Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/31/13
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
940 AM PDT WED MAY 29 2013
...BECOMING MUCH HOTTER AND DRIER BY FRIDAY AND SATURDAY...
.DISCUSSION...AS OF 9:40 AM PDT WEDNESDAY...A RIDGE OF HIGH PRESSURE
IS BUILDING OVER THE EASTERN PACIFIC THIS MORNING. MOISTURE IS
FLOWING OVER THE RIDGE INTO THE FORECAST AREA...THIS IS RESULTING
IN A MIX OF LOW AND MID CLOUDS. THESE CLOUDS SHOULD BEGIN TO
SCATTER OUT BY LATE MORNING RESULTING IN MOSTLY SUNNY TO PARTLY
CLOUDY SKIES.
THE MAIN WEATHER CONCERN FOR THE NEXT SEVERAL DAYS WILL BE THE
POTENTIAL FOR EXCESSIVELY WARM WEATHER THIS WEEKEND. THE
PREVIOUSLY MENTIONED RIDGE OF HIGH PRESSURE IS EXPECTED TO BUILD
AS THE AIRMASS WARMS OVER THE FORECAST AREA. 500MB HEIGHTS ARE
EXPECTED TO REACH 585 DM BY FRIDAY OVER THE SAN FRANCISCO BAY
AREA. AT THE SURFACE A THERMAL TROUGH FORMS OVER THE FORECAST AREA
FRIDAY SLIDING WEST BY SATURDAY...RESULTING IN OFFSHORE FLOW.
850 MB TEMPERATURES ARE EXPECTED TO CLIMB TO 22 DEGREES C SATURDAY
NEAR SAN JOSE WITH 24 DEGREES C EXPECTED IN THE SOUTHERN SALINAS
VALLEY. THE COMBINATION OF THE WARM AIRMASS AND OFFSHORE FLOW WILL
RESULT IN VERY WARM AFTERNOON TEMPERATURES SATURDAY. TEMPERATURES
ALONG THE COAST WILL BE IN THE MID 70S TO NEAR 80S WITH LOCAL
SPOTS SUCH AS SANTA CRUZ REACHING INTO THE UPPER 80S. IN LAND
TEMPERATURES WILL RANGE FROM THE MID 80S TO MID 90S WITH SOME
LOCATIONS IN THE SOUTHERN SALINAS VALLEY REACHING 100 DEGREES.
THE WARM AIRMASS WILL ALSO PROMOTE WARM OVERNIGHT TEMPERATURES...ESPECIALLY
IN THE MOUNTAINS. OVERNIGHT LOW TEMPERATURES WILL ONLY FALL INTO
THE MID 70S OVERNIGHT IN THE MOUNTAINS WHICH WILL ALSO PROMOTE
POOR RELATIVE HUMIDITY RECOVERIES. THE POOR RELATIVE HUMIDITY
RECOVERIES WILL RAISE FIRE CONCERNS...DRYING FUELS WITH OFFSHORE
WINDS.
THE NEXT HURTLE WILL BE DETERMINING HOW LONG THE WARM TEMPERATURES
WILL LAST...ESPECIALLY ALONG THE COAST. THE 1200Z RUN OF THE GFS
40 INDICATES THAT A SOUTHERLY SURGE WILL BE POSSIBLE SUNDAY WHICH
WOULD MOST LIKELY RESULT IN SUBSTANTIAL COOLING ALONG THE COAST.
HOWEVER...850 MB TEMPERATURES REMAIN NEAR 25 DEGREES C INLAND
SUNDAY WHICH WOULD CONTINUE TO SUPPORT HOT INLAND TEMPERATURES.
&&
.AVIATION...AS OF 4:40 AM PDT WEDNESDAY...POSSIBLE MVFR CIGS
THROUGH 18Z. LOW CONFIDENCE. MOST OF THE SHORT TERM MODELS KEEP
THE TERMINALS AT VFR...HOWEVER...THE HRRR AND CURRENT SATELLITE
TRENDS INDICATE STRATUS MAY IMPACT THE REGION THROUGH AT LEAST
18Z. OTHERWISE...MODERATE ONSHORE FLOW THIS AFTERNOON WITH LIKELY
RETURN OF MVFR AND POSSIBLE IFR CIGS AROUND MIDNIGHT.
VICINITY OF KSFO...POSSIBLE MVFR CIGS THROUGH THE EARLY MORNING
HOURS. VERY LOW CONFIDENCE. MODERATE ONSHORE FLOW THIS
AFTERNOON...WITH WESTERLY WIND GUSTS TO 25 KT.
KSFO BRIDGE APPROACH...THE APPROACH MAY BE IMPACTED BY PATCHY
STRATUS AN HOUR LATER THAN THE TERMINAL.
MONTEREY BAY AREA TERMINALS...MVFR CIGS THROUGH 19Z...LOW CONFIDENCE.
STRATUS LOOKS TO BE FILLING IN QUICKLY AND IS FORECAST TO PERSIST
THROUGH THE LATE MORNING HOURS. MODERATE ONSHORE FLOW THIS
AFTERNOON WITH A RETURN OF STRATUS JUST BEFORE MIDNIGHT.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...SF BAY FROM 2 PM
SCA...MRY BAY FROM 2 PM
SCA...PIGEON PT TO PT PINOS 0-10 NM FROM 2 PM
SCA...PT ARENA TO PT REYES 0-10 NM FROM 2 PM
SCA...PT REYES TO PIGEON PT 0-10 NM FROM 2 PM
SCA...PT ARENA TO PIGEON PT 10-60 NM FROM 2 PM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM FROM 2 PM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
&&
$$
PUBLIC FORECAST: LARRY
AVIATION/MARINE: RILEY
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FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
449 AM PDT WED MAY 29 2013
...BECOMING MUCH HOTTER AND DRIER BY FRIDAY AND SATURDAY...
.DISCUSSION...AS OF 3:25 AM PDT WEDNESDAY...KMUX RADAR SHOWS THAT
ECHOS HAVE FINALLY EXITED OUR CWA TO THE EAST ALTHOUGH IN THE PAST
HOUR LIGHT RAIN WAS REPORTED IN SANTA ROSA. SO...STILL A FEW
POCKETS OF LOW ELEVATION RAIN. SATELLITE FOG PRODUCT INDICATES
POCKETS OF CLOUDS ACROSS MOST OF THE COAST AND INTO PART OF THE SF
BA REGION. RIGHT NOW FOG FORMATION DOES LOOK UNLIKELY. LOOK FOR
CLOUDS TO DISSIPATE THROUGH THE DAY WITH GENERALLY SUNNY
CONDITIONS BY AFTERNOON WITH HIGHS IN THE 60S AT THE COAST AND 70S
INLAND.
MAIN WEATHER STORY WILL BE THE RETURN OF MUCH WARMER WEATHER AS A
RIDGE OF HIGH PRESSURE BUILDS IN FROM THE PACIFIC WHILE THE FLOW
AT THE SURFACE BECOMES MOSTLY OFFSHORE. ALTHOUGH 850 MB HEIGHTS
AREN`T THAT IMPRESSIVE (JUST 584-586 DM) 850 TEMPS WILL WARM TO
AROUND 24 C AND WILL COMBINE WITH A FAVORABLE FLOW AT THE SURFACE
TO INCREASE HIGHS EACH DAY WITH THE WARMEST READINGS FORECAST FOR
SATURDAY. BY THAT DAY HIGHS WILL BE IN THE 70S AND 80S AT THE
COAST WITH 90S TO LOWER 100S FOR INLAND SPOTS.
LOOKING AT VARIOUS MODEL DATA PLUS THE HEART WARNING SYSTEM
INDICATES THAT A POSSIBILITY OF HEAT PRODUCTS BEING NEEDED ON
SATURDAY -- ESPECIALLY IF THE THERMAL TROUGH SET UP OFF THE COAST
AND HIGHS ARE ON THE UPPER RANGE OF GUIDANCE VALUES. IT IS STILL A
FEW DAYS OFF, SO WILL WAIT TO SEE WHAT THE NEWEST NUMBERS SHOW
OVER THE NEXT 36 HOURS. IMPORTANT TO NOTE THAT THE ANOMALY
INFORMATION SHOWS THIS EVENT WOULD BE AT MOST 2 STANDARD
DEVIATIONS ABOVE NORMAL FOR TEMPERATURES (AND JUST ABOUT 1 ABOVE
NORMAL FOR HEIGHTS) WHICH WOULD GIVE WEIGHT TO IT FALLING SHORT OF
RECORD BREAKING HEAT FOR MOST SPOTS.
ONSHORE FLOW WILL BEGIN TO RETURN ON SUNDAY AND MOVE BACK ACROSS
OUR AREA BY MONDAY. THIS WILL LEAD TO A RETURN TO MORE SEASONABLE
VALUES THROUGH AT LEAST NEXT WEDNESDAY -- 60S TO LOWER 70S AT THE
COAST WITH 70S AND 80S FOR INLAND SPOTS.
&&
.AVIATION...AS OF 4:40 AM PDT WEDNESDAY...POSSIBLE MVFR CIGS
THROUGH 18Z. LOW CONFIDENCE. MOST OF THE SHORT TERM MODELS KEEP
THE TERMINALS AT VFR...HOWEVER...THE HRRR AND CURRENT SATELLITE
TRENDS INDICATE STRATUS MAY IMPACT THE REGION THROUGH AT LEAST
18Z. OTHERWISE...MODERATE ONSHORE FLOW THIS AFTERNOON WITH LIKELY
RETURN OF MVFR AND POSSIBLE IFR CIGS AROUND MIDNIGHT.
VICINITY OF KSFO...POSSIBLE MVFR CIGS THROUGH THE EARLY MORNING
HOURS. VERY LOW CONFIDENCE. MODERATE ONSHORE FLOW THIS
AFTERNOON...WITH WESTERLY WIND GUSTS TO 25 KT.
KSFO BRIDGE APPROACH...THE APPROACH MAY BE IMPACTED BY PATCHY
STRATUS AN HOUR LATER THAN THE TERMINAL.
MONTEREY BAY AREA TERMINALS...MVFR CIGS THROUGH 19Z...LOW CONFIDENCE.
STRATUS LOOKS TO BE FILLING IN QUICKLY AND IS FORECAST TO PERSIST
THROUGH THE LATE MORNING HOURS. MODERATE ONSHORE FLOW THIS
AFTERNOON WITH A RETURN OF STRATUS JUST BEFORE MIDNIGHT.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...SF BAY FROM 2 PM
SCA...MRY BAY FROM 2 PM
SCA...PIGEON PT TO PT PINOS 0-10 NM FROM 2 PM
SCA...PT ARENA TO PT REYES 0-10 NM FROM 2 PM
SCA...PT REYES TO PIGEON PT 0-10 NM FROM 2 PM
SCA...PT ARENA TO PIGEON PT 10-60 NM FROM 2 PM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM FROM 2 PM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
&&
$$
PUBLIC FORECAST: BELL
AVIATION/MARINE: RILEY
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
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WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS NEW YORK NY
145 PM EDT WED MAY 29 2013
.SYNOPSIS...
A WARM FRONT PUSHES NORTH THROUGH THE REGION TODAY...WITH HIGH
PRESSURE BUILDING IN ITS WAKE. A BERMUDA HIGH DOMINATES OUR
WEATHER THURSDAY NIGHT THROUGH SATURDAY NIGHT. A PRE-FRONTAL
TROUGH MOVES INTO THE REGION SUNDAY...FOLLOWED BY A COLD FRONT
APPROACHING FROM THE WEST SUNDAY NIGHT...THEN CROSSING THE TRI-
STATE ON MONDAY. CANADIAN HIGH PRESSURE THEN BUILDS IN MONDAY
NIGHT AND TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE WARM FRONT IS A LITTLE SLOWER PROGRESSING NORTHWARD THAN
PREVIOUSLY FORECAST...BUT STILL THINK IT SHOULD PASS NORTH OF THE
REGION IN THE NEXT FEW HOURS. CLOUD COVER CONTINUES TO ERODE AND
BEGINNING TO SEE TEMPERATURES RISE WITH WARM ADVECTION TAKING
PLACE WITH INCREASING SOUTHWEST FLOW. ADJUSTED HIGH TEMPERATURES
DOWN A FEW DEGREES DUE TO SLOWER PROGRESSION OF FRONT AND
LINGERING CLOUD COVER.
FOCUS THEN SHIFTS TO THE POSSIBILITY OF CONVECTION THIS AFTERNOON.
INSTABILITY INCREASING ACROSS THE INTERIOR AND LOWER HUDSON
VALLEY AS CLOUDS ERODE AND HEATING TAKES PLACE. SPC MESOANALYIS IS
SHOWING 500 TO 1000 J/KG OF MLCAPE WITH LATEST RAP FCST INCREASING
CAPES SOME MORE AS THE AFTERNOON PROGRESSES. LAST SEVERAL RUNS OF
THE HRRR MODEL HAVE BEEN SHOWING A CLUSTER OF STORMS MOVING IN TO
OUR NW COUNTIES AROUND 21Z AND SHIFTING EASTWARD THROUGH 00Z. USED
THIS IDEA FOR UPDATING POP GRIDS WITH LIKELIHOOD ACROSS LOWER
HUDSON VALLEY AND INTERIOR CONNECTICUT WITH CHANCE POPS FURTHER
SOUTH. CONFIDENCE IN SEVERE POTENTIAL REMAINS LOW...BUT PORTIONS OF
AREA REMAIN IN A SLIGHT RISK. THE MAIN THREATS APPEAR TO BE
DAMAGING WINDS AND HAIL. PW VALUES AROUND 1.6 COULD ALSO LEAD TO
THE POSSIBILITY OF A PERIOD OF HEAVY RAIN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
THE THREAT FOR THUNDERSTORMS...ESP SEVERE...DIMINISHES QUICKLY
AFTER SUNSET WITH THE LOSS OF DAYTIME HEATING. KEPT THE MENTION OF
LINGERING ISO TO SCT THUNDERSTORMS IN THROUGH 06Z...THEN HAVE
DRYING OUT AS THE BERMUDA HIGH PUSHES INTO THE REGION...AND
SUBSIDENCE BEGINS TO DOMINATE ALOFT. THE PERSISTENT SOUTHWESTERLY
FLOW DOES KEEP WARM...MOIST AIR IN THE AREA...SO PATCHY FOG WILL
BE POSSIBLE AGAIN TONIGHT WITH LIGHT WINDS.
HIGH PRESSURE CONTINUES TO IMPACT THE REGION THROUGH THE DAY
THURSDAY...PRODUCING GENERALLY QUIET CONDITIONS.
HOWEVER...EXPECTING A VERY WARM DAY WITH TEMPS WELL ABOVE NORMAL
REACHING NEAR 90 OVER THE NYC METRO AREA...AND INTO THE MID TO
UPPER 80S ELSEWHERE. SEA BREEZE DEVELOPMENT IS EXPECTED DURING THE
AFTN WHICH COULD HELP KEEP THE COASTS SLIGHTLY COOLER. THESE WARM
TEMPS COMBINED WITH THE VERY MOIST AIR WILL PUSH INSTABILITY
VALUES INLAND UP TO AROUND 1000 J/KG AGAIN. HAVE INCLUDED A SLIGHT
CHC OF TSTORMS OVER THIS AREA...WITH PSBL DIURNAL DEVELOPMENT.
TEMP GUIDANCE MORE IN LINE FOR LOWS TONIGHT...AND HIGHS
TOMORROW...SO CHOSE A BLEND OF THE MET/MAV.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
NAM/GFS/ECMWF FAIRLY SIMILAR THURSDAY NIGHT-FRIDAY NIGHT SO USED A
BLEND. DEEP LAYERED RIDGING BUILDS IN DURING THIS TIME FRAME -
ALLOWING FOR DRY AND UNSEASONABLY WARM TO HOT CONDITIONS. THE GFS
WAS ALONE IN SUGGESTING AIR MASS CONVECTION FRIDAY
AFTERNOON/EVENING...SO GIVEN SUBSIDENCE UNDER THE RIDGE...DID NOT
FORECAST.
GFS/ECMWF REMAIN FAIRLY SIMILAR WITH LARGE SCALE FEATURES
SATURDAY-TUESDAY...WHILE CMC REMAINS SLOW OUTLIER. USED ECMWF/GFS
BLEND IN THIS TIME FRAME DUE TO REASONABLE AGREEMENT.
RIDGE AXIS SLIDES TO THE EAST SATURDAY AND SATURDAY NIGHT...SO HAVE
SLIGHT CHANCE POPS FOR SHRA/TSRA OVER FAR NW ZONES SATURDAY
AFTERNOON/EARLY EVENING TO REFLECT POTENTIAL FOR DIURNAL CONVECTION
FARTHEST AWAY FROM THE RIDGE AXIS. OTHERWISE IT SHOULD BE DRY
THROUGH SATURDAY NIGHT. COULD SEE SOME PATCHY FOG LATE SATURDAY
NIGHT OVER EASTERN SECTIONS.
POTENTIAL FOR PASSING SHORTWAVE IN SW FLOW ALOFT...ALONG WITH A
PRE-FRONTAL TROUGH MOVING IN WESTERN ZONES WARRANTS CHANCE POPS NW
1/2 AND SLIGHT CHANCE POPS SE 1/2 OF THE CWA SUNDAY. APPROACHING
700-500 HPA SHORTWAVE SUNDAY NIGHT THAT MOVES THROUGH ON
MONDAY...ALONG WITH ASSOCIATED COLD FRONT AT THE SURFACE...WARRANTS
CHANCE POPS FOR SHRA/TSRA BOTH PERIODS. GIVEN ANTICIPATED STRENGTH
OF FRONT...CANNOT RULE OUT ISOLATED STRONG TO POSSIBLY SEVERE STORMS
ON MONDAY. ALSO COULD SEE SOME PATCHY FOG AGAIN LATE SUNDAY NIGHT
OVER EASTERN SECTIONS.
DEEP UPPER TROUGH BUILDS IN OVER THE NE US/MID ATLANTIC STATES
MONDAY NIGHT AND TUESDAY. FORCING FROM ARRIVING TROUGH WARRANTS A
CHANCE OF SHOWERS IN THE EVENING...TAPERING OF TO DRY CONDITIONS BY
TUESDAY MORNING FROM NW TO SE.
FOR TEMPERATURES IN THE LONG TERM...
FOR LOWS THURSDAY NIGHT USED A MAV/MET BLEND WITH VALUES AROUND 10
DEGREES ABOVE NORMAL. USED A BLEND OF MAV/MET GUIDANCE WITH NAM
2-METER TEMPERATURES AND A MIX DOWN FROM 825 HPA PER BUFKIT
SOUNDINGS FOR HIGHS ON FRIDAY WITH VALUES AROUND 15 DEGREES ABOVE
NORMAL - MAINLY FROM THE UPPER 80S TO LOWER 90S - EXCEPT FROM AROUND
80-MID 80S NEAR THE IMMEDIATE COAST AND THE TWIN FORKS OF LONG
ISLAND.
USED A BLEND OF MEX/MEX ENSEMBLE MEAN/ECE/WPC GUIDANCE FOR
TEMPERATURES FRIDAY NIGHT-TUESDAY. WELL ABOVE NORMAL TEMPERATURES
ARE EXPECTED THROUGH SUNDAY...THOUGH WILL SEE TEMPERATURES LOWER A
TAD EACH DAY. TEMPERATURES SHOULD BE NEAR NORMAL ON MONDAY...THEN
BELOW NORMAL ON TUESDAY.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
A WARM FRONT WILL CONTINUE TO MOVE THROUGH THE AREA THIS AFTERNOON.
MAINLY VFR THROUGH THE TAF PERIOD. ANY SHRA/TSTORMS THAT OCCUR AT
THE TERMINALS WILL LIKELY LOWER THE CIGS/VIS...POSSIBLY TO IFR FOR
A BRIEF TIME. MODERATE CONFIDENCE ON THE SW WINDS THROUGH THE
AFTERNOON WITH A SEA BREEZE COMPONENT AT KJFK AND KISP.
TSTM DEVELOPMENT IS POSSIBLE N AND W OF THE CITY IN THE AFTN. HIGHEST
POTENTIAL IS AT KSWF/KHPN/KBDR AND USED A TEMPO GROUP. ADDED VCTS
TO LGA SHOWING THAT SOME TSTORMS MAY MAKE IT THAT FAR SOUTH BUT
THERE IS STILL UNCERTAINTY REGARDING THE COVERAGE OF THE STORMS.
COULD ALSO SEE LINGERING SHOWERS OVER LONG ISLAND LATE THIS
EVENING BUT CONFIDENCE TOO LOW TO INCLUDE AT THIS TIME.
FOG POSSIBLE TONIGHT...MAINLY AT COASTAL TERMINALS. WITH 5-10KT
WINDS...COULD BE PATCHY IN NATURE. DID NOT GO IFR TONIGHT BUT THIS
MAY NEED TO BE RE-EVALUATED.
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)
KEWR FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR ANY SHRA/TSRA
THIS AFTERNOON.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR ANY SHRA/TSRA
THIS AFTERNOON.
KLGA FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR ANY SHRA/TSRA
THIS AFTERNOON.
KTEB FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR ANY SHRA/TSRA
THIS AFTERNOON.
KHPN FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR ANY SHRA/TSRA
THIS AFTERNOON.
KISP FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED FOR ANY SHRA/TSRA
THIS AFTERNOON.
.OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY...
.THURSDAY-FRIDAY...MAINLY VFR.
.FRIDAY NIGHT-SATURDAY...MVFR FOG/STRATUS POSSIBLE OVER EASTERN
TERMINALS LATE AT NIGHT/EARLY IN THE MORNING. SLIGHT CHANCE OF
AFTERNOON/EARLY EVENING SHRA/TSRA FROM CITY TERMINALS ON N AND W.
.SATURDAY NIGHT...MAINLY VFR.
.SUNDAY-MONDAY...MVFR OR LOWER POSSIBLE IN SHRA/TSRA.
&&
.MARINE...
WITH PERSISTENT SOUTHWESTERLY FLOW THROUGH TONIGHT...ISSUED SCA FOR
OCEAN WATERS TONIGHT WITH GREATER CONFIDENCE IN SEEING SEAS
AROUND 5 FT THROUGH THE EARLY MORNING HOURS. OTHERWISE...EXPECTING
SUB-SCA CONDITIONS LASTING THROUGH THURSDAY.
SUB-SCA CONDITIONS ARE EXPECTED OVER NEW YORK HARBOR...LONG ISLAND
SOUND AND THE BAYS OF LONG ISLAND THURSDAY NIGHT THROUGH SATURDAY
NIGHT. ON THE OCEAN A PERSISTENT SW-S SWELL AND SW FLOW COULD BUILD
SEAS TO SCA LEVELS MAINLY THIS WEEKEND.
GUSTS TO 25 KT ARE POSSIBLE ON ALL WATERS ON SUNDAY.
&&
.HYDROLOGY...
QPF BETWEEN 1/4 AND 1/2 INCH EXPECTED THROUGH THIS AFTERNOON.
SOME LOCALLY HEAVIER AMOUNTS ARE POSSIBLE IN ANY EMBEDDED
CONVECTION LATE TONIGHT. TSTM DEVELOPMENT WED AFTERNOON COULD ALSO
PRODUCE LOCAL DOWNPOURS.
WIDESPREAD SIGNIFICANT PRECIPITATION OF 1/2 INCH OR MORE IS NOT
EXPECTED THROUGH THE UPCOMING WEEKEND. HOWEVER...ANY STRONGER
CONVECTION COULD PRODUCE LOCALLY HEAVY RAINFALL SATURDAY THROUGH
MONDAY...WHICH COULD RESULT IN LOCALIZED MINOR POOR DRAINAGE/URBAN
FLOODING.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 6 PM THIS EVENING
TO 6 AM EDT THURSDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...MALOIT/SEARS
NEAR TERM...SEARS/DS
SHORT TERM...SEARS
LONG TERM...MALOIT
AVIATION...LN
MARINE...MALOIT/SEARS/DS
HYDROLOGY...MALOIT/SEARS
AREA FORECAST DISCUSSION
NWS ALBANY NY
136 PM EDT WED MAY 29 2013
.SYNOPSIS...
A WARM FRONT WILL MOVE THROUGH REGION EARLY IN THE AFTERNOON. A
DISTURBANCE WILL MOVE IN SHORTLY THEREAFTER PRODUCING SCATTERED
SHOWERS AND THUNDERSTORMS. SOME OF THE STORMS MIGHT GET STRONG TO
LOCALLY SEVERE...PRODUCING GUSTY WIND AND POSSIBLY LARGE HAIL. ONCE
THIS DISTURBANCE MOVES BY TONIGHT...THE THREAT OF THUNDERSTORMS WILL
DIMINISH AND IT WILL TURN RATHER HOT FOR THE REST OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
SEVERE THUNDERSTORMS STILL POSSIBLE THIS AFTERNOON INTO THIS
EVENING...
AS OF 1230 PM EDT...ISENTROPIC LIFT HAD ALL BUT MOVE NORTH OF THE
REGION. STILL SOME SHOWERS EXITING THE BERKSHIRES. THE SURFACE WARM
FRONT WAS NOT FAR AWAY...ABOUT TO WORK INTO OUR REGION. CLEARING WAS
ACTUALLY AHEAD OF SURFACE FRONT AND BASED ON SATELLITE
PICTURES...MUCH OF OUR AREA LOOKS TO RECEIVE SUNSHINE BY EARLY
AFTERNOON.
SO THE HEATING IS ON...ALTHOUGH TEMPERATURES WERE STILL ONLY IN THE
60S IN THE HUDSON VALLEY...STILL WEDGED IN A MARINE LAYER.
HOWEVER...BASED ON WHAT IS HAPPENING UPSTREAM...WE BELIEVE THIS
MARINE LAYER WILL ERODE AWAY WITH TIME.
EXPECT INSTABILITY TO RAMP DURING THE AFTERNOON HOURS WHICH SHOULD
LEAD TO SCATTERED SHOWERS AND STORMS AS DISTURBANCE OVER THE GREAT
LAKES WORK INTO OUR REGION DURING THE AFTERNOON. THIS ALL WILL LEAD
TO THOSE SCATTERED SHOWERS AND THUNDERSTORMS.
LAPS DATA ALREADY INDICATED SBCAPES NEAR 500 J/KG TO THE WEST OF THE
HUDSON VALLEY.
FOR THIS UPDATE...DID SCALE BACK COVERAGE TO SCATTERED (AS THE NEW
NAM12 INDICATED LESS COVERAGE) BUT CERTAINLY KEPT ALL THE STRONG
WORDING IN (POSSIBLE DAMAGING WIND/LARGE HAIL AND HEAVY RAINFALL).
RE-TOOLED HOURLY GRIDS LOWERING CURRENT TEMPERATURES BUT NOT
TOUCHING AFTERNOON HIGH TEMPERATURES. ALSO...ACTUALLY DECREASED
CLOUD A LITTLE AND AGAIN SCALED BACK FROM 60 POPS TO 50 (SCATTERED
COVERAGE).
THE NAM12...LOCAL HIRES WRF AND 3KM HRRR STILL ALL INDICATED
CONVECTION DEVELOPING ACROSS WESTERN AND CENTRAL NY DURING THE
EARLY AFTN. THIS ACTIVITY WILL SPREAD INTO OUR AREA FOR THE MID
AFTERNOON THROUGH THE EVENING HOURS.
THERE ARE SEVERAL FACTORS WHICH POINT TO THE POTENTIAL FOR SEVERE
THUNDERSTORMS. BECAUSE OF THE STRENGTH OF THE LLJ...0-6 KM BULK SHEAR
WITH BE AROUND 30-40 KTS. 0-3 KM HELICITY VALUES ARE EXPECTED TO
BE AROUND 200 M2/S2 AND 0-1 KM HELICITY VALUES ARE ALSO VERY
IMPRESSIVE...WITH 100-200 M2/S2 BY EVENING. WHILE MID LEVEL LAPSE
RATES AREN/T OVERLY STRONG...VALUES OF 6-6.5 DEGREES C/KM WILL BE
SUFFICIENT FOR PRODUCING UPDRAFTS CAPABLE OF SEVERE WIND/HAIL.
WHILE THE MAIN THREAT WILL BE DAMAGING WINDS...THE IMPRESSIVE
HELICITY VALUES AND THE FACT THAT THIS SAME SYSTEM PRODUCED
TORNADOES LAST EVENING JUST UPSTREAM ACROSS LOWER MICHIGAN WOULD
POINT TO THE POTENTIAL FOR AN ISOLATED TORNADO OR TWO. THE
NAM12/GFS/AND ECMWF ALL DID SHOW SIGNIFICANT TORNADO PARAMETERS IN
EXCESS OF 1 AT SOME LOCATION IN OUR AREA...SO THE TORNADIC
POTENTIAL SHOULD NOT BE IGNORED. SPC AGREES WITH THIS ASSESSMENT
AND HAS OUR AREA IN A SLIGHT RISK...WITH A 5% PROBABILITY FOR A
TORNADO WITHIN 25 MI OF ANY PARTICULAR LOCATION.
THE MAIN INHIBITING FACTOR WILL BE HAVING ENOUGH INSTABILITY...BUT
EVEN THAT MIGHT NOT BE SOME MUCH OF AN INHIBITOR AS THERE ARE PLENTY
OF BREAKS OF SUNSHINE UPSTREAM AT THIS TIME.
MAX TEMPS THIS AFTERNOON WILL RANGE FROM THE MID 70S TO LOW 80S.
WITH THE LOSS OF HEATING...AND WITH THE SHORTWAVE MOVING TO THE
EAST OF THE AREA...THUNDERSTORM POTENTIAL WILL DIMINISH BY LATE
THIS EVENING. IT SHOULD CLEAR OUT...ALTHOUGH THERE WILL BE
POTENTIAL FOR PATCHY FOG IN THOSE AREAS THAT RECEIVE RAINFALL. MIN
TEMPS WILL BE IN THE 50S TO LOW 60S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
WARM AND MUGGY WEATHER IS EXPECTED FOR THE SHORT TERM PERIOD AS
OUR REGION WILL BE DOMINATED BY A STRONG RIDGE AT 500 HPA CENTERED
OVER THE MID ATLANTIC REGION. 850 HPA TEMPS WILL SURGE TO 16-18
DEGREES C...SO MAX TEMPS WILL REACH THE UPPER 80S TO LOW 90S FOR
BOTH THURSDAY AND FRIDAY. OVERNIGHT LOWS WILL BE WARM AND
STICKY...WITH MAINLY UPPER 50S TO MID 60S AT NIGHT.
WHILE IT SHOULD BE WARM ENOUGH ALOFT TO KEEP A CAP ON ANY
CONVECTION...WE WILL GO WITH A SLIGHT CHC FOR A SHOWER OR
THUNDERSTORM ON THURSDAY AFTN IN CASE ANYTHING IS ABLE TO DEVELOP.
FRIDAY LOOKS EVEN MORE CAPPED...SO WE WILL KEEP THE FORECAST
COMPLETELY DRY FOR FRIDAY WITH A MOSTLY SUNNY TO PARTLY SUNNY SKY.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
HEAT CONTINUES INTO THE FIRST PART OF THE WEEKEND WITH HIGHS
SATURDAY WELL IN THE 80S TO NEAR 90. COLD FRONT AND AMPLIFYING
NORTHERN STREAM UPPER ENERGY APPROACH SUNDAY...TRACKING THROUGH OUR
REGION THE BEGINNING OF THE WEEK...WITH EXACT TIMING TO BE
DETERMINED. SINCE THE EXACT TIMING IS UNKNOWN...INCREASING CHANCES
FOR SHOWERS AND THUNDERSTORMS SUNDAY AND SUNDAY NIGHT...BUILDING
INTO THE MID HUDSON VALLEY AND WESTERN NEW ENGLAND LATER SUNDAY
NIGHT AND MONDAY. DRYING AND COOLING EXPECTED ONCE THE FRONT
EXITS...MONDAY NIGHT AND TUESDAY.
SOME STRONG THUNDERSTORMS ARE POSSIBLE SUNDAY AFTERNOON THROUGH
MONDAY AFTERNOON..DEPENDING ON THE EXACT TIMING OF THE FRONT. THERE
IS A DECENT CONSENSUS FOR A NOTICEABLE COOL DOWN AFTER THE FRONTAL
PASSAGE. HIGHS SUNDAY IN THE UPPER 70S TO MID 80S...COOLING TO HIGHS
IN THE UPPER 60S TO MID 70S MONDAY AND MID 60S TO LOWER 70S TUESDAY.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
CEILINGS AND VISIBILITIES WILL BE MAINLY VFR...THROUGH THE
AFTERNOON AND INTO THE EVENING AS A WARM FRONT TRACKS THROUGH THE
REGION. SOME ORGANIZED THUNDERSTORM ACTIVITY IS POSSIBLE DURING THE
LATE AFTERNOON AND EARLY EVENING HOURS. THIS CONVECTION WOULD LIKELY
RESULT IN MVFR CIGS AND VSBYS AS WELL AS INCREASED WINDS. HAVE
INDICATED A TEMPO GROUP AT ALL TAF SITES WITH WINDS 25020G35 KTS.
THE ORGANIZED CONVECTION IS EXPECTED TO MOVE OUT BY MID EVENING...
SO JUST INDICATING VCSH AFTER 00Z. AFTER 06Z EXPECT SOME FOG WITH
MAINLY MVFR CONDITIONS...EXCEPT LIFR AT KGFL.
THU MORNING FA WILL BE CLEARLY IN THE WARM SECTOR WITH MAINLY P6M
BKN035 CONDITIONS EXPECTED THROUGH 18Z THU.
WINDS WILL BE SOUTHWEST AT LESS THAN 10 KTS AT MOST TAF SITES
THROUGH THIS EVENING EXCEPT HIGHER GUSTS IN CONVECTION AS MENTIONED
EARLIER. WINDS WILL BE LIGHT AND VARIABLE OVERNIGHT AND THEN
WEST AROUND 10 KTS ON THURSDAY.
OUTLOOK...
THU-SAT...VFR/MVFR. SLIGHT CHC PM -TSRA EACH DAY. LATE NIGHT AND/OR
EARLY MORNING MVFR/IFR ASSOC WITH FOG POSSIBLE.
SUN-MON...VFR/MVFR. CHC -SHRA/-TSRA.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS OVER THE NEXT SEVERAL DAYS. A WETTING
RAINFALL OCCURRED IN MOST AREAS EARLY THIS MORNING AND ADDITIONAL
SHOWERS AND THUNDERSTORMS ARE POSSIBLE TODAY INTO THIS EVENING.
RH VALUES WILL ONLY DROP TO 55 TO 70 PERCENT TODAY. S-SW WINDS AT
5-15 MPH ARE EXPECTED TODAY.
W-SW WINDS WILL BE AROUND 5-10 MPH TONIGHT WITH RH VALUES RECOVERING
TO NEAR 100 PERCENT. AN ISOLATED SHOWER OR THUNDERSTORM IS POSSIBLE
TOMORROW WITH RH VALUES DROPPING 40 TO 55 PERCENT TOMORROW AFTERNOON.
&&
.HYDROLOGY...
NO WIDESPREAD HYDROLOGIC CONCERNS OVER THE NEXT FIVE DAYS ACROSS
THE HSA.
SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE REGION TODAY. PWAT
VALUES WILL BE ABOVE NORMAL...WITH VALUES UP TO 1.75 INCHES...SO
ANY SHOWER OR THUNDERSTORM IS CAPABLE OF PRODUCING TORRENTIAL
DOWNPOURS. ALTHOUGH WIDESPREAD RIVER FLOODING IS NOT
EXPECTED...SMALL STREAM...POOR DRAINAGE...OR URBAN FLOODING WILL
BE POSSIBLE DEPENDING ON THE EXACT TRACK OF SHOWERS AND
THUNDERSTORMS...ESPECIALLY IF SEVERAL THUNDERSTORMS TRACK OVER THE
SAME LOCATION. 3 HR FFG FROM THE NERFC IS AROUND 2-3 INCHES.
ISOLATED SHOWERS OR THUNDERSTORMS ARE POSSIBLE ON THURSDAY
AFTERNOON. OTHERWISE...IT WILL BE FAIRLY DRY THROUGH THE END OF
THE WORK WEEK. ADDITIONAL SHOWERS OR THUNDERSTORMS ARE POSSIBLE
OVER THE WEEKEND.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV
SHORT TERM...FRUGIS
LONG TERM...NAS
AVIATION...11
FIRE WEATHER...FRUGIS
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
1230 PM EDT WED MAY 29 2013
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A WARM FRONT
WILL MOVE THROUGH THE REGION THIS MORNING...ESPECIALLY FOR AREAS TO
THE NORTH OF INTERSTATE 90. AS AN UPPER LEVEL DISTURBANCE MOVES
CLOSE TO THE REGION...SOME STRONG THUNDERSTORMS ARE POSSIBLE THIS
AFTERNOON THROUGH THIS EVENING. MUCH WARMER TEMPERATURES AND MUGGY
CONDITIONS ARE EXPECTED FOR THE REMAINDER OF THE WEEK...WITH SOME
ADDITIONAL THUNDERSTORMS POSSIBLE OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
SEVERE THUNDERSTORMS STILL POSSIBLE THIS AFTERNOON INTO THIS
EVENING...
AS OF 1230 PM EDT...ISENTROPIC LIFT HAD ALL BUT MOVE NORTH OF THE
REGION. STILL SOME SHOWERS EXITING THE BERKSHIRES. THE SURFACE WARM
FRONT WAS NOT FAR AWAY...ABOUT TO WORK INTO OUR REGION. CLEARING WAS
ACTUALLY AHEAD OF SURFACE FRONT AND BASED ON SATELLITE
PICTURES...MUCH OF OUR AREA LOOKS TO RECEIVE SUNSHINE BY EARLY
AFTERNOON.
SO THE HEATING IS ON...ALTHOUGH TEMPERATURES WERE STILL ONLY IN THE
60S IN THE HUDSON VALLEY...STILL WEDGED IN A MARINE LAYER.
HOWEVER...BASED ON WHAT IS HAPPENING UPSTREAM...WE BELIEVE THIS
MARINE LAYER WILL ERODE AWAY WITH TIME.
EXPECT INSTABILITY TO RAMP DURING THE AFTERNOON HOURS WHICH SHOULD
LEAD TO SCATTERED SHOWERS AND STORMS AS DISTURBANCE OVER THE GREAT
LAKES WORK INTO OUR REGION DURING THE AFTERNOON. THIS ALL WILL LEAD
TO THOSE SCATTERED SHOWERS AND THUNDERSTORMS.
LAPS DATA ALREADY INDICATED SBCAPES NEAR 500 J/KG TO THE WEST OF THE
HUDSON VALLEY.
FOR THIS UPDATE...DID SCALE BACK COVERAGE TO SCATTERED (AS THE NEW
NAM12 INDICATED LESS COVERAGE) BUT CERTAINLY KEPT ALL THE STRONG
WORDING IN (POSSIBLE DAMAGING WIND/LARGE HAIL AND HEAVY RAINFALL).
RE-TOOLED HOURLY GRIDS LOWERING CURRENT TEMPERATURES BUT NOT
TOUCHING AFTERNOON HIGH TEMPERATURES. ALSO...ACTUALLY DECREASED
CLOUD A LITTLE AND AGAIN SCALED BACK FROM 60 POPS TO 50 (SCATTERED
COVERAGE).
THE NAM12...LOCAL HIRES WRF AND 3KM HRRR STILL ALL INDICATED
CONVECTION DEVELOPING ACROSS WESTERN AND CENTRAL NY DURING THE
EARLY AFTN. THIS ACTIVITY WILL SPREAD INTO OUR AREA FOR THE MID
AFTERNOON THROUGH THE EVENING HOURS.
THERE ARE SEVERAL FACTORS WHICH POINT TO THE POTENTIAL FOR SEVERE
THUNDERSTORMS. BECAUSE OF THE STRENGTH OF THE LLJ...0-6 KM BULK SHEAR
WITH BE AROUND 30-40 KTS. 0-3 KM HELICITY VALUES ARE EXPECTED TO
BE AROUND 200 M2/S2 AND 0-1 KM HELICITY VALUES ARE ALSO VERY
IMPRESSIVE...WITH 100-200 M2/S2 BY EVENING. WHILE MID LEVEL LAPSE
RATES AREN/T OVERLY STRONG...VALUES OF 6-6.5 DEGREES C/KM WILL BE
SUFFICIENT FOR PRODUCING UPDRAFTS CAPABLE OF SEVERE WIND/HAIL.
WHILE THE MAIN THREAT WILL BE DAMAGING WINDS...THE IMPRESSIVE
HELICITY VALUES AND THE FACT THAT THIS SAME SYSTEM PRODUCED
TORNADOES LAST EVENING JUST UPSTREAM ACROSS LOWER MICHIGAN WOULD
POINT TO THE POTENTIAL FOR AN ISOLATED TORNADO OR TWO. THE
NAM12/GFS/AND ECMWF ALL DID SHOW SIGNIFICANT TORNADO PARAMETERS IN
EXCESS OF 1 AT SOME LOCATION IN OUR AREA...SO THE TORNADIC
POTENTIAL SHOULD NOT BE IGNORED. SPC AGREES WITH THIS ASSESSMENT
AND HAS OUR AREA IN A SLIGHT RISK...WITH A 5% PROBABILITY FOR A
TORNADO WITHIN 25 MI OF ANY PARTICULAR LOCATION.
THE MAIN INHIBITING FACTOR WILL BE HAVING ENOUGH INSTABILITY...BUT
EVEN THAT MIGHT NOT BE SOME MUCH OF AN INHIBITOR AS THERE ARE PLENTY
OF BREAKS OF SUNSHINE UPSTREAM AT THIS TIME.
MAX TEMPS THIS AFTERNOON WILL RANGE FROM THE MID 70S TO LOW 80S.
WITH THE LOSS OF HEATING...AND WITH THE SHORTWAVE MOVING TO THE
EAST OF THE AREA...THUNDERSTORM POTENTIAL WILL DIMINISH BY LATE
THIS EVENING. IT SHOULD CLEAR OUT...ALTHOUGH THERE WILL BE
POTENTIAL FOR PATCHY FOG IN THOSE AREAS THAT RECEIVE RAINFALL. MIN
TEMPS WILL BE IN THE 50S TO LOW 60S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
WARM AND MUGGY WEATHER IS EXPECTED FOR THE SHORT TERM PERIOD AS
OUR REGION WILL BE DOMINATED BY A STRONG RIDGE AT 500 HPA CENTERED
OVER THE MID ATLANTIC REGION. 850 HPA TEMPS WILL SURGE TO 16-18
DEGREES C...SO MAX TEMPS WILL REACH THE UPPER 80S TO LOW 90S FOR
BOTH THURSDAY AND FRIDAY. OVERNIGHT LOWS WILL BE WARM AND
STICKY...WITH MAINLY UPPER 50S TO MID 60S AT NIGHT.
WHILE IT SHOULD BE WARM ENOUGH ALOFT TO KEEP A CAP ON ANY
CONVECTION...WE WILL GO WITH A SLIGHT CHC FOR A SHOWER OR
THUNDERSTORM ON THURSDAY AFTN IN CASE ANYTHING IS ABLE TO DEVELOP.
FRIDAY LOOKS EVEN MORE CAPPED...SO WE WILL KEEP THE FORECAST
COMPLETELY DRY FOR FRIDAY WITH A MOSTLY SUNNY TO PARTLY SUNNY SKY.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
HEAT CONTINUES INTO THE FIRST PART OF THE WEEKEND WITH HIGHS
SATURDAY WELL IN THE 80S TO NEAR 90. COLD FRONT AND AMPLIFYING
NORTHERN STREAM UPPER ENERGY APPROACH SUNDAY...TRACKING THROUGH OUR
REGION THE BEGINNING OF THE WEEK...WITH EXACT TIMING TO BE
DETERMINED. SINCE THE EXACT TIMING IS UNKNOWN...INCREASING CHANCES
FOR SHOWERS AND THUNDERSTORMS SUNDAY AND SUNDAY NIGHT...BUILDING
INTO THE MID HUDSON VALLEY AND WESTERN NEW ENGLAND LATER SUNDAY
NIGHT AND MONDAY. DRYING AND COOLING EXPECTED ONCE THE FRONT
EXITS...MONDAY NIGHT AND TUESDAY.
SOME STRONG THUNDERSTORMS ARE POSSIBLE SUNDAY AFTERNOON THROUGH
MONDAY AFTERNOON..DEPENDING ON THE EXACT TIMING OF THE FRONT. THERE
IS A DECENT CONSENSUS FOR A NOTICEABLE COOL DOWN AFTER THE FRONTAL
PASSAGE. HIGHS SUNDAY IN THE UPPER 70S TO MID 80S...COOLING TO HIGHS
IN THE UPPER 60S TO MID 70S MONDAY AND MID 60S TO LOWER 70S TUESDAY.
&&
.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
ANOTHER AREA OF SHOWERS ASSOCIATED WITH AN OLD WEAKENING CONVECTIVE
COMPLEX SHOULD TRACK THROUGH THE REGION THROUGH ABOUT 16Z...REDUCING
CEILINGS AND VISIBILITIES TO PERIODS OF MVFR AND IFR. IFR
CONDITIONS SHOULD DOMINATE AT KPOU AND KPSF WITH MVFR AT KALB AND
KGFL...BUT ALL SITES SHOULD HAVE PERIODS OF MVFR AND IFR.
ONCE THIS AREA OF SHOWERS EXITS AROUND 16Z...CEILINGS AND
VISIBILITIES SHOULD BE MAINLY VFR...THROUGH THE AFTERNOON AND IN TO
THE EVENING AS A WARM FRONT TRACKS THROUGH THE REGION. HOWEVER...
THERE ARE INDICATIONS THAT SOME ORGANIZED THUNDERSTORM ACTIVITY
COULD TRACK THROUGH THE REGION DURING THE LATE AFTERNOON. KEEPING
THE PROB30 INDICATIONS FOR THUNDERSTORMS BECAUSE THERE ARE ABOVE
NORMAL CHANCES FOR THUNDERSTORMS...ALTHOUGH SCATTERED...STILL ABOVE
NORMAL CHANCES. INDICATING MVFR CEILINGS AND VISIBILITIES IN
THUNDERSTORMS FOR NOW...BUT THERE COULD BE IFR FOR BRIEF PERIODS IN
ANY THUNDERSTORMS.
THE ORGANIZED THUNDERSTORM ACTIVITY COULD MOVE OUT DURING THE EARLY
EVENING...SO JUST INDICATING VCSH AFTER 00Z...WITH VFR CONDITIONS AS
THE WARM FRONT SHOULD BE EXITING AND THE WARM SECTOR EXPANDS OVER
THE REGION.
VARIABLE MAINLY SOUTHEAST TO SOUTHWEST WINDS AT LESS THAN 10 KT
THROUGH THE EARLY MORNING...BECOMING SOUTH TO SOUTHWEST AROUND 10 KT
AFTER 16Z...THEN TRENDING MORE SOUTHWEST AT LESS THAN 10 KT BY THIS
EVENING. A STEADY LIGHT WIND THIS EVENING MAY PREVENT ANY FOG FROM
FORMING AFTER ANY THUNDERSTORM ACTIVITY EXITS...BUT TOO EARLY TO
TELL WHEN STORMS WILL EXIT AND HOW MUCH WIND THERE WILL BE ONCE WE
BREAK INTO THE WARM SECTOR.
OUTLOOK...
THU-SUN...VFR/MVFR. CHC PM -TSRA EACH DAY. LATE NIGHT AND/OR
EARLY MORNING MVFR/IFR ASSOC WITH FOG POSSIBLE.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS OVER THE NEXT SEVERAL DAYS. A WETTING
RAINFALL OCCURRED IN MOST AREAS EARLY THIS MORNING AND ADDITIONAL
SHOWERS AND THUNDERSTORMS ARE POSSIBLE TODAY INTO THIS EVENING.
RH VALUES WILL ONLY DROP TO 55 TO 70 PERCENT TODAY. S-SW WINDS AT
5-15 MPH ARE EXPECTED TODAY.
W-SW WINDS WILL BE AROUND 5-10 MPH TONIGHT WITH RH VALUES RECOVERING
TO NEAR 100 PERCENT. AN ISOLATED SHOWER OR THUNDERSTORM IS POSSIBLE
TOMORROW WITH RH VALUES DROPPING 40 TO 55 PERCENT TOMORROW AFTERNOON.
&&
.HYDROLOGY...
NO WIDESPREAD HYDROLOGIC CONCERNS OVER THE NEXT FIVE DAYS ACROSS
THE HSA.
SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE REGION TODAY. PWAT
VALUES WILL BE ABOVE NORMAL...WITH VALUES UP TO 1.75 INCHES...SO
ANY SHOWER OR THUNDERSTORM IS CAPABLE OF PRODUCING TORRENTIAL
DOWNPOURS. ALTHOUGH WIDESPREAD RIVER FLOODING IS NOT
EXPECTED...SMALL STREAM...POOR DRAINAGE...OR URBAN FLOODING WILL
BE POSSIBLE DEPENDING ON THE EXACT TRACK OF SHOWERS AND
THUNDERSTORMS...ESPECIALLY IF SEVERAL THUNDERSTORMS TRACK OVER THE
SAME LOCATION. 3 HR FFG FROM THE NERFC IS AROUND 2-3 INCHES.
ISOLATED SHOWERS OR THUNDERSTORMS ARE POSSIBLE ON THURSDAY
AFTERNOON. OTHERWISE...IT WILL BE FAIRLY DRY THROUGH THE END OF
THE WORK WEEK. ADDITIONAL SHOWERS OR THUNDERSTORMS ARE POSSIBLE
OVER THE WEEKEND.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV
SHORT TERM...FRUGIS
LONG TERM...NAS
AVIATION...NAS
FIRE WEATHER...FRUGIS
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
1006 AM EDT WED MAY 29 2013
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A WARM FRONT
WILL MOVE THROUGH THE REGION THIS MORNING...ESPECIALLY FOR AREAS TO
THE NORTH OF INTERSTATE 90. AS AN UPPER LEVEL DISTURBANCE MOVES
CLOSE TO THE REGION...SOME STRONG THUNDERSTORMS ARE POSSIBLE THIS
AFTERNOON THROUGH THIS EVENING. MUCH WARMER TEMPERATURES AND MUGGY
CONDITIONS ARE EXPECTED FOR THE REMAINDER OF THE WEEK...WITH SOME
ADDITIONAL THUNDERSTORMS POSSIBLE OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
SEVERE THUNDERSTORMS POSSIBLE THIS AFTERNOON INTO THIS
EVENING...
AS OF 1000 AM EDT...BANDS OF SHOWERS AND FEW EMBEDDED RUMBLES OF
THUNDER ARE MOVING ACROSS THE FA. RAINFALL WILL BE LIGHT TO
MODERATE IN INTENSITY. IN THE WAKE OF THESE SHOWERS EXPECT SOME
CLEARING TO DEVELOP WHICH IS ALREADY NOTED ON THE VISIBLE SAT PICS
ACRS PTNS OF WRN AND CNTRL NY. TEMPS THIS MORNING WERE GENERALLY
IN THE 60S
BY LATE THIS MORNING...THE WARM FRONT WILL BE LIFTING NORTH
ACROSS OUR NORTHERN ZONES. THERE STILL MAY BE SOME SHOWERS WITH
THE FRONT ACROSS OUR NORTHERN AREAS...OTHERWISE...THERE WILL BE A
LULL IN THE ACTIVITY ACROSS MUCH OF THE REMAINDER OF THE AREA.
SOME BREAKS OF SUN MAY START TO DEVELOP...ESP FOR VALLEY AREAS
FROM THE CAPITAL REGION ON SOUTH. THE CANADIAN CLOUD MODEL SHOWS
SOME BREAKS STARTING TO DEVELOP BY AROUND 16Z FOR THE HUDSON
VALLEY REGION. WITH A LIGHT S-SW WIND IN PLACE...DEWPOINTS WILL
CONTINUE TO RISE INTO THE LOWER TO MID 60S F.
BY AFTERNOON...A SHORTWAVE TROUGH WILL BE MOVING ACROSS THE TOP OF
DEVELOPING RIDGE ACROSS THE EASTERN CONUS...MOVING FROM THE GREAT
LAKES AND LOWER ONTARIO INTO UPSTATE NY. THIS SHORTWAVE...AIDED BY
A STRONG 30-40 KTS LOW LEVEL JET AT 850 HPA WILL HELP FIRE
CONVECTION IN THE WARM SECTOR.
THE NAM12...LOCAL HIRES WRF AND 3KM HRRR ALL SHOW
CONVECTION DEVELOPING ACROSS WESTERN AND CENTRAL NY DURING THE
EARLY AFTN. THIS ACTIVITY WILL SPREAD INTO OUR AREA FOR THE MID
AFTN THROUGH THE EVENING HOURS.
THERE ARE SEVERAL FACTORS WHICH POINT TO THE POTENTIAL FOR SEVERE
THUNDERSTORMS. BECAUSE OF THE STRENGTH OF THE LLJ...0-6 KM BULK SHEAR
WITH BE AROUND 30-40 KTS. 0-3 KM HELICITY VALUES ARE EXPECTED TO
BE AROUND 200 M2/S2 AND 0-1 KM HELICITY VALUES ARE ALSO VERY
IMPRESSIVE...WITH 100-200 M2/S2 BY EVENING. WHILE MID LEVEL LAPSE
RATES AREN/T OVERLY STRONG...VALUES OF 6-6.5 DEGREES C/KM WILL BE
SUFFICIENT FOR PRODUCING UPDRAFTS CAPABLE OF SEVERE WIND/HAIL.
WHILE THE MAIN THREAT WILL BE DAMAGING WINDS...THE IMPRESSIVE
HELICITY VALUES AND THE FACT THAT THIS SAME SYSTEM PRODUCED
TORNADOES LAST EVENING JUST UPSTREAM ACROSS LOWER MICHIGAN WOULD
POINT TO THE POTENTIAL FOR AN ISOLATED TORNADO OR TWO. THE
NAM12/GFS/AND ECMWF ALL DID SHOW SIGNIFICANT TORNADO PARAMETERS IN
EXCESS OF 1 AT SOME LOCATION IN OUR AREA...SO THE TORNADIC
POTENTIAL SHOULD NOT BE IGNORED. SPC AGREES WITH THIS ASSESSMENT
AND HAS OUR AREA IN A SLIGHT RISK...WITH A 5% PROBABILITY FOR A
TORNADO WITHIN 25 MI OF ANY PARTICULAR LOCATION.
THE MAIN INHIBITING FACTOR WILL BE HAVING ENOUGH INSTABILITY.
THERE ARE PLENTY OF CLOUDS AROUND...EVEN UPSTREAM IN THE WARM
SECTOR WITH LINGERING DEBRIS CLOUDS. IF ENOUGH INSTABILITY ISN/T
REALIZED...STORMS MAY HAVE A DIFFICULT TIME GROWING VERY
TALL...AND THE SEVERE POTENTIAL WOULD BE MINIMIZED. AT THIS
POINT...ALL MODELS SHOW CAPE VALUES OF 1000-1500 J/KG...BUT THE
POTENTIAL FOR SUFFICIENT SURFACE BASED CAPE WILL HAVE TO BE
MONITORED THROUGH THE MORNING HOURS.
MAX TEMPS WILL RANGE FROM THE MID 70S TO LOW 80S. IF MORE CLEARING
OCCURS...MAX TEMPS COULD WIND UP ON THE WARMER END OF THIS
RANGE...ESP FROM THE CAPITAL REGION ON SOUTH.
WITH THE LOSS OF HEATING...AND WITH THE SHORTWAVE MOVING TO THE
EAST OF THE AREA...THUNDERSTORM POTENTIAL WILL DIMINISH BY LATE
THIS EVENING. IT SHOULD CLEAR OUT...ALTHOUGH THERE WILL BE
POTENTIAL FOR PATCHY FOG IN THOSE AREAS THAT RECEIVE RAINFALL. MIN
TEMPS WILL BE IN THE 50S TO LOW 60S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
WARM AND MUGGY WEATHER IS EXPECTED FOR THE SHORT TERM PERIOD AS
OUR REGION WILL BE DOMINATED BY A STRONG RIDGE AT 500 HPA CENTERED
OVER THE MID ATLANTIC REGION. 850 HPA TEMPS WILL SURGE TO 16-18
DEGREES C...SO MAX TEMPS WILL REACH THE UPPER 80S TO LOW 90S FOR
BOTH THURSDAY AND FRIDAY. OVERNIGHT LOWS WILL BE WARM AND
STICKY...WITH MAINLY UPPER 50S TO MID 60S AT NIGHT.
WHILE IT SHOULD BE WARM ENOUGH ALOFT TO KEEP A CAP ON ANY
CONVECTION...WE WILL GO WITH A SLIGHT CHC FOR A SHOWER OR
THUNDERSTORM ON THURSDAY AFTN IN CASE ANYTHING IS ABLE TO DEVELOP.
FRIDAY LOOKS EVEN MORE CAPPED...SO WE WILL KEEP THE FORECAST
COMPLETELY DRY FOR FRIDAY WITH A MOSTLY SUNNY TO PARTLY SUNNY SKY.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
HEAT CONTINUES INTO THE FIRST PART OF THE WEEKEND WITH HIGHS
SATURDAY WELL IN THE 80S TO NEAR 90. COLD FRONT AND AMPLIFYING
NORTHERN STREAM UPPER ENERGY APPROACH SUNDAY...TRACKING THROUGH OUR
REGION THE BEGINNING OF THE WEEK...WITH EXACT TIMING TO BE
DETERMINED. SINCE THE EXACT TIMING IS UNKNOWN...INCREASING CHANCES
FOR SHOWERS AND THUNDERSTORMS SUNDAY AND SUNDAY NIGHT...BUILDING
INTO THE MID HUDSON VALLEY AND WESTERN NEW ENGLAND LATER SUNDAY
NIGHT AND MONDAY. DRYING AND COOLING EXPECTED ONCE THE FRONT
EXITS...MONDAY NIGHT AND TUESDAY.
SOME STRONG THUNDERSTORMS ARE POSSIBLE SUNDAY AFTERNOON THROUGH
MONDAY AFTERNOON..DEPENDING ON THE EXACT TIMING OF THE FRONT. THERE
IS A DECENT CONSENSUS FOR A NOTICEABLE COOL DOWN AFTER THE FRONTAL
PASSAGE. HIGHS SUNDAY IN THE UPPER 70S TO MID 80S...COOLING TO HIGHS
IN THE UPPER 60S TO MID 70S MONDAY AND MID 60S TO LOWER 70S TUESDAY.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
ANOTHER AREA OF SHOWERS ASSOCIATED WITH AN OLD WEAKENING CONVECTIVE
COMPLEX SHOULD TRACK THROUGH THE REGION THROUGH ABOUT 16Z...REDUCING
CEILINGS AND VISIBILITIES TO PERIODS OF MVFR AND IFR. IFR
CONDITIONS SHOULD DOMINATE AT KPOU AND KPSF WITH MVFR AT KALB AND
KGFL...BUT ALL SITES SHOULD HAVE PERIODS OF MVFR AND IFR.
ONCE THIS AREA OF SHOWERS EXITS AROUND 16Z...CEILINGS AND
VISIBILITIES SHOULD BE MAINLY VFR...THROUGH THE AFTERNOON AND IN TO
THE EVENING AS A WARM FRONT TRACKS THROUGH THE REGION. HOWEVER...
THERE ARE INDICATIONS THAT SOME ORGANIZED THUNDERSTORM ACTIVITY
COULD TRACK THROUGH THE REGION DURING THE LATE AFTERNOON. KEEPING
THE PROB30 INDICATIONS FOR THUNDERSTORMS BECAUSE THERE ARE ABOVE
NORMAL CHANCES FOR THUNDERSTORMS...ALTHOUGH SCATTERED...STILL ABOVE
NORMAL CHANCES. INDICATING MVFR CEILINGS AND VISIBILITIES IN
THUNDERSTORMS FOR NOW...BUT THERE COULD BE IFR FOR BRIEF PERIODS IN
ANY THUNDERSTORMS.
THE ORGANIZED THUNDERSTORM ACTIVITY COULD MOVE OUT DURING THE EARLY
EVENING...SO JUST INDICATING VCSH AFTER 00Z...WITH VFR CONDITIONS AS
THE WARM FRONT SHOULD BE EXITING AND THE WARM SECTOR EXPANDS OVER
THE REGION.
VARIABLE MAINLY SOUTHEAST TO SOUTHWEST WINDS AT LESS THAN 10 KT
THROUGH THE EARLY MORNING...BECOMING SOUTH TO SOUTHWEST AROUND 10 KT
AFTER 16Z...THEN TRENDING MORE SOUTHWEST AT LESS THAN 10 KT BY THIS
EVENING. A STEADY LIGHT WIND THIS EVENING MAY PREVENT ANY FOG FROM
FORMING AFTER ANY THUNDERSTORM ACTIVITY EXITS...BUT TOO EARLY TO
TELL WHEN STORMS WILL EXIT AND HOW MUCH WIND THERE WILL BE ONCE WE
BREAK INTO THE WARM SECTOR.
OUTLOOK...
THU-SUN...VFR/MVFR. CHC PM -TSRA EACH DAY. LATE NIGHT AND/OR
EARLY MORNING MVFR/IFR ASSOC WITH FOG POSSIBLE.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS OVER THE NEXT SEVERAL DAYS. A WETTING
RAINFALL OCCURRED IN MOST AREAS EARLY THIS MORNING AND ADDITIONAL
SHOWERS AND THUNDERSTORMS ARE POSSIBLE TODAY INTO THIS EVENING.
RH VALUES WILL ONLY DROP TO 55 TO 70 PERCENT TODAY. S-SW WINDS AT
5-15 MPH ARE EXPECTED TODAY.
W-SW WINDS WILL BE AROUND 5-10 MPH TONIGHT WITH RH VALUES RECOVERING TO
NEAR 100 PERCENT. AN ISOLATED SHOWER OR THUNDERSTORM IS POSSIBLE
TOMORROW WITH RH VALUES DROPPING 40 TO 55 PERCENT TOMORROW AFTERNOON.
&&
.HYDROLOGY...
NO WIDESPREAD HYDROLOGIC CONCERNS OVER THE NEXT FIVE DAYS ACROSS
THE HSA.
SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE REGION TODAY. PWAT
VALUES WILL BE ABOVE NORMAL...WITH VALUES UP TO 1.75 INCHES...SO
ANY SHOWER OR THUNDERSTORM IS CAPABLE OF PRODUCING TORRENTIAL
DOWNPOURS. ALTHOUGH WIDESPREAD RIVER FLOODING IS NOT
EXPECTED...SMALL STREAM...POOR DRAINAGE...OR URBAN FLOODING WILL
BE POSSIBLE DEPENDING ON THE EXACT TRACK OF SHOWERS AND
THUNDERSTORMS...ESPECIALLY IF SEVERAL THUNDERSTORMS TRACK OVER THE
SAME LOCATION. 3 HR FFG FROM THE NERFC IS AROUND 2-3 INCHES.
ISOLATED SHOWERS OR THUNDERSTORMS ARE POSSIBLE ON THURSDAY
AFTERNOON. OTHERWISE...IT WILL BE FAIRLY DRY THROUGH THE END OF
THE WORK WEEK. ADDITIONAL SHOWERS OR THUNDERSTORMS ARE POSSIBLE
OVER THE WEEKEND.
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...FRUGIS
NEAR TERM...FRUGIS/11
SHORT TERM...FRUGIS
LONG TERM...NAS
AVIATION...NAS
FIRE WEATHER...FRUGIS
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
729 AM EDT WED MAY 29 2013
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A WARM FRONT
WILL MOVE THROUGH THE REGION THIS MORNING...ESPECIALLY FOR AREAS TO
THE NORTH OF INTERSTATE 90. AS AN UPPER LEVEL DISTURBANCE MOVES
CLOSE TO THE REGION...SOME STRONG THUNDERSTORMS ARE POSSIBLE THIS
AFTERNOON THROUGH THIS EVENING. MUCH WARMER TEMPERATURES AND MUGGY
CONDITIONS ARE EXPECTED FOR THE REMAINDER OF THE WEEK...WITH SOME
ADDITIONAL THUNDERSTORMS POSSIBLE OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
SEVERE THUNDERSTORMS POSSIBLE THIS AFTERNOON INTO THIS
EVENING...
AS OF 627 AM EDT...A WARM FRONT WAS SITUATED JUST SOUTH OF THE
REGION ACROSS THE CENTRAL PA AND NJ. AHEAD OF THIS WARM
FRONT...ISENTROPIC LIFT/WARM AIR ADVECTION IS ALLOWING FOR BANDS
OF SHOWERS AND ISOLD THUNDERSTORMS ACROSS WESTERN AND CENTRAL NEW
YORK. OVER THE NEXT FEW HOURS...THESE SHOWERS AND EMBEDDED RUMBLES
OF THUNDER WILL MOVE ACROSS OUR AREA...MAINLY THE CENTRAL AND
NORTHERN ZONES. RAINFALL WILL BE LIGHT TO MODERATE IN INTENSITY.
BY THE MID TO LATE MORNING HOURS...THE WARM FRONT WILL BE LIFTING
NORTH ACROSS OUR NORTHERN ZONES. THERE STILL MAY BE SOME SHOWERS
WITH THE FRONT ACROSS OUR NORTHERN AREAS...OTHERWISE...THERE WILL
BE A LULL IN THE ACTIVITY ACROSS MUCH OF THE REMAINDER OF THE
AREA. SOME BREAKS OF SUN MAY START TO DEVELOP...ESP FOR VALLEY
AREAS FROM THE CAPITAL REGION ON SOUTH. THE CANADIAN CLOUD MODEL
SHOWS SOME BREAKS STARTING TO DEVELOP BY AROUND 16Z FOR THE HUDSON
VALLEY REGION. WITH A LIGHT S-SW WIND IN PLACE...DEWPOINTS WILL
CONTINUE TO RISE INTO THE LOWER TO MID 60S F.
BY AFTERNOON...A SHORTWAVE TROUGH WILL BE MOVING ACROSS THE TOP OF
DEVELOPING RIDGE ACROSS THE EASTERN CONUS...MOVING FROM THE GREAT
LAKES AND LOWER ONTARIO INTO UPSTATE NY. THIS SHORTWAVE...AIDED BY
A STRONG 30-40 KTS LOW LEVEL JET AT 850 HPA WILL HELP FIRE
CONVECTION IN THE WARM SECTOR.
THE NAM12...LOCAL HIRES WRF AND 3KM HRRR ALL SHOW
CONVECTION DEVELOPING ACROSS WESTERN AND CENTRAL NY DURING THE
EARLY AFTN. THIS ACTIVITY WILL SPREAD INTO OUR AREA FOR THE MID
AFTN THROUGH THE EVENING HOURS.
THERE ARE SEVERAL FACTORS WHICH POINT TO THE POTENTIAL FOR SEVERE
THUNDERSTORMS. BECAUSE OF THE STRENGTH OF THE LLJ...0-6 KM BULK SHEAR
WITH BE AROUND 30-40 KTS. 0-3 KM HELICITY VALUES ARE EXPECTED TO
BE AROUND 200 M2/S2 AND 0-1 KM HELICITY VALUES ARE ALSO VERY
IMPRESSIVE...WITH 100-200 M2/S2 BY EVENING. WHILE MID LEVEL LAPSE
RATES AREN/T OVERLY STRONG...VALUES OF 6-6.5 DEGREES C/KM WILL BE
SUFFICIENT FOR PRODUCING UPDRAFTS CAPABLE OF SEVERE WIND/HAIL.
WHILE THE MAIN THREAT WILL BE DAMAGING WINDS...THE IMPRESSIVE
HELICITY VALUES AND THE FACT THAT THIS SAME SYSTEM PRODUCED
TORNADOES LAST EVENING JUST UPSTREAM ACROSS LOWER MICHIGAN WOULD
POINT TO THE POTENTIAL FOR AN ISOLATED TORNADO OR TWO. THE
NAM12/GFS/AND ECMWF ALL DID SHOW SIGNIFICANT TORNADO PARAMETERS IN
EXCESS OF 1 AT SOME LOCATION IN OUR AREA...SO THE TORNADIC
POTENTIAL SHOULD NOT BE IGNORED. SPC AGREES WITH THIS ASSESSMENT
AND HAS OUR AREA IN A SLIGHT RISK...WITH A 5% PROBABILITY FOR A
TORNADO WITHIN 25 MI OF ANY PARTICULAR LOCATION.
THE MAIN INHIBITING FACTOR WILL BE HAVING ENOUGH INSTABILITY.
THERE ARE PLENTY OF CLOUDS AROUND...EVEN UPSTREAM IN THE WARM
SECTOR WITH LINGERING DEBRIS CLOUDS. IF ENOUGH INSTABILITY ISN/T
REALIZED...STORMS MAY HAVE A DIFFICULT TIME GROWING VERY
TALL...AND THE SEVERE POTENTIAL WOULD BE MINIMIZED. AT THIS
POINT...ALL MODELS SHOW CAPE VALUES OF 1000-1500 J/KG...BUT THE
POTENTIAL FOR SUFFICIENT SURFACE BASED CAPE WILL HAVE TO BE
MONITORED THROUGH THE MORNING HOURS.
MAX TEMPS WILL RANGE FROM THE MID 70S TO LOW 80S. IF MORE CLEARING
OCCURS...MAX TEMPS COULD WIND UP ON THE WARMER END OF THIS
RANGE...ESP FROM THE CAPITAL REGION ON SOUTH.
WITH THE LOSS OF HEATING...AND WITH THE SHORTWAVE MOVING TO THE
EAST OF THE AREA...THUNDERSTORM POTENTIAL WILL DIMINISH BY LATE
THIS EVENING. IT SHOULD CLEAR OUT...ALTHOUGH THERE WILL BE
POTENTIAL FOR PATCHY FOG IN THOSE AREAS THAT RECEIVE RAINFALL. MIN
TEMPS WILL BE IN THE 50S TO LOW 60S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
WARM AND MUGGY WEATHER IS EXPECTED FOR THE SHORT TERM PERIOD AS
OUR REGION WILL BE DOMINATED BY A STRONG RIDGE AT 500 HPA CENTERED
OVER THE MID ATLANTIC REGION. 850 HPA TEMPS WILL SURGE TO 16-18
DEGREES C...SO MAX TEMPS WILL REACH THE UPPER 80S TO LOW 90S FOR
BOTH THURSDAY AND FRIDAY. OVERNIGHT LOWS WILL BE WARM AND
STICKY...WITH MAINLY UPPER 50S TO MID 60S AT NIGHT.
WHILE IT SHOULD BE WARM ENOUGH ALOFT TO KEEP A CAP ON ANY
CONVECTION...WE WILL GO WITH A SLIGHT CHC FOR A SHOWER OR
THUNDERSTORM ON THURSDAY AFTN IN CASE ANYTHING IS ABLE TO DEVELOP.
FRIDAY LOOKS EVEN MORE CAPPED...SO WE WILL KEEP THE FORECAST
COMPLETELY DRY FOR FRIDAY WITH A MOSTLY SUNNY TO PARTLY SUNNY SKY.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
HEAT CONTINUES INTO THE FIRST PART OF THE WEEKEND WITH HIGHS
SATURDAY WELL IN THE 80S TO NEAR 90. COLD FRONT AND AMPLIFYING
NORTHERN STREAM UPPER ENERGY APPROACH SUNDAY...TRACKING THROUGH OUR
REGION THE BEGINNING OF THE WEEK...WITH EXACT TIMING TO BE
DETERMINED. SINCE THE EXACT TIMING IS UNKNOWN...INCREASING CHANCES
FOR SHOWERS AND THUNDERSTORMS SUNDAY AND SUNDAY NIGHT...BUILDING
INTO THE MID HUDSON VALLEY AND WESTERN NEW ENGLAND LATER SUNDAY
NIGHT AND MONDAY. DRYING AND COOLING EXPECTED ONCE THE FRONT
EXITS...MONDAY NIGHT AND TUESDAY.
SOME STRONG THUNDERSTORMS ARE POSSIBLE SUNDAY AFTERNOON THROUGH
MONDAY AFTERNOON..DEPENDING ON THE EXACT TIMING OF THE FRONT. THERE
IS A DECENT CONSENSUS FOR A NOTICEABLE COOL DOWN AFTER THE FRONTAL
PASSAGE. HIGHS SUNDAY IN THE UPPER 70S TO MID 80S...COOLING TO HIGHS
IN THE UPPER 60S TO MID 70S MONDAY AND MID 60S TO LOWER 70S TUESDAY.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
ANOTHER AREA OF SHOWERS ASSOCIATED WITH AN OLD WEAKENING CONVECTIVE
COMPLEX SHOULD TRACK THROUGH THE REGION THROUGH ABOUT 16Z...REDUCING
CEILINGS AND VISIBILITIES TO PERIODS OF MVFR AND IFR. IFR
CONDITIONS SHOULD DOMINATE AT KPOU AND KPSF WITH MVFR AT KALB AND
KGFL...BUT ALL SITES SHOULD HAVE PERIODS OF MVFR AND IFR.
ONCE THIS AREA OF SHOWERS EXITS AROUND 16Z...CEILINGS AND
VISIBILITIES SHOULD BE MAINLY VFR...THROUGH THE AFTERNOON AND IN TO
THE EVENING AS A WARM FRONT TRACKS THROUGH THE REGION. HOWEVER...
THERE ARE INDICATIONS THAT SOME ORGANIZED THUNDERSTORM ACTIVITY
COULD TRACK THROUGH THE REGION DURING THE LATE AFTERNOON. KEEPING
THE PROB30 INDICATIONS FOR THUNDERSTORMS BECAUSE THERE ARE ABOVE
NORMAL CHANCES FOR THUNDERSTORMS...ALTHOUGH SCATTERED...STILL ABOVE
NORMAL CHANCES. INDICATING MVFR CEILINGS AND VISIBILITIES IN
THUNDERSTORMS FOR NOW...BUT THERE COULD BE IFR FOR BRIEF PERIODS IN
ANY THUNDERSTORMS.
THE ORGANIZED THUNDERSTORM ACTIVITY COULD MOVE OUT DURING THE EARLY
EVENING...SO JUST INDICATING VCSH AFTER 00Z...WITH VFR CONDITIONS AS
THE WARM FRONT SHOULD BE EXITING AND THE WARM SECTOR EXPANDS OVER
THE REGION.
VARIABLE MAINLY SOUTHEAST TO SOUTHWEST WINDS AT LESS THAN 10 KT
THROUGH THE EARLY MORNING...BECOMING SOUTH TO SOUTHWEST AROUND 10 KT
AFTER 16Z...THEN TRENDING MORE SOUTHWEST AT LESS THAN 10 KT BY THIS
EVENING. A STEADY LIGHT WIND THIS EVENING MAY PREVENT ANY FOG FROM
FORMING AFTER ANY THUNDERSTORM ACTIVITY EXITS...BUT TOO EARLY TO
TELL WHEN STORMS WILL EXIT AND HOW MUCH WIND THERE WILL BE ONCE WE
BREAK INTO THE WARM SECTOR.
OUTLOOK...
THU-SUN...VFR/MVFR. CHC PM -TSRA EACH DAY. LATE NIGHT AND/OR
EARLY MORNING MVFR/IFR ASSOC WITH FOG POSSIBLE.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS OVER THE NEXT SEVERAL DAYS. A WETTING
RAINFALL OCCURRED IN MOST AREAS EARLY THIS MORNING AND ADDITIONAL
SHOWERS AND THUNDERSTORMS ARE POSSIBLE TODAY INTO THIS EVENING.
RH VALUES WILL ONLY DROP TO 55 TO 70 PERCENT TODAY. S-SW WINDS AT
5-15 MPH ARE EXPECTED TODAY.
W-SW WINDS WILL BE AROUND 5-10 MPH TONIGHT WITH RH VALUES RECOVERING TO
NEAR 100 PERCENT. AN ISOLATED SHOWER OR THUNDERSTORM IS POSSIBLE
TOMORROW WITH RH VALUES DROPPING 40 TO 55 PERCENT TOMORROW AFTERNOON.
&&
.HYDROLOGY...
NO WIDESPREAD HYDROLOGIC CONCERNS OVER THE NEXT FIVE DAYS ACROSS
THE HSA.
SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE REGION TODAY. PWAT
VALUES WILL BE ABOVE NORMAL...WITH VALUES UP TO 1.75 INCHES...SO
ANY SHOWER OR THUNDERSTORM IS CAPABLE OF PRODUCING TORRENTIAL
DOWNPOURS. ALTHOUGH WIDESPREAD RIVER FLOODING IS NOT
EXPECTED...SMALL STREAM...POOR DRAINAGE...OR URBAN FLOODING WILL
BE POSSIBLE DEPENDING ON THE EXACT TRACK OF SHOWERS AND
THUNDERSTORMS...ESPECIALLY IF SEVERAL THUNDERSTORMS TRACK OVER THE
SAME LOCATION. 3 HR FFG FROM THE NERFC IS AROUND 2-3 INCHES.
ISOLATED SHOWERS OR THUNDERSTORMS ARE POSSIBLE ON THURSDAY
AFTERNOON. OTHERWISE...IT WILL BE FAIRLY DRY THROUGH THE END OF
THE WORK WEEK. ADDITIONAL SHOWERS OR THUNDERSTORMS ARE POSSIBLE
OVER THE WEEKEND.
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...FRUGIS
NEAR TERM...FRUGIS
SHORT TERM...FRUGIS
LONG TERM...NAS
AVIATION...NAS
FIRE WEATHER...FRUGIS
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
627 AM EDT WED MAY 29 2013
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A WARM FRONT
WILL MOVE THROUGH THE REGION THIS MORNING...ESPECIALLY FOR AREAS TO
THE NORTH OF INTERSTATE 90. AS AN UPPER LEVEL DISTURBANCE MOVES
CLOSE TO THE REGION...SOME STRONG THUNDERSTORMS ARE POSSIBLE THIS
AFTERNOON THROUGH THIS EVENING. MUCH WARMER TEMPERATURES AND MUGGY
CONDITIONS ARE EXPECTED FOR THE REMAINDER OF THE WEEK...WITH SOME
ADDITIONAL THUNDERSTORMS POSSIBLE OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
...SEVERE THUNDERSTORMS POSSIBLE THIS AFTERNOON INTO THIS
EVENING...
AS OF 627 AM EDT...A WARM FRONT WAS SITUATED JUST SOUTH OF THE
REGION ACROSS THE CENTRAL PA AND NJ. AHEAD OF THIS WARM
FRONT...ISENTROPIC LIFT/WARM AIR ADVECTION IS ALLOWING FOR BANDS
OF SHOWERS AND ISOLD THUNDERSTORMS ACROSS WESTERN AND CENTRAL NEW
YORK. OVER THE NEXT FEW HOURS...THESE SHOWERS AND EMBEDDED RUMBLES
OF THUNDER WILL MOVE ACROSS OUR AREA...MAINLY THE CENTRAL AND
NORTHERN ZONES. RAINFALL WILL BE LIGHT TO MODERATE IN INTENSITY.
BY THE MID TO LATE MORNING HOURS...THE WARM FRONT WILL BE LIFTING
NORTH ACROSS OUR NORTHERN ZONES. THERE STILL MAY BE SOME SHOWERS
WITH THE FRONT ACROSS OUR NORTHERN AREAS...OTHERWISE...THERE WILL
BE A LULL IN THE ACTIVITY ACROSS MUCH OF THE REMAINDER OF THE
AREA. SOME BREAKS OF SUN MAY START TO DEVELOP...ESP FOR VALLEY
AREAS FROM THE CAPITAL REGION ON SOUTH. THE CANADIAN CLOUD MODEL
SHOWS SOME BREAKS STARTING TO DEVELOP BY AROUND 16Z FOR THE HUDSON
VALLEY REGION. WITH A LIGHT S-SW WIND IN PLACE...DEWPOINTS WILL
CONTINUE TO RISE INTO THE LOWER TO MID 60S F.
BY AFTERNOON...A SHORTWAVE TROUGH WILL BE MOVING ACROSS THE TOP OF
DEVELOPING RIDGE ACROSS THE EASTERN CONUS...MOVING FROM THE GREAT
LAKES AND LOWER ONTARIO INTO UPSTATE NY. THIS SHORTWAVE...AIDED BY
A STRONG 30-40 KTS LOW LEVEL JET AT 850 HPA WILL HELP FIRE
CONVECTION IN THE WARM SECTOR.
THE NAM12...LOCAL HIRES WRF AND 3KM HRRR ALL SHOW
CONVECTION DEVELOPING ACROSS WESTERN AND CENTRAL NY DURING THE
EARLY AFTN. THIS ACTIVITY WILL SPREAD INTO OUR AREA FOR THE MID
AFTN THROUGH THE EVENING HOURS.
THERE ARE SEVERAL FACTORS WHICH POINT TO THE POTENTIAL FOR SEVERE
THUNDERSTORMS. BECAUSE OF THE STRENGTH OF THE LLJ...0-6 KM BULK SHEAR
WITH BE AROUND 30-40 KTS. 0-3 KM HELICITY VALUES ARE EXPECTED TO
BE AROUND 200 M2/S2 AND 0-1 KM HELICITY VALUES ARE ALSO VERY
IMPRESSIVE...WITH 100-200 M2/S2 BY EVENING. WHILE MID LEVEL LAPSE
RATES AREN/T OVERLY STRONG...VALUES OF 6-6.5 DEGREES C/KM WILL BE
SUFFICIENT FOR PRODUCING UPDRAFTS CAPABLE OF SEVERE WIND/HAIL.
WHILE THE MAIN THREAT WILL BE DAMAGING WINDS...THE IMPRESSIVE
HELICITY VALUES AND THE FACT THAT THIS SAME SYSTEM PRODUCED
TORNADOES LAST EVENING JUST UPSTREAM ACROSS LOWER MICHIGAN WOULD
POINT TO THE POTENTIAL FOR AN ISOLATED TORNADO OR TWO. THE
NAM12/GFS/AND ECMWF ALL DID SHOW SIGNIFICANT TORNADO PARAMETERS IN
EXCESS OF 1 AT SOME LOCATION IN OUR AREA...SO THE TORNADIC
POTENTIAL SHOULD NOT BE IGNORED. SPC AGREES WITH THIS ASSESSMENT
AND HAS OUR AREA IN A SLIGHT RISK...WITH A 5% PROBABILITY FOR A
TORNADO WITHIN 25 MI OF ANY PARTICULAR LOCATION.
THE MAIN INHIBITING FACTOR WILL BE HAVING ENOUGH INSTABILITY.
THERE ARE PLENTY OF CLOUDS AROUND...EVEN UPSTREAM IN THE WARM
SECTOR WITH LINGERING DEBRIS CLOUDS. IF ENOUGH INSTABILITY ISN/T
REALIZED...STORMS MAY HAVE A DIFFICULT TIME GROWING VERY
TALL...AND THE SEVERE POTENTIAL WOULD BE MINIMIZED. AT THIS
POINT...ALL MODELS SHOW CAPE VALUES OF 1000-1500 J/KG...BUT THE
POTENTIAL FOR SUFFICIENT SURFACE BASED CAPE WILL HAVE TO BE
MONITORED THROUGH THE MORNING HOURS.
MAX TEMPS WILL RANGE FROM THE MID 70S TO LOW 80S. IF MORE CLEARING
OCCURS...MAX TEMPS COULD WIND UP ON THE WARMER END OF THIS
RANGE...ESP FROM THE CAPITAL REGION ON SOUTH.
WITH THE LOSS OF HEATING...AND WITH THE SHORTWAVE MOVING TO THE
EAST OF THE AREA...THUNDERSTORM POTENTIAL WILL DIMINISH BY LATE
THIS EVENING. IT SHOULD CLEAR OUT...ALTHOUGH THERE WILL BE
POTENTIAL FOR PATCHY FOG IN THOSE AREAS THAT RECEIVE RAINFALL. MIN
TEMPS WILL BE IN THE 50S TO LOW 60S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
WARM AND MUGGY WEATHER IS EXPECTED FOR THE SHORT TERM PERIOD AS
OUR REGION WILL BE DOMINATED BY A STRONG RIDGE AT 500 HPA CENTERED
OVER THE MID ATLANTIC REGION. 850 HPA TEMPS WILL SURGE TO 16-18
DEGREES C...SO MAX TEMPS WILL REACH THE UPPER 80S TO LOW 90S FOR
BOTH THURSDAY AND FRIDAY. OVERNIGHT LOWS WILL BE WARM AND
STICKY...WITH MAINLY UPPER 50S TO MID 60S AT NIGHT.
WHILE IT SHOULD BE WARM ENOUGH ALOFT TO KEEP A CAP ON ANY
CONVECTION...WE WILL GO WITH A SLIGHT CHC FOR A SHOWER OR
THUNDERSTORM ON THURSDAY AFTN IN CASE ANYTHING IS ABLE TO DEVELOP.
FRIDAY LOOKS EVEN MORE CAPPED...SO WE WILL KEEP THE FORECAST
COMPLETELY DRY FOR FRIDAY WITH A MOSTLY SUNNY TO PARTLY SUNNY SKY.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
HEAT CONTINUES INTO THE FIRST PART OF THE WEEKEND WITH HIGHS
SATURDAY WELL IN THE 80S TO NEAR 90. COLD FRONT AND AMPLIFYING
NORTHERN STREAM UPPER ENERGY APPROACH SUNDAY...TRACKING THROUGH OUR
REGION THE BEGINNING OF THE WEEK...WITH EXACT TIMING TO BE
DETERMINED. SINCE THE EXACT TIMING IS UNKNOWN...INCREASING CHANCES
FOR SHOWERS AND THUNDERSTORMS SUNDAY AND SUNDAY NIGHT...BUILDING
INTO THE MID HUDSON VALLEY AND WESTERN NEW ENGLAND LATER SUNDAY
NIGHT AND MONDAY. DRYING AND COOLING EXPECTED ONCE THE FRONT
EXITS...MONDAY NIGHT AND TUESDAY.
SOME STRONG THUNDERSTORMS ARE POSSIBLE SUNDAY AFTERNOON THROUGH
MONDAY AFTERNOON..DEPENDING ON THE EXACT TIMING OF THE FRONT. THERE
IS A DECENT CONSENSUS FOR A NOTICEABLE COOL DOWN AFTER THE FRONTAL
PASSAGE. HIGHS SUNDAY IN THE UPPER 70S TO MID 80S...COOLING TO HIGHS
IN THE UPPER 60S TO MID 70S MONDAY AND MID 60S TO LOWER 70S TUESDAY.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AN AREA OF SHOWERS ASSOCIATED WITH AN OLD WEAKENING CONVECTIVE
COMPLEX SHOULD TRACK THROUGH THE REGION THROUGH ABOUT 10Z...REDUCING
CEILINGS AND VISIBILITIES TO PERIODS OF MVFR AND IFR. IFR
CONDITIONS SHOULD DOMINATE AT KPOU AND KPSF WITH MVFR AT KALB AND
KGFL...BUT ALL SITES SHOULD HAVE PERIODS OF MVFR AND IFR.
ONCE THIS AREA OF SHOWERS EXITS...SOME LINGERING LOW CLOUDS IN THE
IFR/MVFR RANGE AND VISIBILITIES LIKELY IN THE MVFR RANGE...SHOULD
CONTINUE THROUGH ABOUT 14Z. CEILINGS AND VISIBILITIES SHOULD BE
MAINLY VFR AFTER 14Z...THROUGH THE AFTERNOON AND IN TO THE EVENING
AS A WARM FRONT TRACKS THROUGH THE REGION. HOWEVER...THERE ARE
INDICATIONS THAT SOME ORGANIZED THUNDERSTORM ACTIVITY COULD TRACK
THROUGH THE REGION DURING THE AFTERNOON. KEEPING THE PROB30
INDICATIONS FOR THUNDERSTORMS BECAUSE THERE ARE ABOVE NORMAL CHANCES
FOR THUNDERSTORMS...ALTHOUGH SCATTERED...STILL ABOVE NORMAL CHANCES.
INDICATING MVFR CEILINGS AND VISIBILITIES IN THUNDERSTORMS FOR
NOW...BUT THERE COULD BE IFR FOR BRIEF PERIODS IN ANY THUNDERSTORMS.
THE ORGANIZED THUNDERSTORM ACTIVITY COULD MOVE OUT DURING THE EARLY
EVENING...SO JUST INDICATING VCSH AFTER 23Z...WITH VFR CONDITIONS AS
THE WARM FRONT SHOULD BE EXITING AND THE WARM SECTOR EXPANDS OVER
THE REGION.
VARIABLE MAINLY SOUTHEAST TO SOUTHWEST WINDS AT LESS THAN 10 KT
THROUGH THE EARLY MORNING...BECOMING SOUTH TO SOUTHWEST AROUND 10 KT
AFTER 14Z...THEN TRENDING MORE SOUTHWEST AT LESS THAN 10 KT BY THIS
EVENING. A STEADY LIGHT WIND THIS EVENING MAY PREVENT ANY FOG FROM
FORMING AFTER ANY THUNDERSTORM ACTIVITY EXITS...BUT TOO EARLY TO
TELL WHEN STORMS WILL EXIT AND HOW MUCH WIND THERE WILL BE ONCE WE
BREAK INTO THE WARM SECTOR.
OUTLOOK...
THU-SUN...VFR/MVFR. CHC PM -TSRA EACH DAY. LATE NIGHT AND/OR
EARLY MORNING MVFR/IFR ASSOC WITH FOG POSSIBLE.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS OVER THE NEXT SEVERAL DAYS. A WETTING
RAINFALL OCCURRED IN MOST AREAS EARLY THIS MORNING AND ADDITIONAL
SHOWERS AND THUNDERSTORMS ARE POSSIBLE TODAY INTO THIS EVENING.
RH VALUES WILL ONLY DROP TO 55 TO 70 PERCENT TODAY. S-SW WINDS AT
5-15 MPH ARE EXPECTED TODAY.
W-SW WINDS WILL BE AROUND 5-10 MPH TONIGHT WITH RH VALUES RECOVERING TO
NEAR 100 PERCENT. AN ISOLATED SHOWER OR THUNDERSTORM IS POSSIBLE
TOMORROW WITH RH VALUES DROPPING 40 TO 55 PERCENT TOMORROW AFTERNOON.
&&
.HYDROLOGY...
NO WIDESPREAD HYDROLOGIC CONCERNS OVER THE NEXT FIVE DAYS ACROSS
THE HSA.
SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE REGION TODAY. PWAT
VALUES WILL BE ABOVE NORMAL...WITH VALUES UP TO 1.75 INCHES...SO
ANY SHOWER OR THUNDERSTORM IS CAPABLE OF PRODUCING TORRENTIAL
DOWNPOURS. ALTHOUGH WIDESPREAD RIVER FLOODING IS NOT
EXPECTED...SMALL STREAM...POOR DRAINAGE...OR URBAN FLOODING WILL
BE POSSIBLE DEPENDING ON THE EXACT TRACK OF SHOWERS AND
THUNDERSTORMS...ESPECIALLY IF SEVERAL THUNDERSTORMS TRACK OVER THE
SAME LOCATION. 3 HR FFG FROM THE NERFC IS AROUND 2-3 INCHES.
ISOLATED SHOWERS OR THUNDERSTORMS ARE POSSIBLE ON THURSDAY
AFTERNOON. OTHERWISE...IT WILL BE FAIRLY DRY THROUGH THE END OF
THE WORK WEEK. ADDITIONAL SHOWERS OR THUNDERSTORMS ARE POSSIBLE
OVER THE WEEKEND.
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...FRUGIS
NEAR TERM...FRUGIS
SHORT TERM...FRUGIS
LONG TERM...NAS
AVIATION...NAS
FIRE WEATHER...FRUGIS
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
418 AM EDT WED MAY 29 2013
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A WARM FRONT
WILL MOVE THROUGH THE REGION THIS MORNING...ESPECIALLY FOR AREAS TO
THE NORTH OF INTERSTATE 90. AS AN UPPER LEVEL DISTURBANCE MOVES
CLOSE TO THE REGION...SOME STRONG THUNDERSTORMS ARE POSSIBLE THIS
AFTERNOON THROUGH THIS EVENING. MUCH WARMER TEMPERATURES AND MUGGY
CONDITIONS ARE EXPECTED FOR THE REMAINDER OF THE WEEK...WITH SOME
ADDITIONAL THUNDERSTORMS POSSIBLE OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
...SEVERE THUNDERSTORMS POSSIBLE THIS AFTERNOON INTO THIS EVENING...
AS OF 418 AM EDT...A WARM FRONT WAS SITUATED JUST SOUTH OF THE
REGION ACROSS THE CENTRAL PA AND NJ. A BAND OF RAIN SHOWERS AND
ISOLD THUNDERSTORMS HAS MOVED ACROSS THE REGION...AND ADDITIONAL
SHOWERS AND EMBEDDED RUMBLES OF THUNDER ASSOCIATED WITH THE
BOUNDARY ITSELF WERE TO OUR WEST AND SOUTHWEST. DURING THE NEXT
SEVERAL HOURS...THESE SHOWERS AND EMBEDDED THUNDERSTORMS WILL MOVE
ACROSS OUR REGION...AS THE WARM FRONT SLOWLY LIFTS NORTHWARD.
SHOWERS WILL GENERALLY BE LIGHT TO MODERATE IN INTENSITY.
BY THE MID MORNING HOURS...THE WARM FRONT WILL BE LIFTING NORTH
ACROSS OUR NORTHERN ZONES. THERE STILL MAY BE SOME SHOWERS WITH
THE FRONT ACROSS OUR NORTHERN AREAS...OTHERWISE...THERE WILL BE A
LULL IN THE ACTIVITY ACROSS OUR AREA. SOME BREAKS OF SUN MAY START
TO DEVELOP...ESP FOR VALLEY AREAS FROM THE CAPITAL REGION ON
SOUTH. WITH A LIGHT S-SW WIND IN PLACE...DEWPOINTS WILL CONTINUE
TO RISE INTO THE LOWER TO MID 60S F.
BY AFTERNOON...A SHORTWAVE TROUGH WILL BE MOVING ACROSS THE TOP OF
DEVELOPING RIDGE ACROSS THE EASTERN CONUS...MOVING FROM THE GREAT
LAKES AND LOWER ONTARIO INTO UPSTATE NY. THIS SHORTWAVE...AIDED BY
A STRONG 30-40 KTS LOW LEVEL JET AT 850 HPA WILL HELP FIRE
CONVECTION IN THE WARM SECTOR.
THE NAM12...LOCAL HIRES WRF AND 3KM HRRR ALL SHOW
CONVECTION DEVELOPING ACROSS WESTERN AND CENTRAL NY DURING THE
EARLY AFTN. THIS ACTIVITY WILL SPREAD INTO OUR AREA FOR THE MID
THROUGH THE EVENING HOURS.
THERE ARE SEVERAL FACTORS WHICH POINT TO THE POTENTIAL FOR SEVERE
THUNDERSTORMS. BECAUSE OF THE STRENGTH OF THE LLJ...0-6 KM BULK SHEAR
WITH BE AROUND 30-40 KTS. 0-3 KM HELICITY VALUES ARE EXPECTED TO
BE AROUND 200 M2/S2 AND 0-1 KM HELICITY VALUES ARE ALSO VERY
IMPRESSIVE...WITH 100-200 M2/S2 BY EVENING. WHILE MID LEVEL LAPSE
RATES AREN/T OVERLY STRONG...VALUES OF 6-6.5 DEGREES C/KM WILL BE
SUFFICIENT FOR PRODUCING UPDRAFTS CAPABLE OF SEVERE WIND/HAIL.
WHILE THE MAIN THREAT WILL BE DAMAGING WINDS...THE IMPRESSIVE
HELICITY VALUES AND THE FACT THAT THIS SAME SYSTEM PRODUCED
TORNADOES LAST EVENING JUST UPSTREAM ACROSS LOWER MICHIGAN WOULD
POINT TO THE POTENTIAL FOR AN ISOLATED TORNADO OR TWO. THE
NAM12/GFS/AND ECMWF ALL DID SHOW SIGNIFICANT TORNADO PARAMETERS IN
EXCESS OF 1 AT SOME LOCATION IN OUR AREA...SO THE TORNADIC
POTENTIAL SHOULD NOT BE IGNORED. SPC AGREES WITH THIS ASSESSMENT
AND HAS OUR AREA IN A SLIGHT RISK...WITH A 5% PROBABILITY FOR A
TORNADO WITHIN 25 MI OF ANY PARTICULAR LOCATION.
THE MAIN INHIBITING FACTOR WILL BE HAVING ENOUGH INSTABILITY.
THERE ARE PLENTY OF CLOUDS AROUND...EVEN UPSTREAM IN THE WARM
SECTOR WITH LINGERING DEBRIS CLOUDS. IF ENOUGH INSTABILITY ISN/T
REALIZED...STORMS MAY HAVE A DIFFICULT TIME GROWING VERY
TALL...AND THE SEVERE POTENTIAL WOULD BE MINIMIZED. AT THIS
POINT...ALL MODELS SHOW CAPE VALUES OF 1000-1500 J/KG...BUT THE
POTENTIAL FOR SUFFICIENT SURFACE BASED CAPE WILL HAVE TO BE
MONITORED THROUGH THE MORNING HOURS.
MAX TEMPS WILL RANGE FROM THE MID 70S TO LOW 80S. IF MORE CLEARING
OCCURS...MAX TEMPS COULD WIND UP ON THE WARMER END OF THIS
RANGE...ESP FROM THE CAPITAL REGION ON SOUTH.
WITH THE LOSS OF HEATING...AND WITH THE SHORTWAVE MOVING TO THE
EAST OF THE AREA...THUNDERSTORM POTENTIAL WILL DIMINISH BY LATE
THIS EVENING. IT SHOULD CLEAR OUT...ALTHOUGH THERE WILL BE
POTENTIAL FOR PATCHY FOG IN THOSE AREAS THAT RECEIVE RAINFALL. MIN
TEMPS WILL BE IN THE 50S TO LOW 60S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
WARM AND MUGGY WEATHER IS EXPECTED FOR THE SHORT TERM PERIOD AS
OUR REGION WILL BE DOMINATED BY A STRONG RIDGE AT 500 HPA CENTERED
OVER THE MID ATLANTIC REGION. 850 HPA TEMPS WILL SURGE TO 16-18
DEGREES C...SO MAX TEMPS WILL REACH THE UPPER 80S TO LOW 90S FOR
BOTH THURSDAY AND FRIDAY. OVERNIGHT LOWS WILL BE WARM AND
STICKY...WITH MAINLY UPPER 50S TO MID 60S AT NIGHT.
WHILE IT SHOULD BE WARM ENOUGH ALOFT TO KEEP A CAP ON ANY
CONVECTION...WE WILL GO WITH A SLIGHT CHC FOR A SHOWER OR
THUNDERSTORM ON THURSDAY AFTN IN CASE ANYTHING IS ABLE TO DEVELOP.
FRIDAY LOOKS EVEN MORE CAPPED...SO WE WILL KEEP THE FORECAST
COMPLETELY DRY FOR FRIDAY WITH A MOSTLY SUNNY TO PARTLY SUNNY SKY.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
HEAT CONTINUES INTO THE FIRST PART OF THE WEEKEND WITH HIGHS
SATURDAY WELL IN THE 80S TO NEAR 90. COLD FRONT AND AMPLIFYING
NORTHERN STREAM UPPER ENERGY APPROACH SUNDAY...TRACKING THROUGH OUR
REGION THE BEGINNING OF THE WEEK...WITH EXACT TIMING TO BE
DETERMINED. SINCE THE EXACT TIMING IS UNKNOWN...INCREASING CHANCES
FOR SHOWERS AND THUNDERSTORMS SUNDAY AND SUNDAY NIGHT...BUILDING
INTO THE MID HUDSON VALLEY AND WESTERN NEW ENGLAND LATER SUNDAY
NIGHT AND MONDAY. DRYING AND COOLING EXPECTED ONCE THE FRONT
EXITS...MONDAY NIGHT AND TUESDAY.
SOME STRONG THUNDERSTORMS ARE POSSIBLE SUNDAY AFTERNOON THROUGH
MONDAY AFTERNOON..DEPENDING ON THE EXACT TIMING OF THE FRONT. THERE
IS A DECENT CONSENSUS FOR A NOTICEABLE COOL DOWN AFTER THE FRONTAL
PASSAGE. HIGHS SUNDAY IN THE UPPER 70S TO MID 80S...COOLING TO HIGHS
IN THE UPPER 60S TO MID 70S MONDAY AND MID 60S TO LOWER 70S TUESDAY.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
AN AREA OF SHOWERS ASSOCIATED WITH AN OLD WEAKENING CONVECTIVE
COMPLEX SHOULD TRACK THROUGH THE REGION THROUGH ABOUT 10Z...REDUCING
CEILINGS AND VISIBILITIES TO PERIODS OF MVFR AND IFR. IFR
CONDITIONS SHOULD DOMINATE AT KPOU AND KPSF WITH MVFR AT KALB AND
KGFL...BUT ALL SITES SHOULD HAVE PERIODS OF MVFR AND IFR.
ONCE THIS AREA OF SHOWERS EXITS...SOME LINGERING LOW CLOUDS IN THE
IFR/MVFR RANGE AND VISIBILITIES LIKELY IN THE MVFR RANGE...SHOULD
CONTINUE THROUGH ABOUT 14Z. CEILINGS AND VISIBILITIES SHOULD BE
MAINLY VFR AFTER 14Z...THROUGH THE AFTERNOON AND IN TO THE EVENING
AS A WARM FRONT TRACKS THROUGH THE REGION. HOWEVER...THERE ARE
INDICATIONS THAT SOME ORGANIZED THUNDERSTORM ACTIVITY COULD TRACK
THROUGH THE REGION DURING THE AFTERNOON. KEEPING THE PROB30
INDICATIONS FOR THUNDERSTORMS BECAUSE THERE ARE ABOVE NORMAL CHANCES
FOR THUNDERSTORMS...ALTHOUGH SCATTERED...STILL ABOVE NORMAL CHANCES.
INDICATING MVFR CEILINGS AND VISIBILITIES IN THUNDERSTORMS FOR
NOW...BUT THERE COULD BE IFR FOR BRIEF PERIODS IN ANY THUNDERSTORMS.
THE ORGANIZED THUNDERSTORM ACTIVITY COULD MOVE OUT DURING THE EARLY
EVENING...SO JUST INDICATING VCSH AFTER 23Z...WITH VFR CONDITIONS AS
THE WARM FRONT SHOULD BE EXITING AND THE WARM SECTOR EXPANDS OVER
THE REGION.
VARIABLE MAINLY SOUTHEAST TO SOUTHWEST WINDS AT LESS THAN 10 KT
THROUGH THE EARLY MORNING...BECOMING SOUTH TO SOUTHWEST AROUND 10 KT
AFTER 14Z...THEN TRENDING MORE SOUTHWEST AT LESS THAN 10 KT BY THIS
EVENING. A STEADY LIGHT WIND THIS EVENING MAY PREVENT ANY FOG FROM
FORMING AFTER ANY THUNDERSTORM ACTIVITY EXITS...BUT TOO EARLY TO
TELL WHEN STORMS WILL EXIT AND HOW MUCH WIND THERE WILL BE ONCE WE
BREAK INTO THE WARM SECTOR.
OUTLOOK...
THU-SUN...VFR/MVFR. CHC PM -TSRA EACH DAY. LATE NIGHT AND/OR
EARLY MORNING MVFR/IFR ASSOC WITH FOG POSSIBLE.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS OVER THE NEXT SEVERAL DAYS. A WETTING
RAINFALL OCCURRED IN MOST AREAS EARLY THIS MORNING AND ADDITIONAL
SHOWERS AND THUNDERSTORMS ARE POSSIBLE TODAY INTO THIS EVENING.
RH VALUES WILL ONLY DROP TO 55 TO 70 PERCENT TODAY. S-SW WINDS AT
5-15 MPH ARE EXPECTED TODAY.
W-SW WINDS WILL BE AROUND 5-10 MPH TONIGHT WITH RH VALUES RECOVERING TO
NEAR 100 PERCENT. AN ISOLATED SHOWER OR THUNDERSTORM IS POSSIBLE
TOMORROW WITH RH VALUES DROPPING 40 TO 55 PERCENT TOMORROW AFTERNOON.
&&
.HYDROLOGY...
NO WIDESPREAD HYDROLOGIC CONCERNS OVER THE NEXT FIVE DAYS ACROSS
THE HSA.
SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE REGION TODAY. PWAT
VALUES WILL BE ABOVE NORMAL...WITH VALUES UP TO 1.75 INCHES...SO
ANY SHOWER OR THUNDERSTORM IS CAPABLE OF PRODUCING TORRENTIAL
DOWNPOURS. ALTHOUGH WIDESPREAD RIVER FLOODING IS NOT
EXPECTED...SMALL STREAM...POOR DRAINAGE...OR URBAN FLOODING WILL
BE POSSIBLE DEPENDING ON THE EXACT TRACK OF SHOWERS AND
THUNDERSTORMS...ESPECIALLY IF SEVERAL THUNDERSTORMS TRACK OVER THE
SAME LOCATION. 3 HR FFG FROM THE NERFC IS AROUND 2-3 INCHES.
ISOLATED SHOWERS OR THUNDERSTORMS ARE POSSIBLE ON THURSDAY
AFTERNOON. OTHERWISE...IT WILL BE FAIRLY DRY THROUGH THE END OF
THE WORK WEEK. ADDITIONAL SHOWERS OR THUNDERSTORMS ARE POSSIBLE
OVER THE WEEKEND.
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...FRUGIS
NEAR TERM...FRUGIS
SHORT TERM...FRUGIS
LONG TERM...NAS
AVIATION...NAS
FIRE WEATHER...FRUGIS
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
138 AM EDT WED MAY 29 2013
.SYNOPSIS...
RAIN AND SOME THUNDERSTORMS ASSOCIATED WITH A WARM FRONT
WILL MOVE THROUGH THE REGION FROM THE SOUTHWEST OVERNIGHT INTO
WEDNESDAY MORNING. AS AN UPPER LEVEL DISTURBANCE MOVES CLOSE TO THE
REGION...SOME STRONG THUNDERSTORMS ARE POSSIBLE ON WEDNESDAY
AFTERNOON INTO WEDNESDAY EVENING. MUCH WARMER TEMPERATURES AND
MUGGY CONDITIONS ARE EXPECTED FOR THE REMAINDER OF THE WEEK...WITH
SOME ADDITIONAL THUNDERSTORMS POSSIBLE OVER THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 138 AM EDT...A BAND OF RAIN SHOWERS AND EMBEDDED
THUNDERSTORMS ASSOCIATED WITH A WARM FRONT IS MOVING ACROSS
CENTRAL AND SOUTHERN PORTIONS OF THE CWA EARLY THIS MORNING.
RAINFALL IS GENERALLY LIGHT TO MODERATE...WITH ONE HOUR
ACCUMULATION ESTIMATES OF LESS THAN A QUARTER OF AN INCH PER HOUR.
OUR 4KM HIRES WRF AND THE 3KM HRRR ALL SHOW THIS ACTIVITY SLIDING
WEST TO EAST OVER THE NEXT FEW HOURS. BY LATE TONIGHT...THE BEST
THREAT FOR RAIN AND EMBEDDED THUNDER WILL BE ACROSS NORTHERN PARTS
OF THE CWA...AS THE WARM FRONT GRADUALLY MAKES NORTHWARD PROGRESS.
THUNDER WILL BE FAIRLY ISOLD TO SCATTERED OVERNIGHT...AS THERE IS
NO SURFACE INSTABILITY IN PLACE...AND ANY INSTABILITY WILL BE
ELEVATED AND FAIRLY LIMITED. WHILE THERE WERE SOME SEVERE TSTMS
ACROSS WESTERN NY/NORTHWEST PA...THERE WILL BE NO THREAT FOR
SEVERE STORMS WILL ANY OF THESE EMBEDDED THUNDERSTORMS OVERNIGHT.
THIS WILL BE DIFFERENT DURING THE WEDNESDAY /SEE THE SHORT TERM
SECTION FOR DETAILS ON THE SEVERE POTENTIAL FOR THE AFTN TO EVE
HOURS/.
WITH THE CLOUDS...PRECIP...AND LIGHT SOUTHERLY WINDS...TEMPS
OVERNIGHT WILL GENERALLY HOLD STEADY IN THE MID 50S.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
OUR REGION WILL BE SITUATED ON THE NORTHERN FRINGE OF A BUILDING
RIDGE ACROSS THE EASTERN CONUS ON WEDNESDAY. AT THE SFC...WE WILL
BE POKING INTO THE WARM SECTOR AS THE WARM FRONT WILL BE LIFTING
ACROSS THE REGION. THE WARM FRONT WILL BE MOVING ACROSS THE THE
REGION WEDNESDAY MORNING...SO HAVE CONTINUED LIKELY POPS FOR A FEW
HOURS...ESPECIALLY ACROSS THE NORTH.
AFTERWARD...SOME BREAKS OF SUN WILL OCCUR...ESP FOR VALLEY AREAS.
A SHORTWAVE WILL BE MOVING WITHIN THE STRONG W-SW FLOW ALOFT
ACROSS ONTARIO TOWARDS NORTHERN NY FOR THE AFTN HOURS. THE AMOUNT OF
SUNSHINE THAT OCCURS WILL BE CRITICAL...AS THIS WILL DETERMINE JUST
HOW MUCH INSTABILITY CAN BUILD UP. MODELS SHOW SHEAR VALUES BETWEEN
30 AND 40 KTS...AND CAPE VALUES OF 500-1500 J/KG. SPC CONTINUES TO
HAS PLACE OUR REGION IN A SLIGHT RISK FOR SEVERE WX AND HAS EVEN
EXPANDED THE SIZE OF THE AREA...AND IT APPEARS THAT WE WILL HAVE
SEVERAL INGREDIENTS IN PLACE FOR SOME GUSTY TSTMS.
HAVE 40 TO 50 PERCENT FOR SHOWERS/TSTMS. HAVE TRENDED MAX TEMPS
TOWARDS THE WARMER MAV GUIDANCE WITH HIGHS IN THE MID 70S TO MID
80S.
THE CHANCE FOR TSTMS WILL BE DECREASING TO ONLY SLIGHT CHANCE LATE
WEDNESDAY NIGHT AS THE SHORTWAVE MOVES EASTWARD...AND SFC HEATING
DIMINISHES. LOWS WILL BE IN THE MID 50S TO MID 60S.
850 HPA WILL RISE TO 16-18 DEGREES C ON THURSDAY...WITH THE 500 HPA
RIDGE CENTERED OVER THE DELMARVA. IT WILL BE WARM AND MUGGY...WITH
MAX TEMPS IN THE UPPER TO LOWER 90S. THE SFC BOUNDARY SHOULD BE
LOCATED FAR ENOUGH TO NORTH OF THE AREA FOR LITTLE LARGE SCALE
FORCING TO BE IN PLACE ACROSS OUR AREA...SO WIDESPREAD CONVECTION IS
NOT ANTICIPATED. MOST AREAS WILL LIKELY BE CAPPED AS WELL. HAVE
ONLY FORECAST A SLIGHT CHANCE OF TSTMS DURING THE AFTERNOON.
WITH THE RIDGE AND STRONG CAP STILL OVER THE REGION THURSDAY
NIGHT...HAVE NOT FORECAST ANY PCPN. IT WILL REMAIN WARM AND MUGGY
WITH LOWS IN THE UPPER 50S TO MID 60S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THE LONG TERM WILL BE CHARACTERIZED BY INCREASING TEMPERATURES AND
HUMIDITY ALONG WITH CHANCES FOR SHOWERS AND THUNDERSTORMS AS A COLD
FRONT CROSSES THE REGION DURING THE WEEKEND.
LONG RANGE GUIDANCE CONTINUES TO BE IN EXCELLENT AGREEMENT HANDLING
MUCH OF THE LONG TERM PERIOD WITH BOTH THE 12Z GFS/ECMWF AND VARIOUS
ENSEMBLE MEMBERS DEPICTING A LARGE WARM CORE HIGH ACROSS THE EASTERN
THIRD OF THE NATION. THIS SYNOPTIC SETUP WILL BE PREVALENT THROUGH
MUCH OF THE FIRST WEEKEND OF JUNE...ALLOWING FOR A PERSISTENT
SOUTHWESTERLY RETURN FLOW TRANSPORT OF WARM AND HUMID AIR ACROSS THE
REGION AS MANY LOCATIONS ACROSS THE FORECAST AREA LOOK TO REACH 90
DEGREES FOR THE FIRST TIME IN 2013 ON FRIDAY.
A PATTERN SHIFT WILL START TO SLOWLY TAKE PLACE BEGINNING
SATURDAY...AS AN UPPER-LEVEL TROUGH AND ASSOCIATED SURFACE LOW
PRESSURE SYSTEM AND COLD FRONT APPROACH FROM THE UPPER MIDWEST. WITH
THE LARGE ANTICYCLONIC BERMUDA CIRCULATION FIRMLY ENTRENCHED ACROSS
THE EASTERN CONUS AND A POSITIVE-TILT ORIENTATION TO THE UPSTREAM
TROUGH...THERE REMAINS SOME UNCERTAINTY REGARDING THE EXACT TIMING
OF THE COLD FRONTAL PASSAGE ACROSS THE FORECAST AREA.
REGARDLESS...HAVE INTRODUCED SLIGHT CHANCE POPS BEGINNING EARLY
SATURDAY AS SOME WEAK NORTHERN STREAM ENERGY SLIDES OFF TO THE
NORTH. POPS INCREASE SATURDAY NIGHT TO CHANCE...WITH LIKELY POPS FOR
MUCH OF THE FORECAST AREA SUNDAY.
GIVEN ANTECEDENT WARM AND HUMID CONDITIONS AHEAD OF THE COLD FRONT
AND SHOWALTER INDICES BELOW 0C COUPLED WITH INCREASING WIND PROFILES
FROM A 50-70 KNOT UPPER-LEVEL JET...THE POTENTIAL EXISTS FOR
STRONGER STORMS SUNDAY ACCOMPANYING THE COLD FRONT PASSAGE.
THE QUESTION WILL BE JUST HOW MUCH INSTABILITY THERE WILL BE
SUNDAY...BUT THERE CONTINUES TO BE A SIGNAL FOR MORE ROBUST
CONVECTION. WITH 850 HPA MOISTURE TRANSPORT VECTORS INDICATING RAPID
MOISTURE TRANSPORT INTO THE REGION AMIDST PWAT ANOMALIES OF 1-2
STANDARD DEVIATIONS...THE POTENTIAL ALSO EXISTS FOR SOME TORRENTIAL
RAINFALL WITH ANY CONVECTION THAT DEVELOPS.
THE COLD FRONT WILL CROSS THE FORECAST AREA SOMETIME IN THE LATE
SUNDAY-EARLY MONDAY TIMEFRAME...ENDING PRECIPITATION CHANCES ACROSS
MUCH OF THE FORECAST AREA. IT IS DURING THIS TIMEFRAME THAT THE LONG
RANGE GUIDANCE BEGINS TO DIVERGE WITH THE 12Z GFS CONTINUING TO
INDICATE THE FRONT STALLING SOMEWHERE ALONG THE EASTERN SEABOARD
WITH A WAVE OF LOW PRESSURE DEVELOPING ALONG IT DUE TO THE
AMPLIFICATION OF THE UPPER TROUGH...WHILE THE 12Z ECMWF MAINTAINS A
PROGRESSIVE POSITIVE-TILT ORIENTATION TO THE UPPER TROUGH. GIVEN THE
SOUTHWARD DISPLACEMENT OF THE BERMUDA HIGH...WILL SIDE WITH THE 12Z
ECMWF SOLUTION FAVORING DECREASING PRECIPITATION CHANCES VERSUS A
POTENTIAL HEAVY RAIN EVENT ACCORDING TO THE GFS FOR EARLY NEXT WEEK.
WITH HUMID CONDITIONS IN PLACE...THE FIRST WEEKEND OF JUNE WILL FEEL
A LOT LIKE THE DOG DAYS OF SUMMER AS HIGH TEMPERATURES FRIDAY AND
SATURDAY REACH WELL INTO THE 80S...WITH POCKETS OF NEAR 90 AND
POTENTIALLY EVEN LOW 90S IN THE MID HUDSON VALLEY. THE RECORD HIGH
FOR ALBANY ON FRIDAY IS 92 DEGREES SET IN 1937 AND 94 DEGREES ON
SATURDAY SET IN 1918. TEMPERATURES WILL REMAIN IN THE 80S FOR SUNDAY
AHEAD OF THE COLD FRONT. THE PASSAGE OF THE COLD FRONT WILL USHER IN
CANADIAN HIGH PRESSURE AND COOLER TEMPERATURES...WITH HIGHS IN THE
UPPER 60S/LOWER 70S FOR THE START OF NEXT WEEK. LOW TEMPERATURES
WILL GENERALLY BE IN THE UPPER 50S TO MID 60S BEFORE COOLING INTO
THE UPPER 40S-MID 50S FOR THE START OF NEXT WEEK.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AN AREA OF SHOWERS ASSOCIATED WITH AN OLD WEAKENING CONVECTIVE
COMPLEX SHOULD TRACK THROUGH THE REGION THROUGH ABOUT 10Z...REDUCING
CEILINGS AND VISIBILITIES TO PERIODS OF MVFR AND IFR. IFR
CONDITIONS SHOULD DOMINATE AT KPOU AND KPSF WITH MVFR AT KALB AND
KGFL...BUT ALL SITES SHOULD HAVE PERIODS OF MVFR AND IFR.
ONCE THIS AREA OF SHOWERS EXITS...SOME LINGERING LOW CLOUDS IN THE
IFR/MVFR RANGE AND VISIBILITIES LIKELY IN THE MVFR RANGE...SHOULD
CONTINUE THROUGH ABOUT 14Z. CEILINGS AND VISIBILITIES SHOULD BE
MAINLY VFR AFTER 14Z...THROUGH THE AFTERNOON AND IN TO THE EVENING
AS A WARM FRONT TRACKS THROUGH THE REGION. HOWEVER...THERE ARE
INDICATIONS THAT SOME ORGANIZED THUNDERSTORM ACTIVITY COULD TRACK
THROUGH THE REGION DURING THE AFTERNOON. KEEPING THE PROB30
INDICATIONS FOR THUNDERSTORMS BECAUSE THERE ARE ABOVE NORMAL CHANCES
FOR THUNDERSTORMS...ALTHOUGH SCATTERED...STILL ABOVE NORMAL CHANCES.
INDICATING MVFR CEILINGS AND VISIBILITIES IN THUNDERSTORMS FOR
NOW...BUT THERE COULD BE IFR FOR BRIEF PERIODS IN ANY THUNDERSTORMS.
THE ORGANIZED THUNDERSTORM ACTIVITY COULD MOVE OUT DURING THE EARLY
EVENING...SO JUST INDICATING VCSH AFTER 23Z...WITH VFR CONDITIONS AS
THE WARM FRONT SHOULD BE EXITING AND THE WARM SECTOR EXPANDS OVER
THE REGION.
VARIABLE MAINLY SOUTHEAST TO SOUTHWEST WINDS AT LESS THAN 10 KT
THROUGH THE EARLY MORNING...BECOMING SOUTH TO SOUTHWEST AROUND 10 KT
AFTER 14Z...THEN TRENDING MORE SOUTHWEST AT LESS THAN 10 KT BY THIS
EVENING. A STEADY LIGHT WIND THIS EVENING MAY PREVENT ANY FOG FROM
FORMING AFTER ANY THUNDERSTORM ACTIVITY EXITS...BUT TOO EARLY TO
TELL WHEN STORMS WILL EXIT AND HOW MUCH WIND THERE WILL BE ONCE WE
BREAK INTO THE WARM SECTOR.
OUTLOOK...
THU-SUN...VFR/MVFR. CHC PM -TSRA EACH DAY. LATE NIGHT AND/OR
EARLY MORNING MVFR/IFR ASSOC WITH FOG POSSIBLE.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS OVER THE NEXT SEVERAL DAYS.
S-SE WINDS WILL BE AROUND 5 TO 15 MPH TONIGHT WITH RH VALUES
RECOVERING TO NEAR 100 PERCENT. SHOWERS AND THUNDERSTORMS ARE LIKELY
TONIGHT AND WEDNESDAY. ALSO ON WEDNESDAY...RH VALUES WILL ONLY DROP
TO BETWEEN 50 AND 65 PERCENT WITH S-SW WINDS AT 10 TO 20 MPH WITH
GUSTS OVER 25 MPH.
&&
.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED ACROSS THE HSA FOR THE
NEXT 5 DAYS.
RIVER FLOWS HAVE RECEDED THE PAST FEW DAYS AFTER THE HEAVIER RAINS
FROM LAST WEEK INTO THE WEEKEND. AN APPROACHING WARM FRONT WILL
ALLOW FOR SOME SHOWERS AND POSSIBLE THUNDERSTORMS INTO WEDNESDAY
MORNING. ADDITIONAL THUNDERSTORMS ARE POSSIBLE ON WEDNESDAY...WITH
JUST ISOLATED TO WIDELY SCATTERED THUNDERSTORM ACTIVITY ON THURSDAY
THROUGH SATURDAY.
WHILE WIDESPREAD HEAVY RAINFALL IS NOT ANTICIPATED THIS WEEK...ANY
AREAS THAT SEES REPEATED SHOWERS OR THUNDERSTORMS MAY LOCALLY SEE
SOME WITHIN BANK RISES ON RIVERS AND STREAMS. DUE TO THE SCATTERED
NATURE OF THE SHOWERS AND THUNDERSTORMS...QPF AMOUNTS WILL BE
VARIABLE ACROSS THE REGION. THE LATEST WEATHER PREDICTION CENTER
/WPC/ QPF FORECAST CALLS FOR UP TO AN INCH OF RAINFALL ACROSS THE
REGION THROUGH SATURDAY EVENING...ALTHOUGH THIS WILL ULTIMATELY
DEPEND ON THE EXACT TRACK OF ANY SHOWERS OR THUNDERSTORMS.
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...FRUGIS
NEAR TERM...FRUGIS
SHORT TERM...FRUGIS/GJM
LONG TERM...IRL
AVIATION...NAS
FIRE WEATHER...GJM
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
325 PM EDT WED MAY 29 2013
.SYNOPSIS...
HIGH PRESSURE OFF THE EAST COAST WILL CONTINUE TO ESTABLISH ITSELF
OVER THE NEXT FEW DAYS WHILE SLOWLY MOVING OUT TO SEA THROUGH THE
WEEKEND. A LOW PRESSURE SYSTEM WILL TRACK INTO THE GREAT LAKES
REGION AND PUSH A COLD FRONT THROUGH BY EARLY NEXT WEEK. HIGH
PRESSURE WILL FILL BACK IN BEHIND THE DEPARTING FRONT.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
THE GFS INITIALIZATION LOOKED SLIGHTLY BETTER THAN THE WRF-NMMB
OVERALL AND GIVEN HOW THE WRF-NMMB IS NOT VERIFYING WELL WITH ITS
CONVECTIVE FCST THRU 18Z IN OUR CWA. WE WILL LEAN THE GFS`S WAY. THE
HRRR WHICH LOOKED PRETTY GOOD THROUGH THIS MORNING IS NOW VERIFYING
TOO HOT, THE LATEST 12Z SPC WRF IS LOOKING BETTER AND OUR POPS AND
WEATHER THROUGH THIS EARLY EVENING IS CLOSEST TO A WRF-AWWE (WHICH
IS VERIFYING PRETTY GOOD ALSO) AND GFS COMBO.
CONVECTION IS STARTING TO FIRE IN WESTERN NY STATE, OVERALL SLIGHTLY
FARTHER NORTH AND SLOWER THAN WHAT THE OVERNIGHT MODELS WERE
SHOWING. THE 12Z MODELS HAVE ADJUSTED NORTHWARD AND WE LOWERED POPS
FOR THE REST OF THIS AFTERNOON INTO THIS EVENING IN THE SOUTHERN
PART OF OUR CWA. 12Z MODEL FCST BULK SHEAR REMAINS IN NY STATE, SO
GREATEST CHANCE FOR MORE ROBUST STORMS REMAIN ALONG THE FAR NRN PART
OF OUR CWA.
THE GFS DOES SHOW A SHORT WAVE LINGERING FAR NORTH INTO THIS EVENING
AND SOME OF THE MESOSCALE MODELS PROLONG CONVECTIVE CHANCES DEEP
INTO THE EVENING. GIVEN THE TENDENCY TODAY HAS BEEN FOR THEM TO BE
TOO CONVECTIVE, WE COMPROMISED AN ENDING POP TIMING THIS EVENING
BETWEEN THEM AND THE FASTER HRRR AND GFS.
FOG SHOULD NOT BE AS MUCH OF A PROBLEM TONIGHT AS LAST NIGHT, MORE
OF THE PATCHIER VARIETY UNLESS A MORE ORGANIZED CONVECTIVE CLUSTER
GETS DEEPER INTO OUR CWA THAN WE ARE THINKING. MIN TEMPS REMAIN A
BLEND OF CONTINUITY AND LATEST STAT GUIDANCE. THERE SHOULD BE SOME
DEBRIS CLOUDINESS AROUND WHICH ADDS SOME REDUCED CONFIDENCE TO MIN
TEMPERATURE FCSTS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
THE FIRST WIDESPREAD 90 DEGREE DAY IS EXPECTED TO OCCUR TOMORROW
ACROSS A LARGE PART OF OUR CWA. THE AIR MASS AT OR BELOW 850MB IS
FORECAST TO BE 1-2C WARMER THAN TODAY WHICH SHOULD INCREASE THE
NUMBER OF 90 DEGREE READINGS FROM TODAY. OF EQUAL IMPORTANCE IS THE
FORECAST DEW POINTS WHICH STAT GUIDANCE SUGGESTS COULD BE AS LOW AS
THE UPPER 50S. WE DID NOT GO THAT LOW, BUT THE FORECAST DEW POINTS
LOADED ARE RESULTING IN SIMILAR APPARENT TEMPS (HEAT INDICES) AS THE
AIR TEMPERATURES, SO NO HEAT RELATED PRODUCTS YET. WE WILL CONTINUE
TO MAKE MENTION IN THE HWO. OVERALL FORECAST MAX TEMPS ARE BASED ON
FCST 850MB AND 925MB TEMPS AND WERE A STAT GUIDANCE COMPROMISE AND
PRETTY CLOSE TO OUR ONGOING FORECAST. THE SEA BREEZE SHOULD STRUGGLE
TO GET AWAY FROM THE COAST, SO MAX TEMPS JUST INLAND ARE NOT THAT
LOWER.
AS FAR AS CONVECTIVE POTENTIAL GOES, WHILE MODEL FCST CAPES LOOK
ROBUST, THERE IS ALSO FCST CIN AND THE OVERALL LFC IS PRETTY HIGH.
WITHOUT A TRIGGER AND WITH NVA FCST IT WOULD BE TOUGH TO POP MORE
THAN ISOLATED CONVECTION. NO POPS WERE CONTINUED. THE LEAST
CONFIDENCE WOULD BE THE FAR NORTHWEST PART OF OUR CWA.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
THE BIGGEST ISSUE IN THE LONGTERM CONTINUES TO BE THE POTENTIAL FOR
THE FIRST HEAT WAVE OF THE SEASON ACROSS THE PHILADELPHIA METRO AREA
THROUGH AT LEAST SATURDAY. ANOTHER NOTABLE ISSUE COULD BE THE
POSSIBLE SEVERE WEATHER LATE THIS WEEKEND AS A COLD FRONT PRESSES
DOWN FROM THE NORTHWEST TO HELP BREAK DOWN THE HOT/SOMEWHAT HUMID
AIRMASS.
SURFACE AND MID-LEVEL RIDGING WILL BE PLACE PROVIDING THE REGION
WITH A STRENGTHENING SOUTHWESTERLY FLOW. THE MID-LEVEL RIDGING WILL
BE AT ITS STRONGEST ON FRIDAY AND SUBSEQUENTLY FRIDAY LOOKS TO BE
THE HOTTEST DAY OF POSSIBLE HEAT WAVE WITH SATURDAY SLIGHTLY COOLER
WITH MORE UPPER LEVEL MOISTURE STREAMING IN. THE RELATIVELY GOOD
NEWS IS THAT DEWPOINT TEMPERATURES WILL BE RATHER DRY EVEN THOUGH
THEY ARE ADVECTING IN FROM THE SOUTHWEST...UPPER-50S TO LOW-60S. THE
COOLER DEWPOINTS WOULD ALLOW THE HEAT INDICES TO ACTUALLY FEEL A
DEGREE OR TWO COOLER THAN THE AIR TEMPERATURE. GRANTED THIS MAY BE
THE FIRST SIGNIFICANT HEAT EPISODE OF THE YEAR, BUT STILL DECIDED
NOT TO ISSUE ANY HEAT RELATED HEADLINES AND WILL KEEP MENTION IN THE
HWO.
AS FOR SUNDAY, AMPLE SURFACE HEATING WITH A BIT OF MOISTURE, AHEAD
OF THE NEXT COLD FRONT, WILL PROVIDE FOR VOLATILE CONVECTIVE
CONDITIONS. MODELS ARE SHOWING EITHER A THERMAL TROUGH OR LEE-SIDE
TROUGH NEARING FROM THE WEST LATE IN THE MORNING/EARLY AFTERNOON
TIME PERIOD. THIS SHOULD PROVIDE ENOUGH OF A SURFACE FOCUS FOR
POTENTIAL CONVECTIVE INITIATION. THE BETTER DYNAMICS WILL LIE
FURTHER TO THE NORTH ACROSS NEW YORK STATE UNDER A PASSING UPPER JET
AND STRONGER MID-LEVEL WIND FIELD. EITHER WAY THE POTENTIAL EXISTS
FOR CONVECTION GIVEN THE HOT AIRMASS THAT WILL EVENTUALLY HAVE TO
BREAK DOWN...THIS IS THE REASON THAT SPC HAS PLACED OUR FAR NORTHERN
AREA UNDER A DAY-5 OUTLOOK...THOUGH A LOT CAN CHANGE BETWEEN NOW AND
THEN.
THERE IS STILL SOME UNCERTAINTY IN THE TIMING OF THE APPROACHING
COLD FRONT BY LATE SUNDAY INTO MONDAY TIMEFRAME. THE 00Z/28 ECMWF
ENSEMBLE SHOWS THE FRONT SWEEPING THROUGH BY LATE SUNDAY NIGHT WHILE
THE 12Z/28 GEFS IS NEARLY 12 HOURS SLOWER IN PUSHING THE FRONT
THROUGH. EITHER WAY LIKELY POPS PREVAIL FOR A BETTER PART OF
SUNDAY THROUGH MONDAY TIMEFRAME WITH SCATTERED CONVECTION
POSSIBLE. HIGH PRESSURE NOSING IN BEHIND THE DEPARTING LOW LATER
ON MONDAY INTO TUESDAY PROVIDES A REFRESHING AIRMASS CHANGE WITH
SLIGHTLY BELOW NORMAL TEMPERATURES AND MUCH COOLER DEWPOINTS. THIS HIGH
PRESSURE THEN SETTLES IN ACROSS THE REGION PROVIDING VERY LITTLE
IN THE WAY OF ADVERSE SENSIBLE WEATHER. TEMPERATURES WILL MODERATE
RIGHT AROUND NORMAL FOR EARLY JUNE BY WEDNESDAY.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE 18Z TAFS KEPT THE MENTION OF THUNDER NORTH OF KPHL AND HAVE SOME
MVFR CONDITIONS FOR THURSDAY MORNING.
INTO EARLY THIS EVENING VFR CONDITIONS FORECAST FROM THE KPHL
METRO AREA AIRPORTS SOUTHWARD. LATEST FORECAST SOUNDINGS
SUGGESTING GUSTINESS SHOULD NOT PREVAIL. THERE MAY BE A 1 OR 2 HR
WINDOW LATE THIS AFTERNOON WHERE ISOLATED THUNDER COULD POP, BUT
COVERAGE AND CONFIDENCE TOO LOW TO INCLUDE IN THESE TERMINALS. AT
KRDG AND KABE, WE INCLUDED THUNDERSTORMS LATE AS THEY SHOULD BE
NEAR THE SOUTHERN EDGE OF AN ORGANIZED CLUSTER OF SHOWERS AND
THUNDERSTORMS. SOME GUSTY NORTHWEST WINDS ARE POSSIBLE, EVEN MORE
SO FOR AIRPORTS FARTHER TO THE NORTH.
WINDS OVERALL SHOULD BE SOUTHWEST AT 10 TO 15 KT, NOT ANTICIPATING
THE SEA BREEZE FRONT MAKING MUCH OF A WESTWARD PROGRESSION FROM
THE IMMEDIATE COAST.
REST OF THE EVENING VFR WITH JUST SOME DEBRIS MID TO HIGH LEVEL
CLOUDINESS AROUND. LIGHTER SOUTHWEST WINDS.
OVERNIGHT, WE CARRIED SOME MVFR CONDITIONS IN EITHER HAZE OR FOG
AT SOME OF THE MORE OUTLYING AIRPORTS. THESE CONDITIONS MAY HAVE
TO BE REVISITED FOR POSSIBLE IFR INCLUSION IF THEY ARE AFFECTED
BY PRECIPITATION. LIGHT SOUTHWEST WINDS.
ON THURSDAY, VFR CONDITIONS WITH NO CIGS EXPECTED 9JUST SOME
ISOLATED TO SCATTERED CUMULUS). WEST TO SOUTHWEST WINDS SHOULD
AVERAGE AROUND 10 KTS. NO SEA BREEZE IS EXPECTED TO AFFECT THE
TERMINALS BY 18Z AND EVEN AFTER MAY BE FIGHTING THE WEST WINDS
ABOVE THE BOUNDARY LAYER TO ARRIVE.
OUTLOOK...
FRIDAY - SATURDAY...VFR WITH SOUTHWESTERLY WINDS. POSSIBLE EARLY
MORNING HAZE MVFR VSBYS EACH MORNING.
SUNDAY - MONDAY...MAINLY VFR. SCATTERED THUNDERSTORMS THROUGH MONDAY
MORNING. WINDS BACKING TOWARDS THE NORTHWEST. LOCALLY IFR TO MVFR IN
ANY THUNDERSTORMS.
&&
.MARINE...
WAVE WATCH GUIDANCE IS VERIFYING TOO HIGH WITH SWELLS AND WE
ADJUSTED FORECAST HEIGHTS DOWN ABOUT 1 FOOT. THE GENERAL WARM
SECTOR SOUTHERLY FLOW WILL CONTINUE INTO THURSDAY. GIVEN THAT ITS
WARM IF NOT HOT AIR OVER COOLER WATER, FORECAST WIND SPEEDS ARE
LIKELY TOWARD THE HIGHER END OF EXPECTATIONS AND BELOW SMALL CRAFT
ADVISORY CONDITIONS NONETHELESS.
OUTLOOK...
CONTINUE SUB-ADVISORY CONDITIONS THROUGH AT LEAST LATE
SATURDAY ACROSS ALL OUR WATERS. WINDS WILL BEGIN TO INCREASE LATE
SATURDAY NIGHT THROUGH MONDAY FROM THE SOUTH-SOUTHWEST AS SURFACE
HIGH PRESSURE SLIDES EAST AND A COLD FRONT NEARS FROM THE
NORTHWEST. SEAS RESPOND UPWARD TO AROUND 5 FEET BY SUNDAY MORNING
AND SCA GUSTS LOOK TO COMMENCE DURING THE DAY SUNDAY. THE COLD
FRONT WILL THEN SWEEP THROUGH BY EARLY MONDAY MORNING AND THE
WINDS BACK TOWARDS THE WEST-NORTHWEST BUT MAY REMAIN GUSTY, AT
LEAST ON THE OUTER WATERS, IN THE STRONG COLD AIR ADVECTION TAKING
PLACE ALOFT.
&&
.RIP CURRENTS...
RIP CURRENT AWARENESS WEEK JUNE 2 THROUGH 8.
PSA`S WILL AIR ON KPHI NWR AND POST DAILY AROUND 545 AM. A SHORT
AWARENESS PRESS CONFERENCE IN SURF CITY - LBI, TUE JUNE 4 2PM FOR
THOSE MEDIA REPRESENTATIVES THAT ARE INTERESTED IN RAISING RIP
CURRENT AWARENESS AND CONDITIONS FAVORING UNGUARDED LIFE THREATENING
DANGER IN THE OCEAN SURF ZONE.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...HEAVENER
NEAR TERM...GIGI
SHORT TERM...GIGI
LONG TERM...HEAVENER
AVIATION...GIGI/HEAVENER
MARINE...GIGI/HEAVENER
RIP CURRENTS...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
103 PM EDT WED MAY 29 2013
.SYNOPSIS...
A WARM FRONT WILL CONTINUE TO LIFT NORTHWARD THROUGH TODAY AS AN
AREA OF HIGH PRESSURE OFF THE EASTERN SEABOARD SPREADS ITS INFLUENCE
INTO THE MID ATLANTIC REGION, BRINGING INCREASING HEAT AND HUMIDITY
TO THE AREA THROUGH THIS WEEKEND. FOR EARLY NEXT WEEK, A LOW
PRESSURE SYSTEM EMERGING FROM AROUND THE GREAT LAKES WILL SEND A
COLD FRONT THROUGH OUR REGION BY MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NEXT ESTF UPDATE CONTINUES TO BE HRRR BASED AS PER ITS BEST
HANDLING OF MESOSCALE MODELING OF ONGOING CONVECTION OR LACK
THEREOF. THIS BUMPS UP THE TIMING OF THE GREATEST THREAT IN OUR
FAR NRN CWA TO 21Z OR 22Z. ELSEWHERE WE MODIFIED THE ABERDEEN
SOUNDING AND THE CONVECTIVE TEMP (HIGH 80S) GETS REACHED LATE IN
THE AFTERNOON, SO AN ISOLATED THUNDERSTORM CAN NOT BE RULED OUT
FROM OCCURRING AND LOW POPS WERE MAINTAINED. MOST OF THE
CONVECTIVE STRENGTH PARAMETERS ARE IN THE MODERATE RANGE.
AS FAR AS SEVERE THREAT GOES, AS PREV FCSTR NOTED THAT FCST BULK
SHEAR VALUES ARE NOT VIGOROUS WITHIN OUR CWA, BUT ARE SUPPORTIVE
OF ORGANIZED CONVECTION JUST NORTH. WE HAVE TO WATCH FOR
INITIATION IN NORTHWEST PA THE NEXT HR OR TWO. SO FAR THE
INITIATION HAS BEEN SLIGHTLY MORE SUBDUED AND FARTHER NORTH THAN
THE LATEST HRRR. IF THERE IS CHANCE OF SEVERE IT IS FROM THAT
ONGOING CONVECTION BUILDING INTO OUR CWA. ETA OF ARRIVAL DOES
COINCIDE WELL FOR THUNDERSTORM STRENGTH. ENHANCED WORDING KEPT UP
NORTH.
NO BIG CHANGES WERE MADE TO ANTICIPATED MAX TEMPERATURES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
OTHER THAN TO MOVE THE CONVECTIVE PROCESS ALONG FASTER BY ABOUT AN
HOUR OR TWO, NO BIG CHANGES HERE.
THE LAST BAND OF WHATEVER HEAVY CONVECTION MOVES ESEWD FROM VCNTY
KRDG-KTTN AT AROUND 00-01Z AND WEAKENS JUST TO THE N OF KPNE AND
KACY AROUND 03Z. OTRW A WARM SUMMERLIKE NIGHT.
50 50 BLENDED 00Z/29 GFS/NAM GUIDANCE.
PATCHY FOG POSSIBLE LATE BUT PROBABLY NOTHING LIKE EARLY THIS
MORNING.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
TO START THE LONG TERM, SURFACE HIGH PRESSURE WILL BE FOUND OVER THE
CENTRAL ATLANTIC, EXTENDING ITS INFLUENCE WESTWARD INTO THE MIDDLE
ATLANTIC STATES. MEANWHILE, STRONG MID-LEVEL RIDGING WILL ALSO BE
TAKING HOLD ACROSS THE REGION. THIS LOOKS TO BE THE BEGINNING OF OUR
FIRST POTENTIAL HEAT WAVE OF THE SEASON, AS A STRENGTHENING
SOUTHWESTERLY FLOW THROUGH THE END OF THE WORK WEEK AND INTO THE
WEEKEND WILL BRING INCREASING HEAT AND HUMIDITY. MODEL 850MB AND
925MB TEMPS SUPPORT MAXIMUM TEMPERATURES EASILY REACHING THE UPPER
80S TO LOWER 90S ACROSS MOST OF THE FORECAST AREA, WITH DEWPOINTS
CLIMBING INTO THE LOWER AND MIDDLE 60S. WE WILL CONTINUE A MENTION
OF THIS EXPECTED HEAT WAVE IN OUR HAZARDOUS WEATHER OUTLOOK, AS HEAT
INDEX VALUES LOOK TO RANGE BETWEEN 90 TO 95 DEGREES.
FOR THE LATTER PART OF THE WEEKEND INTO SUNDAY, THE SURFACE HIGH
PRESSURE AND THE MID-LEVEL RIDGE WILL BOTH BEGIN TO SHIFT EASTWARD,
AS LOW PRESSURE TAKES SHAPE AROUND THE GREAT LAKES WITH A TRAILING
COLD FRONT. WITH THE OVERALL PATTERN BEGINNING TO BREAK DOWN, MODEL
RELATIVE HUMIDITIES INDICATE INCREASING MOISTURE AND CLOUDINESS FOR
SUNDAY, WITH MAXIMUM TEMPERATURES MOSTLY IN THE MIDDLE TO UPPER 80S
ACROSS THE REGION. WE HAVE RETAINED INCREASING POPS FOR
SHWRS/T-STORMS FROM WEST TO EAST ACROSS THE FORECAST AREA DURING
SUNDAY AND SUNDAY NIGHT AS THERE LOOKS TO BE AMPLE INSTABILITY AHEAD
OF THE APPROACHING FRONT. MOST OF THE MODEL GUIDANCE HAS THE COLD
FRONT PASSING THROUGH THE REGION DURING MONDAY, ALTHOUGH THERE ARE
TIMING DIFFERENCES BETWEEN THE GFS, ECMWF, AND OTHERS. AT THIS
EXTENDED TIME RANGE, WE USED A BLEND OF WPC GUIDANCE WITH CONTINUITY
FOR MOST ELEMENTS, INCLUDING TEMPERATURES AND WINDS, AND WE KEPT
HIGH CHANCE POPS IN PLACE ACROSS THE REGION THROUGH MOST OF MONDAY.
WHILE THE FINER DETAILS WILL BE WORKED OUT AS WE GET CLOSER IN TIME
TO THE FRONTAL PASSAGE AND THE MODELS ALIGN MORE WITH REGARDS TO THE
TIMING OF THE FRONT, WHAT IS APPARENT IS THAT TEMPERATURES WILL
RETURN CLOSER TO SEASONAL AVERAGES FOR MONDAY AND TUESDAY.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
WITH THE 18Z TAFS WE ARE KEEPING THE MENTION OF THUNDER NORTH OF
KPHL AND HAVE SOME MVFR CONDITIONS FOR THURSDAY MORNING.
INTO EARLY THIS EVENING VFR CONDITIONS FORECAST FROM THE KPHL
METRO AREA AIRPORTS SOUTHWARD. LATEST FORECAST SOUNDINGS
SUGGESTING GUSTINESS SHOULD NOT PREVAIL. THERE MAY BE A 1 OR 2 HR
WINDOW LATE THIS AFTERNOON WHERE ISOLATED THUNDER COULD POP, BUT
COVERAGE AND CONFIDENCE TOO LOW TO INCLUDE IN THESE TERMINALS. AT
KRDG AND KABE, WE INCLUDED THUNDERSTORMS LATE AS THEY SHOULD BE
NEAR THE SOUTHERN EDGE OF AN ORGANIZED CLUSTER OF SHOWERS AND
THUNDERSTORMS. SOME GUSTY NORTHWEST WINDS ARE POSSIBLE, EVEN MORE
SO FOR AIRPORTS FARTHER TO THE NORTH.
WINDS OVERALL SHOULD BE SOUTHWEST AT 10 TO 15 KT, NOT ANTICIPATING
THE SEA BREEZE FRONT MAKING MUCH OF A WESTWARD PROGRESSION FROM
THE IMMEDIATE COAST.
REST OF THE EVENING VFR WITH JUST SOME DEBRIS MID TO HIGH LEVEL
CLOUDINESS AROUND. LIGHTER SOUTHWEST WINDS.
OVERNIGHT, WE CARRIED SOME MVFR CONDITIONS IN EITHER HAZE OR FOG
AT SOME OF THE MORE OUTLYING AIRPORTS. THESE CONDITIONS MAY HAVE
TO BE REVISITED FOR POSSIBLE IFR INCLUSION IF THEY ARE AFFECTED
BY PRECIPITATION. LIGHT SOUTHWEST WINDS.
ON THURSDAY, VFR CONDITIONS WITH NO CIGS EXPECTED 9JUST SOME
ISOLATED TO SCATTERED CUMULUS). WEST TO SOUTHWEST WINDS SHOULD
AVERAGE AROUND 10 KTS. NO SEA BREEZE IS EXPECTED TO AFFECT THE
TERMINALS BY 18Z AND EVEN AFTER MAY BE FIGHTING THE WEST WINDS
ABOVE THE BOUNDARY LAYER TO ARRIVE.
OUTLOOK...
THURSDAY NIGHT THROUGH SATURDAY...MAINLY VFR CONDITIONS EXPECTED
WITH SOUTHWESTERLY WINDS. SOME LOCAL REDUCED VSBYS POSSIBLE EACH
MORNING IN HAZE.
SUNDAY...MAINLY VFR CONDITIONS THROUGH THE DAY, WITH SUB-VFR
CONDITIONS POSSIBLE IN SHWRS/T-STORMS BY LATE-DAY AND INTO SUNDAY
NIGHT.
&&
.MARINE...
A GENERALLY SSW 10-20 KT FLOW PREVAILS TODAY AND TONIGHT WITH NO
HEADLINE. MAYBE A BIT OF VSBY RESTRICTION IN HAZE EARLY THURSDAY
MORNING. WINDS WILL PROBABLY TURN SSE ALONG THE COASTS FOR A TIME
THIS AFTN BUT EVEN THERE..THE WSW GRADIENT FLOW MAY PREVENT MUCH
OF AN EAST OF SOUTH TURN.
OUTLOOK...
WITH OFFSHORE HIGH PRESSURE INFLUENCING THE MID ATLANTIC REGION AND
OUR WATERS, SUB-SCA CONDITIONS ARE EXPECTED ON OUR WATERS FROM
THURSDAY THROUGH THE FIRST PART OF THE WEEKEND. WINDS THROUGH THIS
TIME FRAME WILL MAINLY BE OUT OF THE SOUTHWEST, WITH SEAS IN THE 3
TO 4 FOOT RANGE FOR OUR COASTAL WATERS AND 1 TO 3 FOOT SEAS IN
DELAWARE BAY. GOING INTO SUNDAY WITH HIGH PRESSURE DRIFTING FARTHER
EAST INTO THE CENTRAL ATLANTIC AND A COLD FRONT APPROACHING THE
REGION FROM THE WEST, WE EXPECT WIND GUSTS AND SEAS TO REACH SMALL
CRAFT ADVISORY LEVELS.
&&
.RIP CURRENTS...
TODAYS RIP CURRENT RISK IS AGAIN LOW BASED ON A 2 FT SWELL 9 SECOND
PERIOD AND RAN IT EITHER WITH A WIND 2115 OR 1812 WITH NEARLY
IDENTICAL LOW RISK RESULTS FOR BOTH NJ AND DE.
RIP CURRENT AWARENESS WEEK JUNE 2 THROUGH 8.
PSA`S WILL AIR ON KPHI NWR AND POST DAILY AROUND 545 AM. A SHORT
AWARENESS PRESS CONFERENCE IN SURF CITY - LBI, TUE JUNE 4 2PM FOR
THOSE MEDIA REPRESENTATIVES THAT ARE INTERESTED IN RAISING RIP
CURRENT AWARENESS AND CONDITIONS FAVORING UNGUARDED LIFE THREATENING
DANGER IN THE OCEAN SURF ZONE.
MORE ON THIS IN THE AFD NEXT MONDAY JUNE 3.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KLINE
NEAR TERM...GIGI
SHORT TERM...DRAG
LONG TERM...KLINE
AVIATION...GIGI/KLINE
MARINE...DRAG/KLINE
RIP CURRENTS...GIGI
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1129 AM EDT WED MAY 29 2013
.SYNOPSIS...
A WARM FRONT WILL CONTINUE TO LIFT NORTHWARD THROUGH TODAY AS AN
AREA OF HIGH PRESSURE OFF THE EASTERN SEABOARD SPREADS ITS INFLUENCE
INTO THE MID ATLANTIC REGION, BRINGING INCREASING HEAT AND HUMIDITY
TO THE AREA THROUGH THIS WEEKEND. FOR EARLY NEXT WEEK, A LOW
PRESSURE SYSTEM EMERGING FROM AROUND THE GREAT LAKES WILL SEND A
COLD FRONT THROUGH OUR REGION BY MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NEXT ESTF UPDATE CONTINUES TO BE HRRR BASED AS PER ITS BEST
HANDLING OF MESOSCALE MODELING OF ONGOING CONVECTION OR LACK
THEREOF. THIS BUMPS UP THE TIMING OF THE GREATEST THREAT IN OUR
FAR NRN CWA TO 21Z OR 22Z. ELSEWHERE WE MODIFIED THE ABERDEEN
SOUNDING AND THE CONVECTIVE TEMP (HIGH 80S) GETS REACHED LATE IN
THE AFTERNOON, SO AN ISOLATED THUNDERSTORM CAN NOT BE RULED OUT
FROM OCCURRING AND LOW POPS WERE MAINTAINED. MOST OF THE
CONVECTIVE STRENGTH PARAMETERS ARE IN THE MODERATE RANGE.
AS FAR AS SEVERE THREAT GOES, AS PREV FCSTR NOTED THAT FCST BULK
SHEAR VALUES ARE NOT VIGOROUS WITHIN OUR CWA, BUT ARE SUPPORTIVE
OF ORGANIZED CONVECTION JUST NORTH. WE HAVE TO WATCH FOR
INITIATION IN NORTHWEST PA THE NEXT HR OR TWO. THUS IF THERE IS
CHANCE OF SEVERE IT IS FROM THAT ONGOING CONVECTION BUILDING INTO
OUR CWA. ETA OF ARRIVAL DOES COINCIDE WELL FOR THUNDERSTORM
STRENGTH. ENHANCED WORDING KEPT UP NORTH.
NO BIG CHANGES WERE MADE TO ANTICIPATED MAX TEMPERATURES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
OTHER THAN TO MOVE THE CONVECTIVE PROCESS ALONG FASTER BY ABOUT AN
HOUR OR TWO, NO BIG CHANGES HERE.
THE LAST BAND OF WHATEVER HEAVY CONVECTION MOVES ESEWD FROM VCNTY
KRDG-KTTN AT AROUND 00-01Z AND WEAKENS JUST TO THE N OF KPNE AND
KACY AROUND 03Z. OTRW A WARM SUMMERLIKE NIGHT.
50 50 BLENDED 00Z/29 GFS/NAM GUIDANCE.
PATCHY FOG POSSIBLE LATE BUT PROBABLY NOTHING LIKE EARLY THIS
MORNING.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
TO START THE LONG TERM, SURFACE HIGH PRESSURE WILL BE FOUND OVER THE
CENTRAL ATLANTIC, EXTENDING ITS INFLUENCE WESTWARD INTO THE MIDDLE
ATLANTIC STATES. MEANWHILE, STRONG MID-LEVEL RIDGING WILL ALSO BE
TAKING HOLD ACROSS THE REGION. THIS LOOKS TO BE THE BEGINNING OF OUR
FIRST POTENTIAL HEAT WAVE OF THE SEASON, AS A STRENGTHENING
SOUTHWESTERLY FLOW THROUGH THE END OF THE WORK WEEK AND INTO THE
WEEKEND WILL BRING INCREASING HEAT AND HUMIDITY. MODEL 850MB AND
925MB TEMPS SUPPORT MAXIMUM TEMPERATURES EASILY REACHING THE UPPER
80S TO LOWER 90S ACROSS MOST OF THE FORECAST AREA, WITH DEWPOINTS
CLIMBING INTO THE LOWER AND MIDDLE 60S. WE WILL CONTINUE A MENTION
OF THIS EXPECTED HEAT WAVE IN OUR HAZARDOUS WEATHER OUTLOOK, AS HEAT
INDEX VALUES LOOK TO RANGE BETWEEN 90 TO 95 DEGREES.
FOR THE LATTER PART OF THE WEEKEND INTO SUNDAY, THE SURFACE HIGH
PRESSURE AND THE MID-LEVEL RIDGE WILL BOTH BEGIN TO SHIFT EASTWARD,
AS LOW PRESSURE TAKES SHAPE AROUND THE GREAT LAKES WITH A TRAILING
COLD FRONT. WITH THE OVERALL PATTERN BEGINNING TO BREAK DOWN, MODEL
RELATIVE HUMIDITIES INDICATE INCREASING MOISTURE AND CLOUDINESS FOR
SUNDAY, WITH MAXIMUM TEMPERATURES MOSTLY IN THE MIDDLE TO UPPER 80S
ACROSS THE REGION. WE HAVE RETAINED INCREASING POPS FOR
SHWRS/T-STORMS FROM WEST TO EAST ACROSS THE FORECAST AREA DURING
SUNDAY AND SUNDAY NIGHT AS THERE LOOKS TO BE AMPLE INSTABILITY AHEAD
OF THE APPROACHING FRONT. MOST OF THE MODEL GUIDANCE HAS THE COLD
FRONT PASSING THROUGH THE REGION DURING MONDAY, ALTHOUGH THERE ARE
TIMING DIFFERENCES BETWEEN THE GFS, ECMWF, AND OTHERS. AT THIS
EXTENDED TIME RANGE, WE USED A BLEND OF WPC GUIDANCE WITH CONTINUITY
FOR MOST ELEMENTS, INCLUDING TEMPERATURES AND WINDS, AND WE KEPT
HIGH CHANCE POPS IN PLACE ACROSS THE REGION THROUGH MOST OF MONDAY.
WHILE THE FINER DETAILS WILL BE WORKED OUT AS WE GET CLOSER IN TIME
TO THE FRONTAL PASSAGE AND THE MODELS ALIGN MORE WITH REGARDS TO THE
TIMING OF THE FRONT, WHAT IS APPARENT IS THAT TEMPERATURES WILL
RETURN CLOSER TO SEASONAL AVERAGES FOR MONDAY AND TUESDAY.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
VFR PREVIALING FOR THIS AFTERNOON PREVAILING. SCATTERED SHOWERS
AND TSTMS POSSIBLE WITH BRIEF MVFR TO IFR CONSITIONS. IF THESE
BANDS...ESPECIALLY THE NRN PA- NNJ BAND DEVELOP...EXPECT A BRIEF
35-40 KT GUSTY NW OUTFLOW FROM THE STORMS.
TONIGHT...A LINE OF DYING SHOWERS AND EMBEDDED TSTMS SHOULD SLIDE
ESEWD FROM VCNTY KRDG-KTTN AROUND 00Z DYING OUT NEAR KPNE-KACY
AROUND 02-03Z. OTRW VFR WITH POSSIBLE MVFR HAZE FOG TOWARD DAWN
THURSDAY.
OUTLOOK...
THURSDAY THROUGH SATURDAY...MAINLY VFR CONDITIONS EXPECTED WITH
SOUTHWESTERLY WINDS. SOME LOCAL REDUCED VSBYS POSSIBLE EACH MORNING
IN HAZE.
SUNDAY...MAINLY VFR CONDITIONS THROUGH THE DAY, WITH SUB-VFR
CONDITIONS POSSIBLE IN SHWRS/T-STORMS BY LATE-DAY AND INTO SUNDAY
NIGHT.
&&
.MARINE...
A GENERALLY SSW 10-20 KT FLOW PREVAILS TODAY AND TONIGHT WITH NO
HEADLINE. MAYBE A BIT OF VSBY RESTRICTION IN HAZE EARLY THURSDAY
MORNING. WINDS WILL PROBABLY TURN SSE ALONG THE COASTS FOR A TIME
THIS AFTN BUT EVEN THERE..THE WSW GRADIENT FLOW MAY PREVENT MUCH
OF AN EAST OF SOUTH TURN.
OUTLOOK...
WITH OFFSHORE HIGH PRESSURE INFLUENCING THE MID ATLANTIC REGION AND
OUR WATERS, SUB-SCA CONDITIONS ARE EXPECTED ON OUR WATERS FROM
THURSDAY THROUGH THE FIRST PART OF THE WEEKEND. WINDS THROUGH THIS
TIME FRAME WILL MAINLY BE OUT OF THE SOUTHWEST, WITH SEAS IN THE 3
TO 4 FOOT RANGE FOR OUR COASTAL WATERS AND 1 TO 3 FOOT SEAS IN
DELAWARE BAY. GOING INTO SUNDAY WITH HIGH PRESSURE DRIFTING FARTHER
EAST INTO THE CENTRAL ATLANTIC AND A COLD FRONT APPROACHING THE
REGION FROM THE WEST, WE EXPECT WIND GUSTS AND SEAS TO REACH SMALL
CRAFT ADVISORY LEVELS.
&&
.RIP CURRENTS...
TODAYS RIP CURRENT RISK IS AGAIN LOW BASED ON A 2 FT SWELL 9 SECOND
PERIOD AND RAN IT EITHER WITH A WIND 2115 OR 1812 WITH NEARLY
IDENTICAL LOW RISK RESULTS FOR BOTH NJ AND DE.
RIP CURRENT AWARENESS WEEK JUNE 2 THROUGH 8.
PSA`S WILL AIR ON KPHI NWR AND POST DAILY AROUND 545 AM. A SHORT
AWARENESS PRESS CONFERENCE IN SURF CITY - LBI, TUE JUNE 4 2PM FOR
THOSE MEDIA REPRESENTATIVES THAT ARE INTERESTED IN RAISING RIP
CURRENT AWARENESS AND CONDITIONS FAVORING UNGUARDED LIFE THREATENING
DANGER IN THE OCEAN SURF ZONE.
MORE ON THIS IN THE AFD NEXT MONDAY JUNE 3.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KLINE
NEAR TERM...GIGI
SHORT TERM...DRAG
LONG TERM...KLINE
AVIATION...DRAG/KLINE
MARINE...DRAG/KLINE
RIP CURRENTS...DRAG
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
924 AM EDT WED MAY 29 2013
.SYNOPSIS...
A WARM FRONT WILL CONTINUE TO LIFT NORTHWARD THROUGH TODAY AS AN
AREA OF HIGH PRESSURE OFF THE EASTERN SEABOARD SPREADS ITS INFLUENCE
INTO THE MID ATLANTIC REGION, BRINGING INCREASING HEAT AND HUMIDITY
TO THE AREA THROUGH THIS WEEKEND. FOR EARLY NEXT WEEK, A LOW
PRESSURE SYSTEM EMERGING FROM AROUND THE GREAT LAKES WILL SEND A
COLD FRONT THROUGH OUR REGION BY MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LAST COUPLE OF HOURS SPC WRF RUN OF VERIFYING WELL HAS ENDED.
LATEST COUPLE OF HRRR RUNS ARE VERIFYING BETTER WITH ONGOING
CONVECTION AND IF PAST PERFORMANCE IS AN INDICATION OF FUTURE
TRENDS IT WAS USED FOR ADJUSTMENTS IN THE NEAR TERM. THE EMPHASIS
OF ALL OF THE MESOSCALE MODELS THOUGH HAS REMAINED THE SAME AS THE
SYNOPTIC SCALE FORCING FOR THE MOST ORGANIZED CONVECTION IS IN THE
NORTHERN PART OF OUR CWA. WHERE THE HRRR AND SPC WRF DIFFER ARE
WITH THE SOUTHERN EXTENSION AND DEVELOPMENT. FORECAST SOUNDING
CONVECTIVE TEMPS SUGGEST LATER IN THE AFTERNOON ALSO. THE FORMER
HAS LESS AND WE LOWERED POPS SOUTH. OVERALL THEY ARE PRETTY
SIMILAR NORTH WHERE ENHANCED WORDING WAS KEPT.
THE 12Z UA ANALYSIS IS SHOWING A LLJ CENTERED OVER LAKE ERIE WITH
THE 850MB THETA E RIDGE INTO THE FINGER LAKES OF NEW YORK. AT
500MB THOUGH WE ARE ADVECTING WARMER AIR INTO OUR CWA. REGARDLESS
THE CONVECTIVE TEMPERATURE IS FORECAST TO BE REACHED LATE IN THE
AFTERNOON.
12Z SOUNDINGS SUGGEST NO BIG ADJUSTMENTS NEEDED FOR MAX TEMPS. THE
STRATUS IS SLOWING THE RISE NORTH WHICH WAS THE BIGGEST CHANGE,
BUT THE OVERALL OUTCOME IS EXPECTED TO BE SIMILAR.
NOT MUCH 0-6KM BULK SHEAR SUPPORT FOR SVR WIND IN OUR AREA BUT A
GUSTY NW WIND OUTFLOW OF 35-40 KT IS POSSIBLE FROM KMPO TO KFWN
BETWEEN 22 AND 24Z AND POSSIBLY DOWN TO KRDG/KABE AND KTTN BETWEEN
00Z-02Z. ADDITIONALLY TT UP AROUND 50C HAS ME A LITTLE CONCERNED
BUT ON THE OTHER SIDE OF THE COIN...KI IS NOT MUCH LARGER THAN
33-34C IN THE BAND. PLEASE REFERENCE SWODY1 AND ANY SPC MCD`S
ISSUED THIS AFTN PLUS UPDATED LOCAL KPHI DISCUSSIONS.
SINCE THE NAM SPITS OUT QPF PRIOR TO 18Z...THAT TRIMS ITS BL TEMP AND
2M TEMPS BY 1-3 DEGS AND WE SEE THE DRY RAP MODEL FCSTG LOWER 90S
19Z-22Z FOR S NJ AND THE PHILLY AREA. THAT MIGHT BE 2 DEGS TO HIGH
FOR 15C AT 850 BUT ITS QUITE POSSIBLE THAT 90F WILL OCCUR AND THAT
OUR HEAT WAVE BEGINS AROUND 3-4PM THIS AFTN. THE RAPRUC CONTINUES
TO HAMMER 91-92F IN SNJ CENTRAL DE.
GRADIENT SW WIND GUST 15-20 MPH THIS AFTN. COOLING SEA BREEZES
WILL STRUGGLE TO PENETRATE INLAND IN THIS GRADIENT FLOW BEHIND THE
WFRONT AND EVEN KACY SHOULD REACH 90F WITH ONLY THE NEAREST 3MI OF
THE COAST RECEIVING THE BENEFIT OF COOLING SLY OCEAN BREEZES.
SINCE OUR HI IS BELOW 96. NO HEAT ADVY NOR EXCESSIVE HEAT WATCHES
BUT EMERGENCY MANAGEMENT HAS BEEN BRIEFED ON THE PROBABLE 3-5 DAY
EARLY SEASON HEAT WAVE FOR THE I95 CORRIDOR.
GENERALLY 50 50 BLENDED GFS NAM GUIDANCE BUT USED THE WARMER 2M
TEMPS FROM THE NAM/RGEM AND RAP-RUC TO MODIFY THE PCPN TAINTED NAM
MOS OUTPUT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
THE LAST BAND OF WHATEVER HEAVY CONVECTION MOVES ESEWD FROM VCNTY
KRDG-KTTN AT AROUND 00-01Z AND WEAKENS JUST TO THE N OF KPNE AND
KACY AROUND 03Z. OTRW A WARM SUMMERLIKE NIGHT.
50 50 BLENDED 00Z/29 GFS/NAM GUIDANCE.
PATCHY FOG POSSIBLE LATE BUT PROBABLY NOTHING LIKE EARLY THIS
MORNING.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
TO START THE LONG TERM, SURFACE HIGH PRESSURE WILL BE FOUND OVER THE
CENTRAL ATLANTIC, EXTENDING ITS INFLUENCE WESTWARD INTO THE MIDDLE
ATLANTIC STATES. MEANWHILE, STRONG MID-LEVEL RIDGING WILL ALSO BE
TAKING HOLD ACROSS THE REGION. THIS LOOKS TO BE THE BEGINNING OF OUR
FIRST POTENTIAL HEAT WAVE OF THE SEASON, AS A STRENGTHENING
SOUTHWESTERLY FLOW THROUGH THE END OF THE WORK WEEK AND INTO THE
WEEKEND WILL BRING INCREASING HEAT AND HUMIDITY. MODEL 850MB AND
925MB TEMPS SUPPORT MAXIMUM TEMPERATURES EASILY REACHING THE UPPER
80S TO LOWER 90S ACROSS MOST OF THE FORECAST AREA, WITH DEWPOINTS
CLIMBING INTO THE LOWER AND MIDDLE 60S. WE WILL CONTINUE A MENTION
OF THIS EXPECTED HEAT WAVE IN OUR HAZARDOUS WEATHER OUTLOOK, AS HEAT
INDEX VALUES LOOK TO RANGE BETWEEN 90 TO 95 DEGREES.
FOR THE LATTER PART OF THE WEEKEND INTO SUNDAY, THE SURFACE HIGH
PRESSURE AND THE MID-LEVEL RIDGE WILL BOTH BEGIN TO SHIFT EASTWARD,
AS LOW PRESSURE TAKES SHAPE AROUND THE GREAT LAKES WITH A TRAILING
COLD FRONT. WITH THE OVERALL PATTERN BEGINNING TO BREAK DOWN, MODEL
RELATIVE HUMIDITIES INDICATE INCREASING MOISTURE AND CLOUDINESS FOR
SUNDAY, WITH MAXIMUM TEMPERATURES MOSTLY IN THE MIDDLE TO UPPER 80S
ACROSS THE REGION. WE HAVE RETAINED INCREASING POPS FOR
SHWRS/T-STORMS FROM WEST TO EAST ACROSS THE FORECAST AREA DURING
SUNDAY AND SUNDAY NIGHT AS THERE LOOKS TO BE AMPLE INSTABILITY AHEAD
OF THE APPROACHING FRONT. MOST OF THE MODEL GUIDANCE HAS THE COLD
FRONT PASSING THROUGH THE REGION DURING MONDAY, ALTHOUGH THERE ARE
TIMING DIFFERENCES BETWEEN THE GFS, ECMWF, AND OTHERS. AT THIS
EXTENDED TIME RANGE, WE USED A BLEND OF WPC GUIDANCE WITH CONTINUITY
FOR MOST ELEMENTS, INCLUDING TEMPERATURES AND WINDS, AND WE KEPT
HIGH CHANCE POPS IN PLACE ACROSS THE REGION THROUGH MOST OF MONDAY.
WHILE THE FINER DETAILS WILL BE WORKED OUT AS WE GET CLOSER IN TIME
TO THE FRONTAL PASSAGE AND THE MODELS ALIGN MORE WITH REGARDS TO THE
TIMING OF THE FRONT, WHAT IS APPARENT IS THAT TEMPERATURES WILL
RETURN CLOSER TO SEASONAL AVERAGES FOR MONDAY AND TUESDAY.
&&
.AVIATION /13Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
AFTER 12Z...ANY REMAINING IFR/LIFR FOG/STRATUS QUICKLY DISSIPATES
BY 13Z AND BECOMES VFR SCT-BKN AOA 5000 FT WITH A SW WIND G15-20 KT
IN THE AFTN. SCATTERED SHOWERS AND TSTMS POSSIBLE. IF THESE
BANDS...ESPECIALLY THE NRN PA-NNJ BAND DEVELOP...EXPECT A BRIEF
35-40 KT GUSTY NW OUTFLOW FROM THE STORMS.
TONIGHT...A LINE OF DYING SHOWERS AND EMBEDDED TSTMS SHOULD SLIDE
ESEWD FROM VCNTY KRDG-KTTN AROUND 00Z DYING OUT NEAR KPNE-KACY
AROUND 02-03Z. OTRW VFR WITH POSSIBLE MVFR HAZE FOG TOWARD DAWN
THURSDAY.
OUTLOOK...
THURSDAY THROUGH SATURDAY...MAINLY VFR CONDITIONS EXPECTED WITH
SOUTHWESTERLY WINDS. SOME LOCAL REDUCED VSBYS POSSIBLE EACH MORNING
IN HAZE.
SUNDAY...MAINLY VFR CONDITIONS THROUGH THE DAY, WITH SUB-VFR
CONDITIONS POSSIBLE IN SHWRS/T-STORMS BY LATE-DAY AND INTO SUNDAY
NIGHT.
&&
.MARINE...
SEAS AND WINDS WERE FCST MUCH TOO HIGH ON THE ATLC WATERS TUE AFTN
AND NIGHT AND 44009..WITH ITS WIND DATA PROBLEMS AND ALL..STILL
BARELY JUST MADE IT 5 FT AT 11PM EDT AND NOW AROUND 4FT.
THEREFORE THE SCA WAS DISCONTINUED.
OTRW A GENERALLY SSW 10-20 KT FLOW PREVAILS TODAY AND TONIGHT WITH
NO HEADLINE. MAYBE A BIT OF VSBY RESTRICTION IN FOG AND HAZE TIL
9 AM EDT AND POSSIBLY IN HAZE EARLY THURSDAY MORNING. WINDS WILL
PROBABLY TURN SSE ALONG THE COASTS FOR A TIME THIS AFTN BUT EVEN
THERE..THE WSW GRADIENT FLOW MAY PREVENT MUCH OF AN EAST OF SOUTH
TURN.
OUTLOOK...
WITH OFFSHORE HIGH PRESSURE INFLUENCING THE MID ATLANTIC REGION AND
OUR WATERS, SUB-SCA CONDITIONS ARE EXPECTED ON OUR WATERS FROM
THURSDAY THROUGH THE FIRST PART OF THE WEEKEND. WINDS THROUGH THIS
TIME FRAME WILL MAINLY BE OUT OF THE SOUTHWEST, WITH SEAS IN THE 3
TO 4 FOOT RANGE FOR OUR COASTAL WATERS AND 1 TO 3 FOOT SEAS IN
DELAWARE BAY. GOING INTO SUNDAY WITH HIGH PRESSURE DRIFTING FARTHER
EAST INTO THE CENTRAL ATLANTIC AND A COLD FRONT APPROACHING THE
REGION FROM THE WEST, WE EXPECT WIND GUSTS AND SEAS TO REACH SMALL
CRAFT ADVISORY LEVELS.
&&
.RIP CURRENTS...
TODAYS RIP CURRENT RISK IS AGAIN LOW BASED ON A 2 FT SWELL 9 SECOND
PERIOD AND RAN IT EITHER WITH A WIND 2115 OR 1812 WITH NEARLY
IDENTICAL LOW RISK RESULTS FOR BOTH NJ AND DE.
RIP CURRENT AWARENESS WEEK JUNE 2 THROUGH 8.
PSA`S WILL AIR ON KPHI NWR AND POST DAILY AROUND 545 AM. A SHORT
AWARENESS PRESS CONFERENCE IN SURF CITY - LBI, TUE JUNE 4 2PM FOR
THOSE MEDIA REPRESENTATIVES THAT ARE INTERESTED IN RAISING RIP
CURRENT AWARENESS AND CONDITIONS FAVORING UNGUARDED LIFE THREATENING
DANGER IN THE OCEAN SURF ZONE.
MORE ON THIS IN THE AFD NEXT MONDAY JUNE 3.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KLINE
NEAR TERM...DRAG/GIGI
SHORT TERM...DRAG
LONG TERM...KLINE
AVIATION...DRAG/KLINE
MARINE...DRAG/KLINE
RIP CURRENTS...DRAG
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
804 AM EDT WED MAY 29 2013
.SYNOPSIS...
A WARM FRONT WILL CONTINUE TO LIFT NORTHWARD THROUGH TODAY AS AN
AREA OF HIGH PRESSURE OFF THE EASTERN SEABOARD SPREADS ITS INFLUENCE
INTO THE MID ATLANTIC REGION, BRINGING INCREASING HEAT AND HUMIDITY
TO THE AREA THROUGH THIS WEEKEND. FOR EARLY NEXT WEEK, A LOW
PRESSURE SYSTEM EMERGING FROM AROUND THE GREAT LAKES WILL SEND A
COLD FRONT THROUGH OUR REGION BY MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE DENSE FOG ADVISORY WAS ALLOWED TO EXPIRE.
THE PAST TWO CYCLES OF THE SPCWRF HAD WHAT I THOUGHT WERE EXCELLENT
HOURLY RADAR SIMULATIONS OF WHAT HAS TRANSPIRED FROM LERIE TO THE
DELMARVA INCLUDING OUR FORECAST AREA. THAT SPCWRF IS RELIED ON
HEAVILY AGAIN FOR THE UPCOMING FORECAST FOR TODAY AND TONIGHT.
TODAY...THE 00Z/29 VERSION OF THE SPCWRF IS MORE VIGOROUS ACROSS
OUR AREA THIS AFTN/EVENING THAN I ANTICIPATED PRIOR TO BEGINNING
THE SHIFT. STILL NOT QUITE SURE IF TWO BANDS OF DECENT CONVECTION
CAN DEVELOP SEWD ACROSS OUR FCST AREA...THE FIRST SCT CONVECTIVE
ELEMENTS FROM KDCA- KBLM AROUND 20Z AND WEAKENING ESEWD OVER FAR
SNJ NEAR SUNSET.
THE MORE SIGNIFICANT BAND OF STRONG STORMS FOR WHICH I HAVE MUCH
GREATER CONFIDENCE...WILL PROBABLY DEVELOP NEAR THE NY/PA BORDER
MID OR LATE AFTN AND ORGANIZE ESEWD TO NEAR I80 BY AROUND 8 PM EDT.
GFS ML CAPE WILL RISE TO NEAR 1500J ALONG I95 THIS AFTN. THIS
SUPPLIES DECENT ENERGY FOR CONVECTION PROVIDED ITS NOT TOO DRY
ALOFT AND THAT THERE CAN BE SOME SORT OF BOUNDARY TRIGGERING AND
ORGANIZING THE CONVECTION. THE 06Z RAP-RUC AGREES ON THIS
SCENARIO.
NOT MUCH 0-6KM BULK SHEAR SUPPORT FOR SVR WIND IN OUR AREA BUT A
GUSTY NW WIND OUTFLOW OF 35-40 KT IS POSSIBLE FROM KMPO TO KFWN
BETWEEN 22 AND 24Z AND POSSIBLY DOWN TO KRDG/KABE AND KTTN BETWEEN
00Z-02Z. ADDITIONALLY TT UP AROUND 50C HAS ME A LITTLE CONCERNED
BUT ON THE OTHER SIDE OF THE COIN...KI IS NOT MUCH LARGER THAN
33-342C IN THE BAND SO AM NOT CONVINCED THAT THE SPC WRF VIGOR
WILL BE REALIZED. NEVERTHELESS...THIS MODEL HAS GARNERED MY
RESPECT SINCE ITS GENERALLY A SUCCESSFUL SIMULATOR OF THE FUTURE
REALITY. PLEASE REFERENCE SWODY1 AND ANY SPC MCD`S ISSUED THIS
AFTN PLUS UPDATED LOCAL KPHI DISCUSSIONS.
SINCE THE NAM SPITS OUT QPF PRIOR TO 18Z...THAT TRIMS ITS BL TEMP AND
2M TEMPS BY 1-3 DEGS AND WE SEE THE DRY RAP MODEL FCSTG LOWER 90S
19Z-22Z FOR S NJ AND THE PHILLY AREA. THAT MIGHT BE 2 DEGS TO HIGH
FOR 15C AT 850 BUT ITS QUITE POSSIBLE THAT 90F WILL OCCUR AND THAT
OUR HEAT WAVE BEGINS AROUND 3-4PM THIS AFTN. THE RAPRUC CONTINUES
TO HAMMER 91-92F IN SNJ CENTRAL DE.
GRADIENT SW WIND GUST 15-20 MPH THIS AFTN. COOLING SEA BREEZES
WILL STRUGGLE TO PENETRATE INLAND IN THIS GRADIENT FLOW BEHIND THE
WFRONT AND EVEN KACY SHOULD REACH 90F WITH ONLY THE NEAREST 3MI OF
THE COAST RECEIVING THE BENEFIT OF COOLING SLY OCEAN BREEZES.
SINCE OUR HI IS BELOW 96. NO HEAT ADVY NOR EXCESSIVE HEAT WATCHES
BUT EMERGENCY MANAGEMENT HAS BEEN BRIEFED ON THE PROBABLE 3-5 DAY
EARLY SEASON HEAT WAVE FOR THE I95 CORRIDOR.
GENERALLY 50 50 BLENDED GFS NAM GUIDANCE BUT USED THE WARMER 2M
TEMPS FROM THE NAM/RGEM AND RAP-RUC TO MODIFY THE PCPN TAINTED NAM
MOS OUTPUT.
PHL AROUND 89 TODAY AND 90-91 IN SNJ EVEN TO KACY AND S DE VCNTY KGED.
THE 06Z NAM IS SLIGHTLY WARMER AND SO AM CONFIDENT OF AT LEAST 89 IN
PHL AND THERE IS A 50 PCT CHC PHL WILL NUDGE 90F WITH A 20 PCT
REACHING 92. CONFIDENCE ON REACHING THE MAX TEMPS VALUES FCST N OF I80
IS LESS THAN AVG.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
THE LAST BAND OF WHATEVER HEAVY CONVECTION MOVES ESEWD FROM VCNTY
KRDG-KTTN AT AROUND 00-01Z AND WEAKENS JUST TO THE N OF KPNE AND
KACY AROUND 03Z. OTRW A WARM SUMMERLIKE NIGHT.
50 50 BLENDED 00Z/29 GFS/NAM GUIDANCE.
PATCHY FOG POSSIBLE LATE BUT PROBABLY NOTHING LIKE EARLY THIS
MORNING.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
TO START THE LONG TERM, SURFACE HIGH PRESSURE WILL BE FOUND OVER THE
CENTRAL ATLANTIC, EXTENDING ITS INFLUENCE WESTWARD INTO THE MIDDLE
ATLANTIC STATES. MEANWHILE, STRONG MID-LEVEL RIDGING WILL ALSO BE
TAKING HOLD ACROSS THE REGION. THIS LOOKS TO BE THE BEGINNING OF OUR
FIRST POTENTIAL HEAT WAVE OF THE SEASON, AS A STRENGTHENING
SOUTHWESTERLY FLOW THROUGH THE END OF THE WORK WEEK AND INTO THE
WEEKEND WILL BRING INCREASING HEAT AND HUMIDITY. MODEL 850MB AND
925MB TEMPS SUPPORT MAXIMUM TEMPERATURES EASILY REACHING THE UPPER
80S TO LOWER 90S ACROSS MOST OF THE FORECAST AREA, WITH DEWPOINTS
CLIMBING INTO THE LOWER AND MIDDLE 60S. WE WILL CONTINUE A MENTION
OF THIS EXPECTED HEAT WAVE IN OUR HAZARDOUS WEATHER OUTLOOK, AS HEAT
INDEX VALUES LOOK TO RANGE BETWEEN 90 TO 95 DEGREES.
FOR THE LATTER PART OF THE WEEKEND INTO SUNDAY, THE SURFACE HIGH
PRESSURE AND THE MID-LEVEL RIDGE WILL BOTH BEGIN TO SHIFT EASTWARD,
AS LOW PRESSURE TAKES SHAPE AROUND THE GREAT LAKES WITH A TRAILING
COLD FRONT. WITH THE OVERALL PATTERN BEGINNING TO BREAK DOWN, MODEL
RELATIVE HUMIDITIES INDICATE INCREASING MOISTURE AND CLOUDINESS FOR
SUNDAY, WITH MAXIMUM TEMPERATURES MOSTLY IN THE MIDDLE TO UPPER 80S
ACROSS THE REGION. WE HAVE RETAINED INCREASING POPS FOR
SHWRS/T-STORMS FROM WEST TO EAST ACROSS THE FORECAST AREA DURING
SUNDAY AND SUNDAY NIGHT AS THERE LOOKS TO BE AMPLE INSTABILITY AHEAD
OF THE APPROACHING FRONT. MOST OF THE MODEL GUIDANCE HAS THE COLD
FRONT PASSING THROUGH THE REGION DURING MONDAY, ALTHOUGH THERE ARE
TIMING DIFFERENCES BETWEEN THE GFS, ECMWF, AND OTHERS. AT THIS
EXTENDED TIME RANGE, WE USED A BLEND OF WPC GUIDANCE WITH CONTINUITY
FOR MOST ELEMENTS, INCLUDING TEMPERATURES AND WINDS, AND WE KEPT
HIGH CHANCE POPS IN PLACE ACROSS THE REGION THROUGH MOST OF MONDAY.
WHILE THE FINER DETAILS WILL BE WORKED OUT AS WE GET CLOSER IN TIME
TO THE FRONTAL PASSAGE AND THE MODELS ALIGN MORE WITH REGARDS TO THE
TIMING OF THE FRONT, WHAT IS APPARENT IS THAT TEMPERATURES WILL
RETURN CLOSER TO SEASONAL AVERAGES FOR MONDAY AND TUESDAY.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
AFTER 12Z...ANY REMAINING IFR/LIFR FOG/STRATUS QUICKLY DISSIPATES
BY 13Z AND BECOMES VFR SCT-BKN AOA 5000 FT WITH A SW WIND G15-20 KT
IN THE AFTN. TWO BANDS OF TSTMS ARE MODELED BY THE SPCWRF AS DISCUSSED
IN DETAIL IN OUR NEAR TERM SECTION. HAVE FOLLOWED THIS FOR THE 06Z
AND UPCOMING 12Z TAFS WITH SUPPORT FROM THE LATEST 07Z RAPRUC. IF
THESE BANDS...ESPECIALLY THE NRN PA-NNJ BAND DEVELOP...EXPECT A
BRIEF 35-40 KT GUSTY NW OUTFLOW FROM THE STORMS.
TONIGHT...A LINE OF DYING SHOWERS AND EMBEDDED TSTMS SHOULD SLIDE
ESEWD FROM VCNTY KRDG-KTTN AROUND 00Z DYING OUT NEAR KPNE-KACY
AROUND 02-03Z. OTRW VFR WITH POSSIBLE MVFR HAZE FOG TOWARD DAWN
THURSDAY.
OUTLOOK...
THURSDAY THROUGH SATURDAY...MAINLY VFR CONDITIONS EXPECTED WITH
SOUTHWESTERLY WINDS. SOME LOCAL REDUCED VSBYS POSSIBLE EACH MORNING
IN HAZE.
SUNDAY...MAINLY VFR CONDITIONS THROUGH THE DAY, WITH SUB-VFR
CONDITIONS POSSIBLE IN SHWRS/T-STORMS BY LATE-DAY AND INTO SUNDAY
NIGHT.
&&
.MARINE...
SEAS AND WINDS WERE FCST MUCH TOO HIGH ON THE ATLC WATERS TUE AFTN
AND NIGHT AND 44009..WITH ITS WIND DATA PROBLEMS AND ALL..STILL
BARELY JUST MADE IT 5 FT AT 11PM EDT AND NOW AROUND 4FT.
THEREFORE THE SCA WAS DISCONTINUED.
OTRW A GENERALLY SSW 10-20 KT FLOW PREVAILS TODAY AND TONIGHT WITH
NO HEADLINE. MAYBE A BIT OF VSBY RESTRICTION IN FOG AND HAZE TIL
9 AM EDT AND POSSIBLY IN HAZE EARLY THURSDAY MORNING. WINDS WILL
PROBABLY TURN SSE ALONG THE COASTS FOR A TIME THIS AFTN BUT EVEN
THERE..THE WSW GRADIENT FLOW MAY PREVENT MUCH OF AN EAST OF SOUTH
TURN.
OUTLOOK...
WITH OFFSHORE HIGH PRESSURE INFLUENCING THE MID ATLANTIC REGION AND
OUR WATERS, SUB-SCA CONDITIONS ARE EXPECTED ON OUR WATERS FROM
THURSDAY THROUGH THE FIRST PART OF THE WEEKEND. WINDS THROUGH THIS
TIME FRAME WILL MAINLY BE OUT OF THE SOUTHWEST, WITH SEAS IN THE 3
TO 4 FOOT RANGE FOR OUR COASTAL WATERS AND 1 TO 3 FOOT SEAS IN
DELAWARE BAY. GOING INTO SUNDAY WITH HIGH PRESSURE DRIFTING FARTHER
EAST INTO THE CENTRAL ATLANTIC AND A COLD FRONT APPROACHING THE
REGION FROM THE WEST, WE EXPECT WIND GUSTS AND SEAS TO REACH SMALL
CRAFT ADVISORY LEVELS.
&&
.RIP CURRENTS...
TODAYS RIP CURRENT RISK IS AGAIN LOW BASED ON A 2 FT SWELL 9 SECOND
PERIOD AND RAN IT EITHER WITH A WIND 2115 OR 1812 WITH NEARLY
IDENTICAL LOW RISK RESULTS FOR BOTH NJ AND DE.
RIP CURRENT AWARENESS WEEK JUNE 2 THROUGH 8.
PSA`S WILL AIR ON KPHI NWR AND POST DAILY AROUND 545 AM. A SHORT
AWARENESS PRESS CONFERENCE IN SURF CITY - LBI, TUE JUNE 4 2PM FOR
THOSE MEDIA REPRESENTATIVES THAT ARE INTERESTED IN RAISING RIP
CURRENT AWARENESS AND CONDITIONS FAVORING UNGUARDED LIFE THREATENING
DANGER IN THE OCEAN SURF ZONE.
MORE ON THIS IN THE AFD NEXT MONDAY JUNE 3.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KLINE
NEAR TERM...DRAG
SHORT TERM...DRAG
LONG TERM...KLINE
AVIATION...DRAG/KLINE
MARINE...DRAG/KLINE
RIP CURRENTS...DRAG
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
624 AM EDT WED MAY 29 2013
.SYNOPSIS...
A WARM FRONT WILL CONTINUE TO LIFT NORTHWARD THROUGH TODAY AS AN
AREA OF HIGH PRESSURE OFF THE EASTERN SEABOARD SPREADS ITS INFLUENCE
INTO THE MID ATLANTIC REGION, BRINGING INCREASING HEAT AND HUMIDITY
TO THE AREA THROUGH THIS WEEKEND. FOR EARLY NEXT WEEK, A LOW
PRESSURE SYSTEM EMERGING FROM AROUND THE GREAT LAKES WILL SEND A
COLD FRONT THROUGH OUR REGION BY MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A DENSE FOG ADVISORY WAS POSTED WHERE VSBY NEAR OR BELOW 1/4 MI
AND NOW EXTENDED THRU 8AM THO IMPROVEMENT SHOULD BE NOTICED BEGINNING
AROUND 7 AM. DROPPED THE ADVY NW BURLINGTON CTY NJ.
OTRW SHOWERS ENDING BY 7 OR 8 AM IN POCONOS AND NW NJ.
THE PAST TWO CYCLES OF THE SPCWRF HAD WHAT I THOUGHT WERE EXCELLENT
HOURLY RADAR SIMULATIONS OF WHAT HAS TRANSPIRED FROM LERIE TO THE
DELMARVA INCLUDING OUR FORECAST AREA. THAT SPCWRF IS RELIED ON
HEAVILY AGAIN FOR THE UPCOMING FORECAST FOR TODAY AND TONIGHT.
TODAY...THE 00Z/29 VERSION OF THE SPCWRF IS MORE VIGOROUS ACROSS
OUR AREA THIS AFTN/EVENING THAN I ANTICIPATED PRIOR TO BEGINNING
THE SHIFT. STILL NOT QUITE SURE IF TWO BANDS OF DECENT CONVECTION
CAN DEVELOP SEWD ACROSS OUR FCST AREA...THE FIRST SCT CONVECTIVE
ELEMENTS FROM KDCA- KBLM AROUND 20Z AND WEAKENING ESEWD OVER FAR
SNJ NEAR SUNSET.
THE MORE SIGNIFICANT BAND OF STRONG STORMS FOR WHICH I HAVE MUCH
GREATER CONFIDENCE...WILL PROBABLY DEVELOP NEAR THE NY/PA BORDER
MID OR LATE AFTN AND ORGANIZE ESEWD TO NEAR I80 BY AROUND 8 PM EDT.
GFS ML CAPE WILL RISE TO NEAR 1500J ALONG I95 THIS AFTN. THIS
SUPPLIES DECENT ENERGY FOR CONVECTION PROVIDED ITS NOT TOO DRY
ALOFT AND THAT THERE CAN BE SOME SORT OF BOUNDARY TRIGGERING AND
ORGANIZING THE CONVECTION. THE 06Z RAP-RUC AGREES ON THIS
SCENARIO.
NOT MUCH 0-6KM BULK SHEAR SUPPORT FOR SVR WIND IN OUR AREA BUT A
GUSTY NW WIND OUTFLOW OF 35-40 KT IS POSSIBLE FROM KMPO TO KFWN
BETWEEN 22 AND 24Z AND POSSIBLY DOWN TO KRDG/KABE AND KTTN BETWEEN
00Z-02Z. ADDITIONALLY TT UP AROUND 50C HAS ME A LITTLE CONCERNED
BUT ON THE OTHER SIDE OF THE COIN...KI IS NOT MUCH LARGER THAN
33-342C IN THE BAND SO AM NOT CONVINCED THAT THE SPC WRF VIGOR
WILL BE REALIZED. NEVERTHELESS...THIS MODEL HAS GARNERED MY
RESPECT SINCE ITS GENERALLY A SUCCESSFUL SIMULATOR OF THE FUTURE
REALITY. PLEASE REFERENCE SWODY1 AND ANY SPC MCD`S ISSUED THIS
AFTN PLUS UPDATED LOCAL KPHI DISCUSSIONS.
