE UPPER 60S TO
LOWER 70S.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 341 PM CDT THU MAY 23 2013
THE MID AND LONG TERM FORECAST PERIOD REMAINS RATHER UNCERTAIN
REGARDING SPECIFIC DETAILS OF LOCATION AND TIMING OF THUNDERSTORM
POTENTIAL...BUT CONFIDENT IN SOME OF THE GENERAL FEATURES AS WELL AS
A TEMPERATURE PATTERN.
THE UPPER LEVEL FLOW PATTERN THIS WEEKEND WILL ACTUALLY BE
CHARACTERIZED BY A RATHER SHARP RIDGE AXIS CENTERED OVER EASTERN
KANSAS WITH A LONG WAVE TROUGH FIRMLY IN PLACE OVER THE WESTERN
CONUS. SEVERAL PIECES OF ENERGY WILL TRANSLATE OUT OF THE WESTERN
TROUGH FROM SATURDAY THROUGH NEXT WEEK...PROVIDING NUMEROUS CHANCES
FOR THUNDERSTORMS THROUGH THE PERIOD. THE PRIMARY CHALLENGE WITH
THIS FORECAST SEEMS TO BE IN INTERPRETING WHICH OF THESE IMPULSES
WILL BE STRONG ENOUGH TO OVERCOME A CAPPING INVERSION ACROSS EASTERN
KANSAS...AS WELL AS ANY PERIODS DURING WHICH THE DEEP LAYER SHEAR
MARKEDLY INCREASES COINCIDENT WITH THE SHORT WAVE TROUGH PASSAGE.
OTHERWISE...TEMPERATURES ARE EXPECTED TO BE GENERALLY IN THE 80S FOR
HIGHS AND 60S FOR LOWS THROUGH THE ENTIRE PERIOD...WITH CLOUD COVER
LARGELY DEPENDENT UPON CONVECTIVE SYSTEMS...AND A RATHER MOIST LOW
LEVEL AIRMASS IN PLACE.
IN TERMS OF SPECIFICS...IT WOULD APPEAR THAT A SHORT WAVE TROUGH
PASSAGE WILL WEAKEN THE UPPER RIDGE ENOUGH ON FRIDAY NIGHT TO
SUPPORT AN MCS ACROSS NEBRASKA...AND PERHAPS EVEN INTO NORTHERN
KANSAS. THE REMNANTS OF THIS MCS MAY IMPACT MAINLY NORTHEAST KANSAS
ON SATURDAY MORNING...BUT PERHAPS MORE IMPORTANTLY ARE EXPECTED TO
PLACE AN OUTFLOW BOUNDARY ACROSS THE FORECAST AREA BY AFTERNOON. THE
EXACT LOCATION OF ANY OUTFLOW WILL FOCUS ANY THUNDERSTORM ACTIVITY
INITIALLY TO THAT LOCATION AND REMAINS UNCERTAIN...BUT INSTABILITY
WILL BE MAXIMIZED ALONG THE BOUNDARY WITH INHIBITION MINIMIZED AND
EXPECT AT LEAST A FEW STORMS TO DEVELOP ALONG ANY REMNANT OUTFLOW IF
IT DOES INDEED EXIST. THE DEEP LAYER SHEAR PROFILE IS NOT PARTICULARLY
STRONG ALTHOUGH IT MAY SUPPORT AT LEAST SOME BRIEF STORM
ORGANIZATION BEFORE COLD POOLS INTERACT. SATURDAY NIGHT CONVECTION
MAY ALSO TRACK ALONG THIS BOUNDARY ACROSS THE AREA OUT OF CENTRAL
NEBRASKA. WILL NEED TO MONITOR THIS ACTIVITY FOR LATE NIGHT
WIND/HAIL POTENTIAL SHOULD IT ORGANIZE INTO AN MCS. UPPER RIDGING IS
FORECAST TO BUILD BACK IN OVER CENTRAL KANSAS IN THE WAKE OF THIS
ACTIVITY...WITH ANY SUNDAY AFTERNOON CONVECTIVE POTENTIAL DEPENDING
UPON A CAP BREAK. INSTABILITY SHOULD STILL BE STRONG ON SUNDAY AND
THE DEEP SHEAR PROFILE SHOULD BE A BIT MORE IMPRESSIVE THAN
SATURDAY...AND COULD SEE SOME SEVERE WEATHER POTENTIAL LATE SUNDAY
INTO SUNDAY NIGHT. LOCALLY HEAVY RAINFALL WILL ALSO BE POSSIBLE
THROUGH THIS PERIOD GIVEN MODERATE TO HIGH PWAT VALUES AND POTENTIAL
FOR STORMS TO FOCUS REPEATEDLY OVER THE SAME GENERAL AREAS.
BEYOND SUNDAY...THE UNCERTAINTY REGARDING SPECIFICS IS JUST TOO
GREAT TO GET BOGGED DOWN IN ANY DETAILS. OPERATIONAL MODELS MAINTAIN
THE BROAD SOUTHWESTERLY UPPER FLOW PATTERN BUT DIVERGE REGARDING THE
EVOLUTION OF THE EJECTION DATE OF THE PRIMARY UPPER LOW ITSELF.
WHENEVER THE HEART OF THIS SYSTEM DOES ENTER THE CENTRAL PLAINS...
WOULD EXPECT A GREATER POTENTIAL OF SEVERE WEATHER WITH INCREASED
DEEP LAYER SHEAR AND PERHAPS A MORE ORGANIZED FOCUS FOR DEVELOPMENT.
HAVE MAINTAINED SEVERAL RATHER SMALL CHANCES FOR PRECIPITATION
THROUGH THE LONG TERM PERIOD BUT THERE IS A CHANCE THAT MUCH OF THE
AREA COULD BE DRY UNTIL THE MAIN TROUGH APPROACHES...IT ALL REALLY
DEPENDS ON WHETHER CAP STRENGTH CAN OUTLAST WEAK SHORT WAVE TROUGH
STRENGTH ON A DAY TO DAY BASIS. EVEN AFTER THE MAIN TROUGH CROSSES
THE PLAINS...IT LOOKS LIKE THE WEATHER PATTERN WILL REMAIN ACTIVE
WITH SOUTHWEST FLOW REMAINING IN PLACE AND A NEW LONG WAVE TROUGH
SETTLING OVER THE WESTERN U.S.
BARJENBRUCH
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1145 PM CDT THU MAY 23 2013
MODELS CONTINUE TO SHOW INCREASING MOISTURE ADVECTION UP THROUGH
CENTRAL KS AS THE LOW LEVEL JET VEERS AROUND MORE TO THE SOUTH.
LATEST SATELLITE SHOWS A BAND OF AC WITHIN THE AXIS OF MOISTURE
ADVECTION. THEREFORE WILL CONTINUE WITH A MENTION OF VCSH AT MHK
BY MID MORNING AS ISENTROPIC PROGS SHOW SOME LIFT WITH LOWERING
COND PRES DEF DEVELOPING ACROSS NORTH CENTRAL KS. THINK TOP AND FOE
WILL REMAIN MAINLY TO THE EAST OF THE BETTER MOISTURE ADVECTION.
THE NAM HAS BACKED OFF ON THE LOW LEVEL SATURATION AND MVFR CIGS.
WITH THE RUC SHOWING SOME CONSISTENCY IN KEEPING CIGS VFR...HAVE
TAKEN OUT THE MENTION OF MVFR CIGS AT MHK.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...HENNECKE
LONG TERM...BARJENBRUCH
AVIATION...WOLTERS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
326 AM EDT FRI MAY 24 2013
.Short Term (Now - Saturday)...
Issued at 325 AM EDT Fri May 24 2013
Surface cold front continues to plow on off to the southeast this
morning. Rain showers have long ended across southern Indiana and
central Kentucky, but plenty of low clouds remain in place across
the region. Drier air is trying to work in from the west, but a
persistent north to northeasterly PBL flow is allowing the low
clouds to continue to flow southward this morning. In the near
term, expect mostly cloudy conditions to remain in place, though our
western sections will probably see a little more clearing due to the
closer proximity to the drier air in place to our west.
Temperatures will continue to fall with cold air advection
place...and we expect readings to fall into the mid-upper 40s by
sunrise.
For today, high pressure will slowly build in from the northwest.
Dry punch of air will continue to make headway into the Ohio Valley,
so we should see a rapid decrease in clouds during the morning hours
with mostly sunny skies expected today. Dewpoints will likely drop
into the 30s this afternoon and with a good amount of mixing and
cooler air aloft, we`re likely to see a bit of a temperature
gradient across the region. Afternoon highs will likely only top
out in the 61-66 degree range across the Bluegrass region of central
Kentucky with 65 to 70 degree readings in the I-65 corridor and
points west. Surface winds will be out of the N to NE and will
slacken later in the afternoon and into the evening hours.
For tonight, high pressure and light winds will be in place which
should set up a good radiational cooling period. The question
remains whether we`ll see the development of fog or a potential
frost. From a climatological perspective, the threat of frost is
fairly low here in KY/IN. For the most part, it looks like
temperatures will probably remain warm enough that we`ll see mostly
patchy fog develop. However, some of our eastern counties may get a
touch of frost...especially in our typical cold spots. For this
reason, we will issue a special weather statement this morning
highlighting the potential frost threat in the typical colder spots
in the eastern Bluegrass region. Lows tonight will likely be in the
upper 30s in the east with lower 40s in the central and western
sections.
Quiet and warmer conditions are expected for Saturday as high
pressure moves on off to the east. This should kick our surface
winds around to the south and eventually the southwest.
Temperatures should moderate a bit on Saturday with highs in the
65-70 degree range in the Bluegrass with 70 to 75 in the central and
western sections of the forecast area.
.Long Term (Saturday Night through Thursday)...
Issued at 310 AM EDT Fri May 24 2013
A amplified yet slowly progressive 500mb pattern will feature deep
troughs across New England and the Pacific Northwest late Saturday.
Eventually, ridging over the western plains will expand towards the
Lower Ohio Valley. This will enable temperatures to warm
substantially beginning Monday. High temperatures may actually
approach 90 towards the end of the next work week.
Canadian high pressure ridge axis will lie right over the Great
Lakes late Saturday, extending southward across the Commonwealth.
Cool weather with low dewpoints will continue through Sunday, along
with light winds. Despite the possibility of some increasing high
cloudiness associated with a warm front to our southwest, lows early
Sunday will fall well down into the lower to mid 50s.
Quite a bit of uncertainty and disagreement exists between some of
the long range guidance for the Sunday through Tuesday time frame.
Overall, warmer more moist air will attempt to move northeast into
the Lower Ohio Valley. However, a deep slow moving low over New
England and persistent northwest flow aloft over the Commonwealth
will retard the northeast progress of this boundary. It is likely
during the first couple of days of next week that several convective
clusters will develop across the midwest, aided by moisture
advection and the presence of a nocturnal low level jet. These
periodic thunderstorms may slide southeast, bringing at least a
chance of difficult-to-time thunderstorms beginning Sunday afternoon
and possibly continuing through Tuesday.
Both the ECMWF and the GFS forecast the surface boundary to stretch
early Sunday from northern Missouri southeast towards central
Tennessee. The consistent ECMWF has been slower in bringing this
boundary north across the Commonwealth than the GFS. However, by
Tuesday afternoon, both of these models have this boundary as far
north as southern Ohio. Will continue our forecast of at least a
chance of thunderstorms Sunday afternoon through Tuesday, with an
admittedly low confidence on attempting to time any areas of
convection moving southeastward along this boundary.
Highs on Sunday will likely remain in the 70s, warming to the lower
to mid 80s by Tuesday. For Wednesday and Thursday, mid-summer like
ridging will develop over the Tennessee Valley. Expect that these
two days will stay dry with quite warm temperatures in the mid to
upper 80s.
&&
.Aviation (06Z TAF Issuance)...
Issued at 115 AM EDT Fri May 24 2013
MVFR ceilings are expected to persist at the terminals through the
overnight period. Previous thinking from earlier was for clouds to
clear out in the 07-09Z time frame. However, latest trajectory data
from the RAP and LMK local WRF model suggests that the low-level PBL
will be more northerly to a little northeasterly overnight. IR
satellite imagery suggests that this may be correct as cloud cover
has not really eroded all that much to our north and more clouds up
over northern Indiana are heading southward. Upstream observations
show that ceilings are holding around 2kft AGL and we expect these
conditions to continue through much of the overnight period. Feel
that ceilings will eventually mix out and go back to VFR by around
24/11Z or so and then continue throughout the day. Surface winds
for the next few hours will remain out of the NNW to N at 10-13kts
with occasional gusts up to 15-18kts. Winds look to shift to the
northeast during the daylight hours and then diminish near toward
the end of the TAF period.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Short Term.......MJ
Long Term........JSD
Aviation.........MJ
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
117 AM EDT FRI MAY 24 2013
...Updated Aviation Discussion...
.Forecast Update...
Issued at 115 AM EDT Fri May 24 2013
Current forecast still pretty much on track. Will be make a few
changes to the cloud grids as sky cover will likely remain mostly
cloudy for a good portion of the night. Latest RAP and LMK WRF data
showing more of a north to north-northeast low level PBL flow which
should keep clouds in here a little longer than previously
forecast. This will keep temperatures from dropping as fast as
previously thought. So will also make some minor adjustments there
as well.
Update issued at 1210 AM EDT Fri May 24 2013
Radar and surface observations show that rain showers have been
diminishing quite rapidly across the region as the secondary surface
cold pushes southward through the region. Latest 11-3.9 micron
satellite imagery shows deck of low clouds across the forecast area
and extends back into central Indiana. Based on satellite imagery,
back edge of clouds look to clear the Ohio River around 3AM EDT and
then clear much of southern Kentucky by sunrise. Have updated the
forecast based on those cloud trends and also have removed PoPs from
most areas. Temperatures with the new airmass coming in are quite
cool for mid-late May. Readings have cooled into the lower 50s
across our far northern areas and have dropped into the mid-upper
50s across northern Kentucky. Based on the short-term consensus
model runs, looks like min temperatures will cool into the lower 40s
across southern Indiana with upper 40s across Kentucky by sunrise.
Winds will remain out of the NNW to N at 10 to 15 mph.
&&
.Short Term (Now - Friday Night)...
Issued at 300 PM EDT Thu May 23 2013
A deep trough over the Great Lakes is currently pivoting, with the
axis on track to pass over the forecast area this evening and
tonight. At the surface, a cold front is dropping southeastward
through central Indiana. This front is forecast to exit our
southeast forecast area by about midnight tonight. Scattered showers
are developing along and ahead of the front. This will continue
across our area the rest of this afternoon and into the evening
hours. Surface-based instability is rather weak and these showers
are capped at or just above the freezing level. Could see an
isolated thunderstorm, but chances are rather low. Activity will
dissipate late this evening and clouds will slowly diminish from
northwest to southeast overnight.
Winds will become northwesterly with the frontal passage, then
northerly by daybreak Friday. Dry and much cooler air will begin to
work into the region from the northwest, with temperatures dropping
into the middle and upper 40s tonight. Despite almost unlimited sun
on Friday, temperatures will be rather cool, ranging from the middle
60s to around 70 degrees. High pressure will build directly overhead
Friday night. Clear skies and light winds will provide for quite
chilly conditions, with lows bottoming out in the upper 30s and
lower 40s. Typically cooler valleys could drop into the middle 30s.
.Long Term (Saturday through Thursday)...
Issued at 310 PM EDT Thu May 23 2013
High confidence forecast for Saturday with a 1030mb surface high
over Lake Michigan, and extending south into the Ohio Valley. Expect
plenty of sunshine and below-normal temps. Given forecast soundings,
low-level thicknesses, and typical behavior in NE low-level flow,
believe that GFS MOS temps are too warm. Have leaned more toward the
cooler NAM MOS, with highs ranging from the upper 60s over the
Bluegrass to the mid 70s near Bowling Green.
Confidence heads downhill quickly beginning on Saturday night thanks
to NW flow aloft and divergent model solutions. There is consensus
that a NW-SE oriented surface boundary will develop somewhere across
the Ohio and/or Tennessee Valleys. However, the GFS leans more
toward a warm front developing over the Ohio Valley and lifting
north by Monday night, while the ECMWF has the front to our south
initially and not lifting out of the Ohio Valley until Wed/Thu. With
a shortwave ridge axis over the Plains, there is at least a decent
chance that MCSs will develop west of the Mississippi and roll SE
along the front. Confidence is limited by the difficulty in timing
the development of these complexes, and determining whether they
will hold together as they move into what will be a less favorable
environment. Therefore we will generally advertise slight chance
POPs, only bumping up to a 30 POP west of I-65 for Monday. Temp
forecast will undercut the GFS MOS as we do not believe the warm
front will lift northward that quickly. Will stay below normal
through Monday.
Upper ridging will build from the southern Plains beginning on
Tuesday and continue through at least Thursday. Expect temps
trending back above normal for late May, and will continue diurnal
slight chance POPs. Greatest bust potential will be from southern
Indiana into the Bluegrass, where the cooler and wetter pattern
could persist an additional day or two if the warm front is slower to
lift out.
&&
.Aviation (06Z TAF Issuance)...
Issued at 115 AM EDT Fri May 24 2013
MVFR ceilings are expected to persist at the terminals through the
overnight period. Previous thinking from earlier was for clouds to
clear out in the 07-09Z time frame. However, latest trajectory data
from the RAP and LMK local WRF model suggests that the low-level PBL
will be more northerly to a little northeasterly overnight. IR
satellite imagery suggests that this may be correct as cloud cover
has not really eroded all that much to our north and more clouds up
over northern Indiana are heading southward. Upstream observations
show that ceilings are holding around 2kft AGL and we expect these
conditions to continue through much of the overnight period. Feel
that ceilings will eventually mix out and go back to VFR by around
24/11Z or so and then continue throughout the day. Surface winds
for the next few hours will remain out of the NNW to N at 10-13kts
with occasional gusts up to 15-18kts. Winds look to shift to the
northeast during the daylight hours and then diminish near toward
the end of the TAF period.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........MJ
Short Term.......MJP
Long Term........RAS
Aviation.........MJ
AREA FORECAST DISCUSSION
NWS GRAY ME
1218 AM EDT FRI MAY 24 2013
.SYNOPSIS...
A COLD FRONT WILL SLOWLY CROSS THE REGION TONIGHT WILL STALL OFF
THE COAST ON FRIDAY. LOW PRESSURE WILL DEVELOP ON THE FRONT SOUTH
OF CAPE COD FRIDAY NIGHT AND SLOWLY MOVE NORTH THROUGH THE GULF OF
MAINE THROUGH SUNDAY MORNING. LOW PRESSURE WILL CONTINUE NORTH
THROUGH THE MARITIMES SUNDAY NIGHT. HIGH PRESSURE WILL BUILD IN
FROM THE WEST MONDAY AND WILL SHIFT OFFSHORE ON TUESDAY. A WARM
FRONT WILL APPROACH FROM THE SOUTHWEST ON WEDNESDAY.
&&
.NEAR TERM /UNTIL 9 AM THIS MORNING/...
1205 AM...JUST A QUICK UPDATE TO ADJUST POPS AND TEMPS A BIT
OVERNIGHT...AND TO FOCUS ON BEST CH OF HEAVIER DOWNPOURS IN THE
06-13Z TIME FRAME AS 500 MB SH COMBINES WITH MID-LVL JET AND HIGH
PWATS...APPROACHING 200% OF NORMAL COM TO TOGETHER TO PRODUCE A
SURGE OF HEAVY RAINFALL...WHICH WILL DEVELOP AFTER MIDNIGHT AND LKLY
AFFECT MORNING COMMUTE. 00Z NAM12 AND LATEST HRRR FOCUS THE BULK
OF THE PRECIP CLOSER TO THE COAST...WHERE THE GROUND CAN HANDLE IT
BETTER. HOWEVER...COULD CAUSE SOME LOCALIZED PROBLEMS...PONDING ON
THE ROADS AND IN URBAN AREAS.
UPDATE...
HAVE UPDATED GRIDS BASED ON CURRENT CONDITIONS. RADAR CONTS TO
SHOW AREAS OF SHOWERS AND ISOLD TSTMS OVER THE NRN MTNS WHERE WE
HAVE ISSUED AN AREAL FLOOD ADVISORY. OVER SRN NH...THE ECHOES CONT TO
WEAKEN AS THEY HEAD NORTH...DESPITE A PRECIPITABLE WATER LEVEL
AXIS OF 1.6" OVER THE REGION.
LATEST HRRR RUN CONTS TO SHOW PCPN STREAMING IN FROM THE SOUTH
OVERNIGHT...ALONG AND AHEAD OF APPROACHING COLD FRONT. CATEGORICAL
POPS WILL REMAIN IN THE GRIDS OVERNIGHT WITH PATCHY/AREAS OF FOG.
EXPECT AROUND AN INCH OR SO OF RAINFALL OVER THE COASTAL AREAS
WHICH REMAINS WELL BELOW FLASH FLOOD GUIDANCE.
PREV DISC...
COLD FRONT APPROACHING FROM THE WEST WILL MAKE FOR A WET AND
BREEZY NIGHT ACROSS THE REGION. SCATTERED SHOWERS AND SOME
THUNDERSTORMS WILL GRADUALLY CHANGE TO A WIDESPREAD RAIN OVERNIGHT
AS THE FRONT SLOWLY CROSSES THE AREA. EXPECT THUNDERSTORM ACTIVITY
TO BE MAINLY CONFINED TO NEW HAMPSHIRE LATE THIS AFTERNOON AND
THIS EVENING AS MARINE LAYER PERSISTS ACROSS MOST OF MAINE. CAN`T
RULE OUT A RUMBLE OF THUNDER OVERNIGHT BUT SHOULD BE ISOLATED AND
HAVE NOT INCLUDED THIS IN THE FORECAST AFTER THIS EVENING. EXPECT
OVERNIGHT LOWS TO BE UNIFORM ACROSS THE REGION WITH MOST AREAS
DIPPING INTO THE MID 50S TO NEAR 60.
&&
.SHORT TERM /9 AM THIS MORNING THROUGH 6 PM SATURDAY/...
FRONT WILL STALL JUST OFF THE COAST ON FRIDAY WITH RAIN CONTINUING
THROUGH THE DAY ACROSS THE FORECAST AREA. NOT EXPECTING
TEMPERATURES TO MOVE MUCH FROM OVERNIGHT LOWS WITH MOST LOCATIONS
ONLY REACHING THE UPPER 50S TO LOWER 60S. RAIN CONTINUES FRIDAY
NIGHT AS LOW PRESSURE TRACKS NORTH ALONG THE FRONT. FOCUS WILL
TURN TO AREA RIVERS IN NORTHERN ZONES WHERE STORM TOTALS COULD
WILL FALL IN THE THE 2 TO 4 INCH RANGE BY LATE ON SUNDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
CUTOFF AND SFC LOW WILL DRIFT SLOWLY NE THRU THE WEEKEND
CONTINUING PRCP ACROSS THE FCST AREA WITH THE POTENTIAL FOR HEAVY
RAINFALL. MODELS SHOWING MAX QPF ACROSS THE N/MT ZONES TO WRN NH
ZONES. GFS MUCH HIGHER ON QPF...WITH OTHER MODELS PREFERRED. USED
HPC QPF FOR A COMPROMISE. CUTOFF AND SFC LOWS MOVE NE OF THE AREA
MONDAY WITH IMPROVING WX...BUT STILL COOL AIR AND CYCLONIC FLOW
ALOFT ALONG WITH FAIRLY AMPLE RH COULD PRODUCE SOME CLOUDS AND
PSBL -SHRA EVEN ON MONDAY. FOR NOW WILL GO WITH SLGT CHC.
AN UPR LVL AND SFC RIDGE BUILD IN TUESDAY FINALLY BRINGING DRY WX
WITH WARMING TEMPS. AN UPR LVL SHORT WAVE TROF SLIDES E THRU THE
UPR LVL RIDGE LATE WEDNESDAY AND WEDNESDAY NGT...BRINGING ISOLD TO
SCT SHRA TO THE REGION WEDNESDAY NGT AND THURSDAY.
GENERALLY USED BLEND OF GFS40/NAM, MET/MAV & HPC QPF FOR DAYS 4
AND 5 THEN A BLEND OF GFS40, GMOS, MEX/ECE FOR THE REST OF THE
LONG TERM FCST.
&&
.AVIATION /04Z FRIDAY THROUGH TUESDAY/...
SHORT TERM...IFR/LIFR CEILINGS/VSBY TONIGHT THROUGH FRIDAY.
LONG TERM /SATURDAY THROUGH TUESDAY/...IFR/LIFR SATURDAY THRU MUCH
OF SUNDAY...IMPROVING TO VFR WITH PSBL MVFR ON MONDAY THEN VFR
TUESDAY.
&&
.MARINE...
SHORT TERM...SCA IN EFFECT THROUGH FRIDAY TONIGHT.
LONG TERM /SATURDAY THROUGH TUESDAY/...NE WINDS AHEAD OF
APPROACHING LOW AND SEAS LIKELY AT SCA LEVELS SATURDAY AND MAY
NEED TO EXTEND THE SCA THRU THE DAY. WINDS LET UP AND BACK TO THE
NW SLOWLY SATURDAY NGT THRU MONDAY...LIKELY DROPPING BELOW SCA
LEVELS BY LATE SATURDAY NGT OR EARLY SUNDAY. SEAS WILL BE SLOWER
TO DROP OFF. HIGH PRES PROVIDES RELATIVELY CALMER WINDS AND SEAS
ON TUESDAY.
&&
.FIRE WEATHER...
NO PROBLEMS NOTED.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT SATURDAY FOR ANZ150>154.
&&
$$
SYNOPSIS...
NEAR TERM...CEMPA
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
FIRE WEATHER...
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
340 AM EDT FRI MAY 24 2013
.SHORT TERM...TODAY AND TONIGHT
THE WEATHER UP FOR DISCUSSION IS THE PROSPECTS FOR OVERCAST SKIES
TODAY AS AN OPAQUE BLANKET OF 030-035 FT STRATUS IS AGGRESSIVELY
DIVING SOUTHWARD ACROSS LAKE HURON. TRAJECTORY OF CLOUD DECK IN
ADDITION TO THE ORIENTATION OF THE WESTERN EDGE ALIGNS WELL WITH THE
AXIS OF MAXIMUM 925-850MB COLD AIR ADVECTION AND THE DEPRESSION OF
THE LONGWAVE TROUGH AXIS. NWP DATA IS VIRTUALLY VOID OF CLOUD...A
RESULT OF INADEQUATE VERTICAL RESOLUTION WITHIN THE MODELS. WHILE
THE CLOUD IS COMPLETELY OPAQUE IT IS UNDOUBTEDLY A SHALLOW LAYER OF
MOISTURE THAT IS LIKELY TRAPPED WITHIN THE BASE OF THE INVERSION
AT/AROUND 900-890MB. RUC SOUNDINGS SHOW SATURATION AT THIS
ZONE...BUT THE SOUNDING STRUCTURE ITSELF DOES NOT INSPIRE MUCH
CONFIDENCE AS IT IS THE WRONG PROFILE. GIVEN THE TRUE NORTHERLY
TRAJECTORY...HAVE DECIDED TO INTRODUCE OVERCAST CONDITIONS FOR MUCH
OF THE CWA THROUGH THE MORNING HOURS. IT WILL BE DIFFICULT TO
PINPOINT ANY WEST EDGE OF THE CLOUDS GIVEN DEGREE OF DRY AIR
IMMEDIATELY TO THE WEST. PATTERN RECOGNITION SUGGESTS ENTRAINMENT AT
THE EDGE SHOULD AID DIURNAL MIXING TO FORCE STRATUS TO GO BROKEN BY
LATE MORNING...EVENTUALLY CLEARING OUT FOR THE AFTERNOON.
LOWERED MAX TEMPERATURES FOR MANY AREAS DUE TO THE CLOUD AND STEADY
COLD AIR ADVECTION. EXPECT TEMPERATURES TO EVENTUALLY REACH 60-61
DEGREES ACROSS THE SOUTH AND SAGINAW VALLEY VERY LATE IN THE DAY.
OTHERWISE TEMPERATURES ARE GOING TO STRUGGLE TO REACH THE LOWER 50S
IN THE THUMB.
FOR TONIGHT...THE COMPACT VORT OVER NORTHERN MANITOBA WILL GET
SQUEEZED WITH A ROGUE VORTICITY STREAMER OFF OF THE PACNW ANOMALY
MERGING OVER THE WESTERN GREAT LAKES. THIS WILL OCCUR DOWN THE FRONT
EDGE OF THE CENTRAL CONUS RIDGE...ALLOWING FOR A VERY HEALTHY
AGEOSTROPHIC RESPONSE AND STRIPE OF FRONTOGENESIS VERY LATE. ANY
SIGNIFICANT TEMPERATURE GRADIENT WILL RESIDE WELL WEST OF LOWER
MICHIGAN WHICH IS WHERE THE PRECIPITATION RESPONSE WILL OCCUR.
REGARDLESS...INCREASING CLOUDS LATE WILL ESTABLISH A FLOOR ON
MINIMUM TEMPERATURES TONIGHT.
&&
.LONG TERM...SATURDAY THROUGH THURSDAY
THE OVERALL PATTERN ACROSS NORTH AMERICA THIS WEEKEND WILL FEATURE A
QUASI OMEGA BLOCK. SHORT WAVE ENERGY NOW SHOWN ROTATING INTO NRN
MANITOBA IS FORECAST TO TRACK ACROSS THE ERN GREAT LAKES AND MID
ATLANTIC EARLY SATURDAY...LEADING TO DEEPENING OF AN UPPER LOW
ROTATING ACROSS NEW ENGLAND. LOWER MI WILL BE LOCATED BETWEEN THIS
SYSTEM AND AMPLIFYING MID LEVEL RIDGING ACROSS THE NRN PLAINS/UPPER
MS VALLEY. THIS WILL PLACE THE FORECAST AREA WITHIN A STRONGLY
CONFLUENT UPPER FLOW WITH PERSISTENT HIGH PRESSURE AT THE SURFACE.
