Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/26/14
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATED
NWS LOS ANGELES/OXNARD CA
445 PM PDT FRI JUL 25 2014
...UPDATED AVIATION DISCUSSION...
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN ANCHORED OVER THE DESERT SOUTHWEST THROUGH
THE MIDDLE OF NEXT WEEK RESULTING IN CONTINUED SEASONAL TO ABOVE
NORMAL TEMPERATURES. HIGH CLOUDS WILL STREAM THROUGH THE AREA WITH A
SLIGHT POSSIBILITY OF A THUNDERSTORM OVER THE SAN GABRIELS MAINLY
SUNDAY AFTERNOON. OVERNIGHT LOW CLOUDS AND FOG ARE EXPECTED ALONG
MOST COASTAL AREAS.
&&
.SHORT TERM (REST OF TODAY-MON)...STILL KEEPING AN EYE ON THE LINE
OF THICKER CLOUDS AND ISOLATED CONVECTION INCHING NORTHWARD ON A
LINE FROM JUST NORTH OF LAS VEGAS SOUTHWESTWARD TOWARD JUST SOUTH OF
CATALINA AT THIS TIME. MOST ACTIVE CONVECTION IS IN THE PALM SPRINGS
AREA...OTHERWISE KSOX INDICATING ECHOES OFFSHORE JUST SOUTH OF
CATALINA...ALTHOUGH ONLY WELL ALOFT AT THIS TIME. THIS ACTIVITY IS
IN PART DUE TO A WEAK WAVE APPARENT IN THE FLOW AROUND THE LARGE
HIGH STILL CENTERED OVER THE SOUTHERN HIGH PLAINS. THE RUC MODEL
(PER 400 MB VORT) SORT OF WASHES THIS OUT WITH TIME THIS
EVENING...THOUGH STILL APPARENT. LATEST LIFTED INDEX VALUES STILL
REMAIN LOWEST EAST OF OUR AREA WITH JUST BELOW ZERO VALUES INTO OUR
AREA...BUT FORECAST TO STABILIZE AFTER 21Z. VISIBLE SATELLITE
IMAGERY AND DOWNTOWN LA WEBCAMS SHOW CU TRYING TO BUILD ON THE
NORTHERN EDGE OF THE EASTERN SAN GABRIELS...BUT UPDRAFTS LOOK WEAK
AND DISORGANIZED SO FAR. LATEST HIGH RESOLUTION RAPID REFRESH (HRRR)
MODEL RUN FROM 19Z ALSO KEEPS PRECIPITATION OUT OF OUR AREA. FOR
NOW BELIEVE NOTHING OF SIGNIFICANCE WILL MATERIALIZE FROM THIS OTHER
THAN SOME INCREASING MID AND HIGH CLOUDINESS ACROSS LOS ANGELES AND
PARTS OF VENTURA COUNTIES....BUT WILL CONTINUE TO MONITOR. MAY NEED
TO AT LEAST INCREASE THE FORECAST SKY COVER FOR THIS EVENING OVER
THESE AREAS.
BEYOND THE REST OF THIS AFTERNOON AND EVENING...THE PRIMARY FACTOR
IN THE FORECAST IS THE PERSISTENT HIGH PRESSURE SYSTEM OVER THE
WESTERN U.S. WHICH WILL VARY IN AXIS POSITION AND SHAPE OVER THE
NEXT 7 DAYS. THE RESULT WILL MEAN LITTLE CHANGE IN THE DAY TO DAY
CONDITIONS. AFTERNOON TEMPERATURES WILL CHANGE LITTLE EACH
DAY...REMAINING FROM JUST ABOVE NORMAL VALLEYS AND INLAND...BUT WITH
SOME ONSHORE FLOW THROUGH THE PERIOD...THE COASTAL AREAS WILL REMAIN
AT OR JUST BELOW NORMAL.
EXPECT A SLIGHT INCREASE IN COVERAGE ALONG THE COASTS OF THE
OVERNIGHT CLOUDS AND FOG TONIGHT...AND A REPEAT PERFORMANCE ON
SUNDAY AND MONDAY. WITH THE ONSHORE FLOW COMES GUSTY SOUTHWEST WINDS
EACH AFTERNOON IN THE ANTELOPE VALLEY...BUT STAYING BELOW ADVISORY
CRITERIA.
THE ONE HICCUP IN THE PERSISTENCE FORECAST MAY BE SUNDAY AFTERNOON
AND EVENING IN THE LA AND VTU COUNTY MOUNTAINS AND THE ANTELOPE
VALLEY. SOME INDICATIONS OF SOME CONVECTIVE ACTIVITY THESE AREAS
SUNDAY AFTERNOON. CONVECTIVE PARAMETERS NOT OVERLY IMPRESSIVE OTHER
THAN MODELS INDICATING A POSSIBLE SHORT WAVE THAT ROTATES AROUND THE
SOUTH SIDE OF THE HIGH THEN ROTATES AROUND AND BRUSHES OUR AREA ON
SUNDAY. THIS WILL COME INTO BETTER FOCUS WITH NEW MODEL RUNS BUT
HAVE KEPT THE GOING FORECAST OF A SLIGHT CHANCE OF THUNDER OVER THE
EASTERN SAN GABRIELS FOR NOW.
.LONG TERM (TUE-FRI)...THE UPPER LEVEL HIGH OVER THE WESTERN U.S.
PERSISTS THROUGH THE LONG TERM. THE ONE CHANGE IS THAT IT PUMPS UP
INTO SOUTHWEST CANADA AS OPPOSED TO THE EAST-WEST ELONGATED HIGH
THAT IT`S BEEN AS OF LATE. THE ECMWF PUTS THE HIGH AXIS A LITTLE
FURTHER WEST...THE RESULT BEING AROUND A 585 DM THICKNESS OVER SOCAL
ON WEDN AFTN VERSUS THE 579 DM THICKNESS FORECAST BY THE GFS. THIS
WOULD RESULT IN WARMER TEMPS MIDWEEK. DISCOUNTING THE ECMWF FOR NOW
IN PART SINCE THE OPERATIONAL GFS IS IN LINE WITH THE GFS ENSEMBLES.
SO GOING WITH THE GFS...NOT MUCH CHANGE IN SENSIBLE SURFACE WEATHER
FROM DAY TO DAY. TEMPERATURES JUST ABOVE AVERAGE VALLEYS AND DESERT
AND AT OR JUST BELOW AVERAGE COASTAL AREAS. ONSHORE GRADIENTS WILL
CHANGE LITTLE EACH DAY SO EXPECT SOME OVERNIGHT LOW CLOUDS AND FOG
ALONG THE COASTS...BUT AT THIS TIME WITH NOT MUCH INLAND EXTENT. WE
APPEAR TO BE RIGHT ON THE WESTERN EDGE OF ANY MONSOONAL FLOW SO
DIFFICULT TO TELL AT THIS POINT WHEN WE MAY GET ENOUGH MOISTURE THIS
FAR WEST FOR ANY CONVECTIVE ACTIVITY. AT THIS TIME HAVE NOT INCLUDED
ANY MENTION OF IT DURING THIS PERIOD.
&&
.AVIATION...25/2340Z...
MARINE LAYER CLOUDS EXPECTED TO BE MORE WIDESPREAD TONIGHT ACROSS THE
COASTAL PLAIN AS ONSHORE FLOW STRENGTHENS AND MARINE LAYER DEPTH
INCREASES. LATEST ACARS DATA SHOWING MARINE LAYER DEPTH AROUND 1000
FEET ACROSS THE LA BASIN LATE THIS AFTERNOON...BUT IS EXPECTED TO
DEEPEN TO BETWEEN 1500 AND 1800 FEET BY SATURDAY MORNING. IN 00Z TAF
PACKAGE...HAVE MOVED UP TIMING OF IFR/LOW MVFR CIGS ACROSS MANY OF
THE COASTAL TAF LOCATIONS...AND KEPT CEILINGS LINGERING TO 18Z-19Z
TIME FRAME ON SATURDAY. THERE IS A 20 PERCENT CHANCE THAT IFR CIGS
COULD REACH KBUR AND KVNY BY EARLY SATURDAY MORNING. ALSO A 20 PERCENT
CHANCE OF CIGS LINGERING INTO THE AFTERNOON HOURS ACROSS COASTAL TAF
SITES.
KLAX...MODERATE CONFIDENCE IN THE 00Z TAF. LOW MVFR CIGS EXPECTED
TO RETURN OVERNIGHT INTO SATURDAY MORNING...BUT THERE IS A 20 PERCENT
CHANCE OF CIGS LOWERING INTO IFR CATEGORY BRIEFLY. THERE IS ALSO
A 20 PERCENT CHANCE OF MVFR CIGS LINGERING INTO THE AFTERNOON HOURS
ON SATURDAY.
KBUR...MOSTLY VFR CONDITIONS THROUGH PERIOD...WITH EXCEPTION OF SOME
MVFR VSBYS IN HAZE EARLY SATURDAY MORNING. THERE IS A 20 PERCENT
CHANCE OF BRIEF IFR CIGS ON SATURDAY MORNING.
&&
.MARINE...25/230 PM...
HIGH CONFIDENCE IN CURRENT FORECAST. WINDS AND SEAS ARE CONTINUING
TO DECREASE THOUGH SOME SENSORS INDICATE LOCAL SEA HEIGHTS ARE A BIT
SLOWER TO DECREASE THAN EARLIER EXPECTED... POSSIBLY DUE TO A SMALL
BUMP IN THE WIND WAVES. THEREFORE THE SMALL CRAFT ADVISORY FOR
HAZARDOUS SEAS HAS BEEN EXTENDED INTO THE EVENING HOURS. OTHERWISE
CONDITIONS ARE EXPECTED TO REMAIN BELOW ADVISORY CRITERIA THROUGH
THE REMAINDER OR THE FORECAST PERIOD.
REPORTS OF MOSTLY DRY LIGHTNING TO THE SOUTH AND EAST OF THE
FORECAST AREA TODAY AND ANY FURTHER THUNDERSTORM DEVELOPMENT IS
EXPECTED TO REMAIN OUT OF THE AREA THROUGH TONIGHT. THE BOUNDARY
UPON WHICH THE CONVECTION IS DEVELOPING WILL BE SHIFTING
NORTHWESTWARD THROUGH SUNDAY... HOWEVER... AND MAY MOVE INTO ZONES
676 AND 655 BY SUNDAY.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS (SEE LAXMWWLOX).
&&
$$
PUBLIC...MJ
AVIATION...GOMBERG
MARINE...KJ
SYNOPSIS...MJ
WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1100 PM MDT WED JUL 23 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 308 PM MDT WED JUL 23 2014
BOUNDARY FROM EARLY MORNING CONVECTION ACROSS NORTHEAST COLORADO
HAS PUSHED BACK WESTWARD INTO KIOWA AND NORTHEAST BENT COUNTY AS
OF 1 PM...AND EXTENDS TO THE NORTHEAST TO NEAR KLIC...TO
KDEN...THEN BACK TO THE SOUTHWEST TOWARDS THE NORTHERN BORDER OF
TELLER COUNTY. WHILE WESTERN PORTIONS OF THIS BOUNDARY HAVE
STALLED AND IS BEGINNING TO SHIFT BACK NORTHWARD...EASTERN
PORTIONS OF THIS BOUNDARY CONTINUE TO BACKDOOR WESTWARD INTO THE
SOUTHEAST PLAINS WITH DEW POINTS IN THE 60S BEHIND IT. TO THE
SOUTH OF THIS BOUNDARY...SOUTHERLY WINDS ARE INCREASING...BUT DEW
POINTS HAVE BEEN MORE STUBBORN TO MIX OUT TODAY...AND REMAIN IN
THE 40S AND 50S. STILL THINK THERE IS SOME FURTHER MIXING OUT THAT
WILL OCCUR DURING THE AFTERNOON AND EVENING HOURS...BUT HRRR AND
RAP13 APPEAR TO BE DRYING OUT DEW POINTS TOO VIGOROUSLY...EVEN IN
THE LATEST RUNS. THIS ELEVATES CONCERNS FOR POTENTIAL FOR A SLOW
MOVING THUNDERSTORM TO DEVELOP OVER THE WALDO BURN SCAR SOMETIME
THIS AFTERNOON AND EVENING. ANOTHER AREA OF CONCERN WILL BE ACROSS
THE WEST FORK BURN SCAR....THOUGH LATEST OBS OUT THAT WAY SHOW DEW
POINTS HAVE ALREADY DROPPED INTO THE 30S AND CONVECTION DOES NOT
LOOK ALL THAT STRONG YET. THUS APPEARS MAIN AREA TO MONITOR WILL
BE ACROSS TELLER AND EL PASO COUNTIES THIS EVENING...AND THREAT
AREA MAY END UP BEING JUST TO THE NORTH OF TELLER COUNTY. WILL
ALSO HAVE TO WATCH THE BOUNDARY ACROSS THE FAR SOUTHEAST PLAINS
FOR THUNDERSTORM DEVELOPMENT. MIXED LAYER CAPES ALONG THIS
BOUNDARY ARE AROUND 4000 J/KG OFF THE SPC MESO ANALYSIS...HOWEVER
THERE IS ALSO A FAIR OF CIN BEHIND THE OUTFLOW BOUNDARY AS WELL.
NONE OF THE SHORT RANGE MODELS ARE DEVELOPING THUNDERSTORMS ALONG
THIS BOUNDARY BENEATH THE UPPER HIGH. DEEP LAYER SHEAR IS
WEAK...SO ANY SEVERE POTENTIAL WOULD BE MORE LIKELY TO BE FROM A
PULSE TYPE SEVERE WHICH COULD PERSIST IF A STORM CAN ANCHOR TO THE
BOUNDARY. BUT WITH THE LACK OF FORCING THIS SEEMS TO BE A LOW END
PROBABILITY OF OCCURRENCE. HOWEVER...IT DEFINITELY BEARS WATCHING.
THUNDERSTORMS SHOULD DIMINISH THIS EVENING WITH LOSS OF
HEATING...THOUGH WITH MONSOON PLUME OVER THE MOUNTAINS WILL MAINTAIN
SOME ISOLATED POPS THROUGH THE NIGHT AS IS TYPICAL THIS TIME OF
YEAR.
FOR THURSDAY...UPPER RIDGE FLATTENS WHICH PUTS THE MONSOON PLUME
ALOFT ACROSS MOST OF CO. MODELS SUGGEST A WEAK SHORTWAVE WILL MOVE
OVERTOP THE RIDGE WHICH WILL HELP TO FIRE OFF THUNDERSTORMS ACROSS
THE MOUNTAINS THEN SEND THEM TO THE EAST ACROSS THE ADJACENT PLAINS.
BOTH NAM AND GFS SUGGEST NORTHERN PORTION SO OF THE FORECAST AREA
MAY SEE A BETTER CHANCE FOR THUNDERSTORMS TOMORROW...AND THIS WILL
PUT WALDO UNDER A SLIGHTLY HIGHER THREAT THAN TODAY. AGAIN...DEEP
LAYER SHEARS ARE WEAK...SO THREAT FOR SEVERE WEATHER OVERALL LOOKS
LOW. STORM MOTIONS SHOULD BE A LITTLE FASTER AND TOWARDS THE
EAST...BUT PROBABLY NOT FAST ENOUGH TO MITIGATE THE POTENTIAL
LOCALIZED FLASH FLOODING ON THE BURN SCARS SHOULD THEY TAKE AN
UNLUCKY STRIKE. SO ANOTHER DAY OF MONITORING THE WALDO BURN SCAR
CLOSELY WILL BE IN STORE. STORM STRENGTH WILL DEPEND ON HOW MUCH
SURFACE DEW POINTS MIX OUT...AND WITH WESTERLY FLOW OVER THE
AREA...UPPER 30S TO LOWER 40 DEW POINTS LOOK LIKELY...WHICH SHOULD
KEEP CAPE VALUES GENERALLY BELOW 1000 J/KG. HAVE KEPT HIGHER POPS
ACROSS THE CENTRAL MOUNTAINS AND PIKES PEAK REGION FOR TOMORROW.
OTHERWISE...WESTERLY FLOW SHOULD HELP DRY OUT SURFACE DEW POINTS
ACROSS THE PLAINS...WHICH SHOULD LIMIT CAPE AND THUNDERSTORM
COVERAGE. THIS MAY ALSO BE SUFFICIENT TO BOOST TEMPS INTO THE LOWER
100S ACROSS THE LOWER ARKANSAS RIVER VALLEY. HOWEVER...AN INCREASE
IN CONVECTIVE CLOUD COVER MAY ALSO LIMIT HEATING SOME...ESPECIALLY
FOR THE I-25 CORRIDOR SO HAVE KEPT PUB BELOW THE CENTURY MARK FOR
NOW. LOCATIONS FARTHER EAST SHOULD HAVE AN EASIER TIME OF HITTING
AROUND 100. -KT
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 308 PM MDT WED JUL 23 2014
...MORE MONSOON NEXT WEEK...
THE EXTENDED FORECAST LOOKS PRETTY TYPICAL FOR LATE JULY...AS
AN UPPER RIDGE DOMINATES THE WEATHER THROUGH NEXT WEEK. BUT THERE
WILL BE TWO DISTINCT PATTERNS THAT WILL SHAPE OUR WEATHER.
THE FIRST HALF OF THE PERIOD WILL BE A CONTINUATION OF THE HOT AND
RELATIVELY DRY WEATHER WE HAVE BEEN EXPERIENCING THIS WEEK. A WEAK
FRONTAL SURGE WILL USHER IN A LITTLE MORE UPSLOPE THU NIGHT INTO
FRIDAY...AND THIS MAY HELP GENERATE A FEW MORE SHOWERS AND STORMS
OVER THE AREA FRIDAY AFTERNOON AND EVENING. WE WILL STILL BE UNDER
THE UPPER RIDGE AXIS...AND WITH TEMPS ALOFT STILL PRETTY
HIGH...EXPECT ANOTHER HOT DAY WITH TEMPS SOARING INTO THE HIGH 90S
OVER THE PLAINS. MAYBE EVEN A DEGREE OR TWO HOTTER ON SATURDAY
AS THE RIDGE EXPANDS A BIT TO THE NORTH.
THEN...A FRONTAL SURGE ASSOCIATED WITH A STRONG TROUGH DIGGING
OVER ERN CANADA WILL BRING A CHANGE TO OUR WEATHER BEGINNING
SUNDAY. IT LOOKS SOMEWHAT SIMILAR TO OUR LAST PERIOD OF WET
WEATHER...AS A STRONG UPSLOPE REGIME SETS UP OVER THE PLAINS AND
DEWPOINTS CLIMB FROM THE 40S AND LOWER 50S TO THE UPPER 50S AND
EVEN 60 DEGREE MARK BY EARLY NEXT WEEK. AT THIS TIME...IT LOOKS
LIKE SUNDAY AFTERNOON-EVE...WITH THE INITIAL SURGE...AND THEN
TUESDAY AFTERNOON AND EVE...WITH A SECONDARY PUSH OVER THE CENTRAL
PLAINS...WILL BE THE WETTEST DAYS. EVERY DAY WILL SEE THE
POTENTIAL FOR SOME LOCALLY HEAVY RAINFALL...BUT THOSE PERIODS ARE
PROBABLY THE HIGHEST THREAT FOR THE BURN SCARS AND POTENTIAL FLASH
FLOODING. COULD ALSO SEE SOME SVR STORMS ESPECIALLY ON TUESDAY OVR
THE PLAINS...AS NW FLOW ALOFT INCREASES A BIT AS THE RIDGE MOVE
WWD. TEMPS SHOULD SETTLE BACK INTO THE 70S AND 80S FROM SUNDAY
ONWARD THROUGH NEXT WEEK AS COOLER AND MOISTER AIR ARRIVES FROM
THE NORTH. ROSE
&&
.AVIATION...
ISSUED AT 1100 PM MDT WED JUL 23 2014
VFR CONDITIONS ARE EXPECTED TO CONTINUE OVER THE KALS...KCOS AND
KPUB TAF SITES TONIGHT AS A STRONG UPPER RIDGE REMAINS CENTERED
OVER SOUTHERN COLORADO
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
412 AM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONTAL BOUNDARY WILL CONTINUE MOVING OFFSHORE
TODAY. HIGH PRESSURE WILL BUILD ACROSS THE OHIO VALLEY TONIGHT AND
ON FRIDAY. THE HIGH PRESSURE SYSTEM WILL MOVE EAST OF THE REGION ON
SATURDAY AND BE FOLLOWED BY THE PASSAGE OF A WARM FRONT FROM THE
SOUTH BY SATURDAY NIGHT AND BE LOCATED TO OUR NORTH ON SUNDAY.
ANOTHER COLD FRONTAL BOUNDARY THEN WILL SWEEP FROM WEST TO EAST
ACROSS THE REGION ON MONDAY. A HIGH PRESSURE SYSTEM WILL BUILD IN
BEHIND THE COLD FRONT FOR THE MIDDLE HALF OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A CDFNT WAS WORKING ITS WAY ACRS THE REGION AND SHOULD BEE OFFSHORE
LATER THIS MRNG. HIGH PRES WILL SLOWLY BUILD IN BEHIND THE FRONT.
HOWEVER, SOME GUID STILL INDICATES THAT THERE IS ENOUGH INSTABILITY
AND WITH THE FRONT LOCATED JUST TO OUR S, THERE COULD BE SOME
SHOWERS AND SCT TSTMS, MAINLY OVER SRN AREAS FROM LATER THIS MRNG
INTO ERLY EVE. BOTH THE NAM/WRF AND GFS INDICATE AT LEAST SOME
POTENTIAL FOR PRECIP WHILE THE ECMWF IS DRIER. FOR NOW, WILL CARRY
SOME LOW POPS.
THE HRRR ALSO HAS SOME PRECIP MOVG IN FROM THE S AND W THIS AM.
THERE IS SOME LIGHT STUFF OVER PA AND MD, BUT THE HRRR APPEARS A BIT
OVERDONE.
OVERALL GUID TEMPS LOOK REASONABLE AND WERE GENLY FOLLOWED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
HIGH PRES WILL BUILD EWD AND INTO THE AREA TONIGHT. ANY PRECIP WILL
END EARLY AND THE SKY WILL CLEAR. OVERALL, A QUIET NIGHT IS IN
STORE.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
FRIDAY AND FRIDAY NIGHT: HIGH PRESSURE GLIDES EAST FROM THE OHIO
VALLEY INTO OUR REGION. VARIABLE WINDS, PLENTY OF SUNSHINE AND NOT
THAT HOT SINCE THIS AIRMASS WILL BE COMING FROM CANADA! LITTLE
SPREAD IN THE MODELS ON MOST IF NOT ALL WEATHER ELEMENTS. TRICKIEST
PART OF THIS PERIOD IS HOW MUCH RADIATIONAL COOLING CAN OCCUR IN
RURAL AREAS BEFORE THE FLOW TURNS MORE SOUTHERLY BY SATURDAY.
OPTED TO GO A TOUCH COOLER THAN MEX/MAV/MET IN A FEW SPOTS WITH
LOWS FRIDAY NIGHT.
SATURDAY AND SATURDAY NIGHT: A WARM FRONT APPROACHES THE REGION FROM
THE SOUTH AND WITH A DEPARTING HIGH PRESSURE THE FLOW TURNS
SOUTHERLY. MODELED MOMENTUM TRANSFER SUGGESTS SOME GUSTS CLOSE TO 20
MPH ARE POSSIBLE IN THE AFTERNOON, WENT HIGHER THAN A STANDARD
125% FOR WIND GUSTS. MID-LEVEL AND SURFACE TEMPERATURES LOOK TO
RESPOND IN KIND AFTER THE WARM FRONTAL PASSAGE, 925 MB TEMPS NEAR 20-22C
SHOULD YIELD SURFACE TEMPERATURES JUST UNDER 90 FOR PHL AND IN THE
80`S ELSEWHERE ACROSS THE REGION. HUMIDITY IS ON THE RISE BUT THIS
WILL BE LIKE MORE TYPICAL JULY HEAT WITH HEAT INDEX VALUES WELL
UNDER ADVISORY LEVELS. THE WARM FRONT MAY PROVIDE ENOUGH LIFT FOR
SOME SCATTERED SHOWERS AND THUNDERSTORMS FOCUSED ACROSS THE
NORTHERN PART OF THE REGION. THE 21Z SREF AND THE LAST TWO ECMWF
RUNS HAVE THESE PINED DOWN WELL. INCREASING CIN COUPLED WITH 700
MB TEMPS NEAR 10C COULD ALLOW FOR THE FORMATION OF A WEAK CAP
ACROSS THE SOUTHERN PART OF THE REGION, BEING FURTHER AWAY LOWER
CHANCE POPS WERE WARRANTED WHEN COMPARED TO LOCATIONS FURTHER
NORTH.
SUNDAY AND SUNDAY NIGHT: CONTINUED WEST-SOUTHWEST FLOW IN THE WARM
SECTOR. THE LAST FEW GFS RUNS HAVE BEEN MORE AGGRESSIVE WITH
CONVECTION BY THE AFTERNOON AND EVENING HOURS. A COMMON THEME THIS
SUMMER. THINK THE GFS IS TO AGGRESSIVE WITH THIS. HOWEVER, STORM
CHANCES SHOULD INCREASE AS THE MAIN LOW PRESSURE SYSTEM AND COLD
FRONT APPROACH THE REGION. GOOD AGREEMENT AMONG THE GFS ENSEMBLES,
ECMWF ENSEMBLE MEAN AND THE OPERATIONAL MODELS THAT THE HIGHEST
CHANCE WILL BE SUNDAY NIGHT. MAINTAINED LOW END LIKELY POPS ACROSS THE
NORTH AND HIGH END CHANCE ACROSS THE SOUTH. FOR QPF STAYED CLOSE TO
THE SREF AND ECMWF SIMILAR TO SATURDAY. THOUGH DID RAISE IT SLIGHTLY
TO ACCOUNT FOR THE MORE AGGRESSIVE GFS. TEMPERATURES MAY BE RAIN
COOLED SUNDAY BUT DID NOT GO IN THAT DIRECTION ATTM. FAIR SHOT AT 90
FOR PHL WITH SLIGHTLY WARMER MODELED MID-LEVEL TEMPERATURES THAN
SATURDAY.
MONDAY AND MONDAY NIGHT: THE COLD FRONT MOVES THROUGH LIKELY MONDAY
AFTERNOON. HOWEVER THIS SHOULD BE TO LITTLE TO LATE IN TERMS OF
ANOTHER ROUND OF SHOWERS AND STORMS. THE MAIN CAPE AXIS IS LIKELY TO
OFFSHORE AT THIS TIME AND LITTLE IS LEFT FOR A TRIGGER BESIDES THE
ACTUAL FRONTAL BOUNDARY. HOWEVER MAINTAINED LOW CHANCE POPS SINCE THE
FRONT WILL STILL BE IN THE REGION. CLEARED CONDITIONS OUT MONDAY
NIGHT WITH A RETURN TO WESTERLY FLOW. ANOTHER GUSTY DAY AS ONCE
MODELED MOMENTUM TRANSFER SHOWS POTENTIAL FOR SOME GUSTS NEAR 20
MPH.
TUESDAY AND WEDNESDAY: ANOTHER CANADIAN AIRMASS COMES DOWN INTO THE
REGION AS THE SAME GENERAL PATTERN FROM THE WINTERTIME CONTINUES
WITH FEW BREAKS. COOL NORTHWESTERLY FLOW WILL BE IN PLACE AS MOST
LOCATIONS STRUGGLE TO 80 FOR A HIGH. EVEN WITH THIS ABNORMALLY COOL
AIRMASS THERE IS GOOD AGREEMENT AMONG THE MEX, WPC AND MODELED TWO
METER TEMPERATURES. TRENDED SLIGHTLY COOLER THAN WPC GIVEN THE
LATEST 00Z ECMWF WHICH IS ON THE COOLEST END OF THE MODEL GUIDANCE.
LAPSE RATES MAY STEEPEN UP TUESDAY AFTERNOON FOR THE FORMATION OF
SOME CUMULUS AND SPOTTY SHOWERS/THUNDER ON THE BACKSIDE OF THE TROUGH
ACROSS THE NORTH WITH THE AID OF ELEVATION. OTHERWISE BOTH DAYS
LOOK MOSTLY SUNNY.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
GENLY VFR CONDS ARE EXPECTED TODAY. THERE COULD BE SOME LCL MVFR
THIS MRNG IN LOW CLOUDS OR FOG. ADDITIONALLY, THERE COULD BE SOME
SHRA OR ISOLD TSRA, MAINLY S LATER THIS MRNG THRU ERLY EVE WHICH CUD
BRIEFLY DECREASE CIGS/VSBYS. HOWEVER, ODDS ARE LOW ENOUGH TO NOT
MENTION IN THE INDIVIDUAL TAF SITES. WIND IS EXPECTED TO BE NW OR N
AROUND 10 KTS TODAY DECREASING TO LESS THAN 10 KTS TONIGHT.
OUTLOOK...
FRIDAY AND FRIDAY NIGHT: VFR
SATURDAY THROUGH MONDAY: BRIEF MVFR AND IFR RESTRICTIONS IN
SCATTERED THUNDERSTORMS. HIGHEST CHANCE FOR RESTRICTIONS IS ON
SUNDAY AFTERNOON AND EVENING FOR RDG, ABE, TTN, AND POINTS NORTH.
&&
.MARINE...
WITH HIGH PRES BUILDING INTO THE REGION, NO MARINE HEADLINES ARE
ANTICIPATED THRU THE NR AND SHORT TERM PDS.
OUTLOOK...
FRIDAY THROUGH SATURDAY NIGHT: SEAS AND WINDS EXPECTED TO STAY UNDER
SCA CRITERIA. A FEW WIND GUSTS AROUND 20 KNOTS POSSIBLE SATURDAY
AFTERNOON.
SUNDAY AND MONDAY: SEAS INCREASE TO FOUR FEET ON SUNDAY AND PERHAPS
FIVE FEET BY MONDAY MORNING BEFORE FALLING BELOW FIVE FEET MONDAY
NIGHT. A FEW WIND GUSTS AROUND 20 KNOTS POSSIBLE SUNDAY AND MONDAY
AFTERNOONS.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GAINES
NEAR TERM...NIERENBERG
SHORT TERM...NIERENBERG
LONG TERM...GAINES
AVIATION...GAINES/NIERENBERG
MARINE...GAINES/NIERENBERG
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
405 AM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONTAL BOUNDARY WILL CONTINUE MOVING OFFSHORE
TODAY. HIGH PRESSURE WILL BUILD ACROSS THE OHIO VALLEY TONIGHT AND
ON FRIDAY. THE HIGH PRESSURE SYSTEM WILL MOVE EAST OF THE REGION ON
SATURDAY AND BE FOLLOWED BY THE PASSAGE OF A WARM FRONT FROM THE
SOUTH BY SATURDAY NIGHT AND BE LOCATED TO OUR NORTH ON SUNDAY.
ANOTHER COLD FRONTAL BOUNDARY THEN WILL SWEEP FROM WEST TO EAST
ACROSS THE REGION ON MONDAY. A HIGH PRESSURE SYSTEM WILL BUILD IN
BEHIND THE COLD FRONT FOR THE MIDDLE HALF OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A CDFNT WAS WORKING ITS WAY ACRS THE REGION AND SHOULD BEE OFFSHORE
LATER THIS MRNG. HIGH PRES WILL SLOWLY BUILD IN BEHIND THE FRONT.
HOWEVER, SOME GUID STILL INDICATES THAT THERE IS ENOUGH INSTABILITY
AND WITH THE FRONT LOCATED JUST TO OUR S, THERE COULD BE SOME
SHOWERS AND SCT TSTMS, MAINLY OVER SRN AREAS FROM LATER THIS MRNG
INTO ERLY EVE. BOTH THE NAM/WRF AND GFS INDICATE AT LEAST SOME
POTENTIAL FOR PRECIP WHILE THE ECMWF IS DRIER. FOR NOW, WILL CARRY
SOME LOW POPS.
THE HRRR ALSO HAS SOME PRECIP MOVG IN FROM THE S AND W THIS AM.
THERE IS SOME LIGHT STUFF OVER PA AND MD, BUT THE HRRR APPEARS A BIT
OVERDONE.
OVERALL GUID TEMPS LOOK REASONABLE AND WERE GENLY FOLLOWED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
HIGH PRES WILL BUILD EWD AND INTO THE AREA TONIGHT. ANY PRECIP WILL
END EARLY AND THE SKY WILL CLEAR. OVERALL, A QUIET NIGHT IS IN
STORE.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
FRIDAY AND FRIDAY NIGHT: HIGH PRESSURE GLIDES EAST FROM THE OHIO
VALLEY INTO OUR REGION. VARIABLE WINDS, PLENTY OF SUNSHINE AND NOT
THAT HOT SINCE THIS AIRMASS WILL BE COMING FROM CANADA! LITTLE
SPREAD IN THE MODELS ON MOST IF NOT ALL WEATHER ELEMENTS. TRICKIEST
PART OF THIS PERIOD IS HOW MUCH RADIATIONAL COOLING CAN OCCUR IN
RURAL AREAS BEFORE THE FLOW TURNS MORE SOUTHERLY BY SATURDAY.
OPTED TO GO A TOUCH COOLER THAN MEX/MAV/MET IN A FEW SPOTS WITH
LOWS FRIDAY NIGHT.
SATURDAY AND SATURDAY NIGHT: A WARM FRONT APPROACHES THE REGION FROM
THE SOUTH AND WITH A DEPARTING HIGH PRESSURE THE FLOW TURNS
SOUTHERLY. MODELED MOMENTUM TRANSFER SUGGESTS SOME GUSTS CLOSE TO 20
MPH ARE POSSIBLE IN THE AFTERNOON, WENT HIGHER THAN A STANDARD
125% FOR WIND GUSTS. MID-LEVEL AND SURFACE TEMPERATURES LOOK TO
RESPOND IN KIND, 925 MB TEMPS NEAR 20-22C SHOULD YIELD SURFACE
TEMPERATURES JUST UNDER 90 FOR PHL AND IN THE 80`S ELSEWHERE ACROSS
THE REGION. HUMIDITY IS ON THE RISE BUT THIS WILL BE LIKE MORE
TYPICAL JULY HEAT WITH HEAT INDEX VALUES WELL UNDER ADVISORY LEVELS.
THE WARM FRONT MAY PROVIDE ENOUGH LIFT FOR SOME SCATTERED SHOWERS
AND THUNDERSTORMS FOCUSED ACROSS THE NORTHERN PART OF THE REGION.
THE 21Z SREF AND THE LAST TWO ECMWF RUNS HAVE THESE PINED DOWN WELL.
INCREASING CIN COUPLED WITH 700 MB TEMPS NEAR 10C COULD ALLOW FOR
THE FORMATION OF A WEAK CAP ACROSS THE SOUTHERN PART OF THE REGION,
BEING FURTHER AWAY LOWER CHANCE POPS WERE WARRANTED WHEN COMPARED TO
LOCATIONS FURTHER NORTH.
SUNDAY AND SUNDAY NIGHT: CONTINUED WEST-SOUTHWEST FLOW IN THE WARM
SECTOR. THE LAST FEW GFS RUNS HAVE BEEN MORE AGGRESSIVE WITH
CONVECTION BY THE AFTERNOON AND EVENING HOURS. A COMMON THEME THIS
SUMMER. THINK THE GFS IS TO AGGRESSIVE WITH THIS. HOWEVER, STORM
CHANCES SHOULD INCREASE AS THE MAIN LOW PRESSURE SYSTEM AND COLD
FRONT APPROACH THE REGION. GOOD AGREEMENT AMONG THE GFS ENSEMBLES,
ECMWF ENSEMBLE MEAN AND THE OPERATIONAL MODELS THAT THE HIGHEST
CHANCE WILL BE SUNDAY NIGHT. MAINTAINED LOW END LIKELY POPS ACROSS THE
NORTH AND HIGH END CHANCE ACROSS THE SOUTH. FOR QPF STAYED CLOSE TO
THE SREF AND ECMWF SIMILAR TO SATURDAY. THOUGH DID RAISE IT SLIGHTLY
TO ACCOUNT FOR THE MORE AGGRESSIVE GFS. TEMPERATURES MAY BE RAIN
COOLED SUNDAY BUT DID NOT GO IN THAT DIRECTION ATTM. FAIR SHOT AT 90
FOR PHL WITH SLIGHTLY WARMER MODELED MID-LEVEL TEMPERATURES THAN
SATURDAY.
MONDAY AND MONDAY NIGHT: THE COLD FRONT MOVES THROUGH LIKELY MONDAY
AFTERNOON. HOWEVER THIS SHOULD BE TO LITTLE TO LATE IN TERMS OF
ANOTHER ROUND OF SHOWERS AND STORMS. THE MAIN CAPE AXIS IS LIKELY TO
OFFSHORE AT THIS TIME AND LITTLE IS LEFT FOR A TRIGGER BESIDES THE
ACTUAL FRONTAL BOUNDARY. HOWEVER MAINTAINED LOW CHANCE POPS SINCE THE
FRONT WILL STILL BE IN THE REGION. CLEARED CONDITIONS OUT MONDAY
NIGHT WITH A RETURN TO WESTERLY FLOW. ANOTHER GUSTY DAY AS ONCE
MODELED MOMENTUM TRANSFER SHOWS POTENTIAL FOR SOME GUSTS NEAR 20
MPH.
TUESDAY AND WEDNESDAY: ANOTHER CANADIAN AIRMASS COMES DOWN INTO THE
REGION AS THE SAME GENERAL PATTERN FROM THE WINTERTIME CONTINUES
WITH FEW BREAKS. COOL NORTHWESTERLY FLOW WILL BE IN PLACE AS MOST
LOCATIONS STRUGGLE TO 80 FOR A HIGH. EVEN WITH THIS ABNORMALLY COOL
AIRMASS THERE IS GOOD AGREEMENT AMONG THE MEX, WPC AND MODELED TWO
METER TEMPERATURES. TRENDED SLIGHTLY COOLER THAN WPC GIVEN THE
LATEST 00Z ECMWF WHICH IS ON THE COOLEST END OF THE MODEL GUIDANCE.
LAPSE RATES MAY STEEPEN UP TUESDAY AFTERNOON FOR THE FORMATION OF
SOME CUMULUS AND SPOTTY SHOWERS/THUNDER ON THE BACKSIDE OF THE TROUGH
ACROSS THE NORTH WITH THE AID OF ELEVATION. OTHERWISE BOTH DAYS
LOOK MOSTLY SUNNY.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
GENLY VFR CONDS ARE EXPECTED TODAY. THERE COULD BE SOME LCL MVFR
THIS MRNG IN LOW CLOUDS OR FOG. ADDITIONALLY, THERE COULD BE SOME
SHRA OR ISOLD TSRA, MAINLY S LATER THIS MRNG THRU ERLY EVE WHICH CUD
BRIEFLY DECREASE CIGS/VSBYS. HOWEVER, ODDS ARE LOW ENOUGH TO NOT
MENTION IN THE INDIVIDUAL TAF SITES. WIND IS EXPECTED TO BE NW OR N
AROUND 10 KTS TODAY DECREASING TO LESS THAN 10 KTS TONIGHT.
OUTLOOK...
FRIDAY AND FRIDAY NIGHT: VFR
SATURDAY THROUGH MONDAY: BRIEF MVFR AND IFR RESTRICTIONS IN
SCATTERED THUNDERSTORMS. HIGHEST CHANCE FOR RESTRICTIONS IS ON
SUNDAY AFTERNOON AND EVENING FOR RDG, ABE, TTN, AND POINTS NORTH.
&&
.MARINE...
WITH HIGH PRES BUILDING INTO THE REGION, NO MARINE HEADLINES ARE
ANTICIPATED THRU THE NR AND SHORT TERM PDS.
OUTLOOK...
FRIDAY THROUGH SATURDAY NIGHT: SEAS AND WINDS EXPECTED TO STAY UNDER
SCA CRITERIA. A FEW WIND GUSTS AROUND 20 KNOTS POSSIBLE SATURDAY
AFTERNOON.
SUNDAY AND MONDAY: SEAS INCREASE TO FOUR FEET ON SUNDAY AND PERHAPS
FIVE FEET BY MONDAY MORNING BEFORE FALLING BELOW FIVE FEET MONDAY
NIGHT. A FEW WIND GUSTS AROUND 20 KNOTS POSSIBLE SUNDAY AND MONDAY
AFTERNOONS.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GAINES
NEAR TERM...NIERENBERG
SHORT TERM...NIERENBERG
LONG TERM...GAINES
AVIATION...GAINES/NIERENBERG
MARINE...GAINES/NIERENBERG
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
151 PM EDT THU JUL 24 2014
.PREV DISCUSSION... /ISSUED 1132 AM EDT THU JUL 24 2014/
UPDATE...
HAVE GONE THROUGH AND REDUCED POPS THIS MORNING BUT HAVE PRETTY
MUCH LEFT AFTERNOON TRENDS ALONE WITH THE APPROACH OF THE COLD
FRONT EXPECTED TO TRIGGER SHOWERS AND THUNDERSTORMS. HRRR HAS BEEN
PRETTY STEADFAST IN DEVELOPING CONVECTION ACROSS NORTH GEORGIA
AROUND 18Z THOUGH SOME OTHER HIRES MODELS DID START BACKING OFF ON
CONVECTION WITH OVERNIGHT RUNS. TEMPERATURES IN PRETTY GOOD SHAPE
BUT DEWPOINTS ARE RUNNING HIGHER THAN FORECAST SO HAVE MADE SOME
TWEAKS THERE. ALL IN ALL...NOT ENOUGH CHANGE TO WARRANT AN UPDATE
TO ZONE PRODUCTS.
TDP
PREV DISCUSSION... /ISSUED 732 AM EDT THU JUL 24 2014/
SHORT TERM /TODAY THROUGH FRIDAY/...
/ISSUED AT 456 AM EDT THU JUL 24 2014/
A COLD FRONT CURRENTLY ACROSS NORTH TN IS PROGGD BY MODELS TO SAG
SOUTHWARD TODAY. ALTHOUGH THE NAM IS SLIGHTLY SLOWER THAN THE GFS...
A BLEND IN TIMING WOULD PUSH THE FRONT INTO NORTH GA BY LATE THIS
MORNING... THEN ACROSS THE ATLANTA METRO AROUND LATE AFTERNOON OR
EARLY EVENING. THE NAM STALLS THE FRONT NEAR OR JUST NORTH OF
ATLANTA THIS EVENING... BUT EXPECT THE DEVELOPING MID TO UPPER NW
FLOW ALOFT TO BE SUFFICIENT TO PUSH THE FRONT SOUTH OF ATLANTA
TONIGHT AS THE GFS INDICATES. EITHER WAY...THE GREATER CHANCES FOR
SHOWERS AND THUNDERSTORMS WILL BE DURING DAYTIME HEATING TODAY AS
WEAK DISTURBANCES TRAVERSE THROUGH THE UPPER TROUGH AND HELP SPARK
CONVECTION ALONG AND AHEAD OF THE SLOW MOVING FRONT. WITH SOME
UNCERTAINTY OF THE FRONTS LOCATION TONIGHT... WILL SHOW A SLIGHT
CHANCE OF SHOWERS AND THUNDERSTORMS FOR ATLANTA AND AREAS SOUTHWARD
THROUGH MIDNIGHT... THEN SHIFT THIS POTENTIAL MAINLY SOUTH OF
ATLANTA AFTER MIDNIGHT. EXPECT A SLIGHTLY DRIER/COOLER AIR MASS TO
FILTER INTO NORTH GA TONIGHT AND POSSIBLY HANG AROUND ON FRIDAY...
BUT MODELS ARE HINTING AT THE FRONT DRIFTING BACK INTO NORTH GA
FRIDAY AFTERNOON. THIS WILL WARRANT HOLDING ONTO AT LEAST A SLIGHT
CHANCE OF SHOWERS AND THUNDERSTORMS FOR AREAS FROM ATLANTA SOUTHWARD
ON FRIDAY.
ALTHOUGH CANNOT RULE OUT AN ISOLATED STRONG OR SEVERE STORM THIS
AFTERNOON WITH MODERATE CAPE VALUES IN THE 2000-2500 J/KG RANGE...
EXPECT THIS THREAT TO BE MINIMAL AS WIND SHEAR AND FRONTAL FORCING
WILL BE WEAK. SPC IS SHOWING ONLY A GENERAL THUNDER OUTLOOK FOR THE
AREA THROUGH FRIDAY... AND THIS LOOKS REASONABLE EACH DAY.
WIDESPREAD RAINFALL AMOUNTS SHOULD AVERAGE AROUND ONE HALF INCH OR
LESS... WITH SOME ISOLATED SLIGHTLY HIGHER AMOUNTS POSSIBLE.
THEREFORE... FLOOD PROBLEMS ARE NOT EXPECTED AT THIS TIME.
AS FOR TEMPS...CLOUDS AND PRECIP SHOULD HELP HOLD HIGHS DOWN IN THE
LOWER TO MID 80S ACROSS MAINLY NORTH GA TODAY WHILE CENTRAL GA HEATS
UP INTO THE UPPER 80S TO LOWER 90S. EXPECTING SLIGHTLY COOLER LOWS
MOSTLY IN THE 60S FOR MUCH OF NORTH GA TONIGHT BEHIND THE FRONT. THE
COOLER TEMPS ARE SHORT-LIVED AS HIGHS CLIMB BACK INTO THE UPPER 80S
TO LOWER 90S FOR MOST AREAS ON FRIDAY. A MAV AND MET BLEND WITH SOME
TWEAKS LOOKED REASONABLE THROUGH THE SHORT TERM.
39
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
/ISSUED AT 456 AM EDT THU JUL 24 2014/
MODELS CONTINUE TO SHOW A FEW UPPER LEVEL DISTURBANCES TO
TRAVERSE THE REGION OVER THE WEEKEND. SURFACE HIGH SHOULD KEEP
POPS TO A MINIMUM SATURDAY...AND WITH FRONT APPROACHING THE AREA
SUNDAY...HIGH WILL LOSE CONTROL OF THE AREA AND ALLOW FOR
INCREASING RAIN CHANCES. EXTENDED PERIODS ARE STILL LARGELY
DOMINATED BY THIS STRONG COLD FRONT /ANOMALOUS FOR LATE JULY/ AND
MODELS AGREE WITH PUSHING IT THROUGH NORTH AND CENTRAL GEORGIA BY
LATE MONDAY. DEEP LONGWAVE TROUGH REMAINS POSITIONED OVER THE AREA
THROUGH MUCH OF NEXT WEEK...KEEPING LOWER DEW POINTS AND COOLER
TEMPERATURES IN PLACE IN THE WAKE OF THE COLD FRONT. SOME MOISTURE
DOES LOOK TO CREEP BACK NORTHWARD AS BOUNDARY REMAINS OVER SOUTH
GEORGIA...AND HAVE GENERALLY INCLUDED SLIGHT CHANCE POPS IN THE FAR
SOUTHERN PORTIONS OF THE CWA THROUGH WEDNESDAY. BEGINNING
TUESDAY...SHOULD SEE BELOW AVERAGE TEMPERATURES WITH HIGHS IN THE
UPPER 70S NORTH AND LOW 80S ELSEWHERE...AND LOWS IN THE 60S.
STRONG TO SEVERE STORMS MAY ACCOMPANY THE FRONT AS IT PUSHES
THROUGH THE AREA MONDAY WITH MODELS CONTINUING TO ADVERTISE A
COMBINATION OF DECENT SHEAR AND INSTABILITY. WITH SOME UNCERTAINTY
IN THE FORECAST MODELS REGARDING THE TIMING OF THIS SYSTEM...THE
SEVERE POTENTIAL WILL NEED TO CONTINUE TO BE MONITORED.
31
&&
.AVIATION...
18Z UPDATE...
SHRA AND TSRA INCREASING W/ A LINE OF CONVECTION ACROSS THE METRO
ATLANTA AREA. HAVE KEPT TEMPO GROUP TO COVER. OTHERWISE JUST VCSH
THROUGH ABOUT 02Z NORTH AND 04Z SOUTH WITH A DECREASE IN CLOUD
COVER THEREAFTER. SOME HINTS AT IFR CIGS AT CSG BUT THINK THAT
COVERAGE WOULD BE SCT AT BEST BUT WILL REEVALUATE. MVFR FOG
EXPECTED AT MOST SITES FRIDAY MORNING. WINDS GENERALLY W TO NW
THROUGH THE PERIOD WITH LOW-END GUSTS THIS AFTERNOON...NEARLY CALM
OVERNIGHT NIGHT.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM ON TIMING OF DIMINISHING CONVECTION.
HIGH ON ALL OTHER ELEMENTS.
TDP
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 90 69 89 69 / 60 30 10 5
ATLANTA 87 70 88 72 / 60 30 10 5
BLAIRSVILLE 82 61 83 61 / 60 20 10 5
CARTERSVILLE 87 68 88 68 / 60 20 5 5
COLUMBUS 89 73 90 74 / 60 30 30 5
GAINESVILLE 86 69 87 69 / 60 30 10 5
MACON 90 71 92 72 / 50 30 30 10
ROME 86 68 88 67 / 60 20 5 0
PEACHTREE CITY 88 69 88 69 / 60 40 20 5
VIDALIA 92 73 92 74 / 30 30 30 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1132 AM EDT THU JUL 24 2014
.UPDATE...
HAVE GONE THROUGH AND REDUCED POPS THIS MORNING BUT HAVE PRETTY
MUCH LEFT AFTERNOON TRENDS ALONE WITH THE APPROACH OF THE COLD
FRONT EXPECTED TO TRIGGER SHOWERS AND THUNDERSTORMS. HRRR HAS BEEN
PRETTY STEADFAST IN DEVELOPING CONVECTION ACROSS NORTH GEORGIA
AROUND 18Z THOUGH SOME OTHER HIRES MODELS DID START BACKING OFF ON
CONVECTION WITH OVERNIGHT RUNS. TEMPERATURES IN PRETTY GOOD SHAPE
BUT DEWPOINTS ARE RUNNING HIGHER THAN FORECAST SO HAVE MADE SOME
TWEAKS THERE. ALL IN ALL...NOT ENOUGH CHANGE TO WARRANT AN UPDATE
TO ZONE PRODUCTS.
TDP
&&
.PREV DISCUSSION... /ISSUED 732 AM EDT THU JUL 24 2014/
SHORT TERM /TODAY THROUGH FRIDAY/...
/ISSUED AT 456 AM EDT THU JUL 24 2014/
A COLD FRONT CURRENTLY ACROSS NORTH TN IS PROGGD BY MODELS TO SAG
SOUTHWARD TODAY. ALTHOUGH THE NAM IS SLIGHTLY SLOWER THAN THE GFS...
A BLEND IN TIMING WOULD PUSH THE FRONT INTO NORTH GA BY LATE THIS
MORNING... THEN ACROSS THE ATLANTA METRO AROUND LATE AFTERNOON OR
EARLY EVENING. THE NAM STALLS THE FRONT NEAR OR JUST NORTH OF
ATLANTA THIS EVENING... BUT EXPECT THE DEVELOPING MID TO UPPER NW
FLOW ALOFT TO BE SUFFICIENT TO PUSH THE FRONT SOUTH OF ATLANTA
TONIGHT AS THE GFS INDICATES. EITHER WAY...THE GREATER CHANCES FOR
SHOWERS AND THUNDERSTORMS WILL BE DURING DAYTIME HEATING TODAY AS
WEAK DISTURBANCES TRAVERSE THROUGH THE UPPER TROUGH AND HELP SPARK
CONVECTION ALONG AND AHEAD OF THE SLOW MOVING FRONT. WITH SOME
UNCERTAINTY OF THE FRONTS LOCATION TONIGHT... WILL SHOW A SLIGHT
CHANCE OF SHOWERS AND THUNDERSTORMS FOR ATLANTA AND AREAS SOUTHWARD
THROUGH MIDNIGHT... THEN SHIFT THIS POTENTIAL MAINLY SOUTH OF
ATLANTA AFTER MIDNIGHT. EXPECT A SLIGHTLY DRIER/COOLER AIR MASS TO
FILTER INTO NORTH GA TONIGHT AND POSSIBLY HANG AROUND ON FRIDAY...
BUT MODELS ARE HINTING AT THE FRONT DRIFTING BACK INTO NORTH GA
FRIDAY AFTERNOON. THIS WILL WARRANT HOLDING ONTO AT LEAST A SLIGHT
CHANCE OF SHOWERS AND THUNDERSTORMS FOR AREAS FROM ATLANTA SOUTHWARD
ON FRIDAY.
ALTHOUGH CANNOT RULE OUT AN ISOLATED STRONG OR SEVERE STORM THIS
AFTERNOON WITH MODERATE CAPE VALUES IN THE 2000-2500 J/KG RANGE...
EXPECT THIS THREAT TO BE MINIMAL AS WIND SHEAR AND FRONTAL FORCING
WILL BE WEAK. SPC IS SHOWING ONLY A GENERAL THUNDER OUTLOOK FOR THE
AREA THROUGH FRIDAY... AND THIS LOOKS REASONABLE EACH DAY.
WIDESPREAD RAINFALL AMOUNTS SHOULD AVERAGE AROUND ONE HALF INCH OR
LESS... WITH SOME ISOLATED SLIGHTLY HIGHER AMOUNTS POSSIBLE.
THEREFORE... FLOOD PROBLEMS ARE NOT EXPECTED AT THIS TIME.
AS FOR TEMPS...CLOUDS AND PRECIP SHOULD HELP HOLD HIGHS DOWN IN THE
LOWER TO MID 80S ACROSS MAINLY NORTH GA TODAY WHILE CENTRAL GA HEATS
UP INTO THE UPPER 80S TO LOWER 90S. EXPECTING SLIGHTLY COOLER LOWS
MOSTLY IN THE 60S FOR MUCH OF NORTH GA TONIGHT BEHIND THE FRONT. THE
COOLER TEMPS ARE SHORT-LIVED AS HIGHS CLIMB BACK INTO THE UPPER 80S
TO LOWER 90S FOR MOST AREAS ON FRIDAY. A MAV AND MET BLEND WITH SOME
TWEAKS LOOKED REASONABLE THROUGH THE SHORT TERM.
39
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
/ISSUED AT 456 AM EDT THU JUL 24 2014/
MODELS CONTINUE TO SHOW A FEW UPPER LEVEL DISTURBANCES TO
TRAVERSE THE REGION OVER THE WEEKEND. SURFACE HIGH SHOULD KEEP
POPS TO A MINIMUM SATURDAY...AND WITH FRONT APPROACHING THE AREA
SUNDAY...HIGH WILL LOSE CONTROL OF THE AREA AND ALLOW FOR
INCREASING RAIN CHANCES. EXTENDED PERIODS ARE STILL LARGELY
DOMINATED BY THIS STRONG COLD FRONT /ANOMALOUS FOR LATE JULY/ AND
MODELS AGREE WITH PUSHING IT THROUGH NORTH AND CENTRAL GEORGIA BY
LATE MONDAY. DEEP LONGWAVE TROUGH REMAINS POSITIONED OVER THE AREA
THROUGH MUCH OF NEXT WEEK...KEEPING LOWER DEW POINTS AND COOLER
TEMPERATURES IN PLACE IN THE WAKE OF THE COLD FRONT. SOME MOISTURE
DOES LOOK TO CREEP BACK NORTHWARD AS BOUNDARY REMAINS OVER SOUTH
GEORGIA...AND HAVE GENERALLY INCLUDED SLIGHT CHANCE POPS IN THE FAR
SOUTHERN PORTIONS OF THE CWA THROUGH WEDNESDAY. BEGINNING
TUESDAY...SHOULD SEE BELOW AVERAGE TEMPERATURES WITH HIGHS IN THE
UPPER 70S NORTH AND LOW 80S ELSEWHERE...AND LOWS IN THE 60S.
STRONG TO SEVERE STORMS MAY ACCOMPANY THE FRONT AS IT PUSHES
THROUGH THE AREA MONDAY WITH MODELS CONTINUING TO ADVERTISE A
COMBINATION OF DECENT SHEAR AND INSTABILITY. WITH SOME UNCERTAINTY
IN THE FORECAST MODELS REGARDING THE TIMING OF THIS SYSTEM...THE
SEVERE POTENTIAL WILL NEED TO CONTINUE TO BE MONITORED.
31
AVIATION...
12Z UPDATE...
AREA OBS AND SATELLITE SHOW FEW-SCT MID LEVEL CLOUDS SPREADING IN
FROM THE NORTH AHEAD OF A COLD FRONT SAGGING INTO FAR NORTH GA THIS
MORNING. EXPECT VFR CONDITIONS TO PREVAIL UNTIL MID MORNING WHEN
DAYTIME HEATING AND THE APPROACHING COLD FRONT COMBINE TO INCREASE
MID LEVEL CLOUDINESS OVER THE ATLANTA TAF SITES. AHEAD OF THE
FRONT... EXPECT NUMEROUS SHOWERS WITH SCATTERED THUNDERSTORMS TO
DEVELOP... WARRANTING VCSH BY 17Z AND TEMPO -TSRA FROM 18-22Z. THE
FRONT SHOULD PUSH SOUTH OF ATL BY 23-24Z WITH ASSOCIATED MID LEVEL
CIGS SCATTERING. LIGHT SW WINDS WILL INCREASE TO AROUND 8-10KTS WITH
A FEW GUSTS AFTER 14Z TODAY. EXPECT NW WINDS AROUND 5KTS OR LESS AND
VFR CONDITIONS TONIGHT...WITH SCT MID CLOUDS BY 15Z FRI.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM CONFIDENCE ON ALL ELEMENTS.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 90 69 89 69 / 60 30 20 10
ATLANTA 87 70 88 72 / 60 30 20 5
BLAIRSVILLE 82 61 83 61 / 60 20 10 5
CARTERSVILLE 87 68 88 68 / 60 20 10 5
COLUMBUS 89 73 90 74 / 60 30 30 10
GAINESVILLE 86 69 87 69 / 60 30 10 5
MACON 90 71 92 72 / 50 30 30 10
ROME 86 68 88 67 / 60 20 10 5
PEACHTREE CITY 88 69 88 69 / 60 40 20 10
VIDALIA 92 73 92 74 / 30 30 40 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...
AVIATION...
AREA FORECAST DISCUSSION
NWS GOODLAND KS
852 PM MDT FRI JUL 25 2014
.UPDATE...
ISSUED AT 846 PM MDT FRI JUL 25 2014
RADAR TRENDS OVER THE LAST HOUR HAVE SHOWN AN INCREASE IN
INTENSITY OF THE LINE OF STORMS MOVING EASTWARD. LOOKING AT RUC
SOUNDINGS FOR TRIBUNE THE BEST ELEVATED INSTABILITY IS ABOVE
700MB...WITH A BULLS EYE OF NEAR 1500J/KG OF CAPE JUST WEST OF THE
KS/CO LINE IN EASTERN CHEYENNE COUNTY. THIS INSTABILITY DRIFTS
SOUTH-SOUTHEAST OVER THE NEXT COUPLE OF HOURS BEFORE DISSIPATING.
MEANWHILE THE ELEVATED CAPE WILL LINGER UNTIL AROUND MIDNIGHT THEN
END AS THE ENVIRONMENT STABILIZES.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY)
ISSUED AT 112 PM MDT FRI JUL 25 2014
EARLY AFTERNOON WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW BROAD
RIDGE STILL IN PLACE FROM THE DESERT SW ACROSS THE SOUTHERN
PLAINS...WITH A PLUME OF MID-UPPER LEVEL MOISTURE AND WEAK VORTICITY
ROTATING AROUND THE NORTHERN PERIPHERY OF THIS RIDGE ACROSS THE
CENTRAL ROCKIES INTO THE HIGH PLAINS. A CLOSED LOW IS MOVING ACROSS
SOUTHERN CANADA WITH SOME WEAK REFLECTION OF THIS EXTENDING FURTHER
SOUTH INTO THE NORTHERN PLAINS. AT THE SURFACE A WEAK COLD FRONT HAS
STALLED OVER THE SOUTHERN PART OF OUR CWA...WITH FAVORABLE JULY
SOLAR ANGLE SUPPORTING GOOD RADIATIONAL WARMING THIS AFTERNOON AS
HIGHS HAVE STILL REACHED THE MID TO UPPER 90S OVER MUCH OF THE CWA
(A LITTLE COOLER TOWARDS THE NW).
STALLED FRONT IN THE SOUTH COMBINED WITH ELEVATED TERRAIN IN
COLORADO SHOULD HELP INITIATE THUNDERSTORMS (WHICH HAVE ALREADY
DEVELOPED ALONG FRONT RANGE). HIGH LCL/LFC OVER OUR CWA SHOULD KEEP
THUNDERSTORM ACTIVITY ELEVATED AND WITH INCREASING INSTABILITY AND
DCAPE WOULD SUPPORT POTENTIAL FOR DOWNBURSTS. IF UPDRAFTS ARE STRONG
ENOUGH...MAYBE LARGE HAIL WOULD BE POSSIBLE THIS
AFTERNOON/EVENING...HOWEVER WITH VERY WARM LOW-MID LEVELS ABOVE
SHALLOW FRONTAL INVERSION CONDITIONS ARE MORE IN LINE WITH A WIND
THREAT. GUIDANCE CONTINUES TO SHOW BETTER COVERAGE OVER
CWA...HOWEVER DESPITE GOOD SURFACE-BL MOISTURE ALONG FRONTAL ZONE
AIR MASS ITSELF IS FAIRLY DRY AND COVERAGE IS A QUESTION. BEST
FORCING WOULD ACTUALLY BE LATER IN THE EVENING AS SHORTWAVE (ALONG
WITH POSSIBLE OUTFLOW FROM POSSIBLE MCS IN THE NORTH) MOVES INTO THE
CWA. AT THIS POINT I WAS COMFORTABLE KEEPING COVERAGE ISOLATED AND
DELAYED EXIT UNTIL AFTER 06Z. WILL NEED TO MONITOR TRENDS AS WESTERN
LOCATIONS COULD SEE SLIGHTLY BETTER COVERAGE BEFORE SUNSET.
DEEPENING ON EVOLUTION OF OUTFLOW (AS INDICATED BY NAM) OR WEAK
FRONTAL PASSAGE SATURDAY TEMPS COULD BE TRICKY ONCE AGAIN AS HEIGHTS
AND PATTERN ALOFT WOULD GENERALLY SUPPORT GOOD DAYTIME HEATING AND A
RECOVERY OF THE AIR MASS IN PLACE. I KEPT TEMPS SIMILAR TO TODAY
WITH ABOVE NORMAL VALUES IN THE 90S (AROUND 100F IN THE EAST). HIGH
BASED THUNDERSTORMS MAY DEVELOP AGAIN SATURDAY AFTERNOON ALONG
FRONTAL ZONE IN THE SOUTH...HOWEVER CONFIDENCE IS LOW ON EARLIER
INITIATION OVER OUR CWA...WITH FLOW MORE SUPPORTIVE OF UPSTREAM
DEVELOPMENT IN COLORADO.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 220 PM MDT FRI JUL 25 2014
UPPER FLOW TRANSITIONS FROM ZONAL TO NORTHWESTERLY IN THE SUN-MON
TIME FRAME...WHICH THEN CONTINUES THROUGH THE REST OF THE WEEK.
AT THE SURFACE...A REINFORCING SHOT OF COOLER AIR DROPS DOWN SATURDAY
NIGHT WHICH PUSHES THE SURFACE FRONT WELL SOUTH OF THE FORECAST
AREA. AS A RESULT...MUCH OF THE PRECIPITATION POTENTIAL EARLY ON
WILL BE SOUTH AND WEST OF THE CWA. THE BEST WINDOW FOR THUNDERSTORMS
IN THE EXTENDED PERIOD WILL BE TUE NIGHT-WED NIGHT WHEN THE EC/GFS
BOTH GENERATE AN EXTENSIVE AREA OF PRECIPITATION WHICH MOVES
SOUTHEAST ACROSS THE REGION AS A SHORT WAVE TROUGH DROPS THROUGH
THE FLOW.
THE PRESENCE OF A CANADIAN AIR MASS WHICH DOMINATES THE ENTIRE WEEK
WILL PROVIDE RELIEF FROM THE RECENT STRETCH OF HOT WEATHER. 850 MB
TEMPERATURES ARE FORECAST TO REMAIN IN THE 22-25C RANGE THROUGH
NEXT WEEKEND...WHICH TRANSLATES TO LOW-MID 80S FOR HIGHS. THE
COOLEST DAY WILL BE WEDNESDAY GIVEN THE LIKELY PRESENCE OF CLOUDS
AND SCATTERED SHOWERS AND THUNDERSTORMS. DEPENDING ON CLOUD COVER
THERE IS POTENTIAL FOR SOME AREAS TO REMAIN IN THE UPPER 70S WED.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 525 PM MDT FRI JUL 25 2014
VFR CONDITIONS FORECAST FOR THE 0Z TAFS. WINDS WILL BECOME LIGHT
AND VARIABLE TONIGHT THEN STRENGTHEN FROM THE NORTH SATURDAY
AFTERNOON.
CURRENT RADAR SHOWS A LINE OF STORMS OVER EASTERN COLORADO SLOWLY
MOVING WEST. NEAR TERM MODELS DISAGREE HOW FAR EAST THE STORMS
WILL MAKE IT EARLY THIS EVENING. SOUNDINGS LOOK FAIRLY STABLE FOR
ELEVATED CONVECTION THIS EVENING...SO AM WONDERING HOW FAR EAST
THE CURRENT LINE WILL MOVE...SPECIFICALLY FOR KGLD. FOR NOW WILL
KEEP T-STORM MENTION OUT OF THE FORECAST FOR KGLD. HOWEVER IF
STORMS DO MOVE NEAR THE SITE WILL MOST LIKELY BE DURING THE 3-4Z
TIME FRAME.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...DLF
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
559 PM MDT FRI JUL 25 2014
.UPDATE...
ISSUED AT 553 PM MDT FRI JUL 25 2014
UPDATED FORECAST TO INCLUDE HIGHER RAINFALL CHANCES FOR THE
WESTERN 1/3 OF THE AREA FOR THE EARLY EVENING. THOUGHT ABOUT GOING
HIGHER THAN 50 PERCENT DUE TO HOW SOLID THE LINE LOOKS BUT PAST
SIMILAR SCENARIOS HAVE RESULTED IN THE LINE WEAKENING AS IT MOVES
INTO EAST CENTRAL COLORADO. DESPITE SOME OF THE NEAR TERM MODELS
SUGGESTING THE LINE WILL LAST PAST SUNSET...AM DOUBTFUL BASED ON
HOW STABLE SOUNDINGS LOOK AFTER SUNSET SO WILL NO GO HIGHER THAN
THE ISOLATED MENTION FOR THE REST OF THE EVENING.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY)
ISSUED AT 112 PM MDT FRI JUL 25 2014
EARLY AFTERNOON WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW BROAD
RIDGE STILL IN PLACE FROM THE DESERT SW ACROSS THE SOUTHERN
PLAINS...WITH A PLUME OF MID-UPPER LEVEL MOISTURE AND WEAK VORTICITY
ROTATING AROUND THE NORTHERN PERIPHERY OF THIS RIDGE ACROSS THE
CENTRAL ROCKIES INTO THE HIGH PLAINS. A CLOSED LOW IS MOVING ACROSS
SOUTHERN CANADA WITH SOME WEAK REFLECTION OF THIS EXTENDING FURTHER
SOUTH INTO THE NORTHERN PLAINS. AT THE SURFACE A WEAK COLD FRONT HAS
STALLED OVER THE SOUTHERN PART OF OUR CWA...WITH FAVORABLE JULY
SOLAR ANGLE SUPPORTING GOOD RADIATIONAL WARMING THIS AFTERNOON AS
HIGHS HAVE STILL REACHED THE MID TO UPPER 90S OVER MUCH OF THE CWA
(A LITTLE COOLER TOWARDS THE NW).
STALLED FRONT IN THE SOUTH COMBINED WITH ELEVATED TERRAIN IN
COLORADO SHOULD HELP INITIATE THUNDERSTORMS (WHICH HAVE ALREADY
DEVELOPED ALONG FRONT RANGE). HIGH LCL/LFC OVER OUR CWA SHOULD KEEP
THUNDERSTORM ACTIVITY ELEVATED AND WITH INCREASING INSTABILITY AND
DCAPE WOULD SUPPORT POTENTIAL FOR DOWNBURSTS. IF UPDRAFTS ARE STRONG
ENOUGH...MAYBE LARGE HAIL WOULD BE POSSIBLE THIS
AFTERNOON/EVENING...HOWEVER WITH VERY WARM LOW-MID LEVELS ABOVE
SHALLOW FRONTAL INVERSION CONDITIONS ARE MORE IN LINE WITH A WIND
THREAT. GUIDANCE CONTINUES TO SHOW BETTER COVERAGE OVER
CWA...HOWEVER DESPITE GOOD SURFACE-BL MOISTURE ALONG FRONTAL ZONE
AIR MASS ITSELF IS FAIRLY DRY AND COVERAGE IS A QUESTION. BEST
FORCING WOULD ACTUALLY BE LATER IN THE EVENING AS SHORTWAVE (ALONG
WITH POSSIBLE OUTFLOW FROM POSSIBLE MCS IN THE NORTH) MOVES INTO THE
CWA. AT THIS POINT I WAS COMFORTABLE KEEPING COVERAGE ISOLATED AND
DELAYED EXIT UNTIL AFTER 06Z. WILL NEED TO MONITOR TRENDS AS WESTERN
LOCATIONS COULD SEE SLIGHTLY BETTER COVERAGE BEFORE SUNSET.
DEEPENING ON EVOLUTION OF OUTFLOW (AS INDICATED BY NAM) OR WEAK
FRONTAL PASSAGE SATURDAY TEMPS COULD BE TRICKY ONCE AGAIN AS HEIGHTS
AND PATTERN ALOFT WOULD GENERALLY SUPPORT GOOD DAYTIME HEATING AND A
RECOVERY OF THE AIR MASS IN PLACE. I KEPT TEMPS SIMILAR TO TODAY
WITH ABOVE NORMAL VALUES IN THE 90S (AROUND 100F IN THE EAST). HIGH
BASED THUNDERSTORMS MAY DEVELOP AGAIN SATURDAY AFTERNOON ALONG
FRONTAL ZONE IN THE SOUTH...HOWEVER CONFIDENCE IS LOW ON EARLIER
INITIATION OVER OUR CWA...WITH FLOW MORE SUPPORTIVE OF UPSTREAM
DEVELOPMENT IN COLORADO.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 220 PM MDT FRI JUL 25 2014
UPPER FLOW TRANSITIONS FROM ZONAL TO NORTHWESTERLY IN THE SUN-MON
TIME FRAME...WHICH THEN CONTINUES THROUGH THE REST OF THE WEEK.
AT THE SURFACE...A REINFORCING SHOT OF COOLER AIR DROPS DOWN SATURDAY
NIGHT WHICH PUSHES THE SURFACE FRONT WELL SOUTH OF THE FORECAST
AREA. AS A RESULT...MUCH OF THE PRECIPITATION POTENTIAL EARLY ON
WILL BE SOUTH AND WEST OF THE CWA. THE BEST WINDOW FOR THUNDERSTORMS
IN THE EXTENDED PERIOD WILL BE TUE NIGHT-WED NIGHT WHEN THE EC/GFS
BOTH GENERATE AN EXTENSIVE AREA OF PRECIPITATION WHICH MOVES
SOUTHEAST ACROSS THE REGION AS A SHORT WAVE TROUGH DROPS THROUGH
THE FLOW.
THE PRESENCE OF A CANADIAN AIR MASS WHICH DOMINATES THE ENTIRE WEEK
WILL PROVIDE RELIEF FROM THE RECENT STRETCH OF HOT WEATHER. 850 MB
TEMPERATURES ARE FORECAST TO REMAIN IN THE 22-25C RANGE THROUGH
NEXT WEEKEND...WHICH TRANSLATES TO LOW-MID 80S FOR HIGHS. THE
COOLEST DAY WILL BE WEDNESDAY GIVEN THE LIKELY PRESENCE OF CLOUDS
AND SCATTERED SHOWERS AND THUNDERSTORMS. DEPENDING ON CLOUD COVER
THERE IS POTENTIAL FOR SOME AREAS TO REMAIN IN THE UPPER 70S WED.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 525 PM MDT FRI JUL 25 2014
VFR CONDITIONS FORECAST FOR THE 0Z TAFS. WINDS WILL BECOME LIGHT
AND VARIABLE TONIGHT THEN STRENGTHEN FROM THE NORTH SATURDAY
AFTERNOON.
CURRENT RADAR SHOWS A LINE OF STORMS OVER EASTERN COLORADO SLOWLY
MOVING WEST. NEAR TERM MODELS DISAGREE HOW FAR EAST THE STORMS
WILL MAKE IT EARLY THIS EVENING. SOUNDINGS LOOK FAIRLY STABLE FOR
ELEVATED CONVECTION THIS EVENING...SO AM WONDERING HOW FAR EAST
THE CURRENT LINE WILL MOVE...SPECIFICALLY FOR KGLD. FOR NOW WILL
KEEP T-STORM MENTION OUT OF THE FORECAST FOR KGLD. HOWEVER IF
STORMS DO MOVE NEAR THE SITE WILL MOST LIKELY BE DURING THE 3-4Z
TIME FRAME.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...DLF
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
532 PM MDT FRI JUL 25 2014
.SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY)
ISSUED AT 112 PM MDT FRI JUL 25 2014
EARLY AFTERNOON WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW BROAD
RIDGE STILL IN PLACE FROM THE DESERT SW ACROSS THE SOUTHERN
PLAINS...WITH A PLUME OF MID-UPPER LEVEL MOISTURE AND WEAK VORTICITY
ROTATING AROUND THE NORTHERN PERIPHERY OF THIS RIDGE ACROSS THE
CENTRAL ROCKIES INTO THE HIGH PLAINS. A CLOSED LOW IS MOVING ACROSS
SOUTHERN CANADA WITH SOME WEAK REFLECTION OF THIS EXTENDING FURTHER
SOUTH INTO THE NORTHERN PLAINS. AT THE SURFACE A WEAK COLD FRONT HAS
STALLED OVER THE SOUTHERN PART OF OUR CWA...WITH FAVORABLE JULY
SOLAR ANGLE SUPPORTING GOOD RADIATIONAL WARMING THIS AFTERNOON AS
HIGHS HAVE STILL REACHED THE MID TO UPPER 90S OVER MUCH OF THE CWA
(A LITTLE COOLER TOWARDS THE NW).
STALLED FRONT IN THE SOUTH COMBINED WITH ELEVATED TERRAIN IN
COLORADO SHOULD HELP INITIATE THUNDERSTORMS (WHICH HAVE ALREADY
DEVELOPED ALONG FRONT RANGE). HIGH LCL/LFC OVER OUR CWA SHOULD KEEP
THUNDERSTORM ACTIVITY ELEVATED AND WITH INCREASING INSTABILITY AND
DCAPE WOULD SUPPORT POTENTIAL FOR DOWNBURSTS. IF UPDRAFTS ARE STRONG
ENOUGH...MAYBE LARGE HAIL WOULD BE POSSIBLE THIS
AFTERNOON/EVENING...HOWEVER WITH VERY WARM LOW-MID LEVELS ABOVE
SHALLOW FRONTAL INVERSION CONDITIONS ARE MORE IN LINE WITH A WIND
THREAT. GUIDANCE CONTINUES TO SHOW BETTER COVERAGE OVER
CWA...HOWEVER DESPITE GOOD SURFACE-BL MOISTURE ALONG FRONTAL ZONE
AIR MASS ITSELF IS FAIRLY DRY AND COVERAGE IS A QUESTION. BEST
FORCING WOULD ACTUALLY BE LATER IN THE EVENING AS SHORTWAVE (ALONG
WITH POSSIBLE OUTFLOW FROM POSSIBLE MCS IN THE NORTH) MOVES INTO THE
CWA. AT THIS POINT I WAS COMFORTABLE KEEPING COVERAGE ISOLATED AND
DELAYED EXIT UNTIL AFTER 06Z. WILL NEED TO MONITOR TRENDS AS WESTERN
LOCATIONS COULD SEE SLIGHTLY BETTER COVERAGE BEFORE SUNSET.
DEEPENING ON EVOLUTION OF OUTFLOW (AS INDICATED BY NAM) OR WEAK
FRONTAL PASSAGE SATURDAY TEMPS COULD BE TRICKY ONCE AGAIN AS HEIGHTS
AND PATTERN ALOFT WOULD GENERALLY SUPPORT GOOD DAYTIME HEATING AND A
RECOVERY OF THE AIR MASS IN PLACE. I KEPT TEMPS SIMILAR TO TODAY
WITH ABOVE NORMAL VALUES IN THE 90S (AROUND 100F IN THE EAST). HIGH
BASED THUNDERSTORMS MAY DEVELOP AGAIN SATURDAY AFTERNOON ALONG
FRONTAL ZONE IN THE SOUTH...HOWEVER CONFIDENCE IS LOW ON EARLIER
INITIATION OVER OUR CWA...WITH FLOW MORE SUPPORTIVE OF UPSTREAM
DEVELOPMENT IN COLORADO.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 220 PM MDT FRI JUL 25 2014
UPPER FLOW TRANSITIONS FROM ZONAL TO NORTHWESTERLY IN THE SUN-MON
TIME FRAME...WHICH THEN CONTINUES THROUGH THE REST OF THE WEEK.
AT THE SURFACE...A REINFORCING SHOT OF COOLER AIR DROPS DOWN SATURDAY
NIGHT WHICH PUSHES THE SURFACE FRONT WELL SOUTH OF THE FORECAST
AREA. AS A RESULT...MUCH OF THE PRECIPITATION POTENTIAL EARLY ON
WILL BE SOUTH AND WEST OF THE CWA. THE BEST WINDOW FOR THUNDERSTORMS
IN THE EXTENDED PERIOD WILL BE TUE NIGHT-WED NIGHT WHEN THE EC/GFS
BOTH GENERATE AN EXTENSIVE AREA OF PRECIPITATION WHICH MOVES
SOUTHEAST ACROSS THE REGION AS A SHORT WAVE TROUGH DROPS THROUGH
THE FLOW.
THE PRESENCE OF A CANADIAN AIR MASS WHICH DOMINATES THE ENTIRE WEEK
WILL PROVIDE RELIEF FROM THE RECENT STRETCH OF HOT WEATHER. 850 MB
TEMPERATURES ARE FORECAST TO REMAIN IN THE 22-25C RANGE THROUGH
NEXT WEEKEND...WHICH TRANSLATES TO LOW-MID 80S FOR HIGHS. THE
COOLEST DAY WILL BE WEDNESDAY GIVEN THE LIKELY PRESENCE OF CLOUDS
AND SCATTERED SHOWERS AND THUNDERSTORMS. DEPENDING ON CLOUD COVER
THERE IS POTENTIAL FOR SOME AREAS TO REMAIN IN THE UPPER 70S WED.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 525 PM MDT FRI JUL 25 2014
VFR CONDITIONS FORECAST FOR THE 0Z TAFS. WINDS WILL BECOME LIGHT
AND VARIABLE TONIGHT THEN STRENGTHEN FROM THE NORTH SATURDAY
AFTERNOON.
CURRENT RADAR SHOWS A LINE OF STORMS OVER EASTERN COLORADO SLOWLY
MOVING WEST. NEAR TERM MODELS DISAGREE HOW FAR EAST THE STORMS
WILL MAKE IT EARLY THIS EVENING. SOUNDINGS LOOK FAIRLY STABLE FOR
ELEVATED CONVECTION THIS EVENING...SO AM WONDERING HOW FAR EAST
THE CURRENT LINE WILL MOVE...SPECIFICALLY FOR KGLD. FOR NOW WILL
KEEP T-STORM MENTION OUT OF THE FORECAST FOR KGLD. HOWEVER IF
STORMS DO MOVE NEAR THE SITE WILL MOST LIKELY BE DURING THE 3-4Z
TIME FRAME.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...DLF
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1200 PM MDT THU JUL 24 2014
.UPDATE...
ISSUED AT 924 AM MDT THU JUL 24 2014
CURRENT NEAR TERM FORECAST CONCERNS FOCUS ON HOW WARM THINGS WILL
GET THIS AFTERNOON COMBINED WITH MAGNITUDE OF DEWPOINT FALLS AS
DRYLINE DEVELOPS THIS AFTERNOON.
LATEST RAP AND HRRR AND TO A LESSER DEGREE THE NAM ARE SUPPORTING
A WELL MIXED VERY WARM PATTERN ACROSS THE CWA PUSHING HIGHS ABOVE
105 IN SEVERAL LOCATIONS. NOT TOTALLY SOLD ON THIS AS MODELS ARE
AGGRESSIVELY MIXING THINGS FASTER THAN CURRENT OBSERVATIONS. GOES
SOUNDER DATA DOES INDICATE AN AREA OF LOW PW`S NOSING INTO THE
WESTERN CWA AS OF 14Z...WHICH WOULD SUPPORT A LAYER OF DRIER AIR
OFF OF THE SURFACE WHICH COULD POTENTIALLY DILUTE SFC TDS THIS
AFTERNOON. HAVE LOWERED BOTH THE TD AND RAISED TEMPS A FEW DEGREES
BASED ON LATEST DATA AND WILL CLOSELY MONITOR TRENDS TO SEE IF
MUCH WARMER TEMPS ARE NEEDED.
GIVEN DRY AIR AND INCREASING SOUTHWESTERLY WINDS...FIRE WX MAY
BECOME A LARGE CONCERN THIS AFTERNOON ESPECIALLY NEAR RECENTLY
HARVESTED OR READY FOR HARVEST WHEAT FIELDS. CURRENTLY WIDESPREAD
CRITICAL FUELS ARE IN QUESTION THOUGH SO NOT SURE A RFW IS VALID
AT THIS POINT IN THE GREEN UP CYCLE. FOR THE TIME BEING...PLAN ON
HIGHLIGHTING POTENTIALLY CRITICAL LOCAL FIRE DANGER IN SPS FOR NOW
UNTIL FUEL INFORMATION BECOMES MORE APPARENT.
UPDATE ISSUED AT 630 AM MDT THU JUL 24 2014
SMALL AREA OF LOW STRATUS AND MINOR FOG HAS DEVELOPED TO THE EAST
OF SURFACE TROUGH STRETCHING FROM GARDEN CITY TO RUSSEL SPRINGS.
THIS IS NOT A PARTICULARLY WIDE AREA AND THINK MORNING SUN SHOULD
HELP MIX OUT FOG AND LOWER CLOUDS FAIRLY QUICKLY.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 324 AM MDT THU JUL 24 2014
FORECAST PROBLEMS WILL BE CHANCES OF PRECIPITATION AND HOW HOT DOES
IT GET. SATELLITE SHOWING AN AMPLIFIED PATTERN FROM THE EASTERN
PACIFIC INTO THE WESTERN ATLANTIC. STRONG RIDGE CENTERED TO OUR
SOUTHWEST IS STARTING TO BE PUSHED SOUTH BY A STRONG UPPER SYSTEM
THAT IS NOW MOVING INTO THE PACIFIC NORTHWEST. STALLED FRONTAL
BOUNDARY IS NEAR THE WESTERN END OF OUR AREA.
AT MID LEVELS...MODELS TENDED TO BE A LITTLE TOO FAR EAST...
ESPECIALLY WITH THE PACIFIC NORTHWEST SYSTEM. OVERALL THE ECMWF WAS
DOING A LITTLE BETTER THAN THE GFS AND UKMET. AT LOW LEVELS...THE
ECMWF AND SREF WERE DOING THE BEST. THE ECMWF WAS DOING A LITTLE
BETTER ON THE LOW LEVEL THERMAL FIELD.
TODAY/TONIGHT...SURFACE TROUGH AND SHORTWAVE TROUGH MOVE INTO THE
WESTERN PORTION OF THE FORECAST AREA LATER THIS AFTERNOON. THERE IS
A DEEP DRY LAYER SHOWN BY THE MODEL SOUNDINGS WITH 700 MB
TEMPERATURES GREATER THAN +15. WILL KEEP A SLIGHT CHANCE OF
PRECIPITATION BUT PULL THE SLIGHT CHANCE BACK FURTHER WEST TOWARD
THE LIFT. THIS ALSO MATCHES WITH GEFS PROBABILITIES. NEW GUIDANCE
SUPPORTED ONLY MAKING SLIGHT ADJUSTMENTS TO THE HIGH TEMPERATURES.
QUESTION THEN BECOMES HOW FAR EAST DOES IT GO DURING THE NIGHT.
INITIALLY MOST OF THE LIFT ALOFT GOES ACROSS THE NORTHWEST HALF
DURING THE EVENING. HOWEVER...THE SURFACE TROUGH AND REMAINDER OF THE
SHORTWAVE GOES ACROSS DURING THE NIGHT. SINCE LIFT DOES NOT LOOK THAT
STRONG RIGHT NOW AND THERE IS A DEEP DRY LAYER WILL CONTINUE WHAT THE
DAY SHIFT PUT IN WHICH IS THE SLIGHT CHANCE ACROSS THE NORTHWEST HALF
DURING THE EVENING. THIS ALSO MATCHES WITH THE PROBABILITY FORECAST
WHICH DOES KEEP MEASURABLE A LITTLE FURTHER WEST AS WELL.
FRIDAY/FRIDAY NIGHT...MODELS NOW APPEAR A LITTLE SLOWER WITH THE
COLD FRONT...BEING PUSHED BY NORTHERN SYSTEM. IN FACT MOST OF THEM
STALL THE FRONT OVER THE CENTRAL/SOUTHEAST PORTION BY LATE IN THE
AFTERNOON. THIS THEN LOOKS TO PULL BACK TO THE NORTH DURING THE
EVENING BEFORE COMING THROUGH IN THE LATER HALF OF THE NIGHT.
ALSO A WEAKER SHORTWAVE WILL MOVE ACROSS WHERE THE FRONT WILL BE IN
THE AFTERNOON. AFTER THAT A MUCH STRONGER SHORTWAVE MOVES IN FROM
THE WEST DURING THE NIGHT. COMPLICATE THAT WITH 700 MB TEMPERATURES
NEAR OR ABOVE PLUS 15 AND A DEEP DRY LAYER IN THE BOTTOM HALF OF
THE ATMOSPHERE. STORM MOTIONS WILL BE VERY SLOW AS WELL. SO COULD
POSSIBLY HAVE THUNDERSTORMS DEVELOP NEAR/JUST WEST OF THE BOUNDARY
AND/OR COME OFF THE HIGHER TERRAIN TO THE WEST DUE TO THE SHORTWAVE
AND SOME UPSLOPE FLOW. WILL PUT SOME SLIGHT CHANCE POPS WITH THE
FRONT IN THE AFTERNOON.
QUESTION ONCE AGAIN IS HOW FAR EAST DOES THE CONVECTION GO AND HOW
LONG IT GOES INTO THE NIGHT. MODEL QPF AND PROBABILITY FORECASTS
TEND TO FAVOR THE WESTERN PORTION OF THE AREA AND TO OUR NORTH. RIGHT
THE CURRENT FORECAST IN THE EVENING LOOKS REASONABLE AND ONLY MADE A
SLIGHT ADJUSTMENT. HOWEVER WITH THE BOUNDARY AND DECENT LIFT MOVING
THROUGH IN THE LATTER HALF OF THE NIGHT...WILL INSERT A SLIGHT CHANCE
IN THE SOUTHEAST HALF.
HIGH TEMPERATURES WILL BE INTERESTING DEPENDING ON THE SPEED AND
POSITION OF THE FRONT. SINCE MODELS ARE SLOWER WITH THE FRONT...
MODEL TEMPERATURES ARE WARMER THAN THEY WERE YESTERDAY...ESPECIALLY
IN THE SOUTHEAST PORTION OF THE AREA. SO ENDED UP RAISING MAXES...
ESPECIALLY IN THE SOUTHEAST HALF.
SATURDAY/SATURDAY NIGHT...AT THIS TIME IT LOOKS LIKE THE FRONT IS
THROUGH THE ENTIRE AREA...NOT BY MUCH...BY EARLY AFTERNOON. SO AIR
MASS WILL BE COOLER WITH SOME WEAK UPSLOPE OCCURRING. THIS FRONT
CONTINUES TO MOVE SOUTH AND EAST THROUGH THE NIGHT. WITH THE FRONT
THROUGH THE AREA BELIEVE INITIALLY THAT THE PRECIPITATION WILL BE
TIED TO IT WITH THE MAIN AREA SOUTH AND EAST OF THE FORECAST AREA.
IT WILL BE POSSIBLE THAT THE FAR WEST WILL SEE SOME STORMS WITH THE
NEXT SHORTWAVE TROUGH APPROACHING THE POST FRONTAL UPSLOPE AIR
MASS. SO REDUCED POPS TO JUST THAT AREA IN THE AFTERNOON.
SHORTWAVE TROUGH MOVING THROUGH DURING THE NIGHT. BUT MODELS
DISAGREE ON WHERE THE BEST LIFT AND HOW MUCH INSTABILITY WILL BE
PRESENT. OVERALL SETUP AND PROBABILITIES SUPPORT THE SOUTHWEST HALF
OF THE FORECAST AREA AT THIS TIME. SO LEFT THE CURRENT FORECAST
ALONE.
EVEN THOUGH MOST OF THE AREA IS BEHIND THE FRONT BY SHORTLY AFTER
18Z...MODELS DISAGREE ON HOW MUCH COOLER AIR TO BRING INTO THE
AREA. ONCE AGAIN THE FURTHER NORTH AND WEST YOU GO...THE LESS HOT IT
WILL BE. AGAIN THE SOUTHEAST WILL SEE THE HOTTEST TEMPERATURES.
MADE ONLY MINOR ADJUSTMENTS TO ONGOING FORECAST.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 150 AM MDT THU JUL 24 2014
FOR THE EXTENDED PERIOD...REGION WILL SEE PATTERN SHIFT AS MODELS
BEGIN TO STRENGTHEN H5/H7 RIDGES OVER THE WESTERN PORTIONS OF THE
COUNTRY...COUNTERACTED WITH A DEEPENING TROUGH/UPPER LOW SETTING UP
OVER THE GREAT LAKES/NORTHEAST REGIONS. UPPER FLOW AS A RESULT WILL
BE NORTHWEST OVER THE AREA FOR THE ENTIRE EXTENDED TIME FRAME. AT
THE SURFACE...A SERIES OF WEAK WAVES WILL MOVE OFF THE EASTERN
PORTION OF THE ROCKIES FOR SUNDAY INTO MONDAY NIGHT...FOLLOWED BY A
STRONGER LEE-SIDE TROUGH THAT SETS UP ON TUESDAY...SETTLING SOUTH OF
REGION EARLY WEDNESDAY AND THEN CONVERTING TO INVERTED TROUGH AND
MEANDER OF THE REGION THROUGH WEDNESDAY. THE RESULT OF THE SYNOPTIC
SETUP WILL BRING CHANCE FOR TRW/RW ALMOST EVERY DAY WITH BEST
CHANCES BEING TUESDAY INTO WEDNESDAY AND THIS IS WHERE HIGHEST POPS
(30-40) ARE HIGHLIGHTED...BEFORE THINGS WIND DOWN WEDNESDAY NIGHT
INTO THURSDAY. AS A RESULT OF THE BROAD NW UPPER FLOW AND EXPECTED
CLOUD COVER...TEMPERATURES WILL BE GENERALLY A FEW DEGREES BELOW
NORMAL WITH HIGHS IN THE 80S TO LOW 90S IN SPOTS. OVERNIGHT LOWS WILL
RANGE IN THE LOW/MID 60S AND WILL BE HAMPERED AT TIMES IF ANY
RESIDUAL CLOUDS REMAIN FROM CONVECTION DURING THE AFTERNOON/EVENING
HOURS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1158 AM MDT THU JUL 24 2014
VFR CONDITIONS EXPECTED FOR THE NEXT 24 HOURS WITH GUSTY SOUTHERLY
WINDS EXPECTED THROUGH SUNSET...WITH WINDS AT MCK INCREASING BY
20Z. COLD FRONT WILL SLIDE THROUGH AREA AFTER 13Z...BRINGING A
PERIOD OF GUSTY NORTHERLY WINDS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JRM
SHORT TERM...BULLER
LONG TERM...JN
AVIATION...JRM
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1231 PM CDT Thu Jul 24 2014
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 349 AM CDT THU JUL 24 2014
Water vapor imagery this morning showed the broad mid-level ridge
still anchored across the Rockies, resulting in northwesterly aloft
across the forecast area. A few weak embedded shortwaves were noted
along the northern edge of the ridge axis over South Dakota. While
these waves should progress southeastward along the ridge axis, most
models show any precipitation that develops from these waves to
remain north of the forecast area. It`s worth noting though that
recent early morning runs of the HRRR and RAP have started to show
precipitation from these shortwaves diving further south along the
Nebraska/Iowa border and skimming near far northeast Kansas by this
afternoon. However, due to the agreement of the synoptic models in
keeping precipitation north of the area and with the fairly poor
performance of these short-range models over the last few days, have
gone with a dry forecast for today but will continue to monitor
these shortwaves through the day.
Surface high pressure was situated over the region early this
morning, resulting in light winds, mostly clear skies, and cooler
conditions as temperatures dropped into the 60s. This surface high
gradually will shift eastward toward the Ohio River Valley, with
winds shifting to the southeast today and further to the south
overnight. These southeasterly winds today will keep temperatures
near or slightly below the seasonal normals as afternoon highs
should reach into the mid 80s east to low 90s west.
Water vapor imagery showed a mid-level trough and closed-off low
moving onshore in the Pacific Northwest, and models show this low
progressing eastward along the U.S./Canadian border over the next
few days. This advancing low will help to flatten the mid-level
ridge currently in place, resulting in the area of surface low
pressure currently over the northern Rockies being pushed southward
into the High Plains tonight. Model soundings show high clouds
building in over the region tonight, so this cloud cover combined
with southerly winds will result in better insolation and keep low
temperatures tonight a few degrees warmer in the upper 60s to mid
70s.
.LONG TERM...(Friday through Wednesday)
Issued at 349 AM CDT THU JUL 24 2014
Friday, the upper level ridge builds into northeast Kansas with the
edge of the westerlies over Missouri and Iowa. Thermal axis will
develop across the Central Plains ahead of a surface trough/front
that is expected to slowly move across Nebraska and into north
central Kansas by Friday evening. Dew point temperatures in the
middle 60s in north central Kansas and near 70 in northeast Kansas
will combine with afternoon temperatures from the upper 90s in far
eastern counties to around 105 toward central Kansas to produce
afternoon heat indices of 104 to 109 and will likely need a heat
advisory for the day on Friday.
The frontal boundary will slowly move south Saturday and Saturday
night settling in southern Kansas by Sunday morning as the upper
level ridge is suppressed westward as an upper level trough moves
across southern Canada and the Northern Plains. A unstable airmass
develops across northern Kansas Saturday with CAPE of 2500-5000 J/kg
and moderate shear. Soundings show inverted V cap eroding by late
afternoon and could see some isolated thunderstorms developing. If
they do develop then damaging wind gusts will be the main hazard.
Saturday will be a little cooler than Friday due to the presence of
mid and upper level clouds. However temperatures will range from
the lower 90s along the Nebraska border to around 101 near central
Kansas. Dew points in the upper 60s to around 70 will combine with
the temperatures to produce heat indices of 99 to 104.
Cooler temperatures and dry weather are expected on Sunday in the
wake of the front and this should continue into mid week with
northwest flow aloft and high pressure over much of the Central
Plains. The next chance of precipitation comes Tuesday night and
Wednesday with the western counties having the best chances. Both
the GFS and ECMWF indicate mid level waves moving through the
northwest flow.
&&
.AVIATION...(For the 18Z TAFs through 18Z Friday Afternoon)
Issued at 1223 PM CDT THU JUL 24 2014
VFR prevails for KTOP/KMHK/KFOE as southeasterly winds above 10
kts through the afternoon may only fall just below 10 kts
overnight as a deepening surface trough shifts eastward. Winds
veer to the south 08-10Z as winds increase between 10 and 13 kts
sustained. Higher speeds with gusts are possible near the end of
the period.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Hennecke
LONG TERM...53
AVIATION...Bowen
AREA FORECAST DISCUSSION
NWS GOODLAND KS
933 AM MDT THU JUL 24 2014
.UPDATE...
ISSUED AT 924 AM MDT THU JUL 24 2014
CURRENT NEAR TERM FORECAST CONCERNS FOCUS ON HOW WARM THINGS WILL
GET THIS AFTERNOON COMBINED WITH MAGNITUDE OF DEWPOINT FALLS AS
DRYLINE DEVELOPS THIS AFTERNOON.
LATEST RAP AND HRRR AND TO A LESSER DEGREE THE NAM ARE SUPPORTING
A WELL MIXED VERY WARM PATTERN ACROSS THE CWA PUSHING HIGHS ABOVE
105 IN SEVERAL LOCATIONS. NOT TOTALLY SOLD ON THIS AS MODELS ARE
AGGRESSIVELY MIXING THINGS FASTER THAN CURRENT OBSERVATIONS. GOES
SOUNDER DATA DOES INDICATE AN AREA OF LOW PW`S NOSING INTO THE
WESTERN CWA AS OF 14Z...WHICH WOULD SUPPORT A LAYER OF DRIER AIR
OFF OF THE SURFACE WHICH COULD POTENTIALLY DILUTE SFC TDS THIS
AFTERNOON. HAVE LOWERED BOTH THE TD AND RAISED TEMPS A FEW DEGREES
BASED ON LATEST DATA AND WILL CLOSELY MONITOR TRENDS TO SEE IF
MUCH WARMER TEMPS ARE NEEDED.
GIVEN DRY AIR AND INCREASING SOUTHWESTERLY WINDS...FIRE WX MAY
BECOME A LARGE CONCERN THIS AFTERNOON ESPECIALLY NEAR RECENTLY
HARVESTED OR READY FOR HARVEST WHEAT FIELDS. CURRENTLY WIDESPREAD
CRITICAL FUELS ARE IN QUESTION THOUGH SO NOT SURE A RFW IS VALID
AT THIS POINT IN THE GREEN UP CYCLE. FOR THE TIME BEING...PLAN ON
HIGHLIGHTING POTENTIALLY CRITICAL LOCAL FIRE DANGER IN SPS FOR NOW
UNTIL FUEL INFORMATION BECOMES MORE APPARENT.
UPDATE ISSUED AT 630 AM MDT THU JUL 24 2014
SMALL AREA OF LOW STRATUS AND MINOR FOG HAS DEVELOPED TO THE EAST
OF SURFACE TROUGH STRETCHING FROM GARDEN CITY TO RUSSEL SPRINGS.
THIS IS NOT A PARTICULARLY WIDE AREA AND THINK MORNING SUN SHOULD
HELP MIX OUT FOG AND LOWER CLOUDS FAIRLY QUICKLY.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 324 AM MDT THU JUL 24 2014
FORECAST PROBLEMS WILL BE CHANCES OF PRECIPITATION AND HOW HOT DOES
IT GET. SATELLITE SHOWING AN AMPLIFIED PATTERN FROM THE EASTERN
PACIFIC INTO THE WESTERN ATLANTIC. STRONG RIDGE CENTERED TO OUR
SOUTHWEST IS STARTING TO BE PUSHED SOUTH BY A STRONG UPPER SYSTEM
THAT IS NOW MOVING INTO THE PACIFIC NORTHWEST. STALLED FRONTAL
BOUNDARY IS NEAR THE WESTERN END OF OUR AREA.
AT MID LEVELS...MODELS TENDED TO BE A LITTLE TOO FAR EAST...
ESPECIALLY WITH THE PACIFIC NORTHWEST SYSTEM. OVERALL THE ECMWF WAS
DOING A LITTLE BETTER THAN THE GFS AND UKMET. AT LOW LEVELS...THE
ECMWF AND SREF WERE DOING THE BEST. THE ECMWF WAS DOING A LITTLE
BETTER ON THE LOW LEVEL THERMAL FIELD.
TODAY/TONIGHT...SURFACE TROUGH AND SHORTWAVE TROUGH MOVE INTO THE
WESTERN PORTION OF THE FORECAST AREA LATER THIS AFTERNOON. THERE IS
A DEEP DRY LAYER SHOWN BY THE MODEL SOUNDINGS WITH 700 MB
TEMPERATURES GREATER THAN +15. WILL KEEP A SLIGHT CHANCE OF
PRECIPITATION BUT PULL THE SLIGHT CHANCE BACK FURTHER WEST TOWARD
THE LIFT. THIS ALSO MATCHES WITH GEFS PROBABILITIES. NEW GUIDANCE
SUPPORTED ONLY MAKING SLIGHT ADJUSTMENTS TO THE HIGH TEMPERATURES.
QUESTION THEN BECOMES HOW FAR EAST DOES IT GO DURING THE NIGHT.
INITIALLY MOST OF THE LIFT ALOFT GOES ACROSS THE NORTHWEST HALF
DURING THE EVENING. HOWEVER...THE SURFACE TROUGH AND REMAINDER OF THE
SHORTWAVE GOES ACROSS DURING THE NIGHT. SINCE LIFT DOES NOT LOOK THAT
STRONG RIGHT NOW AND THERE IS A DEEP DRY LAYER WILL CONTINUE WHAT THE
DAY SHIFT PUT IN WHICH IS THE SLIGHT CHANCE ACROSS THE NORTHWEST HALF
DURING THE EVENING. THIS ALSO MATCHES WITH THE PROBABILITY FORECAST
WHICH DOES KEEP MEASURABLE A LITTLE FURTHER WEST AS WELL.
FRIDAY/FRIDAY NIGHT...MODELS NOW APPEAR A LITTLE SLOWER WITH THE
COLD FRONT...BEING PUSHED BY NORTHERN SYSTEM. IN FACT MOST OF THEM
STALL THE FRONT OVER THE CENTRAL/SOUTHEAST PORTION BY LATE IN THE
AFTERNOON. THIS THEN LOOKS TO PULL BACK TO THE NORTH DURING THE
EVENING BEFORE COMING THROUGH IN THE LATER HALF OF THE NIGHT.
ALSO A WEAKER SHORTWAVE WILL MOVE ACROSS WHERE THE FRONT WILL BE IN
THE AFTERNOON. AFTER THAT A MUCH STRONGER SHORTWAVE MOVES IN FROM
THE WEST DURING THE NIGHT. COMPLICATE THAT WITH 700 MB TEMPERATURES
NEAR OR ABOVE PLUS 15 AND A DEEP DRY LAYER IN THE BOTTOM HALF OF
THE ATMOSPHERE. STORM MOTIONS WILL BE VERY SLOW AS WELL. SO COULD
POSSIBLY HAVE THUNDERSTORMS DEVELOP NEAR/JUST WEST OF THE BOUNDARY
AND/OR COME OFF THE HIGHER TERRAIN TO THE WEST DUE TO THE SHORTWAVE
AND SOME UPSLOPE FLOW. WILL PUT SOME SLIGHT CHANCE POPS WITH THE
FRONT IN THE AFTERNOON.
QUESTION ONCE AGAIN IS HOW FAR EAST DOES THE CONVECTION GO AND HOW
LONG IT GOES INTO THE NIGHT. MODEL QPF AND PROBABILITY FORECASTS
TEND TO FAVOR THE WESTERN PORTION OF THE AREA AND TO OUR NORTH. RIGHT
THE CURRENT FORECAST IN THE EVENING LOOKS REASONABLE AND ONLY MADE A
SLIGHT ADJUSTMENT. HOWEVER WITH THE BOUNDARY AND DECENT LIFT MOVING
THROUGH IN THE LATTER HALF OF THE NIGHT...WILL INSERT A SLIGHT CHANCE
IN THE SOUTHEAST HALF.
HIGH TEMPERATURES WILL BE INTERESTING DEPENDING ON THE SPEED AND
POSITION OF THE FRONT. SINCE MODELS ARE SLOWER WITH THE FRONT...
MODEL TEMPERATURES ARE WARMER THAN THEY WERE YESTERDAY...ESPECIALLY
IN THE SOUTHEAST PORTION OF THE AREA. SO ENDED UP RAISING MAXES...
ESPECIALLY IN THE SOUTHEAST HALF.
SATURDAY/SATURDAY NIGHT...AT THIS TIME IT LOOKS LIKE THE FRONT IS
THROUGH THE ENTIRE AREA...NOT BY MUCH...BY EARLY AFTERNOON. SO AIR
MASS WILL BE COOLER WITH SOME WEAK UPSLOPE OCCURRING. THIS FRONT
CONTINUES TO MOVE SOUTH AND EAST THROUGH THE NIGHT. WITH THE FRONT
THROUGH THE AREA BELIEVE INITIALLY THAT THE PRECIPITATION WILL BE
TIED TO IT WITH THE MAIN AREA SOUTH AND EAST OF THE FORECAST AREA.
IT WILL BE POSSIBLE THAT THE FAR WEST WILL SEE SOME STORMS WITH THE
NEXT SHORTWAVE TROUGH APPROACHING THE POST FRONTAL UPSLOPE AIR
MASS. SO REDUCED POPS TO JUST THAT AREA IN THE AFTERNOON.
SHORTWAVE TROUGH MOVING THROUGH DURING THE NIGHT. BUT MODELS
DISAGREE ON WHERE THE BEST LIFT AND HOW MUCH INSTABILITY WILL BE
PRESENT. OVERALL SETUP AND PROBABILITIES SUPPORT THE SOUTHWEST HALF
OF THE FORECAST AREA AT THIS TIME. SO LEFT THE CURRENT FORECAST
ALONE.
EVEN THOUGH MOST OF THE AREA IS BEHIND THE FRONT BY SHORTLY AFTER
18Z...MODELS DISAGREE ON HOW MUCH COOLER AIR TO BRING INTO THE
AREA. ONCE AGAIN THE FURTHER NORTH AND WEST YOU GO...THE LESS HOT IT
WILL BE. AGAIN THE SOUTHEAST WILL SEE THE HOTTEST TEMPERATURES.
MADE ONLY MINOR ADJUSTMENTS TO ONGOING FORECAST.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 150 AM MDT THU JUL 24 2014
FOR THE EXTENDED PERIOD...REGION WILL SEE PATTERN SHIFT AS MODELS
BEGIN TO STRENGTHEN H5/H7 RIDGES OVER THE WESTERN PORTIONS OF THE
COUNTRY...COUNTERACTED WITH A DEEPENING TROUGH/UPPER LOW SETTING UP
OVER THE GREAT LAKES/NORTHEAST REGIONS. UPPER FLOW AS A RESULT WILL
BE NORTHWEST OVER THE AREA FOR THE ENTIRE EXTENDED TIME FRAME. AT
THE SURFACE...A SERIES OF WEAK WAVES WILL MOVE OFF THE EASTERN
PORTION OF THE ROCKIES FOR SUNDAY INTO MONDAY NIGHT...FOLLOWED BY A
STRONGER LEE-SIDE TROUGH THAT SETS UP ON TUESDAY...SETTLING SOUTH OF
REGION EARLY WEDNESDAY AND THEN CONVERTING TO INVERTED TROUGH AND
MEANDER OF THE REGION THROUGH WEDNESDAY. THE RESULT OF THE SYNOPTIC
SETUP WILL BRING CHANCE FOR TRW/RW ALMOST EVERY DAY WITH BEST
CHANCES BEING TUESDAY INTO WEDNESDAY AND THIS IS WHERE HIGHEST POPS
(30-40) ARE HIGHLIGHTED...BEFORE THINGS WIND DOWN WEDNESDAY NIGHT
INTO THURSDAY. AS A RESULT OF THE BROAD NW UPPER FLOW AND EXPECTED
CLOUD COVER...TEMPERATURES WILL BE GENERALLY A FEW DEGREES BELOW
NORMAL WITH HIGHS IN THE 80S TO LOW 90S IN SPOTS. OVERNIGHT LOWS WILL
RANGE IN THE LOW/MID 60S AND WILL BE HAMPERED AT TIMES IF ANY
RESIDUAL CLOUDS REMAIN FROM CONVECTION DURING THE AFTERNOON/EVENING
HOURS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 515 AM MDT THU JUL 24 2014
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. SOME THIN AND
SHALLOW MAY BE AROUND FOR A VERY SHORT PERIOD OF TIME AFTER 12Z.
ONCE ENOUGH HEATING TAKES PLACE THE SOUTHERLY WINDS WILL BE GUSTY
WITH KGLD HAVING THE STRONGEST WINDS. SOME ISOLATED THUNDERSTORMS
ARE POSSIBLE LATE THIS AFTERNOON INTO THIS EVENING. SINCE IT IS
LATE IN THE PERIOD...AND COVERAGE LOOKS VERY SPOTTY...WILL NOT
INCLUDE ANY MENTION IN THE TAFS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JRM
SHORT TERM...BULLER
LONG TERM...JN
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS TOPEKA KS
636 AM CDT Thu Jul 24 2014
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 349 AM CDT THU JUL 24 2014
Water vapor imagery this morning showed the broad mid-level ridge
still anchored across the Rockies, resulting in northwesterly aloft
across the forecast area. A few weak embedded shortwaves were noted
along the northern edge of the ridge axis over South Dakota. While
these waves should progress southeastward along the ridge axis, most
models show any precipitation that develops from these waves to
remain north of the forecast area. It`s worth noting though that
recent early morning runs of the HRRR and RAP have started to show
precipitation from these shortwaves diving further south along the
Nebraska/Iowa border and skimming near far northeast Kansas by this
afternoon. However, due to the agreement of the synoptic models in
keeping precipitation north of the area and with the fairly poor
performance of these short-range models over the last few days, have
gone with a dry forecast for today but will continue to monitor
these shortwaves through the day.
Surface high pressure was situated over the region early this
morning, resulting in light winds, mostly clear skies, and cooler
conditions as temperatures dropped into the 60s. This surface high
gradually will shift eastward toward the Ohio River Valley, with
winds shifting to the southeast today and further to the south
overnight. These southeasterly winds today will keep temperatures
near or slightly below the seasonal normals as afternoon highs
should reach into the mid 80s east to low 90s west.
Water vapor imagery showed a mid-level trough and closed-off low
moving onshore in the Pacific Northwest, and models show this low
progressing eastward along the U.S./Canadian border over the next
few days. This advancing low will help to flatten the mid-level
ridge currently in place, resulting in the area of surface low
pressure currently over the northern Rockies being pushed southward
into the High Plains tonight. Model soundings show high clouds
building in over the region tonight, so this cloud cover combined
with southerly winds will result in better insolation and keep low
temperatures tonight a few degrees warmer in the upper 60s to mid
70s.
.LONG TERM...(Friday through Wednesday)
Issued at 349 AM CDT THU JUL 24 2014
Friday, the upper level ridge builds into northeast Kansas with the
edge of the westerlies over Missouri and Iowa. Thermal axis will
develop across the Central Plains ahead of a surface trough/front
that is expected to slowly move across Nebraska and into north
central Kansas by Friday evening. Dew point temperatures in the
middle 60s in north central Kansas and near 70 in northeast Kansas
will combine with afternoon temperatures from the upper 90s in far
eastern counties to around 105 toward central Kansas to produce
afternoon heat indices of 104 to 109 and will likely need a heat
advisory for the day on Friday.
The frontal boundary will slowly move south Saturday and Saturday
night settling in southern Kansas by Sunday morning as the upper
level ridge is suppressed westward as an upper level trough moves
across southern Canada and the Northern Plains. A unstable airmass
develops across northern Kansas Saturday with CAPE of 2500-5000 J/kg
and moderate shear. Soundings show inverted V cap eroding by late
afternoon and could see some isolated thunderstorms developing. If
they do develop then damaging wind gusts will be the main hazard.
Saturday will be a little cooler than Friday due to the presence of
mid and upper level clouds. However temperatures will range from
the lower 90s along the Nebraska border to around 101 near central
Kansas. Dew points in the upper 60s to around 70 will combine with
the temperatures to produce heat indices of 99 to 104.
Cooler temperatures and dry weather are expected on Sunday in the
wake of the front and this should continue into mid week with
northwest flow aloft and high pressure over much of the Central
Plains. The next chance of precipitation comes Tuesday night and
Wednesday with the western counties having the best chances. Both
the GFS and ECMWF indicate mid level waves moving through the
northwest flow.
&&
.AVIATION...(For the 12Z TAFs through 12Z Friday Morning)
Issued at 636 AM CDT THU JUL 24 2014
For the 12z TAFs, VFR conditions are expected through the period.
Calm winds this morning will increase out of the southeast today and
persist at roughly 8-10kts through the afternoon and evening hours.
Expect the wind direction to begin shifting more to the south by
Friday morning as the next system approaches the region.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Hennecke
LONG TERM...53
AVIATION...Hennecke
AREA FORECAST DISCUSSION
NWS TOPEKA KS
349 AM CDT Thu Jul 24 2014
.SHORT TERM...(Today and Tonight)
Issued at 349 AM CDT THU JUL 24 2014
Water vapor imagery this morning showed the broad mid-level ridge
still anchored across the Rockies, resulting in northwesterly aloft
across the forecast area. A few weak embedded shortwaves were noted
along the northern edge of the ridge axis over South Dakota. While
these waves should progress southeastward along the ridge axis, most
models show any precipitation that develops from these waves to
remain north of the forecast area. It`s worth noting though that
recent early morning runs of the HRRR and RAP have started to show
precipitation from these shortwaves diving further south along the
Nebraska/Iowa border and skimming near far northeast Kansas by this
afternoon. However, due to the agreement of the synoptic models in
keeping precipitation north of the area and with the fairly poor
performance of these short-range models over the last few days, have
gone with a dry forecast for today but will continue to monitor
these shortwaves through the day.
Surface high pressure was situated over the region early this
morning, resulting in light winds, mostly clear skies, and cooler
conditions as temperatures dropped into the 60s. This surface high
gradually will shift eastward toward the Ohio River Valley, with
winds shifting to the southeast today and further to the south
overnight. These southeasterly winds today will keep temperatures
near or slightly below the seasonal normals as afternoon highs
should reach into the mid 80s east to low 90s west.
Water vapor imagery showed a mid-level trough and closed-off low
moving onshore in the Pacific Northwest, and models show this low
progressing eastward along the U.S./Canadian border over the next
few days. This advancing low will help to flatten the mid-level
ridge currently in place, resulting in the area of surface low
pressure currently over the northern Rockies being pushed southward
into the High Plains tonight. Model soundings show high clouds
building in over the region tonight, so this cloud cover combined
with southerly winds will result in better insolation and keep low
temperatures tonight a few degrees warmer in the upper 60s to mid
70s.
.LONG TERM...(Friday through Wednesday)
Issued at 349 AM CDT THU JUL 24 2014
Friday, the upper level ridge builds into northeast Kansas with the
edge of the westerlies over Missouri and Iowa. Thermal axis will
develop across the Central Plains ahead of a surface trough/front
that is expected to slowly move across Nebraska and into north
central Kansas by Friday evening. Dew point temperatures in the
middle 60s in north central Kansas and near 70 in northeast Kansas
will combine with afternoon temperatures from the upper 90s in far
eastern counties to around 105 toward central Kansas to produce
afternoon heat indices of 104 to 109 and will likely need a heat
advisory for the day on Friday.
The frontal boundary will slowly move south Saturday and Saturday
night settling in southern Kansas by Sunday morning as the upper
level ridge is suppressed westward as an upper level trough moves
across southern Canada and the Northern Plains. A unstable airmass
develops across northern Kansas Saturday with CAPE of 2500-5000 J/kg
and moderate shear. Soundings show inverted V cap eroding by late
afternoon and could see some isolated thunderstorms developing. If
they do develop then damaging wind gusts will be the main hazard.
Saturday will be a little cooler than Friday due to the presence of
mid and upper level clouds. However temperatures will range from
the lower 90s along the Nebraska border to around 101 near central
Kansas. Dew points in the upper 60s to around 70 will combine with
the temperatures to produce heat indices of 99 to 104.
Cooler temperatures and dry weather are expected on Sunday in the
wake of the front and this should continue into mid week with
northwest flow aloft and high pressure over much of the Central
Plains. The next chance of precipitation comes Tuesday night and
Wednesday with the western counties having the best chances. Both
the GFS and ECMWF indicate mid level waves moving through the
northwest flow.
&&
.AVIATION...(For the 06Z TAFs through 06Z Thursday Night)
Issued at 1147 PM CDT WED JUL 23 2014
Expect VFR conditions. Any isolated thunderstorms during morning
hours will remain north of the terminals. Winds will become
southeast at 8 to 12 KTS with higher gusts after 14Z and continue
through the afternoon and evening.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Hennecke
LONG TERM...53
AVIATION...Gargan
AREA FORECAST DISCUSSION
NWS JACKSON KY
143 PM EDT THU JUL 24 2014
.UPDATE...
ISSUED AT 1235 PM EDT THU JUL 24 2014
SHOWERS HAVE FILLED IN OVER SOUTHEAST KENTUCKY A LITTLE MORE THAN
PREVIOUSLY FORECAST SO INCREASED POPS FOR A COUPLE HOURS BUT KEPT
WITH THE IDEA OF A DIMINISHING TREND IN THE SHOWER ACTIVITY FROM
WEST TO EAST THROUGH THE AFTERNOON AS THE RESPONSIBLE AREA OF LOW
PRESSURE PUSHES EAST. THIS TREND APPEARS LIKE IT WILL RESULT IN ALL
OF THE SHOWER ACTIVITY SHIFTING EAST OF OUR FORECAST AREA BY 00Z AND
REMOVED ALL MENTION OF PRECIP FOR TONIGHT.
NEXT BIG QUANDARY IS HOW MUCH CLOUD COVER WILL HANG IN PLACE TONIGHT
OR HOW MUCH FOG WILL DEVELOP SHOULD SKIES CLEAR. 12Z NAM INDICATES
THE POTENTIAL FOR CONSIDERABLE LOW CLOUDS TO HANG IN THROUGH THE
NIGHT WHILE OTHER MODELS SHOW THE LOW CLOUDS DISSIPATING. WITH LOW
LEVEL FLOW VEERING AROUND TO A NORTHEASTERLY DIRECTION THROUGH THE
NIGHT...WOULD TEND TO LEAN TOWARD THE NAM SOLUTION WITH MORE LOW
CLOUDS AND LESS FOG.
UPDATE ISSUED AT 1107 AM EDT THU JUL 24 2014
WEAK LOW PRESSURE IS TRACKING SLOWLY ACROSS SOUTHEAST KENTUCKY WITH
NORTHERLY WINDS STARTING TO PULL DRIER AIR INTO OUR NORTHERN
COUNTIES. SCATTERED SHOWERS CONTINUE TO PLAGUE AREAS SOUTH OF I-64
ALONG WITH AN OCCASIONAL ISOLATED THUNDERSTORM. THESE WILL GRADUALLY
PULL EAST AS THE LOW PRESSURE DEPARTS TO THE EAST DURING THE
AFTERNOON WITH DECREASING RAIN CHANCES EXPECTED FROM WEST TO EAST
THROUGH THE AFTERNOON. CLOUD COVER WILL LIKELY HANG IN TOUGH THROUGH
MOST OF THE DAY WITH CU DEVELOPING QUICKLY WHERE ANY BREAKS DEVELOP
DURING THE AFTERNOON.
UPDATE ISSUED AT 540 AM EDT THU JUL 24 2014
UPDATED THE FORECAST TO ADD AREAS OF DENSE FOG INTO THE GRIDS FOR
THIS MORNING GIVEN THE OBSERVATIONS AND WEB CAMS. THE LIGHT WINDS AND
MOIST BOUNDARY LAYER IS RESULTING IN NUMEROUS PLACES WITH VISIBILITY
BELOW A QUARTER OF A MILE. THE FOG SHOULD START TO BREAK UP BY 8 AM.
ALSO FINE TUNED THE T AND TD GRIDS PER THE LATEST OBS AND TRENDS. THE
GRIDS...AN SPS...UPDATED ZONES...AND HWO HAVE BEEN ISSUED.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 325 AM EDT THU JUL 24 2014
06Z SFC ANALYSIS SHOWS A WEAK AREA OF LOW PRESSURE OVER EAST KENTUCKY
ALONG A COLD FRONT THAT IS GRADUALLY SETTLING THROUGH THE CWA. THIS
BOUNDARY AND LOW IS RESPONSIBLE FOR THE SHOWERS AND STORMS WE SAW
EARLIER IN THE EVENING AND THE ONES THAT STILL LINGER OVER NORTH
CENTRAL KENTUCKY. NORTHWEST OF THIS FRONT...A COOL AND DRY AREA OF
HIGH PRESSURE IS IN PLACE OVER THE MIDWEST ON FINAL APPROACH TO EAST
KENTUCKY...SCHEDULED TO ARRIVE BY THURSDAY EVENING. MEANWHILE...
SCATTERED SHOWERS AND STORMS WILL REMAIN A THREAT THROUGH THE REST OF
THE MORNING AND INTO THE START OF THURSDAY. PATCHY FOG AND PLENTY OF
LOW CLOUDS ARE FOUND THROUGH EAST KENTUCKY AT THE MOMENT...AS WELL.
THIS ALL IS EXPECTED TO LINGER THROUGH SUNRISE AS TEMPERATURES AND
DEWPOINTS STAY ABOUT WHERE THEY ARE CURRENTLY...IN THE UPPER 60S AND
LOWER 70S. SIMILARLY...THE WINDS WILL REMAIN LIGHT AND VARIABLE WELL
INTO THE DAY THURSDAY.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM AS THEY
ALL SHIFT THE EASTERN TROUGH SLIGHTLY NORTHEAST IN RESPONSE TO A
FLATTENING OF THE STRONG WESTERN RIDGE. LEADING OFF THIS TRANSITION
ARE A COUPLE OF SHORTWAVES THAT WILL CROSS THE SOUTHERN OHIO VALLEY
AND KENTUCKY INTO THE AFTERNOON THURSDAY. RISING HEIGHTS WILL FOLLOW
LATER TONIGHT AND THROUGH THE DAY FRIDAY HELPING TO KEEP ANY ENERGY
PACKETS IN THE NORTHWEST FLOW FROM AMOUNTING TO MUCH OVER OUR AREA.
