Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/30/13
AREA FORECAST DISCUSSION...UPDATED
NWS LITTLE ROCK AR
1145 AM CDT TUE MAY 28 2013
.DISCUSSION...
UPDATED TO INCLUDE THE 18Z AVIATION DISCUSSION BELOW...
&&
.AVIATION...
SHRA AND/OR A FEW TSRA WILL BE POSSIBLE ACROSS THE NRN SITES
THROUGH THE NEXT FEW HRS...BUT CHANCES WILL DIMINISH BEYOND THAT
TIME FRAME. HOWEVER...SOME ISOLATED AFTERNOON PRECIP ACTIVITY
COULD STILL BE POSSIBLE. OTHER THAN SOME LOW CIGS/FOG DURING THE
OVERNIGHT PERIOD...AND SOME BREEZY SRLY WINDS...VFR CONDITIONS
SHOULD PREVAIL.
&&
PREV DISCUSSION... /ISSUED 325 AM CDT TUE MAY 28 2013/
SHORT TERM...TODAY THROUGH SUNDAY
REGIONAL RADAR OBSERVATIONS SHOW SOME DEVELOPING ISOLATED SHOWER
ACTIVITY STRETCHING FROM WEST OF FORT SMITH UP THROUGH HARRISON.
THE HRRR MODEL HAS A VERY GOOD HANDLE ON THIS AND SHOWS THIS
ACTIVITY CONTINUING TO DEVELOP/EXPAND AS IT MOVES EAST ACROSS THE
NORTHERN PARTS OF ARKANSAS. WENT AHEAD AND INCLUDED SOME SLIGHT
CHANCE POPS FOR SHOWERS THROUGH MIDDAY. OTHERWISE TODAY SHOULD BE
DRY. HIGH TEMPERATURES TODAY WILL BE SIMILAR TO YESTERDAY...IF NOT
A DEGREE WARMER IN HIGHER ELEVATIONS.
ALOFT...AN UPPER TROUGH IS BEGINNING TO TAKE SHAPE OUT WEST. THE
TROUGH AXIS WILL GRADUALLY SHIFT EAST THROUGH THE END OF THE WEEK.
IMPULSES EJECTING FROM THIS UPPER TROUGH WILL GENERATE CONVECTION
EAST OF A SURFACE LOW AND DRY LINE SETUP STRETCHING FROM THE HIGH
PLAINS OF COLORADO AND WESTERN KANSAS DOWN INTO THE PANHANDLE OF
TEXAS. AS THE UPPER TROUGH SHIFTS EAST...THESE IMPULSES AND THEIR
ASSOCIATED CONVECTION WILL DO THE SAME. SOME ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS MAY EXIST IN SE ARKANSAS TOMORROW
MORNING AS MOISTURE TRANSPORT STRENGTHENS...BUT BETTER RAIN
CHANCES WILL MOVE INTO WESTERN ARKANSAS WED EVENING AS ONE OF THE
AFOREMENTIONED IMPULSES MOVES THROUGH THE SOUTHERN PLAINS. EXPECT
THERE WILL BE SOME ONGOING CONVECTION PRESENT ACROSS MUCH OF THE
NWRN HALF OF THE STATE BY THURSDAY MORNING...WHICH IS WHEN THE
HIGHEST RAIN CHANCES OF THE SHORT TERM WILL EXIST. CLOUD COVER AND
RAIN COOLED AIR MAY DISRUPT DIURNAL THUNDERSTORM DEVELOPMENT THU
AFTERNOON...BUT GUIDANCE SHOWS ANOTHER SHORTWAVE AND ASSOC SURFACE
LOW MOVING EAST ACROSS OKLAHOMA THU NIGHT. THERE COULD BE SOME MCS
ACTIVITY MOVING THROUGH NW ARKANSAS AND SRN MISSOURI LATE THU
NIGHT AS A RESULT.
FRIDAY LOOKS TO BE DRY WITH ONLY AFTERNOON CU FOR CLOUD COVER.
TEMPERATURES WED THROUGH FRIDAY WILL BE SLIGHTLY BELOW NORMAL FOR
THE NORTHWEST HALF OF THE STATE BUT SHOULD BE CLOSE TO
CLIMATOLOGICAL NORMS FOR THE SOUTHEAST.
LONG TERM...SATURDAY THROUGH MONDAY
TO START THE EXTENDED...THE BROAD UPPER LOW PRESSURE TROUGH IS
EXPECTED TO SETTLE SE TO THE CENTRAL PLAINS...AS A SURFACE COLD
FRONT ALSO DRIFTS TO THE PLAINS. THE UPPER SW FLOW WILL BRING SHORT
WAVE ENERGY TO AR AND A CHANCE OF CONVECTION IS EXPECTED OVER ALL OF
AR. ADDITIONAL RAIN IS EXPECTED SATURDAY NIGHT AND SUNDAY...AS THE
COLD FRONT SAGS INTO AR AND ADDITIONAL UPPER ENERGY MOVES OVER AR.
AREAS OF HEAVY RAIN MAY BE POSSIBLE. SUNDAY NIGHT...THE COLD FRONT
GRADUALLY SAGS SOUTH TO NEAR THE AR AND LA STATE LINE...AS THE UPPER
TROUGH BOTTOMS OUT OVER THE TN VALLEY. ON MONDAY...DRIER AND A BIT
COOLER TEMPS ARE EXPECTED AS THE UPPER TROUGH MOVES EAST AND UPPER
RIDGING GRADUALLY MOVES INTO THE REGION. SOME UNCERTAINTY DOES EXIST
ON HOW FAR THE UPPER TROUGH TAKES THE COLD FRONT. IT IS THE END OF
MAY AND A BIT UNUSUALLY TO HAVE A COLD FRONT PUSH THIS FAR SOUTH.
TEMPERATURES WILL BE AROUND NORMAL VALUES...THEN COOL A BIT IF THE
AIR MASS FILTERS IN BEHIND THE FRONT.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 87 68 86 69 / 10 10 10 30
CAMDEN AR 88 69 87 70 / 10 10 20 20
HARRISON AR 84 67 83 67 / 20 10 20 40
HOT SPRINGS AR 86 69 85 70 / 10 10 20 30
LITTLE ROCK AR 88 70 87 70 / 10 10 10 30
MONTICELLO AR 89 70 86 70 / 10 10 20 20
MOUNT IDA AR 85 68 84 70 / 10 10 20 30
MOUNTAIN HOME AR 86 68 85 68 / 20 10 20 40
NEWPORT AR 88 69 86 70 / 10 10 10 30
PINE BLUFF AR 88 69 86 70 / 10 10 20 20
RUSSELLVILLE AR 87 69 85 69 / 10 10 20 30
SEARCY AR 87 69 86 69 / 10 10 10 30
STUTTGART AR 88 70 86 70 / 10 10 20 20
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AVIATION...62
AREA FORECAST DISCUSSION...UPDATE FOR AVIATION
NWS LITTLE ROCK AR
630 AM CDT TUE MAY 28 2013
.AVIATION...
OVERALL VFR CONDITIONS ARE EXPECTED OVER THE NEXT 24 HOURS.
INCREASING MID AND HIGH CLOUDS...WITH CEILINGS...WILL SPREAD
OVER AR TODAY. PATCHY MVFR CONDITIONS WILL BE SEEN THIS MORNING BUT
WILL THIN AS WINDS INCREASE THROUGH THE MORNING. A FEW ISOLATED
SHOWERS WILL BE POSSIBLE THIS MORNING OVER NORTHERN AR BUT ONLY USED
VCSH DUE TO UNCERTAINTY. WINDS WILL BE SE TO S AT 5 TO 15 KNOTS THIS
MORNING...THEN BECOME SE TO SW AT 10 TO 20 KNOTS WITH SOME GUSTS TO
25 KNOTS INTO THE AFTERNOON. A LOW LEVEL JET WILL SET UP ACROSS AR
AND PRODUCE WIND SHEAR FROM THE S TO SW AT 30 TO 45 KNOTS TO 2000
FEET. (59)
&&
.PREV DISCUSSION... /ISSUED 325 AM CDT TUE MAY 28 2013/
.SHORT TERM...TODAY THROUGH SUNDAY
REGIONAL RADAR OBSERVATIONS SHOW SOME DEVELOPING ISOLATED SHOWER
ACTIVITY STRETCHING FROM WEST OF FORT SMITH UP THROUGH HARRISON.
THE HRRR MODEL HAS A VERY GOOD HANDLE ON THIS AND SHOWS THIS
ACTIVITY CONTINUING TO DEVELOP/EXPAND AS IT MOVES EAST ACROSS THE
NORTHERN PARTS OF ARKANSAS. WENT AHEAD AND INCLUDED SOME SLIGHT
CHANCE POPS FOR SHOWERS THROUGH MIDDAY. OTHERWISE TODAY SHOULD BE
DRY. HIGH TEMPERATURES TODAY WILL BE SIMILAR TO YESTERDAY...IF NOT
A DEGREE WARMER IN HIGHER ELEVATIONS.
ALOFT...AN UPPER TROUGH IS BEGINNING TO TAKE SHAPE OUT WEST. THE
TROUGH AXIS WILL GRADUALLY SHIFT EAST THROUGH THE END OF THE WEEK.
IMPULSES EJECTING FROM THIS UPPER TROUGH WILL GENERATE CONVECTION
EAST OF A SURFACE LOW AND DRY LINE SETUP STRETCHING FROM THE HIGH
PLAINS OF COLORADO AND WESTERN KANSAS DOWN INTO THE PANHANDLE OF
TEXAS. AS THE UPPER TROUGH SHIFTS EAST...THESE IMPULSES AND THEIR
ASSOCIATED CONVECTION WILL DO THE SAME. SOME ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS MAY EXIST IN SE ARKANSAS TOMORROW
MORNING AS MOISTURE TRANSPORT STRENGTHENS...BUT BETTER RAIN
CHANCES WILL MOVE INTO WESTERN ARKANSAS WED EVENING AS ONE OF THE
AFOREMENTIONED IMPULSES MOVES THROUGH THE SOUTHERN PLAINS. EXPECT
THERE WILL BE SOME ONGOING CONVECTION PRESENT ACROSS MUCH OF THE
NWRN HALF OF THE STATE BY THURSDAY MORNING...WHICH IS WHEN THE
HIGHEST RAIN CHANCES OF THE SHORT TERM WILL EXIST. CLOUD COVER AND
RAIN COOLED AIR MAY DISRUPT DIURNAL THUNDERSTORM DEVELOPMENT THU
AFTERNOON...BUT GUIDANCE SHOWS ANOTHER SHORTWAVE AND ASSOC SURFACE
LOW MOVING EAST ACROSS OKLAHOMA THU NIGHT. THERE COULD BE SOME MCS
ACTIVITY MOVING THROUGH NW ARKANSAS AND SRN MISSOURI LATE THU
NIGHT AS A RESULT.
FRIDAY LOOKS TO BE DRY WITH ONLY AFTERNOON CU FOR CLOUD COVER.
TEMPERATURES WED THROUGH FRIDAY WILL BE SLIGHTLY BELOW NORMAL FOR
THE NORTHWEST HALF OF THE STATE BUT SHOULD BE CLOSE TO
CLIMATOLOGICAL NORMS FOR THE SOUTHEAST.
&&
.LONG TERM...SATURDAY THROUGH MONDAY
TO START THE EXTENDED...THE BROAD UPPER LOW PRESSURE TROUGH IS
EXPECTED TO SETTLE SE TO THE CENTRAL PLAINS...AS A SURFACE COLD
FRONT ALSO DRIFTS TO THE PLAINS. THE UPPER SW FLOW WILL BRING SHORT
WAVE ENERGY TO AR AND A CHANCE OF CONVECTION IS EXPECTED OVER ALL OF
AR. ADDITIONAL RAIN IS EXPECTED SATURDAY NIGHT AND SUNDAY...AS THE
COLD FRONT SAGS INTO AR AND ADDITIONAL UPPER ENERGY MOVES OVER AR.
AREAS OF HEAVY RAIN MAY BE POSSIBLE. SUNDAY NIGHT...THE COLD FRONT
GRADUALLY SAGS SOUTH TO NEAR THE AR AND LA STATE LINE...AS THE UPPER
TROUGH BOTTOMS OUT OVER THE TN VALLEY. ON MONDAY...DRIER AND A BIT
COOLER TEMPS ARE EXPECTED AS THE UPPER TROUGH MOVES EAST AND UPPER
RIDGING GRADUALLY MOVES INTO THE REGION. SOME UNCERTAINTY DOES EXIST
ON HOW FAR THE UPPER TROUGH TAKES THE COLD FRONT. IT IS THE END OF
MAY AND A BIT UNUSUALLY TO HAVE A COLD FRONT PUSH THIS FAR SOUTH.
TEMPERATURES WILL BE AROUND NORMAL VALUES...THEN COOL A BIT IF THE
AIR MASS FILTERS IN BEHIND THE FRONT.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 87 68 86 69 / 10 10 10 30
CAMDEN AR 88 69 87 70 / 10 10 20 20
HARRISON AR 84 67 83 67 / 10 10 20 40
HOT SPRINGS AR 86 69 85 70 / 10 10 20 30
LITTLE ROCK AR 88 70 87 70 / 10 10 10 30
MONTICELLO AR 89 70 86 70 / 10 10 20 20
MOUNT IDA AR 85 68 84 70 / 10 10 20 30
MOUNTAIN HOME AR 86 68 85 68 / 20 10 20 40
NEWPORT AR 88 69 86 70 / 10 10 10 30
PINE BLUFF AR 88 69 86 70 / 10 10 20 20
RUSSELLVILLE AR 87 69 85 69 / 10 10 20 30
SEARCY AR 87 69 86 69 / 10 10 10 30
STUTTGART AR 88 70 86 70 / 10 10 20 20
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...64 / LONG TERM...59
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
325 AM CDT TUE MAY 28 2013
.SHORT TERM...TODAY THROUGH SUNDAY
REGIONAL RADAR OBSERVATIONS SHOW SOME DEVELOPING ISOLATED SHOWER
ACTIVITY STRETCHING FROM WEST OF FORT SMITH UP THROUGH HARRISON.
THE HRRR MODEL HAS A VERY GOOD HANDLE ON THIS AND SHOWS THIS
ACTIVITY CONTINUING TO DEVELOP/EXPAND AS IT MOVES EAST ACROSS THE
NORTHERN PARTS OF ARKANSAS. WENT AHEAD AND INCLUDED SOME SLIGHT
CHANCE POPS FOR SHOWERS THROUGH MIDDAY. OTHERWISE TODAY SHOULD BE
DRY. HIGH TEMPERATURES TODAY WILL BE SIMILAR TO YESTERDAY...IF NOT
A DEGREE WARMER IN HIGHER ELEVATIONS.
ALOFT...AN UPPER TROUGH IS BEGINNING TO TAKE SHAPE OUT WEST. THE
TROUGH AXIS WILL GRADUALLY SHIFT EAST THROUGH THE END OF THE WEEK.
IMPULSES EJECTING FROM THIS UPPER TROUGH WILL GENERATE CONVECTION
EAST OF A SURFACE LOW AND DRY LINE SETUP STRETCHING FROM THE HIGH
PLAINS OF COLORADO AND WESTERN KANSAS DOWN INTO THE PANHANDLE OF
TEXAS. AS THE UPPER TROUGH SHIFTS EAST...THESE IMPULSES AND THEIR
ASSOCIATED CONVECTION WILL DO THE SAME. SOME ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS MAY EXIST IN SE ARKANSAS TOMORROW
MORNING AS MOISTURE TRANSPORT STRENGTHENS...BUT BETTER RAIN
CHANCES WILL MOVE INTO WESTERN ARKANSAS WED EVENING AS ONE OF THE
AFOREMENTIONED IMPULSES MOVES THROUGH THE SOUTHERN PLAINS. EXPECT
THERE WILL BE SOME ONGOING CONVECTION PRESENT ACROSS MUCH OF THE
NWRN HALF OF THE STATE BY THURSDAY MORNING...WHICH IS WHEN THE
HIGHEST RAIN CHANCES OF THE SHORT TERM WILL EXIST. CLOUD COVER AND
RAIN COOLED AIR MAY DISRUPT DIURNAL THUNDERSTORM DEVELOPMENT THU
AFTERNOON...BUT GUIDANCE SHOWS ANOTHER SHORTWAVE AND ASSOC SURFACE
LOW MOVING EAST ACROSS OKLAHOMA THU NIGHT. THERE COULD BE SOME MCS
ACTIVITY MOVING THROUGH NW ARKANSAS AND SRN MISSOURI LATE THU
NIGHT AS A RESULT.
FRIDAY LOOKS TO BE DRY WITH ONLY AFTERNOON CU FOR CLOUD COVER.
TEMPERATURES WED THROUGH FRIDAY WILL BE SLIGHTLY BELOW NORMAL FOR
THE NORTHWEST HALF OF THE STATE BUT SHOULD BE CLOSE TO
CLIMATOLOGICAL NORMS FOR THE SOUTHEAST.
&&
.LONG TERM...SATURDAY THROUGH MONDAY
TO START THE EXTENDED...THE BROAD UPPER LOW PRESSURE TROUGH IS
EXPECTED TO SETTLE SE TO THE CENTRAL PLAINS...AS A SURFACE COLD
FRONT ALSO DRIFTS TO THE PLAINS. THE UPPER SW FLOW WILL BRING SHORT
WAVE ENERGY TO AR AND A CHANCE OF CONVECTION IS EXPECTED OVER ALL OF
AR. ADDITIONAL RAIN IS EXPECTED SATURDAY NIGHT AND SUNDAY...AS THE
COLD FRONT SAGS INTO AR AND ADDITIONAL UPPER ENERGY MOVES OVER AR.
AREAS OF HEAVY RAIN MAY BE POSSIBLE. SUNDAY NIGHT...THE COLD FRONT
GRADUALLY SAGS SOUTH TO NEAR THE AR AND LA STATE LINE...AS THE UPPER
TROUGH BOTTOMS OUT OVER THE TN VALLEY. ON MONDAY...DRIER AND A BIT
COOLER TEMPS ARE EXPECTED AS THE UPPER TROUGH MOVES EAST AND UPPER
RIDGING GRADUALLY MOVES INTO THE REGION. SOME UNCERTAINTY DOES EXIST
ON HOW FAR THE UPPER TROUGH TAKES THE COLD FRONT. IT IS THE END OF
MAY AND A BIT UNUSUALLY TO HAVE A COLD FRONT PUSH THIS FAR SOUTH.
TEMPERATURES WILL BE AROUND NORMAL VALUES...THEN COOL A BIT IF THE
AIR MASS FILTERS IN BEHIND THE FRONT.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 87 68 86 69 / 10 10 10 30
CAMDEN AR 88 69 87 70 / 10 10 20 20
HARRISON AR 84 67 83 67 / 10 10 20 40
HOT SPRINGS AR 86 69 85 70 / 10 10 20 30
LITTLE ROCK AR 88 70 87 70 / 10 10 10 30
MONTICELLO AR 89 70 86 70 / 10 10 20 20
MOUNT IDA AR 85 68 84 70 / 10 10 20 30
MOUNTAIN HOME AR 86 68 85 68 / 20 10 20 40
NEWPORT AR 88 69 86 70 / 10 10 10 30
PINE BLUFF AR 88 69 86 70 / 10 10 20 20
RUSSELLVILLE AR 87 69 85 69 / 10 10 20 30
SEARCY AR 87 69 86 69 / 10 10 10 30
STUTTGART AR 88 70 86 70 / 10 10 20 20
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...64 / LONG TERM...59
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1054 PM PDT MON MAY 27 2013
.DISCUSSION...AS OF 8:47 PM PDT MONDAY...IT WAS A COOL AND CLOUDY
MEMORIAL DAY FOR MOST OF THE DISTRICT AS A WEAK LATE SEASON COLD
FRONT MOVED THROUGH NORTHERN CALIFORNIA. RAIN TOTALS WERE SPOTTY
AND LIGHT WITH MOST SITES REPORTING FROM A TRACE TO A FEW
HUNDREDTHS. JUST SENT OUT A PUBLIC INFORMATION STATEMENT SHOWING
SOME OF THE TOTALS ACROSS THE DISTRICT INCLUDING SOME OF THE
REMOTE GAGES UP IN THE HILLS. LAST VISIBLE SATELLITE IMAGES STILL
SHOW PLENTY OF MOISTURE OFF SHORE AND VARIOUS AMSU/SSMI SATELLITE
SCANS SHOW TONGUE OF MOISTURE JUST SOUTH OF 40N...WITH TPW VALUES
WELL IN EXCESS OF 1 INCH. LATEST DOPPLER RADAR SCANS ARE STILL
SHOWING SOME ISOLATED SHOWERS MOVING ONSHORE IN ACCORDANCE WITH
SATELLITE IMAGERY...AND KSTS REPORTING -RA WITH LAST OBSERVATION.
INCOMING HIGH RESOLUTION RAP MODEL KEEPS SPITTING OUT SOME VERY
LIGHT QPF NUMBERS OVERNIGHT...MAINLY IN THE NORTH BAY AND ALONG
THE COAST. UPSHOT IS THAT CURRENT FORECAST KEEPS SOME SLIGHT
CHANCE OF SHOWERS GOING THROUGH THE OVERNIGHT AND SEE NO NEED TO
ALTER THAT FORECAST.
BACK TO WORK TUESDAY THE REGION WILL BE POST-FRONTAL WITH BREEZY
ONSHORE WINDS. HIGHS AGAIN WILL MAINLY BE IN THE 60S NEAR THE
COAST AND BAYS WITH ONLY LOW TO MID 70S FOR MOST INLAND LOCATIONS
WHICH IS ABOUT 5 DEGREES BELOW NORMAL FOR LATE MAY. EXPECTING MORE
SUNSHINE BY THE AFTERNOON HOURS COMPARED TO TODAY.
LATE TUESDAY NIGHT INTO WEDS ANOTHER SIMILAR LATE SEASON COLD
FRONT WILL APPROACH FAR NORTHERN CALIFORNIA. MODELS HAVE BEEN
FAIRLY CONSISTENT IN BRINGING THE RAIN/NO-RAIN LINE TO FAR
NORTHERN SONOMA COUNTY. FORECAST HAS THIS ACCOUNTED FOR AND ANY
RAIN THAT FALLS ON WEDS MORNING WILL BE LIGHT AND BRIEF AS THE
FRONT WILL QUICKLY MOVE INLAND DURING THE DAY WEDS. SO ONLY REAL
PRECIP THREAT FOR WEDS LOOKS TO BE NORTH OF SANTA ROSA WITH PARTLY
CLOUDY SKIES AND SEASONABLE TEMPS FOR THE REST OF THE REGION.
ZONAL FLOW WITH ONSHORE WINDS WILL CONTINUE ON THURSDAY BUT TEMPS
WILL NUDGE A FEW DEGREES WARMER TO RIGHT AROUND SEASONABLE NORMALS.
BIG WEATHER STORY FRIDAY AND INTO THE WEEKEND WILL THEN BE A NOTED
WARMING AND DRYING TREND. A STRONG RIDGE WILL DEVELOP OVER THE
STATE WITH UNSETTLED WEATHER EAST OF THE ROCKIES AMPLIFYING THE 500
MB PATTERN. A 590 DM HIGH OVER THE EASTERN PACIFIC AND ASSOCIATED
850 MB TEMPS OF AROUND 22 CELSIUS BY SATURDAY OVER THE BAY AREA.
SO EXPECT RAPID WARMING ON FRIDAY AND SATURDAY WITH MOSTLY CLEAR
SKIES...EVEN AT THE BEACHES AS THE THERMAL TROUGH STRADDLES THE
COAST WITH PERIODS OF LIGHT TO MODERATE NORTHERLY WINDS DEVELOPING
IN THE HILLS. ECMWF MOS DATA IS GETTING OMINOUSLY CLOSE TO SOME
WIDESPREAD TRIPLE DIGIT HEAT BY SATURDAY FOR THE INLAND VALLEYS OR
AT THE VERY LEAST LOTS OF 90S. SHOULD THE PATTERN DEVELOP AS
EXPECTED FIRE WEATHER CONCERNS WILL BECOME ELEVATED ESPECIALLY IN
LIGHT OF VERY DRY FUELS ACROSS THE REGION AND STATE.
MODELS SPIN UP A WEAK CIRCULATION BY SUNDAY WHICH WOULD LIKELY
INDUCE A SOUTHERLY WIND REVERSAL AND COASTAL COOLING...FOLLOWED BY
INLAND COOLING NEXT MONDAY.
&&
.AVIATION...AS OF 10:40 PM PDT MONDAY...MOIST FLOW OFF EPAC CONTINUES
SUPPORTED BY AREA DEWPOINT TEMPERATURES IN THE 50S...TOTAL PRECIPITABLE
WATERS OVER 1 INCH (200% OF NORMAL)...AND SATELLITE IMAGERY SHOWING
MORE CLOUDS SPILLING INTO THE REGION.
AREA RAIN GAUGES NOW SHOW UPWARDS OF 0.30 INCHES AT POINT REYES AND
0.17 INCHES AT THE SANTA ROSA RAWS...AND 0.02 INCHES IN SAN FRANCISCO.
KMUX RADAR SHOWS STEADY LIGHT RAIN CONTINUING TO SPREAD SOUTHEAST.
VICINITY OF KSFO...WET RUNWAYS AND LIGHT WINDS TONIGHT. IT`S A LOW
CONFIDENCE FORECAST SINCE THE MODELS ARE UNDERESTIMATING RAINFALL
AMOUNTS SO FAR. PARTIAL CLEARING PROBABLE TUE AFTERNOON WITH THE
SFO-SAC PRESSURE GRADIENT INCREASING TO 4 MB. GUSTY WEST WINDS
ARE POSSIBLE TUE AFTERNOON AND EVENING.
KSFO BRIDGE APPROACH...WET WEATHER TONIGHT. CIGS POSSIBLY LOWERING TO
MVFR.
MONTEREY BAY AREA TERMINALS...LOW CONFIDENCE. PLENTY OF MOIST AIR
ROLLING OFF THE OCEAN LEADING TO MVFR CIGS AND EVENTUALLY IFR CIGS.
LIGHT RAIN POSSIBLE OVERNIGHT.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM
&&
$$
PUBLIC FORECAST: RWW
AVIATION/MARINE: CANEPA
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.SANFRANCISCOBAYAREA.GOV
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS NEW YORK NY
808 PM EDT WED MAY 29 2013
.SYNOPSIS...
A WARM FRONT MOVES NORTH OF THE AREA TONIGHT. A BERMUDA HIGH
PRESSURE DOMINATES THE WEATHER THURSDAY THROUGH SATURDAY NIGHT.
A COLD FRONT APPROACHES SUNDAY AND MOVES THROUGH THE REGION
MONDAY. CANADIAN HIGH PRESSURE THEN BUILDS IN MONDAY NIGHT THROUGH
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
SEVERE THUNDERSTORM WATCH FOR ORANGE AND PUTNAM COUNTIES UNTIL
03Z.
LINE OF SHOWERS AND THUNDERSTORMS MOVING SOUTHEAST OVER SOUTHERN
NY AND NORTHEASTERN MA WILL MOST LIKELY MOVE INTO NORTHERN ZONES
TONIGHT...AFTER 01Z. THE HRRR LOOKED LIKE IT HAD THE BEST HANDLE
OF THE STORMS. THESE STORMS ARE STRONG TO SEVERE...AND WITH
1000-2000 J/KG OF CAPE SEEN IN LAPS IN ORANGE AND PUTNAM
COUNTIES...THERE STILL EXISTS THE POSSIBILITY THAT THIS LINE MAY
HOLD TOGETHER. IT WILL ALSO MAKE ITS WAY INTO CT...BUT WITH LESS
IN THE WAY OF CAPE...STORMS SHOULD WEAKEN AS THEY APPROACH THIS
REGION. HOWEVER...GUSTY WINDS...SMALL HAIL AND HEAVY RAIN ARE
STILL POSSIBILITIES...ALONG WITH AN ISOLATED SEVERE STORM.
THE WARM FRONT IS LIFTING NORTH ACROSS THE CWA THIS AFTERNOON. A
SHORTWAVE TROUGH IS ALSO APPROACHING FROM THE WEST AND WILL CROSS
THE REGION THIS EVENING. CLOUD COVER CONTINUES TO ERODE ALLOWING FOR
TEMPERATURES TO WARM AND INSTABILITY LEVELS TO INCREASE FAIRLY
RAPIDLY. LATEST SPC MESOANALYSIS INDICATES AROUND 1000 TO 1500 J/KG
OF MLCAPE FROM NE NJ AND THE LOWER HUDSON VALLEY. THERE IS VERY
LITTLE CONVECTIVE INHIBITION AND INSTABILITY MAY CONTINUE TO
INCREASE ACROSS THE AREA THE NEXT FEW HOURS WITH CONTINUED SURFACE
HEATING. THE SHORTWAVE IS BEGINNING TO TRIGGER SOME CONVECTION
ACROSS NW PA AND UPSTATE NY...SO THIS WILL NEED TO MONITORED AS IT
APPROACHES. PORTIONS OF THE AREA...MAINLY NORTH OF LONG ISLAND AND
NYC...REMAIN IN A SLIGHT RISK FOR SEVERE THUNDERSTORMS THROUGH THE
EVENING WITH THE MAIN THREAT DAMAGING WINDS AND HAIL. THIS IS
SUPPORTED BY SHEAR VALUES BETWEEN 30 AND 35 KT...MORE FAVORABLE FOR
MULTICELL CLUSTERS WITH WIND AND HAIL THREATS. THE STRONGEST
CONVECTION COULD BEGIN TO MOVE IN TO OUR NW COUNTIES AROUND 21Z
AND SHIFT EAST THROUGH 00Z.
INTENSITY OF THE STORMS SHOULD LOWER AS THEY MOVE EAST THIS EVENING
WITH LOSS OF DAYTIME HEATING...BUT CHANCE OF A FEW SHOWERS AND
STORMS CONTINUES THROUGH 03Z AS THE SHORTWAVE MOVES THROUGH.
OTHERWISE...SKY COVER SHOULD GENERALLY BE PARTLY CLOUDY THROUGH THE
REST OF THE EVENING.
WITH A WARM AIR MASS IN PLACE TONIGHT...TEMPERATURES WILL ONLY FALL
INTO THE 60S AND A MAV/MET BLEND ACCEPTED HERE. SOME PATCHY FOG IS
POSSIBLE TOWARDS DAYBREAK.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY/...
DEEP LAYERED RIDGING BEGINS TO TAKES HOLD THURSDAY WITH A BERMUDA
HIGH RIDGING INTO THE AREA. WEIGHTED HIGH TEMPERATURES MORE TOWARDS
MET GUIDANCE BUT DID BLEND IN THE MAV GUIDANCE. THIS YIELDS HIGHS IN
UPPER 80S AND LOWER 90S...WARMEST ACROSS THE NYC METRO. HEAT INDEX
VALUES ARE EXPECTED TO STAY BELOW ADVISORY CRITERIA.
MODEL GUIDANCE DOES INDICATE A WEAK SHORTWAVE GLANCING OUR NORTHERN
COUNTIES DURING THE TIME OF MAX HEATING. IT IS HERE WHERE A SLIGHT
CHANCE OF A SHOWER OR STORM EXISTS.
DEEP RIDGING CONTINUES THURSDAY NIGHT INTO FRIDAY. TEMPERATURES
THURSDAY NIGHT WILL BE AROUND TEN DEGREES ABOVE AVERAGE IN THE 60S
AND LOWER 70S IN THE CITY.
FOR FRIDAY...TEMPERATURES MAY BE A FEW DEGREES WARMER THAN THURSDAY
IN THE CITY...WITH HEAT INDEX VALUES TOUCHING 95 OR 96 FOR A FEW
HOURS. UPPER 80S AND LOWER 90S EXPECTED ELSEWHERE. CONTINUED TO
WEIGHT HIGH TEMPERATURES MORE TOWARDS MET GUIDANCE WITH A BLEND OF
MAV GUIDANCE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
FRIDAY NIGHT AND SATURDAY LEANED TOWARD A BLEND OF THE GFS AND ECMWF
WITH HIGH PRESSURE REMAINING OVER THE AREA. HOWEVER...WITH THE LOW
THAT WILL BE IMPACTING THE AREA SUNDAY INTO MONDAY THE NAM WAS A
LITTLE WEAKER THAN THE OTHER MODELS BOTH ALOFT AND AT THE SURFACE.
WITH SOME INSTABILITY AND WEAK FORCING POSSIBLE SATURDAY AFTERNOON
ACROSS ORANGE COUNTY...AS RIDGE AXIS SLIDES TO THE EAST OF THE
AREA...HAVE KEPT IN THE SLIGHT CHANCE POPS FOR THUNDERSTORMS.
THEN FOR THE PERIOD SATURDAY NIGHT THROUGH WEDNESDAY FORECAST
REMAINS CONSISTENT WITH CURRENT FORECAST...AND THE WPC/ECMWF
GUIDANCE. A COLD FRONT APPROACHES SUNDAY AND MOVES SLOWLY THROUGH
THE AREA THROUGH MONDAY EVENING. FOR SUNDAY NIGHT AND MONDAY HAVE
INCREASED POPS TO LIKELY WITH INCREASING CONFIDENCE IN MEASURABLE
PRECIPITATION. DEEP UPPER TROUGH COULD BE A LITTLE SLOWER TO MOVE
THROUGH AND PRECIPITATION MAY LINGER A LITTLE LONGER BEHIND THE COLD
FRONT MONDAY NIGHT.
TEMPERATURES THROUGH THE PERIOD WERE MAINLY A BLEND OF THE PREVIOUS
FORECAST AND ECMWF GUIDANCE.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
THE REGION WILL BE OF THE NORTHWEST PERIPHERY OF WESTERN ATLANTIC
HIGH PRESSURE THROUGH THE PERIOD.
MAINLY VFR THROUGH THE TAF PERIOD.
MAIN ACTIVITY WE ARE WATCHING IS A CONVECTIVE LINE OVER CENTRAL NY
THAT IS EXPECTED TO CONTINUE TO MOVE SE...WITH ADDITIONAL
DEVELOPMENT ON THE SW FLANK. THE LINE IS EXPECTED TO MAINTAIN ITS
STRENGTH OVER THE NEXT HOUR OR SO...AND THEN GRADUALLY WEAKEN WITH
THE LOSS OF DAYTIME INSTABILITY. EXPECTATION IS THAT THE WEAKENING
LINE WILL AFFECT KSWF...AND THEN LIKELY AFFECT KHPN/KBDR THIS
EVENING. SHOWER ACTIVITY WILL LIKELY MAINTAIN ITSELF INTO KGON AND
POSSIBLY CLIP KISP LATE THIS EVENING.
MVFR/IFR FOG IS POSSIBLE OUTSIDE OF NYC TERMINALS TONIGHT. BEST
CHANCE ALONG COAST AND TERMINALS AFFECTED BY RAIN.
VFR ON WED WITH WSW WINDS TO START THE DAY. WINDS GUST INTO MID
TEENS POSSIBLE ACROSS CITY AND INTERIOR TERMINALS IN THE
AFTERNOON. MODERATE CONFIDENCE IN AFT SEABREEZE AT
KJFK/KISP/KBDR/KGON. LOW CONFIDENCE THAT IT REACHES
KLGA/KHPN...AND NOT EXPECTED ELSEWHERE.
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: TSRA NOT EXPECTED THIS EVENING.
KJFK FCSTER COMMENTS: TSRA NOT EXPECTED THIS EVENING.
KLGA FCSTER COMMENTS: TSRA NOT EXPECTED THIS EVENING.
KTEB FCSTER COMMENTS: TSRA NOT EXPECTED THIS EVENING.
KHPN FCSTER COMMENTS: TSRA POSSIBLE BETWEEN 2Z AND 5Z.
KISP FCSTER COMMENTS: SHRA POSSIBLE BTWN 3Z TO 6Z...LOW PROB OF
TSRA.
.OUTLOOK FOR 00Z FRIDAY THROUGH MONDAY...
.THURSDAY NIGHT-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...
EXPECTING SCA CONDITIONS FROM HAZARDOUS SEAS OVER OCEAN WATERS
THROUGH THURSDAY EVENING SO EXTENDED CURRENT SCA FOR ANZ355 AND
ANZ353 THROUGH 18Z THURSDAY AND 22Z THURSDAY FOR ANZ350.
OTHERWISE...WILL SEE SUB-SCA CONDITIONS FROM THURSDAY NIGHT THROUGH
FRIDAY.
BERMUDA HIGH PRESSURE WILL REMAIN THROUGH SATURDAY NIGHT. THE HIGH
WILL SLOWLY MOVE EAST SUNDAY AS LOW PRESSURE MOVES INTO SOUTHEASTERN
CANADA AND A COLD FRONT APPROACHES FROM THE WEST. THE COLD FRONT
WILL CROSS THE FORECAST WATERS MONDAY INTO MONDAY EVENING. HIGH
PRESSURE BUILDS IN BEHIND THE FRONT MONDAY NIGHT INTO TUESDAY. WIND
AND GUSTS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT LEVELS FRIDAY
NIGHT THROUGH MONDAY NIGHT.
WITH AN INCREASING SOUTHWESTERLY FLOW SATURDAY INTO MONDAY SEAS ON
THE OCEAN WILL BUILD TO SMALL CRAFT LEVELS SATURDAY AND REMAIN
THROUGH MONDAY.
&&
.HYDROLOGY...
NO SIGNIFICANT PRECIPITATION IS EXPECTED TONIGHT THROUGH SUNDAY MORNING.
SUNDAY AFTERNOON THROUGH MONDAY EVENING ONE HALF TO ONE INCH OF
RAINFALL IS POSSIBLE...WITH LOCALLY HIGHER AMOUNTS IN HEAVIER
CONVECTION.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 2 PM EDT
THURSDAY FOR ANZ353-355.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT
THURSDAY FOR ANZ350.
&&
$$
SYNOPSIS...DS/MET
NEAR TERM...MPS/DS
SHORT TERM...MPS/DS
LONG TERM...MET
AVIATION...
MARINE...MPS/DS/MET
HYDROLOGY...MPS/DS/MET
AREA FORECAST DISCUSSION
NWS TAUNTON MA
409 PM EDT TUE MAY 28 2013
.SYNOPSIS...
RAIN WILL OVERSPREAD THE REGION INTO THE OVERNIGHT HOURS INTO
WEDNESDAY MORNING...WITH THE THUNDERSTORMS THEREAFTER INTO
WEDNESDAY NIGHT. SUMMER HEAT AND HUMIDITY WILL FOLLOW FOR
THURSDAY INTO SUNDAY. AN APPROACHING COLD FRONT FROM THE WEST
WILL BRING AN INCREASING THREAT OF SHOWERS AND THUNDERSTORMS
SUNDAY AFTERNOON INTO MONDAY WITH MORE SEASONABLE TEMPERATURES
EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
330 PM UPDATE...
THE HRRR IS DOING THE BEST IN HANDLING THE PRECIPITATION SHIELD
COLLOCATED WITH THE SURFACE WARM FRONT CENTERED AROUND THE NYC
TRI-STATE REGION. FOLLOWING ACCORDINGLY...THE EXPECTATION IS FOR
THE BATCH OF RAIN TO SLIDE SOUTH AND EAST UP AGAINST HIGH PRESSURE
AND DRIER AIR ACROSS THE ATLANTIC.
CHANCE TO LIKELY POPS SHOULD IMPACT MUCH OF CONNECTICUT NORTH INTO
SPRINGFIELD AND WORCESTER MASSACHUSETTS INTO THE EVENING COMMUTE.
RAIN LOOKS TO GET INTO RHODE ISLAND AROUND 8 PM. NO THUNDERSTORMS
ARE ANTICIPATED WITH THE BATCH OF RAIN. RAIN AMOUNTS UPSTREAM ARE
PRESENTLY LIGHT WITH HIGHEST VALUES WITHIN AN HOUR OF AROUND ONE-
TENTH.
TONIGHT...
REINVIGORATION OF PRECIPITATION ALONG THE APPROACHING WARM FRONT
WILL PROCEED INTO THE OVERNIGHT HOURS AS PRESENT ENERGY ACROSS
MICHIGAN PROPAGATES WITH THE MEAN-FLOW ALONG THE NOSE OF A H925-85
JET. THE BULK OF THE ACTIVITY REMAINS NORTH ACROSS CENTRAL AND
NORTHERN NEW ENGLAND UP INTO THE SAINT LAWRENCE VALLEY. MAINLY
RAIN...THERE IS ALSO THE POSSIBILITY FOR THUNDERSTORMS PARENT
WITH THE STRONGLY SHEARED PROFILE. BUT WITH LITTLE TO NO
INSTABILITY...THUNDERSTORMS SHOULD BE VERY ISOLATED. JUST A RUMBLE
OR TWO OF THUNDER. NO THREATS ARE PERCEIVED...BUT THERE COULD BE
POCKETS OF HEAVIER RAIN THAT COULD LEAD TO LOCALIZED URBAN
FLOODING WITH PONDING OF WATER.
ALONG THE SOUTH SHORE...HIGHER DEWPOINT AIR COULD BECOME DELAYED
ACROSS THE COLDER OCEAN WATERS. PRESENTLY OCEAN TEMPS HOVER AROUND
THE MID 50S. IT IS WHEN DEWPOINTS RISE A FEW DEGREES ABOVE SUCH
VALUES THAT THE LIKELIHOOD FOR COASTAL FOG DEVELOPMENT INCREASES.
FEEL THE BEST CHANCES WILL BE TOWARDS THE MORNING HOURS AS DIURNAL
COOLING MIXED WITH PROLONGED SOUTHERLY FETCH OF GREATER MOISTURE
WILL YIELD DEWPOINTS IN THE 60S ALONG THE SOUTH SHORE. PATCHY FOG
SUBSEQUENTLY MENTIONED.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
A MAJORITY OF THE FORECAST HINGES UPON THE EVOLUTION OF OVERNIGHT
RAINS PARENT WITH THE SURFACE WARM FRONT...WHETHER CLEARING
PROCEEDS TO ALLOW DESTABILIZATION OF THE LOCAL ENVIRONMENT AHEAD
OF A WEAK TROUGH AXIS AND ATTENDANT MID-LEVEL ENERGY ANTICIPATED
TO SWEEP THROUGH THE NORTHEASTERN CONUS DURING THE AFTERNOON INTO
EVENING HOURS.
THE MAIN KEY INGREDIENT TO THE POSSIBILITY OF CONVECTION IS SIMPLY
INSTABILITY. SHEAR IS NO QUESTION. 0-6 KM BULK SHEAR VALUES
CONTINUE TO BE ROBUST...WHILE HELICITY VALUES REMAIN NOTEWORTHY
TOWARDS SUPPORTING ROTATING UPDRAFTS. OF SOME CONCERN IS WHETHER
SURFACE WINDS CAN ENCOMPASS AN EASTERLY COMPONENT RESULTING IN A
GREATER TURNING OF THE WIND WITHIN THE HODOGRAPH PROFILE. ECHOING
THE SPC DAY 2 OUTLOOK...WHILE DAMAGING WINDS IS THE LIKELY THREAT
WITH THE SHEAR PROFILE...A POTENTIAL BRIEF SPIN-UP IS NOT OUT OF
THE QUESTION. BUT AGAIN THE POSSIBILITY HINGES ON SURFACE-BASED
INSTABILITY BUILDING AND DESTABILIZATION OF THE BOUNDARY LAYER
PROFILE.
FEEL THE NORTH AND EAST FORECAST AREA WILL REMAIN STABLE...SOCKED
IN BY CLOUDS AND COOLER TEMPERATURES. THUNDERSTORMS ARE NOT OUT OF
THE QUESTION BUT THE CHANCES FOR SEVERE LOOK TO BE LOW. WILL
SIMPLY GO WITH A MENTION OF THUNDERSTORMS.
SOUTH AND WEST IT IS ENTIRELY PLAUSIBLE THAT CLOUDS COULD BREAK
ALLOWING INSTABILITY TO BUILD UP TO 1000 TO 2000 J/KG OF CAPE...
FORCED BY THE APPROACHING TROUGH AXIS AND MID-LEVEL ENERGY. WHILE
THE BETTER CHANCES WILL BE ACROSS NY/PA...WITHIN THE CONNECTICUT
VALLEY IT IS POSSIBLE INTO THE AFTERNOON TOWARDS THE EVENING
HOURS TO SEE STORMS WITH SEVERE WEATHER THREATS OF DAMAGING
WINDS...SMALL HAIL...AND THE POSSIBILITY OF A BRIEF TORNADO.
GREATER CONFIDENCE LEANS TOWARDS DAMAGING WINDS AS THE FORECASTED
WIND PROFILE IS MORE UNI-DIRECTIONAL...AND THE BOUNDARY LAYER
EXHIBITS AN INVERTED-V PROFILE. FORECAST AMENDED ACCORDINGLY WITH
THE PERCEIVED THREATS. DOWNPOURS WILL ALSO BE ANTICIPATED WITH
THE VERY MOIST ATMOSPHERE POSSIBLY RESULTING IN URBAN FLOODING AND
PONDING OF WATER. THE EVENING COMMUTE AROUND THE HARTFORD-
SPRINGFIELD AREA MAY COME UNDER THREAT WITH POSSIBLE SEVERE
WEATHER.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
HIGHLIGHTS...
* HEAT WAVE LIKELY FOR PORTIONS OF SNE THU THROUGH SAT
* INCREASING THREAT OF SHOWERS/TSTMS SUN AFTN INTO MON
* MORE SEASONABLE TEMPS EARLY NEXT WEEK
OVERVIEW...
MODELS IN GOOD AGREEMENT SIGNALING SUMMER HEAT AND HUMIDITY FOR
THURSDAY THROUGH AT LEAST SATURDAY AS SE US RIDGE EXPANDS
NORTHWARD ALONG THE EASTERN SEABOARD. IT APPEARS THE RIDGE WILL
BEGIN TO BREAK DOWN SUNDAY INTO MONDAY AS GT LAKES TROF PUSHES
EAST WITH INCREASING THREAT OF SHOWERS/TSTMS...THEN COOLER TEMPS
FOR EARLY NEXT WEEK. THERE ARE DIFFERENCES BETWEEN GFS AND ECMWF
REGARDING HOW QUICKLY SHOWERS EXIT THE REGION NEXT TUE. ECMWF IS
MORE PROGRESSIVE AND DRIES IT OUT WHILE GFS AND ITS ENSEMBLE MEAN
KEEPS THE TROF AXIS TO THE WEST WITH CONTINUED CHC SHOWERS/TSTMS.
LOTS OF INHERENT UNCERTAINTY AT THIS TIME RANGE SO FORECAST WILL
LIKELY UNDERGO CHANGES WITH TIME.
THURSDAY THROUGH SATURDAY...
SUMMERTIME HEAT AND HUMIDITY WILL BE THE THEME DURING THIS PERIOD
AS MID LEVEL RIDGE BUILDS ACROSS THE REGION. 850 MB TEMPS INCREASE
TO 16-17C THU AND NEAR 18C FRI AND SAT. EXPECT MAX TEMPS TO REACH
UPPER 80S TO LOWER 90S DURING THIS PERIOD WITH SOME MID 90S
POSSIBLE FRI/SAT IN THE INTERIOR VALLEYS. COOLER ALONG THE
IMMEDIATE S COAST DUE TO SW COMPONENT TO THE WIND. A 3 DAY HEAT
WAVE IS LIKELY FOR MANY INTERIOR LOCATIONS. ATMOSPHERE WILL
DESTABILIZE EACH AFTERNOON SO CANT RULE OUT ISOLD TO WIDELY SCT
CONVECTION...BUT LIMITED FORCING WILL KEEP AREAL COVERAGE QUITE
LIMITED WITH DRY WEATHER MOST OF THE TIME.
SUNDAY INTO MONDAY...
AS RIDGE BEGINS TO BREAK DOWN...SLIGHTLY COOLER TEMPS ALOFT WILL
INCREASE THREAT OF SHOWERS/TSTMS. MAIN THREAT SUNDAY WILL BE IN
THE INTERIOR WITH FOCUS SHIFTING ACROSS REST OF SNE SUN NIGHT INTO
MONDAY AS THE COLD FRONT MOVES INTO THE REGION. STILL QUITE WARM
ON SUNDAY ALTHOUGH MORE CLOUDS AND SLIGHTLY COOLER 850 MB TEMPS
WILL PROBABLY KEEP TEMPS IN THE 80S...COOLING TO THE 70S MONDAY.
TUESDAY... LOTS OF UNCERTAINTY HERE WITH HOW QUICKLY THE FRONT
CLEARS THE AREA. WE LEANED TOWARD MORE PROGRESSIVE ECMWF SOLUTION
WITH MOSTLY DRY CONDITIONS...BUT A WETTER SCENARIO CANT BE RULED
OUT.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
NEAR-TERM /INTO WEDNESDAY NIGHT/...MODERATE CONFIDENCE.
SOUTHERLY FLOW TO PROCEED INTO THE EVENING ERODING DAYTIME SEA-
BREEZES. MVFR CIGS/VSBYS WILL BE POSSIBLE AS RAIN OVERSPREADS THE
REGION TONIGHT INTO WEDNESDAY MORNING. IFR COASTAL FOG WILL BE AN
ISSUE FOR THE SOUTH-COASTAL TERMINALS. INTO WEDNESDAY...SHRA/TSRA
ANTICIPATED...BUT SPECIFICITY IS INDETERMINATE. CONFIDENCE OF A
WIDESPREAD THREAT OF TEMPO MVFR/IFR IMPACTS...WITH A GREATER
SEVERE THREAT ACROSS THE CONNECTICUT RIVER VALLEY. ENERGY AND
TERMINAL IMPACTS CLEARING OUT INTO THURSDAY MORNING.
KBOS TERMINAL...MODERATE CONFIDENCE. SEA-BREEZE SHOULD ERODE OUT
INTO THE EVENING WITH WINDS BECOMING SOUTHERLY.
KBDL TERMINAL...MODERATE CONFIDENCE. SEVERE WEATHER IS POSSIBLE
DURING THE AFTERNOON INTO EVENING HOURS WEDNESDAY.
OUTLOOK...THURSDAY THROUGH SUNDAY...
MOSTLY VFR. ISOLATED AFTERNOON/EVENING TSTMS POSSIBLE WITH
GREATEST THREAT SUN AFTERNOON IN THE INTERIOR. PATCHY LATE
NIGHT/EARLY MORNING FOG POSSIBLE.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
NEAR-TERM /THROUGH WEDNESDAY NIGHT/...
CONTINUED SOUTHERLY FETCH ACROSS THE WATERS THROUGH THE PERIOD
WILL RESULT IN SEAS OF 5 TO 7 FEET ALONG THE OUTER WATERS.
PERSISTED WITH A GENERIC SMALL CRAFT ADVISORY AS WINDS COULD GUST
AS HIGH AS 25 KTS AT TIMES.
RAIN AND COASTAL FOG IS EXPECTED TO BE AN ISSUE TOWARDS WEDNESDAY
MORNING ALONG THE SOUTH AND SOUTHEAST WATERS. ZERO-VISIBILITIES
ARE POSSIBLE WITH FOG...BUT FOR NOW A CONSERVATIVE FORECAST IS
PRESENTED WITH VISIBILITIES DOWN TO 1-2 SM.
THUNDERSTORMS WILL BE AN ISSUE DURING THE LATER HALF OF THE DAY
WEDNESDAY INTO WEDNESDAY NIGHT. SOME OF THESE STORMS WILL HAVE THE
POTENTIAL OF PRODUCING STRONG AND GUSTY GALE-FORCE WINDS.
OUTLOOK...THURSDAY THROUGH SUNDAY...
PERSISTENT SW FLOW MOSTLY BELOW SCA BUT WIND GUSTS COULD REACH 25
KT BY SUN. INCREASING SWELL WILL BUILD SEAS TO AROUND 5 FT LATE
FRI INTO SAT...ESPECIALLY ON THE SOUTHERN EXPOSED WATERS...AND
POSSIBLY REACHING 7 FT BY SUN.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 AM WEDNESDAY TO 8 AM EDT THURSDAY
FOR ANZ235-237.
SMALL CRAFT ADVISORY FROM 8 AM WEDNESDAY TO 8 AM EDT THURSDAY
FOR ANZ250-254.
SMALL CRAFT ADVISORY FROM 2 AM WEDNESDAY TO 8 AM EDT THURSDAY
FOR ANZ255-256.
&&
$$
SYNOPSIS...KJC/SIPPRELL
NEAR TERM...SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...KJC
AVIATION...KJC/SIPPRELL
MARINE...KJC/SIPPRELL
AREA FORECAST DISCUSSION
NWS TAUNTON MA
345 PM EDT TUE MAY 28 2013
.SYNOPSIS...
RAIN WILL OVERSPREAD THE REGION INTO THE OVERNIGHT HOURS INTO
WEDNESDAY MORNING...WITH THE THUNDERSTORMS THEREAFTER INTO
WEDNESDAY NIGHT. SUMMERTIME SIZZLE THEN VISITS FOR THURSDAY
THROUGH SUNDAY ALONG WITH HIGHER HUMIDITY. A COLD FRONT SLIDES
ACROSS THE REGION EARLY NEXT WEEK BRINGING MORE SEASONABLE
TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
330 PM UPDATE...
THE HRRR IS DOING THE BEST IN HANDLING THE PRECIPITATION SHIELD
COLLOCATED WITH THE SURFACE WARM FRONT CENTERED AROUND THE NYC
TRI-STATE REGION. FOLLOWING ACCORDINGLY...THE EXPECTATION IS FOR
THE BATCH OF RAIN TO SLIDE SOUTH AND EAST UP AGAINST HIGH PRESSURE
AND DRIER AIR ACROSS THE ATLANTIC.
CHANCE TO LIKELY POPS SHOULD IMPACT MUCH OF CONNECTICUT NORTH INTO
SPRINGFIELD AND WOCESTER MASSACHUSETTS INTO THE EVENING COMMUTE.
RAIN LOOKS TO GET INTO RHODE ISLAND AROUND 8 PM. NO THUNDERSTORMS
ARE ANTICIPATED WITH THE BATCH OF RAIN. RAIN AMOUNTS UPSTREAM ARE
PRESENTLY LIGHT WITH HIGHEST VALUES WITHIN AN HOUR OF AROUND ONE-
TENTH.
TONIGHT...
REINVIGORATION OF PRECIPITATION ALONG THE APPROACHING WARM FRONT
WILL PROCEED INTO THE OVERNIGHT HOURS AS PRESENT ENERGY ACROSS
MICHIGAN PROPAGATES WITH THE MEAN-FLOW ALONG THE NOSE OF A H925-85
JET. THE BULK OF THE ACTIVITY REMAINS NORTH ACROSS CENTRAL AND
NORTHERN NEW ENGLAND UP INTO THE SAINT LAWRENCE VALLEY. MAINLY
RAIN...THERE IS ALSO THE POSSIBILITY FOR THUNDERSTORMS PARENT
WITH THE STRONGLY SHEARED PROFILE. BUT WITH LITTLE TO NO
INSTABILITY...THUNDERSTORMS SHOULD BE VERY ISOLATED. JUST A RUMBLE
OR TWO OF THUNDER. NO THREATS ARE PERCEIVED...BUT THERE COULD BE
POCKETS OF HEAVIER RAIN THAT COULD LEAD TO LOCALIZED URBAN
FLOODING WITH PONDING OF WATER.
ALONG THE SOUTH SHORE...HIGHER DEWPOINT AIR COULD BECOME DELAYED
ACROSS THE COLDER OCEAN WATERS. PRESENTLY OCEAN TEMPS HOVER AROUND
THE MID 50S. IT IS WHEN DEWPOINTS RISE A FEW DEGREES ABOVE SUCH
VALUES THAT THE LIKELIHOOD FOR COASTAL FOG DEVELOPMENT INCREASES.
FEEL THE BEST CHANCES WILL BE TOWARDS THE MORNING HOURS AS DIURNAL
COOLING MIXED WITH PROLONGED SOUTHERLY FETCH OF GREATER MOISTURE
WILL YIELD DEWPOINTS IN THE 60S ALONG THE SOUTH SHORE. PATCHY FOG
SUBSEQUENTLY MENTIONED.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
A MAJORITY OF THE FORECAST HINGES UPON THE EVOLUTION OF OVERNIGHT
RAINS PARENT WITH THE SURFACE WARM FRONT...WHETHER CLEARING
PROCEEDS TO ALLOW DESTABILIZATION OF THE LOCAL ENVIRONMENT AHEAD
OF A WEAK TROUGH AXIS AND ATTENDANT MID-LEVEL ENERGY ANTICIPATED
TO SWEEP THROUGH THE NORTHEASTERN CONUS DURING THE AFTERNOON INTO
EVENING HOURS.
THE MAIN KEY INGREDIENT TO THE POSSIBILITY OF CONVECTION IS SIMPLY
INSTABILITY. SHEAR IS NO QUESTION. 0-6 KM BULK SHEAR VALUES
CONTINUE TO BE ROBUST...WHILE HELICITY VALUES REMAIN NOTEWORTHY
TOWARDS SUPPORTING ROTATING UPDRAFTS. OF SOME CONCERN IS WHETHER
SURFACE WINDS CAN ENCOMPASS AN EASTERLY COMPONENT RESULTING IN A
GREATER TURNING OF THE WIND WITHIN THE HODOGRAPH PROFILE. ECHOING
THE SPC DAY 2 OUTLOOK...WHILE DAMAGING WINDS IS THE LIKELY THREAT
WITH THE SHEAR PROFILE...A POTENTIAL BRIEF SPIN-UP IS NOT OUT OF
THE QUESTION. BUT AGAIN THE POSSIBILITY HINGES ON SURFACE-BASED
INSTABILITY BUILDING AND DESTABILIZATION OF THE BOUNDARY LAYER
PROFILE.
FEEL THE NORTH AND EAST FORECAST AREA WILL REMAIN STABLE...SOCKED
IN BY CLOUDS AND COOLER TEMPERATURES. THUNDERSTORMS ARE NOT OUT OF
THE QUESTION BUT THE CHANCES FOR SEVERE LOOK TO BE LOW. WILL
SIMPLY GO WITH A MENTION OF THUNDERSTORMS.
SOUTH AND WEST IT IS ENTIRELY PLAUSIBLE THAT CLOUDS COULD BREAK
ALLOWING INSTABILITY TO BUILD UP TO 1000 TO 2000 J/KG OF CAPE...
FORCED BY THE APPROACHING TROUGH AXIS AND MID-LEVEL ENERGY. WHILE
THE BETTER CHANCES WILL BE ACROSS NY/PA...WITHIN THE CONNECTICUT
VALLEY IT IS POSSIBLE INTO THE AFTERNOON TOWARDS THE EVENING
HOURS TO SEE STORMS WITH SEVERE WEATHER THREATS OF DAMAGING
WINDS...SMALL HAIL...AND THE POSSIBILITY OF A BRIEF TORNADO.
GREATER CONFIDENCE LEANS TOWARDS DAMAGING WINDS AS THE FORECASTED
WIND PROFILE IS MORE UNI-DIRECTIONAL...AND THE BOUNDARY LAYER
EXHIBITS AN INVERTED-V PROFILE. FORECAST AMENDED ACCORDINGLY WITH
THE PERCEIVED THREATS. DOWNPOURS WILL ALSO BE ANTICIPATED WITH
THE VERY MOIST ATMOSPHERE POSSIBLY RESULTING IN URBAN FLOODING AND
PONDING OF WATER. THE EVENING COMMUTE AROUND THE HARTFORD-
SPRINGFIELD AREA MAY COME UNDER THREAT WITH POSSIBLE SEVERE
WEATHER.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
BIG PICTURE...
GULF OF ALASKA LOW DIGS OVER THE PAC NORTHWEST AND ROCKIES...WHICH
INDUCES THE EASTERN UPPER RIDGE TO BUILD THROUGH SATURDAY. THIS
LEAVES A CLEAR PATH FOR THE WARM HUMID AIR IN THE NATION/S
MIDSECTION TO MOVE NORTHEAST INTO NEW ENGLAND. THE TROUGH OVER THE
ROCKIES WILL MOVE INTO THE PLAINS OVER THE WEEKEND. MODELS AGREE
ON THE UPPER RIDGE SHIFTING OVER THE OCEAN EARLY NEXT
WEEK...MAKING ROOM FOR THE SHORTWAVE AND ITS SUPPORTING UPPER JET
TO MOVE INTO THE NORTHEAST USA.
MODEL PREFERENCES...
UPPER CONTOUR FIELDS ARE SIMILAR FOR MOST OF THE PERIOD. THE
ECMWF IS A LITTLE SHARPER WITH THE SHORTWAVE TROUGH EARLY NEXT
WEEK. PREFER A BLEND OF HPC/GMOS AND ECMWF/GFS DATA.
THE DAILIES...
WEDNESDAY NIGHT...
UPPER SHORTWAVE RACES ACROSS NEW ENGLAND PUSHING A WARM FRONT
THROUGH THE REGION. ACTUALLY...THERE IS ALSO A COLD FRONT HIDDEN
IN THE MODEL FIELDS...BUT ONE SO WEAK THAT ITS EFFECTS COULD BE
OVERLOOKED. TEMPS ALOFT CONTINUE TO RISE OVERNIGHT. SUFFICIENT
MOISTURE ALOFT AND TOTALS 45-50...SO SHOWERS/TSTMS ARE REASONABLE.
TEMPS ARE A BLEND OF MOS.
THURSDAY THROUGH SUNDAY...
UPPER RIDGE BUILDS OVER THE REGION FOR THE LATE WEEK. TEMPS ALOFT
UNDER THIS RIDGE ALSO BUILD WITH TEMPS AT THE TOP OF THE MIXED
LAYER EQUIVALENT TO 17-18C AT 850 MB ESPECIALLY ON FRIDAY-
SATURDAY. MEANWHILE THE PRESSURE GRADIENT SUPPORTS A SOUTHWEST
WIND AND LOOKS TOO STRONG FOR AN EAST COAST SEABREEZE. THIS
SUPPORTS MAX TEMPS 85-95 WITH THE WARMEST MAX TEMPS FRIDAY-
SATURDAY. DEWPOINTS INCREASE INTO THE 60S WHICH IS SUPPORTED BY
OBSERVED DEWPOINTS OVER THE SOUTHERN PLAINS AND LOWER MISS RIVER
VALLEY...HIGHER VALUES ARE ONLY ALONG THE TEXAS GULF COAST. THIS
WILL GIVE US A TASTE OF SUMMER HUMIDITY AND KEEP MIN TEMPS IN THE
60S.
CONVECTION WILL BE A QUESTION THROUGH THE PERIOD. THE UPPER HIGH
AND SUBSIDENT FLOW WILL WORK AGAINST ANY STORMS FORMING. BUT
STABILITY PARAMETERS WILL REMAIN FAVORABLE...TOTALS HOLD AT 47 TO
50 PER ECMWF. SO CONVECTION IS POSSIBLE ANY OF THESE DAYS...BUT
WITH LOW LIKELIHOOD THURSDAY AND FRIDAY. BEST CHANCE WILL BE
SATURDAY AND SUNDAY IN THE CT VALLEY AND BERKSHIRE EAST
SLOPE...BUT WITH A CHANCE LATER IN THE DAY FARTHER EAST.
MONDAY...
UPPER TROUGH FROM THE WEST COAST MOVES OVER NEW ENGLAND EARLY
NEXT WEEK. THIS WILL PUSH A COLD FRONT THROUGH THE REGION. THE
UPPER JET MOVING THROUGH THE TROUGH WILL PRESENT A RIGHT ENTRANCE
REGION OVER OUR AREA WHICH WILL ENHANCE LIFT OVER THE HUMID
UNSTABLE AIRMASS. SO SHOWERS/TSTMS ARE POSSIBLE.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
NEAR-TERM /INTO WEDNESDAY NIGHT/...MODERATE CONFIDENCE.
SOUTHERLY FLOW TO PROCEED INTO THE EVENING ERODING DAYTIME SEA-
BREEZES. MVFR CIGS/VSBYS WILL BE POSSIBLE AS RAIN OVERSPREADS THE
REGION TONIGHT INTO WEDNESDAY MORNING. IFR COASTAL FOG WILL BE AN
ISSUE FOR THE SOUTH-COASTAL TERMINALS. INTO WEDNESDAY...SHRA/TSRA
ANTICIPATED...BUT SPECIFICITY IS INDETERMINATE. CONFIDENCE OF A
WIDESPREAD THREAT OF TEMPO MVFR/IFR IMPACTS...WITH A GREATER
SEVERE THREAT ACROSS THE CONNECTICUT RIVER VALLEY. ENERGY AND
TERMINAL IMPACTS CLEARING OUT INTO THURSDAY MORNING.
KBOS TERMINAL...MODERATE CONFIDENCE. SEA-BREEZE SHOULD ERODE OUT
INTO THE EVENING WITH WINDS BECOMING SOUTHERLY.
KBDL TERMINAL...MODERATE CONFIDENCE. SEVERE WEATHER IS POSSIBLE
DURING THE AFTERNOON INTO EVENING HOURS WEDNESDAY.
OUTLOOK...THURSDAY THROUGH SATURDAY...
THURSDAY THROUGH SATURDAY...
MOSTLY VFR. ISOLATED TSTMS POSSIBLE THURSDAY ESPECIALLY VICINITY
OF THE CT VALLEY. BETTER CHANCE OF BRIEF MVFR/IFR IN TSTMS ON
SATURDAY.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
NEAR-TERM /THROUGH WEDNESDAY NIGHT/...
CONTINUED SOUTHERLY FETCH ACROSS THE WATERS THROUGH THE PERIOD
WILL RESULT IN SEAS OF 5 TO 7 FEET ALONG THE OUTER WATERS.
PERSISTED WITH A GENERIC SMALL CRAFT ADVISORY AS WINDS COULD GUST
AS HIGH AS 25 KTS AT TIMES.
RAIN AND COASTAL FOG IS EXPECTED TO BE AN ISSUE TOWARDS WEDNESDAY
MORNING ALONG THE SOUTH AND SOUTHEAST WATERS. ZERO-VISIBILITIES
ARE POSSIBLE WITH FOG...BUT FOR NOW A CONSERVATIVE FORECAST IS
PRESENTED WITH VISIBILITIES DOWN TO 1-2 SM.
THUNDERSTORMS WILL BE AN ISSUE DURING THE LATER HALF OF THE DAY
WEDNESDAY INTO WEDNESDAY NIGHT. SOME OF THESE STORMS WILL HAVE THE
POTENTIAL OF PRODUCING STRONG AND GUSTY GALE-FORCE WINDS.
OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY...
WEST TO SOUTHWEST WIND REMAINS BELOW 25 KNOTS THROUGH THE PERIOD.
BUT THE WIND WILL BUILD SEAS OF 5-7 FEET ESPECIALLY ON THE
SOUTHERN EXPOSED WATERS. A LENGTHY SMALL CRAFT ADVISORY WILL BE
NEEDED FOR THESE SEAS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 AM WEDNESDAY TO 8 AM EDT THURSDAY
FOR ANZ235-237.
SMALL CRAFT ADVISORY FROM 8 AM WEDNESDAY TO 8 AM EDT THURSDAY
FOR ANZ250-254.
SMALL CRAFT ADVISORY FROM 2 AM WEDNESDAY TO 8 AM EDT THURSDAY
FOR ANZ255-256.
&&
$$
SYNOPSIS...DOODY/SIPPRELL
NEAR TERM...SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...WTB
AVIATION...WTB/SIPPRELL
MARINE...WTB/SIPPRELL
AREA FORECAST DISCUSSION
NWS TAUNTON MA
323 PM EDT TUE MAY 28 2013
.SYNOPSIS...
RAIN WILL OVERSPREAD THE REGION INTO THE OVERNIGHT HOURS
CONTINUING INTO WEDNESDAY MORNING...WITH THE THUNDERSTORMS
THEREAFTER INTO WEDNESDAY NIGHT. SUMMERTIME SIZZLE THEN VISITS FOR
THURSDAY THROUGH SUNDAY ALONG WITH HIGHER HUMIDITY. A COLD FRONT
SLIDES ACROSS THE REGION EARLY NEXT WEEK BRINGING MORE SEASONABLE
TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
330 PM UPDATE...
THE HRRR IS DOING THE BEST IN HANDLING THE PRECIPITATION SHIELD
COLLOCATED WITH THE SURFACE WARM FRONT CENTERED AROUND THE NYC
TRI-STATE REGION. FOLLOWING ACCORDINGLY...THE EXPECTATION IS FOR
THE BATCH OF RAIN TO SLIDE SOUTH AND EAST UP AGAINST HIGH PRESSURE
AND DRIER AIR ACROSS THE ATLANTIC.
CHANCE TO LIKELY POPS SHOULD IMPACT MUCH OF CONNECTICUT NORTH INTO
SPRINGFIELD AND WOCESTER MASSACHUSETTS INTO THE EVENING COMMUTE.
RAIN LOOKS TO GET INTO RHODE ISLAND AROUND 8 PM. NO THUNDERSTORMS
ARE ANTICIPATED WITH THE BATCH OF RAIN. RAIN AMOUNTS UPSTREAM ARE
PRESENTLY LIGHT WITH HIGHEST VALUES WITHIN AN HOUR OF AROUND ONE-
TENTH.
TONIGHT...
REINVIGORATION OF PRECIPITATION ALONG THE APPROACHING WARM FRONT
WILL PROCEED INTO THE OVERNIGHT HOURS AS PRESENT ENERGY ACROSS
MICHIGAN PROPAGATES WITH THE MEAN-FLOW ALONG THE NOSE OF A H925-85
JET. THE BULK OF THE ACTIVITY REMAINS NORTH ACROSS CENTRAL AND
NORTHERN NEW ENGLAND UP INTO THE SAINT LAWRENCE VALLEY. MAINLY
RAIN...THERE IS ALSO THE POSSIBILITY FOR THUNDERSTORMS PARENT
WITH THE STRONGLY SHEARED PROFILE. BUT WITH LITTLE TO NO
INSTABILITY...THUNDERSTORMS SHOULD BE VERY ISOLATED. JUST A RUMBLE
OR TWO OF THUNDER. NO THREATS ARE PERCEIVED...BUT THERE COULD BE
POCKETS OF HEAVIER RAIN THAT COULD LEAD TO LOCALIZED URBAN
FLOODING WITH PONDING OF WATER.
ALONG THE SOUTH SHORE...HIGHER DEWPOINT AIR COULD BECOME DELAYED
ACROSS THE COLDER OCEAN WATERS. PRESENTLY OCEAN TEMPS HOVER AROUND
THE MID 50S. IT IS WHEN DEWPOINTS RISE A FEW DEGREES ABOVE SUCH
VALUES THAT THE LIKELIHOOD FOR COASTAL FOG DEVELOPMENT INCREASES.
FEEL THE BEST CHANCES WILL BE TOWARDS THE MORNING HOURS AS DIURNAL
COOLING MIXED WITH PROLONGED SOUTHERLY FETCH OF GREATER MOISTURE
WILL YIELD DEWPOINTS IN THE 60S ALONG THE SOUTH SHORE. PATCHY FOG
SUBSEQUENTLY MENTIONED.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
A MAJORITY OF THE FORECAST HINGES UPON THE EVOLUTION OF OVERNIGHT
RAINS PARENT WITH THE SURFACE WARM FRONT...WHETHER CLEARING
PROCEEDS TO ALLOW DESTABILIZATION OF THE LOCAL ENVIRONMENT AHEAD
OF A WEAK TROUGH AXIS AND ATTENDANT MID-LEVEL ENERGY ANTICIPATED
TO SWEEP THROUGH THE NORTHEASTERN CONUS DURING THE AFTERNOON INTO
EVENING HOURS.
THE MAIN KEY INGREDIENT TO THE POSSIBILITY OF CONVECTION IS SIMPLY
INSTABILITY. SHEAR IS NO QUESTION. 0-6 KM BULK SHEAR VALUES
CONTINUE TO BE ROBUST...WHILE HELICITY VALUES REMAIN NOTEWORTHY
TOWARDS SUPPORTING ROTATING UPDRAFTS. OF SOME CONCERN IS WHETHER
SURFACE WINDS CAN ENCOMPASS AN EASTERLY COMPONENT RESULTING IN A
GREATER TURNING OF THE WIND WITHIN THE HODOGRAPH PROFILE. ECHOING
THE SPC DAY 2 OUTLOOK...WHILE DAMAGING WINDS IS THE LIKELY THREAT
WITH THE SHEAR PROFILE...A POTENTIAL BRIEF SPIN-UP IS NOT OUT OF
THE QUESTION. BUT AGAIN THE POSSIBILITY HINGES ON SURFACE-BASED
INSTABILITY BUILDING AND DESTABILIZATION OF THE BOUNDARY LAYER
PROFILE.
FEEL THE NORTH AND EAST FORECAST AREA WILL REMAIN STABLE...SOCKED
IN BY CLOUDS AND COOLER TEMPERATURES. THUNDERSTORMS ARE NOT OUT OF
THE QUESTION BUT THE CHANCES FOR SEVERE LOOK TO BE LOW. WILL
SIMPLY GO WITH A MENTION OF THUNDERSTORMS.
SOUTH AND WEST IT IS ENTIRELY PLAUSIBLE THAT CLOUDS COULD BREAK
ALLOWING INSTABILITY TO BUILD UP TO 1000 TO 2000 J/KG OF CAPE...
FORCED BY THE APPROACHING TROUGH AXIS AND MID-LEVEL ENERGY. WHILE
THE BETTER CHANCES WILL BE ACROSS NY/PA...WITHIN THE CONNECTICUT
VALLEY IT IS POSSIBLE INTO THE AFTERNOON TOWARDS THE EVENING
HOURS TO SEE STORMS WITH SEVERE WEATHER THREATS OF DAMAGING
WINDS...SMALL HAIL...AND THE POSSIBILITY OF A BRIEF TORNADO.
GREATER CONFIDENCE LEANS TOWARDS DAMAGING WINDS AS THE FORECASTED
WIND PROFILE IS MORE UNI-DIRECTIONAL...AND THE BOUNDARY LAYER
EXHIBITS AN INVERTED-V PROFILE. DOWNPOURS WILL ALSO BE ANTICIPATED
WITH THE VERY MOIST ATMOSPHERE POSSIBLY RESULTING IN URBAN
FLOODING AND PONDING OF WATER. THE EVENING COMMUTE AROUND THE
HARTFORD-SPRINGFIELD AREA MAY COME UNDER THREAT WITH POSSIBLE
SEVERE WEATHER.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
BIG PICTURE...
GULF OF ALASKA LOW DIGS OVER THE PAC NORTHWEST AND ROCKIES...WHICH
INDUCES THE EASTERN UPPER RIDGE TO BUILD THROUGH SATURDAY. THIS
LEAVES A CLEAR PATH FOR THE WARM HUMID AIR IN THE NATION/S
MIDSECTION TO MOVE NORTHEAST INTO NEW ENGLAND. THE TROUGH OVER THE
ROCKIES WILL MOVE INTO THE PLAINS OVER THE WEEKEND. MODELS AGREE
ON THE UPPER RIDGE SHIFTING OVER THE OCEAN EARLY NEXT
WEEK...MAKING ROOM FOR THE SHORTWAVE AND ITS SUPPORTING UPPER JET
TO MOVE INTO THE NORTHEAST USA.
MODEL PREFERENCES...
UPPER CONTOUR FIELDS ARE SIMILAR FOR MOST OF THE PERIOD. THE
ECMWF IS A LITTLE SHARPER WITH THE SHORTWAVE TROUGH EARLY NEXT
WEEK. PREFER A BLEND OF HPC/GMOS AND ECMWF/GFS DATA.
THE DAILIES...
WEDNESDAY NIGHT...
UPPER SHORTWAVE RACES ACROSS NEW ENGLAND PUSHING A WARM FRONT
THROUGH THE REGION. ACTUALLY...THERE IS ALSO A COLD FRONT HIDDEN
IN THE MODEL FIELDS...BUT ONE SO WEAK THAT ITS EFFECTS COULD BE
OVERLOOKED. TEMPS ALOFT CONTINUE TO RISE OVERNIGHT. SUFFICIENT
MOISTURE ALOFT AND TOTALS 45-50...SO SHOWERS/TSTMS ARE REASONABLE.
TEMPS ARE A BLEND OF MOS.
THURSDAY THROUGH SUNDAY...
UPPER RIDGE BUILDS OVER THE REGION FOR THE LATE WEEK. TEMPS ALOFT
UNDER THIS RIDGE ALSO BUILD WITH TEMPS AT THE TOP OF THE MIXED
LAYER EQUIVALENT TO 17-18C AT 850 MB ESPECIALLY ON FRIDAY-
SATURDAY. MEANWHILE THE PRESSURE GRADIENT SUPPORTS A SOUTHWEST
WIND AND LOOKS TOO STRONG FOR AN EAST COAST SEABREEZE. THIS
SUPPORTS MAX TEMPS 85-95 WITH THE WARMEST MAX TEMPS FRIDAY-
SATURDAY. DEWPOINTS INCREASE INTO THE 60S WHICH IS SUPPORTED BY
OBSERVED DEWPOINTS OVER THE SOUTHERN PLAINS AND LOWER MISS RIVER
VALLEY...HIGHER VALUES ARE ONLY ALONG THE TEXAS GULF COAST. THIS
WILL GIVE US A TASTE OF SUMMER HUMIDITY AND KEEP MIN TEMPS IN THE
60S.
CONVECTION WILL BE A QUESTION THROUGH THE PERIOD. THE UPPER HIGH
AND SUBSIDENT FLOW WILL WORK AGAINST ANY STORMS FORMING. BUT
STABILITY PARAMETERS WILL REMAIN FAVORABLE...TOTALS HOLD AT 47 TO
50 PER ECMWF. SO CONVECTION IS POSSIBLE ANY OF THESE DAYS...BUT
WITH LOW LIKELIHOOD THURSDAY AND FRIDAY. BEST CHANCE WILL BE
SATURDAY AND SUNDAY IN THE CT VALLEY AND BERKSHIRE EAST
SLOPE...BUT WITH A CHANCE LATER IN THE DAY FARTHER EAST.
MONDAY...
UPPER TROUGH FROM THE WEST COAST MOVES OVER NEW ENGLAND EARLY
NEXT WEEK. THIS WILL PUSH A COLD FRONT THROUGH THE REGION. THE
UPPER JET MOVING THROUGH THE TROUGH WILL PRESENT A RIGHT ENTRANCE
REGION OVER OUR AREA WHICH WILL ENHANCE LIFT OVER THE HUMID
UNSTABLE AIRMASS. SO SHOWERS/TSTMS ARE POSSIBLE.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
NEAR-TERM /INTO WEDNESDAY NIGHT/...MODERATE CONFIDENCE.
SOUTHERLY FLOW TO PROCEED INTO THE EVENING ERODING DAYTIME SEA-
BREEZES. MVFR CIGS/VSBYS WILL BE POSSIBLE AS RAIN OVERSPREADS THE
REGION TONIGHT INTO WEDNESDAY MORNING. IFR COASTAL FOG WILL BE AN
ISSUE FOR THE SOUTH-COASTAL TERMINALS. INTO WEDNESDAY...SHRA/TSRA
ANTICIPATED...BUT SPECIFICITY IS INDETERMINATE. CONFIDENCE OF A
WIDESPREAD THREAT OF TEMPO MVFR/IFR IMPACTS...WITH A GREATER
SEVERE THREAT ACROSS THE CONNECTICUT RIVER VALLEY. ENERGY AND
TERMINAL IMPACTS CLEARING OUT INTO THURSDAY MORNING.
KBOS TERMINAL...MODERATE CONFIDENCE. SEA-BREEZE SHOULD ERODE OUT
INTO THE EVENING WITH WINDS BECOMING SOUTHERLY.
KBDL TERMINAL...MODERATE CONFIDENCE. SEVERE WEATHER IS POSSIBLE
DURING THE AFTERNOON INTO EVENING HOURS WEDNESDAY.
OUTLOOK...THURSDAY THROUGH SATURDAY...
THURSDAY THROUGH SATURDAY...
MOSTLY VFR. ISOLATED TSTMS POSSIBLE THURSDAY ESPECIALLY VICINITY
OF THE CT VALLEY. BETTER CHANCE OF BRIEF MVFR/IFR IN TSTMS ON
SATURDAY.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
MODERATE CONFIDENCE THROUGH THE PERIOD.
MAINLY QUIET BOATING WEATHER CONTINUES TODAY. HOWEVER TONIGHT...
EXPECT A WARM FRONT TO ALLOW SOUTHERLY WINDS TO GRADUALLY INCREASE
ALONG WITH SEAS INTO THE DAY WED. SEAS WILL LIKELY REACH 5-6 FT
EARLY WED MORNING FIRST ON SRN WATERS...THEN ERN WATERS DURING THE
DAY WED. WIND GUSTS NEAR 25 KT POSSIBLE AT TIMES WED AS WELL.
THEREFORE...WILL ISSUE SMALL CRAFT ADVISORIES FOR EARLY MORNING
WED INTO THE DAY WED...PRIMARILY ON OCEAN WATERS.
OTHERWISE...SOME SHOWERS AND FOG MAY LEAD TO REDUCTION IN
VISIBILITY OVERNIGHT TONIGHT. ON WED...THERE IS A THREAT FOR
THUNDERSTORMS...WHICH MAY HAVE SOME STRONG WINDS AND SMALL HAIL
PARTICULARLY DURING THE AFTERNOON HOURS.
OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY...
WEST TO SOUTHWEST WIND REMAINS BELOW 25 KNOTS THROUGH THE PERIOD.
BUT THE WIND WILL BUILD SEAS OF 5-7 FEET ESPECIALLY ON THE
SOUTHERN EXPOSED WATERS. A LENGTHY SMALL CRAFT ADVISORY WILL BE
NEEDED FOR THESE SEAS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 AM TO 8 PM EDT WEDNESDAY FOR
ANZ235-237-255-256.
SMALL CRAFT ADVISORY FROM 8 AM TO 8 PM EDT WEDNESDAY FOR
ANZ250-254.
&&
$$
SYNOPSIS...WTB/SIPPRELL
NEAR TERM...SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...WTB
AVIATION...WTB/SIPPRELL
MARINE...WTB/DOODY
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1019 AM EDT TUE MAY 28 2013
.SYNOPSIS...
MAINLY DRY WEATHER TODAY AS HIGH PRESSURE EXITS TO THE EAST. A
WARM FRONT WILL LIFT THROUGH THE AREA TONIGHT BRINGING SOME
SHOWERS OVERNIGHT...AND WITH THUNDERSTORMS POSSIBLE WEDNESDAY.
SUMMERTIME SIZZLE THEN VISITS FOR THURSDAY THROUGH SUNDAY ALONG
WITH HIGHER HUMIDITY. A COLD FRONT SLIDES ACROSS THE REGION EARLY
NEXT WEEK BRINGING MORE SEASONABLE TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1030 AM UPDATE...
DID NOT GO AHEAD WITH ANY CHANGES TO THE NEAR-TERM FORECAST. WILL
AWAIT 28.12Z FORECAST GUIDANCE BEFORE MAKING ANY CHANGES. INITIAL
GLANCE...PRESENT PRECIPITATION SHIELD ACROSS NY/PA/NJ IS MOVING
SLIGHTLY FASTER THAN 0Z/6Z FORECAST GUIDANCE CURRENTLY PROJECTS.
IN ADDITION...HIGH PRESSURE REMAINS IN CONTROL OF THE REGIONS
WEATHER. THE EXPECTATION IS FOR THE PRECIPITATION SHIELD TO MOVE
INTO THE REGION SLIGHTLY FASTER...BUT ERODE WITH THE COMBINATION
OF SUBSIDENCE AND MID-LAYER DRIER AIR ASSOCIATED WITH THE HIGH
/SEE THE 28.12Z CHATHAM SOUNDING/. LESSER CONFIDENCE ON THE
THUNDER RISK...AND WILL CONTINUE TO KEEP IT OUT OF THE FORECAST
FOR TODAY.
28.12Z HRRR IS THE BEST MODEL BY FAR. THEREAFTER...THE FORECAST
PATTERN IS SUCCINCT WITH THE MCS REMNANTS MOVING EAST-NORTHEAST
WITH THE 0-6 KM MEAN WIND THROUGH NORTHERN NEW ENGLAND AND THE
SAINT LAWRENCE RIVER VALLEY WITH THE BETTER DYNAMICS ALONG THE
SURFACE WARM FRONT. THE LATEST 28.12Z NAM HAS THE HEAVIER
PRECIPITATION SLIGHTLY SOUTH THAN ITS PREDECESSOR...WITH ALL OTHER
GUIDANCE REMAINING NORTH. WHILE AWAITING LATER GUIDANCE...FEELING
IS FOR BETTER PRECIPITATION CHANCES NORTH AND WEST INTO THE
EVENING...WHILE SOUTH AND EAST WILL SUCCUMB TO SUBSIDENCE AND
DRIER AIR.
PREVIOUS DISCUSSION...
SFC WARM FRONT APPROACHES FROM THE NW. HOWEVER...FAIRLY DRY
SOUNDING PROFILE UNDER SUBSIDENCE INVERSION SUGGESTS MOSTLY DRY WX
CONTINUES INTO THE DAY THROUGH THE DAY TODAY. WILL NEED TO WATCH
UPSTREAM POTENTIAL CONVECTIVE DEVELOPMENT AS THIS WILL HAVE TWO
EFFECTS...MAINLY ON THE CONVECTIVE AND RAIN THREAT OVERNIGHT AND
ON HOW QUICKLY SKIES BECOME COMPLETELY OVC FROM ANY CI BLOWOFF.
OTHERWISE...A FAIRLY PLEASANT DAY WITH TEMPS REACHING INTO THE
LOW TO MID 70S ONCE AGAIN WITH ONLY SLOWLY INCREASING SFC
DEWPOINTS. SEA BREEZES ARE LIKELY TO KEEP NEAR SHORE LOCATIONS
COOLER AND IN THE 60S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
TONIGHT...
ON THE SYNOPTIC SCALE...SFC WARM FRONT APPROACHES FROM THE SW AS
UPPER LVL SHORTWAVE MOVES ACROSS THE AREA FROM NY. SOUNDINGS
SUGGEST THAT THE MID LVL WARM FRONT MOVES WELL AHEAD OF THE SFC
WARM FRONT...ALLOWING H85 TEMPS TO INCREASE QUICKLY OVERNIGHT AND
PRODUCING A STABLE /AND INVERTED/ NEAR SFC PROFILE. GUIDANCE IS
NOW CONVERGING ON THE TIMING OF THE SFC FRONT...SUGGESTING IT IS
ONLY JUST AT THE SW BOX CWA DOORSTEP BY 12Z. THEREFORE...SOUNDINGS
ARE QUITE STABLE THROUGHOUT /ESPECIALLY NEAR THE SFC/ WITH BEST
UPPER LVL COOLING AND SFC WARMING HOLDING OFF UNTIL DAYBREAK.
WILL NEED TO AT LEAST WATCH UPSTREAM CONVECTIVE DEVELOPMENT
THROUGH THE AFTERNOON AS SOME GUIDANCE HAS PUSHED THE REMNANTS OF
AN MCC THROUGH THE REGION DURING THE OVERNIGHT HOURS.
HOWEVER...RECENT GUIDANCE TRENDS LOOKS FAVORABLE...SUGGESTING ANY
REMNANT CONVECTION WOULD BE WEAKENING RAPIDLY AS IT APPROACHES SRN
NEW ENGLAND. STILL IS AT LEAST SOME /NEAR 30-40 KT/ 0-6KM BULK
SHEAR NOTED AHEAD OF THE FRONT...BUT WITH LITTLE INSTABILITY
THROUGH ABOUT H5 THERE WILL BE LITTLE TO WORK WITH. PRIMARY THREAT
DURING THE OVERNIGHT HOURS IS AN ISOLATED RUMBLE OF THUNDER AND
BRIEF HEAVY DOWNPOUR AS ANY REMNANT CONVECTION MOVES E AS PWAT
VALUES INCREASE TO 1.5 INCHES. WILL AT LEAST NEED TO MONITOR ANY
SHIFT IN WARM FRONT POSITIONING HOWEVER...BECAUSE A SLIGHT
ADJUSTMENT COULD ALLOW CONVECTION TO HOLD UNTIL REACHING SRN NEW
ENGLAND...BUT FOR NOW BEST INSTABILITY AND STEERING FLOW LOOKS TO
STAY SW THROUGH 12Z.
WED...
WITH DIURNAL TEMP INCREASE AND HELP FROM SUNRISE...EXPECT THAT SFC
WARM FRONT WILL GRADUALLY LIFT THROUGH THE AREA DURING THE DAY.
THIS WILL ALLOW INCREASING SFC TEMPS AND DWPTS /WHICH REACH INTO
THE 60S BY AFTERNOON/. AT THE SAME TIME...SECONDARY SHORTWAVE IS
EXPECTED TO PUSH THROUGH THE AREA DURING THE AFTERNOON WITH SOME
DECREASE IN H5 TEMPS. GIVEN THESE FACTORS...CONTINUE TO NOTE
DECREASING STABILITY THROUGH THE DAY WITH THE POTENTIAL FOR SB
CAPE VALUES APPROACHING 1000-1500 J/KG BY THE AFTERNOON. SHOULD
THERE BE A FEW BREAKS OF SUN IN THE WARM SECTOR AS THE FRONT LIFTS
N...THIS COULD EASILY APPROACH 2000+ J/KG. WITH UPPER LVL WAVE AND
SFC BOUNDARY IN PLACE...FEEL THERE WILL BE ENOUGH OF A FOCUS FOR
LIFT TO REALIZE THIS INSTABILITY THROUGH THE DAY.
BULK SHEAR VALUES REACH 30-40 KT DURING THE DAY WITH A HODOGRAPH
SUGGESTING NEARLY UNIFORM SHEAR DURING THE AFTERNOON. COMBINE THIS
WITH A DECENT INVERTED-V PROFILE IN SOUNDINGS AND THE PRIMARY
THREAT LOOKS TO BE STRONG-GUSTY WINDS WITH ANY POTENTIALLY SEVERE
THUNDERSTORMS. LOW TO MID LVL HELICITY VALUES ARE NOT EXTREME
HERE...BUT DO AT LEAST SUGGEST SOME ROTATING UPDRAFTS POSSIBLE.
NORMALIZED CAPE VALUES ARE LOW...SO WITH ONLY MODEST ROTATING
UPDRAFTS...HAIL THREAT LOOKS TO BE LOWER THAN STRONG WIND THREAT.
IN ANY STORMS...BRIEF HEAVY RAIN POSSIBLE AS WELL WITH PWAT VALUES
IN 1.5+ INCHES...BUT STORMS SHOULD MOVE FAIRLY WELL GIVEN THE
UNI-DIRECTIONAL WIND PROFILE. THE BEST THREAT FOR SEVERE STORMS
LOOK TO BE TOWARD THE N AND W OF THE AREA...CLOSER TO THE WARM
FRONT FOR LIFT TO THE N...AND DEEPER IN THE WARM SECTOR AS ONE
HEADS W. THEREFORE...BEST THREAT FOR SEVERE LOOKS TO BE IN WRN
MA/CT AND SW NH THROUGH THE AFTERNOON. THIS COINCIDES WITH 28/06Z
CATEGORICAL SPC OUTLOOK UPDATE WITH SLIGHT RISK IN THIS REGION.
WILL CONTINUE WITH PREVIOUS SHIFTS THINKING...ADDING ENHANCED
WORDING FOR GUSTY WINDS AND SMALL HAIL WITH THIS UPDATE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
BIG PICTURE...
GULF OF ALASKA LOW DIGS OVER THE PAC NORTHWEST AND ROCKIES...WHICH
INDUCES THE EASTERN UPPER RIDGE TO BUILD THROUGH SATURDAY. THIS
LEAVES A CLEAR PATH FOR THE WARM HUMID AIR IN THE NATION/S
MIDSECTION TO MOVE NORTHEAST INTO NEW ENGLAND. THE TROUGH OVER THE
ROCKIES WILL MOVE INTO THE PLAINS OVER THE WEEKEND. MODELS AGREE
ON THE UPPER RIDGE SHIFTING OVER THE OCEAN EARLY NEXT
WEEK...MAKING ROOM FOR THE SHORTWAVE AND ITS SUPPORTING UPPER JET
TO MOVE INTO THE NORTHEAST USA.
MODEL PREFERENCES...
UPPER CONTOUR FIELDS ARE SIMILAR FOR MOST OF THE PERIOD. THE
ECMWF IS A LITTLE SHARPER WITH THE SHORTWAVE TROUGH EARLY NEXT
WEEK. PREFER A BLEND OF HPC/GMOS AND ECMWF/GFS DATA.
THE DAILIES...
WEDNESDAY NIGHT...
UPPER SHORTWAVE RACES ACROSS NEW ENGLAND PUSHING A WARM FRONT
THROUGH THE REGION. ACTUALLY...THERE IS ALSO A COLD FRONT HIDDEN
IN THE MODEL FIELDS...BUT ONE SO WEAK THAT ITS EFFECTS COULD BE
OVERLOOKED. TEMPS ALOFT CONTINUE TO RISE OVERNIGHT. SUFFICIENT
MOISTURE ALOFT AND TOTALS 45-50...SO SHOWERS/TSTMS ARE REASONABLE.
TEMPS ARE A BLEND OF MOS.
THURSDAY THROUGH SUNDAY...
UPPER RIDGE BUILDS OVER THE REGION FOR THE LATE WEEK. TEMPS ALOFT
UNDER THIS RIDGE ALSO BUILD WITH TEMPS AT THE TOP OF THE MIXED
LAYER EQUIVALENT TO 17-18C AT 850 MB ESPECIALLY ON FRIDAY-
SATURDAY. MEANWHILE THE PRESSURE GRADIENT SUPPORTS A SOUTHWEST
WIND AND LOOKS TOO STRONG FOR AN EAST COAST SEABREEZE. THIS
SUPPORTS MAX TEMPS 85-95 WITH THE WARMEST MAX TEMPS FRIDAY-
SATURDAY. DEWPOINTS INCREASE INTO THE 60S WHICH IS SUPPORTED BY
OBSERVED DEWPOINTS OVER THE SOUTHERN PLAINS AND LOWER MISS RIVER
VALLEY...HIGHER VALUES ARE ONLY ALONG THE TEXAS GULF COAST. THIS
WILL GIVE US A TASTE OF SUMMER HUMIDITY AND KEEP MIN TEMPS IN THE
60S.
CONVECTION WILL BE A QUESTION THROUGH THE PERIOD. THE UPPER HIGH
AND SUBSIDENT FLOW WILL WORK AGAINST ANY STORMS FORMING. BUT
STABILITY PARAMETERS WILL REMAIN FAVORABLE...TOTALS HOLD AT 47 TO
50 PER ECMWF. SO CONVECTION IS POSSIBLE ANY OF THESE DAYS...BUT
WITH LOW LIKELIHOOD THURSDAY AND FRIDAY. BEST CHANCE WILL BE
SATURDAY AND SUNDAY IN THE CT VALLEY AND BERKSHIRE EAST
SLOPE...BUT WITH A CHANCE LATER IN THE DAY FARTHER EAST.
MONDAY...
UPPER TROUGH FROM THE WEST COAST MOVES OVER NEW ENGLAND EARLY
NEXT WEEK. THIS WILL PUSH A COLD FRONT THROUGH THE REGION. THE
UPPER JET MOVING THROUGH THE TROUGH WILL PRESENT A RIGHT ENTRANCE
REGION OVER OUR AREA WHICH WILL ENHANCE LIFT OVER THE HUMID
UNSTABLE AIRMASS. SO SHOWERS/TSTMS ARE POSSIBLE.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
OVERVIEW THROUGH WED...HIGH CONFIDENCE THROUGH TODAY...WITH LOWER
CONFIDENCE TONIGHT INTO WED.
VFR UNDER HIGH PRES CONTINUES THROUGH THE DAY TOMORROW.
HOWEVER...PERIODS OF MVFR/IFR OCCUR THIS EVENING...INTO THE
OVERNIGHT HOURS FROM SW TO NE AS A WARM FRONT APPROACHES. LOW
CONFIDENCE IN THUNDER FOR TONIGHT. DURING THE DAY WED...SOME
SHOWERS AND THUNDERSTORMS ARE POSSIBLE...ESPECIALLY NORTH OF THE
MA PIKE. SEA BREEZES LIKELY TODAY.
KBOS TERMINAL...HIGH CONFIDENCE. SEA-BREEZE AROUND 15Z TUESDAY.
ONSET OF RAIN LATE WED EVENING.
KBDL TERMINAL...HIGH CONFIDENCE. ONSET OF RAIN INTO THE EVENING
HOURS.
OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY...
WEDNESDAY NIGHT...
SHOWERS/TSTMS WITH PERIODS OF IFR/MVFR CIGS AND VSBYS. POTENTIAL
FOR IFR/LIFR CIGS/VSBYS IN FOG LATE AT NIGHT.
THURSDAY THROUGH SATURDAY...
MOSTLY VFR. ISOLATED TSTMS POSSIBLE THURSDAY ESPECIALLY VICINITY
OF THE CT VALLEY. BETTER CHANCE OF BRIEF MVFR/IFR IN TSTMS ON
SATURDAY.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
MODERATE CONFIDENCE THROUGH THE PERIOD.
MAINLY QUIET BOATING WEATHER CONTINUES TODAY. HOWEVER TONIGHT...
EXPECT A WARM FRONT TO ALLOW SOUTHERLY WINDS TO GRADUALLY INCREASE
ALONG WITH SEAS INTO THE DAY WED. SEAS WILL LIKELY REACH 5-6 FT
EARLY WED MORNING FIRST ON SRN WATERS...THEN ERN WATERS DURING THE
DAY WED. WIND GUSTS NEAR 25 KT POSSIBLE AT TIMES WED AS WELL.
THEREFORE...WILL ISSUE SMALL CRAFT ADVISORIES FOR EARLY MORNING
WED INTO THE DAY WED...PRIMARILY ON OCEAN WATERS.
OTHERWISE...SOME SHOWERS AND FOG MAY LEAD TO REDUCTION IN
VISIBILITY OVERNIGHT TONIGHT. ON WED...THERE IS A THREAT FOR
THUNDERSTORMS...WHICH MAY HAVE SOME STRONG WINDS AND SMALL HAIL
PARTICULARLY DURING THE AFTERNOON HOURS.
OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY...
WEST TO SOUTHWEST WIND REMAINS BELOW 25 KNOTS THROUGH THE PERIOD.
BUT THE WIND WILL BUILD SEAS OF 5-7 FEET ESPECIALLY ON THE
SOUTHERN EXPOSED WATERS. A LENGTHY SMALL CRAFT ADVISORY WILL BE
NEEDED FOR THESE SEAS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 AM TO 8 PM EDT WEDNESDAY FOR
ANZ235-237-255-256.
SMALL CRAFT ADVISORY FROM 8 AM TO 8 PM EDT WEDNESDAY FOR
ANZ250-254.
&&
$$
SYNOPSIS...WTB/DOODY
NEAR TERM...SIPPRELL
SHORT TERM...DOODY
LONG TERM...WTB
AVIATION...WTB/DOODY
MARINE...WTB/DOODY
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
621 AM EDT TUE MAY 28 2013
.SYNOPSIS...
A WARM FRONT WILL LIFT ACROSS THE AREA THIS AFTERNOON AND EARLY
TONIGHT. HIGH PRESSURE OFF THE EAST COAST WILL RIDGE BACK ACROSS OUR
AREA FOR THE MIDDLE AND LATE PARTS OF THIS WEEK. LOW PRESSURE WILL
MOVE NORTH OF THE REGION SATURDAY AND SUNDAY AND SEND A COLD FRONT
ACROSS THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
610 AM ESTF PRODUCTS UPDATE: RAISED POPS A BIT...EXPANDED AREA FOR
POTENTIALLY BRIEFLY HEAVY SHOWERS INTO SE PA AND S CENTRAL NJ AND
COOLED TEMPS SEVERAL DEGREES IN NNJ.
TODAY...IT LOOKS AS THOUGH THE CONVECTIVE MODELS FROM NCEP HAVE
AGAIN PREVAILED WHEN COMPARED TO YDYS 00Z/27 CYCLE OF THE
RGEM/GGEM/ECMWF/UKMET. A DECENT SLUG OF SHOWERS IS FORECAST TODAY
WITH A N/S BAND OF BRIEFLY MODERATE TO HEAVY RAIN SWEEPING EWD WITHIN
THE GROWING AREA OF RAIN ACROSS PA/NJ. THE 00Z/28 SPC WRF IS TO MY
OVERALL LIKING AND IS MATCHED PRETTY WELL BY THE RAP WHICH DOESNT
GIVE ANY POTENTIAL FOR THUNDER TIL VERY LATE THIS AFTN..IF AT
ALL...IN SE PA/MD. SO NO THUNDER IN THE FCST TODAY. THE RAP WAS
FURTHER NORTH THAN THE SPCWRF WITH ITS RAIN AREA AND OPTED FOR
THE MORE EXPANSIVE SPC WRF DEPICTION OF RAINFALL AND A BAND OF MDT
TO HEAVY EVEN DOWN TO PHL. 12Z HPCQPF HAS SPREAD THE AXIS OF HEAVY
RAIN A BIT FURTHER SOUTH.
THE DRIVERS FOR TODAYS RFALL ARE THE RRQ OF A NW FLOW 250 MB 80-90
KT SPEED MAX E OF CAPE COD AND THE INSTABILITY BURST ASSOCIATED
AND DRIVEN BY A 35-40 KT WLY 700MB SPEED MAX (MOISTURE TRANSPORT)
MOVING ACROSS PA WITH SW FLOW AT 850 MB AIDING LIFT. WHILE THE
MOST PERSISTENT AND WIDESPREAD SHOWERS WITHOUT THUNDER SHOULD
OCCUR NJ/PA NEAR THE AXIS OF THE 700MB JET SPEED MAX...THERE IS A
CHANCE FOR A CONVECTIVE THUNDER OUTBREAK NEAR THE MASON DIXON LINE
LATE THIS AFTN WHERE IT WILL HEAT UP S OF THE GENERAL SHOWER AREA...
PRODUCING ABOUT 600J OF ML CAPE.
REGARDING MOISTURE: THE PWAT AT 03Z/28 (11PM MONDAY) WAS ABOUT
ONE HALF INCH AND IS MODELED TO INCREASE TO 1.5 INCHES BY LATE
THIS TUE AFTN!
TEMPS WINDS AND DEWPOINTS ARE BLENDED 00Z/28 NCEP MOS GUIDANCE AND
HIGH TEMPS COULD BE A COUPLE OF DEGREES TOO WARM IN NNJ DEPENDING
ON WHETHER ITS RAINING MUCH OF THE TIME BETWEEN 11 AM AND 5 PM.
THE 610 AM UPDATE COOLED TEMPS SEVERAL DEGREES THERE.
THE SFC WARM FRONT WILL EVOLVE NEWD AND BY 21Z LIE ROUGHLY FROM KDMH
TO KMIV. STRONGER SLY WINDS TO 20-25 KT WILL OCCUR TO THE SOUTH OF
THE WARMFRONT WHERE IT HEATS UP.
LATEST COSPA...RAP-RUC AS WELL AS 00Z/28 SPC WRF WERE USED TO
ASSIST IN THE FCST AND TIMING!
06Z/28 HPC QPF WAS ALSO APPLIED...ADJUSTED A BIT SWD IN E PA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
SHOWERS WITH ISOLATED TSTMS ARE POSSIBLE PRIOR TO 06Z BUT CONFIDENCE
ON TONIGHTS SHOWER SCENARIO IS BELOW AVERAGE. MOST OF THE RAINFALL
SHOULD OCCUR PRIOR TO 00Z/29. THERE IS A SMALL CHANCE WE`LL NEED
TO ISSUE AN SPS FOR A GROUP OF TSTMS...POSSIBLY A SEWD MOVING
CONVECTIVE BAND CROSSING CHES BAY EARLY THIS TUE EVENING AND THEN
ANOTHER EWD MOVING CONVECTIVE CLUSTER IN THE 35C KI ACROSS NNJ
AROUND 06Z? THIS LATTER MIGHT BE THE SRN EDGE OF DIMINISHING NEAR
SVR DRIVING EWD FROM THE UPPER OHIO VALLEY AS DISCUSSED IN THE
0602Z/28 SWODY1.
TEMPS/WINDS/DEWPOINTS ARE 50 50 BLENDED 00Z/28 NCEP MOS MET/MAV
GUIDANCE.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
BUILDING H5 HEIGHTS AND A SFC HIGH WHICH WILL RIDGE BACK ACROSS THE
AREA WILL BRING WARM AND INCREASINGLY HUMID AIR TO THE REGION
BEGINNING WEDNESDAY AND LASTING INTO THE WEEKEND. THE FIRST HEAT
WAVE OF THE SEASON MAY RESULT...BUT NO HEAT RELATED FLAGS HAVE BEEN
ISSUED WITH THE OVERNIGHT FCST.
WED...THE SHORTWAVE/WARM FRONT FEATURE FROM THE SHORT TERM WILL BE
EXITING TO THE NORTH/EAST/ A FEW LINGERING SHOWERS MAY STILL AFFECT
THE AREA ACROSS NRN NJ EARLY AND ALSO A FEW SCT TSTMS ARE POSSIBLE
DURING THE AFTERNOON ACROSS THE NRN AREAS. ELSEWHERE...IT SHOULD
REMAIN DRY AND VERY WARM. HIGHS MOSTLY IN THE MID/UPPER 80S WITH
COOLER TEMPS AT THE BEACHES. WED NIGHT...DRY WITH LOWS IN THE LOW TO
MID 60S NORTH AND MID TO UPPER 60S SOUTH. READINGS WILL HOLD NEAR
70 IN METRO PHILADELPHIA.
THU THRU SAT...ESSENTIALLY A DRY FCST WITH THE UPPER RIDGE BUILDING
ACROSS THE AREA THRU FRI BEFORE MOVING OFF TO THE EAST SAT. A FEW
SHOWERS MAY AFFECT THE NRN MOST PART OF NJ THU EVENING WITH ONLY
SLGT CHC POPS IN THE FCST. INCREASINGLY HOT AND HUMID WITH HIGHS IN
THE UPPER 80S/LOW 90S THU AND LOWS MOSTLY IN THE UPPER 60S AND LOW
70S.
SUN AND MON...THE HEAT WAVE BREAKS LATER SUN AFTER A DAY WITH HIGHS
IN THE UPPER 80S. MORE CLOUDS AND BETTER CHCS FOR SHOWERS/TSTMS AS A
SYNOPTIC SYSTEM CROSSES SRN CANADA AND SENDS A COLD FRONT ACROSS THE
AREA LATER SUNDAY. HIGHS MON WILL MOSTLY BE IN UPPER 70S NORTH AND
LOW 80S SOUTH.
&&
.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
TODAY ...SHOWERS BECOMING WIDESPREAD KPHL NORTH THIS MORNING
WITH MVFR CONDS DEVELOPING NEAR OR AFTER 17Z....POSSIBLY SPOTTY
IFR CIGS BY 00Z/29. LIGHT WIND TENDING E OR SE THIS AFTN EXCEPT
BECOMING SLY KMIV SOUTHWARD LATE IN THE DAY.
TONIGHT...MVFR OR IFR CONDS IN ST/FOG KRDG KABE KTTN WITH MVFR CONDS
ELSEWHERE IN SC/FOG/HAZE. CHANCE OF A SHOWER. SMALL CHANCE OF A TSTM.
WIND GRADUALLY VEERING FROM SSE TO SW DURING THE NIGHT.
OUTLOOK...
WEDNESDAY...A FEW LINGERING SHOWERS FAR NORTH EARLY AND THEN A CHC
FOR AN AFTERNOON TSTM N/W. VFR ELSEWHERE.
THU THRU SAT...MOSTLY VFR. PATCHY FOG POSSIBLE AT NIGHT.
&&
.MARINE...
SUB-ADVISORY CONDITIONS WILL PERSIST ACROSS OUR WATERS FOR A BETTER
PART OF TODAY. SEAS WILL SLOWLY INCREASE UPWARDS OF 4 FEET BY THIS
AFTERNOON OFF DELAWARE AS A WARM FRONT LIFTS THROUGH THE REGION.
WINDS ON THE OUTER ATLC WATERS OFF DELAWARE MIGHT GUST TO NEAR 25 KT
LATE IN THE DAY. AN SCA WAS ISSUED ONLY WHERE CONFIDENCE REASONABLY
HIGH THAT 5 FT SEAS WILL OCCUR. CONFIDENCE FOR MAX GUSTS REACHING
25 KT IS LESS THAN OUR SEEING 5 FT SEAS OFF DELAWARE TONIGHT.
THE REMAINDER OF THE NJ WATERS MAY NEED AN SCA TONIGHT OR WED BUT
FOR NOW...CONFIDENCE NOT HIGH ENOUGH TO ISSUE.
OUTLOOK...
MOSTLY SUB-SCA CONDITIONS WED-FRI...THEN INCREASING WINDS AND
BUILDING SEAS THIS WEEKEND WITH SCA POSSIBLE.
AS DEW POINT TEMPERATURES EXCEED THE WATER TEMPERATURES ALONG THE
COASTS OF DELAWARE AND NEW JERSEY FROM WEDNESDAY THROUGH SATURDAY,
THE COASTAL WATERS WILL BE SUSCEPTIBLE TO DEVELOPING FOG BANKS.
&&
.RIP CURRENTS...
TODAY...FCST LOW FOR NJ. KEPT THE ONSHORE GRADIENT WIND TO 15 KT OR
LESS THIS AFTN. CERTAINLY STARTS OUT AS A LOW RISK WITH VIRTUALLY
NO WIND OR SWELL TO START THE DAY. DELAWARE WILL ALSO BE A LOW
RISK TODAY.
15 KT IS THE KEY TO THE ONSHORE WIND. BELOW 15 KT FAVORS LOW
RISK.
NO MATTER...EVEN AT LOW RISK...IF YOU DONT SWIM UNDER THE WATCHFUL
EYE OF A LIFE GUARD...YOU COULD BE ASKING FOR TROUBLE. RIP CURRENTS
CAN FORM ANYTIME...ESPECIALLY IN THE LOWER HALF OF THE TIDE CYCLE.
THIS SHOULD BE KEPT IN MIND AS IT HEATS UP LATER IN THE WEEK!
ALSO THE SSTS ARE COLD...LOWER 50S (LBI THIS MORNING) VARIABLE UP
TO THE LOWER 60S. SWIM WITH SAFETY IN MIND!
THE DAILY OUTLOOK FOR THE REST OF THE WEEK LOOKS TO BE A GENERALLY
LOW RISK.
TODAY...LOW OR MDT IN NJ AND LOW DE. DEPENDS ON THE WIND SPEED AND
SWELL GROUP. 2FT 9SEC OR 4FT 6 SEC WILL GIVE MDT IF THE ONSHORE
WIND REACHES 16 KT. IF THE SWELL SIZE OF EITHER GROUP OR THE WIND
IS LESS THAN 16 KT...THE RISK DROPS TO LOW.
WEDNESDAY...1FT 9 SEC OR 4 FT 6 SEC WIND 18013 LOW RISK
THURSDAY...1 FT 8 SEC OR 4 FT 6 SEC WIND 18011 LOW RISK
FRIDAY...1 FT 9 SEC OR 3 FT 5 SEC WIND 18011 LOW RISK
SATURDAY...1FT 9 SEC OR 4FT 5 SEC WIND 21013. LOW RISK
RIP CURRENT AWARENESS WEEK IS JUNE 2-8.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM EDT
WEDNESDAY FOR ANZ453>455.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...DRAG 619
SHORT TERM...DRAG 619
LONG TERM...O`HARA
AVIATION...DRAG/O`HARA 619
MARINE...DRAG/O`HARA 619
RIP CURRENTS...619
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
506 AM EDT TUE MAY 28 2013
.SYNOPSIS...
A WARM FRONT WILL LIFT ACROSS THE AREA THIS AFTERNOON AND EARLY
TONIGHT. HIGH PRESSURE OFF THE EAST COAST WILL RIDGE BACK ACROSS OUR
AREA FOR THE MIDDLE AND LATE PARTS OF THIS WEEK. LOW PRESSURE WILL
MOVE NORTH OF THE REGION SATURDAY AND SUNDAY AND SEND A COLD FRONT
ACROSS THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
TODAY...IT LOOKS AS THOUGH THE CONVECTIVE MODELS FROM NCEP HAVE
AGAIN PREVAILED WHEN COMPARED TO YDYS 00Z/27 CYCLE OF THE
RGEM/GGEM/ECMWF/UKMET. A DECENT SLUG OF SHOWERS IS FORECAST TODAY
WITH A N/S BAND OF BRIEFLY MODERATE TO HEAVY RAIN SWEEPING EWD WITHIN
THE GROWING AREA OF RAIN ACROSS PA/NJ. THE 00Z/28 SPC WRF IS TO MY
OVERALL LIKING AND IS MATCHED PRETTY WELL BY THE RAP WHICH DOESNT
GIVE ANY POTENTIAL FOR THUNDER TIL VERY LATE THIS AFTN..IF AT
ALL...IN SE PA/MD. SO NO THUNDER IN THE FCST TODAY. THE RAP IS
FURTHER NORTH THAN THE SPCWRF WITH ITS RAIN AREA AND AM OPTING
FOR THE MORE EXPANSIVE SPC WRF DEPICTION OF RAINFALL AND A BAND OF
MDT TO HEAVY EVEN DOWN TO PHL. 06Z HPCQPF WAS A LITTLE LESS THAN
WHAT I THINK WILL HAPPEN IN PHL...BUT IF THE 700 MB SPEED MAX IS
FURTHER NORTH THAN THE MASON DIXON LINE TODAY...THEN THE HEAVIER
QPF WILL REMAIN UP NORTH....ALONG AND N OF RTE 80.
THE DRIVERS FOR TODAYS RFALL ARE THE RRQ OF A NW FLOW 250 MB 80-90
KT SPEED MAX E OF CAPE COD AND THE INSTABILITY BURST ASSOCIATED
AND DRIVEN BY A 35-40 KT WLY 700MB SPEED MAX (MOISTURE TRANSPORT)
MOVING ACROSS PA WITH SW FLOW AT 850 MB AIDING LIFT. WHILE THE
MOST PERSISTENT AND WIDESPREAD SHOWERS WITHOUT THUNDER SHOULD
OCCUR NJ/PA NEAR THE AXIS OF THE 700MB JET SPEED MAX...THERE IS A
CHANCE FOR A CONVECTIVE THUNDER OUTBREAK NEAR THE MASON DIXON LINE
LATE THIS AFTN WHERE IT WILL HEAT UP S OF THE GENERAL SHOWER AREA...
PRODUCING ABOUT 600J OF ML CAPE.
REGARDING MOISTURE: THE PWAT AT 03Z/28 (11PM MONDAY) WAS ABOUT
ONE HALF INCH AND IS MODELED TO INCREASE TO 1.5 INCHES BY LATE
THIS TUE AFTN!
TEMPS WINDS AND DEWPOINTS ARE BLENDED 00Z/28 NCEP MOS GUIDANCE AND
HIGH TEMPS COULD BE 5 DEGREES TOO WARM IN NNJ DEPENDING ON WHETHER
ITS RAINING MUCH OF THE TIME BETWEEN 11 AM AND 5 PM. I MAY RUN THESE
NNJ TEMPS 5 DEGREES COOLER IN MY 630 AM ESTF UPDATE.
THE SFC WARM FRONT WILL EVOLVE NEWD AND BY 21Z LIE ROUGHLY FROM KDMH
TO KMIV. STRONGER SLY WINDS TO 20-25 KT WILL OCCUR TO THE SOUTH OF
THE WARMFRONT WHERE IT HEATS UP.
LATEST COSPA...RAP-RUC AS WELL AS 00Z/28 SPC WRF WERE USED TO
ASSIST IN THE FCST AND TIMING!
06Z/28 HPC QPF WAS ALSO APPLIED...ADJUSTED A BIT SWD IN E PA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
SHOWERS WITH ISOLATED TSTMS ARE POSSIBLE PRIOR TO 06Z BUT CONFIDENCE
ON TONIGHTS SHOWER SCENARIO IS BELOW AVERAGE. MOST OF THE RAINFALL
SHOULD OCCUR PRIOR TO 00Z/29. THERE IS A SMALL CHANCE WE`LL NEED
TO ISSUE AN SPS FOR A GROUP OF TSTMS...POSSIBLY A SEWD MOVING
CONVECTIVE BAND CROSSING CHES BAY EARLY THIS TUE EVENING AND THEN
ANOTHER EWD MOVING CONVECTIVE CLUSTER IN THE 35C KI ACROSS NNJ
AROUND 06Z? THIS LATTER MIGHT BE THE SRN EDGE OF DIMINISHING NEAR
SVR DRIVING EWD FROM THE UPPER OHIO VALLEY AS DISCUSSED IN THE
0602Z/28 SWODY1.
TEMPS/WINDS/DEWPOINTS ARE 50 50 BLENDED 00Z/28 NCEP MOS MET/MAV
GUIDANCE.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
BUILDING H5 HEIGHTS AND A SFC HIGH WHICH WILL RIDGE BACK ACROSS THE
AREA WILL BRING WARM AND INCREASINGLY HUMID AIR TO THE REGION
BEGINNING WEDNESDAY AND LASTING INTO THE WEEKEND. THE FIRST HEAT
WAVE OF THE SEASON MAY RESULT...BUT NO HEAT RELATED FLAGS HAVE BEEN
ISSUED WITH THE OVERNIGHT FCST.
WED...THE SHORTWAVE/WARM FRONT FEATURE FROM THE SHORT TERM WILL BE
EXITING TO THE NORTH/EAST/ A FEW LINGERING SHOWERS MAY STILL AFFECT
THE AREA ACROSS NRN NJ EARLY AND ALSO A FEW SCT TSTMS ARE POSSIBLE
DURING THE AFTERNOON ACROSS THE NRN AREAS. ELSEWHERE...IT SHOULD
REMAIN DRY AND VERY WARM. HIGHS MOSTLY IN THE MID/UPPER 80S WITH
COOLER TEMPS AT THE BEACHES. WED NIGHT...DRY WITH LOWS IN THE LOW TO
MID 60S NORTH AND MID TO UPPER 60S SOUTH. READINGS WILL HOLD NEAR
70 IN METRO PHILADELPHIA.
THU THRU SAT...ESSENTIALLY A DRY FCST WITH THE UPPER RIDGE BUILDING
ACROSS THE AREA THRU FRI BEFORE MOVING OFF TO THE EAST SAT. A FEW
SHOWERS MAY AFFECT THE NRN MOST PART OF NJ THU EVENING WITH ONLY
SLGT CHC POPS IN THE FCST. INCREASINGLY HOT AND HUMID WITH HIGHS IN
THE UPPER 80S/LOW 90S THU AND LOWS MOSTLY IN THE UPPER 60S AND LOW
70S.
SUN AND MON...THE HEAT WAVE BREAKS LATER SUN AFTER A DAY WITH HIGHS
IN THE UPPER 80S. MORE CLOUDS AND BETTER CHCS FOR SHOWERS/TSTMS AS A
SYNOPTIC SYSTEM CROSSES SRN CANADA AND SENDS A COLD FRONT ACROSS THE
AREA LATER SUNDAY. HIGHS MON WILL MOSTLY BE IN UPPER 70S NORTH AND
LOW 80S SOUTH.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
PRIOR TO 12Z TUE...VFR CIGS WITH CIGS LOWERING TO 5000 FT SE PA
AND DE IN ISOLATED SHOWERS. LIGHT WIND.
AFTER 12Z TUE...SHOWERS BECOMING WIDESPREAD KPHL NORTH BY 15Z WITH
MVFR CONDS DEVELOPING NEAR OR AFTER 17Z....POSSIBLY SPOTTY IFR CIGS
BY 00Z/29. LIGHT WIND TENDING E OR SE THIS AFTN EXCEPT BECOMING
SLY KMIV SOUTHWARD LATE IN THE DAY.
TONIGHT...MVFR OR IFR CONDS IN ST/FOG KRDG KABE KTTN WITH MVFR CONDS
ELSEWHERE IN SC/FOG/HAZE. CHANCE OF A SHOWER. SMALL CHANCE OF A TSTM.
WIND GRADUALLY VEERING FROM SSE TO SW DURING THE NIGHT.
OUTLOOK...
WEDNESDAY...A FEW LINGERING SHOWERS FAR NORTH EARLY AND THEN A CHC
FOR AN AFTERNOON TSTM N/W. VFR ELSEWHERE.
THU THRU SAT...MOSTLY VFR. PATCHY FOG POSSIBLE AT NIGHT.
&&
.MARINE...
SUB-ADVISORY CONDITIONS WILL PERSIST ACROSS OUR WATERS FOR A BETTER
PART OF TODAY. SEAS WILL SLOWLY INCREASE UPWARDS OF 4 FEET BY THIS
AFTERNOON OFF DELAWARE AS A WARM FRONT LIFTS THROUGH THE REGION.
WINDS ON THE OUTER ATLC WATERS OFF DELAWARE MIGHT GUST TO NEAR 25 KT
LATE IN THE DAY. AN SCA WAS ISSUED ONLY WHERE CONFIDENCE REASONABLY
HIGH THAT 5 FT SEAS WILL OCCUR. CONFIDENCE FOR MAX GUSTS REACHING
25 KT IS LESS THAN OUR SEEING 5 FT SEAS OFF DELAWARE TONIGHT.
THE REMAINDER OF THE NJ WATERS MAY NEED AN SCA TONIGHT OR WED BUT
FOR NOW...CONFIDENCE NOT HIGH ENOUGH TO ISSUE.
OUTLOOK...
MOSTLY SUB-SCA CONDITIONS WED-FRI...THEN INCREASING WINDS AND
BUILDING SEAS THIS WEEKEND WITH SCA POSSIBLE.
AS DEW POINT TEMPERATURES EXCEED THE WATER TEMPERATURES ALONG THE
COASTS OF DELAWARE AND NEW JERSEY FROM WEDNESDAY THROUGH SATURDAY,
THE COASTAL WATERS WILL BE SUSCEPTIBLE TO DEVELOPING FOG BANKS.
&&
.RIP CURRENTS...
FOR TODAY...SITTING ON THE THRESHOLD OF LOW OR MDT RISK FOR
THE FORMATION OF DANGEROUS RIP CURRENTS IN NJ THIS AFTN. WILL DO
A FINAL CHECK OF THE 06Z GFS WIND FCST FOR 18Z TODAY AND ISSUE THE
SRF AT 550 AM EDT. CERTAINLY STARTS OUT AS A LOW RISK WITH VIRTUALLY
NO WIND OR SWELL TO START THE DAY. DELAWARE WILL BE A LOW RISK
TODAY.
IF THE SFC WIND SPEED REMAINS BELOW 15 KT ALONG THE NJ COAST THIS
AFTN...THAT WOULD FAVOR A LOWER RISK.
NO MATTER...EVEN AT LOW RISK...IF YOU DONT SWIM UNDER THE WATCHFUL
EYE OF A LIFE GUARD...YOU COULD BE ASKING FOR TROUBLE. RIP CURRENTS
CAN FORM ANYTIME...ESPECIALLY IN THE LOWER HALF OF THE TIDE CYCLE.
THIS SHOULD BE KEPT IN MIND AS IT HEATS UP LATER IN THE WEEK! ALSO
THE SSTS ARE COLD...MID 50S TO LOWER 60S. SWIM WITH SAFETY IN MIND!
THE DAILY OUTLOOK FOR THE REST OF THE WEEK LOOKS TO BE A GENERALLY
LOW RISK.
TODAY...LOW OR MDT IN NJ AND LOW DE. DEPENDS ON THE WIND SPEED AND
SWELL GROUP. 2FT 9SEC OR 4FT 6 SEC WILL GIVE MDT IF THE ONSHORE
WIND REACHES 16 KT. IF THE SWELL SIZE OF EITHER GROUP OR THE WIND
IS LESS THAN 16 KT...THE RISK DROPS TO LOW.
WEDNESDAY...1FT 9 SEC OR 4 FT 6 SEC WIND 18013 LOW RISK
THURSDAY...1 FT 8 SEC OR 4 FT 6 SEC WIND 18011 LOW RISK
FRIDAY...1 FT 9 SEC OR 3 FT 5 SEC WIND 18011 LOW RISK
SATURDAY...1FT 9 SEC OR 4FT 5 SEC WIND 21013. LOW RISK
RIP CURRENT AWARENESS WEEK IS JUNE 2-8.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM EDT
WEDNESDAY FOR ANZ453>455.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...DRAG 505
SHORT TERM...DRAG 505
LONG TERM...O`HARA
AVIATION...DRAG/O`HARA 505
MARINE...DRAG/O`HARA 505
RIP CURRENTS...505
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
347 AM EDT TUE MAY 28 2013
.SYNOPSIS...
A WARM FRONT WILL LIFT ACROSS THE AREA THIS AFTERNOON AND EARLY
TONIGHT. HIGH PRESSURE OFF THE EAST COAST WILL RIDGE BACK ACROSS OUR
AREA FOR THE MIDDLE AND LATE PARTS OF THIS WEEK. LOW PRESSURE WILL
MOVE NORTH OF THE REGION SATURDAY AND SUNDAY AND SEND A COLD FRONT
ACROSS THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WAA CLOUD COVER WELL IN ADVANCE OF AN ACTIVE WARM FRONT AND ALSO
IN THE RRQ OF THE 250MB NW FLOW 80-90KT SPEED MAX ROUGHLY CENTERED OVER
LONG ISLAND IS RESPONSIBLE FOR OVERNIGHT TEMPERATURES NEARLY 10 DEGREES
WARMER THAN EARLY THIS PAST MONDAY MORNING WHEN SPOTTY FROST APPEARED
TO HAVE OCCURRED FROM THE POCONOS TO SUSSEX AND WARREN COUNTIES IN
NJ.
TODAY-TUESDAY...IT LOOKS AS THOUGH THE CONVECTIVE MODELS FROM NCEP
HAVE AGAIN PREVAILED WHEN COMPARED TO YDYS 00Z/27 CYCLE OF THE
RGEM/GGEM/ECMWF/UKMET. A DECENT SLUG OF SHOWERS IS FORECAST TODAY
WITH A N/S BAND OF BRIEFLY MDT TO BRIEFLY RAIN SWEEPING EWD WITHIN
THE GROWING AREA OF RAIN ACROSS PA/NJ. THE 00Z/28 SPC WRF IS TO MY
OVERALL LIKING AND IS MATCHED PRETTY WELL BY THE RAP WHICH DOESNT
GIVE ANY POTENTIAL FOR THUNDER TIL VERY LATE THIS AFTN..IF AT
ALL...IN SE PA/MD. SO NO THUNDER IN THE FCST TODAY. THE RAP IS
FURTHER NORTH THAN THE SPCWRF AND I AM OPTING FOR THE MORE EXPANSIVE
SPC WRF DEPICTION OF RAINFALL AND A BAND OF MDT TO HEAVY EVEN DOWN TO
PHL. 06Z HPC QPF IS A LITTLE LESS THAN WHAT I THINK WILL HAPPEN IN
PHL...BUT IF THE 700 MB SPEED MAX IS FURTHER NORTH THAN THE MASON
DIXON LINE TODAY...THEN THE HEAVIER QPF WILL REMAIN UP NORTH.
THE DRIVERS FOR TODAYS RFALL ARE THE RRQ OF THE PGH 1 MENTIONED
NW FLOW UPPER LVL JET SPEED MAX MOVING E OF CAPE COD AND THE
INSTABILITY BURST DRIVEN ASSOCIATED BY A 35-40 KT WLY 700MB SPEED
MAX (MOISTURE TRANSPORT) MOVING ACROSS PA WITH SW FLOW AT 850 MB
AIDING LIFT. WHILE THE MOST PERSISTENT AND WIDESPREAD SHOWERS
WITHOUT THUNDER SHOULD OCCUR NJ/PA NEAR THE AXIS OF THE 700MB JET
SPEED MAX...THERE IS A CHANCE FOR A CONVECTIVE THUNDER OUTBREAK NEAR
THE MASON DIXON LINE LATE THIS AFTN WHERE IT WILL HEAT UP S OF THE
GENERAL SHOWER AREA...PRODUCING ABOUT 600J OF ML CAPE.
REGARDING MOISTURE: THE PWAT AT 03Z/28 (11PM MONDAY) WAS ABOUT
ONE HALF INCH AND IS MODELED TO INCREASE TO 1.5 INCHES BY LATE
THIS TUE AFTN!
TEMPS WINDS AND DEWPOINTS ARE BLENDED 00Z/28 NCEP MOS GUIDANCE AND
HIGH TEMPS COULD BE 5 DEGREES TOO WARM IN NNJ DEPENDING ON WHETHER
ITS RAINING MUCH OF THE TIME BETWEEN 11 AM AND 5 PM. I MAY RUN THESE
TEMPS COOLER IN MY 630 AM ESTF UPDATE.
THE SFC WARM FRONT WILL EVOLVE NEWD AND BY 21Z LIE ROUGHLY FROM KDMH
TO KMIV. STRONGER SLY WINDS TO 20-25 KT WILL OCCUR TO THE SOUTH OF
THE WARMFRONT WHERE IT HEATS UP.
LATEST COSPA...RAP-RUC AS WELL AS 00Z/28 SPC WRF WERE USED TO
ASSIST IN THE FCST AND TIMING!
06Z/28 HPC QPF WAS ALSO APPLIED...ADJUSTED A BIT SWD IN E PA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
SHOWERS WITH ISOLATED TSTMS ARE POSSIBLE PRIOR TO 06Z BUT CONFIDENCE
ON TONIGHTS SCENARIO IS BELOW AVERAGE. MOST OF THE RAINFALL SHOULD
BE PRIOR TO 00Z/29. THERE IS A SMALL CHANCE WE`LL NEED TO ISSUE AN
SPS FOR A GROUP OF TSTMS...POSSIBLY A SEWD MOVING CONVECTIVE BAND
CROSSING CHES BAY EARLY THIS TUE EVENING AND THEN ANOTHER EWD MOVING
CONVECTIVE CLUSTER IN THE 35C KI ACROSS NNJ AROUND 06Z? THIS LATTER
MIGHT BE THE SRN EDGE OF DIMINISHING NEAR SVR DRIVING EWD FROM THE
UPPER OHIO VALLEY AS DISCUSSED IN THE 0602Z SWODY1.
TEMPS/WINDS/DEWPOINTS ARE 50 50 BLENDED 00Z/28 NCEP MOS MET/MAV
GUIDANCE.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
BUILDING H5 HEIGHTS AND A SFC HIGH WHICH WILL RIDGE BACK ACROSS THE
AREA WILL BRING WARM AND INCREASINGLY HUMID AIR TO THE REGION
BEGINNING WEDNESDAY AND LASTING INTO THE WEEKEND. THE FIRST HEAT
WAVE OF THE SEASON MAY RESULT...BUT NO HEAT RELATED FLAGS HAVE BEEN
ISSUED WITH THE OVERNIGHT FCST.
WED...THE SHORTWAVE/WARM FRONT FEATURE FROM THE SHORT TERM WILL BE
EXITING TO THE NORTH/EAST/ A FEW LINGERING SHOWERS MAY STILL AFFECT
THE AREA ACROSS NRN NJ EARLY AND ALSO A FEW SCT TSTMS ARE POSSIBLE
DURING THE AFTERNOON ACROSS THE NRN AREAS. ELSEWHERE...IT SHOULD
REMAIN DRY AND VERY WARM. HIGHS MOSTLY IN THE MID/UPPER 80S WITH
COOLER TEMPS AT THE BEACHES. WED NIGHT...DRY WITH LOWS IN THE LOW TO
MID 60S NORTH AND MID TO UPPER 60S SOUTH. READINGS WILL HOLD NEAR
70 IN METRO PHILADELPHIA.
THU THRU SAT...ESSENTIALLY A DRY FCST WITH THE UPPER RIDGE BUILDING
ACROSS THE AREA THRU FRI BEFORE MOVING OFF TO THE EAST SAT. A FEW
SHOWERS MAY AFFECT THE NRN MOST PART OF NJ THU EVENING WITH ONLY
SLGT CHC POPS IN THE FCST. INCREASINGLY HOT AND HUMID WITH HIGHS IN
THE UPPER 80S/LOW 90S THU AND LOWS MOSTLY IN THE UPPER 60S AND LOW
70S.
SUN AND MON...THE HEAT WAVE BREAKS LATER SUN AFTER A DAY WITH HIGHS
IN THE UPPER 80S. MORE CLOUDS AND BETTER CHCS FOR SHOWERS/TSTMS AS A
SYNOPTIC SYSTEM CROSSES SRN CANADA AND SENDS A COLD FRONT ACROSS THE
AREA LATER SUNDAY. HIGHS MON WILL MOSTLY BE IN UPPER 70S NORTH AND
LOW 80S SOUTH.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
PRIOR TO 12Z TUE...VFR CIGS WITH CIGS LOWERING TO 5000 FT SE PA
AND DE IN ISOLATED SHOWERS NEAR 12Z. LIGHT WIND.
AFTER 12Z TUE...SHOWERS BECOMING WIDESPREAD KPHL NORTH BY 16Z WITH
MVFR CONDS DEVELOPING NEAR OR AFTER 17Z....POSSIBLY SPOTTY IFR
CIGS BY 00Z/29. LIGHT WIND TENDING E OR SE THIS AFTN EXCEPT BECOMING
SLY KMIV SOUTHWARD LATE IN THE DAY.
TONIGHT...MVFR OR IFR CONDS IN ST/FOG KRDG KABE KTTN WITH MVFR CONDS
ELSEWHERE IN SC/FOG/HAZE. CHANCE OF A SHOWER. SMALL CHANCE OF A TSTM.
WIND GRADUALLY VEERING FROM SSE TO SW DURING THE NIGHT.
OUTLOOK...
WEDNESDAY...A FEW LINGERING SHOWERS FAR NORTH EARLY AND THEN A CHC
FOR AN AFTERNOON TSTM N/W. VFR ELSWEHERE.
THU THRU SAT...MOSTLY VFR. PATCHY FOG POSSIBLE AT NIGHT.
&&
.MARINE...
SUB-ADVISORY CONDITIONS WILL PERSIST ACROSS OUR WATERS FOR A BETTER
PART OF TODAY. SEAS WILL SLOWLY INCREASE UPWARDS OF 4 FEET BY THIS
AFTERNOON OFF DE AS A WARM FRONT LIFTS THROUGH THE REGION. WINDS ON
THE OUTER ATLC WATERS OFF DE MIGHT GUST TO NEAR 25 KT LATE IN THE
DAY. AN SCA WAS ISSUED ONLY WHERE CONFIDENCE REASONABLY HIGH THAT 5
FT SEAS WILL OCCUR. CONFIDENCE FOR MAX GUSTS REACHING 25 KT IS LESS
THAN OUR SEEING 5 FT SEAS OFF DE TONIGHT.
THE REMAINDER OF THE NJ WATERS MAY NEED AN SCA TONIGHT OR WED BUT
FOR NOW...CONFIDENCE NOT HIGH ENOUGH TO ISSUE.
OUTLOOK...
MOSTLY SUB-SCA CONDITIONS WED-FRI...THEN INCREASING WINDS AND
BUILDING SEAS THIS WEEKEND WITH SCA POSSIBLE.
AS DEW POINT TEMPERATURES EXCEED THE WATER TEMPERATURES ALONG THE
COASTS OF DELAWARE AND NEW JERSEY FROM WEDNESDAY THROUGH SATURDAY,
THE COASTAL WATERS WILL BE SUSCEPTIBLE TO DEVELOPING FOG BANKS.
&&
.RIP CURRENTS...
PROBABLY GOING LOW RISK TODAY. THE RISK MAY SHIFT UP TO MDT IN NJ
IF THE SE WIND CAN INCREASE PAST 15 KT THIS AFTN.
WILL OFFER AN OUTLOOK FOR THE REST OF THE WEEK AT 5AM.
RIP CURRENT AWARENESS WEEK IS JUNE 2-8.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM EDT
WEDNESDAY FOR ANZ453>455.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...DRAG
SHORT TERM...DRAG
LONG TERM...O`HARA
AVIATION...DRAG/O`HARA
MARINE...DRAG/O`HARA
RIP CURRENTS...DRAG
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
201 AM EDT TUE MAY 28 2013
.SYNOPSIS...
HIGH PRESSURE HAS MOVED OFF THE MID ATLANTIC COAST. A WARM FRONT
DEVELOPING FROM THE OHIO VALLEY TO THE DELMARVA IS FORECAST TO MOVE
NORTHEAST THROUGH OUR REGION TONIGHT. A RIDGE OF WARM HIGH PRESSURE
TO OUR SOUTH WILL GOVERN OUR WEATHER WEDNESDAY THROUGH SUNDAY. A
COLD FRONT FROM THE NORTHWEST IS ANTICIPATED TO ARRIVE ON MONDAY.
&&
.NEAR TERM /THROUGH TODAY/...
WAA CLOUD COVER WELL IN ADVANCE OF AN ACTIVE WARM FRONT AND ALSO
IN THE RRQ OF THE 250MB NW FLOW 80-90KT SPEED MAX ROUGHLY CENTERED OVER
LONG ISLAND IS RESPONSIBLE FOR OVERNIGHT TEMPERATURES NEARLY 10 DEGREES
WARMER THAN EARLY THIS PAST MONDAY MORNING WHEN SPOTTY FROST APPEARED
TO HAVE OCCURRED FROM THE POCONOS TO SUSSEX AND WARREN COUNTIES IN
NJ.
TODAY-TUESDAY...IT LOOKS AS THOUGH THE CONVECTIVE MODELS FROM NCEP
HAVE AGAIN PREVAILED WHEN COMPARED TO YDYS 00Z/27 CYCLE OF THE
RGEM/GGEM/ECMWF/UKMET. A DECENT SLUG OF SHOWERS IS FORECAST TODAY
WITH A N/S BAND OF BRIEFLY MDT TO BRIEFLY RAIN SWEEPING EWD WITHIN
THE GROWING AREA OF RAIN ACROSS PA/NJ. THE 00Z/28 SPC WRF IS TO MY
OVERALL LIKING AND IS MATCHED PRETTY WELL BY THE RAP WHICH DOESNT
GIVE ANY POTENTIAL FOR THUNDER TIL VERY LATE THIS AFTN..IF AT
ALL...IN SE PA/MD.
THE DRIVERS ARE THE RRQ OF THE AFOREMENTIONED NW FLOW UPPER LVL
JET SPEED MAX MOVING E OF CAPE COD AND THE INSTABILITY BURST DRIVEN
ASSOCIATED WITH AND DRIVEN BY A 35-40 KT WLY 700MB SPEED MAX
(MOISTURE TRANSPORT) MOVING ACROSS PA WITH SW FLOW AT 850 MB
AIDING LIFT. THE MOST PERSISTENT AND WIDESPREAD SHOWERS WITHOUT
THUNDER SHOULD OCCUR NJ/PA NEAR THE AXIS OF THE 700MB JET SPEED
MAX HOWEVER...THERE IS A CHANCE FOR A CONVECTIVE THUNDER OUTBREAK
NEAR THE MASON DIXON LINE LATE THIS AFTN WHERE IT WILL HEAT UP
WITH ABOUT 600J OF ML CAPE.
REGARDING MOISTURE: THE PWAT AT 03Z/28 (11PM MONDAY) WAS ABOUT
ONE HALF INCH AND IS MODELED TO INCREASE TO 1.5 INCHES BY LATE
THIS TUE AFTN!
TEMPS WINDS AND DEWPOINTS ARE BLENDED 00Z/28 NCEP MOS GUIDANCE AND
HIGH TEMPS COULD BE ERRONEOUS BY 5 DEGREES DEPENDING ON WHETHER
ITS RAINING MUCH OF THE TIME BETWEEN 11 AM AND 5 PM.
THE SFC WARM FRONT WILL EVOLVE NEWD AND BY 21Z LIE ROUGHLY FROM
KDMH TO KMIV.
LATEST COSPA...RAP-RUC AS WELL AS 00Z/28 SPC WRF ARE USED TO
ASSIST IN THE FCST AND TIMING!
2800 AND 2806Z HPC QPF WILL ALSO BE UTILIZED.
&&
.SHORT TERM /TONIGHT/...
SHOWERS WITH ISOLATED TSTMS ARE POSSIBLE PRIOR TO 06Z BUT MY
CONFIDENCE ON TONIGHTS SCENARIO IS BELOW AVERAGE. MOST OF THE
RAINFALL SHOULD BE PRIOR TO 00Z/29. THERE IS A SMALL CHANCE WE`LL
NEED TO ISSUE AN SPS FOR A GROUP OF TSTMS...POSSIBLY A SEWD MOVING
CONVECTIVE BAND CROSSING CHES BAY EARLY THIS TUE EVENING AND THEN
ANOTHER EWD MOVING CONVECTIVE CLUSTER IN THE 35C KI ACROSS NNJ
AROUND 06Z?
TEMPS/WINDS/DEWPOINTS ARE 50 50 BLENDED 00Z/28 NCEP MOS MET/MAV
GUIDANCE.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
A MID LEVEL RIDGE WILL BUILD TOWARD OUR REGION FROM THE WEST
DURING THE PERIOD FROM TUESDAY NIGHT THROUGH THURSDAY NIGHT. THE
RIDGE IS EXPECTED TO CREST OVERHEAD ON FRIDAY AND IT WILL LIKELY
INFLUENCE OUR WEATHER INTO THE WEEKEND. A MID LEVEL TROUGH IS
ANTICIPATED TO PASS ACROSS THE GREAT LAKES ON SUNDAY AND IT SHOULD
REACH THE NORTHEASTERN STATES ON MONDAY.
AS THE MID LEVEL IMPULSE PASSES TO OUR EAST ON WEDNESDAY MORNING,
THE SHOWERS AND CLOUDS ARE EXPECT TO FOLLOW. WE ARE ANTICIPATING
SOME CLEARING FOR WEDNESDAY. AS CONDITIONS DESTABILIZE DURING THE
AFTERNOON HOURS THERE MAY BE SCATTERED TO ISOLATED THUNDERSTORMS,
ESPECIALLY ALONG THE INTERSTATE 95 CORRIDOR AND AT POINTS TO THE
NORTHWEST. CONDITIONS ARE EXPECTED TO REMAIN FAIRLY STABLE NEAR
THE COAST AND OVER THE RELATIVELY COOL WATER.
THE POTENTIAL FOR THE FIRST HEAT WAVE OF THE SEASON CONTINUES TO
EXIST FOR WEDNESDAY THROUGH SUNDAY IN MUCH OF OUR REGION. WARM
TEMPERATURES AT 850 HPA, MAINLY IN THE +15C TO +17C RANGE, ARE
EXPECTED TO ARRIVE ON WEDNESDAY AND THEY SHOULD REMAIN OVERHEAD
THROUGH SUNDAY. THE WARMEST OF THE AIR WITH 850 HPA TEMPERATURES
NEAR +18C ARE FORECAST TO BE OVER OUR REGION IN THE FRIDAY INTO
SATURDAY TIME FRAME AS THE MID LEVEL RIDGE CRESTS OVERHEAD.
DAYTIME MAXIMUM TEMPERATURES AROUND 90 DEGREES ARE ANTICIPATED
EACH DAY EXCEPT IN THE ELEVATED TERRAIN UP NORTH AND AT AREAS
RIGHT ALONG THE COAST. WHERE TEMPERATURES REACH THE 90 DEGREE
NEIGHBORHOOD, HEAT INDEX VALUES ARE ANTICIPATED TO BE IN THE 90 TO
95 DEGREE RANGE BASED ON THE CURRENT DEW POINT FORECASTS.
OVERNIGHT MINIMUM READINGS SHOULD BE MOSTLY IN THE 60S DUE TO THE
INCREASED HUMIDITY. HIGHLY URBANIZED LOCATIONS MAY NOT GET ANY
LOWER THAN THE LOWER 70S.
CONVECTIVE DEVELOPMENT SHOULD BE RATHER LIMITED ON THURSDAY,
FRIDAY AND SATURDAY WITH THE RIDGE PASSING OVER OUR REGION. AS THE
MID LEVEL TROUGH BEGINS TO APPROACH FROM THE NORTHWEST ON SUNDAY,
WE MAY BEGIN TO SEE AN INCREASING CHANCE OF SHOWERS AND
THUNDERSTORMS DURING THE AFTERNOON HOURS, ESPECIALLY IN OUR
NORTHWESTERN COUNTIES.
A SLOW MOVING COLD FRONT, ASSOCIATED WITH THE APPROACHING MID
LEVEL TROUGH, IS FORECAST TO ARRIVE IN OUR REGION ON MONDAY. IT IS
EXPECTED TO BE ACCOMPANIED BY ADDITIONAL SHOWERS AND THUNDERSTORMS
AS IT BRINGS AN END TO THE HEAT WAVE.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
PRIOR TO 12Z TUE...VFR CIGS WITH CIGS LOWERING TO 5000 FT SE PA
AND DE IN ISOLATED SHOWERS NEAR 12Z. LIGHT WIND.
AFTER 12Z TUE...SHOWERS BECOMING WIDESPREAD KPHL NORTH BY 16Z WITH
MVFR CONDS DEVELOPING NEAR OR AFTER 17Z....POSSIBLY SPOTTY IFR
CIGS BY 00Z/29. LIGHT WIND TENDING E OR SE THIS AFTN EXCEPT BECOMING
SLY KMIV SOUTHWARD LATE IN THE DAY.
TONIGHT...MVFR OR IFR CONDS IN ST/FOG KRDG KABE KTTN WITH MVFR CONDS
ELSEWHERE IN SC/FOG/HAZE. CHANCE OF A SHOWER. SMALL CHANCE OF A TSTM.
WIND GRADUALLY VEERING FROM SSE TO SW DURING THE NIGHT.
