Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 06/26/13
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1038 PM MDT SUN JUN 23 2013
.UPDATE...
ISSUED AT 447 PM MDT SUN JUN 23 2013
UPDATED TO ISSUE A SEVERE THUNDERSTORM WATCH FOR AREAS EAST OF A
LINE FROM COLORADO SPRINGS TO SPRINGFIELD. THIS WATCH GOES THROUGH
MIDNIGHT. THE MAIN THREATS WILL BE LIGHTNING...DAMAGING OUTFLOW
WIND GUSTS AND HAIL TO ONE INCH IN DIAMETER. MOZLEY
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 227 PM MDT SUN JUN 23 2013
...CONTINUED DANGEROUS FIRE WEATHER CONDITIONS...
CURRENTLY...SMOKE FROM THE WEST FORK COMPLEX IS STARTING TO SHIFT
EAST ACROSS THE SAN LUIS VALLEY AND SHOULD CONTINUE TO PUSH EAST
THROUGH THE EVENING. RADAR HAS BEEN PRETTY QUIET WITH A FEW CELLS
BUBBLING NEAR THE SPANISH PEAKS/WALSENBURG AREA. SOUTHEASTERLY
SURFACE FLOW HAS KEPT MOISTURE IN PLACE ACROSS THE PLAINS WITH DEW
POINTS IN THE 40S TO MID 50S. TEMPERATURES ARE WARM WITH UPPER 80S
TO LOWER 90S FOR THE LOWER ELEVATIONS.
TONIGHT...MAIN CONCERN FOR THIS EVENING WILL BE THE POTENTIAL FOR
SEVERE THUNDERSTORMS ACROSS THE PLAINS. CUMULUS HAVE BEEN
PERCOLATING ACROSS THE RAMPART RANGE AND EASTERN MOUNTAINS THIS
AFTERNOON AND AS AN UPPER LEVEL DISTURBANCE MOVES THROUGH THE
SOUTHWEST FLOW ALOFT...IT WILL LIKELY TRIGGER ISOLATED
THUNDERSTORMS. FOLLOWED A BLEND OF THE WRF SOLUTIONS AND HRRR WHICH
DEVELOP SPOTTY CONVECTION FROM COLORADO SPRINGS...SOUTHEAST TO
SPRINGFIELD AND TRACK THEM EAST ACROSS THE PLAINS THROUGH 05Z.
UPDRAFT HELICITY VALUES ARE WEAK BASED ON THE NSSL WRF SOLUTION AND
SHEARS ARE ONLY RUNNING AROUND 30 KTS SO CURRENTLY THINKING THE MAIN
THREATS WILL BE HAIL TO ONE INCH IN DIAMETER AND STRONG THUNDERSTORM
OUTFLOW WINDS. THE TORNADO THREAT LOOKS TO REMAIN NORTH IN
NORTHEAST COLORADO. EXPECT ALL ACTIVITY TO SHIFT EAST INTO KANSAS
THROUGH 06Z WITH DRY CONDITIONS THE REST OF THE NIGHT.
MONDAY...AN UPPER TROUGH WILL MOVE OUT OF THE PACIFIC NORTHWEST
WHICH WILL INCREASE SOUTHWESTERLY FLOW ACROSS COLORADO. THIS WILL
SET THE STAGE FOR WIDESPREAD EXTREME FIRE WEATHER CONDITIONS WITH
WINDS GUSTING TO 30 TO 40 MPH...AND HUMIDITY VALUES WELL UNDER 10
PERCENT. EXTREME CAUTION IS ADVISED ACROSS ALL OF SOUTHERN
COLORADO...BUT PARTICULARLY OVER THE MOUNTAIN REGIONS AND AREAS
ALONG AND WEST OF I-25. THE STRONG WINDS SHOULD ALSO ALLOW
TEMPERATURES TO WARM QUICKLY INTO TO THE UPPER 90S TO LOWER 100S
ACROSS THE PLAINS. SMOKE FROM AREA FIRES WILL SPREAD ACROSS MUCH OF
THE AREA BY THE AFTERNOON WITH REDUCED VISIBILITIES AND POOR AIR
QUALITY. MOZLEY
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 227 PM MDT SUN JUN 23 2013
THERE COULD BE A FEW SHOWERS/TSTMS ALONG THE ERN BORDER EARLY MON
EVENING...BUT WL LEAVE THE FORECAST DRY OUT THERE FOR NOW. DRY
WESTERLY FLOW IS EXPECTED OVR THE FORECAST AREA ON TUE. IT LOOKS
LIKE LOW LEVEL MSTR OVR THE ERN SAN JUAN AND LA GARITA MTNS MAY BE
A LITTLE HIGHER ON TUE...KEEPING MIN RH VALUES HIGH ENOUGH THAT A
FIRE WX HIGHLIGHT SHOULD NOT BE NEEDED FOR THAT AREA. HOWEVER
THERE IS A CHANCE THAT THE WINDS WL BE STRONG ENOUGH...ALONG WITH
DRY ENOUGH HUMIDITIES OVER THE SAN LUIS VALLEY (FIRE ZONE 224) AND
ALONG THE SANGRE DE CRISTO MTNS (FIRE ZONE 225)...TO WARRANT A FIRE
WEATHER WATCH. THE REST OF THE AREA SHOULD NOT HAVE STRONG ENOUGH
WINDS TO WARRANT A FIRE HIGHLIGHT.
FOR WED AN UPR RIDGE CENTER IS EXPECTED TO BE OVR THE WEST CENTRAL
NM...WITH THE FLOW ALOFT OVR THE FORECAST AREA BECOMING MORE
NORTHWESTERLY. STILL LOOKS DRY ACRS THE AREA...WITH MAYBE JUST A
COUPLE SHOWERS/TSTMS POPPING UP OVR SOME MTN LOCATIONS. THE UPR
RIDGE THEN REMAINS OVR THE AREA THU THRU SAT WITH MODELS
INDICATING SOME MSTR TRAPPED UNDER THE RIDGE AND THE POTENTIAL FOR
JUST A FEW SHOWERS/TSTMS OVR AND NR THE MTNS. THE GFS SHOWS THE
POTENTIAL FOR A WEATHER SYSTEM MOVING BY TO THE NORTH SAT
NIGHT/SUN FLATTENING THE RIDGE AND SENDING A FRONT INTO THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1031 PM MDT SUN JUN 23 2013
THE MAIN AVN CONCERN TOMORROW WILL BE INCREASED SOUTHWEST
WINDS OVER THE AREA FROM LATE MORNING THROUGH EARLY EVENING.
WINDS COULD GUST IN THE 30-40 MPH RANGE BY LATE AFTERNOON...
PARTICULARLY AT KALS AND KCOS. THE SOUTHWEST WINDS ALOFT
WILL ALSO LEAD TO INCREASED SMOKE AT ALL TERMINALS IN THE
AFTERNOON AND EVENING. DEPENDING ON HOW ACTIVE THE WEST FORK
FIRE COMPLEX GETS...VISIBILITY MAY DROP TO MVFR OR LOWER
AGAIN BY EARLY EVENING. ROSE
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 11 AM TO 8 PM MDT MONDAY FOR COZ220>230.
FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING
FOR COZ224-225.
&&
$$
UPDATE...MOZLEY
SHORT TERM...MOZLEY
LONG TERM...28
AVIATION...ROSE
AREA FORECAST DISCUSSION
NWS ALBANY NY
450 PM EDT MON JUN 24 2013
.SYNOPSIS...
VERY WARM AND HUMID CONDITIONS WILL CONTINUE EARLY THIS WEEK WITH
THE THREAT OF SHOWERS AND THUNDERSTORMS MAINLY DURING THE AFTERNOON
AND EVENING HOURS. STORMS WILL HAVE THE POTENTIAL TO PRODUCE LOCALLY
HEAVY RAINFALL. OUR NIGHTS WILL BE CONTINUE TO BE MUGGY WITH PATCHY
FOG. MORE PERSISTENT CHANCES FOR SHOWERS AND THUNDERSTORMS ARE
EXPECTED LATER IN THE WEEK INTO THE WEEKEND AS A SLOW MOVING LOW
PRESSURE SYSTEM IMPACTS THE REGION.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 955 AM...ANOTHER HAZY...HOT AND HUMID DAY SHAPING UP. 12Z ALY
SOUNDING SHOWS PLENTY OF ENERGY FOR AFTERNOON THUNDERSTORMS. WATER
VAPOR LOOP SHOWS CLOSED LOW SPINNING OVER WESTERN PENNSYLVANIA.
THIS UPPER LEVEL LOW IS EXPECTED TO MOVE OVER THE SOUTHERN PART OF
THE ALBANY FORECAST AREA OVER THE NEXT 12-18 HOURS AND SHOULD BE A
FOCUS FOR STORMS. PWAT ON 12Z ALY SOUNDING WAS 1.77 INCHES SO
COPIOUS MOISTURE FOR HEAVY RAINERS. PIT 12Z SOUNDING...UNDER UPPER
LEVEL LOW...HAS STEEPER LAPSE RATES. 12Z HRRR SHOWING A MORE
WIDESPREAD THREAT OF AFTERNOON STORMS. WILL HAVE TO MONITOR FOR
LATER FLASH FLOOD WATCH IF LARGE AREA OF HEAVY RAIN DEVELOPS.
COULD BE AN EXCITING DAY...
PREVIOUS...
THE RIDGE WILL WEAKEN A TAD TODAY AS THE REMNANTS OF THE UPPER
LOW FROM OVER THE TENNESSEE VALLEY MOVES EASTWARD. THIS WILL BE
THE MAIN FEATURE TRIGGERING CONVECTION ACROSS THE AREA TODAY AND
IT WILL ACCOMPANY THE HEATING OF THE DAY. MODEL GUIDANCE SUGGESTS
CAPE VALUES OF PEAKING AT 1000-2000 J/KG WITH DEW POINTS IN THE
MID TO UPPER 60S. LAPSE RATE OF 6 TO 6.5 C/KM ARE EXPECTED THIS
AFTERNOON WITH THE GFS INDICATING 7 C/KM POSSIBLE. MEAN FLOW IS
RATHER WEAK AT 15 TO 20 KNOTS SO STORMS WILL MOVE RATHER SLOWLY
AND CONVECTION WILL BE LOOSELY ORGANIZED. THE STORM PREDICTION
CENTER HAS THE AREA/REGION IN THE GENERAL THUNDERSTORM OUTLOOK FOR
TODAY AND TONIGHT. FREEZING LEVEL IS HIGH JUST OVER 14000 FEET ON
THE 00Z/MON ALY SOUNDING...SO SOME STORMS WILL PRODUCE LOCALLY
HEAVY RAINFALL. THIS ALONG WITH THE RATHER SLOW MOVEMENT HAVE
ADDED ENHANCED WORDING OF HEAVY RAINFALL TO THE FORECAST AND WILL
KEEP MENTION IN THE HAZARDOUS WEATHER OUTLOOK. CONVECTION IS
EXPECTED TO DIMINISH THIS EVENING AS THE WEAKENING UPPER
LOW/TROUGH MOVES OFF TO THE EAST AND WITH THE LOSS OF DAYTIME
HEATING.
LOOKING AT TEMPERATURES IN THE 80S WITH AROUND 90 DEGREES UP THE
HUDSON VALLEY INTO CAPITAL DISTRICT. DEW POINTS WILL BE IN THE MID
TO UPPER 60S MAKING IT FELL EVEN HOTTER. HEAT INDICES SHOULD REACH
THE MID 90S UP THE HUDSON RIVER VALLEY.
ANOTHER MUGGY NIGHT WITH LOWS AND DEW POINTS IN THE 60S. WINDS WILL
BECOME LIGHT TO CALM WINDS. HAVE ADDED PATCHY FOG MAINLY IN THE
RIVER VALLEY LOCATIONS.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
BY TUESDAY MORNING FLOW WILL BECOME NEARLY ZONAL ACROSS THE REGION.
A WEAKENING SURFACE LOW AND MID LEVEL SHORT WAVE TROUGH WILL MOVE
EASTWARD ACROSS SOUTHERN CANADA PASSING WELL TO OUR NORTH TUESDAY.
PLUS GUIDANCE INDICATES SMALL PIECES OF ENERGY SHOULD MOVE THROUGH
THE FLOW FARTHER SOUTH ACROSS OUR REGION.ALL THIS LEADS TO ANOTHER
ROUND OF CONVECTION MAINLY DURING THE AFTERNOON AND EVENING HOURS
TUESDAY WITH THE HEATING OF THE DAY. THE BETTER DYNAMICS AND SHEAR
WILL BE ACROSS NORTHERN NEW YORK INTO NORTHERN NEW ENGLAND AND THIS
IS WHERE THE STORM PREDICTION CENTER HAS GONE WITH A SLIGHT RISK FOR
SEVERE THUNDERSTORMS. FARTHER SOUTH ACROSS OUR FORECAST AREA MEAN
FLOW WILL STILL BE RATHER WEAK AROUND 20 KNOTS. IT WILL BE ANOTHER
HOT DAY SIMILAR TO MONDAY IN TEMPERATURES AND HEAT INDICES.
A WEAK FRONTAL BOUNDARY WILL BE BROUGHT SOUTHWARD INTO THE REGION
TUESDAY NIGHT...HOWEVER DUE TO THE FLOW ALOFT THE BOUNDARY WILL
STALL ACROSS THE REGION. A MORE VIGOROUS SHORT WAVE WILL MOVE INTO
THE LONGWAVE TROUGH OVER THE GREAT LAKES REGION WEDNESDAY AND
WEDNESDAY NIGHT AND HEIGHTS WILL BEGIN TO FALL. CHANCES FOR
CONVECTION WILL NOT BE LIMITED MAINLY TO THE AFTERNOON AND EVENING
HOURS THIS TIME. AS HEIGHTS CONTINUE TO FALL WILL HAVE LARGE SCALE
ASCENT THE BOUNDARY WILL BEGIN TO MOVE BACK NORTHWARD AS A WARM
FRONT.
PRECIPITABLE WATER VALUES WILL STILL BE HIGH SO LOCALLY HEAVY
RAINFALL IS EXPECTED WITH SOME STORMS...SO HAVE MENTIONED IN OUR
HAZARDOUS WEATHER OUTLOOK.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AN UNSETTLED AND WET EXTENDED FORECAST IS LIKELY ACROSS NY AND NEW
ENGLAND WITH PERSISTENT CHANCES OF SHOWERS AND THUNDERSTORMS...AS A
MID AND UPPER LEVEL TROUGH WILL INITIALLY IMPACT THE REGION TO CLOSE
THE WEEK...AND THEN IT MAY CLOSE OR CUT OFF NEAR THE GREAT LAKES
REGION AND SRN ONTARIO FOR THE WEEKEND.
THE LATEST GFS/ECMWF/CANADIAN GGEM/ENSEMBLE GUIDANCE AND HPC
GRAPHICS ARE IN PRETTY GOOD AGREEMENT FOR AN ACTIVE STRETCH OF
WEATHER. THEIR ARE SOME SUBTLE DIFFERENCES FOR THE TIMING OF THE
SHORT-WAVE IMPULSE ROTATING THROUGH THE UPPER LEVEL TROUGH...BUT ALL
AN ALL...IT IS EXTREMELY DIFFICULT TO FIND A SUSTAINED DRY STRETCH
OF WX TO CLOSE JUNE.
THU-FRI...A WAVE OF LOW PRESSURE APPROACHES THE FCST AREA FROM THE
GREAT LAKES REGION WITH SOME OVER RUNNING SHOWERS AND THUNDERSTORMS
AHEAD OF A WARM FRONT. THE WARM FRONT MAY BUST THROUGH PORTIONS OF
THE FCST AREA FOR A POTENTIAL OF STRONG THUNDERSTORMS...IF HEATING
IS REALIZED. THE DETAILS ARE NEBULOUS AND MURKY...SO WE WILL CALL
IT A CHANCE OF SHOWERS AND THUNDERSTORMS...THU INTO THU NIGHT. A
S/SW H850 LLJ OF 30-45 KTS WILL TRANSPORT IN SOME GULF
MOISTURE...AND PWATS WILL CONTINUE TO RUN ABOVE NORMAL. THE SFC LOW
BEGINS TO OCCLUDE AND CLOSE OFF JUST NORTHWEST OF LAKE ONTARIO AND
NRN NY ON FRI. THE GFS CONTINUES TO PAINT MODERATE AMOUNTS OF
INSTABILITY FOR THE POTENTIAL OF SHOWERS AND THUNDERSTORMS AGAIN.
THE SUBTROPICAL HIGH REMAINS ANCHORED DOWNSTREAM CONTINUING A DEEP
S/SW FETCH OF MOISTURE. THIS LONG DURATION STRETCH OF WX...BEGINS
TO MATERIALIZE INTO POTENTIALLY A CLASSIC GREAT LAKES CSTAR CUTOFF
LOW WARM SEASON EVENT. TEMPS LOOK TO RUN SLIGHTLY BELOW TO NEAR
NORMAL FOR THE THESE DAYS WITH HIGHS IN THE M70S TO L80S AND LOWS IN
THE U50S TO 60S.
SAT-MON...THE LONGWAVE TROUGH BEGINS TO AMPLIFY WITH THE EMBEDDED
500 HPA CLOSED CIRCULATIONS OVER THE CNTRL AND ERN GREAT LAKES. A
COLD FRONT BEGINS TO STALL OUT NEAR THE ERN CONUS SEABOARD.
MULTIPLE SHORT-WAVES LIFT NORTHWARD ON THE EAST SIDE OF TROUGH.
PERSISTENT BANDS OF SHOWERS AND THUNDERSTORMS TIMED TO THE DIURNAL
HEATING AND THE PROPAGATION OF THE IMPULSES ARE POSSIBLE FOR THE
WEEKEND INTO EARLY NEXT WEEK. THEIR IS A SMALL POSSIBILITY THAT
DRYING IN THE WAKE OF DISTURBANCES MAY PROMOTE MINI DRY STRETCHES.
AGAIN...THIS APPEARS TO FIT A GREAT LAKES WARM SEASON CSTAR
CLOSED/CUTOFF SCENARIO FOR AN EXTENDED PERIOD OF SHOWERS AND
THUNDERSTORMS. THE WEEKEND IS DOMINATED BY A POSITIVE TILT
SCENARIO...PERHAPS SHIFTING NEUTRAL BY EARLY NEXT WEEK. H850 TEMPS
CONTINUE TO BE IN THE +14C TO +16C RANGE WITH LIMITED HEATING EACH
DAY WITH A RESIDUAL COLD POOL ALOFT...AND THE ACTIVE S/SW FLOW.
EXPECT HIGHS TO CONTINUE IN THE 70S TO L80S WITH LOWS IN THE U50S TO
60S. TOO EARLY TO PINPOINT LOCATIONS...BUT SOME HYDRO PROBLEMS COULD
MATERIALIZE...IF LOCATIONS GET REPEATEDLY HIT BY BANDS OF SHOWERS
AND THUNDERSTORMS.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
AS OF 445 PM EDT...MOST OF THE THUNDERSTORMS HAVE STAYED AWAY FROM
THE TAF SITES. ONCE BRUSHED KALB/KGFL...ONE IS JUST NORTH OF KPOU.
IT LOOKS AS IF ONE CELL MIGHT HIT KPSF SO AMENDED TO INCLUDE A TEMPO
FOR MVFR THUNDER 21-22Z.
STILL MORE THUNDERSTORMS UPSTREAM ALTHOUGH OVERALL THE TREND HAS
WEAKENED SLIGHTLY BUT STILL PLENTY OF INSTABILITY TO WORK WITH...NOT
OUT OF THE WOODS YET. EXCEPT FOR KPSF WILL CONTINUE WITH GENERAL
VCSH BUT THAT COULD CHANGE AT ANY TIME THROUGH 00Z. STAY TUNED AND
KEEP CHECKING THE TAFS AND AVIATION DISCUSSION.
AFTER WE LOOSE THE CELLS THIS EVENING...CONCERNS FOCUS TO FOG
ISSUES...ESPECIALLY AT KGFL WHERE BELIEVE IT WILL HAPPEN. ELSEWHERE
WENT WITH MVFR FOG.
THE WINDS TODAY WILL BE FROM A WESTERLY DIRECTION AT 5-10 KNOTS
WITH OCCASIONAL GUST TO 15 KNOTS. EXPECT THE WINDS TO BECOME LIGHT TO
CALM IN THE EARLY EVENING AND REMAIN LIGHT THROUGH TUESDAY.
OUTLOOK...
TUE...MAINLY VFR. CHC -TSRA/-SHRA MAINLY DURING THE AFTN INTO THE
EVNG. MVFR-IFR FOG LATE AT NIGHT INTO EARLY IN THE MORNING.
WED...MAINLY VFR. SLIGHT CHC -TSRA/-SHRA.
THU-FRI...VFR/MVFR. CHC -TSRAS/-SHRAS.
&&
.FIRE WEATHER...
VERY WARM AND HUMID CONDITIONS WILL CONTINUE EARLY THIS WEEK WITH
THE THREAT OF SHOWERS AND THUNDERSTORMS MAINLY DURING THE AFTERNOON
AND EVENING HOURS. STORMS WILL HAVE THE POTENTIAL TO PRODUCE LOCALLY
HEAVY RAINFALL. OUR NIGHTS WILL BE CONTINUE TO BE MUGGY WITH PATCHY
FOG. MORE PERSISTENT CHANCES FOR SHOWERS AND THUNDERSTORMS ARE
EXPECTED LATER IN THE WEEK INTO THE WEEKEND AS A SLOW MOVING LOW
PRESSURE SYSTEM IMPACTS THE REGION.
&&
.HYDROLOGY...
INCREASING UNSETTLED WEATHER THIS WEEK. EARLY IN THE WEEK THE
CHANCES OF SHOWERS AND THUNDERSTORMS WILL BE MAINLY DURING THE
AFTERNOON AND EVENING HOURS. HOWEVER...PERSISTENT CHANCES OF SHOWERS
AND THUNDERSTORMS ARE EXPECTED FOR THE LATER PART OF THE WEEK INTO
THE WEEKEND AS A MID/UPPER LEVEL TROUGH IMPACTS THE REGION.
STORMS WILL HAVE THE POTENTIAL TO PRODUCE LOCALLY HEAVY RAINFALL ALL
WEEK WITH HIGH PRECIPITABLE WATER VALUES. EARLY IN THE WEEK FLOW
ALOFT WILL BE RATHER LIGHT SO STORMS WILL BE SLOWER MOVERS. FLOW IS
EXPECTED TO INCREASE LATER IN THE WEEK. PONDING OF WATER ON ROADWAYS
ALONG WITH MINOR FLOODING OF LOW LYING AND POOR DRAINAGE AREAS WILL
BE POSSIBLE. PLUS SOME SMALL STREAMS...CREEKS...AND BROOKS MAY REACH
BANKFULL OR EVEN FLOODING QUICKLY IN THE HEAVY RAINFALL ASSOCIATED
WITH THE THUNDERSTORMS ESPECIALLY IF STORMS MOVE OVER THE SAME AREA
REPEATEDLY.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...BGM
NEAR TERM...BGM
SHORT TERM...BGM
LONG TERM...BGM
AVIATION...SND/HWJIV
FIRE WEATHER...BGM
HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
148 PM EDT MON JUN 24 2013
.SYNOPSIS...
VERY WARM AND HUMID CONDITIONS WILL CONTINUE EARLY THIS WEEK WITH
THE THREAT OF SHOWERS AND THUNDERSTORMS MAINLY DURING THE AFTERNOON
AND EVENING HOURS. STORMS WILL HAVE THE POTENTIAL TO PRODUCE LOCALLY
HEAVY RAINFALL. OUR NIGHTS WILL BE CONTINUE TO BE MUGGY WITH PATCHY
FOG. MORE PERSISTENT CHANCES FOR SHOWERS AND THUNDERSTORMS ARE
EXPECTED LATER IN THE WEEK INTO THE WEEKEND AS A SLOW MOVING LOW
PRESSURE SYSTEM IMPACTS THE REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 955 AM...ANOTHER HAZY...HOT AND HUMID DAY SHAPING UP. 12Z ALY
SOUNDING SHOWS PLENTY OF ENERGY FOR AFTERNOON THUNDERSTORMS. WATER
VAPOR LOOP SHOWS CLOSED LOW SPINNING OVER WESTERN PENNSYLVANIA.
THIS UPPER LEVEL LOW IS EXPECTED TO MOVE OVER THE SOUTHERN PART OF
THE ALBANY FORECAST AREA OVER THE NEXT 12-18 HOURS AND SHOULD BE A
FOCUS FOR STORMS. PWAT ON 12Z ALY SOUNDING WAS 1.77 INCHES SO
COPIOUS MOISTURE FOR HEAVY RAINERS. PIT 12Z SOUNDING...UNDER UPPER
LEVEL LOW...HAS STEEPER LAPSE RATES. 12Z HRRR SHOWING A MORE
WIDESPREAD THREAT OF AFTERNOON STORMS. WILL HAVE TO MONITOR FOR
LATER FLASH FLOOD WATCH IF LARGE AREA OF HEAVY RAIN DEVELOPS.
COULD BE AN EXCITING DAY...
PREVIOUS...
THE RIDGE WILL WEAKEN A TAD TODAY AS THE REMNANTS OF THE UPPER
LOW FROM OVER THE TENNESSEE VALLEY MOVES EASTWARD. THIS WILL BE
THE MAIN FEATURE TRIGGERING CONVECTION ACROSS THE AREA TODAY AND
IT WILL ACCOMPANY THE HEATING OF THE DAY. MODEL GUIDANCE SUGGESTS
CAPE VALUES OF PEAKING AT 1000-2000 J/KG WITH DEW POINTS IN THE
MID TO UPPER 60S. LAPSE RATE OF 6 TO 6.5 C/KM ARE EXPECTED THIS
AFTERNOON WITH THE GFS INDICATING 7 C/KM POSSIBLE. MEAN FLOW IS
RATHER WEAK AT 15 TO 20 KNOTS SO STORMS WILL MOVE RATHER SLOWLY
AND CONVECTION WILL BE LOOSELY ORGANIZED. THE STORM PREDICTION
CENTER HAS THE AREA/REGION IN THE GENERAL THUNDERSTORM OUTLOOK FOR
TODAY AND TONIGHT. FREEZING LEVEL IS HIGH JUST OVER 14000 FEET ON
THE 00Z/MON ALY SOUNDING...SO SOME STORMS WILL PRODUCE LOCALLY
HEAVY RAINFALL. THIS ALONG WITH THE RATHER SLOW MOVEMENT HAVE
ADDED ENHANCED WORDING OF HEAVY RAINFALL TO THE FORECAST AND WILL
KEEP MENTION IN THE HAZARDOUS WEATHER OUTLOOK. CONVECTION IS
EXPECTED TO DIMINISH THIS EVENING AS THE WEAKENING UPPER
LOW/TROUGH MOVES OFF TO THE EAST AND WITH THE LOSS OF DAYTIME
HEATING.
LOOKING AT TEMPERATURES IN THE 80S WITH AROUND 90 DEGREES UP THE
HUDSON VALLEY INTO CAPITAL DISTRICT. DEW POINTS WILL BE IN THE MID
TO UPPER 60S MAKING IT FELL EVEN HOTTER. HEAT INDICES SHOULD REACH
THE MID 90S UP THE HUDSON RIVER VALLEY.
ANOTHER MUGGY NIGHT WITH LOWS AND DEW POINTS IN THE 60S. WINDS WILL
BECOME LIGHT TO CALM WINDS. HAVE ADDED PATCHY FOG MAINLY IN THE
RIVER VALLEY LOCATIONS.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
BY TUESDAY MORNING FLOW WILL BECOME NEARLY ZONAL ACROSS THE REGION.
A WEAKENING SURFACE LOW AND MID LEVEL SHORT WAVE TROUGH WILL MOVE
EASTWARD ACROSS SOUTHERN CANADA PASSING WELL TO OUR NORTH TUESDAY.
PLUS GUIDANCE INDICATES SMALL PIECES OF ENERGY SHOULD MOVE THROUGH
THE FLOW FARTHER SOUTH ACROSS OUR REGION.ALL THIS LEADS TO ANOTHER
ROUND OF CONVECTION MAINLY DURING THE AFTERNOON AND EVENING HOURS
TUESDAY WITH THE HEATING OF THE DAY. THE BETTER DYNAMICS AND SHEAR
WILL BE ACROSS NORTHERN NEW YORK INTO NORTHERN NEW ENGLAND AND THIS
IS WHERE THE STORM PREDICTION CENTER HAS GONE WITH A SLIGHT RISK FOR
SEVERE THUNDERSTORMS. FARTHER SOUTH ACROSS OUR FORECAST AREA MEAN
FLOW WILL STILL BE RATHER WEAK AROUND 20 KNOTS. IT WILL BE ANOTHER
HOT DAY SIMILAR TO MONDAY IN TEMPERATURES AND HEAT INDICES.
A WEAK FRONTAL BOUNDARY WILL BE BROUGHT SOUTHWARD INTO THE REGION
TUESDAY NIGHT...HOWEVER DUE TO THE FLOW ALOFT THE BOUNDARY WILL
STALL ACROSS THE REGION. A MORE VIGOROUS SHORT WAVE WILL MOVE INTO
THE LONGWAVE TROUGH OVER THE GREAT LAKES REGION WEDNESDAY AND
WEDNESDAY NIGHT AND HEIGHTS WILL BEGIN TO FALL. CHANCES FOR
CONVECTION WILL NOT BE LIMITED MAINLY TO THE AFTERNOON AND EVENING
HOURS THIS TIME. AS HEIGHTS CONTINUE TO FALL WILL HAVE LARGE SCALE
ASCENT THE BOUNDARY WILL BEGIN TO MOVE BACK NORTHWARD AS A WARM
FRONT.
PRECIPITABLE WATER VALUES WILL STILL BE HIGH SO LOCALLY HEAVY
RAINFALL IS EXPECTED WITH SOME STORMS...SO HAVE MENTIONED IN OUR
HAZARDOUS WEATHER OUTLOOK.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AN UNSETTLED AND WET EXTENDED FORECAST IS LIKELY ACROSS NY AND NEW
ENGLAND WITH PERSISTENT CHANCES OF SHOWERS AND THUNDERSTORMS...AS A
MID AND UPPER LEVEL TROUGH WILL INITIALLY IMPACT THE REGION TO CLOSE
THE WEEK...AND THEN IT MAY CLOSE OR CUT OFF NEAR THE GREAT LAKES
REGION AND SRN ONTARIO FOR THE WEEKEND.
THE LATEST GFS/ECMWF/CANADIAN GGEM/ENSEMBLE GUIDANCE AND HPC
GRAPHICS ARE IN PRETTY GOOD AGREEMENT FOR AN ACTIVE STRETCH OF
WEATHER. THEIR ARE SOME SUBTLE DIFFERENCES FOR THE TIMING OF THE
SHORT-WAVE IMPULSE ROTATING THROUGH THE UPPER LEVEL TROUGH...BUT ALL
AN ALL...IT IS EXTREMELY DIFFICULT TO FIND A SUSTAINED DRY STRETCH
OF WX TO CLOSE JUNE.
THU-FRI...A WAVE OF LOW PRESSURE APPROACHES THE FCST AREA FROM THE
GREAT LAKES REGION WITH SOME OVER RUNNING SHOWERS AND THUNDERSTORMS
AHEAD OF A WARM FRONT. THE WARM FRONT MAY BUST THROUGH PORTIONS OF
THE FCST AREA FOR A POTENTIAL OF STRONG THUNDERSTORMS...IF HEATING
IS REALIZED. THE DETAILS ARE NEBULOUS AND MURKY...SO WE WILL CALL
IT A CHANCE OF SHOWERS AND THUNDERSTORMS...THU INTO THU NIGHT. A
S/SW H850 LLJ OF 30-45 KTS WILL TRANSPORT IN SOME GULF
MOISTURE...AND PWATS WILL CONTINUE TO RUN ABOVE NORMAL. THE SFC LOW
BEGINS TO OCCLUDE AND CLOSE OFF JUST NORTHWEST OF LAKE ONTARIO AND
NRN NY ON FRI. THE GFS CONTINUES TO PAINT MODERATE AMOUNTS OF
INSTABILITY FOR THE POTENTIAL OF SHOWERS AND THUNDERSTORMS AGAIN.
THE SUBTROPICAL HIGH REMAINS ANCHORED DOWNSTREAM CONTINUING A DEEP
S/SW FETCH OF MOISTURE. THIS LONG DURATION STRETCH OF WX...BEGINS
TO MATERIALIZE INTO POTENTIALLY A CLASSIC GREAT LAKES CSTAR CUTOFF
LOW WARM SEASON EVENT. TEMPS LOOK TO RUN SLIGHTLY BELOW TO NEAR
NORMAL FOR THE THESE DAYS WITH HIGHS IN THE M70S TO L80S AND LOWS IN
THE U50S TO 60S.
SAT-MON...THE LONGWAVE TROUGH BEGINS TO AMPLIFY WITH THE EMBEDDED
500 HPA CLOSED CIRCULATIONS OVER THE CNTRL AND ERN GREAT LAKES. A
COLD FRONT BEGINS TO STALL OUT NEAR THE ERN CONUS SEABOARD.
MULTIPLE SHORT-WAVES LIFT NORTHWARD ON THE EAST SIDE OF TROUGH.
PERSISTENT BANDS OF SHOWERS AND THUNDERSTORMS TIMED TO THE DIURNAL
HEATING AND THE PROPAGATION OF THE IMPULSES ARE POSSIBLE FOR THE
WEEKEND INTO EARLY NEXT WEEK. THEIR IS A SMALL POSSIBILITY THAT
DRYING IN THE WAKE OF DISTURBANCES MAY PROMOTE MINI DRY STRETCHES.
AGAIN...THIS APPEARS TO FIT A GREAT LAKES WARM SEASON CSTAR
CLOSED/CUTOFF SCENARIO FOR AN EXTENDED PERIOD OF SHOWERS AND
THUNDERSTORMS. THE WEEKEND IS DOMINATED BY A POSITIVE TILT
SCENARIO...PERHAPS SHIFTING NEUTRAL BY EARLY NEXT WEEK. H850 TEMPS
CONTINUE TO BE IN THE +14C TO +16C RANGE WITH LIMITED HEATING EACH
DAY WITH A RESIDUAL COLD POOL ALOFT...AND THE ACTIVE S/SW FLOW.
EXPECT HIGHS TO CONTINUE IN THE 70S TO L80S WITH LOWS IN THE U50S TO
60S. TOO EARLY TO PINPOINT LOCATIONS...BUT SOME HYDRO PROBLEMS COULD
MATERIALIZE...IF LOCATIONS GET REPEATEDLY HIT BY BANDS OF SHOWERS
AND THUNDERSTORMS.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
POP UP AFTERNOON THUNDERSTORMS DOT THE RADAR SCOPE. PROBABILITY OF
ANY ONE STORM HITTING A TAF SITE IS STILL LESS THAN 30 PERCENT.
WE`LL CONTINUE TO MONITOR AND SEE IF ANY CLUSTERS OF STORMS
DEVELOP WHICH MAY MOVE TOWARD ANY PARTICULAR TAF SITE.
THE WINDS TODAY WILL BE FROM A WESTERLY DIRECTION AT 5-10 KNOTS
WITH OCCASIONAL GUST TO 15 KNOTS. EXPECT THE WINDS TO BECOME LIGHT TO
CALM IN THE EARLY EVENING AND REMAIN LIGHT THROUGH TUESDAY.
OUTLOOK...
TUE...MAINLY VFR. CHC -TSRA/-SHRA MAINLY DURING THE AFTN INTO THE
EVNG. MVFR-IFR FOG LATE AT NIGHT INTO EARLY IN THE MORNING.
WED...MAINLY VFR. SLIGHT CHC -TSRA/-SHRA.
THU-FRI...VFR/MVFR. CHC -TSRAS/-SHRAS.
&&
.FIRE WEATHER...
VERY WARM AND HUMID CONDITIONS WILL CONTINUE EARLY THIS WEEK WITH
THE THREAT OF SHOWERS AND THUNDERSTORMS MAINLY DURING THE AFTERNOON
AND EVENING HOURS. STORMS WILL HAVE THE POTENTIAL TO PRODUCE LOCALLY
HEAVY RAINFALL. OUR NIGHTS WILL BE CONTINUE TO BE MUGGY WITH PATCHY
FOG. MORE PERSISTENT CHANCES FOR SHOWERS AND THUNDERSTORMS ARE
EXPECTED LATER IN THE WEEK INTO THE WEEKEND AS A SLOW MOVING LOW
PRESSURE SYSTEM IMPACTS THE REGION.
&&
.HYDROLOGY...
INCREASING UNSETTLED WEATHER THIS WEEK. EARLY IN THE WEEK THE CHANCES
OF SHOWERS AND THUNDERSTORMS WILL BE MAINLY DURING THE AFTERNOON AND
EVENING HOURS. HOWEVER...PERSISTENT CHANCES OF SHOWERS AND
THUNDERSTORMS ARE EXPECTED FOR THE LATER PART OF THE WEEK INTO THE
WEEKEND AS A MID/UPPER LEVEL TROUGH IMPACTS THE REGION.
STORMS WILL HAVE THE POTENTIAL TO PRODUCE LOCALLY HEAVY RAINFALL ALL
WEEK WITH HIGH PRECIPITABLE WATER VALUES. EARLY IN THE WEEK FLOW ALOFT
WILL BE RATHER LIGHT SO STORMS WILL BE SLOWER MOVERS. FLOW IS
EXPECTED TO INCREASE LATER IN THE WEEK. PONDING OF WATER ON
ROADWAYS ALONG WITH MINOR FLOODING OF LOW LYING AND POOR DRAINAGE
AREAS WILL BE POSSIBLE. PLUS SOME SMALL STREAMS...CREEKS...AND
BROOKS MAY REACH BANKFULL OR EVEN FLOODING QUICKLY IN THE HEAVY
RAINFALL ASSOCIATED WITH THE THUNDERSTORMS ESPECIALLY IF STORMS
MOVE OVER THE SAME AREA REPEATEDLY.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA
NEAR TERM...IAA/SND/BGM
SHORT TERM...IAA
LONG TERM...WASULA
AVIATION...SND
FIRE WEATHER...IAA
HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS ALBANY NY
1003 AM EDT MON JUN 24 2013
.SYNOPSIS...
VERY WARM AND HUMID CONDITIONS WILL CONTINUE EARLY THIS WEEK WITH
THE THREAT OF SHOWERS AND THUNDERSTORMS MAINLY DURING THE AFTERNOON
AND EVENING HOURS. STORMS WILL HAVE THE POTENTIAL TO PRODUCE LOCALLY
HEAVY RAINFALL. OUR NIGHTS WILL BE CONTINUE TO BE MUGGY WITH PATCHY
FOG. MORE PERSISTENT CHANCES FOR SHOWERS AND THUNDERSTORMS ARE
EXPECTED LATER IN THE WEEK INTO THE WEEKEND AS A SLOW MOVING LOW
PRESSURE SYSTEM IMPACTS THE REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 955 AM...ANOTHER HAZY...HOT AND HUMID DAY SHAPING UP. 12Z ALY
SOUNDING SHOWS PLENTY OF ENERGY FOR AFTERNOON THUNDERSTORMS. WATER
VAPOR LOOP SHOWS CLOSED LOW SPINNING OVER WESTERN PENNSYLVANIA.
THIS UPPER LEVEL LOW IS EXPECTED TO MOVE OVER THE SOUTHERN PART OF
THE ALBANY FORECAST AREA OVER THE NEXT 12-18 HOURS AND SHOULD BE A
FOCUS FOR STORMS. PWAT ON 12Z ALY SOUNDING WAS 1.77 INCHES SO
COPIOUS MOISTURE FOR HEAVY RAINERS. PIT 12Z SOUNDING...UNDER UPPER
LEVEL LOW...HAS STEEPER LAPSE RATES. 12Z HRRR SHOWING A MORE
WIDESPREAD THREAT OF AFTERNOON STORMS. WILL HAVE TO MONITOR FOR
LATER FLASH FLOOD WATCH IF LARGE AREA OF HEAVY RAIN DEVELOPS.
COULD BE AN EXCITING DAY...
PREVIOUS...
THE RIDGE WILL WEAKEN A TAD TODAY AS THE REMNANTS OF THE UPPER
LOW FROM OVER THE TENNESSEE VALLEY MOVES EASTWARD. THIS WILL BE
THE MAIN FEATURE TRIGGERING CONVECTION ACROSS THE AREA TODAY AND
IT WILL ACCOMPANY THE HEATING OF THE DAY. MODEL GUIDANCE SUGGESTS
CAPE VALUES OF PEAKING AT 1000-2000 J/KG WITH DEW POINTS IN THE
MID TO UPPER 60S. LAPSE RATE OF 6 TO 6.5 C/KM ARE EXPECTED THIS
AFTERNOON WITH THE GFS INDICATING 7 C/KM POSSIBLE. MEAN FLOW IS
RATHER WEAK AT 15 TO 20 KNOTS SO STORMS WILL MOVE RATHER SLOWLY
AND CONVECTION WILL BE LOOSELY ORGANIZED. THE STORM PREDICTION
CENTER HAS THE AREA/REGION IN THE GENERAL THUNDERSTORM OUTLOOK FOR
TODAY AND TONIGHT. FREEZING LEVEL IS HIGH JUST OVER 14000 FEET ON
THE 00Z/MON ALY SOUNDING...SO SOME STORMS WILL PRODUCE LOCALLY
HEAVY RAINFALL. THIS ALONG WITH THE RATHER SLOW MOVEMENT HAVE
ADDED ENHANCED WORDING OF HEAVY RAINFALL TO THE FORECAST AND WILL
KEEP MENTION IN THE HAZARDOUS WEATHER OUTLOOK. CONVECTION IS
EXPECTED TO DIMINISH THIS EVENING AS THE WEAKENING UPPER
LOW/TROUGH MOVES OFF TO THE EAST AND WITH THE LOSS OF DAYTIME
HEATING.
LOOKING AT TEMPERATURES IN THE 80S WITH AROUND 90 DEGREES UP THE
HUDSON VALLEY INTO CAPITAL DISTRICT. DEW POINTS WILL BE IN THE MID
TO UPPER 60S MAKING IT FELL EVEN HOTTER. HEAT INDICES SHOULD REACH
THE MID 90S UP THE HUDSON RIVER VALLEY.
ANOTHER MUGGY NIGHT WITH LOWS AND DEW POINTS IN THE 60S. WINDS WILL
BECOME LIGHT TO CALM WINDS. HAVE ADDED PATCHY FOG MAINLY IN THE
RIVER VALLEY LOCATIONS.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
BY TUESDAY MORNING FLOW WILL BECOME NEARLY ZONAL ACROSS THE REGION.
A WEAKENING SURFACE LOW AND MID LEVEL SHORT WAVE TROUGH WILL MOVE
EASTWARD ACROSS SOUTHERN CANADA PASSING WELL TO OUR NORTH TUESDAY.
PLUS GUIDANCE INDICATES SMALL PIECES OF ENERGY SHOULD MOVE THROUGH
THE FLOW FARTHER SOUTH ACROSS OUR REGION.ALL THIS LEADS TO ANOTHER
ROUND OF CONVECTION MAINLY DURING THE AFTERNOON AND EVENING HOURS
TUESDAY WITH THE HEATING OF THE DAY. THE BETTER DYNAMICS AND SHEAR
WILL BE ACROSS NORTHERN NEW YORK INTO NORTHERN NEW ENGLAND AND THIS
IS WHERE THE STORM PREDICTION CENTER HAS GONE WITH A SLIGHT RISK FOR
SEVERE THUNDERSTORMS. FARTHER SOUTH ACROSS OUR FORECAST AREA MEAN
FLOW WILL STILL BE RATHER WEAK AROUND 20 KNOTS. IT WILL BE ANOTHER
HOT DAY SIMILAR TO MONDAY IN TEMPERATURES AND HEAT INDICES.
A WEAK FRONTAL BOUNDARY WILL BE BROUGHT SOUTHWARD INTO THE REGION
TUESDAY NIGHT...HOWEVER DUE TO THE FLOW ALOFT THE BOUNDARY WILL
STALL ACROSS THE REGION. A MORE VIGOROUS SHORT WAVE WILL MOVE INTO
THE LONGWAVE TROUGH OVER THE GREAT LAKES REGION WEDNESDAY AND
WEDNESDAY NIGHT AND HEIGHTS WILL BEGIN TO FALL. CHANCES FOR
CONVECTION WILL NOT BE LIMITED MAINLY TO THE AFTERNOON AND EVENING
HOURS THIS TIME. AS HEIGHTS CONTINUE TO FALL WILL HAVE LARGE SCALE
ASCENT THE BOUNDARY WILL BEGIN TO MOVE BACK NORTHWARD AS A WARM
FRONT.
PRECIPITABLE WATER VALUES WILL STILL BE HIGH SO LOCALLY HEAVY
RAINFALL IS EXPECTED WITH SOME STORMS...SO HAVE MENTIONED IN OUR
HAZARDOUS WEATHER OUTLOOK.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AN UNSETTLED AND WET EXTENDED FORECAST IS LIKELY ACROSS NY AND NEW
ENGLAND WITH PERSISTENT CHANCES OF SHOWERS AND THUNDERSTORMS...AS A
MID AND UPPER LEVEL TROUGH WILL INITIALLY IMPACT THE REGION TO CLOSE
THE WEEK...AND THEN IT MAY CLOSE OR CUT OFF NEAR THE GREAT LAKES
REGION AND SRN ONTARIO FOR THE WEEKEND.
THE LATEST GFS/ECMWF/CANADIAN GGEM/ENSEMBLE GUIDANCE AND HPC
GRAPHICS ARE IN PRETTY GOOD AGREEMENT FOR AN ACTIVE STRETCH OF
WEATHER. THEIR ARE SOME SUBTLE DIFFERENCES FOR THE TIMING OF THE
SHORT-WAVE IMPULSE ROTATING THROUGH THE UPPER LEVEL TROUGH...BUT ALL
AN ALL...IT IS EXTREMELY DIFFICULT TO FIND A SUSTAINED DRY STRETCH
OF WX TO CLOSE JUNE.
THU-FRI...A WAVE OF LOW PRESSURE APPROACHES THE FCST AREA FROM THE
GREAT LAKES REGION WITH SOME OVER RUNNING SHOWERS AND THUNDERSTORMS
AHEAD OF A WARM FRONT. THE WARM FRONT MAY BUST THROUGH PORTIONS OF
THE FCST AREA FOR A POTENTIAL OF STRONG THUNDERSTORMS...IF HEATING
IS REALIZED. THE DETAILS ARE NEBULOUS AND MURKY...SO WE WILL CALL
IT A CHANCE OF SHOWERS AND THUNDERSTORMS...THU INTO THU NIGHT. A
S/SW H850 LLJ OF 30-45 KTS WILL TRANSPORT IN SOME GULF
MOISTURE...AND PWATS WILL CONTINUE TO RUN ABOVE NORMAL. THE SFC LOW
BEGINS TO OCCLUDE AND CLOSE OFF JUST NORTHWEST OF LAKE ONTARIO AND
NRN NY ON FRI. THE GFS CONTINUES TO PAINT MODERATE AMOUNTS OF
INSTABILITY FOR THE POTENTIAL OF SHOWERS AND THUNDERSTORMS AGAIN.
THE SUBTROPICAL HIGH REMAINS ANCHORED DOWNSTREAM CONTINUING A DEEP
S/SW FETCH OF MOISTURE. THIS LONG DURATION STRETCH OF WX...BEGINS
TO MATERIALIZE INTO POTENTIALLY A CLASSIC GREAT LAKES CSTAR CUTOFF
LOW WARM SEASON EVENT. TEMPS LOOK TO RUN SLIGHTLY BELOW TO NEAR
NORMAL FOR THE THESE DAYS WITH HIGHS IN THE M70S TO L80S AND LOWS IN
THE U50S TO 60S.
SAT-MON...THE LONGWAVE TROUGH BEGINS TO AMPLIFY WITH THE EMBEDDED
500 HPA CLOSED CIRCULATIONS OVER THE CNTRL AND ERN GREAT LAKES. A
COLD FRONT BEGINS TO STALL OUT NEAR THE ERN CONUS SEABOARD.
MULTIPLE SHORT-WAVES LIFT NORTHWARD ON THE EAST SIDE OF TROUGH.
PERSISTENT BANDS OF SHOWERS AND THUNDERSTORMS TIMED TO THE DIURNAL
HEATING AND THE PROPAGATION OF THE IMPULSES ARE POSSIBLE FOR THE
WEEKEND INTO EARLY NEXT WEEK. THEIR IS A SMALL POSSIBILITY THAT
DRYING IN THE WAKE OF DISTURBANCES MAY PROMOTE MINI DRY STRETCHES.
AGAIN...THIS APPEARS TO FIT A GREAT LAKES WARM SEASON CSTAR
CLOSED/CUTOFF SCENARIO FOR AN EXTENDED PERIOD OF SHOWERS AND
THUNDERSTORMS. THE WEEKEND IS DOMINATED BY A POSITIVE TILT
SCENARIO...PERHAPS SHIFTING NEUTRAL BY EARLY NEXT WEEK. H850 TEMPS
CONTINUE TO BE IN THE +14C TO +16C RANGE WITH LIMITED HEATING EACH
DAY WITH A RESIDUAL COLD POOL ALOFT...AND THE ACTIVE S/SW FLOW.
EXPECT HIGHS TO CONTINUE IN THE 70S TO L80S WITH LOWS IN THE U50S TO
60S. TOO EARLY TO PINPOINT LOCATIONS...BUT SOME HYDRO PROBLEMS COULD
MATERIALIZE...IF LOCATIONS GET REPEATEDLY HIT BY BANDS OF SHOWERS
AND THUNDERSTORMS.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE NEAR THE MID ATLANTIC REGION WILL CONTINUE TO FUNNEL
NORTHWARD WARM AND HUMID AIR THE NEXT FEW DAYS. A WEAK MID LEVEL
DISTURBANCE MAY FOCUS SOME ISOLD-SCT SHOWERS AND THUNDERSTORMS THIS
AFTERNOON INTO THE EARLY EVENING.
VFR CONDITIONS ARE EXPECTED MOST OF THE DAY. THERE IS THE THREAT OF
SOME DIURNALLY TIMED SHOWERS AND THUNDERSTORMS. OUR CONFIDENCE
REMAINS AT ABOUT 25 TO 30 PERCENT FOR THUNDERSTORMS...SO A VCSH
GROUP HAS BEEN USED IN THE TAFS AT THIS TIME IN THE 18Z-00Z TIME
FRAME. IN THE WAKE OF THE DISTURBANCE THE SKIES WILL CLEAR AND SOME
PATCHY MIST/FOG MAY FORM AGAIN PRIOR OR JUST AFTER MIDNIGHT AT ALL
THE TAF SITES.
THE WINDS WILL INCREASE FROM THE SOUTH TO SOUTHWEST AT 5-10
KTS...AND VEER TO THE WEST TO SOUTHWEST AT AROUND 10 KTS WITH SOME
GUSTS CLOSE TO 20 KTS AT KPSF AND KALB. EXPECT THE WINDS TO BECOME
LIGHT TO CALM IN THE EARLY EVENING.
OUTLOOK...
TUE...MAINLY VFR. CHC -TSRA/-SHRA MAINLY DURING THE AFTN INTO THE
EVNG. MVFR-IFR FOG LATE AT NIGHT INTO EARLY IN THE MORNING.
WED...MAINLY VFR. SLIGHT CHC -TSRA/-SHRA.
THU-FRI...VFR/MVFR. CHC -TSRAS/-SHRAS.
&&
.FIRE WEATHER...
VERY WARM AND HUMID CONDITIONS WILL CONTINUE EARLY THIS WEEK WITH
THE THREAT OF SHOWERS AND THUNDERSTORMS MAINLY DURING THE AFTERNOON
AND EVENING HOURS. STORMS WILL HAVE THE POTENTIAL TO PRODUCE LOCALLY
HEAVY RAINFALL. OUR NIGHTS WILL BE CONTINUE TO BE MUGGY WITH PATCHY
FOG. MORE PERSISTENT CHANCES FOR SHOWERS AND THUNDERSTORMS ARE
EXPECTED LATER IN THE WEEK INTO THE WEEKEND AS A SLOW MOVING LOW
PRESSURE SYSTEM IMPACTS THE REGION.
&&
.HYDROLOGY...
INCREASING UNSETTLED WEATHER THIS WEEK. EARLY IN THE WEEK THE CHANCES
OF SHOWERS AND THUNDERSTORMS WILL BE MAINLY DURING THE AFTERNOON AND
EVENING HOURS. HOWEVER...PERSISTENT CHANCES OF SHOWERS AND
THUNDERSTORMS ARE EXPECTED FOR THE LATER PART OF THE WEEK INTO THE
WEEKEND AS A MID/UPPER LEVEL TROUGH IMPACTS THE REGION.
STORMS WILL HAVE THE POTENTIAL TO PRODUCE LOCALLY HEAVY RAINFALL ALL
WEEK WITH HIGH PRECIPITABLE WATER VALUES. EARLY IN THE WEEK FLOW ALOFT
WILL BE RATHER LIGHT SO STORMS WILL BE SLOWER MOVERS. FLOW IS
EXPECTED TO INCREASE LATER IN THE WEEK. PONDING OF WATER ON
ROADWAYS ALONG WITH MINOR FLOODING OF LOW LYING AND POOR DRAINAGE
AREAS WILL BE POSSIBLE. PLUS SOME SMALL STREAMS...CREEKS...AND
BROOKS MAY REACH BANKFULL OR EVEN FLOODING QUICKLY IN THE HEAVY
RAINFALL ASSOCIATED WITH THE THUNDERSTORMS ESPECIALLY IF STORMS
MOVE OVER THE SAME AREA REPEATEDLY.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA
NEAR TERM...IAA/SND
SHORT TERM...IAA
LONG TERM...WASULA
AVIATION...WASULA
FIRE WEATHER...IAA
HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
959 AM EDT MON JUN 24 2013
.SYNOPSIS...
A BERMUDA HIGH PRESSURE SYSTEM WILL REMAIN OFF THE SOUTHEAST UNITED
STATES COAST FOR THIS UPCOMING WEEK. A BACKDOOR COLD FRONT WILL TRY
TO SINK SOUTHWARD INTO THE FORECAST AREA ON WEDNESDAY AND THURSDAY
BEFORE RETREATING NORTHWARD. A COLD FRONT WILL MOVE THROUGH THE
GREAT LAKES THURSDAY AND FRIDAY IS FORECAST TO APPROACH THE FORECAST
AREA SATURDAY AND MOVE THROUGH BY SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE UPPER LOW NOTED IN WV IMAGERY IS MOVING SLOWLY EWD THRU PA
THIS MORNING RESULTING IN SW FLOW ALOFT AS WELL AS AT THE SFC. 12Z
SOUNDINGS FROM IAD/APG SHOW DECENT CAPE IF CNVCTV TEMPS ARE
REACHED...AND ABOUT 1.5 IN PWAT WHICH IS SOMEWHAT ABOVE NORMAL FOR
THIS TIME OF YEAR. AMS NEAR THE CENTER OF THE UPPER LOW SEEMS TO
BE DRIER BUT COOLER ALOFT SO NOT SURE EXACTLY HOW THIS WILL PLAY
OUT FOR AFTN CONVECTION. BOTH THE RAP AND THE HRRR SHOW CNVTN
DEVELOPING AROUND 17Z. TODAYS TEMPS WERE TWEAKED UP A DEGREE OR
TWO BUT OTRW NO CHANGES TO THE CURRENT FCST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
THE UPPER LEVEL LOW WILL CONTINUE TO PROGRESS TOWARDS THE EAST
TONIGHT AS IT BECOMES LESS AND LESS DEFINED. THE LAST REMNANTS OF
THE EVENING CONVECTION SHOULD ALSO BE MOVING OUT OF THE REGION OR AT
LEAST OVER OUR NORTHERN ZONES BY LATE EVENING. HI-RES MODELS STILL
SHOW A FEW MID-LEVELS RIPPLES PULLING THROUGH IN THE MAINLY ZONAL
FLOW ALOFT SO A FEW PASSING SHOWERS LATE TONIGHT IS STILL POSSIBLE
ALTHOUGH THEY WILL BE MORE ISOLATED.
EXPECT MORE CLEARING TO TAKE PLACE WHEN COMPARED TO SUNDAY NIGHT
WHICH SHOULD ALLOW US TO RADIATE A BIT MORE. THE SURFACE FLOW SHOULD
BECOME LIGHT FROM THE SOUTHWEST...AGAIN, BUT THIS TIME WE COULD SEE
SLIGHTLY COOLER DEWPOINTS ADVECTED INTO THE REGION. ONCE AGAIN NOT
QUITE SURE THE EXTENT OF ANY FOG FORMATION AND QUITE FRANKLY THE
GUIDANCE IS NOT ALL THAT EXCITED EITHER...WILL KEEP IN PATCHY FOG
FOR TONIGHT.
TEMPERATURES TONIGHT SHOULD BE A COUPLE DEGREES COOLER THAN SUNDAY
NIGHT OUTSIDE THE URBAN HEAT ISLAND. USED A BLEND OF THE MET/MAV
WITH HEAVIER WEIGHTING TOWARDS THE COOLER MAV.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
SEVERAL ABOVE NORMAL TEMPERATURE DAYS IN STORE FOR THE AREA WITH
PLENTY OF HUMIDITY ALSO. THE BERMUDA HIGH PRESSURE AREA WILL SLOWLY
LOSE ITS INFLUENCE ON OUR WEATHER AS A DEEPENING TROUGH AND SFC LOW
MOVE INTO THE AREA FRI AND INTO THE WEEKEND. WE HAVE MOSTLY USED WPC
TEMPS/POPS FOR THE OVERNIGHT EXTENDED PACKAGE. THERE WILL BE DAILY
CHCS FOR SHOWERS/TSTMS DURING THE EXTENDED PERIOD. THE ADDED
CLOUDINESS AND SHOWERS WILL TEMPER THE MAGNITUDE OF THE ABOVE NORMAL
TEMPERATURES.
WE ARE FORECASTING HIGH TEMPERATURE READINGS TO REACH THE LOW 90S IN
MANY AREAS TUE-THU WITH PERHAPS A FEW MID 90S ON WED. HUMIDITY
LEVELS WILL BE MODERATE/HIGH WITH DEW POINTS IN THE MID 60S TO
AROUND 70S. THIS WILL PRODUCE APPARENT TEMPERATURES IN THE LOW/MID
90S ACROSS THE AREA. IT MAY BE NECESSARY TO ISSUE SOME HEAT RELATED
HEADLINES AS WE MOVE TOWARD THE MID-WEEK PERIOD. OVERNIGHT LOWS WILL
MOSTLY BE IN THE MID/UPPER 60S WITH SOME LOW 70S ACROSS METRO
PHILADELPHIA.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
A PLUME OF LOW CLDS WITH IFR CIGS FORMED EARLIER THIS MORNING OFF
THE NRN END OF CHES BAY AND AFFECTED BOTH PHL AND ILG FOR A COUPLE
OF HOURS. AS OF 1230Z THESE CLOUDS HAD DISSIPATED AND VFR CONDS
PREVAIL.
TODAY...VFR WITH SOUTHWEST WINDS. A WEAK SURFACE TROUGH WILL PUSH IN
FROM THE WEST THIS AFTERNOON AND COULD PROVIDE ENOUGH LIFT TO SPARK
WIDELY SCATTERED SHOWERS. DID NOT PLACE THESE IN THE TAFS AT THIS
TIME GIVEN LACK OF SPATIAL COVERAGE AND LOW CONFIDENCE ON INITIATION.
TONIGHT...THE SYSTEM THAT HAS BEEN KEEPING THE MID AND HIGH DECK
AROUND FOR THE PAST COUPLE OF DAYS IS FORECAST TO MOVE TO OUR
NORTHEAST TONIGHT. THIS WOULD ALLOW SKIES TO BECOME CLEARER THAN ON
PAST NIGHTS AND FOR BETTER RADIATIONAL COOLING TO TAKE PLACE. ANY
ADDED MOISTURE FROM THE SHOWERS WILL HELP FOR ANOTHER ROUND OF
GROUND FOG TO FORM. DO NOT HAVE THE CONFIDENCE YET TO PLACE IN THE
TAFS BUT WE WILL HAVE A BETTER CHANCE IF SKIES REALLY DO CLEAR OUT.
OUTLOOK...
TUE-WED...MOSTLY VFR WITH SHORT PERIODS OF SUB-VFR IN MORNING FOG
AND/OR SCT SHOWERS/TSTMS.
THU-FRI...VFR/MVFR IN MORE NUMEROUS SHOWERS/TSTMS.
&&
.MARINE...
ANOTHER TRANQUIL DAY IS EXPECTED ACROSS OUR WATERS WITH SOUTHWEST
WINDS AROUND 10-15KTS. STILL COULD SEE SOME GUSTS UPWARDS OF 20KTS
SEAS WILL CONTINUE TO BE AROUND 3 FEET TODAY AND THEN GRADUALLY
BUILD UPWARDS OF 4 FEET BY TONIGHT.
OUTLOOK...
SUB-SCA CONDITIONS MUCH OF THE WEEK WITH MOSTLY SW/S WINDS ON THE
WATERS. SCA WINDS/SEAS POSSIBLE FRI.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...AMC
SHORT TERM...HEAVENER
LONG TERM...O`HARA
AVIATION...AMC/HEAVENER/O`HARA
MARINE...HEAVENER/O`HARA
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
339 PM EDT MON JUN 24 2013
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
500MB SURFACE ANALYSIS SHOWS A TROUGH SITUATED ACROSS NORTHERN
GA...CENTRAL AL AND SOUTHEAST MS. SHOWERS AND THUNDERSTORMS HAVE
DEVELOPED IN THE BASE OF THE TROUGH THIS AFTERNOON...AND CONTINUE TO
APPROACH WESTERN GA. THE LATEST RUN OF THE HRRR HAS THE ACTIVITY
FROM THE WEST CONGEALING WITH THE SE ACTIVITY LATE THIS AFTERNOON.
ACTIVITY SHOULD DECREASE IN STRENGTH AND COVERAGE WITH THE LOSS OF
HEATING FOR THE EARLY EVENING HOURS.
FOR OVERNIGHT...WV LOOP SHOWS A GOOD PIECE OF SHORTWAVE ENERGY
DROPPING SE IN THE FLOW ACROSS W KY THIS AFTERNOON. MODELS DO
DEVELOP SCT ACTIVITY MAINLY ACROSS NORTHERN GA OVERNIGHT. WITH SOME
MARGINAL INSTABILITY PRESENT OVERNIGHT...SCT SHRA/TSRA SEEM VERY
REASONABLE.
THE 500MB TROUGH AXIS IS PROGGED TO BE ACROSS THE CENTRAL CWFA
DURING THE DAY TOMORROW. THIS SHOULD LEAD TO A LITTLE MORE COVERAGE
OF STORMS ACROSS THE REGION. PWATS REMAIN THE SAME ACROSS NORTHERN
GA...BUT WILL CREEP UP TO AROUND 2 INCHES ACROSS THE CENTRAL AND
SOUTHERN CWFA. IN ADDITION...BL WINDS REMAIN VERY LIGHT (AOB
15K)...SO MOVEMENT OF STORMS WILL BE VERY SLOW OR NEARLY STATIONARY.
EVEN THOUGH THE ATMOS WILL BE MARGINALLY UNSTABLE AT THE
SURFACE...MID LEVEL LAPSE RATES AND SHEAR REMAIN VERY WEAK. THE
POTENTIAL FOR SEVERE WEATHER REMAINS LOW...BUT STRONG THUNDERSTORMS
ARE POSSIBLE...WITH AN ISOLATED SEVERE STORM NOT OUT OF THE
QUESTION.
NLISTEMAA
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
DIURNAL CONVECTION EXPECTED TO CONTINUE ACROSS THE AREA EACH
AFTERNOON AND EVENING THROUGH DAY 7. MODELS IN GOOD AGREEMENT
WITH SURFACE RIDGE LOSING ITS GRIP ON THE SOUTHEAST BY WEEKS
END. THEY ARE ALSO IN GOOD AGREEMENT WITH THE UPPER LEVEL RIDGE
BUILDING AND REMAINING OVER THE WESTERN US AS LONG WAVE TROUGH
SETS UP OVER THE EAST COAST BY FRIDAY. WITH THE EASTERN EXTENT OF
THE UPPER LEVEL RIDGE MORE LIMITED THAN PREVIOUSLY EXPECTED...HAVE
COOLED EXTENDED HIGH TEMPERATURES A DEGREE OR TWO. STILL LOOKING
FOR HIGHS IN THE UPPER 80S AND LOW 90S. HAVE INCREASED POPS
SOMEWHAT FOR THE WEEKEND...AND EXPECT THIS UPWARD TREND IN THE
FORECAST TO CONTINUE IN THE COMING DAYS. ENHANCED MOISTURE ACROSS
THE REGION AS A RESULT OF THE UPPER LEVEL TROUGH AND ASSOCIATED
FRONTAL BOUNDARY SHOULD SUPPORT MORE SIGNIFICANT COVERAGE OF
PRECIP ACTIVITY. ANTICIPATE FRONTAL PASSAGE BY EARLY NEXT
WEEK...WITH DROP IN POPS AND SLIGHTLY COOLER TEMPERATURES IN STORE
AS A RESULT.
31/01
&&
.AVIATION...
18Z UPDATE...
NO MAJOR CHANGES TO THE TAFS FOR THIS CYCLE. DIFFERENTIAL HEATING
BOUNDARY AND SHEAR AXIS ALOFT CONTINUE TO DEVELOP SCT SHRA/TSRA
ACROSS NORTHERN GA THIS AFTERNOON. IN ADDITION...A CONVERGENCE
ZONE HAS ALSO DEVELOPED ACROSS THE SE. HAVE GONE VERY CLOSE TO THE
13Z HRRR SOLUTION...WITH THE BEST CHANCE OF TSRA AT ATL BETWEEN 21Z
AND 23Z. COVERAGE SHOULD BE HIGHER TOMORROW AS SHEAR AXIX SLIPS
EAST OVER THE CWFA TOMROROW.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM CONFIDENCE CONVECTIVE TIMING. HIGH CONFIDENCE REMAINING
ELEMENTS.
NLISTEMAA
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 69 87 69 90 / 50 50 20 30
ATLANTA 70 86 71 88 / 50 50 20 30
BLAIRSVILLE 64 81 64 86 / 40 40 20 40
CARTERSVILLE 69 88 69 89 / 50 40 20 30
COLUMBUS 71 91 72 92 / 60 60 20 30
GAINESVILLE 68 85 70 87 / 50 40 20 30
MACON 71 89 71 90 / 60 60 20 30
ROME 68 89 69 91 / 40 40 20 30
PEACHTREE CITY 69 87 69 88 / 50 50 20 30
VIDALIA 72 88 73 92 / 60 60 20 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...NLISTEMAA
LONG TERM....01
AVIATION...NLISTEMAA
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
144 PM EDT MON JUN 24 2013
.PREV DISCUSSION... /ISSUED 1052 AM EDT MON JUN 24 2013/
UPDATE...
500MB ANALYSIS SHOWS A TROUGH ACROSS WESTERN AL. THIS FEATURE HAS
SERVED TO FOCUS MOSTLY SHOWERS THIS MORNING ACROSS NORTH CENTRAL
AL...AND NOW NW GA. DO THINK ANY SCT PRECIP LATE THIS MORNING AND
EARLY AFTERNOON WILL BE CONCENTRATED CLOSEST TO THE TROUGH.
HOWEVER...FOR THE REMAINDER OF THE AFTERNOON...DO THINK PRECIP
WILL FOCUS JUST ALONG AND AHEAD OF THE SEA BREEZE ACROSS THE SE
CWFA. THE 12Z RUN OF THE HRRR SHOWS THIS FAIRLY WELL.
12Z SOUNDING ANALYSIS SHOWS A MOIST COLUMN UP THROUGH 750MB WITH
LIGHT SW FLOW IN THE BOUNDARY LAYER. PWATS ARE AROUND AN INCH AND
THREE QUARTERS...SO ANY THUNDERSTORMS THAT DEVELOP WILL BE CAPABLE
OF PRODUCING LOCALLY HEAVY DOWNPOURS. SURFACE WILL REMAIN PRETTY
UNSTABLE THROUGH THE DAY...SO SCT/NRMS TSTMS WILL BE POSSIBLE. A
FEW THUNDERSTORMS COULD BECOME STRONG AND PRODUCE PROLIFIC
LIGHTNING STRIKES...BUT THE POTENTIAL FOR SEVERE WEATHER IS RATHER
LOW.
PREV DISCUSSION... /ISSUED 734 AM EDT MON JUN 24 2013/
SHORT TERM /TODAY THROUGH TUESDAY/...
/ISSUED AT 402 AM EDT MON JUN 24 2013/
CURRENT CONVECTION OVER THE NORTHEAST MOUNTAINS RESPONDING TO A
MOIST UPSLOPE FLOW ALOFT. THIS WILL SLOWLY SHIFT INTO NORTH CAROLINA
HOWEVER THERE REMAINS ENOUGH OF A RISK TO KEEP LOW POPS GOING INTO
THE MID MORNING HOURS. ISOLATED SHOWERS HAVE ALSO DEVELOPED ACROSS
PARTS OF SOUTH AND EAST GA RESPONDING TO A WEAK SHORT WAVE IN THE
MID LEVELS. THIS KEEPS ENOUGH OF A RISK TO KEEP LOW POPS GOING INTO
THE MID MORNING HOURS AS WELL OVER PARTS OF CENTRAL GA. A SHORT WAVE
MOVING THROUGH THE MISSISSIPPI VALLEY WILL MOVE INTO THE CWA THIS
AFTERNOON. COMBINING THIS WITH AMPLE GULF AND ATLANTIC MOISTURE
SHOULD AID IN SCATTERED TO NUMEROUS THUNDERSTORMS THIS
AFTERNOON...MOST NUMEROUS ACROSS CENTRAL GA WHERE LIKELY POPS SEEM
IN ORDER. CONVECTION SHOULD DIMINISH AFTER SUNSET WITH SOME
LINGERING SHOWERS ACROSS THE NORTHEAST MOUNTAINS AND ALSO CENTRAL GA
INTO THE MORNING HOURS ON TUESDAY.
RISING H5 HEIGHTS WILL INCREASE THICKNESSES TODAY. THIS SHOULD
PRODUCE WARMER TEMPS TODAY. THE NAM IS A BIT COOLER AND HAVE OPTED
FOR THE WARMER GFS BOTH TODAY AND TUESDAY.
17
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
/ISSUED AT 402 AM EDT MON JUN 24 2013/
DIURNAL CONVECTION EXPECTED EACH AFTERNOON AND EVENING THROUGH THE
WEEK. MODELS IN GOOD AGREEMENT WITH SURFACE RIDGE LOSING ITS GRIP
ON THE SOUTHEAST BY WEEKS END...AND UPPER LEVEL RIDGE BUILDING AND
REMAINING OVER THE WESTERN US AS LONG WAVE TROUGH SETS UP OVER THE
EAST COAST BY FRIDAY. WITH THE EASTERN EXTENT OF THE UPPER LEVEL
RIDGE MORE LIMITED THAN PREVIOUSLY EXPECTED...HAVE COOLED EXTENDED
HIGH TEMPERATURES A DEGREE OR TWO. STILL LOOKING FOR HIGHS IN THE
UPPER 80S AND LOW 90S.
HAVE INCREASED POPS SOMEWHAT FOR THE WEEKEND...AND EXPECT THIS
UPWARD TREND IN THE FORECAST TO CONTINUE IN THE COMING DAYS. ENHANCED
MOISTURE ACROSS THE REGION AS A RESULT OF THE UPPER LEVEL TROUGH
AND ASSOCIATED FRONTAL BOUNDARY SHOULD SUPPORT MORE SIGNIFICANT
COVERAGE OF PRECIP ACTIVITY. ANTICIPATE FRONTAL PASSAGE BY EARLY NEXT
WEEK...WITH DROP IN POPS AND SLIGHTLY COOLER TEMPERATURES IN STORE
AS A RESULT.
31
&&
.AVIATION...
18Z UPDATE...
NO MAJOR CHANGES TO THE TAFS FOR THIS CYCLE. DIFFERENTIAL HEATING
BOUNDARY AND SHEAR AXIS ALOFT CONTINUE TO DEVELOP SCT SHRA/TSRA
ACROSS NORTHERN GA THIS AFTERNOON. IN ADDITION...A CONVERGENCE
ZONE HAS ALSO DEVELOPED ACROSS THE SE. HAVE GONE VERY CLOSE TO THE
13Z HRRR SOLUTION...WITH THE BEST CHANCE OF TSRA AT ATL BETWEEN 21Z
AND 23Z. COVERAGE SHOULD BE HIGHER TOMORROW AS SHEAR AXIX SLIPS
EAST OVER THE CWFA TOMROROW.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM CONFIDENCE CONVECTIVE TIMING. HIGH CONFIDENCE REMAINING
ELEMENTS.
NLISTEMAA
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 87 69 89 70 / 50 50 50 20
ATLANTA 88 71 88 72 / 50 50 50 20
BLAIRSVILLE 83 63 84 65 / 40 40 40 20
CARTERSVILLE 87 68 88 70 / 50 50 40 20
COLUMBUS 91 73 92 73 / 50 50 60 20
GAINESVILLE 86 69 88 71 / 50 50 40 20
MACON 89 70 91 72 / 60 60 60 20
ROME 89 68 91 70 / 40 40 40 20
PEACHTREE CITY 88 68 90 70 / 50 50 50 20
VIDALIA 91 73 91 74 / 60 60 60 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
1052 AM EDT MON JUN 24 2013
.UPDATE...
500MB ANALYSIS SHOWS A TROUGH ACROSS WESTERN AL. THIS FEATURE HAS
SERVED TO FOCUS MOSTLY SHOWERS THIS MORNING ACROSS NORTH CENTRAL
AL...AND NOW NW GA. DO THINK ANY SCT PRECIP LATE THIS MORNING AND
EARLY AFTERNOON WILL BE CONCENTRATED CLOSEST TO THE TROUGH.
HOWEVER...FOR THE REMAINDER OF THE AFTERNOON...DO THINK PRECIP
WILL FOCUS JUST ALONG AND AHEAD OF THE SEA BREEZE ACROSS THE SE
CWFA. THE 12Z RUN OF THE HRRR SHOWS THIS FAIRLY WELL.
12Z SOUNDING ANALYSIS SHOWS A MOIST COLUMN UP THROUGH 750MB WITH
LIGHT SW FLOW IN THE BOUNDARY LAYER. PWATS ARE AROUND AN INCH AND
THREE QUARTERS...SO ANY THUNDERSTORMS THAT DEVELOP WILL BE CAPABLE
OF PRODUCING LOCALLY HEAVY DOWNPOURS. SURFACE WILL REMAIN PRETTY
UNSTABLE THROUGH THE DAY...SO SCT/NRMS TSTMS WILL BE POSSIBLE. A
FEW THUNDERSTORMS COULD BECOME STRONG AND PRODUCE PROLIFIC
LIGHTNING STRIKES...BUT THE POTENTIAL FOR SEVERE WEATHER IS RATHER
LOW.
&&
.PREV DISCUSSION... /ISSUED 734 AM EDT MON JUN 24 2013/
SHORT TERM /TODAY THROUGH TUESDAY/...
/ISSUED AT 402 AM EDT MON JUN 24 2013/
CURRENT CONVECTION OVER THE NORTHEAST MOUNTAINS RESPONDING TO A
MOIST UPSLOPE FLOW ALOFT. THIS WILL SLOWLY SHIFT INTO NORTH CAROLINA
HOWEVER THERE REMAINS ENOUGH OF A RISK TO KEEP LOW POPS GOING INTO
THE MID MORNING HOURS. ISOLATED SHOWERS HAVE ALSO DEVELOPED ACROSS
PARTS OF SOUTH AND EAST GA RESPONDING TO A WEAK SHORT WAVE IN THE
MID LEVELS. THIS KEEPS ENOUGH OF A RISK TO KEEP LOW POPS GOING INTO
THE MID MORNING HOURS AS WELL OVER PARTS OF CENTRAL GA. A SHORT WAVE
MOVING THROUGH THE MISSISSIPPI VALLEY WILL MOVE INTO THE CWA THIS
AFTERNOON. COMBINING THIS WITH AMPLE GULF AND ATLANTIC MOISTURE
SHOULD AID IN SCATTERED TO NUMEROUS THUNDERSTORMS THIS
AFTERNOON...MOST NUMEROUS ACROSS CENTRAL GA WHERE LIKELY POPS SEEM
IN ORDER. CONVECTION SHOULD DIMINISH AFTER SUNSET WITH SOME
LINGERING SHOWERS ACROSS THE NORTHEAST MOUNTAINS AND ALSO CENTRAL GA
INTO THE MORNING HOURS ON TUESDAY.
RISING H5 HEIGHTS WILL INCREASE THICKNESSES TODAY. THIS SHOULD
PRODUCE WARMER TEMPS TODAY. THE NAM IS A BIT COOLER AND HAVE OPTED
FOR THE WARMER GFS BOTH TODAY AND TUESDAY.
17
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
/ISSUED AT 402 AM EDT MON JUN 24 2013/
DIURNAL CONVECTION EXPECTED EACH AFTERNOON AND EVENING THROUGH THE
WEEK. MODELS IN GOOD AGREEMENT WITH SURFACE RIDGE LOSING ITS GRIP
ON THE SOUTHEAST BY WEEKS END...AND UPPER LEVEL RIDGE BUILDING AND
REMAINING OVER THE WESTERN US AS LONG WAVE TROUGH SETS UP OVER THE
EAST COAST BY FRIDAY. WITH THE EASTERN EXTENT OF THE UPPER LEVEL
RIDGE MORE LIMITED THAN PREVIOUSLY EXPECTED...HAVE COOLED EXTENDED
HIGH TEMPERATURES A DEGREE OR TWO. STILL LOOKING FOR HIGHS IN THE
UPPER 80S AND LOW 90S.
HAVE INCREASED POPS SOMEWHAT FOR THE WEEKEND...AND EXPECT THIS
UPWARD TREND IN THE FORECAST TO CONTINUE IN THE COMING DAYS. ENHANCED
MOISTURE ACROSS THE REGION AS A RESULT OF THE UPPER LEVEL TROUGH
AND ASSOCIATED FRONTAL BOUNDARY SHOULD SUPPORT MORE SIGNIFICANT
COVERAGE OF PRECIP ACTIVITY. ANTICIPATE FRONTAL PASSAGE BY EARLY NEXT
WEEK...WITH DROP IN POPS AND SLIGHTLY COOLER TEMPERATURES IN STORE
AS A RESULT.
31
AVIATION...
12Z UPDATE...
WIDESPREAD IFR CIGS SHOULD LIFT TO MVFR BY MID MORNING AND VFR BY
NOON. EXPECT CONVECTION TO START AROUND NOON AND BECOME SCATTERED
ACROSS NORTH GA AND NUMEROUS ACROSS CENTRAL GA. THE CONVECTION
SHOULD DISSIPATE AFTER SUNSET. WINDS WILL BE SOUTHWEST THROUGH THE
FORECAST BUT WITH SPEEDS LESS THAN 10 KTS. IFR CIGS SHOULD DEVELOP
LATE TONIGHT ACROSS THE FORECAST AREA.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM ON CIG HGTS EARLY THIS MORNING.
HIGH ON OCCURRENCE OF CONVECTION THIS AFTERNOON...LOW ON IMPACTS TO
ATL.
17
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 87 69 89 70 / 40 40 30 20
ATLANTA 88 71 88 72 / 30 30 30 20
BLAIRSVILLE 83 63 84 65 / 40 40 30 20
CARTERSVILLE 87 68 88 70 / 30 30 30 20
COLUMBUS 91 73 92 73 / 60 60 30 20
GAINESVILLE 86 69 88 71 / 40 40 30 20
MACON 89 70 91 72 / 60 60 30 20
ROME 89 68 91 70 / 30 30 30 20
PEACHTREE CITY 88 68 90 70 / 40 40 30 20
VIDALIA 91 73 91 74 / 60 60 30 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...LISTEMAA
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1019 PM CDT TUE JUN 25 2013
.MESOSCALE DISCUSSION...845 PM CDT
MCV MENTIONED IN PREVIOUS UPDATE CONTINUES TO TRACK TO THE EAST-
SOUTHEAST ACROSS THE CWA PER GOES SATELLITE EXTRAPOLATION.
EXPECTATION IS THAT THIS CIRCULATION WILL MOVE OUT OF THE
EAST/SOUTHEAST COUNTIES BY 10 PM CDT. CONVECTION WHICH CONTINUES
TO BUBBLE OVER LAKE MICHIGAN/NORTHWEST INDIANA AND OVER THE SOUTH
END OF THE LAKE WILL LIKELY CONTINUE FOR THE NEXT 1-2 HOURS AS THE
MCV COMPLETES ITS TRANSIT OF THE AREA BEFORE MOVING EAST OF THE
FORECAST AREA. SUBSIDENCE/STABILIZATION IN THE IMMEDIATE WAKE OF
THIS FEATURE WILL LIKELY SUPPRESS NEW DEVELOPMENT ACROSS THE
CENTRAL PART OF THE NRN IL CWA FOR A COUPLE OF HOURS...AND
THEREFORE AFTER COLLABORATION WITH SPC HAVE DECIDED TO REMOVE
LASALLE...KENDALL...GRUNDY AND WILL COUNTIES FROM SEVERE
THUNDERSTORM WATCH 363.
WHILE PREVIOUS CONVECTION HAS STABILIZED LOW LEVELS ACROSS THE
SOUTHERN TIER OF OUR CWA COUNTIES IN 363...INCREASING SOUTHERLY LOW
LEVEL JET AS NOTED IN VWP/S TO OUR WEST/SOUTHWEST HAS RESULTED IN
DEVELOPMENT OF NEW DEEP/STRONG CONVECTION ACROSS WESTERN IL AND
THESE STORMS MAY PERSIST ABOVE COLD POOL AND MAINTAIN A SEVERE
THREAT INTO THE PONTIAC/KANKAKEE AREAS IN ANOTHER 1-2 HOURS.
LOOKING FARTHER WEST...MID-LEVEL SHORT WAVE ACROSS THE MID-MISSOURI
VALLEY WAS NOTED IN GOES VAPOR IMAGERY. LAST VIS IMAGES OF THE
EVENING SHOW ACCAS FIELD OVER WESTERN/CENTRAL IA...WITH 3000-4000
J/KG OF MUCAPE INDICATED PER SPC/RAP MESOANALYSIS. CONVECTION
ALLOWING MODELS INCLUDING WRF-NMM AND HRRR RUNS CONTINUE TO IMPLY
THAT THE IA/WESTERN IL AREA WILL BECOME/REMAIN ACTIVE OVERNIGHT...
WITH ONE OR MORE CLUSTERS OF STORMS POTENTIALLY AFFECTING PARTS OF
THE CWA INTO EARLY WEDNESDAY MORNING. 23Z HRRR RUN SEEMS TO HAVE A
REASONABLE HANDLE ON THIS SCENARIO...WITH ACTIVITY CURRENTLY
DEVELOPING OVER WESTERN/CENTRAL IL PERHAPS AFFECTING OUR SOUTHERN
COUNTIES THROUGH 05-07Z...THEN DEPICTING DEVELOPMENT OVER
CENTRAL/EASTERN IA SPREADING ACROSS NRN IL DURING THE PRE-DAWN HOURS.
HEAVY RAINFALL/SEVERE RISK CONTINUE OVERNIGHT...WITH WARM/MOIST AND
UNSTABLE AIR MASS.
RATZER
&&
.DISCUSSION...
256 PM CDT
SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT...
THE ACTIVE WEATHER EXPECTED OVER THE NEXT 24 TO 30 HOURS...INCLUDING
THE SEVERE WEATHER AND FLASH FLOODING THREAT WILL BE THE FOCUS OF
THE SHORT TERM FORECAST.
DUE TO THE INCREASING THREAT FOR PERIODS OF VERY HEAVY RAINFALL IN
SLOW MOVING STORMS TONIGHT INTO WEDNESDAY...I HAVE EXTENDED THE
FLASH FLOOD WATCH FOR THE ENTIRE AREA AND EXTENDED THROUGH
WEDNESDAY.
REGIONAL SATELLITE WATER VAPOR IMAGERY INDICATES AN UPPER LEVEL
DISTURBANCE CURRENTLY MOVING INTO NORTHWESTERN ILLINOIS. AREA VWP
DATA ACROSS EASTERN IOWA AND SOUTHERN WISCONSIN INDICATE THAT THIS
DISTURBANCE IS ASSOCIATED WITH A MID LEVEL SPEED MAX AROUND 50 KT.
THIS IS RESULTING IN AROUND 40 KT OF 0-6 KM SHEAR...PER SPC
MESO-ANALYSIS. THE AIR MASS AHEAD OF THIS FEATURE...ACROSS NORTHERN
ILLINOIS...HAS BECOME INCREASINGLY UNSTABLE OVER THE PAST FEW
HOURS...WITH SURFACE TEMPERATURES IN THE LOW TO MID 80S AND DEW
POINTS IN THE LOWER 70S...ESPECIALLY TO THE SOUTH OF THE SURFACE
BOUNDARY...CURRENTLY IN PLACE ACROSS FAR NORTHERN ILLINOIS.
MODIFYING THE 12 UTC ILX SOUNDING...THIS RESULTS IN AROUND 3500 J/KG
OF MLCAPE WITH LITTLE TO NO CAPE. NOT SURPRISING...THAT
THUNDERSTORMS ARE BEGINNING TO FIRE ACROSS PORTIONS OF CENTRAL
ILLINOIS AS ASCENT CONTINUES TO OVERSPREAD THIS UNSTABLE
ENVIRONMENT. I EXPECT THIS TREND TO CONTINUE...ESPECIALLY ACROSS
SOUTHERN SECTIONS OF THE AREA...WITH THE POTENTIAL OF AN
ORGANIZING FORWARD PROPAGATING CONVECTIVE COMPLEX WITH STRONG
DAMAGING WINDS BEING THE MAIN THREAT. HOWEVER...THE THREAT FOR
SEVERE HAIL WILL ALSO BE A CONCERN...ESPECIALLY EARLY IN THE EVENT.
THIS ACTIVITY WILL LIKELY CONTINUE INTO THE EARLY EVENING.
ADDITIONAL ROUNDS OF CONVECTION ARE LIKELY AGAIN THIS EVENING AND
OVERNIGHT...WITH THE POTENTIAL FOR SLOW MOVING AND BACK BUILDING
THUNDERSTORMS. THE QUASI-ZONAL FLOW PATTERN ACROSS THE CONUS IS IN
THE PROCESS OF AMPLIFYING...IN RESPONSE TO AN UPPER LOW OVER THE
EASTERN PACIFIC. ULTIMATELY THIS WILL SET THE STAGE FOR A BUILDING
MID/UPPER LEVEL RIDGE ACROSS THE WESTERN CONUS AND FALLING HEIGHTS
ACROSS THE GREAT LAKES REGION. THIS PROCESS SHOULD ALLOW
ANOTHER...STRONGER SHORT WAVE...CURRENTLY NOTED IN THE WATER VAPOR
IMAGERY ACROSS THE PLAINS...TO MOVE ACROSS THE AREA BY WEDNESDAY. A
SOUTHWESTERLY LOW LEVEL JET WILL KICK UP AHEAD OF THIS FEATURE
DURING THE EVENING...AND GUIDANCE CONTINUES TO PLACE THE NOSE OF THIS
LOW LEVEL JET RIGHT ACROSS THE AREA TONIGHT. THIS COULD POTENTIALLY
LEAD TO A DECENT FLASH FLOODING EVENT FOR PORTIONS OF THE AREA
TONIGHT INTO WEDNESDAY...WITH A GOOD POTENTIAL FOR SLOW MOVING AND
BACK BUILDING THUNDERSTORMS. CORFIDI VECTORS ARE PROGGED TO BE 5
KT OR LESS TONIGHT AS THE JET VEERS WEST-SOUTHWESTERLY AND OFFSETS
THE CLOUD BEARING FLOW. CONSIDERING THIS...AND THE FACT THAT FLASH
FLOOD GUIDANCE REMAINS LOW ACROSS THE AREA...I DECIDED TO GO
WITH A FLASH FLOOD WATCH FOR THE ENTIRE AREA.
IT APPEARS THESE STORMS WITH HEAVY RAIN WILL CONTINUE INTO THE EARLY
MORNING HOURS ON WEDNESDAY AND THEN INTENSIFY IN STRENGTH BY THE
AFTERNOON...ESPECIALLY ACROSS MY SOUTHERN AND EASTERN AREAS. THIS
COULD ALSO LEAD TO ADDITIONAL SEVERE STORMS...ESPECIALLY SOUTH. IT
IS POSSIBLY THAT THE MORNING ACTIVITY COULD LIMIT THE SEVERE RISK TO
THE NORTH.
KJB
LONG TERM...THURSDAY THROUGH TUESDAY...
350 PM CDT
AMPLIFICATION OF THE WESTERN CONUS RIDGE AND EASTERN TROUGH WILL
BEGIN TO INFLUENCE THE LOCAL AREA BY LATE WEDNESDAY INTO THURSDAY
AFTER A SURFACE TROUGH PUSHES THROUGH THE AREA AND WINDS AT ALL
LEVELS TURN TO THE NORTHWEST. LOW LEVEL WARMTH AND HUMIDITY DO NOT
REALLY DEPART UNTIL FRIDAY WHEN THE EXPANDING EASTERN TROUGH PUSHES
THE UPPER JET SOUTH OF THE AREA AND USHERS IN DRIER AND MILDER AIR.
ON BOTH THURSDAY AND FRIDAY IT WOULD NOT TAKE MUCH OF A WRINKLE IN
THE UPPER FLOW TO SUPPORT AN AFTERNOON SHOWER...SO SLIGHT CHANCE
POPS HAVE BEEN MAINTAINED ON BOTH DAYS. BY THE WEEKEND THE
CONVECTIVE INSTABILITY APPEARS TO HAVE DECREASED...BUT THE PRESENCE
OF BOTH A SURFACE AND UPPER LEVEL TROUGH DROPPING SOUTH ACROSS THE
AREA WILL STILL SUPPORT LARGE SCALE LIFT...PRIMARILY TO THE SOUTH ON
SUNDAY. PRECIP CHANCES FINALLY DECREASE BY EARLY NEXT WEEK AS THE
SURFACE AND UPPER SUPPORT DIMINISH...BUT UNSEASONABLY COOL AIR
REMAINS IN PLACE WITH CONTINUED NORTH TO NORTHEASTERLY WINDS.
LENNING
JEE
&&
.HYDROLOGY...
1016 PM CDT
REDEVELOPMENT OF THUNDERSTORMS LATER THIS AFTERNOON INTO TONIGHT
IS LIKELY...WITH PERIODS OF HEAVY RAINFALL EXPECTED TO ACCOMPANY
THESE THUNDERSTORMS. GUIDANCE CONTINUES TO FAVOR PRECIPITABLE
WATER VALUES AROUND 2.00". ANOTHER DECENT MID LEVEL DISTURBANCE
IS EXPECTED TO APPROACH THE AREA TONIGHT AND INTO WEDNESDAY...AND
THIS SYSTEM LOOKS TO INDUCE A SOUTHWESTERLY LOW LEVEL JET...THAT
COULD OFFSET THE FORWARD STORM MOTION...RESULTING IN SLOW MOVING
OR BACK BUILDING THUNDERSTORMS TONIGHT INTO WEDNESDAY. AT THIS
TIME...UNCERTAINTY REMAINS AS TO WHERE EXACTLY THE HEAVIEST RAIN
WILL FALL...BUT GUIDANCE CONTINUES TO HINT AT NORTHERN ILLINOIS
AND NORTHWESTERN INDIANA. THIS WILL HAVE TO BE WATCHED FOR
POSSIBILITY OF A FLASH FLOOD WATCH FOR MOST OF THE AREA AS
RAINFALL AMOUNTS IN EXCESS OF 2 INCHES IS CERTAINLY POSSIBLE
ACROSS PORTIONS OF THE AREA.
KJB/BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* TSRA PSBL LATE TONIGHT/EARLY WEDNESDAY MORNING.
* HEAVY RAIN AND MVFR VSBY LIKELY WITH THE TSRA.
* ADDITIONAL ROUND OF TSRA PSBL WEDNESDAY AFTERNOON.
* LAKE BREEZE PSBL WEDNESDAY AFTERNOON WITH WINDS BCMG NE.
JEE
//DISCUSSION...UPDATED 03Z...
THUNDERSTORM ACTIVITY HAS INCREASED ACROSS CENTRAL IL AND
EXPECTING ADDITIONAL CONVECTION TO DEVELOP OVER IA SOON. THE
CONVECTION WILL CONTINUE EAST MAINLY IMPACTING AREAS ALONG AND
SOUTH OF I-80. HOWEVER GUIDANCE SUGGESTS SOME OF THE CONVECTION
MAY SHIFT NORTH. MDW AND GYY LOOK LIKE THE BEST BETS FOR
TSRA IF IT SHIFTS NORTH. STORMS MAY NOT MOVE NORTH ENOUGH TO
IMPACT ORD...DPA...AND ESPECIALLY RFD. HOWEVER MY CONFIDENCE IS
NOT HIGH ENOUGH TO KEEP TSRA OUT OF THOSE TAFS. HEAVY
RAIN...STRONG WINDS...AND LARGE HAIL ARE THE MAIN THREATS WITH THE
STRONG STORMS.
PREVIOUS DISCUSSION...00Z...
WEAK SURFACE FRONTAL BOUNDARY REMAINS DRAPED WEST-EAST ACROSS THE
AREA ROUGHLY JUST SOUTH OF AND PARALLEL TO THE IL-WI STATE LINE.
THIS BOUNDARY ALONG WITH SEVERAL OUTFLOW BOUNDARIES REMAIN
POSSIBLE FOCUSING MECHANISMS FOR ADDITIONAL THUNDERSTORM
DEVELOPMENT THIS EVENING. ATMOSPHERIC ASCENT MAY ALSO BE ENHANCED
BY AN UPPER LEVEL DISTURBANCE ROTATING ACROSS NRN IL THIS EVENING.
LOW LEVEL INFLOW ALSO EXPECTED TO INCREASE OVERNIGHT.
WEAK LAKE BREEZE EVIDENT ON ORD TERMINAL RADAR HAS SLOWED
TREMENDOUSLY AND NEARLY STALLED JUST EAST OF ORD AND MDW AT 00Z.
MAY SEE BOUNDARY INCH SOMEWHAT CLOSER AND WINDS FLOP OVER TO NNE FOR
A BRIEF PERIOD OR GO VARIABLE... BEFORE SOUTHWESTERLY FLOW
REESTABLISHES ITSELF LATER THIS EVENING.
ED F
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* MEDIUM CONFIDENCE IN TSRA TONIGHT...MEDIUM LOW CONFIDENCE WITH
TIMING.
* MEDIUM-LOW CONFIDENCE IN COVERAGE AND TIMING OF TSRA WEDNESDAY
AFTERNOON.
* MEDIUM CONFIDENCE IN LAKE BREEZE.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY AND FRIDAY...GENERALLY VFR OUTSIDE OF COUPLE OF BRIEF PERIODS
OF THUNDERSTORMS.
SATURDAY THROUGH MONDAY...GENERALLY VFR. A COUPLE OF BRIEF PERIODS
OF SHOWERS.
ED F
&&
.MARINE...
234 PM CDT
A LARGE RIDGE OF HIGH PRESSURE WILL PERSIST ACROSS THE SOUTHEAST
STATES THROUGH MID WEEK WHILE A TROUGH OF LOW PRESSURE OVER THE
CENTRAL PLAINS SHIFTS INTO THE UPPER MISSOURI VALLEY THIS EVENING
AND THE UPPER MISSISSIPPI VALLEY WEDNESDAY. THIS WILL KEEP
GENERALLY SOUTHERLY WINDS OVER THE LAKE THROUGH WEDNESDAY. THE
TROUGH WILL THEN DRIFT ACROSS LAKE MICHIGAN WEDNESDAY
EVENING...WITH WINDS GRADUALLY SHIFTING TO MORE NORTHERLY. THE
SOUTHERN END OF THE TROUGH WILL CLOSE OFF INTO A CLOSED LOW OVER
THE EASTERN GREAT LAKES THURSDAY AFTERNOON AND TRACK NORTH INTO
SOUTHERN QUEBEC BY FRIDAY NIGHT. A SECONDARY SURGE OF COOLER AIR
WILL PUSH ACROSS THE LAKE INCREASING WINDS TO 15 TO 20 KT.
NORTHERLY WINDS OF 10 TO 15 KT WILL PERSIST OVER THE LAKE THROUGH
THE END OF THE PERIOD.
KREIN
&&
.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 WEDNESDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 7
PM WEDNESDAY.
LM...NONE.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
901 PM CDT TUE JUN 25 2013
.DISCUSSION...
ISSUED 900 PM CDT TUE JUN 25 2013
THE STORMS HAVE BECOME LESS NUMEROUS IN COVERAGE OVER THE LAST
COUPLE OF HOURS...ALTHOUGH INDIVIDUAL CLUSTERS OF STORMS HAVE
MAINTAINED SOME VIGOROUS UPDRAFTS WITH LARGE AMOUNTS OF MOISTURE
ALOFT AND VERY HEAVY RAINFALL AND SOME HAIL. WITH COOLING OF
SURFACE TEMPS...WE ARE LOSING SURFACE BASED CAPE. HOWEVER...STORMS
APPEAR TO BE SURVIVING BY BECOMING ELEVATED...WITH A CONTINUED
THREAT OF VERY HEAVY RAIN AND SOME HAIL...BUT LOWER CHANCES OF
WIND DAMAGE.
AS FOR THE TRENDS FOR THE REST OF THE NIGHT...WITH EACH SUCCESSIVE
HOUR OF THE HRRR MODEL...IT HAS SLOWED DOWN THE ARRIVAL OF OUR
LATE NIGHT CONVECTIVE COMPLEX FROM IOWA. IT HAS PICKED UP ON THE
RENEWED CONVECTION IN OUR WESTERN COUNTIES AND IT SHOWS THEM
PROGRESSING TO THE NORTHEAST THEN EAST. A LARGER COMPLEX OF STORMS
IS STILL INDICATED TO ARRIVE IN OUR NW COUNTIES FROM THE NORTHWEST
TOWARD 11Z/6AM. WILL KEEP AND EYE ON TIMING BASED ON SATELLITE AND
RADAR TRENDS...BUT FOR NOW WILL ADJUST LIKELY POPS TO LATER
TONIGHT FOR THE NW COUNTIES. WILL ALSO ADJUST THE WED MORNING
LIKELY POPS BACK TO THE NORTHWEST INSTEAD OF JUST SOUTHEAST OF
I-70. WE MAY BE SEEING THE HRRR CONTINUE TO ADJUST THE TIMING OF
THE NEXT COMPLEX UNTIL IT BECOMES OUR MAIN SEVERE WEATHER PRODUCER
DURING THE DAY ON WEDNESDAY.
UPDATED WEATHER INFORMATION IS ALREADY AVAILABLE.
SHIMON
&&
.AVIATION...
ISSUED 659 PM CDT TUE JUN 25 2013
LINE OF CONVECTION CURRENTLY STRETCHES FROM NEAR KDNV TO
KTAZ...JUST SOUTH OF THE I-72 TERMINALS. WINDS IMMEDIATELY BEHIND
THE LINE WILL VEER TO THE N/NE FOR A COUPLE OF HOURS BEFORE
GRADUALLY RETURNING TO A MORE SOUTHERLY DIRECTION AFTER 02-03Z.
LATEST SATELLITE/RADAR MOSAIC SHOWS WIDELY SCATTERED STORMS
DEVELOPING FURTHER WEST ACROSS WEST-CENTRAL ILLINOIS INTO
IOWA...HOWEVER THESE CELLS SHOULD DISSIPATE AS THEY TRACK EASTWARD
INTO A MORE STABLE ENVIRONMENT ALONG/EAST OF I-55. WILL CARRY VCTS
AT THE TAF SITES THROUGH MID-EVENING ACCORDINGLY. MAIN EMPHASIS
WILL THEN SHIFT TO THE OVERNIGHT HOURS...AS HRRR SUGGESTS ANOTHER
COMPLEX OF STORMS DEVELOPING ACROSS IOWA THEN TRACKING E/SE INTO
CENTRAL ILLINOIS TOWARD DAWN. WILL CARRY PREDOMINANT THUNDER AFTER
10Z AT KPIA...THEN AFTER 12Z FURTHER EAST AT KDEC. AFTER A 3-4
HOUR PERIOD OF CONVECTION WEDNESDAY MORNING...A LULL IN THE
ACTIVITY MAY DEVELOP. DUE TO UNCERTAINTY...WILL ONLY MENTION VCTS
FROM MID MORNING THROUGH MID-AFTERNOON WHEN COLD FRONT PUSHES
THROUGH THE AREA AND SHIFTS BETTER STORM CHANCES FURTHER EAST INTO
INDIANA. WINDS WILL BE SOUTHERLY AT LESS THAN 10KT TONIGHT...THEN
WILL BECOME WESTERLY BY WEDNESDAY AFTERNOON.
BARNES
&&
.PREV DISCUSSION...
ISSUED 300 PM CDT TUE JUN 25 2013
SEVERE STORM CHANCES WILL REMAIN THE FOCUS OVER THE NEXT 2 DAYS.
FLASH FLOODING POTENTIAL TONIGHT IN THE NORTH WILL ALSO BE A
CONCERN. BEYOND THAT...AN AIRMASS CHANGE IS PROJECTED FOR LATE
THIS WEEK AND WEEKEND. HOWEVER...A CUTOFF UPPER LOW LINGERING OVER
THE HEARTLAND WILL KEEP SHOWERS AND EVEN ISOLATED THUNDERSTORMS IN
THE FORECAST THROUGH EARLY NEXT WEEK.
SHORT TERM...TONIGHT THROUGH FRIDAY.
WE DECIDED TO PUT OUR 5 NORTHERN COUNTIES IN A FLASH FLOOD THROUGH
TONIGHT DUE TO PREVIOUS 3-5 INCH RAINS EARLY MONDAY MORNING AND
THE POTENTIAL FOR ADDITIONAL VERY HEAVY RAINFALL RATES UP TO 2
INCHES AN HOUR WITH ANY THUNDERSTORMS THROUGH TONIGHT. PWATS
REMAIN IN THE 1.7-1.9" RANGE...AND PERIODIC STORMS IN AN EAST-WEST
LINE ACROSS N IL IS POSSIBLE.
ADJUSTING OUR 12Z SOUNDING FOR CURRENT CONDITIONS SHOWS ML-CAPE
VALUES APPROACHING 3500 J/KG ACROSS OUR AREA...WITH LITTLE TO NO
CIN. VARIOUS BOUNDARIES ACROSS THE AREA FROM YESTERDAYS CONVECTION
HAVE ALREADY BEGUN TO FIRE BETWEEN 18-19Z. WATER VAPOR PIX CONFIRM
A SHORTWAVE IN THE FLOW ACROSS IOWA PROGRESSING EAST-NE. THAT WAVE
SHOULD HELP RAMP UP THE COVERAGE OF STORMS AND POSSIBLY PUSH US
INTO SEVERE WEATHER MODE. FREEZING LEVEL AT 14.4K FT MEANS HAIL
WILL NEED INTENSE UPDRAFTS TO REACH SEVERE LEVELS /1"+/...BUT WE HAVE
THE CAPE TO ACCOMPLISH THAT WITH THE STRONGEST STORMS. WIND SHEAR
WILL BE GRADUALLY INCREASING AS WE HEAD INTO THIS EVENING...SO
ROTATING SUPERCELLS WILL BE POSSIBLE AS THE EVENT PROGRESSES.
THE LATEST HRRR IS INDICATING TWO PERIODS OF STORMS POSSIBLE. WE
EXPECT A WAVE OF STORMS THIS EVENING THAT MAY BE FOLLOWED BY
ANOTHER BOWING COMPLEX OF STORMS ROLLING INTO OUR AREA FROM IOWA
REACHING KNOX COUNTY AROUND 06Z/1AM. THOSE STORMS MAY BE STILL
AFFECTING OUR COUNTIES SE OF I-70 WED MORNING BEFORE THEY DEPART
INTO INDIANA. WE WENT WITH SOME LIKELY POPS IN THE MORNING TO
ACCOUNT FOR THAT.
THEN A BREAK IN THE ACTION MAY DEVELOP THE REST OF WED MORNING AS
THE ATMOSPHERE RECHARGES FOR THE AFTERNOON WAVE OF STRONG TO
SEVERE STORMS. IT APPEARS THAT A LINE OF STORMS WILL DEVELOP
ACROSS WEST CENTRAL ILLINOIS BY MID AFTERNOON...THEN PROGRESS
EASTWARD. AN INCREASING LLJ IS EXPECTED TO COINCIDE WITH UPPER
LEVEL WINDS VEERING TO THE NORTHWEST. THAT WILL INCREASE SHEAR AND
HELICITY PARAMETERS AND RAMP UP THE THREAT OF ROTATING STORMS AND
POSSIBLY A FEW TORNADOES...MAINLY EAST OF I-55. WE INCREASED POPS
TO LIKELY IN THE EAST WEDNESDAY AFTERNOON TO ACCOUNT FOR THAT
PERIOD OF SEVERE STORMS.
STORMS SHOULD BE WINDING DOWN WED EVENING AS THE COMPLEX MOVES
INTO INDIANA. THURSDAY AND THURSDAY NIGHT SHOULD BE PRIMARILY
DRY...BUT A FEW DAYTIME SHOWERS WILL BE POSSIBLE IN THE EAST AS
THE UPPER WAVE LINGERS ACROSS THE EAST...AND A FEW SHOWERS MAY
REACH OUR SOUTHWESTERN COUNTIES THUR NIGHT AHEAD OF THE NEXT UPPER
LEVEL WAVE. WE KEPT SLIGHT CHANCE POPS EVERYWHERE ON FRIDAY AS
THAT WAVE PROGRESSES ACROSS IL. PRECIP SHOULD BE SPOTTY...AS
COOLER AND LESS HUMID AIR BEGINS TO FLOW INTO THE AREA ON
NORTHWEST WINDS.
LONG TERM...SATURDAY THROUGH TUESDAY.
WE EXPECT TO BE IN AN EXTENDED PERIOD UP UPPER LEVEL TROUGHING AS
A CUT OFF LOW DEVELOPS ACROSS THE WESTERN GREAT LAKES AND
RETROGRADES AND OSCILLATES OVER THE MIDWEST THROUGH EARLY NEXT
WEEK. PERIODS OF SLIGHT CHANCE AND CHANCE POPS WILL PEPPER THE
EXTENDED FORECAST AS A RESULT...DUE TO VARIOUS SHORTWAVE ROTATING
AROUND THE UPPER LOW. RELATIVELY COOL AIR ALOFT WILL ALSO KEEP
LAPSE RATES MODERATELY HIGH...AND FAVORABLE FOR ANY SUNS HEATING
TO CREATE SHOWERS AND ISOLATED STORMS.
TEMPS WILL SETTLE OUT WITH HIGHS IN THE UPPER 70S TO NEAR 80 AND
LOWS IN THE LOWER 60S FOR MUCH OF THE EXTENDED PERIOD.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 7 AM CDT WEDNESDAY FOR ILZ027>031.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
847 PM CDT TUE JUN 25 2013
.MESOSCALE DISCUSSION...
845 PM CDT
MCV MENTIONED IN PREVIOUS UPDATE CONTINUES TO TRACK TO THE EAST-
SOUTHEAST ACROSS THE CWA PER GOES SATELLITE EXTRAPOLATION.
EXPECTATION IS THAT THIS CIRCULATION WILL MOVE OUT OF THE
EAST/SOUTHEAST COUNTIES BY 10 PM CDT. CONVECTION WHICH CONTINUES
TO BUBBLE OVER LAKE MICHIGAN/NORTHWEST INDIANA AND OVER THE SOUTH
END OF THE LAKE WILL LIKELY CONTINUE FOR THE NEXT 1-2 HOURS AS THE
MCV COMPLETES ITS TRANSIT OF THE AREA BEFORE MOVING EAST OF THE
FORECAST AREA. SUBSIDENCE/STABILIZATION IN THE IMMEDIATE WAKE OF
THIS FEATURE WILL LIKELY SUPPRESS NEW DEVELOPMENT ACROSS THE
CENTRAL PART OF THE NRN IL CWA FOR A COUPLE OF HOURS...AND
THEREFORE AFTER COLLABORATION WITH SPC HAVE DECIDED TO REMOVE
LASALLE...KENDALL...GRUNDY AND WILL COUNTIES FROM SEVERE
THUNDERSTORM WATCH 363.
WHILE PREVIOUS CONVECTION HAS STABILIZED LOW LEVELS ACROSS THE
SOUTHERN TIER OF OUR CWA COUNTIES IN 363...INCREASING SOUTHERLY LOW
LEVEL JET AS NOTED IN VWP/S TO OUR WEST/SOUTHWEST HAS RESULTED IN
DEVELOPMENT OF NEW DEEP/STRONG CONVECTION ACROSS WESTERN IL AND
THESE STORMS MAY PERSIST ABOVE COLD POOL AND MAINTAIN A SEVERE
THREAT INTO THE PONTIAC/KANKAKEE AREAS IN ANOTHER 1-2 HOURS.
LOOKING FARTHER WEST...MID-LEVEL SHORT WAVE ACROSS THE MID-MISSOURI
VALLEY WAS NOTED IN GOES VAPOR IMAGERY. LAST VIS IMAGES OF THE
EVENING SHOW ACCAS FIELD OVER WESTERN/CENTRAL IA...WITH 3000-4000
J/KG OF MUCAPE INDICATED PER SPC/RAP MESOANALYSIS. CONVECTION
ALLOWING MODELS INCLUDING WRF-NMM AND HRRR RUNS CONTINUE TO IMPLY
THAT THE IA/WESTERN IL AREA WILL BECOME/REMAIN ACTIVE OVERNIGHT...
WITH ONE OR MORE CLUSTERS OF STORMS POTENTIALLY AFFECTING PARTS OF
THE CWA INTO EARLY WEDNESDAY MORNING. 23Z HRRR RUN SEEMS TO HAVE A
REASONABLE HANDLE ON THIS SCENARIO...WITH ACTIVITY CURRENTLY
DEVELOPING OVER WESTERN/CENTRAL IL PERHAPS AFFECTING OUR SOUTHERN
COUNTIES THROUGH 05-07Z...THEN DEPICTING DEVELOPMENT OVER
CENTRAL/EASTERN IA SPREADING ACROSS NRN IL DURING THE PRE-DAWN HOURS.
HEAVY RAINFALL/SEVERE RISK CONTINUE OVERNIGHT...WITH WARM/MOIST AND
UNSTABLE AIR MASS.
RATZER
&&
SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT...
256 PM CDT
THE ACTIVE WEATHER EXPECTED OVER THE NEXT 24 TO 30 HOURS...INCLUDING
THE SEVERE WEATHER AND FLASH FLOODING THREAT WILL BE THE FOCUS OF
THE SHORT TERM FORECAST.
DUE TO THE INCREASING THREAT FOR PERIODS OF VERY HEAVY RAINFALL IN
SLOW MOVING STORMS TONIGHT INTO WEDNESDAY...I HAVE EXTENDED THE
FLASH FLOOD WATCH FOR THE ENTIRE AREA AND EXTENDED THROUGH
WEDNESDAY.
REGIONAL SATELLITE WATER VAPOR IMAGERY INDICATES AN UPPER LEVEL
DISTURBANCE CURRENTLY MOVING INTO NORTHWESTERN ILLINOIS. AREA VWP
DATA ACROSS EASTERN IOWA AND SOUTHERN WISCONSIN INDICATE THAT THIS
DISTURBANCE IS ASSOCIATED WITH A MID LEVEL SPEED MAX AROUND 50 KT.
THIS IS RESULTING IN AROUND 40 KT OF 0-6 KM SHEAR...PER SPC
MESO-ANALYSIS. THE AIR MASS AHEAD OF THIS FEATURE...ACROSS NORTHERN
ILLINOIS...HAS BECOME INCREASINGLY UNSTABLE OVER THE PAST FEW
HOURS...WITH SURFACE TEMPERATURES IN THE LOW TO MID 80S AND DEW
POINTS IN THE LOWER 70S...ESPECIALLY TO THE SOUTH OF THE SURFACE
BOUNDARY...CURRENTLY IN PLACE ACROSS FAR NORTHERN ILLINOIS.
MODIFYING THE 12 UTC ILX SOUNDING...THIS RESULTS IN AROUND 3500 J/KG
OF MLCAPE WITH LITTLE TO NO CAPE. NOT SURPRISING...THAT
THUNDERSTORMS ARE BEGINNING TO FIRE ACROSS PORTIONS OF CENTRAL
ILLINOIS AS ASCENT CONTINUES TO OVERSPREAD THIS UNSTABLE
ENVIRONMENT. I EXPECT THIS TREND TO CONTINUE...ESPECIALLY ACROSS
SOUTHERN SECTIONS OF THE AREA...WITH THE POTENTIAL OF AN
ORGANIZING FORWARD PROPAGATING CONVECTIVE COMPLEX WITH STRONG
DAMAGING WINDS BEING THE MAIN THREAT. HOWEVER...THE THREAT FOR
SEVERE HAIL WILL ALSO BE A CONCERN...ESPECIALLY EARLY IN THE EVENT.
THIS ACTIVITY WILL LIKELY CONTINUE INTO THE EARLY EVENING.
ADDITIONAL ROUNDS OF CONVECTION ARE LIKELY AGAIN THIS EVENING AND
OVERNIGHT...WITH THE POTENTIAL FOR SLOW MOVING AND BACK BUILDING
THUNDERSTORMS. THE QUASI-ZONAL FLOW PATTERN ACROSS THE CONUS IS IN
THE PROCESS OF AMPLIFYING...IN RESPONSE TO AN UPPER LOW OVER THE
EASTERN PACIFIC. ULTIMATELY THIS WILL SET THE STAGE FOR A BUILDING
MID/UPPER LEVEL RIDGE ACROSS THE WESTERN CONUS AND FALLING HEIGHTS
ACROSS THE GREAT LAKES REGION. THIS PROCESS SHOULD ALLOW
ANOTHER...STRONGER SHORT WAVE...CURRENTLY NOTED IN THE WATER VAPOR
IMAGERY ACROSS THE PLAINS...TO MOVE ACROSS THE AREA BY WEDNESDAY. A
SOUTHWESTERLY LOW LEVEL JET WILL KICK UP AHEAD OF THIS FEATURE
DURING THE EVENING...AND GUIDANCE CONTINUES TO PLACE THE NOSE OF THIS
LOW LEVEL JET RIGHT ACROSS THE AREA TONIGHT. THIS COULD POTENTIALLY
LEAD TO A DECENT FLASH FLOODING EVENT FOR PORTIONS OF THE AREA
TONIGHT INTO WEDNESDAY...WITH A GOOD POTENTIAL FOR SLOW MOVING AND
BACK BUILDING THUNDERSTORMS. CORFIDI VECTORS ARE PROGGED TO BE 5
KT OR LESS TONIGHT AS THE JET VEERS WEST-SOUTHWESTERLY AND OFFSETS
THE CLOUD BEARING FLOW. CONSIDERING THIS...AND THE FACT THAT FLASH
FLOOD GUIDANCE REMAINS LOW ACROSS THE AREA...I DECIDED TO GO
WITH A FLASH FLOOD WATCH FOR THE ENTIRE AREA.
IT APPEARS THESE STORMS WITH HEAVY RAIN WILL CONTINUE INTO THE EARLY
MORNING HOURS ON WEDNESDAY AND THEN INTENSIFY IN STRENGTH BY THE
AFTERNOON...ESPECIALLY ACROSS MY SOUTHERN AND EASTERN AREAS. THIS
COULD ALSO LEAD TO ADDITIONAL SEVERE STORMS...ESPECIALLY SOUTH. IT
IS POSSIBLY THAT THE MORNING ACTIVITY COULD LIMIT THE SEVERE RISK TO
THE NORTH.
KJB
LONG TERM...THURSDAY THROUGH TUESDAY...
350 PM CDT
AMPLIFICATION OF THE WESTERN CONUS RIDGE AND EASTERN TROUGH WILL
BEGIN TO INFLUENCE THE LOCAL AREA BY LATE WEDNESDAY INTO THURSDAY
AFTER A SURFACE TROUGH PUSHES THROUGH THE AREA AND WINDS AT ALL
LEVELS TURN TO THE NORTHWEST. LOW LEVEL WARMTH AND HUMIDITY DO NOT
REALLY DEPART UNTIL FRIDAY WHEN THE EXPANDING EASTERN TROUGH PUSHES
THE UPPER JET SOUTH OF THE AREA AND USHERS IN DRIER AND MILDER AIR.
ON BOTH THURSDAY AND FRIDAY IT WOULD NOT TAKE MUCH OF A WRINKLE IN
THE UPPER FLOW TO SUPPORT AN AFTERNOON SHOWER...SO SLIGHT CHANCE
POPS HAVE BEEN MAINTAINED ON BOTH DAYS. BY THE WEEKEND THE
CONVECTIVE INSTABILITY APPEARS TO HAVE DECREASED...BUT THE PRESENCE
OF BOTH A SURFACE AND UPPER LEVEL TROUGH DROPPING SOUTH ACROSS THE
AREA WILL STILL SUPPORT LARGE SCALE LIFT...PRIMARILY TO THE SOUTH ON
SUNDAY. PRECIP CHANCES FINALLY DECREASE BY EARLY NEXT WEEK AS THE
SURFACE AND UPPER SUPPORT DIMINISH...BUT UNSEASONABLY COOL AIR
REMAINS IN PLACE WITH CONTINUED NORTH TO NORTHEASTERLY WINDS.
LENNING
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* TIMING AND LOCATION OF ADDITIONAL DEVELOPMENT OF TSRA THAT WILL
AFFECT THE TERMINALS THROUGH THE EVENING.
* LAKE BREEZE STALLING OUT NEAR ORD AND MIDWAY 00Z-01Z AND THEN
WASHING OUT AS SOUTHWESTERLY FLOW REESTABLISHES ITSELF.
* ADDITIONAL ROUNDS OF TSRA POSSIBLE THROUGH THE OVERNIGHT AND
AGAIN WEDNESDAY.
ED F
//DISCUSSION...UPDATED 00Z...
WEAK SURFACE FRONTAL BOUNDARY REMAINS DRAPED WEST-EAST ACROSS
THE AREA ROUGHLY JUST SOUTH OF AND PARALLEL TO THE IL-WI STATE
LINE. THIS BOUNDARY ALONG WITH SEVERAL OUTFLOW BOUNDARIES REMAIN
POSSIBLE FOCUSING MECHANISMS FOR ADDITIONAL THUNDERSTORM
DEVELOPMENT THIS EVENING. ATMOSPHERIC ASCENT MAY ALSO BE ENHANCED
BY AN UPPER LEVEL DISTURBANCE ROTATING ACROSS NRN IL THIS EVENING.
LOW LEVEL INFLOW ALSO EXPECTED TO INCREASE OVERNIGHT.
WEAK LAKE BREEZE EVIDENT ON ORD TERMINAL RADAR HAS SLOWED
TREMENDOUSLY AND NEARLY STALLED JUST EAST OF ORD AND MDW AT 00Z.
MAY SEE BOUNDARY INCH SOMEWHAT CLOSER AND WINDS FLOP OVER TO NNE FOR
A BRIEF PERIOD OR GO VARIABLE... BEFORE SOUTHWESTERLY FLOW
REESTABLISHES ITSELF LATER THIS EVENING.
ED F
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* MEDIUM-HIGH CONFIDENCE IN ADDITIONAL SHRA/TSRA DEVELOPING THIS
EVENING...LOW TO MEDIUM CONFIDENCE IN TIMING AND COVERAGE
INITIALLY.
* MEDIUM CONFIDENCE IN GENERAL WIND TRENDS INCLUDING LAKE BREEZE.
* LOW CONFIDENCE IN BEST TIMING AND DURATION FOR TSRA POTENTIAL ON
WEDNESDAY...BUT MEDIUM CONFIDENCE THAT ADDITIONAL ACTIVITY WILL
OCCUR.
ED F
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY AND FRIDAY...GENERALLY VFR OUTSIDE OF COUPLE OF BRIEF PERIODS
OF THUNDERSTORMS.
SATURDAY THROUGH MONDAY...GENERALLY VFR. A COUPLE OF BRIEF PERIODS
OF SHOWERS.
ED F
&&
.MARINE...
234 PM CDT
A LARGE RIDGE OF HIGH PRESSURE WILL PERSIST ACROSS THE SOUTHEAST
STATES THROUGH MID WEEK WHILE A TROUGH OF LOW PRESSURE OVER THE
CENTRAL PLAINS SHIFTS INTO THE UPPER MISSOURI VALLEY THIS EVENING
AND THE UPPER MISSISSIPPI VALLEY WEDNESDAY. THIS WILL KEEP
GENERALLY SOUTHERLY WINDS OVER THE LAKE THROUGH WEDNESDAY. THE
TROUGH WILL THEN DRIFT ACROSS LAKE MICHIGAN WEDNESDAY
EVENING...WITH WINDS GRADUALLY SHIFTING TO MORE NORTHERLY. THE
SOUTHERN END OF THE TROUGH WILL CLOSE OFF INTO A CLOSED LOW OVER
THE EASTERN GREAT LAKES THURSDAY AFTERNOON AND TRACK NORTH INTO
SOUTHERN QUEBEC BY FRIDAY NIGHT. A SECONDARY SURGE OF COOLER AIR
WILL PUSH ACROSS THE LAKE INCREASING WINDS TO 15 TO 20 KT.
NORTHERLY WINDS OF 10 TO 15 KT WILL PERSIST OVER THE LAKE THROUGH
THE END OF THE PERIOD.
KREIN
&&
.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 WEDNESDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 7
PM WEDNESDAY.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
659 PM CDT TUE JUN 25 2013
.DISCUSSION...
ISSUED 300 PM CDT TUE JUN 25 2013
SEVERE STORM CHANCES WILL REMAIN THE FOCUS OVER THE NEXT 2 DAYS.
FLASH FLOODING POTENTIAL TONIGHT IN THE NORTH WILL ALSO BE A
CONCERN. BEYOND THAT...AN AIRMASS CHANGE IS PROJECTED FOR LATE
THIS WEEK AND WEEKEND. HOWEVER...A CUTOFF UPPER LOW LINGERING OVER
THE HEARTLAND WILL KEEP SHOWERS AND EVEN ISOLATED THUNDERSTORMS IN
THE FORECAST THROUGH EARLY NEXT WEEK.
SHORT TERM...TONIGHT THROUGH FRIDAY.
WE DECIDED TO PUT OUR 5 NORTHERN COUNTIES IN A FLASH FLOOD THROUGH
TONIGHT DUE TO PREVIOUS 3-5 INCH RAINS EARLY MONDAY MORNING AND
THE POTENTIAL FOR ADDITIONAL VERY HEAVY RAINFALL RATES UP TO 2
INCHES AN HOUR WITH ANY THUNDERSTORMS THROUGH TONIGHT. PWATS
REMAIN IN THE 1.7-1.9" RANGE...AND PERIODIC STORMS IN AN EAST-WEST
LINE ACROSS N IL IS POSSIBLE.
ADJUSTING OUR 12Z SOUNDING FOR CURRENT CONDITIONS SHOWS ML-CAPE
VALUES APPROACHING 3500 J/KG ACROSS OUR AREA...WITH LITTLE TO NO
CIN. VARIOUS BOUNDARIES ACROSS THE AREA FROM YESTERDAYS CONVECTION
HAVE ALREADY BEGUN TO FIRE BETWEEN 18-19Z. WATER VAPOR PIX CONFIRM
A SHORTWAVE IN THE FLOW ACROSS IOWA PROGRESSING EAST-NE. THAT WAVE
SHOULD HELP RAMP UP THE COVERAGE OF STORMS AND POSSIBLY PUSH US
INTO SEVERE WEATHER MODE. FREEZING LEVEL AT 14.4K FT MEANS HAIL
WILL NEED INTENSE UPDRAFTS TO REACH SEVERE LEVELS /1"+/...BUT WE HAVE
THE CAPE TO ACCOMPLISH THAT WITH THE STRONGEST STORMS. WIND SHEAR
WILL BE GRADUALLY INCREASING AS WE HEAD INTO THIS EVENING...SO
ROTATING SUPERCELLS WILL BE POSSIBLE AS THE EVENT PROGRESSES.
THE LATEST HRRR IS INDICATING TWO PERIODS OF STORMS POSSIBLE. WE
EXPECT A WAVE OF STORMS THIS EVENING THAT MAY BE FOLLOWED BY
ANOTHER BOWING COMPLEX OF STORMS ROLLING INTO OUR AREA FROM IOWA
REACHING KNOX COUNTY AROUND 06Z/1AM. THOSE STORMS MAY BE STILL
AFFECTING OUR COUNTIES SE OF I-70 WED MORNING BEFORE THEY DEPART
INTO INDIANA. WE WENT WITH SOME LIKELY POPS IN THE MORNING TO
ACCOUNT FOR THAT.
THEN A BREAK IN THE ACTION MAY DEVELOP THE REST OF WED MORNING AS
THE ATMOSPHERE RECHARGES FOR THE AFTERNOON WAVE OF STRONG TO
SEVERE STORMS. IT APPEARS THAT A LINE OF STORMS WILL DEVELOP
ACROSS WEST CENTRAL ILLINOIS BY MID AFTERNOON...THEN PROGRESS
EASTWARD. AN INCREASING LLJ IS EXPECTED TO COINCIDE WITH UPPER
LEVEL WINDS VEERING TO THE NORTHWEST. THAT WILL INCREASE SHEAR AND
HELICITY PARAMETERS AND RAMP UP THE THREAT OF ROTATING STORMS AND
POSSIBLY A FEW TORNADOES...MAINLY EAST OF I-55. WE INCREASED POPS
TO LIKELY IN THE EAST WEDNESDAY AFTERNOON TO ACCOUNT FOR THAT
PERIOD OF SEVERE STORMS.
STORMS SHOULD BE WINDING DOWN WED EVENING AS THE COMPLEX MOVES
INTO INDIANA. THURSDAY AND THURSDAY NIGHT SHOULD BE PRIMARILY
DRY...BUT A FEW DAYTIME SHOWERS WILL BE POSSIBLE IN THE EAST AS
THE UPPER WAVE LINGERS ACROSS THE EAST...AND A FEW SHOWERS MAY
REACH OUR SOUTHWESTERN COUNTIES THUR NIGHT AHEAD OF THE NEXT UPPER
LEVEL WAVE. WE KEPT SLIGHT CHANCE POPS EVERYWHERE ON FRIDAY AS
THAT WAVE PROGRESSES ACROSS IL. PRECIP SHOULD BE SPOTTY...AS
COOLER AND LESS HUMID AIR BEGINS TO FLOW INTO THE AREA ON
NORTHWEST WINDS.
LONG TERM...SATURDAY THROUGH TUESDAY.
WE EXPECT TO BE IN AN EXTENDED PERIOD UP UPPER LEVEL TROUGHING AS
A CUT OFF LOW DEVELOPS ACROSS THE WESTERN GREAT LAKES AND
RETROGRADES AND OSCILLATES OVER THE MIDWEST THROUGH EARLY NEXT
WEEK. PERIODS OF SLIGHT CHANCE AND CHANCE POPS WILL PEPPER THE
EXTENDED FORECAST AS A RESULT...DUE TO VARIOUS SHORTWAVE ROTATING
AROUND THE UPPER LOW. RELATIVELY COOL AIR ALOFT WILL ALSO KEEP
LAPSE RATES MODERATELY HIGH...AND FAVORABLE FOR ANY SUNS HEATING
TO CREATE SHOWERS AND ISOLATED STORMS.
TEMPS WILL SETTLE OUT WITH HIGHS IN THE UPPER 70S TO NEAR 80 AND
LOWS IN THE LOWER 60S FOR MUCH OF THE EXTENDED PERIOD.
&&
.AVIATION...
ISSUED 659 PM CDT TUE JUN 25 2013
LINE OF CONVECTION CURRENTLY STRETCHES FROM NEAR KDNV TO
KTAZ...JUST SOUTH OF THE I-72 TERMINALS. WINDS IMMEDIATELY BEHIND
THE LINE WILL VEER TO THE N/NE FOR A COUPLE OF HOURS BEFORE
GRADUALLY RETURNING TO A MORE SOUTHERLY DIRECTION AFTER 02-03Z.
LATEST SATELLITE/RADAR MOSAIC SHOWS WIDELY SCATTERED STORMS
DEVELOPING FURTHER WEST ACROSS WEST-CENTRAL ILLINOIS INTO
IOWA...HOWEVER THESE CELLS SHOULD DISSIPATE AS THEY TRACK EASTWARD
INTO A MORE STABLE ENVIRONMENT ALONG/EAST OF I-55. WILL CARRY VCTS
AT THE TAF SITES THROUGH MID-EVENING ACCORDINGLY. MAIN EMPHASIS
WILL THEN SHIFT TO THE OVERNIGHT HOURS...AS HRRR SUGGESTS ANOTHER
COMPLEX OF STORMS DEVELOPING ACROSS IOWA THEN TRACKING E/SE INTO
CENTRAL ILLINOIS TOWARD DAWN. WILL CARRY PREDOMINANT THUNDER AFTER
10Z AT KPIA...THEN AFTER 12Z FURTHER EAST AT KDEC. AFTER A 3-4
HOUR PERIOD OF CONVECTION WEDNESDAY MORNING...A LULL IN THE
ACTIVITY MAY DEVELOP. DUE TO UNCERTAINTY...WILL ONLY MENTION VCTS
FROM MID MORNING THROUGH MID-AFTERNOON WHEN COLD FRONT PUSHES
THROUGH THE AREA AND SHIFTS BETTER STORM CHANCES FURTHER EAST INTO
INDIANA. WINDS WILL BE SOUTHERLY AT LESS THAN 10KT TONIGHT...THEN
WILL BECOME WESTERLY BY WEDNESDAY AFTERNOON.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH WEDNESDAY MORNING FOR ILZ027>031.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
516 PM CDT MON JUN 24 2013
.MESOSCALE DISCUSSION...
505 PM CDT
THE MOST FOCUS REMAINS ALONG THE I-88 CORRIDOR AND NORTH AND SOUTH
OF THAT BY AROUND 30 MILES. THE APEX IS MOVING AT A FORWARD SPEED
OF 60+ MPH AND THE MESO-VORTICY NEAR THE DEKALB/LASALLE BORDER HAS
A FAIRLY LONG HISTORY...AFTER WEAKENING SOME FROM BUREAU COUNTY
AND NOW HAS RE-INTENSIFIED. THIS CONTINUES TO BE VERY CLOSE TO A
WEST-TO-EAST BOUNDARY PER EARLIER VISIBLE SATELLITE. 0-3 KM CAPE
FROM SPC RAP OBJECTIVE ANALYSIS HAS VALUES AT 150-175 J/KG...SO
CERTAINLY FAVORABLE FOR STRETCHING ALONG THIS. STILL...THE PRIMARY
WIDESPREAD THREAT REMAINS DAMAGING WINDS PER RADAR AND
ENVIRONMENTAL SIGNATURES.
ON THE LARGE SCALE RADAR AND SATELLITE THIS FORWARD-PROPAGATING MCS
LOOKS VERY WELL-ORGANIZED. THE ENVIRONMENT CONTINUES TO BE
FAVORABLE FOR SUSTAINABILITY...WITH DEEP CAPE AT OR IN EXCESS OF
3000 J/KG...STEEP LOW-LEVEL LAPSE RATES AND ASSOCIATED THETA-E
DIFFERENCE...AND STRONG 0-1 AND 0-3 KM SHEAR ADVECTING EAST WITHIN
THE MCS FOR COLD POOL SUSTAINABILITY.
MTF
.DISCUSSION...
327 PM CDT
SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT...
A VERY ACTIVE PERIOD OF WEATHER IS EXPECTED...AT LEAST FOR PORTIONS
OF THE AREA...THROUGH WEDNESDAY. THIS INCLUDES A FEW PERIODS OF
SEVERE THUNDERSTORMS AND ALSO A GOOD THREAT FOR VERY HEAVY RAINFALL
AND POSSIBLE FLASH FLOODING. AS SUCH...THIS WILL BE THE FOCUS OF THE
FORECAST.
WE HAVE EXTENDED THE FLASH FLOOD WATCH FOR OUR WESTERN COUNTIES
THROUGH TONIGHT.
TEMPERATURES ACROSS NORTHERN ILLINOIS AND NW INDIANA HAVE JUMPED
INTO THE LOW TO MID 80S OVER THE PAST COUPLE HOURS AFTER THE MORNING
CLOUD COVER CLEARED. WITH DEW POINTS NEAR 70...THIS IS RESULTING IN
MLCAPES AROUND 2,000 J/KG ACROSS THE AREA...PER SPC MESOANALYSIS
PAGE. IN ADDITION...IT APPEARS THAT THE 0-6 KM SHEAR MAY END UP A
BIT STRONGER THAN PREVIOUSLY THOUGHT. VWP DATA INDICATES THAT A SPEED
MAX AROUND 50 KT ...ASSOCIATED WITH A MID LEVEL DISTURBANCE MOVING
INTO NORTHWESTERN IOWA...IS PUNCHING EASTWARD ACROSS IOWA. THUS IT
APPEARS THAT 40 KT OF DEEP LAYER SHEER MAY OVERSPREAD THIS AREA
LATER THIS AFTERNOON AND EVENING AS THIS SPEED MAX SHIFTS EASTWARD.
CURRENT THOUGHTS ARE THAT THE LINE OF CONVECTION TO THE WEST WILL
POSE A SEVERE THREAT FOR MOST OF THE AREA INTO THE EARLY EVENING
HOURS. STRONG DAMAGING WINDS...POSSIBLY IN EXCESS OF 80 MPH...WILL
BE THE PRIMARY THREAT ALONG WITH A SMALL POTENTIAL OF SOME
MARGINALLY SEVERE HAIL.
IT APPEARS THE MAIN FOCUS FOR CONVECTION MAY SHIFT NORTH INTO
WISCONSIN LATER TONIGHT AS THE LOW LEVEL JET FOCUSES FARTHER NORTH.
HOWEVER...THIS APPEARS TO BE SHORTED LIVED...AS CONVECTIVE CHANCES
WILL RETURN ON TUESDAY. IT APPEARS THAT ADDITIONAL PERTURBATIONS IN
THE MEAN QUASI-ZONAL MID LEVEL FLOW...WILL INTERACT WITH THE VERY
MOIST AND UNSTABLE ATMOSPHERE ACROSS THE AREA. IT APPEARS THE CAP
WILL REMAIN FAIRLY WEAK DURING THE DAY...SO IT APPEARS THAT AT LEAST
SOME WIDELY SCATTERED CONVECTION MAY OCCUR...MAINLY ACROSS FAR
NORTHERN ILLINOIS. THIS ACTIVITY COULD AGAIN POSS A SEVERE RISK
ACROSS NORTHERN ILLINOIS WITH STEEP MID LEVEL LAPSE RATES HELPING
PRODUCE MLCAPES IN EXCESS OF 3000 J/KG.
TUESDAY CONVECTION LOOKS LIKE IT WILL BECOME MORE NUMEROUS TUESDAY
EVENING/NIGHT. THE QUASI-ZONAL FLOW PATTERN ACROSS THE CONUS IS
EXPECTED TO BEGIN AMPLIFYING...IN RESPONSE TO AN UPPER LOW OVER THE
EASTERN PACIFIC. ULTIMATELY THIS WILL SET THE STAGE FROM A BUILDING
MID/UPPER LEVEL RIDGE ACROSS THE WESTERN CONUS AND FALLING HEIGHTS
ACROSS THE GREAT LAKES REGION. THIS PROCESS SHOULD ALLOW
ANOTHER...STRONGER...SHORT WAVE TO MOVE ACROSS THE AREA ON
WEDNESDAY. IT APPEARS THIS FEATURE WILL FOCUS THE NOSE OF A 40 KT
LOW LEVEL JET RIGHT ACROSS SOUTHERN WISCONSIN AND NORTHERN ILLINOIS
TUESDAY NIGHT INTO WEDNESDAY. THIS COULD SET THE STAGE FOR VERY HEAVY
RAINFALL ACROSS PORTIONS OF NORTHERN ILLINOIS INTO WEDNESDAY. THIS
LOOKS TO BE THE PERIOD TO REALLY WATCH FOR POSSIBLE FLOODING ACROSS
THE AREA. PWATS ARE PROGGED TO REACH NEARLY 2.00 INCHES...WHICH IS
AROUND THE 99 PERCENTILE. IN ADDITION...THE SOUTHWESTERLY ORIENTATION
OF THE LOW LEVEL JET COULD OFFSET THE MEAN CLOUD BEARING
FLOW...POSSIBLY RESULTING IN SLOW MOVING OR BACK BUILDING SEGMENTS
TUESDAY NIGHT. HOWEVER...CONFIDENCE IN THE EXACT PLACEMENT OF THE
HEAVIEST RAIN REMAINS IN QUESTION AT THIS TIME...BUT GUIDANCE IS
HINTING THAT NORTHERN ILLINOIS COULD LIE IN THE FAVORED ZONE. THIS
WILL HAVE TO BE WATCHED...WITH THE POSSIBLY OF A FLASH FLOOD WATCH
NEEDED FOR PORTIONS OF NORTHERN ILLINOIS AND NORTHWESTERN INDIANA
DURING THIS PERIOD.
THE SEVERE CONVECTIVE THREAT SHOULD BEGIN TO WANE WEDNESDAY
EVENING AS THE MID LEVEL DISTURBANCE SHIFT EAST OF THE AREA.
TEMPERATURES LOOK TO CONTINUE TO BE PROBLEMATIC FOR THE NEXT COUPLE
OF DAYS...WITH ADDITIONAL BUST POTENTIAL WITH CONVECTIVE ACTIVITY.
HOWEVER...I ONLY MADE MINOR CHANCES TO THE GOING TEMP
FORECAST...MAINLY TO COOL THE NORTHERN AREAS BY A COUPLE DEGREES.
KJB
EXTENDED FORECAST...THURSDAY THROUGH MONDAY...
QUASI ZONAL FLOW IN THE SOUTHERN STREAM EARLY IN THE WEEK WILL
TRANSITION BY THE SECOND HALF OF THE WEEK TO AN INCREASINGLY
AMPLIFIED BROAD WESTERN CONUS RIDGE AND ITS CORRESPONDING LONGWAVE
TROUGH OVER THE EASTERN CONUS. THIS WOULD PUT THE LOCAL AREA IN
NORTHWEST UPPER FLOW EARLY IN THE WEEKEND...AND THEN UNDER AN UPPER
LOW PUSHING SOUTHWEST ACROSS THE GREAT LAKES BY SUNDAY. THE MOST
OBVIOUS RAMIFICATION WILL BE MUCH COOLER HIGHS...ESPECIALLY FOR THE
WEEKEND AND EARLY NEXT WEEK. IN ADDITION...GFS/ECMWF ARE SUGGESTING
THE POSSIBILITY OF THUNDERSTORMS TRIGGERED BY SHORTWAVE ENERGY
DROPPING ACROSS THE AREA INTO THE BASE OF THE EASTERN TROUGH
THURSDAY AND FRIDAY...WHEN CONSIDERABLE LOW LEVEL MOISTURE REMAINS
IN PLACE OVER THE AREA. DEWPOINTS FALL ALONG WITH THE TEMPERATURES
BY THE WEEKEND...BUT THE DEEPENING UPPER LOW ALSO SUPPORTS A
CONTINUED CHANCE OF SHOWERS INTO MONDAY.
EML
&&
.DISCUSSION...
327 PM CDT
SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT...
A VERY ACTIVE PERIOD OF WEATHER IS EXPECTED...AT LEAST FOR PORTIONS
OF THE AREA...THROUGH WEDNESDAY. THIS INCLUDES A FEW PERIODS OF
SEVERE THUNDERSTORMS AND ALSO A GOOD THREAT FOR VERY HEAVY RAINFALL
AND POSSIBLE FLASH FLOODING. AS SUCH...THIS WILL BE THE FOCUS OF THE
FORECAST.
WE HAVE EXTENDED THE FLASH FLOOD WATCH FOR OUR WESTERN COUNTIES
THROUGH TONIGHT.
TEMPERATURES ACROSS NORTHERN ILLINOIS AND NW INDIANA HAVE JUMPED
INTO THE LOW TO MID 80S OVER THE PAST COUPLE HOURS AFTER THE MORNING
CLOUD COVER CLEARED. WITH DEW POINTS NEAR 70...THIS IS RESULTING IN
MLCAPES AROUND 2,000 J/KG ACROSS THE AREA...PER SPC MESOANALYSIS
PAGE. IN ADDITION...IT APPEARS THAT THE 0-6 KM SHEAR MAY END UP A
BIT STRONGER THAN PREVIOUSLY THOUGHT. VWP DATA INDICATES THAT A SPEED
MAX AROUND 50 KT ...ASSOCIATED WITH A MID LEVEL DISTURBANCE MOVING
INTO NORTHWESTERN IOWA...IS PUNCHING EASTWARD ACROSS IOWA. THUS IT
APPEARS THAT 40 KT OF DEEP LAYER SHEER MAY OVERSPREAD THIS AREA
LATER THIS AFTERNOON AND EVENING AS THIS SPEED MAX SHIFTS EASTWARD.
CURRENT THOUGHTS ARE THAT THE LINE OF CONVECTION TO THE WEST WILL
POSE A SEVERE THREAT FOR MOST OF THE AREA INTO THE EARLY EVENING
HOURS. STRONG DAMAGING WINDS...POSSIBLY IN EXCESS OF 80 MPH...WILL
BE THE PRIMARY THREAT ALONG WITH A SMALL POTENTIAL OF SOME
MARGINALLY SEVERE HAIL.
IT APPEARS THE MAIN FOCUS FOR CONVECTION MAY SHIFT NORTH INTO
WISCONSIN LATER TONIGHT AS THE LOW LEVEL JET FOCUSES FARTHER NORTH.
HOWEVER...THIS APPEARS TO BE SHORTED LIVED...AS CONVECTIVE CHANCES
WILL RETURN ON TUESDAY. IT APPEARS THAT ADDITIONAL PERTURBATIONS IN
THE MEAN QUASI-ZONAL MID LEVEL FLOW...WILL INTERACT WITH THE VERY
MOIST AND UNSTABLE ATMOSPHERE ACROSS THE AREA. IT APPEARS THE CAP
WILL REMAIN FAIRLY WEAK DURING THE DAY...SO IT APPEARS THAT AT LEAST
SOME WIDELY SCATTERED CONVECTION MAY OCCUR...MAINLY ACROSS FAR
NORTHERN ILLINOIS. THIS ACTIVITY COULD AGAIN POSS A SEVERE RISK
ACROSS NORTHERN ILLINOIS WITH STEEP MID LEVEL LAPSE RATES HELPING
PRODUCE MLCAPES IN EXCESS OF 3000 J/KG.