WITH THE MODEL AGREEMENT HAVE FAVORED THE HRRR AND NAM12 SOLUTIONS
FOR THE FORECAST TODAY AND THEN A GENERAL MODEL BLEND INTO FRIDAY. OF
NOTE...BOTH THE NAM12 AND THE ECMWF DO MAKE MORE OUT OF A BAND OF
PCPN THAT THEY FORECAST TO ACCOMPANY THE COLD FRONT AS IT EXITS LATER
TODAY...IN COMPARISON TO THAN THE GFS AND GEM.
SENSIBLE WEATHER WILL FEATURE SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS SLOWLY EXITING EAST KENTUCKY AS A SFC WAVE AND COLD
FRONT DEPARTS TO THE SOUTHEAST BY LATE AFTERNOON. COOLER AIR WITH
THIS BOUNDARY...LOW CLOUDS...AND THE PCPN WILL KEEP TEMPERATURES ONLY
IN THE 70S TODAY. HIGH PRESSURE THEN SETTLES INTO THE AREA TONIGHT
WITH DRIER AIR AND EVEN COOLER TEMPERATURES. THE MAIN QUESTION FOR
TONIGHT WILL BE HOW MUCH CLOUD COVER WILL REMAIN OVER EAST KENTUCKY
IN THE WAKE OF THE FRONT. THE TIME SECTIONS FROM THE NAM12 SUGGEST
THAT LOW CLOUDS WILL BE TOUGH TO CLEAR THROUGH DAWN SO HAVE GONE
CLOUDIER WITH THE GRIDS...WITH LIMITED RADIATIONAL COOLING AND FOG
ANTICIPATED FOR THIS REASON. THESE CLOUDS SHOULD START TO BREAK UP
MORE EFFECTIVELY ON FRIDAY ALLOWING FOR A WARMUP BACK INTO THE LOW
80S...ALONG WITH PLEASANT HUMIDITY LEVELS.
HAVE USED THE CONSSHORT AS A STARTING POINT FOR TEMPERATURES...
DEWPOINTS...AND WINDS THROUGH THE FIRST 24 HOURS AND THEN THE CONSALL
THEREAFTER. AS FOR POPS...HAVE ENDED UP ON THE HIGH SIDE OF THE MOS
NUMBERS...CLOSER TO THE MET...TODAY WITH LOW POPS TONIGHT AND
FRIDAY...IN LINE WITH THE GUIDANCE.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 350 AM EDT THU JUL 24 2014
THE EXTENDED PORTION OF THE FORECAST BEGINS ON FRIDAY NIGHT WITH A
CONTINUED AND PRONOUNCED RIDGE OVER THE WEST AND DEEPENING TROUGH
OVER THE EASTERN CONUS. BOTH THE GFS AND EURO HINT AT A POSSIBLE
WEAKENING MCS TRAVERSING OVER THE RIDGE AND THROUGH THE UPPER MS
RIVER VALLEY AND INTO THE OH VALLEY ON FRIDAY NIGHT. FOLLOWING THIS
WILL BE A STRONG SHORT WAVE MOVING SOUTHEAST FROM MN AND INTO THE OH
VALLEY BY SUNDAY AND SUNDAY NIGHT. AS THIS WAVE SWINGS THROUGH THE
BASE OF THE TROUGH...A 90 KNOT JET MAX WILL PUSH THROUGH DEEPENING
THE LONG WAVE TROUGH OVER THE EASTERN CONUS AND KEEPING THE QUITE
AMPLIFIED TROUGH IN PLACE THROUGH THE REST OF THE EXTENDED. IN
RESPONSE...THE WESTERN RIDGE INCREASES IN STRENGTH KEEPING A RARE
MERIDIONAL PATTERN IN PLACE FOR THIS TIME OF YEAR. WITH THE MODELS
SHOWING SOME AGREEMENT IN THIS TREND IT CAN BE SAFE TO SHOW A HIGH
LEVEL OF CONFIDENCE WITH THE ALL MODEL BLEND SOLUTION.
FOR SOME MORE DETAILS IN THE LOWER LEVELS...THE MODELS SEEM TO BE IN
AGREEMENT WITH THE DECAYING MCS MAKING IT INTO THE AREA FRIDAY
NIGHT. THIS SHOULD ERODE THE ADVERTISED CAP THROUGH FRIDAY NIGHT AND
ALLOW SOME ADDITIONAL DEVELOPMENT INTO THE DAY ON SATURDAY WITH
DECENT INSTABILITY AVAILABLE AND SOME UPPER LEVEL SUPPORT ARRIVING
AHEAD OF A POTENT SHORTWAVE. THE BEST CHANCE FOR SHOWER AND
THUNDERSTORM DEVELOPMENT WILL COME ON SUNDAY AND INTO MONDAY WITH A
STRONG COLD FRONT MOVING THROUGH. WENT WITH THE LIKELY POPS
INHERITED FROM THE ALL MODEL BLEND. AT AN EARLY LOOK TO THIS
SCENARIO...QUITE A BIT OF DYNAMICS ARE WITH THIS FEATURE WITH THE
STRONG JET STREAK MOVING THROUGH THE OH VALLEY AND AFTERNOON CAPE
VALUES REACHING 2500 J/KG...A SEVERE WEATHER THREAT IS CERTAINLY NOT
OUT OF THE QUESTION IF THE STRENGTH OF THE WAVE HOLDS TRUE THROUGH
THE DAYS LEADING UP TO THE EVENT. THIS WILL BE THE REAL FORECAST
CHALLENGE AS THE POTENTIAL IS THERE...BUT WILL HAVE TO SEE HOW THE
MODELS TREND UP TO THE EVENT. A COUPLE WEAK DISTURBANCES WILL FOLLOW
BEHIND THIS WAVE AND WILL PROVIDE A LOW CHANCE FOR PRECIP INTO
TUESDAY BEFORE HIGH PRESSURE SETTLES IN FOR THE REST OF THE
EXTENDED. THE AIR MASS MOVING IN BEHIND THIS FRONT IS QUITE COOL
WITH HIGH TEMPERATURES FOR MONDAY THROUGH WEDNESDAY IN THE MID
70S...AROUND 10 DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. MODEL
TRENDS WOULD SUGGEST THAT AN OVERALL COOLER PATTERN FOR THE LAST
WEEK OF JULY WILL BE THE CASE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 143 PM EDT THU JUL 24 2014
DIFFICULT AVIATION FORECAST WITH LOW CONFIDENCE IN DETAILS AT THIS
TIME. LOW CLOUDS CURRENTLY IN PLACE WILL SLOWLY LIFT AND ERODE
AROUND THE WESTERN AND NORTHERN EDGES THROUGH THE AFTERNOON AS LOW
PRESSURE TRACKS OUT OF FAR EAST KENTUCKY INTO THE VIRGINIAS. DRIER
AIR WILL WORK INTO THE REGION ON NORTHERLY WINDS AND RESIDUAL SHOWER
ACTIVITY OVER FAR SOUTHEAST KENTUCKY WILL END BY EVENING. LOW LEVEL
FLOW WILL VEER AROUND TO A NORTHEASTERLY DIRECTION WITH TIME
OVERNIGHT. THIS TYPICALLY RESULTS IN A TENDENCY FOR LOW CLOUDS TO
HANG IN TOUGH OVER EASTERN KENTUCKY...OR REDEVELOP IF THEY BREAK UP
FOR A TIME DURING THE EVENING. SO...WHILE FLIGHT CONDITIONS WILL
GRADUALLY IMPROVE THIS AFTERNOON AND EVENING...IT IS LIKELY THEY
WILL DETERIORATE AGAIN AFTER MIDNIGHT WITH A PROLONGED PERIOD OF
LIFR OR LOWER CONDITIONS LIKELY AROUND DAWN ON FRIDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...ABE
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...ABE
AREA FORECAST DISCUSSION
NWS JACKSON KY
1235 PM EDT THU JUL 24 2014
.UPDATE...
ISSUED AT 1235 PM EDT THU JUL 24 2014
SHOWERS HAVE FILLED IN OVER SOUTHEAST KENTUCKY A LITTLE MORE THAN
PREVIOUSLY FORECAST SO INCREASED POPS FOR A COUPLE HOURS BUT KEPT
WITH THE IDEA OF A DIMINISHING TREND IN THE SHOWER ACTIVITY FROM
WEST TO EAST THROUGH THE AFTERNOON AS THE RESPONSIBLE AREA OF LOW
PRESSURE PUSHES EAST. THIS TREND APPEARS LIKE IT WILL RESULT IN ALL
OF THE SHOWER ACTIVITY SHIFTING EAST OF OUR FORECAST AREA BY 00Z AND
REMOVED ALL MENTION OF PRECIP FOR TONIGHT.
NEXT BIG QUANDRY IS HOW MUCH CLOUD COVER WILL HANG IN PLACE TONIGHT
OR HOW MUCH FOG WILL DEVELOP SHOULD SKIES CLEAR. 12Z NAM INDICATES
THE POTENTIAL FOR CONSIDERABLE LOW CLOUDS TO HANG IN THROUGH THE
NIGHT WHILE OTHER MODELS SHOW THE LOW CLOUDS DISSIPATING. WITH LOW
LEVEL FLOW VEERING AROUND TO A NORTHEASTERLY DIRECTION THROUGH THE
NIGHT...WOULD TEND TO LEAN TOWARD THE NAM SOLUTION WITH MORE LOW
CLOUDS AND LESS FOG.
UPDATE ISSUED AT 1107 AM EDT THU JUL 24 2014
WEAK LOW PRESSURE IS TRACKING SLOWLY ACROSS SOUTHEAST KENTUCKY WITH
NORTHERLY WINDS STARTING TO PULL DRIER AIR INTO OUR NORTHERN
COUNTIES. SCATTERED SHOWERS CONTINUE TO PLAGUE AREAS SOUTH OF I-64
ALONG WITH AN OCCASIONAL ISOLATED THUNDERSTORM. THESE WILL GRADUALLY
PULL EAST AS THE LOW PRESSURE DEPARTS TO THE EAST DURING THE
AFTERNOON WITH DECREASING RAIN CHANCES EXPECTED FROM WEST TO EAST
THROUGH THE AFTERNOON. CLOUD COVER WILL LIKELY HANG IN TOUGH THROUGH
MOST OF THE DAY WITH CU DEVELOPING QUICKLY WHERE ANY BREAKS DEVELOP
DURING THE AFTERNOON.
UPDATE ISSUED AT 540 AM EDT THU JUL 24 2014
UPDATED THE FORECAST TO ADD AREAS OF DENSE FOG INTO THE GRIDS FOR
THIS MORNING GIVEN THE OBSERVATIONS AND WEB CAMS. THE LIGHT WINDS AND
MOIST BOUNDARY LAYER IS RESULTING IN NUMEROUS PLACES WITH VISIBILITY
BELOW A QUARTER OF A MILE. THE FOG SHOULD START TO BREAK UP BY 8 AM.
ALSO FINE TUNED THE T AND TD GRIDS PER THE LATEST OBS AND TRENDS. THE
GRIDS...AN SPS...UPDATED ZONES...AND HWO HAVE BEEN ISSUED.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 325 AM EDT THU JUL 24 2014
06Z SFC ANALYSIS SHOWS A WEAK AREA OF LOW PRESSURE OVER EAST KENTUCKY
ALONG A COLD FRONT THAT IS GRADUALLY SETTLING THROUGH THE CWA. THIS
BOUNDARY AND LOW IS RESPONSIBLE FOR THE SHOWERS AND STORMS WE SAW
EARLIER IN THE EVENING AND THE ONES THAT STILL LINGER OVER NORTH
CENTRAL KENTUCKY. NORTHWEST OF THIS FRONT...A COOL AND DRY AREA OF
HIGH PRESSURE IS IN PLACE OVER THE MIDWEST ON FINAL APPROACH TO EAST
KENTUCKY...SCHEDULED TO ARRIVE BY THURSDAY EVENING. MEANWHILE...
SCATTERED SHOWERS AND STORMS WILL REMAIN A THREAT THROUGH THE REST OF
THE MORNING AND INTO THE START OF THURSDAY. PATCHY FOG AND PLENTY OF
LOW CLOUDS ARE FOUND THROUGH EAST KENTUCKY AT THE MOMENT...AS WELL.
THIS ALL IS EXPECTED TO LINGER THROUGH SUNRISE AS TEMPERATURES AND
DEWPOINTS STAY ABOUT WHERE THEY ARE CURRENTLY...IN THE UPPER 60S AND
LOWER 70S. SIMILARLY...THE WINDS WILL REMAIN LIGHT AND VARIABLE WELL
INTO THE DAY THURSDAY.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM AS THEY
ALL SHIFT THE EASTERN TROUGH SLIGHTLY NORTHEAST IN RESPONSE TO A
FLATTENING OF THE STRONG WESTERN RIDGE. LEADING OFF THIS TRANSITION
ARE A COUPLE OF SHORTWAVES THAT WILL CROSS THE SOUTHERN OHIO VALLEY
AND KENTUCKY INTO THE AFTERNOON THURSDAY. RISING HEIGHTS WILL FOLLOW
LATER TONIGHT AND THROUGH THE DAY FRIDAY HELPING TO KEEP ANY ENERGY
PACKETS IN THE NORTHWEST FLOW FROM AMOUNTING TO MUCH OVER OUR AREA.
WITH THE MODEL AGREEMENT HAVE FAVORED THE HRRR AND NAM12 SOLUTIONS
FOR THE FORECAST TODAY AND THEN A GENERAL MODEL BLEND INTO FRIDAY. OF
NOTE...BOTH THE NAM12 AND THE ECMWF DO MAKE MORE OUT OF A BAND OF
PCPN THAT THEY FORECAST TO ACCOMPANY THE COLD FRONT AS IT EXITS LATER
TODAY...IN COMPARISON TO THAN THE GFS AND GEM.
SENSIBLE WEATHER WILL FEATURE SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS SLOWLY EXITING EAST KENTUCKY AS A SFC WAVE AND COLD
FRONT DEPARTS TO THE SOUTHEAST BY LATE AFTERNOON. COOLER AIR WITH
THIS BOUNDARY...LOW CLOUDS...AND THE PCPN WILL KEEP TEMPERATURES ONLY
IN THE 70S TODAY. HIGH PRESSURE THEN SETTLES INTO THE AREA TONIGHT
WITH DRIER AIR AND EVEN COOLER TEMPERATURES. THE MAIN QUESTION FOR
TONIGHT WILL BE HOW MUCH CLOUD COVER WILL REMAIN OVER EAST KENTUCKY
IN THE WAKE OF THE FRONT. THE TIME SECTIONS FROM THE NAM12 SUGGEST
THAT LOW CLOUDS WILL BE TOUGH TO CLEAR THROUGH DAWN SO HAVE GONE
CLOUDIER WITH THE GRIDS...WITH LIMITED RADIATIONAL COOLING AND FOG
ANTICIPATED FOR THIS REASON. THESE CLOUDS SHOULD START TO BREAK UP
MORE EFFECTIVELY ON FRIDAY ALLOWING FOR A WARMUP BACK INTO THE LOW
80S...ALONG WITH PLEASANT HUMIDITY LEVELS.
HAVE USED THE CONSSHORT AS A STARTING POINT FOR TEMPERATURES...
DEWPOINTS...AND WINDS THROUGH THE FIRST 24 HOURS AND THEN THE CONSALL
THEREAFTER. AS FOR POPS...HAVE ENDED UP ON THE HIGH SIDE OF THE MOS
NUMBERS...CLOSER TO THE MET...TODAY WITH LOW POPS TONIGHT AND
FRIDAY...IN LINE WITH THE GUIDANCE.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 350 AM EDT THU JUL 24 2014
THE EXTENDED PORTION OF THE FORECAST BEGINS ON FRIDAY NIGHT WITH A
CONTINUED AND PRONOUNCED RIDGE OVER THE WEST AND DEEPENING TROUGH
OVER THE EASTERN CONUS. BOTH THE GFS AND EURO HINT AT A POSSIBLE
WEAKENING MCS TRAVERSING OVER THE RIDGE AND THROUGH THE UPPER MS
RIVER VALLEY AND INTO THE OH VALLEY ON FRIDAY NIGHT. FOLLOWING THIS
WILL BE A STRONG SHORT WAVE MOVING SOUTHEAST FROM MN AND INTO THE OH
VALLEY BY SUNDAY AND SUNDAY NIGHT. AS THIS WAVE SWINGS THROUGH THE
BASE OF THE TROUGH...A 90 KNOT JET MAX WILL PUSH THROUGH DEEPENING
THE LONG WAVE TROUGH OVER THE EASTERN CONUS AND KEEPING THE QUITE
AMPLIFIED TROUGH IN PLACE THROUGH THE REST OF THE EXTENDED. IN
RESPONSE...THE WESTERN RIDGE INCREASES IN STRENGTH KEEPING A RARE
MERIDIONAL PATTERN IN PLACE FOR THIS TIME OF YEAR. WITH THE MODELS
SHOWING SOME AGREEMENT IN THIS TREND IT CAN BE SAFE TO SHOW A HIGH
LEVEL OF CONFIDENCE WITH THE ALL MODEL BLEND SOLUTION.
FOR SOME MORE DETAILS IN THE LOWER LEVELS...THE MODELS SEEM TO BE IN
AGREEMENT WITH THE DECAYING MCS MAKING IT INTO THE AREA FRIDAY
NIGHT. THIS SHOULD ERODE THE ADVERTISED CAP THROUGH FRIDAY NIGHT AND
ALLOW SOME ADDITIONAL DEVELOPMENT INTO THE DAY ON SATURDAY WITH
DECENT INSTABILITY AVAILABLE AND SOME UPPER LEVEL SUPPORT ARRIVING
AHEAD OF A POTENT SHORTWAVE. THE BEST CHANCE FOR SHOWER AND
THUNDERSTORM DEVELOPMENT WILL COME ON SUNDAY AND INTO MONDAY WITH A
STRONG COLD FRONT MOVING THROUGH. WENT WITH THE LIKELY POPS
INHERITED FROM THE ALL MODEL BLEND. AT AN EARLY LOOK TO THIS
SCENARIO...QUITE A BIT OF DYNAMICS ARE WITH THIS FEATURE WITH THE
STRONG JET STREAK MOVING THROUGH THE OH VALLEY AND AFTERNOON CAPE
VALUES REACHING 2500 J/KG...A SEVERE WEATHER THREAT IS CERTAINLY NOT
OUT OF THE QUESTION IF THE STRENGTH OF THE WAVE HOLDS TRUE THROUGH
THE DAYS LEADING UP TO THE EVENT. THIS WILL BE THE REAL FORECAST
CHALLENGE AS THE POTENTIAL IS THERE...BUT WILL HAVE TO SEE HOW THE
MODELS TREND UP TO THE EVENT. A COUPLE WEAK DISTURBANCES WILL FOLLOW
BEHIND THIS WAVE AND WILL PROVIDE A LOW CHANCE FOR PRECIP INTO
TUESDAY BEFORE HIGH PRESSURE SETTLES IN FOR THE REST OF THE
EXTENDED. THE AIR MASS MOVING IN BEHIND THIS FRONT IS QUITE COOL
WITH HIGH TEMPERATURES FOR MONDAY THROUGH WEDNESDAY IN THE MID
70S...AROUND 10 DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. MODEL
TRENDS WOULD SUGGEST THAT AN OVERALL COOLER PATTERN FOR THE LAST
WEEK OF JULY WILL BE THE CASE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 655 AM EDT THU JUL 24 2014
SCATTERED SHOWERS AND THE OCCASIONAL THUNDERSTORM WILL CONTINUE TO
SLOWLY DRIFT SOUTHEAST THROUGH THE MORNING. AREAS OF DENSE FOG ARE
AFFECTING MANY OF THE AIRPORTS THIS MORNING IN LIEU OF THE
CONVECTION. EXPECT VIS AND CIG CONDITIONS TO GRADUALLY IMPROVE
FOLLOWING SUNRISE. HAVE KEPT THUNDER AND EVEN VCTS OUT OF THE TAFS AS
THE INSTABILITY WILL BE FAIRLY LOW THROUGH THE DAY...THOUGH A STRAY
STORM CANNOT BE RULED OUT. THE LATEST HRRR AND NAM12 CONTINUE TO
INDICATE THAT THE CURRENT BAND OF CONVECTION ALONG THE FRONT WILL
HOLD TOGETHER AS IT MAKES ITS FINAL PUSH ACROSS THE AREA. HAVE
A VCSH FOR THIS IN ALL SITES WITH CIGS GENERALLY AROUND 2K FEET. IN
THE WAKE OF THE FRONT LATER THIS EVENING...DRIER AIR IS EXPECTED TO
LIFT THE CIGS AND REMOVE THE THREAT OF SHOWERS. WINDS THROUGH THE
PERIOD WILL BE MAINLY LIGHT AND VARIABLE...THOUGH FAVORING THE
NORTHERLY DIRECTION LATER TODAY AND INTO THE EVENING. PATCHY FOG WILL
BE A CONCERN LATER TONIGHT AS WELL...BUT GENERALLY ONLY IF WE MANAGE
TO CLEAR OUT. FOR NOW WILL LEAVE THIS OUT OF THE TAFS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...ABE
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS JACKSON KY
1107 AM EDT THU JUL 24 2014
.UPDATE...
ISSUED AT 1107 AM EDT THU JUL 24 2014
WEAK LOW PRESSURE IS TRACKING SLOWLY ACROSS SOUTHEAST KENTUCKY WITH
NORTHERLY WINDS STARTING TO PULL DRIER AIR INTO OUR NORTHERN
COUNTIES. SCATTERED SHOWERS CONTINUE TO PLAGUE AREAS SOUTH OF I-64
ALONG WITH AN OCCASIONAL ISOLATED THUNDERSTORM. THESE WILL GRADUALLY
PULL EAST AS THE LOW PRESSURE DEPARTS TO THE EAST DURING THE
AFTERNOON WITH DECREASING RAIN CHANCES EXPECTED FROM WEST TO EAST
THROUGH THE AFTERNOON. CLOUD COVER WILL LIKELY HANG IN TOUGH THROUGH
MOST OF THE DAY WITH CU DEVELOPING QUICKLY WHERE ANY BREAKS DEVELOP
DURING THE AFTERNOON.
UPDATE ISSUED AT 540 AM EDT THU JUL 24 2014
UPDATED THE FORECAST TO ADD AREAS OF DENSE FOG INTO THE GRIDS FOR
THIS MORNING GIVEN THE OBSERVATIONS AND WEB CAMS. THE LIGHT WINDS AND
MOIST BOUNDARY LAYER IS RESULTING IN NUMEROUS PLACES WITH VISIBILITY
BELOW A QUARTER OF A MILE. THE FOG SHOULD START TO BREAK UP BY 8 AM.
ALSO FINE TUNED THE T AND TD GRIDS PER THE LATEST OBS AND TRENDS. THE
GRIDS...AN SPS...UPDATED ZONES...AND HWO HAVE BEEN ISSUED.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 325 AM EDT THU JUL 24 2014
06Z SFC ANALYSIS SHOWS A WEAK AREA OF LOW PRESSURE OVER EAST KENTUCKY
ALONG A COLD FRONT THAT IS GRADUALLY SETTLING THROUGH THE CWA. THIS
BOUNDARY AND LOW IS RESPONSIBLE FOR THE SHOWERS AND STORMS WE SAW
EARLIER IN THE EVENING AND THE ONES THAT STILL LINGER OVER NORTH
CENTRAL KENTUCKY. NORTHWEST OF THIS FRONT...A COOL AND DRY AREA OF
HIGH PRESSURE IS IN PLACE OVER THE MIDWEST ON FINAL APPROACH TO EAST
KENTUCKY...SCHEDULED TO ARRIVE BY THURSDAY EVENING. MEANWHILE...
SCATTERED SHOWERS AND STORMS WILL REMAIN A THREAT THROUGH THE REST OF
THE MORNING AND INTO THE START OF THURSDAY. PATCHY FOG AND PLENTY OF
LOW CLOUDS ARE FOUND THROUGH EAST KENTUCKY AT THE MOMENT...AS WELL.
THIS ALL IS EXPECTED TO LINGER THROUGH SUNRISE AS TEMPERATURES AND
DEWPOINTS STAY ABOUT WHERE THEY ARE CURRENTLY...IN THE UPPER 60S AND
LOWER 70S. SIMILARLY...THE WINDS WILL REMAIN LIGHT AND VARIABLE WELL
INTO THE DAY THURSDAY.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM AS THEY
ALL SHIFT THE EASTERN TROUGH SLIGHTLY NORTHEAST IN RESPONSE TO A
FLATTENING OF THE STRONG WESTERN RIDGE. LEADING OFF THIS TRANSITION
ARE A COUPLE OF SHORTWAVES THAT WILL CROSS THE SOUTHERN OHIO VALLEY
AND KENTUCKY INTO THE AFTERNOON THURSDAY. RISING HEIGHTS WILL FOLLOW
LATER TONIGHT AND THROUGH THE DAY FRIDAY HELPING TO KEEP ANY ENERGY
PACKETS IN THE NORTHWEST FLOW FROM AMOUNTING TO MUCH OVER OUR AREA.
WITH THE MODEL AGREEMENT HAVE FAVORED THE HRRR AND NAM12 SOLUTIONS
FOR THE FORECAST TODAY AND THEN A GENERAL MODEL BLEND INTO FRIDAY. OF
NOTE...BOTH THE NAM12 AND THE ECMWF DO MAKE MORE OUT OF A BAND OF
PCPN THAT THEY FORECAST TO ACCOMPANY THE COLD FRONT AS IT EXITS LATER
TODAY...IN COMPARISON TO THAN THE GFS AND GEM.
SENSIBLE WEATHER WILL FEATURE SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS SLOWLY EXITING EAST KENTUCKY AS A SFC WAVE AND COLD
FRONT DEPARTS TO THE SOUTHEAST BY LATE AFTERNOON. COOLER AIR WITH
THIS BOUNDARY...LOW CLOUDS...AND THE PCPN WILL KEEP TEMPERATURES ONLY
IN THE 70S TODAY. HIGH PRESSURE THEN SETTLES INTO THE AREA TONIGHT
WITH DRIER AIR AND EVEN COOLER TEMPERATURES. THE MAIN QUESTION FOR
TONIGHT WILL BE HOW MUCH CLOUD COVER WILL REMAIN OVER EAST KENTUCKY
IN THE WAKE OF THE FRONT. THE TIME SECTIONS FROM THE NAM12 SUGGEST
THAT LOW CLOUDS WILL BE TOUGH TO CLEAR THROUGH DAWN SO HAVE GONE
CLOUDIER WITH THE GRIDS...WITH LIMITED RADIATIONAL COOLING AND FOG
ANTICIPATED FOR THIS REASON. THESE CLOUDS SHOULD START TO BREAK UP
MORE EFFECTIVELY ON FRIDAY ALLOWING FOR A WARMUP BACK INTO THE LOW
80S...ALONG WITH PLEASANT HUMIDITY LEVELS.
HAVE USED THE CONSSHORT AS A STARTING POINT FOR TEMPERATURES...
DEWPOINTS...AND WINDS THROUGH THE FIRST 24 HOURS AND THEN THE CONSALL
THEREAFTER. AS FOR POPS...HAVE ENDED UP ON THE HIGH SIDE OF THE MOS
NUMBERS...CLOSER TO THE MET...TODAY WITH LOW POPS TONIGHT AND
FRIDAY...IN LINE WITH THE GUIDANCE.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 350 AM EDT THU JUL 24 2014
THE EXTENDED PORTION OF THE FORECAST BEGINS ON FRIDAY NIGHT WITH A
CONTINUED AND PRONOUNCED RIDGE OVER THE WEST AND DEEPENING TROUGH
OVER THE EASTERN CONUS. BOTH THE GFS AND EURO HINT AT A POSSIBLE
WEAKENING MCS TRAVERSING OVER THE RIDGE AND THROUGH THE UPPER MS
RIVER VALLEY AND INTO THE OH VALLEY ON FRIDAY NIGHT. FOLLOWING THIS
WILL BE A STRONG SHORT WAVE MOVING SOUTHEAST FROM MN AND INTO THE OH
VALLEY BY SUNDAY AND SUNDAY NIGHT. AS THIS WAVE SWINGS THROUGH THE
BASE OF THE TROUGH...A 90 KNOT JET MAX WILL PUSH THROUGH DEEPENING
THE LONG WAVE TROUGH OVER THE EASTERN CONUS AND KEEPING THE QUITE
AMPLIFIED TROUGH IN PLACE THROUGH THE REST OF THE EXTENDED. IN
RESPONSE...THE WESTERN RIDGE INCREASES IN STRENGTH KEEPING A RARE
MERIDIONAL PATTERN IN PLACE FOR THIS TIME OF YEAR. WITH THE MODELS
SHOWING SOME AGREEMENT IN THIS TREND IT CAN BE SAFE TO SHOW A HIGH
LEVEL OF CONFIDENCE WITH THE ALL MODEL BLEND SOLUTION.
FOR SOME MORE DETAILS IN THE LOWER LEVELS...THE MODELS SEEM TO BE IN
AGREEMENT WITH THE DECAYING MCS MAKING IT INTO THE AREA FRIDAY
NIGHT. THIS SHOULD ERODE THE ADVERTISED CAP THROUGH FRIDAY NIGHT AND
ALLOW SOME ADDITIONAL DEVELOPMENT INTO THE DAY ON SATURDAY WITH
DECENT INSTABILITY AVAILABLE AND SOME UPPER LEVEL SUPPORT ARRIVING
AHEAD OF A POTENT SHORTWAVE. THE BEST CHANCE FOR SHOWER AND
THUNDERSTORM DEVELOPMENT WILL COME ON SUNDAY AND INTO MONDAY WITH A
STRONG COLD FRONT MOVING THROUGH. WENT WITH THE LIKELY POPS
INHERITED FROM THE ALL MODEL BLEND. AT AN EARLY LOOK TO THIS
SCENARIO...QUITE A BIT OF DYNAMICS ARE WITH THIS FEATURE WITH THE
STRONG JET STREAK MOVING THROUGH THE OH VALLEY AND AFTERNOON CAPE
VALUES REACHING 2500 J/KG...A SEVERE WEATHER THREAT IS CERTAINLY NOT
OUT OF THE QUESTION IF THE STRENGTH OF THE WAVE HOLDS TRUE THROUGH
THE DAYS LEADING UP TO THE EVENT. THIS WILL BE THE REAL FORECAST
CHALLENGE AS THE POTENTIAL IS THERE...BUT WILL HAVE TO SEE HOW THE
MODELS TREND UP TO THE EVENT. A COUPLE WEAK DISTURBANCES WILL FOLLOW
BEHIND THIS WAVE AND WILL PROVIDE A LOW CHANCE FOR PRECIP INTO
TUESDAY BEFORE HIGH PRESSURE SETTLES IN FOR THE REST OF THE
EXTENDED. THE AIR MASS MOVING IN BEHIND THIS FRONT IS QUITE COOL
WITH HIGH TEMPERATURES FOR MONDAY THROUGH WEDNESDAY IN THE MID
70S...AROUND 10 DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. MODEL
TRENDS WOULD SUGGEST THAT AN OVERALL COOLER PATTERN FOR THE LAST
WEEK OF JULY WILL BE THE CASE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 655 AM EDT THU JUL 24 2014
SCATTERED SHOWERS AND THE OCCASIONAL THUNDERSTORM WILL CONTINUE TO
SLOWLY DRIFT SOUTHEAST THROUGH THE MORNING. AREAS OF DENSE FOG ARE
AFFECTING MANY OF THE AIRPORTS THIS MORNING IN LIEU OF THE
CONVECTION. EXPECT VIS AND CIG CONDITIONS TO GRADUALLY IMPROVE
FOLLOWING SUNRISE. HAVE KEPT THUNDER AND EVEN VCTS OUT OF THE TAFS AS
THE INSTABILITY WILL BE FAIRLY LOW THROUGH THE DAY...THOUGH A STRAY
STORM CANNOT BE RULED OUT. THE LATEST HRRR AND NAM12 CONTINUE TO
INDICATE THAT THE CURRENT BAND OF CONVECTION ALONG THE FRONT WILL
HOLD TOGETHER AS IT MAKES ITS FINAL PUSH ACROSS THE AREA. HAVE
A VCSH FOR THIS IN ALL SITES WITH CIGS GENERALLY AROUND 2K FEET. IN
THE WAKE OF THE FRONT LATER THIS EVENING...DRIER AIR IS EXPECTED TO
LIFT THE CIGS AND REMOVE THE THREAT OF SHOWERS. WINDS THROUGH THE
PERIOD WILL BE MAINLY LIGHT AND VARIABLE...THOUGH FAVORING THE
NORTHERLY DIRECTION LATER TODAY AND INTO THE EVENING. PATCHY FOG WILL
BE A CONCERN LATER TONIGHT AS WELL...BUT GENERALLY ONLY IF WE MANAGE
TO CLEAR OUT. FOR NOW WILL LEAVE THIS OUT OF THE TAFS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...ABE
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
655 AM EDT THU JUL 24 2014
.UPDATE...
ISSUED AT 540 AM EDT THU JUL 24 2014
UPDATED THE FORECAST TO ADD AREAS OF DENSE FOG INTO THE GRIDS FOR
THIS MORNING GIVEN THE OBSERVATIONS AND WEB CAMS. THE LIGHT WINDS AND
MOIST BOUNDARY LAYER IS RESULTING IN NUMEROUS PLACES WITH VISIBILITY
BELOW A QUARTER OF A MILE. THE FOG SHOULD START TO BREAK UP BY 8 AM.
ALSO FINE TUNED THE T AND TD GRIDS PER THE LATEST OBS AND TRENDS. THE
GRIDS...AN SPS...UPDATED ZONES...AND HWO HAVE BEEN ISSUED.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 325 AM EDT THU JUL 24 2014
06Z SFC ANALYSIS SHOWS A WEAK AREA OF LOW PRESSURE OVER EAST KENTUCKY
ALONG A COLD FRONT THAT IS GRADUALLY SETTLING THROUGH THE CWA. THIS
BOUNDARY AND LOW IS RESPONSIBLE FOR THE SHOWERS AND STORMS WE SAW
EARLIER IN THE EVENING AND THE ONES THAT STILL LINGER OVER NORTH
CENTRAL KENTUCKY. NORTHWEST OF THIS FRONT...A COOL AND DRY AREA OF
HIGH PRESSURE IS IN PLACE OVER THE MIDWEST ON FINAL APPROACH TO EAST
KENTUCKY...SCHEDULED TO ARRIVE BY THURSDAY EVENING. MEANWHILE...
SCATTERED SHOWERS AND STORMS WILL REMAIN A THREAT THROUGH THE REST OF
THE MORNING AND INTO THE START OF THURSDAY. PATCHY FOG AND PLENTY OF
LOW CLOUDS ARE FOUND THROUGH EAST KENTUCKY AT THE MOMENT...AS WELL.
THIS ALL IS EXPECTED TO LINGER THROUGH SUNRISE AS TEMPERATURES AND
DEWPOINTS STAY ABOUT WHERE THEY ARE CURRENTLY...IN THE UPPER 60S AND
LOWER 70S. SIMILARLY...THE WINDS WILL REMAIN LIGHT AND VARIABLE WELL
INTO THE DAY THURSDAY.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM AS THEY
ALL SHIFT THE EASTERN TROUGH SLIGHTLY NORTHEAST IN RESPONSE TO A
FLATTENING OF THE STRONG WESTERN RIDGE. LEADING OFF THIS TRANSITION
ARE A COUPLE OF SHORTWAVES THAT WILL CROSS THE SOUTHERN OHIO VALLEY
AND KENTUCKY INTO THE AFTERNOON THURSDAY. RISING HEIGHTS WILL FOLLOW
LATER TONIGHT AND THROUGH THE DAY FRIDAY HELPING TO KEEP ANY ENERGY
PACKETS IN THE NORTHWEST FLOW FROM AMOUNTING TO MUCH OVER OUR AREA.
WITH THE MODEL AGREEMENT HAVE FAVORED THE HRRR AND NAM12 SOLUTIONS
FOR THE FORECAST TODAY AND THEN A GENERAL MODEL BLEND INTO FRIDAY. OF
NOTE...BOTH THE NAM12 AND THE ECMWF DO MAKE MORE OUT OF A BAND OF
PCPN THAT THEY FORECAST TO ACCOMPANY THE COLD FRONT AS IT EXITS LATER
TODAY...IN COMPARISON TO THAN THE GFS AND GEM.
SENSIBLE WEATHER WILL FEATURE SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS SLOWLY EXITING EAST KENTUCKY AS A SFC WAVE AND COLD
FRONT DEPARTS TO THE SOUTHEAST BY LATE AFTERNOON. COOLER AIR WITH
THIS BOUNDARY...LOW CLOUDS...AND THE PCPN WILL KEEP TEMPERATURES ONLY
IN THE 70S TODAY. HIGH PRESSURE THEN SETTLES INTO THE AREA TONIGHT
WITH DRIER AIR AND EVEN COOLER TEMPERATURES. THE MAIN QUESTION FOR
TONIGHT WILL BE HOW MUCH CLOUD COVER WILL REMAIN OVER EAST KENTUCKY
IN THE WAKE OF THE FRONT. THE TIME SECTIONS FROM THE NAM12 SUGGEST
THAT LOW CLOUDS WILL BE TOUGH TO CLEAR THROUGH DAWN SO HAVE GONE
CLOUDIER WITH THE GRIDS...WITH LIMITED RADIATIONAL COOLING AND FOG
ANTICIPATED FOR THIS REASON. THESE CLOUDS SHOULD START TO BREAK UP
MORE EFFECTIVELY ON FRIDAY ALLOWING FOR A WARMUP BACK INTO THE LOW
80S...ALONG WITH PLEASANT HUMIDITY LEVELS.
HAVE USED THE CONSSHORT AS A STARTING POINT FOR TEMPERATURES...
DEWPOINTS...AND WINDS THROUGH THE FIRST 24 HOURS AND THEN THE CONSALL
THEREAFTER. AS FOR POPS...HAVE ENDED UP ON THE HIGH SIDE OF THE MOS
NUMBERS...CLOSER TO THE MET...TODAY WITH LOW POPS TONIGHT AND
FRIDAY...IN LINE WITH THE GUIDANCE.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 350 AM EDT THU JUL 24 2014
THE EXTENDED PORTION OF THE FORECAST BEGINS ON FRIDAY NIGHT WITH A
CONTINUED AND PRONOUNCED RIDGE OVER THE WEST AND DEEPENING TROUGH
OVER THE EASTERN CONUS. BOTH THE GFS AND EURO HINT AT A POSSIBLE
WEAKENING MCS TRAVERSING OVER THE RIDGE AND THROUGH THE UPPER MS
RIVER VALLEY AND INTO THE OH VALLEY ON FRIDAY NIGHT. FOLLOWING THIS
WILL BE A STRONG SHORT WAVE MOVING SOUTHEAST FROM MN AND INTO THE OH
VALLEY BY SUNDAY AND SUNDAY NIGHT. AS THIS WAVE SWINGS THROUGH THE
BASE OF THE TROUGH...A 90 KNOT JET MAX WILL PUSH THROUGH DEEPENING
THE LONG WAVE TROUGH OVER THE EASTERN CONUS AND KEEPING THE QUITE
AMPLIFIED TROUGH IN PLACE THROUGH THE REST OF THE EXTENDED. IN
RESPONSE...THE WESTERN RIDGE INCREASES IN STRENGTH KEEPING A RARE
MERIDIONAL PATTERN IN PLACE FOR THIS TIME OF YEAR. WITH THE MODELS
SHOWING SOME AGREEMENT IN THIS TREND IT CAN BE SAFE TO SHOW A HIGH
LEVEL OF CONFIDENCE WITH THE ALL MODEL BLEND SOLUTION.
FOR SOME MORE DETAILS IN THE LOWER LEVELS...THE MODELS SEEM TO BE IN
AGREEMENT WITH THE DECAYING MCS MAKING IT INTO THE AREA FRIDAY
NIGHT. THIS SHOULD ERODE THE ADVERTISED CAP THROUGH FRIDAY NIGHT AND
ALLOW SOME ADDITIONAL DEVELOPMENT INTO THE DAY ON SATURDAY WITH
DECENT INSTABILITY AVAILABLE AND SOME UPPER LEVEL SUPPORT ARRIVING
AHEAD OF A POTENT SHORTWAVE. THE BEST CHANCE FOR SHOWER AND
THUNDERSTORM DEVELOPMENT WILL COME ON SUNDAY AND INTO MONDAY WITH A
STRONG COLD FRONT MOVING THROUGH. WENT WITH THE LIKELY POPS
INHERITED FROM THE ALL MODEL BLEND. AT AN EARLY LOOK TO THIS
SCENARIO...QUITE A BIT OF DYNAMICS ARE WITH THIS FEATURE WITH THE
STRONG JET STREAK MOVING THROUGH THE OH VALLEY AND AFTERNOON CAPE
VALUES REACHING 2500 J/KG...A SEVERE WEATHER THREAT IS CERTAINLY NOT
OUT OF THE QUESTION IF THE STRENGTH OF THE WAVE HOLDS TRUE THROUGH
THE DAYS LEADING UP TO THE EVENT. THIS WILL BE THE REAL FORECAST
CHALLENGE AS THE POTENTIAL IS THERE...BUT WILL HAVE TO SEE HOW THE
MODELS TREND UP TO THE EVENT. A COUPLE WEAK DISTURBANCES WILL FOLLOW
BEHIND THIS WAVE AND WILL PROVIDE A LOW CHANCE FOR PRECIP INTO
TUESDAY BEFORE HIGH PRESSURE SETTLES IN FOR THE REST OF THE
EXTENDED. THE AIR MASS MOVING IN BEHIND THIS FRONT IS QUITE COOL
WITH HIGH TEMPERATURES FOR MONDAY THROUGH WEDNESDAY IN THE MID
70S...AROUND 10 DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. MODEL
TRENDS WOULD SUGGEST THAT AN OVERALL COOLER PATTERN FOR THE LAST
WEEK OF JULY WILL BE THE CASE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 655 AM EDT THU JUL 24 2014
SCATTERED SHOWERS AND THE OCCASIONAL THUNDERSTORM WILL CONTINUE TO
SLOWLY DRIFT SOUTHEAST THROUGH THE MORNING. AREAS OF DENSE FOG ARE
AFFECTING MANY OF THE AIRPORTS THIS MORNING IN LIEU OF THE
CONVECTION. EXPECT VIS AND CIG CONDITIONS TO GRADUALLY IMPROVE
FOLLOWING SUNRISE. HAVE KEPT THUNDER AND EVEN VCTS OUT OF THE TAFS AS
THE INSTABILITY WILL BE FAIRLY LOW THROUGH THE DAY...THOUGH A STRAY
STORM CANNOT BE RULED OUT. THE LATEST HRRR AND NAM12 CONTINUE TO
INDICATE THAT THE CURRENT BAND OF CONVECTION ALONG THE FRONT WILL
HOLD TOGETHER AS IT MAKES ITS FINAL PUSH ACROSS THE AREA. HAVE
A VCSH FOR THIS IN ALL SITES WITH CIGS GENERALLY AROUND 2K FEET. IN
THE WAKE OF THE FRONT LATER THIS EVENING...DRIER AIR IS EXPECTED TO
LIFT THE CIGS AND REMOVE THE THREAT OF SHOWERS. WINDS THROUGH THE
PERIOD WILL BE MAINLY LIGHT AND VARIABLE...THOUGH FAVORING THE
NORTHERLY DIRECTION LATER TODAY AND INTO THE EVENING. PATCHY FOG WILL
BE A CONCERN LATER TONIGHT AS WELL...BUT GENERALLY ONLY IF WE MANAGE
TO CLEAR OUT. FOR NOW WILL LEAVE THIS OUT OF THE TAFS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
540 AM EDT THU JUL 24 2014
.UPDATE...
ISSUED AT 540 AM EDT THU JUL 24 2014
UPDATED THE FORECAST TO ADD AREAS OF DENSE FOG INTO THE GRIDS FOR
THIS MORNING GIVEN THE OBSERVATIONS AND WEB CAMS. THE LIGHT WINDS AND
MOIST BOUNDARY LAYER IS RESULTING IN NUMEROUS PLACES WITH VISIBILITY
BELOW A QUARTER OF A MILE. THE FOG SHOULD START TO BREAK UP BY 8 AM.
ALSO FINE TUNED THE T AND TD GRIDS PER THE LATEST OBS AND TRENDS. THE
GRIDS...AN SPS...UPDATED ZONES...AND HWO HAVE BEEN ISSUED.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 325 AM EDT THU JUL 24 2014
06Z SFC ANALYSIS SHOWS A WEAK AREA OF LOW PRESSURE OVER EAST KENTUCKY
ALONG A COLD FRONT THAT IS GRADUALLY SETTLING THROUGH THE CWA. THIS
BOUNDARY AND LOW IS RESPONSIBLE FOR THE SHOWERS AND STORMS WE SAW
EARLIER IN THE EVENING AND THE ONES THAT STILL LINGER OVER NORTH
CENTRAL KENTUCKY. NORTHWEST OF THIS FRONT...A COOL AND DRY AREA OF
HIGH PRESSURE IS IN PLACE OVER THE MIDWEST ON FINAL APPROACH TO EAST
KENTUCKY...SCHEDULED TO ARRIVE BY THURSDAY EVENING. MEANWHILE...
SCATTERED SHOWERS AND STORMS WILL REMAIN A THREAT THROUGH THE REST OF
THE MORNING AND INTO THE START OF THURSDAY. PATCHY FOG AND PLENTY OF
LOW CLOUDS ARE FOUND THROUGH EAST KENTUCKY AT THE MOMENT...AS WELL.
THIS ALL IS EXPECTED TO LINGER THROUGH SUNRISE AS TEMPERATURES AND
DEWPOINTS STAY ABOUT WHERE THEY ARE CURRENTLY...IN THE UPPER 60S AND
LOWER 70S. SIMILARLY...THE WINDS WILL REMAIN LIGHT AND VARIABLE WELL
INTO THE DAY THURSDAY.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM AS THEY
ALL SHIFT THE EASTERN TROUGH SLIGHTLY NORTHEAST IN RESPONSE TO A
FLATTENING OF THE STRONG WESTERN RIDGE. LEADING OFF THIS TRANSITION
ARE A COUPLE OF SHORTWAVES THAT WILL CROSS THE SOUTHERN OHIO VALLEY
AND KENTUCKY INTO THE AFTERNOON THURSDAY. RISING HEIGHTS WILL FOLLOW
LATER TONIGHT AND THROUGH THE DAY FRIDAY HELPING TO KEEP ANY ENERGY
PACKETS IN THE NORTHWEST FLOW FROM AMOUNTING TO MUCH OVER OUR AREA.
WITH THE MODEL AGREEMENT HAVE FAVORED THE HRRR AND NAM12 SOLUTIONS
FOR THE FORECAST TODAY AND THEN A GENERAL MODEL BLEND INTO FRIDAY. OF
NOTE...BOTH THE NAM12 AND THE ECMWF DO MAKE MORE OUT OF A BAND OF
PCPN THAT THEY FORECAST TO ACCOMPANY THE COLD FRONT AS IT EXITS LATER
TODAY...IN COMPARISON TO THAN THE GFS AND GEM.
SENSIBLE WEATHER WILL FEATURE SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS SLOWLY EXITING EAST KENTUCKY AS A SFC WAVE AND COLD
FRONT DEPARTS TO THE SOUTHEAST BY LATE AFTERNOON. COOLER AIR WITH
THIS BOUNDARY...LOW CLOUDS...AND THE PCPN WILL KEEP TEMPERATURES ONLY
IN THE 70S TODAY. HIGH PRESSURE THEN SETTLES INTO THE AREA TONIGHT
WITH DRIER AIR AND EVEN COOLER TEMPERATURES. THE MAIN QUESTION FOR
TONIGHT WILL BE HOW MUCH CLOUD COVER WILL REMAIN OVER EAST KENTUCKY
IN THE WAKE OF THE FRONT. THE TIME SECTIONS FROM THE NAM12 SUGGEST
THAT LOW CLOUDS WILL BE TOUGH TO CLEAR THROUGH DAWN SO HAVE GONE
CLOUDIER WITH THE GRIDS...WITH LIMITED RADIATIONAL COOLING AND FOG
ANTICIPATED FOR THIS REASON. THESE CLOUDS SHOULD START TO BREAK UP
MORE EFFECTIVELY ON FRIDAY ALLOWING FOR A WARMUP BACK INTO THE LOW
80S...ALONG WITH PLEASANT HUMIDITY LEVELS.
HAVE USED THE CONSSHORT AS A STARTING POINT FOR TEMPERATURES...
DEWPOINTS...AND WINDS THROUGH THE FIRST 24 HOURS AND THEN THE CONSALL
THEREAFTER. AS FOR POPS...HAVE ENDED UP ON THE HIGH SIDE OF THE MOS
NUMBERS...CLOSER TO THE MET...TODAY WITH LOW POPS TONIGHT AND
FRIDAY...IN LINE WITH THE GUIDANCE.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 350 AM EDT THU JUL 24 2014
THE EXTENDED PORTION OF THE FORECAST BEGINS ON FRIDAY NIGHT WITH A
CONTINUED AND PRONOUNCED RIDGE OVER THE WEST AND DEEPENING TROUGH
OVER THE EASTERN CONUS. BOTH THE GFS AND EURO HINT AT A POSSIBLE
WEAKENING MCS TRAVERSING OVER THE RIDGE AND THROUGH THE UPPER MS
RIVER VALLEY AND INTO THE OH VALLEY ON FRIDAY NIGHT. FOLLOWING THIS
WILL BE A STRONG SHORT WAVE MOVING SOUTHEAST FROM MN AND INTO THE OH
VALLEY BY SUNDAY AND SUNDAY NIGHT. AS THIS WAVE SWINGS THROUGH THE
BASE OF THE TROUGH...A 90 KNOT JET MAX WILL PUSH THROUGH DEEPENING
THE LONG WAVE TROUGH OVER THE EASTERN CONUS AND KEEPING THE QUITE
AMPLIFIED TROUGH IN PLACE THROUGH THE REST OF THE EXTENDED. IN
RESPONSE...THE WESTERN RIDGE INCREASES IN STRENGTH KEEPING A RARE
MERIDIONAL PATTERN IN PLACE FOR THIS TIME OF YEAR. WITH THE MODELS
SHOWING SOME AGREEMENT IN THIS TREND IT CAN BE SAFE TO SHOW A HIGH
LEVEL OF CONFIDENCE WITH THE ALL MODEL BLEND SOLUTION.
FOR SOME MORE DETAILS IN THE LOWER LEVELS...THE MODELS SEEM TO BE IN
AGREEMENT WITH THE DECAYING MCS MAKING IT INTO THE AREA FRIDAY
NIGHT. THIS SHOULD ERODE THE ADVERTISED CAP THROUGH FRIDAY NIGHT AND
ALLOW SOME ADDITIONAL DEVELOPMENT INTO THE DAY ON SATURDAY WITH
DECENT INSTABILITY AVAILABLE AND SOME UPPER LEVEL SUPPORT ARRIVING
AHEAD OF A POTENT SHORTWAVE. THE BEST CHANCE FOR SHOWER AND
THUNDERSTORM DEVELOPMENT WILL COME ON SUNDAY AND INTO MONDAY WITH A
STRONG COLD FRONT MOVING THROUGH. WENT WITH THE LIKELY POPS
INHERITED FROM THE ALL MODEL BLEND. AT AN EARLY LOOK TO THIS
SCENARIO...QUITE A BIT OF DYNAMICS ARE WITH THIS FEATURE WITH THE
STRONG JET STREAK MOVING THROUGH THE OH VALLEY AND AFTERNOON CAPE
VALUES REACHING 2500 J/KG...A SEVERE WEATHER THREAT IS CERTAINLY NOT
OUT OF THE QUESTION IF THE STRENGTH OF THE WAVE HOLDS TRUE THROUGH
THE DAYS LEADING UP TO THE EVENT. THIS WILL BE THE REAL FORECAST
CHALLENGE AS THE POTENTIAL IS THERE...BUT WILL HAVE TO SEE HOW THE
MODELS TREND UP TO THE EVENT. A COUPLE WEAK DISTURBANCES WILL FOLLOW
BEHIND THIS WAVE AND WILL PROVIDE A LOW CHANCE FOR PRECIP INTO
TUESDAY BEFORE HIGH PRESSURE SETTLES IN FOR THE REST OF THE
EXTENDED. THE AIR MASS MOVING IN BEHIND THIS FRONT IS QUITE COOL
WITH HIGH TEMPERATURES FOR MONDAY THROUGH WEDNESDAY IN THE MID
70S...AROUND 10 DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. MODEL
TRENDS WOULD SUGGEST THAT AN OVERALL COOLER PATTERN FOR THE LAST
WEEK OF JULY WILL BE THE CASE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 155 AM EDT THU JUL 24 2014
SCATTERED SHOWERS AND THE ODD THUNDERSTORM WILL CONTINUE TO DIMINISH
FOR THE BULK OF THE FORECAST AREA THROUGH THE NIGHT. HOWEVER...A
COUPLE OF CELLS WILL STILL BE POSSIBLE INTO DAWN...BUT PROBABLY KEEP
FROM HITTING ANY OF THE ACTUAL TAF SITES. FOR THE MOST PART...
CONDITIONS WILL BE MVFR AT ALL THE AIRPORTS TONIGHT WITH TIMES OF VFR
BUT ALSO LOW VIS/CIG INDUCED IFR WX...OR LOWER. HAVE KEPT THUNDER AND
EVEN VCTS OUT OF THE TAFS AS THE INSTABILITY WILL BE MINIMAL
THROUGH THE REST OF THE NIGHT INTO THURSDAY. HOWEVER...THE LATEST
HRRR AND NAM12 SUGGEST THAT A FEW SHOWERS WILL STILL BE POSSIBLE INTO
THE AFTERNOON AS THE FRONT MAKES ITS FINAL PUSH ACROSS THE AREA.
HAVE CONTINUED A VCSH FOR THIS IN ALL SITES WITH CIGS GENERALLY AROUND
2K FEET. IN THE WAKE OF THE FRONT LATER THURSDAY EVENING...DRIER AIR
IS EXPECTED TO LIFT THE CIGS AND REMOVE THE THREAT OF SHOWERS. WINDS
THROUGH THE PERIOD WILL BE MAINLY LIGHT AND VARIABLE...THOUGH
FAVORING THE NORTHERLY DIRECTION LATER THURSDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
350 AM EDT THU JUL 24 2014
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 325 AM EDT THU JUL 24 2014
06Z SFC ANALYSIS SHOWS A WEAK AREA OF LOW PRESSURE OVER EAST KENTUCKY
ALONG A COLD FRONT THAT IS GRADUALLY SETTLING THROUGH THE CWA. THIS
BOUNDARY AND LOW IS RESPONSIBLE FOR THE SHOWERS AND STORMS WE SAW
EARLIER IN THE EVENING AND THE ONES THAT STILL LINGER OVER NORTH
CENTRAL KENTUCKY. NORTHWEST OF THIS FRONT...A COOL AND DRY AREA OF
HIGH PRESSURE IS IN PLACE OVER THE MIDWEST ON FINAL APPROACH TO EAST
KENTUCKY...SCHEDULED TO ARRIVE BY THURSDAY EVENING. MEANWHILE...
SCATTERED SHOWERS AND STORMS WILL REMAIN A THREAT THROUGH THE REST OF
THE MORNING AND INTO THE START OF THURSDAY. PATCHY FOG AND PLENTY OF
LOW CLOUDS ARE FOUND THROUGH EAST KENTUCKY AT THE MOMENT...AS WELL.
THIS ALL IS EXPECTED TO LINGER THROUGH SUNRISE AS TEMPERATURES AND
DEWPOINTS STAY ABOUT WHERE THEY ARE CURRENTLY...IN THE UPPER 60S AND
LOWER 70S. SIMILARLY...THE WINDS WILL REMAIN LIGHT AND VARIABLE WELL
INTO THE DAY THURSDAY.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM AS THEY
ALL SHIFT THE EASTERN TROUGH SLIGHTLY NORTHEAST IN RESPONSE TO A
FLATTENING OF THE STRONG WESTERN RIDGE. LEADING OFF THIS TRANSITION
ARE A COUPLE OF SHORTWAVES THAT WILL CROSS THE SOUTHERN OHIO VALLEY
AND KENTUCKY INTO THE AFTERNOON THURSDAY. RISING HEIGHTS WILL FOLLOW
LATER TONIGHT AND THROUGH THE DAY FRIDAY HELPING TO KEEP ANY ENERGY
PACKETS IN THE NORTHWEST FLOW FROM AMOUNTING TO MUCH OVER OUR AREA.
WITH THE MODEL AGREEMENT HAVE FAVORED THE HRRR AND NAM12 SOLUTIONS
FOR THE FORECAST TODAY AND THEN A GENERAL MODEL BLEND INTO FRIDAY. OF
NOTE...BOTH THE NAM12 AND THE ECMWF DO MAKE MORE OUT OF A BAND OF
PCPN THAT THEY FORECAST TO ACCOMPANY THE COLD FRONT AS IT EXITS LATER
TODAY...IN COMPARISON TO THAN THE GFS AND GEM.
SENSIBLE WEATHER WILL FEATURE SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS SLOWLY EXITING EAST KENTUCKY AS A SFC WAVE AND COLD
FRONT DEPARTS TO THE SOUTHEAST BY LATE AFTERNOON. COOLER AIR WITH
THIS BOUNDARY...LOW CLOUDS...AND THE PCPN WILL KEEP TEMPERATURES ONLY
IN THE 70S TODAY. HIGH PRESSURE THEN SETTLES INTO THE AREA TONIGHT
WITH DRIER AIR AND EVEN COOLER TEMPERATURES. THE MAIN QUESTION FOR
TONIGHT WILL BE HOW MUCH CLOUD COVER WILL REMAIN OVER EAST KENTUCKY
IN THE WAKE OF THE FRONT. THE TIME SECTIONS FROM THE NAM12 SUGGEST
THAT LOW CLOUDS WILL BE TOUGH TO CLEAR THROUGH DAWN SO HAVE GONE
CLOUDIER WITH THE GRIDS...WITH LIMITED RADIATIONAL COOLING AND FOG
ANTICIPATED FOR THIS REASON. THESE CLOUDS SHOULD START TO BREAK UP
MORE EFFECTIVELY ON FRIDAY ALLOWING FOR A WARMUP BACK INTO THE LOW
80S...ALONG WITH PLEASANT HUMIDITY LEVELS.
HAVE USED THE CONSSHORT AS A STARTING POINT FOR TEMPERATURES...
DEWPOINTS...AND WINDS THROUGH THE FIRST 24 HOURS AND THEN THE CONSALL
THEREAFTER. AS FOR POPS...HAVE ENDED UP ON THE HIGH SIDE OF THE MOS
NUMBERS...CLOSER TO THE MET...TODAY WITH LOW POPS TONIGHT AND
FRIDAY...IN LINE WITH THE GUIDANCE.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 350 AM EDT THU JUL 24 2014
THE EXTENDED PORTION OF THE FORECAST BEGINS ON FRIDAY NIGHT WITH A
CONTINUED AND PRONOUNCED RIDGE OVER THE WEST AND DEEPENING TROUGH
OVER THE EASTERN CONUS. BOTH THE GFS AND EURO HINT AT A POSSIBLE
WEAKENING MCS TRAVERSING OVER THE RIDGE AND THROUGH THE UPPER MS
RIVER VALLEY AND INTO THE OH VALLEY ON FRIDAY NIGHT. FOLLOWING THIS
WILL BE A STRONG SHORT WAVE MOVING SOUTHEAST FROM MN AND INTO THE OH
VALLEY BY SUNDAY AND SUNDAY NIGHT. AS THIS WAVE SWINGS THROUGH THE
BASE OF THE TROUGH...A 90 KNOT JET MAX WILL PUSH THROUGH DEEPENING
THE LONG WAVE TROUGH OVER THE EASTERN CONUS AND KEEPING THE QUITE
AMPLIFIED TROUGH IN PLACE THROUGH THE REST OF THE EXTENDED. IN
RESPONSE...THE WESTERN RIDGE INCREASES IN STRENGTH KEEPING A RARE
MERIDIONAL PATTERN IN PLACE FOR THIS TIME OF YEAR. WITH THE MODELS
SHOWING SOME AGREEMENT IN THIS TREND IT CAN BE SAFE TO SHOW A HIGH
LEVEL OF CONFIDENCE WITH THE ALL MODEL BLEND SOLUTION.
FOR SOME MORE DETAILS IN THE LOWER LEVELS...THE MODELS SEEM TO BE IN
AGREEMENT WITH THE DECAYING MCS MAKING IT INTO THE AREA FRIDAY
NIGHT. THIS SHOULD ERODE THE ADVERTISED CAP THROUGH FRIDAY NIGHT AND
ALLOW SOME ADDITIONAL DEVELOPMENT INTO THE DAY ON SATURDAY WITH
DECENT INSTABILITY AVAILABLE AND SOME UPPER LEVEL SUPPORT ARRIVING
AHEAD OF A POTENT SHORTWAVE. THE BEST CHANCE FOR SHOWER AND
THUNDERSTORM DEVELOPMENT WILL COME ON SUNDAY AND INTO MONDAY WITH A
STRONG COLD FRONT MOVING THROUGH. WENT WITH THE LIKELY POPS
INHERITED FROM THE ALL MODEL BLEND. AT AN EARLY LOOK TO THIS
SCENARIO...QUITE A BIT OF DYNAMICS ARE WITH THIS FEATURE WITH THE
STRONG JET STREAK MOVING THROUGH THE OH VALLEY AND AFTERNOON CAPE
VALUES REACHING 2500 J/KG...A SEVERE WEATHER THREAT IS CERTAINLY NOT
OUT OF THE QUESTION IF THE STRENGTH OF THE WAVE HOLDS TRUE THROUGH
THE DAYS LEADING UP TO THE EVENT. THIS WILL BE THE REAL FORECAST
CHALLENGE AS THE POTENTIAL IS THERE...BUT WILL HAVE TO SEE HOW THE
MODELS TREND UP TO THE EVENT. A COUPLE WEAK DISTURBANCES WILL FOLLOW
BEHIND THIS WAVE AND WILL PROVIDE A LOW CHANCE FOR PRECIP INTO
TUESDAY BEFORE HIGH PRESSURE SETTLES IN FOR THE REST OF THE
EXTENDED. THE AIR MASS MOVING IN BEHIND THIS FRONT IS QUITE COOL
WITH HIGH TEMPERATURES FOR MONDAY THROUGH WEDNESDAY IN THE MID
70S...AROUND 10 DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. MODEL
TRENDS WOULD SUGGEST THAT AN OVERALL COOLER PATTERN FOR THE LAST
WEEK OF JULY WILL BE THE CASE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 155 AM EDT THU JUL 24 2014
SCATTERED SHOWERS AND THE ODD THUNDERSTORM WILL CONTINUE TO DIMINISH
FOR THE BULK OF THE FORECAST AREA THROUGH THE NIGHT. HOWEVER...A
COUPLE OF CELLS WILL STILL BE POSSIBLE INTO DAWN...BUT PROBABLY KEEP
FROM HITTING ANY OF THE ACTUAL TAF SITES. FOR THE MOST PART...
CONDITIONS WILL BE MVFR AT ALL THE AIRPORTS TONIGHT WITH TIMES OF VFR
BUT ALSO LOW VIS/CIG INDUCED IFR WX...OR LOWER. HAVE KEPT THUNDER AND
EVEN VCTS OUT OF THE TAFS AS THE INSTABILITY WILL BE MINIMAL
THROUGH THE REST OF THE NIGHT INTO THURSDAY. HOWEVER...THE LATEST
HRRR AND NAM12 SUGGEST THAT A FEW SHOWERS WILL STILL BE POSSIBLE INTO
THE AFTERNOON AS THE FRONT MAKES ITS FINAL PUSH ACROSS THE AREA.
HAVE CONTINUED A VCSH FOR THIS IN ALL SITES WITH CIGS GENERALLY AROUND
2K FEET. IN THE WAKE OF THE FRONT LATER THURSDAY EVENING...DRIER AIR
IS EXPECTED TO LIFT THE CIGS AND REMOVE THE THREAT OF SHOWERS. WINDS
THROUGH THE PERIOD WILL BE MAINLY LIGHT AND VARIABLE...THOUGH
FAVORING THE NORTHERLY DIRECTION LATER THURSDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
242 PM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONT PUSHES ACROSS THE REGION LATER TODAY...THEN
DISSIPATES ACROSS THE CAROLINAS LATE TONIGHT THROUGH FRIDAY.
MEANWHILE, HIGH PRESSURE BUILDS NORTH OF THE AREA FRIDAY AND
SATURDAY. ANOTHER...STRONGER COLD FRONT WILL APPROACH THE AREA BY
EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
SUBSIDENCE BEHIND DEPARTING S/W ALLOWING CLOUDS TO THIN AND ADDNTL
HEATING TO OCCUR. MEANWHILE...SECOND ROUND OF CONVECTION DEVELOPING
ACROSS THE MTS TO THE NW WITH HRRR SUGGESTS THESE SAG SE ACROSS FA
LATER THIS AFTRN AND EVE. TMPS IN THE L-M80S.
PVS DSCN:
SURVEY TEAM AT THE EASTERN SHORE THIS AFTRN...
CLUSTER OF SUPERCELLS OUT AHEAD OF COLD FRONT CRNTLY MOVG OFFSHORE
WITH NUMEROUS SPECIAL MARINE WARNINGS IN EFFECT. STRONGEST STORM
FORMED OVER THE CHES BAY JUST AFTER 8 AM THEN INTENSIFIED AS IT
MOVED ONSHORE AT A CAMPGROUND IN NORTHAMPTON COUNTY ARND 830 AM.
SEVERAL REPORTS OF INJURIES WITH NUMEROUS REPORTS OF DAMAGE RECEIVED.
SEE LSRAKQ FOR LATEST DETAILS. UPDATE TO BE ISSUED ONCE SURVEY IS
COMPLETED.
PVS DSCN:
TONIGHT...
BOUNDARY LOOKS TO STALL ACROSS SERN VA/NRN NC TONIGHT INTO FRI
MORNING AS THE UPPER TROF LINGERS ACROSS THE CAROLINAS THROUGH FRI
AFTN. WHILE POPS ARE DROPPED ACROSS THE NORTH, LOW END CHC POPS
LINGER SOUTH OF THE NC BORDER. WEAK FLOW WILL BRING ONLY MODEST
INFLUX OF COOLER/DRIER AIRMASS ACROSS NORTHERN ZONES, WITH ANOTHER
MUGGY NIGHT FOR MOST. EARLY MORNING LOWS IN THE LOW TO MID 60S FAR
NORTHERN ZONES, 65 TO AROUND 70 SOUTH ELSEWHERE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
UPPER TROUGH AXIS PUSHES ACROSS FRIDAY INTO FRIDAY AFTN, WITH THE
SFC FRONT CLEARING THE CWA BY MIDDAY (STALLING JUST TO THE SOUTH
FRIDAY NIGHT). DRY FRI EXCEPT KEPT A SLIGHT CHC POP IN ACROSS NE NC
ZONES FRIDAY MORNING. THICKNESS TOOLS YIELD HIGHS IN THE L-M80S,
WHICH IS REFLECTED WELL BY THE GOING FORECAST.
WEAK CAA ACROSS THE NORTH AS HIGH PRESSURE BUILDS INTO THE AREA FROM
THE NORTH FRI NIGHT AND EARLY SATURDAY. GFS CONTINUES TO BRING
ACROSS SOME ISOLATED THUNDER BACK IN SAT AFTN AS LLVL SW FLOW
DEVELOPS AND PUSHES STALLED FRONT BACK NORTH. HOWEVER, WITH BEST
FORCING PASSING REGION WELL TO THE NORTH, AND WITH STRONG MIDLEVEL
CAP (INVERSION) EVIDENT ON FORECAST CROSS SECTIONS, THINKING IS THAT
OUR REGION WILL REMAIN DRY SATURDAY AND SAT NIGHT. HIGHS SAT 85-90.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
LONG TERM PERIOD STARTS OFF SAT NGT INTO SUN WITH AN UPR-LEVEL TROF
DIGGING OVR THE ERN CONUS AND SFC HI PRES PUSHING OFFSHORE. A
COMPLEX AREA OF SFC LO PRES WILL DEVELOP ACROSS THE GREAT LAKES
REGION...WITH A PREFRNTAL LEE TROF LEADING TO A CHANCE OF SHRAS/TSTMS
OVR THE LOCAL AREA. WITH DEEP S/SW FLOW...TEMPS WILL BE ABOUT FIVE
DEGREES ABOVE NORMAL...HIGHS IN THE LO TO MID 90S. THE
AFOREMENTIONED SFC LO WILL PUSH E AND DRAG A COLD FRNT INTO THE MID
ATLANTIC REGION MON/MON NGT. INCLUDED A 40% CHANCE OF SHRAS/TSTMS
DURING THIS TIME PERIOD. HIGHS MON IN THE UPR 80S TO LWR 90S. ASIDE
FM A LO CHANCE OF RAIN NEAR THE CST...CONDITIONS WILL DRY OUT FOR
TUE AND WED...WITH HIGHS ONLY IN THE MID 80S.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
STATIONARY BOUNDARY DRAPED ACROSS SE VA AND CONTINUING WESTWARD.
THIS BOUNDARY WILL BE THE FOCUS FOR REDEVELOPMENT OF SHOWERS AND
THUNDERSTORMS THIS AFTERNOON. COVERAGE OF PRECIP IS BEGINNING TO
INCREASE AND A BETTER PICTURE OF TIMING AND IMPACTS FROM PRECIP AT
THE TAF SITES WILL CONTINUE TO UNFOLD THIS AFTERNOON.
THE FRONTAL BOUNDARY SLOWLY PUSHES SE OVERNIGHT CONTINUING A
CHANCE FOR SHOWERS. CLEARING WILL TAKE PLACE ON FRIDAY WITH VFR
CONDITIONS EXPECTED THROUGH SATURDAY.
NOTE: OBSERVATIONS FROM KSBY ARE NOT READILY AVAILABLE DUE TO A
COMMUNICATIONS PROBLEM. RETURN TO SERVICE IS UNKNOWN AT THIS TIME.
HOWEVER...CURRENT INFORMATION MAY BE OBTAINED BY CALLING INTO THE
ASOS SITE DIRECTLY. AMD NOT SKED WILL BE APPENDED TO THE KSBY TAF
UNTIL FURTHER NOTICE.
&&
.MARINE...
AN APPROACHING COLD FRONT IS POSITIONED ALONG THE NEW ENGLAND
COAST TO SRN NJ AND THEN CUTS WWD ACROSS NRN VA AS OF 330 AM THIS
MORNING. THIS FRONT WILL SLOWLY CROSS THE WATERS TODAY AND
THUNDERSTORM CHANCES WILL INCREASE AS THE DAY PROGRESSES. MAIN
IMPACTS WILL BE LOCALIZED STRONG WIND GUSTS AND BRIEF HEAVY
RAINFALL. THE COLD FRONT STALLS ALONG THE NC COAST LATER THIS
EVENING INTO FRI MORNING...THEN PUSHES FARTHER TO THE SOUTHEAST
FOR THE REST OF THE WEEKEND. WSW TO WNW WINDS WILL PREVAIL THIS
MORNING...THEN BECOME NW-N THIS AFTN THROUGH FRI MORNING (AOB 15 KT).
WAVES GENERALLY 1-2 FT TODAY THROUGH FRIDAY...WHILE SEAS AVERAGE
1-3 FT DURING THE SAME TIME.
AN UPPER LEVEL TROUGH PUSHES ACROSS THE WATERS ON FRI AS SFC HIGH
PRESSURE BUILDS BACK INTO THE MID ATLANTIC REGION. WINDS N-NE AOB
10 KT FRI/FRI NIGHT. THE SFC HIGH THEN SLIDES OFF THE MID ATLANTIC
COAST BY SAT MORNING WITH WEAK CAA OCCURRING BEHIND ITS DEPARTURE.
THIS WILL MARK A RETURN TO ONSHORE E-SE WINDS AOB 15 KT THROUGH THE
REST OF THE WEEKEND. AN APPROACHING COLD FRONT ON SUNDAY WILL CAUSE
THE PRESSURE GRADIENT TO TIGHTEN AND A SLY SURGE IN WINDS IS
ANTICIPATED SAT NIGHT. THIS MAY PUSH SPEEDS INTO LOW-END SCA FOR
CHES BAY AND CURRITUCK SOUND (AOB 20 KT)...HOWEVER WAA PROCESSES MAY
PREVENT THIS FROM ACTUALLY HAPPENING. WILL MONITOR MODEL TRENDS OVER
THE NEXT FEW DAYS TO DETERMINE IF SCA HEADLINES ARE NECESSARY. THE
COLD FRONT IS EXPECTED TO CROSS THE WATERS LATE MON/MON NIGHT.
&&
.EQUIPMENT...
KDOX RADAR HAS RETURNED TO SERVICE BUT REMAINS UNSTABLE.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MPR/MAM
SHORT TERM...MAM
LONG TERM...MAS
AVIATION...DAP
MARINE...BMD
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
121 PM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONT PUSHES ACROSS THE REGION LATER TODAY...THEN
DISSIPATES ACROSS THE CAROLINAS LATE TONIGHT THROUGH FRIDAY.
MEANWHILE, HIGH PRESSURE BUILDS NORTH OF THE AREA FRIDAY AND
SATURDAY. ANOTHER...STRONGER COLD FRONT WILL APPROACH THE AREA BY
EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
SUBSIDENCE BEHIND DEPARTING S/W ALLOWING CLOUDS TO THIN AND ADDNTL
HEATING TO OCCUR. MEANWHILE...SECOND ROUND OF CONVECTION DEVELOPING
ACROSS THE MTS TO THE NW WITH HRRR SUGGESTS THESE SAG SE ACROSS FA
LATER THIS AFTRN AND EVE. TMPS IN THE L-M80S.
PVS DSCN:
...SURVEY TEAM AT THE EASTERN SHORE THIS AFTRN...
CLUSTER OF SUPERCELLS OUT AHEAD OF COLD FRONT CRNTLY MOVG OFFSHORE
WITH NUMEROUS SPECIAL MARINE WARNINGS IN EFFECT. STRONGEST STORM
FORMED OVER THE CHES BAY JUST AFTER 8 AM THEN INTENSIFIED AS IT
MOVED ONSHORE AT A CAMPGROUND IN NORTHAMPTON COUNTY ARND 830 AM.
SEVERAL REPORTS OF INJURIES WITH NUMEROUS REPORTS OF DAMAGE RECEIVED.
SEE LSRAKQ FOR LATEST DETAILS. UPDATE TO BE ISSUED ONCE SURVEY IS
COMPLETED.
PVS DSCN:
TONIGHT...
BOUNDARY LOOKS TO STALL ACROSS SERN VA/NRN NC TONIGHT INTO FRI
MORNING AS THE UPPER TROF LINGERS ACROSS THE CAROLINAS THROUGH FRI
AFTN. WHILE POPS ARE DROPPED ACROSS THE NORTH, LOW END CHC POPS
LINGER SOUTH OF THE NC BORDER. WEAK FLOW WILL BRING ONLY MODEST
INFLUX OF COOLER/DRIER AIRMASS ACROSS NORTHERN ZONES, WITH ANOTHER
MUGGY NIGHT FOR MOST. EARLY MORNING LOWS IN THE LOW TO MID 60S FAR
NORTHERN ZONES, 65 TO AROUND 70 SOUTH ELSEWHERE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
UPPER TROUGH AXIS PUSHES ACROSS FRIDAY INTO FRIDAY AFTN, WITH THE
SFC FRONT CLEARING THE CWA BY MIDDAY (STALLING JUST TO THE SOUTH
FRIDAY NIGHT). DRY FRI EXCEPT KEPT A SLIGHT CHC POP IN ACROSS NE NC
ZONES FRIDAY MORNING. THICKNESS TOOLS YIELD HIGHS IN THE L-M80S,
WHICH IS REFLECTED WELL BY THE GOING FORECAST.
WEAK CAA ACROSS THE NORTH AS HIGH PRESSURE BUILDS INTO THE AREA FROM
THE NORTH FRI NIGHT AND EARLY SATURDAY. GFS CONTINUES TO BRING
ACROSS SOME ISOLATED THUNDER BACK IN SAT AFTN AS LLVL SW FLOW
DEVELOPS AND PUSHES STALLED FRONT BACK NORTH. HOWEVER, WITH BEST
FORCING PASSING REGION WELL TO THE NORTH, AND WITH STRONG MIDLEVEL
CAP (INVERSION) EVIDENT ON FORECAST CROSS SECTIONS, THINKING IS THAT
OUR REGION WILL REMAIN DRY SATURDAY AND SAT NIGHT. HIGHS SAT 85-90.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
LONG TERM PERIOD STARTS OFF SAT NGT INTO SUN WITH AN UPR-LEVEL TROF
DIGGING OVR THE ERN CONUS AND SFC HI PRES PUSHING OFFSHORE. A
COMPLEX AREA OF SFC LO PRES WILL DEVELOP ACROSS THE GREAT LAKES
REGION...WITH A PREFRNTAL LEE TROF LEADING TO A CHANCE OF SHRAS/TSTMS
OVR THE LOCAL AREA. WITH DEEP S/SW FLOW...TEMPS WILL BE ABOUT FIVE
DEGREES ABOVE NORMAL...HIGHS IN THE LO TO MID 90S. THE
AFOREMENTIONED SFC LO WILL PUSH E AND DRAG A COLD FRNT INTO THE MID
ATLANTIC REGION MON/MON NGT. INCLUDED A 40% CHANCE OF SHRAS/TSTMS
DURING THIS TIME PERIOD. HIGHS MON IN THE UPR 80S TO LWR 90S. ASIDE
FM A LO CHANCE OF RAIN NEAR THE CST...CONDITIONS WILL DRY OUT FOR
TUE AND WED...WITH HIGHS ONLY IN THE MID 80S.
&&
.AVIATION /17Z THURSDAY THROUGH MONDAY/...
ISOLATED TO SCATTERED THUNDERSTORMS WILL LINGER OVER THE MD/VA
LOWER EASTERN SHORE IN THE VICINITY OF A THERMAL TROUGH THROUGH AT
LEAST 24/1000Z. AFTER WHICH...INCREASING CLOUD COVER AHEAD OF A
COLD FRONT NEAR THE WV/VA BORDER WILL OVERSPREAD THE ENTIRE AREA.
PATCHY FOG IS POSSIBLE FROM KSBY TO KLKU WITH CONDITIONS IMPROVING
AS THE NEXT BATCH OF RAIN MOVES EWD THIS MORNING...JUST AHEAD OF
THE FRONT. THUNDERSTORM DEVELOPMENT WILL BECOME FOCUSED ALONG THE
COLD FRONT AS THE DAY PROGRESSES...WITH BEST CHANCES EXPECTED TO
OCCUR SOUTHEAST OF KRIC. STORMS ARE NOT ANTICIPATED TO BECOME
SEVERE...HOWEVER LOCALLY STRONG WIND GUSTS AND BRIEF HEAVY
RAINFALL SHOULD BE THE MAIN IMPACTS TODAY. CONDITIONS DRY OUT FROM
NORTHWEST TO SOUTHEAST LATE THIS EVENING AND OVERNIGHT AS THE
FRONT STALLS ALONG THE NC COAST AFTER MIDNIGHT INTO FRIDAY
MORNING. LINGERING SHOWERS WILL BE POSSIBLE ACROSS FAR SE VA/NE NC
ON FRIDAY UNTIL THE FRONT PUSHES FARTHER TO THE SOUTHEAST AND HIGH
PRESSURE BUILDS INTO THE REGION FROM THE WNW. THE HIGH THEN SLIDES
OFF THE MID ATLANTIC COAST BY SATURDAY...BRINGING A RETURN TO
RAIN-FREE CONDITIONS DURING MOST OF THE WEEKEND. THE NEXT COLD
FRONT APPROACHES THE REGION ON SUNDAY. IT IS EXPECTED TO CROSS THE
REGION SUNDAY NIGHT AND THEN STALL NEAR THE MID ATLANTIC COAST
MON/TUE.
NOTE: OBSERVATIONS FROM KSBY ARE NOT READILY AVAILABLE DUE TO A
COMMUNICATIONS PROBLEM. RETURN TO SERVICE IS UNKNOWN AT THIS TIME.
HOWEVER...CURRENT INFORMATION MAY BE OBTAINED BY CALLING INTO THE
ASOS SITE DIRECTLY. AMD NOT SKED WILL BE APPENDED TO THE KSBY TAF
UNTIL FURTHER NOTICE.
&&
.MARINE...
AN APPROACHING COLD FRONT IS POSITIONED ALONG THE NEW ENGLAND
COAST TO SRN NJ AND THEN CUTS WWD ACROSS NRN VA AS OF 330 AM THIS
MORNING. THIS FRONT WILL SLOWLY CROSS THE WATERS TODAY AND
THUNDERSTORM CHANCES WILL INCREASE AS THE DAY PROGRESSES. MAIN
IMPACTS WILL BE LOCALIZED STRONG WIND GUSTS AND BRIEF HEAVY
RAINFALL. THE COLD FRONT STALLS ALONG THE NC COAST LATER THIS
EVENING INTO FRI MORNING...THEN PUSHES FARTHER TO THE SOUTHEAST
FOR THE REST OF THE WEEKEND. WSW TO WNW WINDS WILL PREVAIL THIS
MORNING...THEN BECOME NW-N THIS AFTN THROUGH FRI MORNING (AOB 15 KT).
WAVES GENERALLY 1-2 FT TODAY THROUGH FRIDAY...WHILE SEAS AVERAGE
1-3 FT DURING THE SAME TIME.
AN UPPER LEVEL TROUGH PUSHES ACROSS THE WATERS ON FRI AS SFC HIGH
PRESSURE BUILDS BACK INTO THE MID ATLANTIC REGION. WINDS N-NE AOB
10 KT FRI/FRI NIGHT. THE SFC HIGH THEN SLIDES OFF THE MID ATLANTIC
COAST BY SAT MORNING WITH WEAK CAA OCCURRING BEHIND ITS DEPARTURE.
THIS WILL MARK A RETURN TO ONSHORE E-SE WINDS AOB 15 KT THROUGH THE
REST OF THE WEEKEND. AN APPROACHING COLD FRONT ON SUNDAY WILL CAUSE
THE PRESSURE GRADIENT TO TIGHTEN AND A SLY SURGE IN WINDS IS
ANTICIPATED SAT NIGHT. THIS MAY PUSH SPEEDS INTO LOW-END SCA FOR
CHES BAY AND CURRITUCK SOUND (AOB 20 KT)...HOWEVER WAA PROCESSES MAY
PREVENT THIS FROM ACTUALLY HAPPENING. WILL MONITOR MODEL TRENDS OVER
THE NEXT FEW DAYS TO DETERMINE IF SCA HEADLINES ARE NECESSARY. THE
COLD FRONT IS EXPECTED TO CROSS THE WATERS LATE MON/MON NIGHT.
&&
.EQUIPMENT...
KDOX RADAR HAS RETURNED TO SERVICE BUT REMAINS UNSTABLE.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MPR/MAM
SHORT TERM...MAM
LONG TERM...MAS
AVIATION...BMD
MARINE...BMD
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1040 AM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONT PUSHES ACROSS THE REGION LATER TODAY...THEN
DISSIPATES ACROSS THE CAROLINAS LATE TONIGHT THROUGH FRIDAY.
MEANWHILE, HIGH PRESSURE BUILDS NORTH OF THE AREA FRIDAY AND
SATURDAY. ANOTHER...STRONGER COLD FRONT WILL APPROACH THE AREA BY
EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
...SURVEY TEAM HEADED TOWARD THE VA EASTERN SHORE ATTM...
CLUSTER OF SUPERCELLS OUT AHEAD OF COLD FRONT CRNTLY MOVG OFFSHORE
WITH NUMEROUS SPECIAL MARINE WARNINGS IN EFFECT. STRONGEST STORM
FORMED OVER THE CHES BAY JUST AFTER 8 AM THEN INTENSIFIED AS IT
MOVED ONSHORE AT A CAMPGROUND IN NORTHAMPTON COUNTY ARND 830 AM.
SEVERAL REPORTS OF INJURIES WITH NUMEROUS REPORTS OF DAMAGE RECEIVED.
SEE LSRAKQ FOR LATEST DETAILS. UPDATE TO BE ISSUED ONCE SURVEY
TEAM ARRIVES ON SITE.
WILL DO A QUICK UPDATE TO GRIDS / ZFP WITH MAIN THREAT OF CONVECTION
THIS AFTRN FROM VA RT 460 ON SOUTH INTO NC AS COLD FRONT SLOWLY
SAGS SOUTH. SHWRS WITH EMBEDDED TSTRMS ACROSS THE NORTH.
PVS DSCN:
LATEST GOES WV SAT IMAGERY CONTINUES TO SHOW SHEARING OUT UPPER
DISTURBANCE OVER THE CENTRAL APPALACHIANS THIS MORNING, WITH THE
ASSOCIATED SFC BOUNDARY STALLED JUST TO OUR NW...AND EXTENDING
FROM NORTHERN NJ BACK INTO SOUTH CENTRAL PA AND NORTHERN KY.
SEEING SHOWERS REDEVELOPING AS EXPECTED OVER NORTHWESTERN VA/NC,
WITH A FEW ISO SHRAS PUSHING ACROSS FAR WESTERN AKQ PIEDMONT
COUNTIES AT 08Z. UPPER TROUGH AMPLIFYING TO THE WEST WL NUDGE THE
STALLED SFC FRONT SOUTH ACROSS THE LOCAL AREA LATER THIS MORNING
INTO TONIGHT. LATEST HRRR AND THE 00Z/24 NMM BOTH SUGGEST SHRA
ACTIVITY WILL CONTINUE TO PUSH E-NE ACROSS NORTHWESTERN HALF OF
THE CWA NOW THROUGH MID MORNING, DROPPING SE LATE THIS MORNING
INTO THE AFTERNOON, WITH THE FRONT EVENTUALLY SLOWING NEAR THE
NC/VA BORDER TONIGHT.
REGARDING SVR POTENTIAL...OVERCAST CONDITIONS AND TIMING OF
SHOWERS AND STORMS THIS MORNING AHEAD OF THE FRONTAL PASSAGE WILL
INHIBIT INSTABILITY AND ANY SIGNIFICANT INSTABILITY FOR MUCH OF
THE AREA. EXCEPTION WILL BE OVER AND SOUTH US-58 CORRIDOR OVER FAR
SOUTHERN/SE VA INTO NE NC. DEEP LYR SHEAR WILL BE A BIT MORE
FAVORABLE OVER THIS AREA AND WITH SBCAPE IN THE 1500-2000 J/KG
RANGE ALONG AND SOUTH OF THE BORDER, BEST CHANCE FOR ORGANIZED
CONVECTION WILL BE WITH LLVL CONVERGENCE/UVV ALONG DIFFERENTIAL
HEATING BOUNDARY ACROSS THE SOUTHERN TIER OF THE AREA. SEVERE
THREAT WOULD BE SHORT LIVED, BUT A FEW WET MICROBURSTS ARE
POSSIBLE OVER THIS AREA. BIGGER THREAT WILL BE WITH TRAINING
STORMS AS THE SLOWING BOUNDARY SAGS INTO THE AREA THIS AFTN/THIS
EVENING...PW`S IN THE 1.75-2" RANGE SHOULD YIELD LOCALLY HEAVY
RAINFALL, WITH DEEP LYR SW FLOW ESSENTIALLY PARALLEL TO BEST
FORCING LEADING TO A CONCERN FOR TRAINING STORMS/RAINS.
TEMPS A BIT OF A CHALLENGE TODAY GIVEN CONSIDERABLE CLOUDINESS
THROUGH THE DAY NORTH WHAT WILL LIKELY BE DEVELOPING AFTN CONVECTION
ACROSS THE SOUTH. CUT BACK HIGHS ACROSS THE NORTH SLIGHTLY (MID
80S), WHILE KEEPING SE COUNTIES IN THE UPR 80S TO ~90 DEG.
TONIGHT...
BOUNDARY LOOKS TO STALL ACROSS SERN VA/NRN NC TONIGHT INTO FRI
MORNING AS THE UPPER TROF LINGERS ACROSS THE CAROLINAS THROUGH FRI
AFTN. WHILE POPS ARE DROPPED ACROSS THE NORTH, LOW END CHC POPS
LINGER SOUTH OF THE NC BORDER. WEAK FLOW WILL BRING ONLY MODEST
INFLUX OF COOLER/DRIER AIRMASS ACROSS NORTHERN ZONES, WITH ANOTHER
MUGGY NIGHT FOR MOST. EARLY MORNING LOWS IN THE LOW TO MID 60S FAR
NORTHERN ZONES, 65 TO AROUND 70 SOUTH ELSEWHERE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
UPPER TROUGH AXIS PUSHES ACROSS FRIDAY INTO FRIDAY AFTN, WITH THE
SFC FRONT CLEARING THE CWA BY MIDDAY (STALLING JUST TO THE SOUTH
FRIDAY NIGHT). DRY FRI EXCEPT KEPT A SLIGHT CHC POP IN ACROSS NE NC
ZONES FRIDAY MORNING. THICKNESS TOOLS YIELD HIGHS IN THE L-M80S,
WHICH IS REFLECTED WELL BY THE GOING FORECAST.
WEAK CAA ACROSS THE NORTH AS HIGH PRESSURE BUILDS INTO THE AREA FROM
THE NORTH FRI NIGHT AND EARLY SATURDAY. GFS CONTINUES TO BRING
ACROSS SOME ISOLATED THUNDER BACK IN SAT AFTN AS LLVL SW FLOW
DEVELOPS AND PUSHES STALLED FRONT BACK NORTH. HOWEVER, WITH BEST
FORCING PASSING REGION WELL TO THE NORTH, AND WITH STRONG MIDLEVEL
CAP (INVERSION) EVIDENT ON FORECAST CROSS SECTIONS, THINKING IS THAT
OUR REGION WILL REMAIN DRY SATURDAY AND SAT NIGHT. HIGHS SAT 85-90.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
LONG TERM PERIOD STARTS OFF SAT NGT INTO SUN WITH AN UPR-LEVEL TROF
DIGGING OVR THE ERN CONUS AND SFC HI PRES PUSHING OFFSHORE. A
COMPLEX AREA OF SFC LO PRES WILL DEVELOP ACROSS THE GREAT LAKES
REGION...WITH A PREFRNTAL LEE TROF LEADING TO A CHANCE OF SHRAS/TSTMS
OVR THE LOCAL AREA. WITH DEEP S/SW FLOW...TEMPS WILL BE ABOUT FIVE
DEGREES ABOVE NORMAL...HIGHS IN THE LO TO MID 90S. THE
AFOREMENTIONED SFC LO WILL PUSH E AND DRAG A COLD FRNT INTO THE MID
ATLANTIC REGION MON/MON NGT. INCLUDED A 40% CHANCE OF SHRAS/TSTMS
DURING THIS TIME PERIOD. HIGHS MON IN THE UPR 80S TO LWR 90S. ASIDE
FM A LO CHANCE OF RAIN NEAR THE CST...CONDITIONS WILL DRY OUT FOR
TUE AND WED...WITH HIGHS ONLY IN THE MID 80S.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
ISOLATED TO SCATTERED THUNDERSTORMS WILL LINGER OVER THE MD/VA
LOWER EASTERN SHORE IN THE VICINITY OF A THERMAL TROUGH THROUGH AT
LEAST 24/1000Z. AFTER WHICH...INCREASING CLOUD COVER AHEAD OF A
COLD FRONT NEAR THE WV/VA BORDER WILL OVERSPREAD THE ENTIRE AREA.
PATCHY FOG IS POSSIBLE FROM KSBY TO KLKU WITH CONDITIONS IMPROVING
AS THE NEXT BATCH OF RAIN MOVES EWD THIS MORNING...JUST AHEAD OF
THE FRONT. THUNDERSTORM DEVELOPMENT WILL BECOME FOCUSED ALONG THE
COLD FRONT AS THE DAY PROGRESSES...WITH BEST CHANCES EXPECTED TO
OCCUR SOUTHEAST OF KRIC. STORMS ARE NOT ANTICIPATED TO BECOME
SEVERE...HOWEVER LOCALLY STRONG WIND GUSTS AND BRIEF HEAVY
RAINFALL SHOULD BE THE MAIN IMPACTS TODAY. CONDITIONS DRY OUT FROM
NORTHWEST TO SOUTHEAST LATE THIS EVENING AND OVERNIGHT AS THE
FRONT STALLS ALONG THE NC COAST AFTER MIDNIGHT INTO FRIDAY
MORNING. LINGERING SHOWERS WILL BE POSSIBLE ACROSS FAR SE VA/NE NC
ON FRIDAY UNTIL THE FRONT PUSHES FARTHER TO THE SOUTHEAST AND HIGH
PRESSURE BUILDS INTO THE REGION FROM THE WNW. THE HIGH THEN SLIDES
OFF THE MID ATLANTIC COAST BY SATURDAY...BRINGING A RETURN TO
RAIN-FREE CONDITIONS DURING MOST OF THE WEEKEND. THE NEXT COLD
FRONT APPROACHES THE REGION ON SUNDAY. IT IS EXPECTED TO CROSS THE
REGION SUNDAY NIGHT AND THEN STALL NEAR THE MID ATLANTIC COAST
MON/TUE.
NOTE: OBSERVATIONS FROM KSBY ARE NOT READILY AVAILABLE DUE TO A
COMMUNICATIONS PROBLEM. RETURN TO SERVICE IS UNKNOWN AT THIS TIME.
HOWEVER...CURRENT INFORMATION MAY BE OBTAINED BY CALLING INTO THE
ASOS SITE DIRECTLY. AMD NOT SKED WILL BE APPENDED TO THE KSBY TAF
UNTIL FURTHER NOTICE.
&&
.MARINE...
AN APPROACHING COLD FRONT IS POSITIONED ALONG THE NEW ENGLAND
COAST TO SRN NJ AND THEN CUTS WWD ACROSS NRN VA AS OF 330 AM THIS
MORNING. THIS FRONT WILL SLOWLY CROSS THE WATERS TODAY AND
THUNDERSTORM CHANCES WILL INCREASE AS THE DAY PROGRESSES. MAIN
IMPACTS WILL BE LOCALIZED STRONG WIND GUSTS AND BRIEF HEAVY
RAINFALL. THE COLD FRONT STALLS ALONG THE NC COAST LATER THIS
EVENING INTO FRI MORNING...THEN PUSHES FARTHER TO THE SOUTHEAST
FOR THE REST OF THE WEEKEND. WSW TO WNW WINDS WILL PREVAIL THIS
MORNING...THEN BECOME NW-N THIS AFTN THROUGH FRI MORNING (AOB 15 KT).
WAVES GENERALLY 1-2 FT TODAY THROUGH FRIDAY...WHILE SEAS AVERAGE
1-3 FT DURING THE SAME TIME.
AN UPPER LEVEL TROUGH PUSHES ACROSS THE WATERS ON FRI AS SFC HIGH
PRESSURE BUILDS BACK INTO THE MID ATLANTIC REGION. WINDS N-NE AOB
10 KT FRI/FRI NIGHT. THE SFC HIGH THEN SLIDES OFF THE MID ATLANTIC
COAST BY SAT MORNING WITH WEAK CAA OCCURRING BEHIND ITS DEPARTURE.
THIS WILL MARK A RETURN TO ONSHORE E-SE WINDS AOB 15 KT THROUGH THE
REST OF THE WEEKEND. AN APPROACHING COLD FRONT ON SUNDAY WILL CAUSE
THE PRESSURE GRADIENT TO TIGHTEN AND A SLY SURGE IN WINDS IS
ANTICIPATED SAT NIGHT. THIS MAY PUSH SPEEDS INTO LOW-END SCA FOR
CHES BAY AND CURRITUCK SOUND (AOB 20 KT)...HOWEVER WAA PROCESSES MAY
PREVENT THIS FROM ACTUALLY HAPPENING. WILL MONITOR MODEL TRENDS OVER
THE NEXT FEW DAYS TO DETERMINE IF SCA HEADLINES ARE NECESSARY. THE
COLD FRONT IS EXPECTED TO CROSS THE WATERS LATE MON/MON NIGHT.
&&
.EQUIPMENT...
KDOX RADAR HAS RETURNED TO SERVICE BUT REMAINS UNSTABLE.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MPR/MAM
SHORT TERM...MAM
LONG TERM...MAS
AVIATION...BMD
MARINE...BMD
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
427 AM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONT PUSHES ACROSS THE REGION LATER TODAY...THEN
DISSIPATES ACROSS THE CAROLINAS LATE TONIGHT THROUGH FRIDAY.
MEANWHILE, HIGH PRESSURE BUILDS NORTH OF THE AREA FRIDAY AND
SATURDAY. ANOTHER...STRONGER COLD FRONT WILL APPROACH THE AREA BY
EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST GOES WV SAT IMAGERY CONTINUES TO SHOW SHEARING OUT UPPER
DISTURBANCE OVER THE CENTRAL APPALACHIANS THIS MORNING, WITH THE
ASSOCIATED SFC BOUNDARY STALLED JUST TO OUR NW...AND EXTENDING FROM
NORTHERN NJ BACK INTO SOUTH CENTRAL PA AND NORTHERN KY.
SEEING SHOWERS REDEVELOPING AS EXPECTED OVER NORTHWESTERN VA/NC,
WITH A FEW ISO SHRAS PUSHING ACROSS FAR WESTERN AKQ PIEDMONT
COUNTIES AT 08Z. UPPER TROUGH AMPLIFYING TO THE WEST WL NUDGE THE
STALLED SFC FRONT SOUTH ACROSS THE LOCAL AREA LATER THIS MORNING
INTO TONIGHT. LATEST HRRR AND THE 00Z/24 NMM BOTH SUGGEST SHRA
ACTIVITY WILL CONTINUE TO PUSH E-NE ACROSS NORTHWESTERN HALF OF
THE CWA NOW THROUGH MID MORNING, DROPPING SE LATE THIS MORNING
INTO THE AFTERNOON, WITH THE FRONT EVENTUALLY SLOWING NEAR THE
NC/VA BORDER TONIGHT.
REGARDING SVR POTENTIAL...OVERCAST CONDITIONS AND TIMING OF
SHOWERS AND STORMS THIS MORNING AHEAD OF THE FRONTAL PASSAGE WILL
INHIBIT INSTABILITY AND ANY SIGNIFICANT INSTABILITY FOR MUCH OF
THE AREA. EXCEPTION WILL BE OVER AND SOUTH US-58 CORRIDOR OVER FAR
SOUTHERN/SE VA INTO NE NC. DEEP LYR SHEAR WILL BE A BIT MORE
FAVORABLE OVER THIS AREA AND WITH SBCAPE IN THE 1500-2000 J/KG
RANGE ALONG AND SOUTH OF THE BORDER, BEST CHANCE FOR ORGANIZED
CONVECTION WILL BE WITH LLVL CONVERGENCE/UVV ALONG DIFFERENTIAL
HEATING BOUNDARY ACROSS THE SOUTHERN TIER OF THE AREA. SEVERE
THREAT WOULD BE SHORT LIVED, BUT A FEW WET MICROBURSTS ARE
POSSIBLE OVER THIS AREA. BIGGER THREAT WILL BE WITH TRAINING
STORMS AS THE SLOWING BOUNDARY SAGS INTO THE AREA THIS AFTN/THIS
EVENING...PW`S IN THE 1.75-2" RANGE SHOULD YIELD LOCALLY HEAVY
RAINFALL, WITH DEEP LYR SW FLOW ESSENTIALLY PARALLEL TO BEST
FORCING LEADING TO A CONCERN FOR TRAINING STORMS/RAINS.
TEMPS A BIT OF A CHALLENGE TODAY GIVEN CONSIDERABLE CLOUDINESS
THROUGH THE DAY NORTH WHAT WILL LIKELY BE DEVELOPING AFTN CONVECTION
ACROSS THE SOUTH. CUT BACK HIGHS ACROSS THE NORTH SLIGHTLY (MID
80S), WHILE KEEPING SE COUNTIES IN THE UPR 80S TO ~90 DEG.
TONIGHT...
BOUNDARY LOOKS TO STALL ACROSS SERN VA/NRN NC TONIGHT INTO FRI
MORNING AS THE UPPER TROF LINGERS ACROSS THE CAROLINAS THROUGH FRI
AFTN. WHILE POPS ARE DROPPED ACROSS THE NORTH, LOW END CHC POPS
LINGER SOUTH OF THE NC BORDER. WEAK FLOW WILL BRING ONLY MODEST
INFLUX OF COOLER/DRIER AIRMASS ACROSS NORTHERN ZONES, WITH ANOTHER
MUGGY NIGHT FOR MOST. EARLY MORNING LOWS IN THE LOW TO MID 60S FAR
NORTHERN ZONES, 65 TO AROUND 70 SOUTH ELSEWHERE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
UPPER TROUGH AXIS PUSHES ACROSS FRIDAY INTO FRIDAY AFTN, WITH THE
SFC FRONT CLEARING THE CWA BY MIDDAY (STALLING JUST TO THE SOUTH
FRIDAY NIGHT). DRY FRI EXCEPT KEPT A SLIGHT CHC POP IN ACROSS NE NC
ZONES FRIDAY MORNING. THICKNESS TOOLS YIELD HIGHS IN THE L-M80S,
WHICH IS REFLECTED WELL BY THE GOING FORECAST.
WEAK CAA ACROSS THE NORTH AS HIGH PRESSURE BUILDS INTO THE AREA FROM
THE NORTH FRI NIGHT AND EARLY SATURDAY. GFS CONTINUES TO BRING
ACROSS SOME ISOLATED THUNDER BACK IN SAT AFTN AS LLVL SW FLOW
DEVELOPS AND PUSHES STALLED FRONT BACK NORTH. HOWEVER, WITH BEST
FORCING PASSING REGION WELL TO THE NORTH, AND WITH STRONG MIDLEVEL
CAP (INVERSION) EVIDENT ON FORECAST CROSS SECTIONS, THINKING IS THAT
OUR REGION WILL REMAIN DRY SATURDAY AND SAT NIGHT. HIGHS SAT 85-90.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
LONG TERM PERIOD STARTS OFF SAT NGT INTO SUN WITH AN UPR-LEVEL TROF
DIGGING OVR THE ERN CONUS AND SFC HI PRES PUSHING OFFSHORE. A
COMPLEX AREA OF SFC LO PRES WILL DEVELOP ACROSS THE GREAT LAKES
REGION...WITH A PREFRNTAL LEE TROF LEADING TO A CHANCE OF SHRAS/TSTMS
OVR THE LOCAL AREA. WITH DEEP S/SW FLOW...TEMPS WILL BE ABOUT FIVE
DEGREES ABOVE NORMAL...HIGHS IN THE LO TO MID 90S. THE
AFOREMENTIONED SFC LO WILL PUSH E AND DRAG A COLD FRNT INTO THE MID
ATLANTIC REGION MON/MON NGT. INCLUDED A 40% CHANCE OF SHRAS/TSTMS
DURING THIS TIME PERIOD. HIGHS MON IN THE UPR 80S TO LWR 90S. ASIDE
FM A LO CHANCE OF RAIN NEAR THE CST...CONDITIONS WILL DRY OUT FOR
TUE AND WED...WITH HIGHS ONLY IN THE MID 80S.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
ISOLATED TO SCATTERED THUNDERSTORMS WILL LINGER OVER THE MD/VA
LOWER EASTERN SHORE IN THE VICINITY OF A THERMAL TROUGH THROUGH AT
LEAST 24/1000Z. AFTER WHICH...INCREASING CLOUD COVER AHEAD OF A
COLD FRONT NEAR THE WV/VA BORDER WILL OVERSPREAD THE ENTIRE AREA.
PATCHY FOG IS POSSIBLE FROM KSBY TO KLKU WITH CONDITIONS IMPROVING
AS THE NEXT BATCH OF RAIN MOVES EWD THIS MORNING...JUST AHEAD OF
THE FRONT. THUNDERSTORM DEVELOPMENT WILL BECOME FOCUSED ALONG THE
COLD FRONT AS THE DAY PROGRESSES...WITH BEST CHANCES EXPECTED TO
OCCUR SOUTHEAST OF KRIC. STORMS ARE NOT ANTICIPATED TO BECOME
SEVERE...HOWEVER LOCALLY STRONG WIND GUSTS AND BRIEF HEAVY
RAINFALL SHOULD BE THE MAIN IMPACTS TODAY. CONDITIONS DRY OUT FROM
NORTHWEST TO SOUTHEAST LATE THIS EVENING AND OVERNIGHT AS THE
FRONT STALLS ALONG THE NC COAST AFTER MIDNIGHT INTO FRIDAY
MORNING. LINGERING SHOWERS WILL BE POSSIBLE ACROSS FAR SE VA/NE NC
ON FRIDAY UNTIL THE FRONT PUSHES FARTHER TO THE SOUTHEAST AND HIGH
PRESSURE BUILDS INTO THE REGION FROM THE WNW. THE HIGH THEN SLIDES
OFF THE MID ATLANTIC COAST BY SATURDAY...BRINGING A RETURN TO
RAIN-FREE CONDITIONS DURING MOST OF THE WEEKEND. THE NEXT COLD
FRONT APPROACHES THE REGION ON SUNDAY. IT IS EXPECTED TO CROSS THE
REGION SUNDAY NIGHT AND THEN STALL NEAR THE MID ATLANTIC COAST
MON/TUE.
NOTE: OBSERVATIONS FROM KSBY ARE NOT READILY AVAILABLE DUE TO A
COMMUNICATIONS PROBLEM. RETURN TO SERVICE IS UNKNOWN AT THIS TIME.
HOWEVER...CURRENT INFORMATION MAY BE OBTAINED BY CALLING INTO THE
ASOS SITE DIRECTLY. AMD NOT SKED WILL BE APPENDED TO THE KSBY TAF
UNTIL FURTHER NOTICE.
&&
.MARINE...
AN APPROACHING COLD FRONT IS POSITIONED ALONG THE NEW ENGLAND
COAST TO SRN NJ AND THEN CUTS WWD ACROSS NRN VA AS OF 330 AM THIS
MORNING. THIS FRONT WILL SLOWLY CROSS THE WATERS TODAY AND
THUNDERSTORM CHANCES WILL INCREASE AS THE DAY PROGRESSES. MAIN
IMPACTS WILL BE LOCALIZED STRONG WIND GUSTS AND BRIEF HEAVY
RAINFALL. THE COLD FRONT STALLS ALONG THE NC COAST LATER THIS
EVENING INTO FRI MORNING...THEN PUSHES FARTHER TO THE SOUTHEAST
FOR THE REST OF THE WEEKEND. WSW TO WNW WINDS WILL PREVAIL THIS
MORNING...THEN BECOME NW-N THIS AFTN THROUGH FRI MORNING (AOB 15 KT).
WAVES GENERALLY 1-2 FT TODAY THROUGH FRIDAY...WHILE SEAS AVERAGE
1-3 FT DURING THE SAME TIME.
AN UPPER LEVEL TROUGH PUSHES ACROSS THE WATERS ON FRI AS SFC HIGH
PRESSURE BUILDS BACK INTO THE MID ATLANTIC REGION. WINDS N-NE AOB
10 KT FRI/FRI NIGHT. THE SFC HIGH THEN SLIDES OFF THE MID ATLANTIC
COAST BY SAT MORNING WITH WEAK CAA OCCURRING BEHIND ITS DEPARTURE.
THIS WILL MARK A RETURN TO ONSHORE E-SE WINDS AOB 15 KT THROUGH THE
REST OF THE WEEKEND. AN APPROACHING COLD FRONT ON SUNDAY WILL CAUSE
THE PRESSURE GRADIENT TO TIGHTEN AND A SLY SURGE IN WINDS IS
ANTICIPATED SAT NIGHT. THIS MAY PUSH SPEEDS INTO LOW-END SCA FOR
CHES BAY AND CURRITUCK SOUND (AOB 20 KT)...HOWEVER WAA PROCESSES MAY
PREVENT THIS FROM ACTUALLY HAPPENING. WILL MONITOR MODEL TRENDS OVER
THE NEXT FEW DAYS TO DETERMINE IF SCA HEADLINES ARE NECESSARY. THE
COLD FRONT IS EXPECTED TO CROSS THE WATERS LATE MON/MON NIGHT.
&&
.EQUIPMENT...
KDOX RADAR HAS RETURNED TO SERVICE BUT REMAINS UNSTABLE.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...MAM
LONG TERM...MAS
AVIATION...BMD
MARINE...BMD
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
408 AM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONT PUSHES ACROSS THE REGION LATE TONIGHT AND THURSDAY...
THEN DISSIPATES ACROSS THE CAROLINAS FRIDAY THROUGH SATURDAY AS
HIGH PRESSURE MOVES NORTH OF THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST GOES WV SAT IMAGERY CONTINUES TO SHOW SHEARING OUT UPPER
DISTURBANCE OVER THE CENTRAL APPALACHIANS THIS MORNING, WITH THE
ASSOCIATED SFC BOUNDARY STALLED JUST TO OUR NW...AND EXTENDING FROM
NORTHERN NJ BACK INTO SOUTH CENTRAL PA AND NORTHERN KY.
SEEING SHOWERS REDEVELOPING AS EXPECTED OVER NORTHWESTERN VA/NC,
WITH A FEW ISO SHRAS PUSHING ACROSS FAR WESTERN AKQ PIEDMONT
COUNTIES AT 08Z. UPPER TROUGH AMPLIFYING TO THE WEST WL NUDGE THE
STALLED SFC FRONT SOUTH ACROSS THE LOCAL AREA LATER THIS MORNING
INTO TONIGHT. LATEST HRRR AND THE 00Z/24 NMM BOTH SUGGEST SHRA
ACTIVITY WILL CONTINUE TO PUSH E-NE ACROSS NORTHWESTERN HALF OF
THE CWA NOW THROUGH MID MORNING, DROPPING SE LATE THIS MORNING
INTO THE AFTERNOON, WITH THE FRONT EVENTUALLY SLOWING NEAR THE
NC/VA BORDER TONIGHT.
REGARDING SVR POTENTIAL...OVERCAST CONDITIONS AND TIMING OF
SHOWERS AND STORMS THIS MORNING AHEAD OF THE FRONTAL PASSAGE WILL
INHIBIT INSTABILITY AND ANY SIGNIFICANT INSTABILITY FOR MUCH OF
THE AREA. EXCEPTION WILL BE OVER AND SOUTH US-58 CORRIDOR OVER FAR
SOUTHERN/SE VA INTO NE NC. DEEP LYR SHEAR WILL BE A BIT MORE
FAVORABLE OVER THIS AREA AND WITH SBCAPE IN THE 1500-2000 J/KG
RANGE ALONG AND SOUTH OF THE BORDER, BEST CHANCE FOR ORGANIZED
CONVECTION WILL BE WITH LLVL CONVERGENCE/UVV ALONG DIFFERENTIAL
HEATING BOUNDARY ACROSS THE SOUTHERN TIER OF THE AREA. SEVERE
THREAT WOULD BE SHORT LIVED, BUT A FEW WET MICROBURSTS ARE
POSSIBLE OVER THIS AREA. BIGGER THREAT WILL BE WITH TRAINING
STORMS AS THE SLOWING BOUNDARY SAGS INTO THE AREA THIS AFTN/THIS
EVENING...PW`S IN THE 1.75-2" RANGE SHOULD YIELD LOCALLY HEAVY
RAINFALL, WITH DEEP LYR SW FLOW ESSENTIALLY PARALLEL TO BEST
FORCING LEADING TO A CONCERN FOR TRAINING STORMS/RAINS.
TEMPS A BIT OF A CHALLENGE TODAY GIVEN CONSIDERABLE CLOUDINESS
THROUGH THE DAY NORTH WHAT WILL LIKELY BE DEVELOPING AFTN CONVECTION
ACROSS THE SOUTH. CUT BACK HIGHS ACROSS THE NORTH SLIGHTLY (MID
80S), WHILE KEEPING SE COUNTIES IN THE UPR 80S TO ~90 DEG.
TONIGHT...
BOUNDARY LOOKS TO STALL ACROSS SERN VA/NRN NC TONIGHT INTO FRI
MORNING AS THE UPPER TROF LINGERS ACROSS THE CAROLINAS THROUGH FRI
AFTN. WHILE POPS ARE DROPPED ACROSS THE NORTH, LOW END CHC POPS
LINGER SOUTH OF THE NC BORDER. WEAK FLOW WILL BRING ONLY MODEST
INFLUX OF COOLER/DRIER AIRMASS ACROSS NORTHERN ZONES, WITH ANOTHER
MUGGY NIGHT FOR MOST. EARLY MORNING LOWS IN THE LOW TO MID 60S FAR
NORTHERN ZONES, 65 TO AROUND 70 SOUTH ELSEWHERE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
UPPER TROUGH AXIS PUSHES ACROSS FRIDAY INTO FRIDAY AFTN, WITH THE
SFC FRONT CLEARING THE CWA BY MIDDAY (STALLING JUST TO THE SOUTH
FRIDAY NIGHT). DRY FRI EXCEPT KEPT A SLIGHT CHC POP IN ACROSS NE NC
ZONES FRIDAY MORNING. THICKNESS TOOLS YIELD HIGHS IN THE L-M80S,
WHICH IS REFLECTED WELL BY THE GOING FORECAST.
WEAK CAA ACROSS THE NORTH AS HIGH PRESSURE BUILDS INTO THE AREA FROM
THE NORTH FRI NIGHT AND EARLY SATURDAY. GFS CONTINUES TO BRING
ACROSS SOME ISOLATED THUNDER BACK IN SAT AFTN AS LLVL SW FLOW
DEVELOPS AND PUSHES STALLED FRONT BACK NORTH. HOWEVER, WITH BEST
FORCING PASSING REGION WELL TO THE NORTH, AND WITH STRONG MIDLEVEL
CAP (INVERSION) EVIDENT ON FORECAST CROSS SECTIONS, THINKING IS THAT
OUR REGION WILL REMAIN DRY SATURDAY AND SAT NIGHT. HIGHS SAT 85-90.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
LONG TERM PERIOD STARTS OFF SAT NGT INTO SUN WITH AN UPR-LEVEL TROF
DIGGING OVR THE ERN CONUS AND SFC HI PRES PUSHING OFFSHORE. A
COMPLEX AREA OF SFC LO PRES WILL DEVELOP ACROSS THE GREAT LAKES
REGION...WITH A PREFRNTAL LEE TROF LEADING TO A CHANCE OF SHRAS/TSTMS
OVR THE LOCAL AREA. WITH DEEP S/SW FLOW...TEMPS WILL BE ABOUT FIVE
DEGREES ABOVE NORMAL...HIGHS IN THE LO TO MID 90S. THE
AFOREMENTIONED SFC LO WILL PUSH E AND DRAG A COLD FRNT INTO THE MID
ATLANTIC REGION MON/MON NGT. INCLUDED A 40% CHANCE OF SHRAS/TSTMS
DURING THIS TIME PERIOD. HIGHS MON IN THE UPR 80S TO LWR 90S. ASIDE
FM A LO CHANCE OF RAIN NEAR THE CST...CONDITIONS WILL DRY OUT FOR
TUE AND WED...WITH HIGHS ONLY IN THE MID 80S.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
ISOLATED TO SCATTERED THUNDERSTORMS WILL LINGER OVER THE MD/VA
LOWER EASTERN SHORE IN THE VICINITY OF A THERMAL TROUGH THROUGH AT
LEAST 24/1000Z. AFTER WHICH...INCREASING CLOUD COVER AHEAD OF A
COLD FRONT NEAR THE WV/VA BORDER WILL OVERSPREAD THE ENTIRE AREA.
PATCHY FOG IS POSSIBLE FROM KSBY TO KLKU WITH CONDITIONS IMPROVING
AS THE NEXT BATCH OF RAIN MOVES EWD THIS MORNING...JUST AHEAD OF
THE FRONT. THUNDERSTORM DEVELOPMENT WILL BECOME FOCUSED ALONG THE
COLD FRONT AS THE DAY PROGRESSES...WITH BEST CHANCES EXPECTED TO
OCCUR SOUTHEAST OF KRIC. STORMS ARE NOT ANTICIPATED TO BECOME
SEVERE...HOWEVER LOCALLY STRONG WIND GUSTS AND BRIEF HEAVY
RAINFALL SHOULD BE THE MAIN IMPACTS TODAY. CONDITIONS DRY OUT FROM
NORTHWEST TO SOUTHEAST LATE THIS EVENING AND OVERNIGHT AS THE
FRONT STALLS ALONG THE NC COAST AFTER MIDNIGHT INTO FRIDAY
MORNING. LINGERING SHOWERS WILL BE POSSIBLE ACROSS FAR SE VA/NE NC
ON FRIDAY UNTIL THE FRONT PUSHES FARTHER TO THE SOUTHEAST AND HIGH
PRESSURE BUILDS INTO THE REGION FROM THE WNW. THE HIGH THEN SLIDES
OFF THE MID ATLANTIC COAST BY SATURDAY...BRINGING A RETURN TO
RAIN-FREE CONDITIONS DURING MOST OF THE WEEKEND. THE NEXT COLD
FRONT APPROACHES THE REGION ON SUNDAY. IT IS EXPECTED TO CROSS THE
REGION SUNDAY NIGHT AND THEN STALL NEAR THE MID ATLANTIC COAST
MON/TUE.
NOTE: OBSERVATIONS FROM KSBY ARE NOT READILY AVAILABLE DUE TO A
COMMUNICATIONS PROBLEM. RETURN TO SERVICE IS UNKNOWN AT THIS TIME.
HOWEVER...CURRENT INFORMATION MAY BE OBTAINED BY CALLING INTO THE
ASOS SITE DIRECTLY. AMD NOT SKED WILL BE APPENDED TO THE KSBY TAF
UNTIL FURTHER NOTICE.
&&
.MARINE...
AN APPROACHING COLD FRONT IS POSITIONED ALONG THE NEW ENGLAND
COAST TO SRN NJ AND THEN CUTS WWD ACROSS NRN VA AS OF 330 AM THIS
MORNING. THIS FRONT WILL SLOWLY CROSS THE WATERS TODAY AND
THUNDERSTORM CHANCES WILL INCREASE AS THE DAY PROGRESSES. MAIN
IMPACTS WILL BE LOCALIZED STRONG WIND GUSTS AND BRIEF HEAVY
RAINFALL. THE COLD FRONT STALLS ALONG THE NC COAST LATER THIS
EVENING INTO FRI MORNING...THEN PUSHES FARTHER TO THE SOUTHEAST
FOR THE REST OF THE WEEKEND. WSW TO WNW WINDS WILL PREVAIL THIS
MORNING...THEN BECOME NW-N THIS AFTN THROUGH FRI MORNING (AOB 15 KT).
WAVES GENERALLY 1-2 FT TODAY THROUGH FRIDAY...WHILE SEAS AVERAGE
1-3 FT DURING THE SAME TIME.
AN UPPER LEVEL TROUGH PUSHES ACROSS THE WATERS ON FRI AS SFC HIGH
PRESSURE BUILDS BACK INTO THE MID ATLANTIC REGION. WINDS N-NE AOB
10 KT FRI/FRI NIGHT. THE SFC HIGH THEN SLIDES OFF THE MID ATLANTIC
COAST BY SAT MORNING WITH WEAK CAA OCCURRING BEHIND ITS DEPARTURE.
THIS WILL MARK A RETURN TO ONSHORE E-SE WINDS AOB 15 KT THROUGH THE
REST OF THE WEEKEND. AN APPROACHING COLD FRONT ON SUNDAY WILL CAUSE
THE PRESSURE GRADIENT TO TIGHTEN AND A SLY SURGE IN WINDS IS
ANTICIPATED SAT NIGHT. THIS MAY PUSH SPEEDS INTO LOW-END SCA FOR
CHES BAY AND CURRITUCK SOUND (AOB 20 KT)...HOWEVER WAA PROCESSES MAY
PREVENT THIS FROM ACTUALLY HAPPENING. WILL MONITOR MODEL TRENDS OVER
THE NEXT FEW DAYS TO DETERMINE IF SCA HEADLINES ARE NECESSARY. THE
COLD FRONT IS EXPECTED TO CROSS THE WATERS LATE MON/MON NIGHT.
&&
.EQUIPMENT...
KDOX RADAR HAS RETURNED TO SERVICE BUT REMAINS UNSTABLE.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...MAM
LONG TERM...MAS
AVIATION...BMD
MARINE...BMD
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
402 AM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONT PUSHES ACROSS THE REGION LATE TONIGHT AND THURSDAY...
THEN DISSIPATES ACROSS THE CAROLINAS FRIDAY THROUGH SATURDAY AS
HIGH PRESSURE MOVES NORTH OF THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST GOES WV SAT IMAGERY CONTINUES TO SHOW SHEARING OUT UPPER
DISTURBANCE OVER THE CENTRAL APPALACHIANS THIS MORNING, WITH THE
ASSOCIATED SFC BOUNDARY STALLED JUST TO OUR NW...AND EXTENDING FROM
NORTHERN NJ BACK INTO SOUTH CENTRAL PA AND NORTHERN KY.
SEEING SHOWERS REDEVELOPING AS EXPECTED OVER NORTHWESTERN VA/NC,
WITH A FEW ISO SHRAS PUSHING ACROSS FAR WESTERN AKQ PIEDMONT
COUNTIES AT 08Z. UPPER TROUGH AMPLIFING TO THE WEST WL NUDGE THE
STALLED SFC FRONT SOUTH ACROSS THE LOCAL AREA LATER THIS MORNING
INTO TONIGHT. LATEST HRRR AND THE 00Z/24 NMM BOTH SUGGEST SHRA
ACTIVITY WILL CONTINUE TO PUSH E-NE ACROSS NORTHWESTERN HALF OF
THE CWA NOW THROUGH MID MORNING, DROPPING SE LATE THIS MORNING
INTO THE AFTERNOON, WITH THE FRONT EVENTUALLY SLOWING NEAR THE
NC/VA BORDER TONIGHT.