OUTLOOK...
EARLY WEDNESDAY MORNING...CEILING AND VISIBILITY VALUES LOWERING
TO MVFR AS A WARM FRONT WITH SHOWERS AND SCATTERED THUNDERSTORMS
LIFTS THROUGH OUR REGION.
LATE WEDNESDAY MORNING AND WEDNESDAY AFTERNOON...MAINLY VFR WITH
A CHANCE OF AFTERNOON SHOWERS AND THUNDERSTORMS, ESPECIALLY FROM
THE INTERSTATE 95 CORRIDOR NORTHWESTWARD.
WEDNESDAY NIGHT THROUGH SATURDAY...MAINLY VFR WITH POSSIBLE MVFR
CONDITIONS IN HAZE AND FOG DURING THE LATE NIGHT AND EARLY MORNING
HOURS.
&&
.MARINE...
SUB-ADVISORY CONDITIONS WILL PERSIST ACROSS OUR WATERS FOR A BETTER
PART OF TODAY. SEAS WILL SLOWLY INCREASE UPWARDS OF 4 FEET BY THIS
AFTERNOON AS A WARM FRONT LIFTS THROUGH THE REGION. WINDS ON THE
OUTER ATLC WATERS MIGHT GUST TO NEAR 25 KT LATE IN THE DAY. AN SCA
MAY BE NEEDED IN OUR 330 AM FCST FOR THE DE AND SNJ ATLC WATERS...
MAINLY FOR SEAS.
IF AN SCA IS ISSUED FOR THE S NJ AND DE WATERS...IT WILL LAST
THROUGH TONIGHT FOR G20-25 KT AND SEAS BUILDING TO 6 FT.
CONFIDENCE FOR AN SCA IN THOSE WATERS IS ROUGHLY 70 PCT.
OUTLOOK...
A WARM FRONT IS EXPECTED TO LIFT THROUGH OUR REGION ON TUESDAY
NIGHT FOLLOWED BY HIGH PRESSURE FOR WEDNESDAY THROUGH SATURDAY.
WIND SPEEDS AND WAVE HEIGHTS WILL LIKELY REMAIN BELOW THE SMALL
CRAFT ADVISORY CRITERIA THROUGH MOST OF THE PERIOD. WAVE HEIGHTS
ON OUR OCEAN WATERS MAY BUILD NEAR 5 FEET ON SATURDAY IN THE
PERSISTENT SOUTHERLY FLOW.
AS DEW POINT TEMPERATURES EXCEED THE WATER TEMPERATURES ALONG THE
COASTS OF DELAWARE AND NEW JERSEY FROM WEDNESDAY THROUGH SATURDAY,
THE COASTAL WATERS WILL BE SUSCEPTIBLE TO DEVELOPING FOG BANKS.
&&
.RIP CURRENTS...
HAVE A MDT FCST FOR NJ TODAY. WILL CHECK THIS AGAIN AT 5AM AND
OFFER AN OUTLOOK FOR THE REST OF THE WEEK.
RIP CURRENT AWARENESS WEEK IS JUNE 2-8.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DRAG/IOVINO 2A
NEAR TERM...DRAG 2A
SHORT TERM...DRAG 2A
LONG TERM...IOVINO
AVIATION...DRAG/IOVINO 2A
MARINE...DRAG/IOVINO 2A
RIP CURRENTS...2A
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
340 AM EDT Tue May 28 2013
.NEAR TERM [Through Tonight]...
Yet another fair, hot, and dry day is in store for the Tri-State
region today, with high temps once again expected to reach the
middle 80s near the coast to the lower 90s further inland. Also,
the sea breeze is expected to begin a bit earlier today, as it
will be aided by increasing low level southeasterly winds, as the
ridge of High Pressure off of the Mid-Atlantic continues to slide
further to our east. Although deep layer moisture will still be
quite limited, an isolated shower or thunderstorm cannot be ruled
out this afternoon, especially across far western portions of the
CWA, where most of the Hi-Res WRF runs are indicating some
convective development. However, given that PWATs are still only
expected to be around 1 inch, our confidence was not high enough
to include explicit PoPs at this time, but would not be surprised
if the day shift modifies this forecast slightly. For tonight,
with slightly increasing low level moisture, the chances for fog
or low clouds will be slightly higher than this morning, but
probabilities are still not high enough to include any fog in the
grids. However, this will change for Wednesday Night and Thursday
Morning.
&&
.SHORT TERM [Wednesday Through Thursday]...
High pressure will remain centered off the Southeast U.S. coast
and ridge westward across Dixie with the axis mainly north of the
forecast area through this period. We will continue to see a very
gradual moistening trend with isolated sea breeze showers or
thunderstorms possible each afternoon. Daytime temps have been
running above guidance and will remain a bit above seasonal
levels. Look for highs in the lower 90s and overnight lows in the
mid 60 to around 70 inland and in the lower to mid 70s at the
coast.
&&
.LONG TERM [Thursday Night through Monday]...
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 12 UTC Wednesday] VFR conditions are expected to prevail at
the terminals for the overnight and daytime hours today, except for
the potential of MVFR Cigs at VLD, TLH, and ECP. Confidence for this
occurrence is not very high as the HRRR and NARRE are not in their
usual good agreement, but the MAV guidance does support a brief
period of 2500ft Cigs. The models are, however, in very good
agreement about fog potential, and they have backed off
substantially from this time last night to a high confidence of
VFR as the air mass is remaining quite dry. Chances for MVFR to
potentially IFR conditions may be a bit higher for late tonight
and Wednesday morning, so may hint in the MVFR direction.
&&
.MARINE...
A ridge of high pressure will remain along or north of the Gulf
Coast through the period with a prolonged period of easterly flow
continuing. As is typical in this flow regime, there will be periods
where wind speeds surge to cautionary or marginal advisory levels,
mainly during the overnight and morning hours each day.
&&
.FIRE WEATHER...
With low level moisture gradually on the increase, no Red Flag
concerns are expected for the next several days. However, with
relatively high mixing heights and increasing transport wind speeds,
dispersions are expected to be high across parts of the Tri-State
area.
&&
.HYDROLOGY...
Overall chances for and coverage of showers and thunderstorms will
be low through the weekend with no impacts to area rivers expected.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 92 68 91 70 92 / 0 0 10 10 20
Panama City 85 73 88 73 89 / 10 0 20 10 10
Dothan 91 65 92 68 91 / 10 10 10 10 20
Albany 91 65 92 68 92 / 0 0 10 10 10
Valdosta 92 65 92 67 91 / 0 0 20 10 20
Cross City 91 67 91 67 92 / 10 10 30 10 20
Apalachicola 84 72 87 73 88 / 10 0 10 10 10
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
Near Term/Aviation/Fire Weather...Gould
Long Term...Lahr/Godsey
Rest of Discussion...Wool
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
800 PM EDT WED MAY 29 2013
.UPDATE...
NO CHANGES PLANNED FOR THE FORECAST EXCEPT SOME MINOR TWEAKS TO SKY
COVER.
41
.PREVIOUS...
.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...
00Z UPDATE...
MOIST EASTERLY FLOW WILL CONTINUE ACROSS THE AREA. EXPECT CEILINGS
TO FORM IN THE 008 TO 010 RANGE FROM 10Z TO 14Z...GRADUALLY
SCATTERING OUT TO VFR AFTER 17Z. NO CONVECTION EXPECTED THROUGH THE
PERIOD. VARIABLE TO LIGHT SOUTHEAST WINDS OVERNIGHT BECOMING EAST
SOUTHEAST 8 TO 10KT AFTER 14Z THURSDAY.
//ATL CONFIDENCE...00Z UPDATE...
CONFIDENCE HIGH ON ALL ELEMENTS
41
&&
.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...41
LONG TERM....BDL
AVIATION...41
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
127 AM EDT TUE MAY 28 2013
.PREV DISCUSSION... /ISSUED 900 PM EDT MON MAY 27 2013/
UPDATE...HAVE REMOVED THUNDERSTORMS FROM THE FORECAST FOR THIS
EVENING. OTHERWISE NO CHANGES.
41
PREVIOUS...
SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
LATEST RUC 50H FIELD OVERLAID ON SATELLITE WATER VAPOR IMAGERY
SHOWS SUBTLE DISTURBANCES EMBEDDED WITHIN THE NEARLY ZONAL FLOW
ALOFT. SURFACE ANALYSIS SHOWS THE SURFACE RIDGE SETTLING ALONG THE
MID ATLANTIC COAST AND ESTABLISHING A MOIST SOUTHERLY WIND FLOW THIS
AFTERNOON. A MODIFIED 12Z FFC SOUNDING AND SUPPORTED BY LATEST SPC
MESO ANALYSIS INDICATE AFTERNOON CAPES WILL TOP OUT AROUND 500-600
J/KG WITH A MODERATE MID LEVEL CAP. WEAK INSTABILITY... LACK OF DEEP
LAYER SHEAR AND FORCING SUGGEST THE GREATER CHANCE FOR ISOLATED
AFTERNOON EVENING SHOWERS AND THUNDERSTORMS WOULD BE NORTH GA WHERE
OROGRAPHIC LIFT AND SUBTLE UPPER DISTURBANCES MAY PROVIDE SUFFICIENT
FORCING FOR DEVELOPMENT. WILL CONTINUE TO SHOW ISOLATED THUNDER FOR
NORTH GA THIS AFTERNOON AND EVENING... AND ONCE AGAIN ON TUESDAY.
OTHERWISE... MODELS ARE IN GOOD AGREEMENT WITH SURFACE AND UPPER
LEVEL RIDGE BUILDING OVER THE STATE TUE-WED IN RESPONSE TO DEEPENING
LOW PRESSURE OVER THE PLAINS THROUGH MID WEEK. AS A RESULT... EXPECT
SLIGHTLY LESS OF A CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS NORTH
GA TUE AFTERNOON/EVENING... AND NIL CHANCE ON WEDNESDAY.
AS FOR TEMPS... LEANED SLIGHTLY COOLER THAN GUIDANCE FOR LOWS
TONIGHT WITH LIGHT WINDS UNDER MOSTLY CLEAR SKIES INITIALLY... ALTHO
EXPECT THE SSE FLOW TO ADVECT SOME LOW LEVEL STRATUS NORTHWARD FROM
ATLANTIC AND GULF TOWARD MORNING. THEN WENT WITH A MAV AND MET BLEND
FOR THE REMAINING PERIODS AS A WARMING TREND CONTINUES IN RESPONSE
BUILDING HIGH PRESSURE AND CONTINUED DRY CONDITIONS.
39
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
NO MAJOR CHANGES MADE TO THE EXTENDED FORECAST. THINGS CONTINUE TO
LOOK LIKE A MORE SUMMER- LIKE PATTERN DEVELOPING THIS WEEK. MODELS
IN GOOD AGREEMENT IN BUILDING THE H5 RIDGE OVER THE CWA THROUGH
THE UPCOMING WEEKEND. HIGH PRESSURE AT THE SURFACE WILL BE BECOME
CENTERED OFF THE EAST COAST. THIS WILL BRING AN EAST TO SOUTHEAST
SURFACE FLOW TO THE CWA THEREBY INCREASING HUMIDITIES THROUGH THE
WEEK. THERE COULD BE A FEW ISOLATED AFTERNOON/EVENING
THUNDERSTORMS DEVELOPING EACH AFTERNOON...BUT WITH THE H5 RIDGE
HOLDING FIRM OVER THE CWA...THIS RISK SHOULD BE LESS THAN 20
PERCENT. A COLD FRONT WILL MOVE INTO THE TENNESSEE VALLEY BY NEXT
WEEKEND AS THE UPPER RIDGE WEAKENS. AT THE SAME TIME A SHORT WAVE
MOVES INTO THE OHIO AND TENNESSEE VALLEYS. THIS WILL BRING A
SLIGHT CHANCE OF THUNDERSTORMS MAINLY TO NORTH GA SUNDAY AND
MONDAY.
01/17
&&
.AVIATION...
06Z UPDATE...
CONTINUED VFR THROUGH THE PERIOD. THERE MAY BE SOME BRIEF MVFR FOG
AT AHN/MCN BUT FOR NOW HAVE KEPT 6SM BR. SE WINDS THROUGH THE
PERIOD BELOW 5K THIS MORNING...5-10KT THIS AFTERNOON...BACK BELOW
5KT TONIGHT ALL BUT ATL. MAY SEE FEW AFTERNOON CU 5-7KFT BUT FOR
THE MOST PART ANY CLOUDS WILL BE MID-LEVEL.
//ATL CONFIDENCE...06Z UPDATE...
HIGH ON ALL ELEMENTS.
TDP
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 87 60 87 63 / 0 0 5 10
ATLANTA 86 65 86 66 / 0 0 5 10
BLAIRSVILLE 83 57 82 58 / 5 5 5 10
CARTERSVILLE 87 62 88 63 / 0 0 5 10
COLUMBUS 88 64 89 67 / 0 0 5 10
GAINESVILLE 87 61 85 63 / 5 5 5 10
MACON 88 62 89 64 / 0 0 5 10
ROME 88 62 90 62 / 5 5 5 10
PEACHTREE CITY 86 59 86 62 / 0 0 5 10
VIDALIA 89 64 88 66 / 0 0 5 10
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
324 PM CDT TUE MAY 28 2013
.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
&&
.AVIATION...
ISSUED 1244 PM CDT TUE MAY 28 2013
CONVECTION FROM EARLY THIS MORNING HAS CLEARED THE CENTRAL
ILLINOIS TERMINALS...LEAVING BEHIND A 4000-8000FT MID-LEVEL
OVERCAST. CLOUDS WILL CONTINUE TO THIN THIS AFTERNOON...ALLOWING
THE ATMOSPHERE TO DESTABILIZE AND SCATTERED THUNDERSTORMS TO
DEVELOP. STILL SOME UNCERTAINTIES AS TO EXACTLY WHERE STORMS WILL
FIRE...BUT MOST LIKELY SCENARIO PLACES THEM FURTHER
NORTH/NORTHWEST NEAR STATIONARY FRONTAL BOUNDARY ACROSS IOWA INTO
FAR NORTHERN ILLINOIS. HRRR HAS BEEN CONSISTENTLY SHOWING
CONVECTION DEVELOPING SOUTH OF THE FRONT FROM NORTHERN MISSOURI
E/NE TO THE I-80 CORRIDOR AFTER 20Z FOR THE PAST SEVERAL RUNS.
STORMS ARE EXPECTED TO GRADUALLY DEVELOP/SHIFT FURTHER EASTWARD
ACROSS NORTH-CENTRAL ILLINOIS THIS EVENING. HAVE THEREFORE
INCLUDED VCTS AT KPIA AND KBMI BETWEEN 00Z AND 05Z. FURTHER SOUTH
AT THE REMAINING TAF SITES...HAVE FEATURED THUNDER BETWEEN 02Z AND
09Z. WINDS WILL BE QUITE STRONG/GUSTY THIS AFTERNOON...AS LOW-LEVEL
JET MIXES TO THE SURFACE. SOUTHERLY WINDS WILL GUST TO BETWEEN 25
AND 30KT AT TIMES THROUGH THE AFTERNOON...BEFORE DIMINISHING TO
BETWEEN 10 AND 15KT TONIGHT.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH WEDNESDAY MORNING FOR ILZ027>031-
036>038-040>043-047>053-061.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1245 PM CDT TUE MAY 28 2013
.DISCUSSION...
ISSUED 1044 AM CDT TUE MAY 28 2013
THUNDERSTORM COMPLEX THAT PUSHED INTO WEST-CENTRAL ILLINOIS EARLY
THIS MORNING HAS WEAKENED CONSIDERABLY OVER THE PAST COUPLE OF
HOURS. 15Z/10AM RADAR MOSAIC SHOWS LINGERING CONVECTION JUST SOUTH
OF THE KILX CWA IN THE SAINT LOUIS METRO AREA. FURTHER
NORTH...ONLY A FEW SCATTERED SHOWERS LINGER EAST OF I-55. THANKS
TO EXTENSIVE CLOUD COVER...LAPS DATA SHOWS A STABLE LOW-LEVEL
AIRMASS IN PLACE...WITH CAPE VALUES OF LESS THAN 500J/KG. BREAKS
IN THE OVERCAST UPSTREAM OVER IOWA/MISSOURI WILL WORK EASTWARD
OVER THE NEXT FEW HOURS...WITH PARTLY TO MOSTLY CLOUDY SKIES
EXPECTED THIS AFTERNOON. PARTIAL SUNSHINE WILL ALLOW THE AIRMASS
TO DESTABILIZE THIS AFTERNOON...WITH SCATTERED THUNDERSTORMS
RE-DEVELOPING. CONVECTION SHOULD BE MOST NUMEROUS FURTHER NORTH
CLOSER TO SYNOPTIC FRONTAL BOUNDARY DRAPED ACROSS IOWA INTO
NORTHERN ILLINOIS. AS SUCH...WILL INCLUDE HIGH CHANCE POPS ACROSS
THE FAR NORTHERN CWA THIS AFTERNOON...TAPERING DOWN TO JUST
SLIGHT CHANCE POPS ALONG/SOUTH OF I-70. LOCALLY HEAVY RAINFALL WILL
BE POSSIBLE WITH ANY STORMS THAT DEVELOP...SO FLASH FLOOD WATCH
REMAINS IN EFFECT THROUGH 7 PM FOR ALL LOCATIONS ALONG/WEST OF A
BLOOMINGTON TO SHELBYVILLE LINE. ZONE UPDATE WILL BE ISSUED
SHORTLY.
&&
.AVIATION...
ISSUED 1244 PM CDT TUE MAY 28 2013
CONVECTION FROM EARLY THIS MORNING HAS CLEARED THE CENTRAL
ILLINOIS TERMINALS...LEAVING BEHIND A 4000-8000FT MID-LEVEL
OVERCAST. CLOUDS WILL CONTINUE TO THIN THIS AFTERNOON...ALLOWING
THE ATMOSPHERE TO DESTABILIZE AND SCATTERED THUNDERSTORMS TO
DEVELOP. STILL SOME UNCERTAINTIES AS TO EXACTLY WHERE STORMS WILL
FIRE...BUT MOST LIKELY SCENARIO PLACES THEM FURTHER
NORTH/NORTHWEST NEAR STATIONARY FRONTAL BOUNDARY ACROSS IOWA INTO
FAR NORTHERN ILLINOIS. HRRR HAS BEEN CONSISTENTLY SHOWING
CONVECTION DEVELOPING SOUTH OF THE FRONT FROM NORTHERN MISSOURI
E/NE TO THE I-80 CORRIDOR AFTER 20Z FOR THE PAST SEVERAL RUNS.
STORMS ARE EXPECTED TO GRADUALLY DEVELOP/SHIFT FURTHER EASTWARD
ACROSS NORTH-CENTRAL ILLINOIS THIS EVENING. HAVE THEREFORE
INCLUDED VCTS AT KPIA AND KBMI BETWEEN 00Z AND 05Z. FURTHER SOUTH
AT THE REMAINING TAF SITES...HAVE FEATURED THUNDER BETWEEN 02Z AND
09Z. WINDS WILL BE QUITE STRONG/GUSTY THIS AFTERNOON...AS LOW-LEVEL
JET MIXES TO THE SURFACE. SOUTHERLY WINDS WILL GUST TO BETWEEN 25
AND 30KT AT TIMES THROUGH THE AFTERNOON...BEFORE DIMINISHING TO
BETWEEN 10 AND 15KT TONIGHT.
BARNES
&&
.PREV DISCUSSION...
ISSUED 321 AM CDT TUE MAY 28 2013
SHORT TERM...TODAY THROUGH WEDNESDAY
WARM FRONT AT 07Z HAD LIFTED NORTH OF THE I-80 CORRIDOR WITH
S/SE WINDS SOUTH OF THE BOUNDARY ADVECTING LOW 60S DEWPOINTS INTO
THE CWA. IMPRESSIVE FORWARD PROPAGATING MCS MOVING INTO NE MO
HAD A LARGE AREA OF COLD CLOUD TOPS AT -60C OR LESS PAST FEW
HOURS. THIS MCS WAS BEING MAINTAINED BY A 55-65 KT SW 850MB JET WHICH
TAPPED INTO A 15-17C DEWPOINT POOL OVER THE PLAINS. FIRST FORECAST
ISSUE WILL BE THE IMPACT OF THIS MCS ON THE CWA THIS MORNING.
AWIPS DISTANCE/SPEED TOOL TAKES THE LEADING EDGE INTO THE FAR
WESTERN CWA JUST BEFORE 10Z/5AM. LATEST HRRR AND 4KM NSSL WRF
SEEMED TO HAVE THE BEST HANDLE ON THIS SYSTEM AND BOTH SHOW
CONVECTION MAINTAINING INTENSITY AT LEAST THROUGH THE WESTERN HALF
OF THE CWA THROUGH 12-13Z. STRONG 850MB MOISTURE TRANSPORT FEED IN
FROM THE SW TO KEEP HEAVY RAIN RATES OF 1.5 IN/HR WHICH COULD LEAD TO
ANOTHER ROUND OF FLASH FLOODING...ESPECIALLY IF FORWARD SPEED
SLOWS OR TRAINING DEVELOPS. WILL NEED TO EXTEND THE CURRENT FLASH
FLOOD WATCH THROUGH 00Z. SEVERE WIND GUSTS WILL ALSO NEED TO BE
MONITORED FOR THE NEXT FEW HOURS...AS LATEST SPC MESO-ANALYSIS
SHOWS AN AREA OF 1K DCAPE SHIFTING INTO WEST CENTRAL IL. KIRK IN
NE MO RECENTLY REPORTED A GUST OF 57 KTS ON THE LEADING EDGE OF
THIS LINE.
SECONDARY FORECAST CONCERN IS POSSIBLE SVR CONVECTION THIS
AFTERNOON FORMING ALONG REMNANT MESOSCALE BOUNDARIES. FORECAST
SOUNDINGS SHOW LITTLE IN THE WAY OF CINH...AND WITH AFTERNOON
HEATING SFC BASED CAPES OF 2000-2500 J/KG AND 40KTS 0-6KM BULK
SHEAR WOULD SUPPORT SEVERE STORMS. OF COURSE QUESTION MARKS
REVOLVE AROUND STABILIZING EFFECTS OF MORNING MCS AND RECOVERY.
SPC HAS EXPANDED DAY 1 SLIGHT RISK TO INCLUDE AREAS NORTH OF I-70.
FOR TONIGHT...POTENTIAL IS THERE FOR ANOTHER MCS TO FORM NEAR THE
IA/MO BORDER REGION AND SHIFT EAST AFFECTING MAINLY THE NORTHERN
CWA INTO EARLY WEDNESDAY MORNING.
BY WEDNESDAY UPPER LEVEL RIDGING TEMPORARILY BUILDS OVER THE AREA
SHIFTING THE MAIN STORM PATH NORTH. LOW PRESSURE DEVELOPING OVER
THE PLAINS WILL TIGHTEN UP THE MSLP GRADIENT CAUSING SOUTH WINDS
TO GUST AROUND 30 MPH. THIS COMBINED WITH SOME SUN SHOULD PRODUCE
A VERY WARM DAY WITH HIGHS IN THE MID/UPPER 80S.
LONG TERM...THURSDAY THROUGH MONDAY
THURSDAY AND FRIDAY...CLOSED UPPER LOW SHIFTING INTO THE NORTHERN
PLAINS BRINGS A DIFLUENT SOUTHWEST MID LEVEL FLOW OVER THE
MIDWEST. LEAD SHORTWAVES RIPPLING THROUGH IN THIS FLOW WILL ACT
ON A HIGH P/W ATMOSPHERE FOR SEVERAL ROUND OF SHOWERS AND STORMS.
LOCALLY HEAVY RAIN AND SEVERE STORMS WILL BE POSSIBLE.
BY SATURDAY THE UPPER LOW BEGINS TO OPEN UP AND SHIFT
SOUTHEAST...HELPING EASE A COLD FRONT INTO THE AREA. MEDIUM RANGE
MODELS SHOW THIS TO BE A SLOW PROCESS...WITH MULTIPLE ROUNDS OF
THUNDERSTORMS LIKELY AS THE FRONT DRIFTS ACROSS THE CWA SATURDAY
AND SATURDAY NIGHT. AGAIN...SYNOPTIC SETUP FAVORS MORE LOCALLY
HEAVY RAIN AND STRONG TO SEVERE CONVECTION.
SUNDAY AND MONDAY...THE UPPER TROF SHIFTS ACROSS THE MIDWEST AND
GREAT LAKES...BRINGING A RETURN TO COOLER AND DRIER WEATHER.
25
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 7 PM CDT THIS EVENING FOR ILZ027>031-
036>038-040>043-047>053-061.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1044 AM CDT TUE MAY 28 2013
.DISCUSSION...
ISSUED 1044 AM CDT TUE MAY 28 2013
THUNDERSTORM COMPLEX THAT PUSHED INTO WEST-CENTRAL ILLINOIS EARLY
THIS MORNING HAS WEAKENED CONSIDERABLY OVER THE PAST COUPLE OF
HOURS. 15Z/10AM RADAR MOSAIC SHOWS LINGERING CONVECTION JUST SOUTH
OF THE KILX CWA IN THE SAINT LOUIS METRO AREA. FURTHER
NORTH...ONLY A FEW SCATTERED SHOWERS LINGER EAST OF I-55. THANKS
TO EXTENSIVE CLOUD COVER...LAPS DATA SHOWS A STABLE LOW-LEVEL
AIRMASS IN PLACE...WITH CAPE VALUES OF LESS THAN 500J/KG. BREAKS
IN THE OVERCAST UPSTREAM OVER IOWA/MISSOURI WILL WORK EASTWARD
OVER THE NEXT FEW HOURS...WITH PARTLY TO MOSTLY CLOUDY SKIES
EXPECTED THIS AFTERNOON. PARTIAL SUNSHINE WILL ALLOW THE AIRMASS
TO DESTABILIZE THIS AFTERNOON...WITH SCATTERED THUNDERSTORMS
RE-DEVELOPING. CONVECTION SHOULD BE MOST NUMEROUS FURTHER NORTH
CLOSER TO SYNOPTIC FRONTAL BOUNDARY DRAPED ACROSS IOWA INTO
NORTHERN ILLINOIS. AS SUCH...WILL INCLUDE HIGH CHANCE POPS ACROSS
THE FAR NORTHERN CWA THIS AFTERNOON...TAPERING DOWN TO JUST
SLIGHT CHANCE POPS ALONG/SOUTH OF I-70. LOCALLY HEAVY RAINFALL WILL
BE POSSIBLE WITH ANY STORMS THAT DEVELOP...SO FLASH FLOOD WATCH
REMAINS IN EFFECT THROUGH 7 PM FOR ALL LOCATIONS ALONG/WEST OF A
BLOOMINGTON TO SHELBYVILLE LINE. ZONE UPDATE WILL BE ISSUED
SHORTLY.
BARNES
&&
.AVIATION...
ISSUED 645 AM CDT TUE MAY 28 2013
ONGOING CONVECTION AT 12Z WILL MOSTLY PASS ACROSS THE TERMINAL
SITES BY 15Z-16Z WITH VFR CONDITIONS IN LIGHT RAIN AND ISOLATED
THUNDER. A BRIEF PERIOD OF MVFR WILL BE POSSIBLE IF ANY STORM
PASSES DIRECTLY OVER A TERMINAL SITE.
SINCE THE WARM FRONT HAS FINALLY PUSHED NORTH OF OUR
COUNTIES...WINDS WILL BE INCREASING FROM THE SOUTHWEST WITH
SUSTAINED IN THE 14-18KT RANGE AND GUSTS TO 26-28KT. WINDS WILL
DIMINISH THIS EVENING OUTSIDE OF THE NEXT STORM COMPLEX THAT IS
EXPECTED TO MOVE THROUGH CENTRAL IL LATE THIS AFTERNOON AND THIS
EVENING. WE JUST ACKNOWLEDGED THAT NEXT LINE OF STORMS WITH A
VCTS...AS TIMING IS A TOUGH CALL UNTIL CONVECTIVE INITIATION IS
REACHED AT SOME POINT THIS AFTERNOON.
DRY CONDITIONS SHOULD RETURN BY MIDNIGHT IN ALL BUT THE FAR
NORTHERN AREAS. HOWEVER...SOME LIGHT FOG MAY BEGIN TO DEVELOP IF
WINDS WEAKEN BY SUNRISE ON WEDNESDAY. CONFIDENCE IS LOW THAT WINDS
WILL GO LIGHT ENOUGH FOR FOG TO BECOME AN ISSUE...SO FOG WAS LEFT
OFF THIS SET OF TAFS.
SHIMON
&&
.PREV DISCUSSION...
ISSUED 321 AM CDT TUE MAY 28 2013
SHORT TERM...TODAY THROUGH WEDNESDAY
WARM FRONT AT 07Z HAD LIFTED NORTH OF THE I-80 CORRIDOR WITH
S/SE WINDS SOUTH OF THE BOUNDARY ADVECTING LOW 60S DEWPOINTS INTO
THE CWA. IMPRESSIVE FORWARD PROPAGATING MCS MOVING INTO NE MO
HAD A LARGE AREA OF COLD CLOUD TOPS AT -60C OR LESS PAST FEW
HOURS. THIS MCS WAS BEING MAINTAINED BY A 55-65 KT SW 850MB JET WHICH
TAPPED INTO A 15-17C DEWPOINT POOL OVER THE PLAINS. FIRST FORECAST
ISSUE WILL BE THE IMPACT OF THIS MCS ON THE CWA THIS MORNING.
AWIPS DISTANCE/SPEED TOOL TAKES THE LEADING EDGE INTO THE FAR
WESTERN CWA JUST BEFORE 10Z/5AM. LATEST HRRR AND 4KM NSSL WRF
SEEMED TO HAVE THE BEST HANDLE ON THIS SYSTEM AND BOTH SHOW
CONVECTION MAINTAINING INTENSITY AT LEAST THROUGH THE WESTERN HALF
OF THE CWA THROUGH 12-13Z. STRONG 850MB MOISTURE TRANSPORT FEED IN
FROM THE SW TO KEEP HEAVY RAIN RATES OF 1.5 IN/HR WHICH COULD LEAD TO
ANOTHER ROUND OF FLASH FLOODING...ESPECIALLY IF FORWARD SPEED
SLOWS OR TRAINING DEVELOPS. WILL NEED TO EXTEND THE CURRENT FLASH
FLOOD WATCH THROUGH 00Z. SEVERE WIND GUSTS WILL ALSO NEED TO BE
MONITORED FOR THE NEXT FEW HOURS...AS LATEST SPC MESO-ANALYSIS
SHOWS AN AREA OF 1K DCAPE SHIFTING INTO WEST CENTRAL IL. KIRK IN
NE MO RECENTLY REPORTED A GUST OF 57 KTS ON THE LEADING EDGE OF
THIS LINE.
SECONDARY FORECAST CONCERN IS POSSIBLE SVR CONVECTION THIS
AFTERNOON FORMING ALONG REMNANT MESOSCALE BOUNDARIES. FORECAST
SOUNDINGS SHOW LITTLE IN THE WAY OF CINH...AND WITH AFTERNOON
HEATING SFC BASED CAPES OF 2000-2500 J/KG AND 40KTS 0-6KM BULK
SHEAR WOULD SUPPORT SEVERE STORMS. OF COURSE QUESTION MARKS
REVOLVE AROUND STABILIZING EFFECTS OF MORNING MCS AND RECOVERY.
SPC HAS EXPANDED DAY 1 SLIGHT RISK TO INCLUDE AREAS NORTH OF I-70.
FOR TONIGHT...POTENTIAL IS THERE FOR ANOTHER MCS TO FORM NEAR THE
IA/MO BORDER REGION AND SHIFT EAST AFFECTING MAINLY THE NORTHERN
CWA INTO EARLY WEDNESDAY MORNING.
BY WEDNESDAY UPPER LEVEL RIDGING TEMPORARILY BUILDS OVER THE AREA
SHIFTING THE MAIN STORM PATH NORTH. LOW PRESSURE DEVELOPING OVER
THE PLAINS WILL TIGHTEN UP THE MSLP GRADIENT CAUSING SOUTH WINDS
TO GUST AROUND 30 MPH. THIS COMBINED WITH SOME SUN SHOULD PRODUCE
A VERY WARM DAY WITH HIGHS IN THE MID/UPPER 80S.
LONG TERM...THURSDAY THROUGH MONDAY
THURSDAY AND FRIDAY...CLOSED UPPER LOW SHIFTING INTO THE NORTHERN
PLAINS BRINGS A DIFLUENT SOUTHWEST MID LEVEL FLOW OVER THE
MIDWEST. LEAD SHORTWAVES RIPPLING THROUGH IN THIS FLOW WILL ACT
ON A HIGH P/W ATMOSPHERE FOR SEVERAL ROUND OF SHOWERS AND STORMS.
LOCALLY HEAVY RAIN AND SEVERE STORMS WILL BE POSSIBLE.
BY SATURDAY THE UPPER LOW BEGINS TO OPEN UP AND SHIFT
SOUTHEAST...HELPING EASE A COLD FRONT INTO THE AREA. MEDIUM RANGE
MODELS SHOW THIS TO BE A SLOW PROCESS...WITH MULTIPLE ROUNDS OF
THUNDERSTORMS LIKELY AS THE FRONT DRIFTS ACROSS THE CWA SATURDAY
AND SATURDAY NIGHT. AGAIN...SYNOPTIC SETUP FAVORS MORE LOCALLY
HEAVY RAIN AND STRONG TO SEVERE CONVECTION.
SUNDAY AND MONDAY...THE UPPER TROF SHIFTS ACROSS THE MIDWEST AND
GREAT LAKES...BRINGING A RETURN TO COOLER AND DRIER WEATHER.
25
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 7 PM CDT THIS EVENING FOR ILZ027>031-
036>038-040>043-047>053-061.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
645 AM CDT TUE MAY 28 2013
.DISCUSSION...
ISSUED 321 AM CDT TUE MAY 28 2013
SHORT TERM...TODAY THROUGH WEDNESDAY
WARM FRONT AT 07Z HAD LIFTED NORTH OF THE I-80 CORRIDOR WITH
S/SE WINDS SOUTH OF THE BOUNDARY ADVECTING LOW 60S DEWPOINTS INTO
THE CWA. IMPRESSIVE FORWARD PROPAGATING MCS MOVING INTO NE MO
HAD A LARGE AREA OF COLD CLOUD TOPS AT -60C OR LESS PAST FEW
HOURS. THIS MCS WAS BEING MAINTAINED BY A 55-65 KT SW 850MB JET WHICH
TAPPED INTO A 15-17C DEWPOINT POOL OVER THE PLAINS. FIRST FORECAST
ISSUE WILL BE THE IMPACT OF THIS MCS ON THE CWA THIS MORNING.
AWIPS DISTANCE/SPEED TOOL TAKES THE LEADING EDGE INTO THE FAR
WESTERN CWA JUST BEFORE 10Z/5AM. LATEST HRRR AND 4KM NSSL WRF
SEEMED TO HAVE THE BEST HANDLE ON THIS SYSTEM AND BOTH SHOW
CONVECTION MAINTAINING INTENSITY AT LEAST THROUGH THE WESTERN HALF
OF THE CWA THROUGH 12-13Z. STRONG 850MB MOISTURE TRANSPORT FEED IN
FROM THE SW TO KEEP HEAVY RAIN RATES OF 1.5 IN/HR WHICH COULD LEAD TO
ANOTHER ROUND OF FLASH FLOODING...ESPECIALLY IF FORWARD SPEED
SLOWS OR TRAINING DEVELOPS. WILL NEED TO EXTEND THE CURRENT FLASH
FLOOD WATCH THROUGH 00Z. SEVERE WIND GUSTS WILL ALSO NEED TO BE
MONITORED FOR THE NEXT FEW HOURS...AS LATEST SPC MESO-ANALYSIS
SHOWS AN AREA OF 1K DCAPE SHIFTING INTO WEST CENTRAL IL. KIRK IN
NE MO RECENTLY REPORTED A GUST OF 57 KTS ON THE LEADING EDGE OF
THIS LINE.
SECONDARY FORECAST CONCERN IS POSSIBLE SVR CONVECTION THIS
AFTERNOON FORMING ALONG REMNANT MESOSCALE BOUNDARIES. FORECAST
SOUNDINGS SHOW LITTLE IN THE WAY OF CINH...AND WITH AFTERNOON
HEATING SFC BASED CAPES OF 2000-2500 J/KG AND 40KTS 0-6KM BULK
SHEAR WOULD SUPPORT SEVERE STORMS. OF COURSE QUESTION MARKS
REVOLVE AROUND STABILIZING EFFECTS OF MORNING MCS AND RECOVERY.
SPC HAS EXPANDED DAY 1 SLIGHT RISK TO INCLUDE AREAS NORTH OF I-70.
FOR TONIGHT...POTENTIAL IS THERE FOR ANOTHER MCS TO FORM NEAR THE
IA/MO BORDER REGION AND SHIFT EAST AFFECTING MAINLY THE NORTHERN
CWA INTO EARLY WEDNESDAY MORNING.
BY WEDNESDAY UPPER LEVEL RIDGING TEMPORARILY BUILDS OVER THE AREA
SHIFTING THE MAIN STORM PATH NORTH. LOW PRESSURE DEVELOPING OVER
THE PLAINS WILL TIGHTEN UP THE MSLP GRADIENT CAUSING SOUTH WINDS
TO GUST AROUND 30 MPH. THIS COMBINED WITH SOME SUN SHOULD PRODUCE
A VERY WARM DAY WITH HIGHS IN THE MID/UPPER 80S.
LONG TERM...THURSDAY THROUGH MONDAY
THURSDAY AND FRIDAY...CLOSED UPPER LOW SHIFTING INTO THE NORTHERN
PLAINS BRINGS A DIFLUENT SOUTHWEST MID LEVEL FLOW OVER THE
MIDWEST. LEAD SHORTWAVES RIPPLING THROUGH IN THIS FLOW WILL ACT
ON A HIGH P/W ATMOSPHERE FOR SEVERAL ROUND OF SHOWERS AND STORMS.
LOCALLY HEAVY RAIN AND SEVERE STORMS WILL BE POSSIBLE.
BY SATURDAY THE UPPER LOW BEGINS TO OPEN UP AND SHIFT
SOUTHEAST...HELPING EASE A COLD FRONT INTO THE AREA. MEDIUM RANGE
MODELS SHOW THIS TO BE A SLOW PROCESS...WITH MULTIPLE ROUNDS OF
THUNDERSTORMS LIKELY AS THE FRONT DRIFTS ACROSS THE CWA SATURDAY
AND SATURDAY NIGHT. AGAIN...SYNOPTIC SETUP FAVORS MORE LOCALLY
HEAVY RAIN AND STRONG TO SEVERE CONVECTION.
SUNDAY AND MONDAY...THE UPPER TROF SHIFTS ACROSS THE MIDWEST AND
GREAT LAKES...BRINGING A RETURN TO COOLER AND DRIER WEATHER.
25
&&
.AVIATION...
ISSUED 645 AM CDT TUE MAY 28 2013
ONGOING CONVECTION AT 12Z WILL MOSTLY PASS ACROSS THE TERMINAL
SITES BY 15Z-16Z WITH VFR CONDITIONS IN LIGHT RAIN AND ISOLATED
THUNDER. A BRIEF PERIOD OF MVFR WILL BE POSSIBLE IF ANY STORM
PASSES DIRECTLY OVER A TERMINAL SITE.
SINCE THE WARM FRONT HAS FINALLY PUSHED NORTH OF OUR
COUNTIES...WINDS WILL BE INCREASING FROM THE SOUTHWEST WITH
SUSTAINED IN THE 14-18KT RANGE AND GUSTS TO 26-28KT. WINDS WILL
DIMINISH THIS EVENING OUTSIDE OF THE NEXT STORM COMPLEX THAT IS
EXPECTED TO MOVE THROUGH CENTRAL IL LATE THIS AFTERNOON AND THIS
EVENING. WE JUST ACKNOWLEDGED THAT NEXT LINE OF STORMS WITH A
VCTS...AS TIMING IS A TOUGH CALL UNTIL CONVECTIVE INITIATION IS
REACHED AT SOME POINT THIS AFTERNOON.
DRY CONDITIONS SHOULD RETURN BY MIDNIGHT IN ALL BUT THE FAR
NORTHERN AREAS. HOWEVER...SOME LIGHT FOG MAY BEGIN TO DEVELOP IF
WINDS WEAKEN BY SUNRISE ON WEDNESDAY. CONFIDENCE IS LOW THAT WINDS
WILL GO LIGHT ENOUGH FOR FOG TO BECOME AN ISSUE...SO FOG WAS LEFT
OFF THIS SET OF TAFS.
SHIMON
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS EVENING FOR ILZ027>031-036>038-
040>043-047>053-061.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
321 AM CDT TUE MAY 28 2013
.DISCUSSION...
ISSUED 321 AM CDT TUE MAY 28 2013
SHORT TERM...TODAY THROUGH WEDNESDAY
WARM FRONT AT 07Z HAD LIFTED NORTH OF THE I-80 CORRIDOR WITH
S/SE WINDS SOUTH OF THE BOUNDARY ADVECTING LOW 60S DEWPOINTS INTO
THE CWA. IMPRESSIVE FORWARD PROPAGATING MCS MOVING INTO NE MO
HAD A LARGE AREA OF COLD CLOUD TOPS AT -60C OR LESS PAST FEW
HOURS. THIS MCS WAS BEING MAINTAINED BY A 55-65 KT SW 850MB JET WHICH
TAPPED INTO A 15-17C DEWPOINT POOL OVER THE PLAINS. FIRST FORECAST
ISSUE WILL BE THE IMPACT OF THIS MCS ON THE CWA THIS MORNING.
AWIPS DISTANCE/SPEED TOOL TAKES THE LEADING EDGE INTO THE FAR
WESTERN CWA JUST BEFORE 10Z/5AM. LATEST HRRR AND 4KM NSSL WRF
SEEMED TO HAVE THE BEST HANDLE ON THIS SYSTEM AND BOTH SHOW
CONVECTION MAINTAINING INTENSITY AT LEAST THROUGH THE WESTERN HALF
OF THE CWA THROUGH 12-13Z. STRONG 850MB MOISTURE TRANSPORT FEED IN
FROM THE SW TO KEEP HEAVY RAIN RATES OF 1.5 IN/HR WHICH COULD LEAD TO
ANOTHER ROUND OF FLASH FLOODING...ESPECIALLY IF FORWARD SPEED
SLOWS OR TRAINING DEVELOPS. WILL NEED TO EXTEND THE CURRENT FLASH
FLOOD WATCH THROUGH 00Z. SEVERE WIND GUSTS WILL ALSO NEED TO BE
MONITORED FOR THE NEXT FEW HOURS...AS LATEST SPC MESOANALYSIS
SHOWS AN AREA OF 1K DCAPE SHIFTING INTO WEST CENTRAL IL. KIRK IN
NE MO RECENTLY REPORTED A GUST OF 57 KTS ON THE LEADING EDGE OF
THIS LINE.
SECONDARY FORECAST CONCERN IS POSSIBLE SVR CONVECTION THIS
AFTERNOON FORMING ALONG REMNANT MESOSCALE BOUNDARIES. FORECAST
SOUNDINGS SHOW LITTLE IN THE WAY OF CINH...AND WITH AFTERNOON
HEATING SFC BASED CAPES OF 2000-2500 J/KG AND 40KTS 0-6KM BULK
SHEAR WOULD SUPPORT SEVERE STORMS. OF COURSE QUESTION MARKS
REVOLVE AROUND STABILIZING EFFECTS OF MORNING MCS AND RECOVERY.
SPC HAS EXPANDED DAY 1 SLIGHT RISK TO INCLUDE AREAS NORTH OF I-70.
FOR TONIGHT...POTENTIAL IS THERE FOR ANOTHER MCS TO FORM NEAR THE
IA/MO BORDER REGION AND SHIFT EAST AFFECTING MAINLY THE NORTHERN
CWA INTO EARLY WEDNESDAY MORNING.
BY WEDNESDAY UPPER LEVEL RIDGING TEMPORARILY BUILDS OVER THE AREA
SHIFTING THE MAIN STORM PATH NORTH. LOW PRESSURE DEVELOPING OVER
THE PLAINS WILL TIGHTEN UP THE MSLP GRADIENT CAUSING SOUTH WINDS
TO GUST AROUND 30 MPH. THIS COMBINED WITH SOME SUN SHOULD PRODUCE
A VERY WARM DAY WITH HIGHS IN THE MID/UPPER 80S.
LONG TERM...THURSDAY THROUGH MONDAY
THURSDAY AND FRIDAY...CLOSED UPPER LOW SHIFTING INTO THE NORTHERN
PLAINS BRINGS A DIFLUENT SOUTHWEST MID LEVEL FLOW OVER THE
MIDWEST. LEAD SHORTWAVES RIPPLING THROUGH IN THIS FLOW WILL ACT
ON A HIGH P/W ATMOSPHERE FOR SEVERAL ROUND OF SHOWERS AND STORMS.
LOCALLY HEAVY RAIN AND SEVERE STORMS WILL BE POSSIBLE.
BY SATURDAY THE UPPER LOW BEGINS TO OPEN UP AND SHIFT
SOUTHEAST...HELPING EASE A COLD FRONT INTO THE AREA. MEDIUM RANGE
MODELS SHOW THIS TO BE A SLOW PROCESS...WITH MULTIPLE ROUNDS OF
THUNDERSTORMS LIKELY AS THE FRONT DRIFTS ACROSS THE CWA SATURDAY
AND SATURDAY NIGHT. AGAIN...SYNOPTIC SETUP FAVORS MORE LOCALLY
HEAVY RAIN AND STRONG TO SEVERE CONVECTION.
SUNDAY AND MONDAY...THE UPPER TROF SHIFTS ACROSS THE MIDWEST AND
GREAT LAKES...BRINGING A RETURN TO COOLER AND DRIER WEATHER.
25
&&
.AVIATION...
ISSUED 1115 PM CDT MON MAY 27 2013
COVERAGE OF SHOWERS AND THUNDERSTORMS AND THEIR AFFECT ON CIGS
AND VSBYS ACROSS OUR AREA THRU TUESDAY EVENING. ISOLATED SHOWERS
WERE DEVELOPING LATE THIS EVENING ACROSS THE NORTH AS A WARM
FRONT WAS DRAPPED OVER CENTRAL ILLINOIS. LARGEST AREA OF CONVECTION
WAS STILL LOCATED ALONG THE MISSOURI RIVER VALLEY AND THAT COMPLEX
WILL TAKE UNTIL MORNING BEFORE IT AFFECTS ANY OF OUR AREA. STILL
CONCERNED ABOUT THE CONTINUED DEVELOPMENT OF ISOLATED SHOWERS
ACRS OUR NORTHERN AREAS OVER THE PAST SEVERAL HOURS SO WILL INCLUDE
VCTS AT KBMI AND KPIA UNTIL WE CAN ACTUALLY SEE MORE WIDESPREAD
RAINS APPROACH. FURTHER SOUTH...WILL HAVE TO WAIT UNTIL THE COMPLEX
OUT OVER SOUTHWEST IOWA AND NW MISSOURI TRACKS INTO WEST CENTRAL IL
BETWEEN 10Z AND 13Z. HOWEVER...NOT THAT ENTIRELY CONFIDENT IT WILL
HOLD TOGETHER OTHER THAN SOME STRATIFORM RAINS AND POSSIBLY SOME
LOWER CIGS BUT THAT FAR OUT WILL NOT HIT THE CIGS THAT HARD.
WHATEVER OCCURRS TUESDAY MORNING...SHOULD TEMPORARILY END BEFORE
A RENEWED THREAT FOR SCATTERED TSRA BETWEEN 20Z AND 24Z. SFC WINDS
WILL BE OUT OF THE SOUTH AT 8 TO 13 KTS TNT...AND THEN SOUTH WINDS
WILL INCREASE TO 12 TO 17 KTS WITH GUSTS AS HIGH AS 25 KTS DURING
THE AFTERNOON.
SMITH
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS EVENING FOR ILZ027>031-036>038-
040>043-047>053-061.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
156 PM EDT TUE MAY 28 2013
.SYNOPSIS...
ISSUED AT 1043 AM EDT TUE MAY 28 2013
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS WILL MOVE THROUGH
THE AREA THIS AFTERNOON AS A WARM FRONT LIFTS NORTH THROUGH THE
REGION. A FEW OF THESE STORMS COULD BECOME STRONG TO SEVERE AS
WELL AS PRODUCE SOME LOCALLY HEAVY RAINFALL. RAIN CHANCES ARE
EXPECTED TO DECREASE DURING THE OVERNIGHT HOURS...MAKING FOR
PARTLY CLOUDY SKIES AND DRY CONDITIONS ON THURSDAY.
&&
.UPDATE...
ISSUED AT 1110 AM EDT TUE MAY 28 2013
CONDITIONAL SEVERE WEATHER THREAT REMAINS IN PLACE FOR LATER THIS
AFTERNOON. LATEST WATER VAPOR LOOP SHOWS A DECENT CONVECTIVELY
ENHANCED MIDLEVEL WAVE OVER IOWA THAT IS GRADUALLY MOVING EASTWARD.
SYNOPTIC SCALE UVM ASSOCIATED WITH THIS MCV WILL SPREAD OVER OUR
AREA LATER THIS AFTERNOON...ENCOUNTERING A RATHER MOIST AND
POTENTIALLY UNSTABLE AIRMASS LEFT IN THE WAKE OF THIS MORNINGS WARM
FRONTAL PASSAGE. DEGREE OF DIURNAL INSTABILITY RECOVERY REMAINS
QUESTIONABLE THOUGH. REMNANTS OF MORNING CONVECTION OVER ILLINOIS
ARE ALREADY IMPINGING ON OUR WESTERN BORDER WITH ABUNDANT CLOUD
COVER BLANKETING THE CWA. A FEW THIN SPOTS SEEN IN LATEST VIS
IMAGERY BUT OUR CWA REMAINS STABLE SO FAR. 12Z RAP CONTINUES TO
SUGGEST THIS WILL CHANGE THOUGH AS FILTERED INSOLATION COMBINES WITH
GOOD WAA TO PUSH TEMPS INTO THE LOW 80S. SURFACE DEWPOINTS WAY
OVERDONE BUT MODIFIED SOUNDINGS STILL SHOW MLCAPE VALUES APPROACHING
1500 J/KG OVER OUR EAST BY THE AFTERNOON. WITH 700MB WINDS
APPROACHING 50 KTS...THIS WARRANTS CONTINUED THREAT...MAINLY OVER
OUR NORTHEASTERN AREAS IN THE 18-00Z TIMEFRAME. MAIN HAZARD EXPECTED
TO BE STRAIGHT LINE WINDS BUT DECENT LOW LEVEL SHEAR VALUES SUGGEST
AN ISOLATED TORNADO CANT BE RULED OUT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 420 AM EDT TUE MAY 28 2013
WARM FRONT MOVG NORTH ACROSS THE CWA EARLY THIS MORNING IS EXPECTED
TO MOVE NORTH OF THE AREA BY THIS AFTN. A COUPLE OF THUNDERSTORM
CLUSTERS WERE MOVG EAST ALONG THE FRONT. FIRST SHOULD BE MOVG OUT
OF ERN PORTION OF CWA AROUND 12Z WHILE UPSTREAM MCS IN IA MAY
REACH THE AREA AROUND THE SAME TIME. LIKELY WILL BE SOME DIURNAL
WKNG OF THIS MCS HWVR SO SOME DOUBTS REMAIN IF IT WILL REACH OUR
AREA. SHRTWV RESPONSIBLE FOR THE STORMS UPSTREAM IS FCST TO MOVE
ACROSS THE CWA THIS AFTN THROUGH A MODERATELY UNSTABLE AIRMASS BY
THAT TIME. SOME WK CAPPING SOUTH OF THE WARM FRONT SHOULD BE
OVERCOME BY FORCING ASSOCIATED WITH THIS SYSTEM... ESPECIALLY
ACROSS NRN PORTION OF CWA. COMBINATION OF 30-40KT 0-6KM SHEAR AND
MODERATE INSTABILITY SUGGESTS SOME OF THE STORMS COULD BE SEVERE.
MODELS INDICATING ANOTHER CONVECTIVELY ENHANCED SHRTWV WILL MOVE
EAST ACROSS THE UPR GRTLKS TONIGHT. THIS COMBINED WITH SOME
LINGERING INSTABILITY AND CONVECTIVE OUTFLOW BOUNDARIES OVER THE
AREA MAY RESULT IN TSTMS AGAIN TONIGHT WITH BEST CHANCES ACROSS
THE NRN PORTION OF CWA CLOSER TO WARM FRONT AND SHRTWV FORCING.
DESPITE EXPECTED CONSIDERABLE CLOUDINESS TODAY... FAIRLY STRONG
GRADIENT MIXING SHOULD ALLOW HIGHS TO REACH THE L80S OVER MOST OF
THE CWA WITH CONTD S-SW FLOW TONIGHT RESULTING IN MINS ONLY IN THE
M-U60S.
&&
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 420 AM EDT TUE MAY 28 2013
ONGOING CONVECTION MAY BE LINGERING ALONG MODIFIED FRONTAL OR
OUTFLOW BOUNDARIES OVER PORTIONS OF THE FCST AREA AT THE START OF
THE PERIOD. FOR NOW...LEFT A LOW CHANCE FOR STORMS OVER NORTHERN
AREAS. THE UPSTREAM TROF WILL AMPLIFY WEDNESDAY...CAUSING LOW LEVEL
FLOW TO INCREASE AND THE BEST LOW LEVEL THETA E CONVERGENCE TO SHIFT
NORTH OF THE FCST AREA BY WEDNESDAY AFTERNOON. KEPT HIGHS IN THE MID
80S WEDNESDAY THROUGH FRIDAY SUPPORTED BY 850 MB TEMPS OF 15C TO
17C. THE ECMWF HAS TRENDED MORE AMPLIFIED WITH A TROF BECOMING
POSITIVELY TILTED BY SATURDAY. THERE WILL PROBABLY BE TWO ROUNDS OF
CONVECTION...THE FIRST AS A SHORT WAVE EJECTS NORTHEAST LATE
THURSDAY OR THURSDAY NIGHT. CONCERN FOR SEVERE STORM POTENTIAL GIVEN
JET ENERGY RACING SOUTHEAST TOWARD THE AREA. THE SECOND ROUND OF
CONVECTION SHOULD OCCUR AS THE UPPER LEVEL TROF LIFTS NORTHEAST
ACCOMPANIED BY A COLD FRONT EARLY THIS WEEKEND. HAVE BEEN TRENDING
FASTER WITH THE ARRIVAL OF STORMS LATE THIS WEEK GIVEN THE ARRIVAL
OF THE INITIAL SHORT WAVE. WPC DAY 4/5 SUPPORTS 1 TO 2.5 INCHES OF
RAIN LATE THIS WEEK GIVEN MOISTURE STREAMING INTO THE AREA AHEAD OF
THE UPPER TROF.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 155 PM EDT TUE MAY 28 2013
DIURNAL INSTABILITY RECOVERY WAS TOO SLOW TO CAPITALIZE ON OLD MCV
CURRENTLY MOVING THROUGH MICHIGAN AND JUST A FEW ISOLATED
SPRINKLES REMAIN OVER OUR CWA AT THE MOMENT. EXPECT THIS WILL
CONTINUE FOR THE NEXT FEW HOURS WITH SOME ENHANCED LOW LEVEL
MOISTURE BRINGING MVFR CEILINGS TO KSBN IN ITS WAKE. CONVECTION
CHANCES WILL THEREFORE DEPEND ON NEXT WAVE CURRENTLY PRODUCING
PRECIP OVER SOUTHERN ILLINOIS...NOT SLATED TO ARRIVE UNTIL LATER
THIS EVENING. EXPECT PERIODS OF SHOWERS AND THUNDERSTORMS
OVERNIGHT BUT CONFIDENCE IN EXACT PLACEMENT AND TIMING REMAINS
VERY LOW. CEILINGS SHOULD REMAIN VFR THOUGH WITH ONLY BRIEF VIS
REDUCTIONS IN HEAVIER PRECIP.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
UPDATE...AGD
SYNOPSIS...KG
SHORT TERM...JT
LONG TERM...SKIPPER
AVIATION...AGD
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1110 AM EDT TUE MAY 28 2013
.SYNOPSIS...
ISSUED AT 1043 AM EDT TUE MAY 28 2013
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS WILL MOVE THROUGH
THE AREA THIS AFTERNOON AS A WARM FRONT LIFTS NORTH THROUGH THE
REGION. A FEW OF THESE STORMS COULD BECOME STRONG TO SEVERE AS
WELL AS PRODUCE SOME LOCALLY HEAVY RAINFALL. RAIN CHANCES ARE
EXPECTED TO DECREASE DURING THE OVERNIGHT HOURS...MAKING FOR
PARTLY CLOUDY SKIES AND DRY CONDITIONS ON THURSDAY.
&&
.UPDATE...
ISSUED AT 1110 AM EDT TUE MAY 28 2013
CONDITIONAL SEVERE WEATHER THREAT REMAINS IN PLACE FOR LATER THIS
AFTERNOON. LATEST WATER VAPOR LOOP SHOWS A DECENT CONVECTIVELY
ENHANCED MIDLEVEL WAVE OVER IOWA THAT IS GRADUALLY MOVING EASTWARD.
SYNOPTIC SCALE UVM ASSOCIATED WITH THIS MCV WILL SPREAD OVER OUR
AREA LATER THIS AFTERNOON...ENCOUNTERING A RATHER MOIST AND
POTENTIALLY UNSTABLE AIRMASS LEFT IN THE WAKE OF THIS MORNINGS WARM
FRONTAL PASSAGE. DEGREE OF DIURNAL INSTABILITY RECOVERY REMAINS
QUESTIONABLE THOUGH. REMNANTS OF MORNING CONVECTION OVER ILLINOIS
ARE ALREADY IMPINGING ON OUR WESTERN BORDER WITH ABUNDANT CLOUD
COVER BLANKETING THE CWA. A FEW THIN SPOTS SEEN IN LATEST VIS
IMAGERY BUT OUR CWA REMAINS STABLE SO FAR. 12Z RAP CONTINUES TO
SUGGEST THIS WILL CHANGE THOUGH AS FILTERED INSOLATION COMBINES WITH
GOOD WAA TO PUSH TEMPS INTO THE LOW 80S. SURFACE DEWPOINTS WAY
OVERDONE BUT MODIFIED SOUNDINGS STILL SHOW MLCAPE VALUES APPROACHING
1500 J/KG OVER OUR EAST BY THE AFTERNOON. WITH 700MB WINDS
APPROACHING 50 KTS...THIS WARRANTS CONTINUED THREAT...MAINLY OVER
OUR NORTHEASTERN AREAS IN THE 18-00Z TIMEFRAME. MAIN HAZARD EXPECTED
TO BE STRAIGHT LINE WINDS BUT DECENT LOW LEVEL SHEAR VALUES SUGGEST
AN ISOLATED TORNADO CANT BE RULED OUT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 420 AM EDT TUE MAY 28 2013
WARM FRONT MOVG NORTH ACROSS THE CWA EARLY THIS MORNING IS EXPECTED
TO MOVE NORTH OF THE AREA BY THIS AFTN. A COUPLE OF THUNDERSTORM
CLUSTERS WERE MOVG EAST ALONG THE FRONT. FIRST SHOULD BE MOVG OUT
OF ERN PORTION OF CWA AROUND 12Z WHILE UPSTREAM MCS IN IA MAY
REACH THE AREA AROUND THE SAME TIME. LIKELY WILL BE SOME DIURNAL
WKNG OF THIS MCS HWVR SO SOME DOUBTS REMAIN IF IT WILL REACH OUR
AREA. SHRTWV RESPONSIBLE FOR THE STORMS UPSTREAM IS FCST TO MOVE
ACROSS THE CWA THIS AFTN THROUGH A MODERATELY UNSTABLE AIRMASS BY
THAT TIME. SOME WK CAPPING SOUTH OF THE WARM FRONT SHOULD BE
OVERCOME BY FORCING ASSOCIATED WITH THIS SYSTEM... ESPECIALLY
ACROSS NRN PORTION OF CWA. COMBINATION OF 30-40KT 0-6KM SHEAR AND
MODERATE INSTABILITY SUGGESTS SOME OF THE STORMS COULD BE SEVERE.
MODELS INDICATING ANOTHER CONVECTIVELY ENHANCED SHRTWV WILL MOVE
EAST ACROSS THE UPR GRTLKS TONIGHT. THIS COMBINED WITH SOME
LINGERING INSTABILITY AND CONVECTIVE OUTFLOW BOUNDARIES OVER THE
AREA MAY RESULT IN TSTMS AGAIN TONIGHT WITH BEST CHANCES ACROSS
THE NRN PORTION OF CWA CLOSER TO WARM FRONT AND SHRTWV FORCING.
DESPITE EXPECTED CONSIDERABLE CLOUDINESS TODAY... FAIRLY STRONG
GRADIENT MIXING SHOULD ALLOW HIGHS TO REACH THE L80S OVER MOST OF
THE CWA WITH CONTD S-SW FLOW TONIGHT RESULTING IN MINS ONLY IN THE
M-U60S.
&&
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 420 AM EDT TUE MAY 28 2013
ONGOING CONVECTION MAY BE LINGERING ALONG MODIFIED FRONTAL OR
OUTFLOW BOUNDARIES OVER PORTIONS OF THE FCST AREA AT THE START OF
THE PERIOD. FOR NOW...LEFT A LOW CHANCE FOR STORMS OVER NORTHERN
AREAS. THE UPSTREAM TROF WILL AMPLIFY WEDNESDAY...CAUSING LOW LEVEL
FLOW TO INCREASE AND THE BEST LOW LEVEL THETA E CONVERGENCE TO SHIFT
NORTH OF THE FCST AREA BY WEDNESDAY AFTERNOON. KEPT HIGHS IN THE MID
80S WEDNESDAY THROUGH FRIDAY SUPPORTED BY 850 MB TEMPS OF 15C TO
17C. THE ECMWF HAS TRENDED MORE AMPLIFIED WITH A TROF BECOMING
POSITIVELY TILTED BY SATURDAY. THERE WILL PROBABLY BE TWO ROUNDS OF
CONVECTION...THE FIRST AS A SHORT WAVE EJECTS NORTHEAST LATE
THURSDAY OR THURSDAY NIGHT. CONCERN FOR SEVERE STORM POTENTIAL GIVEN
JET ENERGY RACING SOUTHEAST TOWARD THE AREA. THE SECOND ROUND OF
CONVECTION SHOULD OCCUR AS THE UPPER LEVEL TROF LIFTS NORTHEAST
ACCOMPANIED BY A COLD FRONT EARLY THIS WEEKEND. HAVE BEEN TRENDING
FASTER WITH THE ARRIVAL OF STORMS LATE THIS WEEK GIVEN THE ARRIVAL
OF THE INITIAL SHORT WAVE. WPC DAY 4/5 SUPPORTS 1 TO 2.5 INCHES OF
RAIN LATE THIS WEEK GIVEN MOISTURE STREAMING INTO THE AREA AHEAD OF
THE UPPER TROF.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 640 AM EDT TUE MAY 28 2013
GENERALLY VFR CONDITIONS EXPECTED ACROSS NRN INDIANA THIS MORNING
AS MCS MOVG OUT OF NE INDIANA. UPSTREAM MCS OVER WRN IL WAS WKNG
AS STRONGER FORCING APPEARS TO BE SHIFTING NORTH INTO SRN WI AND
BETTER INSTABILITY TO THE SW OVER MO. JUST FCST TEMPO -SHRA AT SBN
WITH MINIMAL IMPACT ASSOCIATED WITH THIS FEATURE THIS MORNING. AMDAR
SOUNDING FROM FWA EARLY THIS MORNING SHOWING RATHER STRONG SWLY
FLOW ALOFT WHICH SHOULD MIX DOWN TO SFC RESULTING IN 15-25KT
WINDS BY LATE MORNING. SCT TS EXPECTED TO DVLP OVER NRN INDIANA
THIS AFTN AS AIRMASS DESTABILIZES AND WK SHRTWV CURRENTLY OVER IA
MOVES ENE ACROSS NRN INDIANA. CONTD WITH A TEMPO TS AT BOTH
TERMINALS AS THIS SYSTEM MOVES THROUGH IN THE AFTN. TS ALSO PSBL
IN THE AREA TONIGHT BUT KEPT OUT OF TAFS ATTM DUE TO CONSIDERABLE
UNCERTAINTY. EXPECT THERE WILL BE SUFFICIENT MIXING OVERNIGHT TO
PREVENT BR FROM FORMING DESPITE MOIST AIRMASS IN PLACE.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
UPDATE...AGD
SYNOPSIS...KG
SHORT TERM...JT
LONG TERM...SKIPPER
AVIATION...JT
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS PADUCAH KY
553 AM CDT TUE MAY 28 2013
.UPDATE...
ISSUED AT 553 AM CDT TUE MAY 28 2013
RENEWED CONVECTIVE ACTIVITY ACROSS SOUTH CENTRAL MISSOURI HAS
REQUIRED A REVISION IN THE NEAR TERM /TODAY/ FORECAST TO ACCOUNT
FOR THE PROPAGATION OF THE BROKEN CONVECTIVE LINE INTO THE WFO PAH
FORECAST AREA THIS MORNING. THE LATEST RUNS OF THE 3KM HRRR AND
12KM NAM-WRF SUGGEST SOME SCATTERED SHOWER AND THUNDERSTORM
ACTIVITY OVER PARTS OF SOUTHEAST MISSOURI AND SOUTHWEST ILLINOIS.
THE PREVIOUSLY MENTIONED POTENTIAL FOR ISOLATED CONVECTION OVER
THE PENNYRILE ALSO SEEMS MORE REASONABLE AS WELL.
CLOUD COVER...WINDS...TEMPERATURES AND DEWPOINTS HAVE ALSO BEEN
MODIFIED TO ACCOUNT FOR THE STORM SCALE ACTIVITY THIS MORNING AND
INTO THIS AFTERNOON. THE CLOUD COVER ALONE WILL LIKELY SHAVE MAX
TEMPERATURES DOWN 1-2 DEGREES FROM PREVIOUSLY FORECAST HIGHS WITH
THE ORIGINAL PACKAGE.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 304 AM CDT TUE MAY 28 2013
THE MESOSCALE CONVECTIVE SYSTEM OVER NORTHWEST/NORTH CENTRAL MO
OVERNIGHT SHOULD EVENTUALLY DIMINISH BEFORE IT REACHES THE
SOUTHERN IL/SOUTHEAST MISSOURI BORDER COUNTIES LATER THIS MORNING.
THIS IS CONSISTENT WITH EARLIER RUNS OF THE HIGH RESOLUTION MODELS
SUCH AS THE 3KM HRRR AND THE 13KM RAP GUIDANCE. PREVIOUSLY
INTRODUCED /WITH THE MONDAY MORNING FORECAST PACKAGE/ SOME CHANCE
POPS/WEATHER IN THE EXTREME SOUTHEAST PENNYRILE THIS AFTERNOON...BUT
THE SIGNAL HAS NOT BEEN CONSISTENT ENOUGH TO WARRANT A MENTION
WITH THIS PACKAGE. DAYSHIFT WILL STILL NEED TO WATCH FOR THIS
CONVECTIVE POTENTIAL.
FOR THE MOST PART DRY CONDITIONS SHOULD PREVAIL WITH CAPPING ALOFT
THROUGH MOST OF THE DAYTIME HOURS ON WEDNESDAY.
THE MID-ATLANTIC/SOUTHEAST U.S. RIDGE BRIEFLY HOLDS IN PLACE
WHILE THE SURFACE AND UPPER LEVEL FLOW BECOME MORE SOUTH/SOUTHWEST
IN ORIENTATION STARTING LATE TONIGHT INTO WEDNESDAY WITH AN
APPROACHING LOW. THE PRESSURE/HEIGHT GRADIENT TIGHTENS UP FROM THE
WEST AS AN NORTHWESTWARD TILTED SURFACE-UPPER LEVEL LOW MOVES OUT
OF THE NORTHERN ROCKIES AND INTO THE NORTHERN PLAINS /MAINLY IN
THE THE DAKOTAS/ BY WEDNESDAY NIGHT AND EARLY THURSDAY.
WITH THIS IN MIND...SURFACE WINDS...ESPECIALLY WEST OF INTERSTATE
57 IN ILLINOIS...INTERSTATE 55 IN SOUTHEAST MISSOURI AND ALONG
INTERSTATE 64 IN SOUTHERN ILLINOIS AND SOUTHWEST INDIANA WILL
INCREASE TO NEAR 15 KNOTS AFTER 9 AM CDT TODAY...PERSISTING
THROUGH THE EARLY TUESDAY EVENING. GIVEN THE LOWERED THRESHOLD FOR
WINDS ON AREA LAKES AND THE SOUTHERLY ORIENTATION OF THE WINDS
ALONG THE LONG AXIS OF MOST OF THE WATERWAYS IN THE AREA...DECIDED
TO POST A LAKE WIND ADVISORY FOR TODAY AND THIS EVENING.
RETURNING TO RAIN CHANCES...A SERIES OF SHORTWAVES WILL ROTATE
AROUND THE BASE OF THE APPROACHING LOW OVER THE DAKOTAS STARTING
WEDNESDAY NIGHT AND INTO THURSDAY. GIVEN THIS FOCUSED LIFT AND
NARROW ZONE OF INSTABILITY...INTRODUCED OR KEPT POPS IN PLACE FOR
THE WESTERN TWO THIRDS OF THE WFO PAH FORECAST AREA /MAINLY
SOUTHEAST MO...SOUTHERN IL...PURCHASE AREA OF WEST KENTUCKY/ FOR
WEDNESDAY NIGHT AND THURSDAY. THE POPS ARE INTRODUCED IN A STAIR
STEP FASHION...STARTING OUT ACROSS SOUTHERN RIPLEY/BUTLER COUNTIES
IN SOUTHEAST MO...GRADUALLY WORKING NORTH AND EAST INTO SOUTHERN IL/PURCHASE
AREA OF WEST KENTUCKY BY THURSDAY. THE CANADIAN /GEM/ GUIDANCE
SEEMS THE MOST CONSISTENT WITH THE INTRODUCTION OF POPS/WEATHER
ACROSS THE AREA. HOWEVER...GIVEN THE AREAL UNCERTAINTY OF THESE
POPS WITH THE OTHER MEDIUM RANGE GUIDANCE...USED A BLENDED...BUT
MORE CONSERVATIVE APPROACH IN SPREADING THE POPS/WEATHER NORTHEAST
WITH TIME.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 304 AM CDT TUE MAY 28 2013
SOME POSSIBILITY OF PRECIPITATION THROUGH MOST OF THE EXTENDED
PERIOD.
AT THE BEGINNING OF THE PERIOD...SYNOPTICALLY SPEAKING...A BLOCKING
H5 RIDGE CENTERED OVER THE MID ATLANTIC COAST WILL BEGIN TO BREAK
DOWN PUTTING OUR AREA IN SOUTHWEST FLOW ALOFT AND IN THE WARM SECTOR
AT THE SURFACE THROUGH FRIDAY NIGHT AS A SYSTEM DEVELOPS OVER THE
CENTRAL PLAINS.
MODELS DO SHOW MID LEVEL THERMAL RIDGING ACROSS THE AREA DURING THIS
PERIOD BUT H7 TEMPS REMAIN AOB 10C. EVEN AT THAT THE BIG QUESTION IS
WILL THERE BE ENOUGH CAPPING TO SHUT DOWN CONVECTIVE DEVELOPMENT IN
THE WARM SECTOR THROUGH FRIDAY NIGHT. MODELS IN DECENT AGREEMENT
THAT SMALL POPS ARE WARRANTED SO KEPT THEM IN PLACE.
THE BEST CHANCES FOR PRECIPITATION CONTINUE TO BE SATURDAY AND
SATURDAY NIGHT AS THE AFOREMENTIONED SYSTEM ACTUALLY CROSSES OUR
CWA. AS THE PARENT UPPER LEVEL TROUGH AXIS SLOWLY MAKES ITS WAY
ACROSS THE AREA...PRECIPITATION CHANCES WILL DIMINISH FROM WEST TO
EAST SUNDAY INTO SUNDAY NIGHT. BY MONDAY ALL PRECIPITATION SHOULD BE
CLEAR OF THE CWA AS HIGH PRESSURE OVERSPREADS THE REGION.
TEMPERATURES SHOULD REMAIN AOA NORMAL THROUGH THE PERIOD.
&&
.AVIATION...
ISSUED AT 553 AM CDT TUE MAY 28 2013
WITH THE LATEST REVISION TO THE PUBLIC FORECAST...WILL LIKELY NEED
TO ADD SOME RAIN TO AT LEAST THE KCGI TAF THIS MORNING. ANTICIPATE
VFR CEILINGS AND VISIBILITIES WILL REMAIN THE RULE FOR ALL THE WFO
PAH TAF SITES AT THIS TIME. ANY RAIN ACTIVITY IN OR NEAR THE TAF
SITES SHOULD NOT BE A FACTOR AFTER 20Z-21Z TODAY. SUSTAINED SURFACE
WINDS WILL PICK UP IN THE 10-15 KNOT RANGE WITH HIGHER GUSTS FROM
THE 180-220 DEGREE DIRECTIONAL RANGE THIS MORNING AND INTO THIS
AFTERNOON.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...LAKE WIND ADVISORY FROM 9 AM THIS MORNING TO 8 PM CDT THIS
EVENING FOR ILZ075>078-080>094.
MO...LAKE WIND ADVISORY FROM 9 AM THIS MORNING TO 8 PM CDT THIS
EVENING FOR MOZ076-086-087-100-107>112-114.
IN...LAKE WIND ADVISORY FROM 9 AM THIS MORNING TO 8 PM CDT THIS
EVENING FOR INZ081-082-085>088.
KY...LAKE WIND ADVISORY FROM 9 AM THIS MORNING TO 8 PM CDT THIS
EVENING FOR KYZ001>022.
&&
$$
UPDATE...SMITH
SHORT TERM...SMITH
LONG TERM...JP
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS PADUCAH KY
305 AM CDT TUE MAY 28 2013
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 304 AM CDT TUE MAY 28 2013
THE MESOSCALE CONVECTIVE SYSTEM OVER NORTHWEST/NORTH CENTRAL MO
OVERNIGHT SHOULD EVENTUALLY DIMINISH BEFORE IT REACHES THE
SOUTHERN IL/SOUTHEAST MISSOURI BORDER COUNTIES LATER THIS MORNING.
THIS IS CONSISTENT WITH EARLIER RUNS OF THE HIGH RESOLUTION MODELS
SUCH AS THE 3KM HRRR AND THE 13KM RAP GUIDANCE. PREVIOUSLY
INTRODUCED /WITH THE MONDAY MORNING FORECAST PACKAGE/ SOME CHANCE
POPS/WEATHER IN THE EXTREME SOUTHEAST PENNYRILE THIS AFTERNOON...BUT
THE SIGNAL HAS NOT BEEN CONSISTENT ENOUGH TO WARRANT A MENTION
WITH THIS PACKAGE. DAYSHIFT WILL STILL NEED TO WATCH FOR THIS
CONVECTIVE POTENTIAL.
FOR THE MOST PART DRY CONDITIONS SHOULD PREVAIL WITH CAPPING ALOFT
THROUGH MOST OF THE DAYTIME HOURS ON WEDNESDAY.
THE MID-ATLANTIC/SOUTHEAST U.S. RIDGE BRIEFLY HOLDS IN PLACE
WHILE THE SURFACE AND UPPER LEVEL FLOW BECOME MORE SOUTH/SOUTHWEST
IN ORIENTATION STARTING LATE TONIGHT INTO WEDNESDAY WITH AN
APPROACHING LOW. THE PRESSURE/HEIGHT GRADIENT TIGHTENS UP FROM THE
WEST AS AN NORTHWESTWARD TILTED SURFACE-UPPER LEVEL LOW MOVES OUT
OF THE NORTHERN ROCKIES AND INTO THE NORTHERN PLAINS /MAINLY IN
THE THE DAKOTAS/ BY WEDNESDAY NIGHT AND EARLY THURSDAY.
WITH THIS IN MIND...SURFACE WINDS...ESPECIALLY WEST OF INTERSTATE
57 IN ILLINOIS...INTERSTATE 55 IN SOUTHEAST MISSOURI AND ALONG
INTERSTATE 64 IN SOUTHERN ILLINOIS AND SOUTHWEST INDIANA WILL
INCREASE TO NEAR 15 KNOTS AFTER 9 AM CDT TODAY...PERSISTING
THROUGH THE EARLY TUESDAY EVENING. GIVEN THE LOWERED THRESHOLD FOR
WINDS ON AREA LAKES AND THE SOUTHERLY ORIENTATION OF THE WINDS
ALONG THE LONG AXIS OF MOST OF THE WATERWAYS IN THE AREA...DECIDED
TO POST A LAKE WIND ADVISORY FOR TODAY AND THIS EVENING.
RETURNING TO RAIN CHANCES...A SERIES OF SHORTWAVES WILL ROTATE
AROUND THE BASE OF THE APPROACHING LOW OVER THE DAKOTAS STARTING
WEDNESDAY NIGHT AND INTO THURSDAY. GIVEN THIS FOCUSED LIFT AND
NARROW ZONE OF INSTABILITY...INTRODUCED OR KEPT POPS IN PLACE FOR
THE WESTERN TWO THIRDS OF THE WFO PAH FORECAST AREA /MAINLY
SOUTHEAST MO...SOUTHERN IL...PURCHASE AREA OF WEST KENTUCKY/ FOR
WEDNESDAY NIGHT AND THURSDAY. THE POPS ARE INTRODUCED IN A STAIR
STEP FASHION...STARTING OUT ACROSS SOUTHERN RIPLEY/BUTLER COUNTIES
IN SOUTHEAST MO...GRADUALLY WORKING NORTH AND EAST INTO SOUTHERN IL/PURCHASE
AREA OF WEST KENTUCKY BY THURSDAY. THE CANADIAN /GEM/ GUIDANCE
SEEMS THE MOST CONSISTENT WITH THE INTRODUCTION OF POPS/WEATHER
ACROSS THE AREA. HOWEVER...GIVEN THE AREAL UNCERTAINTY OF THESE
POPS WITH THE OTHER MEDIUM RANGE GUIDANCE...USED A BLENDED...BUT
MORE CONSERVATIVE APPROACH IN SPREADING THE POPS/WEATHER NORTHEAST
WITH TIME.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 304 AM CDT TUE MAY 28 2013
SOME POSSIBILITY OF PRECIPITATION THROUGH MOST OF THE EXTENDED
PERIOD.
AT THE BEGINNING OF THE PERIOD...SYNOPTICALLY SPEAKING...A BLOCKING
H5 RIDGE CENTERED OVER THE MID ATLANTIC COAST WILL BEGIN TO BREAK
DOWN PUTTING OUR AREA IN SOUTHWEST FLOW ALOFT AND IN THE WARM SECTOR
AT THE SURFACE THROUGH FRIDAY NIGHT AS A SYSTEM DEVELOPS OVER THE
CENTRAL PLAINS.
MODELS DO SHOW MID LEVEL THERMAL RIDGING ACROSS THE AREA DURING THIS
PERIOD BUT H7 TEMPS REMAIN AOB 10C. EVEN AT THAT THE BIG QUESTION IS
WILL THERE BE ENOUGH CAPPING TO SHUT DOWN CONVECTIVE DEVELOPMENT IN
THE WARM SECTOR THROUGH FRIDAY NIGHT. MODELS IN DECENT AGREEMENT
THAT SMALL POPS ARE WARRANTED SO KEPT THEM IN PLACE.
THE BEST CHANCES FOR PRECIPITATION CONTINUE TO BE SATURDAY AND
SATURDAY NIGHT AS THE AFOREMENTIONED SYSTEM ACTUALLY CROSSES OUR
CWA. AS THE PARENT UPPER LEVEL TROUGH AXIS SLOWLY MAKES ITS WAY
ACROSS THE AREA...PRECIPITATION CHANCES WILL DIMINISH FROM WEST TO
EAST SUNDAY INTO SUNDAY NIGHT. BY MONDAY ALL PRECIPITATION SHOULD BE
CLEAR OF THE CWA AS HIGH PRESSURE OVERSPREADS THE REGION.
TEMPERATURES SHOULD REMAIN AOA NORMAL THROUGH THE PERIOD.
&&
.AVIATION...
ISSUED AT 1130 PM CDT MON MAY 27 2013
SHOULD BE A QUIET 24 HOURS AS THE MAIN AXIS OF ACTIVITY STAYS TO
OUR NORTH AND WEST...WHERE THE BEST UPPER FLOW AND SFC WARM FRONT WILL
BE SITUATED. MEANWHILE...IN OUR AREA...BEING SOUTH OF THE
FRONT...WE SHOULD CONTINUE TO SEE SOME CLOUDINESS (ALL VFR) FROM
TIME TO TIME...WITH GUSTY SOUTH WINDS AT TIMES...MAINLY IN THE
AFTERNOON.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...LAKE WIND ADVISORY FROM 9 AM THIS MORNING TO 8 PM CDT THIS
EVENING FOR ILZ075>078-080>094.
MO...LAKE WIND ADVISORY FROM 9 AM THIS MORNING TO 8 PM CDT THIS
EVENING FOR MOZ076-086-087-100-107>112-114.
IN...LAKE WIND ADVISORY FROM 9 AM THIS MORNING TO 8 PM CDT THIS
EVENING FOR INZ081-082-085>088.
KY...LAKE WIND ADVISORY FROM 9 AM THIS MORNING TO 8 PM CDT THIS
EVENING FOR KYZ001>022.
&&
$$
SHORT TERM...SMITH
LONG TERM...JP
AVIATION...CW
AREA FORECAST DISCUSSION
NWS JACKSON KY
135 AM EDT TUE MAY 28 2013
.UPDATE...
ISSUED AT 134 AM EDT TUE MAY 28 2013
NO UPDATE TO THE FORECAST WAS REQUIRED.
UPDATE ISSUED AT 1050 PM EDT MON MAY 27 2013
FORECAST ON TRACK. UPDATED GRIDS TO REFLECT CURRENT CONDITIONS. HRRR
MODEL INDICATING AN AREA OF LIGHT SHOWERS ENTERING THE BLUEGRASS
COUNTIES WHICH IS CURRENTLY IN THE FORECAST. THE SHOWERS THEN
DISSIPATE BUT RE-EMERGE NEAR THE CENTER OF OUR CWFA WITH THE BETTER
TERRAIN AROUND 08Z BEFORE ONCE AGAIN DISSIPATING AN HOUR OR SO LATER.
DID NOT INCLUDE THIS FEATURE IN THE FORECAST AS THE PCPN LOOKS VERY
LIGHT...IF AT ALL...AND THE HRRR IS THE ONLY MODEL INDICATING THIS
PCPN.
UPDATE ISSUED AT 845 PM EDT MON MAY 27 2013
MESOSCALE COMPLEX BEGINNING TO SWEEP INTO WRN KY. TOPS HAVE WARMED
SIGNIFICANTLY OVER THE PAST COUPLE HOURS EVEN AS THE LEADING EDGE OF
THE PCPN HAS FORMED ON THE OUTFLOW FROM PREVIOUS STORMS IN CNTRL ILL.
WINDS HAVE DIMINISHED TO LIGHT...SO WILL BE ABLE TO REMOVE EVENING
WORDING AND FCST ONLY LIGHT WINDS TONIGHT. MOST MODELS AND TIME
HEIGHT SECTIONS INDICATE THAT THERE MAY BE ENUF OF THE PCPN HOLD
TOGETHER TO GIVE OUR BLUEGRASS COUNTIES A BRIEF LIGHT RAIN SHOWER.
EVEN WITH NO PCPN FOR THE REST OF ERN KY...THE COMPLEX WILL PUSH
ADDITIONAL CLOUD COVER AND WILL GO WITH MOSTLY CLOUDY OVERNIGHT.
UPDATE ISSUED AT 625 PM EDT MON MAY 27 2013
NO PCPN WITHIN THE STATE AND THE STORMS IN ILL ARE EITHER MOVING
NORTH OR THE SOUTH END IS DISSIPATING. NEW MODELS INDICATE THE PCPN
WILL MOVE ACROSS IND/OH TO OUR NORTH BUT NOT INTO ERN KY DUE TO A
SIGNIFICANT LOW LEVEL RIDGE EXTENDING INTO THE COMMONWEALTH FROM THE
SOUTHERN ATLANTIC COAST. SWRN WINDS ARE STILL BREEZY BUT SHOULD
DIMINISH WITH THE SETTING SUN. WILL FURTHER UPDATE WHEN WINDS
DECREASE.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 310 PM EDT MON MAY 27 2013
A WARM FRONT CONTINUES TO LIFT TO THE NORTH AND EAST OUT OF THE CWA
AND AS OF 3 PM WAS LOCATED FROM SOUTHEASTERN INDIANA EAST INTO
SOUTHERN OH AND THEN SOUTHEAST INTO THE WV COALFIELDS. AS OF MID
AFTERNOON...A RATHER ZONAL PATTERN WAS IN PLACE ACROSS MUCH OF THE
CONUS WITH A TROUGH WORKING INTO THE WEST COAST OF THE CONUS...AND A
SHORTWAVE TROUGH MOVING ACROSS THE UPPER MS VALLEY WHILE A DEEP
TROUGH CONTINUES TO WORK THROUGH THE CANADIAN MARITIMES.
THE SHORTWAVE TROUGH OVER THE UPPER MS VALLEY WILL MOVE INTO THE
NORTHERN GREAT LAKES TONIGHT AND INTO THE DAY ON TUE WITH RIDING
GRADUALLY BUILDING ACROSS THE SOUTHEASTERN STATES AND SOUTHERN
APPALACHIANS THROUGH THE END OF THE PERIOD.
GENERALLY FLAT CU HAS DEVELOPED SO FAR OVER THE JKL CWA BUT WITH
DEWPOINTS IN THE UPPER 50S NEAR THE VICINITY AND JUST BEHIND THE WARM
FRONT SOME ISOLATED SHRA AND OR TSRA CANNOT BE RULED OUT THROUGH THIS
EVENING. CU SHOULD DISSIPATE AS WE MOVE TOWARD SUNSET...BUT AT LEAST
SOME DEBRIS CLOUDS FROM CONVECTION NOW OVER THE MS VALLEY SHOULD
EVENTUALLY WORK ACROSS THE REGION TONIGHT. IT WOULD SEEM THAT DRIER
AIR OVER MUCH OF KY DOWN IN THE TN VALLEY SHOULD LEAD TO THE SOUTHERN
END OF THIS COMPLEX WEAKENING AS IT WORKS EAST THIS EVENING AND INTO
THE OVERNIGHT. THE LATEST HRRR HANDLING OF IT SEEMS MOST REASONABLE
AND THE 12Z NAM SEEMS TO BE OVERDOING CONVECTION ATTM IN THE LOWER OH
VALLEY EAST OF THE COMPLEX OVER MO AND IL. THE GFS ALSO HAS SOME LATE
NIGHT CONVECTION OVER THE CWA AS WELL. THE 12Z ECMWF KEEPS ALL THE
ACTION CLOSER TO THE WARM FRONT. OPTED TO GO WITH SOME SLIGHT CHANCES
MAINLY THIS EVENING ACROSS THE NORTH...NORTH OF THE MTN PARKWAY..BUT
CONFIDENCE IN THIS IS NOT HIGH.
MOISTURE SHOULD REMAIN LIMITED AND AT THIS POINT ANY TRIGGERS HARD TO
DISCERN FOR CONVECTION ON TUE. THERE MAY BE A WEAK SHORTWAVE OR TO
WORKING AROUND THE RIDGE...BUT WITH HEIGHTS PROGGED TO RISE ON TUE
INTO TUE NIGHT...WE HAVE OPTED TO GO WITH A DRY FORECAST FOR TUE.
TEMPERATURES SHOULD MODERATE FURTHER ON TUE...INTO THE MID TO UPPER
80S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 300 PM EDT MON MAY 27 2013
RIDGING WILL HOLD OVER THE EASTERN US THROUGH THE END OF THE WEEK.
THIS WILL KEEP OUR AREA WEST OF THE HIGH PRESSURE AREA IN AN AREA OF
RETURN FLOW. THIS WILL LEAD TO AN EXTENDED PERIOD OF MILD NIGHTS AND
WARM DAYS. INSTABILITY WILL GREATLY INCREASE FROM WEDNESDAY ONWARD
DURING THE DAYLIGHT HOURS...BUT WE WILL BE LACKING ANY TRIGGERS.
MODELS ARE STILL LIKELY OVER AGGRESSIVE WITH THE AMOUNT OF SURFACE
MOISTURE EACH DAY...SO LIKELY OVERDOING THE CAPE. HOWEVER...SOME
GOOD CU FIELDS SHOULD DEVELOP EACH AFTERNOON...AND IT MAY BE
POSSIBLE TO POP A VERY ISOLATED SHOWER OR STORM ALONG THE HIGHER
RIDES IN THE SOUTHEAST EACH AFTERNOON FROM WEDNESDAY THROUGH FRIDAY.
EACH DAY SHOULD FEATURE A SLIGHT BETTER CHANCE OF THIS HAPPENING AS
DEWPOINTS SHOULD CONTINUE TO INCH UP THROUGH THE REMAINDER OF THE
WEEK.
BY THIS WEEKEND...HIGH PRESSURE WILL RELINQUISH ITS HOLD ON THE AREA
AS A MID LEVEL SHORTWAVE APPROACHES FROM THE WEST. INCREASING FLOW
AHEAD OF THIS FEATURE ON SATURDAY...COULD YIELD A BETTER SHOT OF AN
ISOLATED SHOWER OR STORM BY SATURDAY AFTERNOON. THE CHANCES FOR
SHOWERS AND STORMS WILL INCREASE HEADING INTO SUNDAY AS THIS TROUGH
PUSHES EAST ACROSS THE AREA. PRESENTLY...MODELS IN FAIRLY GOOD
AGREEMENT ON TIMING...SO CONFIDENCE REMAINS HIGHER THAN NORMAL FOR
DAY 7. WITH THE FRONTAL PASSAGE...SLIGHTLY COOLER WEATHER SHOULD
RETURN TO THE AREA BY EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 133 AM EDT TUE MAY 28 2013
VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE END OF THE PERIOD
AT ALL THREE AIRPORTS. WINDS WILL REMAIN LIGHT OVERNIGHT UNDER PARTLY
CLOUDY SKIES. CIGS WILL AVERAGE BETWEEN 11 AND 12 OVERNIGHT.
SCATTERED CU ARE EXPECTED TO FORM OFF AND ON DURING THE DAYLIGHT
HOURS TODAY...WITH SCATTERED CLOUDS ALSO PRESENT AROUND 11K. WINDS AT
LOZ AND SME COULD GUST TO AROUND 15KTS DURING THE PEAK HEATING OF THE
DAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AR
SHORT TERM...JP
LONG TERM...KAS
AVIATION...AR
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
401 PM EDT TUE MAY 28 2013
.SYNOPSIS...
A WARM FRONT WILL CONTINUE PUSH NORTH OF THE REGION THIS EVENING...BRINGING
A CHANCE FOR SHOWERS AND THUNDERSTORMS TO PORTIONS OF THE AREA. HIGH
PRESSURE BECOMES ANCHORED OFF THE MID ATLANTIC COAST LATER TONIGHT
THROUGH THE NEXT SEVERAL DAYS. SUMMERLIKE CONDITIONS AND GENERALLY
DRY CONDITIONS WILL PREVAIL FROM WEDNESDAY INTO THE UPCOMING WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
LATEST RADAR AND SATELLITE DEPICT A FEW SHOWERS AND TSTMS TO THE
WEST OF THE CWA ALONG THE EAST SLOPE OF THE APPALACHIANS AND THE
PIEDMONT. IN GENERAL...THE HIGH RES MODELS HAVE BEEN OVERDONE THUS
FAR WITH RESPECT TO COVERAGE OF THIS PRECIP...AND WILL HAVE A
POP FORECAST THAT IS A LITTLE LOWER THAN WHAT THESE MODELS WOULD
SUGGEST. HOWEVER...CERTAINLY CAN`T RULE OUT AT LEAST ISOLATED
COVERAGE OVER SOUTHERN VA/NE NC AND SCATTERED COVERAGE FARTHER
NORTH THROUGH THE EVENING HRS GIVEN SOME WEAK SHORTWAVE ENERGY
PUSHING ACRS THE AREA. SHEAR IS FAIRLY WEAK/0-6KM BULK SHEAR LESS
THAN 25 KT THROUGHOUT AND MID LEVEL LAPSE RATES ARE GENLY <6 C/KM
SO ONLY AN ISOLATED STRONGER STORM IS EXPECTED...PRIMARILY ACRS
THE FAR NORTH. SKIES CLEAR OUT FROM SW TO NE AFTER MIDNIGHT. MILD
WITH LOWS MAINLY FROM THE LWR TO MID 60S.
&&
.SHORT TERM /6 AM WEDNESDAY 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 /20Z TUESDAY THROUGH SUNDAY/...
CHALLENGING FCST NEXT 2-6 HRS AS TO WHERE AND WHEN ANY CONVECTION
DVLPS. RUC SUGGESTS SOME ACTIVITY DVLPNG NEXT 2 HRS ALONG LINE OF
AC CLOUD DECK CRNTLY LCTD FROM OXB-RIC WHILE NAM/SREF WAIT UNTIL
AFTR 22Z FOR ACTIVITY TO DVLP ACROSS MTS THEN MOVE EAST. GIVEN THE
CRNT CNDTNS LEANED TOWARD THE LATE AFTRN/ERLY EVE FOR CONVECTION
TO DVLP THEN MOVE EAST. THIS TO BE MAINLY ACROSS NRN HALF OF FA
(RIC/SBY) BTWN 22-02Z WHILE SRN TAF SITES (ORF/PHF/ECG) STAY DRY.
THUS...WENT AHEAD AND ADDED CB TO THE RIC AND SBY TAFS TOWARD 00Z.
APPEARS THAT SBY HAS THE GREATEST CHC FOR PCPN. SW WNDS AVG 10-20
KTS THRU 22Z.
OTW...XPCT VFR CNDTNS WITH ONLY HIGH LVL CLDNS (AOA 12K FT) TONITE.
SOME LGT BR PSBL LATE TONITE...BUT THAT WUD BE WHERE ANY RAIN OCCURS
SO HELD OFF WITH ANY BR ATTM.
OUTLOOK...BERMUDA HIGH PRESSURE ESTABLISHES ITSELF OFF THE COAST
FOR THE REMAINDER OF THE WEEK. DRY WITH VFR CNDTNS XPCTD.
&&
.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...LKB
SHORT TERM...LKB
LONG TERM...SAM
AVIATION...MPR
MARINE...SAM
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
119 PM EDT TUE MAY 28 2013
.SYNOPSIS...
A WARM FRONT WILL CONTINUE TO LIFT NORTH OF THE REGION TODAY INTO
THIS EVENING...AS HIGH PRESSURE BECOMES ANCHORED OFF THE MID
ATLANTIC COAST. SUMMERLIKE CONDITIONS WILL PREVAIL FROM WEDNESDAY
INTO THE UPCOMING WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EARLIER SHRA ACTIVITY ACRS THE ERN SHORE HAS PUSHED OFF TO THE NE
AND ENTIRE CWA IS IN WARM SECTOR (ASIDE FORM LOCALLY COOLER
ONSHORE COASTAL ERN SHORE AREAS). WEAK SHORTWAVE ENERGY CAN BE
SEEN ACRS SE OHIO/WV...WITH MORE POTENT SHORTWAVE PUSHING INTO THE
WRN GREAT LAKES. AS SOME OF THIS ENERGY CROSSES THE MTNS LATER THIS
AFTN/EVENING ALONG WITH SEVERAL MORE HRS OF PARTLY/MOSTLY SUNNY
SKIES/SFC HEATING...EXPECT SCTD SHRA/TSRA TO DEVELOP...MAINLY OVER
NORTHERN AREAS WHERE INSTABILITY AND FORCING IS A LITTLE BETTER
CLOSER TO THE SFC BOUNDARY. SOME OF THE OUTFLOW ENERGY MAY THEN HELP DRIVE
SOME OF THE CONVECTION TO THE SOUTH SO WILL CARRY AT LEAST 20%
POPS ALL ZONES AFTER ABOUT 20Z...BUT HIGHEST POPS (40-50%) STILL
LOOK TO BE OVER THE FAR NORTH...PUSHING INTO THE ERN SHORE BY 00Z.
SHEAR IS FAIRLY WEAK/0-6KM BULK SHEAR LESS THAN 25 KT THROUGHOUT
AND MID LEVEL LAPSE RATES ARE GENLY <6 C/KM SO ONLY AN ISOLATED
STRONGER STORM IS EXPECTED...PRIMARILY ACRS THE FAR NORTH.
MADE ONLY MINOR CHANGES TO LATEST GRIDDED FORECAST/DATABASE. MAX
TEMPS TODAY WILL BE MAINLY LWR-MID 80S WELL INLAND...75-80 ALONG THE
IMMEDIATE COAST (AND LOCALLY COOLER ERN SHORE BEACHES).
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
WED-THU...BLDG RDG ALOFT/H5 HEIGHTS INCREASING TO 588-590 DM
COMBINED WITH NEAR STATIONARY SFC HI PRES IN THE WRN ATLC...WILL
RESULT IN SUMMER-LIKE CONDS WED-THU. 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 TEMPS RISING INTO THE UPR 80S/LWR 90S OVER MOST OF
THE REGION...BUT COVERAGE EXPECTED TO BE 14% OR LESS. THE SKY WILL
AVERAGE OUT PRTLY/MSTLY SNY. 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 MORNG HRS).
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
LITTLE CHANGE IN THE EXTENDED AS STRONG HIGH PRESSURE AND FAIR
WEATHER PREVAIL. A COLD FRONT IS FORECAST TO APPROACH THE REGION
DURING THE UPCOMING WEEKEND.
MEDIUM RANGE MODELS CONTINUE TO DEPICT MEAN RIDGE OVER THE EAST AND
TROUGH OVER THE CNTRL CONUS DURING THE BEGINNING OF THE EXTENDED
PERIOD. HOWEVER...MODELS CONTINUE TO STRUGGLE WITH THE EVOLUTION AND
PROGRESSION OF THE CNTRL CONUS TROUGH EWD THROUGH THE END OF THE
PERIOD. STRONG SPEED MAX EXPECTED TO ROUGH THE BASE OF THE UPPER
TROUGH FRI INTO SAT OVER THE UPPER MIDWEST...EJECTING THE LEADING
SHORTWAVE OVER THE GREAT LAKES AND INTO SE CANADA. MODELS THEN
STRUGGLE WITH ADDITIONAL ENERGY DIVING DOWN THE BACKSIDE OF THE
TROUGH. THIS SHORTWAVE ENERGY IS EXPECTED TO ROUND THE BASE OF THE
UPPER TROUGH IN THE VICINITY OF THE LOWER MO RIVER VALLEY SUNDAY
MORNING. ACCORDING TO THE 27/12Z GFS...SHORTWAVE THEN TRAVERSES THE
TN VALLEY MONDAY...PUSHING A COLD FRONT THROUGH THE MID ATLANTIC
MONDAY AFTERNOON. 27/00Z ECMWF DEPICTS MUCH WEAKER SHORTWAVE ENERGY
OVER THE MID ATLANTIC...BUT THE TIMING OF THE FRONT MONDAY AFTERNOON
IS SIMILAR TO THE GFS. ECMWF SUGGESTS A MUCH WEAKER FRONT WITH LESS
PRECIP. WILL CONTINUE TO MONITOR FUTURE MODEL RUNS AS DETAILS ARE
WORKED OUT AND THIS IS STILL SEVERAL DAYS OUT. WILL INTRODUCE CLIMO
POPS (SLIGHT CHANCE) MONDAY AFTERNOON. MEANWHILE...STRONG UPPER
RIDGE WILL REMAIN ANCHORED OVER THE EAST FRIDAY. RIDGE AXIS AND
UPPER HIGH WILL SLIDE OFFSHORE SAT...AS SWLY FLOW RETURNS. WEAKNESS
UNDER THE RIDGE MAY LIFT TOWARD THE COAST SUN-MON...BRINGING
ADDITIONAL MOISTURE/CLOUD COVER. EXPECT THIS FEATURE (IF FUTURE
MODEL RUNS STILL PRODUCE THIS FEATURE) TO REMAIN OFFSHORE DUE TO THE
APPROACHING COLD FRONT/UPPER TROUGH.
WARM/UNSTABLE AIRMASS AND STEEP LOW LEVEL LAPSE RATES WILL PROVIDE
FOR AFTERNOON CU EACH DAY. HOWEVER...NEAR SEASONABLE PRECIP WATERS
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 WILL FRONTAL PASSAGE. SFC WINDS WILL GENERALLY BE SW
AOB 10 KT.
&&
.AVIATION /18Z TUESDAY THROUGH SATURDAY/...
CHALLENGING FCST NEXT 2-6 HRS AS TO WHERE AND WHEN ANY CONVECTION
DVLPS. RUC SUGGESTS SOME ACTIVITY DVLPNG NEXT 2 HRS ALONG LINE OF
AC CLOUD DECK CRNTLY LCTD FROM OXB-RIC WHILE NAM/SREF WAIT UNTIL
AFTR 22Z FOR ACTIVITY TO DVLP ACROSS MTS THEN MOVE EAST. GIVEN THE
CRNT CNDTNS LEANED TOWARD THE LATE AFTRN/ERLY EVE FOR CONVECTION
TO DVLP THEN MOVE EAST. THIS TO BE MAINLY ACROSS NRN HALF OF FA
(RIC/SBY) BTWN 22-02Z WHILE SRN TAF SITES (ORF/PHF/ECG) STAY DRY.
THUS...WENT AHEAD AND ADDED CB TO THE RIC AND SBY TAFS TOWARD 00Z.
APPEARS THAT SBY HAS THE GREATEST CHC FOR PCPN. SW WNDS AVG 10-20
KTS THRU 22Z.
OTW...XPCT VFR CNDTNS WITH ONLY HIGH LVL CLDNS (AOA 12K FT) TONITE.
SOME LGT BR PSBL LATE TONITE...BUT THAT WUD BE WHERE ANY RAIN OCCURS
SO HELD OFF WITH ANY BR ATTM.
OUTLOOK...BERMUDA HIGH PRESSURE ESTABLISHES ITSELF OFF THE COAST
FOR THE REMAINDER OF THE WEEK. DRY WITH VFR CNDTNS XPCTD.
&&
.MARINE...
LATEST ANALYSIS SHOWS A SFC WARM FRONT ORIENTED FROM NW TO SE FROM
NRN INDIANA INTO SW VA. OBS/BUOY REORTS SHOWING GENLY LIGHT S/SW
FLOW ACROSS THE AREA THIS MORNING..WITH LIGHT WINDS EXPECTED TO
CONTINUE THROUGH THIS MORNING. FRONT WILL PUSH NORTH ACROSS THE
WATERS BY EARLY AFTN, WITH SSW WINDS INCREASING TO 10-15 KT THIS
AFTN/TNGT. DESPITE TIGHTENING PRESSURE GRADIENT, WAA AND A STRONG
LLVL INVERSION WILL PREVENT HIGHER VELOCITY WINDS FROM MIXING DOWN
TO THE WATER SFC. THEREAFTER, AN EXTENDED PERIOD OF SUB-SCA
CONDITIONS EXPECTED THROUGH THE UPCOMING WEEKEND, AS HIGH PRESSURE
REMAINS ANCHORED JUST OFF THE SE COAST. 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...TMG
NEAR TERM...LKB/TMG
SHORT TERM...LKB/TMG
LONG TERM...SAM
AVIATION...MPR
MARINE...MAM
AREA FORECAST DISCUSSION...UPDATED
NWS BALTIMORE MD/WASHINGTON DC
1040 AM EDT TUE MAY 28 2013
.SYNOPSIS...
A WARM FRONT MOVE NORTH OF THE AREA TODAY...WITH A SHORTWAVE
PASSING BY JUST NORTH OF THE AREA. MUCH WARMER AIR IS EXPECTED
BEHIND THE WARM FRONT FOR THE SECOND HALF OF THE WEEK AS A BERMUDA
HIGH SETS UP OFFSHORE.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THOUGH A BULK OF THE PRECIP THIS MRNG AND THROUGHOUT THE DAY WILL
STAY NORTH OF THE MASON-DIXON LINE. THE COMBINATION OF ANY GOOD
AMNT OF CLEARING...SLY WINDS INCREASING DEWPOINTS...TEMPS
GRADUALLY CLIMBING AND WEAK LOW LEVEL BOUNDARIES COULD KICK OFF
SOME ISOLATED SHOWERS AND TSTMS AS THE DAY PROGRESSES. EVIDENCE OF
THIS HAS BEEN OCCURRING ALONG AND E OF I-95 FROM DC TO BALT MID
MRNG...W/ A BATCH OF CELLS THAT DEVELOPED ALONG A WEAK BOUNDARY
AND PRODUCED LOCALLY HEAVY RAIN. AS THE DAY PROGRESSES AND
CONVECTIVE PARAMETERS INCREASE...THIS WILL BECOME MORE FAVORABLE
FOR STRONGER CELLS - THOUGH ONLY A HANDFUL OF STRONG/SEVERE STORMS
EXPECTED AT BEST.
LOCAL GUIDANCE LIKE THE HRRR AND WRF SOLUTIONS SHOW ANOTHER WAVE
OR TWO OF WEAK INDIVIDUAL CELLS ALONG AND E OF I-95 THRU LATE
MRNG...BUT THE REST OF THE AREA WILL LARGELY CLEAR OUT OVER THE
NEXT COUPLE OF HRS. THIS WILL BE GOOD FOR THE BUILDING UP OF
FAVORABLE CONVECTIVE PARAMETERS. HIGHS TODAY WILL APPROACH
80...AND ALONG W/ DEWPOINTS GRADUALLY INCREASING INTO THE
L60S...THIS WILL BE ENOUGH FOR THE DEVELOPMENT OF SCATTERED
SHOWERS/TSTMS DURING THE LATER PORTIONS OF THE AFTN/EVE. THE
LOCALIZED UPPER SHORTWAVE THAT WILL BE SLIDING OFF THE NJ COAST
LATER TODAY - AND WHAT IS ULTIMATELY RESPONSIBLE FOR THE ACTIVITY
TODAY - WILL SKIRT THE NRN PORTIONS OF THE CWA THIS AFTN AND
EVENTUALLY PULL ANY EARLIER CONVECTION OFF THE COAST LATER
TONIGHT.
&&
.SHORT TERM /10 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
WITH THE WARM FNT N OF THE AREA TNGT THERE COULD BE ISOLD EVE
CNVCTN...THEN M CLDY SKIES. A MILD NGT W/ LOWS IN THE 60S...M50S
IN THE HIGHLANDS...A70 IN THE CITIES.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
UPPER-LEVEL HIGH PRESSURE WILL BUILD OVER THE REGION WHILE BERMUDA
HIGH SETS UP OVER THE ATLANTIC. SUBSIDENCE FROM THE UPPER-LEVEL HIGH
ALONG WITH A SOUTHWEST FLOW AROUND THE BERMUDA HIGH WILL ALLOW FOR
HOT AND HUMID CONDITIONS. MAX TEMPS WEDNESDAY WILL REACH THE UPPER
80S AND LOWER 90S ACROSS MOST LOCATIONS.
WARM AND HUMID CONDITIONS WILL CONTINUE WEDNESDAY NIGHT. MIN TEMPS
WILL RANGE FROM THE 60S ACROSS MOST LOCATIONS TO THE LOWER AND
MIDDLE 70S IN DOWNTOWN WASHINGTON/BALTIMORE.
UPPER-LEVEL HIGH PRESSURE REMAIN OVER THE REGION THURSDAY THROUGH
SATURDAY WHILE BERMUDA HIGH REMAINS OVER THE ATLANTIC. HOT AND HUMID
CONDITIONS ARE EXPECTED DURING THIS TIME...WHICH WILL LEAD TO THIS
SEASONS FIRST HEAT WAVE. MAX TEMPS WILL REACH THE 90S ACROSS MANY
LOCATIONS EACH DAY UNDER PLENTY OF SUNSHINE. TERRAIN CIRCULATION
COULD LEAD TO AN ISOLATED T-STORM DURING THE AFTERNOON/EVENING
HOURS...BUT THE CAPPING INVERSION SHOULD REMAIN STRONG ENOUGH TO
KEEP MOST AREAS DRY. THEREFORE...T-STORMS ARE NOT IN THE FORECAST AT
THIS TIME.
THE RIDGE WILL WEAKEN SUNDAY AND MONDAY ALLOWING FOR A COLD FRONT TO
MOVE INTO THE AREA...BRINGING A BETTER CHANCE FOR SHOWERS AND
THUNDERSTORMS.
&&
.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
ALTHO M CLDY VFR CONDS TDA/TNGT. ISOLD TSTMS PSBL THIS AFT/EVE.
HIGH PRESSURE WILL REMAIN OVER THE TERMINALS WEDNESDAY THROUGH
SATURDAY...CAUSING SOUTHWESTERLY WINDS. WIND GUSTS AROUND 15 KNOTS
ARE EXPECTED DURING THE AFTERNOON AND EVENING HOURS EACH DAY. VFR
CONDITIONS WILL DOMINATE...BUT BRIEF PERIODS OF SUBVFR VSBYS ARE
POSSIBLE DURING THE EARLY MORNING HOURS EACH DAY. A COLD FRONT WILL
APPROACH THE TERMINALS SUNDAY AND MONDAY...BRINGING A BETTER CHANCE
FOR SHOWERS AND THUNDERSTORMS.
&&
.MARINE...
WINDS BLO SCA VALUES TDA/TNGT. ONLY THREAT WOULD BE AFTN/EVE
TSTMS..W/ THE BEST CHCS IN THE NRN CHES BAY.
BERMUDA HIGH WILL SET UP OVER THE ATLANTIC WEDNESDAY THROUGH
SATURDAY. SOUTHERLY WINDS ARE EXPECTED. WIND GUSTS WILL COME CLOSE
TO SCA CRITERIA...BUT FORECASTED GUSTS ARE CAPPED AROUND 15 KNOTS
DUE TO THE RELATIVELY COOLER WATERS.
A COLD FRONT WILL APPROACH THE WATERS SUNDAY AND MONDAY...BRINGING A
BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
UPDATE...GMS
PREV DISCUSSION...WOODY!/BJL
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1019 PM EDT WED MAY 29 2013
.SYNOPSIS...
ISSUED AT 432 PM EDT WED MAY 29 2013
UNSETTLED WEATHER WILL BE THE RULE THROUGH THE NEAR FUTURE...AS A
WARM FRONT GRADUALLY LIFTS NORTH INTO ONTARIO BY THURSDAY. THIS
FEATURE WILL PROVIDE CHANCES FOR SCATTERED SHOWERS AND THUNDERSTORMS
THROUGH MID DAY ON THURSDAY. WE`LL GET A BREAK FROM THE ACTIVITY FOR
THURSDAY AFTERNOON AND EVENING. BUT MORE CHANCES FOR SHOWERS AND
STORMS WILL ENTER THE PICTURE FRIDAY THROUGH SUNDAY...AS A COLD
FRONT SLOWLY SLIDES ACROSS THE GREAT LAKES.
&&
.UPDATE...
ISSUED AT 1019 PM EDT WED MAY 29 2013
CLEAR CONCERNS FOR THE OVERNIGHT ARE FOG AND PRECIP.
AIRMASS OVER MOST OF NORTHERN MI IS PRIMED FOR FOG. MARINE LAYER
HAS COME CHARGING IN FROM LAKE HURON...WITH THE OSC AWOS/SPOTTERS/
FOG IMAGERY SHOWING FOG IN THAT AREA...ALMOST UP TO APN. PLENTY OF
MARINE AIR STILL IN PLACE FROM THE STRAITS NORTH AS WELL.
MEANWHILE...RADIATIONAL COOLING BARELY UNDERWAY...BUT IS ALREADY
REDUCING VSBYS AT PLN AND BELLAIRE. WE HAD GROUND FOG DEVELOPING
IN A FIELD ADJOINING THE OFFICE RIGHT AT SUNSET. OF COURSE...
FAVORABLE RADIATIONAL COOLING CONDITIONS WILL BE COMING TO AN END
SOON...AS A THICK CIRRUS SHROUD IS ADVANCING ABOVE LAKE MI AND
CENTRAL UPPER MI. THIS SHOULD KEEP WIDESPREAD PEA SOUP FROM
FORMING...BUT HAVE STEADILY EXPANDED FOG MENTION AND SEVERITY IN
THE GRIDDED FORECASTS.
HAVE ALSO REJIGGERED PRECIP CHANCES. RADAR TRENDS IN WI REMAIN
SOMEWHAT OMINOUS AT 1ST GLANCE. BUT THE 00Z SOUNDING FROM GRB IS
RELATIVELY DRY (PWAT 0.9) AND CAPPED...AND THAT AIRMASS ISN/T
GETTING MORE UNSTABLE WITH TIME. 00Z APX SOUNDING WAS LESS
UNSTABLE AND MORE CAPPED. THOUGH A WARMER/MORE MOIST AIRMASS WILL
TRY TO WORK NORTHWARD INTO NORTHERN MI...THE LOW LEVEL JET WILL BE
MUCH STRONGER TO OUR WEST. UPSTREAM MCS APPEARS TO BE EVOLVING IN
RESPONSE...WITH LIGHTNING BECOMING LESS COMMON ALONG IT/S LEADING
(EASTERN) EDGE...AND MORE COMMON ALONG THE RIGHT REAR (SOUTHWEST)
FLANK. THUS...THE EARLIER FORECAST THINKING STILL APPEARS
SOUND....LIFTING THE MCS REMNANTS NE-WARD ACROSS WI AND UPPER MI
OVERNIGHT. LATEST HRRR RUNS REMAIN SUPPORTIVE OF THIS
THINKING...WITH NO PRECIP IN THIS CWA EXCEPT IN FAR WESTERN
CHIP/MACK. HAVE REMOVED CHANCE POPS FROM NE LOWER...ADDED SMALL
CHANCE POPS ALONG THE NW LOWER MI COAST...AND RETAINED CHANCE POPS
IN EASTERN UPPER (HIGHEST IN WESTERN CHIP/MACK).
MIN TEMPS WILL BE QUITE MILD OUTSIDE OF MARINE-INFLUENCED AREAS.
UPDATE ISSUED AT 739 PM EDT WED MAY 29 2013
APPEARS TO BE SAFE TO PULL PRECIP FROM THE SAGINAW BAY REGION THIS
EVENING. CU FIELD IS IN DECLINE...AND EARLIER ECHOES ON RADAR HAVE
EXITED.
HAVE REDUCED CLOUD COVER SUBSTANTIALLY THIS EVENING...PER SAT
TRENDS...ESPECIALLY IN NORTHERN LOWER MI.
HAVE EXPANDED FOG INTO PARTS OF NORTHERN LOWER...ESPECIALLY WHERE
LOW CLOUDS AND/OR MARINE AIR LINGERED LONGEST TODAY. TEMP/DEW
POINT SPREADS ARE ALREADY 10F OR LESS AT APN/PLN...AND WITH WINDS
LIGHTENING AND SKIES (TEMPORARILY) CLEARING...CERTAINLY LOOKS LIKE
SOME FOG COULD FORM QUITE QUICKLY...PERHAPS EVEN BY MIDNIGHT. IT
WILL BE AN INTERESTING RACE...AS A CIRRUS SHROUD FROM UPSTREAM
SHRA/TSRA IS STEADILY ADVANCING ACROSS WI...AND WILL BE
ENCROACHING ON THE AREA LATE EVENING AND ESPECIALLY OVERNIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 432 PM EDT WED MAY 29 2013
ON THE LATEST SURFACE WEATHER MAP...1022 MB HIGH PRESSURE WAS OVER
VIRGINIA WHILE 1003 MB LOW PRESSURE WAS OVER NORTHERN ONTARIO AND
992 MB LOW PRESSURE WAS OVER WESTERN KANSAS...WHILE A SURFACE WARM
FRONT WAS LOCATED JUST SOUTH OF THE FORECAST AREA. SATELLITE
IMAGERY SHOWED LOTS OF CLOUDS ACROSS NORTHERN MICHIGAN BUT APX
RADAR WAS VOID OF RETURNS. THE MAIN SHORT TERM FORECAST CONCERNS
ARE NUMEROUS AND INCLUDE THUNDERSTORM POTENTIAL ACROSS SOUTHEAST
ZONES INTO THE EVENING HOURS THEN THUNDERSTORM CHANCES OVERNIGHT
AND AGAIN THURSDAY ACROSS ALL OF THE COUNTY WARNING AREA.
THIS EVENING...CLOUDS HAVE BEEN A REAL CHALLENGE THIS AFTERNOON AS
USUAL. MARINE STRATUS CONTINUES TO PLAGUE MARINE AREAS...AS WELL AS
SPILLING INTO NORTHWEST LOWER WHILE SOUTHWEST ZONES HAVE SEEN AN
INCREASE IN DIURNALLY DRIVEN CU (AFTER THE LOW CLOUDS MIXED OUT
EARLIER). THE TREND HAS BEEN FOR CLOUDS TO GENERALLY DISSIPATE
ACROSS THE SOUTHWESTERN ZONES AND THIS SHOULD CONTINUE THROUGH THE
EVENING HOURS. COULD SEE A SHOWER OR THUNDERSTORM POP UP ACROSS
SOUTHEAST ZONES OVER THE NEXT FEW HOURS WHERE THERE WAS THE MOST
SUN/HEATING TODAY...IN COMBINATION WITH A BIT OF CONVERGENCE FROM A
LAKE BREEZE OFF OF LAKE HURON. THEREFORE...WILL CONTINUE WITH LOW
CHANCE POPS DOWN THERE. SEVERE POTENTIAL LOOKS LIMITED WITH WINDS
ALOFT ON THE LIGHT SIDE.
OVERNIGHT...CONVECTION ACROSS EASTERN MINNESOTA AND EASTERN IOWA
EXPECTED TO TRACK TOWARD THE THETA-E RIDGE MOVING INTO THE NORTHERN
HALF OF THE FORECAST AREA OVERNIGHT. STILL SOME DOUBT WHETHER THESE
STORMS WILL SURVIVE THIS FAR EAST...SO WILL CONTINUE TO COVER IT
WITH CHANCE WORDING. SEVERE POTENTIAL REMAINS LIMITED WITH 0-6KM
BULK SHEAR OF 30 KNOTS OR LESS. WARM AND MUGGY OVERNIGHT WITH
LOWS RANGING FROM THE MIDDLE 50S NORTH TO THE MIDDLE 60S SOUTH.
THURSDAY...WE ARE EXPECTED TO FINALLY BREAK OUT INTO THE WARM
SECTOR AS THE SURFACE WARM FRONT MOVES THROUGH THE REGION LEADING
TO HIGHS RANGING FROM THE UPPER 70S NORTH TO THE MIDDLE 80S
SOUTHEAST. IN ADDITION...THETA-E RIDGE BUILDS IN FROM THE WEST. LOOKING
AT MODEL SOUNDINGS...NOT MUCH CAPPING IN EVIDENCE SO COULD SEE A
FEW INSTABILITY DRIVEN THUNDERSTORMS DEVELOPING IN THE AFTERNOON
AND EARLY EVENING HOURS...SO HAVE ADDED IN LOW CHANCE POPS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 432 PM EDT WED MAY 29 2013
OVERVIEW: 4-WAVE HEMISPHERIC PATTERN IN PLACE TO START THIS FORECAST
CYCLE WITH LONG WAVE TROUGHS ANCHORED OVER THE EASTERN PACIFIC (NEAR
150W) AS WELL AS FAR EASTERN CANADA (NEAR 60W)...WITH LOW AMPLITUDE
RIDGING IN BETWEEN. ON THE SHORTER SCALE...FAST MID LEVEL FLOW IN
PLACE ACROSS THE EASTERN PACIFIC DIGGING INTO AN INVERTED SHORT WAVE
TROUGH IN THE WESTERN CONUS INTO THE PLAINS. ASSOCIATED SFC LOW
CENTERED NEAR THE COLORADO/KANSAS BORDER THIS MORNING WITH A
SOMEWHAT STATIONARY FRONT ARCHING UP INTO THE GREAT LAKES. SFC LOW
AND STATIONARY FRONT CONTINUE TO DRIVE EPISODES OF SHOWERS AND
STORMS FROM THE CENTRAL PLAINS THROUGH THE MIDWEST/LOWER GREAT
LAKES. SHORT WAVE TROUGH WILL CONTINUE TO BE THE MAIN WEATHER PLAYER
AS IT SLOWLY WORKS THROUGH THE PLAINS AND ULTIMATELY THE GREAT LAKES
OVER THE NEXT SEVERAL DAYS. CONVECTIVE TRENDS/TIMING WILL BE THE
TOUGH PART OF THE FORECAST AS THIS OCCURS. TEMPERATURES WILL
INITIALLY BE ON THE WARMER SIDE OF THINGS (RAIN AND CLOUDS
DEPENDENT) BUT TURN RATHER COOL AGAIN FOR THE WEEKEND AS THE TROUGH
AND ASSOCIATED POCKET OF COLD AIR WORK THROUGH. SHAPING UP TO BE
ANOTHER RIP-OFF SUMMER WEEKEND...SORRY.
THURSDAY NIGHT AND FRIDAY...CLOSED AND NEARLY STACKED LOW PRESSURE
SYSTEM EXPECTED TO BE MIGRATING SLOWLY ACROSS THE NRN PLAINS INTO
THE UPPER MIDWEST THROUGH THIS TIMEFRAME WITH THE FRONT STRETCHED
SOMEWHERE THROUGH THE NRN GREAT LAKES. MAIN FOCUS FOR CONVECTION
THURSDAY NIGHT WILL LIKELY BE ACROSS THE MID TO UPPER MISSISSIPPI
RIVER VALLEY WHERE WARM/MOIST SOUTHERLY INFLOW WILL INTERACT WITH
BETTER SYNOPTIC FORCING. BUT THERE WILL BE THE CHANCE THAT SOME OF
THAT ACTIVITY COULD EVENTUALLY SPREAD INTO THE GREAT LAKES THURSDAY
NIGHT/FRIDAY MORNING AS MID LEVEL SHORT WAVE IMPULSE SWINGS UP INTO
THE REGION. THAT SAID...TOUGH TO HAVE HIGH CONFIDENCE IN THE DETAILS
AT THIS JUNCTURE GIVEN ALL THE CONVECTION THAT WILL OCCUR BETWEEN
NOW AND THEN. SO FOR NOW WILL HAVE JUST CHANCY POPS OVERNIGHT
THURSDAY NIGHT OVER THE WESTERN HALF OF THE CWA...AND ACROSS THE CWA
ON FRIDAY. DETAILS WILL HAVE TO BE REFINED LATER.
FRIDAY NIGHT THROUGH SUNDAY...PATTERN REMAINS UNSETTLED RIGHT ON
THROUGH THE WEEKEND AS PESKY CLOSED LOW MAKES SLOW PROGRESS INTO THE
GREAT LAKES. SHOWERS AND STORMS APPEAR MOST LIKELY ACROSS THE GREAT
LAKES REGION FRIDAY NIGHT INTO SATURDAY AS THE ASSOCIATED SFC FRONT
AND UPPER JET CORE PRESS INTO THE GREAT LAKES REGION...AND WILL HAVE
HIGHEST POPS DURING THIS TIME. AFTER FROPA...SUNDAY SHAPING UP TO BE
COOL AND DAMP ONCE AGAIN AS LIGHTER PRECIP LINGERS AND TEMPS DIP
BACK BELOW NORMAL.
MONDAY THROUGH WEDNESDAY...MID LEVEL TROUGH AND CORE OF COLD AIR
SLOWLY RETREATS EASTWARD ON MONDAY FOLLOWED BY LOWER AMPLITUDE
RIDGING FOR TUESDAY INTO WEDNESDAY. LARGE EXPANSE OF CANADIAN HIGH
PRESSURE SETTLES IN FOR MONDAY AND TUESDAY WHICH WILL CLEAR THINGS
OUT AND MAY LEAD MORE FROST POTENTIAL BOTH MONDAY AND TUESDAY
MORNING. DAYTIME TEMPS REBOUND FOR TUESDAY AND WEDNESDAY BACK CLOSE
TO NORMAL. HOWEVER...YET ANOTHER TROUGH IS SLATED TO BE DIPPING INTO
THE UPPER MIDWEST/WESTERN GREAT LAKES AROUND MIDWEEK BRINGING
ADDITIONAL RAIN CHANCES TO THE REGION TO ROUND OUT THE EXTENDED
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 739 PM EDT WED MAY 29 2013
SOME BR/FG TONIGHT...ESPECIALLY APN/PLN. CHANCES FOR SHRA/TSRA
LATE TONIGHT PLN...THURSDAY AFTERNOON ALL SITES.
WEAK RIDGE OF HIGH PRESSURE NOW OVER LAKE HURON WILL MOVE OFF TO
THE EAST...ALLOWING WARM/MOIST SOUTHERLY FLOW TO RETURN TO THE
REGION THURSDAY. APN/PLN SAW LIMITED HEATING/SUNSHINE
TODAY...THOUGH LOWER CLOUDS ARE EXPECTED TO EXIT THE REGION THIS
EVENING. THAT SHOULD ALLOW SOME FOG TO FORM...AT LEAST BEFORE A
CIRRUS SHROUD FROM TSRA IN WI OVERSPREADS NORTHERN MI. THOSE TSRA
WILL WEAKEN AS THEY MOVE NE...AND LARGELY MISS THE TAF
SITES...THOUGH HAVE A CHANCE AT GRAZING PLN LATE TONIGHT.
A CU FIELD WILL DEVELOP THURSDAY IN A WARM/MUGGY AIRMASS. SOME
SHRA/TSRA WILL TRY TO GET GOING IN THE AFTERNOON...AND HAVE ADDED
VCSH TO ALL TAF SITES AFTER 19Z.
LIGHT WINDS TONIGHT. SOUTH WINDS THURSDAY...BREEZIEST AT MBL.
&&
.MARINE...
ISSUED AT 432 PM EDT WED MAY 29 2013
WINDS NOT EXPECTED TO BE MUCH OF AN ISSUE THROUGH TONIGHT...GENERAL
SOUTHWEST GRADIENT WIND WITH SOME LAKE BREEZE INFLUENCE ON WHITEFISH
BAY AND FAR NORTHERN LAKE HURON NEARSHORE ZONES. WINDS WILL BECOME
MORE SOUTHERLY TONIGHT. REDUCED VISIBILITIES IN AREAS OF FOG AND
HAZE WILL BE AN ISSUE THROUGH THURSDAY GIVEN RELATIVELY HUMID AIR
MASS IN PLACE INTERACTING WITH COLDER LAKE WATERS. SOUTHERLY WINDS
WILL INCREASE BY FRIDAY AFTERNOON...WITH SMALL CRAFT ADVISORIES
LIKELY NEEDED ACROSS A MAJORITY OF THE NEARSHORE ZONES.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JZ
SYNOPSIS...KB
SHORT TERM...AS
LONG TERM...BA
AVIATION...JZ
MARINE...AS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
721 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 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 721 PM EDT WED MAY 29 2013
VFR CONDITIONS WILL CONTINUE INTO THE EARLY EVENING AT ALL SITES
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. AT SAW...SIGNS ARE POINTING TO AN UPSLOPE
LOW CLOUD AND FOG EVENT FROM LOW LEVEL MOISTURE COMING IN FROM LAKE
MICHIGAN. ESC...MNM AND ISQ ALL HAVE LOWER VIS AND/OR LOW CIGS AND
THIS WILL BE ADVECTED NORTH ON SOUTH UPSLOPE WINDS TO DETERIORATE
CONDITIONS AT SAW FROM VFR TO LIFR BY LATE EVENING. MIXING AND
HEATING WILL BRING BACK VFR BY MID MORNING AT SAW.
&&
.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...07
MARINE...KEC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
355 PM EDT TUE MAY 28 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 352 PM EDT TUE MAY 28 2013
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG OVER THE
GREAT LKS DOWNSTREAM OF DEEPENING TROF OVER THE WRN CONUS. THERE ARE
A PAIR OF SHRTWVS IN THE NRN PLAINS/UPR MS RIVER VALLEY LIFTING NEWD
IN THE SW FLOW ALF BTWN THE LARGER SCALE FEATURES. THE FIRST OF
THESE IS MOVING THRU IOWA AND CAUSING A BAND OF SHRA/SOME TS N OF
SFC/H85 WARM FNT IN THE LOWER GREAT LKS. THE BULK OF THESE SHRA ARE
MOVING ENEWD THRU LWR MI AND ON TRACK TO MISS THE CWA...BUT SOME SCT
-SHRA EXTENDING AS FAR W AS MPX ARE SHIFTING NEWD THRU WI AND
CLOSING IN ON THE SCNTRL CWA. THE HEAVIER/MOST WDSPRD SHRA MISSING
THE CWA TO THE SE APPEAR BEST CORRELATED WITH THE SHARPEST H85-5
QVECTOR CNVGC...WHILE THE SHRA IN WI APPEAR TIED TO ISENTROPIC
ASCENT ON THE 300-305K SFCS /H85-7/. OTRW...SKIES ARE CLDY OVER THE
CWA N OF THE WARM FNT WITH AMPLE MSTR IN THE SFC-H7 LYR SHOWN ON THE
12Z MPX/GRB/APX RAOBS. THESE CLDS HAVE GREATLY RESTRICTED THE
DIURNAL RECOVERY OF TEMP. BEHIND THE OTHER SHRTWV OVER NDAKOTA...A
MUCH DRIER AIRMASS IS NOTED SHIFTING EWD THRU THE NRN PLAINS.
FCST CONCERNS IN THE SHORT TERM INVOLVE POPS ASSOCIATED WITH
SHRTWV/WARM FNT TO THE S AND THEN DRYING TRENDS LATER TNGT INTO WED
AS DRY AIRMASS IN THE NRN PLAINS MOVES INTO THE UPR LKS.
TNGT...SINCE DEEPER H85-5 QVECTOR CNVGC IS PROGGED TO DRIFT ENEWD
THRU LWR MI AND INTO SE ONTARIO...EXPECT HEAVIER SHRA TO REMAIN SE
OF UPR MI. HOWEVER...WITH SHRTWV IN IOWA APRCHG THE CWA THRU WI AND
BAND OF ISENTROPIC ASCENT ON THE 300-305K SFCS IMPACTING MAINLY THE
CENTRAL AND ERN ZNS THIS EVNG...EXPECT AT LEAST ISOLD -SHRA TO DRIFT
THRU THIS AREA...MAINLY NEAR THE GREEN BAY/LK MI. LATER TNGT AFT THE
SHRTWV DRIFTS TO THE NE OF UPR MI AND HGTS BEGIN TO RISE UNDER THE
DNVA/VIGOROUS DEEP LYR QVECTOR DVGC IN THE WAKE OF THIS
DISTURBANCE...EXPECT A DRYING TREND ALF AND FOR ANY PCPN TO END W-E.
BUT LO CLDS AND SOME FOG WL BE AROUND WITH LINGERING LLVL MSTR AND
ONLY WEAK HI PRES SHIFTING OVHD. WITH THE LINGERING LO CLDS...TEMPS
SHOULD FALL ONLY A COUPLE OF DEGREES.
WED...UNDER RISING HGTS/DEEP LYR QVECTOR DVGC UNDER SHRTWV RDGING
ALF...EXPECT MID LVL DRYING AS AIRMASS NOW MOVING THRU THE NRN
PLAINS SHIFTS INTO THE UPR LKS. ALTHOUGH LO CLDS/SOME FOG WL LINGER
THRU SUNRISE...DIURNAL HEATING/MIXING SHOULD TEND TO BREAK UP THIS
LO CLD. SHARP SUBSIDENCE INVRN SHOWN ON FCST SDNGS BTWN H75-8 AND
LLVL ACYC FLOW WL TEND TO SQUASH ANY CONVECTION THAT MIGHT TRY TO
FIRE WITH DAYTIME HEATING/MORE HUMID LLVL AIRMASS THAT WL SUPPORT
SFC DEWPTS WELL INTO THE 50S. IN FACT...NAM/ GFS FCST SDNGS SHOW
CONVECTIVE TEMP AOA 90. MIXING TO H8-85 ON THESE FCST SDNGS HINT MAX
TEMPS WL REACH ARND 80 AWAY FM LK MODERATION.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 352 PM EDT TUE MAY 28 2013
WARM AND ACTIVE WEATHER PATTERN EXPECTED TO CONTINUE THROUGH MUCH OF
THE WEEKEND. FOG WILL ALSO BE PROBLEMATIC OVER THE GREAT LAKES AS
WARMER AIR MOVES INTO THE AREA ENHANCING THE MARINE LAYER.
THIS...COUPLED WITH RAIN FALLING INTO THE MARINE LAYER...WILL
INCREASE THE MOISTURE TRAPPED IN THE MARINE LAYER AIDING IN FOG
FORMATION. THE FOG IS EXPECTED TO MIX OUT BY THE LAST HALF OF THE
WEEKEND AS COOLER AIR MOVES IN ALOFT AND DRY AIR SPILLS OUT OF
CANADA INTO THE UPPER GREAT LAKES REGION.
WEDNESDAY NIGHT THROUGH THURSDAY...A WARM FRONT...EXTENDING FROM
SOUTHERN MN EASTWARD INTO CENTRAL WI AND CENTRAL LOWER MI WEDNESDAY
AFTERNOON...WILL LIFT NORTHWARD INTO THE UPPER MICHIGAN BETWEEN 00Z
AND 06Z WEDNESDAY NIGHT AS SHOWN BY OVERLAYING 850MB THETA E ALONG
WITH 850MB WINDS. THIS HAPPENS AROUND THE SAME TIME THAT HEIGHT
FALLS...ASSOCIATED WITH THE SURFACE LOW AND UPPER LEVEL 500MB LOW
OVER THE WEST HALF OF THE UNITED STATES...BEGIN TO SHIFT EASTWARD
INTO THE WESTERN UPPER PENINSULA. MOISTURE TRANSPORT INTO THE
REGION...ALONG WITH CONVERGENCE ALONG THE NOSE OF THE 850MB LLJ
LIFTING NORTHWARD INTO SOUTHEASTERN MN AND WESTERN WI...WILL BE
FAVORABLE FOR SHOWER AND THUNDERSTORM DEVELOPMENT. CAPE VALUES
DURING THIS TIME ARE PROGGED TO BE BETWEEN 500 J/KG AND 1000 J/KG
WITH THE NAM BEING ON THE HIGHER END AND MANY OF THE OTHER MODELS
AROUND 500-600 J/KG. WHILE INSTABILITY VALUES ARE FAVORABLE FOR
THUNDERSTORM DEVELOPMENT...THE CHANCES OF SVR WEATHER AT THIS POINT
ARE LIMITED AS BULK SHEAR VALUES WOULD BE MARGINAL...RANGING FROM 20
TO 25 KTS. FOR A MORE ORGANIZED SVR WEATHER THREAT...BULK SHEAR
VALUES WOULD NEED TO BE CLOSER TO 40-45 KNOTS OR GREATER.
THURSDAY NIGHT THROUGH FRIDAY...THE UPPER LEVEL LOW WILL REMAIN
NEARLY STATIONARY OVER THE NORTHERN PLAINS THROUGH THIS TIME PERIOD.
THE MAIN ISSUE WILL BE A SHORTWAVE PROGGED TO ROTATE AROUND THIS
UPPER LEVEL LOW AS THE SURFACE LOW SHIFTS INTO NORTHERN MN. EXACT
TIMING AND STRENGTH OF THE SHORTWAVE DIFFER FROM MODEL TO MODEL WITH
THE GFS STILL TRYING TO BRING A MUCH MORE AGGRESSIVE SHORTWAVE INTO
THE AREA. CURRENT TRENDS ARE SHOWING THAT THE SHORTWAVE OVER THE
PLAINS STATES THURSDAY NIGHT WILL ROTATE NORTHEASTWARD...REACHING
THE U.P. BY LATE MORNING TO EARLY AFTERNOON FRIDAY. CONFIDENCE IN
INTENSITY AND TIMING OF THE SHORTWAVE IS FAIRLY LOW AS THESE THINGS
ARE HIGHLY DEPENDENT UPON CONVECTIVE DEVELOPMENT.
FRIDAY NIGHT THROUGH SATURDAY NIGHT...THE SURFACE LOW WILL SHIFT
FROM NORTHERN MN FRIDAY NIGHT INTO UPPER MI SATURDAY AND INTO LOWER
MI SATURDAY NIGHT. AT THE SAME TIME THE UPPER LEVEL 500MB TROUGH
WILL SHIFT FROM NORTHERN MN INTO UPPER MI. THE CHANCE FOR SHOWERS
AND THUNDERSTORMS WILL CONTINUE OVER UPPER MI INTO SATURDAY
AFTERNOON...BEFORE THE SURFACE LOW SHIFTS INTO NORTHERN LOWER MI.
ON THE BACK SIDE OF THE SURFACE LOW SATURDAY EVENING...THE CHANCES
FOR THUNDERSTORM ACTIVITY WILL DIMINISH GREATLY...HOWEVER...THE
CHANCE FOR SHOWERS WILL REMAIN IN THE FORECAST AS THE UPPER LEVEL
TROUGH MOVES OVERHEAD.
SUNDAY AND SUNDAY NIGHT...THE 500MB TROUGH OVER THE UPPER PENINSULA
WILL SHIFT SLOWLY EASTWARD THROUGH SUNDAY NIGHT ALLOWING THE CHANCE
OF SHOWERS TO SLOWLY DIMINISH THROUGH SUNDAY EVENING. THE 06Z AND
12Z GFS STILL REMAINS THE OUTLIER AS IT TRIES TO PULL DRY AIR FROM
CANADA INTO THE UPPER PENINSULA TOO QUICKLY...AROUND 18Z...WHILE THE
EC/GEM KEEP THE MOISTURE IN PLACE THROUGH 00Z-06Z. THE NEW 06Z RUN
OF THE GFS TRENDED CLOSER TO THE EC/GEM...THEREFORE WILL HANG ON TO
CLOUD COVER AND CHANCE OF SHOWERS INTO EARLY SUNDAY EVENING.
MONDAY THROUGH TUESDAY...A BROAD SURFACE HIGH PRESSURE SYSTEM AND
UPPER LEVEL 500MB RIDGE WILL BUILD FROM NEAR HUDSON BAY SOUTHWARD
INTO MUCH OF THE UPPER MISSISSIPPI VALLEY THROUGH MONDAY
NIGHT...ALLOWING FOR COOL AND DRY WEATHER TO BUILD INTO THE REGION.
AT THE SAME TIME AN UPPER LEVEL TROUGH IS PROGGED TO FORM OVER
WESTERN CANADA. THE GFS/EC AGAIN HAVE INTENSITY AND PLACEMENT ISSUES
FOR THIS LOW...WITH THE GFS STRONGER AND MORE PROGRESSIVE...PLACING
THE THROUGH OVER THE UPPER PENINSULA BY LATE TUESDAY MORNING. THE EC
KEEPS THE TROUGH TO THE WEST OF THE AREA...OVER THE NORTHERN
PLAINS...THROUGH TUESDAY EVENING. WITH LOWER THAN NORMAL
CONFIDENCE...WILL STICK WITH MODEL CONSENSUS FOR THIS TIME FRAME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 122 PM EDT TUE MAY 28 2013
WITH ABUNDANT SFC-H75 MSTR SHOWN ON THE 12Z MPX/GRB/APX RAOBS IN
ADVANCE OF SFC WARM FNT IN THE LOWER GRT LKS MOVING SLOWLY TO THE
N...EXPECT SLOWLY DETERIORATING CONDITIONS AT THE TAF SITES THRU
TNGT...ESPECIALLY IN THE PRESENCE OF DIURNAL COOLING. IFR CONDITIONS
ARE POSSIBLE AT ALL 3 SITES BEFORE DAYTIME HEATING/MIXING ON WED
RESULT IN SOME IMPROVEMENT AS WEAK SFC HI PRES MOVES INTO THE AREA.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 352 PM EDT TUE MAY 28 2013
WITH GENERALLY WEAK PRES GRADIENT AND STABLE CONDITIONS OVER LAKE
SUPERIOR...EXPECT WINDS TO BE UNDER 25KT THRU THE WEEK. ALTHOUGH
SOME FOG MAY DEVELOP LATE TONIGHT OVER THE LAKE WITH GRADUALLY
INCREASING LOW LEVEL MOISTURE...THICKER AND MORE WIDESPREAD FOG IS
NOT LIKELY UNTIL SOME APPRECIABLE RAINFALL OCCURS OVER THE
LAKE...PROBABLY NOT UNTIL WED NIGHT. AT LEAST PATCHY DENSE FOG IS
THEN LIKELY INTO SAT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KEC
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
127 PM CDT WED MAY 29 2013
.UPDATE...
18Z 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 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 130 PM CDT WED MAY 29 2013
SHOWERS AND THUNDERSTORMS WILL BECOME MORE NUMEROUS ACROSS THE TAF
AREA THIS AFTERNOON AND EVENING. ANY STORMS THAT DEVELOP WILL HAVE
THE POTENTIAL TO CAUSE SOME GUSTY WINDS...HAIL..AND IFR
CONDITIONS. SHOULD SEE A LULL IN ACTIVITY OVERNIGHT...WITH
REDEVELOPMENT EXPECTED THURSDAY. IN THE MEANTIME...BKN MVFR LEVEL
CLOUDS WILL SCATTER OUT BRIEFLY THIS AFTERNOON...BUT NOT TOTALLY SCOUR OUT
BEFORE THE CONVECTION OVERSPREADS THE AREA. WINDS WILL BE
PREVALENT OUT OF THE SOUTHEAST...WITH DIURNAL GUSTING TODAY AND
THURSDAY.
KMSP...
MVFR DECK WILL BE MORE OF A SCATTERED NATURE THIS AFTERNOON...BUT
COULD BECOME BROKEN BELOW 1700 FT WITH SHOWERS/THUNDERSTORMS THIS
AFTERNOON/EVE. THUNDERSTORMS ARE EXPECTED TO ARRIVE AROUND
21Z...THEN INTERMITTENTLY PERSIST UNTIL DARK. SHOULD SEE A LULL
OVERNIGHT...THEN ADDITIONAL ACTIVITY BY THURSDAY AFTERNOON.
/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...LS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
145 AM CDT TUE MAY 28 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 400 PM CDT MON MAY 27 2013
PERSISTENT AREA OF LIGHT SHOWERS AND DRIZZLE NOTED SOUTH OF A LINE
FROM KMSP TO KEAU AND EAST OF LINE FROM SHAKOPEE TO TRUMAN. THIS
REGION IS REMNANTS OF MCS WHICH FORMED OVER NORTHERN IOWA DURING
THE OVERNIGHT. AREA CORRELATES WELL WITH GFS40 THETA E ADVECTION.
CURRENT HRRR ALSO SEEMS TO HAVE A GOOD HANDLE OF AREAL COVERAGE
AND INTENSITY. REGION WAS STRUGGLING EARLIER THIS AFTERNOON AS IT
MARCHED NORTH INTO DRIER AIR COLUMN AND CONVERGENCE DEPICTED AT
250MB. EXPECT CONTINUED SLOW MIGRATION OF PRECIPITATION SHIELD
NORTH AS LATE DAY SURFACE HEATING CONTINUES TO MAINTAIN OR SLOWLY
ENHANCE CURRENT INTENSITY. LOOK FOR CESSATION OF MOST PRECIP. FROM
THIS FEATURE BY AROUND 28/06Z. FOR THE REMAINDER OF THE OVERNIGHT
EXPECT ANOTHER LATE NIGHT MCS TO FOLLOW THE PLACEMENT OF A WARM
FRONTAL BOUNDARY ABOVE CENTRAL TO NORTHERN IOWA. MCS WILL AGAIN
FORM OVER EASTERN SODAK AND FOLLOW 1000-500MB THICKNESS LINE
DROPPING ANOTHER THREE QUARTERS TO ONE INCH OF RAINFALL OVER
PORTIONS OF CENTRAL TO NORTHERN IOWA. SHOULD BE ANOTHER RATHER
GLANCING BLOW FOR THE FAR SW AND SOUTH CENTRAL PORTION OF THE MN
CWA...SIMILAR TO THE PREVIOUS THREE NIGHTS...WITH A FEW TENTHS TO
POSSIBLY FOUR TENTHS OF AN INCH EXPECTED OVER THIS REGION...WITH
HEAVIEST AMOUNTS OVER FAR SOUTH CENTRAL MINNESOTA.
MCS OVER NORTHERN IOWA SHOULD FOLLOW SAME TRAJECTORY AS TODAY`S
PCPN SHIELD...WITH POSSIBLY A FEW MORE EMBEDDED THUNDERSTORMS
AS LI`S GRADUALLY RECEDE INTO NEGATIVE TERRITORY. MOISTURE FROM
THIS SYSTEM WILL AGAIN BE ON THE WEAK SIDE...WITH MAINLY AROUND
ONE TENTH OF AN INCH ON AVERAGE ANTICIPATED PRIOR TO PASSAGE.