SINCE THE NAM SPITS OUT QPF PRIOR TO 18Z...THAT TRIMS ITS BL TEMP AND
2M TEMPS BY 1-3 DEGS AND WE SEE THE DRY RAP MODEL FCSTG LOWER 90S
19Z-22Z FOR S NJ AND THE PHILLY AREA. THAT MIGHT BE 2 DEGS TO HIGH
FOR 15C AT 850 BUT ITS QUITE POSSIBLE THAT 90F WILL OCCUR AND THAT
OUR HEAT WAVE BEGINS AROUND 3-4PM THIS AFTN. THE RAPRUC CONTINUES
TO HAMMER 91-92F IN SNJ CENTRAL DE.
GRADIENT SW WIND GUST 15-20 MPH THIS AFTN. COOLING SEA BREEZES
WILL STRUGGLE TO PENETRATE INLAND IN THIS GRADIENT FLOW BEHIND THE
WFRONT AND EVEN KACY SHOULD REACH 90F WITH ONLY THE NEAREST 3MI OF
THE COAST RECEIVING THE BENEFIT OF COOLING SLY OCEAN BREEZES.
SINCE OUR HI IS BELOW 96. NO HEAT ADVY NOR EXCESSIVE HEAT WATCHES
BUT EMERGENCY MANAGEMENT HAS BEEN BRIEFED ON THE PROBABLE 3-5 DAY
EARLY SEASON HEAT WAVE FOR THE I95 CORRIDOR.
GENERALLY 50 50 BLENDED GFS NAM GUIDANCE BUT USED THE WARMER 2M
TEMPS FROM THE NAM/RGEM AND RAP-RUC TO MODIFY THE PCPN TAINTED NAM
MOS OUTPUT.
PHL AROUND 89 TODAY AND 90-91 IN SNJ EVEN TO KACY AND S DE VCNTY KGED.
THE 06Z NAM IS SLIGHTLY WARMER AND SO AM CONFIDENT OF AT LEAST 89 IN
PHL AND THERE IS A 50 PCT CHC PHL WILL NUDGE 90F WITH A 20 PCT
REACHING 92. CONFIDENCE ON REACHING THE MAX TEMPS VALUES FCST N OF I80
IS LESS THAN AVG.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
THE LAST BAND OF WHATEVER HEAVY CONVECTION MOVES ESEWD FROM VCNTY
KRDG-KTTN AT AROUND 00-01Z AND WEAKENS JUST TO THE N OF KPNE AND
KACY AROUND 03Z. OTRW A WARM SUMMERLIKE NIGHT.
50 50 BLENDED 00Z/29 GFS/NAM GUIDANCE.
PATCHY FOG POSSIBLE LATE BUT PROBABLY NOTHING LIKE EARLY THIS
MORNING.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
TO START THE LONG TERM, SURFACE HIGH PRESSURE WILL BE FOUND OVER THE
CENTRAL ATLANTIC, EXTENDING ITS INFLUENCE WESTWARD INTO THE MIDDLE
ATLANTIC STATES. MEANWHILE, STRONG MID-LEVEL RIDGING WILL ALSO BE
TAKING HOLD ACROSS THE REGION. THIS LOOKS TO BE THE BEGINNING OF OUR
FIRST POTENTIAL HEAT WAVE OF THE SEASON, AS A STRENGTHENING
SOUTHWESTERLY FLOW THROUGH THE END OF THE WORK WEEK AND INTO THE
WEEKEND WILL BRING INCREASING HEAT AND HUMIDITY. MODEL 850MB AND
925MB TEMPS SUPPORT MAXIMUM TEMPERATURES EASILY REACHING THE UPPER
80S TO LOWER 90S ACROSS MOST OF THE FORECAST AREA, WITH DEWPOINTS
CLIMBING INTO THE LOWER AND MIDDLE 60S. WE WILL CONTINUE A MENTION
OF THIS EXPECTED HEAT WAVE IN OUR HAZARDOUS WEATHER OUTLOOK, AS HEAT
INDEX VALUES LOOK TO RANGE BETWEEN 90 TO 95 DEGREES.
FOR THE LATTER PART OF THE WEEKEND INTO SUNDAY, THE SURFACE HIGH
PRESSURE AND THE MID-LEVEL RIDGE WILL BOTH BEGIN TO SHIFT EASTWARD,
AS LOW PRESSURE TAKES SHAPE AROUND THE GREAT LAKES WITH A TRAILING
COLD FRONT. WITH THE OVERALL PATTERN BEGINNING TO BREAK DOWN, MODEL
RELATIVE HUMIDITIES INDICATE INCREASING MOISTURE AND CLOUDINESS FOR
SUNDAY, WITH MAXIMUM TEMPERATURES MOSTLY IN THE MIDDLE TO UPPER 80S
ACROSS THE REGION. WE HAVE RETAINED INCREASING POPS FOR
SHWRS/T-STORMS FROM WEST TO EAST ACROSS THE FORECAST AREA DURING
SUNDAY AND SUNDAY NIGHT AS THERE LOOKS TO BE AMPLE INSTABILITY AHEAD
OF THE APPROACHING FRONT. MOST OF THE MODEL GUIDANCE HAS THE COLD
FRONT PASSING THROUGH THE REGION DURING MONDAY, ALTHOUGH THERE ARE
TIMING DIFFERENCES BETWEEN THE GFS, ECMWF, AND OTHERS. AT THIS
EXTENDED TIME RANGE, WE USED A BLEND OF WPC GUIDANCE WITH CONTINUITY
FOR MOST ELEMENTS, INCLUDING TEMPERATURES AND WINDS, AND WE KEPT
HIGH CHANCE POPS IN PLACE ACROSS THE REGION THROUGH MOST OF MONDAY.
WHILE THE FINER DETAILS WILL BE WORKED OUT AS WE GET CLOSER IN TIME
TO THE FRONTAL PASSAGE AND THE MODELS ALIGN MORE WITH REGARDS TO THE
TIMING OF THE FRONT, WHAT IS APPARENT IS THAT TEMPERATURES WILL
RETURN CLOSER TO SEASONAL AVERAGES FOR MONDAY AND TUESDAY.
&&
.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THROUGH 12Z...IFR/LIFR CONDS IN ST/FOG MUCH OF E PA AND NNJ WITH
SCT SHOWERS ALONG AND N OF I80. CALM WIND. FOR FAR S NJ AND
DE...GENERALLY VFR WITH A S WIND OF 10 KT.
AFTER 12Z...ANY REMAINING IFR/LIFR FOG/STRATUS QUICKLY DISSIPATES
BY 13Z AND BECOMES VFR SCT-BKN AOA 5000 FT WITH A SW WIND G15-20 KT
IN THE AFTN. TWO BANDS OF TSTMS ARE MODELED BY THE SPCWRF AS DISCUSSED
IN DETAIL IN OUR NEAR TERM SECTION. HAVE FOLLOWED THIS FOR THE 06Z
AND UPCOMING 12Z TAFS WITH SUPPORT FROM THE LATEST 07Z RAPRUC. IF
THESE BANDS...ESPECIALLY THE NRN PA-NNJ BAND DEVELOP...EXPECT A
BRIEF 35-40 KT GUSTY NW OUTFLOW FROM THE STORMS.
TONIGHT...A LINE OF DYING SHOWERS AND EMBEDDED TSTMS SHOULD SLIDE
ESEWD FROM VCNTY KRDG-KTTN AROUND 00Z DYING OUT NEAR KPNE-KACY
AROUND 02-03Z. OTRW VFR WITH POSSIBLE MVFR HAZE FOG TOWARD DAWN
THURSDAY.
OUTLOOK...
THURSDAY THROUGH SATURDAY...MAINLY VFR CONDITIONS EXPECTED WITH
SOUTHWESTERLY WINDS. SOME LOCAL REDUCED VSBYS POSSIBLE EACH MORNING
IN HAZE.
SUNDAY...MAINLY VFR CONDITIONS THROUGH THE DAY, WITH SUB-VFR
CONDITIONS POSSIBLE IN SHWRS/T-STORMS BY LATE-DAY AND INTO SUNDAY
NIGHT.
&&
.MARINE...
SEAS AND WINDS WERE FCST MUCH TOO HIGH ON THE ATLC WATERS TUE AFTN
AND NIGHT AND 44009..WITH ITS WIND DATA PROBLEMS AND ALL..STILL
BARELY JUST MADE IT 5 FT AT 11PM EDT AND NOW AROUND 4FT.
THEREFORE THE SCA WAS DISCONTINUED.
OTRW A GENERALLY SSW 10-20 KT FLOW PREVAILS TODAY AND TONIGHT WITH
NO HEADLINE. MAYBE A BIT OF VSBY RESTRICTION IN FOG AND HAZE TIL
9 AM EDT AND POSSIBLY IN HAZE EARLY THURSDAY MORNING. WINDS WILL
PROBABLY TURN SSE ALONG THE COASTS FOR A TIME THIS AFTN BUT EVEN
THERE..THE WSW GRADIENT FLOW MAY PREVENT MUCH OF AN EAST OF SOUTH
TURN.
OUTLOOK...
WITH OFFSHORE HIGH PRESSURE INFLUENCING THE MID ATLANTIC REGION AND
OUR WATERS, SUB-SCA CONDITIONS ARE EXPECTED ON OUR WATERS FROM
THURSDAY THROUGH THE FIRST PART OF THE WEEKEND. WINDS THROUGH THIS
TIME FRAME WILL MAINLY BE OUT OF THE SOUTHWEST, WITH SEAS IN THE 3
TO 4 FOOT RANGE FOR OUR COASTAL WATERS AND 1 TO 3 FOOT SEAS IN
DELAWARE BAY. GOING INTO SUNDAY WITH HIGH PRESSURE DRIFTING FARTHER
EAST INTO THE CENTRAL ATLANTIC AND A COLD FRONT APPROACHING THE
REGION FROM THE WEST, WE EXPECT WIND GUSTS AND SEAS TO REACH SMALL
CRAFT ADVISORY LEVELS.
&&
.RIP CURRENTS...
TODAYS RIP CURRENT RISK IS AGAIN LOW BASED ON A 2 FT SWELL 9 SECOND
PERIOD AND RAN IT EITHER WITH A WIND 2115 OR 1812 WITH NEARLY
IDENTICAL LOW RISK RESULTS FOR BOTH NJ AND DE.
RIP CURRENT AWARENESS WEEK JUNE 2 THROUGH 8.
PSA`S WILL AIR ON KPHI NWR AND POST DAILY AROUND 545 AM. A SHORT
AWARENESS PRESS CONFERENCE IN SURF CITY - LBI, TUE JUNE 4 2PM FOR
THOSE MEDIA REPRESENTATIVES THAT ARE INTERESTED IN RAISING RIP
CURRENT AWARENESS AND CONDITIONS FAVORING UNGUARDED LIFE THREATENING
DANGER IN THE OCEAN SURF ZONE.
MORE ON THIS IN THE AFD NEXT MONDAY JUNE 3.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...DENSE FOG ADVISORY UNTIL 8 AM EDT THIS MORNING FOR PAZ054-055-
060>062-071-101>106.
NJ...DENSE FOG ADVISORY UNTIL 8 AM EDT THIS MORNING FOR NJZ007>010-
015.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KLINE
NEAR TERM...DRAG 624A
SHORT TERM...DRAG
LONG TERM...KLINE
AVIATION...DRAG/KLINE
MARINE...DRAG/KLINE
RIP CURRENTS...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
351 AM EDT WED MAY 29 2013
.SYNOPSIS...
A WARM FRONT WILL CONTINUE TO LIFT NORTHWARD THROUGH TODAY AS AN
AREA OF HIGH PRESSURE OFF THE EASTERN SEABOARD SPREADS ITS INFLUENCE
INTO THE MID ATLANTIC REGION, BRINGING INCREASING HEAT AND HUMIDITY
TO THE AREA THROUGH THIS WEEKEND. FOR EARLY NEXT WEEK, A LOW
PRESSURE SYSTEM EMERGING FROM AROUND THE GREAT LAKES WILL SEND A
COLD FRONT THROUGH OUR REGION BY MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A WARM FRONT IS DRAPED ACROSS SOUTHERN NEW JERSEY AND NORTH/CENTRAL
DELMARVA EARLY THIS MORNING. NORTH OF THE BOUNDARY, LOW CLOUDS AND
DENSE FOG WILL PERSIST, WHILE SOUTH OF THE FRONT, WE DO NOT EXPECT
FOG TO DEVELOP UNTIL OVERNIGHT.
SHOWERS DIMINISHING IN THEIR EASTWARD PROGRESS ACROSS N PA AT THE
VERY WORST WILL JUST SKIM MOUNT POCONO AND HIGH POINT BETWEEN 3 AM
AND 6 AM.
THE PAST TWO CYCLES OF THE SPCWRF HAD WHAT I THOUGHT WERE EXCELLENT
HOURLY RADAR SIMULATIONS OF WHAT HAS TRANSPIRED FROM LERIE TO THE
DELMARVA INCLUDING OUR FORECAST AREA. THAT SPCWRF IS RELIED ON
HEAVILY AGAIN FOR THE UPCOMING FORECAST FOR TODAY AND TONIGHT.
TODAY...THE 00Z/29 VERSION OF THE SPCWRF IS MORE VIGOROUS ACROSS
OUR AREA THIS AFTN/EVENING THAN I ANTICIPATED. STILL NOT QUITE
SURE IF TWO BANDS OF DECENT CONVECTION CAN DEVELOP SEWD ACROSS
OUR FCST AREA...THE FIRST FROM KDCA-KBLM AROUND 21Z AND WEAKENING
ESEWD OVER FAR SNJ NEAR SUNSET.
THE MORE SIGNIFICANT BAND OF STRONG STORMS WILL PROBABLY DEVELOP
NEAR THE NY/PA BORDER MID AFTN AND ORGANIZE ESEWD TO NEAR I80 BY
AROUND 8 PM EDT. GFS ML CAPE WILL RISE TO NEAR 1500J ALONG I95 THIS
AFTN. THIS SUPPLIES DECENT ENERGY FOR CONVECTION PROVIDED ITS NOT
TOO DRY ALOFT AND THAT THERE CAN BE SOME SORT OF BOUNDARY TRIGGERING
AND ORGANIZING THE CONVECTION.
NOT MUCH 0-6KM BULK SHEAR SUPPORT FOR SVR WIND IN OUR AREA BUT A
GUSTY NW WIND OUTFLOW OF 35-40 KT IS POSSIBLE FROM KMPO TO KFWN
AND POSSIBLY DOWN TO KRDG/KABE AND KTTN. ADDITIONALLY TT UP AROUND
50C HAS ME A LITTLE CONCERNED BUT ON THE OTHER SIDE OF THE COIN...KI
IS NOT MUCH LARGER THAN 30-32C IN THE BAND SO AM NOT CONVINCED THAT
THE SPC WRF VIGOR WILL BE REALIZED. NEVERTHELESS...THIS MODEL HAS
GARNERED MY RESPECT SINCE ITS GENERALLY A SUCCESSFUL SIMULATOR OF
THE FUTURE REALITY.
SINCE THE NAM SPITS OUT QPF PRIOR TO 18Z...THAT TRIMS ITS BL TEMP AND
2M TEMPS BY 1-3 DEGS AND WE SEE THE DRY RAP MODEL FCSTG LOWER 90S
19Z-22Z FOR S NJ AND THE PHILLY AREA. THAT MIGHT BE 2 DEGS TO HIGH
FOR 15C AT 850 BUT ITS QUITE POSSIBLE THAT 90F WILL OCCUR AND THAT
OUR HEAT WAVE BEGINS AROUND 3-4PM THIS AFTN.
GRADIENT SW WIND GUST 15-20 MPH THIS AFTN. COOLING SEA BREEZES
WILL STRUGGLE TO PENETRATE INLAND IN THIS GRADIENT FLOW BEHIND THE
WFRONT AND EVEN KACY SHOULD REACH 90F WITH ONLY THE NEAREST 3MI OF
THE COAST RECEIVING THE BENEFIT OF COOLING SLY OCEAN BREEZES.
SINCE OUR HI IS BELOW 96. NO HEAT ADVY NOR EXCESSIVE HEAT WATCHES
BUT EMERGENCY MANAGEMENT HAS BEEN BRIEFED ON THE PROBABLE 3-5 DAY
EARLY SEASON HEAT WAVE FOR THE I95 CORRIDOR.
GENERALLY 50 50 BLENDED GFS NAM GUIDANCE BUT USED THE WARMER 2M
TEMPS FROM THE NAM/RGEM AND RAP-RUC TO MODIFY THE PCPN TAINTED NAM
MOS OUTPUT.
PHL AROUND 89 TODAY AND 90-91 IN SNJ EVEN TO KACY AND S DE VCNTY KGED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
THE LAST BAND OF WHATEVER HEAVY CONVECTION IS PRESSED ESEWD FROM
VCNTY KRDG-KTTN AT AROUND 00-01Z AND WEAKEN JUST TO THE N OF KPNE
AND KACY AROUND 03Z. OTRW A WARM SUMMERLIKE NIGHT.
50 50 BLENDED 00Z/29 GFS/NAM GUIDANCE.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
TO START THE LONG TERM, SURFACE HIGH PRESSURE WILL BE FOUND OVER THE
CENTRAL ATLANTIC, EXTENDING ITS INFLUENCE WESTWARD INTO THE MIDDLE
ATLANTIC STATES. MEANWHILE, STRONG MID-LEVEL RIDGING WILL ALSO BE
TAKING HOLD ACROSS THE REGION. THIS LOOKS TO BE THE BEGINNING OF OUR
FIRST POTENTIAL HEAT WAVE OF THE SEASON, AS A STRENGTHENING
SOUTHWESTERLY FLOW THROUGH THE END OF THE WORK WEEK AND INTO THE
WEEKEND WILL BRING INCREASING HEAT AND HUMIDITY. MODEL 850MB AND
925MB TEMPS SUPPORT MAXIMUM TEMPERATURES EASILY REACHING THE UPPER
80S TO LOWER 90S ACROSS MOST OF THE FORECAST AREA, WITH DEWPOINTS
CLIMBING INTO THE LOWER AND MIDDLE 60S. WE WILL CONTINUE A MENTION
OF THIS EXPECTED HEAT WAVE IN OUR HAZARDOUS WEATHER OUTLOOK, AS HEAT
INDEX VALUES LOOK TO RANGE BETWEEN 90 TO 95 DEGREES.
FOR THE LATTER PART OF THE WEEKEND INTO SUNDAY, THE SURFACE HIGH
PRESSURE AND THE MID-LEVEL RIDGE WILL BOTH BEGIN TO SHIFT EASTWARD,
AS LOW PRESSURE TAKES SHAPE AROUND THE GREAT LAKES WITH A TRAILING
COLD FRONT. WITH THE OVERALL PATTERN BEGINNING TO BREAK DOWN, MODEL
RELATIVE HUMIDITIES INDICATE INCREASING MOISTURE AND CLOUDINESS FOR
SUNDAY, WITH MAXIMUM TEMPERATURES MOSTLY IN THE MIDDLE TO UPPER 80S
ACROSS THE REGION. WE HAVE RETAINED INCREASING POPS FOR
SHWRS/T-STORMS FROM WEST TO EAST ACROSS THE FORECAST AREA DURING
SUNDAY AND SUNDAY NIGHT AS THERE LOOKS TO BE AMPLE INSTABILITY AHEAD
OF THE APPROACHING FRONT. MOST OF THE MODEL GUIDANCE HAS THE COLD
FRONT PASSING THROUGH THE REGION DURING MONDAY, ALTHOUGH THERE ARE
TIMING DIFFERENCES BETWEEN THE GFS, ECMWF, AND OTHERS. AT THIS
EXTENDED TIME RANGE, WE USED A BLEND OF WPC GUIDANCE WITH CONTINUITY
FOR MOST ELEMENTS, INCLUDING TEMPERATURES AND WINDS, AND WE KEPT
HIGH CHANCE POPS IN PLACE ACROSS THE REGION THROUGH MOST OF MONDAY.
WHILE THE FINER DETAILS WILL BE WORKED OUT AS WE GET CLOSER IN TIME
TO THE FRONTAL PASSAGE AND THE MODELS ALIGN MORE WITH REGARDS TO THE
TIMING OF THE FRONT, WHAT IS APPARENT IS THAT TEMPERATURES WILL
RETURN CLOSER TO SEASONAL AVERAGES FOR MONDAY AND TUESDAY.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THROUGH 12Z...IFR/LIFR CONDS IN ST/FOG MUCH OF E PA AND NNJ WITH
ISOLATED SHOWERS AND CALM WIND. FOR FAR S NJ AND DE...GENERALLY
OCNL MVFR VSBY IN FOG WITH S WIND.
AFTER 12Z...ANY REMAINING IFR/LIFR FOG/STRATUS QUICKLY DISSIPATES
BY 13Z AND BECOMES VFR SCT-BKN AOA 5000 FT WITH A SW WIND G15 KT
IN THE AFTN. TWO BANDS OF TSTMS ARE MODELED BY THE SPCWRF AS DISCUSSED
IN DETAIL IN OUR NEAR TERM SECTION. HAVE FOLLOWED THIS FOR THE 06Z
TAFS WITH SUPPORT FROM THE LATEST RAPRUC. IF THESE BANDS...ESPECIALLY
THE NRN PA-NNJ BAND DEVELOP...EXPECT A BRIEF 35-40 KT GUSTY NW
OUTFLOW FROM THE STORMS.
TONIGHT...A LINE OF DYING SHOWERS AND EMBEDDED TSTMS MAY SLIDE
ESEWD FROM VCNTY KRDG-KTTN AROUND 00Z DYING OUT NEAR KPNE-KACY
AROUND 03Z. OTRW VFR WITH POSSIBLE MVFR HAZE FOG TOWARD DAWN
THURSDAY.
OUTLOOK...
THURSDAY THROUGH SATURDAY...MAINLY VFR CONDITIONS EXPECTED WITH
SOUTHWESTERLY WINDS. SOME LOCAL REDUCED VSBYS POSSIBLE EACH MORNING
IN HAZE.
SUNDAY...MAINLY VFR CONDITIONS THROUGH THE DAY, WITH SUB-VFR
CONDITIONS POSSIBLE IN SHWRS/T-STORMS BY LATE-DAY AND INTO SUNDAY
NIGHT.
&&
.MARINE...
SEAS AND WINDS WERE FCST MUCH TOO HIGH ON THE ATLC WATERS TUE AFTN
AND 44009..WITH ITS WIND DATA PROBLEMS AND ALL..STILL BARELY JUST
MADE IT 5 FT AT 11PM EDT AND NOW AROUND 4FT. WILL DISCONTINUE THE
SCA FOR THE SNJ AND DE WATERS PROBABLY AT 6 AM IF NOT SOONER.
OTRW A GENERALLY SSW 10-20 KT FLOW PREVAILS TODAY AND TONIGHT WITH
NO HEADLINE. A BIT OF VSBY RESTRICTION IN FOG AND HAZE TIL 9 AM
EDT AND POSSIBLY IN HAZE EARLY THURSDAY MORNING. WINDS WILL PROBABLY
TURN SSE ALONG THE COASTS FOR A TIME THIS AFTN BUT EVEN THERE..THE
WSW GRADIENT FLOW MAY PREVENT MUCH OF AN EAST OF SOUTH TURN.
OUTLOOK...
WITH OFFSHORE HIGH PRESSURE INFLUENCING THE MID ATLANTIC REGION AND
OUR WATERS, SUB-SCA CONDITIONS ARE EXPECTED ON OUR WATERS FROM
THURSDAY THROUGH THE FIRST PART OF THE WEEKEND. WINDS THROUGH THIS
TIME FRAME WILL MAINLY BE OUT OF THE SOUTHWEST, WITH SEAS IN THE 3
TO 4 FOOT RANGE FOR OUR COASTAL WATERS AND 1 TO 3 FOOT SEAS IN
DELAWARE BAY. GOING INTO SUNDAY WITH HIGH PRESSURE DRIFTING FARTHER
EAST INTO THE CENTRAL ATLANTIC AND A COLD FRONT APPROACHING THE
REGION FROM THE WEST, WE EXPECT WIND GUSTS AND SEAS TO REACH SMALL
CRAFT ADVISORY LEVELS.
&&
.RIP CURRENTS...
RIP CURRENT AWARENESS WEEK JUNE 2 THROUGH 8.
PSA`S WILL AIR ON KPHI NWR AND POST DAILY AROUND 545 AM. A SHORT
AWARENESS PRESS CONFERENCE IN SURF CITY - LBI, TUE JUNE 4 2PM FOR
THOSE MEDIA REPRESENTATIVES THAT ARE INTERESTED IN RAISING RIP
CURRENT AWARENESS AND CONDITIONS FAVORING UNGUARDED LIFE THREATENING
DANGER IN THE OCEAN SURF ZONE.
MORE ON THIS IN THE AFD NEXT MONDAY JUNE 3.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...DENSE FOG ADVISORY UNTIL 7 AM EDT THIS MORNING FOR PAZ054-055-
060>062-071-101>106.
NJ...DENSE FOG ADVISORY UNTIL 7 AM EDT THIS MORNING FOR NJZ007>010-
015-019.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KLINE
NEAR TERM...DRAG
SHORT TERM...DRAG
LONG TERM...KLINE
AVIATION...DRAG/KLINE
MARINE...DRAG/KLINE
RIP CURRENTS...DRAG
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
210 AM EDT WED MAY 29 2013
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTHEAST OF OUR REGION AROUND DAYBREAK.
THEREAFTER...HIGH PRESSURE WILL BE RIDGED FROM THE CENTRAL ATLANTIC
TO THE CAROLINAS LATER TODAY THROUGH THE WEEKEND PROVIDING A PROBABLE
EARLY SEASON HEAT WAVE OF 3 TO 5 DAYS. A LOW PRESSURE SYSTEM OVER
THE GREAT LAKES SUNDAY WILL MOVE TO QUEBEC WITH ITS COLD FRONT
TRAILING SOUTHWARD ALONG THE EAST COAST EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
A WARM FRONT IS DRAPED ACROSS SOUTHERN NEW JERSEY AND NORTH/CENTRAL
DELMARVA EARLY THIS MORNING. NORTH OF THE BOUNDARY, LOW CLOUDS AND
DENSE FOG WILL PERSIST, WHILE SOUTH OF THE FRONT, WE DO NOT EXPECT
FOG TO DEVELOP UNTIL OVERNIGHT.
SHOWERS DIMINISHING IN THEIR EASTWARD PROGRESS ACROSS N PA AT THE
VERY WORST WILL JUST SKIM MOUNT POCONO AND HIGH POINT BETWEEN 3 AM
AND 6 AM.
THE PAST TWO CYCLES OF THE SPCWRF HAD WHAT I THOUGHT WERE EXCELLENT
HOURLY RADAR SIMULATIONS OF WHAT HAS TRANSPIRED FROM LERIE TO THE
DELMARVA INCLUDING OUR FORECAST AREA. THAT SPCWRF IS RELIED ON
HEAVILY AGAIN FOR THE UPCOMING FORECAST FOR TODAY AND TONIGHT.
TODAY...THE 00Z/29 VERSION OF THE SPCWRF IS MORE VIGOROUS ACROSS
OUR AREA THIS AFTN/EVENING THAN I ANTICIPATED. STILL NOT QUITE
SURE IF TWO BANDS OF DECENT CONVECTION CAN DEVELOP SEWD ACROSS
OUR FCST AREA...THE FIRST FROM KDCA-KBLM AROUND 21Z AND WEAKENING
ESEWD OVER FAR SNJ NEAR SUNSET.
THE MORE SIGNIFICANT BAND OF STRONG STORMS WILL PROBABLY DEVELOP
NEAR THE NY/PA BORDER MID AFTN AND ORGANIZE ESEWD TO NEAR I80 BY
AROUND 8 PM EDT. GFS ML CAPE WILL RISE TO NEAR 1500J ALONG I95 THIS
AFTN. THIS SUPPLIES DECENT ENERGY FOR CONVECTION PROVIDED ITS NOT
TOO DRY ALOFT AND THAT THERE CAN BE SOME SORT OF BOUNDARY TRIGGERING
AND ORGANIZING THE CONVECTION.
NOT MUCH 0-6KM BULK SHEAR SUPPORT FOR SVR WIND IN OUR AREA BUT A
GUSTY NW WIND OUTFLOW OF 35-40 KT IS POSSIBLE FROM KMPO TO KFWN
AND POSSIBLY DOWN TO KRDG/KABE AND KTTN. ADDITIONALLY TT UP AROUND
50C HAS ME A LITTLE CONCERNED BUT ON THE OTHER SIDE OF THE COIN...KI
IS NOT MUCH LARGER THAN 30-32C IN THE BAND SO AM NOT CONVINCED THAT
THE SPC WRF VIGOR WILL BE REALIZED. NEVERTHELESS...THIS MODEL HAS
GARNERED MY RESPECT SINCE ITS GENERALLY A SUCCESSFUL SIMULATOR OF
THE FUTURE REALITY.
SINCE THE NAM SPITS OUT QPF PRIOR TO 18Z...THAT TRIMS ITS BL TEMP AND
2M TEMPS BY 1-3 DEGS AND WE SEE THE DRY RAP MODEL FCSTG LOWER 90S
19Z-22Z FOR S NJ AND THE PHILLY AREA. THAT MIGHT BE 2 DEGS TO HIGH
FOR 15C AT 850 BUT ITS QUITE POSSIBLE THAT 90F WILL OCCUR AND THAT
OUR HEAT WAVE BEGINS AROUND 3-4PM THIS AFTN.
GRADIENT SW WIND GUST 15-20 MPH THIS AFTN. COOLING SEA BREEZES
WILL STRUGGLE TO PENETRATE INLAND IN THIS GRADIENT FLOW BEHIND THE
WFRONT AND EVEN KACY SHOULD REACH 90F WITH ONLY THE NEAREST 3MI OF
THE COAST RECEIVING THE BENEFIT OF COOLING SLY OCEAN BREEZES.
SINCE OUR HI IS BELOW 96. NO HEAT ADVY NOR EXCESSIVE HEAT WATCHES
BUT EMERGENCY MANAGEMENT HAS BEEN BRIEFED ON THE PROBABLE 3-5 DAY
EARLY SEASON HEAT WAVE FOR THE I95 CORRIDOR.
GENERALLY 50 50 BLENDED GFS NAM GUIDANCE BUT USED THE WARMER 2M
TEMPS FROM THE NAM/RGEM AND RAP-RUC TO MODIFY THE PCPN TAINTED NAM
MOS OUTPUT.
PHL AROUND 89 TODAY AND 90-91 IN SNJ EVEN TO KACY AND S DE VCNTY KGED.
&&
.SHORT TERM /TONIGHT/...
THE LAST BAND OF WHATEVER HEAVY CONVECTION IS PRESSED ESEWD FROM
VCNTY KRDG-KTTN AT AROUND 00-01Z AND WEAKEN JUST TO THE N OF KPNE
AND KACY AROUND 03Z. OTRW A WARM SUMMERLIKE NIGHT.
50 50 BLENDED 00Z/29 GFS/NAM GUIDANCE.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
5-WAVE MODEL GUIDANCE SHOWS A RATHER LARGE BERMUDA RIDGE SETTING UP
THROUGH THE END OF THE WEEKEND WITH WEAK UPSTREAM TROUGHING. THE
RIDGE LOOKS TO AMPLIFY TOWARDS THE END OF THE WEEK BEFORE SHIFTING
MORE TOWARDS THE EAST-NORTHEAST. THE LONGWAVE TROUGH WILL BEGIN TO
FILL BACK IN BEHIND THE DEPARTING RIDGE BY EARLY NEXT WEEK.
WITH THE WARM FRONT PROGRESSING TO OUR NORTHEAST ON THURSDAY MORNING
AND WINDS BEGINNING TO BACK, WE SHOULD BE DRYING OUT THE COLUMN SOME
ALOFT. WITH VERY LITTLE IN THE WAY OF UPPER LEVEL SUPPORT AND
SURFACE RIDGING JUST TO OUR EAST WE KEEP THE FORECAST THROUGH THE
FIRST PART OF THE LONGTERM FAIRLY DRY. AN ENSUING VERY HOT AND HUMID
AIRMASS WILL MOVE IN STARTING ON THURSDAY WHICH LOOKS TO COMMENCE
OUR FIRST HEAT WAVE OF THE SEASON. SURFACE DEWPOINTS WILL CLIMB INTO
THE LOW TO MID-60S DURING THE HEAT WAVE UNDER AN INCREASING
SOUTHWESTERLY FLOW. THIS WOULD LEAD TO HEAT INDEX VALUES INTO THE
LOW-90S..CLOSER TO THE ACTUAL TEMPERATURES...NO HEAT RELATED
HEADLINES NEEDED THUS FAR. CLOSER TO THE COAST IT LOOKS DOUBTFUL
THAT A SEABREEZE WILL BE ABLE TO BRING ANY RELIEF THIS WEEKEND (IF
THAT IS WHAT YOU ARE LOOKING FOR) GIVEN THE STRONGER LOW-LEVEL
SOUTHWESTERLY FLOW.
THE MID-LEVEL RIDGING WILL BEGIN TO SLIDE MORE TOWARDS THE EAST ON
SATURDAY ALLOWING OUR REGION TO BE ON THE PERIPHERY OF ITS
INFLUENCE. THIS WOULD PLACE US WITHIN THE RING OF FIRE TERRITORY
WHERE ANY PIECE OF ENERGY COULD EASILY INITIATE CONVECTION. THERE
LOOKS TO BE A WEAK LEE-SIDE TROUGH THAT WILL TRY TO PUSH INTO THE
REGION ON SATURDAY FROM THE WEST-SOUTHWEST BUT THE COLUMN LOOKS
RATHER DRY, EXCEPT FOR THE SURFACE LAYER. PWATS WILL BE AROUND 1.25
INCHES, RATHER NORMAL GIVEN THE TIME OF THE YEAR. GIVEN THAT WE
SHOULD BE AMPLY UNSTABLE WITH SOME WEAK DYNAMICS FURTHER NORTH WE
ONLY HAVE A SLIGHT CHANCE ACROSS THIS REGION ON SATURDAY EVENING.
AFTER A HOT SATURDAY LOWS SATURDAY NIGHT WILL STRUGGLE TO FALL
INTO THE 60`S IN SPOTS. A FRONTAL BOUNDARY WILL MOVE INTO THE
REGION SUNDAY AND MONDAY. THIS WILL INCREASE CLOUDS SUNDAY AND
KEEP TEMPERATURES BELOW THE 90 DEGREE MARK DURING THE DAY SUNDAY.
ENOUGH INSTABILITY WILL IN PLACE DURING THE AFTERNOON FOR A FEW
STORMS TO FIRE PARTICULARLY WEST OF PHILLY CLOSER TO THE FRONT
DURING THE AFTERNOON. GOOD OVERALL GUIDANCE AGREEMENT WITH MOST WX
ELEMENTS THROUGH SUNDAY.
RAIN CHANCES INCREASE WITH THE FRONTAL PASSAGE LATE SUNDAY NIGHT AND
MONDAY. ENSEMBLES BOTH GFS AND ECMWF SHOW THE FRONTAL PASSAGE DURING
THIS TIME FRAME WITH SOME VARIABILITY IN EXACTLY WHEN THE FRONT
PASSES THROUGH. ALSO THINKING MODELING COULD BE EITHER SLIGHTLY FASTER OR
SLOWER IN FUTURE RUNS. THIS PRECLUDES LIKELY POPS FROM THE FORECAST
ATTM. SHOWERS AND THUNDERSTORMS ARE EXPECTED WITH THE FRONTAL
PASSAGE. FRONTAL TIMING WILL ALSO CONTRIBUTE TO THE AMOUNT OF
INSTABILITY AND ANY THREAT FOR STRONG STORMS OR HEAVY RAINFALL. THIS
FRONTAL BOUNDARY WILL END THE HEAT WAVE WITH MORE SEASONABLE AIR
BEHIND THE FRONT. HIGH TEMPERATURES MONDAY AND THE WIND DIRECTION
WILL ALSO BE BOTH HIGHLY DEPENDENT ON FRONTAL TIMING. FOR NOW MAINLY
BASED TIMING OF EVENTS ALONG THE LINES OF THE WPC GUIDANCE WHICH MATCH
WELL WITH THE ENSEMBLE APPROACH TAKEN WITH THIS PART OF THE
FORECAST. SKIES WILL CLEAR OUT GRADUALLY TUESDAY. HAVE GRADUALLY
DECREASED SKY COVER AND CLOUDS ON THE DAY TUESDAY ACROSS THE
REGION.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THROUGH 12Z...IFR/LIFR CONDS IN ST/FOG MUCH OF E PA AND NNJ WITH
ISOLATED SHOWERS AND CALM WIND. FOR FAR S NJ AND DE...GENERALLY
OCNL MVFR VSBY IN FOG WITH S WIND.
AFTER 12Z...ANY REMAINING IFR/LIFR FOG/STRATUS QUICKLY DISSIPATES
BY 13Z AND BECOMES VFR SCT-BKN AOA 5000 FT WITH A SW WIND G15 KT
IN THE AFTN. TWO BANDS OF TSTMS ARE MODELED BY THE SPCWRF AS DISCUSSED
IN DETAIL IN OUR NEAR TERM SECTION. HAVE FOLLOWED THIS FOR THE 06Z
TAFS WITH SUPPORT FROM THE LATEST RAPRUC. IF THESE BANDS...ESPECIALLY
THE NRN PA-NNJ BAND DEVELOP...EXPECT A BRIEF 35-40 KT GUSTY NW
OUTFLOW FROM THE STORMS.
TONIGHT...A LINE OF DYING SHOWERS AND EMBEDDED TSTMS MAY SLIDE
ESEWD FROM VCNTY KRDG-KTTN AROUND 00Z DYING OUT NEAR KPNE-KACY
AROUND 03Z. OTRW VFR WITH POSSIBLE MVFR HAZE FOG TOWARD DAWN
THURSDAY.
OUTLOOK...
THURSDAY - SATURDAY...VFR WITH SOUTHWESTERLY WINDS. POSSIBLE EARLY
MORNING HAZE MVFR VSBYS EACH MORNING.
SUNDAY...MAINLY VFR, ISOLATED THUNDERSTORMS LATE FOR PHL AND
POINTS NW. LOCALLY IFR TO MVFR IN ANY THUNDERSTORMS.
&&
.MARINE...
SEAS AND WINDS WERE FCST MUCH TOO HIGH ON THE ATLC WATERS TUE AFTN
AND 44009..WITH ITS WIND DATA PROBLEMS AND ALL..STILL BARELY JUST
MADE IT 5 FT AT 11PM EDT AND NOW AROUND 4FT. WILL DISCONTINUE THE
SCA FOR THE SNJ AND DE WATERS PROBABLY AT 6 AM IF NOT SOONER.
OTRW A GENERALLY SSW 10-20 KT FLOW PREVAILS TODAY AND TONIGHT WITH
NO HEADLINE. A BIT OF VSBY RESTRICTION IN FOG AND HAZE TIL 9 AM
EDT AND POSSIBLY IN HAZE EARLY THURSDAY MORNING. WINDS WILL PROBABLY
TURN SSE ALONG THE COASTS FOR A TIME THIS AFTN BUT EVEN THERE..THE
WSW GRADIENT FLOW MAY PREVENT MUCH OF AN EAST OF SOUTH TURN.
OUTLOOK...
SUB-ADVISORY CONDITIONS IN STORE FOR OUR WATERS THROUGH A GOOD
PORTION OF THE OUTLOOK PERIOD. WINDS WILL GENERALLY BE FROM THE
SOUTH-SOUTHWEST BY THURSDAY AS HIGH PRESSURE, OFFSHORE, WILL
DOMINATE OUR SENSIBLE WEATHER. SEAS WILL GENERALLY BE AROUND 3
FEET ACROSS ALL THE WATERS. SEAS AND WINDS WILL BEGIN TO INCREASE
THROUGHOUT THE DAY ON SUNDAY AND MONDAY AND LOOK TO REACH SCA
CRITERIA.
&&
.RIP CURRENTS...
RIP CURRENT AWARENESS WEEK JUNE 2 THROUGH 8.
PSA`S WILL AIR ON KPHI NWR AND POST DAILY AROUND 545 AM. A SHORT
AWARENESS PRESS CONFERENCE IN SURF CITY - LBI, TUE JUNE 4 2PM FOR
THOSE MEDIA REPRESENTATIVES THAT ARE INTERESTED IN RAISING RIP
CURRENT AWARENESS AND CONDITIONS FAVORING UNGUARDED LIFE THREATENING
DANGER IN THE OCEAN SURF ZONE.
MORE ON THIS IN THE AFD NEXT MONDAY JUNE 3.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR
ANZ453>455.
&&
$$
SYNOPSIS...DRAG/HEAVENER 0608Z
NEAR TERM...DRAG 0608Z
SHORT TERM...DRAG 0608Z
LONG TERM...GAINES/HEAVENER
AVIATION...DRAG/HEAVENER 0608Z
MARINE...DRAG/HEAVENER 0608Z
RIP CURRENTS...0608Z
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
322 AM EDT Wed May 29 2013
.NEAR TERM [Through Tonight]...
At upper levels, we see a trough over the central part of the nation
and a ridge over much of the Southeast. Surface analysis continues
to show a ridge axis extending from off the Carolina coast westward
to Louisiana. We have seen a very gradual moistening of the lower
levels over the past few days with some isolated showers over the
Gulf of Mexico and also just west of the forecast area. We believe
we will see some mainly isolated shower and thunderstorm development
this afternoon across the CWA triggered mainly be the sea breeze.
The only area with scattered PoPs will be the Suwannee Valley area
where the east-southeast synoptic flow should enhance convergence
along the sea breeze front. We have continued the recent trend of
going a degree or two above a guidance blend for max temps. Some
guidance members indicate the chance for some fog over our South
Central GA and eastern FL Big Bend zones overnight. Min temps will
be a few degrees above normal, generally ranging from the upper 60s
north to the lower 70s for the coastal zones.
&&
.SHORT TERM [Thursday Through Friday]...
Upper level ridging will continue to persist across the eastern
one-third of the CONUS through the short term period, with the
center of a 1025-1030mb surface ridge lingering to the east of the
Carolinas. This ridging will extend eastward into the north-central
Gulf of Mexico and provide at least moderate east to southeast low
level winds over the interior, with gradually increasing deep layer
moisture, with PWATs eventually climbing into the 1.50 to 1.75 inch
range by late Thursday and Friday. This will allow the Sea Breeze
Front to become a bit more convectively active over the next couple
of days, but the limited CAPE in the forecast soundings and the
fairly strong 1000-700mb Mean Layer Vector Wind (MLVW) out of the
southeast at 15 to 20 kts will keep the convection fairly weak.
Afternoon PoPs are expected to range between 20 and 30 percent
across much of the interior, with the best chances for afternoon
showers and thunderstorms over SE AL on Thursday, and SE AL and the
FL Panhandle on Friday. High temps are still expected to be quite
warm and just a bit above climo, with topping out in the mid 80s
near the coast to the lower 90s further inland, with overnight lows
moderating into the upper 60s to the lower 70s.
&&
.LONG TERM [Friday Night through Tuesday]...
A broad area of high pressure over the Southeast US and Atlantic
Ocean will remain in place from Thursday through the weekend,
resulting in easterly flow and lower than normal chances of
precipitation. The best chance at seeing isolated thunderstorms will
be in the eastern part of our CWA during this period, where the
Atlantic sea breeze may spark some convection each afternoon and
early evening as it collides with the Gulf sea breeze. Seasonable
temperatures should occur throughout the period, with highs
generally in the low 90s and lows in the mid-upper 60s. Looking
ahead to next week, a disturbance in the southern Gulf and Caribbean
is being shown by the GFS, but it is far too early to determine the
track or intensity of this possible feature.
&&
.AVIATION
[Through 06 UTC Thursday] The NARRE and HRRR guidance supports the
gridded LAMP and MOS in showing from low ceilings developing over
the eastern terminals. We show a few hours of IFR at VLD and TLH.
Visibility restrictions are not anticipated as surface winds are
forecast to remain around 4-7 kt through the night. Shower and
thunderstorm development is expected to be isolated this afternoon
and we only mention a vicinity shower at TLH and VLD.
&&
.MARINE...
More of the same is expected across our Coastal Waters, as the ridge
of high pressure to the east of the Carolinas will continue to
provide very favorable conditions for mostly nocturnal wind surges
out of the east and southeast for the next few days. These surges
will bring wind speeds into the Cautionary range and close to Small
Craft Advisory range during the late night and morning hours into
Friday, before the pressure pattern begins to weaken and break down
by the upcoming weekend.
&&
.FIRE WEATHER...
There are no concerns about red flag criteria due to sufficiently
high RH over the next several days. However, dispersion indices will
be elevated, over 75 in many areas on Thursday.
&&
.HYDROLOGY...
With only isolated to scattered showers and thunderstorms expected
over the next several days, no significant impacts are anticipated
on our area rivers.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 91 70 91 70 91 / 20 10 20 20 20
Panama City 87 72 84 73 86 / 20 10 20 20 20
Dothan 92 69 91 69 92 / 20 10 30 10 30
Albany 92 68 91 68 91 / 10 10 10 10 20
Valdosta 90 67 92 67 92 / 20 10 10 10 20
Cross City 92 67 92 68 91 / 30 10 20 10 20
Apalachicola 86 73 83 73 85 / 10 10 20 20 20
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...Wool
SHORT TERM...Gould
LONG TERM...Godsey
AVIATION...Wool
MARINE...Gould
FIRE WEATHER...Wool
HYDROLOGY...Gould
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
250 PM EDT WED MAY 29 2013
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
CURRENT SATELLITE LOOP SHOWS BKN TO OVC ACROSS THE AREA WITH THE
CLOUDS ROTATING AROUND THE HIGH PRESSURE RIDGE. THE SURFACE AND UPPER
LEVEL RIDGES ARE ALMOST VERTICALLY STACKED WHICH IS DOING A VERY GOOD
JOB OF KEEPING ANY CU DEVELOPMENT FROM BECOMING A SHOWER/THUNDERSTORM.
EVEN WITH THE GOOD MOIST EASTERLY FLOW THIS RIDGE SHOULD KEEP UP
PRECIPITATION FREE THROUGH THE SHORT TERM. A FEW OF OUR LOCAL
MODELS...THE HRRR AND THE LOCAL WRF...ARE TRYING TO SHOW SOME
SHOWERS DEVELOPING THIS AFTERNOON ACROSS OUR SOUTHEASTERN COUNTIES.
BOTH OF THESE MODELS APPEAR TO BE PICKING UP ON WHAT LOOKS TO BE A
SEA BREEZE FRONT AND BRINGS IN SO LIGHT SHOWERS THIS AFTERNOON. THE
RIDGE IS FIRMLY ENTRENCHED ACROSS SE GA SO I WOULD TEND TO RULE OUT
ANY PRECIP TODAY OR THURSDAY. FOR NOW AM KEEPING ANY PRECIP WORDING
OUT WITH POPS REMAINING BELOW 15 PERCENT. WITH THE MOIST EASTERLY
FLOW WE WILL SEE INCREASED CLOUD COVER AGAIN THURSDAY WITH SOME LOW
STRATUS MOVING IN TONIGHT. THESE LOW CLOUDS WILL KEEP TEMPS UP A
LITTLE HIGHER THAN THE PAST COUPLE OF NIGHTS WITH MAX TEMPS THROUGH
THURSDAY STAY IN THE 80S AND 90S.
01
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
MAINLY ONLY TWEAKS TO THE LONG TERM. CAN NOT COMPLETELY RULE OUT
SMALL CHANCES FOR SHOWERS/STORMS FRIDAY AFTERNOON OVER THE WESTERN CWA
AND SATURDAY AFTERNOON FOR MUCH OF N AND CENTRAL GA. SHOWERS AND
STORMS STILL MOST LIKELY SUNDAY AND MONDAY.
BDL
PREVIOUS DISCUSSION...
ECMWF AND GFS IN GOOD AGREEMENT INTO THE WEEKEND WITH DIFFERENCES
DEVELOPING AT THE EARLY PART OF NEXT WEEK. THE H5 RIDGE MAINTAINS
ITS HOLD OVER THE CWA THROUGH FRIDAY...THEN THE RIDGE BEGINS TO
BREAK DOWN AS THE UPPER TROUGH MOVES INTO THE MIDWEST. THIS WILL
DRIVE A COLD FRONT INTO THE TENNESSEE AND OHIO VALLEYS LATE SATURDAY
AND INTO SUNDAY AND MONDAY. THE ECMWF IS A LITTLE FASTER AND BRINGS
MOISTURE WITH THE FRONT INTO THE CWA LATE SATURDAY NIGHT. BOTH
MODELS PROG THE FRONT TO TAP INTO GULF MOISTURE SUNDAY BRINGING A
GOOD CHANCE OF PRECIP TO MUCH OF THE CWA. DIFFERENCES DEVELOP SUNDAY
NIGHT/MONDAY ON THE SPEED OF EXITING THE FRONT AND ASSOCIATED
MOISTURE. THE ECMWF PUSHES THE FRONT THROUGH BUT THE SOUTHEAST
CORNER OF THE CWA BY 12Z MONDAY WHILE THE GFS HOLDS THE FRONT BACK
CLEARING ONLY THE NORTHWEST PART OF THE CWA BY 12Z MON AND THEN
DEVELOPS A SECONDARY UPPER WAVE THAT INCREASES MOISTURE OVER MOST OF
THE CWA DURING THE DAY MONDAY. AT THIS POINT WILL MAINTAIN HIGH POPS
SUNDAY AND MONDAY AND BRING LOW OR NO POPS ON TUESDAY.
17
&&
.AVIATION...
18Z UPDATE...
WITH GOOD MOIST EASTERLY FLOW ACROSS THE AREA...SEEING MOSTLY
CLOUDY SKIES WITH CEILINGS IN THE SCT-BKN 3000-4000FT LEVEL.
CEILINGS ARE SLOWLY LIFTING AND SHOULD GET UP INTO THE 5000-6000FT
RANGE. WITH THE HIGH PRESSURE RIDGE STILL OVER THE STATE NO
PRECIPITATION OR RESTRICTION TO VSBYS IS EXPECT. WINDS WILL ALSO
STY OUT OF THE E TO SE IN THE 5-10KT RANGE.
//ATL CONFIDENCE...18Z UPDATE...
CONFIDENCE HIGH ON ALL ELEMENTS
01
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 64 87 66 85 / 5 5 5 10
ATLANTA 67 85 66 85 / 5 5 5 10
BLAIRSVILLE 60 83 63 82 / 5 5 5 10
CARTERSVILLE 65 86 66 85 / 5 5 10 20
COLUMBUS 68 88 68 89 / 10 10 10 20
GAINESVILLE 65 83 66 83 / 5 5 5 10
MACON 66 88 66 88 / 5 5 5 10
ROME 65 87 66 85 / 5 10 10 30
PEACHTREE CITY 65 86 66 85 / 5 5 5 10
VIDALIA 68 90 67 90 / 5 5 5 10
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...01
LONG TERM....BDL
AVIATION...01
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
149 PM EDT WED MAY 29 2013
.SHORT TERM /TODAY THROUGH THURSDAY/...
SHORT TERM REMAINS QUIET FOR THE MOST PART...WITH RIDGING ALOFT
AND MOIST SOUTHERLY SURFACE FLOW AROUND THE WESTERN PERIPHERY OF A
HIGH IN THE ATLANTIC. A WEAKNESS IN THE FLOW ALOFT OVER THE
BAHAMAS HAS LED TO AN INCREASE IN CONVECTIVE ACTIVITY...AND SOME
MOISTURE FROM THIS SYSTEM IS PROGGED TO MOVE ACROSS FLORIDA TODAY
AND INTO THE DEEP SOUTH TONIGHT. NAM AND SREF BRING SOME PRECIP TO
SOUTHWEST ZONES...BUT ECMWF AND GFS KEEP THE AREA DRY. NAM GOES
GANGBUSTERS WITH THE CAPE...WITH OVER 1500 J/KG ACROSS SOUTHERN
AND WESTERN ZONES...WHEREAS ALL OTHER GUIDANCE KEEPS CAPE VALUES
BELOW ABOUT 800 J/KG. HPC DOES PAINT SOME LIGHT QPF FROM
APPROXIMATELY CARROLLTON TO CORDELE AND POINTS SOUTH AND
WEST...AND LOCAL WRF AND HRRR BOTH TRY TO DEVELOP SOME POP-UP
CONVECTION THIS AFTERNOON BUT KEEP MOST OF THE CONVECTION IN
ALABAMA. FOR NOW HOWEVER AM KEEPING ANY PRECIP WORDING OUT WITH
POPS REMAINING BELOW 15 PERCENT IN THOSE AREAS BUT TRENDS WILL
HAVE TO BE MONITORED. BIGGER IMPACT WILL BE FROM THE STRATUS THAT
IS EXPECTED TO MOVE IN OVERNIGHT AND EARLY THURSDAY... WHICH WILL
KEEP TEMPS UP A LITTLE HIGHER THAN THE PAST COUPLE OF NIGHTS. MAX
TEMPS THROUGH THE SHORT TERM WILL AGAIN BE ON THE WARM SIDE BUT
ONLY A COUPLE OF DEGREES ABOVE SEASONAL NORMALS.
TDP
LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
ECMWF AND GFS IN GOOD AGREEMENT INTO THE WEEKEND WITH DIFFERENCES
DEVELOPING AT THE EARLY PART OF NEXT WEEK. THE H5 RIDGE MAINTAINS
ITS HOLD OVER THE CWA THROUGH FRIDAY...THEN THE RIDGE BEGINS TO
BREAK DOWN AS THE UPPER TROUGH MOVES INTO THE MIDWEST. THIS WILL
DRIVE A COLD FRONT INTO THE TENNESSEE AND OHIO VALLEYS LATE SATURDAY
AND INTO SUNDAY AND MONDAY. THE ECMWF IS A LITTLE FASTER AND BRINGS
MOISTURE WITH THE FRONT INTO THE CWA LATE SATURDAY NIGHT. BOTH
MODELS PROG THE FRONT TO TAP INTO GULF MOISTURE SUNDAY BRINGING A
GOOD CHANCE OF PRECIP TO MUCH OF THE CWA. DIFFERENCES DEVELOP SUNDAY
NIGHT/MONDAY ON THE SPEED OF EXITING THE FRONT AND ASSOCIATED
MOISTURE. THE ECMWF PUSHES THE FRONT THROUGH BUT THE SOUTHEAST
CORNER OF THE CWA BY 12Z MONDAY WHILE THE GFS HOLDS THE FRONT BACK
CLEARING ONLY THE NORTHWEST PART OF THE CWA BY 12Z MON AND THEN
DEVELOPS A SECONDARY UPPER WAVE THAT INCREASES MOISTURE OVER MOST OF
THE CWA DURING THE DAY MONDAY. AT THIS POINT WILL MAINTAIN HIGH POPS
SUNDAY AND MONDAY AND BRING LOW OR NO POPS ON TUESDAY.
17
&&
.AVIATION...
18Z UPDATE...
WITH GOOD MOIST EASTERLY FLOW ACROSS THE AREA...SEEING MOSTLY
CLOUDY SKIES WITH CEILINGS IN THE SCT-BKN 3000-4000FT LEVEL.
CEILINGS ARE SLOWLY LIFTING AND SHOULD GET UP INTO THE 5000-6000FT
RANGE. WITH THE HIGH PRESSURE RIDGE STILL OVER THE STATE NO
PRECIPITATION OR RESTRICTION TO VSBYS IS EXPECT. WINDS WILL ALSO
STY OUT OF THE E TO SE IN THE 5-10KT RANGE.
//ATL CONFIDENCE...18Z UPDATE...
CONFIDENCE HIGH ON ALL ELEMENTS
01
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 85 64 85 66 / 5 5 5 5
ATLANTA 84 67 83 66 / 5 5 5 5
BLAIRSVILLE 81 60 81 63 / 0 5 5 5
CARTERSVILLE 85 65 84 66 / 5 5 5 5
COLUMBUS 88 69 87 69 / 5 10 10 5
GAINESVILLE 82 65 81 66 / 5 5 5 5
MACON 88 66 87 67 / 5 5 5 0
ROME 87 65 85 66 / 5 5 10 10
PEACHTREE CITY 85 65 84 66 / 5 5 5 5
VIDALIA 88 69 89 69 / 5 5 5 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...01
LONG TERM....BDL
AVIATION...01
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
738 AM EDT WED MAY 29 2013
.PREV DISCUSSION... /ISSUED 259 AM EDT WED MAY 29 2013/
SHORT TERM /TODAY THROUGH THURSDAY/...
SHORT TERM REMAINS QUIET FOR THE MOST PART...WITH RIDGING ALOFT AND
MOIST SOUTHERLY SURFACE FLOW AROUND THE WESTERN PERIPHERY OF A HIGH
IN THE ATLANTIC. A WEAKNESS IN THE FLOW ALOFT OVER THE BAHAMAS HAS
LED TO AN INCREASE IN CONVECTIVE ACTIVITY...AND SOME MOISTURE FROM
THIS SYSTEM IS PROGGED TO MOVE ACROSS FLORIDA TODAY AND INTO THE
DEEP SOUTH TONIGHT. NAM AND SREF BRING SOME PRECIP TO SOUTHWEST
ZONES...BUT ECMWF AND GFS KEEP THE AREA DRY. NAM GOES GANGBUSTERS
WITH THE CAPE...WITH OVER 1500 J/KG ACROSS SOUTHERN AND WESTERN
ZONES...WHEREAS ALL OTHER GUIDANCE KEEPS CAPE VALUES BELOW ABOUT 800
J/KG. HPC DOES PAINT SOME LIGHT QPF FROM APPROXIMATELY CARROLLTON TO
CORDELE AND POINTS SOUTH AND WEST...AND LOCAL WRF AND HRRR BOTH TRY
TO DEVELOP SOME POP-UP CONVECTION THIS AFTERNOON BUT KEEP MOST OF
THE CONVECTION IN ALABAMA. FOR NOW HOWEVER AM KEEPING ANY PRECIP
WORDING OUT WITH POPS REMAINING BELOW 15 PERCENT IN THOSE AREAS BUT
TRENDS WILL HAVE TO BE MONITORED. BIGGER IMPACT WILL BE FROM THE
STRATUS THAT IS EXPECTED TO MOVE IN OVERNIGHT AND EARLY THURSDAY...
WHICH WILL KEEP TEMPS UP A LITTLE HIGHER THAN THE PAST COUPLE OF
NIGHTS. MAX TEMPS THROUGH THE SHORT TERM WILL AGAIN BE ON THE WARM
SIDE BUT ONLY A COUPLE OF DEGREES ABOVE SEASONAL NORMALS.
TDP
LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
ECMWF AND GFS IN GOOD AGREEMENT INTO THE WEEKEND WITH DIFFERENCES
DEVELOPING AT THE EARLY PART OF NEXT WEEK. THE H5 RIDGE MAINTAINS
ITS HOLD OVER THE CWA THROUGH FRIDAY...THEN THE RIDGE BEGINS TO
BREAK DOWN AS THE UPPER TROUGH MOVES INTO THE MIDWEST. THIS WILL
DRIVE A COLD FRONT INTO THE TENNESSEE AND OHIO VALLEYS LATE SATURDAY
AND INTO SUNDAY AND MONDAY. THE ECMWF IS A LITTLE FASTER AND BRINGS
MOISTURE WITH THE FRONT INTO THE CWA LATE SATURDAY NIGHT. BOTH
MODELS PROG THE FRONT TO TAP INTO GULF MOISTURE SUNDAY BRINGING A
GOOD CHANCE OF PRECIP TO MUCH OF THE CWA. DIFFERENCES DEVELOP SUNDAY
NIGHT/MONDAY ON THE SPEED OF EXITING THE FRONT AND ASSOCIATED
MOISTURE. THE ECMWF PUSHES THE FRONT THROUGH BUT THE SOUTHEAST
CORNER OF THE CWA BY 12Z MONDAY WHILE THE GFS HOLDS THE FRONT BACK
CLEARING ONLY THE NORTHWEST PART OF THE CWA BY 12Z MON AND THEN
DEVELOPS A SECONDARY UPPER WAVE THAT INCREASES MOISTURE OVER MOST OF
THE CWA DURING THE DAY MONDAY. AT THIS POINT WILL MAINTAIN HIGH POPS
SUNDAY AND MONDAY AND BRING LOW OR NO POPS ON TUESDAY.
17
&&
.AVIATION...
12Z UPDATE...
LARGE AREA OF LOW MVFR CIGS DID MANAGE TO DEVELOP NEAR MCN AND
SPREAD NORTH OVER THE PAST FEW HOURS...JUST NOW REACHING TO ATL.
WILL CARRY THIS FOR ANOTHER HOUR OR SO...OTHERWISE...VFR CIGS
THROUGH THE AFTERNOON AND EVENING WITH SE WINDS GENERALLY 5-10KT.
INCREASING MOISTURE THURSDAY MORNING SHOULD BRING MVFR TO
POTENTIALLY IFR CIGS EVERYWHERE BETWEEN 08-10Z.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM ON TIMING OF CIGS THIS MORNING AND TOMORROW MORNING.
HIGH ON ALL OTHER ELEMENTS.
TDP
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 85 64 85 66 / 5 5 5 5
ATLANTA 84 67 83 66 / 5 5 5 5
BLAIRSVILLE 81 60 81 63 / 0 5 5 5
CARTERSVILLE 85 65 84 66 / 5 5 5 5
COLUMBUS 88 69 87 69 / 5 10 10 5
GAINESVILLE 82 65 81 66 / 5 5 5 5
MACON 88 66 87 67 / 5 5 5 0
ROME 87 65 85 66 / 5 5 10 10
PEACHTREE CITY 85 65 84 66 / 5 5 5 5
VIDALIA 88 69 89 69 / 5 5 5 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
259 AM EDT WED MAY 29 2013
.SHORT TERM /TODAY THROUGH THURSDAY/...
SHORT TERM REMAINS QUIET FOR THE MOST PART...WITH RIDGING ALOFT AND
MOIST SOUTHERLY SURFACE FLOW AROUND THE WESTERN PERIPHERY OF A HIGH
IN THE ATLANTIC. A WEAKNESS IN THE FLOW ALOFT OVER THE BAHAMAS HAS
LED TO AN INCREASE IN CONVECTIVE ACTIVITY...AND SOME MOISTURE FROM
THIS SYSTEM IS PROGGED TO MOVE ACROSS FLORIDA TODAY AND INTO THE
DEEP SOUTH TONIGHT. NAM AND SREF BRING SOME PRECIP TO SOUTHWEST
ZONES...BUT ECMWF AND GFS KEEP THE AREA DRY. NAM GOES GANGBUSTERS
WITH THE CAPE...WITH OVER 1500 J/KG ACROSS SOUTHERN AND WESTERN
ZONES...WHEREAS ALL OTHER GUIDANCE KEEPS CAPE VALUES BELOW ABOUT 800
J/KG. HPC DOES PAINT SOME LIGHT QPF FROM APPROXIMATELY CARROLLTON TO
CORDELE AND POINTS SOUTH AND WEST...AND LOCAL WRF AND HRRR BOTH TRY
TO DEVELOP SOME POP-UP CONVECTION THIS AFTERNOON BUT KEEP MOST OF
THE CONVECTION IN ALABAMA. FOR NOW HOWEVER AM KEEPING ANY PRECIP
WORDING OUT WITH POPS REMAINING BELOW 15 PERCENT IN THOSE AREAS BUT
TRENDS WILL HAVE TO BE MONITORED. BIGGER IMPACT WILL BE FROM THE
STRATUS THAT IS EXPECTED TO MOVE IN OVERNIGHT AND EARLY THURSDAY...
WHICH WILL KEEP TEMPS UP A LITTLE HIGHER THAN THE PAST COUPLE OF
NIGHTS. MAX TEMPS THROUGH THE SHORT TERM WILL AGAIN BE ON THE WARM
SIDE BUT ONLY A COUPLE OF DEGREES ABOVE SEASONAL NORMALS.
TDP
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
ECMWF AND GFS IN GOOD AGREEMENT INTO THE WEEKEND WITH DIFFERENCES
DEVELOPING AT THE EARLY PART OF NEXT WEEK. THE H5 RIDGE MAINTAINS
ITS HOLD OVER THE CWA THROUGH FRIDAY...THEN THE RIDGE BEGINS TO
BREAK DOWN AS THE UPPER TROUGH MOVES INTO THE MIDWEST. THIS WILL
DRIVE A COLD FRONT INTO THE TENNESSEE AND OHIO VALLEYS LATE SATURDAY
AND INTO SUNDAY AND MONDAY. THE ECMWF IS A LITTLE FASTER AND BRINGS
MOISTURE WITH THE FRONT INTO THE CWA LATE SATURDAY NIGHT. BOTH
MODELS PROG THE FRONT TO TAP INTO GULF MOISTURE SUNDAY BRINGING A
GOOD CHANCE OF PRECIP TO MUCH OF THE CWA. DIFFERENCES DEVELOP SUNDAY
NIGHT/MONDAY ON THE SPEED OF EXITING THE FRONT AND ASSOCIATED
MOISTURE. THE ECMWF PUSHES THE FRONT THROUGH BUT THE SOUTHEAST
CORNER OF THE CWA BY 12Z MONDAY WHILE THE GFS HOLDS THE FRONT BACK
CLEARING ONLY THE NORTHWEST PART OF THE CWA BY 12Z MON AND THEN
DEVELOPS A SECONDARY UPPER WAVE THAT INCREASES MOISTURE OVER MOST OF
THE CWA DURING THE DAY MONDAY. AT THIS POINT WILL MAINTAIN HIGH POPS
SUNDAY AND MONDAY AND BRING LOW OR NO POPS ON TUESDAY.
17
&&
.AVIATION...
06Z UPDATE...
VFR TO START THE PERIOD...BUT EXPECT SOME MVFR STRATUS TO MOVE IN
AROUND SUNRISE DOWN NEAR MCN. IT MAY BRIEFLY MAKE IT TO THE OTHER
TAFS SO INCLUDED THAT IN A TEMPO. OTHERWISE...VFR CIGS THROUGH THE
AFTERNOON AND EVENING WITH SE WINDS GENERALLY 5-10KT. INCREASING
MOISTURE THURSDAY MORNING SHOULD BRING MVFR TO POTENTIALLY IFR
CIGS EVERYWHERE BETWEEN 08-10Z...SO TRENDED THAT WAY IN THE ATL
TAF.
//ATL CONFIDENCE...06Z UPDATE...
LOW ON POTENTIAL FOR MVFR CIGS THIS MORNING.
MEDIUM ON TIMING OF MVFR CIGS THURSDAY MORNING.
HIGH ON ALL OTHER ELEMENTS.
TDP
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 85 64 85 66 / 5 5 5 5
ATLANTA 84 67 83 66 / 5 5 5 5
BLAIRSVILLE 81 60 81 63 / 0 5 5 5
CARTERSVILLE 85 65 84 66 / 5 5 5 5
COLUMBUS 88 69 87 69 / 5 10 10 5
GAINESVILLE 82 65 81 66 / 5 5 5 5
MACON 88 66 87 67 / 5 5 5 0
ROME 87 65 85 66 / 5 5 10 10
PEACHTREE CITY 85 65 84 66 / 5 5 5 5
VIDALIA 88 69 89 69 / 5 5 5 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...TDP
LONG TERM....17
AVIATION...TDP
AREA FORECAST DISCUSSION
NWS POCATELLO ID
835 AM MDT WED MAY 29 2013
.UPDATE...SHOWERS LINGER ALONG EASTERN HIGHLANDS THIS MORNING PER
RADAR IMAGERY AND SURFACE OBSERVATIONS. REMAINDER OF EASTERN IDAHO
DRY BUT NEXT BAND OF SHOWERS ALREADY INTO WESTERN IDAHO AHEAD OF
UPPER TROUGH MOVING THROUGH THE PACNW. HRRR REDEVELOPS SHOWERS
OVER THE NORTHEAST CORNER OF THE REGION AND ALONG THE WYOMING
BORDER THROUGH THE REMAINDER OF THE MORNING. THIS MAY BE SOMEWHAT
OVERDONE WITH EARLY CLOUD COVER AND REGION OF DRIER MID LEVELS PER
WV IMAGERY BUT OROGRAPHICS AND MOIST LOW LEVELS MAY BE ENOUGH TO
OVERCOME. BAND OF PRECIP IN WESTERN IDAHO LOOKS TO REACH WESTERN
EDGES OF THE FORECAST AREA BY 18Z...SPREADING RAPIDLY ACROSS THE
REGION THROUGH THIS AFTERNOON AND EARLY EVENING. MODELS PAINT
LEAST PRECIP OVER THE SNAKE PLAIN THUS KEPT FOCUS OVER HIGHER
ELEVATIONS. MADE A FEW ADJUSTMENTS TO POP/QPF/WX GRIDS FOR TODAY
BASED ON SAT AND RADAR TRENDS. IN ADDITION...SURFACE GRADIENT
STILL ENOUGH AND GUIDANCE STILL SUPPORTIVE OF WINDS FAVORABLE FOR
CHOP ON THE RESERVOIR SO WILL LEAVE CURRENT LAKE WIND ADVISORY IN
PLACE. DMH
&&
.PREV DISCUSSION... /ISSUED 313 AM MDT WED MAY 29 2013/
DISCUSSION...UPPER TROUGH CURRENTLY OVER THE WA/OR COAST MAKING ITS
WAY INLAND. THIS TROUGH SHOULD IMPACT SOUTHEAST IDAHO LATER TODAY.
MODELS INDICATE SOME INSTABILITY WILL BE OVER THE REGION LATER THIS
AFTERNOON WITH LI VALUES GENERALLY AROUND 0C TO -1C. STABILITY COULD
BE LOWER IF WE MANAGE TO SEE SUFFICIENT CLEARING THIS
AFTERNOON...AND THE NAM AND LOCAL WRF RUNS HINT AT THAT POSSIBILITY.
HAVE LEFT SLIGHT CHANCE TS MENTION FOR THE AFTERNOON/EVENING. BEGAN
TRIMMING POPS AFTER THE UPPER TROUGH PASSES AS UPPER RIDGING BUILDS
BACK IN TO THE WEST. ALSO TODAY...WINDS WILL BE STRONG ENOUGH TO
WARRANT A LAKE WIND ADVISORY FOR AMERICAN FALLS RESERVOIR. SHOWERS
MAY BUILD BACK INTO THE UPPER SNAKE HIGHLANDS THURSDAY WITH ENERGY
ROTATING AROUND AN WEAK UPPER LOW OVER EASTERN WY/MT. THE WEEKEND
SHOULD BE FAIRLY DRY WITH UPPER RIDGING MOVING ACROSS IDAHO...BUT
MODELS CONTINUE TO DIG AN UPPER TROUGH OVER THE PAC NORTHWEST ON
SUNDAY AND MONDAY. GFS/ECMWF KEEP MOST OF THE QPF WITH THE TROUGH
FURTHER TO THE NORTH WHERE THE SOUTHERN END OF THE TROUGH DOES NOT
HAVE VERY MUCH MOISTURE TO WORK WITH. HINSBERGER
AVIATION...LOW PRESSURE DISTURBANCE NEAR THE OREGON COAST THIS
MORNING EXPECTED TO CROSS SOUTHEAST IDAHO THIS AFTERNOON. ISOLATED
THUNDERSTORMS POSSIBLE AT TAF SITES BETWEEN 19-01Z. OUTFLOW GUSTS UP
TO 45 MPH AND SMALL HAIL POSSIBLE. NAM12 SURFACE FRONT DEPICTION
TRAILS WET-EAST ORIENTATION THROUGH ABOUT SALMON IDAHO...THEREFORE
BREEZY WSW WINDS OF 15-20 KTS EXPECTED IN THE SNAKE PLAIN INCLUDING
KBYI...KIDA...AND KPIH BUT NO SIGNIFICANT FRONTAL WIND SHIFT.
THURSDAY AFTERNOON...WEAK HIGH PRESSURE RIDGING TO THE WEST RESULTS
IN AFTERNOON CONVECTION SHIFTING FURTHER NORTH...AT LEAST FOR KBYI
AND KPIH. THERE WILL BE A SLIGHT CHANCE OF SHOWERS NEAR KSUN AND
KIDA. RS
FIRE WEATHER...A LOW PRESSURE DISTURBANCE NEAR THE OREGON COAST
THIS MORNING WILL CROSS SOUTHEAST IDAHO THIS AFTERNOON. SCATTERED
RAIN SHOWERS WITH ISOLATED THUNDERSTORMS THIS AFTERNOON EXPECTED
ACROSS THE DISTRICT BETWEEN NOON AND ABOUT 1900 HOURS. THE
ASSOCIATED FRONTAL BOUNDARY WILL BE ORIENTED WEST TO EAST THROUGH
THE SALMON AREA. OVER THE CENTRAL MOUNTAINS A SUBTLE SHIFT IN WINDS
FROM SOUTHWEST TO WEST IS EXPECTED NOON TO 1500 HOURS. IN THE SNAKE
PLAIN WEST-SOUTHWEST WINDS OF 15 TO 25 MPH WILL SHOW LITTLE OR NO
WIND SHIFT. WINDS IN THE SNAKE PLAIN WILL BE BREEZY OVERNIGHT AND
THROUGH THE DAY THURSDAY. RELATIVE HUMIDITY IN THE LOWER VALLEYS
WILL BE 30 TO 40 PERCENT TODAY AND TREND DOWNWARD TO THE LOWER 20S
BY FRIDAY AFTERNOON. RS
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM NOON TODAY TO 9 PM MDT THIS EVENING
IDZ021.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1000 PM CDT THU MAY 30 2013
.MESOSCALE DISCUSSION...
933 PM CDT
SMALL SCALE BOWING SEGMENT IS SURGING NORTHEAST INTO LIVINGSTON/FORD
COUNTIES. OBSERVATIONAL TRENDS AND DATA FROM KILX FROM ABOUT AN HOUR
AGO SUGGEST THAT THE STRONG WINDS WITH THAT SURGING BOW ECHO ARE NOT
REACHING THE SURFACE TO THE WEST OF THE ROUGHLY NORTH-SOUTH ORIENTED
OUTFLOW BOUNDARY CURRENTLY EXTENDING FROM EVANSTON TO
MCLEAN/FORD/LIVINGSTON CO BORDER. FAIRLY STRONG MESOVORTEX WAS
EVIDENT ON RADAR IMAGERY AT THE INTERSECTION OF THAT BOW WITH THE
N/S ORIENTED OUFLOW WHICH IS WHAT PROMTED THE LAST SVR WARNING.
SUSPECT THAT THE PRIMARY SEVERE THREAT WILL EXIST EAST OF THE
INITIAL OUTFLOW...HOWEVER DUE TO THE SLIGHT UPTICK IN LIGHTNING AND
COOLING CLOUD TOPS ON IR WITH THE BOW TO THE WEST OF THE N-S OUTFLOW
HAVE DECIDED TO HANG ONTO THE SVR TSTM WATCH 255 FOR REMAINING
COUNTIES EVEN WEST OF THE OUTFLOW OUT OF AN ABUNDANCE OF CAUTION.
IZZI
&&
.DISCUSSION...
504 PM CDT
HAVE DECIDED TO EXPAND THE CURRENT FLASH FLOOD WATCH...TO INCLUDE
THE ENTIRE CWA.
WAS ON THE FENCE EARLIER WITH REGARDS TO EXPANDING THE CURRENT
FLASH FLOOD WATCH FOR THE REMAINDER OF THE CWA...BUT WITH LATEST
TRENDS THIS PAST AFTERNOON...HAVE DECIDED TO INCLUDE THE ENTIRE
CWA. THE THUNDERSTORMS THIS PAST AFTERNOON HAVE BEEN VERY GOOD
RAIN PRODUCERS...WHICH WILL LIKELY CONTINUE OVER THE NEXT COUPLE
OF HOURS AS PWATS REMAIN RATHER HIGH. ALSO...MONITORING THE
CONVECTIVE LINE TO THE WEST AND ITS MOVEMENT EAST INTO THE CWA.
LATEST TRENDS AND SHORT TERM GUIDANCE ARE HINTING AT THE
POSSIBILITY OF MORE TRAINING ACROSS THE CWA...WITH CURRENT FLOW IN
PLACE...DEFINITELY SEEMS REASONABLE.
RODRIGUEZ
//PREV DISCUSSION...
400 PM CDT
MAIN FORECAST CONCERNS REMAIN TIED TO THE ACTIVE WEATHER PATTERN
EXPECTED THROUGH THE START OF THE WEEKEND...WITH ROUNDS OF HEAVY
RAINFALL LIKELY AS WELL AS CONTINUED CHANCES FOR SEVERE WEATHER.
HAVE NOT EXPANDED THE FFA WATCH AT THIS TIME WITH MORE WIDESPREAD
HEAVY RAINFALL AND FLOODING NOT APPEARING LIKELY UNTIL LATER
FRIDAY AFTERNOON INTO FRIDAY NIGHT. THIS IS NOT TO SAY THAT
LOCALIZED FLOODING COULD NOT OCCUR WITH ANY POSSIBLE STRONG
THUNDERSTORMS TONIGHT. A MORE LIKELY SCENARIO AT THIS TIME IS WITH
THE CURRENT SCATTERED DEVELOPMENT TO BE REPLACED WITH A MORE
PROGRESSIVE AREA OF THUNDERSTORMS.
CURRENT ISOLATED TO SCATTERED ACTIVITY ACROSS THE CWA WILL
CONTINUE TO INCREASE IN COVERAGE THIS EVENING...AS LARGE SCALE
FORCING INCREASES WITH THE APPROACH A FAIRLY STOUT MID LEVEL WAVE
PROPAGATING NORTH THROUGH CENTRAL ILLINOIS. AREAS WHICH CONTINUE
TO BE FAVORED ARE LOCATIONS ALONG AND WEST OF A LINE FROM CRYSTAL
LAKE SOUTH TO GIBSON CITY IN ILLINOIS. LATEST RAP ANALYSIS SHOWS
MODERATE INSTABILITY IN PLACE WITH MLCAPE AROUND 2000 J/KG...AND
WITH MID/LOW LEVEL LAPSE RATES EXPECTED TO ONLY INCREASE OVER THE
NEXT COUPLE OF HOURS. THIS INCREASING FORCING AND INSTABILITY WILL
AID FURTHER DEVELOPMENT/EXPANSION OF CURRENT ACTIVITY ONGOING
ACROSS THE WESTERN HALF OF THE CWA. DEEP LAYER SHEAR REMAINS
MEAGER AT 25-30KT PRIMARILY OVER THE WESTERN CWA WHILE 0-1KM SHEAR
ALSO REMAINS HIGHEST ALONG OR JUST WEST OF THE CWA...ESPECIALLY
GOING INTO WESTERN ILLINOIS AND EASTERN IOWA.
HOWEVER...SHORT TERM GUIDANCE CONTINUES TO SHOW AN INCREASE IN
BOTH DEEP LAYER SHEAR AND LOW LEVEL SHEAR ACROSS THE CURRENT WATCH
AREA THROUGH THE REMAINDER OF THE AFTERNOON. THIS WILL HELP FOR
MORE ORGANIZED AND LONGER LIVED DEVELOPMENT ACROSS THE WESTERN
CWA...LEAVING THE THREAT OF HAIL/DAMAGING WINDS AS WELL AS
POSSIBLE TORNADOES. ALTHOUGH MORE ORGANIZED DEVELOPMENT IS MORE
LIKELY FOR THE WESTERN HALF OF THE CWA...SHORT TERM GUIDANCE IS
HINTING AT A SLIGHT INCREASE IN DEEP LAYER SHEAR MORE TOWARDS FAR
NORTHEAST ILLINOIS. THIS SLIGHT INCREASE COINCIDING WITH THE
CURRENT CAPE IN PLACE...COULD FAVOR SOME ISOLATED STRONGER
DEVELOPMENT IN THAT LOCATION IN THE NEXT COUPLE OF HOURS. WILL
NEED CONTINUE TO MONITOR DEVELOPMENT IN THAT LOCATION...WHICH
WOULD INCLUDE THE CITY OF CHICAGO/METRO AREA LATE THIS AFTERNOON
INTO THE EARLY EVENING...AS I COULD EASILY FORESEE AN UPSCALE IN
GROWTH IN BOTH INTENSITY AND COVERAGE.
EVEN IF THAT DOES NOT MATERIALIZE THROUGH LATE THIS
AFTERNOON...CONTINUE TO MONITOR A LARGER LINE OF THUNDERSTORMS
SITUATED FROM SOUTHERN IOWA SOUTH INTO MISSOURI. THIS LINE IS TIED
MORE CLOSELY TO FAIRLY STRONG MID LEVEL WAVE LIFTING NORTHEAST OUT
KANSAS AND ATTENDANT SURFACE TROUGH/BOUNDARY FROM IOWA INTO
MISSOURI. ALL GUIDANCE IS SHOWING THIS LINE OF THUNDERSTORMS
WILL INCREASE IN INTENSITY OVER THE NEXT COUPLE OF HOURS...WHICH
WOULD MAKE SENSE AS THIS LINE OF THUNDERSTORMS MOVES FURTHER
EAST/NORTHEAST INTO A MORE UNSTABLE ENVIRONMENT. STRONG FORCING
OWING TO LARGE SCALE SUPPORT AND LOW/MID LEVEL CONVERGENCE SHOULD
AID IN THIS LINE OF THUNDERSTORMS FURTHER BLOSSOMING AS IT MOVES
TOWARDS THE WESTERN ILLINOIS...ESPECIALLY AS DEEP LAYER SHEAR IS
ALSO INCREASING.
THERE IS STILL SOME UNCERTAINTY AS TO THE WHOLE EVOLUTION OF THIS
LINE OF THUNDERSTORMS AS IT WORKS ITS WAY TOWARDS NORTHERN
ILLINOIS THIS EVENING...MAINLY IN THE STRENGTH OF THIS COMPLEX AND
POTENTIAL SEVERE THREAT. ALTHOUGH THERE WILL BE SOME SLIGHT
DIMINISHING TREND WITH THE CURRENT INSTABILITY IN PLACE...FEEL
THAT IT WILL MORE THAN SUFFICE TO HELP KEEP THIS LINE SHIFTING
EAST. ALSO...SHORT TERM GUIDANCE IS INDICATING THAT 0-3KM BULK
SHEAR WILL INCREASE TOWARDS THE 00Z TIME FRAME THIS
EVENING...WHICH WOULD ACT TO HELP FOR ORGANIZATION AND INCREASE IN
THREAT FOR LINEAR STRUCTURES/STRONG DAMAGING WINDS. SO HAVE
TRENDED MORE PESSIMISTIC...WITH THINKING THAT THIS LINE AND STRONG
DAMAGING WINDS COULD MOVE ACROSS NORTHERN ILLINOIS THIS EVENING.
HAVE ALSO TRENDED MORE TOWARDS THE HRRR...WITH SYSTEM TIMING
THINKING THAT IT SHOULD BE KNOCKING ON THE WESTERN CWA DOORSTEPS
BY 00-01Z AND THEN CONTINUE EAST TOWARDS NORTHEAST ILLINOIS
THROUGH THE SEVERAL HOURS THERE AFTER. BEYOND THAT TIME
FRAME...CONFIDENCE LOWERS WITH REGARDS TO THE STRENGTH OF THIS
SYSTEM. NONETHELESS...HEAVY RAINFALL AND FLASH FLOODING COULD
BECOME ISSUES OVERNIGHT TONIGHT ESPECIALLY AS PWATS ARE AT OR JUST
ABOVE 1.7 INCHES AND 850MB DEW POINTS REMAIN RATHER HIGH.
THUNDERSTORM COMPLEX IS THEN EXPECTED TO SHIFT EAST OF THE CWA BY
EARLY FRIDAY MORNING...WITH A DRYING TREND EXPECTED DURING THAT
TIME FRAME. THIS SHOULD NOT LAST TOO LONG WITH DRY CONDITIONS ONLY
EXPECTED THROUGH MID DAY AS ATTENTION QUICKLY SHIFTS BACK WEST
WITH THE APPROACH OF ANOTHER STRONG MID LEVEL WAVE EJECTING OUT OF
THE CENTRAL PLAINS. YET AGAIN...A SEVERE THREAT WILL BE IN PLACE
ON FRIDAY WITH GROWING CONCERNS OF MORE POTENTIAL FLOODING FROM
THIS POINT ON...INTO FRIDAY NIGHT AND SATURDAY. THE SEVERE THREAT
WILL LIKELY AFFECT THE ENTIRE CWA ON FRIDAY AND WITH CLEARING
ANTICIPATED FRIDAY MORNING...INSTABILITY IS EXPECTED TO RAPIDLY
INCREASE BY LATE MORNING WITH MODERATE TO STRONG INSTABILITY
LIKELY IN PLACE ACROSS THE CWA. STRONG DEEP LAYER SHEAR IN UPWARDS
OF 50-60KT WILL EASILY SUPPORT WIDESPREAD ORGANIZED DEVELOPMENT AS
SOON AS EARLY AFTERNOON ON FRIDAY. STRONG DAMAGING WINDS AND HAIL
ARE THE MAIN THREAT...BUT WITH SREF GUIDANCE INDICATING ELEMENTS
CORRESPONDING TO SUPERCELLULAR STRUCTURES OR ROTATING
THUNDERSTORMS COULD COME TOGETHER ACROSS THE CWA. WILL NEED TO
CONTINUE TO MONITOR THIS TIME FRAME AS WELL...AS WIDESPREAD SEVERE
IS APPEARING LIKELY ONCE AGAIN. GOING INTO FRIDAY NIGHT...HEAVY
RAINFALL APPEARS LIKELY WITH SEVERAL STRONG WAVES PROPAGATING
NORTHEAST ACROSS THE CWA PROVIDING CONTINUED DEVELOPMENT AS WELL
AS A STRONG LLJ ORIENTED TOWARDS NORTHEAST ILLINOIS...PUMPING HIGH
THETAE AIR INTO THE REGION.
RODRIGUEZ
EXTENDED PERIOD...SUNDAY THROUGH THURSDAY...
BY DAYBREAK SUNDAY THE UPPER RIDGE IS TO HAVE PROGRESSED EASTWARD
TO OVER THE UPPER MIDWEST AND MID MS VALLEY WITH A SURFACE
TROUGH/SECONDARY COLD FRONT JUST TO THE NORTHWEST AND NORTH OF THE
LOCAL FORECAST AREA. THIS TROUGH/FRONT IS PROGGED TO MOVE ACROSS ALL
OF THE FA DURING THE SUNDAY MORNING AS THE UPPER TROUGH CONTINUES ON
TO OVER THE UPPER GREAT LAKES AND LOWER OH VALLEY BY EVENING. UNTIL
THE TROUGH AXIS MOVES A BIT FURTHER EAST OF THE IMMEDIATE AREA THERE
WILL BE A LINGERING CHANCE OF SHOWERS DURING SUNDAY MORNING.
THE SECONDARY COLD FRONT WILL REINFORCE THE COLD AIR ADVECTION THAT
WILL HAVE STARTED TO OCCUR LATE SATURDAY AND SATURDAY NIGHT WITH THE
INITIAL COLD FRONT. BETWEEN THE PAIR OF FRONT 850HPA TEMPERATURES
ARE PROGGED TO FALL AROUND 10 DEGREES C FROM 18Z SATURDAY TO 00Z
MONDAY......DOWN TO AROUND +4 OR +5C. WITH COOL HIGH PRESSURE
BUILDING OVER THE AREA TEMPERATURES WILL BE COOL SUNDAY AND MONDAY
WITH HIGHS ONLY IN THE 60S...WITH LAKESIDE MAX TEMPERATURES LIKELY
TO ONLY BE IN THE 55-60F RANGE AS A LONG FETCH DOWN LAKE MICHIGAN
BRINGS AIR ADDITIONALLY COOLED BY THE STILL CHILLY LAKE ASHORE
SUNDAY. WHILE THE SURFACE RIDGE AXIS WILL BE MOVING OVER WI AND
WESTERN IL DURING MONDAY ALLOWING WINDS TO SLACKEN...A WEAK NE
SYNOPTIC FLOW WILL STILL BE IN PLACE AIDED BY A LAKE BREEZE.
THE FURTHER EASTWARD PROGRESS OF THE UPPER TROUGH IS TO BE SLOW AS A
CLOSED LOW TO FORM OVER SOUTHERN HUDSON BAY/NORTHERN ONTARIO IS
PROGGED TO BE DROP SOUTH...THEN SOUTHEAST AND EAST OVER ONTARIO
SATURDAY NIGHT THROUGH MONDAY NIGHT. AS THE UPPER TROUGH/LOW MOVES
FURTHER EAST A WEAK UPPER RIDGE WILL MOVE OVER THE REGION TUESDAY AS
ANOTHER UPPER LOW MOVES EAST OVER THE FAR SOUTHERN CANADIAN
PRAIRIE/FAR NORTHERN PLAINS. THIS WILL ALLOW A BIT OF MODERATION IN
TEMPERATURES TUESDAY AND WEDNESDAY AS EAST-SOUTHEAST WINDS BECOMES
SOUTHEASTERLY AND INCREASING THOUGH THIS LOW LEVEL FLOW WILL KEEP
THE IL SHORE...ESPECIALLY THE FAR NORTHERN PART....STILL CHILLY.
INLAND AREAS SHOULD PEAK IN THE UPPER 60S AND LOWER 70S TUESDAY...
AND A COUPLE DEGREES WARMER WEDNESDAY. WITH CONTINUED WARM AIR
ADVECTION AHEAD OF THE APPROACHING UPPER LOW/TROUGH THE WARMING
TREND WILL CONTINUE THURSDAY WITH MOST LOCATIONS REACHING THE MID
AND UPPER 70S THOUGH THERE WILL STILL BE AN EASTERLY COMPONENT TO
THE LOW LEVEL FLOW TO KEEP THE IL SHORELINE IN THE 60S.
TRS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* LINE OF THUNDERSTORMS LIFTING NORTHEAST INTO CHICAGO METRO 03Z-04Z.
* GUST FRONT AND ABRUPT WIND SHIFT TO WEST WINDS AHEAD OF
DECAYING LINE OF STORMS SLOWING AS IT MOVES INTO LAKE MICHIGAN
AND APPROACHES INDIANA STATE LINE.
* STABLE OUTFLOW UNDERCUTTING APPROACHING THUNDERSTORMS FROM THE
SOUTHWEST EXPECTED TO PREVENT THESE STORMS FROM INTENSIFYING AS
THEY APPROACH ORD/MDW.
* SURFACE WINDS TO GRADUALLY BACK TO SOUTHERLY (190) AS SHOWERS/ THUNDERSTORMS
CONTINUE TO MOVE THROUGH.
ED F
//DISCUSSION...UPDATED 00Z...
ACTIVE WEATHER PERIOD TO CONTINUE TONIGHT... FRIDAY... AND INTO
SATURDAY WITH SEVERAL PERIODS OF SHOWERS AND THUNDERSTORMS. THE
NEXT WILL COME IN THE FORM OF A LINE OF STORMS IN THE SHAPE OF A
LARGE BOW ECHO ON WEATHER RADAR. THIS BOW...ALBEIT SOMEWHAT RAGGED
IN APPEARANCE ON RADAR... WILL CONTINUE TO MARCH ACROSS THE AREA
THIS EVENING. SURFACE REPORTS SHOWING GUST FRONT WINDS AHEAD OF
THE LINE GENERALLY AROUND 40 KTS... WITH ISOLATED DAMAGING WIND
GUSTS TO 60 KTS ASSOCIATED WITH THE MOST INTENSE CELLS WITHIN THE
LINE.
EXTRAPOLATION OF LINE TIMES GUST FRONT/LEADING EDGE OF
THUNDERSTORMS TO RFD AROUND 0015Z... ORD 0130Z... AND MDW AROUND
0145Z. BRIEF (AROUND 20 MINUTE) PERIOD OF TORRENTIAL RAIN AND IFR
VISIBILITY POSSIBLE WITH ONSET OF STORMS... TO BE FOLLOWED BY A
LONGER PERIOD (1-2 HOURS) OF MORE MODERATE RAIN SHOWERS WITH
EMBEDDED THUNDER.
EXPECT BRAKE IN THE PRECIPITATION LATER INTO THE OVERNIGHT
EXTENDING INTO THE DAYTIME FRIDAY. NEXT APPROACHING UPPER LEVEL
DISTURBANCE WILL HELP TO ORGANIZE ANOTHER ROUND OF THUNDERSTORMS
FRIDAY AFTERNOON.
ED F
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* MEDIUM CONFIDENCE IN SHOWER AND THUNDERSTORM TRENDS NEXT FEW HOURS.
* MEDIUM CONFIDENCE IN ADDITIONAL TSTMS FRIDAY...LOW CONFIDENCE
IN TIMING.
* MEDIUM TO HIGH CONFIDENCE IN WIND TRENDS.
ED F
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
* FRIDAY THROUGH SATURDAY...PERIODS OF TSRA/SHRA.
POSSIBLE WITH MVFR CIGS/VIS.
* SUNDAY...CHANCE OF SHRA EARLY...OTRW...VFR.
* MONDAY THROUGH EARLY TUESDAY...VFR. WX NIL.
* LATE TUESDAY THROUGH WEDNESDAY...CHANCE TSRA/SHRA.
KREIN
&&
.MARINE...
1259 PM CDT
THE SHORT TERM OF THE MARINE FORECAST HAS A SMALL CRAFT ADVISORY FOR
STRONG WINDS ACROSS THE ILLINOIS AND NORTHWEST INDIANA NEARSHORE
WATERS.
ACROSS THE OPEN WATERS OF THE LAKE...MAINLY THE NORTHERN THIRD OF
THE LAKE...AREAS OF DENSE FOG CONTINUE.
VERY WARM/MOIST AIR CONTINUES TO SLIDE NORTH ACROSS THE LAKE...AND
WITH THE MUCH COOLER LAKE SURFACE WATER...HAS RESULTED IN AREAS OF
DENSE FOG PERSISTING. IT DOES APPEAR BASED ON LATEST VISIBLE IMAGERY
THAT THE FOG HAS REMAINED FOCUSED ACROSS THE NORTHERN THIRD OF THE
LAKE. OBS HAVE CONTINUED TO SHOW INCREASING GUSTS...WITH SPEEDS
GENERALLY AROUND 20-25KT ACROSS THE SOUTHERN HALF OF THE LAKE.
FURTHER NORTH IT APPEARS THE WINDS ARE SLIGHTLY LESS...WITH SPEEDS
GENERALLY IN THE 15-25KT.
THE TROUGH OF LOW PRESSURE REMAINS CENTERED ACROSS THE CENTRAL
PLAINS...WITH A WEAK LOW PRESSURE LIFTING NORTH INTO THE NORTHERN
PLAINS. AN ASSOCIATED WARM FRONT EXTENDS EAST THROUGH THE UPPER
GREAT LAKES REGION. WITH THE POSITION OF THE LOW PRESSURE AND THE
PERSISTING RIDGE OF HIGH PRESSURE ACROSS THE SOUTHEASTERN UNITED
STATES...THE WIND FLOW WILL REMAIN SOUTHERLY ACROSS THE LAKE. AT
TIMES THROUGH EARLY THIS EVENING GUSTS MAY APPROACH 30 KT...MAINLY
FOR THE SOUTHERN PORTIONS OF THE LAKE INCLUDING THE NEARSHORE
WATERS. AS A RESULT WILL MAINTAIN THE CURRENT SMALL CRAFT ADVISORY
THAT IS IN EFFECT.
THE TROUGH OF LOW PRESSURE POSITIONED OVER THE CENTRAL PLAINS WILL
SLOWLY PUSH EAST...WITH A LOW PRESSURE APPROACHING THE WESTERN GREAT
LAKES SAT MIDDAY. THE RECENT FORECAST TRENDS HAVE BEEN TO SLOW THE
ARRIVAL OF THIS SYSTEM...THUS IT IS POSSIBLE THAT THE MAIN LOW
PRESSURE MAY NOT ARRIVE UNTIL CLOSER TO SAT NIGHT. THEN AN
ASSOCIATED COLD FRONT WILL WILL PUSH EAST ACROSS THE LAKE OVERNIGHT
SAT INTO SUN. WINDS AT THAT POINT WILL TURN WESTERLY THEN NORTHERLY
WITH MUCH COOLER AIR FLOWING OVER THE LAKE.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 7 PM SATURDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 7
PM SATURDAY.
LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565
UNTIL 7 AM FRIDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
933 PM CDT THU MAY 30 2013
.MESOSCALE DISCUSSION...
933 PM CDT
SMALL SCALE BOWING SEGMENT IS SURGING NORTHEAST INTO LIVINGSTON/FORD
COUNTIES. OBSERVATIONAL TRENDS AND DATA FROM KILX FROM ABOUT AN HOUR
AGO SUGGEST THAT THE STRONG WINDS WITH THAT SURGING BOW ECHO ARE NOT
REACHING THE SURFACE TO THE WEST OF THE ROUGHLY NORTH-SOUTH ORIENTED
OUTFLOW BOUNDARY CURRENTLY EXTENDING FROM EVANSTON TO
MCLEAN/FORD/LIVINGSTON CO BORDER. FAIRLY STRONG MESOVORTEX WAS
EVIDENT ON RADAR IMAGERY AT THE INTERSECTION OF THAT BOW WITH THE
N/S ORIENTED OUFLOW WHICH IS WHAT PROMTED THE LAST SVR WARNING.
SUSPECT THAT THE PRIMARY SEVERE THREAT WILL EXIST EAST OF THE
INITIAL OUTFLOW...HOWEVER DUE TO THE SLIGHT UPTICK IN LIGHTNING AND
COOLING CLOUD TOPS ON IR WITH THE BOW TO THE WEST OF THE N-S OUTFLOW
HAVE DECIDED TO HANG ONTO THE SVR TSTM WATCH 255 FOR REMAINING
COUNTIES EVEN WEST OF THE OUTFLOW OUT OF AN ABUNDANCE OF CAUTION.
IZZI
&&
.DISCUSSION...
504 PM CDT
HAVE DECIDED TO EXPAND THE CURRENT FLASH FLOOD WATCH...TO INCLUDE
THE ENTIRE CWA.
WAS ON THE FENCE EARLIER WITH REGARDS TO EXPANDING THE CURRENT
FLASH FLOOD WATCH FOR THE REMAINDER OF THE CWA...BUT WITH LATEST
TRENDS THIS PAST AFTERNOON...HAVE DECIDED TO INCLUDE THE ENTIRE
CWA. THE THUNDERSTORMS THIS PAST AFTERNOON HAVE BEEN VERY GOOD
RAIN PRODUCERS...WHICH WILL LIKELY CONTINUE OVER THE NEXT COUPLE
OF HOURS AS PWATS REMAIN RATHER HIGH. ALSO...MONITORING THE
CONVECTIVE LINE TO THE WEST AND ITS MOVEMENT EAST INTO THE CWA.
LATEST TRENDS AND SHORT TERM GUIDANCE ARE HINTING AT THE
POSSIBILITY OF MORE TRAINING ACROSS THE CWA...WITH CURRENT FLOW IN
PLACE...DEFINITELY SEEMS REASONABLE.
RODRIGUEZ
//PREV DISCUSSION...
400 PM CDT
MAIN FORECAST CONCERNS REMAIN TIED TO THE ACTIVE WEATHER PATTERN
EXPECTED THROUGH THE START OF THE WEEKEND...WITH ROUNDS OF HEAVY
RAINFALL LIKELY AS WELL AS CONTINUED CHANCES FOR SEVERE WEATHER.
HAVE NOT EXPANDED THE FFA WATCH AT THIS TIME WITH MORE WIDESPREAD
HEAVY RAINFALL AND FLOODING NOT APPEARING LIKELY UNTIL LATER
FRIDAY AFTERNOON INTO FRIDAY NIGHT. THIS IS NOT TO SAY THAT
LOCALIZED FLOODING COULD NOT OCCUR WITH ANY POSSIBLE STRONG
THUNDERSTORMS TONIGHT. A MORE LIKELY SCENARIO AT THIS TIME IS WITH
THE CURRENT SCATTERED DEVELOPMENT TO BE REPLACED WITH A MORE
PROGRESSIVE AREA OF THUNDERSTORMS.
CURRENT ISOLATED TO SCATTERED ACTIVITY ACROSS THE CWA WILL
CONTINUE TO INCREASE IN COVERAGE THIS EVENING...AS LARGE SCALE
FORCING INCREASES WITH THE APPROACH A FAIRLY STOUT MID LEVEL WAVE
PROPAGATING NORTH THROUGH CENTRAL ILLINOIS. AREAS WHICH CONTINUE
TO BE FAVORED ARE LOCATIONS ALONG AND WEST OF A LINE FROM CRYSTAL
LAKE SOUTH TO GIBSON CITY IN ILLINOIS. LATEST RAP ANALYSIS SHOWS
MODERATE INSTABILITY IN PLACE WITH MLCAPE AROUND 2000 J/KG...AND
WITH MID/LOW LEVEL LAPSE RATES EXPECTED TO ONLY INCREASE OVER THE
NEXT COUPLE OF HOURS. THIS INCREASING FORCING AND INSTABILITY WILL
AID FURTHER DEVELOPMENT/EXPANSION OF CURRENT ACTIVITY ONGOING
ACROSS THE WESTERN HALF OF THE CWA. DEEP LAYER SHEAR REMAINS
MEAGER AT 25-30KT PRIMARILY OVER THE WESTERN CWA WHILE 0-1KM SHEAR
ALSO REMAINS HIGHEST ALONG OR JUST WEST OF THE CWA...ESPECIALLY
GOING INTO WESTERN ILLINOIS AND EASTERN IOWA.
HOWEVER...SHORT TERM GUIDANCE CONTINUES TO SHOW AN INCREASE IN
BOTH DEEP LAYER SHEAR AND LOW LEVEL SHEAR ACROSS THE CURRENT WATCH
AREA THROUGH THE REMAINDER OF THE AFTERNOON. THIS WILL HELP FOR
MORE ORGANIZED AND LONGER LIVED DEVELOPMENT ACROSS THE WESTERN
CWA...LEAVING THE THREAT OF HAIL/DAMAGING WINDS AS WELL AS
POSSIBLE TORNADOES. ALTHOUGH MORE ORGANIZED DEVELOPMENT IS MORE
LIKELY FOR THE WESTERN HALF OF THE CWA...SHORT TERM GUIDANCE IS
HINTING AT A SLIGHT INCREASE IN DEEP LAYER SHEAR MORE TOWARDS FAR
NORTHEAST ILLINOIS. THIS SLIGHT INCREASE COINCIDING WITH THE
CURRENT CAPE IN PLACE...COULD FAVOR SOME ISOLATED STRONGER
DEVELOPMENT IN THAT LOCATION IN THE NEXT COUPLE OF HOURS. WILL
NEED CONTINUE TO MONITOR DEVELOPMENT IN THAT LOCATION...WHICH
WOULD INCLUDE THE CITY OF CHICAGO/METRO AREA LATE THIS AFTERNOON
INTO THE EARLY EVENING...AS I COULD EASILY FORESEE AN UPSCALE IN
GROWTH IN BOTH INTENSITY AND COVERAGE.
EVEN IF THAT DOES NOT MATERIALIZE THROUGH LATE THIS
AFTERNOON...CONTINUE TO MONITOR A LARGER LINE OF THUNDERSTORMS
SITUATED FROM SOUTHERN IOWA SOUTH INTO MISSOURI. THIS LINE IS TIED
MORE CLOSELY TO FAIRLY STRONG MID LEVEL WAVE LIFTING NORTHEAST OUT
KANSAS AND ATTENDANT SURFACE TROUGH/BOUNDARY FROM IOWA INTO
MISSOURI. ALL GUIDANCE IS SHOWING THIS LINE OF THUNDERSTORMS
WILL INCREASE IN INTENSITY OVER THE NEXT COUPLE OF HOURS...WHICH
WOULD MAKE SENSE AS THIS LINE OF THUNDERSTORMS MOVES FURTHER
EAST/NORTHEAST INTO A MORE UNSTABLE ENVIRONMENT. STRONG FORCING
OWING TO LARGE SCALE SUPPORT AND LOW/MID LEVEL CONVERGENCE SHOULD
AID IN THIS LINE OF THUNDERSTORMS FURTHER BLOSSOMING AS IT MOVES
TOWARDS THE WESTERN ILLINOIS...ESPECIALLY AS DEEP LAYER SHEAR IS
ALSO INCREASING.
THERE IS STILL SOME UNCERTAINTY AS TO THE WHOLE EVOLUTION OF THIS
LINE OF THUNDERSTORMS AS IT WORKS ITS WAY TOWARDS NORTHERN
ILLINOIS THIS EVENING...MAINLY IN THE STRENGTH OF THIS COMPLEX AND
POTENTIAL SEVERE THREAT. ALTHOUGH THERE WILL BE SOME SLIGHT
DIMINISHING TREND WITH THE CURRENT INSTABILITY IN PLACE...FEEL
THAT IT WILL MORE THAN SUFFICE TO HELP KEEP THIS LINE SHIFTING
EAST. ALSO...SHORT TERM GUIDANCE IS INDICATING THAT 0-3KM BULK
SHEAR WILL INCREASE TOWARDS THE 00Z TIME FRAME THIS
EVENING...WHICH WOULD ACT TO HELP FOR ORGANIZATION AND INCREASE IN
THREAT FOR LINEAR STRUCTURES/STRONG DAMAGING WINDS. SO HAVE
TRENDED MORE PESSIMISTIC...WITH THINKING THAT THIS LINE AND STRONG
DAMAGING WINDS COULD MOVE ACROSS NORTHERN ILLINOIS THIS EVENING.
HAVE ALSO TRENDED MORE TOWARDS THE HRRR...WITH SYSTEM TIMING
THINKING THAT IT SHOULD BE KNOCKING ON THE WESTERN CWA DOORSTEPS
BY 00-01Z AND THEN CONTINUE EAST TOWARDS NORTHEAST ILLINOIS
THROUGH THE SEVERAL HOURS THERE AFTER. BEYOND THAT TIME
FRAME...CONFIDENCE LOWERS WITH REGARDS TO THE STRENGTH OF THIS
SYSTEM. NONETHELESS...HEAVY RAINFALL AND FLASH FLOODING COULD
BECOME ISSUES OVERNIGHT TONIGHT ESPECIALLY AS PWATS ARE AT OR JUST
ABOVE 1.7 INCHES AND 850MB DEW POINTS REMAIN RATHER HIGH.
THUNDERSTORM COMPLEX IS THEN EXPECTED TO SHIFT EAST OF THE CWA BY
EARLY FRIDAY MORNING...WITH A DRYING TREND EXPECTED DURING THAT
TIME FRAME. THIS SHOULD NOT LAST TOO LONG WITH DRY CONDITIONS ONLY
EXPECTED THROUGH MID DAY AS ATTENTION QUICKLY SHIFTS BACK WEST
WITH THE APPROACH OF ANOTHER STRONG MID LEVEL WAVE EJECTING OUT OF
THE CENTRAL PLAINS. YET AGAIN...A SEVERE THREAT WILL BE IN PLACE
ON FRIDAY WITH GROWING CONCERNS OF MORE POTENTIAL FLOODING FROM
THIS POINT ON...INTO FRIDAY NIGHT AND SATURDAY. THE SEVERE THREAT
WILL LIKELY AFFECT THE ENTIRE CWA ON FRIDAY AND WITH CLEARING
ANTICIPATED FRIDAY MORNING...INSTABILITY IS EXPECTED TO RAPIDLY
INCREASE BY LATE MORNING WITH MODERATE TO STRONG INSTABILITY
LIKELY IN PLACE ACROSS THE CWA. STRONG DEEP LAYER SHEAR IN UPWARDS
OF 50-60KT WILL EASILY SUPPORT WIDESPREAD ORGANIZED DEVELOPMENT AS
SOON AS EARLY AFTERNOON ON FRIDAY. STRONG DAMAGING WINDS AND HAIL
ARE THE MAIN THREAT...BUT WITH SREF GUIDANCE INDICATING ELEMENTS
CORRESPONDING TO SUPERCELLULAR STRUCTURES OR ROTATING
THUNDERSTORMS COULD COME TOGETHER ACROSS THE CWA. WILL NEED TO
CONTINUE TO MONITOR THIS TIME FRAME AS WELL...AS WIDESPREAD SEVERE
IS APPEARING LIKELY ONCE AGAIN. GOING INTO FRIDAY NIGHT...HEAVY
RAINFALL APPEARS LIKELY WITH SEVERAL STRONG WAVES PROPAGATING
NORTHEAST ACROSS THE CWA PROVIDING CONTINUED DEVELOPMENT AS WELL
AS A STRONG LLJ ORIENTED TOWARDS NORTHEAST ILLINOIS...PUMPING HIGH
THETAE AIR INTO THE REGION.
RODRIGUEZ
EXTENDED PERIOD...SUNDAY THROUGH THURSDAY...
BY DAYBREAK SUNDAY THE UPPER RIDGE IS TO HAVE PROGRESSED EASTWARD
TO OVER THE UPPER MIDWEST AND MID MS VALLEY WITH A SURFACE
TROUGH/SECONDARY COLD FRONT JUST TO THE NORTHWEST AND NORTH OF THE
LOCAL FORECAST AREA. THIS TROUGH/FRONT IS PROGGED TO MOVE ACROSS ALL
OF THE FA DURING THE SUNDAY MORNING AS THE UPPER TROUGH CONTINUES ON
TO OVER THE UPPER GREAT LAKES AND LOWER OH VALLEY BY EVENING. UNTIL
THE TROUGH AXIS MOVES A BIT FURTHER EAST OF THE IMMEDIATE AREA THERE
WILL BE A LINGERING CHANCE OF SHOWERS DURING SUNDAY MORNING.
THE SECONDARY COLD FRONT WILL REINFORCE THE COLD AIR ADVECTION THAT
WILL HAVE STARTED TO OCCUR LATE SATURDAY AND SATURDAY NIGHT WITH THE
INITIAL COLD FRONT. BETWEEN THE PAIR OF FRONT 850HPA TEMPERATURES
ARE PROGGED TO FALL AROUND 10 DEGREES C FROM 18Z SATURDAY TO 00Z
MONDAY......DOWN TO AROUND +4 OR +5C. WITH COOL HIGH PRESSURE
BUILDING OVER THE AREA TEMPERATURES WILL BE COOL SUNDAY AND MONDAY
WITH HIGHS ONLY IN THE 60S...WITH LAKESIDE MAX TEMPERATURES LIKELY
TO ONLY BE IN THE 55-60F RANGE AS A LONG FETCH DOWN LAKE MICHIGAN
BRINGS AIR ADDITIONALLY COOLED BY THE STILL CHILLY LAKE ASHORE
SUNDAY. WHILE THE SURFACE RIDGE AXIS WILL BE MOVING OVER WI AND
WESTERN IL DURING MONDAY ALLOWING WINDS TO SLACKEN...A WEAK NE
SYNOPTIC FLOW WILL STILL BE IN PLACE AIDED BY A LAKE BREEZE.
THE FURTHER EASTWARD PROGRESS OF THE UPPER TROUGH IS TO BE SLOW AS A
CLOSED LOW TO FORM OVER SOUTHERN HUDSON BAY/NORTHERN ONTARIO IS
PROGGED TO BE DROP SOUTH...THEN SOUTHEAST AND EAST OVER ONTARIO
SATURDAY NIGHT THROUGH MONDAY NIGHT. AS THE UPPER TROUGH/LOW MOVES
FURTHER EAST A WEAK UPPER RIDGE WILL MOVE OVER THE REGION TUESDAY AS
ANOTHER UPPER LOW MOVES EAST OVER THE FAR SOUTHERN CANADIAN
PRAIRIE/FAR NORTHERN PLAINS. THIS WILL ALLOW A BIT OF MODERATION IN
TEMPERATURES TUESDAY AND WEDNESDAY AS EAST-SOUTHEAST WINDS BECOMES
SOUTHEASTERLY AND INCREASING THOUGH THIS LOW LEVEL FLOW WILL KEEP
THE IL SHORE...ESPECIALLY THE FAR NORTHERN PART....STILL CHILLY.
INLAND AREAS SHOULD PEAK IN THE UPPER 60S AND LOWER 70S TUESDAY...
AND A COUPLE DEGREES WARMER WEDNESDAY. WITH CONTINUED WARM AIR
ADVECTION AHEAD OF THE APPROACHING UPPER LOW/TROUGH THE WARMING
TREND WILL CONTINUE THURSDAY WITH MOST LOCATIONS REACHING THE MID
AND UPPER 70S THOUGH THERE WILL STILL BE AN EASTERLY COMPONENT TO
THE LOW LEVEL FLOW TO KEEP THE IL SHORELINE IN THE 60S.
TRS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* APPROACHING LINE OF STORMS / LARGE BOW ECHO ON WEATHER RADAR /
EXPECTED TO MOVE ACROSS REMAINDER OF NORTHERN ILLINOIS AND INTO
NORTHWEST INDIANA AND LAKE MICHIGAN THIS EVENING.
* GUST FRONT AHEAD OF LINE OF STORMS MAY PRODUCE WIND GUSTS AROUND
40 KTS WITH ISOLATED TO SCATTERED DAMAGING WIND GUSTS... IN
ADDITIONAL TO BRIEF TORRENTIAL RAINFALL.
* COVERAGE OF ISOLATED THUNDERSTORMS AHEAD OF APPROACHING LINE OF
STORMS WILL BE MINIMAL.
ED F
//DISCUSSION...UPDATED 00Z...
ACTIVE WEATHER PERIOD TO CONTINUE TONIGHT... FRIDAY... AND INTO
SATURDAY WITH SEVERAL PERIODS OF SHOWERS AND THUNDERSTORMS. THE
NEXT WILL COME IN THE FORM OF A LINE OF STORMS IN THE SHAPE OF A
LARGE BOW ECHO ON WEATHER RADAR. THIS BOW...ALBEIT SOMEWHAT RAGGED
IN APPEARANCE ON RADAR... WILL CONTINUE TO MARCH ACROSS THE AREA
THIS EVENING. SURFACE REPORTS SHOWING GUST FRONT WINDS AHEAD OF
THE LINE GENERALLY AROUND 40 KTS... WITH ISOLATED DAMAGING WIND
GUSTS TO 60 KTS ASSOCIATED WITH THE MOST INTENSE CELLS WITHIN THE
LINE.
EXTRAPOLATION OF LINE TIMES GUST FRONT/LEADING EDGE OF
THUNDERSTORMS TO RFD AROUND 0015Z... ORD 0130Z... AND MDW AROUND
0145Z. BRIEF (AROUND 20 MINUTE) PERIOD OF TORRENTIAL RAIN AND IFR
VISIBILITY POSSIBLE WITH ONSET OF STORMS... TO BE FOLLOWED BY A
LONGER PERIOD (1-2 HOURS) OF MORE MODERATE RAIN SHOWERS WITH
EMBEDDED THUNDER.
EXPECT BRAKE IN THE PRECIPITATION LATER INTO THE OVERNIGHT
EXTENDING INTO THE DAYTIME FRIDAY. NEXT APPROACHING UPPER LEVEL
DISTURBANCE WILL HELP TO ORGANIZE ANOTHER ROUND OF THUNDERSTORMS
FRIDAY AFTERNOON.
ED F
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* MEDIUM TO HIGH CONFIDENCE THAT APPROACHING LINE OF STORMS WILL
CONTINUE ACROSS NORTHERN ILLINOIS THIS EVENING.
* MEDIUM TO HIGH CONFIDENCE THAT LINE OF STORMS WILL MAINTAIN
INTENSITY AS IT MOVES EAST THROUGH 04Z.
* MEDIUM CONFIDENCE IN TIMING OF LINE OF TSTMS IMPACTING TERMINALS
AROUND MID EVENING.
* LOW CONFIDENCE IN STRENGTH OF WIND GUSTS TO BE EXPECTED AT
TERMINALS AS GUST FRONT WITH LINE OF STORMS ADVANCES.
* MEDIUM CONFIDENCE IN ADDITIONAL TSTMS FRIDAY...LOW CONFIDENCE
IN TIMING.
* MEDIUM TO HIGH CONFIDENCE IN WIND TRENDS.
ED F
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
* FRIDAY THROUGH SATURDAY...PERIODS OF TSRA/SHRA.
POSSIBLE WITH MVFR CIGS/VIS.
* SUNDAY...CHANCE OF SHRA EARLY...OTRW...VFR.
* MONDAY THROUGH EARLY TUESDAY...VFR. WX NIL.
* LATE TUESDAY THROUGH WEDNESDAY...CHANCE TSRA/SHRA.
KREIN
&&
.MARINE...
1259 PM CDT
THE SHORT TERM OF THE MARINE FORECAST HAS A SMALL CRAFT ADVISORY FOR
STRONG WINDS ACROSS THE ILLINOIS AND NORTHWEST INDIANA NEARSHORE
WATERS.
ACROSS THE OPEN WATERS OF THE LAKE...MAINLY THE NORTHERN THIRD OF
THE LAKE...AREAS OF DENSE FOG CONTINUE.
VERY WARM/MOIST AIR CONTINUES TO SLIDE NORTH ACROSS THE LAKE...AND
WITH THE MUCH COOLER LAKE SURFACE WATER...HAS RESULTED IN AREAS OF
DENSE FOG PERSISTING. IT DOES APPEAR BASED ON LATEST VISIBLE IMAGERY
THAT THE FOG HAS REMAINED FOCUSED ACROSS THE NORTHERN THIRD OF THE
LAKE. OBS HAVE CONTINUED TO SHOW INCREASING GUSTS...WITH SPEEDS
GENERALLY AROUND 20-25KT ACROSS THE SOUTHERN HALF OF THE LAKE.
FURTHER NORTH IT APPEARS THE WINDS ARE SLIGHTLY LESS...WITH SPEEDS
GENERALLY IN THE 15-25KT.
THE TROUGH OF LOW PRESSURE REMAINS CENTERED ACROSS THE CENTRAL
PLAINS...WITH A WEAK LOW PRESSURE LIFTING NORTH INTO THE NORTHERN
PLAINS. AN ASSOCIATED WARM FRONT EXTENDS EAST THROUGH THE UPPER
GREAT LAKES REGION. WITH THE POSITION OF THE LOW PRESSURE AND THE
PERSISTING RIDGE OF HIGH PRESSURE ACROSS THE SOUTHEASTERN UNITED
STATES...THE WIND FLOW WILL REMAIN SOUTHERLY ACROSS THE LAKE. AT
TIMES THROUGH EARLY THIS EVENING GUSTS MAY APPROACH 30 KT...MAINLY
FOR THE SOUTHERN PORTIONS OF THE LAKE INCLUDING THE NEARSHORE
WATERS. AS A RESULT WILL MAINTAIN THE CURRENT SMALL CRAFT ADVISORY
THAT IS IN EFFECT.
THE TROUGH OF LOW PRESSURE POSITIONED OVER THE CENTRAL PLAINS WILL
SLOWLY PUSH EAST...WITH A LOW PRESSURE APPROACHING THE WESTERN GREAT
LAKES SAT MIDDAY. THE RECENT FORECAST TRENDS HAVE BEEN TO SLOW THE
ARRIVAL OF THIS SYSTEM...THUS IT IS POSSIBLE THAT THE MAIN LOW
PRESSURE MAY NOT ARRIVE UNTIL CLOSER TO SAT NIGHT. THEN AN
ASSOCIATED COLD FRONT WILL WILL PUSH EAST ACROSS THE LAKE OVERNIGHT
SAT INTO SUN. WINDS AT THAT POINT WILL TURN WESTERLY THEN NORTHERLY
WITH MUCH COOLER AIR FLOWING OVER THE LAKE.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 7 PM SATURDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 7
PM SATURDAY.
LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565
UNTIL 7 AM FRIDAY.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
715 PM CDT THU MAY 30 2013
.MESOSCALE DISCUSSION...
715 PM CDT
WATER VAPOR IMAGERY CONTINUES TO DEPICT A RATHER STOUT MID LEVEL
DISTURBANCE RAPIDLY LIFTING NORTHEASTWARD ACROSS NORTHERN MISSOURI
AND INTO IOWA EARLY THIS EVENING. THIS FEATURE HAS BEEN DRIVING THE
STRONG LINE OF CONVECTION THROUGH THE LATE AFTERNOON ACROSS PORTIONS
OF EASTERN IOWA AND WESTERN ILLINOIS. THIS LINE DID SHOWN SOME
WEAKENING WITHIN THE LAST HOUR. HOWEVER...IN SPITE OF THIS...SHEAR
AND INSTABILITY SHOULD CONTINUE TO SUPPORT A SEVERE WIND
THREAT...ESPECIALLY ACROSS NORTH CENTRAL AND NORTHEASTERN ILLINOIS
OVER THE NEXT FEW HOURS. THERE WILL ALSO CONTINUE TO BE A SMALL
THREAT OF A BRIEF TORNADO SPIN-UP ALONG THE LINE AS 0-1 KM SRH
REMAINS ELEVATED. CORFIDI VECTORS ALSO SHOW THAT THE MAIN WIND
PRODUCING CONVECTIVE SEGMENTS WILL MOVE TO THE NORTH-NORTHEAST.
THEREFORE IT IS ANTICIPATED THE THE MAIN SEVERE THREAT WILL REMAIN
ACROSS NORTHERN ILLINOIS...MAINLY NORTH OF I-80.
KJB
&&
.DISCUSSION...
504 PM CDT
HAVE DECIDED TO EXPAND THE CURRENT FLASH FLOOD WATCH...TO INCLUDE
THE ENTIRE CWA.
WAS ON THE FENCE EARLIER WITH REGARDS TO EXPANDING THE CURRENT
FLASH FLOOD WATCH FOR THE REMAINDER OF THE CWA...BUT WITH LATEST
TRENDS THIS PAST AFTERNOON...HAVE DECIDED TO INCLUDE THE ENTIRE
CWA. THE THUNDERSTORMS THIS PAST AFTERNOON HAVE BEEN VERY GOOD
RAIN PRODUCERS...WHICH WILL LIKELY CONTINUE OVER THE NEXT COUPLE
OF HOURS AS PWATS REMAIN RATHER HIGH. ALSO...MONITORING THE
CONVECTIVE LINE TO THE WEST AND ITS MOVEMENT EAST INTO THE CWA.
LATEST TRENDS AND SHORT TERM GUIDANCE ARE HINTING AT THE
POSSIBILITY OF MORE TRAINING ACROSS THE CWA...WITH CURRENT FLOW IN
PLACE...DEFINITELY SEEMS REASONABLE.
RODRIGUEZ
//PREV DISCUSSION...
400 PM CDT
MAIN FORECAST CONCERNS REMAIN TIED TO THE ACTIVE WEATHER PATTERN
EXPECTED THROUGH THE START OF THE WEEKEND...WITH ROUNDS OF HEAVY
RAINFALL LIKELY AS WELL AS CONTINUED CHANCES FOR SEVERE WEATHER.
HAVE NOT EXPANDED THE FFA WATCH AT THIS TIME WITH MORE WIDESPREAD
HEAVY RAINFALL AND FLOODING NOT APPEARING LIKELY UNTIL LATER
FRIDAY AFTERNOON INTO FRIDAY NIGHT. THIS IS NOT TO SAY THAT
LOCALIZED FLOODING COULD NOT OCCUR WITH ANY POSSIBLE STRONG
THUNDERSTORMS TONIGHT. A MORE LIKELY SCENARIO AT THIS TIME IS WITH
THE CURRENT SCATTERED DEVELOPMENT TO BE REPLACED WITH A MORE
PROGRESSIVE AREA OF THUNDERSTORMS.
CURRENT ISOLATED TO SCATTERED ACTIVITY ACROSS THE CWA WILL
CONTINUE TO INCREASE IN COVERAGE THIS EVENING...AS LARGE SCALE
FORCING INCREASES WITH THE APPROACH A FAIRLY STOUT MID LEVEL WAVE
PROPAGATING NORTH THROUGH CENTRAL ILLINOIS. AREAS WHICH CONTINUE
TO BE FAVORED ARE LOCATIONS ALONG AND WEST OF A LINE FROM CRYSTAL
LAKE SOUTH TO GIBSON CITY IN ILLINOIS. LATEST RAP ANALYSIS SHOWS
MODERATE INSTABILITY IN PLACE WITH MLCAPE AROUND 2000 J/KG...AND
WITH MID/LOW LEVEL LAPSE RATES EXPECTED TO ONLY INCREASE OVER THE
NEXT COUPLE OF HOURS. THIS INCREASING FORCING AND INSTABILITY WILL
AID FURTHER DEVELOPMENT/EXPANSION OF CURRENT ACTIVITY ONGOING
ACROSS THE WESTERN HALF OF THE CWA. DEEP LAYER SHEAR REMAINS
MEAGER AT 25-30KT PRIMARILY OVER THE WESTERN CWA WHILE 0-1KM SHEAR
ALSO REMAINS HIGHEST ALONG OR JUST WEST OF THE CWA...ESPECIALLY
GOING INTO WESTERN ILLINOIS AND EASTERN IOWA.
HOWEVER...SHORT TERM GUIDANCE CONTINUES TO SHOW AN INCREASE IN
BOTH DEEP LAYER SHEAR AND LOW LEVEL SHEAR ACROSS THE CURRENT WATCH
AREA THROUGH THE REMAINDER OF THE AFTERNOON. THIS WILL HELP FOR
MORE ORGANIZED AND LONGER LIVED DEVELOPMENT ACROSS THE WESTERN
CWA...LEAVING THE THREAT OF HAIL/DAMAGING WINDS AS WELL AS
POSSIBLE TORNADOES. ALTHOUGH MORE ORGANIZED DEVELOPMENT IS MORE
LIKELY FOR THE WESTERN HALF OF THE CWA...SHORT TERM GUIDANCE IS
HINTING AT A SLIGHT INCREASE IN DEEP LAYER SHEAR MORE TOWARDS FAR
NORTHEAST ILLINOIS. THIS SLIGHT INCREASE COINCIDING WITH THE
CURRENT CAPE IN PLACE...COULD FAVOR SOME ISOLATED STRONGER
DEVELOPMENT IN THAT LOCATION IN THE NEXT COUPLE OF HOURS. WILL
NEED CONTINUE TO MONITOR DEVELOPMENT IN THAT LOCATION...WHICH
WOULD INCLUDE THE CITY OF CHICAGO/METRO AREA LATE THIS AFTERNOON
INTO THE EARLY EVENING...AS I COULD EASILY FORESEE AN UPSCALE IN
GROWTH IN BOTH INTENSITY AND COVERAGE.
EVEN IF THAT DOES NOT MATERIALIZE THROUGH LATE THIS
AFTERNOON...CONTINUE TO MONITOR A LARGER LINE OF THUNDERSTORMS
SITUATED FROM SOUTHERN IOWA SOUTH INTO MISSOURI. THIS LINE IS TIED
MORE CLOSELY TO FAIRLY STRONG MID LEVEL WAVE LIFTING NORTHEAST OUT
KANSAS AND ATTENDANT SURFACE TROUGH/BOUNDARY FROM IOWA INTO
MISSOURI. ALL GUIDANCE IS SHOWING THIS LINE OF THUNDERSTORMS
WILL INCREASE IN INTENSITY OVER THE NEXT COUPLE OF HOURS...WHICH
WOULD MAKE SENSE AS THIS LINE OF THUNDERSTORMS MOVES FURTHER
EAST/NORTHEAST INTO A MORE UNSTABLE ENVIRONMENT. STRONG FORCING
OWING TO LARGE SCALE SUPPORT AND LOW/MID LEVEL CONVERGENCE SHOULD
AID IN THIS LINE OF THUNDERSTORMS FURTHER BLOSSOMING AS IT MOVES
TOWARDS THE WESTERN ILLINOIS...ESPECIALLY AS DEEP LAYER SHEAR IS
ALSO INCREASING.
THERE IS STILL SOME UNCERTAINTY AS TO THE WHOLE EVOLUTION OF THIS
LINE OF THUNDERSTORMS AS IT WORKS ITS WAY TOWARDS NORTHERN
ILLINOIS THIS EVENING...MAINLY IN THE STRENGTH OF THIS COMPLEX AND
POTENTIAL SEVERE THREAT. ALTHOUGH THERE WILL BE SOME SLIGHT
DIMINISHING TREND WITH THE CURRENT INSTABILITY IN PLACE...FEEL
THAT IT WILL MORE THAN SUFFICE TO HELP KEEP THIS LINE SHIFTING
EAST. ALSO...SHORT TERM GUIDANCE IS INDICATING THAT 0-3KM BULK
SHEAR WILL INCREASE TOWARDS THE 00Z TIME FRAME THIS
EVENING...WHICH WOULD ACT TO HELP FOR ORGANIZATION AND INCREASE IN
THREAT FOR LINEAR STRUCTURES/STRONG DAMAGING WINDS. SO HAVE
TRENDED MORE PESSIMISTIC...WITH THINKING THAT THIS LINE AND STRONG
DAMAGING WINDS COULD MOVE ACROSS NORTHERN ILLINOIS THIS EVENING.
HAVE ALSO TRENDED MORE TOWARDS THE HRRR...WITH SYSTEM TIMING
THINKING THAT IT SHOULD BE KNOCKING ON THE WESTERN CWA DOORSTEPS
BY 00-01Z AND THEN CONTINUE EAST TOWARDS NORTHEAST ILLINOIS
THROUGH THE SEVERAL HOURS THERE AFTER. BEYOND THAT TIME
FRAME...CONFIDENCE LOWERS WITH REGARDS TO THE STRENGTH OF THIS
SYSTEM. NONETHELESS...HEAVY RAINFALL AND FLASH FLOODING COULD
BECOME ISSUES OVERNIGHT TONIGHT ESPECIALLY AS PWATS ARE AT OR JUST
ABOVE 1.7 INCHES AND 850MB DEW POINTS REMAIN RATHER HIGH.
THUNDERSTORM COMPLEX IS THEN EXPECTED TO SHIFT EAST OF THE CWA BY
EARLY FRIDAY MORNING...WITH A DRYING TREND EXPECTED DURING THAT
TIME FRAME. THIS SHOULD NOT LAST TOO LONG WITH DRY CONDITIONS ONLY
EXPECTED THROUGH MID DAY AS ATTENTION QUICKLY SHIFTS BACK WEST
WITH THE APPROACH OF ANOTHER STRONG MID LEVEL WAVE EJECTING OUT OF
THE CENTRAL PLAINS. YET AGAIN...A SEVERE THREAT WILL BE IN PLACE
ON FRIDAY WITH GROWING CONCERNS OF MORE POTENTIAL FLOODING FROM
THIS POINT ON...INTO FRIDAY NIGHT AND SATURDAY. THE SEVERE THREAT
WILL LIKELY AFFECT THE ENTIRE CWA ON FRIDAY AND WITH CLEARING
ANTICIPATED FRIDAY MORNING...INSTABILITY IS EXPECTED TO RAPIDLY
INCREASE BY LATE MORNING WITH MODERATE TO STRONG INSTABILITY
LIKELY IN PLACE ACROSS THE CWA. STRONG DEEP LAYER SHEAR IN UPWARDS
OF 50-60KT WILL EASILY SUPPORT WIDESPREAD ORGANIZED DEVELOPMENT AS
SOON AS EARLY AFTERNOON ON FRIDAY. STRONG DAMAGING WINDS AND HAIL
ARE THE MAIN THREAT...BUT WITH SREF GUIDANCE INDICATING ELEMENTS
CORRESPONDING TO SUPERCELLULAR STRUCTURES OR ROTATING
THUNDERSTORMS COULD COME TOGETHER ACROSS THE CWA. WILL NEED TO
CONTINUE TO MONITOR THIS TIME FRAME AS WELL...AS WIDESPREAD SEVERE
IS APPEARING LIKELY ONCE AGAIN. GOING INTO FRIDAY NIGHT...HEAVY
RAINFALL APPEARS LIKELY WITH SEVERAL STRONG WAVES PROPAGATING
NORTHEAST ACROSS THE CWA PROVIDING CONTINUED DEVELOPMENT AS WELL
AS A STRONG LLJ ORIENTED TOWARDS NORTHEAST ILLINOIS...PUMPING HIGH
THETAE AIR INTO THE REGION.
RODRIGUEZ
EXTENDED PERIOD...SUNDAY THROUGH THURSDAY...
BY DAYBREAK SUNDAY THE UPPER RIDGE IS TO HAVE PROGRESSED EASTWARD
TO OVER THE UPPER MIDWEST AND MID MS VALLEY WITH A SURFACE
TROUGH/SECONDARY COLD FRONT JUST TO THE NORTHWEST AND NORTH OF THE
LOCAL FORECAST AREA. THIS TROUGH/FRONT IS PROGGED TO MOVE ACROSS ALL
OF THE FA DURING THE SUNDAY MORNING AS THE UPPER TROUGH CONTINUES ON
TO OVER THE UPPER GREAT LAKES AND LOWER OH VALLEY BY EVENING. UNTIL
THE TROUGH AXIS MOVES A BIT FURTHER EAST OF THE IMMEDIATE AREA THERE
WILL BE A LINGERING CHANCE OF SHOWERS DURING SUNDAY MORNING.
THE SECONDARY COLD FRONT WILL REINFORCE THE COLD AIR ADVECTION THAT
WILL HAVE STARTED TO OCCUR LATE SATURDAY AND SATURDAY NIGHT WITH THE
INITIAL COLD FRONT. BETWEEN THE PAIR OF FRONT 850HPA TEMPERATURES
ARE PROGGED TO FALL AROUND 10 DEGREES C FROM 18Z SATURDAY TO 00Z
MONDAY......DOWN TO AROUND +4 OR +5C. WITH COOL HIGH PRESSURE
BUILDING OVER THE AREA TEMPERATURES WILL BE COOL SUNDAY AND MONDAY
WITH HIGHS ONLY IN THE 60S...WITH LAKESIDE MAX TEMPERATURES LIKELY
TO ONLY BE IN THE 55-60F RANGE AS A LONG FETCH DOWN LAKE MICHIGAN
BRINGS AIR ADDITIONALLY COOLED BY THE STILL CHILLY LAKE ASHORE
SUNDAY. WHILE THE SURFACE RIDGE AXIS WILL BE MOVING OVER WI AND
WESTERN IL DURING MONDAY ALLOWING WINDS TO SLACKEN...A WEAK NE
SYNOPTIC FLOW WILL STILL BE IN PLACE AIDED BY A LAKE BREEZE.
THE FURTHER EASTWARD PROGRESS OF THE UPPER TROUGH IS TO BE SLOW AS A
CLOSED LOW TO FORM OVER SOUTHERN HUDSON BAY/NORTHERN ONTARIO IS
PROGGED TO BE DROP SOUTH...THEN SOUTHEAST AND EAST OVER ONTARIO
SATURDAY NIGHT THROUGH MONDAY NIGHT. AS THE UPPER TROUGH/LOW MOVES
FURTHER EAST A WEAK UPPER RIDGE WILL MOVE OVER THE REGION TUESDAY AS
ANOTHER UPPER LOW MOVES EAST OVER THE FAR SOUTHERN CANADIAN
PRAIRIE/FAR NORTHERN PLAINS. THIS WILL ALLOW A BIT OF MODERATION IN
TEMPERATURES TUESDAY AND WEDNESDAY AS EAST-SOUTHEAST WINDS BECOMES
SOUTHEASTERLY AND INCREASING THOUGH THIS LOW LEVEL FLOW WILL KEEP
THE IL SHORE...ESPECIALLY THE FAR NORTHERN PART....STILL CHILLY.
INLAND AREAS SHOULD PEAK IN THE UPPER 60S AND LOWER 70S TUESDAY...
AND A COUPLE DEGREES WARMER WEDNESDAY. WITH CONTINUED WARM AIR
ADVECTION AHEAD OF THE APPROACHING UPPER LOW/TROUGH THE WARMING
TREND WILL CONTINUE THURSDAY WITH MOST LOCATIONS REACHING THE MID
AND UPPER 70S THOUGH THERE WILL STILL BE AN EASTERLY COMPONENT TO
THE LOW LEVEL FLOW TO KEEP THE IL SHORELINE IN THE 60S.
TRS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* APPROACHING LINE OF STORMS / LARGE BOW ECHO ON WEATHER RADAR /
EXPECTED TO MOVE ACROSS REMAINDER OF NORTHERN ILLINOIS AND INTO
NORTHWEST INDIANA AND LAKE MICHIGAN THIS EVENING.
* GUST FRONT AHEAD OF LINE OF STORMS MAY PRODUCE WIND GUSTS AROUND
40 KTS WITH ISOLATED TO SCATTERED DAMAGING WIND GUSTS... IN
ADDITIONAL TO BRIEF TORRENTIAL RAINFALL.
* COVERAGE OF ISOLATED THUNDERSTORMS AHEAD OF APPROACHING LINE OF
STORMS WILL BE MINIMAL.
ED F
//DISCUSSION...UPDATED 00Z...
ACTIVE WEATHER PERIOD TO CONTINUE TONIGHT... FRIDAY... AND INTO
SATURDAY WITH SEVERAL PERIODS OF SHOWERS AND THUNDERSTORMS. THE
NEXT WILL COME IN THE FORM OF A LINE OF STORMS IN THE SHAPE OF A
LARGE BOW ECHO ON WEATHER RADAR. THIS BOW...ALBEIT SOMEWHAT RAGGED
IN APPEARANCE ON RADAR... WILL CONTINUE TO MARCH ACROSS THE AREA
THIS EVENING. SURFACE REPORTS SHOWING GUST FRONT WINDS AHEAD OF
THE LINE GENERALLY AROUND 40 KTS... WITH ISOLATED DAMAGING WIND
GUSTS TO 60 KTS ASSOCIATED WITH THE MOST INTENSE CELLS WITHIN THE
LINE.
EXTRAPOLATION OF LINE TIMES GUST FRONT/LEADING EDGE OF
THUNDERSTORMS TO RFD AROUND 0015Z... ORD 0130Z... AND MDW AROUND
0145Z. BRIEF (AROUND 20 MINUTE) PERIOD OF TORRENTIAL RAIN AND IFR
VISIBILITY POSSIBLE WITH ONSET OF STORMS... TO BE FOLLOWED BY A
LONGER PERIOD (1-2 HOURS) OF MORE MODERATE RAIN SHOWERS WITH
EMBEDDED THUNDER.
EXPECT BRAKE IN THE PRECIPITATION LATER INTO THE OVERNIGHT
EXTENDING INTO THE DAYTIME FRIDAY. NEXT APPROACHING UPPER LEVEL
DISTURBANCE WILL HELP TO ORGANIZE ANOTHER ROUND OF THUNDERSTORMS
FRIDAY AFTERNOON.
ED F
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* MEDIUM TO HIGH CONFIDENCE THAT APPROACHING LINE OF STORMS WILL
CONTINUE ACROSS NORTHERN ILLINOIS THIS EVENING.
* MEDIUM TO HIGH CONFIDENCE THAT LINE OF STORMS WILL MAINTAIN
INTENSITY AS IT MOVES EAST THROUGH 04Z.
* MEDIUM CONFIDENCE IN TIMING OF LINE OF TSTMS IMPACTING TERMINALS
AROUND MID EVENING.
* LOW CONFIDENCE IN STRENGTH OF WIND GUSTS TO BE EXPECTED AT
TERMINALS AS GUST FRONT WITH LINE OF STORMS ADVANCES.
* MEDIUM CONFIDENCE IN ADDITIONAL TSTMS FRIDAY...LOW CONFIDENCE
IN TIMING.
* MEDIUM TO HIGH CONFIDENCE IN WIND TRENDS.
ED F
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
* FRIDAY THROUGH SATURDAY...PERIODS OF TSRA/SHRA.
POSSIBLE WITH MVFR CIGS/VIS.
* SUNDAY...CHANCE OF SHRA EARLY...OTRW...VFR.
* MONDAY THROUGH EARLY TUESDAY...VFR. WX NIL.
* LATE TUESDAY THROUGH WEDNESDAY...CHANCE TSRA/SHRA.
KREIN
&&
.MARINE...
1259 PM CDT
THE SHORT TERM OF THE MARINE FORECAST HAS A SMALL CRAFT ADVISORY FOR
STRONG WINDS ACROSS THE ILLINOIS AND NORTHWEST INDIANA NEARSHORE
WATERS.
ACROSS THE OPEN WATERS OF THE LAKE...MAINLY THE NORTHERN THIRD OF
THE LAKE...AREAS OF DENSE FOG CONTINUE.
VERY WARM/MOIST AIR CONTINUES TO SLIDE NORTH ACROSS THE LAKE...AND
WITH THE MUCH COOLER LAKE SURFACE WATER...HAS RESULTED IN AREAS OF
DENSE FOG PERSISTING. IT DOES APPEAR BASED ON LATEST VISIBLE IMAGERY
THAT THE FOG HAS REMAINED FOCUSED ACROSS THE NORTHERN THIRD OF THE
LAKE. OBS HAVE CONTINUED TO SHOW INCREASING GUSTS...WITH SPEEDS
GENERALLY AROUND 20-25KT ACROSS THE SOUTHERN HALF OF THE LAKE.
FURTHER NORTH IT APPEARS THE WINDS ARE SLIGHTLY LESS...WITH SPEEDS
GENERALLY IN THE 15-25KT.
THE TROUGH OF LOW PRESSURE REMAINS CENTERED ACROSS THE CENTRAL
PLAINS...WITH A WEAK LOW PRESSURE LIFTING NORTH INTO THE NORTHERN
PLAINS. AN ASSOCIATED WARM FRONT EXTENDS EAST THROUGH THE UPPER
GREAT LAKES REGION. WITH THE POSITION OF THE LOW PRESSURE AND THE
PERSISTING RIDGE OF HIGH PRESSURE ACROSS THE SOUTHEASTERN UNITED
STATES...THE WIND FLOW WILL REMAIN SOUTHERLY ACROSS THE LAKE. AT
TIMES THROUGH EARLY THIS EVENING GUSTS MAY APPROACH 30 KT...MAINLY
FOR THE SOUTHERN PORTIONS OF THE LAKE INCLUDING THE NEARSHORE
WATERS. AS A RESULT WILL MAINTAIN THE CURRENT SMALL CRAFT ADVISORY
THAT IS IN EFFECT.
THE TROUGH OF LOW PRESSURE POSITIONED OVER THE CENTRAL PLAINS WILL
SLOWLY PUSH EAST...WITH A LOW PRESSURE APPROACHING THE WESTERN GREAT
LAKES SAT MIDDAY. THE RECENT FORECAST TRENDS HAVE BEEN TO SLOW THE
ARRIVAL OF THIS SYSTEM...THUS IT IS POSSIBLE THAT THE MAIN LOW
PRESSURE MAY NOT ARRIVE UNTIL CLOSER TO SAT NIGHT. THEN AN
ASSOCIATED COLD FRONT WILL WILL PUSH EAST ACROSS THE LAKE OVERNIGHT
SAT INTO SUN. WINDS AT THAT POINT WILL TURN WESTERLY THEN NORTHERLY
WITH MUCH COOLER AIR FLOWING OVER THE LAKE.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 7 PM SATURDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 7
PM SATURDAY.
LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565
UNTIL 7 AM FRIDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 9 PM THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
645 PM CDT THU MAY 30 2013
.DISCUSSION...
504 PM CDT
HAVE DECIDED TO EXPAND THE CURRENT FLASH FLOOD WATCH...TO INCLUDE
THE ENTIRE CWA.
WAS ON THE FENCE EARLIER WITH REGARDS TO EXPANDING THE CURRENT
FLASH FLOOD WATCH FOR THE REMAINDER OF THE CWA...BUT WITH LATEST
TRENDS THIS PAST AFTERNOON...HAVE DECIDED TO INCLUDE THE ENTIRE
CWA. THE THUNDERSTORMS THIS PAST AFTERNOON HAVE BEEN VERY GOOD
RAIN PRODUCERS...WHICH WILL LIKELY CONTINUE OVER THE NEXT COUPLE
OF HOURS AS PWATS REMAIN RATHER HIGH. ALSO...MONITORING THE
CONVECTIVE LINE TO THE WEST AND ITS MOVEMENT EAST INTO THE CWA.
LATEST TRENDS AND SHORT TERM GUIDANCE ARE HINTING AT THE
POSSIBILITY OF MORE TRAINING ACROSS THE CWA...WITH CURRENT FLOW IN
PLACE...DEFINITELY SEEMS REASONABLE.
RODRIGUEZ
//PREV DISCUSSION...
400 PM CDT
MAIN FORECAST CONCERNS REMAIN TIED TO THE ACTIVE WEATHER PATTERN
EXPECTED THROUGH THE START OF THE WEEKEND...WITH ROUNDS OF HEAVY
RAINFALL LIKELY AS WELL AS CONTINUED CHANCES FOR SEVERE WEATHER.
HAVE NOT EXPANDED THE FFA WATCH AT THIS TIME WITH MORE WIDESPREAD
HEAVY RAINFALL AND FLOODING NOT APPEARING LIKELY UNTIL LATER
FRIDAY AFTERNOON INTO FRIDAY NIGHT. THIS IS NOT TO SAY THAT
LOCALIZED FLOODING COULD NOT OCCUR WITH ANY POSSIBLE STRONG
THUNDERSTORMS TONIGHT. A MORE LIKELY SCENARIO AT THIS TIME IS WITH
THE CURRENT SCATTERED DEVELOPMENT TO BE REPLACED WITH A MORE
PROGRESSIVE AREA OF THUNDERSTORMS.
CURRENT ISOLATED TO SCATTERED ACTIVITY ACROSS THE CWA WILL
CONTINUE TO INCREASE IN COVERAGE THIS EVENING...AS LARGE SCALE
FORCING INCREASES WITH THE APPROACH A FAIRLY STOUT MID LEVEL WAVE
PROPAGATING NORTH THROUGH CENTRAL ILLINOIS. AREAS WHICH CONTINUE
TO BE FAVORED ARE LOCATIONS ALONG AND WEST OF A LINE FROM CRYSTAL
LAKE SOUTH TO GIBSON CITY IN ILLINOIS. LATEST RAP ANALYSIS SHOWS
MODERATE INSTABILITY IN PLACE WITH MLCAPE AROUND 2000 J/KG...AND
WITH MID/LOW LEVEL LAPSE RATES EXPECTED TO ONLY INCREASE OVER THE
NEXT COUPLE OF HOURS. THIS INCREASING FORCING AND INSTABILITY WILL
AID FURTHER DEVELOPMENT/EXPANSION OF CURRENT ACTIVITY ONGOING
ACROSS THE WESTERN HALF OF THE CWA. DEEP LAYER SHEAR REMAINS
MEAGER AT 25-30KT PRIMARILY OVER THE WESTERN CWA WHILE 0-1KM SHEAR
ALSO REMAINS HIGHEST ALONG OR JUST WEST OF THE CWA...ESPECIALLY
GOING INTO WESTERN ILLINOIS AND EASTERN IOWA.
HOWEVER...SHORT TERM GUIDANCE CONTINUES TO SHOW AN INCREASE IN
BOTH DEEP LAYER SHEAR AND LOW LEVEL SHEAR ACROSS THE CURRENT WATCH
AREA THROUGH THE REMAINDER OF THE AFTERNOON. THIS WILL HELP FOR
MORE ORGANIZED AND LONGER LIVED DEVELOPMENT ACROSS THE WESTERN
CWA...LEAVING THE THREAT OF HAIL/DAMAGING WINDS AS WELL AS
POSSIBLE TORNADOES. ALTHOUGH MORE ORGANIZED DEVELOPMENT IS MORE
LIKELY FOR THE WESTERN HALF OF THE CWA...SHORT TERM GUIDANCE IS
HINTING AT A SLIGHT INCREASE IN DEEP LAYER SHEAR MORE TOWARDS FAR
NORTHEAST ILLINOIS. THIS SLIGHT INCREASE COINCIDING WITH THE
CURRENT CAPE IN PLACE...COULD FAVOR SOME ISOLATED STRONGER
DEVELOPMENT IN THAT LOCATION IN THE NEXT COUPLE OF HOURS. WILL
NEED CONTINUE TO MONITOR DEVELOPMENT IN THAT LOCATION...WHICH
WOULD INCLUDE THE CITY OF CHICAGO/METRO AREA LATE THIS AFTERNOON
INTO THE EARLY EVENING...AS I COULD EASILY FORESEE AN UPSCALE IN
GROWTH IN BOTH INTENSITY AND COVERAGE.
EVEN IF THAT DOES NOT MATERIALIZE THROUGH LATE THIS
AFTERNOON...CONTINUE TO MONITOR A LARGER LINE OF THUNDERSTORMS
SITUATED FROM SOUTHERN IOWA SOUTH INTO MISSOURI. THIS LINE IS TIED
MORE CLOSELY TO FAIRLY STRONG MID LEVEL WAVE LIFTING NORTHEAST OUT
KANSAS AND ATTENDANT SURFACE TROUGH/BOUNDARY FROM IOWA INTO
MISSOURI. ALL GUIDANCE IS SHOWING THIS LINE OF THUNDERSTORMS
WILL INCREASE IN INTENSITY OVER THE NEXT COUPLE OF HOURS...WHICH
WOULD MAKE SENSE AS THIS LINE OF THUNDERSTORMS MOVES FURTHER
EAST/NORTHEAST INTO A MORE UNSTABLE ENVIRONMENT. STRONG FORCING
OWING TO LARGE SCALE SUPPORT AND LOW/MID LEVEL CONVERGENCE SHOULD
AID IN THIS LINE OF THUNDERSTORMS FURTHER BLOSSOMING AS IT MOVES
TOWARDS THE WESTERN ILLINOIS...ESPECIALLY AS DEEP LAYER SHEAR IS
ALSO INCREASING.
THERE IS STILL SOME UNCERTAINTY AS TO THE WHOLE EVOLUTION OF THIS
LINE OF THUNDERSTORMS AS IT WORKS ITS WAY TOWARDS NORTHERN
ILLINOIS THIS EVENING...MAINLY IN THE STRENGTH OF THIS COMPLEX AND
POTENTIAL SEVERE THREAT. ALTHOUGH THERE WILL BE SOME SLIGHT
DIMINISHING TREND WITH THE CURRENT INSTABILITY IN PLACE...FEEL
THAT IT WILL MORE THAN SUFFICE TO HELP KEEP THIS LINE SHIFTING
EAST. ALSO...SHORT TERM GUIDANCE IS INDICATING THAT 0-3KM BULK
SHEAR WILL INCREASE TOWARDS THE 00Z TIME FRAME THIS
EVENING...WHICH WOULD ACT TO HELP FOR ORGANIZATION AND INCREASE IN
THREAT FOR LINEAR STRUCTURES/STRONG DAMAGING WINDS. SO HAVE
TRENDED MORE PESSIMISTIC...WITH THINKING THAT THIS LINE AND STRONG
DAMAGING WINDS COULD MOVE ACROSS NORTHERN ILLINOIS THIS EVENING.
HAVE ALSO TRENDED MORE TOWARDS THE HRRR...WITH SYSTEM TIMING
THINKING THAT IT SHOULD BE KNOCKING ON THE WESTERN CWA DOORSTEPS
BY 00-01Z AND THEN CONTINUE EAST TOWARDS NORTHEAST ILLINOIS
THROUGH THE SEVERAL HOURS THERE AFTER. BEYOND THAT TIME
FRAME...CONFIDENCE LOWERS WITH REGARDS TO THE STRENGTH OF THIS
SYSTEM. NONETHELESS...HEAVY RAINFALL AND FLASH FLOODING COULD
BECOME ISSUES OVERNIGHT TONIGHT ESPECIALLY AS PWATS ARE AT OR JUST
ABOVE 1.7 INCHES AND 850MB DEW POINTS REMAIN RATHER HIGH.
THUNDERSTORM COMPLEX IS THEN EXPECTED TO SHIFT EAST OF THE CWA BY
EARLY FRIDAY MORNING...WITH A DRYING TREND EXPECTED DURING THAT
TIME FRAME. THIS SHOULD NOT LAST TOO LONG WITH DRY CONDITIONS ONLY
EXPECTED THROUGH MID DAY AS ATTENTION QUICKLY SHIFTS BACK WEST
WITH THE APPROACH OF ANOTHER STRONG MID LEVEL WAVE EJECTING OUT OF
THE CENTRAL PLAINS. YET AGAIN...A SEVERE THREAT WILL BE IN PLACE
ON FRIDAY WITH GROWING CONCERNS OF MORE POTENTIAL FLOODING FROM
THIS POINT ON...INTO FRIDAY NIGHT AND SATURDAY. THE SEVERE THREAT
WILL LIKELY AFFECT THE ENTIRE CWA ON FRIDAY AND WITH CLEARING
ANTICIPATED FRIDAY MORNING...INSTABILITY IS EXPECTED TO RAPIDLY
INCREASE BY LATE MORNING WITH MODERATE TO STRONG INSTABILITY
LIKELY IN PLACE ACROSS THE CWA. STRONG DEEP LAYER SHEAR IN UPWARDS
OF 50-60KT WILL EASILY SUPPORT WIDESPREAD ORGANIZED DEVELOPMENT AS
SOON AS EARLY AFTERNOON ON FRIDAY. STRONG DAMAGING WINDS AND HAIL
ARE THE MAIN THREAT...BUT WITH SREF GUIDANCE INDICATING ELEMENTS
CORRESPONDING TO SUPERCELLULAR STRUCTURES OR ROTATING
THUNDERSTORMS COULD COME TOGETHER ACROSS THE CWA. WILL NEED TO
CONTINUE TO MONITOR THIS TIME FRAME AS WELL...AS WIDESPREAD SEVERE
IS APPEARING LIKELY ONCE AGAIN. GOING INTO FRIDAY NIGHT...HEAVY
RAINFALL APPEARS LIKELY WITH SEVERAL STRONG WAVES PROPAGATING
NORTHEAST ACROSS THE CWA PROVIDING CONTINUED DEVELOPMENT AS WELL
AS A STRONG LLJ ORIENTED TOWARDS NORTHEAST ILLINOIS...PUMPING HIGH
THETAE AIR INTO THE REGION.
RODRIGUEZ
EXTENDED PERIOD...SUNDAY THROUGH THURSDAY...
BY DAYBREAK SUNDAY THE UPPER RIDGE IS TO HAVE PROGRESSED EASTWARD
TO OVER THE UPPER MIDWEST AND MID MS VALLEY WITH A SURFACE
TROUGH/SECONDARY COLD FRONT JUST TO THE NORTHWEST AND NORTH OF THE
LOCAL FORECAST AREA. THIS TROUGH/FRONT IS PROGGED TO MOVE ACROSS ALL
OF THE FA DURING THE SUNDAY MORNING AS THE UPPER TROUGH CONTINUES ON
TO OVER THE UPPER GREAT LAKES AND LOWER OH VALLEY BY EVENING. UNTIL
THE TROUGH AXIS MOVES A BIT FURTHER EAST OF THE IMMEDIATE AREA THERE
WILL BE A LINGERING CHANCE OF SHOWERS DURING SUNDAY MORNING.
THE SECONDARY COLD FRONT WILL REINFORCE THE COLD AIR ADVECTION THAT
WILL HAVE STARTED TO OCCUR LATE SATURDAY AND SATURDAY NIGHT WITH THE
INITIAL COLD FRONT. BETWEEN THE PAIR OF FRONT 850HPA TEMPERATURES
ARE PROGGED TO FALL AROUND 10 DEGREES C FROM 18Z SATURDAY TO 00Z
MONDAY......DOWN TO AROUND +4 OR +5C. WITH COOL HIGH PRESSURE
BUILDING OVER THE AREA TEMPERATURES WILL BE COOL SUNDAY AND MONDAY
WITH HIGHS ONLY IN THE 60S...WITH LAKESIDE MAX TEMPERATURES LIKELY
TO ONLY BE IN THE 55-60F RANGE AS A LONG FETCH DOWN LAKE MICHIGAN
BRINGS AIR ADDITIONALLY COOLED BY THE STILL CHILLY LAKE ASHORE
SUNDAY. WHILE THE SURFACE RIDGE AXIS WILL BE MOVING OVER WI AND
WESTERN IL DURING MONDAY ALLOWING WINDS TO SLACKEN...A WEAK NE
SYNOPTIC FLOW WILL STILL BE IN PLACE AIDED BY A LAKE BREEZE.
THE FURTHER EASTWARD PROGRESS OF THE UPPER TROUGH IS TO BE SLOW AS A
CLOSED LOW TO FORM OVER SOUTHERN HUDSON BAY/NORTHERN ONTARIO IS
PROGGED TO BE DROP SOUTH...THEN SOUTHEAST AND EAST OVER ONTARIO
SATURDAY NIGHT THROUGH MONDAY NIGHT. AS THE UPPER TROUGH/LOW MOVES
FURTHER EAST A WEAK UPPER RIDGE WILL MOVE OVER THE REGION TUESDAY AS
ANOTHER UPPER LOW MOVES EAST OVER THE FAR SOUTHERN CANADIAN
PRAIRIE/FAR NORTHERN PLAINS. THIS WILL ALLOW A BIT OF MODERATION IN
TEMPERATURES TUESDAY AND WEDNESDAY AS EAST-SOUTHEAST WINDS BECOMES
SOUTHEASTERLY AND INCREASING THOUGH THIS LOW LEVEL FLOW WILL KEEP
THE IL SHORE...ESPECIALLY THE FAR NORTHERN PART....STILL CHILLY.
INLAND AREAS SHOULD PEAK IN THE UPPER 60S AND LOWER 70S TUESDAY...
AND A COUPLE DEGREES WARMER WEDNESDAY. WITH CONTINUED WARM AIR
ADVECTION AHEAD OF THE APPROACHING UPPER LOW/TROUGH THE WARMING
TREND WILL CONTINUE THURSDAY WITH MOST LOCATIONS REACHING THE MID
AND UPPER 70S THOUGH THERE WILL STILL BE AN EASTERLY COMPONENT TO
THE LOW LEVEL FLOW TO KEEP THE IL SHORELINE IN THE 60S.
TRS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* APPROACHING LINE OF STORMS / LARGE BOW ECHO ON WEATHER RADAR /
EXPECTED TO MOVE ACROSS REMAINDER OF NORTHERN ILLINOIS AND INTO
NORTHWEST INDIANA AND LAKE MICHIGAN THIS EVENING.
* GUST FRONT AHEAD OF LINE OF STORMS MAY PRODUCE WIND GUSTS AROUND
40 KTS WITH ISOLATED TO SCATTERED DAMAGING WIND GUSTS... IN
ADDITIONAL TO BRIEF TORRENTIAL RAINFALL.
* COVERAGE OF ISOLATED THUNDERSTORMS AHEAD OF APPROACHING LINE OF
STORMS WILL BE MINIMAL.
ED F
//DISCUSSION...UPDATED 00Z...
ACTIVE WEATHER PERIOD TO CONTINUE TONIGHT... FRIDAY... AND INTO
SATURDAY WITH SEVERAL PERIODS OF SHOWERS AND THUNDERSTORMS. THE
NEXT WILL COME IN THE FORM OF A LINE OF STORMS IN THE SHAPE OF A
LARGE BOW ECHO ON WEATHER RADAR. THIS BOW...ALBEIT SOMEWHAT RAGGED
IN APPEARANCE ON RADAR... WILL CONTINUE TO MARCH ACROSS THE AREA
THIS EVENING. SURFACE REPORTS SHOWING GUST FRONT WINDS AHEAD OF
THE LINE GENERALLY AROUND 40 KTS... WITH ISOLATED DAMAGING WIND
GUSTS TO 60 KTS ASSOCIATED WITH THE MOST INTENSE CELLS WITHIN THE
LINE.
EXTRAPOLATION OF LINE TIMES GUST FRONT/LEADING EDGE OF
THUNDERSTORMS TO RFD AROUND 0015Z... ORD 0130Z... AND MDW AROUND
0145Z. BRIEF (AROUND 20 MINUTE) PERIOD OF TORRENTIAL RAIN AND IFR
VISIBILITY POSSIBLE WITH ONSET OF STORMS... TO BE FOLLOWED BY A
LONGER PERIOD (1-2 HOURS) OF MORE MODERATE RAIN SHOWERS WITH
EMBEDDED THUNDER.
EXPECT BRAKE IN THE PRECIPITATION LATER INTO THE OVERNIGHT
EXTENDING INTO THE DAYTIME FRIDAY. NEXT APPROACHING UPPER LEVEL
DISTURBANCE WILL HELP TO ORGANIZE ANOTHER ROUND OF THUNDERSTORMS
FRIDAY AFTERNOON.
ED F
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* MEDIUM TO HIGH CONFIDENCE THAT APPROACHING LINE OF STORMS WILL
CONTINUE ACROSS NORTHERN ILLINOIS THIS EVENING.
* MEDIUM TO HIGH CONFIDENCE THAT LINE OF STORMS WILL MAINTAIN
INTENSITY AS IT MOVES EAST THROUGH 04Z.
* MEDIUM CONFIDENCE IN TIMING OF LINE OF TSTMS IMPACTING TERMINALS
AROUND MID EVENING.
* LOW CONFIDENCE IN STRENGTH OF WIND GUSTS TO BE EXPECTED AT
TERMINALS AS GUST FRONT WITH LINE OF STORMS ADVANCES.
* MEDIUM CONFIDENCE IN ADDITIONAL TSTMS FRIDAY...LOW CONFIDENCE
IN TIMING.
* MEDIUM TO HIGH CONFIDENCE IN WIND TRENDS.
ED F
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
* FRIDAY THROUGH SATURDAY...PERIODS OF TSRA/SHRA.
POSSIBLE WITH MVFR CIGS/VIS.
* SUNDAY...CHANCE OF SHRA EARLY...OTRW...VFR.
* MONDAY THROUGH EARLY TUESDAY...VFR. WX NIL.
* LATE TUESDAY THROUGH WEDNESDAY...CHANCE TSRA/SHRA.
KREIN
&&
.MARINE...
1259 PM CDT
THE SHORT TERM OF THE MARINE FORECAST HAS A SMALL CRAFT ADVISORY FOR
STRONG WINDS ACROSS THE ILLINOIS AND NORTHWEST INDIANA NEARSHORE
WATERS.
ACROSS THE OPEN WATERS OF THE LAKE...MAINLY THE NORTHERN THIRD OF
THE LAKE...AREAS OF DENSE FOG CONTINUE.
VERY WARM/MOIST AIR CONTINUES TO SLIDE NORTH ACROSS THE LAKE...AND
WITH THE MUCH COOLER LAKE SURFACE WATER...HAS RESULTED IN AREAS OF
DENSE FOG PERSISTING. IT DOES APPEAR BASED ON LATEST VISIBLE IMAGERY
THAT THE FOG HAS REMAINED FOCUSED ACROSS THE NORTHERN THIRD OF THE
LAKE. OBS HAVE CONTINUED TO SHOW INCREASING GUSTS...WITH SPEEDS
GENERALLY AROUND 20-25KT ACROSS THE SOUTHERN HALF OF THE LAKE.
FURTHER NORTH IT APPEARS THE WINDS ARE SLIGHTLY LESS...WITH SPEEDS
GENERALLY IN THE 15-25KT.
THE TROUGH OF LOW PRESSURE REMAINS CENTERED ACROSS THE CENTRAL
PLAINS...WITH A WEAK LOW PRESSURE LIFTING NORTH INTO THE NORTHERN
PLAINS. AN ASSOCIATED WARM FRONT EXTENDS EAST THROUGH THE UPPER
GREAT LAKES REGION. WITH THE POSITION OF THE LOW PRESSURE AND THE
PERSISTING RIDGE OF HIGH PRESSURE ACROSS THE SOUTHEASTERN UNITED
STATES...THE WIND FLOW WILL REMAIN SOUTHERLY ACROSS THE LAKE. AT
TIMES THROUGH EARLY THIS EVENING GUSTS MAY APPROACH 30 KT...MAINLY
FOR THE SOUTHERN PORTIONS OF THE LAKE INCLUDING THE NEARSHORE
WATERS. AS A RESULT WILL MAINTAIN THE CURRENT SMALL CRAFT ADVISORY
THAT IS IN EFFECT.
THE TROUGH OF LOW PRESSURE POSITIONED OVER THE CENTRAL PLAINS WILL
SLOWLY PUSH EAST...WITH A LOW PRESSURE APPROACHING THE WESTERN GREAT
LAKES SAT MIDDAY. THE RECENT FORECAST TRENDS HAVE BEEN TO SLOW THE
ARRIVAL OF THIS SYSTEM...THUS IT IS POSSIBLE THAT THE MAIN LOW
PRESSURE MAY NOT ARRIVE UNTIL CLOSER TO SAT NIGHT. THEN AN
ASSOCIATED COLD FRONT WILL WILL PUSH EAST ACROSS THE LAKE OVERNIGHT
SAT INTO SUN. WINDS AT THAT POINT WILL TURN WESTERLY THEN NORTHERLY
WITH MUCH COOLER AIR FLOWING OVER THE LAKE.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 7 PM SATURDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 7
PM SATURDAY.
LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565
UNTIL 7 AM FRIDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 9 PM THURSDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
1154 PM CDT TUE MAY 28 2013
.DISCUSSION...
ISSUED 907 PM CDT TUE MAY 28 2013
WHILE MOST OF CENTRAL AND SOUTHEAST ILLINOIS HAS BEEN DRY THIS
EVENING...AN AREA OF VERY HEAVY RAINFALL OCCURRED ACROSS PORTIONS
OF KNOX...STARK AND MARSHALL COUNTIES. SPOTTER REPORTS AROUND 3
INCHES WERE RECEIVED ACROSS PARTS OF KNOX COUNTY. THIS RAINFALL
PRODUCED FLASH FLOODING IN SOME AREAS. THESE STORMS FORMED ALONG
AN AXIS OF HIGH INSTABILITY ON THE WARM SIDE OF A FRONT THAT
EXTENDS FROM THE CENTRAL PLAINS INTO THE GREAT LAKES.
COVERAGE AND INTENSITY OF PRECIPITATION UPSTREAM HAS BEEN ON THE
DECREASE OVERALL WITH DIMINISHING DIURNAL INSTABILITY.
HOWEVER...STILL EXPECT AT LEAST SCATTERED SHOWERS/STORMS THROUGH
THE NIGHT ACROSS THE NORTHWEST HALF OF THE FORECAST AREA. THESE
STORMS WILL BE AIDED BY AN INCREASING LOW LEVEL JET ALONG THE
SURFACE FRONT. HOWEVER...SOME OF THE HIGH RESOLUTION MODELS
SUGGEST THE CONVECTION WILL BE A LITTLE FURTHER SOUTH INTO THE
FORECAST AREA THAN IT HAS BEEN...LIKELY FIRING IN THE VICINITY OF
OUTFLOW BOUNDARIES FROM THE EARLY EVENING CONVECTION.
GOING FORECAST IS IN GOOD SHAPE OVERALL. ONLY PLAN TO TWEAK FOR
THE EXPECTED OVERNIGHT TRENDS.
BAK
&&
.AVIATION...
ISSUED 1154 PM CDT TUE MAY 28 2013
PREDOMINANTLY VFR CONDITIONS EXPECTED ACROSS THE CENTRAL ILLINOIS
TERMINALS THROUGH THE 06Z TAF VALID TIME. HOWEVER...SCATTERED
SHOWERS AND THUNDERSTORMS MAY REDUCE CIGS/VSBYS TO MVFR FOR A FEW
HOURS OVERNIGHT. SOUTHERLY WINDS SHOULD PERSIST FOR MOST OF THE
PERIOD...OUTSIDE OF ANY LOCAL STORM IMPACTS... BECOMING GUSTY
DURING PEAK DIURNAL MIXING WEDNESDAY.
BAK
&&
.PREV DISCUSSION...
ISSUED 300 PM CDT TUE MAY 28 2013
COMPLICATED WEATHER PATTERN IN GENERAL MADE MORE COMPLICATED IN
THE MODELS WITH A STRUGGLE WITH THE PATTERN SHIFT OVERALL.
HOWEVER...FOR ALL THE NUANCES WITH THE WAVES MOVING THROUGH THE
FORECAST AREA...THE ONE AGREED UPON PORTION IN ALL THE OPERATIONAL
MODELS IS THAT CENTRAL ILLINOIS WILL BE RATHER WET THROUGH THE END
OF THE WEEK. WARM FRONT WELL TO THE NORTH OF THE CWA...LEAVING ILX
IN THE WARM SECTOR WITH WARM TEMPS AND DEWPOINTS IN A RATHER MUGGY
AIRMASS. THIS WARMTH AND MOISTURE WILL HELP TO FUEL ANY MCS REMNANTS/BOUNDARIES
THAT MOVE INTO THE FA...IN ADDITION TO THE OVERALL FRONT SCHEDULED
TO MOVE INTO THE MIDWEST AT MIDWEEK. WITH SWRLY FLOW ALOFT...THE
FRONT IS GOING TO LOSE ITS FORWARD MOMENTUM...SLOW MOVING...AND
SLOW TO EXIT. AS A RESULT...ANY WAVES THAT EJECT OUT OF THE SW AND
ALONG THE BOUNDARY WILL RESULT IN ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS. HEAVY RAIN IS LIKELY INVOF WHEREVER THE FRONT
LANDS...WHICH WILL NOT ONLY BE DIFFICULT TO PIN...FRONT WILL ALSO
END UP GETTING INFLUENCED GREATLY BY MESOSCALE INFLUENCES/COLD
POOLS/OUTFLOWS AS WELL. WITH GROUND ALREADY VERY SATURATED FROM
PREVIOUS RAINS...THE FLASH FLOODING THREAT MAY GET A BREAK
TOMORROW FOR PORTIONS OF CENTRAL ILLINOIS...BUT IT WILL BE BACK BY
THURSDAY.
SHORT TERM...TONIGHT THROUGH TOMORROW...
SCATTERED THUNDERSTORMS STILL POSSIBLE THROUGH THE EVENING WITH
CONVECTIVE INITIATION LIKELY TO THE WEST IN NRN MO JUST ACROSS THE
MISS RIVER VALLEY. BOTH RUC AND NMM/WRF KEEPING SOME
ACTIVITY...THOUGH THE RUC/RAP IS ACTUALLY CONFINING MUCH OF THE
ACTIVITY TO THE NORTH. THE 4KM WRF/NMM DEVELOPS MORE OF A LINEAR
COMPLEX THAT EVENTUALLY MOVES THROUGH THE FA TO THE SE AND WEAKENS
AS IT TRAVERSES THE CWA. SHOWER THREAT FINALLY DIMINISHES BRIEFLY
FOR WEDNESDAY...THOUGH THE THREAT OF ANY INTERACTION WITH THE WARM
FRONT TO THE NORTH RESULTS IN POPS ACROSS THE NRN TIER OF THE
STATE. WARM TEMPS...SOUTHERLY WINDS...AND ABUNDANT MOISTURE IN THE
BOUNDARY LAYER WILL PUSH HEAT INDEX VALUES INTO THE UPPER 80S/NEAR
90. WINDS WILL BE RATHER BREEZY AND HELP TO COUNTER SOME OF THE
EFFECTS...THOUGH CAUTION SHOULD BE USED BY ANYONE OUTDOORS
TOMORROW.
LONG TERM...THURSDAY THROUGH MONDAY...
THE WESTERN TROF DIGS IN...AMPLIFYING THE WAVE PATTERN OVER THE
CONUS AND LEAVING THE UPPER MIDWEST IN SWRLY FLOW...THROUGH
THURSDAY...WITH WARM TEMPS YET AGAIN ON THURSDAY. TEMPS IN THE NW
SHOULD BE SOMEWHAT DAMPENED HOWEVER...BY CLOUD COVER FROM
APPROACHING BOUNDARY. IN ADDITION...DIURNAL CURVE WILL LIKELY BE
SHATTERED BY THE CONVECTIVE ACTIVITY RUINING THE STEADY CLIMB OF
TEMPERATURES IN ANY ONE SPOT AHEAD OF THAT BOUNDARY. FORECAST
CONFIDENCE ABOUT DETAILS COMPLICATED WITH THE ELONGATED TROF IN
THE ECMWF/NAM IS PROVIDING A SLIGHTLY DIFFERENT SOLUTION WITH THE
SFC SYSTEM THAN THE NAM. THAT BEING SAID...THE ECMWF IS LOOKING A
BIT MORE LIKE THE GFS IN THE 12Z RUN. THOUGH EVERYONE IS IN
AGREEMENT ABOUT ENTERING A PROLONGED PERIOD OF PRECIP THROUGH DAY
5...THE DIFFERENCES IN THE MODELS WILL IMPACT THE DYNAMICS AND
ASSOCIATED SEVERE WEATHER THREAT. FORECASTING ONSET OF THE
HEAVIEST PRECIP ALONG THE APPROACHING FRONT. IN SUMMARY...THE RAIN
IS NOT OVER AS LONG AS THAT FRONT WITH THE NEXT SYSTEM GETS SLOWED
BY PARALLEL FLOW ALOFT.
HJS
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 7 AM CDT WEDNESDAY FOR ILZ027>031-
036>038-040>043-047>051.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1010 PM EDT THU MAY 30 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 248 PM EDT THU MAY 30 2013
SEVERAL UPPER LEVEL WAVES WILL EJECT OUT OF A LARGE TROUGH OVER THE
NORTHERN PLAINS AND ACROSS THE OHIO VALLEY INTO THE WEEKEND...
FOLLOWED BY THE PASSAGE OF LOW PRESSURE AND A COLD FRONT LATE
SATURDAY. THE COMBINATION OF THESE FEATURES WILL PROVIDE SEVERAL
OPPORTUNITIES FOR THUNDERSTORMS ACROSS CENTRAL INDIANA INTO EARLY
SUNDAY. HIGH PRESSURE WILL BUILD IN FOR THE FIRST HALF OF NEXT WEEK
WITH DRIER AND COOLER WEATHER ACROSS THE REGION.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 248 PM EDT THU MAY 30 2013
CU FIELD HAS BECOME WELL ESTABLISHED ACROSS THE FORECAST AREA THIS
AFTERNOON AS WARM...MOIST AND UNSTABLE AIR ADVECTS INTO THE REGION
AROUND THE LEE SIDE OF A LARGE UPPER TROUGH ACROSS THE PLAINS. ONE
OF THE MUGGIER AFTERNOONS IN PROGRESS SO FAR IN 2013 AS TEMPS HAD
RISEN INTO THE MID 80S ACROSS MUCH OF CENTRAL INDIANA AS OF 18Z.
COMPLEX FORECAST FOR TONIGHT AND CONTINUING OUT INTO THE WEEKEND AS
THE OHIO VALLEY RESIDES AHEAD OF A BROAD UPPER TROUGH OVER THE
PLAINS AND PLACES THE REGION IN A MOIST SOUTHWEST FLOW ALOFT.
SEVERAL VORTS ALOFT ALREADY CONTRIBUTING TO ROBUST CONVECTIVE
DEVELOPMENT OVER THE CENTRAL PLAINS AND OZARKS. ADDITIONAL
CONVECTIVE ACTIVITY HAS BROKEN OUT ACROSS THE MID MISSISSIPPI AND
LOWER OHIO VALLEYS WITHIN A REGION OF HIGHER CAPE VALUES AND
DEEPER BL SHEAR.
MESOANALYSIS INDICATING A MODERATELY UNSTABLE AIRMASS ACROSS CENTRAL
INDIANA THIS AFTERNOON WITH AIR TEMPS NEAR THE FORECAST CONVECTIVE
TEMPS. SO FAR...STORMS HAVE BEEN SLOW TO GET GOING OVER THE
FORECAST AREA. THE LACK OF BL SHEAR AND A SIGNIFICANT TRIGGER
ALOFT ARE LIKELY MITIGATING DEVELOPMENT AT THIS POINT BUT AS A
WEAK MID LEVEL VORT LIFTS INTO ILLINOIS BY LATE AFTERNOON...DO
EXPECT SCATTERED CONVECTION TO INCREASE IN COVERAGE WITH THE
GREATEST FOCUS OVER THE WESTERN HALF OF THE FORECAST AREA. LACK OF
SHEAR WILL KEEP STORMS DISORGANIZED AND OF A DIURNAL PULSE VARIETY
INTO THE EVENING HOURS. LOCALIZED SOAKERS ARE POSSIBLE WITH PRECIP
WATER VALUES NEAR 1.7 INCHES.
FOCUS FOR MORE WIDESPREAD CONVECTION COMES OVERNIGHT AS STORMS
ONGOING OVER WESTERN MISSOURI/EASTERN OKLAHOMA TRACK NORTHEAST WITH
AN ASSOCIATED WAVE ALOFT. MAY SEE COVERAGE DROP OFF FOR A FEW HOURS
DURING THE EVENING AND THEN RAMP BACK UP AS STORMS APPROACH FROM THE
WEST. ANTICIPATE THE LINE OF STORMS WILL BE DECREASING IN INTENSITY
AS IT ARRIVES DURING THE LATE EVENING AND INTO THE OVERNIGHT AS IT
MOVES AWAY FROM THE STRONGER BL SHEAR. HOWEVER...PRESENCE OF A
NOCTURNAL LOW LEVEL JET WILL CONTINUE TO PUMP A MOIST UNSTABLE
AIRMASS INTO THE REGION AND COMBINED WITH STRONGER FORCING
ALOFT...SHOULD ENABLE CONVECTION TO PERSIST OVERNIGHT. IMPACTS WILL
INCLUDE LOCALLY HEAVY RAIN WITH HIGH PRECIP WATER VALUES AND GUSTY
WINDS. WILL INCREASE TO LIKELY POPS OVER MUCH OF THE FORECAST AREA
AFTER MIDNIGHT.
TEMPS...EXPECT LOWS SIMILAR TO WEDNESDAY NIGHT WITH NEARLY IDENTICAL
LOW LEVEL THERMAL PROFILE. EXPECT TEMPS TO FALL ONLY INTO THE UPPER
60S TO AROUND 70. MOS GUIDANCE LOOKED GOOD.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
ISSUED AT 248 PM EDT THU MAY 30 2013
FORECAST CHALLENGES CONTINUE TO FOCUS ON PRECIP CHANCES...HEAVY RAIN
AND SEVERE STORM POTENTIAL THROUGH SATURDAY NIGHT UNTIL THE COLD
FRONT CAN MOVE THROUGH.
AS MENTIONED ABOVE...COMPLEX FORECAST THROUGH SATURDAY NIGHT AS
SEVERAL WAVES OF CONVECTION APPEAR POISED TO IMPACT THE REGION.
MODELS IN GENERAL ARE CLOSE WITH RESPECT TO THE MAIN BROAD SCALE
FEATURES. HOWEVER AS IS SO OFTEN THE CASE IN THESE PATTERNS...THE
MESOSCALE SETUP IS CRUCIAL IN DETERMINING THE SPECIFICS OF THE
FORECAST. OVERNIGHT CONVECTION SHOULD BE DEPARTING THE REGION FRIDAY
MORNING WITH JUST LEFTOVER SCATTERED CONVECTION AND CLOUDS. MODEL
GUIDANCE IS INDICATING A POCKET OF DRIER AIR FOLLOWING IN THE WAKE
OF THE OVERNIGHT CONVECTION WHICH SHOULD SERVE TO SCATTER OUT CLOUDS
AND ENABLE THE AIRMASS TO ONCE AGAIN BECOME UNSTABLE INTO FRIDAY
AFTERNOON.
WHILE SCATTERED CONVECTION WILL BE POSSIBLE AT ANY TIME ON
FRIDAY...SIGNS POINTING TO BEST CHANCE FOR SEVERE STORMS COMING LATE
FRIDAY AFTERNOON AND PERHAPS MORE LIKELY FRIDAY NIGHT AS ROBUST
CONVECTION DEVELOPS TO THE WEST AND NORTHWEST OF THE FORECAST AREA
AHEAD OF THE COLD FRONT. DYNAMICS AND FORCING ALOFT ARE MARKEDLY
BETTER FRIDAY AFTERNOON AND EVENING AS A SHARP UPPER JET CUTS
UNDERNEATH THE UPPER LOW AND INTO THE LOWER GREAT LAKES. THIS WILL
PROMOTE UPPER DIFFLUENCE AND INCREASE BL SHEAR VALUES ACROSS THE
LOWER GREAT LAKES. THE LOW LEVEL JET WILL ONCE AGAIN DEVELOP FRIDAY
EVENING AND COMBINED WITH FORCING ALOFT AND PLENTY OF INSTABILITY...
ANTICIPATE CONVECTION TO THE WEST TO FORM INTO EITHER A SQUALL LINE
OR AN MCS AND MIGRATE INTO THE FORECAST AREA FRIDAY NIGHT. WILL
GRADUALLY INCREASE TO LIKELY/CATEGORICAL POPS LATE FRIDAY NIGHT.
SEVERE THREAT IS MURKIER FOR SATURDAY AS LEFTOVER CONVECTION FROM
FRIDAY NIGHT ACTIVITY OR CLOUD DEBRIS MAY HAMPER EFFORTS FOR THE
ATMOSPHERE TO ONCE AGAIN DESTABILIZE. FORCING ALOFT REMAINS SOLID
SATURDAY AHEAD OF THE COLD FRONT WITH BL SHEAR VALUES OF 30-35KTS
PRESENT FOR MUCH OF THE DAY AND OHIO VALLEY REMAINING WITHIN THE
RIGHT REAR QUAD OF THE UPPER JET. A GREATER CONCERN ON SATURDAY MAY
END UP BEING ON HEAVY RAIN AND LOCALIZED FLOODING... ESPECIALLY WITH
DEEP LOW LEVEL CONVERGENCE PRESENT THROUGH 700MB AND PRECIP WATER
VALUES NEAR 1.75 INCHES. HOW MUCH RAIN FALLS FRIDAY AFTERNOON/NIGHT
WILL ALSO GREATLY INFLUENCE ANY FLOODING POTENTIAL GOING FORWARD
INTO THE WEEKEND. WILL CARRY CATEGORICAL POPS OVER THE ENTIRE
FORECAST AREA SATURDAY WITH A HEAVY RAIN MENTION.
THE FRONT WILL TRACK THROUGH CENTRAL INDIANA SATURDAY NIGHT AS LOW
PRESSURE MOVES THROUGH THE GREAT LAKES. WILL HOLD ONTO LOW CHANCE
POPS SUNDAY AS A TRAILING UPPER WAVE MAY SERVE TO GENERATE ISOLATED
CONVECTION. HIGH PRESSURE EXPANDING INTO THE REGION BY LATE SUNDAY
WILL END RAIN CHANCES.
TEMPS...GENERALLY LEANED CLOSER TO WARMER MAVMOS GUIDANCE FOR HIGHS
BOTH FRIDAY AND SATURDAY AS EVEN A LITTLE BIT OF SUN SHOULD ENABLE
TEMPS TO ROCKET INTO THE 80S. TEMPS WILL FALL BACK INTO THE
LOWER/MID 70S ON SUNDAY IN WAKE OF THE FRONTAL PASSAGE. MOS GUIDANCE
LOOKED REASONABLE FOR LOWS THROUGH THE PERIOD.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 215 PM EDT THU MAY 30 2013
ECMWF AND GFS ARE IN PRETTY GOOD AGREEMENT DURING THIS
PERIOD...EXCEPT ON WEDNESDAY INTO THURSDAY. INITIALLY A MUCH
COOLER...AND LESS HUMID AIR MASS WILL SETTLE ACROSS THE AREA FOR
MONDAY AND TUESDAY IN THE WAKE OF THE COLD FRONT. GOOD SUBSIDENCE
AND A NORTHWESTERLY FLOW OF COOL AIR WILL SETTLE ACROSS THE OHIO
VALLEY IN THE WAKE OF THE COLD FRONT.
BY WEDNESDAY AND THURSDAY THE GFS AND ECMWF BEGIN TO INTRODUCE A
WARM FRONT APPROACHING FROM THE NORTHWEST. THE ECMWF APPEARS A BIT
QUICKER WITH THIS FEATURE WHILE THE GFS IS SLOWER. GIVEN THE LARGE
HIGH AND COOL AIR MASS ALONG WITH THE STRONG RIDGE THAT WILL BE
OVER THE AREA DURING THE FIRST PARTS OF THE WEEK WILL OPT TOWARD
THE SLOWER SOLUTION AND ONLY KEEP PRECIP CHANCES IN FOR THURSDAY
FOR NOW WITH THE ADVANCE OF THE APPROACHING WARM FRONT.
&&
.AVIATION /DISCUSSION FOR 310300Z TAF ISSUANCE/...
ISSUED AT 1010 PM EDT THU MAY 30 2013
ONLY CHANGE WAS TO TWEAK CURRENT CONDITIONS. TIMING FOR LINE OF
THUNDERSTORMS ARRIVAL STILL LOOKS GOOD /AFTER 4Z FOR KHUF AND KLAF
AND AFTER 6Z FOR KBMG AND KIND/. PREVIOUS DISCUSSION FOLLOWS...
AN ACTIVE PERIOD IN STORE FOR THE TAF SITES. THE DIURNAL STORMS
THAT HAVE IMPACTED KHUF AND KLAF ARE WEAKENING AND SHOULD NO
LONGER BE AN IMPACT. HOWEVER A LARGE LINE OF THUNDERSTORMS OVER
ILLINOIS AND MISSOURI WILL BE ARRIVING LATER TONIGHT. TIME OF
ARRIVAL TOOL PUTS THE LINE NEAR KLAF AND KHUF AROUND 4-5Z AND KIND
AND KBMG AROUND 6Z OR SO. RAP SHOWS RAINS HANGING AROUND FOR
SEVERAL HOURS AND FORECAST GRIDS REFLECT THIS SO WILL CONTINUE
WITH PREVAILING THUNDER THROUGH 11Z OR SO AT KLAF AND KHUF TO AROUND
12-13Z FOR KBMG AND KIND. ANOTHER ROUND OF STORMS SHOULD GET GOING
FRIDAY AFTERNOON OR EVENING AND WITH LIKELY THUNDER AT KLAF AND
KHUF IN THE FORECAST INCLUDED PREVAILING THUNDER MENTION NEAR THE
END OF THE PERIOD AS WELL. WIND GUSTS OF 20-30 KTS WILL OCCUR
AGAIN FRIDAY THROUGHOUT THE DAY. THUNDERSTORMS SHOULD GENERALLY BE
MVFR TO IFR CONDITIONS WITH VFR IN BETWEEN STORMS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....PUMA
AVIATION...CP
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
736 PM EDT THU MAY 30 2013
.SYNOPSIS...
ISSUED AT 1038 AM EDT THU MAY 30 2013
A WEAK SYSTEM MOVING INTO THE REGION COULD SPAWN A FEW SHOWERS OR
ISOLATED STORMS FROM MIDDAY INTO THIS EVENING. TEMPERATURES WILL
RISE INTO THE MID TO UPPER 80S. WHILE THE CHANCES FOR SHOWERS AND
THUNDERSTORMS WILL INCREASE LATER THIS WEEKEND...THE CHANCE OF
SHOWERS AND A FEW NON SEVERE STORMS CAN NOT BE RULED OUT
OVERNIGHT. LOWS TONIGHT WILL BE IN THE UPPER 60S.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 300 PM EDT THU MAY 30 2013
THE MAIN FOCUS THIS PERIOD IS ON CONVECTIVE POTENTIAL/EVOLUTION.
SYNOPTICALLY...A CLOSED LOW WILL MEANDER SLOWLY EAST ACROSS THE
NORTHERN PLAINS WITH DEEP/MOIST CYCLONICALLY CURVED SOUTHWEST FLOW
IN PLACE FROM THE SOUTHERN PLAINS NORTHEAST INTO THE GREAT LAKES
REGION. AT THE SURFACE THE PRIMARY SFC FRONT FRONT WILL BE DRAPED
FROM THE UPPER MIDWEST SOUTHWEST INTO THE SOUTHERN PLAINS WITH A
MOIST/HUMID/UNSTABLE AIRMASS OUT AHEAD OF THIS.
THE REMAINDER OF THE AFTERNOON INTO EARLY THIS EVENING...
19Z REGIONAL RADAR MOSAIC SHOWING SCATTERED CONVECTION FIRING ACROSS
MUCH OF ILLINOIS IN A ZONE OF WEAK MOISTURE CONVERGENCE ON THE
EASTERN FLANK OF A CONVECTIVELY ENHANCED/INDUCED SHORTWAVE LIFTING
INTO WEST-CENTRAL ILLINOIS...WITH ISOLATED CONVECTION STARTING TO
POP ACROSS THE LOCAL AREA. LATEST RAP ANALYSIS SHOWS 1500-2000
J/KG OF MLCAPE ACROSS THE AREA WITH LITTLE/NO CIN. EXPECT ISOLATED
TO SCATTERED CONVECTION TO MAINLY IMPACT AREAS ALONG AND WEST OF
INTERSTATE 69 INTO THE EARLY EVENING AS WEAK FORCING AND CONTINUED
LOW/MID LEVEL THETA-E ADVECTION ADVECTS OVER THIS AREA. MARGINAL
20-25 KNOTS OF DEEP LAYER EFFECTIVE SHEAR A DEFINITE LIMITING
FACTOR FOR ORGANIZATION AND ISOLATED SEVERE STORMS...ALTHOUGH
CANNOT RULE OUT AN ISOLATED DAMAGING WIND/HAIL THREAT IF ANY
MULTICELL CLUSTERS/SMALL LINE SEGMENTS TAKE SHAPE.