REGARDING SVR POTENTIAL...OVERCAST CONDITIONS AND TIMING OF
SHOWERS AND STORMS THIS MORNING AHEAD OF THE FRONTAL PASSAGE WILL
INHIBIT INSTABILITY AND ANY SIGNIFICANT INSTABILITY FOR MUCH OF
THE AREA. EXCEPTION WILL BE OVER AND SOUTH US-58 CORRIDOR OVER FAR
SOUTHERN/SE VA INTO NE NC. DEEP LYR SHEAR WILL BE A BIT MORE
FAVORABLE OVER THIS AREA AND WITH SBCAPE IN THE 1500-2000 J/KG
RANGE ALONG AND SOUTH OF THE BORDER, BEST CHANCE FOR ORGANIZED
CONVECTION WILL BE WITH LLVL CONVERGENCE/UVV ALONG DIFFERENTIAL
HEATING BOUNDARY ACROSS THE SOUTHERN TIER OF THE AREA. SEVERE
THREAT WOULD BE SHORT LIVED, BUT A FEW WET MICROBURSTS ARE
POSSIBLE OVER THIS AREA. BIGGER THREAT WILL BE WITH TRAINING
STORMS AS THE SLOWING BOUNDARY SAGS INTO THE AREA THIS AFTN/THIS
EVENING...PW`S IN THE 1.75-2" RANGE SHOULD YIELD LOCALLY HEAVY
RAINFALL, WITH DEEP LYR SW FLOW ESSENTIALLY PARALLEL TO BEST
FORCING LEADING TO A CONCERN FOR TRAINING STORMS/RAINS.
TEMPS A BIT OF A CHALLENGE TODAY GIVEN CONSIDERABLE CLOUDINESS
THROUGH THE DAY NORTH WHAT WILL LIKELY BE DEVELOPING AFTN CONVECTION
ACROSS THE SOUTH. CUT BACK HIGHS ACROSS THE NORTH SLIGHTLY (MID
80S), WHILE KEEPING SE COUNTIES IN THE UPR 80S TO ~90 DEG.
TONIGHT...
BOUNDARY LOOKS TO STALL ACROSS SERN VA/NRN NC TONIGHT INTO FRI
MORNING AS THE UPPER TROF LINGERS ACROSS THE CAROLINAS THROUGH FRI
AFTN. WHILE POPS ARE DROPPED ACROSS THE NORTH, LOW END CHC POPS
LINGER SOUTH OF THE NC BORDER. WEAK FLOW WILL BRING ONLY MODEST
INFLUX OF COOLER/DRIER AIRMASS ACROSS NORTHERN ZONES, WITH ANOTHER
MUGGY NIGHT FOR MOST. EARLY MORNING LOWS IN THE LOW TO MID 60S FAR
NORTHERN ZONES, 65 TO AROUND 70 SOUTH ELSEWHERE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
UPPER TROUGH AXIS PUSHES ACROSS FRIDAY INTO FRIDAY AFTN, WITH THE
SFC FRONT CLEARING THE CWA BY MIDDAY (STALLING JUST TO THE SOUTH
FRIDAY NIGHT). DRY FRI EXCEPT KEPT A SLIGHT CHC POP IN ACROSS NE NC
ZONES FRIDAY MORNING. THICKNESS TOOLS YIELD HIGHS IN THE L-M80S,
WHICH IS REFLECTED WELL BY THE GOING FORECAST.
WEAK CAA ACROSS THE NORTH AS HIGH PRESSURE BUILDS INTO THE AREA FROM
THE NORTH FRI NIGHT AND EARLY SATURDAY. GFS CONTINUES TO BRING
ACROSS SOME ISOLATED THUNDER BACK IN SAT AFTN AS LLVL SW FLOW
DEVELOPS AND PUSHES STALLED FRONT BACK NORTH. HOWEVER, WITH BEST
FORCING PASSING REGION WELL TO THE NORTH, AND WITH STRONG MIDLEVEL
CAP (INVERSION) EVIDENT ON FORECAST CROSS SECTIONS, THINKING IS THAT
OUR REGION WILL REMAIN DRY SATURDAY AND SAT NIGHT. HIGHS SAT 85-90.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
LONG TERM PERIOD STARTS OFF SAT NGT INTO SUN WITH AN UPR-LEVEL TROF
DIGGING OVR THE ERN CONUS AND SFC HI PRES PUSHING OFFSHORE. A
COMPLEX AREA OF SFC LO PRES WILL DEVELOP ACROSS THE GREAT LAKES
REGION...WITH A PREFRNTAL LEE TROF LEADING TO A CHANCE OF SHRAS/TSTMS
OVR THE LOCAL AREA. WITH DEEP S/SW FLOW...TEMPS WILL BE ABOUT FIVE
DEGREES ABOVE NORMAL...HIGHS IN THE LO TO MID 90S. THE
AFOREMENTIONED SFC LO WILL PUSH E AND DRAG A COLD FRNT INTO THE MID
ATLANTIC REGION MON/MON NGT. INCLUDED A 40% CHANCE OF SHRAS/TSTMS
DURING THIS TIME PERIOD. HIGHS MON IN THE UPR 80S TO LWR 90S. ASIDE
FM A LO CHANCE OF RAIN NEAR THE CST...CONDITIONS WILL DRY OUT FOR
TUE AND WED...WITH HIGHS ONLY IN THE MID 80S.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
ISOLATED TO SCATTERED THUNDERSTORMS WILL LINGER OVER THE MD/VA
LOWER EASTERN SHORE IN THE VICINITY OF A THERMAL TROUGH THROUGH AT
LEAST 24/1000Z. AFTER WHICH...INCREASING CLOUD COVER AHEAD OF A
COLD FRONT NEAR THE WV/VA BORDER WILL OVERSPREAD THE ENTIRE AREA.
PATCHY FOG IS POSSIBLE FROM KSBY TO KLKU WITH CONDITIONS IMPROVING
AS THE NEXT BATCH OF RAIN MOVES EWD THIS MORNING...JUST AHEAD OF
THE FRONT. THUNDERSTORM DEVELOPMENT WILL BECOME FOCUSED ALONG THE
COLD FRONT AS THE DAY PROGRESSES...WITH BEST CHANCES EXPECTED TO
OCCUR SOUTHEAST OF KRIC. STORMS ARE NOT ANTICIPATED TO BECOME
SEVERE...HOWEVER LOCALLY STRONG WIND GUSTS AND BRIEF HEAVY
RAINFALL SHOULD BE THE MAIN IMPACTS TODAY. CONDITIONS DRY OUT FROM
NORTHWEST TO SOUTHEAST LATE THIS EVENING AND OVERNIGHT AS THE
FRONT STALLS ALONG THE NC COAST AFTER MIDNIGHT INTO FRIDAY
MORNING. LINGERING SHOWERS WILL BE POSSIBLE ACROSS FAR SE VA/NE NC
ON FRIDAY UNTIL THE FRONT PUSHES FARTHER TO THE SOUTHEAST AND HIGH
PRESSURE BUILDS INTO THE REGION FROM THE WNW. THE HIGH THEN SLIDES
OFF THE MID ATLANTIC COAST BY SATURDAY...BRINGING A RETURN TO
RAIN-FREE CONDITIONS DURING MOST OF THE WEEKEND. THE NEXT COLD
FRONT APPROACHES THE REGION ON SUNDAY. IT IS EXPECTED TO CROSS THE
REGION SUNDAY NIGHT AND THEN STALL NEAR THE MID ATLANTIC COAST
MON/TUE.
NOTE: OBSERVATIONS FROM KSBY ARE NOT READILY AVAILABLE DUE TO A
COMMUNICATIONS PROBLEM. RETURN TO SERVICE IS UNKNOWN AT THIS TIME.
HOWEVER...CURRENT INFORMATION MAY BE OBTAINED BY CALLING INTO THE
ASOS SITE DIRECTLY. AMD NOT SKED WILL BE APPENDED TO THE KSBY TAF
UNTIL FURTHER NOTICE.
&&
.MARINE...
SUB-SCA CONDITIONS EXPECTED THROUGH THE NEXT FEW DAYS WITH SFC HI
PRES LOCATED WELL OFFSHORE AND A FAIRLY WEAK PRES GRADIENT OVR THE
MID ATLANTIC. AHEAD OF A PREFRNTAL TROF OVR THE PIEDMONT THIS
AFTN/EVENG...SLY WINDS OVR THE BAY WILL RISE TO 10-15 KT...JUST BLO
SCA THRESHOLDS. SEAS WILL BLD TO 3-4 FT FOR NRN CSTL WTRS. A COLD
FRNT CROSSES THE WTRS ON THU...WITH WINDS SHIFTING FM SW TO NW...AND
STAYING SUB-SCA BEHIND THE FRNT DUE TO VERY WEAK CAA. BENIGN MARINE
CONDITIONS CONTINUE INTO FRI AND SAT AS SFC HI PRES BLDS INTO THE
REGION. WINDS WILL STAY AOB 10 KT WITH 1-2 FT WAVES OVR THE BAY AND
2-3 FT OVR CSTL WTRS. NEXT COLD FRNT CROSSES THE WTRS LATE MON/MON
NGT.
&&
.EQUIPMENT...
KDOX RADAR HAS RETURNED TO SERVICE BUT REMAINS UNSTABLE.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...MAM
LONG TERM...MAS
AVIATION...BMD
MARINE...MAS
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
748 PM EDT FRI JUL 25 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 343 PM EDT FRI JUL 25 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A WNW FLOW ALF
OVER THE UPR LKS BTWN DEEP CLOSED LO OVER NRN QUEBEC AND SHRTWV RDG
AXIS EXTENDING NNEWD INTO MN/NW ONTARIO FM CENTER OF HIER HGTS OVER
THE SRN ROCKIES. ALTHOUGH SLOW INFLUX OF MOISTER AIR IN THE GENERAL
SW FLOW BTWN SFC/H85 HI OVER THE MID ATLANTIC STATES AND LOWER MSLP
IN THE NRN PLAINS ASSOCIATED WITH A DEEP CLOSED LO IN SRN
SASKATCHEWAN THAT IS RIDING OVER THE RDG CENTERED IN THE SRN ROCKIES
HAS ALLOWED FOR A GOOD DEAL OF CLDS/A FEW SHOWERS OVER MAINLY THE W
HALF OF THE CWA TDAY...MAIN FOCUS FOR HEAVIER PCPN HAS BEEN WELL TO
THE SW CLOSER TO SHARP H85 WARM FNT STRETCHING FM THE DAKOTAS INTO
THE MID MS RIVER VALLEY. HI STABILITY SHOWN ON THE 12Z INL RAOB AND
ESPECIALLY THE GRB RAOB...WHICH DEPICTS A SHARP INVRN ARND H75...HAS
TENDED TO LIMIT THE INTENSITY AND COVERAGE OF THE SHOWERS THAT HAVE
IMPACTED UPR MI. OVER THE ERN CWA...VERY DRY/STABLE AIRMASS SHOWN ON
THE 12Z APX RAOB HAS ALLOWED FOR MORE SUNSHINE. BUT TO THE W...MORE
SHOWERS ARE PRESENT IN NE MN/WRN LK SUP IN AREA OF HIER H85 THETA E
ADVCTN IN ADVANCE OF A WEAK SHRTWV MOVING E ALONG THE CNDN BORDER
ARND CLOSED LO IN SASKATCHEWAN. BUT EWD PUSH OF DRIER AIR IN THE NRN
PLAINS IS TENDING TO LIMIT THE OVERALL COVERAGE OF THESE SHOWERS AS
WELL.
MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE PCPN CHCS ASSOCIATED
WITH SHRTWV NOW MOVING ALONG THE CNDN BORDER.
LATE TDAY/TNGT...EXPECT AREA OF SHOWERS NOW IN NE MN AND A FEW
TS...THE POTENTIAL OF WHICH WL BE LIMITED BY PERSISTENT HIER MID LVL
STABILITY DEPICTED BEST ON THE GFS FCST SDNGS...TO SPREAD W-E INTO
UPR MI WITH AREA OF POSITIVE H85 THETA E ADVCTN THAT WL LIFT PWAT UP
TO ARND 1.5 INCHES/AXIS OF SOME H85-5 QVECTOR CNVGC IN ADVANCE OF
SHRTWV NOW TRACKING E ALONG THE CNDN BORDER. BUT ARRIVAL OF DRY AIR
NOW IN THE NRN PLAINS WL TEND TO DIMINISH THE POPS LATER EVEN THOUGH
THERE ARE HINTS A 2ND SHRTWV MIGHT FOLLOW INTO THE UPR LKS. FCST
LARGE SCALE QVECTOR DVGC OVER THE W LATE INDICATES THE DRYING WL
OVERCOME ANY PVA ASSOCIATED WITH THIS TRAILING SHRTWV. GOING FCST
POPS ARE IN PRETTY GOOD SHAPE AND NEED ONLY SMALL ADJUSTMENTS.
DESPITE THE MID LVL DRYING LATE...DVLPG LO CLDS WL LIMIT THE DIURNAL
TEMP FALL.
SAT...ANY LINGERING MRNG SHOWERS OVER MAINLY THE NE CWA WL END WITH
ARRIVAL OF DRIER AIR ALF THAT WL DEPRESS PWAT TO 0.75-1.0 INCH/DNVA
AND DEEP LYR QVECTOR DVGC AHEAD OF SHRTWV RDG TRAILING THE DEPARTING
2ND SHRTWV. WITH MRNG LO CLDS GIVING WAY TO MORE SUNSHINE AND FCST
H85 TEMPS AS HI AS 17-18C OVER THE W BY 00Z SUN...EXPECT MAX TEMPS
TO RISE INTO THE 80S AWAY FM THE MODERATING INFLUENCE OF THE GREAT
LKS. GIVEN THE MID LVL DRYING/POTENTIAL FOR DEEP MIXING AND NEAR
ADIABATIC LLVL LAPSE RATES...PREFER THE HIER END OF GUIDANCE FOR MAX
TEMPS...AT LEAST OVER THE INTERIOR W HALF. SOME OF THE HIER RES
MODELS...MAINLY THE 12Z NAM AND REGIONAL CNDN MODEL...DO INDICATE
THIS DAYTIME HEATING WL TRIGGER SOME SHOWERS/TS OVER THE ERN CWA IN
THE AFTN WITH CONVERGING LK BREEZES OFF LKS SUP/MI UNDER SOMEHWAT
LOWER HGTS. THE MAIN LIMITING FACTOR FOR THE DLPMNT OF THESE LK
BREEZE SHOWERS/TS WL BE THE DRYING ALF THAT IS FCST TO MIX TO THE
SFC WITH THE DAYTIME HEATING. IN FACT...DEEP MIXING ON THE GFS/NAM
FCST SDNGS HINT SFC DEWPTS OVER THE INTERIOR W HALF COULD MIX OUT AS
LO AS 45-50 LATE IN THE DAY...WITH KINX DROPPING TO 15-20. THE NAM
FCST SDNG FOR NEWBERRY AT 18Z SHOWS SBCAPE ARND 2K G/KG FOR SFC T/TD
OF 75/65. PREFER THE MORE CONSERVATIVE GFS FCST FOR SFC T/TD OF
75/60 AND SBCAPE CLOSE TO 700 J/KG. DESPITE THE LIMITATION OF THE
LARGE SCALE DRYING...WL MAINTAIN SOME LO CHC POPS OVER THE ERN CWA
TO ACCOUNT FOR THE LK BREEZE CNVGC.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 407 PM EDT FRI JUL 25 2014
COOL SUMMER PATTERN PERSISTS AS LARGE SCALE TROUGHING IS FORECAST TO
CONTINUE THROUGH DAYS 7-10. TEMPERATURES REMAIN BELOW NORMAL WITH
THE COOLEST DAYS EXPECTED MONDAY AND TUESDAY AS CORE OF UPPER LOW
AND COLD AIR MOVES ACROSS GREAT LAKES. MAX TEMPS BOTH DAYS LIKELY
WILL END UP AT LEAST 10 DEGREES BELOW NORMAL. NORMAL HIGHS THIS TIME
OF YEAR ARE IN THE MID 70S TO LOW 80S. MIN TEMPS WILL BE 5 TO 10
DEGREES BELOW NORMAL. NORMAL MIN TEMPS ARE IN THE LOW TO MID 50S.
OVERALL THIS PATTERN LOOKS DRY THROUGH THE NEXT COUPLE WEEKS PER THE
MEDIUM RANGE MODELS AND LATEST CPC OUTLOOKS.
BEST SHOT OF RAIN IS LATER SATURDAY NIGHT THROUGH SUNDAY AS UPPER
LOW AND STRONGER SHORTWAVE CURRENTLY OVER SOUTHERN SASKATCHEWAN
MOVES ACROSS WITH ASSOCIATED DEEP LAYER Q-VECTOR CONVERGENCE.
PASSAGE OF SHORTWAVE OCCURS AS THE INITIAL STRONG SFC-H85 COLD FRONT
IS CROSSING THE UPPER GREAT LAKES. MAIN ISSUE IS HOW FAST WILL THE
RAIN ARRIVE SATURDAY NIGHT AND ALSO IF THERE IS ANY POTENTIAL FOR
TSRA. SI/S BARELY BUMP BLO ZERO AND THAT IS FOCUSED ALONG THE WI
BORDER. HIGHEST POPS EXPECTED JUST TO NORTH OF UPPER LOW/SHORTWAVE
TRACK...MAINLY 09Z-21Z SUNDAY. TSRA CHANCES ARE THERE...BUT ARE
LIMITED TO A CHANCE AT BEST. UNLESS THE STORMS FORM EARLIER SATURDAY
EVENING WHEN DEEP SHEAR IS 30-40 KTS AND MLCAPE IS OVER 1000 J/KG...
DO NOT EXPECT ANY SEVERE STORMS SATURDAY NIGHT. INTO SUNDAY IT IS
POSSIBLE THAT IF THE SYSTEM SLOWS THERE WOULD BE INCREASED POTENTIAL
FOR SFC BASED TSRA SUNDAY AFTN. ATTM THOUGH LI/S BLO ZERO ARE
FORECAST TO STAY OVER WI AS STABLE COOL RAINY NORTH FLOW SHUNTS THE
GREATER INSTABILITY TO THE SOUTH. LOWERED TEMPS MORE ALONG LK
SUPERIOR ON SUNDAY...WITH UPR 50S TO AROUND 60 DEGREES. POINTS
FARTHER INLAND OVER SOUTHERN U.P. MAY BE ABLE TO REACH 70 DEGREES AT
LEAST BRIEFLY BEFORE CLOUDS THICKEN AND WIDESPREAD SHOWERS BEGIN.
SHOULD NOTE THAT THE STRONGER NORTH WINDS AND HIGHER WAVES WILL
INCREASE SWIM RISK FOR BEACHES OF LK SUPERIOR MQT TO GRAND MARAIS
SUNDAY INTO MONDAY. IF THE AIR TEMPS REMAIN IN THE UPPER 50S OR
HIGHER...WOULD NEED A BEACH HAZARD STATEMENT TO HIGHLIGHT THE RISK
EITHER FOR SUNDAY OR MONDAY OR POSSIBLY BOTH DAYS. ULTIMATELY WILL
DEPEND ON THE EXPECTED WEATHER FOR THE DAY.
BEYOND SUNDAY...UPPER TROUGH IN THE VCNTY COUPLED WITH INDIVIDUAL
SHORTWAVES AND AREAS OF DEEPER MOISTURE DROPPING ACROSS THE AREA
WILL COMBINE WITH DAYTIME HEATING/INSOLATION TO PRODUCE ISOLD-SCTD
SHOWERS...MAINLY DURING AFTN AND EVENING HOURS OF TUESDAY AND
WEDNESDAY. GRADUAL RISING HEIGHTS RESULT IN LESS CYCLONIC LOW-LEVEL
FLOW BY THURSDAY AND THERE IS ALSO LESS DEEP MOISTURE BY THAT POINT.
EXPECT THE CHANCES OF DIURNAL SHOWERS TO DIMINISH BY LATE THIS WEEK
AS TEMPS BEGIN TO WARM UP AGAIN. JUST ENOUGH MLCAPE DURING THE AFTN
FAR INLAND TO PUT KEEP SMALL TSRA CHANCES AS WELL WITH THE SHRA. MEAN
WINDS FM NORTH TO SOUTH RESULT IN GREATEST CHANCES FOR RAIN MOST DAYS
FARTHEST INLAND FROM THE MODERATION/STABILIZING INFLUENCE OF LK
SUPERIOR.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 743 PM EDT FRI JUL 25 2014
A MOIST LLVL SW FLOW COMBINED WITH AN UPPER DISTURBANCE MOVING ACROSS
THE AREA HAS RESULTED IN SCT SHRA ACROSS NCNTRL UPPER MI EARLY THIS
EVENING. MUCH OF THIS SHRA ACTIVITY WILL REMAIN MOSTLY NORTH OF THE
TAF SITES THIS EVENING SO WL ONLY INCLUDE VCSH IN THE TAFS. WITH SOME
DRYING ALF LATE TNGT THAT WL END THE SHOWERS...EXPECT IFR CONDITIONS
TO DVLP IN THE PRESENCE OF DIURNAL COOLING. LIFR CONDITIONS ARE NOT
OUT OF THE QUESTION. THE ARRIVAL OF DRIER AIR AND DAYTIME WL RESULT
IN IMPROVEMENT TO VFR ON SAT. THIS PROCESS WL BE SLOWEST AT CMX WITH
AN UPSLOPE NW WIND AND AT SAW WHERE A DEVELOPING N WIND COULD CAUSE
MVFR CLOUDS TO LINGER A BIT LONGER. &&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 407 PM EDT FRI JUL 25 2014
EXPECT WINDS UNDER 15 KTS THRU SAT NIGHT WITH RELATIVELY WEAK PRES
GRADIENT DOMINATING THE UPPER LAKES. STRONGER N WINDS UP TO 20-25
KTS EXPECTED SUN INTO MON AS COOLER AIR INVADES THE AREA UNDER
TIGHTER GRADIENT BETWEEN HI PRES MOVING INTO THE NORTHERN PLAINS AND
LO PRES OVER THE SE GREAT LAKES. WINDS WILL DIMINISH ON TUE AND BACK
TOWARD THE W WITH CLOSER APPROACH OF HI PRES FROM THE PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...VOSS
MARINE...TITUS/JLA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1159 AM CDT THU JUL 24 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 354 AM CDT THU JUL 24 2014
STOUT UPPER RIDGE REMAINS CENTERED OVER COLORADO THIS MORNING...WITH
ITS ASSOCIATED RIDGE AXIS EXTENDING UP THROUGH THE CENTRAL DAKOTAS.
THIS RIDGE HAS A VERY WARM EML ASSOCIATED WITH IT /SEE +17C H7 TEMP
ON THE UNR SOUNDING LAST NIGHT/ AS WE CONTINUE TO SEE SHORTWAVES AND
ASSOCIATED STORMS ROTATE AROUND THE PERIPHERY OF THE RIDGE...THE
MOST IMPRESSIVE OF WHICH THIS MORNING IS UP IN NORTH CENTRAL
MONTANA. BY TONIGHT THE RIDGE AXIS WILL SHIFT INTO MN...THOUGH WILL
BE GETTING FLATTENED OUT BY THE H5 LOW CURRENTLY OVER WASHINGTON
THAT WILL MOVE INTO THE CANADIAN PRAIRIES OVERNIGHT.
THIS MORNING...HIGH PRESSURE CENTERED OVER WRN LAKE SUPERIOR HAS A
COOL A DRY AIRMASS IN PLACE THAT WILL LIKELY DELAY THE ARRIVAL OF
PRECIP. HAVE CUT BACK CONSIDERABLY ON POPS THROUGH THE
AFTERNOON...WITH MOST GUIDANCE SHOWING THE DAY GOING BY DRY AS THE
LLJ AND THETA-E RIDGE LOOK TO REMAIN ACROSS THE DAKOTAS THROUGH THE
DAY. THE ONLY THING TO WATCH WILL BE THAT MONTANA WAVE THAT WILL BE
DIVING SE ACROSS NODAK THIS MORNING AS IT WORKS AROUND THE RIDGE.
NMM/ARW WRFS SHOW REMNANTS OF THIS ACTIVITY WORKING ACROSS WRN MN
THIS AFTERNOON...BUT CONSIDERING THE RAP DOES NOT SHOW THE ELEVATED
INSTABILITY MAKING MUCH PROGRESS ACROSS THE DAKOTAS TODAY...FAVORED
THE DRY FORECAST FOR TODAY HIGHLIGHTED BY THE DETERMINISTIC MODELS.
BASICALLY...LEFT SOME SLIGHT CHANCES THROUGH THE AFTERNOON SW OF THE
MN RIVER...CLOSER TO WHERE THE BETTER MOISTURE TRANSPORT INTO SE
SODAK WILL BE. OTHERWISE...FEW CHANGES WERE NEEDED FOR TODAY...WITH
SRLY WINDS BRINGING IN SLIGHTLY WARMER AIR RESULTING IN HIGHS A
COUPLE OF DEGREES WARMER THAN WHAT WE SAW WEDNESDAY.
TONIGHT LOOKS TO BRING OUR BEST CHANCE FOR PRECIP OVER THE NEXT
WEEK. SOME MODEL DISAGREEMENT STILL EXISTS...WITH A COUPLE OF CAMPS
EXISTING WITH THE NAM/GFS/ECMWF CONTINUING TO HIGHLIGHT THE
POTENTIAL FOR WIDESPREAD ELEVATED CONVECTION FROM SOUTH CENTRAL MN
INTO NE IA...WHILE THE GEM AND WRF BASED CAMS SHOW CONSIDERABLY LESS
ACTIVITY IN THE MPX AREA...WITH TWO AREAS OF CONVECTION DEVELOPING
OVERNIGHT DOWN ACROSS IA AND ACROSS CENTRAL/NRN MN. THE FIRST OF THE
SOLUTIONS MAINTAINS GOOD CONTINUITY WITH THE EXISTING FORECAST...SO
FAVORED THIS FORECAST TOWARD THAT CAMP AS THIS ALSO MATCHES UP WELL
WITH EXPECTED EVOLUTION OF THE LLJ AS IT STRENGTHENS UP INTO SW
MN AFTER 00Z AND VEERING INTO IA OVERNIGHT...WITH STORMS DEVELOPING
ON THE NOSE OF THE LLJ AND EDGE OF THE CAPPED EML. THOUGH NOT
EXPECTING WIDESPREAD SEVERE WEATHER...GIVEN STRENGTH OF ELEVATED
INSTABILITY MOVING IN...ALONG WITH EFFECTIVE BULK SHEAR AROUND 40
KTS...COULD CERTAINLY SEE A FEW STRONGER CELLS CAPABLE OF PRODUCING
LARGE HAIL...BUT FOR THE MOST PART...ACTIVITY SHOULD REMAIN SUB
SEVERE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 354 AM CDT THU JUL 24 2014
SCATTERED SHOWERS AND THUNDERSTORMS SHOULD BE IN PROGRESS ACROSS
EASTERN MN AND WESTERN WI FRIDAY MORNING IN AN AXIS OF LOW LEVEL
MOISTURE TRANSPORT...AN APPROACHING MID LEVEL SHORT WAVE AND
COUPLED UPPER LEVEL JET. THE NSSL...SPC AND ARW WRF/S DEPICT THE
SITUATION WELL WITH THE NMM WRF LAGGING A BIT TO THE NW. THE
SHOWERS AND THUNDERSTORMS WILL DIMINISH ACROSS WESTERN WI IN THE
AFTERNOON. MID LEVEL TEMPERATURES WILL BE RISING INTO THE 12-16
DEG C RANGE ACROSS CENTRAL AND SOUTHERN MN DURING THE DAY ON
FRIDAY AND THIS SHOULD AID IN CAPPING ANY FURTHER DEVELOPMENT
ALONG A WEAKENING COOL FRONT ACROSS WESTERN MN. DRY WEATHER IS
THEN EXPECTED OVER MUCH OF THE FA FRIDAY NIGHT AND SATURDAY.
A COMPACT VERTICALLY STACKED LOW PRESSURE SYSTEM REMAINS ON TRACK
TO DROP SOUTHEAST ACROSS THE UPPER MISSISSIPPI VALLEY SATURDAY
NIGHT AND SUNDAY. LAYER MOISTURE AND FORCING IS BEST TO THE NORTH
AND EAST OF THE TWIN CITIES WHERE HIGH CHANCE POPS FOR SHOWERS AND
ISOLATED THUNDERSTORMS CONTINUE. LOW CHANCE POPS ARE IN PLACE
FROM THE TWIN CITIES ON WEST AND SOUTH. AFTER HIGHS ON SATURDAY IN
THE LOWER TO MIDDLE 80S...HIGHS ON SUNDAY WILL DROP INTO THE LOWER
TO MIDDLE 70S.
THE TREND OF COOLER THAN NORMAL TEMPERATURES WILL PERSIST AT LEAST
INTO THE MIDDLE OF NEXT WEEK AS A DEEP UPPER LOW/TROUGH TAKES
SHAPE OVER EASTERN NORTH AMERICA WHILE MASSIVE RIDGING BUILDS IN
THE FAR WEST. HENCE...A NORTHWEST UPPER FLOW WILL PREVAIL ACROSS
THE FA FOR MUCH OF NEXT WEEK. IT LOOKS PRETTY DRY WITH NO POPS
MENTIONED SUNDAY NIGHT THROUGH TUESDAY NIGHT. SMALL CHANCE POPS
BEGIN TO CREEP BACK IN ON WEDNESDAY OVER THE WI CWA AS WELL AS THE
SOUTHWEST CORNER OF MN. HIGHS IN THE LOWER TO MIDDLE 70S ON MONDAY
WILL RISE INTO THE UPPER 70S TO AROUND 80 BY WEDNESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1143 AM CDT THU JUL 24 2014
RADAR TRENDS SUGGEST SCATTERED ACTIVITY TO MOVE INTO WESTERN MN
THIS AFTERNOON. BELIEVE IT WILL HOLD OFF AT KSTC AND EAST THROUGH
MOST OF THE EVENING WITH THE BEST CHANCE MOVING IN AFTER 06Z
ACROSS THE SOUTHEAST PORTION OF THE AREA. WILL BRING IN SOME
THUNDER TO KRWF THIS EVENING WITH PERHAPS A SHRA THIS AFTERNOON
BEFORE 23Z. WILL SPREAD THIS EAST OVERNIGHT...LEAVING ACTIVITY OUT
OF WEST CENTRAL WISCONSIN DOE TO UNCERTAINTY. CAPE BUILDS INTO
FRIDAY AND MAY SEE SOME THREAT OF WIDELY SCATTERED ACTIVITY ALONG
AND EAST OF THE FRONT INTO THE AFTERNOON. APPEARS FROPA WILL ONLY
MAKE IT INTO WESTERN MN DURING THE AFTERNOON...AND EXITING WC
WISCONSIN AFTER 06Z SAT. SOME THREAT OF MVFR CIGS
DEVELOPING LATE TONIGHT...ESPECIALLY IF A MORE WIDESPREAD MCS
DEVELOPS. STILL SOME UNCERTAINTY TO COVERAGE...SO WILL LEAVE VFR
INTO FRIDAY.
KMSP...
WILL CONTINUE TO MENTION PROB30 TSRA IN THE 08Z-12Z PERIOD...PER
MODEL DISCREPANCY IN OVERALL DEVELOPMENT/PLACEMENT DURING THE
NIGHT. TRENDS SHOULD FAVOR SOMETHING DEVELOPING FARTHER EAST AFTER
06Z FRI...LIKE WE HAVE IT AS LLJ AND INSTABILITY GRADIENT SHIFTS
EAST. SOME THREAT OF MVFR CIG INTO FRIDAY MORNING...BUT WILL LEAVE
VFR FOR NOW DUE TO LOW CONFIDENCE. STILL SOME THREAT OF TSRA INTO
FRIDAY AHEAD OF SLOW MOVING FRONT INTO THE AFTERNOON...BUT
BELIEVE IT WILL BE RATHER ISOLD IN NATURE AND WILL LEAVE THIS OUT
FOR NOW. SOUTHEAST TO SOUTH WINDS AHEAD OF FRONT BECOMING WEST
INTO FRIDAY EVENING.
/OUTLOOK FOR KMSP/
FRI...CHC MVFR CIGS/ISOLD TSRA. WINDS SSE AT 5-10KTS.
SAT...VFR. WINDS WSW AT 5-10KTS.
SUN...VFR. CHANCE SHRA/MVFR CIGS. WINDS NW AT 10-15 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...RAH
AVIATION...DWE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
544 AM CDT THU JUL 24 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 354 AM CDT THU JUL 24 2014
STOUT UPPER RIDGE REMAINS CENTERED OVER COLORADO THIS MORNING...WITH
ITS ASSOCIATED RIDGE AXIS EXTENDING UP THROUGH THE CENTRAL DAKOTAS.
THIS RIDGE HAS A VERY WARM EML ASSOCIATED WITH IT /SEE +17C H7 TEMP
ON THE UNR SOUNDING LAST NIGHT/ AS WE CONTINUE TO SEE SHORTWAVES AND
ASSOCIATED STORMS ROTATE AROUND THE PERIPHERY OF THE RIDGE...THE
MOST IMPRESSIVE OF WHICH THIS MORNING IS UP IN NORTH CENTRAL
MONTANA. BY TONIGHT THE RIDGE AXIS WILL SHIFT INTO MN...THOUGH WILL
BE GETTING FLATTENED OUT BY THE H5 LOW CURRENTLY OVER WASHINGTON
THAT WILL MOVE INTO THE CANADIAN PRAIRIES OVERNIGHT.
THIS MORNING...HIGH PRESSURE CENTERED OVER WRN LAKE SUPERIOR HAS A
COOL A DRY AIRMASS IN PLACE THAT WILL LIKELY DELAY THE ARRIVAL OF
PRECIP. HAVE CUT BACK CONSIDERABLY ON POPS THROUGH THE
AFTERNOON...WITH MOST GUIDANCE SHOWING THE DAY GOING BY DRY AS THE
LLJ AND THETA-E RIDGE LOOK TO REMAIN ACROSS THE DAKOTAS THROUGH THE
DAY. THE ONLY THING TO WATCH WILL BE THAT MONTANA WAVE THAT WILL BE
DIVING SE ACROSS NODAK THIS MORNING AS IT WORKS AROUND THE RIDGE.
NMM/ARW WRFS SHOW REMNANTS OF THIS ACTIVITY WORKING ACROSS WRN MN
THIS AFTERNOON...BUT CONSIDERING THE RAP DOES NOT SHOW THE ELEVATED
INSTABILITY MAKING MUCH PROGRESS ACROSS THE DAKOTAS TODAY...FAVORED
THE DRY FORECAST FOR TODAY HIGHLIGHTED BY THE DETERMINISTIC MODELS.
BASICALLY...LEFT SOME SLIGHT CHANCES THROUGH THE AFTERNOON SW OF THE
MN RIVER...CLOSER TO WHERE THE BETTER MOISTURE TRANSPORT INTO SE
SODAK WILL BE. OTHERWISE...FEW CHANGES WERE NEEDED FOR TODAY...WITH
SRLY WINDS BRINGING IN SLIGHTLY WARMER AIR RESULTING IN HIGHS A
COUPLE OF DEGREES WARMER THAN WHAT WE SAW WEDNESDAY.
TONIGHT LOOKS TO BRING OUR BEST CHANCE FOR PRECIP OVER THE NEXT
WEEK. SOME MODEL DISAGREEMENT STILL EXISTS...WITH A COUPLE OF CAMPS
EXISTING WITH THE NAM/GFS/ECMWF CONTINUING TO HIGHLIGHT THE
POTENTIAL FOR WIDESPREAD ELEVATED CONVECTION FROM SOUTH CENTRAL MN
INTO NE IA...WHILE THE GEM AND WRF BASED CAMS SHOW CONSIDERABLY LESS
ACTIVITY IN THE MPX AREA...WITH TWO AREAS OF CONVECTION DEVELOPING
OVERNIGHT DOWN ACROSS IA AND ACROSS CENTRAL/NRN MN. THE FIRST OF THE
SOLUTIONS MAINTAINS GOOD CONTINUITY WITH THE EXISTING FORECAST...SO
FAVORED THIS FORECAST TOWARD THAT CAMP AS THIS ALSO MATCHES UP WELL
WITH EXPECTED EVOLUTION OF THE LLJ AS IT STRENGTHENS UP INTO SW
MN AFTER 00Z AND VEERING INTO IA OVERNIGHT...WITH STORMS DEVELOPING
ON THE NOSE OF THE LLJ AND EDGE OF THE CAPPED EML. THOUGH NOT
EXPECTING WIDESPREAD SEVERE WEATHER...GIVEN STRENGTH OF ELEVATED
INSTABILITY MOVING IN...ALONG WITH EFFECTIVE BULK SHEAR AROUND 40
KTS...COULD CERTAINLY SEE A FEW STRONGER CELLS CAPABLE OF PRODUCING
LARGE HAIL...BUT FOR THE MOST PART...ACTIVITY SHOULD REMAIN SUB
SEVERE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 354 AM CDT THU JUL 24 2014
SCATTERED SHOWERS AND THUNDERSTORMS SHOULD BE IN PROGRESS ACROSS
EASTERN MN AND WESTERN WI FRIDAY MORNING IN AN AXIS OF LOW LEVEL
MOISTURE TRANSPORT...AN APPROACHING MID LEVEL SHORT WAVE AND
COUPLED UPPER LEVEL JET. THE NSSL...SPC AND ARW WRF/S DEPICT THE
SITUATION WELL WITH THE NMM WRF LAGGING A BIT TO THE NW. THE
SHOWERS AND THUNDERSTORMS WILL DIMINISH ACROSS WESTERN WI IN THE
AFTERNOON. MID LEVEL TEMPERATURES WILL BE RISING INTO THE 12-16
DEG C RANGE ACROSS CENTRAL AND SOUTHERN MN DURING THE DAY ON
FRIDAY AND THIS SHOULD AID IN CAPPING ANY FURTHER DEVELOPMENT
ALONG A WEAKENING COOL FRONT ACROSS WESTERN MN. DRY WEATHER IS
THEN EXPECTED OVER MUCH OF THE FA FRIDAY NIGHT AND SATURDAY.
A COMPACT VERTICALLY STACKED LOW PRESSURE SYSTEM REMAINS ON TRACK
TO DROP SOUTHEAST ACROSS THE UPPER MISSISSIPPI VALLEY SATURDAY
NIGHT AND SUNDAY. LAYER MOISTURE AND FORCING IS BEST TO THE NORTH
AND EAST OF THE TWIN CITIES WHERE HIGH CHANCE POPS FOR SHOWERS AND
ISOLATED THUNDERSTORMS CONTINUE. LOW CHANCE POPS ARE IN PLACE
FROM THE TWIN CITIES ON WEST AND SOUTH. AFTER HIGHS ON SATURDAY IN
THE LOWER TO MIDDLE 80S...HIGHS ON SUNDAY WILL DROP INTO THE LOWER
TO MIDDLE 70S.
THE TREND OF COOLER THAN NORMAL TEMPERATURES WILL PERSIST AT LEAST
INTO THE MIDDLE OF NEXT WEEK AS A DEEP UPPER LOW/TROUGH TAKES
SHAPE OVER EASTERN NORTH AMERICA WHILE MASSIVE RIDGING BUILDS IN
THE FAR WEST. HENCE...A NORTHWEST UPPER FLOW WILL PREVAIL ACROSS
THE FA FOR MUCH OF NEXT WEEK. IT LOOKS PRETTY DRY WITH NO POPS
MENTIONED SUNDAY NIGHT THROUGH TUESDAY NIGHT. SMALL CHANCE POPS
BEGIN TO CREEP BACK IN ON WEDNESDAY OVER THE WI CWA AS WELL AS THE
SOUTHWEST CORNER OF MN. HIGHS IN THE LOWER TO MIDDLE 70S ON MONDAY
WILL RISE INTO THE UPPER 70S TO AROUND 80 BY WEDNESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 519 AM CDT THU JUL 24 2014
7K FOOT CIGS HAVE THWARTED THE FOG OVER WI THIS MORNING...SO
STARTING OFF ALL TERMINALS VFR. 6Z HOPWRF MEMBERS PICKED UP ON
DEVELOPING LINE OF STORMS OVER CENTRAL SODAK QUITE WELL...AND
BELIEVE THEIR EVOLUTION FOR THESE STORMS THIS MORNING...WHICH IS
TO DIMINISH THEM BEFORE THEY REACH MN...AS MOISTURE TRANSPORT AND
INSTABILITY DO NOT REALLY START TO SHOW UP IN MN UNTIL THIS
EVENING. FOLLOWED THE IDEA OF THE NAM/ECMWF FOR SHRA/TSRA
POTENTIAL TONIGHT...WHICH WILL BE GREATEST FROM RWF TO MSP AND
POINTS SOUTH. ENOUGH MODEL SPREAD EXISTS THOUGH TO KEEP ANY TSRA
MENTION TO A PROB30 AT THIS POINT. OTHER THAN THE LOWER CONFIDENCE
IN THE PRECIP POTENTIAL...CONFIDENCE IS HIGH IN REST OF THE TAF
COMPONENTS.
KMSP...WITH THE 6Z NAM LOOKING MUCH LIKE ITS 00Z COUNTERPART AND
THE 00Z ECMWF...RETAINED PROB30 TSRA MENTION BETWEEN 7Z AND 11Z.
AT THIS POINT...CONFIDENCE IN PRECIP POTENTIAL/TIMING NOT HIGH
ENOUGH TO GO WITH ANYTHING HIGHER THAN THE PROB30. FRIDAY
MORNING...THE GFS/NAM ARE HINTING AT THE POTENTIAL FOR MVFR CIGS
SO BROUGHT IN A SCT020 TO HINT AT THAT THREAT FOR NOW. OUTSIDE OF
THAT...VFR CONDS WILL PREVAIL WITH SSE WINDS INCREASING THIS
MORNING AND REMAINING FAIRLY PERSISTENT AROUND 10 KTS THROUGH THE
NIGHT.
/OUTLOOK FOR KMSP/
FRI...CHC MVFR CIGS. WINDS SSE AT 5-10KTS.
SAT...VFR. WINDS WSW AT 5-10KTS.
SUN...VFR. CHANCE SHRA/MVFR CIGS. WINDS NW AT 10-15 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...RAH
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
354 AM CDT THU JUL 24 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 354 AM CDT THU JUL 24 2014
STOUT UPPER RIDGE REMAINS CENTERED OVER COLORADO THIS MORNING...WITH
ITS ASSOCIATED RIDGE AXIS EXTENDING UP THROUGH THE CENTRAL DAKOTAS.
THIS RIDGE HAS A VERY WARM EML ASSOCIATED WITH IT /SEE +17C H7 TEMP
ON THE UNR SOUNDING LAST NIGHT/ AS WE CONTINUE TO SEE SHORTWAVES AND
ASSOCIATED STORMS ROTATE AROUND THE PERIPHERY OF THE RIDGE...THE
MOST IMPRESSIVE OF WHICH THIS MORNING IS UP IN NORTH CENTRAL
MONTANA. BY TONIGHT THE RIDGE AXIS WILL SHIFT INTO MN...THOUGH WILL
BE GETTING FLATTENED OUT BY THE H5 LOW CURRENTLY OVER WASHINGTON
THAT WILL MOVE INTO THE CANADIAN PRAIRIES OVERNIGHT.
THIS MORNING...HIGH PRESSURE CENTERED OVER WRN LAKE SUPERIOR HAS A
COOL A DRY AIRMASS IN PLACE THAT WILL LIKELY DELAY THE ARRIVAL OF
PRECIP. HAVE CUT BACK CONSIDERABLY ON POPS THROUGH THE
AFTERNOON...WITH MOST GUIDANCE SHOWING THE DAY GOING BY DRY AS THE
LLJ AND THETA-E RIDGE LOOK TO REMAIN ACROSS THE DAKOTAS THROUGH THE
DAY. THE ONLY THING TO WATCH WILL BE THAT MONTANA WAVE THAT WILL BE
DIVING SE ACROSS NODAK THIS MORNING AS IT WORKS AROUND THE RIDGE.
NMM/ARW WRFS SHOW REMNANTS OF THIS ACTIVITY WORKING ACROSS WRN MN
THIS AFTERNOON...BUT CONSIDERING THE RAP DOES NOT SHOW THE ELEVATED
INSTABILITY MAKING MUCH PROGRESS ACROSS THE DAKOTAS TODAY...FAVORED
THE DRY FORECAST FOR TODAY HIGHLIGHTED BY THE DETERMINISTIC MODELS.
BASICALLY...LEFT SOME SLIGHT CHANCES THROUGH THE AFTERNOON SW OF THE
MN RIVER...CLOSER TO WHERE THE BETTER MOISTURE TRANSPORT INTO SE
SODAK WILL BE. OTHERWISE...FEW CHANGES WERE NEEDED FOR TODAY...WITH
SRLY WINDS BRINGING IN SLIGHTLY WARMER AIR RESULTING IN HIGHS A
COUPLE OF DEGREES WARMER THAN WHAT WE SAW WEDNESDAY.
TONIGHT LOOKS TO BRING OUR BEST CHANCE FOR PRECIP OVER THE NEXT
WEEK. SOME MODEL DISAGREEMENT STILL EXISTS...WITH A COUPLE OF CAMPS
EXISTING WITH THE NAM/GFS/ECMWF CONTINUING TO HIGHLIGHT THE
POTENTIAL FOR WIDESPREAD ELEVATED CONVECTION FROM SOUTH CENTRAL MN
INTO NE IA...WHILE THE GEM AND WRF BASED CAMS SHOW CONSIDERABLY LESS
ACTIVITY IN THE MPX AREA...WITH TWO AREAS OF CONVECTION DEVELOPING
OVERNIGHT DOWN ACROSS IA AND ACROSS CENTRAL/NRN MN. THE FIRST OF THE
SOLUTIONS MAINTAINS GOOD CONTINUITY WITH THE EXISTING FORECAST...SO
FAVORED THIS FORECAST TOWARD THAT CAMP AS THIS ALSO MATCHES UP WELL
WITH EXPECTED EVOLUTION OF THE LLJ AS IT STRENGTHENS UP INTO SW
MN AFTER 00Z AND VEERING INTO IA OVERNIGHT...WITH STORMS DEVELOPING
ON THE NOSE OF THE LLJ AND EDGE OF THE CAPPED EML. THOUGH NOT
EXPECTING WIDESPREAD SEVERE WEATHER...GIVEN STRENGTH OF ELEVATED
INSTABILITY MOVING IN...ALONG WITH EFFECTIVE BULK SHEAR AROUND 40
KTS...COULD CERTAINLY SEE A FEW STRONGER CELLS CAPABLE OF PRODUCING
LARGE HAIL...BUT FOR THE MOST PART...ACTIVITY SHOULD REMAIN SUB
SEVERE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 354 AM CDT THU JUL 24 2014
SCATTERED SHOWERS AND THUNDERSTORMS SHOULD BE IN PROGRESS ACROSS
EASTERN MN AND WESTERN WI FRIDAY MORNING IN AN AXIS OF LOW LEVEL
MOISTURE TRANSPORT...AN APPROACHING MID LEVEL SHORT WAVE AND
COUPLED UPPER LEVEL JET. THE NSSL...SPC AND ARW WRF/S DEPICT THE
SITUATION WELL WITH THE NMM WRF LAGGING A BIT TO THE NW. THE
SHOWERS AND THUNDERSTORMS WILL DIMINISH ACROSS WESTERN WI IN THE
AFTERNOON. MID LEVEL TEMPERATURES WILL BE RISING INTO THE 12-16
DEG C RANGE ACROSS CENTRAL AND SOUTHERN MN DURING THE DAY ON
FRIDAY AND THIS SHOULD AID IN CAPPING ANY FURTHER DEVELOPMENT
ALONG A WEAKENING COOL FRONT ACROSS WESTERN MN. DRY WEATHER IS
THEN EXPECTED OVER MUCH OF THE FA FRIDAY NIGHT AND SATURDAY.
A COMPACT VERTICALLY STACKED LOW PRESSURE SYSTEM REMAINS ON TRACK
TO DROP SOUTHEAST ACROSS THE UPPER MISSISSIPPI VALLEY SATURDAY
NIGHT AND SUNDAY. LAYER MOISTURE AND FORCING IS BEST TO THE NORTH
AND EAST OF THE TWIN CITIES WHERE HIGH CHANCE POPS FOR SHOWERS AND
ISOLATED THUNDERSTORMS CONTINUE. LOW CHANCE POPS ARE IN PLACE
FROM THE TWIN CITIES ON WEST AND SOUTH. AFTER HIGHS ON SATURDAY IN
THE LOWER TO MIDDLE 80S...HIGHS ON SUNDAY WILL DROP INTO THE LOWER
TO MIDDLE 70S.
THE TREND OF COOLER THAN NORMAL TEMPERATURES WILL PERSIST AT LEAST
INTO THE MIDDLE OF NEXT WEEK AS A DEEP UPPER LOW/TROUGH TAKES
SHAPE OVER EASTERN NORTH AMERICA WHILE MASSIVE RIDGING BUILDS IN
THE FAR WEST. HENCE...A NORTHWEST UPPER FLOW WILL PREVAIL ACROSS
THE FA FOR MUCH OF NEXT WEEK. IT LOOKS PRETTY DRY WITH NO POPS
MENTIONED SUNDAY NIGHT THROUGH TUESDAY NIGHT. SMALL CHANCE POPS
BEGIN TO CREEP BACK IN ON WEDNESDAY OVER THE WI CWA AS WELL AS THE
SOUTHWEST CORNER OF MN. HIGHS IN THE LOWER TO MIDDLE 70S ON MONDAY
WILL RISE INTO THE UPPER 70S TO AROUND 80 BY WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1141 PM CDT WED JUL 23 2014
FEW PROBLEMS EXPECTED IN THE NEAR TERM AS HIGH PRESSURE MAINTAINS
CONTROL OF THE WEATHER ACROSS THE UPPER MIDWEST THROUGH THE
MORNING HOURS. THE ONLY ISSUE MAY BE FOG DEVELOPMENT IN THE PRONE
AREAS ESPECIALLY TO THE EAST WHERE WINDS WILL BE LIGHTER TOWARD
DAYBREAK. OTHERWISE...SHOWERS WILL BE APPROACHING WESTERN
MINNESOTA IN THE MORNING AFTER A STRONG LLJ DEVELOPS OVERNIGHT
ACROSS THE DAKOTAS. STILL EXPECT THESE SHOWERS TO BE DIMINISHING
SO NOT CONFIDENT IN ACTUALLY SEEING RAIN AT A SPECIFIC LOCATION
SUCH AS RWF...SO REMOVED THE CHANCE THERE. THEN...A MORE ROBUST
CHANCE OF PRECIPITATION COMES LATE THURSDAY NIGHT WHICH IS
INDICATED AT MSP AND RWF. MSP MAINLY BECAUSE OF THE EXTRA 6 HOUR
WINDOW. LIGHT WINDS TONIGHT WILL CONTINUE TURNING EAST AND NEARLY
SOUTH THROUGH TOMORROW.
KMSP...MAIN FOCUS WILL BE THE THUNDERSTORMS EXPECTED IN THE
OVERNIGHT PERIOD THURSDAY INTO FRIDAY. OTHERWISE VFR CONDITIONS
EXPECTED WITH LITTLE CHANGES FROM THE PREVIOUS FORECAST.
/OUTLOOK FOR KMSP/
THU NIGHT...VFR. CHANCE MVFR CONDS W/ TSRA OVERNIGHT. WINDS SE AT
10KTS.
FRI...VFR. CHANCE TSRA. WINDS SSE AT 5-10KTS.
SAT...VFR. WINDS W AT 10KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...RAH
AVIATION...SPD
AREA FORECAST DISCUSSION
NWS HASTINGS NE
338 PM CDT THU JUL 24 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 332 PM CDT THU JUL 24 2014
FAIRLY QUIET DAY WITH MOSTLY SUNNY SKIES AS THE UPPER LEVEL RIDGE
AXIS CONTINUES TO MOVE OVERHEAD. 12Z SUBJECTIVE UPPER AIR ANALYSIS
IN ADDITION TO RAP ANALYSIS SHOWS A STOUT MID LEVEL WARM POCKET OVER
THE HIGH PLAINS REGION. THIS CONTINUES TO DRIFT EWD WHICH WOULD
TYPICALLY CAP OFF ANY POTENTIAL THUNDERSTORM DEVELOPMENT. THIS BEING
SAID...AN AREA OF CONVECTION HAS MANAGED TO DEVELOP OVER THE
NEBRASKA PANHANDLE AND PORTIONS OF NORTHEAST COLORADO IN ADVANCE OF
A WEAK VORT MAX. LATEST RUNS OF THE HRRR AND RAP INDICATE THIS
CONVECTION HOLDING ON AND SPREADING EAST THROUGHOUT THE LATER
EVENING HOURS. AS A RESULT...WILL HOLD ONTO SMALL POPS ACROSS THE
NORTHERN CWA.
ATTENTION THEN TURNS TO HEAT TOMORROW. HIGHS SHOULD REACH THE 100
DEGREE MARK ACROSS THE KANSAS COUNTIES WITH UPPER 90S SOUTH OF
INTERSTATE 80. COMBINED WITH SFC DEWPOINTS IN THE UPPER 60S...WE
SHOULD APPROACH HEAT INDICES IN THE 105+ RANGE. AS A RESULT...WILL
GO AHEAD AND ISSUE A HEAT ADVISORY FOR PORTIONS OF SOUTH CENTRAL
NEBRASKA AND ALL THE NORTH CENTRAL KANSAS COUNTIES.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 332 PM CDT THU JUL 24 2014
ANOTHER HOT DAY IS EXPECTED ON SATURDAY WITH POTENTIAL FOR HEAT
ADVISORY CRITERIA AGAIN. WILL LET LATER SHIFTS EVALUATE FOR
ADDITIONAL HEADLINES. A COLD FRONT WILL DROP OVER THE AREA SATURDAY
NIGHT WITH HIGH PRESSURE BUILDING ACROSS THE AREA SUNDAY INTO
MONDAY. MUCH COOLER AND DRIER AIRMASS WILL ALLOW TEMPS TO DROP INTO
THE LOW 80S FOR HIGHS AND LOW 60S FOR LOWS.
RETURN FLOW WILL SET UP EARLY NEXT WEEK WHILE A SERIES OF UPPER
LEVEL SHORTWAVES ARE FORECAST TO PASS THROUGH THE REGION IN
MID/UPPER LEVEL NORTHWESTERLY FLOW. MODEL CONSENSUS HAS PUT AT LEAST
A SLIGHT CHANCE OR CHANCE OF TSTMS FROM MONDAY NIGHT THROUGH
THURSDAY. ALTHOUGH WIDESPREAD CONTINUOUS PCPN IS NOT
ANTICIPATED...WILL LEAVE THESE CHANCES IN DUE TO UNCERTAINTY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1238 PM CDT THU JUL 24 2014
VFR CONDITIONS EXPECTED THRU THE FCST PD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...HEAT ADVISORY FROM NOON TO 7 PM CDT FRIDAY FOR NEZ063-064-
074>077-083>087.
KS...HEAT ADVISORY FROM NOON TO 7 PM CDT FRIDAY FOR KSZ005>007-
017>019.
&&
$$
SHORT TERM...KERN
LONG TERM...KERN
AVIATION...DEE
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
240 PM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY AND PUSH
INTO THE AREA TONIGHT...THEN STALL ACROSS SOUTHERN AREAS FRIDAY
AND FINALLY DISSIPATE SATURDAY. ANOTHER COLD FRONT WILL APPROACH
THE AREA EARLY NEXT WEEK...PUSHING THROUGH THE AREA TUESDAY. HIGH
PRESSURE WILL BUILD INTO THE AREA WEDNESDAY AND THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 225 PM THURS...A FEW SEVERE THUNDERSTORM WARNINGS WERE
ISSUED EARLIER THIS AFTERNOON FOR THE COASTAL PLAIN COUNTIES BUT
THE LINK HAS SINCE SHIFTED SOUTH AND WEAKENED. THE LINE OF STORMS
CURRENTLY STRETCHES FROM THE CENTRAL OBX WEST TO SOUTH OF NEW BERN
WEST TO NEAR KENANSVILLE. FREQUENT LIGHTNING...GUSTY WINDS...AND
HEAVY RAIN CAN BE EXPECTED WITH THESE STORMS. THE ENVIRONMENT WAS
MORE CONDUCIVE FOR SEVERE STORMS EARLIER BUT LATEST SPC MESOANALYSES
INDICATE EFFECTIVE BULK SHEAR OF 30 KT OVER SOUTHERN PORTIONS AND
45 KT FARTHER INLAND WHERE THE ATMOSPHERE HAS ALREADY BEEN WORKED
OVER. MULTI MODEL SOUNDING ANALYSES INDICATE A MODERATELY
UNSTABLE AIRMASS THIS AFTERNOON WITH LIFTED INDICES -6 TO -8
C...SBCAPE VALUES 2000-2500 J/KG...AND ABUNDANT MOISTURE WITH
PWATS ABOVE 2 INCHES. BIGGEST THREAT REMAINS DAMAGING WIND GUSTS.
CANNOT COMPLETELY RULE OUT HAIL AS WELL THIS AFTERNOON BUT VERY
HIGH FREEZING LEVELS ON THE ORDER OF 14750-15250 FEET WOULD ARGUE
AGAINST MUCH WIDESPREAD HAIL THREAT.
BERMUDA HIGH PRESSURE CONTINUES TO RIDGE INTO THE SOUTHEAST WITH A
TROUGH OF LOW PRESSURE ACROSS THE PIEDMONT. AN UPPER TROUGH
AND ATTENDANT SFC COLD FRONT ARE PUSHING ACROSS THE MID ATLANTIC
AND CENTRAL APPALACHIANS. THE FRONT...PIEDMONT TROUGH AND
SEABREEZE HAVE ALL BEEN TRIGGERS FOR CONVECTION THIS AFTERNOON BUT
EXPECT SHOWERS/STORMS TO WANE FOR INLAND/NW ZONES THAT HAVE BEEN
WORKED OVER. 16Z HRRR SUGGESTS MORE SHOWERS/STORMS TO DEVELOP
ALONG THE FRONT AND IMPACT THE AREA FROM NW TO SE THIS EVENING
INTO THE OVERNIGHT HOURS AS THE FRONT MOVES SE THROUGH THE AREA.
HAVE TRENDED POPS SIMILAR TO THE HRRR. TEMPS OVERNIGHT WILL BE
MILD WITH LOWS IN THE LOW 70S INLAND TO MID 70S ALONG THE COAST
AND OBX. CANNOT RULE OUT PATCHY FOG INLAND FOR AREAS THAT OBSERVED
HEAVY RAIN THIS AFTERNOON.
&&
.SHORT TERM /FRIDAY/...
AS OF 235 PM THURS...THE FRONT WILL STALL ACROSS THE SOUTHERN COASTAL
WATERS FRI WITH A SURFACE RIDGE OVER THE MID-ATLANTIC STATES BUILDING
SOUTH OVER THE AREA DURING THE DAY. WINDS WILL SHIFT NE THEN E BY
LATE IN THE DAY. ONLY ISOLATED SHOWERS OR THUNDERSTORMS WILL BE
POSSIBLE TOMORROW BUT BEST FOCUS FOR STORMS AND UPPER SUPPORT
REMAIN OFF THE NC COAST AND SOUTH OF THE MHX CWA. LOW LEVEL THICKNESSES
FALL ROUGHLY 20 METERS FRI ALLOWING MAX TEMPS TO BUILD INTO THE
MID/UPPER 80S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
AS OF 215 PM WED...FRI NIGHT THRU EARLY SUNDAY LOOKS MAINLY DRY AS
UPR TROF LIFTS OUT WITH ZONAL FLOW ALOFT. CONT ISOLD POPS FOR CSTL
WTRS FRI NIGHT AND INLAND SXNS SAT. MDLS AGREE NOW THAT SUN SHLD
REMAIN MAINLY DRY AS DEEPER MOISTURE REMAINS TO THE NW SO LOWERED
POPS TO SLIGHT INLAND. BEST CHC OF RAIN LOOKS TO BE MON AFTN AND
EVENING AS RATHER STRONG FRONT FOR LATE JULY PUSHES THRU THE
REGION...CONT CHC POPS. FRONT PUSHES OFFSHORE AND STALLS MID WEEK
WITH DRIER AIR OVER THE REGION AND MAINLY DRY WX EXPECTED. MOISTURE
BEGINS TO INCREASE THU SO INCREASED POPS TO CHC. HIGHS WILL BE IN THE
UPR 80S TO LOWER 90S INLAND SAT THEN 90 TO 95 SUN AND MON WITH GOOD
LOW LVL SW FLOW AHEAD OF THE APPROACHING COLD FRONT. FRONT WILL PUSH
OF THE CST TUE AND STALL OFFSHORE WED AND THU WITH HIGHS MAINLY IN
THE LOW TO MID 80S.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
SHORT TERM /TONIGHT THROUGH FRIDAY/...
AS OF 215 PM THURS...STRONG LINE OF CONVECTION ACROSS EASTERN NC WILL
AFFECT MAINLY TERMINALS EWN AND OAJ OVER THE NEXT FEW HOURS.
HOWEVER...THREAT OF CONVECTION WILL CONTINUE THROUGH EARLY EVENING
ALONG AND AHEAD OF COLD FRONT. THE FRONT WILL PUSH OFF THE SOUTH
COAST AFTER MIDNIGHT. FORECAST SOUNDINGS AND TIME SECTIONS INDICATE
BKN-OVC MID DECK WILL PERSIST OVERNIGHT SO AM NOT FORECASTING DENSE
FOG... WILL LEAVE IT AT MVFR. MID CLOUD WILL CONTINUE INTO FRIDAY
MORNING WITH A LIGHT NORTHEAST WIND. SHOWERS POSSIBLE OVERNIGHT INTO
FRIDAY BUT ONLY ISOLATED SO DID NOT PUT IN A MENTION IN THE FORECAST.
LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 215 PM THURSDAY...MAINLY VFR CONDS EXPECTED FRI NIGHT THRU SUNDAY
WITH LIMITED PRECIP. HOWEVER...LIGHT WINDS AND AMPLE LOW LEVEL
MOISTURE FRI NIGHT AND SAT NIGHT COULD RESULT IN PATCHY FOG AND ST
WITH REDUCED CIGS/VSBYS. SHRA AND TSRA WILL INCREASE IN CVRG MON AND
MON EVENING ALONG AND AHEAD OF COLD FRONT WITH SOME BRIEF PDS OF
REDUCED FLIGHT CATEGORIES. THE FRONT SHLD PUSH E OF TAF SITES TUE
WITH VFR EXPECTED.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 240 PM THURS...LATEST SURFACE AND BUOY DATA INDICATE WSW/SW
WINDS 10-20 KT WITH SEAS 2-4 FT FOR THE SOUTHERN WATERS. WINDS FOR
THE CENTRAL AND NORTHERN WATERS HAVE BEEN ALTERED DUE TO A LINE OF
STRONG THUNDERSTORMS MOVING FROM NW TO SE THROUGH THE WATERS.
NORTH OF THIS LINE...WINDS HAVE SHIFTED NW AND HAVE GUSTED UPWARDS
OF 30 KNOTS AT TIMES. SEAS REMAIN 2-3 FT FOR THE NORTHERN WATERS.
A COLD FRONT WILL APPROACH FROM THE NW TONIGHT AND CROSS INTO THE
WATERS AFTER MIDNIGHT...AND EVENTUALLY OFF THE SOUTHERN COAST ON
FRI. WINDS WILL SHIFT N THEN NE BEHIND THE FRONT TONIGHT INTO FRI
AS HIGH PRESSURE OVER THE MID-ATLANTIC STATES BUILDS SOUTH INTO
THE REGION. SEAS WILL REMAIN 2-4 FT THROUGH THE SHORT TERM.
LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/
AS OF 210 PM THURS...STATIONARY FRONT S OF THE WATERS WASHES OUT
FRI NIGHT AND SAT WITH LIGHT AND VARIABLE WINDS EXPECTED FRI NIGHT
BECOMING SSW 10 TO 15 KTS LATER SAT. PRES GRAD TIGHTENS SUN AND
MON AS COLD FRONT APPROACHES WITH WINDS INCRG TO 15 TO 20 KTS SUN
AFTN AND 20 TO 25 KTS LATE SUNDAY NIGHT CONTG THRU MON EVENING. AS
FRONT PUSHES OFF THE CST LATER MON NIGHT AND TUE WINDS WILL BECOME
NW TO N BELOW 15 KT.
SEAS 2 TO 3 FEET FRI EVENING THRU MOST OF SAT. SEAS WILL BUILD TO 2
TO 4 FT SAT NIGHT AND REACH 4 TO 5 FT OUTER WTRS SUN AFTN. SEAS WILL
PEAK AT 5 TO 7 FT LATER SUN NIGHT THRU MON EVENING. AS WINDS SHIFT
TO NW AND N BEHIND FRONT SEAS WILL SUBSIDE TO 3 TO 5 FT LATE MON
NIGHT AND EARLY TUE...WITH 2 TO 4 FT BY TUE AFTN.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DAG
NEAR TERM...DAG
SHORT TERM...DAG
LONG TERM...RF
AVIATION...RF/HSA
MARINE...RF/DAG
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1246 PM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY...BRINGING AN
INCREASING RISK FOR STRONG THUNDERSTORMS LATE THIS AFTERNOON INTO
TONIGHT. THIS FRONT WILL STALL ACROSS THE AREA FRIDAY BEFORE
DISSIPATING ON SATURDAY. HIGH PRESSURE WILL BRING HOT AND HUMID
CONDITIONS SUNDAY AND MONDAY. A STRONG COLD FRONT WILL CROSS THE
AREA EARLY TUESDAY...BRINGING COOLER AND DRIER CONDITIONS FOR THE
MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM THURSDAY...OUR CUMULUS FIELD CONTINUE TO GROW AND
VISIBLE SATELLITE SUGGESTS TOWERING CUMULUS AND CB`S ARE DEVELOPING
ACROSS THE NORTHERN PIEDMONT AND SANDHILLS REGION OF SOUTH CAROLINA.
THIS AND AREAS DOWNSTREAM ACROSS BENNETTSVILLE...LUMBERTON AND
ELIZABETHTOWN WILL PROBABLY BE THE FIRST TO EXPERIENCE SCATTERED
THUNDERSTORMS IN THE NEXT 60-90 MINUTES. VIRTUALLY ALL MODEL
GUIDANCE (BOTH SYNOPTIC-SCALE AND MESOSCALE) INDICATES IT WILL TAKE
UNTIL LATE AFTERNOON OR EARLY EVENING FOR STORMS TO SPREAD DOWN TO
THE COAST...SO I HAVE TRIMMED BACK POPS THROUGH 21Z/5 PM INTO THE
CHANCE (30-50% RANGE) WITH THE CONTINUED EXPECTATION OF MORE
SUBSTANTIAL COVERAGE AFTER 5 PM. PREVIOUS DISCUSSION FROM 1015 AM
FOLLOWS...
CLEAR SKIES OVER THE AREA THIS MORNING SHOULD TURN PARTLY CLOUDY
OVER THE NEXT FEW HOURS. TEMPERATURES ARE SOARING QUICKLY WITH MID
TO UPPER 80S ALREADY OBSERVED. THE LATEST FEW HRRR RUNS PLUS THE 00Z
NSSL WRF ARE SHOWING A LATER CONVECTIVE INITIATION TIME THAN OUR
PREVIOUS FORECAST INDICATED...SO I HAVE SHIFTED THE WINDOW OF
HIGHEST FORECAST POPS INTO THE 4 PM TO 10 PM RANGE. THIS ALSO IS
WHEN WE COME UNDER THE BEST INFLUENCE OF THE RIGHT-ENTRANCE REGION
OF A HEALTHY 300 MB JET EXTENDING FROM THE MID-ATLANTIC INTO THE
CANADIAN MARITIMES. NO OTHER SIGNIFICANT CHANGES ARE NEEDED...AND
FORECAST TEMPERATURES/DEWPOINTS STILL SUPPORT HEAT INDICES IN THE
100-104 RANGE THIS AFTERNOON. PREVIOUS DISCUSSION FROM 600 AM
FOLLOWS...
A QUICK MOVING MID-LEVEL SHORTWAVE MOVED ACROSS THE UPSTATE OF SOUTH
CAROLINA DURING THE LATE NIGHT AND WAS CURRENTLY MOVING NE ACROSS
CENTRAL NORTH CAROLINA. A FEW SHOWERS AND THUNDERSTORMS DEVELOPED IN
RESPONSE TO THIS ADDED LIFT AND ARE EXPECTED TO PASS BY TO OUR NORTH
THROUGH 9 AM. A WEAKER SECONDARY IMPULSE WAS MOVING NE ACROSS THE
EASTERN CAROLINAS...BUT CONVECTION HAS NOT DEVELOPED IN RESPONSE TO
THIS FEATURE.
A COLD FRONT WILL DROP INTO THE LEE SIDE TROUGH POSITION TODAY
AND THE FRONT WILL THEN SLIDE ACROSS THE FORECAST AREA TONIGHT...
LIKELY LYING ACROSS SOUTHERN AND EASTERN PORTIONS OF THE FORECAST
AREA AT DAYBREAK FRI. THE UPPER TROUGH WILL STILL BE UPSTREAM FRI
MORNING.
THE ATMOSPHERE WILL BE WARM AND MOIST THROUGH A DEEP LAYER WITH
PRECIPITABLE WATER VALUES INCREASING THROUGH THE AFTERNOON/EVE...
IN EXCESS OF 2 INCHES...AND ALONG THE COAST...ABOVE 2.25 INCHES.
TEMPERATURES ARE EXPECTED TO REACH THE LOWER TO MID 90S TODAY. THIS
WILL BRING MIXED LAYER CAPE VALUES IN THE NEIGHBORHOOD OF 2000-2500
J/KG. MID LEVEL LAPSE RATES AND SHEAR VALUES ARE UNIMPRESSIVE...BUT
MID-LEVEL WINDS WILL BE ON THE ORDER OF 40 KT. THE BIGGEST RISK WITH
THUNDERSTORMS TODAY AND TONIGHT WILL BE FREQUENT LIGHTNING AND HEAVY
RAIN...ALTHOUGH STORM MOTIONS ARE MUCH HIGHER THAN EARLIER IN THE
WEEK WHICH SHOULD LIMIT THE EXCESSIVE RAINFALL THREAT. HOWEVER...THE
DEEPEST CONVECTION WILL BE CAPABLE OF STRONG WIND GUSTS AND AN
ISOLATED WET MICROBURST WITH DAMAGING WINDS CAN NOT BE RULED OUT.
THUNDERSTORMS MAY DEVELOP ALONG THE COAST AS A RATHER SHARP
SEABREEZE BOUNDARY DEVELOPS LATER THIS MORNING/MIDDAY. ELSEWHERE...
AFTERNOON THUNDERSTORMS WILL POP AS THE CONVECTIVE TEMPS ARE
EXCEEDED. THE CONVECTION SHOULD TEND TO BECOME MORE ORGANIZED MID
AND LATE AFTERNOON AS IT MOVES TOWARD THE COAST. WE EXPECT
CONVECTION TO LAST WELL INTO THE NIGHT IF NOT THROUGH THE NIGHT AS A
MODEST SHORTWAVE ALOFT INTERACTS WITH THE SURFACE FRONT.
HEAT INDEX VALUES LATE MORNING AND THIS AFTERNOON WILL REACH 100
DEGREES IN MOST AREAS AND AS HIGH AS 104 DEGREES. OF COURSE...ONCE A
STRONG THUNDERSTORM MOVES OVERHEAD...THE HEAT WILL GET KNOCKED
DOWN...BUT NOT THE HUMIDITY.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...COLD FRONT STALLED ACROSS THE AREA WILL
CONTINUE SHOWER AND THUNDERSTORM CHANCES ON FRIDAY...BUT AT THE SAME
TIME DRIER AIR WILL BEGIN TO ADVECT IN FROM THE WEST...DRYING OUT
THE MID AND UPR PORTIONS OF THE COLUMN. STILL...WITH THE FRONT IN
PLACE...TEMPS RISING TO AROUND 90...AND DEWPOINTS IN THE LOW
70S...THERE WILL BE PLENTY OF FUEL AROUND FOR CONVECTION BEFORE THE
DRIER AIR WORKS INTO THE CWA. THUS WILL CARRY CHC POP
FRIDAY...HIGHEST ACROSS THE EASTERN PORTIONS OF THE CWA. THE DIURNAL
TREND FOR CONVECTION MAY BE A BIT ATYPICAL AS THE DRY AIR INTRUDES
OVERHEAD...AND THE HIGHEST COVERAGE OF CONVECTION MAY BE LATE
MORNING/EARLY AFTN BEFORE TAPERING OFF INTO THE EVE. THIS FRONT WILL
WASH OUT FRIDAY NIGHT LEAVING MOSTLY CLEAR SKY CONDITIONS...BUT AS
LIGHT SW FLOW RE-DEVELOPS...MINS WILL FALL ONLY INTO THE MID 70S AT
THE COAST...AND TO AROUND 70 INLAND.
ANY AIRMASS CHANGE ASSOCIATED WITH THE PRIOR FRONT QUICKLY ERODES
SATURDAY...LEAVING A HOT DAY ACROSS THE CWA. FORTUNATELY...THE
COLUMN WILL BE DRIER...AND THUS HUMIDITY VALUES WILL BE MUCH
LOWER...KEEPING APPARENT TEMPS TO BELOW 100 EVEN AS HIGHS CLIMB TO
AROUND 90 AT THE COAST...MID 90S WELL INLAND. WILL CONTINUE WITH THE
INHERITED SCHC POP ON SATURDAY SIMPLY DUE TO THE HEAT...BUT ONLY
ISOLATED STORMS ARE POSSIBLE AS PWATS DROP TO LESS THAN 1.5 INCHES.
INCREASING SW RETURN FLOW SATURDAY NIGHT WILL PREVENT SIGNIFICANT
COOLING...AND THUS LOWS SAT NIGHT WILL BE WELL ABOVE NORMAL...UPR
70S AT THE BEACHES TO LOW 70S ONLY WELL INLAND.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...A HOT START TO THE PERIOD...BUT IT WILL BE
SHORT LIVED AS...ONCE AGAIN...AN ANOMALOUSLY STRONG UPPER TROUGH
DIVES ACROSS THE EASTERN CONUS.
SUNDAY LOOKS TO BE THE HOTTEST DAY OF THE PERIOD AS SUBTLE MID-LEVEL
RIDGING AND STRONG SW RETURN FLOW AROUND A RIDGE OF HIGH PRESSURE
PUSH TEMPS INTO THE MID AND MAYBE UPR 90S...AND WE MAY EXPERIENCE
OUR FIRST HEAT ADVISORY OF 2014 (HEAT INDEX OF 105 OR GREATER).
ALTHOUGH HUMIDITY WILL INCREASE ON SUNDAY AS WELL...CONVECTIVE
COVERAGE MAY BE QUITE LIMITED DUE TO SOME MID-LEVEL DRY AIR
PERSISTING...AND A LID WITHIN A LOW-LEVEL THERMAL RIDGE. MONDAY WILL
BE SIMILAR...ALTHOUGH A DEGREE OR 2 COOLER AS CLOUD COVER INCREASES
AND MID-LEVEL HEIGHTS DECREASE AHEAD OF AN ADVANCING COLD FRONT.
INCREASING POP IS WARRANTED MONDAY AS WELL...WITH THE BEST CHANCE
OCCURRING MONDAY NIGHT AS THE COLD FRONT MOVES INTO THE AREA. LOWS
BOTH NIGHTS WILL BE ABOVE NORMAL IN MID AND UPR 70S.
BIG AIR MASS CHANGE OCCURS THEREAFTER AS -3 SD TROUGH DROPS INTO
THE MIDWEST...DRIVING A STRONG COLD FRONT INTO THE CWA AND OFFSHORE
DURING TUESDAY. THIS TROUGH WILL PRODUCE LOWERED HEIGHTS ALL THE WAY
INTO THE GULF OF MEXICO THROUGH THE MIDDLE OF NEXT WEEK...BUT
FORTUNATELY FOR THE AREA THE TROUGH AXIS REMAINS DISPLACED WEST OF
THE COASTAL CAROLINAS. WHILE DRIER AND COOLER AIR IS ANTICIPATED
TUE/WED...WITH TEMPS RUNNING SEVERAL DEGREES BELOW NORMAL...LOCALLY
WE WILL NOT BE AS COOL AS OUR NEIGHBORS WELL WEST. LOWER POP IS
EXPECTED THROUGH MID-WEEK...BUT INCREASING E/NE FLOW MAY ALLOW FOR
RESIDUAL RAIN CHANCES TO PERSIST ALONG THE COAST THROUGH THE END OF
THE PERIOD.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 18Z...POSSIBLE MVFR/IFR IN ANY HEAVY DOWNPOURS THIS AFTERNOON
AND EVENING AS CHANCES FOR SHRA/TSRA INCREASING THROUGHOUT THE
DAY...ALONG WITH PATCHY FOG POSSIBLE BEFORE DAYBREAK ON FRIDAY.
OTHERWISE EXPECT VFR.
VFR PREVAILS THIS AFTERNOON WITH WEST-SOUTHWEST WINDS AOB 15 KTS AND
GUSTS ALREADY NEAR 20 KTS ALONG THE COAST. A CU FIELD HAS BEGUN TO
DEVELOP NICELY AS SEEN FROM LATEST SATELLITE IMAGERY AHEAD OF AN
APPROACHING COLD FRONT...AND EXPECT CLOUD COVER TO BE SCT/BKN
THROUGHOUT THE REST OF THE DAY AS CHANCES FOR SHRA/TSRA INCREASES.
THOUGH THUNDERSTORMS WILL TAPER OFF THIS EVENING...ANTICIPATE
SHOWERS TO PERSIST INTO THE EARLY OVERNIGHT HOURS. BRIEF PERIODS OF
MVFR/IFR ARE POSSIBLE IN ANY SHRA/TSRA ESPECIALLY WITH HEAVIER
DOWNPOURS AND LOWER CIGS. LATE OVERNIGHT INTO THE EARLY MORNING
HOURS...MVFR/IFR IS POSSIBLE DUE TO PATCHY FOG...ESPECIALLY INLAND.
INTO THE MORNING HOURS...LIGHT WINDS AND CONDITIONS WILL IMPROVE TO
VFR WITH A CHANCE OF SHRA/TSRA AGAIN ON FRIDAY.
EXTENDED OUTLOOK...SHOWERS/TSTMS/TEMPO MVFR POSSIBLE THROUGH
FRIDAY...AS WELL AS SUNDAY AND MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM THURSDAY...THE SEABREEZE CIRCULATION IS DEVELOPING...
AND WHEN ADDED TO THE BACKGROUND SOUTHWEST WIND WE ARE SEEING
WIDESPREAD GUSTS IN THE 16-19 KNOT RANGE BEING REPORTED. WIND SPEEDS
SHOULD ONLY INCREASE A BIT FURTHER LATER THIS AFTERNOON...BUT SEAS
NOW WILL HAVE TO PLAY "CATCH UP" TO ADJUST TO THESE HIGHER WIND
SPEEDS. LOOK FOR SEAS IN OPEN WATERS TO BUILD TO A SOLID 4 FEET IF
NOT 5 FEET AWAY FROM SHORE. PREVIOUS DISCUSSION FROM 1015 AM
FOLLOWS...
WEST-SOUTHWEST WINDS ARE ALREADY GUSTING TO 20 KNOTS AT THE OCEAN
CREST PIER ON OAK ISLAND...WITH 12-15 KNOTS PREVAILING ELSEWHERE. NO
SIGNIFICANT CHANGES ARE NEEDED TO THE PREVIOUS FORECAST...EXCEPT FOR
LOWERING SEA HEIGHTS BY ABOUT 1 FOOT INITIALLY BASED ON AVAILABLE
BUOY DATA. PREVIOUS DISCUSSION FROM 600 AM FOLLOWS...
A TIGHTER PRESSURE GRADIENT WILL BE REALIZED TODAY INTO THIS EVENING
AS A RATHER IMPRESSIVE TROUGH FOR THIS TIME OF YEAR APPROACHES.
SOUTHWEST SUSTAINED WIND SPEEDS ARE EXPECTED TO REACH 20 KT WITH
GUSTS TO 25 KT. SEAS TODAY ARE EXPECTED TO REACH UP TO 4 TO 5
FT...WITH SOME 6 FT SEAS POSSIBLE ACROSS THE OUTERMOST WATERS LATE
DAY AND THIS EVE. AT THIS TIME...WILL ISSUE A SMALL CRAFT SHOULD
EXERCISE CAUTION HEADLINE. THE FRONTAL ZONE SHOULD BE NEARING THE
WATERS LATE TONIGHT AND EXPECT THE WIND DIRECTION OVERNIGHT WILL
VEER TO A MORE WESTERLY DIRECTION WITH WIND SPEEDS DECREASING TO 10
TO 15 KT.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...WESTERLY WINDS WILL BEGIN THE PERIOD AS A
COLD FRONT WAVERS JUST OFF THE COAST. THIS FRONT WILL LIFT SLOWLY
BACK TO THE NORTH DURING FRIDAY...WITH WINDS REMAINING
LIGHT...AROUND 10 KTS...BUT BACKING TO THE SW THROUGH SUNDAY
MORNING. THEREAFTER...WINDS WILL INCREASE THROUGH SATURDAY AS THE
PRESSURE GRADIENT TIGHTENS ABOUT AROUND HIGH PRESSURE RIDGING BACK
TOWARDS THE COAST...WITH SPEEDS RISING FROM THE SW TO AROUND 15 KTS.
SEAS WILL BE 3-4 FT EARLY FRIDAY...AND RISE AGAIN TO 3-4 FT LATE
SATURDAY. IN BETWEEN 1-3 FT SEAS WILL BE COMMON THANKS TO THE
EXTENDED PERIOD OF LIGHTER WINDS.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 300 AM THURSDAY...HIGH PRESSURE OFFSHORE RIDGING TOWARDS THE
COAST...AND A STRONG COLD FRONT SLOWLY APPROACHING FROM THE
NW...WILL PINCH THE GRADIENT SUNDAY AND MONDAY. THIS DRIVES SW WINDS
UP TO 20 KTS OR MORE BOTH DAYS...AND PUSHES WIND-DRIVEN SEAS UP TO
4-6 FT. AN SCA MAY BE NEEDED FOR AN EXTENDED PORTION OF THIS PERIOD
AHEAD OF THE COLD FRONT WHICH IS PROGGED TO CROSS THE WATERS BY
TUESDAY MORNING.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RJD/TRA
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1024 AM EDT THU JUL 24 2014
.SYNOPSIS...
HEAT INDEX VALUES SHOULD TOP 100 DEGREES THIS AFTERNOON. A COLD
FRONT WILL APPROACH FROM THE NORTHWEST TODAY...BRINGING AN
INCREASING RISK FOR STRONG THUNDERSTORMS LATE THIS AFTERNOON INTO
TONIGHT. THIS FRONT WILL STALL ACROSS THE AREA FRIDAY BEFORE
DISSIPATING ON SATURDAY. HIGH PRESSURE WILL BRING HOT AND HUMID
CONDITIONS SUNDAY AND MONDAY. A STRONG COLD FRONT WILL CROSS THE
AREA EARLY TUESDAY...BRINGING COOLER AND DRIER CONDITIONS FOR THE
MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM THURSDAY...CLEAR SKIES OVER THE AREA THIS MORNING
SHOULD TURN PARTLY CLOUDY OVER THE NEXT FEW HOURS. TEMPERATURES ARE
SOARING QUICKLY WITH MID TO UPPER 80S ALREADY OBSERVED. THE LATEST
FEW HRRR RUNS PLUS THE 00Z NSSL WRF ARE SHOWING A LATER CONVECTIVE
INITIATION TIME THAN OUR PREVIOUS FORECAST INDICATED...SO I HAVE
SHIFTED THE WINDOW OF HIGHEST FORECAST POPS INTO THE 4 PM TO 10 PM
RANGE. THIS ALSO IS WHEN WE COME UNDER THE BEST INFLUENCE OF THE
RIGHT-ENTRANCE REGION OF A HEALTHY 300 MB JET EXTENDING FROM THE
MID-ATLANTIC INTO THE CANADIAN MARITIMES. NO OTHER SIGNIFICANT
CHANGES ARE NEEDED...AND FORECAST TEMPERATURES/DEWPOINTS STILL
SUPPORT HEAT INDICES IN THE 100-104 RANGE THIS AFTERNOON. PREVIOUS
DISCUSSION FROM 600 AM FOLLOWS...
A QUICK MOVING MID-LEVEL SHORTWAVE MOVED ACROSS THE UPSTATE OF SOUTH
CAROLINA DURING THE LATE NIGHT AND WAS CURRENTLY MOVING NE ACROSS
CENTRAL NORTH CAROLINA. A FEW SHOWERS AND THUNDERSTORMS DEVELOPED IN
RESPONSE TO THIS ADDED LIFT AND ARE EXPECTED TO PASS BY TO OUR NORTH
THROUGH 9 AM. A WEAKER SECONDARY IMPULSE WAS MOVING NE ACROSS THE
EASTERN CAROLINAS...BUT CONVECTION HAS NOT DEVELOPED IN RESPONSE TO
THIS FEATURE.
A COLD FRONT WILL DROP INTO THE LEE SIDE TROUGH POSITION TODAY
AND THE FRONT WILL THEN SLIDE ACROSS THE FORECAST AREA TONIGHT...
LIKELY LYING ACROSS SOUTHERN AND EASTERN PORTIONS OF THE FORECAST
AREA AT DAYBREAK FRI. THE UPPER TROUGH WILL STILL BE UPSTREAM FRI
MORNING.
THE ATMOSPHERE WILL BE WARM AND MOIST THROUGH A DEEP LAYER WITH
PRECIPITABLE WATER VALUES INCREASING THROUGH THE AFTERNOON/EVE...
IN EXCESS OF 2 INCHES...AND ALONG THE COAST...ABOVE 2.25 INCHES.
TEMPERATURES ARE EXPECTED TO REACH THE LOWER TO MID 90S TODAY. THIS
WILL BRING MIXED LAYER CAPE VALUES IN THE NEIGHBORHOOD OF 2000-2500
J/KG. MID LEVEL LAPSE RATES AND SHEAR VALUES ARE UNIMPRESSIVE...BUT
MID-LEVEL WINDS WILL BE ON THE ORDER OF 40 KT. THE BIGGEST RISK WITH
THUNDERSTORMS TODAY AND TONIGHT WILL BE FREQUENT LIGHTNING AND HEAVY
RAIN...ALTHOUGH STORM MOTIONS ARE MUCH HIGHER THAN EARLIER IN THE
WEEK WHICH SHOULD LIMIT THE EXCESSIVE RAINFALL THREAT. HOWEVER...THE
DEEPEST CONVECTION WILL BE CAPABLE OF STRONG WIND GUSTS AND AN
ISOLATED WET MICROBURST WITH DAMAGING WINDS CAN NOT BE RULED OUT.
THUNDERSTORMS MAY DEVELOP ALONG THE COAST AS A RATHER SHARP
SEABREEZE BOUNDARY DEVELOPS LATER THIS MORNING/MIDDAY. ELSEWHERE...
AFTERNOON THUNDERSTORMS WILL POP AS THE CONVECTIVE TEMPS ARE
EXCEEDED. THE CONVECTION SHOULD TEND TO BECOME MORE ORGANIZED MID
AND LATE AFTERNOON AS IT MOVES TOWARD THE COAST. WE EXPECT
CONVECTION TO LAST WELL INTO THE NIGHT IF NOT THROUGH THE NIGHT AS A
MODEST SHORTWAVE ALOFT INTERACTS WITH THE SURFACE FRONT.
HEAT INDEX VALUES LATE MORNING AND THIS AFTERNOON WILL REACH 100
DEGREES IN MOST AREAS AND AS HIGH AS 104 DEGREES. OF COURSE...ONCE A
STRONG THUNDERSTORM MOVES OVERHEAD...THE HEAT WILL GET KNOCKED
DOWN...BUT NOT THE HUMIDITY.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...COLD FRONT STALLED ACROSS THE AREA WILL
CONTINUE SHOWER AND THUNDERSTORM CHANCES ON FRIDAY...BUT AT THE SAME
TIME DRIER AIR WILL BEGIN TO ADVECT IN FROM THE WEST...DRYING OUT
THE MID AND UPR PORTIONS OF THE COLUMN. STILL...WITH THE FRONT IN
PLACE...TEMPS RISING TO AROUND 90...AND DEWPOINTS IN THE LOW
70S...THERE WILL BE PLENTY OF FUEL AROUND FOR CONVECTION BEFORE THE
DRIER AIR WORKS INTO THE CWA. THUS WILL CARRY CHC POP
FRIDAY...HIGHEST ACROSS THE EASTERN PORTIONS OF THE CWA. THE DIURNAL
TREND FOR CONVECTION MAY BE A BIT ATYPICAL AS THE DRY AIR INTRUDES
OVERHEAD...AND THE HIGHEST COVERAGE OF CONVECTION MAY BE LATE
MORNING/EARLY AFTN BEFORE TAPERING OFF INTO THE EVE. THIS FRONT WILL
WASH OUT FRIDAY NIGHT LEAVING MOSTLY CLEAR SKY CONDITIONS...BUT AS
LIGHT SW FLOW RE-DEVELOPS...MINS WILL FALL ONLY INTO THE MID 70S AT
THE COAST...AND TO AROUND 70 INLAND.
ANY AIRMASS CHANGE ASSOCIATED WITH THE PRIOR FRONT QUICKLY ERODES
SATURDAY...LEAVING A HOT DAY ACROSS THE CWA. FORTUNATELY...THE
COLUMN WILL BE DRIER...AND THUS HUMIDITY VALUES WILL BE MUCH
LOWER...KEEPING APPARENT TEMPS TO BELOW 100 EVEN AS HIGHS CLIMB TO
AROUND 90 AT THE COAST...MID 90S WELL INLAND. WILL CONTINUE WITH THE
INHERITED SCHC POP ON SATURDAY SIMPLY DUE TO THE HEAT...BUT ONLY
ISOLATED STORMS ARE POSSIBLE AS PWATS DROP TO LESS THAN 1.5 INCHES.
INCREASING SW RETURN FLOW SATURDAY NIGHT WILL PREVENT SIGNIFICANT
COOLING...AND THUS LOWS SAT NIGHT WILL BE WELL ABOVE NORMAL...UPR
70S AT THE BEACHES TO LOW 70S ONLY WELL INLAND.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...A HOT START TO THE PERIOD...BUT IT WILL BE
SHORT LIVED AS...ONCE AGAIN...AN ANOMALOUSLY STRONG UPPER TROUGH
DIVES ACROSS THE EASTERN CONUS.
SUNDAY LOOKS TO BE THE HOTTEST DAY OF THE PERIOD AS SUBTLE MID-LEVEL
RIDGING AND STRONG SW RETURN FLOW AROUND A RIDGE OF HIGH PRESSURE
PUSH TEMPS INTO THE MID AND MAYBE UPR 90S...AND WE MAY EXPERIENCE
OUR FIRST HEAT ADVISORY OF 2014 (HEAT INDEX OF 105 OR GREATER).
ALTHOUGH HUMIDITY WILL INCREASE ON SUNDAY AS WELL...CONVECTIVE
COVERAGE MAY BE QUITE LIMITED DUE TO SOME MID-LEVEL DRY AIR
PERSISTING...AND A LID WITHIN A LOW-LEVEL THERMAL RIDGE. MONDAY WILL
BE SIMILAR...ALTHOUGH A DEGREE OR 2 COOLER AS CLOUD COVER INCREASES
AND MID-LEVEL HEIGHTS DECREASE AHEAD OF AN ADVANCING COLD FRONT.
INCREASING POP IS WARRANTED MONDAY AS WELL...WITH THE BEST CHANCE
OCCURRING MONDAY NIGHT AS THE COLD FRONT MOVES INTO THE AREA. LOWS
BOTH NIGHTS WILL BE ABOVE NORMAL IN MID AND UPR 70S.
BIG AIR MASS CHANGE OCCURS THEREAFTER AS -3 SD TROUGH DROPS INTO
THE MIDWEST...DRIVING A STRONG COLD FRONT INTO THE CWA AND OFFSHORE
DURING TUESDAY. THIS TROUGH WILL PRODUCE LOWERED HEIGHTS ALL THE WAY
INTO THE GULF OF MEXICO THROUGH THE MIDDLE OF NEXT WEEK...BUT
FORTUNATELY FOR THE AREA THE TROUGH AXIS REMAINS DISPLACED WEST OF
THE COASTAL CAROLINAS. WHILE DRIER AND COOLER AIR IS ANTICIPATED
TUE/WED...WITH TEMPS RUNNING SEVERAL DEGREES BELOW NORMAL...LOCALLY
WE WILL NOT BE AS COOL AS OUR NEIGHBORS WELL WEST. LOWER POP IS
EXPECTED THROUGH MID-WEEK...BUT INCREASING E/NE FLOW MAY ALLOW FOR
RESIDUAL RAIN CHANCES TO PERSIST ALONG THE COAST THROUGH THE END OF
THE PERIOD.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 12Z...POSSIBLE MVFR/IFR IN ANY HEAVY DOWNPOURS THIS AFTERNOON
AND EVENING AS CHANCES FOR SHRA/TSRA INCREASING THROUGHOUT THE
DAY...ALONG WITH PATCHY FOG POSSIBLE BEFORE DAYBREAK ON FRIDAY.
OTHERWISE EXPECT VFR.
WITH SOUTHWEST WINDS AOB 10 KTS...VFR PREVAILS THIS MORNING ACROSS
THE AREA...WITH THE EXCEPTION OF KLBT WHICH IS EXPERIENCING IFR DUE
TO LOW CIGS. WOULD NOT ENTIRELY RULE OUT A VERY BRIEF PERIOD OF IFR
AT KFLO AS WELL IN THE NEXT HOUR OR TWO AS LOW CIGS MOVE ABOUT THE
INLAND AREAS AS SEEN FROM LATEST 11.9-3.9 SATELLITE IMAGERY.
AFTER 14Z...EXPECT ALL SITES TO BE VFR WITH SOUTHWEST WINDS AOB 12
KTS AHEAD OF AN APPROACHING COLD FRONT AND GUSTS INCREASING TO
AROUND 20 KTS BEGINNING OVER THE NEXT FEW HOURS. CHANCES WILL
INCREASE FOR SHOWERS AND THUNDERSTORMS THROUGHOUT THE DAY WITH THE
COLD FRONT...AND THOUGH THUNDERSTORMS WILL TAPER OFF THIS
EVENING...ANTICIPATE SHOWERS TO PERSIST INTO THE EARLY OVERNIGHT
HOURS. BRIEF PERIODS OF MVFR/IFR ARE POSSIBLE IN ANY SHRA/TSRA
ESPECIALLY WITH HEAVIER DOWNPOURS AND LOWER CIGS. LATE OVERNIGHT
INTO THE EARLY MORNING HOURS...MVFR IS POSSIBLE DUE TO PATCHY FOG.
EXTENDED OUTLOOK...SHOWERS/TSTMS/TEMPO MVFR POSSIBLE THROUGH
FRIDAY...AS WELL AS SUNDAY AND MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM THURSDAY...WEST-SOUTHWEST WINDS ARE ALREADY GUSTING TO
20 KNOTS AT THE OCEAN CREST PIER ON OAK ISLAND...WITH 12-15 KNOTS
PREVAILING ELSEWHERE. NO SIGNIFICANT CHANGES ARE NEEDED TO THE
PREVIOUS FORECAST...EXCEPT FOR LOWERING SEA HEIGHTS BY ABOUT 1 FOOT
INITIALLY BASED ON AVAILABLE BUOY DATA. PREVIOUS DISCUSSION FROM 600
AM FOLLOWS...
A TIGHTER PRESSURE GRADIENT WILL BE REALIZED TODAY INTO THIS EVENING
AS A RATHER IMPRESSIVE TROUGH FOR THIS TIME OF YEAR APPROACHES.
SOUTHWEST SUSTAINED WIND SPEEDS ARE EXPECTED TO REACH 20 KT WITH
GUSTS TO 25 KT. SEAS TODAY ARE EXPECTED TO REACH UP TO 4 TO 5
FT...WITH SOME 6 FT SEAS POSSIBLE ACROSS THE OUTERMOST WATERS LATE
DAY AND THIS EVE. AT THIS TIME...WILL ISSUE A SMALL CRAFT SHOULD
EXERCISE CAUTION HEADLINE. THE FRONTAL ZONE SHOULD BE NEARING THE
WATERS LATE TONIGHT AND EXPECT THE WIND DIRECTION OVERNIGHT WILL
VEER TO A MORE WESTERLY DIRECTION WITH WIND SPEEDS DECREASING TO 10
TO 15 KT.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...WESTERLY WINDS WILL BEGIN THE PERIOD AS A
COLD FRONT WAVERS JUST OFF THE COAST. THIS FRONT WILL LIFT SLOWLY
BACK TO THE NORTH DURING FRIDAY...WITH WINDS REMAINING
LIGHT...AROUND 10 KTS...BUT BACKING TO THE SW THROUGH SUNDAY
MORNING. THEREAFTER...WINDS WILL INCREASE THROUGH SATURDAY AS THE
PRESSURE GRADIENT TIGHTENS ABOUT AROUND HIGH PRESSURE RIDGING BACK
TOWARDS THE COAST...WITH SPEEDS RISING FROM THE SW TO AROUND 15 KTS.
SEAS WILL BE 3-4 FT EARLY FRIDAY...AND RISE AGAIN TO 3-4 FT LATE
SATURDAY. IN BETWEEN 1-3 FT SEAS WILL BE COMMON THANKS TO THE
EXTENDED PERIOD OF LIGHTER WINDS.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 300 AM THURSDAY...HIGH PRESSURE OFFSHORE RIDGING TOWARDS THE
COAST...AND A STRONG COLD FRONT SLOWLY APPROACHING FROM THE
NW...WILL PINCH THE GRADIENT SUNDAY AND MONDAY. THIS DRIVES SW WINDS
UP TO 20 KTS OR MORE BOTH DAYS...AND PUSHES WIND-DRIVEN SEAS UP TO
4-6 FT. AN SCA MAY BE NEEDED FOR AN EXTENDED PORTION OF THIS PERIOD
AHEAD OF THE COLD FRONT WHICH IS PROGGED TO CROSS THE WATERS BY
TUESDAY MORNING.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RJD/TRA
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
630 AM EDT THU JUL 24 2014
.SYNOPSIS...A COLD FRONT WILL PUSH SOUTHEASTWARD THROUGH THE REGION
LATE TODAY THROUGH TONIGHT. THIS FRONT WILL STALL OUT NEAR THE SOUTH
CAROLINA BORDER ON FRIDAY... AS WEAK HIGH PRESSURE BUILDS IN FROM
THE NORTH. THIS FRONT WILL THEN WEAKEN AND HEAD BACK NORTH OF THE
AREA OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 320 AM THURSDAY...
IT`S LOOKING LIKE THE BROAD BROKEN BAND OF PREFRONTAL SHOWERS AND
STORMS WILL MOVE INTO AND THROUGH THE CWA FAIRLY EARLY TODAY...
DURING THE MORNING THROUGH MID AFTERNOON... WHICH COULD CUT DOWN ON
OUR SEVERE THREAT OVER ALL BUT THE SE AND EXTREME ERN CWA. THE
LATEST SURFACE MAP SHOWS THE INCOMING SURFACE FRONT STRETCHING
ACROSS THE OH VALLEY... WITH A PREFRONTAL TROUGH EXTENDING THROUGH
CENTRAL VA AND THE NC FOOTHILLS. WE`RE ALREADY STARTING TO SEE A FEW
SHOWERS FORMING ESE OF THIS CONVECTION OVER THE EAST SLOPES... AND
THE HRRR SHOWS THIS MORE EASTERLY ACTIVITY EXPANDING AND BECOMING
THE DOMINANT PREFRONTAL CONVECTION THIS MORNING AS IT HEADS INTO THE
TRIAD REGION... EVENTUALLY SHIFTING EAST THROUGH THE PIEDMONT
THROUGH THE NOON HOUR. THE LARGER SCALE MODELS SUGGEST THIS AS
WELL... DEPICTING PRETTY GOOD COVERAGE OF PRECIP OVER NEARLY THE
ENTIRE CWA BY 18Z. GIVEN THIS TREND IN BOTH RADAR IMAGERY AND MODEL
OUTPUT... WILL FOLLOW THIS PATH AND BRING IN HIGH CHANCE TO LIKELY
POPS EARLIER THIS MORNING OVER THE WRN/NRN CWA... HIGHEST ACROSS THE
NRN HALF OF THE FORECAST AREA FROM LATE MORNING INTO EARLY
AFTERNOON. THE FOCUS OF THE GREATEST CONVECTION COVERAGE SHOULD THEN
SHIFT TO THE COASTAL PLAIN AND SANDHILLS FROM MID AFTERNOON TO EARLY
EVENING AS THE PREFRONTAL TROUGH PUSHES SOUTHEASTWARD THROUGH THE
CWA. BUT ADDITIONAL SCATTERED SHOWERS/STORMS ARE EXPECTED JUST AHEAD
OF AND WITH THE COLD FRONT ITSELF... WHICH IS EXPECTED TO REACH THE
SPINE OF THE APPALACHIANS BY 00Z THIS EVENING... PROPELLED BY
RELATIVELY COOL HIGH PRESSURE CENTERED NEAR CHICAGO. THE SOUTHEAST
MOVEMENT OF THIS FRONT IS APT TO BE SLOWED BY THREE FACTORS: THE
EXTRA EFFORT IT WILL TAKE THE DENSER HIGH PRESSURE AREA TO GET OVER
THE MOUNTAINS... A STEERING FLOW THAT WILL BE NEARLY PARALLEL TO THE
SURFACE FRONT... AND EXPECTATIONS OF SURFACE LOW PRESSURE
ENHANCEMENT OVER THE SOUTHERN FOOTHILLS TONIGHT. GIVEN THE POTENTIAL
FOR A DELAY IN THE ARRIVAL OF THE DRIER AND MORE STABLE COLUMN FROM
NW TO SE UNTIL THE OVERNIGHT HOURS... WILL HOLD CHANCE POPS THROUGH
THE MID-LATE EVENING AREAWIDE BEFORE TRENDING THEM DOWN AND OUT NW
TO SE LATE TONIGHT.
REGARDING THE RISK OF STRONG/SEVERE STORMS... AS NOTED ABOVE... THIS
RISK LOOK GREATLY LIMITED ACROSS THE NRN AND FAR WRN CWA DUE TO
CLOUD COVER AND EARLY PRECIP ARRIVAL. CHANCES ARE BETTER IN THE
SOUTHEAST AND EXTREME EAST... WHERE THE NAM DEPICTS MLCAPE NEAR 1500
J/KG LATE MORNING INTO EARLY AFTERNOON. WE`VE GOT IMPROVED DEEP
LAYER SHEAR TO 25-35 KTS AS WELL. BUT THE ENTIRE TIMING OF THIS
SYSTEM (WELL BEFORE MAX HEATING) AND EARLY CLOUD COVER SHOULD KEEP
INSTABILITY DOWN. BUT THE NRN/WRN CWA IS NOT OUT OF THE WOODS AS WE
MAY ACTUALLY HAVE A BIT MORE CONCERN LATE THIS AFTERNOON THROUGH
EARLY EVENING AHEAD OF THE FRONT... IF WE CAN GET PARTIAL CLEARING
BEHIND THIS MORNING ACTIVITY. THE GFS SHOWS INITIALLY SMALL MUCAPE
IN THE MORNING IN THE NW CWA REBOUNDING ABOVE 1000 J/KG LATE
TODAY... NOT A HUGE NUMBER OF COURSE BUT ENOUGH TO RETAIN AT LEAST
SOME CONCERN FOR A STRONG WIND-PRODUCING STORM OR TWO AREAWIDE.
WHILE CELL MOTIONS ARE EXPECTED TO BE GREATER THAN IN PREVIOUS
DAYS... WE MAY SEE TRAINING CELLS REPEATEDLY OVER THE SAME AREA...
AND A RISK OF LOCALLY HIGH RAIN TOTALS WILL PERSIST.
TEMPS SHOULD INITIALLY BE HELD DOWN BY CLOUDS AND PATCHY PRECIP THIS
MORNING... BUT ANY THIN SPOTS IN THE CLOUDS BETWEEN THIS PREFRONTAL
CONVECTION AND SHOWERS/STORMS IMMEDIATELY AHEAD OF THE FRONT WILL
PUSH TEMPS UP QUICKLY. SO STILL EXPECT HIGHS FROM 86 TO 92. LOWS
TONIGHT 66-72... STILL MUGGY ACROSS THE SE. -GIH
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 320 AM THURSDAY...
FOR FRI/FRI NIGHT: LITTLE CHANGED NEEDED TO EXISTING FORECAST. STILL
EXPECT THE FRONT TO HANG UP ACROSS THE SE CWA AND ALONG THE
CENTRAL/WRN NC/SC BORDER... AS THE 850 MB TROUGH HOLDS TO ITS NW
ACROSS FAR NRN NC. THIS WILL KEEP ENOUGH LOW LEVEL MOISTURE WHICH...
IN CONJUNCTION WITH LINGERING PW VALUES NEAR 1 INCH... NECESSITATES
A MENTION OF ISOLATED TO SCATTERED SHOWERS AND STORMS OVER THE FAR
SE CWA... FOCUSED ON THE TYPICAL AFTERNOON THROUGH EARLY EVENING
TIME FRAME. MUCH LOWER PW OVER THE REMAINDER OF THE CWA AND MODEST
RISE IN HEIGHTS AS THE MID LEVEL TROUGH WEAKENS AND STARTS TO PULL
AWAY WILL LEAD TO MAINLY DRY WEATHER ELSEWHERE... ALTHOUGH ONE LAST
SHOT OF DPVA THROUGH THE EXITING TROUGH BASE WILL DELAY THE MOST
SUBSTANTIAL NW-TO-SE CLEARING UNTIL LATE IN THE DAY. HIGHS 85-90...
WITH THICKNESSES SLIPPING TO 10-15 M BELOW NORMAL. LOWS 65-71. -GIH
SAT AND SAT NIGHT: THE REMNANT FRONT FROM EARLY IN THE PERIOD WILL
BECOME INCREASINGLY DIFFUSE AS IT RETREATS NORTH ACROSS THE MIDDLE
ATLANTIC STATES ON SAT...WITH A PRIMARY IMPACT FOR CENTRAL NC BEING
THE DEVELOPMENT OF A WARMING SOUTHERLY FLOW - HIGH TEMPERATURES
GENERALLY BETWEEN 89 AND 93 DEGREES. ALOFT...MODEL GUIDANCE IS IN
GOOD AGREEMENT REGARDING THE PROGRESSION OF A MID LEVEL TROUGH FROM
THE APPALACHIAN SPINE SAT MORNING TO THE COAST BY EVENING...BUT
ASSOCIATED FORECAST VERTICAL MOTION WITH THIS FEATURE IS WEAK...AND
NAM FORECAST BUFR SOUNDINGS ARE AN UNSTABLE AND UNCAPPED OUTLIER
RELATIVE TO THE GFS AND SREF ENSEMBLE MEAN. THE NAM QPF MAXIMUM FROM
SE VA THROUGH CENTRAL NC IS ALSO AN OUTLIER RELATIVE TO OTHER
GUIDANCE...WHICH OTHERWISE CONFINES ANY SHOWERS/STORMS TO THE SEA
BREEZE. WILL CONSEQUENTLY MAINTAIN JUST A SLIGHT CHANCE POP OVER THE
SOUTHERN AND CENTRAL COASTAL PLAIN...WHERE WEAK LIFT AHEAD OF THE
AFOREMENTIONED TROUGH ALOFT WILL BE DIURNALLY MAXIMIZED AND
COINCIDENT WITH LOW LEVEL FORCING INVOF THE SEA-BREEZE/SUBSEQUENT
OUTFLOW DURING THE MID-LATE AFTERNOON.
SHORTWAVE RIDGING WILL BRIEFLY FOLLOW FOR SAT NIGHT...WITH DRY
CONDITIONS AND LOWS MAINLY IN THE LOWER 70S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 335 AM THURSDAY...
THE MEDIUM RANGE WILL BE CHARACTERIZED BY THE DEVELOPMENT OF ANOTHER
UNSEASONABLY HIGH AMPLITUDE TROUGH ALOFT FROM SOUTHEASTERN CANADA
INTO THE EASTERN US...WITH AN ASSOCIATED NEGATIVE HEIGHT OF NEARLY 3
STANDARD DEVIATIONS BELOW AVERAGE FROM THE LOWER GREAT LAKES/OHIO
VALLEY TO THE CENTRAL APPALACHIANS. PRECIPITATION CHANCES DURING THE
PERIOD WILL BE HIGHEST SUN NIGHT-MON...AS THE TROUGH AMPLIFIES
SOUTHEASTWARD AND SPREADS THE ASSOCIATED MID LEVEL HEIGHT FALLS AND
UNDERLYING LO LEVEL FRONTAL ZONE ACROSS NC.
IN FACT...THE DAY SUNDAY SHOULD BE MAINLY DRY...AND HOT AS THE MID
LEVEL RIDGE OVER THE DESERT SW AND PLAINS BUILDS BRIEFLY EAST IN
ADVANCE OF THE AMPLIFYING TROUGH ALOFT. H85 TEMPERATURES ARE
FORECAST TO SURGE...ALBEIT BRIEFLY...INTO THE 22-24 DEGREE RANGE
OVER THE CAROLINAS...SUPPORTIVE OF HIGH TEMPERATURES SOLIDLY IN THE
MIDDLE 90S. UPSTREAM PRE-FRONTAL CONVECTION AND ASSOCIATED OUTFLOW
WILL THEN LIKELY DRIFT...IN A GRADUALLY WEAKENING STATE OWING TO
NOCTURNAL COOLING...INTO THE NORTHERN AND WESTERN PIEDMONT DURING
THE EVENING AND EARLY NIGHTTIME HOURS.
THE PATTERN ON THE SYNOPTIC SCALE...CHARACTERIZED BY THE APPROACHING
STRONG TROUGH AND DOWNSTREAM JET ENTRANCE DIVERGENCE ALOFT...AND LOW
LEVEL FRONTAL FORCING...FAVORS CONSIDERABLE THUNDERSTORM COVERAGE
MON...INCLUDING SOME SEVERE OWING TO UNSEASONABLY STRONG MID LEVEL
FLOW ON THE ORDER OF 40-50 KTS. HOWEVER...PREDICTABILITY ASSOCIATED
WITH MESOSCALE INFLUENCES (IE. OUTFLOW AND CLOUD COVER) FROM EARLIER
CONVECTION SUN NIGHT COMPLICATE THE FORECAST SO PROBABILITY OF
PRECIPITATION WILL BE KEPT IN THE HIGH CHANCE RANGE FOR NOW...WITH
THE EXPECTATION THAT THESE PROBABILITIES WILL BE INCREASED OVER AT
LEAST A PORTION OF THE FORECAST AREA (LIKELY THE SOUTHEAST HALF).
THE MIDDLE OF THE WEEK SHOULD BE DRY...AND COOLER...AS POST-FRONTAL
HIGH PRESSURE BUILDS INTO THE CENTRAL APPALACHIANS...AND
PRECIPITABLE WATER VALUES FALL BELOW AN INCH OVER CENTRAL NC. HIGHS
AND LOWS ONLY IN THE LOWER TO MIDDLE 80S AND LOWER TO MIDDLE
60S...RESPECTIVELY...TUE-WED.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 630 AM THURSDAY...
VFR CONDITIONS ARE LIKELY TO DOMINATE TODAY AT ALL TAF SITES...
ALTHOUGH SCATTERED CLOUDS BASED AT 600-900 FT WILL PASS OVER OR NEAR
RDU/RWI/FAY THROUGH 14Z. CURRENTLY THE VAST MAJORITY OF CLOUD COVER
OVER CENTRAL NC IS LIMITED TO HIGH CLOUDS BASED ABOVE 10 000 FT
AGL... AND WHILE CIGS WILL BE DROPPING AHEAD OF THE COLD FRONT
APPROACHING FROM THE NW... THEY SHOULD STAY VFR. THE EXCEPTION WILL
BE IN/NEAR SCATTERED TO NUMEROUS SHOWERS AND STORMS THAT ARE
OCCURRING NEAR INT/GSO... WHERE CIGS/VSBYS MAY DROP TO MVFR... ALONG
WITH ENHANCED WIND GUSTS. THESE SHOWERS/STORMS ARE THEN EXPECTED TO
AFFECT RDU AND RWI STARTING AROUND 13Z OR 14Z... AND FAY STARTING AT
17Z OR 18Z. ADDITIONAL SCATTERED STORMS ARE POSSIBLE MAINLY AT
INT/GSO/RDU DURING THE MID-LATE AFTERNOON... BUT UNCERTAINTIES
REGARDING COVERAGE AND TIMING PRECLUDE MENTIONING THESE IN THE TAFS
AT THIS TIME. TOUGH CALL ON WHEN THE STORM THREAT WILL EXIT TAF
SITES... BUT VFR CONDITIONS SHOULD RETURN SOON AFTER 22Z AT GSO...
00Z AT RDU/RWI... AND PROBABLY NOT UNTIL AFTER 04Z AT FAY. SURFACE
WINDS WILL REMAIN FAIRLY LIGHT LATE TONIGHT BUT SHIFT AROUND TO
MAINLY NNE AS THE FRONT PUSHES SOUTHEAST THROUGH NC. AS THESE
SURFACE WINDS SHIFT AROUND TO LIGHT FROM THE NE OR LIGHT/VRBL LATE
TONIGHT... A SHORT PERIOD OF IFR CIGS/VSBYS IS POSSIBLE AT ALL SITES
FROM 09Z-12Z.
LOOKING BEYOND 12Z FRI MORNING... THE FRONT WILL LIKELY SLOW DOWN
ENOUGH OVER SE NC TO KEEP A CHANCE OF SUB-VFR SHOWERS/STORMS AT FAY
THROUGH FRI AFTERNOON... BUT OTHERWISE VFR CONDITIONS ARE EXPECTED
FRI-SAT AS HIGH PRESSURE NOSES IN FROM THE NORTH. THIS FRONT WILL
SHIFT BACK NORTH AND DISSIPATE OVER THE WEEKEND WITH A SURFACE
TROUGH REFORMING OVER CENTRAL NC. AN UPPER LEVEL DISTURBANCE AND
ACCOMPANYING COLD FRONT WILL MOVE IN FROM THE NORTHWEST ON SUNDAY...
POTENTIALLY BRINGING ANOTHER ROUND OF SHOWERS/STORMS LATE SUNDAY
INTO MONDAY. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS..HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD/MWS
LONG TERM...MWS
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
338 AM EDT THU JUL 24 2014
.SYNOPSIS...A COLD FRONT WILL PUSH SOUTHEASTWARD THROUGH THE REGION
LATE TODAY THROUGH TONIGHT. THIS FRONT WILL STALL OUT NEAR THE SOUTH
CAROLINA BORDER ON FRIDAY... AS WEAK HIGH PRESSURE BUILDS IN FROM
THE NORTH. THIS FRONT WILL THEN WEAKEN AND HEAD BACK NORTH OF THE
AREA OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 320 AM THURSDAY...
IT`S LOOKING LIKE THE BROAD BROKEN BAND OF PREFRONTAL SHOWERS AND
STORMS WILL MOVE INTO AND THROUGH THE CWA FAIRLY EARLY TODAY...
DURING THE MORNING THROUGH MID AFTERNOON... WHICH WILL GREATLY CUT
DOWN ON OUR SEVERE THREAT OVER ALL BUT THE SE AND EXTREME ERN CWA.
THE LATEST SURFACE MAP SHOWS THE INCOMING SURFACE FRONT STRETCHING
ACROSS THE OH VALLEY... WITH A PREFRONTAL TROUGH EXTENDING THROUGH
CENTRAL VA AND THE NC FOOTHILLS. WE`RE ALREADY STARTING TO SEE A FEW
SHOWERS FORMING ESE OF THIS CONVECTION OVER THE EAST SLOPES... AND
THE HRRR SHOWS THIS MORE EASTERLY ACTIVITY EXPANDING AND BECOMING
THE DOMINANT PREFRONTAL CONVECTION THIS MORNING AS IT HEADS INTO THE
TRIAD REGION... EVENTUALLY SHIFTING EAST THROUGH THE PIEDMONT
THROUGH THE NOON HOUR. THE LARGER SCALE MODELS SUGGEST THIS AS
WELL... DEPICTING PRETTY GOOD COVERAGE OF PRECIP OVER NEARLY THE
ENTIRE CWA BY 18Z. GIVEN THIS TREND IN BOTH RADAR IMAGERY AND MODEL
OUTPUT... WILL FOLLOW THIS PATH AND BRING IN HIGH CHANCE TO LIKELY
POPS EARLIER THIS MORNING OVER THE WRN/NRN CWA... HIGHEST ACROSS THE
NRN HALF OF THE FORECAST AREA FROM LATE MORNING INTO EARLY
AFTERNOON. THE FOCUS OF THE GREATEST CONVECTION COVERAGE SHOULD THEN
SHIFT TO THE COASTAL PLAIN AND SANDHILLS FROM MID AFTERNOON TO EARLY
EVENING AS THE PREFRONTAL TROUGH PUSHES SOUTHEASTWARD THROUGH THE
CWA. BUT ADDITIONAL SCATTERED SHOWERS/STORMS ARE EXPECTED JUST AHEAD
OF AND WITH THE COLD FRONT ITSELF... WHICH IS EXPECTED TO REACH THE
SPINE OF THE APPALACHIANS BY 00Z THIS EVENING... PROPELLED BY
RELATIVELY COOL HIGH PRESSURE CENTERED NEAR CHICAGO. THE SOUTHEAST
MOVEMENT OF THIS FRONT IS APT TO BE SLOWED BY THREE FACTORS: THE
EXTRA EFFORT IT WILL TAKE THE DENSER HIGH PRESSURE AREA TO GET OVER
THE MOUNTAINS... A STEERING FLOW THAT WILL BE NEARLY PARALLEL TO THE
SURFACE FRONT... AND EXPECTATIONS OF SURFACE LOW PRESSURE
ENHANCEMENT OVER THE SOUTHERN FOOTHILLS TONIGHT. GIVEN THE POTENTIAL
FOR A DELAY IN THE ARRIVAL OF THE DRIER AND MORE STABLE COLUMN FROM
NW TO SE UNTIL THE OVERNIGHT HOURS... WILL HOLD CHANCE POPS THROUGH
THE MID-LATE EVENING AREAWIDE BEFORE TRENDING THEM DOWN AND OUT NW
TO SE LATE TONIGHT.
REGARDING THE RISK OF STRONG/SEVERE STORMS... AS NOTED ABOVE... THIS
RISK LOOK GREATLY LIMITED ACROSS THE NRN AND FAR WRN CWA DUE TO
CLOUD COVER AND EARLY PRECIP ARRIVAL. CHANCES ARE BETTER IN THE
SOUTHEAST AND EXTREME EAST... WHERE THE NAM DEPICTS MLCAPE NEAR 1500
J/KG LATE MORNING INTO EARLY AFTERNOON. WE`VE GOT IMPROVED DEEP
LAYER SHEAR TO 25-35 KTS AS WELL. BUT THE ENTIRE TIMING OF THIS
SYSTEM (WELL BEFORE MAX HEATING) AND EARLY CLOUD COVER SHOULD KEEP
INSTABILITY DOWN. BUT THE NRN/WRN CWA IS NOT OUT OF THE WOODS AS WE
MAY ACTUALLY HAVE A BIT MORE CONCERN LATE THIS AFTERNOON THROUGH
EARLY EVENING AHEAD OF THE FRONT... IF WE CAN GET PARTIAL CLEARING
BEHIND THIS MORNING ACTIVITY. THE GFS SHOWS INITIALLY SMALL MUCAPE
IN THE MORNING IN THE NW CWA REBOUNDING ABOVE 1000 J/KG LATE
TODAY... NOT A HUGE NUMBER OF COURSE BUT ENOUGH TO RETAIN AT LEAST
SOME CONCERN FOR A STRONG WIND-PRODUCING STORM OR TWO AREAWIDE.
WHILE CELL MOTIONS ARE EXPECTED TO BE GREATER THAN IN PREVIOUS
DAYS... WE MAY SEE TRAINING CELLS REPEATEDLY OVER THE SAME AREA...
AND A RISK OF LOCALLY HIGH RAIN TOTALS WILL PERSIST.
TEMPS SHOULD INITIALLY BE HELD DOWN BY CLOUDS AND PATCHY PRECIP THIS
MORNING... BUT ANY THIN SPOTS IN THE CLOUDS BETWEEN THIS PREFRONTAL
CONVECTION AND SHOWERS/STORMS IMMEDIATELY AHEAD OF THE FRONT WILL
PUSH TEMPS UP QUICKLY. SO STILL EXPECT HIGHS FROM 86 TO 92. LOWS
TONIGHT 66-72... STILL MUGGY ACROSS THE SE. -GIH
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 320 AM THURSDAY...
FOR FRI/FRI NIGHT: LITTLE CHANGED NEEDED TO EXISTING FORECAST. STILL
EXPECT THE FRONT TO HANG UP ACROSS THE SE CWA AND ALONG THE
CENTRAL/WRN NC/SC BORDER... AS THE 850 MB TROUGH HOLDS TO ITS NW
ACROSS FAR NRN NC. THIS WILL KEEP ENOUGH LOW LEVEL MOISTURE WHICH...
IN CONJUNCTION WITH LINGERING PW VALUES NEAR 1 INCH... NECESSITATES
A MENTION OF ISOLATED TO SCATTERED SHOWERS AND STORMS OVER THE FAR
SE CWA... FOCUSED ON THE TYPICAL AFTERNOON THROUGH EARLY EVENING
TIME FRAME. MUCH LOWER PW OVER THE REMAINDER OF THE CWA AND MODEST
RISE IN HEIGHTS AS THE MID LEVEL TROUGH WEAKENS AND STARTS TO PULL
AWAY WILL LEAD TO MAINLY DRY WEATHER ELSEWHERE... ALTHOUGH ONE LAST
SHOT OF DPVA THROUGH THE EXITING TROUGH BASE WILL DELAY THE MOST
SUBSTANTIAL NW-TO-SE CLEARING UNTIL LATE IN THE DAY. HIGHS 85-90...