USED A BLEND BETWEEN NAM AND GFS40 FOR TUESDAY`S HIGH TEMPERATURES
...AND THEN THROTTLED BACK ONE CATEGORY. OF COURSE INTENSITY AND
FORWARD SPEED OF RAINFALL SHIELD MENTIONED ABOVE WILL DETERMINE
WHETHER TEMPERATURES NEED TO BE CUT EVEN FURTHER.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 400 PM CDT MON MAY 27 2013
TUESDAY EVENING INTO WEDNESDAY MORNING IS EXPECTED TO BE A DRY
TIME FRAME...AS THE SURFACE WARM FRONT REMAINS TO THE SOUTH OVER
SOUTHERN IOWA AND THE LOW LEVEL MOISTURE/WARM AIR ADVECTION IS
FOCUSED THERE AS WELL. HOWEVER...SHOWERS AND THUNDERSTORMS SHOULD
OVERSPREAD THE AREA DURING THE DAY ON WEDNESDAY...AS THE WESTERN
TROUGH SURGES EASTWARD...AND THE FRONT AND ADVECTION PROCESSES
SHIFT NORTHWARD IN CONJUNCTION WITH A SHORTWAVE IMPULSE. STRONGLY
DIFFLUENT FLOW ALOFT COMBINES WITH THE LOW LEVEL JET
INFLUENCES...AND COULD SET THE STAGE FOR A FEW SEVERE STORMS ON
WEDNESDAY AFTERNOON/EVE.
ON THURSDAY...THE UPPER TROUGH TAKES ON A NEGATIVE TILT...AS THE
WARM FRONT LIFTS ACROSS THE AREA. THIS WILL CONTINUE THE SEVERE
WEATHER THREAT AND ENHANCE THE FLOODING POTENTIAL AS WELL. PWATS
WILL REMAIN NEAR CLIMATOLOGICAL RECORD VALUES /1.5 TO 2.0
INCHES/...WHILE THE TROUGH STRUCTURE PROVIDES THE SHEAR SUFFICIENT
FOR STRONG POSSIBLY SEVERE STORMS. ON FRIDAY...THE COLD FRONTAL
BOUNDARY ASSOCIATED WITH THE SURFACE LOW PASSES ACROSS THE
AREA...AND CONTINUES THE THREAT FOR WIDESPREAD SHOWERS AND
THUNDERSTORMS.
ALTHOUGH THE THREAT FOR SEVERE STORMS WILL DIMINISH ON SATURDAY IN
THE WAKE OF THE SURFACE LOW...RAIN SHOWERS WILL CONTINUE TO BE
POSSIBLE OVER THE WEEKEND AS THE MID/UPPER TROUGH ROTATES OVER THE
UPPER MIDWEST.
HIGH TEMPERATURES WILL REMAIN NEAR TO SLIGHTLY ABOVE NORMAL FOR THE
END OF MAY...RANGING THROUGH THE MID TO UPPER 70S...AND THEN
DECLINE TO AROUND 5 TO 10 DEGREES BELOW NORMAL FOR THE FIRST FEW
DAYS IN JUNE /65 TO 70 DEGREES/.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1049 PM CDT MON MAY 27 2013
ALL SITES INITIALIZED AT MVFR WITH IFR CIGS NOT ALL THAT FAR
OFF. AREA OF -SHRA/-DZ OVER WRN WI CONTINUES TO SHRINK...
EVENTUALLY SHUTTING OFF BY ABOUT 08Z-09Z. AS WINDS DIMINISH A BIT
AND PRECIP ENDS...CIGS WILL LOWER INTO IFR RANGE FOR MUCH OF THE
NIGHT. A WINDOW FOR PRECIP TO RETURN LOOKS MOST EVIDENT BETWEEN
10Z-16Z TMRW IN MN...AND A FEW HRS LATER IN WI...AND HAVE PLAYED
THE TAFS AS SUCH. PRECIP ITSELF WILL BE MAINLY VFR WITH POSSIBLY
SOME HEAVIER SHOWERS PRODUCING MVFR VSBY. SHOWERS LOOK TO END ARND
18Z- 20Z...WITH IMPROVING CONDS AFTERWARDS. NOT EXPECTING ANY
CB/TS THRU TMRW. WINDS WILL BE MAINLY SE THRU THE NIGHT...THEN
SOME LGT/VRBL WINDS WILL DEVELOP MID-TO-LATE DAY TMRW BEFORE WINDS
SWING SW.
KMSP...INITIALIZED JUST ABOVE IFR CIGS BUT AM EXPECTING CIGS TO
DROP BELOW 1 KFT BEFORE TOO LONG AND THEN TO REMAIN THERE THROUGH
THE REST OF THE OVERNIGHT HRS. WINDS LOOK TO REMAIN UP JUST
ENOUGH TO PREVENT FOG FORMATION. A WINDOW OF PRECIP EXPECTED TO
DEVELOP BETWEEN 14Z-20Z FOR KMSP AND HAVE RUN WITH MVFR VSBY DURG
THIS TIME. THAT MAY BE A BIT PESSIMISTIC SO THIS CAN BE ADJUSTED
IF NECESSARY. CONDS IMPROVE BY LATE TMRW AFTN TO VFR FOR BOTH
CIG/VSBY AND WILL REMAIN AS SUCH THRU TMRW EVE. WINDS REMAIN
MAINLY SE THRU THE PERIOD...BUT GO LGT/VRBL TMRW AFTN BEFORE
SHIFTING TO S AND SE TMRW EVE.
/OUTLOOK FOR KMSP/
WED...MVFR OR LOWER CIGS LIKELY...MAINLY IN THE AFTN. SHRA/TSRA
LIKELY... MAINLY IN THE AFTN. WINDS S 10-15 KT.
THU...MVFR OR LOWER CIGS LIKELY. SHRA/TSRA LIKELY. WINDS S 15-20
KT.
FRI...MVFR OR LOWER CIGS LIKELY. SHRA/TSRA LIKELY. WINDS SW 10-15
KT.
&&
.HYDROLOGY...
ISSUED AT 144 AM CDT TUE MAY 28 2013
SO FAR THE MPX CWA HAS LUCKED OUT THE LAST SEVERAL DAYS...AS HEAVY
RAINS HAVE REMAINED CONFINED TO IOWA. THIS LOOKS REMAIN THE CASE
THROUGH TUESDAY NIGHT. HOWEVER...WEDNESDAY WILL SEE THE UPPER
RIDGE OVER THE EAST COAST STRENGTHEN AND BUILD INTO THE GREAT
LAKES WHILE A POTENT TROUGH OVER THE ROCKIES BEGINS WORKING OUT
INTO THE PLAINS. THIS WILL FINALLY HELP PUSH THE WARM FRONT NORTH
ON WEDNESDAY. PWATS FROM THE NAM/GFS ARE FORECAST TO BE UP AROUND
THE CLIMATOLOGICAL RECORD FOR MAY WEDNESDAY INTO THURSDAY...WITH A
STRONG AND MOISTURE LADEN LLJ FORECAST TO COME UP INTO MN ON
WEDNESDAY AND SLOWLY WORK INTO WI THROUGH THURSDAY. THIS WILL
RESULT IN THE TREAT FOR HEAVY RAINS WEDNESDAY THROUGH THURSDAY
NIGHT ACROSS THE MPX CWA. IN PARTICULAR...AREAS AROUND SE MN INTO
WRN WI WILL HAVE THE HIGHEST THREAT FOR FLOODING DUE BOTH TO
RECENT WETNESS AND THE FACT THAT THESE AREAS WILL BE SPENDING THE
LONGEST AMOUNT OF TIME WITHIN THE GULF MOISTURE FEED. STILL LOTS
OF UNCERTAINTY AS TO TIMING AND EXACT PLACEMENT OF SFC
FEATURES...BUT WE COULD SEE SEVERAL ROUNDS OF THUNDERSTORMS
WEDNESDAY THROUGH THURSDAY NIGHT THAT COULD RESULT IN TOTAL
RAINFALL AMOUNTS BETWEEN 2 AND 4 INCHES WITH LOCALLY HIGHER
AMOUNTS. GIVEN UNCERTAINTIES...AND RECENT BIAS IN DETERMINISTIC
MODELS TO FORECAST TOO MUCH QPF MAKING IT UP INTO THE MPX
CWA IN RECENT DAYS...HAVE CONTINUED TO HOLD OFF ON ISSUING ANY
SORT OF FLOOD WATCH.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...AJZ
LONG TERM...LS
AVIATION...JPC
HYDROLOGY...MPG
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
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.
&&
.AVIATION...
18Z TAFS FOR KOFK...KOMA AND KLNK.
VFR AT ALL THREE TAF SITES FOR THE TIME BEING. WILL TREND BACK
INTO MVFR PRIMARILY WITH VSBYS GOING DOWN TO INTO THE 4SM CATEGORY
AFTER 10Z. AT KLNK AND KOMA HAVE ALSO BROUGHT IN TEMPO FOR -TSRA
WITH IFR CIGS AND VSBY STARTING AT THAT SAME 10Z TIME PERIOD. HAVE
KEPT THUNDER OUT OF KOFK TAF FOR NOW THINKING THAT MOST ACTIVITY
WILL DEVELOP ALONG SOMEWHAT OF STALLED OUT SURFACE BOUNDARY
EXTENDING ACROSS BOTH THE KOMA AND KLNK TAF SITES. EXPECT
THUNDERSTORMS TO END OR MOVE EAST OF AREA AFTER 16Z WITH ANOTHER
SHORT REPRIEVE BEFORE REDEVELOPMENT AGAIN INTO LATER FORECAST
PERIODS. OVERALL A VERY ACTIVE PATTER WILL CONTINUE FOR THE NEXT
SEVERAL DAYS.
MEYER
&&
.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 ELKO NV
1054 AM PDT TUE MAY 28 2013
.SYNOPSIS...A LOW PRESSURE SYSTEM WILL BRING SCATTERED SHOWERS TO
MAINLY EASTERN NEVADA THIS AFTERNOON AND EARLY EVENING. ANOTHER
LOW PRESSURE SYSTEM WILL BRING SCATTERED SHOWERS TO MAINLY NORTHERN
NEVADA ON WEDNESDAY. DRY WEATHER THURSDAY THROUGH THE WEEKEND.
&&
.UPDATE...SHORT WAVE TROUGH MOVING INTO UTAH AT THIS TIME WITH
DECREASING SHOWERS ACROSS THE FORECAST AREA. UPDATED FORECASTS TO
DECREASE SHOWERS COVERAGE TO SCATTERED ACROSS EASTERN NEVADA AND
ISOLATED OVER THE WESTERN PORTION OF THE FORECAST AREA FOR THE
REST OF THE DAY. ONLY ISOLATED SHOWERS NEAR THE UTAH BORDER THIS
EVENING. 91
&&
.PREV DISCUSSION... /ISSUED AT 242 AM /
SYNOPSIS...A LARGE SCALE TROUGH IS FORECAST THE NEXT COUPLE OF DAYS
OVER THE GREAT BASIN. THIS FEATURE WILL HAVE EMBEDDED SHORTWAVES
ROTATING AROUND THE BASE OF THE TROUGH. THIS PATTERN WILL BE
CONDUCIVE TO WET SHOWERY WEATHER WITH ISOLATED THUNDERSTORMS FOR
NORTHERN AND CENTRAL NEVADA TODAY AND TOMORROW. AS THE FRONTAL
BOUNDARY MOVES THROUGH...PERIODS OF MODERATE TO LOCALLY HEAVY
PRECIPITATION WILL BE POSSIBLE. ALSO EXPECTING GUSTY WINDS TODAY
ALONG WITH BELOW NORMAL TEMPERATURES FOR LATE MAY. THE RIDGE WILL
BUILD BACK INTO THE WEST ON FRIDAY AND SATURDAY.
SHORT TERM...TODAY THROUGH WEDNESDAY. UNSETTLED WEATHER WILL BE ON
TAP THIS FORECAST PERIOD AS A PACIFIC CYCLONE PUMMELS INTO THE
SILVER STATE. THE GFS...ECMWF AND NAM CONTINUE TO HONE IN ON
DIFFLUENT ONSHORE FLOW...ENHANCED PWS...AND A POTENT SHORTWAVE
BISECTING THE REGION. THE INTEGRATED WATER VAPOR TRANSPORT VECTORS
FROM THE GFS SUGGEST THAT THE LIONS SHARE OF THE MOISTURE WITH THIS
SYSTEM REMAINS WEST OF THE SIERRA. HOWEVER...CONTINUE TO EXPECT QPF
TO SPILL OVER INTO THE LKN CWA...WITH THE HRRR AND THE NAM12 PINGING
INTO .25 OF AN INCH LIQUID QPF OR MORE WITH THIS EVENT. THE LOWEST
SNOW LEVELS WILL BE OVER THE SHELDON NATIONAL WILDLIFE
REFUGE...HOVERING BETWEEN 7100 AND 7300 FEET...AND CLOSER TO 8000
FEET FOR THE WESTERN ZONES. THE HRRR IMPLIES UPWARD VERTICAL
VELOCITIES THAT WOULD SUPPORT TSRA...WHICH IS SUPPORTED BY THE +200
J/KG AND NEGATIVE LIS ON THE NAM12. HOWEVER...KEEP TS ACTIVITY
ISOLATED IN THE GRIDS. IN ADDITION TO THE PRECIPITATION...EXPECTING
GUSTY WINDS TODAY. GIVEN THE PRESSURE GRADIENT FORCES AT 700M AND
500MB...EXPECTED THE STRONGEST WINDS TO MATERIALIZE OVER NORTHERN
NYE AND WHITE PINE COUNTIES. ISSUED A NPW FROM 21Z TO 03Z TODAY.
EXPECTING A BREAK IN PRECIPITATION BEFORE A SECOND REINFORCING
SHORTWAVE MOVES INTO NORTHERN NV RESULTING IN ADDITIONAL RAIN
SHOWERS ON WEDNESDAY. BELOW NORMAL TEMPERATURES EXPECTED THIS
FORECAST PERIOD.
LONG TERM...WEDNESDAY NIGHT THROUGH NEXT TUESDAY. ALL MODELS
DEPICT A SHORTWAVE MOVING THROUGH THE FLOW WEDNESDAY NIGHT AND
THURSDAY. THIS APPEARS TO BE A FAST MOVING SYSTEM AND IS EXPECTED
TO BE WINDING DOWN SOMETIME EARLY THURSDAY MORNING FROM WEST TO
EAST. THE FLOW REMAINS NORTHWESTERLY AS AN UPPER RIDGE TRIES TO
WORK EAST. HIGHS ON THURSDAY WILL GENERALLY BE AROUND NORMAL FOR
THIS TIME OF YEAR. BREEZY TO MAYBE WINDY CONDITIONS POSSIBLE
THURSDAY AFTERNOON BUT AS IT STANDS RIGHT NOW...SHOULD BE BELOW
ADVISORY THRESHOLDS. BY FRIDAY...RIDGING SHOULD CONTINUE TO BUILD
OVER THE GREAT BASIN WITH THE AXIS SITUATED JUST TO THE WEST...ACROSS
OREGON AND CALIFORNIA. HEIGHTS WILL CONTINUE TO RISE...SO SHOULD
SEE SOME WARMING AS WELL DURING THE DAY...WITH AFTERNOON HIGHS
ABOVE NORMAL. BY THE WEEKEND...MODELS DIVERGE ON THE POSITION AND
STRENGTH OF A MIDWESTERN CANADIAN SYSTEM. SHOULD KEEP DRY WITH
TEMPERATURES AT OR ABOVE NORMAL.
AVIATION...SCT/NMRS -SHRA ACROSS THE AREA THIS MORNING WITH MVFR
CONDITIONS POSSIBLE. BY 18Z LATER THIS MORNING...VCTS POSSIBLE AT
KWMC...KELY...AND KEKO...CONTINUING IN THE AFTERNOON WITH MVFR/IFR
CIGS/VSBY AT TIMES. SHRA WILL TAPER TO -SHRA FROM WEST TO EAST
LATER THIS AFTERNOON AND EVENING. WINDS AT THE THREE TAF LOCATIONS
W-NW10-20G30KT...SLIGHTLY STRONGER IN KELY. KTPH SHOULD REMAIN
VFR...BUT WILL HAVE NW15-25G40KT...WITH POSSIBLE BLDU IN THE
AFTERNOON.
FIRE WEATHER...WETTING RAINS ARE POSSIBLE TODAY ACROSS ALL ZONES.
AS THE FRONTAL BOUNDARY MOVES THROUGH...PERIODS OF MODERATE TO
LOCALLY HEAVY PRECIPITATION WILL BE POSSIBLE...WITH ISOLATED TSRA. A
SECOND SLUG OF PACIFIC ENERGY WILL FOLLOW IN ITS WAKE RESULTING IN
MORE RAIN SHOWERS ON WEDNESDAY. MOST OF THE QPF WILL BE IN THE
NORTHERN ZONES...WHERE THE MOISTURE AXIS IS LOCATED. EXPECTING BELOW
NORMAL TEMPERATURES WITH NEGATIVE HEIGHT ANOMALIES THROUGH
WEDNESDAY. THE RIDGE WILL BUILD INTO THE WEST ON FRIDAY AND
SATURDAY...USHERING IN WARMER AND DRIER CONDITIONS.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 2 PM THIS AFTERNOON TO 8 PM PDT THIS EVENING
FOR NORTHEASTERN NYE COUNTY...NORTHWESTERN NYE COUNTY...WHITE
PINE COUNTY.
&&
$$
97/92/97
AREA FORECAST DISCUSSION
NWS ELKO NV
242 AM PDT TUE MAY 28 2013
.SYNOPSIS...A LARGE SCALE TROUGH IS FORECAST THE NEXT COUPLE OF DAYS
OVER THE GREAT BASIN. THIS FEATURE WILL HAVE EMBEDDED SHORTWAVES
ROTATING AROUND THE BASE OF THE TROUGH. THIS PATTERN WILL BE
CONDUCIVE TO WET SHOWERY WEATHER WITH ISOLATED THUNDERSTORMS FOR
NORTHERN AND CENTRAL NEVADA TODAY AND TOMORROW. AS THE FRONTAL
BOUNDARY MOVES THROUGH...PERIODS OF MODERATE TO LOCALLY HEAVY
PRECIPITATION WILL BE POSSIBLE. ALSO EXPECTING GUSTY WINDS TODAY
ALONG WITH BELOW NORMAL TEMPERATURES FOR LATE MAY. THE RIDGE WILL
BUILD BACK INTO THE WEST ON FRIDAY AND SATURDAY.
&&
.SHORT TERM...TODAY THROUGH WEDNESDAY. UNSETTLED WEATHER WILL BE ON
TAP THIS FORECAST PERIOD AS A PACIFIC CYCLONE PUMMELS INTO THE
SILVER STATE. THE GFS...ECMWF AND NAM CONTINUE TO HONE IN ON
DIFFLUENT ONSHORE FLOW...ENHANCED PWS...AND A POTENT SHORTWAVE
BISECTING THE REGION. THE INTEGRATED WATER VAPOR TRANSPORT VECTORS
FROM THE GFS SUGGEST THAT THE LIONS SHARE OF THE MOISTURE WITH THIS
SYSTEM REMAINS WEST OF THE SIERRA. HOWEVER...CONTINUE TO EXPECT QPF
TO SPILL OVER INTO THE LKN CWA...WITH THE HRRR AND THE NAM12 PINGING
INTO .25 OF AN INCH LIQUID QPF OR MORE WITH THIS EVENT. THE LOWEST
SNOW LEVELS WILL BE OVER THE SHELDON NATIONAL WILDLIFE
REFUGE...HOVERING BETWEEN 7100 AND 7300 FEET...AND CLOSER TO 8000
FEET FOR THE WESTERN ZONES. THE HRRR IMPLIES UPWARD VERTICAL
VELOCITIES THAT WOULD SUPPORT TSRA...WHICH IS SUPPORTED BY THE +200
J/KG AND NEGATIVE LIS ON THE NAM12. HOWEVER...KEEP TS ACTIVITY
ISOLATED IN THE GRIDS. IN ADDITION TO THE PRECIPITATION...EXPECTING
GUSTY WINDS TODAY. GIVEN THE PRESSURE GRADIENT FORCES AT 700M AND
500MB...EXPECTED THE STRONGEST WINDS TO MATERIALIZE OVER NORTHERN
NYE AND WHITE PINE COUNTIES. ISSUED A NPW FROM 21Z TO 03Z TODAY.
EXPECTING A BREAK IN PRECIPITATION BEFORE A SECOND REINFORCING
SHORTWAVE MOVES INTO NORTHERN NV RESULTING IN ADDITIONAL RAIN
SHOWERS ON WEDNESDAY. BELOW NORMAL TEMPERATURES EXPECTED THIS
FORECAST PERIOD.
.LONG TERM...WEDNESDAY NIGHT THROUGH NEXT TUESDAY. ALL MODELS
DEPICT A SHORTWAVE MOVING THROUGH THE FLOW WEDNESDAY NIGHT AND
THURSDAY. THIS APPEARS TO BE A FAST MOVING SYSTEM AND IS EXPECTED
TO BE WINDING DOWN SOMETIME EARLY THURSDAY MORNING FROM WEST TO
EAST. THE FLOW REMAINS NORTHWESTERLY AS AN UPPER RIDGE TRIES TO
WORK EAST. HIGHS ON THURSDAY WILL GENERALLY BE AROUND NORMAL FOR
THIS TIME OF YEAR. BREEZY TO MAYBE WINDY CONDITIONS POSSIBLE
THURSDAY AFTERNOON BUT AS IT STANDS RIGHT NOW...SHOULD BE BELOW
ADVISORY THRESHOLDS. BY FRIDAY...RIDGING SHOULD CONTINUE TO BUILD
OVER THE GREAT BASIN WITH THE AXIS SITUATED JUST TO THE WEST...ACROSS
OREGON AND CALIFORNIA. HEIGHTS WILL CONTINUE TO RISE...SO SHOULD
SEE SOME WARMING AS WELL DURING THE DAY...WITH AFTERNOON HIGHS
ABOVE NORMAL. BY THE WEEKEND...MODELS DIVERGE ON THE POSITION AND
STRENGTH OF A MIDWESTERN CANADIAN SYSTEM. SHOULD KEEP DRY WITH
TEMPERATURES AT OR ABOVE NORMAL.
&&
.AVIATION...SCT/NMRS -SHRA ACROSS THE AREA THIS MORNING WITH MVFR
CONDITIONS POSSIBLE. BY 18Z LATER THIS MORNING...VCTS POSSIBLE AT
KWMC...KELY...AND KEKO...CONTINUING IN THE AFTERNOON WITH MVFR/IFR
CIGS/VSBY AT TIMES. SHRA WILL TAPER TO -SHRA FROM WEST TO EAST
LATER THIS AFTERNOON AND EVENING. WINDS AT THE THREE TAF LOCATIONS
W-NW10-20G30KT...SLIGHTLY STRONGER IN KELY. KTPH SHOULD REMAIN
VFR...BUT WILL HAVE NW15-25G40KT...WITH POSSIBLE BLDU IN THE
AFTERNOON.
&&
.FIRE WEATHER...WETTING RAINS ARE POSSIBLE TODAY ACROSS ALL ZONES.
AS THE FRONTAL BOUNDARY MOVES THROUGH...PERIODS OF MODERATE TO
LOCALLY HEAVY PRECIPITATION WILL BE POSSIBLE...WITH ISOLATED TSRA. A
SECOND SLUG OF PACIFIC ENERGY WILL FOLLOW IN ITS WAKE RESULTING IN
MORE RAIN SHOWERS ON WEDNESDAY. MOST OF THE QPF WILL BE IN THE
NORTHERN ZONES...WHERE THE MOISTURE AXIS IS LOCATED. EXPECTING BELOW
NORMAL TEMPERATURES WITH NEGATIVE HEIGHT ANOMALIES THROUGH
WEDNESDAY. THE RIDGE WILL BUILD INTO THE WEST ON FRIDAY AND
SATURDAY...USHERING IN WARMER AND DRIER CONDITIONS.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 2 PM THIS AFTERNOON TO 8 PM PDT THIS EVENING
FOR NORTHEASTERN NYE COUNTY...NORTHWESTERN NYE COUNTY...WHITE
PINE COUNTY.
&&
$$
97/92/92/97
AREA FORECAST DISCUSSION
NWS BUFFALO NY
947 PM EDT WED MAY 29 2013
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH OF THE REGION...ALLOWING A HOT AND
HUMID AIRMASS TO BUILD ACROSS THE REGION FOR THE REMAINDER OF THE
WEEK. WEATHER WILL BECOME MORE UNSETTLED AS A COLD FRONT
APPROACHES FROM THE UPPER LAKES SATURDAY...AND MOVES ACROSS THE REGION
ON SUNDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
AT 945 PM...RADAR SHOWED DRY WEATHER ACROSS WESTERN NEW YORK. THE
REMNANTS OF CONVECTION UPSTREAM CAN STILL BE SEEN ON IR SATELLITE
IMAGERY. SOME GUIDANCE HINTS AT THIS...INCLUDING THE 18Z NAM AND
SEVERAL HRRR RUNS. GIVEN UPSTREAM RADAR...DO NOT EXPECT WIDESPREAD
COVERAGE...BUT CANNOT RULE OUT A SHOWER OR POSSIBLY A THUNDERSTORM
AS THIS MOVES ACROSS DURING THE EARLY MORNING HOURS.
TEMPS TONIGHT WILL BE QUITE MILD WITH A GOOD MIXING BREEZE
HOLDING OVERNIGHT LOWS IN THE LOWER 60S ACROSS THE HIGHER TERRAIN
OF THE SOUTHERN TIER AND TUG HILL...AND THE MID 60S ELSEWHERE.
ANY CONVECTION SHOULD COME TO AN END LATE OVERNIGHT...AND A
STRENGTHENING UPPER RIDGE COMBINED WITH THE WESTWARD NUDGE OF THE
BERMUDA HIGH WILL BOOST TEMPS ON THURSDAY TO THE LOWER TO MID 80S
ACROSS THE NORTH COUNTRY AND THE MID TO UPPER 80S ELSEWHERE...EVEN
TO THE LOW 90S CLOSER TO THE FINGER LAKES AND GENESEE VALLEY.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
AS ADVERTISED FOR THE PAST SEVERAL DAYS...VERY WARM AND MODERATELY
HUMID CONDITIONS WILL CONTINUE DURING THIS PERIOD. A MID SUMMER
`BERMUDA HIGH` WILL KEEP A FLOW OF 16 TO 18C H85 AIR FLOWING
NORTHWARDS ACROSS OUR FORECAST AREA...AND THIS WILL SUPPORT
AFTERNOON TEMPERATURES OF 85 TO 90 WITH SULTRY OVERNIGHT LOWS IN THE
MID TO UPPER 60S. THESE READINGS WILL BE MORE TYPICAL OF MID JULY.
ONE USUALLY CANNOT HAVE SULTRY CONDITIONS WITHOUT HAVING AT LEAST
THE THREAT FOR CONVECTION...AND THAT WILL BE THE CASE AS WE ADVANCE
THROUGH THE END OF THE WEEK. WHILE THE VAST MAJORITY OF THE TIME
WILL BE RAIN-FREE...THERE WILL BE THE RISK FOR THUNDERSTORMS THAT
WILL BE FOCUSED MAINLY NEAR LAKE BREEZE BOUNDARIES. DIGGING INTO THE
DETAILS...
THE CREST OF A H5 RIDGE ARCHING BACK ACROSS EASTERN ONTARIO AND THE
LOWER GREAT LAKES FROM THE MID ATLANTIC COAST WILL PROVIDE US WITH A
WARM AND DRY THURSDAY NIGHT. ENERGY EJECTING OUT OF A CLOSED LOW
OVER THE NORTHERN PLAINS WILL START TO FLATTEN THIS RIDGE AXIS ON
FRIDAY THOUGH...AND THIS MAY BE JUST ENOUGH TO HELP WEAKEN A
SUBSIDENCE INVERSION THAT WAS A SIGNIFICANT INHIBITOR TO CONVECTION
FROM THE DAY BEFORE. SBCAPES OF 1500 J/KG ARE EXPECTED ACROSS THE
SRN TIER FRIDAY AFTERNOON...AND WITH A WEAKENED CAP AND A LAKE
BREEZE BOUNDARY FORECAST TO BE MOVING EAST...THERE WILL BE THE
CHANCE FOR SOME THUNDERSTORMS FOR SITES GENERALLY EAST OF A LINE
FROM BATAVIA TO JAMESTOWN. WHILE THE WIND FIELDS DO NOT SUPPORT A
SOLID THREAT FOR SEVERE WEATHER...ANY STORMS THAT DEVELOP NEAR THE
LAKE BREEZE BOUNDARY COULD BECOME ROBUST ENOUGH TO PRODUCE LOCALLY
GUSTY WINDS AND SMALL HAIL. OTHERWISE...THE BULK OF THE REGION WILL
BE RAIN FREE ON FRIDAY WITH AFTERNOON TEMPERATURES CLOSE TO 90 AWAY
FROM THE LAKES.
DIURNALLY INDUCED CONVECTION WILL DIE OFF FRIDAY EVENING...BUT
WILL KEEP SLGT CHC POPS IN PLACE OVERNIGHT TO COVER THE UNLIKELY
CHANCE FOR ACTIVITY THAT ACCOMPANIES ANY SHORTWAVES THAT LIFT ACROSS
THE FLATTENING H5 RIDGE. LIKE THE PREVIOUS NIGHT...IT WILL BE A WARM
AND MUGGY NIGHT ACROSS THE REGION WITH LOWS GENERALLY IN THE MID TO
UPPER 60S.
SATURDAY HAS THE POTENTIAL TO BE MORE UNSETTLED THAN FRIDAY. WE WILL
STILL HAVE A WARM UNSTABLE AIRMASS IN PLACE...BUT WE WILL ALSO FIND
OURSELVES WITHIN THE JET ENTRANCE REGION OF A 120KT H25 JET THAT
WILL BE STREAMING ACROSS ONTARIO AND THE UPPER GREAT LAKES. THE
ADDED SYNOPTIC LIFT TO AN INCREASINGLY BUOYANT AIRMASS COULD LEAD TO
MORE WIDESPREAD AFTERNOON CONVECTION. WHILE PORTIONS OF THE IAG
FRONTIER SHOULD ONCE AGAIN BE `SHADOWED` BY LAKE ERIE...WILL
INCREASE LOW CHC POPS FROM CONTINUITY BY ABOUT 10 POINTS OVER THE
REMAINDER OF THE FORECAST AREA. IT WILL ONCE AGAIN BE QUITE
WARM...BUT WE SHOULD HAVE A LITTLE MORE CLOUD COVER SO WILL MAX
TEMPS SHOULD BE A DEGREE OR TWO LOWER THAN THE PREVIOUS DAY.
A LONGWAVE TROUGH WILL EASE ACROSS THE UPPER GREAT LAKES SATURDAY
NIGHT WHILE A COMPLEX AREA OF LOW PRESSURE AND ASSOCIATED FRONTAL
SYSTEM WILL CROSS LOWER MICHIGAN AND SOUTHERN ONTARIO. THIS SHOULD
LEAD TO THE LIKELIHOOD OF SHOWERS AND THUNDERSTORMS OVERNIGHT...
ESPECIALLY OVER THE WESTERN COUNTIES.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
IT WILL CERTAINLY BE COOLER...AND TO MANY...MORE COMFORTABLE EARLY
NEXT WEEK. A SPLIT FLOW OVER NORTH AMERICA WILL INCLUDE A LONG WAVE
TROUGH OVER EASTERN CANADA...AND THIS ALLOW H85 TEMPS TO DROP OFF
INTO THE SINGLE DIGITS. BEFORE WE GET TO THAT POINT THOUGH...WE WILL
HAVE SOME VERY UNSETTLED CONDITIONS TO CONTEND WITH ON SUNDAY.
A WAVY FRONTAL SYSTEM WILL SINK ACROSS THE FORECAST AREA ON SUNDAY
AND THIS WILL PRODUCE FAIRLY WIDESPREAD SHOWERS AND THUNDERSTORMS.
GIVEN THE SLOW MOVEMENT OF THE FRONT AND PWAT VALUES IN EXCESS OF
1.5 INCHES...THERE WILL BE A HEIGHTENED RISK FOR SIGNIFICANT RAINS.
STUBBORN CLEARING IS EXPECTED IN THE WAKE OF THE FRONT SUNDAY
NIGHT...BUT AT LEAST IT WILL BE MORE TOLERABLE FOR SLEEPING WITH MIN
TEMPS FORECAST TO BE IN THE 50S.
THE BASE OF A DIGGING H5 TROUGH WILL SWING ACROSS TO THE NORTH OF LK
ONTARIO ON MONDAY...AND WHILE THE MAJORITY OF THE DAY WILL BE RAIN
FREE...WILL KEEP SLGT TO LOW CHC POPS FOR ANY NUISANCE SHOWER
ACTIVITY. THE HIGHEST CHANCE FOR SHRA`S WILL BE FOUND IN THE
AFTERNOON ACROSS THE NORTH COUNTRY. HIGH TEMPERATURES WILL ONLY BE
IN THE 60S.
EXPANSIVE CANADIAN HIGH PRESSURE SHOULD THEN PROVIDE OUR REGION WITH
BEAUTIFUL WEATHER TUESDAY AND WEDNESDAY...AS BOUNTIFUL SUNSHINE WILL
BE ACCOMPANIED BY HIGH TEMPERATURES IN THE LOWER 70S.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
EXPECT MAINLY VFR CONDITIONS THROUGH THIS EVENING. A WEAK
DISTURBANCE WILL PASS DURING THE EARLY MORNING HOURS...BRINGING A
MINIMAL CHANCE FOR SHOWERS AND POSSIBLY A THUNDERSTORM. LATE
OVERNIGHT THE IS A CHANCE OF MVFR VSBYS IN LIGHT FOG TIL JUST
AFTER DAYBREAK...THEN VFR THROUGH THE DAY ON THURSDAY.
OUTLOOK...
THURSDAY NIGHT THROUGH SATURDAY...MAINLY VFR.
SUNDAY...MVFR WITH RAIN SHOWERS.
MONDAY...VFR.
&&
.MARINE...
SOUTHWEST WINDS WILL SLACKEN A BIT OVERNIGHT WITH FEWER GUSTS AND
SPEEDS FALLING TO AROUND 10 KNOTS. UPPER LEVEL RIDGING AND SURFACE
HIGH PRESSURE WILL KEEP LIGHT WINDS ACROSS THE EASTERN LAKES FOR THE
NEXT FEW DAYS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...WCH
NEAR TERM...APFFEL/WCH
SHORT TERM...RSH
LONG TERM...RSH
AVIATION...APFFEL/WCH
MARINE...APFFEL/WCH
AREA FORECAST DISCUSSION
NWS BUFFALO NY
849 PM EDT WED MAY 29 2013
.SYNOPSIS...
A WARM FRONT WILL PUSH NORTHEASTWARD ACROSS NORTH CENTRAL NEW YORK
THIS EVENING WITH A SOME SHOWERS AND THUNDERSTORMS. A HOT AND
HUMID AIRMASS WILL BUILD INTO THE REGION FOR THE REST OF THE WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
SHOWERS AND THUNDERSTORMS HAVE EXITED THE REGION...WITH JUST A FEW
SHOWERS LINGERING ACROSS THE SOUTHERN TIER AND PERHAPS THE SAINT
LAWRENCE VALLEY AS WELL. EXPECT THIS DIMINISHING TREND TO CONTINUE
THIS EVENING...WITH THE VAST MAJORITY OF THE CWA TO REMAIN DRY
DURING THIS TIME. AFTER THIS...THE REMNANTS OF CONVECTION UPSTREAM
CAN STILL BE SEEN ON IR SATELLITE IMAGERY. SOME GUIDANCE HINTS AT
THIS...INCLUDING THE 18Z NAM AND SEVERAL HRRR RUNS. GIVEN
UPSTREAM RADAR...DO NOT EXPECT WIDESPREAD COVERAGE...BUT CANNOT
RULE OUT A SHOWER OR POSSIBLY A THUNDERSTORM AS THIS MOVES ACROSS
DURING THE EARLY MORNING HOURS.
TEMPS TONIGHT WILL BE QUITE MILD WITH A GOOD MIXING BREEZE
HOLDING OVERNIGHT LOWS IN THE LOWER 60S ACROSS THE HIGHER TERRAIN
OF THE SOUTHERN TIER AND TUG HILL...AND THE MID 60S ELSEWHERE.
ANY CONVECTION SHOULD COME TO AN END LATE OVERNIGHT...AND A
STRENGTHENING UPPER RIDGE COMBINED WITH THE WESTWARD NUDGE OF THE
BERMUDA HIGH WILL BOOST TEMPS ON THURSDAY TO THE LOWER TO MID 80S
ACROSS THE NORTH COUNTRY AND THE MID TO UPPER 80S ELSEWHERE...EVEN
TO THE LOW 90S CLOSER TO THE FINGER LAKES AND GENESEE VALLEY.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
AS ADVERTISED FOR THE PAST SEVERAL DAYS...VERY WARM AND MODERATELY
HUMID CONDITIONS WILL CONTINUE DURING THIS PERIOD. A MID SUMMER
`BERMUDA HIGH` WILL KEEP A FLOW OF 16 TO 18C H85 AIR FLOWING
NORTHWARDS ACROSS OUR FORECAST AREA...AND THIS WILL SUPPORT
AFTERNOON TEMPERATURES OF 85 TO 90 WITH SULTRY OVERNIGHT LOWS IN THE
MID TO UPPER 60S. THESE READINGS WILL BE MORE TYPICAL OF MID JULY.
ONE USUALLY CANNOT HAVE SULTRY CONDITIONS WITHOUT HAVING AT LEAST
THE THREAT FOR CONVECTION...AND THAT WILL BE THE CASE AS WE ADVANCE
THROUGH THE END OF THE WEEK. WHILE THE VAST MAJORITY OF THE TIME
WILL BE RAIN-FREE...THERE WILL BE THE RISK FOR THUNDERSTORMS THAT
WILL BE FOCUSED MAINLY NEAR LAKE BREEZE BOUNDARIES. DIGGING INTO THE
DETAILS...
THE CREST OF A H5 RIDGE ARCHING BACK ACROSS EASTERN ONTARIO AND THE
LOWER GREAT LAKES FROM THE MID ATLANTIC COAST WILL PROVIDE US WITH A
WARM AND DRY THURSDAY NIGHT. ENERGY EJECTING OUT OF A CLOSED LOW
OVER THE NORTHERN PLAINS WILL START TO FLATTEN THIS RIDGE AXIS ON
FRIDAY THOUGH...AND THIS MAY BE JUST ENOUGH TO HELP WEAKEN A
SUBSIDENCE INVERSION THAT WAS A SIGNIFICANT INHIBITOR TO CONVECTION
FROM THE DAY BEFORE. SBCAPES OF 1500 J/KG ARE EXPECTED ACROSS THE
SRN TIER FRIDAY AFTERNOON...AND WITH A WEAKENED CAP AND A LAKE
BREEZE BOUNDARY FORECAST TO BE MOVING EAST...THERE WILL BE THE
CHANCE FOR SOME THUNDERSTORMS FOR SITES GENERALLY EAST OF A LINE
FROM BATAVIA TO JAMESTOWN. WHILE THE WIND FIELDS DO NOT SUPPORT A
SOLID THREAT FOR SEVERE WEATHER...ANY STORMS THAT DEVELOP NEAR THE
LAKE BREEZE BOUNDARY COULD BECOME ROBUST ENOUGH TO PRODUCE LOCALLY
GUSTY WINDS AND SMALL HAIL. OTHERWISE...THE BULK OF THE REGION WILL
BE RAIN FREE ON FRIDAY WITH AFTERNOON TEMPERATURES CLOSE TO 90 AWAY
FROM THE LAKES.
DIURNALLY INDUCED CONVECTION WILL DIE OFF FRIDAY EVENING...BUT
WILL KEEP SLGT CHC POPS IN PLACE OVERNIGHT TO COVER THE UNLIKELY
CHANCE FOR ACTIVITY THAT ACCOMPANIES ANY SHORTWAVES THAT LIFT ACROSS
THE FLATTENING H5 RIDGE. LIKE THE PREVIOUS NIGHT...IT WILL BE A WARM
AND MUGGY NIGHT ACROSS THE REGION WITH LOWS GENERALLY IN THE MID TO
UPPER 60S.
SATURDAY HAS THE POTENTIAL TO BE MORE UNSETTLED THAN FRIDAY. WE WILL
STILL HAVE A WARM UNSTABLE AIRMASS IN PLACE...BUT WE WILL ALSO FIND
OURSELVES WITHIN THE JET ENTRANCE REGION OF A 120KT H25 JET THAT
WILL BE STREAMING ACROSS ONTARIO AND THE UPPER GREAT LAKES. THE
ADDED SYNOPTIC LIFT TO AN INCREASINGLY BUOYANT AIRMASS COULD LEAD TO
MORE WIDESPREAD AFTERNOON CONVECTION. WHILE PORTIONS OF THE IAG
FRONTIER SHOULD ONCE AGAIN BE `SHADOWED` BY LAKE ERIE...WILL
INCREASE LOW CHC POPS FROM CONTINUITY BY ABOUT 10 POINTS OVER THE
REMAINDER OF THE FORECAST AREA. IT WILL ONCE AGAIN BE QUITE
WARM...BUT WE SHOULD HAVE A LITTLE MORE CLOUD COVER SO WILL MAX
TEMPS SHOULD BE A DEGREE OR TWO LOWER THAN THE PREVIOUS DAY.
A LONGWAVE TROUGH WILL EASE ACROSS THE UPPER GREAT LAKES SATURDAY
NIGHT WHILE A COMPLEX AREA OF LOW PRESSURE AND ASSOCIATED FRONTAL
SYSTEM WILL CROSS LOWER MICHIGAN AND SOUTHERN ONTARIO. THIS SHOULD
LEAD TO THE LIKELIHOOD OF SHOWERS AND THUNDERSTORMS OVERNIGHT...
ESPECIALLY OVER THE WESTERN COUNTIES.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
IT WILL CERTAINLY BE COOLER...AND TO MANY...MORE COMFORTABLE EARLY
NEXT WEEK. A SPLIT FLOW OVER NORTH AMERICA WILL INCLUDE A LONG WAVE
TROUGH OVER EASTERN CANADA...AND THIS ALLOW H85 TEMPS TO DROP OFF
INTO THE SINGLE DIGITS. BEFORE WE GET TO THAT POINT THOUGH...WE WILL
HAVE SOME VERY UNSETTLED CONDITIONS TO CONTEND WITH ON SUNDAY.
A WAVY FRONTAL SYSTEM WILL SINK ACROSS THE FORECAST AREA ON SUNDAY
AND THIS WILL PRODUCE FAIRLY WIDESPREAD SHOWERS AND THUNDERSTORMS.
GIVEN THE SLOW MOVEMENT OF THE FRONT AND PWAT VALUES IN EXCESS OF
1.5 INCHES...THERE WILL BE A HEIGHTENED RISK FOR SIGNIFICANT RAINS.
STUBBORN CLEARING IS EXPECTED IN THE WAKE OF THE FRONT SUNDAY
NIGHT...BUT AT LEAST IT WILL BE MORE TOLERABLE FOR SLEEPING WITH MIN
TEMPS FORECAST TO BE IN THE 50S.
THE BASE OF A DIGGING H5 TROUGH WILL SWING ACROSS TO THE NORTH OF LK
ONTARIO ON MONDAY...AND WHILE THE MAJORITY OF THE DAY WILL BE RAIN
FREE...WILL KEEP SLGT TO LOW CHC POPS FOR ANY NUISANCE SHOWER
ACTIVITY. THE HIGHEST CHANCE FOR SHRA`S WILL BE FOUND IN THE
AFTERNOON ACROSS THE NORTH COUNTRY. HIGH TEMPERATURES WILL ONLY BE
IN THE 60S.
EXPANSIVE CANADIAN HIGH PRESSURE SHOULD THEN PROVIDE OUR REGION WITH
BEAUTIFUL WEATHER TUESDAY AND WEDNESDAY...AS BOUNTIFUL SUNSHINE WILL
BE ACCOMPANIED BY HIGH TEMPERATURES IN THE LOWER 70S.
&&
.AVIATION /01Z THURSDAY THROUGH MONDAY/...
EXPECT MAINLY VFR CONDITIONS THROUGH THIS EVENING. A WEAK
DISTURBANCE WILL PASS DURING THE EARLY MORNING HOURS...BRINGING A
MINIMAL CHANCE FOR SHOWERS AND POSSIBLY A THUNDERSTORM. LATE
OVERNIGHT THE IS A CHANCE OF MVFR VSBYS IN LIGHT FOG TIL JUST
AFTER DAYBREAK...THEN VFR THROUGH THE DAY ON THURSDAY.
OUTLOOK...
THURSDAY NIGHT THROUGH SATURDAY...MAINLY VFR.
SUNDAY...MVFR WITH RAIN SHOWERS.
MONDAY...VFR.
&&
.MARINE...
SOUTHWEST WINDS WILL SLACKEN A BIT OVERNIGHT WITH FEWER GUSTS AND
SPEEDS FALLING TO AROUND 10 KNOTS. UPPER LEVEL RIDGING AND SURFACE
HIGH PRESSURE WILL KEEP LIGHT WINDS ACROSS THE EASTERN LAKES FOR THE
NEXT FEW DAYS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...WCH
NEAR TERM...APFFEL/WCH
SHORT TERM...RSH
LONG TERM...RSH
AVIATION...APFFEL/WCH
MARINE...APFFEL/WCH
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
338 PM EDT TUE MAY 28 2013
.SYNOPSIS...
A WARM FRONT WILL MOVE THROUGH THE AREA OVERNIGHT BRINGING WITH IT
A ROUND OF SHOWERS AND THUNDERSTORMS. BEHIND THE FRONT A LINGERING
CHANCE OF THUNDERSTORMS WILL EXIST WEDNESDAY AFTERNOON...SOME OF WHICH
COULD CONTAIN GUSTY WINDS. WE WILL EXPERIENCE DRIER WEATHER
THURSDAY AND FRIDAY BUT IT WILL BE HOT WITH TEMPERATURES WELL INTO
THE 80S TO NEAR 90.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
330 PM UPDATE...
THE STEADIEST OF THE RAIN IS MOVING TO OUR EAST NOW. WILL MAINTAIN
LOW CHANCE TO SLIGHT CHANCE POPS THROUGH THE EVENING HOWEVER
BECAUSE WHILE MOST WILL SEE A LULL IN PRECIPITATION...ENOUGH SCT.
SHOWERS EXISTS AROUND TO WARRANT THESE POPS. MAIN ATTENTION
HOWEVER IS TO A LINE OF SHOWERS AND THUNDERSTORMS NOW NEAR
DETROIT. AS THE HRRR FIRST HINTED AT THIS MORNING...THE HIGHER
RESOLUTION MODELS SUCH AS THE ARW AND NMM ARE NOW FOLLOWING
CLOSELY BRINGING THIS AREA OF SHOWERS AND THUNDERSTORMS ACROSS
LAKE ERIE AND INTO OUR AREA. AT FIRST IT APPEARED THE MODELS MAY
BE TOO FAR NORTH WITH THIS FEATURE WITH THE BEST INSTABILITY
VALUES TO OUR SOUTHWEST OVER WESTERN PA. HOWEVER BASED ON WHAT IS
HAPPENING NOW...IT APPEARS THE CONVECTION WILL RIDE ALONG THE
NORTHERN GRADIENT OF THE INSTABILITY...WHICH WILL FAVOR THE FINGER
LAKES AND CENTRAL NEW YORK BETWEEN 03Z AND 07Z. THE SOUTHERN EDGE
OF THE PRECIP SHOULD BE THE SOUTHERN TIER OF NY...WITH NOT AS MUCH
HAPPENING FARTHER SOUTH TOWARD KAVP. THUNDER IS LIKELY WITH THIS
AREA OF RAIN AS IT MOVES EAST. WHILE SURFACE BASED CAPES ARE EITHER 0
OR JUST A FEW HUNDRED J/KG...WE ARE SEEING LIGHTNING NOW NEAR
DETROIT WITH THE SAME VALUES. IN ADDITION SHOWALTER VALUES GO
NEGATIVE OVERNIGHT. ALL AND ALL LOOKING AT A 2 TO 4 HOUR PERIOD OF
HEAVIER RAIN WITH THUNDER A GOOD BET. AS THE WARM FRONT LIFTS
THROUGH OUR AREA CHANCES FOR POPS WILL DECREASE TOWARD DAYBREAK
WHILE LIFTING NORTHEAST TOWARD THE MOHAWK VALLY.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY NIGHT/...
330 PM UPDATE...
THE AREA REMAINS IN A SLIGHT RISK FOR SEVERE WEATHER WEDNESDAY AND
IT HAS BEEN EXPANDED A BIT FARTHER SOUTH THAN THE EARLY MORNING
UPDATE FROM SPC. IT STILL APPEARS THE BEST THREAT FOR STORMS WILL
BE DURING THE AFTERNOON AND FROM THE NORTHERN TIER COUNTIES OF PA
NORTH THROUGH CNY WHICH WILL BE CLOSER TO THE BEST UPPER LEVEL LIFT.
MOST IF NOT ALL OF THE AREA SHOULD BE IN THE WARM SECTOR WITH THE
WARM FRONT EITHER ACROSS OUR FAR NORTHEAST IF NOT OVER NNY. THIS
COMBINED WITH A SHORT WAVE MOVING CLOSE BUT JUST TO OUR NORTH AND
0-6 KM BULK SHEAR VALUES OF 30 KTS GIVE US THE POTENTIAL FOR
DAMAGING WINDS AND HAIL. HIGHER RESOLUTION MODELS AT THIS EARLY
STAGE POINT TOWARD A LINEAR SQUALL LINE MOVING THROUGH BETWEEN 18Z
AND 0Z. WILL CONTINUE WITH HIGH CHANCE TO LIKELY POPS AND CONTINUE
TO MENTION GUSTY WINDS IN THE FORECAST AND HWO.
AFTER THE CONVECTION DIES DOWN WEDNESDAY EVENING...THE MAIN STORY
WILL BE THE HEAT BUILDING INTO OUR AREA. WHILE BOTH THE NAM AND
GFS SUGGEST LOW CHANCE POPS LATE THURSDAY AFTERNOON ACROSS THE
NORTH AND FRIDAY AFTERNOON OVER WESTERN NY...A DEVELOPING CAP
AROUND 10KT SHOULD KEEP OUR IMPRESSIVE CAPE VALUES FROM BEING A
PROBLEM. 850 TEMPS BETWEEN 15C TO 18C SUPPORT HIGHS WELL INTO THE
80S BOTH DAYS...WITH NEAR 90 OR LOWER 90S LIKELY ESPECIALLY BY
FRIDAY IN THE LOWER ELEVATIONS.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
220 PM UPDATE...
VRY FEW CHGS NEEDED TO LONG TERM FCST THIS AFTN. ONLY TWEAK WAS
TO INCRS POPS AS IT LOOKS TO BE FAIRLY REASONABLE THAT ALL MODELS,
INCLUDING ENSEMBLES, SHOWING FROPA OCCURRING ARND 12Z MONDAY.
THUS, HV BOOSTED POPS TO LKLY SUN NGT FOR STARTERS THO THESE MAY
NEED TO BE TWEAKED WITH LATER FCSTS.
MED RANGE GUIDANCE ALSO HINTING THAT TROFFING WL BE MVG TWD THE
WRN LAKES ON SUN NGT. WITH THIS FEATURE MVG CLOSER TO CWA, CLDS WL
OVRSPRD THE REGION DRG THE DAY SUNDAY WITH SLGTLY COOLER TEMPS
EXPECTED, THO STILL ABV NORMAL.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
18Z UPDATE...
IFR CONDITIONS AT KELM AND KBGM TERMINALS THIS AFTERNOON WITH
SIGNIFICANT MOISTURE TRAPPED UNDER LOW-LEVEL INVERSION. AREA OF
LIGHT TO MODERATE RAIN MOVING THROUGH WITH MVFR-IFR RESTRICTIONS.
ONCE THIS RAIN MOVES THROUGH, A BREAK IS EXPECTED WITH POTENTIAL
RETURN TO MVFR BEFORE NEXT SYSTEM ROLLS THROUGH AFTER 04Z. STILL A
LITTLE UNCERTAINTY AS TO HOW MUCH RAIN WILL AFFECT KITH/KELM/KBGM
AND KAVP, THUS HAVE LEFT PCPN MENTION OUT OF THESE TERMINALS AT
THIS TIME. FURTHER NORTH AT KSYR AND KRME HAVE INCLUDED SHOWER
MENTION THROUGH THE END OF THE TAF PERIOD WITH POSSIBLE -TSRA
BETWEEN 03Z AND 07Z.
WINDS AROUND 10KTS OUT OF THE ESE WITH GRADUALLY SHIFT AROUND TO
THE SOUTHWEST BY 12Z BETWEEN 10-15KTS.
OUTLOOK...
WED...MVFR IN SCT SHRA/TSRA.
THU-SAT...MAINLY VFR.
SUN...POTENTIAL FOR MVFR IN SHRA/TSRA AS COLD FRONT APPROACHES.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...HEDEN
NEAR TERM...HEDEN
SHORT TERM...HEDEN
LONG TERM...PVN
AVIATION...PVN
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
232 PM EDT TUE MAY 28 2013
.SYNOPSIS...
BERMUDA HIGH PRESSURE WILL BECOME WELL ESTABLISHED...BRINGING A
RETURN TO SUMMERTIME HEAT INTO EARLY NEXT WEEK. SHOWERS AND
THUNDERSTORMS MAY DEVELOP DURING THE HEAT OF THE DAY BY THE WEEKEND.
A COLD FRONT WILL APPROACH FROM THE WEST LATE MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM TUESDAY...IMPRESSIVE WV IMAGERY THIS AFTN PAINTS THE
PICTURE ACROSS THE SOUTHEAST. EXPANSIVE AREA OF CONVECTION DRAPED
FROM NORTHERN MEXICO...INTO IOWA...AND EAST INTO NEW
ENGLAND...BOUNDS THE WESTERN AND NORTHERN PERIPHERY OF AN UPPER
RIDGE CONTROLLING THE SYNOPTIC REGIME OVER THE SOUTHEAST.
WHILE CU HAS BEEN WIDESPREAD THIS AFTN...VERTICAL DEPTH OF THE
CLOUDS IS QUITE LIMITED THANKS TO WEAK FORCING AND INCREASING
CONVECTIVE LID BENEATH BUILDING THERMAL RIDGE ALOFT. HAVE KEPT POP
JUST BELOW THRESHOLD FOR THE REST OF THE DAY. HRRR CONTINUING TO
SUGGEST SOME ISOLATED SHOWERS TODAY...BUT IT CONTINUES TO BE OVER
AGGRESSIVE IN DEVELOPING DEEP CONVECTION SO HAVE IGNORED IT AND
LEANED ON ARW/NAM WHICH KEEP TODAY DRY. CONVECTIVE/DIURNAL CU WILL
SLOWLY ERODE THIS AFTN/EVE...AND ALTHOUGH THERE MAY BE SOME HIGH
LEVEL DEBRIS CLOUDINESS...OVERALL A MOSTLY CLEAR NIGHT IS EXPECTED.
WITH DEWPOINTS SURGING THIS AFTN ON MOIST SE FLOW...CROSSOVER TEMPS
WILL BE APPROACHED TONIGHT. ATTM DO NOT EXPECT THEM TO BE EXCEEDED
HOWEVER...MINS FALLING ONLY INTO THE MID/UPR 60S...AND THIS COMBINED
WITH 15 KTS OF WIND JUST ABOVE THE NOCTURNAL INVERSION WILL INHIBIT
WIDESPREAD FOG. STILL...HAVE LEFT SOME PATCHY FOG IN THE WX GRIDS
AFTER MIDNIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 230 PM TUESDAY...BUILDING RIDGE ALOFT AND THE ESTABLISHMENT OF
THE BERMUDA HIGH WILL LEAD TO A BENIGN SHORT TERM PERIOD. TEMPS WILL
PRIMARILY BE PERSISTENCE WITH HIGHS IN THE MID/UPPER 80S ACROSS THE
PEE DEE/LBT AREAS AND LOWER 80S COASTAL SECTIONS (NEAR 80 BEACHES)
EACH DAY. MEANWHILE EXPECT LIGHT ONSHORE FLOW TO TO SUPPORT LOWS IN
THE LOWER TO MID 60S EACH NIGHT. COULD SEE PATCHY FLOG EACH
MORNING...WITH POSSIBLY SOME STRATUS FOR A BRIEF PERIOD LATE
THURSDAY NIGHT.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 230 PM TUESDAY...FRIDAY APPEARS TO OFFER A CONVECTIVE MINIMUM
THROUGH THE PERIOD. THE BERMUDA HIGH WILL BE PUMPING WARMTH AND
MOISTURE ACROSS THE REGION BUT UPPER RIDGING MAY HAVE JUST ENOUGH AN
INFLUENCE AT CAPPING ALL BUT ISO COVERAGE. NOT SEEING MUCH EVIDENCE
OF PIEDMONT TROUGH SO IT MAY BE CONFINED TO THE SEA BREEZE. OVER THE
WEEKEND THE UPPER RIDGE MOVES EASTWARD AND RELAXES ITS SUPPRESSING
EFFECTS ON CONVECTION. COVERAGE MAY STILL BE ISOLATED IN THE ABSENCE
OF ANYTHING BUT MESOSCALE FORCING AND SO THE SEA BREEZE SEEMS THE
MOST LIKELY CULPRIT. SHOULD THE APPROACHING UPPER TROUGH BE QUICK
ENOUGH IT MAY SPREAD SW INCREASING WINDS OVER MAINLY WRN ZONES TO
ENHANCE POPS THERE BUT WITH THE ANTECEDENT RIDGE THINK IT/LL BE
SLOWER. IN FACT THE EFFECTS OF THE DOWNSTREAM RIDGE CAN BE SEEN IN
THE WAY GUIDANCE HANDLES THE APPROACH OF THE TROUGH...IT BECOMES
GRADUALLY POSITIVELY TILTED WITH TIME. AS A RESULT INTO NEXT WEEK
THE FRONT IT DRIVES DECELERATES. ITS PROXIMITY TO OUR NW COULD
FUNNEL EXTRA MOISTURE INTO THE CAROLINAS FOR SOME SLIGHTLY HIGHER
COVERAGE OF THUNDERSTORMS EACH AFTERNOON. TRUE TO A WARM SEASON
PATTERN THERE ARE LITTLE DAY TO DAY VARIATIONS IN TEMPERATURES
EITHER FROM ONE ANOTHER OR FROM CLIMO.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...BERMUDA HIGH WILL KEEP US IN SOUTHERLY FLOW THROUGH THE
FORECAST PERIOD. LOOK FOR SCATTERED CU ALONG AND WEST OF THE SEA
BREEZE RESULTANT THIS AFTERNOON. THE HRRR MODEL IS SHOWING SCATTERED
SHOWERS...BUT FEEL THEY WILL BE ISOLATED AT BEST. SOUTH SOUTHEAST
FLOW WILL DIMINISH THIS EVENING. SOME FOG IS POSSIBLE JUST BEFORE
SUNRISE...BUT GIVEN THE WINDS AT THE BOUNDARY LAYER ARE AROUND 15
KTS...THINK ANY FOG WILL BE QUITE LIGHT. WEDNESDAY...CONTINUED VFR
WITH MORE OF A SOUTHWEST COMPONENT.
EXTENDED OUTLOOK...MORNING MVFR/ISOLATED IFR FOG THROUGH SUNDAY.
ISOLATED SHOWERS SATURDAY AND SUNDAY...MAINLY WEST.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM TUESDAY...OFFSHORE HIGH PRESSURE TO CONTINUE TO
DOMINATE THE SYNOPTIC ENVIRONMENT...CREATING RELATIVELY WEAK SE
WINDS OVER THE WATERS. BUOYS TODAY HAVE SHOWN WINDS REMAINING BELOW
10 KTS...AND EXPECT THESE TO REMAIN ROUGHLY UNCHANGED THROUGH THE
PERIOD. WITH THE LIGHT WINDS...WIND-WAVE CONTRIBUTION TO THE
SPECTRUM IS LIMITED...SO A 2-3FT/9SEC SE SWELL WILL DOMINATE AND
WAVES WILL REMAIN 2-3 FT THROUGH TONIGHT.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 230 PM TUESDAY...BERMUDA HIGH PRESSURE IN A STAGNANT PATTERN
WILL KEEP THE FLOW OUT OF A SOUTHEAST TO SOUTH DIRECTION THROUGH THE
SHORT TERM PERIOD. THE PRESSURE GRADIENT IS NOT OVERLY IMPRESSIVE
AND SPEEDS WILL BE AROUND 10 KNOTS. GIVEN THE FETCH EXPECT SEAS TO
RANGE FROM 2-3 FT THROUGH THE PERIOD AS WELL.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 230 PM TUESDAY...SE FLOW AROUND BERMUDA HIGH PRESSURE ON
FRIDAY WILL VEER SLIGHTLY TO S FOR THE REMAINDER OF THE PERIOD AS
THE HIGHS RIDGE AXIS RETREATS SLIGHTLY OUT TO SEA. OTHER THAN THAT
SMALL VEER THERE SHOULD BE LITTLE VARIATION IN WIND AND/OR SEAS
THROUGH MOST OF THE PERIOD AS THE HIGH REMAINS QUASI-STATIONARY.
SEAS WILL BE IN THE 2 TO 4 FT RANGE WITH THE HIGHEST VALUES LOCATED
OFF THE COAST.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...JDW
SHORT TERM...SRP
LONG TERM...MBB
AVIATION...43/JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
121 PM EDT TUE MAY 28 2013
.SYNOPSIS...
BERMUDA HIGH PRESSURE WILL BECOME WELL ESTABLISHED...BRINGING A
RETURN TO SUMMERTIME HEAT INTO EARLY NEXT WEEK. SHOWERS AND
THUNDERSTORMS MAY DEVELOP DURING THE HEAT OF THE DAY BY THE WEEKEND.
A COLD FRONT WILL APPROACH FROM THE WEST LATE MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM TUESDAY...BEAUTIFUL DAY BEGINNING ACROSS THE CAROLINAS
AS COMBINATION OF BERMUDA HIGH AND BUILDING UPPER RIDGE COMBINE TO
PRODUCE PARTLY CLOUDY SKY CONDITIONS AND SEASONABLE TEMPERATURES.
WV IMAGERY THIS MORNING SHOWS CLEARLY THE LARGE AREA OF HIGH
PRESSURE CENTERED OFFSHORE...WITH MOISTURE AND CONVECTION ROTATING
AROUND ITS PERIPHERY...FROM TEXAS TO IOWA TO PENNSYLVANIA. SE OF
THIS BOUNDARY...BULGING THICKNESSES WILL CAP THE MAJORITY OF
CONVECTION TODAY. HOWEVER...VERY WARM SURFACE TEMPS...LOW TO MID 80S
ACROSS THE AREA...WILL CREATE ENOUGH INSTABILITY THAT PARCELS WILL
BECOME BUOYANT THIS AFTN AND RISE TOWARDS THE CONVECTIVE LID. WHILE
THIS HAPPENS...THE ENTIRE COLUMN BEGINS TO WARM THANKS TO INCREASING
MID-LEVEL THERMAL RIDGING...SO IT WILL BE A RACE BETWEEN SURFACE
BASED INSTABILITY AND MID-LEVEL WARMING TO DETERMINE WHETHER SHOWERS
CAN DEVELOP TODAY. CURRENTLY...ONLY THE HRRR DEPICTS ANY SHOWERS
TODAY...FOCUSED ALONG THE INLAND PENETRATING SEA BREEZE. WHILE IT IS
LOGICAL THAT ONLY THE SEA BREEZE WILL BE ABLE TO TRIGGER CONVECTION
STRONG ENOUGH TODAY TO PUSH THROUGH THE LID (HENCE WHY THE TERM CAP
IS NOT BEING USED)...THIS MODEL HAS BEEN OVER-AGGRESSIVE THE PAST
FEW DAYS. HAVE INHERITED JUST-BELOW-THRESHOLD POP...AND CHOOSE TO
LEAVE UNCHANGED FOR NOW. CANNOT RULE OUT AN ISOLATED SHOWER THIS
AFTN...BUT WILL HANDLE THIS WITH NEAR-TERM UPDATES AS REQUIRED.
SLIGHTLY STRONGER WINDS TODAY WILL ALSO BE NOTICED AS GRADIENT IS
JUST A BIT STRONGER AROUND THE OFFSHORE HIGH PRESSURE. THE STRONGEST
WINDS WILL BE WITHIN THE RESULTANT THIS AFTN...WHERE WIND GUSTS TO
20 MPH WILL BE FREQUENT FOR A FEW HOURS. WINDS WILL EASE AFTER
SUNSET BENEATH THE DEVELOPMENT OF THE NOCTURNAL INVERSION...BUT
CONTINUED LIGHT SOUTHERLY WINDS...UP TO 15 KTS AT THE TOP OF THE
INVERSION...WILL KEEP MINS ELEVATED TONIGHT AS THEY WILL FALL ONLY
INTO THE MID 60S. HAVE LEFT SOME PATCHY FOG IN THE WX GRIDS SINCE
CROSSOVER TEMPS MAY BE MET TONIGHT THANKS TO LONG-DURATION MOIST
ADVECTION OFF THE OCEAN TODAY...BUT WIDESPREAD FOG IS NOT EXPECTED.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 AM TUESDAY...BERMUDA HIGH PRESSURE WILL RIDGE BACK INTO
THE CAROLINAS THROUGH MID WEEK. THIS WILL PRODUCE A WARM MOIST
SOUTHERLY RETURN FLOW WITH SFC DEWPOINT TEMPS UP IN THE 60S.
ALTHOUGH MORE HUMID SUMMER-LIKE CONDITIONS WILL EXIST...LOCALIZED
AFTERNOON CONVECTION WILL BE SUPPRESSED BY BUILDING RIDGE ALOFT.
THIS WILL KEEP VERY DRY AIR THROUGH THE LOW TO MID LEVELS
BASICALLY ABOVE 4K FT. THE PCP WATER VALUES WILL ONLY BE AROUND AN
INCH THROUGH THE PERIOD. EXPECT SEASONABLE TEMPS IN THE MID 80S
MOST PLACES DURING THE DAY EXCEPT COOLER AT THE BEACHES. OVERNIGHT
TEMPS WILL REMAIN IN THE MID 60S. MAY SEE SOME CU DEVELOP ALONG
SEA BREEZE BOUNDARY AS IT PUSHES INLAND EACH DAY BUT OTHERWISE
WILL SEE PLENTY OF SUNSHINE.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 3 AM TUESDAY...BERMUDA HIGH PRESSURE WILL CONTINUE TO RIDGE
BACK ACROSS THE CAROLINAS THROUGH EARLY NEXT WEEK. THE STRONG
RIDGE ALOFT WILL SLIP TO THE EAST THROUGH THE WEEKEND LOSING ITS
GRIP OVER THE SOUTHEAST. THIS WILL LEAD THE WAY TO INCREASED CHC
OF LOCALIZED CONVECTION BUT WITHOUT MUCH FORCING ALOFT WOULD
EXPECT MORE IN THE WAY OF CU BUILDING IN CONVERGENCE ALONG SEA
BREEZE BOUNDARY AS IT PUSHES INLAND EACH AFTERNOON. OTHERWISE WILL
CONTINUE WITH WARM AND HUMID WEATHER WITH GOOD DEAL OF SUNSHINE
THROUGH THE WEEKEND.
BY LATE MONDAY MID TO UPPER TROUGH WILL PUSH A COLD FRONT EAST.
THEREFORE EXPECT MORE WIDESPREAD SHWR/TSTM ACTIVITY AHEAD AND
ALONG THIS FRONT LATE MONDAY INTO EARLY TUESDAY.
TEMPERATURES WILL BE NEAR OR SLIGHTLY ABOVE NORMAL THROUGH THE
PERIOD WITH OVERNIGHT LOWS IN THE MID 60S AND DAY TIME HIGHS IN
THE MID TO UPPER 80S.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...BERMUDA HIGH WILL KEEP US IN SOUTHERLY FLOW THROUGH THE
FORECAST PERIOD. LOOK FOR SCATTERED CU ALONG AND WEST OF THE SEA
BREEZE RESULTANT THIS AFTERNOON. THE HRRR MODEL IS SHOWING SCATTERED
SHOWERS...BUT FEEL THEY WILL BE ISOLATED AT BEST. SOUTH SOUTHEAST
FLOW WILL DIMINISH THIS EVENING. SOME FOG IS POSSIBLE JUST BEFORE
SUNRISE...BUT GIVEN THE WINDS AT THE BOUNDARY LAYER ARE AROUND 15
KTS...THINK ANY FOG WILL BE QUITE LIGHT. WEDNESDAY...CONTINUED VFR
WITH MORE OF A SOUTHWEST COMPONENT.
EXTENDED OUTLOOK...MORNING MVFR/ISOLATED IFR FOG THROUGH SUNDAY.
ISOLATED SHOWERS SATURDAY AND SUNDAY...MAINLY WEST.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM TUESDAY...MINIMAL CHANGES WITH THIS UPDATE OTHER THAN
SOME TWEAKS TO SEA-BREEZE BOUNDARY WINDS. PREVIOUS DISCUSSION BELOW:
AS OF 6 AM TUESDAY...BERMUDA HIGH PRESSURE WILL DOMINATE THROUGH THE
PERIOD. THE SEA BREEZE CIRCULATION WILL INTENSIFY DURING THE
AFTERNOON AND EARLY EVE...THEN DISSIPATE MID TO LATE EVE. S TO SSE
WINDS WILL BE STRONGEST ACROSS THE NEAR SHORE WATERS DUE TO SEA
BREEZE INFLUENCES...SUSTAINED AT UP TO 15 KT AND ON THE GUSTY SIDE
LATE AFTERNOON AND EARLY EVE. NO SIGNIFICANT LOW-LEVEL JETTING NOTED
FOR TONIGHT AND SO WINDS SHOULD DROP OFF DURING THE LATE EVE AND
OVERNIGHT. SE SWELL WILL ACTUALLY STRENGTHEN SLIGHTLY THIS PERIOD...
SEAS WILL RANGE FROM 2 TO 3 FT...LARGELY THE RESULT OF AN 8 TO 9
SECOND SE SWELL.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 AM TUESDAY...SOUTHERLY RETURN FLOW WILL CONTINUE AROUND
BERMUDA HIGH PRESSURE THROUGH MID WEEK. GRADIENT WILL REMAIN
FAIRLY RELAXED WITH WINDS 10 KTS OR LESS BUT SPIKING UP A BIT IN
SEA BREEZE EACH AFTERNOON. SEAS WILL GRADUAL BUILD FROM 1 TO 3 FT UP
TO 2 TO 4 FT IN PERSISTENT SOUTH TO SOUTHEAST SWELL AROUND THE HIGH.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 3 AM TUESDAY...SOUTHEASTERLY RETURN FLOW WILL CONTINUE
AROUND BERMUDA HIGH PRESSURE THROUGH THE PERIOD. GRADIENT WILL
CONTINUE TO BE FAIRLY RELAXED WITH WINDS HOLDING AROUND 10 KTS
THROUGH SATURDAY BUT INCREASING SLIGHTLY UP TO 10 TO 15 KTS BY
SUNDAY. THIS PERSISTENT SOUTHERLY PUSH WILL BUILD SEA GRADUALLY UP
TO 3 TO 4 FT IN THE OUTER WATERS AND CLOSER TO 2 FT NEAR SHORE.
WILL SEE SPIKE IN WINDS AND SLIGHT CHOP NEAR SHORE EACH AFTERNOON
IN SEA BREEZE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...JDW
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...43
AREA FORECAST DISCUSSION...COR
NWS WILMINGTON NC
1018 AM EDT TUE MAY 28 2013
.SYNOPSIS...
BERMUDA HIGH PRESSURE WILL BECOME WELL ESTABLISHED...BRINGING A
RETURN TO SUMMERTIME HEAT INTO EARLY NEXT WEEK. SHOWERS AND
THUNDERSTORMS MAY DEVELOP DURING THE HEAT OF THE DAY BY THE WEEKEND.
A COLD FRONT WILL APPROACH FROM THE WEST LATE MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM TUESDAY...BEAUTIFUL DAY BEGINNING ACROSS THE CAROLINAS
AS COMBINATION OF BERMUDA HIGH AND BUILDING UPPER RIDGE COMBINE TO
PRODUCE PARTLY CLOUDY SKY CONDITIONS AND SEASONABLE TEMPERATURES.
WV IMAGERY THIS MORNING SHOWS CLEARLY THE LARGE AREA OF HIGH
PRESSURE CENTERED OFFSHORE...WITH MOISTURE AND CONVECTION ROTATING
AROUND ITS PERIPHERY...FROM TEXAS TO IOWA TO PENNSYLVANIA. SE OF
THIS BOUNDARY...BULGING THICKNESSES WILL CAP THE MAJORITY OF
CONVECTION TODAY. HOWEVER...VERY WARM SURFACE TEMPS...LOW TO MID 80S
ACROSS THE AREA...WILL CREATE ENOUGH INSTABILITY THAT PARCELS WILL
BECOME BUOYANT THIS AFTN AND RISE TOWARDS THE CONVECTIVE LID. WHILE
THIS HAPPENS...THE ENTIRE COLUMN BEGINS TO WARM THANKS TO INCREASING
MID-LEVEL THERMAL RIDGING...SO IT WILL BE A RACE BETWEEN SURFACE
BASED INSTABILITY AND MID-LEVEL WARMING TO DETERMINE WHETHER SHOWERS
CAN DEVELOP TODAY. CURRENTLY...ONLY THE HRRR DEPICTS ANY SHOWERS
TODAY...FOCUSED ALONG THE INLAND PENETRATING SEA BREEZE. WHILE IT IS
LOGICAL THAT ONLY THE SEA BREEZE WILL BE ABLE TO TRIGGER CONVECTION
STRONG ENOUGH TODAY TO PUSH THROUGH THE LID (HENCE WHY THE TERM CAP
IS NOT BEING USED)...THIS MODEL HAS BEEN OVER-AGGRESSIVE THE PAST
FEW DAYS. HAVE INHERITED JUST-BELOW-THRESHOLD POP...AND CHOOSE TO
LEAVE UNCHANGED FOR NOW. CANNOT RULE OUT AN ISOLATED SHOWER THIS
AFTN...BUT WILL HANDLE THIS WITH NEAR-TERM UPDATES AS REQUIRED.
SLIGHTLY STRONGER WINDS TODAY WILL ALSO BE NOTICED AS GRADIENT IS
JUST A BIT STRONGER AROUND THE OFFSHORE HIGH PRESSURE. THE STRONGEST
WINDS WILL BE WITHIN THE RESULTANT THIS AFTN...WHERE WIND GUSTS TO
20 MPH WILL BE FREQUENT FOR A FEW HOURS. WINDS WILL EASE AFTER
SUNSET BENEATH THE DEVELOPMENT OF THE NOCTURNAL INVERSION...BUT
CONTINUED LIGHT SOUTHERLY WINDS...UP TO 15 KTS AT THE TOP OF THE
INVERSION...WILL KEEP MINS ELEVATED TONIGHT AS THEY WILL FALL ONLY
INTO THE MID 60S. HAVE LEFT SOME PATCHY FOG IN THE WX GRIDS SINCE
CROSSOVER TEMPS MAY BE MET TONIGHT THANKS TO LONG-DURATION MOIST
ADVECTION OFF THE OCEAN TODAY...BUT WIDESPREAD FOG IS NOT EXPECTED.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 AM TUESDAY...BERMUDA HIGH PRESSURE WILL RIDGE BACK INTO
THE CAROLINAS THROUGH MID WEEK. THIS WILL PRODUCE A WARM MOIST
SOUTHERLY RETURN FLOW WITH SFC DEWPOINT TEMPS UP IN THE 60S.
ALTHOUGH MORE HUMID SUMMER-LIKE CONDITIONS WILL EXIST...LOCALIZED
AFTERNOON CONVECTION WILL BE SUPPRESSED BY BUILDING RIDGE ALOFT.
THIS WILL KEEP VERY DRY AIR THROUGH THE LOW TO MID LEVELS
BASICALLY ABOVE 4K FT. THE PCP WATER VALUES WILL ONLY BE AROUND AN
INCH THROUGH THE PERIOD. EXPECT SEASONABLE TEMPS IN THE MID 80S
MOST PLACES DURING THE DAY EXCEPT COOLER AT THE BEACHES. OVERNIGHT
TEMPS WILL REMAIN IN THE MID 60S. MAY SEE SOME CU DEVELOP ALONG
SEA BREEZE BOUNDARY AS IT PUSHES INLAND EACH DAY BUT OTHERWISE
WILL SEE PLENTY OF SUNSHINE.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 3 AM TUESDAY...BERMUDA HIGH PRESSURE WILL CONTINUE TO RIDGE
BACK ACROSS THE CAROLINAS THROUGH EARLY NEXT WEEK. THE STRONG
RIDGE ALOFT WILL SLIP TO THE EAST THROUGH THE WEEKEND LOSING ITS
GRIP OVER THE SOUTHEAST. THIS WILL LEAD THE WAY TO INCREASED CHC
OF LOCALIZED CONVECTION BUT WITHOUT MUCH FORCING ALOFT WOULD
EXPECT MORE IN THE WAY OF CU BUILDING IN CONVERGENCE ALONG SEA
BREEZE BOUNDARY AS IT PUSHES INLAND EACH AFTERNOON. OTHERWISE WILL
CONTINUE WITH WARM AND HUMID WEATHER WITH GOOD DEAL OF SUNSHINE
THROUGH THE WEEKEND.
BY LATE MONDAY MID TO UPPER TROUGH WILL PUSH A COLD FRONT EAST.
THEREFORE EXPECT MORE WIDESPREAD SHWR/TSTM ACTIVITY AHEAD AND
ALONG THIS FRONT LATE MONDAY INTO EARLY TUESDAY.
TEMPERATURES WILL BE NEAR OR SLIGHTLY ABOVE NORMAL THROUGH THE
PERIOD WITH OVERNIGHT LOWS IN THE MID 60S AND DAY TIME HIGHS IN
THE MID TO UPPER 80S.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 12Z...BERMUDA HIGH WILL KEEP US IN SOUTHERLY FLOW THROUGH THE
FORECAST PERIOD. FOG WAS LIGHTER THIS MORNING THAN ANTICIPATED. VFR
CONDITIONS WILL PREVAIL TODAY WITH ONLY MID AND HIGH CLOUDS
EXPECTED. THERE MAY BE SOME ISOLATED CU ALONG THE SEA BREEZE
BOUNDARY THIS AFTERNOON. LIGHT WINDS TONIGHT WITH NEARLY CLEAR
SKIES. SOME LIGHT FOG IS EXPECTED AT THE END OF THE FORECAST PERIOD.
EXTENDED OUTLOOK...MORNING MVFR/ISOLATED IFR FOG THROUGH SATURDAY.
OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM TUESDAY...MINIMAL CHANGES WITH THIS UPDATE OTHER THAN
SOME TWEAKS TO SEA-BREEZE BOUNDARY WINDS. PREVIOUS DISCUSSION BELOW:
AS OF 6 AM TUESDAY...BERMUDA HIGH PRESSURE WILL DOMINATE THROUGH THE
PERIOD. THE SEA BREEZE CIRCULATION WILL INTENSIFY DURING THE
AFTERNOON AND EARLY EVE...THEN DISSIPATE MID TO LATE EVE. S TO SSE
WINDS WILL BE STRONGEST ACROSS THE NEAR SHORE WATERS DUE TO SEA
BREEZE INFLUENCES...SUSTAINED AT UP TO 15 KT AND ON THE GUSTY SIDE
LATE AFTERNOON AND EARLY EVE. NO SIGNIFICANT LOW-LEVEL JETTING NOTED
FOR TONIGHT AND SO WINDS SHOULD DROP OFF DURING THE LATE EVE AND
OVERNIGHT. SE SWELL WILL ACTUALLY STRENGTHEN SLIGHTLY THIS PERIOD...
SEAS WILL RANGE FROM 2 TO 3 FT...LARGELY THE RESULT OF AN 8 TO 9
SECOND SE SWELL.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 AM TUESDAY...SOUTHERLY RETURN FLOW WILL CONTINUE AROUND
BERMUDA HIGH PRESSURE THROUGH MID WEEK. GRADIENT WILL REMAIN
FAIRLY RELAXED WITH WINDS 10 KTS OR LESS BUT SPIKING UP A BIT IN
SEA BREEZE EACH AFTERNOON. SEAS WILL GRADUAL BUILD FROM 1 TO 3 FT UP
TO 2 TO 4 FT IN PERSISTENT SOUTH TO SOUTHEAST SWELL AROUND THE HIGH.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 3 AM TUESDAY...SOUTHEASTERLY RETURN FLOW WILL CONTINUE
AROUND BERMUDA HIGH PRESSURE THROUGH THE PERIOD. GRADIENT WILL
CONTINUE TO BE FAIRLY RELAXED WITH WINDS HOLDING AROUND 10 KTS
THROUGH SATURDAY BUT INCREASING SLIGHTLY UP TO 10 TO 15 KTS BY
SUNDAY. THIS PERSISTENT SOUTHERLY PUSH WILL BUILD SEA GRADUALLY UP
TO 3 TO 4 FT IN THE OUTER WATERS AND CLOSER TO 2 FT NEAR SHORE.
WILL SEE SPIKE IN WINDS AND SLIGHT CHOP NEAR SHORE EACH AFTERNOON
IN SEA BREEZE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...JDW
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...43
AREA FORECAST DISCUSSION
NWS BISMARCK ND
938 PM CDT WED MAY 29 2013
.UPDATE...
ISSUED AT 938 PM CDT WED MAY 29 2013
ONCE AGAIN...GIVEN THE LATEST RADAR TRENDS...THE 18 AND INCOMING
00 UTC DETERMINISTIC GUIDANCE AND 01 UTC RAP/HRRR SIMULATED
REFLECTIVITY FORECASTS...REDUCED POPS THROUGH 06 UTC FOR MUCH OF
THE AREA UNTIL THE ARRIVAL OF GREATER UPPER LEVEL FORCING AS
CONVECTION ACROSS SOUTH DAKOTA THROUGH NEBRASKA MAY ALSO BE
DISRUPTING MOISTURE TRANSPORT INTO NORTH DAKOTA. DO NOT ANTICIPATE
SEVERE WEATHER TONIGHT ACROSS WESTERN AND CENTRAL NORTH
DAKOTA...WITH A POTENTIAL RETURN OF THE THREAT TOMORROW AFTERNOON
AND EVENING DEPENDENT UPON HOW MUCH CLEARING/INSOLATION IS
ACHIEVED IN THE WARM SECTOR OF THE SURFACE LOW ACROSS SOUTH
CENTRAL NORTH DAKOTA.
UPDATE ISSUED AT 720 PM CDT WED MAY 29 2013
THE BIGGEST CHANGE WITH THIS UPDATE WAS TO REDUCE POPS...ESPECIALLY
ALONG AND NORTH OF US HIGHWAY 2...GIVEN THE LATEST RADAR TRENDS
AND THE 21 UTC HRRR SIMULATED REFLECTIVITY WHICH HAS MAINTAINED
CONTINUITY WITH PREVIOUS RUNS WHICH KEEP MUCH OF NORTHERN NORTH DAKOTA
PRECIPITATION FREE THROUGH AT LEAST 06 UTC. GIVEN THE MARGINAL
INSTABILITY AND SHEAR...THE SMALL WINDOW FOR SEVERE HAIL AND/OR
WINDS ACROSS THE JAMES RIVER VALLEY APPEARS TO BE QUICKLY CLOSING
AND WILL FOCUS ON HEAVY RAIN MONITORING OVER THE SATURATED AREAS
OF SOUTHERN NORTH DAKOTA.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 405 PM CDT WED MAY 29 2013
MAIN PROBLEM IN THE SHORT TERM PERIOD WILL BE PRECIPITATION
AMOUNTS...PLACEMENT AND TIMING.
CURRENTLY...SURFACE LOW PRESSURE OVER THE CENTRAL PLAINS WITH A
WARM FRONT EXTENDING INTO EASTERN SOUTH DAKOTA AND SOUTHERN
MINNESOTA. STRONG NEGATIVELY TILTED UPPER LEVEL TROUGH FROM THE
NORTHWEST U.S. INTO THE CENTRAL ROCKIES. CURRENT CONVECTION IN OUR
AREA IS LINING UP WITH THE THE STRONG WARM ADVECTION OVER THE
EASTERN DAKOTAS INTO MINNESOTA...AS WELL AS STRONG UPPER LEVEL
DIVERGENCE OVER EASTERN MONTANA.
TONIGHT...THE UPPER LEVEL WAVE WILL LIFT NORTHWARD INTO THE
NORTHERN HIGH PLAINS WITH THE SURFACE LOW TRACKING NORTH THROUGH
SOUTH DAKOTA. THIS WILL BRING INCREASING SHOWERS AND POSSIBLY SOME
THUNDERSTORMS TO WESTERN AND CENTRAL NORTH DAKOTA. ALTHOUGH WE DO
THINK MOST AREAS WILL RECEIVE PRECIPITATION...WE HAVE CONTINUED
THE TREND OF DELAYING THE ONSET...AND CUTTING BACK A LITTLE ON THE
AMOUNTS. AGAIN..WE ARE IN A BIT OF A LULL BETWEEN THE STRONG WARM
ADVECTION TO OUR EAST...AND THE STRONG FORCING AND DIVERGENT FLOW
ALOFT ASSOCIATED WITH THE UPPER LEVEL SYSTEM TO OUR WEST.
THURSDAY...THE UPPER LEVEL LOW CONTINUES TO LIFT NORTH THROUGH
EASTERN MONTANA...WHILE THE SURFACE LOW LIFTS NORTH TO NEAR
BISMARCK...THEN NORTHWEST TOWARDS WILLISTON. THIS PLACEMENT WOULD
BRING GREATEST PRECIPITATION AMOUNTS TO THE NORTHERN HALF OF THE
CWA...WITH DRIER AIR WORKING FROM SOUTH TO NORTH THURSDAY
AFTERNOON. THIS WOULD BRING AN END TO PRECIPITATION ACROSS THE
SOUTH HALF OF THE CWA...BUT COULD ALSO ALLOW FOR A PERIOD OF
DESTABILIZATION THURSDAY AFTERNOON IN THE DRIER AIR. WITH THE
SURFACE AND UPPER LOWS JUST WEST...THIS WOULD INCREASE THE RISK OF
THUNDERSTORMS IN A HIGH SHEAR ENVIRONMENT. DUE TO SOME MODEL AND
TIMING UNCERTAINTIES WILL NOT MENTION SEVERE AT THIS TIME...AND
LET LATER SHIFTS UPDATE AS NEEDED.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 405 PM CDT WED MAY 29 2013
WET AND COOL WEATHER REMAINS OVER THE NORTHERN PLAINS THROUGH EARLY
SATURDAY...FOLLOWED BY QUIET CONDITIONS SATURDAY THROUGH SUNDAY
AFTERNOON...THEN A RETURN TO ACTIVE CONDITIONS SUNDAY NIGHT THROUGH
TUESDAY.
THE LONG TERM BEGINS THURSDAY EVENING WITH A CLOSED UPPER LEVEL LOW
CENTERED OVER SOUTHWEST ND/SOUTHEASTERN MONTANA...AND AN AREA OF
SURFACE LOW PRESSURE OVER WESTERN NORTH DAKOTA. ACTIVE WEATHER WILL
BE ONGOING AT THE START OF THE PERIOD WITH WIDESPREAD RAIN SHOWERS
AND ISOLATED THUNDERSTORMS ACROSS THE NORTH AND FAR WEST WRAPPING
AROUND THE UPPER LOW. OVER SOUTH CENTRAL AND SOUTHEASTERN NORTH
DAKOTA...A DRY SLOT IS EXPECTED TO PROVIDE SOME CLEARING THURSDAY
AFTERNOON INTO THURSDAY EVENING...WITH THE RESULTANT HEATING ACTING
TO INCREASE SURFACE INSTABILITY WITH UPWARDS TO NEAR 1500 J/KG OF
CAPE FORECAST NEAR A SFC COLD/OCCLUDED FRONT. MAY SEE ISOLATED
SEVERE STORMS DEVELOP GIVEN THE ADVERTISED INSTABILITY PERSISTING
INTO THE EVENING NEAR THE BOUNDARY.
LOW LINGERS ACROSS THE NORTHERN PLAINS THROUGH FRIDAY BEFORE
MORPHING INTO AN OPEN WAVE AND PUSHING OFF TO OUR EAST SATURDAY
AFTERNOON. AS THIS OCCURS...WILL SEE WRAP AROUND PRECIPITATION
SPREAD FROM WEST TO EAST FRIDAY MORNING THROUGH FRIDAY
EVENING...THEN DECREASING CLOUDS AND CHANCES FOR RAIN FROM
NORTHWEST TO SOUTHEAST FRIDAY NIGHT INTO SATURDAY. OVERALL EXPECT
UPWARDS TO AN ADDITIONAL ONE HALF INCH OF RAINFALL THURSDAY NIGHT
THROUGH SATURDAY MORNING ACROSS WEST AND CENTRAL ND.
DRY WEATHER REMAINS IN THE FORECAST SATURDAY NIGHT THROUGH SUNDAY
AFTERNOON WITH A SHORT WAVE RIDGE AND SURFACE HIGH PRESSURE BUILDING
EAST ACROSS THE NORTHERN PLAINS. ACTIVE WEATHER RESUMES SUNDAY NIGHT
INTO EARLY NEXT WEEK AS ANOTHER UPPER LOW/TROUGH PUSHES ACROSS THE
NORTHERN ROCKIES AND EVENTUALLY INTO THE NORTHERN PLAINS.
WELL BELOW NORMAL TEMPERATURES FRIDAY AND SATURDAY WITH HIGHS 55-65
AND LOWS IN THE UPPER 30S TO MID 40S. WILL NEED TO MONITOR FOR
POSSIBLE FROST SATURDAY NIGHT/SUNDAY MORNING WHEN WINDS ARE EXPECTED
TO BE LIGHT...SKIES CLEAR...AND SFC DEWPOINT TEMPS FORECAST TO FALL
AS LOW AS 35F DEGREES SOME AREAS. DAYTIME AND NIGHTTIME TEMPERATURES
MODERATE TOWARDS NORMAL SUNDAY-TUESDAY WITH HIGHS GENERALLY IN THE
60S AND LOW 45-55.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY)
ISSUED AT 938 PM CDT WED MAY 29 2013
SHOWERS AND THUNDERSTORMS WILL INCREASE IN COVERAGE ACROSS
WESTERN AND CENTRAL NORTH DAKOTA THROUGH THE NIGHT...WITH FLIGHT
CONDITIONS TRENDING TOWARDS IFR AT KDIK...KMOT AND KISN IN
MODERATE RAIN LATE TONIGHT...AND MVFR AT KBIS AND KJMS. DEPENDING
ON HOW MUCH CLEARING THERE IS THURSDAY AFTERNOON...STRONG TO
SEVERE THUNDERSTORMS MAY BE POSSIBLE FOR THE KDIK...KBIS AND KJMS
TAF SITES THURSDAY AFTERNOON AND EVENING.
&&
.HYDROLOGY...
ISSUED AT 405 PM CDT WED MAY 29 2013
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP LATE THIS
AFTERNOON AND TONIGHT...AND MOVE FROM SOUTH TO NORTH ACROSS
WESTERN AND CENTRAL NORTH DAKOTA THROUGH THURSDAY AFTERNOON.
THE POTENTIAL FOR HEAVY RAIN EXISTS ACROSS THE WEST AND CENTRAL...
ESPECIALLY LATE TONIGHT THROUGH THURSDAY. WIDESPREAD RAINFALL
AMOUNTS OF THREE QUARTERS OF AN INCH...TO TWO INCHES ARE FORECAST
THOUGH THIS PERIOD. HOWEVER...THE LATEST GUIDANCE CONTINUES TO
SUGGEST A LESS LIKELY SCENARIO FOR AMOUNTS GREATER THAN 1.5 INCHES
OVER MUCH OF THE CENTRAL. THE MOST LIKELY AREAS FOR THE HIGHEST
AMOUNTS APPEAR TO BE IN THE FAR NORTH AND FAR WEST...WITH THE
HIGHEST AMOUNTS IN EASTERN MONTANA AND SOUTHERN CANADA.
STREAM AND RIVER RISES ARE POSSIBLE BY THE END OF THE WEEK INTO
THIS COMING WEEKEND. AN ADDITIONAL ONE QUARTER TO ONE HALF INCH
WILL BE POSSIBLE FRIDAY AND FRIDAY NIGHT. CHANCES FOR RAIN
DECREASE SATURDAY INTO SATURDAY NIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...TWH
LONG TERM...NH
AVIATION...AYD
HYDROLOGY...TWH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
730 PM CDT WED MAY 29 2013
.UPDATE...
ISSUED AT 716 PM CDT WED MAY 29 2013
MAIN CHALLENGE WITH UPDATE IS POP TIMNG AND WHAT CHANGES TO MAKE.
OVERALL LEAD SHORT WAVE PRODUCING AREA OF SHOWERS AND ISOLD
THUNDER FROM SE ND INTO NRN MN. THIS ACTIVITY HAS CONTINUED TO
MOVE NORTHEAST PAST SEVERAL HOURS AND SHOULD REMAIN SOUTHOF A BDE-
GFK LINE. NORTHWEST OF THIS AREA GENERALLY DRY AND LOOKS LIKE IT
SHOULD REMAIN SO THRU 06Z. OTHER ISOLD CELLS POPPING UP IN ERN SD
SOUTHEAST OF ABERDEEN OVER TOWARD MILBANK. THIS WILL MOVE NORTH-
NORTHEAST AS WELL.
FOR THE TONIGHT TRENDS IN PRECIP...NOT REAL SURE WHAT TO EXPECT.
850 MB LOW LEVEL JET IS REALLY FOCUSED OVER ERN KS INTO WRN IOWA
EARLY EVE WITH 35 KTS OR SO INTO FAR ERN SD/WCNTRL MN EARLY THIS
EVE. THEN THE LOW LEVEL JET INTENSIFIES BUT ALSO SHIFTS MORE EAST
WITH MAIN AXIS FROM ERN KS THRU IOWA INTO SE MN/WI. THUS THIS
MIGHT SUGGEST MAIN ACTION TO REMAIN SOUTH AND SOUTHEAST OF OUR
REGION. CURRENTLY LARGE SVR MCS MOVING INTO SW WISCONSIN WITH HVY
RAIN IN SE MN/NE IA. ALSO GOT SECOND AREA OF RAIN MORE SO NORTH OF
UPPER LOW WHICH IS IN EAST CENTRAL WYOMING FROM NW SD INTO CNTRL
MT. UPPER LOW WILL LIFT NORTH SLOWLY TONIGHT INTO THURSDAY INTO
WRN ND KEEPING ERN MT VERY WET. HOW MUCH RAIN OCCURS IN CNTRL-ERN
ND INTO NW/WCNTRL MN TONIGHT INTO THURSDAY IN BETWEEN UPPER LEVEL
LOW DYNAMICS AND LOW LEVEL JET IS A BIT SUSPECT. FOR THE TIME
BEING WILL GO MOSTLY SCT THUNDER IN SE ND/WCNTRL MN THIS EVE THEN
KEEP IDEA OF LIKELY POPS MOST AREAS AFTER 06Z. SEVERE THREAT LOOKS
A BIT LOW ATTM... BUT NOT IMPOSSIBLE IN THE NEXT FEW HOURS ON EDGE
OF LOW LEVEL JET IN FAR ECNTRL SD INTO WCNTRL MN.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 255 PM CDT WED MAY 29 2013
A LEAD SHORTWAVE COMING OFF THE MAIN TROUGH CONTINUES TO LIFT
NORTHEASTWARD THROUGH THE DAKOTAS. THE SHORTWAVE ALONG WITH THE
850MB JET NOSING INTO THE AREA HAS HELPED SET OFF SHOWERS AND A
FEW THUNDERSTORMS OVER MAINLY THE SOUTHERN CWA THIS AFTERNOON.
CLOUDS AND COOLER TEMPS HAVE KEPT INSTABILITY MINIMIZED ACROSS THE
SOUTHERN CWA BUT SPC MESOANALYSIS HAS SOME CAPE AROUND 1000 J/KG JUST
TO THE NORTH ACROSS THE CENTRAL CWA. THE VERY UNSTABLE AIR IS STILL
WELL TO OUR SOUTH OVER SD. MODELS HAVE THE CAPE INCREASING OVER OUR
SOUTHERN CWA LATER THIS EVENING...BUT BULK SHEAR IS STILL ONLY
AROUND 20 KTS. THINK THAT THERE WILL BE THE POSSIBILITY OF SOME
SEVERE HAIL OR WINDS...BUT BETTER CHANCES WILL BE FURTHER SOUTH OR
TOMORROW.
THE SHORTWAVE WILL CONTINUE TO LIFT NORTHEASTWARD OVERNIGHT AND
SPREAD RAINFALL TOWARDS THE CANADIAN BORDER. THE TROUGH ENTERING
THE CENTRAL PLAINS TONIGHT WILL CLOSE OFF AND CONTINUE
NORTHEASTWARD INTO THE WY/MT AREA AND WESTERN DAKOTAS BY TOMORROW.
THE SFC LOW WILL CONTINUE TO DEEPEN AND LIFT INTO SOUTHERN
ND...WITH A WARM FRONT PUSHING INTO THE CWA. HOW MUCH WE
DESTABILIZE WILL DEPEND ON HOW MUCH CLEARING OCCURS TOMORROW
AFTERNOON. THE NAM HAS AROUND 1300 J/KG IN SOME AREAS BUT LIKE
TODAY HAS SOME PLACES WITH REDUCED INSTABILITY DUE TO CLOUDS AND
PRECIP. THE GFS HAS A MORE WIDESPREAD AREA OF MORE THAN 1500 J/KG.
BOTH MODELS HAVE MORE SIGNIFICANT SHEAR AND WITH THE SFC BOUNDARY
IN THE AREA THINK THAT THERE WILL BE A GOOD CHANCE FOR SEVERE
STORMS TOMORROW AFTERNOON AND EVENING.
THE UPPER LOW WILL CONTINUE OVER THE DAKOTAS THURSDAY NIGHT...WITH
THE BULK OF THE PRECIP MOVING INTO THE NORTHERN CWA DURING THE
OVERNIGHT HOURS AS THE WARM FRONT MOVES TOWARDS THE CANADIAN
BORDER.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 255 PM CDT WED MAY 29 2013
FRIDAY...THE MODELS SEEM TO BE IN FAIRLY DECENT AGREEMENT ON THE
DRY SLOT MOVING INTO THE SOUTHERN COUNTIES. LOWERED POPS A BIT IN
THAT AREA. THE UPPER LOW WILL FINALLY BEGIN TO MOVE EASTWARD
FRIDAY AND FRIDAY NIGHT. THIS WILL HELP PUSH THE SFC LOW INTO MN
AND DROP A COLD FRONT INTO THE CWA. THE FRONT WILL BE THROUGH THE
WESTERN CWA BY FRIDAY AFTERNOON AND ACROSS THE ENTIRE AREA FRIDAY
NIGHT. INCREASED POPS AGAIN IN THE SOUTH AS THE COLD FRONT MOVES
IN. TEMPS SHOULD DROP DOWN INTO THE 60S FOR HIGHS AND 40S TO LOW
50S FOR LOWS.
EARLY IN THE PERIOD...SHORT WAVES WILL CONTINUE TO ROTATE AROUND
UPPER LOW PROGGED TO BE OVER UPPER GREAT LAKES. THIS WILL CONTINUE
CHANCES FOR RAIN SHOWERS THROUGH THE DAY SATURDAY. MODELS IN GENERAL
AGREEMENT HOWEVER GFS PUTS ASSOCIATED SFC LOW FURTHER EAST. SHORT
WAVE RIDGE THEN SETS UP FOR SUNDAY AND SHOULD SEE DRY WEATHER BEFORE
NEXT ROUND OF SHOWERS/TSTMS MOVES IN AS AN UPPER LOW TRANSITS
SOUTHERN SASK/MANITOBA. STILL SOME DIFFERENCES IN POSITION OF UPPER
LOW (ECMWF FURTHER NORTH) HOWEVER SIMILAR SOLUTIONS FOR PLACEMENT OF
PRECIP ACROSS OUR CWA MON NIGHT INTO TUE. CONSALL SOLUTION TRENDING
TOWARD LIKELY POPS...WHICH SEEMS REASONABLE ALTHOUGH LIKELY TO
WIDESPREAD THIS FAR OUT. AN ACTIVE PERIOD FOR NEXT WEEK NONETHELESS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 716 PM CDT WED MAY 29 2013
GNERAL IDEA FROM HRRR IS TO BRING UP OR DEVELOP MVFR CLOUD COVER
INTO THE FCST AREA OVERNIGHT INTO THURSDAY MORNING AS DEW PTS ARE
IN THE UPPER 50S TO LOWER 60S. SOME HIGHER DEW PTS IN SD AND
WCNTRL MN WITH A FEW SPOTS NR 70 MAY MOVE NORTH AS WELL. IN THESE
SITUATIONS HAVE OFTEN SEEN LOW LEVEL CLOUD COVER SPREADING OR
DEVELOPING NORTH LATE NIGHT INTO THE MORNING. KEPT SHOWERS IN
FARGO-BEMIDJI THIS EVE THEN BROUGHT MORE PREDOMINATE SHOWERS GFK-
DVL-TVF MOSTLY AFTER 06Z INTO THU MID MORNING. BUT TIMING OF
PRECIP UNCERTAIN.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...JR
LONG TERM...JR/SPEICHER
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS BISMARCK ND
720 PM CDT WED MAY 29 2013
.UPDATE...
ISSUED AT 720 PM CDT WED MAY 29 2013
THE BIGGEST CHANGE WITH THIS UPDATE WAS TO REDUCE POPS...ESPECIALLY
ALONG AND NORTH OF US HIGHWAY 2...GIVEN THE LATEST RADAR TRENDS
AND THE 21 UTC HRRR SIMULATED REFLECTIVITY WHICH HAS MAINTAINED
CONTINUITY WITH PREVIOUS RUNS WHICH KEEP MUCH OF NORTHERN NORTH DAKOTA
PRECIPITATION FREE THROUGH AT LEAST 06 UTC. GIVEN THE MARGINAL
INSTABILITY AND SHEAR...THE SMALL WINDOW FOR SEVERE HAIL AND/OR
WINDS ACROSS THE JAMES RIVER VALLEY APPEARS TO BE QUICKLY CLOSING
AND WILL FOCUS ON HEAVY RAIN MONITORING OVER THE SATURATED AREAS
OF SOUTHERN NORTH DAKOTA.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 405 PM CDT WED MAY 29 2013
MAIN PROBLEM IN THE SHORT TERM PERIOD WILL BE PRECIPITATION
AMOUNTS...PLACEMENT AND TIMING.
CURRENTLY...SURFACE LOW PRESSURE OVER THE CENTRAL PLAINS WITH A
WARM FRONT EXTENDING INTO EASTERN SOUTH DAKOTA AND SOUTHERN
MINNESOTA. STRONG NEGATIVELY TILTED UPPER LEVEL TROUGH FROM THE
NORTHWEST U.S. INTO THE CENTRAL ROCKIES. CURRENT CONVECTION IN OUR
AREA IS LINING UP WITH THE THE STRONG WARM ADVECTION OVER THE
EASTERN DAKOTAS INTO MINNESOTA...AS WELL AS STRONG UPPER LEVEL
DIVERGENCE OVER EASTERN MONTANA.
TONIGHT...THE UPPER LEVEL WAVE WILL LIFT NORTHWARD INTO THE
NORTHERN HIGH PLAINS WITH THE SURFACE LOW TRACKING NORTH THROUGH
SOUTH DAKOTA. THIS WILL BRING INCREASING SHOWERS AND POSSIBLY SOME
THUNDERSTORMS TO WESTERN AND CENTRAL NORTH DAKOTA. ALTHOUGH WE DO
THINK MOST AREAS WILL RECEIVE PRECIPITATION...WE HAVE CONTINUED
THE TREND OF DELAYING THE ONSET...AND CUTTING BACK A LITTLE ON THE
AMOUNTS. AGAIN..WE ARE IN A BIT OF A LULL BETWEEN THE STRONG WARM
ADVECTION TO OUR EAST...AND THE STRONG FORCING AND DIVERGENT FLOW
ALOFT ASSOCIATED WITH THE UPPER LEVEL SYSTEM TO OUR WEST.
THURSDAY...THE UPPER LEVEL LOW CONTINUES TO LIFT NORTH THROUGH
EASTERN MONTANA...WHILE THE SURFACE LOW LIFTS NORTH TO NEAR
BISMARCK...THEN NORTHWEST TOWARDS WILLISTON. THIS PLACEMENT WOULD
BRING GREATEST PRECIPITATION AMOUNTS TO THE NORTHERN HALF OF THE
CWA...WITH DRIER AIR WORKING FROM SOUTH TO NORTH THURSDAY
AFTERNOON. THIS WOULD BRING AN END TO PRECIPITATION ACROSS THE
SOUTH HALF OF THE CWA...BUT COULD ALSO ALLOW FOR A PERIOD OF
DESTABILIZATION THURSDAY AFTERNOON IN THE DRIER AIR. WITH THE
SURFACE AND UPPER LOWS JUST WEST...THIS WOULD INCREASE THE RISK OF
THUNDERSTORMS IN A HIGH SHEAR ENVIRONMENT. DUE TO SOME MODEL AND
TIMING UNCERTAINTIES WILL NOT MENTION SEVERE AT THIS TIME...AND
LET LATER SHIFTS UPDATE AS NEEDED.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 405 PM CDT WED MAY 29 2013
WET AND COOL WEATHER REMAINS OVER THE NORTHERN PLAINS THROUGH EARLY
SATURDAY...FOLLOWED BY QUIET CONDITIONS SATURDAY THROUGH SUNDAY
AFTERNOON...THEN A RETURN TO ACTIVE CONDITIONS SUNDAY NIGHT THROUGH
TUESDAY.
THE LONG TERM BEGINS THURSDAY EVENING WITH A CLOSED UPPER LEVEL LOW
CENTERED OVER SOUTHWEST ND/SOUTHEASTERN MONTANA...AND AN AREA OF
SURFACE LOW PRESSURE OVER WESTERN NORTH DAKOTA. ACTIVE WEATHER WILL
BE ONGOING AT THE START OF THE PERIOD WITH WIDESPREAD RAIN SHOWERS
AND ISOLATED THUNDERSTORMS ACROSS THE NORTH AND FAR WEST WRAPPING
AROUND THE UPPER LOW. OVER SOUTH CENTRAL AND SOUTHEASTERN NORTH
DAKOTA...A DRY SLOT IS EXPECTED TO PROVIDE SOME CLEARING THURSDAY
AFTERNOON INTO THURSDAY EVENING...WITH THE RESULTANT HEATING ACTING
TO INCREASE SURFACE INSTABILITY WITH UPWARDS TO NEAR 1500 J/KG OF
CAPE FORECAST NEAR A SFC COLD/OCCLUDED FRONT. MAY SEE ISOLATED
SEVERE STORMS DEVELOP GIVEN THE ADVERTISED INSTABILITY PERSISTING
INTO THE EVENING NEAR THE BOUNDARY.
LOW LINGERS ACROSS THE NORTHERN PLAINS THROUGH FRIDAY BEFORE
MORPHING INTO AN OPEN WAVE AND PUSHING OFF TO OUR EAST SATURDAY
AFTERNOON. AS THIS OCCURS...WILL SEE WRAP AROUND PRECIPITATION
SPREAD FROM WEST TO EAST FRIDAY MORNING THROUGH FRIDAY
EVENING...THEN DECREASING CLOUDS AND CHANCES FOR RAIN FROM
NORTHWEST TO SOUTHEAST FRIDAY NIGHT INTO SATURDAY. OVERALL EXPECT
UPWARDS TO AN ADDITIONAL ONE HALF INCH OF RAINFALL THURSDAY NIGHT
THROUGH SATURDAY MORNING ACROSS WEST AND CENTRAL ND.
DRY WEATHER REMAINS IN THE FORECAST SATURDAY NIGHT THROUGH SUNDAY
AFTERNOON WITH A SHORT WAVE RIDGE AND SURFACE HIGH PRESSURE BUILDING
EAST ACROSS THE NORTHERN PLAINS. ACTIVE WEATHER RESUMES SUNDAY NIGHT
INTO EARLY NEXT WEEK AS ANOTHER UPPER LOW/TROUGH PUSHES ACROSS THE
NORTHERN ROCKIES AND EVENTUALLY INTO THE NORTHERN PLAINS.
WELL BELOW NORMAL TEMPERATURES FRIDAY AND SATURDAY WITH HIGHS 55-65
AND LOWS IN THE UPPER 30S TO MID 40S. WILL NEED TO MONITOR FOR
POSSIBLE FROST SATURDAY NIGHT/SUNDAY MORNING WHEN WINDS ARE EXPECTED
TO BE LIGHT...SKIES CLEAR...AND SFC DEWPOINT TEMPS FORECAST TO FALL
AS LOW AS 35F DEGREES SOME AREAS. DAYTIME AND NIGHTTIME TEMPERATURES
MODERATE TOWARDS NORMAL SUNDAY-TUESDAY WITH HIGHS GENERALLY IN THE
60S AND LOW 45-55.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY)
ISSUED AT 720 PM CDT WED MAY 29 2013
SCATTERED SHOWERS AND THUNDERSTORMS IN THE KDIK AND KJMS
VICINITIES WILL INCREASE IN COVERAGE ACROSS WESTERN AND CENTRAL
NORTH DAKOTA THROUGH THE NIGHT...WITH FLIGHT CONDITIONS TRENDING
TOWARDS IFR AT KDIK...KMOT AND KISN IN MODERATE RAIN LATE
TONIGHT...AND MVFR AT KBIS AND KJMS. DEPENDING ON HOW MUCH
CLEARING THERE IS THURSDAY AFTERNOON...STRONG TO SEVERE
THUNDERSTORMS MAY BE POSSIBLE FOR THE KDIK...KBIS AND KJMS TAF
SITES THURSDAY AFTERNOON AND EVENING.
&&
.HYDROLOGY...
ISSUED AT 405 PM CDT WED MAY 29 2013
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP LATE THIS
AFTERNOON AND TONIGHT...AND MOVE FROM SOUTH TO NORTH ACROSS
WESTERN AND CENTRAL NORTH DAKOTA THROUGH THURSDAY AFTERNOON.
THE POTENTIAL FOR HEAVY RAIN EXISTS ACROSS THE WEST AND CENTRAL...
ESPECIALLY LATE TONIGHT THROUGH THURSDAY. WIDESPREAD RAINFALL
AMOUNTS OF THREE QUARTERS OF AN INCH...TO TWO INCHES ARE FORECAST
THOUGH THIS PERIOD. HOWEVER...THE LATEST GUIDANCE CONTINUES TO
SUGGEST A LESS LIKELY SCENARIO FOR AMOUNTS GREATER THAN 1.5 INCHES
OVER MUCH OF THE CENTRAL. THE MOST LIKELY AREAS FOR THE HIGHEST
AMOUNTS APPEAR TO BE IN THE FAR NORTH AND FAR WEST...WITH THE
HIGHEST AMOUNTS IN EASTERN MONTANA AND SOUTHERN CANADA.
STREAM AND RIVER RISES ARE POSSIBLE BY THE END OF THE WEEK INTO
THIS COMING WEEKEND. AN ADDITIONAL ONE QUARTER TO ONE HALF INCH
WILL BE POSSIBLE FRIDAY AND FRIDAY NIGHT. CHANCES FOR RAIN
DECREASE SATURDAY INTO SATURDAY NIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...TWH
LONG TERM...NH
AVIATION...TWH
HYDROLOGY...TWH
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
110 PM CDT TUE MAY 28 2013
.UPDATE...
ISSUED AT 110 PM CDT TUE MAY 28 2013
BAND OF LIGHT RAIN SHOWERS HAS MOVED INTO NORTHWEST MN AND WILL
SHIFT HIGHER CHANCE POPS INTO THIS REGION FOR THE REST OF THE
AFTERNOON. ALONG AND WEST OF THE VALLEY...DID ADD SOME 30 POPS
WITHIN THE BROADER AREA OF 20S. CLOUDS HAVE BECOME SCATTERED-
BROKEN WEST OF A LINE FROM LANGDON TO VALLEY CITY AND THINK
SURFACE HEATING AND CYCLONIC FLOW ALOFT SHOULD RESULT IN
ADDITIONAL SHOWER DEVELOPMENT LATE AFTERNOON. KEPT THESE 20-30
POPS INTO THE EARLY EVENING ACROSS THE DEVILS LAKE BASIN...BUT
THINK ALL ACTIVITY SHOULD FALL APART BY 03 UTC. ALSO ADDED
ISOLATED THUNDER TO WEATHER GRIDS HAVING OBSERVED A COUPLE
LIGHTNING STRIKES NORTH OF THE BORDER.
WITH THICK CLOUD COVER TAKING MORE TIME TO PUSH EAST/DISSIPATE...
LOWERED TEMPERATURES ACROSS THE FORECAST AREA ANOTHER 2 TO 4
DEGREES. AREAS THAT REACH THE LOW 70S WILL BE ACROSS EASTERN ND
WITH MOST OF NORTHWEST AND WEST CENTRAL MN STAYING IN THE 60S.
UPDATE ISSUED AT 1004 AM CDT TUE MAY 28 2013
15 UTC REGIONAL RADAR SHOWS A NARROW BAND OF LIGHT SHOWERS ACROSS
NORTHEAST ND...MOVING INTO CANADA AROUND 20 MPH. ANY ADDITIONAL
ISOLATED TO SCATTERED SHOWERS THROUGH THE DAY WILL BE CONFINED
MAINLY TO EASTERN ND AS DEPICTED BY THE LATEST SUITE OF MODELS.
SHOULD SEE SOME BREAKS IN THE CLOUDS ALONG AND WEST OF THE VALLEY
LATE THIS MORNING AND THROUGH THE AFTERNOON...BUT OVERCAST SKIES
EXPECTED TO PERSIST ACROSS MUCH OF NORTHWEST AND WEST CENTRAL MN
THROUGH THE DAY. AS A RESULT...DID DROP TEMPERATURES A FEW DEGREES
ACROSS WEST CENTRAL MN WITH HIGHS IN THE MID TO UPPER 60S. ALL
OTHER AREAS SHOULD SEE ENOUGH SUN TO CLIMB INTO THE LOWER 70S.
MODEST SOUTHERLY WIND WILL GRADUALLY WEAKEN AND SHIFT TO THE WEST
THIS EVENING AND OVERNIGHT AS THE MAIN SURFACE TROUGH MOVES ACROSS
THE REGION. OVERALL...FORECAST IS IN GOOD SHAPE WITH NO MAJOR
CHANGES AT THIS TIME.
UPDATE ISSUED AT 638 AM CDT TUE MAY 28 2013
SHORTWAVE TROUGH IS SWINGING THROUGH THE FA AND ASSOCIATED FORCING
IS CAUSING SHOWERS TO DEVELOP WITHIN THE DEVILS LAKE BASIN. EXPECT
THIS ACTIVITY TO PROPAGATE TO THE NORTHEAST ALONG WITH THE UPPER
WAVE. INCREASED POPS TO HIGH CHANCE CATEGORY FOR THIS ACTIVITY.
STILL EXPECT SOME CLEARING ACROSS THE WESTERN FA BY THIS AFTERNOON.
THIS SHOULD ALLOW ENOUGH HEATING TO COMBINE WITH UPPER JET STREAK
FOR ISOLATED SHOWERS...WHICH THE HRRR CONTINUES TO INDICATE.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 347 AM CDT TUE MAY 28 2013
THERE ARE A COUPLE UPPER LEVEL SHORTWAVES ACROSS EASTERN AND
NORTHERN NORTH DAKOTA THAT WILL CONTINUE TO PROPAGATE TO THE
NORTHEAST TODAY. WILL KEEP THE ISOLD-SCATTERED SHOWERS THROUGH THE
MORNING HOURS ACROSS THE NE FA. HRRR/RAP/4-KM WRF MODELS INDICATE
THE POTENTIAL FOR ISOLD SHOWERS ALONG AND WEST OF THE VALLEY THIS
AFTERNOON AS HEATING COMBINES WITH AN UPPER LEVEL JET STREAK.
OTHERWISE...THIS PERIOD WILL BE MOSTLY DRY AS RIDGING AFFECTS THE
AREA TONIGHT INTO TUESDAY AND MUCH OF WEDNESDAY. THUNDER CHANCES
INCREASE BY LATER WEDNESDAY AFTERNOON ACROSS THE SOUTHERN FA.
TEMPERATURES SHOULD BE NEAR NORMAL VALUES AS CLOUD COVER IS
EXPECTED TO BE MORE SCATTERED THAN THE PAST COUPLE DAYS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 347 AM CDT TUE MAY 28 2013
WEDNESDAY NIGHT-THURSDAY NIGHT...
SEVERE POTENTIAL AND HEAVY RAIN POTENTIAL WILL BE THE MAIN
CONCERNS. ALTHOUGH MODELS HAVE HAVE A SIMILAR IDEA...THERE ARE
DIFFERENCES WITH THE LEAD SHORTWAVE AND POTENTIAL IMPACTS
WEDNESDAY EVENING INTO THURSDAY MORNING. ECMWF IS THE PREFERRED
MODEL AS PER THE PMDHMD. FOR WED NIGHT...THERE WILL LIKELY BE A
SURGE OF INSTABILITY AS AN ELEVATED WARM FRONT PROPAGATES NORTHWARD
THROUGH THE FA. SEVERE POTENTIAL WILL DEPEND ON THE STRENGTH OF
THE LOW LEVEL JET...THE ECMWF IS AROUND 40 KNOTS. DEEP LAYER SHEAR
AND INSTABILITY WILL BE MARGINAL...AND CAN IMAGINE A FEW SEVERE
STORMS...BUT NOT AN OUTBREAK SCENARIO. SHOWER AND THUNDERSTORM
CHANCES CONTINUE INTO THURSDAY AS THE REGION REMAINS IN WARM AIR
ADVECTION REGIME. THESE CHANCES END FROM WEST TO EAST THURSDAY
AFTERNOON AND EVENING AS A COLD FRONT AND STABLE AIRMASS MOVE
INTO THE REGION. IT IS BECOMING MORE LIKELY THAT THE UPPER LOW
WILL CLOSE OFF WITHIN NORTH DAKOTA...WITH THE BOUNDARY STALLING
NORTH OF THE INTERNATIONAL BORDER. THE MAIN HEAVY RAIN THREAT WILL
BE WHERE EVER THIS BOUNDARY STALLS. HOWEVER...PWATS WILL INCREASE
TO AROUND 1.5 INCHES WED NIGHT...AND THE POTENTIAL WILL EXIST FOR
ISOLATED HEAVY RAINFALL. THIS POTENTIAL WILL BE GREATEST WHERE LOW
LEVEL CONVERGENCE IS MAXIMIZED (NOSE OF LOW LEVEL JET)...AND WILL
MENTION LOCALLY HEAVY RAINFALL POSSIBLE FOR AREAS WEST OF THE
VALLEY.
FRIDAY-MONDAY...
MODELS IN GOOD AGREEMENT WITH PLACEMENT AND EVOLUTION OF 500MB
CLOSED LOW AT 12 FRI CENTERED OVER THE WESTERN THIRD OF ND. THE
HIGHEST UNCERTAINTY LIES WITHIN THE POSITION OF THE WARM FRONT AND
WHERE IT STALLS. THE 00Z ECMWF AND GEM CONTINUE TO STALL IT NORTH OF
THE CWFA WHEREAS THE GFS STALLS IT ACROSS THE NORTHERN PORTIONS OF
THE FA. IF THE GFS IS RIGHT MUCH HIGHER AMOUNTS OF QPF ARE POSSIBLE.
THE DRIER SOLNS WOULD BRING THE DRY SLOT ACROSS THE CWFA ON
FRIDAY. ALL SOLNS BRING DEFORMATION RAIN BANDS THROUGH THE AREA ON
SATURDAY...GFS FASTER TO EXIT SAT AFTERNOON.
SUNDAY AND MONDAY 500MB RIDGING AND SFC HIGH PRESSURE WILL GIVE
QUITE WEATHER TO THE AREA WITH SEASONAL TEMPERATURES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 110 PM CDT TUE MAY 28 2013
CIGS/VSBY A CHALLENGE AS AN AREA OF LOW PRESSURE IS SITUATED IN NC
NORTH DAKOTA WITH AN ATTENDANT TROF EXTENDING SOUTH NEAR JMS.
OBSERVATIONS SHOW MAINLY MVFR/IFR CIGS OVER THE AREA...BUT VIS
SATELLITE SHOWS MORE CELLULAR DEVELOPMENT AND SCATTERING SKIES WITH
INCREASED HEATING. EXPECT SCATTERING OF CLOUDS TO CONTINUE ALONG
WITH INCREASING CLOUD/CIG HEIGHTS INTO THE AFTERNOON AND REFLECTED
SAME IN THE TAFS. A BIT OF DRYING CAN BE EXPECTED IN THE LOWER
LEVELS AS INDICATED BY FORECAST SOUNDINGS AND LOOK FOR THAT TO
EXPAND EAST ACROSS ND INTO MN THRU THE AFTERNOON AND EVENING HOURS.
OTHERWISE...EXPECT CIGS TO REMAIN OVERNIGHT THRU THE REST OF THE
PERIOD...BUT LOOKING FOR MAINLY VFR CONDITIONS WITH POCKETS OF MVFR
CIGS.
&&
.HYDROLOGY...
ISSUED AT 110 PM CDT TUE MAY 28 2013
THE AREAL FLOOD WARNING FOR PEMBINA...WALSH...AND EASTERN CAVALIER
COUNTIES HAS BEEN CANCELLED. ALTHOUGH THE GROUND REMAINS SATURATED
AND MANY AREA RIVERS AND STREAMS REMAIN HIGH...OVERLAND FLOOD
CONCERNS HAVE DIMINISHED SIGNIFICANTLY OVER THE PAST FEW DAYS.
OTHERWISE...MOST RIVERS OVER THE REGION HAVE CONTINUED TO GRADUALLY
RECEDE OR ARE HOLDING NEARLY STEADY...WITH NO FORECAST POINTS
CURRENTLY ABOVE FLOOD STAGE.
THE POTENTIAL EXISTS FOR LOCALLY HEAVY RAINFALL WEDNESDAY EVENING
INTO EARLY THURSDAY MORNING...MAINLY ACROSS EASTERN NORTH DAKOTA.
THE MOST PROBABLE SCENARIO GIVES WIDESPREAD RAINFALL OF 0.50 TO
1.50 INCHES DURING THIS PERIOD. THESE AMOUNTS WOULD HAVE MINIMAL
IMPACTS. HOWEVER...ISOLATED AMOUNTS OF 2 OR MORE INCHES ARE
POSSIBLE...AND COULD HAVE IMPACTS DEPENDING ON HOW MUCH AND WHERE
IT FALLS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...ROGERS
SHORT TERM...TG
LONG TERM...TG/JK
AVIATION...HOPKINS
HYDROLOGY...MAKOWSKI
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
1004 AM CDT TUE MAY 28 2013
.UPDATE...
ISSUED AT 1004 AM CDT TUE MAY 28 2013
15 UTC REGIONAL RADAR SHOWS A NARROW BAND OF LIGHT SHOWERS ACROSS
NORTHEAST ND...MOVING INTO CANADA AROUND 20 MPH. ANY ADDITIONAL
ISOLATED TO SCATTERED SHOWERS THROUGH THE DAY WILL BE CONFINED
MAINLY TO EASTERN ND AS DEPICTED BY THE LATEST SUITE OF MODELS.
SHOULD SEE SOME BREAKS IN THE CLOUDS ALONG AND WEST OF THE VALLEY
LATE THIS MORNING AND THROUGH THE AFTERNOON...BUT OVERCAST SKIES
EXPECTED TO PERSIST ACROSS MUCH OF NORTHWEST AND WEST CENTRAL MN
THROUGH THE DAY. AS A RESULT...DID DROP TEMPERATURES A FEW DEGREES
ACROSS WEST CENTRAL MN WITH HIGHS IN THE MID TO UPPER 60S. ALL
OTHER AREAS SHOULD SEE ENOUGH SUN TO CLIMB INTO THE LOWER 70S.
MODEST SOUTHERLY WIND WILL GRADUALLY WEAKEN AND SHIFT TO THE WEST
THIS EVENING AND OVERNIGHT AS THE MAIN SURFACE TROUGH MOVES ACROSS
THE REGION. OVERALL...FORECAST IS IN GOOD SHAPE WITH NO MAJOR
CHANGES AT THIS TIME.
UPDATE ISSUED AT 638 AM CDT TUE MAY 28 2013
SHORTWAVE TROUGH IS SWINGING THROUGH THE FA AND ASSOCIATED FORCING
IS CAUSING SHOWERS TO DEVELOP WITHIN THE DEVILS LAKE BASIN. EXPECT
THIS ACTIVITY TO PROPAGATE TO THE NORTHEAST ALONG WITH THE UPPER
WAVE. INCREASED POPS TO HIGH CHANCE CATEGORY FOR THIS ACTIVITY.
STILL EXPECT SOME CLEARING ACROSS THE WESTERN FA BY THIS AFTERNOON.
THIS SHOULD ALLOW ENOUGH HEATING TO COMBINE WITH UPPER JET STREAK
FOR ISOLATED SHOWERS...WHICH THE HRRR CONTINUES TO INDICATE.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 347 AM CDT TUE MAY 28 2013
THERE ARE A COUPLE UPPER LEVEL SHORTWAVES ACROSS EASTERN AND
NORTHERN NORTH DAKOTA THAT WILL CONTINUE TO PROPAGATE TO THE
NORTHEAST TODAY. WILL KEEP THE ISOLD-SCATTERED SHOWERS THROUGH THE
MORNING HOURS ACROSS THE NE FA. HRRR/RAP/4-KM WRF MODELS INDICATE
THE POTENTIAL FOR ISOLD SHOWERS ALONG AND WEST OF THE VALLEY THIS
AFTERNOON AS HEATING COMBINES WITH AN UPPER LEVEL JET STREAK.
OTHERWISE...THIS PERIOD WILL BE MOSTLY DRY AS RIDGING AFFECTS THE
AREA TONIGHT INTO TUESDAY AND MUCH OF WEDNESDAY. THUNDER CHANCES
INCREASE BY LATER WEDNESDAY AFTERNOON ACROSS THE SOUTHERN FA.
TEMPERATURES SHOULD BE NEAR NORMAL VALUES AS CLOUD COVER IS
EXPECTED TO BE MORE SCATTERED THAN THE PAST COUPLE DAYS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 347 AM CDT TUE MAY 28 2013
WEDNESDAY NIGHT-THURSDAY NIGHT...
SEVERE POTENTIAL AND HEAVY RAIN POTENTIAL WILL BE THE MAIN
CONCERNS. ALTHOUGH MODELS HAVE HAVE A SIMILAR IDEA...THERE ARE
DIFFERENCES WITH THE LEAD SHORTWAVE AND POTENTIAL IMPACTS
WEDNESDAY EVENING INTO THURSDAY MORNING. ECMWF IS THE PREFERRED
MODEL AS PER THE PMDHMD. FOR WED NIGHT...THERE WILL LIKELY BE A
SURGE OF INSTABILITY AS AN ELEVATED WARM FRONT PROPAGATES NORTHWARD
THROUGH THE FA. SEVERE POTENTIAL WILL DEPEND ON THE STRENGTH OF
THE LOW LEVEL JET...THE ECMWF IS AROUND 40 KNOTS. DEEP LAYER SHEAR
AND INSTABILITY WILL BE MARGINAL...AND CAN IMAGINE A FEW SEVERE
STORMS...BUT NOT AN OUTBREAK SCENARIO. SHOWER AND THUNDERSTORM
CHANCES CONTINUE INTO THURSDAY AS THE REGION REMAINS IN WARM AIR
ADVECTION REGIME. THESE CHANCES END FROM WEST TO EAST THURSDAY
AFTERNOON AND EVENING AS A COLD FRONT AND STABLE AIRMASS MOVE
INTO THE REGION. IT IS BECOMING MORE LIKELY THAT THE UPPER LOW
WILL CLOSE OFF WITHIN NORTH DAKOTA...WITH THE BOUNDARY STALLING
NORTH OF THE INTERNATIONAL BORDER. THE MAIN HEAVY RAIN THREAT WILL
BE WHERE EVER THIS BOUNDARY STALLS. HOWEVER...PWATS WILL INCREASE
TO AROUND 1.5 INCHES WED NIGHT...AND THE POTENTIAL WILL EXIST FOR
ISOLATED HEAVY RAINFALL. THIS POTENTIAL WILL BE GREATEST WHERE LOW
LEVEL CONVERGENCE IS MAXIMIZED (NOSE OF LOW LEVEL JET)...AND WILL
MENTION LOCALLY HEAVY RAINFALL POSSIBLE FOR AREAS WEST OF THE
VALLEY.
FRIDAY-MONDAY...
MODELS IN GOOD AGREEMENT WITH PLACEMENT AND EVOLUTION OF 500MB
CLOSED LOW AT 12 FRI CENTERED OVER THE WESTERN THIRD OF ND. THE
HIGHEST UNCERTAINTY LIES WITHIN THE POSITION OF THE WARM FRONT AND
WHERE IT STALLS. THE 00Z ECMWF AND GEM CONTINUE TO STALL IT NORTH OF
THE CWFA WHEREAS THE GFS STALLS IT ACROSS THE NORTHERN PORTIONS OF
THE FA. IF THE GFS IS RIGHT MUCH HIGHER AMOUNTS OF QPF ARE POSSIBLE.
THE DRIER SOLNS WOULD BRING THE DRY SLOT ACROSS THE CWFA ON
FRIDAY. ALL SOLNS BRING DEFORMATION RAIN BANDS THROUGH THE AREA ON
SATURDAY...GFS FASTER TO EXIT SAT AFTERNOON.
SUNDAY AND MONDAY 500MB RIDGING AND SFC HIGH PRESSURE WILL GIVE
QUITE WEATHER TO THE AREA WITH SEASONAL TEMPERATURES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 638 AM CDT TUE MAY 28 2013
BAND OF IFR/MVFR CIGS WILL REMAIN THROUGH MUCH OF THE MORNING
HOURS AND GRADUALLY SCATTER AND/OR CLEAR FROM THE WEST FOR THE
AFTERNOON HOURS.
&&
.HYDROLOGY...
ISSUED AT 347 AM CDT TUE MAY 28 2013
AN AREAL FLOOD WARNING REMAINS IN EFFECT FOR PEMBINA...WALSH...
AND EASTERN CAVALIER COUNTIES THROUGH TODAY.
THE POTENTIAL EXISTS FOR LOCALLY HEAVY RAINFALL WEDNESDAY EVENING
INTO EARLY THURSDAY MORNING...MAINLY ACROSS EASTERN NORTH DAKOTA.
THE MOST PROBABLE SCENARIO GIVES WIDESPREAD RAINFALL OF 0.50 TO
1.50 INCHES DURING THIS PERIOD. THESE AMOUNTS WOULD HAVE MINIMAL
IMPACTS. HOWEVER...ISOLATED AMOUNTS OF 2 OR MORE INCHES ARE
POSSIBLE...AND COULD HAVE IMPACTS DEPENDING ON HOW MUCH AND WHERE
IT FALLS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...ROGERS
SHORT TERM...TG
LONG TERM...TG/JK
AVIATION...TG
HYDROLOGY...MAKOWSKI/TG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
638 AM CDT TUE MAY 28 2013
.UPDATE...
ISSUED AT 638 AM CDT TUE MAY 28 2013
SHORTWAVE TROUGH IS SWINGING THROUGH THE FA AND ASSOCIATED FORCING
IS CAUSING SHOWERS TO DEVELOP WITHIN THE DEVILS LAKE BASIN. EXPECT
THIS ACTIVITY TO PROPAGATE TO THE NORTHEAST ALONG WITH THE UPPER
WAVE. INCREASED POPS TO HIGH CHANCE CATEGORY FOR THIS ACTIVITY.
STILL EXPECT SOME CLEARING ACROSS THE WESTERN FA BY THIS AFTERNOON.
THIS SHOULD ALLOW ENOUGH HEATING TO COMBINE WITH UPPER JET STREAK
FOR ISOLATED SHOWERS...WHICH THE HRRR CONTINUES TO INDICATE.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 347 AM CDT TUE MAY 28 2013
THERE ARE A COUPLE UPPER LEVEL SHORTWAVES ACROSS EASTERN AND
NORTHERN NORTH DAKOTA THAT WILL CONTINUE TO PROPAGATE TO THE
NORTHEAST TODAY. WILL KEEP THE ISOLD-SCATTERED SHOWERS THROUGH THE
MORNING HOURS ACROSS THE NE FA. HRRR/RAP/4-KM WRF MODELS INDICATE
THE POTENTIAL FOR ISOLD SHOWERS ALONG AND WEST OF THE VALLEY THIS
AFTERNOON AS HEATING COMBINES WITH AN UPPER LEVEL JET STREAK.
OTHERWISE...THIS PERIOD WILL BE MOSTLY DRY AS RIDGING AFFECTS THE
AREA TONIGHT INTO TUESDAY AND MUCH OF WEDNESDAY. THUNDER CHANCES
INCREASE BY LATER WEDNESDAY AFTERNOON ACROSS THE SOUTHERN FA.
TEMPERATURES SHOULD BE NEAR NORMAL VALUES AS CLOUD COVER IS
EXPECTED TO BE MORE SCATTERED THAN THE PAST COUPLE DAYS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 347 AM CDT TUE MAY 28 2013
WEDNESDAY NIGHT-THURSDAY NIGHT...
SEVERE POTENTIAL AND HEAVY RAIN POTENTIAL WILL BE THE MAIN
CONCERNS. ALTHOUGH MODELS HAVE HAVE A SIMILAR IDEA...THERE ARE
DIFFERENCES WITH THE LEAD SHORTWAVE AND POTENTIAL IMPACTS
WEDNESDAY EVENING INTO THURSDAY MORNING. ECMWF IS THE PREFERRED
MODEL AS PER THE PMDHMD. FOR WED NIGHT...THERE WILL LIKELY BE A
SURGE OF INSTABILITY AS AN ELEVATED WARM FRONT PROPAGATES NORTHWARD
THROUGH THE FA. SEVERE POTENTIAL WILL DEPEND ON THE STRENGTH OF
THE LOW LEVEL JET...THE ECMWF IS AROUND 40 KNOTS. DEEP LAYER SHEAR
AND INSTABILITY WILL BE MARGINAL...AND CAN IMAGINE A FEW SEVERE
STORMS...BUT NOT AN OUTBREAK SCENARIO. SHOWER AND THUNDERSTORM
CHANCES CONTINUE INTO THURSDAY AS THE REGION REMAINS IN WARM AIR
ADVECTION REGIME. THESE CHANCES END FROM WEST TO EAST THURSDAY
AFTERNOON AND EVENING AS A COLD FRONT AND STABLE AIRMASS MOVE
INTO THE REGION. IT IS BECOMING MORE LIKELY THAT THE UPPER LOW
WILL CLOSE OFF WITHIN NORTH DAKOTA...WITH THE BOUNDARY STALLING
NORTH OF THE INTERNATIONAL BORDER. THE MAIN HEAVY RAIN THREAT WILL
BE WHERE EVER THIS BOUNDARY STALLS. HOWEVER...PWATS WILL INCREASE
TO AROUND 1.5 INCHES WED NIGHT...AND THE POTENTIAL WILL EXIST FOR
ISOLATED HEAVY RAINFALL. THIS POTENTIAL WILL BE GREATEST WHERE LOW
LEVEL CONVERGENCE IS MAXIMIZED (NOSE OF LOW LEVEL JET)...AND WILL
MENTION LOCALLY HEAVY RAINFALL POSSIBLE FOR AREAS WEST OF THE
VALLEY.
FRIDAY-MONDAY...
MODELS IN GOOD AGREEMENT WITH PLACEMENT AND EVOLUTION OF 500MB
CLOSED LOW AT 12 FRI CENTERED OVER THE WESTERN THIRD OF ND. THE
HIGHEST UNCERTAINTY LIES WITHIN THE POSITION OF THE WARM FRONT AND
WHERE IT STALLS. THE 00Z ECMWF AND GEM CONTINUE TO STALL IT NORTH OF
THE CWFA WHEREAS THE GFS STALLS IT ACROSS THE NORTHERN PORTIONS OF
THE FA. IF THE GFS IS RIGHT MUCH HIGHER AMOUNTS OF QPF ARE POSSIBLE.
THE DRIER SOLNS WOULD BRING THE DRY SLOT ACROSS THE CWFA ON
FRIDAY. ALL SOLNS BRING DEFORMATION RAIN BANDS THROUGH THE AREA ON
SATURDAY...GFS FASTER TO EXIT SAT AFTERNOON.
SUNDAY AND MONDAY 500MB RIDGING AND SFC HIGH PRESSURE WILL GIVE
QUITE WEATHER TO THE AREA WITH SEASONAL TEMPERATURES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 638 AM CDT TUE MAY 28 2013
BAND OF IFR/MVFR CIGS WILL REMAIN THROUGH MUCH OF THE MORNING
HOURS AND GRADUALLY SCATTER AND/OR CLEAR FROM THE WEST FOR THE
AFTERNOON HOURS.
&&
.HYDROLOGY...
ISSUED AT 347 AM CDT TUE MAY 28 2013
AN AREAL FLOOD WARNING REMAINS IN EFFECT FOR
PEMBINA...WALSH...AND EASTERN CAVALIER COUNTIES THROUGH TODAY.
THE POTENTIAL EXISTS FOR LOCALLY HEAVY RAINFALL WEDNESDAY EVENING
INTO EARLY THURSDAY MORNING...MAINLY ACROSS EASTERN NORTH DAKOTA.
THE MOST PROBABLE SCENARIO GIVES WIDESPREAD RAINFALL OF 0.50 TO
1.50 INCHES DURING THIS PERIOD. THESE AMOUNTS WOULD HAVE MINIMAL
IMPACTS. HOWEVER...ISOLATED AMOUNTS OF 2 OR MORE INCHES ARE
POSSIBLE...AND COULD HAVE IMPACTS DEPENDING ON HOW MUCH AND WHERE
IT FALLS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...TG
LONG TERM...TG/JK
AVIATION...TG
HYDROLOGY...MAKOWSKI/TG
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
704 PM EDT TUE MAY 28 2013
.SYNOPSIS...
A WARM FRONT WILL CONTINUE TO MOVE NORTH OF THE AREA THROUGH TONIGHT.
BY LATE WEDNESDAY THE FRONT WILL HAVE PUSHED WAY NORTH OF THE AREA
AND TEMPERATURES WILL BE WELL ABOVE NORMAL. A COLD FRONT IS
EXPECTED TO MOVE EAST ACROSS THE FORECAST AREA SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THE QUESTION IS STILL HOW MUCH CONVECTION WILL OCCUR THIS EVENING
AND TONIGHT. WE HAVE REACHED THE CONVECTIVE TEMPERATURES. THE
AIRMASS IS UNSTABLE AND MOIST BUT COULD BE MORE UNSTABLE. SOME OF
THE BETTER DYNAMICS ARE TO THE NORTH IN MICHIGAN. WENT MAINLY
CHANCE POPS. ACCORDING TO THE HRRR MODEL AND THE 4KM WRF NMM MODEL
ANOTHER WAVE WILL HIT THE AREA AFTER DARK. ON THE EDGE ABOUT THAT.
WENT ON THE WARM SIDE WITH THE LOWS BECAUSE OF THE MODERATELY HIGH
DEW POINTS. THREAT FOR SEVERE CONTINUES.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY NIGHT/...
WEDNESDAY IS TOUGH...SOME CONVECTION WILL BE IN THE AREA IN THE
MORNING BUT NOT SURE ABOUT THE AFTERNOON. KEPT THE CHANCE GOING.
DRY AND MUGGY WEDNESDAY NIGHT. THE MODELS ARE TRYING TO HINT AT
SOME CONVECTIVE ACTIVITY THURSDAY AFTERNOON. IT MAY JUST BE
ISOLATED SO LEFT IT OUT FOR THE MOMENT. INCLUDED A CHANCE STARTING
FRIDAY INTO FRIDAY NIGHT AS THE AIRMASS BECOMES MORE UNSTABLE.
USED A BLEND OF GUIDANCE FOR THE LOWS.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
MODELS IN REASONABLY GOOD AGREEMENT WITH THE NEXT FRONT MOVING
THROUGH EARLY SUNDAY...AFTER THAT THE MODELS DIVERGE. THE ECMWF
PUSHES THE FRONT SOUTH OF THE AREA BY SUNDAY EVENING TAKING THE RAIN
WITH IT. THE GFS ON THE OTHER HAND STALLS THE FRONT ACROSS THE AREA
AS A SECONDARY WAVE DEVELOPS AND MOVES ACROSS THE AREA SUNDAY NIGHT
INTO MONDAY. FOR NOW WITH SO MUCH UNCERTAINTY LEFT LIKELY POPS
SATURDAY NIGHT INTO SUNDAY WITH JUST LOW CHANCE POPS SUNDAY NIGHT
AND MONDAY. BOTH MODELS PUSH CANADIAN HIGH PRESSURE SOUTH OVER THE
AREA BY TUESDAY SO SHOULD BE DRY AND COOLER.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
WARM AND UNSTABLE AIRMASS SOUTH OF THE WARM FRONT WILL PERSIST THRU
THE TAF PERIOD BUT FOCUS FOR CONVECTIVE DEVELOPMENT LACKING. WIDELY
SCT TSRA WILL BE POSSIBLE...ESPECIALLY THE REST OF THIS EVENING AND
AGAIN WED AFTERNOON. ONLY TAF SITE WITH DECENT THREAT FOR TSRA NEXT
FEW HOURS APPEARS TO BE ERI.
SOME FOG MAY DEVELOP TONIGHT BUT SURFACE WINDS SHOULD TEND TO STAY 8
KNOTS OR MORE SO DON`T THINK FOG WILL BECOME TOO MUCH OF A
PROBLEM...MAYBE SOME LOCAL MVFR AT THE FAVORED INLAND LOCATIONS. SW
SURFACE WINDS WILL LIKELY INCREASE TO BE GUSTING 22 TO 25 KNOTS BY
MIDDAY WED.
.OUTLOOK...NON VFR POSSIBLE ON SATURDAY IN SHOWERS/THUNDERSTORMS.
&&
.MARINE...
A WARM FRONT STRETCHED ACROSS LAKE ERIE WILL PUSH NORTH OF THE LAKE
TONIGHT. CONVECTION LIKELY THIS EVENING INTO THE OVERNIGHT HOURS
SOME OF THE STORMS COULD BE STRONG TO SEVERE. AS THE FRONT LIFTS
NORTH OF THE LAKE A SOUTH TO SOUTHWEST FLOW WILL DEVELOP OVER THE
LAKE AND CONTINUE THROUGH THE END OF THE PERIOD. WITH A HOT AND
MUGGY AIRMASS OVER A MUCH COOLER LAKE WILL BE HARD FOR WINDS TO MIX
DOWN TO THE LAKE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...DJB
AVIATION...ADAMS
MARINE...DJB
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
351 PM EDT TUE MAY 28 2013
.SYNOPSIS...
A WARM FRONT WILL CONTINUE TO MOVE NORTH OF THE AREA THROUGH TONIGHT.
BY LATE WEDNESDAY THE FRONT WILL HAVE PUSHED WAY NORTH OF THE AREA
AND TEMPERATURES WILL BE WELL ABOVE NORMAL. A COLD FRONT IS
EXPECTED TO MOVE EAST ACROSS THE FORECAST AREA SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THE QUESTION IS STILL HOW MUCH CONVECTION WILL OCCUR THIS EVENING
AND TONIGHT. WE HAVE REACHED THE CONVECTIVE TEMPERATURES. THE
AIRMASS IS UNSTABLE AND MOIST BUT COULD BE MORE UNSTABLE. SOME OF
THE BETTER DYNAMICS ARE TO THE NORTH IN MICHIGAN. WENT MAINLY
CHANCE POPS. ACCORDING TO THE HRRR MODEL AND THE 4KM WRF NMM MODEL
ANOTHER WAVE WILL HIT THE AREA AFTER DARK. ON THE EDGE ABOUT THAT.
WENT ON THE WARMSIDE WITH THE LOWS BECAUSE OF THE MODERATELY HIGH
DEW POINTS. THREAT FOR SEVERE CONTINUES.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY NIGHT/...
WEDNESDAY IS TOUGH...SOME CONVECTION WILL BE IN THE AREA IN THE
MORNING BUT NOT SURE ABOUT THE AFTERNOON. KEPT THE CHANCE GOING.
DRY AND MUGGY WEDNESDAY NIGHT. THE MODELS ARE TRYING TO HINT AT
SOME CONVECTIVE ACTIVITY THURSDAY AFTERNOON. IT MAY JUST BE
ISOLATED SO LEFT IT OUT FOR THE MOMENT. INCLUDED A CHANCE STARTING
FRIDAY INTO FRIDAY NIGHT AS THE AIRMASS BECOMES MORE UNSTABLE.
USED A BLEND OF GUIDANCE FOR THE LOWS.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
MODELS IN REASONABLY GOOD AGREEMENT WITH THE NEXT FRONT MOVING
THROUGH EARLY SUNDAY...AFTER THAT THE MODELS DIVERGE. THE ECMWF
PUSHES THE FRONT SOUTH OF THE AREA BY SUNDAY EVENING TAKING THE RAIN
WITH IT. THE GFS ON THE OTHER HAND STALLS THE FRONT ACROSS THE AREA
AS A SECONDARY WAVE DEVELOPS AND MOVES ACROSS THE AREA SUNDAY NIGHT
INTO MONDAY. FOR NOW WITH SO MUCH UNCERTAINTY LEFT LIKELY POPS
SATURDAY NIGHT INTO SUNDAY WITH JUST LOW CHANCE POPS SUNDAY NIGHT
AND MONDAY. BOTH MODELS PUSH CANADIAN HIGH PRESSURE SOUTH OVER THE
AREA BY TUESDAY SO SHOULD BE DRY AND COOLER.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
WARM FRONT CURRENTLY NEAR A DTW TO ERI TO PIT LINE. WARM UNSTABLE
AIRMASS HAS SPREAD ACROSS THE AREA. CAPES HAVE RISEN TO 2500
J/KG IN THE WEST TO AROUND 1000 J/KG ELSEWHERE...EXPECT CAPES TO
RISE TO BETWEEN 2000-4000 J/KG BY LATE AFTERNOON. CLOUDS FROM
MORNING SHOWERS HAVE HELPED INSULATE AREA FROM TSRA FOR NOW.