THE RESIDENT AIRMASS ACROSS THE GREAT LAKES WILL BE COOL AND VERY
DRY. TEMPS ON SATURDAY SHOULD ONLY RISE TO THE LOW 60S OVER MUCH OF
THE FORECAST AREA WITH 850MB TEMPS HOVERING AROUND +2C. THE AIRMASS
WILL MODERATE DURING THE COURSE OF THE WEEKEND...WITH HIGHS EXPECTED
TO BE AROUND 70 BY MEMORIAL DAY. GIVEN THE DRY AIRMASS AND LIGHT
WINDS...NIGHTTIME LOWS WILL BE QUITE CHILLY THIS WEEKEND /30S AND
40S/.
A SEASONALLY STRONG 140+ KNOT UPPER JET IS FORECAST DIVE INTO THE
PACIFIC NORTHWEST EARLY NEXT WEEK...LEADING TO LONG WAVE TROUGH
AMPLIFICATION ACROSS THE WRN US AND A BUILDING SUBTROPICAL RIDGE
ACROSS THE SERN US. THIS WILL ALLOW THE MID LEVEL RIDGE TO BECOME
MORE PROGRESSIVE AND PASS EAST OF LOWER MI TOWARD MIDWEEK...ALLOWING
A SFC WARM FRONT TO LIFT ACROSS THE REGION FROM THE SOUTHWEST. THIS
WARM FRONT WILL ADVECT A WARM...MOIST AND UNSTABLE AIRMASS INTO THE
FORECAST AREA. THE GFS CONTINUES TO BRING THIS WARM FRONT THROUGH
FASTER THAN THE OTHER MODEL SOLUTIONS /SUGGESTING CONVECTION AS
EARLY AS MON NIGHT/. THE GFS HAS SOME OBVIOUS CONVECTIVE FEEDBACK
ISSUES DUE TO POTENTIAL MCS DEVELOPMENT OVER THE PLAINS. THE GFS IS
ALSO LESS AMPLIFIED WITH THE LONG WAVE TROUGH OVER THE WRN US. GIVEN
THE STRENGTH OF THE POLAR JET AND POTENTIAL PHASING WITH THE
SUBTROPICAL JET...THE MORE AMPLIFIED ECMWF REMAINS THE PREFERRED
SOLUTION. THIS SUGGESTS THE BETTER CHANCES FOR CONVECTION WILL HOLD
OFF UNTIL THE TUES NIGHT/WED TIME FRAME. DESPITE THIS UNCERTAINTY...
THE OVERALL TREND NEXT WEEK WILL BE FOR WARMER AND MORE HUMID
CONDITIONS WITH INCREASING CHANCES FOR THUNDERSTORMS.
&&
.MARINE...
UNSEASONABLE CONDITIONS ARE IN PLACE OVER THE CENTRAL GREAT LAKES
TODAY AS COLD AIR ADVECTION IS ONGOING WITHIN A DEEP TROUGH AXIS.
EFFICIENT NORTHERLY FLOW AND A LONG FETCH OVER THE WATERS WILL
SUSTAIN HIGH WAVE ACTIVITY FROM SAGINAW BAY DOWN TO PORT HURON.
RECENT WATER TEMPERATURE READINGS FROM THE BUOYS SUGGESTS THAT
CONDITIONS WILL BE SOLIDLY IN THE NEUTRAL REGIME OUT OVER THE OPEN
LAKE WHICH IS ATYPICAL FOR LATE MAY. IN FACT...CONDITIONS ARE
UNSTABLE FOR SAGINAW BAY WITH WATER TEMPERATURE READINGS SUGGESTING
LSTS ARE AT AROUND 13 TO 14 C VS AN 850MB TEMPERATURE THAT WILL BE
DIPPING DOWN TO -4C BY 12Z THIS MORNING. WILL EXPAND THE ADVISORY TO
INCLUDE INNER SAGINAW. CONDITIONS ARE MORE MARGINAL ON LAKE ST CLAIR
AND LAKE ERIE. WILL GIVE RESPECT TO PEAK OF THE COLD AIR ADVECTION
THAT WILL OCCUR THIS MORNING FOR THE SOUTHERN ZONES AND EXTEND THE
SMALL CRAFT FOR THEM AS WELL. THE STABLE SURFACE ANTICYCLONE WILL
BUILD INTO THE CENTRAL GREAT LAKES TONIGHT BRINGING A RETURN OF MUCH
MORE FAMILIAR STABLE SEASON MARINE WEATHER.
&&
.AVIATION...ISSUED 1146 PM EDT THU MAY 23 2013
//DISCUSSION...
WHAT REMAINS OF LOW VFR TO HIGH MVFR BOUNDARY LAYER CLOUDS WILL WORK
THEIR WAY THROUGH THE AREA WITHIN THE NEXT COUPLE OF HOURS. ONCE
THAT OCCURS, CLEAR SKIES BELOW 10KFT WILL PREVAIL FOR THE BALANCE
OF THE FORECAST PERIOD AS HIGH PRESSURE DOMINATES. DIURNAL HEATING
WILL ALLOW NORTHERLY WINDS TO GUST TO AROUND 20 KTS DURING PEAK
HEATING ON FRIDAY.
//DTW THRESHOLD THREATS...
* NONE
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...
SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM PORT AUSTIN TO PORT
HURON INCLUDING OUTER SAGINAW BAY...UNTIL 6 PM FRIDAY.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...CB
LONG TERM....SC
MARINE.......CB
AVIATION.....JVC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1248 AM CDT FRI MAY 24 2013
.UPDATE...
06Z AVIATION DISCUSSION ADDED BELOW.
&&
.SHORT TERM...THROUGH MONDAY
ISSUED AT 204 PM CDT THU MAY 23 2013
23.12Z RAOBS SHOW GOOD 925-850MB COLD ADVECTION ACROSS THE WRN GREAT
LAKES THIS MORNING IN MODERATE NORTHEAST FLOW. FRONTAL SLOPE OVER
THE STATE IS SOMETHING THAT WILL COME INTO PLAY FOR UPCOMING
FORECAST AND HOW FAR IT SLIDES SOUTHWEST. AT 12Z KINL-KABR HAD A 7C
TEMPERATURE DIFFERENCE AT 850MB /12C AT 925MB/. A MASSIVE DRYING
ACROSS MN OCCURRED OVERNIGHT WITH PRECIPITATELY WATER VALUES
PLUMMETING FROM 0.90 TO 0.32 INCHES...OR 136 TO 48 PERCENT NORMAL.
THE SURFACE RIDGE NOSING IN IS QUITE DRY WITH PRECIPITABLE WATER
VALUES IN THE 30 PERCENT RANGE ACROSS SRN CANADA. THIS GAVE WAY TO A
SUNNY BUT COOL DAY TODAY. A HIGHER AMPLITUDE RIDGE AXIS IS
ANCHORED IN THE DAKOTAS AND SOUTH...WHILE A DEEPER CYCLONE HAS NOW
SHIFTED ONSHORE INTO THE NWRN U.S. NUMEROUS SPOKES OF ENERGY ARE
CIRCULATING AROUND THAT LOW...ONE OF WHICH IS QUITE STRONG OVER
NEVADA WITH RAP ANALYSIS SHOWING A TROPOPAUSE FOLD TO NEAR
500MB...ON THE POLEWARD SIDE OF A MEASURED 100KT 250MB JET CORE
NOSE. THIS IS DRIVING HEIGHT FALLS ACROSS MT/ID/UT. SURFACE DEW
POINTS OF MEANING FOR CONVECTION ARE LOCATED IN OKLAHOMA...SOON TO
RETURN NORTHWARD.
FORECAST IS ON TRACK FOR CALMING WINDS TONIGHT AND CLEAR SKIES.
WIDESPREAD FROST SHOULD OCCUR WITH LOWER 30S FORECAST ACROSS NWRN
WI. WITH LOWER DEW POINTS OVER NWRN WI COUNTIES CURRENTLY...HAVE
DECIDED TO JUST ADD ALL OF THOSE COUNTIES INTO THE FROST ADVISORY.
BIG PICTURE DURING THIS PERIOD IS FALLING HEIGHTS AND PRESSURE IN
THE FRONT RANGE WITH SOUTHERLY FLOW INCREASING AND A RETURN OF
MOISTURE TO NEB/SD FRIDAY NIGHT. THIS WILL PLACE THE LOW-LEVEL
THERMAL BOUNDARY ACROSS THE FORECAST AREA FROM 850-925MB...SLIGHTLY
DISPLACED SWWRD...FROM KABR-KMLI. THE CONSENSUS NCEP MODELS AT
23.12Z REMAIN CONSISTENT WITH THEIR PREVIOUS RUNS ON THE FRONTAL
BOUNDARY BECOMING ACTIVE IN THE DAKOTAS/NEB FRIDAY EVENING AND
SHIFTING EAST INTO MN/IA OVERNIGHT. THE 23.00Z ECMWF/UKMET
SOLUTIONS DO AS WELL...HOWEVER THEY REMAIN FURTHER WEST.
THE 300/305K SURFACE IN THE NCEP SOLUTIONS REMAINS CONSISTENT WITH
AN 8G/KG MOISTURE SURGE ISENTROPICALLY LIFTING AND CONVERGING INTO
CENTRAL AND ERN MN FRIDAY OVERNIGHT WITH A FETCH OF ABOUT 500 J/KG
OF MUCAPE FEEDING IT. THE NAM SEEMS TO BE THE MOST AGRESSIVE. NOT
OVERLY IMPRESSIVE FOR SEVERE WEATHER...BUT RATHER THERE IS ENOUGH
FORCING TO GENERATE RA/TSRA SWWRD OF MSP. THE ECMWF SOLUTIONS
SUGGEST MORE OF A FOCUS IN SRN/SWRN MN. THE MAIN QUESTION IS HOW
FAR EAST DOES THIS CONVECTIVE COMPLEX TRACK FRIDAY NIGHT AND HOW FAR
EAST DOES THE FRONTAL BOUNDARY LIFT. HAVE INCREASED RAIN CHANCES
FURTHER EAST FOR FRIDAY NIGHT AND SATURDAY...HOWEVER WITH THE
VERIFICATION RECORD OF THE ECMWF...THERE IS STILL A CHANCE THE
EASTERN AREAS WILL BE DRY. CONFIDENCE IS LOW ON THE EXACT
LOCATION OF THE WEATHER...BUT HIGHER THAT IT WILL BE AN ACTIVE
FRONTAL ZONE WITH SHRA/ISO TSRA.
THIS QUESTION REMAINS THROUGH MONDAY...HOW FAR EAST WILL THE
FRONTAL BAND BE LOCATED. THE FRONT WILL LIKELY REMAIN ACTIVE WITH
SHOWERS/STORMS AND CLOUDS...AND HIGHS QUITE A BIT COOLER THAN OUTSIDE
THE BAND. OVERALL...HAVE INCREASED RAIN CHANCES IN THE WRN/SRN
FORECAST AREA AND TRIED TO REMAIN NEARLY DRY IN THE EAST. SEEMS
LIKE IT WILL BE A CLOUDY WEEKEND...AND THUS HAVE LOWERED HIGHS
SUNDAY AND MONDAY AS WELL. SEVERE WEATHER THREATS ARE MOST
POSSIBLE IN SWRN MN CLOSER TO THE CAPE POOL...AND MONDAY LOOKS
MOST FAVORABLE SHOULD THE INSTABILITY INCREASE AS THE WARM FRONT
MOVES TOWARD MN. HOWEVER...ACTIVITY ALONG THAT FRONT THIS WEEKEND
MAY HAVE MUCH TO DO WITH HOW THE ENVIRONMENT/FRONT EVOLVES MONDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 241 PM CDT THU MAY 23 2013
IT CONTINUES TO LOOK LIKE WE/LL UNFORTUNATELY NEED TO KEEP A
PROLONGED PERIOD OF CHANCE POPS IN THE FORECAST THROUGH THE WEEK
AS THE BAROCLINIC ZONE LINGERS IN THE AREA... WITH ELEVATED
INSTABILITY AND PERSISTENT WARM ADVECTION WORK TO GENERATE
SCATTERED SHRA/TSRA. THERE WILL UNDOUBTEDLY BE SOME DRY PERIODS...
WITH PCPN FOCUSED WHEN INDIVIDUAL SHORTWAVES RIPPLE SOUTHEAST
THROUGH THE UPPER FLOW... BUT AT THIS POINT IT IS IMPOSSIBLE TO
TRY AND PIN POINT WHEN SUCH DRY PERIODS MIGHT OCCUR. THE 12Z ECMWF
HAS COME AROUND MORE IN LINE WITH THE GFS IN KEEPING THINGS MORE
ACTIVE IN OUR AREA THROUGHOUT THE TIME PERIOD... ALTHOUGH BOTH
SUGGEST WE SHOULD FINALLY BRING THE UPPER TROUGH EAST TOWARD THE
REGION BY THE END OF THE WEEK. DEPENDING ON HOW THAT UNFOLDS... WE
COULD HAVE A POSSIBILITY FOR FOCUSED CONVECTION AND POSSIBLE
SEVERE WEATHER DURING THE THURSDAY-FRIDAY TIME FRAME. BUT... UNTIL
THAT POINT THE MAIN ISSUES WOULD LIKELY BE LOCALLY HEAVY RAIN AND
PERHAPS SOME HAIL. IN GENERAL... TEMPERATURES WILL WARM THROUGH
THE WEEK AS THE BONAFIDE WARM SECTOR SLOWLY LIFTS NORTH INTO THE
AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1248 AM CDT FRI MAY 24 2013
HIGH PRESSURE SLIDING INTO WI TONIGHT WILL PROVIDE EXCELLENT
CONDITIONS THROUGH MUCH OF THE DAY FRIDAY...BUT GOING THROUGH THE
DAY...WILL START TO SEE AN AREA OF SHRA/TSRA MOVE EAST THROUGH
THE DAKOTAS. BASED ON MPX SOUNDING LAST NIGHT...AIRMASS OVER THE
MPX AIRSPACE IS VERY DRY...WHICH SHOULD DELAY THE ONSET OF ANY
PRECIP. DID NOT INTRODUCE ANY VCSH UNTIL AFTER 00Z...BUT QUICKLY
SPREAD IT EAST ACROSS MN AS THE LLJ BEGINS NOSING INTO IOWA THIS
EVENING. GIVEN DRY ANTECEDENT CONDITIONS...KEPT CONDS VFR AS IT
WILL TAKE A WHILE TO MOISTEN THE LOW LEVELS...BUT BY 12Z
SATURDAY...PROBABILITIES FOR MVFR OR LOWER CIGS WILL BE INCREASING
PRECIPITOUSLY ACROSS MN. FOR WINDS...HIGH PRESSURE WILL BE SLIDING
OVER TOWARD MICH OVER THE DAY...WITH GRADIENT INCREASING AS A
RESULT. WINDS WILL BE STRONGEST WEST...WEAKEST EAST. BASED ON
SOUNDINGS...EXPECT SOME STRONG SUSTAINED WINDS...WITH MINIMAL
GUSTING. A 16G21KT TYPE DAY LOOKS TO AHEAD FOR WRN MN.
KMSP...CONFIDENCE HIGH IN TAF PARAMETERS UNTIL THE TAIL END OF THE
TAF. AT THIS POINT...KEPT ONLY A VCSH MENTION...THOUGH AT SOME
POINT LATE FRIDAY NIGHT...DO EXPECT THERE TO BE A PERIOD OF
SHRA/ISO TSRA. THIS WOULD BE MOST LIKELY BETWEEN 8Z AND 12Z. AS
FOR CIGS...KEPT THEM VFR...THOUGH CHANCE FOR MVFR...INCLUDING SUB
017 CIGS INCREASES AFTER 8Z SAT.
/OUTLOOK FOR KMSP/
SAT...CHC MVFR OR LOWER CIGS. CHC SHRA/TSRA. WINDS SE 10-15 KTS.
SUN...CHC MVFR OR LOWER CIGS. CHC SHRA/TSRA. WINDS SE 10-15 KTS.
MON...CHC MVFR OR LOWER CIGS. CHC SHRA/TSRA. WINDS SE 10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FROST ADVISORY UNTIL 7 AM CDT THIS MORNING FOR MNZ045-052-053-
063.
WI...FROST ADVISORY UNTIL 7 AM CDT THIS MORNING FOR WIZ014>016-
023>028.
&&
$$
SHORT TERM...BAUMGARDT/ARX
LONG TERM...
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
440 AM CDT FRI MAY 24 2013
.SHORT TERM...
OVERALL CHANCES OF CONVECTION WILL BE LESS FAVORABLE TODAY THAN
YESTERDAY. THERE IS AN OVERALL LACK OF FORCING BOTH LARGE AND AT THE
MESOSCALE LEVEL. UPPER LEVEL JET WINDS WILL UNDERGO A SIGNIFICANT
WEAKENING WITH A LACK OF A FOCUSED AREA OF UPPER LEVEL DIVERGENCE.
SOUTHWEST FLOW ALOFT WILL CONTINUE TO PERSIST OVER THE REGION BUT
THERE ARE NO DISCERNIBLE SHORT WAVES WITH THE FLOW FOR THIS
AFTERNOON. ANY WELL DEFINED LOW LEVEL BOUNDARY WILL BE WELL AWAY
FROM THE REGION WITH LITTLE TO NO LOW LEVEL FOCUS RESOLVED BY MODEL
SOLUTIONS. THE ONLY LOW LEVEL BOUNDARY MAY BE A LEFT OVER CONVECTIVE
BOUNDARY FROM CONVECTION EARLY THIS MORNING. OTHERWISE...THE ONLY
LOW LEVEL ENHANCEMENT MAY BE ALONG THE EDGE OF THE CAPROCK WITH
SOUTHEASTERLY WINDS. FURTHERMORE...ISENTROPIC SURFACES WILL BE
COMPOSED OF DOWNGLIDE.
THERE WILL BE NO SHORTAGE OF ATMOSPHERIC INSTABILITY. INSTABILITY
WILL BALLOON TO BETWEEN 2000-3000 J/KG WITH MAXIMUM VALUES OVER THE
ROLLING PLAINS WHERE MOISTURE IS DEEPEST. THE RAP EVEN SHOWS AN
ASTOUNDING 6000 J/KG OF SURFACE BASED CAPE BY THE AFTERNOON. SURFACE
DEW POINTS ARE NOT EXPECTED TO MIX OUT AS MUCH AS THEY DID ON
THURSDAY. SOUTHEAST WINDS WILL KEEP SURFACE DEW POINTS IN JUICY
TERRITORY RANGING FROM UPPER 50S TO MID 60S. PRECIPITABLE WATER
VALUES MAINTAIN RESPECTABLE VALUES BETWEEN 1.00 AND 1.25 INCHES.
HODOGRAPHS DEPICT GOOD TURNING IN LOW LEVELS BUT WIND SPEEDS ARE
FAIRLY LIGHT THROUGH MID LEVELS. THIS IS ALSO REFLECTED IN DEEP
LAYER SHEAR PROGS. SHEAR VECTORS FROM 0-6KM ARE ON THE ORDER OF ONLY
25-30KT. THIS WOULD LEAD TO FAIRLY SLOW STORM MOTIONS ALLOWING FOR A
DELUGE OF RAINFALL. OVERALL...CONVECTION LOOKS TO BE POORLY
ORGANIZED FOR TODAY. MODELS ARE ALSO INITIATING BY LATE IN THE
MORNING WHICH SEEMS EQUIVOCAL GIVEN THAT THE ATMOSPHERE WILL
REMAINED CAPPED UNTIL THE EARLY AFTERNOON AMONG OTHER REASONS
DISCUSSED ABOVE. LASTLY...WITH DEW POINTS NOT ANTICIPATED TO MIX OUT
NEARLY AS MUCH TODAY...TEMPERATURES WILL BE SIGNIFICANTLY COOLER
THIS AFTERNOON WITH MOSTLY 80S FORECAST. JDV
&&
.LONG TERM...
SOUTHWEST FLOW ALOFT EXPECTED TO REMAIN OVER THE SOUTH PLAINS
REGION THROUGH THE MIDDLE OF THE COMING WEEK. MOISTURE FLOW WILL
CONTINUE NORTHWARD WITH PRECIPITABLE WATER VALUES HOLDING IN
EXCESS OF AN INCH MORE OR LESS OVER THE CENTER OF THE AREA...LESS
WEST AND MORE EAST OF COURSE. THE SURFACE DRY-LINE WILL LIKELY
SLOSH MOSTLY BETWEEN THE WESTERN AND EASTERN SOUTH PLAINS DURING
THIS PERIOD...WHILE PRECISE LOCATIONS AT PEAK AFTERNOON HEATING
PERIODS REMAINS UNCERTAIN. INSTABILITY LEVELS ALSO EXPECTED TO
HOLD IN THE 1000-2000 JOULES PER KILOGRAM RANGE. WEAK EJECTING
DISTURBANCES MAY PROVIDE ENOUGH LIFT AT TIMES...WHILE WEAKLY
CONVERGENT LOW LEVEL FLOW ALSO COULD GENERATE LOW COVERAGE THUNDER
CHANCES THROUGH TUESDAY.
A STRONGER TROUGH STILL SEEMS LIKELY TO EJECT LATE WEDNESDAY AND
THURSDAY...PERHAPS IN TWO OR MORE PARTS LIKE THE GFS OR AS A
STRONGER TROUGH OR UPPER LOW LIKE THE ECMWF. EITHER WAY SHOULD
SUPPORT MORE BACKED UPPER FLOW AND EVEN DEEPER MOISTURE WEDNESDAY
AND OR THURSDAY AND MAY END UP WITH A MORE WIDESPREAD SEVERE
WEATHER THREAT AS WELL. THIS IS A STRONG ENOUGH AND CONSISTENT
ENOUGH SIGNAL FOR NOW TO RAISE THUNDERSTORM MENTION INTO THE
CHANCE CATEGORY WEDNESDAY. TEMPERATURES SHOULD WARM A BIT ABOVE
NORMAL LATE IN THE WEEKEND AND EARLY NEXT WEEK...WHILE WINDS
SHOULD INCREASE BY MID-WEEK WITH THE PASSING UPPER LOW OR LOW
PRESSURE TROUGH. RMCQUEEN
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 84 60 84 60 93 / 30 30 20 20 20
TULIA 83 62 83 60 92 / 30 30 20 20 10
PLAINVIEW 83 63 83 61 91 / 30 30 20 20 10
LEVELLAND 85 64 84 62 92 / 30 30 20 20 10
LUBBOCK 83 65 83 63 92 / 30 30 20 20 10
DENVER CITY 85 64 84 61 92 / 30 30 20 20 10
BROWNFIELD 85 65 84 62 92 / 30 30 20 20 10
CHILDRESS 83 66 85 66 93 / 30 30 20 20 10
SPUR 82 66 82 63 91 / 30 30 20 20 10
ASPERMONT 85 67 84 66 92 / 40 40 20 20 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
01/05
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1120 AM EDT FRI MAY 24 2013
.UPDATE (REST OF TODAY AND TONIGHT)...
15Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUE TO SHOW AN ACTIVE UPPER
LEVEL PATTERN IN PLACE OVER THE CONUS. LONGWAVE PATTERN IS DOMINATED
BY DEEP TROUGHS ALONG BOTH THE PACIFIC AND ATLANTIC COASTS WHILE A
LONGWAVE RIDGE AXIS BISECTS THE CONTINENT OVER THE CENTRAL PLAINS.
OUR FORECAST AREA RESIDES AT THE BASE OF THE EASTERN CONUS TROUGH. A
STRONG SHORTWAVE EMBEDDED WITHIN THIS TROUGH IS NOW DROPPING
SOUTHEASTWARD OVER THE MID-ATLANTIC/CAROLINAS. THIS ENERGY WILL NOT
ONLY ACT TO CLOSE OFF A POTENT UPPER LOW OFF THE NEW ENGLAND
COAST...BUT ITS MOMENTUM WILL ALSO HELP DRIVE A LATE SEASON COLD
FRONT DOWN AND THROUGH THE FLORIDA PENINSULA DURING THE NEXT 12-18
HOURS. 24/12Z KTBW SOUNDING PROFILE WAS DRY...BUT NOT UNSEASONABLY
DRY...JUST YET. HOWEVER LOOKING UPSTREAM TOWARD BIRMINGHAM AND
ATLANTA WE BEGIN TO SEE A MUCH DRIER AIRMASS ABOVE THE SURFACE WHICH
WILL BE SETTLING SOUTHWARD AND OVER OUR HEADS FOR THE HOLIDAY
WEEKEND.
AT THE SURFACE...AS MENTIONED ABOVE...A LATE SEASON COLD FRONT IS
READY TO ADVANCE THROUGH THE FORECAST AREA LATER TODAY AND TONIGHT.
THE FRONT IS CURRENTLY ANALYZED UP NEAR THE I-10 CORRIDOR WITH A
DISTINCT DEWPOINT DISCONTINUITY FROM MUCH OF THE FLORIDA PENINSULA
UP TO THE INTERIOR PANHANDLE AND SOUTHERN PORTION OF AL/GA. THIS
MORE COMFORTABLE AIRMASS IS ON ITS WAY TO US.
SOME EARLY MORNING PATCHES OF FOG ARE ALL BUT GONE LATE THIS MORNING
LEADING TO MOSTLY SUNNY SKIES REGION-WIDE. STILL HAVE ENOUGH
BOUNDARY LAYER MOISTURE AND EVENTUAL SEA-BREEZE FOCUS TO EXPECT A
SCT CUMULUS FIELD TO BECOME ESTABLISHED FOR THE AFTERNOON...MAINLY
ALONG AND SOUTH OF THE I-4 CORRIDOR. CAN NOT RULE OUT THE
POSSIBILITY FOR AN ISOLATED SHOWER OR 2 TO DEVELOP LATE
AFTERNOON/EARLY EVENING TO THE SOUTH OF I-4 WHERE FRONTAL AND
SEA-BREEZE CONVERGENCE ALIGN ENOUGH TO OVERCOME THE NO SO FAVORABLE
TROP FOR DEEP CONVECTION. ONLY HAVE POPS AROUND 20% FOR THESE
CENTRAL AND SOUTHERN ZONES...AND NO RAIN CHANCES NORTH OF I-4. ANY
ISOLATED SHOWERS THAT DO DEVELOP WILL LIKELY BE SHORT-LIVED AS THEY
QUICKLY ENTRAIN DRY AND HOSTILE THETA-E AIR ABOVE 700MB INTO THEIR
COLUMN.
TEMPERATURES THE REST OF THE DAY WILL BE SEASONABLE WITH MANY INLAND
LOCATIONS PEAKING WITHIN A DEGREE OR TWO OF 90. TYPICAL FOR THIS
TIME OF YEAR...DEVELOPING AND STRENGTHENING ONSHORE FLOW WILL KEEP
TEMPERATURES IN THE 80S NEAR THE BEACHES.
TONIGHT...SURFACE FRONT SLIPS SOUTH OF THE REGION FOLLOWED QUICKLY
BY STRONG CONTINENTAL HIGH PRESSURE RIDGING DOWN FROM THE NORTH. A
FAVORABLE NNE DRAINAGE FLOW WILL ALLOW SOME OF OUR NORTHERN AREAS
AROUND LEVY/CITRUS COUNTIES TO DROP INTO THE MID/UPPER 50S TOWARD
SUNRISE ON SATURDAY...WHILE THE REMAINDER OF THE REGION DROPS DOWN
INTO THE 60S. ANY ISOLATED EVENING SHOWERS OVER THE FAR SOUTHERN
ZONES WILL END WITH THE FRONTAL PASSAGE SETTING UP A DRY AND
SEASONABLE PLEASANT OVERNIGHT PERIOD. ENJOY!
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL WITH AT THE MOST FEW-SCT CLOUDS. NORTH
AND NORTHWEST WINDS...GUSTY AT TIMES THIS AFTERNOON.
&&
.MARINE...
WINDS WILL START TO INCREASE TO CAUTIONARY LEVELS FOR
OFFSHORE ZONES TONIGHT INTO EARLY SATURDAY MORNING WITH WAVE
HEIGHTS INCREASING TO UP TO 4 FEET. STRONG HIGH PRESSURE WILL
BUILD NORTH OF THE STATE OVER THE HOLIDAY WEEKEND AND INTO THE
MIDDLE OF NEXT WEEK. THIS WILL RESULT IN AN ELEVATED EASTERLY
FLOW ACROSS THE WATERS...WITH PERIODS OF EXERCISE CAUTION AND
ADVISORY HEADLINES NECESSARY FOR MOST MARINE ZONES...PARTICULARLY
DURING THE EVENING AND OVERNIGHT HOURS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 89 69 90 66 / 10 10 0 0
FMY 91 70 91 65 / 20 20 0 0
GIF 93 67 89 63 / 20 10 0 0
SRQ 86 70 90 64 / 10 10 0 0
BKV 90 62 88 55 / 10 10 0 0
SPG 89 73 88 71 / 10 10 0 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE...MROCZKA
AVIATION...RUDE
AREA FORECAST DISCUSSION
NWS GOODLAND KS
829 AM MDT FRI MAY 24 2013
.UPDATE...
ISSUED AT 819 AM MDT FRI MAY 24 2013
MADE A FEW CHANGES TO THE FORECAST FOR TODAY. THE FIRST BEING
TO INCREASE THE WINDS FOR TODAY...ESPECIALLY DURING THE MORNING.
WINDS HAVE BEEN VARYING QUITE A BIT OVER THE PAST COUPLE OF HOURS.
HAVE BEEN CONTEMPLATING A WIND ADVISORY FOR THE WESTERN 2/3S OF
THE AREA. BIGGEST UNCERTAINTY IS WILL THE SUSTAINED WINDS REMAIN
AT 30 MPH OR CONTINUE TO VARY. IN ADDITION THE WINDS MAY
STRENGTHEN DURING THE AFTERNOON BEHIND THE WARM FRONT. AT THIS
POINT WILL ONLY INCREASE THE SUSTAINED WINDS TO JUST UNDER 30 MPH
FOR THE REST OF THE DAY FOR THE MAJORITY OF THE AREA...WHICH IS
JUST UNDER WIND ADVISORY CRITERIA. IF CRITERIA IS REACHED AM
CONFIDENT IT WILL BE VERY LOW END.