WITH THICKNESSES SLIPPING TO 10-15 M BELOW NORMAL. LOWS 65-71. -GIH
SAT AND SAT NIGHT: THE REMNANT FRONT FROM EARLY IN THE PERIOD WILL
BECOME INCREASINGLY DIFFUSE AS IT RETREATS NORTH ACROSS THE MIDDLE
ATLANTIC STATES ON SAT...WITH A PRIMARY IMPACT FOR CENTRAL NC BEING
THE DEVELOPMENT OF A WARMING SOUTHERLY FLOW - HIGH TEMPERATURES
GENERALLY BETWEEN 89 AND 93 DEGREES. ALOFT...MODEL GUIDANCE IS IN
GOOD AGREEMENT REGARDING THE PROGRESSION OF A MID LEVEL TROUGH FROM
THE APPALACHIAN SPINE SAT MORNING TO THE COAST BY EVENING...BUT
ASSOCIATED FORECAST VERTICAL MOTION WITH THIS FEATURE IS WEAK...AND
NAM FORECAST BUFR SOUNDINGS ARE AN UNSTABLE AND UNCAPPED OUTLIER
RELATIVE TO THE GFS AND SREF ENSEMBLE MEAN. THE NAM QPF MAXIMUM FROM
SE VA THROUGH CENTRAL NC IS ALSO AN OUTLIER RELATIVE TO OTHER
GUIDANCE...WHICH OTHERWISE CONFINES ANY SHOWERS/STORMS TO THE SEA
BREEZE. WILL CONSEQUENTLY MAINTAIN JUST A SLIGHT CHANCE POP OVER THE
SOUTHERN AND CENTRAL COASTAL PLAIN...WHERE WEAK LIFT AHEAD OF THE
AFOREMENTIONED TROUGH ALOFT WILL BE DIURNALLY MAXIMIZED AND
COINCIDENT WITH LOW LEVEL FORCING INVOF THE SEA-BREEZE/SUBSEQUENT
OUTFLOW DURING THE MID-LATE AFTERNOON.
SHORTWAVE RIDGING WILL BRIEFLY FOLLOW FOR SAT NIGHT...WITH DRY
CONDITIONS AND LOWS MAINLY IN THE LOWER 70S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 335 AM THURSDAY...
THE MEDIUM RANGE WILL BE CHARACTERIZED BY THE DEVELOPMENT OF ANOTHER
UNSEASONABLY HIGH AMPLITUDE TROUGH ALOFT FROM SOUTHEASTERN CANADA
INTO THE EASTERN US...WITH AN ASSOCIATED NEGATIVE HEIGHT OF NEARLY 3
STANDARD DEVIATIONS BELOW AVERAGE FROM THE LOWER GREAT LAKES/OHIO
VALLEY TO THE CENTRAL APPALACHIANS. PRECIPITATION CHANCES DURING THE
PERIOD WILL BE HIGHEST SUN NIGHT-MON...AS THE TROUGH AMPLIFIES
SOUTHEASTWARD AND SPREADS THE ASSOCIATED MID LEVEL HEIGHT FALLS AND
UNDERLYING LO LEVEL FRONTAL ZONE ACROSS NC.
IN FACT...THE DAY SUNDAY SHOULD BE MAINLY DRY...AND HOT AS THE MID
LEVEL RIDGE OVER THE DESERT SW AND PLAINS BUILDS BRIEFLY EAST IN
ADVANCE OF THE AMPLIFYING TROUGH ALOFT. H85 TEMPERATURES ARE
FORECAST TO SURGE...ALBEIT BRIEFLY...INTO THE 22-24 DEGREE RANGE
OVER THE CAROLINAS...SUPPORTIVE OF HIGH TEMPERATURES SOLIDLY IN THE
MIDDLE 90S. UPSTREAM PRE-FRONTAL CONVECTION AND ASSOCIATED OUTFLOW
WILL THEN LIKELY DRIFT...IN A GRADUALLY WEAKENING STATE OWING TO
NOCTURNAL COOLING...INTO THE NORTHERN AND WESTERN PIEDMONT DURING
THE EVENING AND EARLY NIGHTTIME HOURS.
THE PATTERN ON THE SYNOPTIC SCALE...CHARACTERIZED BY THE APPROACHING
STRONG TROUGH AND DOWNSTREAM JET ENTRANCE DIVERGENCE ALOFT...AND LOW
LEVEL FRONTAL FORCING...FAVORS CONSIDERABLE THUNDERSTORM COVERAGE
MON...INCLUDING SOME SEVERE OWING TO UNSEASONABLY STRONG MID LEVEL
FLOW ON THE ORDER OF 40-50 KTS. HOWEVER...PREDICTABILITY ASSOCIATED
WITH MESOSCALE INFLUENCES (IE. OUTFLOW AND CLOUD COVER) FROM EARLIER
CONVECTION SUN NIGHT COMPLICATE THE FORECAST SO PROBABILITY OF
PRECIPITATION WILL BE KEPT IN THE HIGH CHANCE RANGE FOR NOW...WITH
THE EXPECTATION THAT THESE PROBABILITIES WILL BE INCREASED OVER AT
LEAST A PORTION OF THE FORECAST AREA (LIKELY THE SOUTHEAST HALF).
THE MIDDLE OF THE WEEK SHOULD BE DRY...AND COOLER...AS POST-FRONTAL
HIGH PRESSURE BUILDS INTO THE CENTRAL APPALACHIANS...AND
PRECIPITABLE WATER VALUES FALL BELOW AN INCH OVER CENTRAL NC. HIGHS
AND LOWS ONLY IN THE LOWER TO MIDDLE 80S AND LOWER TO MIDDLE
60S...RESPECTIVELY...TUE-WED.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 130 AM THURSDAY...
VFR CONDITIONS ARE LIKELY TO DOMINATE THROUGH DAYBREAK AT ALL TAF
SITES. A LIGHT BUT STEADY SURFACE BREEZE FROM THE SW WILL KEEP THE
LOW LEVELS STIRRED AND INHIBIT MOST FOG DEVELOPMENT... BUT A SHORT
PREDAWN PERIOD (UNDER 2 HRS) OF MVFR FOG IS NOT OUT OF THE QUESTION.
CURRENTLY ANY CLOUD COVER OVER CENTRAL NC IS LIMITED TO HIGH CLOUDS
BASED ABOVE 10 000 FT AGL MAINLY IN THE NW... AND WHILE CIGS WILL BE
DROPPING AHEAD OF THE COLD FRONT APPROACHING FROM THE NW... THEY
SHOULD STAY VFR THROUGH 13Z. SCATTERED TO NUMEROUS SHOWERS AND
STORMS ARE EXPECTED NEAR INT/GSO STARTING AROUND 13Z OR 14Z... AND
THESE COULD GENERATE MVFR CIGS/VSBYS AND ENHANCED WIND GUSTS. THESE
SHOWERS/STORMS ARE THEN EXPECTED TO AFFECT RDU AND RWI STARTING
AROUND 14Z OR 15Z... AND FAY STARTING AT 17Z OR 18Z. TOUGH CALL ON
WHEN THE STORM THREAT WILL EXIT TAF SITES... BUT VFR CONDITIONS
SHOULD RETURN SOON AFTER 22Z AT GSO... 00Z AT RDU/RWI... AND
PROBABLY NOT UNTIL AFTER 04Z AT FAY.
LOOKING BEYOND 06Z EARLY FRI MORNING... SURFACE WINDS WILL REMAIN
FAIRLY LIGHT LATE TONIGHT BUT SHIFT AROUND QUICKLY FROM WSW TO NNE
AS THE FRONT PUSHES SOUTHEAST THROUGH NC. THE FRONT WILL LIKELY SLOW
DOWN ENOUGH OVER SE NC TO KEEP A CHANCE OF SUB-VFR SHOWERS/STORMS AT
FAY THROUGH FRI AFTERNOON... BUT OTHERWISE VFR CONDITIONS ARE
EXPECTED FRI-SAT AS HIGH PRESSURE NOSES IN FROM THE NORTH. THIS
FRONT WILL SHIFT BACK NORTH AND DISSIPATE OVER THE WEEKEND WITH A
SURFACE TROUGH REFORMING OVER CENTRAL NC. AN UPPER LEVEL DISTURBANCE
AND ACCOMPANYING COLD FRONT WILL MOVE IN FROM THE NORTHWEST ON
SUNDAY... POTENTIALLY BRINGING ANOTHER ROUND OF SHOWERS/STORMS LATE
SUNDAY INTO MONDAY. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS..HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD/MWS
LONG TERM...MWS
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
330 AM EDT THU JUL 24 2014
.SYNOPSIS...A COLD FRONT WILL PUSH SOUTHEASTWARD THROUGH THE REGION
LATE TODAY THROUGH TONIGHT. THIS FRONT WILL STALL OUT NEAR THE SOUTH
CAROLINA BORDER ON FRIDAY... AS WEAK HIGH PRESSURE BUILDS IN FROM
THE NORTH. THIS FRONT WILL THEN WEAKEN AND HEAD BACK NORTH OF THE
AREA OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 320 AM THURSDAY...
IT`S LOOKING LIKE THE BROAD BROKEN BAND OF PREFRONTAL SHOWERS AND
STORMS WILL MOVE INTO AND THROUGH THE CWA FAIRLY EARLY TODAY...
DURING THE MORNING THROUGH MID AFTERNOON... WHICH WILL GREATLY CUT
DOWN ON OUR SEVERE THREAT OVER ALL BUT THE SE AND EXTREME ERN CWA.
THE LATEST SURFACE MAP SHOWS THE INCOMING SURFACE FRONT STRETCHING
ACROSS THE OH VALLEY... WITH A PREFRONTAL TROUGH EXTENDING THROUGH
CENTRAL VA AND THE NC FOOTHILLS. WE`RE ALREADY STARTING TO SEE A FEW
SHOWERS FORMING ESE OF THIS CONVECTION OVER THE EAST SLOPES... AND
THE HRRR SHOWS THIS MORE EASTERLY ACTIVITY EXPANDING AND BECOMING
THE DOMINANT PREFRONTAL CONVECTION THIS MORNING AS IT HEADS INTO THE
TRIAD REGION... EVENTUALLY SHIFTING EAST THROUGH THE PIEDMONT
THROUGH THE NOON HOUR. THE LARGER SCALE MODELS SUGGEST THIS AS
WELL... DEPICTING PRETTY GOOD COVERAGE OF PRECIP OVER NEARLY THE
ENTIRE CWA BY 18Z. GIVEN THIS TREND IN BOTH RADAR IMAGERY AND MODEL
OUTPUT... WILL FOLLOW THIS PATH AND BRING IN HIGH CHANCE TO LIKELY
POPS EARLIER THIS MORNING OVER THE WRN/NRN CWA... HIGHEST ACROSS THE
NRN HALF OF THE FORECAST AREA FROM LATE MORNING INTO EARLY
AFTERNOON. THE FOCUS OF THE GREATEST CONVECTION COVERAGE SHOULD THEN
SHIFT TO THE COASTAL PLAIN AND SANDHILLS FROM MID AFTERNOON TO EARLY
EVENING AS THE PREFRONTAL TROUGH PUSHES SOUTHEASTWARD THROUGH THE
CWA. BUT ADDITIONAL SCATTERED SHOWERS/STORMS ARE EXPECTED JUST AHEAD
OF AND WITH THE COLD FRONT ITSELF... WHICH IS EXPECTED TO REACH THE
SPINE OF THE APPALACHIANS BY 00Z THIS EVENING... PROPELLED BY
RELATIVELY COOL HIGH PRESSURE CENTERED NEAR CHICAGO. THE SOUTHEAST
MOVEMENT OF THIS FRONT IS APT TO BE SLOWED BY THREE FACTORS: THE
EXTRA EFFORT IT WILL TAKE THE DENSER HIGH PRESSURE AREA TO GET OVER
THE MOUNTAINS... A STEERING FLOW THAT WILL BE NEARLY PARALLEL TO THE
SURFACE FRONT... AND EXPECTATIONS OF SURFACE LOW PRESSURE
ENHANCEMENT OVER THE SOUTHERN FOOTHILLS TONIGHT. GIVEN THE POTENTIAL
FOR A DELAY IN THE ARRIVAL OF THE DRIER AND MORE STABLE COLUMN FROM
NW TO SE UNTIL THE OVERNIGHT HOURS... WILL HOLD CHANCE POPS THROUGH
THE MID-LATE EVENING AREAWIDE BEFORE TRENDING THEM DOWN AND OUT NW
TO SE LATE TONIGHT.
REGARDING THE RISK OF STRONG/SEVERE STORMS... AS NOTED ABOVE... THIS
RISK LOOK GREATLY LIMITED ACROSS THE NRN AND FAR WRN CWA DUE TO
CLOUD COVER AND EARLY PRECIP ARRIVAL. CHANCES ARE BETTER IN THE
SOUTHEAST AND EXTREME EAST... WHERE THE NAM DEPICTS MLCAPE NEAR 1500
J/KG LATE MORNING INTO EARLY AFTERNOON. WE`VE GOT IMPROVED DEEP
LAYER SHEAR TO 25-35 KTS AS WELL. BUT THE ENTIRE TIMING OF THIS
SYSTEM (WELL BEFORE MAX HEATING) AND EARLY CLOUD COVER SHOULD KEEP
INSTABILITY DOWN. BUT THE NRN/WRN CWA IS NOT OUT OF THE WOODS AS WE
MAY ACTUALLY HAVE A BIT MORE CONCERN LATE THIS AFTERNOON THROUGH
EARLY EVENING AHEAD OF THE FRONT... IF WE CAN GET PARTIAL CLEARING
BEHIND THIS MORNING ACTIVITY. THE GFS SHOWS INITIALLY SMALL MUCAPE
IN THE MORNING IN THE NW CWA REBOUNDING ABOVE 1000 J/KG LATE
TODAY... NOT A HUGE NUMBER OF COURSE BUT ENOUGH TO RETAIN AT LEAST
SOME CONCERN FOR A STRONG WIND-PRODUCING STORM OR TWO AREAWIDE.
WHILE CELL MOTIONS ARE EXPECTED TO BE GREATER THAN IN PREVIOUS
DAYS... WE MAY SEE TRAINING CELLS REPEATEDLY OVER THE SAME AREA...
AND A RISK OF LOCALLY HIGH RAIN TOTALS WILL PERSIST.
TEMPS SHOULD INITIALLY BE HELD DOWN BY CLOUDS AND PATCHY PRECIP THIS
MORNING... BUT ANY THIN SPOTS IN THE CLOUDS BETWEEN THIS PREFRONTAL
CONVECTION AND SHOWERS/STORMS IMMEDIATELY AHEAD OF THE FRONT WILL
PUSH TEMPS UP QUICKLY. SO STILL EXPECT HIGHS FROM 86 TO 92. LOWS
TONIGHT 66-72... STILL MUGGY ACROSS THE SE. -GIH
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 320 AM THURSDAY...
FOR FRI/FRI NIGHT: LITTLE CHANGED NEEDED TO EXISTING FORECAST. STILL
EXPECT THE FRONT TO HANG UP ACROSS THE SE CWA AND ALONG THE
CENTRAL/WRN NC/SC BORDER... AS THE 850 MB TROUGH HOLDS TO ITS NW
ACROSS FAR NRN NC. THIS WILL KEEP ENOUGH LOW LEVEL MOISTURE WHICH...
IN CONJUNCTION WITH LINGERING PW VALUES NEAR 1 INCH... NECESSITATES
A MENTION OF ISOLATED TO SCATTERED SHOWERS AND STORMS OVER THE FAR
SE CWA... FOCUSED ON THE TYPICAL AFTERNOON THROUGH EARLY EVENING
TIME FRAME. MUCH LOWER PW OVER THE REMAINDER OF THE CWA AND MODEST
RISE IN HEIGHTS AS THE MID LEVEL TROUGH WEAKENS AND STARTS TO PULL
AWAY WILL LEAD TO MAINLY DRY WEATHER ELSEWHERE... ALTHOUGH ONE LAST
SHOT OF DPVA THROUGH THE EXITING TROUGH BASE WILL DELAY THE MOST
SUBSTANTIAL NW-TO-SE CLEARING UNTIL LATE IN THE DAY. HIGHS 85-90...
WITH THICKNESSES SLIPPING TO 10-15 M BELOW NORMAL. LOWS 65-71. -GIH
SAT AND SAT NIGHT: THE REMNANT FRONT FROM EARLY IN THE PERIOD WILL
BECOME INCREASINGLY DIFFUSE AS IT RETREATS NORTH ACROSS THE MIDDLE
ATLANTIC STATES ON SAT...WITH A PRIMARY IMPACT FOR CENTRAL NC BEING
THE DEVELOPMENT OF A WARMING SOUTHERLY FLOW - HIGH TEMPERATURES
GENERALLY BETWEEN 89 AND 93 DEGREES. ALOFT...MODEL GUIDANCE IS IN
GOOD AGREEMENT REGARDING THE PROGRESSION OF A MID LEVEL TROUGH FROM
THE APPALACHIAN SPINE SAT MORNING TO THE COAST BY EVENING...BUT
ASSOCIATED FORECAST VERTICAL MOTION WITH THIS FEATURE IS WEAK...AND
NAM FORECAST BUFR SOUNDINGS ARE AN UNSTABLE AND UNCAPPED OUTLIER
RELATIVE TO THE GFS AND SREF ENSEMBLE MEAN. THE NAM QPF MAXIMUM FROM
SE VA THROUGH CENTRAL NC IS ALSO AN OUTLIER RELATIVE TO OTHER
GUIDANCE...WHICH OTHERWISE CONFINES ANY SHOWERS/STORMS TO THE SEA
BREEZE. WILL CONSEQUENTLY MAINTAIN JUST A SLIGHT CHANCE POP OVER THE
SOUTHERN AND CENTRAL COASTAL PLAIN...WHERE WEAK LIFT AHEAD OF THE
AFOREMENTIONED TROUGH ALOFT WILL BE DIURNALLY MAXIMIZED AND
COINCIDENT WITH LOW LEVEL FORCING INVOF THE SEA-BREEZE/SUBSEQUENT
OUTFLOW DURING THE MID-LATE AFTERNOON.
SHORTWAVE RIDGING WILL BRIEFLY FOLLOW FOR SAT NIGHT...WITH DRY
CONDITIONS AND LOWS MAINLY IN THE LOWER 70S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 235 PM WEDNESDAY...
THE NEXT UPPER TROUGH APPROACHES FROM THE NORTHWEST ON SUNDAY WITH A
COLD FRONT DROPPING ACROSS THE OH VALLEY. A LEE TROUGH AHEAD OF THE
FRONT ACROSS THE PIEDMONT OF VA AND THE CAROLINAS IS EXPECTED TO
BECOME CONVECTIVELY ACTIVE DURING THE AFTERNOON AND EVENING WITH
SCATTERED CONVECTION. THE SOUTHERLY FLOW AHEAD OF THE UPPER
TROUGH... COMBINED WITH DEEP MIXING WILL RESULT IN HIGHS IN THE
LOWER 90S. THE UPPER TROUGH AXIS AND COLD FRONT WILL CROSS CENTRAL
NC ON MONDAY WITH GOOD CONVECTIVE COVERAGE ANTICIPATED. WILL
INCREASE POPS INTO THE HIGH CHANCE RANGE. WITH THE APPROACHING
TROUGH...THE LOW AND MID LEVEL FLOW INCREASES WITH BULK SHEAR VALUES
OF 30-40 KTS EXPECTED SUGGESTING SOME HIGH-BASED STORM ORGANIZATION
IS POSSIBLE. SLIGHTLY COOLER TEMPERATURES ARE EXPECTED ON MONDAY
WITH THE CLOUD COVER AND PRECIPITATION...HIGHS SHOULD RANGE IN THE
86 TO 91 RANGE WITH LOWS MONDAY MORNING IN THE 69 TO 74 RANGE.
THE LARGE AMPLITUDE UPPER LEVEL TROUGH SLOWLY MOVES EAST ON TUESDAY
WITH THE COLD FRONT PROGGED TO MOVE INTO THE COASTAL PLAIN MONDAY
NIGHT AND SLOWLY PUSH TOWARD THE COAST ON TUESDAY. COOL HIGH
PRESSURE BUILDS INTO THE REGION WITH ANY PRECIPITATION ON TUESDAY
LIKELY CONFINED TO THE COASTAL PLAIN AND POINTS EAST. MAINLY DRY
CONDITIONS ARE EXPECTED ON WEDNESDAY BUT IT IS WORTH NOTING THAT THE
GFS/ECMWF BOTH INDICATE THE STALLED FRONT NEAR THE COAST MAY TRY TO
WORK WEST. FOR NOW WILL INCLUDE A DRY FORECAST. THE MUCH COOLER AIR
MASS WITH LOW LEVEL THICKNESS VALUES FALLING INTO THE 1375-1390M
RANGE FOR TUESDAY AND WEDNESDAY MORNINGS. THIS WOULD SUPPORT LOWS IN
THE 60S AND PERHAPS UPPER 50S IN THE TRIAD OR NEAR THE VA BORDER ON
WEDNESDAY MORNING WITH HIGHS OF 79-86. -BLAES
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 130 AM THURSDAY...
VFR CONDITIONS ARE LIKELY TO DOMINATE THROUGH DAYBREAK AT ALL TAF
SITES. A LIGHT BUT STEADY SURFACE BREEZE FROM THE SW WILL KEEP THE
LOW LEVELS STIRRED AND INHIBIT MOST FOG DEVELOPMENT... BUT A SHORT
PREDAWN PERIOD (UNDER 2 HRS) OF MVFR FOG IS NOT OUT OF THE QUESTION.
CURRENTLY ANY CLOUD COVER OVER CENTRAL NC IS LIMITED TO HIGH CLOUDS
BASED ABOVE 10 000 FT AGL MAINLY IN THE NW... AND WHILE CIGS WILL BE
DROPPING AHEAD OF THE COLD FRONT APPROACHING FROM THE NW... THEY
SHOULD STAY VFR THROUGH 13Z. SCATTERED TO NUMEROUS SHOWERS AND
STORMS ARE EXPECTED NEAR INT/GSO STARTING AROUND 13Z OR 14Z... AND
THESE COULD GENERATE MVFR CIGS/VSBYS AND ENHANCED WIND GUSTS. THESE
SHOWERS/STORMS ARE THEN EXPECTED TO AFFECT RDU AND RWI STARTING
AROUND 14Z OR 15Z... AND FAY STARTING AT 17Z OR 18Z. TOUGH CALL ON
WHEN THE STORM THREAT WILL EXIT TAF SITES... BUT VFR CONDITIONS
SHOULD RETURN SOON AFTER 22Z AT GSO... 00Z AT RDU/RWI... AND
PROBABLY NOT UNTIL AFTER 04Z AT FAY.
LOOKING BEYOND 06Z EARLY FRI MORNING... SURFACE WINDS WILL REMAIN
FAIRLY LIGHT LATE TONIGHT BUT SHIFT AROUND QUICKLY FROM WSW TO NNE
AS THE FRONT PUSHES SOUTHEAST THROUGH NC. THE FRONT WILL LIKELY SLOW
DOWN ENOUGH OVER SE NC TO KEEP A CHANCE OF SUB-VFR SHOWERS/STORMS AT
FAY THROUGH FRI AFTERNOON... BUT OTHERWISE VFR CONDITIONS ARE
EXPECTED FRI-SAT AS HIGH PRESSURE NOSES IN FROM THE NORTH. THIS
FRONT WILL SHIFT BACK NORTH AND DISSIPATE OVER THE WEEKEND WITH A
SURFACE TROUGH REFORMING OVER CENTRAL NC. AN UPPER LEVEL DISTURBANCE
AND ACCOMPANYING COLD FRONT WILL MOVE IN FROM THE NORTHWEST ON
SUNDAY... POTENTIALLY BRINGING ANOTHER ROUND OF SHOWERS/STORMS LATE
SUNDAY INTO MONDAY. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS..HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD/MWS
LONG TERM...BLAES
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
324 AM EDT THU JUL 24 2014
.SYNOPSIS...A COLD FRONT WILL PUSH SOUTHEASTWARD THROUGH THE REGION
LATE TODAY THROUGH TONIGHT. THIS FRONT WILL STALL OUT NEAR THE SOUTH
CAROLINA BORDER ON FRIDAY... AS WEAK HIGH PRESSURE BUILDS IN FROM
THE NORTH. THIS FRONT WILL THEN WEAKEN AND HEAD BACK NORTH OF THE
AREA OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 320 AM THURSDAY...
IT`S LOOKING LIKE THE BROAD BROKEN BAND OF PREFRONTAL SHOWERS AND
STORMS WILL MOVE INTO AND THROUGH THE CWA FAIRLY EARLY TODAY...
DURING THE MORNING THROUGH MID AFTERNOON... WHICH WILL GREATLY CUT
DOWN ON OUR SEVERE THREAT OVER ALL BUT THE SE AND EXTREME ERN CWA.
THE LATEST SURFACE MAP SHOWS THE INCOMING SURFACE FRONT STRETCHING
ACROSS THE OH VALLEY... WITH A PREFRONTAL TROUGH EXTENDING THROUGH
CENTRAL VA AND THE NC FOOTHILLS. WE`RE ALREADY STARTING TO SEE A FEW
SHOWERS FORMING ESE OF THIS CONVECTION OVER THE EAST SLOPES... AND
THE HRRR SHOWS THIS MORE EASTERLY ACTIVITY EXPANDING AND BECOMING
THE DOMINANT PREFRONTAL CONVECTION THIS MORNING AS IT HEADS INTO THE
TRIAD REGION... EVENTUALLY SHIFTING EAST THROUGH THE PIEDMONT
THROUGH THE NOON HOUR. THE LARGER SCALE MODELS SUGGEST THIS AS
WELL... DEPICTING PRETTY GOOD COVERAGE OF PRECIP OVER NEARLY THE
ENTIRE CWA BY 18Z. GIVEN THIS TREND IN BOTH RADAR IMAGERY AND MODEL
OUTPUT... WILL FOLLOW THIS PATH AND BRING IN HIGH CHANCE TO LIKELY
POPS EARLIER THIS MORNING OVER THE WRN/NRN CWA... HIGHEST ACROSS THE
NRN HALF OF THE FORECAST AREA FROM LATE MORNING INTO EARLY
AFTERNOON. THE FOCUS OF THE GREATEST CONVECTION COVERAGE SHOULD THEN
SHIFT TO THE COASTAL PLAIN AND SANDHILLS FROM MID AFTERNOON TO EARLY
EVENING AS THE PREFRONTAL TROUGH PUSHES SOUTHEASTWARD THROUGH THE
CWA. BUT ADDITIONAL SCATTERED SHOWERS/STORMS ARE EXPECTED JUST AHEAD
OF AND WITH THE COLD FRONT ITSELF... WHICH IS EXPECTED TO REACH THE
SPINE OF THE APPALACHIANS BY 00Z THIS EVENING... PROPELLED BY
RELATIVELY COOL HIGH PRESSURE CENTERED NEAR CHICAGO. THE SOUTHEAST
MOVEMENT OF THIS FRONT IS APT TO BE SLOWED BY THREE FACTORS: THE
EXTRA EFFORT IT WILL TAKE THE DENSER HIGH PRESSURE AREA TO GET OVER
THE MOUNTAINS... A STEERING FLOW THAT WILL BE NEARLY PARALLEL TO THE
SURFACE FRONT... AND EXPECTATIONS OF SURFACE LOW PRESSURE
ENHANCEMENT OVER THE SOUTHERN FOOTHILLS TONIGHT. GIVEN THE POTENTIAL
FOR A DELAY IN THE ARRIVAL OF THE DRIER AND MORE STABLE COLUMN FROM
NW TO SE UNTIL THE OVERNIGHT HOURS... WILL HOLD CHANCE POPS THROUGH
THE MID-LATE EVENING AREAWIDE BEFORE TRENDING THEM DOWN AND OUT NW
TO SE LATE TONIGHT.
REGARDING THE RISK OF STRONG/SEVERE STORMS... AS NOTED ABOVE... THIS
RISK LOOK GREATLY LIMITED ACROSS THE NRN AND FAR WRN CWA DUE TO
CLOUD COVER AND EARLY PRECIP ARRIVAL. CHANCES ARE BETTER IN THE
SOUTHEAST AND EXTREME EAST... WHERE THE NAM DEPICTS MLCAPE NEAR 1500
J/KG LATE MORNING INTO EARLY AFTERNOON. WE`VE GOT IMPROVED DEEP
LAYER SHEAR TO 25-35 KTS AS WELL. BUT THE ENTIRE TIMING OF THIS
SYSTEM (WELL BEFORE MAX HEATING) AND EARLY CLOUD COVER SHOULD KEEP
INSTABILITY DOWN. BUT THE NRN/WRN CWA IS NOT OUT OF THE WOODS AS WE
MAY ACTUALLY HAVE A BIT MORE CONCERN LATE THIS AFTERNOON THROUGH
EARLY EVENING AHEAD OF THE FRONT... IF WE CAN GET PARTIAL CLEARING
BEHIND THIS MORNING ACTIVITY. THE GFS SHOWS INITIALLY SMALL MUCAPE
IN THE MORNING IN THE NW CWA REBOUNDING ABOVE 1000 J/KG LATE
TODAY... NOT A HUGE NUMBER OF COURSE BUT ENOUGH TO RETAIN AT LEAST
SOME CONCERN FOR A STRONG WIND-PRODUCING STORM OR TWO AREAWIDE.
TEMPS SHOULD INITIALLY BE HELD DOWN BY CLOUDS AND PATCHY PRECIP THIS
MORNING... BUT ANY THIN SPOTS IN THE CLOUDS BETWEEN THIS PREFRONTAL
CONVECTION AND SHOWERS/STORMS IMMEDIATELY AHEAD OF THE FRONT WILL
PUSH TEMPS UP QUICKLY. SO STILL EXPECT HIGHS FROM 86 TO 92. LOWS
TONIGHT 66-72... STILL MUGGY ACROSS THE SE. -GIH
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 320 AM THURSDAY...
FRI-FRI NIGHT TO BE UPDATED...
SAT AND SAT NIGHT: THE REMNANT FRONT FROM EARLY IN THE PERIOD WILL
BECOME INCREASINGLY DIFFUSE AS IT RETREATS NORTH ACROSS THE MIDDLE
ATLANTIC STATES ON SAT...WITH A PRIMARY IMPACT FOR CENTRAL NC BEING
THE DEVELOPMENT OF A WARMING SOUTHERLY FLOW - HIGH TEMPERATURES
GENERALLY BETWEEN 89 AND 93 DEGREES. ALOFT...MODEL GUIDANCE IS IN
GOOD AGREEMENT REGARDING THE PROGRESSION OF A MID LEVEL TROUGH FROM
THE APPALACHIAN SPINE SAT MORNING TO THE COAST BY EVENING...BUT
ASSOCIATED FORECAST VERTICAL MOTION WITH THIS FEATURE IS WEAK...AND
NAM FORECAST BUFR SOUNDINGS ARE AN UNSTABLE AND UNCAPPED OUTLIER
RELATIVE TO THE GFS AND SREF ENSEMBLE MEAN. THE NAM QPF MAXIMUM FROM
SE VA THROUGH CENTRAL NC IS ALSO AN OUTLIER RELATIVE TO OTHER
GUIDANCE...WHICH OTHERWISE CONFINES ANY SHOWERS/STORMS TO THE SEA
BREEZE. WILL CONSEQUENTLY MAINTAIN JUST A SLIGHT CHANCE POP OVER THE
SOUTHERN AND CENTRAL COASTAL PLAIN...WHERE WEAK LIFT AHEAD OF THE
AFOREMENTIONED TROUGH ALOFT WILL BE DIURNALLY MAXIMIZED AND
COINCIDENT WITH LOW LEVEL FORCING INVOF THE SEA-BREEZE/SUBSEQUENT
OUTFLOW DURING THE MID-LATE AFTERNOON.
SHORTWAVE RIDGING WILL BRIEFLY FOLLOW FOR SAT NIGHT...WITH DRY
CONDITIONS AND LOWS MAINLY IN THE LOWER 70S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 235 PM WEDNESDAY...
THE NEXT UPPER TROUGH APPROACHES FROM THE NORTHWEST ON SUNDAY WITH A
COLD FRONT DROPPING ACROSS THE OH VALLEY. A LEE TROUGH AHEAD OF THE
FRONT ACROSS THE PIEDMONT OF VA AND THE CAROLINAS IS EXPECTED TO
BECOME CONVECTIVELY ACTIVE DURING THE AFTERNOON AND EVENING WITH
SCATTERED CONVECTION. THE SOUTHERLY FLOW AHEAD OF THE UPPER
TROUGH... COMBINED WITH DEEP MIXING WILL RESULT IN HIGHS IN THE
LOWER 90S. THE UPPER TROUGH AXIS AND COLD FRONT WILL CROSS CENTRAL
NC ON MONDAY WITH GOOD CONVECTIVE COVERAGE ANTICIPATED. WILL
INCREASE POPS INTO THE HIGH CHANCE RANGE. WITH THE APPROACHING
TROUGH...THE LOW AND MID LEVEL FLOW INCREASES WITH BULK SHEAR VALUES
OF 30-40 KTS EXPECTED SUGGESTING SOME HIGH-BASED STORM ORGANIZATION
IS POSSIBLE. SLIGHTLY COOLER TEMPERATURES ARE EXPECTED ON MONDAY
WITH THE CLOUD COVER AND PRECIPITATION...HIGHS SHOULD RANGE IN THE
86 TO 91 RANGE WITH LOWS MONDAY MORNING IN THE 69 TO 74 RANGE.
THE LARGE AMPLITUDE UPPER LEVEL TROUGH SLOWLY MOVES EAST ON TUESDAY
WITH THE COLD FRONT PROGGED TO MOVE INTO THE COASTAL PLAIN MONDAY
NIGHT AND SLOWLY PUSH TOWARD THE COAST ON TUESDAY. COOL HIGH
PRESSURE BUILDS INTO THE REGION WITH ANY PRECIPITATION ON TUESDAY
LIKELY CONFINED TO THE COASTAL PLAIN AND POINTS EAST. MAINLY DRY
CONDITIONS ARE EXPECTED ON WEDNESDAY BUT IT IS WORTH NOTING THAT THE
GFS/ECMWF BOTH INDICATE THE STALLED FRONT NEAR THE COAST MAY TRY TO
WORK WEST. FOR NOW WILL INCLUDE A DRY FORECAST. THE MUCH COOLER AIR
MASS WITH LOW LEVEL THICKNESS VALUES FALLING INTO THE 1375-1390M
RANGE FOR TUESDAY AND WEDNESDAY MORNINGS. THIS WOULD SUPPORT LOWS IN
THE 60S AND PERHAPS UPPER 50S IN THE TRIAD OR NEAR THE VA BORDER ON
WEDNESDAY MORNING WITH HIGHS OF 79-86. -BLAES
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 130 AM THURSDAY...
VFR CONDITIONS ARE LIKELY TO DOMINATE THROUGH DAYBREAK AT ALL TAF
SITES. A LIGHT BUT STEADY SURFACE BREEZE FROM THE SW WILL KEEP THE
LOW LEVELS STIRRED AND INHIBIT MOST FOG DEVELOPMENT... BUT A SHORT
PREDAWN PERIOD (UNDER 2 HRS) OF MVFR FOG IS NOT OUT OF THE QUESTION.
CURRENTLY ANY CLOUD COVER OVER CENTRAL NC IS LIMITED TO HIGH CLOUDS
BASED ABOVE 10 000 FT AGL MAINLY IN THE NW... AND WHILE CIGS WILL BE
DROPPING AHEAD OF THE COLD FRONT APPROACHING FROM THE NW... THEY
SHOULD STAY VFR THROUGH 13Z. SCATTERED TO NUMEROUS SHOWERS AND
STORMS ARE EXPECTED NEAR INT/GSO STARTING AROUND 13Z OR 14Z... AND
THESE COULD GENERATE MVFR CIGS/VSBYS AND ENHANCED WIND GUSTS. THESE
SHOWERS/STORMS ARE THEN EXPECTED TO AFFECT RDU AND RWI STARTING
AROUND 14Z OR 15Z... AND FAY STARTING AT 17Z OR 18Z. TOUGH CALL ON
WHEN THE STORM THREAT WILL EXIT TAF SITES... BUT VFR CONDITIONS
SHOULD RETURN SOON AFTER 22Z AT GSO... 00Z AT RDU/RWI... AND
PROBABLY NOT UNTIL AFTER 04Z AT FAY.
LOOKING BEYOND 06Z EARLY FRI MORNING... SURFACE WINDS WILL REMAIN
FAIRLY LIGHT LATE TONIGHT BUT SHIFT AROUND QUICKLY FROM WSW TO NNE
AS THE FRONT PUSHES SOUTHEAST THROUGH NC. THE FRONT WILL LIKELY SLOW
DOWN ENOUGH OVER SE NC TO KEEP A CHANCE OF SUB-VFR SHOWERS/STORMS AT
FAY THROUGH FRI AFTERNOON... BUT OTHERWISE VFR CONDITIONS ARE
EXPECTED FRI-SAT AS HIGH PRESSURE NOSES IN FROM THE NORTH. THIS
FRONT WILL SHIFT BACK NORTH AND DISSIPATE OVER THE WEEKEND WITH A
SURFACE TROUGH REFORMING OVER CENTRAL NC. AN UPPER LEVEL DISTURBANCE
AND ACCOMPANYING COLD FRONT WILL MOVE IN FROM THE NORTHWEST ON
SUNDAY... POTENTIALLY BRINGING ANOTHER ROUND OF SHOWERS/STORMS LATE
SUNDAY INTO MONDAY. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS..HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...MWS
LONG TERM...BLAES
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
320 AM EDT THU JUL 24 2014
.SYNOPSIS...A COLD FRONT WILL PUSH SOUTHEASTWARD THROUGH THE REGION
LATE TODAY THROUGH TONIGHT. THIS FRONT WILL STALL OUT NEAR THE SOUTH
CAROLINA BORDER ON FRIDAY... AS WEAK HIGH PRESSURE BUILDS IN FROM
THE NORTH. THIS FRONT WILL THEN WEAKEN AND HEAD BACK NORTH OF THE
AREA OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 320 AM THURSDAY...
IT`S LOOKING LIKE THE BROAD BROKEN BAND OF PREFRONTAL SHOWERS AND
STORMS WILL MOVE INTO AND THROUGH THE CWA FAIRLY EARLY TODAY...
DURING THE MORNING THROUGH MID AFTERNOON... WHICH WILL GREATLY CUT
DOWN ON OUR SEVERE THREAT OVER ALL BUT THE SE AND EXTREME ERN CWA.
THE LATEST SURFACE MAP SHOWS THE INCOMING SURFACE FRONT STRETCHING
ACROSS THE OH VALLEY... WITH A PREFRONTAL TROUGH EXTENDING THROUGH
CENTRAL VA AND THE NC FOOTHILLS. WE`RE ALREADY STARTING TO SEE A FEW
SHOWERS FORMING ESE OF THIS CONVECTION OVER THE EAST SLOPES... AND
THE HRRR SHOWS THIS MORE EASTERLY ACTIVITY EXPANDING AND BECOMING
THE DOMINANT PREFRONTAL CONVECTION THIS MORNING AS IT HEADS INTO THE
TRIAD REGION... EVENTUALLY SHIFTING EAST THROUGH THE PIEDMONT
THROUGH THE NOON HOUR. THE LARGER SCALE MODELS SUGGEST THIS AS
WELL... DEPICTING PRETTY GOOD COVERAGE OF PRECIP OVER NEARLY THE
ENTIRE CWA BY 18Z. GIVEN THIS TREND IN BOTH RADAR IMAGERY AND MODEL
OUTPUT... WILL FOLLOW THIS PATH AND BRING IN HIGH CHANCE TO LIKELY
POPS EARLIER THIS MORNING OVER THE WRN/NRN CWA... HIGHEST ACROSS THE
NRN HALF OF THE FORECAST AREA FROM LATE MORNING INTO EARLY
AFTERNOON. THE FOCUS OF THE GREATEST CONVECTION COVERAGE SHOULD THEN
SHIFT TO THE COASTAL PLAIN AND SANDHILLS FROM MID AFTERNOON TO EARLY
EVENING AS THE PREFRONTAL TROUGH PUSHES SOUTHEASTWARD THROUGH THE
CWA. BUT ADDITIONAL SCATTERED SHOWERS/STORMS ARE EXPECTED JUST AHEAD
OF AND WITH THE COLD FRONT ITSELF... WHICH IS EXPECTED TO REACH THE
SPINE OF THE APPALACHIANS BY 00Z THIS EVENING... PROPELLED BY
RELATIVELY COOL HIGH PRESSURE CENTERED NEAR CHICAGO. THE SOUTHEAST
MOVEMENT OF THIS FRONT IS APT TO BE SLOWED BY THREE FACTORS: THE
EXTRA EFFORT IT WILL TAKE THE DENSER HIGH PRESSURE AREA TO GET OVER
THE MOUNTAINS... A STEERING FLOW THAT WILL BE NEARLY PARALLEL TO THE
SURFACE FRONT... AND EXPECTATIONS OF SURFACE LOW PRESSURE
ENHANCEMENT OVER THE SOUTHERN FOOTHILLS TONIGHT. GIVEN THE POTENTIAL
FOR A DELAY IN THE ARRIVAL OF THE DRIER AND MORE STABLE COLUMN FROM
NW TO SE UNTIL THE OVERNIGHT HOURS... WILL HOLD CHANCE POPS THROUGH
THE MID-LATE EVENING AREAWIDE BEFORE TRENDING THEM DOWN AND OUT NW
TO SE LATE TONIGHT.
REGARDING THE RISK OF STRONG/SEVERE STORMS... AS NOTED ABOVE... THIS
RISK LOOK GREATLY LIMITED ACROSS THE NRN AND FAR WRN CWA DUE TO
CLOUD COVER AND EARLY PRECIP ARRIVAL. CHANCES ARE BETTER IN THE
SOUTHEAST AND EXTREME EAST... WHERE THE NAM DEPICTS MLCAPE NEAR 1500
J/KG LATE MORNING INTO EARLY AFTERNOON. WE`VE GOT IMPROVED DEEP
LAYER SHEAR TO 25-35 KTS AS WELL. BUT THE ENTIRE TIMING OF THIS
SYSTEM (WELL BEFORE MAX HEATING) AND EARLY CLOUD COVER SHOULD KEEP
INSTABILITY DOWN. BUT THE NRN/WRN CWA IS NOT OUT OF THE WOODS AS WE
MAY ACTUALLY HAVE A BIT MORE CONCERN LATE THIS AFTERNOON THROUGH
EARLY EVENING AHEAD OF THE FRONT... IF WE CAN GET PARTIAL CLEARING
BEHIND THIS MORNING ACTIVITY. THE GFS SHOWS INITIALLY SMALL MUCAPE
IN THE MORNING IN THE NW CWA REBOUNDING ABOVE 1000 J/KG LATE
TODAY... NOT A HUGE NUMBER OF COURSE BUT ENOUGH TO RETAIN AT LEAST
SOME CONCERN FOR A STRONG WIND-PRODUCING STORM OR TWO AREAWIDE.
TEMPS SHOULD INITIALLY BE HELD DOWN BY CLOUDS AND PATCHY PRECIP THIS
MORNING... BUT ANY THIN SPOTS IN THE CLOUDS BETWEEN THIS PREFRONTAL
CONVECTION AND SHOWERS/STORMS IMMEDIATELY AHEAD OF THE FRONT WILL
PUSH TEMPS UP QUICKLY. SO STILL EXPECT HIGHS FROM 86 TO 92. LOWS
TONIGHT 66-72... STILL MUGGY ACROSS THE SE. -GIH
&&
.SHORT TERM / /...
AS OF 315 PM WEDNESDAY...
TO BE UPDATED.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 235 PM WEDNESDAY...
NWP GUIDANCE IS RELATIVELY CONSISTENT IN BRINGING THE SURFACE COLD
FRONT TO THE COASTAL PLAIN OF THE CAROLINAS BY 12 UTC FRIDAY AS THE
UPPER LEVEL TROUGH AXIS CROSSES THE APPALACHIANS. THE UPPER LEVEL
TROUGH AXIS MAKES LIMITED PROGRESS EAST ON FRIDAY AS THE NEXT
SHORTWAVE TROUGH OVER THE OH VALLEY EARLY FRIDAY SPLITS WITH ONE
PIECE OF ENERGY MOVING EAST INTO THE NORTHEAST AND THE OTHER DROPS
TOWARD THE SAVANNAH RIVER VALLEY. THE FRONT DRIFTS SOUTH AND BRIEFLY
STALLS BEFORE MOVING NORTH INTO THE MID ATLANTIC AS A WARM FRONT
SATURDAY. DEEP MOISTURE DECREASES ON FRIDAY COMPARED TO THURSDAY
WITH THE BULK OF THE MOISTURE CONFINED TO THE 925 TO 700 MB LAYER IN
A REGION OF RELATIVELY STEEP LAPSE RATES. THIS PATTERN SUGGESTS THE
BEST CONVECTIVE COVERAGE ON FRIDAY WILL BE ACROSS THE FAR SOUTHEAST
PIEDMONT AND ESPECIALLY THE COASTAL PLAIN AND EASTERN SANDHILLS
FRIDAY AFTERNOON AND EVENING. POPS IN THE SLIGHT CHANCE TO LOW
CHANCE RANGE SHOULD SUFFICE. HIGHS ON FRIDAY WILL RANGE IN THE MID
TO UPPER 80S. PARTLY CLOUDY SKIES ARE EXPECTED FRIDAY NIGHT WITH
LOWS IN THE MID 60S TO NEAR 70. SATURDAY WILL FEATURE PARTLY CLOUDY
SKIES WITH THE BULK OF THE CONVECTION SUPPRESSED TOWARD THE COAST.
THERE IS JUST A LIMITED THREAT OF PRECIPITATION IN CENTRAL NC WITH
THE BEST CHANCE OF STORMS ON SATURDAY ACROSS THE EASTERN COASTAL
PLAIN WITH ONLY SLIGHT CHANCE POPS WARRANTED. SATURDAY SHOULD
FEATURE THE FAIRER WEATHER OF THE WEEKEND WITH VERY LIMITED
PRECIPITATION COVERAGE AND NEAR SEASONABLE TEMPERATURES.
TEMPERATURES WILL MODERATE A BIT ON SATURDAY WITH HIGHS IN THE 87 TO
92 RANGE.
THE NEXT UPPER TROUGH APPROACHES FROM THE NORTHWEST ON SUNDAY WITH A
COLD FRONT DROPPING ACROSS THE OH VALLEY. A LEE TROUGH AHEAD OF THE
FRONT ACROSS THE PIEDMONT OF VA AND THE CAROLINAS IS EXPECTED TO
BECOME CONVECTIVELY ACTIVE DURING THE AFTERNOON AND EVENING WITH
SCATTERED CONVECTION. THE SOUTHERLY FLOW AHEAD OF THE UPPER
TROUGH... COMBINED WITH DEEP MIXING WILL RESULT IN HIGHS IN THE
LOWER 90S. THE UPPER TROUGH AXIS AND COLD FRONT WILL CROSS CENTRAL
NC ON MONDAY WITH GOOD CONVECTIVE COVERAGE ANTICIPATED. WILL
INCREASE POPS INTO THE HIGH CHANCE RANGE. WITH THE APPROACHING
TROUGH...THE LOW AND MID LEVEL FLOW INCREASES WITH BULK SHEAR VALUES
OF 30-40 KTS EXPECTED SUGGESTING SOME HIGH-BASED STORM ORGANIZATION
IS POSSIBLE. SLIGHTLY COOLER TEMPERATURES ARE EXPECTED ON MONDAY
WITH THE CLOUD COVER AND PRECIPITATION...HIGHS SHOULD RANGE IN THE
86 TO 91 RANGE WITH LOWS MONDAY MORNING IN THE 69 TO 74 RANGE.
THE LARGE AMPLITUDE UPPER LEVEL TROUGH SLOWLY MOVES EAST ON TUESDAY
WITH THE COLD FRONT PROGGED TO MOVE INTO THE COASTAL PLAIN MONDAY
NIGHT AND SLOWLY PUSH TOWARD THE COAST ON TUESDAY. COOL HIGH
PRESSURE BUILDS INTO THE REGION WITH ANY PRECIPITATION ON TUESDAY
LIKELY CONFINED TO THE COASTAL PLAIN AND POINTS EAST. MAINLY DRY
CONDITIONS ARE EXPECTED ON WEDNESDAY BUT IT IS WORTH NOTING THAT THE
GFS/ECMWF BOTH INDICATE THE STALLED FRONT NEAR THE COAST MAY TRY TO
WORK WEST. FOR NOW WILL INCLUDE A DRY FORECAST. THE MUCH COOLER AIR
MASS WITH LOW LEVEL THICKNESS VALUES FALLING INTO THE 1375-1390M
RANGE FOR TUESDAY AND WEDNESDAY MORNINGS. THIS WOULD SUPPORT LOWS IN
THE 60S AND PERHAPS UPPER 50S IN THE TRIAD OR NEAR THE VA BORDER ON
WEDNESDAY MORNING WITH HIGHS OF 79-86. -BLAES
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 130 AM THURSDAY...
VFR CONDITIONS ARE LIKELY TO DOMINATE THROUGH DAYBREAK AT ALL TAF
SITES. A LIGHT BUT STEADY SURFACE BREEZE FROM THE SW WILL KEEP THE
LOW LEVELS STIRRED AND INHIBIT MOST FOG DEVELOPMENT... BUT A SHORT
PREDAWN PERIOD (UNDER 2 HRS) OF MVFR FOG IS NOT OUT OF THE QUESTION.
CURRENTLY ANY CLOUD COVER OVER CENTRAL NC IS LIMITED TO HIGH CLOUDS
BASED ABOVE 10 000 FT AGL MAINLY IN THE NW... AND WHILE CIGS WILL BE
DROPPING AHEAD OF THE COLD FRONT APPROACHING FROM THE NW... THEY
SHOULD STAY VFR THROUGH 13Z. SCATTERED TO NUMEROUS SHOWERS AND
STORMS ARE EXPECTED NEAR INT/GSO STARTING AROUND 13Z OR 14Z... AND
THESE COULD GENERATE MVFR CIGS/VSBYS AND ENHANCED WIND GUSTS. THESE
SHOWERS/STORMS ARE THEN EXPECTED TO AFFECT RDU AND RWI STARTING
AROUND 14Z OR 15Z... AND FAY STARTING AT 17Z OR 18Z. TOUGH CALL ON
WHEN THE STORM THREAT WILL EXIT TAF SITES... BUT VFR CONDITIONS
SHOULD RETURN SOON AFTER 22Z AT GSO... 00Z AT RDU/RWI... AND
PROBABLY NOT UNTIL AFTER 04Z AT FAY.
LOOKING BEYOND 06Z EARLY FRI MORNING... SURFACE WINDS WILL REMAIN
FAIRLY LIGHT LATE TONIGHT BUT SHIFT AROUND QUICKLY FROM WSW TO NNE
AS THE FRONT PUSHES SOUTHEAST THROUGH NC. THE FRONT WILL LIKELY SLOW
DOWN ENOUGH OVER SE NC TO KEEP A CHANCE OF SUB-VFR SHOWERS/STORMS AT
FAY THROUGH FRI AFTERNOON... BUT OTHERWISE VFR CONDITIONS ARE
EXPECTED FRI-SAT AS HIGH PRESSURE NOSES IN FROM THE NORTH. THIS
FRONT WILL SHIFT BACK NORTH AND DISSIPATE OVER THE WEEKEND WITH A
SURFACE TROUGH REFORMING OVER CENTRAL NC. AN UPPER LEVEL DISTURBANCE
AND ACCOMPANYING COLD FRONT WILL MOVE IN FROM THE NORTHWEST ON
SUNDAY... POTENTIALLY BRINGING ANOTHER ROUND OF SHOWERS/STORMS LATE
SUNDAY INTO MONDAY. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS..HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...MLM
LONG TERM...BLAES
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
540 PM CDT THU JUL 24 2014
.UPDATE...
ISSUED AT 540 PM CDT THU JUL 24 2014
THE 20 UTC AND INCOMING 21 UTC HRRR ITERATIONS HAVE A GOOD HANDLE
ON THE CURRENT CONVECTION ACROSS EASTERN MONTANA...AND WILL LEAN
HEAVILY ON THEIR SOLUTIONS FOR THE REMAINDER OF THE EVENING AND
OVERNIGHT. DID COORDINATE WITH SPC AT 2230 UTC REGARDING A
POTENTIAL EXPANSION OF SEVERE THUNDERSTORM WATCH 439 INTO
SOUTHWEST NORTH DAKOTA AS ROBUST CONVECTION ACROSS SOUTHEAST
MONTANA CONTINUES TO PROPAGATE NORTHEAST. WILL HOLD OFF FOR
NOW AS ALL REPORTS HAVE BEEN SUB-SEVERE. HOWEVER...SHOULD
CONVECTION STRENGTHEN AS IT APPROACHES BAKER...A WATCH EXPANSION
MAY BE NEEDED.
UPDATE ISSUED AT 410 PM CDT THU JUL 24 2014
SEVERE THUNDERSTORM WATCH 439 HAS BEEN ISSUED FOR NORTHWEST NORTH
DAKOTA THROUGH 03 UTC. PER COORDINATION WITH SPC...SEVERE
CONVECTION ACROSS NORTHWEST NORTH DAKOTA WILL LIKELY HOLD OFF
UNTIL AROUND 00-01 UTC AS STORMS ACROSS NORTH CENTRAL AND NORTHEAST
MONTANA COINCIDENT WITH THE BEST UPPER LEVEL FORCING PROPAGATE
EAST INTO NORTH DAKOTA...CLOSE TO THE 19 UTC HRRR SOLUTION.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 310 PM CDT THU JUL 24 2014
SURFACE LOW OVER CENTRAL ALBERTA WITH A TROUGH EXTENDING SOUTHWARD
INTO CENTRAL/EASTERN MONTANA TO THE WYOMING/SOUTH DAKOTA BORDER. AT
UPPER LEVELS...STRONG UPPER LOW OVER CENTRAL ALBERTA WITH SOUTHWEST
FLOW ALOFT AND EMBEDDED SHORTWAVE ENERGY IMPULSES FORECAST TO MOVE
THROUGH THE UPPER LEVEL FLOW. MOST OF THE UPPER LEVEL ENERGY APPEARS
TO BE FOCUSED MORE NORTH OF THE CANADIAN BORDER...BUT PLENTY OF CAPE
AND SHEAR IN PLACE SOUTHWARD ALONG AND AHEAD OF THE SURFACE TROUGH.
MID-LEVEL CAP WAS BUILDING AHEAD OF THE TROUGH...BUT ISOLATED
ELEVATED THUNDERSTORMS HAD DEVELOPED OVER WESTERN NORTH DAKOTA AND
WERE MOVING EAST AT 30-35 MPH...LIKELY ASSOCIATED WITH WEAK UPPER
LEVEL IMPULSES IN THE UPPER FLOW - BUT NOT SURFACE-BASED.
THE MAIN ACTION IS EXPECTED LATER THIS AFTERNOON/EARLY EVENING AS
THE SURFACE TROUGH MOVES INTO WESTERN NORTH DAKOTA...AND INTO
CENTRAL NORTH DAKOTA THROUGH THE EVENING. THIS WILL BE SUPPORTED BY
MORE VIGOROUS UPPER LEVEL IMPULSES. SEVERE STORMS POSSIBLE...BUT
BEST CAPE IS ALONG AND AHEAD OF THE TROUGH...AND THE BEST SHEAR IS
RIGHT ALONG AND BEHIND THE TROUGH.
EXPECTING BEST CHANCES OF THUNDERSTORMS IN THE WEST LATE AFTERNOON
AND EARLY EVENING...AND BEST CHANCES IN THE CENTRAL FROM MID/LATE
EVENING INTO THE EARLY MORNING HOURS.
FRIDAY LOOKS DRY AND BREEZY WEST WINDS WITH HIGHS MAINLY IN THE
UPPER 70S TO MID 80S.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 310 PM CDT THU JUL 24 2014
UPPER LEVEL LOW PROPAGATING EAST ACROSS SOUTH CENTRAL
CANADA...INTO FAR SOUTHEASTERN SASKATCHEWAN BY 12Z SAT...WILL
DRAG A SURFACE COLD FRONT THROUGH THE NORTHERN PLAINS SATURDAY
MORNING...THEN A SECONDARY COLD FRONT SATURDAY AFTERNOON/EVENING
AS THE LOW CONTINUES TOWARDS NORTHWESTERN MN. UPPER LEVEL FORCING
WITH THE LOW COUPLED WITH SFC CONVERGENCE ALONG THE FRONT WILL
BOTH COMBINE WITH LINGERING BOUNDARY LAYER MOISTURE TO RESULT IN
SCATTERED SHOWERS/THUNDERSTORMS ACROSS THE NORTH SAT
MORNING...WITH COVERAGE OF PRECIPITATION SPREADING SOUTHEAST
DURING THE DAY.
SLIGHT CHANCES FOR PRECIPITATION OVER MY FAR EASTERN COUNTIES SAT
NIGHT/SUNDAY WITH THE UPPER LEVEL JET ACROSS THE MIDWEST.
STRONG SURFACE HIGH PRESSURE BUILDS INTO THE REGION SUNDAY/SUNDAY
NIGHT AHEAD OF AN UPPER LEVEL RIDGE OVER THE WESTERN CONUS...THEN
REMAINS QUASI-STATIONARY THROUGH THE DAY TUESDAY GIVING THE
NORTHERN PLAINS REGION A DRY WEATHER SPELL. BOTH THE 12Z GFS/ECMWF
INDICATE RIDGE RIDER S/WVS MOVING THROUGH THE DAKOTAS TUESDAY
NIGHT THROUGH THURSDAY. WITH THE SFC HIGH MOVING SOUTHEAST...WILL
SEE SPOTTY SHOWER/THUNDERSTORM CHANCES BEGINNING MID-WEEK.
TEMPERATURES WILL BE ON THE COOL SIDE FOR THE END OF JULY SAT-
MON...IN THE 70S...THEN WARM INTO THE 80S TUE-THURS WITH THE
BUILDING RIDGE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 540 PM CDT THU JUL 24 2014
STRONG TO SEVERE THUNDERSTORMS ALONG A FRONTAL BOUNDARY ACROSS
EASTERN MONTANA EARLY THIS EVENING WILL CONTINUE TO MOVE EAST INTO
WESTERN AND CENTRAL NORTH DAKOTA LATER THIS EVENING AND INTO THE
OVERNIGHT. VFR CONDITIONS ARE EXPECTED OUTSIDE OF THUNDERSTORMS.
SEE TAF FORECASTS FOR THUNDERSTORM TIMING AND DETAILS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...JV
LONG TERM...NH
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
410 PM CDT THU JUL 24 2014
.UPDATE...
ISSUED AT 410 PM CDT THU JUL 24 2014
SEVERE THUNDERSTORM WATCH 439 HAS BEEN ISSUED FOR NORTHWEST NORTH
DAKOTA THROUGH 03 UTC. PER COORDINATION WITH SPC...SEVERE
CONVECTION ACROSS NORTHWEST NORTH DAKOTA WILL LIKELY HOLD OFF
UNTIL AROUND 00-01 UTC AS STORMS ACROSS NORTH CENTRAL AND NORTHEAST
MONTANA COINCIDENT WITH THE BEST UPPER LEVEL FORCING PROPAGATE
EAST INTO NORTH DAKOTA...CLOSE TO THE 19 UTC HRRR SOLUTION.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 310 PM CDT THU JUL 24 2014
SURFACE LOW OVER CENTRAL ALBERTA WITH A TROUGH EXTENDING SOUTHWARD
INTO CENTRAL/EASTERN MONTANA TO THE WYOMING/SOUTH DAKOTA BORDER. AT
UPPER LEVELS...STRONG UPPER LOW OVER CENTRAL ALBERTA WITH SOUTHWEST
FLOW ALOFT AND EMBEDDED SHORTWAVE ENERGY IMPULSES FORECAST TO MOVE
THROUGH THE UPPER LEVEL FLOW. MOST OF THE UPPER LEVEL ENERGY APPEARS
TO BE FOCUSED MORE NORTH OF THE CANADIAN BORDER...BUT PLENTY OF CAPE
AND SHEAR IN PLACE SOUTHWARD ALONG AND AHEAD OF THE SURFACE TROUGH.
MID-LEVEL CAP WAS BUILDING AHEAD OF THE TROUGH...BUT ISOLATED
ELEVATED THUNDERSTORMS HAD DEVELOPED OVER WESTERN NORTH DAKOTA AND
WERE MOVING EAST AT 30-35 MPH...LIKELY ASSOCIATED WITH WEAK UPPER
LEVEL IMPULSES IN THE UPPER FLOW - BUT NOT SURFACE-BASED.
THE MAIN ACTION IS EXPECTED LATER THIS AFTERNOON/EARLY EVENING AS
THE SURFACE TROUGH MOVES INTO WESTERN NORTH DAKOTA...AND INTO
CENTRAL NORTH DAKOTA THROUGH THE EVENING. THIS WILL BE SUPPORTED BY
MORE VIGOROUS UPPER LEVEL IMPULSES. SEVERE STORMS POSSIBLE...BUT
BEST CAPE IS ALONG AND AHEAD OF THE TROUGH...AND THE BEST SHEAR IS
RIGHT ALONG AND BEHIND THE TROUGH.
EXPECTING BEST CHANCES OF THUNDERSTORMS IN THE WEST LATE AFTERNOON
AND EARLY EVENING...AND BEST CHANCES IN THE CENTRAL FROM MID/LATE
EVENING INTO THE EARLY MORNING HOURS.
FRIDAY LOOKS DRY AND BREEZY WEST WINDS WITH HIGHS MAINLY IN THE
UPPER 70S TO MID 80S.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 310 PM CDT THU JUL 24 2014
UPPER LEVEL LOW PROPAGATING EAST ACROSS SOUTH CENTRAL
CANADA...INTO FAR SOUTHEASTERN SASKATCHEWAN BY 12Z SAT...WILL
DRAG A SURFACE COLD FRONT THROUGH THE NORTHERN PLAINS SATURDAY
MORNING...THEN A SECONDARY COLD FRONT SATURDAY AFTERNOON/EVENING
AS THE LOW CONTINUES TOWARDS NORTHWESTERN MN. UPPER LEVEL FORCING
WITH THE LOW COUPLED WITH SFC CONVERGENCE ALONG THE FRONT WILL
BOTH COMBINE WITH LINGERING BOUNDARY LAYER MOISTURE TO RESULT IN
SCATTERED SHOWERS/THUNDERSTORMS ACROSS THE NORTH SAT
MORNING...WITH COVERAGE OF PRECIPITATION SPREADING SOUTHEAST
DURING THE DAY.
SLIGHT CHANCES FOR PRECIPITATION OVER MY FAR EASTERN COUNTIES SAT
NIGHT/SUNDAY WITH THE UPPER LEVEL JET ACROSS THE MIDWEST.
STRONG SURFACE HIGH PRESSURE BUILDS INTO THE REGION SUNDAY/SUNDAY
NIGHT AHEAD OF AN UPPER LEVEL RIDGE OVER THE WESTERN CONUS...THEN
REMAINS QUASI-STATIONARY THROUGH THE DAY TUESDAY GIVING THE
NORTHERN PLAINS REGION A DRY WEATHER SPELL. BOTH THE 12Z GFS/ECMWF
INDICATE RIDGE RIDER S/WVS MOVING THROUGH THE DAKOTAS TUESDAY
NIGHT THROUGH THURSDAY. WITH THE SFC HIGH MOVING SOUTHEAST...WILL
SEE SPOTTY SHOWER/THUNDERSTORM CHANCES BEGINNING MID-WEEK.
TEMPERATURES WILL BE ON THE COOL SIDE FOR THE END OF JULY SAT-
MON...IN THE 70S...THEN WARM INTO THE 80S TUE-THURS WITH THE
BUILDING RIDGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1256 PM CDT THU JUL 24 2014
MVFR CIGS LINGERING FROM KDIK TO KBIS AND KEPT THOSE CIGS IN THE
TAFS UNTIL AROUND 20Z-21Z. OTHERWISE...MAIN HAZARD TO AVIATION WILL
BE THUNDERSTORMS MAINLY IN THE LATTER PART OF THE TAF PERIOD.
MODERATE GUSTY SOUTHEAST WINDS THROUGH THE AFTERNOON AHEAD OF A LOW
PRESSURE TROUGH/FRONT THAT IS FORECAST TO ENTER FAR WESTERN NORTH
DAKOTA AROUND 22Z-00Z...THEN MOVE EAST TO KMOT/KBIS AROUND 06Z...AND
TO KJMS AROUND 09Z-12Z. THERMAL CAP AHEAD OF THE TROUGH...BUT ALONG
AND BEHIND IT THUNDERSTORM CHANCES INCREASE...ESPECIALLY ACROSS
NORTHERN ND AT KISN/KMOT. STRONG WINDS AND LARGE HAIL THE MAIN
THREAT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...JV
LONG TERM...NH
AVIATION...JV
AREA FORECAST DISCUSSION
NWS BISMARCK ND
124 AM CDT THU JUL 24 2014
.UPDATE...
ISSUED AT 104 AM CDT THU JUL 24 2014
HAVE UPDATED TO REFINE POPS.
UPDATE ISSUED AT 925 PM CDT WED JUL 23 2014
WHILE CONVECTION HAS REMAINED LOW IN COVERAGE THROUGH 230 UTC
ACROSS CENTRAL AND EASTERN MONTANA INTO SOUTHWEST
SASKATCHEWAN...IT HAS INCREASED IN INTENSITY OVER THE PAST HOUR.
SPC HAS JUST ISSUED A SEVERE THUNDERSTORM WATCH ACROSS NORTH
CENTRAL MONTANA. SEE SPC MCD 1452 FOR DETAILS REGARDING TRENDS
THROUGH 345 UTC AS STORMS PROPAGATE EAST. ALL MODEL GUIDANCE HAS
HAD A TOUGH TIME HANDLING THE CONVECTIVE SCENARIO THIS
EVENING...WITH STORMS NOW EXPECTED TO APPROACH THE NORTH DAKOTA
BORDER AROUND 07-09 UTC.
UPDATE ISSUED AT 539 PM CDT WED JUL 23 2014
NO SIGNIFICANT CHANGES WITH THIS FORECAST UPDATE. STILL MONITORING
FOR CONVECTIVE INITIATION ACROSS CENTRAL INTO EASTERN MONTANA OVER
THE NEXT ONE TO TWO HOURS. THE 20 UTC HRRR WOULD SUGGEST
MONTANA SURFACE BASED CONVECTION APPROACHING THE NORTH DAKOTA BORDER
BY 03-04 UTC...CONTINUING TO PROPAGATE INTO CENTRAL NORTH DAKOTA
BY 08-09 UTC SUSTAINED BY A 30-35 KT LOW LEVEL JET. THE BEST
CHANCE FOR LARGE HAIL AND DAMAGING WINDS ARE GENERALLY ALONG AND
WEST OF HIGHWAY 85 AS THE MONTANA CONVECTION PROPAGATES INTO
WESTERN NORTH DAKOTA.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 320 PM CDT WED JUL 23 2014
FORECAST ISSUES IN THE SHORT TERM ARE THUNDERSTORM CHANCES...AND
POSSIBILITY OF SEVERE STORMS.
CURRENTLY...SURFACE HIGH WAS OVER MANITOBA SOUTHWARD THROUGH THE RED
RIVER VALLEY...WITH LOW PRESSURE IN THE LEE OF THE ROCKIES.
SOUTHEASTERLY FLOW WAS KEEPING MOIST LOW LEVELS WITH DEWPOINTS IN
THE 60S OVER WESTERN AND CENTRAL NORTH DAKOTA. AT UPPER LEVELS...A
SHARP RIDGE WAS IN PLACE FROM SASKATCHEWAN TO THE WESTERN DAKOTAS
AND EASTERN MT/WY. BEST SHEAR AND MID LEVEL LAPSE RATES WERE OVER
THE FRONT RANGE THIS AFTERNOON...WITH MOST UNSTABLE CAPES OVER THE
FRONT RANGE INTO THE WESTERN DAKOTAS.
LATEST MODEL RUNS SUGGEST THUNDERSTORMS DEVELOPING OVER CENTRAL AND
EASTERN MONTANA THIS EVENING IN THE VICINITY OF A MID LEVEL
SHORTWAVE ENERGY IMPULSE FORECAST TO MOVE/DEVELOP INTO NORTHEASTERN
MONTANA DURING THE EVENING. ONCE CONVECTION BECOMES BETTER
ESTABLISHED...THE SCENARIO IS FOR STORMS TO MIGRATE EASTWARD INTO
WESTERN NORTH DAKOTA LATER THIS EVENING...THEN SPREAD INTO CENTRAL
NORTH DAKOTA AFTER MIDNIGHT. THE WESTERN THIRD OF NORTH DAKOTA HAS
THE BEST POTENTIAL FOR SEVERE STORMS LATE THIS EVENING INTO THE
EARLY MORNING HOURS.
ONGOING CONVECTION DAYBREAK THURSDAY OVER MUCH OF CENTRAL NORTH
DAKOTA EXPECTED TO CONTINUE MOVING EASTWARD. THEN...ATTENTION TURNS
TO THE WEST AS A SIGNIFICANT UPPER LOW EMERGES INTO THE FRONT RANGE
FROM THE ROCKIES WITH STRONG SOUTHWEST FLOW ALOFT INTO THE DAKOTAS.
AT THE SAME TIME...THE AFOREMENTIONED SURFACE LOW OVER THE FRONT
RANGE WILL HAVE MOVED/DEVELOPED EASTWARD INTO THE WESTERN DAKOTAS.
THESE INGREDIENTS WILL BE FAVORABLE FOR PLENTY OF SHEAR...CAPE
(ESPECIALLY WITH SURFACE DEWPOINTS IN THE 65 TO 70 DEGREE
RANGE)...AND UPPER LEVEL IMPULSES. GOOD CHANCE OF THUNDERSTORMS
THURSDAY AFTERNOON OVER THE WESTERN THIRD OF THE STATE. THIS WILL
CONTINUE INTO THE EVENING HOURS AS WELL...WITH SEVERE WEATHER
POSSIBLE OVER MUCH OF THE FORECAST AREA THURSDAY AFTERNOON/NIGHT.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 320 PM CDT WED JUL 23 2014
THE MAIN FEATURES IN THE LONG TERM PERIOD CONTINUE TO BE AN UPPER
LOW OFF THE WA/OR COAST AND ITS INTERACTION WITH THE DOWNSTREAM
H500 RIDGE OVER THE NORTHERN PLAINS. AS THE UPPER LOW MOVES EAST
AND FLATTENS THE RIDGE...A COLD FRONT AT THE SURFACE WILL
POSITION ITSELF ACROSS EASTERN MONTANA BY THURSDAY AFTERNOON. THE
FRONT WILL THEN PUSH EAST ACROSS NORTH DAKOTA THURSDAY
EVENING AND OVERNIGHT INTO FRIDAY MORNING. THUNDERSTORMS...A FEW
POSSIBLY SEVERE WITH STRONG WINDS AND HAIL THE MAIN THREATS WILL
ACCOMPANY THE FRONT AS IT PROGRESSES EAST THROUGH THE STATE
THURSDAY AFTERNOON AND EVENING. ON FRIDAY COOLER BUT STILL
REASONABLY MILD TEMPERATURES IN THE UPPER 70S TO LOWER 80S SHOULD
BE THE RULE. ANY SHOWERS AND ISOLATED THUNDERSTORMS SHOULD BE
LIMITED TO THE EAST. ONE MORE DAY OF SHOWERS/SCATTERED
THUNDERSTORMS ON SATURDAY AS THE SLOW MOVING UPPER LOW TRACKS
SOUTH ACROSS MINNESOTA. WHILE THE STATE WILL GENERALLY BE ON THE
DRY SIDE OF THE UPPER LOW CANT RULE OUT SHOWERS AS COOL AIR ALOFT
SHOULD SUPPORT SOME INSTABILITY...ESPECIALLY NORTH. AS THE UPPER
LOW DRIFTS EAST AND A RIDGE POPS UP IN MONTANA SUNDAY THROUGH
TUESDAY...SHOULD BE DRY WITH GENERALLY PLEASANT TEMPERATURES AND
HUMIDITY FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 104 AM CDT THU JUL 24 2014
VFR CONDITIONS OUTSIDE OF THUNDERSTORMS ARE FORECAST FOR THE 06UTC
TAF CYCLE ACROSS WESTERN AND CENTRAL NORTH DAKOTA. ISOLATED
THUNDERSTORMS IN NORTHEAST MONTANA WERE MOVING INTO NORTHWEST
NORTH DAKOTA AND WILL SPREAD EAST AND SOUTH THROUGH 12UTC. SEE
TAFS FOR TIMING AND THREAT DETAILS. ANOTHER ROUND OF STORMS IS
EXPECTED LATE THURSDAY AFTERNOON AND INTO THE EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JPM
SHORT TERM...JV
LONG TERM...NH
AVIATION...JPM
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
142 PM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST THIS MORNING AND
SHOULD MOVE ACROSS THE CAROLINAS AND NORTH GEORGIA THIS AFTERNOON
AND EVENING. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR FRIDAY
AND THE WEEKEND. ANOTHER FRONT IS EXPECTED TO PASS ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT 1230 PM...SEE NO NEED TO CHANGE MUCH IN THE VERY NEAR TERM. SBCIN
OVER THE PIEDMONT IS GONE AND CAPES ARE AROUND 2500J AND WE ARE
BEGINNING TO SEE MORE CONVECTIVE DEVELOPMENT...SO SCT-NUMEROUS
SHOWERS/THUNDERSTORMS SHOULD OCCUR BEFORE 00Z. SFC-6KM BULK SHEAR
GENERALLY IN THE 25-30KT RANGE...SO A FEW SEVERE STORMS ARE IN THE
OFFING. ADJUSTED MOST FIELDS WITH LATEST CONSSHORT RUN.
AS OF 1020 AM...14Z SFC MAP INDICATES THAT THE COLD FRONT IS STILL
WEST OF THE NC MOUNTAINS FROM FAR SW VA THROUGH EASTERN TN. AS USUAL
THE FRONTAL PASSAGE WILL BECOME MUDDLED AS IT MOVES ACROSS THE
MOUNTAINS. LOOKS LIKE THE LEE TROUGH WILL BECOME A PLAYER THIS
AFTERNOON WITH ITS LOW LEVEL CONVERGENCE TRIGGERING STORMS. THE
ACTUAL FRONT MAY NOT MAKE IT THROUGH THE AREA UNTIL THIS EVENING. IN
ANY EVENT...CURRENT SPC MESO-ANAL SHOWS PLENTY OF CAPE POOLING
ACROSS THE PIEDMONT ALREADY LATE THIS MORNING WITH SBCAPE VALUES
ALREADY OVER 2000J. CURRENT SBCIN SHOULD DISSIPATE AS BOUNDARY LAYER
CONTINUES TO WARM. HENCE...SCT-NUMEROUS THUNDERSTORMS STILL LOOK
GOOD FOR THE AFTERNOON. SPC HAS UPGRADED OUR EASTERN AREAS TO A
SLIGHT RISK. CAN`T ARGUE WITH IN THAT THERE IS A DCAPE GRADIENT IN
THAT REGION AND 0-6KM SHEAR HAS INCREASED TO 20-30KTS. HENCE...A FEW
SEVERE STORMS ARE LIKELY. ADJUSTED MOST FIELDS BASED ON LATEST
CONSSHORT RUN AND TRENDS. THAT YIELDED MAX TEMPS A COUPLE DEGREES
LOWER AS CLOUD COVER SLOWING THE TEMP RISE.
PREVIOUS DISCUSSION:
AS OF 330 AM...RECENT REGIONAL RADAR INDICATED THAT THE CONVECTION
ACROSS EASTERN TN HAS DECREASED TO ISO SHOWERS...WITH A SECONDARY
PATCH OF SHOWERS ACROSS THE SOUTHERN I-77 CORRIDOR. W/V SHOWED THE
MID LEVEL TROF AXIS WAS LOCATED ACROSS EASTERN KY/TN...SWEEPING
EAST. AT 330 AM...W/V AND RAP INDICATED THAT SEVERAL S/W EXISTED EAST
OF THE TROF AXIS...WITH STRONGER S/W ACROSS THE WESTERN OHIO RIVER
VALLEY. I ANTICIPATE THAT WIDELY SCT TO SCT SHRA WILL DRIFT OR
DEVELOP ACROSS NC MTNS EARLY THIS MORNING. BY MID DAY...THE MID
LEVEL TROF IS EXPECTED TO RIPPLE OVER THE SOUTHERN APPALACHIAN
REGION. BY 17Z...FORECAST SOUNDINGS INDICATE THAT CAPES WILL RANGE
BETWEEN 1000-1500 J/KG ACROSS THE REGION. AS WEAK MID LEVEL FORCING
REACHES THE MTNS AND FOOTHILLS EARLY THIS AFTERNOON...CONVECTION
SHOULD DEVELOP ACROSS THE EAST FACING SLOPES AND FOOTHILLS. FORECAST
SOUNDINGS INDICATE THAT THE STEERING FLOW WILL PUSH CELLS NW TO SE
ACROSS THE WESTERN CAROLINAS AND NE GEORGIA. SHEAR MAY REMAIN WEAK
THROUGH THIS AFTERNOON...BUT POSSIBLY ENOUGH TO ORGANIZE CONVECTION
INTO A BAND. ONCE DEVELOPED...THE BAND SHOULD SLIDE
QUICKLY EAST...REACHING THE CLT AREA BY LATE AFTERNOON. THESE STORMS
MAY RESULT IN STRONG TO SEVERE TSRA WIND GUSTS ACROSS PORTIONS OF
THE OF THE FORECAST AREA. IN ADDITION...DCAPE ACROSS THE EASTERN
PIEDMONT MAY RANGE FROM 500-1000 J/KG. WE WILL HIGHLIGHT IN THE HWO
THE POTENTIAL FOR DAMAGING WIND GUSTS ASSOCIATED WITH THE FORECAST
THUNDERSTORM BAND. HIGH TEMPERATURES MAY RANGE FROM 80 WITHIN THE
MTN VALLEYS NEAR 90 EAST OF I-85.
THIS EVENING...CONVECTION WILL PROPAGATE EAST...EXITING THE CWA
EARLY THIS EVENING. OVERNIGHT...CONDITIONS WILL DRY WITH CLOUD COVER
DECREASING FROM WEST TO EAST. LOW TEMPERATURES MAY RANGE 2-3 DEGREES
COOLER THAN THIS MORNING.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...THE SHORT RANGE IS SHAPING UP TO BE
RELATIVELY QUIET. THE FRONT SHOULD BE DRIVEN FAR ENOUGH S TO NOT
AFFECT THE REGION ON FRIDAY. THE UPPER TROF OVER THE EAST SHOULD
PULL OUT OR FILL A BIT ON FRIDAY INTO SATURDAY WITH WEAK SURFACE
HIGH PRESSURE MOVING OVER THE REGION. THE MODELS CONTINUE TO
ALTERNATELY DEPICT ISOLATED/WIDELY SCATTERED SHOWER DEVELOPMENT
DURING HEATING ON FRIDAY AND SATURDAY...BUT THE SITUATION DOES NOT
APPEAR TO HAVE A WHOLE LOT GOING FOR IT AS MOISTURE SHOULD BE MUCH
LESS THAN THE LAST WEEK. A FEW SHORT WAVES WILL MOVE ACROSS THE
REGION BUT THE MODELS DO NOT RESPOND TO ANY GREAT DEGREE. AT THIS
POINT...WOULD PREFER TO REMAIN OPTIMISTIC FOR THE FIRST PART OF THE
WEEKEND AND HAVE KEPT THE FCST DRY. ANY BRIEF DROP IN TEMPS ON
FRIDAY WILL BE WIPED OUT FOR SATURDAY AS THE AIR MASS MODIFIES BACK
TO NORMAL. TOWARD THE END OF THE PERIOD...THERE IS SOME POTENTIAL
FOR AN MCS OR REMNANTS TO APPROACH FROM THE W OR NW...SO A SMALL POP
WAS INTRODUCED ON THE TN BORDER.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 330 AM THURSDAY...THE MEDIUM RANGE HAS PERHAPS A BIT MORE
UNCERTAINTY THROWN IN FOR SUNDAY AND MONDAY. THE RETURN MOISTURE
DOES NOT APPEAR TO BE AS GREAT ON SUNDAY AND ANY UPPER SUPPORT FOR
CONVECTION SHOULD MOVE PAST TO THE NORTH...TO THE POINT WHERE THE
GFS/ECMWF BOTH FAIL TO DEVELOP MUCH IN THE WAY OF PRECIP. AT THE
SAME TIME...THE MODELS CONTINUE TO SUGGEST SOME SORT OF MCS
ACTIVITY...BUT KEEP IT MOVING ACROSS THE OH VALLEY/CENTRAL
APPALACHIANS. THERE IS THE POTENTIAL FOR A BOUNDARY TO MOVE DOWN
FROM THAT ACTIVITY WHICH COULD TRIGGER SOME STORMS. WILL NOT MAKE
ANY CHANGES TO THE PRECIP PROBS FOR SUNDAY...BUT KEEP IN MIND THE
TREND IS FOR LESS ACTIVITY ON THAT DAY. THE MODELS CONTINUE TO
DEEPEN THE UPPER TROF OVER THE EAST AGAIN ON MONDAY WITH STRONGER
WAVES DRIVING ANOTHER SURFACE COLD FRONT SE ACROSS THE REGION...MOST
LIKELY ON MONDAY. IN SPITE OF THIS BOUNDARY BEING MORE SIGNIFICANT
IN TERMS OF AIR MASS CHANGE...THE MODEL RESPONSE IS UNDERWHELMING IN
TERMS OF PRECIP. AGAIN...WILL NOT MAKE ANY CHANGES...BUT A DOWNWARD
TREND MIGHT BE STARTED LATER TODAY. STILL LOOKS BELOW NORMAL FOR THE
MIDDLE OF NEXT WEEK AS A SURFACE HIGH OF CONTINENTAL ORIGIN DROPS
DOWN FROM CANADA/NRN PLAINS. HAVE NUDGED TEMPS/DEWPTS DOWN A BIT
MORE FOR TUESDAY NIGHT INTO WEDNESDAY.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AT KCLT...A COLD FRONT APPROACHING ALONG WITH AN UPPER TROUGH SHOULD
TRIGGER NUMEROUS SHOWERS/THUNDERSTORMS NEAR AND/OR OVER THE AIRFIELD
THIS AFTERNOON. HENCE...HAVE A TEMPO FOR TSRA WITH RESTRICTIONS AND GUSTY
WINDS UNTIL 23Z. THINGS WILL CALM DOWN OVERNIGHT. HOWEVER...MOST
GUIDANCE SUGGESTS THAT MVFR CLOUDS WILL DEVELOP TOWARD SUNRISE WITH
SOME LIGHT FOG. THIS SHOULD DISSIPATE BY 14Z.
ELSEWHERE...ALL TERMINALS WILL LIKELY SEE THUNDERSTORMS WITH
RESTRICTIONS AND GUSTY WINDS THIS AFTERNOON AS A COLD FRONT MOVES
INTO THE AREA. THE STORMS WILL MOVE OUT OF THE AREA THIS EVENING.
THE OVERNIGHT WILL QUIET DOWN BUT SOME IFR FOG IS A GOOD BET AT KAVL
WHERE CROSS OVER OVER TEMP WILL BE MET.
OUTLOOK...FRI NIGHT THROUGH SUNDAY MORNING SHOULD BE QUIET AND
VFR...EXCEPT FOR THE MTN VALLEYS WHERE EARLY MORNING FOG MAY OCCUR.
THUNDERSTORMS WILL RETURN TO THE FORECAST FOR SUNDAY AFTERNOON
THROUGH MON AS ANOTHER COLD FRONT APPROACHES AND THEN MOVES THROUGH
THE AREA ON MON.
CONFIDENCE TABLE...
17-23Z 23-05Z 05-11Z 11-17Z
KCLT HIGH 100% HIGH 85% HIGH 84% MED 69%
KGSP HIGH 95% HIGH 93% HIGH 100% HIGH 100%
KAVL HIGH 85% HIGH 83% MED 64% HIGH 88%
KHKY HIGH 84% HIGH 93% HIGH 100% HIGH 100%
KGMU HIGH 95% HIGH 93% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% MED 75%
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...PM
NEAR TERM...LG
SHORT TERM...PM
LONG TERM...PM
AVIATION...LG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1238 PM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST THIS MORNING AND
SHOULD MOVE ACROSS THE CAROLINAS AND NORTH GEORGIA THIS AFTERNOON
AND EVENING. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR FRIDAY
AND THE WEEKEND. ANOTHER FRONT IS EXPECTED TO PASS ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT 1230 PM...SEE NO NEED TO CHANGE MUCH IN THE VERY NEAR TERM. SBCIN
OVER THE PIEDMONT IS GONE AND CAPES ARE AROUND 2500J SO WE ARE
BEGINNING TO SEE MORE CONVECTIVE DEVELOPMENT...SO SCT-NUMEROUS
SHOWERS/THUNDERSTORMS SHOULD OCCUR BEFORE 00Z. SFC-6KM BULK SHEAR
GENERALLY IN THE 25-30KT RANGE...SO A FEW SEVERE STROMS ARE IN THE
OFFING. ADJUSTED MOST FIELDS WITH LATEST CONSSHORT RUN.
AS OF 1020 AM...14Z SFC MAP INDICATES THAT THE COLD FRONT IS STILL
WEST OF THE NC MOUNTAINS FROM FAR SW VA THROUGH EASTERN TN. AS USUAL
THE FRONTAL PASSAGE WILL BECOME MUDDLED AS IT MOVES ACROSS THE
MOUNTAINS. LOOKS LIKE THE LEE TROUGH WILL BECOME A PLAYER THIS
AFTERNOON WITH ITS LOW LEVEL CONVERGENCE TRIGGERING STORMS. THE
ACTUAL FRONT MAY NOT MAKE IT THROUGH THE AREA UNTIL THIS EVENING. IN
ANY EVENT...CURRENT SPC MESO-ANAL SHOWS PLENTY OF CAPE POOLING
ACROSS THE PIEDMONT ALREADY LATE THIS MORNING WITH SBCAPE VALUES
ALREADY OVER 2000J. CURRENT SBCIN SHOULD DISSIPATE AS BOUNDARY LAYER
CONTINUES TO WARM. HENCE...SCT-NUMEROUS THUNDERSTORMS STILL LOOK
GOOD FOR THE AFTERNOON. SPC HAS UPGRADED OUR EASTERN AREAS TO A
SLIGHT RISK. CAN`T ARGUE WITH IN THAT THERE IS A DCAPE GRADIENT IN
THAT REGION AND 0-6KM SHEAR HAS INCREASED TO 20-30KTS. HENCE...A FEW
SEVERE STORMS ARE LIKELY. ADJUSTED MOST FIELDS BASED ON LATEST
CONSSHORT RUN AND TRENDS. THAT YIELDED MAX TEMPS A COUPLE DEGREES
LOWER AS CLOUD COVER SLOWING THE TEMP RISE.
PREVIOUS DISCUSSION:
AS OF 330 AM...RECENT REGIONAL RADAR INDICATED THAT THE CONVECTION
ACROSS EASTERN TN HAS DECREASED TO ISO SHOWERS...WITH A SECONDARY
PATCH OF SHOWERS ACROSS THE SOUTHERN I-77 CORRIDOR. W/V SHOWED THE
MID LEVEL TROF AXIS WAS LOCATED ACROSS EASTERN KY/TN...SWEEPING
EAST. AT 330 AM...W/V AND RAP INDICATED THAT SEVERAL S/W EXISTED EAST
OF THE TROF AXIS...WITH STRONGER S/W ACROSS THE WESTERN OHIO RIVER
VALLEY. I ANTICIPATE THAT WIDELY SCT TO SCT SHRA WILL DRIFT OR
DEVELOP ACROSS NC MTNS EARLY THIS MORNING. BY MID DAY...THE MID
LEVEL TROF IS EXPECTED TO RIPPLE OVER THE SOUTHERN APPALACHIAN
REGION. BY 17Z...FORECAST SOUNDINGS INDICATE THAT CAPES WILL RANGE
BETWEEN 1000-1500 J/KG ACROSS THE REGION. AS WEAK MID LEVEL FORCING
REACHES THE MTNS AND FOOTHILLS EARLY THIS AFTERNOON...CONVECTION
SHOULD DEVELOP ACROSS THE EAST FACING SLOPES AND FOOTHILLS. FORECAST
SOUNDINGS INDICATE THAT THE STEERING FLOW WILL PUSH CELLS NW TO SE
ACROSS THE WESTERN CAROLINAS AND NE GEORGIA. SHEAR MAY REMAIN WEAK
THROUGH THIS AFTERNOON...BUT POSSIBLY ENOUGH TO ORGANIZE CONVECTION
INTO A BAND. ONCE DEVELOPED...THE BAND SHOULD SLIDE
QUICKLY EAST...REACHING THE CLT AREA BY LATE AFTERNOON. THESE STORMS
MAY RESULT IN STRONG TO SEVERE TSRA WIND GUSTS ACROSS PORTIONS OF
THE OF THE FORECAST AREA. IN ADDITION...DCAPE ACROSS THE EASTERN
PIEDMONT MAY RANGE FROM 500-1000 J/KG. WE WILL HIGHLIGHT IN THE HWO
THE POTENTIAL FOR DAMAGING WIND GUSTS ASSOCIATED WITH THE FORECAST
THUNDERSTORM BAND. HIGH TEMPERATURES MAY RANGE FROM 80 WITHIN THE
MTN VALLEYS NEAR 90 EAST OF I-85.
THIS EVENING...CONVECTION WILL PROPAGATE EAST...EXITING THE CWA
EARLY THIS EVENING. OVERNIGHT...CONDITIONS WILL DRY WITH CLOUD COVER
DECREASING FROM WEST TO EAST. LOW TEMPERATURES MAY RANGE 2-3 DEGREES
COOLER THAN THIS MORNING.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...THE SHORT RANGE IS SHAPING UP TO BE
RELATIVELY QUIET. THE FRONT SHOULD BE DRIVEN FAR ENOUGH S TO NOT
AFFECT THE REGION ON FRIDAY. THE UPPER TROF OVER THE EAST SHOULD
PULL OUT OR FILL A BIT ON FRIDAY INTO SATURDAY WITH WEAK SURFACE
HIGH PRESSURE MOVING OVER THE REGION. THE MODELS CONTINUE TO
ALTERNATELY DEPICT ISOLATED/WIDELY SCATTERED SHOWER DEVELOPMENT
DURING HEATING ON FRIDAY AND SATURDAY...BUT THE SITUATION DOES NOT
APPEAR TO HAVE A WHOLE LOT GOING FOR IT AS MOISTURE SHOULD BE MUCH
LESS THAN THE LAST WEEK. A FEW SHORT WAVES WILL MOVE ACROSS THE
REGION BUT THE MODELS DO NOT RESPOND TO ANY GREAT DEGREE. AT THIS
POINT...WOULD PREFER TO REMAIN OPTIMISTIC FOR THE FIRST PART OF THE
WEEKEND AND HAVE KEPT THE FCST DRY. ANY BRIEF DROP IN TEMPS ON
FRIDAY WILL BE WIPED OUT FOR SATURDAY AS THE AIR MASS MODIFIES BACK
TO NORMAL. TOWARD THE END OF THE PERIOD...THERE IS SOME POTENTIAL
FOR AN MCS OR REMNANTS TO APPROACH FROM THE W OR NW...SO A SMALL POP
WAS INTRODUCED ON THE TN BORDER.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 330 AM THURSDAY...THE MEDIUM RANGE HAS PERHAPS A BIT MORE
UNCERTAINTY THROWN IN FOR SUNDAY AND MONDAY. THE RETURN MOISTURE
DOES NOT APPEAR TO BE AS GREAT ON SUNDAY AND ANY UPPER SUPPORT FOR
CONVECTION SHOULD MOVE PAST TO THE NORTH...TO THE POINT WHERE THE
GFS/ECMWF BOTH FAIL TO DEVELOP MUCH IN THE WAY OF PRECIP. AT THE
SAME TIME...THE MODELS CONTINUE TO SUGGEST SOME SORT OF MCS
ACTIVITY...BUT KEEP IT MOVING ACROSS THE OH VALLEY/CENTRAL
APPALACHIANS. THERE IS THE POTENTIAL FOR A BOUNDARY TO MOVE DOWN
FROM THAT ACTIVITY WHICH COULD TRIGGER SOME STORMS. WILL NOT MAKE
ANY CHANGES TO THE PRECIP PROBS FOR SUNDAY...BUT KEEP IN MIND THE
TREND IS FOR LESS ACTIVITY ON THAT DAY. THE MODELS CONTINUE TO
DEEPEN THE UPPER TROF OVER THE EAST AGAIN ON MONDAY WITH STRONGER
WAVES DRIVING ANOTHER SURFACE COLD FRONT SE ACROSS THE REGION...MOST
LIKELY ON MONDAY. IN SPITE OF THIS BOUNDARY BEING MORE SIGNIFICANT
IN TERMS OF AIR MASS CHANGE...THE MODEL RESPONSE IS UNDERWHELMING IN
TERMS OF PRECIP. AGAIN...WILL NOT MAKE ANY CHANGES...BUT A DOWNWARD
TREND MIGHT BE STARTED LATER TODAY. STILL LOOKS BELOW NORMAL FOR THE
MIDDLE OF NEXT WEEK AS A SURFACE HIGH OF CONTINENTAL ORIGIN DROPS
DOWN FROM CANADA/NRN PLAINS. HAVE NUDGED TEMPS/DEWPTS DOWN A BIT
MORE FOR TUESDAY NIGHT INTO WEDNESDAY.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AT KCLT...THE PRIMARY FORECAST CHALLENGE WILL BE THE TIMING OF
AFTERNOON TSRA. THE 4KM WRF AND 6Z NAM12 INDICATES THAT CONVECTION
WILL DEVELOP ACROSS THE NC FOOTHILLS BETWEEN 18Z-19Z...FORMING A
BAND. STEERING FLOW AND COLD POOL GENERATION SHOULD RESULT IN THE
BAND TO MOVE BRISKLY EAST DURING THE AFTERNOON...LIKELY PASSING
ACROSS THE CLT METRO AREA BETWEEN 20Z TO 22Z. I WILL HIGHLIGHT THE
TSRA POTENTIAL WITH A TEMPO GROUP FROM 21Z TO 24Z. ALTHOUGH FROPA
SHOULD OCCUR BETWEEN 18Z-0Z...LIGHT NORTH WINDS ARE NOT FORECAST TO
DEVELOP UNTIL THIS EVENING. THE COMBINATION OF LIGHT NORTH
WINDS...LINGERING MID LEVEL CLOUD COVER...AND 2-3 DEGREE DEWPOINT
DEPRESSIONS SHOULD FAVOR VFR CONDITIONS TONIGHT.
ELSEWHERE...ALL TERMINALS WILL LIKELY SEE CONVECTION EITHER OVER THE
TERMINAL OR VICINITY THROUGH 0Z. I WILL HIGHLIGHT THE CONVECTIVE
PERIOD WITH VCTS OR TEMPO GROUPS...GENERALLY BETWEEN 19Z-22Z. AHEAD
OF THE COLD FRONT FLOW WILL REMAIN FROM THE SOUTHWEST BETWEEN
5-10KTS. WINDS WILL VEER FROM THE NORTH THIS EVENING. KAVL COULD SEE
NNW WINDS DEVELOP THIS MORNING...REMAINING THROUGH THE REST OF THE
12Z PACKAGE. NAM CONDENSATION PRESSURE DEFICITS AND MOS INDICATES
THAT KAVL COULD SEE IFR CEILINGS DURING THE PRE DAWN HOURS FRI.
OUTLOOK...FRI AND SAT SHOULD BE QUIET AND VFR...EXCEPT FOR THE MTN
VALLEYS WHERE EARLY MORNING FOG MAY OCCUR. THUNDERSTORMS WILL RETURN
TO THE FORECAST FOR SUNDAY AFTERNOON THROUGH MON AS ANOTHER COLD
FRONT APPROACHES AND THEN MOVES THROUGH THE AREA ON MON.
CONFIDENCE TABLE...
16-22Z 22-04Z 04-10Z 10-16Z
KCLT HIGH 100% HIGH 100% HIGH 100% MED 72%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 89%
KAVL HIGH 100% HIGH 96% MED 70% HIGH 83%
KHKY HIGH 100% HIGH 100% HIGH 88% MED 63%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 89%
KAND HIGH 100% HIGH 100% HIGH 100% MED 72%
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...PM
NEAR TERM...LG
SHORT TERM...PM
LONG TERM...PM
AVIATION...NED
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
636 AM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST THIS MORNING AND
SHOULD MOVE ACROSS THE CAROLINAS AND NORTH GEORGIA THIS AFTERNOON
AND EVENING. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR FRIDAY
AND THE WEEKEND. ANOTHER FRONT IS EXPECTED TO PASS ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 520 AM...LATEST WATER VAPOR IMAGES INDICATED THAT THE MID
LEVEL TROF WAS LOCATED GENERALLY OVER THE TN/NC LINE...WITH A S/W
OVER THE PIEDMONT. KGSP AND TCLT RADAR INDICATED SHOWERS AND
THUNDERSTORMS ASSOCIATED WITH EACH FEATURE. I WILL UPDATE THE
FORECAST TO INCREASE POPS ALONG AND EAST OF THE OBSERVED CONVECTION.
OTHERWISE...THE CURRENT FORECAST APPEARS IN GREAT SHAPE.
AS OF 330 AM...RECENT REGIONAL RADAR INDICATED THAT THE CONVECTION
ACROSS EASTERN TN HAS DECREASED TO ISO SHOWERS...WITH A SECONDARY
PATCH OF SHOWERS ACROSS THE SOUTHERN I-77 CORRIDOR. W/V SHOWED THE
MID LEVEL TROF AXIS WAS LOCATED ACROSS EASTERN KY/TN...SWEEPING
EAST. AT 330 AM...W/V AND RAP INDICATED THAT SEVERAL S/W EXISTED EAST
OF THE TROF AXIS...WITH STRONGER S/W ACROSS THE WESTERN OHIO RIVER
VALLEY. I ANTICIPATE THAT WIDELY SCT TO SCT SHRA WILL DRIFT OR
DEVELOP ACROSS NC MTNS EARLY THIS MORNING. BY MID DAY...THE MID
LEVEL TROF IS EXPECTED TO RIPPLE OVER THE SOUTHERN APPALACHIAN
REGION. BY 17Z...FORECAST SOUNDINGS INDICATE THAT CAPES WILL RANGE
BETWEEN 1000-1500 J/KG ACROSS THE REGION. AS WEAK MID LEVEL FORCING
REACHES THE MTNS AND FOOTHILLS EARLY THIS AFTERNOON...CONVECTION
SHOULD DEVELOP ACROSS THE EAST FACING SLOPES AND FOOTHILLS. FORECAST
SOUNDINGS INDICATE THAT THE STEERING FLOW WILL PUSH CELLS NW TO SE
ACROSS THE WESTERN CAROLINAS AND NE GEORGIA. SHEAR MAY REMAIN WEAK
THROUGH THIS AFTERNOON...BUT POSSIBLY ENOUGH TO ORGANIZE CONVECTION
INTO A BAND. ONCE DEVELOPED...THE BAND SHOULD SLIDE
QUICKLY EAST...REACHING THE CLT AREA BY LATE AFTERNOON. THESE STORMS
MAY RESULT IN STRONG TO SEVERE TSRA WIND GUSTS ACROSS PORTIONS OF
THE OF THE FORECAST AREA. IN ADDITION...DCAPE ACROSS THE EASTERN
PIEDMONT MAY RANGE FROM 500-1000 J/KG. WE WILL HIGHLIGHT IN THE HWO
THE POTENTIAL FOR DAMAGING WIND GUSTS ASSOCIATED WITH THE FORECAST
THUNDERSTORM BAND. HIGH TEMPERATURES MAY RANGE FROM 80 WITHIN THE
MTN VALLEYS NEAR 90 EAST OF I-85.
THIS EVENING...CONVECTION WILL PROPAGATE EAST...EXITING THE CWA
EARLY THIS EVENING. OVERNIGHT...CONDITIONS WILL DRY WITH CLOUD COVER
DECREASING FROM WEST TO EAST. LOW TEMPERATURES MAY RANGE 2-3 DEGREES
COOLER THAN THIS MORNING.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...THE SHORT RANGE IS SHAPING UP TO BE
RELATIVELY QUIET. THE FRONT SHOULD BE DRIVEN FAR ENOUGH S TO NOT
AFFECT THE REGION ON FRIDAY. THE UPPER TROF OVER THE EAST SHOULD
PULL OUT OR FILL A BIT ON FRIDAY INTO SATURDAY WITH WEAK SURFACE
HIGH PRESSURE MOVING OVER THE REGION. THE MODELS CONTINUE TO
ALTERNATELY DEPICT ISOLATED/WIDELY SCATTERED SHOWER DEVELOPMENT
DURING HEATING ON FRIDAY AND SATURDAY...BUT THE SITUATION DOES NOT
APPEAR TO HAVE A WHOLE LOT GOING FOR IT AS MOISTURE SHOULD BE MUCH
LESS THAN THE LAST WEEK. A FEW SHORT WAVES WILL MOVE ACROSS THE
REGION BUT THE MODELS DO NOT RESPOND TO ANY GREAT DEGREE. AT THIS
POINT...WOULD PREFER TO REMAIN OPTIMISTIC FOR THE FIRST PART OF THE
WEEKEND AND HAVE KEPT THE FCST DRY. ANY BRIEF DROP IN TEMPS ON
FRIDAY WILL BE WIPED OUT FOR SATURDAY AS THE AIR MASS MODIFIES BACK
TO NORMAL. TOWARD THE END OF THE PERIOD...THERE IS SOME POTENTIAL
FOR AN MCS OR REMNANTS TO APPROACH FROM THE W OR NW...SO A SMALL POP
WAS INTRODUCED ON THE TN BORDER.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 330 AM THURSDAY...THE MEDIUM RANGE HAS PERHAPS A BIT MORE
UNCERTAINTY THROWN IN FOR SUNDAY AND MONDAY. THE RETURN MOISTURE
DOES NOT APPEAR TO BE AS GREAT ON SUNDAY AND ANY UPPER SUPPORT FOR
CONVECTION SHOULD MOVE PAST TO THE NORTH...TO THE POINT WHERE THE
GFS/ECMWF BOTH FAIL TO DEVELOP MUCH IN THE WAY OF PRECIP. AT THE
SAME TIME...THE MODELS CONTINUE TO SUGGEST SOME SORT OF MCS
ACTIVITY...BUT KEEP IT MOVING ACROSS THE OH VALLEY/CENTRAL
APPALACHIANS. THERE IS THE POTENTIAL FOR A BOUNDARY TO MOVE DOWN
FROM THAT ACTIVITY WHICH COULD TRIGGER SOME STORMS. WILL NOT MAKE
ANY CHANGES TO THE PRECIP PROBS FOR SUNDAY...BUT KEEP IN MIND THE
TREND IS FOR LESS ACTIVITY ON THAT DAY. THE MODELS CONTINUE TO
DEEPEN THE UPPER TROF OVER THE EAST AGAIN ON MONDAY WITH STRONGER
WAVES DRIVING ANOTHER SURFACE COLD FRONT SE ACROSS THE REGION...MOST
LIKELY ON MONDAY. IN SPITE OF THIS BOUNDARY BEING MORE SIGNIFICANT
IN TERMS OF AIR MASS CHANGE...THE MODEL RESPONSE IS UNDERWHELMING IN
TERMS OF PRECIP. AGAIN...WILL NOT MAKE ANY CHANGES...BUT A DOWNWARD
TREND MIGHT BE STARTED LATER TODAY. STILL LOOKS BELOW NORMAL FOR THE
MIDDLE OF NEXT WEEK AS A SURFACE HIGH OF CONTINENTAL ORIGIN DROPS
DOWN FROM CANADA/NRN PLAINS. HAVE NUDGED TEMPS/DEWPTS DOWN A BIT
MORE FOR TUESDAY NIGHT INTO WEDNESDAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AT KCLT...THE PRIMARY FORECAST CHALLENGE WILL BE THE TIMING OF
AFTERNOON TSRA. THE 4KM WRF AND 6Z NAM12 INDICATES THAT CONVECTION
WILL DEVELOP ACROSS THE NC FOOTHILLS BETWEEN 18Z-19Z...FORMING A
BAND. STEERING FLOW AND COLD POOL GENERATION SHOULD RESULT IN THE
BAND TO MOVE BRISKLY EAST DURING THE AFTERNOON...LIKELY PASSING
ACROSS THE CLT METRO AREA BETWEEN 20Z TO 22Z. I WILL HIGHLIGHT THE
TSRA POTENTIAL WITH A TEMPO GROUP FROM 21Z TO 24Z. ALTHOUGH FROPA
SHOULD OCCUR BETWEEN 18Z-0Z...LIGHT NORTH WINDS ARE NOT FORECAST TO
DEVELOP UNTIL THIS EVENING. THE COMBINATION OF LIGHT NORTH
WINDS...LINGERING MID LEVEL CLOUD COVER...AND 2-3 DEGREE DEWPOINT
DEPRESSIONS SHOULD FAVOR VFR CONDITIONS TONIGHT.
ELSEWHERE...ALL TERMINALS WILL LIKELY SEE CONVECTION EITHER OVER THE
TERMINAL OR VICINITY THROUGH 0Z. I WILL HIGHLIGHT THE CONVECTIVE
PERIOD WITH VCTS OR TEMPO GROUPS...GENERALLY BETWEEN 19Z-22Z. AHEAD
OF THE COLD FRONT FLOW WILL REMAIN FROM THE SOUTHWEST BETWEEN
5-10KTS. WINDS WILL VEER FROM THE NORTH THIS EVENING. KAVL COULD SEE
NNW WINDS DEVELOP THIS MORNING...REMAINING THROUGH THE REST OF THE
12Z PACKAGE. NAM CONDENSATION PRESSURE DEFICITS AND MOS INDICATES
THAT KAVL COULD SEE IFR CEILINGS DURING THE PRE DAWN HOURS FRI.
OUTLOOK...FRI AND SAT SHOULD BE QUIET AND VFR...EXCEPT FOR THE MTN
VALLEYS WHERE EARLY MORNING FOG MAY OCCUR. THUNDERSTORMS WILL RETURN
TO THE FORECAST FOR SUNDAY AFTERNOON THROUGH MON AS ANOTHER COLD
FRONT APPROACHES AND THEN MOVES THROUGH THE AREA ON MON.
CONFIDENCE TABLE...
10-16Z 16-22Z 22-04Z 04-10Z
KCLT HIGH 98% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL MED 65% HIGH 100% HIGH 92% MED 66%
KHKY HIGH 97% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...PM
NEAR TERM...NED
SHORT TERM...PM
LONG TERM...PM
AVIATION...NED
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
523 AM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST THIS MORNING AND
SHOULD MOVE ACROSS THE CAROLINAS AND NORTH GEORGIA THIS AFTERNOON
AND EVENING. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR FRIDAY
AND THE WEEKEND. ANOTHER FRONT IS EXPECTED TO PASS ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 520 AM...LATEST WATER VAPOR IMAGES INDICATED THAT THE MID
LEVEL TROF WAS LOCATED GENERALLY OVER THE TN/NC LINE...WITH A S/W
OVER THE PIEDMONT. KGSP AND TCLT RADAR INDICATED SHOWERS AND
THUNDERSTORMS ASSOCIATED WITH EACH FEATURE. I WILL UPDATE THE
FORECAST TO INCREASE POPS ALONG AND EAST OF THE OBSERVED CONVECTION.
OTHERWISE...THE CURRENT FORECAST APPEARS IN GREAT SHAPE.
AS OF 330 AM...RECENT REGIONAL RADAR INDICATED THAT THE CONVECTION
ACROSS EASTERN TN HAS DECREASED TO ISO SHOWERS...WITH A SECONDARY
PATCH OF SHOWERS ACROSS THE SOUTHERN I-77 CORRIDOR. W/V SHOWED THE
MID LEVEL TROF AXIS WAS LOCATED ACROSS EASTERN KY/TN...SWEEPING
EAST. AT 330 AM...W/V AND RAP INDICATED THAT SEVERAL S/W EXISTED EAST
OF THE TROF AXIS...WITH STRONGER S/W ACROSS THE WESTERN OHIO RIVER
VALLEY. I ANTICIPATE THAT WIDELY SCT TO SCT SHRA WILL DRIFT OR
DEVELOP ACROSS NC MTNS EARLY THIS MORNING. BY MID DAY...THE MID
LEVEL TROF IS EXPECTED TO RIPPLE OVER THE SOUTHERN APPALACHIAN
REGION. BY 17Z...FORECAST SOUNDINGS INDICATE THAT CAPES WILL RANGE
BETWEEN 1000-1500 J/KG ACROSS THE REGION. AS WEAK MID LEVEL FORCING
REACHES THE MTNS AND FOOTHILLS EARLY THIS AFTERNOON...CONVECTION
SHOULD DEVELOP ACROSS THE EAST FACING SLOPES AND FOOTHILLS. FORECAST
SOUNDINGS INDICATE THAT THE STEERING FLOW WILL PUSH CELLS NW TO SE
ACROSS THE WESTERN CAROLINAS AND NE GEORGIA. SHEAR MAY REMAIN WEAK
THROUGH THIS AFTERNOON...BUT POSSIBLY ENOUGH TO ORGANIZE CONVECTION
INTO A BAND. ONCE DEVELOPED...THE BAND SHOULD SLIDE
QUICKLY EAST...REACHING THE CLT AREA BY LATE AFTERNOON. THESE STORMS
MAY RESULT IN STRONG TO SEVERE TSRA WIND GUSTS ACROSS PORTIONS OF
THE OF THE FORECAST AREA. IN ADDITION...DCAPE ACROSS THE EASTERN
PIEDMONT MAY RANGE FROM 500-1000 J/KG. WE WILL HIGHLIGHT IN THE HWO
THE POTENTIAL FOR DAMAGING WIND GUSTS ASSOCIATED WITH THE FORECAST
THUNDERSTORM BAND. HIGH TEMPERATURES MAY RANGE FROM 80 WITHIN THE
MTN VALLEYS NEAR 90 EAST OF I-85.
THIS EVENING...CONVECTION WILL PROPAGATE EAST...EXITING THE CWA
EARLY THIS EVENING. OVERNIGHT...CONDITIONS WILL DRY WITH CLOUD COVER
DECREASING FROM WEST TO EAST. LOW TEMPERATURES MAY RANGE 2-3 DEGREES
COOLER THAN THIS MORNING.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...THE SHORT RANGE IS SHAPING UP TO BE
RELATIVELY QUIET. THE FRONT SHOULD BE DRIVEN FAR ENOUGH S TO NOT
AFFECT THE REGION ON FRIDAY. THE UPPER TROF OVER THE EAST SHOULD
PULL OUT OR FILL A BIT ON FRIDAY INTO SATURDAY WITH WEAK SURFACE
HIGH PRESSURE MOVING OVER THE REGION. THE MODELS CONTINUE TO
ALTERNATELY DEPICT ISOLATED/WIDELY SCATTERED SHOWER DEVELOPMENT
DURING HEATING ON FRIDAY AND SATURDAY...BUT THE SITUATION DOES NOT
APPEAR TO HAVE A WHOLE LOT GOING FOR IT AS MOISTURE SHOULD BE MUCH
LESS THAN THE LAST WEEK. A FEW SHORT WAVES WILL MOVE ACROSS THE
REGION BUT THE MODELS DO NOT RESPOND TO ANY GREAT DEGREE. AT THIS
POINT...WOULD PREFER TO REMAIN OPTIMISTIC FOR THE FIRST PART OF THE
WEEKEND AND HAVE KEPT THE FCST DRY. ANY BRIEF DROP IN TEMPS ON
FRIDAY WILL BE WIPED OUT FOR SATURDAY AS THE AIR MASS MODIFIES BACK
TO NORMAL. TOWARD THE END OF THE PERIOD...THERE IS SOME POTENTIAL
FOR AN MCS OR REMNANTS TO APPROACH FROM THE W OR NW...SO A SMALL POP
WAS INTRODUCED ON THE TN BORDER.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 330 AM THURSDAY...THE MEDIUM RANGE HAS PERHAPS A BIT MORE
UNCERTAINTY THROWN IN FOR SUNDAY AND MONDAY. THE RETURN MOISTURE
DOES NOT APPEAR TO BE AS GREAT ON SUNDAY AND ANY UPPER SUPPORT FOR
CONVECTION SHOULD MOVE PAST TO THE NORTH...TO THE POINT WHERE THE
GFS/ECMWF BOTH FAIL TO DEVELOP MUCH IN THE WAY OF PRECIP. AT THE
SAME TIME...THE MODELS CONTINUE TO SUGGEST SOME SORT OF MCS
ACTIVITY...BUT KEEP IT MOVING ACROSS THE OH VALLEY/CENTRAL
APPALACHIANS. THERE IS THE POTENTIAL FOR A BOUNDARY TO MOVE DOWN
FROM THAT ACTIVITY WHICH COULD TRIGGER SOME STORMS. WILL NOT MAKE
ANY CHANGES TO THE PRECIP PROBS FOR SUNDAY...BUT KEEP IN MIND THE
TREND IS FOR LESS ACTIVITY ON THAT DAY. THE MODELS CONTINUE TO
DEEPEN THE UPPER TROF OVER THE EAST AGAIN ON MONDAY WITH STRONGER
WAVES DRIVING ANOTHER SURFACE COLD FRONT SE ACROSS THE REGION...MOST
LIKELY ON MONDAY. IN SPITE OF THIS BOUNDARY BEING MORE SIGNIFICANT
IN TERMS OF AIR MASS CHANGE...THE MODEL RESPONSE IS UNDERWHELMING IN
TERMS OF PRECIP. AGAIN...WILL NOT MAKE ANY CHANGES...BUT A DOWNWARD
TREND MIGHT BE STARTED LATER TODAY. STILL LOOKS BELOW NORMAL FOR THE
MIDDLE OF NEXT WEEK AS A SURFACE HIGH OF CONTINENTAL ORIGIN DROPS
DOWN FROM CANADA/NRN PLAINS. HAVE NUDGED TEMPS/DEWPTS DOWN A BIT
MORE FOR TUESDAY NIGHT INTO WEDNESDAY.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
AT KCLT...CONDITIONS THIS MORNING WILL REMAIN LESS FAVORABLE FOR FOG
AND CIG RESTRICTIONS THAN PREVIOUS MORNINGS. I WILL FORECAST VFR
CONDITIONS TO REMAIN THROUGH THE REST OF THIS MORNING...WITH VERY
LIGHT TO CALM WINDS. THE PRIMARY FORECAST CHALLENGE WILL BE THE
TIMING OF AFTERNOON TSRA. THE 4KM WRF INDICATES THAT CONVECTION WILL
DEVELOP ACROSS THE NC FOOTHILLS BETWEEN 18Z-19Z...FORMING A BAND.
STEERING FLOW AND COLD POOL GENERATION SHOULD RESULT IN THE BAND TO
MOVE BRISKLY EAST DURING THE AFTERNOON...LIKELY PASSING ACROSS THE
CLT METRO AREA BETWEEN 20Z TO 22Z. I WILL HIGHLIGHT THE TSRA
POTENTIAL WITH A TEMPO GROUP FROM 21Z TO 24Z.
ELSEWHERE...TERMINALS EAST OF THE MTNS WILL REMAIN SIMILAR TO CLT.
KAVL WILL LIKELY SEE IFR OR LOWER CONDITIONS DURING THE PRE DAWN
HOURS...RETURNING TO VFR BY 13Z. KAVL SHOULD SEE WINDS FROM THE 330
TO 350 DEGREES THROUGH THE TAF PERIOD.
OUTLOOK...FRI AND SAT SHOULD BE QUIET AND VFR...EXCEPT FOR THE MTN
VALLEYS WHERE EARLY MORNING FOG MAY OCCUR. THUNDERSTORMS WILL RETURN
TO THE FORECAST FOR SUNDAY AFTERNOON THROUGH MON AS ANOTHER COLD
FRONT APPROACHES AND THEN MOVES THROUGH THE AREA ON MON.
CONFIDENCE TABLE...
09-15Z 15-21Z 21-03Z 03-09Z
KCLT HIGH 99% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL LOW 58% HIGH 100% HIGH 100% MED 64%
KHKY HIGH 97% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 97% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...PM
NEAR TERM...NED
SHORT TERM...PM
LONG TERM...PM
AVIATION...NED
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
347 AM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST THIS MORNING AND
SHOULD MOVE ACROSS THE CAROLINAS AND NORTH GEORGIA THIS AFTERNOON
AND EVENING. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR FRIDAY
AND THE WEEKEND. ANOTHER FRONT IS EXPECTED TO PASS ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM...RECENT REGIONAL RADAR INDICATED THAT THE CONVECTION
ACROSS EASTERN TN HAS DECREASED TO ISO SHOWERS...WITH A SECONDARY
PATCH OF SHOWERS ACROSS THE SOUTHERN I-77 CORRIDOR. W/V SHOWED THE
MID LEVEL TROF AXIS WAS LOCATED ACROSS EASTERN KY/TN...SWEEPING
EAST. AT 330 AM...W/V AND RAP INDICATED THAT SEVERAL S/W EXISTED EAST
OF THE TROF AXIS...WITH STRONGER S/W ACROSS THE WESTERN OHIO RIVER
VALLEY. I ANTICIPATE THAT WIDELY SCT TO SCT SHRA WILL DRIFT OR
DEVELOP ACROSS NC MTNS EARLY THIS MORNING. BY MID DAY...THE MID
LEVEL TROF IS EXPECTED TO RIPPLE OVER THE SOUTHERN APPALACHIAN
REGION. BY 17Z...FORECAST SOUNDINGS INDICATE THAT CAPES WILL RANGE
BETWEEN 1000-1500 J/KG ACROSS THE REGION. AS WEAK MID LEVEL FORCING
REACHES THE MTNS AND FOOTHILLS EARLY THIS AFTERNOON...CONVECTION
SHOULD DEVELOP ACROSS THE EAST FACING SLOPES AND FOOTHILLS. FORECAST
SOUNDINGS INDICATE THAT THE STEERING FLOW WILL PUSH CELLS NW TO SE
ACROSS THE WESTERN CAROLINAS AND NE GEORGIA. SHEAR MAY REMAIN WEAK
THROUGH THIS AFTERNOON...BUT POSSIBLY ENOUGH TO ORGANIZE CONVECTION
INTO A BAND. ONCE DEVELOPED...THE BAND SHOULD SLIDE
QUICKLY EAST...REACHING THE CLT AREA BY LATE AFTERNOON. THESE STORMS
MAY RESULT IN STRONG TO SEVERE TSRA WIND GUSTS ACROSS PORTIONS OF
THE OF THE FORECAST AREA. IN ADDITION...DCAPE ACROSS THE EASTERN
PIEDMONT MAY RANGE FROM 500-1000 J/KG. WE WILL HIGHLIGHT IN THE HWO
THE POTENTIAL FOR DAMAGING WIND GUSTS ASSOCIATED WITH THE FORECAST
THUNDERSTORM BAND. HIGH TEMPERATURES MAY RANGE FROM 80 WITHIN THE
MTN VALLEYS NEAR 90 EAST OF I-85.