LARGE SCALE UPPER SUPPORT WILL INCREASE TONIGHT INTO FRIDAY MORNING
AS A MORE PRONOUNCED MID LEVEL SHORTWAVE TROUGH NOW EJECTING INTO
THE CENTRAL PLAINS ON THE NOSE OF AN UPPER JET TRANSLATES NORTHEAST
INTO THE WESTERN/NORTHERN GREAT LAKES. THIS SUPPORTS THE IDEA OF
LATEST HI-RES GUIDANCE IN MAINTAINING A WEAKENING MESOSCALE
CONVECTIVE SYSTEM (ACROSS CENTRAL IOWA INTO WESTERN MISSOURI AS OF
THIS WRITING) EAST INTO AT LEAST OUR WESTERN ZONES AFTER 05/06Z ISH.
MEAGER MID LEVEL LAPSE RATES COUPLED WITH DIURNAL COOLING SHOULD
ALLOW WHAT MIGHT BE A LINE OF SEVERE CONVECTION INTO ILLINOIS THIS
EVENING TO WEAKEN (FALL APART?) AS IT ATTEMPTS TO MAKE INTO THE
LOCAL AREA FROM WEST TO EAST OVERNIGHT...WITH SHOWERS/ISO THUNDER
POSSIBLY LINGERING INTO FRIDAY MORNING ALONG THE MCS/MCV RESIDUAL
OUTFLOW BOUNDARY. BUMPED UP POPS A BIT AFTER MIDNIGHT....HIGHEST
WEST.
SUBSIDENCE/AVA BEHIND THE MID LEVEL TROUGH AXIS LATER FRIDAY MORNING
INTO THE EARLY/MID AFTERNOON HOURS WITH ATMOSPHERE POSSIBLY WORKED
OVER FROM MORNING CLOUDS/SHOWERS SHOULD RESULT IN A LULL IN PCPN
ACROSS THE AREA DURING THIS TIME. ALTHOUGH RETAINED LOW 20-30
PERCENT POPS BTW 15-21Z AS RENEWED CONVECTION COULD FORM ALONG THE
RESIDUAL OUTFLOW BOUNDARY BY EARLY/MID AFTERNOON...BEST CHANCES
ACROSS OUR SOUTHEASTERN ZONES. CHANCES FOR ADDITIONAL
CONVECTION...POTENTIALLY SEVERE...BY LATE AFTERNOON AND EVENING
ARE DISCUSSED IN THE LONG TERM SECTION.
&&
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 300 PM EDT THU MAY 30 2013
POTENT SW AND ATTENDANT CLOSED LOW OVR SD IS XCPD TO OPEN FRI NIGHT
AND KICK EWD ACRS THE LAKES IN RESPONSE OF ARRIVAL OF UPSTREAM
KICKER INTO THE PACNW. AT THE SFC...PRONOUNCED SFC WAVE OVR SRN MN
SAT MORNING WILL EJECT EWD TO LK HURON BY SUN MORNING AS ASSOCD
TRAILING CDFNT SURGES EWD.
BEST LL MSTR FLUX/LL THETA-E RIDGING XCPD FRI EVENING W/AGAIN A
CONDITIONAL SVR THREAT PENDING SHRT TERM CONV EVOLUTION/MAINTENANCE
INTO THE WRN LAKES FRI AFTN. OTRWS STG SFC CDFNT TO CROSS CWA SAT
AFTN/EVE W/STG FORCING FOR ASCENT WITHIN CONTD SIG LL MSTR PLUME AND
LIKELY MOST FVRBL WINDOW FOR SIG RAINFALL.
STG CAA FOLLOWS ON SUN W/RAPID NEWD ADVTN OF MID LVL DRYSLOT
UNDERNEATH MID LVL TROUGH PIVOTING THROUGH MI. GIVEN GENERAL 12Z
CONSENSUS SOLUTION WILL DROP LOW CHC POPS MOST AREAS SANS FAR SE.
DRY AND SEASONABLE WX XPCD THROUGH UNTIL THE END OF THE PD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 729 PM EDT THU MAY 30 2013
SCATTERED CONVECTION IN A GENERAL WEAKENING TREND THIS EVENING PER
RADAR TRENDS...HOWEVER COULD IMPACT TERMINALS...ESPECIALLY
KFWA...THROUGH 02Z. EXPECTED DRY PERIOD AFTER 02Z...HOWEVER FOCUS
SHIFTS TO WELL DEVELOPED MCS CURRENTLY ACROSS FAR WESTERN IL.
TIMED OUT ARRIVAL PER RADAR TRENDS AT KSBN AROUND 04Z...MUCH
FASTER THAN MODEL GUIDANCE...AND SHOULD BE IN A DECAYING STATE.
LEFT KFWA DRY GIVEN UNCERTAINTY THAT CONVECTION WILL STILL BE
ONGOING THAT FAR EASTWARD...HOWEVER WILL CONTINUE TO WATCH LATEST
HI RES GUIDANCE/RADAR TRENDS AND UPDATE IF NEEDED. SOUTHERLY GUSTY
WINDS OUTSIDE OF THUNDERSTORMS SHOULD SUBSIDE OVERNIGHT...BUT PICK
UP AGAIN AFTER 12Z FRIDAY.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR LMZ043-046.
&&
$$
SYNOPSIS...BENTLEY
SHORT TERM...STEINWEDEL
LONG TERM...T
AVIATION...NG
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
720 PM EDT THU MAY 30 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 248 PM EDT THU MAY 30 2013
SEVERAL UPPER LEVEL WAVES WILL EJECT OUT OF A LARGE TROUGH OVER THE
NORTHERN PLAINS AND ACROSS THE OHIO VALLEY INTO THE WEEKEND...
FOLLOWED BY THE PASSAGE OF LOW PRESSURE AND A COLD FRONT LATE
SATURDAY. THE COMBINATION OF THESE FEATURES WILL PROVIDE SEVERAL
OPPORTUNITIES FOR THUNDERSTORMS ACROSS CENTRAL INDIANA INTO EARLY
SUNDAY. HIGH PRESSURE WILL BUILD IN FOR THE FIRST HALF OF NEXT WEEK
WITH DRIER AND COOLER WEATHER ACROSS THE REGION.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 248 PM EDT THU MAY 30 2013
CU FIELD HAS BECOME WELL ESTABLISHED ACROSS THE FORECAST AREA THIS
AFTERNOON AS WARM...MOIST AND UNSTABLE AIR ADVECTS INTO THE REGION
AROUND THE LEE SIDE OF A LARGE UPPER TROUGH ACROSS THE PLAINS. ONE
OF THE MUGGIER AFTERNOONS IN PROGRESS SO FAR IN 2013 AS TEMPS HAD
RISEN INTO THE MID 80S ACROSS MUCH OF CENTRAL INDIANA AS OF 18Z.
COMPLEX FORECAST FOR TONIGHT AND CONTINUING OUT INTO THE WEEKEND AS
THE OHIO VALLEY RESIDES AHEAD OF A BROAD UPPER TROUGH OVER THE
PLAINS AND PLACES THE REGION IN A MOIST SOUTHWEST FLOW ALOFT.
SEVERAL VORTS ALOFT ALREADY CONTRIBUTING TO ROBUST CONVECTIVE
DEVELOPMENT OVER THE CENTRAL PLAINS AND OZARKS. ADDITIONAL
CONVECTIVE ACTIVITY HAS BROKEN OUT ACROSS THE MID MISSISSIPPI AND
LOWER OHIO VALLEYS WITHIN A REGION OF HIGHER CAPE VALUES AND
DEEPER BL SHEAR.
MESOANALYSIS INDICATING A MODERATELY UNSTABLE AIRMASS ACROSS CENTRAL
INDIANA THIS AFTERNOON WITH AIR TEMPS NEAR THE FORECAST CONVECTIVE
TEMPS. SO FAR...STORMS HAVE BEEN SLOW TO GET GOING OVER THE
FORECAST AREA. THE LACK OF BL SHEAR AND A SIGNIFICANT TRIGGER
ALOFT ARE LIKELY MITIGATING DEVELOPMENT AT THIS POINT BUT AS A
WEAK MID LEVEL VORT LIFTS INTO ILLINOIS BY LATE AFTERNOON...DO
EXPECT SCATTERED CONVECTION TO INCREASE IN COVERAGE WITH THE
GREATEST FOCUS OVER THE WESTERN HALF OF THE FORECAST AREA. LACK OF
SHEAR WILL KEEP STORMS DISORGANIZED AND OF A DIURNAL PULSE VARIETY
INTO THE EVENING HOURS. LOCALIZED SOAKERS ARE POSSIBLE WITH PRECIP
WATER VALUES NEAR 1.7 INCHES.
FOCUS FOR MORE WIDESPREAD CONVECTION COMES OVERNIGHT AS STORMS
ONGOING OVER WESTERN MISSOURI/EASTERN OKLAHOMA TRACK NORTHEAST WITH
AN ASSOCIATED WAVE ALOFT. MAY SEE COVERAGE DROP OFF FOR A FEW HOURS
DURING THE EVENING AND THEN RAMP BACK UP AS STORMS APPROACH FROM THE
WEST. ANTICIPATE THE LINE OF STORMS WILL BE DECREASING IN INTENSITY
AS IT ARRIVES DURING THE LATE EVENING AND INTO THE OVERNIGHT AS IT
MOVES AWAY FROM THE STRONGER BL SHEAR. HOWEVER...PRESENCE OF A
NOCTURNAL LOW LEVEL JET WILL CONTINUE TO PUMP A MOIST UNSTABLE
AIRMASS INTO THE REGION AND COMBINED WITH STRONGER FORCING
ALOFT...SHOULD ENABLE CONVECTION TO PERSIST OVERNIGHT. IMPACTS WILL
INCLUDE LOCALLY HEAVY RAIN WITH HIGH PRECIP WATER VALUES AND GUSTY
WINDS. WILL INCREASE TO LIKELY POPS OVER MUCH OF THE FORECAST AREA
AFTER MIDNIGHT.
TEMPS...EXPECT LOWS SIMILAR TO WEDNESDAY NIGHT WITH NEARLY IDENTICAL
LOW LEVEL THERMAL PROFILE. EXPECT TEMPS TO FALL ONLY INTO THE UPPER
60S TO AROUND 70. MOS GUIDANCE LOOKED GOOD.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
ISSUED AT 248 PM EDT THU MAY 30 2013
FORECAST CHALLENGES CONTINUE TO FOCUS ON PRECIP CHANCES...HEAVY RAIN
AND SEVERE STORM POTENTIAL THROUGH SATURDAY NIGHT UNTIL THE COLD
FRONT CAN MOVE THROUGH.
AS MENTIONED ABOVE...COMPLEX FORECAST THROUGH SATURDAY NIGHT AS
SEVERAL WAVES OF CONVECTION APPEAR POISED TO IMPACT THE REGION.
MODELS IN GENERAL ARE CLOSE WITH RESPECT TO THE MAIN BROAD SCALE
FEATURES. HOWEVER AS IS SO OFTEN THE CASE IN THESE PATTERNS...THE
MESOSCALE SETUP IS CRUCIAL IN DETERMINING THE SPECIFICS OF THE
FORECAST. OVERNIGHT CONVECTION SHOULD BE DEPARTING THE REGION FRIDAY
MORNING WITH JUST LEFTOVER SCATTERED CONVECTION AND CLOUDS. MODEL
GUIDANCE IS INDICATING A POCKET OF DRIER AIR FOLLOWING IN THE WAKE
OF THE OVERNIGHT CONVECTION WHICH SHOULD SERVE TO SCATTER OUT CLOUDS
AND ENABLE THE AIRMASS TO ONCE AGAIN BECOME UNSTABLE INTO FRIDAY
AFTERNOON.
WHILE SCATTERED CONVECTION WILL BE POSSIBLE AT ANY TIME ON
FRIDAY...SIGNS POINTING TO BEST CHANCE FOR SEVERE STORMS COMING LATE
FRIDAY AFTERNOON AND PERHAPS MORE LIKELY FRIDAY NIGHT AS ROBUST
CONVECTION DEVELOPS TO THE WEST AND NORTHWEST OF THE FORECAST AREA
AHEAD OF THE COLD FRONT. DYNAMICS AND FORCING ALOFT ARE MARKEDLY
BETTER FRIDAY AFTERNOON AND EVENING AS A SHARP UPPER JET CUTS
UNDERNEATH THE UPPER LOW AND INTO THE LOWER GREAT LAKES. THIS WILL
PROMOTE UPPER DIFFLUENCE AND INCREASE BL SHEAR VALUES ACROSS THE
LOWER GREAT LAKES. THE LOW LEVEL JET WILL ONCE AGAIN DEVELOP FRIDAY
EVENING AND COMBINED WITH FORCING ALOFT AND PLENTY OF INSTABILITY...
ANTICIPATE CONVECTION TO THE WEST TO FORM INTO EITHER A SQUALL LINE
OR AN MCS AND MIGRATE INTO THE FORECAST AREA FRIDAY NIGHT. WILL
GRADUALLY INCREASE TO LIKELY/CATEGORICAL POPS LATE FRIDAY NIGHT.
SEVERE THREAT IS MURKIER FOR SATURDAY AS LEFTOVER CONVECTION FROM
FRIDAY NIGHT ACTIVITY OR CLOUD DEBRIS MAY HAMPER EFFORTS FOR THE
ATMOSPHERE TO ONCE AGAIN DESTABILIZE. FORCING ALOFT REMAINS SOLID
SATURDAY AHEAD OF THE COLD FRONT WITH BL SHEAR VALUES OF 30-35KTS
PRESENT FOR MUCH OF THE DAY AND OHIO VALLEY REMAINING WITHIN THE
RIGHT REAR QUAD OF THE UPPER JET. A GREATER CONCERN ON SATURDAY MAY
END UP BEING ON HEAVY RAIN AND LOCALIZED FLOODING... ESPECIALLY WITH
DEEP LOW LEVEL CONVERGENCE PRESENT THROUGH 700MB AND PRECIP WATER
VALUES NEAR 1.75 INCHES. HOW MUCH RAIN FALLS FRIDAY AFTERNOON/NIGHT
WILL ALSO GREATLY INFLUENCE ANY FLOODING POTENTIAL GOING FORWARD
INTO THE WEEKEND. WILL CARRY CATEGORICAL POPS OVER THE ENTIRE
FORECAST AREA SATURDAY WITH A HEAVY RAIN MENTION.
THE FRONT WILL TRACK THROUGH CENTRAL INDIANA SATURDAY NIGHT AS LOW
PRESSURE MOVES THROUGH THE GREAT LAKES. WILL HOLD ONTO LOW CHANCE
POPS SUNDAY AS A TRAILING UPPER WAVE MAY SERVE TO GENERATE ISOLATED
CONVECTION. HIGH PRESSURE EXPANDING INTO THE REGION BY LATE SUNDAY
WILL END RAIN CHANCES.
TEMPS...GENERALLY LEANED CLOSER TO WARMER MAVMOS GUIDANCE FOR HIGHS
BOTH FRIDAY AND SATURDAY AS EVEN A LITTLE BIT OF SUN SHOULD ENABLE
TEMPS TO ROCKET INTO THE 80S. TEMPS WILL FALL BACK INTO THE
LOWER/MID 70S ON SUNDAY IN WAKE OF THE FRONTAL PASSAGE. MOS GUIDANCE
LOOKED REASONABLE FOR LOWS THROUGH THE PERIOD.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 215 PM EDT THU MAY 30 2013
ECMWF AND GFS ARE IN PRETTY GOOD AGREEMENT DURING THIS
PERIOD...EXCEPT ON WEDNESDAY INTO THURSDAY. INITIALLY A MUCH
COOLER...AND LESS HUMID AIR MASS WILL SETTLE ACROSS THE AREA FOR
MONDAY AND TUESDAY IN THE WAKE OF THE COLD FRONT. GOOD SUBSIDENCE
AND A NORTHWESTERLY FLOW OF COOL AIR WILL SETTLE ACROSS THE OHIO
VALLEY IN THE WAKE OF THE COLD FRONT.
BY WEDNESDAY AND THURSDAY THE GFS AND ECMWF BEGIN TO INTRODUCE A
WARM FRONT APPROACHING FROM THE NORTHWEST. THE ECMWF APPEARS A BIT
QUICKER WITH THIS FEATURE WHILE THE GFS IS SLOWER. GIVEN THE LARGE
HIGH AND COOL AIR MASS ALONG WITH THE STRONG RIDGE THAT WILL BE
OVER THE AREA DURING THE FIRST PARTS OF THE WEEK WILL OPT TOWARD
THE SLOWER SOLUTION AND ONLY KEEP PRECIP CHANCES IN FOR THURSDAY
FOR NOW WITH THE ADVANCE OF THE APPROACHING WARM FRONT.
&&
.AVIATION /DISCUSSION FOR 310000Z TAF ISSUANCE/...
ISSUED AT 705 PM EDT THU MAY 30 2013
AN ACTIVE PERIOD IN STORE FOR THE TAF SITES. THE DIURNAL STORMS
THAT HAVE IMPACTED KHUF AND KLAF ARE WEAKENING AND SHOULD NO
LONGER BE AN IMPACT. HOWEVER A LARGE LINE OF THUNDERSTORMS OVER
ILLINOIS AND MISSOURI WILL BE ARRIVING LATER TONIGHT. TIME OF
ARRIVAL TOOL PUTS THE LINE NEAR KLAF AND KHUF AROUND 4-5Z AND KIND
AND KBMG AROUND 6Z OR SO. RAP SHOWS RAINS HANGING AROUND FOR
SEVERAL HOURS AND FORECAST GRIDS REFLECT THIS SO WILL CONTINUE
WITH PREVAILING THUNDER THROUGH 11Z OR SO AT KLAF AND KHUF TO AROUND
12-13Z FOR KBMG AND KIND. ANOTHER ROUND OF STORMS SHOULD GET GOING
FRIDAY AFTERNOON OR EVENING AND WITH LIKELY THUNDER AT KLAF AND
KHUF IN THE FORECAST INCLUDED PREVAILING THUNDER MENTION NEAR THE
END OF THE PERIOD AS WELL. WIND GUSTS OF 20-30 KTS WILL OCCUR
AGAIN FRIDAY THROUGHOUT THE DAY. THUNDERSTORMS SHOULD GENERALLY BE
MVFR TO IFR CONDITIONS WITH VFR IN BETWEEN STORMS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....PUMA
AVIATION...CP
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AREA FORECAST DISCUSSION
NWS DES MOINES IA
631 PM CDT THU MAY 30 2013
...UPDATED AVIATION DISCUSSION...
.SHORT TERM.../TONIGHT /...
ISSUED AT 350 PM CDT THU MAY 30 2013
MAIN SHORTWAVE LIFTING THROUGH THE BASE OF THE UPPER LEVEL TROUGH
RESPONSIBLE FOR AREA OF SHOWERS AND THUNDERSTORMS ACROSS THE FAR
SOUTHEASTERN CWA. AS SHORTWAVE CONTINUES TO LIFT NORTHEAST THROUGH
THE EASTERN PORTION OF THE STATE...AREA OF SHOWERS/THUNDERSTORMS
WILL CONTINUE TO SHOVE EAST OUT OF THE CWA. LOOKING BACK TO THE
WEST...HAVE SOME ISOLATED WEAK CELLS DEVELOPING ACROSS CENTRAL
NE/KS. THIS ACTIVITY MAY APPROACH THE SOUTHWESTERN/SOUTHERN CWA BY
MID EVENING...BUT IS EXPECTED TO BE RELATIVELY WEAK WITH LESS THAN
1000 J/KG CAPE ON NAM/RAP SOUNDINGS. HRRR SEEMS TO BE GRASPING
CURRENT RADAR TRENDS CORRECTLY...SO KEPT POPS CLOSE TO THE HRRR
OUTPUT. THE WESTERN ACTIVITY IS MOSTLY DIURNALLY DRIVEN...SO EXPECT
IT TO DIMINISH TOWARD SUNSET. ANOTHER WAVE OF ENERGY TO ROUND THE
BASE OF THE UPPER LEVEL TROUGH TO APPROACH THE STATE LATE
TONIGHT...MAY ALLOW FOR SOME SHOWERS AND ISOLATED THUNDERSTORMS TO
DEVELOP TOWARD SUNRISE FRIDAY MORNING. THE DEEP MOISTURE THAT HAS
BEEN IN PLACE ACROSS THE STATE OVER THE PAST WEEK...IS BEGINNING TO
PUSH EAST WITH THE ADVANCEMENT OF A DRY LINE OVER CENTRAL
NE/KS...THEREFORE THE HEAVY RAIN THREAT WILL BE LESSENED WITH ANY
ACTIVITY THAT DEVELOPS LATE TONIGHT/EARLY FRIDAY MORNING.
.LONG TERM.../FRIDAY THROUGH THURSDAY/...
ISSUED AT 350 PM CDT THU MAY 30 2013
AN UPPER LEVEL LOW PRESSURE SYSTEM WILL REMAIN NEARLY STATIONARY
OVER THE DAKOTAS AND MINNESOTA FRIDAY AND FRIDAY NIGHT...BEFORE
MOVING EASTWARD ACROSS IOWA ON SATURDAY AND AWAY OVER THE GREAT
LAKES ON SATURDAY NIGHT. ON FRIDAY MORNING LOW LEVEL FLOW WILL
STILL BE FROM THE SOUTH SOUTHWEST AND AN APPROACHING SHORTWAVE
MOVING AROUND THE UPPER LOW SHOULD KICK OFF THUNDERSTORMS ACROSS
EASTERN KANSAS LATE TONIGHT THAT WILL MOVE ACROSS OUR SOUTHERN AND
EASTERN COUNTIES ON FRIDAY. HAVE INCREASED POPS INTO THE 70 TO 80
PERCENT RANGE IN OUR SOUTHEAST TO ACCOUNT FOR THIS...AND SEVERE
WEATHER WILL BE POSSIBLE IN THESE AREAS AS WELL. FRIDAY SHOULD BE
FAIRLY WARM ESPECIALLY IF SKIES ARE ABLE TO CLEAR ACROSS MUCH OF
THE CWA...AND HAVE RAISED FORECAST HIGHS A BIT EVEN INTO THE
LOWER 80S IN SOME AREAS.
BY FRIDAY EVENING THE DAYTIME STORMS WILL BE EXITING TO THE EAST
AHEAD OF A SURFACE TROUGH MOVING ACROSS THE AREA. WINDS BEHIND
THIS TROUGH WILL TURN TO WEST AND THEN NORTHWEST WITH COOLER AIR
FLOWING INTO THE AREA. IN ADDITION...AS THE UPPER LEVEL LOW
PRESSURE TROUGH MOVES ACROSS OUR AREA ON SATURDAY IT WILL BE
ACCOMPANIED BY THICK CLOUDS AND LIGHT SHOWERS MAKING FOR A GREY
AND DAMP DAY. NO THUNDERSTORMS ARE ANTICIPATED AND ANY RAINFALL
AMOUNTS WILL BE LIGHT. COVERAGE IS UNCERTAIN SO HAVE MAINTAINED
POPS BELOW 50 PERCENT...BUT THIS MAY NEED TO BE INCREASED LATER IN
A CLASSIC HIGH POP/LOW QPF SCENARIO. BY SUNDAY A SURFACE RIDGE
WILL BUILD IN MAKING FOR MOSTLY CLEAR AND DRY BUT COOL WEATHER
WITH LIGHT NORTH WINDS.
FROM SUNDAY NIGHT THROUGH THURSDAY THE 500 MB PATTERN WILL UNDERGO
AN EERILY SIMILAR EVOLUTION TO WHAT WE HAVE SEEN OVER THE LAST
SEVERAL DAYS...AS ANOTHER UPPER LOW MOVES INTO THE NORTHWESTERN
U.S. AND THEN ACROSS THE UPPER MIDWEST. THIS WILL RESULT IN
ANOTHER EXTENDED PERIOD OF THUNDERSTORM CHANCES FOR OUR AREA FROM
MONDAY NIGHT THROUGH THE END OF THE FORECAST PERIOD.
HOWEVER...UNLIKE THE SYSTEM OF THE PAST SEVERAL DAYS...THE 500 MB
LOW NEXT WEEK WILL NOT HAVE AS MUCH LATITUDINAL EXTENT AND WILL BE
GENERALLY MORE PROGRESSIVE...MITIGATING SOMEWHAT THE POTENTIAL FOR
EXTENDED HEAVY RAINFALL. THE DETAILS OF THE RAINFALL FORECAST FOR
NEXT WEEK WILL BE IRONED OUT LATER...BUT AT LEAST THERE WILL BE
SEVERAL RELATIVELY DRY DAYS THIS WEEKEND TO ALLOW CURRENT FLOOD
WATERS TO SUBSIDE...AND RAINFALL AMOUNTS NEXT WEEK SHOULD BE
CONSIDERABLY LIGHTER IN MOST AREAS WITH THE PRIMARY CHANCES
LIMITED TO THE MONDAY NIGHT...TUESDAY...AND TUESDAY NIGHT PERIODS.
&&
.AVIATION...31/00Z
ISSUED AT 628 PM CDT THU MAY 30 2013
SPORADIC MVFR CIGS THROUGH THE EVENING MAY IMPACT DSM/FOD/MCW/ALO
AND ONLY TAF SITE CONFIDENT ENOUGH TO MENTION MVFR CIGS WAS AT MCW
AS CURRENTLY REPORTING. WITH THE OTHER SITES...KEPT VFR ATTM BUT
CANNOT RULE OUT A SHORT TIME FRAME OF MVFR CIGS...GENERALLY AROUND
2500-3000 FEET THROUGH 06Z TONIGHT. WINDS LOOK TO REMAIN SOUTHERLY
BEFORE SHIFTING MORE SOUTHWEST TOMORROW. DECENT MIXING AND
INCREASED WIND GUSTS LATE IN THE PERIOD.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR BUTLER.
&&
$$
SHORT TERM...BEERENDS
LONG TERM...LEE
AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1237 PM CDT WED MAY 29 2013
.UPDATE...
ISSUED AT 1230 PM CDT WED MAY 29 2013
CONVECTIVE TEMPERATURE IS BEING ACHIEVED WITH SATELLITE SHOWING CU
DEVELOPING. THE SFC WIND PLOT INDICATES THE 850MB WARM FRONT IS
SLOWLY MOVING NORTH THROUGH THE CWFA. AS MENTIONED EARLIER... THIS
FEATURE MAY PROVIDE A FOCUS FOR INDIVIDUAL CONVECTION TO BECOME
MORE ORGANIZED DURING THE AFTERNOON.
BASED ON THE LATEST RAP TRENDS FROM THE MCS AND LIFT TOOLS...
CONVECTION IS EXPECTED TO BEGIN DEVELOPING ACROSS THE AREA BY MID
AFTERNOON. ..08..
UPDATE ISSUED AT 939 AM CDT WED MAY 29 2013
12Z UA ANALYSIS IS INTERESTING. THERE IS A STRONG PLUME OF DEEP
MOISTURE RUNNING FROM NORTHERN MEXICO INTO NORTHWEST MISSOURI.
KTOP MAY BE PARTIALLY CONTAMINATED BY CONVECTION BUT DEW POINTS IN
THE MID TEENS ARE PRESENT IN THIS PLUME. THE 850MB WARM FRONT RUNS
FROM A LOW IN NORTHWEST KANSAS...TO JUST NORTH OF KOMA...TO NEAR KILX.
THE CURRENT CONVECTION THAT HAS DEVELOPED IN THE TRI-STATE AREA OF
NE/KS/MO WILL MAINTAIN ITSELF THROUGH THE MORNING AS IT IS LOCATED
IN THE BETTER MOISTURE AND STRONGER LLJ.
MCS AND LIFT TOOLS INDICATE THIS CONVECTION SHOULD CONTINUE MOVING
NORTHEASTWARD THROUGH THE LATE MORNING AND AFTERNOON. A THETA E
GRADIENT DOES DEVELOP BY LATE MORNING/EARLY AFTERNOON OVER THE
CWFA MOST LIKELY IN RESPONSE TO THE 850MB WARM FRONT.
CONVECTION OVER THE CWFA WILL BE SEEN BUT WE WILL LIKELY HOLD OFF
UNTIL CONVECTIVE TEMPERATURE IS ACHIEVED. CONVECTIVE TEMPERATURE
SHOULD BE ACHIEVED AROUND MID DAY PLUS/MINUS AN HOUR. WEAK VORT
MAXES MOVING ALONG IN THE FLOW ALOFT IS EXPECTED TO ALLOW
CONVECTION TO BECOME MORE NUMEROUS AS THE AFTERNOON PROGRESSES.
THE 850MB WARM FRONT MAY ALLOW INDIVIDUAL CELLS TO BECOME MORE
ORGANIZED DURING THE AFTERNOON HOURS. ..08..
UPDATE ISSUED AT 650 AM CDT WED MAY 29 2013
THE FLASH FLOOD WATCH WAS DROPPED AROUND 6 AM WITH THE LAST OF THE
OVERNIGHT MCS MOVING EAST OF THE AREA. NO CHANGES WERE MADE TO THE
REST OF THE FORECAST HOWEVER THE ELEVATED TSRA JUST SHOWING UP IN
NORTHEAST KANSAS AND NW MO WILL HAVE TO BE WATCH. CURRENT
TRAJECTORY SHOULD KEEP IT WEST OF THE FORECAST AREA THIS MORNING.
IF IT SPREADS FURTHER EAST THAN EXPECTED THAN POPS WILL HAVE TO BE
ADJUSTED UP FOR IN THE WEST FOR THIS MORNING.
DLF
&&
.SYNOPSIS...
ISSUED AT 357 AM CDT WED MAY 29 2013
A STATIONARY FRONT WAS LOCATED JUST NORTH OF THE FORECAST AREA
EARLY THIS MORNING. THE FRONT EXTENDED SOUTHWEST INTO LOW PRESSURE
OVER EASTERN COLORADO. THE UPPER TROF WAS STILL OVER ROCKIES THIS
MORNING WITH A BROAD AREA OF SOUTHWESTERLY FLOW DOWNSTREAM INTO
THE CENTRAL U.S. THE LATEST MCS TO MOVE THROUGH THE REGION WAS
OVER THE SOUTHERN CWFA AND IS ON TRACK TO EXIT THE FORECAST AREA
AROUND 12Z.
&&
.SHORT TERM...(TODAY)
ISSUED AT 357 AM CDT WED MAY 29 2013
CATEGORICAL POPS WERE CONTINUED OVER THE SOUTH PRIOR TO 12Z...TO
COVER THE EXITING MCS. AFTER THAT HAVE PULLED POPS BACK TO CHANCE
CATEGORY FOR THE REST OF THE DAY. WITH THE STATIONARY FRONT NORTH
OF THE FORECAST AREA THERE WILL BE A LACK OF A SIGNIFICANT FEATURE
FOR CONVECTION TO FOCUS ON THE REST OF THE DAY. MODELS ARE SHOWING
A WEAK S/W LIFTING THROUGH THIS AFTERNOON...DURING PEAK HEATING.
PW/S WILL STILL EXCEED 1.5 INCHES OVER THE AREA TODAY SO ANY
STORMS THAT DEVELOP COULD PRODUCE BRIEF HEAVY RAINS. SINCE THERE
WILL NOT BE ANY SURFACE BOUNDARIES OVER AREA TO HELP ORGANIZE STORMS
THAT DEVELOP...THE THREAT OF WIDESPREAD HEAVY RAINS WILL BE LOW.
THEREFORE THE FLASH FLOOD WATCH WILL NOT BE EXTENDED PAST 12Z
PROVIDED THE CURRENT MCS IS OUT OF THE AREA BY THAT TIME. AFTER
THE MCS MOVES EAST OF THE AREA WE SHOULD SEE SOME FILTERED SUN BY
LATE MORNING OR EARLY AFTERNOON WHICH WILL HELP PUSH TEMPERATURES
INTO THE LOW TO MID 80S OVER MOST OF THE AREA.
.LONG TERM...(TONIGHT THROUGH TUESDAY)
ISSUED AT 357 AM CDT WED MAY 29 2013
ACTIVE PATTERN WILL KEEP A CONTINUED THREAT OF THUNDERSTORMS...HEAVY
RAIN AND FLOODING THROUGH FRIDAY. UPPER WAVE PROGGED TO SWEEP PAST
TO THE NORTH ON SATURDAY WILL SHUNT THE PERSISTENT STREAM OF GULF
MOISTURE EASTWARD TOWARD THE NORTHEAST U.S...ENDING THE HEAVY RAIN
THREAT. HIGH PRESSURE THAT FOLLOWS FOR SUNDAY INTO AT LEAST MONDAY
WILL PROVIDE A MUCH NEEDED BREAK OF DRY AND SOMEWHAT COOLER WEATHER.
TONIGHT...FORECAST MODELS INDICATE CONDITIONS OVERALL WILL BE LESS
SUPPORTIVE OF ORGANIZED MCS ACTIVITY AFFECTING THE FORECAST AREA.
THE 850 MB CONVERGENCE AXIS AND SURFACE BOUNDARY OVER THE FORECAST
AREA TONIGHT WILL BE PUSHED WELL TO THE NORTH...BUT THERE WILL STILL
BE ADDITIONAL RIPPLES IN THE S-SW UPPER LEVEL FLOW AND POSSIBLE WEAK
LOW LEVEL BOUNDARIES TO WARRANT AT LEAST LOW END CHANCE POPS FOR
THUNDERSTORMS.
THURSDAY AND FRIDAY...THE HEAVY RAINFALL THREAT RETURNS AS MODELS CONTINUE
TO DEPICT A STRONG UPPER LEVEL WAVE...CURRENTLY MOVING THROUGH THE 4
CORNERS REGION...TO LIFT THROUGH DURING PEAK HEATING THURSDAY. THIS
WOULD LIKELY BE FOLLOWED BY ADDITIONAL WAVES AND MCS/S OVERNIGHT
OVER THE REGION AND POSSIBLY INTO THE LOCAL AREA...MUCH LIKE WHAT
HAS OCCURRED THE PAST SEVERAL NIGHTS. THIS WILL ALSO PRESENT A
CONTINUED RISK FOR SEVERE STORMS AND SPC HAS A SLIGHT RISK OVER THE
ENTIRE FORECAST AREA. WITH A SIMILAR MOISTURE FEED AS THE PAST
SEVERAL DAYS...WILL CARRY A WIDESPREAD...BROAD-BRUSHED 1 TO ROUGHLY
1.4 INCHES OF QPF FOR THE DAYTIME THURSDAY. MUCH HIGHER AMOUNTS WILL
BE POSSIBLE AND WILL LIKELY NEED A FLASH FLOOD WATCH BEGINNING
THURSDAY...POSSIBLY CONTINUING THROUGH FRIDAY...WHEN ADDITIONAL
WAVES AHEAD OF THE APPROACHING UPPER WAVE WILL BE POSSIBLE DURING
PEAK HEATING. THIS WILL ALSO PRESENT A CONTINUED RISK FOR SEVERE
STORMS WITH THE ADDED SUPPORT OF A STRONGER FLOW ALOFT AHEAD OF THE
APPROACHING UPPER WAVE. TEMPERATURES THROUGHOUT WILL BE DEPENDENT ON
THE TIMING OF THUNDERSTORM COMPLEXES...AND FOR NOW WILL STAY WITH
HIGHS IN THE 70S TO LOWER 80S AND LOWS IN THE 60S.
RAIN AND THUNDERSTORM CHANCES WILL CONTINUE FRIDAY NIGHT INTO
SATURDAY...BUT THE RISK FOR HEAVY RAIN SHOULD DIMINISH CONSIDERABLY
AS THE FEED OF GULF MOISTURE PUSHES EAST OF THE REGION. TEMPERATURES
MAY BE LIMITED TO HIGHS ONLY IN THE 60S AS CANADIAN HIGH PRESSURE
BUILDS IN UNDER A SHORT PERIOD OF W-NW FLOW ALOFT. EARLY NEXT
WEEK...TEMPERATURES SHOULD MODERATE AT LEAST BACK INTO THE 70S WITH
RAIN CHANCES RETURNING LATE TUESDAY. SHEETS
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1230 PM CDT WED MAY 29 2013
VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH 06Z/30. SATELLITE
SHOWS DIURNAL CUMULUS CLOUDS DEVELOPING WHICH SHOULD EVOLVE INTO
ISOLD TO SCATTERED SHRA/TSRA. IF A TSRA AFFECTS A TAF SITE A BRIEF
PERIOD OF MVFR CONDITION MAY OCCUR. AFT 06Z/30 VFR CONDITIONS
SHOULD CONTINUE BUT ANOTHER NOCTURNAL TSRA COMPLEX WILL DEVELOP IN
WESTERN IOWA THAT SLOWLY MOVES EAST. AFT 12Z/30 THIS TSRA COMPLEX
WILL AFFECT EASTERN IOWA AND EVENTUALLY NORTHERN ILLINOIS AND
POSSIBLY BRING MVFR CONDITIONS. ..08..
&&
.HYDROLOGY...
ISSUED AT 357 AM CDT WED MAY 29 2013
THE THREAT OF HEAVY RAINFALL AND FLASH FLOODING HAS DIMINISHED SOME
FOR TODAY...BUT WILL RETURN THURSDAY AND FRIDAY WHEN ADDITIONAL
LARGE THUNDERSTORM COMPLEXES WITH HEAVY RAINFALL APPEAR LIKELY. A
FLASH FLOOD WATCH MAY BE NEEDED...ESPECIALLY OVER THE FORECAST AREA
SOUTH OF I-80 THAT IS SATURATED FROM NUMEROUS ROUNDS OF HEAVY
RAINFALL OVER THE PAST 3 TO 5 DAYS.
MODERATE TO MAJOR RIVER FLOODING...AND IN SOME INSTANCES RECORD
FLOODING...WILL CONTINUE ALONG TRIBUTARY RIVERS IN EASTERN IA AND
FAR NORTHEAST MISSOURI. THE MISSISSIPPI RIVER IS EXPECTED TO SEE
MODERATE TO MAJOR FLOODING...ESPECIALLY DOWNSTREAM FROM MUSCATINE.
WITH ADDITIONAL RUNOFF FLOWING INTO THE RIVERS FROM LAST NIGHT/S
HEAVY RAIN...AND CHANGES IN FORECAST QPF...CONTINUED ADJUSTMENTS TO
BOTH THE MAGNITUDE AND TIMING OF RIVER FLOODING CAN BE EXPECTED IN
UPDATED WARNING STATEMENTS AND FORECASTS ISSUED LATER TODAY.
SHEETS
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...DLF
SHORT TERM...DLF
LONG TERM...SHEETS
AVIATION...08
HYDROLOGY...SHEETS
AREA FORECAST DISCUSSION...UPDATED
NWS TOPEKA KS
716 PM CDT THU MAY 30 2013
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 343 PM CDT THU MAY 30 2013
WATER VAPOR LOOP SHOWING CONVECTIVE SYSTEM OVER WESTERN MO MOVING
SLOWLY EWD AHEAD OF ONE MID-LEVEL TROUGH. HOWEVER...THERE IS A VERY
SHORT WAVELENGTH BETWEEN THAT TROUGH AND THE FOLLOWING IMPULSE THAT
APPEARS TO BE OVER WRN KS AT MID AFTERNOON. SCATTERED SHOWERS AND
THUNDERSTORMS HAVE FIRED OVER WRN KS AHEAD OF THIS FEATURE AND THEY
ARE MOVING EWD. SHORT RANGE MODEL GUIDANCE NOT RESOLVING THE
DETAILS OF THIS VERY WELL...HOWEVER THE 17Z HRRR DOES NOW HAVE A
LINE OF CONVECTION MOVING INTO CENTRAL KS BY 21Z. IT FORECASTS THIS
TO BREAK UP WITH THE REMNANTS MOVING ACROSS NORTHEAST KS DURING THE
EVENING...AND THEN ANOTHER SMALL CONVECTIVE SYSTEM MOVES SOUTHEAST
OUT OF NEBRASKA INTO NORTHEAST KS LATER TONIGHT. DO NOT HAVE HIGH
CONFIDENCE IN THIS SCENARIO...ALTHOUGH SOME TYPE OF SMALL MCS WOULD
APPEAR TO BE LIKELY IN CENTRAL/NORTHEAST KS LATER TONIGHT. THIS
POSSIBLE SYSTEM WOULD APPEAR TO MOVE THROUGH FAST ENOUGH AS TO NOT
CAUSE SIG PROBLEMS WITH HEAVY RAIN/FLOODING. EARLIER CONCERNS ABOUT
WARM AIR ADVECTION CAUSING LIFT AND THUNDERSTORM AREA WITH
POTENTIALLY HEAVY RAINFALL OVER EC KS TONIGHT ARE LESSENING AS
CONVECTIVE BOUNDARY SAGS WAY SOUTH INTO NORTHEAST OKLAHOMA.
THUS...HAVE CANCELLED FLASH FLOOD WATCH THAT WAS IN EFFECT FOR THIS
AFTERNOON...AND AM NOT PLANNING ON GOING OUT WITH A NEW ONE AT THIS
TIME. CONFIDENCE IN THE DETAILS OF PRECIPITATION EVOLUTION TONIGHT
IS NOT HIGH.
ON FRIDAY...FRONTAL BOUNDARY SHOULD MAKE IT FAR ENOUGH SOUTH BY
AFTERNOON THAT THE MAIN CHANCE OF THUNDERSTORM ACTIVITY WOULD BE IN
EC KS...MAINLY SOUTHEAST OF THE KANSAS TURNPIKE. LOWS TONIGHT
EXPECTED TO BE AROUND 60 OVER NC KS AND IN THE MID 60S EC. HIGHS ON
FRIDAY ARE FORECAST TO MAX OUT AROUND 80.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 343 PM CDT THU MAY 30 2013
DETAILS ONLY GET MURKIER FOR FRIDAY EVENING...BUT AT LEAST SOME
CHANCE SHOULD EXIST AHEAD OF THE SYNOPTIC BOUNDARY FOR SOUTHERN AND
EASTERN LOCATIONS. SUFFICIENT SHEAR AND INSTABILITY WOULD SUPPORT A
SEVERE CONCERN THROUGH THIS TIME AS WELL..BUT THE SOUTHEASTWARD
SHIFTING UPPER LOW SHOULD PUSH THE EFFECTIVE FRONT SOUTH OF THE AREA
BY DAWN. COLD AIR ADVECTION SETS IN FOR SATURDAY ON NORTHWEST
BREEZES WITH SOME STRATUS/STRATOCU DEVELOPING BY MID AFTERNOON.
WEAKENING WINDS AND CLEARING SKIES SPELL A COOL NIGHT SATURDAY
NIGHT. SURFACE RIDGE SETS UP FOR SUNDAY WITH LITTLE IF ANY
MODERATION TO HIGHS.
GULF MOISTURE DOES NOT GET COMPLETELY SCOURED OUT...AND BY LATE
MONDAY SOUTH WINDS AHEAD OF AN APPROACHING NORTHERN ROCKIES CYCLONE
WILL BRING THUNDERSTORM CHANCES BACK. BEST CHANCES LOOK TO BE
TUESDAY INTO TUESDAY NIGHT WITH GOOD MODEL AGREEMENT ON A MID LEVEL
WAVE PASSING. TEMPS SHOULD GENERALLY BE NEAR EARLY JUNE NORMALS SAVE
ANY DAYTIME MCS ACTIVITY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 709 PM CDT THU MAY 30 2013
BAND OF SHOWERS/ISOLATED THUNDERSTORMS WILL REMAIN GENERALLY NORTH
OF THE TAF SITES THROUGH 02Z...BUT SOUTHERN EXTENT OF THE LINE MAY
BARELY CLIP TERMINAL SITES AS IT MOVES EAST NORTHEAST WITH GUSTY
WEST WINDS AND BRIEF THUNDERSTORM. OTHERWISE VFR THROUGH THE
FCST...ALTHOUGH ELEVATED CONVECTION MAY DEVELOP NORTHWARD INTO THE
KFOE/KTOP TERMINAL SITES AFT 05Z BEFORE EXITING THE VCNTY
IN THE 10-14Z TIMEFRAME.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...60
LONG TERM...65
AVIATION...63
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1147 AM MDT WED MAY 29 2013
.UPDATE...
ISSUED AT 946 AM MDT WED MAY 29 2013
OVERALL THE CURRENT FORECAST THROUGH TONIGHT LOOKS ON
TRACK...FORESEE ONLY REFINING THE TIMING/AREA COVERAGE SOME BASED
ON THE LATEST OBS/MODEL DATA.
CURRENT VISIBLE SATELLITE SHOWS SKIES ARE CLEARING WITH CUMULUS
STARTING TO DEVELOP. UPPER AIR ANALYSIS PLACES A MID LEVEL SHORT
WAVE TROUGH JUST WEST OF THE AREA. AT THE SURFACE A STATIONARY
FRONT WAS OVER THE WESTERN PART OF THE AREA FROM ROUGHLY IMPERIAL
SOUTHWEST TO BETWEEN LIMON AND BURLINGTON. A DRY LINE WAS
SOUTHWEST OF THE AREA BETWEEN LA HUNTA AND LAMAR THEN CURVING
TO THE SOUTHEAST ALONG THE CO/KS BORDER.
AM THINKING THE STORMS SHOULD START TO DEVELOP AROUND 19Z ALONG
THE STATIONARY FRONT AND DRY LINE AND GENERALLY MOVE NORTH-NORTHEAST.
MEANWHILE A 700MB SHORT WAVE TROUGH MOVES IN FROM EASTERN COLORADO
WHICH MAY ALSO FIRE OFF CONVECTION BEHIND THE FRONT. VERY LARGE
HAIL IS POSSIBLE...ESPECIALLY THE FURTHER EAST ONE GOES ACROSS THE
TRI-STATE AREA...WITH THE LIKELIHOOD OF SEVERE HAIL INCREASING
THROUGH THE AFTERNOON AND EVENING. DUE TO MEAN STORM MOTIONS BEING
NEARLY PARALLEL TO THE FRONT THIS AFTERNOON AND EVENING THERE IS
A POSSIBILITY OF HEAVY RAINFALL WITH LOCALIZED FLOODING DUE TO
THUNDERSTORM TRAINING. DAMAGING WINDS WILL BE POSSIBLE WITH ANY
STORM...ESPECIALLY IF THE INDIVIDUAL STORMS MERGE INTO A SQUALL
LINE THIS AFTERNOON. AS MENTIONED EARLIER...THE TORNADO THREAT IS
A POSSIBILITY BUT THE BETTER ENVIRONMENT WILL BE FURTHER SOUTH
WHERE 0-1KM SHEAR WILL BE CLOSER TO 30KTS AND 0-3KM EHI WILL BE
NEAR 4 M2/S2. THE SEVERE WEATHER SHOULD BE OUT OF THE AREA BY OR
SHORTLY AFTER MIDNIGHT AS THE COLD FRONT PUSHES EAST. SOME
THUNDERSTORMS MAY REDEVELOP DURING THE OVERNIGHT HOURS AS AN UPPER
LEVEL SHORT WAVE TROUGH MOVES ACROSS THE AREA...BUT THESE STORMS
SHOULD NOT BECOME SEVERE.
A MULTIMEDIA BRIEFING IS AVAILABLE ON THE WFO GOODLAND HOMEPAGE AT
WEATHER.GOV/GLD CONCERNING THE SEVERE WEATHER THREAT.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 417 AM MDT WED MAY 29 2013
MAIN FORECAST CONCERN IS SIGNIFICANT WEATHER EXPECTED THROUGH
TONIGHT. SATELLITE SHOWING A PROGRESSIVE FLOW FROM THE PACIFIC INTO
NORTH AMERICA. MAIN FEATURE OF INTEREST IS STRONG AND DEVELOPING
UPPER SYSTEM APPROACHING FROM THE WEST. WARM FRONT NORTH OF THE
AREA.
MODELS INITIALIZED FINE AT JET LEVEL BUT WOULD HAVE TO GIVE A SLIGHT
EDGE TO THE GFS AND CANADIAN ON THE JET SEGMENT BEHIND INCOMING
TROUGH. EVEN CLOSE TO THE EVENT MODELS STILL HAVE TROUBLE WITH
INCOMING SHORTWAVE TROUGH. IT HAS BEEN REORGANIZING/DEVELOPING THIS
EVENING AND LOOKS LIKE IT WILL CONTINUE TO DO SO. THROUGH SATELLITE
AND UPPER AIR ANALYSIS...THE CANADIAN IS DOING SLIGHTLY BETTER THAN
THE GFS. EVOLVING SURFACE PATTERN GOING ON RIGHT NOW. RUC IS
CATCHING THINGS WELL. THEN THE CANADIAN AND ECMWF ARE NEXT IN LINE
AND MATCH UP WITH IT. THE CANADIAN...GFS AND ECMWF WERE DOING THE
BEST ON THE LOW LEVEL THERMAL FIELD.
TODAY/TONIGHT...AS HAS BEEN THE CASE THE LAST FEW DAYS THE MODELS
DEVELOP A MID/UPPER JET SEGMENT OVER THE CENTRAL AND EASTERN PORTION
OF THE FORECAST BY 18Z WITH THAT AREA BEING UNDER THE LEFT FRONT
QUADRANT. THE ECMWF HOLDS ONTO THIS OVER THE FORECAST AREA LONGER...
INTO THE EVENING...THAN THE OTHER MODELS. AS THE NIGHT HAS PROGRESSED
THE MODELS HAVE BEEN SLOWING THE ARRIVAL OF THE FRONT. FRONT LOOKS
TO BE NEAR OR JUST EAST OF THE COLORADO BORDER BY 00Z. IN ADDITION
TO THE JET STRONG MID LEVEL LIFT IS AROUND AS WELL. MODELS SHOWING
LITTLE TO NO CAP MY THE MIDDLE OF THE DAY. MAIN QUESTION WILL BE
HOW MUCH MOISTURE WILL THIS ALL HAVE TO WORK WITH. THAT MAY SLOW
DOWN THE ONSET OF THE PRECIPITATION BUT AM THINKING THE LIFT AND
INSTABILITY MAY OVERCOME THIS.
SO HAVE INSERTED POPS BEGINNING AT 15Z AND THEN RAMP THEM QUICKLY
IN THE AFTERNOON. THERE WILL BE A TIGHT GRADIENT OF POPS. IF THERE
IS ANY SLOWING...POPS WILL NEED TO BE PULLED BACK FURTHER WEST. AT
THIS TIME THE EASTERN HALF TO TWO THIRDS THROUGH TONIGHT WILL HAVE
A VERY GOOD CHANCE OF SEEING RAIN/THUNDERSTORMS. PARAMETERS POINT TO
THESE THUNDERSTORMS BECOMING SEVERE AND HAVE INSERTED SEVERE
WORDING FOR THIS AFTERNOON AND TONIGHT. IN ADDITION MODEL QPFS ARE
RATHER HIGH IN THE EASTERN HALF TO TWO THIRDS. NAM/GFS/SREF
PRECIPITABLE WATER VALUES ARE 1 TO 1.25 INCHES. DAY SHIFT MADE A
GOOD POINT WITH THE STORM MOTIONS IN ADVANCE OF THE FRONT
SUPPORTING TRAINING OF THE CELLS. SREF HAS A 30 PERCENT PROBABILITY
OF 1 INCH OF RAINFALL IN THE EAST. SO WENT AHEAD AND ADDED LOCALLY
HEAVY RAINFALL TO THE ABOVE MENTIONED AREA.
THE MOST WIDESPREAD ACTIVITY LOOKS TO END NEAR OR SHORTLY AFTER
06Z. BUT INCOMING JET AND ANOTHER SHORTWAVE TROUGH APPROACH FROM THE
WEST LATE IN THE NIGHT. SO SOME KIND OF CHANCE REMAINS THROUGH THE
NIGHT. NOT SURE ABOUT THE MAXES BUT MESOSCALE MODELS...ESPECIALLY
THE RUC...HAVE MAXES WARMER THAN WHAT I HAVE IN THERE. DID NUDGE
MAXES UP A LITTLE SINCE WARMER MAXES...IF NOT A LOT OF CLOUD COVER...
MAKE SENSE WITH THE SLOWER ARRIVAL OF THE FRONT.
THURSDAY/THURSDAY NIGHT...MODELS TAKE THE LEFT FRONT QUADRANT ACROSS
THE AREA DURING THE AFTERNOON AND EARLY EVENING WITH THE JET SEGMENT
NEAR OR OVER THE NORTHERN PORTION OF THE AREA THROUGH THE REST OF THE
NIGHT. THERE IS ALSO A RATHER STRONG PV ANOMALY WITH THIS. AIR MASS
IS UNSTABLE WITH GOOD LAPSE RATES. SO KEPT A LOW CHANCE OF
THUNDERSTORMS AROUND INTO THE EVENING. LOOK TO HAVE BREEZY OR NEAR
BREEZY WEST TO NORTHWEST WINDS. DEPENDING ON THE AMOUNT OF CLOUD
COVER AND PRECIPITATION...THESE WINDS MAY HELP TEMPERATURES CLIMB A
LITTLE MORE THAN ANTICIPATED. WINDS DIE OFF DURING THE FIRST PART OF
THE NIGHT AND THEN PICK A LITTLE MORE LATER. DEW POINTS WILL BE LOWER.
COULD BE RATHER COOL NIGHT.
FRIDAY/FRIDAY NIGHT...JET STARTS OFF OVER THE NORTHERN PORTION OF
THE AREA AND THEN SOUTH OF THE AREA DURING THE DAY. MODELS WANT TO
GENERATE SOME LIGHT QPF. HOWEVER...THERE IS A RATHER DEEP DRY LAYER
SO KEPT IT DRY AT THIS TIME. IT MAY BE POSSIBLE THAT COULD SEE
SPRINKLES. ONCE AGAIN LOOK TO HAVE BREEZY OR NEAR BREEZY WEST ACROSS
THE AREA. MODELS COOL OFF TEMPERATURES FROM THE PREVIOUS DAY BUT
THOSE WINDS MAY HELP WARM TEMPERATURES A LITTLE MORE. WINDS DIE OFF
MORE THAN THE PREVIOUS NIGHT AND LOOK TO ANOTHER RATHER COOL NIGHT.
.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 417 AM MDT WED MAY 29 2013
EXTENDED RANGE LOOKS TO BE SEASONABLE FOR THE BEGINNING OF JUNE.
PERIOD BEGINS ON SATURDAY WITH THE UPPER LOW THAT WILL BE OVER THE
CENTRAL PLAINS LATE THIS WEEK MOVING EAST INTO THE MIDWEST WHILE A
LONG WAVE RIDGE BUILDS ACROSS THE HIGH PLAINS BEHIND IT ON SUNDAY.
SOUTHERLY FLOW AT 850MB WILL BRING WARMER AIR UP FOR LATE IN THE
WEEKEND THROUGH MID-NEXT WEEK. ON MONDAY A SURFACE TROUGH/DRY LINE
WILL SET UP ALONG OR NEAR THE KANSAS-COLORADO BORDER. AT THE SAME
TIME A NUMBER OF WEAK SHORTWAVE TROUGHS MOVE UP FROM THE SOUTHWEST
TO NORTHEAST ACROSS THE CWA...WHICH ALONG WITH DIURNAL HEATING COULD
SET OFF SOME SHOWERS/STORMS ON MONDAY AND TUESDAY. TUESDAY WILL HAVE
HIGHS WELL ABOVE NORMAL...WITH THE GFS AND GEM PROJECTING 850MB
TEMPS IN EXCESS OF 30C. ECMWF IS A BIT MORE CONSERVATIVE...BUT EVEN
SO BELIEVE HIGHS ON TUESDAY WILL BE WELL INTO THE 90S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1142 AM MDT WED MAY 29 2013
A LOW PRESSURE SYSTEM WILL CONTINUE TO DEEPEN OVER THE REGION
TODAY...ALLOWING FOR UNSTABLE CONDITIONS AND SEVERE THUNDERSTORMS TO
DEVELOP. THUNDERSTORM INITIATION WILL OCCUR AROUND 19Z FOR KGLD AND
WILL APPROACH KMCK AROUND 21Z. THUNDERSTORMS WILL BE PRESENT
NEAR/OVER THE TAF SITES PRODUCING HEAVY RAIN...HAIL AND GUSTY WINDS.
VFR CONDITIONS SHOULD PREVAIL FOR BOTH TAF SITES WITH MVFR CEILINGS
IN THUNDERSTORMS. AS THE FRONT PASSES THROUGH THE REGION...WINDS
WILL SHIFT FROM THE SOUTH TO THE NORTHWEST BY 6Z. THUNDERSTORMS
WILL MOVE OUT OF THE AREA BY 6Z WITH CEILING CONDITIONS RETURNING TO
VFR FOR BOTH TAF SITES.
&&
.FIRE WEATHER...
ISSUED AT 417 AM MDT WED MAY 29 2013
FOR TODAY...MAY BE A BRIEF PERIOD OF LOW RELATIVE HUMIDITIES AND
WINDS. BUT THERE IS A HIGH DEGREE OF UNCERTAINTY OF BOUNDARY
POSITIONS. PLUS DO NOT EXPECT PRECIPITATION TO DEVELOP IN THE
AFTERNOON.
FOR THURSDAY...IF CURRENT FORECAST PANS OUT...MOST OF THE FORECAST
AREA WILL RECEIVE RAINFALL FROM TODAYS SYSTEM. EASTERN COLORADO
WILL GET THE LEAST WITH THE EASTERN HALF TO TWO THIRDS GETTING THE
MOST. THE REASON THIS IS MENTIONED IS BECAUSE WIND SPEEDS AND
RELATIVE HUMIDITIES COULD REACH CRITICAL RED FLAG CRITERIA OVER THE
WESTERN HALF. PLUS ADDITIONAL PRECIPITATION IS EXPECTED ON
THURSDAY. SO AT THIS TIME AM ANTICIPATING NO FIRE WEATHER HIGHLIGHTS
WITH EASTERN COLORADO HAVE THE BEST CHANCE.
FOR FRIDAY...LOWER RELATIVE HUMIDITIES AND GUSTY WEST TO NORTHWEST
WINDS WILL SPREAD OVER MORE OF THE FORECAST AREA THAN THE PREVIOUS
DAY. AGAIN WILL HAVE TO SEE HOW CURRENT PRECIPITATION FORECAST
WORKS OUT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...BULLER
LONG TERM...JJM
AVIATION...MK
FIRE WEATHER...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1014 AM MDT WED MAY 29 2013
.UPDATE...
ISSUED AT 946 AM MDT WED MAY 29 2013
OVERALL THE CURRENT FORECAST THROUGH TONIGHT LOOKS ON
TRACK...FORESEE ONLY REFINING THE TIMING/AREA COVERAGE SOME BASED
ON THE LATEST OBS/MODEL DATA.
CURRENT VISIBLE SATELLITE SHOWS SKIES ARE CLEARING WITH CUMULUS
STARTING TO DEVELOP. UPPER AIR ANALYSIS PLACES A MID LEVEL SHORT
WAVE TROUGH JUST WEST OF THE AREA. AT THE SURFACE A STATIONARY
FRONT WAS OVER THE WESTERN PART OF THE AREA FROM ROUGHLY IMPERIAL
SOUTHWEST TO BETWEEN LIMON AND BURLINGTON. A DRY LINE WAS
SOUTHWEST OF THE AREA BETWEEN LA HUNTA AND LAMAR THEN CURVING
TO THE SOUTHEAST ALONG THE CO/KS BORDER.
AM THINKING THE STORMS SHOULD START TO DEVELOP AROUND 19Z ALONG
THE STATIONARY FRONT AND DRY LINE AND GENERALLY MOVE NORTH-NORTHEAST.
MEANWHILE A 700MB SHORT WAVE TROUGH MOVES IN FROM EASTERN COLORADO
WHICH MAY ALSO FIRE OFF CONVECTION BEHIND THE FRONT. VERY LARGE
HAIL IS POSSIBLE...ESPECIALLY THE FURTHER EAST ONE GOES ACROSS THE
TRI-STATE AREA...WITH THE LIKELIHOOD OF SEVERE HAIL INCREASING
THROUGH THE AFTERNOON AND EVENING. DUE TO MEAN STORM MOTIONS BEING
NEARLY PARALLEL TO THE FRONT THIS AFTERNOON AND EVENING THERE IS
A POSSIBILITY OF HEAVY RAINFALL WITH LOCALIZED FLOODING DUE TO
THUNDERSTORM TRAINING. DAMAGING WINDS WILL BE POSSIBLE WITH ANY
STORM...ESPECIALLY IF THE INDIVIDUAL STORMS MERGE INTO A SQUALL
LINE THIS AFTERNOON. AS MENTIONED EARLIER...THE TORNADO THREAT IS
A POSSIBILITY BUT THE BETTER ENVIRONMENT WILL BE FURTHER SOUTH
WHERE 0-1KM SHEAR WILL BE CLOSER TO 30KTS AND 0-3KM EHI WILL BE
NEAR 4 M2/S2. THE SEVERE WEATHER SHOULD BE OUT OF THE AREA BY OR
SHORTLY AFTER MIDNIGHT AS THE COLD FRONT PUSHES EAST. SOME
THUNDERSTORMS MAY REDEVELOP DURING THE OVERNIGHT HOURS AS AN UPPER
LEVEL SHORT WAVE TROUGH MOVES ACROSS THE AREA...BUT THESE STORMS
SHOULD NOT BECOME SEVERE.
A MULTIMEDIA BRIEFING IS AVAILABLE ON THE WFO GOODLAND HOMEPAGE AT
WEATHER.GOV/GLD CONCERNING THE SEVERE WEATHER THREAT.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 417 AM MDT WED MAY 29 2013
MAIN FORECAST CONCERN IS SIGNIFICANT WEATHER EXPECTED THROUGH
TONIGHT. SATELLITE SHOWING A PROGRESSIVE FLOW FROM THE PACIFIC INTO
NORTH AMERICA. MAIN FEATURE OF INTEREST IS STRONG AND DEVELOPING
UPPER SYSTEM APPROACHING FROM THE WEST. WARM FRONT NORTH OF THE
AREA.
MODELS INITIALIZED FINE AT JET LEVEL BUT WOULD HAVE TO GIVE A SLIGHT
EDGE TO THE GFS AND CANADIAN ON THE JET SEGMENT BEHIND INCOMING
TROUGH. EVEN CLOSE TO THE EVENT MODELS STILL HAVE TROUBLE WITH
INCOMING SHORTWAVE TROUGH. IT HAS BEEN REORGANIZING/DEVELOPING THIS
EVENING AND LOOKS LIKE IT WILL CONTINUE TO DO SO. THROUGH SATELLITE
AND UPPER AIR ANALYSIS...THE CANADIAN IS DOING SLIGHTLY BETTER THAN
THE GFS. EVOLVING SURFACE PATTERN GOING ON RIGHT NOW. RUC IS
CATCHING THINGS WELL. THEN THE CANADIAN AND ECMWF ARE NEXT IN LINE
AND MATCH UP WITH IT. THE CANADIAN...GFS AND ECMWF WERE DOING THE
BEST ON THE LOW LEVEL THERMAL FIELD.
TODAY/TONIGHT...AS HAS BEEN THE CASE THE LAST FEW DAYS THE MODELS
DEVELOP A MID/UPPER JET SEGMENT OVER THE CENTRAL AND EASTERN PORTION
OF THE FORECAST BY 18Z WITH THAT AREA BEING UNDER THE LEFT FRONT
QUADRANT. THE ECMWF HOLDS ONTO THIS OVER THE FORECAST AREA LONGER...
INTO THE EVENING...THAN THE OTHER MODELS. AS THE NIGHT HAS PROGRESSED
THE MODELS HAVE BEEN SLOWING THE ARRIVAL OF THE FRONT. FRONT LOOKS
TO BE NEAR OR JUST EAST OF THE COLORADO BORDER BY 00Z. IN ADDITION
TO THE JET STRONG MID LEVEL LIFT IS AROUND AS WELL. MODELS SHOWING
LITTLE TO NO CAP MY THE MIDDLE OF THE DAY. MAIN QUESTION WILL BE
HOW MUCH MOISTURE WILL THIS ALL HAVE TO WORK WITH. THAT MAY SLOW
DOWN THE ONSET OF THE PRECIPITATION BUT AM THINKING THE LIFT AND
INSTABILITY MAY OVERCOME THIS.
SO HAVE INSERTED POPS BEGINNING AT 15Z AND THEN RAMP THEM QUICKLY
IN THE AFTERNOON. THERE WILL BE A TIGHT GRADIENT OF POPS. IF THERE
IS ANY SLOWING...POPS WILL NEED TO BE PULLED BACK FURTHER WEST. AT
THIS TIME THE EASTERN HALF TO TWO THIRDS THROUGH TONIGHT WILL HAVE
A VERY GOOD CHANCE OF SEEING RAIN/THUNDERSTORMS. PARAMETERS POINT TO
THESE THUNDERSTORMS BECOMING SEVERE AND HAVE INSERTED SEVERE
WORDING FOR THIS AFTERNOON AND TONIGHT. IN ADDITION MODEL QPFS ARE
RATHER HIGH IN THE EASTERN HALF TO TWO THIRDS. NAM/GFS/SREF
PRECIPITABLE WATER VALUES ARE 1 TO 1.25 INCHES. DAY SHIFT MADE A
GOOD POINT WITH THE STORM MOTIONS IN ADVANCE OF THE FRONT
SUPPORTING TRAINING OF THE CELLS. SREF HAS A 30 PERCENT PROBABILITY
OF 1 INCH OF RAINFALL IN THE EAST. SO WENT AHEAD AND ADDED LOCALLY
HEAVY RAINFALL TO THE ABOVE MENTIONED AREA.
THE MOST WIDESPREAD ACTIVITY LOOKS TO END NEAR OR SHORTLY AFTER
06Z. BUT INCOMING JET AND ANOTHER SHORTWAVE TROUGH APPROACH FROM THE
WEST LATE IN THE NIGHT. SO SOME KIND OF CHANCE REMAINS THROUGH THE
NIGHT. NOT SURE ABOUT THE MAXES BUT MESOSCALE MODELS...ESPECIALLY
THE RUC...HAVE MAXES WARMER THAN WHAT I HAVE IN THERE. DID NUDGE
MAXES UP A LITTLE SINCE WARMER MAXES...IF NOT A LOT OF CLOUD COVER...
MAKE SENSE WITH THE SLOWER ARRIVAL OF THE FRONT.
THURSDAY/THURSDAY NIGHT...MODELS TAKE THE LEFT FRONT QUADRANT ACROSS
THE AREA DURING THE AFTERNOON AND EARLY EVENING WITH THE JET SEGMENT
NEAR OR OVER THE NORTHERN PORTION OF THE AREA THROUGH THE REST OF THE
NIGHT. THERE IS ALSO A RATHER STRONG PV ANOMALY WITH THIS. AIR MASS
IS UNSTABLE WITH GOOD LAPSE RATES. SO KEPT A LOW CHANCE OF
THUNDERSTORMS AROUND INTO THE EVENING. LOOK TO HAVE BREEZY OR NEAR
BREEZY WEST TO NORTHWEST WINDS. DEPENDING ON THE AMOUNT OF CLOUD
COVER AND PRECIPITATION...THESE WINDS MAY HELP TEMPERATURES CLIMB A
LITTLE MORE THAN ANTICIPATED. WINDS DIE OFF DURING THE FIRST PART OF
THE NIGHT AND THEN PICK A LITTLE MORE LATER. DEW POINTS WILL BE LOWER.
COULD BE RATHER COOL NIGHT.
FRIDAY/FRIDAY NIGHT...JET STARTS OFF OVER THE NORTHERN PORTION OF
THE AREA AND THEN SOUTH OF THE AREA DURING THE DAY. MODELS WANT TO
GENERATE SOME LIGHT QPF. HOWEVER...THERE IS A RATHER DEEP DRY LAYER
SO KEPT IT DRY AT THIS TIME. IT MAY BE POSSIBLE THAT COULD SEE
SPRINKLES. ONCE AGAIN LOOK TO HAVE BREEZY OR NEAR BREEZY WEST ACROSS
THE AREA. MODELS COOL OFF TEMPERATURES FROM THE PREVIOUS DAY BUT
THOSE WINDS MAY HELP WARM TEMPERATURES A LITTLE MORE. WINDS DIE OFF
MORE THAN THE PREVIOUS NIGHT AND LOOK TO ANOTHER RATHER COOL NIGHT.
.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 417 AM MDT WED MAY 29 2013
EXTENDED RANGE LOOKS TO BE SEASONABLE FOR THE BEGINNING OF JUNE.
PERIOD BEGINS ON SATURDAY WITH THE UPPER LOW THAT WILL BE OVER THE
CENTRAL PLAINS LATE THIS WEEK MOVING EAST INTO THE MIDWEST WHILE A
LONG WAVE RIDGE BUILDS ACROSS THE HIGH PLAINS BEHIND IT ON SUNDAY.
SOUTHERLY FLOW AT 850MB WILL BRING WARMER AIR UP FOR LATE IN THE
WEEKEND THROUGH MID-NEXT WEEK. ON MONDAY A SURFACE TROUGH/DRY LINE
WILL SET UP ALONG OR NEAR THE KANSAS-COLORADO BORDER. AT THE SAME
TIME A NUMBER OF WEAK SHORTWAVE TROUGHS MOVE UP FROM THE SOUTHWEST
TO NORTHEAST ACROSS THE CWA...WHICH ALONG WITH DIURNAL HEATING COULD
SET OFF SOME SHOWERS/STORMS ON MONDAY AND TUESDAY. TUESDAY WILL HAVE
HIGHS WELL ABOVE NORMAL...WITH THE GFS AND GEM PROJECTING 850MB
TEMPS IN EXCESS OF 30C. ECMWF IS A BIT MORE CONSERVATIVE...BUT EVEN
SO BELIEVE HIGHS ON TUESDAY WILL BE WELL INTO THE 90S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 548 AM MDT WED MAY 29 2013
SIGNIFICANT SEVERE WEATHER EVENT TO DEVELOP ACROSS THE AREA THIS
AFTERNOON INTO THIS EVENING. IN GENERAL KMCK WILL HAVE THE GREATEST
THREAT OF HAVING MVFR OR LOWER CONDITIONS. UNTIL THEN GUSTY
SOUTHERLY WINDS WILL OCCUR AT BOTH SITES. FOR KGLD THUNDERSTORM
INITIATION WILL BE VERY NEAR TO THIS SITE. SO AT THIS TIME JUST
CHOSE TO PUT VCTS IN THE TAF. FOR KMCK...FELT MORE COMFORTABLE IN
PUTTING IN SUB VFR CONDITIONS LATER THIS AFTERNOON. HOWEVER...SOME
MODEL OUTPUT BRINGS IN THUNDERSTORMS SOONER THAN THAT. LATER
FORECASTS WILL HAVE TO FINE TUNE THIS. EVEN THOUGH NO VISIBILITY
RESTRICTIONS WERE PUT INTO THE KMCK TAF...VERY HEAVY RAINFALL
COULD DRAMATICALLY LOWER THE VISIBILITY. THAT WILL ALSO NEED TO BE
FINE TUNED AS WELL.
&&
.FIRE WEATHER...
ISSUED AT 417 AM MDT WED MAY 29 2013
FOR TODAY...MAY BE A BRIEF PERIOD OF LOW RELATIVE HUMIDITIES AND
WINDS. BUT THERE IS A HIGH DEGREE OF UNCERTAINTY OF BOUNDARY
POSITIONS. PLUS DO NOT EXPECT PRECIPITATION TO DEVELOP IN THE
AFTERNOON.
FOR THURSDAY...IF CURRENT FORECAST PANS OUT...MOST OF THE FORECAST
AREA WILL RECEIVE RAINFALL FROM TODAYS SYSTEM. EASTERN COLORADO
WILL GET THE LEAST WITH THE EASTERN HALF TO TWO THIRDS GETTING THE
MOST. THE REASON THIS IS MENTIONED IS BECAUSE WIND SPEEDS AND
RELATIVE HUMIDITIES COULD REACH CRITICAL RED FLAG CRITERIA OVER THE
WESTERN HALF. PLUS ADDITIONAL PRECIPITATION IS EXPECTED ON
THURSDAY. SO AT THIS TIME AM ANTICIPATING NO FIRE WEATHER HIGHLIGHTS
WITH EASTERN COLORADO HAVE THE BEST CHANCE.
FOR FRIDAY...LOWER RELATIVE HUMIDITIES AND GUSTY WEST TO NORTHWEST
WINDS WILL SPREAD OVER MORE OF THE FORECAST AREA THAN THE PREVIOUS
DAY. AGAIN WILL HAVE TO SEE HOW CURRENT PRECIPITATION FORECAST
WORKS OUT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...BULLER
LONG TERM...JJM
AVIATION...BULLER
FIRE WEATHER...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
553 AM MDT WED MAY 29 2013
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 417 AM MDT WED MAY 29 2013
MAIN FORECAST CONCERN IS SIGNIFICANT WEATHER EXPECTED THROUGH
TONIGHT. SATELLITE SHOWING A PROGRESSIVE FLOW FROM THE PACIFIC INTO
NORTH AMERICA. MAIN FEATURE OF INTEREST IS STRONG AND DEVELOPING
UPPER SYSTEM APPROACHING FROM THE WEST. WARM FRONT NORTH OF THE
AREA.
MODELS INITIALIZED FINE AT JET LEVEL BUT WOULD HAVE TO GIVE A SLIGHT
EDGE TO THE GFS AND CANADIAN ON THE JET SEGMENT BEHIND INCOMING
TROUGH. EVEN CLOSE TO THE EVENT MODELS STILL HAVE TROUBLE WITH
INCOMING SHORTWAVE TROUGH. IT HAS BEEN REORGANIZING/DEVELOPING THIS
EVENING AND LOOKS LIKE IT WILL CONTINUE TO DO SO. THROUGH SATELLITE
AND UPPER AIR ANALYSIS...THE CANADIAN IS DOING SLIGHTLY BETTER THAN
THE GFS. EVOLVING SURFACE PATTERN GOING ON RIGHT NOW. RUC IS
CATCHING THINGS WELL. THEN THE CANADIAN AND ECMWF ARE NEXT IN LINE
AND MATCH UP WITH IT. THE CANADIAN...GFS AND ECMWF WERE DOING THE
BEST ON THE LOW LEVEL THERMAL FIELD.
TODAY/TONIGHT...AS HAS BEEN THE CASE THE LAST FEW DAYS THE MODELS
DEVELOP A MID/UPPER JET SEGMENT OVER THE CENTRAL AND EASTERN PORTION
OF THE FORECAST BY 18Z WITH THAT AREA BEING UNDER THE LEFT FRONT
QUADRANT. THE ECMWF HOLDS ONTO THIS OVER THE FORECAST AREA LONGER...
INTO THE EVENING...THAN THE OTHER MODELS. AS THE NIGHT HAS PROGRESSED
THE MODELS HAVE BEEN SLOWING THE ARRIVAL OF THE FRONT. FRONT LOOKS
TO BE NEAR OR JUST EAST OF THE COLORADO BORDER BY 00Z. IN ADDITION
TO THE JET STRONG MID LEVEL LIFT IS AROUND AS WELL. MODELS SHOWING
LITTLE TO NO CAP MY THE MIDDLE OF THE DAY. MAIN QUESTION WILL BE
HOW MUCH MOISTURE WILL THIS ALL HAVE TO WORK WITH. THAT MAY SLOW
DOWN THE ONSET OF THE PRECIPITATION BUT AM THINKING THE LIFT AND
INSTABILITY MAY OVERCOME THIS.
SO HAVE INSERTED POPS BEGINNING AT 15Z AND THEN RAMP THEM QUICKLY
IN THE AFTERNOON. THERE WILL BE A TIGHT GRADIENT OF POPS. IF THERE
IS ANY SLOWING...POPS WILL NEED TO BE PULLED BACK FURTHER WEST. AT
THIS TIME THE EASTERN HALF TO TWO THIRDS THROUGH TONIGHT WILL HAVE
A VERY GOOD CHANCE OF SEEING RAIN/THUNDERSTORMS. PARAMETERS POINT TO
THESE THUNDERSTORMS BECOMING SEVERE AND HAVE INSERTED SEVERE
WORDING FOR THIS AFTERNOON AND TONIGHT. IN ADDITION MODEL QPFS ARE
RATHER HIGH IN THE EASTERN HALF TO TWO THIRDS. NAM/GFS/SREF
PRECIPITABLE WATER VALUES ARE 1 TO 1.25 INCHES. DAY SHIFT MADE A
GOOD POINT WITH THE STORM MOTIONS IN ADVANCE OF THE FRONT
SUPPORTING TRAINING OF THE CELLS. SREF HAS A 30 PERCENT PROBABILITY
OF 1 INCH OF RAINFALL IN THE EAST. SO WENT AHEAD AND ADDED LOCALLY
HEAVY RAINFALL TO THE ABOVE MENTIONED AREA.
THE MOST WIDESPREAD ACTIVITY LOOKS TO END NEAR OR SHORTLY AFTER
06Z. BUT INCOMING JET AND ANOTHER SHORTWAVE TROUGH APPROACH FROM THE
WEST LATE IN THE NIGHT. SO SOME KIND OF CHANCE REMAINS THROUGH THE
NIGHT. NOT SURE ABOUT THE MAXES BUT MESOSCALE MODELS...ESPECIALLY
THE RUC...HAVE MAXES WARMER THAN WHAT I HAVE IN THERE. DID NUDGE
MAXES UP A LITTLE SINCE WARMER MAXES...IF NOT A LOT OF CLOUD COVER...
MAKE SENSE WITH THE SLOWER ARRIVAL OF THE FRONT.
THURSDAY/THURSDAY NIGHT...MODELS TAKE THE LEFT FRONT QUADRANT ACROSS
THE AREA DURING THE AFTERNOON AND EARLY EVENING WITH THE JET SEGMENT
NEAR OR OVER THE NORTHERN PORTION OF THE AREA THROUGH THE REST OF THE
NIGHT. THERE IS ALSO A RATHER STRONG PV ANOMALY WITH THIS. AIR MASS
IS UNSTABLE WITH GOOD LAPSE RATES. SO KEPT A LOW CHANCE OF
THUNDERSTORMS AROUND INTO THE EVENING. LOOK TO HAVE BREEZY OR NEAR
BREEZY WEST TO NORTHWEST WINDS. DEPENDING ON THE AMOUNT OF CLOUD
COVER AND PRECIPITATION...THESE WINDS MAY HELP TEMPERATURES CLIMB A
LITTLE MORE THAN ANTICIPATED. WINDS DIE OFF DURING THE FIRST PART OF
THE NIGHT AND THEN PICK A LITTLE MORE LATER. DEWPOINTS WILL BE LOWER.
COULD BE RATHER COOL NIGHT.
FRIDAY/FRIDAY NIGHT...JET STARTS OFF OVER THE NORTHERN PORTION OF
THE AREA AND THEN SOUTH OF THE AREA DURING THE DAY. MODELS WANT TO
GENERATE SOME LIGHT QPF. HOWEVER...THERE IS A RATHER DEEP DRY LAYER
SO KEPT IT DRY AT THIS TIME. IT MAY BE POSSIBLE THAT COULD SEE
SPRINKLES. ONCE AGAIN LOOK TO HAVE BREEZY OR NEAR BREEZY WEST ACROSS
THE AREA. MODELS COOL OFF TEMPERATURES FROM THE PREVIOUS DAY BUT
THOSE WINDS MAY HELP WARM TEMPERATURES A LITTLE MORE. WINDS DIE OFF
MORE THAN THE PREVIOUS NIGHT AND LOOK TO ANOTHER RATHER COOL NIGHT.
.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 417 AM MDT WED MAY 29 2013
EXTENDED RANGE LOOKS TO BE SEASONABLE FOR THE BEGINNING OF JUNE.
PERIOD BEGINS ON SATURDAY WITH THE UPPER LOW THAT WILL BE OVER THE
CENTRAL PLAINS LATE THIS WEEK MOVING EAST INTO THE MIDWEST WHILE A
LONGWAVE RIDGE BUILDS ACROSS THE HIGH PLAINS BEHIND IT ON SUNDAY.
SOUTHERLY FLOW AT 850MB WILL BRING WARMER AIR UP FOR LATE IN THE
WEEKEND THROUGH MID-NEXT WEEK. ON MONDAY A SURFACE TROUGH/DRY LINE
WILL SET UP ALONG OR NEAR THE KANSAS-COLORADO BORDER. AT THE SAME
TIME A NUMBER OF WEAK SHORTWAVE TROUGHS MOVE UP FROM THE SOUTHWEST
TO NORTHEAST ACROSS THE CWA...WHICH ALONG WITH DIURNAL HEATING COULD
SET OFF SOME SHOWERS/STORMS ON MONDAY AND TUESDAY. TUESDAY WILL HAVE
HIGHS WELL ABOVE NORMAL...WITH THE GFS AND GEM PROJECTING 850MB
TEMPS IN EXCESS OF 30C. ECMWF IS A BIT MORE CONSERVATIVE...BUT EVEN
SO BELIEVE HIGHS ON TUESDAY WILL BE WELL INTO THE 90S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 548 AM MDT WED MAY 29 2013
SIGNIFICANT SEVERE WEATHER EVENT TO DEVELOP ACROSS THE AREA THIS
AFTERNOON INTO THIS EVENING. IN GENERAL KMCK WILL HAVE THE GREATEST
THREAT OF HAVING MVFR OR LOWER CONDITIONS. UNTIL THEN GUSTY
SOUTHERLY WINDS WILL OCCUR AT BOTH SITES. FOR KGLD THUNDERSTORM
INITIATION WILL BE VERY NEAR TO THIS SITE. SO AT THIS TIME JUST
CHOSE TO PUT VCTS IN THE TAF. FOR KMCK...FELT MORE COMFORTABLE IN
PUTTING IN SUB VFR CONDITIONS LATER THIS AFTERNOON. HOWEVER...SOME
MODEL OUTPUT BRINGS IN THUNDERSTORMS SOONER THAN THAT. LATER
FORECASTS WILL HAVE TO FINE TUNE THIS. EVEN THOUGH NO VISIBILITY
RESTRICTIONS WERE PUT INTO THE KMCK TAF...VERY HEAVY RAINFALL
COULD DRAMATICALLY LOWER THE VISIBILITY. THAT WILL ALSO NEED TO BE
FINE TUNED AS WELL.
&&
.FIRE WEATHER...
ISSUED AT 417 AM MDT WED MAY 29 2013
FOR TODAY...MAY BE A BRIEF PERIOD OF LOW RELATIVE HUMIDITIES AND
WINDS. BUT THERE IS A HIGH DEGREE OF UNCERTAINTY OF BOUNDARY
POSITIONS. PLUS DO NOT EXPECT PRECIPITATION TO DEVELOP IN THE
AFTERNOON.
FOR THURSDAY...IF CURRENT FORECAST PANS OUT...MOST OF THE FORECAST
AREA WILL RECEIVE RAINFALL FROM TODAYS SYSTEM. EASTERN COLORADO
WILL GET THE LEAST WITH THE EASTERN HALF TO TWO THIRDS GETTING THE
MOST. THE REASON THIS IS MENTIONED IS BECAUSE WIND SPEEDS AND
RELATIVE HUMIDITIES COULD REACH CRITICAL RED FLAG CRITERIA OVER THE
WESTERN HALF. PLUS ADDITIONAL PRECIPITATION IS EXPECTED ON
THURSDAY. SO AT THIS TIME AM ANTICIPATING NO FIRE WEATHER HIGHLIGHTS
WITH EASTERN COLORADO HAVE THE BEST CHANCE.
FOR FRIDAY...LOWER RELATIVE HUMIDITIES AND GUSTY WEST TO NORTHWEST
WINDS WILL SPREAD OVER MORE OF THE FORECAST AREA THAN THE PREVIOUS
DAY. AGAIN WILL HAVE TO SEE HOW CURRENT PRECIPITATION FORECAST
WORKS OUT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...JJM
AVIATION...BULLER
FIRE WEATHER...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
417 AM MDT WED MAY 29 2013
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 417 AM MDT WED MAY 29 2013
MAIN FORECAST CONCERN IS SIGNIFICANT WEATHER EXPECTED THROUGH
TONIGHT. SATELLITE SHOWING A PROGRESSIVE FLOW FROM THE PACIFIC INTO
NORTH AMERICA. MAIN FEATURE OF INTEREST IS STRONG AND DEVELOPING
UPPER SYSTEM APPROACHING FROM THE WEST. WARM FRONT NORTH OF THE
AREA.
MODELS INITIALIZED FINE AT JET LEVEL BUT WOULD HAVE TO GIVE A SLIGHT
EDGE TO THE GFS AND CANADIAN ON THE JET SEGMENT BEHIND INCOMING
TROUGH. EVEN CLOSE TO THE EVENT MODELS STILL HAVE TROUBLE WITH
INCOMING SHORTWAVE TROUGH. IT HAS BEEN REORGANIZING/DEVELOPING THIS
EVENING AND LOOKS LIKE IT WILL CONTINUE TO DO SO. THROUGH SATELLITE
AND UPPER AIR ANALYSIS...THE CANADIAN IS DOING SLIGHTLY BETTER THAN
THE GFS. EVOLVING SURFACE PATTERN GOING ON RIGHT NOW. RUC IS
CATCHING THINGS WELL. THEN THE CANADIAN AND ECMWF ARE NEXT IN LINE
AND MATCH UP WITH IT. THE CANADIAN...GFS AND ECMWF WERE DOING THE
BEST ON THE LOW LEVEL THERMAL FIELD.
TODAY/TONIGHT...AS HAS BEEN THE CASE THE LAST FEW DAYS THE MODELS
DEVELOP A MID/UPPER JET SEGMENT OVER THE CENTRAL AND EASTERN PORTION
OF THE FORECAST BY 18Z WITH THAT AREA BEING UNDER THE LEFT FRONT
QUADRANT. THE ECMWF HOLDS ONTO THIS OVER THE FORECAST AREA LONGER...
INTO THE EVENING...THAN THE OTHER MODELS. AS THE NIGHT HAS PROGRESSED
THE MODELS HAVE BEEN SLOWING THE ARRIVAL OF THE FRONT. FRONT LOOKS
TO BE NEAR OR JUST EAST OF THE COLORADO BORDER BY 00Z. IN ADDITION
TO THE JET STRONG MID LEVEL LIFT IS AROUND AS WELL. MODELS SHOWING
LITTLE TO NO CAP MY THE MIDDLE OF THE DAY. MAIN QUESTION WILL BE
HOW MUCH MOISTURE WILL THIS ALL HAVE TO WORK WITH. THAT MAY SLOW
DOWN THE ONSET OF THE PRECIPITATION BUT AM THINKING THE LIFT AND
INSTABILITY MAY OVERCOME THIS.
SO HAVE INSERTED POPS BEGINNING AT 15Z AND THEN RAMP THEM QUICKLY
IN THE AFTERNOON. THERE WILL BE A TIGHT GRADIENT OF POPS. IF THERE
IS ANY SLOWING...POPS WILL NEED TO BE PULLED BACK FURTHER WEST. AT
THIS TIME THE EASTERN HALF TO TWO THIRDS THROUGH TONIGHT WILL HAVE
A VERY GOOD CHANCE OF SEEING RAIN/THUNDERSTORMS. PARAMETERS POINT TO
THESE THUNDERSTORMS BECOMING SEVERE AND HAVE INSERTED SEVERE
WORDING FOR THIS AFTERNOON AND TONIGHT. IN ADDITION MODEL QPFS ARE
RATHER HIGH IN THE EASTERN HALF TO TWO THIRDS. NAM/GFS/SREF
PRECIPITABLE WATER VALUES ARE 1 TO 1.25 INCHES. DAY SHIFT MADE A
GOOD POINT WITH THE STORM MOTIONS IN ADVANCE OF THE FRONT
SUPPORTING TRAINING OF THE CELLS. SREF HAS A 30 PERCENT PROBABILITY
OF 1 INCH OF RAINFALL IN THE EAST. SO WENT AHEAD AND ADDED LOCALLY
HEAVY RAINFALL TO THE ABOVE MENTIONED AREA.
THE MOST WIDESPREAD ACTIVITY LOOKS TO END NEAR OR SHORTLY AFTER
06Z. BUT INCOMING JET AND ANOTHER SHORTWAVE TROUGH APPROACH FROM THE
WEST LATE IN THE NIGHT. SO SOME KIND OF CHANCE REMAINS THROUGH THE
NIGHT. NOT SURE ABOUT THE MAXES BUT MESOSCALE MODELS...ESPECIALLY
THE RUC...HAVE MAXES WARMER THAN WHAT I HAVE IN THERE. DID NUDGE
MAXES UP A LITTLE SINCE WARMER MAXES...IF NOT A LOT OF CLOUD COVER...
MAKE SENSE WITH THE SLOWER ARRIVAL OF THE FRONT.
THURSDAY/THURSDAY NIGHT...MODELS TAKE THE LEFT FRONT QUADRANT ACROSS
THE AREA DURING THE AFTERNOON AND EARLY EVENING WITH THE JET SEGMENT
NEAR OR OVER THE NORTHERN PORTION OF THE AREA THROUGH THE REST OF THE
NIGHT. THERE IS ALSO A RATHER STRONG PV ANOMALY WITH THIS. AIR MASS
IS UNSTABLE WITH GOOD LAPSE RATES. SO KEPT A LOW CHANCE OF
THUNDERSTORMS AROUND INTO THE EVENING. LOOK TO HAVE BREEZY OR NEAR
BREEZY WEST TO NORTHWEST WINDS. DEPENDING ON THE AMOUNT OF CLOUD
COVER AND PRECIPITATION...THESE WINDS MAY HELP TEMPERATURES CLIMB A
LITTLE MORE THAN ANTICIPATED. WINDS DIE OFF DURING THE FIRST PART OF
THE NIGHT AND THEN PICK A LITTLE MORE LATER. DEWPOINTS WILL BE LOWER.
COULD BE RATHER COOL NIGHT.
FRIDAY/FRIDAY NIGHT...JET STARTS OFF OVER THE NORTHERN PORTION OF
THE AREA AND THEN SOUTH OF THE AREA DURING THE DAY. MODELS WANT TO
GENERATE SOME LIGHT QPF. HOWEVER...THERE IS A RATHER DEEP DRY LAYER
SO KEPT IT DRY AT THIS TIME. IT MAY BE POSSIBLE THAT COULD SEE
SPRINKLES. ONCE AGAIN LOOK TO HAVE BREEZY OR NEAR BREEZY WEST ACROSS
THE AREA. MODELS COOL OFF TEMPERATURES FROM THE PREVIOUS DAY BUT
THOSE WINDS MAY HELP WARM TEMPERATURES A LITTLE MORE. WINDS DIE OFF
MORE THAN THE PREVIOUS NIGHT AND LOOK TO ANOTHER RATHER COOL NIGHT.
.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 417 AM MDT WED MAY 29 2013
EXTENDED RANGE LOOKS TO BE SEASONABLE FOR THE BEGINNING OF JUNE.
PERIOD BEGINS ON SATURDAY WITH THE UPPER LOW THAT WILL BE OVER THE
CENTRAL PLAINS LATE THIS WEEK MOVING EAST INTO THE MIDWEST WHILE A
LONGWAVE RIDGE BUILDS ACROSS THE HIGH PLAINS BEHIND IT ON SUNDAY.
SOUTHERLY FLOW AT 850MB WILL BRING WARMER AIR UP FOR LATE IN THE
WEEKEND THROUGH MID-NEXT WEEK. ON MONDAY A SURFACE TROUGH/DRY LINE
WILL SET UP ALONG OR NEAR THE KANSAS-COLORADO BORDER. AT THE SAME
TIME A NUMBER OF WEAK SHORTWAVE TROUGHS MOVE UP FROM THE SOUTHWEST
TO NORTHEAST ACROSS THE CWA...WHICH ALONG WITH DIURNAL HEATING COULD
SET OFF SOME SHOWERS/STORMS ON MONDAY AND TUESDAY. TUESDAY WILL HAVE
HIGHS WELL ABOVE NORMAL...WITH THE GFS AND GEM PROJECTING 850MB
TEMPS IN EXCESS OF 30C. ECMWF IS A BIT MORE CONSERVATIVE...BUT EVEN
SO BELIEVE HIGHS ON TUESDAY WILL BE WELL INTO THE 90S.
&&
.AVIATION....(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1113 PM MDT TUE MAY 28 2013
THE POTENTIAL FOR WIND SHEAR ALONG WITH OCCASIONALLY GUSTY SURFACE
WINDS EXISTS AS A STRONG LOW LEVEL SOUTHEASTERLY JET MOVES INTO
WEST CENTRAL KANSAS AND EAST CENTRAL COLORADO AS A WARM FRONT
PUSHES NORTH THROUGH THE CENTRAL HIGH PLAINS REGION. THIS SHOULD
AFFECT THE GLD TAF MORE THAN THE MCK TAF...BUT HAVE NOT INCLUDED
WIND SHEAR IN THE GLD TAF AT THIS TIME AS IT APPEARS THE SURFACE
WINDS MAY NOT COMPLETELY DECOUPLE FROM THE LOW LEVEL WINDS. THE
PRESSURE GRADIENT IS WEAKER AT MCK...SO DO NOT EXPECT TO SEE THE
SAME KIND OF WINDS THERE.
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD AT GLD WITH
SCATTERED THUNDERSTORMS DEVELOPING AFTER 18Z WEDNESDAY THAT WILL
MOVE ACROSS THE AREA BEFORE DISSIPATING AFTER 02Z.
CONDITIONS WILL INITIALLY BE VFR AT MCK...BUT ARE EXPECTED TO
BECOME MVFR BETWEEN 11Z-15Z DUE TO GREATER AVAILABLE LOW LEVEL
MOISTURE EXPECTED TO PRODUCE LOWER CLOUDS. VFR CONDITIONS WILL
RETURN AS LOWER CLOUDS DISSIPATE AFTER 15Z WITH SCATTERED
THUNDERSTORMS EXPECTED TO DEVELOP AFTER 20Z...CONTINUING THROUGH
ABOUT 04Z.
&&
.FIRE WEATHER...
ISSUED AT 417 AM MDT WED MAY 29 2013
FOR TODAY...MAY BE A BRIEF PERIOD OF LOW RELATIVE HUMIDITIES AND
WINDS. BUT THERE IS A HIGH DEGREE OF UNCERTAINTY OF BOUNDARY
POSITIONS. PLUS DO NOT EXPECT PRECIPITATION TO DEVELOP IN THE
AFTERNOON.
FOR THURSDAY...IF CURRENT FORECAST PANS OUT...MOST OF THE FORECAST
AREA WILL RECEIVE RAINFALL FROM TODAYS SYSTEM. EASTERN COLORADO
WILL GET THE LEAST WITH THE EASTERN HALF TO TWO THIRDS GETTING THE
MOST. THE REASON THIS IS MENTIONED IS BECAUSE WIND SPEEDS AND
RELATIVE HUMIDITIES COULD REACH CRITICAL RED FLAG CRITERIA OVER THE
WESTERN HALF. PLUS ADDITIONAL PRECIPITATION IS EXPECTED ON
THURSDAY. SO AT THIS TIME AM ANTICIPATING NO FIRE WEATHER HIGHLIGHTS
WITH EASTERN COLORADO HAVE THE BEST CHANCE.
FOR FRIDAY...LOWER RELATIVE HUMIDITIES AND GUSTY WEST TO NORTHWEST
WINDS WILL SPREAD OVER MORE OF THE FORECAST AREA THAN THE PREVIOUS
DAY. AGAIN WILL HAVE TO SEE HOW CURRENT PRECIPITATION FORECAST
WORKS OUT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...JJM
AVIATION...LOCKHART
FIRE WEATHER...BULLER
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
139 AM EDT WED MAY 29 2013
.SYNOPSIS...
HIGH PRESSURE WILL BECOME ANCHORED OFF THE MID ATLANTIC COAST
OVERNIGHT THROUGH THE NEXT SEVERAL DAYS. SUMMERLIKE...GENERALLY
DRY CONDITIONS WILL PREVAIL FROM WEDNESDAY INTO THE UPCOMING
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE LATEST RADAR AND SATELLITE DEPICT A LINE OF TSTMS CROSSING THE
BAY AND APPROACHING THE LOWER MD EASTERN SHORE. THIS LINE HAS THE
POTENTIAL TO INITIALLY BE STRONG AS WEAK SHORTWAVE ENERGY COMBINES
WITH MODEST INSTABILITY. HOWEVER...THE LATEST HRRR (23Z) AND SPC
MESOANALYSIS SUGGEST INSTABILITY DECLINES W-E ACROSS THE EASTERN
SHORE HENCE TSTMS ARE EXPECTED TO WEAKEN AS THEY MOVE E. AN
ISOLATED TS IS POSSIBLE ACROSS THE NORTHERN NECK AND VA EASTERN
SHORE THROUGH THE REMAINDER OF THE EVENING...BUT MOST AREAS
ELSEWHERE WILL REMAIN DRY. SKIES CLEAR OUT FROM SW TO NE AFTER
MIDNIGHT. MILD WITH LOWS MAINLY FROM THE LWR TO MID 60S.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY/...
SUMMERLIKE PATTERN LOOKS TO DEVELOP. MODELS IN GOOD AGREEMENT
THAT THE 500 MB RIDGE ALOFT WILL SLOWLY BUILD ON WED AND BECOME
CENTERED ACRS SE VA AND EASTERN NC THU/FRI WITH HEIGHTS AVERAGING
588-590 DM. SFC HIGH PRESSURE WILL BE NEARLY STATIONARY WELL OFF
THE MID ATLC/SE COAST. SUMMER- LIKE CONDITIONS WILL DOMINATE WITH
HIGHS GENLY RANGING FROM THE MID 80S NEAR THE COAST TO THE UPPER
80S TO LOWER 90S INLAND (LOCALLY IN THE UPPER 70S AT THE BEACHES
OF THE EASTERN SHORE WHERE FLOW BACKS TO SSE DURING THE AFTN).
LACK OF ANY REAL TRIGGER WITH THE WARM POOL ALOFT WILL LEAD TO
WEAK LAPSE RATES ALOFT AND LITTLE CHC FOR ANY PCPN. A VERY
ISOLATED LATE AFTN/EVENING TSTM CAN`T BE RULED OUT WITH THE STRONG
SFC HEATING ...BUT COVERAGE IS EXPECTED TO BE 14% OR LESS. THE SKY
WILL AVERAGE OUT PARTLY/MOSTLY SUNNY. AIRMASS WILL NOT BE THAT
HUMID...AS OCEAN TEMPS ARE STILL QUITE COOL AND WITH AFTN
MIXING...EXPECT DEW PTS TO DROP TO THE LWR 60S DURING THE HEAT OF
THE AFTN (MID-UPR 60S IN THE MORNING HRS). SO WHILE IT WILL BE A
MARGINALLY HOT PERIOD...PEAK HEAT INDICES WILL GENLY BE ABOUT THE
SAME AS THE ACTUAL AIR TEMPERATURES. LOWS TEMPERATURES WILL
AVERAGE IN THE MID 60S...WITH UPPER 60S MORE COMMON IN THE URBAN
CENTERS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
ABOVE NORMAL TEMPS TO CONTINUE THROUGH THE WEEKEND BEFORE A COLD
FRONT CROSSES THE REGION MONDAY INTO TUESDAY.
MUCH BETTER AGREEMENT AMONG OPERATIONAL GUIDANCE IN THE EXTENDED WRT
CNTRL CONUS TROUGH OPENING UP AND PROGRESSING EWD. MODELS CONTINUE
TO STRUGGLE WITH SEVERAL PIECES OF ENERGY DIVING DOWN THE BACKSIDE
OF THE UPPER TROUGH OVER THE PLAINS. MEAN FRONTAL POSITION SAT
MORNING EXPECTED TO BE IN THE VICINITY OF THE GREAT
LAKES...STRETCHING SWWD INTO SRN NM. WAVY UPPER LEVEL PATTERN
EXPECTED TO PRODUCE SEVERAL WAVES ALONG THE SFC FRONT AS IT SLOWLY
PROGRESSES EWD. WHILE LATEST GFS AND EURE DERIVE UPPER LEVEL ENERGY
FROM DIFFERENT SOURCES...MEDIUM RANGE MODELS IN GOOD AGREEMENT WITH
EJECTING A SHORTWAVE EWD FROM THE LOWER MO RIVER VALLEY SUN
AFTERNOON. SHORTWAVE THEN FORECAST TO PHASE WITH UPPER TROUGH AS IT
TRAVERSES THE ERN STATES...REACHING THE LOCAL AREA MONDAY AFTERNOON.
MEANWHILE...UPPER/SFC HIGH PRESSURE WILL BE PUSHED FARTHER OFFSHORE
AS THE TROUGH APPROACHES. THE RESULT WILL BE DEEP SWLY FLOW AND
MOISTURE ADVECTION OVER THE MID ATLANTIC. DEEP MOISTURE EXPECTED AS
PRECIP WATER VALUES APPROACH 2 INCHES (+2 STD DEV) MON AFTERNOON.
PREVIOUSLY MENTIONED WEAKNESS UNDERCUTTING THE RIDGE EXPECTED TO
REMAIN WELL OFFSHORE. MODELS IN FAIR AGREEMENT (GFS ~ 6 HOURS
SLOWER) WITH TIMING OF THE FRONT MON AFTERNOON THROUGH MON NIGHT.
WHILE ITS STILL DAY 7...POTENTIAL FOR ONE OR MORE FRONTAL WAVES AND
DEEP MOISTURE COULD PRODUCE LOCALLY HEAVY RAINFALL ACROSS THE REGION
(WHICH IS NOT UNCHARACTERISTIC FOR THIS TIME OF YEAR). THETA-E
ADVECTION AND TEMPS IN THE LOW/MID 80S WILL MAINTAIN A MARGINALLY
UNSTABLE AIRMASS FOR THUNDERSTORM ACTIVITY. EXTENDED RANGE MODELS
SUGGEST BLOCKING OVER THE NRN ATLANTIC MAY CAUSE THE TROUGH TO HANG
UP ALONG THE COAST WITH SHOWERS POSSIBLY CONTINUING INTO TUES.
WARM/UNSTABLE AIRMASS WITH STEEP LOW LEVEL LAPSE RATES WILL PROVIDE
FOR AFTERNOON CU SAT-SUN. HOWEVER...NEAR SEASONABLE PRECIP
WATERS...COOL OCEAN TEMPS (DEWPOINTS IN THE LOW/MID 60S) AND A LACK
OF UPPER LEVEL SUPPORT (WEAK FLOW) WILL LIMIT AFTERNOON
CONVECTION...EVEN WITH THE PRESENCE OF A WEAK LEE SIDE TROUGH. THUS
HAVE CAPPED AFTERNOON POPS AT 10-14 PCT AND OVERNIGHT POPS AT 10
PCT. DAYTIME TEMPS +1 STD DEV FORECAST THROUGH SUNDAY. SLIGHTLY
COOLER MONDAY (LOW/MID 80S) AND TUESDAY (UPPER 70S/LOW 80S).
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS ACROSS AREA TERMINALS THIS MORNING...WITH SIMILAR
CONDITIONS EXPECTED THROUGHOUT THE UPCOMING TAF PERIOD. HIGH
PRESSURE WL BECOME ANCHORED JUST OFFSHORE FOR THE LATTER HALF OF
THE WEKEK. EXPECT S-SW WINDS TO INCREASE BY MIDDAY AS DIURNAL
MIXING RESUMES, WITH WINDS QUICKLY DIMINISHING AFTER SUNSET.
APART FROM SOME SCT CU (MAINLY ACROSS COASTAL TERMINALS), EXPECT
MAINLY CLR CONDS AND DRY WX THROUGH EARLY THURSDAY.
OUTLOOK: HIGH PRESSURE REMAINS DOMINATE WX FEATURE ACROSS THE
REGION. ONLY REAL POTENTIAL CIG/VSBY RESTRICTION THE NEXT FEW DAYS
COMING IN PATCHY LOW STRATUS/SHALLOW GROUND FOG (MIFG). OTW, DRY
WX LOOKS TO PERSIST AT LEAST LATE SUNDAY OR MONDAY AHEAD OF AN
APPROACHING COLD FRONT.
&&
.MARINE...
WARM FRONT HAS LIFTED OVER THE WATER THIS AFTERNOON WITH S/SW WINDS
AOB 15 KT IN THE BAY AND AOB 20 KT COASTAL WATERS POST FRONTAL.
GRADIENT BETWEEN STRONG LOW PRESSURE OVER THE MIDWEST AND HIGH
PRESSURE OVER THE WRN ATLANTIC WILL RESULT IN INCREASING WINDS ALOFT
OVER THE WATERS. WAA AND A STRONG LOW LEVEL INVERSION WILL INHIBIT
THESE HIGHER VELOCITY WINDS FROM REACHING THE WATER. HOWEVER...WINDS
OVER THE BAY MAY STILL GUST OVER 15 KT AT TIMES THROUGH
TONIGHT...ESPECIALLY WITH SLY CHANNELING. WAVEWATCH GUIDANCE BRINGS
IN 5 FT SEAS 20 NM OUT TONIGHT...BUT LOOKS LIKE IT MAY BE OVERDONE.
NO SCA HEADLINES ANTICIPATED ATTM TONIGHT. THEREAFTER...AN EXTENDED
PERIOD OF HIGH PRESSURE/FAIR WEATHER (SUB SCA CONDITIONS) EXPECTED
THROUGH THE UPCOMING WEEKEND. S/SW WINDS AOB 15 KT. WAVES 1 TO 2 FT
AND SEAS 2 TO 4 FT.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...LKB
NEAR TERM...AJZ/LKB
SHORT TERM...LKB
LONG TERM...SAM
AVIATION...MAM
MARINE...SAM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
808 PM EDT THU MAY 30 2013
LATEST UPDATE...
MESOSCALE DISCUSSION/AVIATION
.MESOSCALE DISCUSSION...
ISSUED AT 808 PM EDT THU MAY 30 2013
LATEST DATA SHOWS A SHORTWAVE HEADING NORTHEAST FROM CENTRAL
ILLINOIS HEADING TOWARD CNTL LOWER TOWARD 06Z. WHILE THE DEEP
LAYER SHEAR WAS LARGELY BELOW 25 KNOTS MOST OF THE AFTERNOON THE
SPC EMC RAP DATA SHOWS IT HAS INCREASED TO 25 TO 35 KNOT BY 7 PM
AND SHOULD REMAIN BETWEEN 25-35 KNOTS THROUGH MIDNIGHT. THE MIXED
LAYER CAPE AT 7 PM WAS AROUND 1500 J/KG BUT AS THE EVENING
CONTINUES THAT SHOULD DECREASE TO UNDER 500 J/KG BY MIDNIGHT. THE
LOW LEVEL JET AXIS AT 7 PM WAS OVER CNTL WI AND W IL. BY 9 PM THE
CORE OF THE LOW LEVEL JET INCREASES TO 50 KNOTS OVER CENTRAL WI
WHILE A SECONDARY CORE MOVES ON SHORE NORTH OF MKG. ALL OF THIS
SUGGESTS TO ME THERE WILL BE BETTER DYNAMICS MOVING INTO SOUTHWEST
LOWER MICHIGAN OVER AFTER 9 PM BUT THE INSTABILITY DECREASES
SIGNIFICANTLY. I WOULD EXPECT THE PULSE CONVECTION CURRENTLY GOING
ON TO WEAKEN SIGNIFICANTLY DUE TO THE DECREASE IN CAPE. A STRONGER
SHORTWAVE WILL MOVE INTO THE AREA DURING THE EARLY MORNING HOURS
OF FRIDAY... THAT MAY BRING IN ADDITIONAL CONVECTION WELL AFTER
MIDNIGHT.
&&
.SYNOPSIS...
ISSUED AT 345 PM EDT THU MAY 30 2013
A DEEP TROUGH OVER THE PLAINS CONTINUES TO SWING NE. A ROUND OF
SHOWERS AND THUNDERSTORMS WILL AFFECT SOUTHWEST LOWER MICHIGAN THIS
AFTERNOON THROUGH THE EVENING. SEVERE THUNDERSTORMS ARE CERTAINLY
POSSIBLE WITH ADDITIONAL WAVES ON FRIDAY AND SATURDAY. DAMAGING WIND
GUSTS AND LARGE HAIL ARE THE MAIN THREATS...BUT A SLIGHT RISK FOR
TORNADOES ALSO EXISTS. HEAVY RAINFALL IS ALSO POSSIBLE.
A MOIST UNSTABLE AIRMASS WILL REMAIN IN PLACE THROUGH SATURDAY WITH
HIGHS IN THE 80S AND LOWS IN THE 60S. THE COLD FRONT FINALLY SWEEPS
THROUGH LATE SATURDAY...SUNDAY LOOKS COOL WITH LIGHT RAIN WHILE THE
BEGINNING OF NEXT WEEK SHOULD BE COOL AND DRY WITH SHORTWAVE RIDGING
IN PLACE. ANOTHER DISTURBANCE APPROACHING FROM THE NORTHERN PLAINS
WEDNESDAY BRINGS THE NEXT CHANCE FOR RAIN.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 345 PM EDT THU MAY 30 2013
THE SHORT TERM PERIOD LOOKS RATHER ACTIVE WITH A PERSISTENT SVR WX
RISK AND HEAVY RAIN THREAT THROUGH SATURDAY EVENING.
THE ONGOING SCATTERED DIURNAL/PULSE VARIETY STORMS SHOULD CONTINUE
THIS EVENING THEN DECREASE AROUND SUNSET. A FEW BRIEF/ISOLATED SVR
STORMS CANNOT BE RULED OUT GIVEN THE MODERATE INSTABILITY WITH ML
CAPES AROUND 2000 J/KG.
ADDITIONAL STORMS ARE EXPECTED TO DEVELOP OVERNIGHT AS A NEGATIVE
TILT SHORTWAVE ROTATES NEWD AROUND THE NRN PLAINS UPPER LOW TOWARD
WI. WILL HAVE THE HIGHEST POPS FOR THE OVERNIGHT PERIOD IN THE WRN
CWFA WHICH WILL BE CLOSER TO THE APCHG SHORTWAVE AND ON THE NOSE OF
THE STRENGTHENING 50 KT LOW LEVEL JET. SOME ISOLATED SVR WX ALSO
SEEMS POSSIBLE FROM THE LATE NIGHT ROUND OF STORMS IN WRN LWR MI
SINCE DEEP LAYER /0-6KM/ SHEAR VALUES INCREASE TO 40-45 KTS AFTER
06Z.
AS THE UPPER LOW OVER THE NRN PLAINS MOVES SLOWLY EAST TO WI BY SAT
EVENING... OUR SYNOPTIC PATTERN CHANGES LITTLE AND REMAINS CONDUCIVE
TO ROUNDS OF TSTMS WITH THE POTENTIAL OF SVR WX AND HEAVY RAINS.
OCCASIONAL SHORTWAVES/VORT MAXIMA MOVING THROUGH THE SW FLOW ALOFT
WILL CONTINUE TO INTERACT WITH THE VERY WARM/MOIST FLOW OFF THE GULF
WITH SFC DEW POINTS OF 65 TO 70 AND MODERATE INSTABILITY. THE SVR
WX/HVY RN THREAT SHOULD END SATURDAY NIGHT WITH THE PASSAGE OF THE
SFC COLD FRONT.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 345 PM EDT THU MAY 30 2013
CHILLY AIR ARRIVES FOR THE END OF THE WEEKEND AS THE UPPER TROUGH
SWINGS THROUGH. AND EVEN THOUGH THE COLD FRONT WILL BE
THROUGH...BELIEVE WE WILL SEE SCATTERED SHOWERS LINGER INTO SUNDAY
UNDER THE UPPER TROUGH. LOWERED MAX TEMPS AS SOME AREAS MAY
STRUGGLE TO REACH 60...AND TWEAKED POPS UP SLIGHTLY.
COOL AND DRY AIR SITS OVER THE REGION FOR MONDAY AND TUESDAY WITH
CANADIAN HIGH PRESSURE MOVING IN. DAYTIME TEMPS MAINLY 65 TO 70.
THEN A SLOW WARM UP BEGINS BY THE MIDDLE OF THE WEEK AS THE HIGH
PUSHES TO OUR EAST AND RETURN FLOW SETS UP.
ANOTHER UPPER LOW IS PROGGED TO BE MOVING INTO THE NORTHERN PLAINS
BY WED. TIMING IS SOMEWHAT UNCERTAIN...BUT THIS SHOULD EVENTUALLY
BRING MORE GULF MOISTURE INTO THE GREAT LAKES AND CHANCES FOR
SHOWERS SHOULD INCREASE WED INTO THU.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 808 PM EDT THU MAY 30 2013
THE CONVECTION ON GOING THIS EVENING SHOULD HAVE LITTLE IMPACT ON
TAF SITES SINCE THE STORMS ARE WIDELY SCATTERED. HOWEVER... EARLY
FRIDAY MORNING IT MAY BE A DIFFERENT STORY. AS THE UPPER TROUGH
GETS CLOSER TO MICHIGAN THE LOW LEVEL JET RAMPS UP AND DEEP
LAYERED MOISTURE INCREASE I EXPECT A LARGE AREA OF SHOWERS TO MOVE
INTO THE AREA AND REMAIN IN PLACE THROUGH MOST OF FRIDAY. IF THAT
HAPPENS THAT WILL LIMIT THE INSTABILITY FOR THUNDERSTORMS. WITH ALL
THE SHOWERS AROUND MVFR CIGS/VSBY SHOULD PREVAIL.
&&
.MARINE...
ISSUED AT 345 PM EDT THU MAY 30 2013
SMALL CRAFT ADVISORIES REMAIN IN EFFECT THROUGH SATURDAY MORNING DUE
TO CONTINUED STRONG SOUTHERLY FLOW. HIGHEST WAVES WILL BE NORTH OF
GRAND HAVEN WHICH IS WHERE BEACH HAZARD STATEMENTS ARE ALSO IN
EFFECT. THE STRONG WIND SHOULD HELP KEEP THE FOG THREAT DOWN AS HIGH
SFC DEW POINT AIR INTERACTS WITH THE COLD LAKE WATERS. IF
PERIODS/AREAS OF LIGHTER WINDS DO OCCUR... THE DENSE FOG THREAT MAY
RISE AGAIN.
&&
.HYDROLOGY...
ISSUED AT 345 PM EDT THU MAY 30 2013
SEVERAL RIVER ADVISORIES ARE IN EFFECT FOR NEAR BANKFULL LEVELS.
ADDITIONAL RAINFALL AMOUNTS THROUGH SATURDAY EVENING MAY EXCEED TWO
INCHES IN PLACES. URBAN AND SMALL STREAM FLOODING WILL CERTAINLY BE
POSSIBLE... AND SOME OF THE LARGER RIVERS COULD BEGIN TO FLOOD IN A
FEW DAYS DEPENDING ON THE COVERAGE/PLACEMENT OF THE HEAVIER RAIN
AMOUNTS THROUGH SATURDAY EVENING. THIS WILL BE MONITORED CLOSELY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT THROUGH FRIDAY AFTERNOON FOR MIZ037-043-
050.
LM...SMALL CRAFT ADVISORY UNTIL 8 AM EDT SATURDAY FOR LMZ844>849.
&&
$$
MESOSCALE...WDM
SYNOPSIS...EBW
SHORT TERM...MEADE
LONG TERM...JK
AVIATION...WDM
HYDROLOGY...MEADE
MARINE...MEADE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
356 PM EDT WED MAY 29 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 354 PM EDT WED MAY 29 2013
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW RDG AXIS MOVING
INTO THE UPR GRT LKS DOWNSTREAM OF DEEPENING UPR TROF OVER THE
ROCKIES. ALTHOUGH SOME LO CLDS LINGER WITH LLVL MSTR SHOWN ON LOCAL
12Z RAOBS...COMBINATION OF SUBSIDENCE/LLVL ACYC FLOW ASSOCIATED WITH
RDG AXIS AND ARRIVAL OF VERY DRY AIR ABV THE SHALLOW MSTR AS SHOWN
ON THE 12Z MPX RAOB IS BRINGING DRY WX TO UPR MI. AT MID AFTN...THE
LO CLDS ARE FINALLY MIXING OUT FAIRLY STEADILY. FARTHER TO THE
SW...A PAIR OF SHRTWVS LIFTING NEWD OUT OF THE ROCKIES TROF ARE
BRINGING SOME SHRA/TS TO COME AREAS IN THE PLAINS...ESPECIALLY OVER
IOWA INTO SE MN AHEAD OF SFC-85 WARM FNT.
MAIN FCST CONCERNS TNGT INTO THU WL BE SHRA/TS CHCS ASSOCIATED WITH
RETURNING H85 WARM FNT AND SHRTWVS LIFTING NEWD OUT OF THE ROCKIES
TROF.
TNGT...MODELS ARE IN VERY GOOD AGREEMENT SHOWING CORE OF MID LVL DRY
AIR OVER THE CWA EARLY THIS EVNG UNDER UPR RDG AXIS SHIFTING TO THE
NE WITH APRCH OF WARM FNT TO THE SW. ALTHOUGH THE EARLY EVNG WL
LIKELY BE DRY...EXPECT INCRSG SHRA/TS CHCS BY 03Z WITH APRCH OF
SHRTWV NOW CAUSING SHRA/TS IN IOWA AS WELL AS AXIS OF HIER H85
DEWPTS AT NOSE OF STRENGTHENING H85 LLJ PUSHING KINX AT IWD TO 36 BY
06Z PER GFS FCST SDNGS. SINCE THE SHRTWV/MOISTENING ARE FCST TO
IMPACT MAINLY THE W HALF OF THE CWA...EXPECT THE HIER POPS IN THAT
AREA. IN FACT...THE ERN ZNS MAY REMAIN COMPLETELY DRY WITH KINX FCST
NO HIER THAN ABOUT 25 AT ERY THRU 12Z THU. FCST SDNGS INDICATE
STABILITY WL BE TOO MARGINAL FOR SVR STORMS...WITH SSI NO LOWER THAN
ABOUT -1C AND MUCAPE NO HIER THAN 300-350 J/KG WITH NARROW SKINNY
CAPE. EXPECT THE LOWEST MIN TEMPS OVER THE E CLOSER TO DEPARTING DRY
AIRMASS. AREAS OF FOG ARE LIKELY TO FORM IN THIS AREA UNDER THE MORE
PERSISTENT MID LVL DRY AIR.
THU...AS WARM FNT SHIFTS TO THE N ON THU...EXPECT BULK OF LINGERING
MRNG SHRA/TS OVER MAINLY THE W TO DIMINISH/END. QUESTION THEN
BECOMES WHETHER ADDITIONAL CONVECTION WL FIRE IN THE WARM SECTOR AFT
MRNG LO CLDS DSPT WITH DAYTIME HEATING/MIXING. THE BEST CHC FOR AFTN
SHRA/TS WL BE PROBABLY BE OVER THE W...UNDER LOWER HGTS CLOSER TO
CLOSED LO FCST TO DRIFT NWD THRU THE PLAINS. BUT EVEN THERE...GFS
FCST SDNGS HINT AT SUBSIDENCE INVRN IN THE H75-8 LYR THAT MIGHT
INHIBIT CONVECTION FOR AWHILE. IN FACT...BULK OF NUMERICAL GUIDANCE
SHOWS NO SHRA/TS DVLPG UNTIL 21Z...WHEN SFC TEMPS ARE LIKELY TO RISE
WELL INTO THE 80S UNDER H85 TEMPS IN THE 16-17C RANGE. MODIFIED GFS
FCST SDNG AT IWD FOR T/TD 85/60 YIELDS SBCAPE NEAR 1250 J/KG.
UNIDIRECTIONAL SSW FLOW AND SFC-6KM BULK SHEAR IN THE 20-30KT RANGE
AS WELL AS HI FRZG LVL/WBLB ZERO OF 13.7K FT/12.6K FT WOULD INDICATE
SVR THREAT IS FAIRLY SMALL. SINCE WARM FNT WL PROBABLY STALL OVER NW
LK SUP...PAINTED THE HIER POPS OVER THE KEWEENAW CLOSER TO THIS
BNDRY. SFC-6KM SHEAR IS FCST A BIT HIER IN THIS AREA AND UP TO 40
KTS...BUT LO CLDS SHOULD BE MORE PERSISTENT/STABILITY LOWER OVER THE
KEWEENAW.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 354 PM EDT WED MAY 29 2013
WARMER THAN NORMAL TEMPERATURES AND ACTIVE WEATHER EXPECTED THROUGH
THE END OF THE WORK WEEK AHEAD OF A LOW PRESSURE SYSTEM SHIFTING
EASTWARD FROM THE PLAINS. A COOLING TREND IS EXPECTED OVER THE
WEEKEND WITH NEAR NORMAL TEMPERATURES EXPECTED EARLY NEXT
WEEK...HOWEVER OVERNIGHT LOWS ARE EXPECTED TO BE QUITE COOL EARLY
NEXT WEEK WITH INLAND AREAS LIKELY REACHING THE LOW TO MID 30S.
THURSDAY NIGHT THROUGH SATURDAY...UPPER LEVEL 500MB CLOSED LOW AND
ASSOCIATED SURFACE LOW PRESSURE SYSTEM CENTERED OVER THE DAKOTAS
THURSDAY NIGHT WILL DRIFT SLOWLY EASTWARD INTO WESTERN MN BY
THURSDAY NIGHT. THIS WILL KEEP UPPER MI IN WARM MOIST SOUTHERLY
FLOW. THE BETTER MOISTURE TRANSPORT INTO THE REGION IS PROGGED TO
OCCUR THURSDAY NIGHT THROUGH EARLY FRIDAY MORNING...AS PRESSURE
GRADIENT IS INCREASED BETWEEN THE TROUGH TO THE WEST AND RIDGE TO
THE EAST. UPPER MI IS ON THE NORTHERN FRINGES OF THIS PRESSURE
GRADIENT...DIFFLUENT REGION...ALLOWING WIND SPEEDS TO DECREASE OVER
UPPER MI. AS A RESULT...850MB CONVERGENCE IS ENHANCED OVER NORTHERN
WI AND UPPER MI PROVIDING ENOUGH FORCING TO INCREASE THE CHANCE OF
SHOWERS AND THUNDERSTORMS ACROSS THE REGION. MUCAPE VALUES ARE
PROGGED TO BE AROUND 500-600 J/KG WHICH MAY BE ENHANCED A BIT AS
500MB SHORTWAVE ROTATES THROUGH THE REGION THURSDAY NIGHT. THE
SURFACE LOW AND UPPER LEVEL LOW WILL THEN SHIFT FROM WESTERN MN
FRIDAY MORNING INTO WI AND UPPER MI BY SATURDAY AFTERNOON. DURING
THIS TIME PERIOD THE BETTER CHANCES FOR PRECIPITATION WILL SHIFT
EASTWARD...REMAINING OVER MAINLY EASTERN UPPER MI AND MOST OF LOWER
MI AS THE PRESSURE GRADIENT AND AFOREMENTIONED CONVERGENCE ALSO
SHIFTS EASTWARD. ENOUGH MOISTURE WILL REMAIN IN PLACE OVER MUCH OF
UPPER MI ALONG WITH COOLER AIR MOVING IN THROUGH THE DAY
SATURDAY...TO KEEP THE CHANCE OF SHOWERS AND THUNDERSTORMS IN THE
FORECAST.
SATURDAY NIGHT THROUGH SUNDAY...THE LOW PRESSURE SYSTEM OVER UPPER
MI SATURDAY NIGHT IS EXPECTED TO CONTINUE TO TREK EASTWARD SHIFTING
TO SOUTHERN ONTARIO AND SOUTHERN QUEBEC THROUGH SUNDAY AFTERNOON. AS
THIS HAPPENS...UPPER MI WILL BE PLACED ON THE BACK SIDE OF THE LOW
PRESSURE SYSTEM ALLOWING COOLER AIR TO PUSH INTO THE AREA. ENOUGH
WRAP AROUND MOISTURE WILL LINGER THROUGH SUNDAY AFTERNOON AND
EVENING TO KEEP INCREASED CLOUD COVER OVER THE REGION ALONG WITH THE
CHANCE OF SHOWERS. WHEN PLOTTING 1000-500MB OMEGA ON PLAN VIEW AND
CROSS SECTIONS...INCREASED RH VALUES AND FORCING ARE COLLOCATED OVER
MUCH OF THE UPPER PENINSULA THROUGH SUNDAY AFTERNOON. AS WAS THE
CASE OVER THE LAST FEW SHIFTS...THE GFS TRIES TO PULL DRY AIR INTO
THE REGION MUCH FASTER THAN THE EC/GEM...THEREFORE...WILL KEEP
INCREASED CLOUD COVER IN THE FORECAST INTO THE LATE AFTERNOON INTO
EARLY SUNDAY EVENING. THE GFS WOULD HAVE ALL CLOUD COVER OUT OF THE
AREA BETWEEN 12 AND 18Z SUNDAY.
SUNDAY NIGHT THROUGH WEDNESDAY...IN THE WAKE OF THE UPPER LEVEL
500MB LOW AND SURFACE LOW...EXPECT AN UPPER LEVEL 500MB RIDGE AND
SURFACE HIGH TO BUILD EASTWARD FROM THE PLAINS SUNDAY NIGHT REACHING
THE UPPER GREAT LAKES REGION BY LATE MONDAY MORNING. THE RIDGE WILL
REMAIN IN PLACE THROUGH TUESDAY EVENING...KEEPING CONDITIONS DRY AND
SKIES MOSTLY SUNNY. SUNDAY NIGHT INTO MONDAY NIGHT...OVERNIGHT LOWS
AREA EXPECTED TO BE FAIRLY COLD FOR THIS TIME OF YEAR AS 850MB TEMPS
AREA EXPECTED TO DROP TO AROUND 0C TO 2C. THIS COUPLED WITH CALM
WINDS...CLEAR SKIES AND DRY AIR...WILL ALLOW FOR MAXIMUM RADIATIONAL
COOLING. AREAS INLAND WEST COULD FALL TO NEAR FREEZING SUNDAY NIGHT
WHILE THE INLAND EAST AREAS COULD SEE NEAR FREEZING TEMPERATURES
MONDAY NIGHT AS THE HIGH PRESSURE CENTER SHIFTS EASTWARD. THE NEXT
AREA OF LOW PRESSURE DEVELOPING OVER SOUTHERN CANADA AND THE
NORTHERN ROCKIES MONDAY AFTERNOON WILL SHIFT SLOWLY EASTWARD
REACHING WESTERN UPPER MI BY LATE TUESDAY NIGHT INTO WEDNESDAY
MORNING. SIGNIFICANT TIMING AND SYSTEM INTENSITY DIFFERENCES EXIST
FROM MODEL TO MODEL AND FROM MODEL RUN TO MODEL RUN CAUSING A BELOW
AVERAGE CONFIDENCE LEVEL IN THE FORECAST FOR WEDNESDAY...THEREFORE
HAVE DECIDED TO LEAN TOWARD A CONSENSUS OF THE MODELS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 125 PM EDT WED MAY 29 2013
EXPECT LINGERING SC/MVFR CIGS AT CMX/SAW TO BREAK AND GIVE WAY TO
VFR CONDITIONS IN THE NEXT FEW HRS WITH LARGER SCALE SUBSIDENCE/
DRYING IN THE PRESENCE OF DAYTIME HEATING/MIXING. A DISTURBANCE
MOVING IN FM THE SW WL BRING THE THREAT OF SOME SHRA AND POSSIBLY A
TS TO MAINLY IWD AND CMX TNGT. WITH NOCTURNAL COOLING AND RETURNING
MSTR...EXPECT CONDITIONS TO DETERIORATE TO IFR/MVFR. ALTHOUGH
DAYTIME HEATING/MIXING WL BRING ABOUT IMPROVEMENT ON THU...THE LO
CLDS/MVFR CIGS MAY BE MORE PERSISTENT AT CMX WITH AN UPSLOPE SE WIND
COMPONENT CLOSER TO WARM FNT JUST N OF UPR MI.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 354 PM EDT WED MAY 29 2013
WITH GENERALLY WEAK PRES GRADIENT AND STABLE CONDITIONS OVER LAKE
SUPERIOR...EXPECT WINDS TO BE UNDER 25KT THRU THE WEEK. WIDESPREAD
FOG IS LIKELY...ESPECIALLY AFTER RAINFALL OCCURS OVER THE LAKE. AT
LEAST PATCHY DENSE FOG IS LIKELY INTO SAT. HIGH PRESSURE WILL MOVE
INTO THE AREA SUNDAY NIGHT AND REMAIN OVERHEAD THROUGH LATE TUESDAY
NIGHT...KEEPING WINDS VARIABLE AND LESS THAN 25 KNOTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KEC
AVIATION...KC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
559 AM CDT WED MAY 29 2013
.UPDATE...
12Z AVIATION DISCUSSION ADDED BELOW.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 400 AM CDT WED MAY 29 2013
A VERY VOLATILE WATER VAPOR IMAGE AND H5 PATTERN IS IN PLACE THIS
MORNING AS A NEGATIVELY TILTED TROUGH SITS FROM NEAR YELLOW STONE
SOUTHEAST TO THE BIG BEND REGION OF TEXAS. CONVECTION ACROSS THE
PLAINS YESTERDAY AND OVERNIGHT HAS LEFT MULTIPLE SHORT WAVES/MCVS
LITTERED ACROSS NATIONS MIDSECTION. DURING THE DAY...THE MAIN TROUGH
WILL MIGRATE E/NE ACROSS THE PLAINS...AND BY THE END OF THE PERIOD
THE TROUGH WILL STRETCH FROM A DEVELOPING CLOSED LOW OVER THE BLACK
HILLS SOUTHEAST TOWARD NE TEXAS.
AT 330 AM...THE WARM WAS JUST PASSING THROUGH FORT DODGE IN IOWA AND
HAS ACTUALLY BEGUN TO PICK UP SOME MOMENTUM TOWARD THE NORTH IN THE
LAST FEW HOURS. BASED ON THE RAP...THIS BOUNDARY WILL BE NEAR I-90
AT 15Z...BY 18Z IT SHOULD BE WORKING ITS WAY THROUGH THE TWIN CITIES
BEFORE BECOMING STATIONARY AT 00Z FROM A SFC LOW OVER NORTH CENTRAL
NEB...NORTHEAST THROUGH ABERDEEN AND UP TOWARD LAKE OF THE WOODS.
FOR THIS FORECAST...FAVORED A NAM/ECMWF BLEND FOR HANDLING OF LARGE
SCALE FEATURES SUCH AS SHORTWAVES AND THE LLJ...WHILE A BLEND OF THE
HI-RES CAMS WERE USED TO TRY AND ADD DETAIL TO THE POP FORECAST.
BASED ON THAT...WHAT FOLLOWS IS THE CURRENT THINKING IS OF 330 AM
FOR WHAT WILL HAPPEN TODAY.
FOR THE WARM FRONT COMING NORTH...IS LOOKING LIKE CONVECTIVE
ACTIVITY WILL BE SCATTERED IN NATURE...AS H85 LLJ IS ACTUALLY
SOMEWHAT DIFFLUENT OVER MN...WITH ONE BRANCH SPLITTING OF FROM IOWA
INTO SODAK...WITH THE REST OF THE JET FANNING OUT TOWARD THE NE
ACROSS MN INTO WI. THE HRRR AND OTHER CAMS ALONG WITH THE RAP IS
SHOWING A BATCH OF ELEVATED SHOWERS AND STORMS DEVELOPING EARLY THIS
MORNING NORTH OF THE BOUNDARY AND HEADING TOWARD SE MN BY THE EARLY
AFTERNOON. THIS SEEMS TO BE IN RESPONSE TO A SHORTWAVE NOTED ON
WATER VAPOR CURRENTLY WEST OF OMAHA THAT THE RAP DRAGS NE TOWARD SE
MN THROUGH THE MORNING. THE HRRR IS BY FAR THE MOST AGGRESSIVE WITH
THIS CONVECTION AT THE MOMENT...BUT OUTSIDE OF SOME POTENTIAL FOR
HAIL...THE SEVERE THREAT LOOKS LIMITED WITH THIS BATCH OF
CONVECTION...IF IT DOES FORM.
FOR THE SEVERE THREAT...ATTENTION REALLY TURNS TO ERN SODAK/WRN MN
THIS AFTERNOON. WITH THE NAM/ECMWF SHOWING THE LLJ ANGLING BACK NW
INTO SODAK IN RESPONSE TO HEIGHT FALLS ALOFT...THIS SHOULD LEAD TO
THE INITIATION OF MORE SURFACE BASED CONVECTION SOMEWHERE NEAR THE
RETREATING WARM FRONT IN ERN SODAK/WRN MN. FORECAST SOUNDINGS FROM
THE RAP/NAM SHOW ATMO REMAINING CAPPED ACROSS WRN MN UNTIL ABOUT
21Z...AT WHICH POINT YOU ARE DEALING WITH AROUND 1500 J/KG OF SBCAPE
IN A WEAKLY CAPPED...STRONGLY SHEARED /ESPECIALLY IN THE LOWEST 3
KM/ ENVIRONMENT. NMM/ARW BASED CAMS SHOW LITTLE CONVECTION
DEVELOPING THROUGH 21Z...BUT QUICKLY GENERATE CONVECTION AFTER
21Z...SO WAITED TO INTRODUCE ANY LIKELY POPS UNTIL 21Z. SEEING TWO
CAMPS IN THE CAMS FOR HOW CONVECTION DEVELOPS THIS AFTERNOON...WITH
THE ARW AND NSSL-WRF GENERATING STORMS OVER WRN MN...WHILE THE NMM
AND SPCWRF GENERATE CONVECTION OVER ERN SODAK. THIS IDEA FOR
ACTIVITY STARTING OUT WEST THIS AFTERNOON IS FURTHER SUPPORTED BY
THE SPC SSEO...WHICH SHOWS NEIGHBORHOOD PROBABILITIES FOR UPDRAFT
HELICITY AND UPDRAFT STRENGTH BEING MAXIMIZED OVER ERN SODAK INTO
WRN MN...WITH VERY LITTLE ACTIVITY BEING NOTED FROM SRN INTO ERN MN
AND WRN WI THIS AFTERNOON. GIVEN DEGREE OF LOW LEVEL SHEAR...THERE
WILL BE THE THREAT FOR TORNADIC ACTIVITY WHILE THE STORMS AREA
DISCRETE...BUT DO EXPECT STORMS THIS AFTERNOON TO GROW
UPSCALE...WITH A HAIL/WIND THREAT CONTINUING INTO THE NIGHT.
FOR TONIGHT...WHAT HAPPENS WITH CONVECTION THIS AFTERNOON WILL PLAY
A LARGE ROLE IN WHAT HAPPENS TONIGHT. WITHIN THE CAMS...WE ARE AGAIN
LOOKING AT TWO CAMPS. THE NMM AND SPCWRF DO NOT BRING THE DAKOTA
CONVECTION INTO MN...WHILE SENDING ANOTHER MCS RACING ACROSS
IOWA...KEEPING MUCH OF THE MPX CWA DRY. THE ARW AND NSSL-WRF CONGEAL
THE AFTERNOON CELLS IN THE WEST INTO A LINE...AND TRACK THAT COMPLEX
OF STORMS EAST ACROSS THE STATE THROUGH THE NIGHT. GIVEN EXPECTED
EVOLUTION OF THE LLJ FROM THE ECMWF/NAM...FAVOR THE ARW/NSSL-WRF
CAMP...WITH A COMPLEX OF STORMS WORKING EAST ACROSS THE AREA THROUGH
THE NIGHT...WITH CONVECTIVE COVERAGE AND INTENSITY SLOWLY
DIMINISHING AFTER 6Z.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 400 AM CDT WED MAY 29 2013
CUTOFF UPPER CIRCULATION DEVELOPS AND LINGERS ACROSS THE HIGH
PLAINS AND WESTERN GREAT LAKES INTO THE COMING WEEKEND. AS THE
UPPER LOW TAKES FORM OVER THE NORTHERN PLAINS THROUGH THURSDAY...
A BELT OF FASTER WESTERLY FLOW ASSOCIATED WITH A SHORT WAVE
TROUGH WILL MOVE EAST FROM THE CENTRAL PLAINS TO THE MIDWEST.
CLOUDS WILL REMAIN ABUNDANT OVER THE REGION...AND WILL LIMIT
SIGNIFICANT DESTABILIZATION. HOWEVER...LARGE SCALE ASCENT FROM
THE INCOMING SHORT WAVE AND STEEPENING MID LEVEL LAPSE WILL LIKELY
SUPPORT SOME STRONG TO SEVERE STORMS ACROSS CENTRAL AND SOUTHERN
MINNESOTA THURSDAY AFTERNOON AND THURSDAY NIGHT. THE SURFACE LOW
WILL DEEPEN AND OCCLUDE IN EASTERN NORTH DAKOTA INTO THURSDAY
NIGHT...AND WILL HELP PUSH THE COLD FRONT EAST INTO CENTRAL
MINNESOTA. WE SHOULD SEE HIGH POPS INTO THURSDAY AFTERNOON AS
THIS SYSTEM MOVES THROUGH...AND MAINLY OVER EASTERN AREAS INTO
THURSDAY NIGHT AHEAD OF COLD FRONT. HAIL AND STRONG WINDS WILL BE
THE MAIN THREATS...ALONG WITH HEAVY RAIN. WILL TRAIL POPS OFF TO
THE WEST DURING THE AFTERNOON. THE 00Z ECMWF IS MOST CONSISTENT
WITH DRIVING A DRY SLOT NORTHEAST OVER THE AREA INTO
FRIDAY...LIMITING SIGNIFICANT CONVECTION FURTHER EAST IN THE
REMNANT WARM SECTOR INTO WESTERN WISCONSIN. THIS WILL LIMIT SEVERE
WEATHER DEVELOPMENT ON FRIDAY...WITH THE DAY 3 OUTLOOK MAINLY
SOUTHEAST OF OUR CWA.
SYSTEM SLOW TO MOVE THROUGH THE AREA...WITH COLD AIR CIRCULATING
OVER THE REGION WELL INTO THE WEEKEND. EXPECTING DRIER CONDITIONS
DEVELOPING SATURDAY NIGHT AND LINGERING INTO MONDAY. TEMPERATURES
WILL RANGE SOME 5 TO 10 DEGREES BELOW AVERAGE THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 559 AM CDT WED MAY 29 2013
WARM FRONT ACROSS CENTRAL IOWA THIS MORNING WILL HEAD NORTH TODAY.
DESPITE CONVECTIVE CLOUD DEBRIS COMING OVERHEAD THIS
MORNING...ENOUGH BREAKS HAVE DEVELOPED WEST OF THE RETREATING
STRATUS DECK OVER ERN MN/WRN WI TO GET SOME DENSE FOG GOING ACROSS
MN. GIVEN THE CIRRUS BLOCKING THE SUN...THIS MAY SLOW THE
IMPROVEMENTS SOME NOTED IN THE STC/AXN/RWF TAFS. RAP/NAM
INDICATING POTENTIAL FOR THIS FOG TO LIFT INTO A STRATUS LAYER
THIS MORNING THAT WILL THEN TRACK NORTH WITH THE WARM FRONT...SO
WILL HAVE TO WATCH FOR THAT IN THE MORNING. BEHIND THE WARM
FRONT...MOIST/UNSTABLE AIRMASS WILL BE IN PLACE...THOUGH NAM/RAP
SOUNDINGS SHOW ATMO REMAINING CAPPED UNTIL 20Z...SO HELD OFF ON
ANY TS MENTION UNTIL AFTER THEN. BECAUSE OF THIS CAP...CURRENT
THINKING IS THE HRRR IS TOO AGGRESSIVE WITH TSRA GENERATION
BETWEEN 15Z AND 20Z. FOR THE THUNDER...FOLLOWED THE TREND OF THE
ARW FOR TIMING THUNDER THROUGH. EXPECT STORMS TO INITIATE IN WRN
MN THIS AFTERNOON...AND WORK EAST DURING THE EVENING. OUTSIDE OF
THAT...WILL HAVE TO WATCH A COUPLE OF POTENTIAL SHOWER AREAS THIS
MORNING. FIRST IS THUNDERSTORMS CURRENTLY WEST OF SIOUX FALLS.
MOST GUIDANCE HAS KEPT THIS AREA WEST OF TERMINALS...BUT THEY
COULD WORK INTO THE AXN AREA LATER THIS MORNING...SO HAVE A VCSH
MENTION THERE. OTHER AREA OF SHOWERS FOR THIS MORNING IS JUST
GETTING GOING EAST OF OMAHA...AND WILL TRACK NORTHEAST TOWARD
EAU...WHERE A VCSH WAS MENTIONED AROUND 18Z.
KMSP...AFTER VALLEY FOG AND BR BURNS OFF THIS MORNING...WILL HAVE
TO SEE IF SOME SUB 017 STRATUS WORKS UP WITH THE WARM FRONT.
MODERATE CONFIDENCE AT BEST ON THIS HAPPENING...BUT WITH LAMP
GUIDANCE SHOWING MVFR CIGS THROUGH 18Z...DECIDED TO KEEP IT. LOTS
OF UNCERTAINTY WITH THUNDER POTENTIAL TODAY. HRRR RUNS CONTINUE TO
BE AGGRESSIVE WITH TSRA MOVING INTO THE FIELD AS EARLY AS 19Z...BUT
RAP SOUNDINGS CONTINUE TO BE CAPPED THROUGH ABOUT 21Z...SO WILL
CONTINUE TO PLAY UP THE IDEA THAT STORMS INITIATE AROUND 20Z OVER
WRN MN...AND PUSH INTO THE TWIN CITIES AREA AFTER 00Z. THOUGH
GIVEN DEGREE OF INSTABILITY...IF SOMETHING WERE TO BREAK THROUGH
THE CAP...THINGS WOULD GO QUICKLY.
/OUTLOOK FOR KMSP/
THU...MVFR OR LOWER CIGS LIKELY. SHRA/TSRA LIKELY. WINDS S 15-20
KTS.
FRI...MVFR OR LOWER CIGS LIKELY. CHANCE SHRA/TSRA. WINDS SW 10-15
KTS.
SAT...MVFR CIGS POSSIBLE. CHANCE SHRA/TSRA. WINDS WNW 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...DWE
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
411 AM CDT WED MAY 29 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 400 AM CDT WED MAY 29 2013
A VERY VOLATILE WATER VAPOR IMAGE AND H5 PATTERN IS IN PLACE THIS
MORNING AS A NEGATIVELY TILTED TROUGH SITS FROM NEAR YELLOW STONE
SOUTHEAST TO THE BIG BEND REGION OF TEXAS. CONVECTION ACROSS THE
PLAINS YESTERDAY AND OVERNIGHT HAS LEFT MULTIPLE SHORT WAVES/MCVS
LITTERED ACROSS NATIONS MIDSECTION. DURING THE DAY...THE MAIN TROUGH
WILL MIGRATE E/NE ACROSS THE PLAINS...AND BY THE END OF THE PERIOD
THE TROUGH WILL STRETCH FROM A DEVELOPING CLOSED LOW OVER THE BLACK
HILLS SOUTHEAST TOWARD NE TEXAS.
AT 330 AM...THE WARM WAS JUST PASSING THROUGH FORT DODGE IN IOWA AND
HAS ACTUALLY BEGUN TO PICK UP SOME MOMENTUM TOWARD THE NORTH IN THE
LAST FEW HOURS. BASED ON THE RAP...THIS BOUNDARY WILL BE NEAR I-90
AT 15Z...BY 18Z IT SHOULD BE WORKING ITS WAY THROUGH THE TWIN CITIES
BEFORE BECOMING STATIONARY AT 00Z FROM A SFC LOW OVER NORTH CENTRAL
NEB...NORTHEAST THROUGH ABERDEEN AND UP TOWARD LAKE OF THE WOODS.
FOR THIS FORECAST...FAVORED A NAM/ECMWF BLEND FOR HANDLING OF LARGE
SCALE FEATURES SUCH AS SHORTWAVES AND THE LLJ...WHILE A BLEND OF THE
HI-RES CAMS WERE USED TO TRY AND ADD DETAIL TO THE POP FORECAST.
BASED ON THAT...WHAT FOLLOWS IS THE CURRENT THINKING IS OF 330 AM
FOR WHAT WILL HAPPEN TODAY.
FOR THE WARM FRONT COMING NORTH...IS LOOKING LIKE CONVECTIVE
ACTIVITY WILL BE SCATTERED IN NATURE...AS H85 LLJ IS ACTUALLY
SOMEWHAT DIFFLUENT OVER MN...WITH ONE BRANCH SPLITTING OF FROM IOWA
INTO SODAK...WITH THE REST OF THE JET FANNING OUT TOWARD THE NE
ACROSS MN INTO WI. THE HRRR AND OTHER CAMS ALONG WITH THE RAP IS
SHOWING A BATCH OF ELEVATED SHOWERS AND STORMS DEVELOPING EARLY THIS
MORNING NORTH OF THE BOUNDARY AND HEADING TOWARD SE MN BY THE EARLY
AFTERNOON. THIS SEEMS TO BE IN RESPONSE TO A SHORTWAVE NOTED ON
WATER VAPOR CURRENTLY WEST OF OMAHA THAT THE RAP DRAGS NE TOWARD SE
MN THROUGH THE MORNING. THE HRRR IS BY FAR THE MOST AGGRESSIVE WITH
THIS CONVECTION AT THE MOMENT...BUT OUTSIDE OF SOME POTENTIAL FOR
HAIL...THE SEVERE THREAT LOOKS LIMITED WITH THIS BATCH OF
CONVECTION...IF IT DOES FORM.
FOR THE SEVERE THREAT...ATTENTION REALLY TURNS TO ERN SODAK/WRN MN
THIS AFTERNOON. WITH THE NAM/ECMWF SHOWING THE LLJ ANGLING BACK NW
INTO SODAK IN RESPONSE TO HEIGHT FALLS ALOFT...THIS SHOULD LEAD TO
THE INITIATION OF MORE SURFACE BASED CONVECTION SOMEWHERE NEAR THE
RETREATING WARM FRONT IN ERN SODAK/WRN MN. FORECAST SOUNDINGS FROM
THE RAP/NAM SHOW ATMO REMAINING CAPPED ACROSS WRN MN UNTIL ABOUT
21Z...AT WHICH POINT YOU ARE DEALING WITH AROUND 1500 J/KG OF SBCAPE
IN A WEAKLY CAPPED...STRONGLY SHEARED /ESPECIALLY IN THE LOWEST 3
KM/ ENVIRONMENT. NMM/ARW BASED CAMS SHOW LITTLE CONVECTION
DEVELOPING THROUGH 21Z...BUT QUICKLY GENERATE CONVECTION AFTER
21Z...SO WAITED TO INTRODUCE ANY LIKELY POPS UNTIL 21Z. SEEING TWO
CAMPS IN THE CAMS FOR HOW CONVECTION DEVELOPS THIS AFTERNOON...WITH
THE ARW AND NSSL-WRF GENERATING STORMS OVER WRN MN...WHILE THE NMM
AND SPCWRF GENERATE CONVECTION OVER ERN SODAK. THIS IDEA FOR
ACTIVITY STARTING OUT WEST THIS AFTERNOON IS FURTHER SUPPORTED BY
THE SPC SSEO...WHICH SHOWS NEIGHBORHOOD PROBABILITIES FOR UPDRAFT
HELICITY AND UPDRAFT STRENGTH BEING MAXIMIZED OVER ERN SODAK INTO
WRN MN...WITH VERY LITTLE ACTIVITY BEING NOTED FROM SRN INTO ERN MN
AND WRN WI THIS AFTERNOON. GIVEN DEGREE OF LOW LEVEL SHEAR...THERE
WILL BE THE THREAT FOR TORNADIC ACTIVITY WHILE THE STORMS AREA
DISCRETE...BUT DO EXPECT STORMS THIS AFTERNOON TO GROW
UPSCALE...WITH A HAIL/WIND THREAT CONTINUING INTO THE NIGHT.
FOR TONIGHT...WHAT HAPPENS WITH CONVECTION THIS AFTERNOON WILL PLAY
A LARGE ROLE IN WHAT HAPPENS TONIGHT. WITHIN THE CAMS...WE ARE AGAIN
LOOKING AT TWO CAMPS. THE NMM AND SPCWRF DO NOT BRING THE DAKOTA
CONVECTION INTO MN...WHILE SENDING ANOTHER MCS RACING ACROSS
IOWA...KEEPING MUCH OF THE MPX CWA DRY. THE ARW AND NSSL-WRF CONGEAL
THE AFTERNOON CELLS IN THE WEST INTO A LINE...AND TRACK THAT COMPLEX
OF STORMS EAST ACROSS THE STATE THROUGH THE NIGHT. GIVEN EXPECTED
EVOLUTION OF THE LLJ FROM THE ECMWF/NAM...FAVOR THE ARW/NSSL-WRF
CAMP...WITH A COMPLEX OF STORMS WORKING EAST ACROSS THE AREA THROUGH
THE NIGHT...WITH CONVECTIVE COVERAGE AND INTENSITY SLOWLY
DIMINISHING AFTER 6Z.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 400 AM CDT WED MAY 29 2013
CUTOFF UPPER CIRCULATION DEVELOPS AND LINGERS ACROSS THE HIGH
PLAINS AND WESTERN GREAT LAKES INTO THE COMING WEEKEND. AS THE
UPPER LOW TAKES FORM OVER THE NORTHERN PLAINS THROUGH THURSDAY...
A BELT OF FASTER WESTERLY FLOW ASSOCIATED WITH A SHORT WAVE
TROUGH WILL MOVE EAST FROM THE CENTRAL PLAINS TO THE MIDWEST.
CLOUDS WILL REMAIN ABUNDANT OVER THE REGION...AND WILL LIMIT
SIGNIFICANT DESTABILIZATION. HOWEVER...LARGE SCALE ASCENT FROM
THE INCOMING SHORT WAVE AND STEEPENING MID LEVEL LAPSE WILL LIKELY
SUPPORT SOME STRONG TO SEVERE STORMS ACROSS CENTRAL AND SOUTHERN
MINNESOTA THURSDAY AFTERNOON AND THURSDAY NIGHT. THE SURFACE LOW
WILL DEEPEN AND OCCLUDE IN EASTERN NORTH DAKOTA INTO THURSDAY
NIGHT...AND WILL HELP PUSH THE COLD FRONT EAST INTO CENTRAL
MINNESOTA. WE SHOULD SEE HIGH POPS INTO THURSDAY AFTERNOON AS
THIS SYSTEM MOVES THROUGH...AND MAINLY OVER EASTERN AREAS INTO
THURSDAY NIGHT AHEAD OF COLD FRONT. HAIL AND STRONG WINDS WILL BE
THE MAIN THREATS...ALONG WITH HEAVY RAIN. WILL TRAIL POPS OFF TO
THE WEST DURING THE AFTERNOON. THE 00Z ECMWF IS MOST CONSISTENT
WITH DRIVING A DRY SLOT NORTHEAST OVER THE AREA INTO
FRIDAY...LIMITING SIGNIFICANT CONVECTION FURTHER EAST IN THE
REMNANT WARM SECTOR INTO WESTERN WISCONSIN. THIS WILL LIMIT SEVERE
WEATHER DEVELOPMENT ON FRIDAY...WITH THE DAY 3 OUTLOOK MAINLY
SOUTHEAST OF OUR CWA.
SYSTEM SLOW TO MOVE THROUGH THE AREA...WITH COLD AIR CIRCULATING
OVER THE REGION WELL INTO THE WEEKEND. EXPECTING DRIER CONDITIONS
DEVELOPING SATURDAY NIGHT AND LINGERING INTO MONDAY. TEMPERATURES
WILL RANGE SOME 5 TO 10 DEGREES BELOW AVERAGE THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1050 PM CDT TUE MAY 28 2013
CONDS EXPECTED TO DROP TO IFR ARND MIDNIGHT AND REMAIN THERE THRU
THE EARLY MORNING HOURS. MAY BE SOME BREAKS IN THE OVC IN WRN
MN...ALLOWING CONDS TO JUMP FROM MVFR TO VFR THEN BACK DOWN TO IFR
AS PATCHY FOG AND/OR LOW STRATUS DEVELOPS. HAVE SEEN WRN MN BREAK
OUT INTO CLR SKIES...BUT HIGH CONVECTIVE DEBRIS CLOUDS STARTING TO
MOVE IN FROM THE S AND W WHICH COULD PLAY HAVOC WITH THE
CIGS...ESP FOR WRN SITES INCLUDING KRWF-KAXN-KSTC. SITES OUTSIDE
OF KMSP ARE LIKELY TO SEE VSBYS DROP TO ARND 1SM...IF NOT
LOWER...ESPECIALLY IN SPOTS WHERE HIGH CLOUDS DO NOT MOVE IN AND
IN THE FAVORED FOG SITES...INCLUDING KRNH-KEAU. CONDS GRADUALLY
IMPROVE AFTER DAYBREAK AND A FEW HOURS OF VFR CONDS ARE EXPECTED.
CONVECTION THEN DEVELOPS LATE TMRW AFTN INTO TMRW EVE AS A WMFNT
LIFTS N THROUGH THE REGION. PREVAILING THINKING IS THAT INITIAL
ONSET OF PRECIP WOULD BE TSTMS THEN WOULD BE FOLLOWED BY -RA. HAVE
PLAYED THE TSRA AS TEMPO GROUPS ATTM...WITH ONLY DEGRADING CONDS
DOWN TO MVFR DUE TO UNCERTAINTY BUT HVY RAIN COULD EASILY DROP
VSBYS TO LESS THAN 3SM. WINDS TO REMAIN LGT/VRBL THRU MUCH OF THE
OVERNIGHT HOURS THEN PICK UP FROM THE SE TMRW... INCLUDING BECOMING
GUSTY IN THE AFTN THRU THE EARLY EVE.
KMSP...STARTED OUT WITH CONDS IN MINIMAL MVFR RANGE. ALTHOUGH
SATELLITE TRENDS INDICATE A CLEARING-OUT AREA OVER WRN MN...NOT
TOO SURE THIS WILL MAKE IT TO KMSP BEFORE HIGH CONVECTIVE DEBRIS
MOVES IN ATOP THE LOW CEILINGS...NOT ALLOWING A VFR PERIOD IN THE
EARLY MRNG HOURS. AS WINDS SETTLE DOWN...A COMBINATION OF FOG AND
LOW STRATUS WILL DEGRADE VSBYS INTO MVFR RANGE. AM NOT LOOKING
FOR VSBY LESS THAN 3SM BUT IT CANNOT BE RULED OUT ENTIRELY. AFTER
DAYBREAK...LOW STRATUS ERODES AND A PERIOD OF VFR IS EXPECTED.
MIDLVL CEILINGS DEVELOP BY MID- AFTN AHEAD OF A WMFNT EXPECTED TO
LIFT N. WITH THIS FNT...SCATTERED CONVECTION WILL DEVELOP. UNCLEAR
AS TO IF IT WILL DIRECTLY MOVE OVER MSP SO HAVE RAN WITH A TEMPO
GROUP IN THE LATE AFTN TO EARLY EVE FOR CB/TS FOR ONLY MVFR CONDS.
THAT SAID...IFR OR LOWER CONDS ARE CERTAINLY POSSIBLE. MORE STEADY
RAIN IS THEN EXPECTED BEHIND THE INITIAL TSTMS WITH UPPER-RANGE
MVFR CONDS...ALTHOUGH A PERIOD OF OCNL TSRA AFTER 00Z LOOKS TO
OCCUR.
/OUTLOOK FOR KMSP/
THU...MVFR OR LOWER CIGS LIKELY. SHRA/TSRA LIKELY. WINDS S 15-20
KTS.
FRI...MVFR OR LOWER CIGS LIKELY. SHRA/TSRA LIKELY. WINDS SW 10-15
KTS.
SAT...MVFR CIGS POSSIBLE. CHANCE SHRA/TSRA. WINDS WNW 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...DWE
AVIATION...JPC
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1003 PM CDT Thu May 30 2013
.UPDATE...
Issued at 1000 PM CDT THU MAY 30 2013
Adjusted short term forecast for current radar/satellite/model
trends. Except for a few isolated cells over far nw MO and east
central KS looking quiet for a few more hours. However, already
seeing signs on satellite/radar over central KS. The rapid increase
of alto-cumulus clouds and elevated returns is signaling the rapid
redevelopment of the low level jet. The 00z NAM is noticeably
stronger with the h8 winds and this seems reasonable. The 00z NAM,
HRRR and RAP all generate rapid convective development on the nose of
the low level jet and spread it across east central KS and west
central MO during the pre-dawn hours. Heavy rains and near-severe
storms are expected between 08z-14z Friday over this region.
&&
.SHORT TERM...(This Evening through Friday)
Issued at 325 PM CDT THU MAY 30 2013
Leading edge of storms should move east of the forecast area by 4 or
so leaving just the trailing stratiform area of rainfall with
embedded convection through the early evening. So through this
evening the chances of rain/embedded storms will diminish from west
to east. The focus then shifts to tonight for the possibility of
convection erupting in eastern Kansas and then spreading into
western Missouri. There is a quite a bit of uncertainty with how
things may evolve tonight as several short-range models keep things
quiet overnight. However, the more reliable HRRR, which has been
handling today`s convection very well, has been consistent in
developing convection somewhere across northeastern Kansas and
moving into west central and northwestern Missouri. This roughly
corresponds to an area of strong isentropic lift with a focusing of
the LLJ depicted by the GFS. There should be enough instability and
shear to lead to storm organization so a few severe storms are
possible with large hail the biggest threat with damaging winds
possible as well. Will keep the flash flood watch going as is given
recent heavy rains across northern Missouri and persistent moderate
to heavy rain across the southern portions of the forecast and the
uncertainty with where any heavy rain may set up tonight. Some areas
within the watch area have good chance of seeing heavy rainfall
tonight and some much river flooding ongoing and already saturated
soils, it won`t take much more rain to lead to rapid runoff and
flash flooding.
.LONG TERM...(Friday Night through Thursday)
Issued at 325 PM CDT THU MAY 30 2013
Cold front will slide through the forecast area Friday night,
pushing the threat for thunderstorms southeast of the area.
Elongated area of high pressure will build into much of the Plains
over the weekend providing dry conditions and comfortable
temperatures. Cold air advection on Saturday and Sunday will keep
highs in the upper 60 and lower 70s.
Warm air advection on the back side of this area of high pressure
will set the stage for an increase in rain chances next week.
Initial rain chances will begin early Tuesday when a weak shortwave
will eject into the Plains ahead of a deeper wave digging into the
Upper Midwest. This system will eventually drop a cold front and
associated chances for showers and thunderstorms into the area by
mid-week, though there are still considerable model differences with
the timing of this activity.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday Evening)
Issued at 639 PM CDT THU MAY 30 2013
North-south line of scattered convection over north central/central
KS tracking ENE is being handled best by the HRRR (short- range
convective model). Activity is tied to a shortwave and will likely
survive past sunset, although in a slightly weakened state. AWIPS
tracking tool is in line with HRRR and places activity into the KSTJ
and KMCI terminals between 02z-03z. Convection could hang around for
another hour or two thereafter.
Better chances for more organized and stronger convection appears it
will be tied to the re-development of the low-level jet. Several
short-range convective models including the HRRR, local WRF and NAM
develop an MCS into east central KS/west central MO during the pre-
dawn hours of Friday morning. For the most part expect VFR ceilings
with brief periods of MVFR possible. Should see activity clear out
mid/late morning.
With another shortwave moving into northeast KS/northwest MO and a
hint of a weak front over northwest MO can see signs for scattered
late afternoon convection to form along the weak front during the
late afternoon hours. If this activity forms it will likely be fairly
intense.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...FLASH FLOOD WATCH through Friday evening FOR KSZ025-057-060-
102>105.
MO...FLASH FLOOD WATCH through Friday evening FOR MOZ001>008-011>017-
020>025-028>033-037>040-043>046-053-054.
&&
$$
UPDATE...MJ
SHORT TERM...CDB
LONG TERM...Hawblitzel
AVIATION...MJ
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
846 PM CDT THU MAY 30 2013
.UPDATE...
ISSUED AT 840 PM CDT THU MAY 30 2013
CONVECTIVE TRENDS ARE PROCEEDING ABOUT AS ANTICIPATED THIS
EVENING. WHILE MUCH OF THE SHORT TERM UPDATING WILL BE REACTIVE
FOR THE REST OF THE NIGHT...GENERALLY SPEAKING I EXPECT THE LINE
OF STORMS NOW MOVING THROUGH SOUTHWEST/SOUTH CENTRAL MISSOURI TO
CONTINUE MOVING STEADILY EAST FOR THE REST OF THE EVENING INTO THE
OVERNIGHT HOURS. THE RAP CONTINUES TO SHOW A VERY STRONG LOW LEVEL
JET WITH TREMENDOUS MOISTURE CONVERGENCE OVER THE AREA FOR MUCH OF
THE REST OF THE NIGHT...AND THE HRRR SLOWS THE LINE FURTHER OVER
SOUTHERN AND EASTERN SECTIONS OF THE CWFA. IT ALSO DEVELOPS THE
CONVECTION NOW PERCOLATING OVER CENTRAL AND EASTERN KANSAS INTO
ANOTHER HEAVY RAIN PRODUCING MCS BEFORE BY 10Z AND IT MOVES EAST INTO
OUR AREA BY AROUND 12Z. DUE TO THE POTENTIAL FOR ADDITIONAL HEAVY
RAIN TONIGHT AND TOMORROW MORNING...AM GOING TO EXPAND THE FLASH
FLOOD WATCH TO THE REMAINDER OF THE AREA STARTING IMMEDIATELY AND
CONTINUING TO 12Z SATURDAY.
CARNEY
&&
.SHORT TERM...(THROUGH LATE TONIGHT)
ISSUED AT 240 PM CDT THU MAY 30 2013
TORNADO WATCH CONTINUES UNTIL 8 PM. ATMOSPHERE OUTSIDE OF OUTFLOW
COOLED AIR HAS BECOME QUITE UNSTABLE WITH MLCAPES ABOVE 2000 J/KG.
AT THE SAME TIME...DEEP LAYER SHEAR IS INCREASING IN RESPONSE TO
APPROACHING TROUGH CURRENTLY OVER THE CENTRAL PLAINS. THIS TROUGH
IS THE MAIN FOCUS FOR LARGE SCALE ASCENT TONIGHT AND CONSEQUENTLY IT
WILL DETERMINE THE OVERALL PRECIPITATION TRENDS. RAP SHOWS THIS
TROUGH MOVING ACROSS THE CWA AROUND 06Z...SO CURRENT THINKING IS
THAT LINE OF STORMS OVER WESTERN MO WILL CONTINUE TO SLOWLY MOVE
EAST ACROSS THE AREA LATER THIS AFTERNOON AND EVENING.
AFOREMENTIONED INSTABILITY AND SHEAR STILL FAVORS THE POTENTIAL FOR
A FEW SUPERCELLS OR ORGANIZED MULTI-CELLS THAT COULD PRODUCE LARGE
HAIL AND DAMAGING WINDS. LOW LEVEL SHEAR ALSO SUGGESTS THAT ONE OR
TWO TORNADOES COULD FORM IN THE STRONGER STORMS. STILL LOOKS
REASONABLE THAT WESTERN MO LINE WILL EXIT THE EASTERN COUNTIES LATER
THIS EVENING. OUTFLOW FROM THE LINE WILL LIKELY STALL OVER SOUTHERN
MO...SO KEPT CHANCE OF THUNDERSTORMS GOING IN THE SOUTHERN CWA INTO
THE OVERNIGHT HOURS. STILL EXPECT REDEVELOPMENT OF THUNDERSTORMS
OVER WESTERN MO ON THE NOSE OF THE LOW LEVEL JET OVERNIGHT THAT WILL
MOVE INTO NORTHEAST AND CENTRAL MO TOWARD 12Z.
FLASH FLOOD WATCH WILL CONTINUE AS IS. HEAVIEST RAINFALL WILL FOCUS
OVER THE WATCH AREA TONIGHT AND THE SOUTHERN AND EASTERN COUNTIES
HAVE HIGH FLASH FLOOD GUIDANCE. ATMOSPHERE IS VERY MOIST AND DEEP
LAYER FLOW FAVORS TRAINING TONIGHT.
.LONG TERM...(FRIDAY THROUGH NEXT THURSDAY)
ISSUED AT 240 PM CDT THU MAY 30 2013
CONVECTIVE TRENDS ARE SOMEWHAT UNCLEAR FOR FRIDAY MORNING. SOME
GUIDANCE SHOWS LINGERING CONVECTION ACROSS THE EASTERN OZARKS AND
SOUTHERN ILLINOIS. THIS COULD BE POSSIBLE IF THE AFOREMENTIONED OUTFLOW
BOUNDARY FROM THURSDAY NIGHT`S CONVECTION IS STILL IN PLACE OVER
THOSE AREAS. HOWEVER...MOST OF THE GUIDANCE SHOWS A DRYING TREND
BY AROUND 12Z ACROSS THE AREA. THEN...THE LOW LEVEL JET REFOCUSES
BACK OVER NORTHERN/NORTHWESTERN MISSOURI. ALL GUIDANCE SHOWS A
TREMENDOUS AMOUNT OF MOISTURE CONVERGENCE IN THAT AREA STARTING
ABOUT 12Z AND RAIN DEVELOPING BETWEEN 12Z AND 15Z...SPREADING INTO
NORTHEAST MISSOURI/WEST CENTRAL ILLINOIS PROBABLY DURING THE MID
TO LATE MORNING. INSTABILITY WILL BUILD RAPIDLY DURING THE LATE
MORNING WITH MUCAPE EXCEEDING 2500 J/KG ACCORDING TO MOST GUIDANCE
AND DEEP LAYER SHEAR AROUND 50-60KTS SO SEVERE STORMS WILL BE
POSSIBLE AT ANY TIME DURING THE LATE MORNING. HOWEVER...THE MAIN
SHOW WILL LIKELY DEVELOP DURING THE LATE AFTERNOON OR EARLY
EVENING AS ANOTHER LOBE OF VORTICITY WRAPS AROUND THE SOUTH SIDE
OF THE UPPER LEVEL LOW AND PUSHES THE SURFACE FRONT INTO NORTHWEST
MISSOURI. WHATEVER`S LEFT OF THE CAP WILL ALSO BE WIPED AWAY.
AFTERNOON CAPE VALUES LOOK TO BE IN EXCESS OF 3000 J/KG WITH SHEAR
STAYING ABOVE 50KTS. THINK THERE WILL BE SOME DISCRETE STORMS
INITIALLY...BUT WITH LITTLE OR NO CAP AND COPIOUS CAPE WE SHOULD
SEE THE STORMS CONGEAL INTO A LINE. CANNOT RULE OUT ANY KIND OF
SEVERE WEATHER INCLUDING DAMAGING WINDS...LARGE HAIL...AND EVEN
TORNADOES WITH THE LINE. THE LINE SHOULD PROGRESS AT A MODERATE
PACE INTO SOUTHEAST MISSOURI BY EARLY MORNING SATURDAY. OF COURSE
WITH THE HEAVY RAIN POTENTIAL AND NEARLY SATURATED GROUND THERE
WILL BE A CONTINUING FLASH FLOOD THREAT...AND IT`S LIKELY THE
FLASH FLOOD WATCH WILL NEED TO BE EXPANDED EITHER EARLY FRIDAY
MORNING OR FRIDAY AFTERNOON TO COVER THE REST OF THE CWFA.
CURRENT THINKING IS THAT THE INITIAL LINE OF CONVECTION WILL WEAKEN
OVER THE EASTERN OZARKS SATURDAY MORNING. HOWEVER THERE WILL BE
REDEVELOPMENT BY EARLY SATURDAY AFTERNOON...PERHAPS AS FAR NORTHWEST
AS THE COLUMBIA AREA...AS THE SURFACE COLD FRONT FINALLY KICKS INTO
GEAR AND HEADS EAST. SPC STILL HAS THE SOUTHEASTERN 2/3 OF THE CWFA
IN A SLIGHT RISK SATURDAY...INCLUDING THE STL METRO AREA AND POINTS
ALONG AND EAST OF THE I-44/I-55 CORRIDORS. THE UPPER LEVEL
SHORTWAVE FINALLY SWINGS THROUGH SATURDAY AFTERNOON/EARLY EVENING
PUSHING THE COLD FRONT SOUTHEAST INTO THE LOWER
MISSISSIPPI/TENNESSEE VALLEYS.
(SUNDAY THROUGH NEXT THURSDAY)
HIGH PRESSURE IS STILL EXPECTED TO BUILD ACROSS THE MIDWEST SUNDAY
AND CONTROL THE WEATHER AT LEAST THROUGH MONDAY. EXPECTING BELOW
NORMAL TEMPERATURES AND LESS HUMID CONDITIONS THROUGH THAT PERIOD.
MEDIUM RANGE GUIDANCE IS A LITTLE FASTER THAN YESTERDAY IN PUSHING
THE HIGH EAST AWAY FROM THE MID-MISSISSIPPI VALLEY. SOUTHERLY FLOW
RETURNS TUESDAY AND BOTH THE GFS AND ECMWF PRINT OUT PRECIP LATE
TUESDAY THROUGH THURSDAY AS A SHORTWAVE DIPS INTO THE NORTHERN
PLAINS. THE GFS IS MUCH MORE DYNAMIC WITH THIS WAVE THAN THE ECMWF
AND THEREFORE CRANKS OUT A LOT MORE PRECIP. HAVE OPTED TO JUST
STICK WITH CHANCE POPS FOR THIS PERIOD RIGHT NOW. WILL CONTINUE TO
WATCH THIS NEXT WAVE AND INCREASE POPS AS NEEDED IF BOTH MODELS
CONTINUE TO TREND WETTER.
CARNEY
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 644 PM CDT THU MAY 30 2013
LINE OF THUNDERSTORMS EXTENDING FROM NORTHEAST TO SOUTHWEST ACROSS
THE AREA WILL CONTINUE TO MOVE EAST THIS EVENING. MOST OF THE
LIGHTNING WITH THESE STORMS WILL BE ON THE LEADING EDGE...THOUGH
RAIN WITH SOME LIGHTING MAY LAST AT ANY ONE AIRPORT FOR UP TO 4
HOURS. CONDITIONS ARE MAINLY VFR EXCEPT IN THE HEAVIER CORES WHERE
THEY MAY TEMPORARILY DROP TO IFR. THE STRONGEST STORMS HAVE NOW
MOVED INTO SOUTHWEST ILLINOIS WHERE SOME STRONG GUSTS AND HAIL CAN
BE EXPECT TO THE EAST OF THE ST. LOUIS METRO TAF SITES. EXPECT
THIS LINE TO CONTINUE TO MOVE SOUTHEAST. THUNDERSTORMS MAY PERSIST
OVER PARTS OF SOUTHERN MISSOURI LATE THIS EVENING AND OVERNIGHT.
STILL EXPECT ADDITIONAL THUNDERSTORMS TO DEVELOP OVER WESTERN MO
LATE TONIGHT THAT WILL MOVE INTO CENTRAL AND NORTHEAST MISSOURI ON
FRIDAY MORNING. THESE STORMS WILL MOVE SLOWLY SOUTHEAST ACROSS THE
AREA DURING THE AFTERNOON AND EVENING HOURS THAT WILL AFFECT KCOU
AND THE ST. LOUIS METRO TAF SITES WITH STRONG WIND GUSTS AND HAIL.
SPECIFICS FOR KSTL...THUNDERSTORMS WITH A RECENT REPORT OF WIND
GUSTS TO 50 MPH WILL PASS NEAR THE AIRPORT WITHIN THE NEXT HALF
HOUR. THIS STORM IS AHEAD OF THE MAIN AREA OF SHOWERS AND
THUNDERSTORMS THAT WILL MOVE ACROSS THE TERMINAL THROUGH MIDNIGHT.
THEN EXPECT MAINLY DRY AND VFR CONDITIONS UNTIL A LINE OF STORMS
MOVES INTO THE REGION FROM THE NORTHWEST LATE FRIDAY AFTERNOON AND
EVENING.
BRITT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR AUDRAIN MO-BOONE
MO-CALLAWAY MO-COLE MO-CRAWFORD MO-FRANKLIN MO-GASCONADE MO-
IRON MO-JEFFERSON MO-KNOX MO-LEWIS MO-LINCOLN MO-MADISON MO-
MARION MO-MONITEAU MO-MONROE MO-MONTGOMERY MO-OSAGE MO-PIKE
MO-RALLS MO-REYNOLDS MO-SHELBY MO-ST. CHARLES MO-ST.
FRANCOIS MO-ST. LOUIS CITY MO-ST. LOUIS MO-STE. GENEVIEVE
MO-WARREN MO-WASHINGTON MO.
IL...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR ADAMS IL-BOND IL-
BROWN IL-CALHOUN IL-CLINTON IL-FAYETTE IL-GREENE IL-JERSEY
IL-MACOUPIN IL-MADISON IL-MARION IL-MONROE IL-MONTGOMERY IL-
PIKE IL-RANDOLPH IL-ST. CLAIR IL-WASHINGTON IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
649 PM CDT THU MAY 30 2013
.SHORT TERM...(THROUGH LATE TONIGHT)
ISSUED AT 240 PM CDT THU MAY 30 2013
TORNADO WATCH CONTINUES UNTIL 8 PM. ATMOSPHERE OUTSIDE OF OUTFLOW
COOLED AIR HAS BECOME QUITE UNSTABLE WITH MLCAPES ABOVE 2000 J/KG.
AT THE SAME TIME...DEEP LAYER SHEAR IS INCREASING IN RESPONSE TO
APPROACHING TROUGH CURRENTLY OVER THE CENTRAL PLAINS. THIS TROUGH
IS THE MAIN FOCUS FOR LARGE SCALE ASCENT TONIGHT AND CONSEQUENTLY IT
WILL DETERMINE THE OVERALL PRECIPITATION TRENDS. RAP SHOWS THIS
TROUGH MOVING ACROSS THE CWA AROUND 06Z...SO CURRENT THINKING IS
THAT LINE OF STORMS OVER WESTERN MO WILL CONTINUE TO SLOWLY MOVE
EAST ACROSS THE AREA LATER THIS AFTERNOON AND EVENING.
AFOREMENTIONED INSTABILITY AND SHEAR STILL FAVORS THE POTENTIAL FOR
A FEW SUPERCELLS OR ORGANIZED MULTI-CELLS THAT COULD PRODUCE LARGE
HAIL AND DAMAGING WINDS. LOW LEVEL SHEAR ALSO SUGGESTS THAT ONE OR
TWO TORNADOES COULD FORM IN THE STRONGER STORMS. STILL LOOKS
REASONABLE THAT WESTERN MO LINE WILL EXIT THE EASTERN COUNTIES LATER
THIS EVENING. OUTFLOW FROM THE LINE WILL LIKELY STALL OVER SOUTHERN
MO...SO KEPT CHANCE OF THUNDERSTORMS GOING IN THE SOUTHERN CWA INTO
THE OVERNIGHT HOURS. STILL EXPECT REDEVELOPMENT OF THUNDERSTORMS
OVER WESTERN MO ON THE NOSE OF THE LOW LEVEL JET OVERNIGHT THAT WILL
MOVE INTO NORTHEAST AND CENTRAL MO TOWARD 12Z.
FLASH FLOOD WATCH WILL CONTINUE AS IS. HEAVIEST RAINFALL WILL FOCUS
OVER THE WATCH AREA TONIGHT AND THE SOUTHERN AND EASTERN COUNTIES
HAVE HIGH FLASH FLOOD GUIDANCE. ATMOSPHERE IS VERY MOIST AND DEEP
LAYER FLOW FAVORS TRAINING TONIGHT.
.LONG TERM...(FRIDAY THROUGH NEXT THURSDAY)
ISSUED AT 240 PM CDT THU MAY 30 2013
CONVECTIVE TRENDS ARE SOMEWHAT UNCLEAR FOR FRIDAY MORNING. SOME
GUIDANCE SHOWS LINGERING CONVECTION ACROSS THE EASTERN OZARKS AND
SOUTHERN ILLINOIS. THIS COULD BE POSSIBLE IF THE AFOREMENTIONED OUTFLOW
BOUNDARY FROM THURSDAY NIGHT`S CONVECTION IS STILL IN PLACE OVER
THOSE AREAS. HOWEVER...MOST OF THE GUIDANCE SHOWS A DRYING TREND
BY AROUND 12Z ACROSS THE AREA. THEN...THE LOW LEVEL JET REFOCUSES
BACK OVER NORTHERN/NORTHWESTERN MISSOURI. ALL GUIDANCE SHOWS A
TREMENDOUS AMOUNT OF MOISTURE CONVERGENCE IN THAT AREA STARTING
ABOUT 12Z AND RAIN DEVELOPING BETWEEN 12Z AND 15Z...SPREADING INTO
NORTHEAST MISSOURI/WEST CENTRAL ILLINOIS PROBABLY DURING THE MID
TO LATE MORNING. INSTABILITY WILL BUILD RAPIDLY DURING THE LATE
MORNING WITH MUCAPE EXCEEDING 2500 J/KG ACCORDING TO MOST GUIDANCE
AND DEEP LAYER SHEAR AROUND 50-60KTS SO SEVERE STORMS WILL BE
POSSIBLE AT ANY TIME DURING THE LATE MORNING. HOWEVER...THE MAIN
SHOW WILL LIKELY DEVELOP DURING THE LATE AFTERNOON OR EARLY
EVENING AS ANOTHER LOBE OF VORTICITY WRAPS AROUND THE SOUTH SIDE
OF THE UPPER LEVEL LOW AND PUSHES THE SURFACE FRONT INTO NORTHWEST
MISSOURI. WHATEVER`S LEFT OF THE CAP WILL ALSO BE WIPED AWAY.
AFTERNOON CAPE VALUES LOOK TO BE IN EXCESS OF 3000 J/KG WITH SHEAR
STAYING ABOVE 50KTS. THINK THERE WILL BE SOME DISCRETE STORMS
INITIALLY...BUT WITH LITTLE OR NO CAP AND COPIOUS CAPE WE SHOULD
SEE THE STORMS CONGEAL INTO A LINE. CANNOT RULE OUT ANY KIND OF
SEVERE WEATHER INCLUDING DAMAGING WINDS...LARGE HAIL...AND EVEN
TORNADOES WITH THE LINE. THE LINE SHOULD PROGRESS AT A MODERATE
PACE INTO SOUTHEAST MISSOURI BY EARLY MORNING SATURDAY. OF COURSE
WITH THE HEAVY RAIN POTENTIAL AND NEARLY SATURATED GROUND THERE
WILL BE A CONTINUING FLASH FLOOD THREAT...AND IT`S LIKELY THE
FLASH FLOOD WATCH WILL NEED TO BE EXPANDED EITHER EARLY FRIDAY
MORNING OR FRIDAY AFTERNOON TO COVER THE REST OF THE CWFA.
CURRENT THINKING IS THAT THE INITIAL LINE OF CONVECTION WILL WEAKEN
OVER THE EASTERN OZARKS SATURDAY MORNING. HOWEVER THERE WILL BE
REDEVELOPMENT BY EARLY SATURDAY AFTERNOON...PERHAPS AS FAR NORTHWEST
AS THE COLUMBIA AREA...AS THE SURFACE COLD FRONT FINALLY KICKS INTO
GEAR AND HEADS EAST. SPC STILL HAS THE SOUTHEASTERN 2/3 OF THE CWFA
IN A SLIGHT RISK SATURDAY...INCLUDING THE STL METRO AREA AND POINTS
ALONG AND EAST OF THE I-44/I-55 CORRIDORS. THE UPPER LEVEL
SHORTWAVE FINALLY SWINGS THROUGH SATURDAY AFTERNOON/EARLY EVENING
PUSHING THE COLD FRONT SOUTHEAST INTO THE LOWER
MISSISSIPPI/TENNESSEE VALLEYS.
(SUNDAY THROUGH NEXT THURSDAY)
HIGH PRESSURE IS STILL EXPECTED TO BUILD ACROSS THE MIDWEST SUNDAY
AND CONTROL THE WEATHER AT LEAST THROUGH MONDAY. EXPECTING BELOW
NORMAL TEMPERATURES AND LESS HUMID CONDITIONS THROUGH THAT PERIOD.
MEDIUM RANGE GUIDANCE IS A LITTLE FASTER THAN YESTERDAY IN PUSHING
THE HIGH EAST AWAY FROM THE MID-MISSISSIPPI VALLEY. SOUTHERLY FLOW
RETURNS TUESDAY AND BOTH THE GFS AND ECMWF PRINT OUT PRECIP LATE
TUESDAY THROUGH THURSDAY AS A SHORTWAVE DIPS INTO THE NORTHERN
PLAINS. THE GFS IS MUCH MORE DYNAMIC WITH THIS WAVE THAN THE ECMWF
AND THEREFORE CRANKS OUT A LOT MORE PRECIP. HAVE OPTED TO JUST
STICK WITH CHANCE POPS FOR THIS PERIOD RIGHT NOW. WILL CONTINUE TO
WATCH THIS NEXT WAVE AND INCREASE POPS AS NEEDED IF BOTH MODELS
CONTINUE TO TREND WETTER.
CARNEY
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 644 PM CDT THU MAY 30 2013
LINE OF THUNDERSTORMS EXTENDING FROM NORTHEAST TO SOUTHWEST ACROSS
THE AREA WILL CONTINUE TO MOVE EAST THIS EVENING. MOST OF THE
LIGHTNING WITH THESE STORMS WILL BE ON THE LEADING EDGE...THOUGH
RAIN WITH SOME LIGHTING MAY LAST AT ANY ONE AIRPORT FOR UP TO 4
HOURS. CONDITIONS ARE MAINLY VFR EXCEPT IN THE HEAVIER CORES WHERE
THEY MAY TEMPORARILY DROP TO IFR. THE STRONGEST STORMS HAVE NOW
MOVED INTO SOUTHWEST ILLINOIS WHERE SOME STRONG GUSTS AND HAIL CAN
BE EXPECT TO THE EAST OF THE ST. LOUIS METRO TAF SITES. EXPECT
THIS LINE TO CONTINUE TO MOVE SOUTHEAST. THUNDERSTORMS MAY PERSIST
OVER PARTS OF SOUTHERN MISSOURI LATE THIS EVENING AND OVERNIGHT.
STILL EXPECT ADDITIONAL THUNDERSTORMS TO DEVELOP OVER WESTERN MO
LATE TONIGHT THAT WILL MOVE INTO CENTRAL AND NORTHEAST MISSOURI ON
FRIDAY MORNING. THESE STORMS WILL MOVE SLOWLY SOUTHEAST ACROSS THE
AREA DURING THE AFTERNOON AND EVENING HOURS THAT WILL AFFECT KCOU
AND THE ST. LOUIS METRO TAF SITES WITH STRONG WIND GUSTS AND HAIL.
SPECIFICS FOR KSTL...THUNDERSTORMS WITH A RECENT REPORT OF WIND
GUSTS TO 50 MPH WILL PASS NEAR THE AIRPORT WITHIN THE NEXT HALF
HOUR. THIS STORM IS AHEAD OF THE MAIN AREA OF SHOWERS AND
THUNDERSTORMS THAT WILL MOVE ACROSS THE TERMINAL THROUGH MIDNIGHT.
THEN EXPECT MAINLY DRY AND VFR CONDITIONS UNTIL A LINE OF STORMS
MOVES INTO THE REGION FROM THE NORTHWEST LATE FRIDAY AFTERNOON AND
EVENING.
BRITT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR AUDRAIN MO-BOONE
MO-CALLAWAY MO-COLE MO-FRANKLIN MO-GASCONADE MO-JEFFERSON
MO-KNOX MO-LEWIS MO-LINCOLN MO-MARION MO-MONITEAU MO-MONROE
MO-MONTGOMERY MO-OSAGE MO-PIKE MO-RALLS MO-SHELBY MO-ST.
CHARLES MO-ST. LOUIS CITY MO-ST. LOUIS MO-WARREN MO.
IL...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR ADAMS IL-BROWN IL-
CALHOUN IL-GREENE IL-JERSEY IL-MACOUPIN IL-MADISON IL-
MONROE IL-PIKE IL-ST. CLAIR IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
640 PM CDT THU MAY 30 2013
.HYDROLOGY...
ISSUED AT 640 PM CDT THU MAY 30 2013
RIVER FORECASTS ISSUED AROUND MIDDAY TODAY FOR THE
MISSISSIPPI...MISSOURI...AND ILLINOIS RIVERS ARE BASED ON 24 HOURS
OF FORECAST RAINFALL. THIS DOES NOT INCLUDE ANY OF THE SIGNIFICANT
RAINFALL EXPECTED AFTER 7 AM FRIDAY. CONTINGENCY FORECASTS ON THE
MISSISSIPPI RIVER INCLUDING FORECAST RAINFALL THROUGH SATURDAY
INDICATE CRESTS NEXT WEEK CLOSE TO APRIL CRESTS AT CLARKSVILLE AND
GAGES UPSTREAM...AND A LITTLE HIGHER AT WINFIELD.
STAGES AT ST. LOUIS AND CHESTER WILL BE APPROACHING 2008
LEVELS...EXCEEDING LAST MONTH`S LEVELS THANKS TO A HIGHER MISSOURI
RIVER FOR THIS EVENT. FRIDAY MORNING FORECASTS WILL INCLUDE
FORECAST RAIN THROUGH SATURDAY MORNING...WHICH ENCOMPASSES MOST OF
THIS EVENT. THESE SHOULD INCREASE FORECAST CRESTS ON BOTH RIVERS.
MEANWHILE...RAINFALL RATES ALONG THE MAIN LINE OF THUNDERSTORMS
THROUGH WEST CENTRAL ILLINOIS INTO NORTHEASTERN MISSOURI HAVE BEEN
DECREASING. RAINFALL AMOUNTS FROM AUTOMATED RAIN GAGES ALONG THIS
LINE HAVE RECORDED UP TO AN 1.6 INCHES OF RAIN AT HANNIBAL
MISSOURI...WHERE A TRAILER PARK NEAR BEAR CREEK WAS REPORTED TO BE
FLOODING. THERE WAS ALSO A REPORT OF 1.87 INCHES AT ASHLAND
MISSOURI. WHILE THIS BAND OF THUNDERSTORMS APPEARS TO BE
DECREASING...THE NEXT AREA OF SIGNIFICANT THUNDERSTORMS CAN BE
EXPECTED TO DEVELOP ACROSS WEST CENTRAL MISSOURI BY LATE FRIDAY
MORNING.
FUCHS
.SHORT TERM...(THROUGH LATE TONIGHT)
ISSUED AT 240 PM CDT THU MAY 30 2013
TORNADO WATCH CONTINUES UNTIL 8 PM. ATMOSPHERE OUTSIDE OF OUTFLOW
COOLED AIR HAS BECOME QUITE UNSTABLE WITH MLCAPES ABOVE 2000 J/KG.
AT THE SAME TIME...DEEP LAYER SHEAR IS INCREASING IN RESPONSE TO
APPROACHING TROUGH CURRENTLY OVER THE CENTRAL PLAINS. THIS TROUGH
IS THE MAIN FOCUS FOR LARGE SCALE ASCENT TONIGHT AND CONSEQUENTLY IT
WILL DETERMINE THE OVERALL PRECIPITATION TRENDS. RAP SHOWS THIS
TROUGH MOVING ACROSS THE CWA AROUND 06Z...SO CURRENT THINKING IS
THAT LINE OF STORMS OVER WESTERN MO WILL CONTINUE TO SLOWLY MOVE
EAST ACROSS THE AREA LATER THIS AFTERNOON AND EVENING.
AFOREMENTIONED INSTABILITY AND SHEAR STILL FAVORS THE POTENTIAL FOR
A FEW SUPERCELLS OR ORGANIZED MULTI-CELLS THAT COULD PRODUCE LARGE
HAIL AND DAMAGING WINDS. LOW LEVEL SHEAR ALSO SUGGESTS THAT ONE OR
TWO TORNADOES COULD FORM IN THE STRONGER STORMS. STILL LOOKS
REASONABLE THAT WESTERN MO LINE WILL EXIT THE EASTERN COUNTIES LATER
THIS EVENING. OUTFLOW FROM THE LINE WILL LIKELY STALL OVER SOUTHERN
MO...SO KEPT CHANCE OF THUNDERSTORMS GOING IN THE SOUTHERN CWA INTO
THE OVERNIGHT HOURS. STILL EXPECT REDEVELOPMENT OF THUNDERSTORMS
OVER WESTERN MO ON THE NOSE OF THE LOW LEVEL JET OVERNIGHT THAT WILL
MOVE INTO NORTHEAST AND CENTRAL MO TOWARD 12Z.
FLASH FLOOD WATCH WILL CONTINUE AS IS. HEAVIEST RAINFALL WILL FOCUS
OVER THE WATCH AREA TONIGHT AND THE SOUTHERN AND EASTERN COUNTIES
HAVE HIGH FLASH FLOOD GUIDANCE. ATMOSPHERE IS VERY MOIST AND DEEP
LAYER FLOW FAVORS TRAINING TONIGHT.