EXPECT TSRA TO BUILD SW FROM SE LOWER MICHIGAN AND MOVE ACROSS THE
AREA THIS AFTERNOON AND EVENING. SPC HAS AREA IN SLIGHT RISK
COULD SEE ISOLATED SEVERE TSRA WIND GUSTS...BUT DO NOT NOT EXPECT
WIDESPREAD OUTBREAK. SECOND WAVE IS POSSIBLE OVERNIGHT AS TSRA
DEVELOP FROM ILLINOIS TO OKLAHOMA. MODELS NOT IN GOOD AGREEMENT
ON TIMING OF THE TSRA...SO USED TEMPOS IN TAFS TO GIVE WINDOW OF
BEST OPPORTUNITY.
.OUTLOOK...NON VFR POSSIBLE ON SATURDAY IN SHOWERS/THUNDERSTORMS.
&&
.MARINE...
...
A WARM FRONT STRETCHED ACROSS LAKE ERIE WILL PUSH NORTH OF THE LAKE
TONIGHT. CONVECTION LIKELY THIS EVENING INTO THE OVERNIGHT HOURS
SOME OF THE STORMS COULD BE STRONG TO SEVERE. AS THE FRONT LIFTS
NORTH OF THE LAKE A SOUTH TO SOUTHWEST FLOW WILL DEVELOP OVER THE
LAKE AND CONTINUE THROUGH THE END OF THE PERIOD. WITH A HOT AND
MUGGY AIRMASS OVER A MUCH COOLER LAKE WILL BE HARD FOR WINDS TO MIX
DOWN TO THE LAKE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...DJB
AVIATION...DJB
MARINE...DJB
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
220 PM EDT TUE MAY 28 2013
.SYNOPSIS...
WARM FRONT EXITING NORTHERN COUNTIES EARLY THIS MORNING. INCREASING
HEAT/HUMIDITY THIS AFTERNOON TO END OF THE WEEK. NO ORGANIZED
FRONTS IN VICINITY UNTIL WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
1030 AM UPDATE...INGESTED RECENT OBS. OVERALL FCST GENERALLY ON
TRACK. TWEAKED POPS AND SKY JUST A BIT TO REFLECT CURRENT RADAR
TRENDS...INCLUDING LOWERING POPS TO SLIGHT CHANCE ACROSS NE ZONES
AND INCREASING POPS A TAD WITH THIN BAND OF LIGHT SHOWERS NEAR THE
OHIO RIVER.
AT 10Z ON THE GRAVEYARD SHIFT...SHALLOW SURFACE WARM FRONT NOW
NORTH OF AREA.
A MID LEVEL 700 MB TROF AXIS WAS DEPICTED ON RAP AND VAD WINDS NR
ILN TO SDF AT 08Z...THEN CMH TO LEX AT 10Z. WEAK SUPPORT ASSOCIATED
WITH THAT FEATURE CROSSES OUR NORTHERN ZONES 12Z THRU 15Z. SO HAVE
SOME 20 TO 30 POPS ACROSS THE NORTH THIS MORNING FOR A LIGHT SHOWER.
YET...RAP FORECASTING SOUTHERN EXTENSION OF THAT VORT AXIS DRAGGING
THROUGH DURING THE LATE AFTERNOON. BOTH NAM AND GFS ON THEIR 00Z
RUNS...SHOW MID LEVEL WARMING AT AROUND 8 TO 10 THSD FT TRYING TO
FORM A CAP. SO WILL ONLY LEAVE SOME 20/30 POPS FOR THE POSSIBILITY
OF A DIURNAL DRIVEN INSTABILITY SHOWER OR THUNDERSTORM TO FORM THIS
AFTERNOON...MAINLY EAST AND SOUTH OF OHIO RIVER.
THE WARM UP STARTS IN EARNEST TODAY. OVERALL NO BIG CHANGES TO OUR
TEMPERATURE FORECAST.
MARGINAL 850 MB MOISTURE LINGERS OVERNIGHT...SO PATCHES OF 4 TO 7
THSD FT CLOUDS MAY STILL BE HANGING AROUND LATE TONIGHT. OF
COURSE...THIS CAUSES US HEADACHES TRYING TO FIGURE THE MINIMUM
TEMPERATURE TONIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
UPPER RIDGE CONTINUES TO BUILD THROUGH THURSDAY AFTERNOON.
TEMPERATURES WILL TOP OUT THURSDAY AFTERNOON WITH THE WARMEST
READINGS SO FAR THIS YEAR. USED A MAV/MET BLEND FOR WEDNESDAY AND
THURSDAY...WHICH BUMPED UP AFTERNOON HIGHS JUST A BIT EACH DAY. THE
RIDGE STARTS BREAKING DOWN BY FRIDAY AS AN UPPER TROUGH BEGINS TO
DROP INTO THE UPPER PLAINS. PRECIP WISE...HAVE DIURNAL SHOWERS AND
STORMS IN THE WV MOUNTAINS EACH AFTERNOON DUE TO ELEVATED HEAT
SOURCE INSTABILITY...AND ALSO INCLUDED SOME AFTERNOON CONVECTION IN
SE OHIO FRIDAY AFTERNOON AS TEMPS ALOFT COOL A BIT AND A 500MB
RIPPLE STREAMS ACROSS OHIO.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
GFS/ECMWF BEGIN TO DIVERGE BY THE WEEKEND WITH THE POSITION OF THE
COLD FRONT ASSOCIATED WITH OUR NEXT SYSTEM...GFS BREAKS THE RIDGE
DOWN FASTER ALLOWING THE COLD FRONT TO ENTER OUR WESTERN COUNTIES
EARLY SATURDAY WHILE THE ECMWF CONTINUES TO AMPLIFY THE RIDGE OVER
THE SE STATES THROUGH SATURDAY NOT ALLOWING FOR FROPA ACROSS OUR CWA
UNTIL LATER IN THE DAY SUNDAY...GIVEN THE MORE LINEAR SOLUTION OF
THE GFS AND EXPECTED INFLUENCE OF CONVECTIVE PROCESSES ASSOCIATED
WITH THE FRONT WILL PUT MORE WEIGHT ON ECMWF TIMING...ZONAL FLOW
APPEARS TO MOVE IN BEHIND THE TROUGH OUT TO DAY 6 AND 7.
&&
.AVIATION /18Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH THE VALID PERIOD. SCATTERED
CEILINGS AROUND 6KFT TO 8KFT WILL CONTINUE HOWEVER THIS AFTERNOON
AND OVERNIGHT...WITH THE POSSIBILITY OF A BRIEF SHOWER OR EVEN AN
ISOLATED THUNDERSTORM MAINLY ACROSS SE OHIO OR NE WEST VIRGINIA.
WIND SPEEDS WILL REMAIN A BIT GUSTY THIS AFTERNOON BUT SUBSIDE BY
ABOUT 00Z. OVERNIGHT A FEW TO SCATTERED MID LEVEL DECK SHOULD
PERSIST WITH ANY PRECIP ENDING BY 03Z. DECENT BOUNDARY LAYER WINDS
WITH THE CLOUDS SHOULD PRECLUDE WIDESPREAD DENSE FOG AND LOW
STRATUS DEVELOPMENT OVERNIGHT...THOUGH SOME PATCHY MVFR VIS IS
POSSIBLE AT THE USUAL SPOTS SUCH AS EKN. FEW TO SCATTERED MID-LEVEL
CLOUDS WILL CONTINUE WED MORNING AS WELL...WITH MORE BREAKS EXPECTED.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...
FORECAST CONFIDENCE...MEDIUM.
ALTERNATE SCENARIOS: COVERAGE OF PRECIP MAY VARY SLIGHTLY. REDUCED
VISIBILITY DURING THE OVERNIGHT HOURS 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 H H
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 WEDNESDAY...
NO WIDESPREAD IFR EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...KTB/50
SHORT TERM...MZ
LONG TERM...JM
AVIATION...50
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1039 AM EDT TUE MAY 28 2013
.SYNOPSIS...
WARM FRONT EXITING NORTHERN COUNTIES EARLY THIS MORNING. INCREASING
HEAT/HUMIDITY THIS AFTERNOON TO END OF THE WEEK. NO ORGANIZED
FRONTS IN VICINITY UNTIL WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
1030 AM UPDATE...INGESTED RECENT OBS. OVERALL FCST GENERALLY ON
TRACK. TWEAKED POPS AND SKY JUST A BIT TO REFLECT CURRENT RADAR
TRENDS...INCLUDING LOWERING POPS TO SLIGHT CHANCE ACROSS NE ZONES
AND INCREASING POPS A TAD WITH THIN BAND OF LIGHT SHOWERS NEAR THE
OHIO RIVER.
AT 10Z ON THE GRAVEYARD SHIFT...SHALLOW SURFACE WARM FRONT NOW
NORTH OF AREA.
A MID LEVEL 700 MB TROF AXIS WAS DEPICTED ON RAP AND VAD WINDS NR
ILN TO SDF AT 08Z...THEN CMH TO LEX AT 10Z. WEAK SUPPORT ASSOCIATED
WITH THAT FEATURE CROSSES OUR NORTHERN ZONES 12Z THRU 15Z. SO HAVE
SOME 20 TO 30 POPS ACROSS THE NORTH THIS MORNING FOR A LIGHT SHOWER.
YET...RAP FORECASTING SOUTHERN EXTENSION OF THAT VORT AXIS DRAGGING
THROUGH DURING THE LATE AFTERNOON. BOTH NAM AND GFS ON THEIR 00Z
RUNS...SHOW MID LEVEL WARMING AT AROUND 8 TO 10 THSD FT TRYING TO
FORM A CAP. SO WILL ONLY LEAVE SOME 20/30 POPS FOR THE POSSIBILITY
OF A DIURNAL DRIVEN INSTABILITY SHOWER OR THUNDERSTORM TO FORM THIS
AFTERNOON...MAINLY EAST AND SOUTH OF OHIO RIVER.
THE WARM UP STARTS IN EARNEST TODAY. OVERALL NO BIG CHANGES TO OUR
TEMPERATURE FORECAST.
MARGINAL 850 MB MOISTURE LINGERS OVERNIGHT...SO PATCHES OF 4 TO 7
THSD FT CLOUDS MAY STILL BE HANGING AROUND LATE TONIGHT. OF
COURSE...THIS CAUSES US HEADACHES TRYING TO FIGURE THE MINIMUM
TEMPERATURE TONIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
UPPER RIDGE CONTINUES TO BUILD THROUGH THURSDAY AFTERNOON.
TEMPERATURES WILL TOP OUT THURSDAY AFTERNOON WITH THE WARMEST
READINGS SO FAR THIS YEAR. USED A MAV/MET BLEND FOR WEDNESDAY AND
THURSDAY...WHICH BUMPED UP AFTERNOON HIGHS JUST A BIT EACH DAY. THE
RIDGE STARTS BREAKING DOWN BY FRIDAY AS AN UPPER TROUGH BEGINS TO
DROP INTO THE UPPER PLAINS. PRECIP WISE...HAVE DIURNAL SHOWERS AND
STORMS IN THE WV MOUNTAINS EACH AFTERNOON DUE TO ELEVATED HEAT
SOURCE INSTABILITY...AND ALSO INCLUDED SOME AFTERNOON CONVECTION IN
SE OHIO FRIDAY AFTERNOON AS TEMPS ALOFT COOL A BIT AND A 500MB
RIPPLE STREAMS ACROSS OHIO.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
GFS/ECMWF BEGIN TO DIVERGE BY THE WEEKEND WITH THE POSITION OF THE
COLD FRONT ASSOCIATED WITH OUR NEXT SYSTEM...GFS BREAKS THE RIDGE
DOWN FASTER ALLOWING THE COLD FRONT TO ENTER OUR WESTERN COUNTIES
EARLY SATURDAY WHILE THE ECMWF CONTINUES TO AMPLIFY THE RIDGE OVER
THE SE STATES THROUGH SATURDAY NOT ALLOWING FOR FROPA ACROSS OUR CWA
UNTIL LATER IN THE DAY SUNDAY...GIVEN THE MORE LINEAR SOLUTION OF
THE GFS AND EXPECTED INFLUENCE OF CONVECTIVE PROCESSES ASSOCIATED
WITH THE FRONT WILL PUT MORE WEIGHT ON ECMWF TIMING...ZONAL FLOW
APPEARS TO MOVE IN BEHIND THE TROUGH OUT TO DAY 6 AND 7.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
PATCHY CEILINGS AT 6 TO 8 THSD FT 15Z WITH ISOLATED TO SCATTERED
LIGHT SHOWERS POSSIBLE...MAINLY ACROSS EASTERN OHIO AND NORTHERN
HALF OF WEST VIRGINIA. VSBY MAY LOWER BRIEFLY TO 6 OR 5 MILES.
SCATTERED TO BROKEN CLOUDS AT 4 TO 5 THSD FT AGL 14Z THROUGH 23Z
WITH INCREASING SURFACE WINDS FROM THE SOUTHWEST.
ISOLATED CONVECTION MAY FORM 18Z TODAY TO 00Z WEDNESDAY. 00Z NAM
AND GFS TRY TO WARM HE MID LEVELS AT 8 TO 10 THSD FT MSL JUST ENOUGH
TO FORM CAP. YET...A WEAK VORT MAX AT 500 MB AND INCREASING SURFACE
HEATING...HAS US STILL MENTIONING THE POSSIBILITY OF ISOLATED
CONVECTION.
MARGINAL 850 MB MOISTURE LINGERS TONIGHT AS SURFACE WINDS DECREASE.
SO PATCHES OF 4 TO 6 THSD FT AGL SCATTERED TO BROKEN CLOUDS WITH
CIRRUS ABOVE. SOME 5 TO 6 MILES IN HAZE MAY FORM IN THE MOUNTAIN
VALLEYS VCNTY EKN FOR THE 06Z TO 12Z WEDNESDAY TIME FRAME.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY...
FORECAST CONFIDENCE...MEDIUM.
ALTERNATE SCENARIOS: ISOLATED AFTERNOON CONVECTION MAY NOT FORM WITH
DEVELOPING MID LEVEL WARMING/CAP.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z WEDNESDAY...
NO WIDESPREAD IFR EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...KTB/50
SHORT TERM...MZ
LONG TERM...JM
AVIATION...KTB
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1007 AM EDT TUE MAY 28 2013
.SYNOPSIS...
A WARM FRONT FROM THE MIDWEST TO THE OHIO VALLEY WILL SLOWLY PUSH
NORTHEAST TODAY AND TONIGHT. THIS WILL PUT THE LOCAL AREA IN
POSITION FOR SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS. BY LATE
WEDNESDAY THE FRONT WILL HAVE PUSHED NORTH OF THE AREA AND
TEMPERATURES WILL BE WELL ABOVE NORMAL. A COLD FRONT IS EXPECTED
TO MOVE EAST ACROSS OHIO SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE BIG QUESTION IS HOW MUCH SHOWER AND THUNDERSTORM ACTIVITY WILL
OCCUR THIS AFTERNOON. A WAVE IS MOVING THROUGH NOW AND THEN MORE
SHOWERS AND THUNDERSTORMS WILL AFFECT EXTREME NW OH AND THE
EASTERN COUNTIES THIS AFTERNOON. GOING WITH THE HRRR AND THE 4KM
WRF NMM MODEL. WATCHING TO SEE HOW MUCH FILTERED SUNSHINE WE GET...THAT
WILL BE KEY. NW OH IS GETTING SOME NOW BUT THAT SHOULD BE GOING
AWAY BY NOON AND THE MORE SIGNIFICANT SUNSHINE MAY STAY SOUTH OF
THE AREA. CONTINUED WITH SPC SLIGHT RISK OF SEVERE ACROSS THE
ENTIRE FORECAST AREA.
PREVIOUS DISCUSSION...
ONE BATCH OF STEADY RAIN WILL BE PULLING OUT TO THE EAST EARLY
THIS MORNING...BUT RIGHT ON ITS HEELS IS THE NEXT CLUSTER OF
SHOWERS AND THUNDERSTORMS ACROSS NW OH...WITH ANOTHER UPSTREAM OF
THAT. WITH A RELATIVELY FLAT RIDGE ACROSS THE OHIO VALLEY...WEAK
DISTURBANCES IN THE FLOW WILL KEEP THE WARM FRONT ACTIVE FOR THE
NEXT 24 TO 36 HOURS. BIG QUESTION TODAY WILL BE HOW WELL WILL WE
DESTABILIZE. AS PER SPC DISCUSSION...REMNANT MCV FROM UPSTREAM
CONVECTION/SHORTWAVE WILL BE THE KICKER FOR STORMS TODAY...SOME OF
WHICH COULD BECOME STRONG TO SEVERE WITH WIND THE PRIMARY THREAT.
THE RAINFALL WILL BE NEEDED AS WE ARE RUNNING 2 TO NEARLY 3 INCHES
BELOW NORMAL SINCE MARCH 1ST. TEMPERATURES WILL BE AN IMPROVEMENT
OVER YESTERDAY. WENT CLOSER TO GUIDANCE...BUT STUCK JUST A BIT
COOLER. UPDATE INCLUDES TWEAKS TO VERY NEAR TERM PRECIP
CHANCES...TIMING THE BATCH FROM NW OHIO IN TO THE AREA. PRECIP
CHANCES END UP SOUNDING VAGUE WITH CHANCES FOR MUCH OF TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
IT WILL LIKELY TAKE UNTIL WEDNESDAY...POSSIBLY WEDNESDAY AFTERNOON
BEFORE WARM FRONT LIFTS FAR ENOUGH NORTH TO CLEAR US FROM A THREAT
OF SHOWERS AND THUNDERSTORMS. TIMING ANY OF THIS NEARLY IMPOSSIBLE
YET. WILL CONTINUE THE BETTER CHANCES FOR SHOWERS/THUNDERSTORMS
ACROSS THE NORTH TONIGHT AND THEN A FEW SCATTERED
SHOWERS/THUNDERSTORMS FOR WEDNESDAY. RELATIVELY MILD NIGHTS COMING
UP WITH LOWS IN THE 60S. HIGHS WILL INCH UP INTO THE 80S...WITH
MID AND UPPER 80S FOR THURSDAY. RIDGE BEGINS TO SHIFT EAST FRIDAY
AND WE MAY BE ABLE TO KNOCK A FEW DEGREES OFF HIGHS. MINIMAL
CHANCES FOR SHOWERS AND THUNDERSTORMS RETURNING FRIDAY NIGHT FROM
THE WEST AS ENERGY SHEARS OUT FROM THE CENTRAL PLAINS TROUGH
TOWARD THE LOWER GREAT LAKES.
GIVEN THE RELATIVELY DRY CONDITIONS OVER MOST OF THE PAST FEW
WEEKS...DON`T SEE MUCH OF A FLOOD THREAT. HOWEVER...THE SITUATION
MAY ALLOW FOR SOME REPEATED HEAVY RAINS IN SOME LOCATIONS SO
THINGS COULD CHANGE LOCALLY.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
THE NEXT COLD FRONT IS DUE ON SUNDAY. THERE IS SOME QUESTIONS AS TO
HOW FAR AHEAD OF THE FRONT WE CAN GET THUNDERSTORMS. MOST OF THE
MODELS HAVE BEEN POSTING QPF AND INDICATING SHOWERS AND STORMS ON
SATURDAY. IT SHOULD BE WARM AND UNSTABLE AND WILL KEEP A CHANCE OF
SHOWERS/STORMS IN THE FORECAST...WITH LIKELY POPS FOR NORTHWEST OHIO
ON SATURDAY. MOST OF THE MODELS ARE ALSO HINTING AT A SECONDARY COLD
FRONT SUNDAY NIGHT. WILL TRIM BACK TEMPERATURES A BIT BY MONDAY...A
LITTLE BELOW NORMAL...FOR FEAR OF CLOUDS AND A COOLER NORTHWEST FLOW
AS THE UPPER TROUGH SWINGS ACROSS THE AREA.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
A WARM FRONT WILL BE SLOWLY MOVING NORTH ACROSS THE AREA TODAY
INTO TONIGHT. SEVERAL ROUNDS OF SHOWERS/STORMS ARE LIKELY AND IT WILL
BE DIFFICULT TO TIME THE SHOWERS. THE CURRENT BATCH OF SHOWERS
SHOULD MOVE EAST OF THE AREA MID MORNING. ANOTHER ROUND OF
SHOWERS WILL PROBABLY REACH NORTHWEST OHIO EARLY THIS AFTERNOON AND
SPREAD ACROSS THE FORECAST AREA THIS AFTERNOON. THUNDER IS
POSSIBLE THIS MORNING BUT WILL LIMIT IT IN THE TAFS THIS MORNING
BUT HAVE IT IN THE FORECAST FOR THIS AFTERNOON. ADDITIONAL SHOWERS
ARE A GOOD BET ACROSS NORTHERN OHIO THE FIRST PART OF TONIGHT UNTIL
THEY LIFT NORTH OF LAKE ERIE.
.OUTLOOK...NON VFR POSSIBLE ON SATURDAY IN SHOWERS/THUNDERSTORMS.
&&
.MARINE...
A WARM FRONT OVER THE OHIO VALLEY WILL LIFT NORTH...CROSSING LAKE
ERIE TONIGHT. THE WIND WILL VEER FROM THE EAST TO THE SOUTHEAST AND
THEN THE SOUTH TODAY AND TONIGHT WITH THE PASSAGE OF THE WARM FRONT.
HIGH PRESSURE OFF THE CAROLINA COAST WILL BUILD THIS WEEK. THE AIR
MASS WILL BECOME WARM. THE STABILITY OVER THE COOLER LAKE WILL KEEP
THE SOUTH TO SOUTHWEST WINDS LIGHT TO MODERATE ALL WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...OUDEMAN
NEAR TERM...KIELTYKA/OUDEMAN
SHORT TERM...OUDEMAN
LONG TERM...KOSARIK
AVIATION...KOSARIK
MARINE...KOSARIK
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
628 AM EDT TUE MAY 28 2013
.SYNOPSIS...
WARM FRONT EXITING NORTHERN COUNTIES EARLY THIS MORNING. INCREASING
HEAT/HUMIDITY THIS AFTERNOON TO END OF THE WEEK. NO ORGANIZED
FRONTS IN VICINITY UNTIL WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT 10Z ON THE GRAVEYARD SHIFT...SHALLOW SURFACE WARM FRONT NOW
NORTH OF AREA.
A MID LEVEL 700 MB TROF AXIS WAS DEPICTED ON RAP AND VAD WINDS NR
ILN TO SDF AT 08Z...THEN CMH TO LEX AT 10Z. WEAK SUPPORT ASSOCIATED
WITH THAT FEATURE CROSSES OUR NORTHERN ZONES 12Z THRU 15Z. SO HAVE
SOME 20 TO 30 POPS ACROSS THE NORTH THIS MORNING FOR A LIGHT SHOWER.
YET...RAP FORECASTING SOUTHERN EXTENSION OF THAT VORT AXIS DRAGGING
THROUGH DURING THE LATE AFTERNOON. BOTH NAM AND GFS ON THEIR 00Z
RUNS...SHOW MID LEVEL WARMING AT AROUND 8 TO 10 THSD FT TRYING TO
FORM A CAP. SO WILL ONLY LEAVE SOME 20/30 POPS FOR THE POSSIBILITY
OF A DIURNAL DRIVEN INSTABILITY SHOWER OR THUNDERSTORM TO FORM THIS
AFTERNOON...MAINLY EAST AND SOUTH OF OHIO RIVER.
THE WARM UP STARTS IN EARNEST TODAY. OVERALL NO BIG CHANGES TO OUR
TEMPERATURE FORECAST.
MARGINAL 850 MB MOISTURE LINGERS OVERNIGHT...SO PATCHES OF 4 TO 7
THSD FT CLOUDS MAY STILL BE HANGING AROUND LATE TONIGHT. OF
COURSE...THIS CAUSES US HEADACHES TRYING TO FIGURE THE MINIMUM
TEMPERATURE TONIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
UPPER RIDGE CONTINUES TO BUILD THROUGH THURSDAY AFTERNOON.
TEMPERATURES WILL TOP OUT THURSDAY AFTERNOON WITH THE WARMEST
READINGS SO FAR THIS YEAR. USED A MAV/MET BLEND FOR WEDNESDAY AND
THURSDAY...WHICH BUMPED UP AFTERNOON HIGHS JUST A BIT EACH DAY. THE
RIDGE STARTS BREAKING DOWN BY FRIDAY AS AN UPPER TROUGH BEGINS TO
DROP INTO THE UPPER PLAINS. PRECIP WISE...HAVE DIURNAL SHOWERS AND
STORMS IN THE WV MOUNTAINS EACH AFTERNOON DUE TO ELEVATED HEAT
SOURCE INSTABILITY...AND ALSO INCLUDED SOME AFTERNOON CONVECTION IN
SE OHIO FRIDAY AFTERNOON AS TEMPS ALOFT COOL A BIT AND A 500MB
RIPPLE STREAMS ACROSS OHIO.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
GFS/ECMWF BEGIN TO DIVERGE BY THE WEEKEND WITH THE POSITION OF THE
COLD FRONT ASSOCIATED WITH OUR NEXT SYSTEM...GFS BREAKS THE RIDGE
DOWN FASTER ALLOWING THE COLD FRONT TO ENTER OUR WESTERN COUNTIES
EARLY SATURDAY WHILE THE ECMWF CONTINUES TO AMPLIFY THE RIDGE OVER
THE SE STATES THROUGH SATURDAY NOT ALLOWING FOR FROPA ACROSS OUR CWA
UNTIL LATER IN THE DAY SUNDAY...GIVEN THE MORE LINEAR SOLUTION OF
THE GFS AND EXPECTED INFLUENCE OF CONVECTIVE PROCESSES ASSOCIATED
WITH THE FRONT WILL PUT MORE WEIGHT ON ECMWF TIMING...ZONAL FLOW
APPEARS TO MOVE IN BEHIND THE TROUGH OUT TO DAY 6 AND 7.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
PATCHY CEILINGS AT 6 TO 8 THSD FT 15Z WITH ISOLATED TO SCATTERED
LIGHT SHOWERS POSSIBLE...MAINLY ACROSS EASTERN OHIO AND NORTHERN
HALF OF WEST VIRGINIA. VSBY MAY LOWER BRIEFLY TO 6 OR 5 MILES.
SCATTERED TO BROKEN CLOUDS AT 4 TO 5 THSD FT AGL 14Z THROUGH 23Z
WITH INCREASING SURFACE WINDS FROM THE SOUTHWEST.
ISOLATED CONVECTION MAY FORM 18Z TODAY TO 00Z WEDNESDAY. 00Z NAM
AND GFS TRY TO WARM HE MID LEVELS AT 8 TO 10 THSD FT MSL JUST ENOUGH
TO FORM CAP. YET...A WEAK VORT MAX AT 500 MB AND INCREASING SURFACE
HEATING...HAS US STILL MENTIONING THE POSSIBILITY OF ISOLATED
CONVECTION.
MARGINAL 850 MB MOISTURE LINGERS TONIGHT AS SURFACE WINDS DECREASE.
SO PATCHES OF 4 TO 6 THSD FT AGL SCATTERED TO BROKEN CLOUDS WITH
CIRRUS ABOVE. SOME 5 TO 6 MILES IN HAZE MAY FORM IN THE MOUNTAIN
VALLEYS VCNTY EKN FOR THE 06Z TO 12Z WEDNESDAY TIME FRAME.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY...
FORECAST CONFIDENCE...MEDIUM.
ALTERNATE SCENARIOS: ISOLATED AFTERNOON CONVECTION MAY NOT FORM WITH
DEVELOPING MID LEVEL WARMING/CAP.
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 11 12 13 14 15 16 17 18 19 20 21 22
EDT 1HRLY 07 08 09 10 11 12 13 14 15 16 17 18
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 H H
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 12Z WEDNESDAY...
NO WIDESPREAD IFR EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...KTB
SHORT TERM...MZ
LONG TERM...JM
AVIATION...KTB
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
355 AM EDT TUE MAY 28 2013
.SYNOPSIS...
WARM FRONT LIFTING NORTH SHOULD EXIT CWA THIS MORNING. INCREASING
HEAT/HUMIDITY THIS AFTERNOON TO END OF THE WEEK. NO ORGANIZED
FRONTS IN VICINITY UNTIL WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT 07Z ON THE GRAVEYARD SHIFT...SHALLOW SURFACE WARM FRONT NOW NORTH
OF PKB TO NEAR CKB/MGW. YET...925 MB FRONT ALREADY WELL TO THE
NORTH. 925 MB WINDS ON VAD ABOUT 30 KNOTS...KEEPING SOME HILLTOPS
MILDER THAN ADJACENT VALLEYS.
A MID LEVEL 700 MB TROF AXIS WAS DEPICTED ON RAP AND VAD WINDS NR
ILN TO SDF AT 08Z. WEAK SUPPORT ASSOCIATED WITH THAT FEATURE
CROSSES OUR NORTHERN ZONES 12Z THRU 15Z. SO HAVE SOME 20 TO 30 POPS
ACROSS THE NORTH THIS MORNING FOR A LIGHT SHOWER.
YET...RAP FORECASTING SOUTHERN EXTENSION OF THAT VORT AXIS DRAGGING
THROUGH DURING THE LATE AFTERNOON. BOTH NAM AND GFS ON THEIR 00Z
RUNS...SHOW MID LEVEL WARMING AT AROUND 8 TO 10 THSD FT TRYING TO
FORM A CAP. SO WILL ONLY LEAVE SOME 20/30 POPS FOR THE POSSIBILITY
OF A DIURNAL DRIVEN INSTABILITY SHOWER OR THUNDERSTORM TO FORM THIS
AFTERNOON...MAINLY EAST AND SOUTH OF OHIO RIVER.
THE WARM UP STARTS IN EARNEST TODAY. OVERALL NO BIG CHANGES TO OUR
TEMPERATURE FORECAST.
MARGINAL 850 MB MOISTURE LINGERS OVERNIGHT...SO PATCHES OF 4 TO 7
THSD FT CLOUDS MAY STILL BE HANGING AROUND LATE TONIGHT. OF
COURSE...THIS CAUSES US HEADACHES TRYING TO FIGURE THE MINIMUM
TEMPERATURE TONIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
UPPER RIDGE CONTINUES TO BUILD THROUGH THURSDAY AFTERNOON.
TEMPERATURES WILL TOP OUT THURSDAY AFTERNOON WITH THE WARMEST
READINGS SO FAR THIS YEAR. USED A MAV/MET BLEND FOR WEDNESDAY AND
THURSDAY...WHICH BUMPED UP AFTERNOON HIGHS JUST A BIT EACH DAY. THE
RIDGE STARTS BREAKING DOWN BY FRIDAY AS AN UPPER TROUGH BEGINS TO
DROP INTO THE UPPER PLAINS. PRECIP WISE...HAVE DIURNAL SHOWERS AND
STORMS IN THE WV MOUNTAINS EACH AFTERNOON DUE TO ELEVATED HEAT
SOURCE INSTABILITY...AND ALSO INCLUDED SOME AFTERNOON CONVECTION IN
SE OHIO FRIDAY AFTERNOON AS TEMPS ALOFT COOL A BIT AND A 500MB
RIPPLE STREAMS ACROSS OHIO.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
GFS/ECMWF BEGIN TO DIVERGE BY THE WEEKEND WITH THE POSITION OF THE
COLD FRONT ASSOCIATED WITH OUR NEXT SYSTEM...GFS BREAKS THE RIDGE
DOWN FASTER ALLOWING THE COLD FRONT TO ENTER OUR WESTERN COUNTIES
EARLY SATURDAY WHILE THE ECMWF CONTINUES TO AMPLIFY THE RIDGE OVER
THE SE STATES THROUGH SATURDAY NOT ALLOWING FOR FROPA ACROSS OUR CWA
UNTIL LATER IN THE DAY SUNDAY...GIVEN THE MORE LINEAR SOLUTION OF
THE GFS AND EXPECTED INFLUENCE OF CONVECTIVE PROCESSES ASSOCIATED
WITH THE FRONT WILL PUT MORE WEIGHT ON ECMWF TIMING...ZONAL FLOW
APPEARS TO MOVE IN BEHIND THE TROUGH OUT TO DAY 6 AND 7.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
PATCHY CEILINGS AT 5 TO 8 THSD FT 06Z THROUGH 14Z WITH ISOLATED TO
SCATTERED LIGHT SHOWERS POSSIBLE...MAINLY ACROSS EASTERN OHIO AND
NORTHERN HALF OF WEST VIRGINIA. VSBY MAY LOWER BRIEFLY TO 5 MILES.
SCATTERED TO BROKEN CLOUDS AT 4 TO 5 THSD FT AGL 14Z THROUGH 23Z
WITH INCREASING SURFACE WINDS FROM THE SOUTHWEST.
ISOLATED CONVECTION MAY FORM 18Z TODAY TO 00Z WEDNESDAY. 00Z NAM
AND GFS TRY TO WARM HE MID LEVELS AT 8 TO 10 THSD FT MSL JUST ENOUGH
TO FORM CAP. YET...A WEAK VORT MAX AT 500 MB AND INCREASING SURFACE
HEATING...HAS US STILL MENTIONING THE POSSIBILITY OF ISOLATED
CONVECTION.
MARGINAL 850 MB MOISTURE LINGERS TONIGHT AS SURFACE WINDS DECREASE.
SO PATCHES OF 4 TO 6 THSD FT AGL SCATTERED TO BROKEN CLOUDS. SOME 5
TO 6 MILES IN HAZE MAY FORM IN THE MOUNTAIN VALLEYS VCNTY EKN BY 06Z
WEDNESDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY...
FORECAST CONFIDENCE...MEDIUM.
ALTERNATE SCENARIOS: ISOLATED AFTERNOON CONVECTION MAY NOT FORM WITH
DEVELOP MID LEVEL WARMING/CAP.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE TUE 05/28/13
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EDT 1HRLY 04 05 06 07 08 09 10 11 12 13 14 15
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 H H
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 06Z WEDNESDAY...
NO WIDESPREAD IFR EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...KTB
SHORT TERM...MZ
LONG TERM...JM
AVIATION...KTB
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
345 AM EDT TUE MAY 28 2013
.SYNOPSIS...
WARM FRONT LIFTING NORTH SHOULD EXIT CWA THIS MORNING. INCREASING
HEAT/HUMIDITY THIS AFTERNOON TO END OF THE WEEK. NO ORGANIZED
FRONTS IN VICINITY UNTIL WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT 07Z ON THE GRAVEYARD SHIFT...SHALLOW SURFACE WARM FRONT NOW NORTH
OF PKB TO NEAR CKB/MGW. YET...925 MB FRONT ALREADY WELL TO THE
NORTH. 925 MB WINDS ON VAD ABOUT 30 KNOTS...KEEPING SOME HILLTOPS
MILDER THAN ADJACENT VALLEYS.
A MID LEVEL 700 MB TROF AXIS WAS DEPICTED ON RAP AND VAD WINDS NR
ILN TO SDF AT 08Z. WEAK SUPPORT ASSOCIATED WITH THAT FEATURE
CROSSES OUR NORTHERN ZONES 12Z THRU 15Z. SO HAVE SOME 20 TO 30 POPS
ACROSS THE NORTH THIS MORNING FOR A LIGHT SHOWER.
YET...RAP FORECASTING SOUTHERN EXTENSION OF THAT VORT AXIS DRAGGING
THROUGH DURING THE LATE AFTERNOON. BOTH NAM AND GFS ON THEIR 00Z
RUNS...SHOW MID LEVEL WARMING AT AROUND 8 TO 10 THSD FT TRYING TO
FORM A CAP. SO WILL ONLY LEAVE SOME 20/30 POPS FOR THE POSSIBILITY
OF A DIURNAL DRIVEN INSTABILITY SHOWER OR THUNDERSTORM TO FORM THIS
AFTERNOON...MAINLY EAST AND SOUTH OF OHIO RIVER.
THE WARM UP STARTS IN EARNEST TODAY. OVERALL NO BIG CHANGES TO OUR
TEMPERATURE FORECAST.
MARGINAL 850 MB MOISTURE LINGERS OVERNIGHT...SO PATCHES OF 4 TO 7
THSD FT CLOUDS MAY STILL BE HANGING AROUND LATE TONIGHT. OF
COURSE...THIS CAUSES US HEADACHES TRYING TO FIGURE THE MINIMUM
TEMPERATURE TONIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
MODELS ARE IN STRONG AGREEMENT FOR THE FIRST PORTION OF THE LONG
TERM FORECAST...THURSDAY THROUGH LATE FRIDAY...POSITIONING AN UPPER
LEVEL LOW OVER THE NORTHERN GREAT LAKES WITH AN AMPLIFIED SURFACE
HIGH CENTERED JUST OFF SHORE THE MID ATLANTIC STATES WITH A WELL
ADVERTISED WARM UP IN FULL FORCE...HAVE KEPT SLIGHT POPS OVER
PORTIONS OF EASTERN MTNS DUE TO MOISTURE RICH UPSLOPE FLOW THURSDAY
AND FRIDAY...GFS/ECMWF BEGIN TO DIVERGE LATE FRIDAY WITH THE
POSITION OF THE COLD FRONT ASSOCIATED WITH OUR NEXT SYSTEM...GFS
BREAKS THE RIDGE DOWN FASTER ALLOWING THE COLD FRONT TO ENTER OUR
WESTERN COUNTIES EARLY SATURDAY WHILE THE ECMWF CONTINUES TO AMPLIFY
THE RIDGE OVER THE SE STATES THROUGH SATURDAY NOT ALLOWING FOR FROPA
ACROSS OUR CWA UNTIL LATER IN THE DAY SUNDAY...GIVEN THE MORE LINEAR
SOLUTION OF THE GFS AND EXPECTED INFLUENCE OF CONVECTIVE PROCESSES
ASSOCIATED WITH THE FRONT WILL PUT MORE WEIGHT ON ECMWF
TIMING...ZONAL FLOW APPEARS TO MOVE IN BEHIND THE TROUGH OUT TO DAY
6 AND 7...
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
PATCHY CEILINGS AT 5 TO 8 THSD FT 06Z THROUGH 14Z WITH ISOLATED TO
SCATTERED LIGHT SHOWERS POSSIBLE...MAINLY ACROSS EASTERN OHIO AND
NORTHERN HALF OF WEST VIRGINIA. VSBY MAY LOWER BRIEFLY TO 5 MILES.
SCATTERED TO BROKEN CLOUDS AT 4 TO 5 THSD FT AGL 14Z THROUGH 23Z
WITH INCREASING SURFACE WINDS FROM THE SOUTHWEST.
ISOLATED CONVECTION MAY FORM 18Z TODAY TO 00Z WEDNESDAY. 00Z NAM
AND GFS TRY TO WARM HE MID LEVELS AT 8 TO 10 THSD FT MSL JUST ENOUGH
TO FORM CAP. YET...A WEAK VORT MAX AT 500 MB AND INCREASING SURFACE
HEATING...HAS US STILL MENTIONING THE POSSIBILITY OF ISOLATED
CONVECTION.
MARGINAL 850 MB MOISTURE LINGERS TONIGHT AS SURFACE WINDS DECREASE.
SO PATCHES OF 4 TO 6 THSD FT AGL SCATTERED TO BROKEN CLOUDS. SOME 5
TO 6 MILES IN HAZE MAY FORM IN THE MOUNTAIN VALLEYS VCNTY EKN BY 06Z
WEDNESDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY...
FORECAST CONFIDENCE...MEDIUM.
ALTERNATE SCENARIOS: ISOLATED AFTERNOON CONVECTION MAY NOT FORM WITH
DEVELOP MID LEVEL WARMING/CAP.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE TUE 05/28/13
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EDT 1HRLY 04 05 06 07 08 09 10 11 12 13 14 15
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 H H
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 06Z WEDNESDAY...
NO WIDESPREAD IFR EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...KTB
SHORT TERM...MZ
LONG TERM...JM
AVIATION...KTB
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
158 AM EDT TUE MAY 28 2013
.SYNOPSIS...
A WARM FRONT ACROSS THE AREA WILL LIFT NORTH OF THE REGION
OVERNIGHT. A DISTURBANCE WILL APPROACH THE AREA ON TUESDAY
BRINGING ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS TO PORTIONS
OF THE REGION. HIGH PRESSURE WILL BE PRESENT ACROSS THE AREA FOR
THE MIDDLE OF THE WEEK BEFORE UNSETTLED WEATHER RETURNS FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
SURFACE LOW IS PUSHING EAST ACROSS CENTRAL INDIANA WITH A WARM
FRONT EXTENDING EAST ACROSS CENTRAL OHIO. SHOWERS AND
THUNDERSTORMS ARE CONTINUING TO WORK EAST ALONG AND NORTH OF THE
WARM FRONT...PRIMARILY AFFECTING OUR FAR NORTHERN COUNTIES. THESE
SHOWERS/THUNDERSTORMS HAVE BEEN CONSISTENTLY WEAKENING AS THEY PUSH
INTO OUR NORTHERN AREAS AND EXPECT THIS TREND TO CONTINUE BEFORE THEY
GENERALLY TAPER OFF OVERNIGHT AS THE WARM LIFTS NORTH AND WE
ALSO LOSE THE BETTER INSTABILITY. MEANWHILE A LINE OF THUNDERSTORMS
IS MOVING EAST ALONG A TROUGH AXIS EXTENDING SOUTHWEST FROM THE
LOW ACROSS SOUTHWEST INDIANA. EXPECT THESE TOO TO WEAKEN AS THEY
PUSH EAST THROUGH LATE EVENING AND THE INSTABILITY BEGINS TO
WEAKEN. THAT BEING SAID...THE EASTWARD EXTENT REMAINS SOMEWHAT IN
DOUBT. THE LATEST HRRR IS TRYING TO SHOW SOME PCPN HOLDING
TOGETHER INTO AT LEAST OUR SOUTHWESTERN AREAS SO WILL ALLOW FOR
SOME LOW CHANCE POPS MAKING IT INTO AT LEAST OUR SOUTHWEST TOWARD
MIDNIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
ANY REMAINING PRECIPITATION ACROSS THE FAR NORTHERN PORTIONS OF
THE FA WILL TAPER OFF TUESDAY MORNING. A BRIEF LULL IN THE
PRECIPITATION IS EXPECTED. EXPECT SHOWERS AND THUNDERSTORMS TO
DEVELOP DURING THE AFTERNOON HOURS AND MOVE INTO NW AND NORTHERN
PORTIONS OF THE FA BY THE LATE AFTERNOON AND INTO THE EARLY
EVENING HOURS. THERE IS DECENT INSTABILITY ACROSS THE FA DURING
THE DAY ON TUESDAY. AS THESE STORMS DEVELOP AND MOVE INTO NORTHERN
PORTIONS OF THE FORECAST AREA ON TUESDAY SOME OF THE STORMS COULD
BE STRONG TO SEVERE WITH THE PRIMARY THREAT BEING DAMAGING WINDS.
THIS ACTIVITY WILL DECREASE TUESDAY NIGHT AND DRY CONDITIONS WILL
RETURN TO THE AREA.
WINDS WILL INCREASE ACROSS THE AREA FOR THE DAYTIME HOURS ON
TUESDAY WITH MODEL SOUNDINGS INDICATING SOME WIND GUSTS UPWARDS OF
30 MILES PER HOUR. WIND GUSTS WILL SLOWLY SUBSIDE TUESDAY NIGHT.
WARM SOUTHERLY FLOW WILL ALLOW FOR TEMPERATURES TO RISE INTO THE
80S ACROSS THE ENTIRE FORECAST AREA FOR TUESDAY. WITH SOUTHERLY
FLOW CONTINUING INTO TUESDAY NIGHT TEMPERATURES WILL ONLY DROP
DOWN INTO THE 60S.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
UPPER LEVEL RIDGING WILL CAP THE REGION LEADING TO DRY AND VERY WARM
CONDITIONS FOR THE MIDDLE PART OF THE WEEK. GUIDANCE IS TRENDING
TOWARDS A SOMEWHAT QUICKER SUPPRESSION OF THE RIDGE. SO IT APPEARS
THAT HEIGHTS WILL LOWER ENOUGH BY FRIDAY TO ALLOW FOR THE POTENTIAL
OF DIURNAL CONVECTION ESPECIALLY IN THE NORTHWEST PART OF THE
FORECAST AREA. EXPECT GREATER COVERAGE OF STORMS ON SATURDAY WITH
STILL SOME DIURNAL COMPONENT. BUT A SHORT WAVE MOVING THROUGH THE
GREAT LAKES WILL CAUSE A COLD FRONT TO MOVE TOWARDS THE AREA
SATURDAY NIGHT AND SUNDAY AND PUSH IT OFF TO THE EAST SUNDAY NIGHT.
THIS WILL BRING ADDITIONAL SHOWERS AND THUNDERSTORMS THROUGH THE
REGION FROM LATER SATURDAY NIGHT INTO SUNDAY EVENING. THERE ARE SOME
INDICATIONS THAT SHOWERS COULD LINGER INTO MONDAY WITH A SECONDARY
TROUGH. BUT PROBABILITY IS LOW AT THIS POINT. TEMPERATURES WILL FALL
BACK TO OR SLIGHTLY BELOW NORMAL FOR THE BEGINNING OF NEXT WEEK.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
SHOWERS AND THUNDERSTORMS CONTINUE NORTH OF THE TAF SITES ACROSS
THE SRN GREAT LAKES REGION...ALONG AND NORTH OF A WARM FRONT.
THE NORTHERN TAF SITES COULD SEE A WEAKENING SHOWER BUT CONDITIONS
ARE EXPECTED TO REMAIN VFR WITH CIGS IN THE MID LEVELS BETWEEN
8000 AND 11000 FEET AGL. HAVE COVERED THIS THREAT WITH A MENTION
OF VCSH. EXPECT A GENERAL LULL IN CONVECTIVE ACTIVITY DURG THE
EARLY MORNING HOURS. WITH HEATING AIRMASS WILL ONCE AGAIN
DESTABILIZE THROUGH THE AFTERNOON HOURS. THIS WILL LEAD TO SOME
ISOLATED TO SCATTERED THUNDERSTORM ACTIVITY MAINLY ACROSS THE NRN
TAF SITES. IN THE WARM AIRMASS A CAP SHOULD INHIBIT CONVECTIVE
DEVELOPMENT. WILL CONTINUE TO KEEP THE TAFS DRY AT THIS POINT WITH
THE BEST CHANCE OF THUNDERSTORMS NORTH OF INTERSTATE 70...CLOSER
TO THE WARM FRONT BOUNDARY. THE PRESSURE GRADIENT WILL TIGHTEN
TODAY WITH SW WINDS GUSTING UP TO 28 KTS THIS AFTN.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...NOVAK
NEAR TERM...JGL
SHORT TERM...NOVAK
LONG TERM...
AVIATION...AR
AREA FORECAST DISCUSSION
NWS TULSA OK
1207 PM CDT TUE MAY 28 2013
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
VFR CONDITIONS SHOULD PREVAIL THROUGH THE PERIOD. THERE IS A
CHANCE THAT ADDITIONAL MVFR CIGS COULD DEVELOP TOWARD SUNRISE AT
THE OK TERMINALS...BUT CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE A
CIG ATTM. WINDS WILL BE GUSTY THROUGH THE AFTERNOON...AND GUSTS
WILL REDEVELOP AT ALL TERMINALS BY MID TO LATE MORNING TOMORROW.
&&
.PREV DISCUSSION... /ISSUED 1049 AM CDT TUE MAY 28 2013/
..UPDATE...
DISCUSSION...
SHOWERS AND THUNDERSTORMS ACROSS FAR NORTHEAST OKLAHOMA AND PARTS
OF NORTHWEST ARKANSAS WILL CONTINUE TO MOVE OUT OF THE AREA BY THE
AFTERNOON HOURS. SOME CLOUDINESS WILL LIKELY PERSIST THROUGH THE
DAY...BUT AN OVERALL DECREASE IN CLOUD COVER WILL OCCUR TODAY.
WILL GO AHEAD AND LEAVE HIGH TEMPERATURES AS IS FOR NOW...DUE TO
THE CLOUD COVER. WIND GUSTS HAVE SO FAR REMAINED BELOW ADVISORY
THRESHOLD...SO WILL NOT ISSUE ANYTHING FOR THAT AT THIS TIME.
PREV DISCUSSION... /ISSUED 422 AM CDT TUE MAY 28 2013/
DISCUSSION...
UPPER LEVEL TROUGH CONTINUES TO ORGANIZE TO OUR WEST THIS MORNING
WITH PROFILER NETWORK ANALYZING A SWLY 55-65KT SOUTHWESTERLY LOW
LEVEL JET ORIENTED OVER EASTERN OKLAHOMA. CLUSTER OF ELEVATED
STORMS OVER CENTRAL MO SHOWING SIGNS OF BACK-BUILDING ALONG JET
AXIS TOWARD NW ARKANSAS. ALSO AN APPARENT WAVE EMBEDDED IN WSW
FLOW ALOFT TO OUR WEST. LOCAL MODEL AND HRRR LENDS SOME SUPPORT TO
NAM SOLUTION OF BREAKING OUT PRECIP ACROSS NE OKLAHOMA THIS
MORNING AND MAY NEED TO INCLUDE A SMALL CHANCE OF THUNDER FOR THE
MORNING PERIOD. AIRMASS SHOULD ONCE AGAIN BECOME STRONGLY CAPPED
THIS AFTERNOON WITH ANY LATER THUNDERSTORMS ASSOCIATED WITH DRY
LINE FAR TO OUR WEST.
WILL ONCE AGAIN SEE STRONG AND GUSTY SOUTH WINDS WITH A FEW GUSTS
APPROACHING 40 MPH IN NE OKLAHOMA...BUT MUCH LIKE YESTERDAY IT
APPEARS TOO MARGINAL FOR A WIND ADVISORY. MIXING MAY ALSO BE
HAMPERED A BIT BY CLOUD COVER MUCH OF THE DAY. SIMILAR CONDITIONS
EXPECTED WEDNESDAY.
UPPER TROUGH WILL BECOME MORE NEGATIVELY TILTED WEDNESDAY AS
STRONGER SHORTWAVE NOW MOVING ONSHORE SLIDES EAST. THIS WILL GIVE
DRY LINE STORMS TO OUR WEST WED AFTERNOON AND EVENING BETTER
SUPPORT TO ORGANIZE AND MOVE EAST OVERNIGHT INTO EASTERN OK AND
POSSIBLY FAR NW ARKANSAS. THIS SHOULD MOVE OUT EARLY ENOUGH TO
ALLOW ATMOSPHERE TO RECOVER THU AFTERNOON AND WITH UPPER JET IN
FAVORABLE POSITION...THIS PERIOD WILL OFFER GREATEST THREAT FOR
ORGANIZED SEVERE WEATHER ACROSS OUR AREA. FORECAST WIND PROFILES
LOOK FAVORABLE FOR ALL MODES OF SEVERE WEATHER.
COLD FRONT WILL EVENTUALLY PUSH THROUGH THE AREA LATE FRIDAY AND SATURDAY
WITH THUNDERSTORM CHANCES INCREASING ONCE AGAIN. DRIER AIRMASS
WILL MOVE IN FOR EARLY NEXT WEEK WITH A COUPLE OF PLEASANTLY COOL
NIGHTS AND WARM DAYS.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...22
LONG TERM....23
AVIATION...22
AREA FORECAST DISCUSSION
NWS TULSA OK
1049 AM CDT TUE MAY 28 2013
...UPDATE...
.DISCUSSION...
SHOWERS AND THUNDERSTORMS ACROSS FAR NORTHEAST OKLAHOMA AND PARTS
OF NORTHWEST ARKANSAS WILL CONTINUE TO MOVE OUT OF THE AREA BY THE
AFTERNOON HOURS. SOME CLOUDINESS WILL LIKELY PERSIST THROUGH THE
DAY...BUT AN OVERALL DECREASE IN CLOUD COVER WILL OCCUR TODAY.
WILL GO AHEAD AND LEAVE HIGH TEMPERATURES AS IS FOR NOW...DUE TO
THE CLOUD COVER. WIND GUSTS HAVE SO FAR REMAINED BELOW ADVISORY
THRESHOLD...SO WILL NOT ISSUE ANYTHING FOR THAT AT THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 422 AM CDT TUE MAY 28 2013/
DISCUSSION...
UPPER LEVEL TROUGH CONTINUES TO ORGANIZE TO OUR WEST THIS MORNING
WITH PROFILER NETWORK ANALYZING A SWLY 55-65KT SOUTHWESTERLY LOW
LEVEL JET ORIENTED OVER EASTERN OKLAHOMA. CLUSTER OF ELEVATED
STORMS OVER CENTRAL MO SHOWING SIGNS OF BACK-BUILDING ALONG JET
AXIS TOWARD NW ARKANSAS. ALSO AN APPARENT WAVE EMBEDDED IN WSW
FLOW ALOFT TO OUR WEST. LOCAL MODEL AND HRRR LENDS SOME SUPPORT TO
NAM SOLUTION OF BREAKING OUT PRECIP ACROSS NE OKLAHOMA THIS
MORNING AND MAY NEED TO INCLUDE A SMALL CHANCE OF THUNDER FOR THE
MORNING PERIOD. AIRMASS SHOULD ONCE AGAIN BECOME STRONGLY CAPPED
THIS AFTERNOON WITH ANY LATER THUNDERSTORMS ASSOCIATED WITH DRY
LINE FAR TO OUR WEST.
WILL ONCE AGAIN SEE STRONG AND GUSTY SOUTH WINDS WITH A FEW GUSTS
APPROACHING 40 MPH IN NE OKLAHOMA...BUT MUCH LIKE YESTERDAY IT
APPEARS TOO MARGINAL FOR A WIND ADVISORY. MIXING MAY ALSO BE
HAMPERED A BIT BY CLOUD COVER MUCH OF THE DAY. SIMILAR CONDITIONS
EXPECTED WEDNESDAY.
UPPER TROUGH WILL BECOME MORE NEGATIVELY TILTED WEDNESDAY AS
STRONGER SHORTWAVE NOW MOVING ONSHORE SLIDES EAST. THIS WILL GIVE
DRY LINE STORMS TO OUR WEST WED AFTERNOON AND EVENING BETTER
SUPPORT TO ORGANIZE AND MOVE EAST OVERNIGHT INTO EASTERN OK AND
POSSIBLY FAR NW ARKANSAS. THIS SHOULD MOVE OUT EARLY ENOUGH TO
ALLOW ATMOSPHERE TO RECOVER THU AFTERNOON AND WITH UPPER JET IN
FAVORABLE POSITION...THIS PERIOD WILL OFFER GREATEST THREAT FOR
ORGANIZED SEVERE WEATHER ACROSS OUR AREA. FORECAST WIND PROFILES
LOOK FAVORABLE FOR ALL MODES OF SEVERE WEATHER.
COLD FRONT WILL EVENTUALLY PUSH THROUGH THE AREA LATE FRIDAY AND SATURDAY
WITH THUNDERSTORM CHANCES INCREASING ONCE AGAIN. DRIER AIRMASS
WILL MOVE IN FOR EARLY NEXT WEEK WITH A COUPLE OF PLEASANTLY COOL
NIGHTS AND WARM DAYS.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...22
LONG TERM....23
AREA FORECAST DISCUSSION
NWS TULSA OK
422 AM CDT TUE MAY 28 2013
.DISCUSSION...
UPPER LEVEL TROUGH CONTINUES TO ORGANIZE TO OUR WEST THIS MORNING
WITH PROFILER NETWORK ANALYZING A SWLY 55-65KT SOUTHWESTERLY LOW
LEVEL JET ORIENTED OVER EASTERN OKLAHOMA. CLUSTER OF ELEVATED
STORMS OVER CENTRAL MO SHOWING SIGNS OF BACK-BUILDING ALONG JET
AXIS TOWARD NW ARKANSAS. ALSO AN APPARENT WAVE EMBEDDED IN WSW
FLOW ALOFT TO OUR WEST. LOCAL MODEL AND HRRR LENDS SOME SUPPORT TO
NAM SOLUTION OF BREAKING OUT PRECIP ACROSS NE OKLAHOMA THIS
MORNING AND MAY NEED TO INCLUDE A SMALL CHANCE OF THUNDER FOR THE
MORNING PERIOD. AIRMASS SHOULD ONCE AGAIN BECOME STRONGLY CAPPED
THIS AFTERNOON WITH ANY LATER THUNDERSTORMS ASSOCIATED WITH DRY
LINE FAR TO OUR WEST.
WILL ONCE AGAIN SEE STRONG AND GUSTY SOUTH WINDS WITH A FEW GUSTS
APPROACHING 40 MPH IN NE OKLAHOMA...BUT MUCH LIKE YESTERDAY IT
APPEARS TOO MARGINAL FOR A WIND ADVISORY. MIXING MAY ALSO BE
HAMPERED A BIT BY CLOUD COVER MUCH OF THE DAY. SIMILAR CONDITIONS
EXPECTED WEDNESDAY.
UPPER TROUGH WILL BECOME MORE NEGATIVELY TILTED WEDNESDAY AS
STRONGER SHORTWAVE NOW MOVING ONSHORE SLIDES EAST. THIS WILL GIVE
DRY LINE STORMS TO OUR WEST WED AFTERNOON AND EVENING BETTER
SUPPORT TO ORGANIZE AND MOVE EAST OVERNIGHT INTO EASTERN OK AND
POSSIBLY FAR NW ARKANSAS. THIS SHOULD MOVE OUT EARLY ENOUGH TO
ALLOW ATMOSPHERE TO RECOVER THU AFTERNOON AND WITH UPPER JET IN
FAVORABLE POSITION...THIS PERIOD WILL OFFER GREATEST THREAT FOR
ORGANIZED SEVERE WEATHER ACROSS OUR AREA. FORECAST WIND PROFILES
LOOK FAVORABLE FOR ALL MODES OF SEVERE WEATHER.
COLD FRONT WILL EVENTUALLY PUSH THROUGH THE AREA LATE FRIDAY AND SATURDAY
WITH THUNDERSTORM CHANCES INCREASING ONCE AGAIN. DRIER AIRMASS
WILL MOVE IN FOR EARLY NEXT WEEK WITH A COUPLE OF PLEASANTLY COOL
NIGHTS AND WARM DAYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 85 72 83 70 / 10 10 20 70
FSM 87 69 86 68 / 10 10 10 50
MLC 84 72 83 71 / 10 10 20 50
BVO 84 70 83 70 / 10 10 20 70
FYV 83 66 81 68 / 10 10 10 60
BYV 84 68 82 67 / 10 10 10 60
MKO 85 69 82 67 / 10 10 10 70
MIO 86 69 84 68 / 10 10 10 60
F10 83 71 82 69 / 10 10 20 60
HHW 84 69 83 69 / 10 10 20 40
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...30
LONG TERM....14
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
640 PM EDT WED MAY 29 2013
.SYNOPSIS...
WARMER AND MORE HUMID AIR WILL CONTINUE TO SPREAD ACROSS THE REGION
AND STAY WILL US INTO THE UPCOMING WEEKEND. AN UPPER AIR DISTURBANCE
CROSSING LAKE ERIE SHOULD FIRE OFF ONE OR TWO LINES OF SHOWERS AND
THUNDERSTORMS THIS AFTERNOON AND EVENING OVER MAINLY THE NORTHERN
THIRD OF PENNSYLVANIA. SOME OF THE STORMS MAY PRODUCE STRONG WIND
GUSTS AND HAIL. A STRENGTHENING UPPER LEVEL RIDGE WILL BUILD ALONG
THE MID ATLANTIC REGION THROUGH THE END OF THE WEEK...KEEPING VERY
WARM AND HUMID CONDITIONS IN THE FORECAST INTO THIS WEEKEND. A
RATHER STRONG COLD FRONT WILL MOVE EAST ACROSS THE COMMONWEALTH
SUNDAY...ACCOMPANIED BY SHOWERS AND SCATTERED THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 10 PM THIS EVENING/...
STILL A BROAD AREA OF MIXED LAYER CIN SITUATED ACROSS ALL OF THE WRN
MTNS OF PENN AT 1730Z WITH A RIBBON OF RELATIVELY HIGHER ML CAPE
AROUND 1500 J/KG DEVELOPING ACROSS THE ENTIRE SUSQ VALLEY.
MID/UPPER LEVEL SHORT WAVE MOVING QUICKLY EAST ACROSS LAKE ERIE AND
SOUTHERN ONTARIO /AND ABOVE A NE/SW RIBBON OF MDTLY STRONG LLVL
THETA-E CONVERGENCE OVER LAKE ERIE WILL LIKELY FIRE-UP SOME TSRA
JUST INLAND FROM THE SE SHORE OF LAKE ERIE DURING THE MID TO LATE
AFTERNOON HOURS.
LATEST 3 KM HRRR FORECAST REFLECTIVITY AND THE 4 KM NAM DIFFER A BIT
IN THEIR ULTIMATE TRACK OF A POTENTIAL FAST-MOVING LINE OF TSRA
/MCS/ THAT IS PROJECTED TO RACE ACROSS NRN PA AND SRN NEW LATER
TODAY. THE NAM INITIATES CONVECTION OVER THE NW MTNS INVOF KBFD AND
RAPIDLY PROPAGATES AN ORGANIZED MCS /WITH A DISTINCT...STRONG COLD
POOL HIGHLIGHTED BY SURFACE TEMPS FALLING SHARPLY INTO THE M/U 60S
ACROSS NORTH CENTRAL AND NORTHEASTERN PA LATE THIS AFTERNOON.
AT THIS STAGE IN THE GAME...BOTH MODELS ARE A BIT BEHIND THE CURVE
WITH RESPECT TO CONVECTIVE INITIATION...THANKS TO THE AFOREMENTIONED
WEAK CIN ACROSS THE WRN MTNS.
HIGH RES VISIBLE SATL IMAGERY SHOWS A QUICKLY DEVELOPING/DEEPENING
CU FIELD JUST A FEW NM SOUTH OF THE LAKE ERIE. THESE CU SHOULD
RAPIDLY GROW TO TSRA OVER THE NEXT 1-2 HOURS AS THE MID LEVEL CAP IS
BROKEN AND WARM/UNSTABLE AIR /WITH SURFACE-BASED LIFTED INDICES
AROUND -6/ IS ADVECTED NEWD.
WITH MODERATE WESTERLIES AND SOMEWHAT OF AN INVERTED-V SOUNDING
PRECEDING THIS LINE...DAMAGING WEST TO WNWRLY WIND GUSTS WILL BE
POSSIBLE ALONG WITH HAIL...AND SPC HAS PLACED NORTHEAST PORTIONS OF
CENTRAL PA IN SLIGHT RISK OUTLOOK FOR TODAY INTO TONIGHT.
AMPLIFYING THERMAL RIDGE EXTENDS INTO SOUTHERN PA THIS AFTERNOON.
+17C SHOULD NOSE INTO THE SOUTH CENTRAL MOUNTAINS BY 00Z
TONIGHT...WHICH SHOULD BE SUFFICIENT TO SUPPORT MAXES IN THE U80S
ACROSS THE SOUTH. THE NORTHERN AREAS SHOULD REACH THE LOWER 80S.
THESE HIGHS ARE 10 TO 15 DEGREES ABOVE NORMAL. IN ADDITION...THE
HUMIDITY WILL BE NOTICEABLE...AS DEWPOINTS RANGE FROM THE LOWER TO
MIDDLE 60S.
&&
.SHORT TERM /10 PM THIS EVENING THROUGH 6 PM THURSDAY/...
UPPER RIDGE WILL BUILD AND AMPLIFY TONIGHT AND THURSDAY...WITH RING
OF FIRE CONVECTION SHIFTING NORTH OF THE AREA AS A STRONG MID-LEVEL
CAP BUILDS AND POPS DECREASE AS A RESULT.
SCT CONVECTION IN THE FORM OF SOME POTENTIALLY STRONG TSRA THIS
EVENING...WILL BE MAINLY ACROSS THE NRN MTNS...AND OVER THE REGION
TO THE EAST OF KIPT AND KSEG UNTIL AROUND 05Z...AS THE TAIL END OF
THE UPPER SHORT WAVE /OR ASSOCIATED OUTFLOW BOUNDARIES FROM STORMS
ACROSS NY STATE/ PUSHES ACROSS THAT PART OF THE STATE.
PARTLY CLOUDY AND MILD CONDITIONS WILL FOLLOW FOR THE LATE NIGHT
HOURS WITH AREAS OF FOG FORMING...AND BECOMING LOCALLY DENSE DAYBREAK
/ESPECIALLY IN AREAS THAT RECEIVE SOME LATE DAY SHRA OR TSRA/.
MINS WILL RANGE FROM THE UPPER 50S NORTH TO THE LOWER TO MIDDLE 60S
SOUTH.
A FEW DEG C OF WARMING ALOFT AND DEEP-LAYER RIDGING BUILDING NORTH
INTO THE STATE WILL BRING A PARTLY TO MOSTLY SUNNY...AND VERY WARM
DAY THURSDAY WITH VERY LITTLE /IF ANY/ CHANCE FOR A LATE DAY SHOWER
OF TSRA. IT/S NOT OUT OF THE QUESTION TO SEE JUST A FEW...TERRAIN
INDUCED LOW-TOPPED TSRA FORM AFTER 19Z ESPECIALLY ACROSS THE LAUREL
AND SCENT MTNS.
850 MB TEMPS OF +17C TO +18C WILL SUPPORT HIGHS IN THE LOWER
90S ACROSS MUCH OF SOUTH CENTRAL AND SOUTHEAST PA...WITH MID TO
UPPER 80S ACROSS THE NORTH.
ANOTHER MILD AND SLIGHTLY MUGGY NIGHT IS IN STORE FOR THURSDAY NIGHT
WITH LIGHT WIND AND MIN TEMPS RANGING FROM AROUND 60F ACROSS THE NRN
AND WRN MTNS...TO THE LOWER AND MID 60S ELSEWHERE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
UPPER RIDGE EXPECTED TO BE IN PLACE AT THE BEGINNING OF THE LONG TERM
PERIOD WILL PERSIST INTO THE WEEKEND. RIDGE AXIS WILL BEGIN TO
SHIFT EAST AS AN UPPER TROF MOVING EAST FROM THE NORTHERN PLAINS
SWINGS THROUGH THE GREAT LAKES AND NEW ENGLAND THROUGH THE
REMAINDER OF THE PERIOD.
WITH THE UPPER RIDGE IN PLACE...THE LONG TERM PERIOD WILL BEGIN WITH
SEVERAL DAYS OF VERY WARM AND HUMID BUT GENERALLY PCPN FREE
WEATHER. SIGNIFICANT CHANCES FOR SHOWERS/TSTMS REMAIN CENTERED
AROUND LATE SATURDAY...MUCH OF SUNDAY AND INTO MONDAY WHEN THE
UPPER TROF AND ASSOCIATED COLD FRONT MOVE ACROSS THE STATE.
THE FIRST FULL WEEK OF JUNE LOOKS TO BE SIGNIFICANTLY COOLER THAN
THE FIRST COUPLE OF DAYS AS THE UPPER TROF DOMINATES THE REGION.
&&
.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
VFR NOTED AT ALL TAF SITES THIS AFTERNOON. SFC WARM FRONT HAS LIFTED
NORTH INTO SOUTHERN NEW YORK...WITH A 10-15KT SWRLY TO WESTERLY SFC
WIND PRESENT ACROSS CENTRAL PENN.
AN UPPER LEVEL DISTURBANCE LAKE ERIE AND WESTERN NEW YORK WILL BE
RESPONSIBLE FOR THE DEVELOPMENT OF SOME FAST MOVING SHOWERS AND
THUNDERSTORMS ACROSS MAINLY NRN PENN LATE TODAY AND EARLY TONIGHT.
A FEW OF THE STORMS COULD TRY TO PUSH SOUTH ACROSS THE MID SUSQ
VALLEY THIS EVENING TWD THE KSEG AND KMDT AREAS. EXPECT
BRIEF...MAINLY MVFR CONDITIONS WITH THESE SHOWERS AND STORMS.
THE MAIN PERIOD OF ADVERSE FLYING WEATHER WILL LIKELY BE BETWEEN
08-12Z THURSDAY...WHEN AREAS OF 1SM FOG /AND SOME LOCALLY DENSE WITH
VSBYS AOB 1/4SM/ WILL DEVELOP IN THE HUMID AIRMASS WITH LIGHT
WIND.
CONDITIONS QUICKLY IMPROVE TO WIDESPREAD VFR BETWEEN 13-14Z THURSDAY
AND STAY THAT WAY THROUGH AT LEAST EARLY THURSDAY NIGHT.
.OUTLOOK...
FRI AND SAT...MAINLY VFR. SOME RESTRICTIONS IN AM FOG AND HAZE
POSSIBLE. ISOLATED LATE DAY THUNDERSTORMS POSSIBLE ACROSS MAINLY THE
WESTERN HALF OF THE STATE SATURDAY.
SUN...VFR TO MVFR IN AREAS OF THUNDERSTORMS AS A COLD FRONT
APPROACHES FROM THE WEST.
MON...MORNING LOW CIGS AND VSBYS POSSIBLE IN AREAS OF FOG...THEN VFR
FOR THE LATE MORNING AND AFTERNOON.
&&
.EQUIPMENT...
NOAA WEATHER RADIO BROADCASTING ON A FREQUENCY OF 162.450 MHZ AND
SERVING WARREN COUNTY...ALONG WITH PORTIONS OF MCKEAN...ELK AND
FOREST COUNTIES...IS BACK IN OPERATION.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DEVOIR/LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...DEVOIR
LONG TERM...GARTNER
AVIATION...LAMBERT
EQUIPMENT...LAMBERT
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
210 PM EDT WED MAY 29 2013
.SYNOPSIS...
WARMER AND MORE HUMID AIR WILL CONTINUE TO SPREAD ACROSS THE REGION
AND STAY WILL US INTO THE UPCOMING WEEKEND. AN UPPER AIR DISTURBANCE
CROSSING LAKE ERIE SHOULD FIRE OFF ONE OR TWO LINES OF SHOWERS AND
THUNDERSTORMS THIS AFTERNOON AND EVENING OVER MAINLY THE NORTHERN
THIRD OF PENNSYLVANIA. SOME OF THE STORMS MAY PRODUCE STRONG WIND
GUSTS AND HAIL. A STRENGTHENING UPPER LEVEL RIDGE WILL BUILD ALONG
THE MID ATLANTIC REGION THROUGH THE END OF THE WEEK...KEEPING VERY
WARM AND HUMID CONDITIONS IN THE FORECAST INTO THIS WEEKEND. A
RATHER STRONG COLD FRONT WILL MOVE EAST ACROSS THE COMMONWEALTH
SUNDAY...ACCOMPANIED BY SHOWERS AND SCATTERED THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 10 PM THIS EVENING/...
STILL A BROAD AREA OF MIXED LAYER CIN SITUATED ACROSS ALL OF THE WRN
MTNS OF PENN AT 1730Z WITH A RIBBON OF RELATIVELY HIGHER ML CAPE
AROUND 1500 J/KG DEVELOPING ACROSS THE ENTIRE SUSQ VALLEY.
MID/UPPER LEVEL SHORT WAVE MOVING QUICKLY EAST ACROSS LAKE ERIE AND
SOUTHERN ONTARIO /AND ABOVE A NE/SW RIBBON OF MDTLY STRONG LLVL
THETA-E CONVERGENCE OVER LAKE ERIE WILL LIKELY FIRE-UP SOME TSRA
JUST INLAND FROM THE SE SHORE OF LAKE ERIE DURING THE MID TO LATE
AFTERNOON HOURS.
LATEST 3 KM HRRR FORECAST REFLECTIVITY AND THE 4 KM NAM DIFFER A BIT
IN THEIR ULTIMATE TRACK OF A POTENTIAL FAST-MOVING LINE OF TSRA
/MCS/ THAT IS PROJECTED TO RACE ACROSS NRN PA AND SRN NEW LATER
TODAY. THE NAM INITIATES CONVECTION OVER THE NW MTNS INVOF KBFD AND
RAPIDLY PROPAGATES AN ORGANIZED MCS /WITH A DISTINCT...STRONG COLD
POOL HIGHLIGHTED BY SURFACE TEMPS FALLING SHARPLY INTO THE M/U 60S
ACROSS NORTH CENTRAL AND NORTHEASTERN PA LATE THIS AFTERNOON.
AT THIS STAGE IN THE GAME...BOTH MODELS ARE A BIT BEHIND THE CURVE
WITH RESPECT TO CONVECTIVE INITIATION...THANKS TO THE AFOREMENTIONED
WEAK CIN ACROSS THE WRN MTNS.
HIGH RES VISIBLE SATL IMAGERY SHOWS A QUICKLY DEVELOPING/DEEPENING
CU FIELD JUST A FEW NM SOUTH OF THE LAKE ERIE. THESE CU SHOULD
RAPIDLY GROW TO TSRA OVER THE NEXT 1-2 HOURS AS THE MID LEVEL CAP IS
BROKEN AND WARM/UNSTABLE AIR /WITH SURFACE-BASED LIFTED INDICES
AROUND -6/ IS ADVECTED NEWD.
WITH MODERATE WESTERLIES AND SOMEWHAT OF AN INVERTED-V SOUNDING
PRECEDING THIS LINE...DAMAGING WEST TO WNWRLY WIND GUSTS WILL BE
POSSIBLE ALONG WITH HAIL...AND SPC HAS PLACED NORTHEAST PORTIONS OF
CENTRAL PA IN SLIGHT RISK OUTLOOK FOR TODAY INTO TONIGHT.
AMPLIFYING THERMAL RIDGE EXTENDS INTO SOUTHERN PA THIS AFTERNOON.
+17C SHOULD NOSE INTO THE SOUTH CENTRAL MOUNTAINS BY 00Z
TONIGHT...WHICH SHOULD BE SUFFICIENT TO SUPPORT MAXES IN THE U80S
ACROSS THE SOUTH. THE NORTHERN AREAS SHOULD REACH THE LOWER 80S.
THESE HIGHS ARE 10 TO 15 DEGREES ABOVE NORMAL. IN ADDITION...THE
HUMIDITY WILL BE NOTICEABLE...AS DEWPOINTS RANGE FROM THE LOWER TO
MIDDLE 60S.
&&
.SHORT TERM /10 PM THIS EVENING THROUGH THURSDAY NIGHT/...
UPPER RIDGE WILL BUILD AND AMPLIFY TONIGHT AND THURSDAY...WITH RING
OF FIRE CONVECTION SHIFTING NORTH OF THE AREA AS A STRONG MID-LEVEL
CAP BUILDS AND POPS DECREASE AS A RESULT.
SCT CONVECTION IN THE FORM OF SOME POTENTIALLY STRONG TSRA THIS
EVENING...WILL BE MAINLY ACROSS THE NRN MTNS...AND OVER THE REGION
TO THE EAST OF KIPT AND KSEG UNTIL AROUND 05Z...AS THE TAIL END OF
THE UPPER SHORT WAVE /OR ASSOCIATED OUTFLOW BOUNDARIES FROM STORMS
ACROSS NY STATE/ PUSHES ACROSS THAT PART OF THE STATE.
PARTLY CLOUDY AND MILD CONDITIONS WILL FOLLOW FOR THE LATE NIGHT
HOURS WITH AREAS OF FOG FORMING...AND BECOMING LOCALLY DENSE DAYBREAK
/ESPECIALLY IN AREAS THAT RECEIVE SOME LATE DAY SHRA OR TSRA/.
MINS WILL RANGE FROM THE UPPER 50S NORTH TO THE LOWER TO MIDDLE 60S
SOUTH.
A FEW DEG C OF WARMING ALOFT AND DEEP-LAYER RIDGING BUILDING NORTH
INTO THE STATE WILL BRING A PARTLY TO MOSTLY SUNNY...AND VERY WARM
DAY THURSDAY WITH VERY LITTLE /IF ANY/ CHANCE FOR A LATE DAY SHOWER
OF TSRA. IT/S NOT OUT OF THE QUESTION TO SEE JUST A FEW...TERRAIN
INDUCED LOW-TOPPED TSRA FORM AFTER 19Z ESPECIALLY ACROSS THE LAUREL
AND SCENT MTNS.
850 MB TEMPS OF +17C TO +18C WILL SUPPORT HIGHS IN THE LOWER
90S ACROSS MUCH OF SOUTH CENTRAL AND SOUTHEAST PA...WITH MID TO
UPPER 80S ACROSS THE NORTH.
ANOTHER MILD AND SLIGHTLY MUGGY NIGHT IS IN STORE FOR THURSDAY NIGHT
WITH LIGHT WIND AND MIN TEMPS RANGING FROM AROUND 60F ACROSS THE NRN
AND WRN MTNS...TO THE LOWER AND MID 60S ELSEWHERE.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AMPLIFIED UPPER RIDGE WILL REMAIN ALONG THE EASTERN SEABOARD
DURING THE PERIOD AS AN UPPER TROF CLOSES OFF/MOVES EASTWARD
ACROSS THE NORTHERN PLAINS AND INTO THE WRN GREAT LAKES. THIS WILL
BRING ANOTHER WARM SPELL FOR MUCH OF THE EAST AS WE HEAD INTO THE
BEGINNING OF JUNE. THE LONG TERM PERIOD WILL BEGIN WITH SEVERAL
DAYS OF MAINLY DRY WEATHER WITH LITTLE IN THE WAY OF LARGE SCALE
FORCING APPARENT.
SRLY/SWRLY SFC WINDS WILL LEAD TO INCREASING SFC MOISTURE AND
INSTABILITY...BUT SIGNIFICANT CHANCES FOR SHOWERS/TSTMS WILL HOLD
OFF TIL LATER SATURDAY AND ESPECIALLY SUNDAY AND MONDAY WHEN A
FRONT MOVES THROUGH THE UPPER FLOW AND INTO PA.
A COOL DOWN FOR THE FIRST FULL WEEK OF JUNE MAY THEN BE IN THE
OFFING FOR THE NORTHEAST...AS UPPER FLOW BECOMES QUITE TROFFY
LOOKING IN SEVERAL OF THE LONG RANGE MODELS.
&&
.AVIATION /18Z WEDNESDAY THROUGH SUNDAY/...
VFR NOTED AT ALL TAF SITES THIS AFTERNOON. SFC WARM FRONT HAS LIFTED
NORTH INTO SOUTHERN NEW YORK...WITH A 10-15KT SWRLY TO WESTERLY SFC
WIND PRESENT ACROSS CENTRAL PENN.
AN UPPER LEVEL DISTURBANCE LAKE ERIE AND WESTERN NEW YORK WILL BE
RESPONSIBLE FOR THE DEVELOPMENT OF SOME FAST MOVING SHOWERS AND
THUNDERSTORMS ACROSS MAINLY NRN PENN LATE TODAY AND EARLY TONIGHT.
A FEW OF THE STORMS COULD TRY TO PUSH SOUTH ACROSS THE MID SUSQ
VALLEY THIS EVENING TWD THE KSEG AND KMDT AREAS. EXPECT
BRIEF...MAINLY MVFR CONDITIONS WITH THESE SHOWERS AND STORMS.
THE MAIN PERIOD OF ADVERSE FLYING WEATHER WILL LIKELY BE BETWEEN
08-12Z THURSDAY...WHEN AREAS OF 1SM FOG /AND SOME LOCALLY DENSE WITH
VSBYS AOB 1/4SM/ WILL DEVELOP IN THE HUMID AIRMASS WITH LIGHT
WIND.
CONDITIONS QUICKLY IMPROVE TO WIDESPREAD VFR BETWEEN 13-14Z THURSDAY
AND STAY THAT WAY THROUGH AT LEAST EARLY THURSDAY NIGHT.
.OUTLOOK...
FRI AND SAT...MAINLY VFR. SOME RESTRICTIONS IN AM FOG AND HAZE
POSSIBLE. ISOLATED LATE DAY THUNDERSTORMS POSSIBLE ACROSS MAINLY THE
WESTERN HALF OF THE STATE SATURDAY.
SUN...VFR TO MVFR IN AREAS OF THUNDERSTORMS AS A COLD FRONT
APPROACHES FROM THE WEST.
MON...MORNING LOW CIGS AND VSBYS POSSIBLE IN AREAS OF FOG...THEN VFR
FOR THE LATE MORNING AND AFTERNOON.
&&
.EQUIPMENT...
NOAA WEATHER RADIO BROADCASTING ON A FREQUENCY OF 162.450 MHZ AND
SERVING WARREN COUNTY...ALONG WITH PORTIONS OF MCKEAN...ELK AND
FOREST COUNTIES...IS BACK IN OPERATION.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...GARTNER
AVIATION...LAMBERT
EQUIPMENT...LAMBERT
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
347 PM CDT TUE MAY 28 2013
.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...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
PREVAILING VFR CONDITIONS ARE EXPECTED THROUGH THE VALID TAF
PERIOD FOR THE TERMINALS OF KPIR/KMBG. SHOWERS AND THUNDERSTORMS
WILL BE POSSIBLE BETWEEN 02-06Z FOR KPIR. CONDITIONS MAY FALL TO
MVFR RANGE UNDER STRONGER STORMS. IFR/MVFR CIGS OVER THE KABR/KATY
TERMINALS SHOULD LIFT TO VFR RANGE BY MID AFTERNOON AND MAINTAIN
VFR STATUS THROUGH THE REST OF THE TAF PERIOD. THAT SAID...DUE TO
AN ABUNDANCE OF LOW LEVEL MOISTURE...IFR CONDITIONS ARE POSSIBLE
FOR THE KATY TERMINAL TONIGHT.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
SHORT TERM...MOHR
LONG TERM...SD
AVIATION...SD
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
119 PM CDT TUE MAY 28 2013
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 445 AM CDT TUE MAY 28 2013
REMNANTS OF OVERNIGHT CONVECTION MOVING THROUGH THE CWA THIS
MORNING...WITH MCV TRACKING ALONG THE MISSOURI RIVER. MESOANALYSIS
SHOWS VERY LITTLE IN THE WAY OF MUCAPE OVER OUR CWA...AND THUS AS
EXPECTED THE AREA OF RAIN CONTINUES TO WEAKEN. EXPECT THIS TREND TO
CONTINUE THROUGH THE MORNING. ANOTHER MAINLY DRY DAY IS THUS
EXPECTED...WITH LARGE SCALE SUBSIDENCE OVERHEAD. CONCERNED ABOUT
LOW STRATUS AND FOG LINGERING LONGER THAN PREVIOUSLY EXPECTED
THOUGH. FLOW BECOMES PRETTY WEAK TODAY...WITH NOT MUCH OF A PUSH OF
LOW LEVEL DRY AIR. THUS STRATUS SHOULD LINGER THROUGH THE
MORNING...WITH SLOW CLEARING FROM WEST TO EAST THIS AFTERNOON. WENT
AHEAD AND LOWERED HIGHS SEVERAL DEGREES TODAY...ESPECIALLY EAST OF
THE JAMES RIVER. THESE HIGHS ARE MORE IN LINE WITH SOME OF THE NEWER
GUIDANCE SUCH AS THE HRRR AND 4 KM NAM. LOOKING AT READINGS AROUND
70 SOUTHWEST MINNESOTA TO THE MID AND UPPER 70S ALONG THE MISSOURI
RIVER. DAY SHIFT WILL HAVE TO MONITOR TRENDS...AS ADJUSTMENTS UP OR
DOWN AREA LIKELY DEPENDING ON CLOUD COVER EVOLUTION...THUS ANOTHER
LOW CONFIDENCE TEMPERATURE FORECAST.
UNSETTLED WEATHER RETURNS TONIGHT INTO THURSDAY. LOW LEVEL JET
INCREASES AGAIN TONIGHT...ADVECTING IN RICH THETAE AIR AND HIGH
PWATS. MEANWHILE IT SEEMS LIKELY THAT CONVECTION WILL FIRE THIS
AFTERNOON ACROSS THE NEBRASKA PANHANDLE AND WESTERN SOUTH DAKOTA AS
ANOTHER WAVE BEGINS TO EJECT OUT OF THE ROCKIES...AND THIS EVOLUTION
IS SUPPORTED BY ALMOST ALL HI RES GUIDANCE. THIS AREA OF CONVECTION
SHOULD WEAKEN AS IT APPROACHES OUR AREA...AS DESPITE THE THETAE
ADVECTION...WE DRY OUT ENOUGH TODAY THAT WE DONT QUITE COMPLETELY
RECOVER IN TIME. HOWEVER MAY SEE THE LINE OF STORMS MAKE IT INTO OUR
FAR WESTERN COUNTIES AFTER 03Z BEFORE IT DOES DISSIPATE...AND THUS
CAN NOT RULE OUT AN ISOLATED SEVERE WIND GUST WITH THAT ACTIVITY.
EVENTUALLY THE CONTINUED THETAE ADVECTION BECOMES ENOUGH TO SATURATE
US ENOUGH AND DEVELOP ELEVATED INSTABILITY. THUS THOUGHT IS SHOWERS
AND STORMS START BECOMING MORE NUMEROUS BY EARLY WEDNESDAY MORNING
AND THROUGH THE DAY. NOT SEEING MUCH TOO MUCH OF A SEVERE THREAT
WITH THIS ACTIVITY AS SOUNDINGS EXHIBIT MORE OF A HEAVY RAIN
SATURATED THIN CAPE PROFILE. HOWEVER WIND FIELDS ARE STRONGER...THUS
A FEW MARGINAL SEVERE STORMS ARE POSSIBLE WITH THIS ACTIVITY ANYTIME
WEDNESDAY. TOUGH TO PINPOINT EXACTLY WHERE THE HEAVIEST OF THE RAIN
ENDS UP GOING. BUT HI RES MODEL SOLUTIONS SEEM TO FAVOR MUCH OF THE
HEAVIER ACTIVITY WEDNESDAY ALONG AND EAST OF INTERSTATE 29...WITH
CONVECTION CONTINUOUSLY DEVELOPING ACROSS CENTRAL OR EASTERN
NEBRASKA AND MOVING NORTH NORTHEAST WITH THE MEAN WIND. GIVEN THE
TRAINING POTENTIAL AND HIGH PWATS...WEDNESDAY LOOKS TO BE A DAY WITH
AN ELEVATED FLOODING POTENTIAL.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 445 AM CDT TUE MAY 28 2013
WE MAY SEE A BREAK FOR A PERIOD LATER WEDNESDAY AFTERNOON INTO THE
EVENING AS THE TRAINING WAA CONVECTION SHIFTS EAST OF THE CWA.
HOWEVER ATTENTION THEN TURNS YO OUR WEST AS THE MAIN WAVE MOVES INTO
THE PLAINS. A LARGE AREA OF THUNDERSTORMS SHOULD FIRE ACROSS THE
WESTERN PLAINS WITH THIS WAVE...AND THEN MOVE INTO OUR CWA ANYTIME
FROM THE EVENING INTO THE OVERNIGHT. DUE TO CONSIDERABLE CLOUD COVER
INSTABILITY MAY NOT BE TOO HIGH...BUT WIND FIELDS SHOULD BE STRONG
ENOUGH TI SUPPORT ORGANIZED CONVECTION. THUS THINKING OUR GREATEST
SEVERE THREAT MAY END UP BEING WITH THIS ACTIVITY WEDNESDAY EVENING
OR NIGHT. A FEW SUPERCELLS POSSIBLE IN OUR WEST...BUT TIMING
SUGGESTS THAT THE CONVECTION WOULD PROBABLY BE LINEAR BY THE TIME IT
IMPACTS MOST OF OUR CWA...WITH STRONG WINDS THE GREATEST THREAT.
GIVEN THE POTENTIAL OF HEAVY RAIN EARLIER WEDNESDAY...ANY ADDITIONAL
RAIN WOULD ALSO ENHANCE THE FLOODING POTENTIAL.
MODELS CONTINUE TO SPEED UP THE MOVEMENT OF THE WAVE. THUS BY
THURSDAY THE GREATEST THUNDERSTORM THREAT SHOULD BE EAST OF
INTERSTATE 29...AND DURING THE FIRST PORTION OF THE DAY. THUS SEVERE
THREAT ON THURSDAY SHOULD END UP SOUTH AND EAST OF OUR CWA. BY LATER
THURSDAY AFTERNOON INTO THE OVERNIGHT THERE MAY NOT BE MUCH GOING ON
ACROSS OUR AREA. GOING WITH HIGHS IN THE 70S BOTH WEDNESDAY AND
THURSDAY...BUT THIS AGAIN DEPENDENT ON CLOUD COVER. AREAS THAT SEE
SUN COULD REACH THE 80S BOTH DAYS...WHILE 60S ARE A POSSIBILITY
WHERE CLOUDS HOLD TOUGH.
THE PERSISTENT UPPER LOW OVER THE WESTERN UNITED STATES FINALLY
LIFTS NORTHEASTWARD TOWARD ND AND MN LATE THIS WEEK AND THROUGH THE
WEEKEND. THIS MEANS QUIETER WEATHER FOR OUR AREA. ALTHOUGH ONE
CANNOT RULE OUT A FEW SHOWERS OR ISOLATED THUNDERSTORMS IN OUR
FORECAST AREA FRIDAY AND SATURDAY...THE CHANCES OF ANY ONE LOCATION
GETTING A WETTING RAIN IS FAIRLY REMOTE. DRY WEATHER LOOKS TO
PREVAIL ON SUNDAY AND MONDAY. IN RESPONSE TO THE UPPER LOW LIFTING
CLOSER TO THE CANADIAN BORDER...COOL SURFACE HIGH PRESSURE WILL THEN
FILTER DOWN PROMISING MUCH BELOW NORMAL TEMPERATURES FOR THE
WEEKEND. ON FRIDAY AND MONDAY...70S SHOULD BE MORE WIDESPREAD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 114 PM CDT TUE MAY 28 2013
MVFR CEILINGS QUICKLY ADVECTING EAST EARLY THIS AFTERNOON AND
EXPECT THIS TREND TO CONTINUE THROUGH THE EVENING. VFR CONDITIONS
SHOULD PREVAIL MUCH OF THE NIGHT BUT A CLUSTER OF THUNDERSTORMS
SHOULD MOVE FROM THE WESTERN HIGH PLAINS INTO THE AREA AFTER ABOUT
08Z. AHEAD OF THIS CLUSTER ADDITIONAL THUNDERSTORMS MAY DEVELOP
AROUND THE MISSOURI RIVER VALLEY AND ADVECT NORTHWARD WEDNESDAY
MORNING. THE BETTER CHANCE FOR THUNDERSTORMS WILL LIKELY BE FROM
ABOUT 11Z THROUGH 18Z.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHENARD
LONG TERM...CHENARD/MJF
AVIATION...08
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
634 AM CDT TUE MAY 28 2013
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 445 AM CDT TUE MAY 28 2013
REMNANTS OF OVERNIGHT CONVECTION MOVING THROUGH THE CWA THIS
MORNING...WITH MCV TRACKING ALONG THE MISSOURI RIVER. MESOANALYSIS
SHOWS VERY LITTLE IN THE WAY OF MUCAPE OVER OUR CWA...AND THUS AS
EXPECTED THE AREA OF RAIN CONTINUES TO WEAKEN. EXPECT THIS TREND TO
CONTINUE THROUGH THE MORNING. ANOTHER MAINLY DRY DAY IS THUS
EXPECTED...WITH LARGE SCALE SUBSIDENCE OVERHEAD. CONCERNED ABOUT
LOW STRATUS AND FOG LINGERING LONGER THAN PREVIOUSLY EXPECTED
THOUGH. FLOW BECOMES PRETTY WEAK TODAY...WITH NOT MUCH OF A PUSH OF
LOW LEVEL DRY AIR. THUS STRATUS SHOULD LINGER THROUGH THE
MORNING...WITH SLOW CLEARING FROM WEST TO EAST THIS AFTERNOON. WENT
AHEAD AND LOWERED HIGHS SEVERAL DEGREES TODAY...ESPECIALLY EAST OF
THE JAMES RIVER. THESE HIGHS ARE MORE IN LINE WITH SOME OF THE NEWER
GUIDANCE SUCH AS THE HRRR AND 4 KM NAM. LOOKING AT READINGS AROUND
70 SOUTHWEST MINNESOTA TO THE MID AND UPPER 70S ALONG THE MISSOURI
RIVER. DAY SHIFT WILL HAVE TO MONITOR TRENDS...AS ADJUSTMENTS UP OR
DOWN AREA LIKELY DEPENDING ON CLOUD COVER EVOLUTION...THUS ANOTHER
LOW CONFIDENCE TEMPERATURE FORECAST.
UNSETTLED WEATHER RETURNS TONIGHT INTO THURSDAY. LOW LEVEL JET
INCREASES AGAIN TONIGHT...ADVECTING IN RICH THETAE AIR AND HIGH
PWATS. MEANWHILE IT SEEMS LIKELY THAT CONVECTION WILL FIRE THIS
AFTERNOON ACROSS THE NEBRASKA PANHANDLE AND WESTERN SOUTH DAKOTA AS
ANOTHER WAVE BEGINS TO EJECT OUT OF THE ROCKIES...AND THIS EVOLUTION
IS SUPPORTED BY ALMOST ALL HI RES GUIDANCE. THIS AREA OF CONVECTION
SHOULD WEAKEN AS IT APPROACHES OUR AREA...AS DESPITE THE THETAE
ADVECTION...WE DRY OUT ENOUGH TODAY THAT WE DONT QUITE COMPLETELY
RECOVER IN TIME. HOWEVER MAY SEE THE LINE OF STORMS MAKE IT INTO OUR
FAR WESTERN COUNTIES AFTER 03Z BEFORE IT DOES DISSIPATE...AND THUS
CAN NOT RULE OUT AN ISOLATED SEVERE WIND GUST WITH THAT ACTIVITY.
EVENTUALLY THE CONTINUED THETAE ADVECTION BECOMES ENOUGH TO SATURATE
US ENOUGH AND DEVELOP ELEVATED INSTABILITY. THUS THOUGHT IS SHOWERS
AND STORMS START BECOMING MORE NUMEROUS BY EARLY WEDNESDAY MORNING
AND THROUGH THE DAY. NOT SEEING MUCH TOO MUCH OF A SEVERE THREAT
WITH THIS ACTIVITY AS SOUNDINGS EXHIBIT MORE OF A HEAVY RAIN
SATURATED THIN CAPE PROFILE. HOWEVER WIND FIELDS ARE STRONGER...THUS
A FEW MARGINAL SEVERE STORMS ARE POSSIBLE WITH THIS ACTIVITY ANYTIME
WEDNESDAY. TOUGH TO PINPOINT EXACTLY WHERE THE HEAVIEST OF THE RAIN
ENDS UP GOING. BUT HI RES MODEL SOLUTIONS SEEM TO FAVOR MUCH OF THE
HEAVIER ACTIVITY WEDNESDAY ALONG AND EAST OF INTERSTATE 29...WITH
CONVECTION CONTINUOUSLY DEVELOPING ACROSS CENTRAL OR EASTERN
NEBRASKA AND MOVING NORTH NORTHEAST WITH THE MEAN WIND. GIVEN THE
TRAINING POTENTIAL AND HIGH PWATS...WEDNESDAY LOOKS TO BE A DAY WITH
AN ELEVATED FLOODING POTENTIAL.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 445 AM CDT TUE MAY 28 2013
WE MAY SEE A BREAK FOR A PERIOD LATER WEDNESDAY AFTERNOON INTO THE
EVENING AS THE TRAINING WAA CONVECTION SHIFTS EAST OF THE CWA.
HOWEVER ATTENTION THEN TURNS YO OUR WEST AS THE MAIN WAVE MOVES INTO
THE PLAINS. A LARGE AREA OF THUNDERSTORMS SHOULD FIRE ACROSS THE
WESTERN PLAINS WITH THIS WAVE...AND THEN MOVE INTO OUR CWA ANYTIME
FROM THE EVENING INTO THE OVERNIGHT. DUE TO CONSIDERABLE CLOUD COVER
INSTABILITY MAY NOT BE TOO HIGH...BUT WIND FIELDS SHOULD BE STRONG
ENOUGH TI SUPPORT ORGANIZED CONVECTION. THUS THINKING OUR GREATEST
SEVERE THREAT MAY END UP BEING WITH THIS ACTIVITY WEDNESDAY EVENING
OR NIGHT. A FEW SUPERCELLS POSSIBLE IN OUR WEST...BUT TIMING
SUGGESTS THAT THE CONVECTION WOULD PROBABLY BE LINEAR BY THE TIME IT
IMPACTS MOST OF OUR CWA...WITH STRONG WINDS THE GREATEST THREAT.
GIVEN THE POTENTIAL OF HEAVY RAIN EARLIER WEDNESDAY...ANY ADDITIONAL
RAIN WOULD ALSO ENHANCE THE FLOODING POTENTIAL.
MODELS CONTINUE TO SPEED UP THE MOVEMENT OF THE WAVE. THUS BY
THURSDAY THE GREATEST THUNDERSTORM THREAT SHOULD BE EAST OF
INTERSTATE 29...AND DURING THE FIRST PORTION OF THE DAY. THUS SEVERE
THREAT ON THURSDAY SHOULD END UP SOUTH AND EAST OF OUR CWA. BY LATER
THURSDAY AFTERNOON INTO THE OVERNIGHT THERE MAY NOT BE MUCH GOING ON
ACROSS OUR AREA. GOING WITH HIGHS IN THE 70S BOTH WEDNESDAY AND
THURSDAY...BUT THIS AGAIN DEPENDENT ON CLOUD COVER. AREAS THAT SEE
SUN COULD REACH THE 80S BOTH DAYS...WHILE 60S ARE A POSSIBILITY
WHERE CLOUDS HOLD TOUGH. /
THE PERSISTENT UPPER LOW OVER THE WESTERN UNITED STATES FINALLY
LIFTS NORTHEASTWARD TOWARD ND AND MN LATE THIS WEEK AND THROUGH THE
WEEKEND. THIS MEANS QUIETER WEATHER FOR OUR AREA. ALTHOUGH ONE
CANNOT RULE OUT A FEW SHOWERS OR ISOLATED THUNDERSTORMS IN OUR
FORECAST AREA FRIDAY AND SATURDAY...THE CHANCES OF ANY ONE LOCATION
GETTING A WETTING RAIN IS FAIRLY REMOTE. DRY WEATHER LOOKS TO
PREVAIL ON SUNDAY AND MONDAY. IN RESPONSE TO THE UPPER LOW LIFTING
CLOSER TO THE CANADIAN BORDER...COOL SURFACE HIGH PRESSURE WILL THEN
FILTER DOWN PROMISING MUCH BELOW NORMAL TEMPERATURES FOR THE
WEEKEND. ON FRIDAY AND MONDAY...70S SHOULD BE MORE WIDESPREAD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 633 AM CDT TUE MAY 28 2013
WIDESPREAD LIFR TO VLIFR CONDITIONS EXISTS EARLY TODAY ALONG AND
EAST OF INTERSTATE 29. CURRENTLY JUST BEFORE 12Z...KSUX IS SHOWING
VFR CONDITIONS. HOWEVER WHAT WIND THEY HAVE APPEARS TO BE GOING
EASTERLY AND THE CITY WEBCAMS LOOK VERY SOUPY. THEREFORE AM
CONCERNED THAT THE LIFR CONDITIONS WILL BEGIN TO ADVECT INTO THAT
LOCATION SHORTLY. SO HEDGED SOME STRATUS IN THERE BEGINNING AT
14Z...AND WILL MONITOR CLOSELY FOR ARRIVAL OR LACK OF ARRIVAL OF
THESE POOR CONDITIONS. SIMILARLY AT KHON...THEY ARE VFR. THEIR
WEBCAM CONFIRMS SOME PRETTY SOLID VFR AT THE MOMENT. BUT WITH
MITCHELL AND BROOKING SD SEEING LIFR CEILINGS...AM ALSO A BIT
WORRIED THAT KHON LATER THIS MORNING COULD SEE AT LEAST SOME
BROKEN CEILINGS IN THE IFR TO LOWER MVFR CATEGORY. KFSD IS SOLIDLY
LIFR. VARIOUS MODELS POINT TO A CLEARING TREND THIS AFTERNOON WITH
A SCOURING OUT OF THE STRATUS. THEREFORE TRENDED THE TAF SITES
TOWARD VFR THIS AFTERNOON AND EVENING. WATCH FOR MORE THUNDERSTORMS
TO DEVELOP LATE TONIGHT ALONG AND SOUTH OF INTERSTATE 90.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR MNZ071-072-
080-081-089-090-097-098.
IA...DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR IAZ001>003-
012>014-021-022.
NE...NONE.
&&
$$
SHORT TERM...CHENARD
LONG TERM...CHENARD/MJF
AVIATION...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
448 AM CDT TUE MAY 28 2013
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 445 AM CDT TUE MAY 28 2013
REMNANTS OF OVERNIGHT CONVECTION MOVING THROUGH THE CWA THIS
MORNING...WITH MCV TRACKING ALONG THE MISSOURI RIVER. MESOANALYSIS
SHOWS VERY LITTLE IN THE WAY OF MUCAPE OVER OUR CWA...AND THUS AS
EXPECTED THE AREA OF RAIN CONTINUES TO WEAKEN. EXPECT THIS TREND TO
CONTINUE THROUGH THE MORNING. ANOTHER MAINLY DRY DAY IS THUS
EXPECTED...WITH LARGE SCALE SUBSIDENCE OVERHEAD. CONCERNED ABOUT
LOW STRATUS AND FOG LINGERING LONGER THAN PREVIOUSLY EXPECTED
THOUGH. FLOW BECOMES PRETTY WEAK TODAY...WITH NOT MUCH OF A PUSH OF
LOW LEVEL DRY AIR. THUS STRATUS SHOULD LINGER THROUGH THE
MORNING...WITH SLOW CLEARING FROM WEST TO EAST THIS AFTERNOON. WENT
AHEAD AND LOWERED HIGHS SEVERAL DEGREES TODAY...ESPECIALLY EAST OF
THE JAMES RIVER. THESE HIGHS ARE MORE IN LINE WITH SOME OF THE NEWER
GUIDANCE SUCH AS THE HRRR AND 4 KM NAM. LOOKING AT READINGS AROUND
70 SOUTHWEST MINNESOTA TO THE MID AND UPPER 70S ALONG THE MISSOURI
RIVER. DAY SHIFT WILL HAVE TO MONITOR TRENDS...AS ADJUSTMENTS UP OR
DOWN AREA LIKELY DEPENDING ON CLOUD COVER EVOLUTION...THUS ANOTHER
LOW CONFIDENCE TEMPERATURE FORECAST.
UNSETTLED WEATHER RETURNS TONIGHT INTO THURSDAY. LOW LEVEL JET
INCREASES AGAIN TONIGHT...ADVECTING IN RICH THETAE AIR AND HIGH
PWATS. MEANWHILE IT SEEMS LIKELY THAT CONVECTION WILL FIRE THIS
AFTERNOON ACROSS THE NEBRASKA PANHANDLE AND WESTERN SOUTH DAKOTA AS
ANOTHER WAVE BEGINS TO EJECT OUT OF THE ROCKIES...AND THIS EVOLUTION
IS SUPPORTED BY ALMOST ALL HI RES GUIDANCE. THIS AREA OF CONVECTION
SHOULD WEAKEN AS IT APPROACHES OUR AREA...AS DESPITE THE THETAE
ADVECTION...WE DRY OUT ENOUGH TODAY THAT WE DONT QUITE COMPLETELY
RECOVER IN TIME. HOWEVER MAY SEE THE LINE OF STORMS MAKE IT INTO OUR
FAR WESTERN COUNTIES AFTER 03Z BEFORE IT DOES DISSIPATE...AND THUS
CAN NOT RULE OUT AN ISOLATED SEVERE WIND GUST WITH THAT ACTIVITY.
EVENTUALLY THE CONTINUED THETAE ADVECTION BECOMES ENOUGH TO SATURATE
US ENOUGH AND DEVELOP ELEVATED INSTABILITY. THUS THOUGHT IS SHOWERS
AND STORMS START BECOMING MORE NUMEROUS BY EARLY WEDNESDAY MORNING
AND THROUGH THE DAY. NOT SEEING MUCH TOO MUCH OF A SEVERE THREAT
WITH THIS ACTIVITY AS SOUNDINGS EXHIBIT MORE OF A HEAVY RAIN
SATURATED THIN CAPE PROFILE. HOWEVER WIND FIELDS ARE STRONGER...THUS
A FEW MARGINAL SEVERE STORMS ARE POSSIBLE WITH THIS ACTIVITY ANYTIME
WEDNESDAY. TOUGH TO PINPOINT EXACTLY WHERE THE HEAVIEST OF THE RAIN
ENDS UP GOING. BUT HI RES MODEL SOLUTIONS SEEM TO FAVOR MUCH OF THE
HEAVIER ACTIVITY WEDNESDAY ALONG AND EAST OF INTERSTATE 29...WITH
CONVECTION CONTINUOUSLY DEVELOPING ACROSS CENTRAL OR EASTERN
NEBRASKA AND MOVING NORTH NORTHEAST WITH THE MEAN WIND. GIVEN THE
TRAINING POTENTIAL AND HIGH PWATS...WEDNESDAY LOOKS TO BE A DAY WITH
AN ELEVATED FLOODING POTENTIAL.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 445 AM CDT TUE MAY 28 2013
WE MAY SEE A BREAK FOR A PERIOD LATER WEDNESDAY AFTERNOON INTO THE
EVENING AS THE TRAINING WAA CONVECTION SHIFTS EAST OF THE CWA.
HOWEVER ATTENTION THEN TURNS YO OUR WEST AS THE MAIN WAVE MOVES INTO
THE PLAINS. A LARGE AREA OF THUNDERSTORMS SHOULD FIRE ACROSS THE
WESTERN PLAINS WITH THIS WAVE...AND THEN MOVE INTO OUR CWA ANYTIME
FROM THE EVENING INTO THE OVERNIGHT. DUE TO CONSIDERABLE CLOUD COVER
INSTABILITY MAY NOT BE TOO HIGH...BUT WIND FIELDS SHOULD BE STRONG
ENOUGH TI SUPPORT ORGANIZED CONVECTION. THUS THINKING OUR GREATEST
SEVERE THREAT MAY END UP BEING WITH THIS ACTIVITY WEDNESDAY EVENING
OR NIGHT. A FEW SUPERCELLS POSSIBLE IN OUR WEST...BUT TIMING
SUGGESTS THAT THE CONVECTION WOULD PROBABLY BE LINEAR BY THE TIME IT
IMPACTS MOST OF OUR CWA...WITH STRONG WINDS THE GREATEST THREAT.
GIVEN THE POTENTIAL OF HEAVY RAIN EARLIER WEDNESDAY...ANY ADDITIONAL
RAIN WOULD ALSO ENHANCE THE FLOODING POTENTIAL.
MODELS CONTINUE TO SPEED UP THE MOVEMENT OF THE WAVE. THUS BY
THURSDAY THE GREATEST THUNDERSTORM THREAT SHOULD BE EAST OF
INTERSTATE 29...AND DURING THE FIRST PORTION OF THE DAY. THUS SEVERE
THREAT ON THURSDAY SHOULD END UP SOUTH AND EAST OF OUR CWA. BY LATER
THURSDAY AFTERNOON INTO THE OVERNIGHT THERE MAY NOT BE MUCH GOING ON
ACROSS OUR AREA. GOING WITH HIGHS IN THE 70S BOTH WEDNESDAY AND
THURSDAY...BUT THIS AGAIN DEPENDENT ON CLOUD COVER. AREAS THAT SEE
SUN COULD REACH THE 80S BOTH DAYS...WHILE 60S ARE A POSSIBILITY
WHERE CLOUDS HOLD TOUGH. /
THE PERSISTENT UPPER LOW OVER THE WESTERN UNITED STATES FINALLY
LIFTS NORTHEASTWARD TOWARD ND AND MN LATE THIS WEEK AND THROUGH THE
WEEKEND. THIS MEANS QUIETER WEATHER FOR OUR AREA. ALTHOUGH ONE
CANNOT RULE OUT A FEW SHOWERS OR ISOLATED THUNDERSTORMS IN OUR
FORECAST AREA FRIDAY AND SATURDAY...THE CHANCES OF ANY ONE LOCATION
GETTING A WETTING RAIN IS FAIRLY REMOTE. DRY WEATHER LOOKS TO
PREVAIL ON SUNDAY AND MONDAY. IN RESPONSE TO THE UPPER LOW LIFTING
CLOSER TO THE CANADIAN BORDER...COOL SURFACE HIGH PRESSURE WILL THEN
FILTER DOWN PROMISING MUCH BELOW NORMAL TEMPERATURES FOR THE
WEEKEND. ON FRIDAY AND MONDAY...70S SHOULD BE MORE WIDESPREAD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 622 PM CDT MON MAY 27 2013
TAF SITES HON/FSD/SUX ON THE EDGE OF MVFR/IFR STRATUS THIS
EVENING. STRATUS SHOULD EXPAND AND ADVECT EAST ACROSS THE REGION
THIS MID TO LATE EVENING. THUNDERSTORM COMPLEXES ARE EXPECTED TO
PUSH THROUGH THE REGION AGAIN TONIGHT MAINLY AFTER 05Z AND ENDING
BEFORE 12Z. SOME STORMS MAY BE STRONG AND REDUCED CONDITIONS TO
IFR AT TIMES. AREAS OF LOW STRATUS AND SOME HAZE/LIGHT FOG WILL
PERSIST THROUGH EARLY MORNING TUESDAY. VFR CONDITIONS ARE THEN
EXPECTED TO PREVAIL BY MID MORNING TUESDAY AND THROUGH THE DAY.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...FLASH FLOOD WATCH UNTIL 7 AM CDT THIS MORNING FOR SDZ067-070-071.
MN...DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR MNZ071-072-
080-081-089-090-097-098.
IA...FLASH FLOOD WATCH UNTIL 7 AM CDT THIS MORNING FOR IAZ001>003-
012>014-020>022-031-032.
DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR IAZ001>003-
012>014.
NE...FLASH FLOOD WATCH UNTIL 7 AM CDT THIS MORNING FOR NEZ013-014.
&&
$$
SHORT TERM...CHENARD
LONG TERM...CHENARD/MJF
AVIATION...
SEE BELOW FOR AN UPDATED AVIATION FORECAST DISCUSSION.
MADE SOME MAJOR CHANGES TO POPS THIS EVENING AND
OVERNIGHT BASED ON LATEST HRRR AND RUC. NEWEST GUIDANCE SUGGESTS
THE LINE OF TSTORMS CURRENTLY WEST RIVER WILL HAVE A VERY
DIFFICULT TIME PROGRESSING EASTWARD THIS EVENING. KEPT EVERYTHING
EAST OF THE JAMES VALLEY DRY WITH ONLY SLIGHT CHANCES AFTER
MIDNIGHT IN THE JAMES VALLEY ITSELF. ALSO LOWERED THE CHANCES OF
STORMS BETWEEN THE MISSOURI RIVER AND THE JAMES RIVER FOR THE NEXT
FEW HOURS. OTHERWISE FORECAST LOOKS ALRIGHT AND NO FURTHER CHANGES
WERE MADE.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH TUESDAY TONIGHT
THE POTENTIAL FOR SEVERE STORMS THROUGH THE SHORT TERM WILL BE THE
MAIN FORECAST CHALLENGE.
A STRONG SHORT WAVE CURRENTLY OVER NORTHERN WYOMING IS PRODUCING
SCT THUNDERSTORMS OVER NW SOUTH DAKOTA. THESE STORMS ARE HAVING A
DIFFICULT TIME MOVING EASTWARD DUE TO A STABLE ENVIRONMENT WITH
LITTLE INSTABILITY AND 0-6KM BULK SHEAR VALUES. BASED ON SEVERAL
HI-RES MODELS...IT SEEMS HIGHLY UNLIKELY CONVECTION WILL REACH THE
MISSOURI RIVER BEFORE 0Z...MAY PERHAPS THE JAMES RIVER CLOSER TO
6Z. GENERALLY EXPECTING A SLOW MOVING LINE OF SHOWERS WITH A FEW
EMBEDDED STRONGER STORM CELL. LOCALLY HEAVY RAINFALL WILL BE THE
MAIN THREAT ALONG WITH GUSTY WINDS AND SMALL HAIL.
CONVECTION SHOULD CLEAR THE CWA SHORTY AFTER 12Z TUESDAY WITH
MOSTLY DRY CONDITIONS PREVAILING THROUGH THE REST OF THE DAY. THAT
SAID...A WEAK FRONTAL BOUNDARY SLIDING ACROSS THE REGION AROUND
PEAK HEATING COULD PRODUCE A FEW SHOWERS AND THUNDERSTORMS. WHILE
CAPE VALUES ARE FAIRLY GOOD AHEAD OF THE FRONT...LIMITED UPPER
LEVEL LIFT AND SHEAR IS LACKING SO STRONG STORMS APPEAR UNLIKELY.
INCREASING LLM VIA SOUTHERLY FLOW FROM THE CENTRAL PLAINS WILL
DEVELOP TUESDAY NIGHT. A FEW MODELS ARE SUGGESTING THE LOW LEVEL
WINDS WILL VEER BACKWARD TOWARDS THE BLACK HILLS REGION WHERE UP-
SLOPE CONVECTION WILL BE POSSIBLE. OTHERWISE WOULD EXPECT MOST OF
THIS CWA WILL SEE DRY CONDITIONS ON TUESDAY NIGHT.
.LONG TERM...WEDNESDAY THROUGH MONDAY
THE MODELS CONTINUE TO AGREE WELL TO BEGIN THE LONG TERM AND THEN
DIVERGE SOME THROUGH MID AND LATE IN THE LONG TERM. A STRONGLY
NEGATIVELY TILTED UPPER LEVEL LOW PRESSURE TROUGH IN THE SOUTHWEST
US IS STILL ON SCHEDULE TO MAKE ITS WAY INTO THE NORTHERN PLAINS
THROUGH WEDNESDAY NIGHT AND EARLY THURSDAY. AS IT DOES...THE
TROUGH WILL CLOSE OFF OVER THE REGION THURSDAY. THE MODELS
DISAGREE ON THE LOCATION OF CENTER OF THE UPPER LEVEL LOW PRESSURE
CIRCULATION AND SUBSEQUENT TRACKING EAST AND SOUTHEAST FRIDAY
NIGHT THROUGH SATURDAY. WITH LARGE BROAD SCALE LIFT IN ADVANCE OF
THIS UPPER TROUGH ON WEDNESDAY AND WEDNESDAY NIGHT ALONG WITH A
GOOD WARM FRONT SURGING NORTHWARD ACROSS OUR REGION...EXPECT
NUMEROUS SHOWERS AND THUNDERSTORMS TO DEVELOP ACROSS ALL OF THE
REGION. EVERYTHING WILL BE IN PLACE FOR SOME SEVERE WEATHER
DEVELOPMENT WEDNESDAY AND WEDNESDAY EVENING WITH A STRONG LLJ
ALONG WITH DEEP LAYER SHEAR AND INSTABILITY. IF CONVECTION
DEVELOPS EARLY AND IS WIDESPREAD...SEVERE WEATHER MAY BE MORE
LIMITED. HAVE IN GOOD CHANCES FOR WEDNESDAY AND WEDNESDAY NIGHT.
DEPENDING ON WHERE THE SURFACE LOW PRESSURE AREA DEVELOPS AND
TRACKS ALONG WITH THE SURFACE DRY LINE/COLD FRONT...THURSDAY MAY
ALSO HAVE SOME SEVERE WEATHER MAINLY EAST IN THE CWA.
OTHERWISE...KEPT CHANCES OF SHOWERS AND STORMS IN THROUGH SATURDAY
BEFORE DRYING IT OUT SATURDAY NIGHT THROUGH SUNDAY NIGHT WITH
ANOTHER CHANCE BACK IN THE FORECAST FOR MONDAY. TEMPERATURES
SHOULD BE NEAR TO ABOVE NORMAL FOR WEDNESDAY AND THURSDAY BEFORE
COOLING BACK TO NEAR TO BELOW NORMAL FOR FRIDAY THROUGH SUNDAY
WITH NORTHERLY SURFACE WINDS. MONDAY SHOULD WARM BACK UP WITH MORE
SUNSHINE WITH THE AFFECTS OF UPPER LEVEL TROUGHING COMING IN FROM
THE WEST BRINGING THE CHANCE OF RAINFALL.
&&
.AVIATION...
06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
EXPECT CEILINGS TO LOWER AGAIN AFTER MIDNIGHT AT MBG AND ABR.
EXPECTING IFR CEILINGS ALONG WITH SOME FOG AT ABR...ATY AND PIR AGAIN
TONIGHT AND TUESDAY MORNING AS LOW LEVEL MOISTURE REMAINS HIGH.
OTHERWISE...A SHORT WAVE TROUGH LIFTING ACROSS THE WESTERN PART OF
THE REGION WILL BRING SOME SHOWERS TO MOST OF THE AREA.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...DORN
SHORT TERM...SD
LONG TERM...MOHR
AVIATION...DORN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
330 PM CDT TUE MAY 28 2013
.SHORT TERM...
ANALYSIS OF THE 12Z RAOB DATA INDICATED A BROAD TROUGH OVER THE
WESTERN CONUS WITH A MODEST 70KT H25 JET STREAK DOWNSTREAM. A QUASI
STATIONARY FRONT WAS DRAPED ACROSS THE PLAINS...ARCING SOUTHWEST TO
THE OK PANHANDLE WITH A DRYLINE DROPPING SOUTH FROM A TRIPLE POINT
IN SOUTHWEST KS. A DEEP PLUME OF LOWER TROPOSPHERIC MOISTURE WAS
FOUND IN THE WARM SECTOR JUST TO THE EAST OF THE DRYLINE FROM THE
BIG BEND INTO THE OHIO VALLEY. STRONG MID LEVEL WARM ADVECTION HAS
ENHANCED H85-H7 FRONTOGENESIS...RESULTING IN ELEVATED CONVECTION
ACROSS WEST CENTRAL TX. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS
HAVE PERSISTED ALL DAY ACROSS PORTIONS OF THE CONCHO VALLEY AND BIG
COUNTRY...SUPPRESSING DIURNAL HEATING AND CAPPING OFF THE STRONG
INSTABILITY THAT EXISTS ACROSS THE REGION. TEMPS HAVE STRUGGLED TO
REACH 80 DEGREES ACROSS THE NORTH AND WEST BUT DEWPOINTS HAVE BEEN
MAINTAINED IN THE MID 60S AREAWIDE.
THE BIG QUESTION IS HOW THIS DAYTIME CONVECTION WILL AFFECT THE
POTENTIAL FOR ADDITIONAL SHOWERS AND THUNDERSTORMS THIS AFTERNOON
AND EVENING. THE 19Z RAP-BASED MESOANALYSIS INDICATES MLCAPE VALUES
APPROACHING 4000 J/KG /WITH CINH ALL BUT GONE/ ACROSS THE WESTERN
TIER WHERE WERE HAVE MANAGED TO SEE A LITTLE SUN. THIS MAY BE A
LITTLE OVERDONE WHEN COMPARED TO THE EXPERIMENTAL ESRL RAP VERSION
AS WELL AS THE NAM POINT SOUNDINGS WHICH SHOW SIGNIFICANTLY MORE
CINH STILL PRESENT. I DO ANTICIPATE ADDITIONAL SURFACE BASED STORMS
FIRING TO THE WEST OF THE CWA THIS AFTERNOON BUT THEY WILL HAVE TO
CONTEND WITH THE CAPPING INVERSION AS THEY MOVE EAST. THIS SHOULD
KEEP THE GREATEST POTENTIAL FOR SEVERE CONVECTION ACROSS THE
NORTHWEST 1/3 OF THE CWA WITH MAINLY SHOWERS AND ISOLATED
THUNDERSTORMS POSSIBLE ACROSS THE REMAINDER OF THE AREA. WITH A
STOUT LOW LEVEL JET AND AT LEAST SOME LARGE SCALE ASCENT EXPECTED
TONIGHT...WE MAY SEE SHOWERS AND THUNDERSTORMS LINGER THROUGH THE
OVERNIGHT HOURS. I EXPECT MIN TEMPS NEAR PERSISTENCE WITH MOST AREAS
WITHIN A DEGREE OR TWO OF 70.
WEDNESDAY/S CONVECTIVE FORECAST IS QUITE TRICKY...DEPENDING ON
WHETHER OR NOT WE SEE NOCTURNAL CONVECTION LASTING INTO THE MORNING
HOURS. SUBSTANTIAL SYNOPTIC SCALE FORCING WILL HELP ERODE ANY CAP
AND WE MAY SEE RATHER JUNKY...DISORGANIZED CONVECTION DEVELOP EARLY
IN THE DAY. IF THE CAP HOLDS UNTIL MID AFTERNOON...THE POTENTIAL FOR
SEVERE WEATHER WILL INCREASE SIGNIFICANTLY. FORECAST MLCAPE VALUES
IN THE NEIGHBORHOOD OF 2000 J/KG AND 35+ KTS OF DEEP LAYER SHEAR
WOULD SUPPORT ORGANIZED CONVECTION WITH THE GREATEST THREAT EXISTING
ACROSS THE BIG COUNTRY. THERE IS STILL A LOT OF UNCERTAINTY AT THIS
TIME AND I HAVE CONTINUED CHANCE POPS ACROSS THE NORTH THROUGH THE
AFTERNOON HOURS. MAX TEMPS ARE EXPECTED TO BE IN THE MID 80S.
JOHNSON
.LONG TERM...
BY TOMORROW EVENING THE UPPER LOW WILL BE OVER THE NORTHERN
ROCKIES WITH THE ASSOCIATED TROUGH TRAILING SOUTHEAST INTO TEXAS.
ANY LINGERING SHOWERS AND THUNDERSTORMS OVER OUR AREA WILL BE
ENDING FROM THE WEST TOMORROW EVENING...AND SHOULD BE OUT OF THE
AREA BY THURSDAY MORNING. THE UPPER LOW WILL CONTINUE TO DEEPEN
AS IT MOVES THROUGH THE CENTRAL PLAINS THIS WEEKEND AND WILL PUSH
A COLD FRONT THROUGH THE PANHANDLE ON SATURDAY MORNING AND THROUGH
MOST OF THE CWA SATURDAY NIGHT...BEFORE STALLING IN THE VICINITY
OF THE INTERSTATE 10 CORRIDOR. THIS FRONTAL BOUNDARY WILL GIVE US
OUR NEXT CHANCE FOR RAINFALL WITH A CHANCE OF SHOWERS AND
THUNDERSTORMS OVER THE NORTHERN CWA DURING THE DAY ON SATURDAY
WITH CHANCES INCREASING LATE SATURDAY AND INTO SATURDAY NIGHT OVER
THE ENTIRE FORECAST AREA AS THE FRONT CONTINUES TO MOVE SOUTH
BEFORE STALLING SUNDAY MORNING.
SHOULD SEE SOME GOOD PREFRONTAL WARMING THURSDAY AND FRIDAY WITH
AFTERNOON HIGHS IN THE LOWER TO UPPER 90S BOTH DAYS. SUNDAY HIGHS
WILL BE IN THE MID 80S...WARMING BACK INTO THE 90S ON MONDAY.
MORNING LOWS IN THE LOW TO MID 70S FRIDAY WILL COOL INTO THE 60S
BY SUNDAY MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 71 85 68 94 73 / 30 30 30 10 5
SAN ANGELO 71 86 70 94 74 / 20 20 20 10 5
JUNCTION 71 85 66 92 71 / 20 20 20 10 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
15
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1247 PM CDT TUE MAY 28 2013
.AVIATION...
BREEZY SOUTH WINDS WILL CONTINUE THIS AFTERNOON AT KLBB AND KCDS.
EXPECT THUNDERSTORMS TO DEVELOP ALONG THE DRYLINE...IMPACTING KLBB
BY AROUND 21Z AND KCDS NEAR THE 23Z TIME FRAME AS ACTIVITY MOVES
EAST/NORTHEAST. INSERTED MVFR CEILINGS AND VCTS AT THESE
RESPECTIVE TIMES...LIFTING CONDITIONS BACK TO VFR BY 03Z AT KLBB
AND 04Z AT KCDS. WILL LIKELY SEE SOME LOW STRATUS TONIGHT AND
EARLY WEDNESDAY MORNING...BUT LOCATION AND INTENSITY WILL DEPEND
ON RAINFALL AMOUNTS THIS AFTERNOON AND EVENING.
&&
.PREV DISCUSSION... /ISSUED 1154 AM CDT TUE MAY 28 2013/
UPDATE...
SEVERE WEATHER THREAT STILL ON TAP FOR THIS AFTERNOON INTO THIS
EVENING ACROSS MUCH OF THE EXTREME SOUTHERN TEXAS
PANHANDLE...SOUTH PLAINS...AND ROLLING PLAINS. ISOLATED TO WIDELY
SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE PERMIAN BASIN
CONTINUE LATE THIS MORNING AHEAD OF A SLOT OF MID-UPPER LEVEL
DRYING PUSHING INTO SOUTHEASTERN NEW MEXICO DOWNSTREAM OF A
SHORTWAVE TROUGH MOVING INTO CENTRAL ARIZONA...BUT TRENDS HAVE
BEEN FOR THESE CELLS TO DECREASE IN INTENSITY FARTHER NORTHEAST
INTO THE ROLLING PLAINS AS THEY LOSE THEIR SOURCE OF LIFT.
CURRENT SATELLITE IMAGERY DEPICTS AN EXPANSIVE AREA OF CLOUD COVER
EAST OF A TULIA TO TATUM LINE. SURFACE OBSERVATIONS INDICATE WIND
FIELDS ARE REMAINING BACKED ACROSS MUCH OF THE CAPROCK...MOST
NOTABLY FARTHER SOUTH INTO THE SOUTHERN SOUTH PLAINS. LEE
TROUGHING EXTENDING INTO EASTERN NEW MEXICO SHOULD ALLOW THE
DRYLINE TO HOLD ON THE CAPROCK THIS AFTERNOON.
EXPECT CONVECTIVE INITIATION TO OCCUR BY MID AFTERNOON ALONG AN
APPROXIMATE TULIA TO BROWNFIELD LINE. DISCRETE CELLS SHOULD
DEVELOP INITIALLY GIVEN 30-40 KNOTS OF 0-6 KM BULK SHEAR BEFORE
CONSOLIDATING INTO A LINE ALONG THE DRYLINE AS DEEP LAYER FORCING
INCREASES. LARGE HAIL UP TO TENNIS BALL SIZE WILL BE THE PRIMARY
THREAT GIVEN STEEP LAPSE RATES ABOVE THE ELEVATED MIXED LAYER
OWING TO AROUND 3000 J/KG OF CAPE. WIND GUSTS TO 60 MPH WILL ALSO
BE POSSIBLE ALONG WITH AN ISOLATED TORNADO THREAT THIS EVENING
WITH THE ONSET OF THE LOW LEVEL JET PROMOTING INCREASING LOW LEVEL
SHEAR PROFILES.
PREV DISCUSSION... /ISSUED 354 AM CDT TUE MAY 28 2013/
SHORT TERM...
CONSIDERABLE MID AND UPPER LEVEL MOISTURE WAS SPREADING INTO THE
AREA FROM THE SOUTHWEST ASSOCIATED WITH A WAVE LIFTING OUT ACROSS
THE SOUTHERN HIGH PLAINS THIS AFTERNOON. ONLY ISOLATED THUNDERSTORMS
HAVE DEVELOPED THUS FAR WITH THIS WAVE OVER SOUTHWEST TEXAS...WHILE
SOLUTIONS REMAIN DECIDEDLY MIXED REGARDING HOW MUCH DEVELOPMENT MAY
OCCUR ACROSS THE TEXAS SOUTH PLAINS REGION LATER THIS MORNING. THE
LATEST WRF/NAM APPEARS QUITE SHOWERY BY MID MORNING INTO THE
AFTERNOON WITH WANING ACTIVITY INTO THE EVENING OWING TO A MORE
STABLE ENVIRONMENT...WHILE THE LATEST RAP ON THE OTHER HAND DELAYS
THE RELEASE OF CONVECTIVE ENERGY UNTIL AFTER NOON WHEN THUNDERSTORMS
EXPLODE ALONG THE SURFACE DRY-LINE FROM THE WESTERN SOUTH PLAINS
INTO THE SOUTHERN PANHANDLE. WHAT SEEMS CERTAIN IS THAT THE CLOUDS
WILL SPREAD OVER THE AREA HOLDING TEMPERATURES DOWN INTO THE
AFTERNOON. ALSO...IT SEEMS PLAUSIBLE THAT AT LEAST LIGHT SHOWERS AND
PERHAPS A FEW THUNDERSTORMS WILL SPREAD UP INTO THE AREA LATER IN
THE MORNING...THOUGH COVERAGE OF THIS ACTIVITY IS HIGHLY UNCERTAIN.
THEREFORE...WE REMAIN LESS CONFIDENT HOW THIS MAY IMPACT REMAINING
CONVECTIVE ENERGY LATER TODAY. WE HAVE SOMEWHAT SPLIT BETWEEN THE
POSSIBLE CHOICES...HOLDING CHANCES LOW THIS MORNING THOUGH RETAINING
MODEST CHANCES FOR SEVERE STORMS THIS AFTERNOON AND EVENING. THE
MAXIMUM POTENTIAL ENERGY AND SHEAR PROFILES LATER TODAY CERTAINLY
SUGGEST OPPORTUNITY FOR AT LEAST A FEW SUPERCELLS WITH LARGE OR EVEN
VERY LARGE HAIL POTENTIAL...WHILE HELICITY LEVELS AND CONVERGENCE
ALONG THE DRY-LINE WOULD OFFER ISOLATED TORNADO THREAT AS WELL WITH
LIFTED CONDENSATION LEVELS POSSIBLY AS LOW AS 3000-6000 FEET. GIVEN
THIS POTENTIAL WITH OUR REDUCED CONFIDENCE...WE THINK IT MAY BE BEST
TO LEAN A BIT TOWARDS THE WORSER OUTCOME UNTIL CLARITY IMPROVES. WE
INCREASED CHANCES SLIGHTLY TODAY AND TONIGHT...RETAINING SEVERE
MENTION DURING THE AFTERNOON AND EVENING. MINOR CHANGES FOR MAJORITY
OF GRID FIELDS. RMCQUEEN
LONG TERM...
WEDNESDAY STILL APPEARS TO HAVE THE POTENTIAL FOR A REGIONAL
SEVERE WEATHER OUTBREAK ACROSS THE ROLLING PLAINS INTO THE EASTERN
TEXAS PANHANDLE AND OKLAHOMA. THE DRYLINE WILL MIX EAST ON
WEDNESDAY BUT UNCERTAINTY REMAINS WITH HOW FAR THE DRYLINE WILL
MOVE. THE UPPER LEVEL NEGATIVELY TILTED TROUGH AXIS WILL PASS OVER
WEST TEXAS MIDDAY ON WEDNESDAY. UNTIL THIS POINT...WEST TEXAS WILL
BE UNDER THE INFLUENCE OF THE FAVORABLE EAST SIDE OF THE
TROUGH/UPPER LEVEL JET. ISENTROPIC LIFT WILL BEGIN TO PROVIDE LIFT
BEGINNING EARLY IN THE EVENING WITH THE INCREASING LOW LEVEL JET.
SURFACE INSTABILITY WILL LIKELY BECOME UNCAPPED IN THE AFTERNOON
WITH PROGGED CAPE VALUES CRESTING AT 3000-3500 J/KG. INCREASING
DEEP LAYER SHEAR WILL BE SUPPORTIVE OF ROTATING SUPERCELLS.
DISCRETE SUPERCELLS WILL LIKELY BE THE FAVORED MODE OF CONVECTION
WITH SHEAR VECTORS NEARLY NORMAL TO THE DRYLINE.
SUBSIDENCE WILL BEGIN TO SPREAD OVER THE REGION WEDNESDAY NIGHT AS
WELL AS ASSOCIATED HEIGHT RISES. THIS WILL PERSIST THROUGH THE DAY
ON FRIDAY KEEPING THURSDAY AND FRIDAY MOSTLY DRY. BY LATE ON
FRIDAY OR EARLY SATURDAY A COLD FRONT WILL MAKE A RUN AT THE AREA
WHICH MAY BRING THE NEXT CHANCE OF SHOWERS AND THUNDERSTORMS.
THERE EXISTS A LACK OF CONFIDENCE IN THE MODEL SOLUTIONS AT THE
MOMENT IN REGARDS TO WHERE THE FRONT WILL STALL OUT.
NONETHELESS...HEAVY RAIN MAY BE A POSSIBILITY WHEREVER THE FRONT
DOES BECOME STATIONARY. JDV
FIRE WEATHER...
A DRYLINE WILL MOVE EAST ON WEDNESDAY AFTERNOON TO THE EDGE OF THE
CAPROCK. THIS WILL LEAD TO VERY DRY CONDITIONS ON THE SOUTH
PLAINS BOTH AFTERNOONS. DEEP MIXING WILL PRODUCE BREEZY WINDS ON
WEDNESDAY AFTERNOON WHICH WILL LEAD TO ELEVATED TO PERHAPS BRIEFLY
CRITICAL FIRE WEATHER CONDITIONS. THIS DRYLINE WILL MOVE EVEN
FARTHER EAST ON THURSDAY SPAWNING A LARGER CRITICAL AREA ON
THURSDAY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 65 92 58 93 59 / 30 20 0 0 0
TULIA 67 89 59 92 61 / 30 20 10 0 0
PLAINVIEW 67 90 61 94 63 / 30 20 10 0 0
LEVELLAND 68 93 61 95 63 / 30 20 10 0 0
LUBBOCK 68 92 64 95 65 / 30 20 10 0 0
DENVER CITY 68 93 60 96 65 / 30 20 0 0 0
BROWNFIELD 69 93 63 96 64 / 30 20 10 0 0
CHILDRESS 69 86 69 95 70 / 30 40 30 10 10
SPUR 69 88 68 95 69 / 30 30 20 10 10
ASPERMONT 71 87 72 94 71 / 30 40 30 10 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1225 PM CDT TUE MAY 28 2013
.DISCUSSION...
SEE 18Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...
MVFR CIGS ARE EXPECTED TO PREVAIL ACROSS ALL TERMINALS THROUGH
APPROX 21Z. DAYTIME HEATING WILL PRODUCE ENOUGH MIXING TO LIFT
CIGS TO VFR FOR THE REST OF THE AFTERNOON AND INTO THE LATE
EVENING HOURS. MVFR CIGS WILL ONCE AGAIN RETURN THE THE AREA AFTER
05Z. THERE IS A POSSIBILITY FOR IFR CIGS TO DEVELOP OVER KSOA BUT
CONFIDENCE IS TOO LOW AT THIS TIME TO MENTION. GUSTY SOUTH WINDS
WILL DIMINISH ACROSS THE KBBD TERMINAL AFTER 00Z THOUGH WINDS WILL
STILL BE ABOVE 10 KNOTS. ELSEWHERE GUSTY SOUTH WINDS ARE EXPECTED TO
PERSIST THROUGHOUT THE FORECAST PERIOD. THERE IS A CHANCE OF
PRECIPITATION MAINLY ACROSS THE KSOA...KSJT...AND KABI TERMINALS.
THOUGH THERE IS UNCERTAINTY SURROUNDING THE POSITION OF THE
DRYLINE. FOR THIS REASON I LEFT OUT MENTION OF SHOWERS.
&&
.PREV DISCUSSION... /ISSUED 1056 AM CDT TUE MAY 28 2013/
UPDATE...
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE TO MOVE EAST
ACROSS THE BIG COUNTRY AND CONCHO VALLEY THIS MORNING AS THE LOW
LEVEL JET INTERACTS WITH A MODERATELY UNSTABLE ENVIRONMENT. THIS
ACTIVITY WILL REMAIN GENERALLY WEAK BUT WILL WORK TO KEEP TEMPS IN
THE 70S FOR A FEW MORE HOURS. HOW THIS AFFECTS AFTERNOON/EVENING
CONVECTION CHANCES REMAINS TO BE SEEN AS SURFACE BASED INSTABILITY
WILL BE LIMITED AND THE CAP MAY BE DIFFICULT TO OVERCOME. THAT
SAID...IF WE GET A FEW HOURS OF HEATING...IT SHOULD NOT BE THAT
BIG OF AN ISSUE. THIS WOULD PUT THE GREATEST THREAT FOR DIURNAL
CONVECTION OVER THE CONCHO VALLEY AND EDWARDS PLATEAU WHERE THE
GREATEST HEATING IS EXPECTED TO OCCUR. WILL CONTINUE TO WATCH THE
RADAR TRENDS THROUGHOUT THE DAY AS THIS SITUATION EVOLVES. THE
FORECAST HAS BEEN UPDATED TO LOWER MAX TEMPS AND EXPAND POPS
FARTHER EAST. OTHERWISE...MOST CHANGES WERE RELATIVELY MINOR.
JOHNSON
PREV DISCUSSION... /ISSUED 645 AM CDT TUE MAY 28 2013/
DISCUSSION...
SEE 12Z AVIATION DISCUSSION BELOW.
AVIATION...
STRATUS HAS BEEN RATHER SPORADIC THIS MORNING DUE TO ABUNDANT
HIGH CLOUDS STREAMING IN FROM THE SOUTHWEST. WILL HANDLE MVFR
CIGS WITH TEMPO GROUPS THIS MORNING WITH PREDOMINANT VFR EXPECTED
ACROSS THE TERMINALS BY AFTERNOON. WIDELY SCATTERED CONVECTION HAS
FORMED WEST OF THE AREA THE PAST COUPLE OF HOURS. THE MOST LIKELY
TERMINAL TO BE AFFECT BY THIS ACTIVITY IS KSJT AND HAVE INCLUDED
A TEMPO GROUP FOR THUNDER UNTIL 14Z. ADDITIONAL THUNDERSTORMS ARE
EXPECTED TO DEVELOP WEST OF THE TERMINALS LATE THIS AFTERNOON WITH
ACTIVITY POSSIBLY SPREADING ACROSS THE AREA THIS EVENING. NORTHERN
TERMINALS HAVE THE BEST CHANCE TO SEE CONVECTION BUT DUE TO TIMING
AND COVERAGE UNCERTAINTY WILL NOT MENTION AT THIS TIME. MVFR CIGS
RETURN TO THE TERMINALS LATE TONIGHT INTO THURSDAY MORNING.
PREV DISCUSSION... /ISSUED 544 AM CDT TUE MAY 28 2013/
UPDATE...
FORECAST WAS UPDATED TO ADD POPS THIS MORNING.
DISCUSSION...
ELEVATED CONVECTION HAS FORMED OVER THE TRANS PECOS REGION EARLY
THIS MORNING...MOST LIKELY DUE TO AN EMBEDDED DISTURBANCE IN THE
FLOW ALOFT. LATEST HRRR SEEMS TO HAVE THE BEST HANDLE ON THIS
ACTIVITY AND EXPANDS IT AS IT MOVES NORTHEAST ACROSS THE AREA
THROUGH THE MORNING HOURS. SHOULD SEE A WEAKENING TREND THOUGH
BUT DID ADD MENTIONABLE POPS THIS MORNING MAINLY WEST OF A
THROCKMORTON...TO MILLERSVIEW...TO OZONA LINE. NO OTHER CHANGES
WERE MADE.
PREV DISCUSSION... /ISSUED 359 AM CDT TUE MAY 28 2013/
SHORT TERM...
THROUGH TONIGHT..
THE MAIN CONCERN IN THE SHORT TERM PERIOD WILL BE THUNDERSTORM
CHANCES AND THE POSSIBILITY OF A FEW STRONG TO SEVERE STORMS
MAINLY ACROSS WESTERN SECTIONS THIS EVENING AND OVERNIGHT.
AN UPPER TROUGH CURRENTLY CROSSING THE GREAT BASIN REGION WILL
AMPLIFY ACROSS THE CENTRAL AND SOUTHERN ROCKIES LATER TODAY. LEE
SURFACE LOW WILL RESULT IN A TIGHTENING PRESSURE GRADIENT AGAIN
TODAY WITH GUSTY SOUTH WINDS CONTINUING. MUCH LIKE YESTERDAY...LOW
CLOUDS WILL OVERSPREAD MUCH OF THE AREA BY DAYBREAK BUT SHOULD
BEGIN TO SCATTER OUT BY LATE MORNING. THE DRYLINE WILL SETUP
ACROSS FAR WEST TEXAS THIS AFTERNOON AND WILL AGAIN BE THE FOCUS
FOR THUNDERSTORM DEVELOPMENT. STORMS THAT DEVELOP WILL LIKELY
BECOME SEVERE GIVEN MODERATE INSTABILITY AND ADEQUATE DEEP LAYER
SHEAR.
CURRENT THINKING IS THAT MOST OF THIS ACTIVITY WILL REMAIN WEST OF
THE AREA THROUGH LATE AFTERNOON BUT WILL PROPAGATE NORTHEAST
TOWARDS OUR WESTERN COUNTIES DURING THE EVENING HOURS. ADDITIONAL
STORMS MAY DEVELOP ALONG THE RETREATING DRYLINE THIS EVENING AND
MOVE TOWARDS THE AREA DURING THE OVERNIGHT PERIOD. HIGHEST POPS
WERE ORIENTED NORTH AND WEST OF A HASKEL...TO SAN ANGELO...TO
OZONA LINE THIS EVENING AND OVERNIGHT. THE MAIN SEVERE WEATHER
HAZARDS WILL BE LARGE HAIL AND DAMAGING STRAIGHT LINE WINDS. HIGH
TEMPERATURES TODAY WILL BE MAINLY IN THE UPPER 80S WITH LOWS
TONIGHT IN THE LOWER 70S.
24
LONG TERM...
THE MAIN HIGHLIGHTS IN THE EXTENDED FORECAST ARE A CHANCE OF
SEVERE WEATHER ACROSS MUCH OF THE AREA WEDNESDAY...FOLLOWED BY
INCREASING RAIN CHANCES THIS WEEKEND WITH A COLD FRONT. A LARGE
UPPER LEVEL TROUGH WILL BE APPROACHING WEST CENTRAL TEXAS
WEDNESDAY. ALTHOUGH A FEW STORMS COULD BE ONGOING DURING THE EARLY
MORNING HOURS...FROM ANY OVERNIGHT CONVECTION ...I BELIEVE THAT
MOST OF THE CONVECTION ON WEDNESDAY WILL BE DURING THE LATE
AFTERNOON AND EARLY EVENING HOURS. THE DRYLINE WILL SHARPEN AND
MIGRATE TOWARD OUR WESTERN BORDER BY MID AFTERNOON. AS THE UPPER
LEVEL TROUGH APPROACHES...LARGE SCALE LIFT WILL AID IN
THUNDERSTORM DEVELOPMENT ALONG AND EAST OF THE DRYLINE...
ESPECIALLY ACROSS THE BIG COUNTRY. A FAIRLY UNSTABLE ATMOSPHERE
COMBINED WITH 0-6 KM BULK SHEAR VALUES BETWEEN 35 AND 50
KNOTS...MAY RESULT IN A FEW STRONG TO SEVERE THUNDERSTORMS...
ESPECIALLY ACROSS THE BIG COUNTRY. ALTHOUGH LARGE HAIL AND
DAMAGING WINDS WILL BE THE MAIN CONCERNS...AN ISOLATED TORNADO
CANNOT BE RULED OUT. CONVECTION SHOULD CONTINUE INTO THE EVENING
HOURS AND MOVE FROM WEST TO EAST...EVENTUALLY MOVING EAST OF THE
REGION DURING THE EARLY MORNING HOURS. HIGH TEMPERATURES WILL BE
NEAR NORMAL...GENERALLY IN THE MID TO UPPER 80S...WITH LOW
TEMPERATURES NEAR 70.
DRIER AND WARMER CONDITIONS ARE FORECAST BOTH THURSDAY AND
FRIDAY...WITH HIGHS GENERALLY IN THE 90S AND LOWS NEAR 70. MODELS
ARE INDICATING THE NEXT UPPER LEVEL LOW/TROUGH MOVING ACROSS THE
NORTHERN AND CENTRAL PLAINS LATE FRIDAY AND SATURDAY. THIS WILL
SEND A LATE SEASON COLD FRONT INTO WEST CENTRAL TEXAS LATE
SATURDAY OR EARLY SUNDAY. SCATTERED SHOWERS AND THUNDERSTORMS WILL
BE POSSIBLE IN ASSOCIATION WITH THE FRONT...MAINLY LATE SATURDAY
TROUGH SUNDAY. SLOW MOVING...LATE SEASON COLD FRONTS LIKE THIS ONE
HAVE HAD A HISTORY OF PRODUCING MUCH NEEDED RAINFALL ACROSS WEST
CENTRAL TEXAS. IT IS A BIT TOO EARLY TO DECIPHER EXACTLY WHERE THE
FRONT WILL STALL...AND HOW MUCH CONVECTION WILL DEVELOP...BUT THE
DETAILS SHOULD BECOME MORE CLEAR IN THE NEXT COUPLE OF DAYS.
DANIELS
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 86 71 85 71 91 / 30 30 30 30 10
SAN ANGELO 88 72 88 70 94 / 20 20 30 20 10
JUNCTION 86 73 85 72 90 / 10 20 20 20 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/18
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1154 AM CDT TUE MAY 28 2013
.UPDATE...