THIS EVENING...CONVECTION WILL PROPAGATE EAST...EXITING THE CWA
EARLY THIS EVENING. OVERNIGHT...CONDITIONS WILL DRY WITH CLOUD COVER
DECREASING FROM WEST TO EAST. LOW TEMPERATURES MAY RANGE 2-3 DEGREES
COOLER THAN THIS MORNING.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...THE SHORT RANGE IS SHAPING UP TO BE
RELATIVELY QUIET. THE FRONT SHOULD BE DRIVEN FAR ENOUGH S TO NOT
AFFECT THE REGION ON FRIDAY. THE UPPER TROF OVER THE EAST SHOULD
PULL OUT OR FILL A BIT ON FRIDAY INTO SATURDAY WITH WEAK SURFACE
HIGH PRESSURE MOVING OVER THE REGION. THE MODELS CONTINUE TO
ALTERNATELY DEPICT ISOLATED/WIDELY SCATTERED SHOWER DEVELOPMENT
DURING HEATING ON FRIDAY AND SATURDAY...BUT THE SITUATION DOES NOT
APPEAR TO HAVE A WHOLE LOT GOING FOR IT AS MOISTURE SHOULD BE MUCH
LESS THAN THE LAST WEEK. A FEW SHORT WAVES WILL MOVE ACROSS THE
REGION BUT THE MODELS DO NOT RESPOND TO ANY GREAT DEGREE. AT THIS
POINT...WOULD PREFER TO REMAIN OPTIMISTIC FOR THE FIRST PART OF THE
WEEKEND AND HAVE KEPT THE FCST DRY. ANY BRIEF DROP IN TEMPS ON
FRIDAY WILL BE WIPED OUT FOR SATURDAY AS THE AIR MASS MODIFIES BACK
TO NORMAL. TOWARD THE END OF THE PERIOD...THERE IS SOME POTENTIAL
FOR AN MCS OR REMNANTS TO APPROACH FROM THE W OR NW...SO A SMALL POP
WAS INTRODUCED ON THE TN BORDER.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 330 AM THURSDAY...THE MEDIUM RANGE HAS PERHAPS A BIT MORE
UNCERTAINTY THROWN IN FOR SUNDAY AND MONDAY. THE RETURN MOISTURE
DOES NOT APPEAR TO BE AS GREAT ON SUNDAY AND ANY UPPER SUPPORT FOR
CONVECTION SHOULD MOVE PAST TO THE NORTH...TO THE POINT WHERE THE
GFS/ECMWF BOTH FAIL TO DEVELOP MUCH IN THE WAY OF PRECIP. AT THE
SAME TIME...THE MODELS CONTINUE TO SUGGEST SOME SORT OF MCS
ACTIVITY...BUT KEEP IT MOVING ACROSS THE OH VALLEY/CENTRAL
APPALACHIANS. THERE IS THE POTENTIAL FOR A BOUNDARY TO MOVE DOWN
FROM THAT ACTIVITY WHICH COULD TRIGGER SOME STORMS. WILL NOT MAKE
ANY CHANGES TO THE PRECIP PROBS FOR SUNDAY...BUT KEEP IN MIND THE
TREND IS FOR LESS ACTIVITY ON THAT DAY. THE MODELS CONTINUE TO
DEEPEN THE UPPER TROF OVER THE EAST AGAIN ON MONDAY WITH STRONGER
WAVES DRIVING ANOTHER SURFACE COLD FRONT SE ACROSS THE REGION...MOST
LIKELY ON MONDAY. IN SPITE OF THIS BOUNDARY BEING MORE SIGNIFICANT
IN TERMS OF AIR MASS CHANGE...THE MODEL RESPONSE IS UNDERWHELMING IN
TERMS OF PRECIP. AGAIN...WILL NOT MAKE ANY CHANGES...BUT A DOWNWARD
TREND MIGHT BE STARTED LATER TODAY. STILL LOOKS BELOW NORMAL FOR THE
MIDDLE OF NEXT WEEK AS A SURFACE HIGH OF CONTINENTAL ORIGIN DROPS
DOWN FROM CANADA/NRN PLAINS. HAVE NUDGED TEMPS/DEWPTS DOWN A BIT
MORE FOR TUESDAY NIGHT INTO WEDNESDAY.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
AT KCLT...CONDITIONS THIS MORNING WILL REMAIN LESS FAVORABLE FOR FOG
AND CIG RESTRICTIONS THAN PREVIOUS MORNINGS. I WILL FORECAST VFR
CONDITIONS TO REMAIN THROUGH THE REST OF THIS MORNING...WITH VERY
LIGHT TO CALM WINDS. THE PRIMARY FORECAST CHALLENGE WILL BE THE
TIMING OF AFTERNOON TSRA. THE 4KM WRF INDICATES THAT CONVECTION WILL
DEVELOP ACROSS THE NC FOOTHILLS BETWEEN 18Z-19Z...FORMING A BAND.
STEERING FLOW AND COLD POOL GENERATION SHOULD RESULT IN THE BAND TO
MOVE BRISKLY EAST DURING THE AFTERNOON...LIKELY PASSING ACROSS THE
CLT METRO AREA BETWEEN 20Z TO 22Z. I WILL HIGHLIGHT THE TSRA
POTENTIAL WITH A TEMPO GROUP FROM 21Z TO 24Z.
ELSEWHERE...TERMINALS EAST OF THE MTNS WILL REMAIN SIMILAR TO CLT.
KAVL WILL LIKELY SEE IFR OR LOWER CONDITIONS DURING THE PRE DAWN
HOURS...RETURNING TO VFR BY 13Z. KAVL SHOULD SEE WINDS FROM THE 330
TO 350 DEGREES THROUGH THE TAF PERIOD.
OUTLOOK...FRI AND SAT SHOULD BE QUIET AND VFR...EXCEPT FOR THE MTN
VALLEYS WHERE EARLY MORNING FOG MAY OCCUR. THUNDERSTORMS WILL RETURN
TO THE FORECAST FOR SUNDAY AFTERNOON THROUGH MON AS ANOTHER COLD
FRONT APPROACHES AND THEN MOVES THROUGH THE AREA ON MON.
CONFIDENCE TABLE...
07-13Z 13-19Z 19-01Z 01-07Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL MED 67% HIGH 88% HIGH 100% HIGH 80%
KHKY HIGH 100% HIGH 95% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...PM
NEAR TERM...NED
SHORT TERM...PM
LONG TERM...PM
AVIATION...NED
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1228 PM CDT THU JUL 24 2014
.UPDATE...
ISSUED AT 1121 AM CDT THU JUL 24 2014
HAVE TWEAKED POPS THIS MORNING AND RAISED THEM IN EAST CENTRAL SD...
SOUTHEASTWARD INTO PARTS OF SOUTHWEST MN AND NORTHWEST IA
ACCOUNTING FOR THE CURRENT CLUSTER OF ELEVATED STORMS MOVING
THROUGH. A FEW CELLS GET A BIT ANGRY ALOFT...BUT THEN CORES
COLLAPSE SO THUS ONLY ONE WARNING SO FAR. THE CELLS ARE ROOTED
NEAR 750MB SO THE WIND SHEAR IN MOST OF THE LOWEST 2KM IS NOT
BEING TAPPED. BUT THEY ARE HOLDING TOGETHER ALONG POSITIVE THETAE
ADVECTION AND WILL CERTAINLY IMPACT SOUTHWEST MN AND FAR NORTHWEST
IA THROUGH EARLY AFTERNOON. MORE UNCERTAIN IS WHAT THE CLUSTER IN
EASTERN ND AND EXTREME NORTHEAST SD WILL DO. HAD TO KEEP SOME
DECENT POPS GOING IN SOUTHWEST MN FOR THE MID AFTERNOON HOURS AND
MAY HAVE TO RAISE THEM IF THAT ACTIVITY HOLDS TOGETHER. HIGHS
STILL LOOK VERY WARM IN OUR FAR WEST...COOLING TO AROUND THE UPPER
70S TO NEAR 80 IN OUR EAST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 420 AM CDT THU JUL 24 2014
FAIRLY SHARP RIDGE WITH AXIS JUST EAST OF THE ROCKIES EARLY THIS
MORNING. ON WATER VAPOR LOOP...CAN SEE SEVERAL WAVES ROTATING
THROUGH THE RIDGE...ALL RIDING ON THE EDGE OF A FAIRLY STRONG MID
LEVEL FRONTAL BOUNDARY. STRONGEST WAVE BACK OVER PAC NW...BUT ONE
NICE WAVE PUSHING FROM ERN MT INTO WRN ND. PATCHY CLOUDS IN THE
9-10 KFT RANGE HAVE DEVELOPED FROM SOUTH CENTRAL ND TOWARD
SOUTHEASTERN SD...AND INCREASING LOW LEVEL JET WINDS ON MRR
PROFILER. ALL RECENT RUNS OF HRRR AND WRF-ARW HAVE BEEN FAIRLY
INSISTENT ON DEVELOPMENT OF CONVECTION OVER THE NEXT COUPLE HOURS
FROM 09Z-11Z OUT FROM THE JAMES VALLEY WESTWARD...AND MOST SOLUTION
HAVE AT LEAST SOME DEVELOPMENT OCCURRING THIS MORNING. GIVEN A DECENT
MID LEVEL THETA E ADVECTION FOCUS...AND MID LEVEL FRONTOGENETIC
AXIS...SEEMS WOULD BE FAVORED FOR A FEW STORMS DEVELOPING THIS
MORNING. HOWEVER...WILL BE INCREASINGLY DIFFICULT FOR ACTIVITY TO
BUILD EASTWARD AS FORCING WITH WEAK MID LEVEL WAVES DROPS SOUTHEAST
MOST LIKELY LOCATION FOR CONVECTION LOOKS TO BE THE MID TO SOUTHERN
JAMES VALLEY THEN SOUTHEAST TOWARD KSUX AREA DURING THE MORNING
HOURS. BY AFTERNOON...CONTINUED BUILDING HEIGHTS AND WARMING TEMPS
ALOFT AS WAVE MOVES PAST WILL START TO WEAR ON CONVECTIVE THREAT
WITH COVERAGE EXPECTED TO DWINDLE AS BUILDS EAST.
WITH ELEVATED INSTABILITY PERHAPS AS HIGH AS 1000 J/KG AND 2-6KM
SHEAR OF 30-40 KNOTS...POTENTIAL IS THERE FOR SOME ORGANIZED STORM
DEVELOPMENT AND UPDRAFT HELICITY ON HRRR INDICATES SOME NEED FOR
CONCERN FOR MARGINALLY SEVERE HAIL WITH ANY STRONGER STORMS THROUGH
AT LEAST MID TO LATE MORNING.
A PRETTY SHARP GRADIENT WILL AGAIN TODAY BE PRESENT BETWEEN WARM AND
HUMID LESS MIXED CONDITIONS...WITH A HOT...DRY...AND MORE MIXED
AIRMASS... LIKELY TO REMAIN JUST WEST OF THE CWA. HAVE RAISED TEMPS
MANY AREAS BY A COUPLE DEGREES...WITH MAINLY 80S...BUT SOME UPPER
70S IN MORE PERSISTENT CLOUDS/POTENTIAL PRECIP AXIS. HAVE LOWER 90S
CRAWLING BACK INTO THE WEST...AND WITH RECENT DRY CONDITIONS AND
WINDS GUSTING 25 TO 35 MPH...WILL START TO BRING A BIT MORE CONCERN
TO FIRE BEHAVIOR...BUT STARTS WILL STILL BE VERY DIFFICULT WITH
DEWPOINTS IN THE MID TO UPPER 60S HOLDING BACK TO LOWER BRULE AREA.
NOT BUYING IN TO DEVELOPMENT OF COMPLEX OF STORMS TONIGHT ACROSS
SOUTHEAST SOUTH DAKOTA...WHICH WOULD ALMOST REQUIRE THAT DEVELOPMENT
TO STORMS OCCURS BACK TO THE WEST WHERE TERRAIN/CONVERGENCE WOULD
HAVE A BETTER CHANCE TO OVERCOME THE MASSIVE WARM LAYER ALOFT /+15
TO +16 C AT 700 HPA/ BY EVENING. RETAINED A LOW POPS DURING THE
EVENING IN THE EVENT OF OUTSIDE CHANCE DEVELOPMENT CAN EVOLVE TOWARD
MORE ELEVATED AS SPREADS EAST. A MUCH BETTER CHANCE THAT A MORE
ORGANIZED COMPLEX WILL TAKE SHAPE JUST NORTH AND EAST OF THE CWA...
WITHIN WARM ADVECTION ZONE AHEAD OF LOW PRESSURE PUSHING INTO THE
EASTERN DAKOTAS...WITH PERHAPS A SCATTERED TO LOW LIKELY CHANCE BY
LATER EVENING AND EARLY OVERNIGHT IN EASTERN PARTS OF SW MN/NW IA.
FAIRLY SOUTH SOUTHERLY GRADIENT AND VERY WARM AIRMASS WAS CONVINCING
ENOUGH TO RAISE OVERNIGHT LOWS A FEW DEGREES.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 420 AM CDT THU JUL 24 2014
EXPECT CONVECTIVE ACTIVITY TO PRETTY MUCH BE EAST OF OUR CWA AFTER
12Z FRIDAY. SHOULD THUS BE A PARTLY TO MOSTLY SUNNY SKY...WITH JUST
SOME CUMULUS POSSIBLE. WILL HAVE QUITE A BIT OF INSTABILITY...BUT A
STRONG INVERSION ALOFT WILL KEEP US CAPPED. MODEL THERMAL FIELDS
HAVE A DECENT SPREAD...BUT OVERALL HAVE SHOWN A WARMING TREND ON
RECENT RUNS. A BIT CONCERNED THAT THE STRONG INVERSION ALOFT AND
DECENT LOW LEVEL MOISTURE OF 60S AND 70S DEWPOINTS...WILL PREVENT US
FROM FULLY MIXING...ESPECIALLY ACROSS OUR EASTERN AREAS. SO DID GO
AHEAD AND WARM HIGHS A FEW DEGREES ACROSS THE BOARD INTO THE MID 80S
AND LOW 90S...BUT DID NOT GO TOO EXTREME YET. WILL HAVE TO MONITOR
THOUGH...AS FULL MIXING WOULD RESULT IN HIGHS A FEW DEGREES WARMER
THAN CURRENTLY FORECAST. THIS SEEMS MOST PROBABLE WEST OF INTERSTATE
29...AND THINKING WE MAY NEED TO WARM THAT AREA UP ON FUTURE
FORECASTS IF TRENDS CONTINUE.
CONVECTIVE ACTIVITY MAY BECOME MORE ACTIVE FRIDAY NIGHT INTO
SATURDAY MORNING. A STRONG MID AND UPPER JET WILL PUSH ACROSS THE
NORTHERN PLAINS...ACCOMPANIED BY PRETTY GOOD PV ADVECTION AS WELL.
THIS LARGE SCALE FORCING WILL INTERACT WITH A LOW LEVEL BOUNDARY AND
EASTERLY UPSLOPE FLOW ACROSS CENTRAL SOUTH DAKOTA. THUS THINKING IS
WE MAY SEE AN AREA OF ELEVATED CONVECTION FORM...WITH STORM MOTIONS
TAKING THIS ACTIVITY EAST SOUTHEAST INTO OUR CWA. ACTUALLY PRETTY
GOOD AGREEMENT BETWEEN THE ECMWF...NAM AND SREF ON THIS SOLUTION.
GFS IS A DRY OUTLIER...AND SEEMS TO REPRESENT A LESS LIKELY
SOLUTION. THUS DID GO AHEAD AND INCREASE POPS...MOVING INTO SOUTH
CENTRAL SOUTH DAKOTA AFTER MIDNIGHT...PUSHING TOWARDS THE INTERSTATE
29 CORRIDOR THROUGH THE MORNING. AMOUNT OF INSTABILITY AVAILABLE TO
THIS ELEVATED PARCEL REMAINS UNCERTAIN...BUT COULD END UP AROUND OR
JUST ABOVE 1000 J/KG. GIVEN THE STRONG JET...SPEED SHEAR SHOULD BE
PRETTY GOOD. THUS SHOULD STORMS FORM...AT LEAST SOME SEVERE HAIL
THREAT WOULD SEEM TO EXIST...POSSIBLY A WIND THREAT TOO WITH THE DRY
SUB CLOUD LAYER POSSIBLY HELPING ORGANIZE STORMS ALONG AN OUTFLOW.
THESE ELEVATED NOCTURNAL THUNDERSTORMS ARE TOUGH TO
FORECAST...THUS CONFIDENCE ON EVOLUTION REMAINS LOW...BUT
SOMETHING TO KEEP AN EYE ON.
EXPECT ANY CONVECTION WOULD EXIT THE AREA BY AFTERNOON...GIVING WAY
TO PARTLY TO MOSTLY SUNNY SKIES. TEMPERATURE FORECAST PROBABLY A BIT
LOWER CONFIDENCE THAN NORMAL DUE TO DIFFERENCES IN HOW MODELS HANDLE
MORNING CONVECTION AND DEBRIS CLOUDS. FOR NOW STAYED NEAR CONSENSUS
OF LOW TO MID 80S...BUT WOULD EXPECT ADJUSTMENTS UP OR DOWN A FEW
DEGREES MAY VERY WELL BE NEEDED AS WE GET CLOSER. A STRONG UPPER
WAVE WILL DIVE SOUTHEAST OUT OF CANADA INTO THE GREAT LAKES
REGION...PUSHING A COLD FRONT THROUGH OUR AREA BY SUNDAY. THIS WILL
RESULT IN A COOLER END TO THE WEEKEND. LOOKING AT MID 70S TO AROUND
80 ON SUNDAY...WITH BLUSTERY NORTHWESTERLY WINDS GUSTING AROUND 30
MPH.
THIS COOLER AND DRIER AIR IS EXPECTED TO CONTINUE INTO THE MIDDLE OF
NEXT WEEK AS THE PATTERN BECOMES MORE STAGNANT...WITH A DEEP TROUGH
OVER THE EASTERN USA AND RIDGE OVER THE WEST. APPEARS WE WILL STAY
ON THE COOLER SIDE OF THINGS...WITH THE RIDGING UNABLE TO BUILD FAR
ENOUGH EAST. THUS TEMPERATURES SHOULD STAY SEVERAL DEGREES BELOW
NORMAL THROUGH MID WEEK...WITH HIGHS IN THE 70S AND 80S AND LOWS IN
THE 50S AND 60S. NOT MUCH FORCING...BUT MOISTURE INCREASES
ENOUGH...THAT COMBINED WITH THE COOL TEMPERATURES ALOFT...WE MAY BE
ABLE TO GENERATE ENOUGH INSTABILITY FOR A FEW DIURNALLY DRIVEN SHOWERS
AND STORMS BY WEDNESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1220 PM CDT THU JUL 24 2014
OVERALL...VFR WILL PREVAIL FOR MOST AREAS THROUGH THE TAF PERIOD
ENDING AT 18Z FRIDAY. BUT THUNDERSTORMS MOVING SOUTHEASTWARD
ACROSS AREAS EAST OF THE JAMES RIVER VALLEY WILL CERTAINLY NEED
WATCHED INTO LATE THIS AFTEROON AND EVENING...AS A STOUT LOW LEVEL
JET REMAINS JUXTAPOSED RIGHT IN THIS AREA. THIS WILL GIVE THE
POSSIBILITY OF CONTINUED SCATTERED REDEVELOPMENT. FOR NOW...THIS
IS VERY DIFFICULT TO TIME SO LEFT OUT OF THE THREE TAF SITES THE
MENTION OF TSRA. KFSD MAY BE THE MOST IMPACTED BY THIS SCENARIO SO
DO NOT BE SURPRISED IF YOU SEE AMENDMENTS INVOLVING CONVECTION.
BUT ALSO NEED TO KEEP A CLOSE EYE ON KSUX FOR REDEVELOPMENT BUT
MUCH OF THEIR ACTIVITY MAY STAY TO THE NORTH AND EAST. KHON MAY
ALSO SEE MOST OF THEIR ACTIVITY OFF TO THE EAST. SO MOST CONCERNED
ABOUT KFSD THROUGH THE EVENING. IN ANY STRONG STORMS...BRIEF HAIL
AND MVFR CONDITIONS ARE POSSIBLE. LATE TONIGHT AND FRIDAY
MORNING...IT IS EXPECTED THAT THE CONVECTION WILL STAY NORTH OF
OUR AREA. CONCERNING WINDS...EXPECT FREQUENT GUSTS FROM THE SOUTH
AND SOUTHEAST ALONG AND EAST OF THE JAMES RIVER VALLEY THIS
AFTERNOON OF AROUND 25 TO 30 KNOTS. FURTHERMORE...A STRONG LOW
LEVEL JET WILL EXIST FOR MUCH OF THE AREA TONIGHT...SOME OF WHICH WILL
TRANSLATE DOWN TO THE SURFACE. BUT FOR NOW LEFT THE MENTION OF NON
CONVECTIVE LOW LEVEL WIND SHEAR OUT OF THE TAFS BECAUSE SURFACE
SPEEDS MAY BE STRONG ENOUGH TO PRECLUDE THE MENTION OF IT.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...MJ
SHORT TERM...CHAPMAN
LONG TERM...CHENARD
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1121 AM CDT THU JUL 24 2014
.UPDATE...
ISSUED AT 1121 AM CDT THU JUL 24 2014
HAVE TWEAKED POPS THIS MORNING AND RAISED THEM IN EAST CENTRAL SD...
SOUTHEASTWARD INTO PARTS OF SOUTHWEST MN AND NORTHWEST IA
ACCOUNTING FOR THE CURRENT CLUSTER OF ELEVATED STORMS MOVING
THROUGH. A FEW CELLS GET A BIT ANGRY ALOFT...BUT THEN CORES
COLLAPSE SO THUS ONLY ONE WARNING SO FAR. THE CELLS ARE ROOTED
NEAR 750MB SO THE WIND SHEAR IN MOST OF THE LOWEST 2KM IS NOT
BEING TAPPED. BUT THEY ARE HOLDING TOGETHER ALONG POSITIVE THETAE
ADVECTION AND WILL CERTAINLY IMPACT SOUTHWEST MN AND FAR NORTHWEST
IA THROUGH EARLY AFTERNOON. MORE UNCERTAIN IS WHAT THE CLUSTER IN
EASTERN ND AND EXTREME NORTHEAST SD WILL DO. HAD TO KEEP SOME
DECENT POPS GOING IN SOUTHWEST MN FOR THE MID AFTERNOON HOURS AND
MAY HAVE TO RAISE THEM IF THAT ACTIVITY HOLDS TOGETHER. HIGHS
STILL LOOK VERY WARM IN OUR FAR WEST...COOLING TO AROUND THE UPPER
70S TO NEAR 80 IN OUR EAST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 420 AM CDT THU JUL 24 2014
FAIRLY SHARP RIDGE WITH AXIS JUST EAST OF THE ROCKIES EARLY THIS
MORNING. ON WATER VAPOR LOOP...CAN SEE SEVERAL WAVES ROTATING
THROUGH THE RIDGE...ALL RIDING ON THE EDGE OF A FAIRLY STRONG MID
LEVEL FRONTAL BOUNDARY. STRONGEST WAVE BACK OVER PAC NW...BUT ONE
NICE WAVE PUSHING FROM ERN MT INTO WRN ND. PATCHY CLOUDS IN THE
9-10 KFT RANGE HAVE DEVELOPED FROM SOUTH CENTRAL ND TOWARD
SOUTHEASTERN SD...AND INCREASING LOW LEVEL JET WINDS ON MRR
PROFILER. ALL RECENT RUNS OF HRRR AND WRF-ARW HAVE BEEN FAIRLY
INSISTENT ON DEVELOPMENT OF CONVECTION OVER THE NEXT COUPLE HOURS
FROM 09Z-11Z OUT FROM THE JAMES VALLEY WESTWARD...AND MOST SOLUTION
HAVE AT LEAST SOME DEVELOPMENT OCCURRING THIS MORNING. GIVEN A DECENT
MID LEVEL THETA E ADVECTION FOCUS...AND MID LEVEL FRONTOGENETIC
AXIS...SEEMS WOULD BE FAVORED FOR A FEW STORMS DEVELOPING THIS
MORNING. HOWEVER...WILL BE INCREASINGLY DIFFICULT FOR ACTIVITY TO
BUILD EASTWARD AS FORCING WITH WEAK MID LEVEL WAVES DROPS SOUTHEAST
MOST LIKELY LOCATION FOR CONVECTION LOOKS TO BE THE MID TO SOUTHERN
JAMES VALLEY THEN SOUTHEAST TOWARD KSUX AREA DURING THE MORNING
HOURS. BY AFTERNOON...CONTINUED BUILDING HEIGHTS AND WARMING TEMPS
ALOFT AS WAVE MOVES PAST WILL START TO WEAR ON CONVECTIVE THREAT
WITH COVERAGE EXPECTED TO DWINDLE AS BUILDS EAST.
WITH ELEVATED INSTABILITY PERHAPS AS HIGH AS 1000 J/KG AND 2-6KM
SHEAR OF 30-40 KNOTS...POTENTIAL IS THERE FOR SOME ORGANIZED STORM
DEVELOPMENT AND UPDRAFT HELICITY ON HRRR INDICATES SOME NEED FOR
CONCERN FOR MARGINALLY SEVERE HAIL WITH ANY STRONGER STORMS THROUGH
AT LEAST MID TO LATE MORNING.
A PRETTY SHARP GRADIENT WILL AGAIN TODAY BE PRESENT BETWEEN WARM AND
HUMID LESS MIXED CONDITIONS...WITH A HOT...DRY...AND MORE MIXED
AIRMASS... LIKELY TO REMAIN JUST WEST OF THE CWA. HAVE RAISED TEMPS
MANY AREAS BY A COUPLE DEGREES...WITH MAINLY 80S...BUT SOME UPPER
70S IN MORE PERSISTENT CLOUDS/POTENTIAL PRECIP AXIS. HAVE LOWER 90S
CRAWLING BACK INTO THE WEST...AND WITH RECENT DRY CONDITIONS AND
WINDS GUSTING 25 TO 35 MPH...WILL START TO BRING A BIT MORE CONCERN
TO FIRE BEHAVIOR...BUT STARTS WILL STILL BE VERY DIFFICULT WITH
DEWPOINTS IN THE MID TO UPPER 60S HOLDING BACK TO LOWER BRULE AREA.
NOT BUYING IN TO DEVELOPMENT OF COMPLEX OF STORMS TONIGHT ACROSS
SOUTHEAST SOUTH DAKOTA...WHICH WOULD ALMOST REQUIRE THAT DEVELOPMENT
TO STORMS OCCURS BACK TO THE WEST WHERE TERRAIN/CONVERGENCE WOULD
HAVE A BETTER CHANCE TO OVERCOME THE MASSIVE WARM LAYER ALOFT /+15
TO +16 C AT 700 HPA/ BY EVENING. RETAINED A LOW POPS DURING THE
EVENING IN THE EVENT OF OUTSIDE CHANCE DEVELOPMENT CAN EVOLVE TOWARD
MORE ELEVATED AS SPREADS EAST. A MUCH BETTER CHANCE THAT A MORE
ORGANIZED COMPLEX WILL TAKE SHAPE JUST NORTH AND EAST OF THE CWA...
WITHIN WARM ADVECTION ZONE AHEAD OF LOW PRESSURE PUSHING INTO THE
EASTERN DAKOTAS...WITH PERHAPS A SCATTERED TO LOW LIKELY CHANCE BY
LATER EVENING AND EARLY OVERNIGHT IN EASTERN PARTS OF SW MN/NW IA.
FAIRLY SOUTH SOUTHERLY GRADIENT AND VERY WARM AIRMASS WAS CONVINCING
ENOUGH TO RAISE OVERNIGHT LOWS A FEW DEGREES.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 420 AM CDT THU JUL 24 2014
EXPECT CONVECTIVE ACTIVITY TO PRETTY MUCH BE EAST OF OUR CWA AFTER
12Z FRIDAY. SHOULD THUS BE A PARTLY TO MOSTLY SUNNY SKY...WITH JUST
SOME CUMULUS POSSIBLE. WILL HAVE QUITE A BIT OF INSTABILITY...BUT A
STRONG INVERSION ALOFT WILL KEEP US CAPPED. MODEL THERMAL FIELDS
HAVE A DECENT SPREAD...BUT OVERALL HAVE SHOWN A WARMING TREND ON
RECENT RUNS. A BIT CONCERNED THAT THE STRONG INVERSION ALOFT AND
DECENT LOW LEVEL MOISTURE OF 60S AND 70S DEWPOINTS...WILL PREVENT US
FROM FULLY MIXING...ESPECIALLY ACROSS OUR EASTERN AREAS. SO DID GO
AHEAD AND WARM HIGHS A FEW DEGREES ACROSS THE BOARD INTO THE MID 80S
AND LOW 90S...BUT DID NOT GO TOO EXTREME YET. WILL HAVE TO MONITOR
THOUGH...AS FULL MIXING WOULD RESULT IN HIGHS A FEW DEGREES WARMER
THAN CURRENTLY FORECAST. THIS SEEMS MOST PROBABLE WEST OF INTERSTATE
29...AND THINKING WE MAY NEED TO WARM THAT AREA UP ON FUTURE
FORECASTS IF TRENDS CONTINUE.
CONVECTIVE ACTIVITY MAY BECOME MORE ACTIVE FRIDAY NIGHT INTO
SATURDAY MORNING. A STRONG MID AND UPPER JET WILL PUSH ACROSS THE
NORTHERN PLAINS...ACCOMPANIED BY PRETTY GOOD PV ADVECTION AS WELL.
THIS LARGE SCALE FORCING WILL INTERACT WITH A LOW LEVEL BOUNDARY AND
EASTERLY UPSLOPE FLOW ACROSS CENTRAL SOUTH DAKOTA. THUS THINKING IS
WE MAY SEE AN AREA OF ELEVATED CONVECTION FORM...WITH STORM MOTIONS
TAKING THIS ACTIVITY EAST SOUTHEAST INTO OUR CWA. ACTUALLY PRETTY
GOOD AGREEMENT BETWEEN THE ECMWF...NAM AND SREF ON THIS SOLUTION.
GFS IS A DRY OUTLIER...AND SEEMS TO REPRESENT A LESS LIKELY
SOLUTION. THUS DID GO AHEAD AND INCREASE POPS...MOVING INTO SOUTH
CENTRAL SOUTH DAKOTA AFTER MIDNIGHT...PUSHING TOWARDS THE INTERSTATE
29 CORRIDOR THROUGH THE MORNING. AMOUNT OF INSTABILITY AVAILABLE TO
THIS ELEVATED PARCEL REMAINS UNCERTAIN...BUT COULD END UP AROUND OR
JUST ABOVE 1000 J/KG. GIVEN THE STRONG JET...SPEED SHEAR SHOULD BE
PRETTY GOOD. THUS SHOULD STORMS FORM...AT LEAST SOME SEVERE HAIL
THREAT WOULD SEEM TO EXIST...POSSIBLY A WIND THREAT TOO WITH THE DRY
SUB CLOUD LAYER POSSIBLY HELPING ORGANIZE STORMS ALONG AN OUTFLOW.
THESE ELEVATED NOCTURNAL THUNDERSTORMS ARE TOUGH TO
FORECAST...THUS CONFIDENCE ON EVOLUTION REMAINS LOW...BUT
SOMETHING TO KEEP AN EYE ON.
EXPECT ANY CONVECTION WOULD EXIT THE AREA BY AFTERNOON...GIVING WAY
TO PARTLY TO MOSTLY SUNNY SKIES. TEMPERATURE FORECAST PROBABLY A BIT
LOWER CONFIDENCE THAN NORMAL DUE TO DIFFERENCES IN HOW MODELS HANDLE
MORNING CONVECTION AND DEBRIS CLOUDS. FOR NOW STAYED NEAR CONSENSUS
OF LOW TO MID 80S...BUT WOULD EXPECT ADJUSTMENTS UP OR DOWN A FEW
DEGREES MAY VERY WELL BE NEEDED AS WE GET CLOSER. A STRONG UPPER
WAVE WILL DIVE SOUTHEAST OUT OF CANADA INTO THE GREAT LAKES
REGION...PUSHING A COLD FRONT THROUGH OUR AREA BY SUNDAY. THIS WILL
RESULT IN A COOLER END TO THE WEEKEND. LOOKING AT MID 70S TO AROUND
80 ON SUNDAY...WITH BLUSTERY NORTHWESTERLY WINDS GUSTING AROUND 30
MPH.
THIS COOLER AND DRIER AIR IS EXPECTED TO CONTINUE INTO THE MIDDLE OF
NEXT WEEK AS THE PATTERN BECOMES MORE STAGNANT...WITH A DEEP TROUGH
OVER THE EASTERN USA AND RIDGE OVER THE WEST. APPEARS WE WILL STAY
ON THE COOLER SIDE OF THINGS...WITH THE RIDGING UNABLE TO BUILD FAR
ENOUGH EAST. THUS TEMPERATURES SHOULD STAY SEVERAL DEGREES BELOW
NORMAL THROUGH MID WEEK...WITH HIGHS IN THE 70S AND 80S AND LOWS IN
THE 50S AND 60S. NOT MUCH FORCING...BUT MOISTURE INCREASES
ENOUGH...THAT COMBINED WITH THE COOL TEMPERATURES ALOFT...WE MAY BE
ABLE TO GENERATE ENOUGH INSTABILITY FOR A FEW DIURNALLY DRIVEN SHOWERS
AND STORMS BY WEDNESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 646 AM CDT THU JUL 24 2014
AN AREA OF SCATTERED THUNDERSTORMS WILL PUSH OUT OF THE KHON AREA
BY 13Z-14Z...AND MOVE TO IMPACT THE KFSD AND KSUX TAF SITE LATER
ON IN THE MORNING BETWEEN 13Z-17Z. A HEAVIER CORE IN STORMS WILL
LIKELY TAKE VISIBILITY TO MVFR...OTHERWISE VFR CONDITIONS ARE
EXPECTED WITH THE HIGH BASED STORMS. A FEW STORMS MAY ALSO PRODUCE
SOME SMALL HAIL. SURFACE SOUTHEAST TO SOUTH WINDS WILL INCREASE
AND WILL RESULT IN SOME STRONGER WIND GUSTS ABOVE 25 KNOTS DURING
THE MIDDAY AND AFTERNOON HOURS. IF WINDS DECOUPLE MORE THAN
EXPECTED TONIGHT...THERE COULD BE SOME LOW LEVEL WIND SHEAR FOR
KFSD OR KSUX. ANOTHER ELEMENT TO WATCH IS THE HIGH MOISTURE
CONTENT OF THE AIR...WHICH MAY ALSO LEAD TO A POTENTIAL FOR A
BRIEF PERIOD OF MVFR VISIBILITIES AROUND KSUX OF KFSD LATE.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...MJ
SHORT TERM...CHAPMAN
LONG TERM...CHENARD
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
647 AM CDT THU JUL 24 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 420 AM CDT THU JUL 24 2014
FAIRLY SHARP RIDGE WITH AXIS JUST EAST OF THE ROCKIES EARLY THIS
MORNING. ON WATER VAPOR LOOP...CAN SEE SEVERAL WAVES ROTATING
THROUGH THE RIDGE...ALL RIDING ON THE EDGE OF A FAIRLY STRONG MID
LEVEL FRONTAL BOUNDARY. STRONGEST WAVE BACK OVER PAC NW...BUT ONE
NICE WAVE PUSHING FROM ERN MT INTO WRN ND. PATCHY CLOUDS IN THE
9-10 KFT RANGE HAVE DEVELOPED FROM SOUTH CENTRAL ND TOWARD
SOUTHEASTERN SD...AND INCREASING LOW LEVEL JET WINDS ON MRR
PROFILER. ALL RECENT RUNS OF HRRR AND WRF-ARW HAVE BEEN FAIRLY
INSISTENT ON DEVELOPMENT OF CONVECTION OVER THE NEXT COUPLE HOURS
FROM 09Z-11Z OUT FROM THE JAMES VALLEY WESTWARD...AND MOST SOLUTION
HAVE AT LEAST SOME DEVELOPMENT OCCURRING THIS MORNING. GIVEN A DECENT
MID LEVEL THETA E ADVECTION FOCUS...AND MID LEVEL FRONTOGENETIC
AXIS...SEEMS WOULD BE FAVORED FOR A FEW STORMS DEVELOPING THIS
MORNING. HOWEVER...WILL BE INCREASINGLY DIFFICULT FOR ACTIVITY TO
BUILD EASTWARD AS FORCING WITH WEAK MID LEVEL WAVES DROPS SOUTHEAST
MOST LIKELY LOCATION FOR CONVECTION LOOKS TO BE THE MID TO SOUTHERN
JAMES VALLEY THEN SOUTHEAST TOWARD KSUX AREA DURING THE MORNING
HOURS. BY AFTERNOON...CONTINUED BUILDING HEIGHTS AND WARMING TEMPS
ALOFT AS WAVE MOVES PAST WILL START TO WEAR ON CONVECTIVE THREAT
WITH COVERAGE EXPECTED TO DWINDLE AS BUILDS EAST.
WITH ELEVATED INSTABILITY PERHAPS AS HIGH AS 1000 J/KG AND 2-6KM
SHEAR OF 30-40 KNOTS...POTENTIAL IS THERE FOR SOME ORGANIZED STORM
DEVELOPMENT AND UPDRAFT HELICITY ON HRRR INDICATES SOME NEED FOR
CONCERN FOR MARGINALLY SEVERE HAIL WITH ANY STRONGER STORMS THROUGH
AT LEAST MID TO LATE MORNING.
A PRETTY SHARP GRADIENT WILL AGAIN TODAY BE PRESENT BETWEEN WARM AND
HUMID LESS MIXED CONDITIONS...WITH A HOT...DRY...AND MORE MIXED
AIRMASS... LIKELY TO REMAIN JUST WEST OF THE CWA. HAVE RAISED TEMPS
MANY AREAS BY A COUPLE DEGREES...WITH MAINLY 80S...BUT SOME UPPER
70S IN MORE PERSISTENT CLOUDS/POTENTIAL PRECIP AXIS. HAVE LOWER 90S
CRAWLING BACK INTO THE WEST...AND WITH RECENT DRY CONDITIONS AND
WINDS GUSTING 25 TO 35 MPH...WILL START TO BRING A BIT MORE CONCERN
TO FIRE BEHAVIOR...BUT STARTS WILL STILL BE VERY DIFFICULT WITH
DEWPOINTS IN THE MID TO UPPER 60S HOLDING BACK TO LOWER BRULE AREA.
NOT BUYING IN TO DEVELOPMENT OF COMPLEX OF STORMS TONIGHT ACROSS
SOUTHEAST SOUTH DAKOTA...WHICH WOULD ALMOST REQUIRE THAT DEVELOPMENT
TO STORMS OCCURS BACK TO THE WEST WHERE TERRAIN/CONVERGENCE WOULD
HAVE A BETTER CHANCE TO OVERCOME THE MASSIVE WARM LAYER ALOFT /+15
TO +16 C AT 700 HPA/ BY EVENING. RETAINED A LOW POPS DURING THE
EVENING IN THE EVENT OF OUTSIDE CHANCE DEVELOPMENT CAN EVOLVE TOWARD
MORE ELEVATED AS SPREADS EAST. A MUCH BETTER CHANCE THAT A MORE
ORGANIZED COMPLEX WILL TAKE SHAPE JUST NORTH AND EAST OF THE CWA...
WITHIN WARM ADVECTION ZONE AHEAD OF LOW PRESSURE PUSHING INTO THE
EASTERN DAKOTAS...WITH PERHAPS A SCATTERED TO LOW LIKELY CHANCE BY
LATER EVENING AND EARLY OVERNIGHT IN EASTERN PARTS OF SW MN/NW IA.
FAIRLY SOUTH SOUTHERLY GRADIENT AND VERY WARM AIRMASS WAS CONVINCING
ENOUGH TO RAISE OVERNIGHT LOWS A FEW DEGREES.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 420 AM CDT THU JUL 24 2014
EXPECT CONVECTIVE ACTIVITY TO PRETTY MUCH BE EAST OF OUR CWA AFTER
12Z FRIDAY. SHOULD THUS BE A PARTLY TO MOSTLY SUNNY SKY...WITH JUST
SOME CUMULUS POSSIBLE. WILL HAVE QUITE A BIT OF INSTABILITY...BUT A
STRONG INVERSION ALOFT WILL KEEP US CAPPED. MODEL THERMAL FIELDS
HAVE A DECENT SPREAD...BUT OVERALL HAVE SHOWN A WARMING TREND ON
RECENT RUNS. A BIT CONCERNED THAT THE STRONG INVERSION ALOFT AND
DECENT LOW LEVEL MOISTURE OF 60S AND 70S DEWPOINTS...WILL PREVENT US
FROM FULLY MIXING...ESPECIALLY ACROSS OUR EASTERN AREAS. SO DID GO
AHEAD AND WARM HIGHS A FEW DEGREES ACROSS THE BOARD INTO THE MID 80S
AND LOW 90S...BUT DID NOT GO TOO EXTREME YET. WILL HAVE TO MONITOR
THOUGH...AS FULL MIXING WOULD RESULT IN HIGHS A FEW DEGREES WARMER
THAN CURRENTLY FORECAST. THIS SEEMS MOST PROBABLE WEST OF INTERSTATE
29...AND THINKING WE MAY NEED TO WARM THAT AREA UP ON FUTURE
FORECASTS IF TRENDS CONTINUE.
CONVECTIVE ACTIVITY MAY BECOME MORE ACTIVE FRIDAY NIGHT INTO
SATURDAY MORNING. A STRONG MID AND UPPER JET WILL PUSH ACROSS THE
NORTHERN PLAINS...ACCOMPANIED BY PRETTY GOOD PV ADVECTION AS WELL.
THIS LARGE SCALE FORCING WILL INTERACT WITH A LOW LEVEL BOUNDARY AND
EASTERLY UPSLOPE FLOW ACROSS CENTRAL SOUTH DAKOTA. THUS THINKING IS
WE MAY SEE AN AREA OF ELEVATED CONVECTION FORM...WITH STORM MOTIONS
TAKING THIS ACTIVITY EAST SOUTHEAST INTO OUR CWA. ACTUALLY PRETTY
GOOD AGREEMENT BETWEEN THE ECMWF...NAM AND SREF ON THIS SOLUTION.
GFS IS A DRY OUTLIER...AND SEEMS TO REPRESENT A LESS LIKELY
SOLUTION. THUS DID GO AHEAD AND INCREASE POPS...MOVING INTO SOUTH
CENTRAL SOUTH DAKOTA AFTER MIDNIGHT...PUSHING TOWARDS THE INTERSTATE
29 CORRIDOR THROUGH THE MORNING. AMOUNT OF INSTABILITY AVAILABLE TO
THIS ELEVATED PARCEL REMAINS UNCERTAIN...BUT COULD END UP AROUND OR
JUST ABOVE 1000 J/KG. GIVEN THE STRONG JET...SPEED SHEAR SHOULD BE
PRETTY GOOD. THUS SHOULD STORMS FORM...AT LEAST SOME SEVERE HAIL
THREAT WOULD SEEM TO EXIST...POSSIBLY A WIND THREAT TOO WITH THE DRY
SUB CLOUD LAYER POSSIBLY HELPING ORGANIZE STORMS ALONG AN OUTFLOW.
THESE ELEVATED NOCTURNAL THUNDERSTORMS ARE TOUGH TO
FORECAST...THUS CONFIDENCE ON EVOLUTION REMAINS LOW...BUT
SOMETHING TO KEEP AN EYE ON.
EXPECT ANY CONVECTION WOULD EXIT THE AREA BY AFTERNOON...GIVING WAY
TO PARTLY TO MOSTLY SUNNY SKIES. TEMPERATURE FORECAST PROBABLY A BIT
LOWER CONFIDENCE THAN NORMAL DUE TO DIFFERENCES IN HOW MODELS HANDLE
MORNING CONVECTION AND DEBRIS CLOUDS. FOR NOW STAYED NEAR CONSENSUS
OF LOW TO MID 80S...BUT WOULD EXPECT ADJUSTMENTS UP OR DOWN A FEW
DEGREES MAY VERY WELL BE NEEDED AS WE GET CLOSER. A STRONG UPPER
WAVE WILL DIVE SOUTHEAST OUT OF CANADA INTO THE GREAT LAKES
REGION...PUSHING A COLD FRONT THROUGH OUR AREA BY SUNDAY. THIS WILL
RESULT IN A COOLER END TO THE WEEKEND. LOOKING AT MID 70S TO AROUND
80 ON SUNDAY...WITH BLUSTERY NORTHWESTERLY WINDS GUSTING AROUND 30
MPH.
THIS COOLER AND DRIER AIR IS EXPECTED TO CONTINUE INTO THE MIDDLE OF
NEXT WEEK AS THE PATTERN BECOMES MORE STAGNANT...WITH A DEEP TROUGH
OVER THE EASTERN USA AND RIDGE OVER THE WEST. APPEARS WE WILL STAY
ON THE COOLER SIDE OF THINGS...WITH THE RIDGING UNABLE TO BUILD FAR
ENOUGH EAST. THUS TEMPERATURES SHOULD STAY SEVERAL DEGREES BELOW
NORMAL THROUGH MID WEEK...WITH HIGHS IN THE 70S AND 80S AND LOWS IN
THE 50S AND 60S. NOT MUCH FORCING...BUT MOISTURE INCREASES
ENOUGH...THAT COMBINED WITH THE COOL TEMPERATURES ALOFT...WE MAY BE
ABLE TO GENERATE ENOUGH INSTABILITY FOR A FEW DIURNALLY DRIVEN SHOWERS
AND STORMS BY WEDNESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 646 AM CDT THU JUL 24 2014
AN AREA OF SCATTERED THUNDERSTORMS WILL PUSH OUT OF THE KHON AREA
BY 13Z-14Z...AND MOVE TO IMPACT THE KFSD AND KSUX TAF SITE LATER
ON IN THE MORNING BETWEEN 13Z-17Z. A HEAVIER CORE IN STORMS WILL
LIKELY TAKE VISIBILITY TO MVFR...OTHERWISE VFR CONDITIONS ARE
EXPECTED WITH THE HIGH BASED STORMS. A FEW STORMS MAY ALSO PRODUCE
SOME SMALL HAIL. SURFACE SOUTHEAST TO SOUTH WINDS WILL INCREASE
AND WILL RESULT IN SOME STRONGER WIND GUSTS ABOVE 25 KNOTS DURING
THE MIDDAY AND AFTERNOON HOURS. IF WINDS DECOUPLE MORE THAN
EXPECTED TONIGHT...THERE COULD BE SOME LOW LEVEL WIND SHEAR FOR
KFSD OR KSUX. ANOTHER ELEMENT TO WATCH IS THE HIGH MOISTURE
CONTENT OF THE AIR...WHICH MAY ALSO LEAD TO A POTENTIAL FOR A
BRIEF PERIOD OF MVFR VISIBILITIES AROUND KSUX OF KFSD LATE.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHAPMAN
LONG TERM...CHENARD
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
423 AM CDT THU JUL 24 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 420 AM CDT THU JUL 24 2014
FAIRLY SHARP RIDGE WITH AXIS JUST EAST OF THE ROCKIES EARLY THIS
MORNING. ON WATER VAPOR LOOP...CAN SEE SEVERAL WAVES ROTATING
THROUGH THE RIDGE...ALL RIDING ON THE EDGE OF A FAIRLY STRONG MID
LEVEL FRONTAL BOUNDARY. STRONGEST WAVE BACK OVER PAC NW...BUT ONE
NICE WAVE PUSHING FROM ERN MT INTO WRN ND. PATCHY CLOUDS IN THE
9-10 KFT RANGE HAVE DEVELOPED FROM SOUTH CENTRAL ND TOWARD
SOUTHEASTERN SD...AND INCREASING LOW LEVEL JET WINDS ON MRR
PROFILER. ALL RECENT RUNS OF HRRR AND WRF-ARW HAVE BEEN FAIRLY
INSISTENT ON DEVELOPMENT OF CONVECTION OVER THE NEXT COUPLE HOURS
FROM 09Z-11Z OUT FROM THE JAMES VALLEY WESTWARD...AND MOST SOLUTION
HAVE AT LEAST SOME DEVELOPMENT OCCURRING THIS MORNING. GIVEN A DECENT
MID LEVEL THETA E ADVECTION FOCUS...AND MID LEVEL FRONTOGENETIC
AXIS...SEEMS WOULD BE FAVORED FOR A FEW STORMS DEVELOPING THIS
MORNING. HOWEVER...WILL BE INCREASINGLY DIFFICULT FOR ACTIVITY TO
BUILD EASTWARD AS FORCING WITH WEAK MID LEVEL WAVES DROPS SOUTHEAST
MOST LIKELY LOCATION FOR CONVECTION LOOKS TO BE THE MID TO SOUTHERN
JAMES VALLEY THEN SOUTHEAST TOWARD KSUX AREA DURING THE MORNING
HOURS. BY AFTERNOON...CONTINUED BUILDING HEIGHTS AND WARMING TEMPS
ALOFT AS WAVE MOVES PAST WILL START TO WEAR ON CONVECTIVE THREAT
WITH COVERAGE EXPECTED TO DWINDLE AS BUILDS EAST.
WITH ELEVATED INSTABILITY PERHAPS AS HIGH AS 1000 J/KG AND 2-6KM
SHEAR OF 30-40 KNOTS...POTENTIAL IS THERE FOR SOME ORGANIZED STORM
DEVELOPMENT AND UPDRAFT HELICITY ON HRRR INDICATES SOME NEED FOR
CONCERN FOR MARGINALLY SEVERE HAIL WITH ANY STRONGER STORMS THROUGH
AT LEAST MID TO LATE MORNING.
A PRETTY SHARP GRADIENT WILL AGAIN TODAY BE PRESENT BETWEEN WARM AND
HUMID LESS MIXED CONDITIONS...WITH A HOT...DRY...AND MORE MIXED
AIRMASS... LIKELY TO REMAIN JUST WEST OF THE CWA. HAVE RAISED TEMPS
MANY AREAS BY A COUPLE DEGREES...WITH MAINLY 80S...BUT SOME UPPER
70S IN MORE PERSISTENT CLOUDS/POTENTIAL PRECIP AXIS. HAVE LOWER 90S
CRAWLING BACK INTO THE WEST...AND WITH RECENT DRY CONDITIONS AND
WINDS GUSTING 25 TO 35 MPH...WILL START TO BRING A BIT MORE CONCERN
TO FIRE BEHAVIOR...BUT STARTS WILL STILL BE VERY DIFFICULT WITH
DEWPOINTS IN THE MID TO UPPER 60S HOLDING BACK TO LOWER BRULE AREA.
NOT BUYING IN TO DEVELOPMENT OF COMPLEX OF STORMS TONIGHT ACROSS
SOUTHEAST SOUTH DAKOTA...WHICH WOULD ALMOST REQUIRE THAT DEVELOPMENT
TO STORMS OCCURS BACK TO THE WEST WHERE TERRAIN/CONVERGENCE WOULD
HAVE A BETTER CHANCE TO OVERCOME THE MASSIVE WARM LAYER ALOFT /+15
TO +16 C AT 700 HPA/ BY EVENING. RETAINED A LOW POPS DURING THE
EVENING IN THE EVENT OF OUTSIDE CHANCE DEVELOPMENT CAN EVOLVE TOWARD
MORE ELEVATED AS SPREADS EAST. A MUCH BETTER CHANCE THAT A MORE
ORGANIZED COMPLEX WILL TAKE SHAPE JUST NORTH AND EAST OF THE CWA...
WITHIN WARM ADVECTION ZONE AHEAD OF LOW PRESSURE PUSHING INTO THE
EASTERN DAKOTAS...WITH PERHAPS A SCATTERED TO LOW LIKELY CHANCE BY
LATER EVENING AND EARLY OVERNIGHT IN EASTERN PARTS OF SW MN/NW IA.
FAIRLY SOUTH SOUTHERLY GRADIENT AND VERY WARM AIRMASS WAS CONVINCING
ENOUGH TO RAISE OVERNIGHT LOWS A FEW DEGREES.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 420 AM CDT THU JUL 24 2014
EXPECT CONVECTIVE ACTIVITY TO PRETTY MUCH BE EAST OF OUR CWA AFTER
12Z FRIDAY. SHOULD THUS BE A PARTLY TO MOSTLY SUNNY SKY...WITH JUST
SOME CUMULUS POSSIBLE. WILL HAVE QUITE A BIT OF INSTABILITY...BUT A
STRONG INVERSION ALOFT WILL KEEP US CAPPED. MODEL THERMAL FIELDS
HAVE A DECENT SPREAD...BUT OVERALL HAVE SHOWN A WARMING TREND ON
RECENT RUNS. A BIT CONCERNED THAT THE STRONG INVERSION ALOFT AND
DECENT LOW LEVEL MOISTURE OF 60S AND 70S DEWPOINTS...WILL PREVENT US
FROM FULLY MIXING...ESPECIALLY ACROSS OUR EASTERN AREAS. SO DID GO
AHEAD AND WARM HIGHS A FEW DEGREES ACROSS THE BOARD INTO THE MID 80S
AND LOW 90S...BUT DID NOT GO TOO EXTREME YET. WILL HAVE TO MONITOR
THOUGH...AS FULL MIXING WOULD RESULT IN HIGHS A FEW DEGREES WARMER
THAN CURRENTLY FORECAST. THIS SEEMS MOST PROBABLE WEST OF INTERSTATE
29...AND THINKING WE MAY NEED TO WARM THAT AREA UP ON FUTURE
FORECASTS IF TRENDS CONTINUE.
CONVECTIVE ACTIVITY MAY BECOME MORE ACTIVE FRIDAY NIGHT INTO
SATURDAY MORNING. A STRONG MID AND UPPER JET WILL PUSH ACROSS THE
NORTHERN PLAINS...ACCOMPANIED BY PRETTY GOOD PV ADVECTION AS WELL.
THIS LARGE SCALE FORCING WILL INTERACT WITH A LOW LEVEL BOUNDARY AND
EASTERLY UPSLOPE FLOW ACROSS CENTRAL SOUTH DAKOTA. THUS THINKING IS
WE MAY SEE AN AREA OF ELEVATED CONVECTION FORM...WITH STORM MOTIONS
TAKING THIS ACTIVITY EAST SOUTHEAST INTO OUR CWA. ACTUALLY PRETTY
GOOD AGREEMENT BETWEEN THE ECMWF...NAM AND SREF ON THIS SOLUTION.
GFS IS A DRY OUTLIER...AND SEEMS TO REPRESENT A LESS LIKELY
SOLUTION. THUS DID GO AHEAD AND INCREASE POPS...MOVING INTO SOUTH
CENTRAL SOUTH DAKOTA AFTER MIDNIGHT...PUSHING TOWARDS THE INTERSTATE
29 CORRIDOR THROUGH THE MORNING. AMOUNT OF INSTABILITY AVAILABLE TO
THIS ELEVATED PARCEL REMAINS UNCERTAIN...BUT COULD END UP AROUND OR
JUST ABOVE 1000 J/KG. GIVEN THE STRONG JET...SPEED SHEAR SHOULD BE
PRETTY GOOD. THUS SHOULD STORMS FORM...AT LEAST SOME SEVERE HAIL
THREAT WOULD SEEM TO EXIST...POSSIBLY A WIND THREAT TOO WITH THE DRY
SUB CLOUD LAYER POSSIBLY HELPING ORGANIZE STORMS ALONG AN OUTFLOW.
THESE ELEVATED NOCTURNAL THUNDERSTORMS ARE TOUGH TO
FORECAST...THUS CONFIDENCE ON EVOLUTION REMAINS LOW...BUT
SOMETHING TO KEEP AN EYE ON.
EXPECT ANY CONVECTION WOULD EXIT THE AREA BY AFTERNOON...GIVING WAY
TO PARTLY TO MOSTLY SUNNY SKIES. TEMPERATURE FORECAST PROBABLY A BIT
LOWER CONFIDENCE THAN NORMAL DUE TO DIFFERENCES IN HOW MODELS HANDLE
MORNING CONVECTION AND DEBRIS CLOUDS. FOR NOW STAYED NEAR CONSENSUS
OF LOW TO MID 80S...BUT WOULD EXPECT ADJUSTMENTS UP OR DOWN A FEW
DEGREES MAY VERY WELL BE NEEDED AS WE GET CLOSER. A STRONG UPPER
WAVE WILL DIVE SOUTHEAST OUT OF CANADA INTO THE GREAT LAKES
REGION...PUSHING A COLD FRONT THROUGH OUR AREA BY SUNDAY. THIS WILL
RESULT IN A COOLER END TO THE WEEKEND. LOOKING AT MID 70S TO AROUND
80 ON SUNDAY...WITH BLUSTERY NORTHWESTERLY WINDS GUSTING AROUND 30
MPH.
THIS COOLER AND DRIER AIR IS EXPECTED TO CONTINUE INTO THE MIDDLE OF
NEXT WEEK AS THE PATTERN BECOMES MORE STAGNANT...WITH A DEEP TROUGH
OVER THE EASTERN USA AND RIDGE OVER THE WEST. APPEARS WE WILL STAY
ON THE COOLER SIDE OF THINGS...WITH THE RIDGING UNABLE TO BUILD FAR
ENOUGH EAST. THUS TEMPERATURES SHOULD STAY SEVERAL DEGREES BELOW
NORMAL THROUGH MID WEEK...WITH HIGHS IN THE 70S AND 80S AND LOWS IN
THE 50S AND 60S. NOT MUCH FORCING...BUT MOISTURE INCREASES
ENOUGH...THAT COMBINED WITH THE COOL TEMPERATURES ALOFT...WE MAY BE
ABLE TO GENERATE ENOUGH INSTABILITY FOR A FEW DIURNALLY DRIVEN SHOWERS
AND STORMS BY WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1055 PM CDT WED JUL 23 2014
VFR CONDITIONS ARE EXPECETD THROUGH THE TAF PERIOD. SCATTERED
THUNDERSTORMS ARE EXPECTED TO MOVE INTO SOUTH CENTRAL SD LATE TONIGHT
AND SLOWLY TRACK EASTWARD ACROSS THE AREA THROUGH THE DAY THURSDAY.
EXPECT ACTIVITY IN THE KHON AREA FROM 09Z TO 14Z AND INTO THE I29
CORRIDOR...INCLUDING FSD AND SUX AFTER 13Z. AGAIN...COVERAGE WILL BE
SCATTERED HOWEVER DID LEAVE TEMPO MENTION AT ALL 3 TAF SITES. THE
HIGH BASED STORMS WILL LIKELY KEEP CONDITIONS PREDOMINATELY IN
VFR...BUT STRONGER GUSTS AND VERY BRIEF MVFR CONDITIONS WILL BE
POSSIBLE IN THE STRONGER STORMS. BREEZY SOUTH SOUTHEAST WINDS PICK UP
AFTER 12Z AND PERIST THROUGH THE END OF THE TAF PERIOD.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHAPMAN
LONG TERM...CHENARD
AVIATION...
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
122 PM CDT THU JUL 24 2014
.UPDATE...
JUST SENT A QUICK UPDATE TO LOWER POPS IN THE EAST FOR THE
AFTERNOON AND RE-CONFIGURE THE POP GRADIENT OVER THE HILL COUNTRY
BASED ON CURRENT RADAR/SATELLITE TRENDS AND RECENT ANALYSES OF
CONVECTIVE INSTABILITY.
&&
.PREV DISCUSSION... /ISSUED 1244 PM CDT THU JUL 24 2014/
UPDATE...18Z AVIATION BELOW.
AVIATION...A MID LEVEL DISTURBANCE IS CONTRIBUTING TO CHANCES FOR
SHRA AND TSTMS TODAY ACROSS SOUTH-CENTRAL TEXAS. COVERAGE HAS
DIMINISHED OVER THE PAST 2 HOURS ALONG AND EAST OF THE I-35
CORRIDOR...WITH NOW JUST A LONE TSTM NORTH OF AUS MOVING SW INTO
THE HILL COUNTRY. LATEST HI RESOLUTION RUNS OF HRRR AND TTECH SEEM
TO HAVE SLIGHTLY BETTER HANDLE ON TRENDS...ALTHOUGH NOT PERFECT...
AND SHOW ISOLD CONVECTION DEVELOPING MID AFTERNOON THROUGH SUNSET
ALONG AND SOUTH OF I-10...WITH BEST CHANCES TO MENTION VCSH IN
TAF AT DRT. SHRA/TSTMS SHOULD END AFTER SUNSET. OUTSIDE OF
PRECIP...VFR CONDITIONS WILL PREVAIL ACROSS THE REGION THIS
AFTERNOON AND EVENING.
PREV DISCUSSION... /ISSUED 919 AM CDT THU JUL 24 2014/
UPDATE...
JUST SENT A MAJOR UPDATE TO THE FORECAST FOR THE REMAINDER OF THE
DAY THROUGH 02Z THIS EVENING. IN SHORT...THE MCS THAT DEVELOPED
OVER OKLAHOMA/ARKANSAS YESTERDAY HELD TOGETHER ENOUGH TO BRING
SHOWERS TO LOCATIONS ALONG AND NORTH OF INTERSTATE 10 THIS
MORNING. A SECOND AREA OF STRONGER STORMS HAS DEVELOPED IN THE
BRENHAM AREA. THIS LATTER AREA OF STORMS MATCHES WELL WITH THE
TTECH AND CSU WRF RUNS...AND TO A LESSER EXTENT WITH THE HRRR.
THUS...WE EXPECT THIS AREA TO GROW IN SIZE AND BEGIN MOVING NEARLY
DUE WEST ALONG WITH THE GENERAL MOTION OF THE REMNANT FROM A TUTT
LOW OVER LOUISIANA IN PREVIOUS DAYS. THE HIGHEST POPS AND BEST
CHANCES FOR RAIN ARE IN THE EXTREME EASTERN AREAS OF THE COASTAL
PLAINS...WITH CHANCES AND QPF DECREASING TO THE WEST. TEMPERATURES
WILL BE 3-5F COOLER THAN THE PREVIOUS FORECAST...DUE TO THE
EXTENSIVE CLOUDCOVER...WHICH WILL LAST THROUGH EARLY AFTERNOON
BEFORE SCATTERING OUT DUE TO MIXING AND INGESTING OF BOUNDARY
LAYER MOIST AIR IN TO DEVELOPING THUNDERSTORMS.
PREV DISCUSSION... /ISSUED 647 AM CDT THU JUL 24 2014/
AVIATION...
/12Z TAFS/
TODAY`S FIRST ROUND OF SHOWERS ARE AFFECTING THE AUSTIN AREA
TERMINALS WITH VFR CONDITIONS PREVAILING AT ALL SITES. A SECOND ROUND
OF SHOWERS AND THUNDERSTORMS ARE ANTICIPATED LATER IN THE
AFTERNOON AS AN UPPER LEVEL DISTURBANCE MOVES ACROSS SOUTH CENTRAL
TEXAS. OPTED TO LEAVE OUT MENTIONING SHRA/TSRA FROM THE 12Z TAFS
PACKAGE AS ANTICIPATED SHOWERS OR STORMS WILL BE ISOLATED AND
DIFFICULT TO PINPOINT AT THIS TIME. WINDS WILL BE LIGHT AND
VARIABLE THROUGH ABOUT NOON TODAY AND BECOMING SOUTHEASTERLY AT 5
TO 10 KNOTS IN THE AFTERNOON. OTHERWISE...VFR CONDITIONS TO
DOMINATE THE AREA SITES FOR THE FORECAST PERIOD.
PREV DISCUSSION... /ISSUED 352 AM CDT THU JUL 24 2014/
SHORT TERM (TODAY THROUGH FRIDAY)...
NORTHEASTERLY FLOW ALOFT IS WELL ENTRENCHED ACROSS SOUTH CENTRAL
TEXAS PER AREA 24/00Z RAOB DATA. THIS PATTERN USUALLY DOES NOT
BODE WELL FOR PRECIPITATION. HOWEVER...THE LATEST RADAR DATA DOES
SHOW SOME WEAK ECHOES DEVELOPING ACROSS PORTIONS OF CENTRAL TEXAS.
THIS ACTIVITY IS LIKELY ENHANCED BY A MID-LEVEL SHORTWAVE TROUGH
MOVING THROUGH THE CENTRAL PORTION OF THE STATE EARLY THIS
MORNING. IN ADDITION...A SURFACE TROUGH LOCATED ROUGHLY ALONG AN
AUSTIN TO ROCKSPRINGS LINE AS OF 06Z COULD AID IN THE DEVELOPMENT
OF CONVECTION TODAY. THE HI-RES RUC...3KM TEXAS TECH WRF AND SREF
ARE IN GOOD AGREEMENT IN SHOWING ADDITIONAL CONVECTION THIS
AFTERNOON ACROSS A GOOD PORTION OF SOUTH CENTRAL TEXAS. BASED ON
THE ABOVE...WE HAVE INCLUDED A 20% CHANCE FOR SHOWERS AND
THUNDERSTORMS ACROSS MOST AREAS TODAY. A DECREASE IN ACTIVITY IS
EXPECTED WITH THE LOSS OF DAYTIME HEATING AND WITH SUBSIDENCE
MOVING IN BEHIND THE MID-LEVEL SHORTWAVE TROUGH. ON FRIDAY... A
FEW SHOWERS AND STORMS REMAIN POSSIBLE ACROSS THE COASTAL
PLAINS... WITH THE REMAINDER OF THE REGION EXPECTED TO REMAIN DRY.
OTHERWISE...HOT AND HUMID CONDITIONS WILL PERSIST THROUGH FRIDAY
WITH HIGHS IN THE MID 90S TO NEAR 100 AND LOWS IN THE 70S.
LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...
THE FLOW ALOFT SLOWLY BEGINS TO CHANGE FROM NORTHEAST TO EAST THIS
WEEKEND AS THE DOMINANT SUBTROPICAL RIDGE AXIS EXPANDS ACROSS THE
REGION. WITH THIS PATTERN INTACT...WE EXPECT DRY WEATHER ALONG WITH
CONTINUED HOT AND HUMID CONDITIONS THROUGH THE WEEKEND. FOR THE
EARLY AND MIDDLE PORTION OF THE UPCOMING WORK WEEK...THE MEDIUM
RANGE MODELS CONTINUE TO REMAIN CONSISTENT WITH THE LARGE SCALE
FLOW PATTERN ACROSS THE CONUS. THE SUBTROPICAL RIDGE WILL
RETROGRADE INTO THE DESERT SOUTHWEST...WHILE A DEEP TROUGH
DEVELOPS OVER THE EASTERN HALF OF THE LOWER 48. THIS WILL BRING
NORTHWEST FLOW ALOFT TO SOUTH CENTRAL TEXAS BEGINNING TUESDAY AND
CONTINUING THROUGH NEXT WEEK. A COLD FRONT IS EXPECTED TO
GRADUALLY WORK SOUTHWARD INTO TEXAS NEXT WEEK...WITH THE TIMING OF
THIS FRONT LIKELY CONTROLLED BY THE AMOUNT OF CONVECTION THAT
DEVELOPS NEAR THE BOUNDARY. MOS GUIDANCE POPS ARE RATHER LOW...BUT
GIVEN THE PATTERN...WOULD NOT BE SURPRISED IF LATER DATA BEGAN TO
SHOW AN INCREASE IN PRECIPITATION CHANCES. FOR NOW...WE WILL KEEP
POPS LOW (20%) FOR TUESDAY AND WEDNESDAY...WITH LOCATIONS
GENERALLY NORTH OF I-10 REMAINING FAVORED FOR PRECIPITATION.
TEMPERATURES SHOULD ALSO BEGIN A SLOW DOWNWARD TREND NEXT
WEEK...BUT CURRENT DATA SUGGESTS THAT WILL NOT HAPPEN UNTIL
WEDNESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 76 100 76 99 77 / 20 - - - -
AUSTIN BERGSTROM INTL AIRPORT 73 99 73 98 74 / 20 - - - -
NEW BRAUNFELS MUNI AIRPORT 73 99 73 99 75 / 20 - - - -
BURNET MUNI AIRPORT 74 97 74 97 74 / 30 - - 0 0
DEL RIO INTL AIRPORT 77 100 77 101 79 / 20 - - 0 -
GEORGETOWN MUNI AIRPORT 75 98 75 98 76 / 20 - - 0 0
HONDO MUNI AIRPORT 73 98 74 99 75 / 20 - - 0 -
SAN MARCOS MUNI AIRPORT 73 98 74 98 75 / 20 - - - -
LA GRANGE - FAYETTE REGIONAL 75 98 76 97 77 / 20 20 10 10 -
SAN ANTONIO INTL AIRPORT 76 98 76 98 77 / 20 - - - -
STINSON MUNI AIRPORT 75 98 75 99 76 / 20 10 - - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...76
SYNOPTIC/GRIDS...26
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1244 PM CDT THU JUL 24 2014
.UPDATE...18Z AVIATION BELOW.
&&
.AVIATION...A MID LEVEL DISTURBANCE IS CONTRIBUTING TO CHANCES FOR
SHRA AND TSTMS TODAY ACROSS SOUTH-CENTRAL TEXAS. COVERAGE HAS
DIMINISHED OVER THE PAST 2 HOURS ALONG AND EAST OF THE I-35
CORRIDOR...WITH NOW JUST A LONE TSTM NORTH OF AUS MOVING SW INTO
THE HILL COUNTRY. LATEST HI RESOLUTION RUNS OF HRRR AND TTECH SEEM
TO HAVE SLIGHTLY BETTER HANDLE ON TRENDS...ALTHOUGH NOT PERFECT...
AND SHOW ISOLD CONVECTION DEVELOPING MID AFTERNOON THROUGH SUNSET
ALONG AND SOUTH OF I-10...WITH BEST CHANCES TO MENTION VCSH IN
TAF AT DRT. SHRA/TSTMS SHOULD END AFTER SUNSET. OUTSIDE OF
PRECIP...VFR CONDITIONS WILL PREVAIL ACROSS THE REGION THIS
AFTERNOON AND EVENING.
&&
.PREV DISCUSSION... /ISSUED 919 AM CDT THU JUL 24 2014/
UPDATE...
JUST SENT A MAJOR UPDATE TO THE FORECAST FOR THE REMAINDER OF THE
DAY THROUGH 02Z THIS EVENING. IN SHORT...THE MCS THAT DEVELOPED
OVER OKLAHOMA/ARKANSAS YESTERDAY HELD TOGETHER ENOUGH TO BRING
SHOWERS TO LOCATIONS ALONG AND NORTH OF INTERSTATE 10 THIS
MORNING. A SECOND AREA OF STRONGER STORMS HAS DEVELOPED IN THE
BRENHAM AREA. THIS LATTER AREA OF STORMS MATCHES WELL WITH THE
TTECH AND CSU WRF RUNS...AND TO A LESSER EXTENT WITH THE HRRR.
THUS...WE EXPECT THIS AREA TO GROW IN SIZE AND BEGIN MOVING NEARLY
DUE WEST ALONG WITH THE GENERAL MOTION OF THE REMNANT FROM A TUTT
LOW OVER LOUISIANA IN PREVIOUS DAYS. THE HIGHEST POPS AND BEST
CHANCES FOR RAIN ARE IN THE EXTREME EASTERN AREAS OF THE COASTAL
PLAINS...WITH CHANCES AND QPF DECREASING TO THE WEST. TEMPERATURES
WILL BE 3-5F COOLER THAN THE PREVIOUS FORECAST...DUE TO THE
EXTENSIVE CLOUDCOVER...WHICH WILL LAST THROUGH EARLY AFTERNOON
BEFORE SCATTERING OUT DUE TO MIXING AND INGESTING OF BOUNDARY
LAYER MOIST AIR IN TO DEVELOPING THUNDERSTORMS.
PREV DISCUSSION... /ISSUED 647 AM CDT THU JUL 24 2014/
AVIATION...
/12Z TAFS/
TODAY`S FIRST ROUND OF SHOWERS ARE AFFECTING THE AUSTIN AREA
TERMINALS WITH VFR CONDITIONS PREVAILING AT ALL SITES. A SECOND ROUND
OF SHOWERS AND THUNDERSTORMS ARE ANTICIPATED LATER IN THE
AFTERNOON AS AN UPPER LEVEL DISTURBANCE MOVES ACROSS SOUTH CENTRAL
TEXAS. OPTED TO LEAVE OUT MENTIONING SHRA/TSRA FROM THE 12Z TAFS
PACKAGE AS ANTICIPATED SHOWERS OR STORMS WILL BE ISOLATED AND
DIFFICULT TO PINPOINT AT THIS TIME. WINDS WILL BE LIGHT AND
VARIABLE THROUGH ABOUT NOON TODAY AND BECOMING SOUTHEASTERLY AT 5
TO 10 KNOTS IN THE AFTERNOON. OTHERWISE...VFR CONDITIONS TO
DOMINATE THE AREA SITES FOR THE FORECAST PERIOD.
PREV DISCUSSION... /ISSUED 352 AM CDT THU JUL 24 2014/
SHORT TERM (TODAY THROUGH FRIDAY)...
NORTHEASTERLY FLOW ALOFT IS WELL ENTRENCHED ACROSS SOUTH CENTRAL
TEXAS PER AREA 24/00Z RAOB DATA. THIS PATTERN USUALLY DOES NOT
BODE WELL FOR PRECIPITATION. HOWEVER...THE LATEST RADAR DATA DOES
SHOW SOME WEAK ECHOES DEVELOPING ACROSS PORTIONS OF CENTRAL TEXAS.
THIS ACTIVITY IS LIKELY ENHANCED BY A MID-LEVEL SHORTWAVE TROUGH
MOVING THROUGH THE CENTRAL PORTION OF THE STATE EARLY THIS
MORNING. IN ADDITION...A SURFACE TROUGH LOCATED ROUGHLY ALONG AN
AUSTIN TO ROCKSPRINGS LINE AS OF 06Z COULD AID IN THE DEVELOPMENT
OF CONVECTION TODAY. THE HI-RES RUC...3KM TEXAS TECH WRF AND SREF
ARE IN GOOD AGREEMENT IN SHOWING ADDITIONAL CONVECTION THIS
AFTERNOON ACROSS A GOOD PORTION OF SOUTH CENTRAL TEXAS. BASED ON
THE ABOVE...WE HAVE INCLUDED A 20% CHANCE FOR SHOWERS AND
THUNDERSTORMS ACROSS MOST AREAS TODAY. A DECREASE IN ACTIVITY IS
EXPECTED WITH THE LOSS OF DAYTIME HEATING AND WITH SUBSIDENCE
MOVING IN BEHIND THE MID-LEVEL SHORTWAVE TROUGH. ON FRIDAY... A
FEW SHOWERS AND STORMS REMAIN POSSIBLE ACROSS THE COASTAL
PLAINS... WITH THE REMAINDER OF THE REGION EXPECTED TO REMAIN DRY.
OTHERWISE...HOT AND HUMID CONDITIONS WILL PERSIST THROUGH FRIDAY
WITH HIGHS IN THE MID 90S TO NEAR 100 AND LOWS IN THE 70S.
LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...
THE FLOW ALOFT SLOWLY BEGINS TO CHANGE FROM NORTHEAST TO EAST THIS
WEEKEND AS THE DOMINANT SUBTROPICAL RIDGE AXIS EXPANDS ACROSS THE
REGION. WITH THIS PATTERN INTACT...WE EXPECT DRY WEATHER ALONG WITH
CONTINUED HOT AND HUMID CONDITIONS THROUGH THE WEEKEND. FOR THE
EARLY AND MIDDLE PORTION OF THE UPCOMING WORK WEEK...THE MEDIUM
RANGE MODELS CONTINUE TO REMAIN CONSISTENT WITH THE LARGE SCALE
FLOW PATTERN ACROSS THE CONUS. THE SUBTROPICAL RIDGE WILL
RETROGRADE INTO THE DESERT SOUTHWEST...WHILE A DEEP TROUGH
DEVELOPS OVER THE EASTERN HALF OF THE LOWER 48. THIS WILL BRING
NORTHWEST FLOW ALOFT TO SOUTH CENTRAL TEXAS BEGINNING TUESDAY AND
CONTINUING THROUGH NEXT WEEK. A COLD FRONT IS EXPECTED TO
GRADUALLY WORK SOUTHWARD INTO TEXAS NEXT WEEK...WITH THE TIMING OF
THIS FRONT LIKELY CONTROLLED BY THE AMOUNT OF CONVECTION THAT
DEVELOPS NEAR THE BOUNDARY. MOS GUIDANCE POPS ARE RATHER LOW...BUT
GIVEN THE PATTERN...WOULD NOT BE SURPRISED IF LATER DATA BEGAN TO
SHOW AN INCREASE IN PRECIPITATION CHANCES. FOR NOW...WE WILL KEEP
POPS LOW (20%) FOR TUESDAY AND WEDNESDAY...WITH LOCATIONS
GENERALLY NORTH OF I-10 REMAINING FAVORED FOR PRECIPITATION.
TEMPERATURES SHOULD ALSO BEGIN A SLOW DOWNWARD TREND NEXT
WEEK...BUT CURRENT DATA SUGGESTS THAT WILL NOT HAPPEN UNTIL
WEDNESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 97 76 100 76 99 / 30 30 - - -
AUSTIN BERGSTROM INTL AIRPORT 96 73 99 73 98 / 30 30 - - -
NEW BRAUNFELS MUNI AIRPORT 96 73 99 73 99 / 40 40 - - -
BURNET MUNI AIRPORT 95 74 97 74 97 / 40 30 - - 0
DEL RIO INTL AIRPORT 98 77 100 77 101 / 20 20 - - 0
GEORGETOWN MUNI AIRPORT 95 75 98 75 98 / 30 30 - - 0
HONDO MUNI AIRPORT 95 73 98 74 99 / 30 30 - - 0
SAN MARCOS MUNI AIRPORT 95 73 98 74 98 / 40 40 - - -
LA GRANGE - FAYETTE REGIONAL 95 75 98 76 97 / 70 50 20 10 10
SAN ANTONIO INTL AIRPORT 95 76 98 76 98 / 30 30 - - -
STINSON MUNI AIRPORT 96 75 98 75 99 / 30 30 10 - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...76
SYNOPTIC/GRIDS...26
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
748 AM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONT WILL ENTER THE REGION TODAY AND SHIFT SOUTHEAST OF
THE AREA BY LATE TONIGHT. HIGH PRESSURE OVER THE MIDWEST WILL
BUILD ACROSS THE MID ATLANTIC THROUGH FRIDAY. OVER THE WEEKEND THE
PATTERN SETS UP FOR POTENTIAL UPPER DISTURBANCES MOVING INTO THE
REGION ON A NORTHWEST FLOW. A STRONG FRONT IS EXPECTED TO CROSS
THE AREA MONDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 730 AM EDT THURSDAY...
FORECAST UPDATED TO ACCOUNT MORE COVERAGE IN THE PIEDMONT WITH
LESS IN THE WEST. STILL LOOKS LIKE FRONT AND MORE CONVECTION WILL
FIRE UP AND MOVE INTO THE WEST LATER THIS MORNING. CLOUD COVER
SHOULD HAMPER SEVERITY OF THE STORMS OVER THE MTNS BUT THE
POTENTIAL EXISTS FURTHER EAST FOR BREAKS IN THE OVC TO OCCUR TO
ALLOW FOR MORE TSRA DEVELOPMENT.
PREVIOUS DISCUSSION AT 330 AM...
A COUPLE OF SHORTWAVE TO DEAL WITH THROUGH THIS AFTERNOON. FIRST IS
OVER THE CENTRAL APPALACHIANS WITH MAIN BATCH OF SHRA AND ISOLATED
TSRA OCCURRING ALONG AND AHEAD OF IT. DESPITE INCREASING CIN AND
LIMITED INSTABILITY...HIGH THETA-E AND UPPER SUPPORT KEEPING SOME
STORMS ACROSS NW NC PIEDMONT INTO SOUTHSIDE VA. 4Z HRRR HANDLED THIS
PRETTY WELL...AND FOLLOWED SOME OF THIS INTO THE MORNING.
FRONTAL BOUNDARY LIES FROM NORTH OF CRW WEST TO SOUTH OF CVG AND
SOUTH TOWARD BNA THIS MORNING. SFC LOW ALONG THE FRONT OVER THE TN
VALLEY IS EXPECTED TO PUSH NORTHEAST INTO THE PIEDMONT OF VA BY MID
AFTERNOON AND SENDING THE FRONT WELL EAST OF THE MOUNTAINS BY THEN.
STILL UPPER SHORTWAVE THAT IS ACROSS IL THIS MORNING IS GOING TO
MOVE INTO THE MTNS THIS AFTERNOON AND WILL KEEP THREAT OF
SHOWERS/STORMS AROUND. BEST LIFT AND INSTABILITY THOUGH LOOKS TO
MOVE EAST OF THE MTNS THIS AFTERNOON. SPC HAS 5 PERCENT FOR DAMAGING
WINDS ACROSS MOST OF THE AREA TODAY. SOLAR INSOLATION MAY BE LIMITED
AS CLOUD COVER PER SAT TRENDS AND MODEL RH FORECASTS SUGGEST BKN-
OVC.
THE HIGHS TODAY WILL BE IMPACTED BY BOTH CLOUDS/CONVECTION BUT STILL
WARM WITH READINGS RANGING FROM THE MID 70S WEST TO MID 80S EAST.
TONIGHT...THE MAIN AXIS OF LIFT AND MOISTURE SHIFTS EAST OF AREA
WITH SKIES STARTING TO CLEAR IN THE WEST. WILL KEEP HIGH CHANCE
EARLY IN THE EAST THEN DRY IT OUT BY MIDNIGHT/EARLY OVERNIGHT...WHEN
MAIN TROUGH AXIS AT 5H SHIFTS ACROSS. LESS HUMID AIR WILL PUSH INTO
THE MOUNTAINS AT LEAST THOUGH PROXIMITY OF FRONT THAT STALLS OVER
ERN NC/SC MAY INHIBIT THE LOWER DEWPOINTS REACHING THE SE CWA
UNTIL FRIDAY. LOWS ARE GOING TO RANGE FROM THE MID 50S ACROSS THE
HIGHER MTNS TO MID 60S SOUTHEAST.
FRIDAY WILL BE DRY AND LESS HUMID WITH HIGH PRESSURE NOSING IN FROM
THE MID ATLANTIC TURNING WINDS AROUND MORE TO THE NE-E. HIGHS
RANGING FROM THE UPPER 70S MTNS TO LOWER 80S ROANOKE TO MID 80S EAST
CAN BE EXPECTED.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 350 AM EDT THURSDAY...
FOR SATURDAY...MOISTURE WILL BEGIN TO RETURN TO THE FORECAST AREA
FROM THE SOUTH AND SOUTHWEST. CAN`T RULE OUT A LATE AFTERNOON
POPUP SHOWER OVER THE MOUNTAINS...BUT THINK MOST AREAS WILL REMAIN
DRY UNTIL THE ARRIVAL OF A FRONT MONDAY. WILL HAVE TO MONITOR
THIS UPSTREAM FRONT CLOSELY AS IT MAY CAST SOME PREFRONTAL SHOWERS
AND STORMS OUR WAY AS EARLY AS SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 515 PM EDT WEDNESDAY...
STRONG COLD FRONT IS SLATED TO CROSS THE FORECAST AREA LATE SUNDAY
INTO MONDAY...ASSOCIATED WITH A VIGOROUS SHORT WAVE TROUGH THAT
WILL BE MOVING ACROSS THE GREAT LAKES AND OHIO VALLEY. THIS
PARTICULARLY STRONG DISTURBANCE...NOTED BY ALL THE
MODELS...PROMISES TO AMPLIFY THE EASTERN LONG WAVE TROUGH...A
PATTERN THAT WILL NET COOLER THAN NORMAL TEMPERATURES FOR SEVERAL
DAYS NEXT WEEK.
DURING THE TRANSITION SUNDAY INTO MONDAY...INCREASED INSTABILITY
AHEAD OF THE FRONT ALONG WITH STRONG DYNAMIC FORCING WILL RESULT
IN POTENTIAL FOR STRONG TO SEVERE STORMS. THE OPPORTUNITY WILL
EXIST FOR ORGANIZED DEEP CONVECTION WITH POTENTIAL FOR A MESOSCALE
CONVECTIVE SYSTEM (MCS) TO CROSS THE FORECAST AREA FROM THE WEST.
ATTM WILL MAINTAIN THE BEST CHANCE FOR SHOWERS/STORMS SUNDAY...WITH
THE THREAT LINGERING INTO MONDAY UNTIL THE SURFACE FRONT CAN
COMPLETELY CLEAR THE FORECAST AREA. GENERALLY FOLLOWED HPC
GUIDANCE THROUGH THE PERIOD TRENDING POPS DOWNWARD AFTER THE EARLY
WEEK FROPA.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 735 AM EDT THURSDAY...
MOISTURE IN THE LOW LVLS PLUS ADDED RAINFALL HAS ALLOWED FOR FOG
AT A FEW LOCATIONS THIS MORNING. HOWEVER EXPECT THIS TO BE SHORT
LIVED. SHOWERS ARE GOING TO BRING TEMP MVFR VSBYS TO DAN TO START
THE TERMINALS.
HIGH-RES MODELS FAVOR MORE CONVECTION MOVING OUT OF WV INTO VA
AREA BY MIDDAY...WITH BEST CHANCE IN THE ROA/LYH/DAN CORRIDOR.
THIS AFTERNOON. KEPT VCTS IN BUT HAVE ENOUGH CONFIDENCE IN THE
HIGH RES MODELS OVERALL TO ADD TEMPO THUNDER IN AT LYH/DAN LATER
THIS AFTERNOON. LOOK FOR CIGS TO BE MVFR IN THE MTNS EARLY BEFORE
BECOMING VFR BY MIDDAY/18Z.
CONVECTION WILL EXIT THE MOUNTAINS BY 21-22Z AND DAN/LYH BY 00Z.
TONIGHT WILL BE TRICKY AS DRY AIR MAY BE SLOW TO ARRIVE IN
EARNEST. DEPENDING ON HOW MUCH RAIN OCCURS AND WITH CLEARING THINK
FOG WILL BECOME AN ISSUE AT MOST SITES. THINK LWB/BCB WILL HAVE
DENSE FOG AT LEAST BEFORE THE DRY AIR ARRIVES.
EXTENDED AVIATION DISCUSSION...
AIRMASS WILL DRY OUT BEHIND THE FRONT GOING INTO FRIDAY-
SATURDAY. VFR FRI- SAT OUTSIDE OF ANY VALLEY FOG AT KLWB/KBCB
EACH MORNING. ANOTHER FRONT AND ASSOCIATED UPPER IMPULSES COULD
BRING A GOOD THREAT OF STORMS IN THE SUN-MON TIME FRAME. DURING
THIS TIME MAINLY VFR...EXCEPT IN TSRA AND FOR ANY LATE NIGHT FOG.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WP
NEAR TERM...WP
SHORT TERM...PM/WP
LONG TERM...PM
AVIATION...WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
149 AM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH THE AREA FROM THE NORTHWEST TONIGHT AND
CROSS THE MID ATLANTIC REGION THURSDAY. SCATTERED TO NUMEROUS SHOWERS
AND THUNDERSTORMS WILL ACCOMPANY THE FRONTAL PASSAGE. DRIER AIR
WILL MOVE INTO THE AREA BEHIND THE FRONT FRIDAY WITH A DAY OR TWO
OF DRY WEATHER...FRIDAY INTO SATURDAY. MOISTURE WILL QUICKLY RETURN
OVER THE WEEKEND WITH HEAT AND HUMIDITY HELPING TO TRIGGER MORE
THUNDERSTORM ACTIVITY. A STRONG FRONT IS EXPECTED TO CROSS THE
AREA LATE SUNDAY INTO MONDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 918 PM EDT WEDNESDAY...
STORMS IN EASTERN KY/WV ASSOCIATED WITH AN APPROACHING SHORTWAVE
IN THE LOWER OHIO VALLEY PICKING UP INTENSITY THIS EVENING AS THIS
ACTIVITY MOVES INTO UNSTABLE AIR...EVEN WITH THE LOSS OF HEATING.
00Z RNK SOUNDING SHOWED CAPES GREATER THAN 2800 J/KG.
23Z HRRR RUN CONTINUES THE TREND OF STRENGTHENING THIS ACTIVITY
AS IT MOVES INTO SOUTHEAST WV AND THE MOUNTAINS OF VA THIS
EVENING. AS A RESULT...INCREASED POPS IN THIS AREA UNTIL VERY LATE
IN THE NIGHT. WOULD ALSO NOT BE SURPRISED TO SEE STORMS RE- FIRE
ALONG DEVELOPING LEE-SIDE TROF IN THE VA SOUTHSIDE AND NC PIEDMONT
VERY LATE TONIGHT. ALSO INCREASED POPS IN THIS AREA.
NEXT QUESTION WILL BE PRECIPITATION TOMORROW IN ASSOCIATION WITH
APPROACHING COLD FRONT AS UPPER TROUGH AMPLIFIES OVER THE GREAT
LAKES. FRONTAL BOUNDARY WILL MAKE ITS WAY TOWARD THE WESTERN CWA
BY THU MORNING...AND MODELS DEVELOP FAIRLY WIDESPREAD COVERAGE OF
PRECIP ACROSS THE WEST EARLY TOMORROW AND SPREADING EAST ACROSS
THE PIEDMONT AS THE DAY PROGRESSES. THUNDER MAY BE LIMITED BY
CLOUD COVER AND LACK OF INSTABILITY ESPECIALLY ACROSS THE WESTERN
HALF OF THE CWA BUT OVERALL CHANCES FOR CONVECTION WILL INCREASE
OVER THE PIEDMONT LATER IN THE DAY WITH POSSIBLY SOME HEATING AND
MORE INSTABILITY. LOCALLY HEAVY RAINFALL WILL BE POSSIBLE AS WELL
WITH STILL VERY HIGH PWATS AHEAD OF THE FRONT. CLOUD COVER AND
HIGH DEWPOINTS WILL KEEP LOWS TONIGHT WELL ABOVE NORMAL RANGING
FROM MID 60S TO LOWER 70S...WITH DIURNAL RANGE LIMITED TOMORROW AS
WELL. HIGHS SHOULD BE 5 TO 8F LOWER THAN TODAYS WARM VALUES.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
AS OF 500 PM EDT WEDNESDAY...
SURFACE COLD FRONT IS EXPECTED TO SLIP SOUTHEAST OF OUR AREA
THURSDAY NIGHT BEFORE STALLING ALONG THE CAROLINA COAST FRIDAY.
MODELS MAINTAIN CONTINUITY WITH DRY HIGH PRESSURE BUILDING INTO
THE FORECAST AREA FROM THE NORTH. IN SPITE OF THE DRY
AIR...THICKNESSES DO NOT FALL THAT MUCH...SO DO NOT EXPECT MUCH IN
THE WAY OF A TEMPERATURE CHANGE. IF ANYTHING...INCREASED SUNSHINE
WILL HELP BOOST SURFACE TEMPERATURES TO AT LEAST OUR JULY NORMALS
FRIDAY...THEN BEGIN WARMING BACK UP SATURDAY AS SOUTHERLY FLOW
INCREASES BEHIND THE DEPARTING SURFACE HIGH.
FOR SATURDAY...MOISTURE WILL BEGIN TO RETURN TO THE FORECAST AREA
FROM THE SOUTH AND SOUTHWEST. CAN`T RULE OUT A LATE AFTERNOON
POPUP SHOWER OVER THE MOUNTAINS...BUT THINK MOST AREAS WILL REMAIN
DRY UNTIL THE ARRIVAL OF A FRONT LATE IN THE WEEKEND. WILL HAVE TO
MONITOR THIS UPSTREAM FRONT CLOSELY AS IT MAY CAST SOME PREFRONTAL
SHOWERS AND STORMS OUR WAY AS EARLY AS SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 515 PM EDT WEDNESDAY...
STRONG COLD FRONT IS SLATED TO CROSS THE FORECAST AREA LATE SUNDAY
INTO MONDAY...ASSOCIATED WITH A VIGOROUS SHORT WAVE TROUGH THAT
WILL BE MOVING ACROSS THE GREAT LAKES AND OHIO VALLEY. THIS
PARTICULARLY STRONG DISTURBANCE...NOTED BY ALL THE
MODELS...PROMISES TO AMPLIFY THE EASTERN LONG WAVE TROUGH...A
PATTERN THAT WILL NET COOLER THAN NORMAL TEMPERATURES FOR SEVERAL
DAYS NEXT WEEK.
DURING THE TRANSITION SUNDAY INTO MONDAY...INCREASED INSTABILITY
AHEAD OF THE FRONT ALONG WITH STRONG DYNAMIC FORCING WILL RESULT
IN POTENTIAL FOR STRONG TO SEVERE STORMS. THE OPPORTUNITY WILL
EXIST FOR ORGANIZED DEEP CONVECTION WITH POTENTIAL FOR A MESOSCALE
CONVECTIVE SYSTEM (MCS) TO CROSS THE FORECAST AREA FROM THE WEST.
ATTM WILL MAINTAIN THE BEST CHANCE FOR SHOWERS/STORMS SUNDAY...WITH
THE THREAT LINGERING INTO MONDAY UNTIL THE SURFACE FRONT CAN
COMPLETELY CLEAR THE FORECAST AREA. GENERALLY FOLLOWED HPC
GUIDANCE THROUGH THE PERIOD TRENDING POPS DOWNWARD AFTER THE EARLY
WEEK FROPA.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 135 AM EDT THURSDAY...
AVIATION CONCERNS THIS MORNING WILL BE CONVECTION THAT IS MOVING
SLOWLY EAST NORTH OF ROA AND NW OF LYH...WITH MAINLY SHOWERS
FURTHER WEST. WILL HAVE VCSH IN THE TAFS FOR NOW THEN SHOULD BE A
BREAK AROUND DAWN-14Z. MODELS ARE DEVELOPING SHOWERS BY 09Z ACROSS
THE NC PIEDMONT AND PUSHING IT TO DAN. NOT SEEING THIS YET...BUT
CONFIDENCE IS MODERATE IN THIS HAPPENING PER DEEP MOISTURE
CONVERGENCE. AMENDMENTS AS NECESSARY WILL OCCUR IF STORMS LOOK TO
PUSH INTO THE TERMINALS.
ASIDE FROM CONVECTION WILL BE DEALING WITH PERIODS OF MVFR FOG DUE
TO HIGHER MOISTURE LEVELS IN PLACE. CLOUDINESS THOUGH SHOULD LIMIT
THE LOWER VSBYS.
STORMS WILL RE-DEVELOP LATE MORNING AS A COLD FRONT MOVES THROUGH
THE AREA. THE COVERAGE OF THE CONVECTION IS NOT EXPECTED TO BE
WIDESPREAD ENOUGH TO INCLUDE IN THE TAF SITES...BUT DID ADD A VCTS
AT ALL TAF SITES. THREAT FOR PRECIPITATION SHOULD END EARLY IN THE
AFTERNOON IN THE WEST AS THE FRONT EXITS THE FORECAST AREA BETWEEN
18Z THUR AND 00Z FRI...LEAVING VFR CONDITIONS.
EXTENDED AVIATION DISCUSSION...
AIRMASS WILL DRY OUT BEHIND THE FRONT GOING INTO FRIDAY-
SATURDAY. OVERALL EXPECT SUB VFR AT TIMES THURSDAY WITH SHRA/TSRA
AND MAYBE SOME FOG THU NIGHT...FOLLOWED BY VFR FRI- SAT OUTSIDE OF
ANY VALLEY FOG AT KLWB/KBCB EACH MORNING.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PC/PH
NEAR TERM...PH
SHORT TERM...PM
LONG TERM...PM
AVIATION...WP
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1037 PM CDT FRI JUL 25 2014
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND SATURDAY
ISSUED AT 227 PM CDT FRI JUL 25 2014
LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH PRESSURE
LOCATED OVER THE EASTERN U.S. AND A TROUGH OF LOW PRESSURE OVER THE
NORTHERN PLAINS. BETWEEN THESE FEATURES...WARM AIR AND MOISTURE
ADVECTION IS ONGOING IN THE LOW AND MID-LEVELS. THIS WEAK FORCING
COMBINED WITH ONE SHORTWAVE OVER EASTERN WISCONSIN AND ANOTHER OVER
NORTH-CENTRAL WISCONSIN HAS CONTRIBUTED TO SPOTTY SHOWER ACTIVITY
OVER THE COURSE OF THE DAY. SHOWERS ARE MAINLY CONFINED TO N-C
WISCONSIN CURRENTLY AS SHOWERS WITH THE EASTERN WISCONSIN SHORTWAVE
HAVE PUSHED SOUTH OF THE AREA. LOOKING UPSTREAM...SCT TO BKN STRATO
CU EXISTS ALL THE WAY INTO THE EASTERN DAKOTAS WHERE DEWPOINTS ARE
PUSHING INTO THE MIDDLE AND UPPER 60S. AS THIS MOISTURE RICH AIR
SPREADS EAST...SMALL SHOWER CHANCES AND CLOUDS ARE THE MAIN FORECAST
CONCERNS.
TONIGHT...AS ONE SHORTWAVE EXITS SOUTHEAST WISCONSIN EARLY THIS
EVENING...ANOTHER WAVE WILL BE DIVING SOUTHEAST OVER NORTHEAST
WISCONSIN. UNTIL THIS WAVE EXITS...WILL LEAVE AT LEAST AN ISOLATED
MENTION OF SHOWERS OVER N-C AND NORTHEAST WISCONSIN UNTIL LATE IN
THE EVENING. THEREAFTER...THOUGH WEAK THETAE ADVECTION WILL STILL
BE OCCURRING IN THE LOW LEVELS...MODELS SHOW MID-LEVEL MOISTURE
DEPARTING BEHIND THE SHORTWAVE AND A DECENT CAP DEVELOPING AROUND
700MB. SO THINK SMALL PRECIP CHANCES WILL END BY LATE IN THE
EVENING...AND THEN GO DRY THE REST OF THE NIGHT. SURFACE DEWPOINTS
WILL BE INCREASING HOWEVER...AND WITH NOCTURNAL COOLING...LOW
STRATUS SHOULD REMAIN RELATIVELY WIDESPREAD AND LOWER THROUGH THE
NIGHT. THIS WILL MAKE FOR A WARMER AND MUGGIER NIGHT THAN THE PAST
FEW WITH LOWS IN THE LOW TO MID 60S.
SATURDAY...AREAS OF STRATUS WILL LINGER INTO THE MORNING HOURS.
WITH DAYTIME HEATING...MIXING SHOULD BE ABLE TO TAP INTO THE DRY AIR
ABOVE THE INVERSION AND HELP TO DIMINISH THE CLOUDS FROM WEST TO
EAST OVER THE COURSE OF THE DAY. LOW LEVEL TEMPS ARE PROJECTED TO
BE QUIET TOASTY TOMORROW AND HAVE RAISED HIGHS A DEGREE OR TWO IN
MOST AREAS. HIGHS IN THE LOW TO MID 80S.
.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY
ISSUED AT 227 PM CDT FRI JUL 25 2014
PCPN TRENDS FOR THE LATTER HALF OF THE WEEKEND...AND THE
POTENTIAL FOR SEVERE TSTMS ON SUNDAY AFTERNOON...WILL BE THE
MAIN FCST CHALLENGES.
MODELS ARE STILL TRYING TO FIND CONCENSUS ON THE TIMING OF THE
STRONG UPPER LEVEL TROF AND CANADIAN COLD FRONT ON SATURDAY NIGHT
AND SUNDAY. SLOWER IS USUALLY THE WAY TO GO WHEN DEALING WITH AN
UPPER LOW...SO HAVE LEANED TOWARD THE SLOWER ECMWF FOR THIS
SYSTEM. THIS WOULD SUGGEST A CHANCE OF TSTMS OVER THE NORTHWEST
THIRD OF GRB CWA AFTER MIDNIGHT SATURDAY NIGHT...THEN LIKELY POPS
SPREADING SE ACROSS THE FORECAST AREA ON SUNDAY. IF THE ECMWF
VERIFIES...ITS SLOWER MOVMT WOULD ALLOW FOR A LITTLE MORE HEATING
AND INSTABILITY IN ADVANCE OF THE SYSTEM...AND POTENTIALLY A
LITTLE GREATER THREAT OF SVR TSTMS OVER THE SE HALF OF THE
FORECAST AREA. MODIFIED FCST SOUNDINGS SUGGEST CAPE AROUND
1000-1500 J/KG...LI`S -3 TO -5...AND FAVORABLE WET BULB ZERO HGTS
OF 9.5-10K FT. DEEP LAYER SHEAR IS EXPECTED TO BE 25 TO 35 KTS
IN ADVANCE OF THE COLD FRONT AROUND MIDDAY...BUT SHOULD QUICKLY
WEAKEN AS THE UPPER TROF ARRIVES LATE IN THE DAY. ALTHOUGH A
SIGNIFICANT SVR WX EVENT IS NOT LIKELY DUE TO WIDESPREAD
CLOUDS/SHOWERS...WE CANNOT RULE OUT A FEW SVR TSTMS WITH LARGE
HAIL OVER PARTS OF NE/C/EC WI DURING THE AFTERNOON...SO WILL
CONTINUE TO MENTION THIS THREAT IN THE HWO.
THE EXTENDED FCST FOR THE UPCOMING WORK WEEK IS EXPECTED TO BE
AT OR A LITTLE COOLER THAN COOLER THAN NORMAL...WITH SCATTERED
SHOWERS AND TSTMS...MAINLY DURING THE AFTERNOONS AND EARLY
EVENINGS. A STRONG UPPER LEVEL RIDGE WILL BE SITUATED OVER THE
ROCKIES...WITH A LARGE UPPER TROF OVER THE EASTERN U.S. AND
EASTERN CANADA. ALTHOUGH S/W TROFS IN THE NW FLOW MAY GENERATE
SOME PCPN AT TIMES...IT APPEARS THAT MOST OF THE RAIN WILL BE
DIURNALLY-DRIVEN DUE TO DAYTIME HEATING/INSTABILITY.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1033 PM CDT FRI JUL 25 2014
SOME HOLES DEVELOPING IN THE OVERCAST OVER STATE. EXPECT WILL FILL
IN THROUGH THE NIGHT...THOUGH MAY LEAD TO BIT MORE FOG THAN
THOUGHT PREVIOUSLY. WILL STAY WITH MVFR VSBY GIVEN WIND AT THIS
TIME. LIGHT SHOWER ACTIVITY PASSING THROUGH FAR NORTH...THOUGH
EXPECT DRY CONDITIONS TO CONTINUE AT TAF SITES. RELATIVELY QUICK
IMPROVEMENT TO THE CIGS/VSBYS SHOULD OCCUR TOMORROW MORNING WITH
DAYTIME HEATING AND MIXING. &&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......KIECKBUSCH
AVIATION.......TE
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
709 PM CDT FRI JUL 25 2014
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND SATURDAY
ISSUED AT 227 PM CDT FRI JUL 25 2014
LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH PRESSURE
LOCATED OVER THE EASTERN U.S. AND A TROUGH OF LOW PRESSURE OVER THE
NORTHERN PLAINS. BETWEEN THESE FEATURES...WARM AIR AND MOISTURE
ADVECTION IS ONGOING IN THE LOW AND MID-LEVELS. THIS WEAK FORCING
COMBINED WITH ONE SHORTWAVE OVER EASTERN WISCONSIN AND ANOTHER OVER
NORTH-CENTRAL WISCONSIN HAS CONTRIBUTED TO SPOTTY SHOWER ACTIVITY
OVER THE COURSE OF THE DAY. SHOWERS ARE MAINLY CONFINED TO N-C
WISCONSIN CURRENTLY AS SHOWERS WITH THE EASTERN WISCONSIN SHORTWAVE
HAVE PUSHED SOUTH OF THE AREA. LOOKING UPSTREAM...SCT TO BKN STRATO
CU EXISTS ALL THE WAY INTO THE EASTERN DAKOTAS WHERE DEWPOINTS ARE
PUSHING INTO THE MIDDLE AND UPPER 60S. AS THIS MOISTURE RICH AIR
SPREADS EAST...SMALL SHOWER CHANCES AND CLOUDS ARE THE MAIN FORECAST
CONCERNS.
TONIGHT...AS ONE SHORTWAVE EXITS SOUTHEAST WISCONSIN EARLY THIS
EVENING...ANOTHER WAVE WILL BE DIVING SOUTHEAST OVER NORTHEAST
WISCONSIN. UNTIL THIS WAVE EXITS...WILL LEAVE AT LEAST AN ISOLATED
MENTION OF SHOWERS OVER N-C AND NORTHEAST WISCONSIN UNTIL LATE IN
THE EVENING. THEREAFTER...THOUGH WEAK THETAE ADVECTION WILL STILL
BE OCCURRING IN THE LOW LEVELS...MODELS SHOW MID-LEVEL MOISTURE
DEPARTING BEHIND THE SHORTWAVE AND A DECENT CAP DEVELOPING AROUND
700MB. SO THINK SMALL PRECIP CHANCES WILL END BY LATE IN THE
EVENING...AND THEN GO DRY THE REST OF THE NIGHT. SURFACE DEWPOINTS
WILL BE INCREASING HOWEVER...AND WITH NOCTURNAL COOLING...LOW
STRATUS SHOULD REMAIN RELATIVELY WIDESPREAD AND LOWER THROUGH THE
NIGHT. THIS WILL MAKE FOR A WARMER AND MUGGIER NIGHT THAN THE PAST
FEW WITH LOWS IN THE LOW TO MID 60S.
SATURDAY...AREAS OF STRATUS WILL LINGER INTO THE MORNING HOURS.
WITH DAYTIME HEATING...MIXING SHOULD BE ABLE TO TAP INTO THE DRY AIR
ABOVE THE INVERSION AND HELP TO DIMINISH THE CLOUDS FROM WEST TO
EAST OVER THE COURSE OF THE DAY. LOW LEVEL TEMPS ARE PROJECTED TO
BE QUIET TOASTY TOMORROW AND HAVE RAISED HIGHS A DEGREE OR TWO IN
MOST AREAS. HIGHS IN THE LOW TO MID 80S.
.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY
ISSUED AT 227 PM CDT FRI JUL 25 2014
PCPN TRENDS FOR THE LATTER HALF OF THE WEEKEND...AND THE
POTENTIAL FOR SEVERE TSTMS ON SUNDAY AFTERNOON...WILL BE THE
MAIN FCST CHALLENGES.
MODELS ARE STILL TRYING TO FIND CONCENSUS ON THE TIMING OF THE
STRONG UPPER LEVEL TROF AND CANADIAN COLD FRONT ON SATURDAY NIGHT
AND SUNDAY. SLOWER IS USUALLY THE WAY TO GO WHEN DEALING WITH AN
UPPER LOW...SO HAVE LEANED TOWARD THE SLOWER ECMWF FOR THIS
SYSTEM. THIS WOULD SUGGEST A CHANCE OF TSTMS OVER THE NORTHWEST
THIRD OF GRB CWA AFTER MIDNIGHT SATURDAY NIGHT...THEN LIKELY POPS
SPREADING SE ACROSS THE FORECAST AREA ON SUNDAY. IF THE ECMWF
VERIFIES...ITS SLOWER MOVMT WOULD ALLOW FOR A LITTLE MORE HEATING
AND INSTABILITY IN ADVANCE OF THE SYSTEM...AND POTENTIALLY A
LITTLE GREATER THREAT OF SVR TSTMS OVER THE SE HALF OF THE
FORECAST AREA. MODIFIED FCST SOUNDINGS SUGGEST CAPE AROUND
1000-1500 J/KG...LI`S -3 TO -5...AND FAVORABLE WET BULB ZERO HGTS
OF 9.5-10K FT. DEEP LAYER SHEAR IS EXPECTED TO BE 25 TO 35 KTS
IN ADVANCE OF THE COLD FRONT AROUND MIDDAY...BUT SHOULD QUICKLY
WEAKEN AS THE UPPER TROF ARRIVES LATE IN THE DAY. ALTHOUGH A
SIGNIFICANT SVR WX EVENT IS NOT LIKELY DUE TO WIDESPREAD
CLOUDS/SHOWERS...WE CANNOT RULE OUT A FEW SVR TSTMS WITH LARGE
HAIL OVER PARTS OF NE/C/EC WI DURING THE AFTERNOON...SO WILL
CONTINUE TO MENTION THIS THREAT IN THE HWO.
THE EXTENDED FCST FOR THE UPCOMING WORK WEEK IS EXPECTED TO BE
AT OR A LITTLE COOLER THAN COOLER THAN NORMAL...WITH SCATTERED
SHOWERS AND TSTMS...MAINLY DURING THE AFTERNOONS AND EARLY
EVENINGS. A STRONG UPPER LEVEL RIDGE WILL BE SITUATED OVER THE
ROCKIES...WITH A LARGE UPPER TROF OVER THE EASTERN U.S. AND
EASTERN CANADA. ALTHOUGH S/W TROFS IN THE NW FLOW MAY GENERATE
SOME PCPN AT TIMES...IT APPEARS THAT MOST OF THE RAIN WILL BE
DIURNALLY-DRIVEN DUE TO DAYTIME HEATING/INSTABILITY.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 702 PM CDT FRI JUL 25 2014
INCREASING LOW LEVEL MOISTURE WILL KEEP CLOUDS IN PLACE THROUGH
THE NIGHT WITH CIGS LOWERING INTO IFR/MVFR RANGES. LIGHT FOG
POSSIBLE...BUT RECENT DRY SPELL AND LIGHT GRADIENT SHOULD KEEP IT
FROM BECOMING DENSE. SOME MODELS CONTINUE BRINGING SMALL CHANCE OF
PCPN INTO NORTHERN WI OVERNIGHT. TOO SMALL A CHANCE TO ADD TO TAFS
AT THIS TIME. RELATIVELY QUICK IMPROVEMENT TO THE CIGS/VSBYS SHOULD
OCCUR TOMORROW MORNING WITH DAYTIME HEATING AND MIXING. &&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......KIECKBUSCH
AVIATION.......TE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
550 PM CDT THU JUL 24 2014
.UPDATE...
ISSUED AT 550 PM CDT THU JUL 24 2014
HAVING SOME SERIOUS CONCERNS WITH THE PRECIPITATION CHANCES THIS
EVENING...AND POSSIBLY OVERNIGHT TOO.
CURRENTLY...WATER VAPOR LOOP AND RADAR IMAGERY SHOWED A COMPLEX
OF SHOWERS AND STORMS DROPPING SOUTH...NOW INTO NORTHWEST AND
NORTH CENTRAL IOWA. THE EASTWARD PROGRESSION OF THE PRECIPITATION
TOWARDS THE FORECAST AREA HAS COME TO A HALT DUE TO THE COMPLEX
MOTION...ALONG WITH PLENTIFUL DRY AIR OVER THE FORECAST AREA.
2030Z TAMDAR SOUNDING FROM MSP SHOWED 10C OR HIGHER DEWPOINT
DEPRESSIONS FROM 770-600MB AND A DEEP INVERTED-V AT 800MB.
SUBSIDENCE IN THE WAKE OF THIS COMPLEX SHOWING UP AS A SIGNIFICANT
AREA OF CLEARING OVER WEST-CENTRAL MN...DRYING IN THE SAME
LOCATION ON WATER VAPOR...AND SURFACE PRESSURE FALLS UP TO 2
MB/HR.
ITS TOUGH FINDING A MODEL WITH A GREAT HANDLE ON THIS CURRENT
COMPLEX. THE 24.21Z RAP...24.19Z HRRR AND 24.18Z GFS SEEM TO BE
THE BEST AND ALL THREE SUGGEST THAT THE EVENING MAY NOW END UP
DRY ACROSS THE FORECAST AREA. THIS SEEMS REASONABLE AS THE
SUBSIDENCE COMES INTO THE FORECAST AREA IN THE WAKE OF THE
COMPLEX. IN FACT...GIVEN THE CLEARING UPSTREAM...ITS POSSIBLE
THAT CLEARING COMES INTO THE AREA. NEXT CONCERN THEN TURNS TO THE
OVERNIGHT CONVECTION POSSIBILITIES. WITH SUBSIDENCE AND COLD POOL
IN PLACE OVER MN AND NORTH CENTRAL IOWA...WHEN THE LOW LEVEL JET
INCREASES TONIGHT...THE CONVECTION MAY END FIRING MORE ALONG THE
WESTERN MN/IOWA BORDER. THE AFOREMENTIONED MODELS ALONG WITH THE
24.12Z ECMWF AND EVEN TO SOME DEGREE THE 24.18Z NAM ALL SHOW THAT
IDEA. IF THE CONVECTION DEVELOPS AN MCV...THEN THE CONVECTION WILL
DROP SOUTHEAST AND STAY MOSTLY WEST OF THE FORECAST AREA. THIS IS
WHAT THE 24.18Z NAM AND 24.12Z HIRES-ARW SUGGESTED. HOWEVER...IF
NO MCV FORMS...A FRONTOGENETICAL BAND OF SHOWERS AND EMBEDDED
STORMS WOULD MOVE WEST TO EAST INTO THE FORECAST AREA AFTER
07Z...PERHAPS REACHING THE MS RIVER BY 12Z.
FOR NOW...HAVE TRENDED PRECIPITATION CHANCES DOWN SOME FOR THE
EVENING AND FURTHER DECREASES ARE POSSIBLE. HAVE NOT ADJUSTED THE
OVERNIGHT YET...BUT COULD SEE A NEED TO DECREASE PRECIPITATION
CHANCES ALONG/EAST OF THE MS RIVER. NEEDLESS TO SAY THE
PRECIPITATION CHANCES FOR TONIGHT IS A FLUID SITUATION.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 320 PM CDT THU JUL 24 2014
MAIN FORECAST PROBLEM WAS THE STORMS/WEATHER MOVING IN OVERNIGHT
INTO FRIDAY MORNING.
A TALE OF TWO AIR MASSES ACROSS THE REGION THIS MORNING IN THE
OBSERVATIONAL DATA. 24.12Z RAOBS SHOWING STEEP 700-500MB LAPSE RATES
OVER THE WESTERN DAKOTAS /9C PER KM/ AND MID-LEVEL SATURATION
OCCURRING ON THE EASTERN EDGE OF THE DEEPER N-S MOIST PLUME IN
PLACE. PRECIPITABLE WATER /PWAT/ VALUES AT KBIS/KABR BOTH ARE BOTH
OVER 125 PERCENT THIS MORNING. KBIS AND KABR SOUNDINGS BOTH SHOW
SATURATION AROUND 700MB WITH 500-1000J/KG OF ELEVATED CAPE ABOVE
700MB. EAST OF THE MOIST PLUME...STABILITY REIGNS WITH 5-6C/KM
500-700MB LAPSE RATES AND BELOW NORMAL PWAT VALUES /65 PERCENT/ AT
KMPX. THIS GRADIENT AND MOISTURE TRANSPORT CONVERGENCE OVER THE
DAKOTAS/MN BORDER AT 16Z MATCHED WELL WITH THE MORNING STORMS AND
WEATHER IN THE DAKOTAS. THIS ALL ENHANCED BY A VERY VISIBLE
SHORTWAVE TROUGH SEWRD OF KBIS AND ANOTHER NORTH OF THE MT/ND/SRN
CANADA BORDER.
AS THE LARGE SCALE SHIFTS OVER NORTH AMERICA AND THE LONG WAVE
TROUGH OVER THE EAST WEAKENS...FLAT RIDGING BUILDS ACROSS THE
NORTHERN STATES /THROUGH SATURDAY/. THIS WILL PROMOTE WARMING AND
RICHER MOISTURE TO MOVE INTO THE REGION FOR A PERIOD...BEFORE
REAMPLIFICATION OF THE TROUGH OVER THE ERN CONUS OCCURS /SUNDAY/.
BEGINNING OVERNIGHT...THE DAKOTAS AIR MASS WILL ADVECT EASTWARD
AND INTO THE AREA. THIS AIRMASS IS CHARACTERIZED BY HIGHER
MOISTURE BUT ALSO VERY WARM TEMPERATURES ALOFT AS AN ELEVATED
MIXED LAYER MOVES IN. WHILE THIS HAS STEEP MID-LEVEL LAPSE
RATES...THE 700MB TEMPERATURES WARM FROM 8C TO 12-14C
FRIDAY...PROVIDING A STOUT CAPPING INVERSION TO SURFACE BASED
CONVECTION BY AFTERNOON. THIS TRANSLATES TO A 600 J/KG SBCIN. THIS
CAP BUILDING HAS VERY GOOD CONSENSUS AMOUNT THE DETERMINISTIC MODELS...AND
HAVE LOWERED RAIN CHANCES FRIDAY AFTERNOON ACCORDINGLY.
PRIOR TO THE ELEVATED MIXED LAYER BUILDING IN FRIDAY...LOW-LEVEL
WARM ADVECTION AND MOISTURE TRANSPORT INCREASES WITH HEIGHT FALLS
AND INCREASED SOUTHERLY FLOW OVERNIGHT. THIS EVENING THERE IS SOME
SIGNAL FOR MID-LEVEL MOISTURE TRANSPORT CONVERGENCE /700MB/ TO
MOVE IN FROM THE WEST DURING THE EVENING AND LAPSE RATES WOULD SAY
SOME MID-LEVEL TOWERING CU COULD DEVELOP SOME SHOWERS
/100-300J/KG MUCAPE/. HAVE BEEN MONITORING THE CONVECTION ENTERING
WESTERN MN AND WHILE MUCAPE VALUES HAVE INCREASED A FEW HUNDRED
FROM 15-18Z...MUCH OF MN IS STILL QUITE STABLE. HOWEVER...THE
NORTHERN SIDE SEEMS TO BE TIED TO THE 700 MB TRANSPORT CONVERGENCE
AND SHORTWAVE TROUGH APPROACHING FARGO. WOULD EXPECT ECHO TO
WEAKEN AS IT MOVES TOWARD I-35...ALTHOUGH THERE IS WEAK
FORCING...THE AIR MASS IS VERY DRY. WILL HAVE TO MONITOR...BUT
TIMING LOOKS TO FIT THE EVENING INCREASE OF PRECIPITATION CHANCES.
BY MIDNIGHT...AS THE RIDGE BUILDS EAST...MOISTURE TRANSPORT AND A 40-
50KT LOW-LEVEL JET AT 850 MB FEED THE EASTERN EDGE OF THE MOISTURE
PLUME UP THE . BY 09Z...A MESOSCALE CONVECTIVE SYSTEM IS EXPECTED
TO ENTER THE WESTERN FORECAST AREA ON VERY STRONG MOISTURE
TRANSPORT CONVERGENCE AT 850 MB /50KTS DECREASING TO 15 KTS...KDSM
TO KLSE/. THIS SIGNAL IS VERY CONSISTENT AMONG THE 24.12Z MODELS
AND LATEST RAP GUIDANCE. CORFIDI VECTORS SUGGEST SOUTHEAST
MOVEMENT TO THE STRONGER CONVECTIVE ELEMENTS...AND THIS COULD POSE
SOME PROBLEMS WITH THE COMPLEX MISSING TO THE SOUTHWEST. WITH THE
MOISTURE TRANSPORT CONVERGENCE INTO THE HEART OF THE FORECAST
AREA...WOULD THINK A MISS IS PROBABLY UNLIKELY. THIS WOULD FAVOR
THE AREAS SOUTHWEST OF I-94...ESPECIALLY INTO NORTHEAST IOWA AND
LITTLE CHANGE TO THE RAIN CHANCES WERE MADE.
PRECIPITABLE WATER VALUES INCREASE RAPIDLY OVERNIGHT WITH OVER
1.75 INCHES IN THE AREA BY MORNING AND WARM CLOUD DEPTHS OF 4 KM.
THUS HEAVY RAINFALL RATES WILL OCCUR IN THE SYSTEM...BUT MANY
AREAS CAN USE THE RAINS. SOME BRIEF CITY FLOODING IS POSSIBLE.
ISOLATED HAIL AND GUSTY WINDS HAVE BEEN ADDED TO AREAS WEST OF THE
MISS RIVER IN THE HAZ WEATHER OUTLOOK DUE TO THE MAGNITUDE OF
CONVERGENCE/FORCING AND ABOUT 1500 J/KG OF MUCAPE. SPC HAS ALSO
SHIFTED THEIR DAY 1 CONVECTIVE OUTLOOK TO NEAR OUR WESTERN
FORECAST AREA EDGE...WHICH IS APPROPRIATE. CAPPING SHOULD THEN
BUILD IN AND THE SYSTEM MOVES EAST/SOUTHEAST IN THE AFTERNOON.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 320 PM CDT THU JUL 24 2014
FRIDAY NIGHT POSES AN INTERESTING PROBLEM IN SRN WISCONSIN AS THE
CAP IS STILL FULLY IN PLACE WITH NO SURFACE BASED CONVECTION
ALLOWED PER ALL GUIDANCE /600 SBCIN AND 700MB TEMPS NEAR 14C/.
YET A HANDFUL OF DETERMINISTIC MODELS CONTINUE A SIGNAL OF QPF
ACROSS SRN WISCONSIN IN THE EVENING. HAVE KEPT A SMALL RAIN CHANCE
THERE AS IT WOULD BE SOME MID-LEVEL INSTABILITY THAT WOULD HAVE TO
BE TAPPED NORTH OF THE SURFACE LOW SHIFTING THROUGH ERN IA. THE
24.12Z NAM DOES HAVE SOME 900-800MB FRONOTGENESIS WORKING WITHIN
THE CAPPED AREA...AND POSSIBLY SOME ISENTROPIC LIFT GENERATES
STABLE SHOWERS. PREFER THE 24.12Z NAM WITH RAINFALL SOUTH OF THE
FORECAST AREA...BUT HAVE KEPT A SLIGHT CHANCE OF RAIN TO COVER
THIS SITUATION FRIDAY EVENING.
A DRYING TREND THEN IN NORTHWEST FLOW AFTER MIDNIGHT...THROUGH
SATURDAY PROVIDES A VERY NICE DRY DAY. THE HIGH PRECIPITABLEWATER
AIRMASS SHOULD PUSH SOUTH TO NEAR I-80 CORRIDOR.
STRONG QG CONVERGENCE FORCING MOVES IN SUNDAY WITH THE STRONG
TROUGH MOVING THROUGH MN/WI AS THE LONG WAVE AMPLIFIES AGAIN OVER
THE EASTERN CONUS. FORCING COMES IN LATER SATURDAY NIGHT AND IS
STRONGEST SUNDAY WITH SOME INSTABILITY. HAVE INCREASED RAIN
CHANCES FOR SUNDAY. RAIN CHANCES MAY NEED TO BE PULLED FURTHER
SOUTHWEST AS WELL DEPENDING ON THE WAVE TRACK. A CLOUDY BREEZY
SHOWERY DAY FOR MOST AREAS IT SEEMS.
MONDAY THROUGH THURSDAY HAVE BELOW NORMAL TEMPERATURES AND MOSTLY
DRY WEATHER UNDER THE INFLUENCE OF THE LONGWAVE TROUGH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1239 PM CDT THU JUL 24 2014
THE MAIN FOCUS THROUGH TOMORROW AFTERNOON IS ON WHEN THE HIGHEST
CHANCES FOR RAIN SHOWERS AND THUNDERSTORMS WILL BE TONIGHT.
CONDITIONS WILL STAY DRY THROUGH THE AFTERNOON WITH CONVECTION
DEVELOPING THIS EVENING AND BECOMING MORE WIDESPREAD OVERNIGHT ON
INTO TOMORROW MORNING. RAIN SHOWERS AND THUNDERSTORMS LOOK LIKELY
OVER THIS PERIOD...SO HAVE TAKEN VISIBILITIES DOWN A BIT...BUT
DID NOT WANT TO ADD IN ANY TEMPO GROUPS FOR IFR YET SINCE THERE IS
A CHANCE THAT THE MAIN THUNDERSTORMS COULD BE TO THE SOUTHWEST OF
RST/LSE. THIS CONVECTION SHOULD TRACK TO THE EAST LATE FRIDAY
MORNING WITH WINDS PICKING UP OUT OF THE SOUTH IN ITS WAKE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...AJ
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
319 PM CDT THU JUL 24 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 320 PM CDT THU JUL 24 2014
MAIN FORECAST PROBLEM WAS THE STORMS/WEATHER MOVING IN OVERNIGHT
INTO FRIDAY MORNING.