ALSO REMOVED THE MENTION OF FOG FOR ALL BUT EAST CENTRAL COLORADO
THIS MORNING. WEB CAMS AT FIRST VIEW AND GENOA BOTH SHOW
VISIBILITIES OF LESS THAN A MILE. DUE TO THE RATHER SMALL AREA
BEING AFFECTED AND SINCE THE FOG WILL BEGIN TO LIFT IN THE NEXT
HOUR OR SO...WILL NOT BE ISSUING ANY FOG RELATED HAZARDS.
DID DROP THE CHANCES FOR PRECIP. DOWN SOME THIS MORNING OVER THE
EAST. MODELS DO SHOW A MINOR UPPER LEVEL SHORT WAVE TROUGH MOVING
THROUGH...HOWEVER SOUNDINGS DO NOT LOOK VERY FAVORABLE FOR STORM
DEVELOPMENT THIS MORNING. WILL LEAVE A SLIGHT CHANCE IN...BUT THIS
MAY BE TOO MUCH FOR THE MORNING.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 434 AM MDT FRI MAY 24 2013
FORECAST PROBLEMS WILL BE NUMEROUS THROUGH THE WEEKEND. SATELLITE
SHOWING A FASTER/MORE PROGRESSIVE FLOW OVER THE PACIFIC WHICH THEN
TRANSITIONS TO A SLOWER AND MORE AMPLIFIED FLOW OVER NORTH AMERICA.
THE RIDGE OVER THE CENTRAL PORTION OF THE COUNTRY HAS INCREASED IN
AMPLITUDE OVER THE LAST 24 HOURS. UPPER LOW OVER THE PACIFIC
NORTHWEST HAS MOVED LITTLE IN THE LAST 24 HOURS. FRONT THAT MOVED
THROUGH YESTERDAY REMAINS DRAPED WELL SOUTH AND WEST OF THE AREA AT
THIS TIME.
THE SREF...NAM AND CANADIAN INITIALIZED BEST ON THE JET LEVEL WINDS
OVER OUR AREA. MODELS HAVING A LITTLE TROUBLE WITH THE DETAILS AT
MID LEVELS. OVERALL THE SREF AND NAM WERE DOING SLIGHTLY BETTER THAN
THE GFS...CANADIAN AND CANADIAN. THE NAM LOOKED LIKE IT WAS CATCHING
THE MINOR SHORTWAVE TROUGH TO OUR SOUTHWEST THE BEST. THE GFS WAS
DOING SLIGHTLY BETTER THAN THE ECMWF ON THE LOW LEVEL THERMAL FIELD.
THE GFS WAS TOO AGGRESSIVE WITH THE LOW LEVEL MOISTURE RETURN WITH
THE NAM DOING A LITTLE BETTER. MODELS DO NOT QUITE HAVE THE BOUNDARY
TO OUR SOUTH QUITE FAR ENOUGH SOUTH. THE NAM WAS DOING A LITTLE
BETTER HERE. ALSO MODELS HAD QPF TOO FAR NORTH BY 06Z WITH THE GFS...
CANADIAN AND THE SREF THE WORST OFFENDERS. AGAIN THE NAM WAS DOING
BETTER HERE.
TODAY/TONIGHT...MOST OF THE MODEL OUTPUT SHOWS A WEAK LEFT FRONT
QUADRANT OVER THE AREA BEGINNING NEAR 12Z AND MAINLY AFFECTING THE
SOUTHEAST HALF. A SMALL CLUSTER OF THUNDERSTORMS HAD DEVELOPED OVER
NORTHEAST NEW MEXICO AND THE PANHANDLE AREA. THIS LOOKS TO BE IN
RESPONSE TO SHORTWAVE TROUGH AND THE WEAK LEFT FRONT QUADRANT OF THE
JET. HOWEVER THAT DISSIPATED WITH ISOLATED THUNDERSTORMS DEVELOPING
OVER/NEAR THE EASTERN PORTION OF THE AREA.
THE NAM FOR THE MOST PART HAS THIS AREA DEPICTED WELL...ESPECIALLY
FOR THE JET. SO GOING BY THAT...WILL HAVE A SLIGHT CHANCE TO CHANCE
OF THUNDERSTORMS THROUGH MAINLY THE MORNING WITH IT POSSIBLY
LINGERING INTO EARLY AFTERNOON IN THE FAR EAST. STRATUS IS MOSTLY
OCCURRING OVER THE AREA AT THIS TIME WITH THE FOG CONFINED TO EASTERN
COLORADO. THIS MAKES SENSE WITH THIS BEING THE MAIN AREA OF LOW LEVEL
TRANSPORT OF MOISTURE AT THIS TIME. THE HRRR AND NAM INDICATE THE
BEST CHANCE OF FOG OVER THE WESTERN HALF OF THE AREA. A FEW SPOTS
ALSO REPORTING DRIZZLE AND SOUNDINGS WOULD INDICATE THAT WILL
CONTINUE INTO THIS MORNING. SO WILL HAVE AREAS OF FOG WITH PATCHY
DRIZZLE IN THE WESTERN HALF AND PATCHY FOG FURTHER EAST.
SOUTHERLY WINDS INCREASE INTO THE WINDY CATEGORY. GRADIENT DEFINITELY
SUPPORTS NEAR ADVISORY CRITERIA IN THE WEST BUT THERE THE 3 HOUR
PRESSURE FALLS ARE NOT THAT HIGH. GLD VWP DEFINITELY WOULD
SUPPORT WINDY. WILL RAISE WINDS TO NEAR ADVISORY IN THE FAR WEST.
NOW FOR THE PRECIPITATION CHANCES DURING THE AFTERNOON AND NIGHT.
SUBSIDENCE/DRYING OCCURS OUT EAST RATHER QUICKLY AFTER FIRST
SHORTWAVE. INSTABILITY AXIS...BEST HEATING...MID/UPPER LEVEL LIFT
AND SURFACE CONVERGENCE DEVELOPS NEAR OR OVER THE WESTERN PORTION OF
THE AREA. SO WILL GRADUALLY RAMP UP POPS DURING THE AFTERNOON. BEST
LIFT AND MOISTURE LOOK TO RESIDE OVER THE NORTH DURING THE NIGHT
AND HAVE INCREASED POPS OVER THE NORTH WITH LOWER POPS FURTHER
SOUTH. THUNDERSTORMS LOOK TO BE DONE BY 12Z. LOW LEVEL MOISTURE
INCREASES OVER THE EASTERN HALF TO TWO THIRDS AFTER 06Z. AT THIS TIME
MODELS INDICATING MOSTLY STRATUS. WILL INSERT FOG WITH THE GREATEST
CHANCE IN THE FAR EAST.
NOT A GOOD FEEL ON THE MAXES WITH THEM BEING DETERMINED BY THE
EXTENT OF THE STRATUS AND HOW LONG IT TAKES TO BURN OFF. IT IS
POSSIBLE THAT THICK CLOUD COVER WILL NOT BREAK UP UNTIL LATE
MORNING. SO TRENDED THE FORECAST COOLER.
SATURDAY/SATURDAY NIGHT...FOG WILL CLEAR OUT DURING THE MORNING.
MODELS NOT AGREEING WHERE DRY LINE ENDS UP...WHERE THE INSTABILITY
AXIS ENDS UP...WHERE THE CAP IS THE LEAST...AND SHORTWAVE DETAILS.
AT THIS TIME IT LOOKS LIKE THE DRY LINE ENDS UP NEAR OR A LITTLE
WEST OF THE COLORADO BORDER. ONE SHORTWAVE TROUGH EXITS THE EASTERN
PORTION OF THE AREA EARLY IN THE AFTERNOON WITH ANOTHER ONE
APPROACHING LATE IN THE AFTERNOON WITH THE BRUNT OF ITS LIFT COMING
THROUGH DURING THE NIGHT. MODELS ARE GENERATING QPF WHERE THERE IS
A STRONG CAP.
AS IT LOOKS NOW THE MAIN TIME FOR PRECIPITATION WILL WAIT TO BEGIN
UNTIL MID TO LATE EVENING. THE BEST CHANCE FOR THUNDERSTORMS WILL
BE EAST OF THE COLORADO BORDER...AND ESPECIALLY IN THE FAR EAST.
LOW LEVEL THERMAL FIELD IS MUCH WARMER THAN TODAYS. HOWEVER...IF
STRATUS/FOG LAST LONGER OR THE LEE TROUGH IS STRONGER/FURTHER WEST...
THE WINDS WILL BE MORE FROM AN EASTERLY DIRECTION AND NOT ALLOW FOR
AS BIG A WARM UP. KEPT THE WESTERN AREAS WARMER WITH COOLER MAXES
FURTHER EAST.
IN REGARDS TO FIRE...THE LOWEST RHS LOOK TO BE IN COLORADO AT THIS
TIME. HOWEVER...THAT IS WHERE THE LIGHTEST WIND FIELD IS. DUE TO A
LOT OF UNCERTAINTY...WAS NOT CONFIDENT ENOUGH TO THROW OUT A WATCH.
WILL HIGHLIGHT IN THE FIRE WEATHER FORECAST AND HWO.
SUNDAY/SUNDAY NIGHT...A LOT MORE DISAGREEMENT IN DETAILS SHOW UP IN
THIS PERIOD. CURRENT MODEL OUTPUT SUPPORTED THE GOING PRECIPITATION
FORECAST FOR THIS PERIOD AND LEFT IT ALONE. ALSO ONLY MADE SLIGHT
ADJUSTMENTS TO THE TEMPERATURE FORECAST AS WELL. P
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 235 AM MDT FRI MAY 24 2013
MEDIUM RANGE MODEL DIFFERENCES EMERGE EARLY IN THE EXTENDED
PERIOD...PARTICULARLY WITH REGARD TO AMPLITUDE OF UPPER FLOW
PATTERN. THE ECMWF IS MORE AMPLIFIED ON MONDAY WITH BOTH THE UPPER
RIDGE POSITIONED TO OUR EAST AND ALSO THE WESTERN CONUS UPPER
TROUGH. THE POSITION OF THESE FEATURES WILL PLACE OUR AREA IN
SOUTHWESTERLY FLOW ALOFT WITH THE LIKELIHOOD OF WEAK EMBEDDED
DIFFICULT TO TIME SHORTWAVES THAT COULD POTENTIALLY ENHANCE
PRECIPITATION DEVELOPMENT. BY TUESDAY THE PATTERN AMPLIFIES
FURTHER AND ECMWF CLOSES OFF AN UPPER LOW OVER THE SOUTHWEST
CONUS. GFS MAINTAINS AN OPEN WAVE AND SHIFTS IT EASTWARD WITH
NOTICEABLE HEIGHT FALLS OVER OUR AREA BY LATE TUESDAY AND
ESPECIALLY WEDNESDAY. THE NEW 00Z ECMWF HAS TRENDED THE DIRECTION
OF THE MORE PROGRESSIVE GFS AND OPENS UP THE SOUTHWEST CONUS UPPER
LOW RATHER THAN KEEP IT CLOSED AND SLOWLY MOVING IT EAST AS THE
12Z ECMWF INDICATED. STILL THE ECMWF IS CONSIDERABLY SLOWER THAN
THE GFS WITH THE EASTWARD PROGRESSION OF THIS TROUGH. THIS LEADS
TO A LOW CONFIDENCE FORECAST NEXT WEEK. GFS WOULD FAVOR A
POTENTIALLY WIDESPREAD PRECIPITATION / ORGANIZED CONVECTIVE EVENT
WEDNESDAY WHILE THE ECMWF SOLUTION WOULD SUPPORT A SIMILAR
SITUATION BY LATE WEDNESDAY / WEDNESDAY NIGHT INTO THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 546 AM MDT FRI MAY 24 2013
IFR CONDITIONS CURRENTLY AT GLD DUE TO LOW CIGS. THIS SHOULD
PERSIST IN THE NEAR TERM FOLLOWED BY AN INCREASE TO MVFR AFTER
AROUND 15-16Z AND EVENTUALLY VFR THIS AFTERNOON. MEANWHILE MVFR
CONDITIONS MAY PERSIST A LITTLE LONGER AT MCK. SOME UNCERTAINTY
WITH REGARD TO CONVECTION LATER THIS EVENING AND TONIGHT SO OPTED
TO LEAVE VCTS OUT FOR NOW. THIS MAY NEED TO BE ADDED AT A LATER TIME IF
CONFIDENCE INCREASES. LATER TONIGHT VFR CONDITIONS DUE TO CIGS ARE
EXPECTED AT MCK.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...BULLER
LONG TERM...BRB
AVIATION...BRB
AREA FORECAST DISCUSSION
NWS GOODLAND KS
550 AM MDT FRI MAY 24 2013
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 434 AM MDT FRI MAY 24 2013
FORECAST PROBLEMS WILL BE NUMEROUS THROUGH THE WEEKEND. SATELLITE
SHOWING A FASTER/MORE PROGRESSIVE FLOW OVER THE PACIFIC WHICH THEN
TRANSITIONS TO A SLOWER AND MORE AMPLIFIED FLOW OVER NORTH AMERICA.
THE RIDGE OVER THE CENTRAL PORTION OF THE COUNTRY HAS INCREASED IN
AMPLITUDE OVER THE LAST 24 HOURS. UPPER LOW OVER THE PACIFIC
NORTHWEST HAS MOVED LITTLE IN THE LAST 24 HOURS. FRONT THAT MOVED
THROUGH YESTERDAY REMAINS DRAPED WELL SOUTH AND WEST OF THE AREA AT
THIS TIME.
THE SREF...NAM AND CANADIAN INITIALIZED BEST ON THE JET LEVEL WINDS
OVER OUR AREA. MODELS HAVING A LITTLE TROUBLE WITH THE DETAILS AT
MID LEVELS. OVERALL THE SREF AND NAM WERE DOING SLIGHTLY BETTER THAN
THE GFS...CANADIAN AND CANADIAN. THE NAM LOOKED LIKE IT WAS CATCHING
THE MINOR SHORTWAVE TROUGH TO OUR SOUTHWEST THE BEST. THE GFS WAS
DOING SLIGHTLY BETTER THAN THE ECMWF ON THE LOW LEVEL THERMAL FIELD.
THE GFS WAS TOO AGGRESSIVE WITH THE LOW LEVEL MOISTURE RETURN WITH
THE NAM DOING A LITTLE BETTER. MODELS DO NOT QUITE HAVE THE BOUNDARY
TO OUR SOUTH QUITE FAR ENOUGH SOUTH. THE NAM WAS DOING A LITTLE
BETTER HERE. ALSO MODELS HAD QPF TOO FAR NORTH BY 06Z WITH THE GFS...
CANADIAN AND THE SREF THE WORST OFFENDERS. AGAIN THE NAM WAS DOING
BETTER HERE.
TODAY/TONIGHT...MOST OF THE MODEL OUTPUT SHOWS A WEAK LEFT FRONT
QUADRANT OVER THE AREA BEGINNING NEAR 12Z AND MAINLY AFFECTING THE
SOUTHEAST HALF. A SMALL CLUSTER OF THUNDERSTORMS HAD DEVELOPED OVER
NORTHEAST NEW MEXICO AND THE PANHANDLE AREA. THIS LOOKS TO BE IN
RESPONSE TO SHORTWAVE TROUGH AND THE WEAK LEFT FRONT QUADRANT OF THE
JET. HOWEVER THAT DISSIPATED WITH ISOLATED THUNDERSTORMS DEVELOPING
OVER/NEAR THE EASTERN PORTION OF THE AREA.
THE NAM FOR THE MOST PART HAS THIS AREA DEPICTED WELL...ESPECIALLY
FOR THE JET. SO GOING BY THAT...WILL HAVE A SLIGHT CHANCE TO CHANCE
OF THUNDERSTORMS THROUGH MAINLY THE MORNING WITH IT POSSIBLY
LINGERING INTO EARLY AFTERNOON IN THE FAR EAST. STRATUS IS MOSTLY
OCCURRING OVER THE AREA AT THIS TIME WITH THE FOG CONFINED TO EASTERN
COLORADO. THIS MAKES SENSE WITH THIS BEING THE MAIN AREA OF LOW LEVEL
TRANSPORT OF MOISTURE AT THIS TIME. THE HRRR AND NAM INDICATE THE
BEST CHANCE OF FOG OVER THE WESTERN HALF OF THE AREA. A FEW SPOTS
ALSO REPORTING DRIZZLE AND SOUNDINGS WOULD INDICATE THAT WILL
CONTINUE INTO THIS MORNING. SO WILL HAVE AREAS OF FOG WITH PATCHY
DRIZZLE IN THE WESTERN HALF AND PATCHY FOG FURTHER EAST.
SOUTHERLY WINDS INCREASE INTO THE WINDY CATEGORY. GRADIENT DEFINITELY
SUPPORTS NEAR ADVISORY CRITERIA IN THE WEST BUT THERE THE 3 HOUR
PRESSURE FALLS ARE NOT THAT HIGH. GLD VWP DEFINITELY WOULD
SUPPORT WINDY. WILL RAISE WINDS TO NEAR ADVISORY IN THE FAR WEST.
NOW FOR THE PRECIPITATION CHANCES DURING THE AFTERNOON AND NIGHT.
SUBSIDENCE/DRYING OCCURS OUT EAST RATHER QUICKLY AFTER FIRST
SHORTWAVE. INSTABILITY AXIS...BEST HEATING...MID/UPPER LEVEL LIFT
AND SURFACE CONVERGENCE DEVELOPS NEAR OR OVER THE WESTERN PORTION OF
THE AREA. SO WILL GRADUALLY RAMP UP POPS DURING THE AFTERNOON. BEST
LIFT AND MOISTURE LOOK TO RESIDE OVER THE NORTH DURING THE NIGHT
AND HAVE INCREASED POPS OVER THE NORTH WITH LOWER POPS FURTHER
SOUTH. THUNDERSTORMS LOOK TO BE DONE BY 12Z. LOW LEVEL MOISTURE
INCREASES OVER THE EASTERN HALF TO TWO THIRDS AFTER 06Z. AT THIS TIME
MODELS INDICATING MOSTLY STRATUS. WILL INSERT FOG WITH THE GREATEST
CHANCE IN THE FAR EAST.
NOT A GOOD FEEL ON THE MAXES WITH THEM BEING DETERMINED BY THE
EXTENT OF THE STRATUS AND HOW LONG IT TAKES TO BURN OFF. IT IS
POSSIBLE THAT THICK CLOUD COVER WILL NOT BREAK UP UNTIL LATE
MORNING. SO TRENDED THE FORECAST COOLER.
SATURDAY/SATURDAY NIGHT...FOG WILL CLEAR OUT DURING THE MORNING.
MODELS NOT AGREEING WHERE DRYLINE ENDS UP...WHERE THE INSTABILITY
AXIS ENDS UP...WHERE THE CAP IS THE LEAST...AND SHORTWAVE DETAILS.
AT THIS TIME IT LOOKS LIKE THE DRY LINE ENDS UP NEAR OR A LITTLE
WEST OF THE COLORADO BORDER. ONE SHORTWAVE TROUGH EXITS THE EASTERN
PORTION OF THE AREA EARLY IN THE AFTERNOON WITH ANOTHER ONE
APPROACHING LATE IN THE AFTERNOON WITH THE BRUNT OF ITS LIFT COMING
THROUGH DURING THE NIGHT. MODELS ARE GENERATING QPF WHERE THERE IS
A STRONG CAP.
AS IT LOOKS NOW THE MAIN TIME FOR PRECIPITATION WILL WAIT TO BEGIN
UNTIL MID TO LATE EVENING. THE BEST CHANCE FOR THUNDERSTORMS WILL
BE EAST OF THE COLORADO BORDER...AND ESPECIALLY IN THE FAR EAST.
LOW LEVEL THERMAL FIELD IS MUCH WARMER THAN TODAYS. HOWEVER...IF
STRATUS/FOG LAST LONGER OR THE LEE TROUGH IS STRONGER/FURTHER WEST...
THE WINDS WILL BE MORE FROM AN EASTERLY DIRECTION AND NOT ALLOW FOR
AS BIG A WARMUP. KEPT THE WESTERN AREAS WARMER WITH COOLER MAXES
FURTHER EAST.
IN REGARDS TO FIRE...THE LOWEST RHS LOOK TO BE IN COLORADO AT THIS
TIME. HOWEVER...THAT IS WHERE THE LIGHTEST WIND FIELD IS. DUE TO A
LOT OF UNCERTAINTY...WAS NOT CONFIDENT ENOUGH TO THROW OUT A WATCH.
WILL HIGHLIGHT IN THE FIRE WEATHER FORECAST AND HWO.
SUNDAY/SUNDAY NIGHT...A LOT MORE DISAGREEMENT IN DETAILS SHOW UP IN
THIS PERIOD. CURRENT MODEL OUTPUT SUPPORTED THE GOING PRECIPITATION
FORECAST FOR THIS PERIOD AND LEFT IT ALONE. ALSO ONLY MADE SLIGHT
ADJUSTMENTS TO THE TEMPERATURE FORECAST AS WELL. P
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 235 AM MDT FRI MAY 24 2013
MEDIUM RANGE MODEL DIFFERENCES EMERGE EARLY IN THE EXTENDED
PERIOD...PARTICULARLY WITH REGARD TO AMPLITUDE OF UPPER FLOW
PATTERN. THE ECMWF IS MORE AMPLIFIED ON MONDAY WITH BOTH THE UPPER
RIDGE POSITIONED TO OUR EAST AND ALSO THE WESTERN CONUS UPPER
TROUGH. THE POSITION OF THESE FEATURES WILL PLACE OUR AREA IN
SOUTHWESTERLY FLOW ALOFT WITH THE LIKELIHOOD OF WEAK EMBEDDED
DIFFICULT TO TIME SHORTWAVES THAT COULD POTENTIALLY ENHANCE
PRECIPITATION DEVELOPMENT. BY TUESDAY THE PATTERN AMPLIFIES
FURTHER AND ECMWF CLOSES OFF AN UPPER LOW OVER THE SOUTHWEST
CONUS. GFS MAINTAINS AN OPEN WAVE AND SHIFTS IT EASTWARD WITH
NOTICEABLE HEIGHT FALLS OVER OUR AREA BY LATE TUESDAY AND
ESPECIALLY WEDNESDAY. THE NEW 00Z ECMWF HAS TRENDED THE DIRECTION
OF THE MORE PROGRESSIVE GFS AND OPENS UP THE SOUTHWEST CONUS UPPER
LOW RATHER THAN KEEP IT CLOSED AND SLOWLY MOVING IT EAST AS THE
12Z ECMWF INDICATED. STILL THE ECMWF IS CONSIDERABLY SLOWER THAN
THE GFS WITH THE EASTWARD PROGRESSION OF THIS TROUGH. THIS LEADS
TO A LOW CONFIDENCE FORECAST NEXT WEEK. GFS WOULD FAVOR A
POTENTIALLY WIDESPREAD PRECIPITATION / ORGANIZED CONVECTIVE EVENT
WEDNESDAY WHILE THE ECMWF SOLUTION WOULD SUPPORT A SIMILAR
SITUATION BY LATE WEDNESDAY / WEDNESDAY NIGHT INTO THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 546 AM MDT FRI MAY 24 2013
IFR CONDITIONS CURRENTLY AT GLD DUE TO LOW CIGS. THIS SHOULD
PERSIST IN THE NEAR TERM FOLLOWED BY AN INCREASE TO MVFR AFTER
AROUND 15-16Z AND EVENTUALLY VFR THIS AFTERNOON. MEANWHILE MVFR
CONDITIONS MAY PERSIST A LITTLE LONGER AT MCK. SOME UNCERTAINTY
WITH REGARD TO CONVECTION LATER THIS EVENING AND TONIGHT SO OPTED
TO LEAVE VCTS OUT FOR NOW. THIS MAY NEED TO BE ADDED AT A LATER TIME IF
CONFIDENCE INCREASES. LATER TONIGHT VFR CONDITIONS DUE TO CIGS ARE
EXPECTED AT MCK.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...BRB
AVIATION...BRB
AREA FORECAST DISCUSSION
NWS GOODLAND KS
434 AM MDT FRI MAY 24 2013
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 434 AM MDT FRI MAY 24 2013
FORECAST PROBLEMS WILL BE NUMEROUS THROUGH THE WEEKEND. SATELLITE
SHOWING A FASTER/MORE PROGRESSIVE FLOW OVER THE PACIFIC WHICH THEN
TRANSITIONS TO A SLOWER AND MORE AMPLIFIED FLOW OVER NORTH AMERICA.
THE RIDGE OVER THE CENTRAL PORTION OF THE COUNTRY HAS INCREASED IN
AMPLITUDE OVER THE LAST 24 HOURS. UPPER LOW OVER THE PACIFIC
NORTHWEST HAS MOVED LITTLE IN THE LAST 24 HOURS. FRONT THAT MOVED
THROUGH YESTERDAY REMAINS DRAPED WELL SOUTH AND WEST OF THE AREA AT
THIS TIME.
THE SREF...NAM AND CANADIAN INITIALIZED BEST ON THE JET LEVEL WINDS
OVER OUR AREA. MODELS HAVING A LITTLE TROUBLE WITH THE DETAILS AT
MID LEVELS. OVERALL THE SREF AND NAM WERE DOING SLIGHTLY BETTER THAN
THE GFS...CANADIAN AND CANADIAN. THE NAM LOOKED LIKE IT WAS CATCHING
THE MINOR SHORTWAVE TROUGH TO OUR SOUTHWEST THE BEST. THE GFS WAS
DOING SLIGHTLY BETTER THAN THE ECMWF ON THE LOW LEVEL THERMAL FIELD.
THE GFS WAS TOO AGGRESSIVE WITH THE LOW LEVEL MOISTURE RETURN WITH
THE NAM DOING A LITTLE BETTER. MODELS DO NOT QUITE HAVE THE BOUNDARY
TO OUR SOUTH QUITE FAR ENOUGH SOUTH. THE NAM WAS DOING A LITTLE
BETTER HERE. ALSO MODELS HAD QPF TOO FAR NORTH BY 06Z WITH THE GFS...
CANADIAN AND THE SREF THE WORST OFFENDERS. AGAIN THE NAM WAS DOING
BETTER HERE.
TODAY/TONIGHT...MOST OF THE MODEL OUTPUT SHOWS A WEAK LEFT FRONT
QUADRANT OVER THE AREA BEGINNING NEAR 12Z AND MAINLY AFFECTING THE
SOUTHEAST HALF. A SMALL CLUSTER OF THUNDERSTORMS HAD DEVELOPED OVER
NORTHEAST NEW MEXICO AND THE PANHANDLE AREA. THIS LOOKS TO BE IN
RESPONSE TO SHORTWAVE TROUGH AND THE WEAK LEFT FRONT QUADRANT OF THE
JET. HOWEVER THAT DISSIPATED WITH ISOLATED THUNDERSTORMS DEVELOPING
OVER/NEAR THE EASTERN PORTION OF THE AREA.
THE NAM FOR THE MOST PART HAS THIS AREA DEPICTED WELL...ESPECIALLY
FOR THE JET. SO GOING BY THAT...WILL HAVE A SLIGHT CHANCE TO CHANCE
OF THUNDERSTORMS THROUGH MAINLY THE MORNING WITH IT POSSIBLY
LINGERING INTO EARLY AFTERNOON IN THE FAR EAST. STRATUS IS MOSTLY
OCCURRING OVER THE AREA AT THIS TIME WITH THE FOG CONFINED TO EASTERN
COLORADO. THIS MAKES SENSE WITH THIS BEING THE MAIN AREA OF LOW LEVEL
TRANSPORT OF MOISTURE AT THIS TIME. THE HRRR AND NAM INDICATE THE
BEST CHANCE OF FOG OVER THE WESTERN HALF OF THE AREA. A FEW SPOTS
ALSO REPORTING DRIZZLE AND SOUNDINGS WOULD INDICATE THAT WILL
CONTINUE INTO THIS MORNING. SO WILL HAVE AREAS OF FOG WITH PATCHY
DRIZZLE IN THE WESTERN HALF AND PATCHY FOG FURTHER EAST.
SOUTHERLY WINDS INCREASE INTO THE WINDY CATEGORY. GRADIENT DEFINITELY
SUPPORTS NEAR ADVISORY CRITERIA IN THE WEST BUT THERE THE 3 HOUR
PRESSURE FALLS ARE NOT THAT HIGH. GLD VWP DEFINITELY WOULD
SUPPORT WINDY. WILL RAISE WINDS TO NEAR ADVISORY IN THE FAR WEST.
NOW FOR THE PRECIPITATION CHANCES DURING THE AFTERNOON AND NIGHT.
SUBSIDENCE/DRYING OCCURS OUT EAST RATHER QUICKLY AFTER FIRST
SHORTWAVE. INSTABILITY AXIS...BEST HEATING...MID/UPPER LEVEL LIFT
AND SURFACE CONVERGENCE DEVELOPS NEAR OR OVER THE WESTERN PORTION OF
THE AREA. SO WILL GRADUALLY RAMP UP POPS DURING THE AFTERNOON. BEST
LIFT AND MOISTURE LOOK TO RESIDE OVER THE NORTH DURING THE NIGHT
AND HAVE INCREASED POPS OVER THE NORTH WITH LOWER POPS FURTHER
SOUTH. THUNDERSTORMS LOOK TO BE DONE BY 12Z. LOW LEVEL MOISTURE
INCREASES OVER THE EASTERN HALF TO TWO THIRDS AFTER 06Z. AT THIS TIME
MODELS INDICATING MOSTLY STRATUS. WILL INSERT FOG WITH THE GREATEST
CHANCE IN THE FAR EAST.