TUESDAY CONVECTION LOOKS LIKE IT WILL BECOME MORE NUMEROUS TUESDAY
EVENING/NIGHT. THE QUASI-ZONAL FLOW PATTERN ACROSS THE CONUS IS
EXPECTED TO BEGIN AMPLIFYING...IN RESPONSE TO AN UPPER LOW OVER THE
EASTERN PACIFIC. ULTIMATELY THIS WILL SET THE STAGE FROM A BUILDING
MID/UPPER LEVEL RIDGE ACROSS THE WESTERN CONUS AND FALLING HEIGHTS
ACROSS THE GREAT LAKES REGION. THIS PROCESS SHOULD ALLOW
ANOTHER...STRONGER...SHORT WAVE TO MOVE ACROSS THE AREA ON
WEDNESDAY. IT APPEARS THIS FEATURE WILL FOCUS THE NOSE OF A 40 KT
LOW LEVEL JET RIGHT ACROSS SOUTHERN WISCONSIN AND NORTHERN ILLINOIS
TUESDAY NIGHT INTO WEDNESDAY. THIS COULD SET THE STAGE FOR VERY HEAVY
RAINFALL ACROSS PORTIONS OF NORTHERN ILLINOIS INTO WEDNESDAY. THIS
LOOKS TO BE THE PERIOD TO REALLY WATCH FOR POSSIBLE FLOODING ACROSS
THE AREA. PWATS ARE PROGGED TO REACH NEARLY 2.00 INCHES...WHICH IS
AROUND THE 99 PERCENTILE. IN ADDITION...THE SOUTHWESTERLY ORIENTATION
OF THE LOW LEVEL JET COULD OFFSET THE MEAN CLOUD BEARING
FLOW...POSSIBLY RESULTING IN SLOW MOVING OR BACK BUILDING SEGMENTS
TUESDAY NIGHT. HOWEVER...CONFIDENCE IN THE EXACT PLACEMENT OF THE
HEAVIEST RAIN REMAINS IN QUESTION AT THIS TIME...BUT GUIDANCE IS
HINTING THAT NORTHERN ILLINOIS COULD LIE IN THE FAVORED ZONE. THIS
WILL HAVE TO BE WATCHED...WITH THE POSSIBLY OF A FLASH FLOOD WATCH
NEEDED FOR PORTIONS OF NORTHERN ILLINOIS AND NORTHWESTERN INDIANA
DURING THIS PERIOD.
THE SEVERE CONVECTIVE THREAT SHOULD BEGIN TO WANE WEDNESDAY
EVENING AS THE MID LEVEL DISTURBANCE SHIFT EAST OF THE AREA.
TEMPERATURES LOOK TO CONTINUE TO BE PROBLEMATIC FOR THE NEXT COUPLE
OF DAYS...WITH ADDITIONAL BUST POTENTIAL WITH CONVECTIVE ACTIVITY.
HOWEVER...I ONLY MADE MINOR CHANCES TO THE GOING TEMP
FORECAST...MAINLY TO COOL THE NORTHERN AREAS BY A COUPLE DEGREES.
KJB
EXTENDED FORECAST...THURSDAY THROUGH MONDAY...
QUASI ZONAL FLOW IN THE SOUTHERN STREAM EARLY IN THE WEEK WILL
TRANSITION BY THE SECOND HALF OF THE WEEK TO AN INCREASINGLY
AMPLIFIED BROAD WESTERN CONUS RIDGE AND ITS CORRESPONDING LONGWAVE
TROUGH OVER THE EASTERN CONUS. THIS WOULD PUT THE LOCAL AREA IN
NORTHWEST UPPER FLOW EARLY IN THE WEEKEND...AND THEN UNDER AN UPPER
LOW PUSHING SOUTHWEST ACROSS THE GREAT LAKES BY SUNDAY. THE MOST
OBVIOUS RAMIFICATION WILL BE MUCH COOLER HIGHS...ESPECIALLY FOR THE
WEEKEND AND EARLY NEXT WEEK. IN ADDITION...GFS/ECMWF ARE SUGGESTING
THE POSSIBILITY OF THUNDERSTORMS TRIGGERED BY SHORTWAVE ENERGY
DROPPING ACROSS THE AREA INTO THE BASE OF THE EASTERN TROUGH
THURSDAY AND FRIDAY...WHEN CONSIDERABLE LOW LEVEL MOISTURE REMAINS
IN PLACE OVER THE AREA. DEWPOINTS FALL ALONG WITH THE TEMPERATURES
BY THE WEEKEND...BUT THE DEEPENING UPPER LOW ALSO SUPPORTS A
CONTINUED CHANCE OF SHOWERS INTO MONDAY.
EML
&&
.HYDROLOGY...
433 PM CDT
A SHORT PERIOD OF HEAVY RAINFALL WILL ACCOMPANY THE LINE OF STORMS
CURRENTLY APPROACHING NORTH CENTRAL ILLINOIS. THIS COULD RESULT IN
SOME MINOR FLOODING...ESPECIALLY IN AREAS THAT WERE HIT WITH 1 TO 2
INCHES OF RAINFALL THIS MORNING. HOWEVER...ADDITIONAL PERIODS OF
HEAVY RAINFALL ARE EXPECTED LATE TUESDAY INTO WEDNESDAY. DURING THIS
PERIOD PRECIPITABLE WATER VALUES COULD BE AROUND 2 INCHES...WHICH
IS AROUND THE 99TH PERCENTILE. ANOTHER DECENT MID LEVEL DISTURBANCE
IS EXPECTED TO APPROACH THE AREA TUESDAY NIGHT AND INTO
WEDNESDAY...AND THIS SYSTEM LOOKS TO INDUCE A SOUTHWESTERLY LOW
LEVEL JET...THAT COULD OFFSET THE FORWARD STORM MOTION...RESULTING
IN SLOW MOVING OR BACK BUILDING THUNDERSTORMS TUESDAY NIGHT INTO
WEDNESDAY. AT THIS TIME...UNCERTAINTY REMAINS AS TO WHERE EXACTLY
THE HEAVIEST RAIN WILL FALL...BUT GUIDANCE CONTINUES TO HINT AT
NORTHERN ILLINOIS AND NORTHWESTERN INDIANA. THIS WILL HAVE TO BE
WATCHED FOR POSSIBILITY OF A FLASH FLOOD WATCH FOR MOST OF THE
AREA AS RAINFALL AMOUNTS IN EXCESS OF 2 INCHES IS CERTAINLY
POSSIBLE ACROSS PORTIONS OF THE AREA.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* SQUALL LINE/BOW ECHO TO IMPACT ORD/MDW AT 23Z
* POTENTIAL FOR DAMAGING WIND GUSTS OF 60-75 KTS
* VSBY REDUCED LESS THAN 1 MILE IN TORRENTIAL RAIN LASTING 15-25 MIN
* STRONGEST WINDS LASTING 5 TO 10 MIN
* PSBL FOG DEVELOPMENT OVERNIGHT INTO EARLY TUE.
ED F
//DISCUSSION...UPDATED 18Z...
WARM AND HUMID CONDITIONS IN PLACE ALONG WITH VARIOUS BOUNDARIES TO
KEEP NEXT ROUND OF SHRA/TSRA IN THE FORECAST INTO THIS EVENING.
ATMOSPHERE TO CONTINUE TO RECOVER FROM MORNING CONVECTIVE ACTIVITY.
THINKING IS A FEW TSRA ARE POSSIBLE BY MID AFTERNOON IN AREAS OF
LESSENING/THINNING OF CLOUD COVER AND MAY EXPAND IN COVERAGE BY LATE
AFTERNOON IF MORE WIDESPREAD SUNSHINE OCCURS. CIRROSTRATUS SHIELD
ASSOCIATED WITH ORGANIZED AREAS OF TSRA/SHRA OVER IA MAY LIMIT
AMOUNT/DURATION OF SUN. TSRA CLUSTERS OVER IA EXPECTED TO ORGANIZE
FURTHER AND TRACK ACROSS NORTHERN ILLINOIS AND POSSIBLY NORTHWEST
INDIANA INTO THE EVENING.
SURFACE WARM FRONT EXPECTED TO REMAIN IN THE VICINITY OR JUST SOUTH
OF THE TERMINALS. GIVEN HUMID ATMOSPHERE AND ADDITIONAL RAINFALL
AREAS OF MAINLY LIGHT FOG ARE LIKELY OVERNIGHT.
ZEBIC
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* HIGH CONFIDENCE IN SHRA/TSRA...MEDIUM CONFIDENCE IN PRECISE
TIMING
* LOW CONFIDENNCE IN SPECIFC PEAK WIND GUST VALUE - BEST ESTIMATE
45-50 KTS BUT POTENTIAL FOR GUST TO 75 KTS EXISTS.
* LOW CONFIDENCE IN WIND FORECAST ONCE SQUALL LINE MOVES THROUGH...
MAY SEE PERIOD OF EAST WINDS.
* LOW CONFIDENCE IN OVERNIGHT FOG DEVELOPMENT REDUCING VSBYS.
ED F
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT THROUGH FRIDAY...PERIODIC CHANCES FOR
THUNDERSTORMS. OTHERWISE EXPECT VFR CIGS.
FRIDAY AND SATURDAY...CHANCE FOR SHOWERS. MAINLY VFR.
SUNDAY...VFR.
BEACHLER
&&
.MARINE...
411 PM CDT
HIGH PRESSURE REMAINS PARKED OFF THE CAROLINA COASTWHILE LOW
PRESSURE CONTINUES TO DRIFT NORTHWARD ACROSS CENTRAL MANITOBA AND
ONTARIO. ADDITIONAL LOW PRESSURE WILL DEVELOP FROM THE CANADIAN
PRAIRIES TO THE NORTHERN PLAINS TUESDAY AND MOVE EASTWARD INTO
WEDNESDAY WITH A CLOSED LOW DEVELOPING OVER THE WESTERN GREAT LAKES
BY WEDNESDAY NIGHT. A LARGER LOW WILL DEVELOP IVER THE GREAT LAKES
LATER FRIDAY AND LIKELY LINGER THROUGH THE WEEKEND BEFORE HIGH
PRESSURE BUILDS IN FROM THE WEST EARLY NEXT WEEK. SOUTHERN WINDS
WILL BE IN PLACE INTO WEDNESDAY WHEN THE FIRST SFC LOW PASSES WHICH
WILL TURN WINDS WEST AND NORTHWEST. SPEEDS WILL FLUCTUATE UP AND
DOWN UNTIL THE LOW PASSES SIMILAR TO PREVIOUS DAYS. A STABLE AIR
MASS OVER THE WATER WILL KEEP AREAS OF DENSE FOG GOING ACROSS MUCH
OF THE NORTHERN PART OF THE LAKE INTO TUESDAY AND PROBABLY INTO
WEDNESDAY FOR THAT MATTER SO THE DENSE FOG ADVISORY MAY NEED TO BE
EXTENDED. WIND SPEEDS LOOK TO REMAIN ON THE LIGHER SIDE FROM
WEDNESDAY THROUGH THE WEEKEND WITH A FAIRLY BAGGY PRESSURE GRADIENT
DEVELOPING AND THE DIRECTION WILL LIKELY VARY FROM WEST TO NORTH.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ008-ILZ010-ILZ011-ILZ019
UNTIL 7 AM TUESDAY.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565
UNTIL 10 AM TUESDAY.
&&
$$
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AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
510 PM CDT MON JUN 24 2013
.MESOSCALE DISCUSSION...
505 PM CDT
THE MOST FOCUS REMAINS ALONG THE I-88 CORRIDOR AND NORTH AND SOUTH
OF THAT BY AROUND 30 MILES. THE APEX IS MOVING AT A FORWARD SPEED
OF 60+ MPH AND THE MESO-VORTICY NEAR THE DEKALB/LASALLE BORDER HAS
A FAIRLY LONG HISTORY...AFTER WEAKENING SOME FROM BUREAU COUNTY
AND NOW HAS RE-INTENSIFIED. THIS CONTINUES TO BE VERY CLOSE TO A
WEST-TO-EAST BOUNDARY PER EARLIER VISIBLE SATELLITE. 0-3 KM CAPE
FROM SPC RAP OBJECTIVE ANALYSIS HAS VALUES AT 150-175 J/KG...SO
CERTAINLY FAVORABLE FOR STRETCHING ALONG THIS. STILL...THE PRIMARY
WIDESPREAD THREAT REMAINS DAMAGING WINDS PER RADAR AND
ENVIRONMENTAL SIGNATURES.
ON THE LARGE SCALE RADAR AND SATELLITE THIS FORWARD-PROPAGATING MCS
LOOKS VERY WELL-ORGANIZED. THE ENVIRONMENT CONTINUES TO BE
FAVORABLE FOR SUSTAINABILITY...WITH DEEP CAPE AT OR IN EXCESS OF
3000 J/KG...STEEP LOW-LEVEL LAPSE RATES AND ASSOCIATED THETA-E
DIFFERENCE...AND STRONG 0-1 AND 0-3 KM SHEAR ADVECTING EAST WITHIN
THE MCS FOR COLD POOL SUSTAINABILITY.
MTF
.DISCUSSION...
327 PM CDT
SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT...
A VERY ACTIVE PERIOD OF WEATHER IS EXPECTED...AT LEAST FOR PORTIONS
OF THE AREA...THROUGH WEDNESDAY. THIS INCLUDES A FEW PERIODS OF
SEVERE THUNDERSTORMS AND ALSO A GOOD THREAT FOR VERY HEAVY RAINFALL
AND POSSIBLE FLASH FLOODING. AS SUCH...THIS WILL BE THE FOCUS OF THE
FORECAST.
WE HAVE EXTENDED THE FLASH FLOOD WATCH FOR OUR WESTERN COUNTIES
THROUGH TONIGHT.
TEMPERATURES ACROSS NORTHERN ILLINOIS AND NW INDIANA HAVE JUMPED
INTO THE LOW TO MID 80S OVER THE PAST COUPLE HOURS AFTER THE MORNING
CLOUD COVER CLEARED. WITH DEW POINTS NEAR 70...THIS IS RESULTING IN
MLCAPES AROUND 2,000 J/KG ACROSS THE AREA...PER SPC MESOANALYSIS
PAGE. IN ADDITION...IT APPEARS THAT THE 0-6 KM SHEAR MAY END UP A
BIT STRONGER THAN PREVIOUSLY THOUGHT. VWP DATA INDICATES THAT A SPEED
MAX AROUND 50 KT ...ASSOCIATED WITH A MID LEVEL DISTURBANCE MOVING
INTO NORTHWESTERN IOWA...IS PUNCHING EASTWARD ACROSS IOWA. THUS IT
APPEARS THAT 40 KT OF DEEP LAYER SHEER MAY OVERSPREAD THIS AREA
LATER THIS AFTERNOON AND EVENING AS THIS SPEED MAX SHIFTS EASTWARD.
CURRENT THOUGHTS ARE THAT THE LINE OF CONVECTION TO THE WEST WILL
POSE A SEVERE THREAT FOR MOST OF THE AREA INTO THE EARLY EVENING
HOURS. STRONG DAMAGING WINDS...POSSIBLY IN EXCESS OF 80 MPH...WILL
BE THE PRIMARY THREAT ALONG WITH A SMALL POTENTIAL OF SOME
MARGINALLY SEVERE HAIL.
IT APPEARS THE MAIN FOCUS FOR CONVECTION MAY SHIFT NORTH INTO
WISCONSIN LATER TONIGHT AS THE LOW LEVEL JET FOCUSES FARTHER NORTH.
HOWEVER...THIS APPEARS TO BE SHORTED LIVED...AS CONVECTIVE CHANCES
WILL RETURN ON TUESDAY. IT APPEARS THAT ADDITIONAL PERTURBATIONS IN
THE MEAN QUASI-ZONAL MID LEVEL FLOW...WILL INTERACT WITH THE VERY
MOIST AND UNSTABLE ATMOSPHERE ACROSS THE AREA. IT APPEARS THE CAP
WILL REMAIN FAIRLY WEAK DURING THE DAY...SO IT APPEARS THAT AT LEAST
SOME WIDELY SCATTERED CONVECTION MAY OCCUR...MAINLY ACROSS FAR
NORTHERN ILLINOIS. THIS ACTIVITY COULD AGAIN POSS A SEVERE RISK
ACROSS NORTHERN ILLINOIS WITH STEEP MID LEVEL LAPSE RATES HELPING
PRODUCE MLCAPES IN EXCESS OF 3000 J/KG.
TUESDAY CONVECTION LOOKS LIKE IT WILL BECOME MORE NUMEROUS TUESDAY
EVENING/NIGHT. THE QUASI-ZONAL FLOW PATTERN ACROSS THE CONUS IS
EXPECTED TO BEGIN AMPLIFYING...IN RESPONSE TO AN UPPER LOW OVER THE
EASTERN PACIFIC. ULTIMATELY THIS WILL SET THE STAGE FROM A BUILDING
MID/UPPER LEVEL RIDGE ACROSS THE WESTERN CONUS AND FALLING HEIGHTS
ACROSS THE GREAT LAKES REGION. THIS PROCESS SHOULD ALLOW
ANOTHER...STRONGER...SHORT WAVE TO MOVE ACROSS THE AREA ON
WEDNESDAY. IT APPEARS THIS FEATURE WILL FOCUS THE NOSE OF A 40 KT
LOW LEVEL JET RIGHT ACROSS SOUTHERN WISCONSIN AND NORTHERN ILLINOIS
TUESDAY NIGHT INTO WEDNESDAY. THIS COULD SET THE STAGE FOR VERY HEAVY
RAINFALL ACROSS PORTIONS OF NORTHERN ILLINOIS INTO WEDNESDAY. THIS
LOOKS TO BE THE PERIOD TO REALLY WATCH FOR POSSIBLE FLOODING ACROSS
THE AREA. PWATS ARE PROGGED TO REACH NEARLY 2.00 INCHES...WHICH IS
AROUND THE 99 PERCENTILE. IN ADDITION...THE SOUTHWESTERLY ORIENTATION
OF THE LOW LEVEL JET COULD OFFSET THE MEAN CLOUD BEARING
FLOW...POSSIBLY RESULTING IN SLOW MOVING OR BACK BUILDING SEGMENTS
TUESDAY NIGHT. HOWEVER...CONFIDENCE IN THE EXACT PLACEMENT OF THE
HEAVIEST RAIN REMAINS IN QUESTION AT THIS TIME...BUT GUIDANCE IS
HINTING THAT NORTHERN ILLINOIS COULD LIE IN THE FAVORED ZONE. THIS
WILL HAVE TO BE WATCHED...WITH THE POSSIBLY OF A FLASH FLOOD WATCH
NEEDED FOR PORTIONS OF NORTHERN ILLINOIS AND NORTHWESTERN INDIANA
DURING THIS PERIOD.
THE SEVERE CONVECTIVE THREAT SHOULD BEGIN TO WANE WEDNESDAY
EVENING AS THE MID LEVEL DISTURBANCE SHIFT EAST OF THE AREA.
TEMPERATURES LOOK TO CONTINUE TO BE PROBLEMATIC FOR THE NEXT COUPLE
OF DAYS...WITH ADDITIONAL BUST POTENTIAL WITH CONVECTIVE ACTIVITY.
HOWEVER...I ONLY MADE MINOR CHANCES TO THE GOING TEMP
FORECAST...MAINLY TO COOL THE NORTHERN AREAS BY A COUPLE DEGREES.
KJB
EXTENDED FORECAST...THURSDAY THROUGH MONDAY...
QUASI ZONAL FLOW IN THE SOUTHERN STREAM EARLY IN THE WEEK WILL
TRANSITION BY THE SECOND HALF OF THE WEEK TO AN INCREASINGLY
AMPLIFIED BROAD WESTERN CONUS RIDGE AND ITS CORRESPONDING LONGWAVE
TROUGH OVER THE EASTERN CONUS. THIS WOULD PUT THE LOCAL AREA IN
NORTHWEST UPPER FLOW EARLY IN THE WEEKEND...AND THEN UNDER AN UPPER
LOW PUSHING SOUTHWEST ACROSS THE GREAT LAKES BY SUNDAY. THE MOST
OBVIOUS RAMIFICATION WILL BE MUCH COOLER HIGHS...ESPECIALLY FOR THE
WEEKEND AND EARLY NEXT WEEK. IN ADDITION...GFS/ECMWF ARE SUGGESTING
THE POSSIBILITY OF THUNDERSTORMS TRIGGERED BY SHORTWAVE ENERGY
DROPPING ACROSS THE AREA INTO THE BASE OF THE EASTERN TROUGH
THURSDAY AND FRIDAY...WHEN CONSIDERABLE LOW LEVEL MOISTURE REMAINS
IN PLACE OVER THE AREA. DEWPOINTS FALL ALONG WITH THE TEMPERATURES
BY THE WEEKEND...BUT THE DEEPENING UPPER LOW ALSO SUPPORTS A
CONTINUED CHANCE OF SHOWERS INTO MONDAY.
EML
&&
.HYDROLOGY...
433 PM CDT
A SHORT PERIOD OF HEAVY RAINFALL WILL ACCOMPANY THE LINE OF STORMS
CURRENTLY APPROACHING NORTH CENTRAL ILLINOIS. THIS COULD RESULT IN
SOME MINOR FLOODING...ESPECIALLY IN AREAS THAT WERE HIT WITH 1 TO 2
INCHES OF RAINFALL THIS MORNING. HOWEVER...ADDITIONAL PERIODS OF
HEAVY RAINFALL ARE EXPECTED LATE TUESDAY INTO WEDNESDAY. DURING THIS
PERIOD PRECIPITABLE WATER VALUES COULD BE AROUND 2 INCHES...WHICH
IS AROUND THE 99TH PERCENTILE. ANOTHER DECENT MID LEVEL DISTURBANCE
IS EXPECTED TO APPROACH THE AREA TUESDAY NIGHT AND INTO
WEDNESDAY...AND THIS SYSTEM LOOKS TO INDUCE A SOUTHWESTERLY LOW
LEVEL JET...THAT COULD OFFSET THE FORWARD STORM MOTION...RESULTING
IN SLOW MOVING OR BACK BUILDING THUNDERSTORMS TUESDAY NIGHT INTO
WEDNESDAY. AT THIS TIME...UNCERTAINTY REMAINS AS TO WHERE EXACTLY
THE HEAVIEST RAIN WILL FALL...BUT GUIDANCE CONTINUES TO HINT AT
NORTHERN ILLINOIS AND NORTHWESTERN INDIANA. THIS WILL HAVE TO BE
WATCHED FOR POSSIBILITY OF A FLASH FLOOD WATCH FOR MOST OF THE
AREA AS RAINFALL AMOUNTS IN EXCESS OF 2 INCHES IS CERTAINLY
POSSIBLE ACROSS PORTIONS OF THE AREA.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SHRA/TSRA INTO EVENING AND ASSOCIATED POTENTIALLY ERRATIC WIND.
* PSBL FOG DEVELOPMENT OVERNIGHT INTO EARLY TUE.
ZEBIC
//DISCUSSION...UPDATED 18Z...
WARM AND HUMID CONDITIONS IN PLACE ALONG WITH VARIOUS BOUNDARIES TO
KEEP NEXT ROUND OF SHRA/TSRA IN THE FORECAST INTO THIS EVENING.
ATMOSPHERE TO CONTINUE TO RECOVER FROM MORNING CONVECTIVE ACTIVITY.
THINKING IS A FEW TSRA ARE POSSIBLE BY MID AFTERNOON IN AREAS OF
LESSENING/THINNING OF CLOUD COVER AND MAY EXPAND IN COVERAGE BY LATE
AFTERNOON IF MORE WIDESPREAD SUNSHINE OCCURS. CIRROSTRATUS SHIELD
ASSOCIATED WITH ORGANIZED AREAS OF TSRA/SHRA OVER IA MAY LIMIT
AMOUNT/DURATION OF SUN. TSRA CLUSTERS OVER IA EXPECTED TO ORGANIZE
FURTHER AND TRACK ACROSS NORTHERN ILLINOIS AND POSSIBLY NORTHWEST
INDIANA INTO THE EVENING.
SURFACE WARM FRONT EXPECTED TO REMAIN IN THE VICINITY OR JUST SOUTH
OF THE TERMINALS. GIVEN HUMID ATMOSPHERE AND ADDITIONAL RAINFALL
AREAS OF MAINLY LIGHT FOG ARE LIKELY OVERNIGHT.
ZEBIC
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN SHRA/TSRA...MEDIUM CONFIDENCE IN PRECISE
TIMING/COVERAGE.
* HIGH CONFIDENCE IN WIND FORECAST.
* LOW CONFIDENCE IN OVERNIGHT FOG DEVELOPMENT REDUCING VSBYS.
ZEBIC
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT THROUGH FRIDAY...PERIODIC CHANCES FOR
THUNDERSTORMS. OTHERWISE EXPECT VFR CIGS.
FRIDAY AND SATURDAY...CHANCE FOR SHOWERS. MAINLY VFR.
SUNDAY...VFR.
BEACHLER
&&
.MARINE...
411 PM CDT
HIGH PRESSURE REMAINS PARKED OFF THE CAROLINA COASTWHILE LOW
PRESSURE CONTINUES TO DRIFT NORTHWARD ACROSS CENTRAL MANITOBA AND
ONTARIO. ADDITIONAL LOW PRESSURE WILL DEVELOP FROM THE CANADIAN
PRAIRIES TO THE NORTHERN PLAINS TUESDAY AND MOVE EASTWARD INTO
WEDNESDAY WITH A CLOSED LOW DEVELOPING OVER THE WESTERN GREAT LAKES
BY WEDNESDAY NIGHT. A LARGER LOW WILL DEVELOP IVER THE GREAT LAKES
LATER FRIDAY AND LIKELY LINGER THROUGH THE WEEKEND BEFORE HIGH
PRESSURE BUILDS IN FROM THE WEST EARLY NEXT WEEK. SOUTHERN WINDS
WILL BE IN PLACE INTO WEDNESDAY WHEN THE FIRST SFC LOW PASSES WHICH
WILL TURN WINDS WEST AND NORTHWEST. SPEEDS WILL FLUCTUATE UP AND
DOWN UNTIL THE LOW PASSES SIMILAR TO PREVIOUS DAYS. A STABLE AIR
MASS OVER THE WATER WILL KEEP AREAS OF DENSE FOG GOING ACROSS MUCH
OF THE NORTHERN PART OF THE LAKE INTO TUESDAY AND PROBABLY INTO
WEDNESDAY FOR THAT MATTER SO THE DENSE FOG ADVISORY MAY NEED TO BE
EXTENDED. WIND SPEEDS LOOK TO REMAIN ON THE LIGHER SIDE FROM
WEDNESDAY THROUGH THE WEEKEND WITH A FAIRLY BAGGY PRESSURE GRADIENT
DEVELOPING AND THE DIRECTION WILL LIKELY VARY FROM WEST TO NORTH.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ008-ILZ010-ILZ011-ILZ019
UNTIL 7 AM TUESDAY.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565
UNTIL 10 AM TUESDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
1201 PM CDT MON JUN 24 2013
.DISCUSSION...
ISSUED 1028 AM CDT MON JUN 24 2013
HAVE MADE ONLY MINOR CHANGES TO GRIDS AND ZFP THIS MORNING TO
REFLECT THE CONTINUED POTENTIAL FOR THE REDEVELOPMENT OF SHOWERS
AND THUNDERSTORMS NORTH OF I-74. HRRR RUNS CONTINUE TO ALTERNATE
BETWEEN LOW POPS FOR THE REMAINDER OF THE DAY AND AN MCS ROLLING
ACROSS THE REGION. WITH SHORTWAVE NOW MOVING ACROSS IOWA COMBINING
WITH ANTECEDENT BOUNDARIES AND ABUNDANT PRECIP WATER...OVER 2
STANDARD DEVIATIONS ABOVE CLIMATOLOGY...HAVE INCREASED POPS NORTH
OF I-74 AND LOWERED HIGHS THERE. HAVE ALSO MADE SOME ADJUSTMENTS
TO REFLECT ONLY SCATTERED CLOUDS IN KIJX/KSPI AREA.
BARKER
&&
.AVIATION...
ISSUED 1201 PM CDT MON JUN 24 2013
DIFFICULT TO DELINEATE DETAILS IN THIS AFTERNOONS FORECAST. LOTS
OF PLAYERS IN THE GAME THIS TIME AROUND. SHORTWAVE CROSSING IOWA
IS CURRENTLY PRODUCING STRONG TO SEVERE CONVECTION. AS THE FORCING
PUSHES EAST IT WILL INTERACT WITH RESIDUAL BOUNDARIES ACROSS
ILLINOIS FROM LAST NIGHTS DOWNPOURS. ABUNDANT MOISTURE EVIDENT
WITH 2+ STANDARD DEVIATION PRECIP WATER VALUES IN PLACE. HOWEVER...MODELS
ARE FORECASTING SOME WARMING AT MID-LEVELS WHICH MAY LIMIT COVERAGE
OF CONVECTION BY THE TIME IT REACHES CENTRAL ILLINOIS TAF SITES.
FOR NOW WILL ASSUME THAT COLD POOL BEHIND INCOMING CONVECTION WILL
BE SUFFICIENT TO COMPENSATE FOR ANY FORECASTED WARMING AND WILL
HIT CONVECTION HARD...PARTICULARLY IN THE WESTERN TERMINALS LATE
THIS AFTERNOON AND EARLY EVENING.
IN SHORT-TERM...A PACKET OF GRAVITY WAVES IS PUSHING SOUTH THROUGH
CENTRAL ILLINOIS AT THIS TIME ENABLING SOME LOW CLOUDS TO BRIEFLY
IMPACT TERMINALS AND PRODUCING SOME WIND SHIFTS. WILL INCLUDE AS
MUCH DETAIL AS POSSIBLE...BUT SOME GENERALIZATIONS WILL BE NECESSARY.
BARKER
&&
.PREV DISCUSSION...
ISSUED 240 AM CDT MON JUN 24 2013
ONGOING PARADE OF MCS ACTIVITY AND ASSOCIATED HEAVY RAINFALL WILL
CONTINUE TO BE A CONCERN FOR A COUPLE MORE DAYS. LATEST MCS
COVERED A GOOD PORTION OF IOWA...ALBEIT A BIT SMALLER THAN RECENT
NIGHTS...AND WAS BEING FED BY 40-45 KNOT LOW LEVEL JET. HAVE HAD
SOME STRONG THUNDERSTORMS SPREADING INTO THE NORTHWEST CWA OVER
THE LAST COUPLE HOURS ALONG A VERY SUBTLE SURFACE BOUNDARY.
MESOSCALE VORTEX FROM SUNDAY CONVECTION OVER THE SOUTHEAST CWA
STILL EVIDENT ON RADAR IMAGERY JUST EAST OF MOUNT VERNON.
SHORT TERM...TODAY THROUGH WEDNESDAY...
AS THE CASE HAS BEEN OVER THE LAST FEW DAYS...MODEL SOLUTIONS ARE
FAIRLY VARIED WITH MESOSCALE FEATURES NOT HANDLED ESPECIALLY WELL.
MCV IS ROTATING SOUTHEAST AND ACTIVITY WITH THIS FEATURE SHOULD
BE OUT OF OUR AREA BY SUNRISE...SO AM PLANNING TO KEEP THE FAR
SOUTHEAST DRY THIS MORNING. FOCUS DURING THE MORNING WILL MORE BE
ACROSS THE NORTHWEST AND ANY INFLUENCES FROM LEFTOVER BOUNDARIES
AND NEWER ONES FROM THE CURRENT CONVECTION. WILL HAVE THE HIGHEST
POPS DURING THE AFTERNOON AS MORE OF THE DAYTIME HEATING IS A
FACTOR. PRECIPITABLE WATER VALUES AROUND 1.7 TO 1.8 INCHES POINT
TO SOME HEAVY DOWNPOURS AGAIN...ALTHOUGH CENTRAL PARTS OF THE CWA
ARE MORE ABLE TO HANDLE THE HEAVY RAIN THAN THE SOUTHEAST...WHERE
1-HOUR FLASH FLOOD GUIDANCE IS ONLY AROUND A HALF INCH FROM
EFFINGHAM TO FLORA. MAIN SEVERE WEATHER RISK WILL BE WEST OF I-55
THIS AFTERNOON WHERE 0-6KM SHEAR EXPECTED TO INCREASE TO AROUND 40
KNOTS...ALTHOUGH A PULSE SEVERE STORM CANNOT BE RULED OUT
ELSEWHERE.
MAIN THUNDERSTORM FOCUS SHIFTS NORTHWARD LATE TONIGHT THROUGH
TUESDAY NIGHT. WITH MORE SUNSHINE...TUESDAY SHOULD BE THE HOTTEST
DAY OF THE WEEK WITH HEAT INDEX VALUES AT OR JUST ABOVE 100. HAVE
SOME CONCERN FOR SIMILAR VALUES WEDNESDAY...ALTHOUGH THIS WILL
DEPEND ON TIMING OF A FRONTAL PASSAGE AND ASSOCIATED
THUNDERSTORMS. MORE WIDESPREAD RISK OF SEVERE WEATHER EXPECTED ON
WEDNESDAY WHICH WOULD HELP TEMPER THE HIGHS SOMEWHAT. SOME
ADDITIONAL HEAVY RAIN LIKELY AGAIN ON WEDNESDAY WITH THE STORMS...
AS PWAT VALUES RISE BACK TO AROUND 1.8 INCHES.
LONG TERM...THURSDAY THROUGH SUNDAY...
UPPER RIDGING STILL PROGGED TO BUILD ACROSS THE WESTERN CONUS
DURING THE LATTER PART OF THE WEEK...WITH A SLOW COOLING TREND.
CYCLONIC FLOW OVER THE GREAT LAKES JUSTIFIES SOME LOW CHANCE POPS
OR SLIGHT CHANCES THURSDAY THROUGH FRIDAY...BUT THIS SHOULD FADE
AS HIGH PRESSURE BUILDS IN FROM THE NORTHWEST OVER THE WEEKEND.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1029 AM CDT MON JUN 24 2013
.DISCUSSION...
ISSUED 1028 AM CDT MON JUN 24 2013
HAVE MADE ONLY MINOR CHANGES TO GRIDS AND ZFP THIS MORNING TO
REFLECT THE CONTINUED POTENTIAL FOR THE REDEVELOPMENT OF SHOWERS
AND THUNDERSTORMS NORTH OF I-74. HRRR RUNS CONTINUE TO ALTERNATE
BETWEEN LOW POPS FOR THE REMAINDER OF THE DAY AND AN MCS ROLLING
ACROSS THE REGION. WITH SHORTWAVE NOW MOVING ACROSS IOWA COMBINING
WITH ANTICEDENT BOUNDARIES AND ABUNDANT PRECIP WATER...OVER 2
STANDARD DEVIATIONS ABOVE CLIMATOLOGY...HAVE INCREASED POPS NORTH
OF I-74 AND LOWERED HIGHS THERE. HAVE ALSO MADE SOME ADJUSTMENTS
TO REFLECT ONLY SCTATERED CLOUDS IN KIJX/KSPI AREA.
BARKER
&&
.AVIATION...
ISSUED 600 AM CDT MON JUN 24 2013
MAIN CONCERN WILL BE COVERAGE OF STORMS AGAIN TODAY AND THEIR
AFFECT ON CIGS AND VSBYS...OTHERWISE...WE EXPECT MAINLY VFR
CONDITIONS DURING THIS PERIOD (TIL 12Z TUE). MAIN BAND OF
STORMS HAS STAYED ROUGHLY NORTH OF A PIA TO BMI LINE THIS
MORNING. PIA EXPERIENCING SOME OCCASIONAL MVFR CIGS WITH
SOME OF THE HEAVIER SHOWERS THIS MORNING BUT AS THE AREA OF
RAIN GRADUALLY SHIFT TO THE NORTH AND EAST LATER IN THE
MORNING...EXPECT MAINLY VFR CONDITIONS TO PREVAIL AT PIA.
SCATTERED STORMS ARE AGAIN EXPECTED THIS AFTN INTO EARLY
THIS EVENING (ROUGHLY FROM 20Z-02Z) AS ANOTHER WEAK UPPER
LEVEL DISTURBANCE BRINGS THE ROUND OF STORMS THRU. COVERAGE
AT THIS POINT LOOKS TO SCATTERED TO INCLUDE A TEMPO GROUP
FOR ANY ONE SITE SO WILL CONTINUE WITH VCTS. SFC WINDS
WILL BE SOUTHERLY 12 TO 17 KTS TODAY AND AROUND 10 KTS TNT.
SMITH
&&
.PREV DISCUSSION...
ISSUED 240 AM CDT MON JUN 24 2013
ONGOING PARADE OF MCS ACTIVITY AND ASSOCIATED HEAVY RAINFALL WILL
CONTINUE TO BE A CONCERN FOR A COUPLE MORE DAYS. LATEST MCS
COVERED A GOOD PORTION OF IOWA...ALBEIT A BIT SMALLER THAN RECENT
NIGHTS...AND WAS BEING FED BY 40-45 KNOT LOW LEVEL JET. HAVE HAD
SOME STRONG THUNDERSTORMS SPREADING INTO THE NORTHWEST CWA OVER
THE LAST COUPLE HOURS ALONG A VERY SUBTLE SURFACE BOUNDARY.
MESOSCALE VORTEX FROM SUNDAY CONVECTION OVER THE SOUTHEAST CWA
STILL EVIDENT ON RADAR IMAGERY JUST EAST OF MOUNT VERNON.
SHORT TERM...TODAY THROUGH WEDNESDAY...
AS THE CASE HAS BEEN OVER THE LAST FEW DAYS...MODEL SOLUTIONS ARE
FAIRLY VARIED WITH MESOSCALE FEATURES NOT HANDLED ESPECIALLY WELL.
MCV IS ROTATING SOUTHEAST AND ACTIVITY WITH THIS FEATURE SHOULD
BE OUT OF OUR AREA BY SUNRISE...SO AM PLANNING TO KEEP THE FAR
SOUTHEAST DRY THIS MORNING. FOCUS DURING THE MORNING WILL MORE BE
ACROSS THE NORTHWEST AND ANY INFLUENCES FROM LEFTOVER BOUNDARIES
AND NEWER ONES FROM THE CURRENT CONVECTION. WILL HAVE THE HIGHEST
POPS DURING THE AFTERNOON AS MORE OF THE DAYTIME HEATING IS A
FACTOR. PRECIPITABLE WATER VALUES AROUND 1.7 TO 1.8 INCHES POINT
TO SOME HEAVY DOWNPOURS AGAIN...ALTHOUGH CENTRAL PARTS OF THE CWA
ARE MORE ABLE TO HANDLE THE HEAVY RAIN THAN THE SOUTHEAST...WHERE
1-HOUR FLASH FLOOD GUIDANCE IS ONLY AROUND A HALF INCH FROM
EFFINGHAM TO FLORA. MAIN SEVERE WEATHER RISK WILL BE WEST OF I-55
THIS AFTERNOON WHERE 0-6KM SHEAR EXPECTED TO INCREASE TO AROUND 40
KNOTS...ALTHOUGH A PULSE SEVERE STORM CANNOT BE RULED OUT
ELSEWHERE.
MAIN THUNDERSTORM FOCUS SHIFTS NORTHWARD LATE TONIGHT THROUGH
TUESDAY NIGHT. WITH MORE SUNSHINE...TUESDAY SHOULD BE THE HOTTEST
DAY OF THE WEEK WITH HEAT INDEX VALUES AT OR JUST ABOVE 100. HAVE
SOME CONCERN FOR SIMILAR VALUES WEDNESDAY...ALTHOUGH THIS WILL
DEPEND ON TIMING OF A FRONTAL PASSAGE AND ASSOCIATED
THUNDERSTORMS. MORE WIDESPREAD RISK OF SEVERE WEATHER EXPECTED ON
WEDNESDAY WHICH WOULD HELP TEMPER THE HIGHS SOMEWHAT. SOME
ADDITIONAL HEAVY RAIN LIKELY AGAIN ON WEDNESDAY WITH THE STORMS...
AS PWAT VALUES RISE BACK TO AROUND 1.8 INCHES.
LONG TERM...THURSDAY THROUGH SUNDAY...
UPPER RIDGING STILL PROGGED TO BUILD ACROSS THE WESTERN CONUS
DURING THE LATTER PART OF THE WEEK...WITH A SLOW COOLING TREND.
CYCLONIC FLOW OVER THE GREAT LAKES JUSTIFIES SOME LOW CHANCE POPS
OR SLIGHT CHANCES THURSDAY THROUGH FRIDAY...BUT THIS SHOULD FADE
AS HIGH PRESSURE BUILDS IN FROM THE NORTHWEST OVER THE WEEKEND.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
319 AM CDT MON JUN 24 2013
.DISCUSSION...
723 PM CDT
MADE MINOR TWEAKS TO THE GOING FORECAST. CONVECTION HAS SUBSIDED
WITH SHOWERS FROM CHICAGO THROUGH STREATOR. EXPECTING THE SHOWERS
TO SLOWLY WEAKEN AND MOVE EASTWARD...PRODUCING UP TO AN ADDITIONAL
TENTH OF AN INCH OF PRECIP. THE CONVECTIVE OUTFLOW COOLED AREAS
BUT MOST PLACES HAVE REBOUNDED...SO ADJUSTED TEMPS TRENDS BUT DID
NOT MAKE MAJOR CHANGES TO LOW TEMPS TONIGHT.
AS FAR AS PRECIP CHANCES THROUGH THE REST OF THE NIGHT...MADE
MINOR ADJUSTMENTS BUT THE OVERALL PICTURE REMAINS THE SAME.
EXPECTING CONVECTION TO REFIRE IN THE FOUR CORNERS AREA OF
NE/IA/MO/KS AND SPREAD ACROSS IA OVERNIGHT. STEERING FLOW WOULD
DIRECT THE STORMS TO THE EAST WITH STORMS ENTERING AREAS ALONG AND
WEST OF THE I-39 CORRIDOR AROUND/AFTER 09Z. HOWEVER CONFIDENCE IS
LOW TO MEDIUM IN HOW CONVECTION WILL EVOLVE AND LOW IN TIMING.
HEAVY RAIN IS A DEFINITE CONCERN...BUT DUE TO LOW CONFIDENCE IN
THE CONVECTIVE EVOLUTION I WILL HOLD OFF ISSUING A FLASH FLOOD
WATCH. LIGHTNING...GUSTY WINDS...AND SMALL HAIL ARE ALSO
POSSIBLE...BUT THINKING SEVERE WEATHER WILL BE ISOLATED AT BEST
DUE TO THE ELEVATED NATURE OF THE STORMS.
JEE
//PREV DISCUSSION...
304 PM CDT
SHOWER/THUNDER CHANCES REMAIN THE BIGGEST FORECAST CHALLENGE
FOLLOWED BY TEMPS WHICH MAY BE AFFECTED BY THE CONVECTION. AFTERNOON
WATER VAPOR IMAGERY SHOWS ONE UPPER LEVEL LOW SPINNING OVER THE
CENTRAL APPALACHIANS WHICH IS LOSING DEFINITION AS IS MOVES SLOWLY
NORTHWARD. THE NEXT UPPER LOW IS SPINNING OVER THE SOUTHERN
CANADIAN PRAIRIES WITH A TROUGH AXIS EXTENDING INTO THE DAKOTAS AND
LIFTING NORTHEAST. THE UPPER FLOW IS LESS AMPLIFIED FURTHER SOUTH OF
THE LOW ACROSS THE CENTRAL PLAINS BUT THERE ARE SEVERAL EMBEDDED
WAVES THAT ARE TRANSLATING NORTHEAST AS WELL. THE NEXT UPPER LOW OF
NOTE IS COMING ONSHORE OVER THE WEST COAST AND HELPING TO AMPLIFY A
RIDGE OVER OREGON/WASHINGTON. ENERGY EMANATING FROM THIS TROUGH WILL
BECOME A PLAYER IN OUR WEATHER LATER THIS WEEK. AT THE SURFACE...LOW
PRESSURE IS POSITIONED OVER NORTHWEST MINNESOTA WITH WEAKER LOW
PRESSURE SPREAD ACROSS THE PLAINS. A COOL FRONTAL BOUNDARY IS
STRETCHED FROM THE MN LOW BUT HAS BECOME DIFFICULT TO IDENTIFY
THANKS TO COLD POOLS FROM MORNING CONVECTION.
THROUGH THIS EVENING...TOUGH FORECAST ONCE AGAIN IN TERMS OF
CONVECTIVE POTENTIAL AND EVOLUTION THROUGH THE PERIOD. OUTFLOW
BOUNDARY FROM EARLIER IOWA CONVECTION IS NOW PUSHING INTO THE
WESTERN CWA TRIGGERING THUNDERSTORMS ALONG IT. A BETTER ORGANIZED
COMPLEX OF STORMS HAS DEVELOPED FROM THE EARLIER CONVECTION BUT IS
MOVING SOUTHEAST ACROSS NORTHERN MISSOURI INTO THE AXIS OF MUCH
BETTER INSTABILITY AS WELL AS BETTER MID LEVEL MOISTURE
ADVECTION. ADDITIONAL SCATTERED STORMS HAVE DEVELOPED OVER THE
SOUTHERN CWA LIKELY IN BETTER CONJUNCTION WITH THE WEAKENING UPPER
LOW OVER APPALACHIA. IN THE NEAR TERM...EXPECT THE OUTFLOW TO
CONTINUE EASTWARD ACROSS THE CWA TRIGGERING SCATTERED STORMS THROUGH
LATE AFTERNOON/EARLY EVENING. MESOANALYSIS SHOWS 2000+ J/KG OF MIXED
LAYER CAPE OVER THE AREA SUPPORTING STRONG UPDRAFTS BUT DEEP LAYER
SHEAR IS WEAK SO CORES SHOULD BE PRETTY PULSEY. LARGE HAIL AND
LOCALLY HEAVY DOWNPOURS ARE THE MAIN CONCERN. GUSTY WINDS ARE ALSO
POSSIBLE BUT RECENT AIRCRAFT SOUNDINGS FROM MDW DO NOT SHOW A TON OF
DRY LOW LEVEL AIR AND RAP ANALYSIS OF DCAPE IS LOW AS WELL. WOULD
EXPECT THAT THIS ACTIVITY WOULD WANE WITH SUNSET.
REST OF TONIGHT AND MONDAY...ATTENTION TURNS TO ADDITIONAL
CONVECTIVE POTENTIAL OVERNIGHT. WATER VAPOR SHOWS A WAVE OVER NE
KS/NW MO WHICH APPEARS TO BE TURNING MORE EASTWARD IN THE LAST FEW
SCANS. THIS IS LIKELY HELPING THE COMPLEX TAKING SHAPE OVER MO.
SHORT TERM/HIGH RES GUIDANCE HAS BEEN ALL OVER THE PLACE WITH HOW
CONVECTION EVOLVES THROUGH TONIGHT. THE MOIST SOUTHWESTERLY FLOW
WILL CONTINUE ACROSS THE REGION TONIGHT AND THE EARLIER COLD FRONTAL
BOUNDARY SEEMS TO BE DEVELOPING ONCE AGAIN ACROSS IOWA AS THE FLOW
HAS SETTLED FROM EARLIER CONVECTION. THIS IS SUPPORTIVE OF NEW
DEVELOPMENT TO THE WEST TONIGHT. THE OUTFLOW CURRENTLY WORKING INTO
THE LOCAL AREA EXTENDS INTO WEST-CENTRAL ILLINOIS AND THERE ARE
HINTS THAT THE SOUTHERN EXTENT OF IT AND LIKELY A BOUNDARY SET UP BY
THE CURRENT COMPLEX MAY STALL OUT SOMEWHERE NOT FAR FROM THE
SOUTHWESTERN CWA. IN ADDITION...THE KS/MO WAVE IS EXPECTED TO CROSS
THIS SAME AREA TONIGHT WHICH IS ALSO EXPECTED TO BE IN AN AREA OF
MID LEVEL WARM ADVECTION. THEREFORE IT IS POSSIBLE ROUNDS OF
CONVECTION COULD DEVELOP TO THE SOUTHWEST OF THE AREA AND ROLL
EASTWARD INTO THE SOUTHERN CWA OVERNIGHT. HAVE NOT MADE MUCH CHANGE
TO OVERNIGHT POPS BUT DID INCREASE THEM SOMEWHAT OVER THE FAR SOUTH.
AS FOR MONDAY...GUIDANCE REMAINS IN POOR AGREEMENT WITH TRACK OF
POTENTIAL UPPER WAVES BUT WATER VAPOR DOES SHOW SOME SIGNS OF A WAVE
COMING ACROSS THE FOUR CORNERS THIS AFTERNOON. THIS WOULD COME ACROSS
THE REGION LATER MONDAY BUT IT IS NOT CLEAR IF IT WILL BE MORE
FOCUSED TO THE NORTH OF THE AREA. WILL CONTINUE WITH MID CHANCE POPS
WITH LATER IN THE DAY MORE FAVORED. PROVIDED THE LATER TIMING WORKS
OUT THEN WE WILL HAVE A BETTER CHANCE TO WARM BUT THERE MAY BE
CONVECTIVE DEBRIS AROUND SO WILL HOLD TEMPS INTO THE MID 80S FOR
MOST AREAS.
TUESDAY THROUGH SUNDAY...THE UPPER FLOW BECOMES LESS AMPLIFIED
TUESDAY BUT WILL LIKELY STILL BE LITTERED WITH WAVES TRAVERSING IT.
HOT AND HUMID AIR WILL STILL BE IN PLACE WITH PRECIPITABLE WATER
VALUES HOVERING AROUND 1.75 INCHES. THESE FACTORS PROVIDE CONTINUED
SUPPORT FOR THUNDERSTORM DEVELOPMENT BUT THERE IS NOT MUCH TO KEY IN
ON FOR A COHERENT FORCING MECHANISM GIVEN THE LOW AMPLITUDE PATTERN.
BY WEDNESDAY...THERE IS SOME AGREEMENT ON SURFACE LOW PRESSURE
HAVING DEVELOPED ACROSS THE CANADIAN PRAIRIES WITH A TROUGH
AXIS/FRONT EXTENDING INTO MINNESOTA AND IOWA...WITH A SECONDARY LOW
POSSIBLY DEVELOPING ACROSS MINNESOTA. THE FRONT LOOKS TO CROSS THE
AREA LATER WEDNESDAY BRINGING SHOWER AND STORM CHANCES WITH IT.
UPPER RIDGING WILL BE BUILDING ACROSS THE WESTERN U.S. AND HIGH
PLAINS WITH A WAVE ORIGINATING FROM THE TROUGH OFF THE WEST COAST
OVERTOPPING THE RIDGE ACROSS THE CANADIAN ROCKIES AND DROPPING
SOUTHEASTWARD INTO THE GREAT LAKES WHILE AMPLIFYING LATE IN THE
WEEK. GFS AND ECMWF DIFFER ON HOW QUICKLY THIS OCCURS BUT THE SIGNAL
HAS BEEN CONSISTENT OVERALL. THIS WILL BRING A SHIFT TO
NORTHWESTERLY AT THE SURFACE AND ALOFT LATE IN THE WEEK AND
NOTICEABLY COOLER TEMPERATURES BY SATURDAY OR SO. LOW POPS WILL
CONTINUE WITH THE FLOW CONTINUING TO FAVOR WEAK SHORTWAVE PASSAGES.
HIGH TEMPS WILL LIKELY HOVER AROUND 90 TUESDAY AND WEDNESDAY
ASSUMING CONVECTION OR CONVECTIVE DEBRIS IS NOT AN ISSUE...WHICH
WOULD SIGNIFICANTLY LOWER HIGHS IF IT IS. WITH THE PASSAGE OF THE
SYSTEM LATER WEDNESDAY COOLER MID LEVEL AIR WILL FILTER IN KEEPING
HIGHS BACK IN THE 80S WITH UPPER 70S POSSIBLE FRIDAY AND SATURDAY.
MDB
&&
.HYDROLOGY...
745 PM CDT
THE CONVECTIVE ACTIVITY THIS EVENING PRODUCED ISOLATED AREAS OF 2+
INCHES OF RAIN AND A BAND OF 1+ INCHES OF RAIN ACROSS LA SALLE
COUNTY. STILL CONSIDERED A FLASH FLOOD WATCH FOR THE WEST AND FAR
SOUTHWEST CWA GIVEN THE RAINFALL OF THE PAST FEW DAYS. CONFIDENCE
REMAINS LOW IN WHERE ORGANIZED CONVECTION WILL SET UP TONIGHT AND
MONDAY SO WILL HOLD OFF UNTIL AREAS AND TIMING CAN BE BETTER
DEFINED.
JEE/MDB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* MAINLY SOUTHERLY WINDS ARND 10KT...OCCASIONAL GUSTS LATE
MORNING/AFTN TO 20-24KT. IF TSRA DEVELOP WIND DIR COULD BECOME
VRB FOR A PERIOD OF TIME.
* PRECIP DEVELOPS...LOW COVERAGE EXPECTED LATE THIS MORNING THRU
AFTN.
BEACHLER
//DISCUSSION...UPDATED 06Z...
SIMILAR SETUP AGAIN TODAY AS HAS BEEN THE CASE THE PAST FEW
DAYS...ISOLATED TSRA DEVELOPING. EXPECT MAINLY SOUTHERLY WINDS
ARND 10KT INCREASING WITH GUSTS TO 20-24KT BY LATE MORNING THRU
THE AFTN. THE WILDCARD WILL BE CLOUD COVER WHICH COULD LIMIT HOW
GUSTY WINDS BECOME. THEN THE FOCUS TURNS TOWARDS TIMING OF
PRECIP DEVELOPMENT. EARLY THIS MORNING AN AREA OF SHRA/TSRA WAS
PULSING NORTHEAST...HOWEVER IT DOES NOT APPEAR THIS SHOULD HOLD
TOGETHER AND IMPACT THE TAF SITES. LATER THIS MORNING A WEAK WAVE
DOES TRY TO PUSH OVERHEAD...AND EXPECT SLOW DEVELOPMENT TO
THUNDERSTORMS MIDDAY/AFTN. THE COVERAGE SHOULD BE MINIMAL AND MORE
OF A PULSE LIKE ENVIRONMENT...WHICH COULD POSE A CHALLENGE FOR A
FEW SITES SEEING CHAOTIC WIND DIR/SPEEDS FOR A BRIEF PERIOD OF
TIME IN/AROUND THUNDERSTORMS.
WINDS THEN BEGIN TO DIMINISH TO ARND 5-7KT OVERNIGHT INTO EARLY
TUE...WITH POSSIBLY A REPEAT WITH ISOLATED SHRA/TSRA IN THE AREA
AFT 06Z TUE.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM CONFIDENCE IN TIMING OF SHRA/TSRA DEVELOPMENT.
* HIGH CONFIDENCE IN MAINLY SOUTHERLY WIND SPEEDS/GUSTS.
* MEDIUM CONFIDENCE VFR CONDS WILL PREVAIL.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY THROUGH FRIDAY...PERIODIC CHANCES OF TSRA.
SATURDAY...CHANCE OF SHRA.
RODRIGUEZ
&&
.MARINE...
312 AM CDT
MAIN MARINE CONCERNS IS ON DENSE FOG FOR THE NORTHERN HALF OF THE
LAKE...AND POSSIBLY LINGERING THROUGH MID-WEEK. PERIODIC
THUNDERSTORMS CHANCES ARE EXPECTED THROUGH THE NEXT SEVERAL DAYS
AS WELL.
MINIMAL CHANGES TO PREVIOUS FORECASTS...WITH BROAD RIDGE OF HIGH
PRESSURE ANCHORED OVER THE WESTERN ATLANTIC OCEAN...BEGINNING TO
DRIFT SOUTH THROUGH THE NEXT FEW DAYS. A LOW PRESSURE NEAR LAKE
WINNIPEG WILL DRIFT EAST TOWARDS JAMES BAY TUESDAY MORNING...WHILE
ANOTHER AREA OF LOW PRESSURE STRETCHING FROM SOUTHERN CANADA TO
THE CENTRAL PLAINS BEGINS TO DRIFT NORTHEAST WEDNESDAY. THE
COMBINATION OF THE WESTERN ATLANTIC OCEAN RIDGE AND CENTRAL
PLAINS/CANADIAN LOW...WILL MAINTAIN A GENERALLY SOUTHERLY FLOW OF
WARM/MOIST AIR ACROSS LAKE MICHIGAN. THIS SHOULD KEEP ANY FOG OUT
OF THE SOUTHERN ZONES...HOWEVER AREAS OF DENSE FOG WILL REDEVELOP
FOR THE NORTHERN HALF AND COULD EASILY PERSIST THROUGH MID-WEEK.
HAVE EXTENDED THE MARINE FOG ADVISORY THROUGH DAYBREAK TUE...BUT
COULD EASILY SEE THIS NEEDING TO BE EXTENDED EVEN FURTHER OUT IN
TIME. WINDS WILL GENERALLY BE SOUTHERLY TO AT TIMES
SOUTHWESTERLY...WITH SPEEDS OVERNIGHT IN A 10-15KT RANGE AND
INCREASING TO 15 TO 20 KT DURING THE DAY. WITH ANY THUNDERSTORMS
THAT DEVELOP...WINDS AND WAVES WILL EASILY BE HIGHER IN AND AROUND
THESE THUNDERSTORMS.
A COLD FRONT PUSHES ACROSS THE LAKE DURING WEDNESDAY
NIGHT...SHIFTING WINDS TO OUT OF THE WEST. A SECONDARY COLD FRONT
WILL MOVE ACROSS THE LAKE AND SHIFT WINDS TO OUT OF THE NORTHWEST
DURING LATER THURSDAY AND THURSDAY NIGHT.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ008-ILZ010-ILZ011-ILZ019
UNTIL 7 PM MONDAY.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565
UNTIL 10 AM TUESDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1259 AM CDT MON JUN 24 2013
.DISCUSSION...
723 PM CDT
MADE MINOR TWEAKS TO THE GOING FORECAST. CONVECTION HAS SUBSIDED
WITH SHOWERS FROM CHICAGO THROUGH STREATOR. EXPECTING THE SHOWERS
TO SLOWLY WEAKEN AND MOVE EASTWARD...PRODUCING UP TO AN ADDITIONAL
TENTH OF AN INCH OF PRECIP. THE CONVECTIVE OUTFLOW COOLED AREAS
BUT MOST PLACES HAVE REBOUNDED...SO ADJUSTED TEMPS TRENDS BUT DID
NOT MAKE MAJOR CHANGES TO LOW TEMPS TONIGHT.
AS FAR AS PRECIP CHANCES THROUGH THE REST OF THE NIGHT...MADE
MINOR ADJUSTMENTS BUT THE OVERALL PICTURE REMAINS THE SAME.
EXPECTING CONVECTION TO REFIRE IN THE FOUR CORNERS AREA OF
NE/IA/MO/KS AND SPREAD ACROSS IA OVERNIGHT. STEERING FLOW WOULD
DIRECT THE STORMS TO THE EAST WITH STORMS ENTERING AREAS ALONG AND
WEST OF THE I-39 CORRIDOR AROUND/AFTER 09Z. HOWEVER CONFIDENCE IS
LOW TO MEDIUM IN HOW CONVECTION WILL EVOLVE AND LOW IN TIMING.
HEAVY RAIN IS A DEFINITE CONCERN...BUT DUE TO LOW CONFIDENCE IN
THE CONVECTIVE EVOLUTION I WILL HOLD OFF ISSUING A FLASH FLOOD
WATCH. LIGHTNING...GUSTY WINDS...AND SMALL HAIL ARE ALSO
POSSIBLE...BUT THINKING SEVERE WEATHER WILL BE ISOLATED AT BEST
DUE TO THE ELEVATED NATURE OF THE STORMS.
JEE
//PREV DISCUSSION...
304 PM CDT
SHOWER/THUNDER CHANCES REMAIN THE BIGGEST FORECAST CHALLENGE
FOLLOWED BY TEMPS WHICH MAY BE AFFECTED BY THE CONVECTION. AFTERNOON
WATER VAPOR IMAGERY SHOWS ONE UPPER LEVEL LOW SPINNING OVER THE
CENTRAL APPALACHIANS WHICH IS LOSING DEFINITION AS IS MOVES SLOWLY
NORTHWARD. THE NEXT UPPER LOW IS SPINNING OVER THE SOUTHERN
CANADIAN PRAIRIES WITH A TROUGH AXIS EXTENDING INTO THE DAKOTAS AND
LIFTING NORTHEAST. THE UPPER FLOW IS LESS AMPLIFIED FURTHER SOUTH OF
THE LOW ACROSS THE CENTRAL PLAINS BUT THERE ARE SEVERAL EMBEDDED
WAVES THAT ARE TRANSLATING NORTHEAST AS WELL. THE NEXT UPPER LOW OF
NOTE IS COMING ONSHORE OVER THE WEST COAST AND HELPING TO AMPLIFY A
RIDGE OVER OREGON/WASHINGTON. ENERGY EMANATING FROM THIS TROUGH WILL
BECOME A PLAYER IN OUR WEATHER LATER THIS WEEK. AT THE SURFACE...LOW
PRESSURE IS POSITIONED OVER NORTHWEST MINNESOTA WITH WEAKER LOW
PRESSURE SPREAD ACROSS THE PLAINS. A COOL FRONTAL BOUNDARY IS
STRETCHED FROM THE MN LOW BUT HAS BECOME DIFFICULT TO IDENTIFY
THANKS TO COLD POOLS FROM MORNING CONVECTION.
THROUGH THIS EVENING...TOUGH FORECAST ONCE AGAIN IN TERMS OF
CONVECTIVE POTENTIAL AND EVOLUTION THROUGH THE PERIOD. OUTFLOW
BOUNDARY FROM EARLIER IOWA CONVECTION IS NOW PUSHING INTO THE
WESTERN CWA TRIGGERING THUNDERSTORMS ALONG IT. A BETTER ORGANIZED
COMPLEX OF STORMS HAS DEVELOPED FROM THE EARLIER CONVECTION BUT IS
MOVING SOUTHEAST ACROSS NORTHERN MISSOURI INTO THE AXIS OF MUCH
BETTER INSTABILITY AS WELL AS BETTER MID LEVEL MOISTURE
ADVECTION. ADDITIONAL SCATTERED STORMS HAVE DEVELOPED OVER THE
SOUTHERN CWA LIKELY IN BETTER CONJUNCTION WITH THE WEAKENING UPPER
LOW OVER APPALACHIA. IN THE NEAR TERM...EXPECT THE OUTFLOW TO
CONTINUE EASTWARD ACROSS THE CWA TRIGGERING SCATTERED STORMS THROUGH
LATE AFTERNOON/EARLY EVENING. MESOANALYSIS SHOWS 2000+ J/KG OF MIXED
LAYER CAPE OVER THE AREA SUPPORTING STRONG UPDRAFTS BUT DEEP LAYER
SHEAR IS WEAK SO CORES SHOULD BE PRETTY PULSEY. LARGE HAIL AND
LOCALLY HEAVY DOWNPOURS ARE THE MAIN CONCERN. GUSTY WINDS ARE ALSO
POSSIBLE BUT RECENT AIRCRAFT SOUNDINGS FROM MDW DO NOT SHOW A TON OF
DRY LOW LEVEL AIR AND RAP ANALYSIS OF DCAPE IS LOW AS WELL. WOULD
EXPECT THAT THIS ACTIVITY WOULD WANE WITH SUNSET.
REST OF TONIGHT AND MONDAY...ATTENTION TURNS TO ADDITIONAL
CONVECTIVE POTENTIAL OVERNIGHT. WATER VAPOR SHOWS A WAVE OVER NE
KS/NW MO WHICH APPEARS TO BE TURNING MORE EASTWARD IN THE LAST FEW
SCANS. THIS IS LIKELY HELPING THE COMPLEX TAKING SHAPE OVER MO.
SHORT TERM/HIGH RES GUIDANCE HAS BEEN ALL OVER THE PLACE WITH HOW
CONVECTION EVOLVES THROUGH TONIGHT. THE MOIST SOUTHWESTERLY FLOW
WILL CONTINUE ACROSS THE REGION TONIGHT AND THE EARLIER COLD FRONTAL
BOUNDARY SEEMS TO BE DEVELOPING ONCE AGAIN ACROSS IOWA AS THE FLOW
HAS SETTLED FROM EARLIER CONVECTION. THIS IS SUPPORTIVE OF NEW
DEVELOPMENT TO THE WEST TONIGHT. THE OUTFLOW CURRENTLY WORKING INTO
THE LOCAL AREA EXTENDS INTO WEST-CENTRAL ILLINOIS AND THERE ARE
HINTS THAT THE SOUTHERN EXTENT OF IT AND LIKELY A BOUNDARY SET UP BY
THE CURRENT COMPLEX MAY STALL OUT SOMEWHERE NOT FAR FROM THE
SOUTHWESTERN CWA. IN ADDITION...THE KS/MO WAVE IS EXPECTED TO CROSS
THIS SAME AREA TONIGHT WHICH IS ALSO EXPECTED TO BE IN AN AREA OF
MID LEVEL WARM ADVECTION. THEREFORE IT IS POSSIBLE ROUNDS OF
CONVECTION COULD DEVELOP TO THE SOUTHWEST OF THE AREA AND ROLL
EASTWARD INTO THE SOUTHERN CWA OVERNIGHT. HAVE NOT MADE MUCH CHANGE
TO OVERNIGHT POPS BUT DID INCREASE THEM SOMEWHAT OVER THE FAR SOUTH.
AS FOR MONDAY...GUIDANCE REMAINS IN POOR AGREEMENT WITH TRACK OF
POTENTIAL UPPER WAVES BUT WATER VAPOR DOES SHOW SOME SIGNS OF A WAVE
COMING ACROSS THE FOUR CORNERS THIS AFTERNOON. THIS WOULD COME ACROSS
THE REGION LATER MONDAY BUT IT IS NOT CLEAR IF IT WILL BE MORE
FOCUSED TO THE NORTH OF THE AREA. WILL CONTINUE WITH MID CHANCE POPS
WITH LATER IN THE DAY MORE FAVORED. PROVIDED THE LATER TIMING WORKS
OUT THEN WE WILL HAVE A BETTER CHANCE TO WARM BUT THERE MAY BE
CONVECTIVE DEBRIS AROUND SO WILL HOLD TEMPS INTO THE MID 80S FOR
MOST AREAS.
TUESDAY THROUGH SUNDAY...THE UPPER FLOW BECOMES LESS AMPLIFIED
TUESDAY BUT WILL LIKELY STILL BE LITTERED WITH WAVES TRAVERSING IT.
HOT AND HUMID AIR WILL STILL BE IN PLACE WITH PRECIPITABLE WATER
VALUES HOVERING AROUND 1.75 INCHES. THESE FACTORS PROVIDE CONTINUED
SUPPORT FOR THUNDERSTORM DEVELOPMENT BUT THERE IS NOT MUCH TO KEY IN
ON FOR A COHERENT FORCING MECHANISM GIVEN THE LOW AMPLITUDE PATTERN.
BY WEDNESDAY...THERE IS SOME AGREEMENT ON SURFACE LOW PRESSURE
HAVING DEVELOPED ACROSS THE CANADIAN PRAIRIES WITH A TROUGH
AXIS/FRONT EXTENDING INTO MINNESOTA AND IOWA...WITH A SECONDARY LOW
POSSIBLY DEVELOPING ACROSS MINNESOTA. THE FRONT LOOKS TO CROSS THE
AREA LATER WEDNESDAY BRINGING SHOWER AND STORM CHANCES WITH IT.
UPPER RIDGING WILL BE BUILDING ACROSS THE WESTERN U.S. AND HIGH
PLAINS WITH A WAVE ORIGINATING FROM THE TROUGH OFF THE WEST COAST
OVERTOPPING THE RIDGE ACROSS THE CANADIAN ROCKIES AND DROPPING
SOUTHEASTWARD INTO THE GREAT LAKES WHILE AMPLIFYING LATE IN THE
WEEK. GFS AND ECMWF DIFFER ON HOW QUICKLY THIS OCCURS BUT THE SIGNAL
HAS BEEN CONSISTENT OVERALL. THIS WILL BRING A SHIFT TO
NORTHWESTERLY AT THE SURFACE AND ALOFT LATE IN THE WEEK AND
NOTICEABLY COOLER TEMPERATURES BY SATURDAY OR SO. LOW POPS WILL
CONTINUE WITH THE FLOW CONTINUING TO FAVOR WEAK SHORTWAVE PASSAGES.
HIGH TEMPS WILL LIKELY HOVER AROUND 90 TUESDAY AND WEDNESDAY
ASSUMING CONVECTION OR CONVECTIVE DEBRIS IS NOT AN ISSUE...WHICH
WOULD SIGNIFICANTLY LOWER HIGHS IF IT IS. WITH THE PASSAGE OF THE
SYSTEM LATER WEDNESDAY COOLER MID LEVEL AIR WILL FILTER IN KEEPING
HIGHS BACK IN THE 80S WITH UPPER 70S POSSIBLE FRIDAY AND SATURDAY.
MDB
&&
.HYDROLOGY...
745 PM CDT
THE CONVECTIVE ACTIVITY THIS EVENING PRODUCED ISOLATED AREAS OF 2+
INCHES OF RAIN AND A BAND OF 1+ INCHES OF RAIN ACROSS LA SALLE
COUNTY. STILL CONSIDERED A FLASH FLOOD WATCH FOR THE WEST AND FAR
SOUTHWEST CWA GIVEN THE RAINFALL OF THE PAST FEW DAYS. CONFIDENCE
REMAINS LOW IN WHERE ORGANIZED CONVECTION WILL SET UP TONIGHT AND
MONDAY SO WILL HOLD OFF UNTIL AREAS AND TIMING CAN BE BETTER
DEFINED.
JEE/MDB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* MAINLY SOUTHERLY WINDS ARND 10KT...OCCASIONAL GUSTS LATE
MORNING/AFTN TO 20-24KT. IF TSRA DEVELOP WIND DIR COULD BECOME
VRB FOR A PERIOD OF TIME.
* PRECIP DEVELOPS...LOW COVERAGE EXPECTED LATE THIS MORNING THRU
AFTN.
BEACHLER
//DISCUSSION...UPDATED 06Z...
SIMILAR SETUP AGAIN TODAY AS HAS BEEN THE CASE THE PAST FEW
DAYS...ISOLATED TSRA DEVELOPING. EXPECT MAINLY SOUTHERLY WINDS
ARND 10KT INCREASING WITH GUSTS TO 20-24KT BY LATE MORNING THRU
THE AFTN. THE WILDCARD WILL BE CLOUD COVER WHICH COULD LIMIT HOW
GUSTY WINDS BECOME. THEN THE FOCUS TURNS TOWARDS TIMING OF
PRECIP DEVELOPMENT. EARLY THIS MORNING AN AREA OF SHRA/TSRA WAS
PULSING NORTHEAST...HOWEVER IT DOES NOT APPEAR THIS SHOULD HOLD
TOGETHER AND IMPACT THE TAF SITES. LATER THIS MORNING A WEAK WAVE
DOES TRY TO PUSH OVERHEAD...AND EXPECT SLOW DEVELOPMENT TO
THUNDERSTORMS MIDDAY/AFTN. THE COVERAGE SHOULD BE MINIMAL AND MORE
OF A PULSE LIKE ENVIRONMENT...WHICH COULD POSE A CHALLENGE FOR A
FEW SITES SEEING CHAOTIC WIND DIR/SPEEDS FOR A BRIEF PERIOD OF
TIME IN/AROUND THUNDERSTORMS.
WINDS THEN BEGIN TO DIMINISH TO ARND 5-7KT OVERNIGHT INTO EARLY
TUE...WITH POSSIBLY A REPEAT WITH ISOLATED SHRA/TSRA IN THE AREA
AFT 06Z TUE.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM CONFIDENCE IN TIMING OF SHRA/TSRA DEVELOPMENT.
* HIGH CONFIDENCE IN MAINLY SOUTHERLY WIND SPEEDS/GUSTS.
* MEDIUM CONFIDENCE VFR CONDS WILL PREVAIL.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY THROUGH FRIDAY...PERIODIC CHANCES OF TSRA.
SATURDAY...CHANCE OF SHRA.
RODRIGUEZ
&&
.MARINE...
420 PM CDT
A LARGE AREA OF HIGH PRESSURE EXTENDS FROM THE WESTERN ATLANTIC
SOUTHWESTWARD ACROSS THE SOUTHEASTERN U.S. AND THE NORTHERN GULF
OF MEXICO. THIS HIGH WILL BE MOVING ONLY VERY SLOWLY SOUTHEASTWARD
TONIGHT THROUGH THURSDAY. LOW PRESSURE NEAR LAKE WINNIPEG WILL BE
MOVING SLOWLY EASTWARD ACROSS ONTARIO...REACHING NEAR SOUTHERN JAMES
BAY BY TUESDAY MORNING. THEN...AN AREA OF LOW PRESSURE STRETCHING
FROM THE SOUTHERN CANADIAN PRAIRIE SOUTH ACROSS THE PLAINS WILL MOVE
NORTHEAST DURING TUESDAY AND WEDNESDAY. WITH HIGH PRESSURE SITUATED
FAR TO THE SOUTH THROUGH SOUTHEAST OF THE LAKE AND LOW PRESSURE FROM
FAR WEST THROUGH NORTHWEST TONIGHT INTO THURSDAY...MODERATE TO FRESH
WINDS WILL PERSIST OUT OF THE SOUTH TO SOUTHWEST.
THIS PERSISTENT FLOW WILL KEEP VERY MOIST AIR ACROSS THE WESTERN
GREAT LAKES REGION. WHILE MOST OF THE FOG HAD DISSIPATED ON NORTHERN
LAKE MICHIGAN...WITH THE MOIST AIR AND COOL LAKE WATER FOG IS
EXPECTED TO REDEVELOP TONIGHT AND BECOME DENSE IN AREAS. THE CURRENT
DENSE FOG ADVISORY FOR NORTHERN LAKE MICHIGAN WILL LIKELY NEED TO BE
EXTENDED INTO TUESDAY AND POSSIBLY WEDNESDAY AS THERE WILL BE NO
CHANGE IN AIRMASS UNTIL A COLD FRONT PUSHES ACROSS THE LAKE DURING
LATER WEDNESDAY AND WEDNESDAY NIGHT...SHIFTING WINDS TO OUT OF THE
WEST. A SECONDARY COLD FRONT WILL MOVE ACROSS THE LAKE AND SHIFT
WINDS TO OUT OF THE NORTHWEST DURING LATER THURSDAY AND THURSDAY
NIGHT.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565
UNTIL 7 AM MONDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS TOPEKA KS
726 PM CDT TUE JUN 25 2013
.UPDATE...
ISSUED AT 726 PM CDT TUE JUN 25 2013
HAVE UPDATED THE FORECAST TO TAKE OUT THE SLIGHT CHANCE OF
THUNDERSTORMS FOR THE EARLY EVENING. SURFACE OBS AND LAPS ANALYSIS
SHOWS THE STRONGER LOW LEVEL CONVERGENCE BETWEEN MCPHERSON AND
PRATT ALONG THE SURFACE BOUNDARY. ISOLATED CONVECTION HAS FORMED
IN THIS AXIS OF LOW LEVEL CONVERGENCE. WITH THE LOW LEVEL
MOISTURE FLUX LESS IMPRESSIVE ACROSS NORTH CENTRAL KS AND THE CU
FIELD SHOWING LITTLE VERTICAL DEVELOPMENT OUTSIDE OF THE ENHANCED
CONVERGENCE NEAR HUTCHINSON...THINK ADDITIONAL DEVELOPMENT IS
UNLIKELY AS THE BOUNDARY LAYER STARTS TO STABILIZE WITH THE LOSE
OF DAY TIME HEATING.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 343 PM CDT TUE JUN 25 2013
LATEST WATER VAPOR LOOP SHOWS A WAVE MOVING ACROSS WESTERN KANSAS.
SPEED LOOP OF VISIBLE SATELLITE SHOWS SOME CIRCULATION OVER NORTH
CENTRAL KANSAS WITH A CU FIELD TO ITS EAST AND NORTHEAST. SURFACE
TROUGH FROM A LOW IN SOUTHWEST KANSAS NORTHEAST INTO NEBRASKA.
LATEST MESO ANALYSIS CONTINUES TO SHOW DEEP MOISTURE OVER EASTERN
KANSAS. DEEP MOISTURE CONVERGENCE WAS OCCURRING OVER NORTHEAST AND
NORTH CENTRAL KANSAS AHEAD OF THE ABOVE MENTIONED FEATURE. EML WAS
WORKING ITS WAY ACROSS SOUTH CENTRAL KANSAS THIS AFTERNOON WHERE 15
DEGREE CELSIUS AIR RESIDES.
THE HRRR AND WRF SHOW SOME ISOLATED CONVECTION DEVELOPING NORTH OF
I-70 LATE THIS AFTERNOON AND EVENING IN NORTH CENTRAL AND NORTHEAST
KANSAS. HAVE ONLY ABOUT A 10 TO 15 PERCENT CHANCE OF A THUNDERSTORM
IN THE FORECAST FOR A FEW HOURS THIS EVENING. ATMOSPHERE REMAINS
UNSTABLE WITH LITTLE TO NO CONVECTIVE INHIBITION. 0-6KM SHEAR NEAR
40 KTS SO COULD SEE A SUPERCELL OR TWO DEVELOP. LOW LEVEL JET VEERS
TONIGHT WITH THE DEEPER MOISTURE MOVING OFF TO THE EAST. A COLD
FRONT IN THE WESTERN PLAINS WILL MOVE SOUTHEAST AND ACROSS NORTH
CENTRAL AND NORTHEAST KANSAS LATER TONIGHT THROUGH MID DAY
WEDNESDAY. SURFACE HIGH PRESSURE WILL MOVE IN BEHIND THE FRONT ON
WEDNESDAY. TEMPERATURES WILL BE MILD AGAIN TONIGHT WITH LOWS MAINLY
IN THE 70S. HIGHS ON WEDNESDAY WILL BE IN THE MID 90S IN THE
NORTHEAST CORNER TO NEAR 100 IN NORTH CENTRAL KANSAS. AFTERNOON HEAT
INDICES IN THE 98 TO 104 DEGREE RANGE ARE EXPECTED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 343 PM CDT TUE JUN 25 2013
THE LLVL FLOW VEERS AROUND TO THE SOUTHEAST THEN SOUTH TO SOUTHWEST
WEDNESDAY NIGHT INTO THURSDAY...WARMER AIR AND DEEPER MOISTURE WILL
ADVECT BACK INTO THE COUNTY WARNING AREA. A STRONG 850MB THERMAL
AXIS WILL PUSH WARMER TEMPS NORTHEAST INTO THE CWA...ESPECIALLY THE
SOUTHWEST COUNTIES WHERE HIGHS IN THE 100-103 RANGE SHOULD BE COMMON
AS MIXING ACROSS THE AREA BY AFTERNOON DEEPENS SUBSTANTIALLY. THIS
WILL NOT ONLY RAISE TEMPS...BUT AT THE SAME TIME...LOWER
DEWPOINTS...MAINLY OVER THE WESTERN COUNTIES. HEAT INDICES THURSDAY
WILL COMMONLY BE IN THE 100-105 RANGE. A SUBSTANTIAL EML WILL BE IN
PLACE TO THE START THE AFTERNOON...BUT BY LATE IN THE DAY OVER THE
NORTHERN COUNTIES...IT WILL LIKELY ERODE WITH ISOLATED THUNDERSTORMS
POSSIBLE AND WILL CARRY A SLIGHT CHANCE POP. ALTHOUGH WINDS ALOFT
WILL NOT BE ESPECIALLY STRONG...AN AREA OF HIGH CAPE VALUES AND
INCREASING DIRECTIONAL SHEAR THROUGH 6KM WILL DEVELOP ALONG AND
AHEAD OF THE BOUNDARY SLIPPING SOUTHWARD LATE IN THE DAY AND
EVENING. WOULD EXPECT SOME INCREASE IN COVERAGE OF ANY LATE
AFTERNOON CONVECTION. ALTHOUGH HAIL IS POSSIBLE...A DEEP LAYER OF
NEARLY ADIABATIC LAPSE RATES COULD MAKE STRONG WINDS GUSTS THE
PRIMARY HAZARD FOR ANY CONVECTION THAT MAY DEVELOPS. MODELS SEEM A
FAIRLY GOOD AGREEMENT THAT ANY CONVECTION THAT DEVELOPS...SHOULD BE
SOUTH OF THE CWA BY SUNRISE FRIDAY AS THE BOUNDARY MOVES SOUTHWARD.
WILL KEEP THE HIGHEST POPS OVER THE FAR NORTHEAST/EASTERN COUNTIES.
IT SHOULD ALSO MARK THE BEGINNING OF A GRADUAL DECLINE IN BOTH
TEMPERATURES AND DEWPOINTS AS A LARGE SCALE UPPER TROUGH DEEPENS
THROUGH THE WEEKEND OVER THE EASTERN CONUS. DEWPOINTS WILL COMMONLY
BE IN THE 50S TO NEAR 60 DEGREES THROUGH THE WEEKEND. ALTHOUGH IT
WILL STILL BE THE LOW TO MIDDLE 90S MOST AREAS FRIDAY...HIGHS IN THE
80S WILL BE THE RULE THROUGH THE WEEKEND INTO EARLY NEXT WEEK. WILL
CARRY A SLIGHT CHANCE FOR THUNDERSTORMS OVER THE FAR NORTHEAST ON
SUNDAY. ALTHOUGH CANNOT TOTALLY RULE OUT ISOLATED CONVECTION IN THE
NORTHWEST FLOW REGIME OVER THE AREA...DRIER AIR OVER THE AREA AND
THE LACK OF ANY CONSISTENT FORCING MECHANISM TO DEVELOP PRECIP
WARRANTS KEEPING THE REMAINDER OF THE FCST DRY AT THIS POINT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 545 PM CDT TUE JUN 25 2013
LAPS ANALYSIS AND RAP PROGS SHOW THE BETTER LOW LEVEL CONVERGENCE
ALONG THE SURFACE TROUGH AXIS OVER CENTRAL KS. HOWEVER THERE HAS
NOT BEEN MUCH DEVELOPMENT AT ALL OF A CU FIELD IN CENTRAL KS. SO
THINK THE INHIBITION TO CONVECTION IS HOLDING AND THEREFORE WILL
MAINTAIN A VFR FORECAST WITHOUT ANY MENTION OF PRECIP. THE TROUGH
AXIS SHOULD MOVE THROUGH THE TERMINALS LATE TONIGHT CAUSING SFC
WINDS TO GRADUALLY RELAX.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WOLTERS
SHORT TERM...53
LONG TERM...63
AVIATION...WOLTERS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
400 PM CDT MON JUN 24 2013
...UPDATED FOR SYNOPSIS AND SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 353 PM CDT MON JUN 24 2013
A FAIRLY STRONG SHORTWAVE TROUGH BY LATE JUNE STANDARDS WAS
APPROACHING THE SOUTHERN AND CENTRAL HIGH PLAINS THIS AFTERNOON.
AHEAD OF THIS FEATURE, STRONG SURFACE TROUGH HAD DEVELOPED OVER THE
HIGH PLAINS, WITH STRONG SOUTHERLY WINDS ACROSS SOUTHWEST KANSAS.
ELEVATED CONVECTION IN ADVANCE OF THIS SYSTEM DEVELOPED THIS MORNING
EAST OF DODGE CITY AND THEN MOVED EAST AND WEAKENED. ANOTHER BATCH
OF ELEVATED CONVECTION DEVELOPED WEST OF A SURFACE DRYLINE IN
SOUTHEAST COLORADO AND MOVED INTO FAR SOUTHWEST KANSAS THIS
AFTERNOON. SURFACE BASED CONVECTION HAD NOT YET DEVELOPED AS OF 3
PM.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 353 PM CDT MON JUN 24 2013
THE SHORT RANGE HRRR DOES INDICATE STORMS DEVELOPING IN THE TEXAS
AND OKLAHOMA PANHANDLES THIS AFTERNOON AS UPPER LEVEL FORCING
AIDS IN LOW LEVEL CONVERGENCE ALONG THE DRYLINE. GIVEN THE FAIRLY
STRONG MID LEVEL FLOW FROM THE SOUTHWEST, THIS CONVECTION SHOULD
MOVE NORTHEASTWARD FAIRLY RAPIDLY INTO SOUTHWEST KANSAS THIS
EVENING. SURFACE BASED CAPE VALUES WERE APPROACHING 3000 J/KG FROM
THE TEXAS PANHANDLE INTO SOUTHWEST KANSAS AHEAD OF THE DRYLINE.
0-6 KM BULK SHEAR WAS APPROACHING 40 KTS IN THIS SAME AREA, BUT
LOW LEVEL SHEAR WAS VERY WEAK. GIVEN THE EXPECTED HIGH DEWPOINT
DEPRESSIONS AND RESULTANT HIGH CLOUD BASES, THE STORMS MAY DEVELOP
QUITE A BIT OF OUTFLOW, AND THIS MAY LIMIT THE SEVERITY AS FAR AS
HAIL SIZE IS CONCERNED (SINCE THE STORMS MAY NOT REMAIN AS
SUPERCELL STRUCTURES AS LONG). BUT HAIL AS LARGE AS GOLFBALLS IS
POSSIBLE WITH THE STRONGEST STORMS. IT IS UNCLEAR HOW ORGANIZED
THE STORMS WILL BE AND HOW WIDESPREAD AND HEAVY THE RESULTANT
RAINFALL WOULD BE. BUT STORM CHANCES WERE INCREASED TO 30-40% FOR
PARTS OF SOUTHWEST KANSAS INCLUDING DODGE CITY, JETMORE AND LARNED
GIVEN THE SIGNIFICANT FORCING AND SURFACE BASED CAPE.
AFTER THE AFOREMENTIONED SHORTWAVE TROUGH PASSES TONIGHT AND WITH
THE LOSS OF DAYTIME HEATING, STORM CHANCES WILL DIMINISH RAPIDLY BY
LATE EVENING. THE LOW LEVEL WINDS WILL BEGIN TO VEER AS WELL AND
THIS WILL RESULT IN THE AXIS OF DEEP MOISTURE SHIFTING EASTWARD.
SOUTHWEST WINDS AT 15 KTS EVEN LATE TONIGHT WILL PREVENT TEMPERATURES
FROM DROPPING BELOW THE LOWER 70S AT DODGE CITY, HAYS AND PRATT,
WITH ONLY SLIGHTLY COOLER READINGS NEAR THE COLORADO BORDER.
BEHIND THE SHORTWAVE TROUGH, A WEAK COLD FRONT WILL PROGRESS INTO
CENTRAL KANSAS TUESDAY AFTERNOON, WITH A TRAILING DRYLINE EAST OF
DODGE CITY AND INTO THE PANHANDLES. VERY HOT TEMPERATURES FROM 103
TO 106F ARE EXPECTED IMMEDIATELY BEHIND THE DRYLINE WHERE THE LOW
LEVEL AIR HAS MOVED DOWNSLOPE AND WARMED ADIABATICALLY. ONLY
SLIGHTLY COOLER AIR CAN BE EXPECTED IN FAR WESTERN KANSAS ON THE
HIGHER TERRAIN, AND BEHIND THE WEAK COLD FRONT FROM WAKEENEY TO
DIGHTON. THUNDERSTORMS ARE NOT EXPECTED TUESDAY AFTERNOON GIVEN
THE LACK OF FORCING IN THE WAKE OF THE SHORTWAVE TROUGH AND SINCE
THE LOW LEVEL MOIST AXIS WILL HAVE SHIFTED FURTHER EAST BY THE
TIME OF PEAK HEATING.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 336 PM CDT MON JUN 24 2013
ZONAL FLOW ALOFT WILL BE IN PLACE OVER THE LOWER 48 STATES AT THE
BEGINNING OF THE EXTENDED PERIOD. A SHORTWAVE TROUGH THAT IS NOW
MOVING THROUGH THE GREAT BASIN AND DESERT SOUTHWEST WILL BE EXITING
THE NORTHERN AND CENTRAL PLAINS TUESDAY EVENING. THIS SYSTEM WILL
BRING A WEAK FRONTAL BOUNDARY SOUTH ACROSS WESTERN KANSAS IN ITS
WAKE LATE TUESDAY AFTERNOON AND EVENING. PRECIPITATION CHANCES LOOK
FAIRLY SMALL GIVEN THE LACK OF UPPER SUPPORT AND A FAIRLY DRY
AIRMASS.
THROUGH THE MIDDLE PART OF THE WEEK, 500 MILLIBAR HEIGHTS WILL BE
BUILDING OVER THE WESTERN AND CENTRAL PART OF THE COUNTRY. WITH
INCREASING THICKNESS VALUES OVER WESTERN KANSAS WE SHOULD SEE
DAYTIME HIGH TEMPERATURES WARMING BACK UP TO AROUND OR ABOVE 100
DEGREES ESPECIALLY BY THURSDAY. THE UPPER RIDGE BECOMES MORE
AMPLIFIED OVER WESTERN NORTH AMERICA TOWARD THE UPCOMING WEEKEND
WITH UPPER LEVEL FLOW BECOMING MORE NORTHWESTERLY OVER THE CENTRAL
PLAINS. A WEAK FRONTAL BOUNDARY IS FORECAST TO MOVE SOUTH THROUGH
THE CENTRAL HIGH PLAINS EARLY FRIDAY WITH EASTERLY UPSLOPE FLOW
SETTING UP INTO THE EASTERN SLOPES OF THE ROCKIES. AFTERNOON
THUNDERSTORMS SHOULD DEVELOP OFF THE FRONT RANGE. GIVEN THE UPPER
LEVEL FLOW, SOME OF THESE COULD MOVE INTO FAR WESTERN KANSAS FRIDAY
EVENING.
THE UPPER LEVEL FLOW OVER THE CENTRAL PART OF THE COUNTRY BECOMES
EVEN MORE MERIDIONAL THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK.
THE MEDIUM RANGE MODELS HAVE ALL BEEN TRENDING IN THIS DIRECTION
THROUGH THE PAST FEW RUNS. THINK THAT THE CURRENT WEEK TWO OUTLOOK
SHOULD BE TRENDED BACK TO AT LEAST NEAR NORMAL TEMPERATURES FOR NOW
BUT BASED ON FORECAST TEMPERATURES, WE COULD BE EVEN COOLER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1256 PM CDT MON JUN 24 2013
A TROUGH OF LOW PRESSURE IN THE LEE OF THE ROCKIES WILL LEAD TO
STRONG SOUTH WINDS THROUGH TONIGHT, WITH 20-25 KTS TODAY AND 15KTS
TONIGHT. THE WINDS WILL GRADUALLY WEAKEN AND SHIFT TO THE WEST
AFTER 12Z TUESDAY AS THE SURFACE TROUGH PROGRESSES EASTWARD INTO
WESTERN KANSAS. THERE IS A SMALL CHANCE OF A THUNDERSTORM NEAR
KHYS AND KDDC THIS AFTERNOON AND EVENING. VFR CONDITIONS WILL
PERSIST ASIDE FROM THUNDERSTORMS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 74 105 69 101 / 40 0 0 0
GCK 72 104 65 101 / 20 0 0 0
EHA 70 103 66 101 / 10 0 0 0
LBL 74 105 68 104 / 20 0 0 0
HYS 74 104 70 101 / 30 0 0 0
P28 74 100 74 101 / 20 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 8 PM CDT THIS EVENING FOR KSZ030-031-043>046-
062>066-075>081-085>090.
RED FLAG WARNING UNTIL 9 PM CDT /8 PM MDT/ THIS EVENING FOR
KSZ061-062-074.
&&
$$
SYNOPSIS...FINCH
SHORT TERM...FINCH
LONG TERM...GERARD
AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1252 PM CDT MON JUN 24 2013
.UPDATE...
ISSUED AT 1251 PM CDT MON JUN 24 2013
UPDATED THE FORECAST TO ADD SCATTERED THUNDERSTORMS FOR MUCH OF
THE AREA FOR THE REST OF THE AFTERNOON. A SMALL WAVE WAS MOVING
NORTHEAST OUT OF NEW MEXICO AND HAS SUSTAINED CONVECTION FROM
SOUTHWEST KANSAS INTO NORTHEAST KANSAS. ATMOSPHERE REMAINS
UNSTABLE WITH PLENTY OF MOISTURE. WATER VAPOR SATELLITE SHOWING A
MOISTURE STREAMING NORTHEAST FROM MEXICO.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CDT MON JUN 24 2013
ANOTHER DIFFICULT FORECAST AS MESOSCALE FEATURES CONTINUE TO DEFINE
CONVECTIVE POTENTIAL...AND ARE DIFFICULT TO FORECAST MORE THAN A FEW
HOURS OUT. FOR TODAY...SOUNDINGS SUGGEST WAVE LIFTING OUT OF
OK/CTRL KS MAY SATURATE MID LEVELS ENOUGH TO SUPPORT SOME ISOLATED
CONVECTION THIS MORNING...AND WILL LEAVE AN ISOLATED POP TO REFLECT
THIS. HRRR MODEL...WHICH HAS PERFORMED WELL IN THE MORNING RUNS THIS
WEEK...DEPICTS CONVECTIVE COMPLEX OVER SC NEBRASKA SLIDING SLIGHTLY
TO THE SE AND BACK-BUILD INTO OUR FORECAST AREA LATER THIS
MORNING. FRONTAL BOUNDARY HAS SHIFTED FARTHER NORTHWARD AND SUSPECT
COMPLEX WILL STAY NORTH OF THE FA. ALSO SHOULD CONSIDER OUTFLOW
MOVING SE OUT OF IOWA CONVECTION AND WHERE THAT MAY END UP ON THE
KS/MO BORDER THIS AFTERNOON. AT THIS TIME LESS CINH AND BETTER
DYNAMICS COME TOGETHER NORTH OF THE AREA. HAVE STARTED WITH A SILENT
POP IN THE NE COUNTIES AND WILL MONITOR FOR DEVELOPMENT. BREEZY
SOUTHERLY WINDS WILL BE NEAR BUT GENERALLY BELOW WIND ADVISORY
CRITERIA AND WILL HOLD OFF FOR NOW. HIGHS TODAY IN THE 90S FOLLOWED
BY WARM OVERNIGHT LOWS IN THE MIDDLE 70S. WITH ANOTHER COMPLEX
MOVING NORTH OF THE FORECAST AREA LATE MONDAY INTO EARLY
TUESDAY...WILL CARRY A SLIGHT CHANCE POP ACROSS THE FAR NORTHERN
COUNTIES AS MAY SEE SOME LATE NIGHT COLD POOL LLJ INTERACTION. 67
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 352 AM CDT MON JUN 24 2013
MID RANGE AND EXTENDED FORECAST (TUESDAY THROUGH SUNDAY)...
WARM...MUGGY...AND DRY CONDITIONS EXPECTED TO PERSIST THROUGH MOST OF
THE MID RANGE AND EXTENDED PERIOD. FOR TUESDAY AND WEDNESDAY THE MID
LEVEL RIDGE GETS SOMEWHAT FLATTENED OUT AND DEAMPLIFIED AS THE HIGH
PRESSURE EXPANDS ACROSS THE SOUTHERN PLAINS. EVENTUALLY...BY MID
WEEK THE RIDGE WILL BECOME CENTERED OVER THE FOUR CORNERS REGION OF
THE US...AND WILL BECOME MOVE AMPLIFIED AS THE WEEK PROGRESSES. WITH
THE EASTERN EDGE OF THE HIGH PRESSURE DOME IN THE VICINITY OF
NORTHEAST KANSAS EXPECT SOME MID LEVEL NWLY FLOW TO REMAIN OVER THE
FORECAST AREA...WHICH WILL BRING THE POTENTIAL FOR MCS DEVELOPMENT
WITHIN THE FLOW. FOR NOW WILL KEEP A MOSTLY DRY FORECAST THROUGH THE
EXTENDED PERIOD...WITH THE LONE EXCEPTION OF THURSDAY NIGHT WHERE
THE ECMWF AND GFS AGREE ON THUNDERSTORMS DEVELOPING ALONG THE
PERIPHERY OF THE RIDGE AND DROPPING SOUTH/SOUTHEASTWARD OUT OF SE
NEBRASKA INTO NE KANSAS. GIVEN THE LACK OF ANY STRONG SIGNAL OF
OBVIOUS LIFTING MECHANISMS WILL ONLY GO WITH A SLIGHT CHANCE FOR
SHOWERS AND THUNDERSTORMS FOR THAT PERIOD. OTHERWISE...EXPECT A
RATHER WARM AND MUGGY PERIOD FOR TUES THROUGH THURS AS DAY TIME
HIGHS WILL GENERALLY REACH THE MID TO UPPER 90S...WITH HEAT INDEX
VALUES RANGING BETWEEN 100 AND 105 ACROSS MOST OF THE FORECAST AREA.
TEMPERATURES WILL COOL OFF A BIT FOR THE END OF THE WORK WEEK
THROUGH THE WEEKEND...AS A SURFACE HIGH BRINGS COOLER AIR INTO
NORTHEAST KANSAS. EXPECT TEMPS FOR FRIDAY THROUGH MONDAY TO BE IN
THE UPPER 80S TO PERHAPS THE MID 90S.
JL
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1251 PM CDT MON JUN 24 2013
VFR CONDITIONS EXPECTED OUTSIDE OF CONVECTIVE ACTIVITY THROUGH THE
PERIOD. SOUTH WINDS WILL CONTINUE NEAR 16 KTS WITH HIGHER GUSTS.
CONVECTIVE OUTFLOW BOUNDARIES WILL AFFECT THE WIND DIRECTION AND
SPEED. ADDED VCTS FOR SCATTERED CONVECTION THAT MAY LAST UNTIL
23Z. WINDS WILL DECREASE SOME TONIGHT THEN INCREASE AGAIN AFTER
14Z TUESDAY.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...53
SHORT TERM...CRAVEN
LONG TERM...LEIGHTON
AVIATION...53
AREA FORECAST DISCUSSION
NWS TOPEKA KS
629 AM CDT MON JUN 24 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CDT MON JUN 24 2013
ANOTHER DIFFICULT FORECAST AS MESOSCALE FEATURES CONTINUE TO DEFINE
CONVECTIVE POTENTIAL...AND ARE DIFFICULT TO FORECAST MORE THAN A FEW
HOURS OUT. FOR TODAY...SOUNDINGS SUGGEST WAVE LIFTING OUT OF
OK/CTRL KS MAY SATURATE MID LEVELS ENOUGH TO SUPPORT SOME ISOLATED
CONVECTION THIS MORNING...AND WILL LEAVE AN ISOLATED POP TO REFLECT
THIS. HRRR MODEL...WHICH HAS PERFORMED WELL IN THE MORNING RUNS THIS
WEEK...DEPICTS CONVECTIVE COMPLEX OVER SC NEBRASKA SLIDING SLIGHTLY
TO THE SE AND BACK-BUILD INTO OUR FORECAST AREA LATER THIS
MORNING. FRONTAL BOUNDARY HAS SHIFTED FARTHER NORTHWARD AND SUSPECT
COMPLEX WILL STAY NORTH OF THE FA. ALSO SHOULD CONSIDER OUTFLOW
MOVING SE OUT OF IOWA CONVECTION AND WHERE THAT MAY END UP ON THE
KS/MO BORDER THIS AFTERNOON. AT THIS TIME LESS CINH AND BETTER
DYNAMICS COME TOGETHER NORTH OF THE AREA. HAVE STARTED WITH A SILENT
POP IN THE NE COUNTIES AND WILL MONITOR FOR DEVELOPMENT. BREEZY
SOUTHERLY WINDS WILL BE NEAR BUT GENERALLY BELOW WIND ADVISORY
CRITERIA AND WILL HOLD OFF FOR NOW. HIGHS TODAY IN THE 90S FOLLOWED
BY WARM OVERNIGHT LOWS IN THE MIDDLE 70S. WITH ANOTHER COMPLEX
MOVING NORTH OF THE FORECAST AREA LATE MONDAY INTO EARLY
TUESDAY...WILL CARRY A SLIGHT CHANCE POP ACROSS THE FAR NORTHERN
COUNTIES AS MAY SEE SOME LATE NIGHT COLD POOL LLJ INTERACTION. 67
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 352 AM CDT MON JUN 24 2013
MID RANGE AND EXTENDED FORECAST (TUESDAY THROUGH SUNDAY)...
WARM...MUGGY...AND DRY CONDITIONS EXPECTED TO PERSIST THROUGH MOST OF
THE MID RANGE AND EXTENDED PERIOD. FOR TUESDAY AND WEDNESDAY THE MID
LEVEL RIDGE GETS SOMEWHAT FLATTENED OUT AND DEAMPLIFIED AS THE HIGH
PRESSURE EXPANDS ACROSS THE SOUTHERN PLAINS. EVENTUALLY...BY MID
WEEK THE RIDGE WILL BECOME CENTERED OVER THE FOUR CORNERS REGION OF
THE US...AND WILL BECOME MOVE AMPLIFIED AS THE WEEK PROGRESSES. WITH
THE EASTERN EDGE OF THE HIGH PRESSURE DOME IN THE VICINITY OF
NORTHEAST KANSAS EXPECT SOME MID LEVEL NWLY FLOW TO REMAIN OVER THE
FORECAST AREA...WHICH WILL BRING THE POTENTIAL FOR MCS DEVELOPMENT
WITHIN THE FLOW. FOR NOW WILL KEEP A MOSTLY DRY FORECAST THROUGH THE
EXTENDED PERIOD...WITH THE LONE EXCEPTION OF THURSDAY NIGHT WHERE
THE ECMWF AND GFS AGREE ON THUNDERSTORMS DEVELOPING ALONG THE
PERIPHERY OF THE RIDGE AND DROPPING SOUTH/SOUTHEASTWARD OUT OF SE
NEBRASKA INTO NE KANSAS. GIVEN THE LACK OF ANY STRONG SIGNAL OF
OBVIOUS LIFTING MECHANISMS WILL ONLY GO WITH A SLIGHT CHANCE FOR
SHOWERS AND THUNDERSTORMS FOR THAT PERIOD. OTHERWISE...EXPECT A
RATHER WARM AND MUGGY PERIOD FOR TUES THROUGH THURS AS DAY TIME
HIGHS WILL GENERALLY REACH THE MID TO UPPER 90S...WITH HEAT INDEX
VALUES RANGING BETWEEN 100 AND 105 ACROSS MOST OF THE FORECAST AREA.
TEMPERATURES WILL COOL OFF A BIT FOR THE END OF THE WORK WEEK
THROUGH THE WEEKEND...AS A SURFACE HIGH BRINGS COOLER AIR INTO
NORTHEAST KANSAS. EXPECT TEMPS FOR FRIDAY THROUGH MONDAY TO BE IN
THE UPPER 80S TO PERHAPS THE MID 90S.
JL
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 626 AM CDT MON JUN 24 2013
EXPECT ANOTHER DAY WITH BREEZY SOUTH WINDS AND VCTS AT TIMES. HAVE
CARRIED 14Z AT MHK WITH 15Z AT TOP/FOE THEN ENDING LATER AFTERNOON
HOURS. KEPT WIND SPEEDS UP OVERNIGHT BUT WILL LIKELY NEED TO BRING
GUSTS OUT FOR A LATER PERIOD NEXT TAF ISSUANCE.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CRAVEN
LONG TERM...LEIGHTON
AVIATION...67
AREA FORECAST DISCUSSION
NWS TOPEKA KS
406 AM CDT MON JUN 24 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CDT MON JUN 24 2013
ANOTHER DIFFICULT FORECAST AS MESOSCALE FEATURES CONTINUE TO DEFINE
CONVECTIVE POTENTIAL...AND ARE DIFFICULT TO FORECAST MORE THAN A FEW
HOURS OUT. FOR TODAY...SOUNDINGS SUGGEST WAVE LIFTING OUT OF
OK/CTRL KS MAY SATURATE MID LEVELS ENOUGH TO SUPPORT SOME ISOLATED
CONVECTION THIS MORNING...AND WILL LEAVE AN ISOLATED POP TO REFLECT
THIS. HRRR MODEL...WHICH HAS PERFORMED WELL IN THE MORNING RUNS THIS
WEEK...DEPICTS CONVECTIVE COMPLEX OVER SC NEBRASKA SLIDING SLIGHTLY
TO THE SE AND BACK-BUILD INTO OUR FORECAST AREA LATER THIS
MORNING. FRONTAL BOUNDARY HAS SHIFTED FARTHER NORTHWARD AND SUSPECT
COMPLEX WILL STAY NORTH OF THE FA. ALSO SHOULD CONSIDER OUTFLOW
MOVING SE OUT OF IOWA CONVECTION AND WHERE THAT MAY END UP ON THE
KS/MO BORDER THIS AFTERNOON. AT THIS TIME LESS CINH AND BETTER
DYNAMICS COME TOGETHER NORTH OF THE AREA. HAVE STARTED WITH A SILENT
POP IN THE NE COUNTIES AND WILL MONITOR FOR DEVELOPMENT. BREEZY
SOUTHERLY WINDS WILL BE NEAR BUT GENERALLY BELOW WIND ADVISORY
CRITERIA AND WILL HOLD OFF FOR NOW. HIGHS TODAY IN THE 90S FOLLOWED
BY WARM OVERNIGHT LOWS IN THE MIDDLE 70S. WITH ANOTHER COMPLEX
MOVING NORTH OF THE FORECAST AREA LATE MONDAY INTO EARLY
TUESDAY...WILL CARRY A SLIGHT CHANCE POP ACROSS THE FAR NORTHERN
COUNTIES AS MAY SEE SOME LATE NIGHT COLD POOL LLJ INTERACTION. 67
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 352 AM CDT MON JUN 24 2013
MID RANGE AND EXTENDED FORECAST (TUESDAY THROUGH SUNDAY)...
WARM...MUGGY...AND DRY CONDITIONS EXPECTED TO PERSIST THROUGH MOST OF
THE MID RANGE AND EXTENDED PERIOD. FOR TUESDAY AND WEDNESDAY THE MID
LEVEL RIDGE GETS SOMEWHAT FLATTENED OUT AND DEAMPLIFIED AS THE HIGH
PRESSURE EXPANDS ACROSS THE SOUTHERN PLAINS. EVENTUALLY...BY MID
WEEK THE RIDGE WILL BECOME CENTERED OVER THE FOUR CORNERS REGION OF
THE US...AND WILL BECOME MOVE AMPLIFIED AS THE WEEK PROGRESSES. WITH
THE EASTERN EDGE OF THE HIGH PRESSURE DOME IN THE VICINITY OF
NORTHEAST KANSAS EXPECT SOME MID LEVEL NWLY FLOW TO REMAIN OVER THE
FORECAST AREA...WHICH WILL BRING THE POTENTIAL FOR MCS DEVELOPMENT
WITHIN THE FLOW. FOR NOW WILL KEEP A MOSTLY DRY FORECAST THROUGH THE
EXTENDED PERIOD...WITH THE LONE EXCEPTION OF THURSDAY NIGHT WHERE
THE ECMWF AND GFS AGREE ON THUNDERSTORMS DEVELOPING ALONG THE
PERIPHERY OF THE RIDGE AND DROPPING SOUTH/SOUTHEASTWARD OUT OF SE
NEBRASKA INTO NE KANSAS. GIVEN THE LACK OF ANY STRONG SIGNAL OF
OBVIOUS LIFTING MECHANISMS WILL ONLY GO WITH A SLIGHT CHANCE FOR
SHOWERS AND THUNDERSTORMS FOR THAT PERIOD. OTHERWISE...EXPECT A
RATHER WARM AND MUGGY PERIOD FOR TUES THROUGH THURS AS DAY TIME
HIGHS WILL GENERALLY REACH THE MID TO UPPER 90S...WITH HEAT INDEX
VALUES RANGING BETWEEN 100 AND 105 ACROSS MOST OF THE FORECAST AREA.
TEMPERATURES WILL COOL OFF A BIT FOR THE END OF THE WORK WEEK
THROUGH THE WEEKEND...AS A SURFACE HIGH BRINGS COOLER AIR INTO
NORTHEAST KANSAS. EXPECT TEMPS FOR FRIDAY THROUGH MONDAY TO BE IN
THE UPPER 80S TO PERHAPS THE MID 90S.
JL
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1101 PM CDT SUN JUN 23 2013
VFR IS THE PREVAILING CATEGORY AT KTOP/KFOE/KMHK AS SOUTH
SOUTHEAST WINDS REMAIN STEADY AROUND 10 KTS. CONVECTION FORMING
OVER FAR EASTERN COLORADO MAY ORGANIZE INTO A THUNDERSTORM COMPLEX
AND ENTER THE AREA AFT 11Z. INSERTED A VCTS ATTM AS EXACT TIMING
OF THE TSRA IS STILL UNCERTAIN. GUSTS INCREASE UP TO 30 KTS AFT
14Z MONDAY.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CRAVEN
LONG TERM...LEIGHTON
AVIATION...BOWEN
AREA FORECAST DISCUSSION...UPDATED
NWS PADUCAH KY
635 PM CDT TUE JUN 25 2013
.UPDATE...
ISSUED AT 630 PM CDT TUE JUN 25 2013
UPDATED THE AVIATION SECTION FOR THE 00Z TAF ISSUANCE.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 325 PM CDT TUE JUN 25 2013
A FEW ISOLATED THUNDERSTORMS WILL BE POSSIBLE THROUGH SUNSET OVER
THE ENTIRE AREA...BUT THE PRIMARY FOCUS LOOKS TO BE ALONG THE
NORTHWEST PERIPHERY OF THE AREA AND FARTHER NORTH LATE THIS
AFTERNOON. ANY ACTIVITY TO OUR NORTH WOULD LIKELY MOVE
EASTWARD...BUT COULD BUILD SOUTHWARD INTO OUR FAR NORTH OR
NORTHEAST COUNTIES THIS EVENING. LEFT A SLIGHT CHANCE THROUGH THE
EVENING ALONG THE NORTHEAST PERIPHERY OF THE AREA. DUE TO THE
EXTREME INSTABILITY ACROSS THE AREA...A FEW STORMS COULD BRIEFLY
PULSE UP TO PRODUCE MARGINALLY SEVERE HAIL OR WINDS...BUT THE
PRIMARY CONCERN WILL BE LOCALLY HEAVY RAINFALL.
THE LATEST HRRR AND 12Z WRF RUNS INDICATE THAT AN MCS MAY BE
APPROACHING THE AREA FROM THE NORTHWEST BY 12Z. THE FLOW ALOFT
WILL BEGIN TO SHIFT TO THE NORTHWEST TONIGHT...SO THIS GENERAL
SYSTEM MOVEMENT IS LIKELY. THE MODELS GENERALLY WEAKEN THE SYSTEM
AS IT ENCOUNTERS THE WEAKER FLOW OVER OUR AREA. IT IS NOT CERTAIN
WHETHER THE ACTIVE CONVECTION WILL REACH THE AREA...BUT AN OUTFLOW
BOUNDARY WILL AT LEAST GET VERY CLOSE TO THE AREA.
TWO THINGS TO CONSIDER HERE ARE THE POTENTIAL FOR THE OLD COLD POOL
TO SURGE INTO THE AREA...MUDDLING UP THE OTHERWISE HOT...HUMID AND
BREEZY DAY THAT IS CURRENTLY FORECAST...AND THE POTENTIAL FOR THE
OUTFLOW TO FOCUS NEW THUNDERSTORM DEVELOPMENT OR JUST RE-INTENSIFY
OVER OUR AREA DURING THE DAY.
THE MODELS HAVE CONSISTENTLY INDICATED INCREASING SHEAR THROUGH
THE DAY FROM THE NORTHWEST...AND DEVELOPED RATHER EXTREME
INSTABILITY SOUTH OF ANY OUTFLOWS IN THE AFTERNOON.
THEREFORE...WOULD NOT EXPECT ANY CONVECTION THROUGH THE MORNING TO
POSE MORE THAN A HEAVY RAIN THREAT. HOWEVER...NO MATTER THE MEANS
OF GENERATION...STORMS LATER INTO THE AFTERNOON AND THROUGH THE
EVENING WILL LIKELY POSE A LARGE HAIL AND DAMAGING WIND THREAT.
THE STORMS WILL MOVE TO THE SOUTHEAST...AND ANY RIGHT MOVING
STORMS MAY MOVE DUE SOUTH OR EVEN SOUTHWEST.
IN THE ABSENCE OF A MAJOR COLD POOL INVASION EARLY WEDNESDAY...A
LAKE WIND ADVISORY AND POSSIBLY A HEAT ADVISORY WILL BE NEEDED
THROUGH THE DAY. WILL NOT ISSUE EITHER AT THIS TIME DUE TO THE
UNCERTAINTIES IN THE OVERNIGHT CONVECTIVE FORECAST. PRESUMABLY IT
WILL BE A CLEARER DECISION FOR THE MIDNIGHT SHIFT.
AS FOR TEMPERATURES...WENT ON THE MILD SIDE OF MOST GUIDANCE FOR
TONIGHT...AND EVEN WEDNESDAY NIGHT GIVEN NO SIGN OF SIGNIFICANT DRY
ADVECTION INTO THE AREA. HIGHS ON WEDNESDAY ARE LIKELY TO BE A
REAL PAIN. TRIED TO KEEP IT HOT IN THE WEST AND COOL IT DOWN A BIT
IN THE EAST CLOSER TO ANY ALL DAY OUTFLOW/CONVECTION POTENTIAL.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 325 PM CDT TUE JUN 25 2013
THIS EXTENDED PERIOD ESSENTIALLY STARTS FOLLOWING THE PASSAGE OF THE
CLOSED LOW THROUGH THE GREAT LAKES AND THE APPROACH OF THE WESTERN
U.S. RIDGE. THE WFO PAH AREA IS POISED ON THE SOUTHERN EDGE OF THE
BAROCLINIC ZONE EMBEDDED IN FAST NORTHWEST FLOW. THE PENNYRILE
REGION OF WEST KENTUCKY AND SOUTHWEST INDIANA ARE ON THE WEST EDGE
OF THE FOCUSED LIFT/STRETCHING OF PARCELS...SO KEPT A SMALL MENTION
OF THUNDERSTORMS IN THAT AREA. THE SHORT RANGE ENSEMBLE /SREF/
SUGGESTS THAT THERE WILL BE A WEAK BOUNDARY INTERACTION ALONG THE
SOUTHERN SECTIONS OF THE WFO PAH FORECAST AREA INTO THURSDAY NIGHT
/MAINLY OVER SOUTHEAST MISSOURI AND WEST KENTUCKY/ TANGENTIAL TO THE
FASTER NORTHWEST FLOW. WITH THIS IN MIND...KEPT A SMALL CHANCE OF
THUNDERSTORMS ADJACENT TO THE BOUNDARY.
FROM FRIDAY INTO FRIDAY EVENING...ALTHOUGH THE SURFACE FLOW IS
NORTHWEST...THERE IS SOME DIFFERENTIAL SPEED SHEAR AND LOW LEVEL
THERMAL GRADIENT ALONG THE SOUTHERN EDGE OF THE WESTERLIES...WITH
MEAGER LOW/MID LEVEL MOISTURE IN THE WFO PAH FORECAST AREA. AT THIS
TIME...NOT REAL CONFIDENT THAT THERE WILL BE MUCH GREATER THAN
WIDELY SCATTERED COVERAGE FOR CONVECTION...SO POPS/WEATHER ARE A
LITTLE LOWER THAN SURROUNDING NWS OFFICES AT THIS TIME.
THE GFS/GFS ENSEMBLE TAKES THE PREVIOUSLY MENTIONED GREAT LAKES LOW
AND ROTATE ANOTHER SHORTWAVE AROUND THE LOW DOWN THROUGH THE UPPER
MIDWEST ON SATURDAY. WITH THIS NEXT SHORTWAVE...THERE IS SOME
SUPPORT FOR ELEVATED CONVECTION BY NEXT SUNDAY. FROM MONDAY INTO
TUESDAY...AS THE LOW SHARPENS OVER THE WFO PAH FORECAST
AREA...INTRODUCED A CHANCE FOR CONVECTION ALONG THE EASTERN LIMB OF
THE SHARPENING TROUGH...MAINLY OVER THE PENNYRILE REGION OF WEST
KENTUCKY AND SOUTHWEST INDIANA. THERE WOULD BE A SLIGHT TEMPORAL
SHIFT WESTWARD AS IMPULSES WORK THROUGH THE BASE OF THE TROUGH.
TEMPERATURE-WISE...THERE WILL BE SOME VARIANCE AS THE THE SOUTHERN
LIMIT OF THE ANTECEDENT CONVECTION WEDNESDAY AND WEDNESDAY
NIGHT...ALONG WITH THE POSITION OF THE EFFECTIVE BOUNDARY OVER THE
WFO PAH FORECAST AREA. AT THIS TIME...LEANED TOWARD THE SREF
SOLUTION. THIS WILL PLACE A SHARP THERMAL GRADIENT OVER SOUTHEAST
MISSOURI...WITH HIGH TEMPERATURES EXPECTED TO TOP OUT INTO THE UPPER
90S...WITH WIDESPREAD HEAT INDEX VALUES BETWEEN 100 AND 105 DEGREES
ALONG AND WEST OF THE MISSISSIPPI RIVER. BEYOND THURSDAY...
TEMPERATURES SHOULD REMAIN AT OR BELOW NORMAL WITH HIGHS FALLING
BACK INTO THE 80S.
&&
.AVIATION...
ISSUED AT 630 PM CDT TUE JUN 25 2013
FOR THE MOST PART VFR CONDITIONS EXPECTED AT ALL SITES THROUGH THE
PERIOD. VCTS POSSIBLE AT ALL SITES AFT 15Z AND POSSIBLE MVFR VSBYS
IN TSRA AT KEVV/KOWB BETWEEN 15-22Z. SOUTH SOUTHWEST WINDS OVERNIGHT
AOB 10 KTS WILL INCREASE TO 13-15 KTS WITH GUSTS UP TO 25 KTS AFT 15Z.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM/AVIATION...JP
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1052 AM CDT MON JUN 24 2013
.MESOSCALE DISCUSSION...
ISSUED AT 1052 CDT MON JUN 24 2013
IR AND VISIBILE SATELLITE...AS WELL AS KVWX RADAR IMAGERY SUGGEST
A SMALL MESOSCALE VORTEX/SMALL SCALE TROUGH OVER SOUTHWEST INDIANA
NEAR KEVV BETWEEN 14Z-15Z. THIS FEATURE SHOULD ENGAGE ENOUGH LIFT
TO SUPPORT LOCALIZED UPDRAFTS CAPABLE OF PRODUCING SMALL HAIL
/POSSIBLY UP TO NICKLE SIZE/ ALONG AND TO THE EAST AND SOUTHEAST
OF THE VORTEX...LEADING INTO THE REMAINDER OF SOUTHWEST INDIANA
AND THE PENNYRILE REGION OF WEST KENTUCKY THIS MORNING.
ALSO...GIVEN THE SLOW MOVEMENT OF THIS FEATURE /LESS THAN 12
KNOTS/...AND PRECIPITABLE WATER VALUES AROUND TWO INCHES...WOULD
NOT BE SURPRISED TO SEE MINIMUM HOURLY RAINFALL VALUES BETWEEN
0.80 AND 1.10 INCHES IN THE HEAVIER RAINFALL CORES. WITH THIS IN
MIND...ADDED A MENTION OF SMALL HAIL/HEAVY RAIN TO THE HIGHEST POP
CATEGORY AREA FOR THE REMAINDER OF THE MORNING AND INTO THE EARLY
AFTERNOON MAINLY FOR HEAVY RAIN.
FURTHER TO THE WEST...THETA-E CONVERGENCE OVER SOUTHEAST MO SHOULD
CONTINUE TO EVOLVE IN THE WEEK CONVERGENT FLOW...JUST EAST OF THE
SOUTHEAST MO FOOTHILLS. SURFACE BASED INSTABILITY WILL REMAIN
HIGH...SO ANTICIPATE SOME ISOLATED DEVELOPMENT DURING THE
AFTERNOON OVER THE SOUTHEAST MISSOURI FOOTHILL INTO SOUTHWEST
ILLINOIS...MAINLY WEST OF INTERSTATE 57.
AM ALSO CONCERNED WITH DIFFERENTIAL HEATING AND AN INSTABILITY
GRADIENT WEST OF THE CURRENT CONVECTION THIS AFTERNOON...WITH WEAK
SURFACE CONVERGENCE LEADING TO AT LEAST SOME RENEWED...BUT BRIEF
DEVELOPMENT FROM THE LAND BETWEEN THE LAKES NORTHWARD TO THE
CONFLUENCE OF THE OHIO/WABASH RIVER...WEST OF THE CURRENT
CONVECTIVE ACTIVITY THIS MORNING. THE 3KM HRRR AND 4KM NAM-WRF
/NMM VERSION/ SEEM TO PICK UP ON THESE FEATURES AND SO TRIED TO
ADJUST ACCORDINGLY.
AN URBAN AND SMALL STREAM FLOOD ADVISORY WILL LIKELY BE POSTED FOR
THOSE COUNTIES ALONG AND EITHER SIDE OF THE MCV THIS MORNING AND
INTO THE EARLY AFTERNOON TO ACCOUNT FOR THE EFFICIENT RAINFALL
WITH THE STRONGER THUNDERSTORM CORES.
&&
.UPDATE...
ISSUED AT 643 AM CDT MON JUN 24 2013
UPDATED AVIATION DISCUSSION FOR 12Z TAFS.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 354 AM CDT MON JUN 24 2013
WEAK FLOW PATTERN WILL PERSIST ACROSS MUCH OF THE SOUTHERN AND
EASTERN U.S. THROUGH MID WEEK. AS A RESULT...MUCH OF THE LOCAL
WEATHER PATTERN WILL BE DRIVEN BY MESOSCALE INFLUENCES TYPICALLY
NOT HANDLED WELL BY OPERATIONAL MODELS. THE MAIN INFLUENCE TODAY
APPEARS TO BE AN MCV CURRENTLY DRIVING CONVECTIVE ACTIVITY OVER
SOUTHEAST ILLINOIS AND SOUTHWEST INDIANA. THE LATEST NAM AND HRW-
WRF RUNS APPEAR TO HAVE THE BEST HANDLE ON THIS FEATURE. FOLLOWING
THIS GUIDANCE...THE BEST POTENTIAL FOR SHOWERS AND THUNDERSTORMS
TODAY APPEARS TO BE OVER THE EASTERN HALF OF THE AREA...ESPECIALLY
SOUTHEAST ILLINOIS...SOUTHWEST INDIANA...AND THE PENNYRILE REGION
OF WESTERN KENTUCKY...AS THE MCV SLOWLY WORKS ITS WAY EAST ACROSS
THE AREA. WILL MAINTAIN THE POTENTIAL FOR ISOLATED MAINLY
DIURNALLY DRIVEN STORMS ELSEWHERE.
MOST MODELS ARE IN AGREEMENT THAT THE CHANCE FOR THUNDERSTORMS
SHOULD DROP OFF CONSIDERABLY TONIGHT THROUGH TUESDAY NIGHT WITH
NO SUBSTANTIAL FOCUSING MECHANISM. BETTER CHANCES FOR ISOLATED
ACTIVITY SHOULD BE CONFINED TO EASTERN AREAS AGAIN ON TUESDAY. IT
WILL REMAIN VERY WARM AND HUMID THROUGH THE NEAR TERM...WITH LOWS
IN THE LOWER 70S AND HIGHS IN THE LOWER 90S.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 354 AM CDT MON JUN 24 2013
THE MODELS CONTINUE TO ADVERTISE WHAT HAS BEEN FORECAST FOR A FEW
DAYS NOW. A SIGNIFICANT MID LEVEL HIGH CENTER OVER THE INTERMOUNTAIN
WEST WILL BECOME ESTABLISHED...WHILE A TROF OVER THE NE/ERN U.S.
MORPHS INTO A CLOSED LOW FEATURE AROUND THE GREAT LAKES REGION BY
THE WEEKEND ENHANCING THE TROF ALL THE WAY TO THE GULF COAST. THIS
WILL PLACE US IN AN UNSETTLED NW FLOW REGIME ALOFT WITH A SOMEWHAT
ILL DEFINED SURFACE PRESSURE PATTERN...THAT SHOULD CONTAIN MORE THAN
ONE SUBTLE WIND SHIFT UNTIL FRIDAY NIGHT WHEN THE FINAL ONE SHOULD
MOVE THROUGH ONCE THE TROF DEEPENS ENOUGH. PRECIP CHANCES NOT REAL
CLEAR CUT IN THIS FLOW PATTERN. HARD TO RULE OUT GIVEN THE TIME OF
YEAR AND UNSETTLED NATURE TO THE FLOW. GIVEN TIMING ISSUES AND MODEL
VARIANCE WHICH IS YIELDING LOW CONFIDENCE...WILL KEEP POPS IN CHECK
AND LOW FOR NOW. THERE IS STILL SOME PERSISTENCE WITH RESPECT TO
LATE WEDNESDAY INTO WEDNESDAY NIGHT...IN THAT THERE MAY BE A
CONVECTIVE SYSTEM THAT WILL AFFECT THE AREA. TEMPS ARE A BLEND OF
ECMWF LONG RANGE MOS / GFS MOS AND HPC GUIDANCE.
&&
.AVIATION...
ISSUED AT 643 AM CDT MON JUN 24 2013
A MESOSCALE VORTEX WILL CONTINUE TO TOUCH OFF SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS AT KEVV AND KOWB THROUGH MID MORNING...WITH
DRY CONDITIONS ELSEWHERE. ISOLATED TO WIDELY SCATTERED THUNDERSTORMS
MAY DEVELOP IN THE HEAT OF THE DAY JUST ABOUT ANYWHERE...BUT LOW
CONFIDENCE PRECLUDES MENTION IN TAFS AT THIS POINT. VFR CONDITIONS
WILL OTHERWISE PREVAIL. EXPECT SOUTHERLY WINDS AOB 10 KNOTS.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
MESOSCALE...SMITH
SHORT TERM...RJP
LONG TERM...CN
AVIATION...RJP
AREA FORECAST DISCUSSION
NWS CARIBOU ME
123 PM EDT MON JUN 24 2013
.SYNOPSIS...
UNSETTLED CONDITIONS WITH SCATTERED SHOWERS AND THUNDERSTORMS WILL
PERSIST THROUGH MID WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
1PM UPDATE...
ADDED ENHANCED WORDING FOR THUNDERSTORMS THIS EVENING IN NORTHERN
ZONES. STRONG THUNDERSTORMS IN QUEBEC WILL ADVECT TOWARDS THE
NORTHWESTERN PORTION OF THE STATE THIS EVENING. THE STORMS WILL
WEAKEN AS THEY CROSS THE FORECAST AREA THIS EVENING. BEST CHANCE
FOR THE STRONGER STORMS WILL BE IN NORTHERN SOMERSET...NORTHERN
PISCATAQUIS AND NORTHERN AROOSTOOK COUNTIES. IN A LINE DOES
FORM...WILL HAVE TO CONSIDER ADDING POPS TO SOUTHERN PISCATAQUIS
AND PENOBSCOT COUNTIES FOR THIS EVENING.
10AM UPDATE...
THE DECAYING MCS IS BRINGING SHOWERS TO HANCOCK AND WASHINGTON
COUNTIES AT THIS TIME AND WILL EXIT THE FORECAST AREA IN THE NEXT
FEW HOURS. SKIES WILL CLEAR FROM NW TO SE AS THE CLOUDS ASSOCIATED
WITH THE OLD MCS LEAVE THE STATE. THIS WILL PRODUCE HIGHS IN THE
MID TO UPPER 80S WITH UNCOMFORTABLE HUMIDITY. ADJUSTED HIGHS UP A FEW
DEGREES. DAYTIME HEATING WILL CREATE SOME DESTABILIZATION WITH THE
BEST CHANCES FOR STRONG STORMS IN THE REMOTE AREAS OF NORTHERN
SOMERSET...PISCATAQUIS AND AROOSTOOK COUNTIES THIS EVENING. STRONG
WIND GUSTS WOULD APPEAR TO BE THE BIGGEST THREAT. HOWEVER...WITH A
STRONG LLJ...HIGH PWATS AND WELL OVER 10K FT OF WARM CLOUD...HEAVY
RAIN IS ALSO A CONCERN.
UPDATE 0530L: DECAYING MCS HAS REACHED OUR FAR WRN ZONES ATTM.
THIS A LITTLE FASTER THAN ERLYR EXPECTED SO HAVE ADJUSTED POPS FOR
CURRENT AND EXPECTED TRENDS THRU THE AM HRS. REMAINDER OF THE FCST UNCHANGED...
DECAYING MCS OVR SRN QUEBEC ATTM ABOUT TO ENTER FAR WRN MAINE...
OTHERWISE...PARTLY TO MOSTLY CLOUDY SKIES ACROSS THE FA ATTM W/
SOME FOG ACROSS THE N. NOT MUCH CHANGE IN THE OVERALL PTRN ACROSS
OUR AREA LAST 24 HRS AT LEAST IN THE UPPER LEVELS OF THE ATMOS AS
BRISK WNW FLOW ALOFT PERSISTS W/ OCNL DISTURBANCES EMBEDDED IN
THIS FLOW. IN THE LOWER LEVELS - A VRY WARM AND HUMID SWRLY FLOW
IS NOW IN PLACE ACROSS THE ENTIRE REGION W/ TDS GENERALLY IN THE
LOWER TO MID 60S. THE DECAYING MCS IS SHOWN BY THE SHORTER TERM
MODELS SUCH AS THE RUC TO CONT TO MV ESEWRD AND HOLD TOGETHER ENUF
TO HAVE SOME IMPACT ON OUR WRN ZNS ERLY TDY THEN ACROSS OUR S
CENTRAL ZNS THRU THE AM HRS AND POPS ACROSS THESE AREAS WILL
REFLECT THIS. OTHERWISE...ANOTHER UPPER DISTURBANCE IS FCST TO
SLIDE ESEWRD ACROSS THE FA LATER TDY AND PROVIDE ANOTHER UPTICK IN
SHOWERS/TSTMS.
UNLIKE SUN...WHERE MOST ACTION WAS S OF THE AREA - APPEARS TDY
THAT THINGS HAVE SHIFTED A LITTLE FURTHER N W/ THE INTRUSION OF
THE WARMER AND MORE HUMID AIR. AS A RESULT...WILL CARRY MAINLY CHC
POPS ACROSS THE REMAINDER OF THE FA TDY INTO THIS EVE W/ ACTIVITY
EXPECTED TO AGAIN WEAKEN/DISSIPATE LATER THIS EVE AS THIS UPPER
DISTURBANCE MVS AWAY FROM THE REGION. THIS WILL SET THE STAGE FOR
MORE PATCHY FOG W/ THE FOG PROBABLY A LITTLE MORE WDSPRD THAN THIS
AM W/ THE HUMID AIRMASS PERSISTING. TEMPS TDY WILL BE A LITTLE
TRICKY... CLDS AND SHOWERS WILL NO DOUBT HAVE SOME IMPACT AND
PROBABLY KEEP MOST AREAS FROM REACHING FULL POTENTIAL TDY.
STILL...A LITTLE SUNSHINE FROM TIME TO TIME IS EXPECTED AND WILL
GO A LONG WAY IN HEATING THINGS UP SO WILL HANG ONTO HIGHS INTO
THE LOWER 80S N W/ MID TO PSBLY UPPER 80S CENTRAL AND INTERIOR
DOWN EAST...
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
PERIOD WILL BEGIN WITH A SURFACE HIGH SETUP IN THE ATLANTIC AND
BOUNDARY DRAPED JUST TO THE NORTH OF THE REGION. THE SURFACE HIGH
WILL CONTINUE TO PUMP WARM AND MOIST AIR INTO THE REGION. GUIDANCE
IS IN FAIR AGREEMENT WITH THE BOUNDARY AND SURFACE LOW BEGINNING
TO DROP SOUTH THROUGH THE DAY ON TUESDAY. THIS COMBINED WITH
BETTER UPPER LEVEL DYNAMICS WITH THE REGION LOCATED IN THE
FAVORABLE RIGHT ENTRANCE REGION OF UPPER LEVEL JET ENHANCING
DIVERGENCE ALOFT. ALSO WITH WARM AND MOIST UNSTABLE AIR IN PLACE
CAPE VALUES WILL BE GENERALLY BETWEEN 500 TO 1500 J/KG. THESE
DYNAMICS WILL MAKE IT POSSIBLE TO HAVE SOME MORE ENHANCED
THUNDERSTORM ACTIVITY TUESDAY AFTERNOON AND EVENING. RIGHT NOW
THINKING IS THERE WILL BE THE POTENTIAL FOR SMALL HAIL AND GUSTY
WINDS BUT THIS MAY NEED TO BE ENHANCED FURTHER IF DYNAMICS
CONTINUE TO COME TOGETHER. BEST CHANCES STILL LOOK TO BE ACROSS
THE NORTHERN AND CENTRAL PORTIONS OF THE REGION WHERE BEST
SUPPORTING DYNAMICS ARE PRESENT.
THERE IS SOME MODEL DIVERGENCE FOR WEDNESDAY WITH THE MOST OF
GUIDANCE WANTING TO KEEP THE LOW PRESSURE ACROSS THE REGION WHILE
THE 23/12Z ECMWF WANTS TO KEEP IT DRIER. RIGHT NOW WILL KEEP
DECENT CONSISTENCY WITH PREVIOUS FORECAST WITH MORE SHOWERY TYPE
ACTIVITY. TEMPERATURES FOR WEDNESDAY LOOK TO BE COOLER ALTHOUGH
THIS WILL BE HIGHLY DEPENDENT ON CLOUD COVER.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE GUIDANCE IS STILL A BIT DIVERGENT IN THE BEGINNING OF THE LONG
TERM PERIOD. THE 24/00Z GFS/GEM WANTS TO HOLD ON TO THE BOUNDARY
AND SURFACE LOW A BIT LONGER THAN THE 23/12Z ECMWF FOR WEDNESDAY
NIGHT. THEN WE WILL SEE ANOTHER STRONG UPPER LEVEL DISTURBANCE
ACROSS THE GREAT LAKES CONTINUE TO PROGRESS EAST. ALL THE LONG
RANGE GUIDANCE INDICATES THIS MOVING EAST BUT WITH SLIGHT DIFFERENCES
IN TIMING. GENERALLY IT LOOKS LIKE THIS SYSTEM WILL BEGIN
PROGRESSING INTO THE REGION THURSDAY AFTERNOON. RIGHT NOW THE
GUIDANCE ALSO WANTS INDICATE THIS UPPER LEVEL LOW BECOMING QUASI-
STATIONARY GENERALLY ACROSS THE GREAT LAKES AND OHIO VALLEY. THIS
WOULD KEEP THE REGION IN A ACTIVE PATTERN THROUGH MUCH OF THE LONG
TERM PERIOD. THIS QUASI-STATIONARY TROUGH SETUP IS ALSO GENERALLY
SUPPORTED BY THE 23/12Z GFS/ECMWF RESPECTIVE ENSEMBLE MEAN. HIGH
AND LOW TEMPERATURES FOR THE PERIOD WILL GENERALLY BE NEAR NORMAL.
&&
.AVIATION /17Z MONDAY THROUGH FRIDAY/...
NEAR TERM: VRBL CONDS ACROSS THE AREA THIS AM W/ SOME IFR IN FOG
ACROSS THE N TO VFR CONDS ACROSS THE S. EXPECT FOG TO DISSIPATE
ERLY THIS AM W/ PREDOM VFR CONDS TDY EXPECT OCNL MVFR TO BRIEF IFR
PSBL IN ANY SHOWERS/TSTMS. FOG WILL AGAIN BE A THREAT TNGT ALONG
W/ A CONTD CHC OF SHOWERS AND PSBL THUNDER...
SHORT TERM: MOST SITES LOOK TO STAY VFR THROUGH THE PERIOD WITH
THE EXCEPTION OF THOSE SITES THAT RECEIVE SHOWER AND THUNDERSTORM
ACTIVITY. THIS WILL BE MORE LIKELY FOR THE NORTHERN SITES.
&&
.MARINE...
NEAR TERM: WINDS/SEAS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS THRU TONIGHT. VISIBILITIES COULD BE REDUCED IN PATCHY
FOG TODAY AND IN MORE WDSPRD AREAS OF FOG TNGT.
SHORT TERM: MARINE: NO HEADLINES EXPECTED AT THIS TIME WITH SEAS
GENERALLY STAYING 2 TO 4 FT AND WINDS 10 TO 15 KT. VISIBILITIES
COULD BE REDUCED WITH SHOWERS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...KHW/MCW
SHORT TERM...JORDAN
LONG TERM...JORDAN
AVIATION...KHW/MCW/JORDAN
MARINE...KHW/MCW/JORDAN
AREA FORECAST DISCUSSION
NWS GRAY ME
1205 PM EDT MON JUN 24 2013
.SYNOPSIS...
WARM AND MOIST AIR CONTINUES TO POOL ALONG AND SOUTH OF A
STATIONARY FRONT SITUATED TO OUR NORTH. SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED EACH DAY THROUGH THE WEEK AS SEVERAL
DISTURBANCES CROSS THE REGION. A LARGE UPPER LEVEL TROUGH WILL
APPROACH FROM THE WEST LATE IN THE WEEK. THIS WILL ALLOW FOR
COOLER TEMPERATURES...BUT INCREASE THE CHANCE FOR SHOWERS ACROSS
THE REGION.
&&
.NEAR TERM /TODAY/...
NOON UPDATE...
HAVE MADE CHANGES TO THE POP STRUCTURE THROUGH THE AFTERNOON.
CUMULUS FIELD NOTED ON VISIBLE SATELLITE BUT NOTHING THAT IS READY
TO DEVELOP DEEP CONVECTION. SOME CONVECTION DEVELOPING OVER THE
ADIRONDACKS IN NEW YORK STATE WILL MOVE EAST THROUGH THE AFTERNOON.
ADDITIONAL DEVELOPMENT IS MOST LIKELY OVER THE HIGHER TERRAIN OF
NEW HAMPSHIRE AND NORTHWEST MAINE BUT COULD ALSO OCCUR ON THE
COASTAL PLAIN LATER IN THE AFTERNOON ONCE TEMPERATURES REACH THEIR
PEAK AND THE CAP BECOMES SUFFICIENTLY OVERCOME.
845 AM UPDATE...
HAVE UPDATED MOST OF THE GRIDDED FORECAST DATABASE THIS MORNING TO
BETTER REFLECT CURRENT FORECAST THINKING. LEFT POP STRUCTURE IN
PLACE FOR THIS AFTERNOON AS THERE WILL BE PLENTY OF CAPE AVAILABLE
WITH THE HEATING AND HUMIDITY THIS AFTERNOON. HOWEVER... UNSURE
THAT THERE WILL BE ENOUGH OF A FOCUSING MECHANISM TO HELP US
OVERCOME THE CAP. SEEMS LIKE THE BEST CHANCE WOULD BE TO GET SOME
STORMS GOING OVER THE MOUNTAINS. IF THIS DOES OCCUR... IT APPEARS
THAT HAIL AND WINDS WILL BE THE PRIMARY THREAT. WITH NEW DEW POINT
FORECAST... SOME AREAS OF SOUTHWEST MAINE SEE HEAT INDEX VALUES
REACH THE UPPER 90S TO NEAR 100 THIS AFTERNOON BUT NOT WIDESPREAD
ENOUGH FOR A HEAT ADVISORY.
630AM UPDATE...
UPDATE EARLY THIS MORNING TO LOWER THE CHANCES OF PRECIPITATION
OVER MUCH OF THE REGION THIS MORNING. THE EXCEPTION CONTINUES TO
BE THE NORTH AND MOUNTAINS WHERE OLD MCS CONTINUES TO DETERIORATE
AND MOVE EAST ACROSS MAINE. LATEST HRRR MODEL IS PICKING UP ON
THIS SYSTEM WELL THIS MORNING.
TIMING OF CONVECTIVE INITIATION TODAY APPEARS TO BE AROUND 16Z-
18Z OVER VERMONT. CELLS WILL ENTER NEW HAMPSHIRE BY AROUND 19Z OR 20Z
AND SPREAD QUICKLY TO THE EAST.
OTHERWISE...HAVE MADE SOME MINOR ADJUSTMENTS TO THE CLOUD...DEW
POINT AND MAX TEMPERATURE GRIDS BASED ON CURRENT TRENDS AND
OBSERVATIONS.
PREVIOUS DISCUSSION...
THE REMAINS OF AN MCS WILL CROSS NORTHERN SECTIONS EARLY THIS
MORNING...AS IT CONTINUES TO WEAKEN AS IT MOVES EAST. A DEVELOPING
WESTERLY FLOW ALOFT WILL ALLOW 850 MB TEMPERATURES TO CLIMB TO AT
OR ABOVE +16C DURING THE AFTERNOON HOURS. WITH AMPLE MIXING...WE
SHOULD EXPECT SOME LOWER 90S OVER SOUTHERN/CENTRAL NEW HAMPSHIRE
AND ADJACENT SECTIONS OF WESTERN MAINE. THERE WILL BE A SURFACE
TROUGH SITUATED NEAR AND ALONG THE COASTLINE...SO ONSHORE WINDS
WILL LIKELY KEEP THINGS COOLER OVER THE MIDCOAST REGION.
CAPES SOAR THIS AFTERNOON INTO THE 1500 J/KG RANGE OVER SOUTHERN
MAINE AND POSSIBLY SOUTHERN NEW HAMPSHIRE DURING THE AFTERNOON
HOURS TODAY AS A SHORT WAVE APPROACHES FROM THE WEST. LI VALUES
DROP SIGNIFICANTLY AS WELL. WE ARE NOT OUTLOOKED BY SPC
TODAY...HOWEVER FEEL COMPELLED TO AT LEAST MENTIONED GUSTY WINDS
AND SMALL HAIL IN THIS AREA.
PRECIPITABLE WATER VALUES WILL BE VERY HIGH TODAY...CLOSE TO 1.75
INCHES. WESTERLY FLOW SHOULD ALLOW FOR QUICK PROGRESSION OF
STORMS. NEVERTHELESS...ANY TRAINING ECHOES WILL NEED TO BE
MONITORED CLOSELY FOR THE THREAT OF HEAVY RAINFALL.
USED A BLEND OF MAV/MET MOS FOR DAYTIME MAX TEMPERATURES...WHICH
PLACES MANY AREAS IN THE LOWER 90S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
PATCHY FOG WILL REDEVELOP TONIGHT...ESPECIALLY IN THE VALLEY
LOCATIONS. THEREAFTER...SHOWERS AND THUNDERSTORMS WILL DEVELOP
DURING THE EARLY AFTERNOON HOURS ON TUESDAY AS VORT MAX APPROACHES
FROM THE NORTH. EXPECT SEVERAL STORMS TO PRODUCE DAMAGING WIND
GUSTS AS THE PRIMARY THREAT FOR SEVERE WEATHER AS THE WIND MAX
CROSSES THE REGION...BUT WE CANNOT RULE OUT THE POSSIBILITY OF
LARGE HAIL AS WELL. WILL HIGHLIGHT THIS IN THE HWO.