SEVERE WEATHER THREAT STILL ON TAP FOR THIS AFTERNOON INTO THIS
EVENING ACROSS MUCH OF THE EXTREME SOUTHERN TEXAS
PANHANDLE...SOUTH PLAINS...AND ROLLING PLAINS. ISOLATED TO WIDELY
SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE PERMIAN BASIN
CONTINUE LATE THIS MORNING AHEAD OF A SLOT OF MID-UPPER LEVEL
DRYING PUSHING INTO SOUTHEASTERN NEW MEXICO DOWNSTREAM OF A
SHORTWAVE TROUGH MOVING INTO CENTRAL ARIZONA...BUT TRENDS HAVE
BEEN FOR THESE CELLS TO DECREASE IN INTENSITY FARTHER NORTHEAST
INTO THE ROLLING PLAINS AS THEY LOSE THEIR SOURCE OF LIFT.
CURRENT SATELLITE IMAGERY DEPICTS AN EXPANSIVE AREA OF CLOUD COVER
EAST OF A TULIA TO TATUM LINE. SURFACE OBSERVATIONS INDICATE WIND
FIELDS ARE REMAINING BACKED ACROSS MUCH OF THE CAPROCK...MOST
NOTABLY FARTHER SOUTH INTO THE SOUTHERN SOUTH PLAINS. LEE
TROUGHING EXTENDING INTO EASTERN NEW MEXICO SHOULD ALLOW THE
DRYLINE TO HOLD ON THE CAPROCK THIS AFTERNOON.
EXPECT CONVECTIVE INITIATION TO OCCUR BY MID AFTERNOON ALONG AN
APPROXIMATE TULIA TO BROWNFIELD LINE. DISCRETE CELLS SHOULD
DEVELOP INITIALLY GIVEN 30-40 KNOTS OF 0-6 KM BULK SHEAR BEFORE
CONSOLIDATING INTO A LINE ALONG THE DRYLINE AS DEEP LAYER FORCING
INCREASES. LARGE HAIL UP TO TENNIS BALL SIZE WILL BE THE PRIMARY
THREAT GIVEN STEEP LAPSE RATES ABOVE THE ELEVATED MIXED LAYER
OWING TO AROUND 3000 J/KG OF CAPE. WIND GUSTS TO 60 MPH WILL ALSO
BE POSSIBLE ALONG WITH AN ISOLATED TORNADO THREAT THIS EVENING
WITH THE ONSET OF THE LOW LEVEL JET PROMOTING INCREASING LOW LEVEL
SHEAR PROFILES.
&&
.PREV DISCUSSION... /ISSUED 712 AM CDT TUE MAY 28 2013/
AVIATION...
INITIAL SHOWERS SPREADING NORTHEAST THROUGH PERMIAN BASIN SEEM
UNLIKELY TO SPREAD INTO EITHER TAF SITE...AT LEAST NEXT FEW HOURS.
SHOULD THESE SHOWERS STAY AWAY...THE CHANCES FOR STRONG OR SEVERE
THUNDERSTORMS WOULD INCREASE LATER THIS AFTERNOON AND EVENING.
LATEST TAF PACKAGE BASICALLY FOLLOWS THIS PLAN RETAINING BEST
THUNDER CHANCES FOR LATE IN THE DAY. A NEAR MVFR STRATUS LAYER IS
STILL EXPECTED TO SPREAD CLOSE TO KCDS BY LATE MORNING AS WELL...
THOUGH CEILING REMAINS DOUBTFUL. LOW LEVEL SOUTH TO SOUTHEAST FLOW
WILL STRENGTHEN LATER THIS MORNING AND AFTERNOON. RMCQUEEN
PREV DISCUSSION... /ISSUED 354 AM CDT TUE MAY 28 2013/
SHORT TERM...
CONSIDERABLE MID AND UPPER LEVEL MOISTURE WAS SPREADING INTO THE
AREA FROM THE SOUTHWEST ASSOCIATED WITH A WAVE LIFTING OUT ACROSS
THE SOUTHERN HIGH PLAINS THIS AFTERNOON. ONLY ISOLATED THUNDERSTORMS
HAVE DEVELOPED THUS FAR WITH THIS WAVE OVER SOUTHWEST TEXAS...WHILE
SOLUTIONS REMAIN DECIDEDLY MIXED REGARDING HOW MUCH DEVELOPMENT MAY
OCCUR ACROSS THE TEXAS SOUTH PLAINS REGION LATER THIS MORNING. THE
LATEST WRF/NAM APPEARS QUITE SHOWERY BY MID MORNING INTO THE
AFTERNOON WITH WANING ACTIVITY INTO THE EVENING OWING TO A MORE
STABLE ENVIRONMENT...WHILE THE LATEST RAP ON THE OTHER HAND DELAYS
THE RELEASE OF CONVECTIVE ENERGY UNTIL AFTER NOON WHEN THUNDERSTORMS
EXPLODE ALONG THE SURFACE DRY-LINE FROM THE WESTERN SOUTH PLAINS
INTO THE SOUTHERN PANHANDLE. WHAT SEEMS CERTAIN IS THAT THE CLOUDS
WILL SPREAD OVER THE AREA HOLDING TEMPERATURES DOWN INTO THE
AFTERNOON. ALSO...IT SEEMS PLAUSIBLE THAT AT LEAST LIGHT SHOWERS AND
PERHAPS A FEW THUNDERSTORMS WILL SPREAD UP INTO THE AREA LATER IN
THE MORNING...THOUGH COVERAGE OF THIS ACTIVITY IS HIGHLY UNCERTAIN.
THEREFORE...WE REMAIN LESS CONFIDENT HOW THIS MAY IMPACT REMAINING
CONVECTIVE ENERGY LATER TODAY. WE HAVE SOMEWHAT SPLIT BETWEEN THE
POSSIBLE CHOICES...HOLDING CHANCES LOW THIS MORNING THOUGH RETAINING
MODEST CHANCES FOR SEVERE STORMS THIS AFTERNOON AND EVENING. THE
MAXIMUM POTENTIAL ENERGY AND SHEAR PROFILES LATER TODAY CERTAINLY
SUGGEST OPPORTUNITY FOR AT LEAST A FEW SUPERCELLS WITH LARGE OR EVEN
VERY LARGE HAIL POTENTIAL...WHILE HELICITY LEVELS AND CONVERGENCE
ALONG THE DRY-LINE WOULD OFFER ISOLATED TORNADO THREAT AS WELL WITH
LIFTED CONDENSATION LEVELS POSSIBLY AS LOW AS 3000-6000 FEET. GIVEN
THIS POTENTIAL WITH OUR REDUCED CONFIDENCE...WE THINK IT MAY BE BEST
TO LEAN A BIT TOWARDS THE WORSER OUTCOME UNTIL CLARITY IMPROVES. WE
INCREASED CHANCES SLIGHTLY TODAY AND TONIGHT...RETAINING SEVERE
MENTION DURING THE AFTERNOON AND EVENING. MINOR CHANGES FOR MAJORITY
OF GRID FIELDS. RMCQUEEN
LONG TERM...
WEDNESDAY STILL APPEARS TO HAVE THE POTENTIAL FOR A REGIONAL
SEVERE WEATHER OUTBREAK ACROSS THE ROLLING PLAINS INTO THE EASTERN
TEXAS PANHANDLE AND OKLAHOMA. THE DRYLINE WILL MIX EAST ON
WEDNESDAY BUT UNCERTAINTY REMAINS WITH HOW FAR THE DRYLINE WILL
MOVE. THE UPPER LEVEL NEGATIVELY TILTED TROUGH AXIS WILL PASS OVER
WEST TEXAS MIDDAY ON WEDNESDAY. UNTIL THIS POINT...WEST TEXAS WILL
BE UNDER THE INFLUENCE OF THE FAVORABLE EAST SIDE OF THE
TROUGH/UPPER LEVEL JET. ISENTROPIC LIFT WILL BEGIN TO PROVIDE LIFT
BEGINNING EARLY IN THE EVENING WITH THE INCREASING LOW LEVEL JET.
SURFACE INSTABILITY WILL LIKELY BECOME UNCAPPED IN THE AFTERNOON
WITH PROGGED CAPE VALUES CRESTING AT 3000-3500 J/KG. INCREASING
DEEP LAYER SHEAR WILL BE SUPPORTIVE OF ROTATING SUPERCELLS.
DISCRETE SUPERCELLS WILL LIKELY BE THE FAVORED MODE OF CONVECTION
WITH SHEAR VECTORS NEARLY NORMAL TO THE DRYLINE.
SUBSIDENCE WILL BEGIN TO SPREAD OVER THE REGION WEDNESDAY NIGHT AS
WELL AS ASSOCIATED HEIGHT RISES. THIS WILL PERSIST THROUGH THE DAY
ON FRIDAY KEEPING THURSDAY AND FRIDAY MOSTLY DRY. BY LATE ON
FRIDAY OR EARLY SATURDAY A COLD FRONT WILL MAKE A RUN AT THE AREA
WHICH MAY BRING THE NEXT CHANCE OF SHOWERS AND THUNDERSTORMS.
THERE EXISTS A LACK OF CONFIDENCE IN THE MODEL SOLUTIONS AT THE
MOMENT IN REGARDS TO WHERE THE FRONT WILL STALL OUT.
NONETHELESS...HEAVY RAIN MAY BE A POSSIBILITY WHEREVER THE FRONT
DOES BECOME STATIONARY. JDV
FIRE WEATHER...
A DRYLINE WILL MOVE EAST ON WEDNESDAY AFTERNOON TO THE EDGE OF THE
CAPROCK. THIS WILL LEAD TO VERY DRY CONDITIONS ON THE SOUTH
PLAINS BOTH AFTERNOONS. DEEP MIXING WILL PRODUCE BREEZY WINDS ON
WEDNESDAY AFTERNOON WHICH WILL LEAD TO ELEVATED TO PERHAPS BRIEFLY
CRITICAL FIRE WEATHER CONDITIONS. THIS DRYLINE WILL MOVE EVEN
FARTHER EAST ON THURSDAY SPAWNING A LARGER CRITICAL AREA ON
THURSDAY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 94 65 92 58 93 / 20 30 20 0 0
TULIA 89 67 89 59 92 / 40 30 20 10 0
PLAINVIEW 88 67 90 61 94 / 40 30 20 10 0
LEVELLAND 91 68 93 61 95 / 40 30 20 10 0
LUBBOCK 88 68 92 64 95 / 40 30 20 10 0
DENVER CITY 94 68 93 60 96 / 30 30 20 0 0
BROWNFIELD 91 69 93 63 96 / 40 30 20 10 0
CHILDRESS 87 69 86 69 95 / 40 30 40 30 10
SPUR 87 69 88 68 95 / 40 30 30 20 10
ASPERMONT 86 71 87 72 94 / 40 30 40 30 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1056 AM CDT TUE MAY 28 2013
.UPDATE...
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE TO MOVE EAST
ACROSS THE BIG COUNTRY AND CONCHO VALLEY THIS MORNING AS THE LOW
LEVEL JET INTERACTS WITH A MODERATELY UNSTABLE ENVIRONMENT. THIS
ACTIVITY WILL REMAIN GENERALLY WEAK BUT WILL WORK TO KEEP TEMPS IN
THE 70S FOR A FEW MORE HOURS. HOW THIS AFFECTS AFTERNOON/EVENING
CONVECTION CHANCES REMAINS TO BE SEEN AS SURFACE BASED INSTABILITY
WILL BE LIMITED AND THE CAP MAY BE DIFFICULT TO OVERCOME. THAT
SAID...IF WE GET A FEW HOURS OF HEATING...IT SHOULD NOT BE THAT
BIG OF AN ISSUE. THIS WOULD PUT THE GREATEST THREAT FOR DIURNAL
CONVECTION OVER THE CONCHO VALLEY AND EDWARDS PLATEAU WHERE THE
GREATEST HEATING IS EXPECTED TO OCCUR. WILL CONTINUE TO WATCH THE
RADAR TRENDS THROUGHOUT THE DAY AS THIS SITUATION EVOLVES. THE
FORECAST HAS BEEN UPDATED TO LOWER MAX TEMPS AND EXPAND POPS
FARTHER EAST. OTHERWISE...MOST CHANGES WERE RELATIVELY MINOR.
JOHNSON
&&
.PREV DISCUSSION... /ISSUED 645 AM CDT TUE MAY 28 2013/
DISCUSSION...
SEE 12Z AVIATION DISCUSSION BELOW.
AVIATION...
STRATUS HAS BEEN RATHER SPORADIC THIS MORNING DUE TO ABUNDANT
HIGH CLOUDS STREAMING IN FROM THE SOUTHWEST. WILL HANDLE MVFR
CIGS WITH TEMPO GROUPS THIS MORNING WITH PREDOMINANT VFR EXPECTED
ACROSS THE TERMINALS BY AFTERNOON. WIDELY SCATTERED CONVECTION HAS
FORMED WEST OF THE AREA THE PAST COUPLE OF HOURS. THE MOST LIKELY
TERMINAL TO BE AFFECT BY THIS ACTIVITY IS KSJT AND HAVE INCLUDED
A TEMPO GROUP FOR THUNDER UNTIL 14Z. ADDITIONAL THUNDERSTORMS ARE
EXPECTED TO DEVELOP WEST OF THE TERMINALS LATE THIS AFTERNOON WITH
ACTIVITY POSSIBLY SPREADING ACROSS THE AREA THIS EVENING. NORTHERN
TERMINALS HAVE THE BEST CHANCE TO SEE CONVECTION BUT DUE TO TIMING
AND COVERAGE UNCERTAINTY WILL NOT MENTION AT THIS TIME. MVFR CIGS
RETURN TO THE TERMINALS LATE TONIGHT INTO THURSDAY MORNING.
PREV DISCUSSION... /ISSUED 544 AM CDT TUE MAY 28 2013/
UPDATE...
FORECAST WAS UPDATED TO ADD POPS THIS MORNING.
DISCUSSION...
ELEVATED CONVECTION HAS FORMED OVER THE TRANS PECOS REGION EARLY
THIS MORNING...MOST LIKELY DUE TO AN EMBEDDED DISTURBANCE IN THE
FLOW ALOFT. LATEST HRRR SEEMS TO HAVE THE BEST HANDLE ON THIS
ACTIVITY AND EXPANDS IT AS IT MOVES NORTHEAST ACROSS THE AREA
THROUGH THE MORNING HOURS. SHOULD SEE A WEAKENING TREND THOUGH
BUT DID ADD MENTIONABLE POPS THIS MORNING MAINLY WEST OF A
THROCKMORTON...TO MILLERSVIEW...TO OZONA LINE. NO OTHER CHANGES
WERE MADE.
PREV DISCUSSION... /ISSUED 359 AM CDT TUE MAY 28 2013/
SHORT TERM...
THROUGH TONIGHT..
THE MAIN CONCERN IN THE SHORT TERM PERIOD WILL BE THUNDERSTORM
CHANCES AND THE POSSIBILITY OF A FEW STRONG TO SEVERE STORMS
MAINLY ACROSS WESTERN SECTIONS THIS EVENING AND OVERNIGHT.
AN UPPER TROUGH CURRENTLY CROSSING THE GREAT BASIN REGION WILL
AMPLIFY ACROSS THE CENTRAL AND SOUTHERN ROCKIES LATER TODAY. LEE
SURFACE LOW WILL RESULT IN A TIGHTENING PRESSURE GRADIENT AGAIN
TODAY WITH GUSTY SOUTH WINDS CONTINUING. MUCH LIKE YESTERDAY...LOW
CLOUDS WILL OVERSPREAD MUCH OF THE AREA BY DAYBREAK BUT SHOULD
BEGIN TO SCATTER OUT BY LATE MORNING. THE DRYLINE WILL SETUP
ACROSS FAR WEST TEXAS THIS AFTERNOON AND WILL AGAIN BE THE FOCUS
FOR THUNDERSTORM DEVELOPMENT. STORMS THAT DEVELOP WILL LIKELY
BECOME SEVERE GIVEN MODERATE INSTABILITY AND ADEQUATE DEEP LAYER
SHEAR.
CURRENT THINKING IS THAT MOST OF THIS ACTIVITY WILL REMAIN WEST OF
THE AREA THROUGH LATE AFTERNOON BUT WILL PROPAGATE NORTHEAST
TOWARDS OUR WESTERN COUNTIES DURING THE EVENING HOURS. ADDITIONAL
STORMS MAY DEVELOP ALONG THE RETREATING DRYLINE THIS EVENING AND
MOVE TOWARDS THE AREA DURING THE OVERNIGHT PERIOD. HIGHEST POPS
WERE ORIENTED NORTH AND WEST OF A HASKEL...TO SAN ANGELO...TO
OZONA LINE THIS EVENING AND OVERNIGHT. THE MAIN SEVERE WEATHER
HAZARDS WILL BE LARGE HAIL AND DAMAGING STRAIGHT LINE WINDS. HIGH
TEMPERATURES TODAY WILL BE MAINLY IN THE UPPER 80S WITH LOWS
TONIGHT IN THE LOWER 70S.
24
LONG TERM...
THE MAIN HIGHLIGHTS IN THE EXTENDED FORECAST ARE A CHANCE OF
SEVERE WEATHER ACROSS MUCH OF THE AREA WEDNESDAY...FOLLOWED BY
INCREASING RAIN CHANCES THIS WEEKEND WITH A COLD FRONT. A LARGE
UPPER LEVEL TROUGH WILL BE APPROACHING WEST CENTRAL TEXAS
WEDNESDAY. ALTHOUGH A FEW STORMS COULD BE ONGOING DURING THE EARLY
MORNING HOURS...FROM ANY OVERNIGHT CONVECTION ...I BELIEVE THAT
MOST OF THE CONVECTION ON WEDNESDAY WILL BE DURING THE LATE
AFTERNOON AND EARLY EVENING HOURS. THE DRYLINE WILL SHARPEN AND
MIGRATE TOWARD OUR WESTERN BORDER BY MID AFTERNOON. AS THE UPPER
LEVEL TROUGH APPROACHES...LARGE SCALE LIFT WILL AID IN
THUNDERSTORM DEVELOPMENT ALONG AND EAST OF THE DRYLINE...
ESPECIALLY ACROSS THE BIG COUNTRY. A FAIRLY UNSTABLE ATMOSPHERE
COMBINED WITH 0-6 KM BULK SHEAR VALUES BETWEEN 35 AND 50
KNOTS...MAY RESULT IN A FEW STRONG TO SEVERE THUNDERSTORMS...
ESPECIALLY ACROSS THE BIG COUNTRY. ALTHOUGH LARGE HAIL AND
DAMAGING WINDS WILL BE THE MAIN CONCERNS...AN ISOLATED TORNADO
CANNOT BE RULED OUT. CONVECTION SHOULD CONTINUE INTO THE EVENING
HOURS AND MOVE FROM WEST TO EAST...EVENTUALLY MOVING EAST OF THE
REGION DURING THE EARLY MORNING HOURS. HIGH TEMPERATURES WILL BE
NEAR NORMAL...GENERALLY IN THE MID TO UPPER 80S...WITH LOW
TEMPERATURES NEAR 70.
DRIER AND WARMER CONDITIONS ARE FORECAST BOTH THURSDAY AND
FRIDAY...WITH HIGHS GENERALLY IN THE 90S AND LOWS NEAR 70. MODELS
ARE INDICATING THE NEXT UPPER LEVEL LOW/TROUGH MOVING ACROSS THE
NORTHERN AND CENTRAL PLAINS LATE FRIDAY AND SATURDAY. THIS WILL
SEND A LATE SEASON COLD FRONT INTO WEST CENTRAL TEXAS LATE
SATURDAY OR EARLY SUNDAY. SCATTERED SHOWERS AND THUNDERSTORMS WILL
BE POSSIBLE IN ASSOCIATION WITH THE FRONT...MAINLY LATE SATURDAY
TROUGH SUNDAY. SLOW MOVING...LATE SEASON COLD FRONTS LIKE THIS ONE
HAVE HAD A HISTORY OF PRODUCING MUCH NEEDED RAINFALL ACROSS WEST
CENTRAL TEXAS. IT IS A BIT TOO EARLY TO DECIPHER EXACTLY WHERE THE
FRONT WILL STALL...AND HOW MUCH CONVECTION WILL DEVELOP...BUT THE
DETAILS SHOULD BECOME MORE CLEAR IN THE NEXT COUPLE OF DAYS.
DANIELS
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 86 71 85 71 91 / 30 30 30 30 10
SAN ANGELO 88 72 88 70 94 / 20 20 30 20 10
JUNCTION 86 73 85 72 90 / 10 20 20 20 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
25
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
712 AM CDT TUE MAY 28 2013
.AVIATION...
INITIAL SHOWERS SPREADING NORTHEAST THROUGH PERMIAN BASIN SEEM
UNLIKELY TO SPREAD INTO EITHER TAF SITE...AT LEAST NEXT FEW HOURS.
SHOULD THESE SHOWERS STAY AWAY...THE CHANCES FOR STRONG OR SEVERE
THUNDERSTORMS WOULD INCREASE LATER THIS AFTERNOON AND EVENING.
LATEST TAF PACKAGE BASICALLY FOLLOWS THIS PLAN RETAINING BEST
THUNDER CHANCES FOR LATE IN THE DAY. A NEAR MVFR STRATUS LAYER IS
STILL EXPECTED TO SPREAD CLOSE TO KCDS BY LATE MORNING AS WELL...
THOUGH CEILING REMAINS DOUBTFUL. LOW LEVEL SOUTH TO SOUTHEAST FLOW
WILL STRENGTHEN LATER THIS MORNING AND AFTERNOON. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 354 AM CDT TUE MAY 28 2013/
SHORT TERM...
CONSIDERABLE MID AND UPPER LEVEL MOISTURE WAS SPREADING INTO THE
AREA FROM THE SOUTHWEST ASSOCIATED WITH A WAVE LIFTING OUT ACROSS
THE SOUTHERN HIGH PLAINS THIS AFTERNOON. ONLY ISOLATED THUNDERSTORMS
HAVE DEVELOPED THUS FAR WITH THIS WAVE OVER SOUTHWEST TEXAS...WHILE
SOLUTIONS REMAIN DECIDEDLY MIXED REGARDING HOW MUCH DEVELOPMENT MAY
OCCUR ACROSS THE TEXAS SOUTH PLAINS REGION LATER THIS MORNING. THE
LATEST WRF/NAM APPEARS QUITE SHOWERY BY MID MORNING INTO THE
AFTERNOON WITH WANING ACTIVITY INTO THE EVENING OWING TO A MORE
STABLE ENVIRONMENT...WHILE THE LATEST RAP ON THE OTHER HAND DELAYS
THE RELEASE OF CONVECTIVE ENERGY UNTIL AFTER NOON WHEN THUNDERSTORMS
EXPLODE ALONG THE SURFACE DRY-LINE FROM THE WESTERN SOUTH PLAINS
INTO THE SOUTHERN PANHANDLE. WHAT SEEMS CERTAIN IS THAT THE CLOUDS
WILL SPREAD OVER THE AREA HOLDING TEMPERATURES DOWN INTO THE
AFTERNOON. ALSO...IT SEEMS PLAUSIBLE THAT AT LEAST LIGHT SHOWERS AND
PERHAPS A FEW THUNDERSTORMS WILL SPREAD UP INTO THE AREA LATER IN
THE MORNING...THOUGH COVERAGE OF THIS ACTIVITY IS HIGHLY UNCERTAIN.
THEREFORE...WE REMAIN LESS CONFIDENT HOW THIS MAY IMPACT REMAINING
CONVECTIVE ENERGY LATER TODAY. WE HAVE SOMEWHAT SPLIT BETWEEN THE
POSSIBLE CHOICES...HOLDING CHANCES LOW THIS MORNING THOUGH RETAINING
MODEST CHANCES FOR SEVERE STORMS THIS AFTERNOON AND EVENING. THE
MAXIMUM POTENTIAL ENERGY AND SHEAR PROFILES LATER TODAY CERTAINLY
SUGGEST OPPORTUNITY FOR AT LEAST A FEW SUPERCELLS WITH LARGE OR EVEN
VERY LARGE HAIL POTENTIAL...WHILE HELICITY LEVELS AND CONVERGENCE
ALONG THE DRY-LINE WOULD OFFER ISOLATED TORNADO THREAT AS WELL WITH
LIFTED CONDENSATION LEVELS POSSIBLY AS LOW AS 3000-6000 FEET. GIVEN
THIS POTENTIAL WITH OUR REDUCED CONFIDENCE...WE THINK IT MAY BE BEST
TO LEAN A BIT TOWARDS THE WORSER OUTCOME UNTIL CLARITY IMPROVES. WE
INCREASED CHANCES SLIGHTLY TODAY AND TONIGHT...RETAINING SEVERE
MENTION DURING THE AFTERNOON AND EVENING. MINOR CHANGES FOR MAJORITY
OF GRID FIELDS. RMCQUEEN
LONG TERM...
WEDNESDAY STILL APPEARS TO HAVE THE POTENTIAL FOR A REGIONAL
SEVERE WEATHER OUTBREAK ACROSS THE ROLLING PLAINS INTO THE EASTERN
TEXAS PANHANDLE AND OKLAHOMA. THE DRYLINE WILL MIX EAST ON
WEDNESDAY BUT UNCERTAINTY REMAINS WITH HOW FAR THE DRYLINE WILL
MOVE. THE UPPER LEVEL NEGATIVELY TILTED TROUGH AXIS WILL PASS OVER
WEST TEXAS MIDDAY ON WEDNESDAY. UNTIL THIS POINT...WEST TEXAS WILL
BE UNDER THE INFLUENCE OF THE FAVORABLE EAST SIDE OF THE
TROUGH/UPPER LEVEL JET. ISENTROPIC LIFT WILL BEGIN TO PROVIDE LIFT
BEGINNING EARLY IN THE EVENING WITH THE INCREASING LOW LEVEL JET.
SURFACE INSTABILITY WILL LIKELY BECOME UNCAPPED IN THE AFTERNOON
WITH PROGGED CAPE VALUES CRESTING AT 3000-3500 J/KG. INCREASING
DEEP LAYER SHEAR WILL BE SUPPORTIVE OF ROTATING SUPERCELLS.
DISCRETE SUPERCELLS WILL LIKELY BE THE FAVORED MODE OF CONVECTION
WITH SHEAR VECTORS NEARLY NORMAL TO THE DRYLINE.
SUBSIDENCE WILL BEGIN TO SPREAD OVER THE REGION WEDNESDAY NIGHT AS
WELL AS ASSOCIATED HEIGHT RISES. THIS WILL PERSIST THROUGH THE DAY
ON FRIDAY KEEPING THURSDAY AND FRIDAY MOSTLY DRY. BY LATE ON
FRIDAY OR EARLY SATURDAY A COLD FRONT WILL MAKE A RUN AT THE AREA
WHICH MAY BRING THE NEXT CHANCE OF SHOWERS AND THUNDERSTORMS.
THERE EXISTS A LACK OF CONFIDENCE IN THE MODEL SOLUTIONS AT THE
MOMENT IN REGARDS TO WHERE THE FRONT WILL STALL OUT.
NONETHELESS...HEAVY RAIN MAY BE A POSSIBILITY WHEREVER THE FRONT
DOES BECOME STATIONARY. JDV
FIRE WEATHER...
A DRYLINE WILL MOVE EAST ON WEDNESDAY AFTERNOON TO THE EDGE OF THE
CAPROCK. THIS WILL LEAD TO VERY DRY CONDITIONS ON THE SOUTH
PLAINS BOTH AFTERNOONS. DEEP MIXING WILL PRODUCE BREEZY WINDS ON
WEDNESDAY AFTERNOON WHICH WILL LEAD TO ELEVATED TO PERHAPS BRIEFLY
CRITICAL FIRE WEATHER CONDITIONS. THIS DRYLINE WILL MOVE EVEN
FARTHER EAST ON THURSDAY SPAWNING A LARGER CRITICAL AREA ON
THURSDAY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 92 65 92 58 93 / 20 30 20 0 0
TULIA 89 67 89 59 92 / 40 30 20 10 0
PLAINVIEW 88 67 90 61 94 / 40 30 20 10 0
LEVELLAND 91 68 93 61 95 / 40 30 20 10 0
LUBBOCK 88 68 92 65 95 / 40 30 20 10 0
DENVER CITY 94 68 93 60 96 / 30 30 20 0 0
BROWNFIELD 91 69 93 63 96 / 40 30 20 10 0
CHILDRESS 89 69 86 69 95 / 40 30 40 30 10
SPUR 87 69 88 68 95 / 40 30 30 20 10
ASPERMONT 88 71 87 72 94 / 40 30 40 30 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/05
AREA FORECAST DISCUSSION...UPDATED
NWS SAN ANGELO TX
544 AM CDT TUE MAY 28 2013
.UPDATE...
FORECAST WAS UPDATED TO ADD POPS THIS MORNING.
&&
.DISCUSSION...
ELEVATED CONVECTION HAS FORMED OVER THE TRANS PECOS REGION EARLY
THIS MORNING...MOST LIKELY DUE TO AN EMBEDDED DISTURBANCE IN THE
FLOW ALOFT. LATEST HRRR SEEMS TO HAVE THE BEST HANDLE ON THIS
ACTIVITY AND EXPANDS IT AS IT MOVES NORTHEAST ACROSS THE AREA
THROUGH THE MORNING HOURS. SHOULD SEE A WEAKENING TREND THOUGH
BUT DID ADD MENTIONABLE POPS THIS MORNING MAINLY WEST OF A
THROCKMORTON...TO MILLERSVIEW...TO OZONA LINE. NO OTHER CHANGES
WERE MADE.
&&
.PREV DISCUSSION... /ISSUED 359 AM CDT TUE MAY 28 2013/
SHORT TERM...
.THROUGH TONIGHT..
THE MAIN CONCERN IN THE SHORT TERM PERIOD WILL BE THUNDERSTORM
CHANCES AND THE POSSIBILITY OF A FEW STRONG TO SEVERE STORMS MAINLY
ACROSS WESTERN SECTIONS THIS EVENING AND OVERNIGHT.
AN UPPER TROUGH CURRENTLY CROSSING THE GREAT BASIN REGION WILL
AMPLIFY ACROSS THE CENTRAL AND SOUTHERN ROCKIES LATER TODAY. LEE
SURFACE LOW WILL RESULT IN A TIGHTENING PRESSURE GRADIENT AGAIN
TODAY WITH GUSTY SOUTH WINDS CONTINUING. MUCH LIKE YESTERDAY...LOW
CLOUDS WILL OVERSPREAD MUCH OF THE AREA BY DAYBREAK BUT SHOULD BEGIN
TO SCATTER OUT BY LATE MORNING. THE DRYLINE WILL SETUP ACROSS FAR
WEST TEXAS THIS AFTERNOON AND WILL AGAIN BE THE FOCUS FOR
THUNDERSTORM DEVELOPMENT. STORMS THAT DEVELOP WILL LIKELY BECOME
SEVERE GIVEN MODERATE INSTABILITY AND ADEQUATE DEEP LAYER SHEAR.
CURRENT THINKING IS THAT MOST OF THIS ACTIVITY WILL REMAIN WEST OF
THE AREA THROUGH LATE AFTERNOON BUT WILL PROPAGATE NORTHEAST TOWARDS
OUR WESTERN COUNTIES DURING THE EVENING HOURS. ADDITIONAL STORMS MAY
DEVELOP ALONG THE RETREATING DRYLINE THIS EVENING AND MOVE TOWARDS
THE AREA DURING THE OVERNIGHT PERIOD. HIGHEST POPS WERE ORIENTED
NORTH AND WEST OF A HASKEL...TO SAN ANGELO...TO OZONA LINE THIS
EVENING AND OVERNIGHT. THE MAIN SEVERE WEATHER HAZARDS WILL BE
LARGE HAIL AND DAMAGING STRAIGHT LINE WINDS. HIGH TEMPERATURES TODAY
WILL BE MAINLY IN THE UPPER 80S WITH LOWS TONIGHT IN THE LOWER
70S.
24
LONG TERM...
THE MAIN HIGHLIGHTS IN THE EXTENDED FORECAST ARE A CHANCE OF SEVERE
WEATHER ACROSS MUCH OF THE AREA WEDNESDAY...FOLLOWED BY INCREASING
RAIN CHANCES THIS WEEKEND WITH A COLD FRONT. A LARGE UPPER LEVEL
TROUGH WILL BE APPROACHING WEST CENTRAL TEXAS WEDNESDAY. ALTHOUGH A
FEW STORMS COULD BE ONGOING DURING THE EARLY MORNING HOURS...FROM
ANY OVERNIGHT CONVECTION ...I BELIEVE THAT MOST OF THE CONVECTION ON
WEDNESDAY WILL BE DURING THE LATE AFTERNOON AND EARLY EVENING HOURS.
THE DRYLINE WILL SHARPEN AND MIGRATE TOWARD OUR WESTERN BORDER BY
MID AFTERNOON. AS THE UPPER LEVEL TROUGH APPROACHES...LARGE SCALE
LIFT WILL AID IN THUNDERSTORM DEVELOPMENT ALONG AND EAST OF THE
DRYLINE...ESPECIALLY ACROSS THE BIG COUNTRY. A FAIRLY UNSTABLE
ATMOSPHERE COMBINED WITH 0-6 KM BULK SHEAR VALUES BETWEEN 35 AND 50
KNOTS...MAY RESULT IN A FEW STRONG TO SEVERE
THUNDERSTORMS...ESPECIALLY ACROSS THE BIG COUNTRY. ALTHOUGH LARGE
HAIL AND DAMAGING WINDS WILL BE THE MAIN CONCERNS...AN ISOLATED
TORNADO CANNOT BE RULED OUT. CONVECTION SHOULD CONTINUE INTO THE
EVENING HOURS AND MOVE FROM WEST TO EAST...EVENTUALLY MOVING EAST OF
THE REGION DURING THE EARLY MORNING HOURS. HIGH TEMPERATURES WILL BE
NEAR NORMAL...GENERALLY IN THE MID TO UPPER 80S...WITH LOW
TEMPERATURES NEAR 70.
DRIER AND WARMER CONDITIONS ARE FORECAST BOTH THURSDAY AND
FRIDAY...WITH HIGHS GENERALLY IN THE 90S AND LOWS NEAR 70. MODELS
ARE INDICATING THE NEXT UPPER LEVEL LOW/TROUGH MOVING ACROSS THE
NORTHERN AND CENTRAL PLAINS LATE FRIDAY AND SATURDAY. THIS WILL SEND
A LATE SEASON COLD FRONT INTO WEST CENTRAL TEXAS LATE SATURDAY OR
EARLY SUNDAY. SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
IN ASSOCIATION WITH THE FRONT...MAINLY LATE SATURDAY TROUGH SUNDAY.
SLOW MOVING...LATE SEASON COLD FRONTS LIKE THIS ONE HAVE HAD A
HISTORY OF PRODUCING MUCH NEEDED RAINFALL ACROSS WEST CENTRAL TEXAS.
IT IS A BIT TOO EARLY TO DECIPHER EXACTLY WHERE THE FRONT WILL
STALL...AND HOW MUCH CONVECTION WILL DEVELOP...BUT THE DETAILS
SHOULD BECOME MORE CLEAR IN THE NEXT COUPLE OF DAYS.
DANIELS
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 88 71 85 71 91 / 20 30 30 30 10
SAN ANGELO 89 72 88 70 94 / 20 20 30 20 10
JUNCTION 87 73 85 72 90 / 10 20 20 20 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
354 AM CDT TUE MAY 28 2013
.SHORT TERM...
CONSIDERABLE MID AND UPPER LEVEL MOISTURE WAS SPREADING INTO THE
AREA FROM THE SOUTHWEST ASSOCIATED WITH A WAVE LIFTING OUT ACROSS
THE SOUTHERN HIGH PLAINS THIS AFTERNOON. ONLY ISOLATED THUNDERSTORMS
HAVE DEVELOPED THUS FAR WITH THIS WAVE OVER SOUTHWEST TEXAS...WHILE
SOLUTIONS REMAIN DECIDEDLY MIXED REGARDING HOW MUCH DEVELOPMENT MAY
OCCUR ACROSS THE TEXAS SOUTH PLAINS REGION LATER THIS MORNING. THE
LATEST WRF/NAM APPEARS QUITE SHOWERY BY MID MORNING INTO THE
AFTERNOON WITH WANING ACTIVITY INTO THE EVENING OWING TO A MORE
STABLE ENVIRONMENT...WHILE THE LATEST RAP ON THE OTHER HAND DELAYS
THE RELEASE OF CONVECTIVE ENERGY UNTIL AFTER NOON WHEN THUNDERSTORMS
EXPLODE ALONG THE SURFACE DRY-LINE FROM THE WESTERN SOUTH PLAINS
INTO THE SOUTHERN PANHANDLE. WHAT SEEMS CERTAIN IS THAT THE CLOUDS
WILL SPREAD OVER THE AREA HOLDING TEMPERATURES DOWN INTO THE
AFTERNOON. ALSO...IT SEEMS PLAUSIBLE THAT AT LEAST LIGHT SHOWERS AND
PERHAPS A FEW THUNDERSTORMS WILL SPREAD UP INTO THE AREA LATER IN
THE MORNING...THOUGH COVERAGE OF THIS ACTIVITY IS HIGHLY UNCERTAIN.
THEREFORE...WE REMAIN LESS CONFIDENT HOW THIS MAY IMPACT REMAINING
CONVECTIVE ENERGY LATER TODAY. WE HAVE SOMEWHAT SPLIT BETWEEN THE
POSSIBLE CHOICES...HOLDING CHANCES LOW THIS MORNING THOUGH RETAINING
MODEST CHANCES FOR SEVERE STORMS THIS AFTERNOON AND EVENING. THE
MAXIMUM POTENTIAL ENERGY AND SHEAR PROFILES LATER TODAY CERTAINLY
SUGGEST OPPORTUNITY FOR AT LEAST A FEW SUPERCELLS WITH LARGE OR EVEN
VERY LARGE HAIL POTENTIAL...WHILE HELICITY LEVELS AND CONVERGENCE
ALONG THE DRY-LINE WOULD OFFER ISOLATED TORNADO THREAT AS WELL WITH
LIFTED CONDENSATION LEVELS POSSIBLY AS LOW AS 3000-6000 FEET. GIVEN
THIS POTENTIAL WITH OUR REDUCED CONFIDENCE...WE THINK IT MAY BE BEST
TO LEAN A BIT TOWARDS THE WORSER OUTCOME UNTIL CLARITY IMPROVES. WE
INCREASED CHANCES SLIGHTLY TODAY AND TONIGHT...RETAINING SEVERE
MENTION DURING THE AFTERNOON AND EVENING. MINOR CHANGES FOR MAJORITY
OF GRID FIELDS. RMCQUEEN
&&
.LONG TERM...
WEDNESDAY STILL APPEARS TO HAVE THE POTENTIAL FOR A REGIONAL
SEVERE WEATHER OUTBREAK ACROSS THE ROLLING PLAINS INTO THE EASTERN
TEXAS PANHANDLE AND OKLAHOMA. THE DRYLINE WILL MIX EAST ON
WEDNESDAY BUT UNCERTAINTY REMAINS WITH HOW FAR THE DRYLINE WILL
MOVE. THE UPPER LEVEL NEGATIVELY TILTED TROUGH AXIS WILL PASS OVER
WEST TEXAS MIDDAY ON WEDNESDAY. UNTIL THIS POINT...WEST TEXAS WILL
BE UNDER THE INFLUENCE OF THE FAVORABLE EAST SIDE OF THE
TROUGH/UPPER LEVEL JET. ISENTROPIC LIFT WILL BEGIN TO PROVIDE LIFT
BEGINNING EARLY IN THE EVENING WITH THE INCREASING LOW LEVEL JET.
SURFACE INSTABILITY WILL LIKELY BECOME UNCAPPED IN THE AFTERNOON
WITH PROGGED CAPE VALUES CRESTING AT 3000-3500 J/KG. INCREASING
DEEP LAYER SHEAR WILL BE SUPPORTIVE OF ROTATING SUPERCELLS.
DISCRETE SUPERCELLS WILL LIKELY BE THE FAVORED MODE OF CONVECTION
WITH SHEAR VECTORS NEARLY NORMAL TO THE DRYLINE.
SUBSIDENCE WILL BEGIN TO SPREAD OVER THE REGION WEDNESDAY NIGHT AS
WELL AS ASSOCIATED HEIGHT RISES. THIS WILL PERSIST THROUGH THE DAY
ON FRIDAY KEEPING THURSDAY AND FRIDAY MOSTLY DRY. BY LATE ON
FRIDAY OR EARLY SATURDAY A COLD FRONT WILL MAKE A RUN AT THE AREA
WHICH MAY BRING THE NEXT CHANCE OF SHOWERS AND THUNDERSTORMS.
THERE EXISTS A LACK OF CONFIDENCE IN THE MODEL SOLUTIONS AT THE
MOMENT IN REGARDS TO WHERE THE FRONT WILL STALL OUT.
NONETHELESS...HEAVY RAIN MAY BE A POSSIBILITY WHEREVER THE FRONT
DOES BECOME STATIONARY. JDV
&&
.FIRE WEATHER...
A DRYLINE WILL MOVE EAST ON WEDNESDAY AFTERNOON TO THE EDGE OF THE
CAPROCK. THIS WILL LEAD TO VERY DRY CONDITIONS ON THE SOUTH
PLAINS BOTH AFTERNOONS. DEEP MIXING WILL PRODUCE BREEZY WINDS ON
WEDNESDAY AFTERNOON WHICH WILL LEAD TO ELEVATED TO PERHAPS BRIEFLY
CRITICAL FIRE WEATHER CONDITIONS. THIS DRYLINE WILL MOVE EVEN
FARTHER EAST ON THURSDAY SPAWNING A LARGER CRITICAL AREA ON
THURSDAY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 92 65 92 58 93 / 20 30 20 0 0
TULIA 89 67 89 59 92 / 40 30 20 10 0
PLAINVIEW 88 67 90 61 94 / 40 30 20 10 0
LEVELLAND 91 68 93 61 95 / 40 30 20 10 0
LUBBOCK 88 68 92 64 95 / 40 30 20 10 0
DENVER CITY 94 68 93 60 96 / 30 30 20 0 0
BROWNFIELD 91 69 93 63 96 / 40 30 20 10 0
CHILDRESS 89 69 86 69 95 / 40 30 40 30 10
SPUR 87 69 88 68 95 / 40 30 30 20 10
ASPERMONT 88 71 87 72 94 / 40 30 40 30 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
05/01
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1245 PM EDT TUE MAY 28 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN IN CONTROL OF OUR WEATHER THROUGH THE
WEEK WITH ABOVE NORMAL TEMPERATURES AND ISOLATED CHANCES FOR
STORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1005 AM EDT TUESDAY...
MAIN CONCERN WITH POTENTIAL CONVECTIVE COVERAGE THIS AFTERNOON
AS THE TAIL OF A FAINT IMPULSE MOVES ACROSS FROM WEST OF THE
MOUNTAINS AND COMBINES WITH HEATING AND RETURNING DEEPER MOISTURE.
MODIFIED MORNING SOUNDINGS DO SHOW SOME MODEST CAPE OF 1000-1500
J/KG FROM THE BLUE RIDGE EAST ALTHOUGH APPEARS FOCUS LACKING
HEADING EAST. LATEST HRRR OUTPUT CONTINUES TO SHOW SHRA/TSRA
UNZIPPING ALONG THE BLUE RIDGE FROM SW TO NE AS AIDED BY DIFF
HEATING EARLY AND WEAK CONVERGENCE PER LOW LEVEL WINDS BACKING
MORE SOUTHERLY LATER ON. SIMILAR DEPICTION FROM THE RNK-WRF AND
TO SOME DEGREE THE LATEST NAM SUPPORT AT LEAST A SCATTERING OF
POPS BLUE RIDGE AND POINTS NORTH CLOSER TO THE UPPER SUPPORT AND
PERHAPS LATER OUTFLOW. WILL KEEP IN SLIGHT POPS ESLW FOR A POP UP
STORM OR TWO WITH LEAST COVERAGE SE. ANY SEVERE THREAT WOULD LOOK
TO COME FROM PULSE NATURE STORMS IF CONVECTION CAN GET DEEP ENOUGH
GIVEN STEEP LAPSES AND LOW WET BULB ZERO VALUES THIS AFTERNOON.
MORNING THICKNESS OFF RAOBS SHOW HIGHS WELL INTO THE 70S AND LOWER
80S WEST GIVEN INCREASING INSOLATION AFTER EARLY MID DECK...AND
MOSTLY MID 80S EAST AS A DECENT 85H JET MIXES DOWN SOME OF THE
INVADING WARMER AIR ALOFT.
TONIGHT...ANY CONVECTION WILL GO AWAY AFTER SUNSET WITH SKIES
BECOMING MOSTLY CLEAR. WITH HUMIDITY INCREASING THERE MAY BE A
BETTER CHANCE FOR FOG IN THE MOUNTAINS AND RIVER VALLEYS...AND
WHERE ANY RAIN OCCURS THIS AFTERNOON.
LOWS WILL RANGE FROM THE MID 50S OVER THE MOUNTAIN VALLEYS TO LOWER
60S EAST.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM EDT TUESDAY...
WILL START WEDNESDAY OUT WITH UPPER LEVEL RIDGING ACROSS THE
SOUTHEAST STATES...WHILE A NEGATIVELY TILTED UPPER LEVEL TROUGH DIGS
FROM THE PACIFIC NORTHWEST ALL THE WAY INTO WEST TEXAS. WE MAY SEE A
FEW SHOWERS AND THUNDERSTORMS DEVELOP ALONG OUR MOUNTAINS DURING THE
AFTERNOON AND EVENING...BUT RIDGING ALOFT WILL KEEP THIS ACTIVITY
ISOLATED AND WEAK. RIDGING WILL ALSO ALLOW FOR WARMER AFTERNOON
TEMPERATURES...WITH HIGHS RANGING FROM THE UPPER 70S TO THE MID 80S
ACROSS THE MOUNTAINS...AND NEAR 90 ACROSS THE PIEDMONTS.
THE WEATHER PATTERN WILL REMAIN LITTLE CHANGED THROUGH THE END OF
THE WORKWEEK...WITH UPPER LEVEL RIDGING KEEPING PRECIPITATION
LIMITED TO ISOLATED SHOWERS AND THUNDERSTORMS EACH AFTERNOON AND
EVENING FOR THURSDAY AND FRIDAY...MAINLY ACROSS THE MOUNTAINS. HIGHS
WILL RANGE FROM THE LOW/MID 80S WEST TO THE LOW 90S EAST...WITH
OVERNIGHT LOWS FALLING INTO THE UPPER 50S TO LOW 60S AREAWIDE.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 333 PM EDT MONDAY...
MOST OF THE WEEKEND WILL CONTINUE TO BE HOT AND DRY...WITH DEWPOINTS
INCREASING SOMEWHAT DURING THE SECOND HALF OF THE WEEKEND AS A FRONT
SLOWS THROUGH THE OHIO VALLEY TRYING TO DISPLACE THE UPPER RIDGE.
POSSIBLY BE ABLE TO SQUEAK IN ANOTHER MOSTLY DRY DAY ON SUNDAY WITH
MOST SHOWERS AND STORMS ARRIVING SUNDAY NIGHT AND MONDAY...FOLLOWING
THE 12Z ECMWF TIMING. MOST OF THE SUPPORT FOR THIS BOUNDARY WILL
PASS TO OUR NORTHWEST SUCH THAT THE FRONT MAY SLOW AND DIE OVER THE
REGION NEXT MONDAY. AT THIS POINT...NO SUBSTANTIAL COLD AIR WILL
ARRIVE BEHIND THIS COLD FRONT INTO NEXT WEEK.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 1235 PM EDT TUESDAY...
OVERALL VFR WILL CONTINUE THIS AFTERNOON...ALTHOUGH WILL SEE
SCATTERED TO ISOLATED CONVECTION BUBBLE UP ALONG THE BLUE RIDGE
AND POINTS NORTH ESPCLY BETWEEN KLWB AND KLYH. COVERAGE IS
EXPECTED TO BE SPOTTY WITH LOW CONFIDENCE IN SEEING A SHOWER OR
STORM DIRECTLY AFFECT A SPECIFIC TAF SITE SO WILL MAINTAIN A
VICINITY MENTION FROM KROA/KBCB AND POINTS WEST FOR A FEW HOURS
THIS AFTERNOON. HOWEVER VARIED CONDITIONS WILL EXIST IN AND NEAR
STORMS WITH A QUICK DROPOFF TO MVFR/IFR WITH LOCALLY STRONG WIND
GUSTS POSSIBLE NEAR ANY TSRA.
TONIGHT...ANY CONVECTION DIES OFF AND SKIES CLEAR OUT SOME.
INCREASING LOW LEVEL MOISTURE SHOULD PROMPT AT LEAST SOME PATCHY
FOG ACROSS THE VALLEYS AND MORE WIDESPREAD COVERAGE WHERE EARLIER
SHOWERS MAY HAVE OCCURRED. FOR NOW WILL INCLUDE SOME HIGH END MVFR
FOG MENTION AT THE TYPICAL FOGGY SPOTS LIKE KLWB/KLYH BUT COULD
TREND IFR IN ANY LOCATION THAT SEES A HEAVIER SHOWER FROM THIS
AFTERNOON.
MOIST AND UNSTABLE AIR STAYS AROUND THROUGH THE WEEK. HOWEVER
HEIGHTS WILL BE BUILDING THROUGH LATE WEEK AS THE UPPER RIDGE
STRENGTHENS OVER THE MISSISSIPPI VALLEY. ONLY ISOLATED TO
SCATTERED OROGRAPHIC DRIVEN CONVECTION FOR MID AND LATE WEEK.
PATCHY LATE NIGHT FOG ALSO LIKELY DURING THE OVERNIGHTS ESPCLY
VALLEYS AND WHERE AFTERNOON/EVENING RAINFALL OCCURS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WP
NEAR TERM...JH/WP
SHORT TERM...NF
LONG TERM...KM
AVIATION...JH/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1011 AM EDT TUE MAY 28 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN IN CONTROL OF OUR WEATHER THROUGH THE
WEEK WITH ABOVE NORMAL TEMPERATURES AND ISOLATED CHANCES FOR
STORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1005 AM EDT TUESDAY...
MAIN CONCERN WITH POTENTIAL CONVECTIVE COVERAGE THIS AFTERNOON
AS A FAINT IMPULSE MOVES ACROSS FROM WEST OF THE MOUNTAINS AND
COMBINES WITH HEATING AND RETURNING DEEPER MOISTURE. MODIFIED
MORNING SOUNDINGS DO SHOW SOME MODEST CAPE OF 1000-1500 J/KG FROM
THE BLUE RIDGE EAST ALTHOUGH APPEARS FOCUS LACKING HEADING EAST.
LATEST HRRR OUTPUT CONTINUES TO SHOW SHRA/TSRA UNZIPPING ALONG THE
BLUE RIDGE FROM SW TO NE AS AIDED BY DIFF HEATING EARLY AND WEAK
CONVERGENCE PER LOW LEVEL WINDS TURNING MORE SOUTHERLY LATER ON.
SIMILAR DEPICTION FROM THE RNK-WRF AND TO SOME DEGREE THE LATEST
NAM SUPPORT AT LEAST A SCATTERING OF POPS BLUE RIDGE AND POINTS
NORTH CLOSER TO THE UPPER SUPPORT AND PERHAPS LATER OUTFLOW. WILL
KEEP IN SLIGHT POPS ESLW FOR A POP UP STORM OR TWO WITH LEAST
COVERAGE SE. ANY SEVERE THREAT WOULD LOOK TO COME FROM PULSE
NATURE STORMS IF CONVECTION CAN GET DEEP ENOUGH GIVEN STEEP
LAPSES AND LOW WET BULB ZERO VALUES THIS AFTERNOON. MORNING
THICKNESS OFF RAOBS SHOW HIGHS WELL INTO THE 70S AND LOWER 80S
WEST GIVEN INCREASING INSOLATION AFTER EARLY MID DECK...AND MOSTLY
MID 80S EAST AS A DECENT 85H JET MIXES DOWN SOME OF THE INVADING
WARMER AIR ALOFT.
TONIGHT...ANY CONVECTION WILL GO AWAY AFTER SUNSET WITH SKIES
BECOMING MOSTLY CLEAR. WITH HUMIDITY INCREASING THERE MAY BE A
BETTER CHANCE FOR FOG IN THE MOUNTAINS AND RIVER VALLEYS...AND
WHERE ANY RAIN OCCURS THIS AFTERNOON.
LOWS WILL RANGE FROM THE MID 50S OVER THE MOUNTAIN VALLEYS TO LOWER
60S EAST.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM EDT TUESDAY...
WILL START WEDNESDAY OUT WITH UPPER LEVEL RIDGING ACROSS THE
SOUTHEAST STATES...WHILE A NEGATIVELY TILTED UPPER LEVEL TROUGH DIGS
FROM THE PACIFIC NORTHWEST ALL THE WAY INTO WEST TEXAS. WE MAY SEE A
FEW SHOWERS AND THUNDERSTORMS DEVELOP ALONG OUR MOUNTAINS DURING THE
AFTERNOON AND EVENING...BUT RIDGING ALOFT WILL KEEP THIS ACTIVITY
ISOLATED AND WEAK. RIDGING WILL ALSO ALLOW FOR WARMER AFTERNOON
TEMPERATURES...WITH HIGHS RANGING FROM THE UPPER 70S TO THE MID 80S
ACROSS THE MOUNTAINS...AND NEAR 90 ACROSS THE PIEDMONTS.
THE WEATHER PATTERN WILL REMAIN LITTLE CHANGED THROUGH THE END OF
THE WORKWEEK...WITH UPPER LEVEL RIDGING KEEPING PRECIPITATION
LIMITED TO ISOLATED SHOWERS AND THUNDERSTORMS EACH AFTERNOON AND
EVENING FOR THURSDAY AND FRIDAY...MAINLY ACROSS THE MOUNTAINS. HIGHS
WILL RANGE FROM THE LOW/MID 80S WEST TO THE LOW 90S EAST...WITH
OVERNIGHT LOWS FALLING INTO THE UPPER 50S TO LOW 60S AREAWIDE.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 333 PM EDT MONDAY...
MOST OF THE WEEKEND WILL CONTINUE TO BE HOT AND DRY...WITH DEWPOINTS
INCREASING SOMEWHAT DURING THE SECOND HALF OF THE WEEKEND AS A FRONT
SLOWS THROUGH THE OHIO VALLEY TRYING TO DISPLACE THE UPPER RIDGE.
POSSIBLY BE ABLE TO SQUEAK IN ANOTHER MOSTLY DRY DAY ON SUNDAY WITH
MOST SHOWERS AND STORMS ARRIVING SUNDAY NIGHT AND MONDAY...FOLLOWING
THE 12Z ECMWF TIMING. MOST OF THE SUPPORT FOR THIS BOUNDARY WILL
PASS TO OUR NORTHWEST SUCH THAT THE FRONT MAY SLOW AND DIE OVER THE
REGION NEXT MONDAY. AT THIS POINT...NO SUBSTANTIAL COLD AIR WILL
ARRIVE BEHIND THIS COLD FRONT INTO NEXT WEEK.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
AS OF 725 AM EDT TUESDAY...
GOING TO BE SEEING VFR WEATHER FOR MOST OF THE PERIOD...ALTHOUGH
WILL SEE SCATTERED TO ISOLATED CONVECTION AFTER MIDDAY TODAY
ACROSS THE BLUE RIDGE AND NORTH AND WEST TO WV. COVERAGE WILL BE
SUCH THAT NO EFFECT WILL BE MADE TO THE AVIAITON FORECAST EXCEPT
KEEPING VCTS AT LWB WHERE A BETTER THAN 30 PERCENT CHANCE EXISTS
FOR NOW.
TONIGHT...ANY CONVECTION DIES OFF AND SKIES CLEAR OUT SOME.
ATTM...WILL LEAVE FOG OUT BUT WITH INCREASED MOISTURE IN THE LOW
LVLS AND POTENTIAL FOR SHOWERS...FOG COULD FORM AT THE FAVORED
AIRPORTS LIKE LWB/BCB.
MOIST AND UNSTABLE AIR STAYS AROUND THROUGH THE WEEK. HOWEVER
HEIGHTS WILL BE BUILDING THROUGH LATE WEEK AS THE UPPER RIDGE
STRENGTHENS OVER THE MISSISSIPPI VALLEY. ONLY ISOLATED TO
SCATTERED OROGRAPHIC DRIVEN CONVECTION FOR MID AND LATE WEEK.
PATCHY LATE NIGHT FOG ALSO LIKELY DURING THE OVERNIGHTS ESPCLY
VALLEYS AND WHERE AFTERNOON/EVENING RAINFALL OCCURS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WP
NEAR TERM...JH/WP
SHORT TERM...NF
LONG TERM...KM
AVIATION...WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
958 AM EDT TUE MAY 28 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN IN CONTROL OF OUR WEATHER THROUGH THE
WEEK WITH ABOVE NORMAL TEMPERATURES AND ISOLATED CHANCES FOR
STORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 935 AM EDT TUESDAY...
MAIN CONCERN WITH POTENTIAL CONVECTIVE COVERAGE THIS AFTERNOON
AS A FAINT IMPULSE MOVES ACROSS FROM WEST OF THE MOUNTAINS AND
COMBINES WITH HEATING AND RETURNING DEEPER MOISTURE. MODIFIED
MORNING SOUNDINGS DO SHOW SOME MODEST CAPE OF 1000-1500 J/KG FROM
THE BLUE RIDGE EAST ALTHOUGH APPEARS FOCUS LACKING HEADING EAST.
LATEST HRRR OUTPUT CONTINUES TO SHOW SHRA/TSRA UNZIPPING ALONG THE
BLUE RIDGE FROM SW TO NE AS AIDED BY DIFF HEATING EARLY AND WEAK
CONVERGENCE PER LOW LEVEL WINDS TURNING MORE SOUTHERLY LATER ON.
SIMILAR DEPICTION FROM THE RNK-WRF AND TO SOME DEGREE THE LATEST
NAM SUPPORT AT LEAST A SCATTERING OF POPS BLUE RIDGE AND POINTS
NORTH CLOSER TO THE UPPER SUPPORT AND PERHAPS LATER OUTFLOW. WILL
KEEP IN SLIGHT POPS ESLW FOR A POP UP STORM OR TWO WITH LEAST
COVERAGE SE. MORNING THICKNESS OFF RAOBS SHOW HIGHS WELL INTO THE
70S AND LOWER 80S WEST GIVEN INCREASING INSOLATION AFTER EARLY MID
DECK...AND MOSTLY MID 80S EAST AS A DECENT 85H JET MIXES DOWN
SOME OF THE INVADING WARMER AIR ALOFT.
TONIGHT...ANY CONVECTION WILL GO AWAY AFTER SUNSET WITH SKIES
BECOMING MOSTLY CLEAR. WITH HUMIDITY INCREASING THERE MAY BE A
BETTER CHANCE FOR FOG IN THE MOUNTAINS AND RIVER VALLEYS...AND
WHERE ANY RAIN OCCURS THIS AFTERNOON.
LOWS WILL RANGE FROM THE MID 50S OVER THE MOUNTAIN VALLEYS TO LOWER
60S EAST.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM EDT TUESDAY...
WILL START WEDNESDAY OUT WITH UPPER LEVEL RIDGING ACROSS THE
SOUTHEAST STATES...WHILE A NEGATIVELY TILTED UPPER LEVEL TROUGH DIGS
FROM THE PACIFIC NORTHWEST ALL THE WAY INTO WEST TEXAS. WE MAY SEE A
FEW SHOWERS AND THUNDERSTORMS DEVELOP ALONG OUR MOUNTAINS DURING THE
AFTERNOON AND EVENING...BUT RIDGING ALOFT WILL KEEP THIS ACTIVITY
ISOLATED AND WEAK. RIDGING WILL ALSO ALLOW FOR WARMER AFTERNOON
TEMPERATURES...WITH HIGHS RANGING FROM THE UPPER 70S TO THE MID 80S
ACROSS THE MOUNTAINS...AND NEAR 90 ACROSS THE PIEDMONTS.
THE WEATHER PATTERN WILL REMAIN LITTLE CHANGED THROUGH THE END OF
THE WORKWEEK...WITH UPPER LEVEL RIDGING KEEPING PRECIPITATION
LIMITED TO ISOLATED SHOWERS AND THUNDERSTORMS EACH AFTERNOON AND
EVENING FOR THURSDAY AND FRIDAY...MAINLY ACROSS THE MOUNTAINS. HIGHS
WILL RANGE FROM THE LOW/MID 80S WEST TO THE LOW 90S EAST...WITH
OVERNIGHT LOWS FALLING INTO THE UPPER 50S TO LOW 60S AREAWIDE.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 333 PM EDT MONDAY...
MOST OF THE WEEKEND WILL CONTINUE TO BE HOT AND DRY...WITH DEWPOINTS
INCREASING SOMEWHAT DURING THE SECOND HALF OF THE WEEKEND AS A FRONT
SLOWS THROUGH THE OHIO VALLEY TRYING TO DISPLACE THE UPPER RIDGE.
POSSIBLY BE ABLE TO SQUEAK IN ANOTHER MOSTLY DRY DAY ON SUNDAY WITH
MOST SHOWERS AND STORMS ARRIVING SUNDAY NIGHT AND MONDAY...FOLLOWING
THE 12Z ECMWF TIMING. MOST OF THE SUPPORT FOR THIS BOUNDARY WILL
PASS TO OUR NORTHWEST SUCH THAT THE FRONT MAY SLOW AND DIE OVER THE
REGION NEXT MONDAY. AT THIS POINT...NO SUBSTANTIAL COLD AIR WILL
ARRIVE BEHIND THIS COLD FRONT INTO NEXT WEEK.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
AS OF 725 AM EDT TUESDAY...
GOING TO BE SEEING VFR WEATHER FOR MOST OF THE PERIOD...ALTHOUGH
WILL SEE SCATTERED TO ISOLATED CONVECTION AFTER MIDDAY TODAY
ACROSS THE BLUE RIDGE AND NORTH AND WEST TO WV. COVERAGE WILL BE
SUCH THAT NO EFFECT WILL BE MADE TO THE AVIAITON FORECAST EXCEPT
KEEPING VCTS AT LWB WHERE A BETTER THAN 30 PERCENT CHANCE EXISTS
FOR NOW.
TONIGHT...ANY CONVECTION DIES OFF AND SKIES CLEAR OUT SOME.
ATTM...WILL LEAVE FOG OUT BUT WITH INCREASED MOISTURE IN THE LOW
LVLS AND POTENTIAL FOR SHOWERS...FOG COULD FORM AT THE FAVORED
AIRPORTS LIKE LWB/BCB.
MOIST AND UNSTABLE AIR STAYS AROUND THROUGH THE WEEK. HOWEVER
HEIGHTS WILL BE BUILDING THROUGH LATE WEEK AS THE UPPER RIDGE
STRENGTHENS OVER THE MISSISSIPPI VALLEY. ONLY ISOLATED TO
SCATTERED OROGRAPHIC DRIVEN CONVECTION FOR MID AND LATE WEEK.
PATCHY LATE NIGHT FOG ALSO LIKELY DURING THE OVERNIGHTS ESPCLY
VALLEYS AND WHERE AFTERNOON/EVENING RAINFALL OCCURS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WP
NEAR TERM...JH/WP
SHORT TERM...NF
LONG TERM...KM
AVIATION...WP
AREA FORECAST DISCUSSION
NWS SPOKANE WA
446 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...
00Z TAFS: Scattered showers and embedded thunderstorms will
continue across eastern WA/N ID within an unstable upper trough
through 03-06z, before shifting toward the north/northeast
mountains and dissipating. Primarily VFR conditions are expected
but local MVFR cigs/vis are possible in heavier showers and winds
could be gusty and erratic. Overnight into Thursday morning there
is a threat of IFR/MVFR stratus developing across the KGEG-KCOE
and KPUW with a moist southwest flow. Confidence in its occurrence
is low. By mid to late morning Thursday the stratus threat wanes,
with another threat of showers developing across the northeast,
possibly near KGEG-KCOE and KPUW. Some gusty wind are also
expected near the Cascades/Basin, including near KEAT in the
afternoon. /J. Cote`
&&
.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
444 AM PDT Tue May 28 2013
.SYNOPSIS...
Today and tomorrow will be showery and cool as a pair of upper
level disturbances move through the Pacific Northwest. The low
pressure pattern will begin to break down on Thursday, and we will
likely begin to see some clearing over central Washington. By
Friday and into the weekend, weak high pressure is expected to
bring a good deal of sunshine and temperatures at or above
average.
&&
.DISCUSSION...
Today through Wednesday night...Longwave trof remains in place
overhead of Eastern Washington and Northern Idaho through this
time interval. The cool pool contained in the trof keeps a
somewhat unstable air mass in place. The model vorticity fields
remain cluttered and hint at numerous small scale disturbances in
vicinity through this period so pops never really zero out but
have maximums associated with most significant shortwave features
of note. This includes a very small synoptic scale negatively
tilted trof passing through Today. The HRRR does a very good job
of resolving a thin line of convective showers and possibly a
thunderstorm or two associated with this trof passage and
additionally hints at some orographically forced showers produced
this afternoon and evening. Since instability is greatest near
the British Columbia border have limited the inclusion of slight
chance of thunderstorm mention for today to the northern mountains
and don`t extend them too far south. Tuesday night has decrease
in convective showers but no end as models continue to hint at
presence of mesoscale shortwaves capable of generating them...
with most model runs focusing activity generally near northern
mountain locations highest pops are there as well. Wednesday yet
another negatively tilted very small synoptic scale disturbance
moves through tracking west to east near the Oregon/Washington
border that is depicted to take a turn and track northeast
Wednesday evening thus pops depict this same scenario. This
disturbance passing Tuesday night into Wednesday has the best
orientation to its moisture tap via an almost south to north
trajectory, therefore it should not have any problems getting
through and a cascades rain shadow will not be produced. Forecast
temperatures remain on the cool side of what would be considered
normal for this time of year given this general trof pattern.
/Pelatti
Thursday: There is still a good deal of uncertainty with the
forecast for Thursday. An elongated upper trough extending from
south of the Aleutians into the Central Plains will bisect the
state of Washington. This "mucky" upper trough will likely contain
some mesoscale feature within it, but it is very tough to forecast
where these little vorticity centers will be at this time. The 00z
GFS is the wettest of the models for Thursday for the Idaho
Panhandle and northeast Washington when compared to the NAM,
ECMWF, SREF and Canadian. So, it is hard to get more excited than
carrying a 20-50 percent chance of showers for the eastern third
of Washington into the Idaho Panhandle, with the highest chances
near the ID/MT border. Lingering showers and clouds will have a
big influence on high temperatures, so there is a high bust
potential given the uncertainty in the precipitation forecast.
Friday through Sunday: There is good model agreement that the
ridiculously elongated upper trough will be broken into pieces by
Friday. A shortwave upper ridge is forecast to develop over the
Pacific Northwest Friday and Saturday bringing an end to the
threat of organized shower activity. Temperatures should moderate
to average during this time frame as well. The shortwave ridge is
expected to be replaced by an upper low descending into southern
British Columbia on Sunday. This low will not be particularly cold
aloft and the high amplitude ridge upstream will cut off any deep
moisture tap. The ECMWF and Canadian models are colder and more
unstable aloft near the Canadian border than the GFS. Slight
chances for showers have been mentioned mainly for the mountain
zones near the B.C. border. /GKoch
Sunday night through Tuesday: A Northwest flow pattern will
prevail through this period as high pressure ridging from the
South Pacific will press North into the region. This ridging will
keep will keep a passing system in southern BC. Any precip
associated with this Low will be mainly in the Northern Mountains
of the Idaho Panhandle but is hard to be certain as the model
agreement is low. Temperatures are expected to be near seasonal
norms during this period. /JDC
&&
.AVIATION...
12Z TAFS: Occluded frontal zone has exited away to the northeast
and into Canada and Northwest Montana while unstable air with
disturbances rotating through it bring more showers approaching
fromt the south and west through the day. MVFR Ceilings may occur
at times but VFR should prevail. After 02Z Wednesday majority of
the convection should be decreased but not totally gone..and
later near 10Z some low cloud formation most locations but also
some shallow ground fog as well. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 64 45 62 46 62 46 / 50 30 40 30 30 20
Coeur d`Alene 63 43 63 45 60 44 / 50 40 40 30 40 30
Pullman 62 43 60 43 60 43 / 30 30 40 40 20 10
Lewiston 68 48 67 48 67 48 / 30 20 60 50 20 10
Colville 68 44 68 46 65 45 / 60 60 50 40 50 20
Sandpoint 62 42 63 45 57 43 / 60 60 50 40 50 30
Kellogg 59 44 58 45 55 43 / 60 60 60 50 60 40
Moses Lake 72 47 69 49 72 47 / 20 10 40 30 10 10
Wenatchee 68 49 66 50 69 49 / 20 10 50 30 10 10
Omak 70 45 69 46 69 45 / 50 30 30 20 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
244 AM PDT Tue May 28 2013
.SYNOPSIS...
Today and tomorrow will be showery and cool as a pair of upper
level disturbances move through the Pacific Northwest. The low
pressure pattern will begin to break down on Thursday, and we will
likely begin to see some clearing over central Washington. By
Friday and into the weekend, weak high pressure is expected to
bring a good deal of sunshine and temperatures at or above
average.
&&
.DISCUSSION...
Today through Wednesday night...Longwave trof remains in place
overhead of Eastern Washington and Northern Idaho through this
time interval. The cool pool contained in the trof keeps a
somewhat unstable air mass in place. The model vorticity fields
remain cluttered and hint at numerous small scale disturbances in
vicinity through this period so pops never really zero out but
have maximums associated with most significant shortwave features
of note. This includes a very small synoptic scale negatively
tilted trof passing through Today. The HRRR does a very good job
of resolving a thin line of convective showers and possibly a
thunderstorm or two associated with this trof passage and
additionally hints at some orographically forced showers produced
this afternoon and evening. Since instability is greatest near
the British Columbia border have limited the inclusion of slight
chance of thunderstorm mention for today to the northern mountains
and don`t extend them too far south. Tuesday night has decrease
in convective showers but no end as models continue to hint at
presence of mesoscale shortwaves capable of generating them...
with most model runs focusing activity generally near northern
mountain locations highest pops are there as well. Wednesday yet
another negatively tilted very small synoptic scale disturbance
moves through tracking west to east near the Oregon/Washington
border that is depicted to take a turn and track northeast
Wednesday evening thus pops depict this same scenario. This
disturbance passing Tuesday night into Wednesday has the best
orientation to its moisture tap via an almost south to north
trajectory, therefore it should not have any problems getting
through and a cascades rain shadow will not be produced. Forecast
temperatures remain on the cool side of what would be considered
normal for this time of year given this general trof pattern.
/Pelatti
Thursday: There is still a good deal of uncertainty with the
forecast for Thursday. An elongated upper trough extending from
south of the Aleutians into the Central Plains will bisect the
state of Washington. This "mucky" upper trough will likely contain
some mesoscale feature within it, but it is very tough to forecast
where these little vorticity centers will be at this time. The 00z
GFS is the wettest of the models for Thursday for the Idaho
Panhandle and northeast Washington when compared to the NAM,
ECMWF, SREF and Canadian. So, it is hard to get more excited than
carrying a 20-50 percent chance of showers for the eastern third
of Washington into the Idaho Panhandle, with the highest chances
near the ID/MT border. Lingering showers and clouds will have a
big influence on high temperatures, so there is a high bust
potential given the uncertainty in the precipitation forecast.
Friday through Sunday: There is good model agreement that the
ridiculously elongated upper trough will be broken into pieces by
Friday. A shortwave upper ridge is forecast to develop over the
Pacific Northwest Friday and Saturday bringing an end to the
threat of organized shower activity. Temperatures should moderate
to average during this time frame as well. The shortwave ridge is
expected to be replaced by an upper low descending into southern
British Columbia on Sunday. This low will not be particularly cold
aloft and the high amplitude ridge upstream will cut off any deep
moisture tap. The ECMWF and Canadian models are colder and more
unstable aloft near the Canadian border than the GFS. Slight
chances for showers have been mentioned mainly for the mountain
zones near the B.C. border. /GKoch
Sunday night through Tuesday: A Northwest flow pattern will
prevail through this period as high pressure ridging from the
South Pacific will press North into the region. This ridging will
keep will keep a passing system in southern BC. Any precip
associated with this Low will be mainly in the Northern Mountains
of the Idaho Panhandle but is hard to be certain as the model
agreement is low. Temperatures are expected to be near seasonal
norms during this period. /JDC
&&
.AVIATION...
06Z TAFS: The mid level occluded front is currently stretching from
KPUW to KSEA over the region. Out ahead of this front is a band of
light stratiform rain. Once this band clears the taf sites, we are
expecting a layer of low stratus to develop across much of the
region, especially north of a line from KMWH to KPUW. This stratus
will result in MVFR cigs and vis with localized IFR cigs possible.
Another batch of showers will move northeast out of northeast Oregon
later tonight into early tomorrow morning. These showers will become
more widespread through the afternoon hours on Tuesday with the
stratus lifting into a stratocumulus deck with VFR conditions
returning by this time. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 64 45 62 46 62 46 / 50 30 40 30 30 20
Coeur d`Alene 63 43 63 45 60 44 / 50 40 40 30 40 30
Pullman 62 43 60 43 60 43 / 30 30 40 40 20 10
Lewiston 68 48 67 48 67 48 / 30 20 60 50 20 10
Colville 68 44 68 46 65 45 / 60 60 50 40 50 20
Sandpoint 62 42 63 45 57 43 / 60 60 50 40 50 30
Kellogg 59 44 58 45 55 43 / 60 60 60 50 60 40
Moses Lake 72 47 69 49 72 47 / 20 10 40 30 10 10
Wenatchee 68 49 66 50 69 49 / 20 10 50 30 10 10
Omak 70 45 69 46 69 45 / 50 30 30 20 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
714 PM CDT WED MAY 29 2013
.UPDATE...
ISSUED AT 714 PM CDT WED MAY 29 2013
HAVE EXPANDED THE FLASH FLOOD WATCH EVEN FARTHER EAST TO NOW
INCLUDE VERNON...CRAWFORD...RICHLAND AND GRANT COUNTIES IN
WISCONSIN. CLUSTER OF THUNDERSTORMS WITH HEAVY RAIN HAS ENTERED
THESE COUNTIES. MEANWHILE...THE ENTIRE MCS OVER THE FORECAST AREA
EXTENDING DOWN TO MARSHALLTOWN AND CEDAR RAPIDS IOWA SHOULD LIFT
NORTH THROUGH THE NIGHT...IN RESPONSE TO STRENGTHENING LOW LEVEL
JET / MOISTURE TRANSPORT. THIS MEANS THE EXPANDED FLASH FLOOD
WATCH AREA COULD SEE PERIODS OF MODERATE TO HEAVY RAINFALL FOR AT
LEAST THE NEXT FEW HOURS.
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 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 714 PM CDT WED MAY 29 2013
THUNDERSTORM COMPLEX OVER THE TAF SITES WILL SLOWLY LIFT NORTHEAST
THROUGH THE EVENING. THE POTENTIAL FOR STRONG WIND GUSTS HAS
ENDED...BUT MVFR RESTRICTIONS TO VISIBILITY WILL LIKELY PERSIST
GIVEN POCKETS OF MODERATE TO HEAVY RAINFALL. THUNDERSTORMS
THEMSELVES ARE MORE SCATTERED ABOUT...BUT ENOUGH COVERAGE TO
WARRANT EITHER VCTS/TSRA THROUGH 03Z. ANTICIPATING MUCH OF THE
RAIN TO END BY 06Z. AFTER THIS...THE FORECAST BECOMES MORE MUDDLED
IN TERMS OF WHEN SHOWERS AND THUNDERSTORMS WILL AFFECT THE TAF
SITES AGAIN. SOME MODELS SUGGEST AT LEAST A BREAK IN THE
PRECIPITATION UNTIL 14Z OR SO...OTHERS NOT AS LONG. CERTAINLY
HEADING INTO THE DAY THURSDAY THERE LOOKS TO BE PLENTY OF FORCING
FOR SHOWERS WITH EMBEDDED THUNDERSTORMS. FOR NOW HAVE FOLLOWED THE
PREVIOUS FORECAST WITH VCSH BEGINNING AROUND 12Z AT BOTH TAF
SITES. MORE FINE TUNING WILL COME IN FUTURE TAF FORECASTS.
IT DOES APPEAR WINDS ARE GOING TO INCREASE ON THURSDAY AHEAD OF A
COLD FRONT MARCHING INTO WESTERN PORTIONS OF MINNESOTA AND IOWA.
SOUTH WINDS THAT WILL HOLD STEADY BETWEEN 10-15KT TONIGHT LOOK TO
INCREASE TO 15-20 KT LATE TOMORROW MORNING WITH GUSTS OF 20-30 KT
IN THE AFTERNOON. IF MORE SUN CAN OCCUR TOMORROW...POTENTIAL FOR
EVEN STRONGER GUSTS EXISTS...ESPECIALLY AT KRST.
&&
.HYDROLOGY...TONIGHT THROUGH FRIDAY
ISSUED AT 714 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 AND SOUTHWEST
WISCONSIN THROUGH THU. THIS MAY NEED TO BE EXPANDED NORTHWARD AS
DETAILS OF TIMING/LOCATION OF THE CONTINUED HEAVY RAIN THREAT
BECOME CLEARER.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLASH FLOOD WATCH THROUGH THURSDAY EVENING FOR WIZ053>055-061.
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...AJ
HYDROLOGY....DAS/AJ
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
130 PM CDT TUE MAY 28 2013
.UPDATE...
SO THE WARM FRONT CREPT INTO SOUTHERN WISCONSIN AND HAS ALREADY
REACHED MADISON AND MILWAUKEE EARLY THIS AFTERNOON. THIS IS A LITTLE
QUICKER THAN WHAT I WAS THINKING EARLIER THIS MORNING. DEWPOINTS ARE
RISING INTO THE MID 60S WITH TEMPS AROUND 70. AN AREA OF SHOWERS
DEVELOPED NEAR THE QUAD CITIES AND IS MOVING NORTHEAST INTO
JANESVILLE AND KENOSHA AREAS NOW. THESE ARE ASSOCIATED WITH SURFACE
THETA-E ADVECTION. SURFACE BASED CAPE IS ON THE RISE...UP TO AROUND
500 J/KG WITH MINIMAL CIN IN SOUTHEAST WI. LOW LEVEL LAPSE RATES ARE
FAIRLY WEAK. THUS...ISOLATED THUNDER IS EXPECTED WITH THESE SHOWERS.
HRRR MODEL CONTINUES TO KEEP STRONGER CONVECTION SOUTH OF THE WI
BORDER TONIGHT...ALTHOUGH THERE WILL STILL BE A CHANCE FOR SHOWERS
AND ISOLATED THUNDER TONIGHT GIVEN THAT THE WARM FRONT WILL LIKELY
HANG UP OVER THE MKX FORECAST AREA.
&&
.AVIATION/18Z TAFS/...
THE WARM FRONT CREPT NORTHWARD QUICKER THAN EXPECTED AND HAS ALREADY
CLEARED KMSN AND KMKE...IDENTIFIED BY SOUTHWEST WINDS AND SCOURING
OF THE LIFR CIGS. THERE IS AN AREA OF SHOWERS WITH ISOLATED THUNDER
ACROSS FAR SOUTHERN WISCONSIN NOW THAT WILL BRIEFLY IMPACT AT LEAST
KMKE THROUGH THE NEXT HOUR. THE WARM FRONT IS EXPECTED TO HANG UP
NEAR SHEBOYGAN AND THE DELLS THROUGH TONIGHT AND CONTINUE THE TREK
NORTHWARD ON WEDNESDAY.
UNCERTAIN ABOUT CEILINGS TONIGHT SINCE THE WARM FRONT WILL BE VERY
CLOSE TO THE KMSN/KUES/KMKE TAF SITES. AREAS OF DENSE FOG AND LOW
CEILINGS WILL BE POSSIBLE MAINLY NORTH OF KMSN AND KMKE TONIGHT
ALONG AND NORTH OF THE WARM FRONT.
THE CHANCE FOR LIGHT RAIN SHOWERS/DRIZZLE WILL CONTINUE OVER ALL OF
SOUTHERN WI THROUGH TONIGHT. CHANCE FOR THUNDER ALONG AND SOUTH OF
THE WARM FRONT.
EXPECT IMPROVEMENT TO MVFR AND EVENTUALLY VFR AS REGION GETS INTO
WARM SECTOR AS WARM FRONT LIFTS INTO CENTRAL WISCONSIN. THIS MAY BE
DELAYED UNTIL EARLY WEDNESDAY MORNING.
&&
.PREV DISCUSSION... /ISSUED 1000 AM CDT TUE MAY 28 2013/
UPDATE...
LATEST HRRR AND 12Z NAM ARE NOW KEEPING THE SURFACE WARM FRONT
FURTHER SOUTH THAN PREVIOUS RUNS. GIVEN THE MORNING ROUND OF
SHOWERS AND STORMS...EFFECTIVE WARM FRONT WILL BE DELAYED IN MOVING
NORTHWARD TODAY. MODELS STILL SHOW IT PUSHING INTO FAR SOUTHERN
WISCONSIN BY LATE AFTERNOON...BUT THEN HAVING IT STALL THIS EVENING
AND BISECT THE MKX FORECAST AREA.
CHANCE OF LIGHT SHOWERS/SPRINKLES/DRIZZLE WILL CONTINUE THROUGH
TODAY AND ALSO TONIGHT WITH THE VICINITY OF THE WARM FRONT...BUT ANY
STORMS DEVELOPING IN THE REGION ARE EXPECTED TO STAY SOUTH OF THE
WI/IL BORDER THROUGH LATE TONIGHT. THE LOW LEVEL JET IS JUST BARELY
OVER SOUTHERN WI TODAY...BUT GENERALLY POINTING TOWARD LOWER
MICHIGAN. LEFT THE SLIGHT CHANCE FOR THUNDER IN THE FORECAST FOR NOW
GIVEN SOME ELEVATED CAPE.
HEADLINE POTENTIAL FOR TONIGHT WILL BE DENSE FOG. WITH LIGHT
EASTERLY FLOW AT THE SURFACE ON THE NORTH SIDE OF THE WARM
FRONT...AREAS OF FOG ARE EXPECTED AND COULD BECOME DENSE. BEST
CHANCE FOR DENSE FOG WOULD BE THE NORTH HALF OF THE MKX FORECAST
AREA.
AVIATION/18Z TAFS/...
THE WARM FRONT AND HIGHER CEILINGS ARE JUST SOUTH OF THE WI/IL
BORDER...BUT NOT EXPECTING THAT FRONT TO MOVE NORTHWARD QUICKLY
TODAY OR TONIGHT. KENW AND KJVL COULD SCOUR OUT THE LIFR CIGS BY
MIDDAY...BUT KMSN/KUES/KMKE WILL LIKELY REMAIN LIFR/IFR THROUGH MOST
OF TONIGHT. PATCHY FOG EXPECTED ACROSS MUCH OF THE SOUTHERN WI
TODAY...THEN AREAS OF DENSE FOG POSSIBLE MAINLY NORTH OF KMSN AND KMKE
TONIGHT WITH PATCHY FOG ALONG AND SOUTH OF THERE.
THE CHANCE FOR LIGHT RAIN SHOWERS/DRIZZLE WILL CONTINUE OVER ALL OF
SOUTHERN WI THROUGH TONIGHT. VERY SMALL CHANCE FOR THUNDER.
EXPECT IMPROVEMENT TO MVFR AND EVENTUALLY VFR AS REGION GETS INTO
WARM SECTOR AS WARM FRONT LIFTS INTO CENTRAL WISCONSIN. THIS MAY BE
DELAYED UNTIL EARLY WEDNESDAY MORNING.
MARINE...
ISSUED MARINE DENSE FOG ADVISORY FOR ALL NEARSHORE ZONES DUE A WARM
FRONT MOVING NORTHWARD THROUGH LAKE MICHIGAN. WARM MOIST AIR FLOWING
OVER THE COOL WATER AND LIGHT EASTERLY WINDS JUST AHEAD OF THE WARM
FRONT ARE LEADING TO AREAS OF DENSE FOG OVER THE LAKE. WEB CAMS
SHOWED IMPROVEMENT TO VISIBILITIES LATE THIS MORNING IN THE
NEARSHORE WATERS WITH RAIN SHOWERS...BUT THEY COULD GO DOWN AGAIN
THIS AFTERNOON. THERE IS A GOOD CHANCE FOR AREAS OF DENSE FOG TO
PERSIST THROUGH TONIGHT...ESPECIALLY NORTH OF MILWAUKEE. MAY NEED TO
EXTEND THE ADVISORY THROUGH TONIGHT.
PREV DISCUSSION... /ISSUED 458 AM CDT TUE MAY 28 2013/
TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM
WIDESPREAD FOG OVER THE AREA WITH COOL EAST FLOW...SOME PATCHY DENSE
FOG BUT MOST VISIBILITIES HOLDING AT 1/2 TO 1 MILE OVER THE FAR WEST
AND 1 TO 3 MILES IN THE EAST. WILL MONITOR FOR POSSIBLE ADVISORY IF
1/4 MILE VSBYS BECOME MORE WIDESPREAD.
SCATTERED TO BROKEN BAND OF SHOWERS WITH A FEW THUNDERSTORMS OVER
FAR SRN SECTIONS OF FORECAST AREA ON NOSE OF INCREASING 850-700 MB
WINDS CURRENTLY FOCUSED ON SRN WI BUT EXPECTED TO HEAL OVER TO THE
EAST...REFLECTED IN DIMINISHING TREND TO WESTERN END OF LINE.
HI-RES/RAPID UPDATE MODELS ALSO TAKE THIS PRECIPITATION OFF TO THE
EAST.
NORTHERN EDGE OF MCS...RIDING ALONG JUST TO THE NORTH OF SURFACE
WARM FRONT AND BEING DRIVEN BY 500 MB SHORT WAVE...WILL CROSS THE
FORECAST AREA BETWEEN 12Z AND 18Z. SPC HAS PUSHED SLIGHT RISK
FARTHER SOUTH ON 28/06Z DAY 1 VERSUS 27/17Z DAY 2 WITH ONLY THE
SOUTHERN-MOST COUNTIES STILL LEFT IN SLIGHT RISK...WITH THAT RISK
TIED TO NORTHERN END OF THE CONVECTIVE COMPLEX. STILL EXPECT DECENT
RAINS WITH PWS RISING TO 1.5 TO 1.7. COOL OUTFLOW IN THE WAKE OF THE
COMPLEX WILL LIKELY HOLD THE EFFECTIVE WARM FRONT TO THE SOUTH UNTIL
MID-LATE AFTERNOON. LOW-LEVEL FRONTOGENESIS WITH APPROACHING WARM
FRONT...BUT WILL HAVE CHANCE POPS IN THE FORECAST FOR THIS AFTERNOON
DUE TO UNCERTAINTY ABOUT STABILIZING AFFECT OF FIRST COMPLEX.
BLEND OF MODEL SOLUTIONS BRINGS WARM FRONT INTO THE SRN-MOST
COUNTIES AROUND 3 PM...THE I-94 CORRIDOR BETWEEN 4 AND 5 PM AND
SLOWS/STALLS NEAR THE NRN COUNTIES AROUND 7 PM BRINGING LATE DAY
HIGHS IN THE 60S TO AROUND 70 AWAY FROM THE LAKE. LOWS DO NOT FALL
OFF MUCH TONIGHT...WITH LOW TO MID 60S...WITH SLIGHTLY COOLER
READINGS NORTH.
WEDNESDAY THROUGH FRIDAY...FORECAST CONFIDENCE...MEDIUM
SHOWER AND THUNDERSTORM CHANCES AND WARM TEMPERATURES ARE EXPECTED
THROUGH THE SECOND HALF OF THE WORK WEEK. MODELS CURRENTLY DEPICT A
WARM FRONT ACROSS THE NORTHERN FORECAST AREA WEDNESDAY
MORNING...LIFTING NORTH THROUGH THE DAY. SHOULD SEE SOME CONVECTION
DURING THE DAY AS THIS FRONT HEADS NORTHWARD. LOOKS PRETTY QUIET
THEN WEDNESDAY NIGHT AS A WARMER AND SOMEWHAT DRIER AIRMASS
PUSHES INTO THE FORECAST AREA...WITH THE LOW LEVEL JET AND
ASSOCIATED CONVECTION REMAINING MAINLY TO THE WEST. DID KEEP SOME
POPS DUE TO GENERAL UNCERTAINTY...THE HIGHEST IN THE WEST TOWARD
THE DEEPER MOISTURE AND STRONGER LOW LEVEL FLOW.
LOW PRESSURE OVER THE DAKOTAS WILL REMAIN NEARLY STATIONARY
THURSDAY...WHILE A SHORTWAVE APPROACHES DURING THE DAY AND THE LOW
LEVEL JET SLIDES EAST INTO THE FORECAST AREA. THE SHORTWAVE WILL
THEN MOVE THROUGH DURING THE EVENING AND INTO OVERNIGHT. THIS
SETUP SHOULD RESULT IN THE BEST CHANCE OF THUNDERSTORMS THROUGH
THE SECOND HALF OF THE WEEK...THUS KEPT LIKELY POPS GOING.
INSTABILITY IS NOT PARTICULARLY IMPRESSIVE THURSDAY...WITH SFC
BASED CAPE GENERALLY LESS THAN 1000 J/KG VIA NAM AND GFS
SOUNDINGS. LOW LEVEL FLOW IS PRETTY GOOD THOUGH...AND 0-6 KM BULK
SHEAR IS AROUND 30-40 KT. STORMS COULD THUS BE STRONG TO
SEVERE...ESPECIALLY IF THERE IS A BIT MORE SUN THAN CURRENTLY
EXPECTED. NEW SPC DAY 3 SEVERE WEATHER OUTLOOK HAS A SLIGHT CHANCE
FOR SEVERE STORMS ACROSS THE FORECAST AREA.
SOUTHERN WISCONSIN WILL REMAIN IN THE WARM SECTOR FRIDAY AS LOW
PRESSURE OVER NORTH DAKOTA AND MINNESOTA CONTINUES TO REMAIN NEARLY
STATIONARY. SHOWERS AND STORMS ARE THUS LIKELY ONCE AGAIN. THOUGH
BETTER LOW LEVEL FLOW WILL BE TO THE SOUTH AND EAST...STRONG TO
SEVERE STORMS ARE NOT OUT OF THE QUESTION WITH SIMILAR CAPE
VALUES AS THURSDAY...AND WIND SHEAR ACTUALLY A BIT HIGHER.
TEMPERATURES WEDNESDAY THROUGH FRIDAY AREA GENERALLY EXPECTED TO BE
A FEW DEGREES ABOVE NORMAL. A BIT TRICKY THOUGH...DEPENDING ON HOW
QUICK THE WARM FRONT GETS NORTH WEDNESDAY...AND THEN DEPENDING ON
TIMING OF SHOWERS AND STORMS AND RESULTANT IMPACT ON TEMPS.
PARTICULARLY DIFFICULT NEAR LAKE MICHIGAN...AS MODELS INDICATE WINDS
WILL BE SOUTHERLY FOR A GOOD PORTION OF THE TIME. WILL NOT TAKE MUCH
FOR THE COOLER LAKE AIRMASS TO INTRUDE INLAND...THOUGH MORE OF A
SOUTHWEST COMPONENT TO THE WIND COULD PUSH THE WARMEST TEMPS ALL THE
WAY TO THE LAKE. GENERALLY KEPT TEMPS A BIT COOLER NEAR THE LAKE DUE
TO THE OVERALL UNCERTAINTY IN WIND DIRECTION AND STRENGTH.
SATURDAY THROUGH MONDAY...FORECAST CONFIDENCE...MEDIUM
WEAKENING LOW PRESSURE WILL FINALLY DRAG A COLD FRONT THROUGH
SOUTHERN WISCONSIN SATURDAY. COULD SEE SOME SHOWERS AND STORMS AHEAD
OF THE FRONT...THE BEST CHANCE TOWARD THE SOUTHEAST. CURRENTLY LOOKS
LIKE NEAR NORMAL TEMPS FOR THE FIRST DAY OF JUNE.
MAIN UPPER LEVEL WAVE WILL MOVE THROUGH SUNDAY...POSSIBLY BRINGING A
FEW SHOWERS. COOLER AIR IS EXPECTED TO ARRIVE WITH THE
SHORTWAVE. LOWERED HIGHS A BIT GIVEN COOLER TREND IN THE ECMWF
AND GFS AND MAY NEED TO GO A FEW DEGREES LOWER IF THIS TREND
CONTINUES.
SHOULD BE PLEASANT MONDAY UNDER HIGH PRESSURE...WITH SOME SUNSHINE
RETURNING AND TEMPERATURES REMAINING A FEW DEGREES BELOW NORMAL.
AVIATION/12Z TAFS/...
WILL KEEP IFR CIGS/VSBYS AT TAF LOCATIONS UNTIL PASSAGE OF MCS
THROUGH THE REGION LATER THIS MORNING...THEN SLOWLY IMPROVE FROM
SOUTH TO NORTH AS WARM FRONT LIFTS THROUGH MID-LATE AFTERNOON. COULD
SEE CONVECTION RE-DEVELOP ALONG FRONT...BUT STABILIZING AFFECT OF
MORNING COMPLEX UNCERTAIN SO WILL KEEP MENTION OUT AFTER PRECIP WITH
COMPLEX ENDS AND SEE HOW ATMOSPHERE RESPONDS. EXPECT IMPROVEMENT TO
MVFR AND EVENTUALLY VFR AS REGION GETS INTO WARM SECTOR AS WARM
FRONT LIFTS INTO CENTRAL WISCONSIN.
MARINE...WINDS AND WAVES WILL REMAIN BELOW SMALL CRAFT ADVISORY LEVELS
UNTIL WEDNESDAY AFTERNOON/WEDNESDAY NIGHT. SOUTHWEST TO SOUTH
WINDS WILL GUST TO 20 TO 25 KNOTS AT TIMES INTO FRIDAY. LOCATIONS
SUCH AS WIND POINT...AND FROM PORT WASHINGTON TO SHEBOYGAN COULD
SEE WAVES AROUND 4 FEET OR BETTER WITH THE PERSISTENT SOUTHERLY
FETCH BY THURSDAY.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...DENSE FOG ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LMZ643>646.
&&
$$
UPDATE...MRC
TODAY/TONIGHT AND AVIATION/MARINE...REM
WEDNESDAY THROUGH MONDAY...DDV
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1000 AM CDT TUE MAY 28 2013
.UPDATE...
LATEST HRRR AND 12Z NAM ARE NOW KEEPING THE SURFACE WARM FRONT
FURTHER SOUTH THAN PREVIOUS RUNS. GIVEN THE MORNING ROUND OF
SHOWERS AND STORMS...EFFECTIVE WARM FRONT WILL BE DELAYED IN MOVING
NORTHWARD TODAY. MODELS STILL SHOW IT PUSHING INTO FAR SOUTHERN
WISCONSIN BY LATE AFTERNOON...BUT THEN HAVING IT STALL THIS EVENING
AND BISECT THE MKX FORECAST AREA.
CHANCE OF LIGHT SHOWERS/SPRINKLES/DRIZZLE WILL CONTINUE THROUGH
TODAY AND ALSO TONIGHT WITH THE VICINITY OF THE WARM FRONT...BUT ANY
STORMS DEVELOPING IN THE REGION ARE EXPECTED TO STAY SOUTH OF THE
WI/IL BORDER THROUGH LATE TONIGHT. THE LOW LEVEL JET IS JUST BARELY
OVER SOUTHERN WI TODAY...BUT GENERALLY POINTING TOWARD LOWER
MICHIGAN. LEFT THE SLIGHT CHANCE FOR THUNDER IN THE FORECAST FOR NOW
GIVEN SOME ELEVATED CAPE.
HEADLINE POTENTIAL FOR TONIGHT WILL BE DENSE FOG. WITH LIGHT
EASTERLY FLOW AT THE SURFACE ON THE NORTH SIDE OF THE WARM
FRONT...AREAS OF FOG ARE EXPECTED AND COULD BECOME DENSE. BEST
CHANCE FOR DENSE FOG WOULD BE THE NORTH HALF OF THE MKX FORECAST
AREA.
&&
.AVIATION/18Z TAFS/...
THE WARM FRONT AND HIGHER CEILINGS ARE JUST SOUTH OF THE WI/IL
BORDER...BUT NOT EXPECTING THAT FRONT TO MOVE NORTHWARD QUICKLY
TODAY OR TONIGHT. KENW AND KJVL COULD SCOUR OUT THE LIFR CIGS BY
MIDDAY...BUT KMSN/KUES/KMKE WILL LIKELY REMAIN LIFR/IFR THROUGH MOST
OF TONIGHT. PATCHY FOG EXPECTED ACROSS MUCH OF THE SOUTHERN WI
TODAY...THEN AREAS OF DENSE FOG POSSIBLE MAINLY NORTH OF KMSN AND KMKE
TONIGHT WITH PATCHY FOG ALONG AND SOUTH OF THERE.
THE CHANCE FOR LIGHT RAIN SHOWERS/DRIZZLE WILL CONTINUE OVER ALL OF
SOUTHERN WI THROUGH TONIGHT. VERY SMALL CHANCE FOR THUNDER.
EXPECT IMPROVEMENT TO MVFR AND EVENTUALLY VFR AS REGION GETS INTO
WARM SECTOR AS WARM FRONT LIFTS INTO CENTRAL WISCONSIN. THIS MAY BE
DELAYED UNTIL EARLY WEDNESDAY MORNING.
&&
.MARINE...
ISSUED MARINE DENSE FOG ADVISORY FOR ALL NEARSHORE ZONES DUE A WARM
FRONT MOVING NORTHWARD THROUGH LAKE MICHIGAN. WARM MOIST AIR FLOWING
OVER THE COOL WATER AND LIGHT EASTERLY WINDS JUST AHEAD OF THE WARM
FRONT ARE LEADING TO AREAS OF DENSE FOG OVER THE LAKE. WEB CAMS
SHOWED IMPROVEMENT TO VISIBILITIES LATE THIS MORNING IN THE
NEARSHORE WATERS WITH RAIN SHOWERS...BUT THEY COULD GO DOWN AGAIN
THIS AFTERNOON. THERE IS A GOOD CHANCE FOR AREAS OF DENSE FOG TO
PERSIST THROUGH TONIGHT...ESPECIALLY NORTH OF MILWAUKEE. MAY NEED TO
EXTEND THE ADVISORY THROUGH TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 458 AM CDT TUE MAY 28 2013/
TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM
WIDESPREAD FOG OVER THE AREA WITH COOL EAST FLOW...SOME PATCHY DENSE
FOG BUT MOST VISIBILITIES HOLDING AT 1/2 TO 1 MILE OVER THE FAR WEST
AND 1 TO 3 MILES IN THE EAST. WILL MONITOR FOR POSSIBLE ADVISORY IF
1/4 MILE VSBYS BECOME MORE WIDESPREAD.
SCATTERED TO BROKEN BAND OF SHOWERS WITH A FEW THUNDERSTORMS OVER
FAR SRN SECTIONS OF FORECAST AREA ON NOSE OF INCREASING 850-700 MB
WINDS CURRENTLY FOCUSED ON SRN WI BUT EXPECTED TO HEAL OVER TO THE
EAST...REFLECTED IN DIMINISHING TREND TO WESTERN END OF LINE.
HI-RES/RAPID UPDATE MODELS ALSO TAKE THIS PRECIPITATION OFF TO THE
EAST.
NORTHERN EDGE OF MCS...RIDING ALONG JUST TO THE NORTH OF SURFACE
WARM FRONT AND BEING DRIVEN BY 500 MB SHORT WAVE...WILL CROSS THE
FORECAST AREA BETWEEN 12Z AND 18Z. SPC HAS PUSHED SLIGHT RISK
FARTHER SOUTH ON 28/06Z DAY 1 VERSUS 27/17Z DAY 2 WITH ONLY THE
SOUTHERN-MOST COUNTIES STILL LEFT IN SLIGHT RISK...WITH THAT RISK
TIED TO NORTHERN END OF THE CONVECTIVE COMPLEX. STILL EXPECT DECENT
RAINS WITH PWS RISING TO 1.5 TO 1.7. COOL OUTFLOW IN THE WAKE OF THE
COMPLEX WILL LIKELY HOLD THE EFFECTIVE WARM FRONT TO THE SOUTH UNTIL
MID-LATE AFTERNOON. LOW-LEVEL FRONTOGENESIS WITH APPROACHING WARM
FRONT...BUT WILL HAVE CHANCE POPS IN THE FORECAST FOR THIS AFTERNOON
DUE TO UNCERTAINTY ABOUT STABILIZING AFFECT OF FIRST COMPLEX.
BLEND OF MODEL SOLUTIONS BRINGS WARM FRONT INTO THE SRN-MOST
COUNTIES AROUND 3 PM...THE I-94 CORRIDOR BETWEEN 4 AND 5 PM AND
SLOWS/STALLS NEAR THE NRN COUNTIES AROUND 7 PM BRINGING LATE DAY
HIGHS IN THE 60S TO AROUND 70 AWAY FROM THE LAKE. LOWS DO NOT FALL
OFF MUCH TONIGHT...WITH LOW TO MID 60S...WITH SLIGHTLY COOLER
READINGS NORTH.
WEDNESDAY THROUGH FRIDAY...FORECAST CONFIDENCE...MEDIUM
SHOWER AND THUNDERSTORM CHANCES AND WARM TEMPERATURES ARE EXPECTED
THROUGH THE SECOND HALF OF THE WORK WEEK. MODELS CURRENTLY DEPICT A
WARM FRONT ACROSS THE NORTHERN FORECAST AREA WEDNESDAY
MORNING...LIFTING NORTH THROUGH THE DAY. SHOULD SEE SOME CONVECTION
DURING THE DAY AS THIS FRONT HEADS NORTHWARD. LOOKS PRETTY QUIET
THEN WEDNESDAY NIGHT AS A WARMER AND SOMEWHAT DRIER AIRMASS
PUSHES INTO THE FORECAST AREA...WITH THE LOW LEVEL JET AND
ASSOCIATED CONVECTION REMAINING MAINLY TO THE WEST. DID KEEP SOME
POPS DUE TO GENERAL UNCERTAINTY...THE HIGHEST IN THE WEST TOWARD
THE DEEPER MOISTURE AND STRONGER LOW LEVEL FLOW.
LOW PRESSURE OVER THE DAKOTAS WILL REMAIN NEARLY STATIONARY
THURSDAY...WHILE A SHORTWAVE APPROACHES DURING THE DAY AND THE LOW
LEVEL JET SLIDES EAST INTO THE FORECAST AREA. THE SHORTWAVE WILL
THEN MOVE THROUGH DURING THE EVENING AND INTO OVERNIGHT. THIS
SETUP SHOULD RESULT IN THE BEST CHANCE OF THUNDERSTORMS THROUGH
THE SECOND HALF OF THE WEEK...THUS KEPT LIKELY POPS GOING.
INSTABILITY IS NOT PARTICULARLY IMPRESSIVE THURSDAY...WITH SFC
BASED CAPE GENERALLY LESS THAN 1000 J/KG VIA NAM AND GFS
SOUNDINGS. LOW LEVEL FLOW IS PRETTY GOOD THOUGH...AND 0-6 KM BULK
SHEAR IS AROUND 30-40 KT. STORMS COULD THUS BE STRONG TO
SEVERE...ESPECIALLY IF THERE IS A BIT MORE SUN THAN CURRENTLY
EXPECTED. NEW SPC DAY 3 SEVERE WEATHER OUTLOOK HAS A SLIGHT CHANCE
FOR SEVERE STORMS ACROSS THE FORECAST AREA.
SOUTHERN WISCONSIN WILL REMAIN IN THE WARM SECTOR FRIDAY AS LOW
PRESSURE OVER NORTH DAKOTA AND MINNESOTA CONTINUES TO REMAIN NEARLY
STATIONARY. SHOWERS AND STORMS ARE THUS LIKELY ONCE AGAIN. THOUGH
BETTER LOW LEVEL FLOW WILL BE TO THE SOUTH AND EAST...STRONG TO
SEVERE STORMS ARE NOT OUT OF THE QUESTION WITH SIMILAR CAPE
VALUES AS THURSDAY...AND WIND SHEAR ACTUALLY A BIT HIGHER.
TEMPERATURES WEDNESDAY THROUGH FRIDAY AREA GENERALLY EXPECTED TO BE
A FEW DEGREES ABOVE NORMAL. A BIT TRICKY THOUGH...DEPENDING ON HOW
QUICK THE WARM FRONT GETS NORTH WEDNESDAY...AND THEN DEPENDING ON
TIMING OF SHOWERS AND STORMS AND RESULTANT IMPACT ON TEMPS.
PARTICULARLY DIFFICULT NEAR LAKE MICHIGAN...AS MODELS INDICATE WINDS
WILL BE SOUTHERLY FOR A GOOD PORTION OF THE TIME. WILL NOT TAKE MUCH
FOR THE COOLER LAKE AIRMASS TO INTRUDE INLAND...THOUGH MORE OF A
SOUTHWEST COMPONENT TO THE WIND COULD PUSH THE WARMEST TEMPS ALL THE
WAY TO THE LAKE. GENERALLY KEPT TEMPS A BIT COOLER NEAR THE LAKE DUE
TO THE OVERALL UNCERTAINTY IN WIND DIRECTION AND STRENGTH.
SATURDAY THROUGH MONDAY...FORECAST CONFIDENCE...MEDIUM
WEAKENING LOW PRESSURE WILL FINALLY DRAG A COLD FRONT THROUGH
SOUTHERN WISCONSIN SATURDAY. COULD SEE SOME SHOWERS AND STORMS AHEAD
OF THE FRONT...THE BEST CHANCE TOWARD THE SOUTHEAST. CURRENTLY LOOKS
LIKE NEAR NORMAL TEMPS FOR THE FIRST DAY OF JUNE.
MAIN UPPER LEVEL WAVE WILL MOVE THROUGH SUNDAY...POSSIBLY BRINGING A
FEW SHOWERS. COOLER AIR IS EXPECTED TO ARRIVE WITH THE
SHORTWAVE. LOWERED HIGHS A BIT GIVEN COOLER TREND IN THE ECMWF
AND GFS AND MAY NEED TO GO A FEW DEGREES LOWER IF THIS TREND
CONTINUES.
SHOULD BE PLEASANT MONDAY UNDER HIGH PRESSURE...WITH SOME SUNSHINE
RETURNING AND TEMPERATURES REMAINING A FEW DEGREES BELOW NORMAL.
AVIATION/12Z TAFS/...
WILL KEEP IFR CIGS/VSBYS AT TAF LOCATIONS UNTIL PASSAGE OF MCS
THROUGH THE REGION LATER THIS MORNING...THEN SLOWLY IMPROVE FROM
SOUTH TO NORTH AS WARM FRONT LIFTS THROUGH MID-LATE AFTERNOON. COULD
SEE CONVECTION RE-DEVELOP ALONG FRONT...BUT STABILIZING AFFECT OF
MORNING COMPLEX UNCERTAIN SO WILL KEEP MENTION OUT AFTER PRECIP WITH
COMPLEX ENDS AND SEE HOW ATMOSPHERE RESPONDS. EXPECT IMPROVEMENT TO
MVFR AND EVENTUALLY VFR AS REGION GETS INTO WARM SECTOR AS WARM
FRONT LIFTS INTO CENTRAL WISCONSIN.
MARINE...WINDS AND WAVES WILL REMAIN BELOW SMALL CRAFT ADVISORY LEVELS
UNTIL WEDNESDAY AFTERNOON/WEDNESDAY NIGHT. SOUTHWEST TO SOUTH
WINDS WILL GUST TO 20 TO 25 KNOTS AT TIMES INTO FRIDAY. LOCATIONS
SUCH AS WIND POINT...AND FROM PORT WASHINGTON TO SHEBOYGAN COULD
SEE WAVES AROUND 4 FEET OR BETTER WITH THE PERSISTENT SOUTHERLY
FETCH BY THURSDAY.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...DENSE FOG ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LMZ643>646.
&&
$$
UPDATE...MRC
TODAY/TONIGHT AND AVIATION/MARINE...REM
WEDNESDAY THROUGH MONDAY...DDV
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1122 PM CDT MON MAY 27 2013
.UPDATE...
ISSUED AT 850 PM CDT MON MAY 27 2013
THE NEAR TERM FOCUS REMAINS ON THE FLOODING POTENTIAL OVERNIGHT
INTO TUESDAY AS THE NEXT ROUND OF RAIN MOVES IN. CURRENTLY...A
LEFT OVER MESOSCALE CONVECTIVE VORTEX HAS STALLED OUT ACROSS
SOUTHEAST MINNESOTA WITH A BAND OF LIGHT TO MODERATE RAIN AND
DRIZZLE OCCURRING NEAR IT. THE MAIN BAND EXTENDS FROM SOUTHEAST
MINNESOTA THROUGH CENTRAL WISCONSIN AND THEN DOWN THROUGH SOUTHERN
LAKE MICHIGAN TO THE MORE POTENT PART OF THE SYSTEM. GIVEN THE
STALLED OUT PATTERN...AM NOT EXPECTING MUCH IN THE WAY OF
DIMINISHMENT OF THIS FEATURE OVERNIGHT...SO WILL KEEP THE
PRECIPITATION CHANCES UP ACROSS THIS REGION.
THE FOCUS THEN GOES TO THE SOUTH WHERE CONVECTION IS EXPECTED TO
DEVELOP ALONG THE NOSE OF THE 850MB MOISTURE TRANSPORT WHICH
CURRENTLY IS ALIGNED ALONG THE IOWA/MISSOURI BORDER. NOT OVERLY
CONFIDENT IN HOW THINGS WILL TRANSPIRE OVERNIGHT...BUT THE PAST
FEW RUNS OF THE RAP AND HRRR HAVE ADVECTED THIS NOSE OF THE
MOISTURE TRANSPORT NORTHWARD INTO CENTRAL IOWA AFTER 6Z WITH THE
MAIN BAND OF CONVECTION TRACKING THAT WAY AS WELL. AN ADDITIONAL
BOOST IN LIFT COMES IN BEFORE 12Z AS A MID LEVEL SHORT WAVE TROUGH
CATCHES UP TO THIS LOW LEVEL MOISTURE TRANSPORT. BOTH THE 28.00Z
RAP & HRRR INCREASE THE 0-3KM MUCAPE UP TO AROUND 1000 J/KG INTO
NORTHEAST IOWA...SO THE CHANCES FOR THUNDER ARE STILL PRETTY
DECENT THERE. GIVEN THIS SCENARIO...THE POTENTIAL FOR FLASH
FLOODING IS STILL THERE...PARTICULARLY FOR NORTHEAST IOWA AND NOT
SO MUCH FOR SOUTHEAST MINNESOTA. ANOTHER FEATURE THAT COULD AFFECT
THIS PATTERN IS WITH THE MCS THAT HAS DEVELOPED SOUTHWEST OF OMAHA
THAT COULD KEEP THE STRONGER MOISTURE ADVECTION FURTHER TO THE
SOUTH ALONG THE SURFACE WARM FRONT.
AT THIS POINT...WILL NOT BE MAKING ANY CHANGES TO THE FLASH FLOOD
WATCH...BUT WILL CONTINUE TO HIGHLIGHT THE SLIGHTLY HIGHER
POTENTIAL FOR FLOODING IN NORTHEAST IOWA.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 320 PM CDT MON MAY 27 2013
REMAINS OF LAST NIGHT RAINS IS STILL MOVING SLOWLY NORTH/NORTHEAST
ACROSS THE AREA. STILL EXPECT SOME OF THIS RAIN TO BE AROUND AT
00Z AND THIS IS CONFIRMED BY THE 27.17Z HRRR. SURFACE ANALYSIS
THIS AFTERNOON SHOWS TWO BOUNDARIES SOUTH OF THE FORECAST AREA. A
WEAK WARM FRONT/WIND SHIFT LINE EXTENDS FROM NORTHWEST IOWA INTO
NORTHERN ILLINOIS. A MUCH STRONGER WARM FRONT LIES ACROSS CENTRAL
MISSOURI. ALL THE 27.12Z MODELS BRING THE SHORT WAVE TROUGH OVER
EASTERN COLORADO NORTHEAST ACROSS THE AREA OVERNIGHT AND TUESDAY
MORNING. THE NAM SHOWS THIS WAVE PRODUCING UP TO 4 PVU/S OF
VORTICITY ADVECTION IN THE 500-300 MB LAYER. THE LIFT FROM THE
WAVE SHOULD BE ENHANCED BY SOME AGEOSTROPHIC MOTIONS AS THE LEFT
EXIT REGION OF THE JET MOVES OVER THE AREA LATE TONIGHT. WITH THE
MAIN WARM FRONT STILL WELL SOUTH OF THE AREA...THE MAIN AREA OF
MOISTURE TRANSPORT SHOULD NOT GET AS FAR NORTH AS PREVIOUSLY
EXPECTED. THE MODELS NOW SHOW THE NOSE OF THIS COMING INTO
SOUTHERN AND CENTRAL IOWA WHICH IS WHERE THE BEST ISENTROPIC UP
GLIDE WILL BE. EXPECT THAT THE NEXT CONVECTIVE COMPLEX WILL
DEVELOP ON THE NOSE OF THIS MOISTURE TRANSPORT THIS EVENING AND
GRADUALLY WORK NORTH/NORTHEAST INTO THE AREA WITH THE BEST CHANCES
FOR RAIN SOUTH OF THE IOWA/MINNESOTA BORDER. STILL GOOD
INGREDIENTS IN PLACE FOR THE STORMS TO BE EFFICIENT RAIN PRODUCERS
WITH WARM CLOUD DEPTHS AROUND 3.5 KM AND PRECIPITABLE WATERS
AROUND 1.5 INCHES. THE COMPLEX THAT FORMS IS EXPECTED TO PRIMARILY
IMPACT THE SOUTHERN SECTIONS OF THE AREA TONIGHT AND THEN MOVE
NORTHEAST THROUGH THE EASTERN SECTIONS TUESDAY MORNING AND
AFTERNOON. BECAUSE OF THIS CONVECTION...THE WARM FRONT IS NOT
EXPECTED TO MOVE MUCH TUESDAY STAYING JUST TO THE SOUTH OF THE
FORECAST AREA. WITH THE CLOUDS...RAIN AND WARMER AIR STAYING SOUTH
OF THE AREA...SIGNIFICANTLY CUT TEMPERATURES AND CONCERNED THAT
THESE MAY STILL BE TOO WARM.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 320 PM CDT MON MAY 27 2013
ONCE THE WAVE MOVES BY TUESDAY...THE UPPER LEVEL RIDGE OVER THE
ATLANTIC WILL BEGIN AMPLIFYING AND AN UPPER LEVEL LOW WILL START
TO FORM OVER THE CENTRAL ROCKIES. THIS WILL CAUSE THE FLOW TO
BECOME MORE SOUTHWEST OVER THE CENTRAL PART OF THE COUNTRY. STILL
EXPECTING SEVERAL SHORT WAVE TROUGHS TO BE EMBEDDED IN THIS
FLOW...BUT CONFIDENCE ON WHERE THESE WILL TRACK IS NOT VERY HIGH
AS THEY COULD MOVE OVER THE AREA OR STAY OFF TO THE WEST. ONCE
THIS PATTERN SETS UP...IT IS EXPECTED TO REMAIN THROUGH THURSDAY
AS THE DOWN STREAM RIDGING BLOCKS OFF ANY EASTWARD MOVEMENT OF THE
UPPER LEVEL LOW. THE SURFACE WARM FRONT SHOULD GET LIFTED NORTH
THROUGH THE AREA IN THIS MORE AMPLIFIED SOUTHWEST FLOW EITHER
TUESDAY NIGHT OR MORE LIKELY WEDNESDAY. HAVE THUS CUT BACK ON
LOW TEMPERATURES FOR TUESDAY NIGHT BEFORE SHOWING THE WARM AIR
ARRIVING FOR WEDNESDAY. AS FOR THE RAIN CHANCES...MAY BE SOMEWHAT
OF BREAK IN THE ACTION TUESDAY NIGHT BEFORE A LINE OF CONVECTION
FORMS ON THE FRONT WEDNESDAY LIFTING NORTH ACROSS THE AREA WITH
ANOTHER POSSIBLE LULL IN THE ACTION WEDNESDAY NIGHT. IF THE MODELS
ARE CORRECT ON TIMING...A HEALTHY SHORT WAVE TROUGH SHOULD BE
COMING ACROSS THE AREA THURSDAY AND WILL TRY TO PUSH A COLD FRONT
TOWARD THE REGION FROM THE WEST. ONCE THE WARM FRONT MOVES
THROUGH...WILL ACTUALLY HAVE THE CHANCE FOR SOME CAPE TO BUILD
OVER THE AREA...BUT HOW MUCH REMAINS UNCERTAIN. BETWEEN 1500 AND
2000 J/KG OF SB CAPE COULD DEVELOP WEDNESDAY AFTERNOON AND
THURSDAY IF THE AREA CAN STAY FREE OF RAIN AND POSSIBLY SEE A
LITTLE BIT OF SUNSHINE. SHEAR OF 25 TO 35 KNOTS LOOKS TO BE
CONFINED TO THE 0-3 KM LAYER SO IF THERE IS AN OPPORTUNITY FOR
SEVERE STORMS TO DEVELOP...LOOKS LIKE THE THREATS WOULD BE HAIL
AND WINDS.
THE EXTENDED RANGE MODELS ALL ARE IN AGREEMENT IN SHOWING THE UPPER
LEVEL LOW OVER THE HIGH PLAINS WILL BEGIN TO OPEN UP INTO AN OPEN
WAVE AND TAKE ON A POSITIVE TILT BY THE END OF THE WEEK. AS THIS
OCCURS...THE DOWN STREAM RIDGE OVER THE EASTERN ATLANTIC IS EXPECTED
TO FLATTEN ENOUGH TO ALLOW THE SYSTEM TO BEGIN PROGRESSING
EAST/NORTHEAST AND FINALLY CLEAR THE UPPER MIDWEST OVER THE WEEKEND.
THE MAIN SURFACE LOW IS EXPECTED TO BE OVER THE DAKOTAS WITH THE
WARM FRONT WELL TO THE NORTH OF THE REGION AND COLD FRONT WELL OFF
TO THE WEST. THIS WILL PUT THE AREA IN THE WARM SECTOR WITH THE
PERIODIC RAIN CHANCES CONTINUING WITH WAVES EXPECTED TO STILL BE
ROTATING AROUND THE UPPER LEVEL SYSTEM. THE RAIN CHANCES WILL
CONTINUE UNTIL THE COLD FRONT MOVES THROUGH EITHER FRIDAY NIGHT OR
SATURDAY WITH SOME POTENTIAL FOR SOME LINGERING WRAP AROUND RAIN
INTO SATURDAY NIGHT OR SUNDAY BEFORE HIGH PRESSURE FINALLY STARTS TO
BUILD IN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1122 PM CDT MON MAY 27 2013
IFR TO LOW END MVFR CONDITIONS WILL CONTINUE THROUGHOUT THE REGION
OVERNIGHT ON INTO TUESDAY NIGHT. WITH A WARM FRONT EXPECTED TO
STAY SOUTH OF THE REGION...LOW LEVEL MOISTURE WILL REMAIN POOLED
ALONG THE NORTHERN PERIPHERY OF IT AND CAUSE THE LOW CEILINGS AND
VISIBILITIES TO CONTINUE. SOME OF THE FORECAST MODELS ARE SHOWING
THE NEXT ROUND OF RAIN SHOWERS MOVING IN LATER THIS MORNING AS A
SYSTEM TRACKS ACROSS IOWA. THIS FEATURE MAY HELP TO START A TREND
OF SLOWLY IMPROVING CONDITIONS WITH SOME POTENTIALLY DRIER AIR
GETTING PULLED IN BEHIND IT. STILL EXPECTING CONDITIONS TO BE IFR
TO MVFR THROUGH MUCH OF THE PERIOD HOWEVER.
&&
.HYDROLOGY...
ISSUED AT 320 PM CDT MON MAY 27 2013
CONFIDENCE OF THE POTENTIAL FOR FLOODING HAS DECREASED TODAY WITH
THE MAIN BAND OF ACTIVITY NOW EXPECTED TO STAY FARTHER SOUTH THAN
ANTICIPATED AT THIS TIME SUNDAY. NOW EXPECTING AMOUNTS TO BE UNDER
AN INCH BOTH TONIGHT AND TUESDAY WITH THE HEAVIEST AMOUNTS ACROSS
NORTHEAST IOWA AND SOUTHWEST MINNESOTA WHERE LOCALLY HIGHER
AMOUNTS COULD PUSH TOTALS UP TO TWO INCHES. NOT MAKING ANY CHANGES
TO THE FLASH FLOOD WATCH AT THIS TIME AS WILL LET TONIGHTS
CONVECTION PLAY OUT AND THEN MAY ADJUSTMENTS IN AREAL COVERAGE AND
TIME AS NEEDED. HAVE ALSO ISSUED A FLOOD WATCH FOR THE TURKEY RIVER
ACROSS CLAYTON COUNTY AS HIGHER RAINFALL TOTALS COULD PUSH IT TO
FLOOD STAGE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...FLASH FLOOD WATCH THROUGH TUESDAY EVENING FOR MNZ079-086>088-
094>096.
IA...FLASH FLOOD WATCH THROUGH TUESDAY EVENING FOR IAZ008>011-018-019-
029-030.
&&
$$
UPDATE...HALBACH
SHORT TERM...04
LONG TERM...04
AVIATION...HALBACH
HYDROLOGY...04
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
320 AM EDT Thu May 30 2013
.NEAR TERM [Through Tonight]...
At upper levels, we see a negatively tilted 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 East Texas. We have seen a very gradual
moistening of the lower levels over the past few days with some
isolated to scattered showers and thunderstorms finally developing
along the inland moving sea breeze on Wednesday. We believe we will
see similar development today. PoPs will be based on a blend of sea
breeze climatology for a type 7 day (strong southeast flow) and
local confidence and CAM guidance. We have continued the recent
trend of going a degree or two above a guidance blend for max temps,
and even more than that for the VLD area. Winds should stay up
enough to once again preclude any fog formation, although if any
place was to see it, it would be the Tallahassee metro area. Min
temps will be 2-4 degrees above normal, generally ranging from the
upper 60s north to the lower 70s for the coastal zones.
&&
.SHORT TERM [Friday Through Saturday]...
We are still only expecting generally subtle changes to both the
Upper level and Lower level patterns over the course of the short
term period, with weak ridging continuing aloft, with the surface
high pressure system lingering to the east of the Carolinas.
However, with the southeasterly flow persisting (albeit gradually
weakening at the lower levels) deep layer moisture is expected to
continue to increase. Precipitable water values in the forecast
soundings may exceed 1.75 inches in many areas by the end of the day
on Saturday, which should allow the Sea Breeze Front to become more
efficient at producing mainly afternoon and evening showers and
thunderstorms over the interior, and the nighttime Land Breeze to
produce more convection over the Coastal Waters. Therefore, went
above all available guidance for PoPs on both days (save the always
extremely high SREF), with inland rain chances ranging from 20 to 40
percent on Friday, and 40 to 50 percent on Saturday. Despite the
increase in PoPs, high and low temps are expected to remain a bit
above climo, with highs ranging from the mid 80s along the coast to
the lower 90s further inland. Low temps will range from the upper
60s, to the lower 70s from the interior to the coast.
&&
.LONG TERM [Saturday Night through Tuesday]...
The large scale longwave pattern commences with ridging over Wrn,
troughing over Cntrl to Appalachians/Wrn Gulf ridging Ewd into Wrn
Atlc. At the surface, high Wrn Atlc with ridge Ewd across Nrn gulf
region. Low over Nrn Great Lakes with cold front SSW across TN
Valley into TX.
During the rest of the period, Cntrl trough will continue pushing
Ewd with axis down Ern Gulf Sun night or Mon with ECMWF quickest in
movement. Cold front pushed SEWD with weakening and retreating ridge
but with again some model disagreement. Some models like GFS
stall it along Nrn gulf coast others like ECMWF bring it across
our area Mon into Mon night with veering winds and an increase in
rain Sun into Mon. As trough/front push offshore, upstream ridge
begins to overspread region Tues. Also by Monday, both the GFS and
ECMWF develop a surface wave near the Yucatan Peninsula with some
indication that this low will develop NEWD into the Gulf of Mex.
but it is far too early to determine the track or intensity of
this possible feature. Seasonable temperatures should occur
throughout the period, with highs generally in the low 90s and
lows in the mid- upper 60s.
&&
.AVIATION
[Through 06 UTC Friday] The NARRE and HRRR guidance once again
support the gridded LAMP and MOS in showing low ceilings developing
overnight across most of the area. We show a few hours of MVFR at
the terminals, not quite as low as guidance, but similar to what
happened yesterday. Visibility restrictions are not anticipated as
surface winds are forecast to remain around 5-9 kt through the
night. One possible exception is the TLH vicinity which received the
bulk of the showers and storms last evening. We indicate some
restriction there, but not below the ceiling category. Isolated to
scattered shower and thunderstorm development is expected once again
this afternoon. However, coverage is not expected to be sufficient
for tempo groups and convection was only mentioned in the vicinity
of area terminals.
&&
.MARINE...
A ridge of high pressure to the east of the Carolinas will continue
to provide favorable conditions for mainly nocturnal wind surges
out of the southeast through Saturday. Winds speeds will continue to
reach the Cautionary range, with a few areas near Small Craft
Advisory levels through tonight and into Friday morning. The
pressure pattern is expected to weaken and break down by later on
Saturday and very clearly by Sunday, with afternoon wind speeds
around 10 knots anticipated by Sunday afternoon.
&&
.FIRE WEATHER...
RH will be insufficiently low to reach red flag criteria for the
foreseeable future. However, dispersion indices will remain
elevated, over 75 across most areas today and again on Friday.
&&
.HYDROLOGY...
Isolated to scattered showers and thunderstorms are expected over
the next several days, and though a few locations could receive
locally heavy rainfall, no significant impacts are anticipated on
our area rivers.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 91 70 91 69 91 / 40 10 30 20 50
Panama City 88 73 87 73 87 / 30 20 30 20 50
Dothan 92 68 91 69 92 / 30 20 30 20 40
Albany 91 68 92 67 92 / 10 10 30 20 40
Valdosta 93 67 93 67 92 / 20 10 20 20 40
Cross City 93 67 92 67 92 / 30 20 30 20 50
Apalachicola 87 72 85 73 85 / 30 20 30 20 40
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...Wool
SHORT TERM...Gould
LONG TERM...Block
AVIATION...Wool
MARINE...Gould
FIRE WEATHER...Wool
HYDROLOGY...Gould
AREA FORECAST DISCUSSION
NWS MIAMI FL
238 AM EDT THU MAY 30 2013
.SHORT TERM (TODAY THROUGH SATURDAY)...
THE GLOBAL MODELS CONTINUE TO STRUGGLE WITH THE OVERALL SURFACE
SYNOPTIC PATTERN IN THIS PERIOD BUT ARE IN AGREEMENT THAT THE MID
LEVEL PRESSURE PATTERN WILL REMAIN QUITE WEEK ACROSS SOUTH
FLORIDA. THE GFS, ECMWF AND NAM ALL SHOW A WEAK 500 MB TROUGH
DEVELOPING EAST OF THE PENINSULA ON FRIDAY AND SATURDAY DRIFTING
IT TO THE NORTHEAST. THIS COULD ALLOW FOR SOME SLIGHT DRYING ALOFT
AS DRIER AIR MOVES SOUTHWARD ON THE WEST SIDE OF THE TROUGH. THIS
IS REFLECTED IN THE LATEST POP GUIDANCE FROM BOTH THE MET AND MAV
WHICH SHOW A TREND WITH LOWER NUMBERS AFTER TODAY. THE NAM AND GFS
HAVE COME MORE IN LINE AT THE SURFACE IN DEVELOPING A WEAK
INVERTED TROUGH OVER THE FLORIDA STRAITS ON FRIDAY AND DRIFTING IT
TO THE NORTH ON SATURDAY WHICH LESSENS THE LOW LEVEL SOUTHEAST
WIND FLOW SIGNIFICANTLY. THE ECMWF DOES NOT SHOW THIS FEATURE
MAINTAINING AN ONSHORE FLOW ALONG THE SOUTHEAST COAST ALTHOUGH IN
A WEAKENED STATE AS IT SHOWS THE RIDGE TO THE NORTH WEAKENING. THE
NAM HAS INITIALIZED THE BEST COMPARING IT TO CURRENT OBSERVATIONS
FROM THE C-MAN STATIONS BUT THE QUESTION WILL THE WEAK TROUGH
DEVELOP AS FORECAST FROM THE NAM AND GFS. EVEN THOUGH THE NAM AND
GFS HAVE BEEN CONSISTENT IN FORECASTING THIS TROUGH, THEY HAVE
BEEN VERY INCONSISTENT IN ITS TIMING. THEREFORE, WILL LEAN TOWARDS
THE NAM EARLY IN THE PERIOD BUT THEN GO MORE WITH THE ECMWF FOR
FRIDAY NIGHT AND SATURDAY.
THE OTHER FACTOR IN THE SHORT TERM IS THE AMOUNT OF RAINFALL THAT
IS POSSIBLE. MOST OF THE RAIN THE PAST FEW DAYS HAS BEEN
CONCENTRATED OVER THE EASTERN HALF OF THE SOUTHERN PENINSULA WITH
VERY SATURATED GROUNDS FROM PERSISTENT RAIN PERIODS SINCE APRIL.
GIVEN THE ONGOING ONSHORE FLOW OF MOIST AND UNSTABLE AIR AND
SCATTERED SHOWERS, THE FLOOD WATCH WILL CONTINUE THROUGH 12Z
FRIDAY. THE LATEST RUN OF THE HRRR WHICH TYPICALLY DOES QUITE WELL
DOES NOT SHOW MUCH ACTIVITY THROUGH EARLY THURSDAY. HOWEVER, WITH
VERY LITTLE CHANGE IN THIS PATTERN AT LEAST THROUGH THURSDAY NIGHT
THE SHOWER ACTIVITY COULD DEVELOP AT ANY TIME AND MOVE ONSHORE
WITHIN THE FLOOD WATCH BOX.
.LONG TERM (SATURDAY NIGHT THROUGH WEDNESDAY)...
BOTH THE GFS AND ECMWF ARE IN GOOD AGREEMENT SHOWING A MID LEVEL
TROUGH DEEPENING ACROSS THE EASTERN U.S. MAINTAINING A RIDGE TO
THE WEST AND A WEAK PRESSURE PATTERN ACROSS SOUTH FLORIDA. AT THE
SURFACE, BOTH MODELS COME MORE IN LINE WITH A LIGHTER SOUTHEAST
FLOW AS THE RIDGE WEAKENS AND SHIFTS TO THE EAST AS A WEAK COLD
FRONT MOVES INTO THE SOUTHEAST STATES. HOWEVER, THE GFS THEN
DEVELOPS A STRONGER SURFACE TROUGH OVER THE GULF STATES LATE IN
THE PERIOD AND VEERS THE WIND ACROSS SOUTH FLORIDA TO THE
SOUTHWEST. BEING THIS LATE IN THE FORECAST, WILL NOT JUMP ON THAT
AND WILL LEAN MORE TOWARDS THE ECMWF SOLUTION THROUGH THE ENTIRE
EXTENDED PERIOD.
&&
.AVIATION...
BERMUDA HIGH CONTINUES TO BRING STRONG EASTERLY FLOW AND RAIN
SHOWERS TO SOUTH FLORIDA THROUGH THE TAF PERIOD. THERE IS A LULL
IN PRECIPITATION THIS MORNING THAT SHOULD COME TO AN END AFTER
SUNRISE. THE RAIN MAY BE HEAVY AT TIMES, REDUCING FLIGHT
CATEGORIES TO MVFR AND IFR FOR SHORT PERIODS OF TIME. HOWEVER,
WITH SUCH GREAT UNCERTAINTY AS TO WHEN AND WHERE THEY WILL OCCUR,
HAVE NOT REFLECTED THE REDUCTIONS IN THE TAFS AT THIS TIME. WINDS
WILL BE GUSTY ONCE AGAIN TODAY. THERE IS SOME INDICATION IN THE
MODELS THAT WINDS AND PRECIPITATION MAY SETTLE DOWN FOR AT LEAST
WHILE LATE THIS EVENING AND POSSIBLY OVERNIGHT TONIGHT. BUT,
CONFIDENCE IS LOW ON THIS AT THIS TIME.
&&
.MARINE...
ROUGH MARINE CONDITIONS WILL CONTINUE THROUGH AT LEAST EARLY
FRIDAY. MODEL GUIDANCE HINTS AT SOME WEAKENING IN THE GRADIENT
FLOW LATE FRIDAY INTO THE WEEKEND WITH CALMER WIND AND SEAS. JUST
HOW MUCH WEAKENING DEPENDS ON THE RAPIDNESS OF THE SLACKENING
GRADIENT WITH TIME. FOR NOW, HAVE KEPT A SOUTHEAST FLOW WITH
SUBSIDING SPEEDS AS HIGH PRESSURE RETREATS TO THE EAST.
&&
.FIRE WEATHER...
NO PROBLEMS OR CONCERNS WITH AMPLE TROPICAL MOISTURE IN PLACE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 84 77 86 76 / 60 30 50 40
FORT LAUDERDALE 83 76 85 77 / 70 40 50 40
MIAMI 83 75 87 76 / 70 40 50 40
NAPLES 89 72 89 74 / 60 30 40 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...FLOOD WATCH THROUGH FRIDAY MORNING FOR COASTAL BROWARD-COASTAL
MIAMI DADE-COASTAL PALM BEACH-FAR SOUTH MIAMI DADE-INLAND
BROWARD-INLAND MIAMI DADE-INLAND PALM BEACH-METRO BROWARD-
METRO MIAMI DADE-METRO PALM BEACH.
RIP CURRENT RISK THROUGH FRIDAY 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...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR COASTAL
WATERS FROM CHOKOLOSKEE TO BONITA BEACH, FL OUT 20 NM-
COASTAL WATERS FROM EAST CAPE SABLE TO CHOKOLOSKEE, FL OUT
20 NM-GULF WATERS FROM CHOKOLOSKEE TO BONITA BEACH, FL
EXTENDING FROM 20 TO 60 NM.
&&
$$
DISCUSSION/MARINE/FIRE...30/KOB
AVIATION/RADAR...13/SI
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
132 AM EDT THU MAY 30 2013
.PREV DISCUSSION... /ISSUED 800 PM EDT WED MAY 29 2013/
UPDATE...
NO CHANGES PLANNED FOR THE FORECAST EXCEPT SOME MINOR TWEAKS TO SKY
COVER.
41
PREVIOUS...
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...
06Z UPDATE...
VFR TO START THE PERIOD...BUT EXPECT LOW MVFR TO POTENTIALLY IFR
CIGS TO MOVE IN OVER THE NEXT FEW HOURS. EXPECT IMPROVEMENT
STARTING BETWEEN 15-17Z...WITH VFR CONDITIONS EXPECTED THROUGH THE
AFTERNOON. EXPECT ANOTHER ROUND OF LOW MVFR TO IFR CONDITIONS
FRIDAY MORNING...AND WITH GUIDANCE MORE PESSIMISTIC FOR TOMORROW
THAN TODAY...HAVE INTRODUCED IFR CIGS FOR ATL AROUND 10Z FRIDAY.
SE WINDS THROUGH THE PERIOD GENERALLY BETWEEN 5-10KT THIS
AFTERNOON...MAY SEE SOME LOW-END GUSTS AS WELL.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM ON TIMING OF CIGS TODAY AND TOMORROW.
MEDIUM ON CIG HEIGHTS.
HIGH ON ALL OTHER ELEMENTS.
TDP
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 87 66 85 66 / 5 5 10 10
ATLANTA 85 66 85 67 / 5 5 20 10
BLAIRSVILLE 83 63 82 63 / 5 5 10 10
CARTERSVILLE 86 66 85 66 / 5 10 20 10
COLUMBUS 88 68 89 71 / 10 10 30 10
GAINESVILLE 83 66 83 65 / 5 5 10 10
MACON 88 66 88 65 / 5 5 10 10
ROME 87 66 85 66 / 5 20 30 10
PEACHTREE CITY 86 66 85 65 / 5 5 20 10
VIDALIA 90 67 90 70 / 5 5 5 10
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
129 AM EDT THU MAY 30 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 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 129 AM EDT THU MAY 30 2013
A DISTURBANCE MOVING IN WL BRING THE THREAT OF SOME SHRA AND
POSSIBLY A TS TO MAINLY IWD AND CMX OVERNIGHT. VFR CONDITIONS WILL
CONTINUE THROUGH THE PERIOD AT IWD...BUT AT CMX WHEN THE SHOWERS
MOVE THROUGH...COULD TEMPORARILY SEE MVFR CIGS/VIS OVERNIGHT. AT
SAW...SIGNS ARE POINTING TO AN UPSLOPE FOG EVENT FROM LOW LEVEL
MOISTURE COMING IN FROM LAKE MICHIGAN. EARLIER THINKING WAS SOME LOW
CLOUDS WOULD FORM...BUT ESC DEW POINT HAS REALLY DROPPED AND THINK
FOG WILL BE THE MAIN THREAT NOW. WILL GO MVFR VIS OVERNIGHT AT SAW
WITH SOUTH UPSLOPE WINDS. MIXING AND HEATING WILL BRING BACK VFR BY
MID MORNING AT SAW. COULD SEE SAME THING HAPPEN AT SAW MID THU
EVENING.
&&
.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...07
MARINE...KEC
AREA FORECAST DISCUSSION
NWS GAYLORD MI
100 AM EDT THU MAY 30 2013
.SYNOPSIS...
ISSUED AT 432 PM EDT WED MAY 29 2013
UNSETTLED WEATHER WILL BE THE RULE THROUGH THE NEAR FUTURE...AS A
WARM FRONT GRADUALLY LIFTS NORTH INTO ONTARIO BY THURSDAY. THIS
FEATURE WILL PROVIDE CHANCES FOR SCATTERED SHOWERS AND THUNDERSTORMS
THROUGH MID DAY ON THURSDAY. WE`LL GET A BREAK FROM THE ACTIVITY FOR
THURSDAY AFTERNOON AND EVENING. BUT MORE CHANCES FOR SHOWERS AND
STORMS WILL ENTER THE PICTURE FRIDAY THROUGH SUNDAY...AS A COLD
FRONT SLOWLY SLIDES ACROSS THE GREAT LAKES.
&&
.UPDATE...
ISSUED AT 1259 AM EDT THU MAY 30 2013
03Z MESOANALYSIS SHOWS BROAD POOL OF THUNDERSTORM-COOLED AIR ACROSS
MUCH OF WESTERN/CENTRAL WISCONSIN/NORTHEAST IOWA WITH THE LEADING
EDGE OUTFLOW BOUNDARY ARCING ACROSS EASTERN WISCONSIN BACK INTO EAST
CENTRAL IOWA. TEMPERATURES WERE IN THE 60S ACROSS A GOOD CHUNK OF
NORTHERN LOWER...WITH DEW POINT TEMPERATURES NOT TOO DISSIMILAR.
SKIES WERE MAINLY CLEAR ACROSS NORTHERN LOWER...WITH LOW CLOUDS
ACROSS UPPER MICHIGAN AND JUST GRAZING THE NORTHEAST LOWER SHORELINE
FROM LAKE HURON. GETTING SOME PATCHY FOG DEVELOPMENT AS WELL.
LARGE AREA OF SHOWERS/THUNDERSTORMS ACROSS WISCONSIN SPREADING INTO
WESTERN UPPER MICHIGAN...LEADING EDGE CONVECTION ALONG OUTFLOW
BOUNDARY HAS BEEN WEAKENING AS IT APPROACHES THE WISCONSIN
SHORELINE. 00Z APX SOUNDING SHOWED A FAIRLY SHALLOW MIXED LAYER
CAPPED BY A SUBSIDENCE INVERSION IN THE 860-850MB LAYER. THERE IS A
LOW LEVEL THETA-E RIDGE THAT RUNS FROM FKS-MBL SOUTHEAST TOWARD
GRR-LAN-PTK WHERE THERE IS SOME POTENTIAL INSTABILITY THOUGH IT MAY
BE TOO DRY/CAPPED TO SUPPORT CONVECTIVE DEVELOPMENT. WILL KEEP AN
EYE ON THIS AREA TO MAKE SURE NO MISCHIEF DEVELOPS. OTHERWISE...
WILL MAKE A FEW ADJUSTMENTS TO POP GRIDS AS WELL AS FOG TO COVER
MARINE LAYER INTRUSION INTO FAR NORTHEAST LOWER.
UPDATE ISSUED AT 1019 PM EDT WED MAY 29 2013
CLEAR CONCERNS FOR THE OVERNIGHT ARE FOG AND PRECIP.
AIR MASS OVER MOST OF NORTHERN MI IS PRIMED FOR FOG. MARINE LAYER
HAS COME CHARGING IN FROM LAKE HURON...WITH THE OSC AWOS/SPOTTERS/
FOG IMAGERY SHOWING FOG IN THAT AREA...ALMOST UP TO APN. PLENTY OF
MARINE AIR STILL IN PLACE FROM THE STRAITS NORTH AS WELL.
MEANWHILE...RADIATIONAL COOLING BARELY UNDERWAY...BUT IS ALREADY
REDUCING VSBYS AT PLN AND BELLAIRE. WE HAD GROUND FOG DEVELOPING
IN A FIELD ADJOINING THE OFFICE RIGHT AT SUNSET. OF COURSE...
FAVORABLE RADIATIONAL COOLING CONDITIONS WILL BE COMING TO AN END
SOON...AS A THICK CIRRUS SHROUD IS ADVANCING ABOVE LAKE MI AND
CENTRAL UPPER MI. THIS SHOULD KEEP WIDESPREAD PEA SOUP FROM
FORMING...BUT HAVE STEADILY EXPANDED FOG MENTION AND SEVERITY IN
THE GRIDDED FORECASTS.
HAVE ALSO REJIGGERED PRECIP CHANCES. RADAR TRENDS IN WI REMAIN
SOMEWHAT OMINOUS AT 1ST GLANCE. BUT THE 00Z SOUNDING FROM GRB IS
RELATIVELY DRY (PWAT 0.9) AND CAPPED...AND THAT AIR MASS ISN/T
GETTING MORE UNSTABLE WITH TIME. 00Z APX SOUNDING WAS LESS
UNSTABLE AND MORE CAPPED. THOUGH A WARMER/MORE MOIST AIR MASS WILL
TRY TO WORK NORTHWARD INTO NORTHERN MI...THE LOW LEVEL JET WILL BE
MUCH STRONGER TO OUR WEST. UPSTREAM MCS APPEARS TO BE EVOLVING IN
RESPONSE...WITH LIGHTNING BECOMING LESS COMMON ALONG IT/S LEADING
(EASTERN) EDGE...AND MORE COMMON ALONG THE RIGHT REAR (SOUTHWEST)
FLANK. THUS...THE EARLIER FORECAST THINKING STILL APPEARS
SOUND....LIFTING THE MCS REMNANTS NE-WARD ACROSS WI AND UPPER MI
OVERNIGHT. LATEST HRRR RUNS REMAIN SUPPORTIVE OF THIS
THINKING...WITH NO PRECIP IN THIS CWA EXCEPT IN FAR WESTERN
CHIP/MACK. HAVE REMOVED CHANCE POPS FROM NE LOWER...ADDED SMALL
CHANCE POPS ALONG THE NW LOWER MI COAST...AND RETAINED CHANCE POPS
IN EASTERN UPPER (HIGHEST IN WESTERN CHIP/MACK).
MIN TEMPS WILL BE QUITE MILD OUTSIDE OF MARINE-INFLUENCED AREAS.
UPDATE ISSUED AT 739 PM EDT WED MAY 29 2013
APPEARS TO BE SAFE TO PULL PRECIP FROM THE SAGINAW BAY REGION THIS
EVENING. CU FIELD IS IN DECLINE...AND EARLIER ECHOES ON RADAR HAVE
EXITED.
HAVE REDUCED CLOUD COVER SUBSTANTIALLY THIS EVENING...PER SAT
TRENDS...ESPECIALLY IN NORTHERN LOWER MI.
HAVE EXPANDED FOG INTO PARTS OF NORTHERN LOWER...ESPECIALLY WHERE
LOW CLOUDS AND/OR MARINE AIR LINGERED LONGEST TODAY. TEMP/DEW
POINT SPREADS ARE ALREADY 10F OR LESS AT APN/PLN...AND WITH WINDS
LIGHTENING AND SKIES (TEMPORARILY) CLEARING...CERTAINLY LOOKS LIKE
SOME FOG COULD FORM QUITE QUICKLY...PERHAPS EVEN BY MIDNIGHT. IT
WILL BE AN INTERESTING RACE...AS A CIRRUS SHROUD FROM UPSTREAM
SHRA/TSRA IS STEADILY ADVANCING ACROSS WI...AND WILL BE
ENCROACHING ON THE AREA LATE EVENING AND ESPECIALLY OVERNIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 432 PM EDT WED MAY 29 2013
ON THE LATEST SURFACE WEATHER MAP...1022 MB HIGH PRESSURE WAS OVER
VIRGINIA WHILE 1003 MB LOW PRESSURE WAS OVER NORTHERN ONTARIO AND
992 MB LOW PRESSURE WAS OVER WESTERN KANSAS...WHILE A SURFACE WARM
FRONT WAS LOCATED JUST SOUTH OF THE FORECAST AREA. SATELLITE
IMAGERY SHOWED LOTS OF CLOUDS ACROSS NORTHERN MICHIGAN BUT APX
RADAR WAS VOID OF RETURNS. THE MAIN SHORT TERM FORECAST CONCERNS
ARE NUMEROUS AND INCLUDE THUNDERSTORM POTENTIAL ACROSS SOUTHEAST
ZONES INTO THE EVENING HOURS THEN THUNDERSTORM CHANCES OVERNIGHT
AND AGAIN THURSDAY ACROSS ALL OF THE COUNTY WARNING AREA.