.LONG TERM...(FRIDAY THROUGH NEXT THURSDAY)
ISSUED AT 240 PM CDT THU MAY 30 2013
CONVECTIVE TRENDS ARE SOMEWHAT UNCLEAR FOR FRIDAY MORNING. SOME
GUIDANCE SHOWS LINGERING CONVECTION ACROSS THE EASTERN OZARKS AND
SOUTHERN ILLINOIS. THIS COULD BE POSSIBLE IF THE AFOREMENTIONED
OUTFLOW BOUNDARY FROM THURSDAY NIGHT`S CONVECTION IS STILL IN PLACE
OVER THOSE AREAS. HOWEVER...MOST OF THE GUIDANCE SHOWS A DRYING TREND
BY AROUND 12Z ACROSS THE AREA. THEN...THE LOW LEVEL JET REFOCUSES
BACK OVER NORTHERN/NORTHWESTERN MISSOURI. ALL GUIDANCE SHOWS A
TREMENDOUS AMOUNT OF MOISTURE CONVERGENCE IN THAT AREA STARTING
ABOUT 12Z AND RAIN DEVELOPING BETWEEN 12Z AND 15Z...SPREADING INTO
NORTHEAST MISSOURI/WEST CENTRAL ILLINOIS PROBABLY DURING THE MID TO
LATE MORNING. INSTABILITY WILL BUILD RAPIDLY DURING THE LATE MORNING
WITH MUCAPE EXCEEDING 2500 J/KG ACCORDING TO MOST GUIDANCE AND DEEP
LAYER SHEAR AROUND 50-60KTS SO SEVERE STORMS WILL BE POSSIBLE AT ANY
TIME DURING THE LATE MORNING. HOWEVER...THE MAIN SHOW WILL LIKELY
DEVELOP DURING THE LATE AFTERNOON OR EARLY EVENING AS ANOTHER LOBE
OF VORTICITY WRAPS AROUND THE SOUTH SIDE OF THE UPPER LEVEL LOW AND
PUSHES THE SURFACE FRONT INTO NORTHWEST MISSOURI. WHATEVER`S LEFT OF
THE CAP WILL ALSO BE WIPED AWAY. AFTERNOON CAPE VALUES LOOK TO BE IN
EXCESS OF 3000 J/KG WITH SHEAR STAYING ABOVE 50KTS. THINK THERE WILL
BE SOME DISCRETE STORMS INITIALLY...BUT WITH LITTLE OR NO CAP AND
COPIOUS CAPE WE SHOULD SEE THE STORMS CONGEAL INTO A LINE. CANNOT
RULE OUT ANY KIND OF SEVERE WEATHER INCLUDING DAMAGING WINDS...LARGE
HAIL...AND EVEN TORNADOES WITH THE LINE. THE LINE SHOULD PROGRESS AT
A MODERATE PACE INTO SOUTHEAST MISSOURI BY EARLY MORNING SATURDAY.
OF COURSE WITH THE HEAVY RAIN POTENTIAL AND NEARLY SATURATED GROUND
THERE WILL BE A CONTINUING FLASH FLOOD THREAT...AND IT`S LIKELY THE
FLASH FLOOD WATCH WILL NEED TO BE EXPANDED EITHER EARLY FRIDAY
MORNING OR FRIDAY AFTERNOON TO COVER THE REST OF THE CWFA.
CURRENT THINKING IS THAT THE INITIAL LINE OF CONVECTION WILL WEAKEN
OVER THE EASTERN OZARKS SATURDAY MORNING. HOWEVER THERE WILL BE
REDEVELOPMENT BY EARLY SATURDAY AFTERNOON...PERHAPS AS FAR NORTHWEST
AS THE COLUMBIA AREA...AS THE SURFACE COLD FRONT FINALLY KICKS INTO
GEAR AND HEADS EAST. SPC STILL HAS THE SOUTHEASTERN 2/3 OF THE CWFA
IN A SLIGHT RISK SATURDAY...INCLUDING THE STL METRO AREA AND POINTS
ALONG AND EAST OF THE I-44/I-55 CORRIDORS. THE UPPER LEVEL
SHORTWAVE FINALLY SWINGS THROUGH SATURDAY AFTERNOON/EARLY EVENING
PUSHING THE COLD FRONT SOUTHEAST INTO THE LOWER
MISSISSIPPI/TENNESSEE VALLEYS.
(SUNDAY THROUGH NEXT THURSDAY)
HIGH PRESSURE IS STILL EXPECTED TO BUILD ACROSS THE MIDWEST SUNDAY
AND CONTROL THE WEATHER AT LEAST THROUGH MONDAY. EXPECTING BELOW
NORMAL TEMPERATURES AND LESS HUMID CONDITIONS THROUGH THAT PERIOD.
MEDIUM RANGE GUIDANCE IS A LITTLE FASTER THAN YESTERDAY IN PUSHING
THE HIGH EAST AWAY FROM THE MID-MISSISSIPPI VALLEY. SOUTHERLY FLOW
RETURNS TUESDAY AND BOTH THE GFS AND ECMWF PRINT OUT PRECIP LATE
TUESDAY THROUGH THURSDAY AS A SHORTWAVE DIPS INTO THE NORTHERN
PLAINS. THE GFS IS MUCH MORE DYNAMIC WITH THIS WAVE THAN THE ECMWF
AND THEREFORE CRANKS OUT A LOT MORE PRECIP. HAVE OPTED TO JUST
STICK WITH CHANCE POPS FOR THIS PERIOD RIGHT NOW. WILL CONTINUE TO
WATCH THIS NEXT WAVE AND INCREASE POPS AS NEEDED IF BOTH MODELS
CONTINUE TO TREND WETTER.
CARNEY
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 136 PM CDT THU MAY 30 2013
MODELS ARE UNCLEAR ON TIMING OF SHOWERS/THUNDERSTORMS FOR EACH
TAF...SO AMENDMENTS WILL BE NECESSARY BASED ON RADAR TRENDS
THE NEXT 12 HOURS. CURRENT THINKING IS THAT THUNDERSTORMS WILL
CONTINUE OVER EASTERN MO/WESTERN IL THE NEXT FEW HOURS...AND THAT
THE LINE OVER WESTERN MO WILL ADVANCE SLOWLY EASTWARD THE REST OF
THE AFTERNOON AND EVENING. STORMS MAY BE SEVERE WITH STRONG WINDS
GUSTS AND HAIL. EXPECT MAINLY VFR CONDITIONS EXCEPT IN THE HEAVIER
CORES WHERE IFR VSBYS/CIGS CAN BE EXPECTED.
SPECIFICS FOR KSTL...THUNDERSTORMS CURRENTLY AROUND LAMBERT WILL
INTERMITTENTLY BRING IFR CONDITIONS IN HEAVY RAIN. CANNOT RULE OUT
HAIL AND STRONG WINDS GUSTS WITH ANY OF THE STRONGER CORES. LINE
OF STORMS CURRENTLY OVER WESTERN MO WILL NOT REACH KSTL UNTIL
AFTER 00Z.
BRITT
&&
.PRELIMINARY POINT TEMPS/POPS...
SAINT LOUIS 71 84 69 81 / 80 60 90 70
QUINCY 67 80 65 77 / 80 80 80 50
COLUMBIA 67 81 66 78 / 80 70 90 50
JEFFERSON CITY 67 82 68 78 / 80 60 90 60
SALEM 69 83 71 81 / 70 50 70 70
FARMINGTON 68 82 69 81 / 70 50 90 70
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR AUDRAIN MO-BOONE
MO-CALLAWAY MO-COLE MO-FRANKLIN MO-GASCONADE MO-JEFFERSON
MO-KNOX MO-LEWIS MO-LINCOLN MO-MARION MO-MONITEAU MO-MONROE
MO-MONTGOMERY MO-OSAGE MO-PIKE MO-RALLS MO-SHELBY MO-ST.
CHARLES MO-ST. LOUIS CITY MO-ST. LOUIS MO-WARREN MO.
IL...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR ADAMS IL-BROWN
IL- CALHOUN IL-GREENE IL-JERSEY IL-MACOUPIN IL-MADISON IL-
MONROE IL-PIKE IL-ST. CLAIR IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
640 PM CDT Thu May 30 2013
.SHORT TERM...(This Evening through Friday)
Issued at 325 PM CDT THU MAY 30 2013
Leading edge of storms should move east of the forecast area by 4 or
so leaving just the trailing stratiform area of rainfall with
embedded convection through the early evening. So through this
evening the chances of rain/embedded storms will diminish from west
to east. The focus then shifts to tonight for the possibility of
convection erupting in eastern Kansas and then spreading into
western Missouri. There is a quite a bit of uncertainty with how
things may evolve tonight as several short-range models keep things
quiet overnight. However, the more reliable HRRR, which has been
handling today`s convection very well, has been consistent in
developing convection somewhere across northeastern Kansas and
moving into west central and northwestern Missouri. This roughly
corresponds to an area of strong isentropic lift with a focusing of
the LLJ depicted by the GFS. There should be enough instability and
shear to lead to storm organization so a few severe storms are
possible with large hail the biggest threat with damaging winds
possible as well. Will keep the flash flood watch going as is given
recent heavy rains across northern Missouri and persistent moderate
to heavy rain across the southern portions of the forecast and the
uncertainty with where any heavy rain may set up tonight. Some areas
within the watch area have good chance of seeing heavy rainfall
tonight and some much river flooding ongoing and already saturated
soils, it won`t take much more rain to lead to rapid runoff and
flash flooding.
.LONG TERM...(Friday Night through Thursday)
Issued at 325 PM CDT THU MAY 30 2013
Cold front will slide through the forecast area Friday night,
pushing the threat for thunderstorms southeast of the area.
Elongated area of high pressure will build into much of the Plains
over the weekend providing dry conditions and comfortable
temperatures. Cold air advection on Saturday and Sunday will keep
highs in the upper 60 and lower 70s.
Warm air advection on the back side of this area of high pressure
will set the stage for an increase in rain chances next week.
Initial rain chances will begin early Tuesday when a weak shortwave
will eject into the Plains ahead of a deeper wave digging into the
Upper Midwest. This system will eventually drop a cold front and
associated chances for showers and thunderstorms into the area by
mid-week, though there are still considerable model differences with
the timing of this activity.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday Evening)
Issued at 639 PM CDT THU MAY 30 2013
North-south line of scattered convection over north central/central
KS tracking ENE is being handled best by the HRRR (short- range
convective model). Activity is tied to a shortwave and will likely
survive past sunset, although in a slightly weakened state. AWIPS
tracking tool is in line with HRRR and places activity into the KSTJ
and KMCI terminals between 02z-03z. Convection could hang around for
another hour or two thereafter.
Better chances for more organized and stronger convection appears it
will be tied to the re-development of the low-level jet. Several
short-range convective models including the HRRR, local WRF and NAM
develop an MCS into east central KS/west central MO during the pre-
dawn hours of Friday morning. For the most part expect VFR ceilings
with brief periods of MVFR possible. Should see activity clear out
mid/late morning.
With another shortwave moving into northeast KS/northwest MO and a
hint of a weak front over northwest MO can see signs for scattered
late afternoon convection to form along the weak front during the
late afternoon hours. If this activity forms it will likely be fairly
intense.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...FLASH FLOOD WATCH through Friday evening FOR KSZ025-057-060-
102>105.
MO...FLASH FLOOD WATCH through Friday evening FOR MOZ001>008-011>017-
020>025-028>033-037>040-043>046-053-054.
&&
$$
SHORT TERM...CDB
LONG TERM...Hawblitzel
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS GLASGOW MT
836 PM MDT THU MAY 30 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SATURDAY...
UPDATE...A FEW TWEAKS TO THE CURRENT FORECAST MADE. HRRR MODEL
DOES SHOW THE EASTERN ZONES BECOMING MORE SHOWERY IN NATURE
OVERNIGHT. KEPT THE FLOOD WATCH GOING AND CURRENT FLOOD WARNINGS
WERE EXTENDED. PROTON
CLOSED UPPER LOW NEAR SE CORNER OF MONTANA THIS AFTERNOON
CONTINUES TO DRAW UP GULF OF MEXICO MOISTURE THIS AFTERNOON WITH
ONE OF THE MOST INTENSE BANDS OF PRECIPITATION YET NOW MOVING WEST
THROUGH THE CWA EARLY THIS AFTERNOON.
WILL KEEP THE FLOOD WATCH UP THROUGH FRIDAY AS THIS BAND OF RAIN IS
EXPECTED TO LINGER IN THE CWA INTO THIS EVENING. SYSTEM WILL START
TO DRIFT THROUGH THE DAKOTAS FRIDAY WITH AN UPPER RIDGE TO MOVE IN
SATURDAY. THE RAIN IS EXPECTED TO FINALLY END FRIDAY NIGHT WITH
CLEARING SKIES ALLOWING TEMPERATURES TO REALLY COOL BY SATURDAY
MORNING. SOME PLACES MAY REACH THE UPPER 30S WHERE GOOD RADIATIONAL
COOLING TAKES PLACE. PATCHY FOG IS POSSIBLE TOO BUT WITH LOTS OF DRY
AIR COMING IN FROM CANADA...CONFIDENCE IS NOT HIGH ENOUGH TO ADD TO
GRIDS YET.
WITH GFS LOOKING TOO WET WITH THIS AFTERNOON...WENT WITH A NAM/ECMWF
AND SREF BLEND FOR QPF. WETTEST PERIOD WILL BE INTO THIS EVENING
WHERE UP TO .6" IS EXPECTED...MAINLY IN VALLEY AND GARFIELD COUNTIES.
ON SATURDAY...SUBSIDENCE FROM THE UPPER RIDGE SHOULD ALLOW FOR
CUMULUS SUPPRESSION AND LIGHT WINDS. TEMPERATURES WILL TOP OUT ABOUT
5 DEGREES BELOW NORMAL. JAMBA
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
THE LATEST MODEL RUNS KEEP EASTERN MONTANA IN AN UNSETTLED
PATTERN THROUGH THE EXTENDED. A LARGE UPPER-LEVEL TROUGH SWINGS
THROUGH THE REGION SUNDAY THROUGH TUESDAY BRINGING PRECIPITATION
TO MOST OF CWA DURING THIS TIME. AN UPPER-LEVEL RIDGE WILL BUILD
OVER OF THE WESTERN STATES TUESDAY THROUGH THURSDAY... THIS WILL HELP
NUDGE THE TROUGH OUT OF MONTANA INTO THE NORTHERN PLAINS/UPPER
MIDWEST AND ALLOW THE AIRMASS TO DRY OUT. AEC
PREVIOUS DISCUSSION... SYNOPTIC SET UP... A LARGE TROUGH EXTENDS
FROM THE HUDSON BAY DOWN INTO THE CENTRAL US PLAINS WHILE A SECOND
ONE RUNS FROM THE THE PACIFIC NORTHWEST ALONG THE BRITISH
COLUMBIAN SHORE AND BACK TO THE GULF OF ALASKA. A WEAK TROUGH
RIDGE IS WEDGED BETWEEN THESE TWO LARGE FEATURES FROM UTAH THROUGH
CENTRAL MONTANA AND UP INTO THE NORTHWEST TERRITORIES.
SATURDAY NIGHT... UPPER SHORTWAVE RIDGE PUSHES INTO NORTHEAST
MONTANA IN THE WAKE OF THE LARGE STORM SYSTEM WHICH WILL LEAD TO
MUCH DRIER CONDITIONS. POPS WERE TRENDED DOWN TO NON MENTION
THROUGH SATURDAY NIGHT AS ENSEMBLE MODELS ARE PLACING NO QPF
ACROSS THE AREA AND DRY AIR FROM CANADA IS ANTICIPATED TO ENTER.
SUNDAY INTO TUESDAY... MODELS CONTINUE TO HINT AT THE POTENTIAL
FOR CONVECTION INITIATION AS A SHORTWAVE TROUGH BREAKS DOWN THE
RIDGE ALOFT AND INTERACTS WITH A DEVELOPING THETA-E RIDGE. MODELS
DIFFER ON TIMING AND PLACEMENT OF THIS WAVE AS WELL AS INTENSITY.
THE LATEST EC AND GFS HAVE INITIATION OVER GREAT FALL TERRITORY
AND JUST OFF THE FRONT RANGE. THEN BECOMING A MORE NOCTURNAL EVENT
FOR THE GGW CWA. IF THIS VERIFIED... SOME STORMS COULD BECOME
STRONG WITH A GOOD LIGHTNING SHOW... BUT LOCALLY SEVERE WEATHER
MIGHT BE HARDER TO COME BY THAN PREVIOUS RUNS PREDICTED. A SECOND
ROUND OR STRONG THUNDER IS POSSIBLE MONDAY AFTERNOON AND
EVENING... BUT SHOULD THE CENTER OF THE MID LEVEL LOW THAT WRAPS
UP PASSING GGW BEFORE THE AFTERNOON CONDITIONS WILL QUICKLY BECOME
LESS FAVORABLE. THUS...CONFIDENCE IS INCREASING ON MORE RAINFALL
MONDAY AND MONDAY EVENING. BUT THE DETAILS SUCH AS TIMING AND
PLACEMENT AND HOW STRONG THE STORMS WILL BE WILL STILL NEED TO BE
WORKED OUT WITH LATER SHIFTS. MODELS STILL INDICATE A STRONG UPPER
LEVEL JET STREAK OVER THE AREA SOMETIME LATE WEEKEND WHICH COULD
MIX DOWN IN STORMS IF TIMING IS RIGHT.
TUESDAY NIGHT AND BEYOND... MULTI MODEL ENSEMBLES BECOME
INCREASINGLY IN DISAGREEMENT AT THIS POINT INDICATING LOWER
CONFIDENCE. WHAT CAN BE INFERRED FROM THE TEA LEAVES IS A RIDGE
BUILDING ACROSS THE HIGH PLAINS THROUGH WEDNESDAY NIGHT ALLOWING
FOR A WARMING TREND THROUGH MID WEEK AND BUMPING UP DAYTIME HIGHS.
AFTERWARD A TROUGH BEHIND THIS RIDGE IS EXPECTED TO ROLL INTO THE
PACIFIC NORTHWEST AROUND THURSDAY. THIS WOULD SEND SHORTWAVES
ZOOMING OVER THE HIGH PLAINS AND NORTHEAST MONTANA AND COULD
GENERATE A BIT OF CONVECTION. GAH/MALIAWCO
&&
.AVIATION...
MVFR TO IFR CONDITIONS ARE EXPECTED THROUGH MOST OF THE TAF CYCLE
AS WIDESPREAD RAIN SHOWERS MOVE THROUGH THE AREA. EMBEDDED POCKETS
OF HEAVY RAIN MAY CAUSE BRIEF LIFR CONDITIONS. NORTHERLY WINDS
WITH SPEEDS OF 15 TO 20 KTS WILL PERSIST THROUGH THE TAF CYCLE.
AEC/BLM
&&
.HYDROLOGY...
HEAVIEST RAIN WILL COME THIS EVENING WITH A DIMINISHING TREND
THEREAFTER. AMOUNTS OF UP TO AN INCH THIS EVENING CAN BE EXPECTED
ESPECIALLY IN VALLLEY AND GARFIELD COUNTIES. A FLOOD WATCH WILL
REMAIN IN EFFECT FOR THE ENTIRE AREA.
GREATEST AMOUNTS OF RAIN LOOK TO OCCUR SOUTH OF A MALTA TO
GLENDIVE LINE WITH OVER 4 INCHES EXPECTED IN AN AREA FROM JORDAN
TO MILES CITY TO CIRCLE.
PLEASE KEEP IN MIND THE RIVER FORECASTS INCLUDE AN EXTENDED PERIOD
OF PRECIPITATION FORECASTS (120 HOURS OF QPF) AND THE HIGH LEVELS
ARE A LOW CONFIDENCE FORECAST. JAMBA
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH FRIDAY AFTERNOON FOR CENTRAL AND SOUTHEAST
PHILLIPS...CENTRAL AND SOUTHERN VALLEY...DANIELS...DAWSON...
EASTERN ROOSEVELT...GARFIELD...MCCONE...NORTHERN PHILLIPS...
NORTHERN VALLEY...PETROLEUM...PRAIRIE...RICHLAND...SHERIDAN...
SOUTHWEST PHILLIPS...WESTERN ROOSEVELT...WIBAUX.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
829 PM MDT THU MAY 30 2013
.UPDATE...
WE HAVE DECIDED TO EXTEND THE HIGH WIND WARNING OVER SHERIDAN AND
SOUTHERN BIG HORN COUNTIES INTO FRI EVENING. THE SURFACE LOW NEAR
THE ND/SD BORDER WILL MAKE ONLY SLOW PROGRESS EASTWARD DURING THE
NEXT 24 HOURS...SO THE LOW-LEVEL PRESSURE GRADIENT WILL NOT RELAX
MUCH ACROSS THE AREA THROUGH FRI. FORECAST SOUNDINGS FOR SHERIDAN
FROM THE 18 UTC NAM AND RECENT RAP RUNS SHOW A CORE OF 50 KT WIND
SPEEDS AS LOW AS 2500 TO 3000 FT AGL TONIGHT AND FRI. WIND SPEEDS
ALOFT ARE LOWER ON THE 18 UTC GFS...BUT ITS MOS SHOWS ENOUGH WIND
TO SUPPORT A WARNING /EVEN WHEN TAKING INTO ACCOUNT ITS HIGH BIAS
WITH WINDS/.
OTHERWISE...THE GOING FORECAST IS LARGELY ON TRACK AND ONLY A FEW
ADJUSTMENTS WERE MADE WITH THE EVENING UPDATE BASED ON THE TRENDS
IN OBSERVATIONS AND RECENT GUIDANCE. RAIN IS NOT OVER WITH ACROSS
THE AREA...AND SINCE 2 TO 4 INCHES HAS ALREADY FALLEN IN THE LAST
36 HOURS IN MANY SPOTS...HYDROLOGIC ISSUES ARE A DEFINITE CONCERN
FOR US. SEVERAL FLOOD ADVISORIES ARE IN EFFECT OVER SOUTH CENTRAL
AND ESPECIALLY SOUTHEASTERN MT. MANY SMALL STREAMS AND RIVERS ARE
BANKFULL...AND IN SOME AREAS MINOR FLOODING IS OCCURRING. WE FEEL
THAT THE LARGER RIVERS HAVE ENOUGH CAPACITY TO TAKE IN THIS WATER
WITHOUT REACHING DEFINED FLOOD STAGES. HOWEVER...THE CONTRIBUTION
FROM SMALLER TRIBUTARIES AND LOCAL RUNOFF WILL CERTAINLY GENERATE
RISES EVEN ON SOME LARGER RIVERS. FOR EXAMPLE...EVEN THOUGH WE DO
NOT ANTICIPATE FLOODING ON THE YELLOWSTONE RIVER...WE HAVE SEEN A
PRETTY SHARP RISE IN LEVEL AT FORSYTH AND MILES CITY. THOSE RISES
WILL LIKELY CONTINUE INTO FRI SINCE THOSE AREAS HAVE SEEN SOME OF
THE HEAVIEST RAIN. SCHULTZ
&&
.SHORT TERM...VALID FOR FRI AND SAT...
DEEP UPPER LOW CURRENTLY SITTING OVER WESTERN SOUTH DAKOTA IS NOT
EXPECTED TO MOVE MUCH OVER THE NEXT 24 HOURS. THIS WILL MEAN MORE
WET WEATHER FOR THE AREA...ESPECIALLY OVER LOCATIONS EAST OF
BILLINGS. GFS HAS BEEN THE WINNER IN PROJECTING THIS SYSTEM SO
WILL RIDE IT OUT TO COMPLETION.
THE UPPER LOW IS PROGGED TO GET PULLED INTO CENTRAL SOUTH DAKOTA
THIS EVENING AND AS CONVECTION ORGANIZES OVER IOWA AND WISCONSIN
THIS WILL ALLOW THE LOW TO REFORM OVER EASTERN SOUTH DAKOTA EARLY
FRIDAY. PLENTY OF MOISTURE WILL WRAP AROUND THIS LOW FROM
NORTHEAST MONTANA AND GET INTO THE EASTERN HALF OF THE FORECAST
AREA. AN ADDITIONAL 1 TO 3 INCHES OF RAINFALL IS EXPECTED EAST OF
BILLINGS TONIGHT THROUGH FRIDAY. DOWNSLOPE NORTHWEST WINDS HAVE
KEPT PRECIPITATION AT BILLINGS LIGHT THIS AFTERNOON BUT BELIEVE
MODERATE RAIN WILL EVEN ROTATE BACK INTO BILLINGS THIS EVENING.
WILL KEEP FLOODING HIGHLIGHTS OUT.
WINDS HAVE GUSTED TO 62 MPH NORTHEAST OF SHERIDAN TODAY THUS
VERIFYING THE HIGH WIND WARNING. WINDS WILL CONTINUE TO BE STRONG
THIS EVENING AND WILL NOT DROP THE WARNING AT THIS TIME.
PRECIPITATION WILL FINALLY TAPER OFF OVER THE AREA FRIDAY NIGHT.
RAISED POPS INTO THE AFTERNOON AND EVENING FOR MOST LOCATIONS AS
THIS PROCESS HAVE BEEN SLOWED DOWN AGAIN. RIDGING WILL MOVE IN FOR
SATURDAY AND GIVE THE AREA A MUCH NEEDED DRY DAY. TWH
.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...
EXTENDED MODELS WERE IN PRETTY GOOD AGREEMENT IN MOVING AN UPPER
LOW FROM W CANADA INTO THE REGION ON SUN. THE LOW WILL ROTATE E
THROUGH TUE WHILE REMAINING N OF THE FORECAST AREA. THERE WERE
SOME TIMING DIFFERENCES IN HOW FAST THE LOW MOVES E ON TUE...WITH
THE ECMWF MOVING IT SLOWER THAN THE GFS.
SUN WILL START OUT DRY AHEAD OF THE SYSTEM...THEN SCATTERED
AFTERNOON SHOWERS AND THUNDERSTORMS WILL SPREAD INTO WESTERN PARTS
OF THE AREA. LOWERED HIGH TEMPERATURES SLIGHTLY BASED ON LATEST
700 MB FORECAST TEMPERATURES. STILL LOOKING AT READINGS IN THE
70S. PRECIPITATION CHANCES WILL INCREASE ACROSS THE AREA SUN NIGHT
AND MON WITH THE BEST CHANCES OVER THE W...BASED ON THE TRACK OF A
STRONG SHORTWAVE AND GOOD MOISTURE AMOUNTS. HIGHS WILL ONLY REACH
THE 60S DUE TO THE PRECIPITATION ON MON. DESPITE MODEL DIFFERENCES
EMERGING ON TUE...ALL THE MODELS SUPPORTED A CHANCE OF
PRECIPITATION DUE TO THE SYSTEM/S CLOSE PROXIMITY. THE BELOW
NORMAL TEMPERATURES WILL CONTINUE ON TUE. SOME DRYING WILL TAKE
PLACE BEHIND THE LOW FOR WED THROUGH THU AS WEAK RIDGING BUILDS
OVER THE REGION. TEMPERATURES WILL REBOUND BACK INTO THE 70S.
ARTHUR
&&
.AVIATION...
RAIN WILL CONTINUE OVER THE AREA THROUGH FRI. THE BEST CHANCES
FOR RAIN WILL BE FROM KBIL TO KSHR E. EXPECT MVFR
CONDITIONS...WITH IFR CONDITIONS IN HEAVIER RAIN. GUSTY W TO NW
SURFACE WINDS WILL ACCOMPANY THE PRECIPITATION THROUGH FRI.
STRONGEST WINDS LOOK TO BE FROM KSHR TO KMLS E...WHERE GUSTS OVER
35 KTS ARE POSSIBLE. THE MOUNTAINS WILL BE OBSCURED. STC
&&
.PRELIMINARY POINT TEMP/POPS...
FRI SAT SUN MON TUE WED THU
-----------------------------------------------------------
BIL 047/057 045/067 050/076 052/069 048/068 049/072 052/075
97/W 61/B 11/B 44/T 33/T 22/T 21/B
LVM 042/055 038/068 043/073 043/067 043/066 041/072 045/073
46/W 41/B 12/T 66/T 34/T 32/T 22/T
HDN 046/055 045/069 046/077 051/071 048/069 046/073 050/075
+8/W 71/B 11/B 32/T 33/T 22/T 11/B
MLS 049/053 046/067 049/075 051/070 048/068 047/071 051/074
+9/W 92/W 10/B 34/T 33/T 22/T 11/U
4BQ 046/053 044/066 047/074 048/071 046/066 046/069 047/073
+9/W 93/W 10/B 32/T 33/T 22/T 11/U
BHK 047/053 043/063 044/070 045/068 044/064 043/066 046/070
+9/W 92/W 00/B 44/T 33/T 22/T 12/T
SHR 043/054 043/065 045/075 047/071 046/066 043/068 045/072
88/W 62/W 11/B 22/T 33/T 22/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...FLASH FLOOD WATCH IN EFFECT THROUGH FRIDAY AFTERNOON FOR
ZONES 29-31-36>38-57-58.
HIGH WIND WARNING IN EFFECT UNTIL 9 PM MDT FRIDAY FOR ZONE
38.
WY...HIGH WIND WARNING IN EFFECT UNTIL 9 PM MDT FRIDAY FOR ZONE
99.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1004 PM CDT THU MAY 30 2013
.UPDATE...
CONVECTION IS FINALLY WINDING DOWN ACROSS EASTERN NEBRASKA AND
SOUTHWEST IOWA...WITH A FEW SHOWERS AND ISOLATED LIGHTNING STRIKES
OCCURRING IN PARTS OF NORTHEAST NEBRASKA AND IN AREAS EAST AND
NORTHEAST OF THE COUNCIL BLUFFS METRO AREA. EXPECT IOWA ACTIVITY
TO MOVE EAST OF OUR AREA WELL BEFORE MIDNIGHT...AND NORTHEAST
NEBRASKA ACTIVITY TO PERSIST FOR A COUPLE OF HOURS. AFTER
MIDNIGHT...SHORT RANGE HRRR AND RAP MODELS ARE BOTH SUGGESTING
SOME SHOWER DEVELOPMENT IN WESTERN NEBRASKA WILL SWING EAST
THROUGH EASTERN NEBRASKA AND SOUTHWEST IOWA. SOME INDICATION OF
THIS ACTIVITY FORMING NOW IN SOUTHWEST NEBRASKA...SO HAVE NO
REASON TO REMOVE THE CHANCE FOR MORE SHOWERS LATER TONIGHT AS PER
GOING FORECAST.
DERGAN
&&
.PREV DISCUSSION... /ISSUED 302 PM CDT THU MAY 30 2013/
DISCUSSION...
MAIN CONVECTIVE ACTIVITY HAS SHIFTED EAST OF THE AREA THIS
AFTERNOON WITH CLOSED UPPER LOW LOCATED OVER WESTERN SOUTH DAKOTA
AND SURFACE TROUGH JUST NOSING INTO EASTERN NEBRASKA.
ALTHOUGH THE CHANCE OF THUNDERSTORMS WILL REMAIN ACROSS THE AREA
TONIGHT AND FRIDAY...GENERAL TREND WILL BE TOWARD MORE STABLE
CONDITIONS BY LATE SATURDAY AND THROUGH THE REMAINDER OF THE
WEEKEND AS THE UPPER SYSTEM TRACKS TOWARD THE GREAT LAKES REGION
AND HIGH PRESSURE BUILDS INTO THE CENTRAL PLAINS. TEMPERATURES
WILL BE TURNING COOLER FOR THE WEEKEND AS A COLD FRONT MOVES
THROUGH THE REGION WITH CLOUDS AND SHOWERS ASSOCIATED WITH THE
UPPER LOW LIKELY TO KEEP HIGHS ONLY IN THE 60S FOR SATURDAY.
BREEZY CONDITIONS ALSO EXPECTED ON SATURDAY BEHIND THE FRONT AS
THE COOLER AIR MOVES INTO THE REGION. WARMER AIR RETURNS FOR
SUNDAY SURFACE HIGH SHIFTS EAST WITH CONSIDERABLE SUNSHINE
EXPECTED.
EXTENDED PERIOD LOOKS LIKE IT COULD TURN WET AGAIN AS THE
UPPER LEVEL PATTERN TAKES ON SIMILAR CHARACTERISTICS OF
THIS PAST WEEKS SYSTEM. ANOTHER CLOSED LOW MOVES INTO THE
NORTHERN ROCKIES BY MONDAY THEN TRACKS EAST ACROSS THE NORTHERN
PLAINS AND INTO THE UPPER MIDWEST BY THURSDAY. MODELS HOWEVER
DIFFER ON STRENGTH AND TIMING OF SHORT WAVES SO LIMITED CONFIDENCE
IN EITHER SOLUTION AT THIS TIME.
FOBERT
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
254 PM CDT WED MAY 29 2013
.UPDATE...
ISSUED AT 808 AM CDT WED MAY 29 2013
GIVEN INCREASE IN SHOWERS/FAIRLY WEAK THUNDERSTORMS ACROSS MUCH OF
THE SOUTHEAST 1/4 OF THE CWA ALREADY THIS MORNING...HAVE UPPED
POPS TO 50 PERCENT THIS MORNING ACROSS MUCH OF THE EASTERN 1/2 OF
THE CWA...WHILE KEEPING LOWER POPS IN THE WEST. AM NOT
ANTICIPATING SEVERE STORMS THIS MORNING...BUT SOME SMALL HAIL IS
NOT OUT OF THE QUESTION. ITS A COMPLEX CONVECTIVE SCENARIO
TODAY..WITH THE PRESENCE OF SEVERAL SUBTLE DISTURBANCES IN THE MID
LEVEL FLOW OUT AHEAD OF THE PRIMARY SHORTWAVE TROUGH APPROACHING
FROM THE ROCKIES...VERY POSSIBLY ENSURING THAT AT LEAST SOME
PORTION OF THE CWA WILL SEE RAIN AT ANY GIVEN TIME TODAY.
ON ANOTHER NOTE...REGARDING THE THURSDAY/FRIDAY FIRE WEATHER
CONCERNS FOR OUR WESTERN CWA OUTLINED IN THE PREVIOUS
DISCUSSION...UPON FURTHER INSPECTION THE OFFICIAL FIRE WEATHER
FUEL STATUS FOR ALL NEBRASKA ZONES WAS SET TO UNFAVORABLE FOR
LARGE FIRE GROWTH AS OF YESTERDAY. THIS BASICALLY MEANS THAT
VEGETATION IS GREEN ENOUGH/WET ENOUGH TO PRECLUDE MAJOR FIRE
WEATHER PROBLEMS...ALTHOUGH OF COURSE CAUTION SHOULD STILL BE
USED WHEN BURNING. AS A RESULT OF THIS UNFAVORABLE FUEL
STATUS...WILL BE REMOVING ELEVATED FIRE DANGER MENTION FROM THE
HAZARDOUS WEATHER OUTLOOK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 406 AM CDT WED MAY 29 2013
MAIN FORECAST CONCERN WILL BE
CHANCES FOR THUNDERSTORMS.
RADAR FROM KLNX SHOWS THAT MANY OF THE THUNDERSTORMS TO THE WEST
HAVE DIMINISHED BUT A RAIN SHIELD REMAINS. THERE ARE A COUPLE OF
BOUNDARIES THAT ARE SHOWING UP ON KUEX RADAR...ONE FROM THE
CONVECTION TO THE WEST AND ANOTHER FROM CONVECTION TO THE SOUTH.
WHEN THESE COLLIDE APPEARS TO BE THE BEST CHANCE FOR SOME SHOWERS
AND THUNDERSTORMS EARLY THIS MORNING. THERE HAVE BEEN A FEW THAT
GOT STARTED BUT SOON WANED.
MODELS ARE SIMILAR WITH THE UPPER LEVEL LOW THAT MOVES FROM THE
NORTHERN ROCKIES INTO THE NORTHERN HIGH PLAINS TODAY AND TONIGHT.
THERE IS A SURFACE LOW ON THE HIGH PLAINS THAT TRIES TO MOVE
EAST...BUT DOES NOT MAKE IT THROUGH THE AREA. THE SURFACE PRESSURE
GRADIENT TIGHTENS THIS MORNING AHEAD OF THE SURFACE LOW. WINDS
WILL START TO INCREASE. THE STRONGEST WINDS WILL BE IN THE
SOUTHERN PART OF THE FORECAST AREA...BUT BREEZY CONDITIONS ARE
EXPECTED ACROSS THE AREA TODAY. WILL KEEP THE WIND ADVISORY AS IS
FOR NOW.
THE NEXT CONCERN WILL BE WHEN THUNDERSTORMS WILL DEVELOP. THE
UPPER LEVEL WAVE WILL START TO AFFECT THE AREA THIS MORNING AND
SOME THUNDERSTORM DEVELOPMENT IS NOT OUT OF THE QUESTION. THE NAM
AND THE GFS SHOW A DEFINITIVE INCREASE IN QPF DURING THE MORNING
BUT THE RAP AND 4KM WRF BOTH HOLD OFF UNTIL LATER. WILL KEEP SOME
LOW POPS IN FOR THE MORNING...BUT RAMP IT UP LATER THIS MORNING
AND EARLY THIS AFTERNOON WHEN THE UPPER WAVE IS MOVING INTO THE
AREA. SEVERE WEATHER IS EXPECTED DURING THE AFTERNOON AND EVENING
WHEN MUCAPES ARE EXPECTED TO BE OVER 3500 J/KG. THE SEVERE WEATHER
WILL LIKELY CONTINUE INTO THE EVENING BUT THE SEVERE THREAT WILL
DIMINISH LATER TONIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 406 AM CDT WED MAY 29 2013
MAIN STORY: A REPRIEVE FROM THE THREAT OF TSTMS WILL OCCUR AS
TEMPS TUMBLE TO BELOW NORMAL THIS WEEKEND...THEN THE THREAT
RETURNS EARLY NEXT WEEK AS SUMMER WARMTH RETURNS.
ALOFT: THE TROF CURRENTLY MOVING THRU THE W WILL CLOSE OFF OVER
THE NRN PLAINS THU NGT-FRI BEFORE OPENING UP AND SLOWLY MIGRATING
INTO THE GREAT LAKES AND MIDWEST THIS WEEKEND. A MODEST SHRTWV
RIDGE WILL ADVANCE INTO THE PLAINS SUN-MON...AS THE NEXT TROF
MOVES INTO THE PAC NW. ALL THE WHILE THE WESTERLIES WILL GRADUALLY
LIFT BACK INTO THE NRN USA.
SFC: A COOL FRONT WILL MOVE THRU LATE THU AFTN/EVE. HOWEVER...THE
TAIL END OF THE FRONT MAY NOT ENTIRELY CLEAR THE SE FRINGE OF OUR
FCST AREA UNTIL FRI EVNG. THIS FRONT WILL BE FOLLOWED BY A SECONDARY
STRONGER COLD FRONT FRI EVNG. HIGH PRES DRIFTS THRU SUN WITH RETURN
FLOW INTENSIFYING WITH ITS DEPARTURE TO THE E AND REDEVELOPMENT OF
THE LEE TROF...AS LOW PRES HEADS E ALONG THE USA-CAN BORDER. HEAT
BUILDS OVER THE REGION MON-TUE UNTIL THE NEXT COOL FRONT MOVES THRU
TUE NGT OR WED. COOL HIGH PRES THEN BUILDS IN THU.
HAZARDS: FIRE WX MAY BECOME A CONCERN THU/FRI BETWEEN 2PM-8PM.
ATTM DO NOT ENVISION A RFW BUT FIRE DANGER COULD BE ELEVATED.
THERE ARE MULTIPLE CHANCES FOR TSTMS THU-FRI BUT COVERAGE AND
INTENSITY WILL BE LOW DUE TO DIMINISHING MSTR/INSTABILITY. SOME
SVR TSTMS WILL BE POSSIBLE EARLY NEXT WEEK AS INSTABILITY
INCREASES.
THE DAILY DETAILS...
THU: THE BACKSIDE OF AN MCS MAY STILL LINGER SE OF THE TRI-CITIES
IN THE MRNG. OTHERWISE DECREASING CLOUDS.
THE DRYLINE WILL PRESS INTO THE FCST AREA IN THE WARM SECTOR OF A
992 MB SFC LOW OVER THE DAKOTAS...WITH ITS ASSOCIATED COOL FRONT
DROPPING INTO THE NW FRINGE LATE. THE LFQ OF THE 80 KT ULJ WILL BE
OVER THE CNTRL PLAINS...BUT HIGH QUALITY MSTR WILL BE RAPIDLY ON THE
DECREASE. AN ISOLATED SHWR/TSTM IS POSSIBLE...MAINLY E OF HWY 281.
FIRE DANGER: WE NEED TO WATCH ALONG AND W OF HWY 183. USED LOWER
NAM 2M DWPTS WHICH DROPS INTO THE UPR 30S. WINDS LOOK MARGINAL.
FRI: WEAK HIGH PRES BUILDS IN BEFORE SECONDARY COLD FRONTAL
PASSAGE. A BREEZY DAY W OF HWY 281. THERE IS A VERY LOW
PROBABILITY FOR AN ISOLATED SHWR/TSTM IN VICINITY OF THE
APPROACHING FRONT AND THE STALLED FRONT OVER THE SE. FIRE DANGER
COULD BE ELEVATED AGAIN W OF HWY 183.
SAT: BREEZY AND COOL WITH HIGH TEMPS ABOUT 10F COOLER THAN
NORMAL. COULD SEE A FEW SPRINKLES N OF I-80 IN THE AFTN.
SUN: NICE AND COMFORTABLE. A GOOD DAY TO OPEN UP THE HOUSE.
SUN NGT: A STRONG PULSE OF WAA/MSTR TRANSPORT AS 40 KT LLJ
DEVELOPS. MSTR WILL INITIALLY BE LACKING SO IT APPEARS THIS
PROCESS WILL NOT DESTABILIZE THE ATMS. JUST TOO SOON SO THE FCST
IS DRY.
MON-TUE: RISK OF TSTMS INCREASES AND PROBABLY PEAKS TUE. WE ARE
PROBABLY TOO LOW ON OUR TEMPS BY 3-5F. WOULD NOT BE SURPRISED TO SEE
MID 90S SW OF THE TRI-CITIES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 246 PM CDT WED MAY 29 2013
THERE ARE NUMEROUS AVIATION CHALLENGES INCLUDING MULTIPLE ROUNDS
OF THUNDERSTORMS IN AND AROUND KGRI THROUGH THIS EVENING. VARYING
WIND SPEED AND DIRECTION NEAR THUNDERSTORMS WILL ALSO BE A
CONCERN. FURTHERMORE...THERE WILL BE PERIODIC MVFR AND IFR
CONDITIONS DUE TO LOW CLOUDS ASSOCIATED WITH THUNDERSTORMS.
THUNDERSTORMS CONTINUE TO REDEVELOP TO THE SOUTHWEST OF KGRI AND
THESE THUNDERSTORMS WILL SWING THROUGH OR NEAR KGRI THIS
AFTERNOON. ANOTHER INTENSE LINE OF THUNDERSTORMS WILL LIKELY
DEVELOP ACROSS SOUTHWEST NEBRASKA INTO WESTERN KANSAS LATE THIS
AFTERNOON AND WILL PUCH NORTHEAST INTO KGRI THIS EVENING. SEVERE
WEATHER IS POSSIBLE.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...WIND ADVISORY UNTIL 9 PM CDT THIS EVENING FOR KSZ006-007-017>019.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...JCB
LONG TERM...HALBLAUB
AVIATION...027
AREA FORECAST DISCUSSION
NWS HASTINGS NE
808 AM CDT WED MAY 29 2013
.UPDATE...
ISSUED AT 808 AM CDT WED MAY 29 2013
GIVEN INCREASE IN SHOWERS/FAIRLY WEAK THUNDERSTORMS ACROSS MUCH OF
THE SOUTHEAST 1/4 OF THE CWA ALREADY THIS MORNING...HAVE UPPED
POPS TO 50 PERCENT THIS MORNING ACROSS MUCH OF THE EASTERN 1/2 OF
THE CWA...WHILE KEEPING LOWER POPS IN THE WEST. AM NOT
ANTICIPATING SEVERE STORMS THIS MORNING...BUT SOME SMALL HAIL IS
NOT OUT OF THE QUESTION. ITS A COMPLEX CONVECTIVE SCENARIO
TODAY..WITH THE PRESENCE OF SEVERAL SUBTLE DISTURBANCES IN THE MID
LEVEL FLOW OUT AHEAD OF THE PRIMARY SHORTWAVE TROUGH APPROACHING
FROM THE ROCKIES...VERY POSSIBLY ENSURING THAT AT LEAST SOME
PORTION OF THE CWA WILL SEE RAIN AT ANY GIVEN TIME TODAY.
ON ANOTHER NOTE...REGARDING THE THURSDAY/FRIDAY FIRE WEATHER
CONCERNS FOR OUR WESTERN CWA OUTLINED IN THE PREVIOUS
DISCUSSION...UPON FURTHER INSPECTION THE OFFICIAL FIRE WEATHER
FUEL STATUS FOR ALL NEBRASKA ZONES WAS SET TO UNFAVORABLE FOR
LARGE FIRE GROWTH AS OF YESTERDAY. THIS BASICALLY MEANS THAT
VEGETATION IS GREEN ENOUGH/WET ENOUGH TO PRECLUDE MAJOR FIRE
WEATHER PROBLEMS...ALTHOUGH OF COURSE CAUTION SHOULD STILL BE
USED WHEN BURNING. AS A RESULT OF THIS UNFAVORABLE FUEL
STATUS...WILL BE REMOVING ELEVATED FIRE DANGER MENTION FROM THE
HAZARDOUS WEATHER OUTLOOK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 406 AM CDT WED MAY 29 2013
MAIN FORECAST CONCERN WILL BE
CHANCES FOR THUNDERSTORMS.
RADAR FROM KLNX SHOWS THAT MANY OF THE THUNDERSTORMS TO THE WEST
HAVE DIMINISHED BUT A RAIN SHIELD REMAINS. THERE ARE A COUPLE OF
BOUNDARIES THAT ARE SHOWING UP ON KUEX RADAR...ONE FROM THE
CONVECTION TO THE WEST AND ANOTHER FROM CONVECTION TO THE SOUTH.
WHEN THESE COLLIDE APPEARS TO BE THE BEST CHANCE FOR SOME SHOWERS
AND THUNDERSTORMS EARLY THIS MORNING. THERE HAVE BEEN A FEW THAT
GOT STARTED BUT SOON WANED.
MODELS ARE SIMILAR WITH THE UPPER LEVEL LOW THAT MOVES FROM THE
NORTHERN ROCKIES INTO THE NORTHERN HIGH PLAINS TODAY AND TONIGHT.
THERE IS A SURFACE LOW ON THE HIGH PLAINS THAT TRIES TO MOVE
EAST...BUT DOES NOT MAKE IT THROUGH THE AREA. THE SURFACE PRESSURE
GRADIENT TIGHTENS THIS MORNING AHEAD OF THE SURFACE LOW. WINDS
WILL START TO INCREASE. THE STRONGEST WINDS WILL BE IN THE
SOUTHERN PART OF THE FORECAST AREA...BUT BREEZY CONDITIONS ARE
EXPECTED ACROSS THE AREA TODAY. WILL KEEP THE WIND ADVISORY AS IS
FOR NOW.
THE NEXT CONCERN WILL BE WHEN THUNDERSTORMS WILL DEVELOP. THE
UPPER LEVEL WAVE WILL START TO AFFECT THE AREA THIS MORNING AND
SOME THUNDERSTORM DEVELOPMENT IS NOT OUT OF THE QUESTION. THE NAM
AND THE GFS SHOW A DEFINITIVE INCREASE IN QPF DURING THE MORNING
BUT THE RAP AND 4KM WRF BOTH HOLD OFF UNTIL LATER. WILL KEEP SOME
LOW POPS IN FOR THE MORNING...BUT RAMP IT UP LATER THIS MORNING
AND EARLY THIS AFTERNOON WHEN THE UPPER WAVE IS MOVING INTO THE
AREA. SEVERE WEATHER IS EXPECTED DURING THE AFTERNOON AND EVENING
WHEN MUCAPES ARE EXPECTED TO BE OVER 3500 J/KG. THE SEVERE WEATHER
WILL LIKELY CONTINUE INTO THE EVENING BUT THE SEVERE THREAT WILL
DIMINISH LATER TONIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 406 AM CDT WED MAY 29 2013
MAIN STORY: A REPRIEVE FROM THE THREAT OF TSTMS WILL OCCUR AS
TEMPS TUMBLE TO BELOW NORMAL THIS WEEKEND...THEN THE THREAT
RETURNS EARLY NEXT WEEK AS SUMMER WARMTH RETURNS.
ALOFT: THE TROF CURRENTLY MOVING THRU THE W WILL CLOSE OFF OVER
THE NRN PLAINS THU NGT-FRI BEFORE OPENING UP AND SLOWLY MIGRATING
INTO THE GREAT LAKES AND MIDWEST THIS WEEKEND. A MODEST SHRTWV
RIDGE WILL ADVANCE INTO THE PLAINS SUN-MON...AS THE NEXT TROF
MOVES INTO THE PAC NW. ALL THE WHILE THE WESTERLIES WILL GRADUALLY
LIFT BACK INTO THE NRN USA.
SFC: A COOL FRONT WILL MOVE THRU LATE THU AFTN/EVE. HOWEVER...THE
TAIL END OF THE FRONT MAY NOT ENTIRELY CLEAR THE SE FRINGE OF OUR
FCST AREA UNTIL FRI EVNG. THIS FRONT WILL BE FOLLOWED BY A SECONDARY
STRONGER COLD FRONT FRI EVNG. HIGH PRES DRIFTS THRU SUN WITH RETURN
FLOW INTENSIFYING WITH ITS DEPARTURE TO THE E AND REDEVELOPMENT OF
THE LEE TROF...AS LOW PRES HEADS E ALONG THE USA-CAN BORDER. HEAT
BUILDS OVER THE REGION MON-TUE UNTIL THE NEXT COOL FRONT MOVES THRU
TUE NGT OR WED. COOL HIGH PRES THEN BUILDS IN THU.
HAZARDS: FIRE WX MAY BECOME A CONCERN THU/FRI BETWEEN 2PM-8PM.
ATTM DO NOT ENVISION A RFW BUT FIRE DANGER COULD BE ELEVATED.
THERE ARE MULTIPLE CHANCES FOR TSTMS THU-FRI BUT COVERAGE AND
INTENSITY WILL BE LOW DUE TO DIMINISHING MSTR/INSTABILITY. SOME
SVR TSTMS WILL BE POSSIBLE EARLY NEXT WEEK AS INSTABILITY
INCREASES.
THE DAILY DETAILS...
THU: THE BACKSIDE OF AN MCS MAY STILL LINGER SE OF THE TRI-CITIES
IN THE MRNG. OTHERWISE DECREASING CLOUDS.
THE DRYLINE WILL PRESS INTO THE FCST AREA IN THE WARM SECTOR OF A
992 MB SFC LOW OVER THE DAKOTAS...WITH ITS ASSOCIATED COOL FRONT
DROPPING INTO THE NW FRINGE LATE. THE LFQ OF THE 80 KT ULJ WILL BE
OVER THE CNTRL PLAINS...BUT HIGH QUALITY MSTR WILL BE RAPIDLY ON THE
DECREASE. AN ISOLATED SHWR/TSTM IS POSSIBLE...MAINLY E OF HWY 281.
FIRE DANGER: WE NEED TO WATCH ALONG AND W OF HWY 183. USED LOWER
NAM 2M DWPTS WHICH DROPS INTO THE UPR 30S. WINDS LOOK MARGINAL.
FRI: WEAK HIGH PRES BUILDS IN BEFORE SECONDARY COLD FRONTAL
PASSAGE. A BREEZY DAY W OF HWY 281. THERE IS A VERY LOW
PROBABILITY FOR AN ISOLATED SHWR/TSTM IN VICINITY OF THE
APPROACHING FRONT AND THE STALLED FRONT OVER THE SE. FIRE DANGER
COULD BE ELEVATED AGAIN W OF HWY 183.
SAT: BREEZY AND COOL WITH HIGH TEMPS ABOUT 10F COOLER THAN
NORMAL. COULD SEE A FEW SPRINKLES N OF I-80 IN THE AFTN.
SUN: NICE AND COMFORTABLE. A GOOD DAY TO OPEN UP THE HOUSE.
SUN NGT: A STRONG PULSE OF WAA/MSTR TRANSPORT AS 40 KT LLJ
DEVELOPS. MSTR WILL INITIALLY BE LACKING SO IT APPEARS THIS
PROCESS WILL NOT DESTABILIZE THE ATMS. JUST TOO SOON SO THE FCST
IS DRY.
MON-TUE: RISK OF TSTMS INCREASES AND PROBABLY PEAKS TUE. WE ARE
PROBABLY TOO LOW ON OUR TEMPS BY 3-5F. WOULD NOT BE SURPRISED TO SEE
MID 90S SW OF THE TRI-CITIES.
&&
.AVIATION...(FOR THE 12Z KGRI TAF THROUGH 12Z THURSDAY MORNING)
ISSUED AT 555 AM CDT WED MAY 29 2013
LOWER CLOUDS ARE MOVING INTO THE KGRI TERMINAL AREA THIS MORNING.
THEY SHOULD BE MAINLY MVFR THROUGH MUCH OF THE DAY. WINDS WILL
INCREASE DURING THE MORNING AND BE BREEZY DURING THE AFTERNOON AND
INTO THE EVENING. THERE ARE CHANCES FOR SOME THUNDER MUCH OF THE
DAY BUT TRIED TO DEFINE THE MOST LIKELY TIMES. THE FIRST ROUND
SHOULD BE DURING THE AFTERNOON INTO THE EVENING WITH A BETTER
CHANCE LATER TONIGHT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...WIND ADVISORY UNTIL 9 PM CDT THIS EVENING FOR KSZ006-007-017>019.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...JCB
LONG TERM...HALBLAUB
AVIATION...JCB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
556 AM CDT WED MAY 29 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 406 AM CDT WED MAY 29 2013
MAIN FORECAST CONCERN WILL BE
CHANCES FOR THUNDERSTORMS.
RADAR FROM KLNX SHOWS THAT MANY OF THE THUNDERSTORMS TO THE WEST
HAVE DIMINISHED BUT A RAIN SHIELD REMAINS. THERE ARE A COUPLE OF
BOUNDARIES THAT ARE SHOWING UP ON KUEX RADAR...ONE FROM THE
CONVECTION TO THE WEST AND ANOTHER FROM CONVECTION TO THE SOUTH.
WHEN THESE COLLIDE APPEARS TO BE THE BEST CHANCE FOR SOME SHOWERS
AND THUNDERSTORMS EARLY THIS MORNING. THERE HAVE BEEN A FEW THAT
GOT STARTED BUT SOON WANED.
MODELS ARE SIMILAR WITH THE UPPER LEVEL LOW THAT MOVES FROM THE
NORTHERN ROCKIES INTO THE NORTHERN HIGH PLAINS TODAY AND TONIGHT.
THERE IS A SURFACE LOW ON THE HIGH PLAINS THAT TRIES TO MOVE
EAST...BUT DOES NOT MAKE IT THROUGH THE AREA. THE SURFACE PRESSURE
GRADIENT TIGHTENS THIS MORNING AHEAD OF THE SURFACE LOW. WINDS
WILL START TO INCREASE. THE STRONGEST WINDS WILL BE IN THE
SOUTHERN PART OF THE FORECAST AREA...BUT BREEZY CONDITIONS ARE
EXPECTED ACROSS THE AREA TODAY. WILL KEEP THE WIND ADVISORY AS IS
FOR NOW.
THE NEXT CONCERN WILL BE WHEN THUNDERSTORMS WILL DEVELOP. THE
UPPER LEVEL WAVE WILL START TO AFFECT THE AREA THIS MORNING AND
SOME THUNDERSTORM DEVELOPMENT IS NOT OUT OF THE QUESTION. THE NAM
AND THE GFS SHOW A DEFINITIVE INCREASE IN QPF DURING THE MORNING
BUT THE RAP AND 4KM WRF BOTH HOLD OFF UNTIL LATER. WILL KEEP SOME
LOW POPS IN FOR THE MORNING...BUT RAMP IT UP LATER THIS MORNING
AND EARLY THIS AFTERNOON WHEN THE UPPER WAVE IS MOVING INTO THE
AREA. SEVERE WEATHER IS EXPECTED DURING THE AFTERNOON AND EVENING
WHEN MUCAPES ARE EXPECTED TO BE OVER 3500 J/KG. THE SEVERE WEATHER
WILL LIKELY CONTINUE INTO THE EVENING BUT THE SEVERE THREAT WILL
DIMINISH LATER TONIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 406 AM CDT WED MAY 29 2013
MAIN STORY: A REPRIEVE FROM THE THREAT OF TSTMS WILL OCCUR AS
TEMPS TUMBLE TO BELOW NORMAL THIS WEEKEND...THEN THE THREAT
RETURNS EARLY NEXT WEEK AS SUMMER WARMTH RETURNS.
ALOFT: THE TROF CURRENTLY MOVING THRU THE W WILL CLOSE OFF OVER
THE NRN PLAINS THU NGT-FRI BEFORE OPENING UP AND SLOWLY MIGRATING
INTO THE GREAT LAKES AND MIDWEST THIS WEEKEND. A MODEST SHRTWV
RIDGE WILL ADVANCE INTO THE PLAINS SUN-MON...AS THE NEXT TROF
MOVES INTO THE PAC NW. ALL THE WHILE THE WESTERLIES WILL GRADUALLY
LIFT BACK INTO THE NRN USA.
SFC: A COOL FRONT WILL MOVE THRU LATE THU AFTN/EVE. HOWEVER...THE
TAIL END OF THE FRONT MAY NOT ENTIRELY CLEAR THE SE FRINGE OF OUR
FCST AREA UNTIL FRI EVNG. THIS FRONT WILL BE FOLLOWED BY A SECONDARY
STRONGER COLD FRONT FRI EVNG. HIGH PRES DRIFTS THRU SUN WITH RETURN
FLOW INTENSIFYING WITH ITS DEPARTURE TO THE E AND REDEVELOPMENT OF
THE LEE TROF...AS LOW PRES HEADS E ALONG THE USA-CAN BORDER. HEAT
BUILDS OVER THE REGION MON-TUE UNTIL THE NEXT COOL FRONT MOVES THRU
TUE NGT OR WED. COOL HIGH PRES THEN BUILDS IN THU.
HAZARDS: FIRE WX MAY BECOME A CONCERN THU/FRI BETWEEN 2PM-8PM.
ATTM DO NOT ENVISION A RFW BUT FIRE DANGER COULD BE ELEVATED.
THERE ARE MULTIPLE CHANCES FOR TSTMS THU-FRI BUT COVERAGE AND
INTENSITY WILL BE LOW DUE TO DIMINISHING MSTR/INSTABILITY. SOME
SVR TSTMS WILL BE POSSIBLE EARLY NEXT WEEK AS INSTABILITY
INCREASES.
THE DAILY DETAILS...
THU: THE BACKSIDE OF AN MCS MAY STILL LINGER SE OF THE TRI-CITIES
IN THE MRNG. OTHERWISE DECREASING CLOUDS.
THE DRYLINE WILL PRESS INTO THE FCST AREA IN THE WARM SECTOR OF A
992 MB SFC LOW OVER THE DAKOTAS...WITH ITS ASSOCIATED COOL FRONT
DROPPING INTO THE NW FRINGE LATE. THE LFQ OF THE 80 KT ULJ WILL BE
OVER THE CNTRL PLAINS...BUT HIGH QUALITY MSTR WILL BE RAPIDLY ON THE
DECREASE. AN ISOLATED SHWR/TSTM IS POSSIBLE...MAINLY E OF HWY 281.
FIRE DANGER: WE NEED TO WATCH ALONG AND W OF HWY 183. USED LOWER
NAM 2M DWPTS WHICH DROPS INTO THE UPR 30S. WINDS LOOK MARGINAL.
FRI: WEAK HIGH PRES BUILDS IN BEFORE SECONDARY COLD FRONTAL
PASSAGE. A BREEZY DAY W OF HWY 281. THERE IS A VERY LOW
PROBABILITY FOR AN ISOLATED SHWR/TSTM IN VICINITY OF THE
APPROACHING FRONT AND THE STALLED FRONT OVER THE SE. FIRE DANGER
COULD BE ELEVATED AGAIN W OF HWY 183.
SAT: BREEZY AND COOL WITH HIGH TEMPS ABOUT 10F COOLER THAN
NORMAL. COULD SEE A FEW SPRINKLES N OF I-80 IN THE AFTN.
SUN: NICE AND COMFORTABLE. A GOOD DAY TO OPEN UP THE HOUSE.
SUN NGT: A STRONG PULSE OF WAA/MSTR TRANSPORT AS 40 KT LLJ
DEVELOPS. MSTR WILL INITIALLY BE LACKING SO IT APPEARS THIS
PROCESS WILL NOT DESTABILIZE THE ATMS. JUST TOO SOON SO THE FCST
IS DRY.
MON-TUE: RISK OF TSTMS INCREASES AND PROBABLY PEAKS TUE. WE ARE
PROBABLY TOO LOW ON OUR TEMPS BY 3-5F. WOULD NOT BE SURPRISED TO SEE
MID 90S SW OF THE TRI-CITIES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 555 AM CDT WED MAY 29 2013
LOWER CLOUDS ARE MOVING INTO THE KGRI TERMINAL AREA THIS MORNING.
THEY SHOULD BE MAINLY MVFR THROUGH MUCH OF THE DAY. WINDS WILL
INCREASE DURING THE MORNING AND BE BREEZY DURING THE AFTERNOON AND
INTO THE EVENING. THERE ARE CHANCES FOR SOME THUNDER MUCH OF THE
DAY BUT TRIED TO DEFINE THE MOST LIKELY TIMES. THE FIRST ROUND
SHOULD BE DURING THE AFTERNOON INTO THE EVENING WITH A BETTER
CHANCE LATER TONIGHT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...WIND ADVISORY FROM 10 AM THIS MORNING TO 9 PM CDT THIS EVENING
FOR KSZ006-007-017>019.
&&
$$
SHORT TERM...JCB
LONG TERM...HALBLAUB
AVIATION...JCB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
407 AM CDT WED MAY 29 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 406 AM CDT WED MAY 29 2013
MAIN FORECAST CONCERN WILL BE
CHANCES FOR THUNDERSTORMS.
RADAR FROM KLNX SHOWS THAT MANY OF THE THUNDERSTORMS TO THE WEST
HAVE DIMINISHED BUT A RAIN SHIELD REMAINS. THERE ARE A COUPLE OF
BOUNDARIES THAT ARE SHOWING UP ON KUEX RADAR...ONE FROM THE
CONVECTION TO THE WEST AND ANOTHER FROM CONVECTION TO THE SOUTH.
WHEN THESE COLLIDE APPEARS TO BE THE BEST CHANCE FOR SOME SHOWERS
AND THUNDERSTORMS EARLY THIS MORNING. THERE HAVE BEEN A FEW THAT
GOT STARTED BUT SOON WANED.
MODELS ARE SIMILAR WITH THE UPPER LEVEL LOW THAT MOVES FROM THE
NORTHERN ROCKIES INTO THE NORTHERN HIGH PLAINS TODAY AND TONIGHT.
THERE IS A SURFACE LOW ON THE HIGH PLAINS THAT TRIES TO MOVE
EAST...BUT DOES NOT MAKE IT THROUGH THE AREA. THE SURFACE PRESSURE
GRADIENT TIGHTENS THIS MORNING AHEAD OF THE SURFACE LOW. WINDS
WILL START TO INCREASE. THE STRONGEST WINDS WILL BE IN THE
SOUTHERN PART OF THE FORECAST AREA...BUT BREEZY CONDITIONS ARE
EXPECTED ACROSS THE AREA TODAY. WILL KEEP THE WIND ADVISORY AS IS
FOR NOW.
THE NEXT CONCERN WILL BE WHEN THUNDERSTORMS WILL DEVELOP. THE
UPPER LEVEL WAVE WILL START TO AFFECT THE AREA THIS MORNING AND
SOME THUNDERSTORM DEVELOPMENT IS NOT OUT OF THE QUESTION. THE NAM
AND THE GFS SHOW A DEFINITIVE INCREASE IN QPF DURING THE MORNING
BUT THE RAP AND 4KM WRF BOTH HOLD OFF UNTIL LATER. WILL KEEP SOME
LOW POPS IN FOR THE MORNING...BUT RAMP IT UP LATER THIS MORNING
AND EARLY THIS AFTERNOON WHEN THE UPPER WAVE IS MOVING INTO THE
AREA. SEVERE WEATHER IS EXPECTED DURING THE AFTERNOON AND EVENING
WHEN MUCAPES ARE EXPECTED TO BE OVER 3500 J/KG. THE SEVERE WEATHER
WILL LIKELY CONTINUE INTO THE EVENING BUT THE SEVERE THREAT WILL
DIMINISH LATER TONIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 406 AM CDT WED MAY 29 2013
MAIN STORY: A REPRIEVE FROM THE THREAT OF TSTMS WILL OCCUR AS
TEMPS TUMBLE TO BELOW NORMAL THIS WEEKEND...THEN THE THREAT
RETURNS EARLY NEXT WEEK AS SUMMER WARMTH RETURNS.
ALOFT: THE TROF CURRENTLY MOVING THRU THE W WILL CLOSE OFF OVER
THE NRN PLAINS THU NGT-FRI BEFORE OPENING UP AND SLOWLY MIGRATING
INTO THE GREAT LAKES AND MIDWEST THIS WEEKEND. A MODEST SHRTWV
RIDGE WILL ADVANCE INTO THE PLAINS SUN-MON...AS THE NEXT TROF
MOVES INTO THE PAC NW. ALL THE WHILE THE WESTERLIES WILL GRADUALLY
LIFT BACK INTO THE NRN USA.
SFC: A COOL FRONT WILL MOVE THRU LATE THU AFTN/EVE. HOWEVER...THE
TAIL END OF THE FRONT MAY NOT ENTIRELY CLEAR THE SE FRINGE OF OUR
FCST AREA UNTIL FRI EVNG. THIS FRONT WILL BE FOLLOWED BY A SECONDARY
STRONGER COLD FRONT FRI EVNG. HIGH PRES DRIFTS THRU SUN WITH RETURN
FLOW INTENSIFYING WITH ITS DEPARTURE TO THE E AND REDEVELOPMENT OF
THE LEE TROF...AS LOW PRES HEADS E ALONG THE USA-CAN BORDER. HEAT
BUILDS OVER THE REGION MON-TUE UNTIL THE NEXT COOL FRONT MOVES THRU
TUE NGT OR WED. COOL HIGH PRES THEN BUILDS IN THU.
HAZARDS: FIRE WX MAY BECOME A CONCERN THU/FRI BETWEEN 2PM-8PM.
ATTM DO NOT ENVISION A RFW BUT FIRE DANGER COULD BE ELEVATED.
THERE ARE MULTIPLE CHANCES FOR TSTMS THU-FRI BUT COVERAGE AND
INTENSITY WILL BE LOW DUE TO DIMINISHING MSTR/INSTABILITY. SOME
SVR TSTMS WILL BE POSSIBLE EARLY NEXT WEEK AS INSTABILITY
INCREASES.
THE DAILY DETAILS...
THU: THE BACKSIDE OF AN MCS MAY STILL LINGER SE OF THE TRI-CITIES
IN THE MRNG. OTHERWISE DECREASING CLOUDS.
THE DRYLINE WILL PRESS INTO THE FCST AREA IN THE WARM SECTOR OF A
992 MB SFC LOW OVER THE DAKOTAS...WITH ITS ASSOCIATED COOL FRONT
DROPPING INTO THE NW FRINGE LATE. THE LFQ OF THE 80 KT ULJ WILL BE
OVER THE CNTRL PLAINS...BUT HIGH QUALITY MSTR WILL BE RAPIDLY ON THE
DECREASE. AN ISOLATED SHWR/TSTM IS POSSIBLE...MAINLY E OF HWY 281.
FIRE DANGER: WE NEED TO WATCH ALONG AND W OF HWY 183. USED LOWER
NAM 2M DWPTS WHICH DROPS INTO THE UPR 30S. WINDS LOOK MARGINAL.
FRI: WEAK HIGH PRES BUILDS IN BEFORE SECONDARY COLD FRONTAL
PASSAGE. A BREEZY DAY W OF HWY 281. THERE IS A VERY LOW
PROBABILITY FOR AN ISOLATED SHWR/TSTM IN VICINITY OF THE
APPROACHING FRONT AND THE STALLED FRONT OVER THE SE. FIRE DANGER
COULD BE ELEVATED AGAIN W OF HWY 183.
SAT: BREEZY AND COOL WITH HIGH TEMPS ABOUT 10F COOLER THAN
NORMAL. COULD SEE A FEW SPRINKLES N OF I-80 IN THE AFTN.
SUN: NICE AND COMFORTABLE. A GOOD DAY TO OPEN UP THE HOUSE.
SUN NGT: A STRONG PULSE OF WAA/MSTR TRANSPORT AS 40 KT LLJ
DEVELOPS. MSTR WILL INITIALLY BE LACKING SO IT APPEARS THIS
PROCESS WILL NOT DESTABILIZE THE ATMS. JUST TOO SOON SO THE FCST
IS DRY.
MON-TUE: RISK OF TSTMS INCREASES AND PROBABLY PEAKS TUE. WE ARE
PROBABLY TOO LOW ON OUR TEMPS BY 3-5F. WOULD NOT BE SURPRISED TO SEE
MID 90S SW OF THE TRI-CITIES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1223 AM CDT WED MAY 29 2013
THUNDERSTORMS TO THE WEST WILL EVENTUALLY MOVE INTO THE KGRI
TERMINAL AREA. WITH THE THUNDERSTORMS THERE ARE SOME LOWER
CEILINGS AND VISIBILITIES AS WELL. THE LOWER CLOUDS WILL LINGER
ACROSS THE AREA THROUGH MUCH OF THE DAY. THE AFTERNOON AND EVENING
WILL BRING ANOTHER CHANCE FOR SOME THUNDERSTORMS. THE FIRST
ROUND SHOULD BE DURING THE AFTERNOON WITH A SMALL BREAK POSSIBLE
FOR A WHILE. MORE THUNDERSTORMS WILL LIKELY MOVE INTO THE KGRI
TERMINAL AREA AT THE VERY END OF THE PERIOD. THERE ARE CHANCES FOR
SOME THUNDERSTORMS THROUGH MUCH IF NOT ALL OF THE PERIOD AND TRIED
TO PICK THE MOST LIKELY TIMING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...WIND ADVISORY FROM 10 AM THIS MORNING TO 9 PM CDT THIS EVENING
FOR KSZ006-007-017>019.
&&
$$
SHORT TERM...JCB
LONG TERM...HALBLAUB
AVIATION...JCB
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1205 AM CDT WED MAY 29 2013
.AVIATION...
06Z TAFS FOR KOFK...KOMA AND KLNK.
LATEST 88D MOSAIC LOOP WAS SHOWING LINE OF TSRA EXTENDING FROMS-CNTRL
SD THRU THE NEB PANHANDLE. EXPECT COMPLEX WILL BEGIN FALLING APART
OVER THE NEXT SEVERAL HOURS AS IT MOVES EAST. OTHERWISE...INFLUX
OF LLVL MOISTURE WILL CONTINUE THRU THE REST OF TONIGHT RESULT IN
CONDITIONS DETERIORATING FROM VFR TO IFR OVER ERN NEB THRU THE
MORNING HOURS. MVFR/IFR CIGS WILL LIKELY PREVAIL AT ALL TAF SITES
THEN UNTIL LATE WED MORNING. BY WED AFTN...EXPECT THE NEXT ROUND
OF TSRA ACTIVITY ACROSS ERN NEB. THUS HAVE OPTED TO INCLUDE PROB30
GROUPS FROM LATE AFTN TO LATE EVENING.
DEE
PREV DISCUSSION... /ISSUED 249 PM CDT TUE MAY 28 2013/
DISCUSSION...
CONVECTION/POSSIBLE FLOODING THROUGH THURSDAY REMAINS PRIMARY
CONCERN.
SUBJECTIVELY PLACED QUASI-STATIONARY FRONT EXTENDED FROM FAR SERN
NEBR INTO SWRN IA AT 19Z WITH CU FIELD THICKENING NEAR/SOUTH OF
IT...ALTHOUGH VIEW SOMEWHAT HINDERED BY HIGHER CLOUDS. ALTHOUGH
FIRST AREA OF CONVECTION WAS DEVELOPING SE OF THE REGION...AND
LEADS SOME SMALL DOUBTS TO WHAT MAY HAPPEN FARTHER NW...VARIOUS
MODEL QPF INCLUDING RAP/HRRR AND 4KM WRF DVLP PRECIP OVER SERN
ZONES THROUGH EARLY EVENING. THIS LOOKS REASONABLE GIVE LATEST SPC
RUC MESO ANALYSIS PAGE SHOWED SRN ZONES ON EDGE OF ML CAPE AXIS OF
3000-4000 J/KG WITH WEAKENED/NO CAP. LOW LEVEL/DEEPER SHEAR
FAVORABLE FOR SEVERE WEATHER...SEE LATEST WATCH/MCD FOR INFO ON
THIS. SINCE SRN ZONES RECEIVED 1-2+ INCHES OF RAIN LAST EVENING...
RIVERS/STREAMS ARE RUNNING HIGH OR CLOSE TO FLOODING IN SOME
CASES. WITH FFG VALUES UNDER 2 INCHES...OPTED TO ISSUE A FLASH
FLOOD WATCH SERN COUNTIES THROUGH TONIGHT. EXTENDED WATCH TO NEBR
CITY/4 SW IA COUNTIES IN CASE STRENGTHENING LOW LEVEL JET ALLOWS
ACTIVITY TO SPREAD/DEVELOP N LATER THIS EVENING...BUT IT WAS NOTED
THAT 4KM WRF AND HRRR DROPPED CONVECTION SE THRU EARLY EVENING.
OTHERWISE ADJUSTED POPS NRN ZONES TONIGHT TO REFLECT BETTER
CHANCES LATER TONIGHT AS LOW LEVEL JET STRENGTHENS N ACROSS THE
AREA CLOSER TO AND AFTER 06Z.
DIURNALLY DECREASED POPS THRU MIDDAY WEDNESDAY BEFORE STRONGER
UPPER TROUGH BEGINS CRASHING UPPER HGTS INTO CNTRL NEBR. THIS
COULD ALLOW A LITTLE EARLIER CONVECTIVE DEVELOPMENT...IF IT EVEN
DECREASES...AND COULD ALSO SET THE STAGE FOR A SEVERE WEATHER AND
HEAVY RAIN THREAT OVER A LARGER PART OF THE FORECAST AREA. WITH
TRAINING POSSIBLE AS UPPER FLOW BECOMES MORE PARALLEL TO MEAN
SHEAR VECTORS THRU WED EVENING...TRAINING OF ECHOES COULD ADD TO
FLOODING POTENTIAL. THIS MAY NECESSITATE A FLASH FLOOD WATCH OVER
A LARGER PART OF THE AREA FOR LATE WED/WED NIGHT IN LATER
FORECASTS...BUT FOR NOW FIRST FLASH FLOOD WATCH WILL ADDRESS
SHORTER TERM FLOODING THREAT.
ACTIVE WEATHER COULD PERSIST INTO THURSDAY AS JET WRAPS ACROSS
SRN ZONES ON SOUTH END OF CLOSING UPPER LOW. QUESTION WILL THEN
SHIFT TO AMOUNT OF RESIDUAL MOISTURE THAT WILL REMAIN OVER AREA AS
UPPER TEMPS COOL BUT SURFACE WINDS TAKE ON A MORE WRLY...
DOWNSLOPE...COMPONENT. FOR NOW MADE LITTLE/NO CHANGES TO PREVIOUS
FORECAST POPS...WHICH WERE FAIRLY HIGH YET THROUGH THU
EVENING...BUT LOWERED LATE THU NGT. NO CHANGES MADE TO MODEST POPS
FRIDAY OR REST OF MODEL/PRIOR FORECAST BLEND REST OF FORECAST.
SOME POTENTIAL FOR TEMPERATURES TO REALLY WARM TOMORROW AS SRLY
WINDS INCREASE AHEAD OF TROUGH AND WITH WRLY COMPONENT TO SURFACE
WINDS ON THURSDAY. HOWEVER...WITH RISK/UNCERTAINTY OF RESIDUAL
CLOUDS AND OR TSTMS...OPTED FOR LITTLE CHANGE FROM PREVIOUS
FORECAST WHICH WAS FAIRLY ALIGNED WITH GUIDANCE.
CHERMOK
HYDROLOGY...UPDATED AT 110 PM CDT...
FOR INFO ON FLASH FLOOD WATCH SEE ABOVE. OTHERWISE FLOOD WARNING
CONTINUES FOR TURKEY CREEK AT WILBER. THOUGH IT HAS CRESTED AND
STARTED FALLING FOR NOW...IT IS FORECAST TO RISE AGAIN LATER
TONIGHT AND WEDNESDAY. THE LITTLE AND BIG NEMAHA RIVERS IN
SOUTHEAST NEBRASKA DID RISE TO JUST BELOW FLOOD STAGE BUT HAVE
SINCE STARTED TO DECLINE. WARNINGS ALSO CONTINUE FOR THE MISSOURI
RIVER FROM PLATTSMOUTH DOWNSTREAM TO RULO FOR SIGNIFICANT RISES
OVER THE NEXT FEW DAYS. OMAHA ON THE MISSOURI RIVER IS FORECAST TO
RISE...BUT REMAIN JUST BELOW FLOOD LEVELS BUT WILL EVENTUALLY NEED
A FLOOD ADVISORY. THE NISHNABOTNA RIVER BASIN DID ALSO SEE
SIGNIFICANT IN BANK RISES...BUT REMAINED BELOW FLOOD STAGE AND
HAVE STARTED TO FALL. A FLOOD WARNING WAS ISSUED ON THE LITTLE
SIOUX RIVER NEAR TURIN AS IT IS FORECAST TO GO ABOUT TWO FEET
ABOVE FLOOD STAGE BY FRIDAY.
MEYER
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
99/99
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1013 PM CDT THU MAY 30 2013
.UPDATE...
ISSUED AT 1008 PM CDT THU MAY 30 2013
LITTLE CHANGES MADE. SHORT WAVE MOVING NOW THROUGH THE MID
MISSOURI RIVER VALLEY NR OMAHA-SIOUX CITY IS SPARKING SOME MORE
NUMEROUS STORMS FROM SE SOUTH DAKOTA INTO WRN IA AND IDEA IS STILL
THERE FROM LATEST RAP THAT RAINFALL WILL INCREASE AGAIN WITH THIS
WAVE AS IT MOVES UP TOWARD BEMIDJI AREA FRIDAY MORNING THEN BACK
WEST INTO NORTH CENTRAL ND FRIDAY DAY AS UPPER LOW MOVES-REFORMS A
BIT EAST OF CURRENT LOCATION. SO KEEPING SCT SHRA/TSTM IN FCST
TONIGHT WITH LIKELY POPS IN THE FAR NORTH.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 312 PM CDT THU MAY 30 2013
CURRENT RADAR SHOWS MAIN BAND OF RAIN SHOWERS ACROSS NORTHWESTERN
HALF OF STATE WITH MORE DEVELOPMENT ALONG FRONTAL BOUNDARY JUST
NORTH OF THE HWY 2 CORRIDOR. WARMEST TEMPS OF 72 PLUS OVER
MAJORITY OF SOUTHERN VALLEY AND SOUTHEASTERN COUNTIES...WHERE
WE HAVE SEEN SOME SOLAR THROUGHOUT LAST HALF OF THE DAY. GENERAL
PREFERENCE FOR CURRENT PRECIP TRENDS IS A NAM/RUC/HRRR BLEND.
TONIGHT...NAM 3-HOUR PWAT CHANGE PRODUCT HAS HAD A DECENT HANDLE
ON TRENDS OF WAVES OF PRECIP WHICH MOVED THROUGH TODAY. SHOWS
DECREASING MOISTURE OVER EASTERN AND NORTHEASTERN ZONES FOR SECOND
HALF OF AFTN WITH PWATS INCREASING ACROSS WARM SECTOR AFT 00Z. AT
THIS POINT NAM SHOWS DECREASING SHOWALTERS TO ABOUT NEG 2...WHILE
GFS KEEPS LOWEST SHOWALTERS AROUND 0. WEAK TO MODEST CAPE AROUND
500 TO 1000 J/KG OFF SPC MESOANALYSIS PAGE...ENOUGH TO INITIATE
SOME CONVECTION ALONG WARM FRONTAL BNDRY. 0 TO 6 KM BULK SHEAR IS
WEAK...HOWEVER...THUS THINK THE THREAT OF SEVERE IS LOW BUT HEAVY
SHOWERS BEING BIGGEST CONCERN GIVEN AMOUNT OF PRECIP OVER THE
REGION THE LAST COUPLE OF WEEKS...ESPECIALLY IN THE FARGO/MOORHEAD
AREA WHERE 5 PLUS INCHES FELL OVERNIGHT LAST NIGHT (BUFFALO RIVER
BASIN EAST OF FARGO). BY 06Z CAPES ERODE AND SHOWALTERS BEGIN TO
INCREASE...AND ANY PRECIP SHOULD BE MORE SHOWERS THAN
THUNDERSTORMS. DO EXPECT ANOTHER BREAK TONIGHT AS SHORT WAVE
ROTATING AROUND UPPER LOW SHOULD PASS THROUGH AROUND 06Z.
TOMORROW AND TOMORROW NIGHT...UPPER LOW WILL BEGIN TO SHIFT
EASTWARD WITH ASSOCIATED WAVES ROTATING AROUND LOW...WHICH WILL
RESULT IN MORE BANDS OF RAIN SHOWERS MOVING ACROSS REGION...WITH
EASTERN NORTH DAKOTA BEING IN THE MOST LIKELY REGION TO RECEIVE
PRECIP. THIS THREAT AREA WILL SLOWLY SHIFT EAST AS THE LOW PULLS
EAST FRIDAY AND SATURDAY.
AT THE CURRENT TIME DO NOT SEE ANY HEAVY BANDS OF RAIN AS WE
ENCOUNTERED LAST NIGHT...ALTHOUGH WITH A CHANCE FOR CONVECTION
TONIGHT...LOCAL AREAS COULD RECEIVE AN INCH OR MORE. GIVEN
LOCATION OF WARM FRONT...THIS WOULD LIKELY BE NORTH OF CLAY COUNTY
AREA TONIGHT BUT COULD BE AN ISSUE AS UPPER LOW SHIFTS EAST ON
FRI/SAT...SO AREA NEEDS CONTINUED MONITORING AS AN AREAL FLOOD
WARNING IS STILL IN EFFECT FOR CLAY COUNTY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 312 PM CDT THU MAY 30 2013
THE UPPER TROUGH THAT HAS BROUGHT THE UNSETTLED WEATHER DURING THE
LATER PART OF THE WORK WEEK WILL BEGIN TO MOVE OFF INTO THE GREAT
LAKES SATURDAY. THERE COULD BE SOME LINGERING RAIN SHOWERS AND
BREEZY NORTHWEST WINDS ON THE BACKSIDE OF THE SFC LOW SATURDAY
MORNING...BUT CONDITIONS WILL IMPROVE LATER IN THE DAY AND THINGS
SHOULD BE PRETTY QUIET FOR SUNDAY WITH HIGH PRESSURE BUILDING INTO
THE NORTHERN PLAINS. TEMPS WILL BE FAIRLY COOL OVER THE WEEKEND
WITH HIGHS IN THE UPPER 50S AND 60S AND LOWS MAINLY IN THE 40S.
MONDAY THROUGH THURSDAY...THE BREAK IN THE ACTIVE WEATHER WILL BE
FAIRLY SHORT FROM SUNDAY INTO EARLY MONDAY. MODELS ARE IN FAIRLY
DECENT AGREEMENT ON ANOTHER UPPER LOW APPROACHING THE AREA...THIS
TIME ON A MORE NORTHERLY TRACK ACROSS MONTANA INTO THE NORTHERN
PLAINS. THERE ARE SOME DIFFERENCES IN THE EXACT HANDLING OF THE
LOW...WITH THE GFS SLIGHTLY MORE PROGRESSIVE THAN THE OTHER
DETERMINISTIC MODELS. HOWEVER...THEY ARE IN PRETTY DECENT AGREEMENT
ON BRINGING MORE PRECIP TO THE CWA BEGINNING MONDAY AFTERNOON AND
CONTINUING THROUGH THE MIDDLE OF NEXT WEEK. EVEN INTO THURSDAY AS
THE MAIN UPPER LOW BEGINS TO PULL AWAY THE MODELS HAVE PRECIP
REDEVELOPING UNDER THE MID LEVEL COLD POOL. STARTED POPS IN THE FAR
WEST MONDAY AND CONTINUED WITH FAIRLY HIGH VALUES THROUGH TUESDAY
AND WEDNESDAY. WITH CLOUDS AND PRECIP THERE WILL NOT BE MUCH DIURNAL
RANGE IN TEMPERATURES. ALLBLEND GIVES HIGHS IN THE MID 60S AND LOWS
IN THE LOW 50S WHICH SEEMS REASONABLE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 709 PM CDT THU MAY 30 2013
SFC LOW AROUND HETTINGER ND WITH A WARM FRONT THRU HAZEN ND TO
CARRINGTON-NEW ROCKFORD TO GRAND FORKS-THIEF RIVER FALLS-WASKISH.
SOUTH OF WARM FRONT SOUTH-SOUTHEAST WINDS AND VFR CLOUDS WITH
CLOUD BASES WELL ABOVE 6K FT. EXPECT THIS TO CONTINUE INTO THE
OVERNIGHT GFK-FAR-BJI AREAS WITH SOME CHANCES OF MVFR CLOUDS LATE
TONIGHT INTO FRIDAY DUE TO SATURATION. DVL REGION VFR NOW BUT
CLOSE TO MVFR DECK TO THE NORTHWEST AND THUS BROUGHT MVFR CLOUDS
IN FASTER. KEPT SHOWER THREAT RATHER LOW IN TAFS UNTIL LATE
TONIGHT OR FRIDAY BUT FARGO AREA ITSELF MAY NOT SEE TOO MUCH TIL
LATE FRIDAY. WINDS WILL TURN BACK TO MORE EAST OR NORTHEAST FRI
AFTN AND WILL GET A BIT GUSTY ESP DVL REGION.
&&
.HYDROLOGY...
ISSUED AT 1013 PM CDT THU MAY 30 2013
.HYDROLOGY...
THE AREAL FLOOD WARNING FOR NORTHERN CLAY COUNTY HAS BEEN ALLOWED TO
EXPIRE. RELATIVELY LITTLE RAIN HAS OCCURRED SINCE THE EARLY MORNING
HOURS...ALLOWING CONDITIONS TO IMPROVE.
RIVER FLOOD WARNINGS REMAIN IN EFFECT ON THE BUFFALO RIVER NEAR
DILWORTH AND ON THE WILD RICE RIVER NEAR HENDRUM...RESULTING FROM
RUNOFF FROM LOCALIZED HEAVY RAINFALL ACROSS PARTS OF NORMAN AND CLAY
COUNTIES LAST NIGHT. OTHERWISE A FEW LOCATIONS ALONG THE MAINSTEM RED
AND AREA TRIBUTARIES ARE ABOVE OR ARE EXPECTED TO RISE ABOVE ACTION
STAGE...BUT REMAIN BELOW FLOOD STAGE. ADDITIONAL RAINFALL TONIGHT
THROUGH SATURDAY IS NOT CURRENTLY EXPECTED TO SIGNIFICANTLY AFFECT
AREA RIVER LEVELS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...SPEICHER
LONG TERM...JR
AVIATION...RIDDLE
HYDROLOGY...MAKOWSKI
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
732 AM EDT WED MAY 29 2013
.SYNOPSIS...
DRY ATLANTIC HIGH PRESSURE WILL DOMINATE OUR WEATHER THROUGH THE
WORK WEEK. THE HIGH WILL MOVE OFF THE EAST COAST OVER THE
WEEKEND...AS A WEAK COLD FRONT PUSHES INTO THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 615 AM EDT WEDNESDAY...STRATUS HAS STARTED TO DEVELOP OVER NRN
GA AND THE SC MIDLANDS. BASED ON THE ORIENTATION OF THE LLVL
FLOW...I THINK THAT THE UPPER SAVANNAH RIVER VALLEY MAY SEE SOME
STRATUS IN AN HOUR OR TWO AND I/VE UPPED CLOUD COVER THERE.
HOWEVER...THE LLVL FLOW IS QUITE WEAK AND I DON/T EXPECT THE LOW
CLOUDS TO EXPAND EAST OF ANDERSON OR AS FAR NORTH AS CHARLOTTE. AT
LEAST NOT UNTIL WE START TO MIX AND THEN CLOUDS WILL DEVELOP AS A
HIGHER CELLULAR CU DECK.
AS OF 245 AM EDT WEDNESDAY...STRATO-CU CONTINUES TO DEVELOP IN THE
SLY UPSLOPE FLOW ACROSS THE MTNS OF THE WRN CAROLINAS AND NE GA. AT
LEAST THAT/S WHERE THE CLOUDS ARE THE THICKEST AT THIS TIME.
ELSEWHERE IT/S MAINLY CLEAR. THIS GENERAL SKY TREND SHOULD CONTINUE
THROUGH ABOUT MID-MORNING. THERE STILL MIGHT BE A BRIEF PERIOD OF
LOW STRATUS AROUND SUNRISE...BUT A POCKET OF DRIER AIR WORKING INTO
THE FA FROM THE SOUTH AND CONTINUED LIGHT MIXING MORE THAN LIKELY
WILL KEEP THIS FROM HAPPENING. FOR THIS AFTERNOON A DEEP LAYER RIDGE
WILL CONTINUE TO BUILD ACROSS THE REGION AND LITTLE IF ANY
CONVECTION IS ANTICIPATED. THE ONE AREA THAT COULD SEE SOME ISOLATED
SHRA/TSTM ACTIVITY IS RIGHT ALONG THE TN LINE. AND ANYTHING THAT
DEVELOPS IN THIS AREA SHOULD SUBSEQUENTLY DRIFT INTO ERN TN. WE
ALREADY HAD A SMALL AREA OF SLIGHT CHANCE POPS IN THIS AREA AND I
ONLY MADE SOME MINOR TWEAKS.
THE ONE FORECAST ELEMENT OF NOTE TONIGHT IS THAT MORE OF THE MODEL
GUIDANCE WANTS TO DEVELOP STRATUS AFTER MIDNIGHT. THE NAM BUFKIT
SOUNDINGS STRONGLY IMPLY THIS WILL HAPPEN AND IT/S OFTEN RIGHT. WE
ONLY HAVE A MODEST INCREASE IN SKY COVER OVERNIGHT TO ACCOUNT FOR
THIS AS I/M STILL A LITTLE SKEPTICAL CONSIDERING THE STRENGTH OF THE
RIDGE.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 145 AM WEDNESDAY...QUIET WEATHER WILL CONTINUE IN THE SHORT
TERM...AS THE 500 MB HIGH WILL BE AT MAX STRENGTH AROUND 00Z FRI AT
590 DAM INVOF THE VA CAPES. FROM THERE THE HIGH WILL BEGIN A SLOW
WEAKENING TREND AND A SHIFT TO THE EAST. MODELS ARE GENERALLY
LACKING IN QPF RESPONSE BOTH THU AND FRI. AND LOOKING AT THE FCST
SNDGS...THE SUBSIDENCE INVERSION SHUD PRECLUDE ANY DEEP CONVECTION.
(ALTHO A FEW ISOLD CELLS CANNOT BE RULED OUT IN THE MTNS THIS TIME
OF YEAR). HIGHS WILL BE A CATEORY OR TWO ABOVE NORMAL BOTH DAYS.
OVERNIGHT LOWS WILL BE A LITTLE TRICKIER...AS A PERSISTENT SELY FLOW
OFF THE ATLANTIC MAY PRODUCE SOME MORNING STRATUS BOTH THURSDAY AND
FRIDAY MORNINGS. THIS IS MOST LIKELY TO OCCUR IN THE WESTERN HALF OF
THE CWFA. ANY LOW CLOUDS SHUD QUICKLY SCATTER OUT BY MIDDAY BOTH
DAYS.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 200 AM WEDNESDAY...AN UPPER RIDGE THAT HAS DOMINATED THE EAST
COAST WILL BREAK DOWN THIS WEEKEND...AND BE REPLACED BY A POSITIVELY
TILTED UPPER TROF FOR SUNDAY THRU TUESDAY. THE TROF WILL BRING
PLENTY OF MOISTURE WITH A WEAKLY FORCED COLD FRONT. SATURDAY LOOKS
LIKE THE LAST DRY DAY BEFORE UNSETTLED WEATHER RETURNS TO THE CWFA.
THERE MAY BE SOME MODEST INCREASE IN MOISTURE SATURDAY AHEAD OF THE
TROF. AND WITH SUBSIDENCE INVERSION WEAKENING...COULD SEE A FEW
SHWRS AND TSTMS DEVELOPING THE NC MTNS. WILL GO WITH SLGT CHC FOR
SAT AFTN. AS THE FRONT APPROACHES ON SUNDAY...CHC POPS RETURN TO THE
AREA. THE FRONT WILL SLOWLY CROSS THE CWFA MONDAY AND
TUESDAY...KEEPING A SOLID CHC ON MONDAY...SHIFTING TO EASTERN HALF
OF THE AREA ON TUESDAY. DECENT AMOUNT OF CAPE IN THE GFS AND
ECWMF...BUT SHEAR LOOKS FAIRLY WEAK IN THIS UPCOMING PATTERN. SO NOT
SURE HOW MUCH CONVECTION WILL BE ABLE TO ORGANIZE ALONG/INVOF THE
FRONTAL BNDRY. TEMPS WILL TO BE SLIGHTLY ABOVE NORMAL SATURDAY AND
SUNDAY...THEN NEAR NORMAL MONDAY AND TUESDAY.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT AND ELSEWHERE...STRATUS HAS STARTED TO DEVELOP IN TWO
LOCATIONS ACROSS THE REGION. THE LARGER AREA HAS DEVELOPED OVER
NORTH CENTRAL GA...BETWEEN MACON...ATLANTA AND ATHENS. THESE CLOUDS
WERE MAINLY MOVING OFF TO THE NORTH. THE RUC 925 MB WINDS REMAIN OUT
OF THE SOUTH ACROSS THIS AREA THE NEXT CPL HOURS AND THESE CLOUDS
SHOULD MISS ALL THE TAF SITES TO THE WEST...THOUGH IT WILL BE CLOSE
AT KAND AND I/VE ADDED FEW010. ANOTHER AREA WAS DEVELOPING NORTH OF
AIKEN OVER THE MIDLANDS. THIS AREA HAS NOT BEEN EXPANDING AND IS
SITUATED IN AN AREA OF FAIRLY LOW DEWPOINTS. EVEN THOUGH THE LLVL
FLOW WOULD TAKE THESE CLOUDS TOWARD KCLT...THEY WOULDN/T ARRIVE
UNTIL 13 UTC AND BY THEN THEY SHOULD HAVE MIXED OUT OR AT LEAST
LIFTED INTO A SCT CU DECK. OTHERWISE IT WILL BE A DRY DAY ACROSS THE
REGION. WINDS WILL BE A LITTLE LIGHTER THAN YDAY...AVERAGING 5 TO 8
KTS FROM THE SOUTH. CHANCES FOR MORE WIDESPREAD STRATUS ARE LOOKING
BETTER TONIGHT. FOR NOW I/VE JUST ADDED FEW010 TO THE I-85 CORRIDOR
TAF SITES. THERE COULD BE MORE FOG AROUND TONIGHT AS THE LOW WILL BE
LIGHT. I/D CERTAINLY EXPECT QUITE A BIT JUST TO OUR EAST AT THE VERY
LEAST WHERE THE CONDENSATION PRESSURE DEFICITS FALL TO ZERO.
OUTLOOK...GENERALLY FAIR CONDITIONS ARE EXPECTED THROUGH SATURDAY.
BRIEF MORNING RESTRICTIONS IN FOG OR HAZE WILL BE POSSIBLE...MAINLY
IN THE MTN VALLEYS. CHANCES FOR MAINLY AFTERNOON/EVENING SHOWERS AND
THUNDERSTORMS WILL INCREASE SIGNIFICANTLY BY SUNDAY AFTERNOON...AS A
COLD FRONT APPROACHES FROM THE TENN VALLEY.
CONFIDENCE TABLE...
11-17Z 17-23Z 23-05Z 05-11Z
KCLT HIGH 98% HIGH 100% HIGH 100% HIGH 90%
KGSP HIGH 100% HIGH 100% HIGH 93% MED 68%
KAVL HIGH 98% HIGH 100% HIGH 93% MED 71%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 90%
KGMU HIGH 100% HIGH 100% HIGH 93% MED 68%
KAND MED 73% HIGH 100% HIGH 93% MED 66%
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...ARK
NEAR TERM...MCAVOY
SHORT TERM...ARK
LONG TERM...ARK
AVIATION...MCAVOY
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
559 PM CDT WED MAY 29 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 404 PM CDT WED MAY 29 2013
COMPLEX SCENARIO TONIGHT BUT THE OVERALL MESSAGE LOOKS TO BE A LOW
END THREAT FOR SEVERE THUNDERSTORMS WITH A BETTER THREAT FOR
LOCALIZED HEAVY RAINFALL. CONVECTION CONTINUES TO SKIRT ALONG THE
WESTERN AND EASTERN EDGES OF THE CWA AS CONVECTION IN NEBRASKA
CONTINUES TO WEAKEN AS IT MOVES NORTH. SHEAR VALUES ARE MINIMALLY
SUPPORTIVE OF SEVERE CONVECTION WHILE CAPE VALUES ARE AROUND 1000 TO
1500 J/KG BUT OF THE VERY SKINNY VARIETY. THUS STARTING TO TREND
THINKING TOWARDS THE CONSISTENT HRRR WHICH FOR 5 RUNS IN A ROW HAS
PRODUCED A LARGE MCS WHICH CONGEALS FROM THE CONVECTION THAT IS
CURRENTLY DEVELOPING OVER THE WESTERN HIGH PLAINS. WILL RUN A BLEND
OF HPC/LOW RESOLUTION MODELS ALONG WITH THE HRRR AND RAP OUTPUT.
THE MAIN TAKE FROM THIS IS THAT THERE STILL APPEARS TO BE THE THREAT
FOR STORMS TO PRODUCE LOCALIZED RAINFALL AMOUNTS OF 3 TO 4 INCHES
WITH SLOW STORM MOVEMENT. WITH MOST LOCATIONS FLASH FLOOD GUIDANCE
RIGHT AROUND AN INCH AND A HALF OR A LITTLE MORE FLASH FLOODING WILL
BE A THREAT. THERE IS LIKELY TO BE A LULL IN CONVECTIVE ACTIVITY
LATE TONIGHT INTO TOMORROW MORNING THEN THE POTENTIAL FOR MORE
THUNDERSTORMS TOMORROW AFTERNOON...ESPECIALLY IN NORTHWEST IOWA AND
MAINLY SOUTHEAST PARTS OF SOUTHWEST MINNESOTA. CAPE VALUES JUST A
BIT MORE STOUT TOMORROW AND WIND SHEAR JUST A TOUCH BETTER SO AGAIN
NOT A WIDESPREAD THREAT BUT A THREAT NONETHELESS. LOWS TONIGHT
MAINLY 60 TO 65 WITH HIGHS ON THURSDAY IN THE MID 70S.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 404 PM CDT WED MAY 29 2013
LINGERING CONVECTION FROM DEVELOPMENT ON THURSDAY AFTERNOON WILL BE
SWINGING FAIRLY RAPIDLY THROUGH WITH STRONG PV LOBE LIFTING TO THE
NORTHEAST. MAIN UPPER WAVE WILL BE FAIRLY SLOW TO WOBBLE THROUGH THE
DAKOTAS THROUGH EARLY IN THE WEEKEND...BUT FIRST PART OF THIS PERIOD
WILL INTRODUCE A DRY SLOT AHEAD OF UPPER CIRCULATION THURSDAY NIGHT
INTO EARLY FRIDAY. AREA OF DIV Q BRUSHES UP AGAINST THE FAR
SOUTHEAST LATE AND WHILE BEST CHANCE FOR PRECIPITATION WILL CONTINUE
WELL SOUTHEAST...DID NUDGE A SMALL CHANCE FOR A LIGHT SHOWER INTO
THE FAR SOUTHEAST FOR A FEW HOURS AROUND DAYBREAK ON FRIDAY. IN
GENERAL...THE DRIER AIR WILL WORK THROUGH AREAS SOUTH OF THE UPPER
LOW AND WITH DIMINISHING WINDS ON THURSDAY NIGHT...WILL FIND LOWS
BACK IN THE UPPER 40S TO LOWER 50S FOR MOST.
SEVERAL DETERMINISTIC MODELS INDICATE A WEAK CONVERGENCE BOUNDARY
SLIDING THROUGH THE AREA ON LATER FRIDAY AFTERNOON AND FRIDAY
EVENING. AIRMASS DOES GET SOMEWHAT UNSTABLE...AND APPEARS TO BE
SETUP FOR DECENT MIXING WITH THE WEST TO SOUTHWEST FLOW COMPONENT AT
LOWER LEVELS THROUGH THE DAY. NET EFFECT WILL LIKELY BE AN ALMOST
UNCAPPED PROFILE WITH 400-700 J/KG INSTABILITY AND UNIMPRESSIVE
SHEAR. LIKELY WILL BE THE UNFAVORABLE AND WEAKLY SUBSIDENT LARGER
SCALE THAT WILL KEEP ACTION AT BAY UNTIL LATER INTO THE DIURNAL
CYCLE...WHEN PERHAPS SOME WEAK LOW LEVEL MOISTURE POOLING DUE TO
INDUCING SOMEWHAT STRONGER CONVERGENCE THAN MODEL INDICATED. STILL
WILL BE FAIRLY ISOLATED TO SCATTERED EVEN IT DOES DEVELOP WITH
MOISTURE LIMITATIONS.
AFTER VERY SHORT TERM...LOOKS LIKE LATER FRIDAY NIGHT INTO SATURDAY
WILL BE THE BEST CHANCE FOR PRECIPITATION ACROSS THE AREA...ALBEIT
MUCH LIGHTER THAN SHORTEST RANGE PRECIPITATION. UPPER TROUGH SWINGS
PAST WITH VERY COOL TEMPERATURES ALOFT. SHOULD BE PLENTY OF LOWER
LEVEL SHOWERS EVEN BEHIND PASSAGE OF UPPER WAVE ON SATURDAY
AFTERNOON WHICH CONTINUE TO ROTATE THROUGH NORTHEASTERN CWA.
BLUSTERY AND COOL DAY...WITH HIGHS UPPER 50S TO MID 60S. GFS
ENSEMBLE TEMPERATURE GUIDANCE STRONGLY SUGGESTS THAT COOLER IS
BETTER FOR SATURDAY. WINDS WILL DIMINISH...BUT A COOL NIGHT ON
SATURDAY NIGHT AS CLEARING PUSHES INTO THE WEST HALF.
FOR THE EXTENDED RANGE /SUNDAY THROUGH WEDNESDAY/ A FAIRLY QUIET
START WITH BRIEF RIDGING IN PLACE. STRETCHED OUT THE DIURNAL RANGE A
BIT FROM INITIALIZATION...AS EVEN WITH WET GROUND SHOULD BE ABLE TO
GET TOWARD FULL 850 HPA MIXING ON SUNDAY. DEVELOPMENT OF RETURN FLOW
FROM WEST TO EAST ON SUNDAY NIGHT INTO MONDAY MORNING. GFS/ECMWF
SHOWING SOME WEAK ELEVATED INSTABILITY/MOISTURE RETURN BY LATER
MONDAY...AND RELUCTANTLY INTRODUCED A LOW CHANCE FOR THUNDERSTORMS.
ANOTHER UPPER TROUGH WILL SETTLE INTO THE NORTHERN PLAINS TUESDAY
INTO WEDNESDAY...BUT THIS SOURCE WILL BE WITHIN LARGER SCALE
NORTHWEST FLOW AND IS SOMEWHAT MORE PROGRESSIVE THAN SHORT TERM
SYSTEM. SOME UNCERTAINTY IN TIMING AS BOUNDARY PUSHES THROUGH THE
AREA BUT HIGHEST CHANCES APPEAR CURRENTLY TO WORK THROUGH DURING THE
MONDAY NIGHT THROUGH TUESDAY NIGHT PERIOD. GENERALLY...TEMPERATURES
WILL BE WORKING SLOWLY UPWARD THROUGH TUESDAY...THEN SLIPPING BACK A
TOUCH WITH BOUNDARY PASSAGE AND PRECIPITATION LATER TUESDAY INTO
WEDNESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 559 PM CDT WED MAY 29 2013
A MORE ORGANIZED ROUND OF THUNDERSTORMS WILL PUSH SSW TO NNE
ACROSS THE AREA THIS MID TO LATE EVENING...AFFECTING THE
HON/FSD/SUX TAF SITES. MVFR CONDITIONS ARE EXPECTED WITH THESE
STORMS...AND SOME WILL CONTAIN LARGE HAIL AND VERY STRONG WIND
GUSTS TO 50+ KTS. A MOIST AIRMASS WILL SETTLE OVER THE REGION
AGAIN LATE TONIGHT/EARLY THURSDAY WITH WIDESPREAD IFR CONDITIONS
LOOKING LIKELY.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR SDZ061-062-066-
067-070-071.
MN...NONE.
IA...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR IAZ001>003-
012>014-020>022-031-032.
NE...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR NEZ013-014.
&&
$$
SHORT TERM...08
LONG TERM...CHAPMAN
AVIATION...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
404 PM CDT WED MAY 29 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 404 PM CDT WED MAY 29 2013
COMPLEX SCENARIO TONIGHT BUT THE OVERALL MESSAGE LOOKS TO BE A LOW
END THREAT FOR SEVERE THUNDERSTORMS WITH A BETTER THREAT FOR
LOCALIZED HEAVY RAINFALL. CONVECTION CONTINUES TO SKIRT ALONG THE
WESTERN AND EASTERN EDGES OF THE CWA AS CONVECTION IN NEBRASKA
CONTINUES TO WEAKEN AS IT MOVES NORTH. SHEAR VALUES ARE MINIMALLY
SUPPORTIVE OF SEVERE CONVECTION WHILE CAPE VALUES ARE AROUND 1000 TO
1500 J/KG BUT OF THE VERY SKINNY VARIETY. THUS STARTING TO TREND
THINKING TOWARDS THE CONSISTENT HRRR WHICH FOR 5 RUNS IN A ROW HAS
PRODUCED A LARGE MCS WHICH CONGEALS FROM THE CONVECTION THAT IS
CURRENTLY DEVELOPING OVER THE WESTERN HIGH PLAINS. WILL RUN A BLEND
OF HPC/LOW RESOLUTION MODELS ALONG WITH THE HRRR AND RAP OUTPUT.
THE MAIN TAKE FROM THIS IS THAT THERE STILL APPEARS TO BE THE THREAT
FOR STORMS TO PRODUCE LOCALIZED RAINFALL AMOUNTS OF 3 TO 4 INCHES
WITH SLOW STORM MOVEMENT. WITH MOST LOCATIONS FLASH FLOOD GUIDANCE
RIGHT AROUND AN INCH AND A HALF OR A LITTLE MORE FLASH FLOODING WILL
BE A THREAT. THERE IS LIKELY TO BE A LULL IN CONVECTIVE ACTIVITY
LATE TONIGHT INTO TOMORROW MORNING THEN THE POTENTIAL FOR MORE
THUNDERSTORMS TOMORROW AFTERNOON...ESPECIALLY IN NORTHWEST IOWA AND
MAINLY SOUTHEAST PARTS OF SOUTHWEST MINNESOTA. CAPE VALUES JUST A
BIT MORE STOUT TOMORROW AND WIND SHEAR JUST A TOUCH BETTER SO AGAIN
NOT A WIDESPREAD THREAT BUT A THREAT NONETHELESS. LOWS TONIGHT
MAINLY 60 TO 65 WITH HIGHS ON THURSDAY IN THE MID 70S.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 404 PM CDT WED MAY 29 2013
LINGERING CONVECTION FROM DEVELOPMENT ON THURSDAY AFTERNOON WILL BE
SWINGING FAIRLY RAPIDLY THROUGH WITH STRONG PV LOBE LIFTING TO THE
NORTHEAST. MAIN UPPER WAVE WILL BE FAIRLY SLOW TO WOBBLE THROUGH THE
DAKOTAS THROUGH EARLY IN THE WEEKEND...BUT FIRST PART OF THIS PERIOD
WILL INTRODUCE A DRY SLOT AHEAD OF UPPER CIRCULATION THURSDAY NIGHT
INTO EARLY FRIDAY. AREA OF DIV Q BRUSHES UP AGAINST THE FAR
SOUTHEAST LATE AND WHILE BEST CHANCE FOR PRECIPITATION WILL CONTINUE
WELL SOUTHEAST...DID NUDGE A SMALL CHANCE FOR A LIGHT SHOWER INTO
THE FAR SOUTHEAST FOR A FEW HOURS AROUND DAYBREAK ON FRIDAY. IN
GENERAL...THE DRIER AIR WILL WORK THROUGH AREAS SOUTH OF THE UPPER
LOW AND WITH DIMINISHING WINDS ON THURSDAY NIGHT...WILL FIND LOWS
BACK IN THE UPPER 40S TO LOWER 50S FOR MOST.
SEVERAL DETERMINISTIC MODELS INDICATE A WEAK CONVERGENCE BOUNDARY
SLIDING THROUGH THE AREA ON LATER FRIDAY AFTERNOON AND FRIDAY
EVENING. AIRMASS DOES GET SOMEWHAT UNSTABLE...AND APPEARS TO BE
SETUP FOR DECENT MIXING WITH THE WEST TO SOUTHWEST FLOW COMPONENT AT
LOWER LEVELS THROUGH THE DAY. NET EFFECT WILL LIKELY BE AN ALMOST
UNCAPPED PROFILE WITH 400-700 J/KG INSTABILITY AND UNIMPRESSIVE
SHEAR. LIKELY WILL BE THE UNFAVORABLE AND WEAKLY SUBSIDENT LARGER
SCALE THAT WILL KEEP ACTION AT BAY UNTIL LATER INTO THE DIURNAL
CYCLE...WHEN PERHAPS SOME WEAK LOW LEVEL MOISTURE POOLING DUE TO
INDUCING SOMEWHAT STRONGER CONVERGENCE THAN MODEL INDICATED. STILL
WILL BE FAIRLY ISOLATED TO SCATTERED EVEN IT DOES DEVELOP WITH
MOISTURE LIMITATIONS.
AFTER VERY SHORT TERM...LOOKS LIKE LATER FRIDAY NIGHT INTO SATURDAY
WILL BE THE BEST CHANCE FOR PRECIPITATION ACROSS THE AREA...ALBEIT
MUCH LIGHTER THAN SHORTEST RANGE PRECIPITATION. UPPER TROUGH SWINGS
PAST WITH VERY COOL TEMPERATURES ALOFT. SHOULD BE PLENTY OF LOWER
LEVEL SHOWERS EVEN BEHIND PASSAGE OF UPPER WAVE ON SATURDAY
AFTERNOON WHICH CONTINUE TO ROTATE THROUGH NORTHEASTERN CWA.
BLUSTERY AND COOL DAY...WITH HIGHS UPPER 50S TO MID 60S. GFS
ENSEMBLE TEMPERATURE GUIDANCE STRONGLY SUGGESTS THAT COOLER IS
BETTER FOR SATURDAY. WINDS WILL DIMINISH...BUT A COOL NIGHT ON
SATURDAY NIGHT AS CLEARING PUSHES INTO THE WEST HALF.
FOR THE EXTENDED RANGE /SUNDAY THROUGH WEDNESDAY/ A FAIRLY QUIET
START WITH BRIEF RIDGING IN PLACE. STRETCHED OUT THE DIURNAL RANGE A
BIT FROM INITIALIZATION...AS EVEN WITH WET GROUND SHOULD BE ABLE TO
GET TOWARD FULL 850 HPA MIXING ON SUNDAY. DEVELOPMENT OF RETURN FLOW
FROM WEST TO EAST ON SUNDAY NIGHT INTO MONDAY MORNING. GFS/ECMWF
SHOWING SOME WEAK ELEVATED INSTABILITY/MOISTURE RETURN BY LATER
MONDAY...AND RELUCTANTLY INTRODUCED A LOW CHANCE FOR THUNDERSTORMS.
ANOTHER UPPER TROUGH WILL SETTLE INTO THE NORTHERN PLAINS TUESDAY
INTO WEDNESDAY...BUT THIS SOURCE WILL BE WITHIN LARGER SCALE
NORTHWEST FLOW AND IS SOMEWHAT MORE PROGRESSIVE THAN SHORT TERM
SYSTEM. SOME UNCERTAINTY IN TIMING AS BOUNDARY PUSHES THROUGH THE
AREA BUT HIGHEST CHANCES APPEAR CURRENTLY TO WORK THROUGH DURING THE
MONDAY NIGHT THROUGH TUESDAY NIGHT PERIOD. GENERALLY...TEMPERATURES
WILL BE WORKING SLOWLY UPWARD THROUGH TUESDAY...THEN SLIPPING BACK A
TOUCH WITH BOUNDARY PASSAGE AND PRECIPITATION LATER TUESDAY INTO
WEDNESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1239 PM CDT WED MAY 29 2013
ROUGH SET OF TAF FORECASTS THIS GO AROUND WITH SCATTERED SHOWERS
AND THUNDERSTORMS ACROSS THE ENTIRE FORECAST AREA. THESE SHOWERS
AND THUNDERSTORMS ARE SHORT LIVED AND ANY ONE LOCATION NOT LIKELY
TO HAVE MORE THAN 15 TO 30 MINUTES OF RAIN/THUNDER SO WITH NO REAL
EASY WAY TO GET THIS POINT ACROSS IN A TAF FORECAST WILL LEAVE OUT
FOR NOW. WILL HOWEVER HIT THUNDER AND RAIN A LITTLE HARDER AFTER
0Z AS A POTENTIALLY MORE ORGANIZED AREA OF THUNDERSTORMS SHOULD
MOVE NORTHEAST FROM NEBRASKA. THESE STORMS WILL HAVE SOME
POTENTIAL TO PRODUCE STRONG WINDS...ESPECIALLY FROM ABOUT 1Z
THROUGH 5Z. WIDESPREAD MVFR CONDITIONS EXPECTED WITH SOME IFR
CEILINGS POSSIBLE AFTER ABOUT 6Z.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR SDZ061-062-066-
067-070-071.
MN...NONE.
IA...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR IAZ001>003-
012>014-020>022-031-032.
NE...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR NEZ013-014.
&&
$$
SHORT TERM...08
LONG TERM...CHAPMAN
AVIATION...08
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1233 AM CDT WED MAY 29 2013
.UPDATE...
SEE UPDATED AVIATION DISCUSSION BELOW.
NO MAJOR CHANGES TO THE GOING FORECAST THIS EVENING. THUNDERSTORMS
ARE CURRENTLY MOVING OVER THE BLACK HILLS AND WILL CONTINUE TO
PROGRESS NORTHEAST THIS EVENING. POPS AND WX MAY BE AN HOUR OR TWO
FAST BUT APPEAR TO BE IN DECENT SHAPE BASED ON CURRENT RADAR TRENDS.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM WITH THE
MAIN WEATHER FEATURES. A LARGE NEGATIVELY TILTED UPPER LEVEL LOW
PRESSURE TROUGH OVER THE SOUTHWEST US STILL SET TO KICK OUT INTO
THE NORTHERN PLAINS WEDNESDAY THROUGH THURSDAY AND CLOSING OFF
ACROSS OUR REGION. FOR TONIGHT...AN INITIAL WAVE WILL EJECT OUT
TONIGHT INTO OUR REGION BRINGING AN MCS ACROSS MAINLY THE SOUTHERN
CWA THIS EVENING AND OVERNIGHT. THE HRRR AND WRF MODELS BOTH SHOW
AN MCS MOVING ACROSS SOUTHERN SD TONIGHT. FOR MUCH OF THE EASTERN
CWA...IT WILL BE DRY THROUGH MUCH OF THE NIGHT. WITH CLEARING
SKIES AND WINDS BECOMING LIGHT TONIGHT...EXPECT SOME MORE FOG TO
FORM FROM THE JAMES VALLEY AND EAST TONIGHT AND REMAIN INTO
WEDNESDAY MORNING. THE MODELS ALSO SHOW A GOOD LLJ ALONG WITH GOOD
LOW AND MID LEVEL WAA DEVELOPING THROUGH THE NIGHT AND WEDNESDAY
MORNING. THIS WILL AID IN NUMEROUS SHOWER AND THUNDERSTORM
DEVELOPMENT LATER TONIGHT AND WEDNESDAY. BROAD SCALE UPPER LEVEL
DIVERGENCE WITH THE UPPER TROUGH WILL CONTINUE TO PROVIDE GOOD
ASCENT INTO WEDNESDAY NIGHT AND THURSDAY MORNING ACROSS THE CWA.
THE MODELS ALL SHOW A GOOD SURFACE LOW PRESSURE AREA IN EASTERN
COLORADO LIFTING NORTHEAST INTO NORTH DAKOTA WEDNESDAY AFTERNOON
INTO THURSDAY EVENING AND DEEPENING.
EVERYTHING IS SET FOR SOME SEVERE WEATHER POSSIBILITIES AND HEAVY
RAIN DEVELOPMENT WEDNESDAY AND WEDNESDAY NIGHT. THE THING THAT MAY
HOLD OFF MORE WIDESPREAD SEVERE WEATHER DEVELOPMENT WILL BE EARLY
SHOWER AND THUNDERSTORM DEVELOPMENT ACROSS THE CWA AND CLOUD COVER
THROUGH THE DAY AND EVENING WEDNESDAY. THIS WILL HOLD BACK THE
DEVELOPMENT OF HIGH INSTABILITY. NONETHELESS...DEEP LAYER
SHEAR...MOISTURE AND INSTABILITY WILL BE THERE FOR SOME SEVERE
STORMS ALONG WITH HEAVY RAINFALL. MADE SOME CALLS IN THE HEAVY
RAIN AREAS TODAY AND IT SEEMS MOST OF THE RAINFALL OVER THE LAST
SEVERAL DAYS HAD SOAKED IN PRETTY GOOD. HAVE INCREASED CHANCES OF
RAINFALL ACROSS THE REGION THROUGH WEDNESDAY NIGHT ALONG WITH
ADDING IN THE MENTION OF HEAVY RAIN AND SEVERE WEATHER
POSSIBILITIES. MUCH OF THE RAINFALL MAY END THURSDAY MORNING IN
THE EASTERN CWA AS THE DRY LINE/COLD FRONT SWINGS IN QUICKLY
THROUGH THE DAY BEHIND THE SURFACE LOW PRESSURE AREA. IN FACT...IT
MAY BECOME WINDY ACROSS THE CWA THURSDAY AFTERNOON AND EVENING
WITH A STRONG SURFACE LOW PRESSURE AREA TO THE NORTH ALONG WITH
GOOD MIXING. LOWERED POPS FOR THURSDAY NIGHT ACROSS THE CWA.
.LONG TERM...FRIDAY THROUGH TUESDAY
THE PERIOD BEGINS WITH A LARGE UPPER LEVEL LOW PRESSURE SYSTEM
SITUATED OVER THE NORTHERN PLAINS. THIS SYSTEM WILL BRING PERIODS
OF SHOWERS AND PERHAPS A THUNDERSTORM OR TWO DURING THE AFTERNOON
HOURS ON FRIDAY. CAPE VALUES ARE REDUCED SIGNIFICANTLY BY FRIDAY
NIGHT SO WILL ONLY MENTION SHOWERS THROUGH THE WEEKEND. DEPENDING
ON THE PLACEMENT OF THE LOW PRESSURE...HIGH TEMPERATURES ON
SATURDAY COULD BE PRETTY CHILLY. THE 12Z RUN OF THE ECMWF IS
SUGGESTING 925MB TEMPERATURES WILL ONLY WARM INTO THE MID/UPPER
SINGLE DIGITS. THANKFULLY THE GFS/GEM DEPICT SLIGHTLY WARMER LOW
LEVEL TEMPERATURES. OVERALL SATURDAY WILL BE CHILLY WITH HIGHS
ONLY IN THE UPPER 50S...TO THE MID 60S EXPECTED. SUNDAY WILL MARK
THE BEGINNING OF A WARMING TREND WITH TEMPERATURES FINALLY
REACHING ABOVE NORMAL BY MONDAY.
CHANCES FOR THUNDERSTORMS WILL RETURN TO THE FORECAST BY MONDAY
NIGHT. A SURFACE LOW PRESSURE AND COLD FRONT SLIDING ACROSS THE
REGION WILL BE THE FOCUS MECHANISM FOR CONVECTION.
&&
.AVIATION...
06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
PRIMARILY VFR CONDITIONS ARE EXPECTED THROUGH MOST OF THE NIGHT.
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE BETWEEN 06Z AND 07Z FOR
KPIR. ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS WILL DEVELOP AND
SPREAD OVER THE AREA WEDNESDAY MORNING AND AFTERNOON. MVFR CIGS
WILL BEGIN TO AFFECT THE TAF SITES WITH THESE STORMS. VSBY MAY ALSO
FALL TO MVFR/IFR IN HEAVIER CONVECTION ON WEDNESDAY.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...DORN
SHORT TERM...MOHR
LONG TERM...SD
AVIATION...DORN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1214 PM CDT WED MAY 29 2013
.UPDATE...
18Z TAF DISCUSSION.
&&
.AVIATION...
SURFACE OBS INDICATE DEWPOINTS HAVE RISEN INTO THE 60S
AREAWIDE...AND SATELLITE IMAGERY SHOWS A CORRESPONDING EXTENSIVE
CUMULUS FIELD HAS FORMED ACROSS THE MID STATE. EXPECT SCT-BKN VFR
CIGS THIS AFTERNOON BUT NO -SHRA/-TSRA IS ANTICIPATED NEAR
AIRPORTS. SFC WIND DIRECTION HAS BEEN VARYING WILDLY BETWEEN
SOUTHEAST AND WEST THIS MORNING...AND HAVE COMPROMISED WITH A SW
TO SSW DIRECTION FOR TAFS. SPEEDS OF 5 TO 11 KTS WITH OCCASIONAL
GUSTS UP TO 20 KTS POSSIBLE. WINDS WILL ONLY SLIGHTLY SUBSIDE
OVERNIGHT AS SOUTHERLY LLJ INCREASES TO 25-35 KTS.
SHAMBURGER
&&
.PREV DISCUSSION... /ISSUED 906 AM CDT WED MAY 29 2013/
UPDATE...
TEMPERATURES ARE WARMING QUICKLY THIS MORNING WITH MOST SURFACE
OBS ALREADY WELL INTO THE 70S TO NEAR 80. FORECAST HIGHS TEMPS IN
THE LOW 80S ON THE PLATEAU AND UPPER 80S ELSEWHERE STILL LOOK ON
TRACK...AND A FEW LOCATIONS COULD TOUCH THE 90 DEGREE MARK THIS
AFTERNOON. SATELLITE IMAGERY AND REGIONAL SURFACE OBS SHOW AN
AREA OF DEEPER MOISTURE SPREADING NORTHWESTWARD ACROSS
MISSISSIPPI/ALABAMA WITH PWATS UP TO 1.50 INCHES PER 12Z LIX
SOUNDING. THIS MOISTURE WILL ENTER WESTERN TENNESSEE LATER
TODAY...AND A COUPLE OF MODELS LIKE THE HRRR AND 4.0 KM WRF
INDICATE AN ISOLATED SHOWER IS NOT OUT OF THE QUESTION ALONG OUR
WESTERN AND SOUTHWESTERN CWA BORDERS. HOWEVER...RISING HEIGHTS
ALOFT ACROSS THE MID STATE DUE TO THE LARGE TROUGH EJECTING OUT
INTO THE PLAINS COMBINED WITH SUBSTANTIAL DRY AIR THROUGHOUT THE
COLUMN IS EXPECTED TO SUPPRESS CONVECTIVE DEVELOPMENT AND WILL
LEAVE INHERITED DRY FORECAST AS IS. REST OF FORECAST ALSO REMAINS
ON TRACK AND NO CHANGES WERE MADE.
SHAMBURGER
PREV DISCUSSION... /ISSUED 330 AM CDT WED MAY 29 2013/
DISCUSSION...
UPPER RIDGING EXTENDS FROM JUST SOUTH OF BERMUDA IN THE ATLANTIC NW
THROUGH GA AND TN. UPPER TROUGH MOVING EAST ACROSS THE NORTHERN
ROCKIES WITH A GENERAL SW FLOW ALOFT FROM TX NE TO THE GREAT LAKES.
THE AFOREMENTIONED UPPER TROUGH WILL CONTINUE TO MOVE EAST AND WE
WILL SEE THE RIDGE AXIS SHIFT EAST AS WELL. THOUGH 18Z CAP EROSION
IS PRONOUNCED TODAY...MRH LEVELS ARE RATHER LOW AND CAPES AS WELL.
NOT SEEING MUCH IN THE WAY OF CONVECTIVE DEVELOPMENT ACROSS THE MID
STATE. HOWEVER...AS WE BEGIN TO GET MORE AND MORE INTO THE SW FLOW
ALOFT IN THE DAYS TO COME...CAPES AND MOISTURE WILL BE ON THE
INCREASE. LOW POPS WILL BE NEEDED ON THURSDAY AND WILL SLOWLY
INCREASE INTO THE WEEKEND. TEMPERATURES WILL CONTINUE TO RUN A
LITTLE ABOVE NORMAL...BUT ANY ENHANCED THERMAL RIDGING SHOULD REMAIN
CONFINED TO OLD MEXICO.
VERSUS THE NEAR TERM GUIDANCE...WILL ELECT TO DIFFER LITTLE IF ANY
FROM THE MAV. MET DATA LOOKING A LITTLE TOO LOW WITH DAY TIME
HIGHS.
IN THE EXT FCST...STILL EXPECTING THE COLD FRONT TO APPROACH THIS
WEEKEND WITH THE FROPA OCCURRING SUNDAY NIGHT. THUS...POPS WILL BE
HIGHEST SAT NT AND SUNDAY. STILL LOOKING AT THE POSSIBILITY OF A FEW
STRONG STORMS FOR SAT AND SUN DURING THE AFT/EVE HOURS. SLIGHTLY
COOLER AND DRIER AIR IS EXPECTED BY TUESDAY BEHIND THE FRONT. WILL
LEAN TOWARD THE SLIGHTLY COOLER EURO MOS THROUGH MUCH OF THE
EXTENDED.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
906 AM CDT WED MAY 29 2013
.UPDATE...
TEMPERATURES ARE WARMING QUICKLY THIS MORNING WITH MOST SURFACE
OBS ALREADY WELL INTO THE 70S TO NEAR 80. FORECAST HIGHS TEMPS IN
THE LOW 80S ON THE PLATEAU AND UPPER 80S ELSEWHERE STILL LOOK ON
TRACK...AND A FEW LOCATIONS COULD TOUCH THE 90 DEGREE MARK THIS
AFTERNOON. SATELLITE IMAGERY AND REGIONAL SURFACE OBS SHOW AN
AREA OF DEEPER MOISTURE SPREADING NORTHWESTWARD ACROSS
MISSISSIPPI/ALABAMA WITH PWATS UP TO 1.50 INCHES PER 12Z LIX
SOUNDING. THIS MOISTURE WILL ENTER WESTERN TENNESSEE LATER
TODAY...AND A COUPLE OF MODELS LIKE THE HRRR AND 4.0 KM WRF
INDICATE AN ISOLATED SHOWER IS NOT OUT OF THE QUESTION ALONG OUR
WESTERN AND SOUTHWESTERN CWA BORDERS. HOWEVER...RISING HEIGHTS
ALOFT ACROSS THE MID STATE DUE TO THE LARGE TROUGH EJECTING OUT
INTO THE PLAINS COMBINED WITH SUBSTANTIAL DRY AIR THROUGHOUT THE
COLUMN IS EXPECTED TO SUPPRESS CONVECTIVE DEVELOPMENT AND WILL
LEAVE INHERITED DRY FORECAST AS IS. REST OF FORECAST ALSO REMAINS
ON TRACK AND NO CHANGES WERE MADE.
SHAMBURGER
&&
.PREV DISCUSSION... /ISSUED 330 AM CDT WED MAY 29 2013/
DISCUSSION...
UPPER RIDGING EXTENDS FROM JUST SOUTH OF BERMUDA IN THE ATLANTIC NW
THROUGH GA AND TN. UPPER TROUGH MOVING EAST ACROSS THE NORTHERN
ROCKIES WITH A GENERAL SW FLOW ALOFT FROM TX NE TO THE GREAT LAKES.
THE AFOREMENTIONED UPPER TROUGH WILL CONTINUE TO MOVE EAST AND WE
WILL SEE THE RIDGE AXIS SHIFT EAST AS WELL. THOUGH 18Z CAP EROSION
IS PRONOUNCED TODAY...MRH LEVELS ARE RATHER LOW AND CAPES AS WELL.
NOT SEEING MUCH IN THE WAY OF CONVECTIVE DEVELOPMENT ACROSS THE MID
STATE. HOWEVER...AS WE BEGIN TO GET MORE AND MORE INTO THE SW FLOW
ALOFT IN THE DAYS TO COME...CAPES AND MOISTURE WILL BE ON THE
INCREASE. LOW POPS WILL BE NEEDED ON THURSDAY AND WILL SLOWLY
INCREASE INTO THE WEEKEND. TEMPERATURES WILL CONTINUE TO RUN A
LITTLE ABOVE NORMAL...BUT ANY ENHANCED THERMAL RIDGING SHOULD REMAIN
CONFINED TO OLD MEXICO.
VERSUS THE NEAR TERM GUIDANCE...WILL ELECT TO DIFFER LITTLE IF ANY
FROM THE MAV. MET DATA LOOKING A LITTLE TOO LOW WITH DAY TIME
HIGHS.
IN THE EXT FCST...STILL EXPECTING THE COLD FRONT TO APPROACH THIS
WEEKEND WITH THE FROPA OCCURRING SUNDAY NIGHT. THUS...POPS WILL BE
HIGHEST SAT NT AND SUNDAY. STILL LOOKING AT THE POSSIBILITY OF A FEW
STRONG STORMS FOR SAT AND SUN DURING THE AFT/EVE HOURS. SLIGHTLY
COOLER AND DRIER AIR IS EXPECTED BY TUESDAY BEHIND THE FRONT. WILL
LEAN TOWARD THE SLIGHTLY COOLER EURO MOS THROUGH MUCH OF THE
EXTENDED.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
254 PM PDT Wed May 29 2013
.SYNOPSIS...
Low pressure aloft will keep a chance for showers Thursday with
the highest threat for rain focusing over the northern and
eastern mountains. Most of the region will experience dry
conditions Friday coupled with warming temperatures. The warming
trend will continue into the weekend with a few weak disturbances
expected to clip far northeastern Washington and the Idaho
Panhandle keeping a small chance for showers in the forecast.
&&
.DISCUSSION...
Tonight...Slow moving upper level shortwave trough will remain
the dominant feature for tonight`s weather. As of 2pm...the base
of the trough was located near the Tri-Cities and was moving
slowly to the east-northeast. A NW-SE band of precipitation ahead
of the trough will deliver stratiform precipitation to locations
over NE Washington and much of the Idaho Panhandle through early
evening. Strangely enough this band moved over the Spokane area
and generally fell apart...but it remains intact to the northwest
and southeast. This band will likely weaken during the
evening...and most of the precipitation then will result from the
unstable conditions behind the band. The HRRR model continues to
forecast SBCAPE values between 300-700 j/kg over the southern
Columbia Basin near the negatively tilted trough axis through this
afternoon...before shifting it toward the WA/ID border by early
evening. This roughly matches whats transpiring on the latest
radar and satellite imagery with a line of showers and embedded
thunderstorms developing along a line from Mattawa to Walla Walla.
The threat of thunderstorms will likely persist through mid-
evening before tapering off overnight. Meanwhile elevated
instability ahead of the trough could still result in a few
showers through the night especially over extreme NE Washington
and the Idaho Panhandle. fx
Thursday through Saturday night: A northwest to southeast oriented
upper-level trof will remain anchored over the Inland NW Thursday
then begin a slow migration northward Friday and Saturday. This
will keep the threat for showers across the region on Thursday
with a drying trend for Friday. Another weak wave will track
across northern WA/ID late Saturday/Saturday night bringing a
small chance for showers but for the most part...most locations will
continue to experience generally dry conditions.
For Thursday, 500mb temperatures around -20C within the inner trof
will keep a pool of instability over the region. This is expected
to equate to widely scattered afternoon showers. The northern and
eastern mountains...expanding into the upper Columbia Basin will
carry the highest threat for precipitation. Across the southern
Columbia Basin and East Slopes...tightening pressure gradients
will bring a slight increase in winds which should help dry out
the boundary layer...resulting in decreasing surface based
instability and lowering chances for showers through the
afternoon. The trof will begin to migrate northward on Friday with
models indicating almost 6C of warming aloft (500mb). With the exception
of the far northern mountains...a dry day is in store for most and
only the ECMWF lingers enough instability over the northern
mountains to keep a slight chance of showers in the forecast. On
Saturday, a ridge of high pressure begins to amplify over the Gulf
of AK allowing a shortwave to drop into the region from the
northwest. This does not look like a very wet system but will
bring a slight increase in the threat for showers mainly north of
a line from Kellogg to Omak through the Saturday evening and
night time-frame.
Temperatures through the period will start off below normal and
slowly warm near normal by the weekend. This equates to highs in
60`s to low 70`s Thursday...warming into the 70`s to low 80`s
on Saturday. A few cold pockets within the northern mountains will
continue to drop into the 30`s at night but are expected to remain
just above freezing. /sb
Sunday through Wednesday: Models are in pretty good agreement of
an upper level low pressure system pushing through the Inland
Northwest Sunday. Latest ECMWF is a bit more robust and further
south with the low...bringing it along the WA/Canadian border. GFS
seems to be trending more towards an unsettled day as well. There are
still some discrepancies with this feature though. Have increased
chance of precipitation from the Spokane area north towards the
Canadian border and east to the MT state line for the afternoon and
early evening hours. There is even some instability associated
with the system moving through. For now have kept mention of
thunder out of the forecast, but will need to be evaluated again
as models come more in line with each other. Monday the trough
moves out of the area but showers are still possible along the
Idaho Panhandle. Tuesday and Wednesday a ridge of high pressure
will move into the Pacific Northwest. Have decreased chance of
precipitation and sky cover. Temperatures Sunday will be below average
and then trend to average by Monday and above average for Tue and
Wed. /Nisbet
&&
.AVIATION...
18Z TAFS: VFR conditions are expected at all the sites through
most of the period. Brief MVFR cigs will be possible however as a
NW-SE oriented band of rain moves through E WA and the ID
Panhandle this afternoon. The band has already moved through MWH
and EAT...but showers and even a thunderstorm will be possible
between 21z-01z at those sites. The band is expected to weaken
overnight...clearing PUW and LWS early this evening and GEG-COE
sometime after 03z. The threat of precip will ease for all sites
during the overnight hours and then the main risk is seeing a MVFR
or possibly an IFR stratus deck form over EC Washington late
tonight. The atmospheric setup is right for a band to form
somewhere over the eastern Columbia Basin...the question is will
it hit any of the airports. We put in a sct deck of clouds between
008-011 feet and have it impacting KGEG-KCOE aft 12z...but this
could prove underdone. fx
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 43 62 44 67 45 71 / 70 20 20 0 0 10
Coeur d`Alene 44 60 42 67 42 71 / 70 30 20 10 0 10
Pullman 41 58 40 66 41 71 / 70 20 10 0 0 0
Lewiston 46 68 46 73 47 79 / 60 20 10 0 0 0
Colville 47 65 43 74 43 75 / 80 50 20 10 0 20
Sandpoint 45 58 42 67 40 70 / 70 60 30 10 10 10
Kellogg 42 55 41 62 43 68 / 70 50 30 10 0 10
Moses Lake 46 72 46 74 47 78 / 50 10 0 0 0 10
Wenatchee 46 71 49 74 50 76 / 50 10 0 0 0 10
Omak 45 68 43 74 45 76 / 60 20 10 10 0 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1153 AM PDT Wed May 29 2013
.SYNOPSIS...
Widespread rain is expected over the Inland Northwest today as an
upper level disturbance moves through the region. Widely scattered
thunderstorms will be possible this afternoon as well. The best
chances for rain showers on Thursday will be over the Idaho
Panhandle. The weekend should be a bit warmer than average with a
chance for showers over the Idaho Panhandle once again.
&&
.DISCUSSION...
rest of today...fairly potent shortwave trough will be the main
focus for the weather this afternoon. Looking at the latest water
vapor image it suggests the base of the trough was located near
Hermiston and moving slowly east-northeast. So far most of the
precipitation from this trough was situated along a NW-SE
deformation band extending from the north Washington Cascades
toward Lewiston. The band is expected to drift NE through the
afternoon...however its progress will likely be slowed as the base
of the trough takes its time meandering near the WA/OR border.
There is some doubt whether this band will make it into the
northern third of the Idaho Panhandle by afternoon. The slower it
arrives...the better the chance of sparking some deep convection
due to diurnal heating from mostly sunny skies. Not sure there is
enough instability to produce a thunderstorm...but there is
certainly enough for showers. Locations on the backside of the
band...over the western Columbia Basin...Wenatchee
Area...Waterville Plateau...will see a brief break in the rain
threat...however another band of precipitation...currently over NC
Oregon will impact that region by this afternoon. Suspect this is
the region that will see the best chance of sparking a thunderstorm this
afternoon...as the RUC and the HRRR have consistently been
forecasting the highest CAPE values with little if any convective
inhibition. This threat of thunder will likely taper off early
this evening as the base of the trough begins to lift northeast.
The considerable cloudiness associated with the deformation band other
update for today was adjusting max temperatures down in some of
the areas which will be impacted by the deformation band. fx
&&
.AVIATION...
18Z TAFS: VFR conditions are expected at all the sites through
most of the period. Brief MVFR cigs will be possible however as a
NW-SE oriented band of rain moves through E WA and the ID
Panhandle this afternoon. The band has already moved through MWH
and EAT...but showers and even a thunderstorm will be possible
between 21z-01z at those sites. The band is expected to weaken
overnight...clearing PUW and LWS early this evening and GEG-COE
sometime after 03z. The threat of precip will ease for all sites
during the overnight hours and then the main risk is seeing a MVFR
or possibly an IFR stratus deck form over EC Washington late
tonight. The atmospheric setup is right for a band to form
somewhere over the eastern Columbia Basin...the question is will
it hit any of the airports. We put in a sct deck of clouds between
008-011 feet and have it impacting KGEG-KCOE aft 12z...but this
could prove underdone. fx
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 60 45 62 44 67 46 / 80 40 20 20 0 0
Coeur d`Alene 63 45 61 42 67 43 / 70 50 30 20 10 0
Pullman 58 43 61 40 66 42 / 80 30 20 10 0 0
Lewiston 63 47 68 46 73 48 / 80 30 20 10 0 0
Colville 68 46 68 43 74 43 / 80 50 50 20 10 0
Sandpoint 64 45 59 41 67 40 / 60 60 60 30 10 10
Kellogg 60 44 56 42 62 44 / 80 70 50 30 10 0
Moses Lake 64 47 72 45 74 47 / 70 20 10 0 0 0
Wenatchee 62 48 69 48 73 50 / 70 20 10 0 0 0
Omak 64 45 70 43 74 45 / 80 30 20 10 10 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
854 PM CDT THU MAY 30 2013
.UPDATE...
THINGS WILL GET QUIET ACROSS SOUTHERN WISCONSIN RATHER QUICKLY
TONIGHT. THE MAIN LINE OF STORMS WILL BE PUSHING OUT OVER THE LAKE
BETWEEN 9 AND 10 PM. THEN A PERIOD OF LIGHT RAIN WITH SOME
RUMBLING THUNDER AS WE STILL HAVE SOME H8 FLOW PUSHING UP AND OVER
THE COLD POOL. THEN IT ALL TAPERS OFF FOR A WHILE LATER TONIGHT.
WE THEN WILL SEE THE NEXT ROUND OF RAIN COME IN LATER TOMORROW AND
AFTERNOON WITH ANOTHER LOW PRESSURE SYSTEM DEVELOPING AND MOVING
UP INTO THE AREA.
&&
.AVIATION/06Z TAFS/...
VFR CONDITIONS EXPECTED DURING THE TAF PERIOD.
THE RAIN ACROSS THE SOUTHEAST WILL TAPER OFF FOR A TIME DURING THE
FIRST HOURS OF THE TAF PERIOD. THEN ANOTHER ROUND OF SHOWERS AND
STORMS COMES IN LATER FRIDAY MORNING AND AFTERNOON AS ANOTHER LOW
PRESSURE SYSTEM DEVELOPS AND ROTATES INTO THE AREA.
&&
.PREV DISCUSSION... /ISSUED 446 PM CDT THU MAY 30 2013/
SHORT TERM...
TONIGHT AND FRIDAY...FORECAST CONFIDENCE MEDIUM.
ONGOING SCATTERED CONVECTION WITH MORE DISCRETE-TYPE CELLS
ASSOCIATED WITH A VORT MAX ROTATING AROUND A NEGATIVELY TILTED 500MB
UPPER LOW OVER THE NORTHERN PLAINS...AND ON THE NOSE OF THE 850MB
LOW LEVEL JET. MOST OF THE SEVERE THUNDERSTORM WARNINGS HAVE BEEN
LARGE HAIL AND THE TOKEN DAMAGING WINDS. DECENT LOW LEVEL SHEAR AND
CAPE STILL WARRANTS TORNADO WATCH. WEAK TORNADOES ARE POSSIBLE. THE
STORMS MAY CONGEAL INTO BOWING LINE SEGMENTS LATER THIS AFTERNOON AS
THEY GET INTO SOUTHEAST WI PER THE 17Z HRRR MODEL RUN.
MEANWHILE... A STRONGER VORT MAX CURRENTLY OVER MISSOURI WILL ROLL
ACROSS IOWA AROUND 00Z. STORMS AHEAD OF THIS DISTURBANCE WILL MOST
LIKELY BE IN A LINE/MCS MODE AS IT REACHES NORTHERN IL/SOUTHERN WI.
EXPECTING THIS TO MOVE ACROSS ALL OF THE MKX AREA THIS EVENING.
LATEST 17Z HRRR SPED THIS UP WITH THE LEADING EDGE CLEARING EASTERN
WI BY 03Z...WHILE THE 12Z NAM DELAYS IT OVER THE MKX AREA FROM
03-09Z.
EXPECT A BREAK IN PRECIP LATE TONIGHT INTO FRIDAY MORNING AFTER THIS
SECONDARY ROUND. THEN WE WILL BE IN ANOTHER FAVORABLE SYNOPTIC SETUP
FOR MORE SEVERE STORMS ON FRIDAY. THE 500MB UPPER LOW WILL SHIFT A
LITTLE CLOSER INTO THE EASTERN DAKOTAS AND ANOTHER VORT MAX WILL
SWING INTO SOUTHERN WI AS THE LEFT EXIT REGION OF A 100KT UPPER JET
MOVES THROUGH. CONVECTIVE MODE WILL LIKELY BE A LINE OF STORMS WITH
A SUBTLE COLD-FRONT. DAMAGING WINDS THE MAIN SEVERE THREAT.
ONE UNCERTAINTY WITH FRIDAY THUNDERSTORMS WILL BE THAT THE LINE
COULD FORM IN ILLINOIS AND MOVE EAST AND JUST CLIP SOUTHEAST WI OR
EVEN MISS IT ALL TOGETHER.
FRIDAY NIGHT AND THROUGH SATURDAY...FORECAST CONFIDENCE...MEDIUM
TO HIGH
THE MID/UPPER TROUGH WILL PUSH INTO THE UPPER MISSISSIPPI VALLEY
REGION. THE 250 MB JET MAX INCREASES TO 100 KNOTS ACROSS SOUTHERN
AND NORTHEAST WISCONSIN WITH MODERATE UPPER DIVERGENCE OVER
SOUTHEAST WISCONSIN DURING THE EVENING.
SOUTHERN WISCONSIN WILL REMAIN IN THE WARM SECTOR FRIDAY EVENING
WITH A MID DRY PUNCH OVER MUCH OF THE AREA. THOUGH THE BEST LOW
LEVEL WIND MAX WILL BE TO THE SOUTH AND EAST...STRONGER STORMS
ARE NOT OUT OF THE QUESTION ESPECIALLY WITH WIND SHEAR A BIT
HIGHER THAN PREVIOUS DAYS. THE CWASP SEVERE PARAMETER IS HIGHEST
ACROSS NORTHEAST ILLINOIS LOWER VALUES EXTENDS CLOSER TO THE UPPER
LOW OVER PORTIONS OF SOUTH CENTRAL WISCONSIN.
WEAKENING LOW PRESSURE WILL FINALLY DRAG A COLD FRONT THROUGH
SOUTHERN WISCONSIN BY SATURDAY NIGHT. NAM FORECAST SOUNDINGS STILL
HAVE 1300 J/KM OF CAPE SATURDAY AFTERNOON IF FORECAST DEW POINTS
ARE NOT TOO HIGH.
LONG TERM...
SUNDAY THROUGH THURSDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
MAIN UPPER LEVEL TROUGH AXIS WILL MOVE ACROSS THE WESTERN GREAT LAKES
SATURDAY NIGHT THEN INTO SOUTHERN CANADA ON SUNDAY.
FORECAST SOUNDINGS SHOW MOISTURE TRAPPED BELOW AN INVERSION AROUND
7 THSD FT...SO EXPECT CUMULUS/STRATOCUMULUS SUNDAY. COOLER AIR IS
EXPECTED TO ARRIVE WITH THE SHORTWAVE.
THE GFS AND ECMWF ARE FAIRLY SIMILAR IN BRINGING ANOTHER UPPER
TROUGH ACROSS THE NORTHERN PLAINS MONDAY NIGHT AND REACHING THE
UPPER MISSISSIPPI VALLEY WEDNESDAY. ON THURSDAY THE GFS BRINGS THE
UPPER TROUGH ACROSS WISCONSIN WITH A BROADER MORE NORTH LOCATION
ON THE 00Z ECMWF.
STILL SOME POTENTIAL OF INSTABILITY SHOWERS SUNDAY BEFORE HIGH
PRESSURE DOMINATES WISCONSIN MONDAY.
BY TUESDAY SHOWERS/THUNDERSTORMS APPROACH THE MISSISSIPPI RIVER AREA
TUESDAY EVENING WITH A CHANCE OF SHOWERS/THUNDERSTORMS WEDNESDAY
AND THURSDAY.
EXPECT GUSTS BETWEEN 25 AND 30 KTS TO PERSIST UNTIL EVENING AS
MIXING CEASES. DISCRETE THUNDERSTORMS WITH SOME PRODUCING LARGE HAIL
MAINLY IN SOUTH CENTRAL WI. EXPECTING STORMS TO CONGEAL AT SOME
POINT AND STRAIGHT-LINE WINDS WILL BECOME THE MAIN THREAT FOR ALL OF
SOUTH CENTRAL AND SOUTHEAST WI. STORMS ARE DEVELOPING RAPIDLY...SO
WATCH THE RADAR CLOSELY FOR NEW DEVELOPMENTS. WEAK TORNADOES ARE
POSSIBLE WITH DECENT LOW-LEVEL ROTATION.
ANOTHER ROUND...A LINE OF THUNDERSTORMS...IS EXPECTED EARLY THIS
EVENING AND THESE WILL LIKELY SPREAD ALL THE WAY ACROSS SOUTHERN WI.
STRAIGHT-LINE WINDS WILL BE THE MAIN SEVERE WEATHER THREAT.
AFTER A BREAK LATE TONIGHT/EARLY FRIDAY...EXPECT A LINE OF
THUNDERSTORMS TO DEVELOP ALONG A WEAK COLD FRONT SOMEWHERE IN IA/IL
AND TRACK ENE MIDDAY FRIDAY. THESE MAY SWEEP ACROSS ALL OF SOUTHERN
WI OR JUST CLIP SOUTHEAST WI. STAY TUNED TO THE FORECAST FOR THIS
ONE.
MARINE...
GUSTY SOUTH WINDS DUE TO MIXING OVER THE LAND WILL AFFECT SHORELINE
NEARSHORE AREAS UNTIL THIS EVENING. WINDS WILL BE LESS GUSTY TOWARD
THE OPEN WATERS. HOWEVER...THE TIGHT PRESSURE GRADIENT OVER THE LAKE
WILL ALLOW SUSTAINED WINDS TO BE IN THE 15 TO 20 KNOT RANGE TODAY
AND TONIGHT. STABLE AIR DOWN AT LAKE LEVEL WILL KEEP WAVES FROM
RESPONDING TOO MUCH TO THE GUSTY WINDS.
THUNDERSTORMS EXPECTED THIS EVENING AND AGAIN FRIDAY MIDDAY AND
AGAIN SOMETIME ON SATURDAY.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...DAVIS
TONIGHT/FRIDAY AND AVIATION/MARINE...MRC
FRIDAY NIGHT THROUGH THURSDAY...HENTZ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
429 PM CDT WED MAY 29 2013
.UPDATE...
ISSUED AT 429 PM CDT WED MAY 29 2013
HAVE EXPANDED THE FLASH FLOOD WATCH EASTWARD TO INCLUDE
HOUSTON...ALLAMAKEE AND CLAYTON COUNTIES. PRESENT CONVECTION
TRACKING ACROSS WESTERN PORTIONS OF THE FORECAST AREA HAS BEEN
MOVING MORE SLOWLY ACROSS NORTHEAST IOWA...PRIMARILY DUE TO LOWER
0-6KM SHEAR THERE. AS THIS CONVECTION MOVES INTO THE EXPANSION
AREA...EXPECTING THE RAIN TO PRIME CONDITIONS FOR POSSIBLE FLASH
FLOODING...EITHER FROM THE CURRENT CONVECTION OR FROM ADDITIONAL
EXPECTED CONVECTION LATER TONIGHT INTO THURSDAY. ALSO STARTED THE
FLASH FLOOD WATCH NOW GIVEN CURRENT CONVECTION AND THE NEED FOR
WARNINGS SOONER THAN EXPECTED.
&&
.SHORT TERM...(TONIGHT THROUGH THURSDAY)
ISSUED AT 308 PM CDT WED MAY 29 2013
MAIN CONCERN IS SEVERE POTENTIAL GOING INTO THIS EVENING AND HEAVY
RAINFALL POTENTIAL THROUGH THURSDAY.
WATER VAPOR IMAGERY/RAP 500MB ANALYSIS SHOWS A DEEPENING TROUGH OF
LOW PRESSURE ACROSS THE CENTRAL ROCKIES INTO THE SOUTHERN PLAINS.
THIS IN TURN WAS DRIVING AN INCREASINGLY MOIST/UNSTABLE SOUTHERLY
SURFACE FLOW FROM THE PLAINS INTO THE UPPER MISSISSIPPI RIVER VALLEY
REGION. AT THE SURFACE LOW PRESSURE WAS LOCATED OVER SOUTHEAST CO
WITH A WARM FRONT EXTENDING NORTHEAST THROUGH IA INTO SOUTHERN WI.
CONVECTION/SOME STRONG TO SEVERE WAS FIRING ALONG/AHEAD OF THIS WARM
FRONT ON THE NOSE OF INCREASING 925-85OMB MOISTURE
TRANSPORT/INCREASING CAPE POOL. DEW POINTS ACROSS OUR AREA THIS
AFTERNOON WERE IN THE MID/UPPER 60S WITH AROUND 70 ACROSS EASTERN
IA.
LOOK FOR ONGOING SHOWER/THUNDERSTORM ACTIVITY THIS EVENING AS THE
WARM FRONT/NOSE OF RATHER INTENSE MOISTURE TRANSPORT CONTINUES TO PUSH NORTH
ACROSS THE AREA. RAP SHOWING 0-1KM MLCAPE IN THE 3000-3500J/KG WITH
INCREASING 0-3KM BULK SHEAR IN THE 25-35KT RANGE BETWEEN 4 PM AND 8
PM ACROSS PORTIONS OF NORTHEAST IA/SOUTHWEST WI. CAPE/BULK SHEAR AND
ENHANCED 0-1KM EHI VALUES WOULD FAVOR TORNADOGENESIS ALONG THE WARM
FRONT AS IT PUSHES THROUGH NORTHEAST IA/SOUTHWEST WI. WILL HAVE TO
KEEP AN EYE ON LARGE HAIL/DAMAGING WIND/TORNADIC POTENTIAL GOING INTO
EVENING. CAPE STARTS DWINDLING AFTER SUNSET...HOWEVER...MODELS
CONTINUE TO SHOW FETCH OF STRONG 925-850MB MOISTURE TRANSPORT
ADVECTING INTO OUR AREA OVERNIGHT INTO THURSDAY. THIS WILL BE AHEAD
OF A COLD FRONT PUSHING EASTWARD INTO THE CENTRAL PLAINS.
PRECIPITABLE WATER VALUES INCREASE INTO THE 1.5 TO 1.7IN RANGE. WITH
THIS IN MIND THERE WILL BE THE POTENTIAL WILL BE THERE FOR SOME
HEAVY RAINFALL. HAVE ISSUED A FLASH FLOOD WATCH FOR PORTIONS OF THE
AREA THIS EVENING THROUGH THURSDAY TO COVER THIS. SEE THE HYDROLOGY
SECTION BELOW FOR FURTHER DETAILS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 308 PM CDT WED MAY 29 2013
MAIN AXIS OF MOISTURE TRANSPORT/ENHANCED PRECIPITABLE WATER SHIFTS
EAST OF THE AREA THURSDAY NIGHT WITH A COLD FRONT LAGGING ACROSS
CENTRAL MN INTO EASTERN NEBRASKA/CENTRAL KS. SO...EXPECTING HEAVIER
RAINFALL TO TAPER OFF IN THE EVENING/OVERNIGHT FROM WEST TO EAST.
THE COLD FRONT WILL CONTINUE TO PUSH SLOWLY EAST INTO THE AREA
FRIDAY WITH INCREASING MOISTURE TRANSPORT INTO FAR SOUTHERN WI
DURING THE AFTERNOON. HAVE TAILORED SHRA/TS CHANCES WITH LIKELY
ACROSS THE SOUTH...TAPERING TO 40-50 POPS ACROSS THE NORTHWEST.
FOR FRIDAY NIGHT THROUGH SUNDAY...LOOK FOR A MID-LEVEL CLOSED LOW TO
MAKE ITS WAY ACROSS THE AREA FOR SCATTERED SHOWERS AND COOLING
TEMPERATURES.
SUNDAY NIGHT THROUGH MONDAY LOOKS DRY AND COOL AS A RIDGE OF HIGH
PRESSURE BUILDS IN FROM THE PLAINS.
SHOWER/THUNDERSTORM CHANCES RETURN TO THE AREA MONDAY NIGHT THROUGH
WEDNESDAY AS ANOTHER CLOSED MID-LEVEL LOW SYSTEM DROPS ACROSS THE
NORTHERN PLAINS INTO THE UPPER MISSISSIPPI RIVER REGION. THIS SYSTEM
WILL ALSO RESULT IN BELOW NORMAL TEMPERATURES THROUGH THIS PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED
AT 1233 PM CDT WED MAY 29 2013
THE WARM FRONT HAS PUSHED NORTH OF THE TAF SITES...WITH A WARM...
MOIST AND UNSTABLE AIRMASS OVERSPREADING SOUTHERN MN/WESTERN WI.
CLOUDS ALONG/SOUTH OF THE FRONT HAVE GENERALLY CLEARED OUT/BECOME
SCATTERED WITH THE MAIN FOCUS FOR SHRA/TSRA REMAINING WEST OF THE
AREA EARLY THIS AFTERNOON...PROVIDING A PERIOD OF IMPROVED VFR
CONDITIONS THRU MID TO LATE AFTERNOON.
MAIN FORCING/LIFT AND DEEPER MOISTURE CONTINUE TO SPREAD NORTHEAST
AND EAST ACROSS THE AREA LATER THIS AFTERNOON THRU TONIGHT INTO
THURSDAY. SHRA/TSRA CHANCES/TIMING IN THE SUMMERY AIRMASS OVER-
SPREADING THE AREA REMAIN PROBLEMATIC AFTER THE 20-23Z TIME-FRAME
THIS AFTERNOON THRU THU. APPEARS ONE ROUND OF SHRA/TSRA TO MOVE
ACROSS THE TAF SITES IN THE 20-03Z TIME PERIOD LATER TODAY.
CONFIDENCE MODERATE ON THIS ROUND. ANOTHER ROUND OF SHRA/TSRA LOOKS
TO MOVE ACROSS THE TAF SITES LATER TONIGHT/THU MORNING. GIVEN A WIDE
VARIETY OF SMALL SCALE TRIGGERS AND MODEL SOLUTIONS...CONFIDENCE
LOWER LATER TONIGHT/THU. OPTED NOT TO SPREAD EXTENSIVE PERIODS OF
TSRA/CB IN THE TAFS FOR NOW GIVEN MDT CONFIDENCE AT BEST. WILL JUST
HAVE TO PLAN ON SOME AMD/UPDATES ONCE TIMING/COVERAGE OF THE ROUNDS
OF CONVECTION BECOME CLEARER.
&&
.HYDROLOGY...TONIGHT THROUGH FRIDAY
ISSUED AT 429 PM CDT WED MAY 29 2013
PERIODS OF SHOWERS AND THUNDERSTORMS ARE EXPECTED ACROSS MUCH OF THE
REGION THROUGH FRIDAY. THE HEAVIEST RAIN IS EXPECTED TO FALL FROM
THURSDAY INTO FRIDAY. TOTAL RAINFALL FROM TODAY THROUGH FRIDAY
COULD RANGE FROM 1 TO 3 INCHES WITH LOCALLY HIGHER AMOUNTS
POSSIBLE. THIS COULD LEAD TO FLASH FLOODING AS WELL AS RISES AND
POSSIBLE FLOODING ON AREA RIVERS. A FLASH FLOOD WATCH HAS BEEN
ISSUED FOR NORTHEAST IA AND PORTIONS OF SOUTHEAST MN THROUGH THU.
THIS MAY NEED TO BE EXPANDED NORTHWARD...OR POSSIBLY EVEN EASTWARD
INTO WI...AS DETAILS OF TIMING/LOCATION OF THE CONTINUED HEAVY
RAIN THREAT BECOME CLEARER.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...FLASH FLOOD WATCH THROUGH THURSDAY EVENING FOR MNZ094>096.
IA...FLASH FLOOD WATCH THROUGH THURSDAY EVENING FOR IAZ008>011-018-
019-029-030.
&&
$$
UPDATE...AJ
SHORT TERM...DAS
LONG TERM....DAS
AVIATION.....RRS
HYDROLOGY....DAS/AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
308 PM CDT WED MAY 29 2013
.SHORT TERM...(TONIGHT THROUGH THURSDAY)
ISSUED AT 308 PM CDT WED MAY 29 2013
MAIN CONCERN IS SEVERE POTENTIAL GOING INTO THIS EVENING AND HEAVY
RAINFALL POTENTIAL THROUGH THURSDAY.
WATER VAPOR IMAGERY/RAP 500MB ANALYSIS SHOWS A DEEPENING TROUGH OF
LOW PRESSURE ACROSS THE CENTRAL ROCKIES INTO THE SOUTHERN PLAINS.
THIS IN TURN WAS DRIVING AN INCREASINGLY MOIST/UNSTABLE SOUTHERLY
SURFACE FLOW FROM THE PLAINS INTO THE UPPER MISSISSIPPI RIVER VALLEY
REGION. AT THE SURFACE LOW PRESSURE WAS LOCATED OVER SOUTHEAST CO
WITH A WARM FRONT EXTENDING NORTHEAST THROUGH IA INTO SOUTHERN WI.
CONVECTION/SOME STRONG TO SEVERE WAS FIRING ALONG/AHEAD OF THIS WARM
FRONT ON THE NOSE OF INCREASING 925-85OMB MOISTURE
TRANSPORT/INCREASING CAPE POOL. DEW POINTS ACROSS OUR AREA THIS
AFTERNOON WERE IN THE MID/UPPER 60S WITH AROUND 70 ACROSS EASTERN
IA.
LOOK FOR ONGOING SHOWER/THUNDERSTORM ACTIVITY THIS EVENING AS THE
WARM FRONT/NOSE OF RATHER INTENSE MOISTURE TRANSPORT CONTINUES TO PUSH NORTH
ACROSS THE AREA. RAP SHOWING 0-1KM MLCAPE IN THE 3000-3500J/KG WITH
INCREASING 0-3KM BULK SHEAR IN THE 25-35KT RANGE BETWEEN 4 PM AND 8
PM ACROSS PORTIONS OF NORTHEAST IA/SOUTHWEST WI. CAPE/BULK SHEAR AND
ENHANCED 0-1KM EHI VALUES WOULD FAVOR TORNADOGENESIS ALONG THE WARM
FRONT AS IT PUSHES THROUGH NORTHEAST IA/SOUTHWEST WI. WILL HAVE TO
KEEP AN EYE ON LARGE HAIL/DAMAGING WIND/TORNADIC POTENTIAL GOING INTO
EVENING. CAPE STARTS DWINDLING AFTER SUNSET...HOWEVER...MODELS
CONTINUE TO SHOW FETCH OF STRONG 925-850MB MOISTURE TRANSPORT
ADVECTING INTO OUR AREA OVERNIGHT INTO THURSDAY. THIS WILL BE AHEAD
OF A COLD FRONT PUSHING EASTWARD INTO THE CENTRAL PLAINS.
PRECIPITABLE WATER VALUES INCREASE INTO THE 1.5 TO 1.7IN RANGE. WITH
THIS IN MIND THERE WILL BE THE POTENTIAL WILL BE THERE FOR SOME
HEAVY RAINFALL. HAVE ISSUED A FLASH FLOOD WATCH FOR PORTIONS OF THE
AREA THIS EVENING THROUGH THURSDAY TO COVER THIS. SEE THE HYDROLOGY
SECTION BELOW FOR FURTHER DETAILS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 308 PM CDT WED MAY 29 2013
MAIN AXIS OF MOISTURE TRANSPORT/ENHANCED PRECIPITABLE WATER SHIFTS
EAST OF THE AREA THURSDAY NIGHT WITH A COLD FRONT LAGGING ACROSS
CENTRAL MN INTO EASTERN NEBRASKA/CENTRAL KS. SO...EXPECTING HEAVIER
RAINFALL TO TAPER OFF IN THE EVENING/OVERNIGHT FROM WEST TO EAST.
THE COLD FRONT WILL CONTINUE TO PUSH SLOWLY EAST INTO THE AREA
FRIDAY WITH INCREASING MOISTURE TRANSPORT INTO FAR SOUTHERN WI
DURING THE AFTERNOON. HAVE TAILORED SHRA/TS CHANCES WITH LIKELY
ACROSS THE SOUTH...TAPERING TO 40-50 POPS ACROSS THE NORTHWEST.
FOR FRIDAY NIGHT THROUGH SUNDAY...LOOK FOR A MID-LEVEL CLOSED LOW TO
MAKE ITS WAY ACROSS THE AREA FOR SCATTERED SHOWERS AND COOLING
TEMPERATURES.
SUNDAY NIGHT THROUGH MONDAY LOOKS DRY AND COOL AS A RIDGE OF HIGH
PRESSURE BUILDS IN FROM THE PLAINS.
SHOWER/THUNDERSTORM CHANCES RETURN TO THE AREA MONDAY NIGHT THROUGH
WEDNESDAY AS ANOTHER CLOSED MID-LEVEL LOW SYSTEM DROPS ACROSS THE
NORTHERN PLAINS INTO THE UPPER MISSISSIPPI RIVER REGION. THIS SYSTEM
WILL ALSO RESULT IN BELOW NORMAL TEMPERATURES THROUGH THIS PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED
AT 1233 PM CDT WED MAY 29 2013
THE WARM FRONT HAS PUSHED NORTH OF THE TAF SITES...WITH A WARM...
MOIST AND UNSTABLE AIRMASS OVERSPREADING SOUTHERN MN/WESTERN WI.
CLOUDS ALONG/SOUTH OF THE FRONT HAVE GENERALLY CLEARED OUT/BECOME
SCATTERED WITH THE MAIN FOCUS FOR SHRA/TSRA REMAINING WEST OF THE
AREA EARLY THIS AFTERNOON...PROVIDING A PERIOD OF IMPROVED VFR
CONDITIONS THRU MID TO LATE AFTERNOON.
MAIN FORCING/LIFT AND DEEPER MOISTURE CONTINUE TO SPREAD NORTHEAST
AND EAST ACROSS THE AREA LATER THIS AFTERNOON THRU TONIGHT INTO
THURSDAY. SHRA/TSRA CHANCES/TIMING IN THE SUMMERY AIRMASS OVER-
SPREADING THE AREA REMAIN PROBLEMATIC AFTER THE 20-23Z TIME-FRAME
THIS AFTERNOON THRU THU. APPEARS ONE ROUND OF SHRA/TSRA TO MOVE
ACROSS THE TAF SITES IN THE 20-03Z TIME PERIOD LATER TODAY.
CONFIDENCE MODERATE ON THIS ROUND. ANOTHER ROUND OF SHRA/TSRA LOOKS
TO MOVE ACROSS THE TAF SITES LATER TONIGHT/THU MORNING. GIVEN A WIDE
VARIETY OF SMALL SCALE TRIGGERS AND MODEL SOLUTIONS...CONFIDENCE
LOWER LATER TONIGHT/THU. OPTED NOT TO SPREAD EXTENSIVE PERIODS OF
TSRA/CB IN THE TAFS FOR NOW GIVEN MDT CONFIDENCE AT BEST. WILL JUST
HAVE TO PLAN ON SOME AMD/UPDATES ONCE TIMING/COVERAGE OF THE ROUNDS
OF CONVECTION BECOME CLEARER.
&&
.HYDROLOGY...TONIGHT THROUGH FRIDAY
ISSUED AT 1233 PM CDT WED MAY 29 2013
PERIODS OF SHOWERS AND THUNDERSTORMS ARE EXPECTED ACROSS MUCH OF THE
REGION THROUGH FRIDAY. THE HEAVIEST RAIN IS EXPECTED TO FALL FROM
THURSDAY INTO FRIDAY. TOTAL RAINFALL FROM TODAY THROUGH FRIDAY
COULD RANGE FROM 1 TO 3 INCHES WITH LOCALLY HIGHER AMOUNTS
POSSIBLE. THIS COULD LEAD TO FLASH FLOODING AS WELL AS RISES AND
POSSIBLE FLOODING ON AREA RIVERS. A FLASH FLOOD WATCH HAS BEEN
ISSUED FOR A PORTION OF NORTHEAST IA/SOUTHEAST MN FOR TONIGHT/THU.
THIS IS LIKELY TO BE EXPANDED WITH LATER FORECAST ISSUANCES AS
DETAILS OF TIMING/LOCATION OF THE CONTINUED HEAVY RAIN THREAT
BECOME CLEARER. PORTIONS OF ANY ADDITIONAL WATCH MAY NEED TO GO
INTO THU EVENING...ESPECIALLY IN THE WI PORTION OF THE FCST AREA.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...FLASH FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH THURSDAY
EVENING FOR MNZ094-095.
IA...FLASH FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH
THURSDAY EVENING FOR IAZ008>010-018-019-029.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION.....RRS
HYDROLOGY....DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1233 PM CDT WED MAY 29 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 356 AM CDT WED MAY 29 2013
LATEST WATER VAPOR IMAGERY CONTINUED TO SHOW A MESSY PATTERN ACROSS
THE CONUS. A LEADING SHORTWAVE...RESPONSIBLE FOR BRINGING SOME
SCATTERED RAIN SHOWERS TO THE AREA YESTERDAY...WAS MOVING ACROSS
NORTHERN LOWER MICHIGAN/EASTERN UPPER MICHIGAN. TWO MAIN SHORTWAVES
NOTED...ONE MOVING THROUGH WESTERN NEBRASKA AND ANOTHER MOVING
ACROSS NORTHERN TEXAS/WESTERN OKLAHOMA. A TROUGH WAS DIGGING INTO
THE CENTRAL ROCKIES/FOUR CORNERS REGION...ATTEMPTING TO EDGE EAST
INTO THE HIGH PLAINS. SURFACE OBSERVATIONS INDICATED A WARM FRONT
EXTENDING FROM SOUTHERN NEBRASKA NORTHEAST THROUGH SOUTHERN IOWA
INTO NORTHERN ILLINOIS.
THE WARM FRONT IS EXPECTED TO LIFT NORTH TODAY AS THE TROUGH EJECTS
NORTHEAST ACROSS THE CENTRAL PLAINS. SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO DEVELOP ALONG THE FRONT AS IT PUSHES NORTHWARD AND A
SHORTWAVE LIFTS NORTH ACROSS THE UPPER MISSISSIPPI RIVER VALLEY.
THERE IS SOME UNCERTAINTY REGARDING HOW MUCH INSTABILITY BUILDS
ALONG THE FRONT. THE NAM SUGGESTS 0-3 KM MUCAPE VALUES CLIMB INTO
THE 1500 TO 2000 J/KG RANGE THIS AFTERNOON AS WARM...MOIST AIR
SURGES NORTHWARD. THIS SEEMS A BIT AGGRESSIVE GIVEN THE ABUNDANT
CLOUD COVER IN PLACE. ALSO...THE NAM SURFACE DEWPOINTS CLIMB TO
AROUND 70. THE RUC SURFACE DEWPOINTS ARE ALSO WAY TOO HIGH
TODAY...WITH DEWPOINTS CLIMBING INTO THE MID 70S. LOWER TO MID 60S
DEW POINTS ARE MUCH MORE REALISTIC...SO THINKING SURFACE BASED
CAPE VALUES OF AROUND 1000 J/KG IS NOT OUT OF THE QUESTION...BUT
WITH ONLY WEAK 0-6 KM SHEAR. CANNOT RULE OUT AN ISOLATED SEVERE
STORM BUT OVERALL PROBABILITIES APPEAR LOW AT LEAST THROUGH MID
AFTERNOON. WILL HAVE TO KEEP A VERY CLOSE WATCH ON AREAS WEST OF
THE MISSISSIPPI RIVER WHEN THE LOW LEVEL JET INTENSIFIES THIS
EVENING AND 0-1KM SHEAR RAMPS UP. IF STORMS ARE SURFACE BASED OVER
THESE AREAS EARLY THIS EVENING...CANNOT RULE OUT AN ISOLATED
TORNADO MAINLY WEST OF A LAKE CITY...TO HARMONY TO OELWEIN LINE.
WARMER AIR ALOFT MOVES IN...CENTERED AROUND 850 MB...AND SHOULD
EFFECTIVELY CAP THE ATMOSPHERE FOR FURTHER CONVECTIVE DEVELOPMENT
AT LEAST UNTIL 850 MB MOISTURE TRANSPORT KICKS IN LATE THIS
EVENING. SHEAR IS RATHER WEAK...UNTIL THE LOW LEVEL JET GETS GOING
THIS EVENING AND FOCUSES INTO EASTERN SOUTH DAKOTA/SOUTHWEST
MINNESOTA. PLAN ON TEMPERATURES GRADUALLY WARMING THROUGH THE DAY
AS THE FRONT MOVES THROUGH WITH HIGHS TOPPING OUT IN THE UPPER
70S. A FEW LOWER TO MID 80S ARE POSSIBLE OVER PORTIONS OF
NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN. THE WARM FRONT IS
EXPECTED TO PUSH INTO FAR NORTHERN WISCONSIN THIS EVENING. 850 MB
MOISTURE TRANSPORT IS INITIALLY FOCUSES WEST OF THE FORECAST AREA
EARLY IN THE EVENING BUT THEN SHIFT EAST INTO THE AREA LATE
TONIGHT INTO EARLY THURSDAY MORNING. WILL HAVE TO KEEP A VERY
CLOSE WATCH ON HOW THIS MOISTURE TRANSPORT EVOLVES
TONIGHT...ESPECIALLY ALONG AND WEST OF THE MISSISSIPPI RIVER. AT
THIS TIME...THINKING SHOWERS AND STORMS WILL PUSH INTO AREAS WEST
OF MISSISSIPPI RIVER BEFORE SUNRISE ON THURSDAY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 356 AM CDT WED MAY 29 2013
ACTIVE SOUTHWEST FLOW ALOFT ACROSS THE FORECAST AREA WILL PRODUCE
WIDESPREAD SHOWERS AND THUNDERSTORMS ON THURSDAY. SEVERAL EMBEDDED
SHORTWAVES WILL MOVE OVER THE REGION THROUGH THE DAY WITH BROAD
MOISTURE TRANSPORT AND LIFT OVER THE REGION. A STRONGER WAVE MOVES
IN LATE THURSDAY AFTERNOON INTO THURSDAY EVENING...WITH SHOWERS
AND STORM PERSISTING. INSTABILITY IS NOT ALL THAT
IMPRESSIVE...GENERALLY IN THE 500 TO 1000 J/KG RANGE. 0-6 KM SHEAR
LOOKS TO HOVER IN THE 30 TO 40 KT RANGE SO CANNOT RULE OUT A FEW
STRONG TO SEVERE THUNDERSTORMS WITH HEAVY RAINFALL...LARGE HAIL
AND DAMAGING WINDS. THE REPEATED ROUND OF SHOWERS AND STORMS OVER
THE AREA WILL INCREASE FLOODING CONCERNS...ESPECIALLY OVER
NORTHEAST IOWA...SOUTHEAST MINNESOTA AND FAR WESTERN WISCONSIN.
RAINFALL AMOUNTS OF 1 TO 2 INCHES ARE POSSIBLE BY THURSDAY NIGHT.
THE TROUGH FINALLY CLOSES INTO AN UPPER LOW OVER WESTERN NORTH
DAKOTA. DESPITE THE WIDESPREAD SHOWERS AND STORMS ACROSS THE AREA
ON THURSDAY...THE WARM SOUTHERLY FLOW WILL ALLOW HIGH TEMPERATURES
TO WARM INTO THE MID TO UPPER 70S. THE UPPER LOW STARTS TO DRIFT
SOUTHEAST LATE THURSDAY NIGHT INTO FRIDAY AS A VIGOROUS SHORTWAVE
PUSHES THROUGH THE PLAINS AND LIFTS NORTHEAST INTO THE UPPER AND
MID MISSISSIPPI RIVER VALLEY. AS THIS WAVE MOVES IN ON FRIDAY 0-6
KM BULK SHEAR REALLY RAMPS UP FRIDAY AFTERNOON...45 TO 55 KTS
ACROSS MUCH OF THE FORECAST AREA. HOWEVER...A BOUNDARY PUSHES
ACROSS THE AREA LATE THURSDAY NIGHT INTO FRIDAY MORNING PUSHING
THE BEST INSTABILITY JUST SOUTHEAST OF THE FORECAST AREA..ACROSS
PORTIONS OF FAR EASTERN IOWA THROUGH NORTHERN ILLINOIS AND
SOUTHEAST WISCONSIN. CANNOT RULE OUT SEVERE STORMS ON FRIDAY BUT
THE HIGHER CHANCES LOOK TO BE SOUTHEAST OF THE AREA. PORTIONS OF
FAR NORTHEAST IOWA...AND EXTREME SOUTHWEST WISCONSIN COULD BE
IMPACTED. WILL HAVE TO KEEP A VERY CLOSE WATCH OVER THE NEXT FEW
FORECAST MODELS RUNS TO SEE EXACTLY WHERE THE BOUNDARY WILL SET
UP. SHOWER AND THUNDERSTORMS CHANCES CONTINUE INTO SATURDAY AS THE
UPPER LOW DRIFTS ACROSS WISCONSIN. RAIN CHANCES WILL CONTINUE INTO
SUNDAY AS A TROUGH REMAINS OVER THE GREAT LAKES REGION. AN
UNSEASONABLY COLD AIRMASS MOVES INTO THE REGION SUNDAY INTO MONDAY
WITH STANDARDIZED 850 MB TEMPERATURE ANOMALIES OF -1.5. WOULD
EXPECT OVERNIGHT LOWS ON SUNDAY TO FALL INTO THE UPPER 30S OVER
FAR NORTHERN WISCONSIN...FALLING INTO THE LOWER 40S ACROSS CENTRAL
WISCONSIN AND THE UPPER 40S ACROSS NORTHEAST IOWA. LOCATIONS ALONG
AND NORTH OF THE INTERSTATE 94 CORRIDOR COULD SEE SOME AREAS OF
FROST. HIGH PRESSURE SLIDES EAST OF THE REGION LATE MONDAY NIGHT
INTO TUESDAY AS A TROUGH PUSHES THROUGH THE NORTHERN PLAINS. A
WARM FRONT LOOKS TO LIFT INTO THE UPPER MISSISSIPPI RIVER VALLEY
LATE MONDAY NIGHT INTO TUESDAY BRINGING A CHANCE OF SHOWERS AND
THUNDERSTORMS TO THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED
AT 1233 PM CDT WED MAY 29 2013
THE WARM FRONT HAS PUSHED NORTH OF THE TAF SITES...WITH A WARM...
MOIST AND UNSTABLE AIRMASS OVERSPREADING SOUTHERN MN/WESTERN WI.
CLOUDS ALONG/SOUTH OF THE FRONT HAVE GENERALLY CLEARED OUT/BECOME
SCATTERED WITH THE MAIN FOCUS FOR SHRA/TSRA REMAINING WEST OF THE
AREA EARLY THIS AFTERNOON...PROVIDING A PERIOD OF IMPROVED VFR
CONDITIONS THRU MID TO LATE AFTERNOON.
MAIN FORCING/LIFT AND DEEPER MOISTURE CONTINUE TO SPREAD NORTHEAST
AND EAST ACROSS THE AREA LATER THIS AFTERNOON THRU TONIGHT INTO
THURSDAY. SHRA/TSRA CHANCES/TIMING IN THE SUMMERY AIRMASS OVER-
SPREADING THE AREA REMAIN PROBLEMATIC AFTER THE 20-23Z TIME-FRAME
THIS AFTERNOON THRU THU. APPEARS ONE ROUND OF SHRA/TSRA TO MOVE
ACROSS THE TAF SITES IN THE 20-03Z TIME PERIOD LATER TODAY.
CONFIDENCE MODERATE ON THIS ROUND. ANOTHER ROUND OF SHRA/TSRA LOOKS
TO MOVE ACROSS THE TAF SITES LATER TONIGHT/THU MORNING. GIVEN A WIDE
VARIETY OF SMALL SCALE TRIGGERS AND MODEL SOLUTIONS...CONFIDENCE
LOWER LATER TONIGHT/THU. OPTED NOT TO SPREAD EXTENSIVE PERIODS OF
TSRA/CB IN THE TAFS FOR NOW GIVEN MDT CONFIDENCE AT BEST. WILL JUST
HAVE TO PLAN ON SOME AMD/UPDATES ONCE TIMING/COVERAGE OF THE ROUNDS
OF CONVECTION BECOME CLEARER.
&&
.HYDROLOGY...TODAY THROUGH FRIDAY
ISSUED AT 1233 PM CDT WED MAY 29 2013
PERIODS OF SHOWERS AND THUNDERSTORMS ARE EXPECTED ACROSS MUCH OF THE
REGION THROUGH FRIDAY. THE HEAVIEST RAIN IS EXPECTED TO FALL FROM
THURSDAY INTO FRIDAY. TOTAL RAINFALL FROM TODAY THROUGH FRIDAY
COULD RANGE FROM 1 TO 3 INCHES WITH LOCALLY HIGHER AMOUNTS
POSSIBLE. THIS COULD LEAD TO FLASH FLOODING AS WELL AS RISES AND
POSSIBLE FLOODING ON AREA RIVERS. A FLASH FLOOD WATCH HAS BEEN
ISSUED FOR A PORTION OF NORTHEAST IA/SOUTHEAST MN FOR TONIGHT/THU.
THIS IS LIKELY TO BE EXPANDED WITH LATER FORECAST ISSUANCES AS
DETAILS OF TIMING/LOCATION OF THE CONTINUED HEAVY RAIN THREAT
BECOME CLEARER. PORTIONS OF ANY ADDITIONAL WATCH MAY NEED TO GO
INTO THU EVENING...ESPECIALLY IN THE WI PORTION OF THE FCST AREA.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...FLASH FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH THURSDAY
EVENING FOR MNZ094-095.
IA...FLASH FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH THURSDAY
EVENING FOR IAZ008>010-018-019-029.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM....WETENKAMP
AVIATION.....RRS
HYDROLOGY....WETENKAMP/RRS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
600 AM CDT WED MAY 29 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 356 AM CDT WED MAY 29 2013
LATEST WATER VAPOR IMAGERY CONTINUED TO SHOW A MESSY PATTERN ACROSS
THE CONUS. A LEADING SHORTWAVE...RESPONSIBLE FOR BRINGING SOME
SCATTERED RAIN SHOWERS TO THE AREA YESTERDAY...WAS MOVING ACROSS
NORTHERN LOWER MICHIGAN/EASTERN UPPER MICHIGAN. TWO MAIN SHORTWAVES
NOTED...ONE MOVING THROUGH WESTERN NEBRASKA AND ANOTHER MOVING
ACROSS NORTHERN TEXAS/WESTERN OKLAHOMA. A TROUGH WAS DIGGING INTO
THE CENTRAL ROCKIES/FOUR CORNERS REGION...ATTEMPTING TO EDGE EAST
INTO THE HIGH PLAINS. SURFACE OBSERVATIONS INDICATED A WARM FRONT
EXTENDING FROM SOUTHERN NEBRASKA NORTHEAST THROUGH SOUTHERN IOWA
INTO NORTHERN ILLINOIS.
THE WARM FRONT IS EXPECTED TO LIFT NORTH TODAY AS THE TROUGH EJECTS
NORTHEAST ACROSS THE CENTRAL PLAINS. SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO DEVELOP ALONG THE FRONT AS IT PUSHES NORTHWARD AND A
SHORTWAVE LIFTS NORTH ACROSS THE UPPER MISSISSIPPI RIVER VALLEY.
THERE IS SOME UNCERTAINTY REGARDING HOW MUCH INSTABILITY BUILDS
ALONG THE FRONT. THE NAM SUGGESTS 0-3 KM MUCAPE VALUES CLIMB INTO
THE 1500 TO 2000 J/KG RANGE THIS AFTERNOON AS WARM...MOIST AIR
SURGES NORTHWARD. THIS SEEMS A BIT AGGRESSIVE GIVEN THE ABUNDANT
CLOUD COVER IN PLACE. ALSO...THE NAM SURFACE DEWPOINTS CLIMB TO
AROUND 70. THE RUC SURFACE DEWPOINTS ARE ALSO WAY TOO HIGH
TODAY...WITH DEWPOINTS CLIMBING INTO THE MID 70S. LOWER TO MID 60S
DEW POINTS ARE MUCH MORE REALISTIC...SO THINKING SURFACE BASED
CAPE VALUES OF AROUND 1000 J/KG IS NOT OUT OF THE QUESTION...BUT
WITH ONLY WEAK 0-6 KM SHEAR. CANNOT RULE OUT AN ISOLATED SEVERE
STORM BUT OVERALL PROBABILITIES APPEAR LOW AT LEAST THROUGH MID
AFTERNOON. WILL HAVE TO KEEP A VERY CLOSE WATCH ON AREAS WEST OF
THE MISSISSIPPI RIVER WHEN THE LOW LEVEL JET INTENSIFIES THIS
EVENING AND 0-1KM SHEAR RAMPS UP. IF STORMS ARE SURFACE BASED OVER
THESE AREAS EARLY THIS EVENING...CANNOT RULE OUT AN ISOLATED
TORNADO MAINLY WEST OF A LAKE CITY...TO HARMONY TO OELWEIN LINE.
WARMER AIR ALOFT MOVES IN...CENTERED AROUND 850 MB...AND SHOULD
EFFECTIVELY CAP THE ATMOSPHERE FOR FURTHER CONVECTIVE DEVELOPMENT
AT LEAST UNTIL 850 MB MOISTURE TRANSPORT KICKS IN LATE THIS
EVENING. SHEAR IS RATHER WEAK...UNTIL THE LOW LEVEL JET GETS GOING
THIS EVENING AND FOCUSES INTO EASTERN SOUTH DAKOTA/SOUTHWEST
MINNESOTA. PLAN ON TEMPERATURES GRADUALLY WARMING THROUGH THE DAY
AS THE FRONT MOVES THROUGH WITH HIGHS TOPPING OUT IN THE UPPER
70S. A FEW LOWER TO MID 80S ARE POSSIBLE OVER PORTIONS OF
NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN. THE WARM FRONT IS
EXPECTED TO PUSH INTO FAR NORTHERN WISCONSIN THIS EVENING. 850 MB
MOISTURE TRANSPORT IS INITIALLY FOCUSES WEST OF THE FORECAST AREA
EARLY IN THE EVENING BUT THEN SHIFT EAST INTO THE AREA LATE
TONIGHT INTO EARLY THURSDAY MORNING. WILL HAVE TO KEEP A VERY
CLOSE WATCH ON HOW THIS MOISTURE TRANSPORT EVOLVES
TONIGHT...ESPECIALLY ALONG AND WEST OF THE MISSISSIPPI RIVER. AT
THIS TIME...THINKING SHOWERS AND STORMS WILL PUSH INTO AREAS WEST
OF MISSISSIPPI RIVER BEFORE SUNRISE ON THURSDAY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 356 AM CDT WED MAY 29 2013
ACTIVE SOUTHWEST FLOW ALOFT ACROSS THE FORECAST AREA WILL PRODUCE
WIDESPREAD SHOWERS AND THUNDERSTORMS ON THURSDAY. SEVERAL EMBEDDED
SHORTWAVES WILL MOVE OVER THE REGION THROUGH THE DAY WITH BROAD
MOISTURE TRANSPORT AND LIFT OVER THE REGION. A STRONGER WAVE MOVES
IN LATE THURSDAY AFTERNOON INTO THURSDAY EVENING...WITH SHOWERS
AND STORM PERSISTING. INSTABILITY IS NOT ALL THAT
IMPRESSIVE...GENERALLY IN THE 500 TO 1000 J/KG RANGE. 0-6 KM SHEAR
LOOKS TO HOVER IN THE 30 TO 40 KT RANGE SO CANNOT RULE OUT A FEW
STRONG TO SEVERE THUNDERSTORMS WITH HEAVY RAINFALL...LARGE HAIL
AND DAMAGING WINDS. THE REPEATED ROUND OF SHOWERS AND STORMS OVER
THE AREA WILL INCREASE FLOODING CONCERNS...ESPECIALLY OVER
NORTHEAST IOWA...SOUTHEAST MINNESOTA AND FAR WESTERN WISCONSIN.
RAINFALL AMOUNTS OF 1 TO 2 INCHES ARE POSSIBLE BY THURSDAY NIGHT.
THE TROUGH FINALLY CLOSES INTO AN UPPER LOW OVER WESTERN NORTH
DAKOTA. DESPITE THE WIDESPREAD SHOWERS AND STORMS ACROSS THE AREA
ON THURSDAY...THE WARM SOUTHERLY FLOW WILL ALLOW HIGH TEMPERATURES
TO WARM INTO THE MID TO UPPER 70S. THE UPPER LOW STARTS TO DRIFT
SOUTHEAST LATE THURSDAY NIGHT INTO FRIDAY AS A VIGOROUS SHORTWAVE
PUSHES THROUGH THE PLAINS AND LIFTS NORTHEAST INTO THE UPPER AND
MID MISSISSIPPI RIVER VALLEY. AS THIS WAVE MOVES IN ON FRIDAY 0-6
KM BULK SHEAR REALLY RAMPS UP FRIDAY AFTERNOON...45 TO 55 KTS
ACROSS MUCH OF THE FORECAST AREA. HOWEVER...A BOUNDARY PUSHES
ACROSS THE AREA LATE THURSDAY NIGHT INTO FRIDAY MORNING PUSHING
THE BEST INSTABILITY JUST SOUTHEAST OF THE FORECAST AREA..ACROSS
PORTIONS OF FAR EASTERN IOWA THROUGH NORTHERN ILLINOIS AND
SOUTHEAST WISCONSIN. CANNOT RULE OUT SEVERE STORMS ON FRIDAY BUT
THE HIGHER CHANCES LOOK TO BE SOUTHEAST OF THE AREA. PORTIONS OF
FAR NORTHEAST IOWA...AND EXTREME SOUTHWEST WISCONSIN COULD BE
IMPACTED. WILL HAVE TO KEEP A VERY CLOSE WATCH OVER THE NEXT FEW
FORECAST MODELS RUNS TO SEE EXACTLY WHERE THE BOUNDARY WILL SET
UP. SHOWER AND THUNDERSTORMS CHANCES CONTINUE INTO SATURDAY AS THE
UPPER LOW DRIFTS ACROSS WISCONSIN. RAIN CHANCES WILL CONTINUE INTO
SUNDAY AS A TROUGH REMAINS OVER THE GREAT LAKES REGION. AN
UNSEASONABLY COLD AIRMASS MOVES INTO THE REGION SUNDAY INTO MONDAY
WITH STANDARDIZED 850 MB TEMPERATURE ANOMALIES OF -1.5. WOULD
EXPECT OVERNIGHT LOWS ON SUNDAY TO FALL INTO THE UPPER 30S OVER
FAR NORTHERN WISCONSIN...FALLING INTO THE LOWER 40S ACROSS CENTRAL
WISCONSIN AND THE UPPER 40S ACROSS NORTHEAST IOWA. LOCATIONS ALONG
AND NORTH OF THE INTERSTATE 94 CORRIDOR COULD SEE SOME AREAS OF
FROST. HIGH PRESSURE SLIDES EAST OF THE REGION LATE MONDAY NIGHT
INTO TUESDAY AS A TROUGH PUSHES THROUGH THE NORTHERN PLAINS. A
WARM FRONT LOOKS TO LIFT INTO THE UPPER MISSISSIPPI RIVER VALLEY
LATE MONDAY NIGHT INTO TUESDAY BRINGING A CHANCE OF SHOWERS AND
THUNDERSTORMS TO THE AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 600 AM CDT WED MAY 29 2013
AREAS OF FOG WERE FOUND ACROSS THE REGION EARLY THIS MORNING...WITH
VSBYS BOBBING UP AND DOWN. KRST HAD DROPPED TO 1/4SM AND SHOULD STAY
THERE FOR A COUPLE HOURS BEFORE MIXING HELPS IMPROVE THE VSBY AND
CIG HEIGHTS BY MID/LATE MORNING. KLSE HAS STAYED OUT OF THE SUB 1SM
BR FOR NOW...AND THINK THAT SHOULD PERSIST. CIGS HAVE FLUCTUATED
ABOVE AND BELOW 1 KFT THOUGH...AND THIS TREND WILL LIKELY PERSIST
INTO MID MORNING BEFORE MIXING IMPROVES CONDITIONS HERE TOO.