NOT A GOOD FEEL ON THE MAXES WITH THEM BEING DETERMINED BY THE
EXTENT OF THE STRATUS AND HOW LONG IT TAKES TO BURN OFF. IT IS
POSSIBLE THAT THICK CLOUD COVER WILL NOT BREAK UP UNTIL LATE
MORNING. SO TRENDED THE FORECAST COOLER.
SATURDAY/SATURDAY NIGHT...FOG WILL CLEAR OUT DURING THE MORNING.
MODELS NOT AGREEING WHERE DRYLINE ENDS UP...WHERE THE INSTABILITY
AXIS ENDS UP...WHERE THE CAP IS THE LEAST...AND SHORTWAVE DETAILS.
AT THIS TIME IT LOOKS LIKE THE DRY LINE ENDS UP NEAR OR A LITTLE
WEST OF THE COLORADO BORDER. ONE SHORTWAVE TROUGH EXITS THE EASTERN
PORTION OF THE AREA EARLY IN THE AFTERNOON WITH ANOTHER ONE
APPROACHING LATE IN THE AFTERNOON WITH THE BRUNT OF ITS LIFT COMING
THROUGH DURING THE NIGHT. MODELS ARE GENERATING QPF WHERE THERE IS
A STRONG CAP.
AS IT LOOKS NOW THE MAIN TIME FOR PRECIPITATION WILL WAIT TO BEGIN
UNTIL MID TO LATE EVENING. THE BEST CHANCE FOR THUNDERSTORMS WILL
BE EAST OF THE COLORADO BORDER...AND ESPECIALLY IN THE FAR EAST.
LOW LEVEL THERMAL FIELD IS MUCH WARMER THAN TODAYS. HOWEVER...IF
STRATUS/FOG LAST LONGER OR THE LEE TROUGH IS STRONGER/FURTHER WEST...
THE WINDS WILL BE MORE FROM AN EASTERLY DIRECTION AND NOT ALLOW FOR
AS BIG A WARMUP. KEPT THE WESTERN AREAS WARMER WITH COOLER MAXES
FURTHER EAST.
IN REGARDS TO FIRE...THE LOWEST RHS LOOK TO BE IN COLORADO AT THIS
TIME. HOWEVER...THAT IS WHERE THE LIGHTEST WIND FIELD IS. DUE TO A
LOT OF UNCERTAINTY...WAS NOT CONFIDENT ENOUGH TO THROW OUT A WATCH.
WILL HIGHLIGHT IN THE FIRE WEATHER FORECAST AND HWO.
SUNDAY/SUNDAY NIGHT...A LOT MORE DISAGREEMENT IN DETAILS SHOW UP IN
THIS PERIOD. CURRENT MODEL OUTPUT SUPPORTED THE GOING PRECIPITATION
FORECAST FOR THIS PERIOD AND LEFT IT ALONE. ALSO ONLY MADE SLIGHT
ADJUSTMENTS TO THE TEMPERATURE FORECAST AS WELL. P
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 235 AM MDT FRI MAY 24 2013
MEDIUM RANGE MODEL DIFFERENCES EMERGE EARLY IN THE EXTENDED
PERIOD...PARTICULARLY WITH REGARD TO AMPLITUDE OF UPPER FLOW
PATTERN. THE ECMWF IS MORE AMPLIFIED ON MONDAY WITH BOTH THE UPPER
RIDGE POSITIONED TO OUR EAST AND ALSO THE WESTERN CONUS UPPER
TROUGH. THE POSITION OF THESE FEATURES WILL PLACE OUR AREA IN
SOUTHWESTERLY FLOW ALOFT WITH THE LIKELIHOOD OF WEAK EMBEDDED
DIFFICULT TO TIME SHORTWAVES THAT COULD POTENTIALLY ENHANCE
PRECIPITATION DEVELOPMENT. BY TUESDAY THE PATTERN AMPLIFIES
FURTHER AND ECMWF CLOSES OFF AN UPPER LOW OVER THE SOUTHWEST
CONUS. GFS MAINTAINS AN OPEN WAVE AND SHIFTS IT EASTWARD WITH
NOTICEABLE HEIGHT FALLS OVER OUR AREA BY LATE TUESDAY AND
ESPECIALLY WEDNESDAY. THE NEW 00Z ECMWF HAS TRENDED THE DIRECTION
OF THE MORE PROGRESSIVE GFS AND OPENS UP THE SOUTHWEST CONUS UPPER
LOW RATHER THAN KEEP IT CLOSED AND SLOWLY MOVING IT EAST AS THE
12Z ECMWF INDICATED. STILL THE ECMWF IS CONSIDERABLY SLOWER THAN
THE GFS WITH THE EASTWARD PROGRESSION OF THIS TROUGH. THIS LEADS
TO A LOW CONFIDENCE FORECAST NEXT WEEK. GFS WOULD FAVOR A
POTENTIALLY WIDESPREAD PRECIPITATION / ORGANIZED CONVECTIVE EVENT
WEDNESDAY WHILE THE ECMWF SOLUTION WOULD SUPPORT A SIMILAR
SITUATION BY LATE WEDNESDAY / WEDNESDAY NIGHT INTO THURSDAY.
&&
.AVIATION....(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1118 PM MDT THU MAY 23 2013
STRATUS CONTINUES TO STREAM NORTH ACROSS THE AREA AND CIGS WILL BE
LOWERING AT BOTH KGLD AND KMCK THROUGH THE OVERNIGHT HOURS. IN
ADDITION...SOUTHEASTERLY SURFACE WINDS WILL GRADUALLY INCREASE...
WHICH WILL FAVOR STRATUS OVER FOG SO WILL NOT INCLUDE ANY VISIBILITY
RESTRICTIONS. ON FRIDAY...CIGS WILL BE SLOW TO LIFT WITH PERSISTENT
MOIST SOUTHEASTERLY FLOW. THUNDERSTORMS WILL BE POSSIBLE BY THE
AFTERNOON OR EARLY EVENING AT EITHER LOCATION.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...BRB
AVIATION...024
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1145 AM EDT FRI MAY 24 2013
.SYNOPSIS...
DRY AND COOL WEATHER CAN BE EXPECTED FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
LIGHT SHOWERS/DRIZZLE WILL CONTINUE TO DIMINISH THROUGH THE
AFTERNOON AS DRIER AIR WITH THE APPROACHING HIGH PRESSURE BEGINS
TO BUILD OVERHEAD. THE BIGGEST CONCERN FOR THE NEAR TERM IS THE
IMPACT CLOUD COVER WILL HAVE ON TEMPERATURES TODAY THROUGH THE
OVERNIGHT AND HOW THIS WILL FURTHER IMPACT FROST/FREEZE ACROSS THE
FORECAST AREA. THE MOST RECENT RUNS OF THE HRRR AND RUC SUGGEST THAT
MOISTURE TRAPPED UNDER THE LOW LEVEL INVERSION WILL STRUGGLE TO
MIX OUT TODAY...KEEPING CLOUD COVER OVER MUCH OF THE REGION LONGER
THAN ORIGINALLY ANTICIPATED. HAVE ALREADY LOWERED HIGH
TEMPERATURES A FEW DEGREES TODAY WITH THE CONTINUED COLD ADVECTION
AND CLOUD COVER. DEPENDING ON WHEN THE LOWER LEVELS DRY
OUT...TEMPERATURES MAY HAVE LITTLE TIME TO WARM BEFORE
NIGHTFALL...LEADING TO A MORE WIDESPREAD FREEZE. OR...AS THE RUC
SUGGESTS....CLOUDS COULD REMAIN OVER PORTIONS OF THE AREA THROUGH
MUCH OF THE NIGHT...ELIMINATING THE FROST/FREEZE POTENTIAL. AT
THIS POINT HOWEVER...FOLLOWED CLOSER TO NAM/GFS GUIDANCE AND
MAINTAINED CLEARING SKIES BY TONIGHT AND THUS HAVE MADE NO CHANGES
TO CURRENT PRODUCTS.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
DRY SFC HIGH PRES UNDR NW FLOW ALOFT WL MAINTAIN COLD TEMPS
THROUGH THE WEEKEND. EXPECT READINGS OF 10 TO 15 DEGREES UNDR THE
AVERAGES WITH FROST POTENTIAL AGAIN ON SATURDAY NGT.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
SFC HIGH PRES IS EXPECTED TO MAINTAIN DRY WEA UNTIL A WARM FRONT
INCREASES PCPN CHCS FOR WEDNESDAY AND THURSDAY. INITIALLY COLD TEMPS
WL MODERATE TO...AND THEN ABOVE SEASONAL LVLS AS SLY FLOW RESUMES
BY MID WEEK.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
EARLY MRNG IFR AND MVFR ST AND STRATOCU CEILINGS ARE EXPECTED TO
IMPROVE AS THE DAY PROGRESSES WITH DRY ADVCTN GRADUALLY INCRSG T/DP
SPREADS DESPITE COLD FLOW. WIND GUSTS TO ABOUT 22 KTS CAN BE EXPECTED
IN THE SHALLOW MIXING REGIME. THAT POTENTIAL WL CEASE WITH
DECOUPLING THIS EVE.
.OUTLOOK.../SATURDAY THROUGH TUESDAY/...
HIGH PRESSURE WL MAINTAIN VFR THROUGH EARLY NXT WEEK.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...FREEZE WARNING FROM 3 AM TO 8 AM EDT SATURDAY FOR MDZ001.
OH...FROST ADVISORY FROM 3 AM TO 8 AM EDT SATURDAY FOR OHZ039>041-
048>050-057>059-068-069.
PA...FROST ADVISORY FROM 3 AM TO 8 AM EDT SATURDAY FOR PAZ020-021-
029-031-073-075.
FREEZE WARNING FROM 3 AM TO 8 AM EDT SATURDAY FOR PAZ007>009-
013>016-022-023-074-076.
WV...FROST ADVISORY FROM 3 AM TO 8 AM EDT SATURDAY FOR WVZ001>004-
012-021-022.
FREEZE WARNING FROM 3 AM TO 8 AM EDT SATURDAY FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
702 AM EDT FRI MAY 24 2013
.AVIATION...
//DISCUSSION...
DEEP COLUMN TROUGHING AND COLD AIR ADVECTION HAS TEAMED TOGETHER TO
ALLOW A STRATUS BLANKET TO EXPAND SOUTHWARD INTO THE CENTRAL GREAT
LAKES. A STRAIGHT NORTHERLY WIND TRAJECTORY WILL MAINTAIN THE VERY
AGGRESSIVE MOVEMENT. THE SHALLOW SATURATION MAKES IT EXTREMELY
DIFFICULT FOR THE NWP TO CATCH UP WITH THE TRENDS...WITH THE CLOUD
FORECASTING DISTILLING DOWN TO A NOWCAST OF LATEST SATELLITE
IMAGERY. EXPECT A INCREASING DIABATIC HEATING TERM TO PROMOTE
MIXING AND A OVC TO BKN TREND BY LATE MORNING. REGIONAL RAOBS FROM
LAST EVENING RECORDED THE AMOUNT OF DRY AIR THAT IS NEARBY...SO ONCE
THE DRY AIR BEGINS TO EXERT AN INFLUENCE AT ANY ONE AREA EXPECT A
DECIDED MOVE TO CLEAR AND SUNNY SKIES. IN OTHER WORDS...THERE IS LOW
CONFIDENCE IN TIMING.
AT DTW...LINEAR INTERPOLATION OF EXISTING CLOUD DECK IS SET TO MOVE
INTO THE TERMINAL PRIOR TO THE START OF THE TAF PERIOD. LOW
CONFIDENCE EXISTS IN WHEN TO END THE MVFR CEILINGS...BUT A SAFE
ESTIMATE WILL BE LATE MORNING WITH AN INCREASE IN DAYTIME SURFACE
HEATING.
//DTW THRESHOLD THREATS...
* LOW CONFIDENCE THAT CEILING HEIGHTS OF LESS THAN 5000FT WILL
PLAGUE THE TERMINAL THROUGH THE MORNING HOURS.
&&
.PREV DISCUSSION...ISSUED 340 AM EDT FRI MAY 24 2013
SHORT TERM...TODAY AND TONIGHT
THE WEATHER UP FOR DISCUSSION IS THE PROSPECTS FOR OVERCAST SKIES
TODAY AS AN OPAQUE BLANKET OF 030-035 FT STRATUS IS AGGRESSIVELY
DIVING SOUTHWARD ACROSS LAKE HURON. TRAJECTORY OF CLOUD DECK IN
ADDITION TO THE ORIENTATION OF THE WESTERN EDGE ALIGNS WELL WITH THE
AXIS OF MAXIMUM 925-850MB COLD AIR ADVECTION AND THE DEPRESSION OF
THE LONGWAVE TROUGH AXIS. NWP DATA IS VIRTUALLY VOID OF CLOUD...A
RESULT OF INADEQUATE VERTICAL RESOLUTION WITHIN THE MODELS. WHILE
THE CLOUD IS COMPLETELY OPAQUE IT IS UNDOUBTEDLY A SHALLOW LAYER OF
MOISTURE THAT IS LIKELY TRAPPED WITHIN THE BASE OF THE INVERSION
AT/AROUND 900-890MB. RUC SOUNDINGS SHOW SATURATION AT THIS
ZONE...BUT THE SOUNDING STRUCTURE ITSELF DOES NOT INSPIRE MUCH
CONFIDENCE AS IT IS THE WRONG PROFILE. GIVEN THE TRUE NORTHERLY
TRAJECTORY...HAVE DECIDED TO INTRODUCE OVERCAST CONDITIONS FOR MUCH
OF THE CWA THROUGH THE MORNING HOURS. IT WILL BE DIFFICULT TO
PINPOINT ANY WEST EDGE OF THE CLOUDS GIVEN DEGREE OF DRY AIR
IMMEDIATELY TO THE WEST. PATTERN RECOGNITION SUGGESTS ENTRAINMENT AT
THE EDGE SHOULD AID DIURNAL MIXING TO FORCE STRATUS TO GO BROKEN BY
LATE MORNING...EVENTUALLY CLEARING OUT FOR THE AFTERNOON.
LOWERED MAX TEMPERATURES FOR MANY AREAS DUE TO THE CLOUD AND STEADY
COLD AIR ADVECTION. EXPECT TEMPERATURES TO EVENTUALLY REACH 60-61
DEGREES ACROSS THE SOUTH AND SAGINAW VALLEY VERY LATE IN THE DAY.
OTHERWISE TEMPERATURES ARE GOING TO STRUGGLE TO REACH THE LOWER 50S
IN THE THUMB.
FOR TONIGHT...THE COMPACT VORT OVER NORTHERN MANITOBA WILL GET
SQUEEZED WITH A ROGUE VORTICITY STREAMER OFF OF THE PACNW ANOMALY
MERGING OVER THE WESTERN GREAT LAKES. THIS WILL OCCUR DOWN THE FRONT
EDGE OF THE CENTRAL CONUS RIDGE...ALLOWING FOR A VERY HEALTHY
AGEOSTROPHIC RESPONSE AND STRIPE OF FRONTOGENESIS VERY LATE. ANY
SIGNIFICANT TEMPERATURE GRADIENT WILL RESIDE WELL WEST OF LOWER
MICHIGAN WHICH IS WHERE THE PRECIPITATION RESPONSE WILL OCCUR.
REGARDLESS...INCREASING CLOUDS LATE WILL ESTABLISH A FLOOR ON
MINIMUM TEMPERATURES TONIGHT.
LONG TERM...SATURDAY THROUGH THURSDAY
THE OVERALL PATTERN ACROSS NORTH AMERICA THIS WEEKEND WILL FEATURE A
QUASI OMEGA BLOCK. SHORT WAVE ENERGY NOW SHOWN ROTATING INTO NRN
MANITOBA IS FORECAST TO TRACK ACROSS THE ERN GREAT LAKES AND MID
ATLANTIC EARLY SATURDAY...LEADING TO DEEPENING OF AN UPPER LOW
ROTATING ACROSS NEW ENGLAND. LOWER MI WILL BE LOCATED BETWEEN THIS
SYSTEM AND AMPLIFYING MID LEVEL RIDGING ACROSS THE NRN PLAINS/UPPER
MS VALLEY. THIS WILL PLACE THE FORECAST AREA WITHIN A STRONGLY
CONFLUENT UPPER FLOW WITH PERSISTENT HIGH PRESSURE AT THE SURFACE.
THE RESIDENT AIRMASS ACROSS THE GREAT LAKES WILL BE COOL AND VERY
DRY. TEMPS ON SATURDAY SHOULD ONLY RISE TO THE LOW 60S OVER MUCH OF
THE FORECAST AREA WITH 850MB TEMPS HOVERING AROUND +2C. THE AIRMASS
WILL MODERATE DURING THE COURSE OF THE WEEKEND...WITH HIGHS EXPECTED
TO BE AROUND 70 BY MEMORIAL DAY. GIVEN THE DRY AIRMASS AND LIGHT
WINDS...NIGHTTIME LOWS WILL BE QUITE CHILLY THIS WEEKEND /30S AND
40S/.
A SEASONALLY STRONG 140+ KNOT UPPER JET IS FORECAST DIVE INTO THE
PACIFIC NORTHWEST EARLY NEXT WEEK...LEADING TO LONG WAVE TROUGH
AMPLIFICATION ACROSS THE WRN US AND A BUILDING SUBTROPICAL RIDGE
ACROSS THE SERN US. THIS WILL ALLOW THE MID LEVEL RIDGE TO BECOME
MORE PROGRESSIVE AND PASS EAST OF LOWER MI TOWARD MIDWEEK...ALLOWING
A SFC WARM FRONT TO LIFT ACROSS THE REGION FROM THE SOUTHWEST. THIS
WARM FRONT WILL ADVECT A WARM...MOIST AND UNSTABLE AIRMASS INTO THE
FORECAST AREA. THE GFS CONTINUES TO BRING THIS WARM FRONT THROUGH
FASTER THAN THE OTHER MODEL SOLUTIONS /SUGGESTING CONVECTION AS
EARLY AS MON NIGHT/. THE GFS HAS SOME OBVIOUS CONVECTIVE FEEDBACK
ISSUES DUE TO POTENTIAL MCS DEVELOPMENT OVER THE PLAINS. THE GFS IS
ALSO LESS AMPLIFIED WITH THE LONG WAVE TROUGH OVER THE WRN US. GIVEN
THE STRENGTH OF THE POLAR JET AND POTENTIAL PHASING WITH THE
SUBTROPICAL JET...THE MORE AMPLIFIED ECMWF REMAINS THE PREFERRED
SOLUTION. THIS SUGGESTS THE BETTER CHANCES FOR CONVECTION WILL HOLD
OFF UNTIL THE TUES NIGHT/WED TIME FRAME. DESPITE THIS UNCERTAINTY...
THE OVERALL TREND NEXT WEEK WILL BE FOR WARMER AND MORE HUMID
CONDITIONS WITH INCREASING CHANCES FOR THUNDERSTORMS.
MARINE...
UNSEASONABLE CONDITIONS ARE IN PLACE OVER THE CENTRAL GREAT LAKES
TODAY AS COLD AIR ADVECTION IS ONGOING WITHIN A DEEP TROUGH AXIS.
EFFICIENT NORTHERLY FLOW AND A LONG FETCH OVER THE WATERS WILL
SUSTAIN HIGH WAVE ACTIVITY FROM SAGINAW BAY DOWN TO PORT HURON.
RECENT WATER TEMPERATURE READINGS FROM THE BUOYS SUGGESTS THAT
CONDITIONS WILL BE SOLIDLY IN THE NEUTRAL REGIME OUT OVER THE OPEN
LAKE WHICH IS ATYPICAL FOR LATE MAY. IN FACT...CONDITIONS ARE
UNSTABLE FOR SAGINAW BAY WITH WATER TEMPERATURE READINGS SUGGESTING
LSTS ARE AT AROUND 13 TO 14 C VS AN 850MB TEMPERATURE THAT WILL BE
DIPPING DOWN TO -4C BY 12Z THIS MORNING. WILL EXPAND THE ADVISORY TO
INCLUDE INNER SAGINAW. CONDITIONS ARE MORE MARGINAL ON LAKE ST CLAIR
AND LAKE ERIE. WILL GIVE RESPECT TO PEAK OF THE COLD AIR ADVECTION
THAT WILL OCCUR THIS MORNING FOR THE SOUTHERN ZONES AND EXTEND THE
SMALL CRAFT FOR THEM AS WELL. THE STABLE SURFACE ANTICYCLONE WILL
BUILD INTO THE CENTRAL GREAT LAKES TONIGHT BRINGING A RETURN OF MUCH
MORE FAMILIAR STABLE SEASON MARINE WEATHER.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...
SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM PORT AUSTIN TO PORT
HURON...UNTIL 8 PM FRIDAY.
SMALL CRAFT ADVISORY...OUTER SAGINAW BAY...UNTIL 6 PM FRIDAY.
SMALL CRAFT ADVISORY...INNER SAGINAW BAY...UNTIL 10 AM FRIDAY.
LAKE ST CLAIR...
SMALL CRAFT ADVISORY...UNTIL 4 PM FRIDAY.
MI WATERS OF LAKE ERIE...
SMALL CRAFT ADVISORY...UNTIL 4 PM FRIDAY.
&&
$$
AVIATION.....99
SHORT TERM...CB
LONG TERM....SC
MARINE.......CB
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1108 AM EDT FRI MAY 24 2013
.SYNOPSIS...
MUCH COOLER AIR TURNS DRIER AND TODAY PROGRESSES. CHILLY HIGH
PRESSURE TAKES CHARGE TONIGHT INTO SATURDAY. WARM FRONT IN LOWER
OHIO VALLEY GRADUALLY SHIFTS NE TOWARD MEMORIAL DAY AND TUESDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
STRATOCU HANGING TOUGH ATTM ACROSS MUCH OF THE AREA...WITH AREAS
ALONG AND E OF I79 CORRIDOR MAINLY OVC. BUMPED POPS UP TO LKLY FOR
ANOTHER HR OR TWO ACROSS N MTNS FOR SOME SHRA. SNOWSHOE HANGING
ARND 34F...HOWEVER...MOISTURE DEPTH ONLY REACHES UP TO ABOUT -3F
SO KEPT THINGS LIQUID. TRIED TO DELAY SCOURING OUT OF LLVL
MOISTURE PER RUC TRENDS...PRIMARILY ACROSS THE MTNS. SHOULD SEE
MORE STREAKY NATURE TO FLAT STRATOCU ACROSS THE LOWLANDS WITH MORE
SUNSHINE BEING OBSERVED.
KNOCKED TEMPS DOWN A COUPLE DEGREES FOR THIS AFTN PER LATEST
TRENDS AND LAMP GUIDANCE ESPECIALLY ACROSS THE HIGH TERRAIN.
WILL BE FIGURING OUT IF FROST ADV NEEDS EXPANDING FOR AFTN
PACKAGE. SFC HIGH BUILDS IN OVER NIGHT ALLOWING WINDS AT SFC TO GO
CALM...BUT H925 WINDS STAY UP ARND 20 KTS. ALSO OF CONCERN IS
STRATOCU TRYING TO REDEVELOP ACROSS N MTNS AND ADJ LOWLANDS
TONIGHT PER RUC AND TO A LESSER DEGREE HI RES WRF MDLS. NAM KEEPS
ENTIRE COLUMN DRY.
PREVIOUS DISCUSSION BELOW...
FINAL COLD FRONT PUSHING ACROSS CWA AT THIS TIME...AT 08Z IT WAS
STRETCHING FROM CLARKSBURG SOUTH TO AROUND THE WV/VA/KY
INTERSECTION. STILL SEEING SOME GUSTY WINDS ALONG AND JUST BEHIND
THE FRONT...WHICH SHOULD SUBSIDE SOME EARLY THIS MORNING BEFORE
PICKING BACK UP WITH MIXING TODAY. DEWPOINTS ALSO DROPPING INTO
THE UPPER 30S BEHIND THE FRONT...AND EXPECT SKIES TO GRADUALLY
CLEAR FROM WEST TO EAST ACROSS THE FORECAST AREA TODAY AS THE
MOISTURE CONTINUES EAST AND COOL HIGH PRESSURE BEGINS TO BUILD
OVER LAKE MICHIGAN. HIGHS TODAY WILL BE 10-15 DEGREES COOLER THAN
YESTERDAY...MAV/MET FAIRLY CLOSE...AND SETTLED GENERALLY BETWEEN
THE TWO.
THE COOL HIGH PRESSURE WILL MOVE OVER FORECAST AREA TONIGHT...WITH
AN UNSEASONABLY CHILLY START TO THE MEMORIAL DAY WEEKEND. MAV A BIT
COOLER THAN THE MET...AND AGAIN SETTLED IN BETWEEN. THIS GIVES
AROUND...TO JUST BELOW FREEZING FOR THE NORTHERN MOUNTAINS...SO
OPTED FOR A FREEZE WARNING THERE. A BIT HARDER TO FIGURE OUT WHERE
FROST MAY FORM DUE TO THE WARM...WET GROUND...CONTINUED BREEZE
OVERNIGHT...AND RELATIVELY SHORT NIGHT TO BOOT. DECIDED ON A FROST
ADVISORY ACROSS NORTHERN TWO TIERS OF COUNTIES...WITH CONTINUED
MENTION IN HWO FOR THE REST OF THE CWA. DESPITE TEMPERATURES BEING
COLD ENOUGH IN PARTS OF THE SOUTHERN MOUNTAINOUS COUNTIES...THINKING
IT WILL REMAIN MIXY ENOUGH TO NIX ANY FROST FORMATION EVEN AT 34-36
DEGREES. AT ANY RATE...CAMPERS CELEBRATING THE UNOFFICIAL START OF
SUMMER...OR THOSE WITH EARLY MORNING SOCCER OR BASEBALL WILL WAKE UP
TO A CHILLY SATURDAY MORNING.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
MOST NOTABLE CHANGES MADE TOWARD MEMORIAL DAY. TIMING THE EVENTUAL
NORTHEAST MOVEMENT AS A WARM FRONT...OF THE FRONTAL ZONE SETTING UP
OVER THE LOWER OHIO VALLEY INTO THE TENNESSEE VALLEY IS A
CHALLENGE.
ONE DISTURBANCE RIDES FROM NW TO SE OVERNIGHT SATURDAY NIGHT INTO
EARLY SUNDAY...BUT WILL KEEP ANY SPOTTY LIGHT RAIN TO OUR SW-S. DID
HAVE MORE CLOUDS OVER OUR SOUTHERN COUNTIES IN THE FORM OF SOME
PATCHY MID/HIGH CLOUDS. FURTHER NORTH...SATURDAY NIGHT WILL STILL
BE MOSTLY CLEAR AND CHILLY ESPECIALLY FOR NORTHERN AND CENTRAL WEST
VIRGINIA. DID INCLUDE SOME FROST IN OUR CENTRAL WV MOUNTAIN
COUNTIES FOR THE EARLY DAWN SUNDAY.
WILL INCREASE POPS ON MONDAY...THINKING THE WARM FRONT WILL BEGIN
LIFTING NORTHEAST...AT LEAST OVER THE MIDWEST...LEAVING US
VULNERABLE DOWNSTREAM. HOW ACTIVE THE WARM FRONT IS...IS ANOTHER
DILEMMA.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
HIGH PRESSURE REMAINS IN CONTROL TO AT LEAST EARLY WEDNESDAY
PROVIDING DRY WEATHER WITH A SLOW WARMING TREND.
ANOTHER MID LEVEL SHORTWAVE WILL MOVE THROUGH SUNDAY NIGHT FOR LOW
CHANCE FOR RAIN SHOWERS INTO MONDAY.
A WARM FRONT DEVELOPS AS IT APPROACHES THE REGION ON MONDAY. AS A
RESULT...THERE WILL BE A CHANCE OF SHOWERS AND STORMS MONDAY AND
TUESDAY...MAINLY DURING THE AFTERNOON AND EVENING HOURS.
FOR SATURDAY...TEMPERATURES SHOULD BE NEAR NORMAL WITH DAYTIME
HIGHS IN THE 70S ACROSS LOWLANDS...WITH 60S ACROSS THE HIGHER
ELEVATIONS. TEMPERATURES WILL CONTINUE TO CLIMB IN THE UPPER TO
MID 80S BY THE END OF THE WEEK. LOWS WILL RANGING IN THE 60S.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
FOR THE MOST PART SHOWERS HAVE ENDED ACROSS THE FORECAST
AREA...WITH MVFR CEILINGS REMAINING ACROSS THE LOWLANDS AND LOW
MVFR TO IFR IN THE MOUNTAINS. CEILINGS SHOULD GRADUALLY IMPROVE TO
VFR FROM WEST TO EAST TODAY. BREEZY TO GUSTY WINDS WILL CONTINUE
TODAY OUT OF THE N/NW...DECREASING SOME AS THE SUN SETS TONIGHT.
DRY AIR FILTERING IN SHOULD KEEP WIDESPREAD FOG CHANCES AT BAY
ACROSS THE LOWLANDS TONIGHT...AND WINDS IN THE HIGHER TERRAIN
SHOULD ALSO KEEP ANY DENSE FOG AWAY. WITH THAT SAID...VERY CHILLY
AIR OVER RELATIVE WARM WATER IN THE RIVERS COULD PRODUCE SOME
LOCALIZED MVFR FOG BY EARLY SATURDAY MORNING IN RIVER VALLEYS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z SATURDAY...
FORECAST CONFIDENCE...HIGH.
ALTERNATE SCENARIOS: TIMING OF DISSIPATION OF MVFR/IFR CEILINGS
THIS MORNING MAY VARY A COUPLE OF HOURS.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY M H M H H H H H H H H H
EKN CONSISTENCY L H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H M H H H H H H H H H H
AFTER 12Z SATURDAY...
IFR CONDITIONS POSSIBLE IN FOG EARLY SATURDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FROST ADVISORY FROM 2 AM TO 8 AM EDT SATURDAY FOR WVZ009>011-
019-020-028>032-039-040.
FREEZE WARNING FROM 2 AM TO 8 AM EDT SATURDAY FOR WVZ037-038-
046-047.