EXPECT MANY COMMUNITIES TO TOP OUT AT OR ABOVE 90 DEGREES ONCE
AGAIN OVER SOUTHERN/CENTRAL NEW HAMPSHIRE AND WESTERN MAINE.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THRU THE OUTLOOK PERIOD THE EVOLUTION OF A LONG WAVE TROUGH WILL
BECOME ESTABLISHED OVER THE EASTERN GREAT LAKES AND EXTEND SOUTH
INTO THE OHIO VALLEY. THIS LONG WAVE TROUGH WILL BECOME THE MAIN
WEATHER PRODUCER FOR THE FORECAST PERIOD OF WEDNESDAY THROUGH
SUNDAY. THE DEVELOPING EASTERN LONG WAVE TROUGH WILL MEAN A
CONTINUED MOIST AND UNSTABLE SSW FLOW AT THE SURFACE AND ALOFT
THRU THE WEEK. SHOWERS/THUNDERSTORMS ARE EXPECTED THROUGHOUT THE
WEEK AND INTO THE WEEKEND. TEMPERATURES WILL BE COOLER THROUGH THE
WEEK DUE TO PLENTY OF CLOUDS AND THE MOIST SOUTHERLY FLOW. HIGH
TEMPERATURES WILL BE MOSTLY IN THE 70S BUT DEW POINTS WILL REMAIN
HIGH SO IT WILL BE MUGGY AS WELL.
USED A BLEND OF THE MAV/MET GUIDANCE FOR 4TH/5TH PERIODS AND THEN
THE ADJUSTED MEX TEMPERATURES FOR DAYS 4-7.
&&
.AVIATION /16Z MONDAY THROUGH FRIDAY/...
SHORT TERM...WEST WINDS TODAY MAY GUST INTO THE LOWER 20S. WINDS
AND THE POTENTIAL FOR HAIL IS POSSIBLE OVER SOUTHERN AREAS OF
MAINE THIS AFTERNOON AND OVER ALL AREAS ON TUESDAY.
LONG TERM...
VARIABLE CONDITIONS EXPECTED THRU THE OUTLOOK PERIOD. VFR
CONDITIONS ARE EXPECTED AT TIMES BUT WILL LOWER TO MVFR TO IFR
IN SCATTERED SHOWERS/THUNDERSTORMS THROUGHOUT THE MIDDLE TO END OF
THE WEEK.
&&
.MARINE...
SHORT TERM...
WINDS MAY BECOME GUSTY OVER THE OUTER WATERS TODAY...BUT MOST
LIKELY REMAINING BELOW SCA CRITERIA. SIMILAR CONDITIONS WILL
FOLLOW ON TUESDAY.
LONG TERM...
WINDS/SEAS WILL REMAIN BELOW SCA CONDITIONS THRU THURSDAY BUT MAY
INCREASE TO SCA CRITERIA ON FRIDAY DUE TO AN INCREASING SOUTHERLY
PRESSURE GRADIENT ALLOWING WINDS AND SEAS TO INCREASE.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
NEAR TERM UPDATE...KIMBLE
SHORT TERM...CANNON
LONG TERM...MARINE
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1021 AM EDT MON JUN 24 2013
.SYNOPSIS...
UNSETTLED CONDITIONS WITH SCATTERED SHOWERS AND THUNDERSTORMS WILL
PERSIST THROUGH MID WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
10AM UPDATE...
THE DECAYING MCS IS BRINGING SHOWERS TO HANCOCK AND WASHINGTON
COUNTIES AT THIS TIME AND WILL EXIT THE FORECAST AREA IN THE NEXT
FEW HOURS. SKIES WILL CLEAR FROM NW TO SE AS THE CLOUDS ASSOCIATED
WITH THE OLD MCS LEAVE THE STATE. THIS WILL PRODUCE HIGHS IN THE
MID TO UPPER 80S WITH UNCOMFORTABLE HUMIDITY. ADJUSTED HIGHS UP A FEW
DEGREES. DAYTIME HEATING WILL CREATE SOME DESTABILIZATION WITH THE
BEST CHANCES FOR STRONG STORMS IN THE REMOTE AREAS OF NORTHERN
SOMERSET...PISCATAQUIS AND AROOSTOOK COUNTIES THIS EVENING. STRONG
WIND GUSTS WOULD APPEAR TO BE THE BIGGEST THREAT. HOWEVER...WITH A
STRONG LLJ...HIGH PWATS AND WELL OVER 10K FT OF WARM CLOUD...HEAVY
RAIN IS ALSO A CONCERN.
UPDATE 0530L: DECAYING MCS HAS REACHED OUR FAR WRN ZONES ATTM.
THIS A LITTLE FASTER THAN ERLYR EXPECTED SO HAVE ADJUSTED POPS FOR
CURRENT AND EXPECTED TRENDS THRU THE AM HRS. REMAINDER OF THE FCST UNCHANGED...
DECAYING MCS OVR SRN QUEBEC ATTM ABOUT TO ENTER FAR WRN MAINE...
OTHERWISE...PARTLY TO MOSTLY CLOUDY SKIES ACROSS THE FA ATTM W/
SOME FOG ACROSS THE N. NOT MUCH CHANGE IN THE OVERALL PTRN ACROSS
OUR AREA LAST 24 HRS AT LEAST IN THE UPPER LEVELS OF THE ATMOS AS
BRISK WNW FLOW ALOFT PERSISTS W/ OCNL DISTURBANCES EMBEDDED IN
THIS FLOW. IN THE LOWER LEVELS - A VRY WARM AND HUMID SWRLY FLOW
IS NOW IN PLACE ACROSS THE ENTIRE REGION W/ TDS GENERALLY IN THE
LOWER TO MID 60S. THE DECAYING MCS IS SHOWN BY THE SHORTER TERM
MODELS SUCH AS THE RUC TO CONT TO MV ESEWRD AND HOLD TOGETHER ENUF
TO HAVE SOME IMPACT ON OUR WRN ZNS ERLY TDY THEN ACROSS OUR S
CENTRAL ZNS THRU THE AM HRS AND POPS ACROSS THESE AREAS WILL
REFLECT THIS. OTHERWISE...ANOTHER UPPER DISTURBANCE IS FCST TO
SLIDE ESEWRD ACROSS THE FA LATER TDY AND PROVIDE ANOTHER UPTICK IN
SHOWERS/TSTMS.
UNLIKE SUN...WHERE MOST ACTION WAS S OF THE AREA - APPEARS TDY
THAT THINGS HAVE SHIFTED A LITTLE FURTHER N W/ THE INTRUSION OF
THE WARMER AND MORE HUMID AIR. AS A RESULT...WILL CARRY MAINLY CHC
POPS ACROSS THE REMAINDER OF THE FA TDY INTO THIS EVE W/ ACTIVITY
EXPECTED TO AGAIN WEAKEN/DISSIPATE LATER THIS EVE AS THIS UPPER
DISTURBANCE MVS AWAY FROM THE REGION. THIS WILL SET THE STAGE FOR
MORE PATCHY FOG W/ THE FOG PROBABLY A LITTLE MORE WDSPRD THAN THIS
AM W/ THE HUMID AIRMASS PERSISTING. TEMPS TDY WILL BE A LITTLE
TRICKY... CLDS AND SHOWERS WILL NO DOUBT HAVE SOME IMPACT AND
PROBABLY KEEP MOST AREAS FROM REACHING FULL POTENTIAL TDY.
STILL...A LITTLE SUNSHINE FROM TIME TO TIME IS EXPECTED AND WILL
GO A LONG WAY IN HEATING THINGS UP SO WILL HANG ONTO HIGHS INTO
THE LOWER 80S N W/ MID TO PSBLY UPPER 80S CENTRAL AND INTERIOR
DOWNEAST...
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
PERIOD WILL BEGIN WITH A SURFACE HIGH SETUP IN THE ATLANTIC AND
BOUNDARY DRAPED JUST TO THE NORTH OF THE REGION. THE SURFACE HIGH
WILL CONTINUE TO PUMP WARM AND MOIST AIR INTO THE REGION. GUIDANCE
IS IN FAIR AGREEMENT WITH THE BOUNDARY AND SURFACE LOW BEGINNING
TO DROP SOUTH THROUGH THE DAY ON TUESDAY. THIS COMBINED WITH
BETTER UPPER LEVEL DYNAMICS WITH THE REGION LOCATED IN THE
FAVORABLE RIGHT ENTRANCE REGION OF UPPER LEVEL JET ENHANCING
DIVERGENCE ALOFT. ALSO WITH WARM AND MOIST UNSTABLE AIR IN PLACE
CAPE VALUES WILL BE GENERALLY BETWEEN 500 TO 1500 J/KG. THESE
DYNAMICS WILL MAKE IT POSSIBLE TO HAVE SOME MORE ENHANCED
THUNDERSTORM ACTIVITY TUESDAY AFTERNOON AND EVENING. RIGHT NOW
THINKING IS THERE WILL BE THE POTENTIAL FOR SMALL HAIL AND GUSTY
WINDS BUT THIS MAY NEED TO BE ENHANCED FURTHER IF DYNAMICS
CONTINUE TO COME TOGETHER. BEST CHANCES STILL LOOK TO BE ACROSS
THE NORTHERN AND CENTRAL PORTIONS OF THE REGION WHERE BEST
SUPPORTING DYNAMICS ARE PRESENT.
THERE IS SOME MODEL DIVERGENCE FOR WEDNESDAY WITH THE MOST OF
GUIDANCE WANTING TO KEEP THE LOW PRESSURE ACROSS THE REGION WHILE
THE 23/12Z ECMWF WANTS TO KEEP IT DRIER. RIGHT NOW WILL KEEP
DECENT CONSISTENCY WITH PREVIOUS FORECAST WITH MORE SHOWERY TYPE
ACTIVITY. TEMPERATURES FOR WEDNESDAY LOOK TO BE COOLER ALTHOUGH
THIS WILL BE HIGHLY DEPENDENT ON CLOUD COVER.&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE GUIDANCE IS STILL A BIT DIVERGENT IN THE BEGINNING OF THE LONG
TERM PERIOD. THE 24/00Z GFS/GEM WANTS TO HOLD ON TO THE BOUNDARY
AND SURFACE LOW A BIT LONGER THAN THE 23/12Z ECMWF FOR WEDNESDAY
NIGHT. THEN WE WILL SEE ANOTHER STRONG UPPER LEVEL DISTURBANCE
ACROSS THE GREAT LAKES CONTINUE TO PROGRESS EAST. ALL THE LONG
RANGE GUIDANCE INDICATES THIS MOVING EAST BUT WITH SLIGHT DIFFERENCES
IN TIMING. GENERALLY IT LOOKS LIKE THIS SYSTEM WILL BEGIN
PROGRESSING INTO THE REGION THURSDAY AFTERNOON. RIGHT NOW THE
GUIDANCE ALSO WANTS INDICATE THIS UPPER LEVEL LOW BECOMING QUASI-
STATIONARY GENERALLY ACROSS THE GREAT LAKES AND OHIO VALLEY. THIS
WOULD KEEP THE REGION IN A ACTIVE PATTERN THROUGH MUCH OF THE LONG
TERM PERIOD. THIS QUASI-STATIONARY TROUGH SETUP IS ALSO GENERALLY
SUPPORTED BY THE 23/12Z GFS/ECMWF RESPECTIVE ENSEMBLE MEAN. HIGH
AND LOW TEMPERATURES FOR THE PERIOD WILL GENERALLY BE NEAR NORMAL.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
NEAR TERM: VRBL CONDS ACROSS THE AREA THIS AM W/ SOME IFR IN FOG
ACROSS THE N TO VFR CONDS ACROSS THE S. EXPECT FOG TO DISSIPATE
ERLY THIS AM W/ PREDOM VFR CONDS TDY EXPECT OCNL MVFR TO BRIEF IFR
PSBL IN ANY SHOWERS/TSTMS. FOG WILL AGAIN BE A THREAT TNGT ALONG
W/ A CONTD CHC OF SHOWERS AND PSBL THUNDER...
SHORT TERM: MOST SITES LOOK TO STAY VFR THROUGH THE PERIOD WITH
THE EXCEPTION OF THOSE SITES THAT RECEIVE SHOWER AND THUNDERSTORM
ACTIVITY. THIS WILL BE MORE LIKELY FOR THE NORTHERN SITES.
&&
.MARINE...
NEAR TERM: WINDS/SEAS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS THRU TONIGHT. VISIBILITIES COULD BE REDUCED IN PATCHY
FOG TODAY AND IN MORE WDSPRD AREAS OF FOG TNGT.
SHORT TERM: MARINE: NO HEADLINES EXPECTED AT THIS TIME WITH SEAS
GENERALLY STAYING 2 TO 4 FT AND WINDS 10 TO 15 KT. VISIBILITIES
COULD BE REDUCED WITH SHOWERS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...KHW/MCW
SHORT TERM...JORDAN
LONG TERM...JORDAN
AVIATION...KHW/MCW/JORDAN
MARINE...KHW/MCW/JORDAN
AREA FORECAST DISCUSSION
NWS GRAY ME
852 AM EDT MON JUN 24 2013
.SYNOPSIS...
WARM AND MOIST AIR CONTINUES TO POOL ALONG AND SOUTH OF A
STATIONARY FRONT SITUATED TO OUR NORTH. SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED EACH DAY THROUGH THE WEEK AS SEVERAL
DISTURBANCES CROSS THE REGION. A LARGE UPPER LEVEL TROUGH WILL
APPROACH FROM THE WEST LATE IN THE WEEK. THIS WILL ALLOW FOR
COOLER TEMPERATURES...BUT INCREASE THE CHANCE FOR SHOWERS ACROSS
THE REGION.
&&
.NEAR TERM /TODAY/...
845 AM UPDATE...
HAVE UPDATED MOST OF THE GRIDDED FORECAST DATABASE THIS MORNING TO
BETTER REFLECT CURRENT FORECAST THINKING. LEFT POP STRUCTURE IN
PLACE FOR THIS AFTERNOON AS THERE WILL BE PLENTY OF CAPE AVAILABLE
WITH THE HEATING AND HUMIDITY THIS AFTERNOON. HOWEVER... UNSURE
THAT THERE WILL BE ENOUGH OF A FOCUSING MECHANISM TO HELP US
OVERCOME THE CAP. SEEMS LIKE THE BEST CHANCE WOULD BE TO GET SOME
STORMS GOING OVER THE MOUNTAINS. IF THIS DOES OCCUR... IT APPEARS
THAT HAIL AND WINDS WILL BE THE PRIMARY THREAT. WITH NEW DEW POINT
FORECAST... SOME AREAS OF SOUTHWEST MAINE SEE HEAT INDEX VALUES
REACH THE UPPER 90S TO NEAR 100 THIS AFTERNOON BUT NOT WIDESPREAD
ENOUGH FOR A HEAT ADVISORY.
630AM UPDATE...
UPDATE EARLY THIS MORNING TO LOWER THE CHANCES OF PRECIPITATION
OVER MUCH OF THE REGION THIS MORNING. THE EXCEPTION CONTINUES TO
BE THE NORTH AND MOUNTAINS WHERE OLD MCS CONTINUES TO DETERIORATE
AND MOVE EAST ACROSS MAINE. LATEST HRRR MODEL IS PICKING UP ON
THIS SYSTEM WELL THIS MORNING.
TIMING OF CONVECTIVE INITIATION TODAY APPEARS TO BE AROUND 16Z-
18Z OVER VERMONT. CELLS WILL ENTER NEW HAMPSHIRE BY AROUND 19Z OR 20Z
AND SPREAD QUICKLY TO THE EAST.
OTHERWISE...HAVE MADE SOME MINOR ADJUSTMENTS TO THE CLOUD...DEW
POINT AND MAX TEMPERATURE GRIDS BASED ON CURRENT TRENDS AND
OBSERVATIONS.
PREVIOUS DISCUSSION...
THE REMAINS OF AN MCS WILL CROSS NORTHERN SECTIONS EARLY THIS
MORNING...AS IT CONTINUES TO WEAKEN AS IT MOVES EAST. A DEVELOPING
WESTERLY FLOW ALOFT WILL ALLOW 850 MB TEMPERATURES TO CLIMB TO AT
OR ABOVE +16C DURING THE AFTERNOON HOURS. WITH AMPLE MIXING...WE
SHOULD EXPECT SOME LOWER 90S OVER SOUTHERN/CENTRAL NEW HAMPSHIRE
AND ADJACENT SECTIONS OF WESTERN MAINE. THERE WILL BE A SURFACE
TROUGH SITUATED NEAR AND ALONG THE COASTLINE...SO ONSHORE WINDS
WILL LIKELY KEEP THINGS COOLER OVER THE MIDCOAST REGION.
CAPES SOAR THIS AFTERNOON INTO THE 1500 J/KG RANGE OVER SOUTHERN
MAINE AND POSSIBLY SOUTHERN NEW HAMPSHIRE DURING THE AFTERNOON
HOURS TODAY AS A SHORT WAVE APPROACHES FROM THE WEST. LI VALUES
DROP SIGNIFICANTLY AS WELL. WE ARE NOT OUTLOOKED BY SPC
TODAY...HOWEVER FEEL COMPELLED TO AT LEAST MENTIONED GUSTY WINDS
AND SMALL HAIL IN THIS AREA.
PRECIPITABLE WATER VALUES WILL BE VERY HIGH TODAY...CLOSE TO 1.75
INCHES. WESTERLY FLOW SHOULD ALLOW FOR QUICK PROGRESSION OF
STORMS. NEVERTHELESS...ANY TRAINING ECHOES WILL NEED TO BE
MONITORED CLOSELY FOR THE THREAT OF HEAVY RAINFALL.
USED A BLEND OF MAV/MET MOS FOR DAYTIME MAX TEMPERATURES...WHICH
PLACES MANY AREAS IN THE LOWER 90S.
&&
.SHORT TERM /TONIGHT AND TUESDAY/...
PATCHY FOG WILL REDEVELOP TONIGHT...ESPECIALLY IN THE VALLEY
LOCATIONS. THEREAFTER...SHOWERS AND THUNDERSTORMS WILL DEVELOP
DURING THE EARLY AFTERNOON HOURS ON TUESDAY AS VORT MAX APPROACHES
FROM THE NORTH. EXPECT SEVERAL STORMS TO PRODUCE DAMAGING WIND
GUSTS AS THE PRIMARY THREAT FOR SEVERE WEATHER AS THE WIND MAX
CROSSES THE REGION...BUT WE CANNOT RULE OUT THE POSSIBILITY OF
LARGE HAIL AS WELL. WILL HIGHLIGHT THIS IN THE HWO.
EXPECT MANY COMMUNITIES TO TOP OUT AT OR ABOVE 90 DEGREES ONCE
AGAIN OVER SOUTHERN/CENTRAL NEW HAMPSHIRE AND WESTERN MAINE.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THRU THE OUTLOOK PERIOD THE EVOLUTION OF A LONG WAVE TROUGH WILL
BECOME ESTABLISHED OVER THE EASTERN GREAT LAKES AND EXTEND SOUTH
INTO THE OHIO VALLEY. THIS LONG WAVE TROUGH WILL BECOME THE MAIN
WEATHER PRODUCER FOR THE FORECAST PERIOD OF WEDNESDAY THROUGH
SUNDAY. THE DEVELOPING EASTERN LONG WAVE TROUGH WILL MEAN A
CONTINUED MOIST AND UNSTABLE SSW FLOW AT THE SURFACE AND ALOFT
THRU THE WEEK. SHOWERS/THUNDERSTORMS ARE EXPECTED THROUGHOUT THE
WEEK AND INTO THE WEEKEND. TEMPERATURES WILL BE COOLER THROUGH THE
WEEK DUE TO PLENTY OF CLOUDS AND THE MOIST SOUTHERLY FLOW. HIGH
TEMPERATURES WILL BE MOSTLY IN THE 70S BUT DEW POINTS WILL REMAIN
HIGH SO IT WILL BE MUGGY AS WELL.
USED A BLEND OF THE MAV/MET GUIDANCE FOR 4TH/5TH PERIODS AND THEN
THE ADJUSTED MEX TEMPERATURES FOR DAYS 4-7.
&&
.AVIATION /13Z MONDAY THROUGH FRIDAY/...
SHORT TERM...WEST WINDS TODAY MAY GUST INTO THE LOWER 20S. WINDS
AND THE POTENTIAL FOR HAIL IS POSSIBLE OVER SOUTHERN AREAS OF
MAINE THIS AFTERNOON AND OVER ALL AREAS ON TUESDAY.
LONG TERM...
VARIABLE CONDITIONS EXPECTED THRU THE OUTLOOK PERIOD. VFR
CONDITIONS ARE EXPECTED AT TIMES BUT WILL LOWER TO MVFR TO IFR
IN SCATTERED SHOWERS/THUNDERSTORMS THROUGHOUT THE MIDDLE TO END OF
THE WEEK.
&&
.MARINE...
SHORT TERM...
WINDS MAY BECOME GUSTY OVER THE OUTER WATERS TODAY...BUT MOST
LIKELY REMAINING BELOW SCA CRITERIA. SIMILAR CONDITIONS WILL
FOLLOW ON TUESDAY.
LONG TERM...
WINDS/SEAS WILL REMAIN BELOW SCA CONDITIONS THRU THURSDAY BUT MAY
INCREASE TO SCA CRITERIA ON FRIDAY DUE TO AN INCREASING SOUTHERLY
PRESSURE GRADIENT ALLOWING WINDS AND SEAS TO INCREASE.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
NEAR TERM UPDATE...KIMBLE
SHORT TERM...CANNON
LONG TERM...MARINE
AREA FORECAST DISCUSSION
NWS GRAY ME
629 AM EDT MON JUN 24 2013
.SYNOPSIS...
WARM AND MOIST AIR CONTINUES TO POOL ALONG AND SOUTH OF A
STATIONARY FRONT SITUATED TO OUR NORTH. SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED EACH DAY THROUGH THE WEEK AS SEVERAL
DISTURBANCES CROSS THE REGION. A LARGE UPPER LEVEL TROUGH WILL
APPROACH FROM THE WEST LATE IN THE WEEK. THIS WILL ALLOW FOR
COOLER TEMPERATURES...BUT INCREASE THE CHANCE FOR SHOWERS ACROSS
THE REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
UPDATE EARLY THIS MORNING TO LOWER THE CHANCES OF PRECIPTATION
OVER MUCH OF THE REGION THIS MORNING. THE EXCEPTION CONTINUES TO
BE THE NORTH AND MOUNTAINS WHERE OLD MCS CONTINUES TO DETEORATE
AND MOVE EAST ACROSS MAINE. LATEST HRRR MODEL IS PICKING UP ON
THIS SYSTEM WELL THIS MORNING.
TIMING OF CONVECTIVE INITIATION TODAY APPEARS TO BE AROUND 16Z-
18Z OVER VERMONT. CELLS WILL ENTER NEW HAMPSHIRE BY AROUND 19Z OR 20Z
AND SPREAD QUICKLY TO THE EAST.
OTHERWISE...HAVE MADE SOME MINOR ADJUSTMENTS TO THE CLOUD...DEW
POINT AND MAX TEMPERATURE GRIDS BASED ON CURRENT TRENDS AND
OBSERVATIONS.
PREV DISC...
THE REMAINS OF AN MCS WILL CROSS NORTHERN SECTIONS EARLY THIS
MORNING...AS IT CONTINUES TO WEAKEN AS IT MOVES EAST. A DEVELOPING
WESTERLY FLOW ALOFT WILL ALLOW 850 MB TEMPERATURES TO CLIMB TO AOA
+16C DURING THE AFTERNOON HOURS. WITH AMPLE MIXING...WE SHOULD
EXPECT SOME LOWER 90S OVER SOUTHERN/CENTRAL NH AND ADJACENT
SECTIONS OF WESTERN MAINE. THERE WILL BE A SURFACE TROUGH SITUATED
NEAR AND ALONG THE COASTLINE...SO ONSHORE WINDS WILL LIKELY KEEP
THINGS COOLER OVER THE MIDCOAST REGION.
CAPES SOAR THIS AFTERNOON INTO THE 1500 J/KG RANGE OVER SOUTHERN
MAINE AND POSSIBLY SOUTHERN NEW HAMPSHIRE DURING THE AFTERNOON
HOURS TODAY AS A SHORT WAVE APPROACHES FROM THE WEST. LIS DROP
SIGNIFICANTLY AS WELL. WE ARE NOT OUTLOOKED BY SPC TODAY...HOWEVER
FEEL COMPELLED TO AT LEAST MENTIONED GUSTY WINDS AND SMALL HAIL IN
THIS AREA.
PRECIPITABLE WATER VALUES WILL BE VERY HIGH TODAY...CLOSE TO 1.75
INCHES. WESTERLY FLOW SHOULD ALLOW FOR QUICK PROGRESSION OF
STORMS. NEVERTHELESS...ANY TRAINING ECHOES WILL NEED TO BE
MONITORED CLOSELY FOR THE THREAT OF HEAVY RAINFALL.
USED A BLEND OF MAV/MET MOS FOR DAYTIME MAX TEMPERATURES...WHICH
PLACES MANY AREAS IN THE LOWER 90S.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
PATCHY FOG WILL REDEVELOP TONIGHT...ESPECIALLY IN THE VALLEY
LOCATIONS. THEREAFTER...SHOWERS AND THUNDERSTORMS WILL DEVELOP
DURING THE EARLY AFTERNOON HOURS ON TUESDAY AS VORT MAX APPROACHES
FROM THE NORTH. EXPECT SEVERAL STORMS TO PRODUCE DAMAGING WIND
GUSTS AS THE PRIMARY THREAT FOR SEVERE WEATHER AS THE WIND MAX
CROSSES THE REGION...BUT WE CAN`T RULE OUT THE POSSIBILITY OF LARGE
HAIL AS WELL. WILL HIGHLIGHT THIS IN THE HWO.
EXPECT MANY COMMUNITIES TO TOP OUT AT OR ABOVE 90 DEGREES ONCE
AGAIN OVER SOUTHER/CENTRAL NEW HAMPSHIRE AND WESTERN MAINE.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THRU THE OUTLOOK PERIOD THE EVOLUTION OF A LONG WAVE TROF WILL
BECOME ESTABLISHED OVER THE ERN GT LAKES AND EXTEND S INTO THE
OHIO VALLEY. THIS L/WV TROF WILL BECOME THE MAIN WX PRODUCER FOR
THE FCST PERIOD OF WED-SUN. THE DEVELOPING EASTERN L/WV TROF WILL
MEAN A CONTINUED MOIST AND UNSTBL SSWLY FLOW AT THE SFC/ALOFT THRU
THE WEEK. SHWRS/TSTMS ARE EXPECTED THROUGHOUT THE WEEK AND INTO
THE WEEKEND. TEMPS WILL BE COOLER THROUGH THE WEEK DUE TO PLENTY
OF CLOUDS AND THE MOIST SLY FLOW. HIGH TEMPS WILL BE MOSTLY IN THE
70S BUT DEWPOINTS WILL REMAIN HIGH SO IT WILL BE MUGGY AS WELL.
USED A BLEND OF THE MAV/MET GUID FOR 4TH/5TH PERIODS AND THEN THE
ADJUSTED MEX TEMPS FOR DAYS 4-7.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
SHORT TERM...
MOISTURE TRAPPED UNDER AN INVERSION WILL KEEP PERIODS OF LIFR AND
VLIFR CEILINGS IN THE TERMINAL FORECASTS EARLY THIS MORNING. WEST
WINDS TODAY MAY GUST INTO THE LOWER 20S. WINDS AND THE POTENTIAL
FOR HAIL IS POSSIBLE OVER SOUTHERN AREAS OF MAINE THIS AFTERNOON
AND OVER ALL AREAS ON TUESDAY.
LONG TERM...
VARIABLE CONDS EXPECTED THRU THE OUTLOOK PERIOD. VFR CONDS ARE
EXPECTED AT TIMES BUT WILL LOWER TO MVFR TO IFR IN SCT SHWRS/TSTMS
THROUGHOUT THE MIDDLE TO END OF THE WEEK.
&&
.MARINE...
SHORT TERM...
WINDS MAY BECOME GUSTY OVER THE OUTER WATERS TODAY...BUT MOST
LIKELY REMAINING BELOW SCA CRITERIA. SIMILAR CONDITIONS WILL
FOLLOW ON TUESDAY.
LONG TERM...
WINDS/SEAS WILL REMAIN BLO SCA CONDS THRU THURSDAY BUT MAY
INCREASE TO SCA CRITERIA ON FRI DUE TO AN INCREASING SLY PRES
GRADIENT ALLOWING WINDS AND SEAS TO INCREASE.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
535 AM EDT MON JUN 24 2013
.SYNOPSIS...
UNSETTLED CONDITIONS WITH SCATTERED SHOWERS AND THUNDERSTORMS WILL
PERSIST THROUGH MID WEEK.&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE 0530L: DECAYING MCS HAS REACHED OUR FAR WRN ZONES ATTM.
THIS A LITTLE FASTER THAN ERLYR EXPECTED SO HAVE ADJUSTED POPS FOR
CURRENT AND EXPECTED TRENDS THRU THE AM HRS. REMAINDER OF THE FCST UNCHANGED...
DECAYING MCS OVR SRN QUEBEC ATTM ABOUT TO ENTER FAR WRN MAINE...
OTHERWISE...PARTLY TO MOSTLY CLOUDY SKIES ACROSS THE FA ATTM W/
SOME FOG ACROSS THE N. NOT MUCH CHANGE IN THE OVERALL PTRN ACROSS
OUR AREA LAST 24 HRS AT LEAST IN THE UPPER LEVELS OF THE ATMOS AS
BRISK WNW FLOW ALOFT PERSISTS W/ OCNL DISTURBANCES EMBEDDED IN
THIS FLOW. IN THE LOWER LEVELS - A VRY WARM AND HUMID SWRLY FLOW
IS NOW IN PLACE ACROSS THE ENTIRE REGION W/ TDS GENERALLY IN THE
LOWER TO MID 60S. THE DECAYING MCS IS SHOWN BY THE SHORTER TERM
MODELS SUCH AS THE RUC TO CONT TO MV ESEWRD AND HOLD TOGETHER ENUF
TO HAVE SOME IMPACT ON OUR WRN ZNS ERLY TDY THEN ACROSS OUR S
CENTRAL ZNS THRU THE AM HRS AND POPS ACROSS THESE AREAS WILL
REFLECT THIS. OTHERWISE...ANOTHER UPPER DISTURBANCE IS FCST TO
SLIDE ESEWRD ACROSS THE FA LATER TDY AND PROVIDE ANOTHER UPTICK IN
SHOWERS/TSTMS.
UNLIKE SUN...WHERE MOST ACTION WAS S OF THE AREA - APPEARS TDY
THAT THINGS HAVE SHIFTED A LITTLE FURTHER N W/ THE INTRUSION OF
THE WARMER AND MORE HUMID AIR. AS A RESULT...WILL CARRY MAINLY CHC
POPS ACROSS THE REMAINDER OF THE FA TDY INTO THIS EVE W/ ACTIVITY
EXPECTED TO AGAIN WEAKEN/DISSIPATE LATER THIS EVE AS THIS UPPER
DISTURBANCE MVS AWAY FROM THE REGION. THIS WILL SET THE STAGE FOR
MORE PATCHY FOG W/ THE FOG PROBABLY A LITTLE MORE WDSPRD THAN THIS
AM W/ THE HUMID AIRMASS PERSISTING. TEMPS TDY WILL BE A LITTLE
TRICKY... CLDS AND SHOWERS WILL NO DOUBT HAVE SOME IMPACT AND
PROBABLY KEEP MOST AREAS FROM REACHING FULL POTENTIAL TDY.
STILL...A LITTLE SUNSHINE FROM TIME TO TIME IS EXPECTED AND WILL
GO A LONG WAY IN HEATING THINGS UP SO WILL HANG ONTO HIGHS INTO
THE LOWER 80S N W/ MID TO PSBLY UPPER 80S CENTRAL AND INTERIOR
DOWNEAST...&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
PERIOD WILL BEGIN WITH A SURFACE HIGH SETUP IN THE ATLANTIC AND
BOUNDARY DRAPED JUST TO THE NORTH OF THE REGION. THE SURFACE HIGH
WILL CONTINUE TO PUMP WARM AND MOIST AIR INTO THE REGION. GUIDANCE
IS IN FAIR AGREEMENT WITH THE BOUNDARY AND SURFACE LOW BEGINNING
TO DROP SOUTH THROUGH THE DAY ON TUESDAY. THIS COMBINED WITH
BETTER UPPER LEVEL DYNAMICS WITH THE REGION LOCATED IN THE
FAVORABLE RIGHT ENTRANCE REGION OF UPPER LEVEL JET ENHANCING
DIVERGENCE ALOFT. ALSO WITH WARM AND MOIST UNSTABLE AIR IN PLACE
CAPE VALUES WILL BE GENERALLY BETWEEN 500 TO 1500 J/KG. THESE
DYNAMICS WILL MAKE IT POSSIBLE TO HAVE SOME MORE ENHANCED
THUNDERSTORM ACTIVITY TUESDAY AFTERNOON AND EVENING. RIGHT NOW
THINKING IS THERE WILL BE THE POTENTIAL FOR SMALL HAIL AND GUSTY
WINDS BUT THIS MAY NEED TO BE ENHANCED FURTHER IF DYNAMICS
CONTINUE TO COME TOGETHER. BEST CHANCES STILL LOOK TO BE ACROSS
THE NORTHERN AND CENTRAL PORTIONS OF THE REGION WHERE BEST
SUPPORTING DYNAMICS ARE PRESENT.
THERE IS SOME MODEL DIVERGENCE FOR WEDNESDAY WITH THE MOST OF
GUIDANCE WANTING TO KEEP THE LOW PRESSURE ACROSS THE REGION WHILE
THE 23/12Z ECMWF WANTS TO KEEP IT DRIER. RIGHT NOW WILL KEEP
DECENT CONSISTENCY WITH PREVIOUS FORECAST WITH MORE SHOWERY TYPE
ACTIVITY. TEMPERATURES FOR WEDNESDAY LOOK TO BE COOLER ALTHOUGH
THIS WILL BE HIGHLY DEPENDENT ON CLOUD COVER.&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE GUIDANCE IS STILL A BIT DIVERGENT IN THE BEGINNING OF THE LONG
TERM PERIOD. THE 24/00Z GFS/GEM WANTS TO HOLD ON TO THE BOUNDARY
AND SURFACE LOW A BIT LONGER THAN THE 23/12Z ECMWF FOR WEDNESDAY
NIGHT. THEN WE WILL SEE ANOTHER STRONG UPPER LEVEL DISTURBANCE
ACROSS THE GREAT LAKES CONTINUE TO PROGRESS EAST. ALL THE LONG
RANGE GUIDANCE INDICATES THIS MOVING EAST BUT WITH SLIGHT DIFFERENCES
IN TIMING. GENERALLY IT LOOKS LIKE THIS SYSTEM WILL BEGIN
PROGRESSING INTO THE REGION THURSDAY AFTERNOON. RIGHT NOW THE
GUIDANCE ALSO WANTS INDICATE THIS UPPER LEVEL LOW BECOMING QUASI-
STATIONARY GENERALLY ACROSS THE GREAT LAKES AND OHIO VALLEY. THIS
WOULD KEEP THE REGION IN A ACTIVE PATTERN THROUGH MUCH OF THE LONG
TERM PERIOD. THIS QUASI-STATIONARY TROUGH SETUP IS ALSO GENERALLY
SUPPORTED BY THE 23/12Z GFS/ECMWF RESPECTIVE ENSEMBLE MEAN. HIGH
AND LOW TEMPERATURES FOR THE PERIOD WILL GENERALLY BE NEAR NORMAL.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
NEAR TERM: VRBL CONDS ACROSS THE AREA THIS AM W/ SOME IFR IN FOG
ACROSS THE N TO VFR CONDS ACROSS THE S. EXPECT FOG TO DISSIPATE
ERLY THIS AM W/ PREDOM VFR CONDS TDY EXPECT OCNL MVFR TO BRIEF IFR
PSBL IN ANY SHOWERS/TSTMS. FOG WILL AGAIN BE A THREAT TNGT ALONG
W/ A CONTD CHC OF SHOWERS AND PSBL THUNDER...
SHORT TERM: MOST SITES LOOK TO STAY VFR THROUGH THE PERIOD WITH
THE EXCEPTION OF THOSE SITES THAT RECEIVE SHOWER AND THUNDERSTORM
ACTIVITY. THIS WILL BE MORE LIKELY FOR THE NORTHERN SITES.
&&
.MARINE...
NEAR TERM: WINDS/SEAS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS THRU TONIGHT. VISIBILITIES COULD BE REDUCED IN PATCHY
FOG TODAY AND IN MORE WDSPRD AREAS OF FOG TNGT.
SHORT TERM: MARINE: NO HEADLINES EXPECTED AT THIS TIME WITH SEAS
GENERALLY STAYING 2 TO 4 FT AND WINDS 10 TO 15 KT. VISIBILITIES
COULD BE REDUCED WITH SHOWERS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...KHW
SHORT TERM...JORDAN
LONG TERM...JORDAN
AVIATION...KHW/JORDAN
MARINE...KHW/JORDAN
AREA FORECAST DISCUSSION
NWS GRAY ME
534 AM EDT MON JUN 24 2013
.SYNOPSIS...
WARM AND MOIST AIR CONTINUES TO POOL ALONG AND SOUTH OF A
STATIONARY FRONT SITUATED TO OUR NORTH. SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED EACH DAY THROUGH THE WEEK AS SEVERAL
DISTURBANCES CROSS THE REGION. A LARGE UPPER LEVEL TROUGH WILL
APPROACH FROM THE WEST LATE IN THE WEEK. THIS WILL ALLOW FOR
COOLER TEMPERATURES...BUT INCREASE THE CHANCE FOR SHOWERS ACROSS
THE REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...
UPDATE EARLY THIS MORNING IF FOR THE CHANCES OF PRECIPTATION BEING
LIMITED THIS MORNING...WITH THE EXCEPTION OF THE NORTH AND
MOUNTAINS WHERE OLD MCS CONTINUES TO DETEORATE AND MOVE EAST
ACROSS MAINE. LATEST HRRR MODEL IS PICKING UP ON THIS SYSTEM WELL
THIS MORNING. CONVECTIVE INITIATION THIS AFTERNOON APPEARS TO BE
AROUND 18Z-19Z OVER VERMONT. CELLS WILL ENTER NEW HAMPSHIRE BY
AROUND 20Z.
PREV DISC...
THE REMAINS OF AN MCS WILL CROSS NORTHERN SECTIONS EARLY THIS
MORNING...AS IT CONTINUES TO WEAKEN AS IT MOVES EAST. A DEVELOPING
WESTERLY FLOW ALOFT WILL ALLOW 850 MB TEMPERATURES TO CLIMB TO AOA
+16C DURING THE AFTERNOON HOURS. WITH AMPLE MIXING...WE SHOULD
EXPECT SOME LOWER 90S OVER SOUTHERN/CENTRAL NH AND ADJACENT
SECTIONS OF WESTERN MAINE. THERE WILL BE A SURFACE TROUGH SITUATED
NEAR AND ALONG THE COASTLINE...SO ONSHORE WINDS WILL LIKELY KEEP
THINGS COOLER OVER THE MIDCOAST REGION.
CAPES SOAR THIS AFTERNOON INTO THE 1500 J/KG RANGE OVER SOUTHERN
MAINE AND POSSIBLY SOUTHERN NEW HAMPSHIRE DURING THE AFTERNOON
HOURS TODAY AS A SHORT WAVE APPROACHES FROM THE WEST. LIS DROP
SIGNIFICANTLY AS WELL. WE ARE NOT OUTLOOKED BY SPC TODAY...HOWEVER
FEEL COMPELLED TO AT LEAST MENTIONED GUSTY WINDS AND SMALL HAIL IN
THIS AREA.
PRECIPITABLE WATER VALUES WILL BE VERY HIGH TODAY...CLOSE TO 1.75
INCHES. WESTERLY FLOW SHOULD ALLOW FOR QUICK PROGRESSION OF
STORMS. NEVERTHELESS...ANY TRAINING ECHOES WILL NEED TO BE
MONITORED CLOSELY FOR THE THREAT OF HEAVY RAINFALL.
USED A BLEND OF MAV/MET MOS FOR DAYTIME MAX TEMPERATURES...WHICH
PLACES MANY AREAS IN THE LOWER 90S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
PATCHY FOG WILL REDEVELOP TONIGHT...ESPECIALLY IN THE VALLEY
LOCATIONS. THEREAFTER...SHOWERS AND THUNDERSTORMS WILL DEVELOP
DURING THE EARLY AFTERNOON HOURS ON TUESDAY AS VORT MAX APPROACHES
FROM THE NORTH. EXPECT SEVERAL STORMS TO PRODUCE DAMAGING WIND
GUSTS AS THE PRIMARY THREAT FOR SEVERE WEATHER AS THE WIND MAX
CROSSES THE REGION...BUT WE CAN`T RULE OUT THE POSSIBILITY OF LARGE
HAIL AS WELL. WILL HIGHLIGHT THIS IN THE HWO.
EXPECT MANY COMMUNITIES TO TOP OUT AT OR ABOVE 90 DEGREES ONCE
AGAIN OVER SOUTHER/CENTRAL NEW HAMPSHIRE AND WESTERN MAINE.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THRU THE OUTLOOK PERIOD THE EVOLUTION OF A LONG WAVE TROF WILL
BECOME ESTABLISHED OVER THE ERN GT LAKES AND EXTEND S INTO THE
OHIO VALLEY. THIS L/WV TROF WILL BECOME THE MAIN WX PRODUCER FOR
THE FCST PERIOD OF WED-SUN. THE DEVELOPING EASTERN L/WV TROF WILL
MEAN A CONTINUED MOIST AND UNSTBL SSWLY FLOW AT THE SFC/ALOFT THRU
THE WEEK. SHWRS/TSTMS ARE EXPECTED THROUGHOUT THE WEEK AND INTO
THE WEEKEND. TEMPS WILL BE COOLER THROUGH THE WEEK DUE TO PLENTY
OF CLOUDS AND THE MOIST SLY FLOW. HIGH TEMPS WILL BE MOSTLY IN THE
70S BUT DEWPOINTS WILL REMAIN HIGH SO IT WILL BE MUGGY AS WELL.
USED A BLEND OF THE MAV/MET GUID FOR 4TH/5TH PERIODS AND THEN THE
ADJUSTED MEX TEMPS FOR DAYS 4-7.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
SHORT TERM...
MOISTURE TRAPPED UNDER AN INVERSION WILL KEEP PERIODS OF LIFR AND
VLIFR CEILINGS IN THE TERMINAL FORECASTS EARLY THIS MORNING. WEST
WINDS TODAY MAY GUST INTO THE LOWER 20S. WINDS AND THE POTENTIAL
FOR HAIL IS POSSIBLE OVER SOUTHERN AREAS OF MAINE THIS AFTERNOON
AND OVER ALL AREAS ON TUESDAY.
LONG TERM...
VARIABLE CONDS EXPECTED THRU THE OUTLOOK PERIOD. VFR CONDS ARE
EXPECTED AT TIMES BUT WILL LOWER TO MVFR TO IFR IN SCT SHWRS/TSTMS
THROUGHOUT THE MIDDLE TO END OF THE WEEK.
&&
.MARINE...
SHORT TERM...
WINDS MAY BECOME GUSTY OVER THE OUTER WATERS TODAY...BUT MOST
LIKELY REMAINING BELOW SCA CRITERIA. SIMILAR CONDITIONS WILL
FOLLOW ON TUESDAY.
LONG TERM...
WINDS/SEAS WILL REMAIN BLO SCA CONDS THRU THURSDAY BUT MAY
INCREASE TO SCA CRITERIA ON FRI DUE TO AN INCREASING SLY PRES
GRADIENT ALLOWING WINDS AND SEAS TO INCREASE.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
407 AM EDT MON JUN 24 2013
.SYNOPSIS...
UNSETTLED CONDITIONS WITH SCATTERED SHOWERS AND THUNDERSTORMS WILL
PERSIST THROUGH MID WEEK.&&
.NEAR TERM /THROUGH TONIGHT/...
DECAYING MCS OVR SRN QUEBEC ATTM ABOUT TO ENTER FAR WRN MAINE...
OTHERWISE...PARTLY TO MOSTLY CLOUDY SKIES ACROSS THE FA ATTM W/
SOME FOG ACROSS THE N. NOT MUCH CHANGE IN THE OVERALL PTRN ACROSS
OUR AREA LAST 24 HRS AT LEAST IN THE UPPER LEVELS OF THE ATMOS AS
BRISK WNW FLOW ALOFT PERSISTS W/ OCNL DISTURBANCES EMBEDDED IN
THIS FLOW. IN THE LOWER LEVELS - A VRY WARM AND HUMID SWRLY FLOW
IS NOW IN PLACE ACROSS THE ENTIRE REGION W/ TDS GENERALLY IN THE
LOWER TO MID 60S. THE DECAYING MCS IS SHOWN BY THE SHORTER TERM
MODELS SUCH AS THE RUC TO CONT TO MV ESEWRD AND HOLD TOGETHER ENUF
TO HAVE SOME IMPACT ON OUR WRN ZNS ERLY TDY THEN ACROSS OUR S
CENTRAL ZNS THRU THE AM HRS AND POPS ACROSS THESE AREAS WILL
REFLECT THIS. OTHERWISE...ANOTHER UPPER DISTURBANCE IS FCST TO
SLIDE ESEWRD ACROSS THE FA LATER TDY AND PROVIDE ANOTHER UPTICK IN
SHOWERS/TSTMS.
UNLIKE SUN...WHERE MOST ACTION WAS S OF THE AREA - APPEARS TDY
THAT THINGS HAVE SHIFTED A LITTLE FURTHER N W/ THE INTRUSION OF
THE WARMER AND MORE HUMID AIR. AS A RESULT...WILL CARRY MAINLY CHC
POPS ACROSS THE REMAINDER OF THE FA TDY INTO THIS EVE W/ ACTIVITY
EXPECTED TO AGAIN WEAKEN/DISSIPATE LATER THIS EVE AS THIS UPPER
DISTURBANCE MVS AWAY FROM THE REGION. THIS WILL SET THE STAGE FOR
MORE PATCHY FOG W/ THE FOG PROBABLY A LITTLE MORE WDSPRD THAN THIS
AM W/ THE HUMID AIRMASS PERSISTING. TEMPS TDY WILL BE A LITTLE
TRICKY... CLDS AND SHOWERS WILL NO DOUBT HAVE SOME IMPACT AND
PROBABLY KEEP MOST AREAS FROM REACHING FULL POTENTIAL TDY.
STILL...A LITTLE SUNSHINE FROM TIME TO TIME IS EXPECTED AND WILL
GO A LONG WAY IN HEATING THINGS UP SO WILL HANG ONTO HIGHS INTO
THE LOWER 80S N W/ MID TO PSBLY UPPER 80S CENTRAL AND INTERIOR
DOWNEAST...&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
PERIOD WILL BEGIN WITH A SURFACE HIGH SETUP IN THE ATLANTIC AND
BOUNDARY DRAPED JUST TO THE NORTH OF THE REGION. THE SURFACE HIGH
WILL CONTINUE TO PUMP WARM AND MOIST AIR INTO THE REGION. GUIDANCE
IS IN FAIR AGREEMENT WITH THE BOUNDARY AND SURFACE LOW BEGINNING TO
DROP SOUTH THROUGH THE DAY ON TUESDAY. THIS COMBINED WITH BETTER
UPPER LEVEL DYNAMICS WITH THE REGION LOCATED IN THE FAVORABLE
RIGHT ENTRANCE REGION OF UPPER LEVEL JET ENHANCING DIVERGENCE
ALOFT. ALSO WITH WARM AND MOIST UNSTABLE AIR IN PLACE CAPE VALUES
WILL BE GENERALLY BETWEEN 500 TO 1500 J/KG. THESE DYNAMICS WILL
MAKE IT POSSIBLE TO HAVE SOME MORE ENHANCED THUNDERSTORM ACTIVITY
TUESDAY AFTERNOON AND EVENING. RIGHT NOW THINKING IS THERE WILL BE
THE POTENTIAL FOR SMALL HAIL AND GUSTY WINDS BUT THIS MAY NEED TO
BE ENHANCED FURTHER IF DYNAMICS CONTINUE TO COME TOGETHER. BEST
CHANCES STILL LOOK TO BE ACROSS THE NORTHERN AND CENTRAL PORTIONS
OF THE REGION WHERE BEST SUPPORTING DYNAMICS ARE PRESENT.
THERE IS SOME MODEL DIVERGENCE FOR WEDNESDAY WITH THE MOST OF
GUIDANCE WANTING TO KEEP THE LOW PRESSURE ACROSS THE REGION WHILE
THE 23/12Z ECMWF WANTS TO KEEP IT DRIER. RIGHT NOW WILL KEEP
DECENT CONSISTENCY WITH PREVIOUS FORECAST WITH MORE SHOWERY TYPE
ACTIVITY. TEMPERATURES FOR WEDNESDAY LOOK TO BE COOLER ALTHOUGH
THIS WILL BE HIGHLY DEPENDENT ON CLOUD COVER.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE GUIDANCE IS STILL A BIT DIVERGENT IN THE BEGINNING OF THE LONG
TERM PERIOD. THE 24/00Z GFS/GEM WANTS TO HOLD ON TO THE BOUNDARY
AND SURFACE LOW A BIT LONGER THAN THE 23/12Z ECMWF FOR WEDNESDAY
NIGHT. THEN WE WILL SEE ANOTHER STRONG UPPER LEVEL DISTURBANCE
ACROSS THE GREAT LAKES CONTINUE TO PROGRESS EAST. ALL THE LONG
RANGE GUIDANCE INDICATES THIS MOVING EAST BUT WITH SLIGHT DIFFERENCES
IN TIMING. GENERALLY IT LOOKS LIKE THIS SYSTEM WILL BEGIN
PROGRESSING INTO THE REGION THURSDAY AFTERNOON. RIGHT NOW THE
GUIDANCE ALSO WANTS INDICATE THIS UPPER LEVEL LOW BECOMING QUASI-
STATIONARY GENERALLY ACROSS THE GREAT LAKES AND OHIO VALLEY. THIS
WOULD KEEP THE REGION IN A ACTIVE PATTERN THROUGH MUCH OF THE LONG
TERM PERIOD. THIS QUASI-STATIONARY TROUGH SETUP IS ALSO GENERALLY
SUPPORTED BY THE 23/12Z GFS/ECMWF RESPECTIVE ENSEMBLE MEAN. HIGH
AND LOW TEMPERATURES FOR THE PERIOD WILL GENERALLY BE NEAR NORMAL.
&&
.AVIATION /07Z MONDAY THROUGH FRIDAY/...
NEAR TERM: VRBL CONDS ACROSS THE AREA THIS AM W/ SOME IFR IN FOG
ACROSS THE N TO VFR CONDS ACROSS THE S. EXPECT FOG TO DISSIPATE
ERLY THIS AM W/ PREDOM VFR CONDS TDY EXPECT OCNL MVFR TO BRIEF IFR
PSBL IN ANY SHOWERS/TSTMS. FOG WILL AGAIN BE A THREAT TNGT ALONG
W/ A CONTD CHC OF SHOWERS AND PSBL THUNDER...
SHORT TERM: MOST SITES LOOK TO STAY VFR THROUGH THE PERIOD WITH
THE EXCEPTION OF THOSE SITES THAT RECEIVE SHOWER AND THUNDERSTORM
ACTIVITY. THIS WILL BE MORE LIKELY FOR THE NORTHERN SITES.
&&
.MARINE...
NEAR TERM: WINDS/SEAS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS THRU TONIGHT. VISIBILITIES COULD BE REDUCED IN PATCHY
FOG TODAY AND IN MORE WDSPRD AREAS OF FOG TNGT.
SHORT TERM: MARINE: NO HEADLINES EXPECTED AT THIS TIME WITH SEAS
GENERALLY STAYING 2 TO 4 FT AND WINDS 10 TO 15 KT. VISIBILITIES
COULD BE REDUCED WITH SHOWERS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...KHW
SHORT TERM...JORDAN
LONG TERM...JORDAN
AVIATION...KHW/JORDAN
MARINE...KHW/JORDAN
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
ISSUED BY NATIONAL WEATHER SERVICE CHARLESTON WV
741 PM EDT TUE JUN 25 2013
.SYNOPSIS...
WARM AND HUMID CONDITIONS WILL CONTINUE. IN ADDITION...SEVERAL
UPPER LEVEL DISTURBANCES WILL BRING THE CHANCE FOR SHOWERS AND
THUNDERSTORMS UNTIL A COLD FRONT PASSES ON THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
730 PM UPDATE...
LINE OF STRONG AND SEVERE THUNDERSTORMS CONTINUES TO PUSH EASTWARD
ACROSS THE AREA THIS EVENING. BUMPED UP POPS FOR MUCH OF THE AREA
TO CATEGORICAL WITH THE SQUALL LINE AND CONTINUED LIKELY POPS
BEHIND THE MAIN LINE FOR A FEW HOURS IN TRAILING PRECIP REGIME.
SOUTHERN END OF LINE SLOWING IN ITS FORWARD PROGRESSION. STILL
EXPECT MAIN LINE TO EXIT AREA TO THE SOUTHEAST BY 01Z-02Z TIME
FRAME.
PREVIOUS DISCUSSION...
LOOKS LIKE CONVECTION WILL CONTINUE TO DEVELOP IN THE VICINITY OF
THE TRAILING OUTFLOW BOUNDARY THAT IS CURRENTLY SET UP ROUGHLY
ALONG THE I-80 CORRIDOR. WHILE THE MESOSCALE ANALYSIS SUGGESTS
PLENTY OF INSTABILITY...WITH CAPE IN EXCESS OF 2500-3000
J/KG...SHEAR CONTINUES TO REMAIN MARGINAL AT BEST. THIS HAS LEAD
TO VERY DISORGANIZED STORMS THUS FAR.
HOWEVER...SEVERAL OF THE HI RES MODELS ARE CONTINUING TO SUGGEST A
BIT MORE ORGANIZATION BY LATE THIS AFTERNOON. BOTH THE HRRR AND
4KM NAM SUGGEST THAT A MCS WILL DEVELOP AND PROPAGATE ALONG THIS
SLOWLY SINKING BOUNDARY MENTIONED ABOVE...CROSSING THE FORECAST
AREA BY 8PM. NOT COMPLETELY SOLD ON MCS DEVELOPMENT BUT...SINCE THE
DETERMINISTIC MODELS CONTINUE TO SHOW A BREAK DOWN IN THE RIDGE AS
A WEAK SHORTWAVE MOVES ACROSS THE GREAT LAKES THIS
EVENING...BELIEVE THIS COULD BE ENOUGH TO AT LEAST HELP SOME STORMS
REACH STRONG TO SEVERE LEVELS. FOR NOW...CONTINUED THE SCATTERED
COVERAGE WORDING FOR THUNDERSTORMS AND WILL CONTINUE TO MONITOR
UPSTREAM TRENDS.
A SIMILAR SCENARIO REMAINS IN PLACE FOR WEDNESDAY. MODEL
SOUNDINGS CONTINUE TO SUGGEST A BRIEF NORTHWESTERLY WIND COMPONENT
AT MID LEVELS COULD POSSIBLY HELP SUPPORT STRONGER STORMS WEDNESDAY
AFTERNOON...BUT COVERAGE REMAINS UNCERTAIN.
A PERSISTENCE FORECAST FOR TEMPERATURES WAS MAINTAINED THROUGH THE
PERIOD.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
STRONG AGREEMENT AMONGST NCEP CHAIN ON A MODEST MID LVL WAVE
CROSSING THE WESTERN GREAT LAKES WED NGT INTO THUR. CONFIDENCE HAS
INCREASED TO RAISE POPS FURTHER INTO THE CATEGORICAL RANGE. TIME OF
DAY DOES NOT LEND ITSELF TO HAZARDOUS WEATHER...SO PRESENT THINKING
IS WE EXPERIENCE A WELCOME RAIN WITH SCATTERED SUB-SEVERE STORMS.
PROGRESSIVE PATTERN WITH IMPULSES CROSSING EVERY 18 TO 24 HOURS DOES
NOT LEND ITSELF MUCH TIME FOR INSERTION OF DRY WEATHER. CONTINUED
WITH CHANCE POPS THE BALANCE OF SHORT TERM AS INHERITED DATASET
PRESENTLY ILLUSTRATES.
THERMODYNAMIC PARAMETERS ARE NOT IMPRESSIVE FRIDAY FOR A SEVERE
THREAT DESPITE A STRONG KINEMATIC ENVIRONMENT. SBCAPES PUSH 2.0
KJKG-1 W OF I-77 ALONG WITH BETTER BL EQUIV POT TEMP ADV...BUT MID
LVL LAPSE RATES ARE MARGINAL /AROUND 5CKM-1 OR LESS/.
AS H5 CYCLONE COILS UP ACRS EASTERN CANADA...ASSOCIATED HEIGHT FALLS
WILL BRING COOLER AND LESS HUMID WEATHER OVER THE WEEKEND.
INTERSECTION OF INSTABILITY AND LIFT WILL COINCIDE ON THE LEADING
EDGE OF H7-H3 DCVA SUPPORTING RW/TRW DEVELOPMENT CLOSER TO LAKE
ERIE. A COLD FRONT ENCROACHES SAT NGT BUT LIMITED MOISTURE
ACCOMPANIES IT.
DUE TO STAGNANT PATTERN LEANED HEAVILY ON BIAS CORRECTED MOSGUIDE
GRIDS FOR TEMPS WHICH HAVE PREFORMED WELL RECENTLY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A SERIES OF SHRTWVS WL CONT TO DROP SE ACRS THE GT LKS RGN THRU
MOST OF THE PD. THIS WL SPPRT SHWR/TSTM CHCS AT LEAST THRU SAT.
MOISTURE MORE IN QUESTION BY SUN SO ONLY MENTIONED SLGT CHC POPS
THEN. OTRW...WENT NO HIGHER THAN CHC POPS ATTM DUE TO TIMING
UNCERTAINTIES IN INDIVIDUAL SHRTWVS. EXP TEMPS NR OR A SLGTLY ABV
SEASONAL AVGS UNTIL HIGH PRES BLDS IN LT IN THE PD WITH SLGTLY BLO
AVG READINGS.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDTIONS EXPECTED TO PREVAIL THROUGH THE VALID PERIOD. A LINE
OF STRONG AND SEVERE THUNDERSTORMS HOWEVER CONTINUING TO MAKE ITS
WAY EAST AND SOUTHEAST ACROSS THE AREA...AND IS CURRENTLY THROUGH
ALL TERMINALS EXCEPT KLBE. CIGS ARE EXPECTED TO REMAIN LOW VFR
WITH THIS ACTIVITY...BUT AS USUAL INTERMITTENT MVFR TO IFR VIS IS
POSSIBLE WITH THE STRONGER SHOWERS AND THUNDERSTORMS. BRIEF VERY
STRONG WINDS ARE THE MAIN THREAT WITH THE MAIN LINE OF THUNDERSTORMS.
AFTER 06Z...PATCHY MVFR VIS IN BR IS POSSIBLE FOR MANY TAF SITES
PARTICULARLY NEAR SUNRISE WEDNESDAY MORNING.
OUTLOOK.../WEDNESDAY THROUGH SATURDAY/...
VFR IS EXPD MUCH OF THE TIME...ALTHOUGH A SERIES OF DISTURBANCES
WL BRING DAILY CHCS OF SHWRS/TSTMS WITH THE HIGHEST CHC BEING
THU/THU NGT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
743 PM EDT TUE JUN 25 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 430 PM EDT TUE JUN 25 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A LOW AMPLITUDE PATTERN WITH A
TROUGH INTO THE PAC NW AND A RIDGE FROM THE UPPER MS VALLEY INTO
MANITOBA. THE MAIN UPSTREAM SHORTWAVE TROUGH EXTENDED FROM ERN
MONTANA INTO WRN SD. AT THE SFC...A WEAK RIDGE AND LIGHT PRES
GRADIENT PREVAILED OVER THE THE REGION ALLOWING PROMINENT LAKE
BREEZES TO DEVELOP. CAPPING HAS BEEN STRONG ENOUGH TO SUPPRESS
CONVECTION THROUGH 20Z DESPITE LOW LEVEL CONV...INLAND MLCAPE VALUES
TO NEAR 1500 J/KG AND CU/TCU LINE DEVELOPMENT. MIXING HAS ALSO BEEN
STRONG ENOUGH TO DROP DEWPOINTS INTO THE MID AND UPPER 50S NEAR THE WI
BORDER
TONIGHT...POTENTIAL REMAINS FOR SOME ISOLD SHRA/TSRA
DEVELOPMENT...MAINLY OVER THE SOUTH NEAR THE LAKE BREEZE BOUNDARIES.
WITH THE LOSS OF DAYTIME HEATING...ANY PCPN CHANCES WILL ALSO
DIMINISH THIS EVENING. EVEN WITH FAVORABLE RADIATIONAL COOLING
OVERNIGHT...ENOUGH LOW LEVEL MOISTURE REMAINS TO KEEP MIN TEMPS FROM
DROPPING MUCH BELOW 60F. SOME PATCHY FOG MAY ALSO DEVELOP.
WED...THE NRN PLAINS SHRTWV AND ASSOCIATED SFC TROUGH MOVING INTO
THE WRN LAKES WILL BE THE FOCUS FOR SHRA/TSRA DEVELOPMENT. THE
MODELS WERE IN RELATIVELY GOOD AGREEMENT BRINGING THE HIGHER PCPN
CHANCES INTO THE WEST HALF OF THE CWA DURING THE AFTERNOON. THE
AIRMASS OVER REGION SHOULD AGAIN ALLOW TEMPS TO CLIMB INTO THE LOWER
80S INLAND AND BEFORE LAKE BREEZES TAKE OVER. MLCAPE VALUES MAY
AGAIN CLIMB TO AROUND 1500 J/KG BUT RELATIVELY MODEST SHEAR VALUES
WILL LIMIT STRONG/SEVERE STORM POTENTIAL.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 430 PM EDT TUE JUN 25 2013
OVERALL PATTERN WILL EVOLVE INTO AN AMPLIFIED ONE FOR LATE JUNE
STANDARDS DURING THE LATE WEEK PERIOD WITH INTENSE UPPER RIDGING
DEVELOPING OVER THE WESTERN U.S. AND TROUGHING DEVELOPING OVER THE
GREAT LAKES AND EASTERN U.S. AS HAS BEEN THE CASE OVER THE LAST
SEVERAL DAYS TIMING OF A BETTER PRECIP CHANCES DURING THE NEXT
COUPLE OF DAYS WILL REMAIN A CHALLENGE. CONFIDENCE IS PRETTY HIGH
THAT ALL AREAS WILL SEE AT LEAST SOME RAINFALL BETWEEN THE WEDNESDAY
NIGHT THROUGH SATURDAY TIME PERIOD. HOWEVER...MORE OF THAT TIME WILL
BE DRY RATHER THAN RAINY.
WHILE SCATTERED POPS SEEM THE WAY TO GO FOR THIS TIME PERIOD...WILL
GO WITH SLIGHTLY HIGHER POPS DURING THE WED NIGHT TIME PERIOD AS
SHORTWAVE ENERGY BEGINS TO CARVE OUT UPPER TROUGHING OVER THE GREAT
LAKES. WILL ALSO GO ON THE HIGHER END OF CHANCE POPS FOR FRIDAY INTO
SATURDAY AS MAIN TROUGH AXIS MOVES THROUGH THE AREA. A SCATTERING
OF POPS DURING THE OTHER PERIODS SEEMS REASONABLE.
WITH LIMITED INSTABILITY AND SHEAR EXPECTED...THUNDER CHANCES WILL BE
MORE IN THE ISOLATED TO SLIGHT CHANCE RANGE.
HIGH PRESSURE AND DRIER AIR SHOULD BEGIN PUSHING INTO THE AREA FROM
THE NORTH BY LATE IN THE DAY SATURDAY ENDING THE RAIN CHANCES.
UPPER TOUGHING WILL REMAIN OVER THE AREA INTO EARLY NEXT WEEK
KEEPING TEMPERATURES AT TO JUST SLIGHTLY BELOW NORMAL THROUGH THE
WEEKEND INTO MONDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 743 PM EDT TUE JUN 25 2013
THERE MAY BE SOME RADIATIONAL FOG (MVFR VIS) LATE TONIGHT AT
KIWD/KSAW. OTHERWISE...EXPECT VFR CONDITIONS AT KIWD/KCMX/KSAW THRU
AT LEAST MID AFTN WED. APPROACHING DISTURBANCE SHOULD BRING SHRA/SCT
TSRA INTO UPPER MI LATER WED AFTN. INCLUDED SHRA/VCTS AT KIWD/KCMX
LATE ALONG WITH MVFR CONDITIONS. IT WILL BE BEYOND THIS FCST PERIOD
THAT SHRA MAY AFFECT KSAW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 430 PM EDT TUE JUN 25 2013
OVERALL...WINDS ARE EXPECTED TO BE BELOW 20KTS THROUGH THE PERIOD AS
THE PRESSURE PATTERN REMAINS FAIRLY WEAK ACROSS THE AREA. WITH THE
WARM MOIST AIR OVER THE UPPER GREAT LAKES...WILL CONTINUE TO MENTION
PATCHY/AREAS OF FOG THROUGH WEDNESDAY NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...MZ
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
120 AM EDT MON JUN 24 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 418 PM EDT SUN JUN 23 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW OVER SE
SASK INTO SRN MANITOBA WITH A SHORTWAVE TROUGH EXTENDING INTO ERN ND
AND NW MN. AT THE SFC...A 999MB SFC LOW WAS LOCATED OVER THE NW CORNER
OF MN WITH A WARM FRONT EXTENDING INTO SRN LAKE SUPERIOR. CLEARING
AND AFTERNOON HEATING HAS PUSHED TEMPS INTO THE LOWER 80S OVER WRN
UPPER MI RESULTING IN MLCAPE VALUES TO AROUND 1500 J/KG. SCT
SHRA/TSRA WERE DEVELOPING OVER WRN LAKE SUPERIOR INTO NW UPPER MI
CLOSEST TO THE FORCING ASSOCIATED WITH THE ND/MN SHRTWV.
EXPECT THAT SCT SHRA/SHRA WILL CONTINUE TO DEVELOP BACK THROUGH WRN
UPPER MI LATE THIS AFTERNOON AS A WEAK TROUGH MOVES INTO THE
AREA...PER HIGH RES MODELS. INSTABILITY ALONG WITH 30-35 KT 0-6KM
SHEAR AND 20-25 KT 0-1KM SHEAR COULD SUPPORT AT LEAST ISOLD
STRONG/SEVERE STORMS...WITH STRONG WIND GUSTS AS THE MAIN HAZARD
GIVEN DCAPE VALUES INTO THE 500-1000 J/KG RANGE. EXPECT THAT THE
SHRA/TSRA WILL SPREAD INTO CNTRL UPPER MI BY 21Z-23Z AND THEN
DISSIPATE AND WEAKEN BY LATE EVENING AS THE SHRA/TSRA MOVE TOWARD
THE ERN CWA...AWAY FROM THE THE STRONGER INSTABILITY AND THE SHRTWV
FORCING.
AS THE SHORTWAVE AND LOW MOVE INTO NRN ONTARIO THE DRY SLOT AND
STRONG MID LEVEL DRYING WILL SPREAD ACROSS THE REGION LATE TONIGHT
INTO MONDAY. THIS WILL HELP MINIMIZE CHANCES FOR ADDITIONAL
CONVECTION. WITH SUNSHINE AND 850 MB TEMPS STILL AROUND 15C...TEMPS
WILL AGAIN CLIMB INTO THE LOWER 80S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 418 PM EDT SUN JUN 23 2013
GENERAL AGREEMENT IN OVERALL LOOK OF LARGER SCALE PATTERN INTO NEXT
WEEKEND THOUGH DETAILS AND SPECIFICS REMAIN UNCERTAIN. TO START ON
MONDAY EVENING...FAIRLY STRONG SHORTWAVE TROUGH WILL BE HEADING EAST
ACROSS NORTHERN ONTARIO LEAVING RIDGING IN ITS WAKE OVER NORTHERN
PLAINS. SFC FRONT AND POOL OF SFC-H85 MOISTURE ALONG THE BOUNDARY
DRIVES SOUTH OF CWA BY LATE MONDAY EVENING RESULTING IN GENERALLY
QUIET AND LESS HUMID WEATHER INTO MUCH OF TUESDAY. GFS AND ECMWF
AGREE HERE...WHILE THE GEM-NH AND THE UKMET DO NOT PUSH WARM FRONT
FAR ENOUGH SOUTH TO KEEP CHANCES OF SHRA/TSRA OUT OF CWA. WILL LEAN
ON THE MORE CONSISTENT ECMWF IDEA WHICH IS SUPPORTED BY WPC HAND
DRAWN SFC MAP.
WITH WARM FRONT AND EDGE OF SFC BASED-MUCAPE MOST LIKELY STILL SOUTH
BY TUESDAY AFTN...WONDER IF MOST AREAS STAY DRY THROUGH TUESDAY. ANY
SHRA/TSRA THAT FORM MONDAY NIGHT INTO TUESDAY MORNING SHOULD STAY
SOUTH OF CWA PER H85-H3 THICKNESSES AND FORWARD PROPAGATING CORFIDI
VECTORS AND EVEN THE MEAN LAYER WIND. INTO TUESDAY NIGHT...ECMWF AND
GFS STILL HAVE SHORTWAVE CRASHING THROUGH TOP EDGE OF LARGER SCALE
RIDGING. WAVE MAY AID IN BRINGING AT LEAST H85 FRONT FAR ENOUGH
NORTH THAT SOUTHERN TIER COULD BE AFFECTED BY SHRA/TSRA TUESDAY
NIGHT AND MUCH OF THE CWA COULD SEE SHRA/TSRA ON WEDNESDAY. GFS
STRONGER WITH THIS WAVE SO MUCH THAT IT PUSHES SFC WARM FRONT INTO
CWA ON WEDNESDAY. PV ANAMOLY THAT GFS CARRIES IN HERE ON WEDNESDAY
TRACKS BACK TO SOUTH EDGE OF STRONG UPR LOW OVER THE ALLUTIANS THIS
MORNING. WAVE LOOKS PRETTY VIGOROUS ON WV LOOP. ECMWF HAS BETTER
TRACK RECORD IN THE EXTENDED...BUT WILL BLEND SOME OF THE GFS IDEA
IN AS WELL SINCE IT SEEMS TO HAVE SOME MERIT.
TROUGH AND HIGHER SFC-H85 DWPNTS PUSH THROUGH AREA WEDNESDAY EVENING
AND COOLER AIR ARRIVES LATER ON THURSDAY. GFS QUICKER AND STRONGER
AS WELL AS FARTHER SOUTH WITH SHORTWAVE TROUGH DIGGING ACROSS UPR
LAKES ON THURSDAY WHILE THE ECMWF SHOWS MORE SEPARATION BTWN THE
WAVE ON WEDNESDAY AND THAT STRONGER TROUGHING. GFS HAS TENDENCY TO
BRING SYSTEMS IN TOO QUICKLY AND ITS SOLUTION VERIFYING AT 12Z
THURSDAY HAS SHOWN TOO MUCH INCONSISTENCY TO PUT MUCH STOCK IN IT AT
THIS POINT. ECMWF HAS TRENDED A BIT SHAPRER WITH TROUGH BUT OVERALL
HAS BEEN MUCH MORE CONSISTENT THAN GFS. WILL PREFER THAT IDEA FOR
NOW. RESULT WILL BE SCT SHRA/TSRA...MAYBE EVEN NMRS FOR A TIME
WEDNESDAY OR WEDNESDAY EVENING...THEN DIMINISHING WITH LOSS OF
INSTABILITY AXIS LATER WEDNESDAY NIGHT. POTENTIAL FOR ANOTHER ROUND
OF SCT SHRA/TSRA DURING PEAK HEATING ON THURSDAY AS AIRMASS OVER THE
REGION IS STILL A BIT UNSTABLE /MLCAPES UP TO 1000 J/KG/ WHILE WNW
FLOW ALOFT INCREASES ON SOUTH EDGE OF UPPER TROUGH. LIGHT AND
VARIABLE SFC WINDS COULD RESULT IN LAKE BREEZE CONVERGENCE AS WELL.
ALWAYS HAVE TO WATCH OUT FOR WNW-NW FLOW ALOFT AS THAT PATTERN WITH
SUFFICIENT INSTABILITY IS ONE THAT CAN RESULT IN AT LEAST SOME
CHANCE OF SEVERE WEATHER.
UPPER TROUGH DOMINATES ON FRIDAY WITH A BIT COOLER AND UNSETTLED
WEATHER. NO TSRA EXPECTED ON FRIDAY AS COOLER TEMPS ALOFT/STEEPER
LAPSE RATES SETUP FROM NORTHERN ONTARIO INTO THE LOWER GREAT LAKES.
COULD BE SHRA AT TIMES THOUGH AS SMALLER SCALE SHORTWAVES ROTATE
AROUND PRIMARY UPPER TROUGH. FRIDAY NIGHT INTO SATURDAY MAY BE KIND
OF BLUSTERY ALONG LK SUPERIOR AND WITH ONSHORE WINDS SWIM RISK MAY
BE HIGHER TO START THE WEEKEND. SMALL CHANCES OF SHRA MAY LINGER
INTO SATURDAY AS WELL. TEMPS SOME AREAS FRIDAY INTO SATURDAY MAY
END UP MORE THAN 10 DEGREES BELOW NORMAL. HIGH PRESSURE BUILDS IN
FOR LATER IN THE WEEKEND...RESULTING IN TEMPS BOUNCING UP AT LEAST
TOWARD NORMAL. NEXT SHORTWAVE IN WNW FLOW APPEARS LATE IN THE WEEKEND
SO HAVE POPS MOVING BACK IN FOR LATE SUNDAY. NO REAL WARM TEMPERATURES
SEEN NEXT WEEKEND OR EVEN INTO EARLY NEXT WEEK AS TROUGHING ALOFT
OVER EASTERN CANADA AND GREAT LAKES KEEPS WARM AIR RESTRICTED TO
WESTERN AND SOUTHERN PORTIONS OF CONUS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 120 AM EDT MON JUN 24 2013
WITH HUMID AIR MASS IN PLACE AND SOME RAINFALL ACROSS THE AREA
YESTERDAY...MAY SEE SOME FOG OVERNIGHT...REDUCING VIS TO MVFR. GIVEN
STRONGER WINDS JUST ABOVE NOCTURNAL INVERSION THAT WILL INDUCE
SUFFICIENT MECHANICAL MIXING...FOG SHOULDN`T BECOME TOO THICK TO
REDUCE VIS BLO MVFR. OTHERWISE...VFR CONDITIONS SHOULD PREVAIL THRU
THE PERIOD AT KIWD/KCMX/KSAW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 418 PM EDT SUN JUN 23 2013
WINDS SHOULD REMAIN 25 KTS OR LESS THROUGH THE UPCOMING WEEK. MAIN
HAZARD WILL BE SCT THUNDERSTORMS TONIGHT AND FOG. DENSE
FOG ADVISORIES HAVE BEEN EXTENDED THROUGH TONIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 5 AM EDT /4 AM CDT/ EARLY THIS MORNING
FOR LSZ162-263>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1100 PM CDT TUE JUN 25 2013
.UPDATE...ADDED PATCHY FOG TO WISCONSIN ZONES AND NEAR TWIN
PORTS AFTER 08Z PER SFC T/TD SPREADS AT THIS HOUR. LATEST HRRR 3KM
FCST OF LOWERING VISIBILITY ALSO SUPPORTS THIS IDEA ALONG WITH
PERSISTENCE FROM PREVIOUS NIGHTS ALTHOUGH EVENTUALLY MORE HIGH LVL CLOUD
COVER WILL WORK ITS WAY IN FROM THE WEST. CONVECTIVE COMPLEXES
CONTINUE NEAR SFC LOW/TROF OVER ERN NODAK/MN BORDER IN AN AREA OF
MAXIMUM 85H MSTR TRANSPORT AND WELL DEFINED 85/30H THICKNESS
DIFFLUENCE. 03Z HRRR SIM REFL BRINGS REMNANTS OF THIS AREA INTO
NWRN CWA AFTER 08Z WITH A SECONDARY LINE MOVING INTO WRN/SWRN CWA
AROUND 15Z. NSSL WRF MAKES MORE OF A CASE FOR CONVECTION TO
MAINTAIN SOME ORGANIZATION AS IT MOVES INTO CWA AND HEADS TOWARDS
TWIN PORTS AROUND 12Z. USING PROGRESSION OF MID LVL SHEAR AXIS
PUTS HIGHEST POPS OVER ERN CWA WED AFTN. INCREASED POPS IN THIS
AREA. ALSO RAISED MAX TEMPS FROM TWIN PORTS WEST AS IT APPEARS
THAT PROGRESSION OF WESTERLY FLOW IN MIXING LAYER MAY ALLOW SOME
LATE DAY WARMING.
&&
.PREV DISCUSSION... /ISSUED 703 PM CDT TUE JUN 25 2013/
UPDATE...UPDATE TO DELAY ARRIVAL OF POPS A FEW HRS AS MAIN FOCUS
OF ACTIVITY IS OCCURRING WITHIN 85H THETAE AXIS ASSOCIATED WITH SFC
LOW/TROF OVER CENTRAL DAKOTAS. AS STATED IN PRIOR DISCUSSION
ATMOSPHERE IS QUITE UNSTABLE OVER CWA. WITH BDRY LYR DECOUPLING...SPC
MESO SHOWS AREAL COVERAGE OF SBCIN INCREASING. BOTH NSSL WRF-ARW
AND SPC WRF-NMM SIM REFLECTIVITY PRODUCTS DEPICT CURRENT
SITUATION DECENTLY REGARDING NODAK LINE OF CONVECTION. FCST
INDICATES CONSIDERABLE WEAKENING OF THE LINE AFTER IT CROSSES
NODAK/MN STATE LINE AND ENTERS WRN CWA BY 09Z. WILL MONITOR
ACTIVITY TO THE WEST THIS EVENING AND AMEND ACCORDINGLY.
PREV DISCUSSION... /ISSUED 649 PM CDT TUE JUN 25 2013/
AVIATION...00Z TAF ISSUANCE...
VFR CONDITIONS ACROSS NE MINNESOTA AND NW WISCONSIN WILL CONTINUE
THIS EVENING. BR AND/OR FG IS POSSIBLE LATE TONIGHT AND EARLY
WEDNESDAY MORNING. THE MOST LIKELY LOCATIONS FOR FG ARE KDLH AND
KHYR. STORMS IN THE NORTHERN PLAINS WILL APPROACH THE WRN CWA
AFTER MIDNIGHT. MOST LIKELY TIME FOR RW/TRW AT KINL/KBRD WOULD BE
LATE MORNING/EARLY AFTN...WITH AFTN HRS MORE LIKELY NEAR
KHIB/KDLH/KHYR. WILL TRY TO NARROW WINDOW IN NEXT FCST AT 06Z.
PREV DISCUSSION... /ISSUED 315 PM CDT TUE JUN 25 2013/
SHORT TERM...TONIGHT AND WEDNESDAY...
AT 300 PM VISIBLE SATELLITE IMAGERY
DEPICTED MOSTLY SUNNY TO PARTLY CLOUDY SKIES ACROSS THE NORTHLAND.
TEMPERATURES RANGED FROM 87 AT KHIB TO 85 AT KBRD...83 AT
KHYR...85 AT KDLH. COOLER READINGS WERE FOUND NEAR LAKE SUPERIOR
WITH 70 DEGREES AT KDYT/DULUTH HARBOR...67 LAKESIDE AT SILVER BAY
AND A CHILLY 50 DEGREES AT GRAND MARAIS.
THE FORECAST AREA WILL REMAIN SITUATED BETWEEN A H85 LOW/SFC TROUGH
APPROACHING FROM THE DAKOTAS...AND A WARM FRONT LIFTING INTO
NORTHERN WISCONSIN OVERNIGHT. ALTHOUGH INSTABILITY IS HIGH...LATEST
MODEL RUNS ARE IN AGREEMENT THAT THERE IS MUCH LESS CONVECTION
ASSOCIATED WITH THESE BOUNDARIES AS THEY PASS OVER THE REGION THROUGH
THE NEXT 24 HRS...MAINLY DUE TO THE LACK OF MID LEVEL MOISTURE.
ALTHOUGH THE FRONT IS EXPECTED TO TRIGGER SCATTERED SHOWERS AND
THUNDERSTORMS...HAVE DECREASED POPS OVERNIGHT AND WEDNESDAY FROM
PREVIOUS FORECAST DUE TO A LACK OF MID LEVEL MOISTURE TO SUPPORT
WIDESPREAD ACTIVITY. HOWEVER...THE ATMOSPHERE REMAINS VERY
UNSTABLE WITH SUFFICIENT CAPE TO SUPPORT STRONG TO POSSIBLY
SEVERE STORMS OVERNIGHT.
THE SFC BOUNDARY WILL PUSH OUT OF THE DAKOTAS LATE TONIGHT...REACH
NORTH CENTRAL MINNESOTA WEDNESDAY MORNING...THEN TRACK ACROSS THE
MINNESOTA ARROWHEAD AND NORTHERN WISCONSIN ZONES WEDNESDAY
EVENING. AS THE FRONT PASSES...EXPECT WINDS TO SWITCH OUT OF THE
NORTHWEST. GUSTS TO 20 MPH WILL BE FOUND IN THE BRAINERD LAKES
AREA...MAINLY LATE IN THE DAY. TEMPERATURES WILL TOP OUT IN THE
LOW 80S.
HAVE
PULLED BACK ON POPS TONIGHT AND WEDNESDAY TO ONLY HIGH CHANCE POPS
WITH SCATTERED WORDING. HOWEVER...NAM BUFR SOUNDINGS AND RUC
PROFILES SHOW SUFFICIENT CAPE TO SUPPORT STRONG TO POSSIBLY SEVERE
STORMS OF THE ONES THAT WILL DEVELOP.
LONG TERM [WEDNESDAY NIGHT - MONDAY]
A WEAK STATIONARY FRONT WILL STRETCH FROM THE CENTRAL CANADIAN
PROVINCES...OVER THE GREAT LAKES...AND INTO THE EASTERN UNITED
STATES DURING THE BEGINNING OF THE PERIOD. ITS PROXIMITY AND THE NW
FLOW OVER THE NORTHLAND WILL COULD HELP CAUSE PRIMARILY DAYTIME
HEATING DRIVEN SHOWERS AND THUNDERSTORMS. THE NORTH AND EASTERN
FORECAST AREA HAVE THE BEST CHANCE OF PCPN. THE STATIONARY FRONT
SHOULD THEN SWING THROUGH THE NORTHLAND LATE THIS WEEK AS A WEAK
COLD FRONT...CONTINUING THE LOW CHANCES OF SHOWERS AND THUNDERSTORMS
INTO SATURDAY EVENING. THE MODELS ARE INCREASING INDICATING THAT
HIGH PRESSURE WILL MOVE INTO THE UPPER MIDWEST EARLY NEXT WEEK AND
LIKELY PROVIDE DRY WEATHER FOR SUNDAY AND MONDAY. TEMPERATURES
SHOULD BE SLIGHTLY ABOVE NORMAL THURSDAY...NEAR NORMAL
FRIDAY...SLIGHTLY BELOW NORMAL SATURDAY...AND THEN RETURNING TO NEAR
NORMAL EARLY NEXT WEEK.
&&
.POINT TEMPS/POPS...
DLH 62 77 59 80 / 10 60 40 40
INL 65 81 60 79 / 40 70 50 40
BRD 67 84 63 83 / 40 40 20 10
HYR 62 80 60 83 / 20 50 40 40
ASX 59 77 56 80 / 10 50 50 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...CANNON
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1017 PM CDT Tue Jun 25 2013
.UPDATE...
Issued at 1014 PM CDT TUE JUN 25 2013
Models continue to have difficulty grasping onto how convection will
unfold tonight. If 00z NAM and latest HRRR were on track we`d already
have an a convective complex forming over eastern NE and northeast
KS. However the latest radar and satellite data shows only a few
isolated cells over eastern NE. With the h7 shortwave axis, per SPC
analysis, now along the NE/IA state line trailing into central KS
focus for a convective complex is shifted eastward into central IA
where a considerable accas field is noted. HRRR and NAM both
eventually latch onto this area over the next few hours and spread
convection into northeast MO. Given the extensive accas field and
some new cells popping up over central IA will highlight northeast MO
with highest PoPs overnight.
&&
.SHORT TERM...(This Evening through Wednesday)
Issued at 405 PM CDT TUE JUN 25 2013
Convection across eastern Kansas, which kept our morning
temperatures rather pleasant thanks to the cloud cover, finally
dissipated in the early afternoon, allowing the sun to get to work
heating things up. As the cloud cover has moved off, readings have
begun jumping quickly towards the low 90s. The atmospheric
conditions that will prevail over the next couple of days will be
quite similar to today, only without the cooling effect from morning
convection.
Stormy activity later tonight is expected to get going in eastern
Nebraska and Iowa late tonight on the nose of a nocturnal jet.
Currently, expectations are that the hot and dry air that is
advecting in today -- 700mb temperatures > 13C -- will effectively
cap off much of eastern Kansas and western Missouri to any overnight
convection. Thoughts are that any activity in Iowa overnight will
likely put down a cold pool that could push some storms through north
central or northeast Missouri early Wednesday morning. However, this
activity is not expected to impact our temperatures
appreciably...though damaging winds and torrential rain will be
possible with these early morning storms.
Wednesday and into Thursday, the lack of cloud cover from storms
will allow temperatures to quickly bound into the 90s each day.
Light winds and dew point values in 60s to low 70s will result in
heat indices each day topping out around in the low 100s. In more
rural locations, this will be hot and humid but manageable, however
in the core of the Kansas City metropolitan area heat index values
will likely spike to around 105 degrees each day. As a result, in
consultation with the Kansas City MO Health Department, we are
opting to issue a heat advisory for the next two days. Currently,
the forecast for Friday indicates slightly cooler and drier
conditions, so at this time we are not expecting to need a heat
advisory beyond Thursday.
.LONG TERM...(Wednesday Night through Tuesday)
Issued at 405 PM CDT TUE JUN 25 2013
Backing 850 flow on Thursday will bring winds to the west and
southwest through the afternoon, potentially bringing temps at that
level even warmer than Weds with NAM and GFS showing 26C nudging
into western MO by afternoon. These temps would translate into
surface temps in the middle to upper 90s, while dewpoints remain
close to 70 degrees. This would yield heat indices across ern KS/wrn
MO in the 100-105 range, and being day 2 of such conditions could be
stressful especially for sensitive individuals in the KC core.
Amplifying upper ridge over the Rockies will strengthen the
northwest flow overhead on Thursday, allowing a front to drop
through the area Thursday night. This front will have an unstable
airmass to work with, but warm/dry air below 800 hPa may act against
widespread storms so kept PoPs limited to low chance category for
now.
Airmass behind the front will be relatively cooler with temperatures
returning into the lower/middle 80s by the weekend. An upper
shortwave trough will swing through the area on Sunday and could
spark a few showers or storms, but otherwise chances appear too low
to include a mention of precip through the remainder of the extended
period.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening)
Issued at 643 PM CDT TUE JUN 25 2013
Will be watching to see if convection develops over southeast NE
and/or western IA this evening as several models form an MCS which
drops southward through northern MO and could affect the terminals.
A moderately strong southerly low level jet will likely keep winds
up through this evening before subsiding as the higher winds aloft
shift southward. Should the surface winds decouple late this evening
will need to consider LLWS. Except for a few hours of broken cigs
around 6k ft for the first few hours of the forecast expect generally
clear skies and VFR conditions for the next 24 hours. Weak surface
trough will pass through northern and west central MO Wednesday
afternoon with winds shifting to the northwest and increasing.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...HEAT ADVISORY from 11 AM Wednesday to 7 PM CDT Thursday FOR
KSZ103>105.
MO...HEAT ADVISORY from 11 AM Wednesday to 7 PM CDT Thursday FOR
MOZ028-029-037.
&&
$$
UPDATE...MJ
SHORT TERM...Cutter
LONG TERM...Hawblitzel
AVIATION...MJ
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1014 PM CDT TUE JUN 25 2013
.UPDATE...
ISSUED AT 953 PM CDT TUE JUN 25 2013
THUNDERSTORMS CONTINUE TO DEVELOP ACROSS IL JUST NE OF OUR
FORECAST AREA ALONG AN OLD OUTFLOW BOUNDARY. STILL EXPECTING
THUNDERSTORMS TO DEVELOP ACROSS IA AHEAD OF A WEAK SHORTWAVE AND
ON THE NOSE OF A SWLY LOW LEVEL JET...THEN GROW INTO AN MCS WHICH
SHOULD EVENTUALLY DROP SEWD INTO NERN MO AND W CNTRL IL LATE
TGT/EARLY WED MRNG. LOW TEMPERATURES TGT WILL BE QUITE MILD DUE TO
SOUTHERLY SFC WINDS AND HIGH SFC DEW POINTS.
GKS
&&
.SHORT TERM...(THROUGH LATE TONIGHT)
ISSUED AT 344 PM CDT TUE JUN 25 2013
SEVERAL THINGS TO DEAL WITH IN THE SHORT TERM TONIGHT. FIRST...STORMS
DEVELOPING IN WARM SECTOR AHEAD OF MCV THAT IS SLIDING EAST
THROUGH MO FROM MCS THAT WAS OVER WESTERN MO THIS MORNING...AS
WELL AS VARIOUS OLD OUTFLOW BOUNDARIES. THIS ACTIVITY SHOULD
DIMINISH MOST LOCATIONS BY EARLY THIS EVENING...THOUGH SOME
LINGERING ACTIVITY OVER NORTHEAST MO/WEST CENTRAL IL AS MCV SLIDES
EAST. THEN MODELS CONTINUE TO SHOW NEXT MCS DEVELOPING OVER IOWA.
FORECAST CORFIDI VECTORS HAVE THIS MCS SLIDE SOUTHEAST TOWARDS
FORECAST AREA...MAYBE EVEN MORE SOUTHERLY. SO SHOULD MOVE INTO
NORTHERN PORTIONS OF FORECAST AREA BY 06Z. LATEST HRRR RUN IS EVEN
FURTHER WEST WITH INITIAL DEVELOPMENT IN SOUTHERN IOWA...SO HAVE
RAISED POPS A BIT FURTHER WEST. THERE IS A SLIGHT RISK OF SEVERE
WEATHER...WITH THE MAIN THREATS BEING LARGE HAIL AND DAMAGING
WINDS. AS FOR TEMPS...TO REMAIN RATHER MILD WITH LOWS IN THE LOW
TO MID 70S OVERNIGHT.
BYRD
.LONG TERM...(WEDNESDAY THROUGH NEXT TUESDAY)
ISSUED AT 344 PM CDT TUE JUN 25 2013
COMPLEX SCENARIO ON TAP FOR WEDNESDAY WITH LOTS OF UNCERTAINTY TO
SPECIFIC FORECAST DETAILS. THE MAIN COMPLICATING FACTOR IS THE
OVERNIGHT MCS EXPECTED TO IMPACT WESTERN IL AND PORTIONS OF ERN MO
AND WHERE IT WILL BE LOCATED AT DAYBREAK. A CONSENSUS OF MODEL
SOLUTIONS HAVE THE DECAYING MCS IN CENTERED THRU IL AT DAYBREAK WITH
THE TRAILING FLANK OR BOUNDARY LOCATED ALONG THE MS RIVER IN ERN MO.
THE VEERED NATURE OF THE TROPOSPHERIC WINDS AND WLY LLJ WOULD
SUGGEST THIS SYSTEM SHOULD CONTINUE TO MOVE SEWD IN A DECAYING STATE
THROUGH THE MORNING WITH POTENTIAL FOR SOME STORMS ON THE TRAILING
BOUNDARY. STRONG HEATING SHOULD COMMENCE DURING THE DAY WITHIN THE
WARM SECTOR AHEAD OF THE ENCROACHING COLD FRONT...AS WELL AS WEST
OR SOUTHWEST OF ANY REMNANT BOUNDARIES. THE HEATING WILL BE MORE
LIMITED WITH EASTWARD EXTENT DUE TO RESIDUAL CLOUDINESS FROM THE
MORNING...BUT THE WARM SECTOR IS EXPECTED TO BECOME VERY UNSTABLE
AND WEAKLY CAPPED WITH SBCAPE AOA 4000 J/KG. SCATTERED THUNDERSTORMS
ARE EXPECTED TO REDEVELOP IN THE AFTERNOON WITHIN THE CONFLUENT ZONE
AHEAD OF THE COLD FRONT AND WITH ANY RESIDUAL BOUNDARIES...PRIMARILY
FROM EAST CENTRAL/SE MO INTO SOUTH CENTRAL AND SW IL. DEEP LAYER
SHEAR OF 30-40 KTS AND THE AMOUNT OF INSTABILITY WOULD FAVOR
SUPERCELL AND MULTICELL MODES. THE MORNING CONVECTION AND/OR
RESIDUAL CLOUDS PRESENT SOME PROBLEMS WITH RESPECT TO THE
MAGNITUDE OF HEAT. I HAVE COOLED TEMPS SLIGHTLY FROM ST LOUIS
EASTWARD AND THIS IS HIGHLY DEPENDENT ON MORNING CLOUDS. GIVEN THE
UNCERTAINTIES I HAVE DEFER ED ON ANY HEAT ADVISORIES WITH HEAT
INDICES FORECAST IN THE 100-105 RANGE. STORMS SHOULD BE CLOSE TO
EXITING THE CWA OR WILL HAVE EXITED THE CWA BY 00Z THURSDAY.
EVEN IN THE WAKE OF THE INITIAL COLD FRONT/BOUNDARY...THURSDAY LOOKS
LIKE ANOTHER SEASONABLY HOT DAY. IN FACT...IT IS NOT TOTALLY OUT OF
THE QUESTION IT COULD BE HOTTER THAN WEDNESDAY BUT WITH LESSER
HUMIDITY. THE ANTICIPATED NORTHWEST FLOW SHORTWAVE AND SECONDARY
COLD FRONT WILL MOVE THROUGH THE AREA LATE THURSDAY NIGHT INTO EARLY
FRIDAY WITH A PROMINENT WSW LLJ AHEAD OF IT. THIS SHOULD FUEL
ANOTHER MCS WHICH WILL IMPACT PORTIONS OF THE CWA. THE MODELS
DIVERGE ON THE MCS TRACK WITH THE GREATEST PROBABILITY ATTM
APPEARING TO BE THROUGH CENTRAL MO. MUCH COOLER AIR WILL THEN
SPREAD INTO THE AREA IN THE WAKE OF THE FRONT FOR FRIDAY AND SET
THE STAGE FOR A PROLONGED PERIOD OF BELOW AVERAGE TEMPERATURES
INTO THE EXTENDED RANGES.
THE EXTENDED RANGES WILL FEATURE AN AMPLIFIED BLOCKY UPPER AIR REGIME
FROM THE ERN PACIFIC ACROSS THE CONUS INTO THE WRN ATLANTIC...WITH A
STRONG UPPER HIGH/RIDGE CENTERED IN THE WRN U.S. AND DEEP TROF IN
THE ERN U.S. A SERIES OF SHORT WAVES WILL DROP SSEWD DOWN THE
BACKSIDE OF THE UPPER TROF AND IMPACT THE AREA ON SUNDAY AND TUESDAY
REINFORCING THE "COOLER" AIR AND BRINGING A CHANCE OF SHOWERS AND
THUNDERSTORMS.
GLASS
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 647 PM CDT TUE JUN 25 2013
MAIN CONCERNS THE NEXT 24-30 HOURS WILL BE WHERE AND WHEN
THUNDERSTORMS WILL OCCUR. LINE OF THUNDERSTORMS CURRENTLY OVER
CENTRAL ILLINOIS WILL MOVE SOUTHEAST AND MAY AFFECT SOME OF THE
SMALLER AIRPORTS OVER SOUTH CENTRAL ILLINOIS. ADDITIONAL
THUNDERSTORMS ARE EXPECTED TO DEVELOP LATE THIS EVENING/OVERNIGHT
OVER IOWA...THOUGH IT IS NOT YET CLEAR WHICH WAY THEY WILL MOVE.
CURRENT THINKING IS THAT THEY WILL MOVE SOUTHEAST WHICH WILL
LIKELY BRING THEM ACROSS KUIN BETWEEN 08-11Z. IF THEY MOVE MORE
SOUTHWARD THAT EXPECTED...THEN THEY COULD AFFECT THE ST. LOUIS
METRO TAF SITES TOWARD 12Z. SOME OF THE STRONGER STORMS WILL HAVE
THE POTENTIAL TO PRODUCE WIND GUSTS IN EXCESS OF 35KTS...SOME
SMALL HAIL AND BRIEF MVFR/IFR CONDITIONS. ADDITIONAL THUNDERSTORMS
WILL DEVELOP OVER SOUTHEAST MISSOURI INTO SOUTHERN ILLINOIS LATE
MORNING OR AFTERNOON ON WEDNESDAY WITH THE BEST CHANCE STAYING
SOUTH AND EAST OF THE ST. LOUIS METRO TAF SITES. THESE STORMS WILL
HAVE THE POTENTIAL TO BE SEVERE. A COLD FRONT WILL MOVE SOUTHEAST
ACROSS THE AREA ON WEDNESDAY AFTERNOON CAUSING WINDS TO SLOWLY
VEER FROM SOUTH TO NORTHWEST THROUGH THE DAY.
SPECIFICS FOR KSTL...EXPECT MAINLY A DRY AND VFR FORECAST WITH TWO
POSSIBLE EXCEPTIONS. COMPLEX OF THUNDERSTORMS COULD MOVE A BIT
FARTHER SOUTH THAN EXPECTED WHICH COULD REACH THE TERMINAL TOWARD
12Z. ADDITIONAL THUNDERSTORMS ARE EXPECTED TO DEVELOP NEAR THE
TERMINAL AROUND 16Z...HOWEVER STORMS ARE EXPECTED TO STAY JUST
EAST AND SOUTH OF THE TERMINAL.
BRITT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
649 PM CDT TUE JUN 25 2013
.SHORT TERM...(THROUGH LATE TONIGHT)
ISSUED AT 344 PM CDT TUE JUN 25 2013
SEVERAL THINGS TO DEAL WITH IN THE SHORT TERM TONIGHT. FIRST...STORMS
DEVELOPING IN WARM SECTOR AHEAD OF MCV THAT IS SLIDING EAST
THROUGH MO FROM MCS THAT WAS OVER WESTERN MO THIS MORNING...AS
WELL AS VARIOUS OLD OUTFLOW BOUNDARIES. THIS ACTIVITY SHOULD
DIMINISH MOST LOCATIONS BY EARLY THIS EVENING...THOUGH SOME
LINGERING ACTIVITY OVER NORTHEAST MO/WEST CENTRAL IL AS MCV SLIDES
EAST. THEN MODELS CONTINUE TO SHOW NEXT MCS DEVELOPING OVER IOWA.
FORECAST CORFIDI VECTORS HAVE THIS MCS SLIDE SOUTHEAST TOWARDS
FORECAST AREA...MAYBE EVEN MORE SOUTHERLY. SO SHOULD MOVE INTO
NORTHERN PORTIONS OF FORECAST AREA BY 06Z. LATEST HRRR RUN IS EVEN
FURTHER WEST WITH INITIAL DEVELOPMENT IN SOUTHERN IOWA...SO HAVE
RAISED POPS A BIT FURTHER WEST. THERE IS A SLIGHT RISK OF SEVERE
WEATHER...WITH THE MAIN THREATS BEING LARGE HAIL AND DAMAGING
WINDS. AS FOR TEMPS...TO REMAIN RATHER MILD WITH LOWS IN THE LOW
TO MID 70S OVERNIGHT.
BYRD
.LONG TERM...(WEDNESDAY THROUGH NEXT TUESDAY)
ISSUED AT 344 PM CDT TUE JUN 25 2013
COMPLEX SCENARIO ON TAP FOR WEDNESDAY WITH LOTS OF UNCERTAINTY TO
SPECIFIC FORECAST DETAILS. THE MAIN COMPLICATING FACTOR IS THE
OVERNIGHT MCS EXPECTED TO IMPACT WESTERN IL AND PORTIONS OF ERN MO
AND WHERE IT WILL BE LOCATED AT DAYBREAK. A CONSENSUS OF MODEL
SOLUTIONS HAVE THE DECAYING MCS IN CENTERED THRU IL AT DAYBREAK WITH
THE TRAILING FLANK OR BOUNDARY LOCATED ALONG THE MS RIVER IN ERN MO.
THE VEERED NATURE OF THE TROPOSPHERIC WINDS AND WLY LLJ WOULD
SUGGEST THIS SYSTEM SHOULD CONTINUE TO MOVE SEWD IN A DECAYING STATE
THROUGH THE MORNING WITH POTENTIAL FOR SOME STORMS ON THE TRAILING
BOUNDARY. STRONG HEATING SHOULD COMMENCE DURING THE DAY WITHIN THE
WARM SECTOR AHEAD OF THE ENCROACHING COLD FRONT...AS WELL AS WEST
OR SOUTHWEST OF ANY REMNANT BOUNDARIES. THE HEATING WILL BE MORE
LIMITED WITH EASTWARD EXTENT DUE TO RESIDUAL CLOUDINESS FROM THE
MORNING...BUT THE WARM SECTOR IS EXPECTED TO BECOME VERY UNSTABLE
AND WEAKLY CAPPED WITH SBCAPE AOA 4000 J/KG. SCATTERED THUNDERSTORMS
ARE EXPECTED TO REDEVELOP IN THE AFTERNOON WITHIN THE CONFLUENT ZONE
AHEAD OF THE COLD FRONT AND WITH ANY RESIDUAL BOUNDARIES...PRIMARILY
FROM EAST CENTRAL/SE MO INTO SOUTH CENTRAL AND SW IL. DEEP LAYER
SHEAR OF 30-40 KTS AND THE AMOUNT OF INSTABILITY WOULD FAVOR
SUPERCELL AND MULTICELL MODES. THE MORNING CONVECTION AND/OR
RESIDUAL CLOUDS PRESENT SOME PROBLEMS WITH RESPECT TO THE
MAGNITUDE OF HEAT. I HAVE COOLED TEMPS SLIGHTLY FROM ST LOUIS
EASTWARD AND THIS IS HIGHLY DEPENDENT ON MORNING CLOUDS. GIVEN THE
UNCERTAINTIES I HAVE DEFER ED ON ANY HEAT ADVISORIES WITH HEAT
INDICES FORECAST IN THE 100-105 RANGE. STORMS SHOULD BE CLOSE TO
EXITING THE CWA OR WILL HAVE EXITED THE CWA BY 00Z THURSDAY.
EVEN IN THE WAKE OF THE INITIAL COLD FRONT/BOUNDARY...THURSDAY LOOKS
LIKE ANOTHER SEASONABLY HOT DAY. IN FACT...IT IS NOT TOTALLY OUT OF
THE QUESTION IT COULD BE HOTTER THAN WEDNESDAY BUT WITH LESSER
HUMIDITY. THE ANTICIPATED NORTHWEST FLOW SHORTWAVE AND SECONDARY
COLD FRONT WILL MOVE THROUGH THE AREA LATE THURSDAY NIGHT INTO EARLY
FRIDAY WITH A PROMINENT WSW LLJ AHEAD OF IT. THIS SHOULD FUEL
ANOTHER MCS WHICH WILL IMPACT PORTIONS OF THE CWA. THE MODELS
DIVERGE ON THE MCS TRACK WITH THE GREATEST PROBABILITY ATTM
APPEARING TO BE THROUGH CENTRAL MO. MUCH COOLER AIR WILL THEN
SPREAD INTO THE AREA IN THE WAKE OF THE FRONT FOR FRIDAY AND SET
THE STAGE FOR A PROLONGED PERIOD OF BELOW AVERAGE TEMPERATURES
INTO THE EXTENDED RANGES.
THE EXTENDED RANGES WILL FEATURE AN AMPLIFIED BLOCKY UPPER AIR REGIME
FROM THE ERN PACIFIC ACROSS THE CONUS INTO THE WRN ATLANTIC...WITH A
STRONG UPPER HIGH/RIDGE CENTERED IN THE WRN U.S. AND DEEP TROF IN
THE ERN U.S. A SERIES OF SHORT WAVES WILL DROP SSEWD DOWN THE
BACKSIDE OF THE UPPER TROF AND IMPACT THE AREA ON SUNDAY AND TUESDAY
REINFORCING THE "COOLER" AIR AND BRINGING A CHANCE OF SHOWERS AND
THUNDERSTORMS.
GLASS
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 647 PM CDT TUE JUN 25 2013
MAIN CONCERNS THE NEXT 24-30 HOURS WILL BE WHERE AND WHEN
THUNDERSTORMS WILL OCCUR. LINE OF THUNDERSTORMS CURRENTLY OVER
CENTRAL ILLINOIS WILL MOVE SOUTHEAST AND MAY AFFECT SOME OF THE
SMALLER AIRPORTS OVER SOUTH CENTRAL ILLINOIS. ADDITIONAL
THUNDERSTORMS ARE EXPECTED TO DEVELOP LATE THIS EVENING/OVERNIGHT
OVER IOWA...THOUGH IT IS NOT YET CLEAR WHICH WAY THEY WILL MOVE.
CURRENT THINKING IS THAT THEY WILL MOVE SOUTHEAST WHICH WILL
LIKELY BRING THEM ACROSS KUIN BETWEEN 08-11Z. IF THEY MOVE MORE
SOUTHWARD THAT EXPECTED...THEN THEY COULD AFFECT THE ST. LOUIS
METRO TAF SITES TOWARD 12Z. SOME OF THE STRONGER STORMS WILL HAVE
THE POTENTIAL TO PRODUCE WIND GUSTS IN EXCESS OF 35KTS...SOME
SMALL HAIL AND BRIEF MVFR/IFR CONDITIONS. ADDITIONAL THUNDERSTORMS
WILL DEVELOP OVER SOUTHEAST MISSOURI INTO SOUTHERN ILLINOIS LATE
MORNING OR AFTERNOON ON WEDNESDAY WITH THE BEST CHANCE STAYING
SOUTH AND EAST OF THE ST. LOUIS METRO TAF SITES. THESE STORMS WILL
HAVE THE POTENTIAL TO BE SEVERE. A COLD FRONT WILL MOVE SOUTHEAST
ACROSS THE AREA ON WEDNESDAY AFTERNOON CAUSING WINDS TO SLOWLY
VEER FROM SOUTH TO NORTHWEST THROUGH THE DAY.
SPECIFICS FOR KSTL...EXPECT MAINLY A DRY AND VFR FORECAST WITH TWO
POSSIBLE EXCEPTIONS. COMPLEX OF THUNDERSTORMS COULD MOVE A BIT
FARTHER SOUTH THAN EXPECTED WHICH COULD REACH THE TERMINAL TOWARD
12Z. ADDITIONAL THUNDERSTORMS ARE EXPECTED TO DEVELOP NEAR THE
TERMINAL AROUND 16Z...HOWEVER STORMS ARE EXPECTED TO STAY JUST
EAST AND SOUTH OF THE TERMINAL.
BRITT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
412 PM CDT Mon Jun 24 2013
.SHORT TERM...(This Evening through Tuesday Night)
Issued at 355 PM CDT MON JUN 24 2013
Main concern will be with potential for convection again tonight and
then increasing heat conditions Tuesday. Latest HRRR model shows shortwave
trough in synoptic flow to hold together as it moves into eastern
Kansas. Dynamics are fairly weak as this is just a ripple in the
nearly zonal flow over the region. However...there is some modest
instability and potential for a decent LLJ late tonight....so another
nocturnal MCS could move through...especially in northern zones where
mid level lapse rates favor better instability.
On Tuesday...there still is a chance in the afternoon in the northern
zones for some convection to fire as yet another very weak short wave
trough moves through. Also of concern is what might be left over in
terms of outflow boundaries from any activity tonight.
Therefore...will keep a chance in the northern zones for tomorrow.
Meanwhile the thermal ridge begins to build to the west with 850mb
temperatures into the middle and upper 20s deg C in western and
central kansas. As this thermal ridge moves towards the area...we
will see heat indices begin to edge up to low 100s. Will not issue
advisory for Tuesday but have mentioned it in the hazardous weather
outlook.
Tuesday night...yet another chance for some nocturnal MCS activity
mainly in the northeastern zones as the thermal ridge axis moves over
the western areas and should limit convection there.
.LONG TERM...(Wednesday through Monday)
Issued at 355 PM CDT MON JUN 24 2013
Beginning in the middle of the work week, the flattened zonal flow
across the nation will begin to amplify as the prevailing westerlies
begin to buckle across the U.S.A./Canadian border. The buckling in
the flow will be lead by a weak shortwave Wednesday, with our region
quickly finding itself in the the northwest flow as the ridge axis
of the amplifying ridge pops up to to our west. However, as the
weekend arrives the trough across the Great Lakes will gather some
energy, expanding enough to possibly but much of our forecast area
on the cool side of the still prevailing northwest flow.
The pattern for the week will dictate hot and humid conditions
through the middle of the work week, with Wednesday and Thursday
being particularly muggy and troublesome. Dew points will be
critical mid-week on determining the need for a heat advisory as
heat indices will be ranging in the low 100s. Currently, forecast
numbers are coming up just shy of criteria, though this currently
looks due to the fact that afternoon dew points will likely mix out
a little as the hot air advecting in aloft from the southwest will
also be a bit dry.
By Friday...temperatures are expected to back off a little from the
hot and humid readings of the previous few days as the trough over
the Great Lakes begins to dominate the eastern CONUS. Readings for
Friday will still reach in the 90s, but the humidity wont be as bad;
and for the weekend temperatures should range through the 80s.
As for precipitation, only true potential for more than isolated
storms looks to be focused on Thursday night into Friday morning as
the edge of the Great Lakes trough begins pushing back to the
southwest. Have kept POPs in the chance category owing to the
vagaries of forecast timing in a northwest flow.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday Afternoon)
Issued at 1221 PM CDT MON JUN 24 2013
An outflow boundary has moved through STJ and MCI temporarily
shifting winds to the NW however winds should back to the south by
19Z. Thunderstorms will be possible over STJ through 19Z with no
cig/vis restrictions. These storms will skirt MCI and there may be a
bit of development along the outflow boundary continuing the chance
for a thunderstorm at MCI, thusly have left VCTS in the MCI TAF
through 19Z. MKC should remain dry. Beyond the 19Z period, conds
should remain VFR at the terminals with gusty winds out of the south
through tonight. Gusts will diminish overnight but winds will remain
out of the south between 10-15kts. Winds will become gusty again by
mid morning tomorrow with sustained winds between 15-20kts and gusts
25-30kts.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...Adolphson/73
LONG TERM...Cutter
AVIATION...73
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
957 PM MDT Tue Jun 25 2013
.UPDATE...
Occasional lightning strikes accompanied a band of showers/weak
thunderstorms that moved through central Montana this evening, but
instability has now weakened...thus no thunder expected overnight. A
few showers will affect parts of central and southwest Montana
through the overnight period. Although, the better chances for
showers will be over the higher terrain of southwest Montana,
especially after 06z/Wed. The NAM depicts a plume of high mid-
level relative humidity values moving into this region between 06z
and 12z/Wed which will likely coincide with the best chance for
scattered showers. Otherwise, expect quiet conditions overnight
with lows in the 50s and 40s for most areas. Uttech
&&
.AVIATION...
Updated 0354Z.
A weak upper level disturbance is keeping the airmass unsettled with
scattered showers. The airmass is quite dry and widespread low
clouds are not expected. Brisk west winds will continue Wednesday
and afternoon gusts should be expected across the region. VFR
conditions will prevail through the next 24 hours.
&&
.PREV DISCUSSION...
/ISSUED 528 PM MDT Tue Jun 25 2013/
Tonight through Thursday...Southwest flow aloft continues to bring
moisture and instability to the area. Convective activity is slow
to develop this afternoon but a large plume of moisture is now
moving into western Montana with scattered showers and
thunderstorms developing. RUC analysis continues to show
precipitation developing over the area this evening and
development will be aided by a jet streak moving across the area.
Have painted low pops across the county warning area until
midnight. Any thunderstorms that develop will likely be high based
with gusty winds being the main threat. Convective activity should
generally end by midnight. Heights begin to rise Wednesday though
isolated showers are possible in a swath across central Montana
Wednesday morning due to the proximity of the jet streak. Heights
continue to rise Wednesday afternoon through Thursday resulting
in dry and warmer conditions. The strong westerly flow aloft
Wednesday, combined with warmer temperatures, will allow the
atmosphere to effectively mix down and gusty winds will result
during the afternoon. Temperatures will be near seasonal averages
Wednesday but will warm through the remainder of the week. Emanuel
Thursday night through Tuesday...Medium range models remain in
good agreement for the first few days of the forecast period. An
upper level ridge over the western U.S. will strengthen over the
northern Rockies for much warmer temperatures for Friday and
Saturday. Model solutions diverge Saturday night as the GFS bring
shortwave energy and an upper level jet through the northern
Rockies for a slight chance of thunderstorms while the ECMWF keeps
a dry and stable airmass in place. The upper wave depicted in the
GFS will continue to affect central Montana through Sunday evening
but the models come back into agreement by Monday as the ridge
axis regresses into the Pacific northwest and puts Montana under a
north to northwest flow aloft with unsettled but continued warm
conditions into Tuesday. mpj
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 52 77 53 82 / 30 20 10 0
CTB 49 74 49 79 / 20 10 10 0
HLN 53 77 53 83 / 30 10 10 0
BZN 50 80 48 86 / 30 10 10 0
WEY 40 72 39 80 / 30 20 10 0
DLN 48 77 48 84 / 40 10 10 0
HVR 54 81 54 84 / 30 10 10 0
LWT 50 76 50 80 / 30 10 10 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
weather.gov/greatfalls
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
934 PM MDT Tue Jun 25 2013
.UPDATE...
Occasional lightning strikes accompanied a band of showers/weak
thunderstorms that moved through central Montana this evening, but
instability has now weakened...thus no thunder expected overnight. A
few showers will affect parts of central and southwest Montana
through the overnight period. Although, the better chances for
showers will be over the higher terrain of southwest Montana,
especially after 06z/Wed. The NAM depicts a plume of high mid-
level relative humidity values moving into this region between 06z
and 12z/Wed which will likely coincide with the best chance for
scattered showers. Otherwise, expect quiet conditions overnight
with lows in the 50s and 40s for most areas. Uttech
&&
.AVIATION...
Updated 2326Z.
A weak upper level disturbance will cross the Rockies this evening
and bring scattered showers and a thunderstorm or two across central
Montana. The airmass is quite dry and widespread low clouds are not
expected. Brisk west winds will continue Wednesday and strong
afternoon gusts should be expected across the region. VFR conditions
will prevail through the next 24 hours.
&&
.PREV DISCUSSION...
/ISSUED 528 PM MDT Tue Jun 25 2013/
Tonight through Thursday...Southwest flow aloft continues to bring
moisture and instability to the area. Convective activity is slow
to develop this afternoon but a large plume of moisture is now
moving into western Montana with scattered showers and
thunderstorms developing. RUC analysis continues to show
precipitation developing over the area this evening and
development will be aided by a jet streak moving across the area.
Have painted low pops across the county warning area until
midnight. Any thunderstorms that develop will likely be high based
with gusty winds being the main threat. Convective activity should
generally end by midnight. Heights begin to rise Wednesday though
isolated showers are possible in a swath across central Montana
Wednesday morning due to the proximity of the jet streak. Heights
continue to rise Wednesday afternoon through Thursday resulting
in dry and warmer conditions. The strong westerly flow aloft
Wednesday, combined with warmer temperatures, will allow the
atmosphere to effectively mix down and gusty winds will result
during the afternoon. Temperatures will be near seasonal averages
Wednesday but will warm through the remainder of the week. Emanuel
Thursday night through Tuesday...Medium range models remain in
good agreement for the first few days of the forecast period. An
upper level ridge over the western U.S. will strengthen over the
northern Rockies for much warmer temperatures for Friday and
Saturday. Model solutions diverge Saturday night as the GFS bring
shortwave energy and an upper level jet through the northern
Rockies for a slight chance of thunderstorms while the ECMWF keeps
a dry and stable airmass in place. The upper wave depicted in the
GFS will continue to affect central Montana through Sunday evening
but the models come back into agreement by Monday as the ridge
axis regresses into the Pacific northwest and puts Montana under a
north to northwest flow aloft with unsettled but continued warm
conditions into Tuesday. mpj
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 52 77 53 82 / 30 20 10 0
CTB 49 74 49 79 / 20 10 10 0
HLN 53 77 53 83 / 30 10 10 0
BZN 50 80 48 86 / 30 10 10 0
WEY 40 72 39 80 / 30 20 10 0
DLN 48 77 48 84 / 40 10 10 0
HVR 54 81 54 84 / 30 10 10 0
LWT 50 76 50 80 / 30 10 10 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
weather.gov/greatfalls
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
528 PM MDT Tue Jun 25 2013
.DISCUSSION...
Tonight through Thursday...Southwest flow aloft continues to bring
moisture and instability to the area. Convective activity is slow
to develop this afternoon but a large plume of moisture is now
moving into western Montana with scattered showers and
thunderstorms developing. RUC analysis continues to show
precipitation developing over the area this evening and
development will be aided by a jet streak moving across the area.
Have painted low pops across the county warning area until
midnight. Any thunderstorms that develop will likely be high based
with gusty winds being the main threat. Convective activity should
generally end by midnight. Heights begin to rise Wednesday though
isolated showers are possible in a swath across central Montana
Wednesday morning due to the proximity of the jet streak. Heights
continue to rise Wednesday afternoon through Thursday resulting
in dry and warmer conditions. The strong westerly flow aloft
Wednesday, combined with warmer temperatures, will allow the
atmosphere to effectively mix down and gusty winds will result
during the afternoon. Temperatures will be near seasonal averages
Wednesday but will warm through the remainder of the week. Emanuel
Thursday night through Tuesday...Medium range models remain in
good agreement for the first few days of the forecast period. An
upper level ridge over the western U.S. will strengthen over the
northern Rockies for much warmer temperatures for Friday and
Saturday. Model solutions diverge Saturday night as the GFS bring
shortwave energy and an upper level jet through the northern
Rockies for a slight chance of thunderstorms while the ECMWF keeps
a dry and stable airmass in place. The upper wave depicted in the
GFS will continue to affect central Montana through Sunday evening
but the models come back into agreement by Monday as the ridge
axis regresses into the Pacific northwest and puts Montana under a
north to northwest flow aloft with unsettled but continued warm
conditions into Tuesday. mpj
&&
.AVIATION...
Updated 2326Z.
A weak upper level disturbance will cross the Rockies this evening
and bring scattered showers and a thunderstorm or two across central
Montana. The airmass is quite dry and widespread low clouds are not
expected. Brisk west winds will continue Wednesday and strong
afternoon gusts should be expected across the region. VFR conditions
will prevail through the next 24 hours.
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 52 77 53 82 / 20 20 10 0
CTB 49 74 49 79 / 20 10 10 0
HLN 53 77 53 83 / 20 10 10 0
BZN 50 80 48 86 / 20 10 10 0
WEY 40 72 39 80 / 20 20 10 0
DLN 48 77 48 84 / 30 10 10 0
HVR 54 81 54 84 / 20 10 10 0
LWT 50 76 50 80 / 20 10 10 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
weather.gov/greatfalls
AREA FORECAST DISCUSSION
NWS HASTINGS NE
ISSUED BY NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
527 AM CDT MON JUN 24 2013
.DISCUSSION...
SCATTERED THUNDERSTORMS WILL MOVE THROUGH THE FORECAST AREA THIS
MORNING. A SEVERE WATCH CONTINUES FOR A FEW OF OUR NEBRASKA
COUNTIES UNTIL 6 AM...BUT OVERALL STORMS HAVE WEAKENED AND
EXISTING WATCH WILL PROBABLY BE ALLOWED TO EXPIRE ON SCHEDULE.
THUNDERSTORMS WILL PROBABLY HAVE ENDED ALTOGETHER BY 18Z AS THE
WEAK WAVE CONTINUES TO MOVE NORTHEAST OF THE AREA. ADDITIONAL
THUNDERSTORMS COULD DEVELOP IN OUR WESTERN FORECAST AREA LATE THIS
AFTERNOON AND COULD CONTINUE THROUGH THE EVENING HOURS WITH A
SLIGHT RISK FOR SEVERE STORMS DURING THIS TIME.
BEYOND TODAY AND TONIGHT...A PERIOD OF HOT WEATHER WILL CONTINUE
THROUGH MOST OF THE REMAINDER OF THE WEEK WITH AFTERNOON TEMPS IN
THE MID 90S TO LOWER 100S. THERE IS A WEAK FRONT THAT PUSHES
THROUGH THE AREA TUESDAY AFTERNOON...WHICH PROVIDES ONLY VERY
SLIGHT RELIEF PRIMARILY TO OUR NORTHERN FORECAST AREA. DID NOT
INCLUDE ANY PRECIP CHANCES WITH THE FRONT AS WE MAY BE TOO CAPPED
TO GET ANYTHING TO DEVELOP.
ALSO LEFT REMAINDER OF FORECAST DRY AS THE REGION REMAINS IN A
WEAK RIDGE PATTERN. CONFIDENCE LEVEL IS JUST TOO LOW TO
EFFECTIVELY TIME ANY SUBTLE WAVES THIS FAR OUT.
&&
.PREV DISCUSSION...
SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 317 PM CDT SUN JUN 23 2013
MORNING MAP ANALYSIS INDICATES QUASI ZONAL TO SOUTHWESTERLY MID TO
UPPER LEVEL FLOW OVER THE WESTERN HALF OF THE CONUS...WITH A
LONGWAVE RIDGE OVER THE EAST. A COUPLE OF MID LEVEL SHORT WAVES ARE
ALSO NOTED...WITH ONE EXTENDING FROM THE UPPER MISSISSIPPI VALLEY
INTO THE NORTHERN PLAINS...AND THE OTHER OVER THE SOUTHWESTERN
CONUS. MID TO UPPER LEVEL JET ENERGY EXTENDS FROM THE
WEST/SOUTHWESTERN CONUS...EAST/NORTHEAST INTO THE CENTRAL
PLAINS...AND THEN NORTH INTO SOUTH CENTRAL CANADA BEFORE FLOWING
EAST INTO SOUTHEASTERN CANADA AND PORTIONS OF THE NORTHEASTERN
CONUS. MID TO UPPER LEVEL FLOW OVER OUR AREA MAXES OUT AT AROUND
60KTS BETWEEN 300MB AND 200MB PER 12Z SOUNDING DATA FROM KLBF AND
KOAX. WATER VAPOR IMAGERY ALSO SHOWS THE AFOREMENTIONED MID LEVEL
SHORT WAVES...ALONG WITH A PAIR OF CLOSED MID LEVEL LOWS. ONE SUCH
LOW IS LOCATED OVER EASTERN ALBERTA AND WESTERN SASKATCHEWAN...AND
THE OTHER IS OVER THE PACIFIC JUST OFF THE COAST OF THE NORTHWESTERN
CONUS. AT THE SURFACE AN AREA OF LOW BAROMETRIC PRESSURE EXISTS OVER
SOUTHWESTERN KANSAS...WITH A FRONTAL BOUNDARY EXTENDING
NORTHEAST FROM THE LOW INTO NORTH CENTRAL KANSAS AND
SOUTHEASTERN NEBRASKA. THE LOW LEVEL WIND FIELD ACROSS MUCH OF OUR
CWA REMAINS FROM THE NORTHEAST FOR THE MOST PART...BUT LOCATIONS
ACROSS OUR SOUTHEAST SUCH AS KK82...KK61...AND KHJH ARE ALL
OBSERVING A SURFACE WIND FROM THE SOUTHEAST.
GUIDANCE FROM THE NAM...OPERATIONAL GFS...EC...AND SREF-MEAN
SUGGESTS THE LOW LEVEL BAROCLINIC ZONE WILL PERSIST OVER
SOUTHEASTERN PORTIONS OF OUR CWA THIS EVENING INTO TONIGHT BEFORE
SURGING NORTH DURING THE DAY MONDAY. THERE ARE
INDICATIONS...ESPECIALLY FROM HIGHER RESOLUTION MODELS SUCH AS THE
NAM12...OF VERY SUBTLE MID LEVEL PERTURBATIONS MOVING OVERHEAD
WITHIN THE MEAN FLOW THIS AFTERNOON AND THIS EVENING. CONFIDENCE ON
SUCH A FEATURE PROMOTING PRECIPITATION PRODUCTION ACROSS OUR AREA
THIS AFTERNOON AND EVENING REMAINS VERY LOW HOWEVER AND AS A
RESULT...WILL CONTINUE RELEGATING ANY AFTERNOON AND EVENING POPS TO
OUR SOUTH/SOUTHEASTERN CWA...IN CLOSEST PROXIMITY TO THE
AFOREMENTIONED LOW LEVEL BAROCLINIC ZONE AND RESULTANT AXIS OF
ENHANCED LOW LEVEL CONVERGENCE AND LIFT. AS FOR THE TIMING OF
CONVECTIVE INITIATION THIS AFTERNOON AND EVENING...FORECAST PROXIMITY
SOUNDINGS FROM THE NAM...OPERATIONAL GFS...AND RAP ALL SUGGEST A
HEALTHY CAP PERSISTING THROUGH AT LEAST 00Z. GIVEN THIS...ITS HARD
TO BUY INTO QPF FIELDS FROM THE NAM...OPERATIONAL GFS...EC...AND
SREF-MEAN...WHICH ALL SUGGEST WIDESPREAD PRECIPITATION WILL BE REALIZED ACROSS
PORTIONS OF OUR SOUTHEAST BEFORE 00Z THIS EVENING. HRRR SIMULATED
REFLECTIVITY LOOKS MUCH MORE REASONABLE...SUGGESTING VERY ISOLATED
CONVECTION OCCURRING ACROSS OUR SOUTHEAST TOWARDS 00Z. GIVEN ALL
THIS...CONFIDENCE IS VERY LOW THAT MUCH PRECIPITATION WILL BE
REALIZED ACROSS OUR AREA PRIOR TO 00Z...BUT CANNOT COMPLETELY RULE
OUT SUCH A SOLUTION AND WILL MAINTAIN ~20% POPS ACROSS OUR SOUTHEAST
23-00Z. 00Z AND BEYOND...FORECAST PROXIMITY SOUNDINGS SUGGEST THE CAPPING
INVERSION WILL WEAKEN SOMEWHAT THUS MAKING CONVECTION SOMEWHAT MORE
LIKELY...A SOLUTION SUPPORTED BY QPF FIELDS FROM THE
NAM...OPERATIONAL GFS...EC...AND SREF-MEAN...AS WELL AS SIMULATED
REFLECTIVITY FROM THE HRRR. GIVEN THIS...WILL GO AHEAD WITH SLIGHTLY
HIGHER POPS...~%30...00-06Z ACROSS OUR SOUTHEAST. SHOULD
SURFACE-BASED CONVECTION BE REALIZED THIS AFTERNOON AND/OR
EVENING...THEN SEVERE WEATHER WILL LIKELY RESULT WITH DEEP LAYER
MUCAPE VALUES IN THE 2000-4000J/KG WAITING FOR UPDRAFT PRODUCTION
AND 30-35KTS OF DEEP LAYER BULK SHEAR FOR UPDRAFT ENHANCEMENT.
CERTAINLY LARGE HAIL AND MICROBURST-RELATED WIND GUSTS WILL BE A
THREAT...BUT ENHANCED HORIZONTAL VORTICITY IN THE VICINITY OF THE
LOW LEVEL BAROCLINIC ZONE COULD ALSO PROMOTE ISOLATED TORNADIC
ACTIVITY. WILL CONTINUE SUCH WORDING IN THE HWO AS A RESULT.
HEADING INTO THE OVERNIGHT HOURS TONIGHT...THE AXIS OF A ~45KT 850MB
JET STREAK IS EXPECTED TO DEVELOP ACROSS PORTIONS OF WESTERN AND
CENTRAL KANSAS...WITH THE NOSE OF THIS LOW LEVEL JET MOVING INTO
SOUTHERN PORTIONS OF OUR CWA BETWEEN 06Z AND 12Z. SHOULD DEEP
CONVECTION BE ONGOING ALONG THE LOW LEVEL BAROCLINIC ZONE...THEN
INCREASING LOW LEVEL THERMAL ADVECTION ALONG THE AXIS OF THE LOW
LEVEL JET COULD CERTAINLY HELP INCREASE SPATIAL COVERAGE OF SAID
CONVECTIVE ACTIVITY. ALSO...IN ADDITION TO POSSIBLE THUNDERSTORM
ACTIVITY OVER PORTIONS OF OUR CWA THIS AFTERNOON AND
EVENING...THUNDERSTORMS ALSO REMAIN POSSIBLE OVER THE CENTRAL HIGH
PLAINS. SHOULD HIGH PLAINS CONVECTION DEVELOP THIS AFTERNOON/EVENING
AND MOVE EAST TOWARDS OUR AREA TONIGHT...ADDITIONAL SHOWER AND
THUNDERSTORM ACTIVITY COULD BE REALIZED OVER OUR AREA
TONIGHT...ESPECIALLY OUR WEST. THIS IS A SOLUTION SUPPORTED BY THE
NAM...OPERATIONAL GFS...SREF-MEAN...AND HRRR. GIVEN ALL THIS...WENT
AHEAD WITH RELATIVELY HIGHER POPS ACROSS MUCH OF THE CWA STARTING
AROUND 06Z. SEVERE WEATHER COULD CERTAINLY BE POSSIBLE DURING THE
EARLY PART OF THE OVERNIGHT HOURS AS THE MORE ROBUST CONVECTION FROM
EARLIER IN THE EVENING...SHOULD IT DEVELOP...MAINTAINS ITSELF. THAT
BEING SAID...BARRING THE DEVELOPMENT OF AN MCS ACROSS THE
REGION...CONVECTIVE ACTIVITY SHOULD WANE IN INTENSITY AS POTENTIAL
INSTABILITY DECREASES 06Z ONWARD.
THERE COULD SOME LINGERING SHOWER AND THUNDERSTORM ACTIVITY ACROSS
OUR AREA AROUND SUNRISE MONDAY...BUT OTHERWISE MONDAY DURING THE DAY
IS EXPECTED TO REMAIN DRY FOR THE MOST PART AS THE WARM FRONT SURGES
NORTH AND AN OVERALL LACK IN KINEMATIC FORCING OVERTAKES THE AREA.
AT THIS TIME THE ONLY REAL THREAT FOR PRECIPITATION DURING THE DAY
MONDAY APPEARS AS THOUGH IT WILL RESIDE OVER OUR SOUTHWESTERN CWA
DURING THE LATE AFTERNOON AND EVENING HOURS...WHICH IS WHERE AND
WHEN GUIDANCE SUGGESTS AN ADVANCING LOW LEVEL DRY LINE WILL BULGE EAST.
AN AREA OF LOCALLY ENHANCED CONVERGENCE AND LIFT IN THE VICINITY OF
THIS DRY LINE BULGE...WORKING IN CONCERT WITH DIABATIC HEATING...MAY
BE ENOUGH TO INITIALIZE ISOLATED SHOWER AND THUNDERSTORM DEVELOPMENT
AND AS A RESULT...~20% POPS ARE FORECAST 21Z MONDAY THROUGH 00Z
TUESDAY ACROSS OUR SOUTHWEST. SHOULD THUNDERSTORM ACTIVITY BE REALIZED LATE
MONDAY AFTERNOON AND/OR EVENING...THEN DEEP LAYER MUCAPE VALUES OF
2000-3000J/KG...ALONG WITH DEEP LAYER BULK SHEAR VALUES OF
~30KTS...WILL BE AVAILABLE FOR UPDRAFT PRODUCTION AND ENHANCEMENT.
GIVEN THIS...WILL GO AHEAD AND HIGHLIGHT THE THREAT FOR ISOLATED
SEVERE WEATHER ACROSS OUR SOUTHWEST MONDAY AFTERNOON AND EVENING.
FINALLY...INCREASING SOUTHERLY FLOW WILL LIKELY BE OBSERVED MONDAY
AFTERNOON ONCE THE SURFACE WARM FRONT SURGES NORTH. GUIDANCE
SUGGESTS A SUSTAINED WIND OF ~24KTS...WITH HIGHER GUSTS APPROACHING
35KTS...WILL BE REALIZED PRIMARILY ACROSS NORTH CENTRAL KANSAS. AS A
RESULT...WILL CONTINUE MENTIONING SUCH CONDITIONS IN THE HWO.
LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 317 PM CDT SUN JUN 23 2013
MONDAY NIGHT...A VORT MAX LOCATED OVER THE HIGH PLAINS WILL TRACK
EAST ACROSS THE FORECAST AREA. THUNDERSTORMS THAT INITIALLY FORM
ACROSS THE HIGH PLAINS DURING THE MONDAY AFTERNOON HOURS WILL SLIDE
EAST DURING THE EVENING AND OVERNIGHT HOURS...AND IF THEY HOLD
TOGETHER MAY BRING RAIN TO PORTIONS OF THE FORECAST AREA. IN
ADDITION TO RAIN...SOME OF THESE THUNDERSTORMS MAY BE SEVERE WITH
LARGE HAIL AND DAMAGING WINDS POSSIBLE DURING THE EVENING HOURS.
INSTABILITY IS HIGH AND DEEP LAYER SHEAR IS MORE MODEST BUT
SUFFICIENT FOR SEVERE STORMS. THE LIMITING FACTOR WILL BE THE WARM
MID LEVEL CAP AND THUS CONFIDENCE IN THUNDERSTORM DEVELOPMENT AND
COVERAGE IS STILL FAIRLY LOW WITH SLIGHT POPS. THE 12Z ECMWF AND 12Z
NAM FAVOR OUR WEST AND NORTH FOR STORMS...WHILE THE 12Z GFS
HIGHLIGHTS OUR SOUTHEASTERN ZONES. THE ECMWF AND NAM MAKE MORE SENSE
WITH FAVORING NORTH AND WEST ZONES BASED ON THE EXPECTED UPPER WAVE
LOCATION AND THE INCREASING STRENGTH OF THE CAP AS YOU HEAD SOUTH.
TUESDAY AND WEDNESDAY...THE PATTERN WILL BE FAIRLY ZONAL WITH ALL
OF THE BETTER UPPER FLOW AND SHORT WAVES TRACKING ACROSS THE
NORTHERN TIER STATES. AN UPPER RIDGE WILL SLOWLY BEGIN TO BUILD
ACROSS THE SOUTHWEST CONUS STARTING ON WEDNESDAY. A SFC TROUGH AXIS
WILL TRACK EAST THROUGH OUR FORECAST AREA LATE ON TUESDAY AND TURN
THE WINDS TO NORTHERLY BY WEDNESDAY. HOWEVER...A STRONG CAP SHOULD
RESULT IN DRY CONDITIONS FOR MOST AREAS AND WILL CONTINUE TO CALL
FOR A DRY FORECAST...BUT CAN NOT COMPLETELY RULE OUT AN ISOLATED
THUNDERSTORM...HENCE THE 10 PERCENT POPS. TUESDAY WILL BE SCORCHER
WITH HIGHS WELL INTO THE 90S ACROSS NEBRASKA TO OVER 100 ACROSS MUCH
OF NORTHERN KANSAS. TEMPERATURES WILL FALL A FEW DEGREES WITH THE
NORTH WINDS ON WEDNESDAY...BUT CONTINUE TO EXPECT 90S FOR HIGHS.
THURSDAY THROUGH SUNDAY...THERE IS A SHIFT IN THE UPPER PATTERN AS
AN UPPER RIDGE STRENGTHENS ACROSS THE ROCKIES AND AN UPPER TROUGH
PERSISTS ACROSS THE EASTERN CONUS. THIS WILL RESULT IN NORTHWESTERLY
FLOW ALOFT FOR OUR FORECAST AREA. MOST AREAS WILL BE DRY THROUGHOUT
THIS PERIOD GIVEN A LACK OF FORCING. THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS ON THURSDAY INTO THURSDAY NIGHT...BUT MOST RESENT
MODEL RUNS ARE STARTING TO BACK OFF OF THIS ALREADY RATHER SLIGHT
CHANCE OF PRECIPITATION. ANOTHER WEAK COOL FRONT WILL TRY TO WORK
ITS WAY THROUGH AT SOME POINT THURSDAY NIGHT OR FRIDAY...BUT THURSDAY
SHOULD STILL BE A HOT DAY WITH 90S ACROSS NEBRASKA TO NEAR 100 IN
KANSAS. THE COOLER WEATHER WILL SETTLE IN ON FRIDAY AND SATURDAY
WITH EASTERLY TO NORTHEASTERLY SFC WINDS. THIS COOLER FETCH SHOULD
DROP HIGHS BACK INTO THE LOWER AND MID 90S ON FRIDAY...AND THEN 80S
ACROSS NEBRASKA TO LOWER 90S OVER KANSAS ON SATURDAY. TEMPERATURES
BEGIN TO WARM BACK UP ON SUNDAY WITH EVERYONE BACK IN THE 90S.
OVERALL...TEMPERATURES WILL NOT VARY THAT MUCH AND REMAIN RATHER
TOASTY.
AVIATION...(FOR THE 06Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 115 AM CDT MON JUN 24 2013
GENERALLY VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. CONVECTION
DEVELOPING OFF THE HIGHS PLAINS EARLY TONIGHT WILL SHIFT NEWD AND MAY
IMPACT THE GRI TERMINAL AROUND 9-11Z AND WILL INCLUDE A TEMPO GROUP
FOR THIS. OTHERWISE SOME MVFR CIGS ARE AROUND THE REGION...BUT WE
EXPECT MUCH OF THIS TO LIFT NWD OVERNIGHT BUT SOME MVFR CIGS/VISBY
ARE POSSIBLE IN THE TSRA. OTHERWISE SOUTHERLY WINDS WILL INCREASE
THROUGH THE DAY ON MON.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
ISSUED BY THE NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
115 AM CDT MON JUN 24 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 317 PM CDT SUN JUN 23 2013
MORNING MAP ANALYSIS INDICATES QUASI ZONAL TO SOUTHWESTERLY MID TO
UPPER LEVEL FLOW OVER THE WESTERN HALF OF THE CONUS...WITH A
LONGWAVE RIDGE OVER THE EAST. A COUPLE OF MID LEVEL SHORT WAVES ARE
ALSO NOTED...WITH ONE EXTENDING FROM THE UPPER MISSISSIPPI VALLEY
INTO THE NORTHERN PLAINS...AND THE OTHER OVER THE SOUTHWESTERN
CONUS. MID TO UPPER LEVEL JET ENERGY EXTENDS FROM THE
WEST/SOUTHWESTERN CONUS...EAST/NORTHEAST INTO THE CENTRAL
PLAINS...AND THEN NORTH INTO SOUTH CENTRAL CANADA BEFORE FLOWING
EAST INTO SOUTHEASTERN CANADA AND PORTIONS OF THE NORTHEASTERN
CONUS. MID TO UPPER LEVEL FLOW OVER OUR AREA MAXES OUT AT AROUND
60KTS BETWEEN 300MB AND 200MB PER 12Z SOUNDING DATA FROM KLBF AND
KOAX. WATER VAPOR IMAGERY ALSO SHOWS THE AFOREMENTIONED MID LEVEL
SHORT WAVES...ALONG WITH A PAIR OF CLOSED MID LEVEL LOWS. ONE SUCH
LOW IS LOCATED OVER EASTERN ALBERTA AND WESTERN SASKATCHEWAN...AND
THE OTHER IS OVER THE PACIFIC JUST OFF THE COAST OF THE NORTHWESTERN
CONUS. AT THE SURFACE AN AREA OF LOW BAROMETRIC PRESSURE EXISTS OVER
SOUTHWESTERN KANSAS...WITH A FRONTAL BOUNDARY EXTENDING
NORTHEAST FROM THE LOW INTO NORTH CENTRAL KANSAS AND
SOUTHEASTERN NEBRASKA. THE LOW LEVEL WIND FIELD ACROSS MUCH OF OUR
CWA REMAINS FROM THE NORTHEAST FOR THE MOST PART...BUT LOCATIONS
ACROSS OUR SOUTHEAST SUCH AS KK82...KK61...AND KHJH ARE ALL
OBSERVING A SURFACE WIND FROM THE SOUTHEAST.
GUIDANCE FROM THE NAM...OPERATIONAL GFS...EC...AND SREF-MEAN
SUGGESTS THE LOW LEVEL BAROCLINIC ZONE WILL PERSIST OVER
SOUTHEASTERN PORTIONS OF OUR CWA THIS EVENING INTO TONIGHT BEFORE
SURGING NORTH DURING THE DAY MONDAY. THERE ARE
INDICATIONS...ESPECIALLY FROM HIGHER RESOLUTION MODELS SUCH AS THE
NAM12...OF VERY SUBTLE MID LEVEL PERTURBATIONS MOVING OVERHEAD
WITHIN THE MEAN FLOW THIS AFTERNOON AND THIS EVENING. CONFIDENCE ON
SUCH A FEATURE PROMOTING PRECIPITATION PRODUCTION ACROSS OUR AREA
THIS AFTERNOON AND EVENING REMAINS VERY LOW HOWEVER AND AS A
RESULT...WILL CONTINUE RELEGATING ANY AFTERNOON AND EVENING POPS TO
OUR SOUTH/SOUTHEASTERN CWA...IN CLOSEST PROXIMITY TO THE
AFOREMENTIONED LOW LEVEL BAROCLINIC ZONE AND RESULTANT AXIS OF
ENHANCED LOW LEVEL CONVERGENCE AND LIFT. AS FOR THE TIMING OF
CONVECTIVE INITIATION THIS AFTERNOON AND EVENING...FORECAST PROXIMITY
SOUNDINGS FROM THE NAM...OPERATIONAL GFS...AND RAP ALL SUGGEST A
HEALTHY CAP PERSISTING THROUGH AT LEAST 00Z. GIVEN THIS...ITS HARD
TO BUY INTO QPF FIELDS FROM THE NAM...OPERATIONAL GFS...EC...AND
SREF-MEAN...WHICH ALL SUGGEST WIDESPREAD PRECIPITATION WILL BE REALIZED ACROSS
PORTIONS OF OUR SOUTHEAST BEFORE 00Z THIS EVENING. HRRR SIMULATED
REFLECTIVITY LOOKS MUCH MORE REASONABLE...SUGGESTING VERY ISOLATED
CONVECTION OCCURRING ACROSS OUR SOUTHEAST TOWARDS 00Z. GIVEN ALL
THIS...CONFIDENCE IS VERY LOW THAT MUCH PRECIPITATION WILL BE
REALIZED ACROSS OUR AREA PRIOR TO 00Z...BUT CANNOT COMPLETELY RULE
OUT SUCH A SOLUTION AND WILL MAINTAIN ~20% POPS ACROSS OUR SOUTHEAST
23-00Z. 00Z AND BEYOND...FORECAST PROXIMITY SOUNDINGS SUGGEST THE CAPPING
INVERSION WILL WEAKEN SOMEWHAT THUS MAKING CONVECTION SOMEWHAT MORE
LIKELY...A SOLUTION SUPPORTED BY QPF FIELDS FROM THE
NAM...OPERATIONAL GFS...EC...AND SREF-MEAN...AS WELL AS SIMULATED
REFLECTIVITY FROM THE HRRR. GIVEN THIS...WILL GO AHEAD WITH SLIGHTLY
HIGHER POPS...~%30...00-06Z ACROSS OUR SOUTHEAST. SHOULD
SURFACE-BASED CONVECTION BE REALIZED THIS AFTERNOON AND/OR
EVENING...THEN SEVERE WEATHER WILL LIKELY RESULT WITH DEEP LAYER
MUCAPE VALUES IN THE 2000-4000J/KG WAITING FOR UPDRAFT PRODUCTION
AND 30-35KTS OF DEEP LAYER BULK SHEAR FOR UPDRAFT ENHANCEMENT.