A WARM FRONT WILL ADVANCE NORTHWARD ACROSS THE REGION TODAY...LIKELY
IN THE 17-18Z TIME FRAME AT KRST/KLSE. THIS COULD BE SLOWED...OR
SPED UP...DEPENDING ON CLEARING AND ON GOING CONVECTION TO THE
SOUTH. CIGS WILL IMPROVE INTO THE VFR RANGE WITH THE PASSAGE OF THE
FRONT...BUT SHRA/TS WILL ALSO INCREASE AROUND AND JUST SOUTH OF IT.
MEANWHILE...AN UPPER AIR DISTURBANCE COULD SPIN OUT OF THE PLAINS
AND ACROSS THE REGION BY LATE AFTERNOON/EARLY EVENING. THIS WOULD
TAP INTO INCREASED INSTABILITY THAT WILL DEVELOP IN THE WAKE OF THE
WARM FRONT...INCREASING THE SHRA/TS POTENTIAL.
THE PCPN CHANCES ARE PROBLEMATIC TO NARROW DOWN TODAY AND TONIGHT
WITH BOUNDARIES AND OTHER MESO FEATURES ALL POTENTIALLY SERVING AS A
FOCUS FOR SHRA/TS. WILL HIGHLIGHT THE FAVORED PERIOD ALONG AND JUST
SOUTH OF THE FRONT FOR THE AFTERNOON HOURS FOR NOW...BUT THIS WILL
HAVE TO BE REFINED LATER IN THE DAY AS WHERE THE PCPN WILL DEVELOP
AND MOVE BECOMES CLEARER.
SHOULD GET A FEW HOURS RAIN FREE TONIGHT...BUT SHRA/TS WILL BECOME
WIDESPREAD FOR THE REGION ON THU AHEAD OF AN APPROACHING COLD FRONT
AND WITHIN THE MAIN AVENUE OF LOW LEVEL MOISTURE TRANSPORT. A RETURN
TO MVFR CONDITIONS IS LIKELY.
&&
.HYDROLOGY...TODAY THROUGH FRIDAY
ISSUED AT 356 AM CDT WED MAY 29 2013
PERIODS OF SHOWERS AND THUNDERSTORMS ARE EXPECTED ACROSS MUCH OF THE
REGION THROUGH FRIDAY. THE HEAVIEST RAIN IS EXPECTED TO FALL FROM
THURSDAY INTO FRIDAY. TOTAL RAINFALL FROM TODAY THROUGH FRIDAY
COULD RANGE FROM 1 TO 3 INCHES WITH LOCALLY HIGHER AMOUNTS
POSSIBLE. THIS COULD LEAD TO FLASH FLOODING AS WELL AS RISES AND
POSSIBLE FLOODING ON AREA RIVERS. A FLASH FLOOD WATCH MAY BE
NEEDED FOR THE AREA IF DETAILS BECOME CLEARER ON WHERE AND WHEN
THE HEAVIEST RAIN WILL FALL.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM....WETENKAMP
AVIATION.....RIECK
HYDROLOGY....WETENKAMP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
356 AM CDT WED MAY 29 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 356 AM CDT WED MAY 29 2013
LATEST WATER VAPOR IMAGERY CONTINUED TO SHOW A MESSY PATTERN ACROSS
THE CONUS. A LEADING SHORTWAVE...RESPONSIBLE FOR BRINGING SOME
SCATTERED RAIN SHOWERS TO THE AREA YESTERDAY...WAS MOVING ACROSS
NORTHERN LOWER MICHIGAN/EASTERN UPPER MICHIGAN. TWO MAIN SHORTWAVES
NOTED...ONE MOVING THROUGH WESTERN NEBRASKA AND ANOTHER MOVING
ACROSS NORTHERN TEXAS/WESTERN OKLAHOMA. A TROUGH WAS DIGGING INTO
THE CENTRAL ROCKIES/FOUR CORNERS REGION...ATTEMPTING TO EDGE EAST
INTO THE HIGH PLAINS. SURFACE OBSERVATIONS INDICATED A WARM FRONT
EXTENDING FROM SOUTHERN NEBRASKA NORTHEAST THROUGH SOUTHERN IOWA
INTO NORTHERN ILLINOIS.
THE WARM FRONT IS EXPECTED TO LIFT NORTH TODAY AS THE TROUGH EJECTS
NORTHEAST ACROSS THE CENTRAL PLAINS. SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO DEVELOP ALONG THE FRONT AS IT PUSHES NORTHWARD AND A
SHORTWAVE LIFTS NORTH ACROSS THE UPPER MISSISSIPPI RIVER VALLEY.
THERE IS SOME UNCERTAINTY REGARDING HOW MUCH INSTABILITY BUILDS
ALONG THE FRONT. THE NAM SUGGESTS 0-3 KM MUCAPE VALUES CLIMB INTO
THE 1500 TO 2000 J/KG RANGE THIS AFTERNOON AS WARM...MOIST AIR
SURGES NORTHWARD. THIS SEEMS A BIT AGGRESSIVE GIVEN THE ABUNDANT
CLOUD COVER IN PLACE. ALSO...THE NAM SURFACE DEWPOINTS CLIMB TO
AROUND 70. THE RUC SURFACE DEWPOINTS ARE ALSO WAY TOO HIGH
TODAY...WITH DEWPOINTS CLIMBING INTO THE MID 70S. LOWER TO MID 60S
DEW POINTS ARE MUCH MORE REALISTIC...SO THINKING SURFACE BASED
CAPE VALUES OF AROUND 1000 J/KG IS NOT OUT OF THE QUESTION...BUT
WITH ONLY WEAK 0-6 KM SHEAR. CANNOT RULE OUT AN ISOLATED SEVERE
STORM BUT OVERALL PROBABILITIES APPEAR LOW AT LEAST THROUGH MID
AFTERNOON. WILL HAVE TO KEEP A VERY CLOSE WATCH ON AREAS WEST OF
THE MISSISSIPPI RIVER WHEN THE LOW LEVEL JET INTENSIFIES THIS
EVENING AND 0-1KM SHEAR RAMPS UP. IF STORMS ARE SURFACE BASED OVER
THESE AREAS EARLY THIS EVENING...CANNOT RULE OUT AN ISOLATED
TORNADO MAINLY WEST OF A LAKE CITY...TO HARMONY TO OELWEIN LINE.
WARMER AIR ALOFT MOVES IN...CENTERED AROUND 850 MB...AND SHOULD
EFFECTIVELY CAP THE ATMOSPHERE FOR FURTHER CONVECTIVE DEVELOPMENT
AT LEAST UNTIL 850 MB MOISTURE TRANSPORT KICKS IN LATE THIS
EVENING. SHEAR IS RATHER WEAK...UNTIL THE LOW LEVEL JET GETS GOING
THIS EVENING AND FOCUSES INTO EASTERN SOUTH DAKOTA/SOUTHWEST
MINNESOTA. PLAN ON TEMPERATURES GRADUALLY WARMING THROUGH THE DAY
AS THE FRONT MOVES THROUGH WITH HIGHS TOPPING OUT IN THE UPPER
70S. A FEW LOWER TO MID 80S ARE POSSIBLE OVER PORTIONS OF
NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN. THE WARM FRONT IS
EXPECTED TO PUSH INTO FAR NORTHERN WISCONSIN THIS EVENING. 850 MB
MOISTURE TRANSPORT IS INITIALLY FOCUSES WEST OF THE FORECAST AREA
EARLY IN THE EVENING BUT THEN SHIFT EAST INTO THE AREA LATE
TONIGHT INTO EARLY THURSDAY MORNING. WILL HAVE TO KEEP A VERY
CLOSE WATCH ON HOW THIS MOISTURE TRANSPORT EVOLVES
TONIGHT...ESPECIALLY ALONG AND WEST OF THE MISSISSIPPI RIVER. AT
THIS TIME...THINKING SHOWERS AND STORMS WILL PUSH INTO AREAS WEST
OF MISSISSIPPI RIVER BEFORE SUNRISE ON THURSDAY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 356 AM CDT WED MAY 29 2013
ACTIVE SOUTHWEST FLOW ALOFT ACROSS THE FORECAST AREA WILL PRODUCE
WIDESPREAD SHOWERS AND THUNDERSTORMS ON THURSDAY. SEVERAL EMBEDDED
SHORTWAVES WILL MOVE OVER THE REGION THROUGH THE DAY WITH BROAD
MOISTURE TRANSPORT AND LIFT OVER THE REGION. A STRONGER WAVE MOVES
IN LATE THURSDAY AFTERNOON INTO THURSDAY EVENING...WITH SHOWERS
AND STORM PERSISTING. INSTABILITY IS NOT ALL THAT
IMPRESSIVE...GENERALLY IN THE 500 TO 1000 J/KG RANGE. 0-6 KM SHEAR
LOOKS TO HOVER IN THE 30 TO 40 KT RANGE SO CANNOT RULE OUT A FEW
STRONG TO SEVERE THUNDERSTORMS WITH HEAVY RAINFALL...LARGE HAIL
AND DAMAGING WINDS. THE REPEATED ROUND OF SHOWERS AND STORMS OVER
THE AREA WILL INCREASE FLOODING CONCERNS...ESPECIALLY OVER
NORTHEAST IOWA...SOUTHEAST MINNESOTA AND FAR WESTERN WISCONSIN.
RAINFALL AMOUNTS OF 1 TO 2 INCHES ARE POSSIBLE BY THURSDAY NIGHT.
THE TROUGH FINALLY CLOSES INTO AN UPPER LOW OVER WESTERN NORTH
DAKOTA. DESPITE THE WIDESPREAD SHOWERS AND STORMS ACROSS THE AREA
ON THURSDAY...THE WARM SOUTHERLY FLOW WILL ALLOW HIGH TEMPERATURES
TO WARM INTO THE MID TO UPPER 70S. THE UPPER LOW STARTS TO DRIFT
SOUTHEAST LATE THURSDAY NIGHT INTO FRIDAY AS A VIGOROUS SHORTWAVE
PUSHES THROUGH THE PLAINS AND LIFTS NORTHEAST INTO THE UPPER AND
MID MISSISSIPPI RIVER VALLEY. AS THIS WAVE MOVES IN ON FRIDAY 0-6
KM BULK SHEAR REALLY RAMPS UP FRIDAY AFTERNOON...45 TO 55 KTS
ACROSS MUCH OF THE FORECAST AREA. HOWEVER...A BOUNDARY PUSHES
ACROSS THE AREA LATE THURSDAY NIGHT INTO FRIDAY MORNING PUSHING
THE BEST INSTABILITY JUST SOUTHEAST OF THE FORECAST AREA..ACROSS
PORTIONS OF FAR EASTERN IOWA THROUGH NORTHERN ILLINOIS AND
SOUTHEAST WISCONSIN. CANNOT RULE OUT SEVERE STORMS ON FRIDAY BUT
THE HIGHER CHANCES LOOK TO BE SOUTHEAST OF THE AREA. PORTIONS OF
FAR NORTHEAST IOWA...AND EXTREME SOUTHWEST WISCONSIN COULD BE
IMPACTED. WILL HAVE TO KEEP A VERY CLOSE WATCH OVER THE NEXT FEW
FORECAST MODELS RUNS TO SEE EXACTLY WHERE THE BOUNDARY WILL SET
UP. SHOWER AND THUNDERSTORMS CHANCES CONTINUE INTO SATURDAY AS THE
UPPER LOW DRIFTS ACROSS WISCONSIN. RAIN CHANCES WILL CONTINUE INTO
SUNDAY AS A TROUGH REMAINS OVER THE GREAT LAKES REGION. AN
UNSEASONABLY COLD AIRMASS MOVES INTO THE REGION SUNDAY INTO MONDAY
WITH STANDARDIZED 850 MB TEMPERATURE ANOMALIES OF -1.5. WOULD
EXPECT OVERNIGHT LOWS ON SUNDAY TO FALL INTO THE UPPER 30S OVER
FAR NORTHERN WISCONSIN...FALLING INTO THE LOWER 40S ACROSS CENTRAL
WISCONSIN AND THE UPPER 40S ACROSS NORTHEAST IOWA. LOCATIONS ALONG
AND NORTH OF THE INTERSTATE 94 CORRIDOR COULD SEE SOME AREAS OF
FROST. HIGH PRESSURE SLIDES EAST OF THE REGION LATE MONDAY NIGHT
INTO TUESDAY AS A TROUGH PUSHES THROUGH THE NORTHERN PLAINS. A
WARM FRONT LOOKS TO LIFT INTO THE UPPER MISSISSIPPI RIVER VALLEY
LATE MONDAY NIGHT INTO TUESDAY BRINGING A CHANCE OF SHOWERS AND
THUNDERSTORMS TO THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1141 PM CDT TUE MAY 28 2013
A COUPLE OF ISSUES FOR THE FORECAST.
THE FIRST IS ON THE LOW CLOUDS WHICH ARE STUCK OVER THE TAF
SITES...DUE TO A COMBINATION OF THE RECENT WET WEATHER AND A RIDGE
OF HIGH PRESSURE IN PLACE PROVIDING NO MIXING. NIGHTTIME COOLING
SHOULD ALLOW CEILINGS AND VISIBILITIES TO LOWER DURING THE NEXT
COUPLE HOURS...WITH KRST POSSIBLY SEEING LIFR/VLIFR CONDITIONS IN
THE 10-13Z PERIOD. THE VALLEY LOCATION OF KLSE SHOULD PREVENT
VISIBILITIES DROPPING BELOW MVFR AND CEILINGS BELOW IFR. AFTER
13Z...INCREASING SOUTH TO SOUTHEAST WINDS PLUS DAYTIME HEATING
WILL ALLOW CEILINGS AND VISIBILITIES TO QUICKLY RISE AT BOTH
SITES...AT LEAST TO MVFR BY LATE MORNING AND VFR EARLY IN THE
AFTERNOON.
THE NEXT CONCERN IS ON SHOWER AND THUNDERSTORM CHANCES. A WARM
FRONT NEAR I-70 IN KANSAS AND MISSOURI IS FORECAST TO LIFT INTO
THE TAF SITES EARLY THIS AFTERNOON. FORCING ON THIS FRONT COMBINED
WITH DAYTIME HEATING SHOULD ALLOW FOR SHOWERS AND THUNDERSTORMS
ALONG THIS FRONT. VISIBILITIES COULD BE REDUCED BUT HARD TO PIN
THAT DOWN AT EITHER TAF SITES RIGHT NOW...SINCE A WIDESPREAD BAND
OF SHOWERS AND THUNDERSTORMS IS NOT EXPECTED ON THE FRONT. BRIEF
HEAVY RAIN AND LIGHTNING APPEARS TO BE THE MAIN HAZARDS WITH THE
STORMS. THESE SHOWERS AND THUNDERSTORMS SHOULD END AROUND 00Z
WITH THE PASSAGE OF THE FRONT.
THE FINAL CONCERN IS ON WINDS. DAYTIME MIXING BEHIND THE WARM
FRONT SHOULD ALLOW SOUTHERLY GUSTS OF 20-30 KT TO DEVELOP DURING
THE AFTERNOON AT BOTH TAF SITES...STRONGEST AT KRST. THERE MAY
EVEN BE A PERIOD OF GREATER THAN 30 KT GUSTS AT KRST IN THE 21-00Z
PERIOD. ANTICIPATING WINDS TO STAY GUSTY AT KRST THROUGH THE
EVENING AS A LOW LEVEL JET CROSSES. SHOULD GUSTS DROP OFF...LOW
LEVEL WIND SHEAR WOULD OCCUR. THE LOW LEVEL JET IS NOT AS STRONG
AT KLSE...SO EVEN THOUGH GUSTS SHOULD DROP OFF THERE BEING IN THE
VALLEY...HAVE NOT INCLUDED LOW LEVEL WIND SHEAR AT THIS TIME.
&&
.HYDROLOGY...TODAY THROUGH FRIDAY
ISSUED AT 356 AM CDT WED MAY 29 2013
PERIODS OF SHOWERS AND THUNDERSTORMS ARE EXPECTED ACROSS MUCH OF THE
REGION THROUGH FRIDAY. THE HEAVIEST RAIN IS EXPECTED TO FALL FROM
THURSDAY INTO FRIDAY. TOTAL RAINFALL FROM TODAY THROUGH FRIDAY
COULD RANGE FROM 1 TO 3 INCHES WITH LOCALLY HIGHER AMOUNTS
POSSIBLE. THIS COULD LEAD TO FLASH FLOODING AS WELL AS RISES AND
POSSIBLE FLOODING ON AREA RIVERS. A FLASH FLOOD WATCH MAY BE
NEEDED FOR THE AREA IF DETAILS BECOME CLEARER ON WHERE AND WHEN
THE HEAVIEST RAIN WILL FALL.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...AJ
HYDROLOGY...WETENKAMP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1141 PM CDT TUE MAY 28 2013
.UPDATE...
ISSUED AT 935 PM CDT TUE MAY 28 2013
CONVECTION AS ANTICIPATED INITIATED AND PERSISTS FROM KANSAS INTO
NORTHERN MISSOURI...SOUTHERN IOWA AND NORTHERN ILLINOIS. THIS
CONVECTION FORMED ON OR JUST TO THE NORTH OF A SURFACE WARM
FRONTAL BOUNDARY...WHICH HAS BEEN SLOWLY SHIFTING BACK SOUTH DUE
TO CONVECTIVE OUTFLOWS. 850MB RADAR AND VWP DATA SHOWED SOUTHWEST
35-45 KT WINDS FROM EASTERN KANSAS INTO SOUTHERN WISCONSIN...
PUMPING GULF OF MEXICO MOISTURE INTO THIS CONVECTION. THE FORECAST
AREA LIES ON THE SUBSIDENT SIDE OF THE CONVECTION...AS WELL AS IN
RIDGING BUILDING IN BEHIND A SHORTWAVE IN NORTHERN WISCONSIN. AS A
RESULT...DRY CONDITIONS ARE OCCURRING OVER THE FORECAST AREA.
NUMEROUS HRRR RUNS...INCLUDING THE LATEST AVAILABLE 29.00Z
HRRR...CONTINUE TO DEPICT A DRY FORECAST FOR THE AREA THROUGH 12Z
AND EVEN BEYOND. THE 28.00Z NSSL WRF-ARW ALSO DEPICTS A DRY
FORECAST...WITH BOTH MODELS SUGGESTING ALL CONVECTION STAYS HUNG
UP ACROSS SOUTHERN IOWA OR POINTS SOUTH. THIS MAKES SENSE GIVEN
THE DRIFT SOUTH OF THE WARM FRONT FROM OUTFLOWS...THOUGH THE DRIFT
SOUTH MAY BEGIN TO STOP SOON WITH UPPER RIDGING BUILDING ACROSS
THE CENTRAL AND SOUTHERN PLAINS. ADDITIONALLY...UPPER RIDGING
BUILDING IN BEHIND THE SHORTWAVE HEADING INTO NORTHERN WISCONSIN
SHOULD PROVIDE ADDED SUBSIDENCE. THUS...WENT WITH A DRY FORECAST
THROUGH 12Z.
WILL DEFINITELY HAVE TO WATCH THE FOG SITUATION OVERNIGHT.
TEMP/DEWPOINT SPREADS ARE ALREADY FAIRLY LOW...ESPECIALLY NORTH
OF I-90. SO FAR VISIBILITIES ARE BEHAVING...STAYING AT 4-5 MILES
OR HIGHER. COMBINATION OF BLOWOFF FROM CONVECTION TO THE SOUTH AND
LOW CLOUDS SHOULD PRECLUDE GOOD RADIATIONAL COOLING TO FORM FOG.
THUS...TO GET DENSE FOG...WE WILL NEED CEILINGS TO LOWER.
CONFIDENCE IS TOO LOW TO PUT OUT A DENSE FOG ADVISORY NOW...BUT
CANNOT RULE OUT ONE NEEDED LATER.
&&
.SHORT TERM...(TONIGHT THROUGH WEDNESDAY NIGHT)
ISSUED AT 325 PM CDT TUE MAY 28 2013
MAIN FORECAST CONCERNS THIS PERIOD...SHRA/TSRA CHANCES THRU THE
PERIOD...RAIN AMOUNTS/SEVERE THREAT WED AFTERNOON/EVENING.
18Z DATA ANALYSIS HAD A WARM/STATIONARY FRONT NEAR THE WI/IL
BORDER...SOUTHWEST TO A LOW OVER NORTHEAST NM. WV IMAGERY AND EVEN
IR/VIS IMAGERY DEPICTED A RATHER VIGOROUS MID LEVEL SHORTWAVE MOVING
EAST ACROSS SOUTHWEST MN. NORTH OF THE FRONT AND AHEAD OF THE
SHORTWAVE...LOW CLOUDS...PATCHY BR/-DZ PERSISTED ACROSS MUCH OF
MN/WI. ACROSS MUCH OF IA...IN THE WAKE OF A SHORTWAVE THAT PASSED
EARLY THIS MORNING...CLOUDS WERE A LITTLE THINNER WITH SOME
SUNSHINE IN THE SUBSIDENCE BEHIND THAT SHORTWAVE. ACROSS MUCH OF
MN/WI WHERE THE LOW CLOUDS/LACK OF SUNSHINE PERSISTED...MID-DAY
TEMPS REMAINED COOL...IN THE 50S TO LOW 60S.
SOME MINOR DIFFERENCES NOTED WITH 28.12Z MODEL INITIALIZATIONS...
BUT THE BIG PICTURE OF THE SOLUTIONS REMAINS QUITE SIMILAR THRU WED
NIGHT AND INTO FRIDAY. THERE WILL BE PERIODS/BREAKS FROM THE RAIN BUT
BETWEEN TONIGHT AND FRI ANOTHER COUPLE ROUNDS OF HEAVIER/MORE
WIDESPREAD RAIN LOOK TO SPREAD ACROSS THE AREA. DPROG/DT OF 500MB
HGTS AT 28.12Z SHOWED THE MODEL RUNS OF 26.12Z AND 27.12Z VERIFIED
QUITE WELL ACROSS NOAM/EASTERN PAC WHILE TRENDING TOWARD A TIGHTER...
COMMON CONSENSUS. SOLUTIONS CONTINUE TO CONVERGE TOWARD A TIGHTER...
COMMON CONSENSUS TONIGHT/WED AS HGTS RISE OVER THE REGION AND STRONG
TROUGHING DIGS THRU THE ROCKIES. IMPROVING CONSENSUS WED NIGHT AS
THE STRONG TROUGHING MOVES INTO THE CENTRAL CONUS. CHECK OF OBS
VS. MODEL DATA AT 18Z SHOWED THEM TO BE REASONABLE WITH THE CENTRAL
CONUS MASS FIELDS...THOUGH NAM/GEM WERE A BIT HIGH WITH SFC DEW
POINTS OVER MUCH OF IL. A BLEND OF THE MODELS LOOKED BEST WITH THE
12-18Z PRECIP OVER THE UPPER MIDWEST. NO CLEAR MODEL FAVORITE AND
PREFERRED A MODEL/ENSEMBLE CONSENSUS. SHORT-TERM FCST CONFIDENCE ON
THE GOOD SIDE THIS CYCLE.
FOR THE SHORT TERM...SOUTHWEST MN SHORTWAVE WILL PASS THIS EVENING...
TAKING SOME OF THE DEEPER MOISTURE/FORCING/LIFT WITH IT. LITTLE IN TH
WAY OF FORCING/LIFT SEEN FOR SHRA/TSRA CHANCES AFTER ABOUT 03Z. SOME
WEAK LOWER LEVEL WARM ADVECTION CONTINUES BUT MOST OF THIS LOOKS TO
GO INTO WARMING/RISING MID LEVEL HGTS BEHIND THE SHORTWAVE. LEFT SOME
SMALL -SHRA/ISOLATED TSRA CHANCES IN THE FCST GRIDS TONIGHT...MAINLY
ACROSS THE SOUTHEAST HALF OF THE FCST AREA WHERE SOME 500-1000 J/KG
MU CAPE LOOKS TO REMAIN THRU THE NIGHT...AND BLENDS WELL WITH
NEIGHBORING GRIDS. VIS IMAGERY SHOWS THERE SHOULD BE SOME DECREASE OF
CLOUDS IN THE WAKE OF THE SHORTWAVE FOR LATER THIS EVENING/OVERNIGHT.
WITH THE VERY MOIST BOUNDARY LAYER AND LIGHT WINDS...AREAS/PATCHY
FOG SHOULD FORM...ESPECIALLY WHERE CLOUDS/LIGHT PRECIP HELD TEMPS
DOWN TODAY.
THE FRONTAL BOUNDARY GETS A PUSH NORTHWARD ON WED AS THE ROCKIES
TROUGHING MOVES INTO THE PLAINS AND DEEPER/STRONGER SOUTHERLY FLOW
DEVELOPS OVER THE MID/UPPER MS VALLEY. PW VALUES IN THE AIRMASS
BEING PUSHED INTO/OVER THE WARM FRONT IN THE 1.5 TO 1.75 INCH RANGE
ON NOSE OF 35-50KT 850MB JET/MOISTURE TRANSPORT/THETA-E CONVERGENCE.
1K-2K J/KG MU CAPE INDICATED AS WELL IN THIS AIRMASS. RAISED SHRA/
TSRA CHANCES FOR WED INTO THE 70-80 PERCENT RANGE AS THE WARM FRONT
LIFTS NORTH INTO THE AREA. INCREASING WIND FLOW SHOULD KEEP ANY TSRA
PROGRESSIVE ON WED. WITH A BREAK TONIGHT AND PLENTY OF MODEL DETAIL
DIFFERENCES WITH PRECIP AMOUNTS WED...HELD OFF ON RE-ISSUING A FLASH
FLOOD WATCH ON WED FOR NOW. AREA LOOKS TO GET ANOTHER BREAK FROM THE
MORE WIDESPREAD SHRA/TSRA WED NIGHT WITH THE WARM FRONT LIFTING
NORTH OF THE AREA AND THE PLAINS LOW COLD FRONT AND NEXT ROUND OF
STRONGER/LARGER SCALE FORCING REMAINING WELL WEST OF THE AREA.
ONE OF THE BIGGER CONCERNS IS HIGHS ON WED. MUCH OF THE GUIDANCE IS
STILL PUSHING WED HIGHS INTO THE UPPER 70S/LOW 80S. WITH SHRA/TSRA
LIKELY TO DELAY THE WARM FRONT LIFTING THRU THE AREA...PLUS PLENTY
OF CLOUDS AND THE SHRA/TSRA...LOWERED HIGHS FOR WED MOSTLY INTO THE
MID 70S...AND EVEN THIS MAY STILL BE 5-10F TOO WARM. HIGHS WED WILL
IMPACT HOW MUCH CAPE DEVELOPS OVER THE AREA AND ANY SEVERE STORM
THREAT. PROXIMITY OF THE WARM FRONT AND ENHANCED LOW LEVEL HELICITY
MAY ALLOW SEVERE STORMS TO DEVELOP...IF THEY CAN GET ROOTED IN THE
BOUNDARY LAYER. SEE SWODY2 FOR MORE DETAILS OF THE WED SEVERE THREAT.
FOR NOW WED HIGHS IN THE MID 70S BLEND WELL WITH NEIGHBORING GRIDS.
USED A BLEND OF GUIDANCE LOWS FOR TONIGHT/WED NIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 325 PM CDT TUE MAY 28 2013
FORECAST CONCERNS THU INTO FRI ARE SHRA/TSRA CHANCES AND POTENTIAL
FOR HEAVY RAINS/SEVERE STORMS AS THE COLD FRONT MOVES THRU THE AREA.
MODELS STAY IN REASONABLE AGREEMENT THU/FRI AS THE PLAINS TROUGH
LIFTS NORTH THU..THEN DEVELOPS A 500MB LOW OVER THE DAKOTAS BY FRI.
RATHER ENERGETIC SYSTEM DEVELOPS A STRONG SFC LOW OVER THE DAKOTAS
BY MID-DAY THU. SFC SYSTEM OCCLUDES AND PUSHES THE COLD FRONT TOWARD
THE AREA THU THEN INTO THE AREA THU NIGHT. THIS INTO THE AIRMASS WITH
1K-2K J/KG MU CAPE AND 1.5 TO 1.75 INCH PW VALUES...ALONG WITH
STRENGTHENING WIND FIELDS. SWODY3 QUITE REASONABLE AT THIS TIME.
POTENTIAL REMAINS FOR REPEAT STRONGER...HEAVY RAIN PRODUCING TSRA
THU/THU EVENING AND APPEARS ANOTHER FLASH FLOOD WATCH WILL BE NEEDED
FOR THIS TIME PERIOD. WILL CONTINUE ESFARX ADDRESSING THIS POTENTIAL
FOR NOW AND GIVE CREWS TONIGHT/WED A COUPLE MORE MODEL RUNS TO
DETAIL WHERE ANY FLASH FLOOD WATCH MAY BE NEEDED. RAISED SHRA/TSRA
CHANCES FOR THU/THU EVENING INTO THE 70-80 PERCENT RANGE FOR MUCH OF
THE AREA. WITH THE MID LEVEL TROUGH AXIS REMAINING WEST OF THE AREA
AND WHAT LOOKS TO BE A SECOND SFC COLD FRONT/TROUGH TO PUSH TOWARD
THE AREA...CONTINUED SHRA/TSRA CHANCES FRI/FRI NIGHT LOOK GOOD. GIVEN
SOME TIMING DIFFERENCES...USED THE MODEL/ENSEMBLE CONSENSUS GUIDANCE
FOR HIGHS/LOWS THU THRU FRI NIGHT.
MEDIUM RANGE MODEL RUNS OF 28.00Z AND 28.12Z IN REASONABLY GOOD
AGREEMENT WITH EACH OTHER AND OFFER AN IMPROVING CONSENSUS OVER
THEIR PREVIOUS RUNS FOR SAT THRU MON. THIS AS THE MID TROUGH
SWINGS ACROSS THE UPPER MIDWEST SAT/SAT NIGHT AND SHORTWAVE
RIDGING BUILDS IN BY LATER SUN AND FOR MON. LESSER CONSISTENCY BY
TUE...BUT A SIGNAL FOR ANOTHER STRONGER SHORTWAVE TROUGH TO BE
MOVING THRU THE NORTHERN ROCKIES... PUSHING THE SHORTWAVE RIDGE
AXIS INTO THE EASTERN GREAT LAKES. FCST CONFIDENCE AVERAGE TO GOOD
SAT-MON THEN AVERAGE BY TUE.
WITH THE MID LEVEL TROUGH AXIS STILL WEST OF THE AREA SAT...COOL/
COOLING 850- 500MB TEMPS/STEEPER MID LEVEL LAPSE RATES AND PW
VALUES REMAINING AROUND AN INCH...SHRA/TSRA CHANCES LOOKING TO
LINGER ON SAT. TROUGH AXIS PASSES LATE SAT NIGHT/EARLY SUN FOR
WHAT LOOKS TO BE A MUCH NEEDED DRIER PERIOD SUN AND ESPECIALLY MON
AS CAN HIGH PRESSURE AND THE SHORTWAVE RIDGING ALOFT BUILD EAST
INTO THE WESTERN GREAT LAKES.
NEXT TROUGH CROSSING THE ROCKIES MON NIGHT/TUE DEVELOPS LOW
PRESSURE IN THE CENTRAL/NORTHERN PLAINS...WITH INCREASING SOUTH/
SOUTHWEST FLOW...PW VALUES AND MOISTURE TRANSPORT/THETA-E CONVERGENCE
INTO THE UPPER MIDWEST ON TUE. SHRA/TSRA CHANCES LOOKING TO ALREADY
RETURN ON TUE. MODEL/ENSEMBLE CONSENSUS FOR HIGHS/LOWS SAT-TUE
APPEAR WELL TRENDED WITH TEMPS REMAINING BELOW TO NEAR NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1141 PM CDT TUE MAY 28 2013
A COUPLE OF ISSUES FOR THE FORECAST.
THE FIRST IS ON THE LOW CLOUDS WHICH ARE STUCK OVER THE TAF
SITES...DUE TO A COMBINATION OF THE RECENT WET WEATHER AND A RIDGE
OF HIGH PRESSURE IN PLACE PROVIDING NO MIXING. NIGHTTIME COOLING
SHOULD ALLOW CEILINGS AND VISIBILITIES TO LOWER DURING THE NEXT
COUPLE HOURS...WITH KRST POSSIBLY SEEING LIFR/VLIFR CONDITIONS IN
THE 10-13Z PERIOD. THE VALLEY LOCATION OF KLSE SHOULD PREVENT
VISIBILITIES DROPPING BELOW MVFR AND CEILINGS BELOW IFR. AFTER
13Z...INCREASING SOUTH TO SOUTHEAST WINDS PLUS DAYTIME HEATING
WILL ALLOW CEILINGS AND VISIBILITIES TO QUICKLY RISE AT BOTH
SITES...AT LEAST TO MVFR BY LATE MORNING AND VFR EARLY IN THE
AFTERNOON.
THE NEXT CONCERN IS ON SHOWER AND THUNDERSTORM CHANCES. A WARM
FRONT NEAR I-70 IN KANSAS AND MISSOURI IS FORECAST TO LIFT INTO
THE TAF SITES EARLY THIS AFTERNOON. FORCING ON THIS FRONT COMBINED
WITH DAYTIME HEATING SHOULD ALLOW FOR SHOWERS AND THUNDERSTORMS
ALONG THIS FRONT. VISIBILITIES COULD BE REDUCED BUT HARD TO PIN
THAT DOWN AT EITHER TAF SITES RIGHT NOW...SINCE A WIDESPREAD BAND
OF SHOWERS AND THUNDERSTORMS IS NOT EXPECTED ON THE FRONT. BRIEF
HEAVY RAIN AND LIGHTNING APPEARS TO BE THE MAIN HAZARDS WITH THE
STORMS. THESE SHOWERS AND THUNDERSTORMS SHOULD END AROUND 00Z
WITH THE PASSAGE OF THE FRONT.
THE FINAL CONCERN IS ON WINDS. DAYTIME MIXING BEHIND THE WARM
FRONT SHOULD ALLOW SOUTHERLY GUSTS OF 20-30 KT TO DEVELOP DURING
THE AFTERNOON AT BOTH TAF SITES...STRONGEST AT KRST. THERE MAY
EVEN BE A PERIOD OF GREATER THAN 30 KT GUSTS AT KRST IN THE 21-00Z
PERIOD. ANTICIPATING WINDS TO STAY GUSTY AT KRST THROUGH THE
EVENING AS A LOW LEVEL JET CROSSES. SHOULD GUSTS DROP OFF...LOW
LEVEL WIND SHEAR WOULD OCCUR. THE LOW LEVEL JET IS NOT AS STRONG
AT KLSE...SO EVEN THOUGH GUSTS SHOULD DROP OFF THERE BEING IN THE
VALLEY...HAVE NOT INCLUDED LOW LEVEL WIND SHEAR AT THIS TIME.
&&
.HYDROLOGY...TONIGHT THROUGH FRIDAY
ISSUED AT 325 PM CDT TUE MAY 28 2013
A COUPLE ROUNDS OF MORE WIDESPREAD SHRA/TSRA ARE EXPECTED FROM
WEDNESDAY THROUGH FRIDAY AND A FLASH FLOOD WATCH WILL LIKELY BE
NEEDED DURING SOME PORTION OF THIS TIME-FRAME. THE FIRST ROUND COMES
WED AS A WARM FRONT LIFTS INTO/ACROSS THE AREA...WITH WHAT LOOKS TO
BE MORE PROGRESSIVE SHRA/TSRA AND MOST RAIN AMOUNTS IN THE 0.25 TO
0.5 INCH RANGE. THE SECOND MORE WIDESPREAD ROUND OF SHRA/TSRA MOVES
ACROSS THE AREA THU/THU EVENING...AHEAD OF A COLD FRONT. THERE IS
MORE POTENTIAL FOR REPEAT...HEAVY RAIN PRODUCING TSRA THU/THU
EVENING GIVEN THE WIND FIELDS AND SLOWER MOVING FRONT. RAIN AMOUNTS
OF 1 TO 2 INCHES...WITH LOCALLY HEAVIER AMOUNTS...ARE QUITE POSSIBLE
THU/THU NIGHT. A FLASH FLOOD WATCH WILL MORE LIKELY BE NEEDED FOR
PORTIONS OF THE AREA WITH THIS ROUND OF SHRA/TSRA. LARGER RIVERS WILL
ALSO SEE CONTINUED RISES AND POSSIBLE FLOODING THIS WEEK WITH THE
PROLONGED PERIOD OF COOL/WET WEATHER. CONTINUE TO MONITOR RIVER
FORECASTS AND STATEMENTS CLOSELY THIS WEEK.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...AJ
SHORT TERM...RRS
LONG TERM....RRS
AVIATION...AJ
HYDROLOGY....RRS
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1157 PM MDT TUE MAY 28 2013
.UPDATE...
ISSUED AT 1008 PM MDT TUE MAY 28 2013
WENT AHEAD AND LET THE SEVERE THUNDERSTORM WATCH EXPIRE ON TIME AT
10 PM THIS EVENING FOR THE PANHANDLE. THERE ARE STILL SOME
THUNDERSTORMS OVER THE SOUTHERN PANHANDLE COMING IN FROM NORTHEAST
COLORADO...BUT THE ATMOSPHERE HAS BEEN WORKED OVER BY NUMEROUS
THUNDERSTORMS...SO DO NOT EXPECT STORMS TO BECOME SEVERE AGAIN.
WILL NEED TO WATCH EASTERN LARAMIE COUNTY LATE THIS EVENING AS
STORMS MOVE NORTH OUT OF COLORADO. LATEST RUC CAPE HAS AROUND 600
J/KG WITH CLOSE TO 900 J/KG UP NEAR BORDEAUX. KEPT THE RELATIVELY
HIGH POPS...40 PERCENT OR SO...FOR THE OVERNIGHT HOURS.
FRONT/DRYLINE PUSHES EAST INTO CENTRAL NEBRASKA BY LATE MORNING.
SEVERE THUNDERSTORMS SHOULD BE WELL EAST OF THE FORECAST AREA FOR
WEDNESDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY EVENING) ISSUED AT
247 PM MDT TUE MAY 28 2013
CURRENT KCYS RADAR LOOP SHOWS THUNDERSTORMS JUST STARTING TO
DEVELOP ACROSS THE HIGH PLAINS OF SOUTHEAST WYOMING AND INTO
WESTERN NEBRASKA. THERE IS STILL A SLIGHT CHANCE OF SEVERE
THUNDERSTORMS LATE THIS AFTERNOON THROUGH TONIGHT...BUT WITH HIGH
LEVEL CLOUDS PUSHING ACROSS THE EASTERN PLAINS FROM THIS
MORNING...CHANCES ARE A LITTLE LESS THAN EARLIER ANTICIPATED.
COVERAGE OF SHOWERS AND THUNDERSTORMS WILL INCREASE THROUGH THIS
AFTERNOON WITH SOME MODERATE TO HIGH RAINFALL AMOUNTS POSSIBLE
OVER FAR EASTERN WYOMING AND WESTERN NEBRASKA...WHERE LOCAL
AMOUNTS MAY BE AROUND 1 INCH. MAIN THREATS FROM THESE
THUNDERSTORMS WILL BE HAIL...GUSTY WINDS...AND FREQUENT LIGHTNING.
OFF AND ON SHOWERS AND TSTORMS WILL CONTINUE THROUGH TONIGHT ACROSS
THE HIGH PLAINS WITH THE BEST CHANCE ACROSS WESTERN NEBRASKA. THIS
ACTIVITY WILL BE ASSOCIATED WITH THE TROUGH AXIS BEGINNING TO PUSH
ACROSS THE ROCKIES TONIGHT AS IT BECOMES NEGATIVELY TILTED.
THUNDERSTORM POTENTIAL WILL BE LESS ON WEDNESDAY AS COOLER AIR
MOVES INTO THE AREA...ALTHOUGH LOCATIONS EAST OF THE
NEBRASKA/WYOMING BORDER HAVE THE BEST POTENTIAL TO SEE STRONG OR
SEVERE STORMS AS THE TROUGH AXIS WILL BE RIGHT OVER SOUTHEAST
WYOMING WEDNESDAY AFTERNOON. FORECAST FOR SOUTHEAST WYOMING WILL
BE TRICKY WITH THE TROUGH AXIS OVERHEAD AND DOWNSLOPE WINDS JUST
BEHIND THE TROUGH. THE NAM AND GEM SHOW RAIN SHOWERS AND EMBEDDED
THUNDER ACROSS SOUTHEAST WYOMING WITH SOME PRETTY GOOD QPF AMOUNTS
WHILE THE GFS AND ECMWF ARE ON THE DRY SIDE WITH LOW DEWPOINTS.
KEPT THE HIGHEST POP FROM NIOBRARA COUNTY SOUTHEAST INTO THE
NORTHERN PANHANDLE OF NEBRASKA. BELIEVE IT WILL BE TOUGH TO AVOID
CONVECTIVE ACTIVITY EVEN ACROSS SOUTHEAST WYOMING...SO INCREASED
POP BETWEEN 30 TO 60 PERCENT ALONG I25 AND I80 AS WELL.
PRECIPITATION WILL PUSH NORTH AS THE TROUGH BECOMES A CLOSED LOW
NORTHEAST OF THE FORECAST AREA OVER THE DAKOTAS. EXPECT DRIER AIR
TO PUSH INTO THE SOUTHERN HALF OF THE FORECAST AREA ALONG I80
WEDNESDAY NIGHT AND THURSDAY. INCREASED TEMPERATURES ON THURSDAY
AND BELIEVE IT WILL BE A LITTLE BIT WARMER COMPARED TO WEDNESDAY
DUE TO DOWNSLOPE WINDS AND ADIABATIC WARMING. TEMPERATURES WILL BE
IN THE 60S TO LOW 70S OVER MOST OF THE AREA WITH PERHAPS MID TO
UPPER 50S ACROSS THE HIGH VALLEYS WEST OF THE LARAMIE RANGE.
.LONG TERM...(FRIDAY THROUGH TUESDAY) ISSUED AT 220 PM MDT TUE
MAY 28 2013
WINDY AND A LITTLE COOLER CONDITIONS FOR FRIDAY AS SFC/UPPER LOW
MOVE SLOWLY EAST OVER THE DAKOTAS. MAIN DIFFICULTY WILL BE HOW MUCH
WRAP AROUND SHOWERS PROGRESS SOUTH INTO THE CWA. BEST CHANCES OVER
THE NORTH AND HAVE TAILORED POPS THIS WAY. NEXT PUSH OF COOLER AIR
WILL SINK OVER THE AREA LATE FRIDAY COOLING THINGS A LITTLE MORE
FOR SATURDAY ALONG WITH WIDELY SCATTERED SHOWERS...POSSIBLY A
LITTLE MORE WIDESPREAD. DRY AND WARMER CONDITIONS RETURN SUNDAY
AND MONDAY AS A SHORT UPPER RIDGE MOVES BY. UPPER TROF THEN
SETTLES OVER THE PACIFIC NW EARLY NEXT WEEK WITH SW FLOW ALOFT
BECOMING ESTABLISHED OVER THE CWA BY LATE MONDAY. CHANCES FOR
WIDELY SCTD SHOWERS AND TSTRMS INCREASE A BIT TUESDAY AS MOISTURE
AND INSTABILITY INCREASE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY EVENING)
ISSUED AT 1152 PM MDT TUE MAY 28 2013
ISOLATED TO SCATTERED SHOWERS WILL CONTINUE ACROSS MAINLY THE
NEBRASKA PANHANDLE THROUGH AROUND 10Z. THERE COULD BE SOME GUSTY
AND ERRATIC WINDS WITH THE STRONGER STORMS. MODELS HAVE SHOWERS
OVER PORTIONS OF SOUTHEAST WY BETWEEN AROUND 09Z AND MID-MORNING.
THIS ACTIVITY SHIFTS EASTWARD INTO THE PANHANDLE DURING THE
AFTERNOON...AND ISOLATED THUNDERSTORMS WILL BE POSSIBLE OVER THE
NEBRASKA SITES WITH MORE INSTABILITY. OUTSIDE OF SOME LOCALIZED
MVFR CIGS...VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE TAF
PERIOD.
&&
.FIRE WEATHER...
ISSUED AT 155 PM MDT TUE MAY 28 2013
CHANCES FOR MORE WIDESPREAD RAINFALL AND WETTING RAINS WILL
INCREASE DURING THE NEXT 12 TO 48 HOURS AS A PACIFIC STORM SYSTEM
MOVES ACROSS THE CENTRAL ROCKIES AND ADJACENT PLAINS. FUELS IN
GREEN UP STAGE...COOLER TEMPERATURES AND HIGHER RELATIVE
HUMIDITIES WILL RESULT IN NO FIRE WEATHER CONCERNS THROUGH THE END
OF THE WEEK. WARMER AND DRIER CONDITIONS WILL RETURN EARLY NEXT
WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...CLAYCOMB
SHORT TERM...TJT
LONG TERM...RE
AVIATION...FINCH
FIRE WEATHER...TJT
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1037 PM MDT TUE MAY 28 2013
.UPDATE...
ISSUED AT 1008 PM MDT TUE MAY 28 2013
WENT AHEAD AND LET THE SEVERE THUNDERSTORM WATCH EXPIRE ON TIME AT
10 PM THIS EVENING FOR THE PANHANDLE. THERE ARE STILL SOME
THUNDERSTORMS OVER THE SOUTHERN PANHANDLE COMING IN FROM NORTHEAST
COLORADO...BUT THE ATMOSPHERE HAS BEEN WORKED OVER BY NUMEROUS
THUNDERSTORMS...SO DO NOT EXPECT STORMS TO BECOME SEVERE AGAIN.
WILL NEED TO WATCH EASTERN LARAMIE COUNTY LATE THIS EVENING AS
STORMS MOVE NORTH OUT OF COLORADO. LATEST RUC CAPE HAS AROUND 600
J/KG WITH CLOSE TO 900 J/KG UP NEAR BORDEAUX. KEPT THE RELATIVELY
HIGH POPS...40 PERCENT OR SO...FOR THE OVERNIGHT HOURS.
FRONT/DRYLINE PUSHES EAST INTO CENTRAL NEBRASKA BY LATE MORNING.
SEVERE THUNDERSTORMS SHOULD BE WELL EAST OF THE FORECAST AREA FOR
WEDNESDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY EVENING) ISSUED AT
247 PM MDT TUE MAY 28 2013
CURRENT KCYS RADAR LOOP SHOWS THUNDERSTORMS JUST STARTING TO
DEVELOP ACROSS THE HIGH PLAINS OF SOUTHEAST WYOMING AND INTO
WESTERN NEBRASKA. THERE IS STILL A SLIGHT CHANCE OF SEVERE
THUNDERSTORMS LATE THIS AFTERNOON THROUGH TONIGHT...BUT WITH HIGH
LEVEL CLOUDS PUSHING ACROSS THE EASTERN PLAINS FROM THIS
MORNING...CHANCES ARE A LITTLE LESS THAN EARLIER ANTICIPATED.
COVERAGE OF SHOWERS AND THUNDERSTORMS WILL INCREASE THROUGH THIS
AFTERNOON WITH SOME MODERATE TO HIGH RAINFALL AMOUNTS POSSIBLE
OVER FAR EASTERN WYOMING AND WESTERN NEBRASKA...WHERE LOCAL
AMOUNTS MAY BE AROUND 1 INCH. MAIN THREATS FROM THESE
THUNDERSTORMS WILL BE HAIL...GUSTY WINDS...AND FREQUENT LIGHTNING.
OFF AND ON SHOWERS AND TSTORMS WILL CONTINUE THROUGH TONIGHT ACROSS
THE HIGH PLAINS WITH THE BEST CHANCE ACROSS WESTERN NEBRASKA. THIS
ACTIVITY WILL BE ASSOCIATED WITH THE TROUGH AXIS BEGINNING TO PUSH
ACROSS THE ROCKIES TONIGHT AS IT BECOMES NEGATIVELY TILTED.
THUNDERSTORM POTENTIAL WILL BE LESS ON WEDNESDAY AS COOLER AIR
MOVES INTO THE AREA...ALTHOUGH LOCATIONS EAST OF THE
NEBRASKA/WYOMING BORDER HAVE THE BEST POTENTIAL TO SEE STRONG OR
SEVERE STORMS AS THE TROUGH AXIS WILL BE RIGHT OVER SOUTHEAST
WYOMING WEDNESDAY AFTERNOON. FORECAST FOR SOUTHEAST WYOMING WILL
BE TRICKY WITH THE TROUGH AXIS OVERHEAD AND DOWNSLOPE WINDS JUST
BEHIND THE TROUGH. THE NAM AND GEM SHOW RAIN SHOWERS AND EMBEDDED
THUNDER ACROSS SOUTHEAST WYOMING WITH SOME PRETTY GOOD QPF AMOUNTS
WHILE THE GFS AND ECMWF ARE ON THE DRY SIDE WITH LOW DEWPOINTS.
KEPT THE HIGHEST POP FROM NIOBRARA COUNTY SOUTHEAST INTO THE
NORTHERN PANHANDLE OF NEBRASKA. BELIEVE IT WILL BE TOUGH TO AVOID
CONVECTIVE ACTIVITY EVEN ACROSS SOUTHEAST WYOMING...SO INCREASED
POP BETWEEN 30 TO 60 PERCENT ALONG I25 AND I80 AS WELL.
PRECIPITATION WILL PUSH NORTH AS THE TROUGH BECOMES A CLOSED LOW
NORTHEAST OF THE FORECAST AREA OVER THE DAKOTAS. EXPECT DRIER AIR
TO PUSH INTO THE SOUTHERN HALF OF THE FORECAST AREA ALONG I80
WEDNESDAY NIGHT AND THURSDAY. INCREASED TEMPERATURES ON THURSDAY
AND BELIEVE IT WILL BE A LITTLE BIT WARMER COMPARED TO WEDNESDAY
DUE TO DOWNSLOPE WINDS AND ADIABATIC WARMING. TEMPERATURES WILL BE
IN THE 60S TO LOW 70S OVER MOST OF THE AREA WITH PERHAPS MID TO
UPPER 50S ACROSS THE HIGH VALLEYS WEST OF THE LARAMIE RANGE.
.LONG TERM...(FRIDAY THROUGH TUESDAY) ISSUED AT 220 PM MDT TUE
MAY 28 2013
WINDY AND A LITTLE COOLER CONDITIONS FOR FRIDAY AS SFC/UPPER LOW
MOVE SLOWLY EAST OVER THE DAKOTAS. MAIN DIFFICULTY WILL BE HOW MUCH
WRAP AROUND SHOWERS PROGRESS SOUTH INTO THE CWA. BEST CHANCES OVER
THE NORTH AND HAVE TAILORED POPS THIS WAY. NEXT PUSH OF COOLER AIR
WILL SINK OVER THE AREA LATE FRIDAY COOLING THINGS A LITTLE MORE
FOR SATURDAY ALONG WITH WIDELY SCATTERED SHOWERS...POSSIBLY A
LITTLE MORE WIDESPREAD. DRY AND WARMER CONDITIONS RETURN SUNDAY
AND MONDAY AS A SHORT UPPER RIDGE MOVES BY. UPPER TROF THEN
SETTLES OVER THE PACIFIC NW EARLY NEXT WEEK WITH SW FLOW ALOFT
BECOMING ESTABLISHED OVER THE CWA BY LATE MONDAY. CHANCES FOR
WIDELY SCTD SHOWERS AND TSTRMS INCREASE A BIT TUESDAY AS MOISTURE
AND INSTABILITY INCREASE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY EVENING)
ISSUED AT 1032 PM MDT TUE MAY 28 2013
THROUGH 15Z...AREAS OF IFR AT CHADRON...ALLIANCE AND SIDNEY IN
FOG AND LOW CLOUDS. VFR PREVAILS ELSEWHERE...WITH ISOLATED SHOWERS
AND THUNDERSTORMS ACROSS WESTERN NEBRASKA.
AFTER 19Z...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS
PRODUCING LOCALIZED MVFR ALONG WITH GUSTY AND ERRATIC WINDS...
WITH VFR PREVAILING. WINDS GUSTING 25 TO 35 KNOTS THROUGH 01Z.
&&
.FIRE WEATHER...
ISSUED AT 155 PM MDT TUE MAY 28 2013
CHANCES FOR MORE WIDESPREAD RAINFALL AND WETTING RAINS WILL
INCREASE DURING THE NEXT 12 TO 48 HOURS AS A PACIFIC STORM SYSTEM
MOVES ACROSS THE CENTRAL ROCKIES AND ADJACENT PLAINS. FUELS IN
GREEN UP STAGE...COOLER TEMPERATURES AND HIGHER RELATIVE
HUMIDITIES WILL RESULT IN NO FIRE WEATHER CONCERNS THROUGH THE END
OF THE WEEK. WARMER AND DRIER CONDITIONS WILL RETURN EARLY NEXT
WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...CLAYCOMB
SHORT TERM...TJT
LONG TERM...RE
AVIATION...RUBIN
FIRE WEATHER...TJT
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1027 PM MDT TUE MAY 28 2013
.UPDATE...
ISSUED AT 1008 PM MDT TUE MAY 28 2013
WENT AHEAD AND LET THE SEVERE THUNDERSTORM WATCH EXPIRE ON TIME AT
10 PM THIS EVENING FOR THE PANHANDLE. THERE ARE STILL SOME
THUNDERSTORMS OVER THE SOUTHERN PANHANDLE COMING IN FROM NORTHEAST
COLORADO...BUT THE ATMOSPHERE HAS BEEN WORKED OVER BY NUMEROUS
THUNDERSTORMS...SO DO NOT EXPECT STORMS TO BECOME SEVERE AGAIN.
WILL NEED TO WATCH EASTERN LARAMIE COUNTY LATE THIS EVENING AS
STORMS MOVE NORTH OUT OF COLORADO. LATEST RUC CAPE HAS AROUND 600
J/KG WITH CLOSE TO 900 J/KG UP NEAR BORDEAUX. KEPT THE RELATIVELY
HIGH POPS...40 PERCENT OR SO...FOR THE OVERNIGHT HOURS.
FRONT/DRYLINE PUSHES EAST INTO CENTRAL NEBRASKA BY LATE MORNING.
SEVERE THUNDERSTORMS SHOULD BE WELL EAST OF THE FORECAST AREA FOR
WEDNESDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY EVENING) ISSUED AT
247 PM MDT TUE MAY 28 2013
CURRENT KCYS RADAR LOOP SHOWS THUNDERSTORMS JUST STARTING TO
DEVELOP ACROSS THE HIGH PLAINS OF SOUTHEAST WYOMING AND INTO
WESTERN NEBRASKA. THERE IS STILL A SLIGHT CHANCE OF SEVERE
THUNDERSTORMS LATE THIS AFTERNOON THROUGH TONIGHT...BUT WITH HIGH
LEVEL CLOUDS PUSHING ACROSS THE EASTERN PLAINS FROM THIS
MORNING...CHANCES ARE A LITTLE LESS THAN EARLIER ANTICIPATED.
COVERAGE OF SHOWERS AND THUNDERSTORMS WILL INCREASE THROUGH THIS
AFTERNOON WITH SOME MODERATE TO HIGH RAINFALL AMOUNTS POSSIBLE
OVER FAR EASTERN WYOMING AND WESTERN NEBRASKA...WHERE LOCAL
AMOUNTS MAY BE AROUND 1 INCH. MAIN THREATS FROM THESE
THUNDERSTORMS WILL BE HAIL...GUSTY WINDS...AND FREQUENT LIGHTNING.
OFF AND ON SHOWERS AND TSTORMS WILL CONTINUE THROUGH TONIGHT ACROSS
THE HIGH PLAINS WITH THE BEST CHANCE ACROSS WESTERN NEBRASKA. THIS
ACTIVITY WILL BE ASSOCIATED WITH THE TROUGH AXIS BEGINNING TO PUSH
ACROSS THE ROCKIES TONIGHT AS IT BECOMES NEGATIVELY TILTED.
THUNDERSTORM POTENTIAL WILL BE LESS ON WEDNESDAY AS COOLER AIR
MOVES INTO THE AREA...ALTHOUGH LOCATIONS EAST OF THE
NEBRASKA/WYOMING BORDER HAVE THE BEST POTENTIAL TO SEE STRONG OR
SEVERE STORMS AS THE TROUGH AXIS WILL BE RIGHT OVER SOUTHEAST
WYOMING WEDNESDAY AFTERNOON. FORECAST FOR SOUTHEAST WYOMING WILL
BE TRICKY WITH THE TROUGH AXIS OVERHEAD AND DOWNSLOPE WINDS JUST
BEHIND THE TROUGH. THE NAM AND GEM SHOW RAIN SHOWERS AND EMBEDDED
THUNDER ACROSS SOUTHEAST WYOMING WITH SOME PRETTY GOOD QPF AMOUNTS
WHILE THE GFS AND ECMWF ARE ON THE DRY SIDE WITH LOW DEWPOINTS.
KEPT THE HIGHEST POP FROM NIOBRARA COUNTY SOUTHEAST INTO THE
NORTHERN PANHANDLE OF NEBRASKA. BELIEVE IT WILL BE TOUGH TO AVOID
CONVECTIVE ACTIVITY EVEN ACROSS SOUTHEAST WYOMING...SO INCREASED
POP BETWEEN 30 TO 60 PERCENT ALONG I25 AND I80 AS WELL.
PRECIPITATION WILL PUSH NORTH AS THE TROUGH BECOMES A CLOSED LOW
NORTHEAST OF THE FORECAST AREA OVER THE DAKOTAS. EXPECT DRIER AIR
TO PUSH INTO THE SOUTHERN HALF OF THE FORECAST AREA ALONG I80
WEDNESDAY NIGHT AND THURSDAY. INCREASED TEMPERATURES ON THURSDAY
AND BELIEVE IT WILL BE A LITTLE BIT WARMER COMPARED TO WEDNESDAY
DUE TO DOWNSLOPE WINDS AND ADIABATIC WARMING. TEMPERATURES WILL BE
IN THE 60S TO LOW 70S OVER MOST OF THE AREA WITH PERHAPS MID TO
UPPER 50S ACROSS THE HIGH VALLEYS WEST OF THE LARAMIE RANGE.
.LONG TERM...(FRIDAY THROUGH TUESDAY) ISSUED AT 220 PM MDT TUE
MAY 28 2013
WINDY AND A LITTLE COOLER CONDITIONS FOR FRIDAY AS SFC/UPPER LOW
MOVE SLOWLY EAST OVER THE DAKOTAS. MAIN DIFFICULTY WILL BE HOW MUCH
WRAP AROUND SHOWERS PROGRESS SOUTH INTO THE CWA. BEST CHANCES OVER
THE NORTH AND HAVE TAILORED POPS THIS WAY. NEXT PUSH OF COOLER AIR
WILL SINK OVER THE AREA LATE FRIDAY COOLING THINGS A LITTLE MORE
FOR SATURDAY ALONG WITH WIDELY SCATTERED SHOWERS...POSSIBLY A
LITTLE MORE WIDESPREAD. DRY AND WARMER CONDITIONS RETURN SUNDAY
AND MONDAY AS A SHORT UPPER RIDGE MOVES BY. UPPER TROF THEN
SETTLES OVER THE PACIFIC NW EARLY NEXT WEEK WITH SW FLOW ALOFT
BECOMING ESTABLISHED OVER THE CWA BY LATE MONDAY. CHANCES FOR
WIDELY SCTD SHOWERS AND TSTRMS INCREASE A BIT TUESDAY AS MOISTURE
AND INSTABILITY INCREASE.
&&
.AVIATION...(FOR THE 00Z TAF ISSUANCE)
SCATTERED TO NUMEROUS THUNDERSTORMS OVER THE WESTERN NEBRASKA
PANHANDLE WILL CONTINUE EARLY THIS EVENING. BRIEF MVFR VIS AND CIGS
ARE POSSIBLE IN THESE THUNDERSTORMS WITH FREQUENT
LIGHTNING...HAIL...AND GUSTY WINDS UP TO 50 MPH. ACTIVITY WILL
GRADUALLY DIMINISH AND PUSH EAST OF KSNY TO KCDR AFTER 04Z LATE THIS
EVENING. ISOLATED SHOWERS AND TSTORMS ARE EXPECTED ACROSS SOUTHEAST
WYOMING WHERE IT IS SIGNIFICANTLY DRIER...VFR CONDITIONS WILL
CONTINUE THROUGH TONIGHT FROM KRWL...TO KCYS.
THERE IS HIGHER CONFIDENCE THAT PATCHY FOG AND LOW CIGS WILL DEVELOP
AGAIN ACROSS WESTERN NEBRASKA...ESPECIALLY AT KSNY AND KAIA. ADDED
IFR CONDITIONS TO THE 00Z TAF AFTER MIDNIGHT.
&&
.FIRE WEATHER...
ISSUED AT 155 PM MDT TUE MAY 28 2013
CHANCES FOR MORE WIDESPREAD RAINFALL AND WETTING RAINS WILL
INCREASE DURING THE NEXT 12 TO 48 HOURS AS A PACIFIC STORM SYSTEM
MOVES ACROSS THE CENTRAL ROCKIES AND ADJACENT PLAINS. FUELS IN
GREEN UP STAGE...COOLER TEMPERATURES AND HIGHER RELATIVE
HUMIDITIES WILL RESULT IN NO FIRE WEATHER CONCERNS THROUGH THE END
OF THE WEEK. WARMER AND DRIER CONDITIONS WILL RETURN EARLY NEXT
WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...CLAYCOMB
SHORT TERM...TJT
LONG TERM...RE
AVIATION...TJT
FIRE WEATHER...TJT
AREA FORECAST DISCUSSION
NWS MIAMI FL
249 AM EDT FRI MAY 31 2013
.SHORT TERM (TODAY THROUGH SUNDAY)...
MODELS CONTINUE TO HAVE ISSUES WITH THE SURFACE PRESSURE PATTERNS
BUT ARE IN GOOD AGREEMENT WITH THE MID LEVELS. A WEAK PRESSURE
PATTERN ALOFT IS FORECAST TO CONTINUE WITH ABUNDANT DEEP LAYER
MOISTURE IN PLACE WITH PWAT VALUES HOVERING AROUND TWO INCHES. AT
THE SURFACE, THE GFS HAS TRENDED WITH THE ECMWF IN CONTINUING THE
HIGH PRESSURE OVER THE SOUTHEAST STATES BUT SHIFTING IT TO THE
EAST OVER THE WEEKEND AS A WEAK COLD FRONT MOVES INTO THE
SOUTHEAST STATES. THIS WILL RESULT IN RETAINING A STRONG SOUTHEAST
LOW LEVEL FLOW TODAY AND THEN DIMINISHING SATURDAY AND SUNDAY.
THE NAM SEEMS TO BE SUFFERING FROM SOME OF ITS MESOSCALE BIASING
AS IT DEVELOPS A INVERTED TROUGH ALONG THE WEST COAST OF THE
PENINSULA VEERING THE LOW LEVEL FLOW TO THE SOUTH ACROSS OUR
REGION. THE GFS AND ECMWF RETAIN THE THE SOUTHEAST FLOW AND THIS
SEEMS MORE REASONABLE. SO THE HIGH RISK OF RIP CURRENTS WILL
CONTINUE TODAY AND SATURDAY WITH A LESSER THREAT ON SUNDAY BUT
LIKELY MAINTAINING A MODERATE RISK.
THE MAV AND MET GUIDANCE IS NEARLY IN PERFECT AGREEMENT WITH
LIKELY POPS TODAY AND SUNDAY WITH A LESSER CHANCE ON SUNDAY.
HOWEVER, RADAR SIGNATURES ARE NOT TERRIBLY IMPRESSIVE CURRENTLY
AND THE SHORT TERM HIGH RESOLUTION MODELS ARE NOT IN AGREEMENT ON
THE EVOLUTION TOWARDS SUNRISE INTO THE EARLY MORNING. BOTH THE
HRRR AND THE WRF HAVE INITIALIZED WELL IN DEPICTING FAST MOVING
SHOWERS OVER THE ATLANTIC AND MOVING ONSHORE ALONG THE SOUTHEAST
COAST. THE WRF THEN FLARES UP CONVECTION ALONG THE NORTHERN
BROWARD AND PALM BEACH COASTS AROUND 09Z AND DEVELOPS HEAVY
SHOWERS OVER MUCH OF EASTERN PALM BEACH COUNTY. THE HRRR ON THE
OTHER HAND KEEPS THE SHOWERS MINIMAL AND THEN CLEARS OUT THE EAST
COAST DURING THE MORNING WITH ADDITIONAL ACTIVITY DEVELOPING OVER
THE WESTERN HALF IN THE LATE MORNING AS THEY MOVE TOWARDS COASTAL
COLLIER COUNTY. GIVEN THE STATE OF THE CURRENT ATMOSPHERE AND THE
HIGHER RELIABILITY OF THE HRRR, WILL UNDERCUT THE POPS BY AROUND
ONE CATEGORY FROM GUIDANCE.
.LONG TERM (SUNDAY NIGHT THROUGH THURSDAY)...
THE GFS AND ECMWF ARE BOTH IN GOOD AGREEMENT IN THE EXTENDED
PERIOD IN MAINTAINING A MOIST AND UNSTABLE ENVIRONMENT OVER SOUTH
FLORIDA WITH WEAK PRESSURE PATTERNS BOTH AT THE SURFACE AND ALOFT.
THIS WILL RESULT IN A MORE TYPICAL SEA BREEZE DRIVEN CONVECTION
PATTERN DURING THE AFTERNOONS AND EVENINGS WITH SLOW STORM MOTION.
&&
.AVIATION...
ATLANTIC SHOWERS WILL CONTINUE MOVE ONSHORE THROUGH THE MORNING
ALONG THE EAST COAST AND THEN TRANSITION TOWARDS KAPF DURING THE
AFTERNOON. THERE COULD BE A FEW THUNDERSTORMS ALONG THE WEST COAST
THIS AFTERNOON BUT COVERAGE DOES NOT WARRANT MENTION IN THE TAF AT
THIS TIME. EAST WIND CONTINUES TO BE MODERATE THIS MORNING BUT THE
GRADIENT WILL BEGIN TO RELAX THIS AFTERNOON BUT STILL EXPECTED TO
BE STRONG ENOUGH TO INHIBIT SEA BREEZE DEVELOPMENT ALONG THE
COLLIER COUNTY COAST.
&&
.MARINE...
MARINE CONDITIONS WILL CONTINUE TO BE ROUGH ESPECIALLY ALONG THE
ATLANTIC SIDE WITH SCA IN EFFECT. THE SCA WILL BE EXTENDED INTO
THIS AFTERNOON WITH THESE CONDITIONS SLOWLY BEGINNING TO SUBSIDE
OVER THE WEEKEND AS THE HIGH PRESSURE SHIFTS TO THE EAST AND THE
GRADIENT WEAKENS.
&&
.FIRE WEATHER...
AMPLE TROPICAL MOISTURE SO NO PROBLEMS OR CONCERNS.
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 83 74 85 73 / 50 30 60 30
FORT LAUDERDALE 87 77 88 75 / 50 40 60 40
MIAMI 86 75 89 76 / 50 40 60 40
NAPLES 86 75 84 75 / 60 30 60 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...RIP CURRENT RISK THROUGH THIS AFTERNOON FOR COASTAL BROWARD-
COASTAL MIAMI DADE-COASTAL PALM BEACH.
AM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR BISCAYNE
BAY-COASTAL WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL
OUT 20 NM-COASTAL WATERS FROM JUPITER INLET TO DEERFIELD
BEACH, FL OUT 20 NM-WATERS FROM DEERFIELD BEACH TO OCEAN
REEF, FL EXTENDING FROM 20 NM TO THE TERRITORIAL WATERS OF
THE BAHAMAS-WATERS FROM JUPITER INLET TO DEERFIELD BEACH,
FL EXTENDING FROM 20 NM TO 60 NM.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...30/KOB
AVIATION/RADAR...13/SI
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
232 AM CDT FRI MAY 31 2013
.DISCUSSION...
504 PM CDT
HAVE DECIDED TO EXPAND THE CURRENT FLASH FLOOD WATCH...TO INCLUDE
THE ENTIRE CWA.
WAS ON THE FENCE EARLIER WITH REGARDS TO EXPANDING THE CURRENT
FLASH FLOOD WATCH FOR THE REMAINDER OF THE CWA...BUT WITH LATEST
TRENDS THIS PAST AFTERNOON...HAVE DECIDED TO INCLUDE THE ENTIRE
CWA. THE THUNDERSTORMS THIS PAST AFTERNOON HAVE BEEN VERY GOOD
RAIN PRODUCERS...WHICH WILL LIKELY CONTINUE OVER THE NEXT COUPLE
OF HOURS AS PWATS REMAIN RATHER HIGH. ALSO...MONITORING THE
CONVECTIVE LINE TO THE WEST AND ITS MOVEMENT EAST INTO THE CWA.
LATEST TRENDS AND SHORT TERM GUIDANCE ARE HINTING AT THE
POSSIBILITY OF MORE TRAINING ACROSS THE CWA...WITH CURRENT FLOW IN
PLACE...DEFINITELY SEEMS REASONABLE.
RODRIGUEZ
//PREV DISCUSSION...
400 PM CDT
MAIN FORECAST CONCERNS REMAIN TIED TO THE ACTIVE WEATHER PATTERN
EXPECTED THROUGH THE START OF THE WEEKEND...WITH ROUNDS OF HEAVY
RAINFALL LIKELY AS WELL AS CONTINUED CHANCES FOR SEVERE WEATHER.
HAVE NOT EXPANDED THE FFA WATCH AT THIS TIME WITH MORE WIDESPREAD
HEAVY RAINFALL AND FLOODING NOT APPEARING LIKELY UNTIL LATER
FRIDAY AFTERNOON INTO FRIDAY NIGHT. THIS IS NOT TO SAY THAT
LOCALIZED FLOODING COULD NOT OCCUR WITH ANY POSSIBLE STRONG
THUNDERSTORMS TONIGHT. A MORE LIKELY SCENARIO AT THIS TIME IS WITH
THE CURRENT SCATTERED DEVELOPMENT TO BE REPLACED WITH A MORE
PROGRESSIVE AREA OF THUNDERSTORMS.
CURRENT ISOLATED TO SCATTERED ACTIVITY ACROSS THE CWA WILL
CONTINUE TO INCREASE IN COVERAGE THIS EVENING...AS LARGE SCALE
FORCING INCREASES WITH THE APPROACH A FAIRLY STOUT MID LEVEL WAVE
PROPAGATING NORTH THROUGH CENTRAL ILLINOIS. AREAS WHICH CONTINUE
TO BE FAVORED ARE LOCATIONS ALONG AND WEST OF A LINE FROM CRYSTAL
LAKE SOUTH TO GIBSON CITY IN ILLINOIS. LATEST RAP ANALYSIS SHOWS
MODERATE INSTABILITY IN PLACE WITH MLCAPE AROUND 2000 J/KG...AND
WITH MID/LOW LEVEL LAPSE RATES EXPECTED TO ONLY INCREASE OVER THE
NEXT COUPLE OF HOURS. THIS INCREASING FORCING AND INSTABILITY WILL
AID FURTHER DEVELOPMENT/EXPANSION OF CURRENT ACTIVITY ONGOING
ACROSS THE WESTERN HALF OF THE CWA. DEEP LAYER SHEAR REMAINS
MEAGER AT 25-30KT PRIMARILY OVER THE WESTERN CWA WHILE 0-1KM SHEAR
ALSO REMAINS HIGHEST ALONG OR JUST WEST OF THE CWA...ESPECIALLY
GOING INTO WESTERN ILLINOIS AND EASTERN IOWA.
HOWEVER...SHORT TERM GUIDANCE CONTINUES TO SHOW AN INCREASE IN
BOTH DEEP LAYER SHEAR AND LOW LEVEL SHEAR ACROSS THE CURRENT WATCH
AREA THROUGH THE REMAINDER OF THE AFTERNOON. THIS WILL HELP FOR
MORE ORGANIZED AND LONGER LIVED DEVELOPMENT ACROSS THE WESTERN
CWA...LEAVING THE THREAT OF HAIL/DAMAGING WINDS AS WELL AS
POSSIBLE TORNADOES. ALTHOUGH MORE ORGANIZED DEVELOPMENT IS MORE
LIKELY FOR THE WESTERN HALF OF THE CWA...SHORT TERM GUIDANCE IS
HINTING AT A SLIGHT INCREASE IN DEEP LAYER SHEAR MORE TOWARDS FAR
NORTHEAST ILLINOIS. THIS SLIGHT INCREASE COINCIDING WITH THE
CURRENT CAPE IN PLACE...COULD FAVOR SOME ISOLATED STRONGER
DEVELOPMENT IN THAT LOCATION IN THE NEXT COUPLE OF HOURS. WILL
NEED CONTINUE TO MONITOR DEVELOPMENT IN THAT LOCATION...WHICH
WOULD INCLUDE THE CITY OF CHICAGO/METRO AREA LATE THIS AFTERNOON
INTO THE EARLY EVENING...AS I COULD EASILY FORESEE AN UPSCALE IN
GROWTH IN BOTH INTENSITY AND COVERAGE.
EVEN IF THAT DOES NOT MATERIALIZE THROUGH LATE THIS
AFTERNOON...CONTINUE TO MONITOR A LARGER LINE OF THUNDERSTORMS
SITUATED FROM SOUTHERN IOWA SOUTH INTO MISSOURI. THIS LINE IS TIED
MORE CLOSELY TO FAIRLY STRONG MID LEVEL WAVE LIFTING NORTHEAST OUT
KANSAS AND ATTENDANT SURFACE TROUGH/BOUNDARY FROM IOWA INTO
MISSOURI. ALL GUIDANCE IS SHOWING THIS LINE OF THUNDERSTORMS
WILL INCREASE IN INTENSITY OVER THE NEXT COUPLE OF HOURS...WHICH
WOULD MAKE SENSE AS THIS LINE OF THUNDERSTORMS MOVES FURTHER
EAST/NORTHEAST INTO A MORE UNSTABLE ENVIRONMENT. STRONG FORCING
OWING TO LARGE SCALE SUPPORT AND LOW/MID LEVEL CONVERGENCE SHOULD
AID IN THIS LINE OF THUNDERSTORMS FURTHER BLOSSOMING AS IT MOVES
TOWARDS THE WESTERN ILLINOIS...ESPECIALLY AS DEEP LAYER SHEAR IS
ALSO INCREASING.
THERE IS STILL SOME UNCERTAINTY AS TO THE WHOLE EVOLUTION OF THIS
LINE OF THUNDERSTORMS AS IT WORKS ITS WAY TOWARDS NORTHERN
ILLINOIS THIS EVENING...MAINLY IN THE STRENGTH OF THIS COMPLEX AND
POTENTIAL SEVERE THREAT. ALTHOUGH THERE WILL BE SOME SLIGHT
DIMINISHING TREND WITH THE CURRENT INSTABILITY IN PLACE...FEEL
THAT IT WILL MORE THAN SUFFICE TO HELP KEEP THIS LINE SHIFTING
EAST. ALSO...SHORT TERM GUIDANCE IS INDICATING THAT 0-3KM BULK
SHEAR WILL INCREASE TOWARDS THE 00Z TIME FRAME THIS
EVENING...WHICH WOULD ACT TO HELP FOR ORGANIZATION AND INCREASE IN
THREAT FOR LINEAR STRUCTURES/STRONG DAMAGING WINDS. SO HAVE
TRENDED MORE PESSIMISTIC...WITH THINKING THAT THIS LINE AND STRONG
DAMAGING WINDS COULD MOVE ACROSS NORTHERN ILLINOIS THIS EVENING.
HAVE ALSO TRENDED MORE TOWARDS THE HRRR...WITH SYSTEM TIMING
THINKING THAT IT SHOULD BE KNOCKING ON THE WESTERN CWA DOORSTEPS
BY 00-01Z AND THEN CONTINUE EAST TOWARDS NORTHEAST ILLINOIS
THROUGH THE SEVERAL HOURS THERE AFTER. BEYOND THAT TIME
FRAME...CONFIDENCE LOWERS WITH REGARDS TO THE STRENGTH OF THIS
SYSTEM. NONETHELESS...HEAVY RAINFALL AND FLASH FLOODING COULD
BECOME ISSUES OVERNIGHT TONIGHT ESPECIALLY AS PWATS ARE AT OR JUST
ABOVE 1.7 INCHES AND 850MB DEW POINTS REMAIN RATHER HIGH.
THUNDERSTORM COMPLEX IS THEN EXPECTED TO SHIFT EAST OF THE CWA BY
EARLY FRIDAY MORNING...WITH A DRYING TREND EXPECTED DURING THAT
TIME FRAME. THIS SHOULD NOT LAST TOO LONG WITH DRY CONDITIONS ONLY
EXPECTED THROUGH MID DAY AS ATTENTION QUICKLY SHIFTS BACK WEST
WITH THE APPROACH OF ANOTHER STRONG MID LEVEL WAVE EJECTING OUT OF
THE CENTRAL PLAINS. YET AGAIN...A SEVERE THREAT WILL BE IN PLACE
ON FRIDAY WITH GROWING CONCERNS OF MORE POTENTIAL FLOODING FROM
THIS POINT ON...INTO FRIDAY NIGHT AND SATURDAY. THE SEVERE THREAT
WILL LIKELY AFFECT THE ENTIRE CWA ON FRIDAY AND WITH CLEARING
ANTICIPATED FRIDAY MORNING...INSTABILITY IS EXPECTED TO RAPIDLY
INCREASE BY LATE MORNING WITH MODERATE TO STRONG INSTABILITY
LIKELY IN PLACE ACROSS THE CWA. STRONG DEEP LAYER SHEAR IN UPWARDS
OF 50-60KT WILL EASILY SUPPORT WIDESPREAD ORGANIZED DEVELOPMENT AS
SOON AS EARLY AFTERNOON ON FRIDAY. STRONG DAMAGING WINDS AND HAIL
ARE THE MAIN THREAT...BUT WITH SREF GUIDANCE INDICATING ELEMENTS
CORRESPONDING TO SUPERCELLULAR STRUCTURES OR ROTATING
THUNDERSTORMS COULD COME TOGETHER ACROSS THE CWA. WILL NEED TO
CONTINUE TO MONITOR THIS TIME FRAME AS WELL...AS WIDESPREAD SEVERE
IS APPEARING LIKELY ONCE AGAIN. GOING INTO FRIDAY NIGHT...HEAVY
RAINFALL APPEARS LIKELY WITH SEVERAL STRONG WAVES PROPAGATING
NORTHEAST ACROSS THE CWA PROVIDING CONTINUED DEVELOPMENT AS WELL
AS A STRONG LLJ ORIENTED TOWARDS NORTHEAST ILLINOIS...PUMPING HIGH
THETAE AIR INTO THE REGION.
RODRIGUEZ
EXTENDED PERIOD...SUNDAY THROUGH THURSDAY...
BY DAYBREAK SUNDAY THE UPPER RIDGE IS TO HAVE PROGRESSED EASTWARD
TO OVER THE UPPER MIDWEST AND MID MS VALLEY WITH A SURFACE
TROUGH/SECONDARY COLD FRONT JUST TO THE NORTHWEST AND NORTH OF THE
LOCAL FORECAST AREA. THIS TROUGH/FRONT IS PROGGED TO MOVE ACROSS ALL
OF THE FA DURING THE SUNDAY MORNING AS THE UPPER TROUGH CONTINUES ON
TO OVER THE UPPER GREAT LAKES AND LOWER OH VALLEY BY EVENING. UNTIL
THE TROUGH AXIS MOVES A BIT FURTHER EAST OF THE IMMEDIATE AREA THERE
WILL BE A LINGERING CHANCE OF SHOWERS DURING SUNDAY MORNING.
THE SECONDARY COLD FRONT WILL REINFORCE THE COLD AIR ADVECTION THAT
WILL HAVE STARTED TO OCCUR LATE SATURDAY AND SATURDAY NIGHT WITH THE
INITIAL COLD FRONT. BETWEEN THE PAIR OF FRONT 850HPA TEMPERATURES
ARE PROGGED TO FALL AROUND 10 DEGREES C FROM 18Z SATURDAY TO 00Z
MONDAY......DOWN TO AROUND +4 OR +5C. WITH COOL HIGH PRESSURE
BUILDING OVER THE AREA TEMPERATURES WILL BE COOL SUNDAY AND MONDAY
WITH HIGHS ONLY IN THE 60S...WITH LAKESIDE MAX TEMPERATURES LIKELY
TO ONLY BE IN THE 55-60F RANGE AS A LONG FETCH DOWN LAKE MICHIGAN
BRINGS AIR ADDITIONALLY COOLED BY THE STILL CHILLY LAKE ASHORE
SUNDAY. WHILE THE SURFACE RIDGE AXIS WILL BE MOVING OVER WI AND
WESTERN IL DURING MONDAY ALLOWING WINDS TO SLACKEN...A WEAK NE
SYNOPTIC FLOW WILL STILL BE IN PLACE AIDED BY A LAKE BREEZE.
THE FURTHER EASTWARD PROGRESS OF THE UPPER TROUGH IS TO BE SLOW AS A
CLOSED LOW TO FORM OVER SOUTHERN HUDSON BAY/NORTHERN ONTARIO IS
PROGGED TO BE DROP SOUTH...THEN SOUTHEAST AND EAST OVER ONTARIO
SATURDAY NIGHT THROUGH MONDAY NIGHT. AS THE UPPER TROUGH/LOW MOVES
FURTHER EAST A WEAK UPPER RIDGE WILL MOVE OVER THE REGION TUESDAY AS
ANOTHER UPPER LOW MOVES EAST OVER THE FAR SOUTHERN CANADIAN
PRAIRIE/FAR NORTHERN PLAINS. THIS WILL ALLOW A BIT OF MODERATION IN
TEMPERATURES TUESDAY AND WEDNESDAY AS EAST-SOUTHEAST WINDS BECOMES
SOUTHEASTERLY AND INCREASING THOUGH THIS LOW LEVEL FLOW WILL KEEP
THE IL SHORE...ESPECIALLY THE FAR NORTHERN PART....STILL CHILLY.
INLAND AREAS SHOULD PEAK IN THE UPPER 60S AND LOWER 70S TUESDAY...
AND A COUPLE DEGREES WARMER WEDNESDAY. WITH CONTINUED WARM AIR
ADVECTION AHEAD OF THE APPROACHING UPPER LOW/TROUGH THE WARMING
TREND WILL CONTINUE THURSDAY WITH MOST LOCATIONS REACHING THE MID
AND UPPER 70S THOUGH THERE WILL STILL BE AN EASTERLY COMPONENT TO
THE LOW LEVEL FLOW TO KEEP THE IL SHORELINE IN THE 60S.
TRS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* SHRA CONTINUING THROUGH 08Z-10Z WITH ONLY A SMALL CHANCE OF
THUNDER IN THAT TIME.
* SOME SHIFTING IN THE WINDS FROM SE TO SW THROUGH 12Z OR SO BUT
GUSTINESS SHOULD ONLY BE SPORADIC.
* MVFR FOG POSSIBLE AROUND DAYBREAK.
* SOUTHERLY WINDS GUSTING TO AROUND 25 KT DURING THE DAY TODAY.
* STORM CHANCES...INCLUDING STRONG POTENTIAL...RETURNING FRI
AFTERNOON AND EVE.
//DISCUSSION...UPDATED 06Z...
PERIODS OF MAINLY SHOWERS...WITH SOME STORMS /ESPECIALLY SOUTH AND
EAST TRACON AREAS/...WITH CONTINUE THROUGH 09Z-10Z. THERE IS
EXPECTED TO BE A LULL IN PRECIP COVERAGE DURING THE MORNING RUSH
BUT THERE STILL MAY BE A FEW SCATTERED SHOWERS. THE RAINS HAVE
FURTHER MADE THE LOW-LEVELS MOIST WHICH COULD HELP PATCHY FOG
DEVELOPMENT NEAR DAWN. SOUTHERLY WINDS WILL INCREASE AFTER
DAYBREAK AS MIXING ENSUES AND SOME STRONG GUSTS TO AROUND 25 KT
ARE EXPECTED AGAIN.
AS FOR THUNDER CHANCES THIS AFTERNOON AND EVE...IT IS CHALLENGING
AND QUITE A BIT IS LIKELY TO DEPEND ON HOW THUNDER ACTIVITY IN
EASTERN KS/MO PLAYS OUT EARLY THIS MORNING. IF THIS WORKS INTO IL
BY LATE MORNING/EARLY AFTERNOON IT MAY STIFLE SOME OF THE
EXPLOSIVE CONVECTIVE DEVELOPMENT THAT COULD OCCUR WITH AS MUCH
INSTABILITY AS WILL BE PRESENT. IT ALSO COULD KEEP MUCH OF THE
STORM ACTIVITY SOUTH OF THE CHICAGOLAND TERMINALS. THAT SAID...THE
CERTAINTY ON HOW THIS EARLY MORNING CONVECTION TO OUR WEST PLAYS
OUT IS LOW. WHILE THE SETUP FOR LATER TODAY INTO THIS EVE COULD
PRESENT SEVERAL HOURS
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN SHOWERS WITH MEDIUM CONFIDENCE IN NO THUNDER
OR IFR CONDITIONS IN RAIN.
* HIGH CONFIDENCE IN SOUTHERLY WINDS DURING THE DAY WITH MEDIUM
CONFIDENCE IN MAGNITUDE OF THE GUSTS.
* LOW CONFIDENCE ON TIMING AND DURATION OF AFTERNOON/EVE
THUNDERSTORMS.
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 06Z...
* SATURDAY...TSRA LIKELY DURING THE DAY WITH A CHANCE OF SHRA
DURING THE NIGHT. MVFR CIGS/VIS POSSIBLE.
* SUNDAY...CHANCE OF SHRA EARLY...OTRW...VFR.
* MONDAY THROUGH EARLY TUESDAY...VFR. WX NIL.
* LATE TUESDAY THROUGH WEDNESDAY...CHANCE TSRA/SHRA.
MTF
&&
.MARINE...
230 AM CDT
ANOMALOUSLY DEEP LOW PRESSURE ACROSS THE DAKOTAS WILL CONTINUE
SOUTHERLY FLOW ACROSS THE LAKE. THE STABLE MARINE LAYER WILL KEEP
WINDS FROM BECOMING TOO GUSTY...ALTHOUGH NEARSHORE AREAS OF IL AND
IN WILL LIKELY BE CLOSE TO SMALL CRAFT CRITERION WINDS GIVEN THE
OFFSHORE COMPONENT. PERIODS OF STORMS ARE LIKELY ACROSS THE LAKE
THROUGH TONIGHT AND POSSIBLY INTO SATURDAY. THE SYSTEM WILL SWING
A COLD FRONT ACROSS THE LAKE LATE SATURDAY NIGHT ALLOWING FOR A
WIND SHIFT TO NORTHWEST. THESE WINDS WILL TURN NORTHERLY ON SUNDAY
AND GRADUALLY DIMINISH INTO MONDAY AS HIGH PRESSURE BUILDS OVER
THE LAKE. THIS HIGH WILL SLOWLY SHIFT EAST THROUGH MIDWEEK...BUT
CONTINUE TO STRENGTHEN SO THE RETURN FLOW INFLUENCE LOOKS TO BE
SLOW TO SPREAD ACROSS THE LAKE. THIS SHOULD OFFER A FAIRLY QUIET
MARINE PERIOD FROM SUN-THU.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 7 PM SATURDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 7
PM SATURDAY.
LM...NONE.
&&
$$
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WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
100 AM CDT FRI MAY 31 2013
.DISCUSSION...
504 PM CDT
HAVE DECIDED TO EXPAND THE CURRENT FLASH FLOOD WATCH...TO INCLUDE
THE ENTIRE CWA.
WAS ON THE FENCE EARLIER WITH REGARDS TO EXPANDING THE CURRENT
FLASH FLOOD WATCH FOR THE REMAINDER OF THE CWA...BUT WITH LATEST
TRENDS THIS PAST AFTERNOON...HAVE DECIDED TO INCLUDE THE ENTIRE
CWA. THE THUNDERSTORMS THIS PAST AFTERNOON HAVE BEEN VERY GOOD
RAIN PRODUCERS...WHICH WILL LIKELY CONTINUE OVER THE NEXT COUPLE
OF HOURS AS PWATS REMAIN RATHER HIGH. ALSO...MONITORING THE
CONVECTIVE LINE TO THE WEST AND ITS MOVEMENT EAST INTO THE CWA.
LATEST TRENDS AND SHORT TERM GUIDANCE ARE HINTING AT THE
POSSIBILITY OF MORE TRAINING ACROSS THE CWA...WITH CURRENT FLOW IN
PLACE...DEFINITELY SEEMS REASONABLE.
RODRIGUEZ
//PREV DISCUSSION...
400 PM CDT
MAIN FORECAST CONCERNS REMAIN TIED TO THE ACTIVE WEATHER PATTERN
EXPECTED THROUGH THE START OF THE WEEKEND...WITH ROUNDS OF HEAVY
RAINFALL LIKELY AS WELL AS CONTINUED CHANCES FOR SEVERE WEATHER.
HAVE NOT EXPANDED THE FFA WATCH AT THIS TIME WITH MORE WIDESPREAD
HEAVY RAINFALL AND FLOODING NOT APPEARING LIKELY UNTIL LATER
FRIDAY AFTERNOON INTO FRIDAY NIGHT. THIS IS NOT TO SAY THAT
LOCALIZED FLOODING COULD NOT OCCUR WITH ANY POSSIBLE STRONG
THUNDERSTORMS TONIGHT. A MORE LIKELY SCENARIO AT THIS TIME IS WITH
THE CURRENT SCATTERED DEVELOPMENT TO BE REPLACED WITH A MORE
PROGRESSIVE AREA OF THUNDERSTORMS.
CURRENT ISOLATED TO SCATTERED ACTIVITY ACROSS THE CWA WILL
CONTINUE TO INCREASE IN COVERAGE THIS EVENING...AS LARGE SCALE
FORCING INCREASES WITH THE APPROACH A FAIRLY STOUT MID LEVEL WAVE
PROPAGATING NORTH THROUGH CENTRAL ILLINOIS. AREAS WHICH CONTINUE
TO BE FAVORED ARE LOCATIONS ALONG AND WEST OF A LINE FROM CRYSTAL
LAKE SOUTH TO GIBSON CITY IN ILLINOIS. LATEST RAP ANALYSIS SHOWS
MODERATE INSTABILITY IN PLACE WITH MLCAPE AROUND 2000 J/KG...AND
WITH MID/LOW LEVEL LAPSE RATES EXPECTED TO ONLY INCREASE OVER THE
NEXT COUPLE OF HOURS. THIS INCREASING FORCING AND INSTABILITY WILL
AID FURTHER DEVELOPMENT/EXPANSION OF CURRENT ACTIVITY ONGOING
ACROSS THE WESTERN HALF OF THE CWA. DEEP LAYER SHEAR REMAINS
MEAGER AT 25-30KT PRIMARILY OVER THE WESTERN CWA WHILE 0-1KM SHEAR
ALSO REMAINS HIGHEST ALONG OR JUST WEST OF THE CWA...ESPECIALLY
GOING INTO WESTERN ILLINOIS AND EASTERN IOWA.
HOWEVER...SHORT TERM GUIDANCE CONTINUES TO SHOW AN INCREASE IN
BOTH DEEP LAYER SHEAR AND LOW LEVEL SHEAR ACROSS THE CURRENT WATCH
AREA THROUGH THE REMAINDER OF THE AFTERNOON. THIS WILL HELP FOR
MORE ORGANIZED AND LONGER LIVED DEVELOPMENT ACROSS THE WESTERN
CWA...LEAVING THE THREAT OF HAIL/DAMAGING WINDS AS WELL AS
POSSIBLE TORNADOES. ALTHOUGH MORE ORGANIZED DEVELOPMENT IS MORE
LIKELY FOR THE WESTERN HALF OF THE CWA...SHORT TERM GUIDANCE IS
HINTING AT A SLIGHT INCREASE IN DEEP LAYER SHEAR MORE TOWARDS FAR
NORTHEAST ILLINOIS. THIS SLIGHT INCREASE COINCIDING WITH THE
CURRENT CAPE IN PLACE...COULD FAVOR SOME ISOLATED STRONGER
DEVELOPMENT IN THAT LOCATION IN THE NEXT COUPLE OF HOURS. WILL
NEED CONTINUE TO MONITOR DEVELOPMENT IN THAT LOCATION...WHICH
WOULD INCLUDE THE CITY OF CHICAGO/METRO AREA LATE THIS AFTERNOON
INTO THE EARLY EVENING...AS I COULD EASILY FORESEE AN UPSCALE IN
GROWTH IN BOTH INTENSITY AND COVERAGE.
EVEN IF THAT DOES NOT MATERIALIZE THROUGH LATE THIS
AFTERNOON...CONTINUE TO MONITOR A LARGER LINE OF THUNDERSTORMS
SITUATED FROM SOUTHERN IOWA SOUTH INTO MISSOURI. THIS LINE IS TIED
MORE CLOSELY TO FAIRLY STRONG MID LEVEL WAVE LIFTING NORTHEAST OUT
KANSAS AND ATTENDANT SURFACE TROUGH/BOUNDARY FROM IOWA INTO
MISSOURI. ALL GUIDANCE IS SHOWING THIS LINE OF THUNDERSTORMS
WILL INCREASE IN INTENSITY OVER THE NEXT COUPLE OF HOURS...WHICH
WOULD MAKE SENSE AS THIS LINE OF THUNDERSTORMS MOVES FURTHER
EAST/NORTHEAST INTO A MORE UNSTABLE ENVIRONMENT. STRONG FORCING
OWING TO LARGE SCALE SUPPORT AND LOW/MID LEVEL CONVERGENCE SHOULD
AID IN THIS LINE OF THUNDERSTORMS FURTHER BLOSSOMING AS IT MOVES
TOWARDS THE WESTERN ILLINOIS...ESPECIALLY AS DEEP LAYER SHEAR IS
ALSO INCREASING.
THERE IS STILL SOME UNCERTAINTY AS TO THE WHOLE EVOLUTION OF THIS
LINE OF THUNDERSTORMS AS IT WORKS ITS WAY TOWARDS NORTHERN
ILLINOIS THIS EVENING...MAINLY IN THE STRENGTH OF THIS COMPLEX AND
POTENTIAL SEVERE THREAT. ALTHOUGH THERE WILL BE SOME SLIGHT
DIMINISHING TREND WITH THE CURRENT INSTABILITY IN PLACE...FEEL
THAT IT WILL MORE THAN SUFFICE TO HELP KEEP THIS LINE SHIFTING
EAST. ALSO...SHORT TERM GUIDANCE IS INDICATING THAT 0-3KM BULK
SHEAR WILL INCREASE TOWARDS THE 00Z TIME FRAME THIS
EVENING...WHICH WOULD ACT TO HELP FOR ORGANIZATION AND INCREASE IN
THREAT FOR LINEAR STRUCTURES/STRONG DAMAGING WINDS. SO HAVE
TRENDED MORE PESSIMISTIC...WITH THINKING THAT THIS LINE AND STRONG
DAMAGING WINDS COULD MOVE ACROSS NORTHERN ILLINOIS THIS EVENING.
HAVE ALSO TRENDED MORE TOWARDS THE HRRR...WITH SYSTEM TIMING
THINKING THAT IT SHOULD BE KNOCKING ON THE WESTERN CWA DOORSTEPS
BY 00-01Z AND THEN CONTINUE EAST TOWARDS NORTHEAST ILLINOIS
THROUGH THE SEVERAL HOURS THERE AFTER. BEYOND THAT TIME
FRAME...CONFIDENCE LOWERS WITH REGARDS TO THE STRENGTH OF THIS
SYSTEM. NONETHELESS...HEAVY RAINFALL AND FLASH FLOODING COULD
BECOME ISSUES OVERNIGHT TONIGHT ESPECIALLY AS PWATS ARE AT OR JUST
ABOVE 1.7 INCHES AND 850MB DEW POINTS REMAIN RATHER HIGH.
THUNDERSTORM COMPLEX IS THEN EXPECTED TO SHIFT EAST OF THE CWA BY
EARLY FRIDAY MORNING...WITH A DRYING TREND EXPECTED DURING THAT
TIME FRAME. THIS SHOULD NOT LAST TOO LONG WITH DRY CONDITIONS ONLY
EXPECTED THROUGH MID DAY AS ATTENTION QUICKLY SHIFTS BACK WEST
WITH THE APPROACH OF ANOTHER STRONG MID LEVEL WAVE EJECTING OUT OF
THE CENTRAL PLAINS. YET AGAIN...A SEVERE THREAT WILL BE IN PLACE
ON FRIDAY WITH GROWING CONCERNS OF MORE POTENTIAL FLOODING FROM
THIS POINT ON...INTO FRIDAY NIGHT AND SATURDAY. THE SEVERE THREAT
WILL LIKELY AFFECT THE ENTIRE CWA ON FRIDAY AND WITH CLEARING
ANTICIPATED FRIDAY MORNING...INSTABILITY IS EXPECTED TO RAPIDLY
INCREASE BY LATE MORNING WITH MODERATE TO STRONG INSTABILITY
LIKELY IN PLACE ACROSS THE CWA. STRONG DEEP LAYER SHEAR IN UPWARDS
OF 50-60KT WILL EASILY SUPPORT WIDESPREAD ORGANIZED DEVELOPMENT AS
SOON AS EARLY AFTERNOON ON FRIDAY. STRONG DAMAGING WINDS AND HAIL
ARE THE MAIN THREAT...BUT WITH SREF GUIDANCE INDICATING ELEMENTS
CORRESPONDING TO SUPERCELLULAR STRUCTURES OR ROTATING
THUNDERSTORMS COULD COME TOGETHER ACROSS THE CWA. WILL NEED TO
CONTINUE TO MONITOR THIS TIME FRAME AS WELL...AS WIDESPREAD SEVERE
IS APPEARING LIKELY ONCE AGAIN. GOING INTO FRIDAY NIGHT...HEAVY
RAINFALL APPEARS LIKELY WITH SEVERAL STRONG WAVES PROPAGATING
NORTHEAST ACROSS THE CWA PROVIDING CONTINUED DEVELOPMENT AS WELL
AS A STRONG LLJ ORIENTED TOWARDS NORTHEAST ILLINOIS...PUMPING HIGH
THETAE AIR INTO THE REGION.
RODRIGUEZ
EXTENDED PERIOD...SUNDAY THROUGH THURSDAY...
BY DAYBREAK SUNDAY THE UPPER RIDGE IS TO HAVE PROGRESSED EASTWARD
TO OVER THE UPPER MIDWEST AND MID MS VALLEY WITH A SURFACE
TROUGH/SECONDARY COLD FRONT JUST TO THE NORTHWEST AND NORTH OF THE
LOCAL FORECAST AREA. THIS TROUGH/FRONT IS PROGGED TO MOVE ACROSS ALL
OF THE FA DURING THE SUNDAY MORNING AS THE UPPER TROUGH CONTINUES ON
TO OVER THE UPPER GREAT LAKES AND LOWER OH VALLEY BY EVENING. UNTIL
THE TROUGH AXIS MOVES A BIT FURTHER EAST OF THE IMMEDIATE AREA THERE
WILL BE A LINGERING CHANCE OF SHOWERS DURING SUNDAY MORNING.
THE SECONDARY COLD FRONT WILL REINFORCE THE COLD AIR ADVECTION THAT
WILL HAVE STARTED TO OCCUR LATE SATURDAY AND SATURDAY NIGHT WITH THE
INITIAL COLD FRONT. BETWEEN THE PAIR OF FRONT 850HPA TEMPERATURES
ARE PROGGED TO FALL AROUND 10 DEGREES C FROM 18Z SATURDAY TO 00Z
MONDAY......DOWN TO AROUND +4 OR +5C. WITH COOL HIGH PRESSURE
BUILDING OVER THE AREA TEMPERATURES WILL BE COOL SUNDAY AND MONDAY
WITH HIGHS ONLY IN THE 60S...WITH LAKESIDE MAX TEMPERATURES LIKELY
TO ONLY BE IN THE 55-60F RANGE AS A LONG FETCH DOWN LAKE MICHIGAN
BRINGS AIR ADDITIONALLY COOLED BY THE STILL CHILLY LAKE ASHORE
SUNDAY. WHILE THE SURFACE RIDGE AXIS WILL BE MOVING OVER WI AND
WESTERN IL DURING MONDAY ALLOWING WINDS TO SLACKEN...A WEAK NE
SYNOPTIC FLOW WILL STILL BE IN PLACE AIDED BY A LAKE BREEZE.
THE FURTHER EASTWARD PROGRESS OF THE UPPER TROUGH IS TO BE SLOW AS A
CLOSED LOW TO FORM OVER SOUTHERN HUDSON BAY/NORTHERN ONTARIO IS
PROGGED TO BE DROP SOUTH...THEN SOUTHEAST AND EAST OVER ONTARIO
SATURDAY NIGHT THROUGH MONDAY NIGHT. AS THE UPPER TROUGH/LOW MOVES
FURTHER EAST A WEAK UPPER RIDGE WILL MOVE OVER THE REGION TUESDAY AS
ANOTHER UPPER LOW MOVES EAST OVER THE FAR SOUTHERN CANADIAN
PRAIRIE/FAR NORTHERN PLAINS. THIS WILL ALLOW A BIT OF MODERATION IN
TEMPERATURES TUESDAY AND WEDNESDAY AS EAST-SOUTHEAST WINDS BECOMES
SOUTHEASTERLY AND INCREASING THOUGH THIS LOW LEVEL FLOW WILL KEEP
THE IL SHORE...ESPECIALLY THE FAR NORTHERN PART....STILL CHILLY.
INLAND AREAS SHOULD PEAK IN THE UPPER 60S AND LOWER 70S TUESDAY...
AND A COUPLE DEGREES WARMER WEDNESDAY. WITH CONTINUED WARM AIR
ADVECTION AHEAD OF THE APPROACHING UPPER LOW/TROUGH THE WARMING
TREND WILL CONTINUE THURSDAY WITH MOST LOCATIONS REACHING THE MID
AND UPPER 70S THOUGH THERE WILL STILL BE AN EASTERLY COMPONENT TO
THE LOW LEVEL FLOW TO KEEP THE IL SHORELINE IN THE 60S.
TRS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* SHRA CONTINUING THROUGH 08Z-10Z WITH ONLY A SMALL CHANCE OF
THUNDER IN THAT TIME.
* SOME SHIFTING IN THE WINDS FROM SE TO SW THROUGH 12Z OR SO BUT
GUSTINESS SHOULD ONLY BE SPORADIC.
* MVFR FOG POSSIBLE AROUND DAYBREAK.
* SOUTHERLY WINDS GUSTING TO AROUND 25 KT DURING THE DAY TODAY.
* STORM CHANCES...INCLUDING STRONG POTENTIAL...RETURNING FRI
AFTERNOON AND EVE.
//DISCUSSION...UPDATED 06Z...
PERIODS OF MAINLY SHOWERS...WITH SOME STORMS /ESPECIALLY SOUTH AND
EAST TRACON AREAS/...WITH CONTINUE THROUGH 09Z-10Z. THERE IS
EXPECTED TO BE A LULL IN PRECIP COVERAGE DURING THE MORNING RUSH
BUT THERE STILL MAY BE A FEW SCATTERED SHOWERS. THE RAINS HAVE
FURTHER MADE THE LOW-LEVELS MOIST WHICH COULD HELP PATCHY FOG
DEVELOPMENT NEAR DAWN. SOUTHERLY WINDS WILL INCREASE AFTER
DAYBREAK AS MIXING ENSUES AND SOME STRONG GUSTS TO AROUND 25 KT
ARE EXPECTED AGAIN.
AS FOR THUNDER CHANCES THIS AFTERNOON AND EVE...IT IS CHALLENGING
AND QUITE A BIT IS LIKELY TO DEPEND ON HOW THUNDER ACTIVITY IN
EASTERN KS/MO PLAYS OUT EARLY THIS MORNING. IF THIS WORKS INTO IL
BY LATE MORNING/EARLY AFTERNOON IT MAY STIFLE SOME OF THE
EXPLOSIVE CONVECTIVE DEVELOPMENT THAT COULD OCCUR WITH AS MUCH
INSTABILITY AS WILL BE PRESENT. IT ALSO COULD KEEP MUCH OF THE
STORM ACTIVITY SOUTH OF THE CHICAGOLAND TERMINALS. THAT SAID...THE
CERTAINTY ON HOW THIS EARLY MORNING CONVECTION TO OUR WEST PLAYS
OUT IS LOW. WHILE THE SETUP FOR LATER TODAY INTO THIS EVE COULD
PRESENT SEVERAL HOURS
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN SHOWERS WITH MEDIUM CONFIDENCE IN NO THUNDER
OR IFR CONDITIONS IN RAIN.
* HIGH CONFIDENCE IN SOUTHERLY WINDS DURING THE DAY WITH MEDIUM
CONFIDENCE IN MAGNITUDE OF THE GUSTS.
* LOW CONFIDENCE ON TIMING AND DURATION OF AFTERNOON/EVE
THUNDERSTORMS.
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 06Z...
* SATURDAY...TSRA LIKELY DURING THE DAY WITH A CHANCE OF SHRA
DURING THE NIGHT. MVFR CIGS/VIS POSSIBLE.
* SUNDAY...CHANCE OF SHRA EARLY...OTRW...VFR.
* MONDAY THROUGH EARLY TUESDAY...VFR. WX NIL.
* LATE TUESDAY THROUGH WEDNESDAY...CHANCE TSRA/SHRA.
MTF
&&
.MARINE...
1259 PM CDT
THE SHORT TERM OF THE MARINE FORECAST HAS A SMALL CRAFT ADVISORY FOR
STRONG WINDS ACROSS THE ILLINOIS AND NORTHWEST INDIANA NEARSHORE
WATERS.
ACROSS THE OPEN WATERS OF THE LAKE...MAINLY THE NORTHERN THIRD OF
THE LAKE...AREAS OF DENSE FOG CONTINUE.
VERY WARM/MOIST AIR CONTINUES TO SLIDE NORTH ACROSS THE LAKE...AND
WITH THE MUCH COOLER LAKE SURFACE WATER...HAS RESULTED IN AREAS OF
DENSE FOG PERSISTING. IT DOES APPEAR BASED ON LATEST VISIBLE IMAGERY
THAT THE FOG HAS REMAINED FOCUSED ACROSS THE NORTHERN THIRD OF THE
LAKE. OBS HAVE CONTINUED TO SHOW INCREASING GUSTS...WITH SPEEDS
GENERALLY AROUND 20-25KT ACROSS THE SOUTHERN HALF OF THE LAKE.
FURTHER NORTH IT APPEARS THE WINDS ARE SLIGHTLY LESS...WITH SPEEDS
GENERALLY IN THE 15-25KT.
THE TROUGH OF LOW PRESSURE REMAINS CENTERED ACROSS THE CENTRAL
PLAINS...WITH A WEAK LOW PRESSURE LIFTING NORTH INTO THE NORTHERN
PLAINS. AN ASSOCIATED WARM FRONT EXTENDS EAST THROUGH THE UPPER
GREAT LAKES REGION. WITH THE POSITION OF THE LOW PRESSURE AND THE
PERSISTING RIDGE OF HIGH PRESSURE ACROSS THE SOUTHEASTERN UNITED
STATES...THE WIND FLOW WILL REMAIN SOUTHERLY ACROSS THE LAKE. AT
TIMES THROUGH EARLY THIS EVENING GUSTS MAY APPROACH 30 KT...MAINLY
FOR THE SOUTHERN PORTIONS OF THE LAKE INCLUDING THE NEARSHORE
WATERS. AS A RESULT WILL MAINTAIN THE CURRENT SMALL CRAFT ADVISORY
THAT IS IN EFFECT.
THE TROUGH OF LOW PRESSURE POSITIONED OVER THE CENTRAL PLAINS WILL
SLOWLY PUSH EAST...WITH A LOW PRESSURE APPROACHING THE WESTERN GREAT
LAKES SAT MIDDAY. THE RECENT FORECAST TRENDS HAVE BEEN TO SLOW THE
ARRIVAL OF THIS SYSTEM...THUS IT IS POSSIBLE THAT THE MAIN LOW
PRESSURE MAY NOT ARRIVE UNTIL CLOSER TO SAT NIGHT. THEN AN
ASSOCIATED COLD FRONT WILL WILL PUSH EAST ACROSS THE LAKE OVERNIGHT
SAT INTO SUN. WINDS AT THAT POINT WILL TURN WESTERLY THEN NORTHERLY
WITH MUCH COOLER AIR FLOWING OVER THE LAKE.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 7 PM SATURDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 7
PM SATURDAY.
LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565
UNTIL 7 AM FRIDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
222 AM EDT FRI MAY 31 2013
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 300 PM EDT THU MAY 30 2013
THE MAIN FOCUS THIS PERIOD IS ON CONVECTIVE POTENTIAL/EVOLUTION.
SYNOPTICALLY...A CLOSED LOW WILL MEANDER SLOWLY EAST ACROSS THE
NORTHERN PLAINS WITH DEEP/MOIST CYCLONICALLY CURVED SOUTHWEST FLOW
IN PLACE FROM THE SOUTHERN PLAINS NORTHEAST INTO THE GREAT LAKES
REGION. AT THE SURFACE THE PRIMARY SFC FRONT FRONT WILL BE DRAPED
FROM THE UPPER MIDWEST SOUTHWEST INTO THE SOUTHERN PLAINS WITH A
MOIST/HUMID/UNSTABLE AIRMASS OUT AHEAD OF THIS.
THE REMAINDER OF THE AFTERNOON INTO EARLY THIS EVENING...
19Z REGIONAL RADAR MOSAIC SHOWING SCATTERED CONVECTION FIRING ACROSS
MUCH OF ILLINOIS IN A ZONE OF WEAK MOISTURE CONVERGENCE ON THE
EASTERN FLANK OF A CONVECTIVELY ENHANCED/INDUCED SHORTWAVE LIFTING
INTO WEST-CENTRAL ILLINOIS...WITH ISOLATED CONVECTION STARTING TO
POP ACROSS THE LOCAL AREA. LATEST RAP ANALYSIS SHOWS 1500-2000
J/KG OF MLCAPE ACROSS THE AREA WITH LITTLE/NO CIN. EXPECT ISOLATED
TO SCATTERED CONVECTION TO MAINLY IMPACT AREAS ALONG AND WEST OF
INTERSTATE 69 INTO THE EARLY EVENING AS WEAK FORCING AND CONTINUED
LOW/MID LEVEL THETA-E ADVECTION ADVECTS OVER THIS AREA. MARGINAL
20-25 KNOTS OF DEEP LAYER EFFECTIVE SHEAR A DEFINITE LIMITING
FACTOR FOR ORGANIZATION AND ISOLATED SEVERE STORMS...ALTHOUGH
CANNOT RULE OUT AN ISOLATED DAMAGING WIND/HAIL THREAT IF ANY
MULTICELL CLUSTERS/SMALL LINE SEGMENTS TAKE SHAPE.
LARGE SCALE UPPER SUPPORT WILL INCREASE TONIGHT INTO FRIDAY MORNING
AS A MORE PRONOUNCED MID LEVEL SHORTWAVE TROUGH NOW EJECTING INTO
THE CENTRAL PLAINS ON THE NOSE OF AN UPPER JET TRANSLATES NORTHEAST
INTO THE WESTERN/NORTHERN GREAT LAKES. THIS SUPPORTS THE IDEA OF
LATEST HI-RES GUIDANCE IN MAINTAINING A WEAKENING MESOSCALE
CONVECTIVE SYSTEM (ACROSS CENTRAL IOWA INTO WESTERN MISSOURI AS OF
THIS WRITING) EAST INTO AT LEAST OUR WESTERN ZONES AFTER 05/06Z ISH.
MEAGER MID LEVEL LAPSE RATES COUPLED WITH DIURNAL COOLING SHOULD
ALLOW WHAT MIGHT BE A LINE OF SEVERE CONVECTION INTO ILLINOIS THIS
EVENING TO WEAKEN (FALL APART?) AS IT ATTEMPTS TO MAKE INTO THE
LOCAL AREA FROM WEST TO EAST OVERNIGHT...WITH SHOWERS/ISO THUNDER
POSSIBLY LINGERING INTO FRIDAY MORNING ALONG THE MCS/MCV RESIDUAL
OUTFLOW BOUNDARY. BUMPED UP POPS A BIT AFTER MIDNIGHT....HIGHEST
WEST.
SUBSIDENCE/AVA BEHIND THE MID LEVEL TROUGH AXIS LATER FRIDAY MORNING
INTO THE EARLY/MID AFTERNOON HOURS WITH ATMOSPHERE POSSIBLY WORKED
OVER FROM MORNING CLOUDS/SHOWERS SHOULD RESULT IN A LULL IN PCPN
ACROSS THE AREA DURING THIS TIME. ALTHOUGH RETAINED LOW 20-30
PERCENT POPS BTW 15-21Z AS RENEWED CONVECTION COULD FORM ALONG THE
RESIDUAL OUTFLOW BOUNDARY BY EARLY/MID AFTERNOON...BEST CHANCES
ACROSS OUR SOUTHEASTERN ZONES. CHANCES FOR ADDITIONAL
CONVECTION...POTENTIALLY SEVERE...BY LATE AFTERNOON AND EVENING
ARE DISCUSSED IN THE LONG TERM SECTION.
&&
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 300 PM EDT THU MAY 30 2013
POTENT SW AND ATTENDANT CLOSED LOW OVR SD IS XCPD TO OPEN FRI NIGHT
AND KICK EWD ACRS THE LAKES IN RESPONSE OF ARRIVAL OF UPSTREAM
KICKER INTO THE PACNW. AT THE SFC...PRONOUNCED SFC WAVE OVR SRN MN
SAT MORNING WILL EJECT EWD TO LK HURON BY SUN MORNING AS ASSOCD
TRAILING CDFNT SURGES EWD.
BEST LL MSTR FLUX/LL THETA-E RIDGING XCPD FRI EVENING W/AGAIN A
CONDITIONAL SVR THREAT PENDING SHRT TERM CONV EVOLUTION/MAINTENANCE
INTO THE WRN LAKES FRI AFTN. OTRWS STG SFC CDFNT TO CROSS CWA SAT
AFTN/EVE W/STG FORCING FOR ASCENT WITHIN CONTD SIG LL MSTR PLUME AND
LIKELY MOST FVRBL WINDOW FOR SIG RAINFALL.
STG CAA FOLLOWS ON SUN W/RAPID NEWD ADVTN OF MID LVL DRYSLOT
UNDERNEATH MID LVL TROUGH PIVOTING THROUGH MI. GIVEN GENERAL 12Z
CONSENSUS SOLUTION WILL DROP LOW CHC POPS MOST AREAS SANS FAR SE.
DRY AND SEASONABLE WX XPCD THROUGH UNTIL THE END OF THE PD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 220 AM EDT FRI MAY 31 2013
MARGINAL INSTABILITY DOWNSTREAM OF ONGOING TSRA AT KSBN...WITH ONLY
TRAILING STRATIFORM SHRA EXPECTED BEYOND 07 UTC. RAMPED 50KT SWRLY
FLOW AT 8H SHOULD AID IN MAINTENANCE/SLOW DECAY OF SLIGHTLY MORE
ORGANIZED CONVECTION ACROSS WEST CENTRAL INDIANA...ASSOCIATED WITH
HIGHER POCKETS OF EFFECTIVE DEEP LAYER SHEAR ON ORDER OF
35KTS...SUCH THAT INCLUSION OF LOW/MEDIUM CONFIDENCE FOR TSRA INTO
KFWA IN 08-10 UTC TIMEFRAME...THOUGH BESIDES CONVECTIVELY INDUCED
HAZARDS ANTICIPATE ONLY A BRIEF HIGH END MVFR VSBY REDUCTION IN CELL
CENTROIDS. GREAT UNCERTAINTY AS A MULTITUDE OF LESS THAN STELLAR
MODEL INDICATIONS/CONVECTIVE TRENDS LATER TODAY BELIES MOST PROBABLE
OUTCOME. IMMEDIATE UPSTREAM DESTABILIZATION ACROSS MID MISSISSIPPI
VALLEY ALONG WITH MARKEDLY INCREASED DEEP LAYER SHEAR TO SUPPORT
STORM DEVELOPMENT BY LATE AFTERNOON/EVENING ACROSS IA/MO/IL AND INTO
NRN IN BY LATE EVENING THROUGH END OF FORECAST PERIOD WITH PSBL
LINEAR ORGANIZATION SUPPORTING STRONG WIND GUST RISK. TIMING TO
LIKELY CHANGE/EVOLVE IN SUBSEQUENT ISSUANCES AS NUANCES FROM EFFECTS
OF ONGOING CONVECTION BETTER DETERMINED.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...STEINWEDEL
LONG TERM...T
AVIATION...MURPHY
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AREA FORECAST DISCUSSION
NWS DES MOINES IA
323 AM CDT FRI MAY 31 2013
.SHORT TERM.../TODAY /...
ISSUED AT 323 AM CDT FRI MAY 31 2013
THUNDERSTORMS HAVE DEVELOPED IN NORTHERN MISSOURI ALONG A ZONE OF
WARM AIR ADVECTION AND A LOW LEVEL JET. JUST NORTH OF THAT AREA BUT
STILL IN MO SOME WEAKER STORMS HAVE DEVELOPED AND ARE DISSIPATING.
THE STORMS HAVE AN EAST/NORTHEASTERLY TRACK AND WILL EVENTUALLY CLIP
FAR SOUTHERN IOWA. THE WEAKENING STORMS JUST ACROSS OUR BORDER WILL
LIKELY ONLY PRODUCE SOME SHOWERS ACROSS THE FAR SOUTH IN THE NEXT
FEW HOURS. A VORT MAX AND SHORT WAVE WILL PIVOT AROUND THE UPPER
LOW OVER THE EASTERN DAKOTAS AND THIS WILL SHIFT THE STORMS THAT ARE
A LITTLE FURTHER SOUTH IN NORTHERN MO RIGHT INTO SOUTHERN/SOUTHEAST
IOWA BY MID TO LATE MORNING THEN INTO EASTERN IOWA BY EARLY
AFTERNOON.
BY MID TO LATE AFTERNOON A STRONGER SHORT WAVE WILL PUSH INTO
WESTERN IOWA WHICH WILL BRING MORE THUNDERSTORMS TO THAT AREA AND
THIS WILL SHIFT EAST FROM 21Z INTO THE EVENING HOURS. THERE WILL BE
A TIME IN THE AFTERNOON WHERE SHOWERS AND STORMS WILL STILL BE OVER
EASTERN IOWA AND ADDITIONAL STORMS DEVELOPING OVER THE WEST WITH
CENTRAL IOWA DRY. LAPSE RATES OVER SOUTHERN IOWA AND ABOUT THE
SOUTHEAST THIRD OF THE STATE ARE PRETTY STEEP THIS AFTERNOON AND
THERE IS MORE THAN SUFFICIENT SHEAR FOR A FEW SEVERE STORMS. IN
ADDITION...HEAVY RAINFALL IS LIKELY WITH THE STORMS AS WELL...MAINLY
OVER THE FAR EAST AND SOUTHEAST.
YESTERDAY THE HI RES NMM EAST REALLY HAD THE PRECIP AREAS PEGGED AND
ALSO HAD DECENT TIMING OF THE PRECIP. I STILL LIKE WHAT THIS MODEL
DOES WITH THE PRECIP TODAY HOWEVER IT IS NOT PICKING UP THE MO
CONVECTION VERY WELL AT THIS TIME. IT IS ABOUT 3 HOURS LATER WITH
THAT SO I BLENDED NMM POPS WITH THE HRRR AND NAM12.
AS FOR TEMPS...THERE SHOULD BE SLIGHTLY WARMER AIR OVER THE SOUTH
AND SOUTHEAST TODAY SO I NUDGED HIGHS UP IN THESE AREAS. THE NORTH
SHOULD SEE TEMPS A FEW DEGREES WARMER AS WELL.
.LONG TERM.../TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 323 AM CDT FRI MAY 31 2013
FEWER CONCERNS FOR THE NEXT SEVERAL DAYS AS UPPER TROUGH BEGINS TO
SWING EAST. ALREADY THE MAIN H850 MOISTURE CHANNEL HAS SHIFTED EAST
OF THE AREA WITH THE LINE OF STRONGER THUNDERSTORMS THAT EXITED THE
EASTERN PORTION OF THE FORECAST AREA EARLY THIS EVENING. HOWEVER
THERE WILL STILL BE SOME RESIDUAL CONVECTION FAR SOUTHEAST EARLY IN
THE PERIOD TONIGHT...ENDING QUICKLY AND MOVING EAST BY 06Z.
MEANWHILE...THE MAIN FEATURE YET LATE TONIGHT AND EARLY SATURDAY
WILL BE THE OLD H500 LOW WHICH IS LIKELY TO SPIN UP SOME SHOWERS AND
ISOLATED THUNDER AS IT MOVES ACROSS THE REGION TOMORROW AS THE COLD
POOL UNDERNEATH THE UPPER LEVEL LOW DROPS SOUTHEAST INTO THE REGION.
STEEP LAPSE RATES WILL BE IN THE AREA OF THE LOW ON SATURDAY AND
OVER THE NORTH INTO MN AND WESTERN WI NON SUPERCELL TORNADO PARAMETER
IS INCREASING. SOMETHING TO KEEP AN EYE ON THERE...AN ISOLATED
FUNNEL CLOUD OR LANDSPOUT MAY BE POSSIBLE IF LAPSE RATES BECOME
STEEP ENOUGH IN THE AFTERNOON HOURS. OTHERWISE...THE OLD LOW WILL
PULL EAST SATURDAY NIGHT AND SUNDAY LEAVING THE REGION WITH COOLER
AIR FOR THE FIRST PART OF JUNE. THIS WILL KEEP THE AREA IN THE 60S
FOR HIGHS ON SUNDAY WITH MID 40S NORTH AND LOWER 50S SOUTH FOR LOWS
ON MONDAY MORNING. AS THE HIGH MOVES EAST...HIGHS WILL RESPOND INTO
THE LOWER 70S FOR MONDAY. MONDAY NIGHT WARM AIR ADVECTION AND MID
LEVEL MOISTURE BEGIN TO INCREASE AGAIN...RESULTING IN LATE
NIGHT/EARLY MORNING ELEVATED CONVECTION. TUESDAY LOOKS ACTIVE AS A
STRONGER WAVE ROTATES NORTHEAST INTO THE STATE. THIS WILL RESULT IN
MORE WIDESPREAD THUNDERSTORMS WITH RAINFALL AMOUNTS POSSIBLY
APPROACHING ONE INCH IN SOME PLACES. THIS WILL CERTAINLY KEEP SOIL
MOISTURE HIGH...AND ALSO RESULT IN RENEWED RIVER RISES. THE SYSTEM
WILL GRADUALLY EXIT THE REGION BY THURSDAY. THE LARGER SCALE FLOW
PATTERN REMAINS GENERALLY WESTERLY AT MID TO HIGH LEVELS. THIS
PROMOTES LEE SIDE TROUGHING AND WITH A CONTINUED SUB TROPICAL HIGH
ANCHORED OFF THE EAST COAST A WETTER THAN NORMAL PATTERN IS LIKELY
TO CONTINUE OVER THE NEXT 7 TO 10 DAYS. ANOTHER INTERESTING WRINKLE
IS A TROPICAL DISTURBANCE IN THE GULF OF MEXICO BY NEXT THUR/FRIDAY
WHICH MAY EVENTUALLY BE PULLED NORTH TOWARD THE MID MISSISSIPPI
RIVER VALLEY. HIGH TEMPERATURES OVER THE NEXT WEEK WILL LIKELY
REMAIN IN THE 70S ON AVERAGE AND NOT BREAK OUT OF A 65 TO 75 RANGE
BY TOO MUCH IF ANY. ANOTHER NOTE WITH OUR CURRENT WET WEATHER WILL
BE CLOUD COVER. UNLESS WE HAVE A STRONG HIGH AND STRONG
SUBSIDENCE...MOST LATE MORNINGS AND AFTERNOONS ON ANY SUNNY DAY WILL
GO SCT TO BKN BY AFTERNOON.
&&
.AVIATION...31/06Z
ISSUED AT 1155 PM CDT THU MAY 30 2013
VFR CONDITIONS EXPECTED THROUGHOUT THE TAF PERIOD FOR ALL TAF
SITES. HOWEVER...CONVECTION LOOKS TO DEVELOP FRIDAY MORNING AND
WILL POSSIBLY AFFECT OTM PAST 15Z FRIDAY. LOW CONFIDENCE WITH
TIMING AND WITH MENTION OF MVFR OR LESS CIGS/VIS. HAVE MENTION OF
THUNDER FRIDAY. OTHERWISE...DECENT MIXING BEHIND TROUGH THAT IS
EXPECTED TO MOVE THROUGH FRIDAY MORNING. VERY SMALL CHANCE DSM
WILL SEE SOME RAIN/THUNDER THROUGH 07Z FRIDAY AND SO ONLY HAVE
VCTS MENTIONED ATTM.
&&
.HYDROLOGY...
ISSUED AT 323 AM CDT FRI MAY 31 2013
A FLASH FLOOD WATCH REMAINS IN EFFECT FOR BUTLER COUNTY AT THIS
TIME DUE TO THE SMALL BREACH IN THE LEVEE ALONG THE BEAVER CREEK
AT NEW HARTFORD.
A WEATHER DISTURBANCE CAUSING AN AREA OF THUNDERSTORMS FROM KANSAS
AND MISSOURI WILL ROTATE NORTHEAST TODAY...AFFECTING THE SOUTHEAST
HALF OF THE FORECAST AREA LATER THIS MORNING THROUGH THE AFTERNOON
HOURS. THE SOUTHEAST MAY SEE UP TO AN INCH OR MORE OF RAIN...BUT
CURRENT FLASH FLOOD GUIDANCE HAS INCREASED TO 1.3 TO 1.5 INCHES
PER HOUR AND 1.5 TO 2.25 INCHES IN 3 HOURS AT PRESENT. UNLESS THE
STORMS BACK BUILD...THE RISK FOR ANY FLASH FLOODING REMAINS LOW
TODAY ACROSS OUR FORECAST AREA.
RIVER FLOOD WARNINGS REMAIN IN EFFECT FOR NUMEROUS LOCATIONS THROUGHOUT
THE HYDROLOGICAL SERVICES AREA FOR THE NEXT 5 TO 6 DAYS. IN THE
SHORT TERM... THE OLD H500 LOW WILL CYCLE EAST IN THE NEXT 24 TO
48 HOURS AND THEN DEPART. WITH ONLY LIGHT SHOWERS OR ISOLATED
THUNDER EXPECTED... RAINFALL WILL REMAIN LIGHT. FOLLOWING
THAT...HIGH PRESSURE WILL KEEP THE REGION RAIN FREE TO MONDAY EVENING.
THIS WILL SLOWLY ALLEVIATE THE SOME OF THE WATER ISSUES THOUGH
LARGER MAIN STEM RIVER SYSTEMS WILL REMAIN ABOVE FLOOD STAGE THROUGH
THE FORECAST PERIOD. ADDTIONAL MODERATE RAINFALL IS LIKELY BEGINNING
LATE MONDAY NIGHT THROUGH THURSDAY WHICH WILL NEED TO BE WATCHED.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS EVENING FOR BUTLER.
&&
$$
SHORT TERM...BOKSA
LONG TERM...REV
AVIATION...PODRAZIK
HYDROLOGY...REV
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1159 PM CDT THU MAY 30 2013
...UPDATED AVIATION DISCUSSION...
.SHORT TERM.../TONIGHT /...
ISSUED AT 350 PM CDT THU MAY 30 2013
MAIN SHORTWAVE LIFTING THROUGH THE BASE OF THE UPPER LEVEL TROUGH
RESPONSIBLE FOR AREA OF SHOWERS AND THUNDERSTORMS ACROSS THE FAR
SOUTHEASTERN CWA. AS SHORTWAVE CONTINUES TO LIFT NORTHEAST THROUGH
THE EASTERN PORTION OF THE STATE...AREA OF SHOWERS/THUNDERSTORMS
WILL CONTINUE TO SHOVE EAST OUT OF THE CWA. LOOKING BACK TO THE
WEST...HAVE SOME ISOLATED WEAK CELLS DEVELOPING ACROSS CENTRAL
NE/KS. THIS ACTIVITY MAY APPROACH THE SOUTHWESTERN/SOUTHERN CWA BY
MID EVENING...BUT IS EXPECTED TO BE RELATIVELY WEAK WITH LESS THAN
1000 J/KG CAPE ON NAM/RAP SOUNDINGS. HRRR SEEMS TO BE GRASPING
CURRENT RADAR TRENDS CORRECTLY...SO KEPT POPS CLOSE TO THE HRRR
OUTPUT. THE WESTERN ACTIVITY IS MOSTLY DIURNALLY DRIVEN...SO EXPECT
IT TO DIMINISH TOWARD SUNSET. ANOTHER WAVE OF ENERGY TO ROUND THE
BASE OF THE UPPER LEVEL TROUGH TO APPROACH THE STATE LATE
TONIGHT...MAY ALLOW FOR SOME SHOWERS AND ISOLATED THUNDERSTORMS TO
DEVELOP TOWARD SUNRISE FRIDAY MORNING. THE DEEP MOISTURE THAT HAS
BEEN IN PLACE ACROSS THE STATE OVER THE PAST WEEK...IS BEGINNING TO
PUSH EAST WITH THE ADVANCEMENT OF A DRY LINE OVER CENTRAL
NE/KS...THEREFORE THE HEAVY RAIN THREAT WILL BE LESSENED WITH ANY
ACTIVITY THAT DEVELOPS LATE TONIGHT/EARLY FRIDAY MORNING.
.LONG TERM.../FRIDAY THROUGH THURSDAY/...
ISSUED AT 350 PM CDT THU MAY 30 2013
AN UPPER LEVEL LOW PRESSURE SYSTEM WILL REMAIN NEARLY STATIONARY
OVER THE DAKOTAS AND MINNESOTA FRIDAY AND FRIDAY NIGHT...BEFORE
MOVING EASTWARD ACROSS IOWA ON SATURDAY AND AWAY OVER THE GREAT
LAKES ON SATURDAY NIGHT. ON FRIDAY MORNING LOW LEVEL FLOW WILL
STILL BE FROM THE SOUTH SOUTHWEST AND AN APPROACHING SHORTWAVE
MOVING AROUND THE UPPER LOW SHOULD KICK OFF THUNDERSTORMS ACROSS
EASTERN KANSAS LATE TONIGHT THAT WILL MOVE ACROSS OUR SOUTHERN AND
EASTERN COUNTIES ON FRIDAY. HAVE INCREASED POPS INTO THE 70 TO 80
PERCENT RANGE IN OUR SOUTHEAST TO ACCOUNT FOR THIS...AND SEVERE
WEATHER WILL BE POSSIBLE IN THESE AREAS AS WELL. FRIDAY SHOULD BE
FAIRLY WARM ESPECIALLY IF SKIES ARE ABLE TO CLEAR ACROSS MUCH OF
THE CWA...AND HAVE RAISED FORECAST HIGHS A BIT EVEN INTO THE
LOWER 80S IN SOME AREAS.
BY FRIDAY EVENING THE DAYTIME STORMS WILL BE EXITING TO THE EAST
AHEAD OF A SURFACE TROUGH MOVING ACROSS THE AREA. WINDS BEHIND
THIS TROUGH WILL TURN TO WEST AND THEN NORTHWEST WITH COOLER AIR
FLOWING INTO THE AREA. IN ADDITION...AS THE UPPER LEVEL LOW
PRESSURE TROUGH MOVES ACROSS OUR AREA ON SATURDAY IT WILL BE
ACCOMPANIED BY THICK CLOUDS AND LIGHT SHOWERS MAKING FOR A GREY
AND DAMP DAY. NO THUNDERSTORMS ARE ANTICIPATED AND ANY RAINFALL
AMOUNTS WILL BE LIGHT. COVERAGE IS UNCERTAIN SO HAVE MAINTAINED
POPS BELOW 50 PERCENT...BUT THIS MAY NEED TO BE INCREASED LATER IN
A CLASSIC HIGH POP/LOW QPF SCENARIO. BY SUNDAY A SURFACE RIDGE
WILL BUILD IN MAKING FOR MOSTLY CLEAR AND DRY BUT COOL WEATHER
WITH LIGHT NORTH WINDS.
FROM SUNDAY NIGHT THROUGH THURSDAY THE 500 MB PATTERN WILL UNDERGO
AN EERILY SIMILAR EVOLUTION TO WHAT WE HAVE SEEN OVER THE LAST
SEVERAL DAYS...AS ANOTHER UPPER LOW MOVES INTO THE NORTHWESTERN
U.S. AND THEN ACROSS THE UPPER MIDWEST. THIS WILL RESULT IN
ANOTHER EXTENDED PERIOD OF THUNDERSTORM CHANCES FOR OUR AREA FROM
MONDAY NIGHT THROUGH THE END OF THE FORECAST PERIOD.
HOWEVER...UNLIKE THE SYSTEM OF THE PAST SEVERAL DAYS...THE 500 MB
LOW NEXT WEEK WILL NOT HAVE AS MUCH LATITUDINAL EXTENT AND WILL BE
GENERALLY MORE PROGRESSIVE...MITIGATING SOMEWHAT THE POTENTIAL FOR
EXTENDED HEAVY RAINFALL. THE DETAILS OF THE RAINFALL FORECAST FOR
NEXT WEEK WILL BE IRONED OUT LATER...BUT AT LEAST THERE WILL BE
SEVERAL RELATIVELY DRY DAYS THIS WEEKEND TO ALLOW CURRENT FLOOD
WATERS TO SUBSIDE...AND RAINFALL AMOUNTS NEXT WEEK SHOULD BE
CONSIDERABLY LIGHTER IN MOST AREAS WITH THE PRIMARY CHANCES
LIMITED TO THE MONDAY NIGHT...TUESDAY...AND TUESDAY NIGHT PERIODS.
&&
.AVIATION...31/06Z
ISSUED AT 1155 PM CDT THU MAY 30 2013
VFR CONDITIONS EXPECTED THROUGHOUT THE TAF PERIOD FOR ALL TAF
SITES. HOWEVER...CONVECTION LOOKS TO DEVELOP FRIDAY MORNING AND
WILL POSSIBLY AFFECT OTM PAST 15Z FRIDAY. LOW CONFIDENCE WITH
TIMING AND WITH MENTION OF MVFR OR LESS CIGS/VIS. HAVE MENTION OF
THUNDER FRIDAY. OTHERWISE...DECENT MIXING BEHIND TROUGH THAT IS
EXPECTED TO MOVE THROUGH FRIDAY MORNING. VERY SMALL CHANCE DSM
WILL SEE SOME RAIN/THUNDER THROUGH 07Z FRIDAY AND SO ONLY HAVE
VCTS MENTIONED ATTM.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR BUTLER.
&&
$$
SHORT TERM...BEERENDS
LONG TERM...LEE
AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1207 AM CDT FRI MAY 31 2013
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 343 PM CDT THU MAY 30 2013
WATER VAPOR LOOP SHOWING CONVECTIVE SYSTEM OVER WESTERN MO MOVING
SLOWLY EWD AHEAD OF ONE MID-LEVEL TROUGH. HOWEVER...THERE IS A VERY
SHORT WAVELENGTH BETWEEN THAT TROUGH AND THE FOLLOWING IMPULSE THAT
APPEARS TO BE OVER WRN KS AT MID AFTERNOON. SCATTERED SHOWERS AND
THUNDERSTORMS HAVE FIRED OVER WRN KS AHEAD OF THIS FEATURE AND THEY
ARE MOVING EWD. SHORT RANGE MODEL GUIDANCE NOT RESOLVING THE
DETAILS OF THIS VERY WELL...HOWEVER THE 17Z HRRR DOES NOW HAVE A
LINE OF CONVECTION MOVING INTO CENTRAL KS BY 21Z. IT FORECASTS THIS
TO BREAK UP WITH THE REMNANTS MOVING ACROSS NORTHEAST KS DURING THE
EVENING...AND THEN ANOTHER SMALL CONVECTIVE SYSTEM MOVES SOUTHEAST
OUT OF NEBRASKA INTO NORTHEAST KS LATER TONIGHT. DO NOT HAVE HIGH
CONFIDENCE IN THIS SCENARIO...ALTHOUGH SOME TYPE OF SMALL MCS WOULD
APPEAR TO BE LIKELY IN CENTRAL/NORTHEAST KS LATER TONIGHT. THIS
POSSIBLE SYSTEM WOULD APPEAR TO MOVE THROUGH FAST ENOUGH AS TO NOT
CAUSE SIG PROBLEMS WITH HEAVY RAIN/FLOODING. EARLIER CONCERNS ABOUT
WARM AIR ADVECTION CAUSING LIFT AND THUNDERSTORM AREA WITH
POTENTIALLY HEAVY RAINFALL OVER EC KS TONIGHT ARE LESSENING AS
CONVECTIVE BOUNDARY SAGS WAY SOUTH INTO NORTHEAST OKLAHOMA.
THUS...HAVE CANCELLED FLASH FLOOD WATCH THAT WAS IN EFFECT FOR THIS
AFTERNOON...AND AM NOT PLANNING ON GOING OUT WITH A NEW ONE AT THIS
TIME. CONFIDENCE IN THE DETAILS OF PRECIPITATION EVOLUTION TONIGHT
IS NOT HIGH.
ON FRIDAY...FRONTAL BOUNDARY SHOULD MAKE IT FAR ENOUGH SOUTH BY
AFTERNOON THAT THE MAIN CHANCE OF THUNDERSTORM ACTIVITY WOULD BE IN
EC KS...MAINLY SOUTHEAST OF THE KANSAS TURNPIKE. LOWS TONIGHT
EXPECTED TO BE AROUND 60 OVER NC KS AND IN THE MID 60S EC. HIGHS ON
FRIDAY ARE FORECAST TO MAX OUT AROUND 80.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 343 PM CDT THU MAY 30 2013
DETAILS ONLY GET MURKIER FOR FRIDAY EVENING...BUT AT LEAST SOME
CHANCE SHOULD EXIST AHEAD OF THE SYNOPTIC BOUNDARY FOR SOUTHERN AND
EASTERN LOCATIONS. SUFFICIENT SHEAR AND INSTABILITY WOULD SUPPORT A
SEVERE CONCERN THROUGH THIS TIME AS WELL..BUT THE SOUTHEASTWARD
SHIFTING UPPER LOW SHOULD PUSH THE EFFECTIVE FRONT SOUTH OF THE AREA
BY DAWN. COLD AIR ADVECTION SETS IN FOR SATURDAY ON NORTHWEST
BREEZES WITH SOME STRATUS/STRATOCU DEVELOPING BY MID AFTERNOON.
WEAKENING WINDS AND CLEARING SKIES SPELL A COOL NIGHT SATURDAY
NIGHT. SURFACE RIDGE SETS UP FOR SUNDAY WITH LITTLE IF ANY
MODERATION TO HIGHS.
GULF MOISTURE DOES NOT GET COMPLETELY SCOURED OUT...AND BY LATE
MONDAY SOUTH WINDS AHEAD OF AN APPROACHING NORTHERN ROCKIES CYCLONE
WILL BRING THUNDERSTORM CHANCES BACK. BEST CHANCES LOOK TO BE
TUESDAY INTO TUESDAY NIGHT WITH GOOD MODEL AGREEMENT ON A MID LEVEL
WAVE PASSING. TEMPS SHOULD GENERALLY BE NEAR EARLY JUNE NORMALS SAVE
ANY DAYTIME MCS ACTIVITY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1132 PM CDT THU MAY 30 2013
THUNDERSTORMS CONTINUE TO DEVELOP ALONG THE I 70 CORRIDOR AND SHOULD
PERSIST THROUGH 09Z IN THE TERMINALS BEFORE DECREASING/ENDING FROM WEST
TO EAST IN THE 08-11Z TIMEFRAME. EXPECT TEMPS MVFR CIGS AND VSBYS
IN THE STRONGER ELEVATED CONVECTIVE CELLS BEFORE DIMINISHING AND
ENDING BEFORE SUNRISE. BEYOND 11Z VFR CONDITIONS WILL BE THE
RULE...ALTHOUGH A FEW SHOWERS MAY LINGER INITIALLY. SFC WINDS WILL
GRADUALLY VEER THROUGH THE DAY...BUT REMAIN FAIRLY LIGHT SOUTHWEST
TO WEST.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...60
LONG TERM...65
AVIATION...63
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
350 AM EDT FRI MAY 31 2013
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 350 AM EDT FRI MAY 31 2013
07Z SFC ANALYSIS SHOWS A LARGE AREA OF LOW PRESSURE...LOCATED OVER
THE NORTHERN PLAINS...STARTING TO AFFECT WESTERN KENTUCKY WHILE THE
WESTERN EXTENT OF HIGH PRESSURE OVER THE CAROLINAS IS HOLDING ON
OVER THE EAST. THIS HAS KEPT THE SKIES MOSTLY CLEAR THROUGH THE
NIGHT...THUS FAR...AND...WHEN COMBINED WITH LIGHT WINDS...ANOTHER
DECENT NIGHT OF RADIATIONAL COOLING IN UNDERWAY. AS IS NORMAL FOR
THESE SITUATIONS...THE SHELTERED VALLEYS HAVE DECOUPLED AND ARE
RUNNING A GOOD 10 DEGREES OR SO BELOW THE MILDER RIDGES WITH SPECIFIC
TEMPERATURES VARYING FROM AROUND 60 IN THE DEEPER SPOTS TO AROUND 70
ON THE HILLS...IN THE THERMAL BELT. DEWPOINTS ARE ABOUT THE SAME AS
LAST NIGHT WITH READINGS GENERALLY IN THE LOWER 60S. AGAIN...EXPECT
SOME PATCHY FOG IN THE DEEPER VALLEYS...BUT PRIMARILY JUST NEAR THE
RIVERS AND OTHER BODIES OF WATER.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE SOUTHEAST RIDGING...
THAT HAS PROTECTED THE AREA FROM MOST OF THE CONVECTION THESE PAST
COUPLE OF DAYS...YIELDING TO THE DEVELOPING DEEP AND BROAD MID LEVEL
LOW OVER THE NORTHERN PLAINS. A COUPLE OF LEADING SHORTWAVES WILL
MOVE INTO THE OHIO VALLEY TODAY...BRUSHING BY TO THE NORTH OF OUR
CWA. FOLLOWING THIS...THE UPPER LOW WILL SLIP INTO THE UPPER MIDWEST
AND AS A RESULT DRIVE THE HEIGHTS DOWN THROUGHOUT KENTUCKY DURING
THE DAY SATURDAY. WITH THE MODELS SUCH AGREEMENT...HAVE BASICALLY
FOLLOWED A GENERAL BLEND AND KEYED IN ON THE HIGHER RESOLUTION NAM12
AND HRRR FOR DETAILS.
SENSIBLE WEATHER WILL FEATURE A CHANCE OF SHOWERS AND
THUNDERSTORMS...CURRENTLY AFFECTING WESTERN KENTUCKY...MOVING INTO
THE WESTERN PORTIONS OF EAST KENTUCKY LATER THIS MORNING AND THEN
DRIFTING EAST DURING THE REST OF THE DAY. THE EXTRA CLOUDS AND PCPN
AROUND SHOULD BE ENOUGH TO KEEP HIGH TEMPERATURES A BIT COOLER THAN
YESTERDAY. THE DAYTIME CONVECTION...FUELED BY SOME UPPER LEVEL
HELP...LOW LIS...MODERATE CAPE...AND ABOVE NORMAL PWS...WILL DIE OFF
BY EARLY EVENING LEAVING A MUGGY AIR MASS BEHIND FOR THE NIGHT WITH
ONLY A SMALL RIDGE TO VALLEY DIFFERENCE EXPECTED...BUT MORE IN THE
WAY OF PATCHY FOG. SATURDAY WILL SEE THE APPROACH OF THE SYSTEM/S
MAIN COLD FRONT AND THIS SHOULD BE ENOUGH TO KICK OFF ADDITIONAL AIR
MASS SHOWERS AND STORMS GIVEN A SIMILAR THERMAL AND MOISTURE PROFILE
AS FRIDAY.
AGAIN USED THE CONSSHORT FOR TD AND WINDS THROUGH THE FIRST 24 HOURS
AS A STARTING POINT...WITH HIGHS A BIT LOWER THAN THURSDAY FOR BOTH
TODAY AND SATURDAY...WHILE USING THE CONSALL FOR A STARTING POINT
TONIGHT. AS FOR POPS...GENERALLY ENDED UP CLOSER TO THE HIGHER MET
NUMBERS THROUGHOUT THE SHORT TERM PORTION OF THE FORECAST.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 300 AM EDT FRI MAY 31 2013
A MID/UPPER LEVEL TROUGH WILL SWING ACROSS KENTUCKY SATURDAY NIGHT
INTO SUNDAY NIGHT...PRODUCING A PERIOD OF SHOWERS AND THUNDERSTORMS
FOR THE AREA. MODELS ARE ALL IN PRETTY DECENT AGREEMENT SO HAVE
INCREASED POPS FROM LATE SATURDAY NIGHT INTO SUNDAY. SEVERE THREAT
IS FAIRLY MINIMAL AS CLOUD COVER MAY LIMIT INSTABILITY AND SHEAR IS
QUITE WEAK. FRONT WILL DEPART TO THE SOUTH SUNDAY NIGHT...WITH RAIN
CHANCES DROPPING SOUTHEASTWARD. A COOLER AND LESS HUMID AIRMASS WILL
SETTLE INTO THE AREA FOR THE EARLY PORTION OF NEXT WEEK...ALLOWING
FOR VERY PLEASANT CONDITIONS FOR EARLY JUNE. ANOTHER RIDGE OF HIGH
PRESSURE WILL BUILD OVER THE SOUTHEAST BY THE MIDDLE TO LATE
PORTIONS OF NEXT WEEK WITH RETURN FLOW AGAIN ESTABLISHING ITSELF
OVER THE AREA. AS MOISTURE INCREASES BY MIDWEEK...RAIN CHANCES WILL
SLOWLY RAMP UP SIMILAR TO THIS PAST WEEK. TEMPERATURES WILL TURN
MILDER AS WELL AS THE WEEK GOES ON. MODELS ARE ALL IN DECENT
AGREEMENT THROUGH THE END OF NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 215 AM EDT FRI MAY 31 2013
HIGH PRESSURE ALONG THE EAST COAST WILL SLIDE SLOWLY EAST WHILE A
CENTER OF LOW PRESSURE CREEPS EAST THROUGH THE NORTHERN PLAINS
OVERNIGHT. A TROUGH OF LOW PRESSURE EXTENDING FROM THE NORTHERN
PLAINS LOW WILL SWING THROUGH THE MID MS VALLEY AND INTO THE GREAT
LAKES ON FRIDAY. THIS LOW PRESSURE TROUGH WILL BRING AN INCREASE IN
CLOUD COVER LATE TONIGHT AND INTO FRIDAY...BUT CEILINGS ACROSS THE
REGION WILL LIKELY REMAIN VFR. IT APPEARS THAT THE INITIAL SHOWERS
AND THUNDERSTORMS ASSOCIATED WITH THE LOW PRESSURE TROUGH WILL BE
DECAYING AS THEY MOVE EAST INTO EASTERN KY FRIDAY MORNING...BUT WOULD
NOT RULE OUT SOME OF THIS CONVECTION IMPACTING THE TAF SITES BY NOON.
THE EXACT TIMING AND LOCATION IS STILL UNCERTAIN...SO JUST WENT WITH
VCTS AT THIS TIME. THIS FIRST SURGE WILL DIE OUT BY EVENING AND
EXPECT THE CIGS TO SCATTER OUT. WINDS THROUGH THE PERIOD WILL BE
AROUND 10 KTS OR LESS...GENERALLY FROM THE SOUTH.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
446 AM EDT FRI MAY 31 2013
.SYNOPSIS...
HIGH PRESSURE REMAINS ANCHORED OFF THE MID ATLANTIC COAST THROUGH
SUNDAY. A COLD FRONT WILL BRING INCREASING RAIN CHANCES...AS IT
SLOWLY CROSSES THE AREA ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
VERY SIMILAR DAY WXWISE TO THU ON THE WAY FOR TODAY. EXPECTING
ANOTHER VERY WARM DAY, AS THE SFC RIDGE AND STRENGTHENING H5 RIDGE
ALOFT REMAINS QUASI- STATIONARY WELL OFFSHORE.
DRY WEATHER CONTINUES TODAY WITH PERSISTENT WARM/STABLE AIR ALOFT
AND A LACK OF AVAILABLE TRIGGERS FOR LIFT. HIGH-RES MODELS
(SPECIFICALLY THE HRRR AND SPC WRF) AGAIN PICKING UP THE THE
POTENTIAL FOR AN ISOLATED SHOWER OR TWO BLOWING UP ON AFTN
SEABREEZE OVER THE FAR SOUTHEAST PART OF THE CWA (AND ALSO ALONG
THE MASON-DIXON IN ASSN WITH A WEAK, SHEARED OUT SHORTWAVE
CROSSING WELL NORTH OF THE AKQ CWA). AS WITH YESTERDAY THOUGH,
RAIN CHC ACROSS LOCAL AREA REMAINS TOO SMALL TO INCLUDE POPS IN
THE FORECAST. THUS, HV CONTINUED TO CAP RAIN CHANCES AT 10% OR
LESS. HIGH TEMPERATURES AWAY FROM THE IMMEDIATE COAST AGAIN
GENERALLY ~90/L90S INLAND, LOW TO MID 80S AT IMMEDIATE COASTAL
AREAS.
CLEAR AND MILD OVERNIGHT...EARLY MORNING LOWS SAT MORNING IN THE
U60S TO NR 70.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
GRADUALLY WEAKENING H5 RIDGE OFF THE MID ATLANTIC COAST SHIFTS
SLIGHTLY TO THE EAST SATURDAY AND SUNDAY AHEAD OF APPROACHING
MID-LVL TROUGH, WHICH PUSHES FROM THE NORTHERN PLAINS TOWARDS THE
UPR GRT LAKES ON SUNDAY. HOWEVER, SFC/UPR LEVEL RIDGING OFFSHORE
WL REMAIN THE DOMINATE WX FEATURE THRU THE WEEKEND, BRINGING
CONTINUED SUMMER-LIKE CONDITIONS. LTL (IF ANY) TRIGGER EXISTS FOR
CONVECTION ON SAT, AS AIRMASS REMAINS LARGELY CAPPED. FCST
REMAINS DRY AS BEST CHCS FOR ANY CONVECTION WILL AGAIN BE CONFINED
OVER THE MTNS. HIGHS SAT IN THE U80S-L90S, THOUGH AGAIN COOLER AT
THE BEACHES DUE TO LCL AFTN SEA BREEZE EFFECTS.
PARTLY TO MOSTLY CLEAR SKY FOR MOST OF SAT NIGHT, THOUGH WL NEED
TO WATCH GFS, AS IT CONTINUES TO KEY IN ON POTENTIAL FOR SOME LOW
STRATUS OVER THE I-85 CORRIDOR BACK INTO THE CENTRAL NC PIEDMONT
LATE. ERY MORNING LOWS SUNDAY MORNING IN THE M-U60S.
AFTER ANY LINGERING STRATUS QUICKLY LIFTS/ERODES SUNDAY MORNING,
THE DAY STARTS OUT MAINLY SUNNY. HOWEVER, CLOUDS LOOK TO INCREASE
FROM THE WEST BY SUN AFTN AHEAD OF APPROACHING FRONTAL BOUNDARY.
SLIGHT CHC TO LOW CHC POPS STILL LOOK GOOD BY MID AFTN SUNDAY AS
TSRAS LOOK TO FIRE ALONG PRE-FRONTAL/LEE TROUGHING TO THE WEST AND
PUSH E-NE ACROSS OUR WESTERN TIER OF COUNTIES (WEST OF RIC) LATE
SUN AFTN. MORE IN THE WAY OF CLOUD COVER WILL BE BALANCED OUT BY
STRONG COMPRESSIONAL HEATING AHEAD OF THE FRONT, AGAIN YIELDING
HIGHS IN THE U80S TO NR 90. GIVEN DP TEMPS IN THE L-M60S (HIGHEST
JUST BEFORE DIURNAL MIXING KICKS IN JUST AFTER 12Z)...HEAT INDEX
VALUES XPCTD TO REMAIN WITHIN A DEGREE OR TWO OF ACTUAL TEMPS BOTH
DAYS.
ECMWF/GFS IN PRETTY GOOD AGREEMENT REGARDING FROPA/PCPN TIMING FOR
SUNDAY NIGHT AND MONDAY. FRONT SLOWLY APPROACHES, AND BEGINS TO
PUSH ACROSS THE WESTERN THIRD OF THE LOCAL AREA LATE SUNDAY
NIGHT/MONDAY MORNING. DUE TO THE LATE NIGHT/ERY MORNING TIMING,
INSTABILITY ATTM LOOKS TO BE MARGINAL AT BEST, SO WILL GO WITH ISO
T WORDING FOR NOW. STILL, AS PW VALUES SHOOT UPWARDS OF 1.75"
AREA-WIDE SUNDAY NIGHT, RAIN CHANCES ARE LOOKING INCREASINGLY
FAVORABLE ACROSS THE PIEDMONT AFTER 00Z MON/8PM SUNDAY NIGHT.
THUS, WL GO WITH LKLY POP WEST OF I-95 LT SUNDAY NIGHT, WITH CHCS
INCREASING FARTHER EAST AFTER MIDNIGHT THRU DAWN MONDAY MORNING.
GIVEN THE CONSIDERABLE CLDS/PCPN, WL GO CLOSER TO EURO STATISTICAL
GUIDANCE, WHICH IS ABT A CATEGORY ABOVE 00Z/31 MEX NUMBERS. ERY
MORNING LOWS MON MORNING RIGHT AROUND 70/LOW 70S.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
LONG TERM PERIOD BEGINS W/ THE FRONT SLOWLY MOVING ACRS THE AREA
MON, WITH SHRAS/TSTMS EXPECTED ACROSS THE AREA. ALTHO WAA IS
WEAK...DEEP LAYER MOISTURE...MID-LVL S/W ENERGY AND UPR-LVL
DIVERGENCE CONTINUE TO WARRANT LIKELY POPS...CONTINUING INTO SE
AREAS MON NGT. GIVEN THE RAIN AND CLDS...TEMPS MON WILL MAX OUT IN
THE UPR 70S TO MID 80S. THE RAIN WILL END FROM W TO E EARLY TUE AS
THE FRONT SLIDES OFFSHORE. SFC HI PRES THEN BLDS IN FROM THE
NW...WITH HIGHS ONLY IN THE UPR 70S TO LO 80S ON TUE AND WED.
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
MAINLY S-SW WINDS ARE EXPECTED TO CONTINUE FOR THE 06Z TAF PERIOD
WITH ONE POSSIBLE EXCEPTION. WINDS AT ORF MAY BE INFLUENCED ONCE
AGAIN BY A BAY BREEZE AS SYNOPTIC WINDS WILL BE A BIT LIGHTER THAN
ON THURSDAY. MODELS ARE NOT CLEAR ON THE DIRECTION AND WENT VRBL AND
LIGHT. NO SUBSTANTIAL CLOUDINESS IS INDICATED SO KEPT SKC THROUGH
THE PERIOD.
THE TEMPERATURE DEW POINT SPREAD MAY LOWER TO 3 DEGREES OR LESS AT A
COUPLE OF THE TAF SITES. THE COMBINATION OF A STEADY S/SW WIND AND
DRY CONDITIONS AT THE SURFACE SHOULD PRECLUDE FOG FRIDAY MORNING.
OUTLOOK...HIGH PRESSURE REMAINS THE DOMINANT WX FEATURE ACROSS
THE REGION WITH DRY/VFR WX CONTINUING THROUGH SATURDAY. ISOLATED
THUNDERSTORMS WILL BE PSBL SUNDAY EVENING. THE CHANCES INCREASE
MONDAY AHEAD OF AN APPROACHING COLD FRONT.
&&
.MARINE...
WINDS WILL CONTINUE TO BE GENERALLY FROM THE SOUTH THROUGH THE
WEEKEND. WIND SPEEDS AT ELEVATED SITES ARE RUNNING SEVERAL KNOTS
HIGHER THAN THOSE NEAR THE SURFACE OF THE WATER DUE TO POOR MIXING
WITH THE COLD WATER. THIS SHOULD CONTINUE TO BE THE CASE THROUGH THE
WEEKEND.
CONDITIONS SHOULD REMAIN BELOW SCA CRITERIA THROUGH THE DAY
SATURDAY. SOUTHERLY WINDS MAY GAIN ENOUGH SOUTHERLY FETCH TO PRODUCE
MARGINAL 5 FOOT SEAS OVER THE NORTHERN COASTAL WATERS BY SATURDAY
NIGHT. HOWEVER...THE MAIN SCA EVENT SHOULD BEGIN SUNDAY NIGHT OVER
THE COASTAL WATERS NORTH OF CAPE CHARLES. ELSEWHERE...CONDITIONS
SHOULD BE JUST SHORT OF SCA AS A COLD FRONT APPROACHES THE REGION.
THE FRONT MOVES SLOWLY TO THE EAST MONDAY NIGHT AND TUESDAY. PRESENT
INDICATIONS ARE THAT THE POST FRONTAL ENVIRONMENT WILL FAIL TO
PRODUCE SCA BUT THIS MAY CHANGE.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...AIR QUALITY ALERT UNTIL MIDNIGHT EDT TONIGHT FOR MDZ021>024.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...MPR/MAM
LONG TERM...MAS
AVIATION...LSA
MARINE...LSA
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
349 AM EDT FRI MAY 31 2013
.SYNOPSIS...
HIGH PRESSURE REMAINS ANCHORED OFF THE MID ATLANTIC COAST THROUGH
SUNDAY. A COLD FRONT WILL BRING INCREASING RAIN CHANCES...AS IT
SLOWLY CROSSES THE AREA ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
VERY SIMILAR DAY WXWISE ON THE WAY TODAY. CONTINUED VERY WARM AS
THE SFC RIDGE AND STRENGTHENING H5 RIDGE ALOFT REMAINS QUASI-
STATIONARY WELL OFFSHORE.
DRY WEATHER CONTINUES TODAY WITH PERSISTENT WARM/STABLE AIR ALOFT
AND A LACK OF AVAILABLE TRIGGERS FOR LIFT. HIGH-RES MODELS
(SPECIFICALLY THE HRRR AND SPC WRF) AGAIN PICKING UP THE THE
POTENTIAL FOR AN ISOLATED SHOWER OR TWO BLOWING UP ON AFTN
SEABREEZE OVER THE FAR SOUTHEAST PART OF THE CWA (AND ALSO ALONG
THE MASON-DIXON IN ASSN WITH A WEAK, SHEARED OUT SHORTWAVE
CROSSING WELL NORTH OF THE AKQ CWA). AS WITH YESTERDAY THOUGH,
RAIN CHC ACROSS LOCAL AREA REMAINS TOO SMALL TO INCLUDE POPS IN
THE FORECAST. THUS, HV CONTINUED TO CAP RAIN CHANCES AT 10% OR
LESS. HIGH TEMPERATURES AWAY FROM THE IMMEDIATE COAST AGAIN
GENERALLY ~90/L90S INLAND, LOW TO MID 80S AT IMMEDIATE COASTAL
AREAS.
CLEAR AND MILD OVERNIGHT...EARLY MORNING LOWS SAT MORNING IN THE
U60S TO NR 70.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
GRADUALLY WEAKENING H5 RIDGE OFF THE MID ATLANTIC COAST SHIFTS
SLIGHTLY TO THE EAST SATURDAY AND SUNDAY AHEAD OF APPROACHING
MID-LVL TROUGH, WHICH PUSHES FROM THE NORTHERN PLAINS TOWARDS THE
UPR GRT LAKES ON SUNDAY. HOWEVER, SFC/UPR LEVEL RIDGING OFFSHORE
WL REMAIN THE DOMINATE WX FEATURE THRU THE WEEKEND, BRINGING
CONTINUED SUMMER-LIKE CONDITIONS. LTL (IF ANY) TRIGGER EXISTS FOR
CONVECTION ON SAT, AS AIRMASS REMAINS LARGELY CAPPED. FCST
REMAINS DRY AS BEST CHCS FOR ANY CONVECTION WILL AGAIN BE CONFINED
OVER THE MTNS. HIGHS SAT IN THE U80S-L90S...AGAIN COOLER AT THE
BEACHES DUE TO LCL AFTN SEA BREEZE EFFECTS.
PARTLY TO MOSTLY CLEAR SKY FOR MOST OF SAT NIGHT, THOUGH GFS
CONTINUES TO KEY IN ON POTENTIAL FOR SOME LOW STRATUS OVER THE
I-85 CORRIDOR BACK INTO THE CENTRAL NC PIEDMONT LATE. ERY MORNING
LOWS IN THE M-U60S.
AFTER ANY LINGERING STRATUS QUICKLY LIFTS/ERODES SUNDAY MORNING,
THE DAY STARTS OUT MAINLY SUNNY. HOWEVER, CLOUDS LOOK TO INCREASE
FROM THE WEST SUN AFTN AHEAD OF APPROACHING FRONTAL BOUNDARY.
SLIGHT CHC TO LOW CHC POPS STILL LOOK GOOD BY MID AFTN SUNDAY AS
TSRAS LOOK TO FIRE ALONG PRE-FRONTAL/LEE TROUGHING TO THE WEST
AND PUSH E-NE ACROSS OUR WESTERN TIER OF COUNTIES LATE SUN AFTN.
MORE CLOUD COVER BALANCED OUT BY STRONG COMPRESSIONAL HEATING
AHEAD OF THE FRONT WILL AGAIN YIELD HIGHS IN THE U80S TO NR 90.
GIVEN DP TEMPS IN THE L-M60S (HIGHEST JUST BEFORE DIURNAL MIXING
KICKS IN JUST AFTER 12Z)...HEAT INDEX VALUES XPCTD TO REMAIN
WITHIN A DEGREE OR TWO OF ACTUAL TEMPS BOTH DAYS.
ECMWF/GFS IN PRETTY GOOD AGREEMENT REGARDING FROPA/PCPN TIMING FOR
SUNDAY NIGHT AND MONDAY. FRONT SLOWLY APPROACHES, AND BEGINS TO
PUSH ACROSS THE LOCAL AREA LATE SUNDAY NIGHT/MONDAY MORNING. DUE
TO THE LATE NIGHT/ERY MORNING TIMING, INSTABILITY ATTM LOOKS TO BE
MARGINAL AT BEST, SO WILL GO WITH ISO T WORDING FOR NOW. STILL,
AS PW VALUES SHOOT UPWARDS OF 1.75" AREA-WIDE SUNDAY NIGHT, RAIN
CHANCES ARE LOOKING INCREASINGLY FAVORABLE ACROSS THE PIEDMONT
AFTER 00Z MON/8PM SUNDAY NIGHT. THUS, WL GO WITH LKLY POP WEST OF
I-95 LT SUNDAY NIGHT, WITH CHCS INCREASING FARTHER EAST AFTER
MIDNIGHT THRU DAWN MONDAY MORNING. GIVEN THE CONSIDERABLE CLDS/PCPN,
WL GO CLOSER TO EURO STATISTICAL GUIDANCE, WHICH IS ABT A CATEGORY
ABOVE 00Z/31 MEX NUMBERS. ERY MORNING LOWS MON MORNING RIGHT
AROUND 70/LOW 70S.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
LONG TERM PERIOD STARTS OUT W/ THE FRONT SLOWLY MOVING ACRS THE
AREA MON, WITH SHRAS/TSTMS ACROSS THE AREA. ALTHO WAA IS
WEAK...DEEP LAYER MOISTURE...MID-LVL S/W ENERGY AND UPR-LVL
DIVERGENCE CONTINUE TO WARRANT LIKELY POPS...CONTINUING INTO SE
AREAS MON NGT. GIVEN THE RAIN AND CLDS...TEMPS MON WILL MAX OUT
IN THE UPR 70S TO MID 80S. THE RAIN WILL END FROM W TO E EARLY TUE
AS THE FRONT SLIDES OFFSHORE. SFC HI PRES THEN BLDS IN FROM THE
NW...WITH HIGHS ONLY IN THE UPR 70S TO LO 80S ON TUE AND WED.
&&
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
MAINLY S-SW WINDS ARE EXPECTED TO CONTINUE FOR THE 06Z TAF PERIOD
WITH ONE POSSIBLE EXCEPTION. WINDS AT ORF MAY BE INFLUENCED ONCE
AGAIN BY A BAY BREEZE AS SYNOPTIC WINDS WILL BE A BIT LIGHTER THAN
ON THURSDAY. MODELS ARE NOT CLEAR ON THE DIRECTION AND WENT VRBL AND
LIGHT. NO SUBSTANTIAL CLOUDINESS IS INDICATED SO KEPT SKC THROUGH
THE PERIOD.
THE TEMPERATURE DEW POINT SPREAD MAY LOWER TO 3 DEGREES OR LESS AT A
COUPLE OF THE TAF SITES. THE COMBINATION OF A STEADY S/SW WIND AND
DRY CONDITIONS AT THE SURFACE SHOULD PRECLUDE FOG FRIDAY MORNING.
OUTLOOK...HIGH PRESSURE REMAINS THE DOMINANT WX FEATURE ACROSS
THE REGION WITH DRY/VFR WX CONTINUING THROUGH SATURDAY. ISOLATED
THUNDERSTORMS WILL BE PSBL SUNDAY EVENING. THE CHANCES INCREASE
MONDAY AHEAD OF AN APPROACHING COLD FRONT.
&&
.MARINE...
WINDS WILL CONTINUE TO BE GENERALLY FROM THE SOUTH THROUGH THE
WEEKEND. WIND SPEEDS AT ELEVATED SITES ARE RUNNING SEVERAL KNOTS
HIGHER THAN THOSE NEAR THE SURFACE OF THE WATER DUE TO POOR MIXING
WITH THE COLD WATER. THIS SHOULD CONTINUE TO BE THE CASE THROUGH THE
WEEKEND.
CONDITIONS SHOULD REMAIN BELOW SCA CRITERIA THROUGH THE DAY
SATURDAY. SOUTHERLY WINDS MAY GAIN ENOUGH SOUTHERLY FETCH TO PRODUCE
MARGINAL 5 FOOT SEAS OVER THE NORTHERN COASTAL WATERS BY SATURDAY
NIGHT. HOWEVER...THE MAIN SCA EVENT SHOULD BEGIN SUNDAY NIGHT OVER
THE COASTAL WATERS NORTH OF CAPE CHARLES. ELSEWHERE...CONDITIONS
SHOULD BE JUST SHORT OF SCA AS A COLD FRONT APPROACHES THE REGION.
THE FRONT MOVES SLOWLY TO THE EAST MONDAY NIGHT AND TUESDAY. PRESENT
INDICATIONS ARE THAT THE POST FRONTAL ENVIRONMENT WILL FAIL TO
PRODUCE SCA BUT THIS MAY CHANGE.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...AIR QUALITY ALERT UNTIL MIDNIGHT EDT TONIGHT FOR MDZ021>024.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...MPR/MAM
LONG TERM...MAS
AVIATION...LSA
MARINE...LSA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
451 AM CDT FRI MAY 31 2013
.UPDATED FOR 12Z AVIATION DISCUSSION...
ISSUED AT 441 AM CDT FRI MAY 31 2013
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 330 AM CDT FRI MAY 31 2013
EARLY MORNING WATER VAPOR IMAGERY TOGETHER WITH THE PRESSURE OF THE
1.5PVU SURFACE SHOWED A NARROW RIBBON OF POTENTIAL VORTICITY
PROTRUDING DOWN TO THE 450/500MB LEVEL. THIS PV RESERVOIR
ORIGINATED UPSTREAM OFF THE BRITISH COLUMBIA COAST...EXTENDED
SOUTHEAST ACROSS THE KS/NE BORDER...AND CURLED UP OVER THE UPPER
MIDWEST. OVERLAYING THE 300MB WINDS SHOWED AN AREA OF POSITIVE
VORTICITY OWING TO THE EASTERLY WINDS OF 30KTS ON THE POLEWARD SIDE
OF +100KT WESTERLY JET. AT THE SURFACE A 991 LOW WAS LOCATED BENEATH
THE LEADING EDGE OF THE PV GRADIENT ALONG THE SD/ND BORDER...WITH A
SURFACE COLD FRONT DRAPED ON THE EASTERN SIDE OF THE MISSOURI
RIVER VALLEY.
FOR TODAY THE 00Z RUN OF THE HOPWRF AND FEW RUNS OF
THE HRRR SHOWS ANOTHER ACTIVE DAY SOUTH AND EAST OF THE CWA WITH
SEVERAL THUNDERSTORM COMPLEXES EXPECTED TO DEVELOP AS THE DEEP SHEAR
ASSOCIATED WITH THE AFOREMENTIONED UPPER LEVEL JET MOVE ACROSS THE
MISSISSIPPI RIVER VALLEY. MEANWHILE IT SHOULD BE MAINLY DRY FOR THE
FIRST HALF OF FRIDAY ACROSS THE CWA. IN FACT FORECAST SOUNDINGS VIA
THE RAP SUPPORT MOSTLY SUNNY SKIES DURING THE MORNING HOURS.
HOWEVER...WITH THE VORT MAX ROTATING OVERHEAD EXPECT INCREASING
CLOUDS WITH SHOWERS/THUNDERSTORMS AS THE ATMOSPHERE DESTABILIZES BY
MID AFTERNOON...MORESO THAN THE HIRES MODELS WOULD INDICATE. THE
BEST DEEP LAYER SHEAR WILL BE ACROSS EASTERN IOWA AND WISCONSIN...SO
SEVERE THREAT IS LOW IN MINNESOTA...BUT COULD SEE SOME STRONGER
STORMS IN WEST CENTRAL WISCONSIN. BUFR FORECAST SOUNDINGS SHOW
ROUGHLY 1000J/KG OF MLCAPE AND FREEZING LEVELS AROUND 9-10KFT
AGL...SO WOULDNT BE SURPRISED TO GET SOME SMALL HAIL AND GUSTY
WINDS WITH A FEW OF THE STRONGER CELLS. THE BEST CHANCE FOR DEEPER
CONVECTION WILL BE IN EASTERN MN AND WESTERN WI. ON FRIDAY NIGHT
THE INSTABILITY WILL DECREASE GIVING WAY TO LIGHT WINDS AND LOW
STRATUS AS THE OCCLUDED CYCLONE SLOWLY WOBBLES EASTWARD. A FEW
LIGHT RAIN SHOWERS DEVELOP ACROSS THE WESTERN HALF OF THE CWA AS
INDICATED BY THE LOW LEVEL SATURATION SHOWN IN THE BUFR SOUNDINGS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 330 AM CDT FRI MAY 31 2013
CLOSED UPPER CIRCULATION OVER THE REGION SATURDAY. IT SHOULD
PROVIDE GENERAL CLOUDINESS AND THE THREAT OF SHOWERS MUCH OF THE
DAY. AS THE CIRCULATION PIVOTS EAST NORTHEAST AND WEAKENS...MODELS
SUGGEST SOME WEAK SURFACE BASED CAPE AND SOME SLIGHTLY NEGATIVE
BEST LI`S OVER EASTERN AREAS...INTO THE AFTERNOON. WILL NEED SOME
BREAKS IN THE CLOUDS TO GENERATE ANY SIGNIFICANT DESTABILIZATION.
OPTED TO MENTION ISOLATED THUNDER OVER THE EAST PORTION OF THE
CWA...MAINLY IN THE AFTERNOON. WITH SIGNIFICANT CLOUD COVER
AROUND...TEMPERATURES MAY NOT GET OUT OF THE 50S OVER THE WEST AND
WILL REMAIN IN THE 60S EAST.
THIS INITIAL SYSTEM MOVES EAST...AND BECOMES MORE PROGRESSIVE AS
THE NEXT SIGNIFICANT TROUGH MOVES ASHORE OVER THE PACIFIC
NORTHWEST LATER SUNDAY. THIS SHOULD PROVIDE A CLEARING
TREND...ALONG WITH DRIER CONDITIONS SUNDAY INTO MONDAY. SOME
RETURN FLOW...WARM AIR ADVECTION PATTERN DEVELOPS DURING THE DAY
MONDAY...MAINLY OVER THE FAR WEST. THE WESTERN CLOSED CIRCULATION
MOVES SLOWLY EAST OVER THE REGION...AND APPEARS TO AFFECT THE AREA
FOR THE REMAINDER OF THE WEEK. THIS WILL AGAIN PROVIDE A LONG
PERIOD OF CLOUDINESS AND THE THREAT OF SHOWERS AND THUNDERSTORMS
TO THE CWA. TUESDAY AND WEDNESDAY LOOK TO BE THE WETTEST DAYS...BUT
THE SHOWERY WEATHER PATTERN WILL CONTINUE THROUGH THURSDAY. THE
BELOW NORMAL TEMPERATURE PATTERN WILL ALSO CONTINUE INTO THE
FIRST PART OF JUNE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 441 AM CDT FRI MAY 31 2013
MAINLY VFR CONDITIONS THIS MORNING...WITH AFTERNOON SHOWERS AND
THUNDERSTORMS DEVELOPING...FOLLOWED BY LOWER CIGS ACROSS THE
WEST FRIDAY NIGHT. SURFACE LOW OVER THE DAKOTAS WILL MOVE
EASTWARD...WITH MVFR CIGS POSSIBLE AT KAXN THIS MORNING. LATER
THIS AFTERNOON CLOUDS WILL INCREASE...WITH SHOWERS POSSIBLE AT
KAXN/KSTC/KRWF...AND THUNDERSTORMS AT KMSP/KRNH/KEAU. THESE WILL
TAPER OFF OVERNIGHT WHILE MVFR CIGS MOVE IN FROM THE NORTHWEST.
KMSP...
VFR CONDITIONS THIS MORNING WITH SSW WIND INCREASING. LATER THIS
AFTERNOON EXPECT TO HAVE SOME SHOWERS AND THUNDERSTORMS SCATTERED
ABOUT. BEST CHANCE WILL BE BETWEEN 22-24Z. THIS WILL BE FOLLOWED
BY VFR CONDITIONS.
/OUTLOOK FOR KMSP/
SAT...MVFR WITH -SHRA. WINDS NW AT 10G20KTS.
SUN...VFR. WINDS NNW AT 10KTS.
MON...VFR WITH -SHRA POSSIBLE LATE. WINDS ESE AT 10KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JRB
LONG TERM...DWE
AVIATION...JRB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
330 AM CDT FRI MAY 31 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 330 AM CDT FRI MAY 31 2013
EARLY MORNING WATER VAPOR IMAGERY TOGETHER WITH THE PRESSURE OF THE
1.5PVU SURFACE SHOWED A NARROW RIBBON OF POTENTIAL VORTICITY
PROTRUDING DOWN TO THE 450/500MB LEVEL. THIS PV RESERVOIR
ORIGINATED UPSTREAM OFF THE BRITISH COLUMBIA COAST...EXTENDED
SOUTHEAST ACROSS THE KS/NE BORDER...AND CURLED UP OVER THE UPPER
MIDWEST. OVERLAYING THE 300MB WINDS SHOWED AN AREA OF POSITIVE
VORTICITY OWING TO THE EASTERLY WINDS OF 30KTS ON THE POLEWARD SIDE
OF +100KT WESTERLY JET. AT THE SURFACE A 991 LOW WAS LOCATED BENEATH
THE LEADING EDGE OF THE PV GRADIENT ALONG THE SD/ND BORDER...WITH A
SURFACE COLD FRONT DRAPED ON THE EASTERN SIDE OF THE MISSOURI
RIVER VALLEY.
FOR TODAY THE 00Z RUN OF THE HOPWRF AND FEW RUNS OF
THE HRRR SHOWS ANOTHER ACTIVE DAY SOUTH AND EAST OF THE CWA WITH
SEVERAL THUNDERSTORM COMPLEXES EXPECTED TO DEVELOP AS THE DEEP SHEAR
ASSOCIATED WITH THE AFOREMENTIONED UPPER LEVEL JET MOVE ACROSS THE
MISSISSIPPI RIVER VALLEY. MEANWHILE IT SHOULD BE MAINLY DRY FOR THE
FIRST HALF OF FRIDAY ACROSS THE CWA. IN FACT FORECAST SOUNDINGS VIA
THE RAP SUPPORT MOSTLY SUNNY SKIES DURING THE MORNING HOURS.
HOWEVER...WITH THE VORT MAX ROTATING OVERHEAD EXPECT INCREASING
CLOUDS WITH SHOWERS/THUNDERSTORMS AS THE ATMOSPHERE DESTABILIZES BY
MID AFTERNOON...MORESO THAN THE HIRES MODELS WOULD INDICATE. THE
BEST DEEP LAYER SHEAR WILL BE ACROSS EASTERN IOWA AND WISCONSIN...SO
SEVERE THREAT IS LOW IN MINNESOTA AND EVEN WEST CENTRAL WISCONSIN.
BUFR FORECAST SOUNDINGS SHOW ROUGHLY 1000J/KG OF MLCAPE AND FREEZING
LEVELS AROUND 9-10KFT AGL...SO COULD SEE SOME SMALL HAIL AND GUSTY
WINDS WITH A FEW OF THE STRONGER CELLS. THE BEST CHANCE FOR DEEPER
CONVECTION WILL BE IN EASTERN MN AND WESTERN WI. ON FRIDAY NIGHT THE
INSTABILITY WILL DECREASE GIVING WAY TO LIGHT WINDS AND LOW STRATUS
AS THE OCCLUDED CYCLONE SLOWLY WOBBLES EASTWARD. A FEW LIGHT RAIN
SHOWERS DEVELOP ACROSS THE WESTERN HALF OF THE CWA AS INDICATED BY
THE LOW LEVEL SATURATION SHOWN IN THE BUFR SOUNDINGS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 330 AM CDT FRI MAY 31 2013
CLOSED UPPER CIRCULATION OVER THE REGION SATURDAY. IT SHOULD
PROVIDE GENERAL CLOUDINESS AND THE THREAT OF SHOWERS MUCH OF THE
DAY. AS THE CIRCULATION PIVOTS EAST NORTHEAST AND WEAKENS...MODELS
SUGGEST SOME WEAK SURFACE BASED CAPE AND SOME SLIGHTLY NEGATIVE
BEST LI`S OVER EASTERN AREAS...INTO THE AFTERNOON. WILL NEED SOME
BREAKS IN THE CLOUDS TO GENERATE ANY SIGNIFICANT DESTABILIZATION.
OPTED TO MENTION ISOLATED THUNDER OVER THE EAST PORTION OF THE
CWA...MAINLY IN THE AFTERNOON. WITH SIGNIFICANT CLOUD COVER
AROUND...TEMPERATURES MAY NOT GET OUT OF THE 50S OVER THE WEST AND
WILL REMAIN IN THE 60S EAST.
THIS INITIAL SYSTEM MOVES EAST...AND BECOMES MORE PROGRESSIVE AS
THE NEXT SIGNIFICANT TROUGH MOVES ASHORE OVER THE PACIFIC
NORTHWEST LATER SUNDAY. THIS SHOULD PROVIDE A CLEARING
TREND...ALONG WITH DRIER CONDITIONS SUNDAY INTO MONDAY. SOME
RETURN FLOW...WARM AIR ADVECTION PATTERN DEVELOPS DURING THE DAY
MONDAY...MAINLY OVER THE FAR WEST. THE WESTERN CLOSED CIRCULATION
MOVES SLOWLY EAST OVER THE REGION...AND APPEARS TO AFFECT THE AREA
FOR THE REMAINDER OF THE WEEK. THIS WILL AGAIN PROVIDE A LONG
PERIOD OF CLOUDINESS AND THE THREAT OF SHOWERS AND THUNDERSTORMS
TO THE CWA. TUESDAY AND WEDNESDAY LOOK TO BE THE WETTEST DAYS...BUT
THE SHOWERY WEATHER PATTERN WILL CONTINUE THROUGH THURSDAY. THE
BELOW NORMAL TEMPERATURE PATTERN WILL ALSO CONTINUE INTO THE
FIRST PART OF JUNE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1110 PM CDT THU MAY 30 2013
MAIN COMPLICATIONS WITH THIS SET ARE TWOFOLD. FIRST...THE ONGOING
CONVECTION OVER SW MN...WILL IT HOLD TOGETHER TO REACH THE
TERMINALS. SECOND...WILL THERE BE CONVECTION LATE TMRW AFTN/TMRW
EVE AT THE TERMINALS. FOR THE SW MN ACTIVITY...THE SHWRS/TSTMS ARE
MOVING INTO A REGION OF INCRD INSTABILITY AND AN ENVIRONMENT THAT
STILL HAS DEWPOINTS IN THE MID 60S. THE ACTIVITY MAY DIMINISH
SOMEWHAT IN STRENGTH...MAINLY LOSING THUNDER...BUT AM MORE THAN
MODERATELY CONFIDENT THAT SHWRS WILL REACH ALL TERMINALS OVER THE
NEXT FEW HOURS SO HAVE INCLUDED STAGGERED TEMPO GROUPS FOR MVFR
VSBY SHWRS. HAVE ALSO INCLUDED MVFR CIGS IN THE PRE-DAWN HRS
BEFORE VFR CONDS TAKE HOLD THRU MUCH OF THE DAY. GOING INTO LATE
TMRW AFTN...MOST SHORT-TERM MODELS HOLD THE NEXT BATCHES OF
CONVECTION OVER IA AND INTO FAR SW WI...WHILE THE BROADER-SCALE
MODELS INDICATE CONVECTION MAY OVERSPREAD SRN-CENTRAL MN. HAVE
PLAYED THINGS CONSERVATIVELY AND HELD OFF PRECIP MENTION ATTM TO
GIVE MORE TIME FOR MODELS TO RESOLVE THE SITUATION AND JUST
UTILIZED LOWER-END VFR CIGS. SE WINDS AT THE START GRADUALLY VEER
TO S AND SW THRU THIS TAF DURATION...AND AGAIN BECOME GUSTY TMRW
AFTN INTO TMRW EVE.
KMSP...KEPT CONDS VFR THROUGHOUT THIS SET BUT THERE ARE A FEW TIME
PERIODS WHERE MVFR CONDS ARE POSSIBLE. FIRST...CONVECTION OVER SW
MN MAY REACH MSP BETWEEN 07Z-10Z. ALTHOUGH THUNDER IS NOT
EXPECTED..SOME HEAVIER BURSTS OF RAIN MAY DROP VSBY INTO MVFR
RANGE. BEHIND THIS RAIN FOR THE REMAINDER OF THE PRE-DAWN
HRS...VFR CIGS ARE CURRENTLY ADVERTISED BUT SEEING CIGS DROP INTO
THE UPPER MVFR RANGE WOULD NOT AT ALL BE UNREASONABLE. AM NOT
THINKING CIGS DROP BELOW 2 KFT. CLOUDS THEN SCATTER OUT SHORTLY
AFTER SUNRISE AND REMAIN VFR THRU THE DAY. LOWER-END VFR CIGS
RETURN LATE IN THE DAY THEN THERE IS HIGH UNCERTAINTY REGARDING
CONVECTION RETURNING LATE AFTN THRU THE EVE HOURS. HAVE LEFT IT
OUT ATTM DUE TO LOW CONFIDENCE SO WILL LET LATER MODEL RUNS AND
TAF ISSUANCES RESOLVE THIS ISSUE.
/OUTLOOK FOR KMSP/
SAT...MVFR CIGS POSSIBLE. SHRA LIKELY. WINDS WNW 5-10 KTS.
SUN...MVFR CIGS POSSIBLE EARLY. WINDS N 5 KTS.
MON...VFR. WINDS SE 5 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...LS
LONG TERM...DWE
AVIATION...JPC
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
411 AM CDT Fri May 31 2013
.SHORT TERM...(Today and Tonight)
Issued at 410 AM CDT FRI MAY 31 2013
Convection early this morning will persist through sunrise, with the
potential for more storms again this afternoon. Environment across
eastern Kansas and northern Missouri remains somewhat stabilized
from the the excessive rain the region received Thursday, however a
speed max ejecting through the Central Plains early this morning has
brought considerable focus back to areas from central Kansas east
into west central Missouri. Moisture advection within the speed max
has proven more than sufficient to initiate thunderstorms early this
morning. Storms early this morning are elevated in nature, thanks to
the stable boundary layer, but source region for the speed max is,
and will continue to, tap MUCAPE values across southern Kansas and
Oklahoma around 3000 J/KG, with effective shear values ranging above
50 knots. This will make storms through the early morning hours
rather volatile, with large hail and torrential rain the primary
threats. Activity through sunrise will generally range between
Highway 50 and Highway 36, as this region will be the focus for
continued mass convergence as long as the speed max is moving
through. Speed max will be to veer off after sunrise, likely
allowing the storms to transit from intense thunderstorms into
widespread rain for several hours this morning, therefore the severe
thunderstorm watch in effect for parts of our forecast area this
morning only runs through 8 AM.
Thunderstorm activity from this morning will likely take much of the
morning to run its course, bringing more saturating rain to the
region. Potential for redevelopment is there for the afternoon hours
if this mornings storms dissipate quickly enough to allow for
surface destabilization later on. Storm initialization should get a
boost this afternoon as a front across eastern Nebraska into central
Kansas begins to sweep through northern Missouri as the parent
circulation across the Northern Plains begins to shift farther east.
However, focus for afternoon convection should set up a little
farther east and south, limiting the likely POPs to the southeastern
half of the outlook area, from east central Kansas through northeast
Missouri. Large hail and torrential rain continue to look like the
major threats later this afternoon into this evening.
.LONG TERM...(Saturday through Thursday)
Issued at 410 AM CDT FRI MAY 31 2013
Looking into the weekend, it finally appears that we will have a
small respite from the storms. Parent trough giving us our current
round of storms will finally transit far enough east to take the
focus off the Plains States. This presents us with a dry forecast
after any potential lingering storm activity Saturday morning fades
away. Currently, forecast looks dry through Monday, with below
normal temperatures --Sunday might not make it out of the 60s--.
Unfortunately, our forecast does not remain dry. By Monday night,
models are advertising the beginning of another round of rain as yet
another trough begins to swing out of the Pacific Northwest into the
Northern Plains, interacting with the shortwave ridge that will be
in place. Confidence is not high enough to say that next work week
will be like this past work week, but the potential looks to be
there for more excessive rainfall next week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday Night)
Issued at 1220 AM CDT FRI MAY 31 2013
Scattered convection forming along a west-east band from central KS
into west central MO is likely the start of a convective complex that
will evolve overnight as the southerly low level jet over central KS
and OK ramps up. The 00z NAM and latest HRRR seem to have the nest
handle on the current situation and followed the general theme of
increasing convective activity into the terminals as we move into the pre-
dawn hours of Friday morning. With increasing confidence on a
convective complex forming have lowered ceilings into the MVFR
category with MVFR visibilities. Should the expected complex take
dead aim on any of the terminals the risk of IFR
ceilings/visibilities will increase...and most likely in the 10-13z
time period.
Should see convection drop off considerably by mid morning with
ceiling improving to VFR. Still the potential for late
afternoon/early evening re-development of convection but with
continued low confidence it will affect the KMCI/KMKC terminals.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...FLASH FLOOD WATCH through this evening FOR KSZ025-057-060-
102>105.
MO...FLASH FLOOD WATCH through this evening FOR MOZ001>008-011>017-
020>025-028>033-037>040-043>046-053-054.
&&
$$
SHORT TERM...Cutter
LONG TERM...Cutter
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1220 AM CDT Fri May 31 2013
.UPDATE...