OH...FROST ADVISORY FROM 2 AM TO 8 AM EDT SATURDAY FOR OHZ066-067-
075-076.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...MZ/30
SHORT TERM...KTB
LONG TERM...ARJ
AVIATION...MZ
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
855 AM EDT FRI MAY 24 2013
.SYNOPSIS...
HIGH PRESSURE OF CANADIAN ORIGIN WILL BUILD INTO THE REGION TODAY
PROVIDING DRY WEATHER AND CONSIDERABLY COOLER TEMPERATURES. THIS
RIDGE OF HIGH PRESSURE WILL SLIDE EAST ACROSS THE REGION...OFFERING
DRY CONDITIONS THROUGH THE HOLIDAY WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOW CLOUDS CONTINUE TO MOVE SOUTH ACROSS THE REGION. EXPECT THIS
TO EVENTUALLY MIX OUT WITH THE AFTERNOON BECOMING MAINLY SUNNY.
UPDATED TO LINGER CLOUDS A LITTLE LONGER BASED ON OBSERVATIONAL
TRENDS AND LATEST RAP FORECASTS. TEMPERATURES LOOK REASONABLE
BASED ON 12Z SOUNDING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
IN NW FLOW PATTERN...SFC HIGH PRESSURE TO BUILD SE BECOMING CENTERED
OVER THE REGION SATURDAY. LIGHT WINDS...AND CLEAR SKIES WILL LEAD TO
A FAVORABLE RADIATIONAL COOLING SETUP. LOW TEMPERATURES TO RANGE
FROM THE MID/UPR 30S FAR EAST TO THE LOWER 40S WEST. HAVE INCLUDED A
MENTION OF PATCHY FROST IN THE FAR EASTERN COUNTIES. WILL CONTINUE
TO HIGHLIGHT THIS POSSIBILITY OF FROST IN THE HWO PRODUCT.
EXPECT MAINLY HIGH LEVEL CLOUDS TO SPILL OVER THE UP STREAM RIDGE
WITH SKIES BECOMING PARTLY CLOUDY OVER THE SW SATURDAY. WAA PRECIP
AND DEEPER MOISTURE EXPECTED TO REMAIN TO OUR SW. TEMPERATURES WILL
BEGIN TO MODERATE WITH HIGHS STILL 8 TO 10 DEGREES BELOW NORMAL.
EXPECT HIGHS TO RANGE FROM THE MID 60S NE TO THE UPR 60S SW.
SATURDAY NIGHTS LOWS TO CONTINUE BELOW NORMAL RANGING FROM THE LOWER
40S NE TO ABOUT 50 SW...WHERE MORE CLOUDS ARE EXPECTED.
A DISTURBANCE ROUNDING THE RIDGE WILL RESULT IN PRECIP SPILLING SE
INTO THE LOWER OHIO VALLEY. IT IS NOT OUT OF THE QUESTION THAT A
RAIN SHOWER SPILL INTO OUR FAR SW SUNDAY BUT WITH BEST LIFT AND MSTR
TO OUR SW...WILL MAINTAIN A DRY FCST. TEMPERATURES WILL CONTINUE TO
MODERATE WITH HIGHS RANGING FROM THE UPR 60S NE TO ABOUT 70 SW.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
UPPER LEVEL RIDGE IN THE CENTRAL CONUS WILL PREVAIL WITH GENERAL
NORTHWEST FLOW IN THE OHIO VALLEY. GFS IS SHOWING A S/W
UNDERCUTTING H5 RIDGE AND BRINGING PRECIPITATION TO THE REGION
MONDAY. THIS APPEARS TO BE CONSISTENT FROM YESTERDAYS FORECAST BUT
THE EUROPEAN IS ALSO CONSISTENT WITH SHOWING THIS FEATURE MUCH
FURTHER SOUTHWEST AS AN ELEVATED CONVERGENT BAND AT THIS TIME.
THE EUROPEAN PERMITS THIS UNDERCUTTING OF THE ESTABLISHED H5 RIDGE
ON TUESDAY AND IS SHOWING A MORE TRADITIONAL WARM FRONTAL FEATURES
IN THE OHIO VALLEY...ALSO SUPPORTED BY THE GFS AND CANADIAN MODEL.
THIS FRONT IS VERY BROAD IN NATURE AND FORECAST IS UNCERTAIN AS TO
IF THERE WILL BE ENOUGH OF A GRADIENT TO HELP FORCE SHOWERS IN A
SOMEWHAT UNFAVORABLE UPPER LEVEL PATTERN...UNDERNEATH THE AXIS OF
THE H5 RIDGE.
UPPER LEVEL FLOW IS SHOWING A BROADENING OF THE H5 RIDGE AS IT MOVES
OVER THE EASTERN THIRD OF THE COUNTRY. AM CONTINUING THE INCREASED
POPS EXPECTING MID LEVEL DISTURBANCES TO UNDERCUT THE RIDGE AFTER
MONDAY BUT INCREASING THROUGH THE WEEK.
EXPECT A GRADUAL WARM UP EACH DAY...STARTING IN THE UPPER 60S TO
AROUND 70 SUNDAY...WARMING TO NEAR 80/LOW 80S BY WED...POSSIBLY
REACHING MID 80S BY THURSDAY. PM LOWS WILL BE COMFORTABLY COOL
AROUND 50 MON MORNING UNDER A DRY AIRMASS AND THEN WARM PAST THE
CLIMATOLOGICAL NORMS TO REACH MID 60S BY THE LATTER PART OF THE WEEK.
&&
.AVIATION /13Z FRIDAY THROUGH TUESDAY/...
CLOUDS WILL LINGER ACROSS THE TERMINALS FOR SEVERAL MORE HOURS
WITH BRIEF PERIODS OF MVFR CEILINGS POSSIBLE. CLOUDS SHOULD
DIMINISH AFTER 18Z. NORTH WINDS MAY BECOME GUSTY THROUGH THE DAY.
WINDS WILL BECOME LIGHT AFTER 00Z SATURDAY AS HIGH CLOUDS BEGIN TO
MOVE IN ON A NORTHWESTERLY FLOW ALOFT. THE LIGHT WINDS MAY ALLOW
MIST TO FORM AT LUK LATE TONIGHT. CVG CAN EXPECT MID AND HIGH
CLOUDS AND LIGHT EAST WINDS AFTER 12Z SATURDAY.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...AR
NEAR TERM...
SHORT TERM...AR
LONG TERM...FRANKS
AVIATION...
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
648 AM CDT FRI MAY 24 2013
.AVIATION...
THE TAF FORECAST REMAINS NEBULOUS FOR TODAY BEGINNING THIS
MORNING. LOW CIGS AT KCDS WILL LIKELY DISSIPATE BY LATE MORNING
AND THESE CIGS ARE NOT ANTICIPATED TO AFFECT KLBB. THUNDERSTORMS
MAY DEVELOP THIS AFTERNOON AT BOTH TAF SITES BUT UNCERTAINTY IS
VERY HIGH SO A PROB30 MENTION WAS PLACED IN THE TAFS FOR NOW.
&&
.PREV DISCUSSION... /ISSUED 440 AM CDT FRI MAY 24 2013/
SHORT TERM...
OVERALL CHANCES OF CONVECTION WILL BE LESS FAVORABLE TODAY THAN
YESTERDAY. THERE IS AN OVERALL LACK OF FORCING BOTH LARGE AND AT THE
MESOSCALE LEVEL. UPPER LEVEL JET WINDS WILL UNDERGO A SIGNIFICANT
WEAKENING WITH A LACK OF A FOCUSED AREA OF UPPER LEVEL DIVERGENCE.
SOUTHWEST FLOW ALOFT WILL CONTINUE TO PERSIST OVER THE REGION BUT
THERE ARE NO DISCERNIBLE SHORT WAVES WITH THE FLOW FOR THIS
AFTERNOON. ANY WELL DEFINED LOW LEVEL BOUNDARY WILL BE WELL AWAY
FROM THE REGION WITH LITTLE TO NO LOW LEVEL FOCUS RESOLVED BY MODEL
SOLUTIONS. THE ONLY LOW LEVEL BOUNDARY MAY BE A LEFT OVER CONVECTIVE
BOUNDARY FROM CONVECTION EARLY THIS MORNING. OTHERWISE...THE ONLY
LOW LEVEL ENHANCEMENT MAY BE ALONG THE EDGE OF THE CAPROCK WITH
SOUTHEASTERLY WINDS. FURTHERMORE...ISENTROPIC SURFACES WILL BE
COMPOSED OF DOWNGLIDE.
THERE WILL BE NO SHORTAGE OF ATMOSPHERIC INSTABILITY. INSTABILITY
WILL BALLOON TO BETWEEN 2000-3000 J/KG WITH MAXIMUM VALUES OVER THE
ROLLING PLAINS WHERE MOISTURE IS DEEPEST. THE RAP EVEN SHOWS AN
ASTOUNDING 6000 J/KG OF SURFACE BASED CAPE BY THE AFTERNOON. SURFACE
DEW POINTS ARE NOT EXPECTED TO MIX OUT AS MUCH AS THEY DID ON
THURSDAY. SOUTHEAST WINDS WILL KEEP SURFACE DEW POINTS IN JUICY
TERRITORY RANGING FROM UPPER 50S TO MID 60S. PRECIPITABLE WATER
VALUES MAINTAIN RESPECTABLE VALUES BETWEEN 1.00 AND 1.25 INCHES.
HODOGRAPHS DEPICT GOOD TURNING IN LOW LEVELS BUT WIND SPEEDS ARE
FAIRLY LIGHT THROUGH MID LEVELS. THIS IS ALSO REFLECTED IN DEEP
LAYER SHEAR PROGS. SHEAR VECTORS FROM 0-6KM ARE ON THE ORDER OF ONLY
25-30KT. THIS WOULD LEAD TO FAIRLY SLOW STORM MOTIONS ALLOWING FOR A
DELUGE OF RAINFALL. OVERALL...CONVECTION LOOKS TO BE POORLY
ORGANIZED FOR TODAY. MODELS ARE ALSO INITIATING BY LATE IN THE
MORNING WHICH SEEMS EQUIVOCAL GIVEN THAT THE ATMOSPHERE WILL
REMAINED CAPPED UNTIL THE EARLY AFTERNOON AMONG OTHER REASONS
DISCUSSED ABOVE. LASTLY...WITH DEW POINTS NOT ANTICIPATED TO MIX OUT
NEARLY AS MUCH TODAY...TEMPERATURES WILL BE SIGNIFICANTLY COOLER
THIS AFTERNOON WITH MOSTLY 80S FORECAST. JDV
LONG TERM...
SOUTHWEST FLOW ALOFT EXPECTED TO REMAIN OVER THE SOUTH PLAINS
REGION THROUGH THE MIDDLE OF THE COMING WEEK. MOISTURE FLOW WILL
CONTINUE NORTHWARD WITH PRECIPITABLE WATER VALUES HOLDING IN
EXCESS OF AN INCH MORE OR LESS OVER THE CENTER OF THE AREA...LESS
WEST AND MORE EAST OF COURSE. THE SURFACE DRY-LINE WILL LIKELY
SLOSH MOSTLY BETWEEN THE WESTERN AND EASTERN SOUTH PLAINS DURING
THIS PERIOD...WHILE PRECISE LOCATIONS AT PEAK AFTERNOON HEATING
PERIODS REMAINS UNCERTAIN. INSTABILITY LEVELS ALSO EXPECTED TO
HOLD IN THE 1000-2000 JOULES PER KILOGRAM RANGE. WEAK EJECTING
DISTURBANCES MAY PROVIDE ENOUGH LIFT AT TIMES...WHILE WEAKLY
CONVERGENT LOW LEVEL FLOW ALSO COULD GENERATE LOW COVERAGE THUNDER
CHANCES THROUGH TUESDAY.
A STRONGER TROUGH STILL SEEMS LIKELY TO EJECT LATE WEDNESDAY AND
THURSDAY...PERHAPS IN TWO OR MORE PARTS LIKE THE GFS OR AS A
STRONGER TROUGH OR UPPER LOW LIKE THE ECMWF. EITHER WAY SHOULD
SUPPORT MORE BACKED UPPER FLOW AND EVEN DEEPER MOISTURE WEDNESDAY
AND OR THURSDAY AND MAY END UP WITH A MORE WIDESPREAD SEVERE
WEATHER THREAT AS WELL. THIS IS A STRONG ENOUGH AND CONSISTENT
ENOUGH SIGNAL FOR NOW TO RAISE THUNDERSTORM MENTION INTO THE
CHANCE CATEGORY WEDNESDAY. TEMPERATURES SHOULD WARM A BIT ABOVE
NORMAL LATE IN THE WEEKEND AND EARLY NEXT WEEK...WHILE WINDS
SHOULD INCREASE BY MID-WEEK WITH THE PASSING UPPER LOW OR LOW
PRESSURE TROUGH. RMCQUEEN
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 84 60 84 60 93 / 30 30 20 20 20
TULIA 83 62 83 60 92 / 30 30 20 20 10
PLAINVIEW 83 63 83 61 91 / 30 30 20 20 10
LEVELLAND 85 64 84 62 92 / 30 30 20 20 10
LUBBOCK 83 65 83 63 92 / 30 30 20 20 10
DENVER CITY 85 64 84 61 92 / 30 30 20 20 10
BROWNFIELD 85 65 84 62 92 / 30 30 20 20 10
CHILDRESS 83 66 85 66 93 / 30 30 20 20 10
SPUR 82 66 82 63 91 / 30 30 20 20 10
ASPERMONT 85 67 84 66 92 / 40 40 20 20 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
01/99/99
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
340 PM EDT FRI MAY 24 2013
.SYNOPSIS...
19Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUE TO SHOW AN ACTIVE UPPER
LEVEL PATTERN IN PLACE OVER THE CONUS. LONGWAVE PATTERN IS DOMINATED
BY DEEP TROUGHS ALONG BOTH THE PACIFIC AND ATLANTIC COASTS WHILE A
LONGWAVE RIDGE AXIS BISECTS THE CONTINENT OVER THE CENTRAL PLAINS.
OUR FORECAST AREA RESIDES AT THE BASE OF THE EASTERN CONUS TROUGH.
A STRONG SHORTWAVE EMBEDDED WITHIN THIS TROUGH IS NOW DROPPING
SOUTHEASTWARD OVER THE MID-ATLANTIC/CAROLINAS. THIS ENERGY WILL NOT
ONLY ACT TO CLOSE OFF A POTENT UPPER LOW OFF THE NEW ENGLAND
COAST...BUT ITS MOMENTUM WILL ALSO HELP DRIVE A LATE SEASON COLD
FRONT DOWN AND THROUGH THE FLORIDA PENINSULA DURING THE NEXT 6-12
HOURS. 24/12Z KTBW SOUNDING PROFILE WAS DRY...BUT NOT UNSEASONABLY
DRY...JUST YET. HOWEVER LOOKING UPSTREAM TOWARD BIRMINGHAM AND
ATLANTA WE BEGIN TO SEE A MUCH DRIER AIRMASS ABOVE THE SURFACE WHICH
WILL BE SETTLING SOUTHWARD AND OVER OUR HEADS FOR THE HOLIDAY
WEEKEND.
AT THE SURFACE...AS MENTIONED ABOVE...A LATE SEASON COLD FRONT IS
READY TO ADVANCE THROUGH THE FORECAST AREA TONIGHT. THE FRONT IS
CURRENTLY ANALYZED JUST SOUTH OF THE I-10 CORRIDOR WITH A DISTINCT
DEWPOINT DISCONTINUITY FROM MUCH OF THE FLORIDA PENINSULA UP TO THE
FL PANHANDLE AND SOUTHERN PORTION OF AL/GA. THIS MORE COMFORTABLE
AIRMASS IS ON ITS WAY TO US FOR THE WEEKEND. SEEING JUST A FEW
ISOLATED SHOWERS DOWN TOWARD FT. MYERS LATE THIS AFTERNOON. A FEW
MORE ARE POSSIBLE TO THE SOUTH OF I-4 DURING THE NEXT FEW
HOURS...HOWEVER ANY SHOWERS WILL BE SMALL AND BRIEF IN NATURE WITH
VERY LOW OVERALL COVERAGE.
&&
.SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)...
TONIGHT...
SURFACE FRONT SLIPS SOUTH OF THE REGION FOLLOWED QUICKLY
BY STRONG CONTINENTAL HIGH PRESSURE RIDGING DOWN FROM THE NORTH. A
FAVORABLE NNE DRAINAGE FLOW WILL ALLOW SOME OF OUR NORTHERN AREAS
AROUND LEVY/CITRUS COUNTIES TO DROP INTO THE MID/UPPER 50S TOWARD
SUNRISE ON SATURDAY...WHILE THE REMAINDER OF THE REGION DROPS DOWN
INTO THE 60S. ANY ISOLATED EVENING SHOWERS OVER THE FAR SOUTHERN
ZONES WILL END WITH THE FRONTAL PASSAGE SETTING UP A DRY AND
PLEASANT OVERNIGHT PERIOD.
SATURDAY THROUGH SUNDAY NIGHT...
MID/UPPER LEVEL TROUGH AXIS WILL PUSH EAST OF THE SOUTHEAST CONUS
WITH BROAD SYNOPTIC SUPPRESSION IN ITS WAKE FOR THE WEEKEND. A VERY
DRY MID-LEVEL AIRMASS WITH THETA-E VALUES WELL BELOW 320K WILL BE
ARRIVING FROM THE NORTH PROVIDING A QUITE HOSTILE ENVIRONMENT FOR
DEEP CONVECTION. WITH THIS IN MIND...NEAR ZERO RAIN CHANCES ARE IN
THE FORECAST FOR BOTH SATURDAY AND SUNDAY OVER OUR ZONES. MAY STILL
BE JUST ENOUGH MOISTURE AND LOW LEVEL FORCING TO SUPPORT AN ISOLATED
SHOWER OVER FAR SOUTH FLORIDA...BUT SEEMS APPARENT THAT ANY ACTIVITY
WILL BE SOUTH OF OUR ZONES. LOW LEVEL FLOW WILL BE STRONG ENOUGH OUT
OF THE EAST THIS WEEKEND THAT WE ARE UNLIKELY TO EVEN SEE MUCH (IF
ANY) SEA-BREEZE DEVELOPMENT...ESPECIALLY ON SATURDAY.
LOW LEVEL TEMPERATURES WILL COOL OFF SOMEWHAT BEHIND THE
FRONT...HOWEVER DRY CONDITIONS AND EXCELLENT DIURNAL MIXING WILL
COMPENSATE...AND STILL KEEP US ENJOYING SEASONABLE TEMPERATURES.
UPPER 80S TO NEAR 90 WILL BE COMMON THE NEXT COUPLE OF DAY...EVEN
CLOSE TO THE BEACHES AS THE EASTERLY FLOW HOLDS THE SEA-BREEZE TO
THE COAST OR EVEN JUST OFFSHORE.
THE IMPACT OF THE FRONT WILL BE FELT MORE AT NIGHT WITH BELOW NORMAL
LOW TEMPERATURES. MAY LOCATIONS AWAY FROM THE IMMEDIATE COAST WILL
LIKELY DIP INTO THE MID/UPPER 50S AROUND SUNRISE SUNDAY MORNING.
ALONG THE COAST FROM TAMPA BAY SOUTHWARD LOWER TO MIDDLE 60S WILL BE
MORE COMMON. SUNDAY NIGHT LOW TEMPERATURES WILL BE UP A FEW DEGREES
FROM THOSE ON SATURDAY NIGHT...BUT REMAIN BELOW NORMAL FOR LATE MAY.
&&
.LONG TERM (MONDAY THROUGH NEXT FRIDAY)...
MODEL SOLUTIONS REMAIN IN GOOD AGREEMENT SHOWING HIGH PRESSURE RIDGE
AXIS REMAINING NORTH OF THE FORECAST AREA THROUGH THE LONG TERM
PERIODS...KEEPING AN EASTERLY BOUNDARY LAYER FLOW IN PLACE. MOISTURE
WILL REMAIN LIMITED THROUGH MONDAY NIGHT...WITH RAIN FREE CONDITIONS
EXPECTED. BOUNDARY LAYER MOISTURE WILL THEN SLOWLY INCREASE THROUGH
THE REMAINDER OF THE WEEK...SO WILL CARRY SLIGHT CHANCE/LOW CHANCE
POPS IN MOST AREAS TUESDAY THROUGH FRIDAY FOR AFTERNOON/EARLY
EVENING SHOWERS AND THUNDERSTORMS.
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL WITH FEW-SCT CLOUDS THROUGH THE
AFTERNOON. THERE MAY BE SOME ISOLD TSRA NEAR PGD/FMY/RSW BUT NOT
CLOSE ENOUGH TO CARRY IN THE TAF. NORTHWEST AND GUSTY WINDS DIMINISH
SOME OVER NIGHT AS THEY SHIFT TO NORTH THEN NE...BECOMING ROBUST
AFTER SUNRISE.
&&
.MARINE...
ROUGH BOATING CONDITIONS ARE EXPECTED AT TIMES OVER THE EASTERN GULF
OF MEXICO THIS HOLIDAY WEEKEND. A COLD FRONT WILL CROSS THE FORECAST
WATERS THROUGH TONIGHT ALLOWING STRONG HIGH PRESSURE TO RIDGE DOWN
FROM THE NORTH IN ITS WAKE. WINDS WILL SHIFT NORTHEAST OVERNIGHT AND
INCREASE TO CAUTIONARY LEVELS INTO SATURDAY MORNING. A BRIEF
REDUCTION IN THE WINDS IS POSSIBLE SATURDAY AFTERNOON...BUT EXPECT
EASTERLY FLOW WILL QUICKLY INCREASE ONCE AGAIN TO ADVISORY LEVELS
SATURDAY EVENING AND REMAIN ELEVATED THROUGH SUNDAY MORNING. THE
RIDGE POSITION WILL SUPPORT OVERNIGHT AND MORNING EASTERLY WIND
SURGES THROUGH THE EARLY PORTION OF NEXT WEEK.
&&
.FIRE WEATHER..
A DRY AIRMASS WILL ARRIVE ACROSS THE REGION FOR THE UPCOMING HOLIDAY
WEEKEND. THIS DRY AIRMASS WILL ALLOW RELATIVE HUMIDITY VALUES TO
DROP BELOW 35 PERCENT OVER MUCH OF THE AREA SATURDAY AFTERNOON. THE
LOW RELATIVE HUMIDITY IS ANTICIPATED TO COMBINE WITH GUSTY EAST TO
NORTHEAST WINDS AND ENERGY RELEASE COMPONENT VALUES OF 27 OR HIGHER
TO PRODUCE CRITICAL FIRE WEATHER CONDITIONS FOR LOCATIONS CURRENTLY
WITHIN THE FIRE WEATHER WATCH. DRY CONDITIONS ARE ALSO ANTICIPATED
FOR SUNDAY WITH THE BEST CHANCES OF CRITICAL RELATIVE HUMIDITY
VALUES BEING ALONG AND NORTH OF THE I-4 CORRIDOR. WINDS ARE NOT
EXPECTED TO BE AS STRONG DURING SUNDAY AND ANY POTENTIAL RED FLAG
CONDITIONS LOOK TO BE DEPENDENT ON HOW ERC VALUES FLUCTUATE DURING
THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 71 90 65 88 / 10 0 0 0
FMY 69 92 66 87 / 20 10 0 0
GIF 68 89 61 87 / 10 0 0 0
SRQ 70 90 65 88 / 10 0 0 0
BKV 64 88 56 88 / 10 0 0 0
SPG 74 89 68 87 / 10 0 0 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH
SATURDAY EVENING FOR CITRUS-DESOTO-HARDEE-HERNANDO-
HILLSBOROUGH-MANATEE-PASCO-PINELLAS-POLK-SARASOTA-
SUMTER.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/FIRE WEATHER...MROCZKA
MARINE...MROCZKA/MCMICHAEL
AVIATION/DECISION SUPPORT...RUDE
LONG TERM...JELSEMA
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1151 AM MDT FRI MAY 24 2013
.UPDATE...
ISSUED AT 819 AM MDT FRI MAY 24 2013
MADE A FEW CHANGES TO THE FORECAST FOR TODAY. THE FIRST BEING
TO INCREASE THE WINDS FOR TODAY...ESPECIALLY DURING THE MORNING.
WINDS HAVE BEEN VARYING QUITE A BIT OVER THE PAST COUPLE OF HOURS.
HAVE BEEN CONTEMPLATING A WIND ADVISORY FOR THE WESTERN 2/3S OF
THE AREA. BIGGEST UNCERTAINTY IS WILL THE SUSTAINED WINDS REMAIN
AT 30 MPH OR CONTINUE TO VARY. IN ADDITION THE WINDS MAY
STRENGTHEN DURING THE AFTERNOON BEHIND THE WARM FRONT. AT THIS
POINT WILL ONLY INCREASE THE SUSTAINED WINDS TO JUST UNDER 30 MPH
FOR THE REST OF THE DAY FOR THE MAJORITY OF THE AREA...WHICH IS
JUST UNDER WIND ADVISORY CRITERIA. IF CRITERIA IS REACHED AM
CONFIDENT IT WILL BE VERY LOW END.
ALSO REMOVED THE MENTION OF FOG FOR ALL BUT EAST CENTRAL COLORADO
THIS MORNING. WEB CAMS AT FIRST VIEW AND GENOA BOTH SHOW
VISIBILITIES OF LESS THAN A MILE. DUE TO THE RATHER SMALL AREA
BEING AFFECTED AND SINCE THE FOG WILL BEGIN TO LIFT IN THE NEXT
HOUR OR SO...WILL NOT BE ISSUING ANY FOG RELATED HAZARDS.
DID DROP THE CHANCES FOR PRECIP. DOWN SOME THIS MORNING OVER THE
EAST. MODELS DO SHOW A MINOR UPPER LEVEL SHORT WAVE TROUGH MOVING
THROUGH...HOWEVER SOUNDINGS DO NOT LOOK VERY FAVORABLE FOR STORM
DEVELOPMENT THIS MORNING. WILL LEAVE A SLIGHT CHANCE IN...BUT THIS
MAY BE TOO MUCH FOR THE MORNING.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 434 AM MDT FRI MAY 24 2013
FORECAST PROBLEMS WILL BE NUMEROUS THROUGH THE WEEKEND. SATELLITE
SHOWING A FASTER/MORE PROGRESSIVE FLOW OVER THE PACIFIC WHICH THEN
TRANSITIONS TO A SLOWER AND MORE AMPLIFIED FLOW OVER NORTH AMERICA.
THE RIDGE OVER THE CENTRAL PORTION OF THE COUNTRY HAS INCREASED IN
AMPLITUDE OVER THE LAST 24 HOURS. UPPER LOW OVER THE PACIFIC
NORTHWEST HAS MOVED LITTLE IN THE LAST 24 HOURS. FRONT THAT MOVED
THROUGH YESTERDAY REMAINS DRAPED WELL SOUTH AND WEST OF THE AREA AT
THIS TIME.
THE SREF...NAM AND CANADIAN INITIALIZED BEST ON THE JET LEVEL WINDS
OVER OUR AREA. MODELS HAVING A LITTLE TROUBLE WITH THE DETAILS AT
MID LEVELS. OVERALL THE SREF AND NAM WERE DOING SLIGHTLY BETTER THAN
THE GFS...CANADIAN AND CANADIAN. THE NAM LOOKED LIKE IT WAS CATCHING
THE MINOR SHORTWAVE TROUGH TO OUR SOUTHWEST THE BEST. THE GFS WAS
DOING SLIGHTLY BETTER THAN THE ECMWF ON THE LOW LEVEL THERMAL FIELD.
THE GFS WAS TOO AGGRESSIVE WITH THE LOW LEVEL MOISTURE RETURN WITH
THE NAM DOING A LITTLE BETTER. MODELS DO NOT QUITE HAVE THE BOUNDARY
TO OUR SOUTH QUITE FAR ENOUGH SOUTH. THE NAM WAS DOING A LITTLE
BETTER HERE. ALSO MODELS HAD QPF TOO FAR NORTH BY 06Z WITH THE GFS...
CANADIAN AND THE SREF THE WORST OFFENDERS. AGAIN THE NAM WAS DOING
BETTER HERE.
TODAY/TONIGHT...MOST OF THE MODEL OUTPUT SHOWS A WEAK LEFT FRONT
QUADRANT OVER THE AREA BEGINNING NEAR 12Z AND MAINLY AFFECTING THE
SOUTHEAST HALF. A SMALL CLUSTER OF THUNDERSTORMS HAD DEVELOPED OVER
NORTHEAST NEW MEXICO AND THE PANHANDLE AREA. THIS LOOKS TO BE IN
RESPONSE TO SHORTWAVE TROUGH AND THE WEAK LEFT FRONT QUADRANT OF THE
JET. HOWEVER THAT DISSIPATED WITH ISOLATED THUNDERSTORMS DEVELOPING
OVER/NEAR THE EASTERN PORTION OF THE AREA.
THE NAM FOR THE MOST PART HAS THIS AREA DEPICTED WELL...ESPECIALLY
FOR THE JET. SO GOING BY THAT...WILL HAVE A SLIGHT CHANCE TO CHANCE
OF THUNDERSTORMS THROUGH MAINLY THE MORNING WITH IT POSSIBLY
LINGERING INTO EARLY AFTERNOON IN THE FAR EAST. STRATUS IS MOSTLY
OCCURRING OVER THE AREA AT THIS TIME WITH THE FOG CONFINED TO EASTERN
COLORADO. THIS MAKES SENSE WITH THIS BEING THE MAIN AREA OF LOW LEVEL
TRANSPORT OF MOISTURE AT THIS TIME. THE HRRR AND NAM INDICATE THE
BEST CHANCE OF FOG OVER THE WESTERN HALF OF THE AREA. A FEW SPOTS
ALSO REPORTING DRIZZLE AND SOUNDINGS WOULD INDICATE THAT WILL
CONTINUE INTO THIS MORNING. SO WILL HAVE AREAS OF FOG WITH PATCHY
DRIZZLE IN THE WESTERN HALF AND PATCHY FOG FURTHER EAST.