A TALE OF TWO AIR MASSES ACROSS THE REGION THIS MORNING IN THE
OBSERVATIONAL DATA. 24.12Z RAOBS SHOWING STEEP 700-500MB LAPSE RATES
OVER THE WESTERN DAKOTAS /9C PER KM/ AND MID-LEVEL SATURATION
OCCURRING ON THE EASTERN EDGE OF THE DEEPER N-S MOIST PLUME IN
PLACE. PRECIPITABLE WATER /PWAT/ VALUES AT KBIS/KABR BOTH ARE BOTH
OVER 125 PERCENT THIS MORNING. KBIS AND KABR SOUNDINGS BOTH SHOW
SATURATION AROUND 700MB WITH 500-1000J/KG OF ELEVATED CAPE ABOVE
700MB. EAST OF THE MOIST PLUME...STABILITY REIGNS WITH 5-6C/KM
500-700MB LAPSE RATES AND BELOW NORMAL PWAT VALUES /65 PERCENT/ AT
KMPX. THIS GRADIENT AND MOISTURE TRANSPORT CONVERGENCE OVER THE
DAKOTAS/MN BORDER AT 16Z MATCHED WELL WITH THE MORNING STORMS AND
WEATHER IN THE DAKOTAS. THIS ALL ENHANCED BY A VERY VISIBLE
SHORTWAVE TROUGH SEWRD OF KBIS AND ANOTHER NORTH OF THE MT/ND/SRN
CANADA BORDER.
AS THE LARGE SCALE SHIFTS OVER NORTH AMERICA AND THE LONG WAVE
TROUGH OVER THE EAST WEAKENS...FLAT RIDGING BUILDS ACROSS THE
NORTHERN STATES /THROUGH SATURDAY/. THIS WILL PROMOTE WARMING AND
RICHER MOISTURE TO MOVE INTO THE REGION FOR A PERIOD...BEFORE
REAMPLIFICATION OF THE TROUGH OVER THE ERN CONUS OCCURS /SUNDAY/.
BEGINNING OVERNIGHT...THE DAKOTAS AIR MASS WILL ADVECT EASTWARD
AND INTO THE AREA. THIS AIRMASS IS CHARACTERIZED BY HIGHER
MOISTURE BUT ALSO VERY WARM TEMPERATURES ALOFT AS AN ELEVATED
MIXED LAYER MOVES IN. WHILE THIS HAS STEEP MID-LEVEL LAPSE
RATES...THE 700MB TEMPERATURES WARM FROM 8C TO 12-14C
FRIDAY...PROVIDING A STOUT CAPPING INVERSION TO SURFACE BASED
CONVECTION BY AFTERNOON. THIS TRANSLATES TO A 600 J/KG SBCIN. THIS
CAP BUILDING HAS VERY GOOD CONSENSUS AMOUNT THE DETERMINISTIC MODELS...AND
HAVE LOWERED RAIN CHANCES FRIDAY AFTERNOON ACCORDINGLY.
PRIOR TO THE ELEVATED MIXED LAYER BUILDING IN FRIDAY...LOW-LEVEL
WARM ADVECTION AND MOISTURE TRANSPORT INCREASES WITH HEIGHT FALLS
AND INCREASED SOUTHERLY FLOW OVERNIGHT. THIS EVENING THERE IS SOME
SIGNAL FOR MID-LEVEL MOISTURE TRANSPORT CONVERGENCE /700MB/ TO
MOVE IN FROM THE WEST DURING THE EVENING AND LAPSE RATES WOULD SAY
SOME MID-LEVEL TOWERING CU COULD DEVELOP SOME SHOWERS
/100-300J/KG MUCAPE/. HAVE BEEN MONITORING THE CONVECTION ENTERING
WESTERN MN AND WHILE MUCAPE VALUES HAVE INCREASED A FEW HUNDRED
FROM 15-18Z...MUCH OF MN IS STILL QUITE STABLE. HOWEVER...THE
NORTHERN SIDE SEEMS TO BE TIED TO THE 700 MB TRANSPORT CONVERGENCE
AND SHORTWAVE TROUGH APPROACHING FARGO. WOULD EXPECT ECHO TO
WEAKEN AS IT MOVES TOWARD I-35...ALTHOUGH THERE IS WEAK
FORCING...THE AIR MASS IS VERY DRY. WILL HAVE TO MONITOR...BUT
TIMING LOOKS TO FIT THE EVENING INCREASE OF PRECIPITATION CHANCES.
BY MIDNIGHT...AS THE RIDGE BUILDS EAST...MOISTURE TRANSPORT AND A 40-
50KT LOW-LEVEL JET AT 850 MB FEED THE EASTERN EDGE OF THE MOISTURE
PLUME UP THE . BY 09Z...A MESOSCALE CONVECTIVE SYSTEM IS EXPECTED
TO ENTER THE WESTERN FORECAST AREA ON VERY STRONG MOISTURE
TRANSPORT CONVERGENCE AT 850 MB /50KTS DECREASING TO 15 KTS...KDSM
TO KLSE/. THIS SIGNAL IS VERY CONSISTENT AMONG THE 24.12Z MODELS
AND LATEST RAP GUIDANCE. CORFIDI VECTORS SUGGEST SOUTHEAST
MOVEMENT TO THE STRONGER CONVECTIVE ELEMENTS...AND THIS COULD POSE
SOME PROBLEMS WITH THE COMPLEX MISSING TO THE SOUTHWEST. WITH THE
MOISTURE TRANSPORT CONVERGENCE INTO THE HEART OF THE FORECAST
AREA...WOULD THINK A MISS IS PROBABLY UNLIKELY. THIS WOULD FAVOR
THE AREAS SOUTHWEST OF I-94...ESPECIALLY INTO NORTHEAST IOWA AND
LITTLE CHANGE TO THE RAIN CHANCES WERE MADE.
PRECIPITABLE WATER VALUES INCREASE RAPIDLY OVERNIGHT WITH OVER
1.75 INCHES IN THE AREA BY MORNING AND WARM CLOUD DEPTHS OF 4 KM.
THUS HEAVY RAINFALL RATES WILL OCCUR IN THE SYSTEM...BUT MANY
AREAS CAN USE THE RAINS. SOME BRIEF CITY FLOODING IS POSSIBLE.
ISOLATED HAIL AND GUSTY WINDS HAVE BEEN ADDED TO AREAS WEST OF THE
MISS RIVER IN THE HAZ WEATHER OUTLOOK DUE TO THE MAGNITUDE OF
CONVERGENCE/FORCING AND ABOUT 1500 J/KG OF MUCAPE. SPC HAS ALSO
SHIFTED THEIR DAY 1 CONVECTIVE OUTLOOK TO NEAR OUR WESTERN
FORECAST AREA EDGE...WHICH IS APPROPRIATE. CAPPING SHOULD THEN
BUILD IN AND THE SYSTEM MOVES EAST/SOUTHEAST IN THE AFTERNOON.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 320 PM CDT THU JUL 24 2014
FRIDAY NIGHT POSES AN INTERESTING PROBLEM IN SRN WISCONSIN AS THE
CAP IS STILL FULLY IN PLACE WITH NO SURFACE BASED CONVECTION
ALLOWED PER ALL GUIDANCE /600 SBCIN AND 700MB TEMPS NEAR 14C/.
YET A HANDFUL OF DETERMINISTIC MODELS CONTINUE A SIGNAL OF QPF
ACROSS SRN WISCONSIN IN THE EVENING. HAVE KEPT A SMALL RAIN CHANCE
THERE AS IT WOULD BE SOME MID-LEVEL INSTABILITY THAT WOULD HAVE TO
BE TAPPED NORTH OF THE SURFACE LOW SHIFTING THROUGH ERN IA. THE
24.12Z NAM DOES HAVE SOME 900-800MB FRONOTGENESIS WORKING WITHIN
THE CAPPED AREA...AND POSSIBLY SOME ISENTROPIC LIFT GENERATES
STABLE SHOWERS. PREFER THE 24.12Z NAM WITH RAINFALL SOUTH OF THE
FORECAST AREA...BUT HAVE KEPT A SLIGHT CHANCE OF RAIN TO COVER
THIS SITUATION FRIDAY EVENING.
A DRYING TREND THEN IN NORTHWEST FLOW AFTER MIDNIGHT...THROUGH
SATURDAY PROVIDES A VERY NICE DRY DAY. THE HIGH PRECIPITABLEWATER
AIRMASS SHOULD PUSH SOUTH TO NEAR I-80 CORRIDOR.
STRONG QG CONVERGENCE FORCING MOVES IN SUNDAY WITH THE STRONG
TROUGH MOVING THROUGH MN/WI AS THE LONG WAVE AMPLIFIES AGAIN OVER
THE EASTERN CONUS. FORCING COMES IN LATER SATURDAY NIGHT AND IS
STRONGEST SUNDAY WITH SOME INSTABILITY. HAVE INCREASED RAIN
CHANCES FOR SUNDAY. RAIN CHANCES MAY NEED TO BE PULLED FURTHER
SOUTHWEST AS WELL DEPENDING ON THE WAVE TRACK. A CLOUDY BREEZY
SHOWERY DAY FOR MOST AREAS IT SEEMS.
MONDAY THROUGH THURSDAY HAVE BELOW NORMAL TEMPERATURES AND MOSTLY
DRY WEATHER UNDER THE INFLUENCE OF THE LONGWAVE TROUGH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1239 PM CDT THU JUL 24 2014
THE MAIN FOCUS THROUGH TOMORROW AFTERNOON IS ON WHEN THE HIGHEST
CHANCES FOR RAIN SHOWERS AND THUNDERSTORMS WILL BE TONIGHT.
CONDITIONS WILL STAY DRY THROUGH THE AFTERNOON WITH CONVECTION
DEVELOPING THIS EVENING AND BECOMING MORE WIDESPREAD OVERNIGHT ON
INTO TOMORROW MORNING. RAIN SHOWERS AND THUNDERSTORMS LOOK LIKELY
OVER THIS PERIOD...SO HAVE TAKEN VISIBILITIES DOWN A BIT...BUT
DID NOT WANT TO ADD IN ANY TEMPO GROUPS FOR IFR YET SINCE THERE IS
A CHANCE THAT THE MAIN THUNDERSTORMS COULD BE TO THE SOUTHWEST OF
RST/LSE. THIS CONVECTION SHOULD TRACK TO THE EAST LATE FRIDAY
MORNING WITH WINDS PICKING UP OUT OF THE SOUTH IN ITS WAKE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS MIAMI FL
131 AM EDT SAT JUL 26 2014
.AVIATION...SCATTERED THUNDERSTORMS ARE FORECAST TO DEVELOP LATER
THIS MORNING AND CONTINUE THROUGH THE AFTERNOON. HRRR SHOWS
ACTIVITY DEVELOPING ALONG BOTH COASTS. SO HAVE INCLUDED VCTS FOR
ALL TERMINALS BEGINNING LATE MORNING AND CONTINUING THROUGH EARLY
EVENING. BRIEF IFR WILL BE POSSIBLE AND WILL MONITOR RADAR TRENDS
FOR AMENDMENTS IF NECESSARY LATER TODAY. LIGHT WINDS WILL BECOME
ONSHORE THIS AFTERNOON AT 5-10 KT. WINDS WILL BE VARIABLE AND
GUSTY IN AND NEAR THUNDERSTORMS. /GREGORIA
&&
.PREV DISCUSSION... /ISSUED 939 PM EDT FRI JUL 25 2014/
UPDATE...
OUTSIDE OF A FEW MINOR TWEAKS WITHIN THE GRIDDED FORECAST PACKAGE
BASED ON THE LATEST OBSERVATIONS AROUND THE LOCAL AREA...NO MAJOR
UPDATES ARE ANTICIPATED AS THE PREVIOUS FORECAST PACKAGE REMAINS
ON TRACK. THE STORMS THAT HAVE DEVELOPED ALONG THE BOUNDARY
EXTENDING NORTHWARD ACROSS INLAND BROWARD AND PALM BEACH COUNTIES
SHOULD BEGIN TO DIMINISH THROUGH THE LATE EVENING HOURS. THE BEST
CHANCE FOR OVERNIGHT SHOWERS WILL REMAIN OVER THE ADJACENT
ATLANTIC WATERS. 85/AG
PREV DISCUSSION... /ISSUED 733 PM EDT FRI JUL 25 2014/
AVIATION...
VFR CONDITIONS TO PREVAIL AT ALL SITES THROUGH THE NEXT 24 HOURS
OUTSIDE OF ANY THUNDERSTORMS. MAINLY ESE WINDS SHOULD PERSIST
OVERNIGHT BEFORE BECOMING LIGHT AND VARIABLE. A FEW STORMS ARE
LINGERING MAINLY ACROSS INTERIOR PORTIONS OF MIAMI-
DADE...BROWARD...AND PALM BEACH COUNTIES TONIGHT DUE TO BOUNDARY
INTERACTIONS. THESE STORMS ARE WEAKENING AND SHOULD STAY AWAY FROM
THE EAST COAST SITES. SOUTHEAST FLOW TO RETURN TOMORROW AFTERNOON
WITH A GULF BREEZE AT KAPF.
PREV DISCUSSION... /ISSUED 214 PM EDT FRI JUL 25 2014/
SHORT TERM (TONIGHT-SUNDAY NIGHT)...
DEEP LAYER RIDGE CURRENTLY STRETCHES ACROSS SOUTH FLORIDA INTO THE
ATLANTIC WITH ANOTHER STRONG RIDGE OVER THE SOUTHERN PLAINS.
SANDWICHED IN BETWEEN THESE TWO HIGHS IS A WEAK TROUGH AND THIS HAS
CAUSED SOME DESTABILIZATION TO THE AIRMASS ACROSS SOUTH FLORIDA THIS
MORNING. THIS WILL CREATE A MORE ACTIVE AFTERNOON FOR THUNDERSTORMS
THAN YESTERDAY BUT THE STEERING FLOW WILL KEEP MOST ACTIVITY INLAND
AWAY FROM THE COASTS. HOWEVER, STEERING FLOW IS NEARLY PARALLEL TO
THE COASTS SO SOME CONVECTION WILL FIRE UP JUST INLAND FROM THE
COASTS BEFORE THE SEA BREEZES PUSH THE ACTIVITY WELL INLAND. MUCH
DRIER AIR ALOFT IS CURRENTLY LOCATED ACROSS THE CENTRAL BAHAMAS, AND
IN THE CIRCULATION AROUND THE BASE OF THE RIDGE WILL BEGIN TO MOVE
INTO SOUTH FLORIDA ON SATURDAY AND ESPECIALLY ON SUNDAY. THE GFS IS
MUCH FASTER WITH THE LEADING EDGE OF THE DRIER AIR WITH THE NAM NOT
SHOWING IT TO REACH THE SOUTHEAST COASTAL AREA UNTIL LATE SATURDAY
AFTERNOON. STILL, THE FORECAST SOUNDINGS ARE SHOWING PWAT LOWERING
TO AROUND 1.5 INCHES DURING THE COURSE OF THE DAY AND THIS WILL
LIMIT THE OVERALL COVERAGE OF THUNDERSTORMS. THE ATMOSPHERE WILL
REMAIN VERY UNSTABLE HOWEVER WITH PLENTIFUL LOW LEVEL MOISTURE SO
SCATTERED STORMS OVER THE INTERIOR WILL STILL BE ANTICIPATED. THE
STEERING FLOW WILL BE MORE EASTERLY BUT AT 5 MPH OR LESS SO SOME
STORMS COULD AGAIN FORM JUST INLAND FROM THE COASTS BEFORE PUSHING
TO THE INTERIOR AREAS. THE MODELS ARE IN GOOD AGREEMENT THAT THE
DRIEST AIR WILL ARRIVE BY SUNDAY WITH FORECAST SOUNDINGS SHOWING
PWAT DOWN TO LESS THAN 1.2 INCHES SO ACTIVITY WILL BE MUCH LESS. THE
500MB TEMPERATURES ARE ALSO DEPICTED TO WARM BACK TO AROUND -5 TO -
6C WHICH ALSO WILL ACT TO LIMIT THUNDERSTORM DEVELOPMENT.
LONG TERM (MONDAY-FRIDAY)...
A STRONG AND DEEP MID/UPPER LEVEL TROUGH WILL DEVELOP ACROSS THE
EASTERN U.S. NEXT WEEK WITH A COLD FRONTAL BOUNDARY ENTERING NORTH
FLORIDA BY TUESDAY OR WEDNESDAY. THIS SET UP WILL LIKELY DESTABILIZE
THE AIRMASS OVER SOUTH FLORIDA ONCE AGAIN ALTHOUGH NEITHER THE GFS
NOR ECMWF SHOW SIGNIFICANT COOLING ALOFT AT THIS TIME AND NEITHER
INCREASE MOISTURE SUBSTANTIALLY. SO IT REMAINS UNCERTAIN AT THIS
TIME JUST HOW MUCH INFLUENCE THIS SYSTEM WILL HAVE ON SOUTH FLORIDA
BUT THE STEERING FLOW WILL TURN MORE SOUTH TO SOUTHWEST WITH THE
INTERIOR AND EAST COAST HAVING THE BETTER CHANCES FOR THE
THUNDERSTORMS.
ON A SIDE NOTE, THERE IS A SAHARAN DUST LAYER (SAL) ACROSS THE
CARIBBEAN AND THE CENTRAL ATLANTIC. THE MODELS KEEP MOST OF THIS TO
OUR SOUTH AND EAST BUT ARE SHOWING A DIFFUSE PART OF IT REACHING
SOUTHEAST TIP OF THE PENINSULA LATE THIS WEEKEND OR EARLY NEXT WEEK.
NO MAJOR EFFECTS ARE EXPECTED ALTHOUGH IT COULD MAKE THE SKY APPEAR
HAZIER THAN NORMAL.
MARINE...
TRANQUIL MARINE CONDITIONS WILL CONTINUE WITH A LIGHT EAST TO
SOUTHEAST WIND LESS THAN 15 KNOTS AND SEAS OF 2 FEET OR LESS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 78 90 78 91 / 20 20 20 20
FORT LAUDERDALE 80 91 80 92 / 10 20 10 30
MIAMI 80 91 79 93 / 10 20 10 30
NAPLES 77 90 77 92 / 20 20 10 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
453 AM EDT SAT JUL 26 2014
.SYNOPSIS...
ISSUED AT 134 AM EDT SAT JUL 26 2014
PERIODIC CHANCES FOR SHOWERS AND THUNDERSTORMS WILL RETURN THIS
WEEKEND AS A FRONTAL BOUNDARY SETTLES INTO THE REGION. LOWS WILL
GENERALLY BE IN THE 60S...WITH HIGHS EXPECTED TO REACH THE 80S ON
SATURDAY AND SUNDAY. MUCH COOLER WEATHER WILL RETURN EARLY NEXT
WEEK AS AN UPPER TROUGH SETTLES IN.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 451 AM EDT SAT JUL 26 2014
NOSE OF LOW LEVEL JET FOCUS COINCIDENT WITH EASTERN PERIPHERY OF
STOUT EML BEGINNING TO DRIVE CONVECTIVE DEVELOPMENT UPSTREAM IN ARC
STRETCHING FROM EASTERN IA-NWRN IL-FAR WCNTL IN. VEERING JETLET AND
STEERING FLOW SUGGESTS MAJORITY OF SHRA TO TARGET ONLY FAR SWRN/SRN
CWA THIS AM. LACK OF APPRECIABLE LOW LEVEL MOISTURE WITH EASTERN
EXTENT SHOULD PRECLUDE ALL BUT PERHAPS AN ISOLD TSRA WITH EASTERN
EXTENT INTO CWA. SMALL CHC TSRA POPS IN DEFERENCE TO SHORT MODEL
CONSENSUS AFFORDED ACROSS ERN CWA THIS AFTN AS RIDGE OF GREATER
1000-850MB THETA-E/MOISTURE FLUX CONVERGENCE ASSERTS INTO NERN
IN/NWRN OH. DIFFERENTIAL HEATING ALONG DECAYING AM SHRA AND
STRATO/ALTOCU LAYERS AND PRESENCE OF DIFFUSE WARM FRONTAL LIMB LENDS
CREDENCE TO TREND OF OUTCOME/SOLUTIONS SEEN WITH 3KM HIGH-RES RAPID
REFRESH RUC IN THIS REGARD. WEAK LOW AMPLITUDE RIDGING SHOULD ALLOW
LOW END MENTION TO SUFFICE THROUGH TODAY. BY FAR THE GREATER
CONVECTIVE CONCERN LIES UPSTREAM AS EXTREME SERN SASK VORTEX DRIVES
SEWD INTO NRN MN EARLY TONIGHT WITH 60-70KT MID TROPOSPHERIC FLOW
ALONG SOUTHERN PERIPHERY OF WAVE. STRONG MID/UPPER LEVEL KINEMATICS
TO IMPINGE ON AREA OF SIGNIFICANT MOISTENING/HEATING BENEATH
RESIDUAL EML TO OFFER STRONG 3500-5000 J/KG SBCAPE BY 00 UTC SUN.
THIS LARGE INSTABILITY POOL PRESENTS ELONGATED E-W FROM SWRN CWA TO
MO/IA BORDER AMID 40-50 KTS DEEP LAYER BULK SHEAR. DECENT POTENTIAL
FOR MULTIPLE EPISODIC EVENING/EARLY NIGHT SUPERCELLS TO DEVELOP
UPSTREAM ACROSS CENTRAL/NCENTRAL ILLINOIS TO TRACK INTO SRN HALF OF
CWA AND TRANSITION TOWARD STRONG/SEVERE QUASI-LINEAR SEGMENTS
THROUGH SOUTHERN HALF OF CWA IN STRONG PARALLEL STORM MOTION
VECTORING. MDPI GT 1 AND DECENT /1000-1250 J/KG/ CAPE WITHIN
M10-M30C HAIL PRODUCTION ZONE WITH FAVORABLE WETBULB ZERO HEIGHTS IN
10.5-11.5 RANGE SUGGESTIVE OF MULTIPLE DAMAGING WIND EVENTS/ISOLATED
LARGE HAIL RISKS. DIFFICULTY IN SHARP DEMARCATION OF POPS WITH
EXTREMELY SHARP INSTABILITY GRADIENT WITH ONLY SLIGHT CHC MENTION
WARRANTED FAR NRN CWA RAMPING TO SIGNIFICANT/SEVERE LIKELY
POPS/SEVERE MENTION GENERALLY ALONG/S OF ROUTE 30 IN 00-09 UTC
TIMEFRAME. SOME CONCERN FOR POTENTIAL BACKBUILDING/TRAILING
STRATIFORM CONVECTION IN 06-12 UTC TIMEFRAME AS STORM MOTION VECTORS
BACK DUE WESTERLY...ALONG/PARALLEL TO TRAILING POOL OF EXTREME
1000-850MB MIXING RATIO GTE 16 G/KG THAT REACHES BACK INTO WEST
CENTRAL IL. WILL ADDRESS TERTIARY FLOODING POTENTIAL IN HWO IN
ADDITION TO DMG WIND/HAIL CONCERNS.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 451 AM EDT SAT JUL 26 2014
A WELL DEFINED UPPER LEVEL DISTURBANCE OVER SOUTHERN SASKATCHEWAN
PROVENCE EARLY THIS MORNING WILL MOVE SOUTHEAST DOWN THE BACKSIDE OF
THE UPPER LEVEL RIDGE. AS THIS SYSTEM MOVES SOUTHEAST TOWARD THE
WESTERN GREAT LAKES REGION...VERY UNSTABLE AIR WILL EXTEND INTO
NORTHERN INDIANA AND NORTHWEST OHIO EARLY SUNDAY MORNING. HIGH
ENERGY HELICITY INDEX VALUES UP TO 4.0 TO 5.0 M2/S2 REFLECT THE
POTENTIAL FOR SUPERCELL ACTIVITY OVER THE SOUTHERN THIRD OF THE
FORECAST AREA EARLY SUNDAY MORNING. SEVERE WEATHER CHANCES LOOK BEST
IN THE MORNING OVER FAR SOUTH AND SOUTHEAST AREAS. CONCERN FOR
MAINLY DAMAGING WINDS EARLY GIVEN A FAVORABLE WIND PROFILE
SIGNATURE. SEVERE WEATHER CHANCES SHOULD DIMINISH BY EARLY AFTERNOON
AS COOLER AIR SPREADS OVER THE AREA BEHIND THE FRONT. FOR THE REST
OF THE PERIOD...SOME LINGERING SHOWERS ARE POSSIBLE TONIGHT AND
MONDAY AS A POST FRONTAL TROF MOVES ACROSS THE AREA. KEPT THE REST
OF THE PERIOD DRY AS THE UPPER LEVEL TROF REMAINS OVER THE AREA. 500
MB ANALOGS SUPPORT TEMPERATURES BELOW NORMAL THIS UPCOMING WORK WEEK
WITH A PERSISTENT NEGATIVE HEIGHT ANOMALY SOUTH OF HUDSON BAY.
PREFER THE COOLER GFS/MEAN/MEX VALUES GIVEN COOL 850 MB TEMPERATURES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 130 AM EDT SAT JUL 26 2014
HAVE REMOVED VCSH AT KSBN IN LIGHT OF LACK OF SIGNIFICANT UPSTREAM
UPDRAFT DEVELOPMENT ALONG WITH GRADUAL VEERING OF 925-8H JETLET
OVERNIGHT. WHILE SOME ISOLD SHRA STILL POSSIBLE ALONG/AHEAD ARC
OF LOW LEVEL FRONTOGENETIC CONVERGENCE FROM IA/CNTL IL/SWRN
IN...VEERING OF JETLET TOWARD LOWER OHIO VALLEY BY DAYBREAK AND
NWRLY COMPONENT STEERING FLOW SUGGESTS GREATEST PROBABILITY TO
REMAIN WELL W/SW/S OF NRN INDIANA RESPECTIVE WITH TIME THROUGH
DAYBREAK. BETTER CHANCES FOR CONVECTIVE DEVELOPMENT APPEAR JUST
AFTER DARK AS KS FRONTAL WAVE LIFTS INTO CNTL IL AMID LARGE/EXTREME
3500-5000 J/KG SBCAPE POOL.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...MURPHY
SHORT TERM...MURPHY
LONG TERM...SKIPPER
AVIATION...MURPHY
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AREA FORECAST DISCUSSION
NWS DES MOINES IA
346 AM CDT SAT JUL 26 2014
.SHORT TERM /TODAY/...
ISSUED AT 345 AM CDT SAT JUL 26 2014
RATHER COMPLEX FORECAST FOR TODAY AS CONFIDENCE OF EVOLUTION OF MESO
SCALE ONLY MODEST AT THIS TIME...BUT COULD BE AN RATHER ACTIVE
AFTERNOON AND EVENING OVER THE SOUTH. AFTER EARLY MORNING PATCHY FOG
POTENTIAL FOR SEVERE WEATHER THIS AFTERNOON FOR ABOUT THE SOUTHERN
HALF OF THE FORECAST AREA. EARLY THIS MORNING A SHORT WAVE OVER THE
SOUTHERN PLAINS AT H850 IS DRIVING WARM AIR AND RATHER HIGH MOISTURE
INTO IOWA AND SURROUNDING STATES. A LARGE POOL OF 15C DEW POINTS
EXTENDS FROM EASTERN KS... COVERING ALL OF IOWA AND NORTHERN MO AS
WELL AS EASTERN MN AND WESTERN WI. CLOUDS HAVE BEEN DEVELOPING AT
MID LEVELS OVER SOUTHERN IOWA IN RESPONSE TO THIS MOISTURE AND A
WEAK SFC BOUNDARY/ZONE OF H850 30KT LLJ MOVING ACROSS THE AREA. SO
FAR THERE IS TOO MUCH CIN TO REALLY LET ANYTHING GO AT THIS TIME.
NORTHWEST OF US A PRONOUNCED H700 SHORTWAVE CURRENTLY IN WY/MT WILL
SHIFT EAST SOUTHEAST TODAY. AHEAD OF IT A WEAKER WAVE IS PRODUCING A
SMALL AREA OF CONVECTION OVER EASTERN SOUTH DAKOTA ALONG A RATHER
MINOR TROUGH AT H850 THAT EXTENDS FROM SUPERIOR/DULUTH BACK
SOUTHWESTWARD TO HURON AND RAPID CITY. IT IS EXPECTED THAT THIS AREA
OF CONVECTION WILL WEAKEN AND CONTINUE TO MOVE SOUTHEAST AND IMPACT
NORTHERN PORTIONS OF THE FORECAST AREA THIS MORNING PRIOR TO NOON.
THE WESTERN EDGE OF THE CONVECTION THOUGH...IS EXPECTED TO INTENSIFY
BY LATE MORNING IN RESPONSE TO THE APPROACHING STRONGER H700 WAVE
AND H500 WESTERLIES INCREASING TO 50KTS BY 00Z AND H300 WINDS
NEARING 70 TO 85KTS BY 00Z OVER IOWA.
THIS MORNING A WEAK SFC LOW OVER SOUTHWEST IOWA WILL DRIFT SOUTHEAST
INTO NORTHERN MO DURING THE AFTERNOON HOURS. A PRONOUNCED 2500 TO
3500 J/KG MLCAPE MAX WILL BE OVER THE SOUTHERN TWO TIER COUNTIES BY
18Z...WITH HEATING INCREASING INSTABILITY TO 3500 J/KG NEAR DES
MOINES TO 5500 J/KG JUST SOUTH OF THE IA/MO BORDER. HRRR MODEL
SUGGESTS THAT A SMALL CLUSTER OF STORMS SHOULD BE ONGOING IN
NORTHEAST/EAST NEBRASKA WHILE THE NMM/ARW SUGGEST THAT THE
CONVECTION OVER NEBRASKA WILL DISSIPATE AND REDEVLOP OVER FAR
SOUTHERN IA/MO. HOPWRF ALSO SHOWS EASTERN NEBRASKA CONVECTION
CONTINUING TO INTENSIFY WITH TIME THIS AFTERNOON MOVING ESE. THIS IS
SUPPORTED BY THE MEAN AND FORWARD PROPAGATING CORFIDI VECTORS...WITH
TRANSLATION ABOUT 30 TO 40 KTS. WITH THE WEAK BOUNDARY OVER THE
IOWA/MISSOURI BORDER BY 00Z...ANY CONVECTION THAT DEVELOPS TO OUR
WEST WILL RAPIDLY INTENSIFY INTO THE AXIS OF HIGH CAPE THIS
AFTERNOON. GIVEN THE VARIOUS SOLUTIONS...AM LEANING TOWARD
CONVECTION DEVELOPING IN NORTHEAST/EAST NEBRASKA AND STRENGTHENING
RAPIDLY THIS AFTERNOON AS IT INTERACTS WITH THE MOISTURE POOL IN AND
NEAR IOWA TO THE SOUTH. HAVE INCREASED POP ACROSS THIS AREA TO
REFLECT THAT SCENARIO. THE SOUTH IS OUTLOOKED FOR A SLIGHT
RISK...LOOKS VERY REASONABLE WITH THE POTENTIAL OF A STRENGTHENING
FORWARD PROPAGATING CONVECTIVE COMPLEX NEAR/JUST NORTH OF THE
BOUNDARY LATER TODAY THROUGH EITHER SOUTHERN IOWA OR NORTHERN
MISSOURI. THERE WILL BE A POTENTIAL FOR HIGHER IMPACT CONVECTIVE
WINDS IF THE SYSTEM GETS STRONG ENOUGH PRIOR TO MOVING SOUTH/EAST OF
THE AREA THIS EVENING. PRECIPITABLE WATER INCREASES TO OVER TWO
INCHES SOUTH OF INTERSTATE 80 THIS AFTERNOON WITH WARM CLOUD DEPTHS
OF 13 TO 14KFT TODAY AS WELL. IN ANY STRONGER STORMS THAT DEVELOP...
A QUICK 1 TO +2 INCHES IS VERY POSSIBLE DESPITE THE PROJECTED FAST
MOVEMENT OF THE STORMS. HIGHS WILL AGAIN BE WARM SOUTH IN THE UPPER
80S TO NEAR 90 WITH LOWER TO MID 80S ACROSS THE NORTH. WINDS WILL
NOT BE APPRECIABLE STRONG AND GENERALLY OUT OF THE NORTHEAST.
.LONG TERM /TONIGHT THROUGH FRIDAY/...
ISSUED AT 345 AM CDT SAT JUL 26 2014
NEARLY ALL OF THE CONCERNS IN THIS PERIOD WILL BE EARLY ON...THIS
EVENING. THE AIRMASS WILL BE THERMODYNAMICALLY PRIMED DURING PEAK
HEATING WITH THE GFS/NAM SUGGESTING MLCAPES 4K J/KG OR GREATER AND
LITTLE CINH. ONLY QUESTION WILL BE WHETHER A TRIGGER MECHANISM WILL
BE IN PLACE AND THAT SEEMS TO BE LESS AND LESS OF A CONCERN
JUDGING FROM CURRENT UPSTREAM CONDITIONS. RAP OBJECTIVE ANALYSIS
AND WATER VAPOR LOOP SHOW SEVERAL SHORT WAVES/PV ANOMALIES
TOPPING THE SWRN CONUS RIDGE AND EMBEDDED IN THE SEASONALLY FAST
PACIFIC NW TO NRN PLAINS UPPER FLOW. THIS KINEMATIC FORCING IS
CURRENTLY DRIVING SMALL WRN KS AND SD CONVECTIVE CLUSTERS IN
AREAS OF WEAK THERMODYNAMIC SUPPORT. THUS EXPECT REMNANTS OF THESE
FEATURES AND ASSOCIATED FORCING TO BE TRAVERSING SRN IA/NRN MO
DURING PEAK HEATING IN THE VICINITY OF CURRENT SURFACE
FRONT...NOTED ALONG SRN ONE/TWO TIERS OF IA COUNTIES PER 07Z
ANALYSIS. OPERATIONAL AND HI RES MODELS SUGGEST CONVERGENCE
ASSOCIATED WITH THIS BOUNDARY WILL BE INTO MO BY 00Z...BUT
EXISTING CONVECTION FROM EARLIER IN THE DAY MAY ALSO BE IN PLACE
JUST NORTH OF THE BOUNDARY AS WELL AS MENTIONED IN SHORT TERM
DISCUSSION. ALTHOUGH THE SHALLOW SHEAR IS WEAK...THE DEEP SHEAR
SHOULD BE IN THE 50KT RANGE SUGGESTING ANYTHING THAT DOES NEWLY DEVELOP
COULD BE SUPERCELLULAR INITIALLY. ALTHOUGH THE 0-1KM KINEMATICS
ARE WEAK...THE DEGREE OF DEEP AND 0-3KM INSTABILITY MAY KEEP A FEW
THERMODYNAMICALLY DOMINATE TORNADOES IN THE PICTURE AS WELL...IN
ADDITION TO THE WIND AND HAIL THREAT AS SYSTEM EVOLVES AND LIKELY
BECOMES MORE LINEAR. WHATEVER DOES OCCUR WILL EITHER MOVE OUT OF
OUR FORECAST AREA QUICKLY...OR STAY INTO NRN MO SO OUR WINDOW WILL
BE BRIEF WITH DRY CONDITIONS OVERNIGHT.
COOLER TEMPERATURES WILL THEN BE THE PRIMARY WEATHER STORY INTO
EARLY NEXT WEEK. THERE IS LITTLE IN THE WAY OF FORCING OR WARM
ADVECTION RIGHT ON THROUGH THE EXTENDED...AND EITHER UNIFORM NW
SURFACE FLOW OR LIGHT AND VARIABLE WINDS SHOULD LEAD TO MINIMAL LOW
LEVEL CONVERGENCE. STEEP LAPSE RATES NEAR THE CORE OF THE CURRENT
SASKATCHEWAN AND EVENTUALLY WRN GREAT LAKES UPPER LOW MAY DEVELOP
SOME SHOWERS NE DURING PEAK HEATING SUN...BUT OTHERWISE HAVE EITHER
A DRY FORECAST OR ONLY SLIGHTS FOR THE REMAINDER OF THE FORECAST.
TEMPS STILL LOOK BELOW NORMAL WITH HIGHS OFTEN IN THE 70S AND NO
BETTER THAN THE LOW 80S. LOWS SHOULD OFTEN BE IN THE 50S OR LOWER
60S. ALTHOUGH UPPER LEVEL WINDS WILL EVENTUALLY DIMINISH WITH SOME
HEIGHT RISES...THE OVERALL PATTERN /MORE POSITIVE PNA/ WILL
CHANGE LITTLE INTO NEXT WEEKEND WITH WRN CONUS RIDGE/ERN TROUGH.
&&
.AVIATION...26/06Z
ISSUED AT 1130 PM CDT FRI JUL 25 2014
CIGS ARE MESSY ACROSS TAF LOCATIONS WITH MVFR CIGS ACROSS THE NE AND
LOWER VFR CIGS ACROSS THE N AND HIGHER CLOUDS ACROSS THE SOUTH. A
SOUPY AIRMASS COMBINED WITH LIGHT WINDS WILL LIKELY PRODUCE SOME
LIGHT DRIZZLE AND FOG. AN UPPER LEVEL FEATURE WILL MOVE IN BETWEEN
09Z-12Z OR SO AND COULD PRODUCE THUNDERSTORMS ACROSS NORTHERN TAF
LOCATIONS BUT AT THIS POINT COVERAGE LOOKS LIKE IT MIGHT BE ISOLD.
ADDITIONAL THUNDER POSSIBLE ACROSS SOUTHERN TAF LOCATIONS...MAINLY
KOTM AS A STALLED FRONTAL BOUNDARY PROVIDES FOCUS FOR TSRA AFT 20Z
OR SO.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...REV
LONG TERM...SMALL
AVIATION...FAB
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1130 PM CDT FRI JUL 25 2014
.UPDATE...
ISSUED AT 1130 PM FRI JUL 25 2014
COMPLEX SCENARIO TONIGHT AS A WEAK FRONTAL BOUNDARY PUSHES INTO IA.
COOLER AIR ALOFT COULD WEAKEN THE CAP AS A SHORTWAVE PUSHES INTO
WRN/NW IA BETWEEN 09Z-12Z. SMALL CLUSTERS OF STORM ALREADY ONGOING
IN CEN/ERN NEB AND SDKTA MAY MERGE AND DRIFT INTO NRN IA WELL INTO
THE OVERNIGHT. THE NAM SUGGESTS THIS BUT IS PRETTY MEAGER ON QPF.
THE HOPWRF AND HRRR ALL SUGGEST SOME SORT OF MCS PUSHING INTO NW/NRN
IA THOUGH THAT LOOKS A LITTLE OVERDONE. STILL...WITH THE 4 INCH
RAINFALLS IN LOCATIONS FROM LAST NIGHT AND THE SOUPY DEWPOINTS STILL
IN PLACE...HEAVY RAINFALL CANNOT BE RULED OUT. FOR THE UPDATE I
WILL LIKELY EXPAND TSRA INTO NRN IA TOWARDS 12Z. ANOTHER AREA OF
CONCERN IS FAR SRN/SE IA WHERE A WARM FRONT IS RESIDING AND PRETTY
STRONG WARM ADVECTION WILL BE FEEDING INTO A LLJ OF 30KTS.
ADDITIONAL STORMS MAY DEVELOP THERE AS WELL THOUGH ODDS GO WITH THE
INCOMING SHORTWAVE ACROSS THE NORTH AS THE BETTER LOCATION FOR
STORMS. THERE WILL ALSO LIKELY BE SOME FOG TO DEAL WITH ACROSS THE
EASTERN THIRD TO HALF OF IOWA OVERNIGHT.
&&
.SYNOPSIS...
ISSUED AT 320 PM CDT FRI JUL 25 2014
LOW PRESSURE OVER SERN NEBRASKA WILL DRIFT EAST AS FRONTAL
BOUNDARY EXTENDING EAST FORM THE LOW BEGINS TO SINK SOUTH TONIGHT.
SECONDARY LOW WILL MOVE UP THE FRONT FROM THE SOUTHWEST ON
SATURDAY. HIGH PRESSURE WILL BUILD INTO THE REGION AND DOMINATE
THE WEATHER INTO NEXT WEEK.
&&
.SHORT TERM /TONIGHT/...
ISSUED AT 320 PM CDT FRI JUL 25 2014
WEAK LOW PRESSURE SYSTEM IN SOUTHERN NE WITH WEAK BOUNDARY INTO
SOUTHERN IOWA DID NOT ADVANCE AS FAR NORTH TODAY AS
ANTICIPATED...WITH CLOUDS FROM OVERNIGHT CONVECTION ALSO LINGERING
ACROSS THE AREA. THIS HELPED TO KEEP TEMPERATURES MUCH COOLER THAN
ANTICIPATED ACROSS CENTRAL AND SOUTHERN CWA. THEREFORE...WILL DROP
HEAT ADVISORY FOR REMAINING PORTION...LOCATIONS IN THE OLD ADVISORY
AREA MAY SEE HEAT INDEX VALUES NEAR 100 THROUGH THE REMAINDER OF THE
AFTERNOON...BELOW CRITERIA. IN ADDITION...HAVE DROPPED OVERNIGHT LOW
TEMPERATURES A FEW DEGREES AS WELL.
LOW WILL PUSH EASTWARD OVERNIGHT...THOUGH WILL REMAIN CAPPED ACROSS
THE CWA AND HAVE KEPT DRY FORECAST. SECONDARY LOW BEGINS TO
INFLUENCE AREA NEAR 12Z...THOUGH MODELS KEEP SYSTEM FURTHER
WEST...AND HAVE CUT POPS FOR END OF PERIOD.
.LONG TERM /SATURDAY THROUGH FRIDAY/...
ISSUED AT 320 PM CDT FRI JUL 25 2014
FRONTAL BOUNDARY WILL REMAIN SOUTH OF IA THROUGH SATURDAY. LOW
PRESSURE WILL MOVE NEWD ALONG THE BOUNDARY ON SATURDAY WITH LOW
CHANCES FOR THUNDERSTORMS ACROSS THE SOUTH. GIVEN THE LITTLE NWD
PROGRESS OF THE WARM FRONT...DO NOT SEE A STRONG CHANCE OF
VIGOROUS THUNDERSTORM DEVELOPMENT AS FAR NORTH IA IA WILL KEEP IN
CHANCES ACROSS THE SOUTH...LEANING TOWARD THE FURTHER SOUTH
SOLUTIONS OF THE OF NAM.
HIGH PRESSURE WILL EXERT ITS STRENGTH INTO THE CENTRAL U.S. SAT
NIGHT INTO NEXT WEEK. THIS WILL KEEP TEMPS AT LEAST 5 TO 10
DEGREES BELOW NORMAL FOR A GOOD PART OF THE WEEK. THERE WILL BE
LITTLE CHANCE FOR ANY SIGNIFICANT RAINFALL.
&&
.AVIATION...26/06Z
ISSUED AT 1130 PM CDT FRI JUL 25 2014
CIGS ARE MESSY ACROSS TAF LOCATIONS WITH MVFR CIGS ACROSS THE NE AND
LOWER VFR CIGS ACROSS THE N AND HIGHER CLOUDS ACROSS THE SOUTH. A
SOUPY AIRMASS COMBINED WITH LIGHT WINDS WILL LIKELY PRODUCE SOME
LIGHT DRIZZLE AND FOG. AN UPPER LEVEL FEATURE WILL MOVE IN BETWEEN
09Z-12Z OR SO AND COULD PRODUCE THUNDERSTORMS ACROSS NORTHERN TAF
LOCATIONS BUT AT THIS POINT COVERAGE LOOKS LIKE IT MIGHT BE ISOLD.
ADDITIONAL THUNDER POSSIBLE ACROSS SOUTHERN TAF LOCATIONS...MAINLY
KOTM AS A STALLED FRONTAL BOUNDARY PROVIDES FOCUS FOR TSRA AFT 20Z
OR SO.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$ UPDATE...FAB
SYNOPSIS...MS JUL 14
SHORT TERM...AWB
LONG TERM...MS JUL 14
AVIATION...FAB
AREA FORECAST DISCUSSION
NWS GOODLAND KS
221 AM MDT SAT JUL 26 2014
.UPDATE...
ISSUED AT 846 PM MDT FRI JUL 25 2014
RADAR TRENDS OVER THE LAST HOUR HAVE SHOWN AN INCREASE IN
INTENSITY OF THE LINE OF STORMS MOVING EASTWARD. LOOKING AT RUC
SOUNDINGS FOR TRIBUNE THE BEST ELEVATED INSTABILITY IS ABOVE
700MB...WITH A BULLS EYE OF NEAR 1500J/KG OF CAPE JUST WEST OF THE
KS/CO LINE IN EASTERN CHEYENNE COUNTY. THIS INSTABILITY DRIFTS
SOUTH-SOUTHEAST OVER THE NEXT COUPLE OF HOURS BEFORE DISSIPATING.
MEANWHILE THE ELEVATED CAPE WILL LINGER UNTIL AROUND MIDNIGHT THEN
END AS THE ENVIRONMENT STABILIZES.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY)
ISSUED AT 112 PM MDT FRI JUL 25 2014
EARLY AFTERNOON WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW BROAD
RIDGE STILL IN PLACE FROM THE DESERT SW ACROSS THE SOUTHERN
PLAINS...WITH A PLUME OF MID-UPPER LEVEL MOISTURE AND WEAK VORTICITY
ROTATING AROUND THE NORTHERN PERIPHERY OF THIS RIDGE ACROSS THE
CENTRAL ROCKIES INTO THE HIGH PLAINS. A CLOSED LOW IS MOVING ACROSS
SOUTHERN CANADA WITH SOME WEAK REFLECTION OF THIS EXTENDING FURTHER
SOUTH INTO THE NORTHERN PLAINS. AT THE SURFACE A WEAK COLD FRONT HAS
STALLED OVER THE SOUTHERN PART OF OUR CWA...WITH FAVORABLE JULY
SOLAR ANGLE SUPPORTING GOOD RADIATIONAL WARMING THIS AFTERNOON AS
HIGHS HAVE STILL REACHED THE MID TO UPPER 90S OVER MUCH OF THE CWA
(A LITTLE COOLER TOWARDS THE NW).
STALLED FRONT IN THE SOUTH COMBINED WITH ELEVATED TERRAIN IN
COLORADO SHOULD HELP INITIATE THUNDERSTORMS (WHICH HAVE ALREADY
DEVELOPED ALONG FRONT RANGE). HIGH LCL/LFC OVER OUR CWA SHOULD KEEP
THUNDERSTORM ACTIVITY ELEVATED AND WITH INCREASING INSTABILITY AND
DCAPE WOULD SUPPORT POTENTIAL FOR DOWNBURSTS. IF UPDRAFTS ARE STRONG
ENOUGH...MAYBE LARGE HAIL WOULD BE POSSIBLE THIS
AFTERNOON/EVENING...HOWEVER WITH VERY WARM LOW-MID LEVELS ABOVE
SHALLOW FRONTAL INVERSION CONDITIONS ARE MORE IN LINE WITH A WIND
THREAT. GUIDANCE CONTINUES TO SHOW BETTER COVERAGE OVER
CWA...HOWEVER DESPITE GOOD SURFACE-BL MOISTURE ALONG FRONTAL ZONE
AIR MASS ITSELF IS FAIRLY DRY AND COVERAGE IS A QUESTION. BEST
FORCING WOULD ACTUALLY BE LATER IN THE EVENING AS SHORTWAVE (ALONG
WITH POSSIBLE OUTFLOW FROM POSSIBLE MCS IN THE NORTH) MOVES INTO THE
CWA. AT THIS POINT I WAS COMFORTABLE KEEPING COVERAGE ISOLATED AND
DELAYED EXIT UNTIL AFTER 06Z. WILL NEED TO MONITOR TRENDS AS WESTERN
LOCATIONS COULD SEE SLIGHTLY BETTER COVERAGE BEFORE SUNSET.
DEEPENING ON EVOLUTION OF OUTFLOW (AS INDICATED BY NAM) OR WEAK
FRONTAL PASSAGE SATURDAY TEMPS COULD BE TRICKY ONCE AGAIN AS HEIGHTS
AND PATTERN ALOFT WOULD GENERALLY SUPPORT GOOD DAYTIME HEATING AND A
RECOVERY OF THE AIR MASS IN PLACE. I KEPT TEMPS SIMILAR TO TODAY
WITH ABOVE NORMAL VALUES IN THE 90S (AROUND 100F IN THE EAST). HIGH
BASED THUNDERSTORMS MAY DEVELOP AGAIN SATURDAY AFTERNOON ALONG
FRONTAL ZONE IN THE SOUTH...HOWEVER CONFIDENCE IS LOW ON EARLIER
INITIATION OVER OUR CWA...WITH FLOW MORE SUPPORTIVE OF UPSTREAM
DEVELOPMENT IN COLORADO.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 221 AM MDT SAT JUL 26 2014
HIGH PRESSURE AT 500 AND 700 MB WILL BE PRESENT OVER THE TRI STATE
AREA IN THE LONG TERM PERIOD WITH MAIN JET FLOW WELL TO THE NORTH OF
THE REGION. DESPITE THE LACK OF FORCING THAT WILL BE PRESENT
ALOFT...PLENTY OF MOISTURE WILL BE PRESENT WITH PRECIPITABLE WATER
AMOUNTS FROM THE GFS BETWEEN 1.25 AND 1.6 INCHES FOR THE DURATION OF
THE LONG TERM PERIOD. THE ECMWF ALSO HAS BETWEEN 1.25 AND 1.5 INCHES
OF PRECIPITABLE WATER FOR TUESDAY AND WEDNESDAY...AND THEN BRINGS IN
MORE DRY AIR ALOFT FOR LATER IN THE WEEK. THEREFORE...THE
POTENTIAL FOR SOME HEAVY RAINFALL WILL EXIST AREA WIDE.
A LOW PRESSURE SYSTEM DEVELOPING IN THE SOUTHERN PLAINS IN
COMBINATION WITH SOME SURFACE CONFLUENCE IN EASTERN COLORADO WILL
BRING CHANCES FOR THUNDERSTORMS TUESDAY THROUGH THURSDAY. THE
POTENTIAL FOR DRY AIR MOVING IN ALOFT WILL DECREASE CHANCES FOR
THUNDERSTORMS ON FRIDAY...HOWEVER SURFACE THETA E VALUES BETWEEN 330
AND 350 K ARE STILL PLENTY TO SUPPORT SOME STORMS THAT MAY DEVELOP.
INSTABILITY IS NOT TOO IMPRESSIVE WITH CAPE VALUES BELOW 1000 J/KG
FOR BOTH THE GFS AND ECMWF...BUT IS STILL SUFFICIENT ENOUGH TO
SUPPORT SOME CONVECTIVE DEVELOPMENT.
NORTHWEST FLOW ALOFT WILL KEEP CONDITIONS AT THE SURFACE A BIT
COOLER THAN AVERAGE DURING THIS PERIOD...WITH HIGH TEMPERATURES IN
THE LOW TO MID 80S ACROSS THE AREA. LOW TEMPERATURES SHOULD BE RIGHT
ABOUT NORMAL IN THE LOWER 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1140 PM MDT FRI JUL 25 2014
VFR CONDITIONS FORECAST FOR THE 6Z TAFS. AREA OF THUNDERSTORMS
SHOULD CONTINUE TO MOVE EASTERLY AND REMAIN SOUTH OF THE KMCK
SITE. AM THINKING THERE COULD BE A THREAT FOR FOG...ESPECIALLY
WHERE RAINFALL HAS OCCURRED. HOWEVER WILL KEEP A MENTION OF FOG
OUT OF THE KGLD TAF FOR NOW DUE TO LOWER DEW POINTS MOVING IN
THROUGH THE REST OF THE NIGHT. OTHERWISE A COLD FRONT WILL MOVE
THROUGH MID MORNING WITH WINDS BECOMING BREEZY BEHIND IT. DURING
THE AFTERNOON AN UPPER LEVEL SHORT WAVE TROUGH MOVES ACROSS THE
AREA SOUTH OF KGLD WHICH MAY SPARK A FEW STORMS OFF. THIS ACTIVITY
SHOULD REMAIN SOUTH OF THE SITE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...MK
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1148 PM MDT FRI JUL 25 2014
.UPDATE...
ISSUED AT 846 PM MDT FRI JUL 25 2014
RADAR TRENDS OVER THE LAST HOUR HAVE SHOWN AN INCREASE IN
INTENSITY OF THE LINE OF STORMS MOVING EASTWARD. LOOKING AT RUC
SOUNDINGS FOR TRIBUNE THE BEST ELEVATED INSTABILITY IS ABOVE
700MB...WITH A BULLS EYE OF NEAR 1500J/KG OF CAPE JUST WEST OF THE
KS/CO LINE IN EASTERN CHEYENNE COUNTY. THIS INSTABILITY DRIFTS
SOUTH-SOUTHEAST OVER THE NEXT COUPLE OF HOURS BEFORE DISSIPATING.
MEANWHILE THE ELEVATED CAPE WILL LINGER UNTIL AROUND MIDNIGHT THEN
END AS THE ENVIRONMENT STABILIZES.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY)
ISSUED AT 112 PM MDT FRI JUL 25 2014
EARLY AFTERNOON WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW BROAD
RIDGE STILL IN PLACE FROM THE DESERT SW ACROSS THE SOUTHERN
PLAINS...WITH A PLUME OF MID-UPPER LEVEL MOISTURE AND WEAK VORTICITY
ROTATING AROUND THE NORTHERN PERIPHERY OF THIS RIDGE ACROSS THE
CENTRAL ROCKIES INTO THE HIGH PLAINS. A CLOSED LOW IS MOVING ACROSS
SOUTHERN CANADA WITH SOME WEAK REFLECTION OF THIS EXTENDING FURTHER
SOUTH INTO THE NORTHERN PLAINS. AT THE SURFACE A WEAK COLD FRONT HAS
STALLED OVER THE SOUTHERN PART OF OUR CWA...WITH FAVORABLE JULY
SOLAR ANGLE SUPPORTING GOOD RADIATIONAL WARMING THIS AFTERNOON AS
HIGHS HAVE STILL REACHED THE MID TO UPPER 90S OVER MUCH OF THE CWA
(A LITTLE COOLER TOWARDS THE NW).
STALLED FRONT IN THE SOUTH COMBINED WITH ELEVATED TERRAIN IN
COLORADO SHOULD HELP INITIATE THUNDERSTORMS (WHICH HAVE ALREADY
DEVELOPED ALONG FRONT RANGE). HIGH LCL/LFC OVER OUR CWA SHOULD KEEP
THUNDERSTORM ACTIVITY ELEVATED AND WITH INCREASING INSTABILITY AND
DCAPE WOULD SUPPORT POTENTIAL FOR DOWNBURSTS. IF UPDRAFTS ARE STRONG
ENOUGH...MAYBE LARGE HAIL WOULD BE POSSIBLE THIS
AFTERNOON/EVENING...HOWEVER WITH VERY WARM LOW-MID LEVELS ABOVE
SHALLOW FRONTAL INVERSION CONDITIONS ARE MORE IN LINE WITH A WIND
THREAT. GUIDANCE CONTINUES TO SHOW BETTER COVERAGE OVER
CWA...HOWEVER DESPITE GOOD SURFACE-BL MOISTURE ALONG FRONTAL ZONE
AIR MASS ITSELF IS FAIRLY DRY AND COVERAGE IS A QUESTION. BEST
FORCING WOULD ACTUALLY BE LATER IN THE EVENING AS SHORTWAVE (ALONG
WITH POSSIBLE OUTFLOW FROM POSSIBLE MCS IN THE NORTH) MOVES INTO THE
CWA. AT THIS POINT I WAS COMFORTABLE KEEPING COVERAGE ISOLATED AND
DELAYED EXIT UNTIL AFTER 06Z. WILL NEED TO MONITOR TRENDS AS WESTERN
LOCATIONS COULD SEE SLIGHTLY BETTER COVERAGE BEFORE SUNSET.
DEEPENING ON EVOLUTION OF OUTFLOW (AS INDICATED BY NAM) OR WEAK
FRONTAL PASSAGE SATURDAY TEMPS COULD BE TRICKY ONCE AGAIN AS HEIGHTS
AND PATTERN ALOFT WOULD GENERALLY SUPPORT GOOD DAYTIME HEATING AND A
RECOVERY OF THE AIR MASS IN PLACE. I KEPT TEMPS SIMILAR TO TODAY
WITH ABOVE NORMAL VALUES IN THE 90S (AROUND 100F IN THE EAST). HIGH
BASED THUNDERSTORMS MAY DEVELOP AGAIN SATURDAY AFTERNOON ALONG
FRONTAL ZONE IN THE SOUTH...HOWEVER CONFIDENCE IS LOW ON EARLIER
INITIATION OVER OUR CWA...WITH FLOW MORE SUPPORTIVE OF UPSTREAM
DEVELOPMENT IN COLORADO.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 220 PM MDT FRI JUL 25 2014
UPPER FLOW TRANSITIONS FROM ZONAL TO NORTHWESTERLY IN THE SUN-MON
TIME FRAME...WHICH THEN CONTINUES THROUGH THE REST OF THE WEEK.
AT THE SURFACE...A REINFORCING SHOT OF COOLER AIR DROPS DOWN SATURDAY
NIGHT WHICH PUSHES THE SURFACE FRONT WELL SOUTH OF THE FORECAST
AREA. AS A RESULT...MUCH OF THE PRECIPITATION POTENTIAL EARLY ON
WILL BE SOUTH AND WEST OF THE CWA. THE BEST WINDOW FOR THUNDERSTORMS
IN THE EXTENDED PERIOD WILL BE TUE NIGHT-WED NIGHT WHEN THE EC/GFS
BOTH GENERATE AN EXTENSIVE AREA OF PRECIPITATION WHICH MOVES
SOUTHEAST ACROSS THE REGION AS A SHORT WAVE TROUGH DROPS THROUGH
THE FLOW.
THE PRESENCE OF A CANADIAN AIR MASS WHICH DOMINATES THE ENTIRE WEEK
WILL PROVIDE RELIEF FROM THE RECENT STRETCH OF HOT WEATHER. 850 MB
TEMPERATURES ARE FORECAST TO REMAIN IN THE 22-25C RANGE THROUGH
NEXT WEEKEND...WHICH TRANSLATES TO LOW-MID 80S FOR HIGHS. THE
COOLEST DAY WILL BE WEDNESDAY GIVEN THE LIKELY PRESENCE OF CLOUDS
AND SCATTERED SHOWERS AND THUNDERSTORMS. DEPENDING ON CLOUD COVER
THERE IS POTENTIAL FOR SOME AREAS TO REMAIN IN THE UPPER 70S WED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1140 PM MDT FRI JUL 25 2014
VFR CONDITIONS FORECAST FOR THE 6Z TAFS. AREA OF THUNDERSTORMS
SHOULD CONTINUE TO MOVE EASTERLY AND REMAIN SOUTH OF THE KMCK
SITE. AM THINKING THERE COULD BE A THREAT FOR FOG...ESPECIALLY
WHERE RAINFALL HAS OCCURRED. HOWEVER WILL KEEP A MENTION OF FOG
OUT OF THE KGLD TAF FOR NOW DUE TO LOWER DEW POINTS MOVING IN
THROUGH THE REST OF THE NIGHT. OTHERWISE A COLD FRONT WILL MOVE
THROUGH MID MORNING WITH WINDS BECOMING BREEZY BEHIND IT. DURING
THE AFTERNOON AN UPPER LEVEL SHORT WAVE TROUGH MOVES ACROSS THE
AREA SOUTH OF KGLD WHICH MAY SPARK A FEW STORMS OFF. THIS ACTIVITY
SHOULD REMAIN SOUTH OF THE SITE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...DLF
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
120 AM EDT SAT JUL 26 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 343 PM EDT FRI JUL 25 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A WNW FLOW ALF
OVER THE UPR LKS BTWN DEEP CLOSED LO OVER NRN QUEBEC AND SHRTWV RDG
AXIS EXTENDING NNEWD INTO MN/NW ONTARIO FM CENTER OF HIER HGTS OVER
THE SRN ROCKIES. ALTHOUGH SLOW INFLUX OF MOISTER AIR IN THE GENERAL
SW FLOW BTWN SFC/H85 HI OVER THE MID ATLANTIC STATES AND LOWER MSLP
IN THE NRN PLAINS ASSOCIATED WITH A DEEP CLOSED LO IN SRN
SASKATCHEWAN THAT IS RIDING OVER THE RDG CENTERED IN THE SRN ROCKIES
HAS ALLOWED FOR A GOOD DEAL OF CLDS/A FEW SHOWERS OVER MAINLY THE W
HALF OF THE CWA TDAY...MAIN FOCUS FOR HEAVIER PCPN HAS BEEN WELL TO
THE SW CLOSER TO SHARP H85 WARM FNT STRETCHING FM THE DAKOTAS INTO
THE MID MS RIVER VALLEY. HI STABILITY SHOWN ON THE 12Z INL RAOB AND
ESPECIALLY THE GRB RAOB...WHICH DEPICTS A SHARP INVRN ARND H75...HAS
TENDED TO LIMIT THE INTENSITY AND COVERAGE OF THE SHOWERS THAT HAVE
IMPACTED UPR MI. OVER THE ERN CWA...VERY DRY/STABLE AIRMASS SHOWN ON
THE 12Z APX RAOB HAS ALLOWED FOR MORE SUNSHINE. BUT TO THE W...MORE
SHOWERS ARE PRESENT IN NE MN/WRN LK SUP IN AREA OF HIER H85 THETA E
ADVCTN IN ADVANCE OF A WEAK SHRTWV MOVING E ALONG THE CNDN BORDER
ARND CLOSED LO IN SASKATCHEWAN. BUT EWD PUSH OF DRIER AIR IN THE NRN
PLAINS IS TENDING TO LIMIT THE OVERALL COVERAGE OF THESE SHOWERS AS
WELL.
MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE PCPN CHCS ASSOCIATED
WITH SHRTWV NOW MOVING ALONG THE CNDN BORDER.
LATE TDAY/TNGT...EXPECT AREA OF SHOWERS NOW IN NE MN AND A FEW
TS...THE POTENTIAL OF WHICH WL BE LIMITED BY PERSISTENT HIER MID LVL
STABILITY DEPICTED BEST ON THE GFS FCST SDNGS...TO SPREAD W-E INTO
UPR MI WITH AREA OF POSITIVE H85 THETA E ADVCTN THAT WL LIFT PWAT UP
TO ARND 1.5 INCHES/AXIS OF SOME H85-5 QVECTOR CNVGC IN ADVANCE OF
SHRTWV NOW TRACKING E ALONG THE CNDN BORDER. BUT ARRIVAL OF DRY AIR
NOW IN THE NRN PLAINS WL TEND TO DIMINISH THE POPS LATER EVEN THOUGH
THERE ARE HINTS A 2ND SHRTWV MIGHT FOLLOW INTO THE UPR LKS. FCST
LARGE SCALE QVECTOR DVGC OVER THE W LATE INDICATES THE DRYING WL
OVERCOME ANY PVA ASSOCIATED WITH THIS TRAILING SHRTWV. GOING FCST
POPS ARE IN PRETTY GOOD SHAPE AND NEED ONLY SMALL ADJUSTMENTS.
DESPITE THE MID LVL DRYING LATE...DVLPG LO CLDS WL LIMIT THE DIURNAL
TEMP FALL.
SAT...ANY LINGERING MRNG SHOWERS OVER MAINLY THE NE CWA WL END WITH
ARRIVAL OF DRIER AIR ALF THAT WL DEPRESS PWAT TO 0.75-1.0 INCH/DNVA
AND DEEP LYR QVECTOR DVGC AHEAD OF SHRTWV RDG TRAILING THE DEPARTING
2ND SHRTWV. WITH MRNG LO CLDS GIVING WAY TO MORE SUNSHINE AND FCST
H85 TEMPS AS HI AS 17-18C OVER THE W BY 00Z SUN...EXPECT MAX TEMPS
TO RISE INTO THE 80S AWAY FM THE MODERATING INFLUENCE OF THE GREAT
LKS. GIVEN THE MID LVL DRYING/POTENTIAL FOR DEEP MIXING AND NEAR
ADIABATIC LLVL LAPSE RATES...PREFER THE HIER END OF GUIDANCE FOR MAX
TEMPS...AT LEAST OVER THE INTERIOR W HALF. SOME OF THE HIER RES
MODELS...MAINLY THE 12Z NAM AND REGIONAL CNDN MODEL...DO INDICATE
THIS DAYTIME HEATING WL TRIGGER SOME SHOWERS/TS OVER THE ERN CWA IN
THE AFTN WITH CONVERGING LK BREEZES OFF LKS SUP/MI UNDER SOMEHWAT
LOWER HGTS. THE MAIN LIMITING FACTOR FOR THE DLPMNT OF THESE LK
BREEZE SHOWERS/TS WL BE THE DRYING ALF THAT IS FCST TO MIX TO THE
SFC WITH THE DAYTIME HEATING. IN FACT...DEEP MIXING ON THE GFS/NAM
FCST SDNGS HINT SFC DEWPTS OVER THE INTERIOR W HALF COULD MIX OUT AS
LO AS 45-50 LATE IN THE DAY...WITH KINX DROPPING TO 15-20. THE NAM
FCST SDNG FOR NEWBERRY AT 18Z SHOWS SBCAPE ARND 2K G/KG FOR SFC T/TD
OF 75/65. PREFER THE MORE CONSERVATIVE GFS FCST FOR SFC T/TD OF
75/60 AND SBCAPE CLOSE TO 700 J/KG. DESPITE THE LIMITATION OF THE
LARGE SCALE DRYING...WL MAINTAIN SOME LO CHC POPS OVER THE ERN CWA
TO ACCOUNT FOR THE LK BREEZE CNVGC.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 407 PM EDT FRI JUL 25 2014
COOL SUMMER PATTERN PERSISTS AS LARGE SCALE TROUGHING IS FORECAST TO
CONTINUE THROUGH DAYS 7-10. TEMPERATURES REMAIN BELOW NORMAL WITH
THE COOLEST DAYS EXPECTED MONDAY AND TUESDAY AS CORE OF UPPER LOW
AND COLD AIR MOVES ACROSS GREAT LAKES. MAX TEMPS BOTH DAYS LIKELY
WILL END UP AT LEAST 10 DEGREES BELOW NORMAL. NORMAL HIGHS THIS TIME
OF YEAR ARE IN THE MID 70S TO LOW 80S. MIN TEMPS WILL BE 5 TO 10
DEGREES BELOW NORMAL. NORMAL MIN TEMPS ARE IN THE LOW TO MID 50S.
OVERALL THIS PATTERN LOOKS DRY THROUGH THE NEXT COUPLE WEEKS PER THE
MEDIUM RANGE MODELS AND LATEST CPC OUTLOOKS.
BEST SHOT OF RAIN IS LATER SATURDAY NIGHT THROUGH SUNDAY AS UPPER
LOW AND STRONGER SHORTWAVE CURRENTLY OVER SOUTHERN SASKATCHEWAN
MOVES ACROSS WITH ASSOCIATED DEEP LAYER Q-VECTOR CONVERGENCE.
PASSAGE OF SHORTWAVE OCCURS AS THE INITIAL STRONG SFC-H85 COLD FRONT
IS CROSSING THE UPPER GREAT LAKES. MAIN ISSUE IS HOW FAST WILL THE
RAIN ARRIVE SATURDAY NIGHT AND ALSO IF THERE IS ANY POTENTIAL FOR
TSRA. SI/S BARELY BUMP BLO ZERO AND THAT IS FOCUSED ALONG THE WI
BORDER. HIGHEST POPS EXPECTED JUST TO NORTH OF UPPER LOW/SHORTWAVE
TRACK...MAINLY 09Z-21Z SUNDAY. TSRA CHANCES ARE THERE...BUT ARE
LIMITED TO A CHANCE AT BEST. UNLESS THE STORMS FORM EARLIER SATURDAY
EVENING WHEN DEEP SHEAR IS 30-40 KTS AND MLCAPE IS OVER 1000 J/KG...
DO NOT EXPECT ANY SEVERE STORMS SATURDAY NIGHT. INTO SUNDAY IT IS
POSSIBLE THAT IF THE SYSTEM SLOWS THERE WOULD BE INCREASED POTENTIAL
FOR SFC BASED TSRA SUNDAY AFTN. ATTM THOUGH LI/S BLO ZERO ARE
FORECAST TO STAY OVER WI AS STABLE COOL RAINY NORTH FLOW SHUNTS THE
GREATER INSTABILITY TO THE SOUTH. LOWERED TEMPS MORE ALONG LK
SUPERIOR ON SUNDAY...WITH UPR 50S TO AROUND 60 DEGREES. POINTS
FARTHER INLAND OVER SOUTHERN U.P. MAY BE ABLE TO REACH 70 DEGREES AT
LEAST BRIEFLY BEFORE CLOUDS THICKEN AND WIDESPREAD SHOWERS BEGIN.
SHOULD NOTE THAT THE STRONGER NORTH WINDS AND HIGHER WAVES WILL
INCREASE SWIM RISK FOR BEACHES OF LK SUPERIOR MQT TO GRAND MARAIS
SUNDAY INTO MONDAY. IF THE AIR TEMPS REMAIN IN THE UPPER 50S OR
HIGHER...WOULD NEED A BEACH HAZARD STATEMENT TO HIGHLIGHT THE RISK
EITHER FOR SUNDAY OR MONDAY OR POSSIBLY BOTH DAYS. ULTIMATELY WILL
DEPEND ON THE EXPECTED WEATHER FOR THE DAY.
BEYOND SUNDAY...UPPER TROUGH IN THE VCNTY COUPLED WITH INDIVIDUAL
SHORTWAVES AND AREAS OF DEEPER MOISTURE DROPPING ACROSS THE AREA
WILL COMBINE WITH DAYTIME HEATING/INSOLATION TO PRODUCE ISOLD-SCTD
SHOWERS...MAINLY DURING AFTN AND EVENING HOURS OF TUESDAY AND
WEDNESDAY. GRADUAL RISING HEIGHTS RESULT IN LESS CYCLONIC LOW-LEVEL
FLOW BY THURSDAY AND THERE IS ALSO LESS DEEP MOISTURE BY THAT POINT.
EXPECT THE CHANCES OF DIURNAL SHOWERS TO DIMINISH BY LATE THIS WEEK
AS TEMPS BEGIN TO WARM UP AGAIN. JUST ENOUGH MLCAPE DURING THE AFTN
FAR INLAND TO PUT KEEP SMALL TSRA CHANCES AS WELL WITH THE SHRA. MEAN
WINDS FM NORTH TO SOUTH RESULT IN GREATEST CHANCES FOR RAIN MOST DAYS
FARTHEST INLAND FROM THE MODERATION/STABILIZING INFLUENCE OF LK
SUPERIOR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 120 AM EDT SAT JUL 26 2014
A FEW SHOWERS...MAINLY SPRINKLES...CONTINUE TO DRIFT ACROSS UPPER
MICHIGAN EARLY THIS MORNING. SATELLITE IMAGERY CONTINUES TO SHOW
AREA OF MVFR/IFR CEILINGS SLOWLY SLIDING EAST ACROSS THE AREA...AND
WITH DRYING ALOFT LATER ON THIS AM CANNOT RULE OUT SOME LIFR CIGS.
ONCE DAYTIME MIXING BEGINS...CIGS TO IMPROVE TO VFR. TIMING TO BE
DEPENDENT UPON WIND DIRECTION...AS ANY UPSLOPE FLOW TO DELAY
IMPROVEMENT IN CIGS. AT THIS TIME...KCMX TO BE THE SLOWEST OUT OF
THE IFR/MVFR CLOUDS AS UPSLOPE NW WINDS TO HELP THESE LOWER CEILINGS
HOLD ON TIL AROUND 14Z. AFTER THEN...EXPECT VFR CONDITIONS AND WINDS
BELOW 10 KNOTS AT ALL THREE TAF SITES THROUGH THE REMAINDER OF THE
FORECAST.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 407 PM EDT FRI JUL 25 2014
EXPECT WINDS UNDER 15 KTS THRU SAT NIGHT WITH RELATIVELY WEAK PRES
GRADIENT DOMINATING THE UPPER LAKES. STRONGER N WINDS UP TO 20-25
KTS EXPECTED SUN INTO MON AS COOLER AIR INVADES THE AREA UNDER
TIGHTER GRADIENT BETWEEN HI PRES MOVING INTO THE NORTHERN PLAINS AND
LO PRES OVER THE SE GREAT LAKES. WINDS WILL DIMINISH ON TUE AND BACK
TOWARD THE W WITH CLOSER APPROACH OF HI PRES FROM THE PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...RJT
MARINE...TITUS/JLA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
318 AM CDT SAT JUL 26 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 318 AM CDT SAT JUL 26 2014
EARLY MORNING WATER VAPOR IMAGERY WITH GFS26.00 500MB HEIGHTS AND
WINDS SHOWED A COMPACT UPPER LEVEL LOW IN SOUTHERN MANITOBA...AND
AN UPPER LEVEL RIDGE CENTERED OVER NORTHERN TEXAS. THIS LED TO QUICK
ZONAL FLOW OVER THE NORTHERN THIRD OF THE CONUS...WITH A WEAK
SHORTWAVE LOCATED OVER CENTRAL SOUTH DAKOTA. THIS SHORTWAVE WAS ABLE
TO FIRE OFF A FEW THUNDERSTORMS OVERNIGHT. THE LEADING EDGE OF THESE
STORMS WERE FALLING APART...AND THE LATEST RUNS OF THE HIRES
MODELS...INCLUDING THE HOPWRF AND HRRR SHOW THE DEVELOPING
CONVECTION DIVING SOUTHEAST OVER SOUTHWEST MINNESOTA AND NORTHERN
IOWA. THEREFORE HAVE INTRODUCED A SLIGHT CHANCE OF POPS ACROSS THE
FAR SOUTHWESTERN CWA.
LATER TODAY INSTABILITY WILL BUILD ALONG A WEAK SURFACE
TROUGH...WITH AN UPPER LEVEL WAVE DIVING DOWN FROM CANADA. THIS WILL
SUPPORT A FEW LATE AFTERNOON SHOWERS AND THUNDERSTORMS MAINLY ACROSS
NORTHERN MN AND WI. FORECAST SOUNDINGS SHOW CIN HOLDING OFF
CONVECTION EARLY IN THE AFTERNOON...WITH DEEP MIXING BY LATE
EVENING. INCREASED THE WINDS ACROSS WESTERN MN TO REFLECT THIS
BOUNDARY LAYER MIXING. CONTINUED PRECIP CHANCES ACROSS THE NORTHEAST
OVERNIGHT SATURDAY WITH COOLER DRIER AIR MOVING IN FROM THE
NORTHWEST.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 318 AM CDT SAT JUL 26 2014
THE UPPER LOW WILL ROTATE SOUTHEASTWARD ACROSS WESTERN WISCONSIN
SUNDAY. SCATTERED TO NUMEROUS SHOWER COVERAGE EXPECTED ACROSS ERN
MN AND WRN WI...WITH ISOLATED LIGHT SHOWERS OR SPRINKLES EXPECTED
FURTHER SOUTHWEST ACROSS WRN/SRN MN. REMOVED THE THUNDER MENTION
DUE TO POOR LAPSE RATES AND LITTLE OR NO INSTABILITY. THIS EVENT
WILL BE SIMILAR TO THE ONE ABOUT 2 WEEKS AGO...EXCEPT THAT THIS
ONE IS A BIT WEAKER AND AREAL COVERAGE OF PRECIP IS NOT EXPECTED
TO BE AS IMPRESSIVE.
CLEARING SKIES WILL FOLLOW SUNDAY NIGHT WHICH WILL MARK THE
BEGINNING OF A LONG STRETCH OF MOSTLY CLEAR SKIES AND SEASONAL OR
SLIGHTLY BELOW NORMAL TEMPERATURES. NOT MUCH TO DISCUSS BEYOND
SUNDAY...EACH DAY WILL MORE OR LESS BE A CARBON COPY OF THE LAST.
THE TROUGH WILL REMAIN PARKED OVER THE GREAT LAKES WITH RIDGING
ACROSS THE ROCKIES AND THE WESTERN ATLANTIC FOR THE NEXT WEEK OR
TWO. REMOVED POPS FOR LATE NEXT WEEK DUE TO VERY WEAK FORCING AND
LITTLE OR NO INSTABILITY. THINKING THE WIDESPREAD QPF OVER WI ON
THE GFS AND ECMWF IS MUCH OVERDONE AND IS LIKELY A RESULT OF AN
OVERESTIMATION OF EVAPOTRANSPIRATION...AND SUPERADIABATIC LAPSE
RATES AT THE SURFACE DUE TO WINDS LESS THAN 3 KT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1243 AM CDT SAT JUL 26 2014
AREAS OF FOG WILL DEVELOP BEHIND THE LOW CLOUDS TONIGHT. BRIEF IFR
CONDITIONS ARE POSSIBLE. DRIER AIR IS SLOWLY MOVING IN FROM THE
NORTHWEST. TODAY CEILINGS WILL LIFT TO VFR. FORECAST SOUNDINGS
SHOW A FEW AFTERNOON SHOWERS POSSIBLE ACROSS THE NORTHEAST.
KMSP...
IN ADDITION TO THE DISCUSSION ABOVE...CONFIDENCE IS TOO LOW TO
INCLUDE THICK FOG OR LOW STRATUS AT KMSP.
/OUTLOOK FOR KMSP/
SUN...VFR WITH MVFR/SHRA POSSIBLE. WINDS NW AT 10G15KTS.
MON...VFR. WINDS N AT 5KTS.
TUE...VFR. WINDS N AT 10KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JRB
LONG TERM...BORGHOFF
AVIATION...JRB
AREA FORECAST DISCUSSION
NWS BISMARCK ND
321 AM CDT SAT JUL 26 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 322 AM CDT SAT JUL 26 2014
THE LATEST SATELLITE IMAGERY SHOWS A COMPACT CLOSED UPPER LOW
CIRCULATING OVER SOUTHEAST SASKATCHEWAN. A 1003MB SURFACE LOW WAS
LOCATED OVER WYNYARD SASKATCHEWAN...DIRECTLY BENEATH THE UPPER LOW.
AS A RESULT...THE LOW CONTINUES TO FILL/WEAKEN WITH TIME. ATTACHED
TO THE LOW IS A COLD FRONTAL BOUNDARY EXTENDING FROM SOUTHEAST
SASKATCHEWAN INTO MINOT AND GARRISON...AND CONTINUING SOUTH TO
GLEN ULLIN AND HETTINGER. COLD AIR ADVECTION TODAY COMBINED WITH A
DECENT PRESSURE GRADIENT SETTING UP FROM EASTERN MONTANA TO
NORTHWEST MINNESOTA WILL RESULT IN WINDY CONDITIONS. AS IS USUALLY
THE CASE...INCLUDING TODAYS DATA...THE MET/NAM WIND GUIDANCE IS
WEAKER THAN THE MAV/GFS. THE LATEST RAP13 AND ECMWF FAVORS THE
LOWER END OF STRONGEST WINDS. THIS ULTIMATELY SUGGESTS A WEAK
CONFIDENCE LEVEL FOR A WIND ADVISORY. WOULD LIKE TO MORE AGREEMENT
AMONGST THE FORECAST DATA WITH HIGHER SUSTAINED WINDS. THUS HAVE
DECIDED TO HOLD OFF ON ISSUING A WIND ADVISORY AS IT REMAINS
MARGINAL AT THIS TIME. THE DAY SHIFT CAN HAVE ANOTHER LOOK AS WINDS
INCREASE BY MID/LATE MORNING TO COMPARE ACTUAL VERSUS FORECAST.
OTHERWISE THE LATEST FOG/STRATUS LOOP SHOWS A LARGE SWATH OF
LOW/MID LEVEL BKN/OVC CLOUDS ASSOCIATED WITH THE SURFACE/UPPER LOW
CIRCULATION OVER SOUTHERN SASKATCHEWAN. THESE ARE NOW BEGINNING TO
CROSS THE NORTHWEST CORNER OF THE STATE. THE HRRR SHOWS THIS BAND
OF CLOUDS ARCING INTO WILLISTON AND MINOT BETWEEN 16Z-17Z. THERE
WILL BE AN AREA OF ISOLATED TO SCATTERED RAINSHOWERS AND ISOLATED
THUNDERSTORMS OVER THE NORTH CENTRAL TODAY. THE NAM WAS MOST
AGGRESSIVE IN GENERATING PRECIPITATION INTO SOUTH CENTRAL NORTH
DAKOTA THIS AFTERNOON. BUT WITH ALL OTHER MODELS MAINTAINING THE
THREAT OVER THE NORTH...HAVE DISCOUNTED THE NAM AND CONTINUED/REFINED
WITH WHAT THE PREVIOUS FORECAST HAD. HIGHS TODAY IN THE NORTH WITH
MOSTLY CLOUDY/WINDY/WET CONDITIONS WILL REACH THE UPPER 60S.
IN THE CENTRAL AND SOUTH...EXPECT MOSTLY SUNNY AND WINDY WEATHER
WITH HIGHS AROUND 80.
ALSO...SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER CENTRAL AND
NORTHERN SOUTH DAKOTA ALONG AND NORTH OF A LOW LEVEL CONVERGENCE
FIELD/FRONTAL BOUNDARY. THERE IS SOME HINT PER RAP13 THAT SHOWERS
WILL ENTER FAR SOUTHERN NORTH DAKOTA THROUGH 15Z SATURDAY. WILL
CONTINUE TO MONITOR THIS AND ADJUST AT THE LAST MINUTE IF TRENDS
CONTINUE TO SHOW DEVELOPMENT FARTHER NORTH.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 322 AM CDT SAT JUL 26 2014
THE EXTENDED PERIOD BEGINS THE AN UPPER LOW OVER SOUTH CENTRAL
CANADA THAT WILL MOVE SOUTHEAST AND MERGE INTO A LARGE HUDSON BAY
TROUGH SETTING UP A BLOCKING PATTERN ACROSS EASTERN NORTH AMERICA
WHICH WILL MAINTAIN A RIDGE OVER THE WESTERN US AND A TROUGH OVER
THE EAST. THE NORTHERN PLAINS WILL BE IN FOR A PERIOD OF QUIET
WEATHER FOR THIS EXTENDED PERIOD. FOR THE FIRST PORTION OF THE
FORECAST...SUNDAY THROUGH WEDNESDAY...EXPECT MAINLY DRY WEATHER
WITH A SLOW WARMING TREND. HIGHS IN THE UPPER 60S TO MID 70S ON
SUNDAY WILL MODERATE TO THE LOWER TO MIDDLE 80S BY WEDNESDAY
THROUGH FRIDAY. WITH THE H500 RIDGE FIRMLY IN PLACE OVER THE
WESTERN US ONLY A FEW WEAK IMPULSES MAY BE ABLE TO DRIFT ACROSS
THE NORTHERN PLAINS. FOR THIS POSSIBILITY LEFT WIDELY SCATTERED
CHANCES FOR THUNDERSTORMS WEDNESDAY WITH THURSDAY AND FRIDAY
BASICALLY DRY AND WARM.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 322 AM CDT SAT JUL 26 2014
MAIN THEME TODAY WILL BE GUSTY WEST TO NORTHWESTERLY WINDS BETWEEN
25KT AND 35KT ACROSS THE TERMINALS. THESE WINDS WILL ABATE BY 02Z
SUNDAY. ALSO...LOW VFR/MVFR CIGS OVER SOUTHERN SASKATCHEWAN WILL
SAG INTO NORTHERN NORTH DAKOTA. THIS WILL IMPACT KISN/KMOT FROM
16Z SATURDAY THROUGH 02Z SUNDAY WITH LOW VFR CONDITIONS MIXED IN
WITH BRIEF PERIODS OF MVFR. THE REST OF THE TERMINALS WILL REMAIN VFR.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KS
LONG TERM...WAA
AVIATION...KS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
320 AM CDT SAT JUL 26 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CDT SAT JUL 26 2014
LATEST WATER VAPOR SATELLITE IMAGERY INDICATING UPPER LEVEL CLOSED
LOW OVER SOUTHERN SASKATCHEWAN AND WEST TO EAST ZONAL FLOW OVER
THE NORTHERN PLAINS. WEAK SHORTWAVE TROUGH OVER CENTRAL AND
EASTERN SOUTH DAKOTA EMBEDDED IN WEST TO EAST ZONAL FLOW IS
PRODUCING SHOWERS AND ISOLATED THUNDERSTORMS OVER CENTRAL SOUTH
DAKOTA PER MOSAIC RADAR.
MAIN FORECAST CONCERNS ARE PRECIPITATION CHANCES TODAY INTO TONIGHT.
THE 26.00Z GFS/NAM ARE IN GOOD AGREEMENT IN MOVING WEAK IMPULSE OVER
CENTRAL SOUTH DAKOTA INTO THE SOUTHERN PART OF THE FORECAST AREA.
THE 26.00Z GFS/NAM ARE INDICATING ISENTROPIC LIFT AT 315K SURFACE
AND PRODUCE LIGHT QPF ACROSS PARTS OF NORTHEAST IOWA AND SOUTHWEST
WISCONSIN. THE LATEST 26.05Z HRRR IS INDICATING THE SHRA/TSRA OVER
CENTRAL SOUTH DAKOTA TO WEAKEN AND POSSIBLY PRODUCE LIGHT SHOWERS OR
SPRINKLES OVER THE SOUTHERN PART OF THE FORECAST AREA. BUFKIT
SOUNDINGS SHOW QUITE A BIT OF DRY AIRMASS BELOW 700MB OVER THE
SOUTHERN FORECAST AREA. HOWEVER...WITH THE LIFT ASSOCIATED WITH THE
WEAK IMPULSE...THIS MAY PRODUCE AN ISOLATE SHRA/TSRA ACROSS SOUTHERN
FORECAST AREA THIS MORNING INTO THE EARLY AFTERNOON HOURS. HAVE
INTRODUCE A SMALL CHANCE OF PRECIPITATION OVER NORTHEAST IOWA AND
PARTS OF SOUTHWEST WISCONSIN.
UPPER LEVEL CLOSED LOW OVER SOUTHERN SASKATCHEWAN MOVES SOUTH
INTO THE GREAT LAKES REGION TONIGHT. THE 26.00Z GFS/NAM SUGGEST
INCREASING FORCING/LIFT AFTER 06Z OVER NORTHERN PARTS OF THE
FORECAST AREA AND INDICATE ELEVATED CAPE ASSOCIATED WITH UPPER
LEVEL CLOSED LOW. WILL CONTINUE TREND OF PRECIPITATION CHANCES
ACROSS THE NORTHERN PARTS OF THE FORECAST AREA.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 320 AM CDT SAT JUL 26 2014
SUNDAY...THE 26.00Z GFS/NAM CONTINUE TO SHOW DECENT 500-300MB PV
ADVECTION AND DEEP QG FORCING ASSOCIATED WITH THE CLOSED UPPER LEVEL
LOW OVER MUCH OF THE NORTHERN AND EASTERN PART OF THE FORECAST
AREA. CONFIDENCE IS INCREASING THIS AREA WILL SEE SHOWERS AND
POSSIBLY AN ISOLATED THUNDERSTORM.
THE 26.00Z GFS/GEM/ECMWF ARE IN GOOD AGREEMENT DIGGING UPPER LEVEL
TROUGH OVER THE EASTERN UNITED STATES SUNDAY NIGHT INTO FRIDAY. THE
MAIN DIFFERENCE BETWEEN THE MODELS IS TIMING THE VERY WEAK IMPULSES
EMBEDDED IN THE NORTHERLY FLOW ALOFT INTO THE GREAT LAKES REGION.
THE MODELS CONTINUE TO PRODUCE LIGHT QPF OVER PARTS OF THE
FORECAST AREA MAINLY FROM WEDNESDAY INTO FRIDAY. HOWEVER...WITH
VERY WEAK MOISTURE CONVERGENCE AND VERY WEAK IMPULSES EMBEDDED IN
NORTHERLY FLOW. CONFIDENCE IN PRECIPITATION CHANCES IS LOW THROUGH
THIS PERIOD.
TEMPERATURES SUNDAY NIGHT INTO FRIDAY WILL BE UNSEASONABLY COOL
THROUGH MIDDLE OF THE WEEK AND MODERATE TO NEAR NORMAL BY END OF THE
WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1154 PM CDT FRI JUL 25 2014
THE FIRST 6 HOURS OR SO OF THE AVIATION FORECAST IS VERY
PROBLEMATIC. CEILINGS HAVE BEEN GRADUALLY LOWERING THROUGH THE
EVENING DUE TO A COMBINATION OF NOCTURNAL COOLING AND A LITTLE
MORE MOISTURE BEING SENT NORTHWARD INTO THE TAF SITES. EVEN SOME
DRIZZLE HAS FORMED...REDUCING VISIBILITIES TO MVFR AT RST.
MEANWHILE...DRIER AIR AS EXPECTED IS BEGINNING TO MOVE INTO
SOUTHEAST MN WITH TOB NOW VFR. AS WE HEAD THROUGH THE EARLY
MORNING HOURS...ANTICIPATING THAT DRIER AIR TO MOVE INTO RST...
CAUSING THE CLOUDS TO SCATTER OUT AND THUS GO VFR. HOWEVER...THIS
SAME CLEARING MAY ALLOW IFR OR LOWER VISIBILITY BR TO DEVELOP...
WHICH IS NOTED IN A TEMPO GROUP. ANY FOG SHOULD DISSIPATE QUICKLY
AFTER SUNRISE. AT LSE...IT APPEARS THE CLEARING MAY TAKE LONGER TO
GET THERE...THUS HAVE LEFT THE PREVIOUS PLAN OF CONDITIONS
CLIMBING TO VFR AFTER 13Z. ITS POSSIBLE LSE DROPS TO IFR EARLY
THIS MORNING. AFTER 13Z...PLENTIFUL DRY AIR LOOKS TO BE PRESENT
ABOVE THE SURFACE TO NEARLY 10000 FT TO ALLOW FOR VFR CONDITIONS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS NEW YORK NY
749 AM EDT SAT JUL 26 2014
.SYNOPSIS...
HIGH PRESSURE WILL MOVE FURTHER OUT TO SEA TODAY AS A WARM FRONT
APPROACHES FROM THE SOUTHWEST. THIS FRONT WILL LIFT THROUGH THE
AREA SUNDAY MORNING WITH A COLD FRONT APPROACHING SUNDAY NIGHT. A
WAVE OF LOW PRESSURE EXPECTED TO DEVELOP ON THE COLD
FRONT...LIFTING THROUGH NEW ENGLAND ON MONDAY AS THE FRONT SLOWLY
SLIDES ACROSS. HIGH PRESSURE THEN BUILDS IN BEHIND THE FRONT BY THE
MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FORECAST IS GENERALLY ON TRACK. WATCHING AREA OF QUICK MOVING
SHOWERS ENTERING EASTERN PA EARLY THIS MORNING...ASSOCIATED WITH
MID LEVEL SHORTWAVE TROUGH. MOST OF THE MODEL GUIDANCE...INCLUDING
THE HIGH RES SOLNS...DOES NOT EVEN CAPTURE THIS...BUT THE FEW THAT
DO...THE RUC AND HRRR WEAKENS IT AS IT REACHES THE PA/NJ BORDER.
IN LIGHT OF THIS...WILL KEEP THE FORECAST DRY FOR NOW...BUT
SCHC/LOW CHC POPS MAY NEED TO BE ADDED TO WESTERN ZONES IN AN
HOUR OR SO DEPENDING ON TRENDS.
OTHERWISE...HIGH PRES OFF THE MID ATLANTIC COAST WILL CONTINUE
EWD TODAY WITH A MEAN TROUGH PERSISTING ALOFT. FAIRLY BENIGN
WEATHER IS EXPECTED...WITH THE EXCEPTION OF A FEW ISOLD SHRA/TSTMS
THIS AFTN...MAINLY ACROSS THE WESTERN HALF OF THE FORECAST AREA.
A DECENT AMOUNT OF CLOUD COVER IS EXPECTED TODAY WITH A WAA REGIME
WHICH WILL HOLD HIGH TEMPS RIGHT AROUND NORMAL LEVELS IN THE LOWER
TO MID 80S.
THERE IS A MODERATE RISK OF RIP CURRENTS ALONG ATLANTIC FACING
BEACHES THROUGH THIS EVENING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
A WARM FRONT APPROACHES TONIGHT AND LIFTS THROUGH SUN MORNING. THE
COMBINATION OF A MID LEVEL SHORTWAVE AND THE LEFT EXIT REGION OF A
90KT H250 JET WILL RESULT IN INCREASING CHC`S OF SHRA/TSTMS ACROSS
THE AREA LATE TONIGHT INTO SUN MORNING. UNCERTAINTY IN POPS AND
SKY BEHIND THE WARM FROPA. IF THERE ARE ANY BREAKS IN THE CLOUDS
WE`LL WARM UP FAST AND COULD HIT 90 IN METRO NY/NJ. ANY SUN WILL
ALSO RESULT IN DESTABILIZATION DURING THE AFTN AND COULD TRIGGER
ADDITIONAL STORMS...SOME OF WHICH COULD REACH SVR LIMITS. MUGGY
CONDS WILL BECOME NOTICEABLE AND PERSIST UNTIL THE COLD FRONT
PUSHES THROUGH SOMETIME MON NIGHT.
THIS IS WHERE THE FORECAST GETS INTERESTING WITH THE FOCUS TURNING
TO A WEAKENING CUTOFF LOW DROPPING THROUGH THE UPPER MIDWEST
TONIGHT...THE GREAT LAKES SUN AND PIVOTING THROUGH NEW ENGLAND ON MON.
SOME OF THE MODEL GUIDANCE IS INDICATING A SECONDARY AREA OF LOW
PRES DEVELOPING OVER CENTRAL NJ SUN NIGHT...WHILE OTHERS KEEP THE
PARENT LOW IN CONTROL FURTHER N AND W. CONSIDERABLE SPREAD REMAINS
AMONGST THE GUIDANCE WITH REGARDS TO TIMING AND TRACK OF THE LOW.
THE 00Z NAM IS THE WORST CASE SCENARIO WITH THE LOW TRACKING NE
FROM CENTRAL NJ TO MA WITH 60+KT OF 0-6KM BULK SHEAR (~15KT 0-1KM
SHEAR)...APPROX 1K J/KG OF SBCAPE...400-500 M2/S2 OF SFC-1KM
HELICITY AND AN LCL BELOW 1K FT AROUND 06Z MON. THIS WOULD BE
SUFFICIENT FOR ROTATING STORMS. HOWEVER IF THIS SECONDARY LOW DOES
NOT DEVELOP THE MOST SEVERE STORMS SHOULD REMAIN FURTHER N AND W.
NEEDLESS TO SAY...STILL SOME FAIRLY BIG UNCERTAINTY IN HOW MUCH OF
AN IMPACT THIS WILL BE...BUT SINCE THERE IS THE THREAT FOR SVR WX
HAVE ADDED ENHANCED WORDING TO THE FORECAST SUN AFTN AND NIGHT.
PWATS INCREASING TO NEAR 2 INCHES ALSO INDICATE THE POTENTIAL FOR
HEAVY RAIN IN ANY THUNDERSTORMS.
FRONT IS SLOW TO MOVE ACROSS THE AREA ON MON...AND THE POTENTIAL
FOR MORE SHRA/TSTMS WILL CONTINUE MON AFTN.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
UPPER TROUGH/CUTOFF LOW PERSISTS INTO THE MIDDLE OF THE WEEK WITH
WEAK HIGH PRES IN CONTROL AT THE SFC. SCHC/CHC SHRA/TSTMS MON
NIGHT/TUE AS A RESULT. WEATHER PATTERN BEGINS TO STABILIZE WITH
HEIGHTS BUILDING AS THE UPPER LEVEL TROUGH BEGINS TO LIFT NORTH OF
THE REGION DURING THE SECOND HALF OF THE WEEK. AT THE SURFACE...HIGH
PRESSURE WILL BEGIN TO BUILD IN FROM THE WEST.
THE HIGH PRESSURE CONTINUES TO BUILD IN AND THE UPPER LEVEL TROUGH
AMPLITUDE CONTINUES TO WEAKEN WITH TIME THROUGH THE REST OF THIS
PERIOD. THIS WILL ALLOW FOR A DRY AIRMASS TO ENCOMPASS THE REGION.
TEMPERATURES WILL NOT DEVIATE TOO MUCH FROM NORMAL.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE GIVES WAY TO A SURFACE TROUGH AND WARM FRONT THAT WILL
APPROACH FROM THE WEST.
MAINLY VFR CONDITIONS ARE EXPECTED. INCREASING MIDDLE AND HIGH LEVEL
CLOUDS ARE FORECAST. AN ISOLATED SHOWER OR THUNDERSTORM IS
POSSIBLE...WITH BETTER CHANCE WEST OF NYC TERMINALS.
HOWEVER...ACTIVITY WOULD BE TOO ISOLATED TO INCLUDE IN THE
FORECAST AT THIS TIME. BRIEF SUB VFR CONDITIONS ARE POSSIBLE IN
ANY SHOWER OR TSTM.
SOUTHWEST WINDS 10 KTS OR LESS THIS MORNING WILL BECOME SOUTH 10 TO
15 KTS THIS AFTERNOON. A FEW GUSTS UP TO 20 KT ARE
POSSIBLE...HOWEVER GUSTS WILL NOT BE FREQUENT ENOUGH TO INCLUDE
IN THE FORECAST. WINDS LIGHTEN SOMEWHAT TONIGHT.
THERE IS A BETTER CHANCE FOR SHOWERS AND POSSIBLE TSTMS LATER
TONIGHT. SUB VFR POSSIBLE.
.OUTLOOK FOR 12Z SUN THROUGH WED...
.SUN-MON...MAINLY VFR. A CHANCE OF SHRA/TSTMS WITH MVFR OR LOWER
POSSIBLE AT TIMES.
.TUE-WED...VFR.
&&
.MARINE...
SOUTH/SOUTHWEST WINDS ARE FORECAST TODAY AND TONIGHT. THESE WINDS
INCREASE SUNDAY AND SUNDAY NIGHT OUT AHEAD OF LOW PRESSURE AND
ASSOCIATED COLD FRONT. SEAS BUILD AS A RESULT LATE SUNDAY THROUGH
SUNDAY NIGHT AND REMAIN RATHER ROUGH MONDAY. SMALL CRAFT ADVISORY
HEADLINES MAY BE NEEDED EVENTUALLY FOR THE SUNDAY NIGHT THROUGH
MONDAY TIME FRAME ACROSS THE OCEAN WATERS.
WINDS GRADUALLY SHIFT TO THE WEST BEHIND THE SLOW MOVING FRONT LATE
MONDAY AND MONDAY NIGHT...AND SPEEDS DIMINISH SOMEWHAT.
WEST OR NORTHWEST WINDS CAN BE EXPECTED TUESDAY AND WEDNESDAY.
ROUGH SEAS SUBSIDE TUESDAY AND WEDNESDAY.
&&
.HYDROLOGY...
UNSETTLED WEATHER WITH SCATTERED TO NUMEROUS SHOWERS/TSTMS ARE
FORECAST LATE TONIGHT THROUGH MONDAY. ANY OF THESE STORMS HAVE
THE POTENTIAL TO PRODUCE HEAVY DOWNPOURS. SIGNIFICANT UNCERTAINTY
STILL EXISTS WITH TIMING AND AMOUNTS THOUGH. IT LOOKS LIKE THE
HIGHER POTENTIAL FOR HEAVY RAIN IS SUNDAY AFTN AND SUNDAY NIGHT
WITH HIGHER PWATS OF 1.5 TO 2 INCHES ACROSS THE REGION.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...24
NEAR TERM...24
SHORT TERM...24
LONG TERM...24
AVIATION...PW
MARINE...PW
HYDROLOGY...24
AREA FORECAST DISCUSSION
NWS NEW YORK NY
717 AM EDT SAT JUL 26 2014
.SYNOPSIS...
HIGH PRESSURE WILL MOVE FURTHER OUT TO SEA TODAY AS A WARM FRONT
APPROACHES FROM THE SOUTHWEST. THIS FRONT WILL LIFT THROUGH THE
AREA SUNDAY MORNING WITH A COLD FRONT APPROACHING SUNDAY NIGHT. A
WAVE OF LOW PRESSURE EXPECTED TO DEVELOP ON THE COLD
FRONT...LIFTING THROUGH NEW ENGLAND ON MONDAY AS THE FRONT SLOWLY
SLIDES ACROSS. HIGH PRESSURE THEN BUILDS IN BEHIND THE FRONT BY THE
MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FORECAST IS GENERALLY ON TRACK. WATCHING AREA OF QUICK MOVING
SHOWERS ENTERING EASTERN PA EARLY THIS MORNING...ASSOCIATED WITH
MID LEVEL SHORTWAVE TROUGH. MOST OF THE MODEL GUIDANCE...INCLUDING
THE HIGH RES SOLNS...DOES NOT EVEN CAPTURE THIS...BUT THE FEW THAT
DO...THE RUC AND HRRR WEAKENS IT AS IT REACHES THE PA/NJ BORDER.
IN LIGHT OF THIS...WILL KEEP THE FORECAST DRY FOR NOW...BUT
SCHC/LOW CHC POPS MAY NEED TO BE ADDED TO WESTERN ZONES IN AN
HOUR OR SO DEPENDING ON TRENDS.
OTHERWISE...HIGH PRES OFF THE MID ATLANTIC COAST WILL CONTINUE
EWD TODAY WITH A MEAN TROUGH PERSISTING ALOFT. FAIRLY BENIGN
WEATHER IS EXPECTED...WITH THE EXCEPTION OF A FEW ISOLD SHRA/TSTMS
THIS AFTN...MAINLY ACROSS THE WESTERN HALF OF THE FORECAST AREA.
A DECENT AMOUNT OF CLOUD COVER IS EXPECTED TODAY WITH A WAA REGIME
WHICH WILL HOLD HIGH TEMPS RIGHT AROUND NORMAL LEVELS IN THE LOWER
TO MID 80S.
THERE IS A MODERATE RISK OF RIP CURRENTS ALONG ATLANTIC FACING
BEACHES THROUGH THIS EVENING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
A WARM FRONT APPROACHES TONIGHT AND LIFTS THROUGH SUN MORNING. THE
COMBINATION OF A MID LEVEL SHORTWAVE AND THE LEFT EXIT REGION OF A
90KT H250 JET WILL RESULT IN INCREASING CHC`S OF SHRA/TSTMS ACROSS
THE AREA LATE TONIGHT INTO SUN MORNING. UNCERTAINTY IN POPS AND
SKY BEHIND THE WARM FROPA. IF THERE ARE ANY BREAKS IN THE CLOUDS
WE`LL WARM UP FAST AND COULD HIT 90 IN METRO NY/NJ. ANY SUN WILL
ALSO RESULT IN DESTABILIZATION DURING THE AFTN AND COULD TRIGGER
ADDITIONAL STORMS...SOME OF WHICH COULD REACH SVR LIMITS. MUGGY
CONDS WILL BECOME NOTICEABLE AND PERSIST UNTIL THE COLD FRONT
PUSHES THROUGH SOMETIME MON NIGHT.
THIS IS WHERE THE FORECAST GETS INTERESTING WITH THE FOCUS TURNING
TO A WEAKENING CUTOFF LOW DROPPING THROUGH THE UPPER MIDWEST
TONIGHT...THE GREAT LAKES SUN AND PIVOTING THROUGH NEW ENGLAND ON MON.
SOME OF THE MODEL GUIDANCE IS INDICATING A SECONDARY AREA OF LOW
PRES DEVELOPING OVER CENTRAL NJ SUN NIGHT...WHILE OTHERS KEEP THE
PARENT LOW IN CONTROL FURTHER N AND W. CONSIDERABLE SPREAD REMAINS
AMONGST THE GUIDANCE WITH REGARDS TO TIMING AND TRACK OF THE LOW.
THE NAM IS THE WORST CASE SCENARIO WITH THE LOW TRACKING NE FROM
CENTRAL NJ TO MA WITH 60+KT OF 0-6KM BULK SHEAR (~15KT 0-1KM
SHEAR)...APPROX 1K J/KG OF SBCAPE...400-500 M2/S2 OF SFC-1KM
HELICITY AND AN LCL BELOW 1K FT AROUND 06Z MON. THIS WOULD BE
SUFFICIENT FOR ROTATING STORMS. HOWEVER IF THIS SECONDARY LOW DOES
NOT DEVELOP THE MOST SEVERE STORMS SHOULD REMAIN FURTHER N AND W.
NEEDLESS TO SAY...STILL SOME FAIRLY BIG UNCERTAINTY IN HOW MUCH OF
AN IMPACT THIS WILL BE...BUT SINCE THERE IS THE THREAT FOR SVR
WX HAVE ADDED ENHANCED WORDING TO THE FORECAST SUN AFTN AND NIGHT.
PWATS INCREASING TO NEAR 2 INCHES ALSO INDICATE THE POTENTIAL FOR
HEAVY RAIN IN ANY THUNDERSTORMS.
FRONT IS SLOW TO MOVE ACROSS THE AREA ON MON...AND THE POTENTIAL
FOR MORE SHRA/TSTMS WILL CONTINUE MON AFTN.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
UPPER TROUGH/CUTOFF LOW PERSISTS INTO THE MIDDLE OF THE WEEK WITH
WEAK HIGH PRES IN CONTROL AT THE SFC. SCHC/CHC SHRA/TSTMS MON
NIGHT/TUE AS A RESULT. WEATHER PATTERN BEGINS TO STABILIZE WITH
HEIGHTS BUILDING AS THE UPPER LEVEL TROUGH BEGINS TO LIFT NORTH OF
THE REGION DURING THE SECOND HALF OF THE WEEK. AT THE SURFACE...HIGH
PRESSURE WILL BEGIN TO BUILD IN FROM THE WEST.
THE HIGH PRESSURE CONTINUES TO BUILD IN AND THE UPPER LEVEL TROUGH
AMPLITUDE CONTINUES TO WEAKEN WITH TIME THROUGH THE REST OF THIS
PERIOD. THIS WILL ALLOW FOR A DRY AIRMASS TO ENCOMPASS THE REGION.
TEMPERATURES WILL NOT DEVIATE TOO MUCH FROM NORMAL.
&&
.AVIATION /11Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE GIVES WAY TO A SURFACE TROUGH AND WARM FRONT THAT WILL
APPROACH FROM THE WEST.
MAINLY VFR CONDITIONS ARE EXPECTED. INCREASING MIDDLE AND HIGH LEVEL
CLOUDS ARE FORECAST. AN ISOLATED SHOWER OR THUNDERSTORM IS POSSIBLE
MAINLY WEST OF NYC TERMINALS THIS AFTERNOON. HOWEVER...ACTIVITY
WOULD BE TOO ISOLATED TO INCLUDE IN THE FORECAST AT THIS TIME.
BRIEF SUB VFR CONDITIONS ARE POSSIBLE IN ANY SHOWER OR TSTM.
SOUTHWEST WINDS 10 KTS OR LESS THIS MORNING WILL BECOME SOUTH 10 TO
15 KTS THIS AFTERNOON. A FEW GUSTS UP TO 20 KT ARE
POSSIBLE...HOWEVER GUSTS WILL NOT BE FREQUENT ENOUGH TO INCLUDE
IN THE FORECAST. WINDS LIGHTEN SOMEWHAT TONIGHT.
THERE IS A BETTER CHANCE FOR SHOWERS AND POSSIBLE TSTMS LATER
TONIGHT. SUB VFR POSSIBLE.
.OUTLOOK FOR 12Z SUN THROUGH WED...
.SUN-MON...MAINLY VFR. A CHANCE OF SHRA/TSTMS WITH MVFR OR LOWER
POSSIBLE AT TIMES.
.TUE-WED...VFR.
&&
.MARINE...
SOUTH/SOUTHWEST WINDS ARE FORECAST TODAY AND TONIGHT. THESE WINDS
INCREASE SUNDAY AND SUNDAY NIGHT OUT AHEAD OF LOW PRESSURE AND
ASSOCIATED COLD FRONT. SEAS BUILD AS A RESULT LATE SUNDAY THROUGH
SUNDAY NIGHT AND REMAIN RATHER ROUGH MONDAY. SMALL CRAFT ADVISORY
HEADLINES MAY BE NEEDED EVENTUALLY FOR THE SUNDAY NIGHT THROUGH
MONDAY TIME FRAME ACROSS THE OCEAN WATERS.
WINDS GRADUALLY SHIFT TO THE WEST BEHIND THE SLOW MOVING FRONT LATE
MONDAY AND MONDAY NIGHT...AND SPEEDS DIMINISH SOMEWHAT.
WEST OR NORTHWEST WINDS CAN BE EXPECTED TUESDAY AND WEDNESDAY.
ROUGH SEAS SUBSIDE TUESDAY AND WEDNESDAY.
&&
.HYDROLOGY...
UNSETTLED WEATHER WITH SCATTERED TO NUMEROUS SHOWERS/TSTMS ARE
FORECAST LATE TONIGHT THROUGH MONDAY. ANY OF THESE STORMS HAVE
THE POTENTIAL TO PRODUCE HEAVY DOWNPOURS. SIGNIFICANT UNCERTAINTY
STILL EXISTS WITH TIMING AND AMOUNTS THOUGH. IT LOOKS LIKE THE
HIGHER POTENTIAL FOR HEAVY RAIN IS SUNDAY AFTN AND SUNDAY NIGHT
WITH HIGHER PWATS OF 1.5 TO 2 INCHES ACROSS THE REGION.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...24
NEAR TERM...24
SHORT TERM...24
LONG TERM...24
AVIATION...PW
MARINE...PW
HYDROLOGY...24
AREA FORECAST DISCUSSION
NWS NEW YORK NY
647 AM EDT SAT JUL 26 2014
.SYNOPSIS...
HIGH PRESSURE WILL MOVE FURTHER OUT TO SEA TODAY AS A WARM FRONT
APPROACHES FROM THE SOUTHWEST. THIS FRONT WILL LIFT THROUGH THE
AREA SUNDAY MORNING WITH A COLD FRONT APPROACHING SUNDAY NIGHT. A
WAVE OF LOW PRESSURE EXPECTED TO DEVELOP ON THE COLD
FRONT...LIFTING THROUGH NEW ENGLAND ON MONDAY AS THE FRONT SLOWLY
SLIDES ACROSS. HIGH PRESSURE THEN BUILDS IN BEHIND THE FRONT BY THE
MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FORECAST IS GENERALLY ON TRACK. WATCHING AREA OF QUICK MOVING
SHOWERS ENTERING EASTERN PA EARLY THIS MORNING...ASSOCIATED WITH
MID LEVEL SHORTWAVE TROUGH. MOST OF THE MODEL GUIDANCE...INCLUDING
THE HIGH RES SOLNS...DOES NOT EVEN CAPTURE THIS...BUT THE FEW THAT
DO...THE RUC AND HRRR WEAKENS IT AS IT REACHES THE PA/NJ BORDER.
IN LIGHT OF THIS...WILL KEEP THE FORECAST DRY FOR NOW...BUT
SCHC/LOW CHC POPS MAY NEED TO BE ADDED TO WESTERN ZONES IN AN
HOUR OR SO DEPENDING ON TRENDS.
OTHERWISE...HIGH PRES OFF THE MID ATLANTIC COAST WILL CONTINUE
EWD TODAY WITH A MEAN TROUGH PERSISTING ALOFT. FAIRLY BENIGN
WEATHER IS EXPECTED...WITH THE EXCEPTION OF A FEW ISOLD SHRA/TSTMS
THIS AFTN...MAINLY ACROSS THE WESTERN HALF OF THE FORECAST AREA.
A DECENT AMOUNT OF CLOUD COVER IS EXPECTED TODAY WITH A WAA REGIME
WHICH WILL HOLD HIGH TEMPS RIGHT AROUND NORMAL LEVELS IN THE LOWER
TO MID 80S.
THERE IS A MODERATE RISK OF RIP CURRENTS ALONG ATLANTIC FACING
BEACHES THROUGH THIS EVENING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
A WARM FRONT APPROACHES TONIGHT AND LIFTS THROUGH SUN MORNING. THE
COMBINATION OF A MID LEVEL SHORTWAVE AND THE LEFT EXIT REGION OF A
90KT H250 JET WILL RESULT IN INCREASING CHC`S OF SHRA/TSTMS ACROSS
THE AREA LATE TONIGHT INTO SUN MORNING. UNCERTAINTY IN POPS AND
SKY BEHIND THE WARM FROPA. IF THERE ARE ANY BREAKS IN THE CLOUDS
WE`LL WARM UP FAST AND COULD HIT 90 IN METRO NY/NJ. ANY SUN WILL
ALSO RESULT IN DESTABILIZATION DURING THE AFTN AND COULD TRIGGER
ADDITIONAL STORMS...SOME OF WHICH COULD REACH SVR LIMITS. MUGGY
CONDS WILL BECOME NOTICEABLE AND PERSIST UNTIL THE COLD FRONT
PUSHES THROUGH SOMETIME MON NIGHT.
THIS IS WHERE THE FORECAST GETS INTERESTING WITH THE FOCUS TURNING
TO A WEAKENING CUTOFF LOW DROPPING THROUGH THE UPPER MIDWEST
TONIGHT...THE GREAT LAKES SUN AND PIVOTING THROUGH NEW ENGLAND ON MON.
SOME OF THE MODEL GUIDANCE IS INDICATING A SECONDARY AREA OF LOW
PRES DEVELOPING OVER CENTRAL NJ SUN NIGHT...WHILE OTHERS KEEP THE
PARENT LOW IN CONTROL FURTHER N AND W. CONSIDERABLE SPREAD REMAINS
AMONGST THE GUIDANCE WITH REGARDS TO TIMING AND TRACK OF THE LOW.
THE NAM IS THE WORST CASE SCENARIO WITH THE LOW TRACKING NE FROM
CENTRAL NJ TO MA WITH 60+KT OF 0-6KM BULK SHEAR (~15KT 0-1KM
SHEAR)...APPROX 1K J/KG OF SBCAPE...400-500 M2/S2 OF SFC-1KM
HELICITY AND AN LCL BELOW 1K FT AROUND 06Z MON. THIS WOULD BE
SUFFICIENT FOR ROTATING STORMS. HOWEVER IF THIS SECONDARY LOW DOES
NOT DEVELOP THE MOST SEVERE STORMS SHOULD REMAIN FURTHER N AND W.
NEEDLESS TO SAY...STILL SOME FAIRLY BIG UNCERTAINTY IN HOW MUCH OF
AN IMPACT THIS WILL BE...BUT SINCE THERE IS THE THREAT FOR SVR
WX HAVE ADDED ENHANCED WORDING TO THE FORECAST SUN AFTN AND NIGHT.
PWATS INCREASING TO NEAR 2 INCHES ALSO INDICATE THE POTENTIAL FOR
HEAVY RAIN IN ANY THUNDERSTORMS.
FRONT IS SLOW TO MOVE ACROSS THE AREA ON MON...AND THE POTENTIAL
FOR MORE SHRA/TSTMS WILL CONTINUE MON AFTN.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
UPPER TROUGH/CUTOFF LOW PERSISTS INTO THE MIDDLE OF THE WEEK WITH
WEAK HIGH PRES IN CONTROL AT THE SFC. SCHC/CHC SHRA/TSTMS MON
NIGHT/TUE AS A RESULT. WEATHER PATTERN BEGINS TO STABILIZE WITH
HEIGHTS BUILDING AS THE UPPER LEVEL TROUGH BEGINS TO LIFT NORTH OF
THE REGION DURING THE SECOND HALF OF THE WEEK. AT THE SURFACE...HIGH
PRESSURE WILL BEGIN TO BUILD IN FROM THE WEST.
THE HIGH PRESSURE CONTINUES TO BUILD IN AND THE UPPER LEVEL TROUGH
AMPLITUDE CONTINUES TO WEAKEN WITH TIME THROUGH THE REST OF THIS
PERIOD. THIS WILL ALLOW FOR A DRY AIRMASS TO ENCOMPASS THE REGION.
TEMPERATURES WILL NOT DEVIATE TOO MUCH FROM NORMAL.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE GIVES WAY TO A SURFACE TROUGH AND WARM FRONT THAT WILL
APPROACH FROM THE WEST.
MAINLY VFR CONDITIONS ARE EXPECTED. INCREASING MIDDLE AND HIGH LEVEL
CLOUDS ARE FORECAST. AN ISOLATED SHOWER OR THUNDERSTORM IS POSSIBLE
MAINLY WEST OF NYC TERMINALS THIS AFTERNOON. HOWEVER...ACTIVITY
WOULD BE TOO ISOLATED TO INCLUDE IN THE FORECAST AT THIS TIME.
BRIEF SUB VFR CONDITIONS ARE POSSIBLE IN ANY SHOWER OR TSTM.
SOUTHWEST WINDS 10 KTS OR LESS THIS MORNING WILL BECOME SOUTH 10 TO
15 KTS THIS AFTERNOON. A FEW GUSTS UP TO 20 KT ARE
POSSIBLE...HOWEVER GUSTS WILL NOT BE FREQUENT TO INCLUDE IN THE
FORECAST.
.OUTLOOK FOR 06Z SUN THROUGH WED...
.TONIGHT-MON...VFR WITH A CHANCE OF SHRA/TSTMS WITH MVFR OR LOWER
POSSIBLE.
.TUE-WED...VFR.
&&
.MARINE...
SOUTH/SOUTHWEST WINDS ARE FORECAST TODAY AND TONIGHT. THESE WINDS
INCREASE SUNDAY AND SUNDAY NIGHT OUT AHEAD OF LOW PRESSURE AND
ASSOCIATED COLD FRONT. SEAS BUILD AS A RESULT LATE SUNDAY THROUGH
SUNDAY NIGHT AND REMAIN RATHER ROUGH MONDAY. SMALL CRAFT ADVISORY
HEADLINES MAY BE NEEDED EVENTUALLY FOR THE SUNDAY NIGHT THROUGH
MONDAY TIME FRAME ACROSS THE OCEAN WATERS.
WINDS GRADUALLY SHIFT TO THE WEST BEHIND THE SLOW MOVING FRONT LATE
MONDAY AND MONDAY NIGHT...AND SPEEDS DIMINISH SOMEWHAT.
WEST OR NORTHWEST WINDS CAN BE EXPECTED TUESDAY AND WEDNESDAY.
ROUGH SEAS SUBSIDE TUESDAY AND WEDNESDAY.
&&
.HYDROLOGY...
UNSETTLED WEATHER WITH SCATTERED TO NUMEROUS SHOWERS/TSTMS ARE
FORECAST LATE TONIGHT THROUGH MONDAY. ANY OF THESE STORMS HAVE
THE POTENTIAL TO PRODUCE HEAVY DOWNPOURS. SIGNIFICANT UNCERTAINTY
STILL EXISTS WITH TIMING AND AMOUNTS THOUGH. IT LOOKS LIKE THE
HIGHER POTENTIAL FOR HEAVY RAIN IS SUNDAY AFTN AND SUNDAY NIGHT
WITH HIGHER PWATS OF 1.5 TO 2 INCHES ACROSS THE REGION.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1138 AM EDT SAT JUL 26 2014
.SYNOPSIS...
A NEARLY STATIONARY FRONTAL BOUNDARY OVER SOUTHERN SOUTH CAROLINA
WILL DISSIPATE THROUGH THE DAY. THUNDERSTORMS WILL BE ISOLATED
TODAY...WITH THE BEST CHANCE ACROSS EASTERN PORTIONS OF THE
REGION. WEAK UPPER LEVEL RIDGING WILL BRING CONTINUED HOT AND DRY
WEATHER SUNDAY. ANOTHER COLD FRONT WILL CROSS THE REGION LATE
MONDAY WITH A CHANCE OF THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
EARLIER AREAS OF FOG AND LOW CLOUDS HAVE DISSIPATED. CURRENT
MESOANALYIS INDICATES A DRY ATMOSPHERE OVER MOST OF THE FORECAST
AREA (FA)...WITH PRECIPITABLE WATER VALUES RANGING FROM 1.2 INCHES
NORTH TO 1.8 SOUTH. WEAK NVA PROJECTED FOR OUR FA TODAY AS WEAK
IMPULSE PUSHES TOWARDS THE COAST. MODEL FORECAST SOUNDINGS
DEPICTING A GENERALLY DRY AND CAPPED ATMOSPHERE FOR OUR FA. BEST
MOISTURE AND INSTABILITY TO OUR SOUTH...WHERE LATEST HRRR MODEL
GENERALLY RESTRICTS CONVECTIVE DEVELOPMENT THIS AFTERNOON MAINLY
SOUTH OF OUR FA. A FEW BRIEF SHALLOW LIGHT SHOWERS COULD POSSIBLY
DEVELOP THIS AFTERNOON ACROSS THE SE FA...BUT CHANCES APPEAR TOO
LOW TO INCLUDE IN THE FORECAST AT THIS TIME.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH SUNDAY NIGHT/...
TONIGHT...ONE UPPER TROUGH MOVES OFF THE EAST COAST
TONIGHT...WITH ANOTHER ONE BEGINNING TO DIG SOUTHWARD OUT OF THE
UPPER MIDWEST. THIS GENERALLY PUTS THE REGION UNDER A FLAT RIDGE
SATURDAY NIGHT. THIS SHOULD KEEP THINGS DRY. OVERNIGHT LOWS WILL
BE IN THE LOWER TO MIDDLE 70S.
FOR SUNDAY...UPPER TROUGH CONTINUES DIGGING ON THE EAST SIDE OF
THE LOWER MID-WEST UPPER RIDGE. THIS WILL CARVE OUT A DEEPER EAST
COAST TROUGH INTO SUNDAY NIGHT. DRY CONDITIONS WILL CONTINUE
SUNDAY INTO SUNDAY NIGHT AHEAD OF THE APPROACHING TROUGH...MAINLY
DUE TO SOME DOWNSLOPE FLOW. THE DOWNSLOPING SHOULD ALSO HELP
TEMPERATURES TO CLIMB BACK INTO THE UPPER 90S DURING THE DAY
SUNDAY IN MANY AREAS. GOOD SOUTHWEST FLOW AHEAD OF THE NEXT FRONT
SUNDAY NIGHT SHOULD ALSO KEEP TEMPS UP...WITH READINGS IN THE
UPPER 70S.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
THE MAIN FRONT WILL PUSH INTO THE REGION MONDAY MORNING...AND
SHOULD MOVE JUST OFF TO THE SOUTH AND EAST OF THE AREA BY MONDAY
NIGHT. MONDAY SHOULD BE OUR BEST CHANCE FOR SEEING ANY
SHOWER/THUNDERSTORM ACTIVITY. EVEN SO...ANY RAINFALL SHOULD MOVE
THROUGH RATHER QUICKLY DUE TO THE FASTER MOVEMENT OF THIS SYSTEM.