Issued at 1000 PM CDT THU MAY 30 2013
Adjusted short term forecast for current radar/satellite/model
trends. Except for a few isolated cells over far nw MO and east
central KS looking quiet for a few more hours. However, already
seeing signs on satellite/radar over central KS. The rapid increase
of alto-cumulus clouds and elevated returns is signaling the rapid
redevelopment of the low level jet. The 00z NAM is noticeably
stronger with the h8 winds and this seems reasonable. The 00z NAM,
HRRR and RAP all generate rapid convective development on the nose of
the low level jet and spread it across east central KS and west
central MO during the pre-dawn hours. Heavy rains and near-severe
storms are expected between 08z-14z Friday over this region.
&&
.SHORT TERM...(This Evening through Friday)
Issued at 325 PM CDT THU MAY 30 2013
Leading edge of storms should move east of the forecast area by 4 or
so leaving just the trailing stratiform area of rainfall with
embedded convection through the early evening. So through this
evening the chances of rain/embedded storms will diminish from west
to east. The focus then shifts to tonight for the possibility of
convection erupting in eastern Kansas and then spreading into
western Missouri. There is a quite a bit of uncertainty with how
things may evolve tonight as several short-range models keep things
quiet overnight. However, the more reliable HRRR, which has been
handling today`s convection very well, has been consistent in
developing convection somewhere across northeastern Kansas and
moving into west central and northwestern Missouri. This roughly
corresponds to an area of strong isentropic lift with a focusing of
the LLJ depicted by the GFS. There should be enough instability and
shear to lead to storm organization so a few severe storms are
possible with large hail the biggest threat with damaging winds
possible as well. Will keep the flash flood watch going as is given
recent heavy rains across northern Missouri and persistent moderate
to heavy rain across the southern portions of the forecast and the
uncertainty with where any heavy rain may set up tonight. Some areas
within the watch area have good chance of seeing heavy rainfall
tonight and some much river flooding ongoing and already saturated
soils, it won`t take much more rain to lead to rapid runoff and
flash flooding.
.LONG TERM...(Friday Night through Thursday)
Issued at 325 PM CDT THU MAY 30 2013
Cold front will slide through the forecast area Friday night,
pushing the threat for thunderstorms southeast of the area.
Elongated area of high pressure will build into much of the Plains
over the weekend providing dry conditions and comfortable
temperatures. Cold air advection on Saturday and Sunday will keep
highs in the upper 60 and lower 70s.
Warm air advection on the back side of this area of high pressure
will set the stage for an increase in rain chances next week.
Initial rain chances will begin early Tuesday when a weak shortwave
will eject into the Plains ahead of a deeper wave digging into the
Upper Midwest. This system will eventually drop a cold front and
associated chances for showers and thunderstorms into the area by
mid-week, though there are still considerable model differences with
the timing of this activity.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday Night)
Issued at 1220 AM CDT FRI MAY 31 2013
Scattered convection forming along a west-east band from central KS
into west central MO is likely the start of a convective complex that
will evolve overnight as the southerly low level jet over central KS
and OK ramps up. The 00z NAM and latest HRRR seem to have the nest
handle on the current situation and followed the general theme of
increasing convective activity into the terminals as we move into the pre-
dawn hours of Friday morning. With increasing confidence on a
convective complex forming have lowered ceilings into the MVFR
category with MVFR visibilities. Should the expected complex take
dead aim on any of the terminals the risk of IFR
ceilings/visibilities will increase...and most likely in the 10-13z
time period.
Should see convection drop off considerably by mid morning with
ceiling improving to VFR. Still the potential for late
afternoon/early evening re-development of convection but with
continued low confidence it will affect the KMCI/KMKC terminals.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...FLASH FLOOD WATCH through this evening FOR KSZ025-057-060-
102>105.
MO...FLASH FLOOD WATCH through this evening FOR MOZ001>008-011>017-
020>025-028>033-037>040-043>046-053-054.
&&
$$
UPDATE...MJ
SHORT TERM...CDB
LONG TERM...Hawblitzel
AVIATION...MJ
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1158 PM CDT THU MAY 30 2013
.UPDATE...
ISSUED AT 840 PM CDT THU MAY 30 2013
CONVECTIVE TRENDS ARE PROCEEDING ABOUT AS ANTICIPATED THIS
EVENING. WHILE MUCH OF THE SHORT TERM UPDATING WILL BE REACTIVE
FOR THE REST OF THE NIGHT...GENERALLY SPEAKING I EXPECT THE LINE
OF STORMS NOW MOVING THROUGH SOUTHWEST/SOUTH CENTRAL MISSOURI TO
CONTINUE MOVING STEADILY EAST FOR THE REST OF THE EVENING INTO THE
OVERNIGHT HOURS. THE RAP CONTINUES TO SHOW A VERY STRONG LOW LEVEL
JET WITH TREMENDOUS MOISTURE CONVERGENCE OVER THE AREA FOR MUCH OF
THE REST OF THE NIGHT...AND THE HRRR SLOWS THE LINE FURTHER OVER
SOUTHERN AND EASTERN SECTIONS OF THE CWFA. IT ALSO DEVELOPS THE
CONVECTION NOW PERCOLATING OVER CENTRAL AND EASTERN KANSAS INTO
ANOTHER HEAVY RAIN PRODUCING MCS BEFORE BY 10Z AND IT MOVES EAST INTO
OUR AREA BY AROUND 12Z. DUE TO THE POTENTIAL FOR ADDITIONAL HEAVY
RAIN TONIGHT AND TOMORROW MORNING...AM GOING TO EXPAND THE FLASH
FLOOD WATCH TO THE REMAINDER OF THE AREA STARTING IMMEDIATELY AND
CONTINUING TO 12Z SATURDAY.
CARNEY
&&
.SHORT TERM...(THROUGH LATE TONIGHT)
ISSUED AT 240 PM CDT THU MAY 30 2013
TORNADO WATCH CONTINUES UNTIL 8 PM. ATMOSPHERE OUTSIDE OF OUTFLOW
COOLED AIR HAS BECOME QUITE UNSTABLE WITH MLCAPES ABOVE 2000 J/KG.
AT THE SAME TIME...DEEP LAYER SHEAR IS INCREASING IN RESPONSE TO
APPROACHING TROUGH CURRENTLY OVER THE CENTRAL PLAINS. THIS TROUGH
IS THE MAIN FOCUS FOR LARGE SCALE ASCENT TONIGHT AND CONSEQUENTLY IT
WILL DETERMINE THE OVERALL PRECIPITATION TRENDS. RAP SHOWS THIS
TROUGH MOVING ACROSS THE CWA AROUND 06Z...SO CURRENT THINKING IS
THAT LINE OF STORMS OVER WESTERN MO WILL CONTINUE TO SLOWLY MOVE
EAST ACROSS THE AREA LATER THIS AFTERNOON AND EVENING.
AFOREMENTIONED INSTABILITY AND SHEAR STILL FAVORS THE POTENTIAL FOR
A FEW SUPERCELLS OR ORGANIZED MULTI-CELLS THAT COULD PRODUCE LARGE
HAIL AND DAMAGING WINDS. LOW LEVEL SHEAR ALSO SUGGESTS THAT ONE OR
TWO TORNADOES COULD FORM IN THE STRONGER STORMS. STILL LOOKS
REASONABLE THAT WESTERN MO LINE WILL EXIT THE EASTERN COUNTIES LATER
THIS EVENING. OUTFLOW FROM THE LINE WILL LIKELY STALL OVER SOUTHERN
MO...SO KEPT CHANCE OF THUNDERSTORMS GOING IN THE SOUTHERN CWA INTO
THE OVERNIGHT HOURS. STILL EXPECT REDEVELOPMENT OF THUNDERSTORMS
OVER WESTERN MO ON THE NOSE OF THE LOW LEVEL JET OVERNIGHT THAT WILL
MOVE INTO NORTHEAST AND CENTRAL MO TOWARD 12Z.
FLASH FLOOD WATCH WILL CONTINUE AS IS. HEAVIEST RAINFALL WILL FOCUS
OVER THE WATCH AREA TONIGHT AND THE SOUTHERN AND EASTERN COUNTIES
HAVE HIGH FLASH FLOOD GUIDANCE. ATMOSPHERE IS VERY MOIST AND DEEP
LAYER FLOW FAVORS TRAINING TONIGHT.
.LONG TERM...(FRIDAY THROUGH NEXT THURSDAY)
ISSUED AT 240 PM CDT THU MAY 30 2013
CONVECTIVE TRENDS ARE SOMEWHAT UNCLEAR FOR FRIDAY MORNING. SOME
GUIDANCE SHOWS LINGERING CONVECTION ACROSS THE EASTERN OZARKS AND
SOUTHERN ILLINOIS. THIS COULD BE POSSIBLE IF THE AFOREMENTIONED OUTFLOW
BOUNDARY FROM THURSDAY NIGHT`S CONVECTION IS STILL IN PLACE OVER
THOSE AREAS. HOWEVER...MOST OF THE GUIDANCE SHOWS A DRYING TREND
BY AROUND 12Z ACROSS THE AREA. THEN...THE LOW LEVEL JET REFOCUSES
BACK OVER NORTHERN/NORTHWESTERN MISSOURI. ALL GUIDANCE SHOWS A
TREMENDOUS AMOUNT OF MOISTURE CONVERGENCE IN THAT AREA STARTING
ABOUT 12Z AND RAIN DEVELOPING BETWEEN 12Z AND 15Z...SPREADING INTO
NORTHEAST MISSOURI/WEST CENTRAL ILLINOIS PROBABLY DURING THE MID
TO LATE MORNING. INSTABILITY WILL BUILD RAPIDLY DURING THE LATE
MORNING WITH MUCAPE EXCEEDING 2500 J/KG ACCORDING TO MOST GUIDANCE
AND DEEP LAYER SHEAR AROUND 50-60KTS SO SEVERE STORMS WILL BE
POSSIBLE AT ANY TIME DURING THE LATE MORNING. HOWEVER...THE MAIN
SHOW WILL LIKELY DEVELOP DURING THE LATE AFTERNOON OR EARLY
EVENING AS ANOTHER LOBE OF VORTICITY WRAPS AROUND THE SOUTH SIDE
OF THE UPPER LEVEL LOW AND PUSHES THE SURFACE FRONT INTO NORTHWEST
MISSOURI. WHATEVER`S LEFT OF THE CAP WILL ALSO BE WIPED AWAY.
AFTERNOON CAPE VALUES LOOK TO BE IN EXCESS OF 3000 J/KG WITH SHEAR
STAYING ABOVE 50KTS. THINK THERE WILL BE SOME DISCRETE STORMS
INITIALLY...BUT WITH LITTLE OR NO CAP AND COPIOUS CAPE WE SHOULD
SEE THE STORMS CONGEAL INTO A LINE. CANNOT RULE OUT ANY KIND OF
SEVERE WEATHER INCLUDING DAMAGING WINDS...LARGE HAIL...AND EVEN
TORNADOES WITH THE LINE. THE LINE SHOULD PROGRESS AT A MODERATE
PACE INTO SOUTHEAST MISSOURI BY EARLY MORNING SATURDAY. OF COURSE
WITH THE HEAVY RAIN POTENTIAL AND NEARLY SATURATED GROUND THERE
WILL BE A CONTINUING FLASH FLOOD THREAT...AND IT`S LIKELY THE
FLASH FLOOD WATCH WILL NEED TO BE EXPANDED EITHER EARLY FRIDAY
MORNING OR FRIDAY AFTERNOON TO COVER THE REST OF THE CWFA.
CURRENT THINKING IS THAT THE INITIAL LINE OF CONVECTION WILL WEAKEN
OVER THE EASTERN OZARKS SATURDAY MORNING. HOWEVER THERE WILL BE
REDEVELOPMENT BY EARLY SATURDAY AFTERNOON...PERHAPS AS FAR NORTHWEST
AS THE COLUMBIA AREA...AS THE SURFACE COLD FRONT FINALLY KICKS INTO
GEAR AND HEADS EAST. SPC STILL HAS THE SOUTHEASTERN 2/3 OF THE CWFA
IN A SLIGHT RISK SATURDAY...INCLUDING THE STL METRO AREA AND POINTS
ALONG AND EAST OF THE I-44/I-55 CORRIDORS. THE UPPER LEVEL
SHORTWAVE FINALLY SWINGS THROUGH SATURDAY AFTERNOON/EARLY EVENING
PUSHING THE COLD FRONT SOUTHEAST INTO THE LOWER
MISSISSIPPI/TENNESSEE VALLEYS.
(SUNDAY THROUGH NEXT THURSDAY)
HIGH PRESSURE IS STILL EXPECTED TO BUILD ACROSS THE MIDWEST SUNDAY
AND CONTROL THE WEATHER AT LEAST THROUGH MONDAY. EXPECTING BELOW
NORMAL TEMPERATURES AND LESS HUMID CONDITIONS THROUGH THAT PERIOD.
MEDIUM RANGE GUIDANCE IS A LITTLE FASTER THAN YESTERDAY IN PUSHING
THE HIGH EAST AWAY FROM THE MID-MISSISSIPPI VALLEY. SOUTHERLY FLOW
RETURNS TUESDAY AND BOTH THE GFS AND ECMWF PRINT OUT PRECIP LATE
TUESDAY THROUGH THURSDAY AS A SHORTWAVE DIPS INTO THE NORTHERN
PLAINS. THE GFS IS MUCH MORE DYNAMIC WITH THIS WAVE THAN THE ECMWF
AND THEREFORE CRANKS OUT A LOT MORE PRECIP. HAVE OPTED TO JUST
STICK WITH CHANCE POPS FOR THIS PERIOD RIGHT NOW. WILL CONTINUE TO
WATCH THIS NEXT WAVE AND INCREASE POPS AS NEEDED IF BOTH MODELS
CONTINUE TO TREND WETTER.
CARNEY
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1157 PM CDT THU MAY 30 2013
LO STRATUS TRYING TO FORM IN VERY MOIST LO LEVEL ENVIRONMENT AND
IT IS LOOKING INCREASINGLY LIKELY IT WILL SUCCEED. INITIAL BATCHES
ARE OUT IN CNTRL MO BUT SHOULD EXPAND WITH TIME TO ENCOMPASS ALL
THE TAF SITES BY DAYBREAK. HAVE ADDED LO-END MVFR OR IFR CIGS TO
ALL TAFS. AFTER THAT...SHOULD SEE CONDITIONS IMPROVE SOME HEADING
INTO LATE FRIDAY MORNING AS STRATUS GIVES WAY TO DIURNAL CU
FIELD...AND LIKE THURSDAY...SHOULD GO BKN PRETTY QUICK AND
INITIALLY BE MVFR CATEGORY. FURTHER IMPROVMENT TO VFR DURING
AFTERNOON SEEMS LIKELY. PCPN TRENDS...LATEST BATCH OF RAIN EXITING
STL METRO NOW AND WILL COMPLETELY EXIT BY 07Z...WITH ANOTHER TSRA
COMPLEX TRYING TO FORM OVER ERN KS AND FAR WRN MO. SHOULD SEE THIS
MATURE LATE TONIGHT AND BEGIN MAKING AN APPROACH TO KCOU AROUND
DAYBREAK AND KUIN DURING MID-MORNING. EVENTUALLY...THIS SHOULD
EXPAND AS IT ENTERS A DE-STABILIZING ATMOSPHERE AHEAD OF IT AND
MUCH LIKE THURSDAY...THE MAIN BODY OF IT PUSH INTO STL METRO
DURING FRIDAY EVENING. THIS SHOULD LINGER TO SOME EXTENT WELL INTO
THE NIGHT FOR ALL THE TAF SITES...ALTHOUGH THE WORST SHOULD HAVE
PUSHED TO THE SE BY LATE FRIDAY NIGHT.
SPECIFICS FOR KSTL...LO STRATUS LOOKS INCREASINGLY LIKELY BY
DAYBREAK...BUT SHOULD GIVE WAY TO DIURNAL CU AT SOMEWHAT HIGHER
BASES LATE FRIDAY MORNING...NEXT ROUND OF RAIN SHOULD HOLD OFF
AGAIN UNTIL FRIDAY EVENING ALTHOUGH CAN/T FULLY RULE OUT AN ISOLD
OCCURRENCE AHEAD OF IT IN THE MOIST AND UNSTABLE AIRMASS.
TES
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR AUDRAIN MO-BOONE
MO-CALLAWAY MO-COLE MO-CRAWFORD MO-FRANKLIN MO-GASCONADE MO-
IRON MO-JEFFERSON MO-KNOX MO-LEWIS MO-LINCOLN MO-MADISON MO-
MARION MO-MONITEAU MO-MONROE MO-MONTGOMERY MO-OSAGE MO-PIKE
MO-RALLS MO-REYNOLDS MO-SHELBY MO-ST. CHARLES MO-ST.
FRANCOIS MO-ST. LOUIS CITY MO-ST. LOUIS MO-STE. GENEVIEVE
MO-WARREN MO-WASHINGTON MO.
IL...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR ADAMS IL-BOND IL-
BROWN IL-CALHOUN IL-CLINTON IL-FAYETTE IL-GREENE IL-JERSEY
IL-MACOUPIN IL-MADISON IL-MARION IL-MONROE IL-MONTGOMERY IL-
PIKE IL-RANDOLPH IL-ST. CLAIR IL-WASHINGTON IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1141 PM CDT THU MAY 30 2013
.AVIATION...06Z TAFS FOR KOFK...KLNK AND KOMA.
GENERALLY VFR CONDITIONS ARE EXPECTED THROUGH FRIDAY EVENING. A
LOW PRESSURE SYSTEM OVER THE NORTHERN PLAINS WILL BRING STRONG
SOUTHWEST TO WEST WINDS ACROSS EASTERN NEBRASKA TAF SITES FRIDAY
AFTERNOON. EXPECT WINDS OF 15 TO 30KT WITH SCATTERED TO BROKEN
CLOUDS AT FL040. THERE IS A SMALL CHANCE FOR SHOWERS BEFORE
BETWEEN 10Z AND 14Z...THEN ISOLATED THUNDERSTORMS BETWEEN 21Z AND
00Z. DID NOT INCLUDE THESE IN THE TAF AS COVERAGE IS EXPECTED TO
BE ISOLATED.
DERGAN
&&
.PREV DISCUSSION... /ISSUED 1004 PM CDT THU MAY 30 2013/
UPDATE...
CONVECTION IS FINALLY WINDING DOWN ACROSS EASTERN NEBRASKA AND
SOUTHWEST IOWA...WITH A FEW SHOWERS AND ISOLATED LIGHTNING STRIKES
OCCURRING IN PARTS OF NORTHEAST NEBRASKA AND IN AREAS EAST AND
NORTHEAST OF THE COUNCIL BLUFFS METRO AREA. EXPECT IOWA ACTIVITY
TO MOVE EAST OF OUR AREA WELL BEFORE MIDNIGHT...AND NORTHEAST
NEBRASKA ACTIVITY TO PERSIST FOR A COUPLE OF HOURS. AFTER
MIDNIGHT...SHORT RANGE HRRR AND RAP MODELS ARE BOTH SUGGESTING
SOME SHOWER DEVELOPMENT IN WESTERN NEBRASKA WILL SWING EAST
THROUGH EASTERN NEBRASKA AND SOUTHWEST IOWA. SOME INDICATION OF
THIS ACTIVITY FORMING NOW IN SOUTHWEST NEBRASKA...SO HAVE NO
REASON TO REMOVE THE CHANCE FOR MORE SHOWERS LATER TONIGHT AS PER
GOING FORECAST.
DERGAN
PREV DISCUSSION... /ISSUED 302 PM CDT THU MAY 30 2013/
DISCUSSION...
MAIN CONVECTIVE ACTIVITY HAS SHIFTED EAST OF THE AREA THIS
AFTERNOON WITH CLOSED UPPER LOW LOCATED OVER WESTERN SOUTH DAKOTA
AND SURFACE TROUGH JUST NOSING INTO EASTERN NEBRASKA.
ALTHOUGH THE CHANCE OF THUNDERSTORMS WILL REMAIN ACROSS THE AREA
TONIGHT AND FRIDAY...GENERAL TREND WILL BE TOWARD MORE STABLE
CONDITIONS BY LATE SATURDAY AND THROUGH THE REMAINDER OF THE
WEEKEND AS THE UPPER SYSTEM TRACKS TOWARD THE GREAT LAKES REGION
AND HIGH PRESSURE BUILDS INTO THE CENTRAL PLAINS. TEMPERATURES
WILL BE TURNING COOLER FOR THE WEEKEND AS A COLD FRONT MOVES
THROUGH THE REGION WITH CLOUDS AND SHOWERS ASSOCIATED WITH THE
UPPER LOW LIKELY TO KEEP HIGHS ONLY IN THE 60S FOR SATURDAY.
BREEZY CONDITIONS ALSO EXPECTED ON SATURDAY BEHIND THE FRONT AS
THE COOLER AIR MOVES INTO THE REGION. WARMER AIR RETURNS FOR
SUNDAY SURFACE HIGH SHIFTS EAST WITH CONSIDERABLE SUNSHINE
EXPECTED.
EXTENDED PERIOD LOOKS LIKE IT COULD TURN WET AGAIN AS THE
UPPER LEVEL PATTERN TAKES ON SIMILAR CHARACTERISTICS OF
THIS PAST WEEKS SYSTEM. ANOTHER CLOSED LOW MOVES INTO THE
NORTHERN ROCKIES BY MONDAY THEN TRACKS EAST ACROSS THE NORTHERN
PLAINS AND INTO THE UPPER MIDWEST BY THURSDAY. MODELS HOWEVER
DIFFER ON STRENGTH AND TIMING OF SHORT WAVES SO LIMITED CONFIDENCE
IN EITHER SOLUTION AT THIS TIME.
FOBERT
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS SAN ANGELO TX
754 PM CDT THU MAY 30 2013
.DISCUSSION...
THUNDERSTORMS ARE WELL EAST OF THE AREA WITH LITTLE CHANCE FOR
REDEVELOPMENT BEFORE 10 PM TONIGHT...SO WE WILL GO AHEAD AND
CANCEL THE WATCH AT THIS TIME. WILL GO AHEAD AND REMOVE THE
MENTION OF WEATHER FOR THE REST OF THE OVERNIGHT PERIOD AS WELL.
NO OTHER CHANGES NEEDED AT THIS TIME. 20
&&
.PREV DISCUSSION... /ISSUED 721 PM CDT THU MAY 30 2013/
DISCUSSION...
SEE 00Z AVIATION DISCUSSION BELOW.
AVIATION...
NO SIGNIFICANT CHANGES NEEDED TO THE PREVIOUS TAF FORECASTS. MODEL
SOUNDINGS INDICATE LOW CLOUDS MOVING BACK INTO THE AREA BETWEEN
06Z AND 09Z FOR MOST SITES...WITH KABI POSSIBLY LATER AROUND 12Z.
GUSTY SOUTH/SOUTHWEST WINDS THIS EVENING WILL TURN TO THE
SOUTHEAST OVERNIGHT...BECOMING GUSTY AT A FEW LOCATIONS AFTER 06Z.
MVFR CIGS SHOULD MIX OUT OF THE AREA BY LATE MORNING...BEFORE 18Z.
20
PREV DISCUSSION... /ISSUED 340 PM CDT THU MAY 30 2013/
TONIGHT AND FRIDAY...
A CONDITIONAL CHANCE OF THUNDERSTORMS THIS AFTERNOON AND
EVENING... BASED ON WHERE THE CAP WILL HOLD. WHILE THE CAP WILL
LIKELY HOLD...IF IT DOES BREAK...WITH RAP SB CAPES OF 4000
J/KG...STORMS COULD RAPIDLY BECOME SEVERE. 0-6 KM SHEARS WERE 40
KTS IN THE BIG COUNTRY WITH HIGHER VALUES FARTHER NORTH. A TORNADO
WATCH IS IN EFFECT FOR NORTHERN SECTIONS OF THE THE BIG COUNTRY
THROUGH 10 PM CDT...WHERE AN ENHANCED CUMULUS FIELD WAS INDICATED.
DRYLINE OTHERWISE EXTENDED ALONG THE WESTERN EDGE OF THE SAN ANGELO
CWA THIS AFTERNOON...FROM IRAAN TO SWEETWATER TO NEAR ASPERMONT. BEST CHANCE
OF A STORM WILL BE IN LOW LEVEL CONVERGENCE ALONG THE FRONT...AND
MAINLY NORTH OF THE I-20 CORRIDOR. GENERAL MOVEMENT OF STORMS WILL
BE EAST ...WITH SEVERE OR STORM STORMS PROPAGATING SOUTHEAST.
OTHERWISE ANTHER WARM NIGHT WITH CONTINUED MOISTURE TRANSPORT FROM THE
GULF. OVERNIGHT LOWS WILL BE IN THE LOWER 70S. A DRYLINE WILL BE
MOVING A LITTLE FARTHER EAST FRIDAY AFTERNOON....ALONG A SONORA...SAN
ANGELO... ABILENE...HASKELL LINE. WITH GFS 850 MB TEMPERATURES
INCREASING TO 30 C WEST OF THE DRYLINE...SHOULD SEE SURFACE
TEMPERATURES AT OR SLIGHTLY ABOVE 100 DEGREES F WEST OF THE
DRYLINE... WITH 90S TO THE EAST.
FIRE WEATHER CONDITIONS WILL BE ELEVATED WEST THE DRYLINE THIS
AFTERNOON. WINDS HOWEVER WILL WEAKEN SLIGHTLY THIS EVENING...THEN
BECOME MORE GUSTY BY MIDNIGHT...AS 45-50 KT 850 MB LLJ DEVELOPS.
GUSTY MORNING SOUTH TO SOUTHWEST WINDS WEAKEN ENOUGH BY FRIDAY
AFTERNOON TO KEEP CONDITIONS FROM BECOMING CRITICAL FOR FIRE WEATHER.
SATURDAY THROUGH SUNDAY...
NEXT BEST CHANCE OF RAIN FOR WEST CENTRAL TEXAS WILL COME FOR THE
WEEKEND...AS A COLD FRONT MOVES INTO THE AREA. MODELS HAVE BEEN
FAIRLY CONSISTENT WITH THE TIMING OF THE FRONT...MOVING TO NEAR
THE NORTHWEST BORDER OF THE AREA BY SATURDAY MORNING...AND THEN
SLOWLY SLIDING IT DEEPER INTO WEST CENTRAL TEXAS DURING THE DAY.
AT LEAST SCATTERED SHOWERS AND STORMS SHOULD BREAK OUT ALONG AND
NORTH OF THE BOUNDARY SATURDAY AFTERNOON...AND CONTINUE THROUGH
THE OVERNIGHT HOURS. HAVE INCREASED RAIN CHANCES ACROSS MUCH OF
THE AREA JUST A LITTLE.
WHATS LEFT OF THE BOUNDARY SHOULD BE DISSIPATING ACROSS THE AREA
DURING THE DAY ON SUNDAY. WITH NOT MUCH OF THE BOUNDARY
LEFT...DONT EXPECT STORMS TO BE QUITE AS WIDESPREAD. WILL CONTINUE
THE SLIGHT CHANCE POPS OVER MUCH OF THE AREA.
SUNDAY THROUGH THURSDAY...
DRY CONDITIONS FOR THE PERIOD FOR NOW. MID AND UPPER LEVEL RIDGE
BUILDS INTO THE SOUTHERN ROCKIES...PLACING WEST CENTRAL TEXAS IN
WEAK NORTHWEST FLOW ALOFT. APPEARS WE MAY BE A LITTLE TOO CLOSE TO
THE RIDGE CENTER TO TAKE ADVANTAGE OF THE NORMALLY WETTER SUMMER
NORTHWEST GLOW PATTERN INTO WEDNESDAY. MODELS HAVE SOME
DIFFERENCES BY THE TIME WE GET INTO THURSDAY...WITH THE GFS
SUPPRESSING THE RIDGE ENOUGH TO ALLOW ANOTHER FRONT INTO THE
AREA...WHILE THE ECMWF TRIES TO CLOSE OFF AN UPPER LOW OVER
SOUTHERN CALIFORNIA. AT THIS POINT...WILL JUST LEAVE DRY FOR NOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 72 99 74 92 65 / 10 10 10 20 30
SAN ANGELO 73 99 74 96 67 / 10 10 5 20 30
JUNCTION 72 94 73 94 71 / 10 5 5 10 30
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS SAN ANGELO TX
721 PM CDT THU MAY 30 2013
.DISCUSSION...
SEE 00Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...
NO SIGNIFICANT CHANGES NEEDED TO THE PREVIOUS TAF FORECASTS. MODEL
SOUNDINGS INDICATE LOW CLOUDS MOVING BACK INTO THE AREA BETWEEN
06Z AND 09Z FOR MOST SITES...WITH KABI POSSIBLY LATER AROUND 12Z.
GUSTY SOUTH/SOUTHWEST WINDS THIS EVENING WILL TURN TO THE
SOUTHEAST OVERNIGHT...BECOMING GUSTY AT A FEW LOCATIONS AFTER 06Z.
MVFR CIGS SHOULD MIX OUT OF THE AREA BY LATE MORNING...BEFORE 18Z.
20
&&
.PREV DISCUSSION... /ISSUED 340 PM CDT THU MAY 30 2013/
TONIGHT AND FRIDAY...
A CONDITIONAL CHANCE OF THUNDERSTORMS THIS AFTERNOON AND
EVENING... BASED ON WHERE THE CAP WILL HOLD. WHILE THE CAP WILL
LIKELY HOLD...IF IT DOES BREAK...WITH RAP SB CAPES OF 4000
J/KG...STORMS COULD RAPIDLY BECOME SEVERE. 0-6 KM SHEARS WERE 40
KTS IN THE BIG COUNTRY WITH HIGHER VALUES FARTHER NORTH. A TORNADO
WATCH IS IN EFFECT FOR NORTHERN SECTIONS OF THE THE BIG COUNTRY
THROUGH 10 PM CDT...WHERE AN ENHANCED CUMULUS FIELD WAS INDICATED.
DRYLINE OTHERWISE EXTENDED ALONG THE WESTERN EDGE OF THE SAN ANGELO
CWA THIS AFTERNOON...FROM IRAAN TO SWEETWATER TO NEAR ASPERMONT. BEST CHANCE
OF A STORM WILL BE IN LOW LEVEL CONVERGENCE ALONG THE FRONT...AND
MAINLY NORTH OF THE I-20 CORRIDOR. GENERAL MOVEMENT OF STORMS WILL
BE EAST ...WITH SEVERE OR STORM STORMS PROPAGATING SOUTHEAST.
OTHERWISE ANTHER WARM NIGHT WITH CONTINUED MOISTURE TRANSPORT FROM THE
GULF. OVERNIGHT LOWS WILL BE IN THE LOWER 70S. A DRYLINE WILL BE
MOVING A LITTLE FARTHER EAST FRIDAY AFTERNOON....ALONG A SONORA...SAN
ANGELO... ABILENE...HASKELL LINE. WITH GFS 850 MB TEMPERATURES
INCREASING TO 30 C WEST OF THE DRYLINE...SHOULD SEE SURFACE
TEMPERATURES AT OR SLIGHTLY ABOVE 100 DEGREES F WEST OF THE
DRYLINE... WITH 90S TO THE EAST.
FIRE WEATHER CONDITIONS WILL BE ELEVATED WEST THE DRYLINE THIS
AFTERNOON. WINDS HOWEVER WILL WEAKEN SLIGHTLY THIS EVENING...THEN
BECOME MORE GUSTY BY MIDNIGHT...AS 45-50 KT 850 MB LLJ DEVELOPS.
GUSTY MORNING SOUTH TO SOUTHWEST WINDS WEAKEN ENOUGH BY FRIDAY
AFTERNOON TO KEEP CONDITIONS FROM BECOMING CRITICAL FOR FIRE WEATHER.
SATURDAY THROUGH SUNDAY...
NEXT BEST CHANCE OF RAIN FOR WEST CENTRAL TEXAS WILL COME FOR THE
WEEKEND...AS A COLD FRONT MOVES INTO THE AREA. MODELS HAVE BEEN
FAIRLY CONSISTENT WITH THE TIMING OF THE FRONT...MOVING TO NEAR
THE NORTHWEST BORDER OF THE AREA BY SATURDAY MORNING...AND THEN
SLOWLY SLIDING IT DEEPER INTO WEST CENTRAL TEXAS DURING THE DAY.
AT LEAST SCATTERED SHOWERS AND STORMS SHOULD BREAK OUT ALONG AND
NORTH OF THE BOUNDARY SATURDAY AFTERNOON...AND CONTINUE THROUGH
THE OVERNIGHT HOURS. HAVE INCREASED RAIN CHANCES ACROSS MUCH OF
THE AREA JUST A LITTLE.
WHATS LEFT OF THE BOUNDARY SHOULD BE DISSIPATING ACROSS THE AREA
DURING THE DAY ON SUNDAY. WITH NOT MUCH OF THE BOUNDARY
LEFT...DONT EXPECT STORMS TO BE QUITE AS WIDESPREAD. WILL CONTINUE
THE SLIGHT CHANCE POPS OVER MUCH OF THE AREA.
SUNDAY THROUGH THURSDAY...
DRY CONDITIONS FOR THE PERIOD FOR NOW. MID AND UPPER LEVEL RIDGE
BUILDS INTO THE SOUTHERN ROCKIES...PLACING WEST CENTRAL TEXAS IN
WEAK NORTHWEST FLOW ALOFT. APPEARS WE MAY BE A LITTLE TOO CLOSE TO
THE RIDGE CENTER TO TAKE ADVANTAGE OF THE NORMALLY WETTER SUMMER
NORTHWEST GLOW PATTERN INTO WEDNESDAY. MODELS HAVE SOME
DIFFERENCES BY THE TIME WE GET INTO THURSDAY...WITH THE GFS
SUPPRESSING THE RIDGE ENOUGH TO ALLOW ANOTHER FRONT INTO THE
AREA...WHILE THE ECMWF TRIES TO CLOSE OFF AN UPPER LOW OVER
SOUTHERN CALIFORNIA. AT THIS POINT...WILL JUST LEAVE DRY FOR NOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 72 99 74 92 65 / 10 10 10 20 30
SAN ANGELO 73 99 74 96 67 / 10 10 5 20 30
JUNCTION 72 94 73 94 71 / 10 5 5 10 30
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
329 AM CDT FRI MAY 31 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 329 AM CDT FRI MAY 31 2013
TWO AREAS OF CONVECTION THIS MORNING THAT MAY IMPACT THE AREA. THE
FIRST IS PRIMARILY ALREADY OFF THE NORTHWEST OF THE AREA FROM
NORTHWEST MINNESOTA INTO WESTERN WISCONSIN. THIS AREA IS MOVING
OFF TO THE NORTH/NORTHEAST AND IS NOT EXPECTED TO IMPACT THE
FORECAST AREA. THE OTHER AREA OF CONVECTION IS OVER NORTHWEST
MISSOURI AND IS MOVING TO THE NORTHEAST. THE HRRR SEEMS TO BE
HANDLING THIS THE BEST...BUT IS CONSIDERABLY TOO SLOW WITH IT. THE
TREND FROM THE 31.04Z AND 31.05Z RUNS IS FOR THIS AREA TO MOVE
NORTHEAST ACROSS EASTERN IOWA INTO NORTHERN ILLINOIS AND FOR THE
MOST PART MISSING THE AREA TO THE SOUTH. THE 31.00Z ECMWF ALSO
SHOWS THIS AREA COMING OUT OF MISSOURI BUT TAKES IT FARTHER TO THE
NORTHWEST IMPACTING THE SOUTHERN AND EASTERN AREAS FROM LATE
MORNING THROUGH THE AFTERNOON. THE PREVIOUS FORECAST WAS TRENDED
TOWARD THE POSSIBILITY OF THIS CONVECTION COMING INTO THE AREA SO
HAVE MAINTAINED THESE TRENDS BUT LIMITED THE HIGHER RAIN CHANCES
TO THE SOUTHEAST SECTIONS OF THE FORECAST AREA. BY LATE IN THE
AFTERNOON AND INTO THE EVENING...ALL THE MODELS ARE SHOWING WHAT
LOOKS LIKE A DRY LINE/WIND SHIFT DEVELOPING AHEAD OF THE SURFACE
LOW AND MOVING EAST TOWARD THE AREA. THERE SHOULD BE ANOTHER SHORT
WAVE TROUGH ROUNDING THE UPPER LEVEL LOW TO PROVIDE DYNAMIC LIFT
OVER THIS DRY LINE/WIND SHIFT. BOTH THE 31.00Z NAM AND GFS SHOW A
JET CORE ALSO COMING AROUND THE UPPER LEVEL LOW WITH THE LEFT EXIT
REGION COMING OVER THE AREA TO ADD SOME AGEOSTROPHIC MOTIONS TO THE
FORCING FROM THE SHORT WAVE TROUGH. THIS SHOULD BE ENOUGH FORCING
TO CAUSE A LINE OF CONVECTION TO DEVELOP ALONG THIS DRY LINE AND
THEN WORK RAPIDLY EAST ACROSS THE AREA DURING THE EVENING. SOME
POTENTIAL FOR SEVERE TODAY...BUT THIS IS DEFINITELY NOT AS HIGH AS
THE PAST COUPLE OF DAYS. ML CAPES OF 1000 TO POSSIBLY AS MUCH AS
2000 J/KG SHOULD DEVELOP TODAY AHEAD OF THE DRY LINE. THE BEST
0-6KM SHEAR WILL BE WELL OUT AHEAD OF THE DRY LINE AND WILL LINE
UP BETTER WITH THE EXPECTED CONVECTION TO COME NORTHEAST OUT OF
MISSOURI. HOWEVER...THE 0-3 KM SHEAR SHOULD BE AROUND 30 KNOTS
AHEAD OF THE DRY LINE SO THE POTENTIAL FOR STORMS THIS AFTERNOON
AND EVENING TO PRODUCE DAMAGING WINDS AND HAIL. ALL THE ACTIVITY
SHOULD QUICKLY DIE DOWN AFTER MIDNIGHT AS IT MOVES OFF TO THE EAST
OF THE AREA. BOTH THE NAM AND GFS SHOW THE PRECIPITABLE WATERS
LOWERING DURING THE DAY AS DRIER AIR WRAPS IN FROM THE WEST. WHILE
ANY THUNDERSTORMS MAY PRODUCE SOME LOCALLY HEAVY RAIN...FEEL THAT
THE POTENTIAL FOR WIDESPREAD HEAVY RAINS TO PRODUCE FLASH FLOODING
IS NOT THERE TO SUPPORT THE NEED FOR ANOTHER FLASH FLOOD WATCH.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 329 AM CDT FRI MAY 31 2013
AT LONG LAST...THIS STUBBORN SYSTEM WILL BEGIN TO MAKE A MOVE TO
THE EAST SATURDAY. AS IT DOES...THE SURFACE LOW WILL MOVE FROM
CENTRAL MINNESOTA INTO NORTHERN WISCONSIN AS THE UPPER LEVEL LOW
BECOMES AN OPEN WAVE. THE LAST SHORT WAVE TROUGH WITH THIS SYSTEM
IS EXPECTED TO BE MOVING ACROSS THE AREA AND BE PRODUCING AROUND 8
PVU/S OF VORTICITY ADVECTION IN THE 500-300 MB LAYER. THIS FORCING
FROM THE WAVE COMBINED WITH BEING IN THE DEFORMATION AREA OF THE
SURFACE LOW SHOULD BE ENOUGH TO GENERATE SHOWERS ACROSS MUCH OF
THE AREA. MU CAPES SHOULD BE AROUND 200-300 J/KG IN THE AFTERNOON
WHICH WILL BE GOOD ENOUGH TO PRODUCE SOME ISOLATED THUNDER. THE
REMAINING SHOWERS SHOULD THEN MOVE OFF TO THE EAST SATURDAY NIGHT
WITH SUNDAY BEING THE FIRST DAY IN ABOUT A WEEK WITH NO CHANCE OF
RAIN. MONDAY ALSO LOOKS TO BE DRY WITH HIGH PRESSURE OVER THE AREA
BUT THEN THE RAIN CHANCES START TO RETURN FOR MONDAY NIGHT. THE
31.00Z GFS...GEM AND ECMWF ALL SHOW ANOTHER CLOSED LOW MOVING
TOWARD THE AREA FROM THE PACIFIC NORTHWEST. PLENTY OF DIFFERENCES
THOUGH ON HOW FAST THIS SYSTEM WILL START TO IMPACT THE AREA. THE
OPERATIONAL GFS IS THE FASTEST BRINGING THIS SYSTEM IN...EVEN
FASTER THAN ITS ENSEMBLE MEAN WHILE THE ECMWF IS THE SLOWEST. THIS
LOOKS TO BE ANOTHER SLOW MOVING SYSTEM KEEPING RAIN CHANCES IN THE
FORECAST FOR THE REMAINDER OF THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1201 AM CDT FRI MAY 31 2013
RECENT RAINS ACROSS THE UPPER MISSISSIPPI RIVER VALLEY REGION HAS
RESULTED IN SCT-BKN MVFR STRATUS...AFFECTING MOSTLY ALONG THE
MISSISSIPPI RIVER. HOWEVER...UNCERTAINTY EXISTS ON HOW LONG THE
STRATUS WILL HANG AROUND WITH A BREEZY SOUTHERLY WIND PERSISTING
TO HELP KEEP THINGS MIXED. FOR NOW HAVE INCLUDED A TEMPO GROUP
UNTIL 09Z FOR THE STRATUS...BUT AMENDMENTS MAY BE REQUIRED IF THE
STRATUS HANGS AROUND LONGER. TO THE WEST...A BAND OF SHOWERS AND A
FEW THUNDERSTORMS WAS TRACKING ACROSS SOUTHWEST MN AND NORTHWEST
IA AS OF MIDNIGHT. THESE ARE ON THE WANE...THOUGH...SO UNCERTAIN
DESPITE THERE NORTHEAST MOVEMENT THAT THEY CAN MAKE IT TO KRST
BEFORE DISSIPATING. HAVE LEFT THEM OUT OF THE KRST TAF FOR NOW.
A BRIEF PERIOD OF MVFR CONDITIONS LOOKS POSSIBLE BETWEEN 15-17Z
THIS MORNING...WHEN DAYTIME MIXING TAKES THE RECENT MOISTURE AND
HELPS FORM A LOW CUMULUS DECK. CEILINGS SHOULD RISE TO VFR AS
MIXING CONTINUES. HEADING INTO THE EVENING...INDICATIONS ARE THAT
A DRY-LINE WILL MOVE WEST TO EAST ACROSS THE TAF SITES...BRINGING
WITH IT POTENTIAL FOR A LINE OF SHOWERS AND THUNDERSTORMS. TRIED
TO TIME THIS BETWEEN 23-04Z. THERE COULD BE SEVERE WEATHER WITH
THIS LINE AS WELL...SOMETHING TO WATCH. OTHERWISE...VFR CONDITIONS
LOOK TO FOLLOW IN THE WAKE OF THE DRY-LINE AND EVENTUALLY A COLD
FRONTAL PASSAGE LATER IN THE EVENING.
ONLY OTHER ITEM OF NOTE IS THE WINDS WHICH LOOK TO GET GUSTY THIS
AFTERNOON WITH DAYTIME MIXING AHEAD OF THE DRY-LINE/COLD FRONT.
GUSTS AGAIN OF 20-25 KT FROM THE SOUTH ARE EXPECTED.
&&
.HYDROLOGY...
ISSUED AT 329 AM CDT FRI MAY 31 2013
TURKEY RIVER...
WITH THURSDAY BEING MUCH DRIER THAN EXPECTED IN NORTHEAST IOWA...THE
TURKEY RIVER IS COMING IN MUCH LOWER THAN ORIGINALLY ANTICIPATED.
ELKADER IS EXPECTED TO CREST AROUND 16.5 FEET. THIS IS ABOUT 2 FEET
LOWER THAN THE PREVIOUS FORECAST. THIS IN TURN WILL RESULT IN A MUCH
LOWER CREST FOR GARBER. THE RIVER HAS ALREADY CRESTED AROUND
22.1 FEET. IT SHOULD REMAIN AROUND THIS LEVEL THROUGH MUCH OF TODAY
AND THEN BEGIN A SLOW FALL.
UPPER IOWA...
DORCHESTER HAS FLATTENED OUT AROUND 13.4 FEET. WITH DECORAH
CONTINUING TO RISE UPSTREAM...EXPECT THAT DORCHESTER WILL ONCE AGAIN
START TO RISE THIS MORNING. CONSIDERING THE RAINFALL ACROSS THIS
BASIN ON THURSDAY STILL NOT QUITE SURE WHETHER THE CREST LATER THIS
AFTERNOON WILL BE ABOUT A HALF FEET /15.5 FEET/ HIGHER THAN ITS
PREVIOUS CREST OF 15 FEET ON THURSDAY MORNING. AM MORE INCLINED THAT
IT WILL COME IN WITH A SIMILAR AS THURSDAY MORNING.
KICKAPOO RIVER...
THE UPPER REACHES OF THE KICKAPOO HAVE ALREADY CRESTED AND STARTED
TO FALL RAPIDLY...THEREFORE...LA FARGE WILL BE ADJUSTED TO CREST
LOWER THAN EXPECTED /STILL BELOW FLOOD STAGE/
BLACK RIVER...
BLACK RIVER FALLS IS CONTINUING TO RISE RATHER RAPIDLY THIS MORNING.
LOOKING AT THE WATER UPSTREAM...THE NORTH CENTRAL RIVER FORECAST
CENTER IS EXPECTING IT TO NOW CREST AROUND 49.3 FEET LATER TODAY.
TREMPEALEAU RIVER...
DUE TO THE BROADER EXPANSE NEAR DODGE...EXPECT TO SEE A SLOW AND
STEADY RISE INTO THE WEEKEND. IT STILL LOOKS LIKE IT WILL CREST ON
SUNDAY AROUND 9.6 FEET.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...AJ
HYDROLOGY...BOYNE
AREA FORECAST DISCUSSION
NWS MIAMI FL
1016 AM EDT FRI MAY 31 2013
.UPDATE...
NO CHANGES WERE REQUIRED TO THE CURRENT FORECAST. THE 12Z SOUNDING
INDICATED THAT TROPICAL MOISTURE CONTINUES ACROSS THE REGION WITH
A PWAT JUST OVER TWO INCHES WHICH IS ABOUT 20 PERCENT ABOVE THE NORMAL
PWAT FOR THIS DATE. THE FORECAST FOR THE REST OF TODAY IS IN LINE
WITH THE LATEST MESO-SCALE MODEL GUIDANCE INDICATING THAT THE MOST
ACTIVE PERIOD FOR SHOWERS/THUNDERSTORMS WILL BE THIS AFTERNOON
WITH MOST OF THE COVERAGE EXPECTED ACROSS THE WESTERN PORTIONS OF
THE PENINSULA AFTER 18Z THIS AFTERNOON. THE GUIDANCE ALSO CONTINUES
TO INDICATE THAT THE PRESSURE GRADIENT AND RESULTANT STRONG WINDS
ACROSS THE ATLANTIC WATERS WILL CONTINUE TO SLOWLY DECREASE AS
THE DAY PROGRESSES WITH THE SMALL CRAFT ADVISORY FOR THE ATLANTIC
WATERS AND BISCAYNE BAY EXPIRING AFTER 00Z THIS EVENING...WHICH IS
IN LINE WITH CURRENT OBSERVATION TRENDS.
60
&&
.PREV DISCUSSION... /ISSUED 658 AM EDT FRI MAY 31 2013/
AVIATION...
A BERMUDA CONTINUES TO CONTROL THE WEATHER PATTERN OVER SOUTH
FLORIDA FOR AT LEAST ANOTHER DAY OR TWO. THIS WILL KEEP EAST TO
SOUTHEASTERLY WINDS IN THE FORECAST THROUGH THE TAF PERIOD. IT
WILL ALSO KEEP SHOWERS IN THEM AS WELL. SOME MODELS ARE SUGGESTING
THAT THE PRECIPITATION WILL MOVE OFF TO THE WESTERN SIDE OF THE
STATE, AND BE ENHANCED AS IT REACHES THE GULF COAST. THUS, HAVE
TAKEN MENTION OF RAIN OUT FOR NOW AFTER 19Z, EXCEPT AT KAPF, WHERE
IT IS QUIET NOW AND ADDED RAIN AFTER 18Z. THERE IS ALSO A CHANCE
FOR THUNDERSTORMS THIS AFTERNOON ALONG THE GULF COAST. WITH ANY OF
THE HEAVIER SHOWERS, MVFR AND IFR WILL BE POSSIBLE FOR BRIEF
PERIOD OF TIME.
PREV DISCUSSION... /ISSUED 249 AM EDT FRI MAY 31 2013/
SHORT TERM (TODAY THROUGH SUNDAY)...
MODELS CONTINUE TO HAVE ISSUES WITH THE SURFACE PRESSURE PATTERNS
BUT ARE IN GOOD AGREEMENT WITH THE MID LEVELS. A WEAK PRESSURE
PATTERN ALOFT IS FORECAST TO CONTINUE WITH ABUNDANT DEEP LAYER
MOISTURE IN PLACE WITH PWAT VALUES HOVERING AROUND TWO INCHES. AT
THE SURFACE, THE GFS HAS TRENDED WITH THE ECMWF IN CONTINUING THE
HIGH PRESSURE OVER THE SOUTHEAST STATES BUT SHIFTING IT TO THE
EAST OVER THE WEEKEND AS A WEAK COLD FRONT MOVES INTO THE
SOUTHEAST STATES. THIS WILL RESULT IN RETAINING A STRONG SOUTHEAST
LOW LEVEL FLOW TODAY AND THEN DIMINISHING SATURDAY AND SUNDAY.
THE NAM SEEMS TO BE SUFFERING FROM SOME OF ITS MESOSCALE BIASING
AS IT DEVELOPS A INVERTED TROUGH ALONG THE WEST COAST OF THE
PENINSULA VEERING THE LOW LEVEL FLOW TO THE SOUTH ACROSS OUR
REGION. THE GFS AND ECMWF RETAIN THE THE SOUTHEAST FLOW AND THIS
SEEMS MORE REASONABLE. SO THE HIGH RISK OF RIP CURRENTS WILL
CONTINUE TODAY AND SATURDAY WITH A LESSER THREAT ON SUNDAY BUT
LIKELY MAINTAINING A MODERATE RISK.
THE MAV AND MET GUIDANCE IS NEARLY IN PERFECT AGREEMENT WITH
LIKELY POPS TODAY AND SUNDAY WITH A LESSER CHANCE ON SUNDAY.
HOWEVER, RADAR SIGNATURES ARE NOT TERRIBLY IMPRESSIVE CURRENTLY
AND THE SHORT TERM HIGH RESOLUTION MODELS ARE NOT IN AGREEMENT ON
THE EVOLUTION TOWARDS SUNRISE INTO THE EARLY MORNING. BOTH THE
HRRR AND THE WRF HAVE INITIALIZED WELL IN DEPICTING FAST MOVING
SHOWERS OVER THE ATLANTIC AND MOVING ONSHORE ALONG THE SOUTHEAST
COAST. THE WRF THEN FLARES UP CONVECTION ALONG THE NORTHERN
BROWARD AND PALM BEACH COASTS AROUND 09Z AND DEVELOPS HEAVY
SHOWERS OVER MUCH OF EASTERN PALM BEACH COUNTY. THE HRRR ON THE
OTHER HAND KEEPS THE SHOWERS MINIMAL AND THEN CLEARS OUT THE EAST
COAST DURING THE MORNING WITH ADDITIONAL ACTIVITY DEVELOPING OVER
THE WESTERN HALF IN THE LATE MORNING AS THEY MOVE TOWARDS COASTAL
COLLIER COUNTY. GIVEN THE STATE OF THE CURRENT ATMOSPHERE AND THE
HIGHER RELIABILITY OF THE HRRR, WILL UNDERCUT THE POPS BY AROUND
ONE CATEGORY FROM GUIDANCE.
LONG TERM (SUNDAY NIGHT THROUGH THURSDAY)...
THE GFS AND ECMWF ARE BOTH IN GOOD AGREEMENT IN THE EXTENDED
PERIOD IN MAINTAINING A MOIST AND UNSTABLE ENVIRONMENT OVER SOUTH
FLORIDA WITH WEAK PRESSURE PATTERNS BOTH AT THE SURFACE AND ALOFT.
THIS WILL RESULT IN A MORE TYPICAL SEA BREEZE DRIVEN CONVECTION
PATTERN DURING THE AFTERNOONS AND EVENINGS WITH SLOW STORM MOTION.
AVIATION...
ATLANTIC SHOWERS WILL CONTINUE MOVE ONSHORE THROUGH THE MORNING
ALONG THE EAST COAST AND THEN TRANSITION TOWARDS KAPF DURING THE
AFTERNOON. THERE COULD BE A FEW THUNDERSTORMS ALONG THE WEST COAST
THIS AFTERNOON BUT COVERAGE DOES NOT WARRANT MENTION IN THE TAF AT
THIS TIME. EAST WIND CONTINUES TO BE MODERATE THIS MORNING BUT THE
GRADIENT WILL BEGIN TO RELAX THIS AFTERNOON BUT STILL EXPECTED TO
BE STRONG ENOUGH TO INHIBIT SEA BREEZE DEVELOPMENT ALONG THE
COLLIER COUNTY COAST.
MARINE...
MARINE CONDITIONS WILL CONTINUE TO BE ROUGH ESPECIALLY ALONG THE
ATLANTIC SIDE WITH SCA IN EFFECT. THE SCA WILL BE EXTENDED INTO
THIS AFTERNOON WITH THESE CONDITIONS SLOWLY BEGINNING TO SUBSIDE
OVER THE WEEKEND AS THE HIGH PRESSURE SHIFTS TO THE EAST AND THE
GRADIENT WEAKENS.
FIRE WEATHER...
AMPLE TROPICAL MOISTURE SO NO PROBLEMS OR CONCERNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 83 74 85 73 / 50 30 60 30
FORT LAUDERDALE 87 77 88 75 / 50 40 60 40
MIAMI 86 75 89 76 / 50 40 60 40
NAPLES 86 75 84 75 / 60 30 60 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...RIP CURRENT RISK UNTIL 6 PM EDT THIS EVENING FOR COASTAL BROWARD-
COASTAL MIAMI DADE-COASTAL PALM BEACH.
AM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR BISCAYNE
BAY-COASTAL WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL
OUT 20 NM-COASTAL WATERS FROM JUPITER INLET TO DEERFIELD
BEACH, FL OUT 20 NM-WATERS FROM DEERFIELD BEACH TO OCEAN
REEF, FL EXTENDING FROM 20 NM TO THE TERRITORIAL WATERS OF
THE BAHAMAS-WATERS FROM JUPITER INLET TO DEERFIELD BEACH,
FL EXTENDING FROM 20 NM TO 60 NM.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...60/BD
AVIATION/RADAR...17/ERA
AREA FORECAST DISCUSSION
NWS MIAMI FL
658 AM EDT FRI MAY 31 2013
.AVIATION...
A BERMUDA CONTINUES TO CONTROL THE WEATHER PATTERN OVER SOUTH
FLORIDA FOR AT LEAST ANOTHER DAY OR TWO. THIS WILL KEEP EAST TO
SOUTHEASTERLY WINDS IN THE FORECAST THROUGH THE TAF PERIOD. IT
WILL ALSO KEEP SHOWERS IN THEM AS WELL. SOME MODELS ARE SUGGESTING
THAT THE PRECIPITATION WILL MOVE OFF TO THE WESTERN SIDE OF THE
STATE, AND BE ENHANCED AS IT REACHES THE GULF COAST. THUS, HAVE
TAKEN MENTION OF RAIN OUT FOR NOW AFTER 19Z, EXCEPT AT KAPF, WHERE
IT IS QUIET NOW AND ADDED RAIN AFTER 18Z. THERE IS ALSO A CHANCE
FOR THUNDERSTORMS THIS AFTERNOON ALONG THE GULF COAST. WITH ANY OF
THE HEAVIER SHOWERS, MVFR AND IFR WILL BE POSSIBLE FOR BRIEF
PERIOD OF TIME.
&&
.PREV DISCUSSION... /ISSUED 249 AM EDT FRI MAY 31 2013/
SHORT TERM (TODAY THROUGH SUNDAY)...
MODELS CONTINUE TO HAVE ISSUES WITH THE SURFACE PRESSURE PATTERNS
BUT ARE IN GOOD AGREEMENT WITH THE MID LEVELS. A WEAK PRESSURE
PATTERN ALOFT IS FORECAST TO CONTINUE WITH ABUNDANT DEEP LAYER
MOISTURE IN PLACE WITH PWAT VALUES HOVERING AROUND TWO INCHES. AT
THE SURFACE, THE GFS HAS TRENDED WITH THE ECMWF IN CONTINUING THE
HIGH PRESSURE OVER THE SOUTHEAST STATES BUT SHIFTING IT TO THE
EAST OVER THE WEEKEND AS A WEAK COLD FRONT MOVES INTO THE
SOUTHEAST STATES. THIS WILL RESULT IN RETAINING A STRONG SOUTHEAST
LOW LEVEL FLOW TODAY AND THEN DIMINISHING SATURDAY AND SUNDAY.
THE NAM SEEMS TO BE SUFFERING FROM SOME OF ITS MESOSCALE BIASING
AS IT DEVELOPS A INVERTED TROUGH ALONG THE WEST COAST OF THE
PENINSULA VEERING THE LOW LEVEL FLOW TO THE SOUTH ACROSS OUR
REGION. THE GFS AND ECMWF RETAIN THE THE SOUTHEAST FLOW AND THIS
SEEMS MORE REASONABLE. SO THE HIGH RISK OF RIP CURRENTS WILL
CONTINUE TODAY AND SATURDAY WITH A LESSER THREAT ON SUNDAY BUT
LIKELY MAINTAINING A MODERATE RISK.
THE MAV AND MET GUIDANCE IS NEARLY IN PERFECT AGREEMENT WITH
LIKELY POPS TODAY AND SUNDAY WITH A LESSER CHANCE ON SUNDAY.
HOWEVER, RADAR SIGNATURES ARE NOT TERRIBLY IMPRESSIVE CURRENTLY
AND THE SHORT TERM HIGH RESOLUTION MODELS ARE NOT IN AGREEMENT ON
THE EVOLUTION TOWARDS SUNRISE INTO THE EARLY MORNING. BOTH THE
HRRR AND THE WRF HAVE INITIALIZED WELL IN DEPICTING FAST MOVING
SHOWERS OVER THE ATLANTIC AND MOVING ONSHORE ALONG THE SOUTHEAST
COAST. THE WRF THEN FLARES UP CONVECTION ALONG THE NORTHERN
BROWARD AND PALM BEACH COASTS AROUND 09Z AND DEVELOPS HEAVY
SHOWERS OVER MUCH OF EASTERN PALM BEACH COUNTY. THE HRRR ON THE
OTHER HAND KEEPS THE SHOWERS MINIMAL AND THEN CLEARS OUT THE EAST
COAST DURING THE MORNING WITH ADDITIONAL ACTIVITY DEVELOPING OVER
THE WESTERN HALF IN THE LATE MORNING AS THEY MOVE TOWARDS COASTAL
COLLIER COUNTY. GIVEN THE STATE OF THE CURRENT ATMOSPHERE AND THE
HIGHER RELIABILITY OF THE HRRR, WILL UNDERCUT THE POPS BY AROUND
ONE CATEGORY FROM GUIDANCE.
LONG TERM (SUNDAY NIGHT THROUGH THURSDAY)...
THE GFS AND ECMWF ARE BOTH IN GOOD AGREEMENT IN THE EXTENDED
PERIOD IN MAINTAINING A MOIST AND UNSTABLE ENVIRONMENT OVER SOUTH
FLORIDA WITH WEAK PRESSURE PATTERNS BOTH AT THE SURFACE AND ALOFT.
THIS WILL RESULT IN A MORE TYPICAL SEA BREEZE DRIVEN CONVECTION
PATTERN DURING THE AFTERNOONS AND EVENINGS WITH SLOW STORM MOTION.
AVIATION...
ATLANTIC SHOWERS WILL CONTINUE MOVE ONSHORE THROUGH THE MORNING
ALONG THE EAST COAST AND THEN TRANSITION TOWARDS KAPF DURING THE
AFTERNOON. THERE COULD BE A FEW THUNDERSTORMS ALONG THE WEST COAST
THIS AFTERNOON BUT COVERAGE DOES NOT WARRANT MENTION IN THE TAF AT
THIS TIME. EAST WIND CONTINUES TO BE MODERATE THIS MORNING BUT THE
GRADIENT WILL BEGIN TO RELAX THIS AFTERNOON BUT STILL EXPECTED TO
BE STRONG ENOUGH TO INHIBIT SEA BREEZE DEVELOPMENT ALONG THE
COLLIER COUNTY COAST.
MARINE...
MARINE CONDITIONS WILL CONTINUE TO BE ROUGH ESPECIALLY ALONG THE
ATLANTIC SIDE WITH SCA IN EFFECT. THE SCA WILL BE EXTENDED INTO
THIS AFTERNOON WITH THESE CONDITIONS SLOWLY BEGINNING TO SUBSIDE
OVER THE WEEKEND AS THE HIGH PRESSURE SHIFTS TO THE EAST AND THE
GRADIENT WEAKENS.
FIRE WEATHER...
AMPLE TROPICAL MOISTURE SO NO PROBLEMS OR CONCERNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 83 74 85 73 / 50 30 60 30
FORT LAUDERDALE 87 77 88 75 / 50 40 60 40
MIAMI 86 75 89 76 / 50 40 60 40
NAPLES 86 75 84 75 / 60 30 60 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...RIP CURRENT RISK UNTIL 6 PM EDT THIS EVENING FOR COASTAL BROWARD-
COASTAL MIAMI DADE-COASTAL PALM BEACH.
AM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR BISCAYNE
BAY-COASTAL WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL
OUT 20 NM-COASTAL WATERS FROM JUPITER INLET TO DEERFIELD
BEACH, FL OUT 20 NM-WATERS FROM DEERFIELD BEACH TO OCEAN
REEF, FL EXTENDING FROM 20 NM TO THE TERRITORIAL WATERS OF
THE BAHAMAS-WATERS FROM JUPITER INLET TO DEERFIELD BEACH,
FL EXTENDING FROM 20 NM TO 60 NM.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...30/KOB
AVIATION/RADAR...13/SI
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1048 AM CDT FRI MAY 31 2013
.UPDATE...
ISSUED AT 1036 AM CDT FRI MAY 31 2013
MCS TOOL FROM THE UKMET AND RAP ARE DEPICTING REASONABLY WELL THE
CURRENT WX. THE FIRST MCS IS MOVING ACROSS THE SOUTHERN CWFA
PRODUCING LIGHT TO MODERATE RAIN. SLIGHTLY DRIER AIR MIXING DOWN
ON THE NORTH SIDE IS RESULTING IN A BRIEF PERIOD OF HIGH WINDS.
THE TRENDS WITH THE RAP MODEL INDICATE THE NEW MCS ACROSS NORTHERN
MISSOURI WILL SLOWLY MERGE WITH THE FIRST MCS THROUGH LATE
MORNING. THE SOUTHEAST HALF OF THE CWFA WILL BE AFFECTED BY THE
COMBINED MCS WITH IT EXITING THE CWFA BY EARLY EVENING. THUS THIS
AREA WILL SEE THE MORE WIDESPREAD AND POTENTIALLY HEAVY RAINFALL.
FLOW BASED OFF THE SFC OBS THROUGH 15Z INDICATE THE CLEAR AREAS
ACROSS CENTRAL/NORTHERN IOWA WILL FILL WITH CLOUDS AS THE MORNING
AND AFTERNOON PROGRESS. THE LIFT TOOL SUGGESTS THE POTENTIAL FOR
NEW CONVECTION DEVELOPING AHEAD OF THE APPROACHING FRONT.
AS FOR THE FLASH FLOOD HEADLINES...THEY ARE BEING LEFT IN PLACE
FOR NOW. DEPENDING UPON HOW CONVECTION EVOLVES DURING THE LATE
MORNING AND AFTERNOON...THE POSSIBILITY EXISTS THAT SOME HEADLINES
MAY BE DROPPED. ..08..
UPDATE ISSUED AT 642 AM CDT FRI MAY 31 2013
IMPULSE MOVING AROUND THE BASE OF THE TROUGH WAS PUSHING INTO NW
MO AND WILL BE HEADING NORTHEAST INTO THE DVN CWA LATER THIS
MORNING. RAP MODEL INCREASES THE LOW LEVEL JET SO THUNDERSTORMS
SHOULD CONTINUE TO SPREAD NORTHEAST INTO THE CWA THIS MORNING AND
THEN INCREASE IN COVERAGE/INTENSITY THIS AFTERNOON.
&&
.SYNOPSIS...
ISSUED AT 315 AM CDT FRI MAY 31 2013
ALL IS QUIET FOR NOW ACROSS THE DVN CWA EARLY THIS MORNING BUT
THUNDERSTORMS WERE LINED UP FROM NORTHEAST IL INTO AR MOVING
NORTHEAST. OTHER THUNDERSTORMS WERE FORMING IN EXTREME NW MO AND
NORTHEAST KS. A SUPERCELL WAS PRODUCING LARGE HAIL AROUND TOPEKA
AND THESE STORMS WERE SPREADING EAST/NORTHEAST AT 40 KNOTS. STRONG LOW
PRESSURE WAS SPINNING OVER THE DAKOTAS WITH A COLD FRONT IN THE
PLAINS. CURRENT TEMPERATURES WERE IN THE 60S ACROSS IA...MO...KS
AND IN THE 70S IN THE SOUTHERN PLAINS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 315 AM CDT FRI MAY 31 2013
HEADLINES...WILL CONTINUE THE FLASH FLOOD WATCH TODAY THROUGH
TONIGHT.
FORECAST FOCUS ON ACTIVE SEVERE WEATHER TODAY INTO THIS EVENING
AND POTENTIAL FOR FLASH FLOODING ESPECIALLY WHERE TRAINING STORMS
OCCUR.
TODAY...SHOULD BE JUST ENOUGH SUNSHINE THIS MORNING TO PUSH
TEMPERATURES INTO THE LOWER TO MID 70S THIS MORNING WITH THE
CONVECTIVE TEMPERATURE REACHED. THUNDERSTORM ACTIVITY TO OUR
SOUTHWEST SHOULD QUICKLY PUSH INTO THE DVN CWA THIS MORNING.
AIR MASS WILL BE DESTABILIZING ALLOWING FOR THUNDERSTORMS TO
INTENSIFY. MODERATE TO STRONG DEEP LAYER SHEAR AND DRY AIR ALOFT
AND FREEZING LEVEL AT 11-12K FT SHOULD BE IDEAL FOR LARGE HAIL
LATER THIS MORNING...POTENTIALLY QUARTER TO GOLF BALL SIZE.
THIS AFTERNOON...WINDS ALOFT BECOME MORE UNIDIRECTIONAL WITH MID
LEVEL WINDS INCREASING TO OVER 70 KNOTS. THIS WOULD FAVOR BOWING
SEGMENTS AND DAMAGING WINDS GREATER THAN 70-80 MPH. WITH THE
GROUND SATURATED THIS WOULD EASILY KNOCK OVER LARGE TREES. WITH
SUCH STRONG SHEAR ANY DISCRETE THUNDERSTORM MAY BECOME
SUPERCELLULAR WITH THE POTENTIAL FOR TORNADOES/LARGE HAIL...ALSO
IN ANY LEWP/BOWING SEGMENTS. THUNDERSTORMS WILL BE FAST MOVING BUT
ANY TRAINING OF STORMS WOULD ENHANCE THE FLASH FLOOD THREAT.
OPERATIONAL MODELS SUGGEST THE HIGHEST RAIN TOTALS TO BE ACROSS
ABOUT OUR SOUTHEAST HALF CWA. HIGHS TODAY AROUND 80.
TONIGHT...ACTIVE THUNDERSTORMS THIS EVENING SHOULD BE MAINLY IN
OUR IL COUNTIES WITH ACTIVITY THEN PUSHING EAST OF THE DVN CWA BY
MIDNIGHT. COLD FRONT WILL BE MOVING INTO EASTERN IA LATER TONIGHT
BRINGING COOLER AND DRIER AIR INTO EASTERN IA. MINIMUM TEMPERATURES
WILL RANGE FROM THE UPPER 50S WEST TO MID 60S EAST.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 315 AM CDT FRI MAY 31 2013
SATURDAY...THE SURFACE COLD FRONT IS PROGGED TO BE NEAR THE
MISSISSIPPI RIVER AT 12Z SATURDAY. THE COLD FRONT WILL CONTINUE TO
SLIDE EAST DURING THE DAY AS THE UPPER TROUGH AXIS SHIFTS EAST
ACROSS IOWA. THE CHANCE FOR SOME SHOWERS AND STORMS WILL CONTINUE IN
THE VICINITY OF THE SURFACE FRONT EARLY SATURDAY. WILL HOLD ONTO
SOME SLIGHT TO CHANCE CATEGORY PRECIPITATION PROBABILITIES THROUGH
THE REMAINDER OF SATURDAY AS THE MID LEVEL BOUNDARY AND UPPER TROUGH
ENERGY WORK ACROSS THE FORECAST AREA. HOWEVER ANY SHOWERS OR STORMS
ON SATURDAY WILL BE LACKING IN HEAVY RAIN OR SEVERE POTENTIAL.
TEMPERATURES SATURDAY ARE A BIT OF A CHALLENGE WITH CLOUD COVER AND
COLDER AIR STARTING TO WORK IN BEHIND THE FRONT.
SUNDAY THROUGH MONDAY...A BRIEF RESPITE IN THE ACTIVE WEATHER
PATTERN IS IN STORE FROM SUNDAY INTO MONDAY. COOLER AND DRIER AIR
WILL MOVE IN AS UPPER RIDGING AND SURFACE HIGH PRESSURE SPREAD
ACROSS THE REGION. TEMPERATURES ON SUNDAY LOOK TO BE AROUND 10
DEGREES BELOW NORMAL...WITH MORNING LOWS IN THE LOWER TO MIDDLE 50S
AND HIGHS IN THE MIDDLE TO UPPER 60S. MONDAY MORNING TEMPERATURES
COULD BOTTOM OUT IN THE 40S ACROSS PORTIONS OF THE FORECAST AREA.
TUESDAY THROUGH THURSDAY...YET ANOTHER UPPER LEVEL SYSTEM WILL
APPROACH THE MIDWEST MID TO LATE NEXT WEEK. LEAD SHORTWAVE ENERGY
COULD KICK OFF SOME PRECIPITATION AS EARLY AS TUESDAY...WITH
INCREASING SHOWER AND THUNDERSTORM CHANCES BY WEDNESDAY. A WARMING
TREND WILL BRING TEMPERATURES BACK CLOSER TO NORMAL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 642 AM CDT FRI MAY 31 2013
IFR/MVFR CONDITIONS THIS MORNING WITH ANOTHER LARGE AND VIGOROUS
CONVECTIVE COMPLEX IMPACTING ALL TERMINALS BETWEEN 31/15Z AND
01/03Z WITH PERIODS OF MVF OR EVEN IFR CONDITIONS IN THE HEAVIEST
AND STRONGEST STORMS DUE TO HEAVY RAINS. SOUTH WINDS WILL CONTINUE
OUTSIDE OF ANY STORMS AT 5 TO 10 KTS. STRONGEST STORMS MAY ALSO
PRODUCE WIND GUSTS AOA 40 KTS AND POSSIBLY LARGE HAIL.
&&
.HYDROLOGY...
ISSUED AT 315 AM CDT FRI MAY 31 2013
WITH MANY RIVERS IN MODERATE TO MAJOR FLOOD AND THE GROUND
COMPLETELY SATURATED THE THREAT FOR FLASH FLOODING WILL REMAIN
TODAY INTO THIS EVENING...ESPECIALLY WHERE TRAINING OF STORMS
OCCUR. THE HEAVIEST RAINS SHOULD BE ACROSS THE SOUTHEAST HALF OF
THE DVN CWA WHERE MANY AREAS SHOULD RECEIVE AT LEAST AN INCH OF
RAIN TODAY INTO THIS EVENING. HOWEVER...SEVERAL INCHES OF RAIN
WOULD PRODUCE SEVERE FLASH FLOODING ESPECIALLY IF STORMS CAN TRAIN
ACROSS THE SAME LOCATIONS.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR BENTON-BUCHANAN-
CEDAR-CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-IOWA-
JACKSON-JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-
MUSCATINE-SCOTT-VAN BUREN-WASHINGTON.
IL...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR BUREAU-CARROLL-
HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER-
PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE.
MO...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR CLARK-SCOTLAND.
&&
$$
UPDATE...08
SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...STOFLET
AVIATION...HAASE
HYDROLOGY...HAASE
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
649 AM CDT FRI MAY 31 2013
.UPDATE...
ISSUED AT 642 AM CDT FRI MAY 31 2013
IMPULSE MOVING AROUND THE BASE OF THE TROUGH WAS PUSHING INTO NW
MO AND WILL BE HEADING NORTHEAST INTO THE DVN CWA LATER THIS
MORING. RAP MODEL INCREASES THE LOW LEVEL JET SO THUNDERSTORMS
SHOULD CONTINUE TO SPREAD NORTHEAST INTO THE CWA THIS MORNING AND
THEN INCREASE IN COVERAGE/INTENSITY THIS AFTERNOON.
&&
.SYNOPSIS...
ISSUED AT 315 AM CDT FRI MAY 31 2013
ALL IS QUIET FOR NOW ACROSS THE DVN CWA EARLY THIS MORNING BUT
THUNDERSTORMS WERE LINED UP FROM NORTHEAST IL INTO AR MOVING
NORTHEAST. OTHER THUNDERSTORMS WERE FORMING IN EXTREME NW MO AND
NORTHEAST KS. A SUPERCELL WAS PRODUCING LARGE HAIL AROUND TOPEKA
AND THESE STORMS WERE SPREADING EAST/NORTHEAST AT 40 KNOTS. STRONG LOW
PRESSURE WAS SPINNING OVER THE DAKOTAS WITH A COLD FRONT IN THE
PLAINS. CURRENT TEMPERATURES WERE IN THE 60S ACROSS IA...MO...KS
AND IN THE 70S IN THE SOUTHERN PLAINS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 315 AM CDT FRI MAY 31 2013
HEADLINES...WILL CONTINUE THE FLASH FLOOD WATCH TODAY THROUGH
TONIGHT.
FORECAST FOCUS ON ACTIVE SEVERE WEATHER TODAY INTO THIS EVENING
AND POTENTIAL FOR FLASH FLOODING ESPECIALLY WHERE TRAINING STORMS
OCCUR.
TODAY...SHOULD BE JUST ENOUGH SUNSHINE THIS MORNING TO PUSH
TEMPERATURES INTO THE LOWER TO MID 70S THIS MORNING WITH THE
CONVECTIVE TEMPERATURE REACHED. THUNDERSTORM ACTIVITY TO OUR
SOUTHWEST SHOULD QUICKLY PUSH INTO THE DVN CWA THIS MORNING.
AIR MASS WILL BE DESTABILIZING ALLOWING FOR THUNDERSTORMS TO
INTENSIFY. MODERATE TO STRONG DEEP LAYER SHEAR AND DRY AIR ALOFT
AND FREEZING LEVEL AT 11-12K FT SHOULD BE IDEAL FOR LARGE HAIL
LATER THIS MORNING...POTENTIALLY QUARTER TO GOLF BALL SIZE.
THIS AFTERNOON...WINDS ALOFT BECOME MORE UNIDIRECTIONAL WITH MID
LEVEL WINDS INCREASING TO OVER 70 KNOTS. THIS WOULD FAVOR BOWING
SEGMENTS AND DAMAGING WINDS GREATER THAN 70-80 MPH. WITH THE
GROUND SATURATED THIS WOULD EASILY KNOCK OVER LARGE TREES. WITH
SUCH STRONG SHEAR ANY DISCRETE THUNDERSTORM MAY BECOME
SUPERCELLULAR WITH THE POTENTIAL FOR TORNADOES/LARGE HAIL...ALSO
IN ANY LEWP/BOWING SEGMENTS. THUNDERSTORMS WILL BE FAST MOVING BUT
ANY TRAINING OF STORMS WOULD ENHANCE THE FLASH FLOOD THREAT.
OPERATIONAL MODELS SUGGEST THE HIGHEST RAIN TOTALS TO BE ACROSS
ABOUT OUR SOUTHEAST HALF CWA. HIGHS TODAY AROUND 80.
TONIGHT...ACTIVE THUNDERSTORMS THIS EVENING SHOULD BE MAINLY IN
OUR IL COUNTIES WITH ACTIVITY THEN PUSHING EAST OF THE DVN CWA BY
MIDNIGHT. COLD FRONT WILL BE MOVING INTO EASTERN IA LATER TONIGHT
BRINGING COOLER AND DRIER AIR INTO EASTERN IA. MINIMUM TEMPERATURES
WILL RANGE FROM THE UPPER 50S WEST TO MID 60S EAST.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 315 AM CDT FRI MAY 31 2013
SATURDAY...THE SURFACE COLD FRONT IS PROGGED TO BE NEAR THE
MISSISSIPPI RIVER AT 12Z SATURDAY. THE COLD FRONT WILL CONTINUE TO
SLIDE EAST DURING THE DAY AS THE UPPER TROUGH AXIS SHIFTS EAST
ACROSS IOWA. THE CHANCE FOR SOME SHOWERS AND STORMS WILL CONTINUE IN
THE VICINITY OF THE SURFACE FRONT EARLY SATURDAY. WILL HOLD ONTO
SOME SLIGHT TO CHANCE CATEGORY PRECIPITATION PROBABILITIES THROUGH
THE REMAINDER OF SATURDAY AS THE MID LEVEL BOUNDARY AND UPPER TROUGH
ENERGY WORK ACROSS THE FORECAST AREA. HOWEVER ANY SHOWERS OR STORMS
ON SATURDAY WILL BE LACKING IN HEAVY RAIN OR SEVERE POTENTIAL.
TEMPERATURES SATURDAY ARE A BIT OF A CHALLENGE WITH CLOUD COVER AND
COLDER AIR STARTING TO WORK IN BEHIND THE FRONT.
SUNDAY THROUGH MONDAY...A BRIEF RESPITE IN THE ACTIVE WEATHER
PATTERN IS IN STORE FROM SUNDAY INTO MONDAY. COOLER AND DRIER AIR
WILL MOVE IN AS UPPER RIDGING AND SURFACE HIGH PRESSURE SPREAD
ACROSS THE REGION. TEMPERATURES ON SUNDAY LOOK TO BE AROUND 10
DEGREES BELOW NORMAL...WITH MORNING LOWS IN THE LOWER TO MIDDLE 50S
AND HIGHS IN THE MIDDLE TO UPPER 60S. MONDAY MORNING TEMPERATURES
COULD BOTTOM OUT IN THE 40S ACROSS PORTIONS OF THE FORECAST AREA.
TUESDAY THROUGH THURSDAY...YET ANOTHER UPPER LEVEL SYSTEM WILL
APPROACH THE MIDWEST MID TO LATE NEXT WEEK. LEAD SHORTWAVE ENERGY
COULD KICK OFF SOME PRECIPITATION AS EARLY AS TUESDAY...WITH
INCREASING SHOWER AND THUNDERSTORM CHANCES BY WEDNESDAY. A WARMING
TREND WILL BRING TEMPERATURES BACK CLOSER TO NORMAL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 642 AM CDT FRI MAY 31 2013
IFR/MVFR CONDITIONS THIS MORNING WITH ANOTHER LARGE AND VIGOROUS
CONVECTIVE COMPLEX IMPACTING ALL TERMINALS BETWEEN 31/15Z AND
01/03Z WITH PERIODS OF MVF OR EVEN IFR CONDITIONS IN THE HEAVIEST
AND STRONGEST STORMS DUE TO HEAVY RAINS. SOUTH WINDS WILL CONTINUE
OUTSIDE OF ANY STORMS AT 5 TO 10 KTS. STRONGEST STORMS MAY ALSO
PRODUCE WIND GUSTS AOA 40 KTS AND POSSIBLY LARGE HAIL.
&&
.HYDROLOGY...
ISSUED AT 315 AM CDT FRI MAY 31 2013
WITH MANY RIVERS IN MODERATE TO MAJOR FLOOD AND THE GROUND
COMPLETELY SATURATED THE THREAT FOR FLASH FLOODING WILL REMAIN
TODAY INTO THIS EVENING...ESPECIALLY WHERE TRAINING OF STORMS
OCCUR. THE HEAVIEST RAINS SHOULD BE ACROSS THE SOUTHEAST HALF OF
THE DVN CWA WHERE MANY AREAS SHOULD RECEIVE AT LEAST AN INCH OF
RAIN TODAY INTO THIS EVENING. HOWEVER...SEVERAL INCHES OF RAIN
WOULD PRODUCE SEVERE FLASH FLOODING ESPECIALLY IF STORMS CAN TRAIN
ACROSS THE SAME LOCATIONS.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR BENTON-BUCHANAN-
CEDAR-CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-IOWA-
JACKSON-JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-
MUSCATINE-SCOTT-VAN BUREN-WASHINGTON.
IL...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR BUREAU-CARROLL-
HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER-
PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE.
MO...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR CLARK-SCOTLAND.
&&
$$
UPDATE...HAASE
SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...STOFLET
AVIATION...HAASE
HYDROLOGY...HAASE
AREA FORECAST DISCUSSION
NWS DES MOINES IA
648 AM CDT FRI MAY 31 2013
.SHORT TERM.../TODAY /...
ISSUED AT 323 AM CDT FRI MAY 31 2013
THUNDERSTORMS HAVE DEVELOPED IN NORTHERN MISSOURI ALONG A ZONE OF
WARM AIR ADVECTION AND A LOW LEVEL JET. JUST NORTH OF THAT AREA BUT
STILL IN MO SOME WEAKER STORMS HAVE DEVELOPED AND ARE DISSIPATING.
THE STORMS HAVE AN EAST/NORTHEASTERLY TRACK AND WILL EVENTUALLY CLIP
FAR SOUTHERN IOWA. THE WEAKENING STORMS JUST ACROSS OUR BORDER WILL
LIKELY ONLY PRODUCE SOME SHOWERS ACROSS THE FAR SOUTH IN THE NEXT
FEW HOURS. A VORT MAX AND SHORT WAVE WILL PIVOT AROUND THE UPPER
LOW OVER THE EASTERN DAKOTAS AND THIS WILL SHIFT THE STORMS THAT ARE
A LITTLE FURTHER SOUTH IN NORTHERN MO RIGHT INTO SOUTHERN/SOUTHEAST
IOWA BY MID TO LATE MORNING THEN INTO EASTERN IOWA BY EARLY
AFTERNOON.
BY MID TO LATE AFTERNOON A STRONGER SHORT WAVE WILL PUSH INTO
WESTERN IOWA WHICH WILL BRING MORE THUNDERSTORMS TO THAT AREA AND
THIS WILL SHIFT EAST FROM 21Z INTO THE EVENING HOURS. THERE WILL BE
A TIME IN THE AFTERNOON WHERE SHOWERS AND STORMS WILL STILL BE OVER
EASTERN IOWA AND ADDITIONAL STORMS DEVELOPING OVER THE WEST WITH
CENTRAL IOWA DRY. LAPSE RATES OVER SOUTHERN IOWA AND ABOUT THE
SOUTHEAST THIRD OF THE STATE ARE PRETTY STEEP THIS AFTERNOON AND
THERE IS MORE THAN SUFFICIENT SHEAR FOR A FEW SEVERE STORMS. IN
ADDITION...HEAVY RAINFALL IS LIKELY WITH THE STORMS AS WELL...MAINLY
OVER THE FAR EAST AND SOUTHEAST.
YESTERDAY THE HI RES NMM EAST REALLY HAD THE PRECIP AREAS PEGGED AND
ALSO HAD DECENT TIMING OF THE PRECIP. I STILL LIKE WHAT THIS MODEL
DOES WITH THE PRECIP TODAY HOWEVER IT IS NOT PICKING UP THE MO
CONVECTION VERY WELL AT THIS TIME. IT IS ABOUT 3 HOURS LATER WITH
THAT SO I BLENDED NMM POPS WITH THE HRRR AND NAM12.
AS FOR TEMPS...THERE SHOULD BE SLIGHTLY WARMER AIR OVER THE SOUTH
AND SOUTHEAST TODAY SO I NUDGED HIGHS UP IN THESE AREAS. THE NORTH
SHOULD SEE TEMPS A FEW DEGREES WARMER AS WELL.
.LONG TERM.../TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 323 AM CDT FRI MAY 31 2013
FEWER CONCERNS FOR THE NEXT SEVERAL DAYS AS UPPER TROUGH BEGINS TO
SWING EAST. ALREADY THE MAIN H850 MOISTURE CHANNEL HAS SHIFTED EAST
OF THE AREA WITH THE LINE OF STRONGER THUNDERSTORMS THAT EXITED THE
EASTERN PORTION OF THE FORECAST AREA EARLY THIS EVENING. HOWEVER
THERE WILL STILL BE SOME RESIDUAL CONVECTION FAR SOUTHEAST EARLY IN
THE PERIOD TONIGHT...ENDING QUICKLY AND MOVING EAST BY 06Z.
MEANWHILE...THE MAIN FEATURE YET LATE TONIGHT AND EARLY SATURDAY
WILL BE THE OLD H500 LOW WHICH IS LIKELY TO SPIN UP SOME SHOWERS AND
ISOLATED THUNDER AS IT MOVES ACROSS THE REGION TOMORROW AS THE COLD
POOL UNDERNEATH THE UPPER LEVEL LOW DROPS SOUTHEAST INTO THE REGION.
STEEP LAPSE RATES WILL BE IN THE AREA OF THE LOW ON SATURDAY AND
OVER THE NORTH INTO MN AND WESTERN WI NON SUPERCELL TORNADO PARAMETER
IS INCREASING. SOMETHING TO KEEP AN EYE ON THERE...AN ISOLATED
FUNNEL CLOUD OR LANDSPOUT MAY BE POSSIBLE IF LAPSE RATES BECOME
STEEP ENOUGH IN THE AFTERNOON HOURS. OTHERWISE...THE OLD LOW WILL
PULL EAST SATURDAY NIGHT AND SUNDAY LEAVING THE REGION WITH COOLER
AIR FOR THE FIRST PART OF JUNE. THIS WILL KEEP THE AREA IN THE 60S
FOR HIGHS ON SUNDAY WITH MID 40S NORTH AND LOWER 50S SOUTH FOR LOWS
ON MONDAY MORNING. AS THE HIGH MOVES EAST...HIGHS WILL RESPOND INTO
THE LOWER 70S FOR MONDAY. MONDAY NIGHT WARM AIR ADVECTION AND MID
LEVEL MOISTURE BEGIN TO INCREASE AGAIN...RESULTING IN LATE
NIGHT/EARLY MORNING ELEVATED CONVECTION. TUESDAY LOOKS ACTIVE AS A
STRONGER WAVE ROTATES NORTHEAST INTO THE STATE. THIS WILL RESULT IN
MORE WIDESPREAD THUNDERSTORMS WITH RAINFALL AMOUNTS POSSIBLY
APPROACHING ONE INCH IN SOME PLACES. THIS WILL CERTAINLY KEEP SOIL
MOISTURE HIGH...AND ALSO RESULT IN RENEWED RIVER RISES. THE SYSTEM
WILL GRADUALLY EXIT THE REGION BY THURSDAY. THE LARGER SCALE FLOW
PATTERN REMAINS GENERALLY WESTERLY AT MID TO HIGH LEVELS. THIS
PROMOTES LEE SIDE TROUGHING AND WITH A CONTINUED SUB TROPICAL HIGH
ANCHORED OFF THE EAST COAST A WETTER THAN NORMAL PATTERN IS LIKELY
TO CONTINUE OVER THE NEXT 7 TO 10 DAYS. ANOTHER INTERESTING WRINKLE
IS A TROPICAL DISTURBANCE IN THE GULF OF MEXICO BY NEXT THUR/FRIDAY
WHICH MAY EVENTUALLY BE PULLED NORTH TOWARD THE MID MISSISSIPPI
RIVER VALLEY. HIGH TEMPERATURES OVER THE NEXT WEEK WILL LIKELY
REMAIN IN THE 70S ON AVERAGE AND NOT BREAK OUT OF A 65 TO 75 RANGE
BY TOO MUCH IF ANY. ANOTHER NOTE WITH OUR CURRENT WET WEATHER WILL
BE CLOUD COVER. UNLESS WE HAVE A STRONG HIGH AND STRONG
SUBSIDENCE...MOST LATE MORNINGS AND AFTERNOONS ON ANY SUNNY DAY WILL
GO SCT TO BKN BY AFTERNOON.
&&
.AVIATION...31/12Z
ISSUED AT 648 AM CDT THU MAY 30 2013
THERE WILL BE A COUPLE OF UPPER LEVEL DISTURBANCES AFFECTING TAF
LOCATIONS TODAY. THIS MORNING...MAINLY AFTER 15Z ONE DISTURBANCE
WILL MOVE ACROSS THE AREA MOVING SHOWERS AND THUNDERSTORMS FROM
NORTHERN MO INTO SOUTHEAST IA. THIS SHOULD MAINLY AFFECT KOTM BUT
COULD EXTEND COVERAGE TO KDSM AND KALO AS WELL. THIS AFTERNOON A
STRONGER DISTURBANCE WILL SHIFT ACROSS IOWA BETWEEN 21Z AND 05Z
BRINGING ANOTHER CHANCE FOR THUNDERSTORMS. THESE WOULD BE MORE
LIKELY TO PRODUCE HEAVY RAINFALL AS WELL AS STRONG WIND AND POSSIBLY
HAIL. IFR CONDITIONS ARE EXPECTED THROUGH 15-16Z THEN MVFR
CONDITIONS WITH STORMS OTHERWISE MOST LOCATIONS SHOULD BE VFR. SFC
WIND WILL BE SOUTHERLY AT 15-25KTS.
&&
.HYDROLOGY...
ISSUED AT 323 AM CDT FRI MAY 31 2013
A FLASH FLOOD WATCH REMAINS IN EFFECT FOR BUTLER COUNTY AT THIS
TIME DUE TO THE SMALL BREACH IN THE LEVEE ALONG THE BEAVER CREEK
AT NEW HARTFORD.
A WEATHER DISTURBANCE CAUSING AN AREA OF THUNDERSTORMS FROM KANSAS
AND MISSOURI WILL ROTATE NORTHEAST TODAY...AFFECTING THE SOUTHEAST
HALF OF THE FORECAST AREA LATER THIS MORNING THROUGH THE AFTERNOON
HOURS. THE SOUTHEAST MAY SEE UP TO AN INCH OR MORE OF RAIN...BUT
CURRENT FLASH FLOOD GUIDANCE HAS INCREASED TO 1.3 TO 1.5 INCHES
PER HOUR AND 1.5 TO 2.25 INCHES IN 3 HOURS AT PRESENT. UNLESS THE
STORMS BACK BUILD...THE RISK FOR ANY FLASH FLOODING REMAINS LOW
TODAY ACROSS OUR FORECAST AREA.
RIVER FLOOD WARNINGS REMAIN IN EFFECT FOR NUMEROUS LOCATIONS
THROUGHOUT THE HYDROLOGICAL SERVICES AREA FOR THE NEXT 5 TO 6 DAYS.
IN THE SHORT TERM... THE OLD H500 LOW WILL CYCLE EAST IN THE NEXT 24
TO 48 HOURS AND THEN DEPART. WITH ONLY LIGHT SHOWERS OR ISOLATED
THUNDER EXPECTED... RAINFALL WILL REMAIN LIGHT. FOLLOWING
THAT...HIGH PRESSURE WILL KEEP THE REGION RAIN FREE TO MONDAY
EVENING. THIS WILL SLOWLY ALLEVIATE THE SOME OF THE WATER ISSUES
THOUGH LARGER MAIN STEM RIVER SYSTEMS WILL REMAIN ABOVE FLOOD STAGE
THROUGH THE FORECAST PERIOD. ADDITIONAL MODERATE RAINFALL IS LIKELY
BEGINNING LATE MONDAY NIGHT THROUGH THURSDAY WHICH WILL NEED TO BE
WATCHED.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS EVENING FOR BUTLER.
&&
$$
SHORT TERM...FAB
LONG TERM...REV
AVIATION...FAB
HYDROLOGY...REV
AREA FORECAST DISCUSSION
NWS JACKSON KY
1025 AM EDT FRI MAY 31 2013
.UPDATE...
ISSUED AT 1024 AM EDT FRI MAY 31 2013
RADAR...SATELLITE AND LIGHTNING OBSERVATIONS ALL INDICATE A
WEAKENING TREND WITH CONVECTION OVER WESTERN KY. OUTFLOW FROM THIS
MAY TRIGGER CONVECTION OVER CENTRAL KY THIS AFTERNOON WITH A
MODERATELY UNSTABLE AIR MASS IN PLACE. THIS CONVECTION COULD THEN MAKE
ITS WAY INTO THE FORECAST AREA BY MID TO LATE AFTERNOON. THIS IDEA IS
SUPPORTED BY THE 12Z HRRR WHICH BRINGS SHOWERS AND THUNDERSTORMS INTO
THE WESTERN PART OF THE FORECAST AREA AROUND 20Z. PRIOR TO THIS
CONVECTION MAY BE INHIBITED DUE TO MID LEVEL CAPPING WHICH WAS
EVIDENT ON THE 12Z ILN SOUNDING. IN FACT THE SMALL SHOWERS THAT
DEVELOPED NORTHWEST OF FLEMING COUNTY AROUND 13Z EXHIBITED A WEAKENING
TREND ALMOST IMMEDIATELY AS THEY MOVED NNE INTO OH. THE HRRR DID A
GOOD JOB DEPICTING THE DEVELOPMENT OF SCATTERED SHOWERS IN THIS AREA
WITH A QUICK DISSIPATION TO THE SHOWERS. HAVE SLOWED THE ONSET OF
THUNDERSTORMS CHANCES FOR THIS AFTERNOON...AND LOWERED PROBABILITIES
ABOUT 10 PERCENT. WITH THIS IN MIND HAVE ALSO RAISED MAXIMUM
TEMPERATURES PRIMARILY IN THE EAST WHERE NEARLY THE ENTIRE DAY SHOULD
BE RAIN FREE. HOWEVER AFTERNOON TEMPERATURES WILL BE VERY DEPENDENT
ON SUNSHINE...AND THE CLOUD COVER FORECAST IS CHALLENGING AS DEBRIS
CLOUD FROM THIS MORNINGS CONVECTION MOVES EAST. UPDATED NDFD AND ZFP.
UPDATE ISSUED AT 735 AM EDT FRI MAY 31 2013
UPDATED THE FORECAST TO FINE TUNE THE POPS AND SKY THROUGH THE
MORNING HOURS....GENERALLY SLOWING THEM DOWN A TAD. ALSO APPLIED THE
LATEST OBS AND TRENDS TO THE T...TD...AND SKY GRIDS. IN ADDITION...
GIVEN THE ANTICIPATION OF ORGANIZED CONVECTIVE CLUSTERS AND UPPER
SUPPORT IN THE FORM OF THE TROUGH ANGLING THIS WAY ON SATURDAY WILL
ADD A BEEFIER MENTION OF THUNDERSTORMS...POSSIBLY SEVERE...TO THE
HWO. UPDATES HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. AN HWO
UPDATE WILL FOLLOW.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 350 AM EDT FRI MAY 31 2013
07Z SFC ANALYSIS SHOWS A LARGE AREA OF LOW PRESSURE...LOCATED OVER
THE NORTHERN PLAINS...STARTING TO AFFECT WESTERN KENTUCKY WHILE THE
WESTERN EXTENT OF HIGH PRESSURE OVER THE CAROLINAS IS HOLDING ON
OVER THE EAST. THIS HAS KEPT THE SKIES MOSTLY CLEAR THROUGH THE
NIGHT...THUS FAR...AND...WHEN COMBINED WITH LIGHT WINDS...ANOTHER
DECENT NIGHT OF RADIATIONAL COOLING IN UNDERWAY. AS IS NORMAL FOR
THESE SITUATIONS...THE SHELTERED VALLEYS HAVE DECOUPLED AND ARE
RUNNING A GOOD 10 DEGREES OR SO BELOW THE MILDER RIDGES WITH SPECIFIC
TEMPERATURES VARYING FROM AROUND 60 IN THE DEEPER SPOTS TO AROUND 70
ON THE HILLS...IN THE THERMAL BELT. DEWPOINTS ARE ABOUT THE SAME AS
LAST NIGHT WITH READINGS GENERALLY IN THE LOWER 60S. AGAIN...EXPECT
SOME PATCHY FOG IN THE DEEPER VALLEYS...BUT PRIMARILY JUST NEAR THE
RIVERS AND OTHER BODIES OF WATER.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE SOUTHEAST RIDGING...
THAT HAS PROTECTED THE AREA FROM MOST OF THE CONVECTION THESE PAST
COUPLE OF DAYS...YIELDING TO THE DEVELOPING DEEP AND BROAD MID LEVEL
LOW OVER THE NORTHERN PLAINS. A COUPLE OF LEADING SHORTWAVES WILL
MOVE INTO THE OHIO VALLEY TODAY...BRUSHING BY TO THE NORTH OF OUR
CWA. FOLLOWING THIS...THE UPPER LOW WILL SLIP INTO THE UPPER MIDWEST
AND AS A RESULT DRIVE THE HEIGHTS DOWN THROUGHOUT KENTUCKY DURING
THE DAY SATURDAY. WITH THE MODELS SUCH AGREEMENT...HAVE BASICALLY
FOLLOWED A GENERAL BLEND AND KEYED IN ON THE HIGHER RESOLUTION NAM12
AND HRRR FOR DETAILS.
SENSIBLE WEATHER WILL FEATURE A CHANCE OF SHOWERS AND
THUNDERSTORMS...CURRENTLY AFFECTING WESTERN KENTUCKY...MOVING INTO
THE WESTERN PORTIONS OF EAST KENTUCKY LATER THIS MORNING AND THEN
DRIFTING EAST DURING THE REST OF THE DAY. THE EXTRA CLOUDS AND PCPN
AROUND SHOULD BE ENOUGH TO KEEP HIGH TEMPERATURES A BIT COOLER THAN
YESTERDAY. THE DAYTIME CONVECTION...FUELED BY SOME UPPER LEVEL
HELP...LOW LIS...MODERATE CAPE...AND ABOVE NORMAL PWS...WILL DIE OFF
BY EARLY EVENING LEAVING A MUGGY AIR MASS BEHIND FOR THE NIGHT WITH
ONLY A SMALL RIDGE TO VALLEY DIFFERENCE EXPECTED...BUT MORE IN THE
WAY OF PATCHY FOG. SATURDAY WILL SEE THE APPROACH OF THE SYSTEM/S
MAIN COLD FRONT AND THIS SHOULD BE ENOUGH TO KICK OFF ADDITIONAL AIR
MASS SHOWERS AND STORMS GIVEN A SIMILAR THERMAL AND MOISTURE PROFILE
AS FRIDAY.
AGAIN USED THE CONSSHORT FOR TD AND WINDS THROUGH THE FIRST 24 HOURS
AS A STARTING POINT...WITH HIGHS A BIT LOWER THAN THURSDAY FOR BOTH
TODAY AND SATURDAY...WHILE USING THE CONSALL FOR A STARTING POINT
TONIGHT. AS FOR POPS...GENERALLY ENDED UP CLOSER TO THE HIGHER MET
NUMBERS THROUGHOUT THE SHORT TERM PORTION OF THE FORECAST.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 300 AM EDT FRI MAY 31 2013
A MID/UPPER LEVEL TROUGH WILL SWING ACROSS KENTUCKY SATURDAY NIGHT
INTO SUNDAY NIGHT...PRODUCING A PERIOD OF SHOWERS AND THUNDERSTORMS
FOR THE AREA. MODELS ARE ALL IN PRETTY DECENT AGREEMENT SO HAVE
INCREASED POPS FROM LATE SATURDAY NIGHT INTO SUNDAY. SEVERE THREAT
IS FAIRLY MINIMAL AS CLOUD COVER MAY LIMIT INSTABILITY AND SHEAR IS
QUITE WEAK. FRONT WILL DEPART TO THE SOUTH SUNDAY NIGHT...WITH RAIN
CHANCES DROPPING SOUTHEASTWARD. A COOLER AND LESS HUMID AIRMASS WILL
SETTLE INTO THE AREA FOR THE EARLY PORTION OF NEXT WEEK...ALLOWING
FOR VERY PLEASANT CONDITIONS FOR EARLY JUNE. ANOTHER RIDGE OF HIGH
PRESSURE WILL BUILD OVER THE SOUTHEAST BY THE MIDDLE TO LATE
PORTIONS OF NEXT WEEK WITH RETURN FLOW AGAIN ESTABLISHING ITSELF
OVER THE AREA. AS MOISTURE INCREASES BY MIDWEEK...RAIN CHANCES WILL
SLOWLY RAMP UP SIMILAR TO THIS PAST WEEK. TEMPERATURES WILL TURN
MILDER AS WELL AS THE WEEK GOES ON. MODELS ARE ALL IN DECENT
AGREEMENT THROUGH THE END OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 745 AM EDT FRI MAY 31 2013
A COUPLE MID LEVEL SHORTWAVES WILL PASS JUST NORTH OF THE AREA TODAY.
THE FIRST OF THESE IS RESPONSIBLE FOR THE AREA OF CONVECTION OVER
WESTERN KENTUCKY. THIS AREA IS EXPECTED TO PUSH EAST INTO THE AREA
LATE THIS MORNING...BUT QUESTIONS REMAIN WHETHER IT WILL BE DECAYING
OR STEADY STATE WHEN IT ENTERS...AIDED BY THE BUILDING INSTABILITY
WROUGHT BY DIURNAL HEATING. SINCE THE EXACT TIMING AND LOCATION OF
THIS REMNANT OR HEALTHY CONVECTIVE CLUSTER COME MIDDAY IS STILL
UNCERTAIN HAVE GONE WITH VCTS. THIS FIRST SURGE OF CONVECTION WILL
DIE OUT BY EVENING AND FOLLOWING THAT EXPECT THE CIGS TO SCATTER OUT.
THE INPUT OF MORE MOISTURE IN THE ENVIRONMENT WILL INCREASE THE
POTENTIAL FOR PATCHY VALLEY FOG LATE TONIGHT. WINDS THROUGHOUT THE
PERIOD WILL BE AROUND 10 KTS...OR LESS...AND GENERALLY FROM THE
SOUTH.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SBH
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
745 AM EDT FRI MAY 31 2013
.UPDATE...
ISSUED AT 735 AM EDT FRI MAY 31 2013
UPDATED THE FORECAST TO FINE TUNE THE POPS AND SKY THROUGH THE
MORNING HOURS....GENERALLY SLOWING THEM DOWN A TAD. ALSO APPLIED THE
LATEST OBS AND TRENDS TO THE T...TD...AND SKY GRIDS. IN ADDITION...
GIVEN THE ANTICIPATION OF ORGANIZED CONVECTIVE CLUSTERS AND UPPER
SUPPORT IN THE FORM OF THE TROUGH ANGLING THIS WAY ON SATURDAY WILL
ADD A BEEFIER MENTION OF THUNDERSTORMS...POSSIBLY SEVERE...TO THE
HWO. UPDATES HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. AN HWO
UPDATE WILL FOLLOW.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 350 AM EDT FRI MAY 31 2013
07Z SFC ANALYSIS SHOWS A LARGE AREA OF LOW PRESSURE...LOCATED OVER
THE NORTHERN PLAINS...STARTING TO AFFECT WESTERN KENTUCKY WHILE THE
WESTERN EXTENT OF HIGH PRESSURE OVER THE CAROLINAS IS HOLDING ON
OVER THE EAST. THIS HAS KEPT THE SKIES MOSTLY CLEAR THROUGH THE
NIGHT...THUS FAR...AND...WHEN COMBINED WITH LIGHT WINDS...ANOTHER
DECENT NIGHT OF RADIATIONAL COOLING IN UNDERWAY. AS IS NORMAL FOR
THESE SITUATIONS...THE SHELTERED VALLEYS HAVE DECOUPLED AND ARE
RUNNING A GOOD 10 DEGREES OR SO BELOW THE MILDER RIDGES WITH SPECIFIC
TEMPERATURES VARYING FROM AROUND 60 IN THE DEEPER SPOTS TO AROUND 70
ON THE HILLS...IN THE THERMAL BELT. DEWPOINTS ARE ABOUT THE SAME AS
LAST NIGHT WITH READINGS GENERALLY IN THE LOWER 60S. AGAIN...EXPECT
SOME PATCHY FOG IN THE DEEPER VALLEYS...BUT PRIMARILY JUST NEAR THE
RIVERS AND OTHER BODIES OF WATER.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE SOUTHEAST RIDGING...
THAT HAS PROTECTED THE AREA FROM MOST OF THE CONVECTION THESE PAST
COUPLE OF DAYS...YIELDING TO THE DEVELOPING DEEP AND BROAD MID LEVEL
LOW OVER THE NORTHERN PLAINS. A COUPLE OF LEADING SHORTWAVES WILL
MOVE INTO THE OHIO VALLEY TODAY...BRUSHING BY TO THE NORTH OF OUR
CWA. FOLLOWING THIS...THE UPPER LOW WILL SLIP INTO THE UPPER MIDWEST
AND AS A RESULT DRIVE THE HEIGHTS DOWN THROUGHOUT KENTUCKY DURING
THE DAY SATURDAY. WITH THE MODELS SUCH AGREEMENT...HAVE BASICALLY
FOLLOWED A GENERAL BLEND AND KEYED IN ON THE HIGHER RESOLUTION NAM12
AND HRRR FOR DETAILS.
SENSIBLE WEATHER WILL FEATURE A CHANCE OF SHOWERS AND
THUNDERSTORMS...CURRENTLY AFFECTING WESTERN KENTUCKY...MOVING INTO
THE WESTERN PORTIONS OF EAST KENTUCKY LATER THIS MORNING AND THEN
DRIFTING EAST DURING THE REST OF THE DAY. THE EXTRA CLOUDS AND PCPN
AROUND SHOULD BE ENOUGH TO KEEP HIGH TEMPERATURES A BIT COOLER THAN
YESTERDAY. THE DAYTIME CONVECTION...FUELED BY SOME UPPER LEVEL
HELP...LOW LIS...MODERATE CAPE...AND ABOVE NORMAL PWS...WILL DIE OFF
BY EARLY EVENING LEAVING A MUGGY AIR MASS BEHIND FOR THE NIGHT WITH
ONLY A SMALL RIDGE TO VALLEY DIFFERENCE EXPECTED...BUT MORE IN THE
WAY OF PATCHY FOG. SATURDAY WILL SEE THE APPROACH OF THE SYSTEM/S
MAIN COLD FRONT AND THIS SHOULD BE ENOUGH TO KICK OFF ADDITIONAL AIR
MASS SHOWERS AND STORMS GIVEN A SIMILAR THERMAL AND MOISTURE PROFILE
AS FRIDAY.
AGAIN USED THE CONSSHORT FOR TD AND WINDS THROUGH THE FIRST 24 HOURS
AS A STARTING POINT...WITH HIGHS A BIT LOWER THAN THURSDAY FOR BOTH
TODAY AND SATURDAY...WHILE USING THE CONSALL FOR A STARTING POINT
TONIGHT. AS FOR POPS...GENERALLY ENDED UP CLOSER TO THE HIGHER MET
NUMBERS THROUGHOUT THE SHORT TERM PORTION OF THE FORECAST.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 300 AM EDT FRI MAY 31 2013
A MID/UPPER LEVEL TROUGH WILL SWING ACROSS KENTUCKY SATURDAY NIGHT
INTO SUNDAY NIGHT...PRODUCING A PERIOD OF SHOWERS AND THUNDERSTORMS
FOR THE AREA. MODELS ARE ALL IN PRETTY DECENT AGREEMENT SO HAVE
INCREASED POPS FROM LATE SATURDAY NIGHT INTO SUNDAY. SEVERE THREAT
IS FAIRLY MINIMAL AS CLOUD COVER MAY LIMIT INSTABILITY AND SHEAR IS
QUITE WEAK. FRONT WILL DEPART TO THE SOUTH SUNDAY NIGHT...WITH RAIN
CHANCES DROPPING SOUTHEASTWARD. A COOLER AND LESS HUMID AIRMASS WILL
SETTLE INTO THE AREA FOR THE EARLY PORTION OF NEXT WEEK...ALLOWING
FOR VERY PLEASANT CONDITIONS FOR EARLY JUNE. ANOTHER RIDGE OF HIGH
PRESSURE WILL BUILD OVER THE SOUTHEAST BY THE MIDDLE TO LATE
PORTIONS OF NEXT WEEK WITH RETURN FLOW AGAIN ESTABLISHING ITSELF
OVER THE AREA. AS MOISTURE INCREASES BY MIDWEEK...RAIN CHANCES WILL
SLOWLY RAMP UP SIMILAR TO THIS PAST WEEK. TEMPERATURES WILL TURN
MILDER AS WELL AS THE WEEK GOES ON. MODELS ARE ALL IN DECENT
AGREEMENT THROUGH THE END OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 745 AM EDT FRI MAY 31 2013
A COUPLE MID LEVEL SHORTWAVES WILL PASS JUST NORTH OF THE AREA TODAY.
THE FIRST OF THESE IS RESPONSIBLE FOR THE AREA OF CONVECTION OVER
WESTERN KENTUCKY. THIS AREA IS EXPECTED TO PUSH EAST INTO THE AREA
LATE THIS MORNING...BUT QUESTIONS REMAIN WHETHER IT WILL BE DECAYING
OR STEADY STATE WHEN IT ENTERS...AIDED BY THE BUILDING INSTABILITY
WROUGHT BY DIURNAL HEATING. SINCE THE EXACT TIMING AND LOCATION OF
THIS REMNANT OR HEALTHY CONVECTIVE CLUSTER COME MIDDAY IS STILL
UNCERTAIN HAVE GONE WITH VCTS. THIS FIRST SURGE OF CONVECTION WILL
DIE OUT BY EVENING AND FOLLOWING THAT EXPECT THE CIGS TO SCATTER OUT.
THE INPUT OF MORE MOISTURE IN THE ENVIRONMENT WILL INCREASE THE
POTENTIAL FOR PATCHY VALLEY FOG LATE TONIGHT. WINDS THROUGHOUT THE
PERIOD WILL BE AROUND 10 KTS...OR LESS...AND GENERALLY FROM THE
SOUTH.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS CARIBOU ME
926 AM EDT FRI MAY 31 2013
.SYNOPSIS...
A WARM RIDGE OF HIGH PRESSURE WILL BUILD REMAIN OVER MUCH OF THE
REGION INTO THE WEEKEND. A COLD FRONT WILL BRIEFLY SLIP SOUTHWARD
ACROSS NORTHERN AREAS LATER TONIGHT BEFORE PUSHING BACK TO THE
NORTHEAST AS A WARM FRONT LATE SATURDAY AND SATURDAY NIGHT. A STRONGER
COLD FRONT WILL CROSS THE REGION SUNDAY NIGHT THROUGH MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
9AM UPDATE...
HAVE ADDED ENHANCED WORDING FOR LOCALLY HEAVY RAINFALL AND GUSTY
WINDS THIS AFTERNOON AND EVENING...MOSTLY FOR NORTHERN AROOSTOOK
COUNTY. AS A FRONTAL BOUNDARY SAGS SOUTHWARD THIS EVENING TOWARDS
THE SAINT JOHN VALLEY...THE COMBINATION OF DAYTIME HEATING...DEW
POINTS IN THE 60S AND SIGNIFICANT INSTABILITY TO THE TROP WILL
PRODUCE HEAVY THUNDERSTORMS. 12Z RAOBS FROM CAR AND MANIWAKI AS
WELL AS BUFKIT FORECAST SOUNDINGS SHOW A DEEP DRY LAYER FROM THE
SFC TO H800. AS A RESULT...WINDS ARE ASSESSED AS THE MOST SIGNIFICANT
THREAT BESIDES HEAVY DOWNPOURS. PWATS ARE OVER AN INCH AND A HALF.
THE HRRR SEEMS TO HAVE A REASONABLE HANDLE ON THE SITUATION WITH
STRONGER CELLS ENTERING THE SAINT JOHN VALLEY THIS EVENING.
635 AM UPDATE...WHAT`S LEFT OF THE ISOLATED TSTM THAT ENTERED THE
WESTERN MAINE BORDER NEAR DAAQUAM EARLIER THIS MORNING HAS BEEN
MOVING STEADILY SOUTHEAST AND WILL BE NEAR HOULTON SHORTLY. NOT
MUCH LTNG WITH THIS CELL AT THE MOMENT BUT WILL CONTINUE TO
MENTION ISOLATED THUNDER THIS MORNING...BUT THE BEST CHANCE FOR
THUNDER WILL BE THIS AFTERNOON. JUST SOME MINOR TWEAKS OTHERWISE
NO SIGNIFICANT CHANGES.
UNSEASONABLY WARM WEATHER CAN BE EXPECTED TODAY AS TEMPERATURES ARE
EXPECTED TO SOAR INTO THE LOW TO MID 80S ACROSS MOST OF NORTHERN AND
DOWNEAST MAINE TODAY. A COLD FRONT WILL APPROACH NORTHERN MOST MAINE
THIS AFTERNOON. THIS BOUNDARY WILL BE THE FOCUS FOR SCATTERED SHOWER
AND TSTM DEVELOPMENT...MAINLY THIS AFTERNOON. SB CAPE VALUES ARE
FORECASTED TO RANGE FROM 500 TO 1000 J/KG WITH EVEN HIGHER CAPE
VALUES ACROSS PORTIONS OF INTERIOR DOWNEAST MAINE WHERE MORE IN THE
WAY OF SURFACE HEATING IS EXPECTED.
DESPITE THE HIGHER CAPE VALUES THE BEST CHANCE OF ANY ORGANIZED
THUNDERSTORM DEVELOPMENT WILL BE ACROSS FAR NORTHERN MAINE AND
ESPECIALLY THE SAINT JOHN VALLEY WHERE THE APPROACHING BOUNDARY
WILL PROVIDE A FOCUS FOR CONVECTIVE DEVELOPMENT. ALTHOUGH WE ARE
EXPECTING ANY THUNDERSTORMS TO REMAIN BELOW SEVERE LIMITS AT THIS
TIME. ACROSS CENTRAL AND DOWNEAST MAINE EXPECT ISOLATED
THUNDERSTORMS.
EXPECT THE FRONTAL BOUNDARY TO SAG INTO NORTHERN MAINE OVERNIGHT AND
THIS WILL RESULT IN A CONTINUED CHANCE FOR SHOWERS AND PERHAPS A FEW
THUNDERSTORMS CONTINUING INTO THIS EVENING. PATCHY FOG WILL ALSO BE
POSSIBLE. LOWS TONIGHT WILL GENERALLY BE IN THE 60S.
NOTE: THE MAINE DEPARTMENT OF ENVIRONMENTAL PROTECTION HAS ISSUED AN
AIR QUALITY ALERT FOR THE DOWNEAST COAST FOR UNHEALTHY FOR SENSITIVE
GROUPS DUE TO OZONE. THIS ALERT IS IN EFFECT FRO 11 AM UNTIL 11 PM
TONIGHT.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
NOT MUCH CHANGE FROM PREVIOUS THINKING AS MODELS REMAIN VRY
CONSISTENT W/ THEIR GUIDANCE THRU THIS PD... BACK DOOR COLD FRONT
STILL EXPECTED TO STALL FROM NW-SE MAINE SAT AM THEN LIFT NEWRD AS
A WARM FRONT LATE SAT THRU SAT NGT. WILL KEEP HIGHEST POPS (CHC TO
LOW LIKELY POPS) ACROSS THE CENTRAL AND N THRU SAT NGT FOR SHOWERS
AND OCNL THUNDER AS VRY WARM AND UNSTABLE AIR W AND SW OF THIS
FRONT OVERRUNS THIS BNDRY. THIS FRONT SHOULD ALSO CREATE A RATHER
DECENT NE-SW THERMAL GRADIENT ACROSS THE REGION W/ COOLEST TEMPS
FAR NERN AREAS WHERE CLD/SHOWERS AND BEING ON THE COOL SIDE OF THE
BNDRY SHOULD KEEP MAXES ON SAT IN THE LOWER-MID 70S WHILE OUR FAR
SWRN AREAS IN THE WARM AND HUMID AIRMASS COULD SEE TEMPS INTO THE
UPPER 80S OR EVEN TO 90 DEPENDING ON CLD CVR. BY LATE SAT NGT/ERLY
SUN AM...ALL AREAS BACK INTO THE WARM AND STICKY AIR W/ A STRONG
COLD FRONT THEN FCST TO APPROACH OUR FAR WRN/NWRN AREAS LATER SUN
AFTN. SFC-BASED CAPES OF 1500-2500 J/KG...MDT SHEAR AHEAD OF A
STRONG COLD FRONT SUGGESTS AN ELEVATED THREAT OF STRONG TO PSBLY
SEVERE STORMS SPCLY OUR WRN/NWRN AREAS FOR SUN AFTN. WILL CONT
ENHANCED WORDING AND CONTD MENTION IN THE HWO. FLASH FLOODING
RISKS REMAIN A CONCERN AS WELL W/ THE HVY RAINS AND SATURATED
SOIL FROM THIS PAST WEEKEND...
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE STRONG COLD FRONT ADDRESSED IN THE SHORT TERM SECTION ABV IS
FCST TO SLOWLY CROSS THE FA SUN NGT THRU MON AND EXIT OUR FAR
SERN AREAS BY ERLY TUE AM. THIS SLOW TRANSITION ACROSS THE FCST
AREA SUGGESTS AN ELEVATED THREAT FOR CONVECTION ACROSS OUR SERN
AREAS MON AFTN AND HAVE CARRIED LIKELY POPS FOR SHOWERS/TSTMS MON
AFTN OUR SERN ZNS... OTHERWISE...GRADUALLY COOLER AND DRIER AIR
IS FCST TO OVERSPREAD THE AREA THRU THE PD AS COOL CANADIAN HIGH
PRES BUILD INTO THE REGION. WILL KEEP MENTION OF SHOWERS ACROSS
THE N TUE AFTN AS A COLD UPPER TROF SWINGS EWRD ACROSS THE AREA...
&&
.AVIATION /13Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: VFR THIS MORNING WITH SOME LOCAL MVFR IN PATCHY FOG.
MAINLY VFR THIS AFTERNOON AND TONIGHT EXCEPT LCL MVFR IN SCATTERED
SHOWERS AND TSTMS.
SHORT TERM: MVFR TO PSBL IFR CONDS ACROSS THE NRN TAF SITES
SAT/SAT NGT IN SHOWERS/OCNL THUNDER ASSOCIATED W/ A FRONTAL BNDRY
WHICH WILL EVENTUALLY LIFT NE OF THE AREA BY LATER SAT NGT THEN
ANOTHER ROUND OF MVFR TO BRIEF IFR W/ SHOWERS/TSTMS LATER SUN AFTN
AS A STRONG COLD FRONT APPROACHES.
FOR THE SRN TAF SITES...EXPECT MAINLY VFR CONDS W/ SOME PSBL LATE
NGT/ERLY AM FOG SAT NGT. MVFR TO BRIEF IFR CONDS EXPECTED LATE SUN
INTO MON AS A STRONG COLD FRONT APPROACHES THEN CROSSES THESE AREAS...
&&
.MARINE...
NEAR TERM: WINDS/SEAS WILL REMAIN BELOW SCA LEVELS THROUGH TONIGHT.
SHORT TERM: WARM RIDGE OF HIGH PRES ACROSS THE WATERS THRU THE PD
WILL KEEP RATHER STABLE CONDS IN PLACE INTO SUN. BY LATER
SUN...DESPITE THIS STABILITY...A STRONG APPROACHING COLD FRONT MAY
ALLOW WND GUSTS TO REACH MARGINAL SCA LEVELS. SEAS MAY ALSO
INCREASE TO MARGINAL SCA LEVELS IN PERSISTENT SW FLOW IN ADVANCE
OF THIS APPROACHING FRONT BY LATER SUN...
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DUDA/MCW
SHORT TERM...KHW
LONG TERM...KHW
AVIATION...DUDA/MCW/KHW
MARINE...DUDA/MCW/KHW
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
709 AM EDT FRI MAY 31 2013
.SYNOPSIS...
HIGH PRESSURE REMAINS ANCHORED OFF THE MID ATLANTIC COAST THROUGH
SUNDAY. A COLD FRONT WILL BRING INCREASING RAIN CHANCES...AS IT
SLOWLY CROSSES THE AREA ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
VERY SIMILAR DAY WXWISE TO THU ON THE WAY FOR TODAY. EXPECTING
ANOTHER VERY WARM DAY, AS THE SFC RIDGE AND STRENGTHENING H5 RIDGE
ALOFT REMAINS QUASI- STATIONARY WELL OFFSHORE.
DRY WEATHER CONTINUES TODAY WITH PERSISTENT WARM/STABLE AIR ALOFT
AND A LACK OF AVAILABLE TRIGGERS FOR LIFT. HIGH-RES MODELS
(SPECIFICALLY THE HRRR AND SPC WRF) AGAIN PICKING UP THE THE
POTENTIAL FOR AN ISOLATED SHOWER OR TWO BLOWING UP ON AFTN
SEABREEZE OVER THE FAR SOUTHEAST PART OF THE CWA (AND ALSO ALONG
THE MASON-DIXON IN ASSN WITH A WEAK, SHEARED OUT SHORTWAVE
CROSSING WELL NORTH OF THE AKQ CWA). AS WITH YESTERDAY THOUGH,
RAIN CHC ACROSS LOCAL AREA REMAINS TOO SMALL TO INCLUDE POPS IN
THE FORECAST. THUS, HV CONTINUED TO CAP RAIN CHANCES AT 10% OR
LESS. HIGH TEMPERATURES AWAY FROM THE IMMEDIATE COAST AGAIN
GENERALLY ~90/L90S INLAND, LOW TO MID 80S AT IMMEDIATE COASTAL
AREAS.
CLEAR AND MILD OVERNIGHT...EARLY MORNING LOWS SAT MORNING IN THE
U60S TO NR 70.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
GRADUALLY WEAKENING H5 RIDGE OFF THE MID ATLANTIC COAST SHIFTS
SLIGHTLY TO THE EAST SATURDAY AND SUNDAY AHEAD OF APPROACHING
MID-LVL TROUGH, WHICH PUSHES FROM THE NORTHERN PLAINS TOWARDS THE
UPR GRT LAKES ON SUNDAY. HOWEVER, SFC/UPR LEVEL RIDGING OFFSHORE
WL REMAIN THE DOMINATE WX FEATURE THRU THE WEEKEND, BRINGING
CONTINUED SUMMER-LIKE CONDITIONS. LTL (IF ANY) TRIGGER EXISTS FOR
CONVECTION ON SAT, AS AIRMASS REMAINS LARGELY CAPPED. FCST
REMAINS DRY AS BEST CHCS FOR ANY CONVECTION WILL AGAIN BE CONFINED
OVER THE MTNS. HIGHS SAT IN THE U80S-L90S, THOUGH AGAIN COOLER AT
THE BEACHES DUE TO LCL AFTN SEA BREEZE EFFECTS.
PARTLY TO MOSTLY CLEAR SKY FOR MOST OF SAT NIGHT, THOUGH WL NEED
TO WATCH GFS, AS IT CONTINUES TO KEY IN ON POTENTIAL FOR SOME LOW
STRATUS OVER THE I-85 CORRIDOR BACK INTO THE CENTRAL NC PIEDMONT
LATE. ERY MORNING LOWS SUNDAY MORNING IN THE M-U60S.
AFTER ANY LINGERING STRATUS QUICKLY LIFTS/ERODES SUNDAY MORNING,
THE DAY STARTS OUT MAINLY SUNNY. HOWEVER, CLOUDS LOOK TO INCREASE
FROM THE WEST BY SUN AFTN AHEAD OF APPROACHING FRONTAL BOUNDARY.
SLIGHT CHC TO LOW CHC POPS STILL LOOK GOOD BY MID AFTN SUNDAY AS
TSRAS LOOK TO FIRE ALONG PRE-FRONTAL/LEE TROUGHING TO THE WEST AND
PUSH E-NE ACROSS OUR WESTERN TIER OF COUNTIES (WEST OF RIC) LATE
SUN AFTN. MORE IN THE WAY OF CLOUD COVER WILL BE BALANCED OUT BY
STRONG COMPRESSIONAL HEATING AHEAD OF THE FRONT, AGAIN YIELDING
HIGHS IN THE U80S TO NR 90. GIVEN DP TEMPS IN THE L-M60S (HIGHEST
JUST BEFORE DIURNAL MIXING KICKS IN JUST AFTER 12Z)...HEAT INDEX
VALUES XPCTD TO REMAIN WITHIN A DEGREE OR TWO OF ACTUAL TEMPS BOTH
DAYS.
ECMWF/GFS IN PRETTY GOOD AGREEMENT REGARDING FROPA/PCPN TIMING FOR
SUNDAY NIGHT AND MONDAY. FRONT SLOWLY APPROACHES, AND BEGINS TO
PUSH ACROSS THE WESTERN THIRD OF THE LOCAL AREA LATE SUNDAY
NIGHT/MONDAY MORNING. DUE TO THE LATE NIGHT/ERY MORNING TIMING,
INSTABILITY ATTM LOOKS TO BE MARGINAL AT BEST, SO WILL GO WITH ISO
T WORDING FOR NOW. STILL, AS PW VALUES SHOOT UPWARDS OF 1.75"
AREA-WIDE SUNDAY NIGHT, RAIN CHANCES ARE LOOKING INCREASINGLY
FAVORABLE ACROSS THE PIEDMONT AFTER 00Z MON/8PM SUNDAY NIGHT.
THUS, WL GO WITH LKLY POP WEST OF I-95 LT SUNDAY NIGHT, WITH CHCS
INCREASING FARTHER EAST AFTER MIDNIGHT THRU DAWN MONDAY MORNING.
GIVEN THE CONSIDERABLE CLDS/PCPN, WL GO CLOSER TO EURO STATISTICAL
GUIDANCE, WHICH IS ABT A CATEGORY ABOVE 00Z/31 MEX NUMBERS. ERY
MORNING LOWS MON MORNING RIGHT AROUND 70/LOW 70S.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
LONG TERM PERIOD BEGINS W/ THE FRONT SLOWLY MOVING ACRS THE AREA
MON, WITH SHRAS/TSTMS EXPECTED ACROSS THE AREA. ALTHO WAA IS
WEAK...DEEP LAYER MOISTURE...MID-LVL S/W ENERGY AND UPR-LVL
DIVERGENCE CONTINUE TO WARRANT LIKELY POPS...CONTINUING INTO SE
AREAS MON NGT. GIVEN THE RAIN AND CLDS...TEMPS MON WILL MAX OUT IN
THE UPR 70S TO MID 80S. THE RAIN WILL END FROM W TO E EARLY TUE AS
THE FRONT SLIDES OFFSHORE. SFC HI PRES THEN BLDS IN FROM THE
NW...WITH HIGHS ONLY IN THE UPR 70S TO LO 80S ON TUE AND WED.
&&
.AVIATION /11Z FRIDAY THROUGH TUESDAY/...
MAINLY S-SW WINDS ARE EXPECTED TO CONTINUE FOR THE 12Z TAF PERIOD
WITH ONE POSSIBLE EXCEPTION. WINDS AT ORF MAY BE INFLUENCED ONCE
AGAIN BY A BAY BREEZE AS SYNOPTIC WINDS WILL BE A BIT LIGHTER THAN
ON THURSDAY. MODELS ARE NOT CLEAR ON THE DIRECTION AND WENT VRBL
AND LIGHT. NO SUBSTANTIAL CLOUDINESS IS INDICATED SO KEPT SKC
THROUGH THE PERIOD.
SOME LOCATIONS OTHER THAN THE TAF SITES REPORTED PATCHY FOG THIS
MORNING. WITH THE COLUMN SLOWLY MOISTENING WITH TIME...FOG DEVELOP
SATURDAY MORNING AT SOME OF THE TAF SITES WHERE WINDS DIMINISH
SUFFICIENTLY. INCLUDED 4 MILES AT RIC FOR NOW AFT 09Z. WINDS MAY
BE TOO STRONG AT THE OTHER FOUR SITES BUT THIS WILL NEED TO
MONITORED. CONFIDENCE IS LOW FOR THE MVFR STRATUS THAT MAV MOS HAS
FOR ECG.
OUTLOOK...THERE WILL BE A BETTER CHANCE FOR MVFR/IFR FOG OR
STRATUS SUNDAY MORNING. ISOLATED THUNDERSTORMS WILL BE PSBL
SUNDAY EVENING. THE CHANCES INCREASE MONDAY AHEAD OF AN
APPROACHING COLD FRONT. DRY/VFR CONDITIONS RETURN BY TUESDAY.
&&
.MARINE...
WINDS WILL CONTINUE TO BE GENERALLY FROM THE SOUTH THROUGH THE
WEEKEND. WIND SPEEDS AT ELEVATED SITES ARE RUNNING SEVERAL KNOTS
HIGHER THAN THOSE NEAR THE SURFACE OF THE WATER DUE TO POOR MIXING
WITH THE COLD WATER. THIS SHOULD CONTINUE TO BE THE CASE THROUGH THE
WEEKEND.
CONDITIONS SHOULD REMAIN BELOW SCA CRITERIA THROUGH THE DAY
SATURDAY. SOUTHERLY WINDS MAY GAIN ENOUGH SOUTHERLY FETCH TO PRODUCE
MARGINAL 5 FOOT SEAS OVER THE NORTHERN COASTAL WATERS BY SATURDAY
NIGHT. HOWEVER...THE MAIN SCA EVENT SHOULD BEGIN SUNDAY NIGHT OVER
THE COASTAL WATERS NORTH OF CAPE CHARLES. ELSEWHERE...CONDITIONS
SHOULD BE JUST SHORT OF SCA AS A COLD FRONT APPROACHES THE REGION.
THE FRONT MOVES SLOWLY TO THE EAST MONDAY NIGHT AND TUESDAY. PRESENT
INDICATIONS ARE THAT THE POST FRONTAL ENVIRONMENT WILL FAIL TO
PRODUCE SCA BUT THIS MAY CHANGE.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...AIR QUALITY ALERT UNTIL MIDNIGHT EDT TONIGHT FOR MDZ021>024.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...MPR/MAM
LONG TERM...MAS
AVIATION...LSA
MARINE...LSA
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
702 AM EDT FRI MAY 31 2013
.SYNOPSIS...
HIGH PRESSURE REMAINS ANCHORED OFF THE MID ATLANTIC COAST THROUGH
SUNDAY. A COLD FRONT WILL BRING INCREASING RAIN CHANCES...AS IT
SLOWLY CROSSES THE AREA ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
VERY SIMILAR DAY WXWISE TO THU ON THE WAY FOR TODAY. EXPECTING
ANOTHER VERY WARM DAY, AS THE SFC RIDGE AND STRENGTHENING H5 RIDGE
ALOFT REMAINS QUASI- STATIONARY WELL OFFSHORE.
DRY WEATHER CONTINUES TODAY WITH PERSISTENT WARM/STABLE AIR ALOFT
AND A LACK OF AVAILABLE TRIGGERS FOR LIFT. HIGH-RES MODELS
(SPECIFICALLY THE HRRR AND SPC WRF) AGAIN PICKING UP THE THE
POTENTIAL FOR AN ISOLATED SHOWER OR TWO BLOWING UP ON AFTN
SEABREEZE OVER THE FAR SOUTHEAST PART OF THE CWA (AND ALSO ALONG
THE MASON-DIXON IN ASSN WITH A WEAK, SHEARED OUT SHORTWAVE
CROSSING WELL NORTH OF THE AKQ CWA). AS WITH YESTERDAY THOUGH,
RAIN CHC ACROSS LOCAL AREA REMAINS TOO SMALL TO INCLUDE POPS IN
THE FORECAST. THUS, HV CONTINUED TO CAP RAIN CHANCES AT 10% OR
LESS. HIGH TEMPERATURES AWAY FROM THE IMMEDIATE COAST AGAIN
GENERALLY ~90/L90S INLAND, LOW TO MID 80S AT IMMEDIATE COASTAL
AREAS.
CLEAR AND MILD OVERNIGHT...EARLY MORNING LOWS SAT MORNING IN THE
U60S TO NR 70.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
GRADUALLY WEAKENING H5 RIDGE OFF THE MID ATLANTIC COAST SHIFTS
SLIGHTLY TO THE EAST SATURDAY AND SUNDAY AHEAD OF APPROACHING
MID-LVL TROUGH, WHICH PUSHES FROM THE NORTHERN PLAINS TOWARDS THE
UPR GRT LAKES ON SUNDAY. HOWEVER, SFC/UPR LEVEL RIDGING OFFSHORE
WL REMAIN THE DOMINATE WX FEATURE THRU THE WEEKEND, BRINGING
CONTINUED SUMMER-LIKE CONDITIONS. LTL (IF ANY) TRIGGER EXISTS FOR
CONVECTION ON SAT, AS AIRMASS REMAINS LARGELY CAPPED. FCST
REMAINS DRY AS BEST CHCS FOR ANY CONVECTION WILL AGAIN BE CONFINED
OVER THE MTNS. HIGHS SAT IN THE U80S-L90S, THOUGH AGAIN COOLER AT
THE BEACHES DUE TO LCL AFTN SEA BREEZE EFFECTS.
PARTLY TO MOSTLY CLEAR SKY FOR MOST OF SAT NIGHT, THOUGH WL NEED
TO WATCH GFS, AS IT CONTINUES TO KEY IN ON POTENTIAL FOR SOME LOW
STRATUS OVER THE I-85 CORRIDOR BACK INTO THE CENTRAL NC PIEDMONT
LATE. ERY MORNING LOWS SUNDAY MORNING IN THE M-U60S.
AFTER ANY LINGERING STRATUS QUICKLY LIFTS/ERODES SUNDAY MORNING,
THE DAY STARTS OUT MAINLY SUNNY. HOWEVER, CLOUDS LOOK TO INCREASE
FROM THE WEST BY SUN AFTN AHEAD OF APPROACHING FRONTAL BOUNDARY.
SLIGHT CHC TO LOW CHC POPS STILL LOOK GOOD BY MID AFTN SUNDAY AS
TSRAS LOOK TO FIRE ALONG PRE-FRONTAL/LEE TROUGHING TO THE WEST AND
PUSH E-NE ACROSS OUR WESTERN TIER OF COUNTIES (WEST OF RIC) LATE
SUN AFTN. MORE IN THE WAY OF CLOUD COVER WILL BE BALANCED OUT BY
STRONG COMPRESSIONAL HEATING AHEAD OF THE FRONT, AGAIN YIELDING
HIGHS IN THE U80S TO NR 90. GIVEN DP TEMPS IN THE L-M60S (HIGHEST
JUST BEFORE DIURNAL MIXING KICKS IN JUST AFTER 12Z)...HEAT INDEX
VALUES XPCTD TO REMAIN WITHIN A DEGREE OR TWO OF ACTUAL TEMPS BOTH
DAYS.
ECMWF/GFS IN PRETTY GOOD AGREEMENT REGARDING FROPA/PCPN TIMING FOR
SUNDAY NIGHT AND MONDAY. FRONT SLOWLY APPROACHES, AND BEGINS TO
PUSH ACROSS THE WESTERN THIRD OF THE LOCAL AREA LATE SUNDAY
NIGHT/MONDAY MORNING. DUE TO THE LATE NIGHT/ERY MORNING TIMING,
INSTABILITY ATTM LOOKS TO BE MARGINAL AT BEST, SO WILL GO WITH ISO
T WORDING FOR NOW. STILL, AS PW VALUES SHOOT UPWARDS OF 1.75"
AREA-WIDE SUNDAY NIGHT, RAIN CHANCES ARE LOOKING INCREASINGLY
FAVORABLE ACROSS THE PIEDMONT AFTER 00Z MON/8PM SUNDAY NIGHT.
THUS, WL GO WITH LKLY POP WEST OF I-95 LT SUNDAY NIGHT, WITH CHCS
INCREASING FARTHER EAST AFTER MIDNIGHT THRU DAWN MONDAY MORNING.
GIVEN THE CONSIDERABLE CLDS/PCPN, WL GO CLOSER TO EURO STATISTICAL
GUIDANCE, WHICH IS ABT A CATEGORY ABOVE 00Z/31 MEX NUMBERS. ERY
MORNING LOWS MON MORNING RIGHT AROUND 70/LOW 70S.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
LONG TERM PERIOD BEGINS W/ THE FRONT SLOWLY MOVING ACRS THE AREA
MON, WITH SHRAS/TSTMS EXPECTED ACROSS THE AREA. ALTHO WAA IS
WEAK...DEEP LAYER MOISTURE...MID-LVL S/W ENERGY AND UPR-LVL
DIVERGENCE CONTINUE TO WARRANT LIKELY POPS...CONTINUING INTO SE
AREAS MON NGT. GIVEN THE RAIN AND CLDS...TEMPS MON WILL MAX OUT IN
THE UPR 70S TO MID 80S. THE RAIN WILL END FROM W TO E EARLY TUE AS
THE FRONT SLIDES OFFSHORE. SFC HI PRES THEN BLDS IN FROM THE
NW...WITH HIGHS ONLY IN THE UPR 70S TO LO 80S ON TUE AND WED.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
MAINLY S-SW WINDS ARE EXPECTED TO CONTINUE FOR THE 12Z TAF PERIOD
WITH ONE POSSIBLE EXCEPTION. WINDS AT ORF MAY BE INFLUENCED ONCE
AGAIN BY A BAY BREEZE AS SYNOPTIC WINDS WILL BE A BIT LIGHTER THAN
ON THURSDAY. MODELS ARE NOT CLEAR ON THE DIRECTION AND WENT VRBL
AND LIGHT. NO SUBSTANTIAL CLOUDINESS IS INDICATED SO KEPT SKC
THROUGH THE PERIOD.
SOME LOCATIONS OTHER THAN THE TAF SITES REPORTED PATCHY FOG. WITH
THE COLUMN SLOWLY MOISTENING WITH TIME...FOG MAY BE REPORTED AT
SOME OF THE TAF SITES WHERE WINDS DIMINISH SUFFICIENTLY. INCLUDED
4 MILES AT RIC FOR NOW AFT 09Z. WINDS MAY BE TOO STRONG AT THE
OTHER FOUR SITES BUT THIS WILL NEED TO MONITORED. CONFIDENCE IS
LOW FOR THE MVFR STRATUS THAT MAV MOS HAS FOR ECG.
OUTLOOK...THERE WILL BE A BETTER CHANCE FOR MVFR/IFR FOG OR
STRATUS SUNDAY MORNING. ISOLATED THUNDERSTORMS WILL BE PSBL
SUNDAY EVENING. THE CHANCES INCREASE MONDAY AHEAD OF AN
APPROACHING COLD FRONT. DRY/VFR CONDITIONS RETURN BY TUESDAY.
&&
.MARINE...
WINDS WILL CONTINUE TO BE GENERALLY FROM THE SOUTH THROUGH THE
WEEKEND. WIND SPEEDS AT ELEVATED SITES ARE RUNNING SEVERAL KNOTS
HIGHER THAN THOSE NEAR THE SURFACE OF THE WATER DUE TO POOR MIXING
WITH THE COLD WATER. THIS SHOULD CONTINUE TO BE THE CASE THROUGH THE
WEEKEND.
CONDITIONS SHOULD REMAIN BELOW SCA CRITERIA THROUGH THE DAY
SATURDAY. SOUTHERLY WINDS MAY GAIN ENOUGH SOUTHERLY FETCH TO PRODUCE
MARGINAL 5 FOOT SEAS OVER THE NORTHERN COASTAL WATERS BY SATURDAY
NIGHT. HOWEVER...THE MAIN SCA EVENT SHOULD BEGIN SUNDAY NIGHT OVER
THE COASTAL WATERS NORTH OF CAPE CHARLES. ELSEWHERE...CONDITIONS
SHOULD BE JUST SHORT OF SCA AS A COLD FRONT APPROACHES THE REGION.
THE FRONT MOVES SLOWLY TO THE EAST MONDAY NIGHT AND TUESDAY. PRESENT
INDICATIONS ARE THAT THE POST FRONTAL ENVIRONMENT WILL FAIL TO
PRODUCE SCA BUT THIS MAY CHANGE.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...AIR QUALITY ALERT UNTIL MIDNIGHT EDT TONIGHT FOR MDZ021>024.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...MPR/MAM
LONG TERM...MAS
AVIATION...LSA
MARINE...LSA
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1130 AM EDT FRI MAY 31 2013
.SYNOPSIS...
A COLD FRONT WILL SLOWLY APPROACH FROM THE WEST THIS WEEKEND...THEN
CROSS THE REGION SUNDAY NIGHT THROUGH MONDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1130 AM FRIDAY...
OVERVIEW:
AN UPPER LEVEL RIDGE CENTERED ALONG THE SOUTHEAST AND MID-ATLANTIC
COAST WILL FURTHER WEAKEN THROUGH TONIGHT AS AN UPPER LEVEL LOW
CENTERED OVER THE NORTHERN PLAINS MOVES SLOWLY EAST INTO THE
NORTHERN MS RIVER VALLEY. A SFC-H85 RIDGE WILL PERSIST OFFSHORE OF
THE CAROLINAS...WITH AN INCREASINGLY MOIST SOUTHERLY RETURN FLOW
ACROSS THE REGION.
TEMPERATURES:
HIGHS TODAY APPEAR VERY SIMILAR TO THE PREVIOUS FEW DAYS GIVEN
LITTLE CHANGE IN THICKNESSES AND A VERY SIMILAR (ALBEIT INCREASINGLY
MOIST) AIRMASS. THE MAIN FACTORS W/REGARD TO HIGH TEMPS ARE APT TO
BE THE SEABREEZE APPROACHING FROM THE S/SE AND ISOLD CONVECTION
/OUTFLOW/ EXPECTED DURING THE MID TO LATE AFTERNOON...PRIMARILY EAST
OF HWY 1 AND SOUTH OF HWY 64 (SANDHILL/SE COASTAL PLAIN) WHERE THE
SEABREEZE PASSAGE WILL OCCUR THE EARLIEST...THOUGH EVEN IN THOSE
AREAS DIURNAL HEATING MAY BE SUFFICIENT FOR TEMPS TO REACH THE UPPER
80S. WITH THE ABOVE IN MIND...WILL INDICATE HIGHS IN THE MID/UPPER
80S...WARMEST IN VICINITY OF HWY 1. EXPECT LOWS TONIGHT SLIGHTLY
WARMER THAN LAST NIGHT DUE TO INCREASED BOUNDARY LAYER MOISTURE...
IN THE MID/UPPER 60S.
CONVECTION:
WEAK BUT PERSISTENT SOUTHERLY RETURN FLOW WILL ADVECT AN
INCREASINGLY MOIST AIRMASS FROM THE ATLANTIC INTO CENTRAL NC...
CHARACTERIZED BY SFC DEWPOINTS IN THE MID/UPPER 60S...H925 DEWPOINTS
OF 13-15C AND H85 DEWPOINTS OF 10-12C DURING THE MID/LATE AFTERNOON
HOURS. MID-LEVEL LAPSE RATES HAVE DECREASED IN COMPARISON TO
YESTERDAY AS THE RIDGE ALOFT WEAKENS...AND THE LATEST RAP GUIDANCE
SUGGEST H7-H5 LAPSE RATES ON THE ORDER OF 5.5-6.5 C/KM DURING PEAK
HEATING...STEEPEST IN THE EAST. IN THIS ENVIRONMENT...EXPECT
MODERATE DESTABILIZATION WITH MLCAPE VALUES OF 1000-1500 J/KG BY
PEAK HEATING AND LITTLE OR NO CIN. FORCING WILL LARGELY BE LIMITED
TO CONVERGENCE ALONG THE SEABREEZE THIS AFTERNOON...THOUGH LATEST WV
IMAGERY AND RAP DATA SUGGEST A WEAK N-S ORIENTED H3 SHEAR AXIS OVER
THE SOUTHERN APPALACHIANS SHOULD PROGRESS SLOWLY EAST INTO THE
WESTERN PIEDMONT BY 21-00Z. WITH THE ABOVE IN MIND...EXPECT A MORE
ACTIVE SEABREEZE THAN YESTERDAY...WITH ISOLD TO SCT SHOWERS AND
STORMS BETWEEN BY MID/LATE AFTERNOON...PRIMARILY SOUTH OF HWY 64
ACROSS THE EASTERN SANDHILLS AND SE COASTAL PLAIN...WITH ACTIVITY
WANING IN VICINITY OF THE TRIANGLE OR HWY 1 CORRIDOR BY OR SHORTLY
AFTER SUNSET. CONVECTION WILL REMAIN DISORGANIZED GIVEN NEGLIGIBLE
DEEP-LAYER SHEAR UNDER THE WEAKENING RIDGE...THOUGH MODERATE DCAPE
(~1000 J/KG) WOULD SUGGEST SOME POTENTIAL FOR ENHANCED COLD POOLS
AND PERHAPS AN ISOLD DOWNBURST...PRIMARILY ACROSS SCOTLAND...HOKE...
CUMBERLAND...SAMPSON AND WAYNE COUNTIES BETWEEN 19-23Z. -VINCENT
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...
SATURDAY/SATURDAY NIGHT...
WHILE HEIGHTS ALOFT BEGIN TO FALL EVER SO SLIGHTLY AHEAD OF THE
UPPER TROUGH MOVING INTO THE MID WEST STATES...THE MID-LEVEL RIDGE
OVER THE WESTERN ATLANTIC WILL REMAIN DOMINATE AS IT EXTENDS ACROSS
CENTRAL NC SATURDAY. THUS...EXPECT ANOTHER DAY OF AFTERNOON HIGHS
IN THE MID TO UPPER 80S AND ISOLATED SHOWERS POSSIBLE ALONG THE
SEABREEZE. MOISTURE TRANSPORT WILL BEGIN TO INCREASE ACROSS WESTERN
NC SATURDAY NIGHT AS THE MID-LEVEL RIDGE EASES EASTWARD. EXPECT A
FEW SHOWERS MAY BE POSSIBLE WEST OF THE YADKIN-RIVER...BUT WILL PLAN
TO KEEP THE RAH CWA DRY THROUGH 12Z...AWAITING THE ARRIVAL OF
STRONGER LOW-LEVEL FLOW AND DIURNAL HEATING. -SMITH
FOR SUNDAY/SUNDAY NIGHT: THE SLIGHTLY WEAKENING MID LEVEL TROUGH
AXIS APPROACHES OUR AREA FROM THE WEST... WITH MODELS DEPICTING A
WEAK PERTURBATION RIDING TO THE NORTHEAST UP THROUGH THE WRN/CENTRAL
CAROLINAS LATE SUNDAY INTO SUNDAY NIGHT... AS UPPER DIVERGENCE
INCREASES IN THE RIGHT ENTRANCE REGION OF A ST LAWRENCE VALLEY JET.
AS THE COLD FRONT APPROACHES FROM THE WEST... HIGH PRECIP WATER
(150-200% OF NORMAL) IS EXPECTED TO SURGE NORTHEASTWARD OVER WRN NC
SUNDAY AND INTO CENTRAL NC SUNDAY EVENING/NIGHT... ACCOMPANIED BY
INCREASING LOW LEVEL MOISTURE TRANSPORT. THE 50 KT LOW LEVEL JET
RIDES TO OUR NW ALONG THE CENTRAL APPALACHIANS EARLY SUNDAY BEFORE
SHIFTING UP INTO THE CANADIAN MARITIMES... LEAVING A MUCH MORE
SUBDUED 25-30 KT LOW LEVEL SPEED MAX FROM THE NRN PIEDMONT TO
COASTAL NEW ENGLAND... SO THE DYNAMIC FORCING FOR ASCENT AS WELL AS
THE KINEMATICS WILL GENERALLY BE RAMPING DOWN WITH MINIMAL DPVA.
INSTABILITY IS MARGINAL AS WELL WITH MODELS DEPICTING BRIEF MUCAPE
OF 1000-1500 J/KG OVER THE WRN CWA LATE SUNDAY WHILE THE SREF SHOWS
VERY LOW PROBABILITIES OF MLCAPE OVER 1000 J/KG AT ANY TIME...
LIKELY DUE IN PART TO WEAK MID LEVEL LAPSE RATES LESS THAN 6 C/KM.
BUT THE INCREASE IN MOISTURE AND WHAT WEAK LIFT THERE IS STILL SEEMS
TO SUPPORT CHANCE TO LOW-END LIKELY POPS SPREADING INTO AREAS WEST
OF HIGHWAY 1 LATE AFTERNOON AND THROUGH THE NIGHT. WILL ADJUST TO
BRING POPS EASTWARD A BIT LATER TO FIT WITH THE LATEST GUIDANCE
TIMING BUT WILL RETAIN THE GENERAL FLAVOR OF THE EARLIER FORECAST.
HIGHS 83-90... A LEAN TOWARD THE WARMER GFS-BASED STATISTICAL
GUIDANCE. ABOVE-GUIDANCE LOWS OF 68-72 WITHIN A PREFRONTAL WARM AIR
ADVECTION PATTERN. -GIH
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 245 AM FRIDAY...
FOR MONDAY/MONDAY NIGHT: BEST CHANCE OF SHOWERS/STORMS STILL LOOKS
TO BE IN THIS TIME FRAME. AS A STRONG VORTEX MOVES FROM SE ONTARIO
ACROSS SRN QUEBEC... THE WEAK SOUTHERN END OF THE TRAILING MID LEVEL
TROUGH EASES EASTWARD THROUGH THE AREA... ACCOMPANIED BY THE SURFACE
FRONT AND PRECEDED BY THE MINOR LOBE OF VORTICITY WHICH TRAVERSES
CENTRAL/ERN NC. THE ASCENT WILL BE ROOTED IN THE MID-UPPER LEVELS
WITH ONLY VERY WEAK MASS CONVERGENCE NEAR THE GROUND... BUT WITH
LIFT POTENTIALLY AUGMENTED BY 1000-1500 J/KG OF MLCAPE (FROM THE GFS
AND ECMWF)... IT SHOULD BE STRONG ENOUGH WITH THE EXPECTED DEEP
MOISTURE FOR LIKELY POPS AREAWIDE MONDAY... SLOWLY DECREASING WEST
TO EAST IN THE WEST MONDAY NIGHT BUT REMAINING LIKELY IN THE EAST.
CONFIDENCE IS HIGH THAT A PERIOD OF CATEGORICAL POPS WILL BE NEEDED
ONCE WE GET CLOSER AND CAN PIN DOWN TIMING A BIT BETTER. COULD SEE
UP TO AN INCH OF STORM-TOTAL RAIN BASED ON PRECIP WATER NEARING 2.0
INCHES AND A DEEP LCL-TO-0C LAYER AROUND 4 KM. HIGHS 77-84. LOWS
FROM 62 NW TO NEAR 70 SE.
FOR TUESDAY THROUGH THURSDAY: THE MID LEVEL SHEAR AXIS IS EXPECTED
TO SHIFT OFFSHORE BY TUESDAY MORNING WITH THE SURFACE FRONT DRIFTING
EASTWARD TO THE COASTAL AREA. THE ECMWF`S TROUGH IS NOTABLY WEAKER
AND MORE BAGGY THAN THE GFS`S... AND AS A RESULT THE ECMWF IS MUCH
SLOWER WITH THE FRONT... HANGING IT BACK FARTHER WEST... MEANING
CONTINUED WARM AIR/HIGH HUMIDITY AND RAIN CHANCES OVER ALL BUT THE
NW CWA. THINK THE ECMWF MAY BE ONTO SOMETHING GIVEN THAT THE
STRONGEST MID LEVEL FLOW WITH THE EASTERN CANADA LOW WILL HOLD NORTH
OF THE MASON-DIXON LINE. WILL HOLD ONTO AT LEAST CHANCE POPS FOR
SHOWERS SOUTH AND EAST OF RALEIGH THROUGH TUESDAY... WITH MORE
CLOUDS AND HIGHER DEW POINTS IN THE MID-UPPER 60S. THE QUEBEC VORTEX
LIFTS UP ACROSS ERN CANADA WHILE A SECOND LOW CROSSES THE DAKOTAS
TUESDAY NIGHT BEFORE SETTLING OVER THE UPPER MIDWEST THROUGH
MIDWEEK. FOR TUESDAY NIGHT THROUGH THURSDAY WE SHOULD BE UNDER THE
INFLUENCE OF THE CANADIAN SURFACE HIGH NOSING IN FROM THE NORTH
BENEATH WEAK MAINLY WESTERLY MID LEVEL FLOW... YIELDING FAIR SKIES
AND GENERALLY DRY CONDITIONS. THE RETURN EASTERLY FLOW AROUND THE
SURFACE HIGH STRENGTHENS BY THURSDAY WITH INCREASING ATLANTIC
INFLOW... AND THIS MAY RESULT IN A FEW SHOWERS OVER CENTRAL NC...
BUT THE CHANCE FOR SUFFICIENTLY DEEP MOISTURE IS TOO UNCERTAIN FOR
ANYTHING BUT SLIGHT CHANCE POPS FOR NOW. THICKNESSES SUPPORT TEMPS
NEAR NORMAL SE AND BELOW NORMAL NW ON TUESDAY... DROPPING TO ABOUT A
CATEGORY BELOW NORMAL FOR WEDNESDAY AND THURSDAY. -GIH
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 700 AM FRIDAY...
IFR/LIFR CONDITIONS ACROSS THE COASTAL PLAIN THIS MORNING HAS FOR
THE MOST REMAINED JUST TO THE EAST OF KRWI AND KFAY...THOUGH THE
STRATUS APPEARS TO ADVANCING NORTHWARD IN SOME AREAS. HAVE INCLUDED
A TEMPO AT THOSE SITES THROUGH 13Z. OTHERWISE...VFR CONDITIONS
SHOULD PREVAIL BY 14Z...WITH JUST A LIGHT SOUTHERLY WIND AND
SCATTERED CU THIS AFTERNOON. THERE IS A SMALL CHANCE OF A
SHOWER...MAINLY NEAR KFAY AFTER 18Z...AS THE SEABREEZE PUSHES
INLAND. EXPECT STRATUS AND FOG TO DEVELOP AGAIN TONIGHT BY BY
09Z...WITH THE HIGHEST CONFIDENCE FROM KRDU SOUTH AND EAST.
OUTLOOK...
VFR CONDITIONS ARE EXPECTED TO PREVAIL FOR MUCH OF THE
WEEKEND...WITH EARLY MORNING STRATUS/FOG POSSIBLE AGAIN SUNDAY. A
FEW ISOLATED SHOWERS/STORMS WILL BE POSSIBLE EACH AFTERNOON...MOSTLY
NEAR KFAY. MORE WIDESPREAD SHOWERS AND THUNDERSTORMS ARE
ANTICIPATED ALONG AND AHEAD OF A COLD FRONT EXPECTED TO PROGRESS
SLOWLY EASTWARD THROUGH CENTRAL NC SUNDAY NIGHT THROUGH MONDAY NIGHT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...SMITH/HARTFIELD
LONG TERM...HARTFIELD
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
948 AM CDT FRI MAY 31 2013
.UPDATE...
LATEST RADAR AND IR SATELLITE IMAGERY DEPICTS A WEAKENING MCS
OVER WESTERN ZONES WITH SHOWERS AND STORMS DIMINISHING IN
COVERAGE AND CLOUD TOPS WARMING SIGNIFICANTLY. ALTHOUGH HRRR
INDICATES ACTIVITY WILL CONTINUE MARCHING EASTWARD THROUGH THE
CWA...APPEARS MUCH OF THE CURRENT PRECIP WILL DISSIPATE PRIOR TO
REACHING THE I-65 CORRIDOR. NEVERTHELESS...VERY MOIST AIRMASS IN
PLACE SHOWN BY THE PWAT OF 1.67 INCHES ON THE 12Z OHX SOUNDING
ALONG WITH CONTINUED DAYTIME HEATING SHOULD SPAWN ADDITIONAL
SCATTERED SHOWERS AND STORMS AHEAD OF DYING MCS LATER TODAY. HAVE
RAISED POPS ACROSS CENTRAL AND WESTERN ZONES FOR THE MORNING HOURS
BASED ON CURRENT TRENDS...AND BUMPED UP CLOUD COVER AND LOWERED
HIGH TEMPS IN THE NORTHWEST. REST OF FORECAST REMAINS UNCHANGED.
SHAMBURGER
&&
.PREV DISCUSSION... /ISSUED 831 AM CDT FRI MAY 31 2013/
AVIATION UPDATE...
GOOD ROUND OF SHOWERS AND STORMS OVER WESTERN TENNESSEE HAVE
MOVED INTO NORTHWEST TENNESSEE WITH ISOLATED RENEGADE SHOWERS
FIXING TO MOVE INTO DAVIDSON COUNTY. H-TRIPLE-R DRIVE SHOWERS AND
STORMS CURRENTLY IN WEST TENNESSEE EASTWARD AS WE GO THROUGH THE
MORNING HOURS.
INFRARED SATELLITE LOOP SHOW TOPS WARMING ACROSS WESTERN TENNESSEE
WITH LIGHTNING STRIKES DECREASING.
BOYD
PREV DISCUSSION... /ISSUED 622 AM CDT FRI MAY 31 2013/
UPDATE...FOR 12Z AVIATION DISCUSSION.
AVIATION...12Z AVIATION DISCUSSION.
UNCERTAINTIES...HOW FAR WILL MOISTURE ASSOCIATED WITH DYING MCS MAKE IT INTO
MID STATE AND ASSOCIATED SHWR/TSTMS CHANCES. WILL GO WITH VFR CEILINGS THRU
01/12Z...WITH MAIN IMPACT OF SHWRS/TSTMS ACROSS CKV FROM 31/13Z-31/18Z. QUESTION
HOW FAR EWD MCS INFLUENCES WILL EXTEND...AND THUS WILL CONTINUE WITH ONLY
VCTS REMARKS AT BOTH BNA/CSV. EXPECT SOME ERROSION OF VFR CU CEILINGS AFTER
31/18Z W TO 31/22Z E...WITH AN INCREASE IN MOISTURE AHEAD OF UPPER LEVEL
DISTURBANCE ALLOWING FOR SCT/BKN STCU/AC/CI FROM 01/07Z W TO 01/12Z E. PER SFC
PRESSURE GRADIENT...EXPECT GUST TO 20KTS POSSIBLE 31/13Z W TO 01/03Z E.
PREV DISCUSSION.../ISSUED 554 AM CDT FRI MAY 31 2013/
UPDATE...
LATEST MODELS INDICATING THAT THE DEEPER MOISTURE WILL INDEED
TRANSITION NORTHEASTWARD ACROSS OUR NORTHWESTERN COUNTIES LATER
THIS MORNING. THIS IS FURTHER CONFIRMED BY RECENT RADAR TRENDS AND
TODAY`S HRRR DATA. WILL GO AHEAD AND INCREASE POPS...PRIMARILY
ACROSS WESTERN AND NORTH CENTRAL ZONES.
PREV DISCUSSION... /ISSUED 333 AM CDT FRI MAY 31 2013/
MAIN COLD FRONTAL BOUNDARY IS STILL LOCATED WELL WEST OF TN AND
RESIDES ALONG THE CENTRAL PLAINS. MAIN FOCUS OF CONVECTION THIS
MORNING IS IN ASSOCIATION WITH A SERIES OF MCS`S FROM AR NE THROUGH
NRN IN. 850MB JET IS COMBINING WITH STRONG IMPULSES WITHIN THE SWLY
FLOW ALOFT TO KEEP THIS CONVECTION GOING OVERNIGHT. MODELS DO SHOW
AN EASTWARD MIGRATION OF THESE DYNAMICS FOR TODAY. ALTHOUGH THE
DYNAMICS WILL WEAKEN...HRRR DOES SUPPORT CONVECTION MOVING INTO OUR
NORTHWESTERN ZONES LATER THIS MORNING. CURRENTLY...CONVECTION HAS
MOVED INTO FAR WESTERN TN. THUS...POPS OF 30-50 PERCENT FOR
TODAY...GREATEST POPS WEST.
TONIGHT...COLD FRONT GETS A LITTLE CLOSER BUT AGAIN...THE BETTER MCS
COMPLEXES WILL REMAIN NW OF MIDDLE TN. MAY SEE SOME CONVECTIVE
ENCROACHMENT ON OUR FAR NW AREAS LATE TONIGHT AND WILL THUS INCLUDE
40 POPS NW...20 POPS ELSEWHERE.
ON SATURDAY...COLD FRONT WILL APPROACH THE MS RIVER BY LATE
AFTERNOON. MOISTURE AND INSTABILITY WILL BE RAMPING UP ACROSS THE
MID STATE AND POPS OF 30-60 PERCENT WILL BE ON ORDER. THE OVERALL
SYSTEM WILL BECOME MORE SFC ORIENTED AS THE MID AND UPPER JETS
REMAIN NORTH OF TN. NEVERTHELESS..FRONTAL IMPACTS WILL BE
FELT...ESPECIALLY ON SATURDAY NIGHT AND SUNDAY...WITH THE FROPA
OCCURRING ON SUNDAY.
AS FOR SEVERE CHANCES...ELEVATED CAPES WILL CONVERGE WITH FRONTAL
BASED SFC FORCING TO PROMOTE A SLIGHT RISK OF SEVERE ON SATURDAY AFT
AND EVENING...MAINLY WESTERN ZONES. THEN...AS THE FRONT MOVES
THROUGH ON SUNDAY...SEVERE WEATHER WILL BE POSSIBLE ACROSS EASTERN
ZONES DURING THE DAY. NOT REALLY SEEING MUCH OVERNIGHT SEVER WEATHER
POTENTIAL...UPPER DYNAMICS ARE LOOKING WEAKER AND 850 MB FLOW IS NOT
OVERLY IMPRESSIVE. DESCENT QPF TOTALS FOR THE SAT NT
OVERNIGHT...BUT OVERALL STORM DEINTENSIFICATION MAY BE THE RULE AS
WE LOSE THE DAYTIME HEATING AND THE ELEVATED DYNAMICS ARE NOT
OVERLY IMPRESSIVE.
AS FOR HEAVY RAINFALL POTENTIAL...LOOKS LIKE STORM TOTAL QPF OF UP
TO 2 INCHES IS POSSIBLE NW AREAS...1 TO 2 INCHES ELSEWHERE. THIS IS
NOT ESF WORTHY...BUT IT WILL CONTINUE TO BE MONITORED.
TEMPERATURE WISE...NO BIG DEVIATIONS VERSUS THE MAV.
IN THE EXT FCST...BOUNDARY MOVES THROUGH WITH DRIER POP FREE WEATHER
FOR THE EARLY HALF OF THE WORK WEEK. MOISTURE...HOWEVER...WILL
RETURN AS THE SFC HIGH SHIFTS EAST AND ALLOWS A SOUTHERLY LOW LEVEL
FLOW TO RETURN. TEMPS THROUGH THE EXTENDED ARE LOOKING SEASONAL.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
831 AM CDT FRI MAY 31 2013
.MESOSCALE AND AVIATION UPDATE...
GOOD ROUND OF SHOWERS AND STORMS OVER WESTERN TENNESSEE HAVE MOVED
INTO NORTHWEST TENNESSEE WITH ISOLATED RENEGADE SHOWERS FIXING TO
MOVE INTO DAVIDSON COUNTY. H-TRIPLE-R DRIVE SHOWERS AND STORMS
CURRENTLY IN WEST TENNESSEE EASTWARD AS WE GO THROUGH THE MORNING HOURS.
INFRARED SATELLITE LOOP SHOW TOPS WARMING ACROSS WESTERN TENNESSEE
WITH LIGHTNING STRIKES DECREASING.
BOYD
&&
.PREV DISCUSSION... /ISSUED 622 AM CDT FRI MAY 31 2013/
UPDATE...FOR 12Z AVIATION DISCUSSION.
AVIATION...12Z AVIATION DISCUSSION.
UNCERTAINTIES...HOW FAR WILL MOISTURE ASSOCIATED WITH DYING MCS MAKE IT INTO
MID STATE AND ASSOCIATED SHWR/TSTMS CHANCES. WILL GO WITH VFR CEILINGS THRU
01/12Z...WITH MAIN IMPACT OF SHWRS/TSTMS ACROSS CKV FROM 31/13Z-31/18Z. QUESTION
HOW FAR EWD MCS INFLUENCES WILL EXTEND...AND THUS WILL CONTINUE WITH ONLY
VCTS REMARKS AT BOTH BNA/CSV. EXPECT SOME ERROSION OF VFR CU CEILINGS AFTER
31/18Z W TO 31/22Z E...WITH AN INCREASE IN MOISTURE AHEAD OF UPPER LEVEL
DISTURBANCE ALLOWING FOR SCT/BKN STCU/AC/CI FROM 01/07Z W TO 01/12Z E. PER SFC
PRESSURE GRADIENT...EXPECT GUST TO 20KTS POSSIBLE 31/13Z W TO 01/03Z E.
PREV DISCUSSION.../ISSUED 554 AM CDT FRI MAY 31 2013/
UPDATE...
LATEST MODELS INDICATING THAT THE DEEPER MOISTURE WILL INDEED
TRANSITION NORTHEASTWARD ACROSS OUR NORTHWESTERN COUNTIES LATER
THIS MORNING. THIS IS FURTHER CONFIRMED BY RECENT RADAR TRENDS AND
TODAY`S HRRR DATA. WILL GO AHEAD AND INCREASE POPS...PRIMARILY
ACROSS WESTERN AND NORTH CENTRAL ZONES.
PREV DISCUSSION... /ISSUED 333 AM CDT FRI MAY 31 2013/
MAIN COLD FRONTAL BOUNDARY IS STILL LOCATED WELL WEST OF TN AND
RESIDES ALONG THE CENTRAL PLAINS. MAIN FOCUS OF CONVECTION THIS
MORNING IS IN ASSOCIATION WITH A SERIES OF MCS`S FROM AR NE THROUGH
NRN IN. 850MB JET IS COMBINING WITH STRONG IMPULSES WITHIN THE SWLY
FLOW ALOFT TO KEEP THIS CONVECTION GOING OVERNIGHT. MODELS DO SHOW
AN EASTWARD MIGRATION OF THESE DYNAMICS FOR TODAY. ALTHOUGH THE
DYNAMICS WILL WEAKEN...HRRR DOES SUPPORT CONVECTION MOVING INTO OUR
NORTHWESTERN ZONES LATER THIS MORNING. CURRENTLY...CONVECTION HAS
MOVED INTO FAR WESTERN TN. THUS...POPS OF 30-50 PERCENT FOR
TODAY...GREATEST POPS WEST.
TONIGHT...COLD FRONT GETS A LITTLE CLOSER BUT AGAIN...THE BETTER MCS
COMPLEXES WILL REMAIN NW OF MIDDLE TN. MAY SEE SOME CONVECTIVE
ENCROACHMENT ON OUR FAR NW AREAS LATE TONIGHT AND WILL THUS INCLUDE
40 POPS NW...20 POPS ELSEWHERE.
ON SATURDAY...COLD FRONT WILL APPROACH THE MS RIVER BY LATE
AFTERNOON. MOISTURE AND INSTABILITY WILL BE RAMPING UP ACROSS THE
MID STATE AND POPS OF 30-60 PERCENT WILL BE ON ORDER. THE OVERALL
SYSTEM WILL BECOME MORE SFC ORIENTED AS THE MID AND UPPER JETS
REMAIN NORTH OF TN. NEVERTHELESS..FRONTAL IMPACTS WILL BE
FELT...ESPECIALLY ON SATURDAY NIGHT AND SUNDAY...WITH THE FROPA
OCCURRING ON SUNDAY.
AS FOR SEVERE CHANCES...ELEVATED CAPES WILL CONVERGE WITH FRONTAL
BASED SFC FORCING TO PROMOTE A SLIGHT RISK OF SEVERE ON SATURDAY AFT
AND EVENING...MAINLY WESTERN ZONES. THEN...AS THE FRONT MOVES
THROUGH ON SUNDAY...SEVERE WEATHER WILL BE POSSIBLE ACROSS EASTERN
ZONES DURING THE DAY. NOT REALLY SEEING MUCH OVERNIGHT SEVER WEATHER
POTENTIAL...UPPER DYNAMICS ARE LOOKING WEAKER AND 850 MB FLOW IS NOT
OVERLY IMPRESSIVE. DESCENT QPF TOTALS FOR THE SAT NT
OVERNIGHT...BUT OVERALL STORM DEINTENSIFICATION MAY BE THE RULE AS
WE LOSE THE DAYTIME HEATING AND THE ELEVATED DYNAMICS ARE NOT
OVERLY IMPRESSIVE.
AS FOR HEAVY RAINFALL POTENTIAL...LOOKS LIKE STORM TOTAL QPF OF UP
TO 2 INCHES IS POSSIBLE NW AREAS...1 TO 2 INCHES ELSEWHERE. THIS IS
NOT ESF WORTHY...BUT IT WILL CONTINUE TO BE MONITORED.
TEMPERATURE WISE...NO BIG DEVIATIONS VERSUS THE MAV.
IN THE EXT FCST...BOUNDARY MOVES THROUGH WITH DRIER POP FREE WEATHER
FOR THE EARLY HALF OF THE WORK WEEK. MOISTURE...HOWEVER...WILL
RETURN AS THE SFC HIGH SHIFTS EAST AND ALLOWS A SOUTHERLY LOW LEVEL
FLOW TO RETURN. TEMPS THROUGH THE EXTENDED ARE LOOKING SEASONAL.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
01
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
622 AM CDT FRI MAY 31 2013
.UPDATE...FOR 12Z AVIATION DISCUSSION.
&&
.AVIATION...12Z AVIATION DISCUSSION.
UNCERTAINTIES...HOW FAR WILL MOISTURE ASSOCIATED WITH DYING MCS MAKE IT INTO
MID STATE AND ASSOCIATED SHWR/TSTMS CHANCES. WILL GO WITH VFR CEILINGS THRU
01/12Z...WITH MAIN IMPACT OF SHWRS/TSTMS ACROSS CKV FROM 31/13Z-31/18Z. QUESTION
HOW FAR EWD MCS INFLUENCES WILL EXTEND...AND THUS WILL CONTINUE WITH ONLY
VCTS REMARKS AT BOTH BNA/CSV. EXPECT SOME ERROSION OF VFR CU CEILINGS AFTER
31/18Z W TO 31/22Z E...WITH AN INCREASE IN MOISTURE AHEAD OF UPPER LEVEL
DISTURBANCE ALLOWING FOR SCT/BKN STCU/AC/CI FROM 01/07Z W TO 01/12Z E. PER SFC
PRESSURE GRADIENT...EXPECT GUST TO 20KTS POSSIBLE 31/13Z W TO 01/03Z E.
&&
.PREV DISCUSSION.../ISSUED 554 AM CDT FRI MAY 31 2013/
UPDATE...
LATEST MODELS INDICATING THAT THE DEEPER MOISTURE WILL INDEED
TRANSITION NORTHEASTWARD ACROSS OUR NORTHWESTERN COUNTIES LATER
THIS MORNING. THIS IS FURTHER CONFIRMED BY RECENT RADAR TRENDS AND
TODAY`S HRRR DATA. WILL GO AHEAD AND INCREASE POPS...PRIMARILY
ACROSS WESTERN AND NORTH CENTRAL ZONES.
PREV DISCUSSION... /ISSUED 333 AM CDT FRI MAY 31 2013/
MAIN COLD FRONTAL BOUNDARY IS STILL LOCATED WELL WEST OF TN AND
RESIDES ALONG THE CENTRAL PLAINS. MAIN FOCUS OF CONVECTION THIS
MORNING IS IN ASSOCIATION WITH A SERIES OF MCS`S FROM AR NE THROUGH
NRN IN. 850MB JET IS COMBINING WITH STRONG IMPULSES WITHIN THE SWLY
FLOW ALOFT TO KEEP THIS CONVECTION GOING OVERNIGHT. MODELS DO SHOW
AN EASTWARD MIGRATION OF THESE DYNAMICS FOR TODAY. ALTHOUGH THE
DYNAMICS WILL WEAKEN...HRRR DOES SUPPORT CONVECTION MOVING INTO OUR
NORTHWESTERN ZONES LATER THIS MORNING. CURRENTLY...CONVECTION HAS
MOVED INTO FAR WESTERN TN. THUS...POPS OF 30-50 PERCENT FOR
TODAY...GREATEST POPS WEST.
TONIGHT...COLD FRONT GETS A LITTLE CLOSER BUT AGAIN...THE BETTER MCS
COMPLEXES WILL REMAIN NW OF MIDDLE TN. MAY SEE SOME CONVECTIVE
ENCROACHMENT ON OUR FAR NW AREAS LATE TONIGHT AND WILL THUS INCLUDE
40 POPS NW...20 POPS ELSEWHERE.
ON SATURDAY...COLD FRONT WILL APPROACH THE MS RIVER BY LATE
AFTERNOON. MOISTURE AND INSTABILITY WILL BE RAMPING UP ACROSS THE
MID STATE AND POPS OF 30-60 PERCENT WILL BE ON ORDER. THE OVERALL
SYSTEM WILL BECOME MORE SFC ORIENTED AS THE MID AND UPPER JETS
REMAIN NORTH OF TN. NEVERTHELESS..FRONTAL IMPACTS WILL BE
FELT...ESPECIALLY ON SATURDAY NIGHT AND SUNDAY...WITH THE FROPA
OCCURRING ON SUNDAY.
AS FOR SEVERE CHANCES...ELEVATED CAPES WILL CONVERGE WITH FRONTAL
BASED SFC FORCING TO PROMOTE A SLIGHT RISK OF SEVERE ON SATURDAY AFT
AND EVENING...MAINLY WESTERN ZONES. THEN...AS THE FRONT MOVES
THROUGH ON SUNDAY...SEVERE WEATHER WILL BE POSSIBLE ACROSS EASTERN
ZONES DURING THE DAY. NOT REALLY SEEING MUCH OVERNIGHT SEVER WEATHER
POTENTIAL...UPPER DYNAMICS ARE LOOKING WEAKER AND 850 MB FLOW IS NOT
OVERLY IMPRESSIVE. DESCENT QPF TOTALS FOR THE SAT NT
OVERNIGHT...BUT OVERALL STORM DEINTENSIFICATION MAY BE THE RULE AS
WE LOSE THE DAYTIME HEATING AND THE ELEVATED DYNAMICS ARE NOT
OVERLY IMPRESSIVE.
AS FOR HEAVY RAINFALL POTENTIAL...LOOKS LIKE STORM TOTAL QPF OF UP
TO 2 INCHES IS POSSIBLE NW AREAS...1 TO 2 INCHES ELSEWHERE. THIS IS
NOT ESF WORTHY...BUT IT WILL CONTINUE TO BE MONITORED.
TEMPERATURE WISE...NO BIG DEVIATIONS VERSUS THE MAV.
IN THE EXT FCST...BOUNDARY MOVES THROUGH WITH DRIER POP FREE WEATHER
FOR THE EARLY HALF OF THE WORK WEEK. MOISTURE...HOWEVER...WILL
RETURN AS THE SFC HIGH SHIFTS EAST AND ALLOWS A SOUTHERLY LOW LEVEL
FLOW TO RETURN. TEMPS THROUGH THE EXTENDED ARE LOOKING SEASONAL.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
554 AM CDT FRI MAY 31 2013
.UPDATE...
LATEST MODELS INDICATING THAT THE DEEPER MOISTURE WILL INDEED
TRANSITION NORTHEASTWARD ACROSS OUR NORTHWESTERN COUNTIES LATER
THIS MORNING. THIS IS FURTHER CONFIRMED BY RECENT RADAR TRENDS AND
TODAY`S HRRR DATA. WILL GO AHEAD AND INCREASE POPS...PRIMARILY
ACROSS WESTERN AND NORTH CENTRAL ZONES.
&&
.PREV DISCUSSION... /ISSUED 333 AM CDT FRI MAY 31 2013/
MAIN COLD FRONTAL BOUNDARY IS STILL LOCATED WELL WEST OF TN AND
RESIDES ALONG THE CENTRAL PLAINS. MAIN FOCUS OF CONVECTION THIS
MORNING IS IN ASSOCIATION WITH A SERIES OF MCS`S FROM AR NE THROUGH
NRN IN. 850MB JET IS COMBINING WITH STRONG IMPULSES WITHIN THE SWLY
FLOW ALOFT TO KEEP THIS CONVECTION GOING OVERNIGHT. MODELS DO SHOW
AN EASTWARD MIGRATION OF THESE DYNAMICS FOR TODAY. ALTHOUGH THE
DYNAMICS WILL WEAKEN...HRRR DOES SUPPORT CONVECTION MOVING INTO OUR
NORTHWESTERN ZONES LATER THIS MORNING. CURRENTLY...CONVECTION HAS
MOVED INTO FAR WESTERN TN. THUS...POPS OF 30-50 PERCENT FOR
TODAY...GREATEST POPS WEST.
TONIGHT...COLD FRONT GETS A LITTLE CLOSER BUT AGAIN...THE BETTER MCS
COMPLEXES WILL REMAIN NW OF MIDDLE TN. MAY SEE SOME CONVECTIVE
ENCROACHMENT ON OUR FAR NW AREAS LATE TONIGHT AND WILL THUS INCLUDE
40 POPS NW...20 POPS ELSEWHERE.
ON SATURDAY...COLD FRONT WILL APPROACH THE MS RIVER BY LATE
AFTERNOON. MOISTURE AND INSTABILITY WILL BE RAMPING UP ACROSS THE
MID STATE AND POPS OF 30-60 PERCENT WILL BE ON ORDER. THE OVERALL
SYSTEM WILL BECOME MORE SFC ORIENTED AS THE MID AND UPPER JETS
REMAIN NORTH OF TN. NEVERTHELESS..FRONTAL IMPACTS WILL BE
FELT...ESPECIALLY ON SATURDAY NIGHT AND SUNDAY...WITH THE FROPA
OCCURRING ON SUNDAY.
AS FOR SEVERE CHANCES...ELEVATED CAPES WILL CONVERGE WITH FRONTAL
BASED SFC FORCING TO PROMOTE A SLIGHT RISK OF SEVERE ON SATURDAY AFT
AND EVENING...MAINLY WESTERN ZONES. THEN...AS THE FRONT MOVES
THROUGH ON SUNDAY...SEVERE WEATHER WILL BE POSSIBLE ACROSS EASTERN
ZONES DURING THE DAY. NOT REALLY SEEING MUCH OVERNIGHT SEVER WEATHER
POTENTIAL...UPPER DYNAMICS ARE LOOKING WEAKER AND 850 MB FLOW IS NOT
OVERLY IMPRESSIVE. DESCENT QPF TOTALS FOR THE SAT NT
OVERNIGHT...BUT OVERALL STORM DEINTENSIFICATION MAY BE THE RULE AS
WE LOSE THE DAYTIME HEATING AND THE ELEVATED DYNAMICS ARE NOT
OVERLY IMPRESSIVE.
AS FOR HEAVY RAINFALL POTENTIAL...LOOKS LIKE STORM TOTAL QPF OF UP
TO 2 INCHES IS POSSIBLE NW AREAS...1 TO 2 INCHES ELSEWHERE. THIS IS
NOT ESF WORTHY...BUT IT WILL CONTINUE TO BE MONITORED.
TEMPERATURE WISE...NO BIG DEVIATIONS VERSUS THE MAV.
IN THE EXT FCST...BOUNDARY MOVES THROUGH WITH DRIER POP FREE WEATHER
FOR THE EARLY HALF OF THE WORK WEEK. MOISTURE...HOWEVER...WILL
RETURN AS THE SFC HIGH SHIFTS EAST AND ALLOWS A SOUTHERLY LOW LEVEL
FLOW TO RETURN. TEMPS THROUGH THE EXTENDED ARE LOOKING SEASONAL.
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 87 70 88 70 / 40 20 40 60
CLARKSVILLE 86 69 86 68 / 50 40 60 80
CROSSVILLE 81 66 82 66 / 30 10 40 40
COLUMBIA 87 70 88 70 / 30 10 40 60
LAWRENCEBURG 86 69 87 69 / 30 10 40 60
WAVERLY 87 70 87 68 / 40 40 60 80
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1015 AM EDT FRI MAY 31 2013
.SYNOPSIS...
HIGH PRESSURE WILL KEEP US IN THE SUMMER LIKE HEAT INTO
SATURDAY. BY THE END OF THE WEEKEND INTO EARLY NEXT WEEK A
FRONTAL SYSTEM WILL ARRIVE WITH INCREASING CHANCES OF
SHOWERS AND STORMS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 925 AM EDT FRIDAY...
OVERALL PERSISTENCE FORECAST IN STORE THRU THIS AFTERNOON WITH
LITTLE CHANGE SEEN ALOFT OFF MORNING SOUNDINGS WHILE PWATS HAVE
INCREASED A BIT FROM YDA. HOWEVER FOCUS REMAINS LIMITED GIVEN DRY
AIR LINGERING ALOFT UNDER THE CONTINUED 5H RIDGING AND SURFACE
HIGH PRESSURE EXTENDING FROM OFFSHORE. HEIGHTS DO FALL A LITTLE
THIS AFTERNOON AS MODIFIED CAPES BOUNCE ABOVE 1500-2000 J/KG AND
WEAK CONVERGENCE DEVELOPS FAR NW PER SOUTH/SE FLOW. ALSO SOME WEAK
MCON LOOKS TO TAKE SHAPE IN THE MORE MOIST LOW LEVEL WEAK RETURN
FLOW ACROSS THE FAR SOUTH BUT IFFY WITH COVERAGE AND IF ANY SHRA
WILL MAKE IT THIS FAR NORTH. OTRW LATEST HRRR AND RNK-WRF SHOWING
VERY ISOLATED COVERAGE MAINLY FAR NW LATER THIS AFTERNOON SO
KEEPING A 20/30 POP MENTION GOING DOWN ALONG THE WESTERN SPINE OF
THE APPS AND LITTLE ELSW. 12Z THICKNESS CLOSE TO THAT OF THU AND
GIVEN SIMILAR 85H TEMPS BUMPED UP HIGHS A FEW DEGREES WITH VALUES
AGAIN APPROACHING 90 SE.
TONIGHT...CONVECTION WEAKENS/ENDS ACROSS THE WEST AND WILL SEE
ANOTHER RIDE UP CLOSE TO THE SRN BLUE RIDGE AND ADJACENT AREAS OF
SOME LOWER CLOUDS BUT OVERALL PARTLY CLOUDY. MUGGY LOWS IN THE
UPPER 50S TO MID 60S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
AS OF 300 AM EDT THURSDAY...
BERMUDA RIDGING ACROSS THE SOUTHEAST AND MID ATLANTIC STATES WILL BE
STRONG ON FRIDAY...RESULTING IN ONLY AN ISOLATED CHANCE OF SHOWERS
AND THUNDERSTORMS WITH AFTERNOON HEATING...AND HIGHS REACHING THE
MID TO UPPER 80S MOST LOCATIONS. HOWEVER...WILL SEE A TREND WHERE
THE RIDGING PATTERN WILL GRADUALLY BREAK DOWN DURING THE WEEKEND AS
AN UPPER TROUGH SWINGS FROM THE NORTHERN PLAINS ON SATURDAY OVER THE
GREAT LAKES BY SUNDAY. AS SUCH...SHOWER AND THUNDERSTORM ACTIVITY
WILL BE WIDELY SCATTERED ACROSS THE MOUNTAINS ON SATURDAY...AND THEN
RATHER WIDESPREAD ACROSS THE MOUNTAINS ON SUNDAY AS A COLD FRONT
ASSOCIATED WITH THE UPPER TROUGH APPROACHES FROM THE WEST. THE COLD
FRONT IS EXPECTED TO PASS SLOWLY ACROSS OUR AREA SUNDAY NIGHT INTO
MONDAY.
DESPITE THE BREAKDOWN IN RIDGING...AFTERNOON TEMPERATURES FOR
SATURDAY AND SUNDAY WILL NOT FALL OFF MUCH AT ALL...RANGING FROM THE
MID 80S WEST TO NEAR 90 EAST FOR HIGHS BOTH DAYS. OVERNIGHT
TEMPERATURES WILL ALSO REMAIN WARM AND MUGGY THANKS TO THE MOIST
SOUTHWESTERLY WIND FLOW DURING THE PERIOD...WITH LOWS FALLING INTO
THE 60S MOST LOCATIONS.
WILL ALSO KEEP AN EYE OUT FOR PATCHY FOG EARLY EACH MORNING...MAINLY
IN THE RIVER VALLEYS AND ACROSS LOCATIONS WHICH RECEIVED SIGNIFICANT
RAINFALL FROM SHOWER AND THUNDERSTORM ACTIVITY THE EVENING BEFORE.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 AM EDT THURSDAY...
BLOCKING PATTERN CONTINUES TO RELAX ON MONDAY AS MID CONUS TROUGH
LIFTS NORTHEAST THROUGH THE GREAT LAKES AND INTO NEW ENGLAND. THIS
WILL ALLOW THE ACCOMPANYING SURFACE FRONT TO MOVE EAST CROSSING THE
MID ATLANTIC REGION. THE ECMWF IS THE MOST PROGRESSIVE MODEL WITH
THIS FEATURE...MOVING IT THROUGH OUR AREA AND OFF THE MID ATLANTIC
COAST MONDAY NIGHT. THE GFS IS ABOUT 12 HOURS SLOWER. PREFER THE
MORE PROGRESSIVE GUIDANCE WITH THE SURFACE FRONT WELL EAST OF THE
FORECAST AREA BY DAYBREAK TUESDAY. FOLLOWING THIS GUIDANCE...SHOWERS
AND STORMS ARE EXPECTED TO BECOME MORE NUMEROUS...MORE SO FOR MONDAY
AS THE ACTUAL SURFACE FRONT CROSSES THE MID ATLANTIC REGION.
WITH THE FRONTAL PASSAGE PROGGED FOR MONDAY...LOOKING AT RETURN OF
DRY WEATHER FOR TUESDAY AND THE MIDDLE OF NEXT WEEK...HIGH PRESSURE
SLIDING EAST ACROSS THE GREAT LAKES AND PROVIDING US WITH A SOMEWHAT
COOLER NORTHERLY FLOW. AIRMASS BEHIND THIS FRONT IS NOT NEARLY AS
COOL AS WHAT TRANSPIRED OVER THE MEMORIAL DAY HOLIDAY WEEKEND...85H
TEMPS ONLY DROPPING TO AROUND +8 TO +10 DEG C.
RETURN FLOW SHOULD DEVELOP FOR THE LATTER HALF OF NEXT WEEK...WINDS
BECOMING SOUTHERLY ON THE BACK SIDE OF THE SURFACE
HIGH...TEMPERATURES WARMING.
THIS WEEKEND IS THE OFFICIAL START OF THE 2013 HURRICANE SEASON.
EXPECTATIONS ARE FOR AN ABOVE NORMAL SEASON. THIS IS BASED ON SEA
SURFACE TEMPERATURES THAT ARE WARMER THAN NORMAL IN THE TROPICAL
ATLANTIC AND AN ENSO NEUTRAL PATTERN IN THE PACIFIC. THESE FACTORS,
ALONG WITH OTHER HEMISPHERIC DECADAL AND INTER-SEASONAL OSCILLATIONS
ARE SIGNALS FOR AN ACTIVE STORM SEASON. LONG TRACKING STORMS WILL BE
MORE COMMON THIS YEAR THAN IN 2012 FAVORING FORMATION IN THE
INTERTROPICAL CONVERGENCE ZONE. AS SUCH...THE RISK FOR CAT 3, CAT 4,
AND CAT 5 HURRICANES IS GREATER THIS YEAR THAN IN PREVIOUS YEARS.
&&
.AVIATION /13Z FRIDAY THROUGH TUESDAY/...
AS OF 710 AM EDT FRIDAY...
IFR FOG AT LWB EARLY THIS MORNING WILL BE GONE BY 14Z WITH VFR
CONDITIONS PREVAILING THE REST OF THE DAY AT ALL TAF SITES.
SOME CU/TCU SHOULD FORM THIS AFTERNOON ESPECIALLY ACROSS THE
MOUNTAINS. A FEW COULD FORM INTO THUNDERSTORMS ALTHOUGH COVERAGE
STILL LOOKS TO BE SPARSE. BLF/LWB STAND THE BEST CHANCE BUT GIVEN
NOT BIG A CHANCE...NO MENTION IN THE TAFS.
QUESTION TONIGHT WILL BE THE SOUTHERLY FETCH OF MOISTURE THAT HAS
BEEN SPREADING SOME LOWER CIGS INTO THE NC MOUNTAINS EARLY THIS
MORNING AND IF THEY WILL REACH ACROSS INTO OUR AREA LATE TONIGHT.
THE NAM SEEMS TO INDICATE THAT BCB/DAN COULD SEE SOME CIGS
SCRAPING THE MVFR THRESHOLD LATE TONIGHT...BUT WILL LEAVE IT
SCATTERED AT 3KFT AT BCB AND BKN040 AT DAN. FOG WILL AGAIN BE AN
ISSUE AT LWB AND PERHAPS BCB IF THE LOWER CLOUDS TO DO NOT MOVE
IN.
MOISTURE INCREASES AHEAD OF A FRONT BY LATER SUNDAY AND INTO
EARLY NEXT WEEK. A GOOD CHANCE OF SHOWERS AND STORMS WILL BRING
SOME OCCASIONAL SUB VFR CONDITIONS TO THE REGION DURING THIS TIME.