CERTAINLY LARGE HAIL AND MICROBURST-RELATED WIND GUSTS WILL BE A
THREAT...BUT ENHANCED HORIZONTAL VORTICITY IN THE VICINITY OF THE
LOW LEVEL BAROCLINIC ZONE COULD ALSO PROMOTE ISOLATED TORNADIC
ACTIVITY. WILL CONTINUE SUCH WORDING IN THE HWO AS A RESULT.
HEADING INTO THE OVERNIGHT HOURS TONIGHT...THE AXIS OF A ~45KT 850MB
JET STREAK IS EXPECTED TO DEVELOP ACROSS PORTIONS OF WESTERN AND
CENTRAL KANSAS...WITH THE NOSE OF THIS LOW LEVEL JET MOVING INTO
SOUTHERN PORTIONS OF OUR CWA BETWEEN 06Z AND 12Z. SHOULD DEEP
CONVECTION BE ONGOING ALONG THE LOW LEVEL BAROCLINIC ZONE...THEN
INCREASING LOW LEVEL THERMAL ADVECTION ALONG THE AXIS OF THE LOW
LEVEL JET COULD CERTAINLY HELP INCREASE SPATIAL COVERAGE OF SAID
CONVECTIVE ACTIVITY. ALSO...IN ADDITION TO POSSIBLE THUNDERSTORM
ACTIVITY OVER PORTIONS OF OUR CWA THIS AFTERNOON AND
EVENING...THUNDERSTORMS ALSO REMAIN POSSIBLE OVER THE CENTRAL HIGH
PLAINS. SHOULD HIGH PLAINS CONVECTION DEVELOP THIS AFTERNOON/EVENING
AND MOVE EAST TOWARDS OUR AREA TONIGHT...ADDITIONAL SHOWER AND
THUNDERSTORM ACTIVITY COULD BE REALIZED OVER OUR AREA
TONIGHT...ESPECIALLY OUR WEST. THIS IS A SOLUTION SUPPORTED BY THE
NAM...OPERATIONAL GFS...SREF-MEAN...AND HRRR. GIVEN ALL THIS...WENT
AHEAD WITH RELATIVELY HIGHER POPS ACROSS MUCH OF THE CWA STARTING
AROUND 06Z. SEVERE WEATHER COULD CERTAINLY BE POSSIBLE DURING THE
EARLY PART OF THE OVERNIGHT HOURS AS THE MORE ROBUST CONVECTION FROM
EARLIER IN THE EVENING...SHOULD IT DEVELOP...MAINTAINS ITSELF. THAT
BEING SAID...BARRING THE DEVELOPMENT OF AN MCS ACROSS THE
REGION...CONVECTIVE ACTIVITY SHOULD WANE IN INTENSITY AS POTENTIAL
INSTABILITY DECREASES 06Z ONWARD.
THERE COULD SOME LINGERING SHOWER AND THUNDERSTORM ACTIVITY ACROSS
OUR AREA AROUND SUNRISE MONDAY...BUT OTHERWISE MONDAY DURING THE DAY
IS EXPECTED TO REMAIN DRY FOR THE MOST PART AS THE WARM FRONT SURGES
NORTH AND AN OVERALL LACK IN KINEMATIC FORCING OVERTAKES THE AREA.
AT THIS TIME THE ONLY REAL THREAT FOR PRECIPITATION DURING THE DAY
MONDAY APPEARS AS THOUGH IT WILL RESIDE OVER OUR SOUTHWESTERN CWA
DURING THE LATE AFTERNOON AND EVENING HOURS...WHICH IS WHERE AND
WHEN GUIDANCE SUGGESTS AN ADVANCING LOW LEVEL DRY LINE WILL BULGE EAST.
AN AREA OF LOCALLY ENHANCED CONVERGENCE AND LIFT IN THE VICINITY OF
THIS DRY LINE BULGE...WORKING IN CONCERT WITH DIABATIC HEATING...MAY
BE ENOUGH TO INITIALIZE ISOLATED SHOWER AND THUNDERSTORM DEVELOPMENT
AND AS A RESULT...~20% POPS ARE FORECAST 21Z MONDAY THROUGH 00Z
TUESDAY ACROSS OUR SOUTHWEST. SHOULD THUNDERSTORM ACTIVITY BE REALIZED LATE
MONDAY AFTERNOON AND/OR EVENING...THEN DEEP LAYER MUCAPE VALUES OF
2000-3000J/KG...ALONG WITH DEEP LAYER BULK SHEAR VALUES OF
~30KTS...WILL BE AVAILABLE FOR UPDRAFT PRODUCTION AND ENHANCEMENT.
GIVEN THIS...WILL GO AHEAD AND HIGHLIGHT THE THREAT FOR ISOLATED
SEVERE WEATHER ACROSS OUR SOUTHWEST MONDAY AFTERNOON AND EVENING.
FINALLY...INCREASING SOUTHERLY FLOW WILL LIKELY BE OBSERVED MONDAY
AFTERNOON ONCE THE SURFACE WARM FRONT SURGES NORTH. GUIDANCE
SUGGESTS A SUSTAINED WIND OF ~24KTS...WITH HIGHER GUSTS APPROACHING
35KTS...WILL BE REALIZED PRIMARILY ACROSS NORTH CENTRAL KANSAS. AS A
RESULT...WILL CONTINUE MENTIONING SUCH CONDITIONS IN THE HWO.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 317 PM CDT SUN JUN 23 2013
MONDAY NIGHT...A VORT MAX LOCATED OVER THE HIGH PLAINS WILL TRACK
EAST ACROSS THE FORECAST AREA. THUNDERSTORMS THAT INITIALLY FORM
ACROSS THE HIGH PLAINS DURING THE MONDAY AFTERNOON HOURS WILL SLIDE
EAST DURING THE EVENING AND OVERNIGHT HOURS...AND IF THEY HOLD
TOGETHER MAY BRING RAIN TO PORTIONS OF THE FORECAST AREA. IN
ADDITION TO RAIN...SOME OF THESE THUNDERSTORMS MAY BE SEVERE WITH
LARGE HAIL AND DAMAGING WINDS POSSIBLE DURING THE EVENING HOURS.
INSTABILITY IS HIGH AND DEEP LAYER SHEAR IS MORE MODEST BUT
SUFFICIENT FOR SEVERE STORMS. THE LIMITING FACTOR WILL BE THE WARM
MID LEVEL CAP AND THUS CONFIDENCE IN THUNDERSTORM DEVELOPMENT AND
COVERAGE IS STILL FAIRLY LOW WITH SLIGHT POPS. THE 12Z ECMWF AND 12Z
NAM FAVOR OUR WEST AND NORTH FOR STORMS...WHILE THE 12Z GFS
HIGHLIGHTS OUR SOUTHEASTERN ZONES. THE ECMWF AND NAM MAKE MORE SENSE
WITH FAVORING NORTH AND WEST ZONES BASED ON THE EXPECTED UPPER WAVE
LOCATION AND THE INCREASING STRENGTH OF THE CAP AS YOU HEAD SOUTH.
TUESDAY AND WEDNESDAY...THE PATTERN WILL BE FAIRLY ZONAL WITH ALL
OF THE BETTER UPPER FLOW AND SHORT WAVES TRACKING ACROSS THE
NORTHERN TIER STATES. AN UPPER RIDGE WILL SLOWLY BEGIN TO BUILD
ACROSS THE SOUTHWEST CONUS STARTING ON WEDNESDAY. A SFC TROUGH AXIS
WILL TRACK EAST THROUGH OUR FORECAST AREA LATE ON TUESDAY AND TURN
THE WINDS TO NORTHERLY BY WEDNESDAY. HOWEVER...A STRONG CAP SHOULD
RESULT IN DRY CONDITIONS FOR MOST AREAS AND WILL CONTINUE TO CALL
FOR A DRY FORECAST...BUT CAN NOT COMPLETELY RULE OUT AN ISOLATED
THUNDERSTORM...HENCE THE 10 PERCENT POPS. TUESDAY WILL BE SCORCHER
WITH HIGHS WELL INTO THE 90S ACROSS NEBRASKA TO OVER 100 ACROSS MUCH
OF NORTHERN KANSAS. TEMPERATURES WILL FALL A FEW DEGREES WITH THE
NORTH WINDS ON WEDNESDAY...BUT CONTINUE TO EXPECT 90S FOR HIGHS.
THURSDAY THROUGH SUNDAY...THERE IS A SHIFT IN THE UPPER PATTERN AS
AN UPPER RIDGE STRENGTHENS ACROSS THE ROCKIES AND AN UPPER TROUGH
PERSISTS ACROSS THE EASTERN CONUS. THIS WILL RESULT IN NORTHWESTERLY
FLOW ALOFT FOR OUR FORECAST AREA. MOST AREAS WILL BE DRY THROUGHOUT
THIS PERIOD GIVEN A LACK OF FORCING. THERE IS A SLIGHT CHANCE OF
THUNDERSTORMS ON THURSDAY INTO THURSDAY NIGHT...BUT MOST RESENT
MODEL RUNS ARE STARTING TO BACK OFF OF THIS ALREADY RATHER SLIGHT
CHANCE OF PRECIPITATION. ANOTHER WEAK COOL FRONT WILL TRY TO WORK
ITS WAY THROUGH AT SOME POINT THURSDAY NIGHT OR FRIDAY...BUT THURSDAY
SHOULD STILL BE A HOT DAY WITH 90S ACROSS NEBRASKA TO NEAR 100 IN
KANSAS. THE COOLER WEATHER WILL SETTLE IN ON FRIDAY AND SATURDAY
WITH EASTERLY TO NORTHEASTERLY SFC WINDS. THIS COOLER FETCH SHOULD
DROP HIGHS BACK INTO THE LOWER AND MID 90S ON FRIDAY...AND THEN 80S
ACROSS NEBRASKA TO LOWER 90S OVER KANSAS ON SATURDAY. TEMPERATURES
BEGIN TO WARM BACK UP ON SUNDAY WITH EVERYONE BACK IN THE 90S.
OVERALL...TEMPERATURES WILL NOT VARY THAT MUCH AND REMAIN RATHER
TOASTY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 115 AM CDT MON JUN 24 2013
GENERALLY VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. CONVECTION
DEVELOPING OFF THE HIGHS PLAINS EARLY TONIGHT WILL SHIFT NEWD AND MAY
IMPACT THE GRI TERMINAL AROUND 9-11Z AND WILL INCLUDE A TEMPO GROUP
FOR THIS. OTHERWISE SOME MVFR CIGS ARE AROUND THE REGION...BUT WE
EXPECT MUCH OF THIS TO LIFT NWD OVERNIGHT BUT SOME MVFR CIGS/VISBY
ARE POSSIBLE IN THE TSRA. OTHERWISE SOUTHERLY WINDS WILL INCREASE
THROUGH THE DAY ON MON.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...
LONG TERM...
AVIATION...BOUSTEAD
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1019 PM EDT TUE JUN 25 2013
.SYNOPSIS...
WEAK DISTURBANCES WILL CROSS THE AREA THROUGH WEDNESDAY...WITH
SCATTERED SHOWERS OR THUNDERSTORMS ANTICIPATED...BUT ALSO
SIGNIFICANT PERIODS OF RAIN-FREE WEATHER. BY THURSDAY...A STRONGER
SYSTEM WILL APPROACH...AND IS EXPECTED TO BRING MORE PERSISTENT
SHOWERS AND THUNDERSTORMS. MUGGY AND SEASONABLY WARM CONDITIONS
WILL CONTINUE...WITH HIGHS MOSTLY IN THE 80S THROUGH THE END OF
THE WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
10 UPDATE...CONV CONTS TO FIRE ACROSS CNTRL PA AHD OF A PARADE OF
WEAK SHRT WVS IN THE WLY FLOW. HRRR SEMS TO HAVE THE BEST HANDLE
ON THE CONV AND CONTS THE PCPN...WITH SLOW WEAKENING OVRNGT. WILL
CONT WITH CHANCE POPS OVER THE SRN ZONES AND SLGT CHANCE ELSEWHERE
FOR ROGUE SHWRS FIRING FURTHER NORTH. PLENTY OF CLDS UPSTREAM AS
WELL SO FOG SHD NOT BE A BIG CNCRN OVERNGT. PRVS DISC BLO.
345 PM UPDATE... ONE BATCH OF CONVECTION IS EXITING OUR ERN ZNS
LATE THIS AFTN...ASSOCD WITH A DEPARTING MCV. CNY/NE PA SHOULD
EXPERIENCE A RELATIVE LULL/RAIN-FREE PD THROUGH 22-00Z.
BY EARLY EVE...AN ORGANIZING BAND OF SHRA/TSRA...FROM SRN ONT ACRS
LK ERIE AND ERN OH ATTM...IS EXPECTED TO COME EWD...AND COULD WELL
IMPACT SRN PTNS OF THE FA. THERE IS SOME UNCERTAINTY REGARDING LINGERING
AMTS OF INSTAB BY THIS TIME...BUT IT WILL LIKELY STILL BE
UNSTABLE ENOUGH FOR AT LEAST SCTD COVERAGE. GIVEN INCREASED VERT
SHEAR THIS EVE (0-3 KM VALUES NEAR 40 KT)...STORMS WILL HAVE TO BE
WATCHED FOR WIND POTENTIAL...SHOULD THEY ORGANIZE INTO LINEAR
FEATURES.
LTR TNT...WE SHOULD SEE A SHORT BREAK IN PCPN ONCE AGN. SINCE
THERE IS PLENTY OF CLOUD DEBRIS UPSTREAM TO THE W ATTM...WE
ANTICIPATE PTLY TO MOSTLY CLDY SKIES MUCH OF THE NGT...AND THIS
CLOUD COVER SHOULD CUT DOWN ON THE RADIATIONAL COOLING/FOG
POTENTIAL.
TWDS DAYBREAK...ANOTHER INCOMING UPR-LVL WAVE COULD BRING A ROUND
OF SHWRS...AND WE`VE THUS BROUGHT CHC/SCTD POPS IN FROM THE W
AFTER 08-09Z.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
4 PM UPDATE... AN UPR-LVL WAVE WILL CROSS NY/PA WED...MAINLY IN
THE AM HRS (BEFORE 18Z). SUCH EARLY TIMING WOULD SUGGEST NON-SVR
STORMS...WITH PERHAPS INSUFFICIENT TIME FOR ADEQUATE
DESTABILIZATION...BEFORE THE WV BEGINS TO DEPART...WITH
DIMINISHING ACTIVITY IN THE AFTN. FOR NOW...WE GRADUALLY TAPER
CHC/SCTD POPS BACK...FROM NW TO SE...AFTER 18Z.
THE NEXT STGR UPR-LVL SYSTEM IS PROGGED TO DIG INTO THE ERN LKS/OH
VLY RGN LATE WED NGT/THU. AT THIS EARLY JUNCTURE...MOST OF WED NGT
SHOULD FEATURE EITHER NO PCPN...OR JUST HIT AND MISS SHWR ACTIVITY.
HOWEVER...LATE AT NGT INTO THU AM...OUR CHCS FOR SHWRS/THUNDER
SHOULD INCREASE...AS UPR-LVL JET FORCING AND MOISTURE ADVECTION
IMPROVE.
THERE REMAIN SUBTLE MODEL POSITIONING DIFFS ON THU...BUT THE
MAIN SYNOPTIC IDEA IS FOR A FAIRLY AMPLIFIED UPR-LVL WAVE TO
SLOWLY LIFT FROM THE OH VLY INTO THE NERN STATES...WITH A PRETTY
WELL DEFINED SFC LOW FOR THIS TIME OF YEAR...TRANSLATING NEWD
ACRS PA AND NY STATE. THUS...WE`VE BUMPED POPS INTO THE LIKELY/NUMEROUS
RANGES. DEPENDING ON SPECIFICALLY WHERE THE SFC LOW TRACKS...THE
WARM SECTOR DVLPS...AND THE EXTENT OF CLOUD COVER/SFC
HEATING...THERE IS POTENTIAL FOR SVR STORMS (GOOD LOW-LVL DIR
SHEAR AND VERT SPEED SHEAR). WE`LL SIMPLY HAVE TO SEE HOW THINGS
EVOLVE OVER THE NEXT COUPLE OF DAYS. FOR NOW...WE`LL CONTINUE TO
HIGHLIGHT THIS POTENTIAL IN THE HWO.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
VERY FEW CHANGES MADE TO THE EXTENDED TIME FRAME WITH THE
EXCEPTION OF INCREASING POPS INTO THE LIKELY CATEGORY THIS WEEKEND
INTO EARLY NEXT WEEK AS MODEL TRENDS CONTINUE TO FAVOR A VERY WET
SCENARIO IN COMING DAYS. MAIN CULPRITS CONTINUE TO BE DEVELOPING
RIDGING ACROSS BOTH THE NORTHERN ATLANTIC AND INTERMOUNTAIN
WEST...WITH ALL MODELS ALSO SHOWING A DIGGING UPPER-LEVEL TROUGH
EXTENDING FROM THE CENTRAL GREAT LAKES SOUTH INTO THE LWR MISS RVR
VLY. CONCERNS CONTINUE TO INCREASE THAT TROPICAL CONNECTIONS WILL
BECOME FIRMLY ESTABLISHED BY THE WEEKEND AS THE GULF OF MEXICO AND
WESTERN ATLANTIC REMAIN WIDE-OPEN FOR STRONG LOW-LEVEL MOISTURE
TRANSPORT NORTH ALONG THE ATLANTIC SEABOARD. AS A RESULT...FELT
COMPELLED TO INCREASE POPS ACCORDINGLY...WHICH AGREES WELL WITH
LATEST 12Z WPC GUIDANCE. TRENDS WILL HAVE TO BE MONITORED IN
COMING DAYS...BUT THE DEVELOPING SYNOPTIC PATTERN LOOKS EERILY
SIMILAR TO PATTERNS RESPONSIBLE FOR PAST LARGE-SCALE EAST COAST
FLOOD EVENTS. STAY TUNED!
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
CONVECTION CONTINUES THIS EVENING BUT IT IS EXPECTED TO REMAIN
AWAY FROM MOST OF OUR TERMINALS THROUGH EARLY TONIGHT. THE LONE EXCEPTION
MAY BE KAVP. AN AREA OF SCT. THUNDERSETORMS CONTINUES AROUND THE
TERMINAL NOW...WITH A STEADIER AREA OF RAIN OVER NW PA. WITH
CONVECTION CLOSE BY INCLUDED A TEMPO GROUP TO COVER -TSRA BETWEEN
01Z AND 02Z. BETWEEN 02Z AND 05Z MORE OF A GENERAL RAIN IS
POSSIBLE WITH MVFR VSBYS THE MOST LIKELY AVIATION IMPACT.
ELSEWHERE VFR OVERNIGHT. ENOUGH CLOUDS FROM THUNDERSTORMS TO OUR
WEST SHOULD PREVENT FOG FORMATION OVERNIGHT.
A DISTURBANCE WEDNESDAY BETWEEN 15Z AND 20Z WILL BRING ANOTHER
ROUND OF SHOWERS AND POSSIBLY THUNDER TO THE TERMINALS. CONFIDENCE
HIGH ENOUGH FOR A TEMPO GROUP OF MVFR VSBYS IN SHOWERS DURING THIS
TIME. THUNDER IS POSSIBLE BUT TOO FAR OUT TO INCLUDE AT THE
MOMENT.
OUTLOOK...THU THROUGH SAT...
THU...SHORT DURATION MVFR/IFR POSSIBLE IN DEVELOPING TSRA
ACTIVITY.
FRI...MAINLY VFR. EARLY MORNING MVFR/IFR IN VALLEY FOG.
SAT...MVFR RESTRICTIONS POSSIBLE IN DEVELOPING RA.
SUN...MVFR POSSIBLE IN SHOWERS/STORMS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DGM/MLJ
NEAR TERM...DGM/MLJ
SHORT TERM...MLJ
LONG TERM...CMG
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS BUFFALO NY
759 PM EDT TUE JUN 25 2013
.SYNOPSIS...
UNSETTLED WEATHER WILL CONTINUE RIGHT THROUGH THE UPCOMING
WEEKEND...WITH WARM AND HUMID CONDITIONS GRADUALLY GIVING WAY TO
SOMEWHAT COOLER AND LESS HUMID AIR BY SATURDAY AND SUNDAY AS A
DEEP UPPER LEVEL TROUGH DEVELOPS ACROSS THE GREAT LAKES AND
NORTHEAST.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
RADAR IMAGERY THIS EVENING SHOWING A MATURING MCS TRACKING SOUTHEAST
THROUGH PA. THE NORTHERN EDGE OF THE STRATIFORM RAIN OF THIS FEATURE
WILL CONTINUE TO CROSS THE SOUTHERN TIER THROUGH MID EVENING.
ELSEWHERE SCATTERED THUNDERSTORMS HAVE FORMED FROM WESTERN LAKE
ONTARIO TO THE SAINT LAWRENCE VALLEY ALONG AND JUST AHEAD OF A WEAK
TROUGH NOTED IN SURFACE WIND FIELDS. EXPECT MOST OF THIS ACTIVITY TO
REMAIN OVER LAKE ONTARIO THIS EVENING...ALTHOUGH A FEW SHOWERS MAY
CLIP THE SOUTH SHORE FROM MID TO LATE EVENING. SCATTERED SHOWERS AND
STORMS WILL ALSO CROSS THE SAINT LAWRENCE VALLEY AND LIKELY CLIP
NORTHERN JEFFERSON COUNTY THROUGH MID EVENING.
FOLLOWING THE EVENING ACTIVITY...EXPECT A BREAK BY LATE EVENING WITH
THE LOSS OF DAYTIME HEATING WITH MOST OF THE CWA BECOMING DRY. OUR
ATTENTION WILL THEN TURN TO MORE SHOWERS AND STORMS NOW DEVELOPING
OVER WESTERN LAKE ERIE. THESE ARE FORMING WITHIN A BELT OF MODERATE
900-700MB FLOW...LIKELY THE RESULT OF WARM AND UNSTABLE AIR
ASCENDING THE COLD POOL LEFT BEHIND FROM THE FIRST MCS. RADAR TRENDS
AND SHORT TERM MESOSCALE MODEL GUIDANCE SUCH AS THE HRRR SUGGEST
THIS WILL CROSS THE SOUTHERN TIER DURING THE MIDDLE OF THE NIGHT
WITH SHOWERS AND A FEW STORMS.
BY LATE TONIGHT AND WEDNESDAY MORNING A SHORTWAVE AND VORTICITY
MAXIMA NOTED IN WATER VAPOR IMAGERY OVER NORTHERN WISCONSIN AT 00Z
WILL CROSS THE LOWER LAKES. THIS MAY TOUCH OFF A FEW MORE WIDELY
SCATTERED SHOWERS AND PERHAPS AN ISOLATED THUNDERSTORM...BUT THE
BEST FOCUS OF THE LOW LEVEL JET WILL BE WELL SOUTHEAST OF THE AREA
BY THEN. THIS TROUGH WILL MOVE INTO EASTERN NY AND NEW ENGLAND BY
18Z...SO ANY MORNING SHOWERS AND ISOLATED STORMS SHOULD CLEAR OUT
DURING THE AFTERNOON AS A BUBBLE OF SUBSIDENCE AND SOMEWHAT DRIER
AIR MOVES INTO THE LOWER LAKES.
WITH RESPECT TO TEMPS...EXPECT ANOTHER WARM AND MUGGY NIGHT WITH
LOWS IN THE MID TO UPPER 60S IN MOST LOCATIONS...AND EVEN A FEW 70
DEGREE LOWS ON THE LAKE PLAINS. ON WEDNESDAY EXPECT HIGHS IN THE
LOWER TO MID 80S AT LOWER ELEVATIONS AWAY FROM THE LAKES...WITH
UPPER 70S ALONG THE IMMEDIATE LAKESHORES.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
ATTENTION DURING THIS PERIOD WILL BE FOCUSED UPON A DEVELOPING LOW
PRESSURE SYSTEM THAT WILL TRACK ACROSS THE UPPER MIDWEST AND GREAT
LAKES...BRINGING ABUNDANT RAINFALL TO WESTERN AND NORTH-CENTRAL NEW
YORK ALONG WITH A RETURN TO MORE SEASONABLE TEMPERATURES. THE
SHORTWAVE THAT WILL ULTIMATELY BE RESPONSIBLE FOR THIS SYSTEM CAN
CURRENTLY BE SEEN ON WV IMAGERY OVER THE HIGH PLAINS OF EASTERN MT
AND THE WESTERN DAKOTAS. THIS SHORTWAVE WILL PROPAGATE
EAST-SOUTHEASTWARD ACROSS THE GREAT LAKES WEDNESDAY AND WEDNESDAY
NIGHT AS IT ROUNDS THE TOP OF AN AMPLIFYING RIDGE OVER THE WESTERN
UNITED STATES WITH A MID-LEVEL AND SURFACE CIRCULATION CLOSING OFF
ACROSS THE LOWER GREAT LAKES COURTESY OF A BROAD COUPLED UPPER LEVEL
JET STRUCTURE IN PLACE OVER THE REGION.
SHORTWAVE RIDGING AHEAD OF THIS LOW PRESSURE SYSTEM SHOULD RESULT IN
A GENERALLY DRY START TO WEDNESDAY NIGHT NIGHT ACROSS OUR FORECAST
AREA...HOWEVER AS THE NIGHT WEARS ON...EXPECT SHOWERS...ACCOMPANIED
BY A FEW RUMBLES OF THUNDER...TO PUSH INTO WESTERN NEW YORK. WEAK
INSTABILITY AND A LOW LEVEL JET THAT IS PROGGED TO STAY SOUTH AND
EAST OF THE FORECAST AREA SHOULD RULE OUT ANY SEVERE THREAT BOTH
WEDNESDAY NIGHT AND THURSDAY. ON THE OTHER HAND...THERE IS A CONCERN
REGARDING THE POTENTIAL FOR HEAVY RAIN AND LOCALIZED
FLOODING...PARTICULARLY ACROSS AREAS OF THE FINGER LAKES AND THE
GENESEE VALLEY THAT HAVE SEEN PLENTY OF RAINFALL OVER THE LAST FEW
DAYS. THE INGREDIENTS FOR HEAVY RAIN WILL CERTAINLY BE IN PLACE
ACROSS THE REGION WITH PWATS RUNNING BETWEEN 1.75 AND 2.0 INCHES AND
ABUNDANT SYNOPTIC LIFT. IN FACT MODELS ARE HINTING AT THE
DEVELOPMENT OF A TROWAL AS THE LOW TRACKS ACROSS NEW YORK THAT COULD
RESULT IN SIGNIFICANT RAINFALL. HOWEVER THE QUESTION REMAINS AS TO
WHERE THE FOCUS OF THE STRONGEST ASCENT ASSOCIATED WITH THE LOW WILL
BE LOCATED. THERE ARE DISCREPANCIES AMONG THE MODELS AS THE THE
EXACT TRACK AND SPEED OF THE LOW...NOT SURPRISING GIVEN THE
COMPLEXITY AND SUBTLETY OF THE FEATURES RESPONSIBLE FOR ITS
FORMATION...AND IT IS ALSO WORTH NOTING THAT SUCCESSIVE RUNS OF THE
GFS AND ECMWF HAVE BEEN TRENDING FARTHER SOUTH ON THE LOW TRACK WITH
THE GEM HAVING THE BULK OF THE HEAVY PRECIP MISSING OUR AREA
ENTIRELY AND STAYING ACROSS NORTHERN PA INTO CENTRAL NY. ALL OF THAT
SAID...WILL CONTINUE WITH CATEGORICAL POPS FOR THURSDAY AS WE SHOULD
STILL SEE WIDESPREAD SHOWER ACTIVITY EVEN IF THE HEAVIEST RAINS MISS
US.
AS WE MOVE INTO THURSDAY NIGHT...EXPECT SHOWERS TO CONTINUE ACROSS
MUCH OF WESTERN AND NORTH-CENTRAL NEW YORK AS THE LOW RECURVES
NORTHWARDS UP THE HUDSON VALLEY AND INTO THE SAINT LAWRENCE VALLEY
FRIDAY WHILE THE UPPER LEVEL TROUGH ESTABLISHES ITSELF OVER THE
GREAT LAKES. WITH NORTHERLY FLOW DEVELOPING ACROSS LAKE ONTARIO ON
THE BACK SIDE OF THE LOW...WE MAY EVEN SEE PRECIP EVOLVING MORE INTO
A DRIZZLE OVERNIGHT THURSDAY ACROSS THE UPSLOPE AREAS OF WESTERN NEW
YORK WHILE FARTHER EAST IN THE WARM SECTOR OF THE LOW THERE WILL
STILL BE A SLIGHT CHANCE OF A RUMBLE OF THUNDER. THIS TREND WILL
CONTINUE INTO FRIDAY WITH SHOWERS ACROSS WESTERN NEW YORK AND A
CHANCE OF THUNDER EAST OF ROCHESTER WHERE GREATER INSTABILITY WILL
BE FOUND.
TAKING A LOOK AT TEMPERATURES...WITH THE ABUNDANT CLOUD COVER MOVING
INTO THE REGION AND FALLING HEIGHTS ALOFT...TEMPERATURES WILL BE
FALLING BACK TO AROUND NORMAL FOR THIS TIME OF YEAR WITH HIGHS IN
THE UPPER 70S TO LOWER 80S THURSDAY AND MID TO UPPER 70S FRIDAY.
LOWS WILL BE CONSTRAINED BY THE CLOUD COVER AND HIGH DEWPOINTS WITH
LOWS RANGING FROM THE MID 60S NEAR THE LAKESHORES TO THE UPPER 50S
ACROSS THE HIGHER ELEVATIONS OF THE SOUTHERN TIER.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
UNSETTLED WEATHER WILL CONTINUE THROUGH THE WEEKEND AS A SERIES OF
SHORTWAVES DROPPING OUT OF THE CANADIAN PRAIRIE PROVINCES WILL
AMPLIFY THE TROUGH OVER THE GREAT LAKES WHILE THE PRESENCE OF THE
BERMUDA HIGH OVER THE WESTERN ATLANTIC KEEPS THIS TROUGH NEARLY
STATIONARY ACROSS THE REGION. GIVEN THE COOLER AIR ALOFT ASSOCIATED
WITH THIS TROUGH...WE CAN EXPECT DIURNAL INSTABILITY TO PRODUCE
PRIMARILY AFTERNOON/EVENING SHOWERS AND ISOLATED THUNDERSTORMS
THROUGH THE FORECAST PERIOD WITH TEMPERATURES TRENDING NEAR TO
SLIGHTLY BELOW NORMAL...IN THE MID TO UPPER 70S DURING THE DAYS AND
THE UPPER 50S TO LOWER 60S AT NIGHT.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS WILL PREVAIL MOST OF THE TIME FOR THE 00Z TAF
CYCLE...ALTHOUGH LOCALLY LOWER CONDITIONS WILL BE FOUND IN AND NEAR
CONVECTION. THROUGH THIS EVENING...AN AREA OF LIGHT RAIN WILL END
ACROSS THE SOUTHERN TIER WITH MAINLY VFR CONDITIONS. SCATTERED
STORMS OVER LAKE ONTARIO TO THE SAINT LAWRENCE VALLEY WILL PRODUCE
LOCAL/BRIEF IFR CONDITIONS BUT SHOULD AVOID MOST OF THE TAF SITES.
OVERNIGHT ADDITIONAL CONVECTION OVER SOUTHERN LOWER MICHIGAN AND
WESTERN LAKE ERIE MAY CROSS THE SOUTHERN TIER WITH A PERIOD OF MVFR
TO IFR CONDITIONS WHICH MAY IMPACT KJHW. A MID LEVEL DISTURBANCE MAY
ALSO PRODUCE MORE WIDELY SCATTERED SHOWERS AND PERHAPS A
THUNDERSTORM ACROSS THE REST OF THE AREA LATE TONIGHT AND WEDNESDAY
MORNING.
FOLLOWING THE PASSAGE OF THE MID LEVEL DISTURBANCE BY MIDDAY
WEDNESDAY...EXPECT SKIES TO CLEAR WITH VFR THROUGH WEDNESDAY
AFTERNOON AND EVENING.
OUTLOOK...
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS...SOME OF WHICH WILL PRODUCE REDUCTIONS TO
IFR/MVFR.
FRIDAY...VFR/MVFR WITH SCATTERED TO NUMEROUS SHOWERS.
SATURDAY AND SUNDAY...MAINLY VFR WITH A CHANCE OF SHOWERS AND
THUNDERSTORMS.
&&
.MARINE...
SOUTHWEST WINDS ARE STARTING TO DIMINISH THIS EVENING ON LAKE ERIE
WITH WAVES NOW SUBSIDING BELOW SMALL CRAFT ADVISORY CRITERIA. WAVES
MAY REMAIN A LITTLE CHOPPY THROUGH WEDNESDAY MORNING IN THE 2-3 FOOT
RANGE OCCASIONALLY...BEFORE SUBSIDING FURTHER WEDNESDAY AFTERNOON.
OTHERWISE...A BERMUDA HIGH SITUATED OVER THE WESTERN ATLANTIC WILL
KEEP A RELATIVELY WEAK PRESSURE GRADIENT OVER LAKE ONTARIO THROUGH
WEDNESDAY...RESULTING IN LIGHT TO MODEST SOUTHWESTERLY WINDS AND
WINDS AND NEGLIGIBLE WAVES. LATER IN THE WEEK...WINDS AND WAVES WILL
INCREASE SOME AS AN AREA OF LOW PRESSURE CROSSES THE REGION.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TJP
NEAR TERM...HITCHCOCK/TJP
SHORT TERM...WOOD
LONG TERM...WOOD
AVIATION...HITCHCOCK
MARINE...HITCHCOCK/TJP
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1016 AM EDT MON JUN 24 2013
.SYNOPSIS...
VERY WARM AND HUMID CONDITIONS WILL REMAIN IN PLACE ACROSS THE
REGION FOR THE BULK OF THIS WEEK...BUT UNLIKE THE PAST FEW DAYS WHEN
THUNDERSTORMS WERE FEW AND FAR BETWEEN...CONVECTION WILL GRADUALLY
BECOME MORE WIDESPREAD.
&&
.NEAR TERM /THROUGH TONIGHT/...
12Z BUF SOUNDING SHOWS MORE INSTABILITY AND PRECIPITABLE WATER
COMPARED TO YESTERDAY. IN ADDITION...WILL HAVE TO DEAL WITH UPPER
LEVEL TROUGH CLEARLY SEEN IN WATER VAPOR IMAGERY OVER PA MOVING NE.
EXPECT CONVECTION TO FIRE ONCE WE CAN GET SOME SURFACE BASED LIFT
EARLY THIS AFTERNOON...PROBABLY ALONG A LAKE ERIE BREEZE SIMILAR TO
SUNDAY. THIS SHOULD BE ON THE NW OR W SIDE OF THE ABOVE MENTIONED
UPPER LEVEL DISTURBANCE. WINDS ALOFT ARE FORECAST TO BE ABOUT 15-20
KTS...ALTHOUGH PRECIPITABLE WATER IS EXPECTED TO BE ON THE
DECREASE. THERE WILL BE A THREAT FOR SLOW MOVING STORMS AGAIN
TODAY...BUT CONFIDENCE IS NOT HIGH ENOUGH FOR A FLASH FLOOD WATCH.
BASED ON MESOSCALE MODEL GUIDANCE /SSEO AND HRRR AND LOCAL MODELS/
THE BIGGEST THREAT APPEARS TO BE WELL INLAND...FINGER LAKES AND/OR
CENTRAL NY. WILL KEEP THE WELL THOUGHT OUT LIKELY POPS FROM
CONTINUITY FOR THAT REGION. OTHERWISE...EXPECT ANOTHER WARM/HUMID
DAY WITH PARTIAL SUNSHINE.
WARMING MID LEVELS AND GENERAL SUBSIDENCE WILL BE FOUND IN THE WAKE
OF THE EXITING CIRCULATION MONDAY NIGHT. THIS IN COMBINATION WITH
THE WEAKENING OF THE DIURNAL INSTABILITY SHOULD LEAD TO ANOTHER FAIR
WARM AND HUMID NIGHT...ALTHOUGH CONVECTION IN THE AFOREMENTIONED
AREAS WILL STILL BE WANING DURING THE EVENING HOURS.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
ON TUESDAY...YET ANOTHER IN A SERIES OF MID LEVEL SHORTWAVES WILL
WORK FROM THE CENTRAL TO LOWER GREAT LAKES IN THE NEARLY ZONAL FLOW
ALOFT. WHILE THE 00Z GUIDANCE SUITE CONTINUES TO SHOW SOME
DISAGREEMENT IN THE TIMING OF THIS WAVE...A ROUGH MODEL CONSENSUS
SUGGESTS THAT THIS FEATURE WILL AT LEAST GET CLOSE ENOUGH TO ACT AS
A TRIGGER FOR CONVECTION AT SOME POINT...POTENTIALLY AS EARLY AS
TUESDAY MORNING ACROSS FAR WESTERN NEW YORK PER THE MORE CONSISTENT
GFS/ECMWF SOLUTIONS. COUPLED WITH DIURNAL HEATING OF OUR VERY WARM
AND HUMID AIRMASS AND RESULTANT SBCAPES OF 1000-2000 J/KG...THIS
SHOULD RESULT IN ANOTHER ROUND OF AT LEAST SCATTERED CONVECTION
AREAWIDE. THE GREATEST AREAL COVERAGE WILL ONCE AGAIN BE MOST LIKELY
FROM THE SOUTHERN TIER NORTHEASTWARD ACROSS THE GENESEE VALLEY/
FINGER LAKES TO INTERIOR PORTIONS OF THE NORTH COUNTRY...WHERE LOW
LEVEL INSTABILITY WILL BE MAXIMIZED AND LAKE BREEZE BOUNDARIES
SHOULD PROVIDE ADDED LOCALIZED LIFT OF THE UNSTABLE AIRMASS. A
SLIGHTLY STRONGER MID LEVEL TROPOSPHERIC FLOW COMPARED TO THE
PREVIOUS FEW DAYS SHOULD MEAN THAT THERE WILL AT LEAST BE A SOMEWHAT
LOWER RISK FOR LOCALIZED HEAVY RAINFALL/FLOODING...HOWEVER THIS
MAY ALSO LEAD TO A SOMEWHAT GREATER POTENTIAL FOR A FEW STRONGER
STORMS...PARTICULARLY ACROSS THE NORTH COUNTRY AND SAINT LAWRENCE
VALLEY WHERE THE OVERALL MID LEVEL FLOW SHOULD BE STRONGEST.
DURING THE COURSE OF TUESDAY NIGHT...CONVECTION SHOULD GENERALLY BE
ON A DOWNWARD TREND THROUGH MUCH OF THE THE NIGHT...THOUGH THE EXACT
SPEED OF THIS DIMINISHING TREND NOW APPEARS TO BE MUCH MORE IN
QUESTION COMPARED TO 24 HOURS AGO. OF THE AVAILABLE GUIDANCE...THE
ECMWF REMAINS VERY CONSISTENT WITH ITS PREVIOUS RUNS IN ADVECTING A
SUBSTANTIAL SURGE OF DRIER AIR ALOFT INTO THE AREA IN THE WAKE OF
TUESDAY`S SHORTWAVE AND ITS ATTENDANT WEAK FRONTAL BOUNDARY ...WHICH
RESULTS IN CONVECTION QUICKLY DIMINISHING ACROSS THE AREA DURING THE
EVENING...FOLLOWED BY MAINLY DRY WEATHER FOR A TIME BEFORE SOME
ADDITIONAL UPSTREAM CONVECTION ARRIVES LATER ON IN THE NIGHT. IN
CONTRAST...THE GFS/GEM ARE A BIT SLOWER WITH THE DEPARTURE OF
SHORTWAVE ENERGY ALOFT...AND CONSEQUENTLY ADVECT ANOTHER ROUND OF
UPSTREAM CONVECTION /AND POTENTIALLY AN MCS/ ACROSS THE AREA DURING
THE EVENING...FOLLOWED BY DECENT DRYING FROM WEST TO EAST OVERNIGHT.
MEANWHILE...THE NAM IS A SUBSTANTIAL OUTLIER IN LINGERING THE
AFOREMENTIONED SURFACE FRONT ACROSS THE AREA THROUGH THE NIGHT...
WITH ADDITIONAL CONVECTION RIPPLING EAST ALONG AND NORTH OF THIS
BOUNDARY RIGHT THROUGH THE NIGHT.
THROWING OUT THE 00Z NAM...WHICH IS OUT OF SYNC WITH ALL OF THE
OTHER GUIDANCE AND PER EXPERIENCE IS USUALLY NOT AS RELIABLE THIS
FAR OUT...WILL AIM MORE CONSERVATIVE AND KEEP AT LEAST A LOW CHANCE
OF CONVECTION IN AREAWIDE FOR THE FIRST HALF OF THE NIGHT GIVEN THE
AFOREMENTIONED UNCERTAINTIES IN TIMING...FOLLOWED BY A RETURN TO
MAINLY DRY CONDITIONS OVERNIGHT FOLLOWING A ECMWF/GFS/GEM CONSENSUS
AND OUR PREVIOUS CONTINUITY.
ON WEDNESDAY...IT APPEARS TO BE A CASE OF DEJA VU AS THE NEXT AND
POTENTIALLY STRONGER SHORTWAVE TROUGH AND ASSOCIATED SURFACE
REFLECTION SETTLES ACROSS THE GREAT LAKES...WITH AN ASSOCIATED WARM
FRONTAL BOUNDARY DEVELOPING EASTWARD ACROSS THE LOWER GREAT LAKES
AND NEW YORK STATE. COUPLED WITH INCREASING DAYTIME INSTABILITY...
THIS WILL ONCE AGAIN LEAD TO INCREASING CHANCES OF CONVECTION FROM
WEST TO EAST...AGAIN POTENTIALLY BEGINNING EARLY IN THE DAY ACROSS
EXTREME FAR WESTERN NEW YORK AS THE LEAD EDGE OF THIS NEXT SYSTEM
INTERACTS WITH SOME ELEVATED INSTABILITY. AS SUCH...WILL HAVE
BROADBRUSH CHANCE POPS IN PLAY...AND GENERALLY INCREASING FROM WEST
TO EAST THROUGH THE COURSE OF THE DAY.
WEDNESDAY NIGHT AND THURSDAY...THE AXIS OF THE AFOREMENTIONED
SHORTWAVE TROUGH AND MODEST SURFACE WAVE WILL TRANSLATE FURTHER
EAST INTO THE LOWER GREAT LAKES AND NEW YORK STATE. THIS WILL LEAD
TO A FURTHER UPTICK IN CONVECTIVE CHANCES...PARTICULARLY DURING THE
DAY ON THURSDAY WHEN THESE FEATURES WILL MOVE OVERHEAD...AND WILL
ONCE AGAIN BE ABLE TO TAKE ADVANTAGE OF INCREASING DIURNAL
INSTABILITY. WILL THUS CONTINUE TO INDICATE AN INCREASING TREND IN
POPS THROUGH THESE TWO PERIODS...CULMINATING IN A MIX OF HIGH CHANCE
TO LOW LIKELY VALUES ON THURSDAY...WITH THE HIGHEST VALUES ACROSS
THE NORTH COUNTRY/SAINT LAWRENCE VALLEY...WHICH WILL BE ALONG AND
NORTH OF THE TRACK OF THE SURFACE LOW/ATTENDANT WARM FRONT. THURSDAY
NIGHT...WILL KEEP BROADBRUSH HIGH CHANCE POPS ACROSS THE REGION AS
THE BROAD SURFACE WAVE LINGERS IN PLACE OVERHEAD...AND THE MID LEVEL
SHORTWAVE TROUGH BEGINS TO DEEPEN AS IT STARTS TO GET REINFORCED BY
ADDITIONAL SHORTWAVE ENERGY DROPPING SOUTHEAST FROM CENTRAL CANADA.
AS FOR TEMPERATURES...WARM AND HUMID WEATHER WILL CONTINUE TO BE THE
RULE THROUGH THIS PERIOD AS 850 MB TEMPS REMAIN LOCKED IN THE +16C
TO +18C RANGE...AND SURFACE DEWPOINTS LINGER IN THE MID TO UPPER
60S. THE WARMEST TEMPS WILL LIKELY OCCUR TUESDAY AND WEDNESDAY WHEN
PRECIPITATION/CLOUD COVERAGE WILL BE SOMEWHAT LESS...ALLOWING HIGH
TEMPS TO REACH INTO THE MID-UPPER 80S IN MOST PLACES...THOUGH AREAS
IMMEDIATELY NORTHEAST OF THE LAKES WILL LIKELY BE SOMEWHAT COOLER
DUE TO THE PREVAILING SOUTHWESTERLY LOW LEVEL FLOW. THURSDAY WILL
THEN LIKELY BE A LITTLE COOLER AS CONVECTIVE COVERAGE INCREASES...
WITH READINGS GENERALLY PEAKING IN THE LOWER TO MID 80S.
MEANWHILE...NIGHTTIME PERIODS WILL REMAIN RATHER SULTRY...WITH TEMPS
ONLY SETTLING INTO THE 65-70 DEGREE RANGE EACH NIGHT.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
DURING THE LONG TERM PERIOD...ROBUST LARGE-SCALE TROUGHING WILL
DEVELOP ACROSS OUR REGION AS PLENTIFUL SHORTWAVE ENERGY OVER
CENTRAL CANADA DROPS SOUTHEASTWARD INTO THE EXISTING MODEST MID
LEVEL TROUGH OVER THE GREAT LAKES...EVENTUALLY CARVING OUT A
SUBSTANTIAL UPPER LEVEL TROUGH IN THE PROCESS. THIS WILL RESULT IN
CONTINUED UNSETTLED WEATHER RIGHT THROUGH NEXT WEEKEND AS HEIGHT
FALLS/COOLING TEMPS ALOFT OVERSPREAD LINGERING WARM AND HUMID AIR
IN THE BOUNDARY LAYER. THIS WILL ESPECIALLY BE THE CASE DURING THE
DAYLIGHT HOURS OF FRIDAY AND SATURDAY WHEN THE BEST COMBINATIONS
OF INSTABILITY... AVAILABLE MOISTURE...AND LARGE-SCALE FORCING
WILL BE REALIZED... FOR WHICH HIGH CHANCE TO LOW LIKELY POPS WILL
BE IN PLAY. BY SUNDAY...CONVECTIVE POTENTIAL AND COVERAGE SHOULD
BEGIN TO LOWER SOMEWHAT AS THE AXIS OF DEEPEST MOISTURE ASSOCIATED
WITH THE TROUGH SHIFTS A LITTLE TO OUR EAST...THOUGH SCATTERED
SHOWERS AND STORMS WILL REMAIN A DISTINCT POSSIBILITY.
OVER TIME...THIS EVOLUTION IN THE PATTERN WILL ALSO LEAD TO A
GRADUAL AND MODEST REDUCTION IN TEMPERATURE AND HUMIDITY LEVELS AS
SOMEWHAT COOLER/DRIER AIR WORKS INTO OUR REGION...WITH READINGS
FALLING BACK TO NORMAL EARLY SUMMER LEVELS BY NEXT WEEKEND. MORE
SPECIFICALLY...850 MB TEMPS WILL GRADUALLY SETTLE FROM THE MID TEENS
BACK TO THE +12C TO +14C RANGE...AND THIS COUPLED WITH INCREASED
CLOUD COVER AND PRECIPITATION WILL RESULT IN DAYTIME HIGHS SLIPPING
BACK TO THE UPPER 70S/LOWER 80S FOR FRIDAY AND SATURDAY...AND THE
MID AND UPPER 70S BY SUNDAY. MEANWHILE...SURFACE DEWPOINTS WILL DROP
BACK TO SOMEWHAT MORE COMFORTABLE LEVELS IN THE UPPER 50S/LOWER 60S.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
WHILE VFR CONDITIONS WILL BE FOUND AT ALL OF THE COMMERCIAL AVIATION
SITES THIS AFTERNOON...THERE WILL BE AN INCREASED THREAT FOR
CONVECTION. THIS WILL MAINLY BE THE CASE OVER THE SRN TIER AND
FINGER LAKES REGION... WHERE SLOW MOVING THUNDERSTORMS THIS
AFTERNOON AND EVENING COULD PRODUCE HEAVY RAINS AND POSSIBLY SOME
SMALL HAIL. ANY SUCH CONVECTION WILL THEN WEAKEN AND DISSIPATE
WITHIN A COUPLE HOURS AFTER SUNSET...LEAVING MAINLY VFR CONDITIONS
IN PLACE FOR TONIGHT.
OUTLOOK...
TUESDAY THROUGH THURSDAY...MAINLY VFR WITH A CHANCE OF SHOWERS AND
THUNDERSTORMS.
&&
.MARINE...
HIGH PRESSURE WELL OFF THE SOUTHEAST COAST WILL KEEP A RELATIVELY
WEAK SFC PRESSURE GRADIENT OVER THE LOWER GREAT LAKES INTO THE
MIDDLE OF THE COMING WEEK. THIS WILL RESULT IN LIGHT SOUTH TO
SOUTHWEST WINDS ON BOTH LAKES ERIE AND ONTARIO...WITH NEGLIGIBLE
WAVES.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RSH
NEAR TERM...RSH/ZAFF
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...RSH/ZAFF
MARINE...RSH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1048 PM CDT TUE JUN 25 2013
.UPDATE...
ISSUED AT 1047 PM CDT TUE JUN 25 2013
SEVERE THUNDERSTORM WATCH HAS BEEN CANCELLED FOR ALL BUT FOSTER...
STUTSMAN...DICKEY AND LAMOURE COUNTIES. HAVE ONCE AGAIN UPDATED
FOR LATEST RADAR TRENDS...REMOVING ALL POPS BUT FOR THE REMAINING
COUNTIES IN THE SEVERE THUNDERSTORM WATCH. THIS ACTIVITY SHOULD BE
OUT OF THE CWA AROUND MIDNIGHT. WILL ALSO CANCEL THE REMAINING
COUNTIES OF THE FLASH FLOOD WATCH SHORTLY.
UPDATE ISSUED AT 849 PM CDT TUE JUN 25 2013
HAVE REMOVED ANOTHER TIER OF COUNTIES FROM THE SEVERE THUNDERSTORM
AND FLASH FLOOD WATCHES. ALSO ADJUSTED POPS BASED ON CURRENT RADAR.
OTHERWISE NO SIGNIFICANT CHANGES TO THE GOING FORECAST. UPDATED
FLASH FLOOD WATCH AND WCN PRODUCTS HAVE BEEN SENT. REMAINING
UPDATED PRODUCTS OUT SHORTLY.
UPDATE ISSUED AT 708 PM CDT TUE JUN 25 2013
CONVECTION ACROSS CENTRAL NORTH DAKOTA CONTINUES TO MOVE
NORTHEAST. WIND SHIFT HAS MOVED THROUGH NORTHWEST...INTO THE SOUTH
CENTRAL PORTION OF THE STATE. THUS HAVE DROPPED WESTERN PORTIONS
OF THE SEVERE THUNDERSTORM WATCH INCLUDING MORTON...MERCER...
OLIVER...DIVIDE AND WILLIAMS. HAVE ALSO DROPPED WESTERN PORTIONS
OF THE FLASH FLOOD WATCH. THESE UPDATES HAVE BEEN SENT.
MAIN UPDATES WERE TO ADJUST POPS TO CURRENT RADAR TRENDS. UPDATED
ZONES AND STATE WILL BE SENT SHORTLY.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 200 PM CDT TUE JUN 25 2013
FORECAST HIGHLIGHTS IN THE SHORT TERM FORECAST PERIOD WILL BE
STRONG TO SEVERE THUNDERSTORMS AND HEAVY RAIN POTENTIAL THROUGH
THIS EVENING.
CURRENTLY...WARM AND VERY HUMID DAY WITH DAYTIME HIGHS IN THE 80S
AND SURFACE DEWPOINT TEMPS FROM 60 TO THE LOW 70S. LATEST RADAR IS
VOID OF ECHOS OVER WEST AND CENTRAL NORTH DAKOTA AS OF 2 PM CDT.
LATEST MODEL GUIDANCE SUGGESTS CONVECTIVE DEVELOPMENT
NORTHWEST/NORTH CENTRAL EARLY THIS AFTERNOON...BUILDING SOUTH-
SOUTHEAST LATE AFTERNOON-EARLY EVENING ALONG A SURFACE TROUGH IN
PLACE FROM NORTHWEST NORTH DAKOTA THROUGH CENTRAL SOUTH DAKOTA.
17-18Z RAP SOUNDINGS WEAKEN/ERASE THE CAP BETWEEN 20-22Z ALONG THE
SFC TROUGH AXIS. TRIGGER WILL BE A STRONG MID LEVEL S/WV PUSHING
INTO WESTERN NORTH DAKOTA NOW...HELPING TO WEAKEN THE STRONG
CAPPING INVERSION CURRENTLY IN PLACE. CONVECTION SHOULD THEN PUSH
EAST THIS EVENING INTO THE OVERNIGHT WITH THE MID LEVEL WAVE AND
SFC TROUGH. STRONG TO SEVERE WEATHER REMAINS IN PLAY WITH THE VERY
STRONG INSTABILITY PRESENT...CURRENTLY 3-6K J/KG. LIMITING FACTOR
WILL BE RATHER WEAK 0-6KM/EFFECTIVE SHEAR UP TO AROUND 20KTS
CURRENTLY IN PLACE AND FORECAST THROUGH THIS EVENING. STILL...WITH
THE AMOUNT OF CAPE PRESENT THERE IS A GOOD PROBABILITY OF LARGE
SEVERE HAIL AND A DAMAGING WIND GUSTS. STORMS WILL BE WATER
LOADED SO WILL LIKELY NEED A RATHER ROBUST/TALL UPDRAFT TO GET THE
LARGE HAIL. IT DOES APPEAR THE MAIN THREAT TODAY INTO THIS EVENING
WILL BE VERY HEAVY RAINFALL ELEVATING THE THREAT FOR FLASH
FLOODING.
CONVECTIVE CHANCES WILL END FROM WEST TO EAST THIS EVENING THROUGH
WEDNESDAY MORNING AS FORCING PUSHES EASTWARD.
OPTED TO KEEP WEDNESDAY AFTERNOON DRY FOR NOW ALONG WITH THE 12Z
GFS/00Z ECMWF. THE 06Z AND 12Z NAM BOTH PAINTED LIGHT DIURNALLY
DRIVEN QPF...SO WILL LET LATER SHIFTS TAKE A LOOK WITH ATTENTION
FOCUSED ON THE NEXT 12 HOURS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 200 PM CDT TUE JUN 25 2013
THE MAIN FEATURE FOR THE EXTENDED PERIOD WILL BE THE INTENSIFYING
UPPER LEVEL RIDGE OVER THE WESTERN US/CANADA AS FORECAST BY THE 12Z
MODEL SUITE. WITH THE RIDGE AXIS POSITIONED OVER THE INTERMOUNTAIN
WEST...NORTH TO NORTHWESTERLY FLOW WILL BE DOMINANT ACROSS NORTH
DAKOTA FOR MUCH OF THE PERIOD. THIS WILL ALLOW FOR SEASONABLE
TEMPERATURES...IN THE 80S TO CONTINUE...KEEPING THE AREA OUT THE
WARMEST H850 TEMPERATURES THAT WILL DEVELOP ACROSS THE WESTERN US.
OVERALL THE FORECAST WILL REMAIN DRY...HOWEVER THERE WILL BE
PERIODIC CHANCES FOR PRECIPITATION FOR PARTS OF CENTRAL AND EASTERN
NORTH DAKOTA...AS A FEW SHORTWAVES ROTATE AROUND THE WESTERN
PERIPHERY OF THE UPPER LEVEL LOW POSITIONED OVER THE GREAT LAKES
REGION. LATE THIS WEEKEND/EARLY NEXT WEEK...SOME UNCERTAINTY IS
INTRODUCED INTO THE FORECAST AS THE THERE IS SOME DISAGREEMENT
AMONGST THE 12Z LONG RANGE MODELS REGARDING THE POTENT SHORTWAVE
THAT IS PROGGED TO DROP SOUTH FROM CANADA AND INTO THE NORTHERN
PLAINS. DUE TO THIS UNCERTAINTY...WILL MAKE NO CHANGES TO THE
ALLBLEND SOLUTION AT THIS TIME SINCE THERE IS NO TARGET OF
OPPORTUNITY TO IMPROVE FORECAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1047 PM CDT TUE JUN 25 2013
THUNDERSTORM THREAT HAS ENDED ACROSS ALL BUT KJMS TAF. WILL CARRY
A MENTION OF THUNDER THROUGH AROUND 05Z. OTHERWISE...SOUTHWEST TO
WEST FLOW WILL CONTINUE TO PROGRESS EAST BRINGING AN END TO
THUNDERSTORMS ACROSS EASTERN PORTIONS OF CENTRAL NORTH DAKOTA. VFR
CONDITIONS EXPECTED FOR THE REMAINDER OF TONIGHT AND WEDNESDAY
WITH A WEST TO NORTHWEST FLOW.
&&
.HYDROLOGY...
ISSUED AT 200 PM CDT TUE JUN 25 2013
A FLASH FLOOD WATCH REMAINS IN EFFECT FOR NORTHWEST AND CENTRAL
NORTH DAKOTA THROUGH THIS EVENING. VERY SLOW MOVING THUNDERSTORMS
WITH INTENSE RAINFALL RATES ARE EXPECTED. ONE HOUR FLASH FLOOD
GUIDANCE IS AROUND ONE TO ONE AND A HALF INCHES ACROSS MOST OF THE
WATCH AREA. RAINFALL RATES WITH THUNDERSTORMS TODAY WILL EASILY
SURPASS THIS THRESHOLD...AND WILL HAVE TO CLOSELY MONITOR FOR
FLASH FLOODING THIS AFTERNOON AND EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
LONG TERM...LTH
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
850 PM CDT TUE JUN 25 2013
.UPDATE...
ISSUED AT 849 PM CDT TUE JUN 25 2013
HAVE REMOVED ANOTHER TIER OF COUNTIES FROM THE SEVERE THUNDERSTORM
AND FLASH FLOOD WATCHES. ALSO ADJUSTED POPS BASED ON CURRENT RADAR.
OTHERWISE NO SIGNIFICANT CHANGES TO THE GOING FORECAST. UPDATED
FLASH FLOOD WATCH AND WCN PRODUCTS HAVE BEEN SENT. REMAINING
UPDATED PRODUCTS OUT SHORTLY.
UPDATE ISSUED AT 708 PM CDT TUE JUN 25 2013
CONVECTION ACROSS CENTRAL NORTH DAKOTA CONTINUES TO MOVE
NORTHEAST. WIND SHIFT HAS MOVED THROUGH NORTHWEST...INTO THE SOUTH
CENTRAL PORTION OF THE STATE. THUS HAVE DROPPED WESTERN PORTIONS
OF THE SEVERE THUNDERSTORM WATCH INCLUDING MORTON...MERCER...
OLIVER...DIVIDE AND WILLIAMS. HAVE ALSO DROPPED WESTERN PORTIONS
OF THE FLASH FLOOD WATCH. THESE UPDATES HAVE BEEN SENT.
MAIN UPDATES WERE TO ADJUST POPS TO CURRENT RADAR TRENDS. UPDATED
ZONES AND STATE WILL BE SENT SHORTLY.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 200 PM CDT TUE JUN 25 2013
FORECAST HIGHLIGHTS IN THE SHORT TERM FORECAST PERIOD WILL BE
STRONG TO SEVERE THUNDERSTORMS AND HEAVY RAIN POTENTIAL THROUGH
THIS EVENING.
CURRENTLY...WARM AND VERY HUMID DAY WITH DAYTIME HIGHS IN THE 80S
AND SURFACE DEWPOINT TEMPS FROM 60 TO THE LOW 70S. LATEST RADAR IS
VOID OF ECHOS OVER WEST AND CENTRAL NORTH DAKOTA AS OF 2 PM CDT.
LATEST MODEL GUIDANCE SUGGESTS CONVECTIVE DEVELOPMENT
NORTHWEST/NORTH CENTRAL EARLY THIS AFTERNOON...BUILDING SOUTH-
SOUTHEAST LATE AFTERNOON-EARLY EVENING ALONG A SURFACE TROUGH IN
PLACE FROM NORTHWEST NORTH DAKOTA THROUGH CENTRAL SOUTH DAKOTA.
17-18Z RAP SOUNDINGS WEAKEN/ERASE THE CAP BETWEEN 20-22Z ALONG THE
SFC TROUGH AXIS. TRIGGER WILL BE A STRONG MID LEVEL S/WV PUSHING
INTO WESTERN NORTH DAKOTA NOW...HELPING TO WEAKEN THE STRONG
CAPPING INVERSION CURRENTLY IN PLACE. CONVECTION SHOULD THEN PUSH
EAST THIS EVENING INTO THE OVERNIGHT WITH THE MID LEVEL WAVE AND
SFC TROUGH. STRONG TO SEVERE WEATHER REMAINS IN PLAY WITH THE VERY
STRONG INSTABILITY PRESENT...CURRENTLY 3-6K J/KG. LIMITING FACTOR
WILL BE RATHER WEAK 0-6KM/EFFECTIVE SHEAR UP TO AROUND 20KTS
CURRENTLY IN PLACE AND FORECAST THROUGH THIS EVENING. STILL...WITH
THE AMOUNT OF CAPE PRESENT THERE IS A GOOD PROBABILITY OF LARGE
SEVERE HAIL AND A DAMAGING WIND GUSTS. STORMS WILL BE WATER
LOADED SO WILL LIKELY NEED A RATHER ROBUST/TALL UPDRAFT TO GET THE
LARGE HAIL. IT DOES APPEAR THE MAIN THREAT TODAY INTO THIS EVENING
WILL BE VERY HEAVY RAINFALL ELEVATING THE THREAT FOR FLASH
FLOODING.
CONVECTIVE CHANCES WILL END FROM WEST TO EAST THIS EVENING THROUGH
WEDNESDAY MORNING AS FORCING PUSHES EASTWARD.
OPTED TO KEEP WEDNESDAY AFTERNOON DRY FOR NOW ALONG WITH THE 12Z
GFS/00Z ECMWF. THE 06Z AND 12Z NAM BOTH PAINTED LIGHT DIURNALLY
DRIVEN QPF...SO WILL LET LATER SHIFTS TAKE A LOOK WITH ATTENTION
FOCUSED ON THE NEXT 12 HOURS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 200 PM CDT TUE JUN 25 2013
THE MAIN FEATURE FOR THE EXTENDED PERIOD WILL BE THE INTENSIFYING
UPPER LEVEL RIDGE OVER THE WESTERN US/CANADA AS FORECAST BY THE 12Z
MODEL SUITE. WITH THE RIDGE AXIS POSITIONED OVER THE INTERMOUNTAIN
WEST...NORTH TO NORTHWESTERLY FLOW WILL BE DOMINANT ACROSS NORTH
DAKOTA FOR MUCH OF THE PERIOD. THIS WILL ALLOW FOR SEASONABLE
TEMPERATURES...IN THE 80S TO CONTINUE...KEEPING THE AREA OUT THE
WARMEST H850 TEMPERATURES THAT WILL DEVELOP ACROSS THE WESTERN US.
OVERALL THE FORECAST WILL REMAIN DRY...HOWEVER THERE WILL BE
PERIODIC CHANCES FOR PRECIPITATION FOR PARTS OF CENTRAL AND EASTERN
NORTH DAKOTA...AS A FEW SHORTWAVES ROTATE AROUND THE WESTERN
PERIPHERY OF THE UPPER LEVEL LOW POSITIONED OVER THE GREAT LAKES
REGION. LATE THIS WEEKEND/EARLY NEXT WEEK...SOME UNCERTAINTY IS
INTRODUCED INTO THE FORECAST AS THE THERE IS SOME DISAGREEMENT
AMONGST THE 12Z LONG RANGE MODELS REGARDING THE POTENT SHORTWAVE
THAT IS PROGGED TO DROP SOUTH FROM CANADA AND INTO THE NORTHERN
PLAINS. DUE TO THIS UNCERTAINTY...WILL MAKE NO CHANGES TO THE
ALLBLEND SOLUTION AT THIS TIME SINCE THERE IS NO TARGET OF
OPPORTUNITY TO IMPROVE FORECAST.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 849 PM CDT TUE JUN 25 2013
THUNDERSTORM THREAT HAS ENDED ACROSS ALL BUT KJMS TAF. WILL CARRY
A MENTION OF THUNDER THROUGH AROUND 03Z. OTHERWISE...SOUTHWEST TO
WEST FLOW WILL CONTINUE TO PROGRESS EAST BRINGING AN END TO
THUNDERSTORMS ACROSS EASTERN PORTIONS OF CENTRAL NORTH DAKOTA. VFR
CONDITIONS EXPECTED FOR THE REMAINDER OF TONIGHT AND WEDNESDAY
WITH A WEST TO NORTHWEST FLOW.
&&
.HYDROLOGY...
ISSUED AT 200 PM CDT TUE JUN 25 2013
A FLASH FLOOD WATCH REMAINS IN EFFECT FOR NORTHWEST AND CENTRAL
NORTH DAKOTA THROUGH THIS EVENING. VERY SLOW MOVING THUNDERSTORMS
WITH INTENSE RAINFALL RATES ARE EXPECTED. ONE HOUR FLASH FLOOD
GUIDANCE IS AROUND ONE TO ONE AND A HALF INCHES ACROSS MOST OF THE
WATCH AREA. RAINFALL RATES WITH THUNDERSTORMS TODAY WILL EASILY
SURPASS THIS THRESHOLD...AND WILL HAVE TO CLOSELY MONITOR FOR
FLASH FLOODING THIS AFTERNOON AND EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 1 AM CDT WEDNESDAY FOR NDZ004-005-012-
013-023-025-036-037-047-048-050-051.
&&
$$
UPDATE...TWH
LONG TERM...LTH
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
707 PM CDT TUE JUN 25 2013
.UPDATE...
ISSUED AT 708 PM CDT TUE JUN 25 2013
CONVECTION ACROSS CENTRAL NORTH DAKOTA CONTINUES TO MOVE
NORTHEAST. WIND SHIFT HAS MOVED THROUGH NORTHWEST...INTO THE SOUTH
CENTRAL PORTION OF THE STATE. THUS HAVE DROPPED WESTERN PORTIONS
OF THE SEVERE THUNDERSTORM WATCH INCLUDING MORTON...MERCER...
OLIVER...DIVIDE AND WILLIAMS. HAVE ALSO DROPPED WESTERN PORTIONS
OF THE FLASH FLOOD WATCH. THESE UPDATES HAVE BEEN SENT.
MAIN UPDATES WERE TO ADJUST POPS TO CURRENT RADAR TRENDS. UPDATED
ZONES AND STATE WILL BE SENT SHORTLY.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 200 PM CDT TUE JUN 25 2013
FORECAST HIGHLIGHTS IN THE SHORT TERM FORECAST PERIOD WILL BE
STRONG TO SEVERE THUNDERSTORMS AND HEAVY RAIN POTENTIAL THROUGH
THIS EVENING.
CURRENTLY...WARM AND VERY HUMID DAY WITH DAYTIME HIGHS IN THE 80S
AND SURFACE DEWPOINT TEMPS FROM 60 TO THE LOW 70S. LATEST RADAR IS
VOID OF ECHOS OVER WEST AND CENTRAL NORTH DAKOTA AS OF 2 PM CDT.
LATEST MODEL GUIDANCE SUGGESTS CONVECTIVE DEVELOPMENT
NORTHWEST/NORTH CENTRAL EARLY THIS AFTERNOON...BUILDING SOUTH-
SOUTHEAST LATE AFTERNOON-EARLY EVENING ALONG A SURFACE TROUGH IN
PLACE FROM NORTHWEST NORTH DAKOTA THROUGH CENTRAL SOUTH DAKOTA.
17-18Z RAP SOUNDINGS WEAKEN/ERASE THE CAP BETWEEN 20-22Z ALONG THE
SFC TROUGH AXIS. TRIGGER WILL BE A STRONG MID LEVEL S/WV PUSHING
INTO WESTERN NORTH DAKOTA NOW...HELPING TO WEAKEN THE STRONG
CAPPING INVERSION CURRENTLY IN PLACE. CONVECTION SHOULD THEN PUSH
EAST THIS EVENING INTO THE OVERNIGHT WITH THE MID LEVEL WAVE AND
SFC TROUGH. STRONG TO SEVERE WEATHER REMAINS IN PLAY WITH THE VERY
STRONG INSTABILITY PRESENT...CURRENTLY 3-6K J/KG. LIMITING FACTOR
WILL BE RATHER WEAK 0-6KM/EFFECTIVE SHEAR UP TO AROUND 20KTS
CURRENTLY IN PLACE AND FORECAST THROUGH THIS EVENING. STILL...WITH
THE AMOUNT OF CAPE PRESENT THERE IS A GOOD PROBABILITY OF LARGE
SEVERE HAIL AND A DAMAGING WIND GUSTS. STORMS WILL BE WATER
LOADED SO WILL LIKELY NEED A RATHER ROBUST/TALL UPDRAFT TO GET THE
LARGE HAIL. IT DOES APPEAR THE MAIN THREAT TODAY INTO THIS EVENING
WILL BE VERY HEAVY RAINFALL ELEVATING THE THREAT FOR FLASH
FLOODING.
CONVECTIVE CHANCES WILL END FROM WEST TO EAST THIS EVENING THROUGH
WEDNESDAY MORNING AS FORCING PUSHES EASTWARD.
OPTED TO KEEP WEDNESDAY AFTERNOON DRY FOR NOW ALONG WITH THE 12Z
GFS/00Z ECMWF. THE 06Z AND 12Z NAM BOTH PAINTED LIGHT DIURNALLY
DRIVEN QPF...SO WILL LET LATER SHIFTS TAKE A LOOK WITH ATTENTION
FOCUSED ON THE NEXT 12 HOURS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 200 PM CDT TUE JUN 25 2013
THE MAIN FEATURE FOR THE EXTENDED PERIOD WILL BE THE INTENSIFYING
UPPER LEVEL RIDGE OVER THE WESTERN US/CANADA AS FORECAST BY THE 12Z
MODEL SUITE. WITH THE RIDGE AXIS POSITIONED OVER THE INTERMOUNTAIN
WEST...NORTH TO NORTHWESTERLY FLOW WILL BE DOMINANT ACROSS NORTH
DAKOTA FOR MUCH OF THE PERIOD. THIS WILL ALLOW FOR SEASONABLE
TEMPERATURES...IN THE 80S TO CONTINUE...KEEPING THE AREA OUT THE
WARMEST H850 TEMPERATURES THAT WILL DEVELOP ACROSS THE WESTERN US.
OVERALL THE FORECAST WILL REMAIN DRY...HOWEVER THERE WILL BE
PERIODIC CHANCES FOR PRECIPITATION FOR PARTS OF CENTRAL AND EASTERN
NORTH DAKOTA...AS A FEW SHORTWAVES ROTATE AROUND THE WESTERN
PERIPHERY OF THE UPPER LEVEL LOW POSITIONED OVER THE GREAT LAKES
REGION. LATE THIS WEEKEND/EARLY NEXT WEEK...SOME UNCERTAINTY IS
INTRODUCED INTO THE FORECAST AS THE THERE IS SOME DISAGREEMENT
AMONGST THE 12Z LONG RANGE MODELS REGARDING THE POTENT SHORTWAVE
THAT IS PROGGED TO DROP SOUTH FROM CANADA AND INTO THE NORTHERN
PLAINS. DUE TO THIS UNCERTAINTY...WILL MAKE NO CHANGES TO THE
ALLBLEND SOLUTION AT THIS TIME SINCE THERE IS NO TARGET OF
OPPORTUNITY TO IMPROVE FORECAST.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 708 PM CDT TUE JUN 25 2013
THUNDERSTORM THREAT HAS ENDED ACROSS ALL BUT KJMS TAF. WILL CARRY
A MENTION OF THUNDER THROUGH AROUND 03Z. OTHERWISE...SOUTHWEST TO
WEST FLOW WILL CONTINUE TO PROGRESS EAST BRINGING AN END TO
THUNDERSTORMS ACROSS EASTERN PORTIONS OF CENTRAL NORTH DAKOTA. VFR
CONDITIONS EXPECTED FOR THE REMAINDER OF TONIGHT AND WEDNESDAY
WITH A WEST TO NORTHWEST FLOW.
&&
.HYDROLOGY...
ISSUED AT 200 PM CDT TUE JUN 25 2013
A FLASH FLOOD WATCH REMAINS IN EFFECT FOR NORTHWEST AND CENTRAL
NORTH DAKOTA THROUGH THIS EVENING. VERY SLOW MOVING THUNDERSTORMS
WITH INTENSE RAINFALL RATES ARE EXPECTED. ONE HOUR FLASH FLOOD
GUIDANCE IS AROUND ONE TO ONE AND A HALF INCHES ACROSS MOST OF THE
WATCH AREA. RAINFALL RATES WITH THUNDERSTORMS TODAY WILL EASILY
SURPASS THIS THRESHOLD...AND WILL HAVE TO CLOSELY MONITOR FOR
FLASH FLOODING THIS AFTERNOON AND EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 1 AM CDT WEDNESDAY FOR NDZ003>005-
011>013-021>023-025-035>037-046>048-050-051.
&&
$$
UPDATE...TWH
LONG TERM...LTH
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
105 AM CDT MON JUN 24 2013
.UPDATE...
ISSUED AT 105 AM CDT MON JUN 24 2013
NO SIGNIFICANT CHANGES WITH THIS FORECAST UPDATE AS THE INHERITED
FORECAST IS WELL ON TRACK. LEFT FOG OUT OF THE FORECAST FOR
NOW...HOWEVER...WILL CONTINUE TO MONITOR THROUGH THE NIGHT WITH
LOW TEMPERATURE-DEW POINT SPREADS ESPECIALLY ACROSS THE NORTH WITH
LIGHT WINDS AND CLEAR SKIES. DID REMOVE THE MENTION OF A SLIGHT
CHANCE OF THUNDERSTORMS ACROSS THE FAR SOUTHWEST LATE TONIGHT WITH
LARGE SCALE SUBSIDENCE AND ONLY WEAK LOW LEVEL WARM AIR ADVECTION.
IN REGARDS TO THE SEVERE THREAT ON MONDAY...SPC IN THEIR DAY ONE
OUTLOOK HAS PLACED THE ENTIRE CWA UNDER A SLIGHT RISK. SEE THE SPC
DAY 1 OUTLOOK FOR DETAILS.
UPDATE ISSUED AT 952 PM CDT SUN JUN 23 2013
WANING CONVECTION OVER NORTHERN FOSTER COUNTY SHOULD QUICKLY
DIMINISH IN THE NEXT HOUR. WILL KEEP A CHANCE POP HERE FOR THE
NEXT HOUR. OTHERWISE...ISOLATED SHOWERS FROM SOUTHERN SASKATCHEWAN
INTO NORTHWEST NORTH DAKOTA CONTINUE TO QUICKLY DIMINISH. WILL NOT
MENTION POPS HERE TONIGHT. OTHERWISE...CURRENT FORECAST IS IN GOOD
SHAPE. DID ADJUST CLOUD COVER LOWER FOR MOST AREAS THIS EVENING
AND WAS A LITTLE SLOWER TO INCREASE CLOUD COVER AFTER MIDNIGHT IN
THE WEST. LATEST 01Z HRRR IS BRINGING SOME LIGHT QPF INTO THE FAR
SOUTHWEST BETWEEN 11Z-12Z MONDAY...SO WILL KEEP A SLIGHT CHANCE OF
CONVECTION IN THE FAR SOUTHWEST TOWARD MORNING.
UPDATE ISSUED AT 703 PM CDT SUN JUN 23 2013
MAIN ISSUE WITH THE EARLY EVENING UPDATE IS CURRENT SHOWER AND
THUNDERSTORM ACTIVITY. CURRENTLY SHOWER AND THUNDERSTORMS WERE
LOCATED FROM JUST NORTH OF GARRISON...TO MINOT...AND THEN
NORTHEAST TO ROLETTE COUNTY. WITH A FEW STRAY SHOWERS EXTENDING
BACK TO NEAR CROSBY. ACTIVITY HAS SHOWN A DECREASE IN INTENSITY
IN THE PAST TWO HOURS. HAVE ADJUSTED POPS A BIT LOWER AND
DECREASED AREAL COVERAGE. EXPECT ACTIVITY TO CONTINUE TO DECREASE
OVER THE NEXT FEW HOURS...AND DISSIPATE COMPLETELY BY AROUND 10 PM.
OTHERWISE NO SIGNIFICANT CHANGES TO THE CURRENT FORECAST.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 345 PM CDT SUN JUN 23 2013
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE SCATTERED
STRONG THUNDERSTORMS NORTH THIS AFTERNOON/EARLY EVENING...FOLLOWED
BY ANOTHER CHANCE OF POSSIBLY STRONG TO SEVERE STORMS MONDAY
AFTERNOON.
CURRENTLY...UPPER LOW OVER CENTRAL SASKATCHEWAN WITH A STRONG
EMBEDDED IMPULSE ROTATING NORTHEAST THROUGH THE DEVILS LAKE BASIN
INTO NORTHEAST NORTH DAKOTA. STEEP LAPSE RATES WITH COLD AIR ALOFT
HAS TRIGGERED A FEW STRONGER STORMS NEAR THE INTERNATIONAL
BORDER. A FEW STRONGER STORMS ARE POSSIBLE AND PERHAPS PULSE
SEVERE WITH MUCAPE 1-2K J/KG. LACK OF SUPPORTIVE 0-6KM SHEAR WILL
LIMIT UPDRAFT LONGEVITY. STORMS ARE DIURNAL IN NATURE AND SHOULD
QUICKLY DISSIPATE INTO EARLY THIS EVENING AS THE NOCTURNAL
INVERSION DEVELOPS. BEFORE THIS HAPPENS...WILL NEED TO MONITOR FOR
POSSIBLE FUNNELS/LAND SPOUTS WITH THE NON-SUPERCELL TOR PARAMETER
ELEVATED OVER NORTHWEST NORTH DAKOTA.
MOSTLY CLEAR THE REMAINDER OF THIS EVENING IN THE WAKE OF THE
CURRENT CONVECTION. MODELS DEVELOP A LOW LEVEL JET LATER THIS
EVENING INTO THE OVERNIGHT ACROSS WESTERN SOUTH DAKOTA NOSING
INTO SOUTHWEST NORTH DAKOTA LATE AROUND OR AFTER 09Z. WILL
INTRODUCE SLIGHT CHANCES FOR THUNDER FAR SOUTHWEST 9-12Z GIVEN
THIS FORCING ALONG WITH INCREASING BOUNDARY LAYER MOISTURE. KEPT
SLIGHT CHANCE POPS GOING THROUGH THE MORNING HOURS WEST.
BOUNDARY LAYER MOISTURE CONTINUES TO ADVECT INTO THE REGION
THROUGHOUT THE DAY MONDAY THANKS TO STRONG MID LEVEL FLOW/MOISTURE
FETCH FROM THE SOUTHERN PLAINS INTO THE DAKOTAS WITH SFC DEWPOINT
TEMPS RISING INTO THE 60S AREA WIDE. THIS WILL CONTRIBUTE TO
INCREASING INSTABILITY WITH MUCAPES PROJECTED TO INCREASING TO
AROUND 2500 J/KG IN THE AFTERNOON AS SFC TEMPS WARM INTO THE
LOW/MID 80S. WHILE A CAPPING INVERSION LOOKS TO BE IN PLACE...A
POTENTIAL TRIGGER VIA A LEAD SHORT WAVE IMPULSE IS FORECAST TO
APPROACH THE DAKOTAS MONDAY AFTERNOON LEADING TO CONVECTIVE
INITIALIZATION. WILL MAINTAIN POPS AS IS FOR NOW DUE TO THE
UNCERTAINTY DURING THE AFTERNOON WHERE AND IF STORMS WILL
DEVELOP.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 345 PM CDT SUN JUN 23 2013
POTENTIAL FOR SEVERE THUNDERSTORMS CONTINUE MONDAY NIGHT AND
TUESDAY. SOUTHWEST FLOW ALOFT TRANSITIONS TO A WESTERLY FLOW
WEDNESDAY...THEN NORTHWEST AS RIDGING DEVELOPS OVER THE FOUR
CORNERS. HOWEVER THE RIDGE FLATTENS SATURDAY AS A SHORTWAVE ROLLS
THROUGH. THIS SHOULD BE TEMPORARY AS THE LONG TERM MODEL SUITE THEN
SHOWS A STRONGER AMPLIFICATION OF THE RIDGE TO COMMENCE ACROSS THE
INTERMOUNTAIN WEST JUST BEYOND THIS EXTENDED PERIOD.
FOR MONDAY NIGHT...WITH STRONG WARM/MOIST AIR ADVECTION IN
THE LOWER LEVELS COMBINED WITH A COUPLE OF SHORTWAVES TRANSVERSING
THROUGH VIA A SOUTHWEST FLOW ALOFT...THIS SHOULD BE ENOUGH TO
PROMOTE CONVECTION THROUGH THE NIGHT. SURFACE DEWPOINTS IN THE UPPER
60S TO AROUND 70 WILL YIELD MUGGY CONDITIONS AND VERY WARM OVERNIGHT
LOWS MONDAY NIGHT. THE STRONGEST SHORTWAVE SHIFTS THROUGH ON TUESDAY
AS A SURFACE COLD FRONT MOVES FROM WEST TO EAST. EXPECTING
THUNDERSTORMS LIKELY ALONG AND AHEAD OF THE FRONT. THE SCENARIO THAT
APPEARS MOST LIKELY IS THUNDERSTORMS WILL BE ONGOING FROM MONDAY
NIGHT AND CONTINUE FOR MOST OF TUESDAY INTO TUESDAY EVENING. THE
COLD FRONT SHOULD CLEAR THE JAMES RIVER VALLEY BY 06Z WEDNESDAY.
WEDNESDAY LOOKS MOSTLY DRY WITH THE EXCEPTION OF NORTH CENTRAL NORTH
DAKOTA WHERE A SHORTWAVE WILL MOVE THROUGH PRODUCING A SLIGHT CHC OF
SHOWERS/THUNDERSTORMS. RIDGING WEST OF NORTH DAKOTA AS MENTIONED
ABOVE WILL PROMOTE DRY WEATHER FOR THURSDAY/FRIDAY...THEN A CHANCE
FOR THUNDERSTORMS SATURDAY THROUGH SUNDAY WITH A SHORTWAVE MOVING
THROUGH.
WARMEST HIGH TEMPERATURES WILL BE TUESDAY WITH MID TO UPPER 80S
ALONG WITH HUMID CONDITIONS. DRIER AIR/LOWER DEWPOINTS CAN BE
EXPECTED FOR THE REST OF THE WEEK WITH HIGHS COOLING TO THE UPPER
70S NORTH AND LOWER 80S SOUTH THURSDAY THROUGH SATURDAY. OVERNIGHT
LOWS IN THE 60S TO NEAR 70 TUESDAY MORNING...THEN UPPER 50S FOR THE
REST OF THE LONG TERM PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 105 AM CDT MON JUN 24 2013
VFR CONDITIONS IN GENERAL ARE EXPECTED ACROSS WESTERN AND CENTRAL
NORTH DAKOTA FOR THE 06 UTC TAF CYCLE. CANNOT RULE OUT PATCHY FOG
LATE TONIGHT...HOWEVER...DUE TO UNCERTAINTY AND LOW
COVERAGE...WILL LEAVE THE MENTION OUT OF THE TAFS FOR NOW. ON
MONDAY THE MAIN THREAT WILL BE THE POTENTIAL FOR SEVERE
THUNDERSTORMS AREA WIDE LATE MONDAY AFTERNOON AND THROUGH THE
EVENING. FOR NOW GIVEN UNCERTAINTY...CODED AS VCTS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...NH
LONG TERM...KS
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1149 PM CDT SUN JUN 23 2013
.UPDATE...
ISSUED AT 1145 PM CDT SUN JUN 23 2013
THE SHOWERS IN THE DVL BASIN HAVE NOW DISSIPATED. REST OF THE
NIGHT WILL BE DRY. KEPT LOWS AS FCST.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 313 PM CDT SUN JUN 23 2013
CONVECTION CHANCES CONTINUE TO BE THE PRIMARY FORECAST PROBLEM FOR
THE PERIOD.
WV LOOP SHOWS THE MAIN SHORTWAVE IS CURRENTLY IN THE PROCESS OF
LIFTING THROUGH THE CWA ON ITS WAY INTO CANADA. THE MAIN SFC LOW
IS ALREADY IN SOUTHERN MANITOBA...WITH ALL BUT THE FAR
NORTHEASTERN CWA SEEING WESTERLY WINDS ON THE SOUTH SIDE OF THE
LOW. THE RAIN BAND FROM THIS MORNING HAS LIFTING NORTH INTO
CANADA...AND SOME CLEARING HAS BEEN GOING ON ALTHOUGH WITH PRETTY
LOW CONVECTIVE TEMPS CU HAS REDEVELOPED RAPIDLY. THERE HAS BEEN A
DECREASE IN MOISTURE AS THE WEST WINDS BRING IN DRIER AIR...BUT
THERE IS STILL A DECENT AMOUNT OF HUMIDITY AND WITH SOME CLEARING
CAPE HAS REACHED AROUND 1000 J/KG ACROSS THE CENTRAL CWA. WHILE
THE BEST LIFT WILL BE QUICKLY MOVING OFF TO THE NORTH THIS
EVENING...THERE IS ENOUGH INSTABILITY HANGING AROUND THAT CANNOT
COMPLETELY RULE OUT THUNDERSTORM REDEVELOPMENT...AND THE RAP AND
HRRR SHOW SIGNS OF THIS ALTHOUGH STRENGTH DOES NOT SEEM IMPRESSIVE
AT THIS POINT. WILL KEEP SOME 30-60 POPS GOING MAINLY NORTH OF THE
HIGHWAY 2 CORRIDOR THROUGH EARLY EVENING BEFORE WE GO DRY AFTER
MIDNIGHT.
MONDAY SHOULD BE FAIRLY QUIET WITH WEAK UPPER RIDGING BETWEEN
SYSTEMS. WINDS WILL SHIFT BACK TO THE SOUTH AS A SFC TROUGH BEGINS
TO DEEPEN OVER THE ROCKIES/WESTERN PLAINS. 850MB TEMPS CLIMB BACK
UP TOWARDS THE UPPER TEENS C AND WITH PLENTY OF SUN WE SHOULD BE
ABLE TO CLIMB INTO THE MID 80S ACROSS MOST OF THE AREA. THE QUIET
CONDITIONS WILL BE SHORT LIVED AS MODELS SHOW SOME INDICATION OF A
WEAK SHORTWAVE MOVING IN MONDAY NIGHT. THINK THERE COULD BE SOME
STORMS MOVING IN FROM THE WEST MONDAY NIGHT...WITH THE MODELS
SHOWING SOME ELEVATED INSTABILITY LIFTING INTO THE CWA OVERNIGHT.
KEPT SOME POPS AROUND 30 PERCENT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 313 PM CDT SUN JUN 23 2013
THINK THAT THE BETTER CHANCES FOR MORE SIGNIFICANT STORMS WILL BE
TUESDAY WHEN A FAIRLY STRONG SHORTWAVE TROUGH MOVES INTO THE
DAKOTAS. THE SFC TROUGH AXIS WILL MOVE INTO CENTRAL ND...WITH
SOUTHEASTERLY WINDS AHEAD OF IT AND GOOD LOW LEVEL CONVERGENCE.
INSTABILITY WILL DEPEND ON EXACTLY ANYTHING OVERNIGHT
EVOLVES...BUT THERE IS THE POSSIBILITY OF MORE THAN 2000 J/KG OF
CAPE. CONTINUED TO KEEP FAIRLY HIGH POPS FOR THUNDERSTORMS TUESDAY
INTO TUESDAY NIGHT...BUT IS A BIT EARLY FOR ANY SEVERE MENTION AT
THIS TIME.
SOME PRECIP MAY LINGER INTO WEDNESDAY MORNING...BUT OVERALL THERE
SHOULD BE A DRYING TREND AS THE UPPER SHORTWAVE PULLS OFF TOWARDS
THE GREAT LAKES. TEMPS SHOULD BE FAIRLY SEASONABLE IN THE LOW 80S.
WEDNESDAY NIGHT TO SATURDAY NIGHT...MODELS IN GOOD AGREEMENT WITH
RETROGRADING AND AMPLIFYING WESTERN CONUS RIDGE AND GREAT LAKES
TROUGH AT 500MB. AS A RESULT NW FLOW ACROSS THE NORTHERN PLAINS
WILL DEVELOP. THIS WILL MAKE FOR SEASONAL END OF JUNE TEMPERATURES
AND NEARLY CLIMO POPS AS THE TIMING OF ANY WEAK SHORT WAVES
FEATURE WILL NEED TO COINCIDE WITH PEAK HEATING TO INITIATE ANY
DIURNALLY DRIVEN CONVECTION AND OVERALL COVERAGE IS EXPECTED TO BE
LOW...THUS THE LOW POPS IN THE EXTENDED.
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1252 PM CDT SUN JUN 23 2013
LOW PRESSURE TRACKING ALMOST DUE NORTH ALONG RED RIVER NEAR HCO WITH
TROUGH AND EDGE OF RAIN NOW THRU TVF. EXPECT MVFR CIGS TO CONTINUE
TO IMPROVE WITH DRIER AIR MIXING IN ON WESTERLY GUSTS 20 TO
30KTS...SOME ISOLATED SHOWERS THIS AFTERNOON POSSIBLE...WITH VFR
CONDITIONS EXPECTED THIS EVENING AND OVERNIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1145 PM CDT SUN JUN 23 2013
LTITLE CHANGE FROM PREV FCST. WINDS DOWN BACKING MORE SOUTH-
SOUTHWEST IN MOST AREAS AND UNDER 10 KTS. IT WILL STAY THIS WAY
TIL JUST PAST SUNRISE. BY 16Z EXPECT WINDS TO TURN A BIT MORE
SOUTHWEST AND SOUNDINGS INDICATE A PRETTY GOOD MIXED LAYER SO
WOULDNT BE SUPRISED TO SEE SOME GUSTS TO 20 KTS OR SO DURING PEAK
HEATING MONDAY. VFR ALL DAY MONDAY WITH A FEW CU OR SOME CIRRUS
MOVING IN. SOME AC MOVING INTO DVL-FAR REGIONS MON EARLY EVE.
COULD BE SOME THUNDER BY 06Z TUE IN DVL-FAR BUT LEFT OUT SINCE
VERY UNCERTAIN.
&&
.HYDROLOGY...
ISSUED AT 628 PM CDT SUN JUN 23 2013
NEW WARNINGS WERE DONE FOR THE BUFFALO RIVER AT SABIN AND DILWORTH
FOR MINOR FLOODING.
NEW WARNINGS ACROSS THE SOUTHERN VALLEY AT HARWOOD...WEST
FARGO... KINDRED...ABERCROMBIE WITH AN INCREASE OF FLOODING TO
MODERATE NOW EXPECTED AT WAHPETON AND FARGO AS THE AREA RIVERS
RESPOND TO LAST NIGHTS RAINFALL OF ONE TO TWO INCHES ON ALREADY
SATURATED SOILS. ALSO...MAPLETON WARNING WAS CANCELLED AS THE
RIVER FELL BELOW FLOOD STAGE EARLIER TODAY.
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...JR
LONG TERM...JR/JK
AVIATION...RIDDLE
HYDROLOGY...WJB/JK
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
611 PM EDT MON JUN 24 2013
.SYNOPSIS...
HIGH PRESSURE OFF THE MIDDLE ATLANTIC COAST WILL CONTINUE TO
BRING A SOUTHERLY FLOW OF WARM AND HUMID AIR TO THE AREA THROUGH
MID WEEK. A WEAK COLD FRONT WILL STALL TO OUR NORTH ACROSS THE
CENTRAL GREAT LAKES TUESDAY. A STRONGER COLD FRONT WILL MOVE
ACROSS THE REGION THURSDAY NIGHT INTO FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
BAND OF AFTERNOON CONVECTION LOST SUPPORT AND DISSIPATED ABOUT
HALFWAY ACROSS THE CWA. AIRMASS REMAINS SOMEWHAT UNSTABLE THE REST
OF THE NIGHT. HRRR AND RUC SHOW SOME OF THE CONVECTION OVER LWR MI
WITH A VERY WEAK S/W WORKING ESE INTO THE LERI AREA THIS EVENING
THEN SOME PART OF THE COMPLEX OVER NW IL MAKING IT AROUND THE LERI
AREA AROUND MIDNIGHT OR SO. WILL KEEP CHANCE POPS GOING BUT TRY AND
DEPICT SOME BETTER TIMING.
LOWS WILL BE ABOVE GUIDANCE BY A DEGREE OR TWO.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/...
NEW DAY...SAME CONCERNS. UPPER FLOW IS NOW FAIRLY ZONAL THANKS TO
THE FLATTENING RIDGE. MODELS SHOW AN UPPER TROF DEVELOPING TO OUR
WEST BY WEDNESDAY AND THEN MOVING INTO THE REGION THURSDAY. IT
THEN GETS TRAPPED IN THE AREA AND THEN REINFORCED FOR THE WEEKEND
BUT THAT WILL BE COVERED IN THE SECTION BELOW. FOR TUESDAY MODELS
SHOW CONTINUED DEEP MOISTURE ACROSS THE AREA WITH WEAK
DISTURBANCES ALOFT MOVING THROUGH THE AREA. EXPECTING MORE
COVERAGE THAN TODAY AND WILL HAVE LIKELY TO HIGH CHANCE ACROSS THE
NORTHERN TIER OF COUNTIES WITH 30-40% SOUTH. TUESDAY NIGHT INTO
WEDNESDAY MODELS SHOW THICKNESS PACKING NORTHWEST TO SOUTHEAST
ACROSS THE AREA WITH THE LIKELY GENERATION POINT FOR MCS
DEVELOPMENT TO OUR NORTHWEST. CONCERNED THAT WE HAVE CONVECTION
MOVE INTO THE AREA TUESDAY NIGHT FROM THE NORTHWEST LASTING INTO
WEDNESDAY. WILL HAVE LIKELY POPS NORTHWEST PA AND NERN OHIO AND
MID/HIGH CHANCE ELSEWHERE TUESDAY NIGHT AND EARLY WEDNESDAY. LAKE
WEDNESDAY WILL HAVE LIKELY POPS MOVING IN FROM THE NORTHWEST WITH
APPROACHING UPPER TROF. THURSDAY AN UPPER TROF REMAINS OVER THE
AREA WITH DEEP MOISTURE STILL IN PLACE SO WILL CONTINUE LIKELY
POPS CENTRAL AND EAST WITH CHANCE POPS WEST. TEMPS WELL ABOVE
NORMAL THROUGH MID WEEK AND THEN NEAR NORMAL THURSDAY.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
UPPER LEVEL TROUGH DIGS INTO THE CENTRAL GREAT LAKES ON FRIDAY THEN
AMPLIFIES AS IT SLOWLY PIVOTS EAST OVER THE WEEKEND. THIS WILL CAUSE
LOW PRESSURE AT THE SURFACE TO RETROGRADE TO THE WEST WITH A
CONTINUED CHANCE OF SHOWERS AND THUNDERSTORMS WITHIN THE BROAD
CYCLONIC FLOW THROUGH AT LEAST SATURDAY. WILL CARRY A 30-50 PERCENT
POP FOR FRIDAY AND SATURDAY WITH A DECREASING TREND FOR SUNDAY AS
DRIER AIR GETS WRAPPED INTO THE SYSTEM FROM THE WEST. HIGHS WILL BE
NEAR NORMAL ON FRIDAY...AROUND 80...BEFORE DROPPING BACK INTO THE
70S OVER THE WEEKEND. ADJUSTED HIGHS DOWN SEVERAL DEGREES FOR
SATURDAY/SUNDAY CLOSER TO RAW MODEL VALUES INSTEAD OF MEX GUIDANCE
WHICH IS LIKELY RUNNING TOO HIGH AS IT TRENDS TOWARDS CLIMO IN THE
LATER PERIODS.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
SCATTERED THUNDERSTORMS HAVE DEVELOPED ALONG A BOUNDARY EXTENDING
FROM NEAR DETROIT TO WEST OF MANSFIELD AND COLUMBUS. THESE
THUNDERSTORMS ARE MOVING NORTHEAST AT APPROXIMATELY 20 MPH AND HAVE
TRIED TO TIME INTO THE TERMINALS BETWEEN 18-00Z EXCEPT FDY/ERI WHERE
CHANCES LOOK TO0 LOW. ANY THUNDERSTORM THAT REACHES A TERMINAL MAY
PRODUCE BRIEF HEAVY RAIN AND WIND GUSTS UP TO 35 KNOTS. VFR
CONDITIONS EXPECTED TO PERSIST OUTSIDE OF THUNDERSTORMS. TRYING TO
TIME ANY ADDITIONAL SHOWERS AND THUNDERSTORMS FOR LATER IN THE TAF
PERIOD IS DIFFICULT AND WILL DEPEND ON LEFT OVER BOUNDARIES AND
EVOLUTION OF UPSTREAM ACTIVITY. MODELS SUGGEST ANOTHER ROUND OF
SHOWERS AND SCATTERED THUNDERSTORMS MAY TRY TO MOVE SOUTHEAST OUT OF
MICHIGAN EARLY TUESDAY MORNING AND ADDED SHOWERS INTO THE MORE
FAVORED LOCATIONS. ALSO INCLUDED MVFR HZ/BR AT A FEW SITES BETWEEN
10-13Z GIVEN THE HIGH HUMIDITY.
.OUTLOOK...NON-VFR IN SCATTERED SHOWERS/THUNDERSTORMS AND EARLY
MORNING MIST/HAZE THROUGH SATURDAY.
&&
.MARINE...
SOUTHWEST FLOW WILL CONTINUE ON THE LAKE AHEAD OF LOW PRESSURE THAT
WILL EVENTUALLY APPROACH LATE WEDNESDAY FROM THE PLAINS. SPEEDS WILL
INCREASE TO 10-20 KNOTS FOR A PERIOD OF TIME BEFORE SLOWLY VEERING
TO THE NORTHWEST THURSDAY AND FRIDAY AS THE LOW SHIFTS TO THE
EASTERN GREAT LAKES.
TIMING OF THUNDERSTORMS WILL BE DIFFICULT OVER THE NEXT SEVERAL DAYS
WITH MULTIPLE ROUNDS OF CONVECTION EXPECTED...ESPECIALLY FROM
TUESDAY THROUGH THURSDAY. THUNDERSTORMS HAVE THE POTENTIAL TO BE
STRONG GIVEN THE HOT AND HUMID AIRMASS OVER THE REGION.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK/ADAMS
SHORT TERM...TK
LONG TERM...KEC
AVIATION...KEC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
324 PM EDT MON JUN 24 2013
.SYNOPSIS...
DISTURBANCES EMBEDDED IN ZONAL FLOW WILL CONTINUE TO INTERACT WITH
A WARM AND UNSTABLE AIRMASS TO BRING CHANCES FOR SHOWERS AND
THUNDERSTORMS TO THE AREA THROUGH MID WEEK. AN APPROACHING COLD
FRONT WILL BRING INCREASING CHANCES FOR PRECIPITATION STARTING
WEDNESDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
ZONAL FLOW HAS DEVELOPED ALOFT ACROSS THE OHIO VALLEY TODAY. A
WEAKENING COMPLEX OVERNIGHT ASSOCIATED WITH A DISTURBANCE EMBEDDED
IN THE ZONAL FLOW BROUGHT A CONVERGENT LOW LEVEL BOUNDARY TO THE
AREA LATE THIS MORNING AND HAS BEEN THE FOCUS FOR SHOWERS AND
THUNDERSTORMS THIS AFTERNOON. THIS ACTIVITY WILL CONTINUE EASTWARD
AND APPEARS THAT IT WILL REACH THE EASTERN EDGE OF THE FORECAST
AREA BY THIS EVENING. A LOT OF UNCERTAINTY IS LEFT BEHIND THIS
DEPARTING BAND OF CONVECTION...WITH SKIES CLEARING ACROSS THE
NORTHWESTERN HALF OF OF THE ILN AREA THIS AFTERNOON. A DECAYING
MCV ACROSS NORTHERN INDIANA MAY ACT AS A FOCUS FOR ADDITIONAL
CONVECTION ACROSS NORTHERN INDIANA LATE THIS AFTERNOON...AS THE
ATMOSPHERE DESTABILIZES IN THE WAKE OF THIS MORNINGS CLOUD COVER.
LAPS SOUNDINGS SHOW UP TO 3000 J/KG SFC BASED CAPE JUST TO THE
WEST OF OUR NORTHWESTERN ZONES...WITH THE RAP INDICATING THAT
DESTABILIZATION WILL CONTINUE INTO THE AFTERNOON AND EARLY
EVENING. THE BIG QUESTION BECOMES HOW MUCH FORCING WILL THERE BE
FROM THE DECAYING MCV...IF ANY...TO PRODUCE CONVECTION LATE THIS
AFTERNOON. WITH THIS UNCERTAINTY IN MIND...AM FORECASTING CHANCE
POPS TO MOVE INTO OUR NORTHWESTERN ZONES LATE THIS AFTERNOON AND
EVENING...IN CASE THIS CONVECTION DOES INITIATE.
ANY CONVECTION THAT DOES DEVELOP WILL LIKELY DIMINISH AROUND
SUNSET AS LOW LEVEL FLOW REMAINS WEAK ACROSS OUR AREA...NOT
SUPPORTIVE OF NOCTURNAL CONVECTION. SOME CONVECTION WILL PROBABLY
REMAIN ONGOING TO OUR NORTH AND NORTHWEST TONIGHT...WHERE LOW TO
MID LEVEL FLOW IS STRONGER.
TONIGHT WILL BE ANOTHER WARM ONE WITH THE WARM AND HUMID AIRMASS
IN PLACE. WENT JUST BELOW GUIDANCE BASED ON BIASES FOR THE PAST
COUPLE OF NIGHTS...WITH SOME A WARM BIAS IN THE MODELS BEING
NOTICED IN OUR TYPICALLY COOLER VALLEYS.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
ANOTHER DISTURBANCE WILL FOLLOW IN THE WAKE OF TODAYS DISTURBANCE
ON TUESDAY. LATEST RAP/NAM/ARW INDICATE THIS DISTURBANCE WILL BE
CROSSING SOUTHERN LAKE MICHIGAN EARLY TUESDAY. THE QUESTION
IS HOW ARE MODELS HANDLING SOME WARMER AIR ALOFT MOVING INTO
THE REGION...AND ITS AFFECT ON A DEVELOPING A CAP ACROSS OUR AREA
TUESDAY. MOST MODELS ARE INDICATING A WEAK CAP AROUND 5 KFT AGL
BASICALLY SOUTH OF INTERSTATE 70 ON TUESDAY...WHICH WOULD LIMIT
AND CONVECTION FROM INITIATING AS THE DISTURBANCE PASSES TO OUR
NORTH TUESDAY AFTERNOON. THE NAM/SREF DO NOT BUY INTO THIS
SOLUTION...AND HAVE A MUCH WEAKER...AND BREAKABLE CAP IN PLACE.
BASED ON THE INHERENT UNCERTAINTIES IN THIS CURRENT CONVECTIVE
REGIME...AND THE FACT THAT A GOOD DEAL OF LOW LEVEL MOISTURE IS IN
PLACE...CANNOT RULE OUT CONVECTION IN THE SOUTH TUESDAY. WENT WITH
CHANCE POPS FOR ALL ZONES WITH 30 POPS IN THE SOUTH AND 40 POPS
MAINLY NORTH OF INTERSTATE 70. HIGH TEMPERATURES...BARRING ANY
DEBRIS CLOUDS TO START OFF WITH...WILL RISE INTO THE UPPER 80S TO
LOWER 90S DURING THE AFTERNOON.
UNCERTAINTY INCREASES EVEN FURTHER GOING INTO TUESDAY NIGHT...WITH
ADDITIONAL CONVECTION POSSIBLE MAINLY ACROSS THE NORTH AS UPPER
LEVEL ENERGY IMPULSES CONTINUE TO MOVE WEST TO EAST IN THE ZONAL
FLOW. KEPT POPS IN THE SLIGHT CHANCE TO CHANCE RANGE FOR NOW...IN
CASE SOME OF THIS CONVECTION MAKES IT INTO OUR FORECAST AREA
DURING THE OVERNIGHT TIME PERIOD. ANOTHER WARM NIGHT WILL RESULT
WITH THE CONTINUED WARM AIRMASS. AM ANTICIPATING ENHANCED CLOUD COVER
TUESDAY NIGHT WITH SOME CONVECTION TO OUR NORTH...AND POSSIBLE
RETURN FLOW CONTINUING INTO THE NIGHT. TEMPERATURES MAY ONLY
BOTTOM OUT IN THE LOWER 70S ACROSS MANY OF OUR ZONES...EXCEPT FOR
PERHAPS THE RURAL EASTERN ZONES.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
THERE ARE SOME MODEL DISCREPANCIES AS TO HOW MUCH IF ANY PCPN WILL
BE ONGOING WEDNESDAY MORNING. WILL TREND TOWARD A DRIER FORECAST AT
THE ONSET BUT HANG ON TO SOME LOWER POPS JUST TO COVER THE THREAT.
ASSUMING THERE ARE NOT TOO MANY LINGERING DEBRIS CLOUDS...WE SHOULD
THEN BE ABLE TO DESTABILIZE NICELY THROUGH THE AFTERNOON IF
TEMPERATURES CAN PUSH INTO THE UPPER 80S TO NEAR 90. THIS WOULD
RESULT IN ML CAPE VALUES IN THE 2000 TO POSSIBLY 3000 J/KG RANGE.
THE COMBINATION OF THIS AND SHORT WAVE ENERGY MOVING DOWN ACROSS THE
WESTERN GREAT LAKES INTO OUR AREA WEDNESDAY AFTERNOON INTO WEDNESDAY
NIGHT...SHOULD LEAD TO A DECENT CHANCE OF THUNDERSTORMS PUSHING IN
FROM THE NORTHWEST LATE IN THE DAY. WITH INCREASING DYNAMICS ACROSS
THE AREA AND FAVORABLE TIMING...THERE IS THE POSSIBILITY OF SOME
SEVERE STORMS...ESPECIALLY LATE WEDNESDAY AFTERNOON INTO WEDNESDAY
EVENING. PCPN CHANCES WILL THEN CONTINUE INTO THURSDAY AS THE COLD
FRONT MOVES THROUGH. HIGHEST POPS FOR THURSDAY WILL BE ACROSS OUR
EAST/SOUTHEAST...CLOSER TO THE UPPER LEVEL TROUGH AND WHERE THE COLD
FRONT WILL BE LAST TO MOVE THROUGH.
BUILDING RIDGE OVER THE WESTERN UNITED STATES WILL CONTINUE TO
CARVE OUT A TROUGH ACROSS THE EAST THROUGH THE REMAINDER OF THE LONG
TERM PERIOD. THIS WILL KEEP TEMPERATURES FAIRLY SEASONABLE FRIDAY
THROUGH MONDAY WITH HIGHS GENERALLY IN THE LOWER 80S. MODELS ARE
SHOWING VARIOUS WEAK SHORT WAVES PROGRESSING THROUGH THE TROUGH BUT
IT IS TOUGH TO PINPOINT ANY KIND OF TIMING. AS A RESULT...WITH THE
UPPER LEVEL TROUGH IN PLACE AND GIVEN THE TIME OF YEAR...THINK THE
BEST WAY TO GO IS TO TREND THE POPS DIURNAL BUT KEEP THEM ON THE LOW
SIDE THROUGH THE WEEKEND.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
CONVECTION WILL AFFECT TAF SITES THIS AFTERNOON INTO THIS EVENING.
IT APPEARS THAT CMH AND LCK WILL SEE A CLUSTER OF THUNDERSTORMS
EARLY THIS AFTERNOON. OTHER CONVECTION AIDED BY AN UPPER AIR
TROUGH MAY DEVELOP AND IMPACT OTHER TAF SITES...WHICH WILL THEN
DIE DOWN WITH LOSS OF DAYTIME HEATING. BR IS EXPECTED LATE TONIGHT
AT LUK AND ILN. LACK OF UPPER SUPPORT MAY LIMIT CONVECTIVE
FORMATION ON TUESDAY.
OUTLOOK...SHOWERS AND THUNDERSTORMS WILL OCCUR FROM WEDNESDAY
AFTERNOON THROUGH THURSDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...LATTO
NEAR TERM...LATTO
SHORT TERM...LATTO
LONG TERM...JGL
AVIATION...CONIGLIO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1156 PM EDT TUE JUN 25 2013
.SYNOPSIS...
AN EARLY SEASON BERMUDA HIGH WILL CONTINUE TO BRING VERY WARM AND
HUMID WEATHER TO CENTRAL PENNSYLVANIA THROUGH THURSDAY...ACCOMPANIED
BY A FEW ROUNDS OF MAINLY AFTERNOON AND EVENING THUNDERSTORMS. THE
UPPER LEVEL PATTERN ACROSS THE LOWER 48 WILL TRANSITION TO AN
AMPLIFIED WESTERN RIDGE/EASTERN TROUGH CONFIGURATION...RESULTING IN
SLIGHTLY COOLER TEMPERATURES WITH A PROLONGED PERIOD OF UNSETTLED
WEATHER THROUGH THE END OF JUNE.
&&
.NEAR TERM /UNTIL 8 AM WEDNESDAY MORNING/...
MIDNIGHT UPDATE...
HAVE CHOSEN TO KILL THE SVR WATCH AS MOST OF THE WATCH AREA IS
STABLE AND THE STORMS TO THE WEST DO NOT LOOK STRONG ENOUGH TO
MAKE A WIDESPREAD THREAT FOR ELEVATED SVR CONVECTION - WHICH IS A
RARE EVENT IN AND OF ITSELF.
THE THREAT NOW WILL BE HEAVY RAIN - THANKFULLY THE HEAVIEST RAIN
FROM EARLIER THIS EVENING WAS ACROSS CLEARFILED AND CENTRE
COUNTIES. THIS AREA LOOKS TO BE JUST NORTH OF WHERE THE CURRENT
CONVECTION IS HEADED - THE SW AND SC MTS. WILL MENTION HEAVY RAIN
THREAT IN WX GRIDS AND HWO. BUT RAINFALL THERE IN THE PAST 12 HRS
HAS BEEN GENERALY TWO TENTHS OF AN INCH OR LESS.
PREV FCST...
LARGE AND LONG-LIVED DERECHO NOW GONE FROM THE CWA. WIDESPREAD
DAMAGE IN THE FORM OF STRIGHT LINE WINDS HAS BEEN REPORTED ACROSS
ALL OF CWA S OF I-80 AND IN WARREN CO WHERE IT ALL BEGAN.
ADDITIONAL CONVECTION ROUGHLY ASSOCD WITH DECELERATION/NOSE OF
LLVL JET CONTINUES TO FIRE LIKE A BAD RASH OVER WRN PA AND ERN OH.
WILL HOLD ONTO WESTERN HALF OF SVR WW365 FOR THE REMAINDER OF THE
TIME...BUT LLVS VERY COOL NOW AND MOST LIKELY STABLE. THUS...MOST
OF THE CONVECTION WILL STAY ELEVATED. THIS MEANS THERE IS LESS OF
A THREAT OF WIND DAMAGE...BUT STILL SOME THREAT - ESP WITH THE
CURRENT APPEARANCE OF THE STORMS IN PBZ AREA RIGHT NOW. WILL
FOLLOW HRRR OUTPUT FOR POPS AND WX THRU THE OVERNIGHT AS IT HAS
BEEN DOING VERY VERY WELL TODAY AND SEEMS TO HAVE A MUCH BETTER
HANDLE ON CURR CONV THAN RUC AND NEW NAM.
&&
.SHORT TERM /8 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
A MORE PRONOUNCED SHORTWAVE TROUGH SHOULD CREST THE RETROGRADING
UPPER RIDGE OVER THE NRN PLAINS WITH STRONGER HGT FALLS SPREADING
SEWD FM THE UPPER MIDWEST INTO THE GRT LKS/OH VLY ON DAY 2.
AT THE SFC...A DEVELOPING SFC LOW AND TRAILING COLD FRONT WILL
FOLLOW A SIMILAR TRACK AND REACH THE UPPER OH VLY BY 27/12Z.
MULTIPLE TSTM CLUSTERS SHOULD DEVELOP FROM THE OHIO VALLEY...EAST
INTO THE REGION WEDNESDAY AFTERNOON AND NIGHT...ALONG LINGERING
OUTFLOW BOUNDARIES.
THE STORMS SHOULD CONTINUE TO INCREASE IN COVERAGE AND ADVECT EAST
OR NORTHEAST LATE WED/WED NIGHT AS THE NOSE OF A SWLY LLJ BEGINS TO
MOVE INTO THE REGION AND UPPER DIFLUENCE INCREASES AHEAD OF THE OHIO
VALLEY SHORTWAVE.
THE DAY 2 SLGT RISK WAS RECENTLY EXPANDED AT 17Z TO ENCOMPASS ALL OF
THE CWA AS A RESULT OF INCREASING SPEED AND DIRECTIONAL SHEAR WITHIN
THE VERY WARM/UNSTABLE AIRMASS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
ANY CONVECTION COULD LINGER INTO WEDNESDAY EVENING. HOWEVER...THE
BY THURSDAY/DAY 3...THE UPPER ANTICYCLONE WILL EXPAND NWD OVER
THE FOUR CORNERS AND INTER- MTN WEST AS A LARGE SCALE DEEPENING
TROUGH ESTABLISHES ITSELF ACRS THE ERN U.S. THE DAY 2 SHORTWAVE
TROUGH SHOULD CONTINUE TO PRESS EWD INTO THE MID- ATLC/NERN STATES
ALONG WITH THE ACCOMPANYING FRONTAL SYSTEM. PER SPC DAY 3
OUTLOOK...THE FOCUS FOR POTENTIAL SVR STORMS WILL SHIFT EWD INTO
THE SERN 1/2 OF THE CWA WHERE INSTABILITY/CYCLONIC MID- LVL FLOW
WILL LKLY BE MAXIMIZED IN ADVANCE OF UPPER TROUGH/SFC COLD FRONT.
THIS AREA IS HIGHLIGHTED BY A CATEGORICAL SLGT RISK AND WILL
INCLUDE MENTION IN THE HWO. OVERALL...EXPECT INCREASINGLY
UNSETTLED CONDS WITH DAYTIME TEMPS FALLING BACK CLOSER TO LATE-
JUNE NORMALS.
THE 25/12Z GLOBAL NUMERICAL MODEL AND ENSEMBLE GUIDANCE ARE IN
EXCELLENT AGREEMENT CONCERNING THE LARGE SCALE PATTERN THROUGH THE
MEDIUM RANGE AND EXTENDED FCST PERIOD...MAINTAINING A TROUGH OFF
THE WEST COAST...RIDGE OVER THE WEST AND DOWNSTREAM TROUGH IN THE
EAST. THIS PATTERN SHOWS NO SIGNS OF BREAKING DOWN ANYTIME SOON
AND COULD PERSIST ALL THE WAY TO THE 4TH OF JULY.
THE SLIGHTLY COOLER AND INCREASINGLY UNSETTLED SENSIBLE WEATHER
TREND INITIATING FROM THE MID-LATE WEEK PERIOD IS EXPECTED TO
CONTINUE THROUGH DAYS 4-7 AND LKLY INTO EARLY JULY...AS THE
NEARLY STATIONARY UPPER TROUGH AND ASSOCD COLD FRONT COMBINE TO
MAINTAIN ACTIVE WEATHER. THE PATTERN LOOKS FAVORABLE FOR HEAVY
RAIN WITH A PLUME OF DEEP TROPICAL MSTR/ATM RIVER BEING CHANNELED
NWD FROM THE CARIBBEAN INTO THE SERN US AND MID-ATLC STATES. WITH
THE ODDS TILTING TOWARD AN ABNORMALLY WET PERIOD..INCREASED POPS
ABOVE CLIMO FOR SEVERAL PERIODS IN-LINE WITH THE ECMWF-BASED MOS
GUID.
&&
.AVIATION /04Z WEDNESDAY THROUGH SUNDAY/...
MAIN LINE OF STORMS THAT PRODUCED STRONG WINDS AND DANGEROUS
LIGHTNING HAS JUST CLEARED THE LNS AREA.
WATCHING ANOTHER AREA OF STORMS OVER SW PA...EXPECT THESE
TO SLOWLY WEAKEN...BUT AREAS LIKE AOO...JST...WILL LIKELY
SEE SOME MORE HEAVY RAIN AND THUNDER...EVEN SOME INTO UNV...
GIVEN TYPE OF AIRMASS JUST ABOVE THE SFC.
FURTEHR EAST...EXPECT IPT...MDT...AND LNS TO PERHAPS SEE
A FEW MORE SHOWERS.
FOR WED MORNING...NEW MODELS HINT THAT RAIN WITH THE BACK
SIDE OF THE STORMS WILL BE A LITTLE FURTHER SOUTH. WILL
CONTINUE TO ADJUST FCST.
FOR WED AFT...WILL LEAVE STORMS OUT FOR NOW...ACTION WILL
LIKELY MAINLY AFT 00Z.
OUTLOOK...
THU...AREAS OF AM MVFR FOG/HAZE POSS. NUMEROUS SHOWERS
AND THUNDERSTORMS.
FRI-SUN...MORE ORGANIZED SHOWERS/TSRA FRIDAY THROUGH
SUNDAY...ESPECIALLY ACROSS THE EASTERN HALF OF THE STATE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT/STEINBUGL
NEAR TERM...DANGELO
SHORT TERM...LAMBERT/STEINBUGL
LONG TERM...CERU/STEINBUGL
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1147 PM EDT TUE JUN 25 2013
.SYNOPSIS...
AN EARLY SEASON BERMUDA HIGH WILL CONTINUE TO BRING VERY WARM AND
HUMID WEATHER TO CENTRAL PENNSYLVANIA THROUGH THURSDAY...ACCOMPANIED
BY A FEW ROUNDS OF MAINLY AFTERNOON AND EVENING THUNDERSTORMS. THE
UPPER LEVEL PATTERN ACROSS THE LOWER 48 WILL TRANSITION TO AN
AMPLIFIED WESTERN RIDGE/EASTERN TROUGH CONFIGURATION...RESULTING IN
SLIGHTLY COOLER TEMPERATURES WITH A PROLONGED PERIOD OF UNSETTLED
WEATHER THROUGH THE END OF JUNE.
&&
.NEAR TERM /UNTIL 7 AM WEDNESDAY MORNING/...
LARGE AND LONG-LIVED DERECHO NOW GONE FROM THE CWA. WIDESPREAD
DAMAGE IN THE FORM OF STRIGHT LINE WINDS HAS BEEN REPORTED ACROSS
ALL OF CWA S OF I-80 AND IN WARREN CO WHERE IT ALL BEGAN. ADDITIONAL
CONVECTION ROUGHLY ASSOCD WITH DECELERATION/NOSE OF LLVL JET
CONTINUES TO FIRE LIKE A BAD RASH OVER WRN PA AND ERN OH. WILL
HOLD ONTO WESTERN HALF OF SVR WW365 FOR THE REMAINDER OF THE
TIME...BUT LLVS VERY COOL NOW AND MOST LIKELY STABLE. THUS...MOST
OF THE CONVECTION WILL STAY ELEVATED. THIS MEANS THERE IS LESS OF
A THREAT OF WIND DAMAGE...BUT STILL SOME THREAT - ESP WITH THE
CURRENT APPEARANCE OF THE STORMS IN PBZ AREA RIGHT NOW. WILL
FOLLOW HRRR OUTPUT FOR POPS AND WX THRU THE OVERNIGHT AS IT HAS
BEEN DOING VERY VERY WELL TODAY AND SEEMS TO HAVE A MUCH BETTER
HANDLE ON CURR CONV THAN RUC AND NEW NAM.
&&
.SHORT TERM /7 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
A MORE PRONOUNCED SHORTWAVE TROUGH SHOULD CREST THE RETROGRADING
UPPER RIDGE OVER THE NRN PLAINS WITH STRONGER HGT FALLS SPREADING
SEWD FM THE UPPER MIDWEST INTO THE GRT LKS/OH VLY ON DAY 2.
AT THE SFC...A DEVELOPING SFC LOW AND TRAILING COLD FRONT WILL
FOLLOW A SIMILAR TRACK AND REACH THE UPPER OH VLY BY 27/12Z.
MULTIPLE TSTM CLUSTERS SHOULD DEVELOP FROM THE OHIO VALLEY...EAST
INTO THE REGION WEDNESDAY AFTERNOON AND NIGHT...ALONG LINGERING
OUTFLOW BOUNDARIES.
THE STORMS SHOULD CONTINUE TO INCREASE IN COVERAGE AND ADVECT EAST
OR NORTHEAST LATE WED/WED NIGHT AS THE NOSE OF A SWLY LLJ BEGINS TO
MOVE INTO THE REGION AND UPPER DIFLUENCE INCREASES AHEAD OF THE OHIO
VALLEY SHORTWAVE.
THE DAY 2 SLGT RISK WAS RECENTLY EXPANDED AT 17Z TO ENCOMPASS ALL OF
THE CWA AS A RESULT OF INCREASING SPEED AND DIRECTIONAL SHEAR WITHIN
THE VERY WARM/UNSTABLE AIRMASS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
ANY CONVECTION COULD LINGER INTO WEDNESDAY EVENING. HOWEVER...THE
BY THURSDAY/DAY 3...THE UPPER ANTICYCLONE WILL EXPAND NWD OVER
THE FOUR CORNERS AND INTER- MTN WEST AS A LARGE SCALE DEEPENING
TROUGH ESTABLISHES ITSELF ACRS THE ERN U.S. THE DAY 2 SHORTWAVE
TROUGH SHOULD CONTINUE TO PRESS EWD INTO THE MID- ATLC/NERN STATES
ALONG WITH THE ACCOMPANYING FRONTAL SYSTEM. PER SPC DAY 3
OUTLOOK...THE FOCUS FOR POTENTIAL SVR STORMS WILL SHIFT EWD INTO
THE SERN 1/2 OF THE CWA WHERE INSTABILITY/CYCLONIC MID- LVL FLOW
WILL LKLY BE MAXIMIZED IN ADVANCE OF UPPER TROUGH/SFC COLD FRONT.
THIS AREA IS HIGHLIGHTED BY A CATEGORICAL SLGT RISK AND WILL
INCLUDE MENTION IN THE HWO. OVERALL...EXPECT INCREASINGLY
UNSETTLED CONDS WITH DAYTIME TEMPS FALLING BACK CLOSER TO LATE-
JUNE NORMALS.
THE 25/12Z GLOBAL NUMERICAL MODEL AND ENSEMBLE GUIDANCE ARE IN
EXCELLENT AGREEMENT CONCERNING THE LARGE SCALE PATTERN THROUGH THE
MEDIUM RANGE AND EXTENDED FCST PERIOD...MAINTAINING A TROUGH OFF
THE WEST COAST...RIDGE OVER THE WEST AND DOWNSTREAM TROUGH IN THE
EAST. THIS PATTERN SHOWS NO SIGNS OF BREAKING DOWN ANYTIME SOON
AND COULD PERSIST ALL THE WAY TO THE 4TH OF JULY.
THE SLIGHTLY COOLER AND INCREASINGLY UNSETTLED SENSIBLE WEATHER
TREND INITIATING FROM THE MID-LATE WEEK PERIOD IS EXPECTED TO
CONTINUE THROUGH DAYS 4-7 AND LKLY INTO EARLY JULY...AS THE
NEARLY STATIONARY UPPER TROUGH AND ASSOCD COLD FRONT COMBINE TO
MAINTAIN ACTIVE WEATHER. THE PATTERN LOOKS FAVORABLE FOR HEAVY
RAIN WITH A PLUME OF DEEP TROPICAL MSTR/ATM RIVER BEING CHANNELED
NWD FROM THE CARIBBEAN INTO THE SERN US AND MID-ATLC STATES. WITH
THE ODDS TILTING TOWARD AN ABNORMALLY WET PERIOD..INCREASED POPS
ABOVE CLIMO FOR SEVERAL PERIODS IN-LINE WITH THE ECMWF-BASED MOS
GUID.
&&
.AVIATION /04Z WEDNESDAY THROUGH SUNDAY/...
MAIN LINE OF STORMS THAT PRODUCED STRONG WINDS AND DANGEROUS
LIGHTNING HAS JUST CLEARED THE LNS AREA.
WATCHING ANOTHER AREA OF STORMS OVER SW PA...EXPECT THESE
TO SLOWLY WEAKEN...BUT AREAS LIKE AOO...JST...WILL LIKELY
SEE SOME MORE HEAVY RAIN AND THUNDER...EVEN SOME INTO UNV...
GIVEN TYPE OF AIRMASS JUST ABOVE THE SFC.
FURTEHR EAST...EXPECT IPT...MDT...AND LNS TO PERHAPS SEE
A FEW MORE SHOWERS.
FOR WED MORNING...NEW MODELS HINT THAT RAIN WITH THE BACK
SIDE OF THE STORMS WILL BE A LITTLE FURTHER SOUTH. WILL
CONTINUE TO ADJUST FCST.
FOR WED AFT...WILL LEAVE STORMS OUT FOR NOW...ACTION WILL
LIKELY MAINLY AFT 00Z.
OUTLOOK...
THU...AREAS OF AM MVFR FOG/HAZE POSS. NUMEROUS SHOWERS
AND THUNDERSTORMS.
FRI-SUN...MORE ORGANIZED SHOWERS/TSRA FRIDAY THROUGH
SUNDAY...ESPECIALLY ACROSS THE EASTERN HALF OF THE STATE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT/STEINBUGL
NEAR TERM...DANGELO
SHORT TERM...LAMBERT/STEINBUGL
LONG TERM...CERU/STEINBUGL
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1052 PM EDT TUE JUN 25 2013
.SYNOPSIS...
AN EARLY SEASON BERMUDA HIGH WILL CONTINUE TO BRING VERY WARM AND
HUMID WEATHER TO CENTRAL PENNSYLVANIA THROUGH THURSDAY...ACCOMPANIED
BY A FEW ROUNDS OF MAINLY AFTERNOON AND EVENING THUNDERSTORMS. THE
UPPER LEVEL PATTERN ACROSS THE LOWER 48 WILL TRANSITION TO AN
AMPLIFIED WESTERN RIDGE/EASTERN TROUGH CONFIGURATION...RESULTING IN
SLIGHTLY COOLER TEMPERATURES WITH A PROLONGED PERIOD OF UNSETTLED
WEATHER THROUGH THE END OF JUNE.
&&
.NEAR TERM /UNTIL 7 AM WEDNESDAY MORNING/...
LARGE AND LONG-LIVED DERECHO NOW GONE FROM THE CWA. WIDESPREAD
DAMAGE IN THE FORM OF STRIGHT LINE WINDS HAS BEEN REPORTED ACROSS
ALL OF CWA S OF I-80 AND IN WARREN CO WHERE IT ALL BEGAN. ADDITIONAL
CONVECTION ROUGHLY ASSOCD WITH DECELERATION/NOSE OF LLVL JET
CONTINUES TO FIRE LIKE A BAD RASH OVER WRN PA AND ERN OH. WILL
HOLD ONTO WESTERN HALF OF SVR WW365 FOR THE REMAINDER OF THE
TIME...BUT LLVS VERY COOL NOW AND MOST LIKELY STABLE. THUS...MOST
OF THE CONVECTION WILL STAY ELEVATED. THIS MEANS THERE IS LESS OF
A THREAT OF WIND DAMAGE...BUT STILL SOME THREAT - ESP WITH THE
CURRENT APPEARANCE OF THE STORMS IN PBZ AREA RIGHT NOW. WILL
FOLLOW HRRR OUTPUT FOR POPS AND WX THRU THE OVERNIGHT AS IT HAS
BEEN DOING VERY VERY WELL TODAY AND SEEMS TO HAVE A MUCH BETTER
HANDLE ON CURR CONV THAN RUC AND NEW NAM.
&&
.SHORT TERM /7 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
A MORE PRONOUNCED SHORTWAVE TROUGH SHOULD CREST THE RETROGRADING
UPPER RIDGE OVER THE NRN PLAINS WITH STRONGER HGT FALLS SPREADING
SEWD FM THE UPPER MIDWEST INTO THE GRT LKS/OH VLY ON DAY 2.
AT THE SFC...A DEVELOPING SFC LOW AND TRAILING COLD FRONT WILL
FOLLOW A SIMILAR TRACK AND REACH THE UPPER OH VLY BY 27/12Z.
MULTIPLE TSTM CLUSTERS SHOULD DEVELOP FROM THE OHIO VALLEY...EAST
INTO THE REGION WEDNESDAY AFTERNOON AND NIGHT...ALONG LINGERING
OUTFLOW BOUNDARIES.
THE STORMS SHOULD CONTINUE TO INCREASE IN COVERAGE AND ADVECT EAST
OR NORTHEAST LATE WED/WED NIGHT AS THE NOSE OF A SWLY LLJ BEGINS TO
MOVE INTO THE REGION AND UPPER DIFLUENCE INCREASES AHEAD OF THE OHIO
VALLEY SHORTWAVE.
THE DAY 2 SLGT RISK WAS RECENTLY EXPANDED AT 17Z TO ENCOMPASS ALL OF
THE CWA AS A RESULT OF INCREASING SPEED AND DIRECTIONAL SHEAR WITHIN
THE VERY WARM/UNSTABLE AIRMASS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
ANY CONVECTION COULD LINGER INTO WEDNESDAY EVENING. HOWEVER...THE
BY THURSDAY/DAY 3...THE UPPER ANTICYCLONE WILL EXPAND NWD OVER
THE FOUR CORNERS AND INTER- MTN WEST AS A LARGE SCALE DEEPENING
TROUGH ESTABLISHES ITSELF ACRS THE ERN U.S. THE DAY 2 SHORTWAVE
TROUGH SHOULD CONTINUE TO PRESS EWD INTO THE MID- ATLC/NERN STATES
ALONG WITH THE ACCOMPANYING FRONTAL SYSTEM. PER SPC DAY 3
OUTLOOK...THE FOCUS FOR POTENTIAL SVR STORMS WILL SHIFT EWD INTO
THE SERN 1/2 OF THE CWA WHERE INSTABILITY/CYCLONIC MID- LVL FLOW
WILL LKLY BE MAXIMIZED IN ADVANCE OF UPPER TROUGH/SFC COLD FRONT.
THIS AREA IS HIGHLIGHTED BY A CATEGORICAL SLGT RISK AND WILL
INCLUDE MENTION IN THE HWO. OVERALL...EXPECT INCREASINGLY
UNSETTLED CONDS WITH DAYTIME TEMPS FALLING BACK CLOSER TO LATE-
JUNE NORMALS.
THE 25/12Z GLOBAL NUMERICAL MODEL AND ENSEMBLE GUIDANCE ARE IN
EXCELLENT AGREEMENT CONCERNING THE LARGE SCALE PATTERN THROUGH THE
MEDIUM RANGE AND EXTENDED FCST PERIOD...MAINTAINING A TROUGH OFF
THE WEST COAST...RIDGE OVER THE WEST AND DOWNSTREAM TROUGH IN THE
EAST. THIS PATTERN SHOWS NO SIGNS OF BREAKING DOWN ANYTIME SOON
AND COULD PERSIST ALL THE WAY TO THE 4TH OF JULY.
THE SLIGHTLY COOLER AND INCREASINGLY UNSETTLED SENSIBLE WEATHER
TREND INITIATING FROM THE MID-LATE WEEK PERIOD IS EXPECTED TO
CONTINUE THROUGH DAYS 4-7 AND LKLY INTO EARLY JULY...AS THE
NEARLY STATIONARY UPPER TROUGH AND ASSOCD COLD FRONT COMBINE TO
MAINTAIN ACTIVE WEATHER. THE PATTERN LOOKS FAVORABLE FOR HEAVY
RAIN WITH A PLUME OF DEEP TROPICAL MSTR/ATM RIVER BEING CHANNELED
NWD FROM THE CARIBBEAN INTO THE SERN US AND MID-ATLC STATES. WITH
THE ODDS TILTING TOWARD AN ABNORMALLY WET PERIOD..INCREASED POPS
ABOVE CLIMO FOR SEVERAL PERIODS IN-LINE WITH THE ECMWF-BASED MOS
GUID.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
FAST MOVING SQUALL LINE DROPPING SE WITH STRONG WINDS
AND DANGEROUS LIGHTNING. HAVE ADJUSTED 00Z TAFS FOR THIS.
WATCHING MORE STORMS OVER OH...JUST SOUTH OF CLE.
WILL CONTINUE TO ADJUST AS NEEDED.
OUTLOOK...
THU...AREAS OF AM MVFR FOG/HAZE POSS. NUMEROUS SHOWERS
AND THUNDERSTORMS.
FRI-SUN...MORE ORGANIZED SHOWERS/TSRA FRIDAY THROUGH
SUNDAY...ESPECIALLY ACROSS THE EASTERN HALF OF THE STATE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT/STEINBUGL
NEAR TERM...DANGELO
SHORT TERM...LAMBERT/STEINBUGL
LONG TERM...CERU/STEINBUGL
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
704 PM EDT MON JUN 24 2013
.SYNOPSIS...
A BERMUDA HIGH WILL REMAIN IN PLACE OFF THE ATLANTIC COAST THROUGH
THE WEEK...DRIVING PERSISTENT MOIST SOUTHERLY FLOW INTO THE REGION.
AFTERNOON SHOWERS AND THUNDERSTORMS WILL REMAIN A POSSIBILITY EACH
DAY. A COLD FRONT PASSAGE OVER THE WEEKEND WILL BRING AN INCREASE IN
RAIN CHANCES AND SLIGHTLY COOLER TEMPERATURES BEFORE CLEARING THE
AREA EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 700 PM EDT MONDAY...OUTFLOW BNDRYS ARE WORKING INTO THE
UPSTATE AND NE GA FROM THE SOUTH...TRIGGERING SOME CONVECTION IN
THEIR WAKE. THERE IS ALSO SOME ACTIVITY ALONG THE BLUE
RIDGE...ESPECIALLY UP IN NORTH CAROLINA. I TRIMMED POPS BACK ACROSS
THE WRN NC PIEDMONT AND THE ERN FOOTHILLS AND THE NE PIEDMONT OF
SOUTH CAROLINA. SINCE THESE AREAS WERE WORKED OVER BY CONVECTION
THEY SHOULD ENJOY A QUIET EVENING. HOWEVER...LATER TONIGHT WE MAY
SEE CONVECTION DEVELOP ONCE AGAIN AS THE SEA BREEZE FRONT PUSHES IN
FROM THE SOUTH BETWEEN ABOUT MIDNIGHT AND 2 AM. LAST NIGHT THIS
HELPED TO KICK OFF SHOWERS AND STORMS...AND IF SOMETHING DOESN/T
WORK OVER THE SRN PART OF THE SC/GA PARTS OF THE FA...I/D EXPECT TO
SEE SOMETHING LIKE THAT AGAIN.
AS OF 435 PM EDT MONDAY...STRONG TO SEVERE STORMS ARE CONTINUING
ALONG THE I-40 CORRIDOR OF NORTH CAROLINA. OVER THE UPSTATE..NE GA
AND MOST OF THE NC MTNS ITS GENERALLY QUIET RIGHT NOW. HOWEVER...THE
AIRMASS IS QUITE UNSTABLE OVER THIS AREA AND AS OUTFLOW BNDRYS WORK
IN FROM THE SOUTH AND WEST WE SHOULD SEE MORE DEVELOPMENT INTO THE
EARLY EVENING HOURS. THEREFORE I HAVE POPS RAMPING BACK UP INTO THE
THE HIGH CHANCE RANGE IN A COUPLE HOURS.
AS OF 225 PM EDT...COVERAGE OF SHOWERS AND THUNDERSTORMS REMAINS
FAIRLY HIGH ACROSS THE ERN HALF OF THE CWFA IN THE LOWER 70S
DEWPOINT AIR EAST OF THE MOUNTAINS. WITH SFC BASED CAPE VALUES IN
THE 2000 TO 3000 J/KG RANGE ACROSS MUCH OF THE REGION...ANTICIPATE
ADDITIONAL DEVELOPMENT ON EARLIER OUTFLOWS...AND NEW DEVELOPMENT
ACROSS THE MOUNTAINS IN WEAK BL CONVERGENCE AND LIGHT SW UPSLOPE. A
FEW SEVERE STORMS REMAIN POSSIBLE GIVEN THE INSTABILITY...BUT DCAPE
VALUES ARE GENERALLY 900 J/KG OR LESS AND PROFILES FAIRLY MOIST...SO
IT WILL TAKE VERY TALL STORMS. WILL FEATURE MAINLY SOLID CHC TO LOW
LIKELY POPS FOR THE LATE AFTN HOURS...EXCEPT CATEGORICAL ON THE ERN
FRINGE.
UPPER FORCING WILL SLOWLY IMPROVE THROUGH THE PERIOD AS H5
TROUGHINESS CONTINUES ALONG THE SRN APPALACHIANS...WITH WEAK UPPER
DIVERGENCE SETTING UP OVER THE MTNS THROUGH TUE. LOW LEVEL SW FLOW
SHOULD PROVIDE SOME UPSLOPE ENHANCEMENT IN THE SW MTNS WHERE CHC
POPS WILL BE KEPT GOING THE LONGEST TONIGHT. SIGNALS ARE MIXED ON
LOW STRATUS DEVELOPMENT TUE MORNING GIVEN A MORE SW TO W DIRECTION
IN THE BL FLOW VERSUS THE SRLY WINDS OBSERVED THIS MORNING. EXPECT
MIN TEMPS TO BE QUITE WARM. THE UPPER FORCING...PWAT IN PROFILES
AROUND 1.75 INCHES...AND A DEVELOPING LEE TROUGH SHOULD GET LIKELY
COVERAGE GOING AGAIN EARLY ON TUESDAY...WITH SIMILAR HAZARDS OF
LOCALLY HEAVY RAINFALL AND AN ISOLD SEVERE THREAT. THICKNESSES
SUPPORT VERY WARM TEMPS NEAR 90 TUE AFTN IN THE PIEDMONT...BUT CLOUD
COVER AND PRECIP SHOULD CURB THAT SOMEWHAT.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 230 PM MONDAY...THE SHORT TERM PERIOD LOOKS RATHER
ACTIVE...HIGHLIGHTED BY A SERIES OF UPPER LEVEL IMPULSES AIDING IN
DIURNAL CONVECTION...AND AN UPPER TROF DIVING THROUGH THE OHIO
VALLEY THROUGH THE END OF THE PERIOD. TUESDAY EVENING A PERSISTENT
BERMUDA HIGH WILL CONTINUE TO PROMOTE SOUTHERLY FLOW. MID TO UPPER
60S DEWPOINTS AND SURFACE TEMPERATURES IN THE 80S WILL CONTINUE TO
ALLOW FOR ENOUGH INSTABILITY FOR CONVECTION INTO THE EVENING HOURS.
THUS...KEPT SOLID CHANCE POPS THROUGH SUNSET. MEANWHILE...UPPER
LEVEL PATTERN BEGINS TO AMPLIFY SOMEWHAT AS TROF DEEPENS ACROSS THE
UPPER MIDWEST. AS THE DISTURBANCE MOVES EASTWARD THROUGH THE
GREAT LAKES REGION ON WEDNESDAY...HEIGHTS ACROSS NORTHEAST GEORGIA
AND THE CAROLINAS WILL BEGIN TO FALL. AS FLOW AT THE SURFACE
REMAINS SOUTHERLY...AND HEIGHTS FALL ALOFT...EXPECTING SOME RATHER
WIDESPREAD CONVECTION TO OCCUR WEDNESDAY AFTERNOON. BOTH GFS AND
NAM FORECAST SOUNDINGS INDICATE SUBSTANTIAL DRYING IN THE MID LEVELS
INTO THE AFTERNOON HOURS THUS STEEPENING LAPSE RATES.
LIKEWISE...SBCAPE VALUES NEARING 1500-2000J/KG CANNOT BE RULED
OUT...ESPECIALLY ACROSS THE HIGHER TERRAIN AND THE UPSTATE OF SC.
KEPT HIGH END CHANCE POPS ACROSS THE ENTIRE REGION WITH SLIGHTLY
HIGHER POPS OVER THE ABOVE MENTIONED AREAS. WITH ALL THAT
SAID...SHEAR PROFILES LOOK RATHER BLEAK AS FLOW THROUGH THE COLUMN
IS WEAK. THUS NOT EXPECTING ANY ROTATING STORMS...LEADING TO A MORE
DAMAGING WIND...LARGE HAIL...AND HEAVY RAINFALL THREAT. MOST IF NOT
ALL CONVECTION SHOULD CEASE BY NEAR OR SLIGHTLY AFTER SUNSET ON
WEDNESDAY EVENING AS DIURNAL HEATING IS LOST. TEMPERATURES WILL BE
SLIGHTLY ABOVE NORMAL FOR MOST AREAS ON WEDNESDAY.
AS THE UPPER TROF DIGS OUT ACROSS THE OHIO AND TENNESSEE RIVER
VALLEYS ON THURSDAY...UPPER LEVEL HEIGHTS WILL FALL FURTHER...AND A
SURFACE COLD FRONT WILL BE MOVING CLOSER TO THE REGION. EXPECTING
MUCH OF THE SAME ON THURSDAY AS SURFACE HEATING AND MODEST DEWPOINTS
WILL ALLOW FOR SUBSTANTIAL CAPE. HOWEVER ALTHOUGH NOT THAT
HIGH...THURSDAY WILL YIELD MORE SHEAR THAN WEDNESDAY AS THE TROF
BASE SWINGS THROUGH...AND THE COLD FRONT APPROACHES. THIS WILL LEAD
TO AT LEAST SOME POTENTIAL FOR BETTER CONVECTIVE ORGANIZATION. LOOK
FOR THE MAIN THREATS ON THURSDAY TO BE DAMAGING WINDS...LARGE
HAIL...AND HEAVY RAINFALL. CONVECTION WILL LIKELY BE MOST INTENSE
ALONG AND AHEAD OF THE FRONT DURING THE AFTERNOON HOURS. WENT WITH
LIKELY POPS EARLY IN THE DAY ACROSS THE HIGHER TERRAIN AND SOLID
CHANCE POPS ELSEWHERE. TEMPERATURES ON THURSDAY WILL BE AT OR
SLIGHTLY BELOW NORMAL AS THUNDERSTORM DEVELOPMENT WILL PLAY A MAJOR
ROLE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 200 PM MONDAY...THE EXTENDED PERIOD BEGINS WITH THE CWA ON THE
FAR WESTERN PERIPHERY OF A BERMUDA HIGH AND AN UPPER LEVEL TROUGH
QUICKLY DEVELOPING OVER THE REGION ON THURSDAY. THE TROUGH DEEPENS
OVER THE WEEKEND AND TAKES OVER THE MAJORITY OF THE EASTERN
CONUS...WHILE A COLD FRONT APPROACHES WITH THE TROUGH AND THEN
STALLS OUT OVER THE AREA FOR THE WEEKEND. THE TROUGH REMAINS THE
DOMINANT FEATURE FOR MOST OF THE EXTENDED PERIOD...WITH HIGH
PRESSURE ONLY BEGINNING TO BUILD BACK IN TO THE WEST OF THE FORECAST
AREA BY EARLY NEXT WEEK. CONVECTION WILL BE MAINLY DIURNAL IN
NATURE...WITH ISOLATED TO SCATTERED COVERAGE OVER THE FOOTHILLS AND
MOUNTAINS EACH AFTERNOON. THE HIGHEST POPS WILL BE FEATURED EARLY IN
THE WEEKEND WITH THE FRONTAL PASSAGE. CLOUD COVER AND THE PERSISTENT
UPPER TROUGH WILL KEEP HIGH TEMPERATURES SLIGHTLY COOLER THAN
AVERAGE OVER THE WEEKEND...BUT NORTHWESTERLY FLOW FOLLOWING THE
FRONT WILL DRY OUT THE AIRMASS AND ALLOW A SLIGHT WARMING TREND BY
LATE WEEKEND/EARLY NEXT WEEK.