THIS EVENING...CLOUDS HAVE BEEN A REAL CHALLENGE THIS AFTERNOON AS
USUAL. MARINE STRATUS CONTINUES TO PLAGUE MARINE AREAS...AS WELL AS
SPILLING INTO NORTHWEST LOWER WHILE SOUTHWEST ZONES HAVE SEEN AN
INCREASE IN DIURNALLY DRIVEN CU (AFTER THE LOW CLOUDS MIXED OUT
EARLIER). THE TREND HAS BEEN FOR CLOUDS TO GENERALLY DISSIPATE
ACROSS THE SOUTHWESTERN ZONES AND THIS SHOULD CONTINUE THROUGH THE
EVENING HOURS. COULD SEE A SHOWER OR THUNDERSTORM POP UP ACROSS
SOUTHEAST ZONES OVER THE NEXT FEW HOURS WHERE THERE WAS THE MOST
SUN/HEATING TODAY...IN COMBINATION WITH A BIT OF CONVERGENCE FROM A
LAKE BREEZE OFF OF LAKE HURON. THEREFORE...WILL CONTINUE WITH LOW
CHANCE POPS DOWN THERE. SEVERE POTENTIAL LOOKS LIMITED WITH WINDS
ALOFT ON THE LIGHT SIDE.
OVERNIGHT...CONVECTION ACROSS EASTERN MINNESOTA AND EASTERN IOWA
EXPECTED TO TRACK TOWARD THE THETA-E RIDGE MOVING INTO THE NORTHERN
HALF OF THE FORECAST AREA OVERNIGHT. STILL SOME DOUBT WHETHER THESE
STORMS WILL SURVIVE THIS FAR EAST...SO WILL CONTINUE TO COVER IT
WITH CHANCE WORDING. SEVERE POTENTIAL REMAINS LIMITED WITH 0-6KM
BULK SHEAR OF 30 KNOTS OR LESS. WARM AND MUGGY OVERNIGHT WITH
LOWS RANGING FROM THE MIDDLE 50S NORTH TO THE MIDDLE 60S SOUTH.
THURSDAY...WE ARE EXPECTED TO FINALLY BREAK OUT INTO THE WARM
SECTOR AS THE SURFACE WARM FRONT MOVES THROUGH THE REGION LEADING
TO HIGHS RANGING FROM THE UPPER 70S NORTH TO THE MIDDLE 80S
SOUTHEAST. IN ADDITION...THETA-E RIDGE BUILDS IN FROM THE WEST. LOOKING
AT MODEL SOUNDINGS...NOT MUCH CAPPING IN EVIDENCE SO COULD SEE A
FEW INSTABILITY DRIVEN THUNDERSTORMS DEVELOPING IN THE AFTERNOON
AND EARLY EVENING HOURS...SO HAVE ADDED IN LOW CHANCE POPS.
&&
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 432 PM EDT WED MAY 29 2013
OVERVIEW: 4-WAVE HEMISPHERIC PATTERN IN PLACE TO START THIS FORECAST
CYCLE WITH LONG WAVE TROUGHS ANCHORED OVER THE EASTERN PACIFIC (NEAR
150W) AS WELL AS FAR EASTERN CANADA (NEAR 60W)...WITH LOW AMPLITUDE
RIDGING IN BETWEEN. ON THE SHORTER SCALE...FAST MID LEVEL FLOW IN
PLACE ACROSS THE EASTERN PACIFIC DIGGING INTO AN INVERTED SHORT WAVE
TROUGH IN THE WESTERN CONUS INTO THE PLAINS. ASSOCIATED SFC LOW
CENTERED NEAR THE COLORADO/KANSAS BORDER THIS MORNING WITH A
SOMEWHAT STATIONARY FRONT ARCHING UP INTO THE GREAT LAKES. SFC LOW
AND STATIONARY FRONT CONTINUE TO DRIVE EPISODES OF SHOWERS AND
STORMS FROM THE CENTRAL PLAINS THROUGH THE MIDWEST/LOWER GREAT
LAKES. SHORT WAVE TROUGH WILL CONTINUE TO BE THE MAIN WEATHER PLAYER
AS IT SLOWLY WORKS THROUGH THE PLAINS AND ULTIMATELY THE GREAT LAKES
OVER THE NEXT SEVERAL DAYS. CONVECTIVE TRENDS/TIMING WILL BE THE
TOUGH PART OF THE FORECAST AS THIS OCCURS. TEMPERATURES WILL
INITIALLY BE ON THE WARMER SIDE OF THINGS (RAIN AND CLOUDS
DEPENDENT) BUT TURN RATHER COOL AGAIN FOR THE WEEKEND AS THE TROUGH
AND ASSOCIATED POCKET OF COLD AIR WORK THROUGH. SHAPING UP TO BE
ANOTHER RIP-OFF SUMMER WEEKEND...SORRY.
THURSDAY NIGHT AND FRIDAY...CLOSED AND NEARLY STACKED LOW PRESSURE
SYSTEM EXPECTED TO BE MIGRATING SLOWLY ACROSS THE NRN PLAINS INTO
THE UPPER MIDWEST THROUGH THIS TIMEFRAME WITH THE FRONT STRETCHED
SOMEWHERE THROUGH THE NRN GREAT LAKES. MAIN FOCUS FOR CONVECTION
THURSDAY NIGHT WILL LIKELY BE ACROSS THE MID TO UPPER MISSISSIPPI
RIVER VALLEY WHERE WARM/MOIST SOUTHERLY INFLOW WILL INTERACT WITH
BETTER SYNOPTIC FORCING. BUT THERE WILL BE THE CHANCE THAT SOME OF
THAT ACTIVITY COULD EVENTUALLY SPREAD INTO THE GREAT LAKES THURSDAY
NIGHT/FRIDAY MORNING AS MID LEVEL SHORT WAVE IMPULSE SWINGS UP INTO
THE REGION. THAT SAID...TOUGH TO HAVE HIGH CONFIDENCE IN THE DETAILS
AT THIS JUNCTURE GIVEN ALL THE CONVECTION THAT WILL OCCUR BETWEEN
NOW AND THEN. SO FOR NOW WILL HAVE JUST CHANCY POPS OVERNIGHT
THURSDAY NIGHT OVER THE WESTERN HALF OF THE CWA...AND ACROSS THE CWA
ON FRIDAY. DETAILS WILL HAVE TO BE REFINED LATER.
FRIDAY NIGHT THROUGH SUNDAY...PATTERN REMAINS UNSETTLED RIGHT ON
THROUGH THE WEEKEND AS PESKY CLOSED LOW MAKES SLOW PROGRESS INTO THE
GREAT LAKES. SHOWERS AND STORMS APPEAR MOST LIKELY ACROSS THE GREAT
LAKES REGION FRIDAY NIGHT INTO SATURDAY AS THE ASSOCIATED SFC FRONT
AND UPPER JET CORE PRESS INTO THE GREAT LAKES REGION...AND WILL HAVE
HIGHEST POPS DURING THIS TIME. AFTER FROPA...SUNDAY SHAPING UP TO BE
COOL AND DAMP ONCE AGAIN AS LIGHTER PRECIP LINGERS AND TEMPS DIP
BACK BELOW NORMAL.
MONDAY THROUGH WEDNESDAY...MID LEVEL TROUGH AND CORE OF COLD AIR
SLOWLY RETREATS EASTWARD ON MONDAY FOLLOWED BY LOWER AMPLITUDE
RIDGING FOR TUESDAY INTO WEDNESDAY. LARGE EXPANSE OF CANADIAN HIGH
PRESSURE SETTLES IN FOR MONDAY AND TUESDAY WHICH WILL CLEAR THINGS
OUT AND MAY LEAD MORE FROST POTENTIAL BOTH MONDAY AND TUESDAY
MORNING. DAYTIME TEMPS REBOUND FOR TUESDAY AND WEDNESDAY BACK CLOSE
TO NORMAL. HOWEVER...YET ANOTHER TROUGH IS SLATED TO BE DIPPING INTO
THE UPPER MIDWEST/WESTERN GREAT LAKES AROUND MIDWEEK BRINGING
ADDITIONAL RAIN CHANCES TO THE REGION TO ROUND OUT THE EXTENDED
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1258 AM EDT THU MAY 30 2013
FOG OVERNIGHT AT APN/PLN. SMALL CHANCES FOR SHRA/TSRA THURSDAY
AFTERNOON/EARLY EVENING.
A WEAK RIDGE OF HIGH PRESSURE HAS SHIFTED EAST TO THE EASTERN GREAT
LAKES. THAT WILL ALLOW WARM/MOIST SOUTHERLY FLOW TO RETURN TO THE
REGION THURSDAY. MARINE FOG/STRATUS HAS RETURNED TO APN WITH A LIGHT
SE WIND OFF OF HURON...WHILE PLN HAS SEEN OLD FASHIONED RADIATIONAL
FOG FORM. BOTH SITES ARE EXPECTED TO BE LIFR FOR THE BULK OF THE
OVERNIGHT...THOUGH SOME SLIGHT IMPROVEMENT MAY OCCUR AS CIRRUS
INCREASES OVERHEAD AND SLOWS THE COOLING PROCESS DOWN LOW. TVC/MBL
WILL SEE MUCH LESS IN THE WAY OF FOG...THOUGH COULD DIP INTO MVFR
TERRITORY AT TIMES. CONDITIONS WILL IMPROVE TO VFR AT ALL SITES
THURSDAY MORNING.
A CU FIELD WILL DEVELOP THURSDAY IN A WARM/MUGGY AIR MASS. SOME
SHRA/TSRA WILL TRY TO GET GOING IN THE AFTERNOON. THE BEST CHANCE
FOR THIS WILL BE INLAND FROM LAKE MI...AND WILL HAVE VCSH MENTIONED
ONLY AT PLN/APN IN THE AFTERNOON.
LIGHT WINDS OVERNIGHT. SOUTH WINDS THURSDAY...BREEZIEST AT MBL.
&&
.MARINE...
ISSUED AT 432 PM EDT WED MAY 29 2013
WINDS NOT EXPECTED TO BE MUCH OF AN ISSUE THROUGH TONIGHT...GENERAL
SOUTHWEST GRADIENT WIND WITH SOME LAKE BREEZE INFLUENCE ON WHITEFISH
BAY AND FAR NORTHERN LAKE HURON NEARSHORE ZONES. WINDS WILL BECOME
MORE SOUTHERLY TONIGHT. REDUCED VISIBILITIES IN AREAS OF FOG AND
HAZE WILL BE AN ISSUE THROUGH THURSDAY GIVEN RELATIVELY HUMID AIR
MASS IN PLACE INTERACTING WITH COLDER LAKE WATERS. SOUTHERLY WINDS
WILL INCREASE BY FRIDAY AFTERNOON...WITH SMALL CRAFT ADVISORIES
LIKELY NEEDED ACROSS A MAJORITY OF THE NEARSHORE ZONES.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JPB
SYNOPSIS...KAB
SHORT TERM...AJS
LONG TERM...TBA
AVIATION...JZ
MARINE...AJS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
353 AM CDT THU MAY 30 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 353 AM CDT THU MAY 30 2013
A VERY ACTIVE SHORT TERM IS IN STORE AS A POTENT UPPER WAVE WORKS
ACROSS THE NATIONS MIDSECTION. H5 RAP ANALYSIS SHOWS A CLOSED LOW
HAS DEVELOPED NEAR THE BLACK HILLS THIS MORNING...WITH A NEGATIVELY
TITLED TROUGH EXTENDING FROM THERE DOWN TO NORTHEAST TEXAS. THE
RADAR MOSAIC WEDNESDAY WAS CRAMMED FULL OF CONVECTION FROM HERE ALL
THE WAY DOWN TO TEXAS...WHICH MEANS WITHIN THIS LARGE SCALE TROUGH
THERE ARE NUMEROUS LEFT OVER WAVES/MCVS. ONE SUCH WAVE IS OVER SW IA
THAT WILL SWING THROUGH HERE IN THE LATE MORNING. THE MAIN SYNOPTIC
UPPER WAVE WILL BEGIN WORKING ACROSS MN THIS AFTERNOON AND EVENING.
TO GO ALONG WITH ALL OF THE WAVES...A 50 KT LLJ IS CURRENTLY BLOWING
ACROSS MN. THIS LLJ WILL SLOWLY DIMINISH THROUGH THE MORNING...BUT A
MUCH STRONGER PUSH CURRENTLY OVER OK/KS WILL COME UP INTO SE MN/WRN
WI THIS AFTERNOON/EVENING WITH THE PRIMARY SYNOPTIC WAVE.
AT THE SFC...A 995 MB SFC LOW CAN BE FOUND NEAR PIERRE SOUTH
DAKOTA...WITH A WARM FRONT SITTING ACROSS CENTRAL MN. DURING THE
SHORT TERM...THIS LOW WILL BECOME OCCLUDED AND SLOWLY MEANDER NORTH
INTO NODAK. THE WARM FRONT WILL CONTINUE TO MOVE NORTH
TODAY...EVENTUALLY SETTLING ALONG THE INTERNATIONAL BORDER. BACK TO
THE WEST...A COLD FRONT MOVING ACROSS SODAK TODAY WILL BE ENTERING
WRN MN BY THE END OF THE PERIOD.
FOR TODAY...EXPECT A BRIEF LULL IN ACTIVITY THIS MORNING AS WE WAIT
FOR THE WAVE OVER SW IA TO GET HERE AROUND 15Z. FORECAST SOUNDINGS
ACROSS THE ENTIRE CWA SHOW VERY LITTLE IF ANY CAPPING...SO EXPECT
SHOWERS AND STORMS TO DEVELOP QUICKLY THIS MORNING ONCE A LITTLE
DAYTIME HEATING KICKS IN. SINCE WE WILL NOT BE ABLE TO BUILD MUCH
INSTABILITY THANKS TO DENSE CLOUD COVER AND THE FACT THAT ONCE A
LITTLE DEVELOPS THE ATMO WILL QUICKLY CONSUME IT...THE SEVERE THREAT
LOOKS FAIRLY LOW TODAY. FOR SEVERE WEATHER...WILL HAVE TO WATCH THAT
SECOND LLJ WORKING UP IN THE AFTERNOON. BY 00Z THE RAP HAS 50 KT
WINDS AT H85 UP INTO OUR WI CWA. LIKE YESTERDAY...THIS COULD LEAD TO
THE THREAT FOR BOWING LINE SEGMENTS AND DAMAGING WINDS.
AS FOR ANY HYDROLOGY ISSUES TODAY...THE ONLY AREA THAT WILL
PROBABLY HAVE TO BE WATCHED IS THE EAU CLAIRE AREA. THEY SET A DAILY
RAINFALL RECORD YESTERDAY AND WILL BE UNDER THE GUN FOR THE SECOND
LLJ SURGE THIS AFTERNOON...WITH THE POTENTIAL FOR SOME TRAINING OF
STORMS THIS AFTERNOON AND EVENING.
TONIGHT...THE COLD FRONT WILL START ENTERING WRN MN WHILE THE LLJ
WORKS INTO CENTRAL/ERN WI. THIS SHOULD MOVE THE HEAVY RAIN THREAT
EAST OF THE MPX CWA TONIGHT. HOWEVER...HI-RES CAMS SHOW SCT RETURNS
CONTINUING THROUGH THE NIGHT AHEAD OF THE FRONT...SO HAVE POPS
SLOWLY RAMPING DOWN FROM LIKELIES TO START THE EVENING...DOWN TO 50%
POPS OR LESS BY 12Z FRIDAY.
FOR TEMPERATURES...GIVEN ALL OF THE CLOUD COVER...IT WILL NOT BE AN
OVERLY WARM WARM SECTOR TODAY...WITH HIGHS LIKELY STAYING IN THE MID
TO UPPER 70S...DESPITE H85 TEMPS BEING UP AROUND +15C. FOR
TONIGHT...MIXED LAYER DEWPS ON THE NAM DROP INTO THE 40S BEHIND THE
FRONT...SO LOWS IN THE WRN CWA COULD END UP BEING A FEW DEGREES
COOLER THAN WHAT IS CURRENTLY INDICATED.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 353 AM CDT THU MAY 30 2013
MODELS INDICATE RATHER STRONG TROUGH AXIS WORKING THROUGH THE
AREA BY FRIDAY MORNING. THIS SHOULD WORK MUCH OF THE RAIN AND
THUNDER TO THE NORTH AND EAST OF THE AREA LATE THURSDAY NIGHT.
THIS SHOULD WORK A DRY SLOT NORTHEAST INTO SOUTHWEST PORITON OF
THE CWA DURING FRIDAY MORNING. THE UPPER CIRCULATION THEN MOVES A
FRONTAL BOUNDARY EAST ACROSS EASTERN HALF OF THE CWA FRIDAY
AFTERNOON. THE DETERMINISTIC MODELS ARE INDICATING MODEST
DESTABILIZATION ACROSS THE EASTERN HALF OF THE AREA...WITH ML
MUCAPE INCREASING TO 1500/2000 J/KG. SHEAR INCREASES INTO THE
AFTERNOON...ESPECIALLY INTO WESTERN WISCONSIN. THE ONLY INHIBITING
FACTOR FOR CONVECTIVE INITIATION ALONG THE FRONT APPEARS TO BE
RATHER WEAK SURFACE CONVERGENCE..WITH WINDS S-SW ALONG THE
BOUNDARY. THE HIRES MODELS ARE SHOWING RATHER ROBUST CONVECTION
DEVELOPING ALONG THE BOUNDAY AS IT MOVES INTO EASTERN MINNESOTA
FRIDAY AFTERNOON. WILL HAVE TO MONITOR THIS SITUATION INTO
FRIDAY...AS SEVERE WEATHER THREAT IS FORECAST TO BE LOW AT THIS
TIME.
FRONT EXITS TO THE EAST FRIDAY NIGHT TAKING THE HEAVY CONVECTIVE
POTENTIAL WITH IT. THIS WILL LEAVE THE UPPER LOW OVER THE AREA
THROUGH AT LEAST SATURDAY. SHOWERS LOOK TO BE A FAIR BET
ESPECIALLY LATER IN THE DAY AS THE LOW MOVES EAST. WITH ABUNDANT
CLOUD COVER...WILL BE LITTLE IN THE WAY OF HEATING...SO CONVECTIVE
POTENTIAL IS LOW. CLEARING SHOULD MOVE INTO THE AREA LATER
SATURDAY NIGHT...AND SUNDAY LOOKS LIKE THE BEST DAY OF THE
WEEKEND...WITH SUNSHINE AND MILD TEMPERATURES.
THE EXTENDED PORTION OF THE FORECAST STARTS OFF RATHER
COOL...ESPECIALLY OVER THE EASTERN CWA MONDAY MORNING. THERE MAY
EVEN BE A FROST POTENTIAL OVER A PORTION OF WEST CENTRAL
WISCONSIN. THE NEXT WEATHER SYSTEM MOVES INTO THE AREA LATER
MONDAY WITH SOME SHOWERS INTO THE WESTERN CWA. THE 00Z GFS AND
ECMWF DIVERGE SOMEWHAT ON THE OVERALL EVOLUTION AND MOVEMENT OF
THE NEXT LOW PRESSURE SYSTEM THAT MOVES ACROSS THE NORTHERN STATES
THROUGH MUCH OF NEXT WEEK. IT DOES APPEAR THE THREAT OF MORE
SHOWERS AND THUNDERSTORMS RETURNS BY MIDWEEK...WITH TEMPERATURES
REMAINING BELOW NORMAL THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1254 AM CDT THU MAY 30 2013
WITH THE NOSE OF A 40 KT LLJ SLOWLY WORKING ACROSS THE MPX AREA
THIS PERIOD...FULLY EXPECT SEVERAL ROUNDS OF SHRA/TSRA THE REST OF
TONIGHT THROUGH THU NIGHT. CONFIDENCE IS HIGH IN CONVECTIVE
OCCURRENCE...BUT LIMITED ON EXACT TIMING AND PLACEMENT BEYOND THE
FIRST 6 HOURS OF THE TAF...SO STUCK WITH LOTS OF VC GROUPS FOR NOW.
STORM INTENSITY HAS BEEN SLOWLY DIMINISHING THE LAST COUPLE OF
HOURS...AND EXPECT THIS TO CONTINUE THE REST OF THE EVENING.
EXPECT A BRIEF LULL IN ACTIVITY LATE TONIGHT INTO THU
MORNING...BEFORE SHRA/TSRA ACTIVITY QUICKLY FIRES UP AGAIN AFTER
15Z. SOUNDINGS THROUGH THURSDAY SHOW VERY LITTLE INHIBITION...SO
SHOULD NOT TAKE MUCH TO GET STORMS GOING THIS WHOLE PERIOD. FOR
CIGS...EXPECT THEM TO REMAIN MAINLY VFR OUTSIDE OF SHRA/TSRA
ACTIVITY...THOUGH GIVEN DEGREE OF LOW LEVEL MOISTURE IN PLACE...WE
COULD SEE SOME POCKETS OF MVFR CIGS DEVELOP THIS MORNING BEFORE
QUICKLY LIFTING.
KMSP...STORMS STARTING TO DIMINISH IN INTENSITY THIS EVENING AND
EXPECT A LULL IN ACTIVITY BETWEEN ABOUT 10Z AND 15Z AS THE ATMO
RECHARGES. EXPECT A QUICK RETURN TO SHRA/TSRA ACTIVITY IN THE
MORNING...AS EVIDENCED BY THE HRRR...WHICH HAS STORMS DEVELOPING
OVER MN BY 16Z. WINDS WILL REMAIN STRONG THROUGH THE PERIOD...BUT
WILL BE FAIRLY PERSISTENT BETWEEN 140 AND 170 DEGS OUTSIDE OF ANY
STORMS. ONLY TIME PERSISTENT MVFR CIGS ARE EXPECTED THIS PERIOD IS
DURING PERIODS OF SHRA/TSRA.
/OUTLOOK FOR KMSP/
FRI...SCT MVFR CIGS. SHRA/TSRA LIKELY. WINDS SW 10-15 KTS.
SAT...MVFR CIGS POSSIBLE. SHRA LIKELY. WINDS WNW 5-10 KTS.
SUN...MVFR CIGS POSSIBLE EARLY. WINDS N 5 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...DWE
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS GLASGOW MT
258 AM MDT THU MAY 30 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SATURDAY...
RAIN...HEAVY IN SOME AREAS... CONTINUE TO FALL OVER THE SW HALF OF
THE FORECAST AREA EARLY THIS MORNING. RAINFALL TOTALS HAVE
EXCEEDED 2 INCHES AT JORDAN AIRPORT IN CENTRAL GARFIELD COUNTY AND
AT BIG SHEEP MOUNTAIN RAWS IN WESTERN PRAIRIE COUNTY SINCE
WEDNESDAY AFTERNOON. THIS RAIN IS FOCUSED ALONG AN INVERTED
SURFACE TROUGH THAT IS NEAR WINNETT... FORSYTHE AND BROADUS OR JUST
SOUTH OF THE HEAVY PRECIP BAND.
AN UPPER LOW OVER NE WYOMING IS STACKED WITH THE SURFACE LOW OVER
NEBRASKA AT 09Z. THE SURFACE LOW WILL MOVE NORTH TODAY TAKING THE
RAIN NORTH WITH IT. THIS WILL SPREAD THE RAIN NORTH INTO THE NE
HALF OF THE FORECAST AREA THAT HAS STAYED DRY OVERNIGHT. BY THIS
EVENING...THE SURFACE LOW WILL BE IN NORTH DAKOTA WHILE THE UPPER
LOW WILL BE IN SOUTH DAKOTA. EASTERN MONTANA WILL BE IN THE WRAP
AROUND MOISTURE IN THIS SYSTEM AND WITH THE AID OF A TROWAL
(TROUGH OF WARM AIR ALOFT)... MODERATE TO HEAVY RAIN WILL CONTINUE
OVER THE AREA INTO FRIDAY. AN ADDITIONAL 2+ INCHES OF RAIN CAN BE
EXPECTED WITH THIS SYSTEM. WILL MAINTAIN FLOOD WATCH FOR THE
ENTIRE FORECAST AREA THROUGH FRIDAY.
THE SYSTEM WILL BEGIN TO MOVE TO THE EAST FRIDAY NIGHT WHICH WILL
TAKE THE MOISTURE WITH. DRIER AIR WILL MOVE IN FROM THE NORTH
ENDING THE RAIN.
A SHORTWAVE RIDGE AND SURFACE HIGH PRESSURE WILL BRING DRY
WEATHER ON SATURDAY. FORRESTER
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
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...
VFR TO MVFR VISIBILITIES UNDER RAIN SHOWERS. IFR CEILINGS POSSIBLE
ELSEWHERE.
ON AND OFF SHOWERS WILL CONTINUE THROUGH KGDV AND KGGW WHILE KOLF
AND KSDY SHOULD REMAIN CLEAR OF RAIN THROUGH 09Z. HRRR GUIDANCE
SUGGESTS A WINDOW OF CLEARING RAIN BETWEEN 09Z TO 12Z MOVING FROM
EAST TO WEST WITH THE KGGW TERMINAL POSSIBLY BEING CLEAR OF RAIN
THROUGH NEARLY 15Z. AFTERWARD... ANOTHER LARGE BAND OF RAIN WITH
MVFR CONDITIONS IS PROGGED THROUGH THE END OF THE TAF CYCLE.
WHILE SOME AREAS MAY CLEAR FROM RAIN...RAIN FREE AREAS MAY
ACTUALLY BECOME WORSE WITH TEMPORARY IFR CONDIITONS DUE TO CEILINGS
DROPPING IN WHAT WOULD RAPIDLY BECOME COLDER LOCATIONS.
WINDS WILL BE EASTERLY BETWEEN 5 AND 15 KTS THROUGH TONIGHT...
THEN BECOME NORTHEASTERLY AND INCREASING TO 10 TO 20 KTS AFTER SUN
UP.
GAH
&&
.HYDROLOGY...
WITH RAINFALL HAVING EXCEEDED 2 INCHES ACROSS PARTS OF GARFIELD
AND WESTERN PRAIRIE COUNTIES BASED ON AUTOMATED GAGES AT JORDAN
AIRPORT AND BIG SHEEP MOUNTAIN RAWS... HAVE ISSUED A FLOOD WARNING
THAT IS IN EFFECT THROUGH 730 PM THIS EVENING. A FLOOD WATCH
REMAINS IN EFFECT FOR NORTHEAST MONTANA THROUGH FRIDAY. THIS WILL
LEAD TO RISES IN STREAMS AND CREEKS WITH MAINSTEM RIVERS ALSO
SEEING RISES BY THE WEEKEND INTO NEXT WEEK.
AN ADDITIONAL 2+ INCHES OF RAIN IS LIKELY BETWEEN TODAY AND FRIDAY
BEFORE THE SYSTEM MOVES TO THE EAST. FORRESTER
&&
.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
NWS ALBUQUERQUE NM
325 AM MDT THU MAY 30 2013
.DISCUSSION...
DRYLINE HAS SO FAR STAYED TO THE EAST OF NEW MEXICO THIS MORNING AND
ALTHOUGH IT/S FAIRLY CLOSE TO HOBBS DON/T EXPECT IT TO GET MUCH
FARTHER WEST IF AT ALL. IN THE NORTHEAST DEWPOINTS HAVE COME UP AS
THE SFC LOW SHIFTED INTO THE TX/OK PANHANDLES BUT THIS INCREASE
LIKELY WON/T LAST LONG WITH THE RUC FORECASTING A WEAK SFC LOW TO
REDEVELOP OVER SE CO BY MIDDAY. MODELS ALSO SHOW CURRENT BATCH OF
MID LEVEL MOISTURE EXITING BY MIDDAY. UPPER JET TO RETREAT NWD TODAY
BUT WILL BE STRETCHED OVER FAR NRN NM AND COLORADO...COMBINED WITH
THE SFC LOW PLACEMENT WILL HAVE LOW END WIND ADVY OVER SOME OF THE
NORTH CENTRAL/NORTHEAST SOUTH TO CLINES CORNERS.
DRY INTO FRIDAY NIGHT. ANOTHER WINDY DAY ON FRIDAY WITH CRITICAL
FIRE WX CONDITIONS POSSIBLE. ANOTHER BATCH OF MID LEVEL MOISTURE
PASSES OVERHEAD TONIGHT AND FRIDAY BUT ANYTHING MORE THAN A FEW
SPRINKLES OUT OF IT...IF THAT...WOULD BE A SURPRISE.
SURFACE FRONT PUSHES THROUGH FRIDAY NIGHT WITH THE BACK DOOR FRONT
INTO THE EAST SATURDAY. LOW LEVEL MOISTURE APPEARS TO MOVE IN FROM
THE SOUTH AND SOUTHEAST WITH INCREASING INSTAB SO WENT AHEAD AND
SPREAD SOME SMALL POPS FROM THE EAST SLOPES OF THE SOUTH CENTRAL
MOUNTAIN ACROSS CHAVES COUNTY AND NORTHEAST ALONG THE TX BORDER
SATURDAY AFTERNOON ALTHOUGH FOR NOW BEST CONFIDENCE IS IN THE
SOUTHEAST. ANOTHER BLOB OF MID LEVEL MOISTURE TO MIGRATE OVER THE
SOUTHERN HALF OF THE STATE AND COULD NOT RULE OUT A FEW SPRINKLES
UNDERNEATH IT...BUT LEFT MENTION OUT OF FCST FOR NOW. IN FACT THE
ADJMET GUIDANCE DOES PAINT SOME LOW POPS OVER THE SOUTHWEST MTS.
INCREASED POPS SOMEWHAT SUNDAY ESPECIALLY ALONG THE CENTRAL MT
CHAIN. LEFT THE MENTION OF DRY CONVECTION FROM THE RGV WWD ALTHOUGH
COULD BE A MIX WITH AT LEAST SOME MEAGER MEASURABLE PCPN DEPENDING
IF THE SURGE IS AS STRONG AS DEPICTED SO FAR. HOWEVER...MONDAY
STARTS TO DRY OUT AND TUESDAY EVEN MORE SO. REMOVED THE POPS IN THE
EAST FOR TUESDAY NIGHT...AND PROBABLY SHOULD HAVE FOR TUESDAY AS
WELL AS RIGHT NOW IT LOOKS DRY. ANOTHER BACKDOOR FRONT WEDNESDAY
LOOKS TO PUSH INTO THE RGV WEDNESDAY NIGHT...SO POPS/WX GRIDS FOR
MID TO LATE WEEK HAVE BEEN UPDATED.
&&
.FIRE WEATHER...
...WIDESPREAD CRITICAL FIRE WEATHER CONDITIONS DUE TO STRONG WIND
AND LOW HUMIDITY FOR MUCH OF NORTHERN AND CENTRAL NEW MEXICO THROUGH
FRIDAY...
...DRY LIGHTNING THREAT INCREASING SUNDAY CENTRAL/WEST...
MOVING INTO DAY 2 OF A PROTRACTED CRITICAL FIRE WEATHER PATTERN THAT
WILL EXTEND THROUGH FRIDAY. THEREAFTER...FAR LESS WIND BUT GROWING
CONFIDENCE IN A SUBSTANTIAL WESTERLY PUSH OF LOWER LEVEL MOISTURE
THAT WILL RESULT IN A SIGNIFICANT DRY LIGHTNING THREAT FOR
CENTRAL/WESTERN AREAS BY SUNDAY.
SATURDAY LOOKS TO BE A CLASSIC TRANSITION DAY AS RICHER LOW LEVEL
MOISTURE INITIALLY MAKES A RETURN TO THE EC/SE PLAINS AS SURFACE
WINDS VEER TO SELY AND TAPS INTO A NOW SEMI-PERMANENT POOL OF
GULFMEX MOISTURE. POTENTIAL FOR SOME DRIER STORMS ALONG THE EAST
SLOPES OF THE CENTRAL/SC MOUNTAIN SATURDAY PM. HIGHER DEW POINT AIR
ALSO CREEPING NORTHWARD ALONG THE RGV AND THAT COUPLED WITH A SUBTLE
AND ALWAYS SNEAKY UPTICK IN MID-LEVEL MOISTURE AS THE UPPER RIDGE
EXPANDS/BUILDS NORTHWARD COULD RESULT IN AT LEAST AN ISOLATED DRY
LIGHTNING THREAT OVER THE WC/SW HIGHER TERRAIN AS EARLY AS SATURDAY
AFTERNOON OR EVENING. THIS WILL BE CLOSELY MONITORED.
EVEN THE SLIGHTEST UPTICK IN LOWER/MID LEVEL MOISTURE IN THE
PRESENCE OF VERY STEEP LAPSE RATES THAT ARE TYPICAL OF THE
DEVELOPING PATTERN THIS WEEKEND SEEMS TO RESULT IN MORE THAN
EXPECTED BUILDUPS/VIRGA AND DRY CG/S. WE SHALL SEE. SUNDAY
AFTERNOON/EVENING LOOKING TO BE THE MORE CRITICAL DAY WITH RESPECT
TO DRY LIGHTNING THOUGH MONDAY COULD BE FAIRLY ACTIVE EAST OF THE
DIVIDE.
IN THE MEANTIME...LARGE-SCALE UPPER TROUGH SLOWLY PIVOTING NORTHEAST
FROM THE CENTRAL/NORTHERN ROCKIES EARLY THIS MORNING. BASE OF THE
TROUGH TRANSLATED EASTWARD OVER OUR AREA THIS PAST NIGHT AND PRESENT
INDICATIONS ARE THAT THE STRONGEST MID-LEVEL WINDS WILL PASS
OVERHEAD BEFORE MIDDAY. THAT SAID...AN ANOMALOUSLY STRONG UPPER
LEVEL JET ORIENTED NW TO SE FROM THE GREAT BASIN TO THE FOUR CORNERS
REGION WILL NOT SHIFT NORTHWARD APPRECIABLY TODAY. AS A
RESULT...WIND SPEEDS THOUGH A BIT LESS THAN YESTERDAY WILL STILL BE
SIGNIFICANT WITH FREQUENT GUSTS OF 35-40 MPH ACROSS THE NORTH.
SURFACE LOW NOT AS FAVORABLE EITHER. NO CHANGES TO THE FIRE
WEATHER WATCH FOR FRIDAY THOUGH BELT OF STRONGEST WINDS DO SHIFT
SOUTHWARD PER PREVIOUS FORECAST. VERY DEEP MIXING CONTINUES TODAY
BEFORE MAX MIXING HEIGHTS TREND DOWNWARD SLIGHTLY ON FRIDAY. LOWEST
RH VALUES CENTRAL VALLEY CORRIDOR AND IN THE EAST.
EXTENDED MODELS STILL TRENDING DRIER/BREEZIER EARLY NEXT WORK WEEK
FOLLOWING OUR LIGHTNING PERIOD. BACK TO VERY DEEP MIXING AND GUSTY
AFTERNOON/EVENING PERIODS THOUGH TOO EARLY TO GAUGE STRENGTH OF ANY
SUSTAINED WINDY PERIODS. KJ
&&
.AVIATION...
06Z TAF CYCLE
TROUGH ALOFT EXTENDING FROM NORTHERN ROCKIES SOUTHWARD ACROSS
EASTERN NM TO THE TX BIG BEND COUNTRY...AS SURFACE TROUGH EXTENDS
FROM CENTRAL NEBRASKA ACROSS THE TX PANHANDLE. CLOUD COVER AOA
BKN/OVC100 MOVING EAST ACROSS THE STATE ALONG INTERSTATE 40
CORRIDOR WILL DISSIPATE BY 12Z THU MORNING. GUSTY WEST WINDS
REDEVELOPING RAPIDLY FROM 14Z ONWARD ACROSS THE EAST SLOPES OF OF
THE CENTRAL MTS...AND THEN STATEWIDE BY 18Z. AREAS OF BLOWING DUST
WILL DROP VIZ TO 5SM OR LESS AT TIMES...ESPECIALLY OVER THE EASTERN
PLAINS.
SHY
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 81 49 82 42 / 0 0 0 0
DULCE........................... 73 41 75 32 / 0 0 0 0
CUBA............................ 77 43 77 40 / 0 0 0 0
GALLUP.......................... 81 45 82 37 / 0 0 0 0
EL MORRO........................ 79 44 81 40 / 0 0 0 0
GRANTS.......................... 82 47 84 39 / 0 0 0 0
QUEMADO......................... 81 47 83 43 / 0 0 0 0
GLENWOOD........................ 85 49 87 57 / 0 0 0 0
CHAMA........................... 71 37 70 30 / 5 0 5 5
LOS ALAMOS...................... 80 45 81 41 / 0 0 0 0
PECOS........................... 78 47 80 44 / 0 0 0 0
CERRO/QUESTA.................... 73 38 74 32 / 0 0 0 0
RED RIVER....................... 64 36 63 36 / 0 0 0 0
ANGEL FIRE...................... 69 38 71 34 / 0 0 0 0
TAOS............................ 75 40 77 34 / 0 0 0 0
MORA............................ 75 42 78 39 / 0 0 0 0
ESPANOLA........................ 83 45 84 45 / 0 0 0 0
SANTA FE........................ 80 45 80 43 / 0 0 0 0
SANTA FE AIRPORT................ 82 49 84 45 / 0 0 0 0
ALBUQUERQUE FOOTHILLS........... 83 56 85 50 / 0 0 0 0
ALBUQUERQUE HEIGHTS............. 85 60 88 56 / 0 0 0 0
ALBUQUERQUE VALLEY.............. 86 54 90 56 / 0 0 0 0
ALBUQUERQUE WEST MESA........... 86 58 88 54 / 0 0 0 0
LOS LUNAS....................... 88 60 91 56 / 0 0 0 0
RIO RANCHO...................... 85 58 87 54 / 0 0 0 0
SOCORRO......................... 90 62 94 59 / 0 0 0 0
SANDIA PARK/CEDAR CREST......... 82 51 83 49 / 0 0 0 0
TIJERAS......................... 83 55 85 48 / 0 0 0 0
MORIARTY/ESTANCIA............... 82 50 84 47 / 0 0 0 0
CLINES CORNERS.................. 81 51 80 47 / 0 0 0 0
GRAN QUIVIRA.................... 84 53 85 50 / 0 0 0 0
CARRIZOZO....................... 84 59 87 56 / 0 0 0 0
RUIDOSO......................... 76 57 80 57 / 0 0 0 0
CAPULIN......................... 80 48 82 40 / 0 0 0 5
RATON........................... 81 44 84 40 / 0 0 0 5
SPRINGER........................ 82 43 84 40 / 0 0 0 0
LAS VEGAS....................... 80 48 82 41 / 0 0 0 0
CLAYTON......................... 87 52 86 48 / 0 0 0 5
ROY............................. 84 51 85 46 / 0 0 0 5
CONCHAS......................... 90 53 91 52 / 0 0 0 0
SANTA ROSA...................... 91 54 92 52 / 0 0 0 0
TUCUMCARI....................... 95 55 95 53 / 0 0 0 5
CLOVIS.......................... 92 57 94 56 / 0 0 0 5
PORTALES........................ 94 57 95 56 / 0 0 0 5
FORT SUMNER..................... 94 59 96 55 / 0 0 0 0
ROSWELL......................... 96 64 99 62 / 0 0 0 0
PICACHO......................... 89 63 92 59 / 0 0 0 0
ELK............................. 84 62 88 58 / 0 0 0 0
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 11 AM THIS MORNING TO 8 PM MDT THIS EVENING
FOR THE FOLLOWING ZONES...NMZ101>104-106>108.
FIRE WEATHER WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING FOR
THE FOLLOWING ZONES...NMZ101>108.
WIND ADVISORY FROM 10 AM THIS MORNING TO 9 PM MDT THIS EVENING FOR
THE FOLLOWING ZONES...NMZ510>516-523-527>529.
&&
$$
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1232 AM CDT THU MAY 30 2013
.UPDATE...
ISSUED AT 1231 AM CDT THU MAY 30 2013
CURRENT FORECAST IS ON TRACK WITH HOURLY GRIDS CLOSELY MATCHING
LATEST OBSERVATIONS. WATER VAPOR SHOWS NEGATIVELY TILTED TROUGH
EXTENDING FROM CENTRAL MONTANA TO NEBRASKA/SOUTH DAKOTA CONTINUING
TO PIVOT TOWARD NORTH DAKOTA. ASSOCIATED SURFACE LOW IS LOCATED
OVER SOUTH DAKOTA. RELATIVELY MOIST DEWPOINTS IN THE LOW 60S ARE
ADVECTING INTO SOUTHEAST NORTH DAKOTA WITH WARM FRONT GENERALLY IN
THE VICINITY OF THE ND/SD BORDER. SHOWERS AND ISOLATED/SCATTERED
THUNDERSTORMS HAVE EXPANDED THE PAST COUPLE HOURS ACROSS SOUTH
CENTRAL AND SOUTHEAST ND WITH THIS AREA MOVING TO THE
NORTHWEST...JUST ABOUT AT BISMARCK AT THIS TIME. MODELS ARE IN
DECENT AGREEMENT WITH SOME SLIGHT DIFFERENCES IN SURFACE LOW
LOCATION. UPPER TROUGH REFERENCED ABOVE WILL CUT OFF THURSDAY
MORNING RESULTING IN SURFACE LOW MOVING TO NORTH DAKOTA ON
THURSDAY AND REMAINING NEARLY STATIONARY THROUGH THURSDAY NIGHT.
UPDATE ISSUED AT 938 PM CDT WED MAY 29 2013
ONCE AGAIN...GIVEN THE LATEST RADAR TRENDS...THE 18 AND INCOMING
00 UTC DETERMINISTIC GUIDANCE AND 01 UTC RAP/HRRR SIMULATED
REFLECTIVITY FORECASTS...REDUCED POPS THROUGH 06 UTC FOR MUCH OF
THE AREA UNTIL THE ARRIVAL OF GREATER UPPER LEVEL FORCING AS
CONVECTION ACROSS SOUTH DAKOTA THROUGH NEBRASKA MAY ALSO BE
DISRUPTING MOISTURE TRANSPORT INTO NORTH DAKOTA. DO NOT ANTICIPATE
SEVERE WEATHER TONIGHT ACROSS WESTERN AND CENTRAL NORTH
DAKOTA...WITH A POTENTIAL RETURN OF THE THREAT TOMORROW AFTERNOON
AND EVENING DEPENDENT UPON HOW MUCH CLEARING/INSOLATION IS
ACHIEVED IN THE WARM SECTOR OF THE SURFACE LOW ACROSS SOUTH
CENTRAL NORTH DAKOTA.
UPDATE ISSUED AT 720 PM CDT WED MAY 29 2013
THE BIGGEST CHANGE WITH THIS UPDATE WAS TO REDUCE POPS...ESPECIALLY
ALONG AND NORTH OF US HIGHWAY 2...GIVEN THE LATEST RADAR TRENDS
AND THE 21 UTC HRRR SIMULATED REFLECTIVITY WHICH HAS MAINTAINED
CONTINUITY WITH PREVIOUS RUNS WHICH KEEP MUCH OF NORTHERN NORTH DAKOTA
PRECIPITATION FREE THROUGH AT LEAST 06 UTC. GIVEN THE MARGINAL
INSTABILITY AND SHEAR...THE SMALL WINDOW FOR SEVERE HAIL AND/OR
WINDS ACROSS THE JAMES RIVER VALLEY APPEARS TO BE QUICKLY CLOSING
AND WILL FOCUS ON HEAVY RAIN MONITORING OVER THE SATURATED AREAS
OF SOUTHERN NORTH DAKOTA.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 405 PM CDT WED MAY 29 2013
MAIN PROBLEM IN THE SHORT TERM PERIOD WILL BE PRECIPITATION
AMOUNTS...PLACEMENT AND TIMING.
CURRENTLY...SURFACE LOW PRESSURE OVER THE CENTRAL PLAINS WITH A
WARM FRONT EXTENDING INTO EASTERN SOUTH DAKOTA AND SOUTHERN
MINNESOTA. STRONG NEGATIVELY TILTED UPPER LEVEL TROUGH FROM THE
NORTHWEST U.S. INTO THE CENTRAL ROCKIES. CURRENT CONVECTION IN OUR
AREA IS LINING UP WITH THE THE STRONG WARM ADVECTION OVER THE
EASTERN DAKOTAS INTO MINNESOTA...AS WELL AS STRONG UPPER LEVEL
DIVERGENCE OVER EASTERN MONTANA.
TONIGHT...THE UPPER LEVEL WAVE WILL LIFT NORTHWARD INTO THE
NORTHERN HIGH PLAINS WITH THE SURFACE LOW TRACKING NORTH THROUGH
SOUTH DAKOTA. THIS WILL BRING INCREASING SHOWERS AND POSSIBLY SOME
THUNDERSTORMS TO WESTERN AND CENTRAL NORTH DAKOTA. ALTHOUGH WE DO
THINK MOST AREAS WILL RECEIVE PRECIPITATION...WE HAVE CONTINUED
THE TREND OF DELAYING THE ONSET...AND CUTTING BACK A LITTLE ON THE
AMOUNTS. AGAIN..WE ARE IN A BIT OF A LULL BETWEEN THE STRONG WARM
ADVECTION TO OUR EAST...AND THE STRONG FORCING AND DIVERGENT FLOW
ALOFT ASSOCIATED WITH THE UPPER LEVEL SYSTEM TO OUR WEST.
THURSDAY...THE UPPER LEVEL LOW CONTINUES TO LIFT NORTH THROUGH
EASTERN MONTANA...WHILE THE SURFACE LOW LIFTS NORTH TO NEAR
BISMARCK...THEN NORTHWEST TOWARDS WILLISTON. THIS PLACEMENT WOULD
BRING GREATEST PRECIPITATION AMOUNTS TO THE NORTHERN HALF OF THE
CWA...WITH DRIER AIR WORKING FROM SOUTH TO NORTH THURSDAY
AFTERNOON. THIS WOULD BRING AN END TO PRECIPITATION ACROSS THE
SOUTH HALF OF THE CWA...BUT COULD ALSO ALLOW FOR A PERIOD OF
DESTABILIZATION THURSDAY AFTERNOON IN THE DRIER AIR. WITH THE
SURFACE AND UPPER LOWS JUST WEST...THIS WOULD INCREASE THE RISK OF
THUNDERSTORMS IN A HIGH SHEAR ENVIRONMENT. DUE TO SOME MODEL AND
TIMING UNCERTAINTIES WILL NOT MENTION SEVERE AT THIS TIME...AND
LET LATER SHIFTS UPDATE AS NEEDED.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 405 PM CDT WED MAY 29 2013
WET AND COOL WEATHER REMAINS OVER THE NORTHERN PLAINS THROUGH EARLY
SATURDAY...FOLLOWED BY QUIET CONDITIONS SATURDAY THROUGH SUNDAY
AFTERNOON...THEN A RETURN TO ACTIVE CONDITIONS SUNDAY NIGHT THROUGH
TUESDAY.
THE LONG TERM BEGINS THURSDAY EVENING WITH A CLOSED UPPER LEVEL LOW
CENTERED OVER SOUTHWEST ND/SOUTHEASTERN MONTANA...AND AN AREA OF
SURFACE LOW PRESSURE OVER WESTERN NORTH DAKOTA. ACTIVE WEATHER WILL
BE ONGOING AT THE START OF THE PERIOD WITH WIDESPREAD RAIN SHOWERS
AND ISOLATED THUNDERSTORMS ACROSS THE NORTH AND FAR WEST WRAPPING
AROUND THE UPPER LOW. OVER SOUTH CENTRAL AND SOUTHEASTERN NORTH
DAKOTA...A DRY SLOT IS EXPECTED TO PROVIDE SOME CLEARING THURSDAY
AFTERNOON INTO THURSDAY EVENING...WITH THE RESULTANT HEATING ACTING
TO INCREASE SURFACE INSTABILITY WITH UPWARDS TO NEAR 1500 J/KG OF
CAPE FORECAST NEAR A SFC COLD/OCCLUDED FRONT. MAY SEE ISOLATED
SEVERE STORMS DEVELOP GIVEN THE ADVERTISED INSTABILITY PERSISTING
INTO THE EVENING NEAR THE BOUNDARY.
LOW LINGERS ACROSS THE NORTHERN PLAINS THROUGH FRIDAY BEFORE
MORPHING INTO AN OPEN WAVE AND PUSHING OFF TO OUR EAST SATURDAY
AFTERNOON. AS THIS OCCURS...WILL SEE WRAP AROUND PRECIPITATION
SPREAD FROM WEST TO EAST FRIDAY MORNING THROUGH FRIDAY
EVENING...THEN DECREASING CLOUDS AND CHANCES FOR RAIN FROM
NORTHWEST TO SOUTHEAST FRIDAY NIGHT INTO SATURDAY. OVERALL EXPECT
UPWARDS TO AN ADDITIONAL ONE HALF INCH OF RAINFALL THURSDAY NIGHT
THROUGH SATURDAY MORNING ACROSS WEST AND CENTRAL ND.
DRY WEATHER REMAINS IN THE FORECAST SATURDAY NIGHT THROUGH SUNDAY
AFTERNOON WITH A SHORT WAVE RIDGE AND SURFACE HIGH PRESSURE BUILDING
EAST ACROSS THE NORTHERN PLAINS. ACTIVE WEATHER RESUMES SUNDAY NIGHT
INTO EARLY NEXT WEEK AS ANOTHER UPPER LOW/TROUGH PUSHES ACROSS THE
NORTHERN ROCKIES AND EVENTUALLY INTO THE NORTHERN PLAINS.
WELL BELOW NORMAL TEMPERATURES FRIDAY AND SATURDAY WITH HIGHS 55-65
AND LOWS IN THE UPPER 30S TO MID 40S. WILL NEED TO MONITOR FOR
POSSIBLE FROST SATURDAY NIGHT/SUNDAY MORNING WHEN WINDS ARE EXPECTED
TO BE LIGHT...SKIES CLEAR...AND SFC DEWPOINT TEMPS FORECAST TO FALL
AS LOW AS 35F DEGREES SOME AREAS. DAYTIME AND NIGHTTIME TEMPERATURES
MODERATE TOWARDS NORMAL SUNDAY-TUESDAY WITH HIGHS GENERALLY IN THE
60S AND LOW 45-55.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY)
ISSUED AT 1231 AM CDT THU MAY 30 2013
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO INCREASE IN COVERAGE
ACROSS WESTERN AND CENTRAL NORTH DAKOTA THROUGH THE NIGHT...WITH
FLIGHT CONDITIONS TRENDING TOWARDS MVFR/IFR AT ALL SITES IN MODERATE
RAIN AND LOW CEILINGS. DEPENDING ON HOW MUCH CLEARING THERE IS
THURSDAY AFTERNOON...STRONG TO SEVERE THUNDERSTORMS MAY BE
POSSIBLE FOR THE KDIK...KBIS AND KJMS TAF SITES THURSDAY AFTERNOON
AND EVENING.
&&
.HYDROLOGY...
ISSUED AT 405 PM CDT WED MAY 29 2013
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP LATE THIS
AFTERNOON AND TONIGHT...AND MOVE FROM SOUTH TO NORTH ACROSS
WESTERN AND CENTRAL NORTH DAKOTA THROUGH THURSDAY AFTERNOON.
THE POTENTIAL FOR HEAVY RAIN EXISTS ACROSS THE WEST AND CENTRAL...
ESPECIALLY LATE TONIGHT THROUGH THURSDAY. WIDESPREAD RAINFALL
AMOUNTS OF THREE QUARTERS OF AN INCH...TO TWO INCHES ARE FORECAST
THOUGH THIS PERIOD. HOWEVER...THE LATEST GUIDANCE CONTINUES TO
SUGGEST A LESS LIKELY SCENARIO FOR AMOUNTS GREATER THAN 1.5 INCHES
OVER MUCH OF THE CENTRAL. THE MOST LIKELY AREAS FOR THE HIGHEST
AMOUNTS APPEAR TO BE IN THE FAR NORTH AND FAR WEST...WITH THE
HIGHEST AMOUNTS IN EASTERN MONTANA AND SOUTHERN CANADA.
STREAM AND RIVER RISES ARE POSSIBLE BY THE END OF THE WEEK INTO
THIS COMING WEEKEND. AN ADDITIONAL ONE QUARTER TO ONE HALF INCH
WILL BE POSSIBLE FRIDAY AND FRIDAY NIGHT. CHANCES FOR RAIN
DECREASE SATURDAY INTO SATURDAY NIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JNS
SHORT TERM...TWH
LONG TERM...NH
AVIATION...JNS
HYDROLOGY...TWH
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
442 AM EDT THU MAY 30 2013
.SYNOPSIS...
HIGH PRESSURE CENTERED OVER THE ATLANTIC WILL KEEP US DRY WITH
TEMPERATURES SLIGHTLY ABOVE AVERAGE THROUGH THE END OF THE WEEK. THE
HIGH MOVES OFF THE ATLANTIC COAST OVER THE WEEKEND...AND A COLD
FRONT APPROACHES BY EARLY NEXT WEEK...RETURNING US TO AN UNSETTLED
PATTERN.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 440 AM EDT THURSDAY...MVFR CIGS ARE FILLING IN QUICKLY OVER NE
GA AND WE APPEAR TO BE ON TRACK FOR A STRATUS DECK TO INVADE THE
FORECAST AREA FROM THE SOUTHWEST OVER THE NEXT FEW HOURS. I DID
TWEAK SKY COVER TO ACCOUNT FOR CURRENT TRENDS...HOWEVER.
AS OF 300 AM EDT THURSDAY...MVFR LEVEL STRATUS IS EXPANDING ACROSS
SOUTHERN AND CENTRAL GA EARLY THIS THURSDAY MORNING. THE SREF SHOWS
A HIGH PROBABILITY THAT IT WILL CONTINUE TO EXPAND NORTH AND
NORTHEAST...EVENTUALLY SPREADING ACROSS NE GA...THE WRN UPSTATE AND
THE SRN NC MTNS. I/VE CARRIED MOSTLY CLOUDY SKIES EARLY IN THE DAY
TO ACCOUNT FOR THIS...BUT THE CLOUD LAYER SHOULD BE SHALLOW AND
SHOULD MIX INTO A CU FIELD FAIRLY QUICKLY BY LATE MORNING. OTHERWISE
IT WILL BE DRY ACROSS THE ENTIRE FORECAST AREA TODAY WITH MAX TEMPS
RUNNING ABOUT A CATEGORY ABOVE NORMAL.
WE WILL PROBABLY SEE STRATUS DEVELOP AGAIN TONIGHT. IN FACT...WITH
HIGHER BNDRY LAYER RH/S AND A STRONGER WIND FIELD...IT IS LIKELY TO
COVER MOST OF THE FORECAST AREA. STILL...IT/S NOT A GIVEN THAT THIS
WILL HAPPEN AND MY SKY COVER IS RATHER LOW...ESPECIALLY ACROSS WRN
NC.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 245 AM THURSDAY...UPPER RIDGE WILL BEGIN TO BREAK DOWN AND
SHIFT EAST FURTHER OFF THE ATLANTIC COAST DURING THE SHORT
TERM...BUT OVERALL WILL CONTINUE TO INFLUENCE OUR SENSIBLE WX. LLVL
FLOW WILL REMAIN LIGHT GENERALLY OUT OF THE S/SE OFF THE ATLANTIC.
MODELS IN BETTER AGREEMENT ON MORNING STRATUS DEVELOPING AND BEING A
LITTLE BIT MORE WIDESPREAD FRIDAY MORNING...BUT SHUD SCATTER OUT BY
MIDDAY. FCST SNDGS SHOW WEAK CAPE WITH INHIBITION FRI AFTN...SO
GOING WITH A DRY FCST.
ON SATURDAY...ONCE AGAIN...GUIDANCE INDICATING MORNING STRATUS
DEVELOPMENT...WITH INCREASE IN SOME MID-UPR MOISTURE AS WELL.
OVERALL...STILL LOOKS LIKE ANOTHER DRY DAY...ALTHO WILL KEEP A SLGT
CHC POP FOR THE NC MTNS...THANKS TO SOME INCREASED MOISTURE IN A
VEERING SWLY LLVL FLOW. HIGHS BOTH DAYS WILL BE SIMILAR TO LAST
COUPLE OF DAYS...ABOUT A CATEGORY OR TWO ABOVE NORMAL...WITH NEAR OR
SLIGHTLY ABOVE NORMAL OVERNIGHT LOWS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...UNSETTLED WEATHER LOOKS TO RETURN THE CWFA
FOR SUNDAY INTO EARLY NEXT WEEK.
A COLD FRONT WILL APPROACH THE AREA FROM THE WEST ON SUNDAY...WITH A
PLUME OF DEEP RH AND HEIGHT FALLS ENTERING THE NC MTNS BY PEAK
HEATING. SO A SOLID CHC TO LOW-END LIKELY POPS FOR SUNDAY LOOKS
GOOD. CONVECTION MAY LINGER INTO THE NIGHT IN THE MOIST AIR MASS
WITH SOME UPR SUPPORT. THE FRONT IS PROGGED TO SETTLE ROUGHLY ALONG
THE BLUE RIDGE ON MONDAY...WITH PLENTY OF AFTN INSTBY ONCE AGAIN.
EXPECTING SCATTERED TO NUMEROUS SHWRS AND TSTMS TO
DEVELOP...POSSIBLY MOST FAVORED IN THE PIEDMONT ON WARM SIDE OF THE
FRONT. HIGHS WILL BE NEAR NORMAL BOTH DAYS...WITH SLIGHTLY ABOVE
NORMAL OVERNIGHT TEMPS.
THE FORECAST FOR TUESDAY AND WEDNESDAY WERE UNCHANGED...AS LATEST
MODEL TRENDS AND THE 00Z WPC GRIDS ARE IN LINE WITH EARLIER
THINKING. STILL EXPECTING THE FRONT TO SAG SE THRU THE CAROLINAS ON
TUESDAY...WITH A LINGERING CHC POP MAINLY SE OF I-85. THEN JUST A
SLGT CHC POP FOR MOST OF THE AREA ON WEDNESDAY...AS CANADIAN HIGH
PRES BUILDS IN ACRS THE GREAT LAKES TO THE SOUTHEAST STATES. TEMPS
WILL BE NEAR NORMAL.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
AT KCLT...MODEL GUIDANCE AND PERSISTANCE FROM LAST NIGHT IMPLIES
THAT STRATUS WILL DEVELOP DOWN ACROSS THE MIDLANDS AND CLOSER TO THE
MOUNTAINS TOWARD MORNING. IT/S A TOUGH CALL...BUT KCLT MAY NOT
ACTUALLY SEE A CIG LATER TONIGHT. THEREFORE I/VE BACKED OFF THE BKN
CIG AND GONE SCT010 STARTING AT 10 UTC. THE NAM BUFKIT SOUNDINGS
APPEAR TO BE CAPPED AND NOT SUPPORTIVE OF A CU FIELD IN THE AFTN. I
THINK THAT/S A HAIR OVERDONE AND I DO KEEP FEW040 AROUND DURING THE
AFTN. WINDS WILL BE LIGHT OUT OF THE S TO SSW THROUGH THE DAY.
ELSEWHERE...PER THE SREF PROBS OF CIGS LOWER THAN 3KFT AND THE AREA
OF HIGHEST LLVL RH ON THE RUC AND PERSISTANCE WITH LAST NIGHT...WE
SHOULD SEE STRATUS DEVELOP OVER NORTH CENTRAL GA STARTING IN AN HOUR
OR TWO. IT SHOULD EXPAND NORTHEAST WITH TIME...AND SHOULD EVENTUALLY
WORK ACROSS THE UPSTATE TAF SITES. EXACTLY WHEN THIS HAPPENS ISN/T
AN EASY CALL. FOR NOW I HAVE MVFR CIGS DEVELOPING AT 10 UTC AT KAND
AND NOT TIL 12 UTC AT KGSP. HOPEFULLY THAT WILL BE CLOSE. I/M LESS
CONFIDENT OF STRATUS AT KAVL OR KHKY AND I HAVEN/T CARRIED ANYTHING
AT THOSE SITES. CIGS WILL GRADUALLY LIFT AND MIX OUT DURING THE
COURSE OF THE MORNING. OTHERWISE WINDS WILL BE OUT OF THE S TO SSW
AGAIN TODAY AT SPEEDS UNDER 10 KTS.
OUTLOOK...GENERALLY FAIR CONDITIONS ARE EXPECTED THROUGH SATURDAY.
HOWEVER...RESTRICTIONS FROM MORNING STRATUS...AND POSSIBLY
FOG...WILL CONTINUE EACH MORNING THRU SUNDAY. CHANCES FOR MAINLY
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL INCREASE
SIGNIFICANTLY BY SUNDAY AFTERNOON...AS A COLD FRONT APPROACHES FROM
THE TN VALLEY.
CONFIDENCE TABLE...
08-14Z 14-20Z 20-02Z 02-08Z
KCLT HIGH 93% HIGH 93% HIGH 100% HIGH 100%
KGSP HIGH 87% HIGH 80% HIGH 100% HIGH 100%
KAVL HIGH 98% HIGH 100% HIGH 100% HIGH 95%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 90%
KGMU HIGH 87% HIGH 80% HIGH 100% HIGH 100%
KAND HIGH 81% HIGH 81% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...LEV
NEAR TERM...MCAVOY
SHORT TERM...ARK
LONG TERM...ARK
AVIATION...MCAVOY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
318 AM EDT THU MAY 30 2013
.SYNOPSIS...
HIGH PRESSURE CENTERED OVER THE ATLANTIC WILL KEEP US DRY WITH
TEMPERATURES SLIGHTLY ABOVE AVERAGE THROUGH THE END OF THE WEEK. THE
HIGH MOVES OFF THE ATLANTIC COAST OVER THE WEEKEND...AND A COLD
FRONT APPROACHES BY EARLY NEXT WEEK...RETURNING US TO AN UNSETTLED
PATTERN.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM EDT THURSDAY...MVFR LEVEL STRATUS IS EXPANDING ACROSS
SOUTHERN AND CENTRAL GA EARLY THIS THURSDAY MORNING. THE SREF SHOWS
A HIGH PROBABILITY THAT IT WILL CONTINUE TO EXPAND NORTH AND
NORTHEAST...EVENTUALLY SPREADING ACROSS NE GA...THE WRN UPSTATE AND
THE SRN NC MTNS. I/VE CARRIED MOSTLY CLOUDY SKIES EARLY IN THE DAY
TO ACCOUNT FOR THIS...BUT THE CLOUD LAYER SHOULD BE SHALLOW AND
SHOULD MIX INTO A CU FIELD FAIRLY QUICKLY BY LATE MORNING. OTHERWISE
IT WILL BE DRY ACROSS THE ENTIRE FORECAST AREA TODAY WITH MAX TEMPS
RUNNING ABOUT A CATEGORY ABOVE NORMAL.
WE WILL PROBABLY SEE STRATUS DEVELOP AGAIN TONIGHT. IN FACT...WITH
HIGHER BNDRY LAYER RH/S AND A STRONGER WIND FIELD...IT IS LIKELY TO
COVER MOST OF THE FORECAST AREA. STILL...IT/S NOT A GIVEN THAT THIS
WILL HAPPEN AND MY SKY COVER IS RATHER LOW...ESPECIALLY ACROSS WRN
NC.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 245 AM THURSDAY...UPPER RIDGE WILL BEGIN TO BREAK DOWN AND
SHIFT EAST FURTHER OFF THE ATLANTIC COAST DURING THE SHORT
TERM...BUT OVERALL WILL CONTINUE TO INFLUENCE OUR SENSIBLE WX. LLVL
FLOW WILL REMAIN LIGHT GENERALLY OUT OF THE S/SE OFF THE ATLANTIC.
MODELS IN BETTER AGREEMENT ON MORNING STRATUS DEVELOPING AND BEING A
LITTLE BIT MORE WIDESPREAD FRIDAY MORNING...BUT SHUD SCATTER OUT BY
MIDDAY. FCST SNDGS SHOW WEAK CAPE WITH INHIBITION FRI AFTN...SO
GOING WITH A DRY FCST.
ON SATURDAY...ONCE AGAIN...GUIDANCE INDICATING MORNING STRATUS
DEVELOPMENT...WITH INCREASE IN SOME MID-UPR MOISTURE AS WELL.
OVERALL...STILL LOOKS LIKE ANOTHER DRY DAY...ALTHO WILL KEEP A SLGT
CHC POP FOR THE NC MTNS...THANKS TO SOME INCREASED MOISTURE IN A
VEERING SWLY LLVL FLOW. HIGHS BOTH DAYS WILL BE SIMILAR TO LAST
COUPLE OF DAYS...ABOUT A CATEGORY OR TWO ABOVE NORMAL...WITH NEAR OR
SLIGHTLY ABOVE NORMAL OVERNIGHT LOWS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...UNSETTLED WEATHER LOOKS TO RETURN THE CWFA
FOR SUNDAY INTO EARLY NEXT WEEK.
A COLD FRONT WILL APPROACH THE AREA FROM THE WEST ON SUNDAY...WITH A
PLUME OF DEEP RH AND HEIGHT FALLS ENTERING THE NC MTNS BY PEAK
HEATING. SO A SOLID CHC TO LOW-END LIKELY POPS FOR SUNDAY LOOKS
GOOD. CONVECTION MAY LINGER INTO THE NIGHT IN THE MOIST AIR MASS
WITH SOME UPR SUPPORT. THE FRONT IS PROGGED TO SETTLE ROUGHLY ALONG
THE BLUE RIDGE ON MONDAY...WITH PLENTY OF AFTN INSTBY ONCE AGAIN.
EXPECTING SCATTERED TO NUMEROUS SHWRS AND TSTMS TO
DEVELOP...POSSIBLY MOST FAVORED IN THE PIEDMONT ON WARM SIDE OF THE
FRONT. HIGHS WILL BE NEAR NORMAL BOTH DAYS...WITH SLIGHTLY ABOVE
NORMAL OVERNIGHT TEMPS.
THE FORECAST FOR TUESDAY AND WEDNESDAY WERE UNCHANGED...AS LATEST
MODEL TRENDS AND THE 00Z WPC GRIDS ARE IN LINE WITH EARLIER
THINKING. STILL EXPECTING THE FRONT TO SAG SE THRU THE CAROLINAS ON
TUESDAY...WITH A LINGERING CHC POP MAINLY SE OF I-85. THEN JUST A
SLGT CHC POP FOR MOST OF THE AREA ON WEDNESDAY...AS CANADIAN HIGH
PRES BUILDS IN ACRS THE GREAT LAKES TO THE SOUTHEAST STATES. TEMPS
WILL BE NEAR NORMAL.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
AT KCLT...MODEL GUIDANCE AND PERSISTANCE FROM LAST NIGHT IMPLIES
THAT STRATUS WILL DEVELOP DOWN ACROSS THE MIDLANDS AND CLOSER TO THE
MOUNTAINS TOWARD MORNING. IT/S A TOUGH CALL...BUT KCLT MAY NOT
ACTUALLY SEE A CIG LATER TONIGHT. THEREFORE I/VE BACKED OFF THE BKN
CIG AND GONE SCT010 STARTING AT 10 UTC. THE NAM BUFKIT SOUNDINGS
APPEAR TO BE CAPPED AND NOT SUPPORTIVE OF A CU FIELD IN THE AFTN. I
THINK THAT/S A HAIR OVERDONE AND I DO KEEP FEW040 AROUND DURING THE
AFTN. WINDS WILL BE LIGHT OUT OF THE S TO SSW THROUGH THE DAY.
ELSEWHERE...PER THE SREF PROBS OF CIGS LOWER THAN 3KFT AND THE AREA
OF HIGHEST LLVL RH ON THE RUC AND PERSISTANCE WITH LAST NIGHT...WE
SHOULD SEE STRATUS DEVELOP OVER NORTH CENTRAL GA STARTING IN AN HOUR
OR TWO. IT SHOULD EXPAND NORTHEAST WITH TIME...AND SHOULD EVENTUALLY
WORK ACROSS THE UPSTATE TAF SITES. EXACTLY WHEN THIS HAPPENS ISN/T
AN EASY CALL. FOR NOW I HAVE MVFR CIGS DEVELOPING AT 10 UTC AT KAND
AND NOT TIL 12 UTC AT KGSP. HOPEFULLY THAT WILL BE CLOSE. I/M LESS
CONFIDENT OF STRATUS AT KAVL OR KHKY AND I HAVEN/T CARRIED ANYTHING
AT THOSE SITES. CIGS WILL GRADUALLY LIFT AND MIX OUT DURING THE
COURSE OF THE MORNING. OTHERWISE WINDS WILL BE OUT OF THE S TO SSW
AGAIN TODAY AT SPEEDS UNDER 10 KTS.
OUTLOOK...GENERALLY FAIR CONDITIONS ARE EXPECTED THROUGH SATURDAY.
HOWEVER...RESTRICTIONS FROM MORNING STRATUS...AND POSSIBLY
FOG...WILL CONTINUE EACH MORNING THRU SUNDAY. CHANCES FOR MAINLY
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL INCREASE
SIGNIFICANTLY BY SUNDAY AFTERNOON...AS A COLD FRONT APPROACHES FROM
THE TN VALLEY.
CONFIDENCE TABLE...
07-13Z 13-19Z 19-01Z 01-07Z
KCLT HIGH 100% HIGH 85% HIGH 100% HIGH 100%
KGSP HIGH 96% MED 72% HIGH 100% HIGH 100%
KAVL HIGH 96% HIGH 100% HIGH 100% HIGH 97%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 94%
KGMU HIGH 96% MED 72% HIGH 100% HIGH 100%
KAND HIGH 89% MED 76% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...LEV
NEAR TERM...MCAVOY
SHORT TERM...ARK
LONG TERM...ARK
AVIATION...MCAVOY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
131 AM EDT THU MAY 30 2013
.SYNOPSIS...
HIGH PRESSURE CENTERED OVER THE ATLANTIC WILL KEEP US DRY WITH
TEMPERATURES SLIGHTLY ABOVE AVERAGE THROUGH THE END OF THE WEEK. THE
HIGH MOVES OFF THE ATLANTIC COAST OVER THE WEEKEND... AND A COLD
FRONT APPROACHES BY EARLY NEXT WEEK... RETURNING US TO AN UNSETTLED
PATTERN.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 0130 AM EDT THURSDAY...SCT TO BKN STRATO-CU CONTINUE TO
DEVELOP ALONG THE BLUE RIDGE. UPPED SKY COVER TO ACCOUNT FOR THAT.
BASED ON THE SREF...RUC AND PERSISTENCE WITH LAST NIGHT I/VE UPPED
SKY COVER TOWARD MORNING AND BROUGHT A STRATUS DECK ACROSS NE
GA...THE NORTHERN AND WRN UPSTATE AND THE SRN NC MTNS...SOUTH OF
ASHEVILLE.
AS OF MID EVENING...FORECAST LOOKS LIKE IT IS IN GOOD SHAPE. NO
CHANGES PLANNED.
REMAINDER OF PREVIOUS DISCUSSION...
CLOUDS SHUD DIMINISH THIS EVENING WITH LOSS OF HEATING. EXPECT
ANOTHER ROUND OF LOW CLOUDS TO DEVELOP ACROSS THE SRN AND WRN CWFA
NEAR DAYBREAK GIVEN THE CONTINUED MOIST SLY LOW LEVEL FLOW AND
SUBSIDENCE INVERSION. EXPECT MOST OF THE NC PIEDMONT TO ONLY SEE SCT
CLOUDS BY MORNING...BUT THE CLOUDY SKIES COULD CREEP FARTHER NORTH.
THE CLOUDS SHUD SLOWLY LIFT AND SCATTER OUT THRU THE MORNING THU
WITH MOSTLY SUNNY SKIES EXPECTED FOR AFTERNOON. WITH RIDGING SFC AND
ALOFT...AND ASSOCIATED SUBSIDENCE INVERSION... REMAINING IN PLACE
ACROSS THE AREA THU...DO NOT EXPECT ANY DEEP CONVECTION TO DEVELOP
DURING THE AFTERNOON...EVEN OVER THE MTNS. LOWS TONIGHT SHUD BE NEAR
TO SLIGHTLY ABOVE NORMAL. HIGHS THU SHUD RISE TO AS MUCH AS 5
DEGREES ABOVE NORMAL.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
AS OF 205 PM WEDNESDAY...UPPER RIDGE WILL REMAIN CENTERED/SITUATED
IN THE VICINITY OF THE VA COAST WITH ONLY A SLOW TRANSITION TO THE
EAST THROUGH SAT. AT THE SURFACE...THE BURMUDA HIGH WILL REMAIN
RIDGED WESTWARD INTO THE SE U.S.. THEREFORE...GENERALLY DRY AND VERY
WARM WEATHER WILL CONTINUE IN THE SHORT TERM. MODELS ARE GENERALLY
LACKING IN QPF RESPONSE THU NIGHT THRU SAT. THIS MAKES SENSE IN
THAT FCST SNDGS CONTINUE TO FEATURE A SUBSIDENCE INVERSION. THE
EXCEPTION TO THE GENERAL LACK OF CONVECTION MAY BE FRI EVENING OVER
THE MOUNTAINS AS MODEL TIME HEIGHTS SHOW LOW LEVEL MOISTURE
INCREASING DUE TO THE SE FLOW OFF THE ATLANTIC WHICH MAY ALLOW
PARCELS TO OVERCOME THE CAP IN UPSLOPE AREAS. HENCE...HAVE SOME
ISOLATED/WIDELY SCT POPS FRI NIGHT IN THE MOUNTAINS TO ACCOUNT FOR
THIS. A FEW ISOLD CELLS CANNOT BE RULED OUT IN THE MTNS AGAIN SAT
AFTERNOON.. HIGHS WILL CONTINUE TO BE A CATEORY OR TWO ABOVE NORMAL
BOTH DAYS. OVERNIGHT LOWS WILL BE QUITE MILD AS THE MOIST/PERSISTENT
SELY FLOW OFF THE ATLANTIC IS LIKELY TO PRODUCE SOME MORNING STRATUS
BOTH FRI AND SAT 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 NIGHT THROUGH WEDNESDAY/...
AS OF 200 PM WEDNESDAY...LOOKS LIKE AN ACTIVE PATTERN WILL BE
IN PLAY OVER THE EXT RANGE. THE LATEST OP MODELS AGREE DECENTLY WITH
THE ULVL FLOW AND UPSTREAM TROF CONFIG BEGINNING THE PERIOD AND WITH
THE GENERAL PROPAGATION AND STRENGTH OF THE SYNOPTIC WAVE EASTWARD.
THERE ARE ENOUGH DIFFERENCES IN THE DETAILS HOWEVER TO HAVE MODERATE
OR A BIT LOWER CONFIDENCE IN THE SENSIBLE WX OVER THE PERIOD. THE
12Z GFS IS A SLOWER OUTLIER AND THE GEFS MEAN GIVES SUPPORT TO THE
QUICKER ECMWF...THUS A BLEND OF THE OP MODELS AND WPC GUIDANCE WAS
USED FOR OVERALL TIMING AND THE WEAKENING TROF.
THE PERIOD BEGINS WITH MOIST ATL FLOW CONTINUING ACROSS THE REGION
AND A FEW UPSLOPE -SHRA/TSTMS SHOULD BE WANING THROUGH SAT NIGHT. AS
THE UPPER TROF IMPINGES...ULVL DIV WILL INCREASE AND AIDE IN THUNDER
ACTIVITY SUN AFTERNOON. NOT MUCH OF A DISTINCT SFC CONVERGENCE ZONE
IS NOTED...SO WILL EXPECT MOST OF THE ACTIVITY ACROSS THE NC MTNS
WHERE LIKELY POPS HAVE BEEN INTRODUCED. SOUNDINGS SHOW A DEEP
CONVECTIVE POTENTIAL WITH LOW END SBCAPE DEVELOPING AS THE WEAKENING
ULVL VORT WAVE CROSSES OVERHEAD. SO...EXPECT PRETTY GOOD COVERAGE IN
THE MTNS...WITH ISOL/SCT STORMS DEVELOPING TO THE EAST THROUGH THE
AFTERNOON....THEN LIKELY COVERAGE MOST LOCALES AS THE WAVE MOVES
EAST OVERNIGHT. THERE REMAINS A FAIR AMOUNT OF UNCERTAINTY MON WRT
TO THE FRONTAL PLACEMENT...AND WILL COUNT THE FRONT JUST MOVING INTO
THE MTNS BY MID DAY. SO...ANOTHER DAY OF GOOD HEATING AND
INSTABILITY WILL GENERATE TSTMS. THE GFS SLOWS THE FRONT DOWN AS IT
LOSES MUCH ULVL SUPPORT AND KEEPS THINGS ACTIVE MON NIGHT INTO
TUE...WHILE THE ECMWF AND THE WPC HAVE THE FRONT NEAR THE ATL COAST
BY 12Z TUE. WITH THIS MUCH UNCERTAINTY...HAVE ALIGNED CHANCE POPS TO
FAVOR THE ERN ZONES LATE MON THROUGH TUE. THERE IS GOOD AGREEMENT
WITH A MOIST WEDGE DEVELOPING TUE NIGHT AND PERSISTING THROUGH TH
PERIOD. THIS WOULD KEEP MAX TEMPS A CAT OR SO BELOW NORMAL WED AND
POSSIBLY THU. MAX TEMPS SUN THROUGH TUE SHOULD BE A FEW DEGREES ABOVE
NORMAL WITH WARM SECTOR FLOW REMAINING OVER THE REGION. WITH ALL THE
NOCTURNAL CLOUDINESS EXPECTED...MINS SHOULD ALSO BE A COUPLE DEGREES
ABOVE NORMAL THROUGH TUE MORNING BEFORE THE WEDGE BUILDS IN.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AT KCLT...MODEL GUIDANCE AND PERSISTANCE FROM LAST NIGHT IMPLIES
THAT STRATUS WILL DEVELOP DOWN ACROSS THE MIDLANDS AND CLOSER TO THE
MOUNTAINS TOWARD MORNING. IT/S A TOUGH CALL...BUT KCLT MAY NOT
ACTUALLY SEE A CIG LATER TONIGHT. THEREFORE I/VE BACKED OFF THE BKN
CIG AND GONE SCT010 STARTING AT 10 UTC. THE NAM BUFKIT SOUNDINGS
APPEAR TO BE CAPPED AND NOT SUPPORTIVE OF A CU FIELD IN THE AFTN. I
THINK THAT/S A HAIR OVERDONE AND I DO KEEP FEW040 AROUND DURING THE
AFTN. WINDS WILL BE LIGHT OUT OF THE S TO SSW THROUGH THE DAY.
ELSEWHERE...PER THE SREF PROBS OF CIGS LOWER THAN 3KFT AND THE AREA
OF HIGHEST LLVL RH ON THE RUC AND PERSISTANCE WITH LAST NIGHT...WE
SHOULD SEE STRATUS DEVELOP OVER NORTH CENTRAL GA STARTING IN AN HOUR
OR TWO. IT SHOULD EXPAND NORTHEAST WITH TIME...AND SHOULD EVENTUALLY
WORK ACROSS THE UPSTATE TAF SITES. EXACTLY WHEN THIS HAPPENS ISN/T
AN EASY CALL. FOR NOW I HAVE MVFR CIGS DEVELOPING AT 10 UTC AT KAND
AND NOT TIL 12 UTC AT KGSP. HOPEFULLY THAT WILL BE CLOSE. I/M LESS
CONFIDENT OF STRATUS AT KAVL OR KHKY AND I HAVEN/T CARRIED ANYTHING
AT THOSE SITES. CIGS WILL GRADUALLY LIFT AND MIX OUT DURING THE
COURSE OF THE MORNING. OTHERWISE WINDS WILL BE OUT OF THE S TO SSW
AGAIN TODAY AT SPEEDS UNDER 10 KTS.
OUTLOOK...GENERALLY FAIR CONDITIONS ARE EXPECTED THROUGH SATURDAY.
HOWEVER...RESTRICTIONS FROM MORNING STRATUS...AND POSSIBLY
FOG...WILL CONTINUE EACH MORNING THRU SUNDAY. CHANCES FOR MAINLY
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL INCREASE
SIGNIFICANTLY BY SUNDAY AFTERNOON...AS A COLD FRONT APPROACHES FROM
THE TN VALLEY.
CONFIDENCE TABLE...
05-11Z 11-17Z 17-23Z 23-05Z
KCLT HIGH 100% HIGH 85% HIGH 100% HIGH 100%
KGSP HIGH 100% MED 73% HIGH 100% HIGH 100%
KAVL HIGH 97% HIGH 94% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% MED 73% HIGH 100% HIGH 100%
KAND HIGH 100% MED 72% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...LEV
NEAR TERM...MCAVOY
SHORT TERM...LG
LONG TERM...SBK
AVIATION...MCAVOY
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1237 AM CDT THU MAY 30 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 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1237 AM CDT THU MAY 30 2013
WITH LOWER LEVELS HAVING DRIED OUT IN INCREASING SOUTHERLY
FLOW...VFR IS NOW EXPECTED TO BE GENERAL EXCEPT FOR A PERIOD OF
CEILINGS 1-3K FEET SOUTH AND EAST OF FSD 09Z-15Z. OTHERWISE A FEW
AREAS OF THESE MVFR CONDITIONS WILL BE POSSIBLE IN SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS THROUGH 15Z. 15Z-31/01Z VFR
EXCEPT LOCAL AND BRIEF CEILINGS 2-3K FEET AND VISIBILITIES 3-5SM
IN ISOLATED TSRA EAST AND SOUTH OF FSD. AFTER 01Z VFR OVER AREA.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...FLASH FLOOD WATCH UNTIL 7 AM CDT THIS MORNING FOR IAZ002-003-
012>014-020>022-031-032.
NE...FLASH FLOOD WATCH UNTIL 7 AM CDT THIS MORNING FOR NEZ014.
&&
$$
SHORT TERM...08
LONG TERM...CHAPMAN
AVIATION...
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
333 AM CDT THU MAY 30 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 333 AM CDT THU MAY 30 2013
CURRENTLY AS OF 0830Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED UPPER TROUGHING FROM THE NORTHEAST PACIFIC INTO THE NORTHERN
ROCKIES WITH AN UPPER LOW IN NORTHEAST WYOMING...WHILE DOWNSTREAM
RIDGING WAS PRESENT ACROSS THE EASTERN U.S.. ALSO TO NOTE ON WATER
VAPOR IS A FAIRLY POTENT SHORTWAVE OVER THE TEXAS AND OKLAHOMA
PANHANDLES IN THE BASE OF THIS TROUGHING. NEARLY UNIDIRECTIONAL
SOUTH TO SOUTHWEST FLOW EXISTED BETWEEN THE TROUGHING AND RIDGING...
WITH SOME VERY STRONG WINDS AT 850MB. VWP AND PROFILER DATA SHOWED
SPEEDS OF 50-65 KT FROM CENTRAL OKLAHOMA INTO SOUTHERN MINNESOTA.
THESE WINDS WERE TRANSPORTING COPIOUS AMOUNTS OF MOISTURE
NORTHWARD...NOTED BY PRECIPITABLE WATER VALUES OF 1.5-1.75 INCHES OR
150-180 PERCENT OF NORMAL. NUMEROUS SHORTWAVES...SOME CONVECTIVELY
INDUCED...RIDING THROUGH THE MID LEVEL FLOW HAS BEEN INTERACTING
WITH THE MORE SUMMER-LIKE AIRMASS TO CONTINUE TO PRODUCE SCATTERED
CLUSTERS OF SHOWERS AND THUNDERSTORMS. MUCH OF THE FORECAST AREA
LIES IN THE WARM SECTOR OF A LOW PRESSURE SYSTEM BACK IN THE
DAKOTAS. MAIN WARM FRONT HAS LIFTED INTO NORTHERN WISCONSIN WHILE
THE COLD FRONT IS WELL BACK TO THE WEST IN CENTRAL SOUTH DAKOTA.
MODELS ARE IN GOOD AGREEMENT ON THE SYNOPTICS THROUGH TONIGHT...
INDICATING THAT THE UPPER TROUGHING FROM WYOMING INTO THE TEXAS
PANHANDLE WILL SHIFT EAST NORTHEAST INTO THE FORECAST AREA BY 06Z
TONIGHT. THERE ARE SOME DECENT 500MB HEIGHT FALLS BETWEEN 18Z-06Z
OVER THE FORECAST AREA...ON THE ORDER OF 60-90 METERS. THE DPVA FROM
THE APPROACH OF THIS UPPER TROUGH...AS WELL AS VARIOUS SHORTWAVES
AND CONVECTIVELY INDUCED SHORTWAVES AHEAD OF IT...SUGGESTS PLENTY OF
FORCING FOR CONVECTION. MODELS HAVE SHOWN THIS FOR MANY DAYS AS
WELL. THIS FORCING MAY MAKE IT HARD TO BUILD A LOT OF INSTABILITY...
COMPARED TO YESTERDAY WHERE WE HAD PLENTY OF SUNSHINE BEFORE
CONVECTION ERUPTED. RAP/NAM/GFS SOUNDINGS ALL SUGGEST ANY 0-1 MLCIN
FROM NOCTURNAL INFLUENCES BEING NEARLY COMPLETELY GONE BY 15Z.
THEREFORE IT IS CONCEIVABLE FOR CONVECTION TO FIRE SHORTLY
THEREAFTER WHEN 0-1 MLCAPE IS ONLY AT 800-1500 J/KG. HRRR/RAP MODELS
SHOW CONVECTION FIRING IN THAT 15-16Z WINDOW...IN AGREEMENT WITH THE
ABOVE ANALYSIS. THE CONVECTION MAY STABILIZE THINGS BRIEFLY...BUT
PERSISTENT HEATING THROUGH THE DAY COMBINED WITH SOUTHERLY WARM
ADVECTION OF INSTABILITY SHOULD PROVIDE FUEL TO CONTINUE PERIODS OF
CONVECTION THROUGH THE DAY AND INTO THE EVENING. PASSAGE OF THE
UPPER TROUGH AND NOCTURNAL COOLING SHOULD ALLOW CONVECTION TO
SUBSIDE AFTER MIDNIGHT.
REGARDING SEVERE POTENTIAL...THE LIMITATION OF BUILDING A LOT OF
CAPE IS A HINDRANCE. 0-6KM SHEAR FROM THE 30.00Z NAM/GFS IS
GENERALLY PROGGED AT 25-30 KT THROUGH THE DAY...FAVORING FOR MORE OF
A MULTI-CELL SITUATION. WITH INSTABILITY STRUGGLING...NOT THINKING
MUCH IN THE WAY FOR SEVERE HAIL. BULK OF THE AFOREMENTIONED 0-6KM
SHEAR IS IN THE 0-3KM LAYER...AND COMBINED WITH 850MB WINDS PROGGED
IN THE AFTERNOON AND EVENING OF 45-50 KT DOES BRING UP A CONCERN FOR
THE STORMS TO PRODUCE STRONG TO DAMAGING WIND GUSTS. 0-1KM SHEAR IS
QUITE HIGH AS WELL FOR THE AFTERNOON AND EVENING...SIMILAR TO 0-3KM
OF 25-30KT...SO WE MAY WANT TO WATCH FOR POSSIBLE TORNADOES TOO.
THIS WOULD BE ESPECIALLY TRUE ALONG ANY CONVECTIVE OUTFLOW BOUNDARY
AND/OR IF WE CAN GET MORE DAYTIME HEATING THAN EXPECTED.
ON THE FLOODING FRONT...MORE INFORMATION CAN BE FOUND IN THE
HYDROLOGY SECTION BELOW. BRIEFLY...THE PATTERN TODAY INTO THIS
EVENING IS VERY FAVORABLE FOR STORMS TO TRAIN ACROSS THE SAME AREAS
AS THEY MARCH SOUTH TO NORTH. WITH PRECIPITABLE WATER VALUES STAYING
UP IN THE 1.5-1.75 INCH RANGE ANY STORM CAN PRODUCE HEAVY RAIN. WITH
GROUNDS ALREADY SATURATED...FLASH FLOODING IS CERTAINLY POSSIBLE...
ESPECIALLY SOUTH OF I-90 WHICH WAS REALLY IMPACTED FROM YESTERDAY
INTO LAST NIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 333 AM CDT THU MAY 30 2013
LOW PRESSURE OVER THE EASTERN DAKOTAS PUSHES SOUTHEAST LATE FRIDAY
MORNING INTO FRIDAY AFTERNOON DRIVING THE FRONT ACROSS THE FORECAST
AREA. DEPENDING ON THE TIMING OF THIS FRONT...SEVERE WEATHER POSSIBLE
ON FRIDAY. FORECAST MODELS ARE IN REASONABLE AGREEMENT...SHOWING
0-3 KM MUCAPE VALUES CLIMBING TO 2000 TO 3000 J/KG. SHEAR IS ALSO
RAMPING UP LATE FRIDAY MORNING INTO FRIDAY AFTERNOON WITH 0-6 KM
BULK SHEAR INCREASING TO 45 TO 55 KTS. THE HIGHEST INSTABILITY
APPEARS TO BE OVER FAR NORTHEAST IOWA AND INTO EXTREME SOUTHWEST
WISCONSIN. WILL HAVE TO KEEP A VERY CLOSE WATCH ON THIS OVER THE
NEXT FEW MODEL RUNS. AT THIS TIME...LARGE HAIL AND DAMAGING WINDS
APPEAR TO BE THE MAIN HAZARDS FROM THESE STORMS. BUT AGAIN...THE
SEVERE THREAT AREA WILL DEPEND ON WHERE THE BOUNDARY IS LOCATED
LATE FRIDAY MORNING INTO FRIDAY AFTERNOON AND HOW MUCH SURFACE
HEATING IS REALIZED. A DRY SLOT PUSHES INTO THE FORECAST AREA LATE
FRIDAY NIGHT AS THE LOW PUSHES EAST INTO THE WESTERN GREAT LAKES.
THERE SHOULD BE A DRY PERIOD AS THE LOW MOVES IN...BUT THEN
SHOWERS AND ISOLATED THUNDERSTORMS WILL DEVELOP ON SATURDAY AS THE
LOW SLIDES ACROSS THE REGION. AN UNSEASONABLY COOL AIRMASS MOVES
INTO REGION ON SUNDAY. 850 MB TEMPERATURES FALL TO 0 C OVER
NORTHERN WISCONSIN AND TO AROUND 2 C OVER NORTHEAST IOWA. THIS
WILL SET THE STAGE FOR A CHILLY NIGHT ACROSS THE AREA SUNDAY NIGHT
INTO EARLY MONDAY MORNING. ECMWF 850 MB TEMPERATURE STANDARDIZED
ANOMALIES FALL TO AROUND -1.5...INDICATIVE OF AN ANOMALOUSLY COLD
AIRMASS. TEMPERATURES WILL PLUMMET INTO THE UPPER 30S OVER FAR
NORTHERN WISCONSIN. WILL HAVE TO KEEP A VERY CLOSE WATCH ON LOWS OVER
NORTH CENTRAL AND CENTRAL WISCONSIN WHERE TYPICAL COLD SPOTS SUCH
AS SPARTA AND BLACK RIVER FALLS COULD SEE LOWS DIP INTO THE UPPER
30S...LEADING TO FROST FORMATION. COOL HIGH PRESSURE REMAINS OVER
THE REGION THROUGH TUESDAY...WITH HIGHS ONLY IN THE 60S. HIGH
PRESSURE PUSHES EAST OF THE REGION LATE TUESDAY INTO WEDNESDAY AS
A TROUGH DIGS INTO THE DAKOTAS. SOUTHERLY FLOW DEVELOPS OVER THE
AREA HELPING TO USHER IN WARMER TEMPERATURES. THE TROUGH WILL MOVE
INTO THE FORECAST AREA LATE TUESDAY NIGHT THROUGH WEDNESDAY
BRINGING CHANCES FOR SHOWERS AND THUNDERSTORMS TO THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1159 PM CDT WED MAY 29 2013
CLUSTERS OF SHOWERS AND SCATTERED THUNDERSTORMS CONTINUE TO AFFECT
THE TAF SITES AS OF 05Z...BUT THEY ARE LIFTING NORTH. WITH
DIMINISHING INSTABILITY THROUGH THE EARLY MORNING HOURS...THINKING
ONLY A FEW MORE HOURS OF PRECIPITATION WILL OCCUR. VISIBILITIES
FOR THE MOST PART HAVE BEEN VFR...SO FOR NOW HANDLED THE TAFS WITH
VCSH. CEILINGS ARE ALSO HOLDING VFR AND SHOULD PERSIST THROUGH THE
REST OF THE NIGHT AS A SOUTHERLY BREEZE KEEPS THINGS MIXED.
REGARDING THAT SOUTHERLY BREEZE...40-50 KT WINDS ARE PRESENT
1000-2000 FT ABOVE THE GROUND. RECENT RAIN HAS ALLOWED WINDS AT
THE SURFACE TO BE LIGHTER THAN EXPECTED...ESPECIALLY AT
KLSE...THUS HAVE INCLUDED LOW LEVEL WIND SHEAR.
MORE SHOWER AND THUNDERSTORM ACTION SHOULD INITIATE A FEW HOURS
AFTER SUNRISE AS INSTABILITY INCREASES. ENOUGH CONFIDENCE EXISTS
TO HAVE A LONG PERIOD OF VCTS AT BOTH TAF SITES...FROM 17Z-02/03Z
AS PLENTIFUL FORCING EXISTS FOR OFF AND ON THUNDERSTORM ACTIVITY.
VISIBILITIES COULD BE TEMPORARILY REDUCED AS WELL...BUT NOT ENOUGH
CONFIDENCE EXISTS TO INCLUDE THIS IN THE FORECAST. CEILINGS SHOULD
HOLD VFR...AIDED BY DAYTIME HEATING. THIS SAME DAYTIME HEATING
WILL MIX THE STRONG AFORMENTIONED WINDS DOWN TO THE SURFACE...THUS
GUSTS OF 25-30 KT APPEAR LIKELY FOR THE AFTERNOON INTO THE EARLY
EVENING HOURS. THESE COULD BE EVEN HIGHER IF MORE SUN OCCURS.
BOTH WINDS AND THUNDERSTORM ACTIVITY SHOULD DIMINISH DURING THE
EVENING WITH LOSS OF HEATING.
&&
.HYDROLOGY...TODAY AND TONIGHT
ISSUED AT 333 AM CDT THU MAY 30 2013
HEAVY RAIN FELL ACROSS THE AREA WEDNESDAY AFTERNOON AND EVENING
WITH RAINFALL AMOUNTS OF 2 TO 3 INCHES REPORTED ACROSS PORTIONS OF
NORTHEAST IOWA...SOUTHEAST MINNESOTA AND SOUTHWEST
WISCONSIN...WITH LOCALLY HIGHER AMOUNTS OF 4 INCHES REPORTED. AN
ADDITIONAL 1 TO 2 INCHES OF RAIN IS EXPECTED ACROSS THE AREA
TODAY THROUGH THIS EVENING...WHICH COULD LEAD TO FLASH FLOODING.
IT WILL NOT TAKE MUCH RAIN OVER THE SATURATED SOILS TO CREATE
FLOODING ISSUES. ALSO...AREA RIVERS WILL SEE RISES AND POSSIBLE
FLOODING WITH ANY ADDITIONAL RAINFALL RECEIVED. HAVE EXPANDED THE
FLASH FLOOD WATCH NORTHWARD...INCLUDING AREAS ALONG AND SOUTHWEST
OF INTERSTATE 94 CORRIDOR EXCLUDING JUNEAU COUNTY
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR WIZ032>034-041-042-
053>055-061.
MN...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR MNZ079-086>088-
094>096.
IA...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR IAZ008>011-018-019-
029-030.
&&
$$
SHORT TERM...AJ/WETENKAMP
LONG TERM...WETENKAMP
AVIATION...AJ
HYDROLOGY...WETENKAMP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1159 PM CDT WED MAY 29 2013
.UPDATE...
ISSUED AT 714 PM CDT WED MAY 29 2013
HAVE EXPANDED THE FLASH FLOOD WATCH EVEN FARTHER EAST TO NOW
INCLUDE VERNON...CRAWFORD...RICHLAND AND GRANT COUNTIES IN
WISCONSIN. CLUSTER OF THUNDERSTORMS WITH HEAVY RAIN HAS ENTERED
THESE COUNTIES. MEANWHILE...THE ENTIRE MCS OVER THE FORECAST AREA
EXTENDING DOWN TO MARSHALLTOWN AND CEDAR RAPIDS IOWA SHOULD LIFT
NORTH THROUGH THE NIGHT...IN RESPONSE TO STRENGTHENING LOW LEVEL
JET / MOISTURE TRANSPORT. THIS MEANS THE EXPANDED FLASH FLOOD
WATCH AREA COULD SEE PERIODS OF MODERATE TO HEAVY RAINFALL FOR AT
LEAST THE NEXT FEW HOURS.
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 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1159 PM CDT WED MAY 29 2013
CLUSTERS OF SHOWERS AND SCATTERED THUNDERSTORMS CONTINUE TO AFFECT
THE TAF SITES AS OF 05Z...BUT THEY ARE LIFTING NORTH. WITH
DIMINISHING INSTABILITY THROUGH THE EARLY MORNING HOURS...THINKING
ONLY A FEW MORE HOURS OF PRECIPITATION WILL OCCUR. VISIBILITIES
FOR THE MOST PART HAVE BEEN VFR...SO FOR NOW HANDLED THE TAFS WITH
VCSH. CEILINGS ARE ALSO HOLDING VFR AND SHOULD PERSIST THROUGH THE
REST OF THE NIGHT AS A SOUTHERLY BREEZE KEEPS THINGS MIXED.
REGARDING THAT SOUTHERLY BREEZE...40-50 KT WINDS ARE PRESENT
1000-2000 FT ABOVE THE GROUND. RECENT RAIN HAS ALLOWED WINDS AT
THE SURFACE TO BE LIGHTER THAN EXPECTED...ESPECIALLY AT
KLSE...THUS HAVE INCLUDED LOW LEVEL WIND SHEAR.
MORE SHOWER AND THUNDERSTORM ACTION SHOULD INITIATE A FEW HOURS
AFTER SUNRISE AS INSTABILITY INCREASES. ENOUGH CONFIDENCE EXISTS
TO HAVE A LONG PERIOD OF VCTS AT BOTH TAF SITES...FROM 17Z-02/03Z
AS PLENTIFUL FORCING EXISTS FOR OFF AND ON THUNDERSTORM ACTIVITY.
VISIBILITIES COULD BE TEMPORARILY REDUCED AS WELL...BUT NOT ENOUGH
CONFIDENCE EXISTS TO INCLUDE THIS IN THE FORECAST. CEILINGS SHOULD
HOLD VFR...AIDED BY DAYTIME HEATING. THIS SAME DAYTIME HEATING
WILL MIX THE STRONG AFORMENTIONED WINDS DOWN TO THE SURFACE...THUS
GUSTS OF 25-30 KT APPEAR LIKELY FOR THE AFTERNOON INTO THE EARLY
EVENING HOURS. THESE COULD BE EVEN HIGHER IF MORE SUN OCCURS.
BOTH WINDS AND THUNDERSTORM ACTIVITY SHOULD DIMINISH DURING THE
EVENING WITH LOSS OF HEATING.
&&
.HYDROLOGY...TONIGHT THROUGH FRIDAY
ISSUED AT 714 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 AND SOUTHWEST
WISCONSIN THROUGH THU. THIS MAY NEED TO BE EXPANDED NORTHWARD AS
DETAILS OF TIMING/LOCATION OF THE CONTINUED HEAVY RAIN THREAT
BECOME CLEARER.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLASH FLOOD WATCH THROUGH THURSDAY EVENING FOR WIZ053>055-061.
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...AJ
HYDROLOGY....DAS/AJ
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
845 AM PDT THU MAY 30 2013
.DISCUSSION...AS OF 08:31 AM PDT THURSDAY...
FORECAST LOOKS ON TRACK THIS MORNING WITH EARLY MORNING
TEMPERATURES A FEW DEGREES COOLER THAN YESTERDAY AT THIS TIME.
GOOD RADIATIONAL COOLING NIGHT WITH LESS STRATUS THIS MORNING. WRF
MODEL CAPTURED BOUNDARY LAYER RH FIELD PRETTY WELL THIS MORNING
AND RESULTANT AREAS OF STRATUS. MODEL TRENDS TOWARD RAPID STRATUS
CLEARING THIS MORNING...BUT LOOKING AT VISIBLE SATELLITE IMAGERY
WOULD SUGGEST SLIGHTLY SLOWER CLEARING. SAN MATEO COAST AND WEST
SLOPES OF COAST RANGE AS WELL AS MONTEREY BAY SHOULD SEE GRADUAL
DISSIPATION OF LOW CLOUDS THROUGH THE MORNING WITH PRESSURE
GRADIENT BECOMING MORE NORTHERLY. NAM SUGGESTS INCREASING
NORTHERLY GRADIENT THROUGH FRIDAY FROM SFO TO ACV WITH INCREASING
850 MB TEMPERATURES. HIGHS THIS AFTERNOON SHOULD END UP A FEW
DEGREES WARMER INLAND WITH NOT MUCH CHANGE NEAR THE COAST. CURRENT
STATEMENTS STILL ON TRACK HIGHLIGHTING WARM INLAND TEMPERATURES
THIS WEEKEND AND HEIGHTENED FIRE WEATHER CONCERNS.
&&
...TURNING HOT INLAND FRIDAY AND SATURDAY...
.DISCUSSION...AS OF 3:48 AM PDT THURSDAY...MAIN FORECAST FOCUS WILL
DEAL WITH HIGH TEMPERATURE FORECASTS THE NEXT SEVERAL DAYS.
OVERALL IDEA WILL SHOW WARMING TREND STARTING TODAY AND CONTINUING
AT LEAST THROUGH SATURDAY...AND POSSIBLY SUNDAY FOR THE INLAND
VALLEYS. A FEW DAYS AGO THE MODELS WERE HINTING THAT THE THERMAL
TROUGH MAY SHIFT TO THE COAST FRIDAY OR SATURDAY MORNING. LATEST
MODELS SOLUTIONS AREN`T REALLY SHOWING THAT SO THE FLOW AT THE
SURFACE LOOKS TO REMAIN ONSHORE THROUGH THIS EVENT. THEREFORE HOT
WEATHER WILL BE CONFINED TO THE INLAND VALLEYS. THIS WOULD INCLUDE
THOSE LOCATIONS EAST OF THE EAST BAY HILLS AS WELL AS THE NORTH
BAY VALLEYS AND SANTA CLARA VALLEY. EVEN THOUGH ALL LOCATIONS WILL
OBSERVE A NOTED WARMING TREND...THE PRESENCE OF WESTERLY WINDS
THROUGH THE EVENT SHOULD KEEP ANY SERIOUS HEAT IN CHECK FOR
LOCATIONS INSIDE SF BAY AS WELL AS AROUND THE MONTEREY BAY. SO IF
ANYTHING WE SHOULD SET UP SOME WELL DEFINED MICRO-CLIMATES WITH
SOME POTENTIALLY HUGE TEMPERATURE SPREADS ACROSS THE DISTRICT BY
SATURDAY. SHOULD BE ABLE TO SEE TEMPERATURES RANGE FROM 60S AT THE
BEACHES TO AROUND 105 FOR THE WARMEST INLAND SPOTS.
OTHER ITEMS TO MONITOR WILL BE SOME LIGHT TO MODERATE NORTH WINDS
IN THE HILLS LATER FRIDAY NIGHT INTO EARLY SATURDAY AND THEN AGAIN
SATURDAY NIGHT. 850 MB TEMPS SHOULD STAY WELL ABOVE 20 CELSIUS SO
SOME HILL LOCATIONS ABOVE 1500 FEET WILL LIKELY SEE OVERNIGHT LOWS
AROUND 70 DEGREES WITH BREEZY NORTH WINDS AND POOR HUMIDITY
RECOVERY WHICH WILL BECOME A FIRE WEATHER CONCERN.
HOWEVER...SIMILAR TO THE HEAT IT WOULD APPEAR WE`LL STAY OUT OF
ANY WARNING CRITERIA FOR FIRE WEATHER OR HEAT RELATED PRODUCTS AT
THIS TIME. HAVE REFRESHED THE SPECIAL WEATHER STATEMENT TO KEEP
THE MESSAGE GOING FOR OVERALL CHANGE IN THE WEATHER...TO HOTTER
INLAND TEMPS.
ECMWF SOLUTION PINCHES OFF A 500 MB CIRCULATION JUST OFF THE
COAST BY SUNDAY. THIS WILL LIKELY INDUCE SOME SORT OF COASTAL COOLING
TREND IN THE FORM OF MARINE CLOUDS OR A SOUTHERLY WIND REVERSAL.
850 MB TEMPS WILL STAY AROUND 22 CELSIUS THROUGH SUNDAY AFTERNOON
SO ANY INLAND COOLING WILL BE MINOR AT BEST THROUGH THE WEEKEND.
BY MONDAY HEIGHTS WILL DROP...ONSHORE FLOW WILL INCREASE AND 850
MB TEMPS WILL NUDGE DOWNWARD AS WELL WHICH SHOULD LEAD TO A MARKED
INLAND COOLING TREND AS WELL.
FORECAST FOR NEXT WEEKS SHOWS A WEAK CIRCULATION OFF THE COAST
WHICH SHOULD KEEP A WELL DEFINED AND FAIRLY DEEP MARINE LAYER IN
PLACE. ANY CONVECTION WILL LIKELY STAY OVER THE SIERRA EVEN THOUGH
THE GFS WANTS TO SPIT SOME OUT CLOSER TO THE CENTER OF THE LOW. AS
THE CALENDAR TURNS TO JUNE A FORECAST NEAR CLIMATOLOGICAL NORMS
LOOKS PRETTY GOOD.
&&
.AVIATION...AS OF 4:45 AM PDT THURSDAY...MAINLY VFR CONDITIONS
OVER THE TERMINALS THROUGH THE FORECAST AS HIGH PRESSURE BEGINS TO
BUILD OVER THE REGION. PATCHES OF STRATUS FORMED OVER THE MONTEREY
BAY AND SAN MATEO COAST OVERNIGHT...AND ARE LIKELY TO EXPAND
THROUGH SUNRISE...MAINLY IMPACTING THE MONTEREY BAY TERMINALS.
OTHERWISE...MODERATE ONSHORE FLOW THIS AFTERNOON WITH PATCHY
STRATUS AGAIN FRIDAY MORNING.
VICINITY OF KSFO...VFR CONDITIONS THROUGH THE FORECAST.
STRENGTHENING NORTHERLY GRADIENTS WILL LIKELY KEEP STRATUS OUT OF
THE SF BAY TERMINALS. THERE IS A CHANCE THAT PATCHY STRATUS WILL
IMPACT KOAK THROUGH 17Z. MODERATE WEST WINDS TO 25 KT THIS
AFTERNOON THROUGH THE EARLY EVENING HOURS.
KSFO BRIDGE APPROACH...OCCASIONAL PATCHES OF STRATUS MAY DRIFT
OVER THE APPROACH THROUGH 17Z. LOW CONFIDENCE.
MONTEREY BAY AREA TERMINALS...IFR CIGS THROUGH 17Z. LOW
CONFIDENCE. MOST OF THE SHORT TERM MODELS INITIALIZED POORLY...WITH
ONLY THE LOCAL WRF AND HRRR INDICATING STRATUS MAY DEVELOP
OVERNIGHT. BOTH OF THESE MODELS ARE CONSISTENT IN THE FACT THAT
STRATUS WILL DISSIPATE BY 17Z. OTHERWISE...MODERATE WESTERLY WINDS
THIS AFTERNOON.
&&
.CLIMATE DATA FOR JUNE 1ST...
LOCATION FORECAST NORMAL RECORD TEMPERATURE
SANTA ROSA 92 77 95 1919
SAN RAFAEL 88 73 101 1960
NAPA 91 79 105 1960
SAN FRANCISCO 73 65 90 1989
OAKLAND 80 70 87 1989
LIVERMORE 98 80 105 1938
SANTA CRUZ 85 73 93 1912
SALINAS AIR 78 69 85 1935
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT ARENA TO PT REYES 0-10 NM
SCA...PIGEON PT TO PT PINOS 0-10 NM
SCA...PT ARENA TO PIGEON PT 10-60 NM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM
GLW...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
SCA...PT REYES TO PIGEON PT 0-10 NM
SCA...SF BAY FROM 2 PM
SCA...MRY BAY FROM 2 PM
&&
$$
PUBLIC FORECAST: KBB
AVIATION/MARINE: RILEY
CLIMATE: HENDERSON/LARRY
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.SANFRANCISCOBAYAREA.GOV
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
453 AM PDT THU MAY 30 2013
...TURNING HOT INLAND FRIDAY AND SATURDAY...
.DISCUSSION...AS OF 3:48 AM PDT THURSDAY...MAIN FORECAST FOCUS WILL
DEAL WITH HIGH TEMPERATURE FORECASTS THE NEXT SEVERAL DAYS.
OVERALL IDEA WILL SHOW WARMING TREND STARTING TODAY AND CONTINUING
AT LEAST THROUGH SATURDAY...AND POSSIBLY SUNDAY FOR THE INLAND
VALLEYS. A FEW DAYS AGO THE MODELS WERE HINTING THAT THE THERMAL
TROUGH MAY SHIFT TO THE COAST FRIDAY OR SATURDAY MORNING. LATEST
MODELS SOLUTIONS AREN`T REALLY SHOWING THAT SO THE FLOW AT THE
SURFACE LOOKS TO REMAIN ONSHORE THROUGH THIS EVENT. THEREFORE HOT
WEATHER WILL BE CONFINED TO THE INLAND VALLEYS. THIS WOULD INCLUDE
THOSE LOCATIONS EAST OF THE EAST BAY HILLS AS WELL AS THE NORTH
BAY VALLEYS AND SANTA CLARA VALLEY. EVEN THOUGH ALL LOCATIONS WILL
OBSERVE A NOTED WARMING TREND...THE PRESENCE OF WESTERLY WINDS
THROUGH THE EVENT SHOULD KEEP ANY SERIOUS HEAT IN CHECK FOR
LOCATIONS INSIDE SF BAY AS WELL AS AROUND THE MONTEREY BAY. SO IF
ANYTHING WE SHOULD SET UP SOME WELL DEFINED MICRO-CLIMATES WITH
SOME POTENTIALLY HUGE TEMPERATURE SPREADS ACROSS THE DISTRICT BY
SATURDAY. SHOULD BE ABLE TO SEE TEMPERATURES RANGE FROM 60S AT THE
BEACHES TO AROUND 105 FOR THE WARMEST INLAND SPOTS.
OTHER ITEMS TO MONITOR WILL BE SOME LIGHT TO MODERATE NORTH WINDS
IN THE HILLS LATER FRIDAY NIGHT INTO EARLY SATURDAY AND THEN AGAIN
SATURDAY NIGHT. 850 MB TEMPS SHOULD STAY WELL ABOVE 20 CELSIUS SO
SOME HILL LOCATIONS ABOVE 1500 FEET WILL LIKELY SEE OVERNIGHT LOWS
AROUND 70 DEGREES WITH BREEZY NORTH WINDS AND POOR HUMIDITY
RECOVERY WHICH WILL BECOME A FIRE WEATHER CONCERN.
HOWEVER...SIMILAR TO THE HEAT IT WOULD APPEAR WE`LL STAY OUT OF
ANY WARNING CRITERIA FOR FIRE WEATHER OR HEAT RELATED PRODUCTS AT
THIS TIME. HAVE REFRESHED THE SPECIAL WEATHER STATEMENT TO KEEP
THE MESSAGE GOING FOR OVERALL CHANGE IN THE WEATHER...TO HOTTER
INLAND TEMPS.
ECMWF SOLUTION PINCHES OFF A 500 MB CIRCULATION JUST OFF THE
COAST BY SUNDAY. THIS WILL LIKELY INDUCE SOME SORT OF COASTAL COOLING
TREND IN THE FORM OF MARINE CLOUDS OR A SOUTHERLY WIND REVERSAL.
850 MB TEMPS WILL STAY AROUND 22 CELSIUS THROUGH SUNDAY AFTERNOON
SO ANY INLAND COOLING WILL BE MINOR AT BEST THROUGH THE WEEKEND.
BY MONDAY HEIGHTS WILL DROP...ONSHORE FLOW WILL INCREASE AND 850
MB TEMPS WILL NUDGE DOWNWARD AS WELL WHICH SHOULD LEAD TO A MARKED
INLAND COOLING TREND AS WELL.
FORECAST FOR NEXT WEEKS SHOWS A WEAK CIRCULATION OFF THE COAST
WHICH SHOULD KEEP A WELL DEFINED AND FAIRLY DEEP MARINE LAYER IN
PLACE. ANY CONVECTION WILL LIKELY STAY OVER THE SIERRA EVEN THOUGH
THE GFS WANTS TO SPIT SOME OUT CLOSER TO THE CENTER OF THE LOW. AS
THE CALENDAR TURNS TO JUNE A FORECAST NEAR CLIMATOLOGICAL NORMS
LOOKS PRETTY GOOD.
&&
.AVIATION...AS OF 4:45 AM PDT THURSDAY...MAINLY VFR CONDITIONS
OVER THE TERMINALS THROUGH THE FORECAST AS HIGH PRESSURE BEGINS TO
BUILD OVER THE REGION. PATCHES OF STRATUS FORMED OVER THE MONTEREY
BAY AND SAN MATEO COAST OVERNIGHT...AND ARE LIKELY TO EXPAND
THROUGH SUNRISE...MAINLY IMPACTING THE MONTEREY BAY TERMINALS.
OTHERWISE...MODERATE ONSHORE FLOW THIS AFTERNOON WITH PATCHY
STRATUS AGAIN FRIDAY MORNING.
VICINITY OF KSFO...VFR CONDITIONS THROUGH THE FORECAST.
STRENGTHENING NORTHERLY GRADIENTS WILL LIKELY KEEP STRATUS OUT OF
THE SF BAY TERMINALS. THERE IS A CHANCE THAT PATCHY STRATUS WILL
IMPACT KOAK THROUGH 17Z. MODERATE WEST WINDS TO 25 KT THIS
AFTERNOON THROUGH THE EARLY EVENING HOURS.
KSFO BRIDGE APPROACH...OCCASIONAL PATCHES OF STRATUS MAY DRIFT
OVER THE APPROACH THROUGH 17Z. LOW CONFIDENCE.
MONTEREY BAY AREA TERMINALS...IFR CIGS THROUGH 17Z. LOW
CONFIDENCE. MOST OF THE SHORT TERM MODELS INITIALIZED POORLY...WITH
ONLY THE LOCAL WRF AND HRRR INDICATING STRATUS MAY DEVELOP
OVERNIGHT. BOTH OF THESE MODELS ARE CONSISTENT IN THE FACT THAT
STRATUS WILL DISSIPATE BY 17Z. OTHERWISE...MODERATE WESTERLY WINDS
THIS AFTERNOON.
&&
.CLIMATE DATA FOR JUNE 1ST...
LOCATION FORECAST NORMAL RECORD TEMPERATURE
SANTA ROSA 92 77 95 1919
SAN RAFAEL 88 73 101 1960
NAPA 91 79 105 1960
SAN FRANCISCO 73 65 90 1989
OAKLAND 80 70 87 1989
LIVERMORE 98 80 105 1938
SANTA CRUZ 85 73 93 1912
SALINAS AIR 78 69 85 1935
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT ARENA TO PT REYES 0-10 NM
SCA...PIGEON PT TO PT PINOS 0-10 NM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
SCA...PT ARENA TO PIGEON PT 10-60 NM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM
SCA...PT REYES TO PIGEON PT 0-10 NM
SCA...SF BAY FROM 2 PM
SCA...MRY BAY FROM 2 PM
&&
$$
PUBLIC FORECAST: RWW
AVIATION/MARINE: RILEY
CLIMATE: HENDERSON/LARRY
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.SANFRANCISCOBAYAREA.GOV
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS MIAMI FL
1036 AM EDT THU MAY 30 2013
.UPDATE...
THE FLOOD WATCH THAT WAS IN EFFECT FOR THE EASTERN HALF OF
SOUTH FLORIDA HAS BEEN CANCELLED. WHILE THE 12Z SOUNDING HAD A
PWAT NEAR TWO INCHES...THE OVERALL SYNOPTIC CONDITIONS ARE NOT
COMPLETELY FAVORABLE FOR WIDESPREAD CONVECTION ACROSS THE EASTERN
HALF OF SOUTH FLORIDA AND THE AREAL COVERAGE OF POTENTIALLY HEAVY
RAINFALL IS EXPECTED TO BE LESS. HOWEVER...LOCALLY HEAVY RAINFALL
IS STILL POSSIBLE ACROSS SOUTH FLORIDA TODAY BUT OVER ISOLATED
AREAS. TWO SYNOPTIC FACTORS THAT HAVE REDUCED THE CHANCES OF
CONVECTION OVER A MORE WIDESPREAD AREA INCLUDE THE POSITION OF THE
UPPER LEVEL TROUGH AND THE MID LEVEL LAPSE RATE/TEMPERATURE. THE
UPPER LEVEL TROUGH ACROSS THE SOUTHEASTERN U.S. IS ORIENTATED SUCH
THAT A WEAK RIDGE HAS BUILT ACROSS THE REGION AND THE 12Z SOUNDING
INDICATED 500 HPA TEMPERATURES THAT ARE REPRESENTATIVE OF
CLIMATOLOGY FOR THIS DATE. PLUS THE LAPSE RATES ABOVE 500 HPA ARE WEAK.
FOR THESE REASONS WIDESPREAD CONVECTION ACROSS THE EASTERN HALF OF
SOUTH FLORIDA IS LESS LIKELY AND THE FLOOD WATCH HAS BEEN
CANCELLED. HOWEVER...ABUNDANT LOW LEVEL MOISTURE CONTINUES ACROSS
THE REGION AND SOME DRIER MID TO UPPER LEVEL IS PRESENT. FOR THE
AFTERNOON AND EARLY EVENING...DAY TIME HEATING SHOULD RESULT IN
CONVECTION WITH ISOLATED THUNDERSTORMS POSSIBLE AND A SLIGHT
CHANCE OF SMALL HAIL. AND NEED TO RE-EMPHASIZE THAT LOCALLY HEAVY
RAINFALL WILL BE POSSIBLE IN ISOLATED AREAS.
REGIONAL OBSERVATIONS ACROSS THE LOCAL ATLANTIC WATERS INDICATE
STRONG WINDS IN THE 20 TO 24 KNOT RANGE POSSIBLE WITH A SMALL
CRAFT ADVISORY CONTINUING ACROSS THE ATLANTIC WATERS...INCLUDING
BISCAYNE BAY. A SMALL CRAFT ADVISORY FOR THE GULF WATERS CONTINUES
TO BE IN EFFECT THROUGH 00Z THIS EVENING BUT LATEST GUIDANCE
INDICATES THAT WINDS SHOULD SLOWLY SUBSIDE THROUGH THE DAY AND THAT
ADVISORY MAY BE CANCELLED WITH THE AFTERNOON ISSUANCE OF THE
COASTAL WATERS FORECAST.
60
&&
.PREV DISCUSSION... /ISSUED 700 AM EDT THU MAY 30 2013/
AVIATION...
BERMUDA HIGH CONTINUES TO BRING STRONG EASTERLY FLOW AND RAIN
SHOWERS TO SOUTH FLORIDA THROUGH THE TAF PERIOD. THE RAIN MAY BE
HEAVY AT TIMES, REDUCING FLIGHT CATEGORIES TO MVFR AND IFR FOR
SHORT PERIODS OF TIME. HOWEVER, WITH SUCH GREAT UNCERTAINTY AS TO
WHEN AND WHERE THIS WILL OCCUR, HAVE NOT REFLECTED THE REDUCTIONS
IN THE TAFS AT THIS TIME. WINDS WILL BE GUSTY ONCE AGAIN TODAY,
WITH SOME WEAKENING SOME TONIGHT.
PREV DISCUSSION... /ISSUED 238 AM EDT THU MAY 30 2013/
SHORT TERM (TODAY THROUGH SATURDAY)...
THE GLOBAL MODELS CONTINUE TO STRUGGLE WITH THE OVERALL SURFACE
SYNOPTIC PATTERN IN THIS PERIOD BUT ARE IN AGREEMENT THAT THE MID
LEVEL PRESSURE PATTERN WILL REMAIN QUITE WEEK ACROSS SOUTH
FLORIDA. THE GFS, ECMWF AND NAM ALL SHOW A WEAK 500 MB TROUGH
DEVELOPING EAST OF THE PENINSULA ON FRIDAY AND SATURDAY DRIFTING
IT TO THE NORTHEAST. THIS COULD ALLOW FOR SOME SLIGHT DRYING ALOFT
AS DRIER AIR MOVES SOUTHWARD ON THE WEST SIDE OF THE TROUGH. THIS
IS REFLECTED IN THE LATEST POP GUIDANCE FROM BOTH THE MET AND MAV
WHICH SHOW A TREND WITH LOWER NUMBERS AFTER TODAY. THE NAM AND GFS
HAVE COME MORE IN LINE AT THE SURFACE IN DEVELOPING A WEAK
INVERTED TROUGH OVER THE FLORIDA STRAITS ON FRIDAY AND DRIFTING IT
TO THE NORTH ON SATURDAY WHICH LESSENS THE LOW LEVEL SOUTHEAST
WIND FLOW SIGNIFICANTLY. THE ECMWF DOES NOT SHOW THIS FEATURE
MAINTAINING AN ONSHORE FLOW ALONG THE SOUTHEAST COAST ALTHOUGH IN
A WEAKENED STATE AS IT SHOWS THE RIDGE TO THE NORTH WEAKENING. THE
NAM HAS INITIALIZED THE BEST COMPARING IT TO CURRENT OBSERVATIONS
FROM THE C-MAN STATIONS BUT THE QUESTION WILL THE WEAK TROUGH
DEVELOP AS FORECAST FROM THE NAM AND GFS. EVEN THOUGH THE NAM AND
GFS HAVE BEEN CONSISTENT IN FORECASTING THIS TROUGH, THEY HAVE
BEEN VERY INCONSISTENT IN ITS TIMING. THEREFORE, WILL LEAN TOWARDS
THE NAM EARLY IN THE PERIOD BUT THEN GO MORE WITH THE ECMWF FOR
FRIDAY NIGHT AND SATURDAY.
THE OTHER FACTOR IN THE SHORT TERM IS THE AMOUNT OF RAINFALL THAT
IS POSSIBLE. MOST OF THE RAIN THE PAST FEW DAYS HAS BEEN
CONCENTRATED OVER THE EASTERN HALF OF THE SOUTHERN PENINSULA WITH
VERY SATURATED GROUNDS FROM PERSISTENT RAIN PERIODS SINCE APRIL.
GIVEN THE ONGOING ONSHORE FLOW OF MOIST AND UNSTABLE AIR AND
SCATTERED SHOWERS, THE FLOOD WATCH WILL CONTINUE THROUGH 12Z
FRIDAY. THE LATEST RUN OF THE HRRR WHICH TYPICALLY DOES QUITE WELL
DOES NOT SHOW MUCH ACTIVITY THROUGH EARLY THURSDAY. HOWEVER, WITH
VERY LITTLE CHANGE IN THIS PATTERN AT LEAST THROUGH THURSDAY NIGHT
THE SHOWER ACTIVITY COULD DEVELOP AT ANY TIME AND MOVE ONSHORE
WITHIN THE FLOOD WATCH BOX.
LONG TERM (SATURDAY NIGHT THROUGH WEDNESDAY)...
BOTH THE GFS AND ECMWF ARE IN GOOD AGREEMENT SHOWING A MID LEVEL
TROUGH DEEPENING ACROSS THE EASTERN U.S. MAINTAINING A RIDGE TO
THE WEST AND A WEAK PRESSURE PATTERN ACROSS SOUTH FLORIDA. AT THE
SURFACE, BOTH MODELS COME MORE IN LINE WITH A LIGHTER SOUTHEAST
FLOW AS THE RIDGE WEAKENS AND SHIFTS TO THE EAST AS A WEAK COLD
FRONT MOVES INTO THE SOUTHEAST STATES. HOWEVER, THE GFS THEN
DEVELOPS A STRONGER SURFACE TROUGH OVER THE GULF STATES LATE IN
THE PERIOD AND VEERS THE WIND ACROSS SOUTH FLORIDA TO THE
SOUTHWEST. BEING THIS LATE IN THE FORECAST, WILL NOT JUMP ON THAT
AND WILL LEAN MORE TOWARDS THE ECMWF SOLUTION THROUGH THE ENTIRE
EXTENDED PERIOD.
MARINE...
ROUGH MARINE CONDITIONS WILL CONTINUE THROUGH AT LEAST EARLY
FRIDAY. MODEL GUIDANCE HINTS AT SOME WEAKENING IN THE GRADIENT
FLOW LATE FRIDAY INTO THE WEEKEND WITH CALMER WIND AND SEAS. JUST
HOW MUCH WEAKENING DEPENDS ON THE RAPIDNESS OF THE SLACKENING
GRADIENT WITH TIME. FOR NOW, HAVE KEPT A SOUTHEAST FLOW WITH
SUBSIDING SPEEDS AS HIGH PRESSURE RETREATS TO THE EAST.
FIRE WEATHER...
NO PROBLEMS OR CONCERNS WITH AMPLE TROPICAL MOISTURE IN PLACE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 84 77 86 76 / 60 30 50 40
FORT LAUDERDALE 83 76 85 77 / 60 40 50 40
MIAMI 83 75 87 76 / 60 40 50 40
NAPLES 89 72 89 74 / 60 30 40 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...RIP CURRENT RISK THROUGH FRIDAY 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...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR COASTAL
WATERS FROM CHOKOLOSKEE TO BONITA BEACH, FL OUT 20 NM-
COASTAL WATERS FROM EAST CAPE SABLE TO CHOKOLOSKEE, FL OUT
20 NM-GULF WATERS FROM CHOKOLOSKEE TO BONITA BEACH, FL
EXTENDING FROM 20 TO 60 NM.
&&
$$
DISCUSSION/MARINE/FIRE...60/BD
AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION
NWS MIAMI FL
700 AM EDT THU MAY 30 2013
.AVIATION...
BERMUDA HIGH CONTINUES TO BRING STRONG EASTERLY FLOW AND RAIN
SHOWERS TO SOUTH FLORIDA THROUGH THE TAF PERIOD. THE RAIN MAY BE
HEAVY AT TIMES, REDUCING FLIGHT CATEGORIES TO MVFR AND IFR FOR
SHORT PERIODS OF TIME. HOWEVER, WITH SUCH GREAT UNCERTAINTY AS TO
WHEN AND WHERE THIS WILL OCCUR, HAVE NOT REFLECTED THE REDUCTIONS
IN THE TAFS AT THIS TIME. WINDS WILL BE GUSTY ONCE AGAIN TODAY,
WITH SOME WEAKENING SOME TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 238 AM EDT THU MAY 30 2013/
SHORT TERM (TODAY THROUGH SATURDAY)...
THE GLOBAL MODELS CONTINUE TO STRUGGLE WITH THE OVERALL SURFACE
SYNOPTIC PATTERN IN THIS PERIOD BUT ARE IN AGREEMENT THAT THE MID
LEVEL PRESSURE PATTERN WILL REMAIN QUITE WEEK ACROSS SOUTH
FLORIDA. THE GFS, ECMWF AND NAM ALL SHOW A WEAK 500 MB TROUGH
DEVELOPING EAST OF THE PENINSULA ON FRIDAY AND SATURDAY DRIFTING
IT TO THE NORTHEAST. THIS COULD ALLOW FOR SOME SLIGHT DRYING ALOFT
AS DRIER AIR MOVES SOUTHWARD ON THE WEST SIDE OF THE TROUGH. THIS
IS REFLECTED IN THE LATEST POP GUIDANCE FROM BOTH THE MET AND MAV
WHICH SHOW A TREND WITH LOWER NUMBERS AFTER TODAY. THE NAM AND GFS
HAVE COME MORE IN LINE AT THE SURFACE IN DEVELOPING A WEAK
INVERTED TROUGH OVER THE FLORIDA STRAITS ON FRIDAY AND DRIFTING IT
TO THE NORTH ON SATURDAY WHICH LESSENS THE LOW LEVEL SOUTHEAST
WIND FLOW SIGNIFICANTLY. THE ECMWF DOES NOT SHOW THIS FEATURE
MAINTAINING AN ONSHORE FLOW ALONG THE SOUTHEAST COAST ALTHOUGH IN
A WEAKENED STATE AS IT SHOWS THE RIDGE TO THE NORTH WEAKENING. THE
NAM HAS INITIALIZED THE BEST COMPARING IT TO CURRENT OBSERVATIONS
FROM THE C-MAN STATIONS BUT THE QUESTION WILL THE WEAK TROUGH
DEVELOP AS FORECAST FROM THE NAM AND GFS. EVEN THOUGH THE NAM AND
GFS HAVE BEEN CONSISTENT IN FORECASTING THIS TROUGH, THEY HAVE
BEEN VERY INCONSISTENT IN ITS TIMING. THEREFORE, WILL LEAN TOWARDS
THE NAM EARLY IN THE PERIOD BUT THEN GO MORE WITH THE ECMWF FOR
FRIDAY NIGHT AND SATURDAY.
THE OTHER FACTOR IN THE SHORT TERM IS THE AMOUNT OF RAINFALL THAT
IS POSSIBLE. MOST OF THE RAIN THE PAST FEW DAYS HAS BEEN
CONCENTRATED OVER THE EASTERN HALF OF THE SOUTHERN PENINSULA WITH
VERY SATURATED GROUNDS FROM PERSISTENT RAIN PERIODS SINCE APRIL.
GIVEN THE ONGOING ONSHORE FLOW OF MOIST AND UNSTABLE AIR AND
SCATTERED SHOWERS, THE FLOOD WATCH WILL CONTINUE THROUGH 12Z
FRIDAY. THE LATEST RUN OF THE HRRR WHICH TYPICALLY DOES QUITE WELL
DOES NOT SHOW MUCH ACTIVITY THROUGH EARLY THURSDAY. HOWEVER, WITH
VERY LITTLE CHANGE IN THIS PATTERN AT LEAST THROUGH THURSDAY NIGHT
THE SHOWER ACTIVITY COULD DEVELOP AT ANY TIME AND MOVE ONSHORE
WITHIN THE FLOOD WATCH BOX.
LONG TERM (SATURDAY NIGHT THROUGH WEDNESDAY)...
BOTH THE GFS AND ECMWF ARE IN GOOD AGREEMENT SHOWING A MID LEVEL
TROUGH DEEPENING ACROSS THE EASTERN U.S. MAINTAINING A RIDGE TO
THE WEST AND A WEAK PRESSURE PATTERN ACROSS SOUTH FLORIDA. AT THE
SURFACE, BOTH MODELS COME MORE IN LINE WITH A LIGHTER SOUTHEAST
FLOW AS THE RIDGE WEAKENS AND SHIFTS TO THE EAST AS A WEAK COLD
FRONT MOVES INTO THE SOUTHEAST STATES. HOWEVER, THE GFS THEN
DEVELOPS A STRONGER SURFACE TROUGH OVER THE GULF STATES LATE IN
THE PERIOD AND VEERS THE WIND ACROSS SOUTH FLORIDA TO THE
SOUTHWEST. BEING THIS LATE IN THE FORECAST, WILL NOT JUMP ON THAT
AND WILL LEAN MORE TOWARDS THE ECMWF SOLUTION THROUGH THE ENTIRE
EXTENDED PERIOD.
MARINE...
ROUGH MARINE CONDITIONS WILL CONTINUE THROUGH AT LEAST EARLY
FRIDAY. MODEL GUIDANCE HINTS AT SOME WEAKENING IN THE GRADIENT
FLOW LATE FRIDAY INTO THE WEEKEND WITH CALMER WIND AND SEAS. JUST
HOW MUCH WEAKENING DEPENDS ON THE RAPIDNESS OF THE SLACKENING
GRADIENT WITH TIME. FOR NOW, HAVE KEPT A SOUTHEAST FLOW WITH
SUBSIDING SPEEDS AS HIGH PRESSURE RETREATS TO THE EAST.
FIRE WEATHER...
NO PROBLEMS OR CONCERNS WITH AMPLE TROPICAL MOISTURE IN PLACE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 84 77 86 76 / 60 30 50 40
FORT LAUDERDALE 83 76 85 77 / 70 40 50 40
MIAMI 83 75 87 76 / 70 40 50 40
NAPLES 89 72 89 74 / 60 30 40 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...FLOOD WATCH THROUGH FRIDAY MORNING FOR COASTAL BROWARD-COASTAL
MIAMI DADE-COASTAL PALM BEACH-FAR SOUTH MIAMI DADE-INLAND
BROWARD-INLAND MIAMI DADE-INLAND PALM BEACH-METRO BROWARD-
METRO MIAMI DADE-METRO PALM BEACH.
RIP CURRENT RISK THROUGH FRIDAY 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...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR COASTAL
WATERS FROM CHOKOLOSKEE TO BONITA BEACH, FL OUT 20 NM-
COASTAL WATERS FROM EAST CAPE SABLE TO CHOKOLOSKEE, FL OUT
20 NM-GULF WATERS FROM CHOKOLOSKEE TO BONITA BEACH, FL
EXTENDING FROM 20 TO 60 NM.
&&
$$
DISCUSSION/MARINE/FIRE...30/KOB
AVIATION/RADAR...13/SI
AREA FORECAST DISCUSSION
NWS POCATELLO ID
922 AM MDT THU MAY 30 2013
.UPDATE...NO UPDATES PLANNED FOR TODAY. ELONGATED UPPER TROUGH
LAYING ACROSS THE AREA TODAY. WEAK SHORTWAVE IN PLACE OVER
SOUTHERN IDAHO AND WEAK CONVECTION STILL ONGOING IN PORTIONS OF
EASTERN HIGHLANDS PER RADAR IMAGERY. EASTERN IDAHO WEAKLY
DESTABILIZED THIS AFTERNOON WITH 0 TO -2 LIFTEDS MAINLY NORTH OF
KSUN-KPIH LINE. HRRR CONCURS WITH WEAK CONVECTION NORTH OF THIS
LINE BUT ALSO STRETCHING SLIGHTLY SOUTH THROUGH THE EASTERN
HIGHLANDS TO THE BEAR LAKE AREA...CLOSE TO SECONDARY AREA OF
INSTABILITY OVER NORTHERN UTAH. REST OF THE FORECAST AREA LARGELY
DRY AND STABLE. ONLY OTHER CONCERN WILL BE WINDS ACROSS THE SNAKE
PLAIN. GUIDANCE CONTINUES TO INDICATE ADVISORY LEVEL WINDS THIS
AFTERNOON AT KPIH SO WILL CONTINUE WIND ADVISORY FOR THE ENTIRE
ZONE. EVEN IF WINDS ARE MARGINAL FOR THIS ADVISORY...LAKE WIND
ADVISORY IS CERTAIN SO WILL LEAVE HEADLINE IN PLACE REGARDLESS. DMH
&&
.PREV DISCUSSION... /ISSUED 315 AM MDT THU MAY 30 2013/
DISCUSSION...UPPER LOW IS SITTING OFF IN THE EAST PACIFIC JUST WEST
OF VANCOUVER ISLAND. WV IMAGERY SHOWS A COUPLE OF WEAK IMPULSES OF
ENERGY ROTATING OUT OF THE LOW. MODELS PROJECT LITTLE SENSIBLE
WEATHER ASSOCIATED WITH THESE IMPULSES...AND WEATHER SHOULD BE
RELATIVELY CLEAR ACROSS THE AREA TODAY. AS A RESULT...LOW LEVEL
LAPSE RATES WILL STEEPEN ALLOWING SOME OF THE STRONGER WINDS TO MIX
TO THE SURFACE THIS AFTERNOON. MOS GUIDANCE IS INDICATING STRONGER
WINDS THAN YESTERDAY AND WE WILL LIKELY SEE ADVISORY LEVEL WIND
SPEEDS THIS AFTERNOON ACROSS THE LOWER SNAKE RIVER PLAIN. DRY
WEATHER SHOULD CONTINUE THROUGH SATURDAY AS UPPER RIDGING MOVES
ACROSS THE AREA.
ON SUNDAY...MODELS DEPICT AN AMPLIFYING UPPER TROUGH DEVELOPING OVER
THE PACIFIC NORTHWEST...BUT CONTINUE TO PUSH MOST OF THE MOISTURE
OVER NORTHERN IDAHO AND WESTERN MONTANA. THEREFORE WE SHOULD SEE
LITTLE IN THE WAY OF POPS EARLY NEXT WEEK. THE 00Z GFS/ECMWF DROPS
AN UPPER TROUGH OVER THE UPPER SNAKE HIGHLANDS...WHICH MAY BE THE
ONLY AREA OF CONCERN IN THE EXTENDED PERIODS AS FAR AS POPS ARE
CONCERNED. HINSBERGER
AVIATION...ISOLATED THUNDERSTORMS EXPECTED OVER THE CENTRAL
MOUNTAINS NORTH OF KSUN THIS AFTERNOON AND THE EASTERN HIGHLANDS AS
WELL. TAF SITES SHOULD NOT BE AFFECTED TODAY BY THESE SHOWERS. MAIN
CONCERN WILL BE STRONG SURFACE WINDS IN THE SNAKE PLAIN THIS
AFTERNOON. STRONGEST WINDS WILL BE IN THE VICINITY OF KPIH WHERE A
WIND ADVISORY HAS BEEN ISSUED FOR SOUTHWEST WINDS OF 25 TO 35 MPH
BETWEEN 20Z AND 03Z THIS EVENING. RS/EP
FIRE WEATHER...THE STORM TRACK HAS SHIFTED FURTHER NORTH TODAY.
ISOLATED SHOWERS AND THUNDERSTORMS ARE EXPECTED OVER THE MOUNTAINS
MAINLY NORTH OF A STANLEY TO DRIGGS LINE THIS AFTERNOON. STRONG
GUSTY WINDS WILL REDEVELOP AGAIN THIS AFTERNOON IN THE SNAKE
PLAIN...STRONGEST WINDS WILL BE LOCATED IN THE SOUTHERN HALF OF THE
PLAIN FROM BURLEY TO BLACKFOOT. WEST TO SOUTHWEST WINDS OF 25 TO 35
MPH ARE EXPECTED FROM 1400 TO 2100 HOURS. ON FRIDAY...ISOLATED
SHOWERS WILL BE LIMITED TO AREAS FROM LEADORE TO ISLAND PARK AND
DRIGGS. RELATIVE HUMIDITY WILL LOWER TO AROUND 20 PERCENT AROUND
ARCO FRIDAY AND TREND DOWNWARD TO THE UPPER TEENS BY SATURDAY
AFTERNOON. RS/EP
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 2 PM THIS AFTERNOON TO 9 PM MDT THIS EVENING
IDZ021.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1030 AM CDT THU MAY 30 2013
.DISCUSSION...
ISSUED 1030 AM CDT THU MAY 30 2013
MORNING SURFACE ANALYSIS SHOWS HIGH PRESSURE ANCHORED ALONG THE
EAST COAST AND LOW PRESSURE CENTERED OVER SOUTH DAKOTA. THE
PRESSURE GRADIENT BETWEEN THESE TWO FEATURES IS CREATING
STRONG/GUSTY SOUTHERLY WINDS ACROSS CENTRAL ILLINOIS...WITH THE
15Z/10AM OBS INDICATING GUSTS ALREADY EXCEEDING 30 MPH IN A FEW
LOCATIONS. RADAR MOSAIC HAS BEEN FAIRLY QUIET SO FAR...WITH ONLY A
FEW ISOLATED SHOWERS ACROSS EAST-CENTRAL ILLINOIS EARLIER THIS
MORNING. DESPITE RATHER BULLISH PRECIP DEVELOPMENT IN THE WARM
SECTOR AS ADVERTISED BY THE 12Z NAM...THINK ONLY ISOLATED
SHOWERS/THUNDER WILL OCCUR ACROSS THE AREA THROUGH EARLY
AFTERNOON. AS ATMOSPHERE DESTABILIZES...SCATTERED SHOWERS/STORMS
WILL DEVELOP BY MID TO LATE AFTERNOON. LATEST HRRR SUGGESTS THE
MOST WIDESPREAD CONVECTION WILL REMAIN WEST OF THE MISSISSIPPI
RIVER UNTIL THIS EVENING WHEN STORMS TRACK INTO AT LEAST THE
WESTERN HALF OF THE KILX CWA. HAVE UPDATED FORECAST TO LOWER POPS
THIS MORNING...FEATURING ONLY ISOLATED SHOWERS THROUGH EARLY
AFTERNOON. WILL GO WITH SCATTERED WORDING THIS AFTERNOON...THEN
WILL HIT POPS HARD TONIGHT WHEN BETTER FORCING APPROACHES FROM THE
WEST. ZONE UPDATE HAS ALREADY BEEN ISSUED.
BARNES
&&
.AVIATION...
ISSUED 627 AM CDT THU MAY 30 2013
A STRONG LOW LEVEL JET AND AMPLY MOISTURE IN THE LOWER TROPOSPHERE WILL
FUEL SHOWERS AND STORMS TODAY AND TONIGHT. THE TIMING OF THE
STORMS IS STILL IN QUESTION...BUT HIGHER CHANCES APPEAR TO BE LATER
THIS AFTERNOON AND THIS EVENING. WILL CONTINUE WITH TEMPO GROUPS
FOR MVFR VIS AND CIG DURING THAT TIME. A FEW STORMS MAY BUBBLE UP
IN THE WEAKLY CAPPED AIRMASS ALREADY BY 17Z FOR PIA AND SPI. RADAR
AND SATELLITE LOOPS SHOW CONVECTIVE ELEMENTS ALREADY APPROACHING
SOUTHWESTERN IL FROM MISSOURI...ASSOCIATED WITH A MESOSCALE VORTEX
THAT WILL CLIP WESTERN IL THIS MORNING. THE REMNANTS OF THOSE
EARLY MORNING STORMS COULD AFFECT PIA AND SPI LATER THIS MORNING.
OTHERWISE...A STRONGER LINE OF STORMS IS FORECAST TO DEVELOP IN
MISSOURI LATER THIS AFTERNOON AND MOVE INTO CENTRAL IL. SOME
MODELS TIME THE STORMS STARTING IN THE EVENING...BUT WITH
BOUNDARIES STILL IN THE AREA...WE MAY SEE SPORADIC STORMS ERUPT
THIS AFTERNOON EVEN AHEAD OF THAT SYSTEM.
MVFR OR IFR CONDITIONS ARE POSSIBLE DURING THE STRONGER
STORMS...BUT THE TIMING OF IFR IS TOO VAGUE AT THIS POINT...SO WE
DID NOT GO THAT LOW WITH THIS SET OF TAFS.
WINDS WILL INCREASE QUICKLY THIS MORNING AS 55KT WINDS ARE NOT FAR
OFF OF THE SURFACE. SOUTHERLY GUSTS TODAY MAY REACH OVER 30KT AT
TIMES. IT WILL REMAIN BREEZY EVEN AFTER SUNSET THIS EVENING...WITH
SUSTAINED WINDS IN THE 14-17KT RANGE THROUGH AT LEAST 06Z.
SHIMON
&&
.HYDROLOGY...
ISSUED 316 AM CDT THU MAY 30 2013
FLASH FLOOD GUIDANCE REMAINS LOW /LESS THAN 1.5 IN/HR/ FOR AREAS WEST
OF I-55 WHICH RECEIVED HEAVIER RAINS IN RECENT DAYS. THE POTENTIAL
EXISTS FOR SEVERAL ROUNDS OF CONVECTION TO IMPACT THESE AREAS
AGAIN LATER TODAY AND ESPECIALLY FRIDAY...INTO SATURDAY UNTIL THE
COLD FRONT PASSES. CURRENT FORECASTS SHOW 2 TO 4 INCHES OF
RAIN...WITH HIGHER AMOUNTS POSSIBLE IF TRAINING OF STORMS OCCURS.
THUS WILL HAVE A FLASH FLOOD WATCH I-55 AND WEST IN EFFECT THIS
AFTERNOON THROUGH SATURDAY AFTERNOON. MUCH OF THE ADDITIONAL RAIN
WILL RUN OFF INTO CREEKS...STREAMS...AND RIVERS. THIS WILL CAUSE
ADDITIONAL RISES ON RIVERS THAT ARE ALREADY IN FLOOD...INCLUDING
THE SPOON AND ILLINOIS. PORTIONS OF THE MACKINAW AND SANGAMON
RIVERS WILL ALSO BE PRONE TO FLOODING IF THE HEAVIER RAINS DO
MATERIALIZE.
25
&&
.PREV DISCUSSION...
ISSUED 316 AM CDT THU MAY 30 2013
SHORT TERM...TODAY THROUGH SATURDAY
07Z SURFACE MAP SHOWED DOUBLE-BARREL LOW PRESSURE OVER THE PLAINS
WITH ONE LOW CENTER IN CENTRAL SD AND A SOUTHERN LOW NEAR THE
OK/TX PANHANDLE. TIGHTENING MSLP GRADIENT BETWEEN THIS AND SFC
HIGH ALONG THE EAST COAST CAUSED 10-20 MPH S/SE WINDS
OVERNIGHT...KEEPING DEWPOINTS UP IN THE MID 60S AND EARLY MORNING
TEMPS IN THE UPPER 60S TO LOWER 70S. NEGATIVELY TILTED MID LEVEL
TROF WAS LIFTING INTO THE WESTERN HIGH PLAINS RESPONSIBLE FOR
LARGE AREA OF CONVECTION FROM THE PLAINS INTO THE UPPER MIDWEST.