THROUGH THE REMAINDER OF THE WORKWEEK...THE MODELS CONTINUE TO
SHOW A DEEP LONG WAVE PATTERN ALONG THE EASTERN HALF OF THE
COUNTRY...WITH A STRONG RIDGE IN THE WEST. THIS SHOULD KEEP
TEMPERATURES BELOW NORMAL FOR THIS TIME OF THE YEAR...WHICH SHOULD
RESULT IN SOME QUITE PLEASANT AFTERNOON TEMPERATURES. SURFACE
TROUGH MAY STALL OUT NEAR THE COAST THROUGH THE WEEK...WHICH WOULD
KEEP THE BEST CHANCE FOR RAINFALL CLOSER TO THE COAST...AND KEEP
MUCH OF THE FORECAST AREA GENERALLY DRY. MODELS DO BEGIN BRINGING
INCREASING MOISTURE TO THE REGION BY THE END OF THE WEEK DUE TO
THE DEVELOPMENT OF AN EASTERLY FLOW OFF THE ATLANTIC.
&&
.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
EARLIER FOG AND LOW CLOUDINESS HAS DISSIPATED. VFR EXPECTED TODAY.
WEAKENING FRONT AND BEST MOISTURE TO THE SOUTH AND EAST OF THE
TERMINALS TODAY.
EXTENDED AVIATION OUTLOOK...MINIMAL CONVECTION EXPECTED SUN.
BETTER THUNDERSTORM CHANCES MONDAY WITH APPROACHING COLD FRONT.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1123 AM EDT SAT JUL 26 2014
.SYNOPSIS...
ISSUED AT 1052 AM EDT SAT JUL 26 2014
SHOWER AND THUNDERSTORM CHANCES WILL OVERSPREAD THE REGION TODAY
AS A FRONT APPROACHES. THIS FRONT WILL REMAIN IN THE REGION
THROUGH TONIGHT KEEPING THE SHOWER AND THUNDERSTORM CHANCES
AROUND. HIGH TEMPERATURES TODAY WILL RANGE FROM THE LOWER 80S IN
SOUTHERN MICHIGAN TO THE UPPER 80S NEAR THE OHIO RIVER. LOW
TEMPERATURES TONIGHT WILL RANGE FROM THE UPPER 60S IN SOUTHERN
MICHIGAN TO THE LOWER 70S ALONG THE OHIO RIVER.
&&
.UPDATE...
ISSUED AT 946 AM EDT SAT JUL 26 2014
FORECAST INTO THIS AFTERNOON IN PRETTY GOOD SHAPE WITH ONLY SOME
MINOR CHANGES MADE. SLOWLY INTRODUCED LOW 15-20 POPS FOR ISOLATED
SHOWERS/THUNDER INTO NORTHERN/EASTERN ZONES THIS AFTERNOON GIVEN
WEAK WAA/ISENTROPIC ASCENT AND BOUNDARY LAYER HEATING IN ADVANCE
OF A WARM FRONT AND STOUT (IA/NRN MO/WS IL) EML. THIS EML APPEARS
RATHER IMPRESSIVE ON 12Z DVN/ILX/OMX RAOBS WITH CONVECTIVE TEMPS
IN EXCESS OF 100F. THIS MAY DELAY PRIMARY CONVECTIVE COMPLEX
PROGGED TO POSSIBLY CLIP OUR SOUTHERN ZONES TO LATER TONIGHT WHEN
HEIGHT FALLS BEGIN TO OVERSPREAD THE FRONTAL BOUNDARY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 451 AM EDT SAT JUL 26 2014
NOSE OF LOW LEVEL JET FOCUS COINCIDENT WITH EASTERN PERIPHERY OF
STOUT EML BEGINNING TO DRIVE CONVECTIVE DEVELOPMENT UPSTREAM IN ARC
STRETCHING FROM EASTERN IA-NWRN IL-FAR WCNTL IN. VEERING JETLET AND
STEERING FLOW SUGGESTS MAJORITY OF SHRA TO TARGET ONLY FAR SWRN/SRN
CWA THIS AM. LACK OF APPRECIABLE LOW LEVEL MOISTURE WITH EASTERN
EXTENT SHOULD PRECLUDE ALL BUT PERHAPS AN ISOLD TSRA WITH EASTERN
EXTENT INTO CWA. SMALL CHC TSRA POPS IN DEFERENCE TO SHORT MODEL
CONSENSUS AFFORDED ACROSS ERN CWA THIS AFTN AS RIDGE OF GREATER
1000-850MB THETA-E/MOISTURE FLUX CONVERGENCE ASSERTS INTO NERN
IN/NWRN OH. DIFFERENTIAL HEATING ALONG DECAYING AM SHRA AND
STRATO/ALTOCU LAYERS AND PRESENCE OF DIFFUSE WARM FRONTAL LIMB LENDS
CREDENCE TO TREND OF OUTCOME/SOLUTIONS SEEN WITH 3KM HIGH-RES RAPID
REFRESH RUC IN THIS REGARD. WEAK LOW AMPLITUDE RIDGING SHOULD ALLOW
LOW END MENTION TO SUFFICE THROUGH TODAY. BY FAR THE GREATER
CONVECTIVE CONCERN LIES UPSTREAM AS EXTREME SERN SASK VORTEX DRIVES
SEWD INTO NRN MN EARLY TONIGHT WITH 60-70KT MID TROPOSPHERIC FLOW
ALONG SOUTHERN PERIPHERY OF WAVE. STRONG MID/UPPER LEVEL KINEMATICS
TO IMPINGE ON AREA OF SIGNIFICANT MOISTENING/HEATING BENEATH
RESIDUAL EML TO OFFER STRONG 3500-5000 J/KG SBCAPE BY 00 UTC SUN.
THIS LARGE INSTABILITY POOL PRESENTS ELONGATED E-W FROM SWRN CWA TO
MO/IA BORDER AMID 40-50 KTS DEEP LAYER BULK SHEAR. DECENT POTENTIAL
FOR MULTIPLE EPISODIC EVENING/EARLY NIGHT SUPERCELLS TO DEVELOP
UPSTREAM ACROSS CENTRAL/NCENTRAL ILLINOIS TO TRACK INTO SRN HALF OF
CWA AND TRANSITION TOWARD STRONG/SEVERE QUASI-LINEAR SEGMENTS
THROUGH SOUTHERN HALF OF CWA IN STRONG PARALLEL STORM MOTION
VECTORING. MDPI GT 1 AND DECENT /1000-1250 J/KG/ CAPE WITHIN
M10-M30C HAIL PRODUCTION ZONE WITH FAVORABLE WETBULB ZERO HEIGHTS IN
10.5-11.5 RANGE SUGGESTIVE OF MULTIPLE DAMAGING WIND EVENTS/ISOLATED
LARGE HAIL RISKS. DIFFICULTY IN SHARP DEMARCATION OF POPS WITH
EXTREMELY SHARP INSTABILITY GRADIENT WITH ONLY SLIGHT CHC MENTION
WARRANTED FAR NRN CWA RAMPING TO SIGNIFICANT/SEVERE LIKELY
POPS/SEVERE MENTION GENERALLY ALONG/S OF ROUTE 30 IN 00-09 UTC
TIMEFRAME. SOME CONCERN FOR POTENTIAL BACKBUILDING/TRAILING
STRATIFORM CONVECTION IN 06-12 UTC TIMEFRAME AS STORM MOTION VECTORS
BACK DUE WESTERLY...ALONG/PARALLEL TO TRAILING POOL OF EXTREME
1000-850MB MIXING RATIO GTE 16 G/KG THAT REACHES BACK INTO WEST
CENTRAL IL. WILL ADDRESS TERTIARY FLOODING POTENTIAL IN HWO IN
ADDITION TO DMG WIND/HAIL CONCERNS.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 451 AM EDT SAT JUL 26 2014
A WELL DEFINED UPPER LEVEL DISTURBANCE OVER SOUTHERN SASKATCHEWAN
PROVENCE EARLY THIS MORNING WILL MOVE SOUTHEAST DOWN THE BACKSIDE OF
THE UPPER LEVEL RIDGE. AS THIS SYSTEM MOVES SOUTHEAST TOWARD THE
WESTERN GREAT LAKES REGION...VERY UNSTABLE AIR WILL EXTEND INTO
NORTHERN INDIANA AND NORTHWEST OHIO EARLY SUNDAY MORNING. HIGH
ENERGY HELICITY INDEX VALUES UP TO 4.0 TO 5.0 M2/S2 REFLECT THE
POTENTIAL FOR SUPERCELL ACTIVITY OVER THE SOUTHERN THIRD OF THE
FORECAST AREA EARLY SUNDAY MORNING. SEVERE WEATHER CHANCES LOOK BEST
IN THE MORNING OVER FAR SOUTH AND SOUTHEAST AREAS. CONCERN FOR
MAINLY DAMAGING WINDS EARLY GIVEN A FAVORABLE WIND PROFILE
SIGNATURE. SEVERE WEATHER CHANCES SHOULD DIMINISH BY EARLY AFTERNOON
AS COOLER AIR SPREADS OVER THE AREA BEHIND THE FRONT. FOR THE REST
OF THE PERIOD...SOME LINGERING SHOWERS ARE POSSIBLE TONIGHT AND
MONDAY AS A POST FRONTAL TROF MOVES ACROSS THE AREA. KEPT THE REST
OF THE PERIOD DRY AS THE UPPER LEVEL TROF REMAINS OVER THE AREA. 500
MB ANALOGS SUPPORT TEMPERATURES BELOW NORMAL THIS UPCOMING WORK WEEK
WITH A PERSISTENT NEGATIVE HEIGHT ANOMALY SOUTH OF HUDSON BAY.
PREFER THE COOLER GFS/MEAN/MEX VALUES GIVEN COOL 850 MB TEMPERATURES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 652 AM EDT SAT JUL 26 2014
AS UPSTREAM LOWER LEVEL JET VEERS SUSPECT NERN IL INTO WCNTL IN
SHRA/ISOLD TSRA TO WEAKEN WITH EWD PROGRESSION THIS MORNING. BETTER
CHANCES FOR CONVECTIVE DEVELOPMENT CONTINUE TO APPEAR JUST AFTER
DARK AS KS FRONTAL WAVE LIFTS INTO CNTL IL AMID LARGE/EXTREME
3500-5000 J/KG SBCAPE POOL. MINOR ADJUSTMENTS TO TEMPO TSRA
TIMING.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
UPDATE...STEINWEDEL
SYNOPSIS...LOTHAMER
SHORT TERM...MURPHY
LONG TERM...SKIPPER
AVIATION...MURPHY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
946 AM EDT SAT JUL 26 2014
.SYNOPSIS...
ISSUED AT 655 AM EDT SAT JUL 26 2014
PERIODIC CHANCES FOR SHOWERS AND THUNDERSTORMS LATER TONIGHT AND
SUNDAY AS A FRONTAL BOUNDARY SETTLES INTO THE REGION. HIGHS ARE
EXPECTED TO REACH THE 80S TODAY AND SUNDAY. MUCH COOLER WEATHER
WILL RETURN EARLY NEXT WEEK AS AN UPPER TROUGH SETTLES IN.
&&
.UPDATE...
ISSUED AT 946 AM EDT SAT JUL 26 2014
FORECAST INTO THIS AFTERNOON IN PRETTY GOOD SHAPE WITH ONLY SOME
MINOR CHANGES MADE. SLOWLY INTRODUCED LOW 15-20 POPS FOR ISOLATED
SHOWERS/THUNDER INTO NORTHERN/EASTERN ZONES THIS AFTERNOON GIVEN
WEAK WAA/ISENTROPIC ASCENT AND BOUNDARY LAYER HEATING IN ADVANCE
OF A WARM FRONT AND STOUT (IA/NRN MO/WS IL) EML. THIS EML APPEARS
RATHER IMPRESSIVE ON 12Z DVN/ILX/OMX RAOBS WITH CONVECTIVE TEMPS
IN EXCESS OF 100F. THIS MAY DELAY PRIMARY CONVECTIVE COMPLEX
PROGGED TO POSSIBLY CLIP OUR SOUTHERN ZONES TO LATER TONIGHT WHEN
HEIGHT FALLS BEGIN TO OVERSPREAD THE FRONTAL BOUNDARY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 451 AM EDT SAT JUL 26 2014
NOSE OF LOW LEVEL JET FOCUS COINCIDENT WITH EASTERN PERIPHERY OF
STOUT EML BEGINNING TO DRIVE CONVECTIVE DEVELOPMENT UPSTREAM IN ARC
STRETCHING FROM EASTERN IA-NWRN IL-FAR WCNTL IN. VEERING JETLET AND
STEERING FLOW SUGGESTS MAJORITY OF SHRA TO TARGET ONLY FAR SWRN/SRN
CWA THIS AM. LACK OF APPRECIABLE LOW LEVEL MOISTURE WITH EASTERN
EXTENT SHOULD PRECLUDE ALL BUT PERHAPS AN ISOLD TSRA WITH EASTERN
EXTENT INTO CWA. SMALL CHC TSRA POPS IN DEFERENCE TO SHORT MODEL
CONSENSUS AFFORDED ACROSS ERN CWA THIS AFTN AS RIDGE OF GREATER
1000-850MB THETA-E/MOISTURE FLUX CONVERGENCE ASSERTS INTO NERN
IN/NWRN OH. DIFFERENTIAL HEATING ALONG DECAYING AM SHRA AND
STRATO/ALTOCU LAYERS AND PRESENCE OF DIFFUSE WARM FRONTAL LIMB LENDS
CREDENCE TO TREND OF OUTCOME/SOLUTIONS SEEN WITH 3KM HIGH-RES RAPID
REFRESH RUC IN THIS REGARD. WEAK LOW AMPLITUDE RIDGING SHOULD ALLOW
LOW END MENTION TO SUFFICE THROUGH TODAY. BY FAR THE GREATER
CONVECTIVE CONCERN LIES UPSTREAM AS EXTREME SERN SASK VORTEX DRIVES
SEWD INTO NRN MN EARLY TONIGHT WITH 60-70KT MID TROPOSPHERIC FLOW
ALONG SOUTHERN PERIPHERY OF WAVE. STRONG MID/UPPER LEVEL KINEMATICS
TO IMPINGE ON AREA OF SIGNIFICANT MOISTENING/HEATING BENEATH
RESIDUAL EML TO OFFER STRONG 3500-5000 J/KG SBCAPE BY 00 UTC SUN.
THIS LARGE INSTABILITY POOL PRESENTS ELONGATED E-W FROM SWRN CWA TO
MO/IA BORDER AMID 40-50 KTS DEEP LAYER BULK SHEAR. DECENT POTENTIAL
FOR MULTIPLE EPISODIC EVENING/EARLY NIGHT SUPERCELLS TO DEVELOP
UPSTREAM ACROSS CENTRAL/NCENTRAL ILLINOIS TO TRACK INTO SRN HALF OF
CWA AND TRANSITION TOWARD STRONG/SEVERE QUASI-LINEAR SEGMENTS
THROUGH SOUTHERN HALF OF CWA IN STRONG PARALLEL STORM MOTION
VECTORING. MDPI GT 1 AND DECENT /1000-1250 J/KG/ CAPE WITHIN
M10-M30C HAIL PRODUCTION ZONE WITH FAVORABLE WETBULB ZERO HEIGHTS IN
10.5-11.5 RANGE SUGGESTIVE OF MULTIPLE DAMAGING WIND EVENTS/ISOLATED
LARGE HAIL RISKS. DIFFICULTY IN SHARP DEMARCATION OF POPS WITH
EXTREMELY SHARP INSTABILITY GRADIENT WITH ONLY SLIGHT CHC MENTION
WARRANTED FAR NRN CWA RAMPING TO SIGNIFICANT/SEVERE LIKELY
POPS/SEVERE MENTION GENERALLY ALONG/S OF ROUTE 30 IN 00-09 UTC
TIMEFRAME. SOME CONCERN FOR POTENTIAL BACKBUILDING/TRAILING
STRATIFORM CONVECTION IN 06-12 UTC TIMEFRAME AS STORM MOTION VECTORS
BACK DUE WESTERLY...ALONG/PARALLEL TO TRAILING POOL OF EXTREME
1000-850MB MIXING RATIO GTE 16 G/KG THAT REACHES BACK INTO WEST
CENTRAL IL. WILL ADDRESS TERTIARY FLOODING POTENTIAL IN HWO IN
ADDITION TO DMG WIND/HAIL CONCERNS.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 451 AM EDT SAT JUL 26 2014
A WELL DEFINED UPPER LEVEL DISTURBANCE OVER SOUTHERN SASKATCHEWAN
PROVENCE EARLY THIS MORNING WILL MOVE SOUTHEAST DOWN THE BACKSIDE OF
THE UPPER LEVEL RIDGE. AS THIS SYSTEM MOVES SOUTHEAST TOWARD THE
WESTERN GREAT LAKES REGION...VERY UNSTABLE AIR WILL EXTEND INTO
NORTHERN INDIANA AND NORTHWEST OHIO EARLY SUNDAY MORNING. HIGH
ENERGY HELICITY INDEX VALUES UP TO 4.0 TO 5.0 M2/S2 REFLECT THE
POTENTIAL FOR SUPERCELL ACTIVITY OVER THE SOUTHERN THIRD OF THE
FORECAST AREA EARLY SUNDAY MORNING. SEVERE WEATHER CHANCES LOOK BEST
IN THE MORNING OVER FAR SOUTH AND SOUTHEAST AREAS. CONCERN FOR
MAINLY DAMAGING WINDS EARLY GIVEN A FAVORABLE WIND PROFILE
SIGNATURE. SEVERE WEATHER CHANCES SHOULD DIMINISH BY EARLY AFTERNOON
AS COOLER AIR SPREADS OVER THE AREA BEHIND THE FRONT. FOR THE REST
OF THE PERIOD...SOME LINGERING SHOWERS ARE POSSIBLE TONIGHT AND
MONDAY AS A POST FRONTAL TROF MOVES ACROSS THE AREA. KEPT THE REST
OF THE PERIOD DRY AS THE UPPER LEVEL TROF REMAINS OVER THE AREA. 500
MB ANALOGS SUPPORT TEMPERATURES BELOW NORMAL THIS UPCOMING WORK WEEK
WITH A PERSISTENT NEGATIVE HEIGHT ANOMALY SOUTH OF HUDSON BAY.
PREFER THE COOLER GFS/MEAN/MEX VALUES GIVEN COOL 850 MB TEMPERATURES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 652 AM EDT SAT JUL 26 2014
AS UPSTREAM LOWER LEVEL JET VEERS SUSPECT NERN IL INTO WCNTL IN
SHRA/ISOLD TSRA TO WEAKEN WITH EWD PROGRESSION THIS MORNING. BETTER
CHANCES FOR CONVECTIVE DEVELOPMENT CONTINUE TO APPEAR JUST AFTER
DARK AS KS FRONTAL WAVE LIFTS INTO CNTL IL AMID LARGE/EXTREME
3500-5000 J/KG SBCAPE POOL. MINOR ADJUSTMENTS TO TEMPO TSRA
TIMING.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
UPDATE...STEINWEDEL
SYNOPSIS...MURPHY
SHORT TERM...MURPHY
LONG TERM...SKIPPER
AVIATION...MURPHY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
655 AM EDT SAT JUL 26 2014
.SYNOPSIS...
ISSUED AT 655 AM EDT SAT JUL 26 2014
PERIODIC CHANCES FOR SHOWERS AND THUNDERSTORMS LATER TONIGHT AND
SUNDAY AS A FRONTAL BOUNDARY SETTLES INTO THE REGION. HIGHS ARE
EXPECTED TO REACH THE 80S TODAY AND SUNDAY. MUCH COOLER WEATHER
WILL RETURN EARLY NEXT WEEK AS AN UPPER TROUGH SETTLES IN.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 451 AM EDT SAT JUL 26 2014
NOSE OF LOW LEVEL JET FOCUS COINCIDENT WITH EASTERN PERIPHERY OF
STOUT EML BEGINNING TO DRIVE CONVECTIVE DEVELOPMENT UPSTREAM IN ARC
STRETCHING FROM EASTERN IA-NWRN IL-FAR WCNTL IN. VEERING JETLET AND
STEERING FLOW SUGGESTS MAJORITY OF SHRA TO TARGET ONLY FAR SWRN/SRN
CWA THIS AM. LACK OF APPRECIABLE LOW LEVEL MOISTURE WITH EASTERN
EXTENT SHOULD PRECLUDE ALL BUT PERHAPS AN ISOLD TSRA WITH EASTERN
EXTENT INTO CWA. SMALL CHC TSRA POPS IN DEFERENCE TO SHORT MODEL
CONSENSUS AFFORDED ACROSS ERN CWA THIS AFTN AS RIDGE OF GREATER
1000-850MB THETA-E/MOISTURE FLUX CONVERGENCE ASSERTS INTO NERN
IN/NWRN OH. DIFFERENTIAL HEATING ALONG DECAYING AM SHRA AND
STRATO/ALTOCU LAYERS AND PRESENCE OF DIFFUSE WARM FRONTAL LIMB LENDS
CREDENCE TO TREND OF OUTCOME/SOLUTIONS SEEN WITH 3KM HIGH-RES RAPID
REFRESH RUC IN THIS REGARD. WEAK LOW AMPLITUDE RIDGING SHOULD ALLOW
LOW END MENTION TO SUFFICE THROUGH TODAY. BY FAR THE GREATER
CONVECTIVE CONCERN LIES UPSTREAM AS EXTREME SERN SASK VORTEX DRIVES
SEWD INTO NRN MN EARLY TONIGHT WITH 60-70KT MID TROPOSPHERIC FLOW
ALONG SOUTHERN PERIPHERY OF WAVE. STRONG MID/UPPER LEVEL KINEMATICS
TO IMPINGE ON AREA OF SIGNIFICANT MOISTENING/HEATING BENEATH
RESIDUAL EML TO OFFER STRONG 3500-5000 J/KG SBCAPE BY 00 UTC SUN.
THIS LARGE INSTABILITY POOL PRESENTS ELONGATED E-W FROM SWRN CWA TO
MO/IA BORDER AMID 40-50 KTS DEEP LAYER BULK SHEAR. DECENT POTENTIAL
FOR MULTIPLE EPISODIC EVENING/EARLY NIGHT SUPERCELLS TO DEVELOP
UPSTREAM ACROSS CENTRAL/NCENTRAL ILLINOIS TO TRACK INTO SRN HALF OF
CWA AND TRANSITION TOWARD STRONG/SEVERE QUASI-LINEAR SEGMENTS
THROUGH SOUTHERN HALF OF CWA IN STRONG PARALLEL STORM MOTION
VECTORING. MDPI GT 1 AND DECENT /1000-1250 J/KG/ CAPE WITHIN
M10-M30C HAIL PRODUCTION ZONE WITH FAVORABLE WETBULB ZERO HEIGHTS IN
10.5-11.5 RANGE SUGGESTIVE OF MULTIPLE DAMAGING WIND EVENTS/ISOLATED
LARGE HAIL RISKS. DIFFICULTY IN SHARP DEMARCATION OF POPS WITH
EXTREMELY SHARP INSTABILITY GRADIENT WITH ONLY SLIGHT CHC MENTION
WARRANTED FAR NRN CWA RAMPING TO SIGNIFICANT/SEVERE LIKELY
POPS/SEVERE MENTION GENERALLY ALONG/S OF ROUTE 30 IN 00-09 UTC
TIMEFRAME. SOME CONCERN FOR POTENTIAL BACKBUILDING/TRAILING
STRATIFORM CONVECTION IN 06-12 UTC TIMEFRAME AS STORM MOTION VECTORS
BACK DUE WESTERLY...ALONG/PARALLEL TO TRAILING POOL OF EXTREME
1000-850MB MIXING RATIO GTE 16 G/KG THAT REACHES BACK INTO WEST
CENTRAL IL. WILL ADDRESS TERTIARY FLOODING POTENTIAL IN HWO IN
ADDITION TO DMG WIND/HAIL CONCERNS.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 451 AM EDT SAT JUL 26 2014
A WELL DEFINED UPPER LEVEL DISTURBANCE OVER SOUTHERN SASKATCHEWAN
PROVENCE EARLY THIS MORNING WILL MOVE SOUTHEAST DOWN THE BACKSIDE OF
THE UPPER LEVEL RIDGE. AS THIS SYSTEM MOVES SOUTHEAST TOWARD THE
WESTERN GREAT LAKES REGION...VERY UNSTABLE AIR WILL EXTEND INTO
NORTHERN INDIANA AND NORTHWEST OHIO EARLY SUNDAY MORNING. HIGH
ENERGY HELICITY INDEX VALUES UP TO 4.0 TO 5.0 M2/S2 REFLECT THE
POTENTIAL FOR SUPERCELL ACTIVITY OVER THE SOUTHERN THIRD OF THE
FORECAST AREA EARLY SUNDAY MORNING. SEVERE WEATHER CHANCES LOOK BEST
IN THE MORNING OVER FAR SOUTH AND SOUTHEAST AREAS. CONCERN FOR
MAINLY DAMAGING WINDS EARLY GIVEN A FAVORABLE WIND PROFILE
SIGNATURE. SEVERE WEATHER CHANCES SHOULD DIMINISH BY EARLY AFTERNOON
AS COOLER AIR SPREADS OVER THE AREA BEHIND THE FRONT. FOR THE REST
OF THE PERIOD...SOME LINGERING SHOWERS ARE POSSIBLE TONIGHT AND
MONDAY AS A POST FRONTAL TROF MOVES ACROSS THE AREA. KEPT THE REST
OF THE PERIOD DRY AS THE UPPER LEVEL TROF REMAINS OVER THE AREA. 500
MB ANALOGS SUPPORT TEMPERATURES BELOW NORMAL THIS UPCOMING WORK WEEK
WITH A PERSISTENT NEGATIVE HEIGHT ANOMALY SOUTH OF HUDSON BAY.
PREFER THE COOLER GFS/MEAN/MEX VALUES GIVEN COOL 850 MB TEMPERATURES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 652 AM EDT SAT JUL 26 2014
AS UPSTREAM LOWER LEVEL JET VEERS SUSPECT NERN IL INTO WCNTL IN
SHRA/ISOLD TSRA TO WEAKEN WITH EWD PROGRESSION THIS MORNING. BETTER
CHANCES FOR CONVECTIVE DEVELOPMENT CONTINUE TO APPEAR JUST AFTER
DARK AS KS FRONTAL WAVE LIFTS INTO CNTL IL AMID LARGE/EXTREME
3500-5000 J/KG SBCAPE POOL. MINOR ADJUSTMENTS TO TEMPO TSRA
TIMING.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...MURPHY
SHORT TERM...MURPHY
LONG TERM...SKIPPER
AVIATION...MURPHY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
841 AM CDT SAT JUL 26 2014
.UPDATE...
ISSUED AT 837 AM CDT SAT JUL 26 2014
RADAR SHOWS RETURNS MOVING INTO THE AREA THAT ARE WEAKENING WITH
TIME BUT NO REPORTS OF ANYTHING REACHING THE GROUND. SATELLITE
INDICATES PLENTY OF ACCAS AND RAP TRENDS INDICATES THE FORCING
WEAKENING OVER TIME. ADD TO THAT THE MORNING SOUNDING BEING QUITE
DRY ABOVE 800MB BRINGS DOUBTS ABOUT PRECIP CHANCES DURING THE
MORNING HOURS. OTHER THAN POSSIBLY SOME SPRINKLES...THE MORNING
PERIOD LOOKS TO BE DRY.
UPDATE ISSUED AT 745 AM CDT SAT JUL 26 2014
ADDED ISOLATED SHOWERS TO THE GRIDS THIS MORNING AS A FEW SHOWERS
IN CENTRAL IA WERE HEADED EAST INTO THE CWA. OTHERWISE NO CHANGES
TO THE GRIDS PLANNED. WE WILL BE DOING AN 18Z SPECIAL BALLOON
LAUNCH FOR THE SEVERE RISK.
&&
.SYNOPSIS...
ISSUED AT 350 AM CDT SAT JUL 26 2014
ISOLATED SHOWERS DEVELOPED AFTER MIDNIGHT IN OUR NORTHERN AND
EASTERN CWA ON THE NOSE OF A 35-40 KNOT LOW LEVEL JET. THERE IS
LOW LEVEL CONVERGENCE AND THETA-E ADVECTION BUT MOISTURE IS RATHER
LIMITED WHICH IS PREVENTING A MORE WIDESPREAD EVENT. THESE SHOWERS ARE
ALSO OCCURRING NORTHEAST OF A WARM FRONT WHICH EXTENDED ACROSS SOUTHEAST
IA AND INTO NORTHEAST ARKANSAS. 3 AM TEMPERATURES RANGED FROM THE
MID 60S TO AROUND 70 WITH DEWPOINTS RANGING FROM THE UPPER 50S IN
NW IL TO THE LOWER 70S IN WESTERN MO. EXTENSIVE LOW STRATUS WAS NOTED
NORTHEAST OF THE WARM FRONT AND COVERED MUCH OF OUR NORTHEAST HALF
OF THE CWA. SKIES WERE CLEAR TO PARTLY CLOUDY IN OUR SW CWA.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM CDT SAT JUL 26 2014
FORECAST FOCUS ON SEVERE/FLASH FLOODING POTENTIAL AND TEMPERATURES.
TODAY...ANY SHOWERS IN OUR EASTERN CWA WILL HAVE SHIFTED EAST OF
THE CWA BEFORE 6 AM SO WE WILL HAVE A DRY MORNING. LAMP DATA
SUGGESTS THE STRATUS WILL LINGER ACROSS OUR NORTHEAST CWA THROUGH
MUCH OF THE MORNING WITH THE LOW CLOUDS THEN BECOMING SCATTERED.
IN OUR SOUTHERN CWA THERE WILL BE PLENTY OF SUNSHINE SOUTH OF THE
WARM FRONT...WHICH SHOULD ADVANCE TO NEAR INTERSTATE 80 OR SO TODAY.
THIS WILL SET UP A NICE THERMAL GRADIENT WITH MAXIMUM TEMPERATURES
ALONG HIGHWAY 20 CLOSE TO 80 WHILE IN OUR FAR SOUTH READINGS SHOULD
PUSH TO AROUND 90. WITH DEWPOINTS IN OUR SOUTH RISING INTO THE
LOWER TO MID 70S HEAT INDEX VALUES WILL SOAR WELL INTO THE 90S TO
NEAR 100. TEMPERATURES WILL NEED TO BE MONITORED CLOSELY TODAY AS
CLOUD COVER (OR LACK OF) WILL HAVE AN IMPACT ON THESE READINGS
JUST LIKE YESTERDAY...WHERE READINGS WERE NOT AS WARM AS I EXPECTED.
SEVERE WEATHER...SPC HAS A MODERATE RISK IN OUR 4 SE COUNTIES WITH
A SLIGHT AS FAR NORTH AS HIGHWAY 30. CLOSED UPPER LOW IN SOUTHERN
SASKATCHEWAN DIVES SOUTHEAST INTO NORTHERN MN INCREASING DIFFLUENCE
ACROSS THE MIDWEST AND LARGE SCALE ASCENT AS HEIGHT FALLS ARRIVE.
THE LOCATION OF THE SEVERE WEATHER AND GREATEST CONCENTRATION WILL
CERTAINLY DEPEND ON WHERE THE FRONTAL BOUNDARY WILL EXIST AND
AMOUNT OF INSTABILITY. THE NAM SEEMS TOO HIGH WITH DEWPOINTS AND
CAPES BUT NONETHELESS SBCAPES SHOULD EASILY REACH 4000 J/KG IN OUR
SOUTH. HOW FAR NORTH THE SEVERE THREAT IS REALIZED WILL ONCE AGAIN
DEPEND ON CLOUD COVER AND FRONTAL POSITION. MODELS INTENSIFY MID
LEVEL WINDS TO 50+ KNOTS WHICH WILL INCREASE DEEP LAYER SHEAR WITH
SUPERCELLS INITIALLY DEVELOPING LATER THIS AFTERNOON IN OUR SOUTH
AS THE CAP WEAKENS. LARGE HAIL AND DAMAGING WINDS WILL BE THE MAIN
THREAT BUT A TORNADO OR TWO IS POSSIBLE. EVENTUALLY THIS WILL
CONGEAL INTO AN ORGANIZED MCS WITH DAMAGING WINDS THE MAIN THREAT
THIS EVENING AS IT EVENTUALLY PUSHES WELL TO THE EAST OF THE CWA.
FOR NOW HAVE MENTIONED SEVERE WORDING IN THE GRIDS IN OUR SOUTHERN
CWA LATE THIS AFTERNOON INTO THE EVENING HOURS.
FLASH FLOODING...WILL NEED TO KEEP AN EYE ON THE POTENTIAL FOR
FLASH FLOODING ESPECIALLY IN OUR FAR SOUTHERN CWA WHERE 3 TO 5
INCHES OF RAIN FELL YESTERDAY. WITH HIGH PWAT`S AGAIN THIS AFTERNOON
AND EVENING THE POTENTIAL IS CERTAINLY THERE FOR TORRENTIAL RAIN IN
A SHORT TIME. SOME OF THE RIVERS ALSO SHOWED A RAPID RESPONSE TO
THIS HEAVY RAIN BUT ARE STILL BELOW FLOOD STAGE AT THIS TIME.
OVERNIGHT...A COLD FRONT WILL THEN PUSH ACROSS THE CWA OVERNIGHT
WITH MINIMUM TEMPERATURES RANGING FROM THE LOWER 60S NW TO THE
UPPER 60S SE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 350 AM CDT SAT JUL 26 2014
VIGOROUS COMPACT UPPER LOW IS SHOWN TO DIVE SOUTHEASTWARD THROUGH THE
GREAT LAKES ON SUNDAY. ATTENDANT COLD FRONT WILL BE SWEEPING THROUGH
CWA EARLY IN THE DAY FOLLOWED BY GUSTY NORTHWEST WINDS AND LOWERING
HUMIDITY. PCPN CHANCES THUS DIMINISHING WITH FASTER FRONTAL PASSAGE
AND ONSET OF SUBSEQUENT COOL...DRY ADVECTION... BUT STILL HELD ON TO
SMALL PCPN CHANCES FAR NORTH SUNDAY AFTERNOON AHEAD OF SAGGING SURFACE
TROUGH/WIND SHIFT OVER WI.
MON-FRI...MEDIUM RANGE MODELS AND ENSEMBLES IN GOOD AGREEMENT DEPICTING
HIGHLY AMPLIFIED UPPER AIR PATTERN WITH ANOMALOUSLY DEEP TROUGH
OVER THE EASTERN HALF OF THE CONUS AND A SHARP RIDGE /HEAT DOME/ OUT
WEST. THIS WILL KEEP AREA LOCKED IN NORTHWEST FLOW ALOFT RESULTING IN
NICE STRETCH OF WEATHER NEXT WEEK GENERALLY CHARACTERIZED BY VERY
COMFORTABLE CONDITIONS WITH LOWER HUMIDITY AND BELOW NORMAL TEMPS...AND
ALSO DRIER WITH LIMITED MEASURABLE RAIN PROSPECTS...WITH POSSIBILITY
OF A FEW PM SHOWERS MAINLY LATE WEEK AS AIRMASS BEGINS TO UNDERGO GRADUAL
MODIFICATION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 745 AM CDT SAT JUL 26 2014
CNL MVFR CIGS THIS MORNING NORTH OF INTERSTATE 80 OTHERWISE VFR
CONDS. THUNDERSTORMS SHOULD DEVELOP THIS AFTERNOON AND INTO THE
EVENING HOURS MAINLY SOUTH OF INTERSTATE 80. MVFR/OCNL IFR CONDS
IN THUNDERSTORMS. A WARM FRONT WILL PUSH TO NEAR I-80 TODAY.
SOUTHEAST TO SOUTH WINDS SOUTH OF I-80 WITH NORTH TO NORTHWEST TO
THE NORTH. A COLD FRONT ARRIVES TONIGHT WITH WINDS BECOMING
NORTHWEST OVER ALL THE TAF SITES.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...05
AVIATION...HAASE
AREA FORECAST DISCUSSION
NWS DES MOINES IA
628 AM CDT SAT JUL 26 2014
.SHORT TERM /TODAY/...
ISSUED AT 345 AM CDT SAT JUL 26 2014
RATHER COMPLEX FORECAST FOR TODAY AS CONFIDENCE OF EVOLUTION OF MESO
SCALE ONLY MODEST AT THIS TIME...BUT COULD BE AN RATHER ACTIVE
AFTERNOON AND EVENING OVER THE SOUTH. AFTER EARLY MORNING PATCHY FOG
POTENTIAL FOR SEVERE WEATHER THIS AFTERNOON FOR ABOUT THE SOUTHERN
HALF OF THE FORECAST AREA. EARLY THIS MORNING A SHORT WAVE OVER THE
SOUTHERN PLAINS AT H850 IS DRIVING WARM AIR AND RATHER HIGH MOISTURE
INTO IOWA AND SURROUNDING STATES. A LARGE POOL OF 15C DEW POINTS
EXTENDS FROM EASTERN KS... COVERING ALL OF IOWA AND NORTHERN MO AS
WELL AS EASTERN MN AND WESTERN WI. CLOUDS HAVE BEEN DEVELOPING AT
MID LEVELS OVER SOUTHERN IOWA IN RESPONSE TO THIS MOISTURE AND A
WEAK SFC BOUNDARY/ZONE OF H850 30KT LLJ MOVING ACROSS THE AREA. SO
FAR THERE IS TOO MUCH CIN TO REALLY LET ANYTHING GO AT THIS TIME.
NORTHWEST OF US A PRONOUNCED H700 SHORTWAVE CURRENTLY IN WY/MT WILL
SHIFT EAST SOUTHEAST TODAY. AHEAD OF IT A WEAKER WAVE IS PRODUCING A
SMALL AREA OF CONVECTION OVER EASTERN SOUTH DAKOTA ALONG A RATHER
MINOR TROUGH AT H850 THAT EXTENDS FROM SUPERIOR/DULUTH BACK
SOUTHWESTWARD TO HURON AND RAPID CITY. IT IS EXPECTED THAT THIS AREA
OF CONVECTION WILL WEAKEN AND CONTINUE TO MOVE SOUTHEAST AND IMPACT
NORTHERN PORTIONS OF THE FORECAST AREA THIS MORNING PRIOR TO NOON.
THE WESTERN EDGE OF THE CONVECTION THOUGH...IS EXPECTED TO INTENSIFY
BY LATE MORNING IN RESPONSE TO THE APPROACHING STRONGER H700 WAVE
AND H500 WESTERLIES INCREASING TO 50KTS BY 00Z AND H300 WINDS
NEARING 70 TO 85KTS BY 00Z OVER IOWA.
THIS MORNING A WEAK SFC LOW OVER SOUTHWEST IOWA WILL DRIFT SOUTHEAST
INTO NORTHERN MO DURING THE AFTERNOON HOURS. A PRONOUNCED 2500 TO
3500 J/KG MLCAPE MAX WILL BE OVER THE SOUTHERN TWO TIER COUNTIES BY
18Z...WITH HEATING INCREASING INSTABILITY TO 3500 J/KG NEAR DES
MOINES TO 5500 J/KG JUST SOUTH OF THE IA/MO BORDER. HRRR MODEL
SUGGESTS THAT A SMALL CLUSTER OF STORMS SHOULD BE ONGOING IN
NORTHEAST/EAST NEBRASKA WHILE THE NMM/ARW SUGGEST THAT THE
CONVECTION OVER NEBRASKA WILL DISSIPATE AND REDEVLOP OVER FAR
SOUTHERN IA/MO. HOPWRF ALSO SHOWS EASTERN NEBRASKA CONVECTION
CONTINUING TO INTENSIFY WITH TIME THIS AFTERNOON MOVING ESE. THIS IS
SUPPORTED BY THE MEAN AND FORWARD PROPAGATING CORFIDI VECTORS...WITH
TRANSLATION ABOUT 30 TO 40 KTS. WITH THE WEAK BOUNDARY OVER THE
IOWA/MISSOURI BORDER BY 00Z...ANY CONVECTION THAT DEVELOPS TO OUR
WEST WILL RAPIDLY INTENSIFY INTO THE AXIS OF HIGH CAPE THIS
AFTERNOON. GIVEN THE VARIOUS SOLUTIONS...AM LEANING TOWARD
CONVECTION DEVELOPING IN NORTHEAST/EAST NEBRASKA AND STRENGTHENING
RAPIDLY THIS AFTERNOON AS IT INTERACTS WITH THE MOISTURE POOL IN AND
NEAR IOWA TO THE SOUTH. HAVE INCREASED POP ACROSS THIS AREA TO
REFLECT THAT SCENARIO. THE SOUTH IS OUTLOOKED FOR A SLIGHT
RISK...LOOKS VERY REASONABLE WITH THE POTENTIAL OF A STRENGTHENING
FORWARD PROPAGATING CONVECTIVE COMPLEX NEAR/JUST NORTH OF THE
BOUNDARY LATER TODAY THROUGH EITHER SOUTHERN IOWA OR NORTHERN
MISSOURI. THERE WILL BE A POTENTIAL FOR HIGHER IMPACT CONVECTIVE
WINDS IF THE SYSTEM GETS STRONG ENOUGH PRIOR TO MOVING SOUTH/EAST OF
THE AREA THIS EVENING. PRECIPITABLE WATER INCREASES TO OVER TWO
INCHES SOUTH OF INTERSTATE 80 THIS AFTERNOON WITH WARM CLOUD DEPTHS
OF 13 TO 14KFT TODAY AS WELL. IN ANY STRONGER STORMS THAT DEVELOP...
A QUICK 1 TO +2 INCHES IS VERY POSSIBLE DESPITE THE PROJECTED FAST
MOVEMENT OF THE STORMS. HIGHS WILL AGAIN BE WARM SOUTH IN THE UPPER
80S TO NEAR 90 WITH LOWER TO MID 80S ACROSS THE NORTH. WINDS WILL
NOT BE APPRECIABLE STRONG AND GENERALLY OUT OF THE NORTHEAST.
.LONG TERM /TONIGHT THROUGH FRIDAY/...
ISSUED AT 345 AM CDT SAT JUL 26 2014
NEARLY ALL OF THE CONCERNS IN THIS PERIOD WILL BE EARLY ON...THIS
EVENING. THE AIRMASS WILL BE THERMODYNAMICALLY PRIMED DURING PEAK
HEATING WITH THE GFS/NAM SUGGESTING MLCAPES 4K J/KG OR GREATER AND
LITTLE CINH. ONLY QUESTION WILL BE WHETHER A TRIGGER MECHANISM WILL
BE IN PLACE AND THAT SEEMS TO BE LESS AND LESS OF A CONCERN
JUDGING FROM CURRENT UPSTREAM CONDITIONS. RAP OBJECTIVE ANALYSIS
AND WATER VAPOR LOOP SHOW SEVERAL SHORT WAVES/PV ANOMALIES
TOPPING THE SWRN CONUS RIDGE AND EMBEDDED IN THE SEASONALLY FAST
PACIFIC NW TO NRN PLAINS UPPER FLOW. THIS KINEMATIC FORCING IS
CURRENTLY DRIVING SMALL WRN KS AND SD CONVECTIVE CLUSTERS IN
AREAS OF WEAK THERMODYNAMIC SUPPORT. THUS EXPECT REMNANTS OF THESE
FEATURES AND ASSOCIATED FORCING TO BE TRAVERSING SRN IA/NRN MO
DURING PEAK HEATING IN THE VICINITY OF CURRENT SURFACE
FRONT...NOTED ALONG SRN ONE/TWO TIERS OF IA COUNTIES PER 07Z
ANALYSIS. OPERATIONAL AND HI RES MODELS SUGGEST CONVERGENCE
ASSOCIATED WITH THIS BOUNDARY WILL BE INTO MO BY 00Z...BUT
EXISTING CONVECTION FROM EARLIER IN THE DAY MAY ALSO BE IN PLACE
JUST NORTH OF THE BOUNDARY AS WELL AS MENTIONED IN SHORT TERM
DISCUSSION. ALTHOUGH THE SHALLOW SHEAR IS WEAK...THE DEEP SHEAR
SHOULD BE IN THE 50KT RANGE SUGGESTING ANYTHING THAT DOES NEWLY DEVELOP
COULD BE SUPERCELLULAR INITIALLY. ALTHOUGH THE 0-1KM KINEMATICS
ARE WEAK...THE DEGREE OF DEEP AND 0-3KM INSTABILITY MAY KEEP A FEW
THERMODYNAMICALLY DOMINATE TORNADOES IN THE PICTURE AS WELL...IN
ADDITION TO THE WIND AND HAIL THREAT AS SYSTEM EVOLVES AND LIKELY
BECOMES MORE LINEAR. WHATEVER DOES OCCUR WILL EITHER MOVE OUT OF
OUR FORECAST AREA QUICKLY...OR STAY INTO NRN MO SO OUR WINDOW WILL
BE BRIEF WITH DRY CONDITIONS OVERNIGHT.
COOLER TEMPERATURES WILL THEN BE THE PRIMARY WEATHER STORY INTO
EARLY NEXT WEEK. THERE IS LITTLE IN THE WAY OF FORCING OR WARM
ADVECTION RIGHT ON THROUGH THE EXTENDED...AND EITHER UNIFORM NW
SURFACE FLOW OR LIGHT AND VARIABLE WINDS SHOULD LEAD TO MINIMAL LOW
LEVEL CONVERGENCE. STEEP LAPSE RATES NEAR THE CORE OF THE CURRENT
SASKATCHEWAN AND EVENTUALLY WRN GREAT LAKES UPPER LOW MAY DEVELOP
SOME SHOWERS NE DURING PEAK HEATING SUN...BUT OTHERWISE HAVE EITHER
A DRY FORECAST OR ONLY SLIGHTS FOR THE REMAINDER OF THE FORECAST.
TEMPS STILL LOOK BELOW NORMAL WITH HIGHS OFTEN IN THE 70S AND NO
BETTER THAN THE LOW 80S. LOWS SHOULD OFTEN BE IN THE 50S OR LOWER
60S. ALTHOUGH UPPER LEVEL WINDS WILL EVENTUALLY DIMINISH WITH SOME
HEIGHT RISES...THE OVERALL PATTERN /MORE POSITIVE PNA/ WILL
CHANGE LITTLE INTO NEXT WEEKEND WITH WRN CONUS RIDGE/ERN TROUGH.
&&
.AVIATION...26/12Z
ISSUED AT 623 AM CDT SAT JUL 26 2014
PATCHY DENSE FOG WILL CONTINUE OVER THE AREA FOR THE NEXT 1 TO 2
HOURS. LIGHT SHOWERS/SPRINKLES HAVE DEVELOPED ACROSS THE AREA THIS
MORNING BUT THE MAIN CONCERN THIS AFTERNOON/EVENING SOUTH AS
STRONGER WINDS ALOFT COMBINE WITH A WAVE DROPPING SOUTHEAST INTO
THE STATE. THIS WILL CREATE AN AREA OF THUNDERSTORMS OVER
NORTHEAST NEBRASKA AND SHOULD MOVE SOUTHEAST DURING THE AFTERNOON
AND EVENING...AFFECTING MAINLY KDSM AND KOTM. SOME UNCERTAINTY
REMAINS REGARDING THE COVERAGE...SO HAVE NOT INCLUDED CATEGORICAL
FOR KDSM AT THIS TIME. POTENTIAL FOR QUICK HEAVY RAINS AND HIGH
WIND GUSTS IN STRONGER STORMS DUE TO HIGH INSTABILITY AND
PRECIPITABLE WATER ACROSS AREA THIS AFTERNOON. NEXT UPDATE AT 18Z
SHOULD HAVE BETTER CONFIDENCE/MORE DETAILS ON DEGREE OF IMPACT FOR
SOUTHERN TAF SITES. /REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...REV
LONG TERM...SMALL
AVIATION...REV
AREA FORECAST DISCUSSION
NWS CARIBOU ME
948 AM EDT SAT JUL 26 2014
.SYNOPSIS...
HIGH PRESSURE OVER THE MID ATLANTIC STATES WILL MOVE EAST TOWARD
THE OPEN ATLANTIC THIS AFTERNOON. LOW PRESSURE WILL APPROACH FROM
THE WEST TONIGHT THEN CROSS THE REGION SUNDAY INTO MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
935 AM UPDATE...ADJUSTMENTS WERE MADE TO THE SKY TO BRING SOME
MORE CLOUDINESS INTO REGION ESPECIALLY NORTHERN AND CENTRAL AREAS
AS THE LATEST VISIBLE SATELLITE IMAGERY SHOWED SOME THICKER CLOUDS
IN THE FORM OF CIRRUS MOVING INTO THESE REGIONS. THE PRECIP
CHANCES WERE ADJUSTED AS WELL(POPS) TO ACCOUNT FOR SOME LIGHT
SHOWERS POSSIBLE IN THE CENTRAL AREAS THIS AFTERNOON AS EVIDENCE
OF THE NAM12 AND RAP MODEL. DECIDED ON 20% FOR ISOLATED WORDING
FOR SHOWERS. THE INSTABILITY IN THE LLVLS IS NOT THE IMPRESSIVE
W/LIS NO LESS THAN -2 TO SBCAPES OF 300 TO PERHAPS 500 J/KG. THE
IS DECENT MID LEVEL LAPSE RATES OF 7.0+C/KM THIS AFTERNOON AND
SOME MOISTURE AVAILABLE FROM ABOUT 850-700MBS PER THE SOUNDINGS
THIS MORNING. AN ISOLATED TSTM IS POSSIBLE.
PREVIOUS DISCUSSION...
SURFACE HIGH PRESSURE WILL REMAIN TO OUR SOUTH TODAY WHILE AN
UPPER LEVEL LOW REMAINS CENTERED TO THE EAST OF HUDSON BAY CANADA.
ALL IN ALL ONE MORE FAIR WEATHER DAY CAN BE EXPECTED TODAY WITH
NEAR TO SLIGHTLY ABOVE NORMAL TEMPERATURES. THE ONLY FLY IN THE
OINTMENT WILL BE THE POTENTIAL FOR AN ISOLATED SHOWER LATE THIS
AFTERNOON INTO THIS EVENING AS A RESULT OF A WEAK UPPER
DISTURBANCE CROSSING THE REGION COMBINED WITH DAYTIME HEATING.
TONIGHT WILL SEE INCREASING CLOUDS AS THE NEXT MORE POTENT SHORT
WAVE BEGINS TO APPROACH THE REGION FROM THE WEST. THERE IS THE
CHANCE FOR A SHOWER LATE TONIGHT ALTHOUGH MOST OF THE NIGHT WILL BE
DRY. LOW TEMPERATURES TONIGHT WILL MAINLY BE IN THE MID TO UPPER 50S
ACROSS THE REGION.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
THE START OF THE WEEK LOOKS TO BE RAINY AS A LOW PRESSURE SYSTEM
MARCHES EAST FROM THE GREAT LAKES AND INTO SOUTHERN QUEBEC, AN
OCCLUDED FRONT IN TOW. THIS FRONT WILL SLOW DOWN AS IT APPROACHES
THE PINE TREE STATE AS A SERIES OF LOWS DEVELOPS ALONG IT. THE EXACT
TIMING AND PLACEMENT OF THE FRONT AND THE LOWS IS STILL UNCERTAIN,
BUT SHOWERS WILL BE LIKELY BOTH SUNDAY AND MONDAY, WITH PERHAPS A
BRIEF BREAK FROM THE RAIN SUNDAY NIGHT. THERE WILL BE SOME
INSTABILITY AROUND, SO CAN`T RULE OUT A FEW THUNDERSTORMS BOTH DAYS.
WITH PLENTY OF CLOUDS AROUND, BOTH DAYS WILL BE A BIT COOLER THAN
NORMAL; MOST SPOTS WILL BE IN THE LOWER 70S FOR DAYTIME HIGHS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
SHOWERS WILL CONTINUE TO BE POSSIBLE MONDAY NIGHT AND TUESDAY AS AN
OCCLUDED FRONT WILL CROSS THE REGION AT SOME POINT DURING THAT
TIMEFRAME; EXACTLY WHEN IS NOT WELL AGREED UPON BY THE LONGER RANGE
FORECAST MODELS. THEREAFTER, THE REGION LOOKS TO BE UNDER A VERY
NARROW RIDGE OF SURFACE HIGH PRESSURE. WHILE THIS WOULD ARGUE FOR
DRY WEATHER, THERE IS STILL THE POTENTIAL FOR SHOWERS AS WE WILL
REMAIN ON THE EASTERN SIDE OF AN UPPER LOW CENTERED NEAR HUDSON BAY.
HAVE GONE WITH SLIGHT CHANCE POPS FOR WEDNESDAY THROUGH FRIDAY TO
ACCOUNT FOR THE POTENTIAL FOR MAINLY AFTERNOON SHOWERS EACH DAY.
AFTER A COOL DOWN EARLY IN THE WEEK, WE`LL SEE A GRADUAL WARMING
TREND AS SOUTHWEST FLOW DEVELOPS ALOFT.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
NEAR TERM: MAINLY VFR THROUGH TONIGHT. HOWEVER...SOME PATCHY MVFR
IS POSSIBLE EARLY THIS MORNING IN HZ/BR.
SHORT TERM: MVFR CONDITIONS WITH LOCALIZED IFR CONDITIONS ARE
EXPECTED SUNDAY THROUGH MONDAY IN WIDESPREAD SHOWERS AND SCATTERED
THUNDERSTORMS. CONDITIONS COULD POSSIBLY IMPROVE BY TUESDAY,
THOUGH AT LEAST OCCASIONAL MVFR COULD STILL STRIKE IN SCATTERED
SHOWERS. VFR WILL RETURN WEDNESDAY AS HIGH PRESSURE TRIES TO TAKE
HOLD.
&&
.MARINE...
NEAR TERM: WINDS/SEAS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY
LEVELS THROUGH TONIGHT.
SHORT TERM: NO HEADLINES ARE ANTICIPATED THROUGH THE LAST HALF OF
THE WEEKEND. HOWEVER, SOUTH FLOW IS PROGGED TO INCREASE MONDAY
AHEAD OF AN APPROACHING FRONT. THIS WOULD ALLOW SEAS TO BUILD.
WHILE WNAWAVE LOOKS A BIT OVERDONE (8-10 FT), WAVES AROUND 6 FEET
SEEM REASONABLE. A SMALL CRAFT ADVISORY MAY BE NEEDED FOR MONDAY
AND MONDAY NIGHT.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DUDA/HEWITT
SHORT TERM...HASTINGS
LONG TERM...HASTINGS
AVIATION...DUDA/HEWITT/HASTINGS
MARINE...DUDA/HEWITT/HASTINGS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
643 AM CDT SAT JUL 26 2014
.UPDATED FOR 12Z AVIATION DISCUSSION...
ISSUED AT 629 AM CDT SAT JUL 26 2014
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 318 AM CDT SAT JUL 26 2014
EARLY MORNING WATER VAPOR IMAGERY WITH GFS26.00 500MB HEIGHTS AND
WINDS SHOWED A COMPACT UPPER LEVEL LOW IN SOUTHERN MANITOBA...AND
AN UPPER LEVEL RIDGE CENTERED OVER NORTHERN TEXAS. THIS LED TO QUICK
ZONAL FLOW OVER THE NORTHERN THIRD OF THE CONUS...WITH A WEAK
SHORTWAVE LOCATED OVER CENTRAL SOUTH DAKOTA. THIS SHORTWAVE WAS ABLE
TO FIRE OFF A FEW THUNDERSTORMS OVERNIGHT. THE LEADING EDGE OF THESE
STORMS WERE FALLING APART...AND THE LATEST RUNS OF THE HIRES
MODELS...INCLUDING THE HOPWRF AND HRRR SHOW THE DEVELOPING
CONVECTION DIVING SOUTHEAST OVER SOUTHWEST MINNESOTA AND NORTHERN
IOWA. THEREFORE HAVE INTRODUCED A SLIGHT CHANCE OF POPS ACROSS THE
FAR SOUTHWESTERN CWA.
LATER TODAY INSTABILITY WILL BUILD ALONG A WEAK SURFACE
TROUGH...WITH AN UPPER LEVEL WAVE DIVING DOWN FROM CANADA. THIS WILL
SUPPORT A FEW LATE AFTERNOON SHOWERS AND THUNDERSTORMS MAINLY ACROSS
NORTHERN MN AND WI. FORECAST SOUNDINGS SHOW CIN HOLDING OFF
CONVECTION EARLY IN THE AFTERNOON...WITH DEEP MIXING BY LATE
EVENING. INCREASED THE WINDS ACROSS WESTERN MN TO REFLECT THIS
BOUNDARY LAYER MIXING. CONTINUED PRECIP CHANCES ACROSS THE NORTHEAST
OVERNIGHT SATURDAY WITH COOLER DRIER AIR MOVING IN FROM THE
NORTHWEST.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 318 AM CDT SAT JUL 26 2014
THE UPPER LOW WILL ROTATE SOUTHEASTWARD ACROSS WESTERN WISCONSIN
SUNDAY. SCATTERED TO NUMEROUS SHOWER COVERAGE EXPECTED ACROSS ERN
MN AND WRN WI...WITH ISOLATED LIGHT SHOWERS OR SPRINKLES EXPECTED
FURTHER SOUTHWEST ACROSS WRN/SRN MN. REMOVED THE THUNDER MENTION
DUE TO POOR LAPSE RATES AND LITTLE OR NO INSTABILITY. THIS EVENT
WILL BE SIMILAR TO THE ONE ABOUT 2 WEEKS AGO...EXCEPT THAT THIS
ONE IS A BIT WEAKER AND AREAL COVERAGE OF PRECIP IS NOT EXPECTED
TO BE AS IMPRESSIVE.
CLEARING SKIES WILL FOLLOW SUNDAY NIGHT WHICH WILL MARK THE
BEGINNING OF A LONG STRETCH OF MOSTLY CLEAR SKIES AND SEASONAL OR
SLIGHTLY BELOW NORMAL TEMPERATURES. NOT MUCH TO DISCUSS BEYOND
SUNDAY...EACH DAY WILL MORE OR LESS BE A CARBON COPY OF THE LAST.
THE TROUGH WILL REMAIN PARKED OVER THE GREAT LAKES WITH RIDGING
ACROSS THE ROCKIES AND THE WESTERN ATLANTIC FOR THE NEXT WEEK OR
TWO. REMOVED POPS FOR LATE NEXT WEEK DUE TO VERY WEAK FORCING AND
LITTLE OR NO INSTABILITY. THINKING THE WIDESPREAD QPF OVER WI ON
THE GFS AND ECMWF IS MUCH OVERDONE AND IS LIKELY A RESULT OF AN
OVERESTIMATION OF EVAPOTRANSPIRATION...AND SUPERADIABATIC LAPSE
RATES AT THE SURFACE DUE TO WINDS LESS THAN 3 KT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 629 AM CDT SAT JUL 26 2014
LIFR FOG THAT HAD DEVELOPED ACROSS WESTERN MN EARLIER THIS MORNING
WAS GRADUALLY IMPROVING WITH THE DAYTIME HEATING. EXPECT VFR
CONDITION TO RETURN BY MID MORNING. LATER THIS AFTERNOON
INSTABILITY TOGETHER WITH FAVORABLE UPPER LEVELS SHOULD SUPPORT A
FEW WIDELY SCATTERED SHOWERS AND EVEN A THUNDERSTORM. AT THIS TIME
COVERAGE WILL BE TO SCARCE TO MENTION THUNDER IN THE TAFS. VFR
CONDITIONS SHOULD PREVAIL OVERNIGHT AS DRIER AIR MOVES ACROSS THE
REGION.
KMSP...
MVFR/LIFR FOG HAS DEVELOPED AT THE SITES SURROUNDING KMSP...BUT
EXPECT CONDITIONS TO IMPROVE AS THE MORNING PROGRESSES WITH VFR
CONDITIONS ANTICIPATED SHORTLY. A FEW HIGH BASED SHOWERS COULD
DEVELOP THIS AFTERNOON...BUT COVERAGE WILL BE SCARCE. A FEW
SHOWERS ARE POSSIBLE AGAIN ON SUNDAY.
/OUTLOOK FOR KMSP/
MON...VFR. WINDS N AT 5KTS.
TUE...VFR. WINDS N AT 10KTS.
WED...VFR. WINDS N AT 5KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JRB
LONG TERM...BORGHOFF
AVIATION...JRB
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1033 AM CDT Sat Jul 26 2014
.UPDATE...
Issued at 1033 AM CDT SAT JUL 26 2014
A MCV over northeastern Kansas is throwing a few wrinkles into the
going forecast. First, cloud cover is limiting how quickly we are
warming up so far this morning and with the bulk of the MCV yet to
track over the area it seems thicker cloud cover will persist through
much of today. This will continue to hold back temperatures through
at least early this afternoon. To account for this, have lowered
temperatures 2 to 3 degrees/ hr which resulted in about a 2 to 3
degree decrease in max temperatures. Dewpoints are tracking well but
with lower temperatures heat indices are now around 100 to as warm as
103.
The second concern is that this MCV will allow convection to
redevelop ahead of it. This is already occurring with isolated to
scattered showers and a few storms being triggered in the unstable
environment due to forcing from the MCV. Have increased or added
precipitation chances across mainly the northern two-thirds of the
forecast area to account for this. While there is ample instability
for this convection, shear is very weak at this point in time, so the
threat of severe weather is low.
The other item we`re watching is intense convection entering
northeastern Nebraska that is on a trajectory towards the forecast
area. This area seems to be mainly driven by a shortwave moving
around western ridge. It`s possible this area may move into northern
Missouri later this afternoon/early this evening. The question though
is if the stronger shear helping to sustain that convection can
build further south as well. The HRRR has started indicate this
system moving into the area but decreasing in strength. However
broader scale models and mesoanalysis show shear increasing across
northern Missouri so there appears to be some potential for either
the ongoing convection or new convection to develop across northern
Missouri and potentially become severe later this afternoon.
&&
.DISCUSSION...
Issued at 403 AM CDT SAT JUL 26 2014
The main weather concerns for this forecast package will reside in
the first 24 hours. The first of the concerns today will revolve
around the heat. The second concern will revolve around
precipitation chances late this afternoon into tonight and the
severe potential surrounding them.
Looking at 850mb temperature this morning and models continue to
range between 24C-28C. Providing we can mix up to that layer that
will yield highs in the 90s. However, there are a couple of caveats
(other than mixing) to this temperature forecast. The first is cloud
cover. There is a complex of thunderstorms currently heading east
across central Kansas. As this complex moves across central and into
eastern Kansas it is forecast to weaken as the LLJ veers. Of some
concern however is that some of the hi-res models such as the
HRRR/RAP hold it together long enough to move into our local area
providing from additional cloud cover. As such have lowered
temperatures a degree or two. However, heat indices should still
reside in the 102-107 range across the western CWA where a heat
advisory is in place from 1PM to 8PM. The second caveat will be the
potential for storms and what time they will initiate. The first
possibility is that one mentioned previously where thunderstorms
across Kansas move east and refire this afternoon. The second
scenario would be thunderstorms developing this evening along a cold
front which is currently extending from north central Iowa into
extreme northwestern Missouri and into northern Kansas. In either
scenario, strong instability will be in place with 2500-3500J/Kg of
CAPE will be available, along with steep mid level lapse rates, and
strong shear. As such storms that do develop will have the potential
to be severe with damaging winds and large hail being the primary
threats.
The cold front will be forced through the forecast area tonight as
an unseasonably strong upper trough moves from south central Canada
into the Upper Midwest. This will continue thunderstorm chances into
the night time hours.
By Sunday morning the front will shift south of the area. Northwest
flow aloft will bring cooler temperatures with highs in the 80s on
Sunday. A secondary cold front will move through the area on Sunday
night. This will bring another round of cooler July air to the area
Monday through Wednesday as the upper level flow remains out of the
northwest. Expect highs during this period to range from the upper
70s to lower 80s. Precipitation chances will increase on Thursday
and Friday as the medium range models depict the potential for upper
shortwaves moving through the area on continued northwest flow.
Precipitation during this timeframe as well as northwest flow will
keeps highs below normal in the low to mid 80s.
&&
.AVIATION...(For the 12Z TAFS through 12Z Sunday Morning)
Issued at 602 AM CDT SAT JUL 26 2014
VFR conds will continue the TAF period with sct-bkn high clouds
through the afternoon. The main concern for aviators will come this
evening as a cold front approaches and thunderstorms develop out
ahead of it. Models continue to develop thunderstorms east of the
terminals so have not included a VCTS mention in the TAF at this time
however did introduce sct cu btn 4-5kft this evening. The winds will
be out of the SW around 10kts at today becoming light and variable
this evening as the front approaches. FROPA will occur btn 03Z-05Z
with winds shifting to the north btn 5-10kts behind the front.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...HEAT ADVISORY until 8 PM CDT this evening FOR KSZ025-057-060-
102>105.
MO...HEAT ADVISORY until 8 PM CDT this evening FOR MOZ020-021-028-029-
037-043-053.
&&
$$
UPDATE...CDB
DISCUSSION...73
AVIATION...73
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1105 AM EDT SAT JUL 26 2014
.SYNOPSIS...A SURFACE TROUGH WILL DEVELOP OVER THE WESTERN PIEDMONT
THIS WEEKEND...RESULTING IN A VERY WARM SOUTHWEST FLOW. A STRONG
COLD FRONT WILL CROSS THE AREA ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1105 AM SATURDAY...
LINGERING LOW CLOUDS ACROSS OUR CENTRAL ZONES ARE SLOWLY LIFTING/
DISSIPATING WITH HEATING. THE 12Z GSO SOUNDING SHOWS THE LOW LEVEL
MOISTURE ASSOC WITH THE AFOREMENTIONED CLOUDS...HOWEVER ALSO NOTED A
DRY LAYER BETWEEN H6-H7 AND DRY ABOVE H5...ALONG WITH W-NW FLOW
THROUGHOUT MUCH OF THE SOUNDING. MODIFYING THE SOUNDING SUGGESTS THE
CURRENT LOW CLOUDS WILL TRANSLATE TO SHALLOW- TO PERHAPS SOME
MODERATE CU THIS AFTERNOON. HOWEVER...DRY AIR ALOFT AND SUBSIDENCE
IN THE WAKE OF THE DEPARTING SHORT WAVE SHOULD PRECLUDE ANY SHOWER
ACTIVITY THIS AFTERNOON. THE SOUNDING ALSO SUGGESTS HIGHS IN THE
UPPER 80S TO AROUND 90. CURRENT FORECAST IN GOOD SHAPE WITH NO
SIGNIF UPDATES THIS MORNING.
PREVIOUS NEAR TERM DISCUSSION AS OF 210 AM SATURDAY... SHEARED S/W
TROUGH AXIS WILL TRAVERSE THE AREA THIS MORNING... RESULTING IN
SCATTERED TO OCCASIONALLY BROKEN MID AND HIGH CLOUDS. SUBSIDENCE
WILL FOLLOW IN ITS WAKE...COINCIDENT WITH PEAK AFTERNOON
HEATING...WHICH SHOULD LARGELY SUPPRESS CONVECTIVE RAIN CHANCES
TODAY AS FORCING WILL OTHERWISE BE CONFINED TO VERY SHALLOW
CONVERGENCE ASSOCIATED WITH THE DEVELOPING PIEDMONT SFC TROUGH.
LOW-LEVEL THICKNESSES ARE PROGGED TO REBOUND 20M FROM YESTERDAY AND
DESPITE SOME MORNING CLOUDS FROM BOTH S/W MOVING THROUGH THE AREA
ALONG WITH SLOW LIFTING/DISSIPATION OF MORNING STRATUS/FOG
ANTICIPATE WE SHOULD REACH FULL SUN READINGS. HIGHS IN THE UPPER
80S/NEAR 90 NORTH TO LOWER 90S SOUTH. LOWS TONIGHT UNDER CLEAR SKIES
IN THE LOWER TO MID 70S.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 320 AM SATURDAY...
SUNDAY AND SUNDAY NIGHT:
A STRONG UPPER TROUGH OVER THE UPPER MS VALLEY SUNDAY MORNING WILL
TRACK SOUTHEASTWARD INTO THE OH VALLEY SUNDAY/SUNDAY NIGHT.
ACCOMPANYING SURFACE FRONT WILL APPROACH THE SOUTHERN APPALACHIANS
LATE SUNDAY NIGHT/MONDAY MORNING. IN THE MEAN TIME...PIEDMONT TROUGH
BISECTING THE AREA WILL BEGIN TO SHARPEN UP.
IN ADVANCE OF THE MAIN SHORTWAVE...CONVECTION...POSSIBLY A MCS IS
EXPECTED TO BE ONGOING OVER THE CENTRAL AND POSSIBLY SOUTHERN
APPALACHIANS EARLY SUNDAY. SOME STORMS COULD PERSIST INTO THE
AFTERNOON AS THEY MOVE EASTWARD INTO THE VIRGINIA PIEDMONT AND
COASTAL PLAIN. IF THIS CONVECTIN DOES INDEED HOLD TOGETHER...OUTFLOW
FROM THESE STORMS COULD SUPPORT A SLIGHT TO SMALL CHANCE OF STORMS
MAINLY ACROSS THE NORTH/NORTHEAST SUNDAY AFTERNOON AS HINTED BY THE
LATEST EC AND SOME OF THE CONVECTION ALLOWING MODELS. IF STORMS
DO DEVELOP...A MODIFIED EML LAYER CHARACTERIZED BY LAPSE RATES OF
7.25-7.50 COULD SUPPORT ISOLATED SEVERE STORM THAT COULD
LARGE HAIL. WILL RETAIN SLIGHT TO SMALL CHANCE POPS SUNDAY NIGHT
WITH BEST CHANCE IN PROXIMITY TO SURFACE FRONT TO OUR NW.
DEEP MIXING AND 850MB TEMPS IN EXCESS OF 21C WILL LEAD TO HIGHS IN
THE MID AND UPPER 90S. MIXING WILL DROP DEWPOINTS A
BIT...ESPECIALLY WEST OF THE PIEDMONT TROUGH...BUT TO THE EAST
DEWPOINTS ARE FORECAST TO REMAIN IN THE UPPER 60S TO AROUND 70. THE
RESULTING HEAT INDEX VALUES ARE IN THE 100-103. LOWS SUNDAY NIGHT
IN THE LOWER TO MID 70S.
MON/MON NIGHT: FOCUS ON MONDAY WILL BE THE LIKELIHOOD FOR SEVERE WEATHER AS A
STRONG COLD FRONT APPROACHES AND MOVES THROUGH THE AREA. THIS FRONT
WILL BE PROPELLED TOWARDS THE REGION AS A UNSEASONABLE STRONG UPPER
LEVEL TROUGH PUSHES EAST...WITH STRONG 40-60M HEIGHT FALLS EXPECTED
TO OVERSPREAD CENTRAL NC. THIS WILL COMBINE WITH THE EXPECTED STRONG
INSTABILITY (~1500-2000 J/KG MLCAPE) AND 40-50 KNOTS OF BULK SHEAR
TO PRODUCE SCATTERED SEVERE STORMS...WITH SUPERCELLS PROBABLE
CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING WINDS. ALTHOUGH
CONFIDENCE IS HIGH THAT THERE WILL BE SEVERE WEATHER ON MONDAY...
THERE ARE STILL SOME UNCERTAINTIES. DEEP WESTERLY FLOW MAY LIMIT
MOISTURE AND ULTIMATE COVERAGE...HOWEVER ANY STORM THAT DOES FORM
WILL LIKELY BE INTENSE. IN ADDITION...OUTFLOW BOUNDARIES AND DEBRIS
CLOUDINESS FROM CONVECTION SUNDAY NIGHT WILL HAVE AN IMPACT ON
CONVECTIVE DEVELOPMENT/LOCATION. REGARDLESS...AT THIS TIME...THE
BEST CHANCE FOR FOR PRECIP AND ULTIMATE SEVERE STORMS LOOKS TO BE
ACROSS THE EASTERN HALF OF THE FORECAST AREA (ALONG AND EAST OF THE
EXPECTED LOCATION OF THE LEE/PREFRONTAL TROUGH) AND POSSIBLY MORESO
ALONG AND EAST OF THE I-95 CORRIDOR WHERE ALL THE PARAMETERS WILL
LINE UP THE BEST. HIGH TEMPS ARE EXPECTED TO CLIMB INTO THE LOW TO
MID 90S AHEAD OF THE FRONT...WITH OVERNIGHT LOWS GENERALLY IN THE
MID TO UPPER 60S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...
UPPER LEVEL TROUGHING WILL STAY IN PLACE OVER THE EAST COAST
THROUGHOUT THE ENTIRE LONG TERM PERIOD PERIOD...WHILE AT THE SURFACE
COOL...CANADIAN HIGH PRESSURE WILL SETTLE OVER THE AREA. ALL OF THIS
WILL LEAD TO BELOW NORMAL TEMPS...WITH HIGHS GENERALLY IN THE
LOW/MID 80S AND OVERNIGHT LOWS IN THE LOW/MID 60S...POSSIBLY EVEN
SOME UPPER 50S IN THE NORMAL COOLER SPOTS. IN ADDITION... MOSTLY DRY
CONDITIONS ARE EXPECTED THROUGH THE END OF THE WEEK...ALTHOUGH WILL
SHOW A SLIGHT INCREASE IN PRECIP CHANCES BY FRIDAY AS MOISTURE
SLOWLY RETURNS.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 730 AM SATURDAY...
24-HR TAF PERIOD: RAP SOUNDINGS SUGGEST LIFR MORNING FOG/STRATUS
WILL LIFT AND DISPERSE TO MVFR AOA 14Z WITH VFR CONDITIONS RETURNING
BY 16Z. EXPECT MOSTLY DRY CONDITIONS TODAY WITH WINDS PREDOMINATELY
FROM THE SOUTHWEST AND LIGHT. THE PROBABILITY FOR FOG TONIGHT IS
LOW...LIKELY LIMITED FOG PRONE LOCATIONS SUCH AS KRWI.
LOOKING AHEAD: A COLD FRONT WILL APPROACH FROM THE NW SUNDAY/EARLY
NEXT WORK WEEK... BRINGING THE POTENTIAL FOR SHOWERS/STORMS AND SUB-
VFR CONDITIONS LATE SUNDAY (IN THE NORTHWEST) INTO MONDAY...
PARTICULARLY MONDAY (ESPECIALLY EAST). VFR CONDITIONS ARE EXPECTED
TO RETURN BEHIND THE FRONT ON TUESDAY AND CONTINUE THROUGH AT LEAST
MID WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...NP/CBL
SHORT TERM...CBL/KRD
LONG TERM...KRD
AVIATION...CBL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
730 AM EDT SAT JUL 26 2014
.SYNOPSIS...A SURFACE TROUGH WILL DEVELOP OVER THE WESTERN PIEDMONT
THIS WEEKEND...RESULTING IN A VERY WARM SOUTHWEST FLOW. A STRONG
COLD FRONT WILL CROSS THE AREA ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 210 AM SATURDAY...
SHEARED S/W TROUGH AXIS WILL TRAVERSE THE AREA THIS MORNING...
RESULTING IN SCATTERED TO OCCASIONALLY BROKEN MID AND HIGH CLOUDS.
SUBSIDENCE WILL FOLLOW IN ITS WAKE...COINCIDENT WITH PEAK AFTERNOON
HEATING...WHICH SHOULD LARGELY SUPPRESS CONVECTIVE RAIN CHANCES
TODAY AS FORCING WILL OTHERWISE BE CONFINED TO VERY SHALLOW
CONVERGENCE ASSOCIATED WITH THE DEVELOPING PIEDMONT SFC TROUGH.
LOW-LEVEL THICKNESSES ARE PROGGED TO REBOUND 20M FROM YESTERDAY AND
DESPITE SOME MORNING CLOUDS FROM BOTH S/W MOVING THROUGH THE AREA
ALONG WITH SLOW LIFTING/DISSIPATION OF MORNING STRATUS/FOG
ANTICIPATE WE SHOULD REACH FULL SUN READINGS. HIGHS IN THE UPPER
80S/NEAR 90 NORTH TO LOWER 90S SOUTH. LOWS TONIGHT UNDER CLEAR SKIES
IN THE LOWER TO MID 70S.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 320 AM SATURDAY...
SUNDAY AND SUNDAY NIGHT:
A STRONG UPPER TROUGH OVER THE UPPER MS VALLEY SUNDAY MORNING WILL
TRACK SOUTHEASTWARD INTO THE OH VALLEY SUNDAY/SUNDAY NIGHT.
ACCOMPANYING SURFACE FRONT WILL APPROACH THE SOUTHERN APPALACHIANS
LATE SUNDAY NIGHT/MONDAY MORNING. IN THE MEAN TIME...PIEDMONT TROUGH
BISECTING THE AREA WILL BEGIN TO SHARPEN UP.
IN ADVANCE OF THE MAIN SHORTWAVE...CONVECTION...POSSIBLY A MCS IS
EXPECTED TO BE ONGOING OVER THE CENTRAL AND POSSIBLY SOUTHERN
APPALACHIANS EARLY SUNDAY. SOME STORMS COULD PERSIST INTO THE
AFTERNOON AS THEY MOVE EASTWARD INTO THE VIRGINIA PIEDMONT AND
COASTAL PLAIN. IF THIS CONVECTIN DOES INDEED HOLD TOGETHER...OUTFLOW
FROM THESE STORMS COULD SUPPORT A SLIGHT TO SMALL CHANCE OF STORMS
MAINLY ACROSS THE NORTH/NORTHEAST SUNDAY AFTERNOON AS HINTED BY THE
LATEST EC AND SOME OF THE CONVECTION ALLOWING MODELS. IF STORMS
DO DEVELOP...A MODIFIED EML LAYER CHARACTERIZED BY LAPSE RATES OF
7.25-7.50 COULD SUPPORT ISOLATED SEVERE STORM THAT COULD
LARGE HAIL. WILL RETAIN SLIGHT TO SMALL CHANCE POPS SUNDAY NIGHT
WITH BEST CHANCE IN PROXIMITY TO SURFACE FRONT TO OUR NW.
DEEP MIXING AND 850MB TEMPS IN EXCESS OF 21C WILL LEAD TO HIGHS IN
THE MID AND UPPER 90S. MIXING WILL DROP DEWPOINTS A
BIT...ESPECIALLY WEST OF THE PIEDMONT TROUGH...BUT TO THE EAST
DEWPOINTS ARE FORECAST TO REMAIN IN THE UPPER 60S TO AROUND 70. THE
RESULTING HEAT INDEX VALUES ARE IN THE 100-103. LOWS SUNDAY NIGHT
IN THE LOWER TO MID 70S.
MON/MON NIGHT: FOCUS ON MONDAY WILL BE THE LIKELIHOOD FOR SEVERE WEATHER AS A
STRONG COLD FRONT APPROACHES AND MOVES THROUGH THE AREA. THIS FRONT
WILL BE PROPELLED TOWARDS THE REGION AS A UNSEASONABLE STRONG UPPER
LEVEL TROUGH PUSHES EAST...WITH STRONG 40-60M HEIGHT FALLS EXPECTED
TO OVERSPREAD CENTRAL NC. THIS WILL COMBINE WITH THE EXPECTED STRONG
INSTABILITY (~1500-2000 J/KG MLCAPE) AND 40-50 KNOTS OF BULK SHEAR
TO PRODUCE SCATTERED SEVERE STORMS...WITH SUPERCELLS PROBABLE
CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING WINDS. ALTHOUGH
CONFIDENCE IS HIGH THAT THERE WILL BE SEVERE WEATHER ON MONDAY...
THERE ARE STILL SOME UNCERTAINTIES. DEEP WESTERLY FLOW MAY LIMIT
MOISTURE AND ULTIMATE COVERAGE...HOWEVER ANY STORM THAT DOES FORM
WILL LIKELY BE INTENSE. IN ADDITION...OUTFLOW BOUNDARIES AND DEBRIS
CLOUDINESS FROM CONVECTION SUNDAY NIGHT WILL HAVE AN IMPACT ON
CONVECTIVE DEVELOPMENT/LOCATION. REGARDLESS...AT THIS TIME...THE
BEST CHANCE FOR FOR PRECIP AND ULTIMATE SEVERE STORMS LOOKS TO BE
ACROSS THE EASTERN HALF OF THE FORECAST AREA (ALONG AND EAST OF THE
EXPECTED LOCATION OF THE LEE/PREFRONTAL TROUGH) AND POSSIBLY MORESO
ALONG AND EAST OF THE I-95 CORRIDOR WHERE ALL THE PARAMETERS WILL
LINE UP THE BEST. HIGH TEMPS ARE EXPECTED TO CLIMB INTO THE LOW TO
MID 90S AHEAD OF THE FRONT...WITH OVERNIGHT LOWS GENERALLY IN THE
MID TO UPPER 60S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...
UPPER LEVEL TROUGHING WILL STAY IN PLACE OVER THE EAST COAST
THROUGHOUT THE ENTIRE LONG TERM PERIOD PERIOD...WHILE AT THE SURFACE
COOL...CANADIAN HIGH PRESSURE WILL SETTLE OVER THE AREA. ALL OF THIS
WILL LEAD TO BELOW NORMAL TEMPS...WITH HIGHS GENERALLY IN THE
LOW/MID 80S AND OVERNIGHT LOWS IN THE LOW/MID 60S...POSSIBLY EVEN
SOME UPPER 50S IN THE NORMAL COOLER SPOTS. IN ADDITION... MOSTLY DRY
CONDITIONS ARE EXPECTED THROUGH THE END OF THE WEEK...ALTHOUGH WILL
SHOW A SLIGHT INCREASE IN PRECIP CHANCES BY FRIDAY AS MOISTURE
SLOWLY RETURNS.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 730 AM SATURDAY...
24-HR TAF PERIOD: RAP SOUNDINGS SUGGEST LIFR MORNING FOG/STRATUS
WILL LIFT AND DISPERSE TO MVFR AOA 14Z WITH VFR CONDITIONS RETURNING
BY 16Z. EXPECT MOSTLY DRY CONDITIONS TODAY WITH WINDS PREDOMINATELY
FROM THE SOUTHWEST AND LIGHT. THE PROBABILITY FOR FOG TONIGHT IS
LOW...LIKELY LIMITED FOG PRONE LOCATIONS SUCH AS KRWI.
LOOKING AHEAD: A COLD FRONT WILL APPROACH FROM THE NW SUNDAY/EARLY
NEXT WORK WEEK... BRINGING THE POTENTIAL FOR SHOWERS/STORMS AND SUB-
VFR CONDITIONS LATE SUNDAY (IN THE NORTHWEST) INTO MONDAY...
PARTICULARLY MONDAY (ESPECIALLY EAST). VFR CONDITIONS ARE EXPECTED
TO RETURN BEHIND THE FRONT ON TUESDAY AND CONTINUE THROUGH AT LEAST
MID WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...CBL
SHORT TERM...CBL/KRD
LONG TERM...KRD
AVIATION...CBL
AREA FORECAST DISCUSSION
NWS BISMARCK ND
933 AM CDT SAT JUL 26 2014
.UPDATE...
ISSUED AT 923 AM CDT SAT JUL 26 2014
GOING FORECAST IN PRETTY GOOD SHAPE WITH LOW PASSING TO THE NORTH
OF THE AREA WITH WINDS CONTINUING TO INCREASE. ONLY CHANGE WAS TO
ADJUST CLOUD COVER UP A BIT OVER NORTHERN ZONES AS IT WORKS IN
BEHIND AFOREMENTIONED LOW. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 633 AM CDT SAT JUL 26 2014
HRRR MODEL SO FAR CORRECTLY FORECAST SURFACE TROUGH PASSAGE AND
BAND OF CLOUDS ACROSS THE SOUTH CENTRAL. BELIEVE THIS FEATURE
WILL REMAIN DRY WITH SCATTERED SHOWERS SOUTH IN SOUTH DAKOTA. TO
THE NORTH...UPPER LEVEL LOW WILL BRING INCREASING NORTHWEST WINDS
AND SCATTERED SHOWERS TO THE NORTH TODAY. CURRENT FORECAST LOOKS
GOOD.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 322 AM CDT SAT JUL 26 2014
THE LATEST SATELLITE IMAGERY SHOWS A COMPACT CLOSED UPPER LOW
CIRCULATING OVER SOUTHEAST SASKATCHEWAN. A 1003MB SURFACE LOW WAS
LOCATED OVER WYNYARD SASKATCHEWAN...DIRECTLY BENEATH THE UPPER LOW.
AS A RESULT...THE LOW CONTINUES TO FILL/WEAKEN WITH TIME. ATTACHED
TO THE LOW IS A COLD FRONTAL BOUNDARY EXTENDING FROM SOUTHEAST
SASKATCHEWAN INTO MINOT AND GARRISON...AND CONTINUING SOUTH TO
GLEN ULLIN AND HETTINGER. COLD AIR ADVECTION TODAY COMBINED WITH A
DECENT PRESSURE GRADIENT SETTING UP FROM EASTERN MONTANA TO
NORTHWEST MINNESOTA WILL RESULT IN WINDY CONDITIONS. AS IS USUALLY
THE CASE...INCLUDING TODAYS DATA...THE MET/NAM WIND GUIDANCE IS
WEAKER THAN THE MAV/GFS. THE LATEST RAP13 AND ECMWF FAVORS THE
LOWER END OF STRONGEST WINDS. THIS ULTIMATELY SUGGESTS A WEAK
CONFIDENCE LEVEL FOR A WIND ADVISORY. WOULD LIKE TO MORE AGREEMENT
AMONGST THE FORECAST DATA WITH HIGHER SUSTAINED WINDS. THUS HAVE
DECIDED TO HOLD OFF ON ISSUING A WIND ADVISORY AS IT REMAINS
MARGINAL AT THIS TIME. THE DAY SHIFT CAN HAVE ANOTHER LOOK AS WINDS
INCREASE BY MID/LATE MORNING TO COMPARE ACTUAL VERSUS FORECAST.
OTHERWISE THE LATEST FOG/STRATUS LOOP SHOWS A LARGE SWATH OF
LOW/MID LEVEL BKN/OVC CLOUDS ASSOCIATED WITH THE SURFACE/UPPER LOW
CIRCULATION OVER SOUTHERN SASKATCHEWAN. THESE ARE NOW BEGINNING TO
CROSS THE NORTHWEST CORNER OF THE STATE. THE HRRR SHOWS THIS BAND
OF CLOUDS ARCING INTO WILLISTON AND MINOT BETWEEN 16Z-17Z. THERE
WILL BE AN AREA OF ISOLATED TO SCATTERED RAINSHOWERS AND ISOLATED
THUNDERSTORMS OVER THE NORTH CENTRAL TODAY. THE NAM WAS MOST
AGGRESSIVE IN GENERATING PRECIPITATION INTO SOUTH CENTRAL NORTH
DAKOTA THIS AFTERNOON. BUT WITH ALL OTHER MODELS MAINTAINING THE
THREAT OVER THE NORTH...HAVE DISCOUNTED THE NAM AND CONTINUED/REFINED
WITH WHAT THE PREVIOUS FORECAST HAD. HIGHS TODAY IN THE NORTH WITH
MOSTLY CLOUDY/WINDY/WET CONDITIONS WILL REACH THE UPPER 60S.
IN THE CENTRAL AND SOUTH...EXPECT MOSTLY SUNNY AND WINDY WEATHER
WITH HIGHS AROUND 80.
ALSO...SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER CENTRAL AND
NORTHERN SOUTH DAKOTA ALONG AND NORTH OF A LOW LEVEL CONVERGENCE
FIELD/FRONTAL BOUNDARY. THERE IS SOME HINT PER RAP13 THAT SHOWERS
WILL ENTER FAR SOUTHERN NORTH DAKOTA THROUGH 15Z SATURDAY. WILL
CONTINUE TO MONITOR THIS AND ADJUST AT THE LAST MINUTE IF TRENDS
CONTINUE TO SHOW DEVELOPMENT FARTHER NORTH.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 322 AM CDT SAT JUL 26 2014
THE EXTENDED PERIOD BEGINS THE AN UPPER LOW OVER SOUTH CENTRAL
CANADA THAT WILL MOVE SOUTHEAST AND MERGE INTO A LARGE HUDSON BAY
TROUGH SETTING UP A BLOCKING PATTERN ACROSS EASTERN NORTH AMERICA
WHICH WILL MAINTAIN A RIDGE OVER THE WESTERN US AND A TROUGH OVER
THE EAST. THE NORTHERN PLAINS WILL BE IN FOR A PERIOD OF QUIET
WEATHER FOR THIS EXTENDED PERIOD. FOR THE FIRST PORTION OF THE
FORECAST...SUNDAY THROUGH WEDNESDAY...EXPECT MAINLY DRY WEATHER
WITH A SLOW WARMING TREND. HIGHS IN THE UPPER 60S TO MID 70S ON
SUNDAY WILL MODERATE TO THE LOWER TO MIDDLE 80S BY WEDNESDAY
THROUGH FRIDAY. WITH THE H500 RIDGE FIRMLY IN PLACE OVER THE
WESTERN US ONLY A FEW WEAK IMPULSES MAY BE ABLE TO DRIFT ACROSS
THE NORTHERN PLAINS. FOR THIS POSSIBILITY LEFT WIDELY SCATTERED
CHANCES FOR THUNDERSTORMS WEDNESDAY WITH THURSDAY AND FRIDAY
BASICALLY DRY AND WARM.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 633 AM CDT SAT JUL 26 2014
GUSTY WEST TO NORTHWESTERLY WINDS BETWEEN 25KT AND 35KT WILL OCCUR
ACROSS THE TERMINALS BEGINNING AROUND 15Z AND CONTINUING THROUGH 02Z
SUNDAY. SATELLITE IMAGERY SHOWS LOW VFR/MVFR CIGS OVER SOUTHERN
SASKATCHEWAN. THIS WILL IMPACT KISN/KMOT FROM 16Z SATURDAY THROUGH
02Z SUNDAY. KMOT WILL HAVE THE HIGHEST PROBABILITY OF -SHRA AND
BRIEF PERIODS OF MVFR CIGS WHICH WILL BE COVERED IN A TEMPO GROUP
BETWEEN 18Z AND 22Z SATURDAY. THE REST OF THE TERMINALS WILL REMAIN
VFR.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...KS
LONG TERM...WAA
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
637 AM CDT SAT JUL 26 2014
.UPDATE...
ISSUED AT 633 AM CDT SAT JUL 26 2014
HRRR MODEL SO FAR CORRECTLY FORECAST SURFACE TROUGH PASSAGE AND
BAND OF CLOUDS ACROSS THE SOUTH CENTRAL. BELIEVE THIS FEATURE
WILL REMAIN DRY WITH SCATTERED SHOWERS SOUTH IN SOUTH DAKOTA. TO
THE NORTH...UPPER LEVEL LOW WILL BRING INCREASING NORTHWEST WINDS
AND SCATTERED SHOWERS TO THE NORTH TODAY. CURRENT FORECAST LOOKS
GOOD.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 322 AM CDT SAT JUL 26 2014
THE LATEST SATELLITE IMAGERY SHOWS A COMPACT CLOSED UPPER LOW
CIRCULATING OVER SOUTHEAST SASKATCHEWAN. A 1003MB SURFACE LOW WAS
LOCATED OVER WYNYARD SASKATCHEWAN...DIRECTLY BENEATH THE UPPER LOW.
AS A RESULT...THE LOW CONTINUES TO FILL/WEAKEN WITH TIME. ATTACHED
TO THE LOW IS A COLD FRONTAL BOUNDARY EXTENDING FROM SOUTHEAST
SASKATCHEWAN INTO MINOT AND GARRISON...AND CONTINUING SOUTH TO
GLEN ULLIN AND HETTINGER. COLD AIR ADVECTION TODAY COMBINED WITH A
DECENT PRESSURE GRADIENT SETTING UP FROM EASTERN MONTANA TO
NORTHWEST MINNESOTA WILL RESULT IN WINDY CONDITIONS. AS IS USUALLY
THE CASE...INCLUDING TODAYS DATA...THE MET/NAM WIND GUIDANCE IS
WEAKER THAN THE MAV/GFS. THE LATEST RAP13 AND ECMWF FAVORS THE
LOWER END OF STRONGEST WINDS. THIS ULTIMATELY SUGGESTS A WEAK
CONFIDENCE LEVEL FOR A WIND ADVISORY. WOULD LIKE TO MORE AGREEMENT
AMONGST THE FORECAST DATA WITH HIGHER SUSTAINED WINDS. THUS HAVE
DECIDED TO HOLD OFF ON ISSUING A WIND ADVISORY AS IT REMAINS
MARGINAL AT THIS TIME. THE DAY SHIFT CAN HAVE ANOTHER LOOK AS WINDS
INCREASE BY MID/LATE MORNING TO COMPARE ACTUAL VERSUS FORECAST.
OTHERWISE THE LATEST FOG/STRATUS LOOP SHOWS A LARGE SWATH OF
LOW/MID LEVEL BKN/OVC CLOUDS ASSOCIATED WITH THE SURFACE/UPPER LOW
CIRCULATION OVER SOUTHERN SASKATCHEWAN. THESE ARE NOW BEGINNING TO
CROSS THE NORTHWEST CORNER OF THE STATE. THE HRRR SHOWS THIS BAND
OF CLOUDS ARCING INTO WILLISTON AND MINOT BETWEEN 16Z-17Z. THERE
WILL BE AN AREA OF ISOLATED TO SCATTERED RAINSHOWERS AND ISOLATED
THUNDERSTORMS OVER THE NORTH CENTRAL TODAY. THE NAM WAS MOST
AGGRESSIVE IN GENERATING PRECIPITATION INTO SOUTH CENTRAL NORTH
DAKOTA THIS AFTERNOON. BUT WITH ALL OTHER MODELS MAINTAINING THE
THREAT OVER THE NORTH...HAVE DISCOUNTED THE NAM AND CONTINUED/REFINED
WITH WHAT THE PREVIOUS FORECAST HAD. HIGHS TODAY IN THE NORTH WITH
MOSTLY CLOUDY/WINDY/WET CONDITIONS WILL REACH THE UPPER 60S.
IN THE CENTRAL AND SOUTH...EXPECT MOSTLY SUNNY AND WINDY WEATHER
WITH HIGHS AROUND 80.
ALSO...SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER CENTRAL AND
NORTHERN SOUTH DAKOTA ALONG AND NORTH OF A LOW LEVEL CONVERGENCE
FIELD/FRONTAL BOUNDARY. THERE IS SOME HINT PER RAP13 THAT SHOWERS
WILL ENTER FAR SOUTHERN NORTH DAKOTA THROUGH 15Z SATURDAY. WILL
CONTINUE TO MONITOR THIS AND ADJUST AT THE LAST MINUTE IF TRENDS
CONTINUE TO SHOW DEVELOPMENT FARTHER NORTH.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 322 AM CDT SAT JUL 26 2014
THE EXTENDED PERIOD BEGINS THE AN UPPER LOW OVER SOUTH CENTRAL
CANADA THAT WILL MOVE SOUTHEAST AND MERGE INTO A LARGE HUDSON BAY
TROUGH SETTING UP A BLOCKING PATTERN ACROSS EASTERN NORTH AMERICA
WHICH WILL MAINTAIN A RIDGE OVER THE WESTERN US AND A TROUGH OVER
THE EAST. THE NORTHERN PLAINS WILL BE IN FOR A PERIOD OF QUIET
WEATHER FOR THIS EXTENDED PERIOD. FOR THE FIRST PORTION OF THE
FORECAST...SUNDAY THROUGH WEDNESDAY...EXPECT MAINLY DRY WEATHER
WITH A SLOW WARMING TREND. HIGHS IN THE UPPER 60S TO MID 70S ON
SUNDAY WILL MODERATE TO THE LOWER TO MIDDLE 80S BY WEDNESDAY
THROUGH FRIDAY. WITH THE H500 RIDGE FIRMLY IN PLACE OVER THE
WESTERN US ONLY A FEW WEAK IMPULSES MAY BE ABLE TO DRIFT ACROSS
THE NORTHERN PLAINS. FOR THIS POSSIBILITY LEFT WIDELY SCATTERED
CHANCES FOR THUNDERSTORMS WEDNESDAY WITH THURSDAY AND FRIDAY
BASICALLY DRY AND WARM.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 633 AM CDT SAT JUL 26 2014
GUSTY WEST TO NORTHWESTERLY WINDS BETWEEN 25KT AND 35KT WILL OCCUR
ACROSS THE TERMINALS BEGINNING AROUND 15Z AND CONTINUING THROUGH 02Z
SUNDAY. SATELLITE IMAGERY SHOWS LOW VFR/MVFR CIGS OVER SOUTHERN
SASKATCHEWAN. THIS WILL IMPACT KISN/KMOT FROM 16Z SATURDAY THROUGH
02Z SUNDAY. KMOT WILL HAVE THE HIGHEST PROBABILITY OF -SHRA AND
BRIEF PERIODS OF MVFR CIGS WHICH WILL BE COVERED IN A TEMPO GROUP
BETWEEN 18Z AND 22Z SATURDAY. THE REST OF THE TERMINALS WILL REMAIN
VFR.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...KS
LONG TERM...WAA
AVIATION...WAA
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1013 AM CDT SAT JUL 26 2014
.UPDATE...
WATCHING AREA OF SHOWERS AND STORMS UPSTREAM AS A WEAK SHORTWAVE
AND VORT MAX APPROACH. LATEST RAP AND HRRR SUGGEST POPS MAY NEED
TO BE BUMPED UP A BIT ACROSS THE SOUTHERN HALF OF THE FORECAST
AREA THIS AFTERNOON. IT DOES NOT LOOK LIKE A TON OF RAIN...BUT
SOME LOCATIONS MAY SEE AT LEAST ENOUGH TO WET THE GROUND.
THERE IS A NICE POCKET OF CLEARING ACROSS THE SOUTHEAST FORECAST
AREA RIGHT NOW. THERE ARE ALSO A LOT OF CLOUDS UP STREAM...SO
LOOKS LIKE SUN MAY BE LIMITED IN THE AFTERNOON. IF THIS PANS
OUT...HIGH TEMPS WILL PROBABLY NEED TO BE LOWERED A BIT.
&&
.AVIATION/18Z TAFS/...
WATCHING AREA OF SHOWERS AND STORMS UPSTREAM AS A WEAK
SHORTWAVE AND VORT MAX APPROACH. IT DOES NOT LOOK LIKE A TON OF
RAIN...BUT SOME LOCATIONS MAY SEE AT LEAST ENOUGH TO WET THE
GROUND THIS AFTERNOON. WILL WATCH UPSTREAM CONDITIONS AND UPDATE
TAFS AS CONFIDENCE INCREASES.
LATEST RAP AND NAM SOUNDINGS SUGGEST ENOUGH MIXING TODAY FOR VFR
CONDITIONS TO RETURN MOST PLACES BY AFTERNOON. SHOULD SEE MAINLY
VFR CONDITIONS THEN THROUGH SUNDAY. LOOKS LIKE A DECENT CHANCE FOR
SHOWERS AND STORMS SUNDAY AS AN UPPER LEVEL TROUGH AND SURFACE
FRONT MOVE THROUGH.
&&
.PREV DISCUSSION... /ISSUED 322 AM CDT SAT JUL 26 2014/
TODAY AND TONIGHT...FORECAST CONFIDENCE IS HIGH.
EXPECTING A QUIET...WARM AND HUMID DAY TODAY. WARM ADVECTION WITH
A DEPARTING SHORTWAVE IS BRINGING SOME SHOWERS TO NORTHERN IL
EARLY THIS MORNING AND SOME SPRINKLES ACROSS PARTS OF SOUTHERN WI.
THIS SHOULD MOSTLY BE OUT OF THE AREA BY OR SHORTLY AFTER SUNRISE.
MODELS THEN SHOW A WEAK MID LEVEL RIPPLE COMING ACROSS THE AREA
THIS AFTERNOON...ON THE SOUTHERN PERIPHERY OF THE IMPRESSIVE
CLOSED SYSTEM DROPPING SOUTH OUT OF SCNTRL CANADA. HOWEVER...THERE
IS A FORMIDABLE DRY LAYER FROM BELOW 850MB THROUGH ABOUT 650MB
THAT WILL MAKE IT HARD TO PRECIPITATE THROUGH.
ADDITIONALLY...THERE IS A RATHER STRONG LOW LEVEL CAP THAT WILL
WORK TO PREVENT ANY DEVELOPMENT. THEREFORE...WILL KEEP IT DRY
TODAY. THEREFORE...WILL KEEP IT DRY TODAY. LOWER CLOUDS AROUND
THIS MORNING...ASSOCIATED WITH THE EXITING SHORT WAVE...SHOULD
GRADUALLY CLEAR OUT WITH SUNSHINE EXPECTED. HIGHS SHOULD EASILY
HIT THE LOWER TO MID 80S.
THE LARGE CANADIAN SYSTEM WILL PUSH INTO NORTHWEST WI BY 12Z SUN
WITH SURFACE TROFING PUSHING THROUGH THE AREA AS WELL. THE COLUMN
STILL LOOKS QUITE DRY OUT AHEAD OF THE UPPER SYSTEM AND WE/LL
PROBABLY HAVE TO WAIT UNTIL SUNDAY FOR BETTER SATURATION AND
INSTABILITY TO BRING PRECIP WITH THE COOLING TEMPS ALOFT. WILL
INTRO A SMALL POP ACROSS THE NORTH AFTER MIDNIGHT TONIGHT FOR THE
SMALL THREAT THERE.
SHORT TERM...SUNDAY THROUGH MONDAY NIGHT...FORECAST CONFIDENCE IS
MEDIUM.
MODELS PUSH SURFACE TROUGH/COLD FRONT SOUTHEAST THROUGH THE REST
OF THE AREA DURING THE MORNING HOURS...WITH A SECONDARY TROUGH
MOVING SOUTH INTO THE AREA BY 00Z MONDAY. STRONG 500 MB SHORTWAVE
TROUGH ALSO SLIDES SOUTHEAST THROUGH THE AREA ON SUNDAY.
AREA FORECAST SOUNDINGS FROM THE NAM SHOWING A GOOD AMOUNT OF
MEAN LAYER CAPE AND DEEP LAYER SHEAR UNTIL AROUND 15Z SUNDAY IN
THE SOUTHEAST PORTIONS OF THE AREA...WHICH WOULD BRING A HAIL/WIND
RISK. GFS SOUNDINGS SHOW MUCH LESS INSTABILITY IN THE MORNING IN
THIS AREA...SO THINK NAM IS LIKELY OVERDONE WITH THE INSTABILITY.
BOTH MODELS DO BRING SOME RATHER WEAK TALL/SKINNY CAPE TO THE
AREA DURING THE AFTERNOON. KEPT LIKELY POPS IN THE AFTERNOON IN
MOST OF THE AREA...WITH RAIN SHOWERS LIKELY AND CHANCE OF THUNDER.
KEPT LOWER END POPS IN THE EVENING IN THE EAST...UNTIL COOLER AND
DRIER AIR MOVING INTO THE REGION ENDS THE PRECIPITATION. HIGHS
SUNDAY SHOULD REACH THE UPPER 70S TO LOWER 80S...THEN FALL INTO
THE EVENING WITH COLD AIR ADVECTION.
500 MB TROUGH REMAINS OVER SOUTHEAST CANADA AND INTO THE
NORTHEAST AND MID ATLANTIC REGION. THIS WILL KEEP 500 MB FLOW
NORTHWESTERLY OVER THE REGION...WITH WEAK VORTICITY MAXIMA MOVING
THROUGH AT TIMES. HIGH PRESSURE WILL BUILD INTO THE NORTHERN
PLAINS SUNDAY NIGHT INTO MONDAY NIGHT...WITH COLD AIR ADVECTION
BRINGING COOLER AND LESS HUMID AIR INTO THE AREA.
NAM ONLY MODEL SHOWING QPF MONDAY AFTERNOON/NIGHT WITH SHOWERS.
KEPT MONDAY DRY AS OTHER MODELS KEEP DRY CONDITIONS. TEMPERATURES
WILL REACH THE LOWER TO MID 70S MONDAY...WITH LOWS MAINLY IN THE
50S SUNDAY NIGHT AND MONDAY NIGHT.
LONG TERM...TUESDAY THROUGH FRIDAY...FORECAST CONFIDENCE IS
MEDIUM.
ECMWF/GFS GENERALLY SHOW NORTHWEST FLOW AT 500 MB REMAINING OVER
THE REGION FOR THIS PERIOD...WITH WEAK VORTICITY MAXIMA MOVING
THROUGH THE AREA AT TIMES. SURFACE HIGH PRESSURE SLIDES SLOWLY
SOUTHEAST THROUGH THE CENTRAL PLAINS INTO THE MIDDLE MISSISSIPPI
RIVER VALLEY AREA. THE MODELS GENERATE QPF DURING EACH AFTERNOON
INTO THE EARLY EVENING HOURS.
GFS FORECAST SOUNDINGS SHOW WEAK INSTABILITY TUESDAY
AFTERNOON...WITH BETTER MEAN LAYER CAPES IN THE AFTERNOON HOURS
FOR LATER IN THE WEEK. FOR NOW...CONTINUED TO HAVE LOWER END POPS
EACH DAY AND NIGHT FOR MOST OF THIS PERIOD. TEMPERATURES LOOK TO
BE SLIGHTLY BELOW SEASONAL NORMALS EACH DAY.
AVIATION/12Z TAFS/...
LOOK FOR AN AREA OF MVFR CLOUDS THIS MORNING...ESPECIALLY FROM
KMSN ON WEST. THESE CLOUDS ARE ASSOCIATED WITH A WEAK TROF AND
WARM ADVECTION MOVING THROUGH AND SHOULD BEGIN TO IMPROVE FROM
WEST TO EAST SHORTLY AFTER 12Z THIS MORNING. THEN LOOK FOR VFR
CONDITIONS THROUGH THE REMAINDER OF THE TAF PERIOD.
THE CHANCES OF SHOWER OR STORMS LOOK VERY SMALL UNTIL WE GET
CLOSER TO THE INFLUENCE OF A LARGE UPPER LEVEL CLOSED LOW DROPPING
IN AROUND 12Z SUNDAY MORNING. SO...GENERALLY A VERY QUIET TAF
PERIOD WITH LIGHT WINDS LESS THAN 10 KNOTS.
MARINE...
COULD SEE SMALL CRAFT ADVISORY CONDITIONS DEVELOP LATER SUNDAY
INTO MONDAY...AS NORTHWEST WINDS INCREASE IN THE WAKE OF PASSING
LOW PRESSURE.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...DDV
TODAY/TONIGHT AND AVIATION/MARINE...DAVIS
SUNDAY THROUGH FRIDAY...WOOD
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
749 AM CDT SAT JUL 26 2014
.UPDATE...
ISSUED AT 748 AM CDT SAT JUL 26 2014
THE 26.06Z DETERMINISTIC AND MESO MODELS CONTINUE TO SUGGEST THAT
THERE WILL BE STRONG 900 TO 500 MB FRONTOGENETIC FORCING MAINLY
SOUTH OF INTERSTATE 90 TODAY. VAD WIND PROFILERS SHOW A 30 TO 45
KNOT CONVERGENCE INTO THE 700 MB FRONT ACROSS SOUTHWEST MINNESOTA.
OVERALL THE HRRR AND A COUPLE /MEMBERS 2 AND 3/ OF THE 26.06Z HOP
WRF SHOW THAT THE PRECIPITATION CURRENTLY OVER EASTERN SOUTH
DAKOTA AND SOUTHWEST MINNESOTA WILL CONTINUE TO SPREAD EAST INTO
THE AREAS MAINLY SOUTH OF INTERSTATE 90. DUE TO THIS...RAISED THE
CHANCES OF SHOWERS UP SIGNIFICANTLY. THERE WILL BE EVEN ENOUGH
INSTABILITY ALOFT FOR ISOLATED THUNDERSTORMS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CDT SAT JUL 26 2014
LATEST WATER VAPOR SATELLITE IMAGERY INDICATING UPPER LEVEL CLOSED
LOW OVER SOUTHERN SASKATCHEWAN AND WEST TO EAST ZONAL FLOW OVER
THE NORTHERN PLAINS. WEAK SHORTWAVE TROUGH OVER CENTRAL AND
EASTERN SOUTH DAKOTA EMBEDDED IN WEST TO EAST ZONAL FLOW IS
PRODUCING SHOWERS AND ISOLATED THUNDERSTORMS OVER CENTRAL SOUTH
DAKOTA PER MOSAIC RADAR.
MAIN FORECAST CONCERNS ARE PRECIPITATION CHANCES TODAY INTO TONIGHT.
THE 26.00Z GFS/NAM ARE IN GOOD AGREEMENT IN MOVING WEAK IMPULSE OVER
CENTRAL SOUTH DAKOTA INTO THE SOUTHERN PART OF THE FORECAST AREA.
THE 26.00Z GFS/NAM ARE INDICATING ISENTROPIC LIFT AT 315K SURFACE
AND PRODUCE LIGHT QPF ACROSS PARTS OF NORTHEAST IOWA AND SOUTHWEST
WISCONSIN. THE LATEST 26.05Z HRRR IS INDICATING THE SHRA/TSRA OVER
CENTRAL SOUTH DAKOTA TO WEAKEN AND POSSIBLY PRODUCE LIGHT SHOWERS OR
SPRINKLES OVER THE SOUTHERN PART OF THE FORECAST AREA. BUFKIT
SOUNDINGS SHOW QUITE A BIT OF DRY AIRMASS BELOW 700MB OVER THE
SOUTHERN FORECAST AREA. HOWEVER...WITH THE LIFT ASSOCIATED WITH THE
WEAK IMPULSE...THIS MAY PRODUCE AN ISOLATE SHRA/TSRA ACROSS SOUTHERN
FORECAST AREA THIS MORNING INTO THE EARLY AFTERNOON HOURS. HAVE
INTRODUCE A SMALL CHANCE OF PRECIPITATION OVER NORTHEAST IOWA AND
PARTS OF SOUTHWEST WISCONSIN.
UPPER LEVEL CLOSED LOW OVER SOUTHERN SASKATCHEWAN MOVES SOUTH
INTO THE GREAT LAKES REGION TONIGHT. THE 26.00Z GFS/NAM SUGGEST
INCREASING FORCING/LIFT AFTER 06Z OVER NORTHERN PARTS OF THE
FORECAST AREA AND INDICATE ELEVATED CAPE ASSOCIATED WITH UPPER
LEVEL CLOSED LOW. WILL CONTINUE TREND OF PRECIPITATION CHANCES
ACROSS THE NORTHERN PARTS OF THE FORECAST AREA.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 320 AM CDT SAT JUL 26 2014
SUNDAY...THE 26.00Z GFS/NAM CONTINUE TO SHOW DECENT 500-300MB PV
ADVECTION AND DEEP QG FORCING ASSOCIATED WITH THE CLOSED UPPER LEVEL
LOW OVER MUCH OF THE NORTHERN AND EASTERN PART OF THE FORECAST
AREA. CONFIDENCE IS INCREASING THIS AREA WILL SEE SHOWERS AND
POSSIBLY AN ISOLATED THUNDERSTORM.
THE 26.00Z GFS/GEM/ECMWF ARE IN GOOD AGREEMENT DIGGING UPPER LEVEL
TROUGH OVER THE EASTERN UNITED STATES SUNDAY NIGHT INTO FRIDAY. THE
MAIN DIFFERENCE BETWEEN THE MODELS IS TIMING THE VERY WEAK IMPULSES
EMBEDDED IN THE NORTHERLY FLOW ALOFT INTO THE GREAT LAKES REGION.
THE MODELS CONTINUE TO PRODUCE LIGHT QPF OVER PARTS OF THE
FORECAST AREA MAINLY FROM WEDNESDAY INTO FRIDAY. HOWEVER...WITH
VERY WEAK MOISTURE CONVERGENCE AND VERY WEAK IMPULSES EMBEDDED IN
NORTHERLY FLOW. CONFIDENCE IN PRECIPITATION CHANCES IS LOW THROUGH
THIS PERIOD.
TEMPERATURES SUNDAY NIGHT INTO FRIDAY WILL BE UNSEASONABLY COOL
THROUGH MIDDLE OF THE WEEK AND MODERATE TO NEAR NORMAL BY END OF THE
WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 655 AM CDT SAT JUL 26 2014
AREAS OF DENSE FOG AT KRST WILL BECOME MVFR BY 26.1330Z...AND VFR
BY 26.17Z. THE CEILINGS WILL LIKELY BE LIFR THROUGH
26.1330Z...THEN BECOME MVFR BY 26.15Z...AND THEN VFR. MEANWHILE
AT KLSE THE MVFR CEILING WILL BECOME VFR BY 26.16Z. ONE THING THAT
WILL HAVE TO BE WATCHED THIS MORNING IS THE SHOWERS AND SCATTERED
THUNDERSTORMS ACROSS SOUTHWEST MINNESOTA. WITH MOST OF THE MODELS
SHOWING STRONG 900 TO 500 MB FRONTOGENESIS...THERE IS THE
POTENTIAL THAT THIS PRECIPITATION COULD MOVE INTO KRST AFTER
26.15Z AND KLSE AFTER 26.16Z. THIS PRECIPITATION COULD THEN LINGER
THROUGH 26.22Z.
FOR THE REMAINDER OF THE PERIOD...VFR VISIBILITIES AND CEILINGS
ARE EXPECTED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...BOYNE
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
659 AM CDT SAT JUL 26 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CDT SAT JUL 26 2014
LATEST WATER VAPOR SATELLITE IMAGERY INDICATING UPPER LEVEL CLOSED
LOW OVER SOUTHERN SASKATCHEWAN AND WEST TO EAST ZONAL FLOW OVER
THE NORTHERN PLAINS. WEAK SHORTWAVE TROUGH OVER CENTRAL AND
EASTERN SOUTH DAKOTA EMBEDDED IN WEST TO EAST ZONAL FLOW IS
PRODUCING SHOWERS AND ISOLATED THUNDERSTORMS OVER CENTRAL SOUTH
DAKOTA PER MOSAIC RADAR.
MAIN FORECAST CONCERNS ARE PRECIPITATION CHANCES TODAY INTO TONIGHT.
THE 26.00Z GFS/NAM ARE IN GOOD AGREEMENT IN MOVING WEAK IMPULSE OVER
CENTRAL SOUTH DAKOTA INTO THE SOUTHERN PART OF THE FORECAST AREA.
THE 26.00Z GFS/NAM ARE INDICATING ISENTROPIC LIFT AT 315K SURFACE
AND PRODUCE LIGHT QPF ACROSS PARTS OF NORTHEAST IOWA AND SOUTHWEST
WISCONSIN. THE LATEST 26.05Z HRRR IS INDICATING THE SHRA/TSRA OVER
CENTRAL SOUTH DAKOTA TO WEAKEN AND POSSIBLY PRODUCE LIGHT SHOWERS OR
SPRINKLES OVER THE SOUTHERN PART OF THE FORECAST AREA. BUFKIT
SOUNDINGS SHOW QUITE A BIT OF DRY AIRMASS BELOW 700MB OVER THE
SOUTHERN FORECAST AREA. HOWEVER...WITH THE LIFT ASSOCIATED WITH THE
WEAK IMPULSE...THIS MAY PRODUCE AN ISOLATE SHRA/TSRA ACROSS SOUTHERN
FORECAST AREA THIS MORNING INTO THE EARLY AFTERNOON HOURS. HAVE
INTRODUCE A SMALL CHANCE OF PRECIPITATION OVER NORTHEAST IOWA AND
PARTS OF SOUTHWEST WISCONSIN.
UPPER LEVEL CLOSED LOW OVER SOUTHERN SASKATCHEWAN MOVES SOUTH
INTO THE GREAT LAKES REGION TONIGHT. THE 26.00Z GFS/NAM SUGGEST
INCREASING FORCING/LIFT AFTER 06Z OVER NORTHERN PARTS OF THE
FORECAST AREA AND INDICATE ELEVATED CAPE ASSOCIATED WITH UPPER
LEVEL CLOSED LOW. WILL CONTINUE TREND OF PRECIPITATION CHANCES
ACROSS THE NORTHERN PARTS OF THE FORECAST AREA.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 320 AM CDT SAT JUL 26 2014
SUNDAY...THE 26.00Z GFS/NAM CONTINUE TO SHOW DECENT 500-300MB PV
ADVECTION AND DEEP QG FORCING ASSOCIATED WITH THE CLOSED UPPER LEVEL
LOW OVER MUCH OF THE NORTHERN AND EASTERN PART OF THE FORECAST
AREA. CONFIDENCE IS INCREASING THIS AREA WILL SEE SHOWERS AND
POSSIBLY AN ISOLATED THUNDERSTORM.
THE 26.00Z GFS/GEM/ECMWF ARE IN GOOD AGREEMENT DIGGING UPPER LEVEL
TROUGH OVER THE EASTERN UNITED STATES SUNDAY NIGHT INTO FRIDAY. THE
MAIN DIFFERENCE BETWEEN THE MODELS IS TIMING THE VERY WEAK IMPULSES
EMBEDDED IN THE NORTHERLY FLOW ALOFT INTO THE GREAT LAKES REGION.
THE MODELS CONTINUE TO PRODUCE LIGHT QPF OVER PARTS OF THE
FORECAST AREA MAINLY FROM WEDNESDAY INTO FRIDAY. HOWEVER...WITH
VERY WEAK MOISTURE CONVERGENCE AND VERY WEAK IMPULSES EMBEDDED IN
NORTHERLY FLOW. CONFIDENCE IN PRECIPITATION CHANCES IS LOW THROUGH
THIS PERIOD.
TEMPERATURES SUNDAY NIGHT INTO FRIDAY WILL BE UNSEASONABLY COOL
THROUGH MIDDLE OF THE WEEK AND MODERATE TO NEAR NORMAL BY END OF THE
WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 655 AM CDT SAT JUL 26 2014
AREAS OF DENSE FOG AT KRST WILL BECOME MVFR BY 26.1330Z...AND VFR
BY 26.17Z. THE CEILINGS WILL LIKELY BE LIFR THROUGH
26.1330Z...THEN BECOME MVFR BY 26.15Z...AND THEN VFR. MEANWHILE
AT KLSE THE MVFR CEILING WILL BECOME VFR BY 26.16Z. ONE THING THAT
WILL HAVE TO BE WATCHED THIS MORNING IS THE SHOWERS AND SCATTERED
THUNDERSTORMS ACROSS SOUTHWEST MINNESOTA. WITH MOST OF THE MODELS
SHOWING STRONG 900 TO 500 MB FRONTOGENESIS...THERE IS THE
POTENTIAL THAT THIS PRECIPITATION COULD MOVE INTO KRST AFTER
26.15Z AND KLSE AFTER 26.16Z. THIS PRECIPITATION COULD THEN LINGER
THROUGH 26.22Z.
FOR THE REMAINDER OF THE PERIOD...VFR VISIBILITIES AND CEILINGS
ARE EXPECTED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS TUCSON AZ
915 AM MST SAT JUL 26 2014
.SYNOPSIS...A CHANCE OF SHOWERS AND THUNDERSTORMS LATER TODAY AND
TONIGHT. WE WILL CONTINUE TO HAVE ENOUGH MOISTURE FOR SCATTERED
MAINLY AFTERNOON AND EVENING THUNDERSTORMS DURING THE UPCOMING WEEK.
SOME STORMS WILL GENERATE LOCALLY HEAVY RAIN AND STRONG GUSTY WINDS.
&&
.DISCUSSION...NOT A CLEAR CUT DAY. 12Z SOUNDING HAS DECENT MOISTURE
AT 1.37 INCHES. RIGHT AT THE MOMENT WE CONTINUE TO RELY ON CONTINUED
RECYCLE OF SURGE MOISTURE WITH MODEST LOW LEVEL REINFORCEMENT. MID
LEVELS HOWEVER SHOWING SOME DRYING TRENDS WITH PRECIPITABLE WATER
VALUES UNDER 1 INCH IMMEDIATELY UPSTREAM EAST AND SOUTHEAST AS PER
BLENDED TOTAL PRECIPITABLE WATER AND GOES WATER VAPOR TRENDS.
FAVORABLE TEMPERATURE PROFILE INCLUDING -7 AT H5 AND WITH THE
MORNING SOUNDING WE CAN STILL MANAGE DECENT CONVECTIVE POTENTIAL
THIS AFTERNOON...HOWEVER AN ANTICIPATED FLUCTUATION OF THE SOUTHWEST
QUADRANT OF THE HIGH STRENGTHENING OVER THE NEXT 12 HOURS MIGHT ADD
A DEGREE OR TWO OF WARMING IN MID LEVELS. OVERALL WE MIGHT BE
HEADING TOWARD A LESS BUSY DAY AND A QUICK LOOK AT EARLY SHORT RANGE
MODEL TRENDS INCLUDING 12Z U OF A WRF-NAM AND LATEST HRRR ALL
POINTING TOWARD LESS ACTIVITY THAN WE ARE CURRENTLY ADVERTISING. WE
ARE ADJUSTING THE FORECAST DOWN A BIT TODAY AND EARLY THIS EVENING
WITH AN EMPHASIS ON MOUNTAINS THIS AFTERNOON AND VALLEY AREAS EAST
AND SOUTH OF TUCSON INTO THIS EVENING. OUTFLOWS COULD PUSH ACTIVITY
FURTHER WEST BUT NOT AS ORGANIZED AS YESTERDAY.
THE TIMING ON THE EASTERLY IMPULSE PUSHING ACROSS NORTHERN CHIHUAHUA
AND NORTHERN SONORA/SOUTHEAST ARIZONA HAS SLOWED A BIT AND COULD NOW
BE MORE OF A FACTOR ENHANCING SUNDAY AFTERNOON STORMS.
&&
.AVIATION...VALID THRU 27/16Z.
DRY CONDITIONS WILL OCCUR THIS MORNING FOLLOWED BY SCATTERED -TSRA/
-SHRA THIS AFTERNOON THRU TONIGHT. EXPECT MVFR VISIBILITIES WITH
+TSRA AS WELL AS POTENTIAL WIND GUSTS TO NEAR 40-45 KTS.