SOUTHERLY WINDS INCREASE INTO THE WINDY CATEGORY. GRADIENT DEFINITELY
SUPPORTS NEAR ADVISORY CRITERIA IN THE WEST BUT THERE THE 3 HOUR
PRESSURE FALLS ARE NOT THAT HIGH. GLD VWP DEFINITELY WOULD
SUPPORT WINDY. WILL RAISE WINDS TO NEAR ADVISORY IN THE FAR WEST.
NOW FOR THE PRECIPITATION CHANCES DURING THE AFTERNOON AND NIGHT.
SUBSIDENCE/DRYING OCCURS OUT EAST RATHER QUICKLY AFTER FIRST
SHORTWAVE. INSTABILITY AXIS...BEST HEATING...MID/UPPER LEVEL LIFT
AND SURFACE CONVERGENCE DEVELOPS NEAR OR OVER THE WESTERN PORTION OF
THE AREA. SO WILL GRADUALLY RAMP UP POPS DURING THE AFTERNOON. BEST
LIFT AND MOISTURE LOOK TO RESIDE OVER THE NORTH DURING THE NIGHT
AND HAVE INCREASED POPS OVER THE NORTH WITH LOWER POPS FURTHER
SOUTH. THUNDERSTORMS LOOK TO BE DONE BY 12Z. LOW LEVEL MOISTURE
INCREASES OVER THE EASTERN HALF TO TWO THIRDS AFTER 06Z. AT THIS TIME
MODELS INDICATING MOSTLY STRATUS. WILL INSERT FOG WITH THE GREATEST
CHANCE IN THE FAR EAST.
NOT A GOOD FEEL ON THE MAXES WITH THEM BEING DETERMINED BY THE
EXTENT OF THE STRATUS AND HOW LONG IT TAKES TO BURN OFF. IT IS
POSSIBLE THAT THICK CLOUD COVER WILL NOT BREAK UP UNTIL LATE
MORNING. SO TRENDED THE FORECAST COOLER.
SATURDAY/SATURDAY NIGHT...FOG WILL CLEAR OUT DURING THE MORNING.
MODELS NOT AGREEING WHERE DRY LINE ENDS UP...WHERE THE INSTABILITY
AXIS ENDS UP...WHERE THE CAP IS THE LEAST...AND SHORTWAVE DETAILS.
AT THIS TIME IT LOOKS LIKE THE DRY LINE ENDS UP NEAR OR A LITTLE
WEST OF THE COLORADO BORDER. ONE SHORTWAVE TROUGH EXITS THE EASTERN
PORTION OF THE AREA EARLY IN THE AFTERNOON WITH ANOTHER ONE
APPROACHING LATE IN THE AFTERNOON WITH THE BRUNT OF ITS LIFT COMING
THROUGH DURING THE NIGHT. MODELS ARE GENERATING QPF WHERE THERE IS
A STRONG CAP.
AS IT LOOKS NOW THE MAIN TIME FOR PRECIPITATION WILL WAIT TO BEGIN
UNTIL MID TO LATE EVENING. THE BEST CHANCE FOR THUNDERSTORMS WILL
BE EAST OF THE COLORADO BORDER...AND ESPECIALLY IN THE FAR EAST.
LOW LEVEL THERMAL FIELD IS MUCH WARMER THAN TODAYS. HOWEVER...IF
STRATUS/FOG LAST LONGER OR THE LEE TROUGH IS STRONGER/FURTHER WEST...
THE WINDS WILL BE MORE FROM AN EASTERLY DIRECTION AND NOT ALLOW FOR
AS BIG A WARM UP. KEPT THE WESTERN AREAS WARMER WITH COOLER MAXES
FURTHER EAST.
IN REGARDS TO FIRE...THE LOWEST RHS LOOK TO BE IN COLORADO AT THIS
TIME. HOWEVER...THAT IS WHERE THE LIGHTEST WIND FIELD IS. DUE TO A
LOT OF UNCERTAINTY...WAS NOT CONFIDENT ENOUGH TO THROW OUT A WATCH.
WILL HIGHLIGHT IN THE FIRE WEATHER FORECAST AND HWO.
SUNDAY/SUNDAY NIGHT...A LOT MORE DISAGREEMENT IN DETAILS SHOW UP IN
THIS PERIOD. CURRENT MODEL OUTPUT SUPPORTED THE GOING PRECIPITATION
FORECAST FOR THIS PERIOD AND LEFT IT ALONE. ALSO ONLY MADE SLIGHT
ADJUSTMENTS TO THE TEMPERATURE FORECAST AS WELL. P
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 235 AM MDT FRI MAY 24 2013
MEDIUM RANGE MODEL DIFFERENCES EMERGE EARLY IN THE EXTENDED
PERIOD...PARTICULARLY WITH REGARD TO AMPLITUDE OF UPPER FLOW
PATTERN. THE ECMWF IS MORE AMPLIFIED ON MONDAY WITH BOTH THE UPPER
RIDGE POSITIONED TO OUR EAST AND ALSO THE WESTERN CONUS UPPER
TROUGH. THE POSITION OF THESE FEATURES WILL PLACE OUR AREA IN
SOUTHWESTERLY FLOW ALOFT WITH THE LIKELIHOOD OF WEAK EMBEDDED
DIFFICULT TO TIME SHORTWAVES THAT COULD POTENTIALLY ENHANCE
PRECIPITATION DEVELOPMENT. BY TUESDAY THE PATTERN AMPLIFIES
FURTHER AND ECMWF CLOSES OFF AN UPPER LOW OVER THE SOUTHWEST
CONUS. GFS MAINTAINS AN OPEN WAVE AND SHIFTS IT EASTWARD WITH
NOTICEABLE HEIGHT FALLS OVER OUR AREA BY LATE TUESDAY AND
ESPECIALLY WEDNESDAY. THE NEW 00Z ECMWF HAS TRENDED THE DIRECTION
OF THE MORE PROGRESSIVE GFS AND OPENS UP THE SOUTHWEST CONUS UPPER
LOW RATHER THAN KEEP IT CLOSED AND SLOWLY MOVING IT EAST AS THE
12Z ECMWF INDICATED. STILL THE ECMWF IS CONSIDERABLY SLOWER THAN
THE GFS WITH THE EASTWARD PROGRESSION OF THIS TROUGH. THIS LEADS
TO A LOW CONFIDENCE FORECAST NEXT WEEK. GFS WOULD FAVOR A
POTENTIALLY WIDESPREAD PRECIPITATION / ORGANIZED CONVECTIVE EVENT
WEDNESDAY WHILE THE ECMWF SOLUTION WOULD SUPPORT A SIMILAR
SITUATION BY LATE WEDNESDAY / WEDNESDAY NIGHT INTO THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1142 AM MDT FRI MAY 24 2013
MVFR TO VFR CONDITIONS ARE FORECAST FOR THE 18Z TAFS. VISIBLE
SATELLITE IMAGERY SHOWS LOW CLOUDS DEPARTING THE AREA. EXPECT KMCK
TO BE OUT OF THE LOW CLOUDS SHORTLY AFTER TAF ISSUANCE. AS THE
CLOUDS CLEAR WINDS HAVE NOT STRENGTHENED MUCH AT ALL SO FAR...SO
AM EXPECTING THIS TO CONTINUE. HOWEVER WINDS WILL REMAIN BREEZY
THROUGH THE EVENING BEFORE SLOWING DURING THE OVERNIGHT HOURS.
LATER THIS AFTERNOON/EARLY EVENING THUNDERSTORMS WILL DEVELOP OVER
EASTERN COLORADO AND DEVELOP/PROGRESS EASTWARD. THE BEST CHANCE
FOR STORMS NEAR KGLD WILL BE AROUND 0Z...WITH STORMS DISSIPATING
AFTER A FEW HOURS. STRONG TO SEVERE WIND GUSTS WILL BE POSSIBLE
THROUGH THE EARLY EVENING WITH ANY STORMS THAT DEVELOP. FOR KMCK THE BEST
CHANCE WILL BE AROUND 6Z WITH STORMS MOVING EAST OF THE SITE BY
10Z. THERE MIGHT BE SOME FOG DEVELOPMENT AT KMCK LATE TONIGHT.
HOWEVER CURRENT DATA SUGGESTS ONLY A REDUCTION TO MVFR AT
BEST...SO WILL HOLD OFF PLACING A MENTION OF FOG IN FOR KMCK FOR
THIS TAF ISSUANCE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...BULLER
LONG TERM...BRB
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS GRAY ME
530 PM EDT FRI MAY 24 2013
.SYNOPSIS...
A COLD FRONT WILL PUSH OFFSHORE AND STALL THIS EVENING. LOW
PRESSURE WILL DEVELOP ON THE FRONT NEAR CAPE COD AND WILL SLOWLY
DRIFT NORTH THROUGH THE GULF OF MAINE SATURDAY AND SATURDAY NIGHT.
LOW PRESSURE WILL ACCELERATE NORTH INTO LABRADOR ON SUNDAY. HIGH
PRESSURE WILL BUILD IN FROM THE WEST SUNDAY NIGHT THROUGH MONDAY.
HIGH PRESSURE WILL SHIFT OFFSHORE ON TUESDAY. A WARM FRONT WILL
APPROACH FROM THE SOUTHWEST TUESDAY NIGHT AND WEDNESDAY AND WILL
PUSH EAST OF THE REGION WEDNESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
UPDATE...
HAVE UPDATED GRIDS BASED ON CURRENT CONDITIONS...WITH THE COLD
FRONT SLIPPING THROUGH THE COASTLINE AS OF 21Z. LOW PRESSURE WILL
CONTINUE TO TAKE SHAPE OFF THE NEW ENG COASTLINE THEREAFTER...WITH
CYCLOGENESIS OCCURRING NEAR CAPE COD THIS EVENING.
LATEST HRRR MODEL PICKING UP WELL ON CONVECTIVE SEGMENTS CROSSING
THE FORECAST AREA AT THIS TIME. THIS MODEL DEPICTS MORE AREAS OF
RAIN MOVING THROUGH THE REGION LATE TONIGHT AFTER A BREAK IN THE
ACTION LATER THIS EVENING.
WILL CONTINUE TO MONITOR COLD AIR RUSHING INTO THE MTNS FROM
CANADA OVERNIGHT. THERE COULD BE SOME MIXED SNOW AND RAIN OVER THE
HIGHER TERRAIN FOR THIS STORM WHICH IS VERY SIMILAR TO THE MAY
26TH 1967 EVENT.
HAVE ADJUSTED WINDS AND TEMPS FOR THE HIGHER TERRAIN. WINDS WILL
BECOME RATHER GUSTY FOR ANY HIKERS OUT OF THE NORTH AND NORTH OVER
THE NEXT COUPLE OF DAYS...WITH SOME SNOW ACROSS THE HIGH TERRAIN.
PREV DISC...
COLD FRONT CURRENTLY MOVING EAST THROUGH EASTERN NEW HAMPSHIRE
AND NORTHWEST MAINE AND THIS BOUNDARY WILL CONTINUE TO PUSH OFF TO
THE EAST THROUGH THE REMAINDER OF THE AFTERNOON. FRONT WILL STALL
OFFSHORE THIS EVENING AND WILL BE THE FOCUS OF LIGHT TO MODERATE
RAINFALL IN MID COAST AND CENTRAL MAINE DURING THE REMAINDER OF
THE AFTERNOON INTO THIS EVENING. WILL SEE A BRIEF BREAK IN THE
ACTION ACROSS NEW HAMPSHIRE DURING THE REST OF THE AFTERNOON
BEFORE NEXT BATCH OF PRECIP EDGES IN FROM THE WEST. WILL TAKE SOME
TIME FOR LOW PRESSURE TO GET SPUN UP OVERNIGHT SO THIS BREAK MAY
TRANSLATE EASTWARD INTO WESTERN MAINE FOR THE EVENING HOURS BEFORE
850 OVER-RUNNING GETS GOING IN EARNEST ACROSS WESTERN MAINE AFTER
MIDNIGHT.
12Z MODELS TRENDING FARTHER WEST WITH AXIS OF HEAVIEST PRECIP AND
COMING INTO LINE WITH LAST NIGHT 00Z ECMWF. 24 HOUR QPF FOR THE
MOUNTAINS AND CONNECTICUT VALLEY DOWN TO AROUND AN INCH TO 1.5
INCHES THROUGH 00Z SUN. WITH THIS IN MIND...DOESN`T APPEAR
FLOODING WILL BE AN ISSUE CONSIDERING THE BREAK IN THE ACTION
THIS AFTERNOON AND LONG DURATION OF THE EVENT ITSELF...SO HOLDING
OFF ON ANY WATCHES AT THIS POINT IN TIME.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
RAIN WILL CONTINUE SATURDAY THROUGH SATURDAY NIGHT AS SURFACE LOW
BECOMES TRAPPED UNDER UPPER LEVEL SYSTEM AND MEANDERS AROUND THE
GULF OF MAINE THROUGH SUNDAY MORNING. MAY SEE SOME WET SNOW OVER
THE HIGHEST TERRAIN AT SOME POINT ON SATURDAY IN FAR WESTERN ZONES BUT
ENOUGH WARM AIR WRAPS AROUND THE SYSTEM THAT THIS WOULD BE FAIRLY
BRIEF. BETTER CHANCE FOR THIS WOULD BE IN THE GREENS OF VERMONT
AND THE DACKS. WILL BE A COLD AND BLUSTERY DAY WITH TEMPS HOLDING
IN THE 40S IN MOST AREAS AND SHOWING LITTLE CHANGE SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
UPR LVL AND SFC LOWS LIFTING NE ON SUNDAY WITH STEADIER PRCP
BECOMING MORE SCT IN NATURE AND LIGHTER IN INTENSITY. ANY LEFTOVER
SHRA ENDING SUNDAY NGT AS THE SYSTEM MOVES INTO THE MARITIMES.
MEMORIAL DAY LOOKS LIKE FAIR WX NOW WITH SYSTEM PULLING OUT FAR
ENOUGH TO THE NE. STILL SOME CYCLONIC FLOW ALOFT AND SOME LEFTOVER
MOISTURE THAT COULD PRODUCE SOME CLOUDINESS ESPECIALLY IN THE N/MT
ZONES DUE TO UPSLOPING NW SFC WINDS. MIGHT SEE AN ISOLD SHRA IN
THE N/MT ZONES OTRW NO PRCP EXPECTED ON MEMORIAL DAY.
HIGH PRES AND UPR LVL RIDGE BUILD IN FOR TUESDAY INTO WEDNESDAY.
THE UPR LVL RIDGE HOLDS 0N OVER THE ERN U.S. BUT A SERIES OF WEAK
UPR LVL SHORT WAVE TROFS DRIVE THRU THE RIDGE FOR LATE WEDNESDAY
AND THURSDAY. THIS FORMS A WRM FRONTAL BOUNDARY TO OUR S THAT
LIFTS N AND WILL PROVIDE SOME CLOUDINESS AND ISOLD TO SCT SHRA
FROM LATE WEDNESDAY THRU THURSDAY. THE UPR LVL RIDGE BECOMES
BETTER ESTABLISHED OVER THE E COAST THURSDAY NGT AND FRIDAY AS THE
SHORT WAVES EXIT THE COAST. THIS SHOULD ALLOW WRM AIR TO CONT
MOVING IN FROM THE SW. STILL CAN`T RULE OUT PSBL SHRA DUE TO WRM
FNT MOVING THRU.
GENERALLY USED BLEND OF GFS40/NAM/MET/MAV/HPC QPF FOR PERIODS 4
AND 5 THEN GFS40, GMOS, HPC QPF, MEX MOS AND WNA4 FOR THE REST OF
THE LONG TERM FCST.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
SHORT TERM...IFR/LIFR CEILINGS TONIGHT THROUGH SATURDAY NIGHT.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...MVFR TO PSBL IFR IN SHRA
THAT WILL BE TAPERING OFF SUNDAY INTO SUNDAY NGT. MAINLY VFR
MONDAY THRU TUESDAY AND MOST OF WEDNESDAY.
&&
.MARINE...
SHORT TERM...HAVE EXTENDED SCA TO GO RIGHT THROUGH SATURDAY.
ALTHOUGH WINDS DROP OFF AT SOME POINT...WAVES WILL REMAIN AT LEAST
IN THE 3 TO 5 FOOT RANGE...WITH GREATER SEAS OUT OVER THE OPEN WATERS.
COASTAL FLOOD ADVISORY FOR MINOR SPLASH-OVER AROUND THE TIME OF
HIGH TIDE.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...SCA WIND GUSTS AND SEAS
PSBL SUNDAY THRU MOST OF SUNDAY NGT THEN HIGH PRES DROPS
CONDITIONS BELOW SCA LEVELS MONDAY THRU WEDNESDAY.
&&
.FIRE WEATHER...
NO PROBLEMS NOTED.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...COASTAL FLOOD ADVISORY FROM 10 PM THIS EVENING TO MIDNIGHT EDT
TONIGHT FOR MEZ023>028.
NH...COASTAL FLOOD ADVISORY FROM 10 PM THIS EVENING TO MIDNIGHT EDT
TONIGHT FOR NHZ014.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT SATURDAY FOR ANZ150>154.
&&
$$
CANNON
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
628 PM EDT FRI MAY 24 2013
.SYNOPSIS...
DRY AND COOL WEATHER CAN BE EXPECTED FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH SATURDAY/...
ADJUSTMENTS TO WINDS OVERNIGHT...JUST WEAKENED THEM A BIT FASTER.
TRIED TO TIME THE DECAYING OF CLOUD DECK...WITH LOW CONFIDENCE.
WESTERN EDGE OF CLOUDS ARE ERODING QUICKLY...BUT WITH CYCLONIC
FLOW AND COLD AIR ALOFT...TIMING IS DIFFICULT.
PREVIOUS DISCUSSION...
THE UPPER LEVEL TROUGH WILL CONTINUE TO PIVOT ACROSS THE REGION
THROUGH THE AFTERNOON AND EVENING AS HIGH PRESSURE TRIES TO BUILD
OVERHEAD AT THE SURFACE. COLD NORTHWEST FLOW CONTINUES TO KEEP
CLOUD COVER OVER MUCH OF THE FORECAST AREA THROUGH THIS
AFTERNOON...WHICH IS RIGHT IN LINE WITH THE LATEST RUC FORECAST.
WITH CLOUD COVER STILL IN PLACE...CONTINUED A DOWNWARD TREND IN
THE HIGH TEMPERATURES FOR THE AFTERNOON...WITH PIT LIKELY TO BE
VERY CLOSE TO BREAKING IT`S LOW HIGH TEMPERATURES RECORD FROM
1877.
THE MOST RECENT MODEL RUNS CONTINUE TO SUGGEST THAT CLOUDS WILL
EVENTUALLY DIMINISH OVER THE ENTIRE REGION...LASTING LONGEST IN
THE RIDGES. HOW FAST THE CLOUDS DIMINISH WILL PLAY A BIG ROLE IN
HOW QUICKLY TEMPERATURES DROP OVERNIGHT. HOWEVER...SINCE
TEMPERATURES ARE ALREADY LOWER THAN ORIGINALLY FORECAST...CLEARING
SKIES SHOULD ALLOW LOWS IN THE LOW TO MID 30`S TO BE REALIZED
RELATIVELY QUICKLY. FOR NOW...CONTINUED THE FROST/FREEZE AS
IS...ALTHOUGH SOME COUNTIES MAY NEED TO BE UPGRADED TO A FREEZE IF
SKIES CLEAR SOONER AND WINDS DECOUPLE.
HIGH PRESSURE WILL BUILD OVERHEAD SATURDAY BRINGING A CLEAR DAY
BUT NORTHWEST FLOW WILL KEEP TEMPERATURES 10 TO 15 BELOW SEASONAL
AVERAGES.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
HIGH PRESSURE WILL CONTINUE TO DOMINATE THROUGH THE SHORT TERM
PERIOD. TEMPERATURES WERE KEPT 5 DEGREES BELOW SEASONAL AVERAGES
SUNDAY...BUT MODERATED CLOSER TO NORMAL BY MONDAY. AN APPROACHING
WARM FRONT COULD BRING THE CHANCE FOR A SHOWER IN THE SOUTHERN
PORTIONS OF THE FORECAST AREA LATE MONDAY BUT FOR NOW...LEFT LOW
END POPS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A WARM FRONT MOVING NORTH ACROSS THE DISTRICT TUESDAY WILL BRING
A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH WEDNESDAY. AS THE WARM
FRONT MOVES NORTH OF THE FORECAST AREA THURSDAY WARM AND MORE HUMID
CONDITIONS WILL RETURN WITH HIGH TEMPERATURES INTO THE 80S THROUGH
FRIDAY. THERE WILL BE A SLIGHT CHANCE OF DIURNAL THUNDERSTORMS
THURSDAY AND FRIDAY.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
GENERAL MVFR TO VFR STRATOCU REMAINS IN PLACE THIS EVENING WITH
KFKL STILL BELOW 2000 FT AT THIS HOUR. GENERAL BROKEN VFR TO MVFR
CEILINGS CAN BE EXPECTED THIS EVENING. CEILINGS COULD SLOWLY LOWER
AFTER SUNSET AS GUSTY WINDS DIMINISH. NORTHERLY FLOW OFF THE LAKES
WILL TEND TO KEEPS SOME CLOUDINESS ACROSS THE DISTRICT INTO SATURDAY
MORNING.
.OUTLOOK.../SATURDAY THROUGH TUESDAY/...
HIGH PRESSURE WILL MAINTAIN GENERAL VFR THROUGH MONDAY. A WARM FRONT
WILL BRING A CHANCE OF SHOWERS AND THUNDERSTORMS FOR TUESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...FREEZE WARNING FROM 3 AM TO 8 AM EDT SATURDAY FOR MDZ001.
OH...FROST ADVISORY FROM 3 AM TO 8 AM EDT SATURDAY FOR OHZ039>041-
048>050-057>059-068-069.
PA...FROST ADVISORY FROM 3 AM TO 8 AM EDT SATURDAY FOR PAZ020-021-
029-031-073-075.
FREEZE WARNING FROM 3 AM TO 8 AM EDT SATURDAY FOR PAZ007>009-
013>016-022-023-074-076.
WV...FROST ADVISORY FROM 3 AM TO 8 AM EDT SATURDAY FOR WVZ001>004-
012-021-022.
FREEZE WARNING FROM 3 AM TO 8 AM EDT SATURDAY FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
326 PM EDT FRI MAY 24 2013
.SYNOPSIS...
DRY AND COOL WEATHER CAN BE EXPECTED FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH SATURDAY/...
THE UPPER LEVEL TROUGH WILL CONTINUE TO PIVOT ACROSS THE REGION
THROUGH THE AFTERNOON AND EVENING AS HIGH PRESSURE TRIES TO BUILD
OVERHEAD AT THE SURFACE. COLD NORTHWEST FLOW CONTINUES TO KEEP
CLOUD COVER OVER MUCH OF THE FORECAST AREA THROUGH THIS
AFTERNOON...WHICH IS RIGHT IN LINE WITH THE LATEST RUC FORECAST.
WITH CLOUD COVER STILL IN PLACE...CONTINUED A DOWNWARD TREND IN
THE HIGH TEMPERATURES FOR THE AFTERNOON...WITH PIT LIKELY TO BE
VERY CLOSE TO BREAKING IT`S LOW HIGH TEMPERATURES RECORD FROM
1877.
THE MOST RECENT MODEL RUNS CONTINUE TO SUGGEST THAT CLOUDS WILL
EVENTUALLY DIMINISH OVER THE ENTIRE REGION...LASTING LONGEST IN
THE RIDGES. HOW FAST THE CLOUDS DIMINISH WILL PLAY A BIG ROLE IN
HOW QUICKLY TEMPERATURES DROP OVERNIGHT. HOWEVER...SINCE
TEMPERATURES ARE ALREADY LOWER THAN ORIGINALLY FORECAST...CLEARING
SKIES SHOULD ALLOW LOWS IN THE LOW TO MID 30`S TO BE REALIZED
RELATIVELY QUICKLY. FOR NOW...CONTINUED THE FROST/FREEZE AS
IS...ALTHOUGH SOME COUNTIES MAY NEED TO BE UPGRADED TO A FREEZE IF
SKIES CLEAR SOONER AND WINDS DECOUPLE.
HIGH PRESSURE WILL BUILD OVERHEAD SATURDAY BRINGING A CLEAR DAY
BUT NORTHWEST FLOW WILL KEEP TEMPERATURES 10 TO 15 BELOW SEASONAL
AVERAGES.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
HIGH PRESSURE WILL CONTINUE TO DOMINATE THROUGH THE SHORT TERM
PERIOD. TEMPERATURES WERE KEPT 5 DEGREES BELOW SEASONAL AVERAGES
SUNDAY...BUT MODERATED CLOSER TO NORMAL BY MONDAY. AN APPROACHING
WARM FRONT COULD BRING THE CHANCE FOR A SHOWER IN THE SOUTHERN
PORTIONS OF THE FORECAST AREA LATE MONDAY BUT FOR NOW...LEFT LOW
END POPS.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
A WARM FRONT MOVING NORTH ACROSS THE DISTRICT TUESDAY WILL BRING
A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH WEDNESDAY. AS THE WARM
FRONT MOVES NORTH OF THE FORECAST AREA THURSDAY WARM AND MORE HUMID
CONDITIONS WILL RETURN WITH HIGH TEMPERATURES INTO THE 80S THROUGH
FRIDAY. THERE WILL BE A SLIGHT CHANCE OF DIURNAL THUNDERSTORMS
THURSDAY AND FRIDAY.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
GENERAL MVFR TO VFR STRATOCU REMAINS IN PLACE THIS EVENING WITH
KFKL STILL BELOW 2000 FT AT THIS HOUR. GENERAL BROKEN VFR TO MVFR
CEILINGS CAN BE EXPECTED THIS EVENING. CEILINGS COULD SLOWLY LOWER
AFTER SUNSET AS GUSTY WINDS DIMINISH. NORTHERLY FLOW OFF THE LAKES
WILL TEND TO KEEPS SOME CLOUDINESS ACROSS THE DISTRICT INTO SATURDAY
MORNING.
.OUTLOOK.../SATURDAY THROUGH TUESDAY/...
HIGH PRESSURE WILL MAINTAIN GENERAL VFR THROUGH MONDAY. A WARM FRONT
WILL BRING A CHANCE OF SHOWERS AND THUNDERSTORMS FOR TUESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...FREEZE WARNING FROM 3 AM TO 8 AM EDT SATURDAY FOR MDZ001.
OH...FROST ADVISORY FROM 3 AM TO 8 AM EDT SATURDAY FOR OHZ039>041-
048>050-057>059-068-069.
PA...FROST ADVISORY FROM 3 AM TO 8 AM EDT SATURDAY FOR PAZ020-021-
029-031-073-075.
FREEZE WARNING FROM 3 AM TO 8 AM EDT SATURDAY FOR PAZ007>009-
013>016-022-023-074-076.
WV...FROST ADVISORY FROM 3 AM TO 8 AM EDT SATURDAY FOR WVZ001>004-
012-021-022.
FREEZE WARNING FROM 3 AM TO 8 AM EDT SATURDAY FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1228 PM EDT FRI MAY 24 2013
.SYNOPSIS...
DRY AND COOL WEATHER CAN BE EXPECTED FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
LIGHT SHOWERS/DRIZZLE WILL CONTINUE TO DIMINISH THROUGH THE
AFTERNOON AS DRIER AIR WITH THE APPROACHING HIGH PRESSURE BEGINS
TO BUILD OVERHEAD. THE BIGGEST CONCERN FOR THE NEAR TERM IS THE
IMPACT CLOUD COVER WILL HAVE ON TEMPERATURES TODAY THROUGH THE
OVERNIGHT AND HOW THIS WILL FURTHER IMPACT FROST/FREEZE ACROSS THE
FORECAST AREA. THE MOST RECENT RUNS OF THE HRRR AND RUC SUGGEST THAT
MOISTURE TRAPPED UNDER THE LOW LEVEL INVERSION WILL STRUGGLE TO
MIX OUT TODAY...KEEPING CLOUD COVER OVER MUCH OF THE REGION LONGER
THAN ORIGINALLY ANTICIPATED. HAVE ALREADY LOWERED HIGH
TEMPERATURES A FEW DEGREES TODAY WITH THE CONTINUED COLD ADVECTION
AND CLOUD COVER. DEPENDING ON WHEN THE LOWER LEVELS DRY
OUT...TEMPERATURES MAY HAVE LITTLE TIME TO WARM BEFORE
NIGHTFALL...LEADING TO A MORE WIDESPREAD FREEZE. OR...AS THE RUC
SUGGESTS....CLOUDS COULD REMAIN OVER PORTIONS OF THE AREA THROUGH
MUCH OF THE NIGHT...ELIMINATING THE FROST/FREEZE POTENTIAL. AT
THIS POINT HOWEVER...FOLLOWED CLOSER TO NAM/GFS GUIDANCE AND
MAINTAINED CLEARING SKIES BY TONIGHT AND THUS HAVE MADE NO CHANGES
TO CURRENT PRODUCTS.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
DRY SFC HIGH PRES UNDR NW FLOW ALOFT WL MAINTAIN COLD TEMPS
THROUGH THE WEEKEND. EXPECT READINGS OF 10 TO 15 DEGREES UNDR THE
AVERAGES WITH FROST POTENTIAL AGAIN ON SATURDAY NGT.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
SFC HIGH PRES IS EXPECTED TO MAINTAIN DRY WEA UNTIL A WARM FRONT
INCREASES PCPN CHCS FOR WEDNESDAY AND THURSDAY. INITIALLY COLD TEMPS
WL MODERATE TO...AND THEN ABOVE SEASONAL LVLS AS SLY FLOW RESUMES
BY MID WEEK.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
GENERAL MVFR TO VFR STRATOCU REMAINS IN PLACE THIS AFTERNOON WITH
KMGW AND KFKL STILL BELOW 2000 FT AT THIS HOUR. CEILINGS WILL SLOWLY
LIFT DURING THE AFTERNOON...WITH GENERAL BROKEN VFR CEILINGS BY
THE LATE AFTERNOON HOURS. WINDS GUSTS OF 15 TO 20 KNOTS WILL PERSIST
THROUGH THE AFTERNOON...BUT SHOULD DIMINISH AFTER SUNSET. STRATOCU
CEILINGS MAY PERSIST AND LOWER INTO TONIGHT WITH NORTHERLY FLOW
OFF THE LAKES INTO SATURDAY MORNING.