FRONT PUSHES SLOWLY SE BY TUESDAY ALLOWING A RETURN TO MOSTLY VFR
BY THEN.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/WP
NEAR TERM...JH/WP
SHORT TERM...NF
LONG TERM...AMS/NF
AVIATION...JH/KM/WP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
703 AM CDT FRI MAY 31 2013
.UPDATE...THIS MORNING
ISSUED AT 700 AM CDT FRI MAY 31 2013
EARLY THIS MORNING...SHOWERS WILL CONTINUE TO BE FOUND IN WISCONSIN
NORTH OF THE INTERSTATE 90 CORRIDOR. THESE SHOWERS ARE DEVELOPING
ON NOSE OF THE DRY SLOT...AND SHOULD BE NORTHEAST OF THE AREA BY
31.15Z.
FOR MID TO LATE MORNING...THE MAIN CONCERN IS WHERE THE MESOSCALE
CONVECTIVE COMPLEX OVER MISSOURI WILL TRACK THIS MORNING. THE
LATEST RAP CONTINUES TO BRING THIS SYSTEM NORTHEAST INTO THE AREA.
MEANWHILE THE HRRR SHOWS THAT THIS SYSTEM WILL REMAIN SOUTH OF THE
AREA. LOOKING AT THE MEAN WIND VECTORS OFF OF THE RADAR...THE HRRR
MAKES MUCH MORE SENSE...SO TRENDED THE FORECAST THAT WAY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 329 AM CDT FRI MAY 31 2013
TWO AREAS OF CONVECTION THIS MORNING THAT MAY IMPACT THE AREA. THE
FIRST IS PRIMARILY ALREADY OFF THE NORTHWEST OF THE AREA FROM
NORTHWEST MINNESOTA INTO WESTERN WISCONSIN. THIS AREA IS MOVING
OFF TO THE NORTH/NORTHEAST AND IS NOT EXPECTED TO IMPACT THE
FORECAST AREA. THE OTHER AREA OF CONVECTION IS OVER NORTHWEST
MISSOURI AND IS MOVING TO THE NORTHEAST. THE HRRR SEEMS TO BE
HANDLING THIS THE BEST...BUT IS CONSIDERABLY TOO SLOW WITH IT. THE
TREND FROM THE 31.04Z AND 31.05Z RUNS IS FOR THIS AREA TO MOVE
NORTHEAST ACROSS EASTERN IOWA INTO NORTHERN ILLINOIS AND FOR THE
MOST PART MISSING THE AREA TO THE SOUTH. THE 31.00Z ECMWF ALSO
SHOWS THIS AREA COMING OUT OF MISSOURI BUT TAKES IT FARTHER TO THE
NORTHWEST IMPACTING THE SOUTHERN AND EASTERN AREAS FROM LATE
MORNING THROUGH THE AFTERNOON. THE PREVIOUS FORECAST WAS TRENDED
TOWARD THE POSSIBILITY OF THIS CONVECTION COMING INTO THE AREA SO
HAVE MAINTAINED THESE TRENDS BUT LIMITED THE HIGHER RAIN CHANCES
TO THE SOUTHEAST SECTIONS OF THE FORECAST AREA. BY LATE IN THE
AFTERNOON AND INTO THE EVENING...ALL THE MODELS ARE SHOWING WHAT
LOOKS LIKE A DRY LINE/WIND SHIFT DEVELOPING AHEAD OF THE SURFACE
LOW AND MOVING EAST TOWARD THE AREA. THERE SHOULD BE ANOTHER SHORT
WAVE TROUGH ROUNDING THE UPPER LEVEL LOW TO PROVIDE DYNAMIC LIFT
OVER THIS DRY LINE/WIND SHIFT. BOTH THE 31.00Z NAM AND GFS SHOW A
JET CORE ALSO COMING AROUND THE UPPER LEVEL LOW WITH THE LEFT EXIT
REGION COMING OVER THE AREA TO ADD SOME AGEOSTROPHIC MOTIONS TO THE
FORCING FROM THE SHORT WAVE TROUGH. THIS SHOULD BE ENOUGH FORCING
TO CAUSE A LINE OF CONVECTION TO DEVELOP ALONG THIS DRY LINE AND
THEN WORK RAPIDLY EAST ACROSS THE AREA DURING THE EVENING. SOME
POTENTIAL FOR SEVERE TODAY...BUT THIS IS DEFINITELY NOT AS HIGH AS
THE PAST COUPLE OF DAYS. ML CAPES OF 1000 TO POSSIBLY AS MUCH AS
2000 J/KG SHOULD DEVELOP TODAY AHEAD OF THE DRY LINE. THE BEST
0-6KM SHEAR WILL BE WELL OUT AHEAD OF THE DRY LINE AND WILL LINE
UP BETTER WITH THE EXPECTED CONVECTION TO COME NORTHEAST OUT OF
MISSOURI. HOWEVER...THE 0-3 KM SHEAR SHOULD BE AROUND 30 KNOTS
AHEAD OF THE DRY LINE SO THE POTENTIAL FOR STORMS THIS AFTERNOON
AND EVENING TO PRODUCE DAMAGING WINDS AND HAIL. ALL THE ACTIVITY
SHOULD QUICKLY DIE DOWN AFTER MIDNIGHT AS IT MOVES OFF TO THE EAST
OF THE AREA. BOTH THE NAM AND GFS SHOW THE PRECIPITABLE WATERS
LOWERING DURING THE DAY AS DRIER AIR WRAPS IN FROM THE WEST. WHILE
ANY THUNDERSTORMS MAY PRODUCE SOME LOCALLY HEAVY RAIN...FEEL THAT
THE POTENTIAL FOR WIDESPREAD HEAVY RAINS TO PRODUCE FLASH FLOODING
IS NOT THERE TO SUPPORT THE NEED FOR ANOTHER FLASH FLOOD WATCH.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 329 AM CDT FRI MAY 31 2013
AT LONG LAST...THIS STUBBORN SYSTEM WILL BEGIN TO MAKE A MOVE TO
THE EAST SATURDAY. AS IT DOES...THE SURFACE LOW WILL MOVE FROM
CENTRAL MINNESOTA INTO NORTHERN WISCONSIN AS THE UPPER LEVEL LOW
BECOMES AN OPEN WAVE. THE LAST SHORT WAVE TROUGH WITH THIS SYSTEM
IS EXPECTED TO BE MOVING ACROSS THE AREA AND BE PRODUCING AROUND 8
PVU/S OF VORTICITY ADVECTION IN THE 500-300 MB LAYER. THIS FORCING
FROM THE WAVE COMBINED WITH BEING IN THE DEFORMATION AREA OF THE
SURFACE LOW SHOULD BE ENOUGH TO GENERATE SHOWERS ACROSS MUCH OF
THE AREA. MU CAPES SHOULD BE AROUND 200-300 J/KG IN THE AFTERNOON
WHICH WILL BE GOOD ENOUGH TO PRODUCE SOME ISOLATED THUNDER. THE
REMAINING SHOWERS SHOULD THEN MOVE OFF TO THE EAST SATURDAY NIGHT
WITH SUNDAY BEING THE FIRST DAY IN ABOUT A WEEK WITH NO CHANCE OF
RAIN. MONDAY ALSO LOOKS TO BE DRY WITH HIGH PRESSURE OVER THE AREA
BUT THEN THE RAIN CHANCES START TO RETURN FOR MONDAY NIGHT. THE
31.00Z GFS...GEM AND ECMWF ALL SHOW ANOTHER CLOSED LOW MOVING
TOWARD THE AREA FROM THE PACIFIC NORTHWEST. PLENTY OF DIFFERENCES
THOUGH ON HOW FAST THIS SYSTEM WILL START TO IMPACT THE AREA. THE
OPERATIONAL GFS IS THE FASTEST BRINGING THIS SYSTEM IN...EVEN
FASTER THAN ITS ENSEMBLE MEAN WHILE THE ECMWF IS THE SLOWEST. THIS
LOOKS TO BE ANOTHER SLOW MOVING SYSTEM KEEPING RAIN CHANCES IN THE
FORECAST FOR THE REMAINDER OF THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 700 AM CDT FRI MAY 31 2013
IFR TO MVFR CEILINGS WILL GRADUALLY BECOME VFR BY 31.15Z. SHOWERS
AND THUNDERSTORMS WILL DEVELOP AHEAD OF A COLD FRONT LATE THIS
AFTERNOON AND EVENING. THESE THUNDERSTORMS WILL AFFECT KRST
BETWEEN 31.22Z AND 01.04Z...AND KLSE BETWEEN 01.00Z AND 01.06Z. A
FEW OF THESE THUNDERSTORMS MAY BECOME SEVERE. THE MAIN THREATS
WILL BE LARGE HAIL AND DAMAGING WINDS. THERE MAY BE EVEN AN
ISOLATED TORNADO. ONCE THE FRONT CLEARS THE AREA CEILINGS WILL
CLIMB TO AROUND 10K FEET.
&&
.HYDROLOGY...
ISSUED AT 329 AM CDT FRI MAY 31 2013
TURKEY RIVER...
WITH THURSDAY BEING MUCH DRIER THAN EXPECTED IN NORTHEAST IOWA...THE
TURKEY RIVER IS COMING IN MUCH LOWER THAN ORIGINALLY ANTICIPATED.
ELKADER IS EXPECTED TO CREST AROUND 16.5 FEET. THIS IS ABOUT 2 FEET
LOWER THAN THE PREVIOUS FORECAST. THIS IN TURN WILL RESULT IN A MUCH
LOWER CREST FOR GARBER. THE RIVER HAS ALREADY CRESTED AROUND
22.1 FEET. IT SHOULD REMAIN AROUND THIS LEVEL THROUGH MUCH OF TODAY
AND THEN BEGIN A SLOW FALL.
UPPER IOWA...
DORCHESTER HAS FLATTENED OUT AROUND 13.4 FEET. WITH DECORAH
CONTINUING TO RISE UPSTREAM...EXPECT THAT DORCHESTER WILL ONCE AGAIN
START TO RISE THIS MORNING. CONSIDERING THE RAINFALL ACROSS THIS
BASIN ON THURSDAY STILL NOT QUITE SURE WHETHER THE CREST LATER THIS
AFTERNOON WILL BE ABOUT A HALF FEET /15.5 FEET/ HIGHER THAN ITS
PREVIOUS CREST OF 15 FEET ON THURSDAY MORNING. AM MORE INCLINED THAT
IT WILL COME IN WITH A SIMILAR AS THURSDAY MORNING.
KICKAPOO RIVER...
THE UPPER REACHES OF THE KICKAPOO HAVE ALREADY CRESTED AND STARTED
TO FALL RAPIDLY...THEREFORE...LA FARGE WILL BE ADJUSTED TO CREST
LOWER THAN EXPECTED /STILL BELOW FLOOD STAGE/
BLACK RIVER...
BLACK RIVER FALLS IS CONTINUING TO RISE RATHER RAPIDLY THIS MORNING.
LOOKING AT THE WATER UPSTREAM...THE NORTH CENTRAL RIVER FORECAST
CENTER IS EXPECTING IT TO NOW CREST AROUND 49.3 FEET LATER TODAY.
TREMPEALEAU RIVER...
DUE TO THE BROADER EXPANSE NEAR DODGE...EXPECT TO SEE A SLOW AND
STEADY RISE INTO THE WEEKEND. IT STILL LOOKS LIKE IT WILL CREST ON
SUNDAY AROUND 9.6 FEET.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...BOYNE
SHORT TERM...04
LONG TERM...04
AVIATION...BOYNE
HYDROLOGY...BOYNE
AREA FORECAST DISCUSSION
NWS TUCSON AZ
930 AM MST FRI MAY 31 2013
.SYNOPSIS...HIGH PRESSURE ALOFT WILL BRING DRY CONDITIONS WITH WELL
ABOVE NORMAL TEMPERATURES THROUGH THE MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...THE SHALLOW MOISTURE THAT WAS AROUND YESTERDAY MORNING
MADE A RETURN LAST NIGHT INTO THIS MORNING...WITH SURFACE DEWPOINTS
HIGHER THEN YESTERDAY. ALMOST MONSOON LIKE FROM TUCSON WEST. THIS
MOISTURE ALSO BROUGHT A HAZY SKY TO THE AREA THIS MORNING ALONG WITH
WARMER OVERNIGHT LOW TEMPERATURES.
THE MAIN FORECAST CHALLENGE OF THE DAY SURROUNDS THE THIRD ATTEMPT
THIS MONTH FOR HITTING 100 DEGREES AT THE TUCSON AIRPORT FOR THE
FIRST TIME IN 2013. 850-700 MB THICKNESS VALUES ON THE MORNING
SOUNDING WERE UP VERSUS YESTERDAY AND IF YOU ADD THAT INCREASE TO
YESTERDAY AFTERNOON 850-700 MB TKNS VALUE...99 IS PRETTY CERTAIN
WITH AN OUTSIDE CHANCE FOR 100. BASED ON 850-700 MB THICKNESS VALUES
FOR THIS AFTERNOON 12Z NAM/12Z GFS GOING 98 OR 99...00Z ECMWF/12Z
UKMET/12Z CANADIAN INDICATING 100. 14Z HRRR/15Z RAP GOING WITH 99.
HOW MUCH OF THIS SHALLOW MOISTURE MIXES OUT WILL ALSO BE A KEY
TODAY. OTHERWISE ACROSS SE AZ...HIGHS WILL BE 1-4 DEGREES ABOVE
NORMAL. MAY SEE SOME FLAT CU AROUND THIS AFTERNOON ESPECIALLY EAST
OF TUCSON AND UP IN THE WHITES.
&&
.AVIATION...SKC THRU SATURDAY MORNING OR 01/15Z. SURFACE WIND
THIS AFTERNOON AND EARLY THIS EVENING WLY/NWLY 10-18 KTS WITH GUSTS
OF 20-25 KTS... STRONGEST WIND EAST OF KTUS. OTHERWISE...SURFACE
WIND LESS THAN 10 KTS. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
&&
.FIRE WEATHER...DRY CONDITIONS WITH WELL ABOVE NORMAL DAYTIME
TEMPERATURES WILL PREVAIL INTO THE MIDDLE OF NEXT WEEK. DAYTIME
MINIMUM RELATIVE HUMIDITIES WILL GENERALLY BE IN THE SINGLE DIGITS
TO LOWER TEENS WITH FAIR TO POOR OVERNIGHT RECOVERIES. NORMAL
DIURNAL WIND TRENDS WILL OCCUR...WITH OCCASIONAL GUSTS DURING THE
AFTERNOON HOURS DUE TO STRONG DAYTIME HEATING.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
533 PM CDT FRI MAY 31 2013
.DISCUSSION...
336 PM CDT
THOUGHTS FROM THE EARLIER MESO DISCUSSION ARE STILL VALID AND HAVE
BEEN BOLSTERED BY THE SPREAD OF SHOWERS WITH ISOLATED TSRA INTO THE
FCST AREA THIS AFTERNOON WITH LITTLE ADDITIONAL DEVELOPMENT DIRECTLY
WEST OVER IOWA SO FAR. 0-6 KM BULK SHEAR CONTINUES TO BE MARGINAL
OVER MOST OF THE LOCAL REGION BUT IS BUILDING TOWARD 40 KTS IN THE
AREA OF APPROACHING CONVECTION TO OUR SOUTHWEST UNDER THE LEADING
EDGE OF AN UPPER LEVEL JET. A FEW STORMS COULD BECOME ORGANIZED IN
SOUTHERN PORTIONS OF THE CWA...THOUGH THE SEVERE RISK OVERALL
APPEARS TO BE MARGINAL. TRENDS FOR THIS EVENING AND OVERNIGHT
ALSO WOULD CONTINUE TO FAVOR SOUTHERN PORTIONS OF THE CWA FOR THE
HEAVIEST RAINFALL AMOUNTS AND THE CORRESPONDING FLOOD RISK...AND
THIS ALSO IS WHERE THE MOST RAIN HAS FALLEN OVER THE PAST WEEK. FOR
THESE REASONS...AFTER COORDINATION WITH NEIGHBORS...WILL PLAN TO
DROP THE FLOOD WATCH FOR NORTHERN PORTIONS OF THE FORECAST AREA.
ALL OF THIS ACTIVITY IS BEING DRIVEN BY RICH BOUNDARY LAYER GULF
MOISTURE WRAPPING AROUND THE WESTERN SIDE OF A BERMUDA HIGH...AND
AHEAD OF AN APPROACHING FRONTAL ZONE TIED TO LOW PRESSURE OVER THE
DAKOTAS. THIS FRONTAL ZONE PUSHES THROUGH THE AREA SATURDAY NIGHT
AND USHERS IN COOLER AND DRIER AIR FOR THE FIRST HALF OF NEXT WEEK.
UNSETTLED WEATHER WILL PERSIST UNTIL THAT TIME WITH THE FOCUS
GRADUALLY SHIFTING EASTWARD. SHOWER AND THUNDERSTORM FORECAST
TRENDS FOR THIS EVENING AND OVERNIGHT ARE BASED ON CURRENT ACTIVITY
AND THE IDEA OF INCREASING DEVELOPMENT SUPPORTED BY LOW LEVEL
MOISTURE CONVERGENCE BEING DEPICTED IN THE RAP MODEL. IF THESE RAP
FIELDS CONTINUE TO BE VALID TOWARD MORNING...THE NORTHWEST HALF OF
THE AREA WOULD APPEAR TO DRY OUT BY MIDNIGHT AND REMAIN SO INTO THE
MORNING HOURS. THIS TREND ALSO IS SUPPORTED BY THE LATEST
NAM/ECMWF/GFS QPF FIELDS. CHANCES THEN INCREASE AGAIN DURING THE
DAY TOMORROW AHEAD OF THE APPROACHING UPPER LEVEL VORT MAX AND THE
SURFACE FRONTAL ZONE.
AFTER A COOLER AND DRIER END TO THE WEEKEND AND START TO THE WORK
WEEK...THE NEXT UPPER TROUGH AND SFC LOW BEGIN TO APPROACH THE
AREA TOWARD THE MIDDLE OF NEXT WEEK ALONG THE SIMILAR DAKOTAS TRACK
THAT WE HAVE SEEN WITH THE CURRENT SYSTEM. SFC WINDS TURNING
SOUTHEAST BY WEDNESDAY AND SOUTH BY THURSDAY WOULD ALLOW WARM MOIST
GULF AIR TO START WORKING BACK INTO THE AREA FOR LATE NEXT
WEEK...BUT AT THIS RANGE WILL ONLY PLAN TO CARRY CHANCE POPS.
LENNING
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* WINDS MAY BACK TO SE FOR TIME EARLY THIS EVENING
* CHANCE OF MVFR CIGS DEVELOPING THIS EVENING
* CHANCE OF SHRA/TSRA AGAIN SAT AFTERNOON
IZZI
//DISCUSSION...UPDATED 22Z...
HAVE REMOVED PRECIP FOR TONIGHT WITH AXIS OF MOST ORGANIZED
PRECIPITATION LIKELY TO REMAIN WELL SOUTH OF THE CHGO TERMINALS.
AM CLOSELY WATCHING AREA OF DEVELOPING LOWER END MVFR CIGS OVER
WC IL...IF THIS AREA CONTINUES TO EXPAND MAY NEED TO INTRODUCE
SOME MVFR CIGS LATER THIS EVENING INTO THE OVERNIGHT HOURS.
IZZI
UPDATED 18Z...
THE ACTIVE PERIOD CONTINUES BUT THERE IS VERY HIGH UNCERTAINTY
REGARDING WHERE AND WHEN CONVECTION WILL OCCUR TODAY. TEMPS HAVE
CLIMBED INTO THE 70S WITH DEWPOINTS IN THE 60S WHICH SUGGESTS
FAVORABLE CONDITIONS. A LOW PRESSURE SYSTEM IS OVER SOUTH DAKOTA
AND A LEFT OVER CONVECTIVE SYSTEM IS OVER NE MO/SE IA/W IL. SHOWERS
ARE SLOWLY MOVING NORTHEAST WITH A FEW CONVECTIVE CELLS FORMING OVER
FORD COUNTY IL IN THE LAST FEW MINUTES. EXPECTING THUNDERSTORMS TO
DEVELOP ACROSS NORTH CENTRAL IL AND PUSH EAST THROUGH THE EASTERN
TERMINALS. SINCE THE AXIS OF BEST INSTABILITY IS EAST OF RFD...KEPT
TS OUT OF RFD. THAT BEING SAID RFD MAY SEE A FEW STRAY SHOWERS OVER
THE NEXT FEW HOURS. GUSTY S WINDS ARE EXPECTED BUT MAY SEE A BRIEF
SHIFT TO SSE WINDS BEHIND THE THUNDERSTORMS.
EXPECTING A NARROW WINDOW OF TSRA OF ABOUT AN HOUR...FOLLOWED BY
SHOWERS. THE AREA WILL REMAIN UNSTABLE OVERNIGHT WITH SCATTERED
SHOWERS EXPECTED OVERNIGHT. ANOTHER ROUND OF TSRA AND SHOWERS IS
EXPECTED LATE SATURDAY AFTERNOON/EARLY AS THE LOW PRESSURE SYSTEM
PASSES TO THE NORTH AND ITS COLD FRONT APPROACHES FROM THE WEST.
STRONG S WINDS ARE ONCE AGAIN EXPECTED TOMORROW...BUT GUSTS WILL NOT
BE AS STRONG.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM CONFIDENCE IN WINDS THIS EVENING
* LOW/MEDIUM CONFIDENCE IN CIGS TONIGHT
* LOW CONFIDENCE IN TSRA CHANCES SATURDAY
IZZI
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...CHC OF SHRA DURING THE EVE. MVFR POSSIBLE.
SUNDAY...SLT CHC OF MORNING SHRA.
MONDAY...VFR LIKELY.
TUESDAY...CHC OF MORNING MVFR.
WEDNESDAY & THURSDAY...CHC OF TSRA.
MTF
&&
.MARINE...
222 PM CDT
AN AREA OF LOW PRESSURE THAT HAS PERSISTED OVER THE NORTHERN PLAINS
WILL FINALLY BEGIN TO MOVE EAST TONIGHT...PASSING OVER NORTHERN LAKE
MICHIGAN LATE SATURDAY EVENING WITH A TRAILING COLD FRONT TURNING
MODERATE SOUTHERLY WINDS OF 15 TO 25 KT TO NORTHWESTERLY. MOIST FLOW
AHEAD OF THE FRONT HAS ALREADY LED TO DENSE FOG OVER MUCH OF THE
LAKE WHICH IS EXPECTED TO PERSIST UNTIL THE COLD FRONT PASSES
SATURDAY NIGHT. WINDS SHOULD THEN DIMINISH THROUGH THE DAY SUNDAY AS
HIGH PRESSURE BUILDS IN FROM THE WEST...BECOMING CENTERED OVER LAKE
MICHIGAN ON MONDAY. LOW PRESSURE WILL DEVELOP OVER THE CENTRAL
PLAINS MONDAY...THEN LIFT NORTHEAST TO LAKE MICHIGAN LATE THURSDAY
INTO EARLY FRIDAY.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ021-ILZ022-ILZ023-ILZ032-ILZ033-ILZ039
UNTIL 7 PM SATURDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 7
PM SATURDAY.
LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ868-LMZ870-
LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM SATURDAY.
SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 10 PM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
337 PM CDT FRI MAY 31 2013
.DISCUSSION...
336 PM CDT
THOUGHTS FROM THE EARLIER MESO DISCUSSION ARE STILL VALID AND HAVE
BEEN BOLSTERED BY THE SPREAD OF SHOWERS WITH ISOLATED TSRA INTO THE
FCST AREA THIS AFTERNOON WITH LITTLE ADDITIONAL DEVELOPMENT DIRECTLY
WEST OVER IOWA SO FAR. 0-6 KM BULK SHEAR CONTINUES TO BE MARGINAL
OVER MOST OF THE LOCAL REGION BUT IS BUILDING TOWARD 40 KTS IN THE
AREA OF APPROACHING CONVECTION TO OUR SOUTHWEST UNDER THE LEADING
EDGE OF AN UPPER LEVEL JET. A FEW STORMS COULD BECOME ORGANIZED IN
SOUTHERN PORTIONS OF THE CWA...THOUGH THE SEVERE RISK OVERALL
APPEARS TO BE MARGINAL. TRENDS FOR THIS EVENING AND OVERNIGHT
ALSO WOULD CONTINUE TO FAVOR SOUTHERN PORTIONS OF THE CWA FOR THE
HEAVIEST RAINFALL AMOUNTS AND THE CORRESPONDING FLOOD RISK...AND
THIS ALSO IS WHERE THE MOST RAIN HAS FALLEN OVER THE PAST WEEK. FOR
THESE REASONS...AFTER COORDINATION WITH NEIGHBORS...WILL PLAN TO
DROP THE FLOOD WATCH FOR NORTHERN PORTIONS OF THE FORECAST AREA.
ALL OF THIS ACTIVITY IS BEING DRIVEN BY RICH BOUNDARY LAYER GULF
MOISTURE WRAPPING AROUND THE WESTERN SIDE OF A BERMUDA HIGH...AND
AHEAD OF AN APPROACHING FRONTAL ZONE TIED TO LOW PRESSURE OVER THE
DAKOTAS. THIS FRONTAL ZONE PUSHES THROUGH THE AREA SATURDAY NIGHT
AND USHERS IN COOLER AND DRIER AIR FOR THE FIRST HALF OF NEXT WEEK.
UNSETTLED WEATHER WILL PERSIST UNTIL THAT TIME WITH THE FOCUS
GRADUALLY SHIFTING EASTWARD. SHOWER AND THUNDERSTORM FORECAST
TRENDS FOR THIS EVENING AND OVERNIGHT ARE BASED ON CURRENT ACTIVITY
AND THE IDEA OF INCREASING DEVELOPMENT SUPPORTED BY LOW LEVEL
MOISTURE CONVERGENCE BEING DEPICTED IN THE RAP MODEL. IF THESE RAP
FIELDS CONTINUE TO BE VALID TOWARD MORNING...THE NORTHWEST HALF OF
THE AREA WOULD APPEAR TO DRY OUT BY MIDNIGHT AND REMAIN SO INTO THE
MORNING HOURS. THIS TREND ALSO IS SUPPORTED BY THE LATEST
NAM/ECMWF/GFS QPF FIELDS. CHANCES THEN INCREASE AGAIN DURING THE
DAY TOMORROW AHEAD OF THE APPROACHING UPPER LEVEL VORT MAX AND THE
SURFACE FRONTAL ZONE.
AFTER A COOLER AND DRIER END TO THE WEEKEND AND START TO THE WORK
WEEK...THE NEXT UPPER TROUGH AND SFC LOW BEGIN TO APPROACH THE
AREA TOWARD THE MIDDLE OF NEXT WEEK ALONG THE SIMILAR DAKOTAS TRACK
THAT WE HAVE SEEN WITH THE CURRENT SYSTEM. SFC WINDS TURNING
SOUTHEAST BY WEDNESDAY AND SOUTH BY THURSDAY WOULD ALLOW WARM MOIST
GULF AIR TO START WORKING BACK INTO THE AREA FOR LATE NEXT
WEEK...BUT AT THIS RANGE WILL ONLY PLAN TO CARRY CHANCE POPS.
LENNING
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* GUSTY S WINDS EXPECTED THROUGH THIS AFTN WITH A BRIEF PERIOD OF
SSE WINDS PSBL BEHIND TSRA/SHRA.
* SHRA OR TSRA PSBL THIS AFTN WITH MVFR VSBY PSBL WITH TSRA.
* SCT SHOWERS OVERNIGHT.
* ANOTHER ROUND OF TSRA/SHRA EXPECTED TOMORROW AFTN.
JEE
//DISCUSSION...UPDATED 18Z...
THE ACTIVE PERIOD CONTINUES BUT THERE IS VERY HIGH UNCERTAINTY
REGARDING WHERE AND WHEN CONVECTION WILL OCCUR TODAY. TEMPS HAVE
CLIMBED INTO THE 70S WITH DEWPOINTS IN THE 60S WHICH SUGGESTS
FAVORABLE CONDITIONS. A LOW PRESSURE SYSTEM IS OVER SOUTH DAKOTA
AND A LEFT OVER CONVECTIVE SYSTEM IS OVER NE MO/SE IA/W IL. SHOWERS
ARE SLOWLY MOVING NORTHEAST WITH A FEW CONVECTIVE CELLS FORMING OVER
FORD COUNTY IL IN THE LAST FEW MINUTES. EXPECTING THUNDERSTORMS TO
DEVELOP ACROSS NORTH CENTRAL IL AND PUSH EAST THROUGH THE EASTERN
TERMINALS. SINCE THE AXIS OF BEST INSTABILITY IS EAST OF RFD...KEPT
TS OUT OF RFD. THAT BEING SAID RFD MAY SEE A FEW STRAY SHOWERS OVER
THE NEXT FEW HOURS. GUSTY S WINDS ARE EXPECTED BUT MAY SEE A BRIEF
SHIFT TO SSE WINDS BEHIND THE THUNDERSTORMS.
EXPECTING A NARROW WINDOW OF TSRA OF ABOUT AN HOUR...FOLLOWED BY
SHOWERS. THE AREA WILL REMAIN UNSTABLE OVERNIGHT WITH SCATTERED
SHOWERS EXPECTED OVERNIGHT. ANOTHER ROUND OF TSRA AND SHOWERS IS
EXPECTED LATE SATURDAY AFTERNOON/EARLY AS THE LOW PRESSURE SYSTEM
PASSES TO THE NORTH AND ITS COLD FRONT APPROACHES FROM THE WEST.
STRONG S WINDS ARE ONCE AGAIN EXPECTED TOMORROW...BUT GUSTS WILL NOT
BE AS STRONG.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE IN PRECIP AFFECTING THE TERMINALS.
* LOW CONFIDENCE IN TIMING AND DURATION.
* LOW CONFIDENCE IN SHRA COVERAGE TONIGHT.
* MEDIUM CONFIDENCE IN TIMING OF SHRA/TSRA TOMORROW AFTERNOON.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...CHC OF SHRA DURING THE EVE. MVFR POSSIBLE.
SUNDAY...SLT CHC OF MORNING SHRA.
MONDAY...VFR LIKELY.
TUESDAY...CHC OF MORNING MVFR.
WEDNESDAY & THURSDAY...CHC OF TSRA.
MTF
&&
.MARINE...
222 PM CDT
AN AREA OF LOW PRESSURE THAT HAS PERSISTED OVER THE NORTHERN PLAINS
WILL FINALLY BEGIN TO MOVE EAST TONIGHT...PASSING OVER NORTHERN LAKE
MICHIGAN LATE SATURDAY EVENING WITH A TRAILING COLD FRONT TURNING
MODERATE SOUTHERLY WINDS OF 15 TO 25 KT TO NORTHWESTERLY. MOIST FLOW
AHEAD OF THE FRONT HAS ALREADY LED TO DENSE FOG OVER MUCH OF THE
LAKE WHICH IS EXPECTED TO PERSIST UNTIL THE COLD FRONT PASSES
SATURDAY NIGHT. WINDS SHOULD THEN DIMINISH THROUGH THE DAY SUNDAY AS
HIGH PRESSURE BUILDS IN FROM THE WEST...BECOMING CENTERED OVER LAKE
MICHIGAN ON MONDAY. LOW PRESSURE WILL DEVELOP OVER THE CENTRAL
PLAINS MONDAY...THEN LIFT NORTHEAST TO LAKE MICHIGAN LATE THURSDAY
INTO EARLY FRIDAY.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 7 PM SATURDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 7
PM SATURDAY.
LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ868-LMZ870-
LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM SATURDAY.
SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 7 PM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
257 PM CDT FRI MAY 31 2013
.MESOSCALE DISCUSSION...
INITIAL LOOK AT THE ATMOSPHERE IN PREPARATION OF AFTERNOON/EVENING
CONVECTION. SUPPORT FOR WIDESPREAD SEVERE APPEARS TO BE LESS
PRONOUNCED THAN EARLIER SIGNALS HAD SUGGESTED. A MINIMA OF 0-6KM
BULK SHEAR EXISTS EARLY THIS AFTERNOON ACROSS
NORTHCENTRAL/NORTHEAST ILLINOIS STRETCHING INTO NORTHWEST INDIANA.
ALONG THE WESTERN PERIPHERY OF THIS MINIMA IS AN AXIS OF MUCH
HIGHER SHEAR AROUND 70KTS IN IOWA...TO NEARLY 80KTS STRETCHING
SOUTH INTO CENTRAL MISSOURI. VISIBLE IMAGERY SHOWS CONSIDERABLE
CLOUD COVER...REMNANTS/BLOWOFF OF EARLIER CONVECTION TO THE
SOUTHWEST...LIFTING NORTHEAST ACROSS THE CWFA AT THIS TIME. THIS
WILL INHIBIT SFC CAPE FROM GETTING OUT OF CONTROL THROUGH EARLY
THIS AFTERNOON...AND TOGETHER WITH THE MARGINAL SHEAR WOULD TEND
TO LIMIT THE LOCAL POTENTIAL FOR ORGANIZED CONVECTION OVER THE
NEXT FEW HOURS.
MORNING CONVECTION IN MISSOURI CORRELATED TO AN AXIS OF LOW LEVEL
MOISTURE CONVERGENCE AND A WEAK TROUGH DEPICTED AT 850 MB. LATEST
FIELDS FROM THE RAP MODEL SHOW THIS TROUGH AND THE WESTERN FOCUS
FOR THIS MOISTURE CONVERGENCE EXPANDING OUT OF THE SAINT LOUIS
AREA ACROSS ILLINOIS AND WORKING INTO THE CHICAGO METRO AREA BY
LATE AFTERNOON...22Z TO 00Z...WHILE GRADUALLY BECOMING LESS
FOCUSED. HI-RES GUIDANCE IS SUGGESTING THAT AS THIS CONVECTION
BEGINS TO LIFT THROUGH SW IL...IT WILL EXPAND ALONG A LINE
STRETCHING FROM SAINT LOUIS THROUGH BLOOMINGTON TO KANKAKEE AND
TOWARD MICHIGAN CITY.
A SMALLER AREA OF LATE MORNING AND EARLY AFTERNOON ISOLATED
STORMS OVER IOWA ALSO IS NICELY CORRELATED TO AN AXIS OF MOISTURE
CONVERGENCE IN THE RAP...BUT WAS MUCH LESS PRONOUNCED AND
MIGRATING MORE TO THE NORTH RATHER THAN EAST INTO ILLINOIS. THIS
CONVECTION WAS CLOSER TO THE 500MB VORT MAX AND IN AN AREA OF
ANTICIPATED STEEPENING LAPSE RATES THROUGHOUT THE AFTN. AS THE
TROUGH AXIS SLOWLY SLIDES EAST...SOME OF THIS MAY PUSH INTO
NORTHWEST IL BUT MAY NOT HAVE THE LONGEVITY TO CONTINUE ACROSS
NORTHCENTRAL/NORTHEAST IL.
BEACHLER/LENNING
&&
.DISCUSSION...
328 AM...MAIN FORECAST CONCERN AND CHALLENGE REMAINS CONVECTIVE
TRENDS/TIMING THROUGH SATURDAY EVENING ALONG WITH POTENTIAL FOR
SEVERE WEATHER AND HEAVY RAIN/FLOODING.
WAVE OF SHOWERS WITH SOME EMBEDDED THUNDER WILL CONTINUE LIFTING
NORTHEAST AWAY FROM THE AREA EARLY THIS MORNING WITH SUBSIDENCE
INTO THE MID MORNING HOURS EXPECTED TO BRING SEVERAL HOURS OF DRY
WEATHER. ATTENTION THEN SHIFTS TO CONVECTION OVER NORTHEAST
KANSAS/NORTHWEST MISSOURI. MOST RECENT HRRR/RAP GUIDANCE SEEMS IN
BETTER AGREEMENT WITH 00Z SUITE OF MODELS SHOWING THIS ACTIVITY
SPREADING EAST/NORTHEAST AS THE MAIN SHORTWAVE LIFTS NORTHEAST...
THEN SUGGESTS RAPID DEVELOPMENT ACROSS WESTERN AND NORTH CENTRAL
IL THIS AFTERNOON...PERHAPS EARLY THIS AFTERNOON. HOWEVER...
THERE STILL REMAINS SOME UNCERTAINTY REGARDING WHERE CONVECTION
DEVELOPS AND WHETHER IT AFFECTS ALL OR PART OF THE CWA. CONFIDENCE
INCREASES ACROSS THE SOUTHERN HALF/TWO THIRDS OF THE AREA.
WITH THE EXPECTATION THAT THIS MORNING WILL END UP BEING MAINLY
DRY AND EVENTUALLY PARTLY/MOSTLY SUNNY...TEMPS REACHING LOWER 80S
SEEMS ON TRACK ALONG WITH DEWPOINTS REBOUNDING BACK INTO THE
MID/UPPER 60S. SUFFICIENT SHEAR AND STRONG LAPSE RATES COMBINED
WITH THE VERY MOIST/UNSTABLE LOW LEVELS WILL SUPPORT SEVERE
WEATHER ACROSS THE ENTIRE AREA WITH THE MAIN THREAT APPEARING TO
BE DAMAGING WINDS WITH ASSOCIATED LINES/BOWING SEGMENTS. THOUGH
LARGE HAIL WITH STRONGER CORES AND ISOLATED TORNADOES WILL REMAIN
POSSIBLE.
CONVECTION WILL THEN SHIFT EAST THIS EVENING/OVERNIGHT. AS THE
UPPER TROUGH MOVES CLOSER TO THE WESTERN LAKES SATURDAY...ANOTHER
WAVE IS EXPECTED TO LIFT NORTHEAST SATURDAY BUT LIKELY BE A LITTLE
FURTHER EAST WITH CONVECTION LIKELY AFFECTING MAINLY EASTERN IL
AND NORTHWEST INDIANA...PERHAPS ALONG/EAST OF THE I-55 OR I-57
CORRIDORS. SEVERE WEATHER WILL ONCE AGAIN BE POSSIBLE SATURDAY
AFTERNOON INTO SATURDAY EVENING.
NO CHANGES PLANNED TO THE FLASH FLOOD WATCH WHICH IS IN EFFECT FOR
THE ENTIRE AREA THROUGH SATURDAY EVENING. FORECAST STORM TOTAL
RAINFALL...FROM THIS MORNING THROUGH SATURDAY EVENING...RANGES
FROM ABOUT AN INCH NEAR THE WI/IL BORDER TO 2-2.5 INCHES FROM A
CHICAGO/PERU LINE SOUTH. SOME AREAS WILL LIKELY SEE LESS AND SOME
AREAS MAY SEE MORE. INDIVIDUAL STORM MOTION WILL PROBABLY BE FAST
ENOUGH THAT WHILE HEAVY/TORRENTIAL RAIN WILL FALL...ITS DURATION
COULD BE SHORT. BUT IF THE STORMS BEGIN TO TRAIN OVER THE SAME
AREAS...WITH RAINFALL RATES OF 1 TO 2+ INCHES/HOUR...ON ALREADY
SATURATED GROUND...THEN FLASH FLOODING MAY BE POSSIBLE.
AS THE UPPER TROUGH/SURFACE LOW FINALLY DEPART SUNDAY...ONE LAST
WAVE PIVOTING AROUND THE WESTERN LAKES COULD PRODUCE SOME SHOWERS
SUNDAY MORNING. BROAD BUT WEAK HIGH PRESSURE THEN BUILDS ACROSS
THE LAKES SUNDAY AFTERNOON THROUGH MONDAY WITH A SHOT OF COOLER
AIR. WHILE HIGHS ON SUNDAY ARE ONLY EXPECTED TO BE IN THE
60S...LOWER 70S SOUTH...WINDS WILL TURN OFF THE LAKE SUNDAY
AFTERNOON...THUS COOLER/FALLING TEMPS AT THE LAKE SUNDAY
AFTERNOON. LOWS THEN DROP INTO THE 40S IN MANY AREAS MONDAY
MORNING AND POSSIBLY TUESDAY MORNING AS WELL. SEVERAL DAYS OF
EASTERLY WINDS WILL KEEP THE LAKE SHORE AREAS COOLER NEXT WEEK.
PATTERN APPEARS TO TURN MORE ACTIVE AGAIN TUESDAY INTO WEDNESDAY
AS ANOTHER SLOW MOVING UPPER LOW TRACKS ACROSS THE PLAINS THOUGH
ITS STILL FAIRLY EARLY TO DETERMINE WHERE AND WHEN THIS LOW WILL
MOVE THOUGH HAVE INCLUDED CHANCE POPS INTO MID/LATE WEEK AS THIS
NEXT SYSTEM POTENTIALLY APPROACHES. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* GUSTY S WINDS EXPECTED THROUGH THIS AFTN WITH A BRIEF PERIOD OF
SSE WINDS PSBL BEHIND TSRA/SHRA.
* SHRA OR TSRA PSBL THIS AFTN WITH MVFR VSBY PSBL WITH TSRA.
* SCT SHOWERS OVERNIGHT.
* ANOTHER ROUND OF TSRA/SHRA EXPECTED TOMORROW AFTN.
JEE
//DISCUSSION...UPDATED 18Z...
THE ACTIVE PERIOD CONTINUES BUT THERE IS VERY HIGH UNCERTAINTY
REGARDING WHERE AND WHEN CONVECTION WILL OCCUR TODAY. TEMPS HAVE
CLIMBED INTO THE 70S WITH DEWPOINTS IN THE 60S WHICH SUGGESTS
FAVORABLE CONDITIONS. A LOW PRESSURE SYSTEM IS OVER SOUTH DAKOTA
AND A LEFT OVER CONVECTIVE SYSTEM IS OVER NE MO/SE IA/W IL. SHOWERS
ARE SLOWLY MOVING NORTHEAST WITH A FEW CONVECTIVE CELLS FORMING OVER
FORD COUNTY IL IN THE LAST FEW MINUTES. EXPECTING THUNDERSTORMS TO
DEVELOP ACROSS NORTH CENTRAL IL AND PUSH EAST THROUGH THE EASTERN
TERMINALS. SINCE THE AXIS OF BEST INSTABILITY IS EAST OF RFD...KEPT
TS OUT OF RFD. THAT BEING SAID RFD MAY SEE A FEW STRAY SHOWERS OVER
THE NEXT FEW HOURS. GUSTY S WINDS ARE EXPECTED BUT MAY SEE A BRIEF
SHIFT TO SSE WINDS BEHIND THE THUNDERSTORMS.
EXPECTING A NARROW WINDOW OF TSRA OF ABOUT AN HOUR...FOLLOWED BY
SHOWERS. THE AREA WILL REMAIN UNSTABLE OVERNIGHT WITH SCATTERED
SHOWERS EXPECTED OVERNIGHT. ANOTHER ROUND OF TSRA AND SHOWERS IS
EXPECTED LATE SATURDAY AFTERNOON/EARLY AS THE LOW PRESSURE SYSTEM
PASSES TO THE NORTH AND ITS COLD FRONT APPROACHES FROM THE WEST.
STRONG S WINDS ARE ONCE AGAIN EXPECTED TOMORROW...BUT GUSTS WILL NOT
BE AS STRONG.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE IN PRECIP AFFECTING THE TERMINALS.
* LOW CONFIDENCE IN TIMING AND DURATION.
* LOW CONFIDENCE IN SHRA COVERAGE TONIGHT.
* MEDIUM CONFIDENCE IN TIMING OF SHRA/TSRA TOMORROW AFTERNOON.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...CHC OF SHRA DURING THE EVE. MVFR POSSIBLE.
SUNDAY...SLT CHC OF MORNING SHRA.
MONDAY...VFR LIKELY.
TUESDAY...CHC OF MORNING MVFR.
WEDNESDAY & THURSDAY...CHC OF TSRA.
MTF
&&
.MARINE...
222 PM CDT
AN AREA OF LOW PRESSURE THAT HAS PERSISTED OVER THE NORTHERN PLAINS
WILL FINALLY BEGIN TO MOVE EAST TONIGHT...PASSING OVER NORTHERN LAKE
MICHIGAN LATE SATURDAY EVENING WITH A TRAILING COLD FRONT TURNING
MODERATE SOUTHERLY WINDS OF 15 TO 25 KT TO NORTHWESTERLY. MOIST FLOW
AHEAD OF THE FRONT HAS ALREADY LED TO DENSE FOG OVER MUCH OF THE
LAKE WHICH IS EXPECTED TO PERSIST UNTIL THE COLD FRONT PASSES
SATURDAY NIGHT. WINDS SHOULD THEN DIMINISH THROUGH THE DAY SUNDAY AS
HIGH PRESSURE BUILDS IN FROM THE WEST...BECOMING CENTERED OVER LAKE
MICHIGAN ON MONDAY. LOW PRESSURE WILL DEVELOP OVER THE CENTRAL
PLAINS MONDAY...THEN LIFT NORTHEAST TO LAKE MICHIGAN LATE THURSDAY
INTO EARLY FRIDAY.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 7 PM SATURDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 7
PM SATURDAY.
LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ868-LMZ870-
LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM SATURDAY.
SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 10 PM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
225 PM CDT FRI MAY 31 2013
.MESOSCALE DISCUSSION...
INITIAL LOOK AT THE ATMOSPHERE IN PREPARATION OF AFTERNOON/EVENING
CONVECTION. SUPPORT FOR WIDESPREAD SEVERE APPEARS TO BE LESS
PRONOUNCED THAN EARLIER SIGNALS HAD SUGGESTED. A MINIMA OF 0-6KM
BULK SHEAR EXISTS EARLY THIS AFTERNOON ACROSS NORTHCENTRAL/NORTHEAST
ILLINOIS STRETCHING INTO NORTHWEST INDIANA. ALONG THE WESTERN
PERIPHERY OF THIS MINIMA IS AN AXIS OF MUCH HIGHER SHEAR AROUND
70KTS IN IOWA...TO NEARLY 80KTS STRETCHING SOUTH INTO CENTRAL
MISSOURI. VISIBLE IMAGERY SHOWS CONSIDERABLE CLOUD
COVER...REMNANTS/BLOWOFF OF EARLIER CONVECTION TO THE
SOUTHWEST...LIFTING NORTHEAST ACROSS THE CWFA AT THIS TIME. THIS
WILL INHIBIT SFC CAPE FROM GETTING OUT OF CONTROL THROUGH EARLY
THIS AFTERNOON...AND TOGETHER WITH THE MARGINAL SHEAR WOULD TEND
TO LIMIT THE LOCAL POTENTIAL FOR ORGANIZED CONVECTION OVER THE
NEXT FEW HOURS.
MORNING CONVECTION IN MISSOURI CORRELATED TO AN AXIS OF LOW LEVEL
MOISTURE CONVERGENCE AND A WEAK TROUGH DEPICTED AT 850 MB. LATEST
FIELDS FROM THE RAP MODEL SHOW THIS TROUGH AND THE WESTERN FOCUS
FOR THIS MOISTURE CONVERGENCE EXPANDING OUT OF THE SAINT LOUIS
AREA ACROSS ILLINOIS AND WORKING INTO THE CHICAGO METRO AREA BY
LATE AFTERNOON...22Z TO 00Z...WHILE GRADUALLY BECOMING LESS
FOCUSED. HI-RES GUIDANCE IS SUGGESTING THAT AS THIS CONVECTION
BEGINS TO LIFT THROUGH SW IL...IT WILL EXPAND ALONG A LINE
STRETCHING FROM SAINT LOUIS THROUGH BLOOMINGTON TO KANKAKEE AND
TOWARD MICHIGAN CITY.
A SMALLER AREA OF LATE MORNING AND EARLY AFTERNOON ISOLATED
STORMS OVER IOWA ALSO IS NICELY CORRELATED TO AN AXIS OF MOISTURE
CONVERGENCE IN THE RAP...BUT WAS MUCH LESS PRONOUNCED AND
MIGRATING MORE TO THE NORTH RATHER THAN EAST INTO ILLINOIS. THIS
CONVECTION WAS CLOSER TO THE 500MB VORT MAX AND IN AN AREA OF
ANTICIPATED STEEPENING LAPSE RATES THROUGHOUT THE AFTN. AS THE
TROUGH AXIS SLOWLY SLIDES EAST...SOME OF THIS MAY PUSH INTO
NORTHWEST IL BUT MAY NOT HAVE THE LONGEVITY TO CONTINUE ACROSS
NORTHCENTRAL/NORTHEAST IL.
BEACHLER/LENNING
&&
.DISCUSSION...
328 AM...MAIN FORECAST CONCERN AND CHALLENGE REMAINS CONVECTIVE
TRENDS/TIMING THROUGH SATURDAY EVENING ALONG WITH POTENTIAL FOR
SEVERE WEATHER AND HEAVY RAIN/FLOODING.
WAVE OF SHOWERS WITH SOME EMBEDDED THUNDER WILL CONTINUE LIFTING
NORTHEAST AWAY FROM THE AREA EARLY THIS MORNING WITH SUBSIDENCE
INTO THE MID MORNING HOURS EXPECTED TO BRING SEVERAL HOURS OF DRY
WEATHER. ATTENTION THEN SHIFTS TO CONVECTION OVER NORTHEAST
KANSAS/NORTHWEST MISSOURI. MOST RECENT HRRR/RAP GUIDANCE SEEMS IN
BETTER AGREEMENT WITH 00Z SUITE OF MODELS SHOWING THIS ACTIVITY
SPREADING EAST/NORTHEAST AS THE MAIN SHORTWAVE LIFTS NORTHEAST...
THEN SUGGESTS RAPID DEVELOPMENT ACROSS WESTERN AND NORTH CENTRAL
IL THIS AFTERNOON...PERHAPS EARLY THIS AFTERNOON. HOWEVER...
THERE STILL REMAINS SOME UNCERTAINTY REGARDING WHERE CONVECTION
DEVELOPS AND WHETHER IT AFFECTS ALL OR PART OF THE CWA. CONFIDENCE
INCREASES ACROSS THE SOUTHERN HALF/TWO THIRDS OF THE AREA.
WITH THE EXPECTATION THAT THIS MORNING WILL END UP BEING MAINLY
DRY AND EVENTUALLY PARTLY/MOSTLY SUNNY...TEMPS REACHING LOWER 80S
SEEMS ON TRACK ALONG WITH DEWPOINTS REBOUNDING BACK INTO THE
MID/UPPER 60S. SUFFICIENT SHEAR AND STRONG LAPSE RATES COMBINED
WITH THE VERY MOIST/UNSTABLE LOW LEVELS WILL SUPPORT SEVERE
WEATHER ACROSS THE ENTIRE AREA WITH THE MAIN THREAT APPEARING TO
BE DAMAGING WINDS WITH ASSOCIATED LINES/BOWING SEGMENTS. THOUGH
LARGE HAIL WITH STRONGER CORES AND ISOLATED TORNADOES WILL REMAIN
POSSIBLE.
CONVECTION WILL THEN SHIFT EAST THIS EVENING/OVERNIGHT. AS THE
UPPER TROUGH MOVES CLOSER TO THE WESTERN LAKES SATURDAY...ANOTHER
WAVE IS EXPECTED TO LIFT NORTHEAST SATURDAY BUT LIKELY BE A LITTLE
FURTHER EAST WITH CONVECTION LIKELY AFFECTING MAINLY EASTERN IL
AND NORTHWEST INDIANA...PERHAPS ALONG/EAST OF THE I-55 OR I-57
CORRIDORS. SEVERE WEATHER WILL ONCE AGAIN BE POSSIBLE SATURDAY
AFTERNOON INTO SATURDAY EVENING.
NO CHANGES PLANNED TO THE FLASH FLOOD WATCH WHICH IS IN EFFECT FOR
THE ENTIRE AREA THROUGH SATURDAY EVENING. FORECAST STORM TOTAL
RAINFALL...FROM THIS MORNING THROUGH SATURDAY EVENING...RANGES
FROM ABOUT AN INCH NEAR THE WI/IL BORDER TO 2-2.5 INCHES FROM A
CHICAGO/PERU LINE SOUTH. SOME AREAS WILL LIKELY SEE LESS AND SOME
AREAS MAY SEE MORE. INDIVIDUAL STORM MOTION WILL PROBABLY BE FAST
ENOUGH THAT WHILE HEAVY/TORRENTIAL RAIN WILL FALL...ITS DURATION
COULD BE SHORT. BUT IF THE STORMS BEGIN TO TRAIN OVER THE SAME
AREAS...WITH RAINFALL RATES OF 1 TO 2+ INCHES/HOUR...ON ALREADY
SATURATED GROUND...THEN FLASH FLOODING MAY BE POSSIBLE.
AS THE UPPER TROUGH/SURFACE LOW FINALLY DEPART SUNDAY...ONE LAST
WAVE PIVOTING AROUND THE WESTERN LAKES COULD PRODUCE SOME SHOWERS
SUNDAY MORNING. BROAD BUT WEAK HIGH PRESSURE THEN BUILDS ACROSS
THE LAKES SUNDAY AFTERNOON THROUGH MONDAY WITH A SHOT OF COOLER
AIR. WHILE HIGHS ON SUNDAY ARE ONLY EXPECTED TO BE IN THE
60S...LOWER 70S SOUTH...WINDS WILL TURN OFF THE LAKE SUNDAY
AFTERNOON...THUS COOLER/FALLING TEMPS AT THE LAKE SUNDAY
AFTERNOON. LOWS THEN DROP INTO THE 40S IN MANY AREAS MONDAY
MORNING AND POSSIBLY TUESDAY MORNING AS WELL. SEVERAL DAYS OF
EASTERLY WINDS WILL KEEP THE LAKE SHORE AREAS COOLER NEXT WEEK.
PATTERN APPEARS TO TURN MORE ACTIVE AGAIN TUESDAY INTO WEDNESDAY
AS ANOTHER SLOW MOVING UPPER LOW TRACKS ACROSS THE PLAINS THOUGH
ITS STILL FAIRLY EARLY TO DETERMINE WHERE AND WHEN THIS LOW WILL
MOVE THOUGH HAVE INCLUDED CHANCE POPS INTO MID/LATE WEEK AS THIS
NEXT SYSTEM POTENTIALLY APPROACHES. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* GUSTY S WINDS EXPECTED THIS AFTN WITH A BRIEF PERIOD OF SSE
WINDS PSBL BEHIND TSRA.
* BRIEF PERIOD OF TSRA THIS AFTN WITH MVFR VSBY PSBL.
* SHRA EXPECTED BEHIND TSRA WITH SCT SHOWERS OVERNIGHT.
* ANOTHER ROUND OF TSRA/SHRA EXPECTED TOMORROW AFTN.
JEE
//DISCUSSION...UPDATED 18Z...
THE ACTIVE PERIOD CONTINUES BUT THERE IS VERY HIGH UNCERTAINTY
REGARDING WHERE AND WHEN CONVECTION WILL OCCUR TODAY. TEMPS HAVE
CLIMBED INTO THE 70S WITH DEWPOINTS IN THE 60S WHICH SUGGESTS
FAVORABLE CONDITIONS. A LOW PRESSURE SYSTEM IS OVER SOUTH DAKOTA
AND A LEFT OVER CONVECTIVE SYSTEM IS OVER NE MO/SE IA/W IL. SHOWERS
ARE SLOWLY MOVING NORTHEAST WITH A FEW CONVECTIVE CELLS FORMING OVER
FORD COUNTY IL IN THE LAST FEW MINUTES. EXPECTING THUNDERSTORMS TO
DEVELOP ACROSS NORTH CENTRAL IL AND PUSH EAST THROUGH THE EASTERN
TERMINALS. SINCE THE AXIS OF BEST INSTABILITY IS EAST OF RFD...KEPT
TS OUT OF RFD. THAT BEING SAID RFD MAY SEE A FEW STRAY SHOWERS OVER
THE NEXT FEW HOURS. GUSTY S WINDS ARE EXPECTED BUT MAY SEE A BRIEF
SHIFT TO SSE WINDS BEHIND THE THUNDERSTORMS.
EXPECTING A NARROW WINDOW OF TSRA OF ABOUT AN HOUR...FOLLOWED BY
SHOWERS. THE AREA WILL REMAIN UNSTABLE OVERNIGHT WITH SCATTERED
SHOWERS EXPECTED OVERNIGHT. ANOTHER ROUND OF TSRA AND SHOWERS IS
EXPECTED LATE SATURDAY AFTERNOON/EARLY AS THE LOW PRESSURE SYSTEM
PASSES TO THE NORTH AND ITS COLD FRONT APPROACHES FROM THE WEST.
STRONG S WINDS ARE ONCE AGAIN EXPECTED TOMORROW...BUT GUSTS WILL NOT
BE AS STRONG.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN PRECIP AFFECTING THE AIRPORTS THIS AFTERNOON.
* LOW CONFIDENCE IN TIMING AND DURATION.
* LOW CONFIDENCE IN SHRA COVERAGE TONIGHT.
* MEDIUM CONFIDENCE IN TIMING OF SHRA/TSRA TOMORROW AFTERNOON.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...CHC OF SHRA DURING THE EVE. MVFR POSSIBLE.
SUNDAY...SLT CHC OF MORNING SHRA.
MONDAY...VFR LIKELY.
TUESDAY...CHC OF MORNING MVFR.
WEDNESDAY & THURSDAY...CHC OF TSRA.
MTF
&&
.MARINE...
222 PM CDT
AN AREA OF LOW PRESSURE THAT HAS PERSISTED OVER THE NORTHERN PLAINS
WILL FINALLY BEGIN TO MOVE EAST TONIGHT...PASSING OVER NORTHERN LAKE
MICHIGAN LATE SATURDAY EVENING WITH A TRAILING COLD FRONT TURNING
MODERATE SOUTHERLY WINDS OF 15 TO 25 KT TO NORTHWESTERLY. MOIST FLOW
AHEAD OF THE FRONT HAS ALREADY LED TO DENSE FOG OVER MUCH OF THE
LAKE WHICH IS EXPECTED TO PERSIST UNTIL THE COLD FRONT PASSES
SATURDAY NIGHT. WINDS SHOULD THEN DIMINISH THROUGH THE DAY SUNDAY AS
HIGH PRESSURE BUILDS IN FROM THE WEST...BECOMING CENTERED OVER LAKE
MICHIGAN ON MONDAY. LOW PRESSURE WILL DEVELOP OVER THE CENTRAL
PLAINS MONDAY...THEN LIFT NORTHEAST TO LAKE MICHIGAN LATE THURSDAY
INTO EARLY FRIDAY.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 7 PM SATURDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 7
PM SATURDAY.
LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ868-LMZ870-
LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM SATURDAY.
SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 7 PM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
128 PM CDT FRI MAY 31 2013
.MESOSCALE DISCUSSION...115 PM CDT
INITIAL LOOK AT THE ATMOSPHERE IN PREPARATION OF AFTERNOON/EVENING
CONVECTION. SUPPORT FOR WIDESPREAD SEVERE APPEARS TO BE LESS
PRONOUNCED THAN EARLIER SIGNALS HAD SUGGESTED. A MINIMA OF 0-6KM
BULK SHEAR EXISTS EARLY THIS AFTERNOON ACROSS NORTHCENTRAL/NORTHEAST
ILLINOIS STRETCHING INTO NORTHWEST INDIANA. ALONG THE WESTERN
PERIPHERY OF THIS MINIMA IS AN AXIS OF MUCH HIGHER SHEAR AROUND
70KTS IN IOWA...TO NEARLY 80KTS STRETCHING SOUTH INTO CENTRAL
MISSOURI. VISIBLE IMAGERY SHOWS CONSIDERABLE CLOUD
COVER...REMNANTS/BLOWOFF OF EARLIER CONVECTION TO THE
SOUTHWEST...LIFTING NORTHEAST ACROSS THE CWFA AT THIS TIME. THIS
WILL INHIBIT SFC CAPE FROM GETTING OUT OF CONTROL THROUGH EARLY
THIS AFTERNOON...AND TOGETHER WITH THE MARGINAL SHEAR WOULD TEND
TO LIMIT THE LOCAL POTENTIAL FOR ORGANIZED CONVECTION OVER THE
NEXT FEW HOURS.
MORNING CONVECTION IN MISSOURI CORRELATED TO AN AXIS OF LOW LEVEL
MOISTURE CONVERGENCE AND A WEAK TROUGH DEPICTED AT 850 MB. LATEST
FIELDS FROM THE RAP MODEL SHOW THIS TROUGH AND THE WESTERN FOCUS
FOR THIS MOISTURE CONVERGENCE EXPANDING OUT OF THE SAINT LOUIS
AREA ACROSS ILLINOIS AND WORKING INTO THE CHICAGO METRO AREA BY
LATE AFTERNOON...22Z TO 00Z...WHILE GRADUALLY BECOMING LESS
FOCUSED. HI-RES GUIDANCE IS SUGGESTING THAT AS THIS CONVECTION
BEGINS TO LIFT THROUGH SW IL...IT WILL EXPAND ALONG A LINE
STRETCHING FROM SAINT LOUIS THROUGH BLOOMINGTON TO KANKAKEE AND
TOWARD MICHIGAN CITY.
A SMALLER AREA OF LATE MORNING AND EARLY AFTERNOON ISOLATED
STORMS OVER IOWA ALSO IS NICELY CORRELATED TO AN AXIS OF MOISTURE
CONVERGENCE IN THE RAP...BUT WAS MUCH LESS PRONOUNCED AND
MIGRATING MORE TO THE NORTH RATHER THAN EAST INTO ILLINOIS. THIS
CONVECTION WAS CLOSER TO THE 500MB VORT MAX AND IN AN AREA OF
ANTICIPATED STEEPENING LAPSE RATES THROUGHOUT THE AFTN. AS THE
TROUGH AXIS SLOWLY SLIDES EAST...SOME OF THIS MAY PUSH INTO
NORTHWEST IL BUT MAY NOT HAVE THE LONGEVITY TO CONTINUE ACROSS
NORTHCENTRAL/NORTHEAST IL.
BEACHLER/LENNING
&&
.DISCUSSION...
328 AM...MAIN FORECAST CONCERN AND CHALLENGE REMAINS CONVECTIVE
TRENDS/TIMING THROUGH SATURDAY EVENING ALONG WITH POTENTIAL FOR
SEVERE WEATHER AND HEAVY RAIN/FLOODING.
WAVE OF SHOWERS WITH SOME EMBEDDED THUNDER WILL CONTINUE LIFTING
NORTHEAST AWAY FROM THE AREA EARLY THIS MORNING WITH SUBSIDENCE
INTO THE MID MORNING HOURS EXPECTED TO BRING SEVERAL HOURS OF DRY
WEATHER. ATTENTION THEN SHIFTS TO CONVECTION OVER NORTHEAST
KANSAS/NORTHWEST MISSOURI. MOST RECENT HRRR/RAP GUIDANCE SEEMS IN
BETTER AGREEMENT WITH 00Z SUITE OF MODELS SHOWING THIS ACTIVITY
SPREADING EAST/NORTHEAST AS THE MAIN SHORTWAVE LIFTS NORTHEAST...
THEN SUGGESTS RAPID DEVELOPMENT ACROSS WESTERN AND NORTH CENTRAL
IL THIS AFTERNOON...PERHAPS EARLY THIS AFTERNOON. HOWEVER...
THERE STILL REMAINS SOME UNCERTAINTY REGARDING WHERE CONVECTION
DEVELOPS AND WHETHER IT AFFECTS ALL OR PART OF THE CWA. CONFIDENCE
INCREASES ACROSS THE SOUTHERN HALF/TWO THIRDS OF THE AREA.
WITH THE EXPECTATION THAT THIS MORNING WILL END UP BEING MAINLY
DRY AND EVENTUALLY PARTLY/MOSTLY SUNNY...TEMPS REACHING LOWER 80S
SEEMS ON TRACK ALONG WITH DEWPOINTS REBOUNDING BACK INTO THE
MID/UPPER 60S. SUFFICIENT SHEAR AND STRONG LAPSE RATES COMBINED
WITH THE VERY MOIST/UNSTABLE LOW LEVELS WILL SUPPORT SEVERE
WEATHER ACROSS THE ENTIRE AREA WITH THE MAIN THREAT APPEARING TO
BE DAMAGING WINDS WITH ASSOCIATED LINES/BOWING SEGMENTS. THOUGH
LARGE HAIL WITH STRONGER CORES AND ISOLATED TORNADOES WILL REMAIN
POSSIBLE.
CONVECTION WILL THEN SHIFT EAST THIS EVENING/OVERNIGHT. AS THE
UPPER TROUGH MOVES CLOSER TO THE WESTERN LAKES SATURDAY...ANOTHER
WAVE IS EXPECTED TO LIFT NORTHEAST SATURDAY BUT LIKELY BE A LITTLE
FURTHER EAST WITH CONVECTION LIKELY AFFECTING MAINLY EASTERN IL
AND NORTHWEST INDIANA...PERHAPS ALONG/EAST OF THE I-55 OR I-57
CORRIDORS. SEVERE WEATHER WILL ONCE AGAIN BE POSSIBLE SATURDAY
AFTERNOON INTO SATURDAY EVENING.
NO CHANGES PLANNED TO THE FLASH FLOOD WATCH WHICH IS IN EFFECT FOR
THE ENTIRE AREA THROUGH SATURDAY EVENING. FORECAST STORM TOTAL
RAINFALL...FROM THIS MORNING THROUGH SATURDAY EVENING...RANGES
FROM ABOUT AN INCH NEAR THE WI/IL BORDER TO 2-2.5 INCHES FROM A
CHICAGO/PERU LINE SOUTH. SOME AREAS WILL LIKELY SEE LESS AND SOME
AREAS MAY SEE MORE. INDIVIDUAL STORM MOTION WILL PROBABLY BE FAST
ENOUGH THAT WHILE HEAVY/TORRENTIAL RAIN WILL FALL...ITS DURATION
COULD BE SHORT. BUT IF THE STORMS BEGIN TO TRAIN OVER THE SAME
AREAS...WITH RAINFALL RATES OF 1 TO 2+ INCHES/HOUR...ON ALREADY
SATURATED GROUND...THEN FLASH FLOODING MAY BE POSSIBLE.
AS THE UPPER TROUGH/SURFACE LOW FINALLY DEPART SUNDAY...ONE LAST
WAVE PIVOTING AROUND THE WESTERN LAKES COULD PRODUCE SOME SHOWERS
SUNDAY MORNING. BROAD BUT WEAK HIGH PRESSURE THEN BUILDS ACROSS
THE LAKES SUNDAY AFTERNOON THROUGH MONDAY WITH A SHOT OF COOLER
AIR. WHILE HIGHS ON SUNDAY ARE ONLY EXPECTED TO BE IN THE
60S...LOWER 70S SOUTH...WINDS WILL TURN OFF THE LAKE SUNDAY
AFTERNOON...THUS COOLER/FALLING TEMPS AT THE LAKE SUNDAY
AFTERNOON. LOWS THEN DROP INTO THE 40S IN MANY AREAS MONDAY
MORNING AND POSSIBLY TUESDAY MORNING AS WELL. SEVERAL DAYS OF
EASTERLY WINDS WILL KEEP THE LAKE SHORE AREAS COOLER NEXT WEEK.
PATTERN APPEARS TO TURN MORE ACTIVE AGAIN TUESDAY INTO WEDNESDAY
AS ANOTHER SLOW MOVING UPPER LOW TRACKS ACROSS THE PLAINS THOUGH
ITS STILL FAIRLY EARLY TO DETERMINE WHERE AND WHEN THIS LOW WILL
MOVE THOUGH HAVE INCLUDED CHANCE POPS INTO MID/LATE WEEK AS THIS
NEXT SYSTEM POTENTIALLY APPROACHES. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* GUSTY S WINDS EXPECTED THIS AFTN WITH A BRIEF PERIOD OF SSE
WINDS PSBL BEHIND TSRA.
* BRIEF PERIOD OF TSRA THIS AFTN WITH MVFR VSBY PSBL.
* SHRA EXPECTED BEHIND TSRA WITH SCT SHOWERS OVERNIGHT.
* ANOTHER ROUND OF TSRA/SHRA EXPECTED TOMORROW AFTN.
JEE
//DISCUSSION...UPDATED 18Z...
THE ACTIVE PERIOD CONTINUES BUT THERE IS VERY HIGH UNCERTAINTY
REGARDING WHERE AND WHEN CONVECTION WILL OCCUR TODAY. TEMPS HAVE
CLIMBED INTO THE 70S WITH DEWPOINTS IN THE 60S WHICH SUGGESTS
FAVORABLE CONDITIONS. A LOW PRESSURE SYSTEM IS OVER SOUTH DAKOTA
AND A LEFT OVER CONVECTIVE SYSTEM IS OVER NE MO/SE IA/W IL. SHOWERS
ARE SLOWLY MOVING NORTHEAST WITH A FEW CONVECTIVE CELLS FORMING OVER
FORD COUNTY IL IN THE LAST FEW MINUTES. EXPECTING THUNDERSTORMS TO
DEVELOP ACROSS NORTH CENTRAL IL AND PUSH EAST THROUGH THE EASTERN
TERMINALS. SINCE THE AXIS OF BEST INSTABILITY IS EAST OF RFD...KEPT
TS OUT OF RFD. THAT BEING SAID RFD MAY SEE A FEW STRAY SHOWERS OVER
THE NEXT FEW HOURS. GUSTY S WINDS ARE EXPECTED BUT MAY SEE A BRIEF
SHIFT TO SSE WINDS BEHIND THE THUNDERSTORMS.
EXPECTING A NARROW WINDOW OF TSRA OF ABOUT AN HOUR...FOLLOWED BY
SHOWERS. THE AREA WILL REMAIN UNSTABLE OVERNIGHT WITH SCATTERED
SHOWERS EXPECTED OVERNIGHT. ANOTHER ROUND OF TSRA AND SHOWERS IS
EXPECTED LATE SATURDAY AFTERNOON/EARLY AS THE LOW PRESSURE SYSTEM
PASSES TO THE NORTH AND ITS COLD FRONT APPROACHES FROM THE WEST.
STRONG S WINDS ARE ONCE AGAIN EXPECTED TOMORROW...BUT GUSTS WILL NOT
BE AS STRONG.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN PRECIP AFFECTING THE AIRPORTS THIS AFTERNOON.
* LOW CONFIDENCE IN TIMING AND DURATION.
* LOW CONFIDENCE IN SHRA COVERAGE TONIGHT.
* MEDIUM CONFIDENCE IN TIMING OF SHRA/TSRA TOMORROW AFTERNOON.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...CHC OF SHRA DURING THE EVE. MVFR POSSIBLE.
SUNDAY...SLT CHC OF MORNING SHRA.
MONDAY...VFR LIKELY.
TUESDAY...CHC OF MORNING MVFR.
WEDNESDAY & THURSDAY...CHC OF TSRA.
MTF
&&
.MARINE...
230 AM CDT
ANOMALOUSLY DEEP LOW PRESSURE ACROSS THE DAKOTAS WILL CONTINUE
SOUTHERLY FLOW ACROSS THE LAKE. THE STABLE MARINE LAYER WILL KEEP
WINDS FROM BECOMING TOO GUSTY...ALTHOUGH NEARSHORE AREAS OF IL AND
IN WILL LIKELY BE CLOSE TO SMALL CRAFT CRITERION WINDS GIVEN THE
OFFSHORE COMPONENT. PERIODS OF STORMS ARE LIKELY ACROSS THE LAKE
THROUGH TONIGHT AND POSSIBLY INTO SATURDAY. THE SYSTEM WILL SWING
A COLD FRONT ACROSS THE LAKE LATE SATURDAY NIGHT ALLOWING FOR A
WIND SHIFT TO NORTHWEST. THESE WINDS WILL TURN NORTHERLY ON SUNDAY
AND GRADUALLY DIMINISH INTO MONDAY AS HIGH PRESSURE BUILDS OVER
THE LAKE. THIS HIGH WILL SLOWLY SHIFT EAST THROUGH MIDWEEK...BUT
CONTINUE TO STRENGTHEN SO THE RETURN FLOW INFLUENCE LOOKS TO BE
SLOW TO SPREAD ACROSS THE LAKE. THIS SHOULD OFFER A FAIRLY QUIET
MARINE PERIOD FROM SUN-THU.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 7 PM SATURDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 7
PM SATURDAY.
LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ868-LMZ870-
LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM SATURDAY.
SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 7 PM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
116 PM CDT FRI MAY 31 2013
.MESOSCALE DISCUSSION...
115 PM CDT
INITIAL LOOK AT THE ATMOSPHERE IN PREPARATION OF AFTERNOON/EVENING
CONVECTION. SUPPORT FOR WIDESPREAD SEVERE APPEARS TO BE LESS
PRONOUNCED THAN EARLIER SIGNALS HAD SUGGESTED. A MINIMA OF 0-6KM
BULK SHEAR EXISTS EARLY THIS AFTERNOON ACROSS NORTHCENTRAL/NORTHEAST
ILLINOIS STRETCHING INTO NORTHWEST INDIANA. ALONG THE WESTERN
PERIPHERY OF THIS MINIMA IS AN AXIS OF MUCH HIGHER SHEAR AROUND
70KTS IN IOWA...TO NEARLY 80KTS STRETCHING SOUTH INTO CENTRAL
MISSOURI. VISIBLE IMAGERY SHOWS CONSIDERABLE CLOUD
COVER...REMNANTS/BLOWOFF OF EARLIER CONVECTION TO THE
SOUTHWEST...LIFTING NORTHEAST ACROSS THE CWFA AT THIS TIME. THIS
WILL INHIBIT SFC CAPE FROM GETTING OUT OF CONTROL THROUGH EARLY
THIS AFTERNOON...AND TOGETHER WITH THE MARGINAL SHEAR WOULD TEND
TO LIMIT THE LOCAL POTENTIAL FOR ORGANIZED CONVECTION OVER THE
NEXT FEW HOURS.
MORNING CONVECTION IN MISSOURI CORRELATED TO AN AXIS OF LOW LEVEL
MOISTURE CONVERGENCE AND A WEAK TROUGH DEPICTED AT 850 MB. LATEST
FIELDS FROM THE RAP MODEL SHOW THIS TROUGH AND THE WESTERN FOCUS
FOR THIS MOISTURE CONVERGENCE EXPANDING OUT OF THE SAINT LOUIS
AREA ACROSS ILLINOIS AND WORKING INTO THE CHICAGO METRO AREA BY
LATE AFTERNOON...22Z TO 00Z...WHILE GRADUALLY BECOMING LESS
FOCUSED. HI-RES GUIDANCE IS SUGGESTING THAT AS THIS CONVECTION
BEGINS TO LIFT THROUGH SW IL...IT WILL EXPAND ALONG A LINE
STRETCHING FROM SAINT LOUIS THROUGH BLOOMINGTON TO KANKAKEE AND
TOWARD MICHIGAN CITY.
A SMALLER AREA OF LATE MORNING AND EARLY AFTERNOON ISOLATED
STORMS OVER IOWA ALSO IS NICELY CORRELATED TO AN AXIS OF MOISTURE
CONVERGENCE IN THE RAP...BUT WAS MUCH LESS PRONOUNCED AND
MIGRATING MORE TO THE NORTH RATHER THAN EAST INTO ILLINOIS. THIS
CONVECTION WAS CLOSER TO THE 500MB VORT MAX AND IN AN AREA OF
ANTICIPATED STEEPENING LAPSE RATES THROUGHOUT THE AFTN. AS THE
TROUGH AXIS SLOWLY SLIDES EAST...SOME OF THIS MAY PUSH INTO
NORTHWEST IL BUT MAY NOT HAVE THE LONGEVITY TO CONTINUE ACROSS
NORTHCENTRAL/NORTHEAST IL.
BEACHLER/LENNING
&&
.DISCUSSION...
328 AM...MAIN FORECAST CONCERN AND CHALLENGE REMAINS CONVECTIVE
TRENDS/TIMING THROUGH SATURDAY EVENING ALONG WITH POTENTIAL FOR
SEVERE WEATHER AND HEAVY RAIN/FLOODING.
WAVE OF SHOWERS WITH SOME EMBEDDED THUNDER WILL CONTINUE LIFTING
NORTHEAST AWAY FROM THE AREA EARLY THIS MORNING WITH SUBSIDENCE
INTO THE MID MORNING HOURS EXPECTED TO BRING SEVERAL HOURS OF DRY
WEATHER. ATTENTION THEN SHIFTS TO CONVECTION OVER NORTHEAST
KANSAS/NORTHWEST MISSOURI. MOST RECENT HRRR/RAP GUIDANCE SEEMS IN
BETTER AGREEMENT WITH 00Z SUITE OF MODELS SHOWING THIS ACTIVITY
SPREADING EAST/NORTHEAST AS THE MAIN SHORTWAVE LIFTS NORTHEAST...
THEN SUGGESTS RAPID DEVELOPMENT ACROSS WESTERN AND NORTH CENTRAL
IL THIS AFTERNOON...PERHAPS EARLY THIS AFTERNOON. HOWEVER...
THERE STILL REMAINS SOME UNCERTAINTY REGARDING WHERE CONVECTION
DEVELOPS AND WHETHER IT AFFECTS ALL OR PART OF THE CWA. CONFIDENCE
INCREASES ACROSS THE SOUTHERN HALF/TWO THIRDS OF THE AREA.
WITH THE EXPECTATION THAT THIS MORNING WILL END UP BEING MAINLY
DRY AND EVENTUALLY PARTLY/MOSTLY SUNNY...TEMPS REACHING LOWER 80S
SEEMS ON TRACK ALONG WITH DEWPOINTS REBOUNDING BACK INTO THE
MID/UPPER 60S. SUFFICIENT SHEAR AND STRONG LAPSE RATES COMBINED
WITH THE VERY MOIST/UNSTABLE LOW LEVELS WILL SUPPORT SEVERE
WEATHER ACROSS THE ENTIRE AREA WITH THE MAIN THREAT APPEARING TO
BE DAMAGING WINDS WITH ASSOCIATED LINES/BOWING SEGMENTS. THOUGH
LARGE HAIL WITH STRONGER CORES AND ISOLATED TORNADOES WILL REMAIN
POSSIBLE.
CONVECTION WILL THEN SHIFT EAST THIS EVENING/OVERNIGHT. AS THE
UPPER TROUGH MOVES CLOSER TO THE WESTERN LAKES SATURDAY...ANOTHER
WAVE IS EXPECTED TO LIFT NORTHEAST SATURDAY BUT LIKELY BE A LITTLE
FURTHER EAST WITH CONVECTION LIKELY AFFECTING MAINLY EASTERN IL
AND NORTHWEST INDIANA...PERHAPS ALONG/EAST OF THE I-55 OR I-57
CORRIDORS. SEVERE WEATHER WILL ONCE AGAIN BE POSSIBLE SATURDAY
AFTERNOON INTO SATURDAY EVENING.
NO CHANGES PLANNED TO THE FLASH FLOOD WATCH WHICH IS IN EFFECT FOR
THE ENTIRE AREA THROUGH SATURDAY EVENING. FORECAST STORM TOTAL
RAINFALL...FROM THIS MORNING THROUGH SATURDAY EVENING...RANGES
FROM ABOUT AN INCH NEAR THE WI/IL BORDER TO 2-2.5 INCHES FROM A
CHICAGO/PERU LINE SOUTH. SOME AREAS WILL LIKELY SEE LESS AND SOME
AREAS MAY SEE MORE. INDIVIDUAL STORM MOTION WILL PROBABLY BE FAST
ENOUGH THAT WHILE HEAVY/TORRENTIAL RAIN WILL FALL...ITS DURATION
COULD BE SHORT. BUT IF THE STORMS BEGIN TO TRAIN OVER THE SAME
AREAS...WITH RAINFALL RATES OF 1 TO 2+ INCHES/HOUR...ON ALREADY
SATURATED GROUND...THEN FLASH FLOODING MAY BE POSSIBLE.
AS THE UPPER TROUGH/SURFACE LOW FINALLY DEPART SUNDAY...ONE LAST
WAVE PIVOTING AROUND THE WESTERN LAKES COULD PRODUCE SOME SHOWERS
SUNDAY MORNING. BROAD BUT WEAK HIGH PRESSURE THEN BUILDS ACROSS
THE LAKES SUNDAY AFTERNOON THROUGH MONDAY WITH A SHOT OF COOLER
AIR. WHILE HIGHS ON SUNDAY ARE ONLY EXPECTED TO BE IN THE
60S...LOWER 70S SOUTH...WINDS WILL TURN OFF THE LAKE SUNDAY
AFTERNOON...THUS COOLER/FALLING TEMPS AT THE LAKE SUNDAY
AFTERNOON. LOWS THEN DROP INTO THE 40S IN MANY AREAS MONDAY
MORNING AND POSSIBLY TUESDAY MORNING AS WELL. SEVERAL DAYS OF
EASTERLY WINDS WILL KEEP THE LAKE SHORE AREAS COOLER NEXT WEEK.
PATTERN APPEARS TO TURN MORE ACTIVE AGAIN TUESDAY INTO WEDNESDAY
AS ANOTHER SLOW MOVING UPPER LOW TRACKS ACROSS THE PLAINS THOUGH
ITS STILL FAIRLY EARLY TO DETERMINE WHERE AND WHEN THIS LOW WILL
MOVE THOUGH HAVE INCLUDED CHANCE POPS INTO MID/LATE WEEK AS THIS
NEXT SYSTEM POTENTIALLY APPROACHES. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* S WINDS GUSTING TO ARND 25 KT THROUGH THE DAY.
* SHOWERS AND THUNDERSTORMS EXPECTED AGAIN THIS AFTN.
* BEST CHANCE FOR TSRA IS IN THE MID AFTN...WITH STRONG TO SEVERE
STORMS PSBL.
JEE
//DISCUSSION...UPDATED 12Z...
A BREAK IN CONVECTION WILL BE OVER THE AREA THROUGH THE REMAINDER
OF THE MORNING RUSH. LINGERING MVFR CIGS FROM LAST NIGHTS RAIN
HAVE MAINLY DISSIPATED AND/OR SHIFTED EAST...SO THE MAIN CONCERN
CENTERS ON TIMING THE STORM CHANCES. OUR CONVECTIVE POTENTIAL
LOOKS TO BEGIN FROM ONGOING STORMS IN MISSOURI...WHETHER IT BE
FROM THE COMPLEX ITSELF EVOLVING NORTHEAST OR SOME OFFSHOOT OF
IT. THE STRONGEST CONVECTION MAY END UP REMAINING SOUTH OF THE
TERMINALS...AT LEAST AT FIRST. BY MID-AFTERNOON...RE-ENHANCEMENT
OF STORMS BOTH IN COVERAGE AND IN MAGNITUDE IS EXPECTED
IMMEDIATELY AHEAD OF THE DECAYING SYSTEM AND ITS FORCING. WHETHER
THAT WILL BE FAR ENOUGH NORTH TO IMPACT ORD AND THE OTHER TAF
SITES WITH HEAVY CONVECTION IS TOO CHALLENGING TO TELL FOR SURE
YET...BUT IT DOES LOOK LIKE IT SHOULD BE AT LEAST CLOSE. SO HAVE
PRESERVED THE PREVAILING THUNDER AT THE MOST FAVORED TIME
WINDOWS...BUT ITS POSSIBLE IT HAPPENS BEFORE AND/OR AFTER THIS
DEPENDING ON NUMEROUS FACTORS. THIS IS ALWAYS A CHALLENGE WITH
ONGOING EARLY MORNING CONVECTION AND HOW IT ALTERS THE ATMOSPHERE.
SOUTHERLY WINDS ARE LIKELY TO BEGIN GUSTING BY MID-MORNING WITH
GUSTS TO NEAR 25 KT AT TIMES. STORM WINDS AND RAIN-COOLED OUTFLOW
COULD LEAD TO STRONGER WIND GUSTS AND VARIABILITY IN DIRECTION IF
THEY WERE TO PASS OVER THE AIRFIELDS.
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN SHRA/TSRA DVLPG.
* MEDIUM CONFIDENCE IN TIMING OF SHRA/TSRA.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...CHC OF SHRA DURING THE EVE. MVFR POSSIBLE.
SUNDAY...SLT CHC OF MORNING SHRA.
MONDAY...VFR LIKELY.
TUESDAY...CHC OF MORNING MVFR.
WEDNESDAY & THURSDAY...CHC OF TSRA.
MTF
&&
.MARINE...
230 AM CDT
ANOMALOUSLY DEEP LOW PRESSURE ACROSS THE DAKOTAS WILL CONTINUE
SOUTHERLY FLOW ACROSS THE LAKE. THE STABLE MARINE LAYER WILL KEEP
WINDS FROM BECOMING TOO GUSTY...ALTHOUGH NEARSHORE AREAS OF IL AND
IN WILL LIKELY BE CLOSE TO SMALL CRAFT CRITERION WINDS GIVEN THE
OFFSHORE COMPONENT. PERIODS OF STORMS ARE LIKELY ACROSS THE LAKE
THROUGH TONIGHT AND POSSIBLY INTO SATURDAY. THE SYSTEM WILL SWING
A COLD FRONT ACROSS THE LAKE LATE SATURDAY NIGHT ALLOWING FOR A
WIND SHIFT TO NORTHWEST. THESE WINDS WILL TURN NORTHERLY ON SUNDAY
AND GRADUALLY DIMINISH INTO MONDAY AS HIGH PRESSURE BUILDS OVER
THE LAKE. THIS HIGH WILL SLOWLY SHIFT EAST THROUGH MIDWEEK...BUT
CONTINUE TO STRENGTHEN SO THE RETURN FLOW INFLUENCE LOOKS TO BE
SLOW TO SPREAD ACROSS THE LAKE. THIS SHOULD OFFER A FAIRLY QUIET
MARINE PERIOD FROM SUN-THU.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 7 PM SATURDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 7
PM SATURDAY.
LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ868-LMZ870-
LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM SATURDAY.
SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 7 PM FRIDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
705 PM EDT FRI MAY 31 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 353 PM EDT FRI MAY 31 2013
SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS WILL IMPACT CENTRAL
INDIANA AS A SLOW MOVING COLD FRONT APPROACHES. THE FRONT WILL MOVE
THROUGH THE REGION SATURDAY NIGHT WITH COOLER AND MUCH DRIER AIR
SPREADING IN WITH HIGH PRESSURE FOR THE FIRST HALF OF THE WORK WEEK.
CHANCES FOR THUNDERSTORMS WILL RETURN THURSDAY AND FRIDAY AS A COLD
FRONT MOVES INTO THE REGION.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 353 PM EDT FRI MAY 31 2013
BULK OF THE RAINFALL FROM EARLIER COMPLEX HAS SHIFTED EAST AND
INTENSIFIED AS IT HAS MOVED INTO A MORE UNSTABLE AIRMASS ACROSS
NORTHEAST KENTUCKY AND WESTERN OHIO. MUCH OF THE FORECAST AREA
REMAINS SHROUDED IN A RELATIVELY THICK VEIL OF CLOUD COVER WITH SOME
BREAKS HAVING DEVELOPED OVER THE WABASH VALLEY. THIS HAS
SIGNIFICANTLY IMPEDED TEMP RISES SO FAR...ALTHOUGH MUCH OF THE
FORECAST AREA HAS MADE IT INTO THE 70S AS OF 19Z.
DIFFICULT FORECAST FOR TONIGHT WITH CONCERNS GROWING FOR HEAVY RAIN
AND FLOODING AND POTENTIALLY A DECREASING THREAT FOR SEVERE WEATHER.
LITTLE IN THE WAY OF INSTABILITY ACROSS THE FORECAST AREA AS THE
CLOUDS AND RAIN HAVE REALLY WORKED OVER THE AIRMASS. AS
MENTIONED...DO EXPECT SOME THINNING OF THE CANOPY OVER THE NEXT FEW
HOURS WHICH SHOULD ALLOW FOR SOME DESTABILIZATION TO TAKE PLACE.
HOWEVER...PRESENCE OF WEAKENING MCV OVER CENTRAL ILLINOIS IS LIKELY
TO MAINTAIN A FAIR AMOUNT OF CLOUD COVER RIGHT INTO THE EVENING AND
SHOULD KEEP CONVECTION SCATTERED THROUGH 00Z.
EXPECT ROBUST CONVECTIVE DEVELOPMENT OVER THE OZARKS BACK INTO
OKLAHOMA AS THE AFTERNOON WEARS ON...WITH ADDITIONAL DEVELOPMENT
LIKELY EXPANDING NORTHEAST INTO THE MISSISSIPPI VALLEY AND INTO
ILLINOIS AS INCREASED BL SHEAR AND FORCING ALOFT COURTESY OF AN
INTENSIFYING UPPER JET. NOCTURNAL LOW LEVEL JET WILL ONCE AGAIN
DEVELOP AND NOSE INTO THE REGION AFTER NIGHTFALL AND COMBINED WITH
THE BETTER UPPER LEVEL FORCING APPROACHING FROM THE WEST AND
WHATEVER INSTABILITY CAN BE GLEANED OVER THE NEXT SEVERAL
HOURS...ANTICIPATE CONVECTION TO THE WEST TO COALESCE INTO AN MCS
AND DROP SOUTHEAST INTO THE FORECAST AREA OVERNIGHT. LACK OF MORE
SUBSTANTIAL INSTABILITY HAS RAISED DOUBTS AS TO WHETHER STORMS WILL
BE SEVERE AS THEY ENTER THE FORECAST AREA. FEELING AT THIS POINT IS
THAT STORMS WILL BE STRONG WITH POTENTIALLY AN ISOLATED RISK FOR
DAMAGING WINDS. OTHERWISE...THE PRIMARY CONCERN WILL BE THE HEAVY
RAIN.
HEAVY RAIN AND FLOODING IS BECOMING A GREATER CONCERN...ESPECIALLY
ACROSS THE WABASH VALLEY WHICH EXPERIENCED 1 TO 2 INCHES OF RAIN
LAST NIGHT AND EARLY THIS MORNING. PRECIPITABLE WATER VALUES IN
EXCESS OF 1.75 INCHES ARE ANTICIPATED OVERNIGHT WITH A DEEP
SATURATED COLUMN EXTENDING UP TO NEAR 650MB. IN ADDITION...BROAD
SOUTHWEST FLOW ALOFT AND POTENTIAL FOR AN AXIS OF DEEP CONVERGENCE
UP TO ABOUT 700MB ALL SUPPORT POTENTIAL FOR TORRENTIAL RAINFALL AND
EFFICIENT RATES LATE TONIGHT. COULD SEE AMOUNTS IN EXCESS OF 1-2
INCHES OVER FAR WESTERN FORECAST AREA. WILL BE INTRODUCING A FLASH
FLOOD WATCH FOR THE WABASH VALLEY THROUGH 12Z SUNDAY BECAUSE OF
THESE CONCERNS. WILL RAISE POPS TO LIKELY OVER THE EAST AND
CATEGORICAL OVER THE WEST LATE TONIGHT.
TEMPS...MOS GUIDANCE LOOKS REASONABLE AS LOW TEMPS WILL ONLY FALL
INTO THE UPPER 60S TO NEAR 70 WITH SATURATED LOWER LEVELS.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 353 PM EDT FRI MAY 31 2013
FORECAST CHALLENGES REMAIN ON HEAVY RAIN AND SEVERE WEATHER
POTENTIAL THROUGH SATURDAY NIGHT AS THE COLD FRONT TRACKS SLOWLY
THROUGH THE REGION.
POTENTIAL FOR A SCENARIO SIMILAR TO THIS MORNING TO PLAY OUT
SATURDAY MORNING AS REGION MAY RESIDE UNDERNEATH A THICK CLOUD
CANOPY WITHIN A STABLE ENVIRONMENT IN WAKE OF OVERNIGHT CONVECTION.
THAT PRESENTS CHALLENGES ONCE AGAIN AS TO WHETHER ANY SUBSTANTIAL
HEATING CAN TAKE PLACE THROUGHOUT THE DAY AND ULTIMATELY HOW
UNSTABLE THE AIRMASS CAN GET BY AFTERNOON. THE UPPER LEVEL DYNAMICS
ARE ARGUABLY BETTER WITH CENTRAL INDIANA REMAINING IN THE RIGHT REAR
QUAD OF THE 100KT UPPER JET WITH UPPER DIFFLUENCE AHEAD OF THE WAVE
ALOFT ENHANCING CONVECTIVE DEVELOPMENT. ADDITIONALLY...LOW LEVEL JET
WILL PERSIST ACROSS THE REGION ALL DAY WITH PRECIP WATER VALUES
REMAINING ABOVE 1.50-1.75 IN. THE QUESTION MARK AGAIN IS WHETHER
INSTABILITY WILL BE HAMPERED BASED ON CLOUD COVER AND ADDITIONAL
CONVECTIVE DEVELOPMENT AS THE DAY PROGRESSES. WHILE ISOLATED
DAMAGING WINDS FROM STORMS CANNOT BE RULED OUT...CONFIDENCE REMAINS
LOW IN A LARGER SCALE SEVERE WEATHER EVENT SATURDAY AFTERNOON AND
EVENING BASED ON FACTORS MENTIONED ABOVE.
AT THIS POINT...CONCERN IS ONCE AGAIN GREATER TOWARDS HEAVY RAINFALL
WITH DEEP MOISTURE REMAINING AND THE PRESENCE OF THE LOW LEVEL JET
AND SUBSEQUENT CONVERGENCE THROUGH THE BOUNDARY LAYER. COULD EASILY
SEE REPEATED ROUNDS OF STORMS THROUGHOUT THE DAY OR POSSIBLY ANOTHER
MCS LATER IN THE AFTERNOON AND EVENING AS THE UPPER LEVEL SUPPORT
MOVES IN FROM THE WEST. THE POTENTIAL FOR ANOTHER 1-2 INCHES OF
RAINFALL IS POSSIBLE INTO SATURDAY EVENING. DEPENDING ON HOW THE
CONVECTIVE PATTERN EVOLVES TONIGHT AND INTO SATURDAY...THE FLASH
FLOOD WATCH MAY NEED TO BE EXPANDED FURTHER EAST ACROSS THE FORECAST
AREA.
MODEL GUIDANCE CONSISTENT IN BRINGING THE UPPER TROUGH AXIS AND COLD
FRONT ACROSS THE REGION LATE SATURDAY NIGHT WITH WIDESPREAD RAINFALL
SHIFTING EAST. HAVE HELD ONTO SLIGHT CHANCE POPS SUNDAY AS A WEAK
SHORTWAVE ALOFT MOVES ACROSS THE OHIO VALLEY AND INTERACTS WITH THE
COLD POOL IN WAKE OF THE FRONTAL PASSAGE. EXPECT JUST ISOLATED
SHOWERS AS MODEL SOUNDINGS SHOW LIMITED INSTABILITY. REMAINDER OF
THE SHORT TERM WILL BE QUIET AS A LARGE AREA OF HIGH PRESSURE BUILDS
IN WITH COOLER AND MUCH DRIER AIR.
TEMPS...WITH THE EXPECTATION OF CLOUD COVER AND WIDESPREAD PRECIP
COVERAGE ON SATURDAY...FELT MAVMOS GUIDANCE TOO WARM WITH TEMPS IN
THE MID 80S. UNDERCUT BY SEVERAL DEGREES AND KEEPING MUCH OF THE
FORECAST AREA IN THE 70S. COOLER AIR EXPANDS INTO THE REGION SUNDAY
AND MONDAY WITH TEMPS FALLING BACK INTO THE UPPER 60S/LOWER 70S BY
MONDAY. MOS LOOKED REASONABLE FOR OVERNIGHT LOWS. COULD SEE SOME
UPPER 40S IN RURAL LOCALES NORTH OF INDY METRO MONDAY MORNING.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ISSUED AT 256 PM EDT FRI MAY 31 2013
FAIRLY QUIET START TO THE LONG TERM PERIOD WITH BROAD SURFACE HIGH
PRESSURE OVER THE AREA. AN UPPER LEVEL SYSTEM WILL PUSH ACROSS THE
NORTHERN PLAINS...AND MAY BRING SOME THUNDERSTORMS TO THE AREA
BEGINNING AS EARLY AS WEDNESDAY NIGHT...WITH CHANCES INCREASING
TOWARD THE END OF THE WEEK. ALLBLEND HANDLED THIS WELL AND
REQUIRED FEW TWEAKS.
INITIALIZED TEMPERATURES WERE FAIRLY CLOSE...AGAIN WITH ONLY A FEW
MINOR TWEAKS REQUIRED. SHOULD SEE A SLIGHT WARMING TREND THROUGH
THE WEEK...WITH TEMPERATURES IN THE 80S MAKING A RETURN TO THE
AREA LATE IN THE WEEK.
&&
.AVIATION /DISCUSSION FOR 010000Z TAF ISSUANCE/...
ISSUED AT 703 PM EDT FRI MAY 31 2013
SOME MVFR CLOUDS OVER THE SITES CURRENTLY BUT THESE SHOULD LESSEN
WITH SUNSET AND VFR SHOULD BE THE RULE FOR A COUPLE OF HOURS. A LINE
OF THUNDERSTORMS CURRENTLY OVER WESTERN ILLINOIS WILL MOVE INTO THE
AREA STARTING AROUND 3-4Z OR SO AT KLAF AND THEN OVERSPREAD THE
OTHER SITES WITHIN A FEW HOURS. HRRR SHOWS THESE STORMS HANGING
AROUND THE SITES FOR SEVERAL HOURS AND NOT REALLY MOVING OFF TO THE
EAST UNTIL AFTER 12Z SATURDAY. WITH GRIDDED FORECAST ALSO SHOWING
LIKELY OR GREAT THUNDER CHANCES WILL GO WITH PREVAILING THUNDER FROM
ARRIVAL THROUGH MORNING. AFTER THAT WILL INCLUDE A PROB30 WITH GRIDS
STILL SHOWING LIKELY OR GREATER THUNDER CHANCES BUT THE EXPECTATION
THAT THERE WILL BE SOME SORT OF LULL IN THE MORNING BEFORE
THUNDERSTORMS FIRE UP AGAIN IN THE AFTERNOON. THUS WITH VERY HIGH
POPS AND THOUGHT THAT THUNDER WILL REFIRE IN THE AFTERNOON BROUGHT
PREVAILING THUNDER BACK IN AFTER 18Z. FAIRLY UNCERTAIN ABOUT WIND
GUSTS THROUGH THE OVERNIGHT. THINK THEY WILL NOT BE CONSTANT BUT
SHOULD PICK BACK UP IN/AROUND THUNDERSTORMS SO WILL ALLOW THESE TO
BE PREVAILING FOR MUCH OF THE NIGHT AS WELL. MAY DROP OFF IN THE
MORNING BEFORE PICKING BACK UP WITH GUSTS OF 20-25 KTS OUT OF THE
SOUTHWEST AGAIN IN THE AFTERNOON.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH SUNDAY MORNING FOR INZ028-029-035-036-
043>045-051>053-060-061-067>069.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....NIELD
AVIATION...CP
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AREA FORECAST DISCUSSION
NWS DES MOINES IA
1243 PM CDT FRI MAY 31 2013
.SHORT TERM.../TODAY /...
ISSUED AT 323 AM CDT FRI MAY 31 2013
THUNDERSTORMS HAVE DEVELOPED IN NORTHERN MISSOURI ALONG A ZONE OF
WARM AIR ADVECTION AND A LOW LEVEL JET. JUST NORTH OF THAT AREA BUT
STILL IN MO SOME WEAKER STORMS HAVE DEVELOPED AND ARE DISSIPATING.
THE STORMS HAVE AN EAST/NORTHEASTERLY TRACK AND WILL EVENTUALLY CLIP
FAR SOUTHERN IOWA. THE WEAKENING STORMS JUST ACROSS OUR BORDER WILL
LIKELY ONLY PRODUCE SOME SHOWERS ACROSS THE FAR SOUTH IN THE NEXT
FEW HOURS. A VORT MAX AND SHORT WAVE WILL PIVOT AROUND THE UPPER
LOW OVER THE EASTERN DAKOTAS AND THIS WILL SHIFT THE STORMS THAT ARE
A LITTLE FURTHER SOUTH IN NORTHERN MO RIGHT INTO SOUTHERN/SOUTHEAST
IOWA BY MID TO LATE MORNING THEN INTO EASTERN IOWA BY EARLY
AFTERNOON.
BY MID TO LATE AFTERNOON A STRONGER SHORT WAVE WILL PUSH INTO
WESTERN IOWA WHICH WILL BRING MORE THUNDERSTORMS TO THAT AREA AND
THIS WILL SHIFT EAST FROM 21Z INTO THE EVENING HOURS. THERE WILL BE
A TIME IN THE AFTERNOON WHERE SHOWERS AND STORMS WILL STILL BE OVER
EASTERN IOWA AND ADDITIONAL STORMS DEVELOPING OVER THE WEST WITH
CENTRAL IOWA DRY. LAPSE RATES OVER SOUTHERN IOWA AND ABOUT THE
SOUTHEAST THIRD OF THE STATE ARE PRETTY STEEP THIS AFTERNOON AND
THERE IS MORE THAN SUFFICIENT SHEAR FOR A FEW SEVERE STORMS. IN
ADDITION...HEAVY RAINFALL IS LIKELY WITH THE STORMS AS WELL...MAINLY
OVER THE FAR EAST AND SOUTHEAST.
YESTERDAY THE HI RES NMM EAST REALLY HAD THE PRECIP AREAS PEGGED AND
ALSO HAD DECENT TIMING OF THE PRECIP. I STILL LIKE WHAT THIS MODEL
DOES WITH THE PRECIP TODAY HOWEVER IT IS NOT PICKING UP THE MO
CONVECTION VERY WELL AT THIS TIME. IT IS ABOUT 3 HOURS LATER WITH
THAT SO I BLENDED NMM POPS WITH THE HRRR AND NAM12.
AS FOR TEMPS...THERE SHOULD BE SLIGHTLY WARMER AIR OVER THE SOUTH
AND SOUTHEAST TODAY SO I NUDGED HIGHS UP IN THESE AREAS. THE NORTH
SHOULD SEE TEMPS A FEW DEGREES WARMER AS WELL.
.LONG TERM.../TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 323 AM CDT FRI MAY 31 2013
FEWER CONCERNS FOR THE NEXT SEVERAL DAYS AS UPPER TROUGH BEGINS TO
SWING EAST. ALREADY THE MAIN H850 MOISTURE CHANNEL HAS SHIFTED EAST
OF THE AREA WITH THE LINE OF STRONGER THUNDERSTORMS THAT EXITED THE
EASTERN PORTION OF THE FORECAST AREA EARLY THIS EVENING. HOWEVER
THERE WILL STILL BE SOME RESIDUAL CONVECTION FAR SOUTHEAST EARLY IN
THE PERIOD TONIGHT...ENDING QUICKLY AND MOVING EAST BY 06Z.
MEANWHILE...THE MAIN FEATURE YET LATE TONIGHT AND EARLY SATURDAY
WILL BE THE OLD H500 LOW WHICH IS LIKELY TO SPIN UP SOME SHOWERS AND
ISOLATED THUNDER AS IT MOVES ACROSS THE REGION TOMORROW AS THE COLD
POOL UNDERNEATH THE UPPER LEVEL LOW DROPS SOUTHEAST INTO THE REGION.
STEEP LAPSE RATES WILL BE IN THE AREA OF THE LOW ON SATURDAY AND
OVER THE NORTH INTO MN AND WESTERN WI NON SUPERCELL TORNADO PARAMETER
IS INCREASING. SOMETHING TO KEEP AN EYE ON THERE...AN ISOLATED
FUNNEL CLOUD OR LANDSPOUT MAY BE POSSIBLE IF LAPSE RATES BECOME
STEEP ENOUGH IN THE AFTERNOON HOURS. OTHERWISE...THE OLD LOW WILL
PULL EAST SATURDAY NIGHT AND SUNDAY LEAVING THE REGION WITH COOLER
AIR FOR THE FIRST PART OF JUNE. THIS WILL KEEP THE AREA IN THE 60S
FOR HIGHS ON SUNDAY WITH MID 40S NORTH AND LOWER 50S SOUTH FOR LOWS
ON MONDAY MORNING. AS THE HIGH MOVES EAST...HIGHS WILL RESPOND INTO
THE LOWER 70S FOR MONDAY. MONDAY NIGHT WARM AIR ADVECTION AND MID
LEVEL MOISTURE BEGIN TO INCREASE AGAIN...RESULTING IN LATE
NIGHT/EARLY MORNING ELEVATED CONVECTION. TUESDAY LOOKS ACTIVE AS A
STRONGER WAVE ROTATES NORTHEAST INTO THE STATE. THIS WILL RESULT IN
MORE WIDESPREAD THUNDERSTORMS WITH RAINFALL AMOUNTS POSSIBLY
APPROACHING ONE INCH IN SOME PLACES. THIS WILL CERTAINLY KEEP SOIL
MOISTURE HIGH...AND ALSO RESULT IN RENEWED RIVER RISES. THE SYSTEM
WILL GRADUALLY EXIT THE REGION BY THURSDAY. THE LARGER SCALE FLOW
PATTERN REMAINS GENERALLY WESTERLY AT MID TO HIGH LEVELS. THIS
PROMOTES LEE SIDE TROUGHING AND WITH A CONTINUED SUB TROPICAL HIGH
ANCHORED OFF THE EAST COAST A WETTER THAN NORMAL PATTERN IS LIKELY
TO CONTINUE OVER THE NEXT 7 TO 10 DAYS. ANOTHER INTERESTING WRINKLE
IS A TROPICAL DISTURBANCE IN THE GULF OF MEXICO BY NEXT THUR/FRIDAY
WHICH MAY EVENTUALLY BE PULLED NORTH TOWARD THE MID MISSISSIPPI
RIVER VALLEY. HIGH TEMPERATURES OVER THE NEXT WEEK WILL LIKELY
REMAIN IN THE 70S ON AVERAGE AND NOT BREAK OUT OF A 65 TO 75 RANGE
BY TOO MUCH IF ANY. ANOTHER NOTE WITH OUR CURRENT WET WEATHER WILL
BE CLOUD COVER. UNLESS WE HAVE A STRONG HIGH AND STRONG
SUBSIDENCE...MOST LATE MORNINGS AND AFTERNOONS ON ANY SUNNY DAY WILL
GO SCT TO BKN BY AFTERNOON.
&&
.AVIATION...31/18Z
ISSUED AT 1245 PM CDT FRI MAY 31 2013
A FEW SHOWERS AND THUNDERSTORMS STRETCHING ACROSS THE EASTERN
CWA...SHOULD MAINLY IMPACT KALO AND KOTM THROUGH MID AFTERNOON. A
FEW SCATTERED SHOWERS/ISOLATED THUNDERSTORMS MAY ALSO DEVELOP
ACROSS THE NORTH TOWARD LATE AFTERNOON POSSIBLE IMPACTING KFOD AND
KMCW. OTHERWISE MAINLY DRY CONDITIONS TONIGHT...WITH SOUTHERLY TO
SOUTHWESTERLY WINDS BECOMING WESTERLY TO NORTHWESTERLY SATURDAY.
MVFR TO LOW VFR CLOUDS EXPECTED TO IMPACT ENTIRE CWA SATURDAY AS
MAIN UPPER LEVEL SYSTEM CURRENTLY ACROSS THE DAKOTAS MOVES THROUGH
THE STATE.
&&
.HYDROLOGY...
ISSUED AT 323 AM CDT FRI MAY 31 2013
A FLASH FLOOD WATCH REMAINS IN EFFECT FOR BUTLER COUNTY AT THIS
TIME DUE TO THE SMALL BREACH IN THE LEVEE ALONG THE BEAVER CREEK
AT NEW HARTFORD.
A WEATHER DISTURBANCE CAUSING AN AREA OF THUNDERSTORMS FROM KANSAS
AND MISSOURI WILL ROTATE NORTHEAST TODAY...AFFECTING THE SOUTHEAST
HALF OF THE FORECAST AREA LATER THIS MORNING THROUGH THE AFTERNOON
HOURS. THE SOUTHEAST MAY SEE UP TO AN INCH OR MORE OF RAIN...BUT
CURRENT FLASH FLOOD GUIDANCE HAS INCREASED TO 1.3 TO 1.5 INCHES
PER HOUR AND 1.5 TO 2.25 INCHES IN 3 HOURS AT PRESENT. UNLESS THE
STORMS BACK BUILD...THE RISK FOR ANY FLASH FLOODING REMAINS LOW
TODAY ACROSS OUR FORECAST AREA.
RIVER FLOOD WARNINGS REMAIN IN EFFECT FOR NUMEROUS LOCATIONS
THROUGHOUT THE HYDROLOGICAL SERVICES AREA FOR THE NEXT 5 TO 6 DAYS.
IN THE SHORT TERM... THE OLD H500 LOW WILL CYCLE EAST IN THE NEXT 24
TO 48 HOURS AND THEN DEPART. WITH ONLY LIGHT SHOWERS OR ISOLATED
THUNDER EXPECTED... RAINFALL WILL REMAIN LIGHT. FOLLOWING
THAT...HIGH PRESSURE WILL KEEP THE REGION RAIN FREE TO MONDAY
EVENING. THIS WILL SLOWLY ALLEVIATE THE SOME OF THE WATER ISSUES
THOUGH LARGER MAIN STEM RIVER SYSTEMS WILL REMAIN ABOVE FLOOD STAGE
THROUGH THE FORECAST PERIOD. ADDITIONAL MODERATE RAINFALL IS LIKELY
BEGINNING LATE MONDAY NIGHT THROUGH THURSDAY WHICH WILL NEED TO BE
WATCHED.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 7 PM CDT THIS EVENING FOR SOUTHEASTERN BUTLER.
&&
$$
SHORT TERM...FAB
LONG TERM...REV
AVIATION...BEERENDS
HYDROLOGY...REV
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1231 PM CDT FRI MAY 31 2013
.UPDATE...
ISSUED AT 1220 PM CDT FRI MAY 31 2013
THE TWO SEPARATE MCS COMPLEXES HAVE MERGED AS EXPECTED. THUS THE
SOUTHEAST HALF OF THE CWFA HAS THE BETTER CHANCE AT SEEING
MODERATE RAIN WITH POSSIBLY VERY LOCALIZED HEAVY RAINFALL THROUGH
THE AFTERNOON HOURS.
NEW CONVECTION HAS DEVELOPED IN CENTRAL IOWA DUE TO CONVERGENCE OF
THE WIND FIELD. THE MCS/LIFT TOOLS ARE SUGGESTING THIS NEW
CONVECTION WILL MOVE INTO THE NORTHWEST PART OF THE CWFA BUT MAY
REMAIN WEAK. THE MCS MAY INDUCE NEW CONVECTION IN FAR NORTHWEST
ILLINOIS IN AREAS ALONG/EAST OF THE MISSISSIPPI.
THE KEY TO CONVECTIVE TRENDS THIS AFTERNOON WILL BE WHETHER OR NOT
CONVECTIVE TEMPERATURE IS ACHIEVED. FORECAST SOUNDINGS PLACE THE
CONVECTIVE TEMPERATURE IN THE UPPER 70S WHICH IS THE CURRENT FCST
MAX TEMPERATURE FOR MUCH OF THE AREA. STRONGER STORMS MAY BE
POSSIBLE IF STRONGER DIFFERENTIAL HEATING CAN OCCUR ACROSS THE
AREA. ..08..
UPDATE ISSUED AT 1036 AM CDT FRI MAY 31 2013
MCS TOOL FROM THE UKMET AND RAP ARE DEPICTING REASONABLY WELL THE
CURRENT WX. THE FIRST MCS IS MOVING ACROSS THE SOUTHERN CWFA
PRODUCING LIGHT TO MODERATE RAIN. SLIGHTLY DRIER AIR MIXING DOWN
ON THE NORTH SIDE IS RESULTING IN A BRIEF PERIOD OF HIGH WINDS.
THE TRENDS WITH THE RAP MODEL INDICATE THE NEW MCS ACROSS NORTHERN
MISSOURI WILL SLOWLY MERGE WITH THE FIRST MCS THROUGH LATE
MORNING. THE SOUTHEAST HALF OF THE CWFA WILL BE AFFECTED BY THE
COMBINED MCS WITH IT EXITING THE CWFA BY EARLY EVENING. THUS THIS
AREA WILL SEE THE MORE WIDESPREAD AND POTENTIALLY HEAVY RAINFALL.
FLOW BASED OFF THE SFC OBS THROUGH 15Z INDICATE THE CLEAR AREAS
ACROSS CENTRAL/NORTHERN IOWA WILL FILL WITH CLOUDS AS THE MORNING
AND AFTERNOON PROGRESS. THE LIFT TOOL SUGGESTS THE POTENTIAL FOR
NEW CONVECTION DEVELOPING AHEAD OF THE APPROACHING FRONT.
AS FOR THE FLASH FLOOD HEADLINES...THEY ARE BEING LEFT IN PLACE
FOR NOW. DEPENDING UPON HOW CONVECTION EVOLVES DURING THE LATE
MORNING AND AFTERNOON...THE POSSIBILITY EXISTS THAT SOME HEADLINES
MAY BE DROPPED. ..08..
UPDATE ISSUED AT 642 AM CDT FRI MAY 31 2013
IMPULSE MOVING AROUND THE BASE OF THE TROUGH WAS PUSHING INTO NW
MO AND WILL BE HEADING NORTHEAST INTO THE DVN CWA LATER THIS
MORNING. RAP MODEL INCREASES THE LOW LEVEL JET SO THUNDERSTORMS
SHOULD CONTINUE TO SPREAD NORTHEAST INTO THE CWA THIS MORNING AND
THEN INCREASE IN COVERAGE/INTENSITY THIS AFTERNOON.
&&
.SYNOPSIS...
ISSUED AT 315 AM CDT FRI MAY 31 2013
ALL IS QUIET FOR NOW ACROSS THE DVN CWA EARLY THIS MORNING BUT
THUNDERSTORMS WERE LINED UP FROM NORTHEAST IL INTO AR MOVING
NORTHEAST. OTHER THUNDERSTORMS WERE FORMING IN EXTREME NW MO AND
NORTHEAST KS. A SUPERCELL WAS PRODUCING LARGE HAIL AROUND TOPEKA
AND THESE STORMS WERE SPREADING EAST/NORTHEAST AT 40 KNOTS. STRONG LOW
PRESSURE WAS SPINNING OVER THE DAKOTAS WITH A COLD FRONT IN THE
PLAINS. CURRENT TEMPERATURES WERE IN THE 60S ACROSS IA...MO...KS
AND IN THE 70S IN THE SOUTHERN PLAINS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 315 AM CDT FRI MAY 31 2013
HEADLINES...WILL CONTINUE THE FLASH FLOOD WATCH TODAY THROUGH
TONIGHT.
FORECAST FOCUS ON ACTIVE SEVERE WEATHER TODAY INTO THIS EVENING
AND POTENTIAL FOR FLASH FLOODING ESPECIALLY WHERE TRAINING STORMS
OCCUR.
TODAY...SHOULD BE JUST ENOUGH SUNSHINE THIS MORNING TO PUSH
TEMPERATURES INTO THE LOWER TO MID 70S THIS MORNING WITH THE
CONVECTIVE TEMPERATURE REACHED. THUNDERSTORM ACTIVITY TO OUR
SOUTHWEST SHOULD QUICKLY PUSH INTO THE DVN CWA THIS MORNING.
AIR MASS WILL BE DESTABILIZING ALLOWING FOR THUNDERSTORMS TO
INTENSIFY. MODERATE TO STRONG DEEP LAYER SHEAR AND DRY AIR ALOFT
AND FREEZING LEVEL AT 11-12K FT SHOULD BE IDEAL FOR LARGE HAIL
LATER THIS MORNING...POTENTIALLY QUARTER TO GOLF BALL SIZE.
THIS AFTERNOON...WINDS ALOFT BECOME MORE UNIDIRECTIONAL WITH MID
LEVEL WINDS INCREASING TO OVER 70 KNOTS. THIS WOULD FAVOR BOWING
SEGMENTS AND DAMAGING WINDS GREATER THAN 70-80 MPH. WITH THE
GROUND SATURATED THIS WOULD EASILY KNOCK OVER LARGE TREES. WITH
SUCH STRONG SHEAR ANY DISCRETE THUNDERSTORM MAY BECOME
SUPERCELLULAR WITH THE POTENTIAL FOR TORNADOES/LARGE HAIL...ALSO
IN ANY LEWP/BOWING SEGMENTS. THUNDERSTORMS WILL BE FAST MOVING BUT
ANY TRAINING OF STORMS WOULD ENHANCE THE FLASH FLOOD THREAT.
OPERATIONAL MODELS SUGGEST THE HIGHEST RAIN TOTALS TO BE ACROSS
ABOUT OUR SOUTHEAST HALF CWA. HIGHS TODAY AROUND 80.
TONIGHT...ACTIVE THUNDERSTORMS THIS EVENING SHOULD BE MAINLY IN
OUR IL COUNTIES WITH ACTIVITY THEN PUSHING EAST OF THE DVN CWA BY
MIDNIGHT. COLD FRONT WILL BE MOVING INTO EASTERN IA LATER TONIGHT
BRINGING COOLER AND DRIER AIR INTO EASTERN IA. MINIMUM TEMPERATURES
WILL RANGE FROM THE UPPER 50S WEST TO MID 60S EAST.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 315 AM CDT FRI MAY 31 2013
SATURDAY...THE SURFACE COLD FRONT IS PROGGED TO BE NEAR THE
MISSISSIPPI RIVER AT 12Z SATURDAY. THE COLD FRONT WILL CONTINUE TO
SLIDE EAST DURING THE DAY AS THE UPPER TROUGH AXIS SHIFTS EAST
ACROSS IOWA. THE CHANCE FOR SOME SHOWERS AND STORMS WILL CONTINUE IN
THE VICINITY OF THE SURFACE FRONT EARLY SATURDAY. WILL HOLD ONTO
SOME SLIGHT TO CHANCE CATEGORY PRECIPITATION PROBABILITIES THROUGH
THE REMAINDER OF SATURDAY AS THE MID LEVEL BOUNDARY AND UPPER TROUGH
ENERGY WORK ACROSS THE FORECAST AREA. HOWEVER ANY SHOWERS OR STORMS
ON SATURDAY WILL BE LACKING IN HEAVY RAIN OR SEVERE POTENTIAL.
TEMPERATURES SATURDAY ARE A BIT OF A CHALLENGE WITH CLOUD COVER AND
COLDER AIR STARTING TO WORK IN BEHIND THE FRONT.
SUNDAY THROUGH MONDAY...A BRIEF RESPITE IN THE ACTIVE WEATHER
PATTERN IS IN STORE FROM SUNDAY INTO MONDAY. COOLER AND DRIER AIR
WILL MOVE IN AS UPPER RIDGING AND SURFACE HIGH PRESSURE SPREAD
ACROSS THE REGION. TEMPERATURES ON SUNDAY LOOK TO BE AROUND 10
DEGREES BELOW NORMAL...WITH MORNING LOWS IN THE LOWER TO MIDDLE 50S
AND HIGHS IN THE MIDDLE TO UPPER 60S. MONDAY MORNING TEMPERATURES
COULD BOTTOM OUT IN THE 40S ACROSS PORTIONS OF THE FORECAST AREA.
TUESDAY THROUGH THURSDAY...YET ANOTHER UPPER LEVEL SYSTEM WILL
APPROACH THE MIDWEST MID TO LATE NEXT WEEK. LEAD SHORTWAVE ENERGY
COULD KICK OFF SOME PRECIPITATION AS EARLY AS TUESDAY...WITH
INCREASING SHOWER AND THUNDERSTORM CHANCES BY WEDNESDAY. A WARMING
TREND WILL BRING TEMPERATURES BACK CLOSER TO NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1220 PM CDT FRI MAY 31 2013
TWO SEPARATE THUNDERSTORM COMPLEXES HAVE MERGED OVER SOUTHEAST
IOWA AND WESTERN ILLINOIS. GENERALLY VFR WX WILL BE SEEN THROUGH
00Z/01. TSRA WILL BE POSSIBLE WITH KMLI/KBRL HAVING A BETTER
CHANCE THAN KCID/KDBQ. IF A TSRA AFFECTS A TAF SITE A BRIEF PERIOD
OF MVFR CONDITIONS ARE POSSIBLE. AFT 00Z/01 VFR CONDITIONS ARE
EXPECTED TO CONTINUE. WET GROUND MAY RESULT IN MVFR CONDITIONS
DVLPG AFT 06Z/01 DUE TO MAINLY CLEAR SKIES AND WINDS UNDER 10
KNOTS. ..08..
&&
.HYDROLOGY...
ISSUED AT 315 AM CDT FRI MAY 31 2013
WITH MANY RIVERS IN MODERATE TO MAJOR FLOOD AND THE GROUND
COMPLETELY SATURATED THE THREAT FOR FLASH FLOODING WILL REMAIN
TODAY INTO THIS EVENING...ESPECIALLY WHERE TRAINING OF STORMS
OCCUR. THE HEAVIEST RAINS SHOULD BE ACROSS THE SOUTHEAST HALF OF
THE DVN CWA WHERE MANY AREAS SHOULD RECEIVE AT LEAST AN INCH OF
RAIN TODAY INTO THIS EVENING. HOWEVER...SEVERAL INCHES OF RAIN
WOULD PRODUCE SEVERE FLASH FLOODING ESPECIALLY IF STORMS CAN TRAIN
ACROSS THE SAME LOCATIONS.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR BENTON-BUCHANAN-
CEDAR-CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-IOWA-
JACKSON-JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-
MUSCATINE-SCOTT-VAN BUREN-WASHINGTON.
IL...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR BUREAU-CARROLL-
HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER-
PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE.
MO...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR CLARK-SCOTLAND.
&&
$$
UPDATE...08
SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...STOFLET
AVIATION...08
HYDROLOGY...HAASE
AREA FORECAST DISCUSSION
NWS GOODLAND KS
207 PM MDT FRI MAY 31 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 152 PM MDT FRI MAY 31 2013
EARLY AFTERNOON WV IMAGERY AND RAP H5 ANALYSIS SHOW LARGE SCALE
TROUGH STILL IN PLACE ACROSS NORTHERN PLAINS WITH CLOSED CENTER
OVER THE EASTERN DAKOTAS. A SERIES OF WEAK VORTICITY MAXIMA ARE
ROTATING AROUND THE WESTERN EXTENT OF THE UPPER LOW PRODUCING
MID-HIGH CLOUDS ACROSS THE PLAINS. OVER THE SOUTHERN PART OF OUR CWA
STEEP LAPSE RATES ALONG A BAROCLINIC ZONE HAS LED TO DEVELOPMENT OF
HIGH BASED SHOWERS/VIRGA. WITH BASES GENERALLY AROUND 12KFT AND A
DEEP DRY LAYER BELOW THIS...IT IS UNLIKELY MUCH MORE THAN A FEW
SPRINKLES WILL REACH THE SURFACE WITH THIS ACTIVITY.
RED FLAG CONDITIONS AND GUSTY WINDS SHOULD CONTINUE THROUGH THE EARLY
EVENING PERIOD ACROSS NW HALF OF THE CWA. LIMITING FACTOR FOR RFW
CONTINUES TO BE FUELS...AND WITHOUT FURTHER INFORMATION IN THIS
REGARD I DECIDED AGAINST EXPANDING CURRENT WARNING. WINDS HAVE
OCCASIONALLY HIT ADVISORY CRITERIA IN THE NW...HOWEVER THESE
CONDITIONS HAVE BEEN SPORADIC...SO IVE LEANED AGAINST ISSUANCE OF
WIND ADVISORY.
TONIGHT A SHORTWAVE TROUGH WILL ROUND THE BASE OF THE LARGE SCALE
UPPER LOW WITH A COLD FRONT DROPPING SOUTH OVER OUR CWA (06 TO 09Z).
WHILE WINDS MAY DECREASE SOME AFTER SUNSET...THE LULL IN WINDS THIS
EVENING WILL BE SHORT LIVED BEFORE NEAR ADVISORY LEVEL WINDS
REDEVELOP AFTER MIDNIGHT AND CONTINUE THROUGH THE DAY SATURDAY
BEHIND THE FROPA. SOME GUIDANCE IS ALSO SHOWING BETTER MID LEVEL
MOISTURE WITH THIS UPPER LEVEL TROUGH ROTATING INTO THE
CWA...HOWEVER THE BEST LIFT IS OUTSIDE OUR CWA...AND MODELS NEVER
INITIATE SHOWERS OVER OUR CWA WITH DRY LOW LEVELS STILL IN PLACE.
OTHER THAN THICKENING CLOUD COVER...I AM NOT EXPECTING ANY PRECIP.
OVERNIGHT LOWS TONIGHT WILL DROP TO THE LOW 40S IN EASTERN COLORADO
TO THE LOW 50S IN NORTH CENTRAL KANSAS. CONSIDERING THE COOL NATURE
OF THE AIR MASS WE WOULD BE LOOKING AT MUCH COLDER TEMPS IF IT WASNT
FOR CLOUD COVER AND WINDS OVERNIGHT. HIGHS ON SATURDAY MAY STRUGGLE
TO REACH THE UPPER 60S/70F IF CLOUD COVER FAILS TO CLEAR BY THE
AFTERNOON AS CURRENTLY ADVERTISED.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 152 PM MDT FRI MAY 31 2013
FOR SATURDAY NIGHT THROUGH SUNDAY NIGHT...THE UPPER LEVEL RIDGE WILL
BEGIN TO MOVE OVER THE AREA SATURDAY NIGHT AS A SURFACE HIGH MOVES
INTO THE AREA. SUNDAY THE SURFACE HIGH WILL SLIDE EAST. AS IT DOES
SO A TIGHT PRESSURE GRADIENT WILL DEVELOP OVER THE AREA FROM WEST TO
EAST BEHIND THE EXITING SURFACE HIGH. WINDS WILL BREEZY BUT WILL
DECLINE BEFORE SUNSET AS TEMPERATURES COOL. SUNDAY EVENING AS THE UPPER
LEVEL RIDGE AXIS MOVES EAST OF THE AREA A SHORT WAVE TROUGH WILL
MOVE ACROSS THE AREA. POINT SOUNDINGS SHOW A VERY SMALL AMOUNT OF
ELEVATED INSTABILITY OVER THE SOUTHWEST PART OF THE AREA AS THE
SHORT WAVE MOVES THROUGH. AT THIS TIME WILL KEEP THE FORECAST DRY DUE
TO LOW CONFIDENCE THAT ANY STORMS WILL DEVELOP GIVEN THE ELEVATED
CAPE IS LESS THAN 200 J/KG...AND THE DEEP DRY LAYER EXTENDING UP TO
600MB OR SO WHICH WILL CAUSE ANY LIGHT RAIN THAT MAY DEVELOP TO
EVAPORATE.
MONDAY THROUGH FRIDAY AN UPPER LEVEL TROUGH WILL MOVE ACROSS THE
NORTHERN PLAINS. MODELS HAVE SHIFTED THE TRACK OF THE TROUGH
SLIGHTLY NORTH...BUT OVERALL THIS SEEMS TO HAVE LITTLE EFFECT ON
PRECIP. CHANCES FOR THE PERIOD. NUMEROUS SHORT WAVE TROUGHS THAT
EXTEND FROM THE MAIN FEATURE MOVE OVER THE AREA TROUGH THE PERIOD AS
THE TROUGH SLOWLY MOVES EAST OVER THE NORTHERN PLAINS. WITH EACH
SHORT WAVE TROUGH MOVING THROUGH THE AREA PRECIP. CHANCES WILL
RETURN.
TEMPERATURES FOR THE PERIOD WILL START OUT 10 DEGREES ABOVE NORMAL
MONDAY THEN COOL TO NEAR NORMAL TUESDAY THROUGH FRIDAY AS A COLD
FRONT MOVES THROUGH THE AREA SOMETIME ON TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1120 AM MDT FRI MAY 31 2013
VFR CONDITIONS EXPECTED TO PREVAIL THROUGH THE TAF PERIOD AT BOTH
KGLD AND KMCK. WESTERLY WINDS GUSTING 35-39KT WILL DECREASE SOME
AFTER SUNRISE...WITH SUSTAINED WINDS 10-15KT THIS EVENING. WINDS
WILL INCREASE LATE TONIGHT (BY 09-10Z) AS A COLD FRONT MOVES
ACROSS THE REGION AND CONTINUE THROUGH SATURDAY MORNING. FOR NOW I
INCLUDED GUSTS 30-33KT...HOWEVER THERE IS INDICATION THAT WINDS
COULD BE STRONGER FOR A BRIEF PERIOD IMMEDIATELY BEHIND THE FRONT.
THERE COULD ALSO BE A FEW LIGHT SHOWERS AS THE FRONT MOVES ACROSS
THE AREA...HOWEVER WITH DEEP DRY LAYER IN PLACE IM NOT SURE IF
THERE WILL BE MUCH MORE THAN VIRGA WITHIN THE VICINITY OF EITHER
TERMINAL.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR KSZ013-027.
CO...RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ252>254.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JTL
AVIATION...DR
AREA FORECAST DISCUSSION
NWS JACKSON KY
601 PM EDT FRI MAY 31 2013
.UPDATE...
ISSUED AT 600 PM EDT FRI MAY 31 2013
BASED ON CURRENT RADAR WENT AHEAD AND INCREASED POPS FOR NORTHWESTERN
COUNTIES IN THE AERA...WITH THE POTENTIAL FOR SOME SCATTERED SHOWERS
OVER THE NEXT HOUR OR TWO ALONG THE FAR SOUTHWESTERN COUNTIES AS
WELL. THAT BEING SAID...LOOKING AT MODEL PARAMETERS...DYNAMICS SEEM TO BE
FAIRLY WEAK OVER MUCH OF EASTERN KY...AND HI RES MODEL /HRRR/ PRECIP
SHOWS A QUICK DIMINISHING TREND THROUGHOUT THE EVENING. TRIED TO
REFLECT THIS IDEA WITHIN THE POPS AND WX...WITH THE BEST CHANCE FOR
CONVECTION REMAINING OVER THE NORTHERN COUNTIES THROUGH THE EVENING.
BUT WITH VERY LITTLE LIGHTNING SHOWING UP ON RADAR AND WEAK
INSTABILITY IN OUR AREA...ONLY SLIGHT CHANCE OF THUNDER WAS
WARRANTED.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 320 PM EDT FRI MAY 31 2013
MESOSCALE CONVECTIVE VORTEX WHICH HAD BEEN NEAR MADISONVILLE KY AT
1230 PM HAS PULLED NORTHEAST AND IS NOW NEAR LOUISVILLE. STRONGEST
CONVECTION HAS BEEN OCCURRING AHEAD OF THIS FEATURE AND NOW PULLING
INTO SOUTHWEST OH. CONVECTION TRAILS SOUTH TO WEST OF LAKE CUMBERLAND
ALONG OLD OUTFLOW BOUNDARY. WITH THE MOVEMENT OF THIS CONVECTION NNE
IT HAS ONLY BEEN VERY SLOWLY NEARING THE SW PART OF FORECAST AREA.
HOWEVER...OUTFLOW FROM THIS COULD STILL SERVE AS TRIGGER FOR
CONVECTION OVER THE FAR WEST PART OF FORECAST AREA. THE HRRR HAS BEEN
PERSISTENT IN TRYING TO BRING CONVECTION INTO OUR AREA...WITH THE 17Z
RUN TRYING TO MOVE CONVECTION INTO THE AREA AFTER 22Z...AND THEN SLOWLY
DISSIPATING AS IT MOVES EAST. WITH THE MCV MOVING AWAY AND WITH LOSS
OF DAYTIME HEATING DO EXPECT ANY CONVECTION IN OUR AREA TO DECREASE
QUICKLY THIS EVENING AND WILL DROP SHOWERS AND THUNDERSTORMS FROM
FORECAST AFTER MIDNIGHT.
A SHORT WAVE MOVING OUT OF THE SOUTHERN PLAINS SHOULD TRIGGER MORE
CONVECTION OVER MO TONIGHT...WITH THE EFFECTS OF THIS REMAINING TO
OUR WEST OVERNIGHT INTO SATURDAY MORNING. SATURDAY WILL BRING A
CHANCE FOR MORE SHOWERS AND THUNDERSTORMS WITH ANY OUTFLOW
BOUNDARIES FROM OVERNIGHT CONVECTION TO OUR WEST POSSIBLY SERVING AS
TRIGGER FOR MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS ON SATURDAY.
IT IS STILL POSSIBLE SOME OF THE STORMS SATURDAY AFTERNOON AND
EVENING COULD BECOME SEVERE...WITH GREATER INSTABILITY DURING THE
AFTERNOON INTO THE EVENING.
MODELS HAVE TRENDED TOWARDS A QUICKER SOLUTION WITH CONVECTION AHEAD
OF THE COLD FRONT MOVING INTO THE AREA SATURDAY NIGHT. WE HAVE
FOLLOWED THIS IDEA WITH LIKELY SHOWER AND THUNDERSTORM PROBABILITIES
AREA WIDE FOR SATURDAY NIGHT.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 320 PM EDT FRI MAY 31 2013
A COLD FRONT SHOULD BE ABOUT READY TO ENTER THE FORECAST AREA FROM
THE NW AT THE START OF THE PERIOD...WITH SUPPORT FROM AN APPROACHING
UPPER TROUGH...AND A RIBBON OF HIGHER DEW POINTS OFF THE GULF ALONG
THE FRONT BEING ADVECTED ALONG BY A 30-40 KT LOW LEVEL FLOW JUST OFF
THE SURFACE. ALL THIS CONSIDERED...THERE WILL LIKELY BE AN ONGOING
CONVECTIVE EVENT...WITH MODELS SHOWING THE GREATEST LIKELIHOOD OF
THIS IN THE SE PART OF THE AREA. AS THE FRONT SLOWLY PUSHES INTO AND
THROUGH THE FORECAST AREA SUNDAY AND SUNDAY EVENING...THERE COULD
ALSO BE ADDITIONAL DEVELOPMENT...WITH THE GREATEST OPPORTUNITY FOR
THIS IN THE SE WHERE FROPA WILL OCCUR LAST. THE LAST OF ANY
LINGERING PRECIP SHOULD END SUNDAY NIGHT OR EARLY MONDAY AS THE
FRONT CONTINUES ON TO OUR SE.
HIGH PRESSURE OVER THE MIDWEST WILL SUPPLY NOTICEABLY DRIER AND
SOMEWHAT COOLER AIR EARLY IN THE WEEK UNDER WNW FLOW ALOFT. RIDGING
ALOFT WILL PASS OVER ON TUESDAY INTO WEDNESDAY...WITH THE SURFACE
HIGH SHIFTING EASTWARD. THIS WILL BRING A CONTINUATION OF DRY
WEATHER...BUT WITH WARMING ALREADY OCCURRING AND AN EVENTUAL
INCREASE IN SURFACE MOISTURE.
AFTER THIS...MODEL DIFFERENCES BETWEEN THE GFS AND ECMWF BECOME MORE
APPARENT LATE IN THE WEEK. THE ECMWF DEVELOPS AN UPPER RIDGE OVER
THE CAROLINAS...BUT THIS FEATURE IS LACKING IN THE OPERATIONAL GFS.
ALL MODELS INDICATE AN UPPER LOW HEADING EAST ALONG THE CANADIAN
BORDER AND INTO ONTARIO...WITH A SOUTHWARD EXTENDING TROUGH. THE 00Z
ECMWF DOES NOT ALLOW AS MUCH OF A SOUTHERN EXTENSION OF THIS TROUGH
DUE TO ITS CAROLINA RIDGE. THE RESULT IS THAT THE GFS DEVELOPS
CONVECTION OVER THE LOCAL AREA FROM WEDNESDAY ON. MEANWHILE...THE
ECMWF SHOWS LIGHT PRECIP ONLY ON THURSDAY AS THE TROUGH SCOOTS BY TO
OUR NORTH. THE GEM AND GFS ENSEMBLE MEAN SUPPORT THE OPERATIONAL
GFS...AND PREFER TO WEIGHT THE FORECAST TOWARD IT...WITH JUST A BIT
OF ECMWF INFLUENCE TO KNOCK THE POPS DOWN SLIGHTLY FROM WHERE THEY
WOULD OTHERWISE BE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 121 PM EDT FRI MAY 31 2013
CONVECTION IS CURRENTLY DEVELOPING ACROSS CENTRAL KY AND EXPECT
SCATTERED SHOWERS AND THUNDERSTORMS TO MOVE INTO THE WESTERN PART OF
THE FORECAST AREA BY MID TO LATE AFTERNOON. CURRENT INDICATIONS ARE
THAT ANY CONVECTION THAT MOVES INTO OR DEVELOPS OVER EASTERN KY WILL
DECREASE QUICKLY EARLY THIS EVENING. THERE IS CONSIDERABLE
UNCERTAINTY HOW FAR EAST ANY SHOWERS OR THUNDERSTORMS WILL
OCCUR...AND AT THIS TIME WILL NOT MENTION ANY THUNDER IN THE JKL OR
LOZ TAF. WILL GO WITH VCTS IN THE SME TAF. OUTSIDE OF ANY SHOWER OR
THUNDERSTORMS VFR CONDITIONS WILL PREVAIL FOR THE REMAINDER OF THE
DAY. ALSO EXPECT VFR CONDITIONS TO PREVAIL TONIGHT AS WELL. THE
EXCEPTION TO THIS WOULD BE ANY AREAS THAT RECEIVE RAIN TODAY WHERE
OVERNIGHT FOG WOULD BE POSSIBLE. VFR WILL PREVAIL AGAIN SATURDAY
MORNING...WITH SHOWERS AND THUNDERSTORMS AGAIN POSSIBLE SATURDAY
AFTERNOON. AN APPROACHING COLD FRONT WILL BRING WIDESPREAD SHOWERS
AND THUNDERSTORMS SATURDAY NIGHT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JMW
SHORT TERM...SBH
LONG TERM...HAL
AVIATION...SBH
AREA FORECAST DISCUSSION
NWS JACKSON KY
320 PM EDT FRI MAY 31 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 320 PM EDT FRI MAY 31 2013
MESOSCALE CONVECTIVE VORTEX WHICH HAD BEEN NEAR MADISONVILLE KY AT
1230 PM HAS PULLED NORTHEAST AND IS NOW NEAR LOUISVILLE. STRONGEST
CONVECTION HAS BEEN OCCURRING AHEAD OF THIS FEATURE AND NOW PULLING
INTO SOUTHWEST OH. CONVECTION TRAILS SOUTH TO WEST OF LAKE CUMBERLAND
ALONG OLD OUTFLOW BOUNDARY. WITH THE MOVEMENT OF THIS CONVECTION NNE
IT HAS ONLY BEEN VERY SLOWLY NEARING THE SW PART OF FORECAST AREA.
HOWEVER...OUTFLOW FROM THIS COULD STILL SERVE AS TRIGGER FOR
CONVECTION OVER THE FAR WEST PART OF FORECAST AREA. THE HRRR HAS BEEN
PERSISTENT IN TRYING TO BRING CONVECTION INTO OUR AREA...WITH THE 17Z
RUN TRYING TO MOVE CONVECTION INTO THE AREA AFTER 22Z...AND THEN SLOWLY
DISSIPATING AS IT MOVES EAST. WITH THE MCV MOVING AWAY AND WITH LOSS
OF DAYTIME HEATING DO EXPECT ANY CONVECTION IN OUR AREA TO DECREASE
QUICKLY THIS EVENING AND WILL DROP SHOWERS AND THUNDERSTORMS FROM
FORECAST AFTER MIDNIGHT.
A SHORT WAVE MOVING OUT OF THE SOUTHERN PLAINS SHOULD TRIGGER MORE
CONVECTION OVER MO TONIGHT...WITH THE EFFECTS OF THIS REMAINING TO
OUR WEST OVERNIGHT INTO SATURDAY MORNING. SATURDAY WILL BRING A
CHANCE FOR MORE SHOWERS AND THUNDERSTORMS WITH ANY OUTFLOW
BOUNDARIES FROM OVERNIGHT CONVECTION TO OUR WEST POSSIBLY SERVING AS
TRIGGER FOR MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS ON SATURDAY.
IT IS STILL POSSIBLE SOME OF THE STORMS SATURDAY AFTERNOON AND
EVENING COULD BECOME SEVERE...WITH GREATER INSTABILITY DURING THE
AFTERNOON INTO THE EVENING.
MODELS HAVE TRENDED TOWARDS A QUICKER SOLUTION WITH CONVECTION AHEAD
OF THE COLD FRONT MOVING INTO THE AREA SATURDAY NIGHT. WE HAVE
FOLLOWED THIS IDEA WITH LIKELY SHOWER AND THUNDERSTORM PROBABILITIES
AREA WIDE FOR SATURDAY NIGHT.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 320 PM EDT FRI MAY 31 2013
A COLD FRONT SHOULD BE ABOUT READY TO ENTER THE FORECAST AREA FROM
THE NW AT THE START OF THE PERIOD...WITH SUPPORT FROM AN APPROACHING
UPPER TROUGH...AND A RIBBON OF HIGHER DEW POINTS OFF THE GULF ALONG
THE FRONT BEING ADVECTED ALONG BY A 30-40 KT LOW LEVEL FLOW JUST OFF
THE SURFACE. ALL THIS CONSIDERED...THERE WILL LIKELY BE AN ONGOING
CONVECTIVE EVENT...WITH MODELS SHOWING THE GREATEST LIKELIHOOD OF
THIS IN THE SE PART OF THE AREA. AS THE FRONT SLOWLY PUSHES INTO AND
THROUGH THE FORECAST AREA SUNDAY AND SUNDAY EVENING...THERE COULD
ALSO BE ADDITIONAL DEVELOPMENT...WITH THE GREATEST OPPORTUNITY FOR
THIS IN THE SE WHERE FROPA WILL OCCUR LAST. THE LAST OF ANY
LINGERING PRECIP SHOULD END SUNDAY NIGHT OR EARLY MONDAY AS THE
FRONT CONTINUES ON TO OUR SE.
HIGH PRESSURE OVER THE MIDWEST WILL SUPPLY NOTICEABLY DRIER AND
SOMEWHAT COOLER AIR EARLY IN THE WEEK UNDER WNW FLOW ALOFT. RIDGING
ALOFT WILL PASS OVER ON TUESDAY INTO WEDNESDAY...WITH THE SURFACE
HIGH SHIFTING EASTWARD. THIS WILL BRING A CONTINUATION OF DRY
WEATHER...BUT WITH WARMING ALREADY OCCURRING AND AN EVENTUAL
INCREASE IN SURFACE MOISTURE.
AFTER THIS...MODEL DIFFERENCES BETWEEN THE GFS AND ECMWF BECOME MORE
APPARENT LATE IN THE WEEK. THE ECMWF DEVELOPS AN UPPER RIDGE OVER
THE CAROLINAS...BUT THIS FEATURE IS LACKING IN THE OPERATIONAL GFS.
ALL MODELS INDICATE AN UPPER LOW HEADING EAST ALONG THE CANADIAN
BORDER AND INTO ONTARIO...WITH A SOUTHWARD EXTENDING TROUGH. THE 00Z
ECMWF DOES NOT ALLOW AS MUCH OF A SOUTHERN EXTENSION OF THIS TROUGH
DUE TO ITS CAROLINA RIDGE. THE RESULT IS THAT THE GFS DEVELOPS
CONVECTION OVER THE LOCAL AREA FROM WEDNESDAY ON. MEANWHILE...THE
ECMWF SHOWS LIGHT PRECIP ONLY ON THURSDAY AS THE TROUGH SCOOTS BY TO
OUR NORTH. THE GEM AND GFS ENSEMBLE MEAN SUPPORT THE OPERATIONAL
GFS...AND PREFER TO WEIGHT THE FORECAST TOWARD IT...WITH JUST A BIT
OF ECMWF INFLUENCE TO KNOCK THE POPS DOWN SLIGHTLY FROM WHERE THEY
WOULD OTHERWISE BE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 121 PM EDT FRI MAY 31 2013
CONVECTION IS CURRENTLY DEVELOPING ACROSS CENTRAL KY AND EXPECT
SCATTERED SHOWERS AND THUNDERSTORMS TO MOVE INTO THE WESTERN PART OF
THE FORECAST AREA BY MID TO LATE AFTERNOON. CURRENT INDICATIONS ARE
THAT ANY CONVECTION THAT MOVES INTO OR DEVELOPS OVER EASTERN KY WILL
DECREASE QUICKLY EARLY THIS EVENING. THERE IS CONSIDERABLE
UNCERTAINTY HOW FAR EAST ANY SHOWERS OR THUNDERSTORMS WILL
OCCUR...AND AT THIS TIME WILL NOT MENTION ANY THUNDER IN THE JKL OR
LOZ TAF. WILL GO WITH VCTS IN THE SME TAF. OUTSIDE OF ANY SHOWER OR
THUNDERSTORMS VFR CONDITIONS WILL PREVAIL FOR THE REMAINDER OF THE
DAY. ALSO EXPECT VFR CONDITIONS TO PREVAIL TONIGHT AS WELL. THE
EXCEPTION TO THIS WOULD BE ANY AREAS THAT RECEIVE RAIN TODAY WHERE
OVERNIGHT FOG WOULD BE POSSIBLE. VFR WILL PREVAIL AGAIN SATURDAY
MORNING...WITH SHOWERS AND THUNDERSTORMS AGAIN POSSIBLE SATURDAY
AFTERNOON. AN APPROACHING COLD FRONT WILL BRING WIDESPREAD SHOWERS
AND THUNDERSTORMS SATURDAY NIGHT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SBH
LONG TERM...HAL
AVIATION...SBH
AREA FORECAST DISCUSSION
NWS JACKSON KY
121 PM EDT FRI MAY 31 2013
.UPDATE...
ISSUED AT 1236 PM EDT FRI MAY 31 2013
MESOSCALE CONVECTIVE VORTEX EVIDENT IN RADAR IMAGERY NEAR MADISONVILLE
KY MOVING NE. AHEAD OF THIS A BROKEN LINE OF CONVECTION IS
INCREASING FROM LOUISVILLE SOUTHWARD TO THE EAST OF GLASGOW KY AND
THEN SOUTH INTO TN. THIS IS ALONG AN OUTFLOW FROM THIS MORNINGS
CONVECTION. CURRENT INDICATIONS ARE ADDITIONAL OUTFLOW FROM THIS
CONVECTION WILL TRIGGER SCATTERED SHOWERS AND THUNDERSTORMS
OVER THE SOUTHWEST PART OF THE FORECAST AREA BY 20Z IF NOT A LITTLE
SOONER. WILL CONTINUE WITH FORECAST OF SCATTERED SHOWERS AND
THUNDERSTORMS IN THE WESTERN PART OF FORECAST AREA THIS AFTERNOON AND
ISOLATED SHOWERS AND THUNDERSTORMS IN THE EAST. NDFD AND ZFP UPDATED.
UPDATE ISSUED AT 1024 AM EDT FRI MAY 31 2013
RADAR...SATELLITE AND LIGHTNING OBSERVATIONS ALL INDICATE A
WEAKENING TREND WITH CONVECTION OVER WESTERN KY. OUTFLOW FROM THIS
MAY TRIGGER CONVECTION OVER CENTRAL KY THIS AFTERNOON WITH A
MODERATELY UNSTABLE AIR MASS IN PLACE. THIS CONVECTION COULD THEN MAKE
ITS WAY INTO THE FORECAST AREA BY MID TO LATE AFTERNOON. THIS IDEA IS
SUPPORTED BY THE 12Z HRRR WHICH BRINGS SHOWERS AND THUNDERSTORMS INTO
THE WESTERN PART OF THE FORECAST AREA AROUND 20Z. PRIOR TO THIS
CONVECTION MAY BE INHIBITED DUE TO MID LEVEL CAPPING WHICH WAS
EVIDENT ON THE 12Z ILN SOUNDING. IN FACT THE SMALL SHOWERS THAT
DEVELOPED NORTHWEST OF FLEMING COUNTY AROUND 13Z EXHIBITED A WEAKENING
TREND ALMOST IMMEDIATELY AS THEY MOVED NNE INTO OH. THE HRRR DID A
GOOD JOB DEPICTING THE DEVELOPMENT OF SCATTERED SHOWERS IN THIS AREA
WITH A QUICK DISSIPATION TO THE SHOWERS. HAVE SLOWED THE ONSET OF
THUNDERSTORMS CHANCES FOR THIS AFTERNOON...AND LOWERED PROBABILITIES
ABOUT 10 PERCENT. WITH THIS IN MIND HAVE ALSO RAISED MAXIMUM
TEMPERATURES PRIMARILY IN THE EAST WHERE NEARLY THE ENTIRE DAY SHOULD
BE RAIN FREE. HOWEVER AFTERNOON TEMPERATURES WILL BE VERY DEPENDENT
ON SUNSHINE...AND THE CLOUD COVER FORECAST IS CHALLENGING AS DEBRIS
CLOUD FROM THIS MORNINGS CONVECTION MOVES EAST. UPDATED NDFD AND ZFP.
UPDATE ISSUED AT 735 AM EDT FRI MAY 31 2013
UPDATED THE FORECAST TO FINE TUNE THE POPS AND SKY THROUGH THE
MORNING HOURS....GENERALLY SLOWING THEM DOWN A TAD. ALSO APPLIED THE
LATEST OBS AND TRENDS TO THE T...TD...AND SKY GRIDS. IN ADDITION...
GIVEN THE ANTICIPATION OF ORGANIZED CONVECTIVE CLUSTERS AND UPPER
SUPPORT IN THE FORM OF THE TROUGH ANGLING THIS WAY ON SATURDAY WILL
ADD A BEEFIER MENTION OF THUNDERSTORMS...POSSIBLY SEVERE...TO THE
HWO. UPDATES HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. AN HWO
UPDATE WILL FOLLOW.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 350 AM EDT FRI MAY 31 2013
07Z SFC ANALYSIS SHOWS A LARGE AREA OF LOW PRESSURE...LOCATED OVER
THE NORTHERN PLAINS...STARTING TO AFFECT WESTERN KENTUCKY WHILE THE
WESTERN EXTENT OF HIGH PRESSURE OVER THE CAROLINAS IS HOLDING ON
OVER THE EAST. THIS HAS KEPT THE SKIES MOSTLY CLEAR THROUGH THE
NIGHT...THUS FAR...AND...WHEN COMBINED WITH LIGHT WINDS...ANOTHER
DECENT NIGHT OF RADIATIONAL COOLING IN UNDERWAY. AS IS NORMAL FOR
THESE SITUATIONS...THE SHELTERED VALLEYS HAVE DECOUPLED AND ARE
RUNNING A GOOD 10 DEGREES OR SO BELOW THE MILDER RIDGES WITH SPECIFIC
TEMPERATURES VARYING FROM AROUND 60 IN THE DEEPER SPOTS TO AROUND 70
ON THE HILLS...IN THE THERMAL BELT. DEWPOINTS ARE ABOUT THE SAME AS
LAST NIGHT WITH READINGS GENERALLY IN THE LOWER 60S. AGAIN...EXPECT
SOME PATCHY FOG IN THE DEEPER VALLEYS...BUT PRIMARILY JUST NEAR THE
RIVERS AND OTHER BODIES OF WATER.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE SOUTHEAST RIDGING...
THAT HAS PROTECTED THE AREA FROM MOST OF THE CONVECTION THESE PAST
COUPLE OF DAYS...YIELDING TO THE DEVELOPING DEEP AND BROAD MID LEVEL
LOW OVER THE NORTHERN PLAINS. A COUPLE OF LEADING SHORTWAVES WILL
MOVE INTO THE OHIO VALLEY TODAY...BRUSHING BY TO THE NORTH OF OUR
CWA. FOLLOWING THIS...THE UPPER LOW WILL SLIP INTO THE UPPER MIDWEST
AND AS A RESULT DRIVE THE HEIGHTS DOWN THROUGHOUT KENTUCKY DURING
THE DAY SATURDAY. WITH THE MODELS SUCH AGREEMENT...HAVE BASICALLY
FOLLOWED A GENERAL BLEND AND KEYED IN ON THE HIGHER RESOLUTION NAM12
AND HRRR FOR DETAILS.
SENSIBLE WEATHER WILL FEATURE A CHANCE OF SHOWERS AND
THUNDERSTORMS...CURRENTLY AFFECTING WESTERN KENTUCKY...MOVING INTO
THE WESTERN PORTIONS OF EAST KENTUCKY LATER THIS MORNING AND THEN
DRIFTING EAST DURING THE REST OF THE DAY. THE EXTRA CLOUDS AND PCPN
AROUND SHOULD BE ENOUGH TO KEEP HIGH TEMPERATURES A BIT COOLER THAN
YESTERDAY. THE DAYTIME CONVECTION...FUELED BY SOME UPPER LEVEL
HELP...LOW LIS...MODERATE CAPE...AND ABOVE NORMAL PWS...WILL DIE OFF
BY EARLY EVENING LEAVING A MUGGY AIR MASS BEHIND FOR THE NIGHT WITH
ONLY A SMALL RIDGE TO VALLEY DIFFERENCE EXPECTED...BUT MORE IN THE
WAY OF PATCHY FOG. SATURDAY WILL SEE THE APPROACH OF THE SYSTEM/S
MAIN COLD FRONT AND THIS SHOULD BE ENOUGH TO KICK OFF ADDITIONAL AIR
MASS SHOWERS AND STORMS GIVEN A SIMILAR THERMAL AND MOISTURE PROFILE
AS FRIDAY.
AGAIN USED THE CONSSHORT FOR TD AND WINDS THROUGH THE FIRST 24 HOURS
AS A STARTING POINT...WITH HIGHS A BIT LOWER THAN THURSDAY FOR BOTH
TODAY AND SATURDAY...WHILE USING THE CONSALL FOR A STARTING POINT
TONIGHT. AS FOR POPS...GENERALLY ENDED UP CLOSER TO THE HIGHER MET
NUMBERS THROUGHOUT THE SHORT TERM PORTION OF THE FORECAST.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 300 AM EDT FRI MAY 31 2013
A MID/UPPER LEVEL TROUGH WILL SWING ACROSS KENTUCKY SATURDAY NIGHT
INTO SUNDAY NIGHT...PRODUCING A PERIOD OF SHOWERS AND THUNDERSTORMS
FOR THE AREA. MODELS ARE ALL IN PRETTY DECENT AGREEMENT SO HAVE
INCREASED POPS FROM LATE SATURDAY NIGHT INTO SUNDAY. SEVERE THREAT
IS FAIRLY MINIMAL AS CLOUD COVER MAY LIMIT INSTABILITY AND SHEAR IS
QUITE WEAK. FRONT WILL DEPART TO THE SOUTH SUNDAY NIGHT...WITH RAIN
CHANCES DROPPING SOUTHEASTWARD. A COOLER AND LESS HUMID AIRMASS WILL
SETTLE INTO THE AREA FOR THE EARLY PORTION OF NEXT WEEK...ALLOWING
FOR VERY PLEASANT CONDITIONS FOR EARLY JUNE. ANOTHER RIDGE OF HIGH
PRESSURE WILL BUILD OVER THE SOUTHEAST BY THE MIDDLE TO LATE
PORTIONS OF NEXT WEEK WITH RETURN FLOW AGAIN ESTABLISHING ITSELF
OVER THE AREA. AS MOISTURE INCREASES BY MIDWEEK...RAIN CHANCES WILL
SLOWLY RAMP UP SIMILAR TO THIS PAST WEEK. TEMPERATURES WILL TURN
MILDER AS WELL AS THE WEEK GOES ON. MODELS ARE ALL IN DECENT
AGREEMENT THROUGH THE END OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 121 PM EDT FRI MAY 31 2013
CONVECTION IS CURRENTLY DEVELOPING ACROSS CENTRAL KY AND EXPECT
SCATTERED SHOWERS AND THUNDERSTORMS TO MOVE INTO THE WESTERN PART OF
THE FORECAST AREA BY MID TO LATE AFTERNOON. CURRENT INDICATIONS ARE
THAT ANY CONVECTION THAT MOVES INTO OR DEVELOPS OVER EASTERN KY WILL
DECREASE QUICKLY EARLY THIS EVENING. THERE IS CONSIDERABLE
UNCERTAINTY HOW FAR EAST ANY SHOWERS OR THUNDERSTORMS WILL
OCCUR...AND AT THIS TIME WILL NOT MENTION ANY THUNDER IN THE JKL OR
LOZ TAF. WILL GO WITH VCTS IN THE SME TAF. OUTSIDE OF ANY SHOWER OR
THUNDERSTORMS VFR CONDITIONS WILL PREVAIL FOR THE REMAINDER OF THE
DAY. ALSO EXPECT VFR CONDITIONS TO PREVAIL TONIGHT AS WELL. THE
EXCEPTION TO THIS WOULD BE ANY AREAS THAT RECEIVE RAIN TODAY WHERE
OVERNIGHT FOG WOULD BE POSSIBLE. VFR WILL PREVAIL AGAIN SATURDAY
MORNING...WITH SHOWERS AND THUNDERSTORMS AGAIN POSSIBLE SATURDAY
AFTERNOON. AN APPROACHING COLD FRONT WILL BRING WIDESPREAD SHOWERS
AND THUNDERSTORMS SATURDAY NIGHT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SBH
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...SBH
AREA FORECAST DISCUSSION
NWS JACKSON KY
1237 PM EDT FRI MAY 31 2013
.UPDATE...
ISSUED AT 1236 PM EDT FRI MAY 31 2013
MESOSCALE CONVECTIVE VORTEX EVIDENT IN RADAR IMAGERY NEAR MADISONVILLE
KY MOVING NE. AHEAD OF THIS A BROKEN LINE OF CONVECTION IS
INCREASING FROM LOUISVILLE SOUTHWARD TO THE EAST OF GLASGOW KY AND
THEN SOUTH INTO TN. THIS IS ALONG AN OUTFLOW FROM THIS MORNINGS
CONVECTION. CURRENT INDICATIONS ARE ADDITIONAL OUTFLOW FROM THIS
CONVECTION WILL TRIGGER SCATTERED SHOWERS AND THUNDERSTORMS
OVER THE SOUTHWEST PART OF THE FORECAST AREA BY 20Z IF NOT A LITTLE
SOONER. WILL CONTINUE WITH FORECAST OF SCATTERED SHOWERS AND
THUNDERSTORMS IN THE WESTERN PART OF FORECAST AREA THIS AFTERNOON AND
ISOLATED SHOWERS AND THUNDERSTORMS IN THE EAST. NDFD AND ZFP UPDATED.
UPDATE ISSUED AT 1024 AM EDT FRI MAY 31 2013
RADAR...SATELLITE AND LIGHTNING OBSERVATIONS ALL INDICATE A
WEAKENING TREND WITH CONVECTION OVER WESTERN KY. OUTFLOW FROM THIS
MAY TRIGGER CONVECTION OVER CENTRAL KY THIS AFTERNOON WITH A
MODERATELY UNSTABLE AIR MASS IN PLACE. THIS CONVECTION COULD THEN MAKE
ITS WAY INTO THE FORECAST AREA BY MID TO LATE AFTERNOON. THIS IDEA IS
SUPPORTED BY THE 12Z HRRR WHICH BRINGS SHOWERS AND THUNDERSTORMS INTO
THE WESTERN PART OF THE FORECAST AREA AROUND 20Z. PRIOR TO THIS
CONVECTION MAY BE INHIBITED DUE TO MID LEVEL CAPPING WHICH WAS
EVIDENT ON THE 12Z ILN SOUNDING. IN FACT THE SMALL SHOWERS THAT
DEVELOPED NORTHWEST OF FLEMING COUNTY AROUND 13Z EXHIBITED A WEAKENING
TREND ALMOST IMMEDIATELY AS THEY MOVED NNE INTO OH. THE HRRR DID A
GOOD JOB DEPICTING THE DEVELOPMENT OF SCATTERED SHOWERS IN THIS AREA
WITH A QUICK DISSIPATION TO THE SHOWERS. HAVE SLOWED THE ONSET OF
THUNDERSTORMS CHANCES FOR THIS AFTERNOON...AND LOWERED PROBABILITIES
ABOUT 10 PERCENT. WITH THIS IN MIND HAVE ALSO RAISED MAXIMUM
TEMPERATURES PRIMARILY IN THE EAST WHERE NEARLY THE ENTIRE DAY SHOULD
BE RAIN FREE. HOWEVER AFTERNOON TEMPERATURES WILL BE VERY DEPENDENT
ON SUNSHINE...AND THE CLOUD COVER FORECAST IS CHALLENGING AS DEBRIS
CLOUD FROM THIS MORNINGS CONVECTION MOVES EAST. UPDATED NDFD AND ZFP.
UPDATE ISSUED AT 735 AM EDT FRI MAY 31 2013
UPDATED THE FORECAST TO FINE TUNE THE POPS AND SKY THROUGH THE
MORNING HOURS....GENERALLY SLOWING THEM DOWN A TAD. ALSO APPLIED THE
LATEST OBS AND TRENDS TO THE T...TD...AND SKY GRIDS. IN ADDITION...
GIVEN THE ANTICIPATION OF ORGANIZED CONVECTIVE CLUSTERS AND UPPER
SUPPORT IN THE FORM OF THE TROUGH ANGLING THIS WAY ON SATURDAY WILL
ADD A BEEFIER MENTION OF THUNDERSTORMS...POSSIBLY SEVERE...TO THE
HWO. UPDATES HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. AN HWO
UPDATE WILL FOLLOW.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 350 AM EDT FRI MAY 31 2013
07Z SFC ANALYSIS SHOWS A LARGE AREA OF LOW PRESSURE...LOCATED OVER
THE NORTHERN PLAINS...STARTING TO AFFECT WESTERN KENTUCKY WHILE THE
WESTERN EXTENT OF HIGH PRESSURE OVER THE CAROLINAS IS HOLDING ON
OVER THE EAST. THIS HAS KEPT THE SKIES MOSTLY CLEAR THROUGH THE
NIGHT...THUS FAR...AND...WHEN COMBINED WITH LIGHT WINDS...ANOTHER
DECENT NIGHT OF RADIATIONAL COOLING IN UNDERWAY. AS IS NORMAL FOR
THESE SITUATIONS...THE SHELTERED VALLEYS HAVE DECOUPLED AND ARE
RUNNING A GOOD 10 DEGREES OR SO BELOW THE MILDER RIDGES WITH SPECIFIC
TEMPERATURES VARYING FROM AROUND 60 IN THE DEEPER SPOTS TO AROUND 70
ON THE HILLS...IN THE THERMAL BELT. DEWPOINTS ARE ABOUT THE SAME AS
LAST NIGHT WITH READINGS GENERALLY IN THE LOWER 60S. AGAIN...EXPECT
SOME PATCHY FOG IN THE DEEPER VALLEYS...BUT PRIMARILY JUST NEAR THE
RIVERS AND OTHER BODIES OF WATER.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE SOUTHEAST RIDGING...
THAT HAS PROTECTED THE AREA FROM MOST OF THE CONVECTION THESE PAST
COUPLE OF DAYS...YIELDING TO THE DEVELOPING DEEP AND BROAD MID LEVEL
LOW OVER THE NORTHERN PLAINS. A COUPLE OF LEADING SHORTWAVES WILL
MOVE INTO THE OHIO VALLEY TODAY...BRUSHING BY TO THE NORTH OF OUR
CWA. FOLLOWING THIS...THE UPPER LOW WILL SLIP INTO THE UPPER MIDWEST
AND AS A RESULT DRIVE THE HEIGHTS DOWN THROUGHOUT KENTUCKY DURING
THE DAY SATURDAY. WITH THE MODELS SUCH AGREEMENT...HAVE BASICALLY
FOLLOWED A GENERAL BLEND AND KEYED IN ON THE HIGHER RESOLUTION NAM12
AND HRRR FOR DETAILS.
SENSIBLE WEATHER WILL FEATURE A CHANCE OF SHOWERS AND
THUNDERSTORMS...CURRENTLY AFFECTING WESTERN KENTUCKY...MOVING INTO
THE WESTERN PORTIONS OF EAST KENTUCKY LATER THIS MORNING AND THEN
DRIFTING EAST DURING THE REST OF THE DAY. THE EXTRA CLOUDS AND PCPN
AROUND SHOULD BE ENOUGH TO KEEP HIGH TEMPERATURES A BIT COOLER THAN
YESTERDAY. THE DAYTIME CONVECTION...FUELED BY SOME UPPER LEVEL
HELP...LOW LIS...MODERATE CAPE...AND ABOVE NORMAL PWS...WILL DIE OFF
BY EARLY EVENING LEAVING A MUGGY AIR MASS BEHIND FOR THE NIGHT WITH
ONLY A SMALL RIDGE TO VALLEY DIFFERENCE EXPECTED...BUT MORE IN THE
WAY OF PATCHY FOG. SATURDAY WILL SEE THE APPROACH OF THE SYSTEM/S
MAIN COLD FRONT AND THIS SHOULD BE ENOUGH TO KICK OFF ADDITIONAL AIR
MASS SHOWERS AND STORMS GIVEN A SIMILAR THERMAL AND MOISTURE PROFILE
AS FRIDAY.
AGAIN USED THE CONSSHORT FOR TD AND WINDS THROUGH THE FIRST 24 HOURS
AS A STARTING POINT...WITH HIGHS A BIT LOWER THAN THURSDAY FOR BOTH
TODAY AND SATURDAY...WHILE USING THE CONSALL FOR A STARTING POINT
TONIGHT. AS FOR POPS...GENERALLY ENDED UP CLOSER TO THE HIGHER MET
NUMBERS THROUGHOUT THE SHORT TERM PORTION OF THE FORECAST.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 300 AM EDT FRI MAY 31 2013
A MID/UPPER LEVEL TROUGH WILL SWING ACROSS KENTUCKY SATURDAY NIGHT
INTO SUNDAY NIGHT...PRODUCING A PERIOD OF SHOWERS AND THUNDERSTORMS
FOR THE AREA. MODELS ARE ALL IN PRETTY DECENT AGREEMENT SO HAVE
INCREASED POPS FROM LATE SATURDAY NIGHT INTO SUNDAY. SEVERE THREAT
IS FAIRLY MINIMAL AS CLOUD COVER MAY LIMIT INSTABILITY AND SHEAR IS
QUITE WEAK. FRONT WILL DEPART TO THE SOUTH SUNDAY NIGHT...WITH RAIN
CHANCES DROPPING SOUTHEASTWARD. A COOLER AND LESS HUMID AIRMASS WILL
SETTLE INTO THE AREA FOR THE EARLY PORTION OF NEXT WEEK...ALLOWING
FOR VERY PLEASANT CONDITIONS FOR EARLY JUNE. ANOTHER RIDGE OF HIGH
PRESSURE WILL BUILD OVER THE SOUTHEAST BY THE MIDDLE TO LATE
PORTIONS OF NEXT WEEK WITH RETURN FLOW AGAIN ESTABLISHING ITSELF
OVER THE AREA. AS MOISTURE INCREASES BY MIDWEEK...RAIN CHANCES WILL
SLOWLY RAMP UP SIMILAR TO THIS PAST WEEK. TEMPERATURES WILL TURN
MILDER AS WELL AS THE WEEK GOES ON. MODELS ARE ALL IN DECENT
AGREEMENT THROUGH THE END OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 745 AM EDT FRI MAY 31 2013
A COUPLE MID LEVEL SHORTWAVES WILL PASS JUST NORTH OF THE AREA TODAY.
THE FIRST OF THESE IS RESPONSIBLE FOR THE AREA OF CONVECTION OVER
WESTERN KENTUCKY. THIS AREA IS EXPECTED TO PUSH EAST INTO THE AREA
LATE THIS MORNING...BUT QUESTIONS REMAIN WHETHER IT WILL BE DECAYING
OR STEADY STATE WHEN IT ENTERS...AIDED BY THE BUILDING INSTABILITY
WROUGHT BY DIURNAL HEATING. SINCE THE EXACT TIMING AND LOCATION OF
THIS REMNANT OR HEALTHY CONVECTIVE CLUSTER COME MIDDAY IS STILL
UNCERTAIN HAVE GONE WITH VCTS. THIS FIRST SURGE OF CONVECTION WILL
DIE OUT BY EVENING AND FOLLOWING THAT EXPECT THE CIGS TO SCATTER OUT.
THE INPUT OF MORE MOISTURE IN THE ENVIRONMENT WILL INCREASE THE
POTENTIAL FOR PATCHY VALLEY FOG LATE TONIGHT. WINDS THROUGHOUT THE
PERIOD WILL BE AROUND 10 KTS...OR LESS...AND GENERALLY FROM THE
SOUTH.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SBH
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS CARIBOU ME
521 PM EDT FRI MAY 31 2013
.SYNOPSIS...
A COLD FRONT WILL DROP SOUTH INTO NORTHERN MAINE TONIGHT. THE
FRONT WILL LIFT BACK TO THE NORTH AS A WARM FRONT LATE SATURDAY
NIGHT. A STRONG COLD FRONT WILL APPROACH FROM THE WEST LATE IN THE
DAY SUNDAY AND VERY SLOWLY CROSS THE REGION SUNDAY NIGHT THROUGH
MONDAY NIGHT.
&&
.NEAR TERM /THROUGH SATURDAY/...
515 PM UPDATE: WE UPDATED POPS TO INCREASE TO CATEGORICAL RANGE
FOR NRN ME TO ACCOUNT FOR THE LN OF TSTMS MOVG IN FROM QB.
ENHANCED WORDING FOR DAMAGING WINDS...HAIL AND HEAVY DOWNPOURS
WERE INCLUDED TIL 11 PM...AT WHICH POINT...THE HRRR MODEL INDICATES
THAT MOST OF THE STRONG TSTM ELEMENTS WILL HAVE MOVED SE INTO NB.
ALSO UPDATED QPF FOR THE 18-24Z AND 00-06Z TM FRAMES TNGT TO
INCREASE TO CVR CONVECTIVE RNFL RATES WITH THIS LN. 1-3 HR FLASH
FLOOD GUIDANCE IS ONLY ABOUT 1.50 INCHES FOR MOST OF NRN ME...SO
WE WILL BE MONITORING FOR POSSIBLE LCLZD FLOODING AS WELL.
ORGNL DISC: A VERY WARM AND HUMID AIR MASS WILL REMAIN IN PLACE
THROUGH TONIGHT. A COLD FRONT WILL SAG SOUTHWARD OUT OF QUEBEC
INTO THE SAINT JOHN VALLEY THIS EVENING AND BRING THE THREAT OF
STRONG OR SEVERE THUNDERSTORMS WITH DAMAGING WINDS AND SMALL HAIL.
WITH STRONG WINDS ALOFT AND FAST STORM MOTIONS...SOME BOWING LINE
SEGMENTS ARE POSSIBLE AS THIS CONVECTION ENTERS THE NORTHERN END
OF THE CWA THIS EVENING. DOWNED TREES WERE ALREADY REPORTED WITH A
WEAKER THUNDERSTORM IN FORT KENT THIS AFTERNOON. DEEPER STORMS MAY
ALLOW FOR UP TO QUARTER SIZE HAIL BRIEFLY. WITH PWATS OVER ONE AND
HALF INCH...HEAVY DOWNPOURS ARE EXPECTED. THESE STORMS COULD REACH
40K FT. THE SEVERE WEATHER THREAT SHOULD BE RESTRICTED PRIMARILY
TO ZONES ONE AND TWO IN NORTHERN AROOSTOOK WITH STORMS WEAKENING
BY THE TIME THEY REACH HOULTON LATER THIS EVENING.
ELSEWHERE IN THE FORECAST AREA...AIR MASS THUNDERSTORMS WILL END
LATER THIS AFTERNOON AND A WARM AND HUMID NIGHT IS EXPECTED WITH
LOWS IN THE UPPER 60S FOR DOWN EAST AND AROUND BANGOR. LOWS WILL
BE IN THE LOW 60S TOWARDS THE CROWN OF MAINE. THE COLD FRONT WILL
STALL IN NORTHERN MAINE WITH CLOUD COVER AND THUNDERSTORMS
PERSISTING WELL INTO THE NIGHT.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
ACTIVE WEATHER IS EXPECTED DURING THE SHORT TERM WITH THE MAIN
CONCERNS THE POTENTIAL FOR STRONG TO SEVERE THUNDERSTORMS AND FLASH
FLOODING.
A FRONTAL BOUNDARY IS EXPECTED TO STRETCH ACROSS THE CENTRAL
PORTION OF THE CWA SAT EVENING. THE FRONT SHOULD LIFT BACK TO THE
NORTH AS A WARM FRONT SAT NIGHT AND SHOULD BE ACCOMPANIED BY
SHOWERS AND EMBEDDED THUNDERSTORMS...ESPECIALLY ACROSS THE
NORTHERN HALF OF THE AREA. PRECIPITABLE H20 IS PROGGED TO BE
AROUND 1.6-1.8 INCHES WHICH IS NEAR RECORD LEVELS FOR JUNE 1ST.
SHOWERS AND THUNDERSTORMS SAT NIGHT WILL HAVE THE POTENTIAL OF
PRODUCING HEAVY DOWNPOURS...AND DURING THE EVENING GUSTY WIND AND
SMALL HAIL. A STRONG COLD FRONT WILL APPROACH THE WESTERN BORDER
OF MAINE LATE IN THE DAY SUNDAY. THE MODELS DIFFER ON THE AMOUNT
OF INSTABILITY THAT WILL BE AVAILABLE SUN PM...AND MUCH WILL
DEPEND ON CLOUD COVER/PRE-EXISTING SHOWERS THAT COULD LIMIT JUST
HOW UNSTABLE IT BECOMES DURING THE AFTERNOON. THE MODELS DO
INDICATE ENOUGH CAPE AND SHEAR THAT SEVERE STORMS WILL BE POSSIBLE
DURING THE AFTERNOON/EVENING. THE HIGH PWATS ALSO MEAN THAT HEAVY
DOWNPOURS AND FLASH FLOODING WILL BE CONCERNS TOO...ESPECIALLY
GIVEN HOW SATURATED THE GROUND IS FROM THE RECENT HEAVY RAINS. THE
ENHANCED WORDING THAT THE MIDNIGHT CREW HAD IN LOOKS REAL GOOD AND
THE ONLY CHANGE WAS TO ADD THE LOCALLY HEAVY RAIN WORDING FOR SUN
PM/EVE. THE COLD FRONT IS EXPECTED TO ONLY VERY SLOWLY MOVE ACROSS
THE CWA SUN NIGHT AND MON AND MAY ONLY BE ON A HOULTON-BANGOR LINE
BY MON EVENING. THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS
MONDAY WILL LIKELY BE ACROSS THE SOUTHEAST OF THE CWA WITH SOME
DRYING TO BEGIN TO WORK INTO THE WESTERN ZONES. WILL AGAIN MENTION
HEAVY RAIN POSSIBLE ACROSS THE SOUTHEAST HALF OF THE CWA. WILL
HOLD OFF ON ANY ENHANCED SEVERE WEATHER LANGUAGE AS IT IS IN DAY
THREE. THE SPC DOES HAVE MUCH OF THE AREA IN A SLIGHT RISK FOR DAY
3.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE EXTENDED MODELS CONTINUE TO BE IN GOOD AGREEMENT THROUGH THE
EARLY AND MID PORTIONS OF THE EXTENDED. A LOW PRESSURE SYSTEM SE
OF JAMES BAY...WITH AN ASSOCIATED FRONTAL SYSTEM EXTENDING SOUTH
THROUGH DOWNEAST MAINE...THEN SOUTH ALONG THE ATLANTIC COAST. A
BERMUDA HIGH PRESSURE SYSTEM RIDGED INTO THE COAST...A SECOND HIGH
PRESSURE SYSTEM BUILDING SE OUT OF WRN CANADA. BY THE START OF THE
EXTENDED PERIOD THE NRN PORTIONS OF THE FRONT CONTINUES TO REMAIN
UNDER THE UPPER LEVEL RIDGE...THE SRN PORTION HOWEVER WILL BEGIN
TO MOVE OUT AS THE UPPER TROUGH MOVES TO THE EAST SIDE OF THE
APPALACHIANS. BOTH MODELS INDICATE A SECONDARY LOW DEVELOPING
ALONG COAST VA WHICH WILL ASSIST WITH THE EASTWARD MOVEMENT OF
THE FRONT. BY WED MRNG THE FRONT WILL BE WELL EAST OF THE
AREA...AND HIGHER PRESSURE WILL BUILD INTO MAINE. THE HIGH
PRESSURE RIDGE WILL REMAIN IN PLACE THROUGH AT LEAST FRI MRNG. FRI
MRNG A NEW LOW PRESSURE SYSTEM WILL BE CENTERED OVER THE GREAT
LAKES...WITH ITS SUPPORTING UPPER LOW OVER CENTRAL MANITOBA. THE
GFS SHOWS A WARM FRONT EXTENDED EAST INTO WRN MAINE. THE ECMWF FRI
MRNG MAINTAINS THE HIGH PRESSURE RIDGE WITH NO APPARENT WARM FRONT
ASSOCIATED WITH THE FRONT. BY FRI EVENING THE ECMWF SYSTEM BECOMES
A BIT MORE ORGANIZED WITH ITS UPPER LOW MOVING TO SW JAMES BAY.
BY SAT MRNG BOTH MODELS MOVE THE SHOWERS ASSOCIATED WITH THE LOW
INTO MAINE.
STARTED WITH A BASE OF GMOS...OVER LAID A BLEND OF OFFICIAL/ALL
MODEL BLEND FOR WNDS/POPS/SKY/MAX/MIN. ADDED 15 PERCENT TO WINDS
FOR GUSTS OVER LAND...25 PERCENT TO WINDS OVER COASTAL WATERS.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
NEAR TERM: VFR OUTSIDE OF THUNDERSTORMS LATE THIS AFTERNOON AND
EVENING. THUNDERSTORMS COULD BE SEVERE TOWARDS CAR...PQI AND FVE THIS
EVENING WITH DAMAGING WINDS AND SMALL HAIL. THE FRONT WILL STALL
AND COULD PRODUCE IFR VIS AND CIGS FROM PQI NORTHWARD INTO EARLY
SATURDAY MORNING. OTHERWISE...VFR CONDITIONS ARE EXPECTED.
SHORT TERM: VFR MUCH OF THE TIME SAT NIGHT THROUGH MONDAY...BUT A
PERIOD OF MVFR TO IFR POSSIBLE SAT NIGHT FROM KHUL NORTH IN SHOWERS
AND THUNDERSTORMS. ADDITIONAL PERIODS OF MVFR AND BRIEF IFR
POSSIBLE IN ANY NEAR CONVECTION SUN PM AND AGAIN MONDAY. STRONG AND
ERRATIC WIND GUSTS AND HAIL WILL BE POSSIBLE IN/NEAR THE STRONGEST
CONVECTION.
&&
.MARINE...
NEAR TERM: FOG IS EXPECTED TO RETURN LATER TONIGHT AND TOMORROW ON
THE WATERS. OTHERWISE...STABLE CONDITIONS MEAN LIGHT WINDS AND A
SOUTH SWELL AROUND 2 TO 3 FEET.
SHORT TERM: A SW WIND WILL PICK UP OUT AHEAD OF A COLD FRONT SUNDAY
AND MAY REACH SCA LEVELS BY SUN PM AND CONTINUE INTO MONDAY. THE
SEAS WILL LIKELY REACH SCA LEVELS BY SUNDAY AFTERNOON AND CONTINUE
INTO MONDAY WITH A SOUTH SWELL AND A COMBINED SEA/SWELL OF 8-10 FEET
EXPECTED BY SUNDAY NIGHT.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...VJN
SHORT TERM...CB
LONG TERM...NORTON
AVIATION...VJN/CB
MARINE...VJN/CB
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1233 PM EDT FRI MAY 31 2013
.SYNOPSIS...
A WARM RIDGE OF HIGH PRESSURE WILL BUILD REMAIN OVER MUCH OF THE
REGION INTO THE WEEKEND. A COLD FRONT WILL BRIEFLY SLIP SOUTHWARD
ACROSS NORTHERN AREAS LATER TONIGHT BEFORE PUSHING BACK TO THE
NORTHEAST AS A WARM FRONT LATE SATURDAY AND SATURDAY NIGHT. A STRONGER
COLD FRONT WILL CROSS THE REGION SUNDAY NIGHT THROUGH MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1215PM UPDATE...
ADDED DAMAGING WINDS ZONES ONE AND TWO THIS EVENING. BOWING LINE
SEGMENTS ARE POSSIBLE. LATEST RUC/HRRR GUIDANCE SHOWING 50 KTS AT
H850 COINCIDENT WITH STORMS. SMALL HAIL IS ALSO POSSIBLE BUT WINDS
SHOULD BE REGARDED AS THE PRIMARY THREAT.
PREVIOUSLY INCREASED HIGHS FOR TODAY AND ADJUSTED LOWS TONIGHT.
ALSO ADJUSTED TODAY`S CLOUD COVER BASED ON TRENDS AND LATEST
GUIDANCE.
9AM UPDATE...
HAVE ADDED ENHANCED WORDING FOR LOCALLY HEAVY RAINFALL AND GUSTY
WINDS THIS AFTERNOON AND EVENING...MOSTLY FOR NORTHERN AROOSTOOK
COUNTY. AS A FRONTAL BOUNDARY SAGS SOUTHWARD THIS EVENING TOWARDS
THE SAINT JOHN VALLEY...THE COMBINATION OF DAYTIME HEATING...DEW
POINTS IN THE 60S AND SIGNIFICANT INSTABILITY TO THE TROP WILL
PRODUCE HEAVY THUNDERSTORMS. 12Z RAOBS FROM CAR AND MANIWAKI AS
WELL AS BUFKIT FORECAST SOUNDINGS SHOW A DEEP DRY LAYER FROM THE
SFC TO H800. AS A RESULT...WINDS ARE ASSESSED AS THE MOST SIGNIFICANT
THREAT BESIDES HEAVY DOWNPOURS. PWATS ARE OVER AN INCH AND A HALF.
THE HRRR SEEMS TO HAVE A REASONABLE HANDLE ON THE SITUATION WITH
STRONGER CELLS ENTERING THE SAINT JOHN VALLEY THIS EVENING.
635 AM UPDATE...WHAT`S LEFT OF THE ISOLATED TSTM THAT ENTERED THE
WESTERN MAINE BORDER NEAR DAAQUAM EARLIER THIS MORNING HAS BEEN
MOVING STEADILY SOUTHEAST AND WILL BE NEAR HOULTON SHORTLY. NOT
MUCH LTNG WITH THIS CELL AT THE MOMENT BUT WILL CONTINUE TO
MENTION ISOLATED THUNDER THIS MORNING...BUT THE BEST CHANCE FOR
THUNDER WILL BE THIS AFTERNOON. JUST SOME MINOR TWEAKS OTHERWISE
NO SIGNIFICANT CHANGES.
UNSEASONABLY WARM WEATHER CAN BE EXPECTED TODAY AS TEMPERATURES ARE
EXPECTED TO SOAR INTO THE LOW TO MID 80S ACROSS MOST OF NORTHERN AND
DOWNEAST MAINE TODAY. A COLD FRONT WILL APPROACH NORTHERN MOST MAINE
THIS AFTERNOON. THIS BOUNDARY WILL BE THE FOCUS FOR SCATTERED SHOWER
AND TSTM DEVELOPMENT...MAINLY THIS AFTERNOON. SB CAPE VALUES ARE
FORECASTED TO RANGE FROM 500 TO 1000 J/KG WITH EVEN HIGHER CAPE
VALUES ACROSS PORTIONS OF INTERIOR DOWNEAST MAINE WHERE MORE IN THE
WAY OF SURFACE HEATING IS EXPECTED.
DESPITE THE HIGHER CAPE VALUES THE BEST CHANCE OF ANY ORGANIZED
THUNDERSTORM DEVELOPMENT WILL BE ACROSS FAR NORTHERN MAINE AND
ESPECIALLY THE SAINT JOHN VALLEY WHERE THE APPROACHING BOUNDARY
WILL PROVIDE A FOCUS FOR CONVECTIVE DEVELOPMENT. ALTHOUGH WE ARE
EXPECTING ANY THUNDERSTORMS TO REMAIN BELOW SEVERE LIMITS AT THIS
TIME. ACROSS CENTRAL AND DOWNEAST MAINE EXPECT ISOLATED
THUNDERSTORMS.
EXPECT THE FRONTAL BOUNDARY TO SAG INTO NORTHERN MAINE OVERNIGHT AND
THIS WILL RESULT IN A CONTINUED CHANCE FOR SHOWERS AND PERHAPS A FEW
THUNDERSTORMS CONTINUING INTO THIS EVENING. PATCHY FOG WILL ALSO BE
POSSIBLE. LOWS TONIGHT WILL GENERALLY BE IN THE 60S.
NOTE: THE MAINE DEPARTMENT OF ENVIRONMENTAL PROTECTION HAS ISSUED AN
AIR QUALITY ALERT FOR THE DOWNEAST COAST FOR UNHEALTHY FOR SENSITIVE
GROUPS DUE TO OZONE. THIS ALERT IS IN EFFECT FRO 11 AM UNTIL 11 PM
TONIGHT.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
NOT MUCH CHANGE FROM PREVIOUS THINKING AS MODELS REMAIN VRY
CONSISTENT W/ THEIR GUIDANCE THRU THIS PD... BACK DOOR COLD FRONT
STILL EXPECTED TO STALL FROM NW-SE MAINE SAT AM THEN LIFT NEWRD AS
A WARM FRONT LATE SAT THRU SAT NGT. WILL KEEP HIGHEST POPS (CHC TO
LOW LIKELY POPS) ACROSS THE CENTRAL AND N THRU SAT NGT FOR SHOWERS
AND OCNL THUNDER AS VRY WARM AND UNSTABLE AIR W AND SW OF THIS
FRONT OVERRUNS THIS BNDRY. THIS FRONT SHOULD ALSO CREATE A RATHER
DECENT NE-SW THERMAL GRADIENT ACROSS THE REGION W/ COOLEST TEMPS
FAR NERN AREAS WHERE CLD/SHOWERS AND BEING ON THE COOL SIDE OF THE
BNDRY SHOULD KEEP MAXES ON SAT IN THE LOWER-MID 70S WHILE OUR FAR
SWRN AREAS IN THE WARM AND HUMID AIRMASS COULD SEE TEMPS INTO THE
UPPER 80S OR EVEN TO 90 DEPENDING ON CLD CVR. BY LATE SAT NGT/ERLY
SUN AM...ALL AREAS BACK INTO THE WARM AND STICKY AIR W/ A STRONG
COLD FRONT THEN FCST TO APPROACH OUR FAR WRN/NWRN AREAS LATER SUN
AFTN. SFC-BASED CAPES OF 1500-2500 J/KG...MDT SHEAR AHEAD OF A
STRONG COLD FRONT SUGGESTS AN ELEVATED THREAT OF STRONG TO PSBLY
SEVERE STORMS SPCLY OUR WRN/NWRN AREAS FOR SUN AFTN. WILL CONT
ENHANCED WORDING AND CONTD MENTION IN THE HWO. FLASH FLOODING
RISKS REMAIN A CONCERN AS WELL W/ THE HVY RAINS AND SATURATED
SOIL FROM THIS PAST WEEKEND...
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE STRONG COLD FRONT ADDRESSED IN THE SHORT TERM SECTION ABV IS
FCST TO SLOWLY CROSS THE FA SUN NGT THRU MON AND EXIT OUR FAR
SERN AREAS BY ERLY TUE AM. THIS SLOW TRANSITION ACROSS THE FCST
AREA SUGGESTS AN ELEVATED THREAT FOR CONVECTION ACROSS OUR SERN
AREAS MON AFTN AND HAVE CARRIED LIKELY POPS FOR SHOWERS/TSTMS MON
AFTN OUR SERN ZNS... OTHERWISE...GRADUALLY COOLER AND DRIER AIR
IS FCST TO OVERSPREAD THE AREA THRU THE PD AS COOL CANADIAN HIGH
PRES BUILD INTO THE REGION. WILL KEEP MENTION OF SHOWERS ACROSS
THE N TUE AFTN AS A COLD UPPER TROF SWINGS EWRD ACROSS THE AREA...
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
NEAR TERM: VFR THIS MORNING WITH SOME LOCAL MVFR IN PATCHY FOG.
MAINLY VFR THIS AFTERNOON AND TONIGHT EXCEPT LCL MVFR IN SCATTERED
SHOWERS AND TSTMS.
SHORT TERM: MVFR TO PSBL IFR CONDS ACROSS THE NRN TAF SITES
SAT/SAT NGT IN SHOWERS/OCNL THUNDER ASSOCIATED W/ A FRONTAL BNDRY
WHICH WILL EVENTUALLY LIFT NE OF THE AREA BY LATER SAT NGT THEN
ANOTHER ROUND OF MVFR TO BRIEF IFR W/ SHOWERS/TSTMS LATER SUN AFTN
AS A STRONG COLD FRONT APPROACHES.
FOR THE SRN TAF SITES...EXPECT MAINLY VFR CONDS W/ SOME PSBL LATE
NGT/ERLY AM FOG SAT NGT. MVFR TO BRIEF IFR CONDS EXPECTED LATE SUN
INTO MON AS A STRONG COLD FRONT APPROACHES THEN CROSSES THESE AREAS...
&&
.MARINE...
NEAR TERM: WINDS/SEAS WILL REMAIN BELOW SCA LEVELS THROUGH TONIGHT.
SHORT TERM: WARM RIDGE OF HIGH PRES ACROSS THE WATERS THRU THE PD
WILL KEEP RATHER STABLE CONDS IN PLACE INTO SUN. BY LATER
SUN...DESPITE THIS STABILITY...A STRONG APPROACHING COLD FRONT MAY
ALLOW WND GUSTS TO REACH MARGINAL SCA LEVELS. SEAS MAY ALSO
INCREASE TO MARGINAL SCA LEVELS IN PERSISTENT SW FLOW IN ADVANCE
OF THIS APPROACHING FRONT BY LATER SUN...