&&
.AVIATION /23Z MONDAY THROUGH SATURDAY/...
AT KCLT...THE TRAINING CLUSTER OF THUNDERSTORMS HAS SET UP MAINLY S
TO SE OF THE AIRFIELD THIS AFTN...BUT CLOSE ENOUGH TO CARRY WALL TO
WALL THUNDER THROUGH 00Z...WITH TEMPO GUSTS AND MVFR RESTRICTIONS IN
ANY HEAVIER RAINFALL. WE COULD SEE ADDITIONAL DEVELOPMENT FROM THE
FOOTHILLS LATER THIS AFTN/EVENING PER THE LATEST HRRR RUN.
CONFIDENCE IS LOWER ON THAT...SO WILL RAMP DOWN TO A VCSH FOR NOW.
CIGS AND VSBY ARE A REAL QUESTION MARK OVERNIGHT...WITH SOME STRATUS
LIKELY IN THE LOWER PIEDMONT...BUT WITH SW TO W BL FLOW PROVIDING
MUCH LESS OF A PUSH INTO THE TERMINAL AREA. WILL HINT THAT WAY WITH
SCT010 BUT KEEP CIGS AND VSBY VFR FOR NOW. EXPECT AN EARLY START TO
CONVECTION AGAIN ON TUE WITH VERY MOIST PROFILES AND SLIGHTLY
IMPROVING UPPER SUPPORT.
ELSEWHERE...THUNDERSTORMS ARE LIKELY AT TIMES AT ALL THE MTN AND
FOOTHILLS TAF LOCATIONS THIS AFTN AND EVENING. WILL RIDE ON SOME
FAIRLY BROAD VCTS GROUPS FOR NOW...BUT TEMPO WILL LIKELY BE NEEDED
AT TIMES LATER ON. EXPECT MAINLY VFR CIGS EXCEPT BRIEF MVFR IN ANY
TSTMS ALONG WITH BRIEFLY GUSTY WINDS. SCT SHRA OR TSRA COULD
CONTINUE INTO THE OVERNIGHT HOURS...BUT WITH THE BEST FOCUS IN SW
MTN UPSLOPE AREAS...SO WILL ALLOW COVERAGE TO WANE FOR NOW. MTN
VALLEY FOG/CIG PROBLEMS LOOK LIKELY...WITH IFR AT KAVL BY 08Z. EAST
OF THE MTNS...CONFIDENCE IS LOWER GIVEN THE SW TO W BL FLOW. SOME
STRATUS SEEMS LIKELY TOWARD DAYBREAK...AND POSSIBLY VSBY ISSUES IF
THE TERMINALS SEE HEAVY RAINFALL LATE TODAY. EXPECT ANOTHER EARLY
START TO CONVECTION ON TUE WITH THE AIRMASS REMAINING VERY MOIST.
OUTLOOK...EXPECT UNSETTLED WEATHER AT THE TERMINAL LOCATIONS THROUGH
THE WEEK...WITH UPPER TROUGHINESS PERSISTING AND THEN DEEPENING MID
TO LATE WEEK. THIS SHOULD LEAD TO MORNING FOG/STRATUS
RESTRICTIONS...WITH MAINLY AFTN/EVENING TSRA EACH DAY.
CONFIDENCE TABLE...
23-05Z 05-11Z 11-17Z 17-23Z
KCLT HIGH 100% HIGH 98% HIGH 86% MED 60%
KGSP HIGH 100% HIGH 97% HIGH 100% HIGH 80%
KAVL HIGH 100% MED 65% MED 66% MED 75%
KHKY HIGH 100% HIGH 98% HIGH 95% HIGH 100%
KGMU HIGH 100% HIGH 97% HIGH 98% HIGH 80%
KAND HIGH 100% HIGH 100% HIGH 90% HIGH 80%
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...VISIN
NEAR TERM...HG/MCAVOY
SHORT TERM...CDG
LONG TERM...VISIN
AVIATION...HG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
509 PM EDT MON JUN 24 2013
.SYNOPSIS...
A BERMUDA HIGH WILL REMAIN IN PLACE OFF THE ATLANTIC COAST THROUGH
THE WEEK...DRIVING PERSISTENT MOIST SOUTHERLY FLOW INTO THE REGION.
AFTERNOON SHOWERS AND THUNDERSTORMS WILL REMAIN A POSSIBILITY EACH
DAY. A COLD FRONT PASSAGE OVER THE WEEKEND WILL BRING AN INCREASE IN
RAIN CHANCES AND SLIGHTLY COOLER TEMPERATURES BEFORE CLEARING THE
AREA EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 435 PM EDT MONDAY...STRONG TO SEVERE STORMS ARE CONTINUING
ALONG THE I-40 CORRIDOR OF NORTH CAROLINA. OVER THE UPSTATE..NE GA
AND MOST OF THE NC MTNS ITS GENERALLY QUIET RIGHT NOW. HOWEVER...THE
AIRMASS IS QUITE UNSTABLE OVER THIS AREA AND AS OUTFLOW BNDRYS WORK
IN FROM THE SOUTH AND WEST WE SHOULD SEE MORE DEVELOPMENT INTO THE
EARLY EVENING HOURS. THEREFORE I HAVE POPS RAMPING BACK UP INTO THE
THE HIGH CHANCE RANGE IN A COUPLE HOURS.
AS OF 225 PM EDT...COVERAGE OF SHOWERS AND THUNDERSTORMS REMAINS
FAIRLY HIGH ACROSS THE ERN HALF OF THE CWFA IN THE LOWER 70S
DEWPOINT AIR EAST OF THE MOUNTAINS. WITH SFC BASED CAPE VALUES IN
THE 2000 TO 3000 J/KG RANGE ACROSS MUCH OF THE REGION...ANTICIPATE
ADDITIONAL DEVELOPMENT ON EARLIER OUTFLOWS...AND NEW DEVELOPMENT
ACROSS THE MOUNTAINS IN WEAK BL CONVERGENCE AND LIGHT SW UPSLOPE. A
FEW SEVERE STORMS REMAIN POSSIBLE GIVEN THE INSTABILITY...BUT DCAPE
VALUES ARE GENERALLY 900 J/KG OR LESS AND PROFILES FAIRLY MOIST...SO
IT WILL TAKE VERY TALL STORMS. WILL FEATURE MAINLY SOLID CHC TO LOW
LIKELY POPS FOR THE LATE AFTN HOURS...EXCEPT CATEGORICAL ON THE ERN
FRINGE.
UPPER FORCING WILL SLOWLY IMPROVE THROUGH THE PERIOD AS H5
TROUGHINESS CONTINUES ALONG THE SRN APPALACHIANS...WITH WEAK UPPER
DIVERGENCE SETTING UP OVER THE MTNS THROUGH TUE. LOW LEVEL SW FLOW
SHOULD PROVIDE SOME UPSLOPE ENHANCEMENT IN THE SW MTNS WHERE CHC
POPS WILL BE KEPT GOING THE LONGEST TONIGHT. SIGNALS ARE MIXED ON
LOW STRATUS DEVELOPMENT TUE MORNING GIVEN A MORE SW TO W DIRECTION
IN THE BL FLOW VERSUS THE SRLY WINDS OBSERVED THIS MORNING. EXPECT
MIN TEMPS TO BE QUITE WARM. THE UPPER FORCING...PWAT IN PROFILES
AROUND 1.75 INCHES...AND A DEVELOPING LEE TROUGH SHOULD GET LIKELY
COVERAGE GOING AGAIN EARLY ON TUESDAY...WITH SIMILAR HAZARDS OF
LOCALLY HEAVY RAINFALL AND AN ISOLD SEVERE THREAT. THICKNESSES
SUPPORT VERY WARM TEMPS NEAR 90 TUE AFTN IN THE PIEDMONT...BUT CLOUD
COVER AND PRECIP SHOULD CURB THAT SOMEWHAT.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 230 PM MONDAY...THE SHORT TERM PERIOD LOOKS RATHER
ACTIVE...HIGHLIGHTED BY A SERIES OF UPPER LEVEL IMPULSES AIDING IN
DIURNAL CONVECTION...AND AN UPPER TROF DIVING THROUGH THE OHIO
VALLEY THROUGH THE END OF THE PERIOD. TUESDAY EVENING A PERSISTENT
BERMUDA HIGH WILL CONTINUE TO PROMOTE SOUTHERLY FLOW. MID TO UPPER
60S DEWPOINTS AND SURFACE TEMPERATURES IN THE 80S WILL CONTINUE TO
ALLOW FOR ENOUGH INSTABILITY FOR CONVECTION INTO THE EVENING HOURS.
THUS...KEPT SOLID CHANCE POPS THROUGH SUNSET. MEANWHILE...UPPER
LEVEL PATTERN BEGINS TO AMPLIFY SOMEWHAT AS TROF DEEPENS ACROSS THE
UPPER MIDWEST. AS THE DISTURBANCE MOVES EASTWARD THROUGH THE
GREAT LAKES REGION ON WEDNESDAY...HEIGHTS ACROSS NORTHEAST GEORGIA
AND THE CAROLINAS WILL BEGIN TO FALL. AS FLOW AT THE SURFACE
REMAINS SOUTHERLY...AND HEIGHTS FALL ALOFT...EXPECTING SOME RATHER
WIDESPREAD CONVECTION TO OCCUR WEDNESDAY AFTERNOON. BOTH GFS AND
NAM FORECAST SOUNDINGS INDICATE SUBSTANTIAL DRYING IN THE MID LEVELS
INTO THE AFTERNOON HOURS THUS STEEPENING LAPSE RATES.
LIKEWISE...SBCAPE VALUES NEARING 1500-2000J/KG CANNOT BE RULED
OUT...ESPECIALLY ACROSS THE HIGHER TERRAIN AND THE UPSTATE OF SC.
KEPT HIGH END CHANCE POPS ACROSS THE ENTIRE REGION WITH SLIGHTLY
HIGHER POPS OVER THE ABOVE MENTIONED AREAS. WITH ALL THAT
SAID...SHEAR PROFILES LOOK RATHER BLEAK AS FLOW THROUGH THE COLUMN
IS WEAK. THUS NOT EXPECTING ANY ROTATING STORMS...LEADING TO A MORE
DAMAGING WIND...LARGE HAIL...AND HEAVY RAINFALL THREAT. MOST IF NOT
ALL CONVECTION SHOULD CEASE BY NEAR OR SLIGHTLY AFTER SUNSET ON
WEDNESDAY EVENING AS DIURNAL HEATING IS LOST. TEMPERATURES WILL BE
SLIGHTLY ABOVE NORMAL FOR MOST AREAS ON WEDNESDAY.
AS THE UPPER TROF DIGS OUT ACROSS THE OHIO AND TENNESSEE RIVER
VALLEYS ON THURSDAY...UPPER LEVEL HEIGHTS WILL FALL FURTHER...AND A
SURFACE COLD FRONT WILL BE MOVING CLOSER TO THE REGION. EXPECTING
MUCH OF THE SAME ON THURSDAY AS SURFACE HEATING AND MODEST DEWPOINTS
WILL ALLOW FOR SUBSTANTIAL CAPE. HOWEVER ALTHOUGH NOT THAT
HIGH...THURSDAY WILL YIELD MORE SHEAR THAN WEDNESDAY AS THE TROF
BASE SWINGS THROUGH...AND THE COLD FRONT APPROACHES. THIS WILL LEAD
TO AT LEAST SOME POTENTIAL FOR BETTER CONVECTIVE ORGANIZATION. LOOK
FOR THE MAIN THREATS ON THURSDAY TO BE DAMAGING WINDS...LARGE
HAIL...AND HEAVY RAINFALL. CONVECTION WILL LIKELY BE MOST INTENSE
ALONG AND AHEAD OF THE FRONT DURING THE AFTERNOON HOURS. WENT WITH
LIKELY POPS EARLY IN THE DAY ACROSS THE HIGHER TERRAIN AND SOLID
CHANCE POPS ELSEWHERE. TEMPERATURES ON THURSDAY WILL BE AT OR
SLIGHTLY BELOW NORMAL AS THUNDERSTORM DEVELOPMENT WILL PLAY A MAJOR
ROLE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 200 PM MONDAY...THE EXTENDED PERIOD BEGINS WITH THE CWA ON THE
FAR WESTERN PERIPHERY OF A BERMUDA HIGH AND AN UPPER LEVEL TROUGH
QUICKLY DEVELOPING OVER THE REGION ON THURSDAY. THE TROUGH DEEPENS
OVER THE WEEKEND AND TAKES OVER THE MAJORITY OF THE EASTERN
CONUS...WHILE A COLD FRONT APPROACHES WITH THE TROUGH AND THEN
STALLS OUT OVER THE AREA FOR THE WEEKEND. THE TROUGH REMAINS THE
DOMINANT FEATURE FOR MOST OF THE EXTENDED PERIOD...WITH HIGH
PRESSURE ONLY BEGINNING TO BUILD BACK IN TO THE WEST OF THE FORECAST
AREA BY EARLY NEXT WEEK. CONVECTION WILL BE MAINLY DIURNAL IN
NATURE...WITH ISOLATED TO SCATTERED COVERAGE OVER THE FOOTHILLS AND
MOUNTAINS EACH AFTERNOON. THE HIGHEST POPS WILL BE FEATURED EARLY IN
THE WEEKEND WITH THE FRONTAL PASSAGE. CLOUD COVER AND THE PERSISTENT
UPPER TROUGH WILL KEEP HIGH TEMPERATURES SLIGHTLY COOLER THAN
AVERAGE OVER THE WEEKEND...BUT NORTHWESTERLY FLOW FOLLOWING THE
FRONT WILL DRY OUT THE AIRMASS AND ALLOW A SLIGHT WARMING TREND BY
LATE WEEKEND/EARLY NEXT WEEK.
&&
.AVIATION /21Z MONDAY THROUGH SATURDAY/...
AT KCLT...THE TRAINING CLUSTER OF THUNDERSTORMS HAS SET UP MAINLY S
TO SE OF THE AIRFIELD THIS AFTN...BUT CLOSE ENOUGH TO CARRY WALL TO
WALL THUNDER THROUGH 00Z...WITH TEMPO GUSTS AND MVFR RESTRICTIONS IN
ANY HEAVIER RAINFALL. WE COULD SEE ADDITIONAL DEVELOPMENT FROM THE
FOOTHILLS LATER THIS AFTN/EVENING PER THE LATEST HRRR RUN.
CONFIDENCE IS LOWER ON THAT...SO WILL RAMP DOWN TO A VCSH FOR NOW.
CIGS AND VSBY ARE A REAL QUESTION MARK OVERNIGHT...WITH SOME STRATUS
LIKELY IN THE LOWER PIEDMONT...BUT WITH SW TO W BL FLOW PROVIDING
MUCH LESS OF A PUSH INTO THE TERMINAL AREA. WILL HINT THAT WAY WITH
SCT010 BUT KEEP CIGS AND VSBY VFR FOR NOW. EXPECT AN EARLY START TO
CONVECTION AGAIN ON TUE WITH VERY MOIST PROFILES AND SLIGHTLY
IMPROVING UPPER SUPPORT.
ELSEWHERE...THUNDERSTORMS ARE LIKELY AT TIMES AT ALL THE MTN AND
FOOTHILLS TAF LOCATIONS THIS AFTN AND EVENING. WILL RIDE ON SOME
FAIRLY BROAD VCTS GROUPS FOR NOW...BUT TEMPO WILL LIKELY BE NEEDED
AT TIMES LATER ON. EXPECT MAINLY VFR CIGS EXCEPT BRIEF MVFR IN ANY
TSTMS ALONG WITH BRIEFLY GUSTY WINDS. SCT SHRA OR TSRA COULD
CONTINUE INTO THE OVERNIGHT HOURS...BUT WITH THE BEST FOCUS IN SW
MTN UPSLOPE AREAS...SO WILL ALLOW COVERAGE TO WANE FOR NOW. MTN
VALLEY FOG/CIG PROBLEMS LOOK LIKELY...WITH IFR AT KAVL BY 08Z. EAST
OF THE MTNS...CONFIDENCE IS LOWER GIVEN THE SW TO W BL FLOW. SOME
STRATUS SEEMS LIKELY TOWARD DAYBREAK...AND POSSIBLY VSBY ISSUES IF
THE TERMINALS SEE HEAVY RAINFALL LATE TODAY. EXPECT ANOTHER EARLY
START TO CONVECTION ON TUE WITH THE AIRMASS REMAINING VERY MOIST.
OUTLOOK...EXPECT UNSETTLED WEATHER AT THE TERMINAL LOCATIONS THROUGH
THE WEEK...WITH UPPER TROUGHINESS PERSISTING AND THEN DEEPENING MID
TO LATE WEEK. THIS SHOULD LEAD TO MORNING FOG/STRATUS
RESTRICTIONS...WITH MAINLY AFTN/EVENING TSRA EACH DAY.
CONFIDENCE TABLE...
20-02Z 02-08Z 08-14Z 14-20Z
KCLT HIGH 100% HIGH 100% HIGH 100% MED 79%
KGSP HIGH 100% HIGH 100% HIGH 99% HIGH 91%
KAVL HIGH 100% HIGH 81% MED 66% MED 69%
KHKY HIGH 100% HIGH 100% HIGH 85% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 99% HIGH 91%
KAND HIGH 100% HIGH 100% HIGH 94% HIGH 93%
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...VISIN
NEAR TERM...HG/MCAVOY
SHORT TERM...CDG
LONG TERM...VISIN
AVIATION...HG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
237 PM EDT MON JUN 24 2013
.SYNOPSIS...
A BERMUDA HIGH WILL REMAIN IN PLACE OFF THE ATLANTIC COAST THROUGH
THE WEEK...DRIVING PERSISTENT MOIST SOUTHERLY FLOW INTO THE REGION.
AFTERNOON SHOWERS AND THUNDERSTORMS WILL REMAIN A POSSIBILITY EACH
DAY. A COLD FRONT PASSAGE OVER THE WEEKEND WILL BRING AN INCREASE IN
RAIN CHANCES AND SLIGHTLY COOLER TEMPERATURES BEFORE CLEARING THE
AREA EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 225 PM EDT...COVERAGE OF SHOWERS AND THUNDERSTORMS REMAINS
FAIRLY HIGH ACROSS THE ERN HALF OF THE CWFA IN THE LOWER 70S
DEWPOINT AIR EAST OF THE MOUNTAINS. WITH SFC BASED CAPE VALUES IN
THE 2000 TO 3000 J/KG RANGE ACROSS MUCH OF THE REGION...ANTICIPATE
ADDITIONAL DEVELOPMENT ON EARLIER OUTFLOWS...AND NEW DEVELOPMENT
ACROSS THE MOUNTAINS IN WEAK BL CONVERGENCE AND LIGHT SW UPSLOPE. A
FEW SEVERE STORMS REMAIN POSSIBLE GIVEN THE INSTABILITY...BUT DCAPE
VALUES ARE GENERALLY 900 J/KG OR LESS AND PROFILES FAIRLY MOIST...SO
IT WILL TAKE VERY TALL STORMS. WILL FEATURE MAINLY SOLID CHC TO LOW
LIKELY POPS FOR THE LATE AFTN HOURS...EXCEPT CATEGORICAL ON THE ERN
FRINGE.
UPPER FORCING WILL SLOWLY IMPROVE THROUGH THE PERIOD AS H5
TROUGHINESS CONTINUES ALONG THE SRN APPALACHIANS...WITH WEAK UPPER
DIVERGENCE SETTING UP OVER THE MTNS THROUGH TUE. LOW LEVEL SW FLOW
SHOULD PROVIDE SOME UPSLOPE ENHANCEMENT IN THE SW MTNS WHERE CHC
POPS WILL BE KEPT GOING THE LONGEST TONIGHT. SIGNALS ARE MIXED ON
LOW STRATUS DEVELOPMENT TUE MORNING GIVEN A MORE SW TO W DIRECTION
IN THE BL FLOW VERSUS THE SRLY WINDS OBSERVED THIS MORNING. EXPECT
MIN TEMPS TO BE QUITE WARM. THE UPPER FORCING...PWAT IN PROFILES
AROUND 1.75 INCHES...AND A DEVELOPING LEE TROUGH SHOULD GET LIKELY
COVERAGE GOING AGAIN EARLY ON TUESDAY...WITH SIMILAR HAZARDS OF
LOCALLY HEAVY RAINFALL AND AN ISOLD SEVERE THREAT. THICKNESSES
SUPPORT VERY WARM TEMPS NEAR 90 TUE AFTN IN THE PIEDMONT...BUT CLOUD
COVER AND PRECIP SHOULD CURB THAT SOMEWHAT.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 230 PM MONDAY...THE SHORT TERM PERIOD LOOKS RATHER
ACTIVE...HIGHLIGHTED BY A SERIES OF UPPER LEVEL IMPULSES AIDING IN
DIURNAL CONVECTION...AND AN UPPER TROF DIVING THROUGH THE OHIO
VALLEY THROUGH THE END OF THE PERIOD. TUESDAY EVENING A PERSISTENT
BERMUDA HIGH WILL CONTINUE TO PROMOTE SOUTHERLY FLOW. MID TO UPPER
60S DEWPOINTS AND SURFACE TEMPERATURES IN THE 80S WILL CONTINUE TO
ALLOW FOR ENOUGH INSTABILITY FOR CONVECTION INTO THE EVENING HOURS.
THUS...KEPT SOLID CHANCE POPS THROUGH SUNSET. MEANWHILE...UPPER
LEVEL PATTERN BEGINS TO AMPLIFY SOMEWHAT AS TROF DEEPENS ACROSS THE
UPPER MIDWEST. AS THE DISTURBANCE MOVES EASTWARD THROUGH THE
GREAT LAKES REGION ON WEDNESDAY...HEIGHTS ACROSS NORTHEAST GEORGIA
AND THE CAROLINAS WILL BEGIN TO FALL. AS FLOW AT THE SURFACE
REMAINS SOUTHERLY...AND HEIGHTS FALL ALOFT...EXPECTING SOME RATHER
WIDESPREAD CONVECTION TO OCCUR WEDNESDAY AFTERNOON. BOTH GFS AND
NAM FORECAST SOUNDINGS INDICATE SUBSTANTIAL DRYING IN THE MID LEVELS
INTO THE AFTERNOON HOURS THUS STEEPENING LAPSE RATES.
LIKEWISE...SBCAPE VALUES NEARING 1500-2000J/KG CANNOT BE RULED
OUT...ESPECIALLY ACROSS THE HIGHER TERRAIN AND THE UPSTATE OF SC.
KEPT HIGH END CHANCE POPS ACROSS THE ENTIRE REGION WITH SLIGHTLY
HIGHER POPS OVER THE ABOVE MENTIONED AREAS. WITH ALL THAT
SAID...SHEAR PROFILES LOOK RATHER BLEAK AS FLOW THROUGH THE COLUMN
IS WEAK. THUS NOT EXPECTING ANY ROTATING STORMS...LEADING TO A MORE
DAMAGING WIND...LARGE HAIL...AND HEAVY RAINFALL THREAT. MOST IF NOT
ALL CONVECTION SHOULD CEASE BY NEAR OR SLIGHTLY AFTER SUNSET ON
WEDNESDAY EVENING AS DIURNAL HEATING IS LOST. TEMPERATURES WILL BE
SLIGHTLY ABOVE NORMAL FOR MOST AREAS ON WEDNESDAY.
AS THE UPPER TROF DIGS OUT ACROSS THE OHIO AND TENNESSEE RIVER
VALLEYS ON THURSDAY...UPPER LEVEL HEIGHTS WILL FALL FURTHER...AND A
SURFACE COLD FRONT WILL BE MOVING CLOSER TO THE REGION. EXPECTING
MUCH OF THE SAME ON THURSDAY AS SURFACE HEATING AND MODEST DEWPOINTS
WILL ALLOW FOR SUBSTANTIAL CAPE. HOWEVER ALTHOUGH NOT THAT
HIGH...THURSDAY WILL YIELD MORE SHEAR THAN WEDNESDAY AS THE TROF
BASE SWINGS THROUGH...AND THE COLD FRONT APPROACHES. THIS WILL LEAD
TO AT LEAST SOME POTENTIAL FOR BETTER CONVECTIVE ORGANIZATION. LOOK
FOR THE MAIN THREATS ON THURSDAY TO BE DAMAGING WINDS...LARGE
HAIL...AND HEAVY RAINFALL. CONVECTION WILL LIKELY BE MOST INTENSE
ALONG AND AHEAD OF THE FRONT DURING THE AFTERNOON HOURS. WENT WITH
LIKELY POPS EARLY IN THE DAY ACROSS THE HIGHER TERRAIN AND SOLID
CHANCE POPS ELSEWHERE. TEMPERATURES ON THURSDAY WILL BE AT OR
SLIGHTLY BELOW NORMAL AS THUNDERSTORM DEVELOPMENT WILL PLAY A MAJOR
ROLE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 200 PM MONDAY...THE EXTENDED PERIOD BEGINS WITH THE CWA ON THE
FAR WESTERN PERIPHERY OF A BERMUDA HIGH AND AN UPPER LEVEL TROUGH
QUICKLY DEVELOPING OVER THE REGION ON THURSDAY. THE TROUGH DEEPENS
OVER THE WEEKEND AND TAKES OVER THE MAJORITY OF THE EASTERN
CONUS...WHILE A COLD FRONT APPROACHES WITH THE TROUGH AND THEN
STALLS OUT OVER THE AREA FOR THE WEEKEND. THE TROUGH REMAINS THE
DOMINANT FEATURE FOR MOST OF THE EXTENDED PERIOD...WITH HIGH
PRESSURE ONLY BEGINNING TO BUILD BACK IN TO THE WEST OF THE FORECAST
AREA BY EARLY NEXT WEEK. CONVECTION WILL BE MAINLY DIURNAL IN
NATURE...WITH ISOLATED TO SCATTERED COVERAGE OVER THE FOOTHILLS AND
MOUNTAINS EACH AFTERNOON. THE HIGHEST POPS WILL BE FEATURED EARLY IN
THE WEEKEND WITH THE FRONTAL PASSAGE. CLOUD COVER AND THE PERSISTENT
UPPER TROUGH WILL KEEP HIGH TEMPERATURES SLIGHTLY COOLER THAN
AVERAGE OVER THE WEEKEND...BUT NORTHWESTERLY FLOW FOLLOWING THE
FRONT WILL DRY OUT THE AIRMASS AND ALLOW A SLIGHT WARMING TREND BY
LATE WEEKEND/EARLY NEXT WEEK.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
AT KCLT...THE TRAINING CLUSTER OF THUNDERSTORMS HAS SET UP MAINLY S
TO SE OF THE AIRFIELD THIS AFTN...BUT CLOSE ENOUGH TO CARRY WALL TO
WALL THUNDER THROUGH 00Z...WITH TEMPO GUSTS AND MVFR RESTRICTIONS IN
ANY HEAVIER RAINFALL. WE COULD SEE ADDITIONAL DEVELOPMENT FROM THE
FOOTHILLS LATER THIS AFTN/EVENING PER THE LATEST HRRR RUN.
CONFIDENCE IS LOWER ON THAT...SO WILL RAMP DOWN TO A VCSH FOR NOW.
CIGS AND VSBY ARE A REAL QUESTION MARK OVERNIGHT...WITH SOME STRATUS
LIKELY IN THE LOWER PIEDMONT...BUT WITH SW TO W BL FLOW PROVIDING
MUCH LESS OF A PUSH INTO THE TERMINAL AREA. WILL HINT THAT WAY WITH
SCT010 BUT KEEP CIGS AND VSBY VFR FOR NOW. EXPECT AN EARLY START TO
CONVECTION AGAIN ON TUE WITH VERY MOIST PROFILES AND SLIGHTLY
IMPROVING UPPER SUPPORT.
ELSEWHERE...THUNDERSTORMS ARE LIKELY AT TIMES AT ALL THE MTN AND
FOOTHILLS TAF LOCATIONS THIS AFTN AND EVENING. WILL RIDE ON SOME
FAIRLY BROAD VCTS GROUPS FOR NOW...BUT TEMPO WILL LIKELY BE NEEDED
AT TIMES LATER ON. EXPECT MAINLY VFR CIGS EXCEPT BRIEF MVFR IN ANY
TSTMS ALONG WITH BRIEFLY GUSTY WINDS. SCT SHRA OR TSRA COULD
CONTINUE INTO THE OVERNIGHT HOURS...BUT WITH THE BEST FOCUS IN SW
MTN UPSLOPE AREAS...SO WILL ALLOW COVERAGE TO WANE FOR NOW. MTN
VALLEY FOG/CIG PROBLEMS LOOK LIKELY...WITH IFR AT KAVL BY 08Z. EAST
OF THE MTNS...CONFIDENCE IS LOWER GIVEN THE SW TO W BL FLOW. SOME
STRATUS SEEMS LIKELY TOWARD DAYBREAK...AND POSSIBLY VSBY ISSUES IF
THE TERMINALS SEE HEAVY RAINFALL LATE TODAY. EXPECT ANOTHER EARLY
START TO CONVECTION ON TUE WITH THE AIRMASS REMAINING VERY MOIST.
OUTLOOK...EXPECT UNSETTLED WEATHER AT THE TERMINAL LOCATIONS THROUGH
THE WEEK...WITH UPPER TROUGHINESS PERSISTING AND THEN DEEPENING MID
TO LATE WEEK. THIS SHOULD LEAD TO MORNING FOG/STRATUS
RESTRICTIONS...WITH MAINLY AFTN/EVENING TSRA EACH DAY.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 90%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 94% MED 66% MED 71%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 95%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 95% HIGH 95%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...VISIN
NEAR TERM...HG
SHORT TERM...CDG
LONG TERM...VISIN
AVIATION...HG
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
314 PM MDT MON JUN 24 2013
.SHORT TERM...THIS EVENING THROUGH TUESDAY NIGHT
ISSUED AT 313 PM MDT MON JUN 24 2013
CURRENT SURFACE ANALYSIS SHOWS LOW PRESSURE OVER SOUTHEASTERN
MT...WITH WARM FRONT STRETCHING EAST-SOUTHEASTWARD ACROSS NORTHERN
SD. A DRYLINE HAS DEVELOPED SOUTH OF THE LOW ACROSS EASTERN WY.
UPPER LEVEL ANALYSIS SHOWS LOW OVER SOUTHWESTERN ONTARIO...WITH
ANOTHER LOW OFF THE PACIFIC NW COAST. SOUTHWEST FLOW ALOFT IS IN
PLACE ACROSS THE REGION...WITH IMBEDDED SHORTWAVE ENERGY CROSSING
THE REGION. THE NEXT SHORTWAVE UPSTREAM IS MOVING EAST-NORTHEAST
ACROSS CENTRAL AND EASTERN PORTIONS OF WY. REGIONAL RADARS SHOWING
SOME SHOWERS AND STORMS DEVELOPING ACROSS EASTERN WY INTO FAR
WESTERN NEB AND SOUTHWESTERN SD. SKIES ARE PARTLY CLOUDY/MOSTLY
SUNNY ACROSS THE AREA WITH TEMPS GENERALLY IN THE 80S. SOUTH TO
SOUTHEAST WINDS CONTINUE TO BRING LOW LEVEL MOISTURE INTO THE
AREA...WITH DEWPOINTS IN THE UPPER 50S TO MID 60S ACROSS MUCH OF
THE PLAINS RIGHT NOW.
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS CAN BE EXPECTED LATE
TODAY INTO THIS EVENING AS SHORTWAVE ENERGY CROSSES THE AREA. THE
BEST CHANCES FOR PCPN STILL LOOK TO BE ACROSS SOUTHWESTERN INTO
CENTRAL SD. WITH INSTABILITY INCREASING THROUGH LATE TODAY THERE
WILL BE ISOLATED STRONG TO SEVERE STORMS ACROSS THE AREA WITH
LARGE HAIL AND STRONG WIND GUSTS. SHEAR WILL BE ADEQUATE FOR
POSSIBLE SUPERCELLS AS WELL. THE ACTIVITY COULD ORGANIZE INTO AN MCS
THIS EVENING OVER EASTERN PORTIONS OF THE AREA. SHOWERS AND STORMS
WITH THIS WAVE SHOULD GENERALLY END OVER THE CWA BY 06Z.
HOWEVER...ISOLATED SHOWERS/STORMS COULD DEVELOP ACROSS NORTHERN
PORTIONS OF THE CWA LATE TONIGHT AS SOUTHERLY LOW LEVEL JET
INTENSIFIES OVER THE AREA AHEAD OF APPROACHING COLD FRONT.
COLD FRONT WILL MOVE THROUGH THE AREA FROM WEST TO EAST LATE TONIGHT
AND TUESDAY MORNING. THE FRONT COULD STALL OUT OVER SOUTH CENTRAL SD
TUESDAY AFTERNOON. ANY CHANCES FOR SHOWERS AND THUNDERSTORMS SHOULD
BE LIMITED TO NORTHERN AND EASTERN PORTIONS OF THE CWA...MAINLY
DURING THE LATE MORNING AND EARLY AFTERNOON HOURS. DRIER AIR WILL
BUILD IN BEHIND THE FRONT. HOWEVER...NOT MUCH IN THE WAY OF COOLER
AIR IS EXPECTED. HIGHS WILL STILL BE IN THE UPPER 70S AND 80S...WITH
A FEW LOCATIONS AROUND SOUTH CENTRAL SD REACHING 90 DEGREES. BREEZY
TO WINDY NORTHWESTERLY WINDS WILL DEVELOP BEHIND THE FRONT...
ESPECIALLY ACROSS THE NORTHWESTERN AND WEST CENTRAL SD PLAINS. SKIES
WILL BECOME MAINLY CLEAR LATE IN THE DAY WITH DECREASING WIND DURING
THE EVENING.
&&
.LONG TERM...WEDNESDAY THROUGH MONDAY
ISSUED AT 313 PM MDT MON JUN 24 2013
WESTERN ATLANTIC BLOCKING WITH A CONTINUED DEEP NEGATIVE HEIGHT
ANOMALY OVER THE NORTHERN PAC WILL FAVOR A NEAR OMEGA BLOCK OVER
NOAM...WITH A STAUNCH WESTERN NOAM RIDGE EXPECTED. THIS WILL KEEP
THE REGION IN MAINLY DRY NW FLOW. HOWEVER...A RIDGE TOPPING
DISTURBANCE CANNOT BE RULED OUT TOWARD THIS WEEKEND AS INDICATED
IN THE ECMWF. THE QUESTION REMAINS WHETHER THE RIDGE WILL REMAIN
OVER WESTERN NOAM OR BEING TO SHIFT EAST AS SIGNALED IN THE MEAN
GEFS. EITHER WAY...A DRY FORECAST IS FAVORED ATTM. IN
ADDITION...THE REGION WILL REMAIN ON THE EDGE OF THE ASSOCIATED
THERMAL RIDGE...WITH TEMPS IN THE 90S POSSIBLE AT TIMES...EVEN
WARMER BY EARLY NEXT WEEK IF THE RIDGE DOES SHIFT EAST.
OVERALL...VERY LITTLE CHANGE MADE TO THE PREVIOUS FORECAST. WILL SIDE
SLIGHTLY BELOW GUIDANCE MOST OF THE PERIOD GIVEN THE CONTINUED
WARM MODEL BIAS OF LATE...LIKELY FUELED BY ONGOING GREEN AND MOIST
CONDITIONS. RETAINED LOW POPS THIS WEEKEND...WITH DRY CONDITIONS
OTHERWISE
&&
.AVIATION...FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING
ISSUED AT 313 PM MDT MON JUN 24 2013
A STRONG UPPER LEVEL DISTURBANCE AND ASSOCIATED SFC TROUGH WILL
ADVECT THROUGH THE REGION TODAY...SUPPORTING TS DEVELOPMENT THIS
AFTERNOON/EVENING...POSSIBLY SEVERE. STRONG CAPPING MAY LIMIT
STORMS TO DISCRETE SUPERCELLS. HOWEVER...SOME HIRES MODEL
SOLUTIONS FAVOR THE DEVELOPMENT OF A SQUALL LINE ACROSS WESTERN
SD...PROPAGATING EAST THROUGH THE SD PLAINS THIS EVENING. WILL
RETAIN PREVIOUS VCTS MENTION AT GCC AND WILL ADD TEMPO ON A NEED
BE BASIS. DID ADD A TEMPO AT RAP WHERE BETTER CHANCES FOR TS WILL
BE FOUND. MVFR TO IFR CIGS/VIS WOULD BE POSSIBLE WITH ANY
THUNDERSTORM. COLD FRONT WILL PROPAGATE THROUGH THE AREA TUES
MORNING...WITH WINDS SHIFTING NW AND BECOMING BREEZY AT
TIMES...ESP OVER THE SD PLAINS.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...26
LONG TERM...JC
AVIATION...JC
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1132 AM MDT MON JUN 24 2013
.UPDATE...
ISSUED AT 941 AM MDT MON JUN 24 2013
CURRENT SURFACE ANALYSIS SHOWS LOW PRESSURE OVER FAR SOUTHEASTERN
MT...WITH WARM FRONT STRETCHING SOUTHEASTWARD ACROSS WESTERN SD.
UPPER LEVEL ANALYSIS SHOWS LOW OVER SOUTHWESTERN ONTARIO...WITH
ANOTHER LOW OFF THE PACIFIC NW COAST. SOUTHWEST FLOW ALOFT IS IN
PLACE ACROSS THE REGION...WITH IMBEDDED SHORTWAVE ENERGY OVER THE
REGION. ONE SHORTWAVE IS MOVING ACROSS EASTERN PORTIONS OF NEB AND
SD...WITH SHOWERS EXITING SOUTH CENTRAL SD. ANOTHER SHORTWAVE IS
NOTED OVER EASTERN UT AND NORTHWESTERN CO...MOVING NORTHEASTWARD
INTO SOUTHERN WY. SKIES ARE MOSTLY SUNNY ACROSS MUCH OF THE
AREA...WITH TEMPS IN THE UPPER 60S AND 70S. SOUTH TO SOUTHEAST
WINDS CONTINUE TO BRING INCREASING MOISTURE INTO THE AREA...WITH
DEWPOINTS IN THE UPPER 50S AND LOWER 60S ACROSS MUCH OF THE
PLAINS RIGHT NOW.
HAVE MADE MOSTLY MINOR UPDATES TO THE FORECAST FOR THE REST OF
TODAY AND INTO TONIGHT. REMOVED POPS FOR LATE THIS MORNING AND
ADJUSTED AFTERNOON POPS SLIGHTLY TO GIVE BETTER CHANCES FOR LATE
AFTERNOON. SHORTWAVE TO THE SOUTHWEST WILL PUSH INTO SOUTHWESTERN
PORTIONS OF THE CWA DURING THE MID AFTERNOON AND TRACK NORTHEAST
ACROSS THE AREA DURING THE LATE AFTERNOON AND EVENING. LOW
PRESSURE WILL REMAIN OVER NORTHWESTERN PORTIONS OF THE AREA INTO
THE AFTERNOON AND THEN SLOWLY MOVE EAST AS THE SHORTWAVE SLIDES
THROUGH. A DRY LINE WILL ALSO DEVELOP TO THE SOUTH OF THE LOW
ACROSS FAR EASTERN WY DURING THE AFTERNOON...HELPING TO AID IN
THUNDERSTORM DEVELOPMENT AS THE SHORTWAVE ARRIVES. THE BEST
CHANCES FOR PCPN LOOK TO BE ACROSS SOUTHWESTERN INTO CENTRAL SD
LATE THIS AFTERNOON AND EVENING. WITH INSTABILITY PROGGED TO BE
VERY HIGH LATE TODAY AND THIS EVENING...ESPECIALLY SOUTH AND EAST
OF THE BLACK HILLS...THERE WILL LIKELY BE A FEW STRONG TO SEVERE
STORMS ACROSS THE AREA...WITH LARGE HAIL AND STRONG WIND GUSTS.
SHEAR WILL BE ADEQUATE FOR ISOLATED SUPERCELLS AS WELL.
THE OTHER MAIN ADJUSTMENT TO THE FORECAST WAS TO RAISE HIGH TEMPS
A COUPLE OF DEGREES ACROSS AREAS SOUTH AND EAST OF THE BLACK HILLS
AS WARM FRONT LIFTS SLOWLY NORTH AND EAST DURING THE DAY.
&&
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
ISSUED AT 358 AM MDT MON JUN 24 2013
UPPER LEVEL ANALYSIS HAS WEAK RIDGING ACROSS THE NORTHERN AND
CENTRAL PLAINS WITH LARGE TROF OVER THE PACIFIC NORTHWEST. ONGOING
MCS IS PUSHING THROUGH CENTRAL NEBRASKA...AND LOOKS TO CLIP FAR
SOUTH CENTRAL SOUTH DAKOTA EARLY THIS MORNING. AT THE
SURFACE...HIGH PRESSURE IS LOCATED OVER THE CENTRAL CONUS...WITH
LOW PRESSURE DEVELOPING OVER THE NORTHERN ROCKIES. TEMPERATURES
ARE MILD THIS MORNING...MAINLY IN THE 60S. WINDS ARE GENERALLY OUT
OF THE SOUTH TO SOUTHEAST AT 5 TO 15 MPH.
FOR TODAY...OVERNIGHT CONVECTION WILL GRAZE FAR SOUTH CENTRAL
SOUTH DAKOTA DURING THE EARLY MORNING HOURS. BY THE AFTERNOON
INSTABILITY INCREASES GREATLY ACROSS WESTERN SOUTH DAKOTA WITH SOME
MODELS INDICATING CAPE VALUES EASILY OVER 3000 J/KG. SHEAR WILL
BE ADEQUATE TO SUPPORT SUPERCELLS...PARTICULARLY OVER THE ERN CWA.
STRONG STORMS COULD DEVELOP BY EARLY/MID AFTERNOON AS INITIAL WAVE
LIFTS THROUGH SWRLY FLOW. MAIN THREAT WITH THESE STORMS WILL BE
LARGE HAIL AND DAMAGING WINDS. CHANCES WILL CONTINUE INTO THE
EARLY EVENING WITH STORMS PUSHING TO THE EAST OF THE AREA BY LATE
EVENING.
ON TUESDAY...UPPER SHORTWAVE TROF WILL SWING THROUGH WESTERN NORTH
DAKOTA BY EARLY AFTERNOON...AS SURFACE TROF SLIDES THROUGH EASTERN
SOUTH DAKOTA. BEST CHANCE FOR PRECIP WILL BE CONFINED TO NORTH AND
WESTERN PORTIONS OF THE FORECAST AREA. REMAINDER OF THE AREA
SHOULD SEE PARTLY CLOUDY SKIES AND BREEZY WEST TO NORTHWEST WINDS
AS SURFACE TROF MOVES EAST OF THE AREA. HIGH TEMPS WILL BE IN THE
70S AND 80S.
&&
.LONG TERM...WEDNESDAY THROUGH SUNDAY
ISSUED AT 358 AM MDT MON JUN 24 2013
UPPER RIDGE BUILDING OVER THE WESTERN CONUS WILL BRING DRY AND
WARM WEATHER THROUGH THE END OF THE WORK WEEK. MODELS DIVERGE NEXT
WEEKEND AS TO THE STRENGTH OF THE RIDGE. ECMWF KEEPS THE RIDGE
AMPLIFIED OVER THE NRN ROCKIES/NRN PLAINS WHILE THE GFS SHOWS A
SLIGHT BREAKDOWN IN THE RIDGE WITH WESTERLIES DEVELOPING. WILL
FAVOR SLIGHT CHANCES FOR POPS OVER THE WEEKEND...WHILE KEEPING
TEMPS ABOVE AVERAGE.
&&
.AVIATION...FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON
ISSUED AT 1129 AM MDT MON JUN 24 2013
A STRONG UPPER LEVEL DISTURBANCE AND ASSOCIATED SFC
TROUGH WILL ADVECT THROUGH THE REGION TODAY...SUPPORTING TS
DEVELOPMENT THIS AFTERNOON/EVENING...POSSIBLY SEVERE. STRONG CAPPING
MAY LIMIT STORMS TO DISCRETE SUPERCELLS. HOWEVER...SOME HIRES MODEL
SOLUTIONS FAVOR THE DEVELOPMENT OF A SQUALL LINE ACROSS WESTERN
SD...PROPAGATING EAST THROUGH THE SD PLAINS THIS EVENING. WILL
RETAIN PREVIOUS VCTS MENTION AT GCC AND WILL ADD TEMPO ON A NEED
BE BASIS. DID ADD A TEMPO AT RAP WHERE BETTER CHANCES FOR TS WILL
BE FOUND. MVFR TO IFR CIGS/VIS WOULD BE POSSIBLE WITH ANY
THUNDERSTORM. COLD FRONT WILL PROPAGATE THROUGH THE AREA TUES
MORNING...WITH WINDS SHIFTING NW AND BECOMING BREEZY AT
TIMES...ESP OVER THE SD PLAINS.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...26
SHORT TERM...15
LONG TERM...JOHNSON
AVIATION...JC
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1233 AM CDT MON JUN 24 2013
.UPDATE...
ISSUED AT 930 PM CDT SUN JUN 23 2013
LOW LEVEL JET STARTING TO HELP GENERATE SHOWERS AND THUNDERSTORMS
FROM SOUTHEAST NEBRASKA INTO SOUTHERN IOWA. THESE WILL LIKELY
CONTINUE TO DEVELOP NORTHWARD THROUGH THE EVENING. ALTHOUGH THE LOW
LEVEL JET ORIENTATION WOULD SUGGEST THAT THE BEST COVERAGE WILL
REMAIN SOUTHEAST OF OUR CWA. THIS IS SUPPORTED BY THE LATEST HRRR.
HOWEVER DID GO AHEAD AND ADD IN CHANCE POPS ACROSS OUR FAR SOUTH...AS
CANNOT COMPLETELY RULE OUT A STORM MAKING IT UP THERE AFTER ABOUT
08Z. ATTENTION THEN TURNS TO A WAVE COMING OUT OF THE ROCKIES.
CONVECTION ACROSS NORTHEAST COLORADO SHOULD MOVE EAST THROUGH
NEBRASKA OVERNIGHT. LIFT AND MOISTURE TRANSPORT AHEAD OF THIS WAVE
SHOULD ALLOW CONVECTION TO MAINTAIN ITSELF. PREFER THE FASTER TIMING
OF THE HRRR AS COMPARED TO THE NEW SLOWER 4KM NAM. THIS WOULD BRING
THE THREAT INTO OUR SOUTHWEST AROUND 12Z...PUSHING NORTHEAST THROUGH
THE MORNING HOURS. THIS FITS PRETTY WELL WITH THE GOING FORECAST...SO
DID NOT MAKE ANY CHANGES TO POPS TOMORROW. AS MENTIONED
BELOW...SEVERE THREAT SHOULD BE LOW WITH THIS MORNING
CONVECTION...ALTHOUGH MUCAPE APPROACHING 2000 J/KG MAY BE ENOUGH FOR
A FEW MARGINAL HAIL PRODUCING STORMS. TIMING OF THIS WAVE IS STILL
UNCERTAIN. IF IT ENDS UP SLOWER AND WE ARE ABLE TO GET MORE DAYTIME
HEATING AHEAD OF IT...THE SEVERE POTENTIAL WOULD PROBABLY INCREASE.
STILL TOUGH TO SAY WHAT HAPPENS TOMORROW NIGHT UNTIL WE SEE WHAT THE
FIRST WAVE DOES. SEEMS LIKELY STORMS FIRE IN THE WESTERN PLAINS
DURING THE AFTERNOON WITH A SECOND WAVE. WHETHER THESE SURVIVE INTO
OUR CWA IS STILL UP IN THE AIR...WITH MOST CONVECTION ALLOWING MODELS
SAYING NO...AND THE LOWER RESOLUTION NAM...GFS AND EC SUGGESTING YES.
PROBABLY DEPENDENT ON EXTENT OF DRYING...SUBSIDENCE AND CAPPING BEHIND
THE FIRST WAVE. WILL JUST HAVE TO CONTINUE TO MONITOR TRENDS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 341 PM CDT SUN JUN 23 2013
A FRONTAL BOUNDARY CONTINUES TO PUSH THROUGH THE EASTERN PORTION OF
THE CWA THIS AFTERNOON AND IS EXPECTED TO EXIT THE AREA LATE THIS
AFTERNOON. CONVECTION WHICH WE EARLIER THOUGHT MIGHT DEVELOP IN OUR
SOUTHEAST LATE THIS AFTERNOON NOW LOOKS TO HOLD OFF UNTIL LATER IN
THE EVENING...WHEN THE BOUNDARY IS OUT OF OUR AREA...SO DO NOT
ANTICIPATE ANY DEVELOPMENT OVER OUR AREA. OTHERWISE...THE REMAINDER
OF THE NIGHT SHOULD BE QUIET AS WEAK HIGH PRESSURE BUILDS INTO THE
REGION. THIS WILL ALLOW FOR WINDS TO DIE OFF...AND CANNOT RULE OUT
SOME PATCHY FOG DEVELOPMENT WITH RECENT RAINS...THOUGH DID NOT
INCLUDE IN FORECAST AT THIS POINT WITH LOW CONFIDENCE. THE FORECAST
BECOMES MORE CHALLENGING LATER TONIGHT INTO MONDAY...WITH MODELS
DIFFERING ON THE TIMING AND STRENGTH OF ANOTHER SHORT WAVE LIFTING
UP OVER THE AREA DURING THE DAY ON MONDAY. MONDAYS SHORT WAVE IS
CURRENTLY VISIBLE ON THE WATER VAPOR IMAGERY NEAR LAS VEGAS NV. THE
GFS/GEM/4KM NAM AND SREF OFFER THE WETTER SOLUTIONS AS THEY ARE
STRONGER IN THE MID LEVELS...WHILE THE ECMWF AND NAM KEEP IT DRY
DURING THE DAYTIME HOURS...ALTHOUGH THE NAM DOES SHOW SOME WEAK PV
ON THE 1.5 SURFACE. ELECTED TO GO WITH THE WETTER SOLUTIONS WITH
850 MB THETA E ADVECTION INCREASING OVER THE AREA AS THE LOW
LEVEL JET CRANKS UP OUT OF EASTERN NEBRASKA. IN ADDITION THERE
WILL BE INSTABILITY AND SOME SHEAR...THOUGH IN THE ABSENCE OF
CAPPING WOULD EXPECT NO REAL UPDRAFT ENERGY TO BE STORED UP. SO
OTHER THAN SOME POSSIBLE SMALL HAIL WOULD NOT EXPECT SEVERE STORMS
DURING THE DAY. THIS OF COURSE WILL IMPACT HIGH TEMPERATURES...SO
WENT WITH COOLER GUIDANCES WITH HIGHS INTO THE LOWER 80S NORTHEAST
TO THE UPPER 80S ALONG THE MISSOURI RIVER CORRIDOR.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 341 PM CDT SUN JUN 23 2013
MONDAY NIGHT IS THE MOST ACTIVE PERIOD IN THE LONGER TERM. ANOTHER
STRONGER SHORT WAVE FOLLOWS MONDAY WAVE...WHICH WATER VAPOR SHOWS
CURRENTLY OFF OF THE CA COAST. INTERESTINGLY...THE HI RES MODELS
WHICH ARE SO ACTIVE ON MONDAY LEAVE MONDAY NIGHT DRY. HOWEVER THE
NAM AND ECMWF ARE WET...ESPECIALLY ALONG AND NORTH OF I 90. THE
ECMWF HAS BEEN VERY CONSISTENT WITH THIS FEATURE FOR 4 OR 5 DAYS
NOW. SO IT IS VERY HARD TO IGNORE. THE NAM IS STRONG WITH THE
PV 1.5...AND ABUNDANT INSTABILITY AND WIND SHEAR CONTINUES. MOST
OF THE RAINFALL WILL OCCUR IN THE EVENING HOURS...AGAIN WITH THE
HIGHEST CHANCES FOR HEAVIER RAINFALL ALONG AND NORTH OF I 90. NAM
PWATS IN THOSE AREAS AVERAGE 1.5 TO 2.0 INCHES AND SOME SEVERE
WEATHER IS POSSIBLE GIVEN THE INSTABILITY PARAMETERS. THE WAVE
QUICKLY EXITS AFTER MIDNIGHT...WHICH WILL LEAVE TUESDAY DRY AND
VERY WARM AND HUMID.
UPPER RIDGING THEN BUILDS AS ADVERTISED AND RETROGRADES WESTWARD
BY LATE WEEK AND NEXT WEEKEND. A SURFACE BOUNDARY MOVES THROUGH
OUR AREA LATE TUESDAY NIGHT SHIFTING OUR WINDS TO THE NORTHWEST
FOR WEDNESDAY. WITH BETTER MIXING...TEMPERATURES WILL STILL BE
QUITE WARM...WITH LESS HUMID CONDITIONS WEST OF I 29. AS THE UPPER
RIDGE RETROGRADES TO THE WEST CREATING A HIGHLY AMPLIFIED PATTERN...
IT STILL LOOKS AS THOUGH TEMPERATURES WILL START A COOLING TREND
ON THURSDAY...LASTING THROUGH THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1231 AM CDT MON JUN 24 2013
ONE WAVE WHICH RECENTLY PUSHED PAST THE FOUR CORNERS WILL MOVE
INTO THE AREA EARLY THIS MORNING. GIVEN THE LOW LEVEL JET...AND
APPARENT BOUNDARY ACROSS SOUTHEAST/CENTRAL NEBRASKA...EXPECT A
FEW STORMS TO DEVELOP ALONG WARM ADVECTIVE WING AND IMPACT KSUX
AREA AFTER 09Z...AND THEN A BETTER COVERAGE OF SHOWERS/STORMS BY
MORNING HOURS FOR KFSD AND KSUX...BUT EXITING NORTHEAST FAIRLY
QUICKLY. UPSTREAM AND STRONGER WAVE UPSTREAM AROUND RENO NV WILL
FOLLOW...AND WILL LIKELY RESULT IN ADDITIONAL CONVECTION ACROSS
THE AREA...BUT FOR NOW HELD OFF MENTION UNTIL AFTER 00Z.
PROBABILITY OF MVFR FOG IS FAIRLY LOW...LIKELY HIGHEST AROUND
KSUX...BUT WILL ALSO HAVE INITIAL INCREASE IN CLOUDS FROM
CONVECTION TO SOUTH...AND WILL NOT MENTION ON THIS FORECAST SET.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...CHENARD
SHORT TERM...JM
LONG TERM...MJ
AVIATION...08
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1223 AM CDT MON JUN 24 2013
.UPDATE...
SEE UPDATED AVIATION DISCUSSION BELOW.
WINDS HAVE GONE LIGHT LATE THIS EVENING UNDER CLEAR SKIES AND
SURFACE HIGH PRESSURE RIDGING. THE WINDS WILL TURN SOUTH BEHIND
THIS RETREATING HIGH PRESSURE AREA TONIGHT. ALREADY HAVE MID LEVEL
WAA CLOUDS/ACCAS AND COOLING TOPS IN WY/SE MT LATE THIS EVENING
MOVING QUICKLY EAST. THESE WILL CONTINUE TO MOVE EAST AND MAY
BECOME HIGH BASED SHOWERS/THUNDER AS THEY MOVE INTO WESTERN SD AND
INTO OUR WESTERN CWA LATER TONIGHT. THE LATEST HRRR MODEL SHOWS
SOME SPOTTY QPF LATER TONIGHT. ALREADY HAVE IN SLIGHT CHANCES WEST
IN THE CWA AFTER MIDNIGHT.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT
THE ACTIVE SUMMER PATTERN CONTINUES EARLY THIS WEEK AS RETURN
FLOW MOISTURE AND INSTABILITY MAKE A QUICK RETURN TO THE WESTERN
ZONES OVERNIGHT AND SPREADS EAST MONDAY AND MONDAY EVENING.
MODELS ARE AGAIN OFFERING A CHALLENGING FORECAST WITH TIMING AND
STRENGTH OF SHORTWAVES AND CONVECTION...BUT THUNDERSTORMS LOOK
LIKE A GOOD BET MONDAY NIGHT MOST LOCATIONS AND AGAIN TUESDAY
NIGHT IN THE EAST. SPC HAS AREA IN SLIGHT RISK FOR MONDAY NIGHT
AND THE EASTERN PORTION FOR TUESDAY.
DESPITE RISING HEIGHTS...DEEP SOUTHWEST FLOW ALOFT WILL CONTINUE
TO EJECT SHORTWAVES INTO THE UPPER PLAINS. WITH INSTABILITY
RETURN IN THE WEST LATE TONIGHT HAVE ADDED SMALL POPS TO THE
FORECAST FOR AREAS ALONG AND WEST OF THE MISSOURI RIVER.
HEAT...MOISTURE AND INSTABILITY WILL INCREASE THE NEXT FEW DAYS
WITH TEMPS CLIMBING INTO THE UPPER 80S AND MID 90S BY TUESDAY.
THE HEAT INDEX WILL CLIMB INTO THE MID TO UPPER 90S ON TUESDAY.
AS MENTIONED ABOVE...MODELS IN ARE NOT IN VERY GOOD AGREEMENT
WITH TIMING OF CONVECTION...BUT OVERALL FEEL CONFIDENT FOR
THUNDERSTORMS FOR BOTH MONDAY AND TUESDAY EVENINGS...POSSIBLY
SEVERE AS INSTABILITY INCREASES.
.LONG TERM...WEDNESDAY THROUGH SUNDAY
IT APPEARS THE THEMES RUNNING THROUGHOUT THE EXTENDED ARE WARM AND
MOSTLY DRY. AT THIS POINT...POPS/WX MENTION DO NOT SHOW UP IN THE
OUT PERIODS BASICALLY UNTIL SATURDAY LATE AFTERNOON/EARLY EVENING.
UNTIL THEN...REBOUNDING MID/UPPER LEVEL HEIGHTS ARE FORECAST TO
DEVELOP ACROSS THE WESTERN TWO-THIRDS OF THE CONUS STARTING
WEDNESDAY AND PERSIST THROUGH THE END OF THE PERIOD. A LOW
PRESSURE SYSTEM IS PROGGED TO TRY WORKING THROUGH THE TOP OF THE
RIDGE...IN EFFECT...FLATTENING IT SOMEWHAT OVER THE WEEKEND AND
BRINGING A SMALL CHANCE AT CONVECTION ACROSS THE CWA BY SATURDAY
EVENING. AT THIS TIME...700HPA THERMAL PROGS ARE AT OR ABOVE +14C
ON SATURDAY...SO IT WILL TAKE QUITE A BIT OF MOISTURE/INSTABILITY
AND STRONG FORCING AROUND TO GET STORMS TO DEVELOP IN THAT WARM OF
A MID-LEVEL ENVIRONMENT. SPEAKING OF WARM...WITH HEIGHTS RISING IN
THE ATMOSPHERE...A GOOD CHUNK OF THE EXTENDED SHOULD BE LOOKING AT
NEAR TO ABOVE NORMAL HIGH TEMPERATURES IN THE 80S AND 90S DURING
THE MID TO LATE PORTIONS OF THE WEEK.
&&
.AVIATION...
06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS ARE EXPECTED AT ALL TERMINALS THROUGH TONIGHT AND
MONDAY. AN UPPER LEVEL LOW PRESSURE TROUGH ALONG WITH RETURNING
WAA WILL SPREAD MID LEVEL CLOUDS ACROSS THE REGION THROUGH MONDAY.
WITH INSTABILITY ALSO RETURNING/INCREASING...SOME
SHOWERS/THUNDERSTORMS SHOULD ALSO DEVELOP MAINLY LATE TONIGHT AND
MONDAY. LEFT ANY MENTION OUT OF THE TERMINALS AT THIS TIME WITH
THE UNCERTAINTY OF LOCATION AND TIMING INVOLVED. SOUTHEAST WINDS
WILL ALSO BECOME BREEZY ON MONDAY AT 15 TO 20 KNOTS WITH HIGHER
GUSTS AT MBG AND PIR.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...WISE
SHORT TERM...DORN
LONG TERM...SCARLETT
AVIATION...WISE
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
1006 AM EDT MON JUN 24 2013
.DISCUSSION...
VORT MAX ASSOCIATED WITH CONVECTION OVER W KY STILL LOOKS TO BE
SLOWLY DRIFTING TOWARD OUR AREA. THE APPROACH OF THIS FEATURE WILL
BRING AN INCREASE IN MOISTURE AND HELP TO TRIGGER CONVECTION THIS
AFTERNOON. LATEST RUC SOUNDINGS SHOW CAPES GENERALLY RANGING FROM
2000 TO 2500 J/KG BY 18Z. SOME AREAS MAY BECOME SLIGHTLY MORE OR
LESS UNSTABLE DEPENDING ON CLOUD COVER. IT STILL LOOKS LIKE AREAS TO
THE WEST HAVE GREATER CHANCES OF SEEING CONVECTION...AS LATEST NAM
AND RUC MODELS DEVELOP CONVECTION OVER MIDDLE TN AND ADVANCE IT
TOWARDS THE PLATEAU. CONVECTIVE COVERAGE SHOULD BE A LITTLE MORE
WIDESPREAD THAN THE PAST FEW DAYS AND NOT LIMITED TO ONLY THE HIGHER
ELEVATIONS. ALSO...CAN`T RULE OUT AN ISOLATED SEVERE STORM TODAY DUE
TO INCREASED INSTABILITY AND MOISTURE...WITH THE MAIN THREAT BEING
DAMAGING WINDS. LOCALLY HEAVY RAINFALL IS ALSO POSSIBLE DUE TO SLOW
STORM MOTIONS OF AROUND 9 KTS.
OVERALL...CURRENT FORECAST APPEARS TO BE ON TRACK. NO UPDATES
PLANNED AT THIS TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 88 68 90 70 90 / 40 30 30 10 30
KNOXVILLE MCGHEE TYSON AIRPORT, TN 87 67 89 69 90 / 40 30 20 10 30
OAK RIDGE, TN 86 67 89 69 90 / 40 20 20 10 30
TRI CITIES AIRPORT, TN 87 64 88 63 89 / 30 20 30 10 30
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
SR
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
310 AM EDT MON JUN 24 2013
.SHORT TERM (TODAY AND TONIGHT)...
SOME SHOWERS ARE PERSISTING IN THE SOUTHERN HALF OF THE AREA THIS
MORNING...AND THE RUC SHOWS AN AREA OF LOW LEVEL MOISTURE
CONVERGENCE IN THIS AREA. THE RUC SHOWS THIS WEAKENING BY 12Z...BUT
WILL INCLUDE A SLIGHT CHANCE POP IN ALL AREAS THROUGH THE MORNING.
IN THE AFTERNOON...WE WILL SEE A REMNANT VORT MAX FROM CONVECTION
OVER W KY ENTER THE AREA...AND THE NAM DEVELOPS CONVECTION IN MIDDLE
TN AND THE PLATEAU ALONG AN OUTFLOW BOUNDARY. INSTABILITY APPEARS
GREATEST IN THAT AREA...SO WILL HAVE HIGHEST POPS WEST TODAY...BUT
STILL IN THE CHANCE RANGE EVERYWHERE. WILL CONTINUE WITH PERSISTENCE
FOR TEMPERATURES TODAY AND TONIGHT.
.LONG TERM (TUESDAY THROUGH SUNDAY)...
BERMUDA RIDGE WILL REMAIN OVER THE SOUTHEAST UNITED STATES THROUGH
MID-WEEK. GFS AND NAM SHOW PWS AND INSTABILITY INCREASING TO 1.4 TO
1.6 INCHES FOR TUESDAY AND WEDNESDAY..SO COVERAGE AND INTENSITY OF
STORMS WILL LIKELY INCREASE TO SCATTERED. FOR THURSDAY INTO NEXT
WEEKEND...RIDGING OVER THE SOUTHERN APPALACHIANS WILL WEAKEN
ALLOWING A SERIES OF UPPER SHORT- WAVES OVER THE GREAT LAKES INTO
THE NORTHEAST TO CARVE OUT A LONG- WAVE TROUGH OVER THE EASTERN
UNITED STATES.
LOOKING AT INSTABILITY AND UPPER DYNAMICS...BEST CHANCE OF MORE
WIDESPREAD STRONG TO SEVERE STORMS STILL POINT TO THURSDAY AND WILL
MENTION IN THE HWO. A COLD FRONT MOVING THROUGH SATURDAY WILL BRING
IN DRIER DEWPOINTS FOR SUNDAY.
AS FOR TEMPERATURES...GENERALLY FOLLOWED GFS NUMBERS CLOSELY..EXCEPT
FOR THE LATTER HALF OF THE WEEK. LOWER THICKNESS AND GREATER
COVERAGE OF CLOUDS AND CONVECTION DOES NOT WARRANT THE GFS HIGHS..SO
UNDER-CUT A DEGREE OR TWO.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 88 68 90 70 90 / 40 30 30 10 30
KNOXVILLE MCGHEE TYSON AIRPORT, TN 87 67 89 69 90 / 40 30 20 10 30
OAK RIDGE, TN 86 67 89 69 90 / 40 20 20 10 30
TRI CITIES AIRPORT, TN 87 64 88 63 89 / 30 20 30 10 30
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS/DH
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1128 PM CDT SUN JUN 23 2013
.AVIATION...
VFR EXPECTED TO DOMINATE...THOUGH WRF/NAM AND RAP SOLUTIONS
CONTINUE TO INDICATE NEAR-SATURATION OCCURRING BETWEEN 11Z-15Z AT
KLBB MONDAY MORNING NEAR H850 MB OR CLOSE TO 2000 FEET ABOVE THE
GROUND. SLIGHT UPGRADE IN WORDING TO A TEMPO SCATTERED LOW CLOUD
GROUP FOR KLBB DURING THIS PERIOD. FOR MONDAY AFTERNOON...LATEST
SOLUTIONS IN-LINE WITH OUR THINKING THAT THE SURFACE DRY-LINE SHOULD
NOT MAKE AS MUCH HEADWAY TO THE EAST...REMAINING WEST-NORTHWEST
OF KLBB. THUNDER CHANCES TOO LIMITED TO INCLUDE IN THIS TAF EDITION.
RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 924 PM CDT SUN JUN 23 2013/
UPDATE...
SHOWER CHANCES HAVE DWINDLED MOST OF THE AREA AS THE DRY-LINE
RETREATED RAPIDLY TO THE WEST THIS EVENING. RETAINED ISOLATED
MENTION ACROSS THE NORTHWEST...AND REMOVED THUNDER MENTION
ELSEWHERE. RMCQUEEN
PREV DISCUSSION... /ISSUED 717 PM CDT SUN JUN 23 2013/
UPDATE...
HIGH-BASED SHOWERS HAVE BEEN LATE TO DEVELOP...POSSIBLY DEVELOPED AS
DRY-LINE RETREATED INTO THE WESTERN SOUTH PLAINS. AS SUCH... SOME
DOUBT WHETHER THESE WEAK CELLS WILL BE ABLE TO SURVIVE AS THEY
TREK TO THE EAST-NORTHEAST. AND ALREADY WE ARE SEEING WEAKENING
TREND. RMCQUEEN
AVIATION...
ISOLATED HIGH-BASED SHOWERS HAVE DEVELOPED LATE ABOUT 20 MILES
WEST OF KLBB...AFTER WE ALREADY ISSUED THE 00Z TAF. WILL STUDY
CLOSE THE NEED FOR ADDING SHOWER OR THUNDER MENTION FOR KLBB. VFR
CONDITIONS OTHERWISE EXPECTED TO DOMINATE WITH SOUTHWEST FLOW
ALOFT AND A SURFACE TROUGH. STILL OUTSIDE RISK OF MVFR CEILINGS AT
KLBB EARLY MONDAY MORNING. RMCQUEEN
PREV DISCUSSION... /ISSUED 314 PM CDT SUN JUN 23 2013/
SHORT TERM...
LITTLE CHANGE IN THE LARGE SCALE PATTERN OR OVERALL THINKING WITH
REGARDS TO THE FORECAST TONIGHT INTO MONDAY...WITH BIGGEST CONCERN
REVOLVING AROUND STORM CHANCES THIS EVENING AND AGAIN LATE IN THE
DAY MONDAY. THE REGION CONTINUES TO RESIDE ON THE THE SOUTHERN
FRINGE OF SOUTHWESTERLY FLOW ALOFT WITH SEVERAL SUBTLE WEAKNESSES
MOVING THROUGH THE FLOW AND SKIRTING THE AREA PERHAPS PROVIDING WEAK
SUPPORT...THOUGH NWP IS MIXED WITH THIS SIGNAL. REGARDLESS..STRONG
HEATING IS TAKING PLACE WITH A SFC TROUGH STRETCHING FROM THE
CENTRAL TEXAS PANHANDLE INTO SOUTHEAST NEW MEXICO. AS OF 19Z...LIGHT
SOUTHWESTERLY WINDS AND DEWPOINTS FALLING INTO THE 40S AND 30S HAVE
INVADED THE WESTERN ZONES...SETTING UP A DIFFUSE DRYLINE...WITH
DEWPOINTS IN THE 50S ACROSS THE CENTRAL ZONES AND SOME LOWER 60S
HOLDING OFF THE CAPROCK. DEEP MIXING AND CONVERGENCE ALONG THE
DRYLINE MAY BE ENOUGH TO TRIGGER ISOLATED TO WIDELY SCATTERED
CONVECTION THROUGH EARLY THIS EVENING. IN ADDITION...THE TTU-WRF AND
HRRR SUGGEST OROGRAPHIC FORCING NEAR CAPROCK CANYONS MAY BE ENOUGH
TO INITIATE A STORM THERE. LATEST OBJECTIVE ANALYSIS SHOWS MLCAPES
AOA 2000 J/KG EAST OF THE DRYLINE...THOUGH WITH SOME INHIBITION YET
TO BE OVERCOME. DEEP LAYER SHEAR IS NOT OVERLY IMPRESSIVE...AROUND
25 KNOTS...PERHAPS PUSHING TOWARD 30 KNOTS BY THIS EVENING. THAT
SAID...IF STORMS DO DEVELOP...STRONG INSTABILITY COUPLED WITH THE
MODEST SHEAR WOULD SUPPORT A SEVERE THREAT. IN ADDITION...SLOW STORM
MOTIONS AND PWATS HOLDING IN EXCESS OF 1 INCH WILL SUPPORT A LOCALLY
HEAVY RAIN THREAT. ANY CONVECTION SHOULD FADE BY LATE THIS EVENING
AS THE LOWER ATMOSPHERE COOLS. HOWEVER...A SIMILAR SETUP WILL
PRESENT ITSELF AGAIN ON MONDAY THOUGH THE MOST RECENT SOLUTIONS DO
SUGGEST THE SFC TROUGH/DRYLINE WILL HALT FURTHER TO THE WEST NEAR
THE TX/NM LINE DURING THE AFTERNOON...KEEPING THE BEST STORM CHANCES
A LITTLE FURTHER WEST AS WELL.
BREEZY SOUTHERLY SFC WINDS OVERNIGHT /BENEATH A MODEST LLJ/ WILL
YIELD ANOTHER MILD NIGHT WITH LOWS BY MORNING RANGING FROM THE
MID-60S NORTHWEST TO MID-70S SOUTHEAST. THESE SOUTHERLY WINDS MAY
TRANSPORT SLIGHTLY IMPROVED LOW-LEVEL MOISTURE FROM WHAT WE SAW THIS
MORNING AND COULD EVEN RESULT IN A FEW LOW CLOUDS TOWARD MORNING.
ANOTHER HOT DAY WILL FOLLOW WITH HIGHS WELL INTO THE 90S.
TEMPERATURES MAY ACTUALLY STAY A FEW DEGREES COOLER ACROSS THE
WESTERN ZONES WHERE MOISTURE LEVELS SHOULD STAY HIGHER THAN TODAY.
ONGOING FORECAST HAD ALL OF THIS WELL IN HAND AND ONLY MINOR
ADJUSTMENTS WERE MADE TO THE FORECAST GRIDS.
LONG TERM...
UPPER RIDGE TO BEGIN BUILDING OVER THE ROCKIES TUESDAY WITH
INCREASING HEIGHTS AND MID LEVEL TEMPS LIKELY SHUTTING DOWN
DIURNAL PRECIP CHANCES...ALTHOUGH MODELS GIVING SOME INDICATION OF
ISOLATED HIGH-BASED STORMS DURING THE LATE AFTERNOON...A
POSSIBILITY TOO REMOTE ATTM TO INCREASE POPS TO SLIGHT CHANCE
CATEGORY. OTHER ISSUE IS PRECIP CHANCES FRIDAY THROUGH SUNDAY.
PREVIOUS MODEL RUNS INDICATED POTENTIAL FOR A COLD FRONT AND/OR
UPPER LEVEL DISTURBANCES TO MOVE SWD DOWN THE PLAINS ON THE EAST
SIDE OF THE UPPER RIDGE. THIS MORNING RUNS NOW PUSHING A PORTION
OF THE RIDGE EWD ALL THE WAY TOWARD THE LOWER MISSISSIPPI VALLEY
WHICH WOULD KEEP PRECIP MECHANISMS SHUT DOWN. WITH POPS ALREADY
BELOW MENTION DURING THAT PERIOD...WILL KEEP THEM THERE WITH JUST
SOME SLIGHT MASSAGING OF THOSE SUB-15 PCT POPS. THE POTENTIAL FOR
THE RIDGE TO BUILD EWD ALSO MEANS TEMPS WARMER THAN INDICATED IN
LAST SEVERAL FCST CYCLES AND WILL NUDGE UPWARDS BASICALLY KEEPING
HIGHS IN THE UPPER 90S ON THE CAPROCK AND NEAR 100 OFF THE CAP
THROUGH THE PERIOD WHILE OVERNIGHT LOWS GENERALLY MID 60S TO NEAR
70 ON THE CAP TO LOWER 70S OFF.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 66 95 65 99 66 / 20 20 20 10 10
TULIA 68 94 68 99 67 / 20 20 20 10 10
PLAINVIEW 70 95 69 99 69 / 20 20 20 10 10
LEVELLAND 67 95 68 99 69 / 20 20 20 10 10
LUBBOCK 70 95 71 99 72 / 20 20 20 10 10
DENVER CITY 68 95 69 99 69 / 20 20 20 10 10
BROWNFIELD 66 96 68 99 69 / 20 20 20 10 10
CHILDRESS 73 97 72 100 73 / 20 10 10 10 10
SPUR 71 96 71 99 72 / 10 10 10 10 10
ASPERMONT 75 98 73 99 74 / 10 10 10 10 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
05/99/05
AREA FORECAST DISCUSSION
NWS AMARILLO TX
1117 PM CDT SUN JUN 23 2013
.AVIATION...
06Z TAFS...BREEZY SOUTHERLY WINDS WILL BE THE RULE THROUGH THE NEXT
24 HOURS...WITH GUSTS AROUND 30 KTS EXPECTED LATE MONDAY MORNING INTO
MONDAY EVENING. A FEW SHOWERS ARE CURRENTLY SLOWLY MOVING TOWARD KAMA.
STILL PRETTY LOW CONFIDENCE THAT THEY/LL REACH THE TERMINAL BEFORE
DISSIPATING...AND EVEN IF THEY DO...IMPACTS WILL BE MINIMAL.
THUNDERSTORMS WILL ONCE AGAIN BE POSSIBLE LATE MONDAY AFTERNOON AND
EVENING...BUT CONFIDENCE IN THESE DIRECTLY IMPACTING A TERMINAL IS
TOO LOW TO MENTION ATTM. VFR CONDITIONS ANTICIPATED OUTSIDE OF ANY
THUNDERSTORMS.
NOTE TO USERS OF SURFACE OBSERVATION FROM RICK HUSBAND INTERNATIONAL
AIRPORT KAMA...COMMUNICATIONS PROBLEM WITH DATA LINE HAS PREVENTED
LONG-LINE DISSEMINATION OF SURFACE OBS. DATA COLLECTION PLATFORM AT
KAMA ASOS IS FUNCTIONING PROPERLY WITH CONTINUOUS MONITORING OF ALL
ELEMENTS BY AMARILLO NATIONAL WEATHER SERVICE FORECAST STAFF.
KB
&&
.PREV DISCUSSION... /ISSUED 952 PM CDT SUN JUN 23 2013/
UPDATE...
SHORTWAVE OVER SOUTHEASTERN AND EASTERN NEW MEXICO IN THE
SOUTHWESTERLY UPPER FLOW ACROSS THE PANHANDLES ALLOWING FOR
ADDITIONAL CONVECTION TO DEVELOP IN THE FAR EASTERN PLAINS OF NEW
MEXICO MOVING NORTHEAST INTO THE SOUTHWESTERN TEXAS PANHANDLE.
EXPANDED THE POPS THROUGH 06Z MONDAY A LITTLE FURTHER WESTWARD TO
ACCOUNT FOR THIS ROUND OF CONVECTION. SHORT RANGE MODELS IN GOOD
AGREEMENT SHOWING CONVECTION DEVELOPING ACROSS THE NORTHEAST TEXAS
AND EASTERN OKLAHOMA PANHANDLES TOWARD 09Z MONDAY. INTRODUCED THE 10
POP RULE OVER THE EASTERN SECTIONS OF THE PANHANDLES TO ACCOUNT FOR
THIS POSSIBILITY. DID NOTICE A LONE THUNDERSTORM ACROSS THE
SOUTHEASTERN TEXAS PANHANDLE LAST NIGHT AROUND 09Z SUNDAY OR SO...AND
CANNOT RULE OUT A SIMILAR SCENARIO ACROSS THE NORTHEASTERN OR EASTERN
SECTIONS OF THE FORECAST AREA LATER TONIGHT. LOW LEVEL JET ACROSS THE
EASTERN PANHANDLES LATE TONIGHT MAY ALSO HELP ADDITIONAL CONVECTION
TO DEVELOP LATE TONIGHT. ADJUSTED WIND AND SKY GRIDS TONIGHT...AND
ALSO POPULATED THE SMOKE MANAGEMENT GRIDS WITH THE LATEST NAM DATA
AND UPDATED THE LAL AND 20 FOOT WIND GRIDS. OTHERWISE...NO OTHER
CHANGES MADE TO PREVIOUS FORECAST AND GRIDS.
ALL PUBLIC AND FIRE WEATHER PRODUCTS HAVE BEEN UPDATED AND SENT.
SCHNEIDER
PREV DISCUSSION... /ISSUED 319 PM CDT SUN JUN 23 2013/
DISCUSSION...
JUST ONE MORE DAY OF THIS ACTIVE WEATHER PATTERN THAT THE REGION HAS
BEEN UNDER FOR OVER A WEEK NOW.
TONIGHT INTO TOMORROW...PRECIP CHANCES...THOUGH
MENTIONABLE...CONTINUE TO DECLINE AS DRY AIR ADVECTION CONTINUES.
PRECIPITABLE WATER VALUES ON THIS MORNINGS SOUNDING SHOW 0.79
INCHES...WHICH IS 92 PERCENT OF NORMAL...BUT A FAR CRY FROM THE 1
PLUS INCH VALUES WE/VE SEEN LATELY. IN ADDITION...IN THE WAKE OF THE
UPPER LEVEL TROUGH THAT MOVE THROUGH EARLY THIS MORNING...THERE IS
SOME UPPER LEVEL SHORT WAVE RIDGING OVER THE REGION. THIS SHOULD KEEP
COVERAGE OF STORMS VERY LIMITED. HOWEVER...IT IS INTERESTING TO NOTE
THAT THE RAP HIGH RESOLUTION MODEL SHOWS MORE COVERAGE THAN
YESTERDAY. IF ANY STORMS DEVELOP EITHER THIS AFTERNOON OR
TOMORROW...THE POTENTIAL REMAINS FOR MARGINALLY SEVERE HAIL AND DRY
AND HYBRID DOWNBURSTS LEADING TO STRONG WINDS.
TUESDAY THROUGH THURSDAY...INCREASING CONFIDENCE WITH VERY GOOD MODEL
AGREEMENT AND CONSISTENCY THAT THE RIDGE WILL BUILD OVER THE
SOUTHWEST THROUGH THIS PERIOD BRINGING A DRY AND HOT WEATHER PATTERN
THROUGH THE WEEK. STAYED CLOSE TO THE PREVIOUS FORECAST STILL
FAVORING HIGHER MAX TEMPS IN THE NORTHWESTERN PANHANDLES...WHICH
HAVE SEEN VERY LITTLE RAIN...WHILE KEEPING THE SOUTHEASTERN TX
PANHANDLE A FEW DEGREES LOWER DUE TO THE WET SOIL CONDITIONS.
HOWEVER...BY THE END OF THE WEEK...THESE DIFFERENCES MAY BE
NEGLIGIBLE AS THE SOILS DRY.
FRIDAY THROUGH SUNDAY...MODELS CONTINUED THE TREND OF SHOWING A
PERSISTENT RIDGE CONTINUING THROUGH THIS PERIOD. THE COLD FRONT WHICH
WAS SHOWN IN THE GFS TO ARRIVE ON FRIDAY...HAS ALL BUT DISAPPEARED IN
THE 12Z RUN. THUS...STAYED CLOSE TO THE PREVIOUS FORECAST WITH HOT
AND DRY WEATHER CONTINUING THROUGH THE WEEK.
JOHNSON
FIRE WEATHER...
ELEVATED TO NEAR CRITICAL FIRE WEATHER CONDITIONS MAY OCCUR TOMORROW
IN THE WESTERN OKLAHOMA AND FAR NORTHWESTERN TEXAS
PANHANDLES...THOUGH UNCERTAINTY REMAINS. MINIMUM RELATIVE HUMIDITY
VALUES SHOULD BE BELOW 15 PERCENT. HOWEVER...THOUGH WINDS ARE
EXPECTED TO BE NEAR 20 MPH...IT IS UNCERTAIN IF THE SURFACE TROUGH
WHICH RESULTED IN LIGHTER WINDS TODAY WILL BE A FACTOR TOMORROW AS
WELL. THOUGH MINIMUM RELATIVE HUMIDITY VALUES WILL DROP BELOW 20
THROUGH THE REMAINDER OF THE WEEK...AS WE SEE A DRIER PATTERN...NO
ADDITIONAL ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED
AT THIS TIME AS WINDS SHOULD BE LIGHT.
JOHNSON
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
08/11
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
327 PM EDT MON JUN 24 2013
.SYNOPSIS...
A TYPICAL SUMMER PATTERN CONTINUES WITH HIGH PRESSURE SITUATED
ACROSS THE SOUTHEAST AND SOUTHWEST FLOW KEEPING US WARM AND
HUMID WITH A DAILY THREAT OF SHOWERS AND STORMS THROUGH AT LEAST
MIDWEEK. A COLD FRONT WILL APPROACH THE REGION FROM THE NORTHWEST
LATE IN THE WEEK WITH MORE WIDESPREAD SHOWERS AND THUNDERSTORMS
LIKELY BY THURSDAY OR FRIDAY. THE FRONT LOOKS TO SLOW DOWN
CROSSING THE REGION OVER THE WEEKEND KEEPING SHOWERS AND STORMS
AROUND INTO AT LEAST SUNDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 230 PM EDT MONDAY...
WIDELY SCATTERED CONVECTION LOOKS TO CONTINUE ACROSS THE AREA
INTO THIS EVENING WITH PERHAPS A GRADUAL MIGRATION OF STORM
DEVELOPMENT OFF INTO THE NE/EASTERN COUNTIES WHERE BETTER
HEATING/INSTAB EXISTS AND A WEAK VORT TAIL WILL BE PASSING
ACROSS. THIS SIMILAR TO THE LATEST HRRR AND RAP SOLUTIONS WHICH
END UP WITH MOST COVERAGE OVER THE EAST OR SE AS THE WEAK CAP
ALOFT LOOKS TO GIVE WAY BEFORE LOSS OF HEATING. THINK WESTERN
AREAS MAY ACTUALLY SEE LESS GIVEN CLOUDS AND LOWER CAPE DUE TO
EARLIER SHRA SO TRIMMING POPS BACK A BIT FAR WEST EARLY ON WHILE
GOING WITH CONTINUED SCATTERED COVERAGE EAST. AGAIN WITH LACK
OF MUCH UPPER SUPPORT...EXPECT COVERAGE TO BECOME MORE ISOLATED
THIS EVENING WITH SOME FOG DEVELOPING VALLEYS AND WHERE DOWNPOURS
OCCURRED EARLIER. SOME ADDED SHRA THEN POSSIBLE AGAIN LATER
TONIGHT AS THE WEAK UPSTREAM VORT OVER KY SLIDES EAST AND DAMPENS
OUT ACROSS THE MOUNTAINS BY MORNING. SINCE GUIDANCE NOT LATCHING
ONTO MUCH LIFT WITH THIS FEATURE...WILL ONLY KEEP A TOKEN POP IN
FAR WEST FOR NOW AND LEAVE ELSW DRY LATER ON.
LOWS A BIT MORE WARM/MUGGY OVERNIGHT WITH TEMPS ONLY DROPPING
INTO THE MID 60S TO AROUND 70 WITH LOW 60S ONLY IN THE DEEPEST
VALLEYS.
5H WEAKNESS SLOWS ACROSS THE REGION ON TUESDAY WITH LOW LEVEL
WESTERLY FLOW TURNING MORE SW DURING THE AFTERNOON AS THE EASTERN
LEE TROF SLIDES FARTHER EAST. FCST SOUNDINGS ARE EVEN MORE MOIST
THAN TODAY WITH LITTLE CAP ALTHOUGH QUESTIONS WITH THE DEGREE OF
ORGANIZATION UNDER SUCH WEAK FLOW ALOFT. THINK ENOUGH THETA-E
SUPPORT TO AT LEAST HAVE ANOTHER ROUND OF SCATTERED POPS BUT
WITH MORE MULTICELL CLUSTERS POSSIBLE ESPLY MOUNTAINS WHERE WILL
BE A BIT COOLER ALOFT. LOOKS LIKE WEAK DOWNSLOPE MAY CAUSE A
DELAY IN TSRA EAST WITH MORE OF A LATE AFTERNOON SCENARIO AIDED
BY WESTERN COVERAGE MOVING EAST AFTER SOME LOW LEVEL BACKING HAS
DEVELOPED. FOR NOW WILL CONTINUE TREND OF HIGH CHANCE POPS BUT MAY
NEED TO GO HIGHER LATER PENDING UPDATED MODEL SOLUTIONS.
WITH 85H TEMPS A COUPLE DEGREES WARMER AND LIGHT WEST
WINDS...WOULD EXPECT HIGHS TO TOP 90 SE...AND HEAD WELL INTO THE
80S OUTSIDE OF THE HIGHER ELEVATIONS...CLOSER TO THE WARMER MAV
MOS.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 305 PM EDT MONDAY...
ZONAL FLOW AND A LEE TROUGH WILL START THE WEATHER PATTERN
TUESDAY NIGHT. THIS PATTERN WILL HAVE FADING DIURNAL
THUNDERSTORMS IN THE EVENING WITH PATCHY FOG DEVELOPING WHERE IT
RAINED DURING THE DAY TUESDAY. THE LEE TROUGH WILL HELP INITIATE
SCATTERED CONVECTION AGAIN WEDNESDAY AFTERNOON. PWATS ARE AROUND
NORMAL WITH MOISTURE ADVECTION COMING FROM THE SOUTHWEST. WITH
MOISTURE AND HEATING...A FEW STORMS COULD BE STRONG TO SEVERE
WEDNESDAY AFTERNOON AND EVENING. CORFIDI VECTORS ARE ALSO VERY
WEAK TUESDAY AND WEDNESDAY. STORMS WILL BE SLOW MOVING/ANCHORED
CREATING A VERY LOCALIZED FLASH FLOOD THREAT. ONCE AGAIN...SHOWERS
WILL FADE AFTER SUNSET WITH A FEW HANGING ON UNTIL MIDNIGHT WITH
LINGER INSTABILITIES.
TEMPERATURES WILL RUN WARMER THAN NORMAL THROUGH THE PERIOD BY 5
DEGREES OR SO. OVERNIGHT LOWS GENERALLY IN THE 60S WITH DAY TIME
HIGHS IN THE 80S...LOW 90S IN THE PIEDMONT.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 230 PM EDT MONDAY...
AN OCCLUDED LOW WILL WORKS ITS WAY TO THE EAST THURSDAY FROM THE
GREAT LAKES TO LAKE ERIE. WITH A LEE TROUGH IN THE EAST AND AN
APPROACHING WEAK FRONT/UPPER LEVEL TROUGH FROM THE WEST...MORE
AREAL COVERAGE OF CONVECTION IS EXPECTED THURSDAY AFTERNOON. HAIL
AND STRAIGHT LINE WINDS WILL BE THE PRIMARY THREAT. PWATS
INCREASE TO 2 STANDARD DEVIATION ABOVE NORMAL...MAKING FLASH
FLOOD A THREAT AS WELL.
THE FRONT AND LEE TROUGH BECOME ONE ON FRIDAY. CONVERGENCE IN
THIS SURFACE TROUGH SHOULD GENERATE STRONG CONVECTION...MAINLY
OVER THE PIEDMONT. NOT MUCH OF AN AIRMASS CHANGE AS THE FRONT
JOINS THE LEE TROUGH...THEREFORE CAN NOT RULE OUT THUNDERSTORMS
ACROSS THE MOUNTAINS AND FOOTHILLS FRIDAY.
A STRONGER FRONT IS EXPECTED TO APPROACH THE REGION ON SATURDAY.
THIS FRONT WILL BRING ANOTHER ROUND OF AREA-WIDE CHANCES OF
STRONG TO SEVERE THUNDERSTORMS. LOW CONFIDENCE ON FRONTAL TIMING
WITH A STRONG BLOCKING RIDGE IN THE WESTERN ATLANTIC THROUGH THE
PERIOD. EVEN IF THE FRONT TRACKS ACROSS THE AREA SATURDAY...RAIN
CHANCES WILL STILL EXIST SUNDAY AND MONDAY. THE BLOCKING RIDGE
COULD STALL THE FRONT INLAND OF THE EAST COAST...POSSIBLY
INTO THE PIEDMONT. WAVES WILL TRACK ALONG THE FRONT SUNDAY AND
MONDAY KEEPING THE CHANCE OF RAIN INTO EARLY NEXT WEEK.
TEMPERATURES WILL REMAIN WARMER THAN NORMAL INTO THE WEEKEND.
THE MORE AREAL COVERAGE OF SHOWERS DURING A GIVEN DAY WILL KEEP
TEMPERATURES CLOSER TO NORMAL.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
AS OF 110 PM EDT MONDAY
SCATTERED SHRA/TSRA CLUSTERS HAVE DEVELOPED ACROSS THE MOUNTAINS
EARLY THIS AFTERNOON ALONG THE PERIPHERY OF THE EARLIER MID DECK.
EXPECT THIS COVERAGE TO SLOWLY INCREASE WHILE PUSHING SLOWLY EAST
UNTIL FADING OUT EARLY THIS EVENING. HOWEVER STILL LOW CONFIDENCE
IN WHETHER OR NOT ANY TAF LOCATION WILL EXPERIENCE A SHRA DIRECTLY
BUT ENOUGH OF A THREAT TO INCLUDE A VCTS MENTION AT MOST SPOTS
WITH A PERIOD OF PREVAILING MVFR VSBY AT KBLF THROUGH THE
AFTERNOON. ANY MORE ORGANIZED SHOWER OR STORM CLUSTER THAT DOES
COME IN THE VICINITY OF THE TAF LOCATIONS MAY RESULT IN A PERIOD
OF BRIEF IFR CIGS/VSBY WHICH WILL TEMPO AS NEEDED.
MOST OF THE DAYTIME ACTIVITY SHOULD DISSIPATE AFTER SUNSET.
HOWEVER...THERE MAY BE SOME LINGERING SHOWER ACTIVITY WEST OF THE
MTNS ASSOCIATED WITH A WEAK MID LEVEL WAVE THAT IS MOVING EAST
ACROSS KENTUCKY. THIS SHOWER ACTIVITY MAY REACH KBLF AFTER
MIDNIGHT TONIGHT...BUT WILL KEEP OUT OF THE TAF FCST ATTM UNTIL
CAN BE MORE CERTAIN OF TIMING GIVEN QUICK DISSIPATION OF SHRA OF
LATE WITH LOSS OF HEATING. OTRW APPEARS FOG WILL BE A BIT MORE
WIDESPREAD OVERNIGHT GIVEN HIGHER DEWPOINTS AND MORE RESIDUAL
MOISTURE FROM AFTERNOON CONVECTION. EXPECT A PERIOD OF MVFR AT
MOST SITES EXCLUDING KROA...AND PERHAPS KBLF WHILE KLWB/KBCB LOOK
TO DROP INTO IFR LEVELS WITH SOME LOW STRATUS AROUND LATE TONIGHT.
LOW CONDITIONS SHOULD IMPROVE BY MID MORNING TUE...FOLLOWED BY
MORE SCTD/BKN VFR CU AND DEVELOPING SHRA/TSRA AS A WEAK IMPULSE
ALOFT PUSHES ACROSS. WEST WIND MAY CAUSE LESS COVERAGE EARLY ON
WITH MORE ORGANIZED TSRA POSSIBLE BEYOND THE VALID TAF PERIOD
TUE AFTERNOON.
.AVIATION EXTENDED...
WE WILL BE TRANSITIONING FROM A FLAT UPPER RIDGE TO A BLOCKY PATTERN
WITH AN EASTERN CONUS TROF/WESTERN CONUS RIDGE THROUGH THE
EXTENDED PERIOD. SFC HIGH OFF THE EAST COAST WILL KEEP WARM AND
MOIST AIR OVER THE REGION WITH A SERIES OF WAVES RIPPLING THROUGH
THE FLOW. THIS WILL PRIMARILY LEAVE US WITH AN UNSTABLE AIRMASS IN
A WEAKLY FORCED CONVECTIVE ENVIRONMENT THROUGH MIDWEEK. EXPECT A
DIURNAL PATTERN OF CONVECTION WITH VFR IN THE MORNING...THEN MVFR
WITH SHRA/TSRA IN THE AFTERNOON AND EVE...THEN POSSIBLE IFR WITH
NOCTURNAL FOG/STRATUS. LOOKING LIKE LATTER PORTION OF THE WEEK
WILL BE MORE ACTIVE. AS THE PATTERN FINALLY BECOMES MORE AMPLIFIED
AND THE ERN TROF SINKS DOWN INTO THE REGION...IT SHOULD PUSH A
COLD FRONT THROUGH TOWARD THE END OF THE WEEK...WITH BETTER
AVIATION CONDITIONS THEREAFTER. EXPECT WINDS TO REMAIN ON THE
LIGHT SIDE UNTIL THURSDAY WHEN LOW LEVEL WIND FIELD BEGINS TO
INCREASE AHEAD OF APPROACHING COLD FRONT. BEST COVERAGE OF STORMS
LOOKS TO BE ON THURSDAY AS WELL WITH A POSSIBLE LINE AHEAD OF THE
FRONT THRUSDAY AFTERNOON/EVENING.
&&
.EQUIPMENT...
AS OF 1225 PM EDT SUNDAY...
DANVILLE ASOS VISIBILITY SENSOR REMAINS INOP AND EXPECTED TO BE
FIXED TUESDAY OR WEDNESDAY OF THIS WEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/WP
NEAR TERM...JH
SHORT TERM...RCS
LONG TERM...RCS
AVIATION...JH/PM
EQUIPMENT...WP
AREA FORECAST DISCUSSION
NWS SPOKANE WA
444 AM PDT Mon Jun 24 2013
.SYNOPSIS...
A wet pattern will continue across the Inland Northwest through
mid week...with frequent showers and scattered thunderstorms
common. The weather the second half of the week will be
dramatically different as a warming and drying trend quickly
develops by late week. Summer-like temperatures will be possible
by the weekend.
&&
.DISCUSSION...
Today and tonight...Offshore low pressure buttressed against
interior ridging with an axis positioned over Eastern Montana
is allowing a moist and very dynamic southwest flow of moisture
and energy to continue to pass through Eastern Washington and
Northern Idaho. Negatively tilted shortwaves ejecting up through
this flow have enough energy to merit not only high pops and
moderate QPF for rain but also the mention of thunderstorms.
Recent HRRR model runs hint at once the elevated forced convective
showers and thunderstorms pass associated with the largest
baroclinic negatively tilted frontal zone passing through right
now there will be not so much a break in the activity but a
decreasing trend between the time when the elevated convection
either exits into Canada or erodes/weakens some along its back
trailing edges and the time near 18Z and beyond where surface
based convection is expected to start filling in the breaks.
Therefore the forecast will remain cluttered with moderate to high
pops, QPF, along with some mention of thunderstorms that decreases
substantially with loss of daytime heating allowing the surface
based convection to subside...especially noted after 6Z tonight.
/Pelatti
Tues through Fri Nt: This four-day period will be the transition
period characterized by wet weather Tue and Wed, then by a rapid
warming and drying trend Thurs and Fri. The primary concern will
be how much pcpn will fall in the mtn zones of Nrn Wa, the Id
Panhandle and the East Slopes of the Cascades. Three-day model
guidance QPF is depositing (through about Wed) big ranges anywhere
from 0.60-1.50 inches for these zones... with the SREF the least
and the GFS the highest amnts. A complicating factor in our pcpn
amnt fcst is the number of quick-moving waves that track across
the Pac Nw through mid-week. There are at least four subtle
features (depending on the model), all of which contain a decent
SW moisture tap, with pwat values averaging around one inch. The
latest TPW loop shows a nearly SW-to-NE plume of 200% of normal
values aimed at Nrn Calif. Our waves should be able to tap into at
least 100-150% values. Adding to the complexity of the wide-
ranging rainfall amnts is the element of instability, especially
late afternoon. This will be the dominating factor that will
produce wide-ranging rainfall amnts over very short distances.
Streams that will be affected most will be those across NE WA and
the N Id Panhandle...especially where the recent heavy pcpn fell the
last couple weeks...as well as the Stehekin River near the Cascade
crest.bz
Saturday through Monday...A ridge of high pressure will build north
near the Inland Northwest, bringing with it drying conditions and
above normal temperatures. The extended models are consistent in
building a ridge into the region, but how amplified the ridge is
and its placement are still in question. The difference is
forecasting temperatures in the 90s to temperatures a little
"cooler" in the 80s. Previous forecasts had lowered temperatures
a tad on Saturday and did not see any reason to deviate from this.
Until a little better consistency occurs, the forecast will trend
to the ridge building into eastern Washington and the Idaho
panhandle a little more each day, and thus warming temperatures a
few degrees each day. Precipitation chances remain near nil,
except for early Saturday where a lingering shower or thunderstorm
may occur over Idaho panhandle. ty
&&
.AVIATION...
12Z TAFS: Negatively tilted trof passage keeps aviation area wet
and unsettled today with MVFR ceilings at most TAF sites. Some
improvement as far as decreasing showers and raising of ceilings
expected after 03Z Tuesday. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 67 53 66 52 73 54 / 90 80 80 50 20 10
Coeur d`Alene 66 55 66 52 73 53 / 100 80 80 50 20 20
Pullman 66 52 66 51 74 52 / 70 60 70 50 20 10
Lewiston 71 57 74 57 80 58 / 70 60 60 60 30 20
Colville 71 54 70 51 75 52 / 100 70 80 60 20 20
Sandpoint 66 54 67 51 71 52 / 100 80 90 60 30 20
Kellogg 63 52 63 51 69 52 / 80 80 80 50 30 20
Moses Lake 74 58 69 56 80 58 / 50 30 50 20 20 10
Wenatchee 74 57 69 57 79 60 / 50 30 50 20 20 10
Omak 73 56 70 53 77 54 / 70 50 60 30 20 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
224 AM PDT Mon Jun 24 2013
.SYNOPSIS...
A wet pattern will continue across the Inland Northwest through
mid week...with frequent showers and scattered thunderstorms
common. The weather the second half of the week will be
dramatically different as a warming and drying trend quickly
develops by late week. Summer-like temperatures will be possible
by the weekend.
&&
.DISCUSSION...
Today and tonight...Offshore low pressure buttressed against
interior ridging with an axis positioned over Eastern Montana
is allowing a moist and very dynamic southwest flow of moisture
and energy to continue to pass through Eastern Washington and
Northern Idaho. Negatively tilted shortwaves ejecting up through
this flow have enough energy to merit not only high pops and
moderate QPF for rain but also the mention of thunderstorms.
Recent HRRR model runs hint at once the elevated forced convective
showers and thunderstorms pass associated with the largest
baroclinic negatively tilted frontal zone passing through right
now there will be not so much a break in the activity but a
decreasing trend between the time when the elevated convection
either exits into Canada or erodes/weakens some along its back
trailing edges and the time near 18Z and beyond where surface
based convection is expected to start filling in the breaks.
Therefore the forecast will remain cluttered with moderate to high
pops, QPF, along with some mention of thunderstorms that decreases
substantially with loss of daytime heating allowing the surface
based convection to subside...especially noted after 6Z tonight.
/Pelatti
Tues through Fri Nt: This four-day period will be the transition
period characterized by wet weather Tue and Wed, then by a rapid
warming and drying trend Thurs and Fri. The primary concern will
be how much pcpn will fall in the mtn zones of Nrn Wa, the Id
Panhandle and the East Slopes of the Cascades. Three-day model
guidance QPF is depositing (through about Wed) big ranges anywhere
from 0.60-1.50 inches for these zones... with the SREF the least
and the GFS the highest amnts. A complicating factor in our pcpn
amnt fcst is the number of quick-moving waves that track across
the Pac Nw through mid-week. There are at least four subtle
features (depending on the model), all of which contain a decent
SW moisture tap, with pwat values averaging around one inch. The
latest TPW loop shows a nearly SW-to-NE plume of 200% of normal
values aimed at Nrn Calif. Our waves should be able to tap into at
least 100-150% values. Adding to the complexity of the wide-
ranging rainfall amnts is the element of instability, especially
late afternoon. This will be the dominating factor that will
produce wide-ranging rainfall amnts over very short distances.
Streams that will be affected most will be those across NE WA and
the N Id Panhandle...especially where the recent heavy pcpn fell the
last couple weeks...as well as the Stehekin River near the Cascade
crest.bz
Saturday through Monday...A ridge of high pressure will build north
near the Inland Northwest, bringing with it drying conditions and
above normal temperatures. The extended models are consistent in
building a ridge into the region, but how amplified the ridge is
and its placement are still in question. The difference is
forecasting temperatures in the 90s to temperatures a little
"cooler" in the 80s. Previous forecasts had lowered temperatures
a tad on Saturday and did not see any reason to deviate from this.
Until a little better consistency occurs, the forecast will trend
to the ridge building into eastern Washington and the Idaho
panhandle a little more each day, and thus warming temperatures a
few degrees each day. Precipitation chances remain near nil,
except for early Saturday where a lingering shower or thunderstorm
may occur over Idaho panhandle. ty
&&
.AVIATION...
06Z TAFS: Conditions will continue to deteriorate across the region
as a negatively tilted trough interacts with deep moisture over the
region to produce thickening and lowering ceilings with widespread
rain through about 16Z as the area of moisture moves from southwest to
northeast through the interior Pacific Northwest. Expect MVFR
ceilings at most TAF sites at times with improving conditions with
higher CIGS after 18Z Monday. TC
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 67 53 66 52 73 54 / 90 80 80 50 20 10
Coeur d`Alene 66 55 66 52 73 53 / 100 80 80 50 20 20
Pullman 66 52 66 51 74 52 / 70 60 70 50 20 10
Lewiston 71 57 74 57 80 58 / 70 60 60 60 30 20
Colville 71 54 70 51 75 52 / 100 70 80 60 20 20
Sandpoint 66 54 67 51 71 52 / 100 80 90 60 30 20
Kellogg 63 52 63 51 69 52 / 80 80 80 50 30 20
Moses Lake 74 58 69 56 80 58 / 50 30 50 20 20 10
Wenatchee 74 57 69 57 79 60 / 50 30 50 20 20 10
Omak 73 56 70 53 77 54 / 70 50 60 30 20 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
954 PM CDT TUE JUN 25 2013
NEW INFORMATION ADDED TO UPDATE SECTION
.UPDATE...
ISSUED AT 938 PM CDT TUE JUN 25 2013
PERSISTENT SHRA/TSRA ACTIVITY OVER THE SOUTHERN FOX VALLEY HAS
FINALLY DISSIPATED...AND LOCAL MESOANALYSIS SHOWS THAT THE LOW-
LEVEL CONVERGENCE THAT WAS SUPPORTING IT HAS SHIFTED EAST OF THE
REGION. WITH VERY WEAK LOW-LEVEL FLOW IN PLACE TONIGHT...AND THE
MAIN SYNOPTIC SCALE FRONTAL BOUNDARY STILL SET UP WELL TO OUR
SOUTH OVER IA AND NORTHERN IL...PROSPECTS ARE POOR FOR ADDITIONAL
CONVECTION OVERNIGHT. HAVE ONLY MAINTAINED LOW POPS OVER C/EC WI
OVERNIGHT...JUST IN CASE ISOLD STORMS DEVELOP. WITH PARTLY CLOUDY
SKIES AND LIGHT WINDS EXPECTED OVERNIGHT...HAVE ADDED PATCHY/AREAS
OF FOG FOR THE OVERNIGHT HOURS. LOCALLY DENSE FOG IS EXPECTED IN
THE RIVER VALLEYS AND ALONG THE LAKESHORE.
MADE SOME ADJUSTMENTS TO POPS ON WEDNESDAY TO SLOW DOWN THE
PROGRESSION OF PCPN...AND CONFINE LIKELY POPS TO JUST NC/C WI
DURING THE AFTERNOON. THINK WE`LL SEE SOME SUNSHINE IN THE
MORNING...WHICH COULD RESULT IN MORE INSTABILITY THAN WAS
PREVIOUSLY THOUGHT. DEEP LAYER SHEAR IS EXPECTED TO INCREASE
ACROSS OUR WSTRN COUNTIES LATE IN THE DAY...WHICH MAY SUPPORT
SVR TSTM POTENTIAL DURING THE LATE AFTERNOON/EARLY EVENING.
&&
.SHORT TERM...TONIGHT AND WEDNESDAY
ISSUED AT 255 PM CDT TUE JUN 25 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW EARLIER
CONVECTION ACROSS IOWA AND SOUTHERN WISCONSIN DISSIPATED/EXITED
EARLIER THIS AFTERNOON. TOUGH TO TELL WHERE THE OUTFLOW BOUNDARY
STALLED OUT...BUT AN ARCING LINE OF CLOUDS FROM NW IOWA TO MOLINE
TO NW OHIO COULD BE IT. REMNANT SHORTWAVE MOVING ACROSS SOUTHERN
MINNESOTA AND IOWA IS RELATIVE INACTIVE SO FAR THIS AFTERNOON...AS
IS MUCH OF THE STATE OF WISCONSIN. A FEW STORMS POPPED UP OVER
SOUTHERN WISCONSIN AND ALSO WILL NEED TO WATCH THE AREA OF CU OVER
NORTHERN WISCONSIN FOR SHOWER/TSTORM DEVELOP LATER THIS AFTERNOON.
ML CAPES ARE BUILDING TO AROUND 800 J/KG BUT NEED A LITTLE MORE
LIFT VIA LAKE BREEZES TO GET CONVECTION STARTED. AN AREA OVER FAR
NORTHERN WISCONSIN MIXED OUT...SO WILL SHIFT PRECIP CHANCES MAINLY
SOUTH OF VILAS COUNTY. THE NEXT AREA OF WEATHER IS MOVING ACROSS
THE PLAINS WHICH WILL ARRIVE TOMORROW. PRECIP CHANCES CONTINUE TO
BE THE MAIN FORECAST CONCERNS.
TONIGHT...WILL KEEP AN ISOLATED MENTIONED OF THUNDERSTORMS OVER
CENTRAL WISCONSIN AS WELL AS NORTHERN WISCONSIN UNTIL DIURNAL
INSTABILITY DIMINISHES. BY MID TO LATE EVENING...A LLJ WILL GET
CRANKING OVER THE CENTRAL PLAINS AHEAD OF THE NEXT LOW PRESSURE
SYSTEM. THE NAM/GFS/ECMWF ALL SUGGEST THAT THE NOSE OF THE LLJ WILL
POINT TOWARDS NORTHERN IOWA/SOUTHERN WISCONSIN/NORTHERN
ILLINOIS...WHICH IS THE REGION THAT HAS BEEN LIGHTING UP WITH STORMS
EACH OF THE PAST SEVERAL NIGHTS. DO NOT HAVE ANY REASON TO THINK
DIFFERENTLY THIS TIME...BUT DO HAVE WEAK ISENTROPIC ASCENT OCCURRING
OVER CENTRAL WISCONSIN THIS EVENING...THAT MOVES INTO NORTH-CENTRAL
AND EAST-CENTRAL WISCONSIN OVERNIGHT. WILL KEEP A SMALL CHANCE OF
STORMS OVERNIGHT. ANY SEVERE THREAT LOOKS TO REMAIN TO THE SOUTH
HOWEVER. ANOTHER MUGGY NIGHT WITH LOWS IN THE 60S.
WEDNESDAY...LOW PRESSURE OVER THE NORTHERN MISSISSIPPI VALLEY AT THE
START OF THE PERIOD WILL SHIFT SLOWLY EAST INTO WISCONSIN. MODELS
HAVE SLOWED DOWN THE PROGRESSION OF THIS LOW SOMEWHAT...SO WILL
DELAY THE LIKELY POPS UNTIL THE AFTERNOON. EVEN WITH THE SLOWER
ARRIVAL...AM ANTICIPATING PLENTY OF CLOUD COVER WHICH SHOULD REDUCE
SURFACE HEATING AND INSTABILITY. A SEVERE THREAT SEEMS TO LOW TO
MENTION AT THIS TIME THOUGH ANY STORMS COULD PRODUCE LOCALLY HEAVY RAINFALL.
.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY
ISSUED AT 255 PM CDT TUE JUN 25 2013
WHILE THE UPPER LEVEL WINDS ARE EXPECTED TO BECOME
NORTHWEST THURSDAY WHILE THE UPPER RIDGE BUILDS OVER THE WESTERN
STATES...IT WILL TAKE A WHILE BEFORE WE GET THE DRY WEATHER
USUALLY ASSOCIATED WITH NORTHWEST UPPER FLOW. THE REASON IS THAT
SEVERAL JET STREAKS ARE FORECAST TO ROTATE AROUND THE UPPER RIDGE
AND DIVE INTO THE GREAT LAKES TROUGH. THIS RESULTS IN THE
FORMATION OF AN ELONGATED UPPER TROUGH OR LOW OVER THE GREAT LAKES.
SEVERAL UPPER JETS SHOULD PROVIDE UPPER SUPPORT FOR PRECIPITATION
AT TIMES WHILE THERE IS RESIDUAL LOW LEVEL MOISTURE. SUNDAY AND
MONDAY LOOK TO BE THE DAYS WITH THE LEAST CHANCE OF RAIN ALONG
WITH COOL TEMPERATURES AND LOW DEW POINTS. LOOKS LIKE A WEAK UPPER
LEVEL LOW CONTINUES ACROSS THE AREA THROUGH THE MIDDLE OF NEXT
WEEK THOUGH THERE IS SOME INDICATION THAT IT WILL BEGIN TO EXIT ON
INDEPENDENCE DAY. NOT MUCH CONFIDENCE IN THE UPPER PATTERN THOUGH.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 635 PM CDT TUE JUN 25 2013
SMALL LINE OF SHRA/TSRA FROM OSH-SBM SHOULD GRADUALLY MOVE OUT OF
THE REGION EARLY THIS EVENING...WITH ONLY A SMALL CHANCE OF RAIN
OVER C/EC WI FOR THE REST OF THE NIGHT INTO WEDS MORNING. PARTLY
CLOUDY SKIES AND LIGHT WINDS WILL LIKELY LEAD TO SOME FOG
DEVELOPMENT LATE TONIGHT...WITH IFR VSBYS POSSIBLE AT ALL OF THE
TAF SITES...AND PERHAPS SOME LOCAL LIFR/VLIFR CONDITIONS. FOG/LOW
CLOUDS SHOULD MIX OUT EARLY ON WEDNESDAY MORNING. AN UPPER LEVEL
DISTURBANCE AND ASSOCIATED FRONTAL BOUNDARY SHOULD MOVE INTO NC/C
WI WEDS AFTERNOON...BRINGING SCT TSTMS TO RHI/AUW/CWA.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE.........KIECKBUSCH
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......KIECKBUSCH
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
923 PM CDT TUE JUN 25 2013
.UPDATE...
FORECAST KEY IS LIFT MECHANISM...OR LACK THERE OF. MOISTURE AND
INSTABILITY IN PLACE BUT 700 MB WINDS...WITH HIGHER WEST WINDS
MAINLY OVER NORTHERN ILLINOIS DECREASE TONIGHT TO ONLY AROUND 10
KNOTS OVER SOUTHERN WISCONSIN BY SUNRISE. SOME 850 MB MOISTURE
CONVERGENCE OVER THE FAR SOUTH AT 850 MB WITH SOUTHWEST WINDS
AROUND 20 KNOTS PUSHING IN TO THE FAR SOUTH...BUT THESE ALSO
DECREASE BY SUNRISE.
ONE 500 MB SHORTWAVE DIVES EAST/SOUTHEAST ACROSS NORTHERN ILLINOIS
BY SUNRISE...WITH A LOW TO MID LEVEL TROUGH OVER WISCONSIN
WEDNESDAY WITH WEAK WINDS.
CONCERN IS ANY STORMS THAT DO DEVELOP WOULD MOVE SLOW...AND WITH
70 DEW POINTS AND PRECIPITABLE WATER VALUES AROUND 1.5 INCHES...ANY
STORMS COULD PRODUCE HEAVY RAINFALL.
ALSO WITH THE LOW LEVEL TROUGH/LOW ON TUESDAY AND WEAK WINDS A HEAVY
RAIN EVENT WOULD BE POSSIBLE.
HOWEVER THINKING THIS IS MAINLY A CHANCE EVENT NOT LIKELY.
&&
.AVIATION/06Z TAFS/...
MAINLY VFR CONDITIONS BECOMING MVFR IN FOG WITH SOME MVFR/IFR CIGS
DURING THE EARLY TO MID MORNING DUE TO THE HIGH LOW LEVEL
MOISTURE.
A CHANCE OF THUNDERSTORMS WILL CONTINUE...BUT THE MORE ORGANIZED
STORMS ARE LIKELY TO BE SOUTH OF THE FORECAST AREA. WITH A LOW/MID
LEVEL TROUGH THE CHANCE OF THUNDERSTORMS WILL CONTINUE WEDNESDAY.
&&
.PREV DISCUSSION... /ISSUED 339 PM CDT TUE JUN 25 2013/
VERY SHORT TERM...TONIGHT AND WEDNESDAY.
TONIGHT - CONFIDENCE...LOW
MAIN CHALLENGE CENTERS ON CONVECTIVE TRENDS AS HAS BEEN THE CASE THE
LAST SEVERAL DAYS. AIR MASS DESTABILIZATION UNDERWAY WITH -11 LI/S
INTO SW CWA. CORRIDOR OF HIGH ML CAPE VALUES ALSO LOCATED THERE AS
WELL...WITH VALUES AS HIGH AS 3500 J/KG. SPC MONITORING FOR A WATCH
WITH BORDERLINE 30-35 KNOT 0-6 KM BULK SHEAR. WATER VAPOR/RUC
SHOWING A WEAK RIPPLE ACROSS SRN MN/NRN IA...MAY BE ENOUGH TO
ENHANCE THE ALREADY DEVELOPING CONVECTION NEAR KDBQ. AIR MASS IS
BECOMING INCREASINGLY MOIST AND UNSTABLE. 3 HOUR ML CAPE CHANGE
AROUND 1500 J/KG INTO THE SW CWA. DEEP LAYER MOISTURE FLUX
CONVERGENCE ALSO MAXIMIZED IN A CORRIDOR FROM NRN IL INTO SW WI.
SUPERCELL COMPOSITE MAXIMIZED SOUTH OF MADISON...THOUGH DRIVEN
LARGELY BY THE VERY HIGH CAPE VALUES. LATEST HRRR BLOWS UP THIS AREA
IN SW WI AND SPREADS IT ACROSS CWA THROUGH 01Z. LATER IN THE NIGHT
LOW LEVEL JET NOSE DISPLACED FURTHER SOUTH AND EAST AND HRRR
BLOSSOMS THINGS ACROSS IOWA AND THIS WOULD THEN HEAD
SOUTHEAST...POSSIBLY GRAZING FAR SRN WI. SURFACE FLOW IS ADVECTING
70 PLUS DEW POINT AIR INTO SRN WI. MODELS IN DECENT AGREEMENT IN
BRINGING A VORT MAX INTO IOWA AND TO JUST SOUTH OF WI BY 12Z.
VORTICITY ADVECTION WITH THIS FEATURE BRINGS BEST FORCING TO SW CWA
AROUND 6Z AND SPREADS IT ACROSS THE REST OF THE AREA BETWEEN 6-12Z.
AT THIS POINT TEND TO SIDE WITH THE MODELS SHOWING TSRA AFFECTING
THE CWA TONIGHT...ESPECIALLY THE SW 1/2...WITHIN AND NEAR THE
LI/CAPE GRADIENTS IN CONJUNCTION WITH THE APPROACHING UPPER FEATURE.
THE NAM AND SOME OF THE OTHER MESO MODELS SHOW NEXT TO NOTHING WHICH
IS A CONCERN IF THE 850 LEANS FURTHER SOUTH. FOR NOW WILL RETAIN THE
HEFTY POPS WE HAVE GOING AND HANG ONTO THE FLASH FLOOD WATCH.
WEDNESDAY - CONFIDENCE...MEDIUM
INFLUENCE OF THE 500 MILLIBAR WAVE SHIFTS EAST BY THE AFTERNOON AND
PER SWODY1 THE REAL FOCUS FOR THE HEFTY ACTIVITY SHIFTS INTO OH
VALLEY. PROGS SHOW BEST QPF IN THE MORNING WITH BETTER CWASP NUMBERS
INTO THE OHIO VALLEY. HOWEVER STILL SOME LINGERING TROUGHINESS SO
WILL KEEP POPS GOING INTO THE AFTERNOON. BUT ALL IN ALL THE 850 JET
INFLUENCE AND UPPER FORCING SHIFTS TO OUR SOUTH AND EAST EARLY IN
THE DAY.
SHORT TERM...WEDNESDAY NIGHT THROUGH FRIDAY.
WEDNESDAY NIGHT AND THURSDAY...FORECAST CONFIDENCE MEDIUM.
SHORT WAVE TROUGH MOVES OFF TO THE EAST WITH BETTER FORCING STAYING
MORE CLOSELY TIED TO THE VORT MAX/PV ANOMALY PASSING NE OF FORECAST
AREA WEDNESDAY NIGHT...WELL REFLECTED IN LAYER Q-VECTOR CONVERGENCE
AND ISENTROPIC OMEGA. HOWEVER LOW-LEVEL MOISTURE CONVERGENCE MOVES
ACROSS CWA WITH WEAK SURFACE TROUGH WITH LINGERING INSTABILITY IN
THE EVENING TO KEEP A CHANCE OF THUNDERSTORMS...TAPERING TO A SLIGHT
CHANCE OVERNIGHT.
HAVE CHANCE POPS THURSDAY AFTERNOON AS ANOTHER VORT MAX DROPS SE
THROUGH THE STATE...WITH SLIGHTLY STEEPENING MID-LEVEL LAPSE RATES
LEADING TO PEAK HEAT OF THE DAY INSTABILITY.
THURSDAY NIGHT AND FRIDAY...FORECAST CONFIDENCE LOW TO MEDIUM.
300 MB SPEED MAX BRINGS A SHORT WAVE TROUGH OF VARYING STRENGTH
DEPENDING ON MODEL INTO THE REGION WITH DCVA-DRIVEN PCPN REACHING
THE NORTH THURSDAY NIGHT WITH THE BETTER CHANCE ACROSS THE REST OF
THE CWA FRIDAY.
LONG TERM...FRIDAY NIGHT THROUGH TUESDAY. FORECAST CONFIDENCE LOW.
UNSETTLED PERIOD WITH UPPER TROUGH NOW RETROGRADING FARTHER WEST
THAN PREVIOUS DAYS AND SETTLING OVER THE WESTERN GREAT LAKES THROUGH
THE REMAINDER OF THE PERIOD. GFS HAS A DRIER LOOK THAN ECMWF AS IT
DIGS AN OPEN WAVE WHILE ECMWF KEEPS A CLOSED LOW RIGHT OVER THE
STATE. WE MAY BE GETTING RID OF THE HEAVY RAINS/SEVERE WITH THE EXIT
OF THE MOIST AIR MASS...BUT ENOUGH INSTABILITY AND WEAK FORCING WITH
VORT MAXES MOVING THROUGH THE TROUGH TO KEEP AT LEAST SLIGHT CHANCES
IN FOR MUCH OF THE EXTENDED...THOUGH BLENDED GUIDANCE BRINGS LESSER
CHANCES IN FOR EARLY NEXT WEEK. AT OR BELOW NORMAL TEMPERATURES ARE
EXPECTED.
AVIATION/00Z TAFS/...AS HAS BEEN THE CASE THE LAST COUPLE OF DAYS
CEILINGS/VSBYS WILL BE DRIVEN BY CONVECTIVE EVENTS. EXPECTING
ADDITIONAL DEVELOPMENT AS THE NIGHT WEARS ALONG. 500 MILLIBAR
SHORTWAVE APPROACHES AND INTERACTS WITH INCREASINGLY UNSTABLE
AIRMASS. INFLUENCE OF THIS SHORTWAVE WILL CONTINUE INTO WEDNESDAY
MORNING...BEFORE BEST FORCING SHIFTS INTO THE OHIO VALLEY.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...FLASH FLOOD WATCH UNTIL 7 AM CDT WEDNESDAY FOR WIZ046-047-056-
057-062-063-067>070.
LM...NONE.
&&
$$
UPDATE...HENTZ
TONIGHT/WEDNESDAY AND AVIATION/MARINE...COLLAR
WEDNESDAY NIGHT THROUGH TUESDAY...REM
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
640 PM CDT TUE JUN 25 2013
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND WEDNESDAY
ISSUED AT 255 PM CDT TUE JUN 25 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW EARLIER
CONVECTION ACROSS IOWA AND SOUTHERN WISCONSIN DISSIPATED/EXITED
EARLIER THIS AFTERNOON. TOUGH TO TELL WHERE THE OUTFLOW BOUNDARY
STALLED OUT...BUT AN ARCING LINE OF CLOUDS FROM NW IOWA TO MOLINE
TO NW OHIO COULD BE IT. REMNANT SHORTWAVE MOVING ACROSS SOUTHERN
MINNESOTA AND IOWA IS RELATIVE INACTIVE SO FAR THIS AFTERNOON...AS
IS MUCH OF THE STATE OF WISCONSIN. A FEW STORMS POPPED UP OVER
SOUTHERN WISCONSIN AND ALSO WILL NEED TO WATCH THE AREA OF CU OVER
NORTHERN WISCONSIN FOR SHOWER/TSTORM DEVELOP LATER THIS AFTERNOON.
ML CAPES ARE BUILDING TO AROUND 800 J/KG BUT NEED A LITTLE MORE
LIFT VIA LAKE BREEZES TO GET CONVECTION STARTED. AN AREA OVER FAR
NORTHERN WISCONSIN MIXED OUT...SO WILL SHIFT PRECIP CHANCES MAINLY
SOUTH OF VILAS COUNTY. THE NEXT AREA OF WEATHER IS MOVING ACROSS
THE PLAINS WHICH WILL ARRIVE TOMORROW. PRECIP CHANCES CONTINUE TO
BE THE MAIN FORECAST CONCERNS.
TONIGHT...WILL KEEP AN ISOLATED MENTIONED OF THUNDERSTORMS OVER
CENTRAL WISCONSIN AS WELL AS NORTHERN WISCONSIN UNTIL DIURNAL
INSTABILITY DIMINISHES. BY MID TO LATE EVENING...A LLJ WILL GET
CRANKING OVER THE CENTRAL PLAINS AHEAD OF THE NEXT LOW PRESSURE
SYSTEM. THE NAM/GFS/ECMWF ALL SUGGEST THAT THE NOSE OF THE LLJ WILL
POINT TOWARDS NORTHERN IOWA/SOUTHERN WISCONSIN/NORTHERN
ILLINOIS...WHICH IS THE REGION THAT HAS BEEN LIGHTING UP WITH STORMS
EACH OF THE PAST SEVERAL NIGHTS. DO NOT HAVE ANY REASON TO THINK
DIFFERENTLY THIS TIME...BUT DO HAVE WEAK ISENTROPIC ASCENT OCCURRING
OVER CENTRAL WISCONSIN THIS EVENING...THAT MOVES INTO NORTH-CENTRAL
AND EAST-CENTRAL WISCONSIN OVERNIGHT. WILL KEEP A SMALL CHANCE OF
STORMS OVERNIGHT. ANY SEVERE THREAT LOOKS TO REMAIN TO THE SOUTH
HOWEVER. ANOTHER MUGGY NIGHT WITH LOWS IN THE 60S.
WEDNESDAY...LOW PRESSURE OVER THE NORTHERN MISSISSIPPI VALLEY AT THE
START OF THE PERIOD WILL SHIFT SLOWLY EAST INTO WISCONSIN. MODELS
HAVE SLOWED DOWN THE PROGRESSION OF THIS LOW SOMEWHAT...SO WILL
DELAY THE LIKELY POPS UNTIL THE AFTERNOON. EVEN WITH THE SLOWER
ARRIVAL...AM ANTICIPATING PLENTY OF CLOUD COVER WHICH SHOULD REDUCE
SURFACE HEATING AND INSTABILITY. A SEVERE THREAT SEEMS TO LOW TO
MENTION AT THIS TIME THOUGH ANY STORMS COULD PRODUCE LOCALLY HEAVY RAINFALL.
.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY
ISSUED AT 255 PM CDT TUE JUN 25 2013
WHILE THE UPPER LEVEL WINDS ARE EXPECTED TO BECOME
NORTHWEST THURSDAY WHILE THE UPPER RIDGE BUILDS OVER THE WESTERN
STATES...IT WILL TAKE A WHILE BEFORE WE GET THE DRY WEATHER
USUALLY ASSOCIATED WITH NORTHWEST UPPER FLOW. THE REASON IS THAT
SEVERAL JET STREAKS ARE FORECAST TO ROTATE AROUND THE UPPER RIDGE
AND DIVE INTO THE GREAT LAKES TROUGH. THIS RESULTS IN THE
FORMATION OF AN ELONGATED UPPER TROUGH OR LOW OVER THE GREAT LAKES.
SEVERAL UPPER JETS SHOULD PROVIDE UPPER SUPPORT FOR PRECIPITATION
AT TIMES WHILE THERE IS RESIDUAL LOW LEVEL MOISTURE. SUNDAY AND
MONDAY LOOK TO BE THE DAYS WITH THE LEAST CHANCE OF RAIN ALONG
WITH COOL TEMPERATURES AND LOW DEW POINTS. LOOKS LIKE A WEAK UPPER
LEVEL LOW CONTINUES ACROSS THE AREA THROUGH THE MIDDLE OF NEXT
WEEK THOUGH THERE IS SOME INDICATION THAT IT WILL BEGIN TO EXIT ON
INDEPENDENCE DAY. NOT MUCH CONFIDENCE IN THE UPPER PATTERN THOUGH.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 635 PM CDT TUE JUN 25 2013
SMALL LINE OF SHRA/TSRA FROM OSH-SBM SHOULD GRADUALLY MOVE OUT OF
THE REGION EARLY THIS EVENING...WITH ONLY A SMALL CHANCE OF RAIN
OVER C/EC WI FOR THE REST OF THE NIGHT INTO WEDS MORNING. PARTLY
CLOUDY SKIES AND LIGHT WINDS WILL LIKELY LEAD TO SOME FOG
DEVELOPMENT LATE TONIGHT...WITH IFR VSBYS POSSIBLE AT ALL OF THE
TAF SITES...AND PERHAPS SOME LOCAL LIFR/VLIFR CONDITIONS. FOG/LOW
CLOUDS SHOULD MIX OUT EARLY ON WEDNESDAY MORNING. AN UPPER LEVEL
DISTURBANCE AND ASSOCIATED FRONTAL BOUNDARY SHOULD MOVE INTO NC/C
WI WEDS AFTERNOON...BRINGING SCT TSTMS TO RHI/AUW/CWA.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......KIECKBUSCH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
405 PM CDT MON JUN 24 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 304 PM CDT MON JUN 24 2013
AT 3 PM...A SQUALL LINE WAS MOVING EAST THROUGH EAST-CENTRAL
AND SOUTHEAST IOWA. THIS LINE HAS WIPED OUT MUCH OF THE
INSTABILITY THAT MANY OF 24.00Z AND 24.06Z MODELS WERE FORECASTING
TO MOVE INTO NORTHEAST IOWA...SOUTHEAST MINNESOTA...AND SOUTHWEST
AND CENTRAL WISCONSIN TONIGHT. EVEN SOME OF THE 24.12Z
DETERMINISTIC MODELS WERE NOT HANDLING THIS LINE WELL...SO THEY ARE
TOO HIGH ON THEIR CAPES ACROSS IOWA. IN ADDITION...THIS LINE ALSO
DISRUPTED THE 925 MB AND 850 MB MOISTURE TRANSPORT INTO THE
REGION. AS A RESULT...THE HEAVY RAIN THREAT FOR THIS EVENING LOOKS
MUCH LESS THAN WHAT IT WAS LOOKING LIKE EARLIER THIS MORNING.
FOR OVERNIGHT...THERE IS A LOT OF UNCERTAINTY ON HOW THIS PERIOD
IS GOING TO MATERIALIZE. THE 24.12Z NAM WHICH HAD A SLIGHTLY
BETTER HANDLE ON THE SQUALL LINE PUSHED AN OUTFLOW BOUNDARY SOUTH
TO THE MISSOURI AND IOWA BORDER...THUS ITS BEST MOISTURE
TRANSPORT IS FOCUSED MUCH FURTHER SOUTH. THE 925 MB MOISTURE
TRANSPORT HAS SHIFTED TOWARD SOUTHERN IOWA. IF THIS VERIFIES...
MUCH OF THE PRECIPITATION WOULD REMAIN SOUTH OF THE AREA FOR THIS
TIME PERIOD. EVEN THE LATEST RAP IS LEANING TOWARD THIS SCENARIO
TOO. MEANWHILE BOTH THE ECMWF AND GEM MODELS SUGGEST THAT AS THE
SHORT WAVE IN THE SOUTHERN PLAINS MOVES NORTHEAST INTO THE
SOUTHERN PLAINS...THE 850 MB MOISTURE TRANSPORT SHIFTS BACK
NORTHWARD TOWARD THE AREA TOWARD SUNRISE. IF THIS SCENARIO
VERIFIES...THERE COULD BE A POTENTIAL FOR THE REDEVELOPMENT OF
SHOWERS AND THUNDERSTORMS LATE TONIGHT. WITH ITS PRECIPTABLE WATER
VALUE CLOSE TO 2.00 INCHES AND WARM CLOUD LAYER DEPTHS UP TO
4.5 KM...THERE WOULD BE THE POTENTIAL FOR HEAVY RAIN. WITH SO MANY
DIVERSE MODEL SOLUTIONS...OPTED TO LOWER THE PRECIPITATION CHANCES
SOME AND ALSO SHIFTED THE HIGHER CHANCES TO LATER IN THE NIGHT.
HOPEFULLY...THE 24.00Z MODELS WILL BE BETTER AT RESOLVING THE
STABLE LAYER THAT WAS LEFT IN THE WAKE OF THE SQUALL LINE.
ON TUESDAY...EXPECT THE 925 MB AND 850 MB MOISTURE TRANSPORT TO
INCREASE ACROSS IOWA. HOWEVER THERE IS SOME UNCERTAINTY HOW FAR
NORTH THIS OCCUR. THE 24.18Z NAM AND 24.12Z GFS WOULD SUGGEST
THAT THE HEAVIEST RAIN WOULD FALL ACROSS CENTRAL IOWA. MEANWHILE
THE 24.12Z ECMWF AND GEM WOULD SUGGEST THAT THE HEAVIEST RAIN WOULD
FALL SOUTH OF INTERSTATE 90. WITH THE INITIAL CONDITIONS SO
MUDDLED...CONFIDENCE IS NOT THAT HIGH.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 304 PM CDT MON JUN 24 2013
ON TUESDAY NIGHT...MUCH OF THIS TIME PERIOD REMAINS UNCLEAR DUE
TO UNCERTAINTIES ON WHERE THE BOUNDARIES WILL END UP FROM TONIGHT
AND WHERE THUNDERSTORMS DEVELOP ON TUESDAY. THE GEM AND ECMWF
HAVE THEIR MESOSCALE CONVECTIVE COMPLEXES MOVING ALONG AND SOUTH
OF THE INTERSTATE 94 CORRIDOR. MEANWHILE THE GFS AND NAM SUGGEST
THAT THE MESOSCALE CONVECTIVE COMPLEX WILL DEVELOP ACROSS
IOWA...AND THEN MOVES IT NORTHEAST WITH THE SHORT WAVE INTO THE
FORECAST AREA. WITH WARM CLOUD LAYER DEPTHS OVER 4 KM AND
PRECIPITABLE WATER VALUES AROUND 2 INCHES. THERE WILL BE THE
POTENTIAL FOR SOME FLASH FLOODING.
ON WEDNESDAY AND WEDNESDAY EVENING...ADDITIONAL SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE ACROSS THE AREA AS THE LOW PRESSURE
AREA MOVES EAST ACROSS THE AREA. PRECIPITABLE WATER VALUES SLOWLY
DROP TO AROUND 1.60 INCHES AND THE WARM CLOUD LAYER DEPTHS FALL
INTO THE 3 TO 3.5 KM RANGE. WHILE THERE WILL BE THE POTENTIAL FOR
SOME HEAVY RAIN...THE AMOUNTS LOOK TO BE MUCH LESS THAN WHAT THEY
ARE FROM TONIGHT INTO TUESDAY NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 129 PM CDT MON JUN 24 2013
PERIODS OF TSRA WILL OCCUR THROUGH ABOUT 00Z. THIS MAY NEED TO BE
EXTENDED IN THE TAF SITES...WILL MONITOR...AS 18Z TAFS HAVE 2
HOURS OF TEMPO TSRA.
MASSIVE CONVECTIVE COMPLEX ACROSS IA HAS REALLY IMPACTED TSRA
FORECAST FOR THE OVERNIGHT HOURS. WAS THINKING THAT A MASSIVE RAIN
EVENT WAS IN PLACE BUT WITH THE IA CONVECTION...MANY OF THE GOOD
SET UP PARAMETERS ARE NOT AS FAVORABLE ANY LONGER OVERNIGHT. LATER
FORECASTS MAY REMOVE THE TSRA TO LESSER HOURS OR IMPACT. CEILINGS
WILL ALSO BE VERY DIFFICULT WITH MESSY...UNORGANIZED PATTERN
THROUGH THE PERIOD.
CONFIDENCE IS LOW IN THE TAF BEYOND 4-5 HOURS.
&&
.HYDROLOGY...
ISSUED AT 304 PM CDT MON JUN 24 2013
WITH A WIDE VARIETY OF SOLUTIONS IN THE 24.12Z AND 24.18Z
MODELS...CONFIDENCE HAS LOWERED ON THE THREAT FOR FLASH FLOODING
TONIGHT. HOWEVER WITH MANY RIVERS REMAINING EITHER HIGH OR ARE
FLOODING ACROSS NORTHEAST IOWA AND SOUTHWEST WISCONSIN. CONFIDENCE
WAS NOT HIGH ENOUGH TO CANCEL THE FLASH FLOOD WATCH.
LOOKING AHEAD TO TUESDAY AND TUESDAY NIGHT...SOME MODELS SUGGEST
THAT HEAVY RAIN COULD FALL SOUTH OF INTERSTATE 94. MEANWHILE OTHER
MODELS HINT THAT THE HEAVIEST PRECIPITATION WILL REMAIN SOUTH OF
THE FORECAST AREA. WITH SUCH DIVERSE SPREADS IN THE MODELS...OPTED
NOT TO EXTEND THE FLASH FLOOD WATCH INTO TUESDAY NIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR WIZ032>034-041>044-
053>055-061.
MN...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR MNZ079-086>088-
094>096.
IA...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR IAZ008>011-018-019-
029-030.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...BAUMGARDT
HYDROLOGY...BOYNE
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
334 PM CDT MON JUN 24 2013
.VERY SHORT TERM...TONIGHT AND TUESDAY.
TONIGHT - CONFIDENCE...LOW
EXPECTING A WEAKENED VERSION OF IOWA COMPLEX TO TRAVERSE ACROSS
THE CWA LATER THIS AFTERNOON AND EARLY EVENING. STRONGEST PORTION
OF IOWA COMPLEX WILL LIKELY RIDE THE MLCAPE GRADIENT IN NORTHERN
IL PER SPC MESO ANALYSIS...BUT SOME INCREASE INSTABILITY SNEAKING
BACK NORTH TOWARDS THE SRN COUNTIES. IN FACT 3 HOURLY MLCAPE
CHANGE WHILE GREATEST IN NRN IL...DOES SHOW AN AXIS INTO THE FAR
SOUTH. THIS CLOSE ENOUGH CALL IN THE SOUTHERN TIER OF COUNTIES FOR
THE SVR WATCH FROM SPC. LIKE LAST NIGHT THE MAIN CHALLENGE IS THE
DEGREE AND LOCATION OF REDEVELOPMENT BECOMES THE KEY QUESTION.
GETTING MODEL SOLUTIONS ALL OVER THE MAP FROM HEAVY RAINS...TO
SCATTERED DEVELOPMENT TO NEXT TO NOTHING. MODELS CONSENSUS OF 850
MILLIBAR JET CORE LOOKS VERY SIMILAR TO WHERE WE NOTICED IT SUNDAY
PROGGD FOR 12Z THIS MORNING. AND GIVEN WHERE ONGOING CONVECTION IS
LAYING ITSELF OUT HAVE SOME CONCERN THAT IT MAY BE ANOTHER
GLANCING SHOT ONCE AGAIN. HRRR DOES SHOW SOME ELEVATED DEVELOPMENT
LATER TONIGHT. SO CERTAINLY WORTHY OF KEEPING THE WATCH GOING FOR
NOW.
TUESDAY - CONFIDENCE...MEDIUM
AXIS OF LOW LEVEL JET TRANSLATES EAST A BIT AND IS AIMED MORE
TOWARDS SOUTHERN WI. 500 MILLIBAR SHOWS PERIODIC VORTICITY MAXIMA
WAVERING THROUGH THE WEAK WESTERLY FLOW. SOME UPPER DIVERGENCE NOTED
AS WELL...THOUGH OVERALL JET ACTION LOOKS PRETTY WEAK. CWASP NUMBERS
IN THE 60S...A FEW LOW 70S OFF THE NAM. BUT NOTHING EXTREME. WILL
KEEP HIGH END CHANCE/LIKELY POPS GOING WITH THE OVERALL PATTERN
STILL FAVORING CONVECTION DUE INSTABILITY AND RIPPLES IN THE FLOW.
.SHORT TERM...TUESDAY NIGHT THROUGH THURSDAY.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...FORECAST CONFIDENCE LOW TO
MEDIUM.
EVOLUTION FROM MOIST AND UNSTABLE NEAR-ZONAL WSW FLOW TO COOLER AND
DRIER NW FLOW BEGINS WITH APPROACH OF SHORT WAVE TROUGH AND
ASSOCIATED SURFACE LOW FROM THE DAKOTAS TUESDAY NIGHT...AND THEN
PASSAGE OF THE TROUGH AND LOW THROUGH THE WESTERN GREAT LAKES
WEDNESDAY AND WEDNESDAY NIGHT.
BETTER FORCING FROM THERMAL ADVECTION PER NAM/GFS 850-700MB Q-VECTOR
CONVERGENCE MAXIMA FOLLOWS A FAMILIAR PATTERN OF LATE ACROSS
NRN/CENTRAL IA INTO NRN IL...JUST BRUSHING SRN WI...WHICH FOLLOWS
ALONG THE NOSE OF THE THERMAL RIDGE AND STRONGEST 850 MB WINDS AS
THEY VEER FROM SOUTH TO SOUTHEAST WITH WAVE PASSAGE. HOWEVER
CONFIDENT FOR LIKELY POPS EVERYWHERE IN CWA WITH LARGE SALE FORCING
FOR ASCENT PROVIDED BY DIFFERENTIAL CVA THAT WORKS ON UNSTABLE AIR
MASS...WITH LOW LEVEL FORCING PROVIDED BY LOW TO MID-LAYER
FRONTOGENETIC FORCING.
FLOODING A CONCERN WITH ANY CONVECTION IN THIS MOISTURE RICH
ENVIRONMENT WITH 1.7 TO 1.9 INCH PW/S OR ABOUT 160 PCT OF NORMAL.
BEST PERFORMING MODEL QPF FORECASTS BRING AREAL AVERAGE
PRECIPITATION OF 1 TO 1.5 INCHES TO THE CWA...BUT ACTUAL AMOUNTS
WILL BE MUCH HIGHER WITH ANY MCS THAT MOVES ACROSS CWA.
KEPT LIKELY POPS IN THE NORTH WITH BETTER OMEGA AS SFC LOW MOVES
THROUGH WEDNESDAY...AND CHANCE POPS EVERYWHERE ELSE...TAPERING OFF
WEDNESDAY NIGHT FROM WEST TO EAST BEHIND THE LOW.
WITH EXPECTED CONVECTION AND AT LEAST A SIGNIFICANT AMOUNT OF CLOUD
DEBRIS WENT WITH BLENDED HIGHS THAT TEND TOWARD THE COOLER SIDE OF
GUIDANCE.
THURSDAY...FORECAST CONFIDENCE MEDIUM.
MODELS DIFFER WITH HOW FAR EAST TO TAKE INITIAL SHORT WAVE TROUGH BY
THURSDAY MORNING...BUT ALL SHOW VORTICITY MAXIMA DROPPING THROUGH
EASTERN WI AT SOME POINT DURING THE DAY THURSDAY. NAM SOUNDINGS LOOK
A BIT TOO GENEROUS WITH SURFACE DEW POINTS...BUT LOW TO MID 80 TEMPS
WITH MID-UPPER 60 DEW POINTS STILL YIELD TALL SKINNY SURFACE-BASED
CAPE OF AT LEAST 600-800 J/KG...SO WILL HAVE CHANCE THUNDER IN THE
EAST...BUT LEAVE WESTERN AREAS DRY.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY. FORECAST CONFIDENCE
MEDIUM.