WATER VAPOR IMAGERY INDICATED A WEAK WAVE AND MID LEVEL MOISTURE
POOL TRACKING NORTH FROM THE LOWER MS VALLEY...ON THE BACK SIDE OF
THE SUB-TROPICAL RIDGE CENTERED OFF THE EAST COAST. SHORT RANGE
HI-RES MODELS DEVELOP CONVECTION WITH THIS FEATURE AS IT SHIFTS NE
INTO THE LOWER OHIO VALLEY THIS MORNING...AND LATEST RADAR MOSAIC
INDICATED A SHOWER IN EAST CENTRAL IL AND A FEW MORE IN SE MO.
THUS MAY SEE A SLIGHTLY MORE FOCUSED AREA OF SCATTERED
SHOWERS/STORMS EAST OF I-57 INTO MID MORNING. OTHERWISE DEEPER
CONVECTION IS EXPECTED TO DEVELOP OVER MISSOURI AND IOWA THIS
AFTERNOON ASSOCIATED WITH A SIGNIFICANT SHORTWAVE EJECTING OUT OF
THE WESTERN TROF. CONVECTIVE MODELS SHOW THIS ENTERING THE WESTERN
CWA LATER THIS AFTERNOON AND EVENING...IN A WEAKENING FASHION AS
LESS INSTABILITY IS INDICATED EAST OF THE MS RIVER. MOIST PROFILES
ALSO SUGGEST A LOWER SVR THREAT...HOWEVER WITH DECENT WIND FIELDS
ALOFT WOULD NOT BE SURPRISED TO SEE SOME STRONG OR NEAR SVR
STORMS. ASIDE FROM POSSIBLE CONVECTION...ANOTHER ISSUE WILL BRISK
AND GUSTY SOUTH WINDS IN TIGHT GRADIENT. BUFKIT DATA SHOWS GUSTS
OVER 30 KTS DURING PEAK HEATING BUT CLOUD COVER COULD TEMPER
HIGHER GUSTS.
FAIRLY STRONG MODEL SIGNALS THAT AN MCS WILL FORM OVER KS/MO
TONIGHT AND LIFT NORTHEAST INTO THE CWA ON FRIDAY. THIS
SHOULD BE MAINTAINED BY A VIGOROUS 40-60 KT LLJ AND COULD BRING
ANOTHER ROUND OF HEAVY RAIN TO THE NW CWA INTO MIDDAY. THE EFFECTS
OF THIS MCS WILL IMPACT CONVECTIVE DEVELOPMENT LATER IN THE DAY
AND IF ATMOSPHERE CAN RECOVER THEN STRONG STORMS MAY REDEVELOP ALONG
THE LINGERING OUTFLOW BOUNDARY. BETTER WIND FIELDS ALOFT
ASSOCIATED WITH THE APPROACHING UPPER TROF WILL CONTRIBUTE TO
HIGHER BULK SHEAR AND THE POTENTIAL FOR MORE ORGANIZED SEVERE
WEATHER.
AS THE UPPER TROF STEADILY SHIFTS EAST...IT WILL DRIVE A COLD
FRONT INTO THE STATE ON SATURDAY. FRONTAL TIMING WILL BE CRITICAL
FOR ANOTHER ROUND OF POSSIBLE SEVERE STORMS AND HEAVY RAIN...AND
00Z MODELS ARE A FEW HOURS QUICKER WITH THE FRONT THAT PREVIOUS
RUNS. THIS WOULD FAVOR BEST CHANCE OF REDEVELOPMENT ALONG THE
FRONT OR PRE-FRONTAL TROF FOR THE CENTRAL OR EASTERN CWA SATURDAY
AFTERNOON INTO EVENING.
WITH THE THREAT FOR HEAVY RAIN STARTING LATER THIS AFTERNOON
ACROSS THE WEST...AND CONTINUING UNTIL THE COLD FRONTAL PASSAGE
SATURDAY HAVE DECIDED TO GO WITH ANOTHER FLASH FLOOD WATCH
ALONG/WEST OF I-55. THIS WILL BE IN EFFECT THIS AFTERNOON THROUGH
SATURDAY AFTERNOON. SEE HYDROLOGY SECTION BELOW FOR MORE INFO ON
HEAVY RAIN/FLOOD POTENTIAL.
LONG TERM...SUNDAY THROUGH WEDNESDAY
THE POST-FRONTAL AIRMASS WILL BRING A RETURN TO MUCH COOLER AND
DRIER WEATHER FOR THE LAST HALF OF THE WEEKEND. A DEEP TROF IS
FORECAST TO ROTATE SOUTH INTO THE NORTHERN GREAT LAKES BY LATE
SUNDAY WITH A CHILLY...FOR EARLY SUMMER...-24C 500 MB AIRMASS.
CANADIAN HIGH PRESSURE AT THE SURFACE WILL BUILD INTO THE GREAT
LAKES BY EARLY NEXT WEEK...AND CONTINUE TO PROVIDE A COOL
NORTHERLY FLOW TO CENTRAL IL. THUS TEMPERATURES ARE EXPECTED TO BE
SEVERAL DEGREES BELOW NORMAL INTO TUESDAY. BY LATE TUESDAY AND
WEDNESDAY...THE NEXT UPPER LEVEL WAVE PUSHING INTO THE PLAINS WILL
DEVELOP LOW PRESSURE TO OUR WEST. WARM ADVECTION PRECIP WITH THIS
FEATURE WILL SPREAD RAIN CHANCES EAST OF THE MS RIVER FOR MID-
WEEK.
25
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH SATURDAY EVENING FOR ILZ027>031-
036>038-040>042-047>051.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
1037 AM EDT THU MAY 30 2013
.UPDATE...
ISSUED AT 1037 AM EDT THU MAY 30 2013
NDFD AND WEB SERVERS HAVE BEEN UPDATED FOR LATEST SATELLITE AND
SURFACE OBSERVATIONAL TRENDS. ZFP UPDATE NOT NEEDED AT THIS TIME. THE
12Z HRRR POINTS TOWARDS ISOLATED SHOWERS BEING POSSIBLE OVER THE FAR
WESTERN PART OF THE FORECAST AREA FOR A FEW HOURS THIS
AFTERNOON...SIMILAR TO YESTERDAY. EXPECT PROBABILITY TO REMAIN
BELOW 15 PERCENT AND WILL NOT ADD THIS TO FORECAST. THE 12Z NAM
SUPPORTS A DRY FORECAST THIS AFTERNOON....WITH LOW PROBABILITY OF
SHOWERS IN THE WESTERN PART OF THE AREA TONIGHT. THIS IS IN THE CURRENT
FORECAST FOR TONIGHT AND WILL LEAVE AS IS FOR NOW.
UPDATE ISSUED AT 750 AM EDT THU MAY 30 2013
UPDATED THE FORECAST MAINLY TO KEEP THE NEAR TERM GRIDS ON TRACK WITH
THE CURRENT OBS AND TRENDS...INCLUDING SKY COVER. UPDATES HAVE BEEN
SENT TO THE NDFD AND WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 335 AM EDT THU MAY 30 2013
06Z SFC ANALYSIS SHOWS HIGH PRESSURE TO THE EAST OF KENTUCKY AND DEEP
LOW PRESSURE WELL TO THE NORTHWEST. A SOUTHERN FLOW OF WARMTH AND
MOISTURE CONTINUES THROUGH THE STATE BETWEEN THESE TWO KEY FEATURES.
ON SATELLITE...SOME HIGH CLOUDS AND A SMALLER BATCH OF LOWER ONES ARE
CROSSING EAST KENTUCKY EARLY THIS MORNING. THESE CLOUDS HAVE ONLY
HAD A SMALL IMPACT ON THE RADIATIONAL COOLING THROUGH THE CWA THIS
NIGHT WITH RIDGES STAYING UP IN THE UPPER 60S AND LOWER 70S WHILE THE
MOST SHELTERED VALLEYS CONTINUE THEIR PLUNGE INTO THE UPPER AND
MIDDLE 50S. ALSO SIMILAR TO LAST NIGHT...DEEPER LOCATIONS IN THE
WESTERN PORTIONS OF THE CUMBERLAND VALLEY...WEST OF I-75...ARE
STAYING A BIT MILDER WHEN COMPARED TO VALLEYS FURTHER EAST. AT THE
SAME TIME...DEWPOINTS ARE IN THE LOWER 60S THROUGHOUT THE AREA. WITH
THE VALLEY TEMPS FALLING TO NEAR THEIR DEWPOINTS...DO EXPECT SOME
LIGHT FOG TO DEVELOP IN THE PREDAWN HOURS...BUT STILL BE MAINLY
CONFINED TO THE LOCATIONS ALONG RIVERS AND OTHER BODIES OF WATER.
THE MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE UPPER LEVEL PATTERN
AFFECTING THE REGION THROUGH THE SHORT TERM. THEY ALL SHOW THE
SOUTHEAST RIDGE STRONGLY INFLUENCING EAST KENTUCKY FOR AT LEAST ONE
MORE DAY WHILE A LARGE AREA OF TROUGHING CONSOLIDATES OVER THE HIGH
PLAINS. HEIGHTS WILL START TO FALL LOCALLY LATER TONIGHT AS THE BROAD
TROUGH TO THE NORTHWEST PRESSES IN ON THE WESTERN FRINGES OF THE OHIO
VALLEY. THIS PROCESS WILL BE ACCOMPANIED BY A LEADING BAND OF
SHORTWAVE ENERGY CROSSING INTO THE REGION BY DAWN FRIDAY...JUST NORTH
OF THE OHIO RIVER. THIS BAND WEAKENS DURING THE DAY FRIDAY AS IT
ADVANCES EAST INTO THE RETREATING RIDGE. THE NAM12 AND GFS HAVE
SIMILAR IDEAS WITH THIS FIRST BATCH OF ENERGY AND ITS EFFECT ON
WEATHER SO HAVE GONE WITH A BLEND OF THESE TWO MODELS FOR WX
SPECIFICS THROUGH FRIDAY.
SENSIBLE WEATHER WILL SEE THE WARM AND INCREASINGLY MUGGY AIR MASS
SET THE STAGE FOR MORE IN THE WAY OF CONVECTION TO CLOSE OUT THE WORK
WEEK. HIGHER PW AIR CONTINUES TO BUILD OVER EAST KENTUCKY TODAY AND
FRIDAY. STILL CANNOT RULE OUT SOME STRAY POP UP STORMS LATE THIS
AFTERNOON...MAINLY JUST TO OUR WEST...BUT WITH CHANCES STILL TOO LOW
TO MENTION IN THE ZONES OR REPRESENT IN THE WX GRIDS AT THIS TIME.
THIS IS DESPITE LOW LIS AND MODERATELY HIGH CAPE...AS A TRIGGER WILL
BE HARD TO COME BY UNTIL LATER. A BETTER CHANCE FOR CONVECTION WILL
OCCUR LATER TONIGHT...AGAIN PRIMARILY OVER OUR WESTERN ZONES...AS
THE APPROACHING MID LEVEL WAVE WILL HELP YO ACTIVATE THIS
INCREASINGLY SOUPY AIR MASS. THIS DEVELOPMENT WILL KEEP A DECENT
THREAT OF SHOWERS AND THUNDERSTORMS IN THE FORECAST THROUGHOUT THE
DAY FRIDAY...WORKING WEST TO EAST WITH TIME. THE EXPECTED INCREASE IN
CLOUD COVER AND CONVECTION WILL ALSO LIKELY SERVE TO CAP TEMPERATURES
IN THE MID 80S ON FRIDAY...A TAD LOWER THAN TODAY. BEFORE THE MORE
ORGANIZED AREA OF CONVECTION GETS GOING LATE TONIGHT...DO EXPECT
ANOTHER SMALL TO MODERATE RIDGE AND VALLEY TEMPERATURE SPLIT TO
DEVELOP BY LATE EVENING THOUGH MUCH OF THIS WILL BE WASHED OUT BY THE
LOWER CLOUDS AND SCATTERED COVERAGE OF SHOWERS AND THUNDERSTORMS
TOWARD DAWN FRIDAY.
HAVE USED THE CONSSHORT FOR TD AND WINDS THROUGH THE FIRST 24 HOURS
AS A STARTING POINT...PERSISTENCE FOR HIGHS TODAY AND A MODIFIED
VERSION OF THIS NIGHT/S LOWS FOR TONIGHT. FOR FRIDAY...FAVORED THE
CONSALL FOR HIGHS. DID USE A DIURNAL FROM OBS SCHEME FOR HOURLY T
GRIDS WITH SOME ADJUSTMENTS LATE TONIGHT TO ACCOUNT FOR THE INCREASE
IN CLOUDS AND SCATTERED CONVECTION. AS FOR POPS...KEPT THEM IN LINE
WITH LOW MOS GUIDANCE TODAY BEFORE ENDING UP CLOSER TO THE HIGHER MET
NUMBERS TONIGHT AND THE LOWER MAV ONES ON FRIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 300 AM EDT THU MAY 30 2013
GENERAL AGREEMENT AMONGST THE FORECAST MODELS ONCE AGAIN FOR THE
EXTENDED PERIOD OF THE FORECAST. THE GFS AND ECMWF SOLUTIONS WERE
PREFERRED FOR THIS RENDITION OF THE EXTENDED DUE TO THEIR
SIMILARITIES. THE TIMING OF THE PASSAGE OF A COLD FRONT SATURDAY
NIGHT INTO SUNDAY WAS CAPTURED WELL BY BOTH PREFERRED MODELS. THE
MODELS BOTH HAVE DEVELOPED A SLUGGISH FRONTAL PROGRESSION WHERE THE
FRONT GETS HUNG UP A BIT NORTH OF THE OHIO SATURDAY EVENING. IT
APPEARS THAT THE RIDGE THAT WILL DOMINATE THE WEATHER TODAY AND
TOMORROW WILL BE VERY SLOW TO WEAKEN AND MOVE OFF TO THE EAST. WITH
THIS IN MIND...DECIDED TO MODIFY THE FORECAST TOWARD THE SLOWER
FRONTAL PROGRESSION SEEN IN BOTH THE GFS AND ECMWF. ISOLATED SHOWERS
AND STORMS WILL BE POSSIBLE...AS A WEAK IMPULSE PUSHES ACROSS THE
OHIO VALLEY FRIDAY EVENING. ONCE THIS BIT OF ENERGY EXITS THE AREA
FRIDAY NIGHT...THERE SHOULD ANOTHER LULL IN THE PRECIPITATION...AS
HIGH PRESSURE BECOMES REESTABLISHED ACROSS THE AREA DURING THE DAY
ON SATURDAY. ONCE THE RIDGE FINALLY BREAKS DOWN AND MOVES OFF TO THE
EAST...A COLD FRONT WILL PUSH ACROSS THE OHIO AND TENNESSEE VALLEYS
SATURDAY NIGHT THROUGH SUNDAY NIGHT. WIDESPREAD SHOWERS AND STORMS
ARE LIKELY TO ERUPT ALONG AND JUST IN ADVANCE OF THIS BOUNDARY...AS
MOIST AIR FROM THE GULF OF MEXICO POURS INTO THE AREA ON
SOUTHWESTERLY AND SOUTHERLY WINDS. THE LATEST FORECAST SOUNDINGS
WERE SHOWING MUCH BETTER INSTABILITY AND WIND SHEAR DURING THE DAY
ON SUNDAY...PARTICULARLY DURING THE AFTERNOON AND EVENING HOURS.
WITH CONDITIONS A BIT MORE JUICY AND ENERGETIC...THE POSSIBILITY FOR
A FEW STRONG STORMS WILL EXIST ON SUNDAY...WITH STRONG WINDS AND
HAIL POSSIBLE. THE SOUNDINGS ALSO ARE SHOWING THE POTENTIAL FOR
LOCALLY HEAVY RAINFALL...SO THIS WILL PRESENT THE POSSIBILITY OF
LOCALIZED HYDROLOGY ISSUES WITH THE STRONGER STORMS OR WHERE SHOWERS
AND STORM MOVE REPEATEDLY ACROSS THE SAME AREAS. WITH THE MODELS
BEING IN GOOD AGREEMENT...AND THE MODELS SHOWING FAVORABLE
CONDITIONS FOR SHOWERS AND STORMS TO FORM...WENT VERY CLOSE TO THE
MEXMOS POPS FOR SATURDAY NIGHT AND SUNDAY.
THE PERIOD WILL BEGIN WITH WELL ABOVE NORMAL TEMPERATURES...AS
SOUTHERLY FLOW AHEAD OF THE APPROACHING FRONT BRINGS WARM MOIST AIR
INTO THE AREA IN LARGE QUANTITIES. AFTER THE FRONT PASSES THROUGH
THE AREA LATE SUNDAY NIGHT...A MUCH COOLER AIR MASS WILL FILTER INTO
THE AREA...PAVING THE WAY FOR NORMAL TEMPERATURES MONDAY AND
TUESDAY. HIGHS EACH DAY WILL TOP OUT IN THE MID 70S. TEMPERATURES ON
SUNDAY WILL ALSO BE AROUND NORMAL DUE TO THE INFLUENCE OF
PRECIPITATION AND CLOUD COVER. ANOTHER RIDGE OF HIGH PRESSURE WILL
THEN SETTLE OVER THE REGION ON TUESDAY WEDNESDAY...BRINGING COOLER
AND DRIER WEATHER TO EASTERN KENTUCKY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 755 AM EDT THU MAY 30 2013
VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE END OF THE PERIOD
AT ALL THREE TAF SITES. SOME SCT CU IN THE 5 TO 7K FT RANGE ALONG
WITH HIGH CLOUDS WILL LIKELY WORK THEIR WAY BACK IN ACROSS THE
WESTERN TAF SITES DURING THE MORNING AS HIGHER 850MB MOISTURE
ADVECTS IN ALONG WITH DIURNAL HEATING TAKING EFFECT. BY MIDDAY...
EXPECT ENOUGH CLOUDS AROUND 5-7K FEET TO GO WITH BKN CIGS INTO EARLY
EVENING ACROSS THE AREA BEFORE TEMPORARILY SCATTERING OUT. THE
APPROACH OF A MID LEVEL SHORT WAVE LOOKS TO BE ENOUGH TO GENERATE A
BATCH OF SHOWERS AND THUNDERSTORMS TOWARD DAWN...HAVE ADDED A VCTS
FOR THIS TO ALL THE TAFS. WINDS THROUGH THE PERIOD WILL BE RATHER
LIGHT WITH PEAK SPEEDS OCCURRING AROUND MID AFTERNOON AT NEAR 10 KTS
FROM THE SOUTH.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SBH
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
524 AM CDT THU MAY 30 2013
.UPDATE...
12Z AVIATION DISCUSSION ADDED BELOW.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 353 AM CDT THU MAY 30 2013
A VERY ACTIVE SHORT TERM IS IN STORE AS A POTENT UPPER WAVE WORKS
ACROSS THE NATIONS MIDSECTION. H5 RAP ANALYSIS SHOWS A CLOSED LOW
HAS DEVELOPED NEAR THE BLACK HILLS THIS MORNING...WITH A NEGATIVELY
TITLED TROUGH EXTENDING FROM THERE DOWN TO NORTHEAST TEXAS. THE
RADAR MOSAIC WEDNESDAY WAS CRAMMED FULL OF CONVECTION FROM HERE ALL
THE WAY DOWN TO TEXAS...WHICH MEANS WITHIN THIS LARGE SCALE TROUGH
THERE ARE NUMEROUS LEFT OVER WAVES/MCVS. ONE SUCH WAVE IS OVER SW IA
THAT WILL SWING THROUGH HERE IN THE LATE MORNING. THE MAIN SYNOPTIC
UPPER WAVE WILL BEGIN WORKING ACROSS MN THIS AFTERNOON AND EVENING.
TO GO ALONG WITH ALL OF THE WAVES...A 50 KT LLJ IS CURRENTLY BLOWING
ACROSS MN. THIS LLJ WILL SLOWLY DIMINISH THROUGH THE MORNING...BUT A
MUCH STRONGER PUSH CURRENTLY OVER OK/KS WILL COME UP INTO SE MN/WRN
WI THIS AFTERNOON/EVENING WITH THE PRIMARY SYNOPTIC WAVE.
AT THE SFC...A 995 MB SFC LOW CAN BE FOUND NEAR PIERRE SOUTH
DAKOTA...WITH A WARM FRONT SITTING ACROSS CENTRAL MN. DURING THE
SHORT TERM...THIS LOW WILL BECOME OCCLUDED AND SLOWLY MEANDER NORTH
INTO NODAK. THE WARM FRONT WILL CONTINUE TO MOVE NORTH
TODAY...EVENTUALLY SETTLING ALONG THE INTERNATIONAL BORDER. BACK TO
THE WEST...A COLD FRONT MOVING ACROSS SODAK TODAY WILL BE ENTERING
WRN MN BY THE END OF THE PERIOD.
FOR TODAY...EXPECT A BRIEF LULL IN ACTIVITY THIS MORNING AS WE WAIT
FOR THE WAVE OVER SW IA TO GET HERE AROUND 15Z. FORECAST SOUNDINGS
ACROSS THE ENTIRE CWA SHOW VERY LITTLE IF ANY CAPPING...SO EXPECT
SHOWERS AND STORMS TO DEVELOP QUICKLY THIS MORNING ONCE A LITTLE
DAYTIME HEATING KICKS IN. SINCE WE WILL NOT BE ABLE TO BUILD MUCH
INSTABILITY THANKS TO DENSE CLOUD COVER AND THE FACT THAT ONCE A
LITTLE DEVELOPS THE ATMO WILL QUICKLY CONSUME IT...THE SEVERE THREAT
LOOKS FAIRLY LOW TODAY. FOR SEVERE WEATHER...WILL HAVE TO WATCH THAT
SECOND LLJ WORKING UP IN THE AFTERNOON. BY 00Z THE RAP HAS 50 KT
WINDS AT H85 UP INTO OUR WI CWA. LIKE YESTERDAY...THIS COULD LEAD TO
THE THREAT FOR BOWING LINE SEGMENTS AND DAMAGING WINDS.
AS FOR ANY HYDROLOGY ISSUES TODAY...THE ONLY AREA THAT WILL
PROBABLY HAVE TO BE WATCHED IS THE EAU CLAIRE AREA. THEY SET A DAILY
RAINFALL RECORD YESTERDAY AND WILL BE UNDER THE GUN FOR THE SECOND
LLJ SURGE THIS AFTERNOON...WITH THE POTENTIAL FOR SOME TRAINING OF
STORMS THIS AFTERNOON AND EVENING.
TONIGHT...THE COLD FRONT WILL START ENTERING WRN MN WHILE THE LLJ
WORKS INTO CENTRAL/ERN WI. THIS SHOULD MOVE THE HEAVY RAIN THREAT
EAST OF THE MPX CWA TONIGHT. HOWEVER...HI-RES CAMS SHOW SCT RETURNS
CONTINUING THROUGH THE NIGHT AHEAD OF THE FRONT...SO HAVE POPS
SLOWLY RAMPING DOWN FROM LIKELIES TO START THE EVENING...DOWN TO 50%
POPS OR LESS BY 12Z FRIDAY.
FOR TEMPERATURES...GIVEN ALL OF THE CLOUD COVER...IT WILL NOT BE AN
OVERLY WARM WARM SECTOR TODAY...WITH HIGHS LIKELY STAYING IN THE MID
TO UPPER 70S...DESPITE H85 TEMPS BEING UP AROUND +15C. FOR
TONIGHT...MIXED LAYER DEWPS ON THE NAM DROP INTO THE 40S BEHIND THE
FRONT...SO LOWS IN THE WRN CWA COULD END UP BEING A FEW DEGREES
COOLER THAN WHAT IS CURRENTLY INDICATED.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 353 AM CDT THU MAY 30 2013
MODELS INDICATE RATHER STRONG TROUGH AXIS WORKING THROUGH THE
AREA BY FRIDAY MORNING. THIS SHOULD WORK MUCH OF THE RAIN AND
THUNDER TO THE NORTH AND EAST OF THE AREA LATE THURSDAY NIGHT.
THIS SHOULD WORK A DRY SLOT NORTHEAST INTO SOUTHWEST PORTION OF
THE CWA DURING FRIDAY MORNING. THE UPPER CIRCULATION THEN MOVES A
FRONTAL BOUNDARY EAST ACROSS EASTERN HALF OF THE CWA FRIDAY
AFTERNOON. THE DETERMINISTIC MODELS ARE INDICATING MODEST
DESTABILIZATION ACROSS THE EASTERN HALF OF THE AREA...WITH ML
MUCAPE INCREASING TO 1500/2000 J/KG. SHEAR INCREASES INTO THE
AFTERNOON...ESPECIALLY INTO WESTERN WISCONSIN. THE ONLY INHIBITING
FACTOR FOR CONVECTIVE INITIATION ALONG THE FRONT APPEARS TO BE
RATHER WEAK SURFACE CONVERGENCE..WITH WINDS S-SW ALONG THE
BOUNDARY. THE HIRES MODELS ARE SHOWING RATHER ROBUST CONVECTION
DEVELOPING ALONG THE BOUNDARY AS IT MOVES INTO EASTERN MINNESOTA
FRIDAY AFTERNOON. WILL HAVE TO MONITOR THIS SITUATION INTO
FRIDAY...AS SEVERE WEATHER THREAT IS FORECAST TO BE LOW AT THIS
TIME.
FRONT EXITS TO THE EAST FRIDAY NIGHT TAKING THE HEAVY CONVECTIVE
POTENTIAL WITH IT. THIS WILL LEAVE THE UPPER LOW OVER THE AREA
THROUGH AT LEAST SATURDAY. SHOWERS LOOK TO BE A FAIR BET
ESPECIALLY LATER IN THE DAY AS THE LOW MOVES EAST. WITH ABUNDANT
CLOUD COVER...WILL BE LITTLE IN THE WAY OF HEATING...SO CONVECTIVE
POTENTIAL IS LOW. CLEARING SHOULD MOVE INTO THE AREA LATER
SATURDAY NIGHT...AND SUNDAY LOOKS LIKE THE BEST DAY OF THE
WEEKEND...WITH SUNSHINE AND MILD TEMPERATURES.
THE EXTENDED PORTION OF THE FORECAST STARTS OFF RATHER
COOL...ESPECIALLY OVER THE EASTERN CWA MONDAY MORNING. THERE MAY
EVEN BE A FROST POTENTIAL OVER A PORTION OF WEST CENTRAL
WISCONSIN. THE NEXT WEATHER SYSTEM MOVES INTO THE AREA LATER
MONDAY WITH SOME SHOWERS INTO THE WESTERN CWA. THE 00Z GFS AND
ECMWF DIVERGE SOMEWHAT ON THE OVERALL EVOLUTION AND MOVEMENT OF
THE NEXT LOW PRESSURE SYSTEM THAT MOVES ACROSS THE NORTHERN STATES
THROUGH MUCH OF NEXT WEEK. IT DOES APPEAR THE THREAT OF MORE
SHOWERS AND THUNDERSTORMS RETURNS BY MIDWEEK...WITH TEMPERATURES
REMAINING BELOW NORMAL THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 523 AM CDT THU MAY 30 2013
ALL SIGNS POINT TO ANOTHER ACTIVE DAY AS THE MPX AREAS SITS IN A
MOIST...UNSTABLE...AND WEAKLY CAPPED ENVIRONMENT. THERE IS NO REAL
FOCUSING MECHANISM FOR STORMS TODAY...INSTEAD...EXPECT CONVECTION
TO QUICKLY DEVELOP ONCE WE GET A LITTLE INSTABILITY...AS THE
HRRR SHOWS HAPPENING RAPIDLY AFTER 15Z. DID ADD SOME TEMPO GROUPS
FOR THUNDER EARLY THIS AFTERNOON...BUT COULD CERTAINLY SEE A
COUPLE ROUNDS OF STORMS THROUGH THE EVENING...ESPECIALLY FOR MSP
AND WI TERMINALS. TONIGHT...A COLD FRONT WILL MOVE INTO WRN
MN...THOUGH IT ONLY LOOKS TO GET THROUGH RWF BY 12Z. BEING EAST OF
THE FRONT STILL TONIGHT...EXPECT A SIMILAR TREND IN SHRA/TSRA
ACTIVITY AS TO WHAT WAS SEEN LAST NIGHT. FOR CIGS...BEING MAINLY
SOUTH OF THE WARM FRONT...EXPECT SPORADIC IFR/MVFR CIGS TO QUICKLY
LIFT THIS MORNING...WITH VFR CIGS REMAINING OUTSIDE OF TSRA.
DEPENDING HOW MUCH RAIN IS SEEN IN WI...MAY SEE MVFR CIGS RETURN
THERE TONIGHT...BUT NOT OVERLY CONFIDENT ON THAT HAPPENING AT THE
MOMENT.
KMSP...HIGH CONFIDENCE IN STORMS OCCURRING TODAY...BUT WITH NO
DEFINITIVE FRONT COMING THROUGH...CONFIDENCE IS LOW ON EXACT
TIMING...OR EVEN EXACT NUMBER OF STORMS MSP WILL SEE TODAY INTO
TONIGHT. FOR NOW...INSERTED A TEMPO GROUP FROM 18Z TO 21Z PER
CONVECTIVE COVERAGE ON THE HRRR. WITH THE FRONT NEVER GETTING
THROUGH THE FIELD THIS PERIOD...MAY SEE PERIODS OF SHOWERS THROUGH
THE NIGHT...THOUGH EXPECT SHRA/TSRA ACTIVITY TO DECREASE
CONSIDERABLY AFTER SUNSET. BY 18Z FRIDAY OR SHORTLY AFTER...WILL
HAVE TO START THINKING ABOUT THE NEXT POTENTIAL ROUND OF TSRA.
/OUTLOOK FOR KMSP/
FRI...SCT MVFR CIGS. SHRA/TSRA LIKELY. WINDS SW 10-15 KTS.
SAT...MVFR CIGS POSSIBLE. SHRA LIKELY. WINDS WNW 5-10 KTS.
SUN...MVFR CIGS POSSIBLE EARLY. WINDS N 5 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...DWE
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
1044 AM CDT THU MAY 30 2013
.SHORT TERM...(THROUGH LATE TONIGHT)
ISSUED AT 1044 AM CDT THU MAY 30 2013
COMPLICATED FORECAST FOR THE REST OF THE DAY AS AREA OF SHOWERS/
THUNDERSTORMS ARE MOVING VERY SLOWLY EASTWARD LATE THIS MORNING.
THIS IS AHEAD OF THE NEGATIVELY TILTED TROUGH CURRENTLY OVER THE
CENTRAL PLAINS THAT THE RAP LIFTS INTO MO/IL THIS EVENING. LAST
FEW RUNS OF THE HRRR SUPPORTS THAT THE WESTERN MO COMPLEX WILL
MOVE NORTHEASTWARD INTO THE CWA BY LATE THIS AFTERNOON/EARLY THIS
EVENING. IN ADDITION...SCATTERED THUNDERSTORMS HAVE RECENTLY
DEVELOPED OVER SOUTH CENTRAL MO THAT ARE LIFTING NORTHEASTWARD.
THESE TRENDS SUPPORT GOING FORECAST THAT PRECIPITATION CHANCES
WILL INCREASE THROUGH THE AFTERNOON. MLCAPES ARE CURRENTLY
1000-1500 J/K AND SHOULD INCREASE IN THE WARM SECTOR AS
TEMPERATURES CLIMB INTO THE LOWER-MID 80S. 0-6KM SHEAR WILL BE
RELATIVELY WEAK WHICH FAVORS MULTICELL STORMS...THOUGH INCREASING
INSTABILITY AND LARGE SCALE LIFT SUGGEST THAT THERE MAY BE A FEW
SEVERE STORMS CAPABLE OF PRODUCING SOME LARGE HAIL AND DAMAGING
WIND GUSTS THROUGH THIS EVENING. THE LOW LEVEL JET WILL REMAIN
40-50KTS TODAY...SO CANNOT RULE OUT A TORNADO OR TWO IN THE STRONGEST
STORMS. LATEST RADAR IMAGERY HAS SHOWN THE TENDENCY FOR CELLS TO
TRAIN...SO HEAVY RAINFALL DOES LOOK LIKE A REAL THREAT GIVEN PWATS
AROUND 1.8 INCHES.
BRITT
.LONG TERM...(TONIGHT THROUGH WEDNESDAY)
ISSUED AT 343 AM CDT THU MAY 30 2013
(TONIGHT THROUGH SATURDAY NIGHT)
PCPN CHANCES INCREASE TONIGHT AS NEXT IN SERIES OF MCS/S DEVELOPS OVER
WESTERN MO AND SLIDES EAST THROUGH FORECAST AREA...WITH BEST
CHANCES OF HEAVY RAIN ALONG AND NORTH OF I-70. SINCE THIS AREA HAS
HAD QUITE A BIT OF RAIN OVER THE PAST WEEK AND SOILS REMAIN
SATURATED...HAVE ISSUED A FLASH FLOOD WATCH FROM 18Z TODAY THROUGH
12Z SATURDAY. LOWS TONIGHT TO REMAIN MILD...IN THE MID 60S TO LOW
70S.
FOR FRIDAY...A LOT WILL DEPEND ON HOW SOON THIS AREA OF STORMS
WEAKENS/EXITS FORECAST AREA...ON WHAT WILL DEVELOP FOR THE AFTERNOON
AND EVENING HOURS. IF ATMOSPHERE GETS WORKED OVER...IT WILL TAKE A
LOT FOR IT TO RECOVER. FOR NOW...WILL ERR ON THE SIDE OF CAUTION
WITH STORMS REDEVELOPING BY THE AFTERNOON HOURS AS NEXT SHORTWAVE
SLIDES THROUGH. WITH DECENT INSTABILITY...MID LEVEL LAPSE RATES AND
STRENGTHENING LOW LEVEL JET...WILL SEE A CHANCE FOR SEVERE WEATHER
ONCE AGAIN FRIDAY AFTERNOON AND OVERNIGHT. ANOTHER ROUND OF HEAVY RAIN
IS POSSIBLE AS WELL...WHICH WILL EVENTUALLY SHIFT TO THE SOUTH WITH
TIME. SO MAY NEED TO EXTEND FLASH FLOOD WATCH TO INCLUDE REST OF
FORECAST AREA.
MAIN COLD FRONT TO FINALLY MOVE THROUGH THE AREA DURING THE DAY ON
SATURDAY WITH LAST IN A SERIES OF SHORTWAVES SLIDING THROUGH...SO
PCPN TO TAPER OFF BY SATURDAY EVENING.
(SUNDAY THROUGH NEXT WEDNESDAY)
COOLER AND DRIER WEATHER IS IN STORE FOR THE LAST PART OF THE
WEEKEND AND INTO EARLY NEXT WEEK. HIGHS WILL BE IN THE UPPER 60S TO
MID 70S SUNDAY THROUGH TUESDAY. THEN NEXT WEATHER SYSTEM TO APPROACH
THE REGION BY MID WEEK WITH NEXT CHANCE FOR SHOWERS AND
THUNDERSTORMS BEGINNING TUESDAY NIGHT.
BYRD
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 641 AM CDT THU MAY 30 2013
COMPLEX FORECAST FOR THIS TAF PERIOD WITH POTENTIAL FOR PROLONGED
PERIODS OF THUNDER. IN THE NEAR TERM THERE ARE TWO MAIN AREAS WITH
POTENTIAL IMPACTS. THE FIRST IS A SMALL NEWD MOVING CLUSTER OF
SHOWERS AND THUNDERSTORMS WHICH MAY IMPACT KUIN BETWEEN
1230-1400Z. THE OTHER LESS OBVIOUS IS AN AREA OF SHOWERS S/SW OF
ST LOUIS...WHICH THE MODELS INTENSIFY IN THE 13-16Z TIME FRAME AND
MOVE INTO THE ST LOUIS AREA. AFTER 16Z THE TRENDS IN SHOWERS AND
THUNDERSTORMS ARE DIFFICULT TO PINPOINT. SOMEWHERE IN THE 19-21Z
TIME FRAME SEVERAL LINES/CLUSTERS OF THUNDERSTORMS ARE EXPECTED TO
DEVELOP AND IMPACT KUIN AND KCOU THRU 01-02Z...WITH THIS ACTIVITY
SPREADING INTO THE ST LOUIS AREA BETWEEN 23-01Z. THEN DURING THE
OVERNIGHT HOURS ANOTHER CLUSTER OF THUNDERSTORMS IS EXPECTED TO
DEVELOP IN ERN KS/WRN MO AND MOVE EWD AFFECTING KCOU AROUND 10Z
AND ST LOUIS BETWEEN 12-16Z ON FRIDAY. GUSTY SOUTHERLY WINDS ARE
EXPECTED TODAY INTO EARLY EVENING.
SPECIFICS FOR KSTL...
COMPLEX FORECAST FOR THIS TAF PERIOD WITH POTENTIAL FOR PROLONGED
PERIODS OF THUNDER. AN AREA OF SHOWERS S/SW OF ST LOUIS IS
FORECAST TO INTENSIFY IN THE 13-16Z TIME FRAME AND MOVE INTO THE
ST LOUIS AREA. AFTER 16Z THE TRENDS IN SHOWERS AND THUNDERSTORMS
ARE DIFFICULT TO PINPOINT. SOMEWHERE IN THE 23-01Z TIME FRAME
SEVERAL LINES/CLUSTERS OF THUNDERSTORMS ARE EXPECTED TO DEVELOP
AND/OR MOVE INTO THE TERMINAL. THIS ACTIVITY COULD PERSIST UNTIL
05Z WITH A BREAK UNTIL ANOTHER CLUSTER OF STORMS IMPACTS KSTL BETWEEN
12-16Z ON FRIDAY. GUSTY SOUTHERLY WINDS ARE EXPECTED TODAY INTO
EARLY EVENING.
GLASS
&&
.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...UPDATED
NWS ALBUQUERQUE NM
536 AM MDT THU MAY 30 2013
.AVIATION...
12Z TAF CYCLE
AREA TO REMAIN UNDER THE INFLUENCE OF A FAST WEST-NORTHWEST FLOW
ALOFT THROUGH AT LEAST 12Z FRI. AXIS OF STRONG UPPER JET LOCATED
JUST NORTH OF THE STATE BUT IN A FAVORABLE POSITION AND
ORIENTATION TO GENERATE MOUNTAIN WAVES AND ASSOCIATED IMPACTS OVER
THE NORTHERN MOUNTAINS AND ESPECIALLY THE SANGRE DE CRISTO AND
IMMEDIATE EAST SLOPES. SFC WINDS GUSTS FREQUENTLY IN THE 30-35 KT
RANGE EXPECTED FOR ALL TERMINAL SITES EXCEPT KROW WHERE SOMEWHAT
LIGHTER WIND CONDITIONS EXPECTED AS COMPARED TO CENTRAL AND
NORTHERN AREAS OF THE STATE. AREAS OF BLOWING DUST EXPECTED TO
RESULT IN REDUCED VSBY TO 5SM OR LESS AT TIMES...ESPECIALLY LOWER
ELEVATIONS CENTRAL AND EAST. SIGNIFICANT CLOUD COVER IS NOT
EXPECTED ALTHOUGH BRIEF BKN120 SKY CONDITIONS MAY BE ENCOUNTERED
ACROSS THE FAR NORTH. KJ
&&
.PREV DISCUSSION...325 AM MDT THU MAY 30 2013...
DRYLINE HAS SO FAR STAYED TO THE EAST OF NEW MEXICO THIS MORNING AND
ALTHOUGH IT/S FAIRLY CLOSE TO HOBBS DON/T EXPECT IT TO GET MUCH
FARTHER WEST IF AT ALL. IN THE NORTHEAST DEWPOINTS HAVE COME UP AS
THE SFC LOW SHIFTED INTO THE TX/OK PANHANDLES BUT THIS INCREASE
LIKELY WON/T LAST LONG WITH THE RUC FORECASTING A WEAK SFC LOW TO
REDEVELOP OVER SE CO BY MIDDAY. MODELS ALSO SHOW CURRENT BATCH OF
MID LEVEL MOISTURE EXITING BY MIDDAY. UPPER JET TO RETREAT NWD TODAY
BUT WILL BE STRETCHED OVER FAR NRN NM AND COLORADO...COMBINED WITH
THE SFC LOW PLACEMENT WILL HAVE LOW END WIND ADVY OVER SOME OF THE
NORTH CENTRAL/NORTHEAST SOUTH TO CLINES CORNERS.
DRY INTO FRIDAY NIGHT. ANOTHER WINDY DAY ON FRIDAY WITH CRITICAL
FIRE WX CONDITIONS POSSIBLE. ANOTHER BATCH OF MID LEVEL MOISTURE
PASSES OVERHEAD TONIGHT AND FRIDAY BUT ANYTHING MORE THAN A FEW
SPRINKLES OUT OF IT...IF THAT...WOULD BE A SURPRISE.
SURFACE FRONT PUSHES THROUGH FRIDAY NIGHT WITH THE BACK DOOR FRONT
INTO THE EAST SATURDAY. LOW LEVEL MOISTURE APPEARS TO MOVE IN FROM
THE SOUTH AND SOUTHEAST WITH INCREASING INSTAB SO WENT AHEAD AND
SPREAD SOME SMALL POPS FROM THE EAST SLOPES OF THE SOUTH CENTRAL
MOUNTAIN ACROSS CHAVES COUNTY AND NORTHEAST ALONG THE TX BORDER
SATURDAY AFTERNOON ALTHOUGH FOR NOW BEST CONFIDENCE IS IN THE
SOUTHEAST. ANOTHER BLOB OF MID LEVEL MOISTURE TO MIGRATE OVER THE
SOUTHERN HALF OF THE STATE AND COULD NOT RULE OUT A FEW SPRINKLES
UNDERNEATH IT...BUT LEFT MENTION OUT OF FCST FOR NOW. IN FACT THE
ADJMET GUIDANCE DOES PAINT SOME LOW POPS OVER THE SOUTHWEST MTS.
INCREASED POPS SOMEWHAT SUNDAY ESPECIALLY ALONG THE CENTRAL MT
CHAIN. LEFT THE MENTION OF DRY CONVECTION FROM THE RGV WWD ALTHOUGH
COULD BE A MIX WITH AT LEAST SOME MEAGER MEASURABLE PCPN DEPENDING
IF THE SURGE IS AS STRONG AS DEPICTED SO FAR. HOWEVER...MONDAY
STARTS TO DRY OUT AND TUESDAY EVEN MORE SO. REMOVED THE POPS IN THE
EAST FOR TUESDAY NIGHT...AND PROBABLY SHOULD HAVE FOR TUESDAY AS
WELL AS RIGHT NOW IT LOOKS DRY. ANOTHER BACKDOOR FRONT WEDNESDAY
LOOKS TO PUSH INTO THE RGV WEDNESDAY NIGHT...SO POPS/WX GRIDS FOR
MID TO LATE WEEK HAVE BEEN UPDATED.
.FIRE WEATHER...
...WIDESPREAD CRITICAL FIRE WEATHER CONDITIONS DUE TO STRONG WIND
AND LOW HUMIDITY FOR MUCH OF NORTHERN AND CENTRAL NEW MEXICO THROUGH
FRIDAY...
...DRY LIGHTNING THREAT INCREASING SUNDAY CENTRAL/WEST...
MOVING INTO DAY 2 OF A PROTRACTED CRITICAL FIRE WEATHER PATTERN THAT
WILL EXTEND THROUGH FRIDAY. THEREAFTER...FAR LESS WIND BUT GROWING
CONFIDENCE IN A SUBSTANTIAL WESTERLY PUSH OF LOWER LEVEL MOISTURE
THAT WILL RESULT IN A SIGNIFICANT DRY LIGHTNING THREAT FOR
CENTRAL/WESTERN AREAS BY SUNDAY.
SATURDAY LOOKS TO BE A CLASSIC TRANSITION DAY AS RICHER LOW LEVEL
MOISTURE INITIALLY MAKES A RETURN TO THE EC/SE PLAINS AS SURFACE
WINDS VEER TO SELY AND TAPS INTO A NOW SEMI-PERMANENT POOL OF
GULFMEX MOISTURE. POTENTIAL FOR SOME DRIER STORMS ALONG THE EAST
SLOPES OF THE CENTRAL/SC MOUNTAIN SATURDAY PM. HIGHER DEW POINT AIR
ALSO CREEPING NORTHWARD ALONG THE RGV AND THAT COUPLED WITH A SUBTLE
AND ALWAYS SNEAKY UPTICK IN MID-LEVEL MOISTURE AS THE UPPER RIDGE
EXPANDS/BUILDS NORTHWARD COULD RESULT IN AT LEAST AN ISOLATED DRY
LIGHTNING THREAT OVER THE WC/SW HIGHER TERRAIN AS EARLY AS SATURDAY
AFTERNOON OR EVENING. THIS WILL BE CLOSELY MONITORED.
EVEN THE SLIGHTEST UPTICK IN LOWER/MID LEVEL MOISTURE IN THE
PRESENCE OF VERY STEEP LAPSE RATES THAT ARE TYPICAL OF THE
DEVELOPING PATTERN THIS WEEKEND SEEMS TO RESULT IN MORE THAN
EXPECTED BUILDUPS/VIRGA AND DRY CG/S. WE SHALL SEE. SUNDAY
AFTERNOON/EVENING LOOKING TO BE THE MORE CRITICAL DAY WITH RESPECT
TO DRY LIGHTNING FOR THE WEST THOUGH MONDAY COULD BE FAIRLY ACTIVE
EAST OF THE DIVIDE TO THE EAST SLOPES OF THE CENTRAL MOUNTAIN
CHAIN AS DRIER AIR ADVANCES EASTWARD.
IN THE MEANTIME...LARGE-SCALE UPPER TROUGH SLOWLY PIVOTING NORTHEAST
FROM THE CENTRAL/NORTHERN ROCKIES EARLY THIS MORNING. BASE OF THE
TROUGH TRANSLATED EASTWARD OVER OUR AREA THIS PAST NIGHT AND PRESENT
INDICATIONS ARE THAT THE STRONGEST MID-LEVEL WINDS WILL PASS
OVERHEAD BEFORE MIDDAY. THAT SAID...AN ANOMALOUSLY STRONG UPPER
LEVEL JET ORIENTED NW TO SE FROM THE GREAT BASIN TO THE FOUR CORNERS
REGION WILL NOT SHIFT NORTHWARD APPRECIABLY TODAY. AS A
RESULT...WIND SPEEDS THOUGH A BIT LESS THAN YESTERDAY WILL STILL BE
SIGNIFICANT WITH FREQUENT GUSTS OF 35-40 MPH ACROSS THE NORTH.
SURFACE LOW NOT AS FAVORABLE EITHER. NO CHANGES TO THE FIRE
WEATHER WATCH FOR FRIDAY THOUGH BELT OF STRONGEST WINDS DO SHIFT
SOUTHWARD PER PREVIOUS FORECAST. VERY DEEP MIXING CONTINUES TODAY
BEFORE MAX MIXING HEIGHTS TREND DOWNWARD SLIGHTLY ON FRIDAY. LOWEST
RH VALUES CENTRAL VALLEY CORRIDOR AND IN THE EAST.
EXTENDED MODELS STILL TRENDING DRIER/BREEZIER EARLY NEXT WORK WEEK
FOLLOWING OUR LIGHTNING PERIOD. BACK TO VERY DEEP MIXING AND GUSTY
AFTERNOON/EVENING PERIODS THOUGH TOO EARLY TO GAUGE STRENGTH OF ANY
SUSTAINED WINDY PERIODS. KJ
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 11 AM THIS MORNING TO 8 PM MDT THIS EVENING
FOR THE FOLLOWING ZONES...NMZ101>104-106>108.
FIRE WEATHER WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING FOR
THE FOLLOWING ZONES...NMZ101>108.
WIND ADVISORY FROM 10 AM THIS MORNING TO 9 PM MDT THIS EVENING FOR
THE FOLLOWING ZONES...NMZ510>516-523-527>529.
&&
$$
41
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1000 AM CDT THU MAY 30 2013
.UPDATE...
ISSUED AT 1000 AM CDT THU MAY 30 2013
MORNING UPDATE FOCUSES ON FLOODING IN CLAY COUNTY MINNESOTA AND
POP TRENDS. RADAR CONTINUES TO SHOW A BAND OF SHOWERS ACROSS
NORTHWESTERN ZONES. INCREASED POPS IN THIS REGION AND DECREASED
POPS ACROSS THE SOUTHERN HALF OF THE CWA. HRRR DOES SHOW
REDEVELOPMENT OVER SOUTHEASTERN ZONES SO MAINTAINED
LIKELIES...HOWEVER WENT DOWN TO 30 POPS FOR SOUTHEASTERN ND AND
SOUTHERN VALLEY. WILL WAIT TO FURTHER ASSESS 12Z RUN BEFORE
CHANGING ANYTHING BEYOND 00Z FRIDAY. REPORTS OF FIVE TO SEVEN
INCHES ARE COMING IN ALONG THE BUFFALO RIVER BASIN TO INCLUDE THE
CITIES OF AVERILL AND DILWORTH. WILL EXTEND WARNING AREA IN TIME
BUT CHOP OFF CASS COUNTY AND NORMAN COUNTY...WHERE RADAR ESTIMATES
ARE ABOUT FOUR INCHES OR LESS WITH NO REPORTS OF OVERLAND FLOODING
FROM THOSE COUNTY MANAGERS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 355 AM CDT THU MAY 30 2013
THE MAIN CHALLENGE WILL BE SHOWER AND THUNDERSTORM CHANCES INTO
FRIDAY AND HEAVY RAIN POTENTIAL. THE MODELS ARE IN GOOD OVERALL
AGREEMENT BUT NOT PICKING UP TOO WELL ON MESOSCALE FEATURES.
FOR TODAY AND TONIGHT...EXPECT SHOWERS AND STORMS TO LIFT TO THE NORTH
AND LIKELY BECOME MORE FOCUSED IN THE NORTHERN AREAS. THERE WILL
BE A CHANCE FOR LOCALLY HEAVY RAINFALL NEAR ANY STORMS...GIVEN
PWATS OVER 1.5 INCHES. THERE COULD BE SOME STRONGER STORMS THIS
AFTERNOON IF SFC HEATING OCCURS...BUT I AGREE WITH SPC IN KEEPING
JUST 5% PROBS FOR HAIL/WIND AND NO SLIGHT RISK AT THIS TIME. THINK
THE MAIN ISSUE COULD BE HEAVY RAIN IF TRAINING ECHOES DEVELOPS.
HARD TO PINPOINT WHERE THIS MAY OCCUR...SO NO FLOOD HEADLINES
PLANNED...ALTHOUGH THERE COULD BE MORE FLOODING ISSUES NEAR
PERSISTENT HEAVY RAIN TODAY AND TONIGHT.
FOR FRIDAY...THE UPPER LOW WILL SLOWLY MOVE INTO THE AREA FROM THE
WEST AND EXPECT MORE WRAPAROUND SHOWERS AND SOME THUNDER. AGAIN
LOCALLY HEAVY RAINFALL IS POSSIBLE NEAR STRONGER SHOWERS AND
STORMS. IT WILL BE COOLER THAN TODAY WITH WINDS SHIFTING TO THE
NORTH BY AFTERNOON IN ALL BUT THE SOUTH AND EASTERN AREAS.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU MAY 30 2013
FOR FRI NIGHT INTO SAT...WRAPAROUND SHOWERS WILL CONTINUE BEFORE
IT DRIES OUT BY SAT AFTERNOON.
FOR SUNDAY THROUGH WEDNESDAY...EXPECT A LOW AMPLITUDE LONG WAVE
TROUGH OVER THE NORTHERN PLAINS TO SHIFT EAST. ECMWF AND GFS
GENERALLY AGREE TIMING WISE HOWEVER THE GFS IS A HIGHER AMPLITUDE
SOLUTION COMPARED TO THE ECMWF. WILL BLEND THE MODELS.
ECMWF HAS SLOWED DOWN FROM MODEL RUN TO MODEL RUN WHILE THE GFS HAS
SHIFTED PRECIP SOUTH WITH EACH RUN. WILL SLOW DOWN PRECIP FOR TUE AND
DECREASE POPS A BIT FOR MON AND MON NIGHT.
LITTLE CHANGE TO TEMPS FOR SUN THROUGH TUE. WED HIGH TEMP WAS
INCREASED BY 3 DEGREES IN THE NORTHWEST ZONES AND A DEGREE OR TWO
LOWER IN THE SOUTHERN ZONES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 1000 AM CDT THU MAY 30 2013
IFR TO MVFR CIGS WILL CONTINUE ACROSS MOST OF THE REGION THIS
MORNING...WITH SLOW IMPROVEMENT TO MVFR OR VFR BY AFTERNOON. EXPECT
A SHOWER OR STORM NEARLY ANYTIME THROUGH THE PERIOD...BUT TRIED TO
INDICATE THE BEST POTENTIAL FOR RAIN.
&&
.HYDROLOGY...
ISSUED AT 355 AM CDT THU MAY 30 2013
A BAND OF HEAVY RAIN FELL OVERNIGHT FROM FARGO THROUGH
NORTHEASTERN CLAY COUNTY. THIS HAS PROMPTED AN AREAL FLOOD WARNING
FOR THE REGION. REPORTS OF OVERLAND FLOODING IN THE VICINITY OF
AVERILL AND DILWORTH HAVE PROMPTED AN EXTENSION OF WARNING THROUGH
03Z FRIDAY. HAVE REMOVED CASS COUNTY ND AND NORMAN COUNTY MN FROM
WARNING AREA.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...SPEICHER
SHORT TERM...DK
LONG TERM...HOPPES/DK
AVIATION...JR
HYDROLOGY...DK/SPEICHER
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
736 AM EDT THU MAY 30 2013
.SYNOPSIS...
HIGH PRESSURE CENTERED OVER THE ATLANTIC WILL KEEP US DRY WITH
TEMPERATURES SLIGHTLY ABOVE AVERAGE THROUGH THE END OF THE WEEK. THE
HIGH MOVES OFF THE ATLANTIC COAST OVER THE WEEKEND...AND A COLD
FRONT APPROACHES BY EARLY NEXT WEEK...RETURNING US TO AN UNSETTLED
PATTERN.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE AREAL DISTRIBUTION OF CLOUD COVER IS WORKING OUT ABOUT AS
EXPECTED...WITH OVERCAST SKIES OVER THE SRN APPALACHAINS...THE WRN
UPSTATE AND NE GA. THE MOISTURE MAY NOT BE AS SHALLOW AS I
ORIGINALLY THOUGHT AND SOME LOCATIONS IN THIS AREA MAY BE CLOUDY
THROUGH NOON. FARTHER TO THE EAST...INCLUDING THE WRN NC PIEDMONT
AND THE NE UPSTATE...THE LLVLS ARE DRIER AND IT SHOULD BE MAINLY
SUNNY EXPECT FOR SOME CIRRUS AND A FEW CU THAT WILL LIFT AN HOUR OR
TWO AFTER SUNRISE.
AS OF 440 AM EDT THURSDAY...MVFR CIGS ARE FILLING IN QUICKLY OVER NE
GA AND WE APPEAR TO BE ON TRACK FOR A STRATUS DECK TO INVADE THE
FORECAST AREA FROM THE SOUTHWEST OVER THE NEXT FEW HOURS. I DID
TWEAK SKY COVER TO ACCOUNT FOR CURRENT TRENDS...HOWEVER.
AS OF 300 AM EDT THURSDAY...MVFR LEVEL STRATUS IS EXPANDING ACROSS
SOUTHERN AND CENTRAL GA EARLY THIS THURSDAY MORNING. THE SREF SHOWS
A HIGH PROBABILITY THAT IT WILL CONTINUE TO EXPAND NORTH AND
NORTHEAST...EVENTUALLY SPREADING ACROSS NE GA...THE WRN UPSTATE AND
THE SRN NC MTNS. I/VE CARRIED MOSTLY CLOUDY SKIES EARLY IN THE DAY
TO ACCOUNT FOR THIS...BUT THE CLOUD LAYER SHOULD BE SHALLOW AND
SHOULD MIX INTO A CU FIELD FAIRLY QUICKLY BY LATE MORNING. OTHERWISE
IT WILL BE DRY ACROSS THE ENTIRE FORECAST AREA TODAY WITH MAX TEMPS
RUNNING ABOUT A CATEGORY ABOVE NORMAL.
WE WILL PROBABLY SEE STRATUS DEVELOP AGAIN TONIGHT. IN FACT...WITH
HIGHER BNDRY LAYER RH/S AND A STRONGER WIND FIELD...IT IS LIKELY TO
COVER MOST OF THE FORECAST AREA. STILL...IT/S NOT A GIVEN THAT THIS
WILL HAPPEN AND MY SKY COVER IS RATHER LOW...ESPECIALLY ACROSS WRN
NC.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 245 AM THURSDAY...UPPER RIDGE WILL BEGIN TO BREAK DOWN AND
SHIFT EAST FURTHER OFF THE ATLANTIC COAST DURING THE SHORT
TERM...BUT OVERALL WILL CONTINUE TO INFLUENCE OUR SENSIBLE WX. LLVL
FLOW WILL REMAIN LIGHT GENERALLY OUT OF THE S/SE OFF THE ATLANTIC.
MODELS IN BETTER AGREEMENT ON MORNING STRATUS DEVELOPING AND BEING A
LITTLE BIT MORE WIDESPREAD FRIDAY MORNING...BUT SHUD SCATTER OUT BY
MIDDAY. FCST SNDGS SHOW WEAK CAPE WITH INHIBITION FRI AFTN...SO
GOING WITH A DRY FCST.
ON SATURDAY...ONCE AGAIN...GUIDANCE INDICATING MORNING STRATUS
DEVELOPMENT...WITH INCREASE IN SOME MID-UPR MOISTURE AS WELL.
OVERALL...STILL LOOKS LIKE ANOTHER DRY DAY...ALTHO WILL KEEP A SLGT
CHC POP FOR THE NC MTNS...THANKS TO SOME INCREASED MOISTURE IN A
VEERING SWLY LLVL FLOW. HIGHS BOTH DAYS WILL BE SIMILAR TO LAST
COUPLE OF DAYS...ABOUT A CATEGORY OR TWO ABOVE NORMAL...WITH NEAR OR
SLIGHTLY ABOVE NORMAL OVERNIGHT LOWS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...UNSETTLED WEATHER LOOKS TO RETURN THE CWFA
FOR SUNDAY INTO EARLY NEXT WEEK.
A COLD FRONT WILL APPROACH THE AREA FROM THE WEST ON SUNDAY...WITH A
PLUME OF DEEP RH AND HEIGHT FALLS ENTERING THE NC MTNS BY PEAK
HEATING. SO A SOLID CHC TO LOW-END LIKELY POPS FOR SUNDAY LOOKS
GOOD. CONVECTION MAY LINGER INTO THE NIGHT IN THE MOIST AIR MASS
WITH SOME UPR SUPPORT. THE FRONT IS PROGGED TO SETTLE ROUGHLY ALONG
THE BLUE RIDGE ON MONDAY...WITH PLENTY OF AFTN INSTBY ONCE AGAIN.
EXPECTING SCATTERED TO NUMEROUS SHWRS AND TSTMS TO
DEVELOP...POSSIBLY MOST FAVORED IN THE PIEDMONT ON WARM SIDE OF THE
FRONT. HIGHS WILL BE NEAR NORMAL BOTH DAYS...WITH SLIGHTLY ABOVE
NORMAL OVERNIGHT TEMPS.
THE FORECAST FOR TUESDAY AND WEDNESDAY WERE UNCHANGED...AS LATEST
MODEL TRENDS AND THE 00Z WPC GRIDS ARE IN LINE WITH EARLIER
THINKING. STILL EXPECTING THE FRONT TO SAG SE THRU THE CAROLINAS ON
TUESDAY...WITH A LINGERING CHC POP MAINLY SE OF I-85. THEN JUST A
SLGT CHC POP FOR MOST OF THE AREA ON WEDNESDAY...AS CANADIAN HIGH
PRES BUILDS IN ACRS THE GREAT LAKES TO THE SOUTHEAST STATES. TEMPS
WILL BE NEAR NORMAL.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AT KCLT...MVFR STRATUS HAS DEVELOPED ALONG THE BLUE RIDGE AND BACK
ACROSS THE CENTRAL AND WESTERN UPSTATE...BUT THE RUC AND SREF IMPLY
THAT THE LOW CLOUDS WILL STAY WEST OF THE AIRFIELD THIS MORNING.
HOWEVER...THERE WILL BE SOME SHALLOW GROUND FOG AROUND THE REGION
THIS MORNING. TYPICALLY THIS DOESN/T AFFECT KCLT AND NOTHING HAS
BEEN INCLUDED. STRATUS LOOKS MORE LIKELY TONIGHT AND A LOT OF
GUIDANCE IS POINTING TO CIGS IN THE IFR RANGE. I/VE HEDGED A LITTLE
AT THIS POINT AND GONE WITH SCT010...BUT THIS ALMOST CERTAINLY
OVERLY OPTIMISTIC.
ELSEWHERE...IT/S INTERESTING THAT THE LATEST RUN OF THE SREF AS WELL
AS THE HI RES WRF-NMM AND WRF-ARW ARE NOT DOING AS GOOD A JOB WITH
THE ORIENTATION OF THE STRATUS DECK THAT HAS MOVED INTO THE REGION
AS THEIR PREVIOUS RUNS. AT ANY RATE...AN MVFR DECK CURRENTLY COVERS
THE UPSTATE AND UPPER FRENCH BROAD VALLEY FROM KGSP AND KAVL
EASTWARD. THE CLOUDS HAVE LOWERED INTO THE IFR RANGE UPSTREAM OF THE
REGION AT KGVL AND KAHN. KAND MAY SEE A PERIOD OF IFR...BUT I THINK
MOST SITES WILL STAY BETWEEN 1200-1500 FEET. THE COLD COVER IS
RATHER EXTENSIVE UPSTREAM. THE LATEST RUC 925 MB RH FIELD IMPLIES
THAT WE MAY HOLD ON TO CIGS THROUGH NOON...THOUGH I THINK THEY WILL
GRADUALLY RISE.
STRATUS SHOULD BE EVEN MORE WIDESPREAD AND LOWER TONIGHT. THE LATEST
SREF...NAM BUKFIT AND GFS MOS INDICATE THAT WE WILL SEE IFR CIGS. I
HAVE INCLUDED THIS AT THE UPSTATE AND KAVL. I KEPT CIGS A BIT HIGHER
AT KHKY...WHERE PROBS ARE A BIT LOWER...BUT I SUSPECT THEY WILL SEE
IFR AS WELL.
OUTLOOK...GENERALLY FAIR CONDITIONS ARE EXPECTED THROUGH SATURDAY.
HOWEVER...RESTRICTIONS FROM MORNING STRATUS...AND POSSIBLY
FOG...WILL CONTINUE EACH MORNING THRU SUNDAY. CHANCES FOR MAINLY
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL INCREASE
SIGNIFICANTLY BY SUNDAY AFTERNOON...AS A COLD FRONT APPROACHES FROM
THE TN VALLEY.
CONFIDENCE TABLE...
11-17Z 17-23Z 23-05Z 05-11Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 90%
KGSP LOW 58% HIGH 100% HIGH 100% HIGH 93%
KAVL MED 67% HIGH 100% HIGH 100% HIGH 93%
KHKY MED 72% HIGH 100% HIGH 100% MED 75%
KGMU LOW 58% HIGH 100% HIGH 100% HIGH 95%
KAND MED 74% HIGH 100% HIGH 100% HIGH 98%
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 GREENVILLE-SPARTANBURG SC
640 AM EDT THU MAY 30 2013
.SYNOPSIS...
HIGH PRESSURE CENTERED OVER THE ATLANTIC WILL KEEP US DRY WITH
TEMPERATURES SLIGHTLY ABOVE AVERAGE THROUGH THE END OF THE WEEK. THE
HIGH MOVES OFF THE ATLANTIC COAST OVER THE WEEKEND...AND A COLD
FRONT APPROACHES BY EARLY NEXT WEEK...RETURNING US TO AN UNSETTLED
PATTERN.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE AREAL DISTRIBUTION OF CLOUD COVER IS WORKING OUT ABOUT AS
EXPECTED...WITH OVERCAST SKIES OVER THE SRN APPALACHAINS...THE WRN
UPSTATE AND NE GA. THE MOISTURE MAY NOT BE AS SHALLOW AS I
ORIGINALLY THOUGHT AND SOME LOCATIONS IN THIS AREA MAY BE CLOUDY
THROUGH NOON. FARTHER TO THE EAST...INCLUDING THE WRN NC PIEDMONT
AND THE NE UPSTATE...THE LLVLS ARE DRIER AND IT SHOULD BE MAINLY
SUNNY EXPECT FOR SOME CIRRUS AND A FEW CU THAT WILL LIFT AN HOUR OR
TWO AFTER SUNRISE.
AS OF 440 AM EDT THURSDAY...MVFR CIGS ARE FILLING IN QUICKLY OVER NE
GA AND WE APPEAR TO BE ON TRACK FOR A STRATUS DECK TO INVADE THE
FORECAST AREA FROM THE SOUTHWEST OVER THE NEXT FEW HOURS. I DID
TWEAK SKY COVER TO ACCOUNT FOR CURRENT TRENDS...HOWEVER.
AS OF 300 AM EDT THURSDAY...MVFR LEVEL STRATUS IS EXPANDING ACROSS
SOUTHERN AND CENTRAL GA EARLY THIS THURSDAY MORNING. THE SREF SHOWS
A HIGH PROBABILITY THAT IT WILL CONTINUE TO EXPAND NORTH AND
NORTHEAST...EVENTUALLY SPREADING ACROSS NE GA...THE WRN UPSTATE AND
THE SRN NC MTNS. I/VE CARRIED MOSTLY CLOUDY SKIES EARLY IN THE DAY
TO ACCOUNT FOR THIS...BUT THE CLOUD LAYER SHOULD BE SHALLOW AND
SHOULD MIX INTO A CU FIELD FAIRLY QUICKLY BY LATE MORNING. OTHERWISE
IT WILL BE DRY ACROSS THE ENTIRE FORECAST AREA TODAY WITH MAX TEMPS
RUNNING ABOUT A CATEGORY ABOVE NORMAL.
WE WILL PROBABLY SEE STRATUS DEVELOP AGAIN TONIGHT. IN FACT...WITH
HIGHER BNDRY LAYER RH/S AND A STRONGER WIND FIELD...IT IS LIKELY TO
COVER MOST OF THE FORECAST AREA. STILL...IT/S NOT A GIVEN THAT THIS
WILL HAPPEN AND MY SKY COVER IS RATHER LOW...ESPECIALLY ACROSS WRN
NC.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 245 AM THURSDAY...UPPER RIDGE WILL BEGIN TO BREAK DOWN AND
SHIFT EAST FURTHER OFF THE ATLANTIC COAST DURING THE SHORT
TERM...BUT OVERALL WILL CONTINUE TO INFLUENCE OUR SENSIBLE WX. LLVL
FLOW WILL REMAIN LIGHT GENERALLY OUT OF THE S/SE OFF THE ATLANTIC.
MODELS IN BETTER AGREEMENT ON MORNING STRATUS DEVELOPING AND BEING A
LITTLE BIT MORE WIDESPREAD FRIDAY MORNING...BUT SHUD SCATTER OUT BY
MIDDAY. FCST SNDGS SHOW WEAK CAPE WITH INHIBITION FRI AFTN...SO
GOING WITH A DRY FCST.
ON SATURDAY...ONCE AGAIN...GUIDANCE INDICATING MORNING STRATUS
DEVELOPMENT...WITH INCREASE IN SOME MID-UPR MOISTURE AS WELL.
OVERALL...STILL LOOKS LIKE ANOTHER DRY DAY...ALTHO WILL KEEP A SLGT
CHC POP FOR THE NC MTNS...THANKS TO SOME INCREASED MOISTURE IN A
VEERING SWLY LLVL FLOW. HIGHS BOTH DAYS WILL BE SIMILAR TO LAST
COUPLE OF DAYS...ABOUT A CATEGORY OR TWO ABOVE NORMAL...WITH NEAR OR
SLIGHTLY ABOVE NORMAL OVERNIGHT LOWS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...UNSETTLED WEATHER LOOKS TO RETURN THE CWFA
FOR SUNDAY INTO EARLY NEXT WEEK.
A COLD FRONT WILL APPROACH THE AREA FROM THE WEST ON SUNDAY...WITH A
PLUME OF DEEP RH AND HEIGHT FALLS ENTERING THE NC MTNS BY PEAK
HEATING. SO A SOLID CHC TO LOW-END LIKELY POPS FOR SUNDAY LOOKS
GOOD. CONVECTION MAY LINGER INTO THE NIGHT IN THE MOIST AIR MASS
WITH SOME UPR SUPPORT. THE FRONT IS PROGGED TO SETTLE ROUGHLY ALONG
THE BLUE RIDGE ON MONDAY...WITH PLENTY OF AFTN INSTBY ONCE AGAIN.
EXPECTING SCATTERED TO NUMEROUS SHWRS AND TSTMS TO
DEVELOP...POSSIBLY MOST FAVORED IN THE PIEDMONT ON WARM SIDE OF THE
FRONT. HIGHS WILL BE NEAR NORMAL BOTH DAYS...WITH SLIGHTLY ABOVE
NORMAL OVERNIGHT TEMPS.
THE FORECAST FOR TUESDAY AND WEDNESDAY WERE UNCHANGED...AS LATEST
MODEL TRENDS AND THE 00Z WPC GRIDS ARE IN LINE WITH EARLIER
THINKING. STILL EXPECTING THE FRONT TO SAG SE THRU THE CAROLINAS ON
TUESDAY...WITH A LINGERING CHC POP MAINLY SE OF I-85. THEN JUST A
SLGT CHC POP FOR MOST OF THE AREA ON WEDNESDAY...AS CANADIAN HIGH
PRES BUILDS IN ACRS THE GREAT LAKES TO THE SOUTHEAST STATES. TEMPS
WILL BE NEAR NORMAL.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AT KCLT...MVFR STRATUS HAS DEVELOPED ALONG THE BLUE RIDGE AND BACK
ACROSS THE CENTRAL AND WESTERN UPSTATE...BUT THE RUC AND SREF IMPLY
THAT THE LOW CLOUDS WILL STAY WEST OF THE AIRFIELD THIS MORNING.
HOWEVER...THERE WILL BE SOME SHALLOW GROUND FOG AROUND THE REGION
THIS MORNING. TYPICALLY THIS DOESN/T AFFECT KCLT AND NOTHING HAS
BEEN INCLUDED. STRATUS LOOKS MORE LIKELY TONIGHT AND A LOT OF
GUIDANCE IS POINTING TO CIGS IN THE IFR RANGE. I/VE HEDGED A LITTLE
AT THIS POINT AND GONE WITH SCT010...BUT THIS ALMOST CERTAINLY
OVERLY OPTIMISTIC.
ELSEWHERE...IT/S INTERESTING THAT THE LATEST RUN OF THE SREF AS WELL
AS THE HI RES WRF-NMM AND WRF-ARW ARE NOT DOING AS GOOD A JOB WITH
THE ORIENTATION OF THE STRATUS DECK THAT HAS MOVED INTO THE REGION
AS THEIR PREVIOUS RUNS. AT ANY RATE...AN MVFR DECK CURRENTLY COVERS
THE UPSTATE AND UPPER FRENCH BROAD VALLEY FROM KGSP AND KAVL
EASTWARD. THE CLOUDS HAVE LOWERED INTO THE IFR RANGE UPSTREAM OF THE
REGION AT KGVL AND KAHN. KAND MAY SEE A PERIOD OF IFR...BUT I THINK
MOST SITES WILL STAY BETWEEN 1200-1500 FEET. THE COLD COVER IS
RATHER EXTENSIVE UPSTREAM. THE LATEST RUC 925 MB RH FIELD IMPLIES
THAT WE MAY HOLD ON TO CIGS THROUGH NOON...THOUGH I THINK THEY WILL
GRADUALLY RISE.
STRATUS SHOULD BE EVEN MORE WIDESPREAD AND LOWER TONIGHT. THE LATEST
SREF...NAM BUKFIT AND GFS MOS INDICATE THAT WE WILL SEE IFR CIGS. I
HAVE INCLUDED THIS AT THE UPSTATE AND KAVL. I KEPT CIGS A BIT HIGHER
AT KHKY...WHERE PROBS ARE A BIT LOWER...BUT I SUSPECT THEY WILL SEE
IFR AS WELL.
OUTLOOK...GENERALLY FAIR CONDITIONS ARE EXPECTED THROUGH SATURDAY.
HOWEVER...RESTRICTIONS FROM MORNING STRATUS...AND POSSIBLY
FOG...WILL CONTINUE EACH MORNING THRU SUNDAY. CHANCES FOR MAINLY
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL INCREASE
SIGNIFICANTLY BY SUNDAY AFTERNOON...AS A COLD FRONT APPROACHES FROM
THE TN VALLEY.
CONFIDENCE TABLE...
10-16Z 16-22Z 22-04Z 04-10Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 95%
KGSP MED 61% HIGH 93% HIGH 100% HIGH 97%
KAVL MED 65% HIGH 100% HIGH 100% HIGH 97%
KHKY MED 73% HIGH 100% HIGH 100% MED 79%
KGMU MED 63% HIGH 93% HIGH 100% HIGH 100%
KAND MED 65% HIGH 93% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...LEV
NEAR TERM...MCAVOY
SHORT TERM...ARK
LONG TERM...ARK
AVIATION...MCAVOY
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1043 AM CDT THU MAY 30 2013
.UPDATE...
WE ARE RAMPING UP THE SEVERE THREAT FOR SOUTH CENTRAL WI FOR THIS
AFTERNOON. THERE IS A HIGH PROBABILITY OF STRONG THUNDERSTORMS IN
THE UPPER MIDWEST...AND A GOOD CHANCE OF SEVERE WINDS IN SOUTH
CENTRAL WI. SOUTHERN WISCONSIN IS BACK IN THE SLIGHT RISK FOR SEVERE
WEATHER AREA TODAY/TONIGHT.
A STRONG SHORTWAVE CURRENTLY OVER OKLAHOMA WILL BE SWINGING UP INTO
IOWA AROUND 21Z THIS AFTERNOON. THERE IS A WEAKER SHORTWAVE OUT
AHEAD OF THAT WHICH WILL GET INTO EASTERN IOWA/SOUTHERN WI JUST
AFTER 18Z. THE LEADING SHORTWAVE WILL NEED TO BE WATCHED FOR EARLY
AFTERNOON CONVECTION OVER SOUTH CENTRAL WI. THE MAIN STRONG
SHORTWAVE WILL LIKELY DRIVE A THUNDERSTORM COMPLEX ACROSS ALL OF
SOUTHERN WISCONSIN LATE AFTERNOON EARLY EVENING.
THE SPC STORM SCALE ENSEMBLE OF OPPORTUNITY SHOWS A TONGUE OF HIGH
PROBABILITY OF UPDRAFT HELICITY VALUES GREATER THAN 25 M2/S2
STRETCHING INTO CENTRAL WISCONSIN. THE HIGHEST VALUES ARE FOCUSED
OVER THE PLAINS AND EASTERN IOWA...BUT THE 60-70 PERCENTS OVER SOUTH
CENTRAL WI ARE STILL VERY IMPRESSIVE. THE CRAVEN-WIEDENFELD
AGGREGATE SEVERE PARAMETER WHICH COMPILES INGREDIENTS FOR SEVERE
THUNDERSTORMS AND GIVES A SCORE/PERCENTAGE CONTINUES TO HAVE VERY
HIGH VALUES IN SOUTHWEST AND SOUTH CENTRAL WI IN THE 75-82 PERCENT
RANGE...WITH RUC13 VALUES EVEN HIGHER. IN ADDITION...CIPS ANALOGS
SHOW A HISTORY OF SEVERE WEATHER OCCURRING WITH THE CURRENT SYNOPTIC
PATTERN.
MODE OF CONVECTION IS STILL IN QUESTION. THE MOST LIKELY MODE IS
LINES OF STORMS PRODUCING BOWING SEGMENTS. THE SHEAR IS RELATIVELY
WEAK OVER THE REGION AND UNIDIRECTIONAL. IT IS FORECAST TO
STRENGTHEN THROUGH THE AFTERNOON...AS WILL LOW LEVEL WIND
SHEAR...WHICH WOULD HELP CELLS REMAIN MORE DISCRETE OR HAVE JUST
SMALL BOWING LINE SEGMENTS. TORNADO DEVELOPMENT WILL BE POSSIBLE
GIVEN LOW LCL AND HIGH LOW LEVEL SHEAR. THE WIDESPREAD CUMULUS
CLOUDS THAT DEVELOPED THIS MORNING WILL ACTUALLY HELP THE SEVERE
SITUATION BY KEEPING US FROM MIXING OUT TOO MUCH AND ALLOWING THE
DEWPOINTS TO REMAIN HIGH.
THE 13Z HRRR IS SHOWING A MORE DISCRETE MODE OVER SOUTHERN WI EARLY
THIS AFTERNOON...WITH A SQUALL LINE/MCS DEVELOPING WITH THE BIGGER
VORT MAX LATE THIS AFTERNOON/EVENING. THE QUAD CITIES NWS OFFICE
WILL BE DOING AN 18Z UPPER AIR SOUNDING TO ALLOW US TO BETTER ASSESS
THE SEVERE POTENTIAL.
&&
.AVIATION/18Z TAFS/...
EXPECT GUSTS BETWEEN 25 AND 30 KTS TO LAST THROUGH MOST OF THE DAY.
MVFR BROKEN CUMULUS CLOUDS DEVELOPED AND WILL GRADUALLY LIFT TO VFR
BY 18Z.
STORMS WILL DEVELOP OVER EASTERN IOWA AND MOVE NORTHEAST INTO
SOUTHERN WISCONSIN EARLY THIS AFTERNOON. MADISON WILL HAVE THE BEST
CHANCE FOR EARLIER THUNDERSTORMS. SOME MAY BE SEVERE. THEN ANOTHER
ROUND OF THUNDERSTORMS IS EXPECTED LATE AFTERNOON/EARLY EVENING AND
THESE WILL LIKELY SPREAD ALL THE WAY INTO SOUTHEAST WI.
STRAIGHT-LINE WINDS ARE THE MAIN SEVERE WEATHER THREAT.
&&
.MARINE...
GUSTY SOUTH WINDS DUE TO MIXING OVER THE LAND WILL AFFECT SHORELINE
NEARSHORE AREAS ALL DAY TODAY. MAY NEED A SMALL CRAFT ADVISORY TO
HANDLE THIS. 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. STABLE AIR
DOWN AT LAKE LEVEL WILL KEEP WAVES FROM RESPONDING TOO MUCH TO THE
GUSTY WINDS.
&&
.PREV DISCUSSION... /ISSUED 449 AM CDT THU MAY 30 2013/
TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM
CONVECTION HAS LIFTED NORTH OF THE FORECAST AREA WITH SHORT WAVE/MCV
AND ADDITIONAL SUPPORT FROM RIGHT ENTRANCE REGION OF UPPER JET.
MODELS DAMPEN FIRST SHORT WAVE CURRENTLY DRIVING SRN PLAINS
CONVECTION AND FOCUS ON WAVE NEAR THE PANHANDLE REGION THAT WILL
SWING UP TOWARDS IA/NEB BY 00Z FRI AS 500 MB LOW GOES NEGATIVE-TILT.
WITH COMBINATION OF CENTRAL PLAINS SHORT WAVE/MCV AND 850 MB JET MAX
AND INSTABILITY ON AREA SOUNDINGS...THOUGH CAPE VALUES MAY BE A BIT
TOO HIGH DUE TO GENEROUS SURFACE DEW POINTS...WILL FOLLOW CONSENSUS
BLEND POPS AND INCREASE PRECIPITATION CHANCES RAPIDLY THROUGH THE
MORNING. HIGH POPS CONTINUE INTO THE EVENING...THEN TAPER OFF AS
FORCING WITH WAVE AND LOW-LEVEL JET MAX LIFT OFF TOP THE NORTHEAST.
WILL HAVE TO WATCH WESTERN COUNTIES OF S CENTRAL WI FOR FLASH
FLOODING POTENTIAL AFTER RECEIVING HEAVY RAIN WITH THE CONVECTION
WEDNESDAY EVENING.
LATEST SPC DAY 1 OUTLOOK HAS SHIFTED SLIGHT RISK TO THE SOUTHWEST
OUT OF OF WISCONSIN AS FAVORABLE SHEAR FOR ROTATING CELLS LESSENS
THROUGH THE DAY...BUT AN ISOLATED WIND/HAIL MAKER NOT OUT OF THE
QUESTION.
FRIDAY AND SATURDAY...FORECAST CONFIDENCE...MEDIUM
SOUTHERN WISCONSIN WILL REMAIN IN THE WARM SECTOR FRIDAY AS LOW
PRESSURE OVER NORTH DAKOTA AND MINNESOTA REMAINS NEARLY
STATIONARY. SHOWERS AND STORMS ARE THUS LIKELY ONCE AGAIN. THOUGH
THE BEST LOW LEVEL FLOW WILL BE TO THE SOUTH AND EAST...STRONGER
STORMS ARE NOT OUT OF THE QUESTION WITH SIMILAR UP TO 1000 J/KG OF
SURFACE BASED CAPE...AND WIND SHEAR ACTUALLY A BIT HIGHER THAN
PREVIOUS DAYS. LOOKS LIKE BEST CHANCE FOR SHOWERS AND STORMS WILL
BE LATE AFTERNOON INTO THE NIGHT...AS ANOTHER SHORTWAVE ROTATES
THROUGH THE AREA.
TEMPERATURES WILL BE SIMILAR FRIDAY AS THURSDAY...PUSHING OR
REACHING 80 MOST PLACES. PROBABLY A BIT TRICKY NEAR THE LAKE AGAIN
UNDER SOUTHERLY WINDS...BUT MOST AREAS SHOULD SEE THE WARMER TEMPS.
WEAKENING LOW PRESSURE WILL FINALLY DRAG A COLD FRONT THROUGH
SOUTHERN WISCONSIN BY SATURDAY NIGHT. MODELS HAVE SLOWED A BIT WITH
THE FRONT...SO TEMPS AND POPS HAVE TRENDED IT BIT HIGHER WITH
SOUTHERN WISCONSIN REMAINING IN THE WARM SECTOR A BIT LONGER.
SUNDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE...MEDIUM
MAIN UPPER LEVEL TROUGH AXIS WILL MOVE THROUGH SUNDAY...POSSIBLY
BRINGING A FEW SHOWERS. COOLER AIR IS EXPECTED TO ARRIVE WITH THE
SHORTWAVE...WITH TEMPERATURES FALLING BACK BELOW NORMAL.
SHOULD BE PLEASANT MONDAY UNDER HIGH PRESSURE...WITH A CHANCE FOR
SHOWERS AND STORMS RETURNING LATER TUESDAY INTO WEDNESDAY. HIGHS
WILL LIKELY REMAIN A FEW DEGREES BELOW NORMAL THROUGH THE FIRST HALF
OF NEXT WEEK.
AVIATION/12Z TAFS/...
WILL KEEP WIND SHEAR IN ALL OF THE TAFS...WITH WIND PROFILERS
PICKING UP 35 TO 40 KT WINDS BETWEEN 1500-2000 FT...UNTIL SURFACE
WINDS INCREASE WITH MIXING AFTER DAYBREAK. EXPECT SOUTHERLY GUSTS
BETWEEN 25 AND 30 KTS BY MID-MORNING AND LASTING THROUGH MOST OF
THE DAY.
INCREASED LOW-LEVEL MOISTURE AND COOLING EFFECTS OF LAST NIGHT/S
STORMS HAVE PRODUCED FOG AT KMSN WHICH SHOULD LIFT WITH INCREASING
WINDS AFTER SUNRISE. OTHERWISE VFR CONDITIONS THROUGH MOST OF THE DAY.
WHILE EXACT TIMING IS QUESTIONABLE...WEAK UPPER DISTURBANCE AND
ANOTHER LOW-LEVEL JET MAX APPROACHING THE UPPER MIDWEST WILL BRING
INCREASING CHANCES FOR THUNDERSTORMS. BEST CHANCES STAY WEST OF
KMSN UNTIL MID-LATE MORNING...THEN SPREAD EAST AND INCREASE THROUGH
THE AFTERNOON. SHOWERS AND STORMS MOST LIKELY FROM LATE AFTERNOON
THROUGH THE EVENING BRINGING MVFR CIGS/VSBYS...POSSIBLY DROPPING
TO IFR WITH HEAVY DOWNPOURS OF RAIN. WILL THEN KEEP MVFR
CONDITIONS THROUGH THE REMAINDER OF THE FORECAST.
MARINE...
SOUTH WINDS WILL INCREASE RAPIDLY AFTER SUNRISE...WITH
GUSTS TO 20 KNOTS BY MID TO LATE MORNING. PREVAILING WINDS HOLD JUST
BELOW SMALL CRAFT CRITERIA...THOUGH THERE WILL BE A FEW GUSTS TO
25 KNOTS. HAVE ADDED A CAUTIONARY STATEMENT FOR SMALL CRAFT IN THE
NEARSHORE FORECAST AND IN THE HAZARDOUS WEATHER OUTLOOK FOR TODAY.
EXPECT THUNDERSTORM CHANCES TO INCREASE THROUGH THE LATE MORNING
AND AFTERNOON...BECOMING MOST LIKELY THIS EVENING. WHILE THE STORMS
ARE EXPECTED TO STAY BELOW SEVERE LEVELS...GUSTY WINDS...SMALL
HAIL AND VISIBILITY-REDUCING HEAVY RAINS ARE POSSIBLE.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...MRC
TODAY/TONIGHT AND AVIATION/MARINE...REM
FRIDAY THROUGH WEDNESDAY...DDV
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
600 AM CDT THU MAY 30 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 333 AM CDT THU MAY 30 2013
CURRENTLY AS OF 0830Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT
ANALYSIS SHOWED UPPER TROUGHING FROM THE NORTHEAST PACIFIC INTO THE
NORTHERN ROCKIES WITH AN UPPER LOW IN NORTHEAST WYOMING...WHILE
DOWNSTREAM RIDGING WAS PRESENT ACROSS THE EASTERN U.S.. ALSO TO NOTE
ON WATER VAPOR IS A FAIRLY POTENT SHORTWAVE OVER THE TEXAS AND
OKLAHOMA PANHANDLES IN THE BASE OF THIS TROUGHING. NEARLY
UNIDIRECTIONAL SOUTH TO SOUTHWEST FLOW EXISTED BETWEEN THE TROUGHING
AND RIDGING... WITH SOME VERY STRONG WINDS AT 850MB. VWP AND
PROFILER DATA SHOWED SPEEDS OF 50-65 KT FROM CENTRAL OKLAHOMA INTO
SOUTHERN MINNESOTA. THESE WINDS WERE TRANSPORTING COPIOUS AMOUNTS OF
MOISTURE NORTHWARD...NOTED BY PRECIPITABLE WATER VALUES OF 1.5-1.75
INCHES OR 150-180 PERCENT OF NORMAL. NUMEROUS SHORTWAVES...SOME
CONVECTIVELY INDUCED...RIDING THROUGH THE MID LEVEL FLOW HAS BEEN
INTERACTING WITH THE MORE SUMMER-LIKE AIRMASS TO CONTINUE TO PRODUCE
SCATTERED CLUSTERS OF SHOWERS AND THUNDERSTORMS. MUCH OF THE
FORECAST AREA LIES IN THE WARM SECTOR OF A LOW PRESSURE SYSTEM BACK
IN THE DAKOTAS. MAIN WARM FRONT HAS LIFTED INTO NORTHERN WISCONSIN
WHILE THE COLD FRONT IS WELL BACK TO THE WEST IN CENTRAL SOUTH
DAKOTA.
MODELS ARE IN GOOD AGREEMENT ON THE SYNOPTICS THROUGH TONIGHT...
INDICATING THAT THE UPPER TROUGHING FROM WYOMING INTO THE TEXAS
PANHANDLE WILL SHIFT EAST NORTHEAST INTO THE FORECAST AREA BY 06Z
TONIGHT. THERE ARE SOME DECENT 500MB HEIGHT FALLS BETWEEN 18Z-06Z
OVER THE FORECAST AREA...ON THE ORDER OF 60-90 METERS. THE DPVA FROM
THE APPROACH OF THIS UPPER TROUGH...AS WELL AS VARIOUS SHORTWAVES
AND CONVECTIVELY INDUCED SHORTWAVES AHEAD OF IT...SUGGESTS PLENTY OF
FORCING FOR CONVECTION. MODELS HAVE SHOWN THIS FOR MANY DAYS AS
WELL. THIS FORCING MAY MAKE IT HARD TO BUILD A LOT OF INSTABILITY...
COMPARED TO YESTERDAY WHERE WE HAD PLENTY OF SUNSHINE BEFORE
CONVECTION ERUPTED. RAP/NAM/GFS SOUNDINGS ALL SUGGEST ANY 0-1 MLCIN
FROM NOCTURNAL INFLUENCES BEING NEARLY COMPLETELY GONE BY 15Z.
THEREFORE IT IS CONCEIVABLE FOR CONVECTION TO FIRE SHORTLY
THEREAFTER WHEN 0-1 MLCAPE IS ONLY AT 800-1500 J/KG. HRRR/RAP MODELS
SHOW CONVECTION FIRING IN THAT 15-16Z WINDOW...IN AGREEMENT WITH THE
ABOVE ANALYSIS. THE CONVECTION MAY STABILIZE THINGS BRIEFLY...BUT
PERSISTENT HEATING THROUGH THE DAY COMBINED WITH SOUTHERLY WARM
ADVECTION OF INSTABILITY SHOULD PROVIDE FUEL TO CONTINUE PERIODS OF
CONVECTION THROUGH THE DAY AND INTO THE EVENING. PASSAGE OF THE
UPPER TROUGH AND NOCTURNAL COOLING SHOULD ALLOW CONVECTION TO
SUBSIDE AFTER MIDNIGHT.
REGARDING SEVERE POTENTIAL...THE LIMITATION OF BUILDING A LOT OF
CAPE IS A HINDRANCE. 0-6KM SHEAR FROM THE 30.00Z NAM/GFS IS
GENERALLY PROGGED AT 25-30 KT THROUGH THE DAY...FAVORING FOR MORE OF
A MULTI-CELL SITUATION. WITH INSTABILITY STRUGGLING...NOT THINKING
MUCH IN THE WAY FOR SEVERE HAIL. BULK OF THE AFOREMENTIONED 0-6KM
SHEAR IS IN THE 0-3KM LAYER...AND COMBINED WITH 850MB WINDS PROGGED
IN THE AFTERNOON AND EVENING OF 45-50 KT DOES BRING UP A CONCERN FOR
THE STORMS TO PRODUCE STRONG TO DAMAGING WIND GUSTS. 0-1KM SHEAR IS
QUITE HIGH AS WELL FOR THE AFTERNOON AND EVENING...SIMILAR TO 0-3KM
OF 25-30KT...SO WE MAY WANT TO WATCH FOR POSSIBLE TORNADOES TOO.
THIS WOULD BE ESPECIALLY TRUE ALONG ANY CONVECTIVE OUTFLOW BOUNDARY
AND/OR IF WE CAN GET MORE DAYTIME HEATING THAN EXPECTED.
ON THE FLOODING FRONT...MORE INFORMATION CAN BE FOUND IN THE
HYDROLOGY SECTION BELOW. BRIEFLY...THE PATTERN TODAY INTO THIS
EVENING IS VERY FAVORABLE FOR STORMS TO TRAIN ACROSS THE SAME AREAS
AS THEY MARCH SOUTH TO NORTH. WITH PRECIPITABLE WATER VALUES STAYING
UP IN THE 1.5-1.75 INCH RANGE ANY STORM CAN PRODUCE HEAVY RAIN. WITH
GROUNDS ALREADY SATURATED...FLASH FLOODING IS CERTAINLY POSSIBLE...
ESPECIALLY SOUTH OF I-90 WHICH WAS REALLY IMPACTED FROM YESTERDAY
INTO LAST NIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 333 AM CDT THU MAY 30 2013
LOW PRESSURE OVER THE EASTERN DAKOTAS PUSHES SOUTHEAST LATE FRIDAY
MORNING INTO FRIDAY AFTERNOON DRIVING THE FRONT ACROSS THE FORECAST
AREA. DEPENDING ON THE TIMING OF THIS FRONT...SEVERE WEATHER POSSIBLE
ON FRIDAY. FORECAST MODELS ARE IN REASONABLE AGREEMENT...SHOWING
0-3 KM MUCAPE VALUES CLIMBING TO 2000 TO 3000 J/KG. SHEAR IS ALSO
RAMPING UP LATE FRIDAY MORNING INTO FRIDAY AFTERNOON WITH 0-6 KM
BULK SHEAR INCREASING TO 45 TO 55 KTS. THE HIGHEST INSTABILITY
APPEARS TO BE OVER FAR NORTHEAST IOWA AND INTO EXTREME SOUTHWEST
WISCONSIN. WILL HAVE TO KEEP A VERY CLOSE WATCH ON THIS OVER THE
NEXT FEW MODEL RUNS. AT THIS TIME...LARGE HAIL AND DAMAGING WINDS
APPEAR TO BE THE MAIN HAZARDS FROM THESE STORMS. BUT AGAIN...THE
SEVERE THREAT AREA WILL DEPEND ON WHERE THE BOUNDARY IS LOCATED
LATE FRIDAY MORNING INTO FRIDAY AFTERNOON AND HOW MUCH SURFACE
HEATING IS REALIZED. A DRY SLOT PUSHES INTO THE FORECAST AREA LATE
FRIDAY NIGHT AS THE LOW PUSHES EAST INTO THE WESTERN GREAT LAKES.
THERE SHOULD BE A DRY PERIOD AS THE LOW MOVES IN...BUT THEN
SHOWERS AND ISOLATED THUNDERSTORMS WILL DEVELOP ON SATURDAY AS THE
LOW SLIDES ACROSS THE REGION. AN UNSEASONABLY COOL AIRMASS MOVES
INTO REGION ON SUNDAY. 850 MB TEMPERATURES FALL TO 0 C OVER
NORTHERN WISCONSIN AND TO AROUND 2 C OVER NORTHEAST IOWA. THIS
WILL SET THE STAGE FOR A CHILLY NIGHT ACROSS THE AREA SUNDAY NIGHT
INTO EARLY MONDAY MORNING. ECMWF 850 MB TEMPERATURE STANDARDIZED
ANOMALIES FALL TO AROUND -1.5...INDICATIVE OF AN ANOMALOUSLY COLD
AIRMASS. TEMPERATURES WILL PLUMMET INTO THE UPPER 30S OVER FAR
NORTHERN WISCONSIN. WILL HAVE TO KEEP A VERY CLOSE WATCH ON LOWS OVER
NORTH CENTRAL AND CENTRAL WISCONSIN WHERE TYPICAL COLD SPOTS SUCH
AS SPARTA AND BLACK RIVER FALLS COULD SEE LOWS DIP INTO THE UPPER
30S...LEADING TO FROST FORMATION. COOL HIGH PRESSURE REMAINS OVER
THE REGION THROUGH TUESDAY...WITH HIGHS ONLY IN THE 60S. HIGH
PRESSURE PUSHES EAST OF THE REGION LATE TUESDAY INTO WEDNESDAY AS
A TROUGH DIGS INTO THE DAKOTAS. SOUTHERLY FLOW DEVELOPS OVER THE
AREA HELPING TO USHER IN WARMER TEMPERATURES. THE TROUGH WILL MOVE
INTO THE FORECAST AREA LATE TUESDAY NIGHT THROUGH WEDNESDAY
BRINGING CHANCES FOR SHOWERS AND THUNDERSTORMS TO THE AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 600 AM CDT THU MAY 30 2013
DIFFICULT FORECAST FOR TIMING OF OCCASIONAL TO SCATTERED -SHRA/TS
TODAY INTO TONIGHT. CHAOTIC SKY...LEFT OVER SURFACE BOUNDARIES...AND
UPPER LEVEL PIECES OF ENERGY COULD ALSO SERVE AS PCPN TRIGGERS.
WHERE THESE WILL BE...TIMING...AND WHEN SHRA/TS FIRE IS NOT CLEAR.
MEANWHILE...THE MAIN IMPETUS WILL BE WHERE THE LOW LEVEL MOISTURE
TRANSPORT INTERACTS WITH ANY OF THESE FEATURES. CONFIDENCE IS
HIGHEST FOR THE AFTERNOON AND EVENING HOURS...BUT ONLY FOR VCTS/VCSH
AT THIS TIME. UPDATES WILL BE NEEDED FOR KRST/KLSE TO BETTER REFINE
THE PCPN THREATS AS THEY BECOME MORE EVIDENT.
LOOK FOR AN INCREASE IN WINDS EARLY THIS MORNING AS MIXING KICKS IN
AND 40 KTS OF WIND SITS AROUND 2 KFT. LLWS STILL A THREAT UNTIL
14Z...BUT THERE SHOULD BE ENOUGH MIXING AT THE SFC - THUS INCREASE
IN THE SFC BASED WIND - THAT LLWS IN THE TAFS WILL NO LONGER BE
NEEDED. WINDS WILL STAY UP FOR MUCH OF TONIGHT AS TIGHT PRESSURE
GRADIENT HOLDS ACROSS THE REGION. BUFKIT SOUNDINGS AND SREF MODEL
GUIDANCE ALSO FAVOR A LOWERING OF THE CLOUD DECK INTO THE MVFR
CATEGORY. NOT ENTIRELY SOLD ON THIS...BUT ENOUGH SIGNALS FAVOR IT
THAT WILL ADD FOR THE OVERNIGHT HOURS.
&&
.HYDROLOGY...TODAY AND TONIGHT
ISSUED AT 333 AM CDT THU MAY 30 2013
HEAVY RAIN FELL ACROSS THE AREA WEDNESDAY AFTERNOON AND EVENING
WITH RAINFALL AMOUNTS OF 2 TO 3 INCHES REPORTED ACROSS PORTIONS OF
NORTHEAST IOWA...SOUTHEAST MINNESOTA AND SOUTHWEST
WISCONSIN...WITH LOCALLY HIGHER AMOUNTS OF 4 INCHES REPORTED. AN
ADDITIONAL 1 TO 2 INCHES OF RAIN IS EXPECTED ACROSS THE AREA
TODAY THROUGH THIS EVENING...WHICH COULD LEAD TO FLASH FLOODING.
IT WILL NOT TAKE MUCH RAIN OVER THE SATURATED SOILS TO CREATE
FLOODING ISSUES. ALSO...AREA RIVERS WILL SEE RISES AND POSSIBLE
FLOODING WITH ANY ADDITIONAL RAINFALL RECEIVED. HAVE EXPANDED THE
FLASH FLOOD WATCH NORTHWARD...INCLUDING AREAS ALONG AND SOUTHWEST
OF INTERSTATE 94 CORRIDOR EXCLUDING JUNEAU COUNTY
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR WIZ032>034-041-042-
053>055-061.
MN...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR MNZ079-086>088-
094>096.
IA...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR IAZ008>011-018-019-
029-030.
&&
$$
SHORT TERM...AJ/WETENKAMP
LONG TERM....WETENKAMP
AVIATION.....RIECK
HYDROLOGY....WETENKAMP
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1255 PM EDT THU MAY 30 2013
.SYNOPSIS...
HIGH PRESSURE WILL LINGER ACROSS THE CENTRAL ATLANTIC INTO THIS
WEEKEND, BRINGING INCREASING HEAT AND HUMIDITY TO THE MID ATLANTIC
STATES. EARLY NEXT WEEK, A LOW PRESSURE SYSTEM EMERGING FROM THE
GREAT LAKES WILL SEND A COLD FRONT THROUGH OUR REGION BY MONDAY.
HIGH PRESSURE SPREADING SOUTH FROM CENTRAL CANADA IS THEN EXPECTED
TO BUILD TOWARD OUR REGION THROUGH MID WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO SIGNIFICANT CHANGES WILL BE MADE WITH THE NEXT ESTF. LOOKS LIKE
THERE IS A BIT OF A SHORT WAVE ON THE WATER VAPOR IMAGERY AND CU
WEST OF US LOOK A BIT MORE ROBUST THAN THEY WERE AT THIS TIME YESTERDAY.
BASED ON THE 12Z SOUNDINGS, WE NUDGED MAX TEMPS EVER SO SLIGHTLY
HIGHER AND PROGRESSED THEM UPWARD A BIT FASTER. MAX HEAT INDICES
ARE IN THE LOWER 90S. TEMPERATURES NEAR THE WATER SHOULD BE
SEVERAL DEGREES COOLER THAN INLAND.
LATEST MESOSCALE MODELS RUN CONTINUE TO SUPPORT THE THINKING OF
ISOLATED OR SLIGHT CHANCE CONVECTION LATER TODAY NORTHWEST. 12Z
SOUNDINGS SHOW IAD AND APG AS CAPPED, BUT CAPPING NOT AS STRONG AT
SITES FARTHER TO THE NORTH AND CONVECTIVE TEMP EXPECTED TO BE
REACHED.
ON POPS, THE MID LEVEL RIDGE DOES BUILD TODAY OVER OUR AREA, AND A
RELATIVELY DRY SOUNDING DOES RESULT IN A RATHER HIGH LFC. HOWEVER,
WE THINK WE END UP WITH SOME CAPE AND NOT A LOT OF CIN DURING THE
AFTERNOON EVEN AFTER ADJUSTING FOR LOWER DEW POINTS. ALSO, THERE
SEEMS TO BE SOME WEAK ENERGY MOVING ALONG THE SKIRT OF THE RIDGE
THAT IS WEAKLY APPARENT ON WATER VAPOR IMAGERY AND THAT COULD WORK
WITH THE INSTABILITY TO TRIGGER CONVECTION. SPC HAS ALMOST THE
ENTIRE AREA UNDER A GENERAL RISK OF CONVECTION TODAY; WE JUST PUT
SLIGHT CHANCE POPS BACK INTO THE AREA NORTHWEST OF THE FALL LINE.
ON WINDS, WE SHOULD SEE A SOUTHWEST TO WEST WIND THAT PEAKS A BIT
ABOVE 10 MPH TODAY. THE H925 WINDS ARE IN OPPOSITION TO ANY SEA/BAY
BREEZE AND FORECAST TO BE AROUND 15 KT. THAT IS RIGHT ON THE EDGE OF
STOPPING IT FROM MAKING MUCH PROGRESS INLAND. SINCE THE LAND/WATER
TEMPERATURE DISCONTINUITY IS GOING TO BE CONSIDERABLE, WE DID
FORECAST IT TO MAKE A LITTLE MORE PROGRESS INLAND THAN WE MIGHT HAVE
LATER IN THE WARM SEASON. WE AREN`T FORECASTING ANY CONVECTION WITH
THE SEA BREEZE AT THIS POINT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
WHATEVER ENERGY IS AVAILABLE TO TRIGGER ANYTHING SHOULD BE GONE BY
DUSK, AND WE CARRY A DRY THURSDAY NIGHT. THE WINDS MAY DIE OFF A BIT
MORE QUICKLY THAN THEY DID EARLY THIS MORNING, AND SO WE ALLOW FOR A
BIT MORE RADIATING AND LEAN MODESTLY TOWARD COOLER GUIDANCE. WE
DON`T CARRY ANY FOG OR HAZE IN THIS FORECAST.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
FOR THE FIRST PART OF THE LONG TERM PERIOD, OUR REGION WILL BE IN
THE MIDST OF THE FIRST HEAT WAVE OF THE SEASON AS SURFACE HIGH
PRESSURE WILL BE FOUND TO OUR EAST ACROSS THE CENTRAL ATLANTIC, WITH
STRONG MID-LEVEL RIDGING ALOFT. THIS WILL PROMOTE AN INCREASING
SOUTHWESTERLY FLOW THROUGH THE MID ATLANTIC REGION, WITH 850MB AND
925MB MODEL TEMPERATURE DATA SUPPORTING MAXIMUM TEMPERATURES ACROSS
THE FORECAST AREA REACHING THE LOWER 90S FRIDAY AND FOR MUCH OF THE
AREA AGAIN ON SATURDAY. DEWPOINTS THROUGH THIS TIME FRAME WILL
MAINLY BE IN THE LOWER TO PERHAPS MIDDLE 60S, YIELDING HEAT INDEX
VALUES IN THE LOWER 90S EACH AFTERNOON. WE WILL CONTINUE A MENTION
IN OUR HAZARDOUS WEATHER OUTLOOK HIGHLIGHTING THIS MULTI-DAY HOT AND
SOMEWHAT MUGGY AIRMASS.
GOING INTO SUNDAY, THIS OVERALL PATTERN WILL BEGIN TO BREAK DOWN, AS
SURFACE HIGH PRESSURE WILL DRIFT FARTHER EAST INTO THE CENTRAL
ATLANTIC AND THE MID-LEVEL RIDGE WILL ALSO BEGIN TO PUSH OFFSHORE.
MEANWHILE, AN AREA OF LOW PRESSURE WILL BE EMERGING FROM AROUND THE
GREAT LAKES SUNDAY AND TRACKING INTO SOUTHEASTERN CANADA THROUGH
MONDAY, ALLOWING A TRAILING COLD FRONT TO APPROACH OUR REGION FROM
THE NORTHWEST. THERE LOOKS TO BE AMPLE INSTABILITY AND LOW LEVEL
MOISTURE IN PLACE AHEAD OF THE APPROACHING FRONTAL BOUNDARY FOR
POTENTIALLY STRONG CONVECTIVE ACTIVITY, AND WE STEADILY INCREASE
POPS FROM NORTHWEST TO SOUTHEAST THROUGH THE COURSE OF SUNDAY INTO
SUNDAY NIGHT. MODEL DIFFERENCES STILL EXIST BETWEEN THE ECMWF, GFS,
AND OTHERS REGARDING THE TIMING OF THE FRONTAL PASSAGE THROUGH THE
REGION MONDAY, AND WITH THIS UNCERTAINTY IN MIND, WE HAVE KEPT HIGH
CHANCE TO LIKELY POPS IN PLACE FOR THE BETTER PART OF MONDAY ACROSS
THE FORECAST AREA FOR SCATTERED SHWR/T-STORM ACTIVITY. FOLLOWING THE
FRONTAL PASSAGE, THERE IS FAIRLY GOOD MODEL AGREEMENT AS AN AREA OF
HIGH PRESSURE FROM CENTRAL CANADA IS PROGGED TO SPREAD SOUTH AND
EAST FROM THE LATTER PART OF MONDAY THROUGH THE MID-WEEK PERIOD.
THIS WILL BRING A NOTICEABLE CHANGE IN AIRMASS TO OUR REGION, WITH
MAXIMUM TEMPERATURES RETURNING TO MORE SEASONAL LEVELS.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
18Z TAFS WILL HAVE VFR CONDITIONS FORECAST THROUGH THE EVENING FOR
ALL TERMINALS AND VFR CONDITIONS ON FRIDAY.
FOR THIS AFTERNOON, NO CIGS ARE FORECAST. SOME HIGH BASED (5K TO
6K) SCATTERED CUMULUS CLOUDS ARE EXPECTED WITH WEST TO SOUTHWEST
WINDS AROUND 10 KTS. WE ARE BRINGING A SEA BREEZE FRONT TO KACY AT
21Z AND A BAY BREEZE FRONT TO KILG AT 22Z. BECAUSE OF THE WINDS
ABOVE THE BOUNDARY LAYER BEING WEST, WE ARE NOT EXPECTING THE SEA
BREEZE FRONT TO MAKE MUCH HEADWAY BEYOND THE IMMEDIATE COASTAL
COUNTIES.
ISOLATED THUNDERSTORMS ARE EXPECTED NORTHWEST OF THE TERMINALS
THIS AFTERNOON AND EARLY EVENING, BUT OVERALL COVERAGE AND
CONFIDENCE THAT THEY WILL MAKE IT TO THE TERMINALS IS TOO LOW TO
INCLUDE. LOWEST CONFIDENCE AT KABE AND KRDG.
FOR THIS EVENING, ANY CUMULUS CLOUDS AROUND SHOULD DISSIPATE
RAPIDLY AND JUST SOME CIRRUS IS EXPECTED. WINDS SHOULD BECOME
LIGHTER FROM THE SOUTHWEST AND LIGHT AND VARIABLE AT SOME OF THE
OUTLYING TERMINALS AND AIRPORTS. THIS SHOULD CONTINUE OVERNIGHT.
ALSO OVERNIGHT WE ARE FORECASTING SOME MVFR CONDITIONS LATE AT
KABE AND KRDG. CONFIDENCE SHOULD BE VIEWED AS AVERAGE.
ANOTHER VFR DAY ON FRIDAY. WE ARE EXPECTING EVEN LESS CUMULUS
BASED COVERAGE AND SLIGHTLY STRONGER WINDS WITH THE DIRECTION
SLIGHTLY MORE TOWARD THE SOUTH. WIND SPEEDS IN THE LAST FORECAST
GROUP ARE MORE REPRESENTATIVE OF THE LATE MORNING AND AFTERNOON
EXPECTATIONS.
OUTLOOK...
FRIDAY NIGHT AND SATURDAY...MAINLY VFR CONDITIONS WITH
SOUTHWESTERLY WINDS. SOME LOCAL REDUCED VSBYS POSSIBLE IN MORNING
HAZE.
SUNDAY AND MONDAY...MOSTLY VFR, EXCEPT TIMES OF POSSIBLE IFR/MVFR IN
SCATTERED SHWRS/T-STORMS, ESPECIALLY FROM SUNDAY AFTN THROUGH MONDAY
MORNING.
&&
.MARINE...
A MARINE LAYER SHOULD BE FAIRLY STRONG TODAY. WINDS ABOVE THE
SURFACE ARE NOT FORECAST TO BE THAT ROBUST, SO WE ARE FORECASTING A
SOUTHWEST WIND THAT IS NOTICEABLE BUT BELOW THE ADVISORY CRITERION.
A SEA/BAY BREEZE MAY MAKE MODEST PROGRESS OUT FROM THE COASTLINE AND
UP THE BAY, AND WINDS THERE MAY COME AROUND TO SOUTH. GIVEN THE
LATER HRRR WE WERE SLIGHTLY MORE AGGRESSIVE BRINGING A BAY BREEZE
UP THE DELAWARE.
SEAS WERE RUNNING AROUND 3 FT OVER THE ATLANTIC WATERS EARLY THIS
MORNING. AS THE PREVIOUS FORECASTER NOTED, WAVE WATCH GUIDANCE IS
VERIFYING TOO HIGH WITH SWELLS. WE CARRY SUB-ADVISORY SEAS THROUGH
THE TONIGHT.
OUTLOOK...
SUB-SCA CONDITIONS EXPECTED FOR OUR WATERS THROUGH FRIDAY AND MOST
OF SATURDAY AS AN AREA OF HIGH PRESSURE LINGERS ACROSS THE CENTRAL
ATLANTIC. BY SATURDAY NIGHT AND INTO SUNDAY, HIGH PRESSURE WILL BE
DRIFTING FARTHER EAST AND AWAY FROM THE REGION, WITH A COLD FRONT
APPROACHING THE AREA FROM THE NORTHWEST DURING SUNDAY. WE ANTICIPATE
WIND GUSTS AND SEAS TO REACH SMALL CRAFT ADVISORY LEVELS DURING THIS
TIME FRAME, AND THESE CONDITIONS WILL MOST LIKELY LAST INTO MONDAY,
AS WELL. SCATTERED SHWRS AND T-STORMS WILL ALSO REDUCE VISIBILITIES
FROM LATE SUNDAY THROUGH MONDAY FOR OUR WATERS, AS THE FRONT
APPROACHES AND TRACKS THROUGH THE REGION.
&&
.RIP CURRENTS...
WE CARRY A LOW PROBABILITY OF RIP CURRENTS TODAY.
RIP CURRENT AWARENESS WEEK IS JUNE 2 THROUGH 8.
PSA`S WILL AIR ON KPHI NWR AND POST DAILY AROUND 545 AM. THERE
WILL BE A SHORT AWARENESS PRESS CONFERENCE IN SURF CITY, LBI ON
TUE JUNE 4 AT 2 PM FOR THOSE MEDIA REPRESENTATIVES WHO ARE
INTERESTED IN RAISING RIP CURRENT AWARENESS AND IN CONDITIONS
FAVORING LIFE THREATENING DANGER IN THE UNGUARDED OCEAN SURF ZONE.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KLINE
NEAR TERM...DELISI/GIGI
SHORT TERM...DELISI
LONG TERM...KLINE
AVIATION...GIGI/KLINE
MARINE...DELISI/KLINE
RIP CURRENTS...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1209 PM EDT THU MAY 30 2013
.SYNOPSIS...
HIGH PRESSURE WILL LINGER ACROSS THE CENTRAL ATLANTIC INTO THIS
WEEKEND, BRINGING INCREASING HEAT AND HUMIDITY TO THE MID ATLANTIC
STATES. EARLY NEXT WEEK, A LOW PRESSURE SYSTEM EMERGING FROM THE
GREAT LAKES WILL SEND A COLD FRONT THROUGH OUR REGION BY MONDAY.
HIGH PRESSURE SPREADING SOUTH FROM CENTRAL CANADA IS THEN EXPECTED
TO BUILD TOWARD OUR REGION THROUGH MID WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO SIGNIFICANT CHANGES WILL BE MADE WITH THE NEXT ESTF. LOOKS LIKE
THERE IS A BIT OF A SHORT WAVE ON THE WATER VAPOR IMAGERY AND CU
WEST OF US LOOK A BIT MORE ROBUST THAN THEY WERE AT THIS TIME YESTERDAY.
BASED ON THE 12Z SOUNDINGS, WE NUDGED MAX TEMPS EVER SO SLIGHTLY
HIGHER AND PROGRESSED THEM UPWARD A BIT FASTER. MAX HEAT INDICES
ARE IN THE LOWER 90S. TEMPERATURES NEAR THE WATER SHOULD BE
SEVERAL DEGREES COOLER THAN INLAND.
LATEST MESOSCALE MODELS RUN CONTINUE TO SUPPORT THE THINKING OF
ISOLATED OR SLIGHT CHANCE CONVECTION LATER TODAY NORTHWEST. 12Z
SOUNDINGS SHOW IAD AND APG AS CAPPED, BUT CAPPING NOT AS STRONG AT
SITES FARTHER TO THE NORTH AND CONVECTIVE TEMP EXPECTED TO BE
REACHED.
ON POPS, THE MID LEVEL RIDGE DOES BUILD TODAY OVER OUR AREA, AND A
RELATIVELY DRY SOUNDING DOES RESULT IN A RATHER HIGH LFC. HOWEVER,
WE THINK WE END UP WITH SOME CAPE AND NOT A LOT OF CIN DURING THE
AFTERNOON EVEN AFTER ADJUSTING FOR LOWER DEW POINTS. ALSO, THERE
SEEMS TO BE SOME WEAK ENERGY MOVING ALONG THE SKIRT OF THE RIDGE
THAT IS WEAKLY APPARENT ON WATER VAPOR IMAGERY AND THAT COULD WORK
WITH THE INSTABILITY TO TRIGGER CONVECTION. SPC HAS ALMOST THE
ENTIRE AREA UNDER A GENERAL RISK OF CONVECTION TODAY; WE JUST PUT
SLIGHT CHANCE POPS BACK INTO THE AREA NORTHWEST OF THE FALL LINE.
ON WINDS, WE SHOULD SEE A SOUTHWEST TO WEST WIND THAT PEAKS A BIT
ABOVE 10 MPH TODAY. THE H925 WINDS ARE IN OPPOSITION TO ANY SEA/BAY
BREEZE AND FORECAST TO BE AROUND 15 KT. THAT IS RIGHT ON THE EDGE OF
STOPPING IT FROM MAKING MUCH PROGRESS INLAND. SINCE THE LAND/WATER
TEMPERATURE DISCONTINUITY IS GOING TO BE CONSIDERABLE, WE DID
FORECAST IT TO MAKE A LITTLE MORE PROGRESS INLAND THAN WE MIGHT HAVE
LATER IN THE WARM SEASON. WE AREN`T FORECASTING ANY CONVECTION WITH
THE SEA BREEZE AT THIS POINT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
WHATEVER ENERGY IS AVAILABLE TO TRIGGER ANYTHING SHOULD BE GONE BY
DUSK, AND WE CARRY A DRY THURSDAY NIGHT. THE WINDS MAY DIE OFF A BIT
MORE QUICKLY THAN THEY DID EARLY THIS MORNING, AND SO WE ALLOW FOR A
BIT MORE RADIATING AND LEAN MODESTLY TOWARD COOLER GUIDANCE. WE
DON`T CARRY ANY FOG OR HAZE IN THIS FORECAST.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
FOR THE FIRST PART OF THE LONG TERM PERIOD, OUR REGION WILL BE IN
THE MIDST OF THE FIRST HEAT WAVE OF THE SEASON AS SURFACE HIGH
PRESSURE WILL BE FOUND TO OUR EAST ACROSS THE CENTRAL ATLANTIC, WITH
STRONG MID-LEVEL RIDGING ALOFT. THIS WILL PROMOTE AN INCREASING
SOUTHWESTERLY FLOW THROUGH THE MID ATLANTIC REGION, WITH 850MB AND
925MB MODEL TEMPERATURE DATA SUPPORTING MAXIMUM TEMPERATURES ACROSS
THE FORECAST AREA REACHING THE LOWER 90S FRIDAY AND FOR MUCH OF THE
AREA AGAIN ON SATURDAY. DEWPOINTS THROUGH THIS TIME FRAME WILL
MAINLY BE IN THE LOWER TO PERHAPS MIDDLE 60S, YIELDING HEAT INDEX
VALUES IN THE LOWER 90S EACH AFTERNOON. WE WILL CONTINUE A MENTION
IN OUR HAZARDOUS WEATHER OUTLOOK HIGHLIGHTING THIS MULTI-DAY HOT AND
SOMEWHAT MUGGY AIRMASS.
GOING INTO SUNDAY, THIS OVERALL PATTERN WILL BEGIN TO BREAK DOWN, AS
SURFACE HIGH PRESSURE WILL DRIFT FARTHER EAST INTO THE CENTRAL
ATLANTIC AND THE MID-LEVEL RIDGE WILL ALSO BEGIN TO PUSH OFFSHORE.
MEANWHILE, AN AREA OF LOW PRESSURE WILL BE EMERGING FROM AROUND THE
GREAT LAKES SUNDAY AND TRACKING INTO SOUTHEASTERN CANADA THROUGH
MONDAY, ALLOWING A TRAILING COLD FRONT TO APPROACH OUR REGION FROM
THE NORTHWEST. THERE LOOKS TO BE AMPLE INSTABILITY AND LOW LEVEL
MOISTURE IN PLACE AHEAD OF THE APPROACHING FRONTAL BOUNDARY FOR
POTENTIALLY STRONG CONVECTIVE ACTIVITY, AND WE STEADILY INCREASE
POPS FROM NORTHWEST TO SOUTHEAST THROUGH THE COURSE OF SUNDAY INTO
SUNDAY NIGHT. MODEL DIFFERENCES STILL EXIST BETWEEN THE ECMWF, GFS,
AND OTHERS REGARDING THE TIMING OF THE FRONTAL PASSAGE THROUGH THE
REGION MONDAY, AND WITH THIS UNCERTAINTY IN MIND, WE HAVE KEPT HIGH
CHANCE TO LIKELY POPS IN PLACE FOR THE BETTER PART OF MONDAY ACROSS
THE FORECAST AREA FOR SCATTERED SHWR/T-STORM ACTIVITY. FOLLOWING THE
FRONTAL PASSAGE, THERE IS FAIRLY GOOD MODEL AGREEMENT AS AN AREA OF
HIGH PRESSURE FROM CENTRAL CANADA IS PROGGED TO SPREAD SOUTH AND
EAST FROM THE LATTER PART OF MONDAY THROUGH THE MID-WEEK PERIOD.
THIS WILL BRING A NOTICEABLE CHANGE IN AIRMASS TO OUR REGION, WITH
MAXIMUM TEMPERATURES RETURNING TO MORE SEASONAL LEVELS.
&&
.AVIATION /16Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
WE AREN`T FORECASTING ANY CEILINGS THROUGH THE TAF PERIOD. SOME VFR
CUMULUS IS FORECAST FOR TODAY. WE CAN`T RULE CONVECTION OUT
COMPLETELY, BUT THE PROBABILITY OF IT AS OF THIS WRITING IS TOO LOW
TO CARRY IN THE TAFS.
WINDS ARE FORECAST TO BE FROM THE SOUTHWEST TO WEST AND PICK UP TO
AROUND OR A BIT ABOVE 10 KT AFTER DAYBREAK. WHETHER A SEA/BAY BREEZE
MAKES IT TO ACY, MIV AND ILG IS UNCERTAIN. GIVEN THE EXPECTED STRONG
TEMPERATURE DIFFERENCE BETWEEN THE WATER AND INLAND AND THE WINDS
ABOVE THE SURFACE, WE FORECAST A BRIEF PERIOD LATE THIS AFTERNOON
AND EARLY THIS EVENING WHEN WINDS AT ACY AND ILG COME AROUND TO
SOUTH. CONFIDENCE IN THAT IS MODERATE AT BEST.
OUTLOOK...
FRIDAY AND SATURDAY...MAINLY VFR CONDITIONS WITH SOUTHWESTERLY
WINDS. SOME LOCAL REDUCED VSBYS POSSIBLE EACH MORNING IN HAZE.
SUNDAY AND MONDAY...MOSTLY VFR, EXCEPT TIMES OF POSSIBLE IFR/MVFR IN
SCATTERED SHWRS/T-STORMS, ESPECIALLY FROM SUNDAY AFTN THROUGH MONDAY
MORNING.
&&
.MARINE...
A MARINE LAYER SHOULD BE FAIRLY STRONG TODAY. WINDS ABOVE THE
SURFACE ARE NOT FORECAST TO BE THAT ROBUST, SO WE ARE FORECASTING A
SOUTHWEST WIND THAT IS NOTICEABLE BUT BELOW THE ADVISORY CRITERION.
A SEA/BAY BREEZE MAY MAKE MODEST PROGRESS OUT FROM THE COASTLINE AND
UP THE BAY, AND WINDS THERE MAY COME AROUND TO SOUTH. GIVEN THE
LATER HRRR WE WERE SLIGHTLY MORE AGGRESSIVE BRINGING A BAY BREEZE
UP THE DELAWARE.
SEAS WERE RUNNING AROUND 3 FT OVER THE ATLANTIC WATERS EARLY THIS
MORNING. AS THE PREVIOUS FORECASTER NOTED, WAVE WATCH GUIDANCE IS
VERIFYING TOO HIGH WITH SWELLS. WE CARRY SUB-ADVISORY SEAS THROUGH
THE TONIGHT.
OUTLOOK...
SUB-SCA CONDITIONS EXPECTED FOR OUR WATERS THROUGH FRIDAY AND MOST
OF SATURDAY AS AN AREA OF HIGH PRESSURE LINGERS ACROSS THE CENTRAL
ATLANTIC. BY SATURDAY NIGHT AND INTO SUNDAY, HIGH PRESSURE WILL BE
DRIFTING FARTHER EAST AND AWAY FROM THE REGION, WITH A COLD FRONT
APPROACHING THE AREA FROM THE NORTHWEST DURING SUNDAY. WE ANTICIPATE
WIND GUSTS AND SEAS TO REACH SMALL CRAFT ADVISORY LEVELS DURING THIS
TIME FRAME, AND THESE CONDITIONS WILL MOST LIKELY LAST INTO MONDAY,
AS WELL. SCATTERED SHWRS AND T-STORMS WILL ALSO REDUCE VISIBILITIES
FROM LATE SUNDAY THROUGH MONDAY FOR OUR WATERS, AS THE FRONT
APPROACHES AND TRACKS THROUGH THE REGION.
&&
.RIP CURRENTS...
WE CARRY A LOW PROBABILITY OF RIP CURRENTS TODAY.
RIP CURRENT AWARENESS WEEK IS JUNE 2 THROUGH 8.
PSA`S WILL AIR ON KPHI NWR AND POST DAILY AROUND 545 AM. THERE
WILL BE A SHORT AWARENESS PRESS CONFERENCE IN SURF CITY, LBI ON
TUE JUNE 4 AT 2 PM FOR THOSE MEDIA REPRESENTATIVES WHO ARE
INTERESTED IN RAISING RIP CURRENT AWARENESS AND IN CONDITIONS
FAVORING LIFE THREATENING DANGER IN THE UNGUARDED OCEAN SURF ZONE.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KLINE
NEAR TERM...DELISI/GIGI
SHORT TERM...DELISI
LONG TERM...KLINE
AVIATION...DELISI/KLINE
MARINE...DELISI/KLINE
RIP CURRENTS...GIGI
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
539 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 22Z...
* APPROACHING LINE OF STORMS / LARGE OW ECHO ON WEATHER RADAR /
EXPECTED TO ACCELERATE ACROSS NORTHERN ILLINOIS THIS EVENING.
* GUST FRONT AHEAD OF LINE OF STORMS MAY PRODUCE DAMAGING WIND
GUSTS... IN ADDITIONAL TO BRIEF TORRENTIAL RAINFALL.
* ONGOING SCATTERED THUNDERSTORMS CONTINUING ALTHOUGH DECREASING
IN COVERAGE INTO THE EVENING AHEAD OF APPROACHING LINE OF
STORMS.
ED F
//DISCUSSION...UPDATED 18Z...
AN ACTIVE PERIOD IS EXPECTED WITH SEVERAL BOUTS OF THUNDERSTORMS
POSSIBLE AND GUSTY SOUTHERLY WINDS.
SYNOPTICALLY...AREA OF LOW PRESSURE LIES OVER THE NORTHERN PLAIN AND
WILL GRADUALLY SHIFT NORTHEAST THROUGH THE TAF PERIOD. NORTHERN
ILLINOIS LIES IN A TIGHT SOUTHERLY GRADIENT WITH WINDS GUSTING TO
AROUND 30 KT ALREADY EARLY THIS AFTERNOON AND EXPECTED TO PERSIST
THROUGH THE DAY. WINDS MAY TAPER SOME WITH SUNSET...THEN ARE
EXPECTED TO BECOME GUSTY AGAIN FRIDAY...THOUGH NOT QUITE AS STRONG
AS TODAY.
SEVERAL ROUNDS OF THUNDERSTORMS ARE POSSIBLE...WITH THE DETAILS
STILL A BIT MURKY. FIRST ROUND IS ALREADY STARTING TO TAKE SHAPE
THIS AFTERNOON AS STRONG INSTABILITY HAS DEVELOPED OVER THE AREA
WITH CONVECTION ALREADY DEVELOPING DOWNSTATE AHEAD OF A NEGATIVELY
TILTED TROUGH LIFTING ACROSS THE MID MISSISSIPPI VALLEY. THIS WAVE
WILL CONTINUE NORTHEAST INTO NORTHERN ILLINOIS MID AFTERNOON WITH
SCATTERED STRONG TO SEVERE THUNDERSTORMS EXPECTED OVER THE AREA.
WITH NO SIGNIFICANT LOW LEVEL BOUNDARIES OR FOCUSING MECHANISMS...IT
WILL BE HARD TO IMPOSSIBLE TO PINPOINT EXACTLY WHERE THUNDERSTORMS
WILL DEVELOP...THOUGH THE BEST INSTABILITY HAS SET UP JUST WEST OF
THE CHICAGO TERMINALS. THEN THIS EVENING...NUMEROUS CONVECTIVE
ALLOWING MODELS ARE INDICATING THAT A SECOND ROUND OF CONVECTION
WILL CONGEAL INTO A LINE OFF TO OUR WEST WITH THE DEVELOPMENT OF A
MODERATE TO STRONG LOW LEVEL JET ALONG THE MISSISSIPPI RIVER VALLEY.
THIS LINE IS EXPECTED TO RACE EAST LATE THIS EVENING OR EARLY
OVERNIGHT. FINALLY...WITH SIMILAR CONDITIONS IN PLACE
TOMORROW...WILL BE LOOKING AT MUCH OF THE SAME CONCERNS FRIDAY WITH
RESPECT TO PERIODIC CONVECTIVE CHANCES.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM TO HIGH CONFIDENCE IN SCATTERED TSTMS CONTINUING THROUGH
THE EVENING... BUT WITH DECREASE IN COVERAGE OF SCATTERED CELLS
IN ADVANCE OF LARGE LINE OF STORMS.
* 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 03Z.
* 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
510 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 20Z...
* ONGOING SCATTERED CONVECTION CONTINUING THROUGH THE EVENING AND
OVERNIGHT.
* COVERAGE OF TSTMS GRADUALLY INCREASING THROUGH REMAINDER OF
AFTERNOON.
* INDIVIDUAL STORMS PULSING UP AND DOWN HAVE POTENTIAL TO PRODUCE
SURFACE WIND GUSTS TO 50 KTS.
ED F
//DISCUSSION...UPDATED 18Z...
AN ACTIVE PERIOD IS EXPECTED WITH SEVERAL BOUTS OF THUNDERSTORMS
POSSIBLE AND GUSTY SOUTHERLY WINDS.
SYNOPTICALLY...AREA OF LOW PRESSURE LIES OVER THE NORTHERN PLAIN AND
WILL GRADUALLY SHIFT NORTHEAST THROUGH THE TAF PERIOD. NORTHERN
ILLINOIS LIES IN A TIGHT SOUTHERLY GRADIENT WITH WINDS GUSTING TO
AROUND 30 KT ALREADY EARLY THIS AFTERNOON AND EXPECTED TO PERSIST
THROUGH THE DAY. WINDS MAY TAPER SOME WITH SUNSET...THEN ARE
EXPECTED TO BECOME GUSTY AGAIN FRIDAY...THOUGH NOT QUITE AS STRONG
AS TODAY.
SEVERAL ROUNDS OF THUNDERSTORMS ARE POSSIBLE...WITH THE DETAILS
STILL A BIT MURKY. FIRST ROUND IS ALREADY STARTING TO TAKE SHAPE
THIS AFTERNOON AS STRONG INSTABILITY HAS DEVELOPED OVER THE AREA
WITH CONVECTION ALREADY DEVELOPING DOWNSTATE AHEAD OF A NEGATIVELY
TILTED TROUGH LIFTING ACROSS THE MID MISSISSIPPI VALLEY. THIS WAVE
WILL CONTINUE NORTHEAST INTO NORTHERN ILLINOIS MID AFTERNOON WITH
SCATTERED STRONG TO SEVERE THUNDERSTORMS EXPECTED OVER THE AREA.
WITH NO SIGNIFICANT LOW LEVEL BOUNDARIES OR FOCUSING MECHANISMS...IT
WILL BE HARD TO IMPOSSIBLE TO PINPOINT EXACTLY WHERE THUNDERSTORMS
WILL DEVELOP...THOUGH THE BEST INSTABILITY HAS SET UP JUST WEST OF
THE CHICAGO TERMINALS. THEN THIS EVENING...NUMEROUS CONVECTIVE
ALLOWING MODELS ARE INDICATING THAT A SECOND ROUND OF CONVECTION
WILL CONGEAL INTO A LINE OFF TO OUR WEST WITH THE DEVELOPMENT OF A
MODERATE TO STRONG LOW LEVEL JET ALONG THE MISSISSIPPI RIVER VALLEY.
THIS LINE IS EXPECTED TO RACE EAST LATE THIS EVENING OR EARLY
OVERNIGHT. FINALLY...WITH SIMILAR CONDITIONS IN PLACE
TOMORROW...WILL BE LOOKING AT MUCH OF THE SAME CONCERNS FRIDAY WITH
RESPECT TO PERIODIC CONVECTIVE CHANCES.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN TSTMS CONTINUING THROUGH THE EVENING WITH
GENERAL INCREASING TREND IN COVERAGE.
* LOW CONFIDENCE IN TIMING OF ANY SPECIFIC TSTM CELLS AT SPECIFIC
TERMINALS.
* MEDIUM CONFIDENCE IN LINE OF TSTMS IMPACTING TERMINALS LATE
THIS EVENING.
* 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
401 PM CDT THU MAY 30 2013
.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 20Z...
* ONGOING SCATTERED CONVECTION CONTINUING THROUGH THE EVENING AND
OVERNIGHT.
* COVERAGE OF TSTMS GRADUALLY INCREASING THROUGH REMAINDER OF
AFTERNOON.
* INDIVIDUAL STORMS PULSING UP AND DOWN HAVE POTENTIAL TO PRODUCE
SURFACE WIND GUSTS TO 50 KTS.
ED F
//DISCUSSION...UPDATED 18Z...
AN ACTIVE PERIOD IS EXPECTED WITH SEVERAL BOUTS OF THUNDERSTORMS
POSSIBLE AND GUSTY SOUTHERLY WINDS.
SYNOPTICALLY...AREA OF LOW PRESSURE LIES OVER THE NORTHERN PLAIN AND
WILL GRADUALLY SHIFT NORTHEAST THROUGH THE TAF PERIOD. NORTHERN
ILLINOIS LIES IN A TIGHT SOUTHERLY GRADIENT WITH WINDS GUSTING TO
AROUND 30 KT ALREADY EARLY THIS AFTERNOON AND EXPECTED TO PERSIST
THROUGH THE DAY. WINDS MAY TAPER SOME WITH SUNSET...THEN ARE
EXPECTED TO BECOME GUSTY AGAIN FRIDAY...THOUGH NOT QUITE AS STRONG
AS TODAY.
SEVERAL ROUNDS OF THUNDERSTORMS ARE POSSIBLE...WITH THE DETAILS
STILL A BIT MURKY. FIRST ROUND IS ALREADY STARTING TO TAKE SHAPE
THIS AFTERNOON AS STRONG INSTABILITY HAS DEVELOPED OVER THE AREA
WITH CONVECTION ALREADY DEVELOPING DOWNSTATE AHEAD OF A NEGATIVELY
TILTED TROUGH LIFTING ACROSS THE MID MISSISSIPPI VALLEY. THIS WAVE
WILL CONTINUE NORTHEAST INTO NORTHERN ILLINOIS MID AFTERNOON WITH
SCATTERED STRONG TO SEVERE THUNDERSTORMS EXPECTED OVER THE AREA.
WITH NO SIGNIFICANT LOW LEVEL BOUNDARIES OR FOCUSING MECHANISMS...IT
WILL BE HARD TO IMPOSSIBLE TO PINPOINT EXACTLY WHERE THUNDERSTORMS
WILL DEVELOP...THOUGH THE BEST INSTABILITY HAS SET UP JUST WEST OF
THE CHICAGO TERMINALS. THEN THIS EVENING...NUMEROUS CONVECTIVE
ALLOWING MODELS ARE INDICATING THAT A SECOND ROUND OF CONVECTION
WILL CONGEAL INTO A LINE OFF TO OUR WEST WITH THE DEVELOPMENT OF A
MODERATE TO STRONG LOW LEVEL JET ALONG THE MISSISSIPPI RIVER VALLEY.
THIS LINE IS EXPECTED TO RACE EAST LATE THIS EVENING OR EARLY
OVERNIGHT. FINALLY...WITH SIMILAR CONDITIONS IN PLACE
TOMORROW...WILL BE LOOKING AT MUCH OF THE SAME CONCERNS FRIDAY WITH
RESPECT TO PERIODIC CONVECTIVE CHANCES.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN TSTMS CONTINUING THROUGH THE EVENING WITH
GENERAL INCREASING TREND IN COVERAGE.
* LOW CONFIDENCE IN TIMING OF ANY SPECIFIC TSTM CELLS AT SPECIFIC
TERMINALS.
* MEDIUM CONFIDENCE IN LINE OF TSTMS IMPACTING TERMINALS LATE
THIS EVENING.
* 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...ILZ019-ILZ032...7 PM THURSDAY TO 7 PM
SATURDAY.
IN...NONE.
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:
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WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
329 PM CDT THU MAY 30 2013
.DISCUSSION...
326 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...COMING SOON.
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* ONGOING SCATTERED CONVECTION CONTINUING THROUGH THE EVENING AND
OVERNIGHT.
* COVERAGE OF TSTMS GRADUALLY INCREASING THROUGH REMAINDER OF
AFTERNOON.
* INDIVIDUAL STORMS PULSING UP AND DOWN HAVE POTENTIAL TO PRODUCE
SURFACE WIND GUSTS TO 50 KTS.
ED F
//DISCUSSION...UPDATED 18Z...
AN ACTIVE PERIOD IS EXPECTED WITH SEVERAL BOUTS OF THUNDERSTORMS
POSSIBLE AND GUSTY SOUTHERLY WINDS.
SYNOPTICALLY...AREA OF LOW PRESSURE LIES OVER THE NORTHERN PLAIN AND
WILL GRADUALLY SHIFT NORTHEAST THROUGH THE TAF PERIOD. NORTHERN
ILLINOIS LIES IN A TIGHT SOUTHERLY GRADIENT WITH WINDS GUSTING TO
AROUND 30 KT ALREADY EARLY THIS AFTERNOON AND EXPECTED TO PERSIST
THROUGH THE DAY. WINDS MAY TAPER SOME WITH SUNSET...THEN ARE
EXPECTED TO BECOME GUSTY AGAIN FRIDAY...THOUGH NOT QUITE AS STRONG
AS TODAY.
SEVERAL ROUNDS OF THUNDERSTORMS ARE POSSIBLE...WITH THE DETAILS
STILL A BIT MURKY. FIRST ROUND IS ALREADY STARTING TO TAKE SHAPE
THIS AFTERNOON AS STRONG INSTABILITY HAS DEVELOPED OVER THE AREA
WITH CONVECTION ALREADY DEVELOPING DOWNSTATE AHEAD OF A NEGATIVELY
TILTED TROUGH LIFTING ACROSS THE MID MISSISSIPPI VALLEY. THIS WAVE
WILL CONTINUE NORTHEAST INTO NORTHERN ILLINOIS MID AFTERNOON WITH
SCATTERED STRONG TO SEVERE THUNDERSTORMS EXPECTED OVER THE AREA.
WITH NO SIGNIFICANT LOW LEVEL BOUNDARIES OR FOCUSING MECHANISMS...IT
WILL BE HARD TO IMPOSSIBLE TO PINPOINT EXACTLY WHERE THUNDERSTORMS
WILL DEVELOP...THOUGH THE BEST INSTABILITY HAS SET UP JUST WEST OF
THE CHICAGO TERMINALS. THEN THIS EVENING...NUMEROUS CONVECTIVE
ALLOWING MODELS ARE INDICATING THAT A SECOND ROUND OF CONVECTION
WILL CONGEAL INTO A LINE OFF TO OUR WEST WITH THE DEVELOPMENT OF A
MODERATE TO STRONG LOW LEVEL JET ALONG THE MISSISSIPPI RIVER VALLEY.
THIS LINE IS EXPECTED TO RACE EAST LATE THIS EVENING OR EARLY
OVERNIGHT. FINALLY...WITH SIMILAR CONDITIONS IN PLACE
TOMORROW...WILL BE LOOKING AT MUCH OF THE SAME CONCERNS FRIDAY WITH
RESPECT TO PERIODIC CONVECTIVE CHANCES.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN TSTMS CONTINUING THROUGH THE EVENING WITH
GENERAL INCREASING TREND IN COVERAGE.
* LOW CONFIDENCE IN TIMING OF ANY SPECIFIC TSTM CELLS AT SPECIFIC
TERMINALS.
* MEDIUM CONFIDENCE IN LINE OF TSTMS IMPACTING TERMINALS LATE
THIS EVENING.
* 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...ILZ019-ILZ032...7 PM THURSDAY TO 7 PM
SATURDAY.
IN...NONE.
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
322 PM CDT THU MAY 30 2013
.MESOSCALE DISCUSSION...
309 PM CDT
SCATTERED THUNDERSTORMS CONTINUE TO FIRE ACROSS THE REGION. LACK OF
LOW LEVEL CONVERGENCE AND ANY CONVECTIVE INHIBITION ALONG WITH
INCREASING LARGE SCALE ASCENT AHEAD OF APPROACHING SHORT WAVE
EVIDENT ON WATER VAPOR IMAGERY MOVING INTO WESTERN ILLINOIS SHOULD
CONTINUE TO ALLOW THIS REGIME WITH STORMS GOING UP JUST ABOUT
ANYWHERE.
WIND PROFILERS SHOW A PRETTY TIGHT GRADIENT IN MID LEVEL FLOW WITH
PROFILERS SHOWING 55-60KT WINDS AT 6KM OVER WESTERN ILLINOIS INTO
IA/MO WITH ONLY ABOUT 40KT OF FLOW OVER OUR AREA. UNIDIRECTIONAL
NATURE OF THE FLOW IS MINIMIZING DEEP LAYER SHEAR OVER OUR EASTERN
CWA WITH ABOUT DEEP LAYER SHEAR ABOUT 20-30KT INCREASING TO AROUND
40KT WESTERN CWA. RAP SUGGESTS THAT THE STRONGER SHEAR WILL SPREAD
EASTWARD ACROSS THE CWA THIS EVENING.
LOW LEVEL SHEAR IS NOT OVERLY STRONG AT THIS TIME WITH WELL MIXED
BOUNDARY LAYER...HOWEVER T/TD SPREADS ARE IN THE NEIGHBORHOOD OF
10-15F SO LCL HEIGHTS ARE NOT THAT HIGH SUGGESTING AT LEAST SOME
LIMITED TORNADO THREAT FOR THE NEXT HOUR OR TWO. THIS WILL
PARTICULARLY BE THE CASE WITH ANY CELLS THAT ARE ABLE TO ACHIEVE
MORE DEVIANT RIGHTWARD MOTION AUGMENTING THE LOW LEVEL SHEAR.
LOW LEVEL SHEAR SHOULD INCREASE THIS EVENING WITH DEVELOPMENT OF LOW
LEVEL WIND MAXIMA...SO ASSUMING CONVECTION REMAINS CELLULAR AND
ROOTED IN THE BOUNDARY LAYER THEN TORNADO THREAT COULD INCREASE SOME
FOR A TIME EARLY THIS EVENING. IN THE NEXT HOUR OR TWO THINK THE
PRIMARY HAZARD WILL BE DMG WIND AND HAIL...WITH A SLIGHT TORNADO
THREAT MOSTLY OVER WESTERN CWA.
IZZI
&&
.DISCUSSION...
326 AM CDT
CONVECTIVE TRENDS AND ASSOCIATED HEAVY RAIN AND SEVERE WEATHER
THREAT REMAIN THE FOCUS OF THE FORECAST THIS PERIOD. UPPER AIR
ANALYSIS AND EARLY MORNING WATER VAPOR IMAGERY SHOW A MUCH MORE
AMPLIFIED PATTERN THAN LAST NIGHT WITH A BROAD RIDGE OVER THE
EASTERN THIRD OR SO OF THE COUNTRY WITH A RIDGE AXIS EXTENDING FROM
NORTHERN OHIO TO THE CANADIAN PRAIRIES. THE BASE OF A LONGWAVE
TROUGH IS POSITIONED OVER THE FAR SOUTHERN PLAINS WITH THE AXIS
EXTENDING NORTHWEST TO A CLOSED LOW SPINNING OFF THE BRITISH
COLUMBIA COAST. SEVERAL SHORTWAVES ARE EMBEDDED WITHIN THE
SOUTH-SOUTHWEST FLOW OVER THE CENTER OF THE COUNTRY. AT THE
SURFACE...ONE LOW PRESSURE AREA IS POSITIONED OVER SOUTH DAKOTA WITH
A SECOND OVER THE TX/OK PANHANDLE. A COLD FRONT IS STRETCHED BETWEEN
THESE TWO LOWS WITH A WARM FRONTAL BOUNDARY FROM SOUTH DAKOTA ACROSS
FAR NORTHERN LAKE MICHIGAN.
TODAY THROUGH FRIDAY...AN UPPER LEVEL LOW WILL CLOSE OFF OVER THE
WESTERN DAKOTAS TODAY AS THE MAIN LONGWAVE AXIS PIVOTS NORTHWARD
ACROSS THE CENTRAL/SOUTHERN PLAINS AND MID MISSISSIPPI RIVER VALLEY.
THIS WILL DEEPEN THE SURFACE LOW ACROSS THE DAKOTAS AND HELP PUSH
THE ATTENDANT COLD FRONT INTO FAR WESTERN MINNESOTA AND IOWA BY
EVENING. THERE ARE A RANGE OF POSSIBILITIES WITH REGARD TO
CONVECTIVE EVOLUTION INTO TONIGHT GIVEN THE UPPER FLOW PATTERN AND
PRESENCE OF NUMEROUS EMBEDDED WAVES. WATER VAPOR SHOWS THE LONGWAVE
TROUGH AXIS PIVOTING NORTHEASTWARD ACROSS TX/OK AS IT IS BEING
PUSHED BY A STRONG UPPER JET CORE ON ITS WESTERN FLANK. THE MAIN
TROUGH ITSELF IS THE MOST COHERENT FOCUS FOR CONVECTIVE
DEVELOPMENT...IN ADDITION TO THE NUMEROUS EMBEDDED WAVES. WITH THE
STEERING FLOW PRETTY SELY THIS MORNING...THIS WILL INITIALLY KEEP
ACTIVITY ON A TRAJECTORY WEST OF THE CWA BUT WITH THE MAIN LONGWAVE
TROUGH SHIFTING EASTWARD AS AN UPPER JET MAX PUSHES IT FROM THE WEST
THE MAIN CORRIDOR OF FLOW WILL TRANSLATE EASTWARD SPREADING
CONVECTIVE CHANCES FURTHER INTO THE AREA. CHANCES FOR STORMS WILL
THEREFORE INCREASE FROM WEST TO EAST THROUGH THE DAY...WITH MINIMAL
CHANCES THROUGH LATE MORNING THOUGH THERE IS SUGGESTION OF SOME
SCATTERED DEVELOPMENT THANKS TO A WEAK UPPER WAVE THAT AT THIS POINT
IS NOT REALLY WELL DEFINED ON SATELLITE AND ONLY GENERATING CLOUD
COVER WHICH IS MOVING NORTHWARD INTO SOUTHERN ILLINOIS. BEYOND THIS
MORNING...TOUGH TO PINPOINT SPECIFIC CONVECTIVE EPISODES BUT IT
APPEARS THAT ACTIVITY TO THE SOUTHWEST WILL SPREAD INTO THE CWA LATE
THIS AFTERNOON OR EARLY THIS EVENING...THOUGH AGAIN...IT MAY BE
PRECEDED BY LESS FOCUSED ACTIVITY. ADDITIONAL ROUNDS OF STORMS MAY
CONTINUE THROUGH THE OVERNIGHT. BY FRIDAY MORNING...THE SURFACE AND
UPPER LOWS WILL HAVE MOVED LITTLE BUT THE UPPER LOW WILL HAVE
SEVERAL SPOKES OF ENERGY ROTATING AROUND IT. THERE IS GOOD MODEL
AGREEMENT IN A SHORTWAVE DEVELOPING OVER THE CENTRAL/SOUTHERN
ROCKIES EARLY FRIDAY THEN LIFTING NORTHEASTWARD DURING THE DAY AND
BRINGING ANOTHER ROUND OF ORGANIZED STORMS EITHER LATE FRIDAY
MORNING OR EARLY AFTERNOON.