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DUDA/MCW
SHORT TERM...KHW
LONG TERM...KHW
AVIATION...DUDA/MCW/KHW
MARINE...DUDA/MCW/KHW
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
214 PM EDT FRI MAY 31 2013
.SYNOPSIS...
HIGH PRESSURE REMAINS ANCHORED OFF THE MID ATLANTIC COAST THROUGH
SUNDAY. A COLD FRONT WILL BRING INCREASING RAIN CHANCES...AS IT
SLOWLY CROSSES THE AREA ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
VERY SIMILAR DAY WXWISE TO THU ON THE WAY FOR TODAY. EXPECTING
ANOTHER VERY WARM DAY, AS THE SFC RIDGE AND STRENGTHENING H5 RIDGE
ALOFT REMAINS QUASI- STATIONARY WELL OFFSHORE.
DRY WEATHER CONTINUES TODAY WITH PERSISTENT WARM/STABLE AIR ALOFT
AND A LACK OF AVAILABLE TRIGGERS FOR LIFT. HIGH-RES MODELS
(SPECIFICALLY THE HRRR AND SPC WRF) AGAIN PICKING UP THE THE
POTENTIAL FOR AN ISOLATED SHOWER OR TWO BLOWING UP ON AFTN
SEABREEZE OVER THE FAR SOUTHEAST PART OF THE CWA (AND ALSO ALONG
THE MASON-DIXON IN ASSN WITH A WEAK, SHEARED OUT SHORTWAVE
CROSSING WELL NORTH OF THE AKQ CWA). AS WITH YESTERDAY THOUGH,
RAIN CHC ACROSS LOCAL AREA REMAINS TOO SMALL TO INCLUDE POPS IN
THE FORECAST. THUS, HV CONTINUED TO CAP RAIN CHANCES AT 10% OR
LESS. HIGH TEMPERATURES AWAY FROM THE IMMEDIATE COAST AGAIN
GENERALLY ~90/L90S INLAND, LOW TO MID 80S AT IMMEDIATE COASTAL
AREAS.
CLEAR AND MILD OVERNIGHT...EARLY MORNING LOWS SAT MORNING IN THE
U60S TO NR 70.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
GRADUALLY WEAKENING H5 RIDGE OFF THE MID ATLANTIC COAST SHIFTS
SLIGHTLY TO THE EAST SATURDAY AND SUNDAY AHEAD OF APPROACHING
MID-LVL TROUGH, WHICH PUSHES FROM THE NORTHERN PLAINS TOWARDS THE
UPR GRT LAKES ON SUNDAY. HOWEVER, SFC/UPR LEVEL RIDGING OFFSHORE
WL REMAIN THE DOMINATE WX FEATURE THRU THE WEEKEND, BRINGING
CONTINUED SUMMER-LIKE CONDITIONS. LTL (IF ANY) TRIGGER EXISTS FOR
CONVECTION ON SAT, AS AIRMASS REMAINS LARGELY CAPPED. FCST
REMAINS DRY AS BEST CHCS FOR ANY CONVECTION WILL AGAIN BE CONFINED
OVER THE MTNS. HIGHS SAT IN THE U80S-L90S, THOUGH AGAIN COOLER AT
THE BEACHES DUE TO LCL AFTN SEA BREEZE EFFECTS.
PARTLY TO MOSTLY CLEAR SKY FOR MOST OF SAT NIGHT, THOUGH WL NEED
TO WATCH GFS, AS IT CONTINUES TO KEY IN ON POTENTIAL FOR SOME LOW
STRATUS OVER THE I-85 CORRIDOR BACK INTO THE CENTRAL NC PIEDMONT
LATE. ERY MORNING LOWS SUNDAY MORNING IN THE M-U60S.
AFTER ANY LINGERING STRATUS QUICKLY LIFTS/ERODES SUNDAY MORNING,
THE DAY STARTS OUT MAINLY SUNNY. HOWEVER, CLOUDS LOOK TO INCREASE
FROM THE WEST BY SUN AFTN AHEAD OF APPROACHING FRONTAL BOUNDARY.
SLIGHT CHC TO LOW CHC POPS STILL LOOK GOOD BY MID AFTN SUNDAY AS
TSRAS LOOK TO FIRE ALONG PRE-FRONTAL/LEE TROUGHING TO THE WEST AND
PUSH E-NE ACROSS OUR WESTERN TIER OF COUNTIES (WEST OF RIC) LATE
SUN AFTN. MORE IN THE WAY OF CLOUD COVER WILL BE BALANCED OUT BY
STRONG COMPRESSIONAL HEATING AHEAD OF THE FRONT, AGAIN YIELDING
HIGHS IN THE U80S TO NR 90. GIVEN DP TEMPS IN THE L-M60S (HIGHEST
JUST BEFORE DIURNAL MIXING KICKS IN JUST AFTER 12Z)...HEAT INDEX
VALUES XPCTD TO REMAIN WITHIN A DEGREE OR TWO OF ACTUAL TEMPS BOTH
DAYS.
ECMWF/GFS IN PRETTY GOOD AGREEMENT REGARDING FROPA/PCPN TIMING FOR
SUNDAY NIGHT AND MONDAY. FRONT SLOWLY APPROACHES, AND BEGINS TO
PUSH ACROSS THE WESTERN THIRD OF THE LOCAL AREA LATE SUNDAY
NIGHT/MONDAY MORNING. DUE TO THE LATE NIGHT/ERY MORNING TIMING,
INSTABILITY ATTM LOOKS TO BE MARGINAL AT BEST, SO WILL GO WITH ISO
T WORDING FOR NOW. STILL, AS PW VALUES SHOOT UPWARDS OF 1.75"
AREA-WIDE SUNDAY NIGHT, RAIN CHANCES ARE LOOKING INCREASINGLY
FAVORABLE ACROSS THE PIEDMONT AFTER 00Z MON/8PM SUNDAY NIGHT.
THUS, WL GO WITH LKLY POP WEST OF I-95 LT SUNDAY NIGHT, WITH CHCS
INCREASING FARTHER EAST AFTER MIDNIGHT THRU DAWN MONDAY MORNING.
GIVEN THE CONSIDERABLE CLDS/PCPN, WL GO CLOSER TO EURO STATISTICAL
GUIDANCE, WHICH IS ABT A CATEGORY ABOVE 00Z/31 MEX NUMBERS. ERY
MORNING LOWS MON MORNING RIGHT AROUND 70/LOW 70S.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
LONG TERM PERIOD BEGINS W/ THE FRONT SLOWLY MOVING ACRS THE AREA
MON, WITH SHRAS/TSTMS EXPECTED ACROSS THE AREA. ALTHO WAA IS
WEAK...DEEP LAYER MOISTURE...MID-LVL S/W ENERGY AND UPR-LVL
DIVERGENCE CONTINUE TO WARRANT LIKELY POPS...CONTINUING INTO SE
AREAS MON NGT. GIVEN THE RAIN AND CLDS...TEMPS MON WILL MAX OUT IN
THE UPR 70S TO MID 80S. THE RAIN WILL END FROM W TO E EARLY TUE AS
THE FRONT SLIDES OFFSHORE. SFC HI PRES THEN BLDS IN FROM THE
NW...WITH HIGHS ONLY IN THE UPR 70S TO LO 80S ON TUE AND WED.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
HIGH PRESSURE OFF THE COAST CONTINUES TO BRING A STRONG FETCH OF S-SW
WINDS TO THE REGION. SATELLITE SHOWS A LARGE FIELD OF FAIR WX CU
FROM FL TO VA WITH THE FLOW AROUND THE HIGH. WINDS MIGHT BE A
LITTLE GUSTY DURING THE AFTN AND EARLY EVENING 15-20 KT...BUT
SHOULD DIMINISH AFTER SUNSET. NO SIGNIFICANT WX EXPECTED OVER THE
NEXT 24-36 HOURS BUT THE AMOUNT OF LOW LEVEL MOISTURE MAY DEVELOP
INTO SOME STRATUS CIGS DURING THE OVERNIGHT...SO OPTED TO SHOW
CIGS OF 010-035 FT OVER TAF SITES AND SOME MVFR VIS WITH PTCHY
FOG. ONLY LOW TO MODERATE CONFIDENCE THAT THE CIGS OR VIS WILL BE
WIDESPREAD.
OUTLOOK...THERE WILL BE A BETTER CHANCE FOR MVFR/IFR FOG OR
STRATUS SUNDAY MORNING. ISOLATED THUNDERSTORMS WILL BE PSBL SUNDAY
EVENING. THE CHANCES INCREASE MONDAY AHEAD OF AN APPROACHING COLD
FRONT. DRY/VFR CONDITIONS RETURN BY TUESDAY.
&&
.MARINE...
WINDS WILL CONTINUE TO BE GENERALLY FROM THE SOUTH THROUGH THE
WEEKEND. WIND SPEEDS AT ELEVATED SITES ARE RUNNING SEVERAL KNOTS
HIGHER THAN THOSE NEAR THE SURFACE OF THE WATER DUE TO POOR MIXING
WITH THE COLD WATER. THIS SHOULD CONTINUE TO BE THE CASE THROUGH THE
WEEKEND.
CONDITIONS SHOULD REMAIN BELOW SCA CRITERIA THROUGH THE DAY
SATURDAY. SOUTHERLY WINDS MAY GAIN ENOUGH SOUTHERLY FETCH TO PRODUCE
MARGINAL 5 FOOT SEAS OVER THE NORTHERN COASTAL WATERS BY SATURDAY
NIGHT. HOWEVER...THE MAIN SCA EVENT SHOULD BEGIN SUNDAY NIGHT OVER
THE COASTAL WATERS NORTH OF CAPE CHARLES. ELSEWHERE...CONDITIONS
SHOULD BE JUST SHORT OF SCA AS A COLD FRONT APPROACHES THE REGION.
THE FRONT MOVES SLOWLY TO THE EAST MONDAY NIGHT AND TUESDAY. PRESENT
INDICATIONS ARE THAT THE POST FRONTAL ENVIRONMENT WILL FAIL TO
PRODUCE SCA BUT THIS MAY CHANGE.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...AIR QUALITY ALERT UNTIL MIDNIGHT EDT TONIGHT FOR MDZ021>024.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...MPR/MAM
LONG TERM...MAS
AVIATION...JEF
MARINE...LSA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1221 PM CDT FRI MAY 31 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 330 AM CDT FRI MAY 31 2013
EARLY MORNING WATER VAPOR IMAGERY TOGETHER WITH THE PRESSURE OF THE
1.5PVU SURFACE SHOWED A NARROW RIBBON OF POTENTIAL VORTICITY
PROTRUDING DOWN TO THE 450/500MB LEVEL. THIS PV RESERVOIR
ORIGINATED UPSTREAM OFF THE BRITISH COLUMBIA COAST...EXTENDED
SOUTHEAST ACROSS THE KS/NE BORDER...AND CURLED UP OVER THE UPPER
MIDWEST. OVERLAYING THE 300MB WINDS SHOWED AN AREA OF POSITIVE
VORTICITY OWING TO THE EASTERLY WINDS OF 30KTS ON THE POLEWARD SIDE
OF +100KT WESTERLY JET. AT THE SURFACE A 991 LOW WAS LOCATED BENEATH
THE LEADING EDGE OF THE PV GRADIENT ALONG THE SD/ND BORDER...WITH A
SURFACE COLD FRONT DRAPED ON THE EASTERN SIDE OF THE MISSOURI
RIVER VALLEY.
FOR TODAY THE 00Z RUN OF THE HOPWRF AND FEW RUNS OF
THE HRRR SHOWS ANOTHER ACTIVE DAY SOUTH AND EAST OF THE CWA WITH
SEVERAL THUNDERSTORM COMPLEXES EXPECTED TO DEVELOP AS THE DEEP SHEAR
ASSOCIATED WITH THE AFOREMENTIONED UPPER LEVEL JET MOVE ACROSS THE
MISSISSIPPI RIVER VALLEY. MEANWHILE IT SHOULD BE MAINLY DRY FOR THE
FIRST HALF OF FRIDAY ACROSS THE CWA. IN FACT FORECAST SOUNDINGS VIA
THE RAP SUPPORT MOSTLY SUNNY SKIES DURING THE MORNING HOURS.
HOWEVER...WITH THE VORT MAX ROTATING OVERHEAD EXPECT INCREASING
CLOUDS WITH SHOWERS/THUNDERSTORMS AS THE ATMOSPHERE DESTABILIZES BY
MID AFTERNOON...MORE SO THAN THE HIRES MODELS WOULD INDICATE. THE
BEST DEEP LAYER SHEAR WILL BE ACROSS EASTERN IOWA AND WISCONSIN...SO
SEVERE THREAT IS LOW IN MINNESOTA...BUT COULD SEE SOME STRONGER
STORMS IN WEST CENTRAL WISCONSIN. BUFR FORECAST SOUNDINGS SHOW
ROUGHLY 1000J/KG OF MLCAPE AND FREEZING LEVELS AROUND 9-10KFT
AGL...SO WOULD NOT BE SURPRISED TO GET SOME SMALL HAIL AND GUSTY
WINDS WITH A FEW OF THE STRONGER CELLS. THE BEST CHANCE FOR DEEPER
CONVECTION WILL BE IN EASTERN MN AND WESTERN WI. ON FRIDAY NIGHT
THE INSTABILITY WILL DECREASE GIVING WAY TO LIGHT WINDS AND LOW
STRATUS AS THE OCCLUDED CYCLONE SLOWLY WOBBLES EASTWARD. A FEW
LIGHT RAIN SHOWERS DEVELOP ACROSS THE WESTERN HALF OF THE CWA AS
INDICATED BY THE LOW LEVEL SATURATION SHOWN IN THE BUFR SOUNDINGS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 330 AM CDT FRI MAY 31 2013
CLOSED UPPER CIRCULATION OVER THE REGION SATURDAY. IT SHOULD
PROVIDE GENERAL CLOUDINESS AND THE THREAT OF SHOWERS MUCH OF THE
DAY. AS THE CIRCULATION PIVOTS EAST NORTHEAST AND WEAKENS...MODELS
SUGGEST SOME WEAK SURFACE BASED CAPE AND SOME SLIGHTLY NEGATIVE
BEST LI`S OVER EASTERN AREAS...INTO THE AFTERNOON. WILL NEED SOME
BREAKS IN THE CLOUDS TO GENERATE ANY SIGNIFICANT DESTABILIZATION.
OPTED TO MENTION ISOLATED THUNDER OVER THE EAST PORTION OF THE
CWA...MAINLY IN THE AFTERNOON. WITH SIGNIFICANT CLOUD COVER
AROUND...TEMPERATURES MAY NOT GET OUT OF THE 50S OVER THE WEST AND
WILL REMAIN IN THE 60S EAST.
THIS INITIAL SYSTEM MOVES EAST...AND BECOMES MORE PROGRESSIVE AS
THE NEXT SIGNIFICANT TROUGH MOVES ASHORE OVER THE PACIFIC
NORTHWEST LATER SUNDAY. THIS SHOULD PROVIDE A CLEARING
TREND...ALONG WITH DRIER CONDITIONS SUNDAY INTO MONDAY. SOME
RETURN FLOW...WARM AIR ADVECTION PATTERN DEVELOPS DURING THE DAY
MONDAY...MAINLY OVER THE FAR WEST. THE WESTERN CLOSED CIRCULATION
MOVES SLOWLY EAST OVER THE REGION...AND APPEARS TO AFFECT THE AREA
FOR THE REMAINDER OF THE WEEK. THIS WILL AGAIN PROVIDE A LONG
PERIOD OF CLOUDINESS AND THE THREAT OF SHOWERS AND THUNDERSTORMS
TO THE CWA. TUESDAY AND WEDNESDAY LOOK TO BE THE WETTEST DAYS...BUT
THE SHOWERY WEATHER PATTERN WILL CONTINUE THROUGH THURSDAY. THE
BELOW NORMAL TEMPERATURE PATTERN WILL ALSO CONTINUE INTO THE
FIRST PART OF JUNE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1205 PM CDT FRI MAY 31 2013
SHRA HAVE ALREADY DEVELOPED IN SE MN AHEAD OF A STRONG SHRTWV
ACROSS WESTERN IOWA. BEST INSTABILITY AND SHEAR WILL REMAIN EAST
OF THE FA...BUT RNH/MSP/EAU DO HAVE THE POTENTIAL OF GETTING
STRONGER STORMS AS EARLY AS 1-2 PM. EAU HAS THE BEST POTENTIAL OF
SVR WIND GUSTS AND LARGE HAIL BEFORE 1Z/01. ACROSS WESTERN MN...THE
UPPER LOW HAS NEARLY STALLED. BUT THIS LOW IS EXPECT TO SLOWLY
FILL AND MOVE TO THE E-NE OVER THE NEXT DAY OR SO. IFR/MVFR CIGS
WITH SCATTERED SHRA WILL OCCUR NEAR AND UNDER THIS LOW PRESSURE
SYSTEM...WITH THE BEST POTENTIAL OF -SHRA OCCURRING DURING THE
TYPICAL MID AFTN...TO LATE EVENING HRS AS INSTABILITY WILL BE THE
GREATEST. MVFR CIGS THIS AFTN WILL LIKELY RISE TO LOW END VFR IN
WESTERN MN...BUT LOWER ONCE AGAIN DURING THE EVENING AS THE LOW
TRACKS E-NE ACROSS THE NORTHERN FA. TIMING OF THE INITIAL TSRA
DEVELOPMENT ACROSS FAR EASTERN MN/WC WI WILL BE DEPENDENT ON WHEN
THE WEAKENING CAP BREAKS. AS PREVIOUSLY STATED...TSRA COULD
DEVELOP AS EARLY AS 1-2 PM BASED ON THE LATEST MESOSCALE MODEL
RUNS. SFC WINDS WILL BE STRONGEST THRU 21Z...THEN DECREASE AND
BECOMING LIGHT AND VARIABLE OVERNIGHT. ONCE THE LOW MOVES TO THE
EAST...WINDS WILL SHIFT TO THE SW/W...AND EVENTUALLY NW AND
INCREASE IN SPD.
KMSP...
BEST TIME FRAME FOR TSRA/SHRA WILL OCCUR BETWEEN 19-22Z...WITH
ONLY SHRA AFT 22Z. ANY TSRA THAT DUE DEVELOP HAVE THE CAPABILITY
OF PRODUCING VERY GUSTY WINDS UP TO 40 KTS...AND SMALL HAIL. WILL
MONITOR THE POTENTIAL OF AN AWW IF NEEDED. THIS EVENING WILL BE
VFR WITH WINDS DECREASE AND SHIFTING TO THE SW UNDER 6 KTS. BY
12-15Z...WINDS WILL SHIFT TO THE W...AND NW AND INCREASE DURING
THE AFTN. -SHRA WILL BE POSSIBLE ANY TIME AFT 15Z/01 AS THE SFC
LOW MOVES NORTH OF THE AIRPORT TERMINAL. VFR CIGS WILL LIKELY FALL
TO MVFR AS THE LOW MOVES CLOSER TO THE AIRPORT SITE OVERNIGHT.
/OUTLOOK FOR KMSP/
SAT EVENING...MVFR WITH -SHRA. WINDS NW AT 10G20KTS.
SUN...VFR. WINDS NNW AT 10KTS.
MON...VFR WITH -SHRA POSSIBLE LATE. WINDS ESE AT 10KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JRB
LONG TERM...DWE
AVIATION...JLT
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
600 PM CDT FRI MAY 31 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 1233 PM CDT FRI MAY 31 2013
SEE MESO AFD FOR MORE DETAILS THROUGH TONIGHT. MAIN CONCERN LATE
TONIGHT WILL BE FLOODING/HYDRO ISSUES. A STRENGTHENING LOW LEVEL
JET WILL IMPINGE ON APPROACHING MESOSCALE SFC BOUNDARY. PROGGED
PWATS AROUND 1.75 INCHES WITH CONTINUED LOW LEVEL MOISTURE
ADVECTION WITH THE POTENTIAL FOR A FORWARD PROPAGATING MCS WITH
HEAVY RAINFALL DEVELOPING ON THE OUTFLOW DOMINATE PORTION OF THE
MCS SOMEWHERE OVER THE REGION WHERE STORMS CAN TRAIN ALONG A WSW-
ENE ORIENTED OUTFLOW BOUNDARY. FCST GUIDANCE HAS TARGETED THE MO
OZARK PLATEAU FOR THIS SCENARIO WITH AN EXCESS OF 3-4 INCHES OF
RAIN...BUT CONFIDENCE ON THE PRECISE LOCATION OF THE EXCESSIVE/HEAVY
RAIN WILL BE AN UNFOLDING STORM AND MESOSCALE ISSUE.
THE COLD FRONT WILL FINALLY MOVE THROUGH THE REGION SATURDAY. MAY
HAVE TO WATCH FOR SOME REDEVELOPMENT ALONG THE FRONT AS IT
EXITS...BUT WILL TACKLE THAT LATER ON.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 1233 PM CDT FRI MAY 31 2013
SUNDAY AND MONDAY WILL BE QUIET AND COOL WITH HIGH PRESSURE NOSING
SOUTH INTO THE AREA. ANOTHER UPPER LOW WILL MOVE INTO THE UPPER
PLAINS WITH EMBEDDED SHORTWAVES IN THE W-E UPPER LEVEL FLOW TOWARD
THE MID/LATE WEEK PERIOD WITH INCREASING RAIN CHANCES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1233 PM CDT FRI MAY 31 2013
CONVECTION CURRENTLY TO THE NORTH OF THE TAF SITES AT 23Z. WILL
GRADUALLY SEE THIS TRANSITION SOUTHEASTWARD TONIGHT...BUT
TRANSITION WILL BE A SLOW ONE. HRRR SEEMS TO HANDLE THIS THIS BEST
AND HAVE USED AS GUIDANCE ON TAKING PRECIPITATION SOUTH THROUGH
THE AREA TONIGHT. EXPECTING VFR CONDITIONS OUTSIDE OF CONVECTION
AND MVFR CONDITIONS WITHIN THE CONVECTION. COLD FRONT SHOULD PUSH
THROUGH THE AREA ON SATURDAY FROM NORTH TO SOUTH.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR MOZ055>058-
066>071-077>083-088>098-101>106.
KS...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR KSZ073-097-101.
&&
$$
SHORT TERM...DSA
LONG TERM...DSA
AVIATION...DSA
AREA FORECAST DISCUSSION
NWS HASTINGS NE
322 PM CDT FRI MAY 31 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 319 PM CDT FRI MAY 31 2013
IN THE SYNOPTIC SCALE...THE LARGE UPPER LEVEL LOW PRESSURE SYSTEM
THAT HAS AFFECTED OUR WEATHER THE PAST FEW DAYS...CONTINUES TO SPIN
ACROSS THE DAKOTAS...WHILE RIDGING CONTINUES JUST OFF BOTH THE
WESTERN AND EASTERN COASTS. IN THE MID LEVELS...THIS SYSTEM
CONTINUES TO SURGE AN ABUNDANCE OF GULF COAST MOISTURE UP THE
MISSISSIPPI RIVER VALLEY INTO THE MIDWEST...AS SEEN IN RECENT
FLOODING ASSOCIATED WITH THUNDERSTORMS ACROSS THE COUNTRY`S
MIDSECTION. AT THE SURFACE...THE SYSTEM REMAINS NEARLY VERTICALLY
STACKED WITH LOW PRESSURE ALSO ALIGNED OVER THE DAKOTAS...AND A
SECONDARY LOW SITUATED SOUTH OF THE TROUGH AXIS ACROSS SOUTHEASTERN
KANSAS.
AS THE LOW PRESSURE SYSTEM CONTINUES TO SPIN...ALMOST NEARLY
STATIONARY...THE MAIN COLD FRONTAL BOUNDARY HAS ALREADY SHIFTED
THROUGH THE OUTLOOK AREA. HOWEVER...IT APPEARS A SECONDARY WEAK
TROUGH AXIS WILL ALSO SHIFT THROUGH THE AREA OVERNIGHT TONIGHT. WITH
THIS BOUNDARY...CONCERNS IN THE SHORT TERM WILL FOCUS MAINLY ON
PRECIPITATION CHANCES AND COOLER HIGH TEMPERATURES TOMORROW.
STARTING OFF THIS AFTERNOON...WATER VAPOR IMAGERY INDICATES THE
PRESENCE OF A WEAK SHORT WAVE TROUGH SLIDING THROUGH EASTERN
COLORADO SOUTH OF THE UPPER LEVEL LOW. AN AREA OF CUMULUS HAVE
DEVELOPED ACROSS THE AREA...AND BEGUN TO SPREAD NORTHEAST AS SEEN ON
VISIBLE SATELLITE. RADAR ALSO INDICATES AT LEAST SOME VERY LIGHT
RETURNS ACROSS NORTHWEST AND NORTH CENTRAL KANSAS. WENT AHEAD AND
PUT IN SLIGHT CHANCE POPS ACROSS NORTH CENTRAL KANSAS THROUGH THE
AFTERNOON...AS BOTH THE HRRR AND NAM MODEL SEEM TO BE HANDLING THIS
WELL. NOT EXPECTING MUCH MORE THAN A COUPLE SPRINKLES AND MAYBE A
RUMBLE OF THUNDER.
HEADING INTO THE OVERNIGHT HOURS...LATEST SATELLITE IMAGERY SHOWS
THE DEVELOPMENT OF A CUMULUS FIELD ACROSS MUCH OF NORTHWESTERN
NEBRASKA JUST BEHIND THE SECONDARY TROUGH AXIS. EXPECT THIS TROUGH
AXIS TO SLIDE THROUGH THE OUTLOOK AREA ROUGHLY AROUND 6Z...WITH WEST
WINDS SHIFTING TO THE NORTHWEST. CONTINUED SLIGHT POPS FOR THE
NORTHERN HALF OF THE OUTLOOK AREA OVERNIGHT...AS BOTH THE NAM AND
HRRR INDICATE AT LEAST SOME LIGHT SHOWERS TO PUSH THROUGH. THE UPPER
LEVEL LOW WILL FINALLY BEGIN TO SHIFT EASTWARD BY SATURDAY...THUS
DECREASING POPS FROM SOUTHWEST TO NORTHEAST THROUGHOUT THE DAY.
INSTABILITY THROUGHOUT MUCH OF THE SHORT TERM PERIOD...REMAINS
FAIRLY MINIMAL...WITH ONLY ABOUT 100 J/KG OR SO AT MOST. CONTINUED
WITH MENTION OF ONLY LIGHT RAIN SHOWERS AS A RESULT...AND LEFT OUT
MENTION OF THUNDER.
REGARDING TEMPERATURES ON SATURDAY...BEHIND THIS SECONDARY TROUGH
AXIS...COOLER AIR...WITH 850 MB TEMPERATURES ON THE ORDER OF 3 TO 4
DEGREES CELSIUS WILL SLIDE SOUTH INTO THE OUTLOOK AREA.
THUS...COMBINED WITH MODEL GUIDANCE...CONTINUED WITH TEMPERATURES IN
THE LOWER 60S ACROSS THE NORTH TO NEAR 70 IN NORTH CENTRAL KANSAS
FOR SATURDAY. SATURDAY LOOKS TO BE SHAPING INTO A FAIRLY UNPLEASANT
DAY...WITH MOSTLY CLOUDY SKIES AND COOLER TEMPERATURES. TO ADD TO
THE MIX...STRONG NORTHWEST WINDS SUSTAINED NEAR 20 KTS CAN BE
EXPECTED...AND WITH SOME MIXING WILL LEAD TO GUSTS NEAR 30 KTS.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 319 PM CDT FRI MAY 31 2013
MAIN FORECAST CONCERNS WILL BE CHANCES FOR THUNDERSTORMS AND
TEMPERATURES.
AN UPPER LEVEL SHORT WAVE RIDGE WILL MOVE ACROSS THE AREA SATURDAY
NIGHT THROUGH SUNDAY NIGHT. DURING THIS TIME DRY CONDITIONS ARE
EXPECTED. A SURFACE HIGH WILL SETTLE INTO THE AREA SATURDAY NIGHT
AND KEEP WINDS LIGHT AND TEMPERATURES WILL DROP TO THE 40S. BY
SUNDAY THE SURFACE HIGH WILL MOVE OFF TO THE EAST. WINDS WILL TURN
TO THE SOUTH AND AS THE PRESSURE GRADIENT TIGHTENS...THE WINDS WILL
INCREASE DURING THE DAY ON SUNDAY. TEMPERATURES WILL BE WARMER FOR
SUNDAY AND SUNDAY NIGHT.
FOR MONDAY THROUGH FRIDAY ANOTHER UPPER LEVEL LOW WILL WORK ITS WAY
FROM THE PACIFIC NORTHWEST...THROUGH THE NORTHERN ROCKIES AND INTO
THE NORTHERN PLAINS. THIS IS A SIMILAR TRACK TO THE ONE FROM THE
PAST WEEK. BY MONDAY THE UPPER LOW STARTS TO SEND THE FIRST SHORT
WAVE INTO THE AREA AND BRINGS A CHANCE FOR THUNDERSTORMS. MODELS
BRING SEVERAL SHORT WAVES THROUGH THE AREA DURING THE WEEK. THERE
ARE SOME MINOR TIMING DIFFERENCES BETWEEN THE MODELS. THE CHANCE
FOR THUNDERSTORMS CONTINUES DURING THE WORK WEEK AS THE UPPER LOW
CONTINUES TO SEND SHORT WAVES INTO THE AREA. IT WILL NOT BE RAINING
ALL OF THE TIME AND THERE MAY BE TIMES WHERE SOME LOCATIONS DO NOT
HAVE ANY PRECIPITATION DURING SOME PERIODS... BUT THERE IS AT LEAST
A SMALL CHANCE EVERY DAY. THE BEST CHANCES SHOULD BE DURING THE
AFTERNOON AND INTO THE OVERNIGHT HOURS.
SOME OF THE STORMS COULD BE SEVERE DURING THIS PERIOD. THE BEST
CHANCE FOR SEVERE WILL BE TUESDAY AND TUESDAY NIGHT WHEN THE MUCAPE
APPROACHES 2500 J/KG. THERE COULD BE SOME ISOLATED SEVERE AT OTHER
TIMES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1242 PM CDT FRI MAY 31 2013
WHILE VFR CONDITIONS WILL CONTINUE THROUGHOUT MOST OF THE TAF
PERIOD...THERE IS AT LEAST SOME CONCERN FOR MVFR CEILINGS TOWARDS
THE END OF THE PERIOD. AN UPPER LEVEL LOW PRESSURE SYSTEM CENTERED
ACROSS THE DAKOTAS THIS MORNING WILL CONTINUE TO HAVE AN EFFECT ON
THE PLAINS THROUGHOUT THE PERIOD. LATEST SATELLITE IMAGERY
INDICATES A CUMULUS FIELD DEVELOPING ACROSS MOST OF THE
NORTHWESTERN HALF OF NEBRASKA. CURRENT THINKING IS THAT THESE
CLOUDS WILL BEGIN TO SHIFT THROUGH THE TAF SITE AFTER 0Z...WITH
LOWERING CLOUD BASES THEREAFTER. COMBINED WITH THESE CLOUDS...AN
ASSOCIATED TROUGH AXIS WILL ALSO PUSH THROUGH THE PLAINS ROUGHLY
AROUND 6Z...WHICH WILL HELP BRING A SLIGHT WIND SHIFT TO THE
NORTHWEST. LATEST MODEL TRENDS INDICATE AT LEAST SOME CHANCE THAT
SHOWERS ASSOCIATED WITH THIS TROUGH AXIS WILL BE OVER OR JUST
NORTH OF THE TAF SITE BY THE MORNING HOURS ON SATURDAY. THUS
CONTINUED WITH LIGHT RAIN SHOWER MENTION AFTER 10Z SATURDAY.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...SALTZMAN
LONG TERM...JCB
AVIATION...SALTZMAN
AREA FORECAST DISCUSSION
NWS BUFFALO NY
515 PM EDT FRI MAY 31 2013
.SYNOPSIS...
A HOT AND HUMID AIRMASS WILL REMAIN IN PLACE THROUGH THE FIRST HALF
OF THE WEEKEND WITH AT LEAST SCATTERED SHOWERS THUNDERSTORMS TONIGHT
AND SATURDAY. THE HIGHEST THREAT FOR RAINFALL WILL BE LATER
SATURDAY NIGHT AND SUNDAY AS A COLD FRONT CROSSES THE REGION. THIS
FRONT WILL USHER IN A COOLER AND DRIER AIRMASS FOR THE FIRST HALF OF
NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AN UPPER LEVEL RIDGE IS OFF THE EAST COAST WITH MOISTURE BEING
ADVECTED ACROSS THE OHIO VALLEY TOWARD NY. SCATTERED CONVECTION
OVER CENTRAL OH MATCHES 00Z SSEO NICELY WHILE EACH CONSECUTIVE
RUN OF THE HRRR SEEMS TO BE MISSING THE LEADING LINE. SO BASED OFF
THE 00Z SSEO AND TO SOME EXTENT THE 12Z NAM...BUT PRIMARILY
SATELLITE/OBSERVATION EXTRAPOLATION...EXPECT A FAIRLY DISORGANIZED
LINE OF THUNDERSTORMS TO DEVELOP LATER THIS AFTERNOON AND WORK ITS
WAY INTO THE SOUTHERN TIER AND THEN NIAGARA FRONTIER EARLY THIS
EVENING...BEFORE WEAKENING OR COMPLETELY FALLING APART OVER THE
GENESEE VALLEY/FINGER LAKES REGION. THIS WILL LEAVE QUITE A BIT OF
CLOUD COVER OVER THE REGION...AND THUS EXPECT LOWS TO GET STUCK IN
THE UPPER 60S TO NEAR 70 FOR MOST LOCATIONS...A BIT ABOVE MOST
GUIDANCE.
EXTENSIVE CLOUD COVER WILL CONTINUE INTO SATURDAY IN THE MOIST AND
UNSTABLE ATMOSPHERE. THIS WILL LIMIT DAYTIME HIGHS FROM GETTING TOO
HIGH...WITH MOST AREAS IN THE LOW TO MID 80S. THE CLOUD COVER WILL
ALSO PREVENT WIDESPREAD CONVECTION. INSTEAD...EXPECT HIT/MISS
SHOWERS TO DEVELOP. INITIATION AND EVENTUAL LOCATION WILL BE NEARLY
IMPOSSIBLE TO PINPOINT AS BOTH LOCAL MESOSCALE BOUNDARIES /LAKE
BREEZES/ AND GENERAL SYNOPTIC SCALE LIFT MAY FORCE THUNDERSTORM
DEVELOPMENT. WILL SLOWLY INCREASE THE PROBABILITY OF PRECIPITATION
INTO THE AFTERNOON...WITH INCREASING PRECIPITABLE
WATER...INSTABILITY AND THE APPROACHING COLD FRONT CREATING A BETTER
CHANCE FOR CONVECTION WITH TIME.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
IT WILL BE A WARM AND HUMID NIGHT ON SATURDAY NIGHT WITH OVERNIGHT
LOW TEMPS IN THE UPPER 60S ACROSS THE HIGHLANDS OF THE SOUTHERN TIER
AND THE TUG HILL PLATEAU WITH LOWER 70S FOR THE LAKE PLAINS AND
URBAN AREAS. IT WILL ALSO BECOME RATHER BREEZY WITH THE TIGHTENING
PRESSURE GRADIENT AHEAD OF THE APPROACHING COLD FRONT...WHICH WILL
HELP TO HOLD THE TEMPS UP THROUGH THE NIGHT.
PRECIP WILL PRECEDE THE COLD FRONT WITH THE 40 KNOT 850MB JET
FEEDING THE CONVECTION AND PROVIDING LOW LEVEL CONVERGENCE.
PRECIPITABLE WATER VALUES INCREASE TO NEARLY ONE AND THREE QUARTERS
OF AN INCH WITH HIGH PRECIP EFFICIENCY AND INDICATIONS OF TRAINING
STORMS ALONG THE FRONT. WILL CARRY CATEGORICAL POPS SATURDAY NIGHT
THROUGH SUNDAY AS THE FRONT AND PRECEDENT PRECIP CROSS THE REGION.
TEMPS ON SUNDAY WILL BE IN THE MID 70S TO LOW 80S...LIMITED BY THE
PRECIP AND THE PASSAGE OF THE COLD FRONT. PRECIP SHOULD TAPER OFF
QUICKLY WITH THE FRONTAL PASSAGE WITH ONLY SCATTERED SHOWERS
TRAILING THE FRONT. SKIES WILL START TO CLEAR ON MONDAY AS HIGH
PRESSURE NOSES IN FROM THE WEST WITH MUCH COOLER TEMPS IN THE MID TO
UPPER 60S...THEN CLEARING AND VERY COOLER MONDAY NIGHT WITH LOWS IN
THE 40S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
COOLER CANADIAN HIGH PRESSURE ACROSS SOUTHERN ONTARIO WILL RESULT IN
SUNNY SKIES AND COOLER THAN NORMAL TEMPERATURES...THE COOLEST TEMPS
ON TUESDAY THEN A WARMING TREND THROUGH THE WEEK. MEANWHILE...WE CAN
ANTICIPATE GENERALLY RAINFREE WEATHER FOR TUESDAY THROUGH WEDNESDAY
NIGHT. AN UPPER LOW PASSING EASTWARD ACROSS WESTERN ONTARIO WILL
BRING A CHANCE OF SHOWERS AND THUNDERSTORMS THURSDAY AND FRIDAY AS A
WARMER AND INCREASINGLY MORE HUMID SOUTHERLY FLOW DEVELOPS.
PRECIPITABLE WATER VALUES WILL INCREASE FROM AROUND A HALF INCH AT
MID WEEK TO MORE THEN AN INCH AND A HALF BY THE END OF THE WEEK.
TEMPS WILL CLIMB FROM THE 60S ON TUESDAY TO THE LOWER TO MID 70S ON
WEDNESDAY...AND THE MID 70S ON THURSDAY AND FRIDAY. OVERNIGHT LOW
TEMPS WILL ALSO RETURN TO A NEARLY NORMAL TREND WITH 40S TUESDAY
NIGHT TEMPERING TO THE LOWER TO MID 50S THURSDAY NIGHT...EVEN SOME
UPPER 50S POSSIBLE.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
VFR CONDITIONS EXPECTED THROUGH 18Z SATURDAY...ALBEIT WITH A FEW
ROUNDS OF CONVECTION. THE FIRST WEAKLY ORGANIZED AREA LIFTING
ACROSS OHIO AND EXPECT IT TO WORK ITS WAY INTO WESTERN NY BEFORE
WEAKENING AND/OR FALLING APART OVERNIGHT AS IT MOVES INTO THE
FINGER LAKES/GENESEE VALLEY REGION. LOCAL MVFR IS POSSIBLE WITH
THIS...BUT FOR NOW WILL KEEP ALL TAFS VFR WITHOUT AN MENTION OF
TS. CONVECTION ON SATURDAY SHOULD IN GENERAL HOLD OFF UNTIL AFTER
18Z...ALTHOUGH SOME SHOWER DEVELOPMENT IS POSSIBLE OVER FAR
WESTERN NY BEFORE THAT TIME. MOST OF THE CONVECTION AND
PRECIPITATION IS EXPECTED LATE SATURDAY EVENING/OVERNIGHT AS A
COLD FRONT MOVES ACROSS THE REGION.
OUTLOOK...
SUNDAY...VFR MUCH OF THE TIME...BUT OCCASIONAL SHOWERS AND
THUNDERSTORMS WILL PRODUCE LOCAL MVFR/IFR AT TIMES.
MONDAY-WEDNESDAY...VFR.
&&
.MARINE...
RELATIVELY LIGHT WINDS WILL CONTINUE THROUGH SATURDAY AS A GENERAL
SOUTH TO SOUTHWEST FLOW REMAINS IN PLACE AROUND A BERMUDA HIGH
PARKED OFF THE SOUTHEAST COAST. STRONG DIFFERENTIAL HEATING AND
RELATIVELY LIGHT SYNOPTIC SCALE FLOW WILL ALLOW LOCAL LAKE BREEZES
TO DEVELOP SATURDAY AFTERNOON...MAINLY ON THE EAST HALF OF LAKE
ONTARIO WITH WINDS BECOMING LOCALLY ONSHORE.
AN AREA OF LOW PRESSURE WILL PASS BY TO THE NORTH OF THE REGION
SUNDAY WITH A COLD FRONT CROSSING THE LOWER LAKES. WINDS WILL
INCREASE OUT OF THE SOUTHWEST ALONG AND BEHIND THIS COLD FRONT...
WITH CONDITIONS REACHING SMALL CRAFT ADVISORY CRITERIA.
&&
.CLIMATE...
RECORD HIGH FOR WATERTOWN TIED TODAY. 88 DEGREES SET IN 2010.
E
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...ZAFF
NEAR TERM...LEVAN/ZAFF
SHORT TERM...WCH
LONG TERM...WCH
AVIATION...LEVAN/ZAFF
MARINE...ZAFF
CLIMATE...HITCHCOCK
AREA FORECAST DISCUSSION
NWS BUFFALO NY
252 PM EDT FRI MAY 31 2013
.SYNOPSIS...
A HOT AND HUMID AIRMASS WILL REMAIN IN PLACE THROUGH THE FIRST HALF
OF THE WEEKEND WITH AT LEAST SCATTERED SHOWERS THUNDERSTORMS TONIGHT
AND SATURDAY. THE HIGHEST THREAT FOR RAINFALL WILL BE LATER
SATURDAY NIGHT AND SUNDAY AS A COLD FRONT CROSSES THE REGION. THIS
FRONT WILL USHER IN A COOLER AND DRIER AIRMASS FOR THE FIRST HALF OF
NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AN UPPER LEVEL RIDGE IS OFF THE EAST COAST THIS AFTERNOON WITH
MOISTURE BEING ADVECTED ACROSS THE OHIO VALLEY TOWARD NY. SCATTERED
CONVECTION FORMING OVER CENTRAL OH MATCHES 00Z SSEO NICELY WHILE
EACH CONSECUTIVE RUN OF THE HRRR SEEMS TO BE MISSING THE LEADING
LINE. SO BASED OFF THE 00Z SSEO AND TO SOME EXTENT THE 12Z
NAM...BUT PRIMARILY SATELLITE/OBSERVATION EXTRAPOLATION...EXPECT A
FAIRLY DISORGANIZED LINE OF THUNDERSTORMS TO DEVELOP LATER THIS
AFTERNOON AND WORK ITS WAY INTO THE SOUTHERN TIER AND THEN NIAGARA
FRONTIER EARLY THIS EVENING...BEFORE WEAKENING OR COMPLETELY FALLING
APART OVER THE GENESEE VALLEY/FINGER LAKES REGION. THIS WILL LEAVE
QUITE A BIT OF CLOUD COVER OVER THE REGION...AND THUS EXPECT LOWS TO
GET STUCK IN THE UPPER 60S TO NEAR 70 FOR MOST LOCATIONS...A BIT
ABOVE MOST GUIDANCE.
EXTENSIVE CLOUD COVER WILL CONTINUE INTO SATURDAY IN THE MOIST AND
UNSTABLE ATMOSPHERE. THIS WILL LIMIT DAYTIME HIGHS FROM GETTING TOO
HIGH...WITH MOST AREAS IN THE LOW TO MID 80S. THE CLOUD COVER WILL
ALSO PREVENT WIDESPREAD CONVECTION. INSTEAD...EXPECT HIT/MISS
SHOWERS TO DEVELOP. INITIATION AND EVENTUAL LOCATION WILL BE NEARLY
IMPOSSIBLE TO PINPOINT AS BOTH LOCAL MESOSCALE BOUNDARIES /LAKE
BREEZES/ AND GENERAL SYNOPTIC SCALE LIFT MAY FORCE THUNDERSTORM
DEVELOPMENT. WILL SLOWLY INCREASE THE PROBABILITY OF PRECIPITATION
INTO THE AFTERNOON...WITH INCREASING PRECIPITABLE
WATER...INSTABILITY AND THE APPROACHING COLD FRONT CREATING A BETTER
CHANCE FOR CONVECTION WITH TIME.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
IT WILL BE A WARM AND HUMID NIGHT ON SATURDAY NIGHT WITH OVERNIGHT
LOW TEMPS IN THE UPPER 60S ACROSS THE HIGHLANDS OF THE SOUTHERN TIER
AND THE TUG HILL PLATEAU WITH LOWER 70S FOR THE LAKE PLAINS AND
URBAN AREAS. IT WILL ALSO BECOME RATHER BREEZY WITH THE TIGHTENING
PRESSURE GRADIENT AHEAD OF THE APPROACHING COLD FRONT...WHICH WILL
HELP TO HOLD THE TEMPS UP THROUGH THE NIGHT.
PRECIP WILL PRECEDE THE COLD FRONT WITH THE 40 KNOT 850MB JET
FEEDING THE CONVECTION AND PROVIDING LOW LEVEL CONVERGENCE.
PRECIPITABLE WATER VALUES INCREASE TO NEARLY ONE AND THREE QUARTERS
OF AN INCH WITH HIGH PRECIP EFFICIENCY AND INDICATIONS OF TRAINING
STORMS ALONG THE FRONT. WILL CARRY CATEGORICAL POPS SATURDAY NIGHT
THROUGH SUNDAY AS THE FRONT AND PRECEDENT PRECIP CROSS THE REGION.
TEMPS ON SUNDAY WILL BE IN THE MID 70S TO LOW 80S...LIMITED BY THE
PRECIP AND THE PASSAGE OF THE COLD FRONT. PRECIP SHOULD TAPER OFF
QUICKLY WITH THE FRONTAL PASSAGE WITH ONLY SCATTERED SHOWERS
TRAILING THE FRONT. SKIES WILL START TO CLEAR ON MONDAY AS HIGH
PRESSURE NOSES IN FROM THE WEST WITH MUCH COOLER TEMPS IN THE MID TO
UPPER 60S...THEN CLEARING AND VERY COOLER MONDAY NIGHT WITH LOWS IN
THE 40S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
COOLER CANADIAN HIGH PRESSURE ACROSS SOUTHERN ONTARIO WILL RESULT IN
SUNNY SKIES AND COOLER THAN NORMAL TEMPERATURES...THE COOLEST TEMPS
ON TUESDAY THEN A WARMING TREND THROUGH THE WEEK. MEANWHILE...WE CAN
ANTICIPATE GENERALLY RAINFREE WEATHER FOR TUESDAY THROUGH WEDNESDAY
NIGHT. AN UPPER LOW PASSING EASTWARD ACROSS WESTERN ONTARIO WILL
BRING A CHANCE OF SHOWERS AND THUNDERSTORMS THURSDAY AND FRIDAY AS A
WARMER AND INCREASINGLY MORE HUMID SOUTHERLY FLOW DEVELOPS.
PRECIPITABLE WATER VALUES WILL INCREASE FROM AROUND A HALF INCH AT
MID WEEK TO MORE THEN AN INCH AND A HALF BY THE END OF THE WEEK.
TEMPS WILL CLIMB FROM THE 60S ON TUESDAY TO THE LOWER TO MID 70S ON
WEDNESDAY...AND THE MID 70S ON THURSDAY AND FRIDAY. OVERNIGHT LOW
TEMPS WILL ALSO RETURN TO A NEARLY NORMAL TREND WITH 40S TUESDAY
NIGHT TEMPERING TO THE LOWER TO MID 50S THURSDAY NIGHT...EVEN SOME
UPPER 50S POSSIBLE.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
VFR CONDITIONS EXPECTED THROUGH 18Z SATURDAY...ALBEIT WITH A FEW
ROUNDS OF CONVECTION. THE FIRST WEAKLY ORGANIZED AREA IS FORMING
OVER OH...AND EXPECT IT TO WORK ITS WAY INTO WESTERN NY BEFORE
WEAKENING AND/OR FALLING APART OVERNIGHT AS IT MOVES INTO THE FINGER
LAKES/GENESEE VALLEY REGION. LOCAL MVFR IS POSSIBLE WITH
THIS...BUT FOR NOW WILL KEEP ALL TAFS VFR WITHOUT AN MENTION OF TS.
CONVECTION ON SATURDAY SHOULD IN GENERAL HOLD OFF UNTIL AFTER
18Z...ALTHOUGH SOME SHOWER DEVELOPMENT IS POSSIBLE OVER FAR WESTERN
NY BEFORE THAT TIME. MOST OF THE CONVECTION AND PRECIPITATION IS
EXPECTED LATE SATURDAY EVENING/OVERNIGHT AS A COLD FRONT MOVES
ACROSS THE REGION.
OUTLOOK...
SUNDAY...VFR MUCH OF THE TIME...BUT OCCASIONAL SHOWERS AND
THUNDERSTORMS WILL PRODUCE LOCAL MVFR/IFR AT TIMES.
MONDAY-WEDNESDAY...VFR.
&&
.MARINE...
RELATIVELY LIGHT WINDS WILL CONTINUE THROUGH SATURDAY AS A GENERAL
SOUTH TO SOUTHWEST FLOW REMAINS IN PLACE AROUND A BERMUDA HIGH
PARKED OFF THE SOUTHEAST COAST. STRONG DIFFERENTIAL HEATING AND
RELATIVELY LIGHT SYNOPTIC SCALE FLOW WILL ALLOW LOCAL LAKE BREEZES
TO DEVELOP SATURDAY AFTERNOON...MAINLY ON THE EAST HALF OF LAKE
ONTARIO WITH WINDS BECOMING LOCALLY ONSHORE.
AN AREA OF LOW PRESSURE WILL PASS BY TO THE NORTH OF THE REGION
SUNDAY WITH A COLD FRONT CROSSING THE LOWER LAKES. WINDS WILL
INCREASE OUT OF THE SOUTHWEST ALONG AND BEHIND THIS COLD FRONT...
WITH CONDITIONS REACHING SMALL CRAFT ADVISORY CRITERIA.
&&
.CLIMATE...
EARLY SEASON HEAT WILL CONTINUE TODAY. RECORD HIGHS FOR MAY 31 ARE
90 AT BUFFALO SET IN 1919...91 IN ROCHESTER SET IN 2011...AND 88
IN WATERTOWN SET IN 2010. AT BUFFALO...A SOUTHWEST FLOW OFF LAKE
ERIE WILL KEEP TEMPS WELL SHY OF THE RECORD. BOTH ROCHESTER AND
WATERTOWN WILL GET VERY CLOSE...WITH CURRENT FORECAST HIGHS WITHIN
A DEGREE OR SO OF THE RECORDS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...HITCHCOCK/ZAFF
NEAR TERM...ZAFF
SHORT TERM...WCH
LONG TERM...WCH
AVIATION...ZAFF
MARINE...HITCHCOCK/ZAFF
CLIMATE...HITCHCOCK
AREA FORECAST DISCUSSION
NWS BUFFALO NY
200 PM EDT FRI MAY 31 2013
.SYNOPSIS...
A HOT AND HUMID AIRMASS WILL REMAIN IN PLACE THROUGH THE FIRST HALF
OF THE WEEKEND WITH AT LEAST SCATTERED SHOWERS THUNDERSTORMS TONIGHT
AND SATURDAY. THE HIGHEST THREAT FOR RAINFALL WILL BE LATER
SATURDAY NIGHT AND SUNDAY AS A COLD FRONT CROSSES THE REGION. THIS
FRONT WILL USHER IN A COOLER AND DRIER AIRMASS FOR THE FIRST HALF OF
NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AN UPPER LEVEL RIDGE IS OFF THE EAST COAST THIS AFTERNOON WITH
MOISTURE BEING ADVECTED ACROSS THE OHIO VALLEY TOWARD NY. SCATTERED
CONVECTION FORMING OVER CENTRAL OH MATCHES 00Z SSEO NICELY WHILE
EACH CONSECUTIVE RUN OF THE HRRR SEEMS TO BE MISSING THE LEADING
LINE. SO BASED OFF THE 00Z SSEO AND TO SOME EXTENT THE 12Z
NAM...BUT PRIMARILY SATELLITE/OBSERVATION EXTRAPOLATION...EXPECT A
FAIRLY DISORGANIZED LINE OF THUNDERSTORMS TO DEVELOP LATER THIS
AFTERNOON AND WORK ITS WAY INTO THE SOUTHERN TIER AND THEN NIAGARA
FRONTIER EARLY THIS EVENING...BEFORE WEAKENING OR COMPLETELY FALLING
APART OVER THE GENESEE VALLEY/FINGER LAKES REGION. THIS WILL LEAVE
QUITE A BIT OF CLOUD COVER OVER THE REGION...AND THUS EXPECT LOWS TO
GET STUCK IN THE UPPER 60S TO NEAR 70 FOR MOST LOCATIONS...A BIT
ABOVE MOST GUIDANCE.
EXTENSIVE CLOUD COVER WILL CONTINUE INTO SATURDAY IN THE MOIST AND
UNSTABLE ATMOSPHERE. THIS WILL LIMIT DAYTIME HIGHS FROM GETTING TOO
HIGH...WITH MOST AREAS IN THE LOW TO MID 80S. THE CLOUD COVER WILL
ALSO PREVENT WIDESPREAD CONVECTION. INSTEAD...EXPECT HIT/MISS
SHOWERS TO DEVELOP. INITIATION AND EVENTUAL LOCATION WILL BE NEARLY
IMPOSSIBLE TO PINPOINT AS BOTH LOCAL MESOSCALE BOUNDARIES /LAKE
BREEZES/ AND GENERAL SYNOPTIC SCALE LIFT MAY FORCE THUNDERSTORM
DEVELOPMENT. WILL SLOWLY INCREASE THE PROBABILITY OF PRECIPITATION
INTO THE AFTERNOON...WITH INCREASING PRECIPITABLE
WATER...INSTABILITY AND THE APPROACHING COLD FRONT CREATING A BETTER
CHANCE FOR CONVECTION WITH TIME.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
VERY WARM AND SOMEWHAT HUMID CONDITIONS WILL PREVAIL ON SATURDAY AS
THE DEEP LAYERED SOUTHWEST FLOW AROUND THE BERMUDA HIGH REMAINS IN
CONTROL. HOWEVER...THERE WILL BE A BETTER CHANCE FOR SOME CONVECTION
AS THE APPROACHING UPPER MIDWEST TROUGH BEGINS TO ERODE THE EASTERN
UPPER LEVEL RIDGE AND ALLOWS SOME OF THE UPSTREAM CONVECTION TO
ADVECT EAST ACROSS OUR CWA. IN ADDITION...OUR AREA WILL COME UNDER
THE INFLUENCE OF ADDITIONAL LIFT FROM A JET STREAK THAT WILL BE
ARCING FROM THE CENTRAL GREAT LAKES TO SOUTHERN QUEBEC. WILL
MAINTAIN CHANCE POPS FOR MEASURABLE PCPN SINCE THE BEST DYNAMICS
ASSOCIATED WITH THE UPPER TROUGH AND LOW LEVEL MOISTURE CONVERGENCE
ARE FORECAST TO STAY TO OUR WEST. RIGHT NOW IT LOOKS LIKE MOST
CONVECTION WILL STAY BELOW SEVERE LEVELS WITH INCREASING CLOUD COVER
EXPECTED TO LIMIT INSTABILITY.
THE AFOREMENTIONED UPPER LEVEL JET DYNAMICS WILL REMAIN IN PLACE
SATURDAY NIGHT...WHILE A 50 KNOT LOW LEVEL JET HEADS EAST INTO
WESTERN NEW YORK IN ADVANCE OF THE COLD FRONT THAT WILL BE WORKING
EAST TOWARD THE LOWER GREAT LAKES. THE IMPROVING LARGE SCALE LIFT
WILL SUPPORT MORE WIDESPREAD SHOWERS AND THUNDERSTORMS...
...PARTICULARLY OVER OUR WESTERN COUNTIES. FORECAST PWAT VALUES IN
EXCESS OF 1.5 INCHES WILL LEAD TO A HIGHER POTENTIAL FOR LOCALLY
HEAVY RAIN IN ANY CONVECTION. THE DEEP SOUTHERLY FLOW AHEAD OF THE
FRONT WILL MAKE THIS THE WARMEST NIGHT WITH MANY LOCATIONS ALONG THE
LAKE PLAINS STRUGGLING TO DROP BELOW 70 DEGREES.
THE SURFACE LOW THAT IS ASSOCIATED WITH THE APPROACHING UPPER LEVEL
TROUGH WILL TRACK NORTH OF NEW YORK STATE ON SUNDAY AND SWEEP THE
FIRST OF TWO COLD FRONTS ACROSS THE WESTERN COUNTIES DURING THE
MORNING...AND ACROSS THE EASTERN LAKE ONTARIO REGION DURING THE
MIDDAY. THIS TIMING OF THE FRONTAL PASSAGE WILL SHORTEN THE DURATION
OF WIDESPREAD PCPN...WHILE LIKELY REDUCING THE THREAT FOR SEVERE
CONVECTION. HOWEVER...PWAT VALUES >1.5 INCHES SHOULD STILL PROMOTE
HEAVY RAINS THROUGH MIDDAY. A DRY SLOT WILL WORK IN BEHIND THE COLD
FRONT...HELPING TO REDUCE THE POPS TO LOW CHANCE. TEMPERATURES
SUNDAY AFTERNOON WILL GENERALLY BE IN THE 70S.
WHEN THE SECONDARY COLD FRONT CROSSES WESTERN AND CENTRAL NEW YORK
SUNDAY EVENING...THE DEEPEST MOISTURE ASSOCIATED WITH THE FIRST
FRONT WILL HAVE MOVED EAST OF OUR AREA. AS A RESULT...EXPECT MAINLY
DRY CONDITIONS TO PREVAIL WITH THIS FRONT. OF GREATER NOTE...IT WILL
TURN COOLER AND LESS HUMID WITH EARLY MORNING TEMPERATURES COOLING
INTO THE LOWER TO MID 50S...RIGHT WHERE THEY SHOULD BE AT THIS POINT
IN THE SEASON.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
A LOW AMPLITUDE FLOW ACROSS THE COUNTRY DURING THIS PERIOD WILL
RESULT IN NEAR TO BELOW NORMAL TEMPERATURES...WITH THE COOLEST
CONDITIONS COMING AT THE START OF THE NEW WORK WEEK. MEANWHILE...WE
CAN ANTICIPATE GENERALLY RAINFREE WEATHER.
THE BASE OF A DIGGING H5 TROUGH WILL SWING ACROSS TO THE NORTH OF LK
ONTARIO ON MONDAY. LOW LEVEL RIDGING AND A WEALTH OF DRY AIR UNDER
THIS APPROACHING TROUGH SHOULD DISCOURAGE ANY PCPN...BUT WILL KEEP
SLGT CHC POPS IN PLACE ACROSS THE NORTH COUNTRY WHERE HGT FALLS WILL
BE THE MOST SIGNIFICANT. OUTSIDE OF THIS LONE `FLY IN THE
OINTMENT`...MONDAY SHOULD BE PARTLY TO MOSTLY SUNNY AND SEASONABLY
COOL WITH AFTERNOON TEMPERATURES IN THE 60S.
HIGH PRESSURE CENTERED OVER JAMES BAY WILL THEN NOSE SOUTH ACROSS
THE LOWER GREAT LAKES MONDAY NIGHT THROUGH WEDNESDAY...WITH H85
TEMPS GENERALLY IN THE UPPER SINGLE DIGITS. THIS WILL KEEP
PLEASANTLY COOL CONDITIONS IN PLACE A BIT LONGER...BUT TEMPERATURES
WILL MODERATE DURING THE SECOND HALF OF THE WEEK.
THE AFOREMENTIONED SFC HIGH WILL MOVE TO THE CANADIAN MARITIMES
WEDNESDAY NIGHT AND THURSDAY WHILE A SHORTWAVE WILL DIG ACROSS THE
NORTHERN PLAINS. THIS WILL SET UP A SOUTH TO SOUTHEAST FLOW OF
MILDER AIR ACROSS OUR REGION...PROMOTING MILDER WEATHER WITH DAYTIME
HIGHS CLIMBING BACK ABOVE NORMAL.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
VFR CONDITIONS EXPECTED THROUGH 18Z SATURDAY...ALBEIT WITH A FEW
ROUNDS OF CONVECTION. THE FIRST WEAKLY ORGANIZED AREA IS FORMING
OVER OH...AND EXPECT IT TO WORK ITS WAY INTO WESTERN NY BEFORE
WEAKENING AND/OR FALLING APART OVERNIGHT AS IT MOVES INTO THE FINGER
LAKES/GENESEE VALLEY REGION. LOCAL MVFR IS POSSIBLE WITH
THIS...BUT FOR NOW WILL KEEP ALL TAFS VFR WITHOUT AN MENTION OF TS.
CONVECTION ON SATURDAY SHOULD IN GENERAL HOLD OFF UNTIL AFTER
18Z...ALTHOUGH SOME SHOWER DEVELOPMENT IS POSSIBLE OVER FAR WESTERN
NY BEFORE THAT TIME. MOST OF THE CONVECTION AND PRECIPITATION IS
EXPECTED LATE SATURDAY EVENING/OVERNIGHT AS A COLD FRONT MOVES
ACROSS THE REGION.
OUTLOOK...
SUNDAY...VFR MUCH OF THE TIME...BUT OCCASIONAL SHOWERS AND
THUNDERSTORMS WILL PRODUCE LOCAL MVFR/IFR AT TIMES.
MONDAY-WEDNESDAY...VFR.
&&
.MARINE...
RELATIVELY LIGHT WINDS WILL CONTINUE THROUGH SATURDAY AS A GENERAL
SOUTH TO SOUTHWEST FLOW REMAINS IN PLACE AROUND A BERMUDA HIGH
PARKED OFF THE SOUTHEAST COAST. STRONG DIFFERENTIAL HEATING AND
RELATIVELY LIGHT SYNOPTIC SCALE FLOW WILL ALLOW LOCAL LAKE BREEZES
TO DEVELOP SATURDAY AFTERNOON...MAINLY ON THE EAST HALF OF LAKE
ONTARIO WITH WINDS BECOMING LOCALLY ONSHORE.
AN AREA OF LOW PRESSURE WILL PASS BY TO THE NORTH OF THE REGION
SUNDAY WITH A COLD FRONT CROSSING THE LOWER LAKES. WINDS WILL
INCREASE OUT OF THE SOUTHWEST ALONG AND BEHIND THIS COLD FRONT...
WITH CONDITIONS REACHING SMALL CRAFT ADVISORY CRITERIA.
&&
.CLIMATE...
EARLY SEASON HEAT WILL CONTINUE TODAY. RECORD HIGHS FOR MAY 31 ARE
90 AT BUFFALO SET IN 1919...91 IN ROCHESTER SET IN 2011...AND 88
IN WATERTOWN SET IN 2010. AT BUFFALO...A SOUTHWEST FLOW OFF LAKE
ERIE WILL KEEP TEMPS WELL SHY OF THE RECORD. BOTH ROCHESTER AND
WATERTOWN WILL GET VERY CLOSE...WITH CURRENT FORECAST HIGHS WITHIN
A DEGREE OR SO OF THE RECORDS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...HITCHCOCK/ZAFF
NEAR TERM...ZAFF
SHORT TERM...TJP
LONG TERM...TJP
AVIATION...ZAFF
MARINE...HITCHCOCK/ZAFF
CLIMATE...HITCHCOCK
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
305 PM EDT FRI MAY 31 2013
.SYNOPSIS...
BERMUDA HIGH PRESSURE WILL CONTINUE ACROSS THE CAROLINAS THROUGH THE
WEEKEND. A COLD FRONT WILL SLOWLY MOVE THROUGH THE AREA EARLY NEXT
WEEK...BRINGING THE HIGHEST POTENTIAL FOR SHOWERS AND THUNDERSTORMS
MONDAY AND TUESDAY. HIGH PRESSURE WILL SLOWLY BUILD SOUTHWARD AND
INTO THE AREA DURING THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM FRIDAY...BERMUDA HIGH PRESSURE WELL OFFSHORE EXTENDS
INTO THE EASTERN CAROLINAS FROM A CENTER OVER 1000 MILES OFFSHORE. A
LONG EASTERLY FETCH ACROSS THE CENTRAL ATLANTIC OCEAN IS BRINGING
WARM AND HUMID AIR ONSHORE. SHOWERS HAVE BEEN MUCH MORE WIDESPREAD
TODAY THAN YESTERDAY MAINLY DUE TO RICHER BOUNDARY LAYER MOISTURE
EXISTING WITHIN AN UNCAPPED AND UNSTABLE ATMOSPHERE. THIS CONVECTIVE
ACTIVITY IS TIED TO DAYTIME HEATING AND SHOULD QUICKLY DIMINISH THIS
EVENING WITH MAINLY CLEAR SKIES DEVELOPING BY 8-10 PM.
MUCH LIKE LAST NIGHT...HIGH DEWPOINTS WITHIN THE BOUNDARY LAYER AND
LIGHT SURFACE WINDS SHOULD ALLOW LOW STRATUS AND FOG TO DEVELOP LATE
TONIGHT...MAINLY ACROSS THE SAME AREAS AS LAST NIGHT. OVERNIGHT LOWS
SHOULD RUN NEAR TO PERHAPS TWO DEGREES WARMER THAN LAST NIGHT...
GENERALLY MID 60S MOST AREAS TO AROUND 70 ON THE BEACHES.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...HIGH PRESSURE WILL HOLD ON THROUGH THE
WEEKEND AS IT SLOWLY SLIPS FARTHER EAST. THE STRONG RIDGE OF HIGH
PRESSURE ALOFT WILL ALSO CONTINUE TO SHIFT EAST INTO THE ATLANTIC
WHILE A DEEPENING TROUGH MOVES IN FROM THE CENTRAL CONUS. THIS
TROUGH WILL PUSH A COLD FRONT EAST BUT WILL NOT REACH THE
CAROLINAS UNTIL MONDAY MORNING. AS THE RIDGE SLIPS EAST WE WILL
LOSE SOME OF OUR CAP ON CONVECTION AND SEE LOCALIZED SHWRS/TSTMS
THROUGH THE WEEKEND. BY SUNDAY THE WINDS WILL BE INCREASING OUT OF
THE SOUTH WHICH SHOULD PUSH SHWR DEVELOPMENT FARTHER WEST AND MAY
SEE FEWER SHOWERS OVER LOCAL CWA THROUGH THE AFTN. OVERALL EXPECT
A WARM AND HUMID SUMMER-LIKE AIR MASS TO REMAIN OVER THE AREA
THROUGH MUCH OF THE WEEKEND. SOUTHERLY WINDS WILL PICK UP
PRODUCING BREEZY WEATHER BY SUNDAY AFTERNOON. EXPECT CU TO BUILD
EACH AFTERNOON WITH BEST CONVERGENCE AND CHC OF CONVECTION ALONG
SEA BREEZE BOUNDARY AS IT PUSHES INLAND.
A DEEPER MOISTER SOUTHERLY FLOW WILL INCREASE THE OVERALL MOISTURE
THROUGH THE COLUMN BY THE END OF THE WEEKEND. PCP WATER VALUES
WILL REACH UP TO 1.5 INCHES INLAND EACH AFTERNOON AS SHWRS/TSTMS
FLARE UP BUT HEADING INTO LATE SUNDAY INTO SUNDAY NIGHT AHEAD OF
COLD FRONT...VALUES WILL REACH UP CLOSER TO 2 INCHES. CLOUDS WILL
INCREASE WITH SHOWERS AND THUNDERSTORMS INCREASING IN COVERAGE
SUNDAY NIGHT INTO MONDAY AS COLD FRONT APPROACHES FROM THE WEST.
THE WARM AND MOIST AIR MASS WILL CREATE MUCH LESS VARIATION IN DIURNAL
TEMPERATURE SWINGS. OVERNIGHT LOWS WILL ONLY DROP TO THE MID 60S
INLAND AND CLOSER TO 70 ALONG THE COAST. DAY TIME HIGHS WILL REACH
THE MID TO UPPER 80S...EXCEPT COOLER ALONG THE BEACHES.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 PM FRIDAY...WHAT WILL LIKELY BEGIN AS A VERY WET START TO
THE PERIOD WILL TRANSITION TO DRIER AND SEASONABLE CONDITIONS
THROUGH MUCH OF THE UPCOMING WEEK. THERE IS QUITE A BIT OF
UNCERTAINTY AT THE TAIL END OF THE PERIOD DUE TO INCREASED MOISTURE
ASSOCIATED WITH A POTENTIAL TROPICAL SYSTEM IN THE GOM.
BERMUDA HIGH PRESSURE WHICH HAS DOMINATED THE SYNOPTIC REGIME FOR
MORE THAN WEEK NOW WILL FINALLY BE DISPLACED BY EARLY TUESDAY THANKS
TO A COLD FRONT MOVING SLOWLY ACROSS THE SOUTHEAST. AHEAD OF THIS
BOUNDARY...PWATS RISE TO NEARLY 2 INCHES...WHICH IS APPROACHING +2SD
AND THE 99TH PERCENTILE FOR THE FIRST WEEK OF JUNE! THIS INCREDIBLY
MOIST ENVIRONMENT PAIRED WITH CONVERGENCE ALONG THE FRONT...SOME
DIFFLUENCE...ALBEIT RELATIVELY WEAK...WITHIN THE RIGHT ENTRANCE
REGION OF A 300MB JET STREAK...AND STRONG THETA-E RIDGING AHEAD OF
THE FRONT WILL SUPPORT WIDESPREAD SHOWERS WITH TSTMS ON MONDAY...AND
HAVE BUMPED POP TO LIKELY CWA-WIDE. THE HIGHEST POP IS EXPECTED LATE
MONDAY/MONDAY NIGHT.
FRONT MAY TAKE A WHILE TO CROSS THE AREA...AND THUS LOW-CHC POP IS
STILL WARRANTED INTO TUESDAY MORNING BEFORE SIGNIFICANT DRYING
OCCURS WITHIN THE COLUMN THANKS TO HIGH PRESSURE BUILDING DOWN FROM
THE NORTH. THIS WILL CREATE SEVERAL DAYS OF SEASONABLE EARLY-JUNE
WEATHER. LATE IN THE WEEK...HIGH PRESSURE SHIFTS OFFSHORE PUMPING
ATLANTIC MOISTURE BACK INTO THE AREA...AND DIURNAL CONVECTION WILL
BECOME INCREASINGLY LIKELY AGAIN. ADDITIONALLY...WHILE THE FAVORED
ECMWF KEEPS ANY TROPICAL MOISTURE WELL SW OF THE CAROLINAS...GFS
DOES SUGGEST SIGNIFICANT RAIN CHANCES BEGINNING FRIDAY AS MOISTURE
STREAMS OUT OF THE GOM. FOR NOW WILL LEAN HEAVILY ON THE ECMWF BUT
NOTE THAT MONITORING GUIDANCE EVOLUTION WILL BE IMPORTANT LEADING
INTO NEXT WEEKEND.
&&
.AVIATION /18Z FRIDAY THROUGH TUESDAY/...
AS OF 18Z...RADAR IMAGERY SHOWS SCATTERED SHOWERS/T-STORMS
DEVELOPING ALONG THE SEA BREEZE BOUNDARY THIS AFTN. HAVE INCLUDED
VCSH FOR KFLO/KLBT AS LATEST HRRR RUNS SHOW MORE SHOWERS DEVELOPING
INLAND LATER TODAY. OTHERWISE...VFR SHOULD PREVAIL WITH SCT/BKN CU
AND SSE WINDS AOB 10 KTS. MOSTLY CLEAR CONDITIONS TONIGHT AND PLENTY
OF LOW-LEVEL MOISTURE INDICATES FOG/STRATUS IS AGAIN LIKELY AFTER
06Z. SREF PROBS AND GUIDANCE SUGGEST IFR CIGS/VSBYS WILL BE MORE
WIDESPREAD INLAND...SIMILAR TO WHAT OCCURRED THIS MORNING. TEMPO IFR
IS ALSO QUITE POSSIBLE ALONG THE COAST...MOST LIKELY IN THE 09-12Z
RANGE. FOG/STRATUS SHOULD LIFT SOON AFTER 12Z SATURDAY.
EXTENDED OUTLOOK...EARLY MORNING MVFR/IFR CIGS/VSBYS POSSIBLE
THROUGH SUNDAY. SLIGHT CHANCE OF SHOWERS INLAND ON SUNDAY...WITH
BETTER PCPN CHANCES ACROSS THE CWA MONDAY AND TUESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM FRIDAY...BERMUDA HIGH PRESSURE CONTINUES TO EXTEND A
RIDGE AXIS WESTWARD ACROSS THE CAROLINAS AT NEARLY THE SAME LATITUDE
AS LAST NIGHT. THEREFORE IT SHOULD NOT BE SURPRISING THE ANTICIPATED
WIND DIRECTION AND SPEED TONIGHT IS VERY SIMILAR TO LAST NIGHT.
SOUTH WINDS 5-10 KNOTS SHOULD PREVAIL THROUGH THE NIGHT AFTER THIS
AFTERNOON`S SEA BREEZE CIRCULATION DIES DOWN BY 9-10 PM. SEAS ARE
AVERAGING 3 FEET ON THE BUOYS NEAR CAPE FEAR WITH A DOMINANT PERIOD
AROUND 8 SECONDS. THIS IS VERY WELL MODELED IN THE NOAA WAVEWATCH
MODEL WHICH SHOWS THIS SOUTHEAST SWELL CONTINUING UNCHANGED THROUGH
THE NIGHT.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...EXPECT SOUTHERLY RETURN FLOW TO CONTINUE
AROUND WESTERN PERIPHERY OF BERMUDA HIGH THROUGH THE WEEKEND. BY
SUNDAY AFTERNOON INTO SUNDAY NIGHT THE GRADIENT WILL BEGIN TO
TIGHTEN AS COLD FRONT APPROACHES THE CAROLINAS FROM THE WEST.
OVERALL EXPECT SOUTHERLY FLOW CLOSER TO 5 TO 10 KTS THROUGH THE
FIRST HALF OF THE WEEKEND AND UP TO 15 KTS BY SUN EVENING. THE
WAVE HEIGHTS WILL RESPOND TO INCREASE IN SOUTHERLY FLOW BY RISING
CLOSER TO 3 TO 4 FT BY SUN NIGHT. BASICALLY SEAS WILL HOLD
BETWEEN 2 AND 4 FT THROUGH THE WEEKEND. EXPECT A SLIGHT SPIKE UP
IN WINDS AND SEAS EACH AFTN AND A SLIGHT CHOP NEAR SHORE IN SEA
BREEZE EACH AFTERNOON.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 300 PM FRIDAY...PRE-FRONTAL REGIME TO START THE PERIOD WITH
GUSTY SOUTHERLY WINDS ONGOING ACROSS THE WATERS. SOUTHERLY WINDS OF
10-15 KTS WILL BE THE RULE MONDAY...BEFORE VEERING TO THE WEST EARLY
TUESDAY. DO NOT EXPECT WINDS TO BECOME NORTHERLY AS FRONT STALLS AND
WASHES OUT OVER THE AREA DURING TUESDAY...AND EVENTUALLY WILL BACK
TO THE E/SE...AND FINALLY THE NE ON WEDNESDAY AS HIGH PRESSURE
RIDGES DOWN THE COAST. WHILE WIND SPEEDS WILL BE RELATIVELY LIGHT
TUESDAY...THEY WILL INCREASE TO AROUND 15 KTS WITHIN THE PINCHED
GRADIENT WEDNESDAY.
WHILE A 2FT/8SEC SE SWELL WILL PERSIST AND SLOWLY DAMPEN THROUGH THE
PERIOD...WIND WAVES WILL SHOW AN INCREASING CONTRIBUTION TO THE
SPECTRUM...ESPECIALLY MON AND WED. SEAS WILL BE GENERALLY 2-4 FT BUT
WITH SOME ISOLATED 5 FTERS MONDAY EVE AHEAD OF THE COLD FRONT...AND
AGAIN ON WEDNESDAY WITH THE STRONGER E/NE WINDS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...RGZ
LONG TERM...JDW
AVIATION...BJR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
240 PM EDT FRI MAY 31 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN SOLIDLY OVER THE REGION THROUGH
SATURDAY... THEN SHIFT OFFSHORE SUNDAY. A COLD FRONT WILL SLOWLY
APPROACH FROM THE WEST SUNDAY...THEN CROSS THE REGION MONDAY AND
MONDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM FRIDAY...
OVERVIEW:
AN UPPER LEVEL RIDGE CENTERED ALONG THE SOUTHEAST AND MID-ATLANTIC
COAST WILL FURTHER WEAKEN THROUGH TONIGHT AS AN UPPER LEVEL LOW
CENTERED OVER THE NORTHERN PLAINS MOVES SLOWLY EAST INTO THE
NORTHERN MS RIVER VALLEY. A SFC-H85 RIDGE WILL PERSIST OFFSHORE OF
THE CAROLINAS...WITH AN INCREASINGLY MOIST SOUTHERLY RETURN FLOW
ACROSS THE REGION.
TEMPERATURES:
HIGHS TODAY APPEAR VERY SIMILAR TO THE PREVIOUS FEW DAYS GIVEN
LITTLE CHANGE IN THICKNESSES AND A VERY SIMILAR (ALBEIT INCREASINGLY
MOIST) AIRMASS. THE MAIN FACTORS W/REGARD TO HIGH TEMPS ARE APT TO
BE THE SEABREEZE APPROACHING FROM THE S/SE AND ISOLD CONVECTION
/OUTFLOW/ EXPECTED DURING THE MID TO LATE AFTERNOON...PRIMARILY EAST
OF HWY 1 AND SOUTH OF HWY 64 (SANDHILL/SE COASTAL PLAIN) WHERE THE
SEABREEZE PASSAGE WILL OCCUR THE EARLIEST...THOUGH EVEN IN THOSE
AREAS DIURNAL HEATING MAY BE SUFFICIENT FOR TEMPS TO REACH THE UPPER
80S. WITH THE ABOVE IN MIND...WILL INDICATE HIGHS IN THE MID/UPPER
80S...WARMEST IN VICINITY OF HWY 1. EXPECT LOWS TONIGHT SLIGHTLY
WARMER THAN LAST NIGHT DUE TO INCREASED BOUNDARY LAYER MOISTURE...
IN THE MID/UPPER 60S.
CONVECTION:
WEAK BUT PERSISTENT SOUTHERLY RETURN FLOW WILL ADVECT AN
INCREASINGLY MOIST AIRMASS FROM THE ATLANTIC INTO CENTRAL NC...
CHARACTERIZED BY SFC DEWPOINTS IN THE MID/UPPER 60S...H925 DEWPOINTS
OF 13-15C AND H85 DEWPOINTS OF 10-12C DURING THE MID/LATE AFTERNOON
HOURS. MID-LEVEL LAPSE RATES HAVE DECREASED IN COMPARISON TO
YESTERDAY AS THE RIDGE ALOFT WEAKENS...AND THE LATEST RAP GUIDANCE
SUGGEST H7-H5 LAPSE RATES ON THE ORDER OF 5.5-6.5 C/KM DURING PEAK
HEATING...STEEPEST IN THE EAST. IN THIS ENVIRONMENT...EXPECT
MODERATE DESTABILIZATION WITH MLCAPE VALUES OF 1000-1500 J/KG BY
PEAK HEATING AND LITTLE OR NO CIN. FORCING WILL LARGELY BE LIMITED
TO CONVERGENCE ALONG THE SEABREEZE THIS AFTERNOON...THOUGH LATEST WV
IMAGERY AND RAP DATA SUGGEST A WEAK N-S ORIENTED H3 SHEAR AXIS OVER
THE SOUTHERN APPALACHIANS SHOULD PROGRESS SLOWLY EAST INTO THE
WESTERN PIEDMONT BY 21-00Z. WITH THE ABOVE IN MIND...EXPECT A
RELATIVELY MORE ACTIVE SEABREEZE THAN YESTERDAY...WITH ISOLD SHOWERS
AND PERHAPS A FEW STORMS BY LATE AFTERNOON...PRIMARILY SOUTH OF HWY
64 ACROSS THE EASTERN SANDHILLS AND SE COASTAL PLAIN...WITH ANY
ACTIVITY WANING IN VICINITY OF THE TRIANGLE OR HWY 1 CORRIDOR BY OR
SHORTLY AFTER SUNSET. CONVECTION WILL REMAIN DISORGANIZED GIVEN
NEGLIGIBLE DEEP-LAYER SHEAR UNDER THE WEAKENING RIDGE...THOUGH
MODERATE DCAPE (~1000 J/KG) WOULD SUGGEST SOME POTENTIAL FOR
ENHANCED COLD POOLS...PRIMARILY ACROSS SCOTLAND...HOKE...
CUMBERLAND...SAMPSON AND WAYNE COUNTIES BETWEEN 20-00Z. -VINCENT
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 230 PM FRIDAY...
SATURDAY AND SATURDAY NIGHT...
THOUGH THE UPPER LEVEL RIDGE WILL CONTINUE TO WEAKEN IN COMPARISON
TO PREVIOUS DAYS...RIDGING ALOFT WILL REMAIN IN PLACE OVER THE
CAROLINAS AS THE SLOW MOVING UPPER LEVEL TROUGH CURRENTLY OVER THE
CENTRAL PLAINS PROGRESSES EAST INTO THE TN/OH RIVER VALLEYS.
LOW-LEVEL MOISTURE AND PWAT VALUES ARE PROGGED TO FURTHER INCREASE
ACROSS CENTRAL NC ON SATURDAY...THOUGH MID-LEVEL LAPSE RATES WILL BE
SIMILAR OR SLIGHTLY WEAKER THAN TODAY AT 5.5-6.0 C/KM. DIURNAL
DESTABILIZATION SAT AFTERNOON SHOULD ALSO BE SIMILAR TO TODAY...
WITH ~1000 J/KG OF MLCAPE. FORCING WILL ONCE AGAIN BE LIMITED TO
WEAK LOW-LEVEL CONVERGENCE ALONG THE SEABREEZE...THOUGH INCREASING
W/SW FLOW ALOFT ACROSS WESTERN PORTIONS OF THE STATE MAY ALLOW FOR
SOME EASTWARD PROPAGATION OF ISOLD CONVECTION THAT DEVELOPS IN
ASSOC/W DIFFERENTIAL HEATING OVER THE HIGHER TERRAIN IN WESTERN NC.
WITH THIS IN MIND...WILL KEEP A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS IN THE S/SE AND WILL INTRODUCE A SLIGHT CHANCE IN THE
FAR WESTERN PIEDMONT AS WELL. EXPECT TEMPS SIMILAR TO PREVIOUS DAYS
WITH HIGHS IN THE UPPER 80S AND LOWS IN THE UPPER 60S...SLIGHTLY
WARMER THAN TONIGHT GIVEN A FURTHER INCREASE IN BOUNDARY LAYER
MOISTURE. -VINCENT
SUNDAY AND SUNDAY NIGHT...THE MID/UPPER LEVEL TROUGH THAT HAS WET
DOWN THE MIDWEST RECENTLY IS FORECAST TO FINALLY NUDGE EAST TOWARD
THE OHIO VALLEY AND CENTRAL APPALACHIANS SUNDAY AND SUNDAY NIGHT.
THE RIDGE OVER OUR REGION WILL BREAK DOWN AND SHIFT EAST ALLOWING
THE SURFACE HIGH PRESSURE TO MOVE OFFSHORE AS WELL. DEEP MOISTURE
(PRECIPITABLE WATER VALUES 150 TO 200 PERCENT OF NORMAL) FROM THE
GULF OF MEXICO IS FORECAST TO CONTINUE FEEDING NORTHWARD AHEAD OF
THE EASTWARD MOVING COLD FRONT THAT SHOULD BE APPROACHING THE
WESTERN SLOPES OF THE APPALACHIANS BY LATE SUNDAY. SEVERAL LINES OF
CONVECTION SHOULD BE ONGOING SUNDAY OVER EASTERN TN/KY... SPREADING
INTO THE MOUNTAINS OF NC/VA DURING THE AFTERNOON. SINCE MODELS
INDICATE THE BEST MID LEVEL HEIGHT FALLS TO OCCUR TO OUR WEST AND
NORTH INTO SUNDAY EVENING... MUCH OF THE DEEP CONVECTION WILL REMAIN
JUST TO OUR WEST AND NORTH UNTIL LATE AFTERNOON. HOWEVER...
SCATTERED DIURNALLY/TERRAIN DRIVEN THUNDERSTORMS ARE FAVORED ALONG
THE BLUE RIDGE DURING PEAK HEATING... POSSIBLY SPREADING OUT INTO
THE NW PIEDMONT DURING THE LATE AFTERNOON. WE WILL MAINTAIN THE
CHANCE POP FOR THE WINSTON-SALEM AND GREENSBORO AREAS SUNDAY
AFTERNOON. ELSEWHERE... PARTLY SUNNY SKIES AND CONTINUED WARM AND
HUMID. HIGHS 85-90.
BY SUNDAY EVENING AND OVERNIGHT...A LINE OF DEEP CONVECTION IS
SUPPORTED TO AFFECT PORTIONS OF OUR WESTERN AND NORTHERN PIEDMONT
DURING THE EVENING INTO THE OVERNIGHT HOURS. LOCALLY HEAVY RAIN IS
EXPECTED WITH THE PW`S FORECAST TO REACH 150-200 PERCENT OF NORMAL
AND SURFACE DEW POINTS NEARING 70. THIS ACTIVITY MAY CONTINUE TO
ADVANCE SLOWLY EASTWARD THROUGH THE PIEDMONT OVERNIGHT... WITH A
CHANCE OF THE ACTIVITY SPREADING INTO THE SANDHILLS AND WESTERN
COASTAL PLAIN WELL AFTER MIDNIGHT. WE HAVE LIKELY POP IN THE WEST
AND NORTH... WITH CHANCE POP EAST AND SOUTH OF THAT AREA OVERNIGHT.
A SSW LOW LEVEL FLOW OF 10-15 MPH WILL KEEP TEMPERATURES IN THE
LOWER TO MID 70S EXCEPT UPPER 60S IN THE RAIN COOLED NW PIEDMONT BY
12Z/MON. THE SEVERE THREAT APPEARS MARGINAL FOR NOW... WITH THE MAIN
DYNAMICS WELL TO THE NW. HOWEVER... LOCALLY HEAVY RAIN WITH SLOW
MOVING AND TRAINING OF STORMS WILL BE POSSIBLE IN THE NW.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 210 PM FRIDAY...
AT LEAST SOME CONVECTION SHOULD BE ONGOING IN A WEAKENED STATE AT
DAYBREAK MONDAY. IT IS TOO EARLY TO TELL HOW FAR EAST THE PREVIOUS
NIGHTS CONVECTION WILL MAKE IT... BUT CONVECTIVE OUTFLOW BOUNDARIES
SHOULD PLAY A CRITICAL ROLE IN THE CONVECTIVE EVOLUTION MONDAY. THE
MAIN COLD FRONT IS FORECAST TO BE ALONG THE EASTERN SLOPES OF THE
BLUE RIDGE AT 12Z... THEN SLOWLY PUSH ESE THROUGH CENTRAL NORTH
CAROLINA MONDAY AFTERNOON AND EVENING. THERE MAY BE SEVERAL BANDS OF
CONVECTION THAT DEVELOP AND AFFECT THE REGION MONDAY. THE FIRST WITH
THE RESIDUAL OUTFLOWS AND THE NEXT ALONG OR AHEAD OF THE ACTUAL COLD
FRONT. WE WILL MAINTAIN THE LIKELY POP IN A BROAD BRUSH FASHION
MONDAY... THEN CONTINUE THE TREND OF TAPERING POP FROM THE NW MONDAY
EVENING AND NIGHT. HOWEVER... DUE TO THE EXPECTED SLOW MOVEMENT OF
THE COLD FRONT (SHOULD BE NEAR THE COAST BY 12Z TUESDAY)... LOCALLY
HEAVY RAIN CAN FOCUS/OCCUR OVER THE REGION THROUGH 12Z/TUE). THE FAR
NW ZONES SHOULD (BEGIN/END) FIRST WITH THIS HEAVY RAIN THREATS.
COOLER CONDITIONS WILL PREVAIL DUE TO THE RAIN/CLOUDS MONDAY... THEN
THE CAA WITH THE NE LOW LEVEL FLOW BEGINNING TUESDAY. INDICATIONS
ARE THAT CLOUDINESS AND THE THREAT OF RAIN MAY CONTINUE TUESDAY AS A
SECONDARY WAVE MAY FORM ALONG THE FRONT OVER COASTAL SC. WE WILL
KEEP AT LEAST SOME POP CHANCES IN THE EAST AND SOUTH TUESDAY. LOWS
60-68. HIGHS TUESDAY 75-82.
WEDNESDAY THROUGH FRIDAY... SLIGHTLY DRIER MID LEVELS... ASSOCIATED
WITH MID LEVEL RIDGING AND A MODERATELY STRONG (1026+ MB) SURFACE
HIGH PRESSURE EXTENDING FROM PA/NY INTO NC/SC WED-THU... IS
INDICATED. HOWEVER... THE NE BECOMING E LOW LEVEL FLOW SUGGESTS LATE
NIGHT AND MORNING CLOUDINESS BOTH DAYS WED-THU. LOWS 57-64. HIGHS
78-83.
BY FRIDAY... ANOTHER APPROACHING MID/UPPER LEVEL TROUGH FROM THE
CENTRAL U.S. SHOULD BEGIN TO AFFECT THE REGION. HOWEVER... WE WILL
MAINTAIN SLIGHT CHANCES FOR NOW ON DAY 7. IN GENERAL... VARIABLY
CLOUDY WITH A SE FLOW WILL CONTINUE MILD DAYS INTO FRIDAY. LOWS IN
THE 60S. HIGHS FRIDAY IN THE LOWER TO MID 80S.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 1220 PM FRIDAY...
24-HR TAF PERIOD:
VFR CONDITIONS WITH CEILINGS BETWEEN 4000-5000 FT AGL WILL PREVAIL
IN MOST AREAS THROUGH THIS EVENING...ASIDE FROM A CHANCE OF ISOLD
SHOWERS AND STORMS BETWEEN 20-00Z...PRIMARILY AT THE FAY TERMINAL...
THOUGH POSSIBLY AS FAR NORTH AS THE RDU/RWI TERMINALS PRIOR TO
DISSIPATING. OVERNIGHT...EXPECT A GOOD POTENTIAL FOR IFR/LIFR
STRATUS OR FOG AT ALL TERMINALS BETWEEN 07-13Z SAT...WITH ANY
FOG/STRATUS LIFTING TO VFR BY MID SAT MORNING. VFR CONDITIONS WITH
CEILINGS 4000-5000 FT AGL ARE EXPECTED DURING THE DAY SATURDAY.
LOOKING AHEAD:
MORE WIDESPREAD SHOWERS AND THUNDERSTORMS ARE ANTICIPATED ALONG AND
AHEAD OF A COLD FRONT PROGRESSING SLOWLY EAST THROUGH CENTRAL NC SUN
NIGHT AND MONDAY...BEGINNING IN THE WESTERN PIEDMONT (INT/GSO
TERMINALS) LATE SUNDAY AFT/EVE...EVENTUALLY ENDING FROM WEST TO EAST
LATE MON INTO MON NIGHT. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...PWB
NEAR TERM...VINCENT
SHORT TERM...VINCENT/PWB
LONG TERM...PWB
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
210 PM EDT FRI MAY 31 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN SOLIDLY OVER THE REGION THROUGH
SATURDAY... THEN SHIFT OFFSHORE SUNDAY. A COLD FRONT WILL SLOWLY
APPROACH FROM THE WEST SUNDAY...THEN CROSS THE REGION MONDAY AND
MONDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1130 AM FRIDAY...
OVERVIEW:
AN UPPER LEVEL RIDGE CENTERED ALONG THE SOUTHEAST AND MID-ATLANTIC
COAST WILL FURTHER WEAKEN THROUGH TONIGHT AS AN UPPER LEVEL LOW
CENTERED OVER THE NORTHERN PLAINS MOVES SLOWLY EAST INTO THE
NORTHERN MS RIVER VALLEY. A SFC-H85 RIDGE WILL PERSIST OFFSHORE OF
THE CAROLINAS...WITH AN INCREASINGLY MOIST SOUTHERLY RETURN FLOW
ACROSS THE REGION.
TEMPERATURES:
HIGHS TODAY APPEAR VERY SIMILAR TO THE PREVIOUS FEW DAYS GIVEN
LITTLE CHANGE IN THICKNESSES AND A VERY SIMILAR (ALBEIT INCREASINGLY
MOIST) AIRMASS. THE MAIN FACTORS W/REGARD TO HIGH TEMPS ARE APT TO
BE THE SEABREEZE APPROACHING FROM THE S/SE AND ISOLD CONVECTION
/OUTFLOW/ EXPECTED DURING THE MID TO LATE AFTERNOON...PRIMARILY EAST
OF HWY 1 AND SOUTH OF HWY 64 (SANDHILL/SE COASTAL PLAIN) WHERE THE
SEABREEZE PASSAGE WILL OCCUR THE EARLIEST...THOUGH EVEN IN THOSE
AREAS DIURNAL HEATING MAY BE SUFFICIENT FOR TEMPS TO REACH THE UPPER
80S. WITH THE ABOVE IN MIND...WILL INDICATE HIGHS IN THE MID/UPPER
80S...WARMEST IN VICINITY OF HWY 1. EXPECT LOWS TONIGHT SLIGHTLY
WARMER THAN LAST NIGHT DUE TO INCREASED BOUNDARY LAYER MOISTURE...
IN THE MID/UPPER 60S.
CONVECTION:
WEAK BUT PERSISTENT SOUTHERLY RETURN FLOW WILL ADVECT AN
INCREASINGLY MOIST AIRMASS FROM THE ATLANTIC INTO CENTRAL NC...
CHARACTERIZED BY SFC DEWPOINTS IN THE MID/UPPER 60S...H925 DEWPOINTS
OF 13-15C AND H85 DEWPOINTS OF 10-12C DURING THE MID/LATE AFTERNOON
HOURS. MID-LEVEL LAPSE RATES HAVE DECREASED IN COMPARISON TO
YESTERDAY AS THE RIDGE ALOFT WEAKENS...AND THE LATEST RAP GUIDANCE
SUGGEST H7-H5 LAPSE RATES ON THE ORDER OF 5.5-6.5 C/KM DURING PEAK
HEATING...STEEPEST IN THE EAST. IN THIS ENVIRONMENT...EXPECT
MODERATE DESTABILIZATION WITH MLCAPE VALUES OF 1000-1500 J/KG BY
PEAK HEATING AND LITTLE OR NO CIN. FORCING WILL LARGELY BE LIMITED
TO CONVERGENCE ALONG THE SEABREEZE THIS AFTERNOON...THOUGH LATEST WV
IMAGERY AND RAP DATA SUGGEST A WEAK N-S ORIENTED H3 SHEAR AXIS OVER
THE SOUTHERN APPALACHIANS SHOULD PROGRESS SLOWLY EAST INTO THE
WESTERN PIEDMONT BY 21-00Z. WITH THE ABOVE IN MIND...EXPECT A MORE
ACTIVE SEABREEZE THAN YESTERDAY...WITH ISOLD TO SCT SHOWERS AND
STORMS BETWEEN BY MID/LATE AFTERNOON...PRIMARILY SOUTH OF HWY 64
ACROSS THE EASTERN SANDHILLS AND SE COASTAL PLAIN...WITH ACTIVITY
WANING IN VICINITY OF THE TRIANGLE OR HWY 1 CORRIDOR BY OR SHORTLY
AFTER SUNSET. CONVECTION WILL REMAIN DISORGANIZED GIVEN NEGLIGIBLE
DEEP-LAYER SHEAR UNDER THE WEAKENING RIDGE...THOUGH MODERATE DCAPE
(~1000 J/KG) WOULD SUGGEST SOME POTENTIAL FOR ENHANCED COLD POOLS
AND PERHAPS AN ISOLD DOWNBURST...PRIMARILY ACROSS SCOTLAND...HOKE...
CUMBERLAND...SAMPSON AND WAYNE COUNTIES BETWEEN 19-23Z. -VINCENT
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 210 PM FRIDAY...
SATURDAY AND SATURDAY NIGHT...
SUNDAY AND SUNDAY NIGHT... THE MID/UPPER LEVEL TROUGH THAT HAS WET
DOWN THE MIDWEST RECENTLY IS FORECAST TO FINALLY NUDGE EAST TOWARD
THE OHIO VALLEY AND CENTRAL APPALACHIANS SUNDAY AND SUNDAY NIGHT.
THE RIDGE OVER OUR REGION WILL BREAK DOWN AND SHIFT EAST ALLOWING
THE SURFACE HIGH PRESSURE TO MOVE OFFSHORE AS WELL. DEEP MOISTURE
(PRECIPITABLE WATER VALUES 150 TO 200 PERCENT OF NORMAL) FROM THE
GULF OF MEXICO IS FORECAST TO CONTINUE FEEDING NORTHWARD AHEAD OF
THE EASTWARD MOVING COLD FRONT THAT SHOULD BE APPROACHING THE
WESTERN SLOPES OF THE APPALACHIANS BY LATE SUNDAY. SEVERAL LINES OF
CONVECTION SHOULD BE ONGOING SUNDAY OVER EASTERN TN/KY... SPREADING
INTO THE MOUNTAINS OF NC/VA DURING THE AFTERNOON. SINCE MODELS
INDICATE THE BEST MID LEVEL HEIGHT FALLS TO OCCUR TO OUR WEST AND
NORTH INTO SUNDAY EVENING... MUCH OF THE DEEP CONVECTION WILL REMAIN
JUST TO OUR WEST AND NORTH UNTIL LATE AFTERNOON. HOWEVER...
SCATTERED DIURNALLY/TERRAIN DRIVEN THUNDERSTORMS ARE FAVORED ALONG
THE BLUE RIDGE DURING PEAK HEATING... POSSIBLY SPREADING OUT INTO
THE NW PIEDMONT DURING THE LATE AFTERNOON. WE WILL MAINTAIN THE
CHANCE POP FOR THE WINSTON-SALEM AND GREENSBORO AREAS SUNDAY
AFTERNOON. ELSEWHERE... PARTLY SUNNY SKIES AND CONTINUED WARM AND
HUMID. HIGHS 85-90.
BY SUNDAY EVENING AND OVERNIGHT... A LINE OF DEEP CONVECTION IS
SUPPORTED TO AFFECT PORTIONS OF OUR WESTERN AND NORTHERN PIEDMONT
DURING THE EVENING INTO THE OVERNIGHT HOURS. LOCALLY HEAVY RAIN IS
EXPECTED WITH THE PW`S FORECAST TO REACH 150-200 PERCENT OF NORMAL
AND SURFACE DEW POINTS NEARING 70. THIS ACTIVITY MAY CONTINUE TO
ADVANCE SLOWLY EASTWARD THROUGH THE PIEDMONT OVERNIGHT... WITH A
CHANCE OF THE ACTIVITY SPREADING INTO THE SANDHILLS AND WESTERN
COASTAL PLAIN WELL AFTER MIDNIGHT. WE HAVE LIKELY POP IN THE WEST
AND NORTH... WITH CHANCE POP EAST AND SOUTH OF THAT AREA OVERNIGHT.
A SSW LOW LEVEL FLOW OF 10-15 MPH WILL KEEP TEMPERATURES IN THE
LOWER TO MID 70S EXCEPT UPPER 60S IN THE RAIN COOLED NW PIEDMONT BY
12Z/MON. THE SEVERE THREAT APPEARS MARGINAL FOR NOW... WITH THE MAIN
DYNAMICS WELL TO THE NW. HOWEVER... LOCALLY HEAVY RAIN WITH SLOW
MOVING AND TRAINING OF STORMS WILL BE POSSIBLE IN THE NW.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 210 PM FRIDAY...
AT LEAST SOME CONVECTION SHOULD BE ONGOING IN A WEAKENED STATE AT
DAYBREAK MONDAY. IT IS TOO EARLY TO TELL HOW FAR EAST THE PREVIOUS
NIGHTS CONVECTION WILL MAKE IT... BUT CONVECTIVE OUTFLOW BOUNDARIES
SHOULD PLAY A CRITICAL ROLE IN THE CONVECTIVE EVOLUTION MONDAY. THE
MAIN COLD FRONT IS FORECAST TO BE ALONG THE EASTERN SLOPES OF THE
BLUE RIDGE AT 12Z... THEN SLOWLY PUSH ESE THROUGH CENTRAL NORTH
CAROLINA MONDAY AFTERNOON AND EVENING. THERE MAY BE SEVERAL BANDS OF
CONVECTION THAT DEVELOP AND AFFECT THE REGION MONDAY. THE FIRST WITH
THE RESIDUAL OUTFLOWS AND THE NEXT ALONG OR AHEAD OF THE ACTUAL COLD
FRONT. WE WILL MAINTAIN THE LIKELY POP IN A BROAD BRUSH FASHION
MONDAY... THEN CONTINUE THE TREND OF TAPERING POP FROM THE NW MONDAY
EVENING AND NIGHT. HOWEVER... DUE TO THE EXPECTED SLOW MOVEMENT OF
THE COLD FRONT (SHOULD BE NEAR THE COAST BY 12Z TUESDAY)... LOCALLY
HEAVY RAIN CAN FOCUS/OCCUR OVER THE REGION THROUGH 12Z/TUE). THE FAR
NW ZONES SHOULD (BEGIN/END) FIRST WITH THIS HEAVY RAIN THREATS.
COOLER CONDITIONS WILL PREVAIL DUE TO THE RAIN/CLOUDS MONDAY... THEN
THE CAA WITH THE NE LOW LEVEL FLOW BEGINNING TUESDAY. INDICATIONS
ARE THAT CLOUDINESS AND THE THREAT OF RAIN MAY CONTINUE TUESDAY AS A
SECONDARY WAVE MAY FORM ALONG THE FRONT OVER COASTAL SC. WE WILL
KEEP AT LEAST SOME POP CHANCES IN THE EAST AND SOUTH TUESDAY. LOWS
60-68. HIGHS TUESDAY 75-82.
WEDNESDAY THROUGH FRIDAY... SLIGHTLY DRIER MID LEVELS... ASSOCIATED
WITH MID LEVEL RIDGING AND A MODERATELY STRONG (1026+ MB) SURFACE
HIGH PRESSURE EXTENDING FROM PA/NY INTO NC/SC WED-THU... IS
INDICATED. HOWEVER... THE NE BECOMING E LOW LEVEL FLOW SUGGESTS LATE
NIGHT AND MORNING CLOUDINESS BOTH DAYS WED-THU. LOWS 57-64. HIGHS
78-83.
BY FRIDAY... ANOTHER APPROACHING MID/UPPER LEVEL TROUGH FROM THE
CENTRAL U.S. SHOULD BEGIN TO AFFECT THE REGION. HOWEVER... WE WILL
MAINTAIN SLIGHT CHANCES FOR NOW ON DAY 7. IN GENERAL... VARIABLY
CLOUDY WITH A SE FLOW WILL CONTINUE MILD DAYS INTO FRIDAY. LOWS IN
THE 60S. HIGHS FRIDAY IN THE LOWER TO MID 80S.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 1220 PM FRIDAY...
24-HR TAF PERIOD:
VFR CONDITIONS WITH CEILINGS BETWEEN 4000-5000 FT AGL WILL PREVAIL
IN MOST AREAS THROUGH THIS EVENING...ASIDE FROM A CHANCE OF ISOLD
SHOWERS AND STORMS BETWEEN 20-00Z...PRIMARILY AT THE FAY TERMINAL...
THOUGH POSSIBLY AS FAR NORTH AS THE RDU/RWI TERMINALS PRIOR TO
DISSIPATING. OVERNIGHT...EXPECT A GOOD POTENTIAL FOR IFR/LIFR
STRATUS OR FOG AT ALL TERMINALS BETWEEN 07-13Z SAT...WITH ANY
FOG/STRATUS LIFTING TO VFR BY MID SAT MORNING. VFR CONDITIONS WITH
CEILINGS 4000-5000 FT AGL ARE EXPECTED DURING THE DAY SATURDAY.
LOOKING AHEAD:
MORE WIDESPREAD SHOWERS AND THUNDERSTORMS ARE ANTICIPATED ALONG AND
AHEAD OF A COLD FRONT PROGRESSING SLOWLY EAST THROUGH CENTRAL NC SUN
NIGHT AND MONDAY...BEGINNING IN THE WESTERN PIEDMONT (INT/GSO
TERMINALS) LATE SUNDAY AFT/EVE...EVENTUALLY ENDING FROM WEST TO EAST
LATE MON INTO MON NIGHT. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...PWB/V
NEAR TERM...V
SHORT TERM...V/PWB
LONG TERM...PWB
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
116 PM EDT FRI MAY 31 2013
.SYNOPSIS...
BERMUDA HIGH PRESSURE WILL CONTINUE ACROSS THE CAROLINAS THROUGH THE
WEEKEND. A COLD FRONT WILL SLOWLY MOVE THROUGH THE AREA EARLY NEXT
WEEK...BRINGING THE HIGHEST POTENTIAL FOR SHOWERS AND THUNDERSTORMS
MONDAY AND TUESDAY. HIGH PRESSURE WILL SLOWLY BUILD SOUTHWARD AND
INTO THE AREA DURING THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 130 PM FRIDAY...SHOWER/T-STORM ACTIVITY IS CENTERED ALONG TWO
PORTIONS OF THE SEABREEZE BOUNDARY: CENTRAL HORRY COUNTY AND THE
CAPE FEAR RIVER JUST NW OF WILMINGTON. THIS ACTIVITY SHOULD MAINTAIN
ITSELF OR PERHAPS WEAKEN SLIGHTLY AS IT MOVES NORTHWARD THROUGH THE
NEXT FEW HOURS. ISOLATED SHOWERS WILL PROBABLY DEVELOP BACK ACROSS
THE PEE DEE REGION AS WELL. SMALL DOWNWARD ADJUSTMENTS TO
TEMPERATURES HAVE BEEN MADE NEAR THE COAST WHERE CLOUDINESS AND
SHOWERS HAVE HELD TEMPERATURES DOWN. PREVIOUS DISCUSSION FROM 1130
AM FOLLOWS...
JUST A QUICK NEAR-TERM UPDATE TO INCREASE POPS ALONG AND WEST OF THE
SEABREEZE BOUNDARY. CURRENT RADAR LOOKS A LITTLE MORE ACTIVE THAN I
HAD ANTICIPATED WITH EXCELLENT MOISTURE POOLING ALONG THE BOUNDARY
WITHIN THE REGION OF STEEP LOW LEVEL LAPSE RATES. NO OTHER
SIGNIFICANT CHANGES. PREVIOUS DISCUSSION FROM 1030 AM FOLLOWS...
BERMUDA HIGH PRESSURE EXTENDS WESTWARD INTO THE CAROLINAS AGAIN
TODAY. THIS MEANS A CONTINUATION OF SEASONABLY WARM AND MOIST
ONSHORE WINDS. THE MOISTURE CONTENT OF THIS AIRMASS HAS GROWN OVER
THE PAST COUPLE OF DAYS...AND THIS COULD BE TERMED A MARITIME
TROPICAL AIRMASS WITH SURFACE DEWPOINTS AROUND 70 DEGREES F AND
PRECIPITABLE WATER VALUES CLIMBING TO 1.4 INCHES. THE PRECIPITABLE
WATER WOULD BE HIGHER IF IT WEREN`T FOR A CONSIDERABLE LAYER OF DRY
AIR LURKING AT AND ABOVE 700 MB WHERE DEWPOINT DEPRESSIONS ARE IN
EXCESS OF 30 DEGREES F.
THERMALLY THERE IS ONLY A HINT OF A SUBSIDENCE INVERSION AROUND 700
MB/10000 FT AGL TODAY. LAPSE RATES BELOW THIS LEVEL ARE STEEP ENOUGH
TO ENSURE WE GET LOTS OF TOWERING CUMULUS TODAY WITH ISOLATED
SHOWERS ALONG AND WEST OF THE SEABREEZE BOUNDARY. A FEW SHOWERS MAY
BREAK THROUGH THIS WEAK CONVECTIVE CAP AND BECOME THUNDERSTORMS THIS
AFTERNOON...BUT ALL THE DRY AIR ALOFT SHOULD MIX INTO THE UPDRAFTS
AND WEAKEN THESE STORMS IN SHORT ORDER. COVERAGE OF SHOWERS/STORMS
INLAND FROM THE COAST SHOULD BE 20-25 PERCENT THIS TODAY.
HIGH TEMPERATURES WILL END UP VERY CLOSE TO YESTERDAY`S READINGS:
UPPER 80S INLAND WITH LOWER TO MID 80S CLOSER TO THE COAST. THE
BEACHES WILL TOP OUT AROUND 80 WITH A SLIGHTLY COOLER MARINE AIRMASS
PUSHING ONSHORE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 245 AM FRIDAY...MID LEVEL HEIGHTS WILL SLOWLY DECREASE THROUGH
THE PERIOD WITH MOISTURE PROFILES FLUCTUATING SOMEWHAT. BERMUDA HIGH
PRESSURE CONTINUE TO BE THE MAIN FIXTURE AT THE SURFACE. MOISTURE
PROFILES ARE ACTUALLY A LITTLE HIGHER SATURDAY AND I HAVE INCLUDED
LOW CHANCE POPS FOR MOST INLAND AREAS FOR THE AFTERNOON HOURS.
SUNDAY SHOULD BE MOSTLY DRY AS PRECIPITABLE WATER VALUES ACTUALLY
DROP DURING THE DAY WHEN COMPARED TO SATURDAY. CONTINUED TO TREND
POPS SLOWLY UPWARD SUNDAY NIGHT INTO MONDAY MORNING VIA THE LONG
ADVERTISED TROUGH AND ASSOCIATED COLD FRONT MOVING CLOSER. NUMERICAL
GUIDANCE HAS WARMED SLIGHTLY WITH REGARDS TO TEMPERATURES AS HAS THE
OFFICIAL FORECAST.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 245 AM FRIDAY...THE ECMWF ENSEMBLE MEAN CONTINUES TO BE THE
FAVORED MODEL OF WPC AND THIS WARRANTS ONLY COSMETIC CHANGES TO THE
EXTENDED FORECAST. OVERALL THE AMPLITUDE HAS DECREASED A BIT BUT
STILL EXPECT THE HIGHEST POPS MONDAY AND MONDAY NIGHT AS THE MID AND
LOW LEVEL FORCING IS COUPLED. RESIDUAL LOWER POPS ARE NOW ADVERTISED
IN THE DAYS BEYOND MONDAY AND THIS SEEMS REASONABLE GIVING THE TREND
TOWARD LOWER AMPLITUDE LEADING TO LOWER CONFIDENCE THE FRONT WILL
CLEAR THE AREA.
&&
.AVIATION /12Z FRIDAY THROUGH WEDNESDAY/...
AS OF 18Z...RADAR IMAGERY SHOWS SCATTERED SHOWERS/T-STORMS
DEVELOPING ALONG THE SEA BREEZE BOUNDARY THIS AFTN. HAVE INCLUDED
VCSH FOR KFLO/KLBT AS LATEST HRRR RUNS SHOW MORE SHOWERS DEVELOPING
INLAND LATER TODAY. OTHERWISE...VFR SHOULD PREVAIL WITH SCT/BKN CU
AND SSE WINDS AOB 10 KTS. MOSTLY CLEAR CONDITIONS TONIGHT AND PLENTY
OF LOW-LEVEL MOISTURE INDICATES FOG/STRATUS IS AGAIN LIKELY AFTER
06Z. SREF PROBS AND GUIDANCE SUGGEST IFR CIGS/VSBYS WILL BE MORE
WIDESPREAD INLAND...SIMILAR TO WHAT OCCURRED THIS MORNING. TEMPO IFR
IS ALSO QUITE POSSIBLE ALONG THE COAST...MOST LIKELY IN THE 09-12Z
RANGE. FOG/STRATUS SHOULD LIFT SOON AFTER 12Z SATURDAY.
EXTENDED OUTLOOK...EARLY MORNING MVFR/IFR CIGS/VSBYS POSSIBLE
THROUGH SUNDAY. SLIGHT CHANCE OF SHOWERS INLAND ON SUNDAY...WITH
BETTER PCPN CHANCES ACROSS THE CWA MONDAY AND TUESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 130 PM FRIDAY...A FAIRLY LARGE AREA OF SHOWERS 10-30 MILES
INLAND FROM THE COAST HAS KEPT INLAND TEMPERATURES A FEW DEGREES
COOLER THAN EXPECTED...AND THIS HAS DELAYED THE INTENSIFICATION OF
THE SEABREEZE BY A FEW HOURS. SOUTHEAST WINDS SHOULD STILL INCREASE
TO A SOLID 10-12 KNOTS WITH GUSTS TOWARD 15 KNOTS IN THE NEXT COUPLE
OF HOURS. NO OTHER SIGNIFICANT CHANGES. PREVIOUS DISCUSSION FROM
1030 AM FOLLOWS...
BERMUDA HIGH PRESSURE WELL OFFSHORE CONTINUES TO EXTEND A RIDGE AXIS
ACROSS THE CAROLINAS WITH LIGHT ONSHORE WINDS THE RESULT. MUCH LIKE
YESTERDAY...MODEST MARINE-TO-INLAND TEMPERATURE CONTRASTS WILL FUEL
A WEAK SEABREEZE WITH WIND SPEEDS NEARSHORE INCREASING TO 12-14
KNOTS. SHOWERS OUT TOWARD 40 MILES FROM SHORE AND NEW SHOWERS
DEVELOPING JUST INLAND FROM THE BEACHES SHOULD AVOID THE COASTAL
WATERS THROUGH THE DAY...WITH MAINLY SUNNY SKIES EXPECTED. SEAS
AVERAGE 2.5 TO 3 FEET ON THE BUOYS NEAR CAPE FEAR THIS
MORNING...WITH WAVE ENERGY EQUALLY SPLIT BETWEEN 6 AND 9 SECOND
PERIODS.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 245 AM FRIDAY...BERMUDA HIGH PRESSURE CIRCULATION WILL BRING
SEAS AROUND THREE FEET IN 7-8 SECOND INTERVALS. SOME ACCELERATION
AND SLIGHTLY CHOPPIER SEAS CAN BE EXPECTED EACH AFTERNOON CLOSER
TO SHORE VIA THE SEA BREEZE.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 245 AM FRIDAY...SOUTH TO SOUTHWESTERLY WINDS THROUGH MOST OF
THE PERIOD AS THE WIND SHIFT ASSOCIATED WITH THE FRONT WILL TAKE
SOME TIME TO OCCUR. BY WEDNESDAY MORNING EXPECT A WEAK NORTHEASTERLY
FLOW TO BE IN PLACE. CERTAINLY NO STRONG PUSH OF COLD AIR BEHIND THE
FRONT AND OVERALL EXPECT WINDS TO BE IN A 10-15 KNOT RANGE.
SIGNIFICANT SEAS REMAIN IN A 2-3 FOOT RANGE A SLIGHT DECREASE FROM
EARLIER FORECASTS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...BJR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1220 PM EDT FRI MAY 31 2013
.SYNOPSIS...
A COLD FRONT WILL SLOWLY APPROACH FROM THE WEST THIS WEEKEND...THEN
CROSS THE REGION SUNDAY NIGHT THROUGH MONDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1130 AM FRIDAY...
OVERVIEW:
AN UPPER LEVEL RIDGE CENTERED ALONG THE SOUTHEAST AND MID-ATLANTIC
COAST WILL FURTHER WEAKEN THROUGH TONIGHT AS AN UPPER LEVEL LOW
CENTERED OVER THE NORTHERN PLAINS MOVES SLOWLY EAST INTO THE
NORTHERN MS RIVER VALLEY. A SFC-H85 RIDGE WILL PERSIST OFFSHORE OF
THE CAROLINAS...WITH AN INCREASINGLY MOIST SOUTHERLY RETURN FLOW
ACROSS THE REGION.
TEMPERATURES:
HIGHS TODAY APPEAR VERY SIMILAR TO THE PREVIOUS FEW DAYS GIVEN
LITTLE CHANGE IN THICKNESSES AND A VERY SIMILAR (ALBEIT INCREASINGLY
MOIST) AIRMASS. THE MAIN FACTORS W/REGARD TO HIGH TEMPS ARE APT TO
BE THE SEABREEZE APPROACHING FROM THE S/SE AND ISOLD CONVECTION
/OUTFLOW/ EXPECTED DURING THE MID TO LATE AFTERNOON...PRIMARILY EAST
OF HWY 1 AND SOUTH OF HWY 64 (SANDHILL/SE COASTAL PLAIN) WHERE THE
SEABREEZE PASSAGE WILL OCCUR THE EARLIEST...THOUGH EVEN IN THOSE
AREAS DIURNAL HEATING MAY BE SUFFICIENT FOR TEMPS TO REACH THE UPPER
80S. WITH THE ABOVE IN MIND...WILL INDICATE HIGHS IN THE MID/UPPER
80S...WARMEST IN VICINITY OF HWY 1. EXPECT LOWS TONIGHT SLIGHTLY
WARMER THAN LAST NIGHT DUE TO INCREASED BOUNDARY LAYER MOISTURE...
IN THE MID/UPPER 60S.
CONVECTION:
WEAK BUT PERSISTENT SOUTHERLY RETURN FLOW WILL ADVECT AN
INCREASINGLY MOIST AIRMASS FROM THE ATLANTIC INTO CENTRAL NC...
CHARACTERIZED BY SFC DEWPOINTS IN THE MID/UPPER 60S...H925 DEWPOINTS
OF 13-15C AND H85 DEWPOINTS OF 10-12C DURING THE MID/LATE AFTERNOON
HOURS. MID-LEVEL LAPSE RATES HAVE DECREASED IN COMPARISON TO
YESTERDAY AS THE RIDGE ALOFT WEAKENS...AND THE LATEST RAP GUIDANCE
SUGGEST H7-H5 LAPSE RATES ON THE ORDER OF 5.5-6.5 C/KM DURING PEAK
HEATING...STEEPEST IN THE EAST. IN THIS ENVIRONMENT...EXPECT
MODERATE DESTABILIZATION WITH MLCAPE VALUES OF 1000-1500 J/KG BY
PEAK HEATING AND LITTLE OR NO CIN. FORCING WILL LARGELY BE LIMITED
TO CONVERGENCE ALONG THE SEABREEZE THIS AFTERNOON...THOUGH LATEST WV
IMAGERY AND RAP DATA SUGGEST A WEAK N-S ORIENTED H3 SHEAR AXIS OVER
THE SOUTHERN APPALACHIANS SHOULD PROGRESS SLOWLY EAST INTO THE
WESTERN PIEDMONT BY 21-00Z. WITH THE ABOVE IN MIND...EXPECT A MORE
ACTIVE SEABREEZE THAN YESTERDAY...WITH ISOLD TO SCT SHOWERS AND
STORMS BETWEEN BY MID/LATE AFTERNOON...PRIMARILY SOUTH OF HWY 64
ACROSS THE EASTERN SANDHILLS AND SE COASTAL PLAIN...WITH ACTIVITY
WANING IN VICINITY OF THE TRIANGLE OR HWY 1 CORRIDOR BY OR SHORTLY
AFTER SUNSET. CONVECTION WILL REMAIN DISORGANIZED GIVEN NEGLIGIBLE
DEEP-LAYER SHEAR UNDER THE WEAKENING RIDGE...THOUGH MODERATE DCAPE
(~1000 J/KG) WOULD SUGGEST SOME POTENTIAL FOR ENHANCED COLD POOLS
AND PERHAPS AN ISOLD DOWNBURST...PRIMARILY ACROSS SCOTLAND...HOKE...
CUMBERLAND...SAMPSON AND WAYNE COUNTIES BETWEEN 19-23Z. -VINCENT
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...
SATURDAY/SATURDAY NIGHT...
WHILE HEIGHTS ALOFT BEGIN TO FALL EVER SO SLIGHTLY AHEAD OF THE
UPPER TROUGH MOVING INTO THE MID WEST STATES...THE MID-LEVEL RIDGE
OVER THE WESTERN ATLANTIC WILL REMAIN DOMINATE AS IT EXTENDS ACROSS
CENTRAL NC SATURDAY. THUS...EXPECT ANOTHER DAY OF AFTERNOON HIGHS
IN THE MID TO UPPER 80S AND ISOLATED SHOWERS POSSIBLE ALONG THE
SEABREEZE. MOISTURE TRANSPORT WILL BEGIN TO INCREASE ACROSS WESTERN
NC SATURDAY NIGHT AS THE MID-LEVEL RIDGE EASES EASTWARD. EXPECT A
FEW SHOWERS MAY BE POSSIBLE WEST OF THE YADKIN-RIVER...BUT WILL PLAN
TO KEEP THE RAH CWA DRY THROUGH 12Z...AWAITING THE ARRIVAL OF
STRONGER LOW-LEVEL FLOW AND DIURNAL HEATING. -SMITH
FOR SUNDAY/SUNDAY NIGHT: THE SLIGHTLY WEAKENING MID LEVEL TROUGH
AXIS APPROACHES OUR AREA FROM THE WEST... WITH MODELS DEPICTING A
WEAK PERTURBATION RIDING TO THE NORTHEAST UP THROUGH THE WRN/CENTRAL
CAROLINAS LATE SUNDAY INTO SUNDAY NIGHT... AS UPPER DIVERGENCE
INCREASES IN THE RIGHT ENTRANCE REGION OF A ST LAWRENCE VALLEY JET.
AS THE COLD FRONT APPROACHES FROM THE WEST... HIGH PRECIP WATER
(150-200% OF NORMAL) IS EXPECTED TO SURGE NORTHEASTWARD OVER WRN NC
SUNDAY AND INTO CENTRAL NC SUNDAY EVENING/NIGHT... ACCOMPANIED BY
INCREASING LOW LEVEL MOISTURE TRANSPORT. THE 50 KT LOW LEVEL JET
RIDES TO OUR NW ALONG THE CENTRAL APPALACHIANS EARLY SUNDAY BEFORE
SHIFTING UP INTO THE CANADIAN MARITIMES... LEAVING A MUCH MORE
SUBDUED 25-30 KT LOW LEVEL SPEED MAX FROM THE NRN PIEDMONT TO
COASTAL NEW ENGLAND... SO THE DYNAMIC FORCING FOR ASCENT AS WELL AS
THE KINEMATICS WILL GENERALLY BE RAMPING DOWN WITH MINIMAL DPVA.
INSTABILITY IS MARGINAL AS WELL WITH MODELS DEPICTING BRIEF MUCAPE
OF 1000-1500 J/KG OVER THE WRN CWA LATE SUNDAY WHILE THE SREF SHOWS
VERY LOW PROBABILITIES OF MLCAPE OVER 1000 J/KG AT ANY TIME...
LIKELY DUE IN PART TO WEAK MID LEVEL LAPSE RATES LESS THAN 6 C/KM.
BUT THE INCREASE IN MOISTURE AND WHAT WEAK LIFT THERE IS STILL SEEMS
TO SUPPORT CHANCE TO LOW-END LIKELY POPS SPREADING INTO AREAS WEST
OF HIGHWAY 1 LATE AFTERNOON AND THROUGH THE NIGHT. WILL ADJUST TO
BRING POPS EASTWARD A BIT LATER TO FIT WITH THE LATEST GUIDANCE
TIMING BUT WILL RETAIN THE GENERAL FLAVOR OF THE EARLIER FORECAST.
HIGHS 83-90... A LEAN TOWARD THE WARMER GFS-BASED STATISTICAL
GUIDANCE. ABOVE-GUIDANCE LOWS OF 68-72 WITHIN A PREFRONTAL WARM AIR
ADVECTION PATTERN. -GIH
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 245 AM FRIDAY...
FOR MONDAY/MONDAY NIGHT: BEST CHANCE OF SHOWERS/STORMS STILL LOOKS
TO BE IN THIS TIME FRAME. AS A STRONG VORTEX MOVES FROM SE ONTARIO
ACROSS SRN QUEBEC... THE WEAK SOUTHERN END OF THE TRAILING MID LEVEL
TROUGH EASES EASTWARD THROUGH THE AREA... ACCOMPANIED BY THE SURFACE
FRONT AND PRECEDED BY THE MINOR LOBE OF VORTICITY WHICH TRAVERSES
CENTRAL/ERN NC. THE ASCENT WILL BE ROOTED IN THE MID-UPPER LEVELS
WITH ONLY VERY WEAK MASS CONVERGENCE NEAR THE GROUND... BUT WITH
LIFT POTENTIALLY AUGMENTED BY 1000-1500 J/KG OF MLCAPE (FROM THE GFS
AND ECMWF)... IT SHOULD BE STRONG ENOUGH WITH THE EXPECTED DEEP
MOISTURE FOR LIKELY POPS AREAWIDE MONDAY... SLOWLY DECREASING WEST
TO EAST IN THE WEST MONDAY NIGHT BUT REMAINING LIKELY IN THE EAST.
CONFIDENCE IS HIGH THAT A PERIOD OF CATEGORICAL POPS WILL BE NEEDED
ONCE WE GET CLOSER AND CAN PIN DOWN TIMING A BIT BETTER. COULD SEE
UP TO AN INCH OF STORM-TOTAL RAIN BASED ON PRECIP WATER NEARING 2.0
INCHES AND A DEEP LCL-TO-0C LAYER AROUND 4 KM. HIGHS 77-84. LOWS
FROM 62 NW TO NEAR 70 SE.
FOR TUESDAY THROUGH THURSDAY: THE MID LEVEL SHEAR AXIS IS EXPECTED
TO SHIFT OFFSHORE BY TUESDAY MORNING WITH THE SURFACE FRONT DRIFTING
EASTWARD TO THE COASTAL AREA. THE ECMWF`S TROUGH IS NOTABLY WEAKER
AND MORE BAGGY THAN THE GFS`S... AND AS A RESULT THE ECMWF IS MUCH
SLOWER WITH THE FRONT... HANGING IT BACK FARTHER WEST... MEANING
CONTINUED WARM AIR/HIGH HUMIDITY AND RAIN CHANCES OVER ALL BUT THE
NW CWA. THINK THE ECMWF MAY BE ONTO SOMETHING GIVEN THAT THE
STRONGEST MID LEVEL FLOW WITH THE EASTERN CANADA LOW WILL HOLD NORTH
OF THE MASON-DIXON LINE. WILL HOLD ONTO AT LEAST CHANCE POPS FOR
SHOWERS SOUTH AND EAST OF RALEIGH THROUGH TUESDAY... WITH MORE
CLOUDS AND HIGHER DEW POINTS IN THE MID-UPPER 60S. THE QUEBEC VORTEX
LIFTS UP ACROSS ERN CANADA WHILE A SECOND LOW CROSSES THE DAKOTAS
TUESDAY NIGHT BEFORE SETTLING OVER THE UPPER MIDWEST THROUGH
MIDWEEK. FOR TUESDAY NIGHT THROUGH THURSDAY WE SHOULD BE UNDER THE
INFLUENCE OF THE CANADIAN SURFACE HIGH NOSING IN FROM THE NORTH
BENEATH WEAK MAINLY WESTERLY MID LEVEL FLOW... YIELDING FAIR SKIES
AND GENERALLY DRY CONDITIONS. THE RETURN EASTERLY FLOW AROUND THE
SURFACE HIGH STRENGTHENS BY THURSDAY WITH INCREASING ATLANTIC
INFLOW... AND THIS MAY RESULT IN A FEW SHOWERS OVER CENTRAL NC...
BUT THE CHANCE FOR SUFFICIENTLY DEEP MOISTURE IS TOO UNCERTAIN FOR
ANYTHING BUT SLIGHT CHANCE POPS FOR NOW. THICKNESSES SUPPORT TEMPS
NEAR NORMAL SE AND BELOW NORMAL NW ON TUESDAY... DROPPING TO ABOUT A
CATEGORY BELOW NORMAL FOR WEDNESDAY AND THURSDAY. -GIH
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 1220 PM FRIDAY...
24-HR TAF PERIOD:
VFR CONDITIONS WITH CEILINGS BETWEEN 4000-5000 FT AGL WILL PREVAIL
IN MOST AREAS THROUGH THIS EVENING...ASIDE FROM A CHANCE OF ISOLD
SHOWERS AND STORMS BETWEEN 20-00Z...PRIMARILY AT THE FAY TERMINAL...
THOUGH POSSIBLY AS FAR NORTH AS THE RDU/RWI TERMINALS PRIOR TO
DISSIPATING. OVERNIGHT...EXPECT A GOOD POTENTIAL FOR IFR/LIFR
STRATUS OR FOG AT ALL TERMINALS BETWEEN 07-13Z SAT...WITH ANY
FOG/STRATUS LIFTING TO VFR BY MID SAT MORNING. VFR CONDITIONS WITH
CEILINGS 4000-5000 FT AGL ARE EXPECTED DURING THE DAY SATURDAY.
LOOKING AHEAD:
MORE WIDESPREAD SHOWERS AND THUNDERSTORMS ARE ANTICIPATED ALONG AND
AHEAD OF A COLD FRONT PROGRESSING SLOWLY EAST THROUGH CENTRAL NC SUN
NIGHT AND MONDAY...BEGINNING IN THE WESTERN PIEDMONT (INT/GSO
TERMINALS) LATE SUNDAY AFT/EVE...EVENTUALLY ENDING FROM WEST TO EAST
LATE MON INTO MON NIGHT. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...SMITH/HARTFIELD
LONG TERM...HARTFIELD
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
256 PM EDT FRI MAY 31 2013
.SYNOPSIS...
WARM SECTOR THROUGH SATURDAY NIGHT WITH CONVECTION POSSIBLE
ESPECIALLY DURING DAYTIME HEATING HOURS. COLD FRONT CROSSES
SUNDAY. COOLER AND DRIER TO START NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
18Z RADAR IMAGERY SHOWING SHOWERS AND THUNDERSTORMS CONTINUING TO
DEVELOP TO THE WEST ROUGHLY AROUND THE IN/OH BORDER AREA SOUTHWARD
INTO CENTRAL KENTUCKY. OUT AHEAD OF THAT GENERAL AREA A FEW DISCRETE
THUNDERSTORMS HAD FORMED TO THE EAST. PRIMARY CONCERNS IN THE NEAR
TERM REVOLVE AROUND THIS EVENING/S CONVECTION AS WELL AS
REDEVELOPING SHOWERS/THUNDERSTORMS TOMORROW.
THIS EVENING...TOUGH CALL ON EXACTLY HOW FAR EAST TO TAKE PRECIP
WITH A READILY-APPARENT DECAYING MCV PUSHING E/NE-WARD ACROSS NORTH
CENTRAL KY. LATEST RAP SEEMS TO HAVE SOMEWHAT OF A HANDLE ON THE
SHEAR ASSOC WITH IT...WITH NEAR 40KTS OF SHEAR DEPICTED ACROSS THE
SW OHIO AND NC KY AREAS. FURTHER EAST OVER OUR WESTERN ZONES...SHEAR
IS APPRECIABLY LOWER AND ONLY AROUND 15-20KTS. LATEST RAP RUNS ALSO
CONTINUE TO WEAKEN/SHEAR THE VORT MAX ASSOC WITH THE MCV...WITH
SHEAR VALUES ONLY CLIMBING TO AROUND 25KTS NEAR PERRY CO OH...AND
LESS POINTS EAST AND SOUTH OF THAT...BY 00Z. INSTABILITY WILL BE
DECREASING AS WELL AND BECOMING MORE ELEVATED AS USUAL...WHICH
SHOULD SPELL A DECREASING RISK OF STRONG WINDS. ALL IN ALL...DO
BELIEVE SHOWERS AND SOME THUNDERSTORMS STAND A DECENT CHANCE OF
REACHING OUR WESTERN ZONES AND PARTICULARLY THE SE OHIO ZONES. WHILE
A SEVERE THUNDERSTORM CAN/T BE COMPLETELY RULED OUT IN THOSE
LOCATIONS...CURRENT THINKING IS THAT THE BULK OF ANY SEVERE WX
REMAINS WEST.
OVERNIGHT...WILL KEEP GENERAL INHERITED FORECAST AND DRY OUT MOST
LOCATIONS BTWN 03Z-06Z. DID ELECT TO KEEP A SLIGHT CHANCE ACROSS THE
FAR NW ZONES HOWEVER...ON THE NOSE OF A 850MB JET. PREV FCST LOW
TEMPS IN THE MID/UPPER 60S LOWLANDS STILL LOOK GOOD. SLIGHTLY
STRONGER BL WINDS OVERNIGHT PROGGED AFTER 06Z SHOULD PRECLUDE
WIDESPREAD FOG FORMATION BUT THE USUAL SPOTS SUCH AS EKN WILL MOST
LIKELY SEE REDUCED VIS NEAR DAWN.
TOMORROW...INHERITED MAX TEMPS IN THE MID/UPPER 80S LOWLANDS LOOK
GOOD. PRIMARY FOCUS ON THUNDERSTORMS AND SVR THUNDERSTORM POTENTIAL.
NOT REALLY SEEING MUCH IN THE WAY OF ANY ORGANIZED LARGE-SCALE LIFT
FOR MUCH OF THE DAY WITH THE TROUGH AXIS AND SFC COLD FRONT STILL
WELL TO THE WEST. LOWERED POPS TO LOW CHANCE FOR THE MORNING HOURS
AND INTO THE EARLY AFTERNOON HOURS AS SUCH. BTWN 18Z-21Z...GOOD
DYNAMICS ARRIVE TO THE WEST OF OUR AREA...OVER IN/WEST OH SOUTHWARD
INTO CENTRAL KY. THIS AREA SHOULD SERVE FOR ORGANIZED CONVECTIVE
INITIATION BY 21Z...WITH SUPERCELLS A POSSIBILITY. THIS AREA WILL
SLOWLY PROGRESS EASTWARD...BUT RIGHT-MOVER MOTION WOULD TAKE THESE
STORMS IN AN MORE E/NE DIRECTION AROUND 30KTS. AGAIN AS WITH THIS
AFTERNOON...THE BULK OF SVR WX SHOULD REMAIN WEST BUT WITH BETTER
SHEAR OVER OUR AREA TOMORROW A BETTER LIKELIHOOD OF SVR WX OVER OUR
WESTERN ZONES EXISTS PRIMARILY LATE AFTERNOON INTO MID-EVE HOURS.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
COLD FRONT WILL PUSH EAST INTO THE CWA SUNDAY MORNING. TIMING OF THE
FRONT LOOKS TO BE A FEW HOURS SLOWER THAN PREVIOUS RUNS...BUT STILL
THINKING MUCH OF THE CWA WILL NOT SEE MUCH IN TERMS OF SEVERE DUE TO
TIMING...ALTHOUGH THE EASTERN ZONES WILL BE MORE SUSCEPTIBLE DUE TO
LATER FRONTAL PASSAGE. DECENT CAPE...GENERALLY 1500-2000
J/KG...ALONG WITH 30-40 KTS 0-6KM BULK SHEAR WILL CREATE A POTENTIAL
FOR STRONG STORMS...WITH WINDS...AND HAIL THE PRIMARY
THREATS...MAINLY ACROSS THE EAST. HOWEVER...PLENTY OF CLOUD COVER
OUT AHEAD OF THE FRONT MAY ALSO HELP TO MITIGATE THE SEVERE
THREAT...ESPECIALLY EARLY ON. SO FOR NOW...ITS A WAIT AND SEE
SCENARIO TO SEE IF ANY OF THE ABOVE MENTIONED FACTORS ARE ABLE TO
LINE UP...BUT LOOKING LIKE BULK OF SEVERE THREAT WILL BE TO THE EAST
OF THE CWA. AS OF RIGHT NOW...SPC HAS THE SLIGHT RISK TO THE EAST OF
THE CWA...WITH CWA IN GENERAL THUNDER...AND A 5 PERCENT PROB OUTLOOK
FOR SEVERE.
COLD FRONT WILL EXIT TO THE EAST OF THE CWA SUNDAY NIGHT...WITH
COOLER AND DRIER WEATHER TAKING HOLD.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
GENERALLY FOLLOWED WPC THINKING WITH SOME TWEAKS.
HIGH PRESSURE WILL DOMINATE THE REGION ON TUESDAY...WITH
TEMPERATURES NEAR NORMAL READINGS. HOWEVER...THE HIGH WILL PUSH
EAST ON WEDNESDAY...RESULTING IN SOUTHERLY WINDS AND WARMER
TEMPERATURES. THE SOUTHERLY WINDS WILL ALSO RESULT IN INCREASING
LOW-LEVEL MOISTURE AND THE CHANCES FOR SHOWERS AND STORMS...MAINLY
DIURNAL IN NATURE...WILL ALSO RETURN THROUGH THE REMAINDER OF THE
PERIOD.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
12Z FRIDAY THRU 12Z SATURDAY...
VFR FOR MOST SITES THROUGH MUCH OF THE PERIOD. PUT IN SOME RIVER
AND VALLEY FOG THAT WILL RESULT IN SOME MVFR CONDITIONS FOR THE
VALLEYS OVERNIGHT. EKN IS EXPECTED TO DROP TO IFR FOR AT LEAST A FEW HOURS
WITH CALM WINDS AND HIGHER RH IN THE SHELTERED VALLEY.
TOWARD THE END OF THE PERIOD...CIGS ARE EXPECTED TO LOWER AS PRECIP
BEGINS TO MOVE INTO SE OH AND NORTHERN WV...HOWEVER...GENERALLY
EXPECT VFR CONDITIONS TO REMAIN.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SATURDAY...
FORECAST CONFIDENCE...HIGH.
ALTERNATE SCENARIOS: SUB-VFR VIS OVERNIGHT MAY VARY IN EXPECTED
COVERAGE AND/OR INTENSITY. TIMING AND COVERAGE OF SHOWERS AND
THUNDERSTORMS MAY VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H 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 H H H H
AFTER 18Z SATURDAY...
IFR POSSIBLE IN SHOWERS AND THUNDERSTORMS SUNDAY INTO SUNDAY
NIGHT...AND POST RAIN...FOG...AND LOW CLOUDS LATE SUNDAY NIGHT
INTO MONDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JSH/50/SL
NEAR TERM...50
SHORT TERM...SL
LONG TERM...JSH
AVIATION...LS
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1234 PM CDT FRI MAY 31 2013
.UPDATE...FOR 18Z AVIATION FORECAST
&&
.AVIATION...
MESO CONVECTIVE VORTICITY CENTER ROTATING OVER WEST CENTRAL
KENTUCKY AT 17Z WILL CONTINUE TO LIFT NORTHEAST. BULK OF SHOWERS
AND ISOLATED STORMS ARE PULLING AWAY FROM MIDDLE TENNESSEE AS MCV
LIFTS NORTHEASTWARD LEAVING SUBSIDENCE BEHIND IT. AM SEEING
SCATTERED CONVECTION FIRING EAST OF INTERSTATE 65 BUT NOT
EXPECTING THIS TO AMOUNT TO MUCH. BASICALLY EXPECT AIR MASS ACROSS
MIDDLE TENNESSEE TO BEGIN DRYING OUT DURING THE AFTERNOON AND
CONTINUE THROUGH THE OVERNIGHT IN THE WAKE OF MCV.
BOYD
&&
.PREV DISCUSSION... /ISSUED 948 AM CDT FRI MAY 31 2013/
UPDATE...
LATEST RADAR AND IR SATELLITE IMAGERY DEPICTS A WEAKENING MCS
OVER WESTERN ZONES WITH SHOWERS AND STORMS DIMINISHING IN
COVERAGE AND CLOUD TOPS WARMING SIGNIFICANTLY. ALTHOUGH HRRR
INDICATES ACTIVITY WILL CONTINUE MARCHING EASTWARD THROUGH THE
CWA...APPEARS MUCH OF THE CURRENT PRECIP WILL DISSIPATE PRIOR TO
REACHING THE I-65 CORRIDOR. NEVERTHELESS...VERY MOIST AIRMASS IN
PLACE SHOWN BY THE PWAT OF 1.67 INCHES ON THE 12Z OHX SOUNDING
ALONG WITH CONTINUED DAYTIME HEATING SHOULD SPAWN ADDITIONAL
SCATTERED SHOWERS AND STORMS AHEAD OF DYING MCS LATER TODAY. HAVE
RAISED POPS ACROSS CENTRAL AND WESTERN ZONES FOR THE MORNING HOURS
BASED ON CURRENT TRENDS...AND BUMPED UP CLOUD COVER AND LOWERED
HIGH TEMPS IN THE NORTHWEST. REST OF FORECAST REMAINS UNCHANGED.
SHAMBURGER
PREV DISCUSSION... /ISSUED 831 AM CDT FRI MAY 31 2013/
AVIATION UPDATE...
GOOD ROUND OF SHOWERS AND STORMS OVER WESTERN TENNESSEE HAVE
MOVED INTO NORTHWEST TENNESSEE WITH ISOLATED RENEGADE SHOWERS
FIXING TO MOVE INTO DAVIDSON COUNTY. H-TRIPLE-R DRIVE SHOWERS AND
STORMS CURRENTLY IN WEST TENNESSEE EASTWARD AS WE GO THROUGH THE
MORNING HOURS.
INFRARED SATELLITE LOOP SHOW TOPS WARMING ACROSS WESTERN TENNESSEE
WITH LIGHTNING STRIKES DECREASING.
BOYD
PREV DISCUSSION... /ISSUED 622 AM CDT FRI MAY 31 2013/
UPDATE...FOR 12Z AVIATION DISCUSSION.
AVIATION...12Z AVIATION DISCUSSION.
UNCERTAINTIES...HOW FAR WILL MOISTURE ASSOCIATED WITH DYING MCS MAKE IT INTO
MID STATE AND ASSOCIATED SHWR/TSTMS CHANCES. WILL GO WITH VFR CEILINGS THRU
01/12Z...WITH MAIN IMPACT OF SHWRS/TSTMS ACROSS CKV FROM 31/13Z-31/18Z. QUESTION
HOW FAR EWD MCS INFLUENCES WILL EXTEND...AND THUS WILL CONTINUE WITH ONLY
VCTS REMARKS AT BOTH BNA/CSV. EXPECT SOME ERROSION OF VFR CU CEILINGS AFTER
31/18Z W TO 31/22Z E...WITH AN INCREASE IN MOISTURE AHEAD OF UPPER LEVEL
DISTURBANCE ALLOWING FOR SCT/BKN STCU/AC/CI FROM 01/07Z W TO 01/12Z E. PER SFC
PRESSURE GRADIENT...EXPECT GUST TO 20KTS POSSIBLE 31/13Z W TO 01/03Z E.
PREV DISCUSSION.../ISSUED 554 AM CDT FRI MAY 31 2013/
UPDATE...
LATEST MODELS INDICATING THAT THE DEEPER MOISTURE WILL INDEED
TRANSITION NORTHEASTWARD ACROSS OUR NORTHWESTERN COUNTIES LATER
THIS MORNING. THIS IS FURTHER CONFIRMED BY RECENT RADAR TRENDS AND
TODAY`S HRRR DATA. WILL GO AHEAD AND INCREASE POPS...PRIMARILY
ACROSS WESTERN AND NORTH CENTRAL ZONES.
PREV DISCUSSION... /ISSUED 333 AM CDT FRI MAY 31 2013/
MAIN COLD FRONTAL BOUNDARY IS STILL LOCATED WELL WEST OF TN AND
RESIDES ALONG THE CENTRAL PLAINS. MAIN FOCUS OF CONVECTION THIS
MORNING IS IN ASSOCIATION WITH A SERIES OF MCS`S FROM AR NE THROUGH
NRN IN. 850MB JET IS COMBINING WITH STRONG IMPULSES WITHIN THE SWLY
FLOW ALOFT TO KEEP THIS CONVECTION GOING OVERNIGHT. MODELS DO SHOW
AN EASTWARD MIGRATION OF THESE DYNAMICS FOR TODAY. ALTHOUGH THE
DYNAMICS WILL WEAKEN...HRRR DOES SUPPORT CONVECTION MOVING INTO OUR
NORTHWESTERN ZONES LATER THIS MORNING. CURRENTLY...CONVECTION HAS
MOVED INTO FAR WESTERN TN. THUS...POPS OF 30-50 PERCENT FOR
TODAY...GREATEST POPS WEST.
TONIGHT...COLD FRONT GETS A LITTLE CLOSER BUT AGAIN...THE BETTER MCS
COMPLEXES WILL REMAIN NW OF MIDDLE TN. MAY SEE SOME CONVECTIVE
ENCROACHMENT ON OUR FAR NW AREAS LATE TONIGHT AND WILL THUS INCLUDE
40 POPS NW...20 POPS ELSEWHERE.
ON SATURDAY...COLD FRONT WILL APPROACH THE MS RIVER BY LATE
AFTERNOON. MOISTURE AND INSTABILITY WILL BE RAMPING UP ACROSS THE
MID STATE AND POPS OF 30-60 PERCENT WILL BE ON ORDER. THE OVERALL
SYSTEM WILL BECOME MORE SFC ORIENTED AS THE MID AND UPPER JETS
REMAIN NORTH OF TN. NEVERTHELESS..FRONTAL IMPACTS WILL BE
FELT...ESPECIALLY ON SATURDAY NIGHT AND SUNDAY...WITH THE FROPA
OCCURRING ON SUNDAY.
AS FOR SEVERE CHANCES...ELEVATED CAPES WILL CONVERGE WITH FRONTAL
BASED SFC FORCING TO PROMOTE A SLIGHT RISK OF SEVERE ON SATURDAY AFT
AND EVENING...MAINLY WESTERN ZONES. THEN...AS THE FRONT MOVES
THROUGH ON SUNDAY...SEVERE WEATHER WILL BE POSSIBLE ACROSS EASTERN
ZONES DURING THE DAY. NOT REALLY SEEING MUCH OVERNIGHT SEVER WEATHER
POTENTIAL...UPPER DYNAMICS ARE LOOKING WEAKER AND 850 MB FLOW IS NOT
OVERLY IMPRESSIVE. DESCENT QPF TOTALS FOR THE SAT NT
OVERNIGHT...BUT OVERALL STORM DEINTENSIFICATION MAY BE THE RULE AS
WE LOSE THE DAYTIME HEATING AND THE ELEVATED DYNAMICS ARE NOT
OVERLY IMPRESSIVE.
AS FOR HEAVY RAINFALL POTENTIAL...LOOKS LIKE STORM TOTAL QPF OF UP
TO 2 INCHES IS POSSIBLE NW AREAS...1 TO 2 INCHES ELSEWHERE. THIS IS
NOT ESF WORTHY...BUT IT WILL CONTINUE TO BE MONITORED.
TEMPERATURE WISE...NO BIG DEVIATIONS VERSUS THE MAV.
IN THE EXT FCST...BOUNDARY MOVES THROUGH WITH DRIER POP FREE WEATHER
FOR THE EARLY HALF OF THE WORK WEEK. MOISTURE...HOWEVER...WILL
RETURN AS THE SFC HIGH SHIFTS EAST AND ALLOWS A SOUTHERLY LOW LEVEL
FLOW TO RETURN. TEMPS THROUGH THE EXTENDED ARE LOOKING SEASONAL.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
01
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
344 PM CDT FRI MAY 31 2013
.TONIGHT...
INSTABILITY WAS HIGH ACROSS WEST CENTRAL TEXAS WITH RAP ML CAPES
EXCEEDING 5000 J/KG. A STRONG CAP HOWEVER WAS PREVENTING STORM
DEVELOPMENT. I DID ADD A SLIGHT CHANCE OF THUNDERSTORMS IN HASKELL
AND THROCKMORTON COUNTIES THIS EVENING...WHERE A CUMULUS FIELD WAS
BEGINNING TO DEVELOP IN AN AREA OF WEAK SURFACE CONVERGENCE EAST OF
THE DRYLINE. AGAIN...LIKE YESTERDAY...IF STORMS DO DEVELOP...THEY
COULD RAPIDLY BECOME SEVERE WITH LARGE HAIL AND DAMAGING WINDS. A
TORNADO IS ALSO NOT OUT OF QUESTION WITH VERY STRONG INSTABILITY
PRESENT.
OTHERWISE A WARM NIGHT WITH LOW LEVEL MOISTURE CONTINUING TO
FLOW FROM THE GULF MEXICO. STRATUS RETURNS AFTER MIDNIGHT...FROM THE
HILL COUNTRY. 850 MB LOW LEVEL JET AGAIN PICKS UP TO 45-50 KTS
TOWARD MIDNIGHT. PERSISTENCE FORECAST TONIGHT WITH LOWS IN THE LOWER
TO MID 70S.
.SATURDAY AND SUNDAY...
AS THE FRONT PUSHES SOUTH ACROSS THE AREA SATURDAY MORNING...THINGS
SHOULD STAY RELATIVELY QUITE. WITH DAYTIME HEATING AND DEWPOINTS
AROUND 70 DEGREES...SURFACE BASED CAPE WILL INCREASE TO AROUND 3500
J/KG BY MID AFTERNOON. WITH THE FORCING FROM THE FRONT...REALIZING
THIS INSTABILITY SHOULD NOT BE A PROBLEM. THE CIN VALUES ARE
REASONABLE...HIGH ENOUGH TO ALLOW THE INSTABILITY TO BUILD...BUT NOT
TOO MUCH TO KEEP ANY OF IT FROM BEING RELEASED. SHEAR WILL NOT BE
SPECTACULAR...BUT WITH 30 KTS THERE WILL BE ENOUGH FOR SUPPORT
VIGOROUS UPDRAFTS. THE MAIN THREAT WILL BE VERY LARGE HAIL. LOW
LEVEL SHEAR IS LACKLUSTER...ONLY MAYBE 10 KTS...SO THE TORNADO
THREAT SHOULD BE LIMITED...THOUGH IT CANNOT BE RULED OUT. IF A STORM
CAN STAY ALONG THE BOUNDARY FOR LONG ENOUGH...IT WILL BE POSSIBLE
FOR A CIRCULATION TO DEVELOP. THE MAIN AREA OF CONCERN IS THE
SOUTHEASTERN PART OF THE AREA...SOUTH OF A LINE FROM BROWNWOOD...TO
SAN ANGELO...TO OZONA. OTHERWISE...TEMPERATURES WILL COOL OFF A
LITTLE FROM FRIDAY BEHIND THE FRONT. HIGHS WILL GENERALLY BE IN THE
UPPER 80S TO LOWER 90S FOR SATURDAY AND SUNDAY. LOWS WILL IN THE 60S
TO LOWER 70S. RAIN CHANCES SHOULD MOVE OUT BY EARLY AFTERNOON ON
.SUNDAY NIGHT THROUGH FRIDAY...
RIDGE OF HIGH PRESSURE IN THE MID AND UPPER LEVELS ACROSS THE
ATMOSPHERE WILL BECOME ESTABLISHED FOR AT LEAST THE FIRST HALF OF
NEXT WEEK. TEMPERATURES WILL LIKELY SOAR WITH THE RIDGE...WITH THE
LOCATION OF THE THERMAL RIDGE SUGGESTING THAT READINGS AT LEAST
NEAR THE 100 DEGREE MARK ARE POSSIBLE FOR THE WESTERN HALF OF THE AREA.
THE GFS WEAKENS THE RIDGE FOR THE LAST HALF OF THE
WEEK...AND TRIES ANOTHER FRONT AND CONVECTION INTO THE ARE FOR
THURSDAY OR FRIDAY. ECMWF SHOWS A LITTLE MORE PERSISTENT
RIDGE...AND DELAYS ANY CONVECTION TIL FRIDAY. AT THIS
POINT...THINK KEEPING THE FORECAST DRY FOR NOW IS PROBABLY THE
BEST OPTION...AND LET THE UNCERTAINTIES SETTLE A LITTLE.
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 73 90 65 89 66 / 10 20 30 10 10
SAN ANGELO 74 93 71 91 69 / 5 30 30 20 10
JUNCTION 73 94 70 92 68 / 5 30 40 20 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
04/NR/07
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1241 PM EDT FRI MAY 31 2013
.SYNOPSIS...
HIGH PRESSURE WILL KEEP US IN THE SUMMER LIKE HEAT INTO
SATURDAY. BY THE END OF THE WEEKEND INTO EARLY NEXT WEEK A
FRONTAL SYSTEM WILL ARRIVE WITH INCREASING CHANCES OF
SHOWERS AND STORMS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 925 AM EDT FRIDAY...
OVERALL PERSISTENCE FORECAST IN STORE THRU THIS AFTERNOON WITH
LITTLE CHANGE SEEN ALOFT OFF MORNING SOUNDINGS WHILE PWATS HAVE
INCREASED A BIT FROM YDA. HOWEVER FOCUS REMAINS LIMITED GIVEN DRY
AIR LINGERING ALOFT UNDER THE CONTINUED 5H RIDGING AND SURFACE
HIGH PRESSURE EXTENDING FROM OFFSHORE. HEIGHTS DO FALL A LITTLE
THIS AFTERNOON AS MODIFIED CAPES BOUNCE ABOVE 1500-2000 J/KG AND
WEAK CONVERGENCE DEVELOPS FAR NW PER SOUTH/SE FLOW. ALSO SOME WEAK
MCON LOOKS TO TAKE SHAPE IN THE MORE MOIST LOW LEVEL WEAK RETURN
FLOW ACROSS THE FAR SOUTH BUT IFFY WITH COVERAGE AND IF ANY SHRA
WILL MAKE IT THIS FAR NORTH. OTRW LATEST HRRR AND RNK-WRF SHOWING
VERY ISOLATED COVERAGE MAINLY FAR NW LATER THIS AFTERNOON SO
KEEPING A 20/30 POP MENTION GOING DOWN ALONG THE WESTERN SPINE OF
THE APPS AND LITTLE ELSW. 12Z THICKNESS CLOSE TO THAT OF THU AND
GIVEN SIMILAR 85H TEMPS BUMPED UP HIGHS A FEW DEGREES WITH VALUES
AGAIN APPROACHING 90 SE.
TONIGHT...CONVECTION WEAKENS/ENDS ACROSS THE WEST AND WILL SEE
ANOTHER RIDE UP CLOSE TO THE SRN BLUE RIDGE AND ADJACENT AREAS OF
SOME LOWER CLOUDS BUT OVERALL PARTLY CLOUDY. MUGGY LOWS IN THE
UPPER 50S TO MID 60S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
AS OF 300 AM EDT THURSDAY...
BERMUDA RIDGING ACROSS THE SOUTHEAST AND MID ATLANTIC STATES WILL BE
STRONG ON FRIDAY...RESULTING IN ONLY AN ISOLATED CHANCE OF SHOWERS
AND THUNDERSTORMS WITH AFTERNOON HEATING...AND HIGHS REACHING THE
MID TO UPPER 80S MOST LOCATIONS. HOWEVER...WILL SEE A TREND WHERE
THE RIDGING PATTERN WILL GRADUALLY BREAK DOWN DURING THE WEEKEND AS
AN UPPER TROUGH SWINGS FROM THE NORTHERN PLAINS ON SATURDAY OVER THE
GREAT LAKES BY SUNDAY. AS SUCH...SHOWER AND THUNDERSTORM ACTIVITY
WILL BE WIDELY SCATTERED ACROSS THE MOUNTAINS ON SATURDAY...AND THEN
RATHER WIDESPREAD ACROSS THE MOUNTAINS ON SUNDAY AS A COLD FRONT
ASSOCIATED WITH THE UPPER TROUGH APPROACHES FROM THE WEST. THE COLD
FRONT IS EXPECTED TO PASS SLOWLY ACROSS OUR AREA SUNDAY NIGHT INTO
MONDAY.
DESPITE THE BREAKDOWN IN RIDGING...AFTERNOON TEMPERATURES FOR
SATURDAY AND SUNDAY WILL NOT FALL OFF MUCH AT ALL...RANGING FROM THE
MID 80S WEST TO NEAR 90 EAST FOR HIGHS BOTH DAYS. OVERNIGHT
TEMPERATURES WILL ALSO REMAIN WARM AND MUGGY THANKS TO THE MOIST
SOUTHWESTERLY WIND FLOW DURING THE PERIOD...WITH LOWS FALLING INTO
THE 60S MOST LOCATIONS.
WILL ALSO KEEP AN EYE OUT FOR PATCHY FOG EARLY EACH MORNING...MAINLY
IN THE RIVER VALLEYS AND ACROSS LOCATIONS WHICH RECEIVED SIGNIFICANT
RAINFALL FROM SHOWER AND THUNDERSTORM ACTIVITY THE EVENING BEFORE.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 AM EDT THURSDAY...
BLOCKING PATTERN CONTINUES TO RELAX ON MONDAY AS MID CONUS TROUGH
LIFTS NORTHEAST THROUGH THE GREAT LAKES AND INTO NEW ENGLAND. THIS
WILL ALLOW THE ACCOMPANYING SURFACE FRONT TO MOVE EAST CROSSING THE
MID ATLANTIC REGION. THE ECMWF IS THE MOST PROGRESSIVE MODEL WITH
THIS FEATURE...MOVING IT THROUGH OUR AREA AND OFF THE MID ATLANTIC
COAST MONDAY NIGHT. THE GFS IS ABOUT 12 HOURS SLOWER. PREFER THE
MORE PROGRESSIVE GUIDANCE WITH THE SURFACE FRONT WELL EAST OF THE
FORECAST AREA BY DAYBREAK TUESDAY. FOLLOWING THIS GUIDANCE...SHOWERS
AND STORMS ARE EXPECTED TO BECOME MORE NUMEROUS...MORE SO FOR MONDAY
AS THE ACTUAL SURFACE FRONT CROSSES THE MID ATLANTIC REGION.
WITH THE FRONTAL PASSAGE PROGGED FOR MONDAY...LOOKING AT RETURN OF
DRY WEATHER FOR TUESDAY AND THE MIDDLE OF NEXT WEEK...HIGH PRESSURE
SLIDING EAST ACROSS THE GREAT LAKES AND PROVIDING US WITH A SOMEWHAT
COOLER NORTHERLY FLOW. AIRMASS BEHIND THIS FRONT IS NOT NEARLY AS
COOL AS WHAT TRANSPIRED OVER THE MEMORIAL DAY HOLIDAY WEEKEND...85H
TEMPS ONLY DROPPING TO AROUND +8 TO +10 DEG C.
RETURN FLOW SHOULD DEVELOP FOR THE LATTER HALF OF NEXT WEEK...WINDS
BECOMING SOUTHERLY ON THE BACK SIDE OF THE SURFACE
HIGH...TEMPERATURES WARMING.
THIS WEEKEND IS THE OFFICIAL START OF THE 2013 HURRICANE SEASON.
EXPECTATIONS ARE FOR AN ABOVE NORMAL SEASON. THIS IS BASED ON SEA
SURFACE TEMPERATURES THAT ARE WARMER THAN NORMAL IN THE TROPICAL
ATLANTIC AND AN ENSO NEUTRAL PATTERN IN THE PACIFIC. THESE FACTORS,
ALONG WITH OTHER HEMISPHERIC DECADAL AND INTER-SEASONAL OSCILLATIONS
ARE SIGNALS FOR AN ACTIVE STORM SEASON. LONG TRACKING STORMS WILL BE
MORE COMMON THIS YEAR THAN IN 2012 FAVORING FORMATION IN THE
INTERTROPICAL CONVERGENCE ZONE. AS SUCH...THE RISK FOR CAT 3, CAT 4,
AND CAT 5 HURRICANES IS GREATER THIS YEAR THAN IN PREVIOUS YEARS.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
AS OF 1220 PM EDT FRIDAY...
PREVAILING VFR WILL CONTINUE ACROSS THE REGION THIS AFTERNOON INTO
SATURDAY. HOWEVER SOME CU/TCU WILL FORM THIS AFTERNOON ESPECIALLY
ACROSS THE MOUNTAINS. A FEW COULD FORM INTO SHOWERS OR THUNDERSTORMS
ALTHOUGH COVERAGE STILL LOOKS TO BE SPARSE. KBLF/KLWB STILL STAND
THE BEST CHANCE BUT SINCE SHOULD BE ISOLATED...WILL CONTINUE TO
LEAVE OUT OF THE TAFS.
MOISTURE FETCH WILL AGAIN INCREASE OVERNIGHT SIMILAR TO LAST NIGHT
WITH POTENTIAL TO SEE LOWER CIGS INCLUDING SOME STRATUS SPREAD NE
INTO SOUTHERN PORTIONS OF THE AREA LATE. LATEST NAM AGAIN LATCHES
ON TO THIS SCENARIO BUT WAS OVERDONE FOR THE MOST PART LAST NIGHT
GIVEN DRY AIR IN PLACE. HOWEVER LOW LEVEL MOISTURE RETURN LOOKS A
BIT MORE ROBUST TONIGHT ESPCLY WITH DEWPOINTS ON THE RISE SO PLAN
TO ADD IN A BIT MORE LOW END VFR/MVFR CIGS IN SPOTS TONIGHT.
FOG WILL AGAIN BE AN ISSUE AT KLWB AND PERHAPS KBCB IF THE LOWER
CLOUDS TO DO NOT MOVE IN ALLOWING FOR A PERIOD OF IFR ESPCLY KLWB
TOWARD DAYBREAK SATURDAY. MORNIGN CLOUDS SHOULD BE A BIT MORE
WIDESPREAD SATURDAY ESPCLY MOUNTAINS WITH PERIODIC VFR CU/AC
FIELDS KBCB AND POINTS WEST UNTIL CIGS MIX OUT WITH HEATING IN THE
AFTERNOON. WIDELY SCATTERED CONVECTION ALSO POSSIBLE MAINLY SE
WVA BUT NOT UNTIL LATER SATURDAY SO LEAVING OUT MENTION EARLY ON.
MOISTURE INCREASES EVEN MORE AHEAD OF A FRONT BY LATER SUNDAY AND
INTO EARLY NEXT WEEK. APPEARS SHOWERS AND STORMS WILL BRING SUB
VFR CONDITIONS TO THE REGION DURING THIS TIME WITH BEST CHANCES OF
MVFR/IFR OVER THE MOUNTAIN LOCATIONS SUNDAY AFTERNOON/EVENING AND
OUT EAST INTO MONDAY. FRONT PUSHES SLOWLY SE BY TUESDAY ALLOWING
A RETURN TO MOSTLY VFR BY THEN.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/WP
NEAR TERM...JH/WP
SHORT TERM...NF
LONG TERM...AMS/NF
AVIATION...JH/KM/WP
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1122 AM PDT Fri May 31 2013
.SYNOPSIS...
Most of the region will experience dry conditions today and
Saturday...coupled with warming temperatures. A relatively strong,
but not terribly wet, storm system will bring a cool-down with
some showers and breezy conditions this weekend. A dry and
warming period will greet the new work week with temperatures
increasing into the 80s by Wednesday with dry and warm conditions
rounding out next week.
&&
.DISCUSSION...
Rest of Today...Water vapor imagery was indicating that the slow
moving upper level trough...which brought showers over the past
few days...continued to slowly exit the region this morning.
Drier air behind the trough was now entrenched the entire region
save the northern tip of Idaho. Despite the punch of drier
air...relatively shallow instability and moisture remained fixed
over the northern tier of the forecast area...roughly from the
Okanogan Highlands to the mountains north of Lake Pend Oreille.
This has manifested itself as scattered showers...which thus far
have been largely terrain induced. Based on HRRR forecast data and
model soundings...the instability will remain sufficient for
continued shower formation through the afternoon. However the threat will
gradually decrease from the southwest as upper level ridging builds in
and begins to cap the depth of the convection. Remainder of the
forecast area will see primarily sunny conditions with
temperatures several degrees warmer than yesterday. fx
&&
.AVIATION...
18Z TAFS: VFR conditions expected at all sites through 18z
Saturday. High pressure building in from the southwest will bring
stable conditions to the area and begin to limit the shower threat
over the mountains north of the GEG-COE corridor. For
tonight...the entire region will be precipitation free with mostly
clear skies which will persist into Saturday morning. fx
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 66 45 71 49 67 47 / 0 0 0 30 60 40
Coeur d`Alene 66 42 71 45 66 45 / 0 0 10 30 60 50
Pullman 66 41 71 47 67 44 / 0 0 0 10 30 30
Lewiston 73 46 79 53 74 51 / 0 0 0 10 20 20
Colville 73 42 75 46 69 46 / 20 0 10 50 60 40
Sandpoint 66 39 70 43 66 42 / 20 10 10 30 70 50
Kellogg 61 42 68 47 63 44 / 10 0 0 20 70 50
Moses Lake 74 45 78 50 77 49 / 0 0 0 10 10 10
Wenatchee 73 50 76 52 75 52 / 0 0 0 10 10 0
Omak 73 44 76 46 71 47 / 0 0 20 40 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1248 PM CDT FRI MAY 31 2013
.UPDATE...
ISSUED AT 1114 AM CDT FRI MAY 31 2013
THE MAIN FOCUS THROUGH TONIGHT IS ON THE CONVECTIVE POTENTIAL
ACROSS THE REGION. CURRENT SURFACE ANALYSIS SHOWS AN UNCAPPED
ENVIRONMENT JUST OUT AHEAD OF A DRY LINE THAT RUNS FROM JUST EAST
OF THE TWIN CITIES ALONG THE INTERSTATE 35 CORRIDOR THROUGH
MINNESOTA AND IOWA. MODIFIED 31.14Z RAP SOUNDINGS SHOW AN UNCAPPED
FAT CAPE PROFILE BY EARLY AFTERNOON WITH OVER 2000 J/KG OF SURFACE
BASED CAPE DEVELOPING. DEEP SHEAR LOOKS FAVORABLE WITH THE 31.14Z
RAP SHOWING A 50-65KT 500MB JET STREAK EXTENDING FROM THE SOUTHERN
PLAINS NORTHEAST THROUGH THE UPPER MISSISSIPPI RIVER VALLEY
REGION. WITH THIS MID LEVEL JET STREAK NOT SHIFTING EAST MUCH
THROUGH TONIGHT...0-6KM SHEAR REMAINS HIGH AT AROUND 60KTS THROUGH
THIS AFTERNOON AND EVENING. DIRECTIONALLY...THE SHEAR IS MAINLY
UNIDIRECTIONAL OUT OF THE SOUTHWEST FROM THE LOW LEVELS UP...BUT
THERE IS ENOUGH OF A SOUTHERLY COMPONENT TO THE SURFACE WINDS THAT
0-1KM SHEAR STAYS UP AS WELL. GIVEN ALL THIS...THE CURRENT
EXPECTATION WITH STORM MODE IS THAT WITH THE HIGH CAPE/SHEAR
ENVIRONMENT IS THAT STORMS WILL RAPIDLY DEVELOP AHEAD OF THE DRY
LINE THROUGH THIS AFTERNOON WITH LARGE HAIL BEING THE MAIN THREAT
TO START WITH A FEW SUPERCELLS POSSIBLE. CAN NOT RULE OUT A
TORNADO DEVELOPING DURING THIS PHASE AS WELL...PARTICULARLY WHERE
SURFACE WINDS STAY MORE OUT OF THE SOUTH-SOUTHEAST. WITH
TIME...THE ISOLATED/SCATTERED CELLS SHOULD CONVERGE INTO A SQUALL
LINE THIS EVENING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 329 AM CDT FRI MAY 31 2013
TWO AREAS OF CONVECTION THIS MORNING THAT MAY IMPACT THE AREA. THE
FIRST IS PRIMARILY ALREADY OFF THE NORTHWEST OF THE AREA FROM
NORTHWEST MINNESOTA INTO WESTERN WISCONSIN. THIS AREA IS MOVING
OFF TO THE NORTH/NORTHEAST AND IS NOT EXPECTED TO IMPACT THE
FORECAST AREA. THE OTHER AREA OF CONVECTION IS OVER NORTHWEST
MISSOURI AND IS MOVING TO THE NORTHEAST. THE HRRR SEEMS TO BE
HANDLING THIS THE BEST...BUT IS CONSIDERABLY TOO SLOW WITH IT. THE
TREND FROM THE 31.04Z AND 31.05Z RUNS IS FOR THIS AREA TO MOVE
NORTHEAST ACROSS EASTERN IOWA INTO NORTHERN ILLINOIS AND FOR THE
MOST PART MISSING THE AREA TO THE SOUTH. THE 31.00Z ECMWF ALSO
SHOWS THIS AREA COMING OUT OF MISSOURI BUT TAKES IT FARTHER TO THE
NORTHWEST IMPACTING THE SOUTHERN AND EASTERN AREAS FROM LATE
MORNING THROUGH THE AFTERNOON. THE PREVIOUS FORECAST WAS TRENDED
TOWARD THE POSSIBILITY OF THIS CONVECTION COMING INTO THE AREA SO
HAVE MAINTAINED THESE TRENDS BUT LIMITED THE HIGHER RAIN CHANCES
TO THE SOUTHEAST SECTIONS OF THE FORECAST AREA. BY LATE IN THE
AFTERNOON AND INTO THE EVENING...ALL THE MODELS ARE SHOWING WHAT
LOOKS LIKE A DRY LINE/WIND SHIFT DEVELOPING AHEAD OF THE SURFACE
LOW AND MOVING EAST TOWARD THE AREA. THERE SHOULD BE ANOTHER SHORT
WAVE TROUGH ROUNDING THE UPPER LEVEL LOW TO PROVIDE DYNAMIC LIFT
OVER THIS DRY LINE/WIND SHIFT. BOTH THE 31.00Z NAM AND GFS SHOW A
JET CORE ALSO COMING AROUND THE UPPER LEVEL LOW WITH THE LEFT EXIT
REGION COMING OVER THE AREA TO ADD SOME AGEOSTROPHIC MOTIONS TO THE
FORCING FROM THE SHORT WAVE TROUGH. THIS SHOULD BE ENOUGH FORCING
TO CAUSE A LINE OF CONVECTION TO DEVELOP ALONG THIS DRY LINE AND
THEN WORK RAPIDLY EAST ACROSS THE AREA DURING THE EVENING. SOME
POTENTIAL FOR SEVERE TODAY...BUT THIS IS DEFINITELY NOT AS HIGH AS
THE PAST COUPLE OF DAYS. ML CAPES OF 1000 TO POSSIBLY AS MUCH AS
2000 J/KG SHOULD DEVELOP TODAY AHEAD OF THE DRY LINE. THE BEST
0-6KM SHEAR WILL BE WELL OUT AHEAD OF THE DRY LINE AND WILL LINE
UP BETTER WITH THE EXPECTED CONVECTION TO COME NORTHEAST OUT OF
MISSOURI. HOWEVER...THE 0-3 KM SHEAR SHOULD BE AROUND 30 KNOTS
AHEAD OF THE DRY LINE SO THE POTENTIAL FOR STORMS THIS AFTERNOON
AND EVENING TO PRODUCE DAMAGING WINDS AND HAIL. ALL THE ACTIVITY
SHOULD QUICKLY DIE DOWN AFTER MIDNIGHT AS IT MOVES OFF TO THE EAST
OF THE AREA. BOTH THE NAM AND GFS SHOW THE PRECIPITABLE WATERS
LOWERING DURING THE DAY AS DRIER AIR WRAPS IN FROM THE WEST. WHILE
ANY THUNDERSTORMS MAY PRODUCE SOME LOCALLY HEAVY RAIN...FEEL THAT
THE POTENTIAL FOR WIDESPREAD HEAVY RAINS TO PRODUCE FLASH FLOODING
IS NOT THERE TO SUPPORT THE NEED FOR ANOTHER FLASH FLOOD WATCH.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 329 AM CDT FRI MAY 31 2013
AT LONG LAST...THIS STUBBORN SYSTEM WILL BEGIN TO MAKE A MOVE TO
THE EAST SATURDAY. AS IT DOES...THE SURFACE LOW WILL MOVE FROM
CENTRAL MINNESOTA INTO NORTHERN WISCONSIN AS THE UPPER LEVEL LOW
BECOMES AN OPEN WAVE. THE LAST SHORT WAVE TROUGH WITH THIS SYSTEM
IS EXPECTED TO BE MOVING ACROSS THE AREA AND BE PRODUCING AROUND 8
PVU/S OF VORTICITY ADVECTION IN THE 500-300 MB LAYER. THIS FORCING
FROM THE WAVE COMBINED WITH BEING IN THE DEFORMATION AREA OF THE
SURFACE LOW SHOULD BE ENOUGH TO GENERATE SHOWERS ACROSS MUCH OF
THE AREA. MU CAPES SHOULD BE AROUND 200-300 J/KG IN THE AFTERNOON
WHICH WILL BE GOOD ENOUGH TO PRODUCE SOME ISOLATED THUNDER. THE
REMAINING SHOWERS SHOULD THEN MOVE OFF TO THE EAST SATURDAY NIGHT
WITH SUNDAY BEING THE FIRST DAY IN ABOUT A WEEK WITH NO CHANCE OF
RAIN. MONDAY ALSO LOOKS TO BE DRY WITH HIGH PRESSURE OVER THE AREA
BUT THEN THE RAIN CHANCES START TO RETURN FOR MONDAY NIGHT. THE
31.00Z GFS...GEM AND ECMWF ALL SHOW ANOTHER CLOSED LOW MOVING
TOWARD THE AREA FROM THE PACIFIC NORTHWEST. PLENTY OF DIFFERENCES
THOUGH ON HOW FAST THIS SYSTEM WILL START TO IMPACT THE AREA. THE
OPERATIONAL GFS IS THE FASTEST BRINGING THIS SYSTEM IN...EVEN
FASTER THAN ITS ENSEMBLE MEAN WHILE THE ECMWF IS THE SLOWEST. THIS
LOOKS TO BE ANOTHER SLOW MOVING SYSTEM KEEPING RAIN CHANCES IN THE
FORECAST FOR THE REMAINDER OF THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1248 PM CDT FRI MAY 31 2013
THE MAIN FOCUS AT THE TAF SITES IS WITH THE TIMING ON WHEN ANY
SHOWERS OR THUNDERSTORMS WILL GET INTO THE TAF SITES. SHOWERS HAVE
ALREADY DEVELOPED NEAR RST AND WILL DRIFT TO THE EAST THROUGH THE
AFTERNOON. WITH AN UNSTABLE ENVIRONMENT IN PLACE...THESE SHOWERS
WILL QUICKLY STRENGTHEN EARLY THIS AFTERNOON WITH THUNDERSTORMS
LIKELY AT RST BETWEEN 19Z/23Z. AS THE STORMS MARCH EAST...THEY
SHOULD REACH LSE SOMETIME BETWEEN 23Z AND 02Z. MVFR CUMULUS FIELD
WILL LIKELY STAY IN PLACE OR GRADUALLY CLIMB THIS AFTERNOON BEFORE
MVFR/IFR CONDITIONS COME IN WITH THE THUNDERSTORMS. CONDITIONS
SHOULD CLEAR OUT LATER THIS EVENING WITH WINDS SUBSIDING
OVERNIGHT.
&&
.HYDROLOGY...
ISSUED AT 329 AM CDT FRI MAY 31 2013
TURKEY RIVER...
WITH THURSDAY BEING MUCH DRIER THAN EXPECTED IN NORTHEAST IOWA...THE
TURKEY RIVER IS COMING IN MUCH LOWER THAN ORIGINALLY ANTICIPATED.
ELKADER IS EXPECTED TO CREST AROUND 16.5 FEET. THIS IS ABOUT 2 FEET
LOWER THAN THE PREVIOUS FORECAST. THIS IN TURN WILL RESULT IN A MUCH
LOWER CREST FOR GARBER. THE RIVER HAS ALREADY CRESTED AROUND
22.1 FEET. IT SHOULD REMAIN AROUND THIS LEVEL THROUGH MUCH OF TODAY
AND THEN BEGIN A SLOW FALL.
UPPER IOWA...
DORCHESTER HAS FLATTENED OUT AROUND 13.4 FEET. WITH DECORAH
CONTINUING TO RISE UPSTREAM...EXPECT THAT DORCHESTER WILL ONCE AGAIN
START TO RISE THIS MORNING. CONSIDERING THE RAINFALL ACROSS THIS
BASIN ON THURSDAY STILL NOT QUITE SURE WHETHER THE CREST LATER THIS
AFTERNOON WILL BE ABOUT A HALF FEET /15.5 FEET/ HIGHER THAN ITS
PREVIOUS CREST OF 15 FEET ON THURSDAY MORNING. AM MORE INCLINED THAT
IT WILL COME IN WITH A SIMILAR AS THURSDAY MORNING.
KICKAPOO RIVER...
THE UPPER REACHES OF THE KICKAPOO HAVE ALREADY CRESTED AND STARTED
TO FALL RAPIDLY...THEREFORE...LA FARGE WILL BE ADJUSTED TO CREST
LOWER THAN EXPECTED /STILL BELOW FLOOD STAGE/
BLACK RIVER...
BLACK RIVER FALLS IS CONTINUING TO RISE RATHER RAPIDLY THIS MORNING.
LOOKING AT THE WATER UPSTREAM...THE NORTH CENTRAL RIVER FORECAST
CENTER IS EXPECTING IT TO NOW CREST AROUND 49.3 FEET LATER TODAY.
TREMPEALEAU RIVER...
DUE TO THE BROADER EXPANSE NEAR DODGE...EXPECT TO SEE A SLOW AND
STEADY RISE INTO THE WEEKEND. IT STILL LOOKS LIKE IT WILL CREST ON
SUNDAY AROUND 9.6 FEET.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...HALBACH
SHORT TERM...04
LONG TERM...04
AVIATION...HALBACH
HYDROLOGY...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1114 AM CDT FRI MAY 31 2013
.UPDATE...
ISSUED AT 1114 AM CDT FRI MAY 31 2013
THE MAIN FOCUS THROUGH TONIGHT IS ON THE CONVECTIVE POTENTIAL
ACROSS THE REGION. CURRENT SURFACE ANALYSIS SHOWS AN UNCAPPED
ENVIRONMENT JUST OUT AHEAD OF A DRY LINE THAT RUNS FROM JUST EAST
OF THE TWIN CITIES ALONG THE INTERSTATE 35 CORRIDOR THROUGH
MINNESOTA AND IOWA. MODIFIED 31.14Z RAP SOUNDINGS SHOW AN UNCAPPED
FAT CAPE PROFILE BY EARLY AFTERNOON WITH OVER 2000 J/KG OF SURFACE
BASED CAPE DEVELOPING. DEEP SHEAR LOOKS FAVORABLE WITH THE 31.14Z
RAP SHOWING A 50-65KT 500MB JET STREAK EXTENDING FROM THE SOUTHERN
PLAINS NORTHEAST THROUGH THE UPPER MISSISSIPPI RIVER VALLEY
REGION. WITH THIS MID LEVEL JET STREAK NOT SHIFTING EAST MUCH
THROUGH TONIGHT...0-6KM SHEAR REMAINS HIGH AT AROUND 60KTS THROUGH
THIS AFTERNOON AND EVENING. DIRECTIONALLY...THE SHEAR IS MAINLY
UNIDIRECTIONAL OUT OF THE SOUTHWEST FROM THE LOW LEVELS UP...BUT
THERE IS ENOUGH OF A SOUTHERLY COMPONENT TO THE SURFACE WINDS THAT
0-1KM SHEAR STAYS UP AS WELL. GIVEN ALL THIS...THE CURRENT
EXPECTATION WITH STORM MODE IS THAT WITH THE HIGH CAPE/SHEAR
ENVIRONMENT IS THAT STORMS WILL RAPIDLY DEVELOP AHEAD OF THE DRY
LINE THROUGH THIS AFTERNOON WITH LARGE HAIL BEING THE MAIN THREAT
TO START WITH A FEW SUPERCELLS POSSIBLE. CAN NOT RULE OUT A
TORNADO DEVELOPING DURING THIS PHASE AS WELL...PARTICULARLY WHERE
SURFACE WINDS STAY MORE OUT OF THE SOUTH-SOUTHEAST. WITH
TIME...THE ISOLATED/SCATTERED CELLS SHOULD CONVERGE INTO A SQUALL
LINE THIS EVENING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 329 AM CDT FRI MAY 31 2013
TWO AREAS OF CONVECTION THIS MORNING THAT MAY IMPACT THE AREA. THE
FIRST IS PRIMARILY ALREADY OFF THE NORTHWEST OF THE AREA FROM
NORTHWEST MINNESOTA INTO WESTERN WISCONSIN. THIS AREA IS MOVING
OFF TO THE NORTH/NORTHEAST AND IS NOT EXPECTED TO IMPACT THE
FORECAST AREA. THE OTHER AREA OF CONVECTION IS OVER NORTHWEST
MISSOURI AND IS MOVING TO THE NORTHEAST. THE HRRR SEEMS TO BE
HANDLING THIS THE BEST...BUT IS CONSIDERABLY TOO SLOW WITH IT. THE
TREND FROM THE 31.04Z AND 31.05Z RUNS IS FOR THIS AREA TO MOVE
NORTHEAST ACROSS EASTERN IOWA INTO NORTHERN ILLINOIS AND FOR THE
MOST PART MISSING THE AREA TO THE SOUTH. THE 31.00Z ECMWF ALSO
SHOWS THIS AREA COMING OUT OF MISSOURI BUT TAKES IT FARTHER TO THE
NORTHWEST IMPACTING THE SOUTHERN AND EASTERN AREAS FROM LATE
MORNING THROUGH THE AFTERNOON. THE PREVIOUS FORECAST WAS TRENDED
TOWARD THE POSSIBILITY OF THIS CONVECTION COMING INTO THE AREA SO
HAVE MAINTAINED THESE TRENDS BUT LIMITED THE HIGHER RAIN CHANCES
TO THE SOUTHEAST SECTIONS OF THE FORECAST AREA. BY LATE IN THE
AFTERNOON AND INTO THE EVENING...ALL THE MODELS ARE SHOWING WHAT
LOOKS LIKE A DRY LINE/WIND SHIFT DEVELOPING AHEAD OF THE SURFACE
LOW AND MOVING EAST TOWARD THE AREA. THERE SHOULD BE ANOTHER SHORT
WAVE TROUGH ROUNDING THE UPPER LEVEL LOW TO PROVIDE DYNAMIC LIFT
OVER THIS DRY LINE/WIND SHIFT. BOTH THE 31.00Z NAM AND GFS SHOW A
JET CORE ALSO COMING AROUND THE UPPER LEVEL LOW WITH THE LEFT EXIT
REGION COMING OVER THE AREA TO ADD SOME AGEOSTROPHIC MOTIONS TO THE
FORCING FROM THE SHORT WAVE TROUGH. THIS SHOULD BE ENOUGH FORCING
TO CAUSE A LINE OF CONVECTION TO DEVELOP ALONG THIS DRY LINE AND
THEN WORK RAPIDLY EAST ACROSS THE AREA DURING THE EVENING. SOME
POTENTIAL FOR SEVERE TODAY...BUT THIS IS DEFINITELY NOT AS HIGH AS
THE PAST COUPLE OF DAYS. ML CAPES OF 1000 TO POSSIBLY AS MUCH AS
2000 J/KG SHOULD DEVELOP TODAY AHEAD OF THE DRY LINE. THE BEST
0-6KM SHEAR WILL BE WELL OUT AHEAD OF THE DRY LINE AND WILL LINE
UP BETTER WITH THE EXPECTED CONVECTION TO COME NORTHEAST OUT OF
MISSOURI. HOWEVER...THE 0-3 KM SHEAR SHOULD BE AROUND 30 KNOTS
AHEAD OF THE DRY LINE SO THE POTENTIAL FOR STORMS THIS AFTERNOON
AND EVENING TO PRODUCE DAMAGING WINDS AND HAIL. ALL THE ACTIVITY
SHOULD QUICKLY DIE DOWN AFTER MIDNIGHT AS IT MOVES OFF TO THE EAST
OF THE AREA. BOTH THE NAM AND GFS SHOW THE PRECIPITABLE WATERS
LOWERING DURING THE DAY AS DRIER AIR WRAPS IN FROM THE WEST. WHILE
ANY THUNDERSTORMS MAY PRODUCE SOME LOCALLY HEAVY RAIN...FEEL THAT
THE POTENTIAL FOR WIDESPREAD HEAVY RAINS TO PRODUCE FLASH FLOODING
IS NOT THERE TO SUPPORT THE NEED FOR ANOTHER FLASH FLOOD WATCH.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 329 AM CDT FRI MAY 31 2013
AT LONG LAST...THIS STUBBORN SYSTEM WILL BEGIN TO MAKE A MOVE TO
THE EAST SATURDAY. AS IT DOES...THE SURFACE LOW WILL MOVE FROM
CENTRAL MINNESOTA INTO NORTHERN WISCONSIN AS THE UPPER LEVEL LOW
BECOMES AN OPEN WAVE. THE LAST SHORT WAVE TROUGH WITH THIS SYSTEM
IS EXPECTED TO BE MOVING ACROSS THE AREA AND BE PRODUCING AROUND 8
PVU/S OF VORTICITY ADVECTION IN THE 500-300 MB LAYER. THIS FORCING
FROM THE WAVE COMBINED WITH BEING IN THE DEFORMATION AREA OF THE
SURFACE LOW SHOULD BE ENOUGH TO GENERATE SHOWERS ACROSS MUCH OF
THE AREA. MU CAPES SHOULD BE AROUND 200-300 J/KG IN THE AFTERNOON
WHICH WILL BE GOOD ENOUGH TO PRODUCE SOME ISOLATED THUNDER. THE
REMAINING SHOWERS SHOULD THEN MOVE OFF TO THE EAST SATURDAY NIGHT
WITH SUNDAY BEING THE FIRST DAY IN ABOUT A WEEK WITH NO CHANCE OF
RAIN. MONDAY ALSO LOOKS TO BE DRY WITH HIGH PRESSURE OVER THE AREA
BUT THEN THE RAIN CHANCES START TO RETURN FOR MONDAY NIGHT. THE
31.00Z GFS...GEM AND ECMWF ALL SHOW ANOTHER CLOSED LOW MOVING
TOWARD THE AREA FROM THE PACIFIC NORTHWEST. PLENTY OF DIFFERENCES
THOUGH ON HOW FAST THIS SYSTEM WILL START TO IMPACT THE AREA. THE
OPERATIONAL GFS IS THE FASTEST BRINGING THIS SYSTEM IN...EVEN
FASTER THAN ITS ENSEMBLE MEAN WHILE THE ECMWF IS THE SLOWEST. THIS
LOOKS TO BE ANOTHER SLOW MOVING SYSTEM KEEPING RAIN CHANCES IN THE
FORECAST FOR THE REMAINDER OF THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 700 AM CDT FRI MAY 31 2013
IFR TO MVFR CEILINGS WILL GRADUALLY BECOME VFR BY 31.15Z. SHOWERS
AND THUNDERSTORMS WILL DEVELOP AHEAD OF A COLD FRONT LATE THIS
AFTERNOON AND EVENING. THESE THUNDERSTORMS WILL AFFECT KRST
BETWEEN 31.22Z AND 01.04Z...AND KLSE BETWEEN 01.00Z AND 01.06Z. A
FEW OF THESE THUNDERSTORMS MAY BECOME SEVERE. THE MAIN THREATS
WILL BE LARGE HAIL AND DAMAGING WINDS. THERE MAY BE EVEN AN
ISOLATED TORNADO. ONCE THE FRONT CLEARS THE AREA CEILINGS WILL
CLIMB TO AROUND 10K FEET.
&&
.HYDROLOGY...
ISSUED AT 329 AM CDT FRI MAY 31 2013
TURKEY RIVER...
WITH THURSDAY BEING MUCH DRIER THAN EXPECTED IN NORTHEAST IOWA...THE
TURKEY RIVER IS COMING IN MUCH LOWER THAN ORIGINALLY ANTICIPATED.
ELKADER IS EXPECTED TO CREST AROUND 16.5 FEET. THIS IS ABOUT 2 FEET
LOWER THAN THE PREVIOUS FORECAST. THIS IN TURN WILL RESULT IN A MUCH
LOWER CREST FOR GARBER. THE RIVER HAS ALREADY CRESTED AROUND
22.1 FEET. IT SHOULD REMAIN AROUND THIS LEVEL THROUGH MUCH OF TODAY
AND THEN BEGIN A SLOW FALL.
UPPER IOWA...
DORCHESTER HAS FLATTENED OUT AROUND 13.4 FEET. WITH DECORAH
CONTINUING TO RISE UPSTREAM...EXPECT THAT DORCHESTER WILL ONCE AGAIN
START TO RISE THIS MORNING. CONSIDERING THE RAINFALL ACROSS THIS
BASIN ON THURSDAY STILL NOT QUITE SURE WHETHER THE CREST LATER THIS
AFTERNOON WILL BE ABOUT A HALF FEET /15.5 FEET/ HIGHER THAN ITS
PREVIOUS CREST OF 15 FEET ON THURSDAY MORNING. AM MORE INCLINED THAT
IT WILL COME IN WITH A SIMILAR AS THURSDAY MORNING.
KICKAPOO RIVER...
THE UPPER REACHES OF THE KICKAPOO HAVE ALREADY CRESTED AND STARTED
TO FALL RAPIDLY...THEREFORE...LA FARGE WILL BE ADJUSTED TO CREST
LOWER THAN EXPECTED /STILL BELOW FLOOD STAGE/
BLACK RIVER...
BLACK RIVER FALLS IS CONTINUING TO RISE RATHER RAPIDLY THIS MORNING.
LOOKING AT THE WATER UPSTREAM...THE NORTH CENTRAL RIVER FORECAST
CENTER IS EXPECTING IT TO NOW CREST AROUND 49.3 FEET LATER TODAY.
TREMPEALEAU RIVER...
DUE TO THE BROADER EXPANSE NEAR DODGE...EXPECT TO SEE A SLOW AND
STEADY RISE INTO THE WEEKEND. IT STILL LOOKS LIKE IT WILL CREST ON
SUNDAY AROUND 9.6 FEET.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...HALBACH
SHORT TERM...04
LONG TERM...04
AVIATION...BOYNE
HYDROLOGY...BOYNE