MODELS CONTINUE TO DIG EASTERN TROUGH THROUGH THE END OF THE WORK
WEEK AND DROP A A REINFORCING SHORT WAVE THROUGH THE REGION THAT
AIDS IN CLOSING OFF A 500 MB LOW SOMEWHERE OVER THE CENTRAL/EASTERN
GREAT LAKES SATURDAY. INSTABILITY WITH THE 500 COLD POOL OVER THE
REGION AND VORT MAXES ROTATING THROUGH THE TROUGH WILL KEEP AT LEAST
SLIGHT CHANCE POPS IN THROUGH THE EXTENDED...WITH AT OR SLIGHTLY
BELOW NORMAL TEMPERATURES INTO NEXT WEEK.
&&
.AVIATION/00Z TAFS/...CONVECTION ACROSS IOWA TO HAVE GREATEST IMPACT
IN FAR SRN WI INTO EARLY EVENING. STRONGEST ACTIVITY LOOKING TO STAY
SOUTH OF THE BORDER. THEN SETUP LOOKS SIMILAR TO LAST NIGHT WHERE
REDEVELOPMENT BECOMES FOCUSED FURTHER SOUTH. MODEL SOLUTIONS ARE
QUITE DIVERGENT ON HOW THE LATE NIGHT CONVECTION PLAYS OUT. BUT IF
LAST NIGHT IS ANY INDICATION...SOME TSRA POSSIBLE LATER TONIGHT INTO
THE EARLY MORNING HOURS...THEN MORE REDEVELOPMENT DURG TUE AFTN/EVE.
OVERALL...VFR WITH POCKETS OF MVFR/ISOLATED IFR IN ANY OF THE
HEAVIER STORMS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR WIZ046-047-056-057-
062-063-067>069.
LM...NONE.
&&
$$
TONIGHT/TUESDAY AND AVIATION/MARINE...COLLAR
TUESDAY NIGHT THROUGH MONDAY...REM
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND TUESDAY
ISSUED AT 226 PM CDT MON JUN 24 2013
THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A
SHORTWAVE TROUGH MOVING ENE OVER FAR EASTERN SOUTH DAKOTA AND INTO
SOUTHWEST MINNESOTA. AREA OF CONVECTION AHEAD OF THIS TROUGH IS
DRAWING CLOSER TO THE SW WISCONSIN BORDER. CLOUD COVER OVER CENTRAL
AND EAST-CENTRAL WISCONSIN HAS LIMITED HEATING SOMEWHAT TODAY...BUT
ML CAPES ARE APPROACHED A 1K J/KG...THOUGH STILL HAVE SOME CIN TO
OVERCOME. NOT SURE IF THIS INHIBITION WILL GET OVERCOME...SINCE
CLOUDS WILL ONLY THICKEN FROM HERE ON OUT. MOSTLY CLEAR SKIES EXIST
BEHIND THIS SHORTWAVE OVER THE CENTRAL PLAINS...AND THE NEXT
SHORTWAVE IS MOVING OVER THE CENTRAL ROCKIES. MAIN FORECAST
CONCERNS INCLUDE PRECIP CHANCES TONIGHT...AND SEVERE WEATHER CHANCES
TOMORROW.
TONIGHT...THE SHORTWAVE TROUGH MOVING INTO FAR SOUTHWEST MINNESOTA
WILL CONTINUE TO TRACK ENE ACROSS SOUTHERN MINNESOTA AND THE
NORTHERN HALF OF WISCONSIN THIS EVENING. CURRENT TRAJECTORY OF
PRECIPITATION WILL PLACE THE BEST CHANCES SOUTH OF A TOMAHAWK TO
IRON MOUNTAIN LINE. WITH CLOUD COVER KEEPING TEMPERATURES IN THE
UPPER 70S TO LOWER 80S OVER CENTRAL AND EAST-CENTRAL WISCONSIN...THE
STORMS WILL HAVE SOME CIN TO OVERCOME DESPITE ML CAPES AROUND 1000
J/KG. THINKING SEVERE CHANCES IS RATHER REMOTE SINCE THE NORTHERN
END OF THE THUNDERSTORM COMPLEX IS MOSTLY STRATIFORM. PWATS WILL BE
INCREASING OVER 1.50 INCHES SO THINKING HEAVY RAINFALL WILL BE THE
MAIN THREAT WITH THESE STORMS...BUT EVEN THAT DOES LOOK THAT
POSSIBLE. SHOWERS AND STORMS WILL HAVE MOSTLY EXITED THE REGION BY
LATE IN THE EVENING...AND THEY SHOULD LAY OUT AN OUTFLOW BOUNDARY
OVER SOUTHERN WISCONSIN OR POINTS FURTHER SOUTH. RETURN FLOW WILL
REDEVELOP OVER THE NORTHERN PLAINS LATE SO THINKING ANY CONVECTION
LATE TONIGHT WILL FALL ALONG THIS OUTFLOW BOUNDARY. HAVE DROPPED
POPS SIGNIFICANTLY AFTER MIDNIGHT AND ACROSS NORTHERN WISCONSIN.
MUGGY LOWS IN THE MIDDLE 60S.
TUESDAY...MUCH OF THE DETAILS IN TOMORROWS WEATHER WILL REVOLVE
AROUND WHERE RESULTING OUTFLOW BOUNDARIES END UP AND HOW QUICKLY THE
ATMOSPHERE CAN RECOVER. IF THE LAST FEW DAYS ARE ANY
INDICATION...IT COULD TAKE UNTIL MID TO LATE AFTERNOON FOR
DESTABILIZATION TO OCCUR. BY THIS TIME...RETURN FLOW WILL BE
SPREADING NORTHEAST INTO THE REGION AS A SHORTWAVE CURRENTLY OVER
COLORADO LIFTS INTO THE NORTHERN MISSISSIPPI VALLEY. DO NOT TRUST
MODEL SOUNDINGS MUCH...BUT TEMPS IN THE LOW TO MID 80S AND DEWPOINTS
IN THE UPPER 60S SHOULD YIELD AT LEAST 1000 J/KG OF CAPE. 0-6KM
BULK SHEAR IS RATHER POOR AROUND 20 KTS...SO WILL BE TOUGH TO GET
ANY ORGANIZED CONVECTION. BUT CANNOT RULE OUT AN ISOLATED MENTION
IF THE INSTABILITY RECOVERS. HIGHS IN THE LOW TO MID 80S.
.LONG TERM...TUESDAY NIGHT THROUGH MONDAY
ISSUED AT 226 PM CDT MON JUN 24 2013
BRIEF PERIOD OF ZONAL FLOW WILL BE ACCOMPANIED BY PRIMARY
SHORTWAVE FORECAST TO TRAVERSE THE WESTERN GREAT LAKES DURING THE
MIDDLE OF THE WORK WEEK. THERAFTER...THE MEDIUM RANGE GUIDANCE
CONTINUES TO ADVERTIZE PRONOUNCED RIDGING OVER THE WESTERN CONUS
WITH DEEPENING DOWNSTREAM TROUGH ACROSS THE GREAT LAKES AND OHIO
VALLEY. LOTS OF UNCERTAINTY WITH RESPECT TO THE DETAILS OF
EMBEDDED DISTURBANCES WITHIN THE INCREASING NORTHWESTERLY FLOW
OVER THE STATE LATE IN THE WORK WEEK. DAILY AVERAGE TEMPERATURES
SHOULD REMAIN ABOVE NORMAL...THEN FALL OFF CLOSER TO NORMAL OR
PERHAPS A LITTLE BELOW NORMAL BY THE WEEKEND.
TUESDAY NIGHT AND WEDNESDAY...
PRIMARY FORECAST CHALLENGE EARLY IN THE EXTENDED WILL BE TRYING
TO NARROW DOWN THE TIMING AND LOCATION OF CONVECTIVE ACTIVITY
ASSOCIATED WITH THE PRIMARY SHORTWAVE DISTURBANCE TUESDAY NIGHT
AND WEDNESDAY. FORECAST CONFIDENCE FOR THIS PERIOD IS LOW.
NOT GOING TO BUCK TRENDS PAST FEW DAYS AND WILL BET AGAINST
QUASISTATIONARY FRONTAL BOUNDARY NEAR THE ILLINOIS-WISCONSIN
MAKING MUCH NORTHWARD PROGRESS INTO THE FORECAST AREA TUESDAY
NIGHT DESPITE RATHER ROBUST SOUTHWESTERLY LOW-LEVEL FLOW AHEAD OF
THE APPROACHING SHORTWAVE. LATEST MODEL TRENDS SEEM TO SUGGEST
THAT BULK OF DEEP CONVECTION WILL FIRE ALONG BOUNDARY TO OUR
SOUTHWEST AROUND 00Z WEDNESDAY THEN HEAD MORE EASTERLY MAINLY
ACROSS THE SOUTHERN THIRD OF THE STATE TUESDAY NIGHT...AS LLJ
VEERS WSW BY 12Z WEDNESDAY. WILL TWEAK POPS SOMEWHAT TUESDAY
PLACING HIGHEST PROBABALITIES ACROSS THE SOUTHERN THIRD OF THE
FORECAST AREA AND TAPERING TO CHANCE ACROSS THE FAR NORTHEAST. IF
THIS SCENARIO PLAYS OUT...FEEL BEST COMBINATION OF SHEAR AND
INSTABLITY SUPPORTAIVE OF SEVERE STORMS WILL ALSO BE FOCUSED
GENERALLY SOUTH OF HIGHWAY 29 TUESDAY NIGHT. PW VALUES FORECAST
TO REMAIN QUITE HIGH...NEARLY 2SD ABOVE NORMAL TUESDAY
NIGHT...THUS LOCALLY HEAVY RAINFALL IS ALSO THREAT. AS SHORTWAVE
TROUGH AND ASSOCIATED SURFACE LOW MOVE ACROSS THE FORECAQST AREA
WEDNESDAY EXPECT MORE WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY
OVER THE ENTIRE FORECAST AREA. AT THIS TIME APPEARS WILL BE
CONSIDERABLE CLOUDS AROUND DURING THE DAY ON WEDNESDAY THUS FEEL
SEVERE THREAT WILL BE MARGINAL. AGAIN SOME POTENTIAL FOR LOCALLY
HEAVY RAINFALL ESPECIALLY OVER THE FOX VALLEY. WILL TREND MAX
TEMPS A FEW DEGREES LOWER WEDNESDAY ASSUMING MORE WIDESPREAD
PRECIPITATION AND CLOUD COVER. /EB/
THURSDAY INTO THE WEEKEND...
LONG RANGE MODELS IN AGREEMENT ON DEVELOPMENT OF HUGE UPPER RIDGE
OVER 110 W LATITUDE AND TROF OVER GREAT LAKES. THIS SPELLS A
SHOWERY PERIOD WITH TEMPS AOB NORMAL ACROSS REGION FRIDAY INTO
MONDAY. BOTH ECMWF AND GFS SHOW SIGNS OF ADDITIONAL ENERGY
DIGGING INTO TROF NEXT WEEK...KEEPING THE COOLISH WEATHER AROUND.
/JKL/.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1228 PM CDT MON JUN 24 2013
A THUNDERSTORM COMPLEX OVER SOUTHERN MINNESOTA AND IOWA IS EXPECTED
TO MOVE NORTHEAST THIS AFTERNOON INTO WISCONSIN. CURRENT TRENDS
SUPPORT CENTRAL AND NORTHEAST WISCONSIN RECEIVING SHOWERS AND
THUNDERSTORMS FROM THIS COMPLEX LATE THIS AFTERNOON AND INTO THE
EVENING. CIGS/VSBYS WILL LIKELY FALL INTO THE MVFR RANGE WITHIN ANY
THUNDERSTORMS. FOLLOWING THE PASSAGE OF THESE STORMS...WILL LIKELY
SEE A BREAK BUT UNCERTAINTY WILL BE HIGH AS TO HOW LONG. ITS QUITE
POSSIBLE THAT THE BREAK COULD LAST UNTIL TOMORROW AFTERNOON BEFORE
THE NEXT AROUND OF SHOWERS AND STORMS ARRIVE.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......JKL
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
131 PM CDT MON JUN 24 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 129 PM CDT MON JUN 24 2013
THIS IS A TOUGH ONE. CONFIDENCE WAS HIGHER THIS MORNING THAT A
SIGNIFICANT FLOODING SET UP WAS IN PLACE TONIGHT. HOWEVER...THE
MASSIVE AMOUNT OF CONVECTION OVER IOWA AND INTO NRN MO IS CRASHING
CONFIDENCE LEVELS. IT APPEARS THE OVERNIGHT COULD BE ALMOST DRY.
THE IDEAL SIGNIFICANT FLOODING SCENARIO IS IOWA BEING PRETTY CLEAN
AT THIS POINT AND BUILDING INSTABILITY...VERY HIGH INSTABILITY.
THEN...THE LOW-LEVEL JET BECOMING ACTIVE AND CONVERGENT ACROSS
MOST OF SRN MN...WITH INDIVIDUAL STORMS TRACKING EAST. THIS HAD
BEEN THE SIGNAL IN THE MODEL GUIDANCE SINCE YESTERDAY...BUT THIS
IS NOT GOING TO VERIFY WITH THE CURRENT WIDESPREAD CONVECTION
FOULING IT UP. THE WARM FRONT AND ISENTROPIC SLOPE IS BEING PUSHED
FURTHER SOUTH /GUESS IT IS A COLD FRONT THEN/. THIS IS ACTUALLY
GOOD NEWS AS WE WERE PRETTY WORRIED ABOUT A LONG AXIS FROM KFSD-
KLSE OF PROLONGED LOW-LEVEL JET UP SLOPE AND CONVERGENCE OF AN
UNSTABLE AIR MASS...AND DEEP WARM CLOUD REPEATING THUNDERSTORMS.
IN FACT...THE MOST RECENT TWO RAP RUNS OF 16-17Z BOTH HAVE
MIGRATED TOWARD THIS DRIER SCENARIO AND EVEN HAVE WESTERLY 850 MB
FLOW OVERNIGHT.
SO...WE ARE BEGINNING TO BELIEVE A MORE LIKELY OUTCOME MAY BE
CONVECTION MOVING THROUGH THIS AFTERNOON AND EARLY EVENING...AND
A RECOVERY PERIOD NEEDED BEFORE MORE WEATHER OCCURS. INSTABILITY
SHIFTING NORTH INTO THE KFSD AREA LATE OVERNIGHT INITIATING
CONVECTION IN NORTHWEST IA TUESDAY...SHIFTING EAST. BUT...IT COULD
MEAN NO HIGHER END RAINFALL NUMBERS WE UPGRADED TO THIS
MORNING...AND LESSER IMPACT FOR SURE. WE ARE TAKING A CAUTIOUS
APPROACH ON THIS...BUT IT APPEARS LESS THREAT MAY BE PRESENTING
ITSELF.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 415 AM CDT MON JUN 24 2013
FOR TUE NIGHT THRU WED NIGHT MODELS SHOW THE REMNANTS OF THE
TROUGHING NOW OVER CA WILL LIFT INTO AND ACROSS THE UPPER MIDWEST.
TREND CONTINUES TO FAVOR STRONGER OF THE EARLIER RUNS. WITH THIS
BEING A LARGER SCALE FEATURE AND THE DECENT MODEL CONSISTENCY FCST
CONFIDENCE FOR THIS PERIOD IS AVERAGE.
AS THE STRONGER MID LEVEL TROUGH MOVES INTO THE UPPER MIDWEST TUE
NIGHT THE PLAINS SFC LOW MOVES INTO MN/WI. LOWER LEVEL THERMO
DYNAMIC FORCING/LIFT AND MOISTURE TRANSPORT REMAINS STRONG INTO THE
AREA AHEAD OF THESE FEATURES. WHERE THE FRONT AHEAD OF THE LOW FROM
TODAY/TUE ENDS UP WILL DETERMINE WHERE THE STRONGER LIFT WILL BE.
MODEL CONSENSUS HAS IT SOMEWHERE OVER THE FCST AREA TUE NIGHT...
THUS CARRIED HIGHEST SHRA/TSRA CHANCES IN THE 60-70 PERCENT RANGE
OVER THE NORTHEAST 2/3 OF THE FCST AREA. PW VALUES REMAIN IN THE 1.5
TO 1.75 INCH RANGE WITH ANY STORMS CAPABLE OF PRODUCING HEAVY RAINS.
AGAIN...WILL LIKELY NEED MORE FLASH FLOOD WATCHES FOR PORTIONS OF
THE AREA INTO TUE NIGHT WITH POTENTIAL FOR ANOTHER 0.5 TO 1.5
INCHES...LOCALLY MORE...OF RAIN.
ONCE THIS STRONGER MID LEVEL TROUGH PASSES TUE NIGHT/WED MORNING THE
FLOW PATTERN OVER NOAM BEGINS TO CHANGE WITH RIDGING BUILDING OVER
THE WESTERN CONUS AND INCREASING NORTHWEST FLOW ALOFT OVER THE
UPPER MIDWEST. DRIER AIR AND HIGH PRESSURE WILL SLOWLY SPREAD INTO
MN/IA/WI WED/WED NIGHT. SHRA/TSRA CHANCES WILL LINGER WED WITH THE
SFC LOW-MID LEVEL TROUGH OVER THE REGION. SHRA/TSRA CHANCES
DECREASE WED NIGHT AS HGTS RISE AND THE SFC-MID LEVEL LOW/TROUGH
MOVE EAST OF THE AREA.
DUE TO THE CONVECTION DETAIL UNCERTAINTIES...CONTINUED TO USE THE
MODEL/ENSEMBLE CONSENSUS FOR LOWS/HIGHS IN THE TUE NIGHT TO WED
NIGHT PERIOD.
ONCE AGAIN NOT A LOT OF TIME SPENT LOOKING AT THE DAY 4-7 PERIOD.
24.00Z MEDIUM RANGE MODELS MAINTAIN A GOOD CONSENSUS FOR THE
BUILDING WESTERN NOAM RIDGING AND EASTERN NOAM TROUGHING IN THE THU-
SUN PERIOD...WHICH PUTS THE REGION UNDER INCREASING NORTHWEST FLOW
ALOFT. THU-SUN SHAPING UP TO BE A DRIER PERIOD WITH TEMPERATURES
COOLING TO NEAR OR A BIT BELOW NORMAL. FCST CONFIDENCE FOR THIS
PERIOD LOOKS TO BE AVERAGE TO GOOD.
DRIER HIGH PRESSURE BUILDS IN FOR THU-SUN...BUT PLENTY OF RESIDUAL
LOW LEVEL MOISTURE AND MAXIMUM EVAPO-TRANSPIRATION FROM WELL WATERED
VEGETATION AND WET SOILS APPEAR TO REMAIN...ALONG WITH STEEP LOW/
MID LEVEL LAPSE RATES AND SHORTWAVES RIPPLING THRU THE NORTHWEST
FLOW ALOFT. THU-SUN TRENDING TO BE DRY DAYS BUT SOME SMALLER
MAINLY DIURNAL SHRA/TSRA CHANCES TO PERSIST...AIDED BY THE PASSING
SHORTWAVES FROM TIME TO TIME. MODEL/ENSEMBLE CONSENSUS FOR HIGHS/
LOWS IN THE DAY 4-7 PERIOD LOOK WELL TRENDED FOR NOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 129 PM CDT MON JUN 24 2013
PERIODS OF TSRA WILL OCCUR THROUGH ABOUT 00Z. THIS MAY NEED TO BE
EXTENDED IN THE TAF SITES...WILL MONITOR...AS 18Z TAFS HAVE 2
HOURS OF TEMPO TSRA.
MASSIVE CONVECTIVE COMPLEX ACROSS IA HAS REALLY IMPACTED TSRA
FORECAST FOR THE OVERNIGHT HOURS. WAS THINKING THAT A MASSIVE RAIN
EVENT WAS IN PLACE BUT WITH THE IA CONVECTION...MANY OF THE GOOD
SET UP PARAMETERS ARE NOT AS FAVORABLE ANY LONGER OVERNIGHT. LATER
FORECASTS MAY REMOVE THE TSRA TO LESSER HOURS OR IMPACT. CEILINGS
WILL ALSO BE VERY DIFFICULT WITH MESSY...UNORGANIZED PATTERN
THROUGH THE PERIOD.
CONFIDENCE IS LOW IN THE TAF BEYOND 4-5 HOURS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR WIZ032>034-041>044-
053>055-061.
MN...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR MNZ079-086>088-
094>096.
IA...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR IAZ008>011-018-019-
029-030.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM....RRS
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1228 PM CDT MON JUN 24 2013
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND TUESDAY
ISSUED AT 444 AM CDT MON JUN 24 2013
THE CONTINUING SAGA ON WHERE AND WHEN FOR CONVECTION CONTINUES THIS
MORNING. LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY HINT AT
WEAK BOUNDARY OVER NORTHEAST WI SEEN IN DEW POINTS. AREA OF
DISORGANIZED TSTMS MOVING NORTH THROUGH IA AND WESTERN IL.
STARTING TO SEE MORE MOVEMENT TO EAST OVER IL IN LATEST SCANS WHICH
WOULD GO WITH MODELS PROJECTION OF LLVL JET SHIFTING MORE TO THE
WEST AND WEAKENING BY 12Z.
HRRR SEEMS TO HAVE BEST HANDLE ON CURRENT TRENDS...SHOWING ONLY
SPOTTY CONVECTION OVER CWA TODAY MAINLY OVER THE SOUTH HALF.
ALL MODELS STILL SHOWING VARIETY OF SOLUTIONS IN QPF PATTERN
THROUGH THIS PERIOD. HAVE TRENDED TOWARD NAM TODAY GIVEN DRIER
AIR WORKING IN AS SEEN IN SIG DROP IN PWATS ON MSP SOUNDING LAST
EVENING. SFC BASED INSTABILITY STILL SIG 1-2K...THOUGH NOT SEEING
ANY REAL TRIGGER/LIFT TODAY. WENT WITH SLIGHTS FOR LATE DAY
CONVECTION SOUTH AND EAST ALONG LAKE BREEZE BOUNDARY.
FORCING AND MOISTURE WORKS BACK INTO THE AREA THIS EVENING WITH
STRENGTHENING LLVL FLOW POINTING INTO SOUTHWEST WI AFTER
06Z. ALSO SEEING SOME SUPPORT FROM RRQ OF JET MAX MOVING THROUGH
LAKE SUPERIOR REGION. WILL GO WITH INCREASING CHANCE POPS TONIGHT
HIGH CHANCE POPS TUE AS FGEN/ISENTROPIC LIFT MAXIMIZED OVER CWA
FROM 12Z TO 18Z TUES. CWA REMAINS IN SLIGHT RISK AREA ON TUE.
SHEAR BETTER SOUTH FOR SOME WIND CONCERNS. WBZERO HGTS RATHER
HIGH FOR LARGE HAIL. WITH PWATS RETURNING TO 1.5 TO 2 INCHES AGAIN
HEAVY RAIN MORE OF CONCERN.
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY
ISSUED AT 444 AM CDT MON JUN 24 2013
500MB RIDGE EXPECTED TO BUILD ACROSS THE WESTERN UNITED STATES
WHILE UPPER TROUGH DEEPENS AND POSSIBLY CLOSES OFF ACROSS THE
WESTERN GREAT LAKES BY THE END OF THE WORK WEEK INTO NEXT WEEKEND.
FORECAST ISSUES ALREADY AT THE START OF THE PERIOD TUESDAY NIGHT.
HAVE CONCERNS ON THE PLACEMENT OF CONVECTION TUESDAY EVENING ACROSS
NORTHERN WISCONSIN. BELIEF IS THAT THE AXIS OF HEAVIER PRECIPITATION
TOO FAR NORTH. THINK BAND WILL BE FURTHER SOUTH AS FIRST COMPLEX OF
STORMS LATE MONDAY NIGHT AND TUESDAY WILL PUSH AN OUTFLOW BOUNDARY
SOUTHWARD THAN WHAT THE MODELS SHOW...SIMILAR TOO WHAT HAPPENED A
FEW DAYS AGO. GFS QPF FIELD SEEMS REASONABLE BASED ON MY CURRENT
THINKING. THIS COULD AFFECT THE RAIN CHANCES ACROSS THE NORTH
TUESDAY EVENING. SOUTHERN SECTIONS OF THE FORECAST AREA WILL BE
CLOSE ENOUGH TO STILL WARRANT LIKELY CHANCES. 500MB TROUGH SWINGS
INTO THE AREA TOWARDS 12Z WEDNESDAY...WARRANTING LIKELY POPS EVEN
ACROSS THE NORTH. UPPER TROUGH WILL SWING ACROSS THE AREA ON
WEDNESDAY. RAISED POPS TO 50 TO 55 PERCENT...AND MAY BUMP THEM
UP A LITTLE MORE BEFORE FORECAST ISSUANCE. THE UPPER TROUGH
SHOULD SWING EAST INTO LOWER MICHIGAN WEDNESDAY NIGHT. THERE WILL
STILL BE SOME LINGERING EVENING SHOWERS AND A FEW STORMS. MID
LEVEL LAPSE RATES NOT IMPRESSIVE...THEREFORE ONLY EXPECTED ISOLATED
NATURE OF ANY THUNDERSTORMS WEDNESDAY EVENING.
NORTHWEST FLOW ALOFT WILL CONTINUE THURSDAY AND FRIDAY...ALTHOUGH
A DEEPER 500MB TROUGH WILL SWING ACROSS THE AREA FRIDAY AFTERNOON AND
FRIDAY NIGHT. WILL CONTINUE THE SMALL CHANCES FOR SHOWERS SATURDAY...
BUT NOT TOO OPTIMISTIC WE WOULD SEE THEM AT THIS TIME SINCE UPPER
TROUGH WILL WELL EAST OF THE AREA WITH BUILDING HEIGHTS. CANADIAN
HIGH PRESSURE WILL DOMINATE THE WEATHER PATTERN ON SUNDAY...ALTHOUGH
COULD NOT RULE OUT A FEW ISOLATED SHOWERS SUNDAY AFTERNOON.
FOR THE MOST PART...VERIFICATION DATA HAS SHOWN WE AND NUMERICAL
GUIDANCE HAS BEEN TOO WARM OF LATE. DID NUDGE TEMPERATURES DOWN A
DEGREE OR TWO MOST PERIODS. WILL NEED TO WATCH WEDNESDAY...IF IT
STAYS CLOUDY AND THERE IS A LOT OF RAIN AROUND DURING THE DAY...
TEMPERATURES COULD STAY IN THE 70S.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1228 PM CDT MON JUN 24 2013
A THUNDERSTORM COMPLEX OVER SOUTHERN MINNESOTA AND IOWA IS EXPECTED
TO MOVE NORTHEAST THIS AFTERNOON INTO WISCONSIN. CURRENT TRENDS
SUPPORT CENTRAL AND NORTHEAST WISCONSIN RECEIVING SHOWERS AND
THUNDERSTORMS FROM THIS COMPLEX LATE THIS AFTERNOON AND INTO THE
EVENING. CIGS/VSBYS WILL LIKELY FALL INTO THE MVFR RANGE WITHIN ANY
THUNDERSTORMS. FOLLOWING THE PASSAGE OF THESE STORMS...WILL LIKELY
SEE A BREAK BUT UNCERTAINTY WILL BE HIGH AS TO HOW LONG. ITS QUITE
POSSIBLE THAT THE BREAK COULD LAST UNTIL TOMORROW AFTERNOON BEFORE
THE NEXT AROUND OF SHOWERS AND STORMS ARRIVE.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....TE
LONG TERM......ECKBERG
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1110 AM CDT MON JUN 24 2013
.UPDATE...NO CHANGES TO FLASH FLOOD WATCH HEADLINE. MAIN ACTION IN IOWA.
AIRMASS RELATIVELY MORE STABLE HERE IN SRN WI DUE TO CLOUD DEBRIS
FROM LATE NIGHT/EARLY MRNG MCS. NEW HRRR PUTS ERN IA AND NRN IL
MORE IN THE HOT SPOT THIS AFTERNOON AND THIS MAKES SENSE GIVEN THE
OUTLAW OF WHERE BETTER AIRMASS RESIDES TO SUPPORT SUSTAINED
STRONGER CONVECTION. MODELS ARE ALL SHOWING MORE CONVECTION
RE-FIRING TONIGHT ACRS SRN WI WITH ANOTHER 850 JET CORE ARRIVING
FROM THE SOUTHWEST...BUT LIKE LAST NIGHT WILL HAVE TO SEE HOW ALL
THIS ONGOING CONVECTION AFFECTS EFFECTIVE BOUNDARY
POSITION/AIRMASS CHARACTERISTICS AS WE HEAD INTO THE NIGHT. ALL
IN ALL FLASH FLOOD WATCH STILL LOOKS OK.
PC
&&
.AVIATION/18Z TAFS/...VFR CEILINGS FOR MUCH OF THE PERIOD.
CONVECTIVE TRENDS SUGGEST MAIN ACTION IN IOWA WILL MORE THAN
LIKELY AFFECT ERN IA AND NRN IL INTO THE EARLY EVENING...POSSIBLY
GRAZING THE FAR SOUTH...PER HRRR. POTENTIAL FOR CONVECTION TONIGHT
WILL DEPEND ON HOW THE ONGOING STORMS IN IOWA DISTRIBUTES
BOUNDARIES AND HOW THESE INTERACT WITH RENEWED 850 JET FOR THE
EVENING AND OVERNIGHT.
PC
&&
.PREV DISCUSSION... /ISSUED 412 AM CDT MON JUN 24 2013/
SHORT TERM...
TODAY AND TONIGHT-FORECAST CONFIDENCE MEDIUM.
FIRST CONCERN IS ONGOING MCS IN IOWA ON NOSE OF LOW LEVEL JET.
MODELS POINT NOSE OF JET FARTHER NORTH AND EAST DURING THE EARLY
MORNING SO THIS WILL COMING INTO MAINLY SOUTHWEST PARTS OF THE AREA
THAT WERE POUNDED BY HEAVY RAIN A COUPLE OF DAYS AGO. SEEMS THAT
RIGHT ENTRANCE REGION OF 90 KNOT 250 MB WIND MAX IN MN MAY BE AIDING
THESE STORMS.
OTHERWISE PERSISTENT 850-700 MB WARM ADVECTION WITHIN BROAD 850 MB
LOW LEVEL JET AND MOIST AIRMASS SHOULD YIELD SCATTERED TO NUMEROUS
THUNDERSTORMS TODAY AND TONIGHT.
TIMING AND LOCATION DIFFICULT AS USUAL WITH CONVECTION AND
ASSOCIATED MESOSCALE OUTFLOW BOUNDARIES BUT PRECIPITABLE WATER
VALUES WILL BE IN 130-160% OF NORMAL RANGE SO POTENTIAL FOR HEAVY
RAIN TO CONTINUE. FRANKLY YOU COULD EXTEND THE FLASH FLOOD WATCH
UNTIL WEDNESDAY MORNING BUT AFTER DISCUSSING THE MATTER WITH
SURROUNDING WFOS SEEMS THAT WE SHOULD FOCUS ON THE NEXT 12-24
HOURS. AFTER MUCH DELIBERATION DECIDED TO MATCH UP WITH ARX AND
EXTEND THE WATCH UNTIL 10 AM ON TUESDAY.
THESE SITUATIONS ARE ALWAYS DIFFICULT BECAUSE TRYING TO FORECAST QPF
FOR THE WHOLE AREA WITHOUT KNOWING WHICH COUPLE OF COUNTIES WILL GET
HIT WITH 3-5 INCHES OF RAIN OR MORE IS ALMOST IMPOSSIBLE. SO WE
BROAD BRUSH 0.50 TO 1.00" QPF KNOWING THAT SOME AREAS WILL GET VERY
LITTLE RAIN AND OTHERS MUCH MORE.
MARGINAL HAIL AND WIND THREAT EXISTS BUT SHOULD BE RELATIVELY MINOR
IN COMPARISON TO TUESDAY EVENING.
TUESDAY THROUGH WEDNESDAY NIGHT...FORECAST CONFIDENCE MEDIUM.
UNSETTLED PERIOD WITH MODELS PUTTING OUT A LOT OF CONVECTIVE DRIVEN
PRECIP AS THE WET AND HUMID PATTERN CONTINUES. MODELS ARE IN A
GENERAL/BROAD AGREEMENT REGARDING THE NEAR-ZONAL PATTERN AND A FEW
SHORT WAVE TROUGHS RIPPLING THROUGH. THE MAIN CONCERN IS TUESDAY
INTO WEDNESDAY. A SHORT WAVE TROUGH WILL BEGIN TO MOVE ACROSS THE
CWA LATE TUESDAY...WHERE THE BEST CHANCES FOR PRECIP ARE. LIKELY
POPS ACROSS MUCH OF THE CWA FROM 0Z TO 12Z WEDNESDAY WHERE DECENT
SYNOPTIC ASCENT...WITH Q-VECTOR DIVG AND LOW-LEVEL WAA...WILL
COINCIDE WITH A LLJ THAT WILL INITIAL TAKE AIM AT SOUTH CENTRAL
WI. THE LLJ THEN BECOMES MORE WSW BY 12Z WED. SFC LOW PRESSURE
TROUGH AND BOUNDARY EXPECTED TO BE OVER CENTRAL WI AT THIS TIME
TUESDAY AFTERNOON. GIVEN THE SETUP...DO CONCUR WITH PREV FCST
DISCUSSION CONCEPTUALLY ON A MCS TRAVERSING THE CWA GIVEN THE
LLJS FOCUS.
FLASH FLOOD/HEAVY RAIN POTENTIAL THIS PERIOD...WITH HIGH
PRECIPITABLE WATER VALUES AROUND 1.7-1.9 AT ITS PEAK IN THE
EVENING TUES/EARLY WED. STRONG THUNDERSTORM THREAT AS WELL TUESDAY
AND WEDNESDAY GIVEN ENVIRONMENT WITH AMPLE INSTABILITY AND
MOISTURE. OF NOTE...DEEP LAYER SHEAR MORE ROBUST THAN WE HAVE SEEN
PREVIOUSLY THE LAST FEW DAYS...WITH VALUES AROUND 20-30 KTS.
THUS...A DECENT SIGNAL IN SIGSVR ALSO. THE POTENTIAL FOR A WIND
AND HAIL THREAT DOES EXIST. A SLIGHT RISK IS PRESENT FOR ALL OF
THE CWA IN SPCS DAY 2 CATEGORICAL OUTLOOK THIS MORNING. SPC
OUTLOOK ON DAY 3 HAS THE EASTERN TWO THIRDS OF THE CWA IN SLIGHT
RISK ALSO.
HIGHS WERE LOWERED A BIT TUES AND WED...AND LEANED MORE TOWARDS
THE COOLER CONSENSUS GUIDANCE GIVEN THE SKY COVER ANTICIPATED AND
MOIST COLUMNS.
LONG TERM...
THURSDAY THROUGH SUNDAY NIGHT...FORECAST CONFIDENCE MEDIUM.
COOLING TREND BEGINS FRIDAY/THIS WEEKEND. MODELS IN AGREEMENT WITH
THE FLOW BECOMING MORE AMPLIFIED WITH A LONG WAVE TROUGH DIGGING
INTO THE GREAT LAKES REGION. GFS CONTINUES TO DIG NOTABLY
STRONGER WITH LARGER HT FALLS COMPARED TO NAM AND ECMWF. NW FLOW
THEN TAKES OVER THIS WEEKEND WITH COOLER TEMPS ALOFT BROUGHT
TOWARDS WISCONSIN. SFC HIGH PRESSURE BEGINS TO BUILDS IN SUNDAY
AND PERSIST THROUGH THE BEGINNING OF MONDAY.
AVIATION/12Z TAFS/...
AS IS TYPICAL IN CONVECTIVE SITUATIONS...MUCH OF THE TIME WILL BE
VFR WITH BRIEF AND DIFFICULT TO TIME PERIODS OF MVFR OR LOWER.
PRETTY MUCH A COIN TOSS PROBABILITY NEXT 24 HOURS SO WILL BE
CONSERVATIVE.
SEEMS THAT MORNING MCS MOVING OUT OF IOWA AND NORTHERN ILLINOIS WILL
MAINLY JUST BRUSH THE TAF SITES BUT SEVERAL ROUNDS ARE POSSIBLE BUT
ESPECIALLY TONIGHT AS AFTERNOON ACTIVITY MOVES ON NOSE OF LOW LEVEL
JET FROM IOWA AND MINNESOTA INTO WISCONSIN.
PESKY MVFR FOG IS POSSIBLE THIS MORNING AND AGAIN TONIGHT WITH HIGH
DEW POINTS BUT PROBABILITY IS A TAD LOW TO PUT IN TAFS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR WIZ046-047-056-057-
062-063-067>069.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...CRAVEN
TUESDAY THROUGH SUNDAY...ET
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
702 AM CDT MON JUN 24 2013
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 415 AM CDT MON JUN 24 2013
06Z DATA ANALYSIS HAD LOW PRESSURE OVER LK WINNIPEG AND OVER THE
OK/TX PANHANDLE AREA...WITH A WEAK RIDGE OF HIGH PRESSURE IN BETWEEN
ACROSS SD TO IA. FRONTAL BOUNDARY/TROUGH FROM THE TX/OK LOW WAS
ACROSS KS TO NORTHERN MO. WARM/MOISTURE ADVECTION/THETA-E
CONVERGENCE OVER THIS BOUNDARY FOCUSED FROM EASTERN CO TO SOUTHERN
IA...WHERE CONVECTION WAS FIRING EARLY THIS MORNING. THE FCST AREA
AND REST OF WI/MN GETTING A NEEDED BREAK FROM THE SHRA/TSRA SO FAR
SUNDAY THRU THIS MORNING...BEING NORTH/EAST OF THE SFC-700MB RIDGE
AXIS.
INITIALIZATIONS OF 24.00Z MODELS BETTER THAN THE PAST COUPLE 00Z
CYCLES...THIS EXCEPT FOR THE GFS TOO HIGH ON SFC DEW POINTS OVER
MUCH OF THE MID/UPPER MS VALLEY. EVEN WITH TIGHTER/BETTER
INITIALIZATIONS...SOLUTIONS CONTINUE TO HAVE MESO-SCALE DIFFERENCES
WHICH IMPACT THE SENSIBLE WEATHER IN THE SHORT TERM. DPROG/DT OF
500MB HGTS AT 24.00Z SHOWED THE MODEL RUNS OF 22.00Z AND 23.00Z
VERIFIED WELL ACROSS NOAM/EASTERN PAC...FAVORING STRONGER OF EARLIER
RUNS WITH THE TROUGH/ENERGY NEAR LK WINNIPEG AND THE TROUGHING OVER
CA. MODEL CONSENSUS REMAINS GOOD WITH THE LARGER SCALE FEATURES
TODAY THRU TUE BUT PLENTY OF DETAIL DIFFERENCES REMAIN WITH THE
WEAKER SHORTWAVES THRU THE SOUTHWEST FLOW OVER THE CENTRAL CONUS.
GENERAL TREND IS A LITTLE FLATTER WITH THE CENTRAL CONUS RIDGING AND
STRONGER WITH UNIDENTIFIABLE SHORTWAVE FEATURES. CHECK OF OBS VS.
MODEL DATA AT 06Z SHOWED ALL TO BE REASONABLE WITH THE SFC MASS
FIELDS OVER THE CENTRAL CONUS. PER WV IMAGERY MODELS LOOKED GOOD
WITH THE LARGER SHORTWAVES OVER NOAM...WHILE STRUGGLING WITH WHAT
LOOKED TO BE A WEAK SHORTWAVE AIDING THE NEB/CO/KS CONVECTION. AS
HAS BEEN THE CASE THE PAST FEW DAYS...MODELS HAVING DIFFICULTIES
WITH CONVECTION OVER THE CENTRAL CONUS. CLOSEST WITH THE 00-06Z
PRECIP LOOKED TO BE THE GFS AND THE HRRR WRF MODEL. NO ONE CLEAR
FAVORITE. WITH ALL THE MODEL SCENARIOS ON HOW CONVECTION PLAYS OUT
THE NEXT 48-72HRS AND MOST MODELS CONTINUING TO STRUGGLE WITH THAT
EARLY THIS MORNING...SHORT-TERM CONFIDENCE REMAINS BELOW AVERAGE.
FORECAST TODAY/TONIGHT HINGES ON WHERE THE KS/NORTHERN MO BOUNDARY
ENDS UP. MODEL CONSENSUS LIFTS THIS BOUNDARY...AND ITS FOCUS FOR
FORCING/LIFT/CONVECTION INITIATION...SLOWLY NORTH TODAY/TONIGHT...
TO SOUTHWEST MN TO EASTERN IA/NORTHWEST IL BY 12Z TUE. MOISTURE
TRANSPORT/THETA-E CONVERGENCE ON NOSE OF THE 850MB JET ALREADY
FIRING THE CONVECTION OVER IA...WITH THIS TRANSLATING EAST/NORTHEAST
TOWARD AND INTO THE SOUTHEAST END OF THE FCST AREA. WILL EXTEND THE
FLASH FLOOD WATCH FOR THE SOUTHEAST END OF THE FCST AREA THRU THE
MORNING.
LOW LEVEL MOISTURE TRANSPORT/THETA-E CONVERGENCE CONTINUES TO
INCREASE OVER THE FRONT AND TOWARD THE AREA TODAY AS LOW PRESSURE
LIFTS INTO NEB. GENERAL MODEL CONSENSUS FOR CONVECTION TO SLOWLY
BUILD WEST/SOUTH OF THE FCST AREA THIS MORNING THE LIFT INTO THE AREA
THIS AFTERNOON. PER THE HRRR...PART OF THIS IS THE COMPLEX MOVING
ACROSS NEB EARLY THIS MORNING. LEANING TOWARD THE HRRR WHICH HAS
BEEN DOING A DECENT JOB WITH THE CO/NEB CONVECTION AND THAT ACROSS
IA...THE NEB CONVECTION GROWS ONCE IT REACHES STRONGER/RICHER
MOISTURE TRANSPORT OVER EASTERN NEB/WESTERN IA. SOME FORM OF
CONVECTIVE COMPLEX THEN HEADS TOWARD THE FCST AREA FOR THE AFTERNOON.
LOW LEVEL THERMODYNAMIC FORCING STRENGTHENS INTO THE AREA TONIGHT
ALONG WITH THE MOISTURE TRANSPORT AS THE FRONT SLOWLY LIFTS NORTH.
RAISED SHRA/TSRA CHANCES INTO THE 60-70 PERCENT RANGE FOR TONIGHT
INTO TUE MORNING. ANY TSRA WILL REMAIN EFFICIENT RAIN MAKERS WITH PW
VALUES IN THE 1.5 TO 1.75 INCH RANGE...ML CAPES OF 2K-3K J/KG AND
WARM CLOUD DEPTHS OF 3.5 TO 4KM. WITH MANY AREAS WATERLOGGED AND
HAVING ONGOING FLOODING ISSUES...WILL EXPAND THE FLASH FLOOD WATCH
TO COVER ALL BUT CLARK/TAYLOR COUNTIES FOR THIS AFTERNOON THRU MID
MORNING TUE.
FORCING SIGNALS GET A LITTLE MORE MUDDIED TUE. THIS NOT UNEXPECTED
DUE TO POTENTIAL DIFFERENT OUTCOMES WITH CONVECTION OVER THE UPPER
MIDWEST TONIGHT. APPEARS THE FRONT WILL REMAIN SOUTH OF THE FCST
AREA WITH THE 925-850MB FLOW CONTINUING TO PUSH/LIFT MOISTURE
NORTHWARD OVER IT. CONTINUED 40-60 PERCENT SHRA/TSRA CHANCES OVER
MUCH OF THE FCST AREA TUE. MAY NEED TO EXTEND THE FLASH FLOOD WATCH
THRU TUE INTO TUE NIGHT...BUT WILL DEAL WITH THAT ONCE WE GET PAST
TONIGHT.
ON TOP OF THE HEAVY RAIN CONCERNS...A FEW OF THE TSRA COULD BE
SEVERE THIS AFTERNOON/EVENING AND AGAIN TUE INTO TUE EVENING DUE
TO THE STRONG INSTABILITY...INCREASE OF THE 0-6KM SHEAR AND
POTENTIAL FOR TSRA TO ORGANIZE INTO COMPLEXES WITH STRONG COLD
POOLS. SEE SWODY1 AND SWODY2 FOR MORE DETAILS.
USED A BLEND OF THE NUMERICAL TEMP GUIDANCE FOR HIGHS/LOWS FOR
TODAY THRU TUE.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 415 AM CDT MON JUN 24 2013
FOR TUE NIGHT THRU WED NIGHT MODELS SHOW THE REMNANTS OF THE
TROUGHING NOW OVER CA WILL LIFT INTO AND ACROSS THE UPPER MIDWEST.
TREND CONTINUES TO FAVOR STRONGER OF THE EARLIER RUNS. WITH THIS
BEING A LARGER SCALE FEATURE AND THE DECENT MODEL CONSISTENCY FCST
CONFIDENCE FOR THIS PERIOD IS AVERAGE.
AS THE STRONGER MID LEVEL TROUGH MOVES INTO THE UPPER MIDWEST TUE
NIGHT THE PLAINS SFC LOW MOVES INTO MN/WI. LOWER LEVEL THERMO
DYNAMIC FORCING/LIFT AND MOISTURE TRANSPORT REMAINS STRONG INTO THE
AREA AHEAD OF THESE FEATURES. WHERE THE FRONT AHEAD OF THE LOW FROM
TODAY/TUE ENDS UP WILL DETERMINE WHERE THE STRONGER LIFT WILL BE.
MODEL CONSENSUS HAS IT SOMEWHERE OVER THE FCST AREA TUE NIGHT...
THUS CARRIED HIGHEST SHRA/TSRA CHANCES IN THE 60-70 PERCENT RANGE
OVER THE NORTHEAST 2/3 OF THE FCST AREA. PW VALUES REMAIN IN THE 1.5
TO 1.75 INCH RANGE WITH ANY STORMS CAPABLE OF PRODUCING HEAVY RAINS.
AGAIN...WILL LIKELY NEED MORE FLASH FLOOD WATCHES FOR PORTIONS OF
THE AREA INTO TUE NIGHT WITH POTENTIAL FOR ANOTHER 0.5 TO 1.5
INCHES...LOCALLY MORE...OF RAIN.
ONCE THIS STRONGER MID LEVEL TROUGH PASSES TUE NIGHT/WED MORNING THE
FLOW PATTERN OVER NOAM BEGINS TO CHANGE WITH RIDGING BUILDING OVER
THE WESTERN CONUS AND INCREASING NORTHWEST FLOW ALOFT OVER THE
UPPER MIDWEST. DRIER AIR AND HIGH PRESSURE WILL SLOWLY SPREAD INTO
MN/IA/WI WED/WED NIGHT. SHRA/TSRA CHANCES WILL LINGER WED WITH THE
SFC LOW-MID LEVEL TROUGH OVER THE REGION. SHRA/TSRA CHANCES
DECREASE WED NIGHT AS HGTS RISE AND THE SFC-MID LEVEL LOW/TROUGH
MOVE EAST OF THE AREA.
DUE TO THE CONVECTION DETAIL UNCERTAINTIES...CONTINUED TO USE THE
MODEL/ENSEMBLE CONSENSUS FOR LOWS/HIGHS IN THE TUE NIGHT TO WED
NIGHT PERIOD.
ONCE AGAIN NOT A LOT OF TIME SPENT LOOKING AT THE DAY 4-7 PERIOD.
24.00Z MEDIUM RANGE MODELS MAINTAIN A GOOD CONSENSUS FOR THE
BUILDING WESTERN NOAM RIDGING AND EASTERN NOAM TROUGHING IN THE THU-
SUN PERIOD...WHICH PUTS THE REGION UNDER INCREASING NORTHWEST FLOW
ALOFT. THU-SUN SHAPING UP TO BE A DRIER PERIOD WITH TEMPERATURES
COOLING TO NEAR OR A BIT BELOW NORMAL. FCST CONFIDENCE FOR THIS
PERIOD LOOKS TO BE AVERAGE TO GOOD.
DRIER HIGH PRESSURE BUILDS IN FOR THU-SUN...BUT PLENTY OF RESIDUAL
LOW LEVEL MOISTURE AND MAXIMUM EVAPO-TRANSPIRATION FROM WELL WATERED
VEGETATION AND WET SOILS APPEAR TO REMAIN...ALONG WITH STEEP LOW/
MID LEVEL LAPSE RATES AND SHORTWAVES RIPPLING THRU THE NORTHWEST
FLOW ALOFT. THU-SUN TRENDING TO BE DRY DAYS BUT SOME SMALLER
MAINLY DIURNAL SHRA/TSRA CHANCES TO PERSIST...AIDED BY THE PASSING
SHORTWAVES FROM TIME TO TIME. MODEL/ENSEMBLE CONSENSUS FOR HIGHS/
LOWS IN THE DAY 4-7 PERIOD LOOK WELL TRENDED FOR NOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 702 AM CDT MON JUN 24 2013
SHOWERS AND THUNDERSTORMS WILL MOVE INTO THE REGION LATE THIS
AFTERNOON AS A WARM FRONT LIFTS INTO NORTHERN IOWA/SOUTHERN
WISCONSIN. PLAN ON SHOWERS AND STORMS IMPACTING THE TAF SITES
THROUGH THE EVENING HOURS INTO EARLY TUESDAY MORNING. THE RAIN MAY
BECOME HEAVY AT TIMES. A FEW THUNDERSTORMS MAY PRODUCE GUSTY
WINDS...ESPECIALLY LATE THIS AFTERNOON INTO THE EVENING HOURS.
VISIBILITIES WILL BE REDUCED TO 3SM IN THE HEAVIER THUNDERSTORMS.
OTHERWISE...PLAN ON VFR/MVFR CONDITIONS BEFORE THE STORMS MOVE IN
WITH CLOUD BASES IN THE 3000 TO 4000 FT RANGE.
&&
.HYDROLOGY...
ISSUED AT 415 AM CDT MON JUN 24 2013
THE THREAT FOR HEAVY RAINS CONTINUES/RETURNS TODAY AS YET ANOTHER
LOW LIFTS INTO THE CENTRAL PLAINS AND MOISTURE TRANSPORT INCREASES
INTO THE AREA. A FRONT SLOWLY LIFTING NORTH FROM KS/NORTHERN MO WILL
BE THE FOCUS FOR LIFT AND GENERATING TSRA TODAY/TONIGHT/TUE. THIS
BOUNDARY EXPECTED TO REMAIN SOUTH OF THE AREA THRU TUE...WITH THE
ZONE OF STRONGER LIFT REMAINING CLOSE TO OR OVER THE FCST AREA.
THUNDERSTORMS WILL CONTINUE TO BE EFFICIENT RAIN PRODUCERS. RAINFALL
AMOUNTS THIS AFTERNOON AND TONIGHT COULD RANGE FROM 0.50 TO 1.50
INCHES...WITH LOCALLY HIGHER AMOUNTS POSSIBLE. SINCE MUCH OF THE
AREA HAS SEEN ANYWHERE FROM 2 TO 10 INCHES DURING THE LAST 3 TO 4
DAYS...IT WILL NOT TAKE MUCH RAIN TO PRODUCE MORE FLOODING PROBLEMS.
ADDITION FLASH FLOODING IS QUITE POSSIBLE ACROSS PARTS OF THE
FORECAST AREA TODAY THRU TUE NIGHT. HOWEVER THERE CONTINUES TO BE
MUCH UNCERTAINTY ON WHERE THIS RAIN MAY FALL. CONTINUED THE FLASH
FLOOD WATCH FOR THE SOUTHEAST END OF THE FCST AREA THIS MORNING
THEN ISSUED A BROADER FLASH FLOOD WATCH FOR ALL BUT CLARK/TAYLOR
COUNTIES THIS AFTERNOON THROUGH MID MORNING TUE. APPEARS ANOTHER
ROUND OF WIDESPREAD CONVECTION IS POSSIBLE TUE NIGHT/WED MORNING
AND ADDITIONAL FLASH FLOOD WATCHES ARE LIKELY FOR THOSE PERIODS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLASH FLOOD WATCH FROM NOON CDT TODAY THROUGH TUESDAY MORNING
FOR WIZ032>034-041>044-053.
FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR WIZ054-055-061.
MN...FLASH FLOOD WATCH FROM NOON CDT TODAY THROUGH TUESDAY MORNING
FOR MNZ079-086>088-094>096.
IA...FLASH FLOOD WATCH FROM NOON CDT TODAY THROUGH TUESDAY MORNING
FOR IAZ008>010-018-019.
FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR IAZ011-029-030.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION...WETENKAMP
HYDROLOGY....RRS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
649 AM CDT MON JUN 24 2013
UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND TUESDAY
ISSUED AT 444 AM CDT MON JUN 24 2013
THE CONTINUING SAGA ON WHERE AND WHEN FOR CONVECTION CONTINUES THIS
MORNING. LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY HINT AT
WEAK BOUNDARY OVER NORTHEAST WI SEEN IN DEW POINTS. AREA OF
DISORGANIZED TSTMS MOVING NORTH THROUGH IA AND WESTERN IL.
STARTING TO SEE MORE MOVEMENT TO EAST OVER IL IN LATEST SCANS WHICH
WOULD GO WITH MODELS PROJECTION OF LLVL JET SHIFTING MORE TO THE
WEST AND WEAKENING BY 12Z.
HRRR SEEMS TO HAVE BEST HANDLE ON CURRENT TRENDS...SHOWING ONLY
SPOTTY CONVECTION OVER CWA TODAY MAINLY OVER THE SOUTH HALF.
ALL MODELS STILL SHOWING VARIETY OF SOLUTIONS IN QPF PATTERN
THROUGH THIS PERIOD. HAVE TRENDED TOWARD NAM TODAY GIVEN DRIER
AIR WORKING IN AS SEEN IN SIG DROP IN PWATS ON MSP SOUNDING LAST
EVENING. SFC BASED INSTABILITY STILL SIG 1-2K...THOUGH NOT SEEING
ANY REAL TRIGGER/LIFT TODAY. WENT WITH SLIGHTS FOR LATE DAY
CONVECTION SOUTH AND EAST ALONG LAKE BREEZE BOUNDARY.
FORCING AND MOISTURE WORKS BACK INTO THE AREA THIS EVENING WITH
STRENGTHENING LLVL FLOW POINTING INTO SOUTHWEST WI AFTER
06Z. ALSO SEEING SOME SUPPORT FROM RRQ OF JET MAX MOVING THROUGH
LAKE SUPERIOR REGION. WILL GO WITH INCREASING CHANCE POPS TONIGHT
HIGH CHANCE POPS TUE AS FGEN/ISENTROPIC LIFT MAXIMIZED OVER CWA
FROM 12Z TO 18Z TUES. CWA REMAINS IN SLIGHT RISK AREA ON TUE.
SHEAR BETTER SOUTH FOR SOME WIND CONCERNS. WBZERO HGTS RATHER
HIGH FOR LARGE HAIL. WITH PWATS RETURNING TO 1.5 TO 2 INCHES AGAIN
HEAVY RAIN MORE OF CONCERN.
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY
ISSUED AT 444 AM CDT MON JUN 24 2013
500MB RIDGE EXPECTED TO BUILD ACROSS THE WESTERN UNITED STATES
WHILE UPPER TROUGH DEEPENS AND POSSIBLY CLOSES OFF ACROSS THE
WESTERN GREAT LAKES BY THE END OF THE WORK WEEK INTO NEXT WEEKEND.
FORECAST ISSUES ALREADY AT THE START OF THE PERIOD TUESDAY NIGHT.
HAVE CONCERNS ON THE PLACEMENT OF CONVECTION TUESDAY EVENING ACROSS
NORTHERN WISCONSIN. BELIEF IS THAT THE AXIS OF HEAVIER PRECIPITATION
TOO FAR NORTH. THINK BAND WILL BE FURTHER SOUTH AS FIRST COMPLEX OF
STORMS LATE MONDAY NIGHT AND TUESDAY WILL PUSH AN OUTFLOW BOUNDARY
SOUTHWARD THAN WHAT THE MODELS SHOW...SIMILAR TOO WHAT HAPPENED A
FEW DAYS AGO. GFS QPF FIELD SEEMS REASONABLE BASED ON MY CURRENT
THINKING. THIS COULD AFFECT THE RAIN CHANCES ACROSS THE NORTH
TUESDAY EVENING. SOUTHERN SECTIONS OF THE FORECAST AREA WILL BE
CLOSE ENOUGH TO STILL WARRANT LIKELY CHANCES. 500MB TROUGH SWINGS
INTO THE AREA TOWARDS 12Z WEDNESDAY...WARRANTING LIKELY POPS EVEN
ACROSS THE NORTH. UPPER TROUGH WILL SWING ACROSS THE AREA ON
WEDNESDAY. RAISED POPS TO 50 TO 55 PERCENT...AND MAY BUMP THEM
UP A LITTLE MORE BEFORE FORECAST ISSUANCE. THE UPPER TROUGH
SHOULD SWING EAST INTO LOWER MICHIGAN WEDNESDAY NIGHT. THERE WILL
STILL BE SOME LINGERING EVENING SHOWERS AND A FEW STORMS. MID
LEVEL LAPSE RATES NOT IMPRESSIVE...THEREFORE ONLY EXPECTED ISOLATED
NATURE OF ANY THUNDERSTORMS WEDNESDAY EVENING.
NORTHWEST FLOW ALOFT WILL CONTINUE THURSDAY AND FRIDAY...ALTHOUGH
A DEEPER 500MB TROUGH WILL SWING ACROSS THE AREA FRIDAY AFTERNOON AND
FRIDAY NIGHT. WILL CONTINUE THE SMALL CHANCES FOR SHOWERS SATURDAY...
BUT NOT TOO OPTIMISTIC WE WOULD SEE THEM AT THIS TIME SINCE UPPER
TROUGH WILL WELL EAST OF THE AREA WITH BUILDING HEIGHTS. CANADIAN
HIGH PRESSURE WILL DOMINATE THE WEATHER PATTERN ON SUNDAY...ALTHOUGH
COULD NOT RULE OUT A FEW ISOLATED SHOWERS SUNDAY AFTERNOON.
FOR THE MOST PART...VERIFICATION DATA HAS SHOWN WE AND NUMERICAL
GUIDANCE HAS BEEN TOO WARM OF LATE. DID NUDGE TEMPERATURES DOWN A
DEGREE OR TWO MOST PERIODS. WILL NEED TO WATCH WEDNESDAY...IF IT
STAYS CLOUDY AND THERE IS A LOT OF RAIN AROUND DURING THE DAY...
TEMPERATURES COULD STAY IN THE 70S.
&&
.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 641 AM CDT MON JUN 24 2013
WILL CONTINUE TO DEAL WITH WHEN AND WHERE SHOWERS AND
THUNDERSTORMS WILL BREAK OUT. WESTERLY FLOW AND DRIER AIR ALOFT
WILL EXPECTED TO LEAD TO MOSTLY DRY DAY...THOUGH STILL RATHER
HUMID AND UNSTABLE AT LOW LEVELS SO MAY SEE POSSIBLE CONVECTIVE
DEVELOPMENT ALONG ANY WEAK BOUNDARIES DURING THE AFTERNOON LIKE
LAKE BREEZE BOUNDARY. BEST ESTIMATE RIGHT NOW IS THAT SOME
CONVECTION WILL FIRE MONDAY NIGHT...AS A UPPER DISTURBANCE TRACKS
THROUGH THE AREA AND A SOUTHWESTERLY LOW-LEVEL JET REDEVELOPS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....TE
LONG TERM......ECKBERG
AVIATION.......TE
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND TUESDAY
ISSUED AT 444 AM CDT MON JUN 24 2013
THE CONTINUING SAGA ON WHERE AND WHEN FOR CONVECTION CONTINUES THIS
MORNING. LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY HINT AT
WEAK BOUNDARY OVER NORTHEAST WI SEEN IN DEW POINTS. AREA OF
DISORGANIZED TSTMS MOVING NORTH THROUGH IA AND WESTERN IL.
STARTING TO SEE MORE MOVEMENT TO EAST OVER IL IN LATEST SCANS WHICH
WOULD GO WITH MODELS PROJECTION OF LLVL JET SHIFTING MORE TO THE
WEST AND WEAKENING BY 12Z.
HRRR SEEMS TO HAVE BEST HANDLE ON CURRENT TRENDS...SHOWING ONLY
SPOTTY CONVECTION OVER CWA TODAY MAINLY OVER THE SOUTH HALF.
ALL MODELS STILL SHOWING VARIETY OF SOLUTIONS IN QPF PATTERN
THROUGH THIS PERIOD. HAVE TRENDED TOWARD NAM TODAY GIVEN DRIER
AIR WORKING IN AS SEEN IN SIG DROP IN PWATS ON MSP SOUNDING LAST
EVENING. SFC BASED INSTABILITY STILL SIG 1-2K...THOUGH NOT SEEING
ANY REAL TRIGGER/LIFT TODAY. WENT WITH SLIGHTS FOR LATE DAY
CONVECTION SOUTH AND EAST ALONG LAKE BREEZE BOUNDARY.
FORCING AND MOISTURE WORKS BACK INTO THE AREA THIS EVENING WITH
STRENGTHENING LLVL FLOW POINTING INTO SOUTHWEST WI AFTER
06Z. ALSO SEEING SOME SUPPORT FROM RRQ OF JET MAX MOVING THROUGH
LAKE SUPERIOR REGION. WILL GO WITH INCREASING CHANCE POPS TONIGHT
HIGH CHANCE POPS TUE AS FGEN/ISENTROPIC LIFT MAXIMIZED OVER CWA
FROM 12Z TO 18Z TUES. CWA REMAINS IN SLIGHT RISK AREA ON TUE.
SHEAR BETTER SOUTH FOR SOME WIND CONCERNS. WBZERO HGTS RATHER
HIGH FOR LARGE HAIL. WITH PWATS RETURNING TO 1.5 TO 2 INCHES AGAIN
HEAVY RAIN MORE OF CONCERN.
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY
ISSUED AT 444 AM CDT MON JUN 24 2013
500MB RIDGE EXPECTED TO BUILD ACROSS THE WESTERN UNITED STATES
WHILE UPPER TROUGH DEEPENS AND POSSIBLY CLOSES OFF ACROSS THE
WESTERN GREAT LAKES BY THE END OF THE WORK WEEK INTO NEXT WEEKEND.
FORECAST ISSUES ALREADY AT THE START OF THE PERIOD TUESDAY NIGHT.
HAVE CONCERNS ON THE PLACEMENT OF CONVECTION TUESDAY EVENING ACROSS
NORTHERN WISCONSIN. BELIEF IS THAT THE AXIS OF HEAVIER PRECIPITATION
TOO FAR NORTH. THINK BAND WILL BE FURTHER SOUTH AS FIRST COMPLEX OF
STORMS LATE MONDAY NIGHT AND TUESDAY WILL PUSH AN OUTFLOW BOUNDARY
SOUTHWARD THAN WHAT THE MODELS SHOW...SIMILAR TOO WHAT HAPPENED A
FEW DAYS AGO. GFS QPF FIELD SEEMS REASONABLE BASED ON MY CURRENT
THINKING. THIS COULD AFFECT THE RAIN CHANCES ACROSS THE NORTH
TUESDAY EVENING. SOUTHERN SECTIONS OF THE FORECAST AREA WILL BE
CLOSE ENOUGH TO STILL WARRANT LIKELY CHANCES. 500MB TROUGH SWINGS
INTO THE AREA TOWARDS 12Z WEDNESDAY...WARRANTING LIKELY POPS EVEN
ACROSS THE NORTH. UPPER TROUGH WILL SWING ACROSS THE AREA ON
WEDNESDAY. RAISED POPS TO 50 TO 55 PERCENT...AND MAY BUMP THEM
UP A LITTLE MORE BEFORE FORECAST ISSUANCE. THE UPPER TROUGH
SHOULD SWING EAST INTO LOWER MICHIGAN WEDNESDAY NIGHT. THERE WILL
STILL BE SOME LINGERING EVENING SHOWERS AND A FEW STORMS. MID
LEVEL LAPSE RATES NOT IMPRESSIVE...THEREFORE ONLY EXPECTED ISOLATED
NATURE OF ANY THUNDERSTORMS WEDNESDAY EVENING.
NORTHWEST FLOW ALOFT WILL CONTINUE THURSDAY AND FRIDAY...ALTHOUGH
A DEEPER 500MB TROUGH WILL SWING ACROSS THE AREA FRIDAY AFTERNOON AND
FRIDAY NIGHT. WILL CONTINUE THE SMALL CHANCES FOR SHOWERS SATURDAY...
BUT NOT TOO OPTIMISTIC WE WOULD SEE THEM AT THIS TIME SINCE UPPER
TROUGH WILL WELL EAST OF THE AREA WITH BUILDING HEIGHTS. CANADIAN
HIGH PRESSURE WILL DOMINATE THE WEATHER PATTERN ON SUNDAY...ALTHOUGH
COULD NOT RULE OUT A FEW ISOLATED SHOWERS SUNDAY AFTERNOON.
FOR THE MOST PART...VERIFICATION DATA HAS SHOWN WE AND NUMERICAL
GUIDANCE HAS BEEN TOO WARM OF LATE. DID NUDGE TEMPERATURES DOWN A
DEGREE OR TWO MOST PERIODS. WILL NEED TO WATCH WEDNESDAY...IF IT
STAYS CLOUDY AND THERE IS A LOT OF RAIN AROUND DURING THE DAY...
TEMPERATURES COULD STAY IN THE 70S.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1122 PM CDT SUN JUN 23 2013
GETTING A HANDLE ON PCPN TRENDS HAS BEEN A TOUGH TASK OVER THE
PAST FEW DAYS...SO OVERALL CONFIDENCE REMAINS LOW. REGARDLESS...
CURRENT INDICATIONS ARE THAT THE REST OF TONIGHT AND MUCH OF
MONDAY SHOULD BE DRY. SOME DRIER AIR WILL CONTINUE TO OVERSPREAD
NORTHERN WI TONIGHT...AND REMAIN IN PLACE ON MONDAY. WILL STILL
NEED TO MONITOR FOR POSSIBLE CONVECTIVE DEVELOPMENT ALONG ANY
WEAK BOUNDARIES DURING THE AFTERNOON...BUT CONFIDENCE IS TOO LOW
TO MENTION IN THE TAFS. BEST ESTIMATE RIGHT NOW IS THAT SOME
CONVECTION WILL FIRE MONDAY NIGHT...AS A WEAK UPPER DISTURBANCE
TRACKS THROUGH THE AREA AND A SOUTHWESTERLY LOW-LEVEL JET
REDEVELOPS.
THERE IS SOME POTENTIAL FOR FOG LATE TONIGHT...ALTHOUGH WILL ONLY
MENTION MVFR VSBYS...EXCEPT AT RHI WHERE SOME IFR CONDITIONS MAY
OCCUR.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....TE
LONG TERM......ECKBERG
AVIATION.......KIECKBUSCH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
415 AM CDT MON JUN 24 2013
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 415 AM CDT MON JUN 24 2013
06Z DATA ANALYSIS HAD LOW PRESSURE OVER LK WINNIPEG AND OVER THE
OK/TX PANHANDLE AREA...WITH A WEAK RIDGE OF HIGH PRESSURE IN BETWEEN
ACROSS SD TO IA. FRONTAL BOUNDARY/TROUGH FROM THE TX/OK LOW WAS
ACROSS KS TO NORTHERN MO. WARM/MOISTURE ADVECTION/THETA-E
CONVERGENCE OVER THIS BOUNDARY FOCUSED FROM EASTERN CO TO SOUTHERN
IA...WHERE CONVECTION WAS FIRING EARLY THIS MORNING. THE FCST AREA
AND REST OF WI/MN GETTING A NEEDED BREAK FROM THE SHRA/TSRA SO FAR
SUNDAY THRU THIS MORNING...BEING NORTH/EAST OF THE SFC-700MB RIDGE
AXIS.
INITIALIZATIONS OF 24.00Z MODELS BETTER THAN THE PAST COUPLE 00Z
CYCLES...THIS EXCEPT FOR THE GFS TOO HIGH ON SFC DEW POINTS OVER
MUCH OF THE MID/UPPER MS VALLEY. EVEN WITH TIGHTER/BETTER
INITIALIZATIONS...SOLUTIONS CONTINUE TO HAVE MESO-SCALE DIFFERENCES
WHICH IMPACT THE SENSIBLE WEATHER IN THE SHORT TERM. DPROG/DT OF
500MB HGTS AT 24.00Z SHOWED THE MODEL RUNS OF 22.00Z AND 23.00Z
VERIFIED WELL ACROSS NOAM/EASTERN PAC...FAVORING STRONGER OF EARLIER
RUNS WITH THE TROUGH/ENERGY NEAR LK WINNIPEG AND THE TROUGHING OVER
CA. MODEL CONSENSUS REMAINS GOOD WITH THE LARGER SCALE FEATURES
TODAY THRU TUE BUT PLENTY OF DETAIL DIFFERENCES REMAIN WITH THE
WEAKER SHORTWAVES THRU THE SOUTHWEST FLOW OVER THE CENTRAL CONUS.
GENERAL TREND IS A LITTLE FLATTER WITH THE CENTRAL CONUS RIDGING AND
STRONGER WITH UNIDENTIFIABLE SHORTWAVE FEATURES. CHECK OF OBS VS.
MODEL DATA AT 06Z SHOWED ALL TO BE REASONABLE WITH THE SFC MASS
FIELDS OVER THE CENTRAL CONUS. PER WV IMAGERY MODELS LOOKED GOOD
WITH THE LARGER SHORTWAVES OVER NOAM...WHILE STRUGGLING WITH WHAT
LOOKED TO BE A WEAK SHORTWAVE AIDING THE NEB/CO/KS CONVECTION. AS
HAS BEEN THE CASE THE PAST FEW DAYS...MODELS HAVING DIFFICULTIES
WITH CONVECTION OVER THE CENTRAL CONUS. CLOSEST WITH THE 00-06Z
PRECIP LOOKED TO BE THE GFS AND THE HRRR WRF MODEL. NO ONE CLEAR
FAVORITE. WITH ALL THE MODEL SCENARIOS ON HOW CONVECTION PLAYS OUT
THE NEXT 48-72HRS AND MOST MODELS CONTINUING TO STRUGGLE WITH THAT
EARLY THIS MORNING...SHORT-TERM CONFIDENCE REMAINS BELOW AVERAGE.
FORECAST TODAY/TONIGHT HINGES ON WHERE THE KS/NORTHERN MO BOUNDARY
ENDS UP. MODEL CONSENSUS LIFTS THIS BOUNDARY...AND ITS FOCUS FOR
FORCING/LIFT/CONVECTION INITIATION...SLOWLY NORTH TODAY/TONIGHT...
TO SOUTHWEST MN TO EASTERN IA/NORTHWEST IL BY 12Z TUE. MOISTURE
TRANSPORT/THETA-E CONVERGENCE ON NOSE OF THE 850MB JET ALREADY
FIRING THE CONVECTION OVER IA...WITH THIS TRANSLATING EAST/NORTHEAST
TOWARD AND INTO THE SOUTHEAST END OF THE FCST AREA. WILL EXTEND THE
FLASH FLOOD WATCH FOR THE SOUTHEAST END OF THE FCST AREA THRU THE
MORNING.
LOW LEVEL MOISTURE TRANSPORT/THETA-E CONVERGENCE CONTINUES TO
INCREASE OVER THE FRONT AND TOWARD THE AREA TODAY AS LOW PRESSURE
LIFTS INTO NEB. GENERAL MODEL CONSENSUS FOR CONVECTION TO SLOWLY
BUILD WEST/SOUTH OF THE FCST AREA THIS MORNING THE LIFT INTO THE AREA
THIS AFTERNOON. PER THE HRRR...PART OF THIS IS THE COMPLEX MOVING
ACROSS NEB EARLY THIS MORNING. LEANING TOWARD THE HRRR WHICH HAS
BEEN DOING A DECENT JOB WITH THE CO/NEB CONVECTION AND THAT ACROSS
IA...THE NEB CONVECTION GROWS ONCE IT REACHES STRONGER/RICHER
MOISTURE TRANSPORT OVER EASTERN NEB/WESTERN IA. SOME FORM OF
CONVECTIVE COMPLEX THEN HEADS TOWARD THE FCST AREA FOR THE AFTERNOON.
LOW LEVEL THERMODYNAMIC FORCING STRENGTHENS INTO THE AREA TONIGHT
ALONG WITH THE MOISTURE TRANSPORT AS THE FRONT SLOWLY LIFTS NORTH.
RAISED SHRA/TSRA CHANCES INTO THE 60-70 PERCENT RANGE FOR TONIGHT
INTO TUE MORNING. ANY TSRA WILL REMAIN EFFICIENT RAIN MAKERS WITH PW
VALUES IN THE 1.5 TO 1.75 INCH RANGE...ML CAPES OF 2K-3K J/KG AND
WARM CLOUD DEPTHS OF 3.5 TO 4KM. WITH MANY AREAS WATERLOGGED AND
HAVING ONGOING FLOODING ISSUES...WILL EXPAND THE FLASH FLOOD WATCH
TO COVER ALL BUT CLARK/TAYLOR COUNTIES FOR THIS AFTERNOON THRU MID
MORNING TUE.
FORCING SIGNALS GET A LITTLE MORE MUDDIED TUE. THIS NOT UNEXPECTED
DUE TO POTENTIAL DIFFERENT OUTCOMES WITH CONVECTION OVER THE UPPER
MIDWEST TONIGHT. APPEARS THE FRONT WILL REMAIN SOUTH OF THE FCST
AREA WITH THE 925-850MB FLOW CONTINUING TO PUSH/LIFT MOISTURE
NORTHWARD OVER IT. CONTINUED 40-60 PERCENT SHRA/TSRA CHANCES OVER
MUCH OF THE FCST AREA TUE. MAY NEED TO EXTEND THE FLASH FLOOD WATCH
THRU TUE INTO TUE NIGHT...BUT WILL DEAL WITH THAT ONCE WE GET PAST
TONIGHT.
ON TOP OF THE HEAVY RAIN CONCERNS...A FEW OF THE TSRA COULD BE
SEVERE THIS AFTERNOON/EVENING AND AGAIN TUE INTO TUE EVENING DUE
TO THE STRONG INSTABILITY...INCREASE OF THE 0-6KM SHEAR AND
POTENTIAL FOR TSRA TO ORGANIZE INTO COMPLEXES WITH STRONG COLD
POOLS. SEE SWODY1 AND SWODY2 FOR MORE DETAILS.
USED A BLEND OF THE NUMERICAL TEMP GUIDANCE FOR HIGHS/LOWS FOR
TODAY THRU TUE.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 415 AM CDT MON JUN 24 2013
FOR TUE NIGHT THRU WED NIGHT MODELS SHOW THE REMNANTS OF THE
TROUGHING NOW OVER CA WILL LIFT INTO AND ACROSS THE UPPER MIDWEST.
TREND CONTINUES TO FAVOR STRONGER OF THE EARLIER RUNS. WITH THIS
BEING A LARGER SCALE FEATURE AND THE DECENT MODEL CONSISTENCY FCST
CONFIDENCE FOR THIS PERIOD IS AVERAGE.
AS THE STRONGER MID LEVEL TROUGH MOVES INTO THE UPPER MIDWEST TUE
NIGHT THE PLAINS SFC LOW MOVES INTO MN/WI. LOWER LEVEL THERMO
DYNAMIC FORCING/LIFT AND MOISTURE TRANSPORT REMAINS STRONG INTO THE
AREA AHEAD OF THESE FEATURES. WHERE THE FRONT AHEAD OF THE LOW FROM
TODAY/TUE ENDS UP WILL DETERMINE WHERE THE STRONGER LIFT WILL BE.
MODEL CONSENSUS HAS IT SOMEWHERE OVER THE FCST AREA TUE NIGHT...
THUS CARRIED HIGHEST SHRA/TSRA CHANCES IN THE 60-70 PERCENT RANGE
OVER THE NORTHEAST 2/3 OF THE FCST AREA. PW VALUES REMAIN IN THE 1.5
TO 1.75 INCH RANGE WITH ANY STORMS CAPABLE OF PRODUCING HEAVY RAINS.
AGAIN...WILL LIKELY NEED MORE FLASH FLOOD WATCHES FOR PORTIONS OF
THE AREA INTO TUE NIGHT WITH POTENTIAL FOR ANOTHER 0.5 TO 1.5
INCHES...LOCALLY MORE...OF RAIN.
ONCE THIS STRONGER MID LEVEL TROUGH PASSES TUE NIGHT/WED MORNING THE
FLOW PATTERN OVER NOAM BEGINS TO CHANGE WITH RIDGING BUILDING OVER
THE WESTERN CONUS AND INCREASING NORTHWEST FLOW ALOFT OVER THE
UPPER MIDWEST. DRIER AIR AND HIGH PRESSURE WILL SLOWLY SPREAD INTO
MN/IA/WI WED/WED NIGHT. SHRA/TSRA CHANCES WILL LINGER WED WITH THE
SFC LOW-MID LEVEL TROUGH OVER THE REGION. SHRA/TSRA CHANCES
DECREASE WED NIGHT AS HGTS RISE AND THE SFC-MID LEVEL LOW/TROUGH
MOVE EAST OF THE AREA.
DUE TO THE CONVECTION DETAIL UNCERTAINTIES...CONTINUED TO USE THE
MODEL/ENSEMBLE CONSENSUS FOR LOWS/HIGHS IN THE TUE NIGHT TO WED
NIGHT PERIOD.
ONCE AGAIN NOT A LOT OF TIME SPENT LOOKING AT THE DAY 4-7 PERIOD.
24.00Z MEDIUM RANGE MODELS MAINTAIN A GOOD CONSENSUS FOR THE
BUILDING WESTERN NOAM RIDGING AND EASTERN NOAM TROUGHING IN THE THU-
SUN PERIOD...WHICH PUTS THE REGION UNDER INCREASING NORTHWEST FLOW
ALOFT. THU-SUN SHAPING UP TO BE A DRIER PERIOD WITH TEMPERATURES
COOLING TO NEAR OR A BIT BELOW NORMAL. FCST CONFIDENCE FOR THIS
PERIOD LOOKS TO BE AVERAGE TO GOOD.
DRIER HIGH PRESSURE BUILDS IN FOR THU-SUN...BUT PLENTY OF RESIDUAL
LOW LEVEL MOISTURE AND MAXIMUM EVAPO-TRANSPIRATION FROM WELL WATERED
VEGETATION AND WET SOILS APPEAR TO REMAIN...ALONG WITH STEEP LOW/
MID LEVEL LAPSE RATES AND SHORTWAVES RIPPLING THRU THE NORTHWEST
FLOW ALOFT. THU-SUN TRENDING TO BE DRY DAYS BUT SOME SMALLER
MAINLY DIURNAL SHRA/TSRA CHANCES TO PERSIST...AIDED BY THE PASSING
SHORTWAVES FROM TIME TO TIME. MODEL/ENSEMBLE CONSENSUS FOR HIGHS/
LOWS IN THE DAY 4-7 PERIOD LOOK WELL TRENDED FOR NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1141 PM CDT SUN JUN 23 2013
WATCHING A LINE OF CONVECTION ACROSS SOUTHERN IOWA THIS EVENING
WITH THE CONCERN OF WHETHER THIS WILL MOVE NORTHEAST INTO THE AREA.
THE 24.02Z HRRR AND ITS PREVIOUS RUNS HAVE BEEN DOING A DECENT JOB
HANDLING THIS FEATURE AND ATTEMPTS TO BRING IT NORTHEAST BUT
WEAKEN IT WITH TIME. RECENT RADAR TRENDS SUGGEST ONLY A VERY SLOW
NORTHEAST MOVEMENT WHILE THE CORFIDI VECTORS WOULD SUGGEST A MORE
EASTWARD MOVEMENT. FOR NOW...PLAN TO CONTINUE WITH A DRY FORECAST
AND ONLY SHOW SOME VFR CLOUDS FROM THIS SYSTEM GETTING INTO THE
AREA. VARIOUS SOLUTIONS ON HOW MONDAY PLAYS OUT. WITH THE MAIN
BOUNDARY NOW WELL SOUTH OF THE AREA...SEVERAL MODELS INDICATING
THE NEXT ROUND OF CONVECTION SHOULD DEVELOP AGAIN OVER SOUTHERN
IOWA AND REMAIN TO THE SOUTH OF THE AREA. MODELS ALSO SHOW
DIFFERENT IDEAS WITH THE ONGOING CONVECTION OVER COLORADO. THE
23.12Z GEM AND ECMWF BRING THIS NORTHEAST AND EAST INTO THE AREA
WITH THE MEAN FLOW WHILE THE HRRR TAKES IT MORE EAST ACROSS
NEBRASKA AND KANSAS RIDING THE CAPE GRADIENT WHILE FEEDING OFF
THE LOW LEVEL MOISTURE FIELD. WOULD TEND TO THINK THE HRRR IDEA
HAS A HIGHER PROBABILITY OF VERIFYING...BUT THERE IS A SHORT WAVE
TROUGH DRIVING THIS SYSTEM THAT SHOULD GET INTO THE AREA LATE
MONDAY AFTERNOON OR EVENING. WITH THE FORCING FROM THAT...CANNOT
TOTALLY RULE OUT SOME CONVECTION DEVELOPING BUT WITH LOW
CONFIDENCE HAVE ONLY INCLUDED A VCTS AT THIS TIME.
&&
.HYDROLOGY...
ISSUED AT 415 AM CDT MON JUN 24 2013
THE THREAT FOR HEAVY RAINS CONTINUES/RETURNS TODAY AS YET ANOTHER
LOW LIFTS INTO THE CENTRAL PLAINS AND MOISTURE TRANSPORT INCREASES
INTO THE AREA. A FRONT SLOWLY LIFTING NORTH FROM KS/NORTHERN MO WILL
BE THE FOCUS FOR LIFT AND GENERATING TSRA TODAY/TONIGHT/TUE. THIS
BOUNDARY EXPECTED TO REMAIN SOUTH OF THE AREA THRU TUE...WITH THE
ZONE OF STRONGER LIFT REMAINING CLOSE TO OR OVER THE FCST AREA.
THUNDERSTORMS WILL CONTINUE TO BE EFFICIENT RAIN PRODUCERS. RAINFALL
AMOUNTS THIS AFTERNOON AND TONIGHT COULD RANGE FROM 0.50 TO 1.50
INCHES...WITH LOCALLY HIGHER AMOUNTS POSSIBLE. SINCE MUCH OF THE
AREA HAS SEEN ANYWHERE FROM 2 TO 10 INCHES DURING THE LAST 3 TO 4
DAYS...IT WILL NOT TAKE MUCH RAIN TO PRODUCE MORE FLOODING PROBLEMS.
ADDITION FLASH FLOODING IS QUITE POSSIBLE ACROSS PARTS OF THE
FORECAST AREA TODAY THRU TUE NIGHT. HOWEVER THERE CONTINUES TO BE
MUCH UNCERTAINTY ON WHERE THIS RAIN MAY FALL. CONTINUED THE FLASH
FLOOD WATCH FOR THE SOUTHEAST END OF THE FCST AREA THIS MORNING
THEN ISSUED A BROADER FLASH FLOOD WATCH FOR ALL BUT CLARK/TAYLOR
COUNTIES THIS AFTERNOON THROUGH MID MORNING TUE. APPEARS ANOTHER
ROUND OF WIDESPREAD CONVECTION IS POSSIBLE TUE NIGHT/WED MORNING
AND ADDITIONAL FLASH FLOOD WATCHES ARE LIKELY FOR THOSE PERIODS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLASH FLOOD WATCH FROM NOON CDT TODAY THROUGH TUESDAY MORNING
FOR WIZ032>034-041>044-053.
FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR WIZ054-055-061.
MN...FLASH FLOOD WATCH FROM NOON CDT TODAY THROUGH TUESDAY MORNING
FOR MNZ079-086>088-094>096.
IA...FLASH FLOOD WATCH FROM NOON CDT TODAY THROUGH TUESDAY MORNING
FOR IAZ008>010-018-019.
FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR IAZ011-029-030.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION.....04
HYDROLOGY....RRS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1141 PM CDT SUN JUN 23 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 344 PM CDT SUN JUN 23 2013
AT 3 PM...A LINE OF SHOWERS AND THUNDERSTORMS WAS MOVING ACROSS
NORTHERN ILLINOIS. MEANWHILE THERE WAS ANOTHER CONVERGENT BOUNDARY
ALONG THE MISSISSIPPI RIVER. BOTH THE 23.12Z ARW AND NMM DEVELOP A
LINE OF THE SHOWERS AND THUNDERSTORMS ALONG THE LATTER BOUNDARY
BETWEEN 23.21Z AND 24.00Z. HOWEVER THEY ALSO HAVE AROUND 3000 J/KG
OF SURFACE BASED CAPE AND THE SPC SURFACE BASED CAPE IS CURRENTLY
ONLY AROUND 500 J/KG...SO THINKING THAT THE AREA WILL REMAIN DRY
FOR LATE THIS AFTERNOON LIKE THE LAST 3 HOURLY RUNS OF THE HRRR
HAVE BEEN SHOWING.
FOR THIS EVENING...THE 23.12Z MESO /RAP...NMM...AND ARW/ AND
DETERMINISTIC MODELS SUGGEST THAT THE COMBINATION OF MODERATE 850
MB MOISTURE TRANSPORT AND 2 TO 3K MOST UNSTABLE CAPES WILL RESULT
IN THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS ACROSS NORTHEAST
IOWA...AND CENTRAL AND SOUTHWEST WISCONSIN. THE HRRR WAS
SUGGESTING A SIMILAR SCENARIO EARLIER THIS MORNING AND HAS SINCE
BACKED AWAY FROM THIS SOLUTION. WITH THERE BEING SUCH AGREEMENT IN
THE MODELS OPTED TO KEEP A 20 TO 60 PERCENT CHANCE GOING FOR THIS
AREA TONIGHT. WITH LITTLE OR NO PRECIPITATION EXPECTED ELSEWHERE
ACROSS THE FORECAST AREA...WILL DROP THE FLASH FLOOD WATCH
ACROSS SOUTHEAST MINNESOTA AND PARTS OF WEST CENTRAL WISCONSIN.
FOR OVERNIGHT...BOTH THE ECMWF AND NOW THE HRRR SHOW THAT A SHORT
WAVE CURRENTLY OVER THE TEXAS PANHANDLE WILL MOVE NORTHEAST INTO
NORTHEAST IOWA AND SOUTHWEST WISCONSIN. THE HRRR SHOWS AN AREA OF
SHOWERS AND THUNDERSTORMS SURGING NORTHWARD TOWARD THE FORECAST
AREA AFTER 07Z. DUE TO THIS KEPT...THE PRECIPITATION CHANCES IN
THE 20 TO 60 PERCENT RANGE. WITH PRECIPITABLE WATER VALUES AROUND
1.8 INCHES AND WARM CLOUD LAYER DEPTHS UP 4.5 KM...THESE
THUNDERSTORMS WILL BE VERY EFFICIENT RAIN PRODUCERS...THUS...KEPT
THE FLASH FLOOD WATCH UP NORTHEAST IOWA AND SOUTHWEST AND CENTRAL
WISCONSIN. THE ONLY QUESTION IN THE FORECAST IS WHETHER WE HAVE
THE PRECIPITATION CHANCES DECREASING TOO FAST TOWARD SUNRISE.
ON MONDAY...THERE IS UNCERTAINTY ON HOW LONG THE SHORT WAVE WILL
LINGER ACROSS SOUTHWEST WISCONSIN AND NORTHEAST IOWA. WITH MANY OF
THE MESO MODELS DRY FOR THE MORNING...DECIDED TO TREND THE
PRECIPITATION CHANCES TOWARD THE DRY SIDE. DURING THE
AFTERNOON...THERE IS UNCERTAINTY ON HOW FAST THE 850 MB MOISTURE
TRANSPORT WILL DEVELOP ACROSS THE AREA. THE NAM HAS IT DEVELOPING
DURING THE LATE AFTERNOON AND MANY OF THE OTHER MODELS SUGGEST
THAT IT MIGHT OCCUR ON MONDAY NIGHT. WITH THERE BEING VERY LITTLE
CONSISTENCY IN THE MODELS OVER THE PAST SEVERAL DAYS...DECIDED TO
COMPROMISE WITH 30 TO 40 PERCENT PRECIPITATION PROBABILITIES. LIKE
OVER THE WEEKEND...THE 0-6 KM SHEAR REMAINS LESS THAN 40 KNOTS.
HOWEVER THE 0-3KM CONTINUES ABOVE 30 KNOTS...THUS COULD SEE THE
POTENTIAL FOR SOME BOWING SEGMENTS AS THE THUNDERSTORMS BECOME
COLD POOL DOMINANT.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 344 PM CDT SUN JUN 23 2013
ON MONDAY NIGHT...THE MODELS CONTINUE TO SHOW THAT A MESOSCALE
CONVECTIVE COMPLEX WILL DEVELOP JUST WEST OF THE FORECAST AREA AND
THEN MOVE THROUGH THE FORECAST AREA DURING THE NIGHT. WITH STRONG
850 MB MOISTURE TRANSPORT AND ISENTROPIC LIFT INTO THE REGION...
PRECIPITABLE WATER VALUES RUNNING AROUND 2 INCHES...AND WARM CLOUD
DEPTHS EXCEEDING 4 KM...EXPECT AN AREA OF HEAVY RAIN /POTENTIALLY
3 TO 5 INCHES/ TO FALL ACROSS PARTS OF THE FORECAST AREA. MANY OF
THE MODELS ARE SUGGESTING ALONG AND NORTH OF THE INTERSTATE 90
CORRIDOR. HOWEVER WITH THE MODELS BEING A BIT TOO FAR NORTH
LATELY...THERE IS A POSSIBILITY THAT THE HEAVIEST PRECIPITATION
MAY FALL ACROSS NORTHEAST IOWA AND SOUTHWEST WISCONSIN. WILL
LIKELY HAVE TO ISSUE ANOTHER FLASH FLOOD WATCH FOR THIS TIME
PERIOD EITHER LATE TONIGHT OR ON MONDAY.
FROM TUESDAY AFTERNOON INTO TUESDAY NIGHT...THE MODELS SHOW YET
ANOTHER MESOSCALE CONVECTIVE COMPLEX MOVING THROUGH THE REGION.
WITH THE MODELS CONTINUING TO SHOW STRONG 850 MB MOISTURE
TRANSPORT AND ISENTROPIC LIFT INTO THE REGION... PRECIPITABLE
WATER VALUES RUNNING AROUND 2 INCHES...AND WARM CLOUD DEPTHS
EXCEEDING 4 KM...EXPECT AN AREA OF HEAVY RAIN /POTENTIALLY ANOTHER 3
TO 5 INCHES/ TO FALL ACROSS PARTS OF THE FORECAST AREA. AT THIS TIME...
IT LOOKS LIKE THE HEAVIEST RAIN WOULD FALL ALONG AND SOUTH OF THE
INTERSTATE 90 CORRIDOR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1141 PM CDT SUN JUN 23 2013
WATCHING A LINE OF CONVECTION ACROSS SOUTHERN IOWA THIS EVENING
WITH THE CONCERN OF WHETHER THIS WILL MOVE NORTHEAST INTO THE AREA.
THE 24.02Z HRRR AND ITS PREVIOUS RUNS HAVE BEEN DOING A DECENT JOB
HANDLING THIS FEATURE AND ATTEMPTS TO BRING IT NORTHEAST BUT
WEAKEN IT WITH TIME. RECENT RADAR TRENDS SUGGEST ONLY A VERY SLOW
NORTHEAST MOVEMENT WHILE THE CORFIDI VECTORS WOULD SUGGEST A MORE
EASTWARD MOVEMENT. FOR NOW...PLAN TO CONTINUE WITH A DRY FORECAST
AND ONLY SHOW SOME VFR CLOUDS FROM THIS SYSTEM GETTING INTO THE
AREA. VARIOUS SOLUTIONS ON HOW MONDAY PLAYS OUT. WITH THE MAIN
BOUNDARY NOW WELL SOUTH OF THE AREA...SEVERAL MODELS INDICATING
THE NEXT ROUND OF CONVECTION SHOULD DEVELOP AGAIN OVER SOUTHERN
IOWA AND REMAIN TO THE SOUTH OF THE AREA. MODELS ALSO SHOW
DIFFERENT IDEAS WITH THE ONGOING CONVECTION OVER COLORADO. THE
23.12Z GEM AND ECMWF BRING THIS NORTHEAST AND EAST INTO THE AREA
WITH THE MEAN FLOW WHILE THE HRRR TAKES IT MORE EAST ACROSS
NEBRASKA AND KANSAS RIDING THE CAPE GRADIENT WHILE FEEDING OFF
THE LOW LEVEL MOISTURE FIELD. WOULD TEND TO THINK THE HRRR IDEA
HAS A HIGHER PROBABILITY OF VERIFYING...BUT THERE IS A SHORT WAVE
TROUGH DRIVING THIS SYSTEM THAT SHOULD GET INTO THE AREA LATE
MONDAY AFTERNOON OR EVENING. WITH THE FORCING FROM THAT...CANNOT
TOTALLY RULE OUT SOME CONVECTION DEVELOPING BUT WITH LOW
CONFIDENCE HAVE ONLY INCLUDED A VCTS AT THIS TIME.
&&
.HYDROLOGY...
ISSUED AT 344 PM CDT SUN JUN 23 2013
WITH SLIGHTLY DRIER AIR MOVING INTO SOUTHEAST MINNESOTA AND WEST-
CENTRAL WISCONSIN THIS AFTERNOON...THE THREAT FOR HEAVY RAIN HAS
GREATLY DIMINISHED ACROSS MUCH OF SOUTHEAST MINNESOTA AND PARTS OF
WEST CENTRAL WISCONSIN. AS A RESULT...DROPPED THE FLASH FLOOD
WATCH IN THESE AREAS. MEANWHILE IN SOUTHWEST AND CENTRAL WISCONSIN
AND NORTHEAST IOWA...THERE WILL BE THE POTENTIAL FOR THE
DEVELOPMENT OF THUNDERSTORMS ACROSS THESE AREAS FROM LATE EVENING
INTO THE OVERNIGHT. CONDITIONS CONTINUE TO BE FAVORABLE FOR THE
THUNDERSTORMS TO EFFICIENT RAIN PRODUCERS. RAINFALL AMOUNTS
TONIGHT COULD RANGE FROM 0.50 TO 1.50 INCHES. SINCE THESE AREAS
HAVE SEEN ANYWHERE FROM 6 TO 10 INCHES DURING THE LAST 3 DAYS...IT
WILL NOT TAKE MUCH WATER TO PRODUCE FLASH FLOODING.
ADDITION FLASH FLOODING LOOKS LIKELY ACROSS PARTS OF THE FORECAST
AREA ON MONDAY NIGHT AND FROM TUESDAY AFTERNOON INTO TUESDAY NIGHT.
EACH OF THESE EVENTS COULD PRODUCE 3 TO 5 INCHES OF RAIN ACROSS
THE AREA. HOWEVER THERE CONTINUES TO BE MUCH UNCERTAINTY ON WHERE
THIS RAIN MAY FALL. EXPECT ADDITIONAL FLASH FLOOD WATCHES TO BE
ISSUED FOR THESE TIME PERIODS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLASH FLOOD WATCH UNTIL 7 AM CDT MONDAY FOR WIZ041>044-053>055-
061.
MN...FLASH FLOOD WATCH UNTIL 7 AM CDT MONDAY FOR MNZ096.
IA...FLASH FLOOD WATCH UNTIL 7 AM CDT MONDAY FOR IAZ008>011-018-019-
029-030.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...04
HYDROLOGY...BOYNE
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1133 PM CDT SUN JUN 23 2013
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.UPDATE...
ISSUED AT 943 PM CDT SUN JUN 23 2013
HAVE REMOVED PCPN CHANCES FOR THE REST OF TONIGHT. DAYTIME INSTABILITY
HAS WANED AND CONVERGENCE ALONG THE BOUNDARY THAT BISECTS THE CWA FROM
NE TO SW (SEE DEW POINT GRADIENT) HAS WEAKENED. 850 MB FLOW IS EXPECTED
TO CONTINUE TO VEER WEST OVERNIGHT...WHICH WILL BRING DRIER AIR INTO
THE REGION. PRECIPITABLE WATER ON THE MPX RAOB DROPPED FROM 1.72 INCH
AT 12Z TO 0.77 INCH AT 00Z.
DISTURBANCE OVER NORTHEAST COLORADO IS EXPECTED TO LIFT NE TOWARD WI
BY MONDAY EVENING. THE LLJ IS ALSO EXPECTED TO BACK SW AND INCREASE
UPSTREAM OF THE REGION...SO PCPN CHANCES SHOULD INCREASE AGAIN
TOMORROW NIGHT.
&&
.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 252 PM CDT SUN JUN 23 2013
THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SURFACE
WARM FRONT HAS MOVED THROUGH MOST OF WISCONSIN EXCEPT FOR FAR
NORTHEAST WISCONSIN EARLY THIS AFTERNOON. SOME REMNANT STORMS FROM
AN EARLIER LINE OF CONVECTION ARE MOVING ACROSS SOUTHERN
WISCONSIN...BUT STARTING TO SEE SIGNS OF BEEFY CU DEVELOPING FARTHER
NORTH FROM WAUSHARA COUNTY TO THE WESTERN UPPER PENINSULA. THIS IS
IN A REGION OF BUILDING ML CAPES FROM 1000-1400 J/KG. STILL PLENTY
OF TIME FOR FURTHER DESTABILIZATION TO OCCUR...WITH LIFT VIA
SHORTWAVE OVER NORTHWEST WISCONSIN. AM STILL EXPECTING STORMS TO
FIRE THOUGH IT MAY STILL HAVE A COUPLE HOURS TO GO. ACTUAL FRONT
LIES ACROSS EASTERN MINNESOTA AND CLEARING SKIES ARE MOVING INTO
SOUTHWEST MINNESOTA. IMPACTS FROM CONVECTION ARE THE MAIN FORECAST
CONCERN IN THE SHORT TERM.
TONIGHT..SHORTWAVE OVER NORTHWEST WISCONSIN WILL LIFT NORTHEAST AND
CLEAR NORTHEAST WISCONSIN IN THE EVENING. FORCING ALONG THE TAIL OF
THIS VORT AND FURTHER DESTABILIZATION SHOULD ALLOW SCT STORMS TO
MOVE ACROSS NORTHEAST WISCONSIN IN THE EVENING. WINDS AT 700MB ARE
PRETTY STRONG AT 45 TO 50 KTS...SO ANY STORMS WILL HAVE POTENTIAL AT
CREATING DAMAGING WIND GUSTS AND SMALL HAIL. LOSS OF HEATING AND
EXITING OF THE TAIL OF THE VORT SHOULD LET THE CONVECTION DIMINISH
AND/OR EXIT BY MID TO LATE EVENING. ACTUAL SURFACE FRONT WILL DROP
INTO NORTH-CENTRAL WISCONSIN AFTER MIDNIGHT. CONVERGENCE ALONG THE
FRONT IS VERY WEAK AND THERE IS NO SUPPORT ALOFT...SO COULD SEE SOME
LOW CLOUDS ALONG THE FRONT...MUCH NOT MUCH ELSE. WILL END POPS FROM
NW TO SE AFTER MIDNIGHT. MUGGY LOWS IN THE MID TO UPPER 60S.
MONDAY...SURFACE FRONT WILL STALL ACROSS NORTHERN WISCONSIN IN THE
MORNING. PROGGED SOUNDINGS AND UPSTREAM SATELLITE IMAGERY SHOW
PLENTY OF DRY AIR THROUGH THE COLUMN AND PARTLY TO MOSTLY CLEAR
SKIES. NO CLEAR TRIGGERS UPSTREAM EITHER SO WILL GO WITH A DRY BUT
PARTLY CLOUDY START TO THE DAY. COME AFTERNOON...AN 86/69 PARCEL
OVER THE FOX VALLEY WILL RESULT IN 3000 J/KG OF ML CAPE AND VERY
LITTLE CIN. CONVECTIVE TEMPS ARE IN THE LOW 90S AND DO NOT SEE A
TRIGGER...BUT PERHAPS THE LAKE BREEZE CAN CREATE THE NECESSARY
CONVERGENCE FOR A STORM OR TWO TO POP. WILL KEEP A SLIGHT CHANCE OF
A STORM OVER CENTRAL AND NORTHEAST WISCONSIN WHERE INSTABILITY IS
MAXIMIZED. HIGHS MAINLY IN THE MID 80S.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 252 PM CDT SUN JUN 23 2013
MEDIUM RANGE MODELS ARE IN GREATER DISAGREEMENT THAN
THE LAST FEW DAYS...ESPECIALLY WITH A POSSIBLE CONVECTIVE COMPLEX
LATE MONDAY NIGHT OR TUESDAY AND AGAIN WEDNESDAY NIGHT WITH THE
POSSIBLE FORMATION OF A CLOSED LOW OVER WISCONSIN OR UPPER
MICHIGAN. AS FAR AS LATE MONDAY NIGHT AND TUESDAY GOES IT LOOKS
LIKE THE GFS IS EXHIBITING SOME SORT OF CONVECTIVE FEEDBACK
PRODUCING A CLOSED UPPER LOW THAT MOVES ACROSS MINNESOTA AND
WISCONSIN PRODUCING CONSIDERABLE CONVECTION. THIS IS LIKELY
OVERDONE AND PREFER THE FLATTER AND SLOWER UPPER SYSTEM THAT SHOULD
BRING SHOWERS AND THUNDERSTORMS TUESDAY AFTERNOON AND EVENING.
THE GFS ALSO FORECASTS A CLOSED UPPER LOW WEDNESDAY NIGHT AND
THURSDAY OVER THE WESTERN GREAT LAKES WHICH SEEMS OVERDONE
CONSIDERING THE CURRENT PATTERN. CANNOT TOTALLY DISCOUNT THE GFS
AS IT HAS SOME SUPPORT FROM THE NAM BUT THE ECMWF IS MUCH FASTER
AND WEAKER. WARM AND HUMID WEATHER EXPECTED THROUGH THURSDAY.
AFTER THURSDAY THE MODELS DO AGREE THAT AN UPPER RIDGE
WILL DEVELOP OVER THE WESTERN UNITED STATES WITH CYCLONIC
NORTHWEST FLOW OVER WISCONSIN. THIS SHOULD BRING COOLER AND DRIER
AIR TO THE REGION BY FRIDAY AND SATURDAY. WHILE IT SHOULD BE
GENERALLY DRY FRIDAY AND SATURDAY THERE COULD BE SCATTERED DIURNAL
SHOWERS WITH COLD TEMPERATURES ALOFT.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1122 PM CDT SUN JUN 23 2013
GETTING A HANDLE ON PCPN TRENDS HAS BEEN A TOUGH TASK OVER THE
PAST FEW DAYS...SO OVERALL CONFIDENCE REMAINS LOW. REGARDLESS...
CURRENT INDICATIONS ARE THAT THE REST OF TONIGHT AND MUCH OF
MONDAY SHOULD BE DRY. SOME DRIER AIR WILL CONTINUE TO OVERSPREAD
NORTHERN WI TONIGHT...AND REMAIN IN PLACE ON MONDAY. WILL STILL
NEED TO MONITOR FOR POSSIBLE CONVECTIVE DEVELOPMENT ALONG ANY
WEAK BOUNDARIES DURING THE AFTERNOON...BUT CONFIDENCE IS TOO LOW
TO MENTION IN THE TAFS. BEST ESTIMATE RIGHT NOW IS THAT SOME
CONVECTION WILL FIRE MONDAY NIGHT...AS A WEAK UPPER DISTURBANCE
TRACKS THROUGH THE AREA AND A SOUTHWESTERLY LOW-LEVEL JET
REDEVELOPS.
THERE IS SOME POTENTIAL FOR FOG LATE TONIGHT...ALTHOUGH WILL ONLY
MENTION MVFR VSBYS...EXCEPT AT RHI WHERE SOME IFR CONDITIONS MAY
OCCUR.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE.........KIECKBUSCH
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......KIECKBUSCH
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
301 AM EDT Wed Jun 26 2013
.NEAR TERM [Today]...
Upper level ridging will continue to dominate the SE US for at least
a couple of more days, giving us hot and humid conditions with high
temps in the middle 90s across the interior, until a shortwave trof
becomes reestablished by late in the week and the upcoming weekend.
With the drier deep layer air, cut back on PoPs just a bit from
Tuesday`s forecast, but still believe the Type 4 Sea Breeze pattern
(light to moderate SW Flow between 1000 and 700 mb) will be
respectable enough to produce PoPs in the 30 to 40 percent range,
highest across the NE half of the CWA. As for storm intensity,
generally poor mid and upper level lapse rates combined with
continued warming aloft should preclude any significant strong to
severe storms, but the fairly light steering flow at the lower
levels could result in some locally heavy rainfall in the stronger
storms.
&&
.SHORT TERM [Thursday through Friday]...
Upper level trofing will continue dipping further south over the Ern
CONUS through the period. This will continue to veer the flow from
SWrly flow to Wrly. The flow Thursday will be moderate (<10 kts),
which would mean a regime 4 sea breeze day. Generally these days have
lots of showers and thunderstorms in north Florida near the coast,
but drier air from the west will enter the region and should keep
coverage a little lower. In fact, because of a cold front to our
north on Thursday, our northern counties have a slightly better
chance for rain on Thursday afternoon than our Florida counties do.
Friday, the flow will be stronger (>10 kts), meaning a regime 5
sea breeze day. These days typically see an earlier start and are
active inland, not just along the coast. As the cold front dips
further south Friday, expanded morning type 5 PoPs north and have a
blend of model confidence and sea breeze for the afternoon, giving a
broad area of chances for showers and thunderstorms Friday. Highs
Thursday will be in the mid 90s and lows Thursday night will be in
the mid 70s.
&&
.LONG TERM [Friday Night through Tuesday]...
A highly amplified upper level pattern with a deep trough becoming
firmly established over the eastern CONUS through the period. A
series of impulses are forecast to round the base of the trough
enhancing convection over the Tri-state area. A fairly potent
shortwave is forecast by the GFS to arrive on Saturday. The Bermuda
ridge will build westward early next week with the axis of the
trough retrograding to the Mississippi Valley. This will place the
local region under deep and very moist southwest flow. From all
appearances this will be an active period for convection with at
least climo PoPs (40-50%) each afternoon. Temps will be near
seasonal levels.
&&
.AVIATION...
[Through 12Z Thursday] A somewhat tricky TAF package for the
overnight hours, as the usually very reliable NARRE and HRRR are
generally devoid of any significant restrictions. Some of the
numerical guidance did show some MVFR level cigs or vis, so did fcst
periods of MVFR conditions at ECP and DHN, which were the 2 sites
that had the most measurable rainfall yesterday. As for the daylight
hours, it appears to be fairly convectively quiet for a Type 4 sea
breeze day with the upper level ridge dominating, but did go with 30
and 40 percent PoPs as mentioned above. Left ECP free from
convection at this time, went with prob30 groups at TLH and DHN, and
finally convective tempos at ABY and VLD.
&&
.MARINE...
Winds and waves over coastal waters will begin to pick up a bit this
weekend as a front approaches from our north. Winds will shift to
westerly at around 10-15 kts with waves building to 2-3 feet Friday
into Saturday. By Sunday, winds will be around 15 kts and waves may
reach about 4 feet, but should begin decreasing again by Monday.
Exercise caution conditions are possible on Sunday.
&&
.FIRE WEATHER...
Relative humidity values will stay safely above Red Flag criteria
through the period.
&&
.HYDROLOGY...
With no river sites currently in flood stage or action stage, and
with QPF for the next 3 days from WPC of <1", no flooding on area
rivers is expected in the next few days. Later this weekend and
early into next week, there is some potential for higher rainfall
amounts as a frontal system dips southward into our area, but they
should still be too low to cause widespread flooding. WPC is showing
QPF of 1-1.5" for Saturday through Sunday and 1-1.75" Monday through
Tuesday.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 95 73 94 74 93 / 30 30 30 20 50
Panama City 91 77 91 78 89 / 30 20 30 20 40
Dothan 95 74 95 75 94 / 30 20 30 30 50
Albany 96 74 95 74 93 / 40 20 40 30 40
Valdosta 96 71 94 74 93 / 40 30 30 30 50
Cross City 94 73 93 73 91 / 30 30 30 20 40
Apalachicola 90 75 89 77 88 / 30 20 20 20 40
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
Near Term/Aviation/Fire Weather...Gould
Short Term/Marine/Hydrology...Moore
Long Term...Barry
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
313 AM CDT WED JUN 26 2013
.DISCUSSION...
308 AM CDT
THE LATEST IN A SERIES OF WEAK SHORTWAVES IN QUASI-ZONAL SOUTHERN
STREAM FLOW HAS BEEN SUPPORTING WIDESPREAD CONVECTION AS IT MOVES
TOWARD THE AREA EARLY THIS MORNING. GRADUALLY OVER THE NEXT TWO
DAYS THE LARGE SCALE PATTERN WILL BE AMPLIFYING INTO A BROAD
ANTICYCLONE ACROSS THE WESTERN CONUS AND A DEEPENING LONGWAVE TROUGH
OVER THE EASTERN STATES. THE WARM HUMID CONDITIONS OF RECENT DAYS
WILL BE REPLACED BY COOL HUMID CONDITIONS BY THE WEEKEND...WHICH
THEN WILL PERSIST INTO NEXT WEEK.
FIRST QUESTION CONCERNS PRECIPITATION TRENDS FOR TODAY. AT 08Z THE
EXISTING AREAS OF CONVECTION ACROSS NORTHEAST IOWA INTO NORTHERN
ILLINOIS WERE LOCATED ALONG FAVORABLE GRADIENTS OF MOISTURE
TRANSPORT ON THE LEADING EDGE OF THE LOW LEVEL JET...AND UNDER A
WEAK SHORTWAVE DEPICTED IN THE RAP MODEL AND VWP OBS AT 850 AND 700
MB. THIS ACTIVITY SHOULD BE MOVING ACROSS NORTHEASTERN ILLINOIS
DURING THE PREDAWN HOURS BUT THEN BEGINNING TO WEAKEN AS THE
LLJ VEERS AND ADJUSTS ITS FOCUS MORE TOWARD CENTRAL AND SOUTHERN
ILLINOIS.
IF THIS ACTIVITY DOES DISSIPATE AS EXPECTED TOWARD MORNING...THE
PROSPECTS OF REDEVELOPMENT TODAY ARE SOMEWHAT UNCERTAIN DESPITE
MODEL QPF SOLUTIONS TO THE CONTRARY. LINGERING MORNING SHOWERS AND
THEN SCATTERED TSRA LATER ARE DEFINITELY NOT OUT OF THE QUESTION
LOCALLY BUT THE MORE FAVORABLE AREAS OF MOISTURE ADVECTION AND STEEP
MID LEVEL LAPSE RATES ARE FARTHER SOUTH TOWARD CENTRAL ILLINOIS AND
FARTHER NORTH ALONG THE WI/MN STATE LINE.
DESPITE THE APPROACH OF A SURFACE/850 FRONTAL ZONE...THE UPPER LEVEL
WAVES APPEAR TO BE SOMEWHAT OUT OF SYNC AND MORE
PROGRESSIVE...LEAVING THE LOWER LEVEL FEATURES UNDER AREAS OF RISING
HEIGHTS ALOFT. IN THE 0530Z SPC DAY 1 OUTLOOK THE SLIGHT RISK
EXTENDS NORTHWEST TOWARD MSP AND THEN WELL SOUTH AND EAST THROUGH
THE TENNESSEE AND OHIO VALLEYS. WOULD NOT BE SURPRISED TO SEE THIS
SPLIT IN LATER UPDATES...WITH THE THUMB TO OUR NORTHWEST SEPARATED
FROM THE AREA TO OUR SOUTH. BUT THAT WOULD BE CUTTING IT PRETTY
FINE GIVEN THE OVERALL UNCERTAINTY WITH THIS SITUATION.
LONG STORY SHORT...FOR TODAY THE PLAN WILL BE TO LOWER POPS INTO THE
CHANCE CATEGORY BY AFTERNOON FOR MOST OF THE AREA BUT KEEP IN MIND
THE PWATS APPROACHING TWO INCHES AND THEREFORE MAINTAIN THE FLASH
FLOOD WATCH AND THE MENTION OF TSRA.
AFTER TODAY THE SITUATION BECOMES ONLY SLIGHTLY MORE CLEAR BUT OF
SEEMINGLY LESSER IMPACT.
AMPLIFICATION OF THE LARGE SCALE FLOW WILL BEGIN TO INFLUENCE THE
LOCAL AREA BY TONIGHT INTO THURSDAY AFTER THE SURFACE TROUGH PUSHES
THROUGH THE AREA AND WINDS AT ALL LEVELS TURN TO THE NORTHWEST. LOW
LEVEL WARMTH AND HUMIDITY DO NOT REALLY DEPART UNTIL FRIDAY WHEN THE
EXPANDING EASTERN TROUGH PUSHES THE UPPER JET SOUTH OF THE AREA AND
USHERS IN SLIGHTLY DRIER BUT MILDER AIR.
WITH ONLY MARGINAL LAPSE RATES AND HEIGHTS ALOFT CONTINUING TO
INCREASE...NEITHER THURSDAY NOR FRIDAY LOOK PARTICULARLY FAVORABLE
FOR WIDESPREAD PRECIPITATION. AS MENTIONED IN AN EARLIER
DISCUSSION...IT WOULD NOT TAKE MUCH OF A SHORTWAVE IN THE UPPER FLOW
TO SUPPORT AN AFTERNOON SHOWER...SO WILL CONTINUE TO CARRY SLIGHT
CHANCE POPS ON BOTH DAYS.
BY THE WEEKEND THE CONVECTIVE INSTABILITY APPEARS TO HAVE
DECREASED...BUT THE PRESENCE OF BOTH A SURFACE AND UPPER LEVEL
TROUGH DROPPING SOUTH ACROSS THE AREA WILL STILL SUPPORT LARGE SCALE
LIFT...PRIMARILY TO THE SOUTH ON SUNDAY. PRECIP CHANCES FINALLY
DECREASE BY EARLY NEXT WEEK AS THE SURFACE AND UPPER SUPPORT
DIMINISH...BUT UNSEASONABLY COOL AIR REMAINS IN PLACE WITH CONTINUED
NORTH TO NORTHEASTERLY WINDS.
LENNING
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* TSRA LATE TONIGHT/EARLY WEDNESDAY MORNING.
* HEAVY RAIN AND MVFR VSBY LIKELY WITH THE TSRA.
* ADDITIONAL ROUND OF TSRA PSBL WEDNESDAY AFTERNOON.
* LAKE BREEZE PSBL WEDNESDAY AFTERNOON WITH WINDS BCMG E.
JEE
//DISCUSSION...UPDATED 06Z...
HIGH PRESSURE OVER THE SE US REMAINS IN PLACE WHILE A LOW OVER THE
NORTHEASTERN PLAINS SLIDES THROUGH THE WESTERN GREAT LAKES LATER
TODAY. CONVECTION IS CURRENTLY ON THE RADAR IN NORTHEAST IA AND
EAST CENTRAL IL/SOUTHERN IN. THE CONVECTION TO THE SOUTH SHOULD
REMAIN SOUTH OF THE TERMINALS. THE STORMS OVER IA ON THE OTHER
HAND SHOULD CONTINUE EASTWARD BEFORE BEGINNING TO MOVE TOWARD THE
SOUTHEAST. SCATTERED CONVECTION HAS ALSO BLOSSOMED AT THE NOSE OF
THE LOW LEVEL JET IN NORTHWEST IL AND SHOULD CONTINUE TO SEE MORE
SCATTERED CONVECTION. LASTLY...HAVE SEEN A FEW CELLS PULSE UP AND
THEN PULSE DOWN ARND DPA SO MOVED THE TEMPO FOR THUNDER UP BY AN
HOUR AT DPA.
AS FAR AS THE TAFS ARE CONCERNED...FEELING MUCH MORE CONFIDENT IN
TS IMPACTING THE TERMINALS BEFORE SUNRISE. KEPT A 2 HOUR WINDOW IN
THE TAFS SINCE STILL NOT HIGHLY CONFIDENT IN WHEN THE TS WILL MAKE
IT TO THE TERMINALS. ALSO KEPT A PERIOD OF RAIN BEHIND THE
THUNDERSTORMS AS THE IA CONVECTION SHOULD CONSOLIDATE AND HAVE A
REGION OF RAIN SHOWERS BEHIND IT. ODDS ARE THE RAIN WILL END
SOONER THAN INDICATED IN THE TAFS.
SOUTH WINDS ARND 10 KT ARE EXPECTED TOMORROW...WITH A LAKE BREEZE
DEVELOPING IN THE AFTN. THINKING THE WIND SHIFT WILL BE SIMILAR TO
YESTERDAY WITH A BRIEF PERIOD OF DUE EAST WINDS AND A MUCH LONGER
PERIOD OF SE WINDS BEHIND THE LAKE BREEZE. THE LAKE BREEZE SHOULD
MAKE IT THROUGH ALL OF THE EASTERN TERMINALS.
THE LOW/TROUGH MOVES THROUGH TOMORROW WITH YET ANOTHER ROUND OF
TSRA EXPECTED. THINKING TS IS PSBL AT RFD ARND 19Z AND THEN
REACHING ORD BY 21Z. THE COMBINED FORCING OF THE TROUGH AND LAKE
BREEZE COULD LEAD TO SOME VERY HEAVY RAINFALL AND MVFR VSBY. STILL
NOT VERY CONFIDENT IN TIMING AND COVERAGE OF TS THIS AFTERNOON SO
LEFT VCTS IN THE TAFS. WINDS WILL TURN NW TO W BEHIND THE TROUGH
AND SKIES WILL BEGIN TO CLEAR OUT LATE IN THE EVENING.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM-HIGH CONFIDENCE IN TSRA TONIGHT...MEDIUM CONFIDENCE WITH
TIMING.
* MEDIUM-LOW CONFIDENCE IN HOW MUCH AND HOW LONG RAIN WILL PERSIST
BEHIND THE THUNDERSTORMS.
* MEDIUM CONFIDENCE IN COVERAGE AND TIMING OF TSRA WEDNESDAY
AFTERNOON.
* MEDIUM CONFIDENCE IN TIMING OF LAKE BREEZE AND WINDS MAY BE MORE
SE THAN FORECAST BEHIND THE LAKE BREEZE.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY AND FRIDAY...GENERALLY VFR OUTSIDE OF COUPLE OF BRIEF PERIODS
OF THUNDERSTORMS.
SATURDAY THROUGH MONDAY...GENERALLY VFR. A COUPLE OF BRIEF PERIODS
OF SHOWERS.
ED F
&&
.MARINE...
150 AM CDT
ELONGATED SFC LOW PRESSURE TROUGH OVER THE MID-UPPER MISSOURI
VALLEY WILL MOVE SLOWLY EAST TODAY...WITH VARYING MODEL FORECASTS
DEVELOPING A WEAK SURFACE LOW PRESSURE WAVE IN THE VICINITY OF
NORTHERN IL/IND OR SOUTHERN LAKE MICHIGAN BY THIS EVENING. SOUTH
TO SOUTHEAST WINDS SHOULD DIMINISH IN SPEED AS THE GRADIENT
WEAKENS WITH THE APPROACH OF THE TROUGH THIS AFTERNOON...WITH LAKE
BREEZE ESPECIALLY ALONG THE WESTERN SHORE. THUNDERSTORMS WILL BE
POSSIBLE ESPECIALLY OVER THE SOUTHERN HALF OF THE LAKE...WHICH MAY
RESULT IN SOME LOCALLY STRONGER WINDS. WINDS MAY BECOME SOMEWHAT
VARIABLE AT 10 KT OR LESS TONIGHT AS THE SURFACE TROUGH/COLD FRONT
MOVE SLOWLY ACROSS THE LAKE...EVENTUALLY TAKING ON A WEST-
NORTHWEST DIRECTION THURSDAY AS THE TROUGH MOVES OFF TO THE EAST.
SPEEDS SHOULD REMAIN GENERALLY LIGHT HOWEVER...WITH A RELATIVELY
WEAK GRADIENT INTO FRIDAY.
WEAK HIGH PRESSURE RIDGING WILL DEVELOP SOUTHEAST ACROSS THE
NORTHERN AND CENTRAL HIGH PLAINS INTO THE WEEKEND...WHILE THE LOW
PRESSURE WAVE EVENTUALLY DEEPENS EAST OF THE LAKES. THIS WILL
MAINTAIN A PROLONGED PERIOD OF NORTH-NORTHWEST FLOW ACROSS LAKE
MICHIGAN...THOUGH AGAIN WITH SPEEDS GENERALLY 15 KT OR LESS THROUGH
THE PERIOD.
OTHERWISE...IN THE NEAR TERM SOME PATCHY DENSE FOG WILL LINGER
ACROSS THE NORTHERN PART OF THE LAKE THIS MORNING.
RATZER
&&
.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 WEDNESDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 7
PM WEDNESDAY.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
113 AM CDT WED JUN 26 2013
.MESOSCALE DISCUSSION...
MCV MENTIONED IN PREVIOUS UPDATE CONTINUES TO TRACK TO THE EAST-
SOUTHEAST ACROSS THE CWA PER GOES SATELLITE EXTRAPOLATION.
EXPECTATION IS THAT THIS CIRCULATION WILL MOVE OUT OF THE
EAST/SOUTHEAST COUNTIES BY 10 PM CDT. CONVECTION WHICH CONTINUES
TO BUBBLE OVER LAKE MICHIGAN/NORTHWEST INDIANA AND OVER THE SOUTH
END OF THE LAKE WILL LIKELY CONTINUE FOR THE NEXT 1-2 HOURS AS THE
MCV COMPLETES ITS TRANSIT OF THE AREA BEFORE MOVING EAST OF THE
FORECAST AREA. SUBSIDENCE/STABILIZATION IN THE IMMEDIATE WAKE OF
THIS FEATURE WILL LIKELY SUPPRESS NEW DEVELOPMENT ACROSS THE
CENTRAL PART OF THE NRN IL CWA FOR A COUPLE OF HOURS...AND
THEREFORE AFTER COLLABORATION WITH SPC HAVE DECIDED TO REMOVE
LASALLE...KENDALL...GRUNDY AND WILL COUNTIES FROM SEVERE
THUNDERSTORM WATCH 363.
WHILE PREVIOUS CONVECTION HAS STABILIZED LOW LEVELS ACROSS THE
SOUTHERN TIER OF OUR CWA COUNTIES IN 363...INCREASING SOUTHERLY LOW
LEVEL JET AS NOTED IN VWP/S TO OUR WEST/SOUTHWEST HAS RESULTED IN
DEVELOPMENT OF NEW DEEP/STRONG CONVECTION ACROSS WESTERN IL AND
THESE STORMS MAY PERSIST ABOVE COLD POOL AND MAINTAIN A SEVERE
THREAT INTO THE PONTIAC/KANKAKEE AREAS IN ANOTHER 1-2 HOURS.
LOOKING FARTHER WEST...MID-LEVEL SHORT WAVE ACROSS THE MID-MISSOURI
VALLEY WAS NOTED IN GOES VAPOR IMAGERY. LAST VIS IMAGES OF THE
EVENING SHOW ACCAS FIELD OVER WESTERN/CENTRAL IA...WITH 3000-4000
J/KG OF MUCAPE INDICATED PER SPC/RAP MESOANALYSIS. CONVECTION
ALLOWING MODELS INCLUDING WRF-NMM AND HRRR RUNS CONTINUE TO IMPLY
THAT THE IA/WESTERN IL AREA WILL BECOME/REMAIN ACTIVE OVERNIGHT...
WITH ONE OR MORE CLUSTERS OF STORMS POTENTIALLY AFFECTING PARTS OF
THE CWA INTO EARLY WEDNESDAY MORNING. 23Z HRRR RUN SEEMS TO HAVE A
REASONABLE HANDLE ON THIS SCENARIO...WITH ACTIVITY CURRENTLY
DEVELOPING OVER WESTERN/CENTRAL IL PERHAPS AFFECTING OUR SOUTHERN
COUNTIES THROUGH 05-07Z...THEN DEPICTING DEVELOPMENT OVER
CENTRAL/EASTERN IA SPREADING ACROSS NRN IL DURING THE PRE-DAWN HOURS.
HEAVY RAINFALL/SEVERE RISK CONTINUE OVERNIGHT...WITH WARM/MOIST AND
UNSTABLE AIR MASS.
RATZER
&&
.DISCUSSION...
256 PM CDT
SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT...
THE ACTIVE WEATHER EXPECTED OVER THE NEXT 24 TO 30 HOURS...INCLUDING
THE SEVERE WEATHER AND FLASH FLOODING THREAT WILL BE THE FOCUS OF
THE SHORT TERM FORECAST.
DUE TO THE INCREASING THREAT FOR PERIODS OF VERY HEAVY RAINFALL IN
SLOW MOVING STORMS TONIGHT INTO WEDNESDAY...I HAVE EXTENDED THE
FLASH FLOOD WATCH FOR THE ENTIRE AREA AND EXTENDED THROUGH
WEDNESDAY.
REGIONAL SATELLITE WATER VAPOR IMAGERY INDICATES AN UPPER LEVEL
DISTURBANCE CURRENTLY MOVING INTO NORTHWESTERN ILLINOIS. AREA VWP
DATA ACROSS EASTERN IOWA AND SOUTHERN WISCONSIN INDICATE THAT THIS
DISTURBANCE IS ASSOCIATED WITH A MID LEVEL SPEED MAX AROUND 50 KT.
THIS IS RESULTING IN AROUND 40 KT OF 0-6 KM SHEAR...PER SPC
MESO-ANALYSIS. THE AIR MASS AHEAD OF THIS FEATURE...ACROSS NORTHERN
ILLINOIS...HAS BECOME INCREASINGLY UNSTABLE OVER THE PAST FEW
HOURS...WITH SURFACE TEMPERATURES IN THE LOW TO MID 80S AND DEW
POINTS IN THE LOWER 70S...ESPECIALLY TO THE SOUTH OF THE SURFACE
BOUNDARY...CURRENTLY IN PLACE ACROSS FAR NORTHERN ILLINOIS.
MODIFYING THE 12 UTC ILX SOUNDING...THIS RESULTS IN AROUND 3500 J/KG
OF MLCAPE WITH LITTLE TO NO CAPE. NOT SURPRISING...THAT
THUNDERSTORMS ARE BEGINNING TO FIRE ACROSS PORTIONS OF CENTRAL
ILLINOIS AS ASCENT CONTINUES TO OVERSPREAD THIS UNSTABLE
ENVIRONMENT. I EXPECT THIS TREND TO CONTINUE...ESPECIALLY ACROSS
SOUTHERN SECTIONS OF THE AREA...WITH THE POTENTIAL OF AN
ORGANIZING FORWARD PROPAGATING CONVECTIVE COMPLEX WITH STRONG
DAMAGING WINDS BEING THE MAIN THREAT. HOWEVER...THE THREAT FOR
SEVERE HAIL WILL ALSO BE A CONCERN...ESPECIALLY EARLY IN THE EVENT.
THIS ACTIVITY WILL LIKELY CONTINUE INTO THE EARLY EVENING.
ADDITIONAL ROUNDS OF CONVECTION ARE LIKELY AGAIN THIS EVENING AND
OVERNIGHT...WITH THE POTENTIAL FOR SLOW MOVING AND BACK BUILDING
THUNDERSTORMS. THE QUASI-ZONAL FLOW PATTERN ACROSS THE CONUS IS IN
THE PROCESS OF AMPLIFYING...IN RESPONSE TO AN UPPER LOW OVER THE
EASTERN PACIFIC. ULTIMATELY THIS WILL SET THE STAGE FOR A BUILDING
MID/UPPER LEVEL RIDGE ACROSS THE WESTERN CONUS AND FALLING HEIGHTS
ACROSS THE GREAT LAKES REGION. THIS PROCESS SHOULD ALLOW
ANOTHER...STRONGER SHORT WAVE...CURRENTLY NOTED IN THE WATER VAPOR
IMAGERY ACROSS THE PLAINS...TO MOVE ACROSS THE AREA BY WEDNESDAY. A
SOUTHWESTERLY LOW LEVEL JET WILL KICK UP AHEAD OF THIS FEATURE
DURING THE EVENING...AND GUIDANCE CONTINUES TO PLACE THE NOSE OF THIS
LOW LEVEL JET RIGHT ACROSS THE AREA TONIGHT. THIS COULD POTENTIALLY
LEAD TO A DECENT FLASH FLOODING EVENT FOR PORTIONS OF THE AREA
TONIGHT INTO WEDNESDAY...WITH A GOOD POTENTIAL FOR SLOW MOVING AND
BACK BUILDING THUNDERSTORMS. CORFIDI VECTORS ARE PROGGED TO BE 5
KT OR LESS TONIGHT AS THE JET VEERS WEST-SOUTHWESTERLY AND OFFSETS
THE CLOUD BEARING FLOW. CONSIDERING THIS...AND THE FACT THAT FLASH
FLOOD GUIDANCE REMAINS LOW ACROSS THE AREA...I DECIDED TO GO
WITH A FLASH FLOOD WATCH FOR THE ENTIRE AREA.
IT APPEARS THESE STORMS WITH HEAVY RAIN WILL CONTINUE INTO THE EARLY
MORNING HOURS ON WEDNESDAY AND THEN INTENSIFY IN STRENGTH BY THE
AFTERNOON...ESPECIALLY ACROSS MY SOUTHERN AND EASTERN AREAS. THIS
COULD ALSO LEAD TO ADDITIONAL SEVERE STORMS...ESPECIALLY SOUTH. IT
IS POSSIBLY THAT THE MORNING ACTIVITY COULD LIMIT THE SEVERE RISK TO
THE NORTH.
KJB
LONG TERM...THURSDAY THROUGH TUESDAY...
350 PM CDT
AMPLIFICATION OF THE WESTERN CONUS RIDGE AND EASTERN TROUGH WILL
BEGIN TO INFLUENCE THE LOCAL AREA BY LATE WEDNESDAY INTO THURSDAY
AFTER A SURFACE TROUGH PUSHES THROUGH THE AREA AND WINDS AT ALL
LEVELS TURN TO THE NORTHWEST. LOW LEVEL WARMTH AND HUMIDITY DO NOT
REALLY DEPART UNTIL FRIDAY WHEN THE EXPANDING EASTERN TROUGH PUSHES
THE UPPER JET SOUTH OF THE AREA AND USHERS IN DRIER AND MILDER AIR.
ON BOTH THURSDAY AND FRIDAY IT WOULD NOT TAKE MUCH OF A WRINKLE IN
THE UPPER FLOW TO SUPPORT AN AFTERNOON SHOWER...SO SLIGHT CHANCE
POPS HAVE BEEN MAINTAINED ON BOTH DAYS. BY THE WEEKEND THE
CONVECTIVE INSTABILITY APPEARS TO HAVE DECREASED...BUT THE PRESENCE
OF BOTH A SURFACE AND UPPER LEVEL TROUGH DROPPING SOUTH ACROSS THE
AREA WILL STILL SUPPORT LARGE SCALE LIFT...PRIMARILY TO THE SOUTH ON
SUNDAY. PRECIP CHANCES FINALLY DECREASE BY EARLY NEXT WEEK AS THE
SURFACE AND UPPER SUPPORT DIMINISH...BUT UNSEASONABLY COOL AIR
REMAINS IN PLACE WITH CONTINUED NORTH TO NORTHEASTERLY WINDS.
LENNING
JEE
&&
.HYDROLOGY...
REDEVELOPMENT OF THUNDERSTORMS LATER THIS AFTERNOON INTO TONIGHT
IS LIKELY...WITH PERIODS OF HEAVY RAINFALL EXPECTED TO ACCOMPANY
THESE THUNDERSTORMS. GUIDANCE CONTINUES TO FAVOR PRECIPITABLE
WATER VALUES AROUND 2.00". ANOTHER DECENT MID LEVEL DISTURBANCE
IS EXPECTED TO APPROACH THE AREA TONIGHT AND INTO WEDNESDAY...AND
THIS SYSTEM LOOKS TO INDUCE A SOUTHWESTERLY LOW LEVEL JET...THAT
COULD OFFSET THE FORWARD STORM MOTION...RESULTING IN SLOW MOVING
OR BACK BUILDING THUNDERSTORMS TONIGHT INTO WEDNESDAY. AT THIS
TIME...UNCERTAINTY REMAINS AS TO WHERE EXACTLY THE HEAVIEST RAIN
WILL FALL...BUT GUIDANCE CONTINUES TO HINT AT NORTHERN ILLINOIS
AND NORTHWESTERN INDIANA. THIS WILL HAVE TO BE WATCHED FOR
POSSIBILITY OF A FLASH FLOOD WATCH FOR MOST OF THE AREA AS
RAINFALL AMOUNTS IN EXCESS OF 2 INCHES IS CERTAINLY POSSIBLE
ACROSS PORTIONS OF THE AREA.
KJB/BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* TSRA LATE TONIGHT/EARLY WEDNESDAY MORNING.
* HEAVY RAIN AND MVFR VSBY LIKELY WITH THE TSRA.
* ADDITIONAL ROUND OF TSRA PSBL WEDNESDAY AFTERNOON.
* LAKE BREEZE PSBL WEDNESDAY AFTERNOON WITH WINDS BCMG E.
JEE
//DISCUSSION...UPDATED 06Z...
HIGH PRESSURE OVER THE SE US REMAINS IN PLACE WHILE A LOW OVER THE
NORTHEASTERN PLAINS SLIDES THROUGH THE WESTERN GREAT LAKES LATER
TODAY. CONVECTION IS CURRENTLY ON THE RADAR IN NORTHEAST IA AND
EAST CENTRAL IL/SOUTHERN IN. THE CONVECTION TO THE SOUTH SHOULD
REMAIN SOUTH OF THE TERMINALS. THE STORMS OVER IA ON THE OTHER
HAND SHOULD CONTINUE EASTWARD BEFORE BEGINNING TO MOVE TOWARD THE
SOUTHEAST. SCATTERED CONVECTION HAS ALSO BLOSSOMED AT THE NOSE OF
THE LOW LEVEL JET IN NORTHWEST IL AND SHOULD CONTINUE TO SEE MORE
SCATTERED CONVECTION. LASTLY...HAVE SEEN A FEW CELLS PULSE UP AND
THEN PULSE DOWN ARND DPA SO MOVED THE TEMPO FOR THUNDER UP BY AN
HOUR AT DPA.
AS FAR AS THE TAFS ARE CONCERNED...FEELING MUCH MORE CONFIDENT IN
TS IMPACTING THE TERMINALS BEFORE SUNRISE. KEPT A 2 HOUR WINDOW IN
THE TAFS SINCE STILL NOT HIGHLY CONFIDENT IN WHEN THE TS WILL MAKE
IT TO THE TERMINALS. ALSO KEPT A PERIOD OF RAIN BEHIND THE
THUNDERSTORMS AS THE IA CONVECTION SHOULD CONSOLIDATE AND HAVE A
REGION OF RAIN SHOWERS BEHIND IT. ODDS ARE THE RAIN WILL END
SOONER THAN INDICATED IN THE TAFS.
SOUTH WINDS ARND 10 KT ARE EXPECTED TOMORROW...WITH A LAKE BREEZE
DEVELOPING IN THE AFTN. THINKING THE WIND SHIFT WILL BE SIMILAR TO
YESTERDAY WITH A BRIEF PERIOD OF DUE EAST WINDS AND A MUCH LONGER
PERIOD OF SE WINDS BEHIND THE LAKE BREEZE. THE LAKE BREEZE SHOULD
MAKE IT THROUGH ALL OF THE EASTERN TERMINALS.
THE LOW/TROUGH MOVES THROUGH TOMORROW WITH YET ANOTHER ROUND OF
TSRA EXPECTED. THINKING TS IS PSBL AT RFD ARND 19Z AND THEN
REACHING ORD BY 21Z. THE COMBINED FORCING OF THE TROUGH AND LAKE
BREEZE COULD LEAD TO SOME VERY HEAVY RAINFALL AND MVFR VSBY. STILL
NOT VERY CONFIDENT IN TIMING AND COVERAGE OF TS THIS AFTERNOON SO
LEFT VCTS IN THE TAFS. WINDS WILL TURN NW TO W BEHIND THE TROUGH
AND SKIES WILL BEGIN TO CLEAR OUT LATE IN THE EVENING.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM-HIGH CONFIDENCE IN TSRA TONIGHT...MEDIUM CONFIDENCE WITH
TIMING.
* MEDIUM-LOW CONFIDENCE IN HOW MUCH AND HOW LONG RAIN WILL PERSIST
BEHIND THE THUNDERSTORMS.
* MEDIUM CONFIDENCE IN COVERAGE AND TIMING OF TSRA WEDNESDAY
AFTERNOON.
* MEDIUM CONFIDENCE IN TIMING OF LAKE BREEZE AND WINDS MAY BE MORE
SE THAN FORECAST BEHIND THE LAKE BREEZE.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY AND FRIDAY...GENERALLY VFR OUTSIDE OF COUPLE OF BRIEF PERIODS
OF THUNDERSTORMS.
SATURDAY THROUGH MONDAY...GENERALLY VFR. A COUPLE OF BRIEF PERIODS
OF SHOWERS.
ED F
&&
.MARINE...
234 PM CDT
A LARGE RIDGE OF HIGH PRESSURE WILL PERSIST ACROSS THE SOUTHEAST
STATES THROUGH MID WEEK WHILE A TROUGH OF LOW PRESSURE OVER THE
CENTRAL PLAINS SHIFTS INTO THE UPPER MISSOURI VALLEY THIS EVENING
AND THE UPPER MISSISSIPPI VALLEY WEDNESDAY. THIS WILL KEEP
GENERALLY SOUTHERLY WINDS OVER THE LAKE THROUGH WEDNESDAY. THE
TROUGH WILL THEN DRIFT ACROSS LAKE MICHIGAN WEDNESDAY
EVENING...WITH WINDS GRADUALLY SHIFTING TO MORE NORTHERLY. THE
SOUTHERN END OF THE TROUGH WILL CLOSE OFF INTO A CLOSED LOW OVER
THE EASTERN GREAT LAKES THURSDAY AFTERNOON AND TRACK NORTH INTO
SOUTHERN QUEBEC BY FRIDAY NIGHT. A SECONDARY SURGE OF COOLER AIR
WILL PUSH ACROSS THE LAKE INCREASING WINDS TO 15 TO 20 KT.
NORTHERLY WINDS OF 10 TO 15 KT WILL PERSIST OVER THE LAKE THROUGH
THE END OF THE PERIOD.
KREIN
&&
.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 WEDNESDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 7
PM WEDNESDAY.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
1207 AM CDT WED JUN 26 2013
.DISCUSSION...
ISSUED 900 PM CDT TUE JUN 25 2013
THE STORMS HAVE BECOME LESS NUMEROUS IN COVERAGE OVER THE LAST
COUPLE OF HOURS...ALTHOUGH INDIVIDUAL CLUSTERS OF STORMS HAVE
MAINTAINED SOME VIGOROUS UPDRAFTS WITH LARGE AMOUNTS OF MOISTURE
ALOFT AND VERY HEAVY RAINFALL AND SOME HAIL. WITH COOLING OF
SURFACE TEMPS...WE ARE LOSING SURFACE BASED CAPE. HOWEVER...STORMS
APPEAR TO BE SURVIVING BY BECOMING ELEVATED...WITH A CONTINUED
THREAT OF VERY HEAVY RAIN AND SOME HAIL...BUT LOWER CHANCES OF
WIND DAMAGE.
AS FOR THE TRENDS FOR THE REST OF THE NIGHT...WITH EACH SUCCESSIVE
HOUR OF THE HRRR MODEL...IT HAS SLOWED DOWN THE ARRIVAL OF OUR
LATE NIGHT CONVECTIVE COMPLEX FROM IOWA. IT HAS PICKED UP ON THE
RENEWED CONVECTION IN OUR WESTERN COUNTIES AND IT SHOWS THEM
PROGRESSING TO THE NORTHEAST THEN EAST. A LARGER COMPLEX OF STORMS
IS STILL INDICATED TO ARRIVE IN OUR NW COUNTIES FROM THE NORTHWEST
TOWARD 11Z/6AM. WILL KEEP AND EYE ON TIMING BASED ON SATELLITE AND
RADAR TRENDS...BUT FOR NOW WILL ADJUST LIKELY POPS TO LATER
TONIGHT FOR THE NW COUNTIES. WILL ALSO ADJUST THE WED MORNING
LIKELY POPS BACK TO THE NORTHWEST INSTEAD OF JUST SOUTHEAST OF
I-70. WE MAY BE SEEING THE HRRR CONTINUE TO ADJUST THE TIMING OF
THE NEXT COMPLEX UNTIL IT BECOMES OUR MAIN SEVERE WEATHER PRODUCER
DURING THE DAY ON WEDNESDAY.
UPDATED WEATHER INFORMATION IS ALREADY AVAILABLE.
&&
.AVIATION...
ISSUED 1205 AM CDT WED JUN 26 2013
MAIN EMPHASIS IN THIS FORECAST PERIOD CONTINUES TO REVOLVE AROUND
CONVECTION COVERAGE AND AFFECT ON CIGS AND VSBYS.
LATEST SHORT TERM MODELS CONTINUE TO SUGGEST ANOTHER COMPLEX OF
STORMS DEVELOPING ACROSS IOWA THEN TRACKING E/SE INTO CENTRAL
ILLINOIS TOWARD DAWN. WILL CARRY PREDOMINANT THUNDER AFTER 11Z AT
KPIA...THEN AFTER 13Z FURTHER EAST AT KDEC. AFTER A 3-4 HOUR
PERIOD OF CONVECTION WEDNESDAY MORNING...A LULL IN THE ACTIVITY
MAY DEVELOP. DUE TO UNCERTAINTY...WILL CONTINUE TO ONLY MENTION
VCTS FROM MID MORNING THROUGH MID-AFTERNOON WHEN COLD FRONT PUSHES
THROUGH THE AREA AND SHIFTS BETTER STORM CHANCES FURTHER EAST INTO
INDIANA. WINDS WILL BE SOUTHERLY AT LESS THAN 10KT TONIGHT...THEN
WILL BECOME WESTERLY BY WEDNESDAY AFTERNOON WITH SPEEDS AROUND
10 KTS WITH WIND DIR/SPEED QUITE VARIABLE IN AND NEAR TSRA.
SMITH
&&
.PREV DISCUSSION...
ISSUED 300 PM CDT TUE JUN 25 2013
SEVERE STORM CHANCES WILL REMAIN THE FOCUS OVER THE NEXT 2 DAYS.
FLASH FLOODING POTENTIAL TONIGHT IN THE NORTH WILL ALSO BE A
CONCERN. BEYOND THAT...AN AIRMASS CHANGE IS PROJECTED FOR LATE
THIS WEEK AND WEEKEND. HOWEVER...A CUTOFF UPPER LOW LINGERING OVER
THE HEARTLAND WILL KEEP SHOWERS AND EVEN ISOLATED THUNDERSTORMS IN
THE FORECAST THROUGH EARLY NEXT WEEK.
SHORT TERM...TONIGHT THROUGH FRIDAY.