.OUTLOOK.../SATURDAY THROUGH TUESDAY/...
HIGH PRESSURE WL MAINTAIN VFR THROUGH EARLY NXT WEEK.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...FREEZE WARNING FROM 3 AM TO 8 AM EDT SATURDAY FOR MDZ001.
OH...FROST ADVISORY FROM 3 AM TO 8 AM EDT SATURDAY FOR OHZ039>041-
048>050-057>059-068-069.
PA...FROST ADVISORY FROM 3 AM TO 8 AM EDT SATURDAY FOR PAZ020-021-
029-031-073-075.
FREEZE WARNING FROM 3 AM TO 8 AM EDT SATURDAY FOR PAZ007>009-
013>016-022-023-074-076.
WV...FROST ADVISORY FROM 3 AM TO 8 AM EDT SATURDAY FOR WVZ001>004-
012-021-022.
FREEZE WARNING FROM 3 AM TO 8 AM EDT SATURDAY FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1230 PM EDT FRI MAY 24 2013
.AVIATION...
//DISCUSSION...
12Z DTX SOUNDING SHOWED A REAL STRONG INVERSION AROUND 4000
FEET...WHICH ALLOWED COLD NORTHERLY FLOW OFF LAKE HURON TO SUPPORT
SOLID STRATUS DECK...WHICH IS CURRENTLY IN THE PROCESS OF MIXING
OUT. ONCE THIS OCCURS (MID AFTERNOON)...CLEAR SKIES SHOULD BE
THE RULE INTO TONIGHT. LOW LEVELS SHOULD BE WARM ENOUGH AND FLOW
BACKED TO THE WNW NOT TO SUPPORT A REPEAT PERFORMANCE OF THE LOW
CLOUDS TONIGHT. THERE WILL BE SOME MID/HIGH CLOUDS ARRIVING OVERNIGHT
HOWEVER...WITH JUST A BIT OF DIURNAL CU DEVELOPING TOMORROW (5000
FEET). MARGINALLY GUSTY NORTHWEST WINDS (AROUND 20 KNOTS) EARLY THIS
AFTERNOON DIMINISHING...WITH LIGHT AND VARIABLE WINDS TONIGHT INTO
TOMORROW.
//DTW THRESHOLD THREATS...
* LOW CONFIDENCE IN CEILINGS BELOW 5000 FEET 18-20Z.
&&
.PREV DISCUSSION...ISSUED 340 AM EDT FRI MAY 24 2013
SHORT TERM...TODAY AND TONIGHT
THE WEATHER UP FOR DISCUSSION IS THE PROSPECTS FOR OVERCAST SKIES
TODAY AS AN OPAQUE BLANKET OF 030-035 FT STRATUS IS AGGRESSIVELY
DIVING SOUTHWARD ACROSS LAKE HURON. TRAJECTORY OF CLOUD DECK IN
ADDITION TO THE ORIENTATION OF THE WESTERN EDGE ALIGNS WELL WITH THE
AXIS OF MAXIMUM 925-850MB COLD AIR ADVECTION AND THE DEPRESSION OF
THE LONGWAVE TROUGH AXIS. NWP DATA IS VIRTUALLY VOID OF CLOUD...A
RESULT OF INADEQUATE VERTICAL RESOLUTION WITHIN THE MODELS. WHILE
THE CLOUD IS COMPLETELY OPAQUE IT IS UNDOUBTEDLY A SHALLOW LAYER OF
MOISTURE THAT IS LIKELY TRAPPED WITHIN THE BASE OF THE INVERSION
AT/AROUND 900-890MB. RUC SOUNDINGS SHOW SATURATION AT THIS
ZONE...BUT THE SOUNDING STRUCTURE ITSELF DOES NOT INSPIRE MUCH
CONFIDENCE AS IT IS THE WRONG PROFILE. GIVEN THE TRUE NORTHERLY
TRAJECTORY...HAVE DECIDED TO INTRODUCE OVERCAST CONDITIONS FOR MUCH
OF THE CWA THROUGH THE MORNING HOURS. IT WILL BE DIFFICULT TO
PINPOINT ANY WEST EDGE OF THE CLOUDS GIVEN DEGREE OF DRY AIR
IMMEDIATELY TO THE WEST. PATTERN RECOGNITION SUGGESTS ENTRAINMENT AT
THE EDGE SHOULD AID DIURNAL MIXING TO FORCE STRATUS TO GO BROKEN BY
LATE MORNING...EVENTUALLY CLEARING OUT FOR THE AFTERNOON.
LOWERED MAX TEMPERATURES FOR MANY AREAS DUE TO THE CLOUD AND STEADY
COLD AIR ADVECTION. EXPECT TEMPERATURES TO EVENTUALLY REACH 60-61
DEGREES ACROSS THE SOUTH AND SAGINAW VALLEY VERY LATE IN THE DAY.
OTHERWISE TEMPERATURES ARE GOING TO STRUGGLE TO REACH THE LOWER 50S
IN THE THUMB.
FOR TONIGHT...THE COMPACT VORT OVER NORTHERN MANITOBA WILL GET
SQUEEZED WITH A ROGUE VORTICITY STREAMER OFF OF THE PACNW ANOMALY
MERGING OVER THE WESTERN GREAT LAKES. THIS WILL OCCUR DOWN THE FRONT
EDGE OF THE CENTRAL CONUS RIDGE...ALLOWING FOR A VERY HEALTHY
AGEOSTROPHIC RESPONSE AND STRIPE OF FRONTOGENESIS VERY LATE. ANY
SIGNIFICANT TEMPERATURE GRADIENT WILL RESIDE WELL WEST OF LOWER
MICHIGAN WHICH IS WHERE THE PRECIPITATION RESPONSE WILL OCCUR.
REGARDLESS...INCREASING CLOUDS LATE WILL ESTABLISH A FLOOR ON
MINIMUM TEMPERATURES TONIGHT.
LONG TERM...SATURDAY THROUGH THURSDAY
THE OVERALL PATTERN ACROSS NORTH AMERICA THIS WEEKEND WILL FEATURE A
QUASI OMEGA BLOCK. SHORT WAVE ENERGY NOW SHOWN ROTATING INTO NRN
MANITOBA IS FORECAST TO TRACK ACROSS THE ERN GREAT LAKES AND MID
ATLANTIC EARLY SATURDAY...LEADING TO DEEPENING OF AN UPPER LOW
ROTATING ACROSS NEW ENGLAND. LOWER MI WILL BE LOCATED BETWEEN THIS
SYSTEM AND AMPLIFYING MID LEVEL RIDGING ACROSS THE NRN PLAINS/UPPER
MS VALLEY. THIS WILL PLACE THE FORECAST AREA WITHIN A STRONGLY
CONFLUENT UPPER FLOW WITH PERSISTENT HIGH PRESSURE AT THE SURFACE.
THE RESIDENT AIRMASS ACROSS THE GREAT LAKES WILL BE COOL AND VERY
DRY. TEMPS ON SATURDAY SHOULD ONLY RISE TO THE LOW 60S OVER MUCH OF
THE FORECAST AREA WITH 850MB TEMPS HOVERING AROUND +2C. THE AIRMASS
WILL MODERATE DURING THE COURSE OF THE WEEKEND...WITH HIGHS EXPECTED
TO BE AROUND 70 BY MEMORIAL DAY. GIVEN THE DRY AIRMASS AND LIGHT
WINDS...NIGHTTIME LOWS WILL BE QUITE CHILLY THIS WEEKEND /30S AND
40S/.
A SEASONALLY STRONG 140+ KNOT UPPER JET IS FORECAST DIVE INTO THE
PACIFIC NORTHWEST EARLY NEXT WEEK...LEADING TO LONG WAVE TROUGH
AMPLIFICATION ACROSS THE WRN US AND A BUILDING SUBTROPICAL RIDGE
ACROSS THE SERN US. THIS WILL ALLOW THE MID LEVEL RIDGE TO BECOME
MORE PROGRESSIVE AND PASS EAST OF LOWER MI TOWARD MIDWEEK...ALLOWING
A SFC WARM FRONT TO LIFT ACROSS THE REGION FROM THE SOUTHWEST. THIS
WARM FRONT WILL ADVECT A WARM...MOIST AND UNSTABLE AIRMASS INTO THE
FORECAST AREA. THE GFS CONTINUES TO BRING THIS WARM FRONT THROUGH
FASTER THAN THE OTHER MODEL SOLUTIONS /SUGGESTING CONVECTION AS
EARLY AS MON NIGHT/. THE GFS HAS SOME OBVIOUS CONVECTIVE FEEDBACK
ISSUES DUE TO POTENTIAL MCS DEVELOPMENT OVER THE PLAINS. THE GFS IS
ALSO LESS AMPLIFIED WITH THE LONG WAVE TROUGH OVER THE WRN US. GIVEN
THE STRENGTH OF THE POLAR JET AND POTENTIAL PHASING WITH THE
SUBTROPICAL JET...THE MORE AMPLIFIED ECMWF REMAINS THE PREFERRED
SOLUTION. THIS SUGGESTS THE BETTER CHANCES FOR CONVECTION WILL HOLD
OFF UNTIL THE TUES NIGHT/WED TIME FRAME. DESPITE THIS UNCERTAINTY...
THE OVERALL TREND NEXT WEEK WILL BE FOR WARMER AND MORE HUMID
CONDITIONS WITH INCREASING CHANCES FOR THUNDERSTORMS.
MARINE...
UNSEASONABLE CONDITIONS ARE IN PLACE OVER THE CENTRAL GREAT LAKES
TODAY AS COLD AIR ADVECTION IS ONGOING WITHIN A DEEP TROUGH AXIS.
EFFICIENT NORTHERLY FLOW AND A LONG FETCH OVER THE WATERS WILL
SUSTAIN HIGH WAVE ACTIVITY FROM SAGINAW BAY DOWN TO PORT HURON.
RECENT WATER TEMPERATURE READINGS FROM THE BUOYS SUGGESTS THAT
CONDITIONS WILL BE SOLIDLY IN THE NEUTRAL REGIME OUT OVER THE OPEN
LAKE WHICH IS ATYPICAL FOR LATE MAY. IN FACT...CONDITIONS ARE
UNSTABLE FOR SAGINAW BAY WITH WATER TEMPERATURE READINGS SUGGESTING
LSTS ARE AT AROUND 13 TO 14 C VS AN 850MB TEMPERATURE THAT WILL BE
DIPPING DOWN TO -4C BY 12Z THIS MORNING. WILL EXPAND THE ADVISORY TO
INCLUDE INNER SAGINAW. CONDITIONS ARE MORE MARGINAL ON LAKE ST CLAIR
AND LAKE ERIE. WILL GIVE RESPECT TO PEAK OF THE COLD AIR ADVECTION
THAT WILL OCCUR THIS MORNING FOR THE SOUTHERN ZONES AND EXTEND THE
SMALL CRAFT FOR THEM AS WELL. THE STABLE SURFACE ANTICYCLONE WILL
BUILD INTO THE CENTRAL GREAT LAKES TONIGHT BRINGING A RETURN OF MUCH
MORE FAMILIAR STABLE SEASON MARINE WEATHER.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...
SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM PORT AUSTIN TO PORT
HURON...UNTIL 8 PM FRIDAY.
SMALL CRAFT ADVISORY...OUTER SAGINAW BAY...UNTIL 6 PM FRIDAY.
LAKE ST CLAIR...
SMALL CRAFT ADVISORY...UNTIL 4 PM FRIDAY.
MI WATERS OF LAKE ERIE...
SMALL CRAFT ADVISORY...UNTIL 4 PM FRIDAY.
&&
$$
AVIATION.....SF
SHORT TERM...CB
LONG TERM....SC
MARINE.......CB
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
629 PM EDT FRI MAY 24 2013
.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE CENTERED OVER THE WESTERN GREAT LAKES
WILL MOVE LITTLE THROUGH THE WEEKEND...THEN SLIDE TO THE EAST COAST
MONDAY AND TUESDAY. A WARM FRONT WILL DEVELOP OVER THE MISSISSIPPI
VALLEY BY MONDAY AND LIFT NORTH ACROSS THE AREA ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
MADE MINOR ADJUSTMENTS TO THE HOURLY TEMPERATURES AND SKY COVER THIS
EVENING FOR THE EARLY EVENING UPDATE. CALLED IT "CLEARING" FOR THE
NE OH/NW PA COUNTIES...OTHERWISE NO CHANGES TO THE CURRENT FORECAST.
EARLIER DISCUSSION...
GIVEN THE TIME OF YEAR AND IMPACT AND HAVE GONE WITH FROST AND
FREEZE HEADLINES FOR THE ENTIRE AREA. IT APPEARS THAT CLEARING
WILL RAPIDLY OCCUR THIS EVENING. WINDS SHOULD ALSO LESSEN. IF
SPEEDS STAY MORE THAN 5 OR 6 MPH OVERNIGHT FREEZING TEMPS WILL BE
HARD TO ACHIEVE. IF FREEZING TEMPS DO OCCUR IT WILL BE ONE OF THE
LATEST FREEZES EVER AT ALL OF THE CLIMATE SITES. TEMPS REMAIN IN
THE 40S MOST AREAS AND SHOULD DROP QUICKLY AFTER SUNSET. SOME
INDICATION THAT HIGH CLOUDS COULD SPILL INTO WESTERN AREAS LATE
TONIGHT. GIVEN THE STRENGTH OF THE HIGH THIS COULD BE A LITTLE
OVERDONE SO HAVE TAKEN THE FROST HEADLINE ALL THE WAY TO KTOL AND
KFDY. LATEST HRRR HAS SURFACE TEMPS TO 34 DEGREES BY 04Z OVER MOST
OF INLAND NE OH AND NW PA. IF THAT OCCURS FROST IS LIKELY BY EARLY
MORNING.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY NIGHT/...
DRY HIGH PRESSURE WILL DOMINATE THROUGH THE HOLIDAY WEEKEND. THE
AREA WILL REMAIN COOL WITH ONLY VERY SLOWLY MODERATING TEMPERATURES.
WILL LIKELY NEED MORE FROST HEADLINES SATURDAY NIGHT IN THE EAST.
EXPECT TEMPS TO STRUGGLE TO GET ABOVE 60 ON SATURDAY AND OUT OF
THE LOWER AND MIDDLE 60S ON SUNDAY. TEMPERATURE MAY GET TO 70 ON
MONDAY BUT THAT WILL STILL BELOW NORMAL. MODELS HAVE BEEN SHOWING
A SYSTEM MOVING OUT OF THE PLAINS MONDAY. A WARM FRONT FROM THIS
SYSTEM WILL BEGIN TO IMPACT THE AREA MONDAY NIGHT AND HAVE PUT
SOME WARM AIR ADVECTION PRECIP IN THE WEST MONDAY NIGHT. THINK DRY
WEATHER WILL PREVAIL IN THE EAST TILL AFTER THE SHORT TERM PERIOD.
GIVEN A LOOK AT UPSTREAM SATELLITE TODAY SKIES SHOULD BE ALMOST
COMPLETELY CLEAR ON SATURDAY WITH JUST SOME HIGH CLOUDS THE
REMAINDER OF THE WEEKEND. HAVE TRENDED TO COOL SIDE OF GUIDANCE
THROUGH THE PERIOD.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
THE BEST CHANCE FOR SHOWERS AND THUNDERSTORMS WILL BE TUESDAY AND
TUESDAY NIGHT AS A WARM FRONT LIFTS THROUGH. IN THE WARM AIR MASS
WEDNESDAY THROUGH FRIDAY THERE COULD BE SOME POP UP SHOWERS AND
THUNDERSTORMS...CONTINUING THE 20 POPS. OTHERWISE A WARMING TREND
WITH HIGHS ABOVE NORMAL. USED A BLEND OF GUIDANCE...ESPECIALLY HPC.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE IS BUILDING IN THROUGH TONIGHT. THE CLOUDS WILL
SLOWLY DECREASE AND THE CEILINGS ARE RISING AND WILL BE VFR BY MID
AFTERNOON. SKIES SHOULD BE CLEAR BY DARK. NOT EXPECTING MUCH FOG
AT THE TAF SITES BUT SOME MVFR FOG MAY OCCUR AT FAVORED LOCATIONS.
VFR SATURDAY WITH SOME CIRRUS AND A LIGHT NORTHWEST WIND.
.OUTLOOK...NON VFR POSSIBLE IN SHOWERS AND THUNDERSTORMS MONDAY
NIGHT THROUGH TUESDAY.
&&
.MARINE...
DROPPING THE SMALL CRAFT ADVISORY ON THE EXTREME WEST END OF THE
LAKE AS THE HIGH IS BUILDING IN. OTHERWISE NO CHANGES TO THE
HEADLINES. THE ONLY CONCERN IS THAT THE WAVES COULD BE NEAR SMALL
CRAFT ADVISORY CRITERIA SATURDAY AFTERNOON IN THE NORTHWEST
FLOW...THIS WILL HAVE TO BE MONITORED.
OTHERWISE NOT EXPECTING CONDITIONS TO MEET SMALL CRAFT ADVISORY
CONDITIONS ON THE LAKE IN A MAINLY SOUTHWEST FLOW.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...FROST ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EDT SATURDAY FOR
OHZ003-006>012-017>019-027-028-036-089.
FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM EDT SATURDAY FOR
OHZ013-014-020>023-029>033-037-038-047.
PA...FROST ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EDT SATURDAY FOR
PAZ001.
FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM EDT SATURDAY FOR
PAZ002-003.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT SATURDAY FOR LEZ146>149.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LEZ144-145.
&&
$$
SYNOPSIS...KOSARIK/KUBINA
NEAR TERM...KOSARIK/KUBINA
SHORT TERM...KUBINA
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
423 PM EDT FRI MAY 24 2013
.SYNOPSIS...
CHILLY HIGH PRESSURE TAKES CHARGE TONIGHT INTO SATURDAY. WARM
FRONT LIFT NORTH INTO THE OHIO VALLEY AND WEST VIRGINIA EARLY
TUESDAY. A WARMING TREND EXPECTED MEMORIAL DAY THROUGH NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
VERY TOUGH FCST TONIGHT REGARDING FROST/FREEZE POTENTIAL. DWPTS
CURRENTLY STRADDLING THE MARGINAL THRESHOLD FOR FROST TONIGHT
GIVEN AFTN MIXING. NOT SURE IF THESE GO LWR NEXT FEW HRS BEFORE
RECOVERING THIS EVE. GUIDANCE FOR METRO AREAS IN THE LOWLANDS RUN
32 TO 40F FROM KHTS TO KCRW. H925 WINDS STAY UP ARND 20 KTS
OVERNIGHT AS SFC HIGH BUILDS IN TO ALLOW WINDS AT THE GROUND TO
TRY TO GO CALM. ALL OF THIS COMPLICATES MATTERS FOR EXPANDING
FROST ADV. HOWEVER...GIVEN TIME OF YEAR AND FACT THAT MOST FOLKS
HAVE SOME OF THEIR VEGGIES IN THE GROUND ALONG WITH ANNUAL PLANT
INVESTMENTS...FELT PRUDENT TO LEAN A LITTLE LIBERAL AND EXPAND TO
ENCOMPASS REST OF CWA SAVE FOR S COAL FIELDS TO SW VA. OUTLYING
AREAS WILL SEE BEST SHOT OF FROST. HEADLINE SHOULD GARNER MORE
ATTENTION FOR FOLKS TO TAKE PRECAUTIONS TO BE ON SAFE SIDE. ALSO
EXPANDED FRZ WARNING TO RALEIGH BASED ON GUIDANCE RANGING FROM 28F
TO 33F. THEY WILL HAVE GET UNDER INVERSION THOUGH GIVEN H925 WINDS
OFF MDLS OVERNIGHT. OTHER CONCERN IS STRATUS OVERNIGHT ACROSS THE
N. NAM HAS BEEN WAY TOO FAST IN ERADICATING THE LLVL MOISTURE VS
RUC WHICH HAS BEEN PRETTY STEADY. RUC SHOWS CLDS LIFTING AND SCT
THIS EVE ACROSS THE N BEFORE REDEVELOPING IN N MTNS BY 06Z. NAM
KEEPS ENTIRE COLUMN DRY BUT HAS NOT HANDLED TDY WELL AT ALL. SO
WILL LEAN TOWARD RUC AND REDEVELOP SOME STRATUS IN N MTNS LATE
TONIGHT. THIS MAY KEEP TEMPS UP TONIGHT ESPECIALLY IN
VALLEYS...BUT STILL FEEL AOB FRZ TEMPS WILL BE REALIZED.
UPR TROF AXIS SHIFTS TO E COAST ON SAT WITH SOME RECOVERY IN TEMPS
COMPARED TO TDY. INHERITED TEMPS LOOKED GOOD AND ONLY NEEDED
TWEAKING SOME...MAINLY ACROSS THE N.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
MADE MODIFICATIONS TO THE SHORT TERM FORECAST AS FOLLOWS:
HIGH PRESSURE WILL BE IN CONTROL THROUGH THE WEEKEND...KEEPING DRY
CONDITIONS AREAWIDE. MODELS SHOW A MID LEVEL SHORTWAVE...EVIDENT
IN H5 CHARTS...UNDER NORTHWEST FLOW ALOFT...MOVING ACROSS SOUTHERN
OH...SOUTHEAST INTO NORTHWEST KY. REMOVED ANY POPS FOR THE WEEKEND
AS MOISTURE LOOKS VERY LIMITED OVER WV. IN FACT...THERE COULD BE
SOME CLEARING SATURDAY NIGHT INTO SUNDAY MORNING...KEEPING
TEMPERATURES AT OR JUST BELOW FREEZING OVER POCAHONTAS AND
RANDOLPH COUNTIES. INCLUDED PATCHY FROST OVER NORTHEAST MOUNTAINS.
HIGH PRESSURE MOVES EAST OVER THE MID ATLANTIC STATES KEEPING
INFLUENCE OVER WV FOR A DRY SUNDAY THROUGH MONDAY NIGHT.
MINOR CHANGES TO TEMPERATURES THROUGH THE PERIOD...PERHAPS A
COUPLE DEGREES LOWER CLOSER TO THE COOLER MET.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ANOTHER SHORTWAVE UNDER NORTHWEST FLOW ALOFT PASSES ACROSS
SOUTHEAST OH AND WV MONDAY AND TUESDAY. AT THE SAME TIME...A WARM
FRONT LIFTS NORTH INTO SOUTHERN OH...ACROSS WV AND VA ORIENTED
WEST TO EAST BY 12Z TUESDAY. THESE TWO FEATURES WILL BE CAPABLE TO
PRODUCE SHOWERS AND STORMS LATE MONDAY INTO TUESDAY AS THE WARM
FRONT MOVES NORTH OF THE AREA BY EARLY WEDNESDAY. INCREASED POPS
TO CHANCE INCLUDING THUNDER IN WEATHER GRIDS ACCORDINGLY.
HIGH PRESSURE TAKES CONTROL BY EARLY WEDNESDAY PROVIDING DRY
WEATHER WITH A SLOW WARMING TREND THROUGH THE REST OF THE WEEK.
TWEAKED COUPLE OF DEGREES DOWN FROM HPC GUIDANCE IN THE EXTENDED
PERIODS.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
STRATOCU SHOULD BEGIN TO DISSIPATE FROM W TO E BY THIS EVE.
EXCEPTION BEING N LOWLANDS AND ESPECIALLY N MTNS WHERE MVFR
STRATUS MAY REDEVELOP AFTER 06Z. HAVE KEKN WITH SOME BKN MVFR
BASES AS A RESULT. OTHERWISE SFC HIGH WILL BUILD IN AFTER 09Z WITH
SLACKENING WINDS THIS EVE WITH LOSS OF SUN. NW FLOW ALOFT TONIGHT
AND TOMORROW. MAY SEE SOME FG HUG WARMER RVRS WHICH MAY AFFECT RVR
TERMINALS. HAVE SOME MVFR VSBY ATTM WITH BL WINDS HANGING ONTO A
BIT OF A PUFF. VFR CONDITIONS RETURN FOR ALL TOMORROW WITH JUST
SOME PASSING MID CLDS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SATURDAY...
FORECAST CONFIDENCE...MEDIUM.
ALTERNATE SCENARIOS: EXTENT OF FG OVERNIGHT IN QUESTION. STRATUS
MAY NOT REDEVELOP ACROSS THE MTNS AS FCST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
EDT 1HRLY 16 17 18 19 20 21 22 23 00 01 02 03
CRW CONSISTENCY H H H H H H H H H H M M
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H M M
EKN CONSISTENCY M M M M M M M M M M M M
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H M M M M
AFTER 18Z SATURDAY...
IFR CONDITIONS POSSIBLE IN FOG EARLY SATURDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FROST ADVISORY FROM 2 AM TO 8 AM EDT SATURDAY FOR WVZ005>011-
013>020-026>032-039-040.
FREEZE WARNING FROM 2 AM TO 8 AM EDT SATURDAY FOR WVZ035>038-
046-047.
OH...FROST ADVISORY FROM 2 AM TO 8 AM EDT SATURDAY FOR OHZ066-067-
075-076-083>087.
KY...FROST ADVISORY FROM 2 AM TO 8 AM EDT SATURDAY FOR KYZ101>103-
105.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/30
NEAR TERM...30
SHORT TERM...ARJ
LONG TERM...ARJ
AVIATION...30
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
355 PM EDT FRI MAY 24 2013
.SYNOPSIS...
CHILLY HIGH PRESSURE TAKES CHARGE TONIGHT INTO SATURDAY. WARM
FRONT IN LOWER OHIO VALLEY GRADUALLY SHIFTS NE TOWARD MEMORIAL DAY
AND TUESDAY.
&&
.NEAR TERM /THROUGH SATURDAY NIGHT/...
VERY TOUGH FCST TONIGHT REGARDING FROST/FREEZE POTENTIAL. DWPTS
CURRENTLY STRADDLING THE MARGINAL THRESHOLD FOR FROST TONIGHT GIVEN
AFTN MIXING. NOT SURE IF THESE GO LWR NEXT FEW HRS BEFORE RECOVERING
THIS EVE. GUIDANCE FOR METRO AREAS IN THE LOWLANDS RUN 32 TO 40F
FROM KHTS TO KCRW. H925 WINDS STAY UP ARND 20 KTS OVERNIGHT AS SFC
HIGH BUILDS IN TO ALLOW WINDS AT THE GROUND TO TRY TO GO CALM. ALL
OF THIS COMPLICATES MATTERS FOR EXPANDING FROST ADV. HOWEVER...GIVEN
TIME OF YEAR AND FACT THAT MOST FOLKS HAVE SOME OF THEIR VEGGIES IN
THE GROUND ALONG WITH ANNUAL PLANT INVESTMENTS...FELT PRUDENT TO
LEAN A LITTLE LIBERAL AND EXPAND TO ENCOMPASS REST OF CWA SAVE FOR S
COAL FIELDS TO SW VA. OUTLYING AREAS WILL SEE BEST SHOT OF FROST.
HEADLINE SHOULD GARNER MORE ATTENTION FOR FOLKS TO TAKE PRECAUTIONS
TO BE ON SAFE SIDE. ALSO EXPANDED FRZ WARNING TO RALEIGH BASED ON
GUIDANCE RANGING FROM 28F TO 33F. THEY WILL HAVE GET UNDER INVERSION
THOUGH GIVEN H925 WINDS OFF MDLS OVERNIGHT. OTHER CONCERN IS STRATUS
OVERNIGHT ACROSS THE N. NAM HAS BEEN WAY TOO FAST IN ERADICATING THE
LLVL MOISTURE VS RUC WHICH HAS BEEN PRETTY STEADY. RUC SHOWS CLDS
LIFTING AND SCT THIS EVE ACROSS THE N BEFORE REDEVELOPING IN N MTNS
BY 06Z. NAM KEEPS ENTIRE COLUMN DRY BUT HAS NOT HANDLED TDY WELL AT
ALL. SO WILL LEAN TOWARD RUC AND REDEVELOP SOME STRATUS IN N MTNS
LATE TONIGHT. THIS MAY KEEP TEMPS UP TONIGHT ESPECIALLY IN
VALLEYS...BUT STILL FEEL AOB FRZ TEMPS WILL BE REALIZED.
UPR TROF AXIS SHIFTS TO E COAST ON SAT WITH SOME RECOVERY IN TEMPS
COMPARED TO TDY. INHERITED TEMPS LOOKED GOOD AND ONLY NEEDED
TWEAKING SOME...MAINLY ACROSS THE N.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
MOST NOTABLE CHANGES MADE TOWARD MEMORIAL DAY. TIMING THE EVENTUAL
NORTHEAST MOVEMENT AS A WARM FRONT...OF THE FRONTAL ZONE SETTING UP
OVER THE LOWER OHIO VALLEY INTO THE TENNESSEE VALLEY IS A
CHALLENGE.
ONE DISTURBANCE RIDES FROM NW TO SE OVERNIGHT SATURDAY NIGHT INTO
EARLY SUNDAY...BUT WILL KEEP ANY SPOTTY LIGHT RAIN TO OUR SW-S. DID
HAVE MORE CLOUDS OVER OUR SOUTHERN COUNTIES IN THE FORM OF SOME
PATCHY MID/HIGH CLOUDS. FURTHER NORTH...SATURDAY NIGHT WILL STILL
BE MOSTLY CLEAR AND CHILLY ESPECIALLY FOR NORTHERN AND CENTRAL WEST
VIRGINIA. DID INCLUDE SOME FROST IN OUR CENTRAL WV MOUNTAIN
COUNTIES FOR THE EARLY DAWN SUNDAY.