IN TERMS OF THREATS...PRECIPITABLE WATER VALUES OF AROUND 1.8 INCHES
WILL SUPPORT A HEAVY RAIN THREAT TODAY AND TONIGHT WITH A
BRIEF LOWERING OF VALUES FRIDAY MORNING AS DRIER MID LEVEL AIR WORKS
IN BEHIND THE DEPARTING TROUGH. HOWEVER...ANOTHER PUSH OF HIGH PW
AIR WILL ARRIVE WITH THE NEXT EXPECTED WAVE BY FRIDAY AFTERNOON. THE
MAIN AREA OF CONCERN WILL BE THE WESTERN CWA GIVEN THAT THEY HAVE
THE BEST CHANCE OF BEING AFFECTED BY MULTIPLE ROUNDS OF CONVECTION
STARTING AS EARLY AS LATE THIS AFTERNOON. EACH OF THE WAVES SPAWNING
THE CONVECTION WILL BE PROGRESSIVE WHICH LOOKS TO LIMIT THE DURATION
OF HEAVY RAIN BUT 2 TO 3 INCHES BETWEEN NOW AND FRIDAY LOOKS
REASONABLE ON THE LARGE SCALE THOUGH ISOLATED HIGHER AMOUNTS ARE
CERTAINLY POSSIBLE. DECIDED TO GO WITH A FLASH FLOOD WATCH FOR LA
SALLE AND LIVINGSTON COUNTIES GIVEN THE 4-5+ INCHES OF RAINFALL
OBSERVED THERE OVER THE PAST FEW DAYS AND THE EXPECTED RAINFALL
ABOVE. AREAS TO THE NORTH HAVE SEEN FAR LESS RAINFALL SO POTENTIAL
IS LESS CERTAIN THERE AND 1 AND 3 HR FLASH FLOOD GUIDANCE VALUES ARE
1.6 AND 1.9 INCHES RESPECTIVELY AND HIGHER. AREAS TO THE EAST ALONG
THE I-80 CORRIDOR HAVE ALSO SEEN SIGNIFICANT RAINFALL THE PAST FEW
DAYS BUT STILL HAVE QUESTIONS HOW FAR EAST THE HEAVIEST RAINFALL
WILL STRETCH AND ALSO EXPECT A BIT LATER START TO THE BEST ORGANIZED
CONVECTION THERE. AN EXPANSION IS POSSIBLE HOWEVER. IN TERMS OF THE
SEVERE THREAT...STORMS THAT CAN DEVELOP PRIOR TO MID AFTERNOON WILL
HAVE SOME SEVERE THREAT WITH DECENT INSTABILITY AND SUFFICIENT DEEP
LAYER SHEAR FOR ORGANIZATION. AGAIN...THE FORCING DURING THIS PERIOD
IS SUBTLE AT BEST AT THIS POINT AND THERE IS SOME MINIMAL
CAPPING...SO FEEL CHANCES ARE PRETTY LOW. ONCE EVENING ARRIVES...THE
ODDS ARE BETTER THAT AN ORGANIZED CONVECTIVE COMPLEX OR COMPLEXES
WILL MOVE IN. HEAVY RAIN AND DAMAGING WINDS WILL BE THE MAIN
THREATS. SOME OF THE SEVERE THREAT MAY BE CONDITIONAL BASED ON HOW
THINGS DEVELOP UPSTREAM AND IF ANY LATE MORNING/EARLY AFTERNOON
CONVECTION CAN DEVELOP. SEVERE POTENTIAL MAY BE HIGHER FRIDAY
DEPENDING ON CONVECTIVE DEBRIS...BUT LOW LEVEL WIND FIELDS
STRENGTHEN WITH GREATER DEEP LAYER SHEAR AS WELL SO BETTER STORM
ORGANIZATION IS POSSIBLE. DAMAGING WIND/HAIL/ISOLATED TORNADO
THREATS MAY BE HIGHER. WARM AND MUGGY CONDITIONS WILL CONTINUE.
HIGHS TODAY WILL BE TOUGH WITH A BREEZY SOUTH-SOUTHWEST WIND
POINTING TOWARD WARMER READINGS BUT APPROACHING CLOUD COVER ARGUING
AGAINST. WILL CONTINUE WITH MID 80S WITH SOME POTENTIAL FOR HIGHER
VALUES IF CLOUD COVER IS LESS THAN EXPECTED. FRIDAY SHOULD BE
SLIGHTLY COOLER WITH MORE CLOUDS AND HIGHER DAYTIME PRECIP CHANCES.
SATURDAY THROUGH MID WEEK...AN UPPER TROUGH WILL MOVE SOUTHEAST
ACROSS NORTHERN ALBERTA/SASKATCHEWAN FRIDAY NIGHT AND PHASE WITH THE
CLOSED UPPER LOW OVER THE DAKOTAS. THIS WILL ALLOW THE LOW TO OPEN
UP AND THEN SWING SOUTHEASTWARD. IN TURN...THE SURFACE LOW WILL BE
KICKED EASTWARD AS WELL PUSHING THE COLD FRONT INTO THE AREA
SATURDAY. THIS WILL TRIGGER ADDITIONAL CHANCES FOR
CONVECTION...ESPECIALLY ACROSS THE EASTERN HALF OF THE FORECAST AREA
SATURDAY AFTERNOON AND EVENING. THE UPPER TROUGH CROSSES THE AREA
SATURDAY EVENING THOUGH CYCLONIC UPPER FLOW WILL CONTINUE THROUGH
SUNDAY. MUCH COOLER AIR WILL FLOW IN FROM THE NORTH WITH H85 TEMPS
FALLING FROM AROUND +16 TO +4 BY SUNDAY EVENING. SHOWER/ISOLD
THUNDER CHANCES WILL LINGER SUNDAY WITH THE CYCLONIC FLOW. HIGH
PRESSURE WILL SPREAD SOUTHWARD INTO THE PLAINS WHICH WILL PROVIDE
QUIET WEATHER MONDAY. MODEL GUIDANCE DIVERGES TUESDAY WITH HOW THE
UPPER FLOW PATTERN EVOLVES THOUGH IT DOES APPEAR THAT AT LEAST WEAK
UPPER RIDGING WILL MOVE ACROSS TUESDAY BRINGING WARMER MID LEVEL AIR
BUT TROUGHING RETURNS BY MID WEEK. PRECIP CHANCES MAY RETURN AS
EARLY AS TUESDAY EVENING DEPENDING ON HOW THE FLOW PATTERN PANS OUT
BUT GIVEN THE POTENTIAL FOR WAA TO BUILD AHEAD OF THE RIDGE OR AN
ACTIVE ZONAL PATTERN IF THE RIDGE IS WEAKER...SOME PRECIP IS
POSSIBLE. TEMPS WILL BE COOLER SUNDAY WITH HIGHS IN THE MID 60S
NORTH TO AROUND 70 SOUTH WITH MONDAY AND TUESDAY EACH BEING WARMER
THAN THE DAY BEFORE. FLOW OFF THE LAKE SUNDAY THROUGH TUESDAY WILL
KEEP LAKESHORE READINGS COOLER AND LAKE BREEZE DEVELOPMENT MAY
PROPEL COOLER TEMPS FURTHER INLAND EACH AFTERNOON.
MDB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* ONGOING SCATTERED CONVECTION CONTINUING THROUGH THE EVENING AND
OVERNIGHT.
* COVERAGE OF TSTMS GRADUALLY INCREASING THROUGH REMAINDER OF
AFTERNOON.
* INDIVIDUAL STORMS PULSING UP AND DOWN HAVE POTENTIAL TO PRODUCE
SURFACE WIND GUSTS TO 50 KTS.
ED F
//DISCUSSION...UPDATED 18Z...
AN ACTIVE PERIOD IS EXPECTED WITH SEVERAL BOUTS OF THUNDERSTORMS
POSSIBLE AND GUSTY SOUTHERLY WINDS.
SYNOPTICALLY...AREA OF LOW PRESSURE LIES OVER THE NORTHERN PLAIN AND
WILL GRADUALLY SHIFT NORTHEAST THROUGH THE TAF PERIOD. NORTHERN
ILLINOIS LIES IN A TIGHT SOUTHERLY GRADIENT WITH WINDS GUSTING TO
AROUND 30 KT ALREADY EARLY THIS AFTERNOON AND EXPECTED TO PERSIST
THROUGH THE DAY. WINDS MAY TAPER SOME WITH SUNSET...THEN ARE
EXPECTED TO BECOME GUSTY AGAIN FRIDAY...THOUGH NOT QUITE AS STRONG
AS TODAY.
SEVERAL ROUNDS OF THUNDERSTORMS ARE POSSIBLE...WITH THE DETAILS
STILL A BIT MURKY. FIRST ROUND IS ALREADY STARTING TO TAKE SHAPE
THIS AFTERNOON AS STRONG INSTABILITY HAS DEVELOPED OVER THE AREA
WITH CONVECTION ALREADY DEVELOPING DOWNSTATE AHEAD OF A NEGATIVELY
TILTED TROUGH LIFTING ACROSS THE MID MISSISSIPPI VALLEY. THIS WAVE
WILL CONTINUE NORTHEAST INTO NORTHERN ILLINOIS MID AFTERNOON WITH
SCATTERED STRONG TO SEVERE THUNDERSTORMS EXPECTED OVER THE AREA.
WITH NO SIGNIFICANT LOW LEVEL BOUNDARIES OR FOCUSING MECHANISMS...IT
WILL BE HARD TO IMPOSSIBLE TO PINPOINT EXACTLY WHERE THUNDERSTORMS
WILL DEVELOP...THOUGH THE BEST INSTABILITY HAS SET UP JUST WEST OF
THE CHICAGO TERMINALS. THEN THIS EVENING...NUMEROUS CONVECTIVE
ALLOWING MODELS ARE INDICATING THAT A SECOND ROUND OF CONVECTION
WILL CONGEAL INTO A LINE OFF TO OUR WEST WITH THE DEVELOPMENT OF A
MODERATE TO STRONG LOW LEVEL JET ALONG THE MISSISSIPPI RIVER VALLEY.
THIS LINE IS EXPECTED TO RACE EAST LATE THIS EVENING OR EARLY
OVERNIGHT. FINALLY...WITH SIMILAR CONDITIONS IN PLACE
TOMORROW...WILL BE LOOKING AT MUCH OF THE SAME CONCERNS FRIDAY WITH
RESPECT TO PERIODIC CONVECTIVE CHANCES.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN TSTMS CONTINUING THROUGH THE EVENING WITH
GENERAL INCREASING TREND IN COVERAGE.
* LOW CONFIDENCE IN TIMING OF ANY SPECIFIC TSTM CELLS AT SPECIFIC
TERMINALS.
* MEDIUM CONFIDENCE IN LINE OF TSTMS IMPACTING TERMINALS LATE
THIS EVENING.
* 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...ILZ019-ILZ032...7 PM THURSDAY TO 7 PM
SATURDAY.
IN...NONE.
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
309 PM CDT THU MAY 30 2013
.MESOSCALE DISCUSSION...
309 PM CDT
SCATTERED THUNDERSTORMS CONTINUE TO FIRE ACROSS THE REGION. LACK OF
LOW LEVEL CONVERGENCE AND ANY CONVECTIVE INHIBITION ALONG WITH
INCREASING LARGE SCALE ASCENT AHEAD OF APPROACHING SHORT WAVE
EVIDENT ON WATER VAPOR IMAGERY MOVING INTO WESTERN ILLINOIS SHOULD
CONTINUE TO ALLOW THIS REGIME WITH STORMS GOING UP JUST ABOUT
ANYWHERE.
WIND PROFILERS SHOW A PRETTY TIGHT GRADIENT IN MID LEVEL FLOW WITH
PROFILERS SHOWING 55-60KT WINDS AT 6KM OVER WESTERN ILLINOIS INTO
IA/MO WITH ONLY ABOUT 40KT OF FLOW OVER OUR AREA. UNIDIRECTIONAL
NATURE OF THE FLOW IS MINIMIZING DEEP LAYER SHEAR OVER OUR EASTERN
CWA WITH ABOUT DEEP LAYER SHEAR ABOUT 20-30KT INCREASING TO AROUND
40KT WESTERN CWA. RAP SUGGESTS THAT THE STRONGER SHEAR WILL SPREAD
EASTWARD ACROSS THE CWA THIS EVENING.
LOW LEVEL SHEAR IS NOT OVERLY STRONG AT THIS TIME WITH WELL MIXED
BOUNDARY LAYER...HOWEVER T/TD SPREADS ARE IN THE NEIGHBORHOOD OF
10-15F SO LCL HEIGHTS ARE NOT THAT HIGH SUGGESTING AT LEAST SOME
LIMITED TORNADO THREAT FOR THE NEXT HOUR OR TWO. THIS WILL
PARTICULARLY BE THE CASE WITH ANY CELLS THAT ARE ABLE TO ACHEIVE
MORE DEVIANT RIGHTWARD MOTION AUGMENTING THE LOW LEVEL SHEAR.
LOW LEVEL SHEAR SHOULD INCREASE THIS EVENING WITH DEVELOPMENT OF LOW
LEVEL WIND MAXIMA...SO ASSUMING CONVECTION REMAINS CELLULAR AND
ROOTED IN THE BOUNDARY LAYER THEN TORNADO THREAT COULD INCREASE SOME
FOR A TIME EARLY THIS EVENING. IN THE NEXT HOUR OR TWO THINK THE
PRIMARY HAZARD WILL BE DMG WIND AND HAIL...WITH A SLIGHT TORNADO
THREAT MOSTLY OVER WESTERN CWA.
IZZI
&&
.DISCUSSION...
326 AM CDT
CONVECTIVE TRENDS AND ASSOCIATED HEAVY RAIN AND SEVERE WEATHER
THREAT REMAIN THE FOCUS OF THE FORECAST THIS PERIOD. UPPER AIR
ANALYSIS AND EARLY MORNING WATER VAPOR IMAGERY SHOW A MUCH MORE
AMPLIFIED PATTERN THAN LAST NIGHT WITH A BROAD RIDGE OVER THE
EASTERN THIRD OR SO OF THE COUNTRY WITH A RIDGE AXIS EXTENDING FROM
NORTHERN OHIO TO THE CANADIAN PRAIRIES. THE BASE OF A LONGWAVE
TROUGH IS POSITIONED OVER THE FAR SOUTHERN PLAINS WITH THE AXIS
EXTENDING NORTHWEST TO A CLOSED LOW SPINNING OFF THE BRITISH
COLUMBIA COAST. SEVERAL SHORTWAVES ARE EMBEDDED WITHIN THE
SOUTH-SOUTHWEST FLOW OVER THE CENTER OF THE COUNTRY. AT THE
SURFACE...ONE LOW PRESSURE AREA IS POSITIONED OVER SOUTH DAKOTA WITH
A SECOND OVER THE TX/OK PANHANDLE. A COLD FRONT IS STRETCHED BETWEEN
THESE TWO LOWS WITH A WARM FRONTAL BOUNDARY FROM SOUTH DAKOTA ACROSS
FAR NORTHERN LAKE MICHIGAN.
TODAY THROUGH FRIDAY...AN UPPER LEVEL LOW WILL CLOSE OFF OVER THE
WESTERN DAKOTAS TODAY AS THE MAIN LONGWAVE AXIS PIVOTS NORTHWARD
ACROSS THE CENTRAL/SOUTHERN PLAINS AND MID MISSISSIPPI RIVER VALLEY.
THIS WILL DEEPEN THE SURFACE LOW ACROSS THE DAKOTAS AND HELP PUSH
THE ATTENDANT COLD FRONT INTO FAR WESTERN MINNESOTA AND IOWA BY
EVENING. THERE ARE A RANGE OF POSSIBILITIES WITH REGARD TO
CONVECTIVE EVOLUTION INTO TONIGHT GIVEN THE UPPER FLOW PATTERN AND
PRESENCE OF NUMEROUS EMBEDDED WAVES. WATER VAPOR SHOWS THE LONGWAVE
TROUGH AXIS PIVOTING NORTHEASTWARD ACROSS TX/OK AS IT IS BEING
PUSHED BY A STRONG UPPER JET CORE ON ITS WESTERN FLANK. THE MAIN
TROUGH ITSELF IS THE MOST COHERENT FOCUS FOR CONVECTIVE
DEVELOPMENT...IN ADDITION TO THE NUMEROUS EMBEDDED WAVES. WITH THE
STEERING FLOW PRETTY SELY THIS MORNING...THIS WILL INITIALLY KEEP
ACTIVITY ON A TRAJECTORY WEST OF THE CWA BUT WITH THE MAIN LONGWAVE
TROUGH SHIFTING EASTWARD AS AN UPPER JET MAX PUSHES IT FROM THE WEST
THE MAIN CORRIDOR OF FLOW WILL TRANSLATE EASTWARD SPREADING
CONVECTIVE CHANCES FURTHER INTO THE AREA. CHANCES FOR STORMS WILL
THEREFORE INCREASE FROM WEST TO EAST THROUGH THE DAY...WITH MINIMAL
CHANCES THROUGH LATE MORNING THOUGH THERE IS SUGGESTION OF SOME
SCATTERED DEVELOPMENT THANKS TO A WEAK UPPER WAVE THAT AT THIS POINT
IS NOT REALLY WELL DEFINED ON SATELLITE AND ONLY GENERATING CLOUD
COVER WHICH IS MOVING NORTHWARD INTO SOUTHERN ILLINOIS. BEYOND THIS
MORNING...TOUGH TO PINPOINT SPECIFIC CONVECTIVE EPISODES BUT IT
APPEARS THAT ACTIVITY TO THE SOUTHWEST WILL SPREAD INTO THE CWA LATE
THIS AFTERNOON OR EARLY THIS EVENING...THOUGH AGAIN...IT MAY BE
PRECEDED BY LESS FOCUSED ACTIVITY. ADDITIONAL ROUNDS OF STORMS MAY
CONTINUE THROUGH THE OVERNIGHT. BY FRIDAY MORNING...THE SURFACE AND
UPPER LOWS WILL HAVE MOVED LITTLE BUT THE UPPER LOW WILL HAVE
SEVERAL SPOKES OF ENERGY ROTATING AROUND IT. THERE IS GOOD MODEL
AGREEMENT IN A SHORTWAVE DEVELOPING OVER THE CENTRAL/SOUTHERN
ROCKIES EARLY FRIDAY THEN LIFTING NORTHEASTWARD DURING THE DAY AND
BRINGING ANOTHER ROUND OF ORGANIZED STORMS EITHER LATE FRIDAY
MORNING OR EARLY AFTERNOON.
IN TERMS OF THREATS...PRECIPITABLE WATER VALUES OF AROUND 1.8 INCHES
WILL SUPPORT A HEAVY RAIN THREAT TODAY AND TONIGHT WITH A
BRIEF LOWERING OF VALUES FRIDAY MORNING AS DRIER MID LEVEL AIR WORKS
IN BEHIND THE DEPARTING TROUGH. HOWEVER...ANOTHER PUSH OF HIGH PW
AIR WILL ARRIVE WITH THE NEXT EXPECTED WAVE BY FRIDAY AFTERNOON. THE
MAIN AREA OF CONCERN WILL BE THE WESTERN CWA GIVEN THAT THEY HAVE
THE BEST CHANCE OF BEING AFFECTED BY MULTIPLE ROUNDS OF CONVECTION
STARTING AS EARLY AS LATE THIS AFTERNOON. EACH OF THE WAVES SPAWNING
THE CONVECTION WILL BE PROGRESSIVE WHICH LOOKS TO LIMIT THE DURATION
OF HEAVY RAIN BUT 2 TO 3 INCHES BETWEEN NOW AND FRIDAY LOOKS
REASONABLE ON THE LARGE SCALE THOUGH ISOLATED HIGHER AMOUNTS ARE
CERTAINLY POSSIBLE. DECIDED TO GO WITH A FLASH FLOOD WATCH FOR LA
SALLE AND LIVINGSTON COUNTIES GIVEN THE 4-5+ INCHES OF RAINFALL
OBSERVED THERE OVER THE PAST FEW DAYS AND THE EXPECTED RAINFALL
ABOVE. AREAS TO THE NORTH HAVE SEEN FAR LESS RAINFALL SO POTENTIAL
IS LESS CERTAIN THERE AND 1 AND 3 HR FLASH FLOOD GUIDANCE VALUES ARE
1.6 AND 1.9 INCHES RESPECITVELY AND HIGHER. AREAS TO THE EAST ALONG
THE I-80 CORRIDOR HAVE ALSO SEEN SIGNIFICANT RAINFALL THE PAST FEW
DAYS BUT STILL HAVE QUESTIONS HOW FAR EAST THE HEAVIEST RAINFALL
WILL STRETCH AND ALSO EXPECT A BIT LATER START TO THE BEST ORGANIZED
CONVECTION THERE. AN EXPANSION IS POSSIBLE HOWEVER. IN TERMS OF THE
SEVERE THREAT...STORMS THAT CAN DEVELOP PRIOR TO MID AFTERNOON WILL
HAVE SOME SEVERE THREAT WITH DECENT INSTABILITY AND SUFFICIENT DEEP
LAYER SHEAR FOR ORGANIZATION. AGAIN...THE FORCING DURING THIS PERIOD
IS SUBTLE AT BEST AT THIS POINT AND THERE IS SOME MINIMAL
CAPPING...SO FEEL CHANCES ARE PRETTY LOW. ONCE EVENING ARRIVES...THE
ODDS ARE BETTER THAT AN ORGANIZED CONVECTIVE COMPLEX OR COMPLEXES
WILL MOVE IN. HEAVY RAIN AND DAMAGING WINDS WILL BE THE MAIN
THREATS. SOME OF THE SEVERE THREAT MAY BE CONDITIONAL BASED ON HOW
THINGS DEVELOP UPSTREAM AND IF ANY LATE MORNING/EARLY AFTERNOON
CONVECTION CAN DEVELOP. SEVERE POTENTIAL MAY BE HIGHER FRIDAY
DEPENDING ON CONVECTIVE DEBRIS...BUT LOW LEVEL WIND FIELDS
STRENGTHEN WITH GREATER DEEP LAYER SHEAR AS WELL SO BETTER STORM
ORGANIZATION IS POSSIBLE. DAMAGING WIND/HAIL/ISOLATED TORNADO
THREATS MAY BE HIGHER. WARM AND MUGGY CONDITIONS WILL CONTINUE.
HIGHS TODAY WILL BE TOUGH WITH A BREEZY SOUTH-SOUTHWEST WIND
POINTING TOWARD WARMER READINGS BUT APPROACHING CLOUD COVER ARGUING
AGAINST. WILL CONTINUE WITH MID 80S WITH SOME POTENTIAL FOR HIGHER
VALUES IF CLOUD COVER IS LESS THAN EXPECTED. FRIDAY SHOULD BE
SLIGHTLY COOLER WITH MORE CLOUDS AND HIGHER DAYTIME PRECIP CHANCES.
SATURDAY THROUGH MID WEEK...AN UPPER TROUGH WILL MOVE SOUTHEAST
ACROSS NORTHERN ALBERTA/SASKATCHEWAN FRIDAY NIGHT AND PHASE WITH THE
CLOSED UPPER LOW OVER THE DAKOTAS. THIS WILL ALLOW THE LOW TO OPEN
UP AND THEN SWING SOUTHEASTWARD. IN TURN...THE SURFACE LOW WILL BE
KICKED EASTWARD AS WELL PUSHING THE COLD FRONT INTO THE AREA
SATURDAY. THIS WILL TRIGGER ADDITIONAL CHANCES FOR
CONVECTION...ESPECIALLY ACROSS THE EASTERN HALF OF THE FORECAST AREA
SATURDAY AFTERNOON AND EVENING. THE UPPER TROUGH CROSSES THE AREA
SATURDAY EVENING THOUGH CYCLONIC UPPER FLOW WILL CONTINUE THROUGH
SUNDAY. MUCH COOLER AIR WILL FLOW IN FROM THE NORTH WITH H85 TEMPS
FALLING FROM AROUND +16 TO +4 BY SUNDAY EVENING. SHOWER/ISOLD
THUNDER CHANCES WILL LINGER SUNDAY WITH THE CYCLONIC FLOW. HIGH
PRESSURE WILL SPREAD SOUTHWARD INTO THE PLAINS WHICH WILL PROVIDE
QUIET WEATHER MONDAY. MODEL GUIDANCE DIVERGES TUESDAY WITH HOW THE
UPPER FLOW PATTERN EVOLVES THOUGH IT DOES APPEAR THAT AT LEAST WEAK
UPPER RIDGING WILL MOVE ACROSS TUESDAY BRINGING WARMER MID LEVEL AIR
BUT TROUGHING RETURNS BY MID WEEK. PRECIP CHANCES MAY RETURN AS
EARLY AS TUESDAY EVENING DEPENDING ON HOW THE FLOW PATTERN PANS OUT
BUT GIVEN THE POTENTIAL FOR WAA TO BUILD AHEAD OF THE RIDGE OR AN
ACTIVE ZONAL PATTERN IF THE RIDGE IS WEAKER...SOME PRECIP IS
POSSIBLE. TEMPS WILL BE COOLER SUNDAY WITH HIGHS IN THE MID 60S
NORTH TO AROUND 70 SOUTH WITH MONDAY AND TUESDAY EACH BEING WARMER
THAN THE DAY BEFORE. FLOW OFF THE LAKE SUNDAY THROUGH TUESDAY WILL
KEEP LAKESHORE READINGS COOLER AND LAKE BREEZE DEVELOPMENT MAY
PROPEL COOLER TEMPS FURTHER INLAND EACH AFTERNOON.
MDB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SEVERAL ROUNDS OF THUNDERSTORMS POSSIBLE.
* GUSTY SOUTHERLY WINDS.
BMD
//DISCUSSION...UPDATED 18Z...
AN ACTIVE PERIOD IS EXPECTED WITH SEVERAL BOUTS OF THUNDERSTORMS
POSSIBLE AND GUSTY SOUTHERLY WINDS.
SYNOPTICALLY...AREA OF LOW PRESSURE LIES OVER THE NORTHERN PLAIN AND
WILL GRADUALLY SHIFT NORTHEAST THROUGH THE TAF PERIOD. NORTHERN
ILLINOIS LIES IN A TIGHT SOUTHERLY GRADIENT WITH WINDS GUSTING TO
AROUND 30 KT ALREADY EARLY THIS AFTERNOON AND EXPECTED TO PERSIST
THROUGH THE DAY. WINDS MAY TAPER SOME WITH SUNSET...THEN ARE
EXPECTED TO BECOME GUSTY AGAIN FRIDAY...THOUGH NOT QUITE AS STRONG
AS TODAY.
SEVERAL ROUNDS OF THUNDERSTORMS ARE POSSIBLE...WITH THE DETAILS
STILL A BIT MURKY. FIRST ROUND IS ALREADY STARTING TO TAKE SHAPE
THIS AFTERNOON AS STRONG INSTABILITY HAS DEVELOPED OVER THE AREA
WITH CONVECTION ALREADY DEVELOPING DOWNSTATE AHEAD OF A NEGATIVELY
TILTED TROUGH LIFTING ACROSS THE MID MISSISSIPPI VALLEY. THIS WAVE
WILL CONTINUE NORTHEAST INTO NORTHERN ILLINOIS MID AFTERNOON WITH
SCATTERED STRONG TO SEVERE THUNDERSTORMS EXPECTED OVER THE AREA.
WITH NO SIGNIFICANT LOW LEVEL BOUNDARIES OR FOCUSING MECHANISMS...IT
WILL BE HARD TO IMPOSSIBLE TO PINPOINT EXACTLY WHERE THUNDERSTORMS
WILL DEVELOP...THOUGH THE BEST INSTABILITY HAS SET UP JUST WEST OF
THE CHICAGO TERMINALS. THEN THIS EVENING...NUMEROUS CONVECTIVE
ALLOWING MODELS ARE INDICATING THAT A SECOND ROUND OF CONVECTION
WILL CONGEAL INTO A LINE OFF TO OUR WEST WITH THE DEVELOPMENT OF A
MODERATE TO STRONG LOW LEVEL JET ALONG THE MISSISSIPPI RIVER VALLEY.
THIS LINE IS EXPECTED TO RACE EAST LATE THIS EVENING OR EARLY
OVERNIGHT. FINALLY...WITH SIMILAR CONDITIONS IN PLACE
TOMORROW...WILL BE LOOKING AT MUCH OF THE SAME CONCERNS FRIDAY WITH
RESPECT TO PERIODIC CONVECTIVE CHANCES.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM TO HIGH CONFIDENCE IN TSTRMS THIS AFTERNOON...LOW
CONFIDENCE IN DIRECT IMPACTS TO TERMINALS DUE TO SCATTERED
COVERAGE.
* MEDIUM CONFIDENCE IN LINE OF TSTRMS IMPACTING TERMINALS LATE
THIS EVENING.
* MEDIUM CONFIDENCE IN ADDITIONAL TSTRMS FRIDAY...LOW CONFIDENCE
IN TIMING.
* MEDIUM TO HIGH CONFIDENCE IN WIND TRENDS.
BMD
//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...ILZ019-ILZ032...7 PM THURSDAY TO 7 PM
SATURDAY.
IN...NONE.
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
1259 PM CDT THU MAY 30 2013
.DISCUSSION...
ISSUED 1030 AM CDT THU MAY 30 2013
MORNING SURFACE ANALYSIS SHOWS HIGH PRESSURE ANCHORED ALONG THE
EAST COAST AND LOW PRESSURE CENTERED OVER SOUTH DAKOTA. THE
PRESSURE GRADIENT BETWEEN THESE TWO FEATURES IS CREATING
STRONG/GUSTY SOUTHERLY WINDS ACROSS CENTRAL ILLINOIS...WITH THE
15Z/10AM OBS INDICATING GUSTS ALREADY EXCEEDING 30 MPH IN A FEW
LOCATIONS. RADAR MOSAIC HAS BEEN FAIRLY QUIET SO FAR...WITH ONLY A
FEW ISOLATED SHOWERS ACROSS EAST-CENTRAL ILLINOIS EARLIER THIS
MORNING. DESPITE RATHER BULLISH PRECIP DEVELOPMENT IN THE WARM
SECTOR AS ADVERTISED BY THE 12Z NAM...THINK ONLY ISOLATED
SHOWERS/THUNDER WILL OCCUR ACROSS THE AREA THROUGH EARLY
AFTERNOON. AS ATMOSPHERE DESTABILIZES...SCATTERED SHOWERS/STORMS
WILL DEVELOP BY MID TO LATE AFTERNOON. LATEST HRRR SUGGESTS THE
MOST WIDESPREAD CONVECTION WILL REMAIN WEST OF THE MISSISSIPPI
RIVER UNTIL THIS EVENING WHEN STORMS TRACK INTO AT LEAST THE
WESTERN HALF OF THE KILX CWA. HAVE UPDATED FORECAST TO LOWER POPS
THIS MORNING...FEATURING ONLY ISOLATED SHOWERS THROUGH EARLY
AFTERNOON. WILL GO WITH SCATTERED WORDING THIS AFTERNOON...THEN
WILL HIT POPS HARD TONIGHT WHEN BETTER FORCING APPROACHES FROM THE
WEST. ZONE UPDATE HAS ALREADY BEEN ISSUED.
&&
.AVIATION...
ISSUED 1258 PM CDT THU MAY 30 2013
SCATTERED CONVECTION WILL CONTINUE TO DEVELOP WITHIN THE WARM SECTOR
ACROSS CENTRAL ILLINOIS THIS AFTERNOON. THE STORMS WILL TRACK FROM
SOUTH TO NORTH ACROSS THE AREA...PRIMARILY IMPACTING LOCATIONS
WEST OF I-57. BASED ON LATEST RADAR DATA...HAVE INCLUDED A TEMPO
GROUP FOR THUNDER AT ALL TAF SITES EXCEPT KCMI. WILL NEED TO
MONITOR LARGER COMPLEX OF STORMS DEVELOPING FURTHER WEST OVER THE
CENTRAL PLAINS AS IT MAY WORK ITS WAY EASTWARD INTO THE AREA
TONIGHT. AT THIS TIME...WILL FOCUS ON THE IMMEDIATE CONVECTION
THIS AFTERNOON/EARLY EVENING AND KEEP OVERNIGHT FORECAST DRY
UNTIL TRENDS BECOME MORE APPARENT. WINDS WILL BE STRONG/GUSTY
THROUGH THE PERIOD. GUSTS WILL FREQUENTLY EXCEED 30KT THIS
AFTERNOON...THEN WINDS WILL DIMINISH TO BETWEEN 10 AND 15KT LATE
TONIGHT INTO FRIDAY MORNING.
BARNES
&&
.PREV DISCUSSION...
ISSUED 316 AM CDT THU MAY 30 2013
SHORT TERM...TODAY THROUGH SATURDAY
07Z SURFACE MAP SHOWED DOUBLE-BARREL LOW PRESSURE OVER THE PLAINS
WITH ONE LOW CENTER IN CENTRAL SD AND A SOUTHERN LOW NEAR THE
OK/TX PANHANDLE. TIGHTENING MSLP GRADIENT BETWEEN THIS AND SFC
HIGH ALONG THE EAST COAST CAUSED 10-20 MPH S/SE WINDS
OVERNIGHT...KEEPING DEWPOINTS UP IN THE MID 60S AND EARLY MORNING
TEMPS IN THE UPPER 60S TO LOWER 70S. NEGATIVELY TILTED MID LEVEL
TROF WAS LIFTING INTO THE WESTERN HIGH PLAINS RESPONSIBLE FOR
LARGE AREA OF CONVECTION FROM THE PLAINS INTO THE UPPER MIDWEST.
WATER VAPOR IMAGERY INDICATED A WEAK WAVE AND MID LEVEL MOISTURE
POOL TRACKING NORTH FROM THE LOWER MS VALLEY...ON THE BACK SIDE OF
THE SUB-TROPICAL RIDGE CENTERED OFF THE EAST COAST. SHORT RANGE
HI-RES MODELS DEVELOP CONVECTION WITH THIS FEATURE AS IT SHIFTS NE
INTO THE LOWER OHIO VALLEY THIS MORNING...AND LATEST RADAR MOSAIC
INDICATED A SHOWER IN EAST CENTRAL IL AND A FEW MORE IN SE MO.
THUS MAY SEE A SLIGHTLY MORE FOCUSED AREA OF SCATTERED
SHOWERS/STORMS EAST OF I-57 INTO MID MORNING. OTHERWISE DEEPER
CONVECTION IS EXPECTED TO DEVELOP OVER MISSOURI AND IOWA THIS
AFTERNOON ASSOCIATED WITH A SIGNIFICANT SHORTWAVE EJECTING OUT OF
THE WESTERN TROF. CONVECTIVE MODELS SHOW THIS ENTERING THE WESTERN
CWA LATER THIS AFTERNOON AND EVENING...IN A WEAKENING FASHION AS
LESS INSTABILITY IS INDICATED EAST OF THE MS RIVER. MOIST PROFILES
ALSO SUGGEST A LOWER SVR THREAT...HOWEVER WITH DECENT WIND FIELDS
ALOFT WOULD NOT BE SURPRISED TO SEE SOME STRONG OR NEAR SVR
STORMS. ASIDE FROM POSSIBLE CONVECTION...ANOTHER ISSUE WILL BRISK
AND GUSTY SOUTH WINDS IN TIGHT GRADIENT. BUFKIT DATA SHOWS GUSTS
OVER 30 KTS DURING PEAK HEATING BUT CLOUD COVER COULD TEMPER
HIGHER GUSTS.
FAIRLY STRONG MODEL SIGNALS THAT AN MCS WILL FORM OVER KS/MO
TONIGHT AND LIFT NORTHEAST INTO THE CWA ON FRIDAY. THIS
SHOULD BE MAINTAINED BY A VIGOROUS 40-60 KT LLJ AND COULD BRING
ANOTHER ROUND OF HEAVY RAIN TO THE NW CWA INTO MIDDAY. THE EFFECTS
OF THIS MCS WILL IMPACT CONVECTIVE DEVELOPMENT LATER IN THE DAY
AND IF ATMOSPHERE CAN RECOVER THEN STRONG STORMS MAY REDEVELOP ALONG
THE LINGERING OUTFLOW BOUNDARY. BETTER WIND FIELDS ALOFT
ASSOCIATED WITH THE APPROACHING UPPER TROF WILL CONTRIBUTE TO
HIGHER BULK SHEAR AND THE POTENTIAL FOR MORE ORGANIZED SEVERE
WEATHER.
AS THE UPPER TROF STEADILY SHIFTS EAST...IT WILL DRIVE A COLD
FRONT INTO THE STATE ON SATURDAY. FRONTAL TIMING WILL BE CRITICAL
FOR ANOTHER ROUND OF POSSIBLE SEVERE STORMS AND HEAVY RAIN...AND
00Z MODELS ARE A FEW HOURS QUICKER WITH THE FRONT THAT PREVIOUS
RUNS. THIS WOULD FAVOR BEST CHANCE OF REDEVELOPMENT ALONG THE
FRONT OR PRE-FRONTAL TROF FOR THE CENTRAL OR EASTERN CWA SATURDAY
AFTERNOON INTO EVENING.
WITH THE THREAT FOR HEAVY RAIN STARTING LATER THIS AFTERNOON
ACROSS THE WEST...AND CONTINUING UNTIL THE COLD FRONTAL PASSAGE
SATURDAY HAVE DECIDED TO GO WITH ANOTHER FLASH FLOOD WATCH
ALONG/WEST OF I-55. THIS WILL BE IN EFFECT THIS AFTERNOON THROUGH
SATURDAY AFTERNOON. SEE HYDROLOGY SECTION BELOW FOR MORE INFO ON
HEAVY RAIN/FLOOD POTENTIAL.
LONG TERM...SUNDAY THROUGH WEDNESDAY
THE POST-FRONTAL AIRMASS WILL BRING A RETURN TO MUCH COOLER AND
DRIER WEATHER FOR THE LAST HALF OF THE WEEKEND. A DEEP TROF IS
FORECAST TO ROTATE SOUTH INTO THE NORTHERN GREAT LAKES BY LATE
SUNDAY WITH A CHILLY...FOR EARLY SUMMER...-24C 500 MB AIRMASS.
CANADIAN HIGH PRESSURE AT THE SURFACE WILL BUILD INTO THE GREAT
LAKES BY EARLY NEXT WEEK...AND CONTINUE TO PROVIDE A COOL
NORTHERLY FLOW TO CENTRAL IL. THUS TEMPERATURES ARE EXPECTED TO BE
SEVERAL DEGREES BELOW NORMAL INTO TUESDAY. BY LATE TUESDAY AND
WEDNESDAY...THE NEXT UPPER LEVEL WAVE PUSHING INTO THE PLAINS WILL
DEVELOP LOW PRESSURE TO OUR WEST. WARM ADVECTION PRECIP WITH THIS
FEATURE WILL SPREAD RAIN CHANCES EAST OF THE MS RIVER FOR MID-
WEEK.
25
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH SATURDAY EVENING FOR ILZ027>031-
036>038-040>042-047>051.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
300 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/MAINTAINANCE
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 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1217 PM EDT THU MAY 30 2013
MAINLY VFR THROUGH THE PERIOD WITH PRIMARY FOCUS ON CONVECTIVE
POTENTIAL THIS AFTERNOON AND EARLY EVENING. MODERATE INSTABILITY
THIS AFTERNOON COINCIDENT WITH CONTINUED LOW/MID LEVEL THETA-E
ADVECTION AND A SHORTWAVE LIFTING NORTHEAST INTO ILLINOIS SHOULD
ALLOW FOR A FEW SHOWERS/STORMS TO DEVELOP AROUND 19-20Z. KEPT THE
2 HOUR TEMPO TSRA/MVFR GROUP AT SBN WHERE BETTER CHANCES FOR
CONVECTION RESIDES. LESSER CHANCES AT FWA WHERE VCTS/VFR GROUP
ADDED BTW 20-01Z. SHOWER/STORM ACTIVITY SHOULD DIMINISH BTW 23-02Z
GIVEN LOSS OF HEATING AND WEAK FORCING...LEAVING MOST OF THE
EVENING DRY/VFR. CONFIDENCE BEYOND MIDNIGHT IS LOW AS A WEAKENING
UPSTREAM CONVECTIVE COMPLEX ACROSS MISSOURI/IOWA MAKES A RUN AT
THE GREAT LAKES. ADDED A VCSH MENTION AFTER 07Z AT SBN AS
WEAKENING LINE OF SHOWERS/STORMS MAY HOLD TOGETHER INTO NORTHWEST
INDIANA. RETAINED OPTIMISTIC DRY FCST AT FWA.
&&
.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...STEINWEDEL
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AREA FORECAST DISCUSSION
NWS DES MOINES IA
350 PM CDT THU MAY 30 2013
.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...30/18Z
ISSUED AT 103 PM CDT THU MAY 30 2013
AREA OF SHOWERS AND MVFR CIGS ACROSS THE AREA...SHOULD CONTINUE TO
SLIGHTLY MOVE NORTH AND EAST THROUGH THE AFTERNOON. CHANCES FOR
THUNDERSTORMS TO INCREASE ESPECIALLY AT THE EASTERN TAF SITES THIS
AFTERNOON INTO EARLY EVENING. MAJORITY OF PRECIPITATION CHANCES
EXPECTED TO END ACROSS THE CWA BY MID EVENING...WITH POSSIBLY HIGH
MVFR TO LOW VFR CIGS EXPECTED OVERNIGHT. POSSIBILITY OF FOG
REDUCING VSBYS/CIGS LATE TONIGHT DUE TO ABUNDANT MOISTURE
AROUND...HOWEVER VERY UNCERTAIN SO HAVE NOT PLACED IN THE TAF AT
THIS TIME. GUSTY SOUTHERLY WINDS EXPECTED THROUGH THE PERIOD.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR SOUTHEAST BUTLER.
&&
$$
SHORT TERM...BEERENDS
LONG TERM...LEE
AVIATION...BEERENDS
AREA FORECAST DISCUSSION
NWS TOPEKA KS
344 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 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1239 PM CDT THU MAY 30 2013
CHALLENGING FORECAST. LINE OF SHOWERS SHOULD HAVE MOVED THROUGH
TOP AND FOE BY A LITTLE AFTER 18Z TODAY. THEN ANOTHER CHANCE OF
SHOWERS AND STORMS LATE AFTERNOON EARLY EVENING...AND ANOTHER
CHANCE LATE TONIGHT AND FRIDAY MORNING. OTHER THAN IN
SHOWERS...WINDS SHOULD BE FROM THE SOUTH. POTENTIAL MVFR
CONDITIONS IN SOME OF THE HEAVIER SHOWERS AND STORMS.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...60
LONG TERM...65
AVIATION...PHILLIPS
AREA FORECAST DISCUSSION
NWS JACKSON KY
128 PM EDT THU MAY 30 2013
.UPDATE...
ISSUED AT 127 PM EDT THU MAY 30 2013
WILL UPDATE NDFD HOURLY DATA AND WEB SERVERS BY 135 PM FOR LATEST
OBSERVATIONAL TRENDS.
UPDATE ISSUED AT 1037 AM EDT THU MAY 30 2013
NDFD AND WEB SERVERS HAVE BEEN UPDATED FOR LATEST SATELLITE AND
SURFACE OBSERVATIONAL TRENDS. ZFP UPDATE NOT NEEDED AT THIS TIME. THE
12Z HRRR POINTS TOWARDS ISOLATED SHOWERS BEING POSSIBLE OVER THE FAR
WESTERN PART OF THE FORECAST AREA FOR A FEW HOURS THIS
AFTERNOON...SIMILAR TO YESTERDAY. EXPECT PROBABILITY TO REMAIN
BELOW 15 PERCENT AND WILL NOT ADD THIS TO FORECAST. THE 12Z NAM
SUPPORTS A DRY FORECAST THIS AFTERNOON....WITH LOW PROBABILITY OF
SHOWERS IN THE WESTERN PART OF THE AREA TONIGHT. THIS IS IN THE CURRENT
FORECAST FOR TONIGHT AND WILL LEAVE AS IS FOR NOW.
UPDATE ISSUED AT 750 AM EDT THU MAY 30 2013
UPDATED THE FORECAST MAINLY TO KEEP THE NEAR TERM GRIDS ON TRACK WITH
THE CURRENT OBS AND TRENDS...INCLUDING SKY COVER. UPDATES HAVE BEEN
SENT TO THE NDFD AND WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 335 AM EDT THU MAY 30 2013
06Z SFC ANALYSIS SHOWS HIGH PRESSURE TO THE EAST OF KENTUCKY AND DEEP
LOW PRESSURE WELL TO THE NORTHWEST. A SOUTHERN FLOW OF WARMTH AND
MOISTURE CONTINUES THROUGH THE STATE BETWEEN THESE TWO KEY FEATURES.
ON SATELLITE...SOME HIGH CLOUDS AND A SMALLER BATCH OF LOWER ONES ARE
CROSSING EAST KENTUCKY EARLY THIS MORNING. THESE CLOUDS HAVE ONLY
HAD A SMALL IMPACT ON THE RADIATIONAL COOLING THROUGH THE CWA THIS
NIGHT WITH RIDGES STAYING UP IN THE UPPER 60S AND LOWER 70S WHILE THE
MOST SHELTERED VALLEYS CONTINUE THEIR PLUNGE INTO THE UPPER AND
MIDDLE 50S. ALSO SIMILAR TO LAST NIGHT...DEEPER LOCATIONS IN THE
WESTERN PORTIONS OF THE CUMBERLAND VALLEY...WEST OF I-75...ARE
STAYING A BIT MILDER WHEN COMPARED TO VALLEYS FURTHER EAST. AT THE
SAME TIME...DEWPOINTS ARE IN THE LOWER 60S THROUGHOUT THE AREA. WITH
THE VALLEY TEMPS FALLING TO NEAR THEIR DEWPOINTS...DO EXPECT SOME
LIGHT FOG TO DEVELOP IN THE PREDAWN HOURS...BUT STILL BE MAINLY
CONFINED TO THE LOCATIONS ALONG RIVERS AND OTHER BODIES OF WATER.
THE MODELS ARE IN PRETTY GOOD AGREEMENT WITH THE UPPER LEVEL PATTERN
AFFECTING THE REGION THROUGH THE SHORT TERM. THEY ALL SHOW THE
SOUTHEAST RIDGE STRONGLY INFLUENCING EAST KENTUCKY FOR AT LEAST ONE
MORE DAY WHILE A LARGE AREA OF TROUGHING CONSOLIDATES OVER THE HIGH
PLAINS. HEIGHTS WILL START TO FALL LOCALLY LATER TONIGHT AS THE BROAD
TROUGH TO THE NORTHWEST PRESSES IN ON THE WESTERN FRINGES OF THE OHIO
VALLEY. THIS PROCESS WILL BE ACCOMPANIED BY A LEADING BAND OF
SHORTWAVE ENERGY CROSSING INTO THE REGION BY DAWN FRIDAY...JUST NORTH
OF THE OHIO RIVER. THIS BAND WEAKENS DURING THE DAY FRIDAY AS IT
ADVANCES EAST INTO THE RETREATING RIDGE. THE NAM12 AND GFS HAVE
SIMILAR IDEAS WITH THIS FIRST BATCH OF ENERGY AND ITS EFFECT ON
WEATHER SO HAVE GONE WITH A BLEND OF THESE TWO MODELS FOR WX
SPECIFICS THROUGH FRIDAY.
SENSIBLE WEATHER WILL SEE THE WARM AND INCREASINGLY MUGGY AIR MASS
SET THE STAGE FOR MORE IN THE WAY OF CONVECTION TO CLOSE OUT THE WORK
WEEK. HIGHER PW AIR CONTINUES TO BUILD OVER EAST KENTUCKY TODAY AND
FRIDAY. STILL CANNOT RULE OUT SOME STRAY POP UP STORMS LATE THIS
AFTERNOON...MAINLY JUST TO OUR WEST...BUT WITH CHANCES STILL TOO LOW
TO MENTION IN THE ZONES OR REPRESENT IN THE WX GRIDS AT THIS TIME.
THIS IS DESPITE LOW LIS AND MODERATELY HIGH CAPE...AS A TRIGGER WILL
BE HARD TO COME BY UNTIL LATER. A BETTER CHANCE FOR CONVECTION WILL
OCCUR LATER TONIGHT...AGAIN PRIMARILY OVER OUR WESTERN ZONES...AS
THE APPROACHING MID LEVEL WAVE WILL HELP YO ACTIVATE THIS
INCREASINGLY SOUPY AIR MASS. THIS DEVELOPMENT WILL KEEP A DECENT
THREAT OF SHOWERS AND THUNDERSTORMS IN THE FORECAST THROUGHOUT THE
DAY FRIDAY...WORKING WEST TO EAST WITH TIME. THE EXPECTED INCREASE IN
CLOUD COVER AND CONVECTION WILL ALSO LIKELY SERVE TO CAP TEMPERATURES
IN THE MID 80S ON FRIDAY...A TAD LOWER THAN TODAY. BEFORE THE MORE
ORGANIZED AREA OF CONVECTION GETS GOING LATE TONIGHT...DO EXPECT
ANOTHER SMALL TO MODERATE RIDGE AND VALLEY TEMPERATURE SPLIT TO
DEVELOP BY LATE EVENING THOUGH MUCH OF THIS WILL BE WASHED OUT BY THE
LOWER CLOUDS AND SCATTERED COVERAGE OF SHOWERS AND THUNDERSTORMS
TOWARD DAWN FRIDAY.
HAVE USED THE CONSSHORT FOR TD AND WINDS THROUGH THE FIRST 24 HOURS
AS A STARTING POINT...PERSISTENCE FOR HIGHS TODAY AND A MODIFIED
VERSION OF THIS NIGHT/S LOWS FOR TONIGHT. FOR FRIDAY...FAVORED THE
CONSALL FOR HIGHS. DID USE A DIURNAL FROM OBS SCHEME FOR HOURLY T
GRIDS WITH SOME ADJUSTMENTS LATE TONIGHT TO ACCOUNT FOR THE INCREASE
IN CLOUDS AND SCATTERED CONVECTION. AS FOR POPS...KEPT THEM IN LINE
WITH LOW MOS GUIDANCE TODAY BEFORE ENDING UP CLOSER TO THE HIGHER MET
NUMBERS TONIGHT AND THE LOWER MAV ONES ON FRIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 300 AM EDT THU MAY 30 2013
GENERAL AGREEMENT AMONGST THE FORECAST MODELS ONCE AGAIN FOR THE
EXTENDED PERIOD OF THE FORECAST. THE GFS AND ECMWF SOLUTIONS WERE
PREFERRED FOR THIS RENDITION OF THE EXTENDED DUE TO THEIR
SIMILARITIES. THE TIMING OF THE PASSAGE OF A COLD FRONT SATURDAY
NIGHT INTO SUNDAY WAS CAPTURED WELL BY BOTH PREFERRED MODELS. THE
MODELS BOTH HAVE DEVELOPED A SLUGGISH FRONTAL PROGRESSION WHERE THE
FRONT GETS HUNG UP A BIT NORTH OF THE OHIO SATURDAY EVENING. IT
APPEARS THAT THE RIDGE THAT WILL DOMINATE THE WEATHER TODAY AND
TOMORROW WILL BE VERY SLOW TO WEAKEN AND MOVE OFF TO THE EAST. WITH
THIS IN MIND...DECIDED TO MODIFY THE FORECAST TOWARD THE SLOWER
FRONTAL PROGRESSION SEEN IN BOTH THE GFS AND ECMWF. ISOLATED SHOWERS
AND STORMS WILL BE POSSIBLE...AS A WEAK IMPULSE PUSHES ACROSS THE
OHIO VALLEY FRIDAY EVENING. ONCE THIS BIT OF ENERGY EXITS THE AREA
FRIDAY NIGHT...THERE SHOULD ANOTHER LULL IN THE PRECIPITATION...AS
HIGH PRESSURE BECOMES REESTABLISHED ACROSS THE AREA DURING THE DAY
ON SATURDAY. ONCE THE RIDGE FINALLY BREAKS DOWN AND MOVES OFF TO THE
EAST...A COLD FRONT WILL PUSH ACROSS THE OHIO AND TENNESSEE VALLEYS
SATURDAY NIGHT THROUGH SUNDAY NIGHT. WIDESPREAD SHOWERS AND STORMS
ARE LIKELY TO ERUPT ALONG AND JUST IN ADVANCE OF THIS BOUNDARY...AS
MOIST AIR FROM THE GULF OF MEXICO POURS INTO THE AREA ON
SOUTHWESTERLY AND SOUTHERLY WINDS. THE LATEST FORECAST SOUNDINGS
WERE SHOWING MUCH BETTER INSTABILITY AND WIND SHEAR DURING THE DAY
ON SUNDAY...PARTICULARLY DURING THE AFTERNOON AND EVENING HOURS.
WITH CONDITIONS A BIT MORE JUICY AND ENERGETIC...THE POSSIBILITY FOR
A FEW STRONG STORMS WILL EXIST ON SUNDAY...WITH STRONG WINDS AND
HAIL POSSIBLE. THE SOUNDINGS ALSO ARE SHOWING THE POTENTIAL FOR
LOCALLY HEAVY RAINFALL...SO THIS WILL PRESENT THE POSSIBILITY OF
LOCALIZED HYDROLOGY ISSUES WITH THE STRONGER STORMS OR WHERE SHOWERS
AND STORM MOVE REPEATEDLY ACROSS THE SAME AREAS. WITH THE MODELS
BEING IN GOOD AGREEMENT...AND THE MODELS SHOWING FAVORABLE
CONDITIONS FOR SHOWERS AND STORMS TO FORM...WENT VERY CLOSE TO THE
MEXMOS POPS FOR SATURDAY NIGHT AND SUNDAY.
THE PERIOD WILL BEGIN WITH WELL ABOVE NORMAL TEMPERATURES...AS
SOUTHERLY FLOW AHEAD OF THE APPROACHING FRONT BRINGS WARM MOIST AIR
INTO THE AREA IN LARGE QUANTITIES. AFTER THE FRONT PASSES THROUGH
THE AREA LATE SUNDAY NIGHT...A MUCH COOLER AIR MASS WILL FILTER INTO
THE AREA...PAVING THE WAY FOR NORMAL TEMPERATURES MONDAY AND
TUESDAY. HIGHS EACH DAY WILL TOP OUT IN THE MID 70S. TEMPERATURES ON
SUNDAY WILL ALSO BE AROUND NORMAL DUE TO THE INFLUENCE OF
PRECIPITATION AND CLOUD COVER. ANOTHER RIDGE OF HIGH PRESSURE WILL
THEN SETTLE OVER THE REGION ON TUESDAY WEDNESDAY...BRINGING COOLER
AND DRIER WEATHER TO EASTERN KENTUCKY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 127 PM EDT THU MAY 30 2013
HIGH PRESSURE ALONG THE EAST COAST WILL SLIDE SLOWLY EAST WHILE A
CENTER OF LOW PRESSURE MOVES SLOWLY EAST THROUGH THE NORTHERN
PLAINS. A TROUGH OF LOW PRESSURE EXTENDING FROM THE NORTHERN PLAINS
LOW WILL SWING THROUGH THE MID MS VALLEY AND INTO THE GREAT LAKES
BY FRIDAY. THIS LOW PRESSURE TROUGH WILL BRING AN INCREASE IN CLOUD
COVER LATE TONIGHT AND INTO FRIDAY...BUT CEILINGS ACROSS THE REGION
WILL REMAIN VFR. IT APPEARS THAT THE SHOWERS AND THUNDERSTORMS
ASSOCIATED WITH THE LOW PRESSURE TROUGH WILL BE DECAYING AS THEY MOVE
EAST INTO EASTERN KY FRIDAY MORNING AND FOR NOW WILL LEAVE OUT OF THE
TAFS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SBH
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...SBH
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1249 PM CDT THU MAY 30 2013
.UPDATE...
FOR 18Z AVIATION DISCUSSION BELOW.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 353 AM CDT THU MAY 30 2013
A VERY ACTIVE SHORT TERM IS IN STORE AS A POTENT UPPER WAVE WORKS
ACROSS THE NATIONS MIDSECTION. H5 RAP ANALYSIS SHOWS A CLOSED LOW
HAS DEVELOPED NEAR THE BLACK HILLS THIS MORNING...WITH A NEGATIVELY
TITLED TROUGH EXTENDING FROM THERE DOWN TO NORTHEAST TEXAS. THE
RADAR MOSAIC WEDNESDAY WAS CRAMMED FULL OF CONVECTION FROM HERE ALL
THE WAY DOWN TO TEXAS...WHICH MEANS WITHIN THIS LARGE SCALE TROUGH
THERE ARE NUMEROUS LEFT OVER WAVES/MCVS. ONE SUCH WAVE IS OVER SW IA
THAT WILL SWING THROUGH HERE IN THE LATE MORNING. THE MAIN SYNOPTIC
UPPER WAVE WILL BEGIN WORKING ACROSS MN THIS AFTERNOON AND EVENING.
TO GO ALONG WITH ALL OF THE WAVES...A 50 KT LLJ IS CURRENTLY BLOWING
ACROSS MN. THIS LLJ WILL SLOWLY DIMINISH THROUGH THE MORNING...BUT A
MUCH STRONGER PUSH CURRENTLY OVER OK/KS WILL COME UP INTO SE MN/WRN
WI THIS AFTERNOON/EVENING WITH THE PRIMARY SYNOPTIC WAVE.
AT THE SFC...A 995 MB SFC LOW CAN BE FOUND NEAR PIERRE SOUTH
DAKOTA...WITH A WARM FRONT SITTING ACROSS CENTRAL MN. DURING THE
SHORT TERM...THIS LOW WILL BECOME OCCLUDED AND SLOWLY MEANDER NORTH
INTO NODAK. THE WARM FRONT WILL CONTINUE TO MOVE NORTH
TODAY...EVENTUALLY SETTLING ALONG THE INTERNATIONAL BORDER. BACK TO
THE WEST...A COLD FRONT MOVING ACROSS SODAK TODAY WILL BE ENTERING
WRN MN BY THE END OF THE PERIOD.
FOR TODAY...EXPECT A BRIEF LULL IN ACTIVITY THIS MORNING AS WE WAIT
FOR THE WAVE OVER SW IA TO GET HERE AROUND 15Z. FORECAST SOUNDINGS
ACROSS THE ENTIRE CWA SHOW VERY LITTLE IF ANY CAPPING...SO EXPECT
SHOWERS AND STORMS TO DEVELOP QUICKLY THIS MORNING ONCE A LITTLE
DAYTIME HEATING KICKS IN. SINCE WE WILL NOT BE ABLE TO BUILD MUCH
INSTABILITY THANKS TO DENSE CLOUD COVER AND THE FACT THAT ONCE A
LITTLE DEVELOPS THE ATMO WILL QUICKLY CONSUME IT...THE SEVERE THREAT
LOOKS FAIRLY LOW TODAY. FOR SEVERE WEATHER...WILL HAVE TO WATCH THAT
SECOND LLJ WORKING UP IN THE AFTERNOON. BY 00Z THE RAP HAS 50 KT
WINDS AT H85 UP INTO OUR WI CWA. LIKE YESTERDAY...THIS COULD LEAD TO
THE THREAT FOR BOWING LINE SEGMENTS AND DAMAGING WINDS.
AS FOR ANY HYDROLOGY ISSUES TODAY...THE ONLY AREA THAT WILL
PROBABLY HAVE TO BE WATCHED IS THE EAU CLAIRE AREA. THEY SET A DAILY
RAINFALL RECORD YESTERDAY AND WILL BE UNDER THE GUN FOR THE SECOND
LLJ SURGE THIS AFTERNOON...WITH THE POTENTIAL FOR SOME TRAINING OF
STORMS THIS AFTERNOON AND EVENING.
TONIGHT...THE COLD FRONT WILL START ENTERING WRN MN WHILE THE LLJ
WORKS INTO CENTRAL/ERN WI. THIS SHOULD MOVE THE HEAVY RAIN THREAT
EAST OF THE MPX CWA TONIGHT. HOWEVER...HI-RES CAMS SHOW SCT RETURNS
CONTINUING THROUGH THE NIGHT AHEAD OF THE FRONT...SO HAVE POPS
SLOWLY RAMPING DOWN FROM LIKELIES TO START THE EVENING...DOWN TO 50%
POPS OR LESS BY 12Z FRIDAY.
FOR TEMPERATURES...GIVEN ALL OF THE CLOUD COVER...IT WILL NOT BE AN
OVERLY WARM WARM SECTOR TODAY...WITH HIGHS LIKELY STAYING IN THE MID
TO UPPER 70S...DESPITE H85 TEMPS BEING UP AROUND +15C. FOR
TONIGHT...MIXED LAYER DEWPS ON THE NAM DROP INTO THE 40S BEHIND THE
FRONT...SO LOWS IN THE WRN CWA COULD END UP BEING A FEW DEGREES
COOLER THAN WHAT IS CURRENTLY INDICATED.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 353 AM CDT THU MAY 30 2013
MODELS INDICATE RATHER STRONG TROUGH AXIS WORKING THROUGH THE
AREA BY FRIDAY MORNING. THIS SHOULD WORK MUCH OF THE RAIN AND
THUNDER TO THE NORTH AND EAST OF THE AREA LATE THURSDAY NIGHT.
THIS SHOULD WORK A DRY SLOT NORTHEAST INTO SOUTHWEST PORTION OF
THE CWA DURING FRIDAY MORNING. THE UPPER CIRCULATION THEN MOVES A
FRONTAL BOUNDARY EAST ACROSS EASTERN HALF OF THE CWA FRIDAY
AFTERNOON. THE DETERMINISTIC MODELS ARE INDICATING MODEST
DESTABILIZATION ACROSS THE EASTERN HALF OF THE AREA...WITH ML
MUCAPE INCREASING TO 1500/2000 J/KG. SHEAR INCREASES INTO THE
AFTERNOON...ESPECIALLY INTO WESTERN WISCONSIN. THE ONLY INHIBITING
FACTOR FOR CONVECTIVE INITIATION ALONG THE FRONT APPEARS TO BE
RATHER WEAK SURFACE CONVERGENCE..WITH WINDS S-SW ALONG THE
BOUNDARY. THE HIRES MODELS ARE SHOWING RATHER ROBUST CONVECTION
DEVELOPING ALONG THE BOUNDARY AS IT MOVES INTO EASTERN MINNESOTA
FRIDAY AFTERNOON. WILL HAVE TO MONITOR THIS SITUATION INTO
FRIDAY...AS SEVERE WEATHER THREAT IS FORECAST TO BE LOW AT THIS
TIME.
FRONT EXITS TO THE EAST FRIDAY NIGHT TAKING THE HEAVY CONVECTIVE
POTENTIAL WITH IT. THIS WILL LEAVE THE UPPER LOW OVER THE AREA
THROUGH AT LEAST SATURDAY. SHOWERS LOOK TO BE A FAIR BET
ESPECIALLY LATER IN THE DAY AS THE LOW MOVES EAST. WITH ABUNDANT
CLOUD COVER...WILL BE LITTLE IN THE WAY OF HEATING...SO CONVECTIVE
POTENTIAL IS LOW. CLEARING SHOULD MOVE INTO THE AREA LATER
SATURDAY NIGHT...AND SUNDAY LOOKS LIKE THE BEST DAY OF THE
WEEKEND...WITH SUNSHINE AND MILD TEMPERATURES.
THE EXTENDED PORTION OF THE FORECAST STARTS OFF RATHER
COOL...ESPECIALLY OVER THE EASTERN CWA MONDAY MORNING. THERE MAY
EVEN BE A FROST POTENTIAL OVER A PORTION OF WEST CENTRAL
WISCONSIN. THE NEXT WEATHER SYSTEM MOVES INTO THE AREA LATER
MONDAY WITH SOME SHOWERS INTO THE WESTERN CWA. THE 00Z GFS AND
ECMWF DIVERGE SOMEWHAT ON THE OVERALL EVOLUTION AND MOVEMENT OF
THE NEXT LOW PRESSURE SYSTEM THAT MOVES ACROSS THE NORTHERN STATES
THROUGH MUCH OF NEXT WEEK. IT DOES APPEAR THE THREAT OF MORE
SHOWERS AND THUNDERSTORMS RETURNS BY MIDWEEK...WITH TEMPERATURES
REMAINING BELOW NORMAL THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1248 PM CDT THU MAY 30 2013
SCATTERED SHOWERS AND THUNDERSTORMS...POSSIBLY STRONG...WILL
PLAGUE THE WI TAF SITES THIS AFTERNOON AND EARLY EVENING...WITH
WIDELY SCATTERED NON-SEVERE ACTIVITY TO THE WEST OVER MN. CIGS
WILL REMAIN BETWEEN 2500-3500 FT THROUGHOUT...WITH THE POTENTIAL
FOR IFR VSBYS ATTENDANT WITH ANY SHOWERS/TS THAT AFFECT SITES.
WINDS WILL GUST TO BETWEEN 25 AND 30 KTS THIS AFTERNOON...AND
AGAIN ON FRIDAY. SHOWERS AND ISOLATED THUNDERSTORMS WILL BE
POSSIBLE AGAIN ON FRIDAY...BUT TIMING/COVERAGE CONFIDENCE IS TOO
LOW TO INCLUDE IN THE TAF AT THIS POINT.
KMSP...
SCT-BKN CLOUDS BETWEEN 2500-3500 FT WILL PREVAIL THROUGH THIS
EVENING. THE MAIN WINDOW FOR SHOWERS AND POSSIBLY ISOLATED THUNDER
WILL BE BETWEEN 23Z AND 04Z...THEN A BREAK IS EXPECTED BEFORE
DIURNALLY DRIVEN ACTIVITY POSSIBLY DEVELOPS AGAIN ON FRIDAY.
SOUTHERLY WINDS WILL GUST INTO THE UPPER 20S /KNOTS/ THIS
AFTERNOON...THEN BECOME GUSTY AGAIN BY 15Z FRIDAY.
/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...MPG
LONG TERM...DWE
AVIATION...LS
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
244 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 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...UPDATED
NWS ST LOUIS MO
136 PM CDT THU MAY 30 2013
.UPDATE...
ISSUED AT 136 PM CDT THU MAY 30 2013
TORNADO WATCH IS IN EFFECT FOR THE ENTIRE AREA UNTIL 8 PM. MUCAPES
ARE AROUND 2000 J/KG AND WILL CONTINUE TO RISE OUTSIDE OF OUTFLOW
COOLED AIR THIS AFTERNOON. EFFECTIVE SHEAR HAS IS NOW AROUND 35KTS
WHICH SUGGESTS THAT A FEW SUPERCELLS MAY DEVELOP THIS AFTERNOON...
BUT STILL EXPECT MAINLY MULTI-CELLS CAPABLE OF PRODUCING LARGE
HAIL AND DAMAGING WINDS. LOW LEVEL SHEAR IS STILL IMPRESSIVE WITH
0-1KM SHEAR BETWEEN 20-35KTS...SO A FEW BRIEF TORNADOES ARE
POSSIBLE WITHIN LINES AND IN ANY SUPERCELLS. CONTINUE TO EXPECT
STORMS TO DEVELOP ALONG THE LINE NEAR THE MISSISSIPPI RIVER. MAIN
LINE OVER WESTERN MISSOURI WILL MOVE INTO CENTRAL MO BY MID
AFTERNOON...AND NEAR THE MISSISSIPPI RIVER LATER THIS
AFTERNOON/EARLY EVENING.
BRITT
&&
.SHORT TERM...(THROUGH LATE TONIGHT)
ISSUED AT 1044 AM CDT THU MAY 30 2013
COMPLICATED FORECAST FOR THE REST OF THE DAY AS AREA OF SHOWERS/
THUNDERSTORMS ARE MOVING VERY SLOWLY EASTWARD LATE THIS MORNING.
THIS IS AHEAD OF THE NEGATIVELY TILTED TROUGH CURRENTLY OVER THE
CENTRAL PLAINS THAT THE RAP LIFTS INTO MO/IL THIS EVENING. LAST
FEW RUNS OF THE HRRR SUPPORTS THAT THE WESTERN MO COMPLEX WILL
MOVE NORTHEASTWARD INTO THE CWA BY LATE THIS AFTERNOON/EARLY THIS
EVENING. IN ADDITION...SCATTERED THUNDERSTORMS HAVE RECENTLY
DEVELOPED OVER SOUTH CENTRAL MO THAT ARE LIFTING NORTHEASTWARD.
THESE TRENDS SUPPORT GOING FORECAST THAT PRECIPITATION CHANCES
WILL INCREASE THROUGH THE AFTERNOON. MLCAPES ARE CURRENTLY
1000-1500 J/K AND SHOULD INCREASE IN THE WARM SECTOR AS
TEMPERATURES CLIMB INTO THE LOWER-MID 80S. 0-6KM SHEAR WILL BE
RELATIVELY WEAK WHICH FAVORS MULTICELL STORMS...THOUGH INCREASING
INSTABILITY AND LARGE SCALE LIFT SUGGEST THAT THERE MAY BE A FEW
SEVERE STORMS CAPABLE OF PRODUCING SOME LARGE HAIL AND DAMAGING
WIND GUSTS THROUGH THIS EVENING. THE LOW LEVEL JET WILL REMAIN
40-50KTS TODAY...SO CANNOT RULE OUT A TORNADO OR TWO IN THE STRONGEST
STORMS. LATEST RADAR IMAGERY HAS SHOWN THE TENDENCY FOR CELLS TO
TRAIN...SO HEAVY RAINFALL DOES LOOK LIKE A REAL THREAT GIVEN PWATS
AROUND 1.8 INCHES.
BRITT
.LONG TERM...(TONIGHT THROUGH WEDNESDAY)
ISSUED AT 343 AM CDT THU MAY 30 2013
(TONIGHT THROUGH SATURDAY NIGHT)
PCPN CHANCES INCREASE TONIGHT AS NEXT IN SERIES OF MCS/S DEVELOPS OVER
WESTERN MO AND SLIDES EAST THROUGH FORECAST AREA...WITH BEST
CHANCES OF HEAVY RAIN ALONG AND NORTH OF I-70. SINCE THIS AREA HAS
HAD QUITE A BIT OF RAIN OVER THE PAST WEEK AND SOILS REMAIN
SATURATED...HAVE ISSUED A FLASH FLOOD WATCH FROM 18Z TODAY THROUGH
12Z SATURDAY. LOWS TONIGHT TO REMAIN MILD...IN THE MID 60S TO LOW
70S.
FOR FRIDAY...A LOT WILL DEPEND ON HOW SOON THIS AREA OF STORMS
WEAKENS/EXITS FORECAST AREA...ON WHAT WILL DEVELOP FOR THE AFTERNOON
AND EVENING HOURS. IF ATMOSPHERE GETS WORKED OVER...IT WILL TAKE A
LOT FOR IT TO RECOVER. FOR NOW...WILL ERR ON THE SIDE OF CAUTION
WITH STORMS REDEVELOPING BY THE AFTERNOON HOURS AS NEXT SHORTWAVE
SLIDES THROUGH. WITH DECENT INSTABILITY...MID LEVEL LAPSE RATES AND
STRENGTHENING LOW LEVEL JET...WILL SEE A CHANCE FOR SEVERE WEATHER
ONCE AGAIN FRIDAY AFTERNOON AND OVERNIGHT. ANOTHER ROUND OF HEAVY RAIN
IS POSSIBLE AS WELL...WHICH WILL EVENTUALLY SHIFT TO THE SOUTH WITH
TIME. SO MAY NEED TO EXTEND FLASH FLOOD WATCH TO INCLUDE REST OF
FORECAST AREA.
MAIN COLD FRONT TO FINALLY MOVE THROUGH THE AREA DURING THE DAY ON
SATURDAY WITH LAST IN A SERIES OF SHORTWAVES SLIDING THROUGH...SO
PCPN TO TAPER OFF BY SATURDAY EVENING.
(SUNDAY THROUGH NEXT WEDNESDAY)
COOLER AND DRIER WEATHER IS IN STORE FOR THE LAST PART OF THE
WEEKEND AND INTO EARLY NEXT WEEK. HIGHS WILL BE IN THE UPPER 60S TO
MID 70S SUNDAY THROUGH TUESDAY. THEN NEXT WEATHER SYSTEM TO APPROACH
THE REGION BY MID WEEK WITH NEXT CHANCE FOR SHOWERS AND
THUNDERSTORMS BEGINNING TUESDAY NIGHT.
BYRD
&&
.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
&&
.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...UPDATED
NWS ALBUQUERQUE NM
1200 PM MDT THU MAY 30 2013
.AVIATION...
18Z TAF CYCLE
WITH A POTENT UPPER LEVEL JET STRETCHED OVER NORTHERN NEW
MEXICO...ANOTHER AFTERNOON OF GUSTY WEST TO NORTHWEST WINDS WILL
PREVAIL ACROSS THE FORECAST AREA...FAVORING THE NORTHERN HIGH
TERRAIN...ADJACENT EAST SLOPES...EASTERN HIGHLANDS AND NORTHEAST
PLAINS. SATELLITE WV IMAGERY DEPICTS MOUNTAIN WAVES IN THE
NORTHEAST THIRD OF THE FORECAST AREA. SURFACE WINDS WILL GUST TO
35-40KTS ACROSS THE NORTH AND KABQ WILL BE MONITORED FOR A POTENTIAL
AWW ISSUANCE...TAF IS CURRENTLY CARRYING GUSTS JUST BELOW
CRITERIA. BLOWING DUST COULD RESTRICT VISIBILITIES TO 3-5SM CENTRAL
AND EASTERN LOCATIONS. WINDS WILL GRADUALLY RELAX AFTER 03Z...AND
WILL START TO INCREASE AFTER 15Z ON FRIDAY WITH SOMEWHAT LOWER
MAGNITUDES THAN THOSE OF TODAY. WITH THE EXCEPTION OF AREAS IMPACTED
BY BLOWING DUST...VFR CONDITIONS EXPECTED ALL AREAS.
05
&&
.PREV DISCUSSION...325 AM MDT THU MAY 30 2013...
DRYLINE HAS SO FAR STAYED TO THE EAST OF NEW MEXICO THIS MORNING AND
ALTHOUGH IT/S FAIRLY CLOSE TO HOBBS DON/T EXPECT IT TO GET MUCH
FARTHER WEST IF AT ALL. IN THE NORTHEAST DEWPOINTS HAVE COME UP AS
THE SFC LOW SHIFTED INTO THE TX/OK PANHANDLES BUT THIS INCREASE
LIKELY WON/T LAST LONG WITH THE RUC FORECASTING A WEAK SFC LOW TO
REDEVELOP OVER SE CO BY MIDDAY. MODELS ALSO SHOW CURRENT BATCH OF
MID LEVEL MOISTURE EXITING BY MIDDAY. UPPER JET TO RETREAT NWD TODAY
BUT WILL BE STRETCHED OVER FAR NRN NM AND COLORADO...COMBINED WITH
THE SFC LOW PLACEMENT WILL HAVE LOW END WIND ADVY OVER SOME OF THE
NORTH CENTRAL/NORTHEAST SOUTH TO CLINES CORNERS.
DRY INTO FRIDAY NIGHT. ANOTHER WINDY DAY ON FRIDAY WITH CRITICAL
FIRE WX CONDITIONS POSSIBLE. ANOTHER BATCH OF MID LEVEL MOISTURE
PASSES OVERHEAD TONIGHT AND FRIDAY BUT ANYTHING MORE THAN A FEW
SPRINKLES OUT OF IT...IF THAT...WOULD BE A SURPRISE.
SURFACE FRONT PUSHES THROUGH FRIDAY NIGHT WITH THE BACK DOOR FRONT
INTO THE EAST SATURDAY. LOW LEVEL MOISTURE APPEARS TO MOVE IN FROM
THE SOUTH AND SOUTHEAST WITH INCREASING INSTAB SO WENT AHEAD AND
SPREAD SOME SMALL POPS FROM THE EAST SLOPES OF THE SOUTH CENTRAL
MOUNTAIN ACROSS CHAVES COUNTY AND NORTHEAST ALONG THE TX BORDER
SATURDAY AFTERNOON ALTHOUGH FOR NOW BEST CONFIDENCE IS IN THE
SOUTHEAST. ANOTHER BLOB OF MID LEVEL MOISTURE TO MIGRATE OVER THE
SOUTHERN HALF OF THE STATE AND COULD NOT RULE OUT A FEW SPRINKLES
UNDERNEATH IT...BUT LEFT MENTION OUT OF FCST FOR NOW. IN FACT THE
ADJMET GUIDANCE DOES PAINT SOME LOW POPS OVER THE SOUTHWEST MTS.
INCREASED POPS SOMEWHAT SUNDAY ESPECIALLY ALONG THE CENTRAL MT
CHAIN. LEFT THE MENTION OF DRY CONVECTION FROM THE RGV WWD ALTHOUGH
COULD BE A MIX WITH AT LEAST SOME MEAGER MEASURABLE PCPN DEPENDING
IF THE SURGE IS AS STRONG AS DEPICTED SO FAR. HOWEVER...MONDAY
STARTS TO DRY OUT AND TUESDAY EVEN MORE SO. REMOVED THE POPS IN THE
EAST FOR TUESDAY NIGHT...AND PROBABLY SHOULD HAVE FOR TUESDAY AS
WELL AS RIGHT NOW IT LOOKS DRY. ANOTHER BACKDOOR FRONT WEDNESDAY
LOOKS TO PUSH INTO THE RGV WEDNESDAY NIGHT...SO POPS/WX GRIDS FOR
MID TO LATE WEEK HAVE BEEN UPDATED.
.FIRE WEATHER...
...WIDESPREAD CRITICAL FIRE WEATHER CONDITIONS DUE TO STRONG WIND
AND LOW HUMIDITY FOR MUCH OF NORTHERN AND CENTRAL NEW MEXICO THROUGH
FRIDAY...
...DRY LIGHTNING THREAT INCREASING SUNDAY CENTRAL/WEST...
MOVING INTO DAY 2 OF A PROTRACTED CRITICAL FIRE WEATHER PATTERN THAT
WILL EXTEND THROUGH FRIDAY. THEREAFTER...FAR LESS WIND BUT GROWING
CONFIDENCE IN A SUBSTANTIAL WESTERLY PUSH OF LOWER LEVEL MOISTURE
THAT WILL RESULT IN A SIGNIFICANT DRY LIGHTNING THREAT FOR
CENTRAL/WESTERN AREAS BY SUNDAY.
SATURDAY LOOKS TO BE A CLASSIC TRANSITION DAY AS RICHER LOW LEVEL
MOISTURE INITIALLY MAKES A RETURN TO THE EC/SE PLAINS AS SURFACE
WINDS VEER TO SELY AND TAPS INTO A NOW SEMI-PERMANENT POOL OF
GULFMEX MOISTURE. POTENTIAL FOR SOME DRIER STORMS ALONG THE EAST
SLOPES OF THE CENTRAL/SC MOUNTAIN SATURDAY PM. HIGHER DEW POINT AIR
ALSO CREEPING NORTHWARD ALONG THE RGV AND THAT COUPLED WITH A SUBTLE
AND ALWAYS SNEAKY UPTICK IN MID-LEVEL MOISTURE AS THE UPPER RIDGE
EXPANDS/BUILDS NORTHWARD COULD RESULT IN AT LEAST AN ISOLATED DRY
LIGHTNING THREAT OVER THE WC/SW HIGHER TERRAIN AS EARLY AS SATURDAY
AFTERNOON OR EVENING. THIS WILL BE CLOSELY MONITORED.
EVEN THE SLIGHTEST UPTICK IN LOWER/MID LEVEL MOISTURE IN THE
PRESENCE OF VERY STEEP LAPSE RATES THAT ARE TYPICAL OF THE
DEVELOPING PATTERN THIS WEEKEND SEEMS TO RESULT IN MORE THAN
EXPECTED BUILDUPS/VIRGA AND DRY CG/S. WE SHALL SEE. SUNDAY
AFTERNOON/EVENING LOOKING TO BE THE MORE CRITICAL DAY WITH RESPECT
TO DRY LIGHTNING FOR THE WEST THOUGH MONDAY COULD BE FAIRLY ACTIVE
EAST OF THE DIVIDE TO THE EAST SLOPES OF THE CENTRAL MOUNTAIN
CHAIN AS DRIER AIR ADVANCES EASTWARD.
IN THE MEANTIME...LARGE-SCALE UPPER TROUGH SLOWLY PIVOTING NORTHEAST
FROM THE CENTRAL/NORTHERN ROCKIES EARLY THIS MORNING. BASE OF THE
TROUGH TRANSLATED EASTWARD OVER OUR AREA THIS PAST NIGHT AND PRESENT
INDICATIONS ARE THAT THE STRONGEST MID-LEVEL WINDS WILL PASS
OVERHEAD BEFORE MIDDAY. THAT SAID...AN ANOMALOUSLY STRONG UPPER
LEVEL JET ORIENTED NW TO SE FROM THE GREAT BASIN TO THE FOUR CORNERS
REGION WILL NOT SHIFT NORTHWARD APPRECIABLY TODAY. AS A
RESULT...WIND SPEEDS THOUGH A BIT LESS THAN YESTERDAY WILL STILL BE
SIGNIFICANT WITH FREQUENT GUSTS OF 35-40 MPH ACROSS THE NORTH.
SURFACE LOW NOT AS FAVORABLE EITHER. NO CHANGES TO THE FIRE
WEATHER WATCH FOR FRIDAY THOUGH BELT OF STRONGEST WINDS DO SHIFT
SOUTHWARD PER PREVIOUS FORECAST. VERY DEEP MIXING CONTINUES TODAY
BEFORE MAX MIXING HEIGHTS TREND DOWNWARD SLIGHTLY ON FRIDAY. LOWEST
RH VALUES CENTRAL VALLEY CORRIDOR AND IN THE EAST.
EXTENDED MODELS STILL TRENDING DRIER/BREEZIER EARLY NEXT WORK WEEK
FOLLOWING OUR LIGHTNING PERIOD. BACK TO VERY DEEP MIXING AND GUSTY
AFTERNOON/EVENING PERIODS THOUGH TOO EARLY TO GAUGE STRENGTH OF ANY
SUSTAINED WINDY PERIODS. KJ
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR THE FOLLOWING
ZONES...NMZ101>104-106>108.
FIRE WEATHER WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING FOR
THE FOLLOWING ZONES...NMZ101>108.
WIND ADVISORY UNTIL 9 PM MDT THIS EVENING FOR THE FOLLOWING ZONES...
NMZ510>516-523-527>529.
&&
$$
50
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1257 PM CDT THU MAY 30 2013
.UPDATE...
ISSUED AT 1256 PM CDT THU MAY 30 2013
EARLY AFTERNOON UPDATE FOCUSES ON FINE TUNING POP TRENDS FOR
MAINLY THE SOUTH...WHERE THERE HAS BEEN ONLY ISOLATED SHOWERS
THROUGH THE DAY AFTER RECEIVING 3 TO 5 INCHES OVERNIGHT. SKIES ARE
CLEARING IN THE REGION...AND THEREFORE LIKING THE NAM SOLUTION
WHICH IS SLIGHTLY MORE UNSTABLE FOR LATE THIS AFTN INTO THE
EVENING. STILL THINK THERE IS A GOOD CHANCE FOR SCATTERED TSTMS IN
THE 21Z TO 03Z TIMEFRAME AND WILL MAINTAIN 30 TO 40 POPS. ALSO
UPDATED FOR NEW AVIATION DISCUSSION.
UPDATE ISSUED AT 1000 AM CDT THU MAY 30 2013
MORNING UPDATE FOCUSES ON FLOODING IN CLAY COUNTY MINNESOTA AND
POP TRENDS. RADAR CONTINUES TO SHOW A BAND OF SHOWERS ACROSS
NORTHWESTERN ZONES. INCREASED POPS IN THIS REGION AND DECREASED
POPS ACROSS THE SOUTHERN HALF OF THE CWA. HRRR DOES SHOW
REDEVELOPMENT OVER SOUTHEASTERN ZONES SO MAINTAINED
LIKELIES...HOWEVER WENT DOWN TO 30 POPS FOR SOUTHEASTERN ND AND
SOUTHERN VALLEY. WILL WAIT TO FURTHER ASSESS 12Z RUN BEFORE
CHANGING ANYTHING BEYOND 00Z FRIDAY. REPORTS OF FIVE TO SEVEN
INCHES ARE COMING IN ALONG THE BUFFALO RIVER BASIN TO INCLUDE THE
CITIES OF AVERILL AND DILWORTH. WILL EXTEND WARNING AREA IN TIME
BUT CHOP OFF CASS COUNTY AND NORMAN COUNTY...WHERE RADAR ESTIMATES
ARE ABOUT FOUR INCHES OR LESS WITH NO REPORTS OF OVERLAND FLOODING
FROM THOSE COUNTY MANAGERS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 355 AM CDT THU MAY 30 2013
THE MAIN CHALLENGE WILL BE SHOWER AND THUNDERSTORM CHANCES INTO
FRIDAY AND HEAVY RAIN POTENTIAL. THE MODELS ARE IN GOOD OVERALL
AGREEMENT BUT NOT PICKING UP TOO WELL ON MESOSCALE FEATURES.
FOR TODAY AND TONIGHT...EXPECT SHOWERS AND STORMS TO LIFT TO THE NORTH
AND LIKELY BECOME MORE FOCUSED IN THE NORTHERN AREAS. THERE WILL
BE A CHANCE FOR LOCALLY HEAVY RAINFALL NEAR ANY STORMS...GIVEN
PWATS OVER 1.5 INCHES. THERE COULD BE SOME STRONGER STORMS THIS
AFTERNOON IF SFC HEATING OCCURS...BUT I AGREE WITH SPC IN KEEPING
JUST 5% PROBS FOR HAIL/WIND AND NO SLIGHT RISK AT THIS TIME. THINK
THE MAIN ISSUE COULD BE HEAVY RAIN IF TRAINING ECHOES DEVELOPS.
HARD TO PINPOINT WHERE THIS MAY OCCUR...SO NO FLOOD HEADLINES
PLANNED...ALTHOUGH THERE COULD BE MORE FLOODING ISSUES NEAR
PERSISTENT HEAVY RAIN TODAY AND TONIGHT.
FOR FRIDAY...THE UPPER LOW WILL SLOWLY MOVE INTO THE AREA FROM THE
WEST AND EXPECT MORE WRAPAROUND SHOWERS AND SOME THUNDER. AGAIN
LOCALLY HEAVY RAINFALL IS POSSIBLE NEAR STRONGER SHOWERS AND
STORMS. IT WILL BE COOLER THAN TODAY WITH WINDS SHIFTING TO THE
NORTH BY AFTERNOON IN ALL BUT THE SOUTH AND EASTERN AREAS.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU MAY 30 2013
FOR FRI NIGHT INTO SAT...WRAPAROUND SHOWERS WILL CONTINUE BEFORE
IT DRIES OUT BY SAT AFTERNOON.
FOR SUNDAY THROUGH WEDNESDAY...EXPECT A LOW AMPLITUDE LONG WAVE
TROUGH OVER THE NORTHERN PLAINS TO SHIFT EAST. ECMWF AND GFS
GENERALLY AGREE TIMING WISE HOWEVER THE GFS IS A HIGHER AMPLITUDE
SOLUTION COMPARED TO THE ECMWF. WILL BLEND THE MODELS.
ECMWF HAS SLOWED DOWN FROM MODEL RUN TO MODEL RUN WHILE THE GFS HAS
SHIFTED PRECIP SOUTH WITH EACH RUN. WILL SLOW DOWN PRECIP FOR TUE AND
DECREASE POPS A BIT FOR MON AND MON NIGHT.
LITTLE CHANGE TO TEMPS FOR SUN THROUGH TUE. WED HIGH TEMP WAS
INCREASED BY 3 DEGREES IN THE NORTHWEST ZONES AND A DEGREE OR TWO
LOWER IN THE SOUTHERN ZONES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1256 PM CDT THU MAY 30 2013
COMPLEX SITUATION AS AN UPPER LOW MOVES ACROSS THE NORTHERN PLAINS.
MOST LOCATIONS HAVE HAD MVFR CEILINGS WITH SCATTERED SHOWERS MOVING
ACROSS THE FORECAST AREA. KEPT MOSTLY MVFR CEILINGS WITH VCSH OR
-SHRA BUT THERE COULD BE SOME IMPROVEMENTS TO VFR OR DROPS TO IFR AT
TIMES. VIS SHOULD ONLY BE LIMITED WHEN SHOWERS MOVE OVER. SOME
THUNDERSTORMS AND CB ARE ALSO POSSIBLE...MAINLY IN THE KFAR AREA
DURING THE LATE AFTERNOON AND EVENING. WINDS ACROSS THE
NORTHWESTERN FORECAST AREA WILL SHIFT TO THE NORTH AS THE SFC LOW
BEGINS TO MOVE EAST AND A COLD FRONT MOVES INTO THE AREA. AHEAD OF
THE FRONT WINDS WILL REMAIN OUT OF THE SOUTH AND EAST. THINK THAT
MOST LOCATIONS WILL BE MVFR OR IFR CEILINGS AND MVFR VIS WITH
SCATTERED RAIN SHOWERS THROUGH THE EARLY MORNING HOURS. SOME
IMPROVEMENT IS POSSIBLE TOWARDS THE END OF THE TAF PERIOD.
&&
.HYDROLOGY...
ISSUED AT 1256 PM CDT THU MAY 30 2013
A BAND OF HEAVY RAIN FELL OVERNIGHT FROM FARGO THROUGH NORTHEASTERN
CLAY COUNTY...WITH AMOUNTS GENERALLY RANGING FROM TWO TO FOUR
INCHES. REPORTS OF OVERLAND FLOODING IN THE VICINITY OF AVERILL AND
DILWORTH HAVE PROMPTED AN EXTENSION OF THE AREAL FLOOD WARNING
THROUGH 03Z FRIDAY. CASS COUNTY ND AND NORMAN COUNTY MN WERE REMOVED
FROM WARNING AREA AS THE THREAT OF OVERLAND FLOODING HAS ENDED IN
THOSE AREAS. OTHERWISE...FLOWS FROM THE HEAVY RAIN OVERLAND AND INTO
DITCHES AND STREAMS HAS WORKED ITS WAY INTO THE BUFFALO AND WILD
RICE RIVERS...PROMPTING A NEW RIVER FLOOD WARNING FOR THE WILD RICE
RIVER AT HENDRUM AFFECTING NORMAN COUNTY AND A CONTINUATION OF THE
RIVER FLOOD WARNING AT THE BUFFALO RIVER NEAR DILWORTH AFFECTING
CLAY COUNTY. SOME POINTS ON THE MAINSTEM RED RIVER AND A FEW
TRIBUTARIES ARE PROGGED TO RISE TO ACTION STAGE...AND ANTICIPATED
PCPN IS NOT EXPECTED TO AFFECT FORECAST LEVELS FOR NOW.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...SPEICHER
SHORT TERM...DK
LONG TERM...HOPPES/DK
AVIATION...JR
HYDROLOGY...HOPKINS
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1240 PM CDT THU MAY 30 2013
.UPDATE...
ISSUED AT 1127 AM CDT THU MAY 30 2013
WINDS IN NORTHEAST NEBRASKA INTO SOUTHEAST SOUTH DAKOTA AND NORTHWEST
IOWA REMAIN PRIMARILY SOUTHWEST THIS MORNING KEEPING A RELATIVELY DRY
LOW TO MID LEVELS UPSTREAM. WINDS ARE EXPECTED TO BACK A BIT THIS
AFTERNOON WITH THE ARRIVAL OF THE SURFACE TROUGH CURRENTLY SWINGING
THROUGH SOUTH CENTRAL SOUTH DAKOTA. WITH DAYTIME HEATING EARLY THIS
AFTERNOON...SHOWERS AND THUNDERSTORMS SHOULD REDEVELOP ACROSS THE
AREA AND TRACK EASTWARD. SHEAR IS NOT VERY IMPRESSIVE AT THIS
POINT...BUT THE LATEST RAP FORECAST SOUNDINGS SUGGEST THAT WE MAY
DESTABILIZE ENOUGH FOR SOME NARROW CAPE VALUES APPROACHING 1000 J/KG
BY LATE AFTERNOON. CANNOT RULE OUT THE POTENTIAL FOR A FEW MARGINALLY
SEVERE STORMS THIS AFTERNOON AND EVENING IN FAR SOUTHEAST SOUTH
DAKOTA AND NORTHWEST IOWA...WHERE MUCH MORE FAVORABLE SHEAR IS
EXPECTED TO SET UP AND MOISTURE IS MORE FAVORABLE WITH SOUTHERLY
WINDS. THE MAIN THREAT WITH STRONG TO SEVERE STORMS WILL BE DIME TO
QUARTER- SIZE HAIL. SEVERE OUTLOOK HOWEVER IS VERY CONDITIONAL AND
OVERALL NOT VERY IMPRESSIVE. MADE A QUICK UPDATE TO REMOVE POPS THIS
MORNING AND ADJUST CLOUDS SLIGHTLY. EVERYTHING ELSE IS ON TRACK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 359 AM CDT THU MAY 30 2013
WILL GO AHEAD AND CANCEL THE FLASH FLOOD WATCH FOR OUR
SOUTHEASTERN ZONES. REMNANTS OF LIGHT TO SPOTTY MODERATE RAINFALL
ARE MOVING NORTHWARD AT THIS TIME EAST OF I 29...BUT IT IS NOT
ENOUGH TO EXAGGERATE ANY EXISTING FLOODING PROBLEMS. IT IS LIKELY
THAT THE HEAVIEST RAINFALL FOR TODAY WILL ALSO STAY TO THE SOUTH
OF THE SIOUX FALLS FORECAST AREA. SYNOPTIC SITUATION SHOWS A HUGE
UPPER LOW IN TWO PIECES...GENERALLY EXTENDING FROM OFF THE BRITISH
COLUMBIA COAST TO THE NORTHWESTERN PLAINS. LARGE AREA OF SURFACE
LOW PRESSURE FOLLOWS SUIT AND IS SITUATED OVER CENTRAL SD...WITH
TROUGHING NUDGING DOWN INTO THE CENTRAL PLAINS. ANOTHER SURFACE LOW
IS SITUATED OVER THE OKLAHOMA PANHANDLE...WHICH IS THE RESULT OF A
VERY STRONG SHORTWAVE MOVING EASTWARD FROM THAT AREA TODAY...INTO
KANSAS...MISSOURI...SOUTHERN IOWA AREAS. THERE IS A LOT OF MODEL
CONSENSUS THAT THE HEAVIER RAIN WILL BE CONFINED TO THAT SHORT
WAVE AND SOUTH OF OUR AREA.
SO FROM HERE AND OUT...WE ARE MAINLY LEFTOVER WITH ISOLATED TO
SCATTERED INSTABILITY SHOWERS AND A FEW POSSIBLE THUNDERSTORMS...
ESPECIALLY THIS AFTERNOON. WENT DRY FOR OUR WESTERN ZONES THIS
MORNING AS THERE IS SIMPLY NO SIGN OF CONVECTIVE REDEVELOPMENT YET
IN CENTRAL NEB. THE 850MB STREAMLINES PRETTY MUCH TELL THE STORY
FOR NOW...IN THAT THEY ARE WRAPPING FROM A WESTERLY DIRECTION
UNDERNEATH THE AFOREMENTIONED LOW...COMING OUT OF WESTERN AND
CENTRAL NEBRASKA AND INTO OUR WESTERN ZONES. SO THE MOIST LOW
LEVEL FLOW IS CUTOFF IN OUR WEST. ALONG AND EAST OF I 29...THE LOW
LEVEL JET STILL EXISTS BUT IS WEAKER THEN YESTERDAY. ML CAPE IS
PRETTY ANEMIC THIS MORNING...BUT DOES INCREASE THIS AFTERNOON AS
ANY CLEARING WILL HELP TO HEAT THINGS OUT. IN ADDITION...SOME OF
THE HIGHER RESOLUTION MODELS ARE STRONGLY HINTING AT THE SURFACE
TROUGH MOVING EASTWARD INTO THE JAMES RIVER VALLEY THIS
AFTERNOON...WITH A DRY LINE PRESSING THROUGH OUR SOUTH CENTRAL SD
ZONES. THE TROUGH MAY PROVIDE A FOCUS FOR SCATTERED SHOWERS AND
STORMS ALONG AN AXIS FROM YANKTON TO SIOUX FALLS AND VICINITIES...
HELPED BY STRONGLY VEERING PROFILES JUST AHEAD OF THE DRY LINE.
ELSEWHERE AS THE AFTERNOON PROGRESSES...POPCORN TYPE INSTABILITY
SHOWERS AND THUNDERSTORMS SHOULD DOMINATE THIS AREA OF THE
SCATTERED VARIETY. SO VERY MUCH A NUISANCE SITUATION. HIGHS TODAY
STILL LOOK LIKE WIDESPREAD 70S...WHICH SHOULD BE ENOUGH TO PROVIDE
SOME AFTERNOON INSTABILITY.
FOR TONIGHT...ONCE THE HEATING SUBSIDES...SO WILL OUR CHANCE FOR
INSTABILITY RAINFALL. BUT LATE TONIGHT...THE UPPER LOW BEGINS TO
WRAP IN A CHANCE FOR SHOWERS INTO OUR NORTHWEST AREAS. MOISTURE
PROFILES IN THAT AREA ARE QUITE HIGH BY LATE TONIGHT...WITH DRY
SLOTTING TAKING OVER AFTER MIDNIGHT FOR THE REST OF OUR FORECAST
AREA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 359 AM CDT THU MAY 30 2013
ON FRIDAY AND SATURDAY...OUR WEATHER WILL CONTINUE TO BE DOMINATED
BY THE UPPER LOW. IT WILL STILL BE CLOSED ON FRIDAY AS IT MOVES
SLOWLY EASTWARD. THEN IT WILL BECOME A TROUGH ON SATURDAY AS IT
MOVES INTO THE NORTHERN MISSISSIPPI VALLEY. PV IS VERY STRONG ON
THE NORTH AND WEST SIDES OF THE UPPER LOW...ALONG WITH STRONG
TROWALING CLEARLY EVIDENT AT THE MID LEVELS. ALL OF THIS IS
CAUSING A HIGH MOISTURE PROFILE WHICH MOVES SOUTHEASTWARD...SO
EXPECT LIGHT SHOWERS LIKELY TO MOVE IN THAT DIRECTION THROUGH
TIME AND EVENTUALLY ENCOMPASSING ALMOST THE ENTIRE WESTERN HALF OF
OUR FORECAST AREA. MODELS ARE CERTAINLY SHOWING QUITE A CONVEYOR
BELT OF PRECIPITATION...MOVING NORTHEASTWARD AHEAD OF THE LOW FROM
THE SOUTHERN PLAINS INTO THE GREAT LAKES...THEN LIGHT RAIN ARCHING
BACK THROUGH PARTS OF THE NORTHERN AND WESTERN PLAINS ALONG THE
TROWALING.
ANOTHER THING TO WATCH FOR FRIDAY AFTERNOON...IS THAT THE LEADING
EDGE OF THE COLD FRONT COULD SPARK SOME SCATTERED THUNDERSTORMS
ALONG AND SOUTH OF A SIOUX CITY TO WINDOM MN LINE. DO NOT THINK
THE COVERAGE OF STORMS WILL BE ALL THAT GREAT...AND ALMOST WENT
ISOLATED. BUT AGAIN SOMETHING TO WATCH FOR.
THIS COLD FRONT MOVES EASTWARD AND WILL GIVE OUR FORECAST AREA
SOME VERY CHILLY AIR TO CONTEND WITH ON SATURDAY. SATURDAY DOES
NOT LOOK LIKE A PLEASANT DAY...AS EVEN IF LIGHT SHOWERS DO NOT OCCUR
AT YOUR LOCATION...IT WILL BE CONSIDERABLY CLOUDY AND WINDY ALONG
WITH THE VERY CHILLY TEMPERATURES. RECORD LOW HIGHS ON JUNE 1 ARE
QUITE A BIT COLDER THAN WHAT WE HAVE FORECAST HOWEVER...SO THEY
SHOULD NOT BE IN JEOPARDY OF FALLING. SOME OF THE LIGHT SHOWERS BY
SATURDAY AFTERNOON WILL BE THE RESULT OF WHAT HEATING THERE IS.
THEREFORE BY SATURDAY NIGHT...ELIMINATED ALL POPS IN OUR EASTERN
ZONES. CONCERNING TEMPERATURES...COOLED OFF OUR WESTERN ZONES A
FAIR AMOUNT ON FRIDAY BEHIND THE COLD FRONT...NOTING THE CLOUDY
AND SHOWERY CONDITIONS.
THE SUNDAY THROUGH WEDNESDAY PERIOD WILL START DRY AND COOL
SUNDAY...BUT THE COOL WILL FEEL NICE WITH LIGHT TO MODERATE
NORTHERLY WINDS BEGINNING TO TURN EASTERLY AS SURFACE RIDGE PASSES
BY TO THE NORTH. WAS LOOKING FOR MONDAY TO BE DRY AND A LITTLE
WARMER...BUT IT LOOKS LIKE SOUTHEASTERLY THERMAL LIFT PATTERN WILL
DEVELOP SOON ENOUGH TO MENTION A SMALL CHANCE OF STORMS. THIS CHANCE
SHOULD BE SOMEWHAT BIGGER FOR THE REST OF THE PERIOD...MONDAY NIGHT
INTO WEDNESDAY...AS UPPER WAVE DIGS FROM SOUTHWEST CANADA INTO
THE DAKOTAS. WILL GO WITH GUIDANCE KEEPING TEMPERATURES FAIRLY
CLOSE TO SEASONAL FOR NOW...THIS SEEMS IN LINE WITH THE NEW ECMWF.
THE GFS WOULD SUGGEST COOLER BY WEDNESDAY. SINCE NO TREND IS SEEN
AS TO WHICH MODEL IS BETTER THAT FAR AHEAD...GUIDANCE AND
CONSISTENCY WIN FOR NOW. FOR THE MOMENT DO NOT EXPECT MOISTURE
INFLOW TO BE ENOUGH FOR SEVERE STORMS OR HEAVY RAIN...BUT MID AND
UPPER FLOW WILL BE MORE THAN AMPLE SO WILL HAVE TO BE OPEN TO
POSSIBLE CHANGE OF THINKING IN COMING DAYS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1233 PM CDT THU MAY 30 2013
VFR CONDITIONS WILL BE PREDOMINATE FOR MOST AREAS...HOWEVER BRIEF
DIPS TO 1500 TO 3000 FEET IN SCATTERED SHOWERS AND THUNDERSTORMS WILL
BE POSSIBLE THROUGH AROUND 03Z FRIDAY. LEFT OUT MENTION OF SHOWERS
AND THUNDERSTORMS IN TAFS AS ACTIVITY WILL BE VERY SPOTTY AND LIKELY
VERY BRIEF. THE FAR NORTHWEST CORNER OF THE FORECAST AREA...INCLUDING
KHON COULD DROP TO MORE PREDOMINATE MVFR CEILINGS AFTER 09Z...BUT
GUIDANCE REMAINS A BIT UNCERTAIN WITH THE TIMING OF THESE LOWER
CEILINGS. WINDS WILL ALSO TURN MORE SOUTHWESTERLY TONIGHT AND BECOME
BREEZY DURING THE DAYLIGHT HOURS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...
SHORT TERM...MJF
LONG TERM...MJF/WILLIAMS
AVIATION...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1127 AM CDT THU MAY 30 2013
.UPDATE...
ISSUED AT 1127 AM CDT THU MAY 30 2013
WINDS IN NORTHEAST NEBRASKA INTO SOUTHEAST SOUTH DAKOTA AND NORTHWEST
IOWA REMAIN PRIMARILY SOUTHWEST THIS MORNING KEEPING A RELATIVELY DRY
LOW TO MID LEVELS UPSTREAM. WINDS ARE EXPECTED TO BACK A BIT THIS
AFTERNOON WITH THE ARRIVAL OF THE SURFACE TROUGH CURRENTLY SWINGING
THROUGH SOUTH CENTRAL SOUTH DAKOTA. WITH DAYTIME HEATING EARLY THIS
AFTERNOON...SHOWERS AND THUNDERSTORMS SHOULD REDEVELOP ACROSS THE
AREA AND TRACK EASTWARD. SHEAR IS NOT VERY IMPRESSIVE AT THIS
POINT...BUT THE LATEST RAP FORECAST SOUNDINGS SUGGEST THAT WE MAY
DESTABILIZE ENOUGH FOR SOME NARROW CAPE VALUES APPROACHING 1000 J/KG
BY LATE AFTERNOON. CANNOT RULE OUT THE POTENTIAL FOR A FEW MARGINALLY
SEVERE STORMS THIS AFTERNOON AND EVENING IN FAR SOUTHEAST SOUTH
DAKOTA AND NORTHWEST IOWA...WHERE MUCH MORE FAVORABLE SHEAR IS
EXPECTED TO SET UP AND MOISTURE IS MORE FAVORABLE WITH SOUTHERLY
WINDS. THE MAIN THREAT WITH STRONG TO SEVERE STORMS WILL BE DIME TO
QUARTER- SIZE HAIL. SEVERE OUTLOOK HOWEVER IS VERY CONDITIONAL AND
OVERALL NOT VERY IMPRESSIVE. MADE A QUICK UPDATE TO REMOVE POPS THIS
MORNING AND ADJUST CLOUDS SLIGHTLY. EVERYTHING ELSE IS ON TRACK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 359 AM CDT THU MAY 30 2013
WILL GO AHEAD AND CANCEL THE FLASH FLOOD WATCH FOR OUR
SOUTHEASTERN ZONES. REMNANTS OF LIGHT TO SPOTTY MODERATE RAINFALL
ARE MOVING NORTHWARD AT THIS TIME EAST OF I 29...BUT IT IS NOT
ENOUGH TO EXAGGERATE ANY EXISTING FLOODING PROBLEMS. IT IS LIKELY
THAT THE HEAVIEST RAINFALL FOR TODAY WILL ALSO STAY TO THE SOUTH
OF THE SIOUX FALLS FORECAST AREA. SYNOPTIC SITUATION SHOWS A HUGE
UPPER LOW IN TWO PIECES...GENERALLY EXTENDING FROM OFF THE BRITISH
COLUMBIA COAST TO THE NORTHWESTERN PLAINS. LARGE AREA OF SURFACE
LOW PRESSURE FOLLOWS SUIT AND IS SITUATED OVER CENTRAL SD...WITH
TROUGHING NUDGING DOWN INTO THE CENTRAL PLAINS. ANOTHER SURFACE LOW
IS SITUATED OVER THE OKLAHOMA PANHANDLE...WHICH IS THE RESULT OF A
VERY STRONG SHORTWAVE MOVING EASTWARD FROM THAT AREA TODAY...INTO
KANSAS...MISSOURI...SOUTHERN IOWA AREAS. THERE IS A LOT OF MODEL
CONSENSUS THAT THE HEAVIER RAIN WILL BE CONFINED TO THAT SHORT
WAVE AND SOUTH OF OUR AREA.
SO FROM HERE AND OUT...WE ARE MAINLY LEFTOVER WITH ISOLATED TO
SCATTERED INSTABILITY SHOWERS AND A FEW POSSIBLE THUNDERSTORMS...
ESPECIALLY THIS AFTERNOON. WENT DRY FOR OUR WESTERN ZONES THIS
MORNING AS THERE IS SIMPLY NO SIGN OF CONVECTIVE REDEVELOPMENT YET
IN CENTRAL NEB. THE 850MB STREAMLINES PRETTY MUCH TELL THE STORY
FOR NOW...IN THAT THEY ARE WRAPPING FROM A WESTERLY DIRECTION
UNDERNEATH THE AFOREMENTIONED LOW...COMING OUT OF WESTERN AND
CENTRAL NEBRASKA AND INTO OUR WESTERN ZONES. SO THE MOIST LOW
LEVEL FLOW IS CUTOFF IN OUR WEST. ALONG AND EAST OF I 29...THE LOW
LEVEL JET STILL EXISTS BUT IS WEAKER THEN YESTERDAY. ML CAPE IS
PRETTY ANEMIC THIS MORNING...BUT DOES INCREASE THIS AFTERNOON AS
ANY CLEARING WILL HELP TO HEAT THINGS OUT. IN ADDITION...SOME OF
THE HIGHER RESOLUTION MODELS ARE STRONGLY HINTING AT THE SURFACE
TROUGH MOVING EASTWARD INTO THE JAMES RIVER VALLEY THIS
AFTERNOON...WITH A DRY LINE PRESSING THROUGH OUR SOUTH CENTRAL SD
ZONES. THE TROUGH MAY PROVIDE A FOCUS FOR SCATTERED SHOWERS AND
STORMS ALONG AN AXIS FROM YANKTON TO SIOUX FALLS AND VICINITIES...
HELPED BY STRONGLY VEERING PROFILES JUST AHEAD OF THE DRY LINE.
ELSEWHERE AS THE AFTERNOON PROGRESSES...POPCORN TYPE INSTABILITY
SHOWERS AND THUNDERSTORMS SHOULD DOMINATE THIS AREA OF THE
SCATTERED VARIETY. SO VERY MUCH A NUISANCE SITUATION. HIGHS TODAY
STILL LOOK LIKE WIDESPREAD 70S...WHICH SHOULD BE ENOUGH TO PROVIDE
SOME AFTERNOON INSTABILITY.
FOR TONIGHT...ONCE THE HEATING SUBSIDES...SO WILL OUR CHANCE FOR
INSTABILITY RAINFALL. BUT LATE TONIGHT...THE UPPER LOW BEGINS TO
WRAP IN A CHANCE FOR SHOWERS INTO OUR NORTHWEST AREAS. MOISTURE
PROFILES IN THAT AREA ARE QUITE HIGH BY LATE TONIGHT...WITH DRY
SLOTTING TAKING OVER AFTER MIDNIGHT FOR THE REST OF OUR FORECAST
AREA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 359 AM CDT THU MAY 30 2013
ON FRIDAY AND SATURDAY...OUR WEATHER WILL CONTINUE TO BE DOMINATED
BY THE UPPER LOW. IT WILL STILL BE CLOSED ON FRIDAY AS IT MOVES
SLOWLY EASTWARD. THEN IT WILL BECOME A TROUGH ON SATURDAY AS IT
MOVES INTO THE NORTHERN MISSISSIPPI VALLEY. PV IS VERY STRONG ON
THE NORTH AND WEST SIDES OF THE UPPER LOW...ALONG WITH STRONG
TROWALING CLEARLY EVIDENT AT THE MID LEVELS. ALL OF THIS IS
CAUSING A HIGH MOISTURE PROFILE WHICH MOVES SOUTHEASTWARD...SO
EXPECT LIGHT SHOWERS LIKELY TO MOVE IN THAT DIRECTION THROUGH
TIME AND EVENTUALLY ENCOMPASSING ALMOST THE ENTIRE WESTERN HALF OF
OUR FORECAST AREA. MODELS ARE CERTAINLY SHOWING QUITE A CONVEYOR
BELT OF PRECIPITATION...MOVING NORTHEASTWARD AHEAD OF THE LOW FROM
THE SOUTHERN PLAINS INTO THE GREAT LAKES...THEN LIGHT RAIN ARCHING
BACK THROUGH PARTS OF THE NORTHERN AND WESTERN PLAINS ALONG THE
TROWALING.
ANOTHER THING TO WATCH FOR FRIDAY AFTERNOON...IS THAT THE LEADING
EDGE OF THE COLD FRONT COULD SPARK SOME SCATTERED THUNDERSTORMS
ALONG AND SOUTH OF A SIOUX CITY TO WINDOM MN LINE. DO NOT THINK
THE COVERAGE OF STORMS WILL BE ALL THAT GREAT...AND ALMOST WENT
ISOLATED. BUT AGAIN SOMETHING TO WATCH FOR.
THIS COLD FRONT MOVES EASTWARD AND WILL GIVE OUR FORECAST AREA
SOME VERY CHILLY AIR TO CONTEND WITH ON SATURDAY. SATURDAY DOES
NOT LOOK LIKE A PLEASANT DAY...AS EVEN IF LIGHT SHOWERS DO NOT OCCUR
AT YOUR LOCATION...IT WILL BE CONSIDERABLY CLOUDY AND WINDY ALONG
WITH THE VERY CHILLY TEMPERATURES. RECORD LOW HIGHS ON JUNE 1 ARE
QUITE A BIT COLDER THAN WHAT WE HAVE FORECAST HOWEVER...SO THEY
SHOULD NOT BE IN JEOPARDY OF FALLING. SOME OF THE LIGHT SHOWERS BY
SATURDAY AFTERNOON WILL BE THE RESULT OF WHAT HEATING THERE IS.
THEREFORE BY SATURDAY NIGHT...ELIMINATED ALL POPS IN OUR EASTERN
ZONES. CONCERNING TEMPERATURES...COOLED OFF OUR WESTERN ZONES A
FAIR AMOUNT ON FRIDAY BEHIND THE COLD FRONT...NOTING THE CLOUDY
AND SHOWERY CONDITIONS.
THE SUNDAY THROUGH WEDNESDAY PERIOD WILL START DRY AND COOL
SUNDAY...BUT THE COOL WILL FEEL NICE WITH LIGHT TO MODERATE
NORTHERLY WINDS BEGINNING TO TURN EASTERLY AS SURFACE RIDGE PASSES
BY TO THE NORTH. WAS LOOKING FOR MONDAY TO BE DRY AND A LITTLE
WARMER...BUT IT LOOKS LIKE SOUTHEASTERLY THERMAL LIFT PATTERN WILL
DEVELOP SOON ENOUGH TO MENTION A SMALL CHANCE OF STORMS. THIS CHANCE
SHOULD BE SOMEWHAT BIGGER FOR THE REST OF THE PERIOD...MONDAY NIGHT
INTO WEDNESDAY...AS UPPER WAVE DIGS FROM SOUTHWEST CANADA INTO
THE DAKOTAS. WILL GO WITH GUIDANCE KEEPING TEMPERATURES FAIRLY
CLOSE TO SEASONAL FOR NOW...THIS SEEMS IN LINE WITH THE NEW ECMWF.
THE GFS WOULD SUGGEST COOLER BY WEDNESDAY. SINCE NO TREND IS SEEN
AS TO WHICH MODEL IS BETTER THAT FAR AHEAD...GUIDANCE AND
CONSISTENCY WIN FOR NOW. FOR THE MOMENT DO NOT EXPECT MOISTURE
INFLOW TO BE ENOUGH FOR SEVERE STORMS OR HEAVY RAIN...BUT MID AND
UPPER FLOW WILL BE MORE THAN AMPLE SO WILL HAVE TO BE OPEN TO
POSSIBLE CHANGE OF THINKING IN COMING DAYS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 638 AM CDT THU MAY 30 2013
WIDESPREAD TO AREAS OF CEILINGS 1-3K FEET MOSTLY FROM A
BKX/FSD/SUX LINE AND EAST SHOULD IMPROVE FROM THE WEST 15Z-18Z.
OTHERWISE VFR WILL BE THE RULE OVER THE AREA WITH BRIEF CEILIGNS
2-3K FEET AND VISIBILITIES 3-5SM IN SGACTTERED TO ISOLATED
SHOWERS. ISOLATED THUNDERSTORMS POSSIBLE 18Z-31/02Z. WIDESPREAD
CEILINGS 2-3K FEET MAY DEVELOP WESTERN EDGE OF FORECAST AREA AFTER
31/06Z.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...
SHORT TERM...MJF
LONG TERM...MJF/WILLIAMS
AVIATION...
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
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.
&&
$$
04/07/07
AREA FORECAST DISCUSSION...CORRECTED
NWS MILWAUKEE/SULLIVAN WI
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.
&&
$$
TONIGHT/FRIDAY AND AVIATION/MARINE...MRC
FRIDAY NIGHT THROUGH THURSDAY...HENTZ
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
159 PM CDT THU MAY 30 2013
.UPDATE...
18Z DVN SOUNDING CAME IN WITH SBCAE AROUND 2000 J/KG AND INCREASE
IN FLOW IN THE LOWEST 6 KM. 50-60 KNOT WINDS WERE NOTED IN THE
800-500 MB LAYER. FLOW WAS MAINLY UNIDIRECTIONAL AND THE PRIMARY
WEAKNESS FOR TORNADIC SUPERCELLS WAS THE WEAK FLOW UP AROUND ANVIL
LEVEL...WHICH WOULD FAVOR HP TYPE STORMS WITH MORE WIND THREAT.
HOWEVER...0-3KM SHEAR OF 30-40 KNOTS WOULD SUPPORT THREAT FOR
MESOVORTEX/QLCS TORNADO THREAT GIVEN LCL OF 1000M OR LESS AND
0-1KM SHEAR OF 20-25 KNOTS.
RUC13 1 HOUR FORECAST FOR 19Z HAS SIG TORNADO PARAMETER OF 3-4
ACROSS NORTHERN ILLINOIS WITH VALUES OF 1-2 ACROSS SOUTHERN
WISCONSIN. THUS CONTINUED THREAT FOR WIND DAMAGE...TORNADOES...AND
SEVERE HAIL FOR NEXT FEW HOURS.
HIGH LEVEL FLOW SHOULD INCREASE ON NOSE OF DIFFLUENT UPPER JET BY
THIS EVENING AND WOULD SUPPORT INCREASING THREAT FOR TORNADIC
SUPERCELLS IF THE ACTIVITY CAN REMAIN DISCRETE.
&&
.PREV DISCUSSION... /ISSUED 1259 PM CDT THU MAY 30 2013/
UPDATE...
TORNADO WATCH IN EFFECT FOR SOUTH CENTRAL WI...INCLUDING
MARQUETTE/GREEN LAKE COUNTIES THROUGH DANE AND ROCK COUNTIES AND
WEST TO SAUK AND LAFAYETTE COUNTIES. SCATTERED CONVECTION IS
DEVELOPING IN SOUTH CENTRAL WI AS THE 850MB LOW LEVEL JET POINTS
INTO THE REGION. DEEP SHEAR IS STILL WEAK...BUT LOW LEVEL SHEAR IS
HIGH IN THE 20 TO 30 KNOT RANGE. 0-3KM CAPE IS DECENT WITH VALUES OVER
100 J/KG.
ENVIRONMENT IS CONDUCIVE FOR RAPID INTENSIFICATION OF ISOLATED
STORMS. THE LOW LCL AND HIGH 0-3 AND 0-1 HELICITY VALUES SUPPORT
TORNADO POTENTIAL. LARGE HAIL IS LIKELY IN THESE ISOLATED CELLS AS
WELL. CIMSS CLOUD TOP COOLING HIGHLIGHTED AN AREA OF RAPID COOLING
IN WESTERN SAUK COUNTY AT 1225 PM AND A SEVERE THUNDERSTORM WARNING
WAS ISSUED ON IT FOR 1-INCH HAIL A FEW MINUTES AGO.
THE 16Z HRRR SHOWS SCATTERED CONVECTION OVER SOUTH CENTRAL WI
EVOLVING INTO A LINE OVER SOUTHEAST WI AROUND 21Z. THE STRONG VORT
MAX SWINGING UP HERE LATER SHOWS ANOTHER CELL/LINE EVOLUTION MOVING
THROUGH NORTHERN IL AND SOUTHERN WI THIS EVENING.
PREV DISCUSSION... /ISSUED 1043 AM CDT THU MAY 30 2013/
UPDATE...
WE ARE RAMPING UP THE SEVERE THREAT FOR SOUTH CENTRAL WI FOR THIS
AFTERNOON. THERE IS A HIGH PROBABILITY OF STRONG THUNDERSTORMS IN
THE UPPER MIDWEST...AND A GOOD CHANCE OF SEVERE WINDS IN SOUTH
CENTRAL WI. SOUTHERN WISCONSIN IS BACK IN THE SLIGHT RISK FOR SEVERE
WEATHER AREA TODAY/TONIGHT.
A STRONG SHORTWAVE CURRENTLY OVER OKLAHOMA WILL BE SWINGING UP INTO
IOWA AROUND 21Z THIS AFTERNOON. THERE IS A WEAKER SHORTWAVE OUT
AHEAD OF THAT WHICH WILL GET INTO EASTERN IOWA/SOUTHERN WI JUST
AFTER 18Z. THE LEADING SHORTWAVE WILL NEED TO BE WATCHED FOR EARLY
AFTERNOON CONVECTION OVER SOUTH CENTRAL WI. THE MAIN STRONG
SHORTWAVE WILL LIKELY DRIVE A THUNDERSTORM COMPLEX ACROSS ALL OF
SOUTHERN WISCONSIN LATE AFTERNOON EARLY EVENING.
THE SPC STORM SCALE ENSEMBLE OF OPPORTUNITY SHOWS A TONGUE OF HIGH
PROBABILITY OF UPDRAFT HELICITY VALUES GREATER THAN 25 M2/S2
STRETCHING INTO CENTRAL WISCONSIN. THE HIGHEST VALUES ARE FOCUSED
OVER THE PLAINS AND EASTERN IOWA...BUT THE 60-70 PERCENTS OVER SOUTH
CENTRAL WI ARE STILL VERY IMPRESSIVE. THE CRAVEN-WIEDENFELD
AGGREGATE SEVERE PARAMETER WHICH COMPILES INGREDIENTS FOR SEVERE
THUNDERSTORMS AND GIVES A SCORE/PERCENTAGE CONTINUES TO HAVE VERY
HIGH VALUES IN SOUTHWEST AND SOUTH CENTRAL WI IN THE 75-82 PERCENT
RANGE...WITH RUC13 VALUES EVEN HIGHER. IN ADDITION...CIPS ANALOGS
SHOW A HISTORY OF SEVERE WEATHER OCCURRING WITH THE CURRENT SYNOPTIC
PATTERN.
MODE OF CONVECTION IS STILL IN QUESTION. THE MOST LIKELY MODE IS
LINES OF STORMS PRODUCING BOWING SEGMENTS. THE SHEAR IS RELATIVELY
WEAK OVER THE REGION AND UNIDIRECTIONAL. IT IS FORECAST TO
STRENGTHEN THROUGH THE AFTERNOON...AS WILL LOW LEVEL WIND
SHEAR...WHICH WOULD HELP CELLS REMAIN MORE DISCRETE OR HAVE JUST
SMALL BOWING LINE SEGMENTS. TORNADO DEVELOPMENT WILL BE POSSIBLE
GIVEN LOW LCL AND HIGH LOW LEVEL SHEAR. THE WIDESPREAD CUMULUS
CLOUDS THAT DEVELOPED THIS MORNING WILL ACTUALLY HELP THE SEVERE
SITUATION BY KEEPING US FROM MIXING OUT TOO MUCH AND ALLOWING THE
DEWPOINTS TO REMAIN HIGH.
THE 13Z HRRR IS SHOWING A MORE DISCRETE MODE OVER SOUTHERN WI EARLY
THIS AFTERNOON...WITH A SQUALL LINE/MCS DEVELOPING WITH THE BIGGER
VORT MAX LATE THIS AFTERNOON/EVENING. THE QUAD CITIES NWS OFFICE
WILL BE DOING AN 18Z UPPER AIR SOUNDING TO ALLOW US TO BETTER ASSESS
THE SEVERE POTENTIAL.
AVIATION/18Z TAFS/...
EXPECT GUSTS BETWEEN 25 AND 30 KTS TO LAST THROUGH MOST OF THE DAY.
MVFR BROKEN CUMULUS CLOUDS DEVELOPED AND WILL GRADUALLY LIFT TO VFR
BY 18Z.
STORMS WILL DEVELOP OVER EASTERN IOWA AND MOVE NORTHEAST INTO
SOUTHERN WISCONSIN EARLY THIS AFTERNOON. MADISON WILL HAVE THE BEST
CHANCE FOR EARLIER THUNDERSTORMS. SOME MAY BE SEVERE. THEN ANOTHER
ROUND OF THUNDERSTORMS IS EXPECTED LATE AFTERNOON/EARLY EVENING AND
THESE WILL LIKELY SPREAD ALL THE WAY INTO SOUTHEAST WI.
STRAIGHT-LINE WINDS ARE THE MAIN SEVERE WEATHER THREAT.
MARINE...
GUSTY SOUTH WINDS DUE TO MIXING OVER THE LAND WILL AFFECT SHORELINE
NEARSHORE AREAS ALL DAY TODAY. MAY NEED A SMALL CRAFT ADVISORY TO
HANDLE THIS. 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. STABLE AIR
DOWN AT LAKE LEVEL WILL KEEP WAVES FROM RESPONDING TOO MUCH TO THE
GUSTY WINDS.
PREV DISCUSSION... /ISSUED 449 AM CDT THU MAY 30 2013/
TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM
CONVECTION HAS LIFTED NORTH OF THE FORECAST AREA WITH SHORT WAVE/MCV
AND ADDITIONAL SUPPORT FROM RIGHT ENTRANCE REGION OF UPPER JET.
MODELS DAMPEN FIRST SHORT WAVE CURRENTLY DRIVING SRN PLAINS
CONVECTION AND FOCUS ON WAVE NEAR THE PANHANDLE REGION THAT WILL
SWING UP TOWARDS IA/NEB BY 00Z FRI AS 500 MB LOW GOES NEGATIVE-TILT.
WITH COMBINATION OF CENTRAL PLAINS SHORT WAVE/MCV AND 850 MB JET MAX
AND INSTABILITY ON AREA SOUNDINGS...THOUGH CAPE VALUES MAY BE A BIT
TOO HIGH DUE TO GENEROUS SURFACE DEW POINTS...WILL FOLLOW CONSENSUS
BLEND POPS AND INCREASE PRECIPITATION CHANCES RAPIDLY THROUGH THE
MORNING. HIGH POPS CONTINUE INTO THE EVENING...THEN TAPER OFF AS
FORCING WITH WAVE AND LOW-LEVEL JET MAX LIFT OFF TOP THE NORTHEAST.
WILL HAVE TO WATCH WESTERN COUNTIES OF S CENTRAL WI FOR FLASH
FLOODING POTENTIAL AFTER RECEIVING HEAVY RAIN WITH THE CONVECTION
WEDNESDAY EVENING.
LATEST SPC DAY 1 OUTLOOK HAS SHIFTED SLIGHT RISK TO THE SOUTHWEST
OUT OF OF WISCONSIN AS FAVORABLE SHEAR FOR ROTATING CELLS LESSENS
THROUGH THE DAY...BUT AN ISOLATED WIND/HAIL MAKER NOT OUT OF THE
QUESTION.
FRIDAY AND SATURDAY...FORECAST CONFIDENCE...MEDIUM
SOUTHERN WISCONSIN WILL REMAIN IN THE WARM SECTOR FRIDAY AS LOW
PRESSURE OVER NORTH DAKOTA AND MINNESOTA REMAINS NEARLY
STATIONARY. SHOWERS AND STORMS ARE THUS LIKELY ONCE AGAIN. THOUGH
THE BEST LOW LEVEL FLOW WILL BE TO THE SOUTH AND EAST...STRONGER
STORMS ARE NOT OUT OF THE QUESTION WITH SIMILAR UP TO 1000 J/KG OF
SURFACE BASED CAPE...AND WIND SHEAR ACTUALLY A BIT HIGHER THAN
PREVIOUS DAYS. LOOKS LIKE BEST CHANCE FOR SHOWERS AND STORMS WILL
BE LATE AFTERNOON INTO THE NIGHT...AS ANOTHER SHORTWAVE ROTATES
THROUGH THE AREA.
TEMPERATURES WILL BE SIMILAR FRIDAY AS THURSDAY...PUSHING OR
REACHING 80 MOST PLACES. PROBABLY A BIT TRICKY NEAR THE LAKE AGAIN
UNDER SOUTHERLY WINDS...BUT MOST AREAS SHOULD SEE THE WARMER TEMPS.
WEAKENING LOW PRESSURE WILL FINALLY DRAG A COLD FRONT THROUGH
SOUTHERN WISCONSIN BY SATURDAY NIGHT. MODELS HAVE SLOWED A BIT WITH
THE FRONT...SO TEMPS AND POPS HAVE TRENDED IT BIT HIGHER WITH
SOUTHERN WISCONSIN REMAINING IN THE WARM SECTOR A BIT LONGER.
SUNDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE...MEDIUM
MAIN UPPER LEVEL TROUGH AXIS WILL MOVE THROUGH SUNDAY...POSSIBLY
BRINGING A FEW SHOWERS. COOLER AIR IS EXPECTED TO ARRIVE WITH THE
SHORTWAVE...WITH TEMPERATURES FALLING BACK BELOW NORMAL.
SHOULD BE PLEASANT MONDAY UNDER HIGH PRESSURE...WITH A CHANCE FOR
SHOWERS AND STORMS RETURNING LATER TUESDAY INTO WEDNESDAY. HIGHS
WILL LIKELY REMAIN A FEW DEGREES BELOW NORMAL THROUGH THE FIRST HALF
OF NEXT WEEK.
AVIATION/12Z TAFS/...
WILL KEEP WIND SHEAR IN ALL OF THE TAFS...WITH WIND PROFILERS
PICKING UP 35 TO 40 KT WINDS BETWEEN 1500-2000 FT...UNTIL SURFACE
WINDS INCREASE WITH MIXING AFTER DAYBREAK. EXPECT SOUTHERLY GUSTS
BETWEEN 25 AND 30 KTS BY MID-MORNING AND LASTING THROUGH MOST OF
THE DAY.
INCREASED LOW-LEVEL MOISTURE AND COOLING EFFECTS OF LAST NIGHT/S
STORMS HAVE PRODUCED FOG AT KMSN WHICH SHOULD LIFT WITH INCREASING
WINDS AFTER SUNRISE. OTHERWISE VFR CONDITIONS THROUGH MOST OF THE DAY.
WHILE EXACT TIMING IS QUESTIONABLE...WEAK UPPER DISTURBANCE AND
ANOTHER LOW-LEVEL JET MAX APPROACHING THE UPPER MIDWEST WILL BRING
INCREASING CHANCES FOR THUNDERSTORMS. BEST CHANCES STAY WEST OF
KMSN UNTIL MID-LATE MORNING...THEN SPREAD EAST AND INCREASE THROUGH
THE AFTERNOON. SHOWERS AND STORMS MOST LIKELY FROM LATE AFTERNOON
THROUGH THE EVENING BRINGING MVFR CIGS/VSBYS...POSSIBLY DROPPING
TO IFR WITH HEAVY DOWNPOURS OF RAIN. WILL THEN KEEP MVFR
CONDITIONS THROUGH THE REMAINDER OF THE FORECAST.
MARINE...
SOUTH WINDS WILL INCREASE RAPIDLY AFTER SUNRISE...WITH
GUSTS TO 20 KNOTS BY MID TO LATE MORNING. PREVAILING WINDS HOLD JUST
BELOW SMALL CRAFT CRITERIA...THOUGH THERE WILL BE A FEW GUSTS TO
25 KNOTS. HAVE ADDED A CAUTIONARY STATEMENT FOR SMALL CRAFT IN THE
NEARSHORE FORECAST AND IN THE HAZARDOUS WEATHER OUTLOOK FOR TODAY.
EXPECT THUNDERSTORM CHANCES TO INCREASE THROUGH THE LATE MORNING
AND AFTERNOON...BECOMING MOST LIKELY THIS EVENING. WHILE THE STORMS
ARE EXPECTED TO STAY BELOW SEVERE LEVELS...GUSTY WINDS...SMALL
HAIL AND VISIBILITY-REDUCING HEAVY RAINS ARE POSSIBLE.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...CRAVEN
TODAY/TONIGHT AND AVIATION/MARINE...MRC
FRIDAY THROUGH WEDNESDAY...HENTZ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1225 PM CDT THU MAY 30 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 333 AM CDT THU MAY 30 2013
CURRENTLY AS OF 0830Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT
ANALYSIS SHOWED UPPER TROUGHING FROM THE NORTHEAST PACIFIC INTO THE
NORTHERN ROCKIES WITH AN UPPER LOW IN NORTHEAST WYOMING...WHILE
DOWNSTREAM RIDGING WAS PRESENT ACROSS THE EASTERN U.S.. ALSO TO NOTE
ON WATER VAPOR IS A FAIRLY POTENT SHORTWAVE OVER THE TEXAS AND
OKLAHOMA PANHANDLES IN THE BASE OF THIS TROUGHING. NEARLY
UNIDIRECTIONAL SOUTH TO SOUTHWEST FLOW EXISTED BETWEEN THE TROUGHING
AND RIDGING... WITH SOME VERY STRONG WINDS AT 850MB. VWP AND
PROFILER DATA SHOWED SPEEDS OF 50-65 KT FROM CENTRAL OKLAHOMA INTO
SOUTHERN MINNESOTA. THESE WINDS WERE TRANSPORTING COPIOUS AMOUNTS OF
MOISTURE NORTHWARD...NOTED BY PRECIPITABLE WATER VALUES OF 1.5-1.75
INCHES OR 150-180 PERCENT OF NORMAL. NUMEROUS SHORTWAVES...SOME
CONVECTIVELY INDUCED...RIDING THROUGH THE MID LEVEL FLOW HAS BEEN
INTERACTING WITH THE MORE SUMMER-LIKE AIRMASS TO CONTINUE TO PRODUCE
SCATTERED CLUSTERS OF SHOWERS AND THUNDERSTORMS. MUCH OF THE
FORECAST AREA LIES IN THE WARM SECTOR OF A LOW PRESSURE SYSTEM BACK
IN THE DAKOTAS. MAIN WARM FRONT HAS LIFTED INTO NORTHERN WISCONSIN
WHILE THE COLD FRONT IS WELL BACK TO THE WEST IN CENTRAL SOUTH
DAKOTA.
MODELS ARE IN GOOD AGREEMENT ON THE SYNOPTICS THROUGH TONIGHT...
INDICATING THAT THE UPPER TROUGHING FROM WYOMING INTO THE TEXAS
PANHANDLE WILL SHIFT EAST NORTHEAST INTO THE FORECAST AREA BY 06Z
TONIGHT. THERE ARE SOME DECENT 500MB HEIGHT FALLS BETWEEN 18Z-06Z
OVER THE FORECAST AREA...ON THE ORDER OF 60-90 METERS. THE DPVA FROM
THE APPROACH OF THIS UPPER TROUGH...AS WELL AS VARIOUS SHORTWAVES
AND CONVECTIVELY INDUCED SHORTWAVES AHEAD OF IT...SUGGESTS PLENTY OF
FORCING FOR CONVECTION. MODELS HAVE SHOWN THIS FOR MANY DAYS AS
WELL. THIS FORCING MAY MAKE IT HARD TO BUILD A LOT OF INSTABILITY...
COMPARED TO YESTERDAY WHERE WE HAD PLENTY OF SUNSHINE BEFORE
CONVECTION ERUPTED. RAP/NAM/GFS SOUNDINGS ALL SUGGEST ANY 0-1 MLCIN
FROM NOCTURNAL INFLUENCES BEING NEARLY COMPLETELY GONE BY 15Z.
THEREFORE IT IS CONCEIVABLE FOR CONVECTION TO FIRE SHORTLY
THEREAFTER WHEN 0-1 MLCAPE IS ONLY AT 800-1500 J/KG. HRRR/RAP MODELS
SHOW CONVECTION FIRING IN THAT 15-16Z WINDOW...IN AGREEMENT WITH THE
ABOVE ANALYSIS. THE CONVECTION MAY STABILIZE THINGS BRIEFLY...BUT
PERSISTENT HEATING THROUGH THE DAY COMBINED WITH SOUTHERLY WARM
ADVECTION OF INSTABILITY SHOULD PROVIDE FUEL TO CONTINUE PERIODS OF
CONVECTION THROUGH THE DAY AND INTO THE EVENING. PASSAGE OF THE
UPPER TROUGH AND NOCTURNAL COOLING SHOULD ALLOW CONVECTION TO
SUBSIDE AFTER MIDNIGHT.
REGARDING SEVERE POTENTIAL...THE LIMITATION OF BUILDING A LOT OF
CAPE IS A HINDRANCE. 0-6KM SHEAR FROM THE 30.00Z NAM/GFS IS
GENERALLY PROGGED AT 25-30 KT THROUGH THE DAY...FAVORING FOR MORE OF
A MULTI-CELL SITUATION. WITH INSTABILITY STRUGGLING...NOT THINKING
MUCH IN THE WAY FOR SEVERE HAIL. BULK OF THE AFOREMENTIONED 0-6KM
SHEAR IS IN THE 0-3KM LAYER...AND COMBINED WITH 850MB WINDS PROGGED
IN THE AFTERNOON AND EVENING OF 45-50 KT DOES BRING UP A CONCERN FOR
THE STORMS TO PRODUCE STRONG TO DAMAGING WIND GUSTS. 0-1KM SHEAR IS
QUITE HIGH AS WELL FOR THE AFTERNOON AND EVENING...SIMILAR TO 0-3KM
OF 25-30KT...SO WE MAY WANT TO WATCH FOR POSSIBLE TORNADOES TOO.
THIS WOULD BE ESPECIALLY TRUE ALONG ANY CONVECTIVE OUTFLOW BOUNDARY
AND/OR IF WE CAN GET MORE DAYTIME HEATING THAN EXPECTED.
ON THE FLOODING FRONT...MORE INFORMATION CAN BE FOUND IN THE
HYDROLOGY SECTION BELOW. BRIEFLY...THE PATTERN TODAY INTO THIS
EVENING IS VERY FAVORABLE FOR STORMS TO TRAIN ACROSS THE SAME AREAS
AS THEY MARCH SOUTH TO NORTH. WITH PRECIPITABLE WATER VALUES STAYING
UP IN THE 1.5-1.75 INCH RANGE ANY STORM CAN PRODUCE HEAVY RAIN. WITH
GROUNDS ALREADY SATURATED...FLASH FLOODING IS CERTAINLY POSSIBLE...
ESPECIALLY SOUTH OF I-90 WHICH WAS REALLY IMPACTED FROM YESTERDAY
INTO LAST NIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 333 AM CDT THU MAY 30 2013
LOW PRESSURE OVER THE EASTERN DAKOTAS PUSHES SOUTHEAST LATE FRIDAY
MORNING INTO FRIDAY AFTERNOON DRIVING THE FRONT ACROSS THE FORECAST
AREA. DEPENDING ON THE TIMING OF THIS FRONT...SEVERE WEATHER POSSIBLE
ON FRIDAY. FORECAST MODELS ARE IN REASONABLE AGREEMENT...SHOWING
0-3 KM MUCAPE VALUES CLIMBING TO 2000 TO 3000 J/KG. SHEAR IS ALSO
RAMPING UP LATE FRIDAY MORNING INTO FRIDAY AFTERNOON WITH 0-6 KM
BULK SHEAR INCREASING TO 45 TO 55 KTS. THE HIGHEST INSTABILITY
APPEARS TO BE OVER FAR NORTHEAST IOWA AND INTO EXTREME SOUTHWEST
WISCONSIN. WILL HAVE TO KEEP A VERY CLOSE WATCH ON THIS OVER THE
NEXT FEW MODEL RUNS. AT THIS TIME...LARGE HAIL AND DAMAGING WINDS
APPEAR TO BE THE MAIN HAZARDS FROM THESE STORMS. BUT AGAIN...THE
SEVERE THREAT AREA WILL DEPEND ON WHERE THE BOUNDARY IS LOCATED
LATE FRIDAY MORNING INTO FRIDAY AFTERNOON AND HOW MUCH SURFACE
HEATING IS REALIZED. A DRY SLOT PUSHES INTO THE FORECAST AREA LATE
FRIDAY NIGHT AS THE LOW PUSHES EAST INTO THE WESTERN GREAT LAKES.
THERE SHOULD BE A DRY PERIOD AS THE LOW MOVES IN...BUT THEN
SHOWERS AND ISOLATED THUNDERSTORMS WILL DEVELOP ON SATURDAY AS THE
LOW SLIDES ACROSS THE REGION. AN UNSEASONABLY COOL AIRMASS MOVES
INTO REGION ON SUNDAY. 850 MB TEMPERATURES FALL TO 0 C OVER
NORTHERN WISCONSIN AND TO AROUND 2 C OVER NORTHEAST IOWA. THIS
WILL SET THE STAGE FOR A CHILLY NIGHT ACROSS THE AREA SUNDAY NIGHT
INTO EARLY MONDAY MORNING. ECMWF 850 MB TEMPERATURE STANDARDIZED
ANOMALIES FALL TO AROUND -1.5...INDICATIVE OF AN ANOMALOUSLY COLD
AIRMASS. TEMPERATURES WILL PLUMMET INTO THE UPPER 30S OVER FAR
NORTHERN WISCONSIN. WILL HAVE TO KEEP A VERY CLOSE WATCH ON LOWS OVER
NORTH CENTRAL AND CENTRAL WISCONSIN WHERE TYPICAL COLD SPOTS SUCH
AS SPARTA AND BLACK RIVER FALLS COULD SEE LOWS DIP INTO THE UPPER
30S...LEADING TO FROST FORMATION. COOL HIGH PRESSURE REMAINS OVER
THE REGION THROUGH TUESDAY...WITH HIGHS ONLY IN THE 60S. HIGH
PRESSURE PUSHES EAST OF THE REGION LATE TUESDAY INTO WEDNESDAY AS
A TROUGH DIGS INTO THE DAKOTAS. SOUTHERLY FLOW DEVELOPS OVER THE
AREA HELPING TO USHER IN WARMER TEMPERATURES. THE TROUGH WILL MOVE
INTO THE FORECAST AREA LATE TUESDAY NIGHT THROUGH WEDNESDAY
BRINGING CHANCES FOR SHOWERS AND THUNDERSTORMS TO THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1225 PM CDT THU MAY 30 2013
FORECAST THIS PERIOD REMAINS DIFFICULT...ESPECIALLY THIS AFTERNOON
AND EVENING. ANOTHER ROUND OF MORE WIDESPREAD SHRA/TSRA EXPECTED TO
SPREAD ACROSS THE TAF SITES THIS AFTERNOON/EVENING WITH PERIOD OF
MVFR CIGS AND IFR/MVFR VSBYS IN STRONGER STORM CORES. GENERALLY LEFT
TSRA MENTION IN TAFS FOR THIS AFTERNOON AS VCTS AND CB DUE TO
UNCERTAINTIES OF THE TIMING AND TSRA PASSING OVER A TAF SITE. PLAN
ON TAF UPDATES AS CONVECTION MODE/TIMING BECOME CLEARER THRU THE
AFTERNOON.
TIGHT PRESSURE GRADIENT REMAINS OVER THE AREA THIS AFTERNOON FOR
SOUTH WINDS 15-20KT G25-30KTS. GRADIENT RELAXES A BIT TONIGHT BUT
WIND LOOK TO REMAIN SOUTH 10-15KTS...FOR GOOD BOUNDARY LAYER
STIRRING/MIXING TO LIMIT BR FORMATION. ONCE THE MID LEVEL TROUGH
AXIS PASSES TONIGHT...SFC TO MID LEVEL FLOW SWINGS A BIT MORE
SOUTHWEST...BRINGING SOME SLIGHTLY DRIER AIR INTO THE AREA.
GENERALLY SCT030 CLOUDS EXPECTED LATER TONIGHT/FRI MORNING BEHIND
THIS PASSING FEATURE.
&&
.HYDROLOGY...TODAY AND TONIGHT
ISSUED AT 333 AM CDT THU MAY 30 2013
HEAVY RAIN FELL ACROSS THE AREA WEDNESDAY AFTERNOON AND EVENING
WITH RAINFALL AMOUNTS OF 2 TO 3 INCHES REPORTED ACROSS PORTIONS OF
NORTHEAST IOWA...SOUTHEAST MINNESOTA AND SOUTHWEST
WISCONSIN...WITH LOCALLY HIGHER AMOUNTS OF 4 INCHES REPORTED. AN
ADDITIONAL 1 TO 2 INCHES OF RAIN IS EXPECTED ACROSS THE AREA
TODAY THROUGH THIS EVENING...WHICH COULD LEAD TO FLASH FLOODING.
IT WILL NOT TAKE MUCH RAIN OVER THE SATURATED SOILS TO CREATE
FLOODING ISSUES. ALSO...AREA RIVERS WILL SEE RISES AND POSSIBLE
FLOODING WITH ANY ADDITIONAL RAINFALL RECEIVED. HAVE EXPANDED THE
FLASH FLOOD WATCH NORTHWARD...INCLUDING AREAS ALONG AND SOUTHWEST
OF INTERSTATE 94 CORRIDOR EXCLUDING JUNEAU COUNTY
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR WIZ032>034-041-042-
053>055-061.
MN...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR MNZ079-086>088-
094>096.
IA...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR IAZ008>011-018-019-
029-030.
&&
$$
SHORT TERM...AJ/WETENKAMP
LONG TERM....WETENKAMP
AVIATION.....RRS
HYDROLOGY....WETENKAMP