WE DECIDED TO PUT OUR 5 NORTHERN COUNTIES IN A FLASH FLOOD THROUGH
TONIGHT DUE TO PREVIOUS 3-5 INCH RAINS EARLY MONDAY MORNING AND
THE POTENTIAL FOR ADDITIONAL VERY HEAVY RAINFALL RATES UP TO 2
INCHES AN HOUR WITH ANY THUNDERSTORMS THROUGH TONIGHT. PWATS
REMAIN IN THE 1.7-1.9" RANGE...AND PERIODIC STORMS IN AN EAST-WEST
LINE ACROSS N IL IS POSSIBLE.
ADJUSTING OUR 12Z SOUNDING FOR CURRENT CONDITIONS SHOWS ML-CAPE
VALUES APPROACHING 3500 J/KG ACROSS OUR AREA...WITH LITTLE TO NO
CIN. VARIOUS BOUNDARIES ACROSS THE AREA FROM YESTERDAYS CONVECTION
HAVE ALREADY BEGUN TO FIRE BETWEEN 18-19Z. WATER VAPOR PIX CONFIRM
A SHORTWAVE IN THE FLOW ACROSS IOWA PROGRESSING EAST-NE. THAT WAVE
SHOULD HELP RAMP UP THE COVERAGE OF STORMS AND POSSIBLY PUSH US
INTO SEVERE WEATHER MODE. FREEZING LEVEL AT 14.4K FT MEANS HAIL
WILL NEED INTENSE UPDRAFTS TO REACH SEVERE LEVELS /1"+/...BUT WE HAVE
THE CAPE TO ACCOMPLISH THAT WITH THE STRONGEST STORMS. WIND SHEAR
WILL BE GRADUALLY INCREASING AS WE HEAD INTO THIS EVENING...SO
ROTATING SUPERCELLS WILL BE POSSIBLE AS THE EVENT PROGRESSES.
THE LATEST HRRR IS INDICATING TWO PERIODS OF STORMS POSSIBLE. WE
EXPECT A WAVE OF STORMS THIS EVENING THAT MAY BE FOLLOWED BY
ANOTHER BOWING COMPLEX OF STORMS ROLLING INTO OUR AREA FROM IOWA
REACHING KNOX COUNTY AROUND 06Z/1AM. THOSE STORMS MAY BE STILL
AFFECTING OUR COUNTIES SE OF I-70 WED MORNING BEFORE THEY DEPART
INTO INDIANA. WE WENT WITH SOME LIKELY POPS IN THE MORNING TO
ACCOUNT FOR THAT.
THEN A BREAK IN THE ACTION MAY DEVELOP THE REST OF WED MORNING AS
THE ATMOSPHERE RECHARGES FOR THE AFTERNOON WAVE OF STRONG TO
SEVERE STORMS. IT APPEARS THAT A LINE OF STORMS WILL DEVELOP
ACROSS WEST CENTRAL ILLINOIS BY MID AFTERNOON...THEN PROGRESS
EASTWARD. AN INCREASING LLJ IS EXPECTED TO COINCIDE WITH UPPER
LEVEL WINDS VEERING TO THE NORTHWEST. THAT WILL INCREASE SHEAR AND
HELICITY PARAMETERS AND RAMP UP THE THREAT OF ROTATING STORMS AND
POSSIBLY A FEW TORNADOES...MAINLY EAST OF I-55. WE INCREASED POPS
TO LIKELY IN THE EAST WEDNESDAY AFTERNOON TO ACCOUNT FOR THAT
PERIOD OF SEVERE STORMS.
STORMS SHOULD BE WINDING DOWN WED EVENING AS THE COMPLEX MOVES
INTO INDIANA. THURSDAY AND THURSDAY NIGHT SHOULD BE PRIMARILY
DRY...BUT A FEW DAYTIME SHOWERS WILL BE POSSIBLE IN THE EAST AS
THE UPPER WAVE LINGERS ACROSS THE EAST...AND A FEW SHOWERS MAY
REACH OUR SOUTHWESTERN COUNTIES THUR NIGHT AHEAD OF THE NEXT UPPER
LEVEL WAVE. WE KEPT SLIGHT CHANCE POPS EVERYWHERE ON FRIDAY AS
THAT WAVE PROGRESSES ACROSS IL. PRECIP SHOULD BE SPOTTY...AS
COOLER AND LESS HUMID AIR BEGINS TO FLOW INTO THE AREA ON
NORTHWEST WINDS.
LONG TERM...SATURDAY THROUGH TUESDAY.
WE EXPECT TO BE IN AN EXTENDED PERIOD UP UPPER LEVEL TROUGHING AS
A CUT OFF LOW DEVELOPS ACROSS THE WESTERN GREAT LAKES AND
RETROGRADES AND OSCILLATES OVER THE MIDWEST THROUGH EARLY NEXT
WEEK. PERIODS OF SLIGHT CHANCE AND CHANCE POPS WILL PEPPER THE
EXTENDED FORECAST AS A RESULT...DUE TO VARIOUS SHORTWAVE ROTATING
AROUND THE UPPER LOW. RELATIVELY COOL AIR ALOFT WILL ALSO KEEP
LAPSE RATES MODERATELY HIGH...AND FAVORABLE FOR ANY SUNS HEATING
TO CREATE SHOWERS AND ISOLATED STORMS.
TEMPS WILL SETTLE OUT WITH HIGHS IN THE UPPER 70S TO NEAR 80 AND
LOWS IN THE LOWER 60S FOR MUCH OF THE EXTENDED PERIOD.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 7 AM CDT THIS MORNING FOR ILZ027>031.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
329 AM CDT WED JUN 26 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 305 AM CDT WED JUN 26 2013
0Z UPPER AIR OBSERVATIONS SHOWED A RATHER SHARP MID LEVEL WAVE
OVER THE MISSOURI RIVER WITH A NARROW AXIS OF WARM AIR ADVECTION
AHEAD OF IT AND ELEVATED CONVECTION BLOSSOMED OVERNIGHT IN
NORTHERN MISSOURI. A VERY MODIFIED COLD FRONT WITH THIS WAVE WAS
BISECTING KANSAS FROM SOUTHWEST TO NORTHEAST AT 07Z. NEARBY 0Z
850MB TEMPS WERE 20C AT KTOP...26C BEHIND THE FRONT AT KLBF...AND
31C AND KDDC. RECENT AREA PROFILERS AND RADARS INDICATE MODERATE
WESTERLY FLOW AT THIS LEVEL BRINGING WARMER AIR INTO EASTERN
KANSAS.
MID LEVEL SUBSIDENCE BEHIND THE WAVE AND WEAK LOW LEVEL CONVERGENCE
SHIFTING SOUTHEAST OF EAST CENTRAL KANSAS BY EARLY AFTERNOON SHOULD
KEEP ANY PRECIP IN CHECK FOR TODAY AND TONIGHT. 850MB TEMPS SHOULD
BE A FEW DEGREES WARMER THIS AFTERNOON ESPECIALLY IN EASTERN
LOCATIONS WITH HIGHS SEVERAL DEGREES WARMER THERE IN ORDER COMPARED
TO THE TUESDAY. NORTHERLY LOW LEVEL FLOW BEHIND THE MODIFIED FRONT
SHOULD KEEP AFTERNOON DEWPOINTS IN THE 60S FOR THE MOST PART AND
HEAT INDICES BELOW EXTREME VALUES. LIGHT WINDS AND ONLY SOME CIRRUS
EXPECTED TONIGHT WITH WEAK SURFACE HIGH NEARBY. DROPPED LOWS A FEW
DEGREES WITH THESE FEATURES IN MIND.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 305 AM CDT WED JUN 26 2013
THURSDAY LIKELY TO BRING BOTH THE THE HOTTEST DAY OF THE WEEK TO
THE AREA AS WELL AS THE GREATEST RISK FOR SEVERE WEATHER. 850MB
THERMAL RIDGE NOSES EASTWARD ACROSS THE STATE WITH NEAR 30C AT THE
WESTERN FRINGES OF THE CWA. TEMPERATURES OUT IN THE WESTERN
COUNTIES EXPECTED TO TOP 100 ALONG/WEST OF MANHATTAN WITH UPPER
90S EASTWARD. EVEN WITH MIXING DOWN SOME DRIER DEWPOINTS...HEAT
INDICES STILL RUNNING 104 TO 106 FOR THE ENTIRE AREA. SEVERE
THREAT INCREASES AS A POTENTIAL MCS IS PROGGED TO DEVELOP OVER
NEBRASKA ALONG THE THERMAL GRADIENT ON THE NOSE OF THE LLJ BY
12Z...AND PROPAGATE SOUTHEAST AS THE JET VEERS ALONG THE
BOUNDARY INTO NE KS / WRN MO. SURFACE FRONT ALSO ASSOCIATED WITH
THIS FEATURE MOVES SOUTHWARD THROUGH THE FA DURING PEAK HEATING.
CONCERNS ARE THAT CONSIDERABLE DRY AIR DEEP IN THE BOUNDARY LAYER
COUPLED WITH AVAILABLE INSTABILITY OF 1500-3000K/KG ATOP INVERTED
V SOUNDINGS MAY BRING A SIGNIFICANT WIND THREAT FROM ANY
CONVECTION THAT DEVELOPS OVER EASTERN KS IN THE AFTERNOON AND
EVENING HOURS. WILL MONITOR AS CONDITIONS DEVELOP.
INCOMING HIGH PRESSURE FRIDAY STILL ON THE WARM LEADING EDGE OF
THE HIGH...AND TEMPERATURES STILL EXPECTED TO REACH LOWER 90S IN
ABUNDANT SUNSHINE AND GOOD MIXING. PATTERN THEN SETS UP FOR A COOL
LATE JUNE EARLY JULY PATTERN AS WESTERN RIDGE AMPLIFIES AND ENERGY
ROTATING AROUND THE PERIPHERY INTO THE EASTERN TROF STRENGTHENS
THE AMPLIFICATION IN THE PATTERN...LEAVING PLAINS STATES IN
NORTHERLY FLOW THROUGH THE END OF THE FORECAST PERIOD. AS
COMPARED TO THE FORECAST HOT WEATHER FOR THURSDAY...850MB TEMPS
ARE PROGGED TO BE 14C BY NEXT TUESDAY AFTERNOON...WITH HIGHS
FORECAST IN THE LOWER 80S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1122 PM CDT TUE JUN 25 2013
WITH WATER VAPOR SHOWING AN UPPER LEVEL TROUGH PASSING EAST OF THE
MO RIVER AND THE DIURNALLY DRIVEN CONVECTION IN SOUTH CENTRAL KS
DISSIPATING...THINK VFR CONDITIONS WILL PREVAIL OVERNIGHT. BOTH
THE NAM AND RAP SHOW THE BEST COMBINATION OF ISENTROPIC UPGLIDE
AND SATURATION TO REMAIN OVER NORTHERN MO AND MOVING TO THE EAST
OVERNIGHT. WITH NEW ELEVATED STORMS ALREADY EAST OF THE MO
RIVER...IT IS HARD TO SEE ANYTHING FORMING IN KS. WINDS SHOULD
GRADUALLY DIMINISH OVERNIGHT AS THE SFC LOW CONTINUES TO FILL AND
THE PRESSURE GRADIENT WEAKENS.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...65
LONG TERM...67
AVIATION...WOLTERS
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1122 PM CDT TUE JUN 25 2013
.UPDATE...
ISSUED AT 726 PM CDT TUE JUN 25 2013
HAVE UPDATED THE FORECAST TO TAKE OUT THE SLIGHT CHANCE OF
THUNDERSTORMS FOR THE EARLY EVENING. SURFACE OBS AND LAPS ANALYSIS
SHOWS THE STRONGER LOW LEVEL CONVERGENCE BETWEEN MCPHERSON AND
PRATT ALONG THE SURFACE BOUNDARY. ISOLATED CONVECTION HAS FORMED
IN THIS AXIS OF LOW LEVEL CONVERGENCE. WITH THE LOW LEVEL
MOISTURE FLUX LESS IMPRESSIVE ACROSS NORTH CENTRAL KS AND THE CU
FIELD SHOWING LITTLE VERTICAL DEVELOPMENT OUTSIDE OF THE ENHANCED
CONVERGENCE NEAR HUTCHINSON...THINK ADDITIONAL DEVELOPMENT IS
UNLIKELY AS THE BOUNDARY LAYER STARTS TO STABILIZE WITH THE LOSE
OF DAY TIME HEATING.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 343 PM CDT TUE JUN 25 2013
LATEST WATER VAPOR LOOP SHOWS A WAVE MOVING ACROSS WESTERN KANSAS.
SPEED LOOP OF VISIBLE SATELLITE SHOWS SOME CIRCULATION OVER NORTH
CENTRAL KANSAS WITH A CU FIELD TO ITS EAST AND NORTHEAST. SURFACE
TROUGH FROM A LOW IN SOUTHWEST KANSAS NORTHEAST INTO NEBRASKA.
LATEST MESO ANALYSIS CONTINUES TO SHOW DEEP MOISTURE OVER EASTERN
KANSAS. DEEP MOISTURE CONVERGENCE WAS OCCURRING OVER NORTHEAST AND
NORTH CENTRAL KANSAS AHEAD OF THE ABOVE MENTIONED FEATURE. EML WAS
WORKING ITS WAY ACROSS SOUTH CENTRAL KANSAS THIS AFTERNOON WHERE 15
DEGREE CELSIUS AIR RESIDES.
THE HRRR AND WRF SHOW SOME ISOLATED CONVECTION DEVELOPING NORTH OF
I-70 LATE THIS AFTERNOON AND EVENING IN NORTH CENTRAL AND NORTHEAST
KANSAS. HAVE ONLY ABOUT A 10 TO 15 PERCENT CHANCE OF A THUNDERSTORM
IN THE FORECAST FOR A FEW HOURS THIS EVENING. ATMOSPHERE REMAINS
UNSTABLE WITH LITTLE TO NO CONVECTIVE INHIBITION. 0-6KM SHEAR NEAR
40 KTS SO COULD SEE A SUPERCELL OR TWO DEVELOP. LOW LEVEL JET VEERS
TONIGHT WITH THE DEEPER MOISTURE MOVING OFF TO THE EAST. A COLD
FRONT IN THE WESTERN PLAINS WILL MOVE SOUTHEAST AND ACROSS NORTH
CENTRAL AND NORTHEAST KANSAS LATER TONIGHT THROUGH MID DAY
WEDNESDAY. SURFACE HIGH PRESSURE WILL MOVE IN BEHIND THE FRONT ON
WEDNESDAY. TEMPERATURES WILL BE MILD AGAIN TONIGHT WITH LOWS MAINLY
IN THE 70S. HIGHS ON WEDNESDAY WILL BE IN THE MID 90S IN THE
NORTHEAST CORNER TO NEAR 100 IN NORTH CENTRAL KANSAS. AFTERNOON HEAT
INDICES IN THE 98 TO 104 DEGREE RANGE ARE EXPECTED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 343 PM CDT TUE JUN 25 2013
THE LLVL FLOW VEERS AROUND TO THE SOUTHEAST THEN SOUTH TO SOUTHWEST
WEDNESDAY NIGHT INTO THURSDAY...WARMER AIR AND DEEPER MOISTURE WILL
ADVECT BACK INTO THE COUNTY WARNING AREA. A STRONG 850MB THERMAL
AXIS WILL PUSH WARMER TEMPS NORTHEAST INTO THE CWA...ESPECIALLY THE
SOUTHWEST COUNTIES WHERE HIGHS IN THE 100-103 RANGE SHOULD BE COMMON
AS MIXING ACROSS THE AREA BY AFTERNOON DEEPENS SUBSTANTIALLY. THIS
WILL NOT ONLY RAISE TEMPS...BUT AT THE SAME TIME...LOWER
DEWPOINTS...MAINLY OVER THE WESTERN COUNTIES. HEAT INDICES THURSDAY
WILL COMMONLY BE IN THE 100-105 RANGE. A SUBSTANTIAL EML WILL BE IN
PLACE TO THE START THE AFTERNOON...BUT BY LATE IN THE DAY OVER THE
NORTHERN COUNTIES...IT WILL LIKELY ERODE WITH ISOLATED THUNDERSTORMS
POSSIBLE AND WILL CARRY A SLIGHT CHANCE POP. ALTHOUGH WINDS ALOFT
WILL NOT BE ESPECIALLY STRONG...AN AREA OF HIGH CAPE VALUES AND
INCREASING DIRECTIONAL SHEAR THROUGH 6KM WILL DEVELOP ALONG AND
AHEAD OF THE BOUNDARY SLIPPING SOUTHWARD LATE IN THE DAY AND
EVENING. WOULD EXPECT SOME INCREASE IN COVERAGE OF ANY LATE
AFTERNOON CONVECTION. ALTHOUGH HAIL IS POSSIBLE...A DEEP LAYER OF
NEARLY ADIABATIC LAPSE RATES COULD MAKE STRONG WINDS GUSTS THE
PRIMARY HAZARD FOR ANY CONVECTION THAT MAY DEVELOPS. MODELS SEEM A
FAIRLY GOOD AGREEMENT THAT ANY CONVECTION THAT DEVELOPS...SHOULD BE
SOUTH OF THE CWA BY SUNRISE FRIDAY AS THE BOUNDARY MOVES SOUTHWARD.
WILL KEEP THE HIGHEST POPS OVER THE FAR NORTHEAST/EASTERN COUNTIES.
IT SHOULD ALSO MARK THE BEGINNING OF A GRADUAL DECLINE IN BOTH
TEMPERATURES AND DEWPOINTS AS A LARGE SCALE UPPER TROUGH DEEPENS
THROUGH THE WEEKEND OVER THE EASTERN CONUS. DEWPOINTS WILL COMMONLY
BE IN THE 50S TO NEAR 60 DEGREES THROUGH THE WEEKEND. ALTHOUGH IT
WILL STILL BE THE LOW TO MIDDLE 90S MOST AREAS FRIDAY...HIGHS IN THE
80S WILL BE THE RULE THROUGH THE WEEKEND INTO EARLY NEXT WEEK. WILL
CARRY A SLIGHT CHANCE FOR THUNDERSTORMS OVER THE FAR NORTHEAST ON
SUNDAY. ALTHOUGH CANNOT TOTALLY RULE OUT ISOLATED CONVECTION IN THE
NORTHWEST FLOW REGIME OVER THE AREA...DRIER AIR OVER THE AREA AND
THE LACK OF ANY CONSISTENT FORCING MECHANISM TO DEVELOP PRECIP
WARRANTS KEEPING THE REMAINDER OF THE FCST DRY AT THIS POINT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1122 PM CDT TUE JUN 25 2013
WITH WATER VAPOR SHOWING AN UPPER LEVEL TROUGH PASSING EAST OF THE
MO RIVER AND THE DIURNALLY DRIVEN CONVECTION IN SOUTH CENTRAL KS
DISSIPATING...THINK VFR CONDITIONS WILL PREVAIL OVERNIGHT. BOTH
THE NAM AND RAP SHOW THE BEST COMBINATION OF ISENTROPIC UPGLIDE
AND SATURATION TO REMAIN OVER NORTHERN MO AND MOVING TO THE EAST
OVERNIGHT. WITH NEW ELEVATED STORMS ALREADY EAST OF THE MO
RIVER...IT IS HARD TO SEE ANYTHING FORMING IN KS. WINDS SHOULD
GRADUALLY DIMINISH OVERNIGHT AS THE SFC LOW CONTINUES TO FILL AND
THE PRESSURE GRADIENT WEAKENS.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WOLTERS
SHORT TERM...53
LONG TERM...63
AVIATION...WOLTERS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
156 AM EDT WED JUN 26 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 430 PM EDT TUE JUN 25 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A LOW AMPLITUDE PATTERN WITH A
TROUGH INTO THE PAC NW AND A RIDGE FROM THE UPPER MS VALLEY INTO
MANITOBA. THE MAIN UPSTREAM SHORTWAVE TROUGH EXTENDED FROM ERN
MONTANA INTO WRN SD. AT THE SFC...A WEAK RIDGE AND LIGHT PRES
GRADIENT PREVAILED OVER THE THE REGION ALLOWING PROMINENT LAKE
BREEZES TO DEVELOP. CAPPING HAS BEEN STRONG ENOUGH TO SUPPRESS
CONVECTION THROUGH 20Z DESPITE LOW LEVEL CONV...INLAND MLCAPE VALUES
TO NEAR 1500 J/KG AND CU/TCU LINE DEVELOPMENT. MIXING HAS ALSO BEEN
STRONG ENOUGH TO DROP DEWPOINTS INTO THE MID AND UPPER 50S NEAR THE WI
BORDER
TONIGHT...POTENTIAL REMAINS FOR SOME ISOLD SHRA/TSRA
DEVELOPMENT...MAINLY OVER THE SOUTH NEAR THE LAKE BREEZE BOUNDARIES.
WITH THE LOSS OF DAYTIME HEATING...ANY PCPN CHANCES WILL ALSO
DIMINISH THIS EVENING. EVEN WITH FAVORABLE RADIATIONAL COOLING
OVERNIGHT...ENOUGH LOW LEVEL MOISTURE REMAINS TO KEEP MIN TEMPS FROM
DROPPING MUCH BELOW 60F. SOME PATCHY FOG MAY ALSO DEVELOP.
WED...THE NRN PLAINS SHRTWV AND ASSOCIATED SFC TROUGH MOVING INTO
THE WRN LAKES WILL BE THE FOCUS FOR SHRA/TSRA DEVELOPMENT. THE
MODELS WERE IN RELATIVELY GOOD AGREEMENT BRINGING THE HIGHER PCPN
CHANCES INTO THE WEST HALF OF THE CWA DURING THE AFTERNOON. THE
AIRMASS OVER REGION SHOULD AGAIN ALLOW TEMPS TO CLIMB INTO THE LOWER
80S INLAND AND BEFORE LAKE BREEZES TAKE OVER. MLCAPE VALUES MAY
AGAIN CLIMB TO AROUND 1500 J/KG BUT RELATIVELY MODEST SHEAR VALUES
WILL LIMIT STRONG/SEVERE STORM POTENTIAL.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 430 PM EDT TUE JUN 25 2013
OVERALL PATTERN WILL EVOLVE INTO AN AMPLIFIED ONE FOR LATE JUNE
STANDARDS DURING THE LATE WEEK PERIOD WITH INTENSE UPPER RIDGING
DEVELOPING OVER THE WESTERN U.S. AND TROUGHING DEVELOPING OVER THE
GREAT LAKES AND EASTERN U.S. AS HAS BEEN THE CASE OVER THE LAST
SEVERAL DAYS TIMING OF A BETTER PRECIP CHANCES DURING THE NEXT
COUPLE OF DAYS WILL REMAIN A CHALLENGE. CONFIDENCE IS PRETTY HIGH
THAT ALL AREAS WILL SEE AT LEAST SOME RAINFALL BETWEEN THE WEDNESDAY
NIGHT THROUGH SATURDAY TIME PERIOD. HOWEVER...MORE OF THAT TIME WILL
BE DRY RATHER THAN RAINY.
WHILE SCATTERED POPS SEEM THE WAY TO GO FOR THIS TIME PERIOD...WILL
GO WITH SLIGHTLY HIGHER POPS DURING THE WED NIGHT TIME PERIOD AS
SHORTWAVE ENERGY BEGINS TO CARVE OUT UPPER TROUGHING OVER THE GREAT
LAKES. WILL ALSO GO ON THE HIGHER END OF CHANCE POPS FOR FRIDAY INTO
SATURDAY AS MAIN TROUGH AXIS MOVES THROUGH THE AREA. A SCATTERING
OF POPS DURING THE OTHER PERIODS SEEMS REASONABLE.
WITH LIMITED INSTABILITY AND SHEAR EXPECTED...THUNDER CHANCES WILL BE
MORE IN THE ISOLATED TO SLIGHT CHANCE RANGE.
HIGH PRESSURE AND DRIER AIR SHOULD BEGIN PUSHING INTO THE AREA FROM
THE NORTH BY LATE IN THE DAY SATURDAY ENDING THE RAIN CHANCES.
UPPER TOUGHING WILL REMAIN OVER THE AREA INTO EARLY NEXT WEEK
KEEPING TEMPERATURES AT TO JUST SLIGHTLY BELOW NORMAL THROUGH THE
WEEKEND INTO MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 155 AM EDT WED JUN 26 2013
THERE MAY BE SOME RADIATIONAL FOG (MVFR VIS) OVERNIGHT AT KIWD/KSAW
AND PERHAPS KCMX. OTHERWISE...EXPECT VFR CONDITIONS THRU AT LEAST
MID AFTN. APPROACHING DISTURBANCE SHOULD BRING SHRA/SCT TSRA INTO
UPPER MI LATER THIS AFTN. INCLUDED SHRA/VCTS AND MVFR CONDITIONS AT
KIWD/KCMX LATE AFTN/EARLY EVENING AND AT KSAW MID TO LATE EVENING.
SHRA/SCT TSRA SHOULD BE IN THE AREA FOR SEVERAL HRS. PROVIDED RAIN
DOES OCCUR AT KCMX...CONDITIONS MAY FALL TO IFR OR LWR ONCE PCPN
ENDS THIS EVENING AS WINDS SHOULD HAVE SOME UPSLOPE COMPONENT OFF
THE LAKE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 430 PM EDT TUE JUN 25 2013
OVERALL...WINDS ARE EXPECTED TO BE BELOW 20KTS THROUGH THE PERIOD AS
THE PRESSURE PATTERN REMAINS FAIRLY WEAK ACROSS THE AREA. WITH THE
WARM MOIST AIR OVER THE UPPER GREAT LAKES...WILL CONTINUE TO MENTION
PATCHY/AREAS OF FOG THROUGH WEDNESDAY NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...MZ
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DULUTH MN
1231 AM CDT WED JUN 26 2013
.AVIATION...06Z TAF ISSUANCE...
EARLY MORNING BR/FG EXPECTED AT KHYR/KDLH/KHIB WITH POTENTIAL FOR
CEILINGS TO LOWER TO IFR/LIFR. NOT AS CONFIDENT ON FG/BR AT KHIB
HOWEVER CLIMO FAVORS AT LEAST A TEMPO IFR VIS. OTHERWISE MAIN
FEATURE WILL BE AREAL COVERAGE/TIMING OF CONVECTION WITH
APPROACHING FRONTAL SYSTEM. MDLS STILL VARY ON TIMING OF MAIN AXIS
OF MOISTURE/LIFT SO HAVE MAINTAINED THE PROB30 WORDING FOR ALL
SITES. APPEARS THAT A 6HR WINDOW OF OPPORTUNITY WILL EXIST BEFORE
FROPA/WINDSHIFT TO SW AND WEST OCCURS LATER IN THE AFTN...EXCEPT
AT KHYR WHERE FROPA WILL BE LATER.
&&
.PREV DISCUSSION... /ISSUED 1100 PM CDT TUE JUN 25 2013/
UPDATE...ADDED PATCHY FOG TO WISCONSIN ZONES AND NEAR TWIN
PORTS AFTER 08Z PER SFC T/TD SPREADS AT THIS HOUR. LATEST HRRR 3KM
FCST OF LOWERING VISIBILITY ALSO SUPPORTS THIS IDEA ALONG WITH
PERSISTENCE FROM PREVIOUS NIGHTS ALTHOUGH EVENTUALLY MORE HIGH LVL CLOUD
COVER WILL WORK ITS WAY IN FROM THE WEST. CONVECTIVE COMPLEXES
CONTINUE NEAR SFC LOW/TROF OVER ERN NODAK/MN BORDER IN AN AREA OF
MAXIMUM 85H MSTR TRANSPORT AND WELL DEFINED 85/30H THICKNESS
DIFFLUENCE. 03Z HRRR SIM REFL BRINGS REMNANTS OF THIS AREA INTO
NWRN CWA AFTER 08Z WITH A SECONDARY LINE MOVING INTO WRN/SWRN CWA
AROUND 15Z. NSSL WRF MAKES MORE OF A CASE FOR CONVECTION TO
MAINTAIN SOME ORGANIZATION AS IT MOVES INTO CWA AND HEADS TOWARDS
TWIN PORTS AROUND 12Z. USING PROGRESSION OF MID LVL SHEAR AXIS
PUTS HIGHEST POPS OVER ERN CWA WED AFTN. INCREASED POPS IN THIS
AREA. ALSO RAISED MAX TEMPS FROM TWIN PORTS WEST AS IT APPEARS
THAT PROGRESSION OF WESTERLY FLOW IN MIXING LAYER MAY ALLOW SOME
LATE DAY WARMING.
PREV DISCUSSION... /ISSUED 703 PM CDT TUE JUN 25 2013/
UPDATE...UPDATE TO DELAY ARRIVAL OF POPS A FEW HRS AS MAIN FOCUS
OF ACTIVITY IS OCCURRING WITHIN 85H THETAE AXIS ASSOCIATED WITH SFC
LOW/TROF OVER CENTRAL DAKOTAS. AS STATED IN PRIOR DISCUSSION
ATMOSPHERE IS QUITE UNSTABLE OVER CWA. WITH BDRY LYR DECOUPLING...SPC
MESO SHOWS AREAL COVERAGE OF SBCIN INCREASING. BOTH NSSL WRF-ARW
AND SPC WRF-NMM SIM REFLECTIVITY PRODUCTS DEPICT CURRENT
SITUATION DECENTLY REGARDING NODAK LINE OF CONVECTION. FCST
INDICATES CONSIDERABLE WEAKENING OF THE LINE AFTER IT CROSSES
NODAK/MN STATE LINE AND ENTERS WRN CWA BY 09Z. WILL MONITOR
ACTIVITY TO THE WEST THIS EVENING AND AMEND ACCORDINGLY.
PREV DISCUSSION... /ISSUED 649 PM CDT TUE JUN 25 2013/
AVIATION...00Z TAF ISSUANCE...
VFR CONDITIONS ACROSS NE MINNESOTA AND NW WISCONSIN WILL CONTINUE
THIS EVENING. BR AND/OR FG IS POSSIBLE LATE TONIGHT AND EARLY
WEDNESDAY MORNING. THE MOST LIKELY LOCATIONS FOR FG ARE KDLH AND
KHYR. STORMS IN THE NORTHERN PLAINS WILL APPROACH THE WRN CWA
AFTER MIDNIGHT. MOST LIKELY TIME FOR RW/TRW AT KINL/KBRD WOULD BE
LATE MORNING/EARLY AFTN...WITH AFTN HRS MORE LIKELY NEAR
KHIB/KDLH/KHYR. WILL TRY TO NARROW WINDOW IN NEXT FCST AT 06Z.
PREV DISCUSSION... /ISSUED 315 PM CDT TUE JUN 25 2013/
SHORT TERM...TONIGHT AND WEDNESDAY...
AT 300 PM VISIBLE SATELLITE IMAGERY
DEPICTED MOSTLY SUNNY TO PARTLY CLOUDY SKIES ACROSS THE NORTHLAND.
TEMPERATURES RANGED FROM 87 AT KHIB TO 85 AT KBRD...83 AT
KHYR...85 AT KDLH. COOLER READINGS WERE FOUND NEAR LAKE SUPERIOR
WITH 70 DEGREES AT KDYT/DULUTH HARBOR...67 LAKESIDE AT SILVER BAY
AND A CHILLY 50 DEGREES AT GRAND MARAIS.
THE FORECAST AREA WILL REMAIN SITUATED BETWEEN A H85 LOW/SFC TROUGH
APPROACHING FROM THE DAKOTAS...AND A WARM FRONT LIFTING INTO
NORTHERN WISCONSIN OVERNIGHT. ALTHOUGH INSTABILITY IS HIGH...LATEST
MODEL RUNS ARE IN AGREEMENT THAT THERE IS MUCH LESS CONVECTION
ASSOCIATED WITH THESE BOUNDARIES AS THEY PASS OVER THE REGION THROUGH
THE NEXT 24 HRS...MAINLY DUE TO THE LACK OF MID LEVEL MOISTURE.
ALTHOUGH THE FRONT IS EXPECTED TO TRIGGER SCATTERED SHOWERS AND
THUNDERSTORMS...HAVE DECREASED POPS OVERNIGHT AND WEDNESDAY FROM
PREVIOUS FORECAST DUE TO A LACK OF MID LEVEL MOISTURE TO SUPPORT
WIDESPREAD ACTIVITY. HOWEVER...THE ATMOSPHERE REMAINS VERY
UNSTABLE WITH SUFFICIENT CAPE TO SUPPORT STRONG TO POSSIBLY
SEVERE STORMS OVERNIGHT.
THE SFC BOUNDARY WILL PUSH OUT OF THE DAKOTAS LATE TONIGHT...REACH
NORTH CENTRAL MINNESOTA WEDNESDAY MORNING...THEN TRACK ACROSS THE
MINNESOTA ARROWHEAD AND NORTHERN WISCONSIN ZONES WEDNESDAY
EVENING. AS THE FRONT PASSES...EXPECT WINDS TO SWITCH OUT OF THE
NORTHWEST. GUSTS TO 20 MPH WILL BE FOUND IN THE BRAINERD LAKES
AREA...MAINLY LATE IN THE DAY. TEMPERATURES WILL TOP OUT IN THE
LOW 80S.
HAVE
PULLED BACK ON POPS TONIGHT AND WEDNESDAY TO ONLY HIGH CHANCE POPS
WITH SCATTERED WORDING. HOWEVER...NAM BUFR SOUNDINGS AND RUC
PROFILES SHOW SUFFICIENT CAPE TO SUPPORT STRONG TO POSSIBLY SEVERE
STORMS OF THE ONES THAT WILL DEVELOP.
LONG TERM [WEDNESDAY NIGHT - MONDAY]
A WEAK STATIONARY FRONT WILL STRETCH FROM THE CENTRAL CANADIAN
PROVINCES...OVER THE GREAT LAKES...AND INTO THE EASTERN UNITED
STATES DURING THE BEGINNING OF THE PERIOD. ITS PROXIMITY AND THE NW
FLOW OVER THE NORTHLAND WILL COULD HELP CAUSE PRIMARILY DAYTIME
HEATING DRIVEN SHOWERS AND THUNDERSTORMS. THE NORTH AND EASTERN
FORECAST AREA HAVE THE BEST CHANCE OF PCPN. THE STATIONARY FRONT
SHOULD THEN SWING THROUGH THE NORTHLAND LATE THIS WEEK AS A WEAK
COLD FRONT...CONTINUING THE LOW CHANCES OF SHOWERS AND THUNDERSTORMS
INTO SATURDAY EVENING. THE MODELS ARE INCREASING INDICATING THAT
HIGH PRESSURE WILL MOVE INTO THE UPPER MIDWEST EARLY NEXT WEEK AND
LIKELY PROVIDE DRY WEATHER FOR SUNDAY AND MONDAY. TEMPERATURES
SHOULD BE SLIGHTLY ABOVE NORMAL THURSDAY...NEAR NORMAL
FRIDAY...SLIGHTLY BELOW NORMAL SATURDAY...AND THEN RETURNING TO NEAR
NORMAL EARLY NEXT WEEK.
&&
.POINT TEMPS/POPS...
DLH 77 59 80 57 / 60 40 40 10
INL 81 60 79 57 / 70 50 40 20
BRD 84 63 83 60 / 40 20 10 10
HYR 80 60 83 58 / 50 40 40 20
ASX 77 56 80 57 / 60 50 30 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
AVIATION...CANNON
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1256 AM CDT WED JUN 26 2013
.UPDATE...
ISSUED AT 1255 AM CDT WED JUN 26 2013
QUICK UPDATE TO THE FORECAST TO ACCOUNT FOR LATEST RADAR TRENDS.
AREA OF SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS NORTH CENTRAL
MISSOURI WILL MOVE EAST/SOUTHEAST THE REMAINDER OF THE NIGHT
AFFECTING THE NORTHERN CWA.
ISSUED AT 953 PM CDT TUE JUN 25 2013
THUNDERSTORMS CONTINUE TO DEVELOP ACROSS IL JUST NE OF OUR
FORECAST AREA ALONG AN OLD OUTFLOW BOUNDARY. STILL EXPECTING
THUNDERSTORMS TO DEVELOP ACROSS IA AHEAD OF A WEAK SHORTWAVE AND
ON THE NOSE OF A SWLY LOW LEVEL JET...THEN GROW INTO AN MCS WHICH
SHOULD EVENTUALLY DROP SEWD INTO NERN MO AND W CNTRL IL LATE
TGT/EARLY WED MRNG. LOW TEMPERATURES TGT WILL BE QUITE MILD DUE TO
SOUTHERLY SFC WINDS AND HIGH SFC DEW POINTS.
GKS
&&
.SHORT TERM...(THROUGH LATE TONIGHT)
ISSUED AT 344 PM CDT TUE JUN 25 2013
SEVERAL THINGS TO DEAL WITH IN THE SHORT TERM TONIGHT. FIRST...STORMS
DEVELOPING IN WARM SECTOR AHEAD OF MCV THAT IS SLIDING EAST
THROUGH MO FROM MCS THAT WAS OVER WESTERN MO THIS MORNING...AS
WELL AS VARIOUS OLD OUTFLOW BOUNDARIES. THIS ACTIVITY SHOULD
DIMINISH MOST LOCATIONS BY EARLY THIS EVENING...THOUGH SOME
LINGERING ACTIVITY OVER NORTHEAST MO/WEST CENTRAL IL AS MCV SLIDES
EAST. THEN MODELS CONTINUE TO SHOW NEXT MCS DEVELOPING OVER IOWA.
FORECAST CORFIDI VECTORS HAVE THIS MCS SLIDE SOUTHEAST TOWARDS
FORECAST AREA...MAYBE EVEN MORE SOUTHERLY. SO SHOULD MOVE INTO
NORTHERN PORTIONS OF FORECAST AREA BY 06Z. LATEST HRRR RUN IS EVEN
FURTHER WEST WITH INITIAL DEVELOPMENT IN SOUTHERN IOWA...SO HAVE
RAISED POPS A BIT FURTHER WEST. THERE IS A SLIGHT RISK OF SEVERE
WEATHER...WITH THE MAIN THREATS BEING LARGE HAIL AND DAMAGING
WINDS. AS FOR TEMPS...TO REMAIN RATHER MILD WITH LOWS IN THE LOW
TO MID 70S OVERNIGHT.
BYRD
.LONG TERM...(WEDNESDAY THROUGH NEXT TUESDAY)
ISSUED AT 344 PM CDT TUE JUN 25 2013
COMPLEX SCENARIO ON TAP FOR WEDNESDAY WITH LOTS OF UNCERTAINTY TO
SPECIFIC FORECAST DETAILS. THE MAIN COMPLICATING FACTOR IS THE
OVERNIGHT MCS EXPECTED TO IMPACT WESTERN IL AND PORTIONS OF ERN MO
AND WHERE IT WILL BE LOCATED AT DAYBREAK. A CONSENSUS OF MODEL
SOLUTIONS HAVE THE DECAYING MCS IN CENTERED THRU IL AT DAYBREAK WITH
THE TRAILING FLANK OR BOUNDARY LOCATED ALONG THE MS RIVER IN ERN MO.
THE VEERED NATURE OF THE TROPOSPHERIC WINDS AND WLY LLJ WOULD
SUGGEST THIS SYSTEM SHOULD CONTINUE TO MOVE SEWD IN A DECAYING STATE
THROUGH THE MORNING WITH POTENTIAL FOR SOME STORMS ON THE TRAILING
BOUNDARY. STRONG HEATING SHOULD COMMENCE DURING THE DAY WITHIN THE
WARM SECTOR AHEAD OF THE ENCROACHING COLD FRONT...AS WELL AS WEST
OR SOUTHWEST OF ANY REMNANT BOUNDARIES. THE HEATING WILL BE MORE
LIMITED WITH EASTWARD EXTENT DUE TO RESIDUAL CLOUDINESS FROM THE
MORNING...BUT THE WARM SECTOR IS EXPECTED TO BECOME VERY UNSTABLE
AND WEAKLY CAPPED WITH SBCAPE AOA 4000 J/KG. SCATTERED THUNDERSTORMS
ARE EXPECTED TO REDEVELOP IN THE AFTERNOON WITHIN THE CONFLUENT ZONE
AHEAD OF THE COLD FRONT AND WITH ANY RESIDUAL BOUNDARIES...PRIMARILY
FROM EAST CENTRAL/SE MO INTO SOUTH CENTRAL AND SW IL. DEEP LAYER
SHEAR OF 30-40 KTS AND THE AMOUNT OF INSTABILITY WOULD FAVOR
SUPERCELL AND MULTICELL MODES. THE MORNING CONVECTION AND/OR
RESIDUAL CLOUDS PRESENT SOME PROBLEMS WITH RESPECT TO THE
MAGNITUDE OF HEAT. I HAVE COOLED TEMPS SLIGHTLY FROM ST LOUIS
EASTWARD AND THIS IS HIGHLY DEPENDENT ON MORNING CLOUDS. GIVEN THE
UNCERTAINTIES I HAVE DEFER ED ON ANY HEAT ADVISORIES WITH HEAT
INDICES FORECAST IN THE 100-105 RANGE. STORMS SHOULD BE CLOSE TO
EXITING THE CWA OR WILL HAVE EXITED THE CWA BY 00Z THURSDAY.
EVEN IN THE WAKE OF THE INITIAL COLD FRONT/BOUNDARY...THURSDAY LOOKS
LIKE ANOTHER SEASONABLY HOT DAY. IN FACT...IT IS NOT TOTALLY OUT OF
THE QUESTION IT COULD BE HOTTER THAN WEDNESDAY BUT WITH LESSER
HUMIDITY. THE ANTICIPATED NORTHWEST FLOW SHORTWAVE AND SECONDARY
COLD FRONT WILL MOVE THROUGH THE AREA LATE THURSDAY NIGHT INTO EARLY
FRIDAY WITH A PROMINENT WSW LLJ AHEAD OF IT. THIS SHOULD FUEL
ANOTHER MCS WHICH WILL IMPACT PORTIONS OF THE CWA. THE MODELS
DIVERGE ON THE MCS TRACK WITH THE GREATEST PROBABILITY ATTM
APPEARING TO BE THROUGH CENTRAL MO. MUCH COOLER AIR WILL THEN
SPREAD INTO THE AREA IN THE WAKE OF THE FRONT FOR FRIDAY AND SET
THE STAGE FOR A PROLONGED PERIOD OF BELOW AVERAGE TEMPERATURES
INTO THE EXTENDED RANGES.
THE EXTENDED RANGES WILL FEATURE AN AMPLIFIED BLOCKY UPPER AIR REGIME
FROM THE ERN PACIFIC ACROSS THE CONUS INTO THE WRN ATLANTIC...WITH A
STRONG UPPER HIGH/RIDGE CENTERED IN THE WRN U.S. AND DEEP TROF IN
THE ERN U.S. A SERIES OF SHORT WAVES WILL DROP SSEWD DOWN THE
BACKSIDE OF THE UPPER TROF AND IMPACT THE AREA ON SUNDAY AND TUESDAY
REINFORCING THE "COOLER" AIR AND BRINGING A CHANCE OF SHOWERS AND
THUNDERSTORMS.
GLASS
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1147 PM CDT TUE JUN 25 2013
THUNDERSTORMS HAVE BEGUN TO DEVELOP OVER NORTHWEST MISSOURI AND
HAVE SHOWN SOME EASTWARD MOVEMENT. CURRENT MOTION WOULD PLACE IT
AT KUIN AROUND 10Z. CURRENTLY EXPECT THESE STORMS TO STAY NORTH
OF KCOU...THOUGH WILL NEED TO MONITOR TO SEE IT DEVELOPMENT IS
FARTHER SOUTH THAN EXPECTED. THESE STORMS COULD ALSO AFFECT THE
ST. LOUIS METRO TAFS...WITH STORMS REMAINING IN THE AREA INTO
WEDNESDAY AFTERNOON. STORMS THROUGH SUNRISE COULD POSE A THREAT OF
GUSTY WINDS...SMALL HAIL AND MVFR/IFR CONDITIONS. STRONGER THREAT
FOR SEVERE THUNDERSTORMS WILL OCCUR ON WEDNESDAY AFTERNOON AS
STORMS REGENERATE MAINLY SOUTH AND EAST OF THE ST. LOUIS METRO
AREA.
SPECIFICS FOR KSTL...THERE CONTINUES TO BE A THREAT FOR
THUNDERSTORMS TOWARD SUNRISE THAT WILL CONTINUE INTO EARLY
AFTERNOON. TIMING IS STILL UNCERTAIN...SO WILL KEEP VCTS FOR NOW.
OTHERWISE EXPECT MAINLY DRY AND VFR CONDITIONS.
BRITT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1206 AM CDT Wed Jun 26 2013
.UPDATE...
Issued at 1014 PM CDT TUE JUN 25 2013
Models continue to have difficulty grasping onto how convection will
unfold tonight. If 00z NAM and latest HRRR were on track we`d already
have an a convective complex forming over eastern NE and northeast
KS. However the latest radar and satellite data shows only a few
isolated cells over eastern NE. With the h7 shortwave axis, per SPC
analysis, now along the NE/IA state line trailing into central KS
focus for a convective complex is shifted eastward into central IA
where a considerable accas field is noted. HRRR and NAM both
eventually latch onto this area over the next few hours and spread
convection into northeast MO. Given the extensive accas field and
some new cells popping up over central IA will highlight northeast MO
with highest PoPs overnight.
&&
.SHORT TERM...(This Evening through Wednesday)
Issued at 405 PM CDT TUE JUN 25 2013
Convection across eastern Kansas, which kept our morning
temperatures rather pleasant thanks to the cloud cover, finally
dissipated in the early afternoon, allowing the sun to get to work
heating things up. As the cloud cover has moved off, readings have
begun jumping quickly towards the low 90s. The atmospheric
conditions that will prevail over the next couple of days will be
quite similar to today, only without the cooling effect from morning
convection.
Stormy activity later tonight is expected to get going in eastern
Nebraska and Iowa late tonight on the nose of a nocturnal jet.
Currently, expectations are that the hot and dry air that is
advecting in today -- 700mb temperatures > 13C -- will effectively
cap off much of eastern Kansas and western Missouri to any overnight
convection. Thoughts are that any activity in Iowa overnight will
likely put down a cold pool that could push some storms through north
central or northeast Missouri early Wednesday morning. However, this
activity is not expected to impact our temperatures
appreciably...though damaging winds and torrential rain will be
possible with these early morning storms.
Wednesday and into Thursday, the lack of cloud cover from storms
will allow temperatures to quickly bound into the 90s each day.
Light winds and dew point values in 60s to low 70s will result in
heat indices each day topping out around in the low 100s. In more
rural locations, this will be hot and humid but manageable, however
in the core of the Kansas City metropolitan area heat index values
will likely spike to around 105 degrees each day. As a result, in
consultation with the Kansas City MO Health Department, we are
opting to issue a heat advisory for the next two days. Currently,
the forecast for Friday indicates slightly cooler and drier
conditions, so at this time we are not expecting to need a heat
advisory beyond Thursday.
.LONG TERM...(Wednesday Night through Tuesday)
Issued at 405 PM CDT TUE JUN 25 2013
Backing 850 flow on Thursday will bring winds to the west and
southwest through the afternoon, potentially bringing temps at that
level even warmer than Weds with NAM and GFS showing 26C nudging
into western MO by afternoon. These temps would translate into
surface temps in the middle to upper 90s, while dewpoints remain
close to 70 degrees. This would yield heat indices across ern KS/wrn
MO in the 100-105 range, and being day 2 of such conditions could be
stressful especially for sensitive individuals in the KC core.
Amplifying upper ridge over the Rockies will strengthen the
northwest flow overhead on Thursday, allowing a front to drop
through the area Thursday night. This front will have an unstable
airmass to work with, but warm/dry air below 800 hPa may act against
widespread storms so kept PoPs limited to low chance category for
now.
Airmass behind the front will be relatively cooler with temperatures
returning into the lower/middle 80s by the weekend. An upper
shortwave trough will swing through the area on Sunday and could
spark a few showers or storms, but otherwise chances appear too low
to include a mention of precip through the remainder of the extended
period.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday Night)
Issued at 1205 AM CDT TUE JUN 25 2013
VFR conditions are expected through the entire forecast. Gusty south
winds will persist for a few more hours with winds shifting to the
southwest later tonight/early Wednesday morning. Winds will
eventually veer to the northwest by the afternoon as high pressure
moves over the region.
Thunderstorms have developed well northeast of the terminals and are
expected to move to the east/southeast through the night. Warm air
aloft over the terminals area will preclude any convective
development tonight. So the only areas that will see storms will be
across northern into northeastern Missouri, impacting mainly
the Kirksville and Chillicothe airspace.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...HEAT ADVISORY from 11 AM Wednesday to 7 PM CDT Thursday FOR
KSZ103>105.
MO...HEAT ADVISORY from 11 AM Wednesday to 7 PM CDT Thursday FOR
MOZ028-029-037.
&&
$$
UPDATE...MJ
SHORT TERM...Cutter
LONG TERM...Hawblitzel
AVIATION...CDB
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1154 PM CDT TUE JUN 25 2013
.UPDATE...
ISSUED AT 953 PM CDT TUE JUN 25 2013
THUNDERSTORMS CONTINUE TO DEVELOP ACROSS IL JUST NE OF OUR
FORECAST AREA ALONG AN OLD OUTFLOW BOUNDARY. STILL EXPECTING
THUNDERSTORMS TO DEVELOP ACROSS IA AHEAD OF A WEAK SHORTWAVE AND
ON THE NOSE OF A SWLY LOW LEVEL JET...THEN GROW INTO AN MCS WHICH
SHOULD EVENTUALLY DROP SEWD INTO NERN MO AND W CNTRL IL LATE
TGT/EARLY WED MRNG. LOW TEMPERATURES TGT WILL BE QUITE MILD DUE TO
SOUTHERLY SFC WINDS AND HIGH SFC DEW POINTS.
GKS
&&
.SHORT TERM...(THROUGH LATE TONIGHT)
ISSUED AT 344 PM CDT TUE JUN 25 2013
SEVERAL THINGS TO DEAL WITH IN THE SHORT TERM TONIGHT. FIRST...STORMS
DEVELOPING IN WARM SECTOR AHEAD OF MCV THAT IS SLIDING EAST
THROUGH MO FROM MCS THAT WAS OVER WESTERN MO THIS MORNING...AS
WELL AS VARIOUS OLD OUTFLOW BOUNDARIES. THIS ACTIVITY SHOULD
DIMINISH MOST LOCATIONS BY EARLY THIS EVENING...THOUGH SOME
LINGERING ACTIVITY OVER NORTHEAST MO/WEST CENTRAL IL AS MCV SLIDES
EAST. THEN MODELS CONTINUE TO SHOW NEXT MCS DEVELOPING OVER IOWA.
FORECAST CORFIDI VECTORS HAVE THIS MCS SLIDE SOUTHEAST TOWARDS
FORECAST AREA...MAYBE EVEN MORE SOUTHERLY. SO SHOULD MOVE INTO
NORTHERN PORTIONS OF FORECAST AREA BY 06Z. LATEST HRRR RUN IS EVEN
FURTHER WEST WITH INITIAL DEVELOPMENT IN SOUTHERN IOWA...SO HAVE
RAISED POPS A BIT FURTHER WEST. THERE IS A SLIGHT RISK OF SEVERE
WEATHER...WITH THE MAIN THREATS BEING LARGE HAIL AND DAMAGING
WINDS. AS FOR TEMPS...TO REMAIN RATHER MILD WITH LOWS IN THE LOW
TO MID 70S OVERNIGHT.
BYRD
.LONG TERM...(WEDNESDAY THROUGH NEXT TUESDAY)
ISSUED AT 344 PM CDT TUE JUN 25 2013
COMPLEX SCENARIO ON TAP FOR WEDNESDAY WITH LOTS OF UNCERTAINTY TO
SPECIFIC FORECAST DETAILS. THE MAIN COMPLICATING FACTOR IS THE
OVERNIGHT MCS EXPECTED TO IMPACT WESTERN IL AND PORTIONS OF ERN MO
AND WHERE IT WILL BE LOCATED AT DAYBREAK. A CONSENSUS OF MODEL
SOLUTIONS HAVE THE DECAYING MCS IN CENTERED THRU IL AT DAYBREAK WITH
THE TRAILING FLANK OR BOUNDARY LOCATED ALONG THE MS RIVER IN ERN MO.
THE VEERED NATURE OF THE TROPOSPHERIC WINDS AND WLY LLJ WOULD
SUGGEST THIS SYSTEM SHOULD CONTINUE TO MOVE SEWD IN A DECAYING STATE
THROUGH THE MORNING WITH POTENTIAL FOR SOME STORMS ON THE TRAILING
BOUNDARY. STRONG HEATING SHOULD COMMENCE DURING THE DAY WITHIN THE
WARM SECTOR AHEAD OF THE ENCROACHING COLD FRONT...AS WELL AS WEST
OR SOUTHWEST OF ANY REMNANT BOUNDARIES. THE HEATING WILL BE MORE
LIMITED WITH EASTWARD EXTENT DUE TO RESIDUAL CLOUDINESS FROM THE
MORNING...BUT THE WARM SECTOR IS EXPECTED TO BECOME VERY UNSTABLE
AND WEAKLY CAPPED WITH SBCAPE AOA 4000 J/KG. SCATTERED THUNDERSTORMS
ARE EXPECTED TO REDEVELOP IN THE AFTERNOON WITHIN THE CONFLUENT ZONE
AHEAD OF THE COLD FRONT AND WITH ANY RESIDUAL BOUNDARIES...PRIMARILY
FROM EAST CENTRAL/SE MO INTO SOUTH CENTRAL AND SW IL. DEEP LAYER
SHEAR OF 30-40 KTS AND THE AMOUNT OF INSTABILITY WOULD FAVOR
SUPERCELL AND MULTICELL MODES. THE MORNING CONVECTION AND/OR
RESIDUAL CLOUDS PRESENT SOME PROBLEMS WITH RESPECT TO THE
MAGNITUDE OF HEAT. I HAVE COOLED TEMPS SLIGHTLY FROM ST LOUIS
EASTWARD AND THIS IS HIGHLY DEPENDENT ON MORNING CLOUDS. GIVEN THE
UNCERTAINTIES I HAVE DEFER ED ON ANY HEAT ADVISORIES WITH HEAT
INDICES FORECAST IN THE 100-105 RANGE. STORMS SHOULD BE CLOSE TO
EXITING THE CWA OR WILL HAVE EXITED THE CWA BY 00Z THURSDAY.
EVEN IN THE WAKE OF THE INITIAL COLD FRONT/BOUNDARY...THURSDAY LOOKS
LIKE ANOTHER SEASONABLY HOT DAY. IN FACT...IT IS NOT TOTALLY OUT OF
THE QUESTION IT COULD BE HOTTER THAN WEDNESDAY BUT WITH LESSER
HUMIDITY. THE ANTICIPATED NORTHWEST FLOW SHORTWAVE AND SECONDARY
COLD FRONT WILL MOVE THROUGH THE AREA LATE THURSDAY NIGHT INTO EARLY
FRIDAY WITH A PROMINENT WSW LLJ AHEAD OF IT. THIS SHOULD FUEL
ANOTHER MCS WHICH WILL IMPACT PORTIONS OF THE CWA. THE MODELS
DIVERGE ON THE MCS TRACK WITH THE GREATEST PROBABILITY ATTM
APPEARING TO BE THROUGH CENTRAL MO. MUCH COOLER AIR WILL THEN
SPREAD INTO THE AREA IN THE WAKE OF THE FRONT FOR FRIDAY AND SET
THE STAGE FOR A PROLONGED PERIOD OF BELOW AVERAGE TEMPERATURES
INTO THE EXTENDED RANGES.
THE EXTENDED RANGES WILL FEATURE AN AMPLIFIED BLOCKY UPPER AIR REGIME
FROM THE ERN PACIFIC ACROSS THE CONUS INTO THE WRN ATLANTIC...WITH A
STRONG UPPER HIGH/RIDGE CENTERED IN THE WRN U.S. AND DEEP TROF IN
THE ERN U.S. A SERIES OF SHORT WAVES WILL DROP SSEWD DOWN THE
BACKSIDE OF THE UPPER TROF AND IMPACT THE AREA ON SUNDAY AND TUESDAY
REINFORCING THE "COOLER" AIR AND BRINGING A CHANCE OF SHOWERS AND
THUNDERSTORMS.
GLASS
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1147 PM CDT TUE JUN 25 2013
THUNDERSTORMS HAVE BEGUN TO DEVELOP OVER NORTHWEST MISSOURI AND
HAVE SHOWN SOME EASTWARD MOVEMENT. CURRENT MOTION WOULD PLACE IT
AT KUIN AROUND 10Z. CURRENTLY EXPECT THESE STORMS TO STAY NORTH
OF KCOU...THOUGH WILL NEED TO MONITOR TO SEE IT DEVELOPMENT IS
FARTHER SOUTH THAN EXPECTED. THESE STORMS COULD ALSO AFFECT THE
ST. LOUIS METRO TAFS...WITH STORMS REMAINING IN THE AREA INTO
WEDNESDAY AFTERNOON. STORMS THROUGH SUNRISE COULD POSE A THREAT OF
GUSTY WINDS...SMALL HAIL AND MVFR/IFR CONDITIONS. STRONGER THREAT
FOR SEVERE THUNDERSTORMS WILL OCCUR ON WEDNESDAY AFTERNOON AS
STORMS REGENERATE MAINLY SOUTH AND EAST OF THE ST. LOUIS METRO
AREA.
SPECIFICS FOR KSTL...THERE CONTINUES TO BE A THREAT FOR
THUNDERSTORMS TOWARD SUNRISE THAT WILL CONTINUE INTO EARLY
AFTERNOON. TIMING IS STILL UNCERTAIN...SO WILL KEEP VCTS FOR NOW.
OTHERWISE EXPECT MAINLY DRY AND VFR CONDITIONS.
BRITT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
157 AM EDT WED JUN 26 2013
.SYNOPSIS...
WEAK DISTURBANCES WILL CROSS THE AREA THROUGH WEDNESDAY...WITH
SCATTERED SHOWERS OR THUNDERSTORMS ANTICIPATED...BUT ALSO
SIGNIFICANT PERIODS OF RAIN-FREE WEATHER. BY THURSDAY...A STRONGER
SYSTEM WILL APPROACH...AND IS EXPECTED TO BRING MORE PERSISTENT
SHOWERS AND THUNDERSTORMS. MUGGY AND SEASONABLY WARM CONDITIONS
WILL CONTINUE...WITH HIGHS MOSTLY IN THE 80S THROUGH THE END OF
THE WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
10 UPDATE...CONV CONTS TO FIRE ACROSS CNTRL PA AHD OF A PARADE OF
WEAK SHRT WVS IN THE WLY FLOW. HRRR SEMS TO HAVE THE BEST HANDLE
ON THE CONV AND CONTS THE PCPN...WITH SLOW WEAKENING OVRNGT. WILL
CONT WITH CHANCE POPS OVER THE SRN ZONES AND SLGT CHANCE ELSEWHERE
FOR ROGUE SHWRS FIRING FURTHER NORTH. PLENTY OF CLDS UPSTREAM AS
WELL SO FOG SHD NOT BE A BIG CNCRN OVERNGT. PRVS DISC BLO.
345 PM UPDATE... ONE BATCH OF CONVECTION IS EXITING OUR ERN ZNS
LATE THIS AFTN...ASSOCD WITH A DEPARTING MCV. CNY/NE PA SHOULD
EXPERIENCE A RELATIVE LULL/RAIN-FREE PD THROUGH 22-00Z.
BY EARLY EVE...AN ORGANIZING BAND OF SHRA/TSRA...FROM SRN ONT ACRS
LK ERIE AND ERN OH ATTM...IS EXPECTED TO COME EWD...AND COULD WELL
IMPACT SRN PTNS OF THE FA. THERE IS SOME UNCERTAINTY REGARDING LINGERING
AMTS OF INSTAB BY THIS TIME...BUT IT WILL LIKELY STILL BE
UNSTABLE ENOUGH FOR AT LEAST SCTD COVERAGE. GIVEN INCREASED VERT
SHEAR THIS EVE (0-3 KM VALUES NEAR 40 KT)...STORMS WILL HAVE TO BE
WATCHED FOR WIND POTENTIAL...SHOULD THEY ORGANIZE INTO LINEAR
FEATURES.
LTR TNT...WE SHOULD SEE A SHORT BREAK IN PCPN ONCE AGN. SINCE
THERE IS PLENTY OF CLOUD DEBRIS UPSTREAM TO THE W ATTM...WE
ANTICIPATE PTLY TO MOSTLY CLDY SKIES MUCH OF THE NGT...AND THIS
CLOUD COVER SHOULD CUT DOWN ON THE RADIATIONAL COOLING/FOG
POTENTIAL.
TWDS DAYBREAK...ANOTHER INCOMING UPR-LVL WAVE COULD BRING A ROUND
OF SHWRS...AND WE`VE THUS BROUGHT CHC/SCTD POPS IN FROM THE W
AFTER 08-09Z.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
4 PM UPDATE... AN UPR-LVL WAVE WILL CROSS NY/PA WED...MAINLY IN
THE AM HRS (BEFORE 18Z). SUCH EARLY TIMING WOULD SUGGEST NON-SVR
STORMS...WITH PERHAPS INSUFFICIENT TIME FOR ADEQUATE
DESTABILIZATION...BEFORE THE WV BEGINS TO DEPART...WITH
DIMINISHING ACTIVITY IN THE AFTN. FOR NOW...WE GRADUALLY TAPER
CHC/SCTD POPS BACK...FROM NW TO SE...AFTER 18Z.
THE NEXT STGR UPR-LVL SYSTEM IS PROGGED TO DIG INTO THE ERN LKS/OH
VLY RGN LATE WED NGT/THU. AT THIS EARLY JUNCTURE...MOST OF WED NGT
SHOULD FEATURE EITHER NO PCPN...OR JUST HIT AND MISS SHWR ACTIVITY.
HOWEVER...LATE AT NGT INTO THU AM...OUR CHCS FOR SHWRS/THUNDER
SHOULD INCREASE...AS UPR-LVL JET FORCING AND MOISTURE ADVECTION
IMPROVE.
THERE REMAIN SUBTLE MODEL POSITIONING DIFFS ON THU...BUT THE
MAIN SYNOPTIC IDEA IS FOR A FAIRLY AMPLIFIED UPR-LVL WAVE TO
SLOWLY LIFT FROM THE OH VLY INTO THE NERN STATES...WITH A PRETTY
WELL DEFINED SFC LOW FOR THIS TIME OF YEAR...TRANSLATING NEWD
ACRS PA AND NY STATE. THUS...WE`VE BUMPED POPS INTO THE LIKELY/NUMEROUS
RANGES. DEPENDING ON SPECIFICALLY WHERE THE SFC LOW TRACKS...THE
WARM SECTOR DVLPS...AND THE EXTENT OF CLOUD COVER/SFC
HEATING...THERE IS POTENTIAL FOR SVR STORMS (GOOD LOW-LVL DIR
SHEAR AND VERT SPEED SHEAR). WE`LL SIMPLY HAVE TO SEE HOW THINGS
EVOLVE OVER THE NEXT COUPLE OF DAYS. FOR NOW...WE`LL CONTINUE TO
HIGHLIGHT THIS POTENTIAL IN THE HWO.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
VERY FEW CHANGES MADE TO THE EXTENDED TIME FRAME WITH THE
EXCEPTION OF INCREASING POPS INTO THE LIKELY CATEGORY THIS WEEKEND
INTO EARLY NEXT WEEK AS MODEL TRENDS CONTINUE TO FAVOR A VERY WET
SCENARIO IN COMING DAYS. MAIN CULPRITS CONTINUE TO BE DEVELOPING
RIDGING ACROSS BOTH THE NORTHERN ATLANTIC AND INTERMOUNTAIN
WEST...WITH ALL MODELS ALSO SHOWING A DIGGING UPPER-LEVEL TROUGH
EXTENDING FROM THE CENTRAL GREAT LAKES SOUTH INTO THE LWR MISS RVR
VLY. CONCERNS CONTINUE TO INCREASE THAT TROPICAL CONNECTIONS WILL
BECOME FIRMLY ESTABLISHED BY THE WEEKEND AS THE GULF OF MEXICO AND
WESTERN ATLANTIC REMAIN WIDE-OPEN FOR STRONG LOW-LEVEL MOISTURE
TRANSPORT NORTH ALONG THE ATLANTIC SEABOARD. AS A RESULT...FELT
COMPELLED TO INCREASE POPS ACCORDINGLY...WHICH AGREES WELL WITH
LATEST 12Z WPC GUIDANCE. TRENDS WILL HAVE TO BE MONITORED IN
COMING DAYS...BUT THE DEVELOPING SYNOPTIC PATTERN LOOKS EERILY
SIMILAR TO PATTERNS RESPONSIBLE FOR PAST LARGE-SCALE EAST COAST
FLOOD EVENTS. STAY TUNED!
&&
.AVIATION /06Z WEDNESDAY THROUGH THURSDAY NIGHT/...
200 AM EDT UPDATE...
A FEW ISOLATED SHOWERS ARE LINGERING ACROSS CENTRAL NY EARLY
THIS MORNING. THIS ACTIVITY WILL SLOWLY DIMINISH OVER THE NEXT FEW
HOURS. LOW LEVEL MOISTURE WILL CREEP INTO CENTRAL NY THIS MORNING
FROM THE WEST AND WITH THE SHOWERS DIMINISHING... A LOW STRATUS
DECK NEAR 2500 FT MAY FORM ACROSS THE REGION AND LAST FOR A FEW
HOURS. ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS
THE AREA WEDNESDAY MORNING/AFTERNOON. THIS ACTIVITY WILL DISRUPT
THE STRATUS DECK AND VFR CONDITIONS WILL RETURN WITH MVFR
VISIBILITIES. THIS ROUND OF STORMS WILL PUSH THROUGH THE REGION BY
LATE AFTERNOON AND VFR CLOUD DECKS WILL LINGER IN THE PASSING OF THE
SYSTEM.
OUTLOOK...FRI THROUGH SUN...
FRI...MAINLY VFR. EARLY MORNING MVFR/IFR IN VALLEY FOG.
SAT...MVFR RESTRICTIONS POSSIBLE IN DEVELOPING RA.
SUN...MVFR POSSIBLE IN SHOWERS/STORMS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DGM/MLJ
NEAR TERM...DGM/MLJ
SHORT TERM...MLJ
LONG TERM...CMG
AVIATION...KAH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1223 AM CDT WED JUN 26 2013
.UPDATE...
ISSUED AT 1223 AM CDT WED JUN 26 2013
UPDATE FOR THE EXPIRATION OF SEVERE THUNDERSTORM WATCH 364 ACROSS
THE JAMES RIVER VALLEY. REMAINING STORMS ACROSS DICKEY AND LAMOURE
COUNTIES ARE EXPECTED TO CLEAR THE CWA BY 06 UTC AND REMAIN BELOW
SEVERE LIMITS GIVEN WEAK DEEP LAYER SHEAR. WILL CONTINUE TO
MONITOR RAINFALL WITH THESE STORMS. HOWEVER...THEY HAVE BEEN
PROPAGATING TO THE EAST AT 20 KTS...LIMITING THE FLASH FLOOD
THREAT.
UPDATE ISSUED AT 1047 PM CDT TUE JUN 25 2013
SEVERE THUNDERSTORM WATCH HAS BEEN CANCELLED FOR ALL BUT FOSTER...
STUTSMAN...DICKEY AND LAMOURE COUNTIES. HAVE ONCE AGAIN UPDATED
FOR LATEST RADAR TRENDS...REMOVING ALL POPS BUT FOR THE REMAINING
COUNTIES IN THE SEVERE THUNDERSTORM WATCH. THIS ACTIVITY SHOULD BE
OUT OF THE CWA AROUND MIDNIGHT. WILL ALSO CANCEL THE REMAINING
COUNTIES OF THE FLASH FLOOD WATCH SHORTLY.
UPDATE ISSUED AT 849 PM CDT TUE JUN 25 2013
HAVE REMOVED ANOTHER TIER OF COUNTIES FROM THE SEVERE THUNDERSTORM
AND FLASH FLOOD WATCHES. ALSO ADJUSTED POPS BASED ON CURRENT RADAR.
OTHERWISE NO SIGNIFICANT CHANGES TO THE GOING FORECAST. UPDATED
FLASH FLOOD WATCH AND WCN PRODUCTS HAVE BEEN SENT. REMAINING
UPDATED PRODUCTS OUT SHORTLY.
UPDATE ISSUED AT 708 PM CDT TUE JUN 25 2013
CONVECTION ACROSS CENTRAL NORTH DAKOTA CONTINUES TO MOVE
NORTHEAST. WIND SHIFT HAS MOVED THROUGH NORTHWEST...INTO THE SOUTH
CENTRAL PORTION OF THE STATE. THUS HAVE DROPPED WESTERN PORTIONS
OF THE SEVERE THUNDERSTORM WATCH INCLUDING MORTON...MERCER...
OLIVER...DIVIDE AND WILLIAMS. HAVE ALSO DROPPED WESTERN PORTIONS
OF THE FLASH FLOOD WATCH. THESE UPDATES HAVE BEEN SENT.
MAIN UPDATES WERE TO ADJUST POPS TO CURRENT RADAR TRENDS. UPDATED
ZONES AND STATE WILL BE SENT SHORTLY.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 200 PM CDT TUE JUN 25 2013
FORECAST HIGHLIGHTS IN THE SHORT TERM FORECAST PERIOD WILL BE
STRONG TO SEVERE THUNDERSTORMS AND HEAVY RAIN POTENTIAL THROUGH
THIS EVENING.
CURRENTLY...WARM AND VERY HUMID DAY WITH DAYTIME HIGHS IN THE 80S
AND SURFACE DEWPOINT TEMPS FROM 60 TO THE LOW 70S. LATEST RADAR IS
VOID OF ECHOS OVER WEST AND CENTRAL NORTH DAKOTA AS OF 2 PM CDT.
LATEST MODEL GUIDANCE SUGGESTS CONVECTIVE DEVELOPMENT
NORTHWEST/NORTH CENTRAL EARLY THIS AFTERNOON...BUILDING SOUTH-
SOUTHEAST LATE AFTERNOON-EARLY EVENING ALONG A SURFACE TROUGH IN
PLACE FROM NORTHWEST NORTH DAKOTA THROUGH CENTRAL SOUTH DAKOTA.
17-18Z RAP SOUNDINGS WEAKEN/ERASE THE CAP BETWEEN 20-22Z ALONG THE
SFC TROUGH AXIS. TRIGGER WILL BE A STRONG MID LEVEL S/WV PUSHING
INTO WESTERN NORTH DAKOTA NOW...HELPING TO WEAKEN THE STRONG
CAPPING INVERSION CURRENTLY IN PLACE. CONVECTION SHOULD THEN PUSH
EAST THIS EVENING INTO THE OVERNIGHT WITH THE MID LEVEL WAVE AND
SFC TROUGH. STRONG TO SEVERE WEATHER REMAINS IN PLAY WITH THE VERY
STRONG INSTABILITY PRESENT...CURRENTLY 3-6K J/KG. LIMITING FACTOR
WILL BE RATHER WEAK 0-6KM/EFFECTIVE SHEAR UP TO AROUND 20KTS
CURRENTLY IN PLACE AND FORECAST THROUGH THIS EVENING. STILL...WITH
THE AMOUNT OF CAPE PRESENT THERE IS A GOOD PROBABILITY OF LARGE
SEVERE HAIL AND A DAMAGING WIND GUSTS. STORMS WILL BE WATER
LOADED SO WILL LIKELY NEED A RATHER ROBUST/TALL UPDRAFT TO GET THE
LARGE HAIL. IT DOES APPEAR THE MAIN THREAT TODAY INTO THIS EVENING
WILL BE VERY HEAVY RAINFALL ELEVATING THE THREAT FOR FLASH
FLOODING.
CONVECTIVE CHANCES WILL END FROM WEST TO EAST THIS EVENING THROUGH
WEDNESDAY MORNING AS FORCING PUSHES EASTWARD.
OPTED TO KEEP WEDNESDAY AFTERNOON DRY FOR NOW ALONG WITH THE 12Z
GFS/00Z ECMWF. THE 06Z AND 12Z NAM BOTH PAINTED LIGHT DIURNALLY
DRIVEN QPF...SO WILL LET LATER SHIFTS TAKE A LOOK WITH ATTENTION
FOCUSED ON THE NEXT 12 HOURS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 200 PM CDT TUE JUN 25 2013
THE MAIN FEATURE FOR THE EXTENDED PERIOD WILL BE THE INTENSIFYING
UPPER LEVEL RIDGE OVER THE WESTERN US/CANADA AS FORECAST BY THE 12Z
MODEL SUITE. WITH THE RIDGE AXIS POSITIONED OVER THE INTERMOUNTAIN
WEST...NORTH TO NORTHWESTERLY FLOW WILL BE DOMINANT ACROSS NORTH
DAKOTA FOR MUCH OF THE PERIOD. THIS WILL ALLOW FOR SEASONABLE
TEMPERATURES...IN THE 80S TO CONTINUE...KEEPING THE AREA OUT THE
WARMEST H850 TEMPERATURES THAT WILL DEVELOP ACROSS THE WESTERN US.
OVERALL THE FORECAST WILL REMAIN DRY...HOWEVER THERE WILL BE
PERIODIC CHANCES FOR PRECIPITATION FOR PARTS OF CENTRAL AND EASTERN
NORTH DAKOTA...AS A FEW SHORTWAVES ROTATE AROUND THE WESTERN
PERIPHERY OF THE UPPER LEVEL LOW POSITIONED OVER THE GREAT LAKES
REGION. LATE THIS WEEKEND/EARLY NEXT WEEK...SOME UNCERTAINTY IS
INTRODUCED INTO THE FORECAST AS THE THERE IS SOME DISAGREEMENT
AMONGST THE 12Z LONG RANGE MODELS REGARDING THE POTENT SHORTWAVE
THAT IS PROGGED TO DROP SOUTH FROM CANADA AND INTO THE NORTHERN
PLAINS. DUE TO THIS UNCERTAINTY...WILL MAKE NO CHANGES TO THE
ALLBLEND SOLUTION AT THIS TIME SINCE THERE IS NO TARGET OF
OPPORTUNITY TO IMPROVE FORECAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1223 AM CDT WED JUN 26 2013
VFR CONDITIONS ARE EXPECTED AT ALL TERMINALS FOR THE 06 UTC TAF
CYCLE SOUTH OF WEAK LOW PRESSURE ACROSS SOUTHERN CANADA.
&&
.HYDROLOGY...
ISSUED AT 200 PM CDT TUE JUN 25 2013
A FLASH FLOOD WATCH REMAINS IN EFFECT FOR NORTHWEST AND CENTRAL
NORTH DAKOTA THROUGH THIS EVENING. VERY SLOW MOVING THUNDERSTORMS
WITH INTENSE RAINFALL RATES ARE EXPECTED. ONE HOUR FLASH FLOOD
GUIDANCE IS AROUND ONE TO ONE AND A HALF INCHES ACROSS MOST OF THE
WATCH AREA. RAINFALL RATES WITH THUNDERSTORMS TODAY WILL EASILY
SURPASS THIS THRESHOLD...AND WILL HAVE TO CLOSELY MONITOR FOR
FLASH FLOODING THIS AFTERNOON AND EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
LONG TERM...LTH
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
840 AM PDT WED JUN 26 2013
...MUCH WARMER WEATHER ON THE WAY...
.DISCUSSION...AS OF 08:40 AM PDT WEDNESDAY...HUMID AIR PERSISTS
OVER THE REGION WITH DEWPOINTS IN THE SIXTIES THIS MORNING. A
THIN LAYER OF PATCHY FOG IS AFFECTING PORTIONS OF THE COAST AND
NORTH BAY WITH VISIBILITIES AS LOW AS A QUARTER MILE IN SPOTS.
EXPECT FOG TO BURN OFF BY MID MORNING AND DAYTIME HIGHS TO RUN
FIVE TO TEN DEGREES ABOVE YESTERDAY. MODEL OUTPUT SO FAR THIS
MORNING CONTINUES TO INDICATE PROLONGED WARMING TREND. FORECAST ON
TRACK AND NO UPDATES NECESSARY AT THIS TIME.
&&
.PREV DISCUSSION...AS OF 3:00 AM PDT WEDNESDAY...OVERNIGHT RAIN
ENDED ACROSS OUR CWA AFTER DROPPING A WIDE RANGE OF AMOUNTS FOR
SUNDAY NIGHT TO TUESDAY NIGHT. VALUES RANGED FROM LESS THAN A
TENTH FOR MOST OF THE SOUTHERN CWA ALL OF THE WAY UP TO OVER 5
INCHES FOR SPOTS IN THE NORTH BAY. STILL PLENTY OF MOIST AIR IN
PLACE WHICH IS HELPING TO KEEP DEW POINTS AT HIGH LEVELS EARLY
THIS MORNING ALONG WITH SOME PATCHY FOG NOW BEING INDICATED BY THE
SATELLITE FOG PRODUCT. SURFACE OBS ARE ALSO STARING TO INDICATE A
FEW POCKETS OF REDUCED VISIBILITIES AND THIS SHOULD CONTINUE TO
INCREASE THROUGH THE FIRST HALF OF THE MORNING.
MAIN STORY FOR THE REST OF THE WEEK THROUGH MOST OF NEXT WEEK WILL BE
THE MUCH WARMER WEATHER THAT WILL RETURN TO THE ENTIRE REGION AS A
RIDGE OF HIGH PRESSURE BUILDS TO MUCH OF THE WEST. CONFIDENCE IS
VERY HIGH THAT VERY WARM TO HOT WEATHER WILL RETURN TO INLAND
SPOTS AS 850 MB TEMPS RISE TO AROUND 30C WHILE 500 MB HEIGHT GET
CLOSE TO 600 DM (MOST LIKELY 596-598 DM AROUND HERE). BOTH OF
THESE VALUES ALONG WITH THE GENERAL PATTERN SUGGEST SOME HIGHS
(PLUS EVEN A FEW OVERNIGHT LOWS) WILL APPROACH RECORD VALUES. WHAT
IS NOT ENTIRE CLEAR IS IF WE ARE LOOKING AT A WIDESPREAD HEAT
WARNING EVENT OR JUST VERY WARM READINGS. WHAT IS INTERESTING TO
NOTE IS THE NEW ECMWF HAS 850 MB TEMPS CLOSET TO 28-30C WHILE THE
GFS IS NOW MORE IN THE 30-32C RANGE. CLOSER TO THE COAST...THERE
IS UNCERTAINTY IF THE HEAT WILL PUSH ALL OF THE WAY TO THE OCEAN
OR IF THE THERMAL TROUGH WILL NOT BE ABLE TO MAKE IT THAT FAR.
ALSO WORTH POINTING OUT THAT THE TEMPERATURE ANOMALIES ARE ONLY
EXPECTED TO BE 2 TO 3 ABOVE NORMAL -- STILL IMPRESSIVE, HOWEVER
SHORT OF NUMBERS THAT WE LIKE TO SEE FOR A MAJOR EVENT.
OVERNIGHT LOWS WILL ALSO BE OF NOTE FROM THE EVENT WITH MANY
HIGHER ELEVATION LOCATIONS STRUGGLING TO COOL OUT OF THE 70S (SOME
SPOTS MAY STAY IN THE LOWER 80S AT NIGHT). MANY URBAN SPOTS WILL
LIKELY STAY IN THE 60S. AFTER LOOKING AT THE VARIOUS SOLUTIONS,
DECIDED TO BOOST SOME OF THE HIGHS (ESPECIALLY NEAR THE COAST) AND
LOWS FOR HIGHER ELEVATION SPOTS PLUS PARTS OF THE SANTA CLARA
VALLEY.
CPC KEEPS THE WARMER THAN NORMAL WEATHER CONTINUING OUT FOR THE
6-10 AND 8-14 DAY PERIODS WITH AN ABOVE NORMAL CONFIDENCE LEVEL.
THAT WOULD TAKE US OUT TO JULY 9TH.
&&
.AVIATION...AS OF 4:35 AM PDT WEDNESDAY...UPPER LEVEL HIGH
PRESSURE WILL CONTINUE TO BUILD OVER THE REGION THROUGH THE
FORECAST. ABUNDANT STRATUS OFFSHORE AND HIGH SURFACE MOISTURE (DUE
TO THE RAIN SHOWERS OVER THE PAST FEW DAYS) WILL MAKE FOR A
DIFFICULT FORECAST THROUGH AT LEAST THE EARLY AFTERNOON HOURS.
POSSIBLE REDUCED VISIBILITIES MAY IMPACT THE TERMINALS THROUGH THE
EARLY MORNING HOURS. OTHERWISE...MODERATE WEST WINDS WILL BE
PRESENT ACROSS THE AREA THIS AFTERNOON THROUGH THE EARLY EVENING
HOURS.
VICINITY OF KSFO...POSSIBLE IFR CIGS THROUGH 16Z. VERY LOW
CONFIDENCE. VFR CONDITIONS WILL BE POSSIBLE AFTER
19Z...HOWEVER...A FEW OF THE SHORT TERM MODELS INDICATE CLEARING A
FEW HOURS LATER...CLOSER TO 21Z. MODERATE ONSHORE TO 15 KT THIS
AFTERNOON.
KSFO BRIDGE APPROACH...PATCHY LOW CLOUDS MAY IMPACT THE APPROACH
AN HOUR LATER THAN THE TERMINAL. LOW CONFIDENCE.
MONTEREY BAY AREA TERMINALS...POSSIBLE VLIFR CIGS AND VIS POSSIBLE
THROUGH THE EARLY MORNING HOURS. THE HRRR AND LOCAL WRF INDICATE
THAT KMRY COULD SEE LOW CLOUDS ALL DAY...ADDING TO THE UNCERTAINTY
OF THE FORECAST. OTHERWISE...MODERATE ONSHORE THIS AFTERNOON WITH
AN EARLY RETURN OF STRATUS THIS EVENING.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
$$
PUBLIC FORECAST: AC/BELL
AVIATION/MARINE: RILEY
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
439 AM PDT WED JUN 26 2013
...MUCH WARMER WEATHER ON THE WAY...
.DISCUSSION...AS OF 3:00 AM PDT WEDNESDAY...OVERNIGHT RAIN ENDED
ACROSS OUR CWA AFTER DROPPING A WIDE RANGE OF AMOUNTS FOR SUNDAY
NIGHT TO TUESDAY NIGHT. VALUES RANGED FROM LESS THAN A TENTH FOR
MOST OF THE SOUTHERN CWA ALL OF THE WAY UP TO OVER 5 INCHES FOR
SPOTS IN THE NORTH BAY. STILL PLENTY OF MOIST AIR IN PLACE WHICH
IS HELPING TO KEEP DEW POINTS AT HIGH LEVELS EARLY THIS MORNING
ALONG WITH SOME PATCHY FOG NOW BEING INDICATED BY THE SATELLITE
FOG PRODUCT. SURFACE OBS ARE ALSO STARING TO INDICATE A FEW
POCKETS OF REDUCED VISIBILITIES AND THIS SHOULD CONTINUE TO
INCREASE THROUGH THE FIRST HALF OF THE MORNING.
MAIN STORY FOR THE REST OF THE WEEK THROUGH MOST OF NEXT WEEK WILL BE
THE MUCH WARMER WEATHER THAT WILL RETURN TO THE ENTIRE REGION AS A
RIDGE OF HIGH PRESSURE BUILDS TO MUCH OF THE WEST. CONFIDENCE IS
VERY HIGH THAT VERY WARM TO HOT WEATHER WILL RETURN TO INLAND
SPOTS AS 850 MB TEMPS RISE TO AROUND 30C WHILE 500 MB HEIGHT GET
CLOSE TO 600 DM (MOST LIKELY 596-598 DM AROUND HERE). BOTH OF
THESE VALUES ALONG WITH THE GENERAL PATTERN SUGGEST SOME HIGHS
(PLUS EVEN A FEW OVERNIGHT LOWS) WILL APPROACH RECORD VALUES. WHAT
IS NOT ENTIRE CLEAR IS IF WE ARE LOOKING AT A WIDESPREAD HEAT
WARNING EVENT OR JUST VERY WARM READINGS. WHAT IS INTERESTING TO
NOTE IS THE NEW ECMWF HAS 850 MB TEMPS CLOSET TO 28-30C WHILE THE
GFS IS NOW MORE IN THE 30-32C RANGE. CLOSER TO THE COAST...THERE
IS UNCERTAINTY IF THE HEAT WILL PUSH ALL OF THE WAY TO THE OCEAN
OR IF THE THERMAL TROUGH WILL NOT BE ABLE TO MAKE IT THAT FAR.
ALSO WORTH POINTING OUT THAT THE TEMPERATURE ANOMALIES ARE ONLY
EXPECTED TO BE 2 TO 3 ABOVE NORMAL -- STILL IMPRESSIVE, HOWEVER
SHORT OF NUMBERS THAT WE LIKE TO SEE FOR A MAJOR EVENT.
OVERNIGHT LOWS WILL ALSO BE OF NOTE FROM THE EVENT WITH MANY
HIGHER ELEVATION LOCATIONS STRUGGLING TO COOL OUT OF THE 70S (SOME
SPOTS MAY STAY IN THE LOWER 80S AT NIGHT). MANY URBAN SPOTS WILL
LIKELY STAY IN THE 60S. AFTER LOOKING AT THE VARIOUS SOLUTIONS,
DECIDED TO BOOST SOME OF THE HIGHS (ESPECIALLY NEAR THE COAST) AND
LOWS FOR HIGHER ELEVATION SPOTS PLUS PARTS OF THE SANTA CLARA
VALLEY.
CPC KEEPS THE WARMER THAN NORMAL WEATHER CONTINUING OUT FOR THE
6-10 AND 8-14 DAY PERIODS WITH AN ABOVE NORMAL CONFIDENCE LEVEL.
THAT WOULD TAKE US OUT TO JULY 9TH.
&&
.AVIATION...AS OF 4:35 AM PDT WEDNESDAY...UPPER LEVEL HIGH
PRESSURE WILL CONTINUE TO BUILD OVER THE REGION THROUGH THE
FORECAST. ABUNDANT STRATUS OFFSHORE AND HIGH SURFACE MOISTURE (DUE
TO THE RAIN SHOWERS OVER THE PAST FEW DAYS) WILL MAKE FOR A
DIFFICULT FORECAST THROUGH AT LEAST THE EARLY AFTERNOON HOURS.
POSSIBLE REDUCED VISIBILITIES MAY IMPACT THE TERMINALS THROUGH THE
EARLY MORNING HOURS. OTHERWISE...MODERATE WEST WINDS WILL BE
PRESENT ACROSS THE AREA THIS AFTERNOON THROUGH THE EARLY EVENING
HOURS.
VICINITY OF KSFO...POSSIBLE IFR CIGS THROUGH 16Z. VERY LOW
CONFIDENCE. VFR CONDITIONS WILL BE POSSIBLE AFTER
19Z...HOWEVER...A FEW OF THE SHORT TERM MODELS INDICATE CLEARING A
FEW HOURS LATER...CLOSER TO 21Z. MODERATE ONSHORE TO 15 KT THIS
AFTERNOON.
KSFO BRIDGE APPROACH...PATCHY LOW CLOUDS MAY IMPACT THE APPROACH
AN HOUR LATER THAN THE TERMINAL. LOW CONFIDENCE.
MONTEREY BAY AREA TERMINALS...POSSIBLE VLIFR CIGS AND VIS POSSIBLE
THROUGH THE EARLY MORNING HOURS. THE HRRR AND LOCAL WRF INDICATE
THAT KMRY COULD SEE LOW CLOUDS ALL DAY...ADDING TO THE UNCERTAINTY
OF THE FORECAST. OTHERWISE...MODERATE ONSHORE THIS AFTERNOON WITH
AN EARLY RETURN OF STRATUS THIS EVENING.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
$$
PUBLIC FORECAST: BELL
AVIATION/MARINE: RILEY
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 MOUNT HOLLY NJ
1014 AM EDT WED JUN 26 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OFF THE EAST COAST AND ACROSS THE ATLANTIC
OCEAN INTO NEXT WEEK. A LEE SIDE TROUGH WILL REMAIN ACROSS THE AREA
TODAY INTO TONIGHT. AN AREA OF LOW PRESSURE WILL MOVE OUT OF THE
OHIO RIVER VALLEY AND INTO THE NORTHEAST THURSDAY INTO THURSDAY
NIGHT, BRINGING A SLOW MOVING COLD FRONT INTO THE AREA THAT WILL
LIKELY STALL OUT ALONG THE EAST COAST INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
CHALLENGING DAY AHEAD... THE 12Z IAD SOUNDING IS HOT...96F FULL SUN.
CONVECTIVELY IT LOOKS A LITTLE DRY AND AT 93/66...DOESN`T FIRE STORMS.
FURTHER NORTH WHERE NO ACTUAL SOUNDING...WE PRESUME MORE UNSTABLE...
ESPECIALLY BENEATH A MODELED SHORT WAVE TRANSLATING EWD ALONG AND
N OF 40N THRU PA/NJ THIS AFTN.
WILL ADJUST TEMPS SLIGHTLY THE NEXT SEVERAL HOURS UNDER HEAVIER
MID MORNING CLOUD COVER NE PA AND NNJ.
HEAT ADVISORY: MAY DISCONTINUE AT 1115 AM. SFC DEWPOINTS ARE ABOUT
3-4F LESS THAN 24 HOURS AGO AND SO WITH A MAX TEMP PROJECTED AROUND
93F...MAX HI 96. NOT QUITE OUR CRITERIA OF 98 IN LATE JUNE.
CONVECTIVELY... THE 13Z RAP HAS SCT TSTMS BREAKING OUT IN THE NW
1/3 RD OF OUR AREA AROUND 21Z VIA THE MORE RELIABLE STABLE PCPN
OUTPUT. RAP CONVECT BEGINS 1-2 HOURS SOONER. 1355Z COSPA GIVE PHL
TIL AT LEAST 19Z BEFORE CONVECTION DEVELOPS ON ITS DOORSTEP. COSPA
STILL DEVELOPS A LARGE AREA OF BANDED HEAVY CONVECTION IN SE PA
BETWEEN 20-22Z.
12Z NAM LOOKS LIT UP A LITTLE EARLY AT 18Z AND SO THAT AFFECTS ITS
SFC TEMP FCST WHICH IS STILL 90 AT 18Z AT KPHL.
MLCAPE HAS ABOUT 2000 J THIS AFTN. BULK SHEAR LOOKS WEAK BUT AS
PER YDY... ISOLATED SVR ARE POSSIBLE IN THE MID-UPPER 90S HEAT
INDEX REGION WITH PLENTY OF CAPE.
TONIGHT...CONVECTION DIMINISHES SEWD THRU S NJ AND DELMARVA AROUND
02-04Z AND ANOTHER FAIR HUMID HAZY NIGHT IS IN STORE.
&&
.SHORT TERM /THURSDAY/...
HEAVY CONVECTION EXPECTED IN THE AFTN OR EARLY AT NIGHT WITH AN
APPROACHING TROUGH AND LOWERING SFC PRES. KI IS MORE WIDESPREAD
THAN THAT OF TODAY.
MAX TEMPS AROUND 2F LOWER THAN THOSE OF TODAY AND SO STILL A
SMALL CHANCE OF 90F FOR S NJ AND THE PHL AREA SOUTHWESTWARD...
DEPENDENT ON CLOUD COVER AND PCPN PRIOR TO 18Z.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
BY THURSDAY, THE LEE SIDE TROUGH WILL GET SQUEEZED OUT AS AN AREA OF
LOW PRESSURE MOVES OUT OF THE OHIO RIVER VALLEY AND INTO THE
NORTHEAST THURSDAY INTO THURSDAY NIGHT, WHILE BRINGING A COLD FRONT
ACROSS. THIS LOW PRESSURE WILL DRIFT NORTHWARD THROUGH THE NORTHEAST
AND INTO CANADA FRIDAY INTO THE WEEKEND. THE AFOREMENTIONED FRONT
WILL LIKELY STALL ALONG THE EAST COAST INTO THE WEEKEND. A LONG WAVE
TROUGH LOOKS TO DEVELOP FROM EASTERN CANADA, THROUGH THE GREAT LAKES
AND INTO BUILD DOWN INTO THE CENTRAL GULF STATES DURING THE WEEKEND
INTO EARLY NEXT WEEK. THIS WILL KEEP A SOUTHWEST FLOW ACROSS THE
AREA FOR A PROLONGED PERIOD. WITH THE FRONTAL BOUNDARY NEAR THE AREA
AND PERIODIC SHORT WAVES/VORT MAX IMPULSES EMBEDDED IN THE CYCLONIC
FLOW, THIS WILL BE A FAIRLY UNSETTLED WEATHER PATTERN. EACH PERIOD
WILL HAVE CHANCE/LIKELY POP, AND WITH THE WARM, UNSTABLE AIRMASS,
THUNDERSTORMS WILL BE POSSIBLE EACH DAY AS WELL. PW VALUES WILL
REMAIN HIGH, AROUND 1.5-2 INCHES, SO HEAVY RAIN WILL BE A CONCERN.
TEMPERATURES WILL REMAIN FAIRLY WARM AND ARE EXPECTED TO BE A FEW
DEGREES ABOVE NORMAL EACH DAY, ALTHOUGH NOT AS WARM AS THE BEGINNING
OF THIS WEEK.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
TODAY...VFR SCT-BKN CLOUDS AOA 5000 FT. SW WIND G 15 KT. BANDS OF
TSTMS DEVELOP AFTER 18Z IN E PA WITH MOSTLY W-NW GUSTS 30-40 KT
AND BRIEF IFR CONDITIONS IN TSTMS.
TONIGHT...LEFTOVER CONVECTION DIES AND SO VFR SCT-BKN AOA 5000 FT.
POSSIBLE MVFR FOG HAZE LATE. LIGHT S-SW WIND. CONFIDENCE IN PRECIP/
CLOUDS TONIGHT IS LESS THAN AVERAGE.
THURSDAY...AFTER ANY EARLY MVFR HAZE...VFR SCT-BKN CLOUDS AOA 5000
FT WITH BANDS OF IFR TSTMS IN THE AFTN/EVENING GENERATING W WIND
GUSTS 30-40 KT.
OUTLOOK...
THURSDAY THROUGH SUNDAY...GENERALLY VFR WITH PERIODS OF MVFR/IFR
POSSIBLE EACH DAY WITH SHOWERS AND THUNDERSTORMS AND MORNING LOW
CLOUDS/FOG.
&&
.MARINE...
THE PRESSURE GRADIENT OVER THE WATERS TODAY WILL FAVOR A SW FLOW
WITH SPEEDS AROUND 10 TO 15 KNOTS. SEAS SHOULD REMAIN IN THE 3 TO 4
FT RANGE OUT OVER THE OCEAN WATERS AND 1 TO 2 FEET ON DEL BAY. WHILE
SCA CONDITION ARE NOT EXPECTED TODAY AND TONIGHT...TSTMS WITH GUSTY
WINDS ARE POSSIBLE THIS AFTERNOON AND TONIGHT. BE PREPARED FOR
HIGHER WINDS AND SEAS IN ANY TSTM. SMW`S MAY BE ISSUED LATER TODAY.
THURSDAY...THE SLY FLOW STRENGTHENS AHEAD OF THE APPROACHING TROUGH
AND DEEPENING SFC LOW INTO N PA AND S NYS. SCA SOUTHERLY FLOW SEAS
MAY REACH CRITERIA ON THE ATLC WATERS BUT THERE IS QUESTION
WHETHER THE WAA IS OVERFORECASTING THE SLY SWELL.
OUTLOOK...
SMALL CRAFT ADVISORY CONDITIONS MAY RETURN TO THE ATLANTIC COASTAL
WATERS INTO THE WEEKEND. SOUTHWEST WINDS ARE EXPECTED TO INCREASE
AHEAD OF AN APPROACHING COLD FRONT THAT WILL STALL ALONG THE EAST
COAST THROUGH THE WEEKEND. WINDS MAY PERIODICALLY GUSTA ROUND 25
KNOTS THROUGH THE PERIOD. ALSO, SEAS ARE FORECAST TO BUILD TO 5-6
FEET WITH THE SOUTHWESTERLY FLOW AS WELL.
&&
.RIP CURRENTS...
LOW RISK TODAY BUT NOT A NO RISK!! MARGINALLY LOW TOMORROW IN NJ
IF THE SLY SWELL BUILDS TO 4 FT WITH A 7 SEC PERIOD AND THE S WIND
AVERAGES 14 KT MIDDAY.
&&
.CLIMATE...
TEMPS BELOW...
PROJECTING AN ABOVE NORMAL MONTH FOR ALL STATIONS ON THE ORDER OF
1 TO 2 DEGREES EXCEPT A LITTLE LESS THAN A DEGREE ABOVE NORMAL AT
KACY.
PHL SPECIFICALLY PROJECTS 74.5 OR 1.3 ABOVE NORMAL. THE JUNE 1981-2010 AVG
IS 73.2.
JUNE RAINFALL BELOW..
KILG ALREADY RECORD MONTHLY RFALL AT 10.09
KPHL RANKED #2 AT 8.80 INCHES BEHIND THE 10.06 JUNE 1998 RECORD.
KACY RANKED #3 AT 7.20 BEHIND THE 7.57 IN 1935 AND RECORD JUNE
TOTAL OF 8.45 IN 1920.
KABE STILL RANKED 8TH WETTEST JUNE AT 6.48 INCHES. THE MONTHLY
RECORD IS 10.51 IN 1938.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR PAZ070-071-102-
104-106.
NJ...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NJZ015-017>019.
DE...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR DEZ001.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...ROBERTSON
NEAR TERM...DRAG/O`HARA 1015
SHORT TERM...DRAG/O`HARA 1015
LONG TERM...ROBERTSON
AVIATION...DRAG/ROBERTSON/O`HARA 1015
MARINE...DRAG/ROBERTSON/O`HARA 1015
RIP CURRENTS...
CLIMATE...1015
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
914 AM EDT WED JUN 26 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OFF THE EAST COAST AND ACROSS THE ATLANTIC
OCEAN INTO NEXT WEEK. A LEE SIDE TROUGH WILL REMAIN ACROSS THE AREA
TODAY INTO TONIGHT. AN AREA OF LOW PRESSURE WILL MOVE OUT OF THE
OHIO RIVER VALLEY AND INTO THE NORTHEAST THURSDAY INTO THURSDAY
NIGHT, BRINGING A SLOW MOVING COLD FRONT INTO THE AREA THAT WILL
LIKELY STALL OUT ALONG THE EAST COAST INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
CHALLENGING DAY AHEAD... THE 12Z IAD SOUNDING IS HOT...96F FULL SUN.
CONVECTIVELY IT LOOKS A LITTLE DRY AND AT 93/66...DOESN`T FIRE
STORMS. FURTHER NORTH WHERE NO ACTUAL SOUNDING...WE PRESUME MORE
UNSTABLE...ESPECIALLY BENEATH A MODELED SHORT WAVE TRANSLATING
EWD ALONG AND N OF 40N THRU PA/NJ THIS AFTN.
SO...THE HEAT ADVISORY CONTINUES AS THE POORLY MODELED W PA CONVECTION
CONTINUES TO FRITTER PERMITTING PLENTY OF SUN. KEEPING AN EYE ON
THE 1218Z CONVECTION NEAR KEKN BUT FOR NOW THINKING IT TENDS TO
WANE.
CONVECTIVELY... THE 10Z RAP HAS THE PCPN BREAKING OUT SUDDENLY IN
THE NW 1/3 RD OF OUR AREA AROUND 21Z VIA THE MORE RELIABLE STABLE
PCPN OUTPUT. RAP CONVECT BEGINS 1-2 HOURS SOONER. THE COSPA GIVE
PHL TIL 19Z BEFORE CONVECTION DEVELOPS ON ITS DOORSTEP. COSPA DEVELOPS
A LARGE AREA OF BANDED HEAVY CONVECTION IN SE PA BETWEEN 19-21Z.
MLCAPE HAS ABOUT 2000 J THIS AFTN. BULK SHEAR LOOKS WEAK BUT AS
PER YDY... ISOLATED SVR ARE POSSIBLE IN THE MID-UPPER 90S HEAT
INDEX REGION WITH PLENTY OF CAPE.
TONIGHT...CONVECTION DIMINISHES AND ANOTHER FAIR HUMID HAZY NIGHT
IS IN STORE.
&&
.SHORT TERM /THURSDAY/...
HEAVY CONVECTION EXPECTED IN THE AFTN OR EARLY AT NIGHT WITH AN
APPROACHING TROUGH. KI IS MORE WIDESPREAD THAN THAT OF TODAY.
MAX TEMPS AROUND 2F LOWER THAN THOSE OF TODAY AND SO STILL A
SMALL CHANCE OF 90F FOR S NJ AND THE PHL AREA SOUTHWESTWARD...
DEPENDENT ON CLOUD COVER AND PCPN PRIOR TO 18Z.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
BY THURSDAY, THE LEE SIDE TROUGH WILL GET SQUEEZED OUT AS AN AREA OF
LOW PRESSURE MOVES OUT OF THE OHIO RIVER VALLEY AND INTO THE
NORTHEAST THURSDAY INTO THURSDAY NIGHT, WHILE BRINGING A COLD FRONT
ACROSS. THIS LOW PRESSURE WILL DRIFT NORTHWARD THROUGH THE NORTHEAST
AND INTO CANADA FRIDAY INTO THE WEEKEND. THE AFOREMENTIONED FRONT
WILL LIKELY STALL ALONG THE EAST COAST INTO THE WEEKEND. A LONG WAVE
TROUGH LOOKS TO DEVELOP FROM EASTERN CANADA, THROUGH THE GREAT LAKES
AND INTO BUILD DOWN INTO THE CENTRAL GULF STATES DURING THE WEEKEND
INTO EARLY NEXT WEEK. THIS WILL KEEP A SOUTHWEST FLOW ACROSS THE
AREA FOR A PROLONGED PERIOD. WITH THE FRONTAL BOUNDARY NEAR THE AREA
AND PERIODIC SHORT WAVES/VORT MAX IMPULSES EMBEDDED IN THE CYCLONIC
FLOW, THIS WILL BE A FAIRLY UNSETTLED WEATHER PATTERN. EACH PERIOD
WILL HAVE CHANCE/LIKELY POP, AND WITH THE WARM, UNSTABLE AIRMASS,
THUNDERSTORMS WILL BE POSSIBLE EACH DAY AS WELL. PW VALUES WILL
REMAIN HIGH, AROUND 1.5-2 INCHES, SO HEAVY RAIN WILL BE A CONCERN.
TEMPERATURES WILL REMAIN FAIRLY WARM AND ARE EXPECTED TO BE A FEW
DEGREES ABOVE NORMAL EACH DAY, ALTHOUGH NOT AS WARM AS THE BEGINNING
OF THIS WEEK.
&&
.AVIATION /13Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
TODAY...VFR SCT-BKN CLOUDS AOA 5000 FT. SW WIND G 15 KT. BANDS OF
TSTMS DEVELOP AFTER 18Z IN E PA WITH MOSTLY W-NW GUSTS 30-40 KT
AND BRIEF IFR CONDITIONS IN TSTMS.
TONIGHT...LEFTOVER CONVECTION DIES AND SO VFR SCT-BKN AOA 5000 FT.
POSSIBLE MVFR FOG HAZE LATE. LIGHT S-SW WIND. CONFIDENCE IN PRECIP/CLOUDS
TONIGHT IS LESS THAN AVERAGE.
THURSDAY...AFTER ANY EARLY MVFR HAZE...VFR SCT-BKN CLOUDS AOA 5000
FT WITH BANDS OF IFR TSTMS IN THE AFTN/EVENING GENERATING W WIND
GUSTS 30-40 KT.
OUTLOOK...
THURSDAY THROUGH SUNDAY...GENERALLY VFR WITH PERIODS OF MVFR/IFR
POSSIBLE EACH DAY WITH SHOWERS AND THUNDERSTORMS AND MORNING LOW
CLOUDS/FOG.
&&
.MARINE...
THE PRESSURE GRADIENT OVER THE WATERS TODAY WILL FAVOR A SW FLOW
WITH SPEEDS AROUND 10 TO 15 KNOTS. SEAS SHOULD REMAIN IN THE 3 TO 4
FT RANGE OUT OVER THE OCEAN WATERS AND 1 TO 2 FEET ON DEL BAY. WHILE
SCA CONDITION ARE NOT EXPECTED TODAY AND TONIGHT...TSTMS WITH GUSTY
WINDS ARE POSSIBLE THIS AFTERNOON AND TONIGHT. BE PREPARED FOR
HIGHER WINDS AND SEAS IN ANY TSTM. SMW`S MAY BE ISSUED LATER TODAY.
THURSDAY...THE SLY FLOW TIGHTENS A BIT AHEAD OF THE APPROACHING
TROUGH AND THAT MAY BE ENOUGH TO DEVELOP SCA SOUTHERLY SWELL SEAS
BUT THERE IS QUESTION WHETHER THE WAA IS OVER FORECASTING THE SLY
SWELL.
OUTLOOK...
SMALL CRAFT ADVISORY CONDITIONS MAY RETURN TO THE ATLANTIC COASTAL
WATERS INTO THE WEEKEND. SOUTHWEST WINDS ARE EXPECTED TO INCREASE
AHEAD OF AN APPROACHING COLD FRONT THAT WILL STALL ALONG THE EAST
COAST THROUGH THE WEEKEND. WINDS MAY PERIODICALLY GUSTA ROUND 25
KNOTS THROUGH THE PERIOD. ALSO, SEAS ARE FORECAST TO BUILD TO 5-6
FEET WITH THE SOUTHWESTERLY FLOW AS WELL.
&&
.RIP CURRENTS...
LOW TODAY. MARGINALLY LOW TOMORROW IN NJ IF THE SLY SWELL BUILDS TO
4 FT WITH 7 SEC AND THE S WIND AVERAGES 14 KT MIDDAY.
&&
.CLIMATE...
PROJECTING AN ABOVE NORMAL MONTH FOR ALL STATIONS ON THE ORDER OF
1 TO 2 DEGS REES EXCEPT A LITTLE LESS THAN A DEGREE ABOVE NORMAL
AT KACY.
PHL SPECIFICALLY PROJECTS 74.5 OR 1.3 ABOVE NORMAL. THE JUNE AVG IS
73.2.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR PAZ070-071-102-
104-106.
NJ...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NJZ015-017>019.
DE...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR DEZ001.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...ROBERTSON
NEAR TERM...DRAG/O`HARA 913
SHORT TERM...DRAG/O`HARA 913
LONG TERM...ROBERTSON
AVIATION...DRAG/ROBERTSON/O`HARA 913
MARINE...DRAG/ROBERTSON/O`HARA 913
RIP CURRENTS...913
CLIMATE...913
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1110 AM EDT Wed Jun 26 2013
.NEAR TERM [Rest of Today]...
No significant changes were made to the inherited forecast which
seems to be generally on track. Isolated to scattered afternoon
thunderstorms are expected today, with somewhat lower coverage than
what we saw yesterday. The best coverage of thunderstorms should be
in the eastern portions of our forecast area - from south-central
Georgia into the Florida Big Bend. The PoP gradient was sharpened a
bit - nudged to ~50% in the Suwannee River vicinity and lowered to
~20% in parts of southeast Alabama. High temperatures remain mostly
unchanged in the mid-90s away from the coasts. We can`t rule out a
stronger storm or two, as is typical this time of year along the
Gulf coast (our climatological probability is ~2% chance of damaging
winds within 25 miles of a point for today). However, a slight
drying in the boundary layer over the past 24 hours should yield a
less robust CAPE profile today which points to lower chances of
isolated severe storms than we saw yesterday.
&&
.SHORT TERM [Thursday through Friday]...
Upper level trofing will continue dipping further south over the Ern
CONUS through the period. This will continue to veer the flow from
SWrly flow to Wrly. The flow Thursday will be moderate (<10 kts),
which would mean a regime 4 sea breeze day. Generally these days have
lots of showers and thunderstorms in north Florida near the coast,
but drier air from the west will enter the region and should keep
coverage a little lower. In fact, because of a cold front to our
north on Thursday, our northern counties have a slightly better
chance for rain on Thursday afternoon than our Florida counties do.
Friday, the flow will be stronger (>10 kts), meaning a regime 5
sea breeze day. These days typically see an earlier start and are
active inland, not just along the coast. As the cold front dips
further south Friday, expanded morning type 5 PoPs north and have a
blend of model confidence and sea breeze for the afternoon, giving a
broad area of chances for showers and thunderstorms Friday. Highs
Thursday will be in the mid 90s and lows Thursday night will be in
the mid 70s.
&&
.LONG TERM [Friday Night through Tuesday]...
A highly amplified upper level pattern with a deep trough becoming
firmly established over the eastern CONUS through the period. A
series of impulses are forecast to round the base of the trough
enhancing convection over the Tri-state area. A fairly potent
shortwave is forecast by the GFS to arrive on Saturday. The Bermuda
ridge will build westward early next week with the axis of the
trough retrograding to the Mississippi Valley. This will place the
local region under deep and very moist southwest flow. From all
appearances this will be an active period for convection with at
least climo PoPs (40-50%) each afternoon. Temps will be near
seasonal levels.
&&
.AVIATION...
[Through 12Z Thursday] A somewhat tricky TAF package for the
overnight hours, as the usually very reliable NARRE and HRRR are
generally devoid of any significant restrictions. Some of the
numerical guidance did show some MVFR level cigs or vis, so did fcst
periods of MVFR conditions at ECP and DHN, which were the 2 sites
that had the most measurable rainfall yesterday. As for the daylight
hours, it appears to be fairly convectively quiet for a Type 4 sea
breeze day with the upper level ridge dominating, but did go with 30
and 40 percent PoPs as mentioned above. Left ECP free from
convection at this time, went with prob30 groups at TLH and DHN, and
finally convective tempos at ABY and VLD.
&&
.MARINE...
Winds and waves over coastal waters will begin to pick up a bit this
weekend as a front approaches from our north. Winds will shift to
westerly at around 10-15 kts with waves building to 2-3 feet Friday
into Saturday. By Sunday, winds will be around 15 kts and waves may
reach about 4 feet, but should begin decreasing again by Monday.
Exercise caution conditions are possible on Sunday.
&&
.FIRE WEATHER...
Relative humidity values will stay safely above Red Flag criteria
through the period.
&&
.HYDROLOGY...
With no river sites currently in flood stage or action stage, and
with QPF for the next 3 days from WPC of <1", no flooding on area
rivers is expected in the next few days. Later this weekend and
early into next week, there is some potential for higher rainfall
amounts as a frontal system dips southward into our area, but they
should still be too low to cause widespread flooding. WPC is showing
QPF of 1-1.5" for Saturday through Sunday and 1-1.75" Monday through
Tuesday.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 96 73 94 74 93 / 40 30 30 20 50
Panama City 90 77 91 78 89 / 30 20 30 20 40
Dothan 94 74 95 75 94 / 30 20 30 30 50
Albany 95 74 95 74 93 / 30 20 40 30 40
Valdosta 94 71 94 74 93 / 50 30 30 30 50
Cross City 93 73 93 73 91 / 40 30 30 20 40
Apalachicola 89 75 89 77 88 / 30 20 20 20 40
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...Lamers
SHORT TERM...Moore
LONG TERM...Barry
AVIATION...Gould
MARINE...Moore
FIRE WEATHER...Gould
HYDROLOGY...Moore
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
920 AM CDT WED JUN 26 2013
.DISCUSSION...
308 AM CDT
THE LATEST IN A SERIES OF WEAK SHORTWAVES IN QUASI-ZONAL SOUTHERN
STREAM FLOW HAS BEEN SUPPORTING WIDESPREAD CONVECTION AS IT MOVES
TOWARD THE AREA EARLY THIS MORNING. GRADUALLY OVER THE NEXT TWO
DAYS THE LARGE SCALE PATTERN WILL BE AMPLIFYING INTO A BROAD
ANTICYCLONE ACROSS THE WESTERN CONUS AND A DEEPENING LONGWAVE TROUGH
OVER THE EASTERN STATES. THE WARM HUMID CONDITIONS OF RECENT DAYS
WILL BE REPLACED BY COOL HUMID CONDITIONS BY THE WEEKEND...WHICH
THEN WILL PERSIST INTO NEXT WEEK.
FIRST QUESTION CONCERNS PRECIPITATION TRENDS FOR TODAY. AT 08Z THE
EXISTING AREAS OF CONVECTION ACROSS NORTHEAST IOWA INTO NORTHERN
ILLINOIS WERE LOCATED ALONG FAVORABLE GRADIENTS OF MOISTURE
TRANSPORT ON THE LEADING EDGE OF THE LOW LEVEL JET...AND UNDER A
WEAK SHORTWAVE DEPICTED IN THE RAP MODEL AND VWP OBS AT 850 AND 700
MB. THIS ACTIVITY SHOULD BE MOVING ACROSS NORTHEASTERN ILLINOIS
DURING THE PREDAWN HOURS BUT THEN BEGINNING TO WEAKEN AS THE
LLJ VEERS AND ADJUSTS ITS FOCUS MORE TOWARD CENTRAL AND SOUTHERN
ILLINOIS.
IF THIS ACTIVITY DOES DISSIPATE AS EXPECTED TOWARD MORNING...THE
PROSPECTS OF REDEVELOPMENT TODAY ARE SOMEWHAT UNCERTAIN DESPITE
MODEL QPF SOLUTIONS TO THE CONTRARY. LINGERING MORNING SHOWERS AND
THEN SCATTERED TSRA LATER ARE DEFINITELY NOT OUT OF THE QUESTION
LOCALLY BUT THE MORE FAVORABLE AREAS OF MOISTURE ADVECTION AND STEEP
MID LEVEL LAPSE RATES ARE FARTHER SOUTH TOWARD CENTRAL ILLINOIS AND
FARTHER NORTH ALONG THE WI/MN STATE LINE.
DESPITE THE APPROACH OF A SURFACE/850 FRONTAL ZONE...THE UPPER LEVEL
WAVES APPEAR TO BE SOMEWHAT OUT OF SYNC AND MORE
PROGRESSIVE...LEAVING THE LOWER LEVEL FEATURES UNDER AREAS OF RISING
HEIGHTS ALOFT. IN THE 0530Z SPC DAY 1 OUTLOOK THE SLIGHT RISK
EXTENDS NORTHWEST TOWARD MSP AND THEN WELL SOUTH AND EAST THROUGH
THE TENNESSEE AND OHIO VALLEYS. WOULD NOT BE SURPRISED TO SEE THIS
SPLIT IN LATER UPDATES...WITH THE THUMB TO OUR NORTHWEST SEPARATED
FROM THE AREA TO OUR SOUTH. BUT THAT WOULD BE CUTTING IT PRETTY
FINE GIVEN THE OVERALL UNCERTAINTY WITH THIS SITUATION.
LONG STORY SHORT...FOR TODAY THE PLAN WILL BE TO LOWER POPS INTO THE
CHANCE CATEGORY BY AFTERNOON FOR MOST OF THE AREA BUT KEEP IN MIND
THE PWATS APPROACHING TWO INCHES AND THEREFORE MAINTAIN THE FLASH
FLOOD WATCH AND THE MENTION OF TSRA.
AFTER TODAY THE SITUATION BECOMES ONLY SLIGHTLY MORE CLEAR BUT OF
SEEMINGLY LESSER IMPACT.
AMPLIFICATION OF THE LARGE SCALE FLOW WILL BEGIN TO INFLUENCE THE
LOCAL AREA BY TONIGHT INTO THURSDAY AFTER THE SURFACE TROUGH PUSHES
THROUGH THE AREA AND WINDS AT ALL LEVELS TURN TO THE NORTHWEST. LOW
LEVEL WARMTH AND HUMIDITY DO NOT REALLY DEPART UNTIL FRIDAY WHEN THE
EXPANDING EASTERN TROUGH PUSHES THE UPPER JET SOUTH OF THE AREA AND
USHERS IN SLIGHTLY DRIER BUT MILDER AIR.
WITH ONLY MARGINAL LAPSE RATES AND HEIGHTS ALOFT CONTINUING TO
INCREASE...NEITHER THURSDAY NOR FRIDAY LOOK PARTICULARLY FAVORABLE
FOR WIDESPREAD PRECIPITATION. AS MENTIONED IN AN EARLIER
DISCUSSION...IT WOULD NOT TAKE MUCH OF A SHORTWAVE IN THE UPPER FLOW
TO SUPPORT AN AFTERNOON SHOWER...SO WILL CONTINUE TO CARRY SLIGHT
CHANCE POPS ON BOTH DAYS.
BY THE WEEKEND THE CONVECTIVE INSTABILITY APPEARS TO HAVE
DECREASED...BUT THE PRESENCE OF BOTH A SURFACE AND UPPER LEVEL
TROUGH DROPPING SOUTH ACROSS THE AREA WILL STILL SUPPORT LARGE SCALE
LIFT...PRIMARILY TO THE SOUTH ON SUNDAY. PRECIP CHANCES FINALLY
DECREASE BY EARLY NEXT WEEK AS THE SURFACE AND UPPER SUPPORT
DIMINISH...BUT UNSEASONABLY COOL AIR REMAINS IN PLACE WITH CONTINUED
NORTH TO NORTHEASTERLY WINDS.
LENNING
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* SCT`D SHRA & TSRA LIKELY TO PERSIST NEXT FEW HOURS
* EASTERLY COMPONENT TO WINDS EXPECTED NEXT SEVERAL HOURS
* WINDS COULD TRANSITION TO SOUTHERLY OR SOUTHEAST THIS AFTERNOON
IZZI
//DISCUSSION...UPDATED 14Z...
UPPER LEVEL DISTURBANCE MOVING ACROSS NORTHERN ILLINOIS WILL
CONTINUE TO PRODUCE SCT`D SHOWERS AND THUNDERSTORMS THROUGH THE
REMAINDER OF THE MORNING HOURS. MORE ORGANIZED LINE OF TSRA SW OF
JOT WILL LIFT NE AND LIKELY IMPACT MDW BY AROUND 15Z WITH PERIOD
OF +TSRA AND GUSTY WINDS POSSIBLE. AS DISTURBANCE MOVES SLOWLY
EAST THE COVERAGE OF SHRA/TSRA WILL PROBABLY DECREASE THIS
AFTERNOON. SMALL SFC LOW SW OF RFD LIKELY TO MAINTAIN MOSTLY
EASTERLY COMPONENT TO WINDS THROUGH THE MORNING HOURS WITH LOW
CONFIDENCE ON THE WIND DIRECTION HEADING INTO THE AFTERNOON.
IZZI
UPDATED 12Z...
LINE OF THUNDERSTORMS SPANS FROM NORTH CENTRAL ILLINOIS ESE INTO
NORTHERN INDIANA AND IS FOCUSED ON THE NOSE OF A LOW LEVEL JET.
WHILE THE FOCUS SHOULD GENERALLY LIFT NORTH AND WEAKEN OVER THE NEXT
COUPLE HOURS...THE STORMS HAVE BEEN BACK BUILDING TO THE SOUTH WHICH
HAS KEPT IT OVER OR ON THE DOORSTEP ON ORD...AND MAY CONTINUE TO
PERSIST OVER THE NEXT HOUR OR TWO. WINDS HAVE BECOME MORE
NORTHEAST/EASTERLY UNDER THE INFLUENCE OF CONVECTION...AND CIGS HAVE
DROPPED TO MVFR. AS CONVECTION WANES THIS MORNING...EXPECT SOUTHERLY
WINDS TO RESUME AND FOR MVFR CIGS TO LIFT BACK TO VFR. THERE SHOULD
BE A LULL IN ACTIVITY FROM MID MORNING TO EARLY THIS AFTERNOON FOR
THE CHICAGO TERMINALS. ATTENTION TURNS TO AN APPROACHING MCV MOVING
OVER THE MISSISSIPPI RIVER EARLY THIS MORNING. WHILE THERE IS AN
EXPANSIVE AREA OF STRATIFORM PRECIP AHEAD OF THIS FEATURE...IT
SHOULD DRY/ERODE SOME AS IT PROGRESSES EAST. BECAUSE OF THE CLOUD
COVER AND PERHAPS LIGHT RAIN...IT APPEARS THERE WILL BE LITTLE
OPPORTUNITY FOR THE ATMOSPHERE TO DESTABILIZE TODAY THOUGH THERE
WILL BE SOME PERSISTENT/FESTERING EMBEDDED CONVECTION ASSOCIATED
WITH THE MCV. WINDS APPEAR TO GO LIGHT AND VARIABLE TONIGHT...AND
NAM GUIDANCE AS WELL AS LAV POINT TO FOG/BR AND IFR CIGS DEVELOPING
OVERNIGHT. WILL NOT MENTION YET IN TAFS TO WAIT AND SEE HOW THE REST
OF THE DAY EVOLVES AND IF THERE IS ANY SIGNIFICANT DRYING THIS
AFTERNOON/EVENING.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM-HIGH CONFIDENCE IN SHRA/TSRA OVER THE REGION THIS MORNING
* LOW CONFIDENCE IN SHRA/TSRA CHANCES THIS AFTERNOON
* MEDIUM CONFIDENCE IN WIND DIRECTION OUTSIDE OF TSRA THIS MORNING
* LOW CONFIDENCE IN WINDS THIS AFTERNOON
IZZI
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...VFR.
FRIDAY THROUGH SATURDAY...PERIODIC CHANCES OF TSRA.
SATURDAY THROUGH MONDAY...PERIODIC CHANCES OF SHRA.
TUESDAY...CHC TSRA.
BMD
&&
.MARINE...
150 AM CDT
ELONGATED SFC LOW PRESSURE TROUGH OVER THE MID-UPPER MISSOURI
VALLEY WILL MOVE SLOWLY EAST TODAY...WITH VARYING MODEL FORECASTS
DEVELOPING A WEAK SURFACE LOW PRESSURE WAVE IN THE VICINITY OF
NORTHERN IL/IND OR SOUTHERN LAKE MICHIGAN BY THIS EVENING. SOUTH
TO SOUTHEAST WINDS SHOULD DIMINISH IN SPEED AS THE GRADIENT
WEAKENS WITH THE APPROACH OF THE TROUGH THIS AFTERNOON...WITH LAKE
BREEZE ESPECIALLY ALONG THE WESTERN SHORE. THUNDERSTORMS WILL BE
POSSIBLE ESPECIALLY OVER THE SOUTHERN HALF OF THE LAKE...WHICH MAY
RESULT IN SOME LOCALLY STRONGER WINDS. WINDS MAY BECOME SOMEWHAT
VARIABLE AT 10 KT OR LESS TONIGHT AS THE SURFACE TROUGH/COLD FRONT
MOVE SLOWLY ACROSS THE LAKE...EVENTUALLY TAKING ON A WEST-
NORTHWEST DIRECTION THURSDAY AS THE TROUGH MOVES OFF TO THE EAST.
SPEEDS SHOULD REMAIN GENERALLY LIGHT HOWEVER...WITH A RELATIVELY
WEAK GRADIENT INTO FRIDAY.
WEAK HIGH PRESSURE RIDGING WILL DEVELOP SOUTHEAST ACROSS THE
NORTHERN AND CENTRAL HIGH PLAINS INTO THE WEEKEND...WHILE THE LOW
PRESSURE WAVE EVENTUALLY DEEPENS EAST OF THE LAKES. THIS WILL
MAINTAIN A PROLONGED PERIOD OF NORTH-NORTHWEST FLOW ACROSS LAKE
MICHIGAN...THOUGH AGAIN WITH SPEEDS GENERALLY 15 KT OR LESS THROUGH
THE PERIOD.
OTHERWISE...IN THE NEAR TERM SOME PATCHY DENSE FOG WILL LINGER
ACROSS THE NORTHERN PART OF THE LAKE THIS MORNING.
RATZER
&&
.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 WEDNESDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 7
PM WEDNESDAY.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
629 AM CDT WED JUN 26 2013
.DISCUSSION...
308 AM CDT
THE LATEST IN A SERIES OF WEAK SHORTWAVES IN QUASI-ZONAL SOUTHERN
STREAM FLOW HAS BEEN SUPPORTING WIDESPREAD CONVECTION AS IT MOVES
TOWARD THE AREA EARLY THIS MORNING. GRADUALLY OVER THE NEXT TWO
DAYS THE LARGE SCALE PATTERN WILL BE AMPLIFYING INTO A BROAD
ANTICYCLONE ACROSS THE WESTERN CONUS AND A DEEPENING LONGWAVE TROUGH
OVER THE EASTERN STATES. THE WARM HUMID CONDITIONS OF RECENT DAYS
WILL BE REPLACED BY COOL HUMID CONDITIONS BY THE WEEKEND...WHICH
THEN WILL PERSIST INTO NEXT WEEK.
FIRST QUESTION CONCERNS PRECIPITATION TRENDS FOR TODAY. AT 08Z THE
EXISTING AREAS OF CONVECTION ACROSS NORTHEAST IOWA INTO NORTHERN
ILLINOIS WERE LOCATED ALONG FAVORABLE GRADIENTS OF MOISTURE
TRANSPORT ON THE LEADING EDGE OF THE LOW LEVEL JET...AND UNDER A
WEAK SHORTWAVE DEPICTED IN THE RAP MODEL AND VWP OBS AT 850 AND 700
MB. THIS ACTIVITY SHOULD BE MOVING ACROSS NORTHEASTERN ILLINOIS
DURING THE PREDAWN HOURS BUT THEN BEGINNING TO WEAKEN AS THE
LLJ VEERS AND ADJUSTS ITS FOCUS MORE TOWARD CENTRAL AND SOUTHERN
ILLINOIS.
IF THIS ACTIVITY DOES DISSIPATE AS EXPECTED TOWARD MORNING...THE
PROSPECTS OF REDEVELOPMENT TODAY ARE SOMEWHAT UNCERTAIN DESPITE
MODEL QPF SOLUTIONS TO THE CONTRARY. LINGERING MORNING SHOWERS AND
THEN SCATTERED TSRA LATER ARE DEFINITELY NOT OUT OF THE QUESTION
LOCALLY BUT THE MORE FAVORABLE AREAS OF MOISTURE ADVECTION AND STEEP
MID LEVEL LAPSE RATES ARE FARTHER SOUTH TOWARD CENTRAL ILLINOIS AND
FARTHER NORTH ALONG THE WI/MN STATE LINE.
DESPITE THE APPROACH OF A SURFACE/850 FRONTAL ZONE...THE UPPER LEVEL
WAVES APPEAR TO BE SOMEWHAT OUT OF SYNC AND MORE
PROGRESSIVE...LEAVING THE LOWER LEVEL FEATURES UNDER AREAS OF RISING
HEIGHTS ALOFT. IN THE 0530Z SPC DAY 1 OUTLOOK THE SLIGHT RISK
EXTENDS NORTHWEST TOWARD MSP AND THEN WELL SOUTH AND EAST THROUGH
THE TENNESSEE AND OHIO VALLEYS. WOULD NOT BE SURPRISED TO SEE THIS
SPLIT IN LATER UPDATES...WITH THE THUMB TO OUR NORTHWEST SEPARATED
FROM THE AREA TO OUR SOUTH. BUT THAT WOULD BE CUTTING IT PRETTY
FINE GIVEN THE OVERALL UNCERTAINTY WITH THIS SITUATION.
LONG STORY SHORT...FOR TODAY THE PLAN WILL BE TO LOWER POPS INTO THE
CHANCE CATEGORY BY AFTERNOON FOR MOST OF THE AREA BUT KEEP IN MIND
THE PWATS APPROACHING TWO INCHES AND THEREFORE MAINTAIN THE FLASH
FLOOD WATCH AND THE MENTION OF TSRA.
AFTER TODAY THE SITUATION BECOMES ONLY SLIGHTLY MORE CLEAR BUT OF
SEEMINGLY LESSER IMPACT.
AMPLIFICATION OF THE LARGE SCALE FLOW WILL BEGIN TO INFLUENCE THE
LOCAL AREA BY TONIGHT INTO THURSDAY AFTER THE SURFACE TROUGH PUSHES
THROUGH THE AREA AND WINDS AT ALL LEVELS TURN TO THE NORTHWEST. LOW
LEVEL WARMTH AND HUMIDITY DO NOT REALLY DEPART UNTIL FRIDAY WHEN THE
EXPANDING EASTERN TROUGH PUSHES THE UPPER JET SOUTH OF THE AREA AND
USHERS IN SLIGHTLY DRIER BUT MILDER AIR.
WITH ONLY MARGINAL LAPSE RATES AND HEIGHTS ALOFT CONTINUING TO
INCREASE...NEITHER THURSDAY NOR FRIDAY LOOK PARTICULARLY FAVORABLE
FOR WIDESPREAD PRECIPITATION. AS MENTIONED IN AN EARLIER
DISCUSSION...IT WOULD NOT TAKE MUCH OF A SHORTWAVE IN THE UPPER FLOW
TO SUPPORT AN AFTERNOON SHOWER...SO WILL CONTINUE TO CARRY SLIGHT
CHANCE POPS ON BOTH DAYS.
BY THE WEEKEND THE CONVECTIVE INSTABILITY APPEARS TO HAVE
DECREASED...BUT THE PRESENCE OF BOTH A SURFACE AND UPPER LEVEL
TROUGH DROPPING SOUTH ACROSS THE AREA WILL STILL SUPPORT LARGE SCALE
LIFT...PRIMARILY TO THE SOUTH ON SUNDAY. PRECIP CHANCES FINALLY
DECREASE BY EARLY NEXT WEEK AS THE SURFACE AND UPPER SUPPORT
DIMINISH...BUT UNSEASONABLY COOL AIR REMAINS IN PLACE WITH CONTINUED
NORTH TO NORTHEASTERLY WINDS.
LENNING
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* LINE OT THUNDERSTORMS EARLY THIS MORNING BACK BUILDING
SOUTH...BUT SHOULD EVENTUALLY BEGIN TO LIFT NORTH AWAY FROM AREA
AND WEAKEN.
* ADDITIONAL THUNDERSTORMS POSSIBLE THIS AFTERNOON ASSOCIATED WITH
THE DECAYING SYSTEM MOVING ACROSS THE MISSISSIPPI.
BMD
//DISCUSSION...UPDATED 12Z...
LINE OF THUNDERSTORMS SPANS FROM NORTH CENTRAL ILLINOIS ESE INTO
NORTHERN INDIANA AND IS FOCUSED ON THE NOSE OF A LOW LEVEL JET.
WHILE THE FOCUS SHOULD GENERALLY LIFT NORTH AND WEAKEN OVER THE NEXT
COUPLE HOURS...THE STORMS HAVE BEEN BACK BUILDING TO THE SOUTH WHICH
HAS KEPT IT OVER OR ON THE DOORSTEP ON ORD...AND MAY CONTINUE TO
PERSIST OVER THE NEXT HOUR OR TWO. WINDS HAVE BECOME MORE
NORTHEAST/EASTERLY UNDER THE INFLUENCE OF CONVECTION...AND CIGS HAVE
DROPPED TO MVFR. AS CONVECTION WANES THIS MORNING...EXPECT SOUTHERLY
WINDS TO RESUME AND FOR MVFR CIGS TO LIFT BACK TO VFR. THERE SHOULD
BE A LULL IN ACTIVITY FROM MID MORNING TO EARLY THIS AFTERNOON FOR
THE CHICAGO TERMINALS. ATTENTION TURNS TO AN APPROACHING MCV MOVING
OVER THE MISSISSIPPI RIVER EARLY THIS MORNING. WHILE THERE IS AN
EXPANSIVE AREA OF STRATIFORM PRECIP AHEAD OF THIS FEATURE...IT
SHOULD DRY/ERODE SOME AS IT PROGRESSES EAST. BECAUSE OF THE CLOUD
COVER AND PERHAPS LIGHT RAIN...IT APPEARS THERE WILL BE LITTLE
OPPORTUNITY FOR THE ATMOSPHERE TO DESTABILIZE TODAY THOUGH THERE
WILL BE SOME PERSISTENT/FESTERING EMBEDDED CONVECTION ASSOCIATED
WITH THE MCV. WINDS APPEAR TO GO LIGHT AND VARIABLE TONIGHT...AND
NAM GUIDANCE AS WELL AS LAV POINT TO FOG/BR AND IFR CIGS DEVELOPING
OVERNIGHT. WILL NOT MENTION YET IN TAFS TO WAIT AND SEE HOW THE REST
OF THE DAY EVOLVES AND IF THERE IS ANY SIGNIFICANT DRYING THIS
AFTERNOON/EVENING.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* MEDIUM CONFIDENCE IN A LULL IN PRECIP/TSRA MID MORNING TO EARLY
AFTERNOON.
* LOW CONFIDENCE IN EVOLUTION OF MCV AND RESULTING PRECIP/TSRA
CHANCES THIS AFTERNOON.
* LOW TO MEDIUM CONFIDENCE IN WIND TRENDS.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...VFR.
FRIDAY THROUGH SATURDAY...PERIODIC CHANCES OF TSRA.
SATURDAY THROUGH MONDAY...PERIODIC CHANCES OF SHRA.
TUESDAY...CHC TSRA.
BMD
&&
.MARINE...
150 AM CDT
ELONGATED SFC LOW PRESSURE TROUGH OVER THE MID-UPPER MISSOURI
VALLEY WILL MOVE SLOWLY EAST TODAY...WITH VARYING MODEL FORECASTS
DEVELOPING A WEAK SURFACE LOW PRESSURE WAVE IN THE VICINITY OF
NORTHERN IL/IND OR SOUTHERN LAKE MICHIGAN BY THIS EVENING. SOUTH
TO SOUTHEAST WINDS SHOULD DIMINISH IN SPEED AS THE GRADIENT
WEAKENS WITH THE APPROACH OF THE TROUGH THIS AFTERNOON...WITH LAKE
BREEZE ESPECIALLY ALONG THE WESTERN SHORE. THUNDERSTORMS WILL BE
POSSIBLE ESPECIALLY OVER THE SOUTHERN HALF OF THE LAKE...WHICH MAY
RESULT IN SOME LOCALLY STRONGER WINDS. WINDS MAY BECOME SOMEWHAT
VARIABLE AT 10 KT OR LESS TONIGHT AS THE SURFACE TROUGH/COLD FRONT
MOVE SLOWLY ACROSS THE LAKE...EVENTUALLY TAKING ON A WEST-
NORTHWEST DIRECTION THURSDAY AS THE TROUGH MOVES OFF TO THE EAST.
SPEEDS SHOULD REMAIN GENERALLY LIGHT HOWEVER...WITH A RELATIVELY
WEAK GRADIENT INTO FRIDAY.
WEAK HIGH PRESSURE RIDGING WILL DEVELOP SOUTHEAST ACROSS THE
NORTHERN AND CENTRAL HIGH PLAINS INTO THE WEEKEND...WHILE THE LOW
PRESSURE WAVE EVENTUALLY DEEPENS EAST OF THE LAKES. THIS WILL
MAINTAIN A PROLONGED PERIOD OF NORTH-NORTHWEST FLOW ACROSS LAKE
MICHIGAN...THOUGH AGAIN WITH SPEEDS GENERALLY 15 KT OR LESS THROUGH
THE PERIOD.
OTHERWISE...IN THE NEAR TERM SOME PATCHY DENSE FOG WILL LINGER
ACROSS THE NORTHERN PART OF THE LAKE THIS MORNING.
RATZER
&&
.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 WEDNESDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 7
PM WEDNESDAY.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
731 AM EDT WED JUN 26 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 338 AM EDT WED JUN 26 2013
A SHORTWAVE CURRENTLY OVER THE DAKOTAS IS PRODUCING A LINE OF
THUNDERSTORMS ALONG THE SD/MN AND ND/MN BORDERS. THUNDERSTORMS
ACTIVITY HAS BEEN WANING OVER THE LAST COUPLE OF HOURS...BUT
WIDESPREAD PRECIP IS STILL OCCURRING. THIS SHORTWAVE WILL MOVE OVER
THE CWA THROUGH THE END OF THE SHORT TERM /12 THU/. CONTINUED TO
SHOW POPS ALONG AND AHEAD OF THE SHORTWAVE GIVEN EXTENT OF CURRENT
ACTIVITY. THERE IS AN OUTSIDE CHANCE AT A STRONGER STORM OR TWO
TODAY...WITH SOME STRONGER WINDS AND SMALL HAIL...GIVEN AROUND
1000J/KG OF CAPE...WEAK SHEAR AND A GOOD AMOUNT OF DRY AIR IN
FORECAST SOUNDINGS.
EXPECT HIGHS FROM THE UPPER 60S RIGHT ALONG LAKE SUPERIOR TO THE MID
80S INTERIOR. TONIGHT EXPECT LOWS IN THE 50S AND 60S.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 338 AM EDT WED JUN 26 2013
NAM SHOWS A 500 MB RIDGE OVER THE ROCKIES WITH TROUGHING IN THE
EASTERN U.S. 12Z THU. THE 500 MB RIDGE AMPLIFIES THIS PERIOD WITH
TROUGHING DIGGING IN THE EASTERN HALF OF THE U.S. NAM KEEPS SOME
850-500 MB Q-VECTOR CONVERGENCE OVER THE AREA 12Z THU ONWARD THROUGH
THE REST OF THIS FORECAST PERIOD WITH SOME MOISTURE AROUND. WILL
CONTINUE WITH THE SLIGHT CHANCE TO CHANCE POPS FOR THIS PERIOD. DOES
NOT LOOK LIKE A TOTAL WASHOUT AND CONVECTION WILL BE SCATTERED AT
BEST. OTHERWISE...DID NOT MAKE TOO MANY CHANGES TO THE GOING
FORECAST EXCEPT DID WARM TEMPERATURES UP A BIT ON THU AS 850 MB
TEMPERATURES OF 16C MIXED DOWN TO THE SFC GIVES ME HIGH IN THE LOWER
TO MID 80S. COLDER AIR ARRIVES FOR FRI THEN.
IN THE EXTENDED...A STRONG 500 MB RIDGE SETS UP IN THE ROCKIES
LEADING TO A HEAT WAVE IN THE WESTERN U.S. 12Z SAT WHILE A DEEP 500
MB TROUGH DIGS INTO THE EASTERN U.S. THE 500 MB PATTERN CHANGES VERY
LITTLE IN THE EXTENDED WITH THE TROUGH REMAINING OVER THE UPPER
GREAT LAKES REGION THROUGH TUE WITH PATTERN AMPLIFICATION. WHAT THIS
MEANS IS HEAT IN THE WESTERN U.S. AND COLDER THAN NORMAL
TEMPERATURES OVER THE AREA FOR AN EXTENDED PERIOD OF TIME. AFTER
SAT...LOOKS DRY FOR THE EXTENDED PERIOD EVEN WITH TROUGHING OVERHEAD
AND SFC RIDGING. WILL GO DRY SAT NIGHT ONWARD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 730 AM EDT WED JUN 26 2013
THERE IS SOME LIGHT MORNING FOG AT SAW /AND OCCASIONALLY AT
IWD/...BUT THIS FOG SHOULD BURN OFF QUICKLY. OTHERWISE...EXPECT VFR
CONDITIONS THROUGH AT LEAST MID AFTN. APPROACHING DISTURBANCE SHOULD
BRING SHRA/SCT TSRA INTO UPPER MI LATER THIS AFTN. INCLUDED
SHRA/VCTS AND MVFR CONDITIONS AT KIWD/KCMX LATE AFTN/EARLY EVENING
AND AT KSAW MID TO LATE EVENING. SHRA/SCT TSRA SHOULD BE IN THE AREA
FOR SEVERAL HRS. PROVIDED RAIN DOES OCCUR AT KCMX...CONDITIONS MAY
FALL TO IFR OR LWR ONCE PCPN ENDS THIS EVENING AS WINDS SHOULD HAVE
SOME UPSLOPE COMPONENT OFF THE LAKE. FOLLOWED HRRR MORE CLOSELY FOR
PRECIP TIMING THIS AFTERNOON/EVENING AS IT HAS BEEN PERFORMING
FAIRLY WELL WITH CONVECTION.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 338 AM EDT WED JUN 26 2013
OVERALL...WINDS ARE EXPECTED TO BE BELOW 20KTS THROUGH THE PERIOD AS
THE PRESSURE PATTERN REMAINS FAIRLY WEAK ACROSS THE AREA. WITH THE
WARM MOIST AIR OVER THE UPPER GREAT LAKES...WILL CONTINUE TO MENTION
PATCHY/AREAS OF FOG THROUGH TONIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...TITUS
LONG TERM...07
AVIATION...TITUS
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS DULUTH MN
1045 AM CDT WED JUN 26 2013
.UPDATE...
THE FOCUS FOR THIS UPDATE IS THE POTENTIAL OF SHOWERS AND
THUNDERSTORMS THROUGH THIS EVENING. THE ONLY REMAINING SHOWERS AND
STORMS AT THE TIME OF THIS UPDATE ARE NEAR A VORTEX MOVING
NORTHEAST NEAR IN NORTHERN ST. LOUIS COUNTY. REDEVELOPMENT ALONG
AND AHEAD OF TROUGH OF LOW PRESSURE MOVING THROUGH THE NORTHLAND
TODAY IS LIKELY...AT LEAST IN NW WISCONSIN AND THE MINNESOTA
ARROWHEAD. THE HRRR HAS BEEN CONSISTENTLY INDICATING A BAND OF
STORMS FORMING IN NW WISCONSIN BY EARLY THIS AFTERNOON AND EXITING
MID TO LATE THIS AFTERNOON. I ALTERED PCPN CHANCES TO REFLECT THE
HIGHEST CHANCES ACROSS THE EASTERN FORECAST AREA...WHILE LOWERED
CHANCES ACROSS THE WEST. WHILE THERE SHOULD BE A GENERAL
DECREASING CHANCE OF PCPN FROM WEST TO EAST THIS AFTERNOON INTO
THIS EVENING...SOME MODELS ARE INDICATING SOME SHOWERS AND STORMS
MOVING INTO THE WESTERN FORECAST AREA FROM NW MINNESOTA THIS
EVENING AND OVERNIGHT...SO I KEPT LOW CHANCES OVER JUST ABOUT ALL
OF THE FORECAST AREA THROUGH AT LEAST THIS EVENING. IT STILL
APPEARS WE COULD SEE SOME STRONG...MAYBE SEVERE STORMS...ACROSS NW
WISCONSIN. WHILE THERE MAY BE LOTS OF CAPE...WITH THE NAM12
INDICATING AT LEAST 4000 J/KG OF MOST UNSTABLE CAPE ALONG THE CAPE
AXIS...THE LIMITING FACTOR FOR SEVERE WEATHER WILL LIKELY BE WIND
SHEAR. THE NAM12 IS INDICATING LOW BULK SHEAR...LESS THAN 20 KNOTS
FOR 0-6KM...ALONG THE CAPE AXIS. HOWEVER...WE WILL NEED TO WATCH
CLOSELY FOR DEVELOPMENT AND SEE IF THE NAM12 WIND SHEAR HOLDS
TRUE. IF THERE IS MORE WIND SHEAR THAN THE NAM12 SUGGESTS...THEN
SOME STORMS COULD MORE EASILY BECOME SEVERE.
AS FAR AS TEMPERATURES TODAY...THE LATEST MOS GUIDANCE IS MUCH
WARMER IN SOME AREAS COMPARED TO THE PREVIOUS FORECAST. I INCREASED
TEMPERATURES BY UP TO SEVERAL DEGREES...NOTABLE ACROSS INLAND NW
WISCONSIN.
&&
.PREV DISCUSSION... /ISSUED 659 AM CDT WED JUN 26 2013/
AVIATION...