WILL INCREASE POPS ON MONDAY...THINKING THE WARM FRONT WILL BEGIN
LIFTING NORTHEAST...AT LEAST OVER THE MIDWEST...LEAVING US
VULNERABLE DOWNSTREAM. HOW ACTIVE THE WARM FRONT IS...IS ANOTHER
DILEMMA.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
HIGH PRESSURE REMAINS IN CONTROL TO AT LEAST EARLY WEDNESDAY
PROVIDING DRY WEATHER WITH A SLOW WARMING TREND.
ANOTHER MID LEVEL SHORTWAVE WILL MOVE THROUGH SUNDAY NIGHT FOR LOW
CHANCE FOR RAIN SHOWERS INTO MONDAY.
A WARM FRONT DEVELOPS AS IT APPROACHES THE REGION ON MONDAY. AS A
RESULT...THERE WILL BE A CHANCE OF SHOWERS AND STORMS MONDAY AND
TUESDAY...MAINLY DURING THE AFTERNOON AND EVENING HOURS.
FOR SATURDAY...TEMPERATURES SHOULD BE NEAR NORMAL WITH DAYTIME
HIGHS IN THE 70S ACROSS LOWLANDS...WITH 60S ACROSS THE HIGHER
ELEVATIONS. TEMPERATURES WILL CONTINUE TO CLIMB IN THE UPPER TO
MID 80S BY THE END OF THE WEEK. LOWS WILL RANGING IN THE 60S.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
STRATOCU SHOULD BEGIN TO DISSIPATE FROM W TO E BY THIS EVE.
EXCEPTIONG BEING N LOWLANDS AND ESPECIALLY N MTNS WHERE MVFR
STRATUS MAY REDEVELOP AFTER 06Z. HAVE KEKN WITH SOME BKN MVFR
BASES AS A RESULT. OTHERWISE SFC HIGH WILL BUILD IN AFTER 09Z WITH
SLACKENING WINDS THIS EVE WITH LOSS OF SUN. NW FLOW ALOFT TONIGHT
AND TOMORROW. MAY SEE SOME FG HUG WARMER RVRS WHICH MAY AFFECT RVR
TERMINALS. HAVE SOME MVFR VSBY ATTM WITH BL WINDS HANGING ONTO A
BIT OF A PUFF. VFR CONDITIONS RETURN FOR ALL TOMORROW WITH JUST
SOME PASSING MID CLDS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SATURDAY...
FORECAST CONFIDENCE...MEDIUM.
ALTERNATE SCENARIOS: EXTENT OF FG OVERNIGHT IN QUESTION. STRATUS
MAY NOT REDEVELOP ACROSS THE MTNS AS FCST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
EDT 1HRLY 16 17 18 19 20 21 22 23 00 01 02 03
CRW CONSISTENCY H H H H H H H H H H M M
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H M M
EKN CONSISTENCY M M M M M M M M M M M M
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H M M M M
AFTER 18Z SATURDAY...
IFR CONDITIONS POSSIBLE IN FOG EARLY SATURDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FROST ADVISORY FROM 2 AM TO 8 AM EDT SATURDAY FOR WVZ005>011-
013>020-026>032-039-040.
FREEZE WARNING FROM 2 AM TO 8 AM EDT SATURDAY FOR WVZ035>038-
046-047.
OH...FROST ADVISORY FROM 2 AM TO 8 AM EDT SATURDAY FOR OHZ066-067-
075-076-083>087.
KY...FROST ADVISORY FROM 2 AM TO 8 AM EDT SATURDAY FOR KYZ101>103-
105.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/30
NEAR TERM...30
SHORT TERM...KTB
LONG TERM...ARJ
AVIATION...30
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
321 PM EDT FRI MAY 24 2013
.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE CENTERED OVER THE GREAT LAKES WILL
MOVE LITTLE THROUGH THE WEEKEND. THE HIGH WILL MOVE OFF TO THE
NORTHEAST MONDAY AND TUESDAY. THIS WILL ALLOW A WARM FRONT TO LIFT
NORTH INTO THE REGION ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
GIVEN THE TIME OF YEAR AND IMPACT AND HAVE GONE WITH FROST AND
FREEZE HEADLINES FOR THE ENTIRE AREA. IT APPEARS THAT CLEARING
WILL RAPIDLY OCCUR THIS EVENING. WINDS SHOULD ALSO LESSEN. IF
SPEEDS STAY MORE THAN 5 OR 6 MPH OVERNIGHT FREEZING TEMPS WILL BE
HARD TO ACHIEVE. IF FREEZING TEMPS DO OCCUR IT WILL BE ONE OF THE
LATEST FREEZES EVER AT ALL OF THE CLIMATE SITES. TEMPS REMAIN IN
THE 40S MOST AREAS AND SHOULD DROP QUICKLY AFTER SUNSET. SOME
INDICATION THAT HIGH CLOUDS COULD SPILL INTO WESTERN AREAS LATE
TONIGHT. GIVEN THE STRENGTH OF THE HIGH THIS COULD BE A LITTLE
OVERDONE SO HAVE TAKEN THE FROST HEADLINE ALL THE WAY TO KTOL AND
KFDY. LATEST HRRR HAS SURFACE TEMPS TO 34 DEGREES BY 04Z OVER MOST
OF INLAND NE OH AND NW PA. IF THAT OCCURS FROST IS LIKELY BY EARLY
MORNING.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY NIGHT/...
DRY HIGH PRESSURE WILL DOMINATE THROUGH THE HOLIDAY WEEKEND. THE
AREA WILL REMAIN COOL WITH ONLY VERY SLOWLY MODERATING TEMPERATURES.
WILL LIKELY NEED MORE FROST HEADLINES SATURDAY NIGHT IN THE EAST.
EXPECT TEMPS TO STRUGGLE TO GET ABOVE 60 ON SATURDAY AND OUT OF
THE LOWER AND MIDDLE 60S ON SUNDAY. TEMPERATURE MAY GET TO 70 ON
MONDAY BUT THAT WILL STILL BELOW NORMAL. MODELS HAVE BEEN SHOWING
A SYSTEM MOVING OUT OF THE PLAINS MONDAY. A WARM FRONT FROM THIS
SYSTEM WILL BEGIN TO IMPACT THE AREA MONDAY NIGHT AND HAVE PUT
SOME WARM AIR ADVECTION PRECIP IN THE WEST MONDAY NIGHT. THINK DRY
WEATHER WILL PREVAIL IN THE EAST TILL AFTER THE SHORT TERM PERIOD.
GIVEN A LOOK AT UPSTREAM SATELLITE TODAY SKIES SHOULD BE ALMOST
COMPLETELY CLEAR ON SATURDAY WITH JUST SOME HIGH CLOUDS THE
REMAINDER OF THE WEEKEND. HAVE TRENDED TO COOL SIDE OF GUIDANCE
THROUGH THE PERIOD.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
THE BEST CHANCE FOR SHOWERS AND THUNDERSTORMS WILL BE TUESDAY AND
TUESDAY NIGHT AS A WARM FRONT LIFTS THROUGH. IN THE WARM AIRMASS
WEDNESDAY THROUGH FRIDAY THERE COULD BE SOME POP UP SHOWERS AND
THUNDERSTORMS...CONTINUING THE 20 POPS. OTHERWISE A WARMING TREND
WITH HIGHS ABOVE NORMAL. USED A BLEND OF GUIDANCE...ESPECIALLY HPC.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
HIGH PRESSURE IS BUILDING IN THROUGH TONIGHT. THE CLOUDS WILL
SLOWLY DECREASE AND THE CEILINGS ARE RISING AND WILL BE VFR BY MID
AFTERNOON. SKIES SHOULD BE CLEAR BY DARK. NOT EXPECTING MUCH FOG
AT THE TAF SITES BUT SOME MVFR FOG MAY OCCUR AT FAVORED LOCATIONS.
VFR SATURDAY WITH SOME CIRRUS AND A LIGHT NORTHWEST WIND.
.OUTLOOK...NON VFR POSSIBLE IN SHOWERS AND THUNDERSTORMS MONDAY
NIGHT THROUGH TUESDAY.
&&
.MARINE...
DROPPING THE SMALL CRAFT ADVISORY ON THE EXTREME WEST END OF THE
LAKE AS THE HIGH IS BUILDING IN. OTHERWISE NO CHANGES TO THE
HEADLINES. THE ONLY CONCERN IS THAT THE WAVES COULD BE NEAR SMALL
CRAFT ADVISORY CRITERIA SATURDAY AFTERNOON IN THE NORTHWEST
FLOW...THIS WILL HAVE TO BE MONITORED.
OTHERWISE NOT EXPECTING CONDITIONS TO MEET SMALL CRAFT ADVISORY
CONDITIONS ON THE LAKE IN A MAINLY SOUTHWEST FLOW.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...FROST ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EDT SATURDAY FOR
OHZ003-006>012-017>019-027-028-036-089.
FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM EDT SUNDAY FOR
OHZ013-014-020>023-029>033-037-038-047.
PA...FROST ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EDT SATURDAY FOR
PAZ001.
FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM EDT SUNDAY FOR
PAZ002-003.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT SATURDAY FOR LEZ146>149.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LEZ142>145.
&&
$$
SYNOPSIS...KUBINA
NEAR TERM...KUBINA
SHORT TERM...KUBINA
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
332 PM CDT FRI MAY 24 2013
.SHORT TERM (TONIGHT)...THIS MORNINGS SOUTHERN MCV ASSISTED IN
THE DEVELOPMENT OF A LINE OF SHOWERS AND THUNDERSTORMS ACROSS THE
WESTERN BRUSH COUNTRY LATE MORNING AND EARLY AFTERNOON. FOLLOWING
CLOSE TO THE HIGH RES 18Z HRRR FOR THE REST OF THIS AFTERNOON AND
EVENING...WHICH WAS THE ONLY MODEL THAT SEEMED TO HAVE A DECENT
HANDLE ON THE SITUATION. THE LINE WILL CONTINUE EAST INTO THE
INLAND COASTAL BEND OVER THE NEXT 2 HOURS...THEN POSSIBLY WEAKEN
AS OUTFLOW BOUNDARY PUSHES OUT AHEAD OF IT (MAY BE EVIDENCE OF
THIS OUTFLOW BOUNDARY ALREADY DEVELOPING. THE ENVIRONMENT ACROSS
THE EASTERN BRUSH COUNTRY AND COASTAL BEND IS UNSTABLE...WITH
MLCAPE 2000-2500 J/KG AND UNCAPPED. SHEAR IS RELATIVELY
WEAK...NEVERTHELESS A FEW STRONGER STORMS PRODUCING SMALL HAIL AND
WIND GUSTS UP TO 50 MPH ARE POSSIBLE OVER THE NEXT COUPLE OF
HOURS. CONVECTION SHOULD GRADUALLY END AROUND OR AFTER SUNSET.
&&
.LONG-TERM (SATURDAY THROUGH FRIDAY)...WEAK SHORTWAVES WILL CONTINUE
TO AFFECT SOUTH TEXAS ON SATURDAY AND INTO SUNDAY. MODELS ALL
INDICATE ENERGY WITH THESE SHORTWAVES...BUT ARE A BIT DIFFERENT IN
THE FINER DETAILS. STILL THINK THE NEXT WAVE TOMORROW COULD BRING A
SLIGHT CHANCE FOR THUNDERSTORMS TO THE AREA. HAVE SPREAD THE SLIGHT
CHANCE AREA FARTHER EAST GIVEN INCREASED MOISTURE FARTHER EAST THAN
PREVIOUS MODELS HAD INDICATED. HAVE A LINGERING 10 POP WITH SLIGHT
CHANCE WORDING FOR SUNDAY AS A SHORTWAVE WEAKER THAN THE OTHERS
PASSES BY...BUT GUIDANCE STILL INDICATING SOME QPF ACROSS THE AREA.
FOR MONDAY AND TUESDAY HIGH PRESSURE RIDGE BUILDS STRONGER ACROSS
THE AREA WHILE 850 THETA E RIDGE SHIFTS WESTWARD. THIS WILL DRY
THINGS OUT A BIT IN THE MID LEVELS AND ALLOW TEMPERATURES TO
INCREASE. INCREASED PRESSURE GRADIENT WITH RESULTING FROM THE
STRENGTHENING RIDGE TO THE EAST WILL ALSO INCREASE WINDS ACROSS THE
AREA EARLY IN THE WEEK. SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE
BY MID-WEEK.
AN UPPER LEVEL TROUGH WILL BE DIGGING INTO THE WESTERN US BY MID
WEEK AS WELL. MODEL SOLUTIONS HAVE NOT BEEN CONSISTENT WITH THE
AMPLITUDE OF THIS TROUGH. SOME MODELS INDICATE A PRETTY DEEP TROUGH
DIGGING AS FAR SOUTH AS NORTHERN MEXICO. OTHER MODELS SHOW A MUCH
WEAKER TROUGH. NOT CONFIDENT YET IN CHANCES FOR PRECIP
THURSDAY/FRIDAY...BUT WILL LEAVE 20 POPS FROM PREVIOUS FORECAST AT
THIS TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 76 89 75 90 75 / 30 10 10 10 10
VICTORIA 74 88 72 90 71 / 30 20 10 10 10
LAREDO 75 92 74 96 74 / 30 20 10 10 10
ALICE 75 89 73 92 73 / 30 20 10 10 10
ROCKPORT 75 87 75 88 76 / 30 10 10 10 10
COTULLA 74 91 72 95 72 / 30 30 10 10 10
KINGSVILLE 76 90 75 91 74 / 30 10 10 10 10
NAVY CORPUS 75 86 75 87 76 / 30 10 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
JR/76...SHORT TERM
PZ/83...LONG TERM
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
104 PM CDT FRI MAY 24 2013
.UPDATE...
18Z AVIATION DISCUSSION INCLUDED BELOW. SMALL UPDATE MOSTLY TO
BUMP UP HIGH TEMPS ACROSS THE BOARD TODAY GIVEN RECENT OBSERVED
TRENDS. POP-WISE...THE BEST CHANCES FOR AFTN TSTRMS ARE TENDING TO
FAVOR OUR EASTERN COUNTIES IN LIGHT OF A SLOWLY-RETREATING AREA OF
CUMULUS OBSERVED FROM QUANAH SOUTH TO HASKELL. RECENT HRRR RUNS
SEEM THE MOST CREDIBLE WITH INITIATION NEAR OUR EASTERN-MOST
COUNTIES BY EARLY-MID AFTN WITH REDUCED CHANCES FARTHER WEST.
RECENT LUBBOCK RADAR AND WTM STATIONS HAVE SHOWN A SUBTLE OUTFLOW
BOUNDARY LIFTING NORTHWEST BETWEEN TAHOKA AND GRAHAM...ALTHOUGH I
AM NOT OPTIMISTIC THIS FEATURE WILL IMPROVE CHANCES FOR PRECIP ON
THE CAPROCK AS WATER VAPOR SHOWS A NARROW ZONE OF SUBSIDENCE
SPREADING NORTH. REMAINDER OF THE FORECAST REMAINS IN CHECK.
&&
.AVIATION...
VFR CONDITIONS THIS AFTERNOON COULD BE THREATENED BY A FEW +TSRA
WITH THE BEST CHANCE OF THIS OCCURRING AT CDS...HOWEVER LOW
COVERAGE OF STORMS IMPLIES KEEPING PRECIP MENTION OUT FOR NOW.
CONFIDENCE IS HIGHER THAT LOW CIGS AND/OR SOME LIGHT FOG WILL
DEVELOP EARLY SAT MORNING AT THE TERMINALS...SO HAVE INSERTED A
PERIOD OF MVFR CONDITIONS AS MOIST SELY WINDS REMAIN INTACT.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 84 60 84 60 93 / 20 20 20 20 20
TULIA 83 62 83 60 92 / 20 20 20 20 10
PLAINVIEW 84 63 83 61 91 / 20 20 20 20 10
LEVELLAND 85 64 84 62 92 / 20 20 20 20 10
LUBBOCK 84 65 83 63 92 / 20 20 20 20 10
DENVER CITY 85 64 84 61 92 / 20 20 20 20 10
BROWNFIELD 85 65 84 62 92 / 20 20 20 20 10
CHILDRESS 83 66 85 66 93 / 30 20 20 20 10
SPUR 83 66 82 63 91 / 20 20 20 20 10
ASPERMONT 84 67 84 66 92 / 30 20 20 20 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
93/99/93
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
336 PM CDT FRI MAY 24 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 334 PM CDT FRI MAY 24 2013
AT 3 PM...A 1003 MB HIGH PRESSURE SYSTEM...CENTERED OVER LAKE
MICHIGAN...KEPT SKIES PARTLY SUNNY ACROSS THE UPPER MISSISSIPPI
RIVER VALLEY. MEANWHILE FURTHER WEST...A SHORT WAVE WAS PRODUCING
SHOWERS AND THUNDERSTORMS ACROSS THE EASTERN QUARTER OF THE
DAKOTAS AND WESTERN MINNESOTA. THE MESO AND DETERMINISTIC MODELS ARE
CONTINUING TO STRUGGLE WITH THE EASTWARD PROGRESS OF THIS
PRECIPITATION TONIGHT. THE ECMWF AND HRRR MOVE THIS PRECIPITATION
ACROSS MOST OF FORECAST AREA BY 25.06Z. MEANWHILE THE
NMM...ARW...GFS...GEM...RAP... AND NAM MAINLY CONFINE THE
PRECIPITATION WEST OF THE MISSISSIPPI RIVER THIS EVENING...AND
THEN MOVES IT ACROSS THE REMAINDER OF THE AREA OVERNIGHT. SINCE
THE CONVECTION ACROSS THE DAKOTAS WILL BE MOVING INTO AN AREA WITH
LESS FRONTOGENETIC FORCING...MOISTURE TRANSPORT...WEAK ISENTROPIC
LIFT...AND DRIER AIR...DECIDED TO TREND THE FORECAST TOWARD THE
LATTER MODEL SET. IN ADDITION...THE RADAR ECHOS ACROSS WESTERN
MINNESOTA ARE SHOWING A DECREASING TREND. EVEN BY DOING
THIS...THERE IS SOME VARIATIONS AMONGST THEM...SO TRIED TO GO WITH
AN ENSEMBLE APPROACH WHEN ASSIGNING THE HOURLY PRECIPITATION
CHANCES. THE HIGHEST PRECIPITATION CHANCE AND AMOUNTS /UP TO A
HALF INCH/ WILL BE FOUND ACROSS ACROSS SOUTHEAST MINNESOTA AND
NORTHEAST IOWA.
ON SATURDAY...THE SHORT WAVE WILL MOVE EAST SOUTHEAST ACROSS IOWA.
AS THIS OCCURS...THE 850 MB MOISTURE TRANSPORT AND ISENTROPIC LIFT
WILL GRADUALLY WEAKEN. AS A RESULT...WENT WITH A DECREASING TREND
IN THE PRECIPITATION TRENDS FROM LATE MORNING INTO THE AFTERNOON.
ADDITIONAL RAIFALL AMOUNTS WILL BE LESS THAN 2 TENTHS OF AN INCH.
WITH THE 24.12Z AND 24.18Z MODELS IN GOOD AGREEMENT THAT THERE
WILL BE LESS THAN 100 J/KG CAPES...JUST KEPT AN ISOLATED
THUNDERSTORM CHANCE MAINLY WEST AND SOUTH IF THE INTERSTATE 94
CORRIDOR.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 334 PM CDT FRI MAY 24 2013
FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT...THE WARM FRONT WILL
REMAIN WELL SOUTHWEST OF THE FORECAST AREA. AS A RESULT...
SOUTHEAST MINNESOTA...NORTHEAST IOWA...AND SOUTHWEST WISCONSIN
WILL REMAIN CLOUDY WITH PERIODIC SHOWERS AND MAYBE AN ISOLATED
THUNDERSTORM. OVER THE PAST 3 DAYS...THE CONSALL HAS CONTINUED
TO TREND TOWARD COOLER HIGH TEMPERATURES FOR SUNDAY. IT NOW HAS
HIGH TEMPERATURES AROUND 60. MEANWHILE THE ECMWF ONLY HAS HIGH
TEMPERATURES IN THE LOWER 50S FOR THESE AREAS. SINCE THE ECMWF
TYPICALLY VERIFIES THE BEST FOR THIS TIME PERIOD...WENT WITH A
BLEND OF THE CONSALL...CONSALLBC...AND EMCWF.
FROM MEMORIAL DAY INTO TUESDAY...THE MODELS ARE CONTINUING TO SHOW
THAT A WARM FRONT WILL MOVE NORTHWARD INTO THE AREA. THIS WILL
ALLOW ML CAPES TO CLIMB INTO THE 1K TO 3K J/KG RANGE. AS A
RESULT...EXPECT THE THUNDERSTORM CHANCES TO INCREASE DURING THIS
TIME PERIOD. THE 0-3KM SHEAR WOULD BE FAVORABLE FOR THE
POSSIBILITY THAT A FEW THUNDERSTORMS MAY BE CAPABLE OF PRODUCING
LARGE HAIL AND DAMAGING WINDS.
FROM TUESDAY NIGHT INTO FRIDAY...THE MODELS CONTINUE TO STRUGGLE
ON WHERE THE WARM SECTOR WILL BE LOCATED. THIS GREATLY AFFECTS
THE WHERE THE PRECIPITATION MAY BE LOCATED. IN ADDITION...IT WILL
ALSO AFFECT THE SHEAR AND INSTABILITY...THUS...THERE IS A LOT OF
UNCERTAINTY ON WHETHER THERE WILL BE ANY SEVERE WEATHER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1214 PM CDT FRI MAY 24 2013
FOCUS OF THE FORECAST IS ON THE POTENTIAL FOR SHOWERS LATE TONIGHT
INTO SATURDAY MORNING. SHORT WAVE TROUGH IN THE LEE OF THE ROCKIES
OVER WYOMING IS EXPECTED TO TOP THE MEAN RIDGE AND SLIDE ACROSS
THE REGION LATE TONIGHT AND SATURDAY MORNING. AN AXIS OF MOISTURE
TRANSPORT IS EXPECTED TO DEVELOP THIS AFTERNOON AHEAD OF THIS WAVE
THEN BEND TO THE NORTHEAST AND BE FOCUSED INTO THE AREA LATE
TONIGHT. HOWEVER...THIS WILL BE WEAKENING THROUGH THE NIGHT AND
WILL NOT BE VERY STRONG BY THE TIME IT BECOMES FOCUSED ON THE
LOCAL AREA. THE FORCING FROM THE WAVE AND THE WEAK MOISTURE
TRANSPORT SHOULD BE ENOUGH TO GENERATE SOME SHOWERS. EXPECT THESE
WILL MOVE INTO BOTH TAF SITES BETWEEN 09Z AND 12Z. THE SHOWERS
SHOULD BE LIGHT ENOUGH TO NOT PRODUCE ANY VISIBILITY RESTRICTION
BUT COULD PRODUCE SOME MVFR CEILINGS AS THE RAIN SATURATES THE LOW
LEVELS OF THE COLUMN ENOUGH TO ALLOW THE CEILINGS TO LOWER. THE
24.09Z SREF SHOWS THE BETTER PROBABILITIES OF THIS OCCURRING ARE
WEST OF THE MISSISSIPPI RIVER SO HAVE INCLUDED THIS AT KRST. THE
ISENTROPIC UPGLIDE ON THE 300K SURFACE BEGINS TO WEAKEN AFTER 15Z
SATURDAY BUT DOES CONTINUE FOR THE REMAINDER OF THE MORNING AND
SHOULD BE ENOUGH TO KEEP SOME SHOWERS OR SPRINKLES GOING THROUGH
THE END OF THE FORECAST PERIOD.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...04
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND SATURDAY
ISSUED AT 248 PM CDT FRI MAY 24 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH
PRESSURE STRETCHING FROM HUDSON BAY TO LAKE MICHIGAN TO THE
CENTRAL GULF COAST. A FEW STRANDS OF CIRRUS IS INVADING NW
WISCONSIN EARLY THIS AFTERNOON...BUT OTHERWISE...CLEAR AND COOL
CONDITIONS ARE PREVAILING. LOOKING UPSTREAM...STRENGTHENING RETURN
FLOW OVER THE PLAINS IS CREATING A BAND OF SHOWERS AND
THUNDERSTORMS OVER EASTERN NORTH AND SOUTH DAKOTA. AS THIS WARM
FRONT SHIFTS EAST TONIGHT...PRECIP CHANCES ARE THE MAIN FORECAST
CONCERN.
TONIGHT...A JET STREAK...BETWEEN A SE DIVING SHORTWAVE OVER THE
EASTERN GREAT LAKES AND A MID-LEVEL RIDGE OVER THE GREAT
PLAINS...WILL SLIDE SOUTHEAST ACROSS THE REGION. RIGHT REAR QUAD OF
THIS JET STREAK WILL SHIFT OVER NORTH-CENTRAL AND NORTHEAST
WISCONSIN AFTER MIDNIGHT. DESPITE VERY DRY AIR IN THE LOW
LEVELS...MODELS SPIT OUT A COUPLE BANDS OF PRECIP AS A RESULT OF
MID-LEVEL CONVERGENCE/FGEN AND UPPER DIVERGENCE...THOUGH DIFFER IN
THEIR PLACEMENT. THE LARGEST BAND WILL BE TIED TO THE PRIMARY
BAROCLINIC ZONE OFF TO OUR WEST AND SOUTHWEST...WHICH THE NAM/GFS
HAVE TRENDED A BIT TO THE WEST. HOWEVER...THE 12Z MESOMODELS
CONTINUE TO PUSH THIS BAND OF PRECIP OVER CENTRAL WISCONSIN BETWEEN
06Z AND 12Z. DO NOT HAVE A GOOD FEEL WHERE THIS BAND WILL END UP.
BUT LIGHT LOW LEVEL SE WINDS WILL SUPPLY A STEADY DIET OF DRY
AIR...SO PRECIP WILL HAVE TO FALL OUT OF A MID-DECK...AND GIVEN THE
WEAK FORCING...CANNOT SEE MUCH MORE THAN SPRINKLES LIKE THE PREVIOUS
FORECASTER MENTIONED. GIVEN THE LOW IMPACT AND TO MATCH UP WITH
OFFICES TO THE WEST AND NORTH...WILL KEEP THE MENTION OF SPRINKLES
OVER CENTRAL WISCONSIN. A LOWERING CLOUD DECK WILL KEEP TEMPS WARMER THAN
LAST NIGHT AND WILL GO WITH MID 30S NORTH TO MID 40S SOUTH. PATCHY
FROST WILL REMAIN POSSIBLE OVER FAR NORTHERN WISCONSIN.
SATURDAY...RIGHT REAR QUAD WILL SLIDE TO THE SOUTH-CENTRAL GREAT
LAKES DURING THE MORNING. ANY SPRINKLE ACTIVITY SHOULD BE ENDING
EARLY SO IT DOES NOT SEEM WORTH MENTIONING IN THE FORECAST. THE
DEPARTING MID-LEVEL CONVERGENCE SHOULD ALLOW DRY AIR TO RETURN TO
NORTHEAST WISCONSIN LATE MORNING ONWARD WHEN SHOULD SEE DECREASING
CLOUDS. CLOUDS TO HANG LONGER OVER CENTRAL AND NORTH-CENTRAL
WISCONSIN...CLOSER TO THE PRIMARY BAROCLINIC ZONE. WITH THE
ADDITIONAL CLOUD COVER...TEMPS TO REMAIN NEAR OR SLIGHTLY COOLER
THAN TODAYS READINGS...AND WILL RANGE FROM THE UPPER 50S OVER
CENTRAL WISCONSIN TO THE MIDDLE 60S OVER NORTHEAST WISCONSIN.
.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY
ISSUED AT 248 PM CDT FRI MAY 24 2013
GOOD AGREEMENT BETWEEN GUIDANCE IN BIG PICTURE WITH STRENGTHENING
RIDGE IN THE EAST WHILE TROF PERSISTS OVER THE WEST. PLEASANT
WEATHER IS EXPECTED THROUGH MUCH OF THIS MEMORIAL DAY WEEKEND.
AT THE SURFACE DRY HIGH PRESSURE TO THE EAST WILL MAINTAIN EAST TO
SOUTHEAST FLOW OVER THE REGION. SOME MODEL DISCONNECT WITH HOW
HANDLE SHORT WAVE ACTIVITY EXITING WESTERN TROF INTO THE PLAINS
AND WESTERN LAKES LATE THIS HOLIDAY PERIOD. HAVE STAYED TOWARD
DRIER EC/GFS...WITH IDEA THAT HIGH WILL KEEP PCPN TO OUR SOUTHWEST
SUN AND MON. NAM APPEARS THE OUTLIER...TOO STRONG AND FAST. LIGHT
WINDS AND DRY CONDITIONS TO LEAD TO ANOTHER COOL NIGHT FOR
NORTHEAST WI...WITH PATCHY FROST OVER PARTS OF FAR NORTHEAST WI.
TROF DEEPENS WEST BEGINNING OF NEXT WEEK PUMPING UP RIDGE JUST TO
OUR EAST. THIS TO LEAD TO WARMER TEMPS AND INCREASING HUMIDITY AND
INSTABILITY AS WARM FRONT LIFTS NORTH TOWARDS...OR THROUGH STATE.
AGAIN SOME DISPARITY ON HOW FAR NORTH FRONT WILL GO...WITH EC
LINGERING IT OVER NORTHERN WI. COULD BE LOOKING A PERIOD OF ACTIVE
WEATHER NEXT WED/THU WITH POSSIBILITY OF PERIODS OF HEAVY RAINFALL
AS PW`S INCREASE TO 1.5.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 101 PM CDT FRI MAY 24 2013
VFR CONDITIONS EXPECTED FOR THE NEXT FEW DAYS. EVEN ANY SPRINKLES
THAT DEVELOP LATE TNGT/EARLY SAT SHOULD BE FALLING OUT OF A MIDDLE
CLD DECK WITH HIGH BASES. &&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......TE
AVIATION.......MPC