BAND OF WEAKENING CONVECTION CURRENTLY SWEEPING ACROSS THE
TERMINALS THIS MORNING. LINGERING STORMS BRINGING IFR TO MVFR CIGS
AND VSBYS AT THEY MOVE THROUGH EACH LOCATION. KHYR...WHICH HAS
BEEN IN THE CLEAR ALL NIGHT HAS DEVELOPED SOME MVFR FOG WHICH
SHOULD CLEAR BY 13Z. KDLH ALSO DEVELOPED SOME EARLY MORNING
FOG...WHICH SHOULD ALSO CLEAR IN NEXT COUPLE HOURS. ADDITIONAL
THUNDERSTORM DEVELOPMENT IS EXPECTED THIS AFTERNOON...MAINLY FOR
KINL...KHIB...KDLH AND KHYR. TIMING AND LOCATIONS UNCERTAIN SO
HAVE GONE WITH ONLY VCTS FOR NOW...BUT WILL HAVE TO REFINE WITH
LATER ISSUANCES. BY LATE AFTERNOON WEAK COLD FRONT TO MOVE THROUGH
THE AREA AND TURN WINDS TO WEST...ALSO ENDING TSRA CHANCES. LE
PREV DISCUSSION... /ISSUED 316 AM CDT WED JUN 26 2013/
SHORT TERM...SHORT TERM CONCERNS IS MOVEMENT OF THUNDERSTORM
COMPLEX IN NW MN THIS MORNING AND EFFECT ON FORECAST AREA. SECOND
CONCERN IS TSTM CHANCES.
CURRENT SURFACE ANALYSIS INDICATES AREA OF THUNDERSTORMS ACROSS NW
MN MOVING EAST-NORTHEAST. CAPES RANGE FROM 2500-4000 WITH THE
STORMS WITH THE STRONGEST STORMS JUST EAST OF FARGO. SHEAR IS
WEAKER TOWARD THE WESTERN AREAS OF THE FORECAST AREA BUT CAPES ARE
STILL ON THE HIGH SIDE ALONG WITH PLENTY OF MOISTURE. THE PRECIP
AREA HAS STARTED TO CLIP NW KOOCHCHING COUNTY AND WILL SPREAD EAST
EARLY THIS MORNING. THE PRECIP WILL DECREASE IN INTENSITY AND
COVERAGE AS IT MOVES THROUGH NE MN.
THE NEXT CONCERN FOR THE SHORT TERM IS THUNDERSTORM DEVELOPMENT
THIS AFTERNOON. THERE WILL BE SOME DEBRIS CLOUDS LEFT OVER FROM
THIS MORNING`S STORMS ACROSS NW MN. THE QUESTION FOR THE FORECAST
IS HOW MUCH SUN WILL BE SEEN LATE THIS MORNING AND THIS AFTERNOON.
BASED ON CURRENT TRENDS...THERE COULD BE SOME SUN THIS AFTERNOON
ACROSS EASTERN PORTIONS OF NE MN AND ALL NW WI. THIS WILL INCREASE
THE INSTABILITY THIS AFTERNOON OVER THAT REGION SO WILL KEEP
CURRENT POPS FOR TSTMS. SPC HAS THE SOUTHERN TIER OF NW WI
COUNTIES IN A SLIGHT RISK AREA FOR THIS AFTERNOON AND TONIGHT.
WEAK HIGH PRESSURE WILL BUILD INTO THE WESTERN PORTION OF MN AREA
TONIGHT ENDING THE PRECIP TONIGHT AND WEDNESDAY. THE ONLY
EXCEPTION WILL BE OVER THE ARROWHEAD WHERE THE TROUGH WILL KEEP
THE POSSIBILITY OF THUNDERSTORMS ACROSS THAT REGION THROUGH
THURSDAY.
LONG TERM...THURSDAY NIGHT THROUGH TUESDAY
THURSDAY NIGHT AND FRIDAY WE WILL HAVE A STATIONARY FRONT DRAPED
ACROSS THE ARROWHEAD REGION. THIS WILL BE ASSOCIATED WITH SOME
CHANNELED VORT MAXES IN THE STRONG NORTHWEST FLOW OVER THE
REGION...ON THE BACK SIDE OF THE UPPER LEVEL TROUGH OVER THE EAST
COAST AND THE STRONG RIDGE OVER THE ROCKIES. THIS WARRANTS SOME
HIGH CHANCE TO LOW END LIKELY POPS OVER THE ARROWHEAD REGION
THURSDAY NIGHT AND FRIDAY...ALONG WITH COOLER FRIDAY HIGHS IN THE
LOW 70S. ELSEWHERE HIGHS SHOULD RISE INTO THE MID TO UPPER 70S.
FRIDAY NIGHT AND SATURDAY THE FRONT IS PUSHED SOUTH AS A COLD FRONT
ALONG WITH A MORE VIGOROUS SHORTWAVE THAT DIGS DOWN ACROSS MN AND
WI. THIS SHIFTS OUR POPS SOUTH ACROSS THE REGION...HAVE HAVE PUT
MAINLY CHANCE POPS THROUGH THE PERIOD. SATURDAY LOOKS COOLER WITH
HIGHS ONLY IN THE LOW TO MID 70S...DEPENDING ON HOW MUCH SUNSHINE
CAN GET THROUGH.
SATURDAY NIGHT THROUGH SUNDAY AND INTO MONDAY WE MOVE INTO A DRY
PERIOD AS THE SHORTWAVE THAT MOVED THROUGH ON SATURDAY DIGS SOUTH
AND LEAVES US WITH SOME RIDGING ALOFT AND WEAK RIDGING AT THE
SURFACE AS WELL. THE SHORTWAVE EVENTUALLY CUTS OFF OVER THE DEEP
SOUTH STATES...AND TOGETHER WITH THE RIDGE OUT WEST REALLY SLOWS
DOWN OUR UPPER LEVEL PATTERN. THUS...WHILE I DO HAVE SOME SMALL
CHANCE POPS OUT FOR LATER MONDAY THROUGH TUESDAY...THEY ARE PRETTY
MINOR AND CONFIDENCE IS NOT TERRIBLY HIGH. HIGHS SHOULD RISE UP
INTO THE UPPER 70S TO NEAR 80.
&&
.POINT TEMPS/POPS...
DLH 80 59 80 57 / 50 30 40 10
INL 82 60 79 58 / 70 30 40 20
BRD 86 62 81 60 / 30 20 10 10
HYR 86 61 80 57 / 60 40 40 10
ASX 84 56 76 56 / 50 50 30 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...GROCHOCINSKI
AREA FORECAST DISCUSSION
NWS PENDLETON OR
ISSUED BY NATIONAL WEATHER SERVICE SPOKANE WA
814 AM PDT WED JUN 26 2013
.SHORT TERM...
QUICK UPDATE TO THE FORECAST TO INCREASE CLOUDS AND CHANCES OF
PRECIPITATION FOR THIS AFTERNOON. SATELLITE IMAGERY SHOWS THE
PLUME OF PACIFIC MOISTURE STARTING TO BEND BACK TO THE NORTH AS
THE WESTERN US RIDGE BEGINS TO BUILD. A SHORT WAVE IN THIS
SOUTHWESTERLY FLOW IS CAUSING WARM ADVECTION WIDESPREAD CLOUDS TO
FORM OVER THE AREA. VISIBLE SATELLITE IMAGERY DOESN`T SHOW MUCH
HOPE OF SUNSHINE TODAY. THIS WILL LIMIT THE INSTABILITY OVER THE
AREA DESPITE THE ABUNDANT MOISTURE. THUS THERE`S NO THUNDER IN THE
FORECAST FOR NOW BUT WILL HAVE TO MONITOR THIS, ESPECIALLY OVER
CENTRAL OREGON WHERE THE SUN HAS THE BEST CHANCE OF BREAKING
THROUGH THE CLOUDS.
THE HRRR MODEL DOES SHOW SOME LIGHT SHOWERS ASSOCIATED WITH THIS
CLOUD BAND, EVEN OVER THE LOWER BASIN AREA. BUT ALL MODELS AGREE
ON A FAIRLY SHOWERY DAY OVER THE MOUNTAINS. SO I INCREASED
PRECIPITATION CHANCES OVER THE ENTIRE AREA FOR THIS AFTERNOON. RJ
&&
.AVIATION...12Z TAFS...VFR CONDITIONS WILL PREVAIL THROUGH WEDNESDAY
AND WEDNESDAY NIGHT AT ALL TAF SITES. THERE WILL BE ISOLATED TO
SCATTERED SHOWERS AS ANOTHER WEATHER DISTURBANCE MOVES ACROSS THE
REGION. HOWEVER...IT IS UNLIKELY THAT CONDITIONS WILL DROP TO MVFR
EXCEPT FOR VERY BRIEF TIMES AT KRDM AND/OR KBDN DUE TO LOWERED
CEILINGS AND/OR VISIBILITY IF A SHOWER OR A THUNDERSTORM MOVES
DIRECTLY OVER EITHER OF THOSE SITES. WINDS WILL REMAIN LIGHT AND
UNDER 15 KTS THROUGH TONIGHT...EXCEPT GUSTY AND ERRATIC NEAR ANY
SHOWERS OR THUNDERSTORMS THAT MAY DEVELOP. 88
&&
.PREV DISCUSSION... /ISSUED 317 AM PDT WED JUN 26 2013/
SHORT TERM...TODAY THROUGH THURSDAY NIGHT...ANIMATED WATER VAPOR
SATELLITE IMAGERY SHOWS A LARGE MID/UPPER LEVEL LOW PRESSURE SYSTEM
NEAR 49N/138W WITH AN UPPER LEVEL JET STREAM ON THE SOUTHERN FLANK
OF THE LOW FEEDING ASSOCIATED SUBTROPICAL MOISTURE TOWARD THE
PACIFIC NORTHWEST. WIND SPEEDS IN THE CORE OF THE JET STREAM AROUND
30000 FEET ARE 125-130 MPH WITH THE NOSE OF THE JET CURRENTLY
LOCATED SQUARELY OVER THE FORECAST AREA. SOUTHWEST FLOW ALOFT
ASSOCIATED WITH THE JET STREAM WILL STEER A DISTURBANCE NOW MAKING
LANDFALL ON THE OREGON COAST ACROSS THE REGION TODAY AND BRING
ISOLATED TO SCATTERED SHOWERS THROUGH THIS AFTERNOON TO THE
MOUNTAINS OF SE WASHINGTON AND NE OREGON, THE FOOTHILLS OF THE BLUE
MOUNTAINS, AND THE EAST SLOPES OF THE CASCADES. THE DISTURBANCE
EXITS INTO IDAHO/MONTANA THIS EVENING FOR DRY CONDITIONS AT LOWER
ELEVATIONS AND DECREASING POPS IN THE BLUE MOUNTAINS AND ALONG THE
CASCADE CRESTS TONIGHT. HEIGHT CONTOURS OF PRESSURE SURFACES IN THE
TROPOSPHERE BEGIN RISING ON THURSDAY INTO FRIDAY BY VIRTUE OF A
MID/UPPER LEVEL RIDGE OF HIGH PRESSURE THAT BUILDS OVER THE PACIFIC
NORTHWEST THROUGH THE WEEKEND WITH THE RIDGE AMPLIFICATION
CONTINUING DIRECTLY OVER THE FORECAST AREA INTO NEXT WEEK. SINKING
AIR ASSOCIATED WITH THE RIDGE WILL INITIATE A STRONG WARMING TREND
TODAY, WHICH WILL PERSIST OVER THE WEEKEND AND WELL INTO NEXT WEEK
THUS PRODUCING WELL ABOVE NORMAL HIGH TEMPERATURES EACH DAY. POLAN
LONG TERM...FRIDAY THROUGH WEDNESDAY...ALL MODELS ARE IN AGREEMENT
IN CONTINUING TO BUILD A STRONG RIDGE OF HIGH PRESSURE INTO THE
PACIFIC NORTHWEST FROM THE GREAT BASIN. CONFIDENCE OF THIS PATTERN
DEVELOPING IS INCREASING AS EACH MODEL RUN CONTINUES TO SHOW THE IT
DEVELOPING. THIS WILL RESULT IN A HEAT WAVE DURING THE EXTENDED
FORECAST PERIOD. EACH DAY WILL BECOME HOTTER THAN THE PREVIOUS FROM
FRIDAY THROUGH WEDNESDAY AS 850 MB TEMPERATURES BECOME WARMER EACH
DAY FROM THE PREVIOUS DAY AND THE CENTER OF THE HIGH PRESSURE RIDGE
BECOMING WELL ESTABLISHED OVER THE PACIFIC NORTHWEST. ON FRIDAY CAN
EXPECT HIGH TEMPERATURES TO CLIMB INTO THE LOWER TO MID 90S IN THE
LOWER ELEVATIONS...WITH UPPER 70S TO MID 80S IN THE MOUNTAINS. THE
WARMING TREND WILL CONTINUE THROUGH THE WEEKEND INTO EARLY NEXT
WEEK. BY TUESDAY 850 MB TEMPERATURES ARE INDICATING MAXIMUM SURFACE
TEMPERATURES TO BE WELL INTO THE MID 90S TO MID 100S...WITH MID 80S
TO MID 90S IN THE MOUNTAINS. THE GFS MODEL IS FORECASTING AN 850 MB
TEMPERATURE OF 31 OVER PENDLETON ON TUESDAY WHICH WHEN TRANSLATED TO
THE SURFACE IS A TEMPERATURE NEAR 110. HOWEVER...IT IS A BIT TOO
EARLY TO BELIEVE THE MODEL THAT FAR OUT IN TIME...BUT NEVERTHELESS
CONFIDENCE IS INCREASING THAT IT WILL BECOME DANGEROUSLY HOT BY
MONDAY THROUGH WEDNESDAY. THE HOT SURFACE TEMPERATURES WILL CREATE
STEEP LAPSE RATES. THERE MAY BE ENOUGH MID LEVEL MOISTURE AS WELL
SUCH THAT ISOLATED AFTERNOON AND EVENING THUNDERSTORMS COULD DEVELOP
BEGINNING FRIDAY AFTERNOON...MAINLY ALONG THE WASHINGTON CASCADES
AND THE EASTERN OREGON/SOUTHEAST WASHINGTON MOUNTAINS. 88
AVIATION...12Z TAFS...VFR CONDITIONS WILL PREVAIL THROUGH WEDNESDAY
AND WEDNESDAY NIGHT AT ALL TAF SITES. THERE WILL BE ISOLATED TO
SCATTERED SHOWERS AS ANOTHER WEATHER DISTURBANCE MOVES ACROSS THE
REGION. HOWEVER...IT IS UNLIKELY THAT CONDITIONS WILL DROP TO MVFR
EXCEPT FOR VERY BRIEF TIMES AT KRDM AND/OR KBDN DUE TO LOWERED
CEILINGS AND/OR VISIBILITY IF A SHOWER OR A THUNDERSTORM MOVES
DIRECTLY OVER EITHER OF THOSE SITES. WINDS WILL REMAIN LIGHT AND
UNDER 15 KTS THROUGH TONIGHT...EXCEPT GUSTY AND ERRATIC NEAR ANY
SHOWERS OR THUNDERSTORMS THAT MAY DEVELOP. 88
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 77 56 88 60 / 30 20 0 0
ALW 78 60 89 64 / 30 20 0 0
PSC 81 58 89 63 / 20 10 0 0
YKM 79 57 85 62 / 20 10 0 0
HRI 81 57 89 61 / 20 10 0 0
ELN 76 55 85 60 / 30 10 0 0
RDM 75 50 86 52 / 20 10 0 0
LGD 72 52 84 54 / 70 10 0 0
GCD 76 53 87 56 / 60 10 0 0
DLS 79 59 87 61 / 20 10 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
THREAT INDEX
TODAY : GREEN
THURSDAY : GREEN
FRIDAY : GREEN
GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES.
YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
99/99/99
AREA FORECAST DISCUSSION
NWS ALBANY NY
135 PM EDT WED JUN 26 2013
.SYNOPSIS...
MAINLY CLOUDY CONDITIONS WILL CONTINUE THROUGH THE
AFTERNOON AND INTO THE EVENING WITH SHOWERS AND THUNDERSTORMS. SOME
OF THE THUNDERSTORMS COULD PRODUCE HEAVY RAINFALL. A LOW PRESSURE
SYSTEM WILL BRING A WIDESPREAD HEAVY RAINFALL AND SOME THUNDERSTORMS
TO THE REGION LATE THURSDAY THROUGH FRIDAY. UNSETTLED WEATHER WILL
CONTINUE INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 135 PM EDT...VISIBLE SATELLITE IMAGERY SHOWS WIDESPREAD
CLOUDS ACROSS THE CWA EARLY THIS AFTERNOON. LOOKING AT KENX
RADAR...THERE CURRENTLY IS ONE BATCH OF MODERATE RAIN SHOWERS
ACROSS THE LAKE GEORGE AREA...WITH LOCALLY OVER AN INCH OF RAIN
ALREADY HAVING FALLEN FROM THIS ACTIVITY. MEANWHILE...THE
REMAINDER OF THE REGION IS FAIRLY QUIET...WITH JUST SOME SCT LIGHT
RAIN SHOWERS.
A WEAK SHORTWAVE WILL BE PASSING ACROSS THE REGION THIS AFTERNOON
INTO THIS EVENING...WHICH MAY ENHANCE THE CURRENT SHOWER/TSTM
ACTIVITY. THE 15Z HRRR SHOWS A BROKEN LINE OF SHOWERS AND
THUNDERSTORMS MOVING SOUTHEAST ACROSS CENTRAL AND SOUTHERN PARTS
OF THE CWA FOR THE LATE AFTN INTO THE EVENING HOURS.
WITH THE CLOUD COVER IN PLACE...INSTABILITY WILL BE LIMITED THIS
AFTERNOON. HOWEVER...PWATS REMAIN HIGH...WITH A READING AROUND
1.75 INCHES FOR ALBANY BASED ON THE 12Z KALY SOUNDING AND 12Z
BUFKIT MODEL SOUNDINGS FOR KALB. LATEST SFC OBS SHOW DEWPOINTS IN
THE UPPER 60S TO LOW 70S...SO ANY THUNDERSTORM WILL BE CAPABLE OF
HVY RAINFALL. THE SEVERE THREAT MAY BE LIMITED DUE TO CLOUD
COVER/LIMITED INSTABILITY...BUT SPC MAINTAINS A SLIGHT RISK OVER
MUCH OF THE REGION. THE MAIN THREAT TODAY IS PROBABLY HEAVY
RAINFALL AND POTENTIAL LOCALIZED FLOODING...ALTHOUGH A ROGUE
SEVERE WIND GUST OR MARGINAL SEVERE HAIL CANNOT TOTALLY BE RULED
OUT...ESP IF SOME BREAKS IN THE CLOUDS WERE TO OCCUR.
WITH THE CLOUDS IN PLACE...MAX TEMPS WILL BE HELD DOWN...ESP
COMPARED TO RECENT DAYS. MAX TEMPS IN THE UPPER 70S TO MID 80S ARE
EXPECTED...WITH THE WARMEST READINGS ACROSS THE SOUTHEASTERN PART
OF THE CWA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...THE SHOWERS AND THUNDERSTORMS SHOULD DIMINISH OVER THE
SRN PORTION QUICKLY EARLY THIS EVENING WITH A WEAK MICRO RIDGE
BUILDING IN OVER NY AND PA. THE SFC HIGH WILL NUDGE IN FROM SE
ONTARIO...AND THE ERN GREAT LAKES REGION. A PARTIAL CLEARING OVER
THE NRN PORTION OF THE FCST AREA WILL ALLOW PATCHY FOG TO FORM
AGAIN WITH LIGHT WINDS AND MOISTURE IN THE BOUNDARY LAYER. LOW
TEMPS IN THE LOWER TO MID 60S WILL BE COMMON...WITH PERHAPS SOME
U60S IN THE VALLEYS. WEAK WARM ADVECTION COMMENCES OVER THE SRN
TIER AHEAD OF A WARM FRONT/THERMAL TROUGH...AS A LOW PRESSURE
SYSTEM WITH STRONG SHORT-WAVE TROUGH APPROACHES FROM THE OHIO
VALLEY AND THE LOWER GREAT LAKES REGION TOWARDS 12Z/THU. THE
SHOWALTER VALUES LOWER TO -1C NEAR THE MID HUDSON VALLEY...SO A
SLIGHT OR LOW CHC OF SHOWERS AND THUNDERSTORMS WAS INCLUDED
TOWARDS DAYBREAK.
THU-THU NIGHT...ANOTHER ACTIVE STRETCH OF WX AS THE POTENT SHORT-
WAVE TROUGH SWINGS TOWARD THE REGION WITH A SFC CYCLONE LIFTING
NORTHWARD FROM PA INTO W-CNTRL NY IN THE AFTERNOON. THE ISENTROPIC
LIFT INCREASES AHEAD OF THE WARM FRONT FOR SHOWERS AND SCT
THUNDERSTORMS TO INCREASE FROM SOUTH TO NORTH DURING THE
AFTERNOON. THE PLACEMENT OF THE WARM SECTOR IS NEBULOUS
STILL...AND PERHAPS THE SRN MOST ZONES MAY GET INTO ONE BEFORE
SUNSET. THE AMOUNTS OF INSTABILITY LOOKS VARIABLE ON THE GUIDANCE
AND THE LOW-LEVEL JET DOES NOT CRANK UP UNTIL NIGHTFALL /30-40 KTS
AT H850/. THE GFS DOES SHOW A BRIEF PERIOD OF MLCAPES OF 500-1500
J/KG IN THE AFTERNOON OVER THE SRN MOST ZONES. AGREE WITH SPC THAT
5% WIND PROBABILITIES LOOK GOOD AT THIS POINT FOR A FEW STRONG TO
MAYBE SEVERE THUNDERSTORMS. THE QG LIFT STRENGTHENS ON THE NORTH
SIDE OF THE SFC WAVE AND AHEAD OF THE WARM FRONT. USED THE WEATHER
PHRASING AS RAIN HEAVY AT TIMES WITH A CHC OF THUNDERSTORMS WITH
SHOWALTER VALUES OF 0 TO -2C...ESPECIALLY AT NIGHT.
PWATS WILL BE RUNNING A FEW STANDARD DEVIATIONS ABOVE NORMAL FOR
SOME VERY HEAVY RAINFALL POSSIBLE. A FLASH FLOOD OR FLOOD WATCH MAY
BE NEEDED LATER IN TIME. THE WPC QPF WAS ACCEPTED WITH 1-2+ INCHES
OF RAINFALL POSSIBLE THU-THU NIGHT OVER THE FCST AREA. THE HEAVIEST
RAINFALL LOOKS LIKE IT WILL BE OVER THE SRN DACKS REGION AND MOHAWK
VALLEY. WPC ALSO HAS A SLIGHT RISK OF FLASH FLOODING FOR THE FCST
AREA. THE ECMWF AND GFS QPF LOOK CLOSER TO WPC THAN THE NAM. THE
HEAVIEST RAIN AXIS APPEARS IT WILL BE OVER W-CNTRL NY. NO POINTS ARE
FORECASTED TO FLOOD ON THE MAIN STEM RIVERS AT THIS TIME.
CATEGORICAL AND LIKELY POPS WERE USED IN THE PM AND NIGHT TIME
PERIOD. MAX TEMPS IN THE 70S TO L80S WILL BE COMMON WITH LOWS IN THE
60S.
FRIDAY...FOLLOWED THE GFS/ECMWF WHERE A DRY SLOT TO THE SYSTEM MAY
SHUT THE RAINFALL OFF IN THE LATE MORNING...ESPECIALLY OVER THE
SRN TWO THIRDS OF THE FCST AREA. SMALL AMOUNTS OF
INSTABILITY...AND POSSIBILITY OF A LITTLE SUN STILL WARRANTED A
CHANCE OF THUNDERSTORMS. THE SFC WAVE WILL BE OVER SRN QUEBEC
WITH A FRONTAL BOUNDARY STALLING NEAR THE REGION. ANOTHER IMPULSE
ROUNDING THE BASE OF THE TROUGH COULD REKINDLE THE SHOWERS IN THE
AFTERNOON. THE GFSMOS MAX TEMPS WERE FAVORED AGAIN.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
THE WEATHER PATTERN WILL BE A VERY HUMID AND UNSETTLED DURING THE
LONG TERM PERIOD. THE MEDIUM RANGE MODELS INDICATE THAT A DEEP TROF
WILL SET UP ACROSS THE MIDDLE OF THE COUNTRY WHILE A LARGE UPPER
LEVEL RIDGE WILL BUILD OVER THE WESTERN ATLANTIC OFF THE MID
ATLANTIC COAST. THIS WILL KEEP THE REGION IN A SOUTHWEST FLOW OF
VERY MOIST AIR THROUGH THE PERIOD WITH A STALLED FRONTAL BOUNDARY
SOMEWHERE ALONG THE EAST COAST. THIS SHOULD RESULT IN AT LEAST
SCATTERED SHOWERS AND TSTMS EACH DAY...WITH THE GREATEST COVERAGE
OCCURRING DURING THE AFTN AND EVENING. ALTHOUGH SOME SHORT WAVE
TROFS MAY EVENTUALLY RIDE ALONG THIS SOUTHWEST FLOW OF MOIST AIR AND
PROVIDE ADDITIONAL FOCUS TO THE CONVECTION/PCPN...MODELS ARE NOT
INDICATING ANY OBVIOUS SYSTEMS AT THIS TIME...SO PREFERRED TO KEEP
POPS IN THE CHANCE RANGE (40 TO 50 PERCENT) DURING THE ENTIRE LONG
TERM PERIOD AND LATER FORECAST CAN REFINE PERIOD WHERE POPS MAY NEED
TO BE HIGHER.
ALTHOUGH THIS TYPE OF PATTERN FREQUENTLY RESULTS IN VERY WARM OR HOT
TEMPS...FAIRLY WIDESPREAD CLOUD COVER AND OCNL PCPN WILL KEEP HIGH
TEMPS IN THE MID 70S TO LOWER 80S SATURDAY THRU TUESDAY. HOWEVER...
DEWPOINTS IN THE 60S WILL MAKE IT FEEL UNCOMFORTABLE. LOW TEMPS WILL
BE WARM WITH LOWS IN THE UPPER 50S AND 60S FRIDAY NIGHT THROUGH
MONDAY NIGHT.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
A WEAK SURFACE/UPPER LEVEL TROF WILL MOVE ACROSS THE TAF SITES INTO
THIS EVENING. AN AREA OF SHOWERS HAS BEEN AFFECTING KGFL WITH MVFR
CONDITIONS...AND AN MVFR CEILING IS AFFECTING KPSF. AN AREA OF
SHOWERS SHOULD EXIT THE KGFL AREA BETWEEN 19Z-21Z...WHILE LIGHTER
SHOWERS DEVELOP AND TRACK TOWARD KALB AND KPSF. THE SCATTERED
NATURE TO THE SHOWERS SUGGESTS PUTTING VCSH AT THOSE SITES THIS
AFTERNOON. SOME SCATTERED THUNDERSTORM ACTIVITY COULD DEVELOP
TOWARD KPOU BUT AGAIN SCATTERED NATURE SUGGESTS VCSH UNTIL ACTUAL
THUNDERSTORM DEVELOPMENT WHEN AMENDMENTS MAY BE NEEDED.
ALL SHOWER AND THUNDERSTORM ACTIVITY SHOULD END THIS EVENING AND
SOME CLEARING SHOULD TAKE PLACE...WITH JUST SCATTERED CLOUDS THIS
EVENING. FOG IS LIKELY TO DEVELOP AFTER MIDNIGHT AND CONTINUE
THROUGH ABOUT 14Z...WITH SOME LOW CEILINGS POTENTIALLY DEVELOPING
ALONG WITH THE FOG. ANY FOG AND LOW CLOUDS SHOULD LIFT BY 14Z...AND
VFR CONDITIONS SHOULD PREVAIL AT ALL THE SITES THROUGH THE REST OF
TOMORROW MORNING.
WINDS SHOULD BE LIGHT SOUTH TO SOUTHWEST THIS AFTERNOON...AND
NEARLY CALM TONIGHT. WINDS SHOULD BE VARIABLE TO LIGHT SOUTH AT 6
KT OR LESS TOMORROW MORNING.
OUTLOOK...
THU-FRI...VFR/MVFR. SHOWERS LIKELY W/CHC -TSRAS.
SAT-MON ...VFR/MVFR IN CHC -SHRAS/-TSRAS.
&&
.FIRE WEATHER...
ANOTHER DISTURBANCE TODAY WILL FOCUS ANOTHER
ROUND OF ISOLATED TO SCATTERED THUNDERSTORMS WITH WARM AND HUMID
CONDITIONS PREVAILING. SOME OF THE THUNDERSTORMS COULD BE STRONG TO
SEVERE WITH VERY HEAVY RAINFALL. A LOW PRESSURE SYSTEM WILL BRING A
WIDESPREAD POTENTIALLY HEAVY RAINFALL AND SOME STRONG THUNDERSTORMS
TO THE REGION THURSDAY THROUGH FRIDAY.
HIGH RH VALUES AND WET CONDITIONS WILL PERSIST FOR THE NEXT
SEVERAL DAYS...AND THEIR WILL BE NO FIRE WEATHER ISSUES.
&&
.HYDROLOGY...
THE UNSETTLED WEATHER CONTINUES...AS THE WEEK PROGRESSES WITH
A POTENTIAL POTENT STORM IMPACTING THE REGION LATE THURSDAY INTO
FRIDAY.
FIRST...THE SHOWERS AND THUNDERSTORMS WILL HAVE THE POTENTIAL TO
PRODUCE LOCALLY HEAVY RAINFALL TODAY. SOME TRAINING OF THE CELLS
WILL HAVE TO BE MONITORED THIS AFTERNOON INTO TONIGHT.
PONDING OF WATER ON ROADWAYS ALONG WITH MINOR FLOODING OF LOW LYING
AND POOR DRAINAGE AREAS IS EXPECTED WITH THE HEAVY RAINFALL. ALSO
SOME SMALL STREAMS...CREEKS...AND BROOKS MAY REACH BANKFULL OR EVEN
FLOODING QUICKLY ESPECIALLY IF STORMS MOVE OVER THE SAME AREA
REPEATEDLY.
THE RAINFALL FROM THE LOW PRESSURE SYSTEM AND ITS WARM FRONT
THURSDAY INTO FRIDAY MORNING COULD PRODUCE 1 TO 2 INCHES OF
RAINFALL WITH LOCALLY HIGHER AMOUNTS. THE WPC QPF WAS USED IN THIS
TIME FRAME. A FLASH FLOOD WATCH OR FLOOD WATCH MAY BE NEEDED IF
THE POTENTIAL FOR WIDESPREAD FLOODING LOOKS LIKELY.
MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED FRIDAY THROUGH THE
WEEKEND WHICH WILL ALLOW SOILS TO BECOME MORE SATURATED AND
INCREASES THE POTENTIAL RISK OF FLOODING.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS/NAS/WASULA
NEAR TERM...FRUGIS
SHORT TERM...WASULA
LONG TERM...SNYDER
AVIATION...NAS
FIRE WEATHER...WASULA
HYDROLOGY...BGM/WASULA
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
253 PM CDT WED JUN 26 2013
.DISCUSSION...
308 AM CDT
THE LATEST IN A SERIES OF WEAK SHORTWAVES IN QUASI-ZONAL SOUTHERN
STREAM FLOW HAS BEEN SUPPORTING WIDESPREAD CONVECTION AS IT MOVES
TOWARD THE AREA EARLY THIS MORNING. GRADUALLY OVER THE NEXT TWO
DAYS THE LARGE SCALE PATTERN WILL BE AMPLIFYING INTO A BROAD
ANTICYCLONE ACROSS THE WESTERN CONUS AND A DEEPENING LONGWAVE TROUGH
OVER THE EASTERN STATES. THE WARM HUMID CONDITIONS OF RECENT DAYS
WILL BE REPLACED BY COOL HUMID CONDITIONS BY THE WEEKEND...WHICH
THEN WILL PERSIST INTO NEXT WEEK.
FIRST QUESTION CONCERNS PRECIPITATION TRENDS FOR TODAY. AT 08Z THE
EXISTING AREAS OF CONVECTION ACROSS NORTHEAST IOWA INTO NORTHERN
ILLINOIS WERE LOCATED ALONG FAVORABLE GRADIENTS OF MOISTURE
TRANSPORT ON THE LEADING EDGE OF THE LOW LEVEL JET...AND UNDER A
WEAK SHORTWAVE DEPICTED IN THE RAP MODEL AND VWP OBS AT 850 AND 700
MB. THIS ACTIVITY SHOULD BE MOVING ACROSS NORTHEASTERN ILLINOIS
DURING THE PREDAWN HOURS BUT THEN BEGINNING TO WEAKEN AS THE
LLJ VEERS AND ADJUSTS ITS FOCUS MORE TOWARD CENTRAL AND SOUTHERN
ILLINOIS.
IF THIS ACTIVITY DOES DISSIPATE AS EXPECTED TOWARD MORNING...THE
PROSPECTS OF REDEVELOPMENT TODAY ARE SOMEWHAT UNCERTAIN DESPITE
MODEL QPF SOLUTIONS TO THE CONTRARY. LINGERING MORNING SHOWERS AND
THEN SCATTERED TSRA LATER ARE DEFINITELY NOT OUT OF THE QUESTION
LOCALLY BUT THE MORE FAVORABLE AREAS OF MOISTURE ADVECTION AND STEEP
MID LEVEL LAPSE RATES ARE FARTHER SOUTH TOWARD CENTRAL ILLINOIS AND
FARTHER NORTH ALONG THE WI/MN STATE LINE.
DESPITE THE APPROACH OF A SURFACE/850 FRONTAL ZONE...THE UPPER LEVEL
WAVES APPEAR TO BE SOMEWHAT OUT OF SYNC AND MORE
PROGRESSIVE...LEAVING THE LOWER LEVEL FEATURES UNDER AREAS OF RISING
HEIGHTS ALOFT. IN THE 0530Z SPC DAY 1 OUTLOOK THE SLIGHT RISK
EXTENDS NORTHWEST TOWARD MSP AND THEN WELL SOUTH AND EAST THROUGH
THE TENNESSEE AND OHIO VALLEYS. WOULD NOT BE SURPRISED TO SEE THIS
SPLIT IN LATER UPDATES...WITH THE THUMB TO OUR NORTHWEST SEPARATED
FROM THE AREA TO OUR SOUTH. BUT THAT WOULD BE CUTTING IT PRETTY
FINE GIVEN THE OVERALL UNCERTAINTY WITH THIS SITUATION.
LONG STORY SHORT...FOR TODAY THE PLAN WILL BE TO LOWER POPS INTO THE
CHANCE CATEGORY BY AFTERNOON FOR MOST OF THE AREA BUT KEEP IN MIND
THE PWATS APPROACHING TWO INCHES AND THEREFORE MAINTAIN THE FLASH
FLOOD WATCH AND THE MENTION OF TSRA.
AFTER TODAY THE SITUATION BECOMES ONLY SLIGHTLY MORE CLEAR BUT OF
SEEMINGLY LESSER IMPACT.
AMPLIFICATION OF THE LARGE SCALE FLOW WILL BEGIN TO INFLUENCE THE
LOCAL AREA BY TONIGHT INTO THURSDAY AFTER THE SURFACE TROUGH PUSHES
THROUGH THE AREA AND WINDS AT ALL LEVELS TURN TO THE NORTHWEST. LOW
LEVEL WARMTH AND HUMIDITY DO NOT REALLY DEPART UNTIL FRIDAY WHEN THE
EXPANDING EASTERN TROUGH PUSHES THE UPPER JET SOUTH OF THE AREA AND
USHERS IN SLIGHTLY DRIER BUT MILDER AIR.
WITH ONLY MARGINAL LAPSE RATES AND HEIGHTS ALOFT CONTINUING TO
INCREASE...NEITHER THURSDAY NOR FRIDAY LOOK PARTICULARLY FAVORABLE
FOR WIDESPREAD PRECIPITATION. AS MENTIONED IN AN EARLIER
DISCUSSION...IT WOULD NOT TAKE MUCH OF A SHORTWAVE IN THE UPPER FLOW
TO SUPPORT AN AFTERNOON SHOWER...SO WILL CONTINUE TO CARRY SLIGHT
CHANCE POPS ON BOTH DAYS.
BY THE WEEKEND THE CONVECTIVE INSTABILITY APPEARS TO HAVE
DECREASED...BUT THE PRESENCE OF BOTH A SURFACE AND UPPER LEVEL
TROUGH DROPPING SOUTH ACROSS THE AREA WILL STILL SUPPORT LARGE SCALE
LIFT...PRIMARILY TO THE SOUTH ON SUNDAY. PRECIP CHANCES FINALLY
DECREASE BY EARLY NEXT WEEK AS THE SURFACE AND UPPER SUPPORT
DIMINISH...BUT UNSEASONABLY COOL AIR REMAINS IN PLACE WITH CONTINUED
NORTH TO NORTHEASTERLY WINDS.
LENNING
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* UNCERTAINTIES REMAIN WITH PRECISE WIND DIRECTION THIS AFTERNOON
* MVFR VSBY IN BR POSSIBLE LATE TONIGHT/VERY EARLY THURS AM
* CHANCE OF TSRA AGAIN THURS PM
IZZI
//DISCUSSION...UPDATED 20Z...
WIND DIRECTIONS CONTINUE TO BE A CHALLENGE THIS AFTERNOON WITH
SMALL MESOLOW THAT WAS OVER NW IL PERSISTING SURPRISINGING LONG
AND NOW PUSHING INTO NE IL. WINDS HAVE BEEN VEERING AROUND TO A
MORE WESTERLY DIRECTION AND WITH LATEST AMENDMENTS HAVE ADJUSTED
THE FORECAST ACCORDINGLY. DON`T SEE A GOOD REASON FOR WINDS TO
BACK TO MORE SOUTHERLY AND IF ANYTHING GO MORE WESTERLY THIS
AFTERNOON BEFORE DIMINSHING THIS EVENING.
IZZI
UPDATED 18Z...
OVERNIGHT AND MORNING THUNDERSTORMS HAVE FINALLY DIMINISHED
LEAVING A LARGE POOL OF STABLE AIR OVER THE REGION WHICH SHOULD
RESULT IN MINIMAL THREAT ADDITIONAL CONVECTION DEVELOPING THIS
AFTERNOON OR TONIGHT. WINDS HAVE RAPIDLY SWUNG AROUND TO THE S/SSW
AND WITH FURTHER HEATING/MIXING WOULD EXPECT THE SOUTHERLY WINDS
TO CONTINUE THROUGH THE AFTERNOON WITH ONLY A MINIMAL THREAT OF
WINDS BACKING TO EASTERLY DIRECTION AFTER TODAY. WINDS SHOULD GO
LIGHT/VARIABLE TONIGHT AND COULD ACTUALLY SEE SOME PATCY GROUND
FOG DEVELOP LATE TONIGHT...PARTICULARLY IN THE OUTLYING AREAS. AN
UPPER LEVEL DISTURBANCE IS PROGGED TO SWING THROUGH THE REGION
DURING THE AFTERNOON RESULTING IN SCT`D TSRA DEVELOPING...SOME
POSSIBLY STRONG TO SEVERE.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* LOW-MEDIUM CONFIDENCE IN WIND DIRECTION REMAINDER OF THIS
AFTERNOON
* MEDIUM-HIGH CONFIDENCE IN DRY WEATHER THROUGH THURS MORNING
* LOW-MEDIUM CONFIDENCE IN TSRA CHANCES THURS AFTERNOON
* HIGH CONFIDENCE IN OTHER ELEMENTS
IZZI
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...VFR.
FRIDAY THROUGH SATURDAY...PERIODIC CHANCES OF TSRA.
SATURDAY THROUGH MONDAY...PERIODIC CHANCES OF SHRA.
TUESDAY...CHC TSRA.
BMD
&&
.MARINE...
150 AM CDT
ELONGATED SFC LOW PRESSURE TROUGH OVER THE MID-UPPER MISSOURI
VALLEY WILL MOVE SLOWLY EAST TODAY...WITH VARYING MODEL FORECASTS
DEVELOPING A WEAK SURFACE LOW PRESSURE WAVE IN THE VICINITY OF
NORTHERN IL/IND OR SOUTHERN LAKE MICHIGAN BY THIS EVENING. SOUTH
TO SOUTHEAST WINDS SHOULD DIMINISH IN SPEED AS THE GRADIENT
WEAKENS WITH THE APPROACH OF THE TROUGH THIS AFTERNOON...WITH LAKE
BREEZE ESPECIALLY ALONG THE WESTERN SHORE. THUNDERSTORMS WILL BE
POSSIBLE ESPECIALLY OVER THE SOUTHERN HALF OF THE LAKE...WHICH MAY
RESULT IN SOME LOCALLY STRONGER WINDS. WINDS MAY BECOME SOMEWHAT
VARIABLE AT 10 KT OR LESS TONIGHT AS THE SURFACE TROUGH/COLD FRONT
MOVE SLOWLY ACROSS THE LAKE...EVENTUALLY TAKING ON A WEST-
NORTHWEST DIRECTION THURSDAY AS THE TROUGH MOVES OFF TO THE EAST.
SPEEDS SHOULD REMAIN GENERALLY LIGHT HOWEVER...WITH A RELATIVELY
WEAK GRADIENT INTO FRIDAY.
WEAK HIGH PRESSURE RIDGING WILL DEVELOP SOUTHEAST ACROSS THE
NORTHERN AND CENTRAL HIGH PLAINS INTO THE WEEKEND...WHILE THE LOW
PRESSURE WAVE EVENTUALLY DEEPENS EAST OF THE LAKES. THIS WILL
MAINTAIN A PROLONGED PERIOD OF NORTH-NORTHWEST FLOW ACROSS LAKE
MICHIGAN...THOUGH AGAIN WITH SPEEDS GENERALLY 15 KT OR LESS THROUGH
THE PERIOD.
OTHERWISE...IN THE NEAR TERM SOME PATCHY DENSE FOG WILL LINGER
ACROSS THE NORTHERN PART OF THE LAKE THIS MORNING.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ023-ILZ033-ILZ039 UNTIL 7 PM WEDNESDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 7
PM WEDNESDAY.
LM...NONE.
&&
$$
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
1239 PM CDT WED JUN 26 2013
.DISCUSSION...
308 AM CDT
THE LATEST IN A SERIES OF WEAK SHORTWAVES IN QUASI-ZONAL SOUTHERN
STREAM FLOW HAS BEEN SUPPORTING WIDESPREAD CONVECTION AS IT MOVES
TOWARD THE AREA EARLY THIS MORNING. GRADUALLY OVER THE NEXT TWO
DAYS THE LARGE SCALE PATTERN WILL BE AMPLIFYING INTO A BROAD
ANTICYCLONE ACROSS THE WESTERN CONUS AND A DEEPENING LONGWAVE TROUGH
OVER THE EASTERN STATES. THE WARM HUMID CONDITIONS OF RECENT DAYS
WILL BE REPLACED BY COOL HUMID CONDITIONS BY THE WEEKEND...WHICH
THEN WILL PERSIST INTO NEXT WEEK.
FIRST QUESTION CONCERNS PRECIPITATION TRENDS FOR TODAY. AT 08Z THE
EXISTING AREAS OF CONVECTION ACROSS NORTHEAST IOWA INTO NORTHERN
ILLINOIS WERE LOCATED ALONG FAVORABLE GRADIENTS OF MOISTURE
TRANSPORT ON THE LEADING EDGE OF THE LOW LEVEL JET...AND UNDER A
WEAK SHORTWAVE DEPICTED IN THE RAP MODEL AND VWP OBS AT 850 AND 700
MB. THIS ACTIVITY SHOULD BE MOVING ACROSS NORTHEASTERN ILLINOIS
DURING THE PREDAWN HOURS BUT THEN BEGINNING TO WEAKEN AS THE
LLJ VEERS AND ADJUSTS ITS FOCUS MORE TOWARD CENTRAL AND SOUTHERN
ILLINOIS.
IF THIS ACTIVITY DOES DISSIPATE AS EXPECTED TOWARD MORNING...THE
PROSPECTS OF REDEVELOPMENT TODAY ARE SOMEWHAT UNCERTAIN DESPITE
MODEL QPF SOLUTIONS TO THE CONTRARY. LINGERING MORNING SHOWERS AND
THEN SCATTERED TSRA LATER ARE DEFINITELY NOT OUT OF THE QUESTION
LOCALLY BUT THE MORE FAVORABLE AREAS OF MOISTURE ADVECTION AND STEEP
MID LEVEL LAPSE RATES ARE FARTHER SOUTH TOWARD CENTRAL ILLINOIS AND
FARTHER NORTH ALONG THE WI/MN STATE LINE.
DESPITE THE APPROACH OF A SURFACE/850 FRONTAL ZONE...THE UPPER LEVEL
WAVES APPEAR TO BE SOMEWHAT OUT OF SYNC AND MORE
PROGRESSIVE...LEAVING THE LOWER LEVEL FEATURES UNDER AREAS OF RISING
HEIGHTS ALOFT. IN THE 0530Z SPC DAY 1 OUTLOOK THE SLIGHT RISK
EXTENDS NORTHWEST TOWARD MSP AND THEN WELL SOUTH AND EAST THROUGH
THE TENNESSEE AND OHIO VALLEYS. WOULD NOT BE SURPRISED TO SEE THIS
SPLIT IN LATER UPDATES...WITH THE THUMB TO OUR NORTHWEST SEPARATED
FROM THE AREA TO OUR SOUTH. BUT THAT WOULD BE CUTTING IT PRETTY
FINE GIVEN THE OVERALL UNCERTAINTY WITH THIS SITUATION.
LONG STORY SHORT...FOR TODAY THE PLAN WILL BE TO LOWER POPS INTO THE
CHANCE CATEGORY BY AFTERNOON FOR MOST OF THE AREA BUT KEEP IN MIND
THE PWATS APPROACHING TWO INCHES AND THEREFORE MAINTAIN THE FLASH
FLOOD WATCH AND THE MENTION OF TSRA.
AFTER TODAY THE SITUATION BECOMES ONLY SLIGHTLY MORE CLEAR BUT OF
SEEMINGLY LESSER IMPACT.
AMPLIFICATION OF THE LARGE SCALE FLOW WILL BEGIN TO INFLUENCE THE
LOCAL AREA BY TONIGHT INTO THURSDAY AFTER THE SURFACE TROUGH PUSHES
THROUGH THE AREA AND WINDS AT ALL LEVELS TURN TO THE NORTHWEST. LOW
LEVEL WARMTH AND HUMIDITY DO NOT REALLY DEPART UNTIL FRIDAY WHEN THE
EXPANDING EASTERN TROUGH PUSHES THE UPPER JET SOUTH OF THE AREA AND
USHERS IN SLIGHTLY DRIER BUT MILDER AIR.
WITH ONLY MARGINAL LAPSE RATES AND HEIGHTS ALOFT CONTINUING TO
INCREASE...NEITHER THURSDAY NOR FRIDAY LOOK PARTICULARLY FAVORABLE
FOR WIDESPREAD PRECIPITATION. AS MENTIONED IN AN EARLIER
DISCUSSION...IT WOULD NOT TAKE MUCH OF A SHORTWAVE IN THE UPPER FLOW
TO SUPPORT AN AFTERNOON SHOWER...SO WILL CONTINUE TO CARRY SLIGHT
CHANCE POPS ON BOTH DAYS.
BY THE WEEKEND THE CONVECTIVE INSTABILITY APPEARS TO HAVE
DECREASED...BUT THE PRESENCE OF BOTH A SURFACE AND UPPER LEVEL
TROUGH DROPPING SOUTH ACROSS THE AREA WILL STILL SUPPORT LARGE SCALE
LIFT...PRIMARILY TO THE SOUTH ON SUNDAY. PRECIP CHANCES FINALLY
DECREASE BY EARLY NEXT WEEK AS THE SURFACE AND UPPER SUPPORT
DIMINISH...BUT UNSEASONABLY COOL AIR REMAINS IN PLACE WITH CONTINUED
NORTH TO NORTHEASTERLY WINDS.
LENNING
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SOME UNCERTAINTIES REMAIN WITH WIND DIRECTION THIS AFTERNOON
* MVFR VSBY IN BR POSSIBLE LATE TONIGHT/VERY EARLY THURS AM
* CHANCE OF TSRA AGAIN THURS PM
IZZI
//DISCUSSION...UPDATED 18Z...
OVERNIGHT AND MORNING THUNDERSTORMS HAVE FINALLY DIMINISHED
LEAVING A LARGE POOL OF STABLE AIR OVER THE REGION WHICH SHOULD
RESULT IN MINIMAL THREAT ADDITIONAL CONVECTION DEVELOPING THIS
AFTERNOON OR TONIGHT. WINDS HAVE RAPIDLY SWUNG AROUND TO THE S/SSW
AND WITH FURTHER HEATING/MIXING WOULD EXPECT THE SOUTHERLY WINDS
TO CONTINUE THROUGH THE AFTERNOON WITH ONLY A MINIMAL THREAT OF
WINDS BACKING TO EASTERLY DIRECTION AFTER TODAY. WINDS SHOULD GO
LIGHT/VARIABLE TONIGHT AND COULD ACTUALLY SEE SOME PATCY GROUND
FOG DEVELOP LATE TONIGHT...PARTICULARLY IN THE OUTLYING AREAS. AN
UPPER LEVEL DISTURBANCE IS PROGGED TO SWING THROUGH THE REGION
DURING THE AFTERNOON RESULTING IN SCT`D TSRA DEVELOPING...SOME
POSSIBLY STRONG TO SEVERE.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* LOW-MEDIUM CONFIDENCE IN WIND DIRECTION THIS AFTERNOON
* MEDIUM-HIGH CONFIDENCE IN DRY WEATHER THROUGH THURS MORNING
* LOW-MEDIUM CONFIDENCE IN TSRA CHANCES THURS AFTERNOON
* HIGH CONFIDENCE IN OTHER ELEMENTS
IZZI
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...VFR.
FRIDAY THROUGH SATURDAY...PERIODIC CHANCES OF TSRA.
SATURDAY THROUGH MONDAY...PERIODIC CHANCES OF SHRA.
TUESDAY...CHC TSRA.
BMD
&&
.MARINE...
150 AM CDT
ELONGATED SFC LOW PRESSURE TROUGH OVER THE MID-UPPER MISSOURI
VALLEY WILL MOVE SLOWLY EAST TODAY...WITH VARYING MODEL FORECASTS
DEVELOPING A WEAK SURFACE LOW PRESSURE WAVE IN THE VICINITY OF
NORTHERN IL/IND OR SOUTHERN LAKE MICHIGAN BY THIS EVENING. SOUTH
TO SOUTHEAST WINDS SHOULD DIMINISH IN SPEED AS THE GRADIENT
WEAKENS WITH THE APPROACH OF THE TROUGH THIS AFTERNOON...WITH LAKE
BREEZE ESPECIALLY ALONG THE WESTERN SHORE. THUNDERSTORMS WILL BE
POSSIBLE ESPECIALLY OVER THE SOUTHERN HALF OF THE LAKE...WHICH MAY
RESULT IN SOME LOCALLY STRONGER WINDS. WINDS MAY BECOME SOMEWHAT
VARIABLE AT 10 KT OR LESS TONIGHT AS THE SURFACE TROUGH/COLD FRONT
MOVE SLOWLY ACROSS THE LAKE...EVENTUALLY TAKING ON A WEST-
NORTHWEST DIRECTION THURSDAY AS THE TROUGH MOVES OFF TO THE EAST.
SPEEDS SHOULD REMAIN GENERALLY LIGHT HOWEVER...WITH A RELATIVELY
WEAK GRADIENT INTO FRIDAY.
WEAK HIGH PRESSURE RIDGING WILL DEVELOP SOUTHEAST ACROSS THE
NORTHERN AND CENTRAL HIGH PLAINS INTO THE WEEKEND...WHILE THE LOW
PRESSURE WAVE EVENTUALLY DEEPENS EAST OF THE LAKES. THIS WILL
MAINTAIN A PROLONGED PERIOD OF NORTH-NORTHWEST FLOW ACROSS LAKE
MICHIGAN...THOUGH AGAIN WITH SPEEDS GENERALLY 15 KT OR LESS THROUGH
THE PERIOD.
OTHERWISE...IN THE NEAR TERM SOME PATCHY DENSE FOG WILL LINGER
ACROSS THE NORTHERN PART OF THE LAKE THIS MORNING.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ023-ILZ033-ILZ039 UNTIL 7 PM WEDNESDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 7
PM WEDNESDAY.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1124 AM CDT WED JUN 26 2013
.DISCUSSION...
308 AM CDT
THE LATEST IN A SERIES OF WEAK SHORTWAVES IN QUASI-ZONAL SOUTHERN
STREAM FLOW HAS BEEN SUPPORTING WIDESPREAD CONVECTION AS IT MOVES
TOWARD THE AREA EARLY THIS MORNING. GRADUALLY OVER THE NEXT TWO
DAYS THE LARGE SCALE PATTERN WILL BE AMPLIFYING INTO A BROAD
ANTICYCLONE ACROSS THE WESTERN CONUS AND A DEEPENING LONGWAVE TROUGH
OVER THE EASTERN STATES. THE WARM HUMID CONDITIONS OF RECENT DAYS
WILL BE REPLACED BY COOL HUMID CONDITIONS BY THE WEEKEND...WHICH
THEN WILL PERSIST INTO NEXT WEEK.
FIRST QUESTION CONCERNS PRECIPITATION TRENDS FOR TODAY. AT 08Z THE
EXISTING AREAS OF CONVECTION ACROSS NORTHEAST IOWA INTO NORTHERN
ILLINOIS WERE LOCATED ALONG FAVORABLE GRADIENTS OF MOISTURE
TRANSPORT ON THE LEADING EDGE OF THE LOW LEVEL JET...AND UNDER A
WEAK SHORTWAVE DEPICTED IN THE RAP MODEL AND VWP OBS AT 850 AND 700
MB. THIS ACTIVITY SHOULD BE MOVING ACROSS NORTHEASTERN ILLINOIS
DURING THE PREDAWN HOURS BUT THEN BEGINNING TO WEAKEN AS THE
LLJ VEERS AND ADJUSTS ITS FOCUS MORE TOWARD CENTRAL AND SOUTHERN
ILLINOIS.
IF THIS ACTIVITY DOES DISSIPATE AS EXPECTED TOWARD MORNING...THE
PROSPECTS OF REDEVELOPMENT TODAY ARE SOMEWHAT UNCERTAIN DESPITE
MODEL QPF SOLUTIONS TO THE CONTRARY. LINGERING MORNING SHOWERS AND
THEN SCATTERED TSRA LATER ARE DEFINITELY NOT OUT OF THE QUESTION
LOCALLY BUT THE MORE FAVORABLE AREAS OF MOISTURE ADVECTION AND STEEP
MID LEVEL LAPSE RATES ARE FARTHER SOUTH TOWARD CENTRAL ILLINOIS AND
FARTHER NORTH ALONG THE WI/MN STATE LINE.
DESPITE THE APPROACH OF A SURFACE/850 FRONTAL ZONE...THE UPPER LEVEL
WAVES APPEAR TO BE SOMEWHAT OUT OF SYNC AND MORE
PROGRESSIVE...LEAVING THE LOWER LEVEL FEATURES UNDER AREAS OF RISING
HEIGHTS ALOFT. IN THE 0530Z SPC DAY 1 OUTLOOK THE SLIGHT RISK
EXTENDS NORTHWEST TOWARD MSP AND THEN WELL SOUTH AND EAST THROUGH
THE TENNESSEE AND OHIO VALLEYS. WOULD NOT BE SURPRISED TO SEE THIS
SPLIT IN LATER UPDATES...WITH THE THUMB TO OUR NORTHWEST SEPARATED
FROM THE AREA TO OUR SOUTH. BUT THAT WOULD BE CUTTING IT PRETTY
FINE GIVEN THE OVERALL UNCERTAINTY WITH THIS SITUATION.
LONG STORY SHORT...FOR TODAY THE PLAN WILL BE TO LOWER POPS INTO THE
CHANCE CATEGORY BY AFTERNOON FOR MOST OF THE AREA BUT KEEP IN MIND
THE PWATS APPROACHING TWO INCHES AND THEREFORE MAINTAIN THE FLASH
FLOOD WATCH AND THE MENTION OF TSRA.
AFTER TODAY THE SITUATION BECOMES ONLY SLIGHTLY MORE CLEAR BUT OF
SEEMINGLY LESSER IMPACT.
AMPLIFICATION OF THE LARGE SCALE FLOW WILL BEGIN TO INFLUENCE THE
LOCAL AREA BY TONIGHT INTO THURSDAY AFTER THE SURFACE TROUGH PUSHES
THROUGH THE AREA AND WINDS AT ALL LEVELS TURN TO THE NORTHWEST. LOW
LEVEL WARMTH AND HUMIDITY DO NOT REALLY DEPART UNTIL FRIDAY WHEN THE
EXPANDING EASTERN TROUGH PUSHES THE UPPER JET SOUTH OF THE AREA AND
USHERS IN SLIGHTLY DRIER BUT MILDER AIR.
WITH ONLY MARGINAL LAPSE RATES AND HEIGHTS ALOFT CONTINUING TO
INCREASE...NEITHER THURSDAY NOR FRIDAY LOOK PARTICULARLY FAVORABLE
FOR WIDESPREAD PRECIPITATION. AS MENTIONED IN AN EARLIER
DISCUSSION...IT WOULD NOT TAKE MUCH OF A SHORTWAVE IN THE UPPER FLOW
TO SUPPORT AN AFTERNOON SHOWER...SO WILL CONTINUE TO CARRY SLIGHT
CHANCE POPS ON BOTH DAYS.
BY THE WEEKEND THE CONVECTIVE INSTABILITY APPEARS TO HAVE
DECREASED...BUT THE PRESENCE OF BOTH A SURFACE AND UPPER LEVEL
TROUGH DROPPING SOUTH ACROSS THE AREA WILL STILL SUPPORT LARGE SCALE
LIFT...PRIMARILY TO THE SOUTH ON SUNDAY. PRECIP CHANCES FINALLY
DECREASE BY EARLY NEXT WEEK AS THE SURFACE AND UPPER SUPPORT
DIMINISH...BUT UNSEASONABLY COOL AIR REMAINS IN PLACE WITH CONTINUED
NORTH TO NORTHEASTERLY WINDS.
LENNING
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* SCTD SHRA IN VC OF BUT MOSTLY MISSING ORD/MDW
* SOUTHEAST WINDS WILL TURN MORE SOUTHERLY THIS AFTERNOON
IZZI
//DISCUSSION...UPDATED 14Z...
UPPER LEVEL DISTURBANCE MOVING ACROSS NORTHERN ILLINOIS WILL
CONTINUE TO PRODUCE SCT`D SHOWERS AND THUNDERSTORMS THROUGH THE
REMAINDER OF THE MORNING HOURS. MORE ORGANIZED LINE OF TSRA SW OF
JOT WILL LIFT NE AND LIKELY IMPACT MDW BY AROUND 15Z WITH PERIOD
OF +TSRA AND GUSTY WINDS POSSIBLE. AS DISTURBANCE MOVES SLOWLY
EAST THE COVERAGE OF SHRA/TSRA WILL PROBABLY DECREASE THIS
AFTERNOON. SMALL SFC LOW SW OF RFD LIKELY TO MAINTAIN MOSTLY
EASTERLY COMPONENT TO WINDS THROUGH THE MORNING HOURS WITH LOW
CONFIDENCE ON THE WIND DIRECTION HEADING INTO THE AFTERNOON.
IZZI
UPDATED 12Z...
LINE OF THUNDERSTORMS SPANS FROM NORTH CENTRAL ILLINOIS ESE INTO
NORTHERN INDIANA AND IS FOCUSED ON THE NOSE OF A LOW LEVEL JET.
WHILE THE FOCUS SHOULD GENERALLY LIFT NORTH AND WEAKEN OVER THE NEXT
COUPLE HOURS...THE STORMS HAVE BEEN BACK BUILDING TO THE SOUTH WHICH
HAS KEPT IT OVER OR ON THE DOORSTEP ON ORD...AND MAY CONTINUE TO
PERSIST OVER THE NEXT HOUR OR TWO. WINDS HAVE BECOME MORE
NORTHEAST/EASTERLY UNDER THE INFLUENCE OF CONVECTION...AND CIGS HAVE
DROPPED TO MVFR. AS CONVECTION WANES THIS MORNING...EXPECT SOUTHERLY
WINDS TO RESUME AND FOR MVFR CIGS TO LIFT BACK TO VFR. THERE SHOULD
BE A LULL IN ACTIVITY FROM MID MORNING TO EARLY THIS AFTERNOON FOR
THE CHICAGO TERMINALS. ATTENTION TURNS TO AN APPROACHING MCV MOVING
OVER THE MISSISSIPPI RIVER EARLY THIS MORNING. WHILE THERE IS AN
EXPANSIVE AREA OF STRATIFORM PRECIP AHEAD OF THIS FEATURE...IT
SHOULD DRY/ERODE SOME AS IT PROGRESSES EAST. BECAUSE OF THE CLOUD
COVER AND PERHAPS LIGHT RAIN...IT APPEARS THERE WILL BE LITTLE
OPPORTUNITY FOR THE ATMOSPHERE TO DESTABILIZE TODAY THOUGH THERE
WILL BE SOME PERSISTENT/FESTERING EMBEDDED CONVECTION ASSOCIATED
WITH THE MCV. WINDS APPEAR TO GO LIGHT AND VARIABLE TONIGHT...AND
NAM GUIDANCE AS WELL AS LAV POINT TO FOG/BR AND IFR CIGS DEVELOPING
OVERNIGHT. WILL NOT MENTION YET IN TAFS TO WAIT AND SEE HOW THE REST
OF THE DAY EVOLVES AND IF THERE IS ANY SIGNIFICANT DRYING THIS
AFTERNOON/EVENING.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM-HIGH CONFIDENCE IN SHRA OVER THE REGION THROUGH EARLY
AFTERNOON
* MEDIUM CONFIDENCE IN WINDS THIS AFTERNOON
IZZI
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...VFR.
FRIDAY THROUGH SATURDAY...PERIODIC CHANCES OF TSRA.
SATURDAY THROUGH MONDAY...PERIODIC CHANCES OF SHRA.
TUESDAY...CHC TSRA.
BMD
&&
.MARINE...
150 AM CDT
ELONGATED SFC LOW PRESSURE TROUGH OVER THE MID-UPPER MISSOURI
VALLEY WILL MOVE SLOWLY EAST TODAY...WITH VARYING MODEL FORECASTS
DEVELOPING A WEAK SURFACE LOW PRESSURE WAVE IN THE VICINITY OF
NORTHERN IL/IND OR SOUTHERN LAKE MICHIGAN BY THIS EVENING. SOUTH
TO SOUTHEAST WINDS SHOULD DIMINISH IN SPEED AS THE GRADIENT
WEAKENS WITH THE APPROACH OF THE TROUGH THIS AFTERNOON...WITH LAKE
BREEZE ESPECIALLY ALONG THE WESTERN SHORE. THUNDERSTORMS WILL BE
POSSIBLE ESPECIALLY OVER THE SOUTHERN HALF OF THE LAKE...WHICH MAY
RESULT IN SOME LOCALLY STRONGER WINDS. WINDS MAY BECOME SOMEWHAT
VARIABLE AT 10 KT OR LESS TONIGHT AS THE SURFACE TROUGH/COLD FRONT
MOVE SLOWLY ACROSS THE LAKE...EVENTUALLY TAKING ON A WEST-
NORTHWEST DIRECTION THURSDAY AS THE TROUGH MOVES OFF TO THE EAST.
SPEEDS SHOULD REMAIN GENERALLY LIGHT HOWEVER...WITH A RELATIVELY
WEAK GRADIENT INTO FRIDAY.
WEAK HIGH PRESSURE RIDGING WILL DEVELOP SOUTHEAST ACROSS THE
NORTHERN AND CENTRAL HIGH PLAINS INTO THE WEEKEND...WHILE THE LOW
PRESSURE WAVE EVENTUALLY DEEPENS EAST OF THE LAKES. THIS WILL
MAINTAIN A PROLONGED PERIOD OF NORTH-NORTHWEST FLOW ACROSS LAKE
MICHIGAN...THOUGH AGAIN WITH SPEEDS GENERALLY 15 KT OR LESS THROUGH
THE PERIOD.
OTHERWISE...IN THE NEAR TERM SOME PATCHY DENSE FOG WILL LINGER
ACROSS THE NORTHERN PART OF THE LAKE THIS MORNING.
RATZER
&&
.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 WEDNESDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 7
PM WEDNESDAY.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
337 PM CDT WED JUN 26 2013
.SYNOPSIS...
ISSUED AT 334 PM CDT WED JUN 26 2013
18Z SFC ANALYSIS HAS THE REMNANTS OF A MESO HIGH AT KDBQ AND A MESO
LOW BETWEEN KSQI AND KFEP. AN OUTFLOW BOUNDARY FROM THE MCS RAN FROM
LAKE MICHIGAN THROUGH CENTRAL ILLINOIS AND THEN TO NEAR KMXO. THE
SYNOPTIC COLD FRONT RAN FROM NEAR KMSP...TO KDSM...TO KFNB. AHEAD OF
THE SYNOPTIC FRONT SEVERAL WEAK TROFS/BOUNDARIES WERE ACROSS EASTERN
IOWA AND MISSOURI. DEW POINTS WERE IN THE 70S WITH 60S OVER THE
GREAT LAKES AND BEHIND THE COLD FRONT.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 334 PM CDT WED JUN 26 2013
DIURNAL CONVECTION HAS FIRED ALONG A THETA E GRADIENT IN CENTRAL
IOWA AND ALONG A PRE-FRONTAL TROF. RAP TRENDS BRING THIS FEATURE
INTO THE WESTERN CWFA LATE THIS AFTERNOON BEFORE WEAKENING THE
THETA E GRADIENT. THUS THE NEW STORMS THAT HAVE DEVELOPED JUST WEST
OF THE CWFA ARE EXPECTED TO MOVE INTO THE WESTERN CWFA DURING THE
LATE AFTERNOON HOURS AND THEN SLOWLY DISSIPATE WITH SUNSET.
AHEAD OF THIS CONVECTION...ISOLATED SHOWERS AND STORMS ARE EXPECTED
TO DEVELOP DURING PEAK HEATING THAT WILL ALSO SLOWLY DISSIPATE WITH
SUNSET.
THE SYNOPTIC COLD FRONT WILL MOVE THROUGH THE CWFA TONIGHT DROPPING
DEW POINTS ABOUT 5 TO 7 DEGREES. WINDS ARE EXPECTED TO BE FAIRLY
LIGHT AND GIVEN THE WET GROUND IN SOME AREAS THERE IS A POTENTIAL
FOR SOME FOG DEVELOPMENT AFTER MIDNIGHT. THIS WILL HAVE TO BE
WATCHED TO SEE HOW IT WILL EVOLVE.
QUIET AND DRY CONDITIONS WILL BE SEEN THURSDAY MORNING ACROSS THE
AREA WHILE AN UPPER LOW MOVES INTO THE NORTHERN GREAT LAKES. DAY
TIME HEATING COMBINED WITH SLIGHTLY COOLER AIR ALOFT SHOULD ALLOW
NEW CONVECTION TO DEVELOP DURING THE AFTERNOON. THE LOWER MOISTURE
LEVELS IN THE ATMOSPHERE AND NORTHWEST FLOW SHOULD RESULT IN THE
CONVECTION BEING ISOLATED TO SCATTERED IN NATURE. ..08..
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 334 PM CDT WED JUN 26 2013
THURSDAY NIGHT AND FRIDAY...AS NORTHWESTERLY STEERING FLOW TAKES
OVER WITH UPPER RIDGE RETROGRADE...DIGGING UPPER WAVE INTO THE
NORTHWESTERN GRT LKS WILL CONNECT WITH TROF INTO THE CENTRAL PLAINS
FOR CONTINUED ISOLATED TO WDLY SCTRD SHOWER/STORM THREAT INTO MID
THU EVENING. BUT BEST FORCING AND CONVERGENCE TO REMAIN JUST TO THE
NORTHEAST AND SOUTHWEST OF THE DVN CWA. WILL EXTEND LOW CHC POPS IN
THE FAR EAST AND MAINTAIN ONGOING POPS IN THE SOUTHWESTERN CWA
THROUGH 03Z FRI. AFTER TROF EMBEDDED IN NW STEERING FLOW
PASSES...EXPECT SOME CLEARING AND COOLER CONDITIONS INTO EARLY FRI
MORNING WITH LOWS WELL DOWN INTO THE 60S...POSSIBLY SOME LOWER 60S
NORTH OF I80. LARGE UPPER CYCLONE COMPLEX TO THEN CONTINUE TO SETTLE
ACRS THE HEART OF THE GRT LKS ON FRI. ASSOCIATED VORT SPOKE ALOFT
AND MID LEVEL COOL POOL TO INDUCE DEEP STEEP LAPSE RATES AND A
INSTABILITY SHOWER SET UP ACRS MN INTO WI AND IL. SOME POTENTIAL FOR
THUNDERSTORMS WITH VERTICAL THERMODYNAMIC PROFILES SUPPORTIVE OF
HAIL IF ENHANCED UPDRAFTS CAN MAINTAIN. THIS ACTIVITY MORE LIKELY
FRIDAY AFTERNOON ACRS THE NORTHEASTERN THIRD OF THE DVN CWA AND WILL
ADJUST POPS ACCORDINGLY. DESPITE INCOMING COOLER AIR INFLUX/
ADVECTION...DEEP MIXING PROFILES UP TO H8 MB STILL TO BOOST TEMPS
INTO THE LOW TO MID 80S WHILE SFC DPTS DRY-DOWN MIX INTO THE LOWER
60S TO UPPER 50S...MAYBE LOWER THAN GUIDANCE SUGGESTS INTO THE MID
50S. BREEZY NORTHWEST WINDS AS WELL IN THIS SCENARIO OF 15 TO 20+
MPH. TIGHTENING CYCLONIC FLOW ALOFT MAY KEEP SHOWERS PECULATING WELL
INTO FRI EVENING BEFORE NOCTURNAL PROCESSES TAKE OVER. EVEN WITH
CLOUD DEBRIS...STILL A COOLER NIGHT WITH WIDESPREAD LOWS IN THE LOW
TO MID 60S.
SATURDAY AND SUNDAY...UNSTABLE VERTICAL PROFILES UNDER ONGOING
CYCLONIC FLOW AND ANOTHER INCOMING VORT SPOKE MAY PRODUCE MORE
WIDESPREAD SHOWERS AND A FEW STORMS/FURTHER TO THE WEST/THEN ON
FRIDAY. CANADIAN LLVL RIDGE AXIS DUMPING DOWN TO THE WEST OF THE AREA
ACRS THE PLAINS. FCST SOUNDING SUGGEST ANOTHER DAY OF DEEP MIXING...
BUT CONTINUED LLVL COOL POOL INFLUX AS WELL AS SHOWERS/CLOUDS WILL
HAVE A BETTER SHOT TO KEEP TEMPS IN THE 70S. CLEAR OUT SAT NIGHT AS
LARGE STOUT CANADIAN HIGH TAKES GRIP OF THE UPPER MIDWEST AND COULD
FOSTER WIDESPREAD LOWS WELL DOWN IN THE 50S BY EARLY SUNDAY MORNING.
HIGH PRESSURE TO THEN TO MIGRATE TOWARD THE GRT LKS ON SUNDAY...WHILE
ALOFT DEEP LONG WAVE TROF EXTENDS TO THE GULF ALONG AND EAST OF THE
MS RVR VALLEY. APPEARS LESSENING CHANCE OF SHOWERS SUNDAY AND
BOUNDARY LAYER NORTHEASTERLY FETCH AGAIN TO POSSIBLY KEEP TEMPS IN
THE 70S FOR HIGHS. SUNDAY NIGHT SEASONABLY COOL AND WELL DOWN IN THE
50S ALONG AND NORTH OF I80.
MONDAY THROUGH NEXT WEDNESDAY...LONG RANGE SIGNALS SUGGEST A GENERAL
BLOCKED PATTERN WITH BOOKEND RIDGES ON THE COASTS AND MID CONUS L/W
TROFFINESS PERSISTING THROUGH WED. BUT THEY ALSO SUGGEST IT TO START
TO MODIFY AND BREAK DOWN THE L/W TROF FEATURE AFTER TUE. THUS IN
GENERAL...BELOW NORMAL TEMPS LOOK TO CONTINUE IN THE VCNTY OF THIS
UPPER TROF..AS WELL AS ALMOST A DAILY THREAT OF POP UP SHOWERS AND
A FEW STORMS. BETTER CHANCES OFF THOUGH TO THE SOUTHEAST OF THE DVN
CWA IN VCNTY OF UPPER LOW MON INTO TUE. ..12..
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1225 PM CDT WED JUN 26 2013
DIURNAL CONVECTION HAS DEVELOPED OVER CENTRAL IOWA AHEAD OF THE COLD
FRONT. THIS CONVECTION WILL MOVE INTO EASTERN IOWA AND SLOWLY
DISSIPATE WITH SUNSET. HIGH MOISTURE LEVELS IN THE ATMOSPHERE HAS
RESULTED IN SOME MVFR CIGS TO DEVELOP. IF A TSRA WOULD IMPACT A TAF
SITE A BRIEF PERIOD OF IFR CONDITIONS WILL BE POSSIBLE. AFT SUNSET
VFR CONDITIONS ARE EXPECTED. HOWEVER...THE WET GROUND AND LIGHT
WINDS MAY ALLOW FOG TO DEVELOP AFT 06Z/27. IF THIS OCCURS...THERE IS
A POTENTIAL FOR IFR/LIFR CONDITIONS. ..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...08
SHORT TERM...08
LONG TERM...12
AVIATION...08
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1233 PM CDT WED JUN 26 2013
.UPDATE...
ISSUED AT 1225 PM CDT WED JUN 26 2013
THE NOCTURNAL MCS HAS DISSIPATED ACROSS ILLINOIS. BOUNDARIES LEFT
OVER FROM THIS CONVECTION ALLOWED NEW CONVECTION TO DEVELOP THIS
MORNING BEFORE DOWNWARD MOTION FROM THE MCV CAUSED IT TO ALSO
DISSIPATE.
WATER VAPOR SHOWS A RESPECTABLE VORT MAX MOVING FROM MINNESOTA
INTO IOWA. RAP TRENDS INDICATE DOWNWARD MOTION WILL CONTINUE INTO
THE EARLY AFTERNOON BEFORE LIFT FROM THE APPROACHING VORT MAX
INCREASES. THIS LIFT MAY BE ENOUGH WHEN COMBINED WITH THE
APPROACHING COLD FRONT TO ALLOW ISOLATED TO SCATTERED CONVECTION
TO DEVELOP MID TO LATE AFTERNOON. ..08..
UPDATE ISSUED AT 1000 AM CDT WED JUN 26 2013
THE NOCTURNAL MCS THAT PRODUCED THE EXTREMELY HEAVY RAINFALL IS
RAPIDLY DECAYING ACROSS ILLINOIS. COLD POOLS AND OUTFLOW
BOUNDARIES FROM THE MCS IS PROVIDING A FOCUS FOR NEW CONVECTION
ACROSS IOWA.
WATER VAPOR SHOWS A RESPECTABLE VORT MAX DIVING SOUTHEAST INTO
IOWA FROM MINNESOTA WHICH IS HELPING TO DRIVE SOME OF THE
CONVECTION. DOWNWARD MOTION BEHIND THE DECAYING MCS IS HELPING TO
DISSIPATE THE NEW CONVECTION ACROSS IOWA. HOWEVER...RAP TRENDS
SHOW LIFT WILL BE ON THE INCREASE AGAIN BY LATE MORNING AND INTO
THE AFTERNOON. SO...CONVECTION IS EXPECTED TO PERSIST AND MAY
EXPAND SOME IN AREAL COVERAGE DURING THE AFTERNOON. ..08..
&&
.SYNOPSIS...
ISSUED AT 335 AM CDT WED JUN 26 2013
AS OF 08Z LOW PRESSURE WAS FOUND IN WESTERN IOWA...WITH TROUGH
EXTENDING NORTH INTO THE RED RIVER VALLEY AND COLD FRONT TRAILING
OFF TO THE SW INTO KANSAS. TWO DIFFUSE WARM FRONTAL BOUNDARIES
WERE FOUND ALONG NORTHERN PARTS OF CWFA AND JUST TO THE SOUTH. AN
MCV WAS SEEN ON RADAR JUST SW OF DUBUQUE WITH A LINE OF STORMS
EXTENDING SW TO NEAR IOWA CITY. THIS LINE WAS STARTING TO INDICATE
SOME BOWING AGAIN. ADDITIONAL CONVECTIVE ACTIVITY LINGERS TO THE
NW WHERE STORMS HAD EARLY SAT STILL CAUSING SOME FLASH FLOODING IN
BUCHANAN COUNTY AND NORTHERN LINN COUNTY. DEW POINTS ARE MAINLY
IN THE MID 60S TO LOWER 70S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT WED JUN 26 2013
FOCUS ON SHORT TERM IS IN WALKING OUT THIS EARLY MORNING
CONVECTION. MAINLY TURNING OUT TO BE HEAVY RAIN EVENT...WITH SOME
MARGINALLY SEVERE WIND GUSTS POSSIBLE IN BOWING PHASES AS THE LINE
MOVES ACROSS EAST CENTRAL IOWA AND NW ILLINOIS...GENERALLY ALONG
AND NE OF A LINE FROM WASHINGTON IOWA...TO MACOMB ILLINOIS. EXPECT
ACTIVITY TO DIMINISH THROUGH THE MORNING HOURS AS LOW MOVES ACROSS
THE AREA AND SUBSIDENCE ON NW FLOW WORKS INTO THE AREA BEHIND THE
DEPARTING STORMS.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 335 AM CDT WED JUN 26 2013
NOT MUCH CHANGE TO THE EXTENDED FORECAST WHICH IS RELATIVELY QUIET
FOR A CHANGE...COOLER...AND LESS HUMID. A TROUGH DIGS ACROSS THE
EAST COAST WHILE A RIDGE BUILDS...WITH THE CWFA IN NW FLOW THROUGH
THE PERIOD. WEAK DISTURBANCES WILL MOVE ACROSS THE AREA...WITH
ONLY SLIGHT/LOW END CHANCE POPS ATTM.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1225 PM CDT WED JUN 26 2013
VFR WX IS EXPECTED THROUGH 02Z/27. DOWNWARD MOTION BEHIND THE
DISSIPATED TSRA COMPLEX WILL SUPPRESS NEW CONVECTION UNTIL AFT
20Z/26. PROBABILITY OF A TSRA AFFECTING A TAF SITE IS LOW BUT VCTS
WAS INCLUDED IN THE 18Z TAFS. AFT 02Z/27 VFR WX SHOULD CONTINUE.
LIGHT WINDS AND WET GROUND MAY RESULT IN FOG DVLPG AFT 06Z/27. IF
THIS OCCURS...MVFR CONDITIONS WOULD BE SEEN WITH A POTENTIAL FOR
IFR/LIFR CONDITIONS. ..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...14
SHORT TERM...14
LONG TERM...14
AVIATION...08
AREA FORECAST DISCUSSION
NWS DULUTH MN
103 PM CDT WED JUN 26 2013
.AVIATION...
THUNDERSTORMS...CONTAINING HEAVY RAINFALL...WILL ACCOMPANY A
FRONTAL BOUNDARY AS IT CROSSES OVER THE MINNESOTA ARROWHEAD AND
NORTHERN WISCONSIN THIS AFTERNOON. THE STRONGEST STORMS...LASTING
ABOUT AN HOUR...WILL BE FOUND IN THE HAYWARD AREA BETWEEN 19Z-21Z
THIS AFTERNOON. A FEW ADDITIONAL SHOWERS OR THUNDERSTORMS WILL BE
POSSIBLE THOUGH THE AFTERNOON ACROSS NORTHEAST MINNESOTA WHERE
PERIODS OF MVFR CEILINGS AROUND 2 KFT WILL PERSIST. HAVE KEPT
VCTS/VCSH AT ALL MINNESOTA TERMINALS FOR THE REMAINDER OF THE DAY
WITH IMPROVING CEILINGS THROUGH THE AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 1045 AM CDT WED JUN 26 2013/
UPDATE...
THE FOCUS FOR THIS UPDATE IS THE POTENTIAL OF SHOWERS AND
THUNDERSTORMS THROUGH THIS EVENING. THE ONLY REMAINING SHOWERS AND
STORMS AT THE TIME OF THIS UPDATE ARE NEAR A VORTEX MOVING
NORTHEAST NEAR IN NORTHERN ST. LOUIS COUNTY. REDEVELOPMENT ALONG
AND AHEAD OF TROUGH OF LOW PRESSURE MOVING THROUGH THE NORTHLAND
TODAY IS LIKELY...AT LEAST IN NW WISCONSIN AND THE MINNESOTA
ARROWHEAD. THE HRRR HAS BEEN CONSISTENTLY INDICATING A BAND OF
STORMS FORMING IN NW WISCONSIN BY EARLY THIS AFTERNOON AND EXITING
MID TO LATE THIS AFTERNOON. I ALTERED PCPN CHANCES TO REFLECT THE
HIGHEST CHANCES ACROSS THE EASTERN FORECAST AREA...WHILE LOWERED
CHANCES ACROSS THE WEST. WHILE THERE SHOULD BE A GENERAL
DECREASING CHANCE OF PCPN FROM WEST TO EAST THIS AFTERNOON INTO
THIS EVENING...SOME MODELS ARE INDICATING SOME SHOWERS AND STORMS
MOVING INTO THE WESTERN FORECAST AREA FROM NW MINNESOTA THIS
EVENING AND OVERNIGHT...SO I KEPT LOW CHANCES OVER JUST ABOUT ALL
OF THE FORECAST AREA THROUGH AT LEAST THIS EVENING. IT STILL
APPEARS WE COULD SEE SOME STRONG...MAYBE SEVERE STORMS...ACROSS NW
WISCONSIN. WHILE THERE MAY BE LOTS OF CAPE...WITH THE NAM12
INDICATING AT LEAST 4000 J/KG OF MOST UNSTABLE CAPE ALONG THE CAPE
AXIS...THE LIMITING FACTOR FOR SEVERE WEATHER WILL LIKELY BE WIND
SHEAR. THE NAM12 IS INDICATING LOW BULK SHEAR...LESS THAN 20 KNOTS
FOR 0-6KM...ALONG THE CAPE AXIS. HOWEVER...WE WILL NEED TO WATCH
CLOSELY FOR DEVELOPMENT AND SEE IF THE NAM12 WIND SHEAR HOLDS
TRUE. IF THERE IS MORE WIND SHEAR THAN THE NAM12 SUGGESTS...THEN
SOME STORMS COULD MORE EASILY BECOME SEVERE.
AS FAR AS TEMPERATURES TODAY...THE LATEST MOS GUIDANCE IS MUCH
WARMER IN SOME AREAS COMPARED TO THE PREVIOUS FORECAST. I INCREASED
TEMPERATURES BY UP TO SEVERAL DEGREES...NOTABLE ACROSS INLAND NW
WISCONSIN.
PREV DISCUSSION... /ISSUED 316 AM CDT WED JUN 26 2013/
SHORT TERM...SHORT TERM CONCERNS IS MOVEMENT OF THUNDERSTORM
COMPLEX IN NW MN THIS MORNING AND EFFECT ON FORECAST AREA. SECOND
CONCERN IS TSTM CHANCES.
CURRENT SURFACE ANALYSIS INDICATES AREA OF THUNDERSTORMS ACROSS NW
MN MOVING EAST-NORTHEAST. CAPES RANGE FROM 2500-4000 WITH THE
STORMS WITH THE STRONGEST STORMS JUST EAST OF FARGO. SHEAR IS
WEAKER TOWARD THE WESTERN AREAS OF THE FORECAST AREA BUT CAPES ARE
STILL ON THE HIGH SIDE ALONG WITH PLENTY OF MOISTURE. THE PRECIP
AREA HAS STARTED TO CLIP NW KOOCHCHING COUNTY AND WILL SPREAD EAST
EARLY THIS MORNING. THE PRECIP WILL DECREASE IN INTENSITY AND
COVERAGE AS IT MOVES THROUGH NE MN.
THE NEXT CONCERN FOR THE SHORT TERM IS THUNDERSTORM DEVELOPMENT
THIS AFTERNOON. THERE WILL BE SOME DEBRIS CLOUDS LEFT OVER FROM
THIS MORNING`S STORMS ACROSS NW MN. THE QUESTION FOR THE FORECAST
IS HOW MUCH SUN WILL BE SEEN LATE THIS MORNING AND THIS AFTERNOON.
BASED ON CURRENT TRENDS...THERE COULD BE SOME SUN THIS AFTERNOON
ACROSS EASTERN PORTIONS OF NE MN AND ALL NW WI. THIS WILL INCREASE
THE INSTABILITY THIS AFTERNOON OVER THAT REGION SO WILL KEEP
CURRENT POPS FOR TSTMS. SPC HAS THE SOUTHERN TIER OF NW WI
COUNTIES IN A SLIGHT RISK AREA FOR THIS AFTERNOON AND TONIGHT.
WEAK HIGH PRESSURE WILL BUILD INTO THE WESTERN PORTION OF MN AREA
TONIGHT ENDING THE PRECIP TONIGHT AND WEDNESDAY. THE ONLY
EXCEPTION WILL BE OVER THE ARROWHEAD WHERE THE TROUGH WILL KEEP
THE POSSIBILITY OF THUNDERSTORMS ACROSS THAT REGION THROUGH
THURSDAY.
LONG TERM...THURSDAY NIGHT THROUGH TUESDAY
THURSDAY NIGHT AND FRIDAY WE WILL HAVE A STATIONARY FRONT DRAPED
ACROSS THE ARROWHEAD REGION. THIS WILL BE ASSOCIATED WITH SOME
CHANNELED VORT MAXES IN THE STRONG NORTHWEST FLOW OVER THE
REGION...ON THE BACK SIDE OF THE UPPER LEVEL TROUGH OVER THE EAST
COAST AND THE STRONG RIDGE OVER THE ROCKIES. THIS WARRANTS SOME
HIGH CHANCE TO LOW END LIKELY POPS OVER THE ARROWHEAD REGION
THURSDAY NIGHT AND FRIDAY...ALONG WITH COOLER FRIDAY HIGHS IN THE
LOW 70S. ELSEWHERE HIGHS SHOULD RISE INTO THE MID TO UPPER 70S.
FRIDAY NIGHT AND SATURDAY THE FRONT IS PUSHED SOUTH AS A COLD FRONT
ALONG WITH A MORE VIGOROUS SHORTWAVE THAT DIGS DOWN ACROSS MN AND
WI. THIS SHIFTS OUR POPS SOUTH ACROSS THE REGION...HAVE HAVE PUT
MAINLY CHANCE POPS THROUGH THE PERIOD. SATURDAY LOOKS COOLER WITH
HIGHS ONLY IN THE LOW TO MID 70S...DEPENDING ON HOW MUCH SUNSHINE
CAN GET THROUGH.
SATURDAY NIGHT THROUGH SUNDAY AND INTO MONDAY WE MOVE INTO A DRY
PERIOD AS THE SHORTWAVE THAT MOVED THROUGH ON SATURDAY DIGS SOUTH
AND LEAVES US WITH SOME RIDGING ALOFT AND WEAK RIDGING AT THE
SURFACE AS WELL. THE SHORTWAVE EVENTUALLY CUTS OFF OVER THE DEEP
SOUTH STATES...AND TOGETHER WITH THE RIDGE OUT WEST REALLY SLOWS
DOWN OUR UPPER LEVEL PATTERN. THUS...WHILE I DO HAVE SOME SMALL
CHANCE POPS OUT FOR LATER MONDAY THROUGH TUESDAY...THEY ARE PRETTY
MINOR AND CONFIDENCE IS NOT TERRIBLY HIGH. HIGHS SHOULD RISE UP
INTO THE UPPER 70S TO NEAR 80.
&&
.POINT TEMPS/POPS...
DLH 59 80 57 75 / 30 40 10 40
INL 60 79 58 75 / 30 40 20 40
BRD 62 81 60 79 / 20 10 10 20
HYR 61 80 57 77 / 40 40 10 40
ASX 56 76 56 72 / 50 30 20 70
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
AVIATION...GRANING
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
307 PM EDT WED JUN 26 2013
.SYNOPSIS...
INCREASINGLY UNSETTLED WEATHER IS EXPECTED FOR THE REMAINDER OF
THE WEEK INTO THE WEEKEND AS LOWER PRESSURE ALOFT DEEPENS OVER
THE REGION. SHOWERS AND THUNDERSTORMS WILL FIRE EACH DAY ALONG
AN INLAND SURFACE TROUGH...AS WELL AS THE SEA BREEZE. DAYTIME
AND NIGHTTIME TEMPERATURES WILL HOLD CLOSE TO NORMAL FOR LATE
JUNE TO EARLY JULY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM WEDNESDAY...CONVECTIVE CLUSTER TRACKING EASTWARD ALONG
A SEA-BREEZE FRONT OVER BRUNSWICK COUNTY WILL BE MONITORED CLOSELY
IN THE VERY NEAR TERM. SPS HAS HIGHLIGHTED OUR AREA FOR ISOLATED
SEVERE STORMS AIDED BY CONVERGENCE BUT A WATCH APPEARS UNLIKELY.
OTHER CELLS COULD THREATEN OUR NORTHERN ZONES FROM RED SPRINGS TO
ELIZABETHTOWN THROUGH AFTERNOON. WEST OF ALL THIS ACTIVITY THERE
APPEARS TO BE ONLY ISOLATED CONVECTION DUE TO SUBSIDENCE BEHIND
THE SHORT WAVE IMPULSE LIKELY RESPONSIBLE FOR THE CURRENT
CONVECTION. DIURNAL COOLING IN EARLY EVENING SHOULD ALLOW CELLS TO
ABATE IN COVERAGE AND INTENSITY. LOWS OVERNIGHT LOW TO MIDDLE 70S
EXPECTED WITH LOW-LEVEL WINDS STAYING UP A BIT OVERNIGHT.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...BERMUDA HIGH AND PIEDMONT TROUGH CONTINUE
TO BE THE MAIN SURFACE FEATURES WHILE ALOFT WEAK LONGWAVE 5H
TROUGH REPLACES FLAT RIDGING. MID LEVEL HEIGHT FALLS COMBINED WITH
INCREASING LOW LEVEL THICKNESS LEADS TO AN INCREASE IN INSTABILITY
DURING THE PERIOD. DEEP MOISTURE IN PLACE THU...PRECIPITABLE WATER
VALUES APPROACH 2 INCHES...DECREASES A LITTLE FRI...PWATS DROP
CLOSER TO 1.6 INCH IN THE AFTERNOON...AS MID LEVEL TROUGH AXIS
SHIFTS EAST. BRIEF PERIOD OF DEEP WEST TO NORTHWEST FLOW FRI
AFTERNOON AND EVENING WILL HELP LIMIT CONVECTION BUT STRENGTHENED
PIEDMONT TROUGH MAY OFFSET THE WEAK MID LEVEL SUBSIDENCE.
SEA BREEZE AND PIEDMONT TROUGH SHOULD BOTH BE ACTIVE EACH
AFTERNOON WITH SEA BREEZE BEING HELD CLOSER TO THE COAST BY MORE
WESTERLY FLOW...ESPECIALLY FRI. GIVEN THE LACK OF ANY SIGNIFICANT
INTENSIFYING MID LEVEL FEATURES AND POTENTIAL FOR NUMEROUS
OUTFLOWS DO NOT THINK COVERAGE CAN BE CONFINED TO ONE LOCATION.
COASTAL AREAS ARE LIKELY FAVORED EARLIER IN THE DAY WITH HIGH POP
SHIFTING INLAND LATER IN THE DAY AS PIEDMONT TROUGH ACTIVITY MOVES
INTO THE REGION. HEAVY RAIN REMAINS A CONCERN...ESPECIALLY WITH
TRAINING STORMS...BUT CANNOT RULE OUT A WET MICROBURST OR HAIL
GIVEN THE COOLING MID LEVELS.
TEMPERATURES WILL BE NEAR TO ABOVE CLIMO WITH HIGHS IN THE UPPER
80S TO LOWER 90S AND LOWS IN THE LOW TO MID 70S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 3 PM WEDNESDAY...DEEP SOUTHERLY FLOW OF WARM AND MOIST AIR
WILL CONTINUE THROUGH THE WEEKEND INTO NEXT WEEK AS LOCAL AREA
REMAINS ON THE WESTERN PERIPHERY OF BERMUDA RIDGE AND EASTERN EDGE
OF MID TO UPPER TROUGH TO OUR WEST. A MID TO UPPER LOW ROTATES
AROUND THE GREAT LAKES AND DIGS DOWN THROUGH THE OHIO VALLEY INTO
THE LOWER MISSISSIPPI VALLEY THROUGH THE WEEKEND INTO EARLY NEXT
WEEK. MID TO UPPER LEVEL ENERGY WILL ROTATE AROUND THIS TROUGH UP
THROUGH OUR LOCAL AREA PROVIDING ADDITIONAL SUPPORT TO ENHANCE
CONVECTION OVER THE EASTERN CAROLINAS OVER THE WEEKEND INTO EARLY
NEXT WEEK. BASICALLY WILL CONTINUE WITH WARM AND HUMID AIR MASS
OVER THE AREA WITH PLENTY OF CLOUDS AND AND CHANCE OF SHWRS/TSTMS
EACH DAY. PCP WATER VALUES REMAIN NEAR 2 INCHES OR GREATER THROUGH
MOST OF THE PERIOD. MOISTURE PROFILES SHOW VERY DEEP MOISTURE WITH
RH VALUES GREATER THAN 90% THROUGH MOST LEVELS ABOVE 10K FT. TEMPS
WILL RUN NEAR OR ABOVE NORMAL THROUGH THE PERIOD WITH 70S FOR
OVERNIGHT LOWS AND CLOSE TO 90 FOR AFTERNOON HIGHS.
BY MID WEEK NEXT WEEK THE MID TO UPPER TROUGH OVER THE MID SECTIONS
OF THE CONUS RETROGRADES AND WEAKENS ALLOWING FOR A STRONG RIDGE
OVER THE ATLANTIC TO BUILD WESTWARD INTO THE AREA. THIS SHOULD
PROVIDE DRYING THROUGH THE MID TO UPPER LEVELS AND INCREASED
SUBSIDENCE LEADING TO DRIER WEATHER BY WED OR THURS TIME FRAME.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
AS OF 17Z...WATER VAPOR IMAGERY SHOWS AN UPPER IMPULSE APPROACHING
OUR SOUTHERN TERMS...AND SOME WEAK CONVECTION HAS ALREADY DEVELOPED
WEST OF OUR CWA THIS MORNING. HAVE INCLUDED VCTS FOR ALL TERMS THIS
AFTN AS ISO STORMS ARE EXPECTED TO FIRE ALONG THE DEVELOPING SEA
BREEZE SHORTLY. THE LATEST HRRR RUNS INDICATE THE WESTERLY STEERING
FLOW MAY KEEP SEA BREEZE STORMS PINNED NEAR THE COAST. CONVECTION IS
POSSIBLE INLAND AS WELL AS THE UPPER IMPULSE NEARS OUR WESTERN
TERMS. EXPECT PREVAILING VFR AT ALL TERMS WITH BRIEF PERIODS OF
MVFR/IFR IN +SHRA/TSRA...AND PERHAPS BETTER PCPN COVERAGE AT
KFLO/KMYR/KCRE.
CONVECTION SHOULD RAPIDLY DIMINISH AFTER 00Z. CANNOT RULE OUT
POCKETS OF FOG/STRATUS OVERNIGHT...BUT GIVEN STRONG LOW-LEVEL WINDS
AND LACK OF DEVELOPMENT THIS MORNING...CONFIDENCE IS LOW ATTM. AN
APPROACHING SHORTWAVE/SFC TROUGH ON THURSDAY MAY BRING MORE
WIDESPREAD SHOWERS/T-STORMS TO OUR AREA.
EXTENDED OUTLOOK...ISO/SCT AFTERNOON SHOWERS AND T-STORMS THROUGH
MONDAY WITH BRIEF LOCALIZED PERIODS OF MVFR/IFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM WEDNESDAY...SW FLOW TO PICK UP A BIT AS LOW PRESSURE
INLAND DEEPENS A BIT...AND SW 15-20 KT IS EXPECTED REMAINDER OF
THE AFTERNOON AND OVERNIGHT INTO EARLY THURSDAY. SEAS 3-4 FEET
EXPECTED IN A MIX OF 3 FOOT SSW WAVES EVERY 5 SECONDS AND SE WAVES
1-2 FEET EVERY 8-9 SECONDS. TSTMS WILL BE POSSIBLE ON THE WATERS
THROUGH DAYBREAK THURSDAY.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...SOUTHWEST FLOW WILL CONTINUE THROUGH THE
PERIOD AS WATERS REMAIN BETWEEN BERMUDA HIGH AND STRENGTHENING
PIEDMONT TROUGH. WIND SPEEDS WILL INCREASE AS TROUGH BECOMES MORE
DEFINED THU INTO FRI. WINDS INCREASE FROM 15 TO 20 KT THU TO A SOLID
20 KT FOR FRI. IN RESPONSE TO INCREASING WINDS SEAS WILL BUILD FROM
3 TO 5 FT ON THU TO 3 TO 6 FT LATE THU NIGHT THROUGH FRI NIGHT.
HIGHEST SEAS WILL BE NEAR 20 NM AND IN AREAS OPEN TO EXTENDED
SOUTHWEST FETCH...MAINLY IN AND AROUND FRYING PAN SHOALS.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 3 PM WEDNESDAY...SOUTHERLY FLOW WILL CONTINUE AROUND
WESTERN PERIPHERY OF BERMUDA HIGH THROUGH THE WEEKEND INTO EARLY
NEXT WEEK. WINDS WILL GENERALLY BE 10 TO 15 KTS WITH A SPIKE UP
EACH AFTN IN SEA BREEZE. PERSISTENT SOUTHERLY FLOW WILL KEEP SEAS
UP AROUND 4 TO 6 FT THROUGH THE PERIOD. MAY END UP WITH AN
EXTENDED PERIOD WITH A SMALL CRAFT ADVISORY FOR 6 FT SEAS IN
STRONGER SOUTHERLY FLOW ESPECIALLY IN OUTER WATERS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...COLBY
SHORT TERM...III
LONG TERM...RGZ
AVIATION...BJR/COLBY
AREA FORECAST DISCUSSION...COR
NWS WILMINGTON NC
107 PM EDT WED JUN 26 2013
.SYNOPSIS...
INCREASINGLY UNSETTLED WEATHER IS EXPECTED FOR THE REMAINDER OF
THE WEEK INTO THE WEEKEND AS LOWER PRESSURE ALOFT DEEPENS OVER
THE REGION. SHOWERS AND THUNDERSTORMS WILL FIRE EACH DAY ALONG
AN INLAND SURFACE TROUGH...AS WELL AS THE SEA BREEZE. DAYTIME
AND NIGHTTIME TEMPERATURES WILL HOLD CLOSE TO NORMAL FOR LATE
JUNE TO EARLY JULY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 10 AM WEDNESDAY...STEERING FLOW TODAY WILL GUIDE CONVECTION
TO THE E-ESE AROUND 15 MPH. SUBTLE SHORT-WAVE IMPULSES EXTENDING
FROM WESTERN VA/NC INTO CENTRAL SC EVIDENT IN WATER VAPOR PICTURES
FROM SPACE APPEARS TO BE AIDING MODERATELY STRONG CONVECTION
PRESENTLY SOUTH OF COLUMBIA SC THIS MORNING...AND THIS WILL LIKELY
STIR UP ACTIVITY OVER OUR W AND SW ZONES INTO THE LATE MORNING AND
EARLY AFTERNOON. LATEST 12Z RAOB DATA SHOWS MINOR CAPS ALOFT AT
725MB 600MB AND 475MB...BUT THEY ARE WEAK AND SEE NO REASON WHY
THESE SMALL BARRIERS CANNOT BE ERODED BY UPDRAFTS LATER TODAY.
THIS MAY BE PARTICULARLY TRUE WITH PWAT VALUES AROUND 1.85 INCHES
TODAY. THUS WE ALSO EXPECT CONVECTION TO FIRE ALONG THE INLAND
MARCHING SEA-BREEZE FRONT DURING THE AFTERNOON. RADAR TRENDS AND
WPC QPF DEPICTIONS POINT TO POTENTIALLY HEFTY RAINFALL AMOUNT
FAVORED OVER WILLIAMSBURG AND GEORGETOWN COUNTIES SOUTHWARD INTO
THE CHS FORECAST ZONES. FORTUNATELY THE STORM MOTION DOES NOT
POSE AN OVERBEARING FLOOD THREAT...BUT GROUNDS DO REMAIN WET.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
AS OF 3 AM WEDNESDAY... MID LEVEL TROUGHINESS DROPS INTO THE EASTERN
U.S. ON THURSDAY. LOCAL STEERING FLOW TURNS TO THE WNW AND BL SWRLY
FLOW INCREASES. SEA BREEZE NOT EXPECTED TO MAKE MUCH INLAND PROGRESS
AND STORMS MAY FIRE JUST ABOUT ANYWHERE. SEABREEZE STORMS WILL BE
ABLE TO AFFECT AREA BEACHES. SHORTWAVE PROGGED TO CROSS THE REGION
DURING THE AFTERNOON AND EVENING WHICH MAY ENHANCE TSTM COVERAGE. PW
REMAINS ABOVE 2 INCHES AND SO STORMS WILL YIELD HEAVY RAINFALL.
STORM MOTION WILL BE NEARLY DOUBLE THAT OF DAYS PRIOR TO HOPEFULLY
MITIGATE FLOODING POTENTIAL EXCEPT WHERE ANY TRAINING OCCURS. WET
DOWNBURST HARD TO RULE OUT AS WELL SINCE MLCAPE MAY BE IN THE
1000-1500 J/KG RANGE ON THURSDAY AND POSSIBLY OVER 2000 J/KG ON
FRIDAY. FRIDAY ALSO LOOKS QUITE ACTIVE WHILE NO APPRECIABLE
SHORTWAVES APPEAR IN THE MODELS A WELL DEFINED PIEDMONT TROUGH WILL
BE IN PLACE. ALTHOUGH THIS FEATURE WILL BE TO OUR WEST STORMS WILL
ONCE AGAIN PROPAGATE EASTWARD. BETWEEN THOSE STORMS THAT GET WESTERN
ZONES AND ANOTHER DAY OF AN ACTIVE SEABREEZE ITS HARD TO PICK OUT
ANY FAVORED AREAS FOR TSTMS...MADE EVEN MORE TRUE BY THE NUMEROUS
OUTFLOW BOUNDARIES THAT MAY LINGER FROM THURSDAY STORMS.
TEMPERATURES WILL BE VERY NEAR CLIMO THROUGH THE PERIOD.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 3 AM WEDNESDAY...A COLD FRONT WILL LIE STALLED OVER THE
WESTERN CAROLINAS FOR MOST OF THE PERIOD AS UPPER LEVEL PATTERN
AMPLIFICATION HOLDS UP ANY EASTWARD PROGRESSION. RIDGES OVER WEST
ATLANTIC AND JUST WEST OF THE ROCKIES WITH A TROUGH FROM GREAT LAKES
TO LOWER MS. CAROLINA COASTS WILL REMAIN IN THE DEEP SSWRLY MOISTURE
FLOW AHEAD OF THE BOUNDARY AND BE QUITE PRONE TO FAIRLY WIDESPREAD
SHOWERS AND THUNDERSTORMS. AT THIS POINT ITS HARD TO TELL IF ANY
GIVEN DAY OF THE EXTENDED HAS ANY HIGHER OR LOWER RAIN CHANCES THAN
THE OTHERS. TEMPERATURES WILL BE VERY CLOSE TO CLIMO BUT INCREASING
CLOUD COVER COULD TRIM A FEW DEGREES FROM HIGHS WHILE ADDING THE
SAME TO LOWS.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 17Z...WATER VAPOR IMAGERY SHOWS AN UPPER IMPULSE APPROACHING
OUR SOUTHERN TERMS...AND SOME WEAK CONVECTION HAS ALREADY DEVELOPED
WEST OF OUR CWA THIS MORNING. HAVE INCLUDED VCTS FOR ALL TERMS THIS
AFTN AS ISO STORMS ARE EXPECTED TO FIRE ALONG THE DEVELOPING SEA
BREEZE SHORTLY. THE LATEST HRRR RUNS INDICATE THE WESTERLY STEERING
FLOW MAY KEEP SEA BREEZE STORMS PINNED NEAR THE COAST. CONVECTION IS
POSSIBLE INLAND AS WELL AS THE UPPER IMPULSE NEARS OUR WESTERN
TERMS. EXPECT PREVAILING VFR AT ALL TERMS WITH BRIEF PERIODS OF
MVFR/IFR IN +SHRA/TSRA...AND PERHAPS BETTER PCPN COVERAGE AT
KFLO/KMYR/KCRE.
CONVECTION SHOULD RAPIDLY DIMINISH AFTER 00Z. CANNOT RULE OUT
POCKETS OF FOG/STRATUS OVERNIGHT...BUT GIVEN STRONG LOW-LEVEL WINDS
AND LACK OF DEVELOPMENT THIS MORNING...CONFIDENCE IS LOW ATTM. AN
APPROACHING SHORTWAVE/SFC TROUGH ON THURSDAY MAY BRING MORE
WIDESPREAD SHOWERS/T-STORMS TO OUR AREA.
EXTENDED OUTLOOK...ISO/SCT AFTERNOON SHOWERS AND T-STORMS THROUGH
MONDAY WITH BRIEF LOCALIZED PERIODS OF MVFR/IFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 10 AM WEDNESDAY...SW WIND SPEEDS 15 KT EXPECTED TODAY. THE
SEA BREEZE CIRCULATION WILL PUSH NEARSHORE WIND SPEEDS TO 15 TO 20
KT IN THE MID AFTERNOON THROUGH EARLY EVENING. SEA HEIGHTS WILL
RUN 3 TO 4 FT...IN A MIX OF SSW WIND WAVES 2-3 FEET EVERY 5 SEC
AND SE WAVES 1-2 FEET EVERY 8 SEC. A FEW TSTMS WILL BE POSSIBLE
LATER THIS AFTERNOON INTO THIS EVENING...AS THE STEERING FLOW
PUSHES TSTMS GENERALLY WEST TO E-ESE.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...PIEDMONT TROUGH DEVELOPS ON THURSDAY AND
STRENGTHENS THURSDAY NIGHT. SWRLY GRADIENT WINDS TO INCREASE AND
THE RESULTING SEAS COULD YIELD SMALL CRAFT ADVISORY FOR 6 FT SEAS
OVER NRN ZONES. THE BOUNDARY WILL REMAIN TO OUR WEST INTO FRIDAY
AND HIGH PRESSURE REMAINS ANCHORED ACROSS MUCH OF THE WEST
ATLANTIC. LITTLE IF ANY CHANGES THUS EXPECTED IN WINDS AND SEAS.
SOUTHERN ZONES MAY STAY CAPPED AT 5 FT SEAS AND SCEC MAY OR MAY
NOT BE NEEDED...PERHAPS HINGING ON HOW MUCH SWELL ENERGY MAKES IT
INTO THE FORECAST ZONES.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 AM WEDNESDAY...THE WEEKEND LOOKS TO OFFER UNSETTLED
CONDITIONS CONTINUING FROM THOSE OF THE SHORT TERM. SQUEEZE PLAY
BETWEEN PIEDMONT TROUGH OVER LAND AND STRONG WEST ATLANTIC HIGH TO
KEEP WIND AND SEAS AGITATED MORE THAN TYPICAL OF START OF JULY.
NORTHERN ZONES PROBABLY LOOKING AT CONTINUATION OF LONG DURATION
ADVISORY WHILE SOUTHERN ZONES CLOSER TO CUSP OF ADVISORY VS JUST
SCEC HEADLINES. SOME 6FT SWELL ENERGY COULD MAKE IT INTO SC
WATERS...ITS A LITTLE TOO EARLY TO TELL.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...COLBY
SHORT TERM...BACON
LONG TERM...MBB
AVIATION...BJR/COLBY
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
225 PM CDT WED JUN 26 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 225 PM CDT WED JUN 26 2013
THIS EVENING...FORCING FROM APPROACHING SHORTWAVE CAN BE SEEN IN
RADAR IMAGERY WITH WEAK RETURNS ACROSS CENTRAL NORTH DAKOTA.
RAP/HRRR ALSO INDICATE A WEAK 925MB LOW THAT WOULD PROPAGATE FROM
NW ND INTO SE ND THROUGH THE EVENING HOURS. LAPS ANALYSIS
INDICATES MLCAPE 1000-2000 J/KG...AND DEEP LAYER SHEAR APPROACHING
50 KNOTS. THERE HAS BEEN SOME DRYING OF THE DEW POINTS ACROSS
EASTERN NORTH DAKOTA...BUT THIS HAS HALTED AND VALUES HAVE RISEN A
DEGREE OR TWO THE PAST HOUR. LOW LEVEL CONVERGENCE IS RATHER
WEAK...WHICH WILL LIMIT AREAL COVERAGE. HOWEVER...THERE IS ENOUGH
SUPPORT IN PLACE FOR AT LEAST A COUPLE STRONGER STORMS (MAIN
THREAT LARGE HAIL AND STRONG WIND GUSTS).
THURSDAY-THURSDAY NIGHT...UPPER RIDGE WILL BEGIN TO BUILD ACROSS
THE WESTERN CONUS AND DEVELOP NORTHWEST FLOW ALOFT OVER THE
REGION. COOL AIR ALOFT AND A WEAK MID-LEVEL TROUGH COULD LEAD TO
AFTERNOON SHOWERS ACROSS NW MN. OTHERWISE...BREEZY AFTERNOON WINDS
AND TEMPERATURES NEAR NORMAL.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 225 PM CDT WED JUN 26 2013
FRIDAY-SATURDAY...WESTERN CONUS RIDGE WILL CONTINUE TO BUILD AND
DEVELOP MORE NORTHERLY FLOW ALOFT. A FEW SHORTWAVES WILL MOVE
THROUGH THE REGION...BRINGING SCATTERED SHOWER CHANCES (AND
PROBABLY THUNDER SINCE THERE WILL LIKELY BE SOME INSTABILITY).
TEMPERATURES WILL BE A BIT COOLER.
SATURDAY NIGHT-WEDNESDAY...THERE IS GENERAL AGREEMENT AMONG
MODELS WITH AN AMPLIFYING MID/UPPER LEVEL RIDGE ACROSS THE WESTERN
CONUS EARLY IN THE PERIOD...WITH NORTHWEST FLOW ALOFT ACROSS THE
NORTHERN PLAINS. MAINLY DRY AND SEASONABLE CONDITIONS ARE EXPECTED
FOR SUNDAY WITH WEAK SFC HIGH PRESSURE IN PLACE. BEYOND
SUNDAY...THE PRIMARY CHALLENGE WILL BE CONVECTIVE CHANCES WITHIN
THE NW FLOW PATTERN. MOST MODEL GUIDANCE SUGGESTS SOME EMBEDDED
WAVES DROPPING SOUTH DURING THE MONDAY-WEDNESDAY PERIOD...WITH
PERIODIC CHANCES FOR PRECIPITATION. THE 00Z ECMWF WAS A BIT
FARTHER EAST WITH THE RIDGE AXIS...WHICH WOULD RESULT IN A DRIER
PATTERN OVER THE AREA. THUS...KEPT SLIGHT/CHANCE ALLBLEND POPS
GOING AS MODEL UNCERTAINTY INCREASES LATER IN THE PERIOD.
TEMPERATURES ARE EXPECTED TO REMAIN FAIRLY SEASONABLE THROUGH THE
PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1255 PM CDT WED JUN 26 2013
SCT TO BKN MAINLY VFR CU FIELD WILL CONTINUE THROUGH THE
AFTERNOON...WITH CIGS OCCASIONALLY DROPPING INTO THE MVFR RANGE
ESPECIALLY EAST OF THE VALLEY. DID UTILIZE 15Z HRRR TO INCLUDE MOST
PROBABLE TIME PERIOD FOR CONVECTIVE ACTIVITY WITH THE PASSAGE OF A
SFC TROUGH THIS AFTERNOON/EVENING. WITH SCATTERED NATURE OF
ACTIVITY...WENT WITH VCTS FOR NOW. WEST WINDS THIS AFTERNOON WILL
SUBSIDE THIS EVENING...BEFORE INCREASING AGAIN OUT OF THE WEST TO
NORTHWEST BY MID TO LATE MORNING THURSDAY.
&&
.HYDROLOGY...
ISSUED AT 1255 PM CDT WED JUN 26 2013
ALL RIVERS AROUND FARGO ARE SEEING SHARP RISES AT THE PRESENT TIME.
IT APPEARS THAT THE RED AT FARGO WILL APPROACH MAJOR FLOOD STAGE
WITHIN THE NEXT COUPLE OF DAYS. SIMULATIONS INDICATE THAT POINTS
DOWNSTREAM OF FARGO WILL ALSO APPROACH OR EXCEED MINOR FLOOD STAGE
IN SEVERAL DAYS...FROM HALSTAD THROUGH OSLO MN. AN AREAL FLOOD
WARNING REMAINS IN EFFECT FOR WILKIN AND RICHLAND COUNTIES...AND A
FLOOD ADVISORY HAS BEEN POSTED FOR CASS COUNTY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...TG
LONG TERM...TG/MAKOWSKI
AVIATION...MAKOWSKI
HYDROLOGY...WJB
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1255 PM CDT WED JUN 26 2013
.UPDATE...
ISSUED AT 1255 PM CDT WED JUN 26 2013
MAIN CONCERN FOR TODAY WILL BE MARGINAL SEVERE THUNDERSTORM
CHANCES. LAPS ANALYSIS INDICATES MLCAPE ALONG AND WEST OF THE
VALLEY 1000-1500 J/KG...AND 500-1000 J/KG EAST OF THE VALLEY.
THERE HAS NOT YET BEEN ENOUGH HEATING TO BREAK THE CAP...AND THINK
WE SHOULD REMAIN DRY UNTIL AT LEAST MID-AFTERNOON. A BIT MORE
HEATING COMBINED WITH FORCING FROM APPROACHING SHORTWAVE AND JET
STREAK WILL LIKELY LEAD TO CONVECTIVE INITIATION. DEEP LAYER SHEAR
INCREASES TO AROUND 50 KNOTS...WHICH COMBINED WITH THE INSTABILITY
IN PLACE SHOULD LEAD TO A COUPLE STRONGER STORMS. EXPECTED
COVERAGE NOT ENOUGH TO WARRANT A SLIGHT RISK FROM SPC...OR T+ IN
THE GRIDS. PREVIOUS UPDATE APPEARS TO HANDLE THE SITUATION WELL.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 328 AM CDT WED JUN 26 2013
FOR THE REST OF TODAY...THE SURFACE LOW AND ASSOCIATED COLD FRONT
WILL MOVE INTO THE MN ARROWHEAD. A SOMEWHAT DRIER AIR MASS WITH
DEW POINTS IN THE UPPER 50S TO MID 60S WILL MOVE INTO THE REGION.
SHOULD SEE DECREASING CLOUD COVER UNTIL THIS AFTERNOON WITH SOME
THERMAL CU POSSIBLE GIVEN CONVECTIVE TEMPERATURES IN THE MID TO
UPPER 80S. OUTSIDE OF THE NORTHEAST FORECAST AREA...WILL KEEP 20
POPS THROUGH THE DAY FOR A STRAY SHOWER OR THUNDERSTORM.
TEMPERATURES SHOULD BE A TAD COOLER TODAY...ESPECIALLY ACROSS THE
NORTHEAST...BUT WITH NO MAJOR CHANGE IN THE LOW LEVEL THERMAL
PROFILE...AFTERNOON HIGHS WILL STILL REACH INTO THE MID TO UPPER
80S ALONG AND WEST OF THE VALLEY.
SOME AFTERNOON SHOWERS AND THUNDERSTORMS ARE POSSIBLE IN THE LAKE
OF THE WOODS REGION ON THURSDAY...BUT ALL OTHER AREAS SHOULD BE
DRY WITH PARTLY SUNNY SKIES. IT WILL BE A BIT BREEZY FROM THE
NORTHWEST WITH BOUNDARY LAYER WIND FROM 25 TO 30 KTS TO MIX TO
THE SURFACE. HIGHS THURSDAY WILL BE FROM THE LOW TO MID 80S.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 328 AM CDT WED JUN 26 2013
500 HPA FLOW SHIFTS SHARPLY TO THE NORTHWEST BY FRIDAY WITH A
SERIES OF WEAK SHORT-WAVES MOVING THROUGH THE NORTHERN PLAINS. WILL
MAINTAIN 20 TO 40 POPS ACROSS THE NORTHEAST THIRD OF THE FORECAST
AREA...BUT DO NOT ANTICIPATE WIDESPREAD RAINS. BREEZY NORTHWEST
WIND WILL CONTINUE WITH HIGHS IN THE UPPER 70S TO LOWER 80S.
NOT MUCH TIME SPENT ON EXTENDED (SAT-EARLY NEXT WEEK) DUE TO
CURRENT FLOODING ISSUES. 00Z GFS/EURO SHOW UPPER LOW DROPPING INTO
ERN ND/NW MN SATURDAY GIVING CHANCES FOR SOME PRECIPITATION...THEN
EXITING SUNDAY. 00Z GEM IS DRIER. THEREAFTER..MODELS DIVERGE WITH
EURO EXPANDING HEAT RIDGE OVER THE ROCKIES A BIT FARTHER EAST AND
FORCING NEXT SHORT WAVE DUE MON-TUE A BIT FARTHER EAST OVER
NORTHEAST MN. 00Z GFS IS FARTHER WEST WITH RIDGE AND HAS NEXT
SHORT WAVE OVER OUR AREA MON-TUE AND HIGHER PRECIP CHANCES. KEPT
WITH ALL BLEND IDEA OF HAVING 20-30 POPS EARLY NEXT WEEK FOLLOWING
GFS SOLN. BUT CONFIDENCE IS QUITE LOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1255 PM CDT WED JUN 26 2013
SCT TO BKN MAINLY VFR CU FIELD WILL CONTINUE THROUGH THE
AFTERNOON...WITH CIGS OCCASIONALLY DROPPING INTO THE MVFR RANGE
ESPECIALLY EAST OF THE VALLEY. DID UTILIZE 15Z HRRR TO INCLUDE MOST
PROBABLE TIME PERIOD FOR CONVECTIVE ACTIVITY WITH THE PASSAGE OF A
SFC TROUGH THIS AFTERNOON/EVENING. WITH SCATTERED NATURE OF
ACTIVITY...WENT WITH VCTS FOR NOW. WEST WINDS THIS AFTERNOON WILL
SUBSIDE THIS EVENING...BEFORE INCREASING AGAIN OUT OF THE WEST TO
NORTHWEST BY MID TO LATE MORNING THURSDAY.
&&
.HYDROLOGY...
ISSUED AT 1255 PM CDT WED JUN 26 2013
ALL RIVERS AROUND FARGO ARE SEEING SHARP RISES AT THE PRESENT TIME.
IT APPEARS THAT THE RED AT FARGO WILL APPROACH MAJOR FLOOD STAGE
WITHIN THE NEXT COUPLE OF DAYS. SIMULATIONS INDICATE THAT POINTS
DOWNSTREAM OF FARGO WILL ALSO APPROACH OR EXCEED MINOR FLOOD STAGE
IN SEVERAL DAYS...FROM HALSTAD THROUGH OSLO MN. AN AREAL FLOOD
WARNING REMAINS IN EFFECT FOR WILKIN AND RICHLAND COUNTIES...AND A
FLOOD ADVISORY HAS BEEN POSTED FOR CASS COUNTY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...ROGERS
LONG TERM...ROGERS/RIDDLE
AVIATION...MAKOWSKI
HYDROLOGY...WJB
AREA FORECAST DISCUSSION...UPDATED
NWS PENDLETON OR
1032 AM PDT WED JUN 26 2013
UPDATED AVIATION DISCUSSION
.SHORT TERM...
QUICK UPDATE TO THE FORECAST TO INCREASE CLOUDS AND CHANCES OF
PRECIPITATION FOR THIS AFTERNOON. SATELLITE IMAGERY SHOWS THE
PLUME OF PACIFIC MOISTURE STARTING TO BEND BACK TO THE NORTH AS
THE WESTERN US RIDGE BEGINS TO BUILD. A SHORT WAVE IN THIS
SOUTHWESTERLY FLOW IS CAUSING WARM ADVECTION WIDESPREAD CLOUDS TO
FORM OVER THE AREA. VISIBLE SATELLITE IMAGERY DOESN`T SHOW MUCH
HOPE OF SUNSHINE TODAY. THIS WILL LIMIT THE INSTABILITY OVER THE
AREA DESPITE THE ABUNDANT MOISTURE. THUS THERE`S NO THUNDER IN THE
FORECAST FOR NOW BUT WILL HAVE TO MONITOR THIS, ESPECIALLY OVER
CENTRAL OREGON WHERE THE SUN HAS THE BEST CHANCE OF BREAKING
THROUGH THE CLOUDS.
THE HRRR MODEL DOES SHOW SOME LIGHT SHOWERS ASSOCIATED WITH THIS
CLOUD BAND, EVEN OVER THE LOWER BASIN AREA. BUT ALL MODELS AGREE
ON A FAIRLY SHOWERY DAY OVER THE MOUNTAINS. SO I INCREASED
PRECIPITATION CHANCES OVER THE ENTIRE AREA FOR THIS AFTERNOON. RJ
&&
.AVIATION...18Z TAFS...VFR CONDITIONS WILL BE PREVALENT THROUGH
THURSDAY MORNING. LIGHT SHOWERS WILL CONTINUE ACROSS THE AREA
THROUGH AROUND 03Z THIS EVENING AFFECTING ALL TAF SITES WITH VCSH OR
-SHRA EXCEPT KYKM WHICH IS EXPECTED TO REMAIN DRY. DO NOT EXPECT ANY
THUNDERSTORMS TO DEVELOP TODAY. WHILE SHOWERS MAY CREATE BRIEF MVFR
CONDITIONS THIS AFTERNOON, CEILINGS WILL GENERALLY BE BKN-OVC AT
4000-8000 FEET THROUGH 08Z THEN BECOMING SCT-BKN ABOVE 6000 FEET
AGL. SURFACE WINDS ARE EXPECTED TO REMAIN BELOW 15 KTS FOR THE NEXT
24 HOURS. PERRY
&&
.PREV DISCUSSION... /ISSUED 317 AM PDT WED JUN 26 2013/
SHORT TERM...TODAY THROUGH THURSDAY NIGHT...ANIMATED WATER VAPOR
SATELLITE IMAGERY SHOWS A LARGE MID/UPPER LEVEL LOW PRESSURE SYSTEM
NEAR 49N/138W WITH AN UPPER LEVEL JET STREAM ON THE SOUTHERN FLANK
OF THE LOW FEEDING ASSOCIATED SUBTROPICAL MOISTURE TOWARD THE
PACIFIC NORTHWEST. WIND SPEEDS IN THE CORE OF THE JET STREAM AROUND
30000 FEET ARE 125-130 MPH WITH THE NOSE OF THE JET CURRENTLY
LOCATED SQUARELY OVER THE FORECAST AREA. SOUTHWEST FLOW ALOFT
ASSOCIATED WITH THE JET STREAM WILL STEER A DISTURBANCE NOW MAKING
LANDFALL ON THE OREGON COAST ACROSS THE REGION TODAY AND BRING
ISOLATED TO SCATTERED SHOWERS THROUGH THIS AFTERNOON TO THE
MOUNTAINS OF SE WASHINGTON AND NE OREGON, THE FOOTHILLS OF THE BLUE
MOUNTAINS, AND THE EAST SLOPES OF THE CASCADES. THE DISTURBANCE
EXITS INTO IDAHO/MONTANA THIS EVENING FOR DRY CONDITIONS AT LOWER
ELEVATIONS AND DECREASING POPS IN THE BLUE MOUNTAINS AND ALONG THE
CASCADE CRESTS TONIGHT. HEIGHT CONTOURS OF PRESSURE SURFACES IN THE
TROPOSPHERE BEGIN RISING ON THURSDAY INTO FRIDAY BY VIRTUE OF A
MID/UPPER LEVEL RIDGE OF HIGH PRESSURE THAT BUILDS OVER THE PACIFIC
NORTHWEST THROUGH THE WEEKEND WITH THE RIDGE AMPLIFICATION
CONTINUING DIRECTLY OVER THE FORECAST AREA INTO NEXT WEEK. SINKING
AIR ASSOCIATED WITH THE RIDGE WILL INITIATE A STRONG WARMING TREND
TODAY, WHICH WILL PERSIST OVER THE WEEKEND AND WELL INTO NEXT WEEK
THUS PRODUCING WELL ABOVE NORMAL HIGH TEMPERATURES EACH DAY. POLAN
LONG TERM...FRIDAY THROUGH WEDNESDAY...ALL MODELS ARE IN AGREEMENT
IN CONTINUING TO BUILD A STRONG RIDGE OF HIGH PRESSURE INTO THE
PACIFIC NORTHWEST FROM THE GREAT BASIN. CONFIDENCE OF THIS PATTERN
DEVELOPING IS INCREASING AS EACH MODEL RUN CONTINUES TO SHOW THE IT
DEVELOPING. THIS WILL RESULT IN A HEAT WAVE DURING THE EXTENDED
FORECAST PERIOD. EACH DAY WILL BECOME HOTTER THAN THE PREVIOUS FROM
FRIDAY THROUGH WEDNESDAY AS 850 MB TEMPERATURES BECOME WARMER EACH
DAY FROM THE PREVIOUS DAY AND THE CENTER OF THE HIGH PRESSURE RIDGE
BECOMING WELL ESTABLISHED OVER THE PACIFIC NORTHWEST. ON FRIDAY CAN
EXPECT HIGH TEMPERATURES TO CLIMB INTO THE LOWER TO MID 90S IN THE
LOWER ELEVATIONS...WITH UPPER 70S TO MID 80S IN THE MOUNTAINS. THE
WARMING TREND WILL CONTINUE THROUGH THE WEEKEND INTO EARLY NEXT
WEEK. BY TUESDAY 850 MB TEMPERATURES ARE INDICATING MAXIMUM SURFACE
TEMPERATURES TO BE WELL INTO THE MID 90S TO MID 100S...WITH MID 80S
TO MID 90S IN THE MOUNTAINS. THE GFS MODEL IS FORECASTING AN 850 MB
TEMPERATURE OF 31 OVER PENDLETON ON TUESDAY WHICH WHEN TRANSLATED TO
THE SURFACE IS A TEMPERATURE NEAR 110. HOWEVER...IT IS A BIT TOO
EARLY TO BELIEVE THE MODEL THAT FAR OUT IN TIME...BUT NEVERTHELESS
CONFIDENCE IS INCREASING THAT IT WILL BECOME DANGEROUSLY HOT BY
MONDAY THROUGH WEDNESDAY. THE HOT SURFACE TEMPERATURES WILL CREATE
STEEP LAPSE RATES. THERE MAY BE ENOUGH MID LEVEL MOISTURE AS WELL
SUCH THAT ISOLATED AFTERNOON AND EVENING THUNDERSTORMS COULD DEVELOP
BEGINNING FRIDAY AFTERNOON...MAINLY ALONG THE WASHINGTON CASCADES
AND THE EASTERN OREGON/SOUTHEAST WASHINGTON MOUNTAINS. 88
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 77 56 88 60 / 30 20 0 0
ALW 78 60 89 64 / 30 20 0 0
PSC 81 58 89 63 / 20 10 0 0
YKM 79 57 85 62 / 20 10 0 0
HRI 81 57 89 61 / 20 10 0 0
ELN 76 55 85 60 / 30 10 0 0
RDM 75 50 86 52 / 20 10 0 0
LGD 72 52 84 54 / 70 10 0 0
GCD 76 53 87 56 / 60 10 0 0
DLS 79 59 87 61 / 20 10 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
THREAT INDEX
TODAY : GREEN
THURSDAY : GREEN
FRIDAY : GREEN
GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES.
YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
99/99/99
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
231 PM CDT WED JUN 26 2013
.SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT)
ISSUED AT 231 PM CDT WED JUN 26 2013
SURFACE MAP THIS AFTERNOON HAS A COLD FRONT MOVING EAST ACROSS
EASTERN MN/IA. RADAR SHOWING A BROKEN LINE OF THUNDERSTORMS //SOME
FAIRLY INTENSE TO SEVERE AT TIMES// EXTENDING N-S ALONG THIS FRONTAL
BOUNDARY. LITTLE 0-3KM BULK SHEAR NOTED SO MOST OF THESE STORMS ARE
PULSE-TYPE IN NATURE WITH HIGHER-END RAP 0-1KM ML MUCAPE IN THE
3500-4200J/KG RANGE. THIS UNSTABLE AIR IS BEING PRODUCED BY
TEMPERATURES ACROSS THE AREA IN THE 80-85 DEGREE RANGE AND DEW
POINTS IN THE LOWER 70S.
LOOK FOR THIS FRONT TO SLIP EAST INTO CENTRAL WI THIS EVENING...
DRAGGING THE BULK OF THE SHOWERS/THUNDERSTORMS WITH IT. WITH
PRECIPITABLE WATER VALUES STILL SITTING IN THE 1.5-1.8 INCH
RANGE...ANY SHOWER/THUNDERSTORM EARLY THIS EVENING WILL BE CAPABLE
OF TORRENTIAL DOWNPOURS WITH SOME LOCALIZED PONDING OF WATER
POSSIBLE...ESPECIALLY ACROSS AREAS THAT RECEIVED PREVIOUS HEAVY RAIN
AND HAVE ALREADY SATURATED SOILS.
INTRODUCED A SLIGHT CHANCE OF SHOWER/THUNDERSTORMS MAINLY NORTH OF
I-94 LATER OVERNIGHT//AFTER 09Z// AS A MID-LEVEL TROUGH AND LEFT
EXIT REGION OF 75-100KT 300MB JET PUSHES INTO THIS AREA. MOST OF
THIS ACTIVITY LOOKS ELEVATED/ACCAS TYPE IN NATURE. BUFKIT SHOWS
DRYING IN THE LOWER LEVELS...SO NOT CONFIDENT ON HOW MUCH RAINFALL
WILL ACTUALLY REACH THE SURFACE. THEREFORE...WILL KEEP POPS ON THE
LOW SIDE FOR NOW. THIS MID-LEVEL WAVE CONTINUES TO MOVE ACROSS THE
AREA ON THURSDAY FOR A CONTINUED CHANCE OF SHOWERS AND
THUNDERSTORMS...MAINLY ALONG AND EAST OF THE MISSISSIPPI RIVER. MAY
HAVE TO WATCH THIS CONVECTION CLOSELY FOR SEVERE WIND/HAIL THREAT
GIVEN STEEPER LAPSE RATES AND 0-6KM BULK SHEAR IN THE 35-45KT RANGE.
THE GFS... WHICH IS THE DRIEST OF THE MODELS AS FAR AS
DEWPOINTS...YIELDS 0-1KM MLCAPE IN THE 1000-1500J/KG RANGE. IN
ADDITION...MAY HAVE SOME ADDED LIFT DUE TO THE LEFT EXIT REGION OF
75-100KT 300MB JET. OTHERWISE...LOOKING FOR A HIGH IN THE
LOWER/MIDDLE 80S WITH DEW POINTS IN THE MIDDLE 60S.
LOOK FOR THE MID-LEVEL WAVE TO EXIT EAST OF THE REGION BY LATE
THURSDAY EVENING...END THE THUNDERSTORM THREAT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 231 PM CDT WED JUN 26 2013
ON FRIDAY...MODELS IN GOOD AGREEMENT IN SWINGING A MID-LEVEL TROUGH
SOUTHWESTWARD INTO THE AREA FROM THE GREAT LAKES REGION. STEEPENING
LAPSE RATES WITH ASSOCIATED COLDER CYCLONIC FLOW ALOFT EXPECTED TO
PRODUCE SCATTERED TO NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS
MAINLY EAST OF THE MISSISSIPPI RIVER. OTHERWISE...PLAN ON HIGHS
COOLING SOMEWHAT INTO THE MID 70S TO AROUND 80 WITH FAIRLY BREEZY
NORTHWEST WINDS IN THE 10-20 MPH RANGE.
LOOK FOR COOLER CONDITIONS WITH SCATTERED SHOWERS AND ISOLATED
THUNDERSTORM ACTIVITY TO CONTINUE FRIDAY NIGHT THROUGH SATURDAY AS
THE MID-LEVEL TROUGH SWINGS SOUTH THROUGH THE AREA. HIGHS ON
SATURDAY WILL ACTUALLY SLIP SLIGHTLY BELOW NORMAL LEVELS IN THE
LOW-MID 70S. APPEARS SHOWERS WILL BE EXITING THE AREA COMPLETELY BY
SATURDAY EVENING AS THE TROUGH SHIFTS SOUTHEAST TOWARD THE OHIO
RIVER VALLEY AND RIDGING BUILDS IN FROM THE NORTHWEST.
FOR SUNDAY THROUGH WEDNESDAY...PLAN ON COOLER/OVERALL DRIER
CONDITIONS AS A MAJOR MID-LEVEL TROUGH ESTABLISHES ITSELF OVER THE
CENTRAL CONUS WITH A HIGHLY AMPLIFIED RIDGE ACROSS THE WESTERN
CONUS. EC REMAINS DRY DESPITE COOLER CYCLONIC FLOW AND THE GFS IS
LIGHT AND SPOTTY WITH ITS QPF. LOOKS LIKE MAINLY SOME DAYTIME
CUMULUS BUT REMAINING DRY. OTHERWISE...HIGHS ARE EXPECTED TO BE IN
THE 75-80 DEGREE RANGE WITH OVERNIGHT LOWS MAINLY IN THE 50S...VERY
PLEASANT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1230 PM CDT WED JUN 26 2013
A SFC THRU 700MB TROUGH AXIS WAS MOVING EAST ACROSS MN EARLY THIS
AFTERNOON. AHEAD OF THIS TROUGH SOME SCT-BKN DECKS OF MVFR STRATO-CU
HAD SPREAD ACROSS SOUTHEAST MN/WESTERN WI. THESE WILL SLOWLY RAISE
WITH DIURNAL WARMING/MIXING THIS AFTERNOON...BUT PERSIST UNTIL THE
TROUGH AXIS PASSES. A SCT-BKN LINE OF SHRA/TSRA IS EXPECTED TO
DEVELOP ALONG THIS TROUGH AS IT MOVES ACROSS THE AREA...BUT SO FAR
WEST OF THE FCST AREA IT HAS BEEN QUIET. WILL LEAVE TSRA MENTION IN
TAFS THIS AFTERNOON AS VCTS/CB UNTIL CONVECTION STARTS TO DEVELOP.
IF A LINE OF SHRA/TSRA DOES DEVELOP...PLAN ON AN UPDATE OR TWO FOR 1
TO 2 HRS OF TSRA AS THE LINE PUSHES EAST ACROSS THE TAF SITES.
ONCE THE TROUGH PASSES...DRIER AIR WILL START TO SPREAD ACROSS THE
AREA WITH THE LOWER LEVEL WIND FLOW BECOMING WEST AND NORTHWEST.
ENOUGH GRADIENT WIND EXPECTED TONIGHT TO KEEP BR/FG TO A MINIMUM...
THOUGH SOME SPOTTY BR/FG POSSIBLE IN THE MS/WI RIVER VALLEYS. ONLY
MENTIONED A SHORT PERIOD OF BCFG AROUND SUNRISE AT KLSE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...RRS
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 225 PM CDT WED JUN 26 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN ELONGATED
SHORTWAVE TROUGH SPINNING OVER THE LAKE WINNIPEG REGION WHICH ALSO
EXTENDS SOUTH INTO THE NORTHERN MISSISSIPPI VALLEY. ANOTHER
SHORTWAVE IS SPINNING OVER NORTHERN ILLINOIS AND IS HEADING
EAST...SO NOT MUCH IMPACT ACROSS OUR AREA. STORMS FIRED UP AROUND
MIDDAY ALONG A SURFACE TROUGH OVER THE WI/MN BORDER WHERE ML CAPES
ARE REACHING UP TO 2K J/KG. THE FIRST WARNING THIS AFTERNOON WAS
JUST ISSUED A FEW MINUTES AGO...BUT STORMS ARE NOT SHOWING MUCH
ORGANIZATION AND 0-6KM BULK SHEAR VALUES ARE RATHER POOR AT AROUND
20 KTS. WITH SUCH WEAK BULK SHEAR VALUES...THINKING PULSY SEVERE
AT THIS TIME UNLESS STORMS CAN BECOME MORE ORGANIZED. A FEW SPOTTY
SHOWERS TRIED TO DEVELOP OVER NORTH-CENTRAL AND FAR NORTHEAST
WISCONSIN...BUT FIZZLED OUT. SEVERE WEATHER CHANCES ARE THE MAIN
FORECAST CONCERN.
TONIGHT...LATEST TIMING HAS STORMS ARRIVING INTO NORTH-CENTRAL
WISCONSIN AT AROUND 21Z AND PROGRESSING EAST TO NORTHEAST WISCONSIN
BY 00-01Z BEFORE EXITING AFTER 04Z. WITH STORMS ARRIVING AT OR NEAR
PEAK HEATING...SEVERE WEATHER HAS POTENTIAL TO REACH NORTHEAST
WISCONSIN THOUGH CAPES ARE NOT NEARLY AS IMPRESSIVE OVER NORTHEAST
AND EAST-CENTRAL WISCONSIN AS FURTHER WEST. WITH LOSS OF HEATING
AND WEAKER INSTABILITY...THINK SEVERE THREAT OVER THE EASTERN PARTS
OF THE STATE ARE VERY MARGINAL. BETTER CHANCES WILL BE OVER
NORTH-CENTRAL WISCONSIN. ONCE THE STORMS DEPARTS/WEAKEN...RATHER
JUICY AIRMASS WILL LINGER FOR THE REST OF THE NIGHT. AREAS THAT
RECEIVED RAIN WILL BE PRIME CANDIDATES FOR DENSE FOG AND WILL ADD
FOG TO THE FORECAST. LOWS MAINLY IN THE LOW TO MID 60S.
THURSDAY...THE UPPER TROUGH OVER LAKE WINNIPEG WILL SLIDE SOUTHEAST
INTO LAKE SUPERIOR. WILL HAVE SUPPORT IN THE FORM OF UPPER
DIVERGENCE IN THE LEFT FRONT QUAD OF THE JET STREAK FOR MUCH OF THE
DAY...SO CANNOT RULE OUT SPOTTY SHOWERS AND STORMS IN THE MORNING.
BUT THINKING STORMS ARE LIKELY FOR MOST OF NORTH-CENTRAL AND
NORTHEAST WISCONSIN IN THE AFTERNOON...ONCE UPWARDS OF 1500 J/KG OF
ML CAPE CAN DEVELOP ACCORDING TO PROGGED SOUNDINGS. WITH DEEP
MIXING AND 0-6KM BULK SHEAR AROUND 30KTS...THINK SEVERE WEATHER IS
POSSIBLE TOMORROW AFTERNOON. DAMAGING WIND GUSTS AND LARGE HAIL
WILL BE THE MAIN THREATS. SHOULD FEEL LESS HUMID OUT THERE THAN
TODAY...BUT HIGHS SHOULD STILL REACH INTO THE LOW TO MID 80S.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 225 PM CDT WED JUN 26 2013
IN GENERAL...MAINLY DIURNAL CONVECTION ANTICIPATED
WITH AS A SHORT WAVE CARVES OUT A DEEP UPPER TROUGH OVER THE
GREAT LAKES THROUGH EARLY SATURDAY FOLLOWED WITH A TREND FOR DRIER
AND COOLER AIR IN THE NORTH FLOW FOR THE REST OF THE WEEKEND INTO
THE FIRST HALF OF NEXT WEEK.
DIURNAL CONVECTION TO BE ON THE DECREASE THURSDAY NIGHT IN THE
WEAK CYCLONIC FLOW. WILL CONTINUE THE TREND OF MAINLY EVENING
SHOWERS CHANCES FOR MOST LOCATIONS. OTHERWISE SHOWERS WITH
ISOLATED STORMS TO BE ON THE INCREASE AGAIN FRIDAY AS THE COOLER
UPPER TROUGH SLOWLY DRIFTS SOUTHWARD OVER THE GREAT LAKES REGION.
AGAIN A DIURNAL DECREASE MAY OCCUR LATER FRIDAY EVENING...BUT
SHOWER ACTIVITY NOT LIKELY TO END UNTIL THE TROUGH AXIS SHIFTS FAR
ENOUGH SOUTH. THE ECMWF AND GFS WERE THE MOST PROGRESSIVE WITH THE
TROUGH AND PCPN SOUTH OF THE AREA SATURDAY MORNING. THE NAM IS
MUCH SLOWER WITH THE TROUGH PASSAGE AND HANGS ONTO PCPN THROUGH
SATURDAY AFTERNOON.
EVENTUALLY COOLER DRIER ON NORTHERLY WINDS WILL SWEEP SOUTH OVER
THE WESTERN GREAT LAKES LATER SATURDAY THROUGH THE FIRST FEW DAYS
OF THE NEXT WEEK AS THE CANADIAN SURFACE HIGH PRESSURE SETTLES IN.
PCPN CHANCES BEGIN TO RETURN AFTER TUESDAY AS THE GFS PROG THIS
DEEP TROUGH TO CUT OFF INTO AN UPPER LOW AND RETROGRADE BACK INTO
WESTERN GREAT LAKES REGION. THE ECMWF HAS A SIMILAR SOLUTION BUT
DROPS ANOTHER PIECE OF ENERGY INTO THE NORTHERN PLAINS IN THE
NORTHWEST FLOW. RETURN FLOW TUESDAY INTO WEDNESDAY CONFINED TO
THE ROCKIES AND NORTHERN PLAINS SO WILL KEEP POPS ON THE LOW SIDE.
IN ADDITION...ANY CONVECTION WHICH CAN DEVELOP WILL LIKELY BE
DIURNAL.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1238 PM CDT WED JUN 26 2013
SHOWERS AND THUNDERSTORMS OVER THE WI/MN BORDER WILL TRACK EAST
TODAY AND INTO NORTH-CENTRAL WISCONSIN LATER THIS AFTERNOON. OTHER
POP UP STORMS ARE POSSIBLE OVER CENTRAL WISCONSIN TOO...BUT WILL
PROBABLY HAVE TO WAIT UNTIL THIS EVENING FOR STORMS TO REACH EASTERN
WISCONSIN. POTENTIAL IS THERE FOR STRONG GUSTY WINDS AND HEAVY
DOWNPOURS WITHIN ANY THUNDERSTORMS. STORMS WILL EXIT LATE
TONIGHT...BUT THE MOIST AIRMASS WILL LINGER. WITH LIGHT
WINDS...PATCHY DENSE FOG IS POSSIBLE LATE TONIGHT...ESPECIALLY WHERE
IT RAINS. ONCE ANY FOG BURNS OFF BY MID-MORNING...MORE STORMS WILL
BE POSSIBLE TOMORROW AFTERNOON.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......TDH
AVIATION.......MPC