OTHERWISE...MOSTLY CLEAR SKIES EAST OF KTUS WITH PARTLY CLOUDY SKIES
WEST OF TUCSON THIS MORNING FOLLOWED BY CLOUD DECKS GENERALLY AT
8-15K FT AGL THIS AFTERNOON THRU TONIGHT. AVIATION DISCUSSION NOT
UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...MOISTURE WILL BE SUFFICIENT TO PROVIDE SCATTERED
THUNDERSTORMS INTO AT LEAST THE MIDDLE OF THE UPCOMING WEEK. MUCH OF
THIS ACTIVITY WILL OCCUR DURING THE AFTERNOON AND EVENING HOURS.
EXPECT STRONG...GUSTY AND ERRATIC WINDS NEAR THE STRONGER STORMS.
OTHERWISE...NORMAL DIURNAL WIND TRENDS WILL OCCUR WITH OCCASIONAL
GUSTS DURING THE AFTERNOON HOURS DUE TO DAYTIME HEATING.
&&
.PREV DISCUSSION...THE BROAD SCALE PATTERN THRU AT LEAST THE MIDDLE
OF THE UPCOMING WEEK WILL BE CHARACTERIZED BY A HIGHLY AMPLIFIED
UPPER RIDGE OVER THE INTERMOUNTAIN WEST. NO APPRECIABLE CHANGE IN
AVAILABLE MOISTURE FOR CONVECTIVE ACTIVITY IS PROGGED TO OCCUR THIS
FORECAST PERIOD. OCCASIONAL DISTURBANCES EMBEDDED WITHIN THE
GENERALLY ELY FLOW REGIME WILL SERVE TO ENHANCE SHOWER/TSTM ACTIVITY.
SUN...
26/00Z GFS/ECMWF DEPICT A DISTURBANCE TO APPROACH SE AZ FROM THE
EAST SUN AFTERNOON. THIS SYSTEM MAY ENHANCE THE POTENTIAL FOR CELLS
TO FAVOR STRONG WIND GUSTS AND SMALL HAIL. HAVE DEPICTED SCATTERED
COVERAGE OF SHOWERS/TSTMS ACROSS MUCH OF THIS FORECAST AREA SUN
AFTERNOON/EVENING. THERE IS ENOUGH MOISTURE TO JUSTIFY A SLIGHT
CHANCE OF SHOWERS/TSTMS AREA-WIDE LATE SUN NIGHT.
MON-FRI...
EXPECT SCATTERED MAINLY AFTERNOON/EVENING SHOWERS/TSTMS TO PREVAIL...
WITH THE BULK OF THIS ACTIVITY TO GENERALLY BE EAST AND SOUTH OF
TUCSON.
HIGH TEMPS THRU NEXT FRI FROM TUCSON WWD WILL GENERALLY BE WITHIN A
DEGREE-OR-TWO OF SEASONAL NORMALS FOR LATE JULY. MEANWHILE...DAYTIME
TEMPS EAST OF TUCSON WILL GENERALLY AVERAGE ABOUT 2-5 DEGS F OR SO
ABOVE NORMAL.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
MEYER/BROST/FRANCIS
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
252 PM EDT SAT JUL 26 2014
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
18Z SURFACE ANALYSIS SHOWS A WEAK SURFACE TROUGH SITUATED ACROSS
SOUTH CENTRAL GA THIS AFTERNOON. WV/500MB ANALYSIS SHOWS A WEAK
SHEAR AXIS AND SHORTWAVE IN THE VICINITY OF THE OLD FRONT. A FEW
SHOWERS HAVE POPPED UP JUST OUTSIDE OF THE CWFA. THE LATEST RUNS OF
THE HRRR DO HAVE SOME CONVECTION DEVELOPING ACROSS THE SOUTHERN TIER
OF ZONES LATE THIS EVENING...SO WILL KEEP THE MENTION OF SLIGHT
CHANCE POPS IN THE FORECAST.
ANY CONVECTION ACROSS THE SOUTHERN ZONES LATE THIS AFTERNOON/EARLY
EVENING SHOULD DIMINISH QUICKLY WITH THE SETTING OF THE SUN. SKIES
ARE EXPECTED TO BE MOSTLY CLEAR WITH NEAR NORMAL LOW TEMPERATURES.
A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS IS ONCE AGAIN POSSIBLE
SUNDAY AFTERNOON ACROSS THE SOUTHERN ZONES. DEEPER MOISTURE WILL
CONTINUE ACROSS THAT REGION...ALONG WITH THE WEAK/STATIONARY SURFACE
TROUGH. IN ADDITION...A COLD FRONT WILL BEGIN DROP SOUTH ACROSS THE
TN VALLEY. MODELS ARE PROGGING AN MCS TO DEVELOP AND MOVE NORTH OF
THE CWFA...BUT THE TAIL END OF THE SYSTEM HAS THE POTENTIAL TO CLIP
THE NORTHERN ZONES. POPS SHOULD BEGIN TO INCREASE TO AROUND 30 TO 40
PERCENT OVERNIGHT.
MODELS CONTINUE TO PROG ANY MCS TO WEAKEN AS IT APPROACHES THE CWFA
EARLY MONDAY MORNING. HOWEVER...THERE WILL BE FAIRLY DECENT SURFACE
INSTABILITY AND STEEP MID LEVEL LAPSE RATES PRESENT. MOST OF THE MID
LEVEL FORCING WILL SKATE BY TO THE NORTH. EVEN SO...DO THINK
THUNDERSTORMS...A FEW STRONG...COULD APPROACH THE NORTHERN ZONES BY
SUNRISE MONDAY. LOCALLY HEAVY RAINFALL WILL ALSO BE POSSIBLE.
NLISTEMAA
.LONG TERM /MONDAY THROUGH SATURDAY/...
MAINLY ONLY TWEAKS TO THE LONG TERM BASED ON THE LATEST GUIDANCE.
WITH A MUCH COOLER AIRMASS BEHIND THE NEXT FRONT...SOME LOW
TEMPERATURE RECORDS WILL BE THREATENED WEDNESDAY AND THURSDAY
MORNINGS. LEANED HARD ON WPC MAX/MIN TEMPERATURES.
BDL
PREVIOUS DISCUSSION
FRONTAL SYSTEM PUSHES SOUTH OUT OF TN SUNDAY NIGHT AND INTO N GA
MONDAY MORNING. MOISTURE INCREASES ACROSS THE STATE SUNDAY AHEAD
OF THE APPROACHING FRONTAL SYSTEM. THIS FRONT IS EXPECTED TO MOVE
INTO NW GA BY 06Z-12Z MON AND PUSH SOUTH TO THE FL BORDER BY 12Z
TUE. AS THIS FRONT MOVES ACROSS GA INSTABILITIES INCREASE WITH
CAPES EXPECTED AROUND 1000 TO 3000 J/KG AND LIS RANGING FROM -3
TO -7. SHEAR VALUES DO NOT LOOK THAT IMPRESSIVE BUT THEY DO
INCREASE A BIT WITH THE FRONTAL PASSAGE. CURRENTLY SPC HAS THE DAY
2 SLIGHT RISK AREA COMING SOUTH OUT OF TN RIGHT TO OUR NORTHERN
BORDER BY 12Z MON. SPC AS GA ON DAY 3 IN JUST A SEE TEXT AREA.
WOULD NOT BE SURPRISED TO SEE THAT EXTENDED FURTHER SOUTH AS WE
GET CLOSER TO THE EVENT. ONCE THIS FRONT PASSES THROUGH...AN UPPER
LEVEL DEEP LONG WAVE TROUGH REMAINS POSITIONED OVER THE AREA
THROUGH MUCH OF NEXT WEEK...KEEPING LOWER DEW POINTS AND COOLER
TEMPERATURES IN PLACE AT LEAST THROUGH TUE/WED. MOISTURE BEGINS TO
INCREASE AGAIN BY THE END OF THE WORK WEEK ACROSS SOUTHERN PORTION
OF OUR CWA. WILL KEEP DIURNALLY DRIVEN SLIGHT TO LOW CHANCE POPS
IN ACROSS THE AREA DAYS 6 AND 7. BEGINNING TUESDAY...SHOULD SEE
BELOW AVERAGE TEMPERATURES WITH HIGHS IN THE UPPER 70S NORTH AND
LOW 80S ELSEWHERE...AND LOWS IN THE 60S.
01
&&
.CLIMATE...
RECORDS FOR 07-30
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 102 1999 69 1984 76 2010 60 1925
1915
KATL 98 1986 68 1984 78 1896 61 1936
1980
KCSG 102 2010 76 1984 79 2010 65 1957
1986
KMCN 103 1986 74 1984 76 2010 62 1920
2008
1958
RECORDS FOR 07-31
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 103 1999 71 1916 76 1931 59 1936
KATL 99 1999 62 1936 78 1915 59 1936
1986 1896
1980
KCSG 104 1986 74 1997 78 2011 66 1997
1981 2010
KMCN 105 1986 68 1936 77 1931 61 1936
&&
.AVIATION...
18Z UPDATE...
RELATIVELY QUIET TAF PERIOD ON TAP WITH VFR CONDITIONS AND NO PRECIP
EXPECTED AT ATL THROUGH THE PERIOD. WESTERLY WINDS WILL PREVAIL AND
DID INCLUDE SOME GUSTS DURING THE DAY THAT WILL RELAX DURING THE
OVERNIGHT HOURS. MUCH THE SAME AT OTHER TAF SITES...EXCEPT FOG WILL
CONTRIBUTE TO MVFR CONDITIONS AT AHN AND CSG OVERNIGHT.
//ATL CONFIDENCE...18Z UPDATE...
HIGH CONFIDENCE ALL ELEMENTS.
WILLIS/NLISTEMAA
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 74 95 76 91 / 5 10 20 20
ATLANTA 74 93 76 87 / 5 10 20 20
BLAIRSVILLE 67 88 68 80 / 0 20 40 20
CARTERSVILLE 71 93 74 87 / 5 10 30 20
COLUMBUS 76 95 76 92 / 10 10 10 50
GAINESVILLE 73 93 74 87 / 5 10 30 20
MACON 74 95 77 93 / 10 10 10 50
ROME 71 94 74 87 / 0 20 40 20
PEACHTREE CITY 72 93 75 89 / 5 10 20 30
VIDALIA 77 95 78 94 / 10 20 10 50
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...NLISTEMAA
LONG TERM....BDL
AVIATION...WILLIS/NLISTEMAA
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
227 PM CDT SAT JUL 26 2014
.DISCUSSION...
1150 AM...LATE MORNING UPDATE...TWO FEATURES OF NOTE LATE THIS
MORNING...A WEAK WAVE OVER SOUTHERN MN THAT WILL MOVE ACROSS THE
AREA THIS AFTERNOON AND WHAT IS EXPECTED TO BE THE MAIN WAVE
CURRENTLY OVER NORTHEAST KS MOVING INTO NORTHWEST MO. FORECAST
SOUNDINGS SHOW A FAIRLY STRONG CAP ACROSS MUCH OF THE AREA INTO
THIS AFTERNOON AND WHILE SHORT TERM/HI RES GUIDANCE DOES SUGGEST
SOME ISOLATED ACTIVITY IS POSSIBLE...APPEARS MUCH OF THE AREA WILL
REMAIN DRY INTO THIS AFTERNOON.
THUNDERSTORMS DEVELOPING OVER NORTHWEST MO WILL CONTINUE MOVING
EAST THIS AFTERNOON AND ACROSS A VERY UNSTABLE/MOIST ATMOSPHERE.
THIS ACTIVITY IS EXPECTED TO CONTINUE EAST AND ACROSS THE
SOUTHERN CWA LATE THIS AFTERNOON OR MORE LIKELY DURING THE EVENING
HOURS. NO CHANGES TO PREVIOUS THOUGHTS ON SEVERE POTENTIAL WITH A
LINE OF STORMS WITH THE POTENTIAL FOR WIDESPREAD DAMAGING WINDS
THE MOST LIKELY THREAT. HOW FAR NORTH THIS LINE EXTENDS IS STILL A
BIT UNCERTAIN AND WHILE IT WILL LIKELY REMAIN SOUTH OF I-80...
COULD BE EVEN FURTHER SOUTH...PERHAPS SOUTH OF THE KANKAKEE RIVER.
OTHERWISE...EXTENSIVE CLOUD COVER IS SLOWING THE WARMING TREND.
WITH VERY WARM LOW LEVELS...A FEW HOURS OF SUN...IF THAT WERE TO
OCCUR...COULD PUSH TEMPS TO CURRENT FORECAST HIGHS OF MID 80S...SO
NO LARGE CHANGES TO HIGHS BUT TEMP TRENDS WILL REQUIRE UPDATES.
CMS
//PREV DISCUSSION...
322 AM CDT
SYNOPSIS...UNSETTLED WEATHER IS EXPECTED TODAY WITH SEVERE STORMS
POSSIBLE ALONG AND SOUTH OF I-80. COOLER CONDITIONS MOVE IN
TOMORROW AND PERSIST THROUGH THE REST OF THE WEEK.
TODAY AND TONIGHT...
SHOWERS HAVE SPROUTED OVER NORTHWEST AND NORTH CENTRAL IL EARLY
THIS MORNING AT THE NOSE OF THE LOW LEVEL JET. EXPECTING SHOWERS
AND A FEW THUNDERSTORMS TO FESTER SOUTH OF I-88 BEFORE PUSHING
EAST OF THE WARNING AREA BY MID MORNING. NOT EXPECTING ANY SEVERE
WEATHER WITH THESE SHOWERS AND STORMS AS A SIGNIFICANT CAP IS IN
PLACE ALONG WITH LIMITED INSTABILITY.
UPPER LEVEL HIGH PRESSURE REMAINS OVER THE SOUTHERN U.S. AND IT IS
STILL EXPECTED TO RETROGRADE OVER THE SW U.S. BY MONDAY NIGHT. THE
UPPER LEVEL LOW OVER SOUTHERN SASKATCHEWAN WILL MOVE OVER WI SUNDAY
MORNING. AT THE SURFACE...THE LOW OVER THE PLAINS IS SLOWLY
TREKKING EAST AND WILL MOVE OVER CENTRAL IL TONIGHT. THE SECOND LOW
OVER SOUTHERN SASKATCHEWAN WILL SLIDE SOUTHEAST AND MOVE OVER LAKE
MI SUNDAY MORNING.
A WARM FRONT IS OVER CENTRAL MISSOURI AND IT WILL MOVE NORTH INTO
THE SOUTHERN FORECAST AREA THIS MORNING. DEW POINTS WILL RISE INTO
THE 70S. PWAT VALUES WILL ALSO INCREASE TO AROUND 2 INCHES THIS
EVENING...RESULTING IN TORRENTIAL DOWNPOURS WITH ANY STORMS. WHILE
THE NAMS 4000+ J/KG OF CAPE SEEMED A LITTLE EXCESSIVE...INSTABILITY
WILL STILL BE PLENTIFUL WITH MOST GUIDANCE SUGGESTING VALUES OF
3000-4000 J/KG SOUTH OF I-88. THE 0-6 KM SHEAR IN EXCESS OF 50 KTS
AND STEEP LAPSE RATES ALOFT LOOK VERY FAVORABLE FOR ORGANIZED
STORMS CAPABLE OF SEVERE WEATHER...NAMELY WINDS AND HAIL...IN
CENTRAL ILLINOIS INCLUDING THE SOUTHERN FORECAST AREA. THE 0-1 KM
SHEAR IS MAXIMIZED OVER THE FAR SOUTHERN PORTION OF THE
CWA...SOUTH OF A PONTIAC TO RENSSELAER LINE. SPC MENTIONS A CHANCE
FOR TORNADOES IN THE SAME AREA...BUT THINKING TORNADOES WILL NOT
BE THE MAIN THREAT. ONCE AGAIN HEAVY RAIN WILL BE A PRIMARY THREAT
ALONG WITH DAMAGING WINDS AND LARGE HAIL.
HAVE MEDIUM CONFIDENCE IN TIMING AND CONVECTIVE MODE. HAVE POPS
INCREASING FROM THE EARLY AFTERNOON THROUGH THIS EVENING PRIMARILY
ALONG AND SOUTH OF I-80. THE BEST CHANCE FOR STORMS WILL BE THIS
EVENING INTO TONIGHT AS FORCING IS MAXIMIZED AHEAD OF THE LOW AND
ITS COLD FRONT. COULD SEE SOME ISOLATED STORMS AT FIRST IN THIS
AREA...MAYBE EVEN SUPERCELLS...BUT THE MAIN SHOW SHOULD BE A LINE
OR STORM COMPLEX SOUTH OF I-80 THIS EVENING.
FINALLY...LOWERED HIGH TEMPS TODAY AS EXPECTING THICK OVERCAST SKIES
TO REMAIN IN PLACE. THE CLOUDS WILL LIMIT HEATING AND INSTABILITY.
BASED ON 850 MB TEMPS ALONE...HOWEVER...STILL THINKING WE WILL
EASILY MAKE IT INTO THE MID TO UPPER 80S TODAY. IF CLOUDS THIN...WE
COULD SEE SPOTS REACH 90 DEGREES.
SUNDAY...
THE UPPER LEVEL LOW WEAKENS AND BECOMES AN OPEN WAVE OVER LAKE MI
SUNDAY AND WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH
THROUGH THE REST OF THE WEEK. THE SURFACE PLAINS LOW ALSO WEAKENS
AND MERGES WITH THE CANADIAN LOW...AND THEN SHIFT EAST TO OVER NEW
ENGLAND MONDAY MORNING. A SECOND COLD FRONT MOVES THROUGH THE REGION
SUNDAY AFTERNOON/EVENING USHERING IN ANOTHER ROUND OF WELL BELOW
NORMAL TEMPERATURES.
EXPECTING SHOWERS AND STORMS TO FORM OVER THE LAKE SUNDAY MORNING AS
THE UPPER LEVEL LOW MOVES OVER WI. BANDS OF VORTICITY ASSOCIATED
WITH THE LOW WILL PROVIDE LIFT FOR SCATTERED STORM DEVELOPMENT
ACROSS MOST OF THE FORECAST AREA SUNDAY AFTERNOON. SEVERE STORMS
ARE NOT EXPECTED AS INSTABILITY WILL BE WEAK.
HIGH TEMPS WILL GET INTO THE LOW TO MID 80S...BUT WILL FEEL TEMPS
FALL QUICKLY BEHIND THE COLD FRONT LATE SUNDAY AFTERNOON/EVENING.
OVERNIGHT LOWS WILL BE AROUND 60.
MONDAY THROUGH FRIDAY...
WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH NEXT WEEK AND A
SURFACE HIGH MOVES OVER THE REGION TUESDAY. IN GENERAL LOOKING AT
BELOW NORMAL TEMPS THAT SLOWLY WARM TO AROUND 80 BY THE END OF NEXT
WEEK. HAVE A FEW PERIODS OF SHOWERS AND STORMS IN THE
EXTENDED...BUT THINKING STORMS WILL BE VERY DIURNAL. ALSO NOT
EXPECTING A TON OF ACTIVITY...AS THE FORCING SOURCE WILL BE WEAK
VORTICITY STREAMERS THAT TRAVEL AROUND THE UPPER LEVEL TROUGH.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* LOW CHANCE ISOLATED SHRA/TSRA THIS AFTERNOON. GREATER TSRA
POTENTIAL REMAINS SOUTH OF AREA INTO CENTRAL IL LATE THIS
AFTERNOON/EVENING.
* LIGHT AND SOMEWHAT VARIABLE SFC WINDS INTO TONIGHT. SOME CHANCE
OF LAKE BREEZE AND SHIFT TO AN EASTERLY DIRECTION MID/LATE
AFTERNOON.
* POTENTIAL FOR MVFR VIS IN FOG DEVELOPMENT OVERNIGHT.
* LOW CHANCE SHRA/TSRA AROUND SUNRISE SUNDAY...AND AGAIN SUNDAY
AFTERNOON.
* WINDS BECOMING WEST-NORTHWEST SUNDAY MORNING AND INCREASING IN
STRENGTH. GUSTS 25-30 KT LIKELY BY EARLY/MID AFTERNOON.
RATZER
//DISCUSSION...UPDATED 18Z...
COMPLICATED AND RATHER LOW CONFIDENCE FORECAST THROUGH TONIGHT
ESPECIALLY WITH RESPECT TO WIND DIRECTION AND SHRA/TSRA COVERAGE.
DISSIPATING SURFACE COLD FRONT WAS ACROSS THE FORECAST AREA FROM
FAR NORTHEAST IL TO FAR NORTHERN MISSOURI THIS AFTERNOON. WEAK
PRESSURE GRADIENT IN THE VICINITY OF THIS BOUNDARY WAS PRODUCING
RELATIVELY LIGHT/VARIABLE SURFACE WINDS...THOUGH LIGHT WESTERLY
WINDS WERE AT THE TOP/ABOVE SHALLOW SURFACE MIXED LAYER. LAKE
BREEZE WAS DEVELOPING ACROSS EASTERN LAKE/NORTHEAST COOK COUNTY...
THOUGH TDWR IMAGERY INDICATES THAT IT HAS SLOWED ITS WEST-
SOUTHWESTWARD PUSH NORTH OF DOWNTOWN CHICAGO...AND MOST HIGH-RES
MODEL GUIDANCE DOES NOT BRING IT AS FAR INLAND INTO ORD/MDW.
MVFR CIGS HAD DEVELOPED LATE MORNING WITH DIURNAL MIXING OF
SHALLOW MOIST BOUNDARY LAYER...THOUGH SOME SCATTERING AND LIFTING
OF THIS LOWEST LAYER OCCURRING PER SATELLITE/SFC OBS. FORECAST
SOUNDINGS ALSO DEPICT DRYING AND MIXING ABOVE BASE OF STRONG
INVERSION NEAR 2500 FT THROUGH THE AFTERNOON SUGGESTING MVFR CIGS
WILL NOT PERSIST. OTHER CONCERN IS THE POTENTIAL FOR SHRA/TSRA
DEVELOPMENT AS A MID-LEVEL DISTURBANCE TRACKS SOUTHEAST ACROSS THE
AREA THIS AFTERNOON. FORECAST SOUNDINGS INDICATE AFOREMENTIONED
INVERSION WOULD PROVIDE STRONG CAPPING FOR SURFACE BASED
PARCELS...THOUGH STEEP MID/UPPER LEVEL LAPSE RATES WOULD SUPPORT
SUBSTANTIAL INSTABILITY IF TAPPED. HIGH-RES GUIDANCE DOES DEPICT
SOME LIMITED DEVELOPMENT ACROSS THE AREA DURING THE AFTERNOON WITH
SUPPORT FROM RECENT RADAR TRENDS...THOUGH CONVECTION IS EXPECTED
TO STRUGGLE ACROSS TERMINALS WITH LOW CONFIDENCE IN COVERAGE.
STRONG/SEVERE THUNDERSTORMS ARE MUCH MORE LIKELY TO AFFECT
PORTIONS OF CENTRAL IL LATE THIS AFTERNOON/EVENING...EVOLVING EAST
FROM CURRENT TSRA COMPLEX SEEN OVER NORTHERN MO. MOIST LOW LEVEL
ENVIRONMENT AND LIGHT WINDS MAY SUPPORT FOG OR LOW STRATUS
DEVELOPMENT LATER TONIGHT...THOUGH MID/HIGH CLOUD COVER IS
EXPECTED TO LIMIT DEVELOPMENT SOMEWHAT.
STRONGER MID-LEVEL SYSTEM DIGS SOUTHEAST ACROSS THE REGION EARLY
SUNDAY ACCOMPANIED BY A STRONGER COLD FRONTAL PUSH. SOME POTENTIAL
WILL EXIST FOR SHRA/TSRA AROUND 12Z WITH THIS FRONT...THOUGH POOR
DIURNAL TIMING SUGGESTS LOW COVERAGE AT THAT HOUR AND PRECLUDES
MENTION IN TAF AT THIS TIME. SAME WITH POTENTIAL FOR INSTABILITY
SHOWERS LATER SUNDAY AFTERNOON. COLD ADVECTION BEHIND STRONGER
FRONT DOES DEEPEN THE MIXED LAYER SUNDAY...WITH WINDS SHIFTING
WEST-NORTHWEST AND BECOMING FAIRLY GUSTY NEAR 30 KT IN THE
AFTERNOON.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* LOW CONFIDENCE IN SHRA/TSRA DIRECTLY AFFECTING ORD/MDW THROUGH
PERIOD.
* LOW CONFIDENCE IN WIND DIRECTION THIS AFTERNOON AND TONIGHT...
THOUGH HIGH CONFIDENCE IN PREVAILING SPEEDS LESS THAN 10 KT.
* LOW CONFIDENCE IN FOG AND LOW CIGS TONIGHT.
* HIGH CONFIDENCE IN WEST-NORTHWEST WINDS BECOMING GUSTY SUNDAY.
RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
12Z...
SUNDAY NIGHT...SLIGHT CHANCE OF SHRA IN THE EVE.
MONDAY...VFR. GUSTY NORTH-NORTHEAST WINDS.
TUESDAY...VFR.
WEDNESDAY-FRIDAY...SLIGHT CHANCE OF TSRA.
MTF
&&
.MARINE...
230 PM CDT
AN ACTIVE PERIOD OF WEATHER IS SETTING UP FOR LAKE MICHIGAN FOR
THE NEXT FEW DAYS. A DIFFUSE AREA OF LOW PRESSURE OVER THE LAKE
THIS AFTERNOON WILL KEEP WINDS RELATIVELY LIGHT AND VARIABLE...BUT
A DEEPENING LOW PRESSURE SYSTEM DROPPING THROUGH THE UPPER
MISSISSIPPI VALLEY WILL LEAD TO STRENGTHENING SOUTHERLY WINDS
OVERNIGHT TONIGHT. THE LOW IS EXPECTED TO TRACK ACROSS CENTRAL
LAKE MICHIGAN LATE TONIGHT OR EARLY SUNDAY MORNING...DRAGGING A
STRONG COLD FRONT ACROSS THE LAKE AND TURNING WINDS NORTHERLY.
WINDS SHOULD QUICKLY INCREASE TO ARND 30 KT FOLLOWING THE LOW
PASSAGE AND FROPA AND DURING THE PERIOD OF STRONGEST COLD
ADVECTION...THE SEVERAL HOURS AFTER THE PASSAGE OF THE LOW AND
COLD FRONT...OCCASIONAL GALE FORCE GUSTS WILL BE POSSIBLE. WILL
ISSUE A SMALL CRAFT ADVISORY FOR THE NEAR SHORE WATERS FOR SUNDAY
MORNING THROUGH LATE MONDAY NIGHT FOR THE ILLINOIS NEARSHORE
WATERS AND SUNDAY MORNING THROUGH EARLY TUESDAY MORNING FOR THE
INDIANA WATERS AS WINDS AND WAVES WILL BOTH EXCEED ADVISORY
CRITERIA...WITH WAVES IN THE INDIANA NEAR SHORE WATERS REACHING AS
HIGH AS 7 TO 10 FT WITH OCCASIONAL HIGHER WAVES. A NORTHWESTERLY
TO NORTHERLY FETCH OVER THE ILLINOIS WATERS WILL KEEP WAVES A BIT
LOWER...BUT SHOULD EXCEED 4-5 FT BY THE END OF THE 5NM NEARSHORE
FETCH. HIGH PRESSURE BUILDING ACROSS CENTRAL PLAINS TO THE WESTERN
GREAT LAKES BY MONDAY AFTERNOON AND EVENING SHOULD ALLOW WINDS
AND WAVES TO SUBSIDE OVER THE LAKE. AS THE HIGH SETTLES INTO THE
OHIO VALLEY TUESDAY NIGHT AND WEDNESDAY...ANOTHER LOW PRESSURE
SYSTEM DROPPING SOUTHEAST THROUGH ONTARIO DRAGGING ANOTHER COLD
FRONT DOWN THE LAKE. THIS COMBINATION SHOULD KEEP MODEST WEST TO
NORTHWEST WINDS OVER THE LAKE THROUGH MIDWEEK. ANOTHER AREA OF
SPRAWLING HIGH PRESSURE IS FORECAST TO SPREAD ACROSS THE WESTERN
GREAT LAKES REGION BY LATE IN THE WEEK...BRING BACK LIGHT AND
VARIABLE WINDS AND LOW WAVES FOR LATE IN THE WEEK AND POSSIBLY
INTO NEXT WEEKEND.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014...NOON SUNDAY TO 11 PM
MONDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...NOON SUNDAY TO 5 AM
TUESDAY.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...NOON SUNDAY TO 11
PM MONDAY.
SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...NOON SUNDAY TO 5
AM TUESDAY.
&&
$$
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[top]
Area Forecast Discussion
National Weather Service Lincoln IL
157 PM CDT Sat Jul 26 2014
.DISCUSSION...
ISSUED 150 PM CDT Sat Jul 26 2014
ILX Local objective analysis as of 18z indicating the cap holding
strong across our northern forecast area where the frontal boundary
has slipped south of early this afternoon. Further south, we have
seen the cap weaken with Mixed Layer Cins down to around 100 along
the I70 corridor with Mixed Layer Capes were up to 3800 j/kg over
far west central IL where temps have climbed into the upper 80s
with dew points in the mid to upper 70s. 18z sounding from ILX and
DVN showing some moisture around 2500-3000 feet with a dry layer
from 850 to 500 mb and the cap holding strong at both locations.
SHORT TERM...Tonight through Tuesday
Storm coverage tonight the main forecast issue as all models weaken
the cap significantly this evening as the main upper level energy
starts to push into the region accompanied by cooling temperatures
aloft. HRRR and WRF-HOP ensembles were indicating the main convection
would be tracking across northern Missouri and into central to southeast
Illinois late this afternoon and evening, along the differential heating
boundary set up by the lower cloud cover. Further south, nothing but
sunshine and temps in the low to mid 90s, so quite a contrast across
central thru southeast Illinois which many times these storms tend to
propagate through. If the cap is breached there is plenty of CAPE and
Shear to interact with this evening with a fast moving QLCS still looking
more likely at least over our southern half of the forecast this evening.
Damaging winds and large hail will be the primary threats but enough
low level shear prevalent, especially near the boundary across our
northern counties, that a tornado could develop with a persistent
rotating updraft. Some of the storms could start to back-build later
this evening as the low level jet starts to back more into a southwest
to west direction increasing the threat for locally heavy rainfall.
Storms should start to edge out of our forecast area Sunday morning
as the front settles to our southeast by afternoon. Will still keep
low chance pops going, especially across the east but some fairly
decent dry air will be advecting in on a gusty west to northwest
wind during the afternoon. Cooler and much less humid air will filter
southeast into our area Monday and Tuesday as an unseasonably deep
trof settles in north of the Great Lakes.
LONG TERM...Wednesday through Saturday
The deep h5 trof will be the main weather story for much of this
period bringing rather cool temperatures for the first few days of
August, although latest guidance was not quite as cool as previous
runs as we see daytime highs edge back to or just above 80 degrees
starting on Wednesday. Rain chances remain a challenge as models
diverge with respect to timing of individual shortwaves that drop
southeast into the region bringing mainly diurnally driven shower
and thunderstorm chances, especially on Friday and Saturday.
Smith
&&
.AVIATION...
ISSUED 1259 PM CDT Sat Jul 26 2014
Main concern with forecast is timing of thunderstorms that
potentially could be strong to severe late this afternoon into
mid evening. Leaned on the HRRR model for timing of convection
which appears to have a good handle on convection over MO. Have
22-24Z timing for western TAF sites of PIA and SPI, 23-01Z for DEC
and BMI and 00-02Z for CMI. Kept strong wind gusts of 35-40 kts
with thunderstorms and vsbys 1-3 miles with heavy rains and MVFR
ceilings. Convection currently moving east into central/nw MO.
Frontal boundary over nw IL nw of the IL river could develop
convection sooner this afternoon at PIA so will monitor this.
Otherwise frontal boundary to push se through central IL into this
evening with sw winds of 7-12 kts and few higher gusts turn WSW
this evening and lighten up to 4-7 kts and veern WNW and increase
to 10-15 kts Sunday morning with gusts 15-20 kts after 15Z/10 am.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
120 PM CDT SAT JUL 26 2014
.DISCUSSION...
1150 AM...LATE MORNING UPDATE...TWO FEATURES OF NOTE LATE THIS
MORNING...A WEAK WAVE OVER SOUTHERN MN THAT WILL MOVE ACROSS THE
AREA THIS AFTERNOON AND WHAT IS EXPECTED TO BE THE MAIN WAVE
CURRENTLY OVER NORTHEAST KS MOVING INTO NORTHWEST MO. FORECAST
SOUNDINGS SHOW A FAIRLY STRONG CAP ACROSS MUCH OF THE AREA INTO
THIS AFTERNOON AND WHILE SHORT TERM/HI RES GUIDANCE DOES SUGGEST
SOME ISOLATED ACTIVITY IS POSSIBLE...APPEARS MUCH OF THE AREA WILL
REMAIN DRY INTO THIS AFTERNOON.
THUNDERSTORMS DEVELOPING OVER NORTHWEST MO WILL CONTINUE MOVING
EAST THIS AFTERNOON AND ACROSS A VERY UNSTABLE/MOIST ATMOSPHERE.
THIS ACTIVITY IS EXPECTED TO CONTINUE EAST AND ACROSS THE
SOUTHERN CWA LATE THIS AFTERNOON OR MORE LIKELY DURING THE EVENING
HOURS. NO CHANGES TO PREVIOUS THOUGHTS ON SEVERE POTENTIAL WITH A
LINE OF STORMS WITH THE POTENTIAL FOR WIDESPREAD DAMAGING WINDS
THE MOST LIKELY THREAT. HOW FAR NORTH THIS LINE EXTENDS IS STILL A
BIT UNCERTAIN AND WHILE IT WILL LIKELY REMAIN SOUTH OF I-80...
COULD BE EVEN FURTHER SOUTH...PERHAPS SOUTH OF THE KANKAKEE RIVER.
OTHERWISE...EXTENSIVE CLOUD COVER IS SLOWING THE WARMING TREND.
WITH VERY WARM LOW LEVELS...A FEW HOURS OF SUN...IF THAT WERE TO
OCCUR...COULD PUSH TEMPS TO CURRENT FORECAST HIGHS OF MID 80S...SO
NO LARGE CHANGES TO HIGHS BUT TEMP TRENDS WILL REQUIRE UPDATES.
CMS
//PREV DISCUSSION...
322 AM CDT
SYNOPSIS...UNSETTLED WEATHER IS EXPECTED TODAY WITH SEVERE STORMS
POSSIBLE ALONG AND SOUTH OF I-80. COOLER CONDITIONS MOVE IN
TOMORROW AND PERSIST THROUGH THE REST OF THE WEEK.
TODAY AND TONIGHT...
SHOWERS HAVE SPROUTED OVER NORTHWEST AND NORTH CENTRAL IL EARLY
THIS MORNING AT THE NOSE OF THE LOW LEVEL JET. EXPECTING SHOWERS
AND A FEW THUNDERSTORMS TO FESTER SOUTH OF I-88 BEFORE PUSHING
EAST OF THE WARNING AREA BY MID MORNING. NOT EXPECTING ANY SEVERE
WEATHER WITH THESE SHOWERS AND STORMS AS A SIGNIFICANT CAP IS IN
PLACE ALONG WITH LIMITED INSTABILITY.
UPPER LEVEL HIGH PRESSURE REMAINS OVER THE SOUTHERN U.S. AND IT IS
STILL EXPECTED TO RETROGRADE OVER THE SW U.S. BY MONDAY NIGHT. THE
UPPER LEVEL LOW OVER SOUTHERN SASKATCHEWAN WILL MOVE OVER WI SUNDAY
MORNING. AT THE SURFACE...THE LOW OVER THE PLAINS IS SLOWLY
TREKKING EAST AND WILL MOVE OVER CENTRAL IL TONIGHT. THE SECOND LOW
OVER SOUTHERN SASKATCHEWAN WILL SLIDE SOUTHEAST AND MOVE OVER LAKE
MI SUNDAY MORNING.
A WARM FRONT IS OVER CENTRAL MISSOURI AND IT WILL MOVE NORTH INTO
THE SOUTHERN FORECAST AREA THIS MORNING. DEW POINTS WILL RISE INTO
THE 70S. PWAT VALUES WILL ALSO INCREASE TO AROUND 2 INCHES THIS
EVENING...RESULTING IN TORRENTIAL DOWNPOURS WITH ANY STORMS. WHILE
THE NAMS 4000+ J/KG OF CAPE SEEMED A LITTLE EXCESSIVE...INSTABILITY
WILL STILL BE PLENTIFUL WITH MOST GUIDANCE SUGGESTING VALUES OF
3000-4000 J/KG SOUTH OF I-88. THE 0-6 KM SHEAR IN EXCESS OF 50 KTS
AND STEEP LAPSE RATES ALOFT LOOK VERY FAVORABLE FOR ORGANIZED
STORMS CAPABLE OF SEVERE WEATHER...NAMELY WINDS AND HAIL...IN
CENTRAL ILLINOIS INCLUDING THE SOUTHERN FORECAST AREA. THE 0-1 KM
SHEAR IS MAXIMIZED OVER THE FAR SOUTHERN PORTION OF THE
CWA...SOUTH OF A PONTIAC TO RENSSELAER LINE. SPC MENTIONS A CHANCE
FOR TORNADOES IN THE SAME AREA...BUT THINKING TORNADOES WILL NOT
BE THE MAIN THREAT. ONCE AGAIN HEAVY RAIN WILL BE A PRIMARY THREAT
ALONG WITH DAMAGING WINDS AND LARGE HAIL.
HAVE MEDIUM CONFIDENCE IN TIMING AND CONVECTIVE MODE. HAVE POPS
INCREASING FROM THE EARLY AFTERNOON THROUGH THIS EVENING PRIMARILY
ALONG AND SOUTH OF I-80. THE BEST CHANCE FOR STORMS WILL BE THIS
EVENING INTO TONIGHT AS FORCING IS MAXIMIZED AHEAD OF THE LOW AND
ITS COLD FRONT. COULD SEE SOME ISOLATED STORMS AT FIRST IN THIS
AREA...MAYBE EVEN SUPERCELLS...BUT THE MAIN SHOW SHOULD BE A LINE
OR STORM COMPLEX SOUTH OF I-80 THIS EVENING.
FINALLY...LOWERED HIGH TEMPS TODAY AS EXPECTING THICK OVERCAST SKIES
TO REMAIN IN PLACE. THE CLOUDS WILL LIMIT HEATING AND INSTABILITY.
BASED ON 850 MB TEMPS ALONE...HOWEVER...STILL THINKING WE WILL
EASILY MAKE IT INTO THE MID TO UPPER 80S TODAY. IF CLOUDS THIN...WE
COULD SEE SPOTS REACH 90 DEGREES.
SUNDAY...
THE UPPER LEVEL LOW WEAKENS AND BECOMES AN OPEN WAVE OVER LAKE MI
SUNDAY AND WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH
THROUGH THE REST OF THE WEEK. THE SURFACE PLAINS LOW ALSO WEAKENS
AND MERGES WITH THE CANADIAN LOW...AND THEN SHIFT EAST TO OVER NEW
ENGLAND MONDAY MORNING. A SECOND COLD FRONT MOVES THROUGH THE REGION
SUNDAY AFTERNOON/EVENING USHERING IN ANOTHER ROUND OF WELL BELOW
NORMAL TEMPERATURES.
EXPECTING SHOWERS AND STORMS TO FORM OVER THE LAKE SUNDAY MORNING AS
THE UPPER LEVEL LOW MOVES OVER WI. BANDS OF VORTICITY ASSOCIATED
WITH THE LOW WILL PROVIDE LIFT FOR SCATTERED STORM DEVELOPMENT
ACROSS MOST OF THE FORECAST AREA SUNDAY AFTERNOON. SEVERE STORMS
ARE NOT EXPECTED AS INSTABILITY WILL BE WEAK.
HIGH TEMPS WILL GET INTO THE LOW TO MID 80S...BUT WILL FEEL TEMPS
FALL QUICKLY BEHIND THE COLD FRONT LATE SUNDAY AFTERNOON/EVENING.
OVERNIGHT LOWS WILL BE AROUND 60.
MONDAY THROUGH FRIDAY...
WE REMAIN ON THE WEST SIDE OF THE UPPER LEVEL TROUGH NEXT WEEK AND A
SURFACE HIGH MOVES OVER THE REGION TUESDAY. IN GENERAL LOOKING AT
BELOW NORMAL TEMPS THAT SLOWLY WARM TO AROUND 80 BY THE END OF NEXT
WEEK. HAVE A FEW PERIODS OF SHOWERS AND STORMS IN THE
EXTENDED...BUT THINKING STORMS WILL BE VERY DIURNAL. ALSO NOT
EXPECTING A TON OF ACTIVITY...AS THE FORCING SOURCE WILL BE WEAK
VORTICITY STREAMERS THAT TRAVEL AROUND THE UPPER LEVEL TROUGH.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* LOW CHANCE ISOLATED SHRA/TSRA THIS AFTERNOON. GREATER TSRA
POTENTIAL REMAINS SOUTH OF AREA INTO CENTRAL IL LATE THIS
AFTERNOON/EVENING.
* LIGHT AND SOMEWHAT VARIABLE SFC WINDS INTO TONIGHT. SOME CHANCE
OF LAKE BREEZE AND SHIFT TO AN EASTERLY DIRECTION MID/LATE
AFTERNOON.
* POTENTIAL FOR MVFR VIS IN FOG DEVELOPMENT OVERNIGHT.
* LOW CHANCE SHRA/TSRA AROUND SUNRISE SUNDAY...AND AGAIN SUNDAY
AFTERNOON.
* WINDS BECOMING WEST-NORTHWEST SUNDAY MORNING AND INCREASING IN
STRENGTH. GUSTS 25-30 KT LIKELY BY EARLY/MID AFTERNOON.
RATZER
//DISCUSSION...UPDATED 18Z...
COMPLICATED AND RATHER LOW CONFIDENCE FORECAST THROUGH TONIGHT
ESPECIALLY WITH RESPECT TO WIND DIRECTION AND SHRA/TSRA COVERAGE.
DISSIPATING SURFACE COLD FRONT WAS ACROSS THE FORECAST AREA FROM
FAR NORTHEAST IL TO FAR NORTHERN MISSOURI THIS AFTERNOON. WEAK
PRESSURE GRADIENT IN THE VICINITY OF THIS BOUNDARY WAS PRODUCING
RELATIVELY LIGHT/VARIABLE SURFACE WINDS...THOUGH LIGHT WESTERLY
WINDS WERE AT THE TOP/ABOVE SHALLOW SURFACE MIXED LAYER. LAKE
BREEZE WAS DEVELOPING ACROSS EASTERN LAKE/NORTHEAST COOK COUNTY...
THOUGH TDWR IMAGERY INDICATES THAT IT HAS SLOWED ITS WEST-
SOUTHWESTWARD PUSH NORTH OF DOWNTOWN CHICAGO...AND MOST HIGH-RES
MODEL GUIDANCE DOES NOT BRING IT AS FAR INLAND INTO ORD/MDW.
MVFR CIGS HAD DEVELOPED LATE MORNING WITH DIURNAL MIXING OF
SHALLOW MOIST BOUNDARY LAYER...THOUGH SOME SCATTERING AND LIFTING
OF THIS LOWEST LAYER OCCURRING PER SATELLITE/SFC OBS. FORECAST
SOUNDINGS ALSO DEPICT DRYING AND MIXING ABOVE BASE OF STRONG
INVERSION NEAR 2500 FT THROUGH THE AFTERNOON SUGGESTING MVFR CIGS
WILL NOT PERSIST. OTHER CONCERN IS THE POTENTIAL FOR SHRA/TSRA
DEVELOPMENT AS A MID-LEVEL DISTURBANCE TRACKS SOUTHEAST ACROSS THE
AREA THIS AFTERNOON. FORECAST SOUNDINGS INDICATE AFOREMENTIONED
INVERSION WOULD PROVIDE STRONG CAPPING FOR SURFACE BASED
PARCELS...THOUGH STEEP MID/UPPER LEVEL LAPSE RATES WOULD SUPPORT
SUBSTANTIAL INSTABILITY IF TAPPED. HIGH-RES GUIDANCE DOES DEPICT
SOME LIMITED DEVELOPMENT ACROSS THE AREA DURING THE AFTERNOON WITH
SUPPORT FROM RECENT RADAR TRENDS...THOUGH CONVECTION IS EXPECTED
TO STRUGGLE ACROSS TERMINALS WITH LOW CONFIDENCE IN COVERAGE.
STRONG/SEVERE THUNDERSTORMS ARE MUCH MORE LIKELY TO AFFECT
PORTIONS OF CENTRAL IL LATE THIS AFTERNOON/EVENING...EVOLVING EAST
FROM CURRENT TSRA COMPLEX SEEN OVER NORTHERN MO. MOIST LOW LEVEL
ENVIRONMENT AND LIGHT WINDS MAY SUPPORT FOG OR LOW STRATUS
DEVELOPMENT LATER TONIGHT...THOUGH MID/HIGH CLOUD COVER IS
EXPECTED TO LIMIT DEVELOPMENT SOMEWHAT.
STRONGER MID-LEVEL SYSTEM DIGS SOUTHEAST ACROSS THE REGION EARLY
SUNDAY ACCOMPANIED BY A STRONGER COLD FRONTAL PUSH. SOME POTENTIAL
WILL EXIST FOR SHRA/TSRA AROUND 12Z WITH THIS FRONT...THOUGH POOR
DIURNAL TIMING SUGGESTS LOW COVERAGE AT THAT HOUR AND PRECLUDES
MENTION IN TAF AT THIS TIME. SAME WITH POTENTIAL FOR INSTABILITY
SHOWERS LATER SUNDAY AFTERNOON. COLD ADVECTION BEHIND STRONGER
FRONT DOES DEEPEN THE MIXED LAYER SUNDAY...WITH WINDS SHIFTING
WEST-NORTHWEST AND BECOMING FAIRLY GUSTY NEAR 30 KT IN THE
AFTERNOON.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* LOW CONFIDENCE IN SHRA/TSRA DIRECTLY AFFECTING ORD/MDW THROUGH
PERIOD.
* LOW CONFIDENCE IN WIND DIRECTION THIS AFTERNOON AND TONIGHT...
THOUGH HIGH CONFIDENCE IN PREVAILING SPEEDS LESS THAN 10 KT.
* LOW CONFIDENCE IN FOG AND LOW CIGS TONIGHT.
* HIGH CONFIDENCE IN WEST-NORTHWEST WINDS BECOMING GUSTY SUNDAY.
RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
12Z...
SUNDAY NIGHT...SLIGHT CHANCE OF SHRA IN THE EVE.
MONDAY...VFR. GUSTY NORTH-NORTHEAST WINDS.
TUESDAY...VFR.
WEDNESDAY-FRIDAY...SLIGHT CHANCE OF TSRA.
MTF
&&
.MARINE...
217 AM CDT
AN ACTIVE PERIOD FOR SUMMERTIME IS UPCOMING OVER THE LAKE BUT FIRST
TODAY AND TONIGHT WILL SEE SOUTHERLY WINDS AHEAD OF AN APPROACHING
SURFACE LOW. WINDS ACTUALLY LOOK TO BE LIGHT ENOUGH IN INDIANA AND
ILLINOIS NEARSHORE ZONES TO ALLOW FOR A LAKE BREEZE TO DEVELOP
FOR TEMPORARY AFTERNOON ONSHORE FLOW. THE SURFACE LOW WILL EVOLVE
EASTWARD OVER THE MIDDLE OF THE LAKE ON SUNDAY MORNING WITH COOL
AIR ADVECTION ENVELOPING THE LAKE BY LATE IN THE DAY AND
ESPECIALLY IN THE EVENING. NORTHERLY WINDS WITHIN UNSTABLE
THERMAL PROFILES OVER THE WATER WILL SUPPORT 20-25 KT SUSTAINED
WINDS WITH POTENTIALLY SOME GUSTS KNOCKING ON THE DOOR TO GALE
STRENGTH SUNDAY NIGHT AND EARLY MONDAY. WAVES ARE LIKELY TO BUILD
WHERE THEY WERE WITH THE LAST COOL ADVECTION EPISODE EARLIER THIS
WEEK /WEDNESDAY/...BOTH OVER THE OPEN WATERS AND NEARSHORE AREAS
OF ILLINOIS AND INDIANA. THE FLOW WILL DIMINISH INTO TUESDAY BUT
CONTINUE FROM THE NORTH BEFORE HIGH PRESSURE SETTLES IN MIDWEEK.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
100 PM CDT Sat Jul 26 2014
.DISCUSSION...
ISSUED 1045 AM CDT Sat Jul 26 2014
Update the forecast to include the mention of severe thunderstorms
possible late this afternoon sw counties and across area this evening.
SPC has moderate risk of severe storms late this afternoon and
evening across central IL except slight risk over Stark, Marshall
and northern Knox counties. Has 5% risk of tornadoes, 30% risk of
large hail (10% risk of 2 inch or larger hail) and 45% risk of
damaging wind gusts.
Also trended pops lower through early afternoon and higher late
this afternoon and evening. Most of central IL has been dry so far
this morning. Low clouds have spread into nw counties by late
morning and this may limit heating and instability. Kept highs in
the upper 80s and lower 90s with afternoon heat indices peaking
from 95 to 103F, lowest north of Peoria where more low clouds found.
A frontal boundary over NW IL and near the IA/MO border will press
se into central IL later this afternoon and tonight and collide
with an increasingly unstable airmass with CAPES projects to
surpass 3000 j/kg and bulk shear rising to 40-50 kts by 00Z/7 pm.
07
&&
.AVIATION...
ISSUED 1259 PM CDT Sat Jul 26 2014
Main concern with forecast is timing of thunderstorms that
potentially could be strong to severe late this afternoon into
mid evening. Leaned on the HRRR model for timing of convection
which appears to have a good handle on convection over MO. Have
22-24Z timing for western TAF sites of PIA and SPI, 23-01Z for DEC
and BMI and 00-02Z for CMI. Kept strong wind gusts of 35-40 kts
with thunderstorms and vsbys 1-3 miles with heavy rains and MVFR
ceilings. Convection currently moving east into central/nw MO.
Frontal boundary over nw IL nw of the IL river could develop
convection sooner this afternoon at PIA so will monitor this.
Otherwise frontal boundary to push se through central IL into this
evening with sw winds of 7-12 kts and few higher gusts turn WSW
this evening and lighten up to 4-7 kts and veern WNW and increase
to 10-15 kts Sunday morning with gusts 15-20 kts after 15Z/10 am.
07
&&
.PREV DISCUSSION...
ISSUED 312 AM CDT Sat Jul 26 2014
Unsettled weather anticipated today as low pressure and associated
fronts make their way through the Midwest. Plenty of fuel for
storms as hot and humid air pools over the region, but there is
much derision in the models as to initiation and timing and
location of waves to the west to move along the boundaries in the
region and trigger the storms/MCS that will bring the potential
for severe weather to Central Illinois. Warm front currently to
the southwest and expected to lift into the area today, leaving
ILX in the warm sector for much of the day. Depending on the speed
of the cold front expected this afternoon/evening will depend on
how much instability it taps into. Sfc dewpoints into the upper
60s and lower 70s just on the other side of the Miss River Valley
this morning are expected to shift eastward with high temps
approaching 90F. Beyond stormy today and tonight... remainder of
the forecast cooler behind the boundary slowly modifying through
next week to more seasonable temperatures ahead of the next system.
SHORT TERM...Today and tonight...
Plenty of instability for the area with a Moderate Risk in place
for just that reason. 18z forecast soundings showing 4000-4500 j/kg
CAPE as a reflection of the increasing moisture at the sfc and
climbing temps in the warm sector as the warm front lifts
northward. Warm front expected to be northeast and east by midday
as the cold front and actual low center makes its way into the
region. As similar situations have set up over the fa recently,
trouble will be fighting the cap in place for much of the day...
and the approach of the front being enough to break it. Not only
the front itself but models have persisted with a couple waves
moving into the region. Major issues with this are beginning to
show their hand this morning as the locations of the waves this
morning on sat imagery are not initializing in the same locations
as many of the models. Bottom line is... plenty of fuel for
storms, and the triggers are there, but timing and exact locations
of impact are troublesome at best. Llvl helicity better in the
early evening with the proximity of the cold front and the low
itself...but cannot ignore the impact of the warm front and its
location should it not progress further north, storms crossing the
boundary could also be impacted by the turning of the winds for
the front. Once the cap breaks, the forecast soundings/CAPE are
indicative of rapid development of storms. Once going, the very
high CAPE values remain in place well into the evening up to 06z.
Best directional shear is actually in place for the late
afternoon/early evening lending itself to supercells in the
beginning of the event...transitioning to more of a wind event
with time. Large hail will also be a threat mostly with supercells
and long sustained updrafts as the freezing levels are more than
15k ft. Some tornadic potential early with supercells and invof
both outflows and frontal boundaries.
LONG TERM...Tomorrow through Friday...
Event coming to a close from west to east on Sunday early...but
proximity to upper trof over the Great Lakes will keep an enhanced
threat for instability showers under cyclonic flow, esp Sunday
afternoon. Cooler temps in place for Monday in particular as 850mb
temps drop to closer to 10-12C. Moderating temperatures for the
week as northwesterly flow establishes itself in the region.
Majority of waves alluded to in the models remain north of here
and forecast remains mostly dry, though subtle shifts with those
waves could easily shift the forecast. Next major system impacting
the Midwest Thurs late into Saturday with an open wave aloft and
more cyclonic flow bringing threat for instability showers yet
again.
HJS
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1232 PM EDT SAT JUL 26 2014
.SYNOPSIS...
ISSUED AT 1052 AM EDT SAT JUL 26 2014
SHOWER AND THUNDERSTORM CHANCES WILL OVERSPREAD THE REGION TODAY
AS A FRONT APPROACHES. THIS FRONT WILL REMAIN IN THE REGION
THROUGH TONIGHT KEEPING THE SHOWER AND THUNDERSTORM CHANCES
AROUND. HIGH TEMPERATURES TODAY WILL RANGE FROM THE LOWER 80S IN
SOUTHERN MICHIGAN TO THE UPPER 80S NEAR THE OHIO RIVER. LOW
TEMPERATURES TONIGHT WILL RANGE FROM THE UPPER 60S IN SOUTHERN
MICHIGAN TO THE LOWER 70S ALONG THE OHIO RIVER.
&&
.UPDATE...
ISSUED AT 946 AM EDT SAT JUL 26 2014
FORECAST INTO THIS AFTERNOON IN PRETTY GOOD SHAPE WITH ONLY SOME
MINOR CHANGES MADE. SLOWLY INTRODUCED LOW 15-20 POPS FOR ISOLATED
SHOWERS/THUNDER INTO NORTHERN/EASTERN ZONES THIS AFTERNOON GIVEN
WEAK WAA/ISENTROPIC ASCENT AND BOUNDARY LAYER HEATING IN ADVANCE
OF A WARM FRONT AND STOUT (IA/NRN MO/WS IL) EML. THIS EML APPEARS
RATHER IMPRESSIVE ON 12Z DVN/ILX/OMX RAOBS WITH CONVECTIVE TEMPS
IN EXCESS OF 100F. THIS MAY DELAY PRIMARY CONVECTIVE COMPLEX
PROGGED TO POSSIBLY CLIP OUR SOUTHERN ZONES TO LATER TONIGHT WHEN
HEIGHT FALLS BEGIN TO OVERSPREAD THE FRONTAL BOUNDARY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 451 AM EDT SAT JUL 26 2014
NOSE OF LOW LEVEL JET FOCUS COINCIDENT WITH EASTERN PERIPHERY OF
STOUT EML BEGINNING TO DRIVE CONVECTIVE DEVELOPMENT UPSTREAM IN ARC
STRETCHING FROM EASTERN IA-NWRN IL-FAR WCNTL IN. VEERING JETLET AND
STEERING FLOW SUGGESTS MAJORITY OF SHRA TO TARGET ONLY FAR SWRN/SRN
CWA THIS AM. LACK OF APPRECIABLE LOW LEVEL MOISTURE WITH EASTERN
EXTENT SHOULD PRECLUDE ALL BUT PERHAPS AN ISOLD TSRA WITH EASTERN
EXTENT INTO CWA. SMALL CHC TSRA POPS IN DEFERENCE TO SHORT MODEL
CONSENSUS AFFORDED ACROSS ERN CWA THIS AFTN AS RIDGE OF GREATER
1000-850MB THETA-E/MOISTURE FLUX CONVERGENCE ASSERTS INTO NERN
IN/NWRN OH. DIFFERENTIAL HEATING ALONG DECAYING AM SHRA AND
STRATO/ALTOCU LAYERS AND PRESENCE OF DIFFUSE WARM FRONTAL LIMB LENDS
CREDENCE TO TREND OF OUTCOME/SOLUTIONS SEEN WITH 3KM HIGH-RES RAPID
REFRESH RUC IN THIS REGARD. WEAK LOW AMPLITUDE RIDGING SHOULD ALLOW
LOW END MENTION TO SUFFICE THROUGH TODAY. BY FAR THE GREATER
CONVECTIVE CONCERN LIES UPSTREAM AS EXTREME SERN SASK VORTEX DRIVES
SEWD INTO NRN MN EARLY TONIGHT WITH 60-70KT MID TROPOSPHERIC FLOW
ALONG SOUTHERN PERIPHERY OF WAVE. STRONG MID/UPPER LEVEL KINEMATICS
TO IMPINGE ON AREA OF SIGNIFICANT MOISTENING/HEATING BENEATH
RESIDUAL EML TO OFFER STRONG 3500-5000 J/KG SBCAPE BY 00 UTC SUN.
THIS LARGE INSTABILITY POOL PRESENTS ELONGATED E-W FROM SWRN CWA TO
MO/IA BORDER AMID 40-50 KTS DEEP LAYER BULK SHEAR. DECENT POTENTIAL
FOR MULTIPLE EPISODIC EVENING/EARLY NIGHT SUPERCELLS TO DEVELOP
UPSTREAM ACROSS CENTRAL/NCENTRAL ILLINOIS TO TRACK INTO SRN HALF OF
CWA AND TRANSITION TOWARD STRONG/SEVERE QUASI-LINEAR SEGMENTS
THROUGH SOUTHERN HALF OF CWA IN STRONG PARALLEL STORM MOTION
VECTORING. MDPI GT 1 AND DECENT /1000-1250 J/KG/ CAPE WITHIN
M10-M30C HAIL PRODUCTION ZONE WITH FAVORABLE WETBULB ZERO HEIGHTS IN
10.5-11.5 RANGE SUGGESTIVE OF MULTIPLE DAMAGING WIND EVENTS/ISOLATED
LARGE HAIL RISKS. DIFFICULTY IN SHARP DEMARCATION OF POPS WITH
EXTREMELY SHARP INSTABILITY GRADIENT WITH ONLY SLIGHT CHC MENTION
WARRANTED FAR NRN CWA RAMPING TO SIGNIFICANT/SEVERE LIKELY
POPS/SEVERE MENTION GENERALLY ALONG/S OF ROUTE 30 IN 00-09 UTC
TIMEFRAME. SOME CONCERN FOR POTENTIAL BACKBUILDING/TRAILING
STRATIFORM CONVECTION IN 06-12 UTC TIMEFRAME AS STORM MOTION VECTORS
BACK DUE WESTERLY...ALONG/PARALLEL TO TRAILING POOL OF EXTREME
1000-850MB MIXING RATIO GTE 16 G/KG THAT REACHES BACK INTO WEST
CENTRAL IL. WILL ADDRESS TERTIARY FLOODING POTENTIAL IN HWO IN
ADDITION TO DMG WIND/HAIL CONCERNS.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 451 AM EDT SAT JUL 26 2014
A WELL DEFINED UPPER LEVEL DISTURBANCE OVER SOUTHERN SASKATCHEWAN
PROVENCE EARLY THIS MORNING WILL MOVE SOUTHEAST DOWN THE BACKSIDE OF
THE UPPER LEVEL RIDGE. AS THIS SYSTEM MOVES SOUTHEAST TOWARD THE
WESTERN GREAT LAKES REGION...VERY UNSTABLE AIR WILL EXTEND INTO
NORTHERN INDIANA AND NORTHWEST OHIO EARLY SUNDAY MORNING. HIGH
ENERGY HELICITY INDEX VALUES UP TO 4.0 TO 5.0 M2/S2 REFLECT THE
POTENTIAL FOR SUPERCELL ACTIVITY OVER THE SOUTHERN THIRD OF THE
FORECAST AREA EARLY SUNDAY MORNING. SEVERE WEATHER CHANCES LOOK BEST
IN THE MORNING OVER FAR SOUTH AND SOUTHEAST AREAS. CONCERN FOR
MAINLY DAMAGING WINDS EARLY GIVEN A FAVORABLE WIND PROFILE
SIGNATURE. SEVERE WEATHER CHANCES SHOULD DIMINISH BY EARLY AFTERNOON
AS COOLER AIR SPREADS OVER THE AREA BEHIND THE FRONT. FOR THE REST
OF THE PERIOD...SOME LINGERING SHOWERS ARE POSSIBLE TONIGHT AND
MONDAY AS A POST FRONTAL TROF MOVES ACROSS THE AREA. KEPT THE REST
OF THE PERIOD DRY AS THE UPPER LEVEL TROF REMAINS OVER THE AREA. 500
MB ANALOGS SUPPORT TEMPERATURES BELOW NORMAL THIS UPCOMING WORK WEEK
WITH A PERSISTENT NEGATIVE HEIGHT ANOMALY SOUTH OF HUDSON BAY.
PREFER THE COOLER GFS/MEAN/MEX VALUES GIVEN COOL 850 MB TEMPERATURES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1232 PM EDT SAT JUL 26 2014
HIGH END MVFR/LOW VFR STRATO CU CLOUD DECK EXPECTED TO CONTINUE TO
FILL IN ACROSS NORTHERN INDIANA THIS AFTERNOON WITH LOW LEVEL
TROUGH/MOISTURE AXIS IN THE VICINITY. WARM PROFILE ALOFT LIKELY TO
KEEP THE TERMINALS CONVECTION FREE INTO EARLY THIS EVENING. EXPECT
CONVECTION INVOF REMNANT MCV AND FRONTAL BOUNDARY TO FIRE ACROSS
MO INTO WC IL LATER THIS AFTERNOON...LIKELY GROWING UPSCALE INTO A
FORWARD PROPAGATING MCS INTO IN/OH LATER TONIGHT. LATEST
SATELLITE/OB TRENDS SUGGEST THAT THE WORST OF THIS ACTIVITY MAY
PASS TO THE SOUTH OF THE TERMINALS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
UPDATE...STEINWEDEL
SYNOPSIS...LOTHAMER
SHORT TERM...MURPHY
LONG TERM...SKIPPER
AVIATION...STEINWEDEL
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AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1252 PM CDT SAT JUL 26 2014
.UPDATE...
ISSUED AT 1247 PM CDT SAT JUL 26 2014
CONSIDERABLE LOW LEVEL CLOUDS REMAIN ACROSS THE SOUTHERN PARTS OF
THE AREA AND SATELLITE TRENDS SHOW NEW MID LEVEL CLOUDS DEVELOPING
NOW ACROSS THE NORTH.
ALL OF THIS RAISES QUESTIONS REGARDING HOW CONVECTION WILL DEVELOP
THIS AFTERNOON AND EVENING. DIFFERENTIAL HEATING THAT IS OCCURRING
SHOULD RESULT IN CONVECTION EVENTUALLY DEVELOPING LATER THIS
AFTERNOON AND INTO THE EVENING HOURS.
UPDATE ISSUED AT 837 AM CDT SAT JUL 26 2014
RADAR SHOWS RETURNS MOVING INTO THE AREA THAT ARE WEAKENING WITH
TIME BUT NO REPORTS OF ANYTHING REACHING THE GROUND. SATELLITE
INDICATES PLENTY OF ACCAS AND RAP TRENDS INDICATES THE FORCING
WEAKENING OVER TIME. ADD TO THAT THE MORNING SOUNDING BEING QUITE
DRY ABOVE 800MB BRINGS DOUBTS ABOUT PRECIP CHANCES DURING THE
MORNING HOURS. OTHER THAN POSSIBLY SOME SPRINKLES...THE MORNING
PERIOD LOOKS TO BE DRY.
UPDATE ISSUED AT 745 AM CDT SAT JUL 26 2014
ADDED ISOLATED SHOWERS TO THE GRIDS THIS MORNING AS A FEW SHOWERS
IN CENTRAL IA WERE HEADED EAST INTO THE CWA. OTHERWISE NO CHANGES
TO THE GRIDS PLANNED. WE WILL BE DOING AN 18Z SPECIAL BALLOON
LAUNCH FOR THE SEVERE RISK.
&&
.SYNOPSIS...
ISSUED AT 350 AM CDT SAT JUL 26 2014
ISOLATED SHOWERS DEVELOPED AFTER MIDNIGHT IN OUR NORTHERN AND
EASTERN CWA ON THE NOSE OF A 35-40 KNOT LOW LEVEL JET. THERE IS
LOW LEVEL CONVERGENCE AND THETA-E ADVECTION BUT MOISTURE IS RATHER
LIMITED WHICH IS PREVENTING A MORE WIDESPREAD EVENT. THESE SHOWERS ARE
ALSO OCCURRING NORTHEAST OF A WARM FRONT WHICH EXTENDED ACROSS SOUTHEAST
IA AND INTO NORTHEAST ARKANSAS. 3 AM TEMPERATURES RANGED FROM THE
MID 60S TO AROUND 70 WITH DEWPOINTS RANGING FROM THE UPPER 50S IN
NW IL TO THE LOWER 70S IN WESTERN MO. EXTENSIVE LOW STRATUS WAS NOTED
NORTHEAST OF THE WARM FRONT AND COVERED MUCH OF OUR NORTHEAST HALF
OF THE CWA. SKIES WERE CLEAR TO PARTLY CLOUDY IN OUR SW CWA.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM CDT SAT JUL 26 2014
FORECAST FOCUS ON SEVERE/FLASH FLOODING POTENTIAL AND TEMPERATURES.
TODAY...ANY SHOWERS IN OUR EASTERN CWA WILL HAVE SHIFTED EAST OF
THE CWA BEFORE 6 AM SO WE WILL HAVE A DRY MORNING. LAMP DATA
SUGGESTS THE STRATUS WILL LINGER ACROSS OUR NORTHEAST CWA THROUGH
MUCH OF THE MORNING WITH THE LOW CLOUDS THEN BECOMING SCATTERED.
IN OUR SOUTHERN CWA THERE WILL BE PLENTY OF SUNSHINE SOUTH OF THE
WARM FRONT...WHICH SHOULD ADVANCE TO NEAR INTERSTATE 80 OR SO TODAY.
THIS WILL SET UP A NICE THERMAL GRADIENT WITH MAXIMUM TEMPERATURES
ALONG HIGHWAY 20 CLOSE TO 80 WHILE IN OUR FAR SOUTH READINGS SHOULD
PUSH TO AROUND 90. WITH DEWPOINTS IN OUR SOUTH RISING INTO THE
LOWER TO MID 70S HEAT INDEX VALUES WILL SOAR WELL INTO THE 90S TO
NEAR 100. TEMPERATURES WILL NEED TO BE MONITORED CLOSELY TODAY AS
CLOUD COVER (OR LACK OF) WILL HAVE AN IMPACT ON THESE READINGS
JUST LIKE YESTERDAY...WHERE READINGS WERE NOT AS WARM AS I EXPECTED.
SEVERE WEATHER...SPC HAS A MODERATE RISK IN OUR 4 SE COUNTIES WITH
A SLIGHT AS FAR NORTH AS HIGHWAY 30. CLOSED UPPER LOW IN SOUTHERN
SASKATCHEWAN DIVES SOUTHEAST INTO NORTHERN MN INCREASING DIFFLUENCE
ACROSS THE MIDWEST AND LARGE SCALE ASCENT AS HEIGHT FALLS ARRIVE.
THE LOCATION OF THE SEVERE WEATHER AND GREATEST CONCENTRATION WILL
CERTAINLY DEPEND ON WHERE THE FRONTAL BOUNDARY WILL EXIST AND
AMOUNT OF INSTABILITY. THE NAM SEEMS TOO HIGH WITH DEWPOINTS AND
CAPES BUT NONETHELESS SBCAPES SHOULD EASILY REACH 4000 J/KG IN OUR
SOUTH. HOW FAR NORTH THE SEVERE THREAT IS REALIZED WILL ONCE AGAIN
DEPEND ON CLOUD COVER AND FRONTAL POSITION. MODELS INTENSIFY MID
LEVEL WINDS TO 50+ KNOTS WHICH WILL INCREASE DEEP LAYER SHEAR WITH
SUPERCELLS INITIALLY DEVELOPING LATER THIS AFTERNOON IN OUR SOUTH
AS THE CAP WEAKENS. LARGE HAIL AND DAMAGING WINDS WILL BE THE MAIN
THREAT BUT A TORNADO OR TWO IS POSSIBLE. EVENTUALLY THIS WILL
CONGEAL INTO AN ORGANIZED MCS WITH DAMAGING WINDS THE MAIN THREAT
THIS EVENING AS IT EVENTUALLY PUSHES WELL TO THE EAST OF THE CWA.
FOR NOW HAVE MENTIONED SEVERE WORDING IN THE GRIDS IN OUR SOUTHERN
CWA LATE THIS AFTERNOON INTO THE EVENING HOURS.
FLASH FLOODING...WILL NEED TO KEEP AN EYE ON THE POTENTIAL FOR
FLASH FLOODING ESPECIALLY IN OUR FAR SOUTHERN CWA WHERE 3 TO 5
INCHES OF RAIN FELL YESTERDAY. WITH HIGH PWAT`S AGAIN THIS AFTERNOON
AND EVENING THE POTENTIAL IS CERTAINLY THERE FOR TORRENTIAL RAIN IN
A SHORT TIME. SOME OF THE RIVERS ALSO SHOWED A RAPID RESPONSE TO
THIS HEAVY RAIN BUT ARE STILL BELOW FLOOD STAGE AT THIS TIME.
OVERNIGHT...A COLD FRONT WILL THEN PUSH ACROSS THE CWA OVERNIGHT
WITH MINIMUM TEMPERATURES RANGING FROM THE LOWER 60S NW TO THE
UPPER 60S SE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 350 AM CDT SAT JUL 26 2014
VIGOROUS COMPACT UPPER LOW IS SHOWN TO DIVE SOUTHEASTWARD THROUGH THE
GREAT LAKES ON SUNDAY. ATTENDANT COLD FRONT WILL BE SWEEPING THROUGH
CWA EARLY IN THE DAY FOLLOWED BY GUSTY NORTHWEST WINDS AND LOWERING
HUMIDITY. PCPN CHANCES THUS DIMINISHING WITH FASTER FRONTAL PASSAGE
AND ONSET OF SUBSEQUENT COOL...DRY ADVECTION... BUT STILL HELD ON TO
SMALL PCPN CHANCES FAR NORTH SUNDAY AFTERNOON AHEAD OF SAGGING SURFACE
TROUGH/WIND SHIFT OVER WI.
MON-FRI...MEDIUM RANGE MODELS AND ENSEMBLES IN GOOD AGREEMENT DEPICTING
HIGHLY AMPLIFIED UPPER AIR PATTERN WITH ANOMALOUSLY DEEP TROUGH
OVER THE EASTERN HALF OF THE CONUS AND A SHARP RIDGE /HEAT DOME/ OUT
WEST. THIS WILL KEEP AREA LOCKED IN NORTHWEST FLOW ALOFT RESULTING IN
NICE STRETCH OF WEATHER NEXT WEEK GENERALLY CHARACTERIZED BY VERY
COMFORTABLE CONDITIONS WITH LOWER HUMIDITY AND BELOW NORMAL TEMPS...AND
ALSO DRIER WITH LIMITED MEASURABLE RAIN PROSPECTS...WITH POSSIBILITY
OF A FEW PM SHOWERS MAINLY LATE WEEK AS AIRMASS BEGINS TO UNDERGO GRADUAL
MODIFICATION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1247 PM CDT SAT JUL 26 2014
MVFR TO VFR CONDITIONS WILL BE SEEN ACROSS THE AREA THROUGH
03Z/27. CONVECTION IS EXPECTED TO OCCUR WITH TSRA MOST NUMEROUS IN
THE 21Z/26 TO 02Z/27 TIME FRAME WITH THE POTENTIAL FOR BRIEF IFR
CONDITIONS IN TSRA. AFT 03Z/27 VFR CONDITIONS ARE EXPECTED BUT THE
POSSIBILITY DOES EXIST OF SOME MVFR CONDITIONS DEVELOPING.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...05
AVIATION...08
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1242 PM CDT SAT JUL 26 2014
.SHORT TERM /TODAY/...
ISSUED AT 345 AM CDT SAT JUL 26 2014
RATHER COMPLEX FORECAST FOR TODAY AS CONFIDENCE OF EVOLUTION OF MESO
SCALE ONLY MODEST AT THIS TIME...BUT COULD BE AN RATHER ACTIVE
AFTERNOON AND EVENING OVER THE SOUTH. AFTER EARLY MORNING PATCHY FOG
POTENTIAL FOR SEVERE WEATHER THIS AFTERNOON FOR ABOUT THE SOUTHERN
HALF OF THE FORECAST AREA. EARLY THIS MORNING A SHORT WAVE OVER THE
SOUTHERN PLAINS AT H850 IS DRIVING WARM AIR AND RATHER HIGH MOISTURE
INTO IOWA AND SURROUNDING STATES. A LARGE POOL OF 15C DEW POINTS
EXTENDS FROM EASTERN KS... COVERING ALL OF IOWA AND NORTHERN MO AS
WELL AS EASTERN MN AND WESTERN WI. CLOUDS HAVE BEEN DEVELOPING AT
MID LEVELS OVER SOUTHERN IOWA IN RESPONSE TO THIS MOISTURE AND A
WEAK SFC BOUNDARY/ZONE OF H850 30KT LLJ MOVING ACROSS THE AREA. SO
FAR THERE IS TOO MUCH CIN TO REALLY LET ANYTHING GO AT THIS TIME.
NORTHWEST OF US A PRONOUNCED H700 SHORTWAVE CURRENTLY IN WY/MT WILL
SHIFT EAST SOUTHEAST TODAY. AHEAD OF IT A WEAKER WAVE IS PRODUCING A
SMALL AREA OF CONVECTION OVER EASTERN SOUTH DAKOTA ALONG A RATHER
MINOR TROUGH AT H850 THAT EXTENDS FROM SUPERIOR/DULUTH BACK
SOUTHWESTWARD TO HURON AND RAPID CITY. IT IS EXPECTED THAT THIS AREA
OF CONVECTION WILL WEAKEN AND CONTINUE TO MOVE SOUTHEAST AND IMPACT
NORTHERN PORTIONS OF THE FORECAST AREA THIS MORNING PRIOR TO NOON.
THE WESTERN EDGE OF THE CONVECTION THOUGH...IS EXPECTED TO INTENSIFY
BY LATE MORNING IN RESPONSE TO THE APPROACHING STRONGER H700 WAVE
AND H500 WESTERLIES INCREASING TO 50KTS BY 00Z AND H300 WINDS
NEARING 70 TO 85KTS BY 00Z OVER IOWA.
THIS MORNING A WEAK SFC LOW OVER SOUTHWEST IOWA WILL DRIFT SOUTHEAST
INTO NORTHERN MO DURING THE AFTERNOON HOURS. A PRONOUNCED 2500 TO
3500 J/KG MLCAPE MAX WILL BE OVER THE SOUTHERN TWO TIER COUNTIES BY
18Z...WITH HEATING INCREASING INSTABILITY TO 3500 J/KG NEAR DES
MOINES TO 5500 J/KG JUST SOUTH OF THE IA/MO BORDER. HRRR MODEL
SUGGESTS THAT A SMALL CLUSTER OF STORMS SHOULD BE ONGOING IN
NORTHEAST/EAST NEBRASKA WHILE THE NMM/ARW SUGGEST THAT THE
CONVECTION OVER NEBRASKA WILL DISSIPATE AND REDEVLOP OVER FAR
SOUTHERN IA/MO. HOPWRF ALSO SHOWS EASTERN NEBRASKA CONVECTION
CONTINUING TO INTENSIFY WITH TIME THIS AFTERNOON MOVING ESE. THIS IS
SUPPORTED BY THE MEAN AND FORWARD PROPAGATING CORFIDI VECTORS...WITH
TRANSLATION ABOUT 30 TO 40 KTS. WITH THE WEAK BOUNDARY OVER THE
IOWA/MISSOURI BORDER BY 00Z...ANY CONVECTION THAT DEVELOPS TO OUR
WEST WILL RAPIDLY INTENSIFY INTO THE AXIS OF HIGH CAPE THIS
AFTERNOON. GIVEN THE VARIOUS SOLUTIONS...AM LEANING TOWARD
CONVECTION DEVELOPING IN NORTHEAST/EAST NEBRASKA AND STRENGTHENING
RAPIDLY THIS AFTERNOON AS IT INTERACTS WITH THE MOISTURE POOL IN AND
NEAR IOWA TO THE SOUTH. HAVE INCREASED POP ACROSS THIS AREA TO
REFLECT THAT SCENARIO. THE SOUTH IS OUTLOOKED FOR A SLIGHT
RISK...LOOKS VERY REASONABLE WITH THE POTENTIAL OF A STRENGTHENING
FORWARD PROPAGATING CONVECTIVE COMPLEX NEAR/JUST NORTH OF THE
BOUNDARY LATER TODAY THROUGH EITHER SOUTHERN IOWA OR NORTHERN
MISSOURI. THERE WILL BE A POTENTIAL FOR HIGHER IMPACT CONVECTIVE
WINDS IF THE SYSTEM GETS STRONG ENOUGH PRIOR TO MOVING SOUTH/EAST OF
THE AREA THIS EVENING. PRECIPITABLE WATER INCREASES TO OVER TWO
INCHES SOUTH OF INTERSTATE 80 THIS AFTERNOON WITH WARM CLOUD DEPTHS
OF 13 TO 14KFT TODAY AS WELL. IN ANY STRONGER STORMS THAT DEVELOP...
A QUICK 1 TO +2 INCHES IS VERY POSSIBLE DESPITE THE PROJECTED FAST
MOVEMENT OF THE STORMS. HIGHS WILL AGAIN BE WARM SOUTH IN THE UPPER
80S TO NEAR 90 WITH LOWER TO MID 80S ACROSS THE NORTH. WINDS WILL
NOT BE APPRECIABLE STRONG AND GENERALLY OUT OF THE NORTHEAST.
.LONG TERM /TONIGHT THROUGH FRIDAY/...
ISSUED AT 345 AM CDT SAT JUL 26 2014
NEARLY ALL OF THE CONCERNS IN THIS PERIOD WILL BE EARLY ON...THIS
EVENING. THE AIRMASS WILL BE THERMODYNAMICALLY PRIMED DURING PEAK
HEATING WITH THE GFS/NAM SUGGESTING MLCAPES 4K J/KG OR GREATER AND
LITTLE CINH. ONLY QUESTION WILL BE WHETHER A TRIGGER MECHANISM WILL
BE IN PLACE AND THAT SEEMS TO BE LESS AND LESS OF A CONCERN
JUDGING FROM CURRENT UPSTREAM CONDITIONS. RAP OBJECTIVE ANALYSIS
AND WATER VAPOR LOOP SHOW SEVERAL SHORT WAVES/PV ANOMALIES
TOPPING THE SWRN CONUS RIDGE AND EMBEDDED IN THE SEASONALLY FAST
PACIFIC NW TO NRN PLAINS UPPER FLOW. THIS KINEMATIC FORCING IS
CURRENTLY DRIVING SMALL WRN KS AND SD CONVECTIVE CLUSTERS IN
AREAS OF WEAK THERMODYNAMIC SUPPORT. THUS EXPECT REMNANTS OF THESE
FEATURES AND ASSOCIATED FORCING TO BE TRAVERSING SRN IA/NRN MO
DURING PEAK HEATING IN THE VICINITY OF CURRENT SURFACE
FRONT...NOTED ALONG SRN ONE/TWO TIERS OF IA COUNTIES PER 07Z
ANALYSIS. OPERATIONAL AND HI RES MODELS SUGGEST CONVERGENCE
ASSOCIATED WITH THIS BOUNDARY WILL BE INTO MO BY 00Z...BUT
EXISTING CONVECTION FROM EARLIER IN THE DAY MAY ALSO BE IN PLACE
JUST NORTH OF THE BOUNDARY AS WELL AS MENTIONED IN SHORT TERM
DISCUSSION. ALTHOUGH THE SHALLOW SHEAR IS WEAK...THE DEEP SHEAR
SHOULD BE IN THE 50KT RANGE SUGGESTING ANYTHING THAT DOES NEWLY DEVELOP
COULD BE SUPERCELLULAR INITIALLY. ALTHOUGH THE 0-1KM KINEMATICS
ARE WEAK...THE DEGREE OF DEEP AND 0-3KM INSTABILITY MAY KEEP A FEW
THERMODYNAMICALLY DOMINATE TORNADOES IN THE PICTURE AS WELL...IN
ADDITION TO THE WIND AND HAIL THREAT AS SYSTEM EVOLVES AND LIKELY
BECOMES MORE LINEAR. WHATEVER DOES OCCUR WILL EITHER MOVE OUT OF
OUR FORECAST AREA QUICKLY...OR STAY INTO NRN MO SO OUR WINDOW WILL
BE BRIEF WITH DRY CONDITIONS OVERNIGHT.
COOLER TEMPERATURES WILL THEN BE THE PRIMARY WEATHER STORY INTO
EARLY NEXT WEEK. THERE IS LITTLE IN THE WAY OF FORCING OR WARM
ADVECTION RIGHT ON THROUGH THE EXTENDED...AND EITHER UNIFORM NW
SURFACE FLOW OR LIGHT AND VARIABLE WINDS SHOULD LEAD TO MINIMAL LOW
LEVEL CONVERGENCE. STEEP LAPSE RATES NEAR THE CORE OF THE CURRENT
SASKATCHEWAN AND EVENTUALLY WRN GREAT LAKES UPPER LOW MAY DEVELOP
SOME SHOWERS NE DURING PEAK HEATING SUN...BUT OTHERWISE HAVE EITHER
A DRY FORECAST OR ONLY SLIGHTS FOR THE REMAINDER OF THE FORECAST.
TEMPS STILL LOOK BELOW NORMAL WITH HIGHS OFTEN IN THE 70S AND NO
BETTER THAN THE LOW 80S. LOWS SHOULD OFTEN BE IN THE 50S OR LOWER
60S. ALTHOUGH UPPER LEVEL WINDS WILL EVENTUALLY DIMINISH WITH SOME
HEIGHT RISES...THE OVERALL PATTERN /MORE POSITIVE PNA/ WILL
CHANGE LITTLE INTO NEXT WEEKEND WITH WRN CONUS RIDGE/ERN TROUGH.
&&
.AVIATION...26/18Z
ISSUED AT 1235 PM CDT SAT JUL 26 2014
NOTABLE CHANGES SINCE 12Z TAF. IN THE SHORT TERM...TSRA OVER NW
IOWA. THESE STORMS WILL MOVE EAST AND IMPACT KFOD AND KMCW FOR
NEXT FEW HOURS. FOR LATER THIS AFTERNOON AND EVENING...BOUNDARY
LOCATED IN NORTHERN MO WILL MOVE NORTHWARD INTO SOUTHERN IA. THIS
BOUNDARY WILL BE FOCUS FOR SEVERE WX THREAT...WITH DAMAGING WINDS
PRIMARY THREAT...LARGE HAIL SECONDARY THREAT. DROPPED TS FROM
KDSM TAFS AS IT APPEARS STORMS SHOULD STAY SOUTH OF METRO AREA.
LEFT TSRA IN KOTM TAFS...BUT STORMS MAY STAY SOUTH OF KOTM AS
WELL. WILL...OF COURSE...BE MONITORING AND UPDATING THROUGHOUT
DAY. SKC AND LIGHT WINDS BEHIND THIS SYSTEM FOR OVERNIGHT.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...REV
LONG TERM...SMALL
AVIATION...KOTENBERG
AREA FORECAST DISCUSSION
NWS GOODLAND KS
233 PM MDT SAT JUL 26 2014
.SHORT TERM...(THIS AFTERNOON THROUGH SUNDAY)
ISSUED AT 131 PM MDT SAT JUL 26 2014
LATEST WV IMAGE AND RAP UPPER LEVEL ANALYSIS SHOW BROAD RIDGE STILL
IN PLACE FROM THE DESERT SOUTHWEST ACROSS THE SOUTHERN PLAINS AND
INTO THE SOUTHERN MISSISSIPPI VALLEY. A PLUME OF MONSOONAL MOISTURE
CONTINUES TO ROUND THE WESTERN AND NORTHERN PERIPHERY OF THIS RIDGE
INTO THE CENTRAL ROCKIES AND HIGH PLAINS. A CLOSED LOW IS CENTERED
OVER SOUTHERN MANITOBA CANADA WITH A SHORTWAVE TROUGH OUT AHEAD OF
THIS ENTERING THE NORTHERN MISSISSIPPI VALLEY. AT THE SURFACE LOW
PRESSURE IS IN PLACE OVER OUR CWA WITH SEVERAL WEAK CONVERGENT AREAS
ACROSS OUR SOUTH...AND A COLD FRONT ENTERING NORTHWEST KANSAS FROM
COLORADO AND SOUTHWEST NEBRASKA.
RAP ANALYSIS INDICATES MODERATE SB/MIXED LAYER CAPE VALUES AHEAD OF
MEAN SURFACE TROUGH AXIS ACROSS MOST OF OUR CWA. SHEER IS NOT
PARTICULARLY IMPRESSIVE...HOWEVER WITH SOUNDINGS SHOWING INVERTED V
TYPE SOUNDINGS AND DCAPE 1000 J/KG OR HIGHER MICROBURST POTENTIAL IS
THERE FOR ANY THUNDERSTORM ACTIVITY. GUIDANCE CONTINUES TO FAVOR THE
SOUTHERN PART OF OUR CWA FOR THUNDERSTORM COVERAGE...MAINLY ALONG
AND AHEAD OF COLD FRONT. WEAK FORCING ROTATING FROM THE NORTH
LATER THIS EVENING MAY ALSO SUPPORT ADDITIONAL POST FRONTAL
THUNDERSTORM DEVELOPMENT. POP ADJUSTMENTS WERE MADE TO REFLECT
THESE TRENDS THROUGH TONIGHT. SUBSIDENT AIR MASS APPEARS TO BE IN
PLACE OVER MOST OF THE CWA SUNDAY...THOUGH BY SUNDAY AFTERNOON
UPSLOPE COMBINED WITH OVERRUNNING ALONG STALLED FRONTAL ZONE IN
COLORADO MAY ALLOW FOR SHOWER/THUNDERSTORM DEVELOPMENT INTO THE SW
PART OF THE CWA IN THE AFTERNOON.
TEMPERATURES SATURDAY SHOULD BE COOLER...HOWEVER THERE IS QUITE A
BIT OF SPREAD DUE TO NAM/SREF LINGERING PRECIP MOST OF THE DAY
ACROSS MUCH OF THE CWA. I AM NOT FAVORING THIS SOLUTION AS BETTER
SUPPORT FOR SHOWER/THUNDERSTORM (AND ANY LOW CLOUD COVER) WOULD BE
FURTHER WEST AND SOUTHWEST. IF THE NAM/SREF WERE CORRECT THEN HIGHS
IN THE LOW 80S FOR WESTERN PARTS OF THE CWA. BASED ON THE FAVORED
WARMER SOLUTION WE SHOULD SEE HIGHS WARM TO NEAR NORMAL VALUES IN
THE UPPER 80S FOR A LOT OF THE CWA SUNDAY.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 232 PM MDT SAT JUL 26 2014
SUNDAY NIGHT THROUGH TUESDAY...FORECAST CONCERNS FOR THE PERIOD
INCLUDE COOLING TEMPERATURES AND PRECIPITATION CHANCES...MAINLY IN
THE SOUTHWESTERN PORTION OF THE CWA. NEAR TERM MODELS IN GENERAL
AGREEMENT WITH LARGE SCALE PATTERN AND ALL SUGGEST A MUCH COOLER
START TO THE WEEK THAN THE PAST WEEK.
CWA WILL FIND ITSELF ON THE NORTHEAST FRINGE OF PERSISTENT H5 RIDGE
OVER THE ROCKIES. DESPITE THE RIDGE POSITION...PERIODS OF ASCENT
ACROSS WILL PERIODICALLY DEVELOP AS NUMEROUS SMALL SCALE
DISTURBANCES AND PERSISTENT WEAK WAA REMAIN ACROSS WESTERN HALF OF
THE CWA. ALTHOUGH FORCING IS WEAK...DO NOT SEE ANY REASON WHY MID
LEVELS WILL DRY OUT DURING THE PERIOD AND WITH ELEVATED CAPE PRESENT
THROUGHOUT THINK WE WILL SEE SEVERAL PERIODS OF SHOWERS AND WEAK
THUNDERSTORMS. TRIED TO ADD SOME DIURNAL COMPONENT TO WX TIMING AS
THINK BEST CHANCES WILL BE GENERALLY IN THE OVERNIGHT HOURS AS
MODEST LOW LEVEL JET DEVELOPS TO AID IN MOISTURE ADVECTION/FORCED
ASCENT. GIVEN THE POSITION OF GREATER INSTABILITY AND OVERALL
PATTERN AM NOT EXPECTING LARGE PRECIPITATION AMOUNTS FOR THE PERIOD.
COLD FRONTAL PASSAGE COMBINED WITH PERSISTENT CLOUD COVER WILL
LIKELY LEAD TO MUCH COOLER TEMPERATURES FOR THE PERIOD...ABOUT 10 TO
20 DEGREES COOLER THAN PAST FEW DAYS.
IN THE EXTENDED(TUESDAY NIGHT-SATURDAY)...SIMILAR PATTERN TO
CONTINUE ACROSS TRI STATE AREA THROUGH THE END OF THE WEEK AS H5
RIDGE GRADUALLY AMPLIFIES IN RESPONSE TO TROUGHING DEVELOPING ACROSS
THE SOUTHEAST AND MIDWEST. GEFS AND OPERATIONAL MODELS CONTINUE TO
SUPPORT A HIGH PRECIP POTENTIAL ON TUESDAY NIGHT AND WEDNESDAY AS
MORE SIGNIFICANT SHORT WAVE TROUGH MOVES ACROSS THE AREA. MOISTURE
AND INSTABILITY SHOULD ALREADY BE IN PLACE WITH MAIN CONCERN BEING
HOW FAR NORTH/EAST PRECIP SHIELD WILL GO. STILL THINK BEST CHANCE
FOR RAIN WILL BE ACROSS SOUTHWESTERN CWA SO MADE ONLY MINOR CHANGES
HERE. OTHERWISE...COOLER TEMPERATURES AS A FEW CHANCES FOR LIGHT
PRECIPITATION ARE ANTICIPATED FOR THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1124 AM MDT SAT JUL 26 2014
VFR CONDITIONS SHOULD PREVAIL THROUGH THE TAF PERIOD AT KGLD AND
KMCK. MAIN AVIATION CONCERN WILL BE THUNDERSTORM ACTIVITY MAINLY
EXPECTED TO IMPACT LOCATIONS SOUTH OF INTERSTATE 70 AND KGLD. KEPT
VCTS MENTION IN KGLD TAF FOR THIS EVENING...AND LEFT MENTION OUT
OF KMCK. ADDITIONAL THUNDERSTORM ACTIVITY REDEVELOP OR
LINGER LATER TONIGHT...HOWEVER I FELT MOST CONFIDENT WITH THE
EVENING PERIOD AT THIS POINT. WINDS FROM THE NORTHWEST 10-15KT
WILL EVENTUALLY SHIFT TO THE NORTHEAST AS A SURFACE LOW MOVES
SOUTH...THEN A COLD FRONT WILL MOVE OVER BOTH TERMINALS THIS
EVENING AND THERE COULD BE A BRIEF PERIOD OF GUSTY WINDS FROM THE
NORTHEAST. AFTER 06Z NORTHEAST WINDS AROUND 10KT SHOULD PREVAIL
WITH FRONT SOUTH OF BOTH TERMINALS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR KSZ004-016.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JRM
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
132 PM MDT SAT JUL 26 2014
.SHORT TERM...(THIS AFTERNOON THROUGH SUNDAY)
ISSUED AT 131 PM MDT SAT JUL 26 2014
LATEST WV IMAGE AND RAP UPPER LEVEL ANALYSIS SHOW BROAD RIDGE STILL
IN PLACE FROM THE DESERT SOUTHWEST ACROSS THE SOUTHERN PLAINS AND
INTO THE SOUTHERN MISSISSIPPI VALLEY. A PLUME OF MONSOONAL MOISTURE
CONTINUES TO ROUND THE WESTERN AND NORTHERN PERIPHERY OF THIS RIDGE
INTO THE CENTRAL ROCKIES AND HIGH PLAINS. A CLOSED LOW IS CENTERED
OVER SOUTHERN MANITOBA CANADA WITH A SHORTWAVE TROUGH OUT AHEAD OF
THIS ENTERING THE NORTHERN MISSISSIPPI VALLEY. AT THE SURFACE LOW
PRESSURE IS IN PLACE OVER OUR CWA WITH SEVERAL WEAK CONVERGENT AREAS
ACROSS OUR SOUTH...AND A COLD FRONT ENTERING NORTHWEST KANSAS FROM
COLORADO AND SOUTHWEST NEBRASKA.
RAP ANALYSIS INDICATES MODERATE SB/MIXED LAYER CAPE VALUES AHEAD OF
MEAN SURFACE TROUGH AXIS ACROSS MOST OF OUR CWA. SHEER IS NOT
PARTICULARLY IMPRESSIVE...HOWEVER WITH SOUNDINGS SHOWING INVERTED V
TYPE SOUNDINGS AND DCAPE 1000 J/KG OR HIGHER MICROBURST POTENTIAL IS
THERE FOR ANY THUNDERSTORM ACTIVITY. GUIDANCE CONTINUES TO FAVOR THE
SOUTHERN PART OF OUR CWA FOR THUNDERSTORM COVERAGE...MAINLY ALONG
AND AHEAD OF COLD FRONT. WEAK FORCING ROTATING FROM THE NORTH
LATER THIS EVENING MAY ALSO SUPPORT ADDITIONAL POST FRONTAL
THUNDERSTORM DEVELOPMENT. POP ADJUSTMENTS WERE MADE TO REFLECT
THESE TRENDS THROUGH TONIGHT. SUBSIDENT AIR MASS APPEARS TO BE IN
PLACE OVER MOST OF THE CWA SUNDAY...THOUGH BY SUNDAY AFTERNOON
UPSLOPE COMBINED WITH OVERRUNNING ALONG STALLED FRONTAL ZONE IN
COLORADO MAY ALLOW FOR SHOWER/THUNDERSTORM DEVELOPMENT INTO THE SW
PART OF THE CWA IN THE AFTERNOON.
TEMPERATURES SATURDAY SHOULD BE COOLER...HOWEVER THERE IS QUITE A
BIT OF SPREAD DUE TO NAM/SREF LINGERING PRECIP MOST OF THE DAY
ACROSS MUCH OF THE CWA. I AM NOT FAVORING THIS SOLUTION AS BETTER
SUPPORT FOR SHOWER/THUNDERSTORM (AND ANY LOW CLOUD COVER) WOULD BE
FURTHER WEST AND SOUTHWEST. IF THE NAM/SREF WERE CORRECT THEN HIGHS
IN THE LOW 80S FOR WESTERN PARTS OF THE CWA. BASED ON THE FAVORED
WARMER SOLUTION WE SHOULD SEE HIGHS WARM TO NEAR NORMAL VALUES IN
THE UPPER 80S FOR A LOT OF THE CWA SUNDAY.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 221 AM MDT SAT JUL 26 2014
HIGH PRESSURE AT 500 AND 700 MB WILL BE PRESENT OVER THE TRI STATE
AREA IN THE LONG TERM PERIOD WITH MAIN JET FLOW WELL TO THE NORTH OF
THE REGION. DESPITE THE LACK OF FORCING THAT WILL BE PRESENT
ALOFT...PLENTY OF MOISTURE WILL BE PRESENT WITH PRECIPITABLE WATER
AMOUNTS FROM THE GFS BETWEEN 1.25 AND 1.6 INCHES FOR THE DURATION OF
THE LONG TERM PERIOD. THE ECMWF ALSO HAS BETWEEN 1.25 AND 1.5 INCHES
OF PRECIPITABLE WATER FOR TUESDAY AND WEDNESDAY...AND THEN BRINGS IN
MORE DRY AIR ALOFT FOR LATER IN THE WEEK. THEREFORE...THE POTENTIAL
FOR SOME HEAVY RAINFALL WILL EXIST AREA WIDE.
A LOW PRESSURE SYSTEM DEVELOPING IN THE SOUTHERN PLAINS IN
COMBINATION WITH SOME SURFACE CONFLUENCE IN EASTERN COLORADO WILL
BRING CHANCES FOR THUNDERSTORMS TUESDAY THROUGH THURSDAY. THE
POTENTIAL FOR DRY AIR MOVING IN ALOFT WILL DECREASE CHANCES FOR
THUNDERSTORMS ON FRIDAY...HOWEVER SURFACE THETA E VALUES BETWEEN 330
AND 350 K ARE STILL PLENTY TO SUPPORT SOME STORMS THAT MAY DEVELOP.
INSTABILITY IS NOT TOO IMPRESSIVE WITH CAPE VALUES BELOW 1000 J/KG
FOR BOTH THE GFS AND ECMWF...BUT IS STILL SUFFICIENT ENOUGH TO
SUPPORT SOME CONVECTIVE DEVELOPMENT.
NORTHWEST FLOW ALOFT WILL KEEP CONDITIONS AT THE SURFACE A BIT
COOLER THAN AVERAGE DURING THIS PERIOD...WITH HIGH TEMPERATURES IN
THE LOW TO MID 80S ACROSS THE AREA. LOW TEMPERATURES SHOULD BE RIGHT
ABOUT NORMAL IN THE LOWER 60S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1124 AM MDT SAT JUL 26 2014
VFR CONDITIONS SHOULD PREVAIL THROUGH THE TAF PERIOD AT KGLD AND
KMCK. MAIN AVIATION CONCERN WILL BE THUNDERSTORM ACTIVITY MAINLY
EXPECTED TO IMPACT LOCATIONS SOUTH OF INTERSTATE 70 AND KGLD. KEPT
VCTS MENTION IN KGLD TAF FOR THIS EVENING...AND LEFT MENTION OUT
OF KMCK. ADDITIONAL THUNDERSTORM ACTIVITY REDEVELOP OR
LINGER LATER TONIGHT...HOWEVER I FELT MOST CONFIDENT WITH THE
EVENING PERIOD AT THIS POINT. WINDS FROM THE NORTHWEST 10-15KT
WILL EVENTUALLY SHIFT TO THE NORTHEAST AS A SURFACE LOW MOVES
SOUTH...THEN A COLD FRONT WILL MOVE OVER BOTH TERMINALS THIS
EVENING AND THERE COULD BE A BRIEF PERIOD OF GUSTY WINDS FROM THE
NORTHEAST. AFTER 06Z NORTHEAST WINDS AROUND 10KT SHOULD PREVAIL
WITH FRONT SOUTH OF BOTH TERMINALS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR KSZ004-016.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...MK
AVIATION...DR
AREA FORECAST DISCUSSION
NWS PADUCAH KY
256 PM CDT Sat Jul 26 2014
.SHORT TERM...(Tonight through Monday night)
Issued at 255 PM CDT SAT JUL 26 2014
All evidence points to the cap (see ILX and DVN 18Z RAOBS)
holding strong across the area late this afternoon and tonight.
The lone exception may be along the I-64 corridor, where a
complex of thunderstorms may push rapidly eastward generally in
the 01Z-05Z timeframe this evening.
The HRRR is still unable to generate a larger-scale bowing system,
as seen on some of the shorter range models this morning. The 12Z NAM
and GFS soundings show some weakness at times in the mid-level
flow across our north, so the overall organization of any storms
that develop may not be as significant as previously thought.
Individual storm cells may have enough 0-3KM SRH to support
rotating updrafts and would not be surprised to see some
supercells initially, where storms can develop this evening.
Damaging winds and large hail will be possible, and a few
tornadoes can not be ruled out with any individual cells this
evening. However, figure the cap will suppress any activity that
tries to dip south of I-64, or possibly even into our northern-
most counties.
The mid-upper 70 dewpoints have descended upon the region as expected,
and heat indices have reached triple digits over much of the area.
Already issued a Special Weather Statement for the heat. It should
subside by 7 PM, and would be surprised to see values above 105,
so will not be issuing a Heat Advisory at this time.
Overnight, the models struggle to generate much, if any,
convection over our region, so will keep PoPs at 30% or less.
The cold front will move through the region Sunday, and the low
to mid 70 dewpoints and temperatures well into the 90s are
expected ahead of it over the southeast 2/3 of the area in the
afternoon. This could lead to heat indices near today`s levels,
and a righteous airmass for strong to severe thunderstorms to feed
on. Winds ahead of the front will be nearly due west, and quite
strong, pushing Lake Wind Advisory levels, especially east of the
Mississippi River. The veered winds result in only weak
convergence along the boundary, so thunderstorm coverage is
expected to be widely scattered to scattered, with better coverage
later in the day along the Tennessee border. Certainly cannot rule
out a few severe storms mainly over west Kentucky and southwest
Indiana. The consensus of guidance is that most if not all of
the convective activity will shift south of the area by early
Sunday evening.
Will have a dry forecast for the entire area overnight Sunday
through Monday Night. A deep trough over the Great Lakes and
northeast will keep the area in strong northwest flow aloft
through the period. North winds will bring much cooler and drier
air into the region through the period, as well.
.LONG TERM...(Tuesday through Saturday)
Issued at 255 PM CDT SAT JUL 26 2014
Above medium confidence in the extended.
High pressure aloft will be firmly in place over west with a
persistent upper level trough over the east. This will place in a
much drier northerly flow in the fronts wake. This will also result
in unseasonable low RH reading for most of the upcoming week. By the
end of the week the upper level trough deepens and even suggest a
cut off upper low forming the lower Tennessee Valley Friday into the
weekend. This will allow for at least daytime storm chances mainly
in the afternoon with max heating...but could not rule out some
activity into the evening hours.
Temperatures will much cooler than normal through the extended with
lower to middle 80s for the region.
&&
.AVIATION...
Issued at 1235 PM CDT SAT JUL 26 2014
The main concern to aviation for this forecast cycle is the
potential for a complex of severe storms with damaging winds
pushing rapidly east southeast through KEVV and possibly KOWB this
evening and possibly overnight. At this time, forecast confidence
is quite low in this evolution, and there is a real possibility
that the storms will stay north and east of the terminals. Will
not insert TS in the TAFs at this time, as there should be ample
time to add it into the forecast when it becomes more obvious its
going to happen.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...DRS
LONG TERM...KH
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1236 PM CDT Sat Jul 26 2014
.UPDATE...
Issued at 1235 PM CDT SAT JUL 26 2014
The AVIATION section has been updated for the 18Z TAF issuance.
UPDATE Issued at 1205 PM CDT SAT JUL 26 2014
A relatively shallow boundary layer will allow temperatures warm
into the lower 90s over most of the area as expected this
afternoon. However, it will also trap the low-level moisture, and
allow mid 70 dewpoints to overspread the region through the
afternoon. This will create heat indices in the 100 to 105 range
over most of the region. Will likely issue an SPS for the heat in
the next hour.
As for severe weather, SPC has just pushed the southern edge of
their moderate risk northward, right along our northern border in
southern Illinois. There is a whole lot of uncertainty in the
convective evolution to support a moderate risk into our area.
The latest HRRR runs have been developing convection near the STL
metro area around 00Z, presumably near the MCV that is currently
over northwest Missouri. The HRRR then pushes the convection east
southeast along our northern border areas in the 02Z-05Z timeframe.
It has not shown any signs of a larger-scale bowing MCS/derecho,
like the 00Z WRF runs were advertising.
If storms do push into our area this evening, damaging winds will
be the primary concern, with large hail and tornadoes lesser
concerns. Of course, there is a real possibility that this evening
activity could stay completely north of our forecast area. There
could be some convection firing over the Evansville Tri State into
the overnight hours, if an outflow boundary pushes into that area.
Damaging wind would be the primary concern overnight.
&&
.SHORT TERM...(Today through Sunday night)
Issued at 249 AM CDT SAT JUL 26 2014
Biggest forecast challenge this period is on how to deal with
MCS development this afternoon and possibly again early tonight.
Much of the meso-convective models this morning point to rapid
destabilization this afternoon as surface temperatures soar into
the 90s and dew points climb into the upper 60s to near 70. Thing
is, most of the region should remain under thermal capping until
later in the day. MCS development is likely to occur over se IA and
west central MO this afternoon, then propagate ese toward the I-70
and I-64 corridors late in the day as the capping weakens. There is
some question as to whether this initial convection will brush by
just to our north or actually clip the I-64 corridor of IL/sw IN.
Given the extreme instability expected and decent wind fields
aloft, what convection does form later today has a very good
chance of being severe at times, with damaging wind gusts, large
hail and even isolated tornadoes possible. Even if this initial
convection/MCS misses our forecast area, additional thunderstorm
development will be possible along its outflow boundary early this
evening and into the night.
Cold front enters the scene late tonight into Sun AM, and will
likely be located somewhere near the OH River by noon. Depending on
the degree of heating that can occur along ahead of this front,
more strong thunderstorm development could occur in areas along
and south of the OH River Sunday afternoon. Should finally clear
out Sunday night behind the sfc front as much cooler and drier air
flows back into the region.
.LONG TERM...(Monday through Friday)
Issued at 249 AM CDT SAT JUL 26 2014
A very tranquil week is coming up for the region next week. By 12Z
Monday, the upper level wave and associated sfc front will be in the
eastern Great Lakes region and will continue to move off the eastern
seaboard by 12Z Tuesday. During the week, our region will be under
the influence of a large trough across the eastern half of the
country, with amplified ridging taking place out west. Models bring
a weak lobe of energy southward across the area on Monday, but it
should only result in some passing clouds, as moisture is limited.
The 00Z NAM/GFS hints at a possible shower to two in parts of
southwest IN where moisture might be a little better, but will leave
dry for now. However, the bigger story to start out the week, will
be the below normal temperatures.
High pressure from central Canada will migrate south/southeastward
toward us early next week and bring a much cooler/drier airmass into our
region. While we will see much cooler temperatures on Monday as
compared to the projected weekend heat, the coolest air will likely
take until about Tuesday to arrive. This means that we should
experience another few degree drop in temperatures then, with some
places likely only reaching the upper 70s for highs. Guidance
numbers have been rather consistent for the past few days so no real
changes to temperatures needed right now.
With high pressure influencing the weather through at least
Thursday, we should expect a mainly rain free forecast with
temperatures moderating back into the low to mid 80s by mid to late
week. Northwest flow can be tricky with regards to figuring out if
there could be any decent chances for rain, but moisture will
definitely be limited to just the lower levels. By Thursday night
and into Friday though, the sfc high breaks down and deeper moisture
advects into the area. This increase in moisture, along with a lobe
of energy pivoting down in the northwest flow aloft, could mean some
chances convection by the end of the week.
&&
.AVIATION...
Issued at 1235 PM CDT SAT JUL 26 2014
The main concern to aviation for this forecast cycle is the
potential for a complex of severe storms with damaging winds
pushing rapidly east southeast through KEVV and possibly KOWB this
evening and possibly overnight. At this time, forecast confidence
is quite low in this evolution, and there is a real possibility
that the storms will stay north and east of the terminals. Will
not insert TS in the TAFs at this time, as there should be ample
time to add it into the forecast when it becomes more obvious its
going to happen.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
SHORT TERM...GM
LONG TERM...CW
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1205 PM CDT Sat Jul 26 2014
.UPDATE...
Issued at 1205 PM CDT SAT JUL 26 2014
A relatively shallow boundary layer will allow temperatures warm
into the lower 90s over most of the area as expected this
afternoon. However, it will also trap the low-level moisture, and
allow mid 70 dewpoints to overspread the region through the
afternoon. This will create heat indices in the 100 to 105 range
over most of the region. Will likely issue an SPS for the heat in
the next hour.
As for severe weather, SPC has just pushed the southern edge of
their moderate risk northward, right along our northern border in
southern Illinois. There is a whole lot of uncertainty in the
convective evolution to support a moderate risk into our area.
The latest HRRR runs have been developing convection near the STL
metro area around 00Z, presumably near the MCV that is currently
over northwest Missouri. The HRRR then pushes the convection east
southeast along our northern border areas in the 02Z-05Z timeframe.
It has not shown any signs of a larger-scale bowing MCS/derecho,
like the 00Z WRF runs were advertising.
If storms do push into our area this evening, damaging winds will
be the primary concern, with large hail and tornadoes lesser
concerns. Of course, there is a real possibility that this evening
activity could stay completely north of our forecast area. There
could be some convection firing over the Evansville Tri State into
the overnight hours, if an outflow boundary pushes into that area.
Damaging wind would be the primary concern overnight.
UPDATE Issued at 733 AM CDT SAT JUL 26 2014
For aviation section only.
&&
.SHORT TERM...(Today through Sunday night)
Issued at 249 AM CDT SAT JUL 26 2014
Biggest forecast challenge this period is on how to deal with
MCS development this afternoon and possibly again early tonight.
Much of the meso-convective models this morning point to rapid
destabilization this afternoon as surface temperatures soar into
the 90s and dew points climb into the upper 60s to near 70. Thing
is, most of the region should remain under thermal capping until
later in the day. MCS development is likely to occur over se IA and
west central MO this afternoon, then propagate ese toward the I-70
and I-64 corridors late in the day as the capping weakens. There is
some question as to whether this initial convection will brush by
just to our north or actually clip the I-64 corridor of IL/sw IN.
Given the extreme instability expected and decent wind fields
aloft, what convection does form later today has a very good
chance of being severe at times, with damaging wind gusts, large
hail and even isolated tornadoes possible. Even if this initial
convection/MCS misses our forecast area, additional thunderstorm
development will be possible along its outflow boundary early this
evening and into the night.
Cold front enters the scene late tonight into Sun AM, and will
likely be located somewhere near the OH River by noon. Depending on
the degree of heating that can occur along ahead of this front,
more strong thunderstorm development could occur in areas along
and south of the OH River Sunday afternoon. Should finally clear
out Sunday night behind the sfc front as much cooler and drier air
flows back into the region.
.LONG TERM...(Monday through Friday)
Issued at 249 AM CDT SAT JUL 26 2014
A very tranquil week is coming up for the region next week. By 12Z
Monday, the upper level wave and associated sfc front will be in the
eastern Great Lakes region and will continue to move off the eastern
seaboard by 12Z Tuesday. During the week, our region will be under
the influence of a large trough across the eastern half of the
country, with amplified ridging taking place out west. Models bring
a weak lobe of energy southward across the area on Monday, but it
should only result in some passing clouds, as moisture is limited.
The 00Z NAM/GFS hints at a possible shower to two in parts of
southwest IN where moisture might be a little better, but will leave
dry for now. However, the bigger story to start out the week, will
be the below normal temperatures.
High pressure from central Canada will migrate south/southeastward
toward us early next week and bring a much cooler/drier airmass into our
region. While we will see much cooler temperatures on Monday as
compared to the projected weekend heat, the coolest air will likely
take until about Tuesday to arrive. This means that we should
experience another few degree drop in temperatures then, with some
places likely only reaching the upper 70s for highs. Guidance
numbers have been rather consistent for the past few days so no real
changes to temperatures needed right now.
With high pressure influencing the weather through at least
Thursday, we should expect a mainly rain free forecast with
temperatures moderating back into the low to mid 80s by mid to late
week. Northwest flow can be tricky with regards to figuring out if
there could be any decent chances for rain, but moisture will
definitely be limited to just the lower levels. By Thursday night
and into Friday though, the sfc high breaks down and deeper moisture
advects into the area. This increase in moisture, along with a lobe
of energy pivoting down in the northwest flow aloft, could mean some
chances convection by the end of the week.
&&
.AVIATION...
Issued at 733 AM CDT SAT JUL 25 2014
Will be in warm sector during this TAF period. A complex of
thunderstorms is expected to develop over IA/IL and move east
southeast toward the I 64 region aft 21z. Could brush KEVV/KOWB
late in the day or during the evening, but confidence not high
enough at this time to mention explicitly in TAFS.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
SHORT TERM...GM
LONG TERM...CW
AVIATION...GM
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1230 PM CDT SAT JUL 26 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 318 AM CDT SAT JUL 26 2014
EARLY MORNING WATER VAPOR IMAGERY WITH GFS26.00 500MB HEIGHTS AND
WINDS SHOWED A COMPACT UPPER LEVEL LOW IN SOUTHERN MANITOBA...AND
AN UPPER LEVEL RIDGE CENTERED OVER NORTHERN TEXAS. THIS LED TO QUICK
ZONAL FLOW OVER THE NORTHERN THIRD OF THE CONUS...WITH A WEAK
SHORTWAVE LOCATED OVER CENTRAL SOUTH DAKOTA. THIS SHORTWAVE WAS ABLE
TO FIRE OFF A FEW THUNDERSTORMS OVERNIGHT. THE LEADING EDGE OF THESE
STORMS WERE FALLING APART...AND THE LATEST RUNS OF THE HIRES
MODELS...INCLUDING THE HOPWRF AND HRRR SHOW THE DEVELOPING
CONVECTION DIVING SOUTHEAST OVER SOUTHWEST MINNESOTA AND NORTHERN
IOWA. THEREFORE HAVE INTRODUCED A SLIGHT CHANCE OF POPS ACROSS THE
FAR SOUTHWESTERN CWA.
LATER TODAY INSTABILITY WILL BUILD ALONG A WEAK SURFACE
TROUGH...WITH AN UPPER LEVEL WAVE DIVING DOWN FROM CANADA. THIS WILL
SUPPORT A FEW LATE AFTERNOON SHOWERS AND THUNDERSTORMS MAINLY ACROSS
NORTHERN MN AND WI. FORECAST SOUNDINGS SHOW CIN HOLDING OFF
CONVECTION EARLY IN THE AFTERNOON...WITH DEEP MIXING BY LATE
EVENING. INCREASED THE WINDS ACROSS WESTERN MN TO REFLECT THIS
BOUNDARY LAYER MIXING. CONTINUED PRECIP CHANCES ACROSS THE NORTHEAST
OVERNIGHT SATURDAY WITH COOLER DRIER AIR MOVING IN FROM THE
NORTHWEST.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 318 AM CDT SAT JUL 26 2014
THE UPPER LOW WILL ROTATE SOUTHEASTWARD ACROSS WESTERN WISCONSIN
SUNDAY. SCATTERED TO NUMEROUS SHOWER COVERAGE EXPECTED ACROSS ERN
MN AND WRN WI...WITH ISOLATED LIGHT SHOWERS OR SPRINKLES EXPECTED
FURTHER SOUTHWEST ACROSS WRN/SRN MN. REMOVED THE THUNDER MENTION
DUE TO POOR LAPSE RATES AND LITTLE OR NO INSTABILITY. THIS EVENT
WILL BE SIMILAR TO THE ONE ABOUT 2 WEEKS AGO...EXCEPT THAT THIS
ONE IS A BIT WEAKER AND AREAL COVERAGE OF PRECIP IS NOT EXPECTED
TO BE AS IMPRESSIVE.
CLEARING SKIES WILL FOLLOW SUNDAY NIGHT WHICH WILL MARK THE
BEGINNING OF A LONG STRETCH OF MOSTLY CLEAR SKIES AND SEASONAL OR
SLIGHTLY BELOW NORMAL TEMPERATURES. NOT MUCH TO DISCUSS BEYOND
SUNDAY...EACH DAY WILL MORE OR LESS BE A CARBON COPY OF THE LAST.
THE TROUGH WILL REMAIN PARKED OVER THE GREAT LAKES WITH RIDGING
ACROSS THE ROCKIES AND THE WESTERN ATLANTIC FOR THE NEXT WEEK OR
TWO. REMOVED POPS FOR LATE NEXT WEEK DUE TO VERY WEAK FORCING AND
LITTLE OR NO INSTABILITY. THINKING THE WIDESPREAD QPF OVER WI ON
THE GFS AND ECMWF IS MUCH OVERDONE AND IS LIKELY A RESULT OF AN
OVERESTIMATION OF EVAPOTRANSPIRATION...AND SUPERADIABATIC LAPSE
RATES AT THE SURFACE DUE TO WINDS LESS THAN 3 KT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1212 PM CDT SAT JUL 26 2014
SFC FRONT MOVING EAST THIS AFTERNOON WITH CHANCE OF THUNDER
ASSOCIATED. BELIEVE WILL BE WIDELY SCT ALONG THE BOUNDARY. MAY
BECOME A BIT MORE ORGANIZED AS IT MOVES INTO WC WISCONSIN INTO TE
OVERNIGHT. EXPECT VFR CONDITIONS WITH CHC MVFR WITH THUNDER. THEN
LOWER MVFR CIGS WILL DEVELOP LATE TONIGHT IN THE NORTHWEST AREA
AND SPREAD SOUTHEAST THROUGH 12-14Z SUNDAY. SHRA WILL BE POSSIBLE
AS THE UPPER LOW DROPS SOUTHEAST WITH COLD POOL. WINDS EXPECTED TO
BECOME MORE S-SW AHEAD OF FRONT AND THEN W-NW AND INCREASE/BECOME
GUSTY INTO SUNDAY.
KMSP...
VFR WITH SMALL CHANCE MVFR/TSRA 00Z-03Z. THEN MVFR CIGS ARE EXPECTED
TO DROP SOUTHEAST LATE TONIGHT AND INTO SUNDAY AS UPPER LOW DROPS
MOVES THROUGH. SHRA THREAT ALSO DEVELOPS DURING THE MORNING. S-SW
WINDS DEVELOPING AHEAD OF SFC FRONT. THAT MOVES THROUGH THE
EVENING WITH W-NW WINDS DEVELOPING...INCREASING AND GUSTY DURING
THE DAY.
/OUTLOOK FOR KMSP/
MON...VFR. WINDS N AT 5KTS.
TUE...VFR. WINDS NAT 10KTS.
WED...VFR. WINDS N AT 5KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JRB
LONG TERM...BORGHOFF
AVIATION...DWE
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
340 PM CDT Sat Jul 26 2014
.SHORT TERM: (Through Late Tonight)
Issued at 324 PM CDT Sat Jul 26 2014
Primary concern continues to be convective trends for this evening.
Current trends are pointing more and more toward there being less
severe weather in our CWFA than previously expected, with the
primary threat for severe storms further north/northeast in
southeast IA and central IL. A broad area of showers and stratiform
rain associated with an MCV which is spinning its way across the
state is putting the kibosh on much of the instability which was
forecast for late this afternoon/evening. A limited ribbon of very
high CAPE (MLCAPE in excess of 3500-4000 J/Kg) remains over extreme
northeast MO into southern IA and a much larger area of high CAPE
over central and southern IL. Storms are already rumbling just
north of our CWFA in southern IA and west central IL and I would
expect these areas of storms to continue to develop and strengthen.
Still cannot rule out severe storms from Kirksville to Quincy and
southeast to Litchfield and possibly Salem...but the probability
seems to be much lower than previously expected.
After the evening severe weather threat has passed, there is still
the possibility that there could be additional development
overnight. RAP and NAM both show moderate moisture convergence at
850mb ahead of the front and generate QPF in response. Have left
chance/slight chance PoPs going for most of the area through the
night. The wind shift associated with the approaching cold front
should be sliding into the northern 1/3 of our CWFA between 09-12Z
with drier low level air trying to nose in. This should effectively
cut off the chance for additional precip in those areas in the
pre-dawn hours.
Carney
.LONG TERM: (Sunday through Next Saturday)
Issued at 340 PM CDT Sat Jul 26 2014
The cold front is expected to push through early Sunday morning. A
minimal rain threat will exist during the morning near it, with a
dry afternoon on tap behind it. The cooling effects will not be
felt too much early on, with another warm day expected: max temps
still look to top 90 degrees for most areas near and south of I-70.
The big difference will be lower humidity from today, however.
After Sunday, an extended dry period is forecast as a deep longwave
upper TROF sets up over eastern North America with a stout NW flow
aloft for our region. This usually means either dry, or surprise
hit-and-run systems this time of year, but almost always means below
average temps. For now, am going with dry until Thursday, with low
PoPs thereafter as a system works its way down into our region and
stays for a bit.
TES
&&
.AVIATION: (For the 18z TAFs through 18z Sunday Afternoon)
Issued at 1241 PM CDT Sat Jul 26 2014
Primary concern is thunderstorms this afternoon and evening.
Expecting the precipitation over west central/centra MO to
continue to move eastward. It is unclear yet how much these storms
will strengthen/expand, but some strong wind gusts and hail are
possible with this complex as it moves eastward. Another area of
concern will be in northeast MO/west central IL later this
afternoon/this evening where a complex of severe thunderstorms is
expected to develop and should move rapidly east-southeast. Wind
gusts in excess of 50kts and large hail will be possible with
this cluster. Still some uncertainty on the exact track of the
thunderstorm complex, though the most likely parts of the area to
be affected will be along and north of a line from KIRK to KSLO.
Afterthe storms move through this evening, expect VFR flight
conditions. A cold front will move through early Sunday morning
shifting the wind to the west-northwest.
Specifics for KSTL:
Primary concern at Lambert is the possibility of thunderstorms
early this evening. Current thinking is that the storms over
central/west central Missouri may not affect the terminal, but a
cluster of severe thunderstorms will develop over northern
MO/southern IA and race east-southeast. Think the best threat for
storms will be north of Lambert along and north of a line from
KIRK to KSLO. After storms clear the area this evening expect VFR
flight conditions to prevail. A cold front will pass through the
terminal early Sunday morning which will shift the wind to the
northwest.
Carney
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...HEAT ADVISORY until 7 PM CDT this evening FOR Franklin MO-
Jefferson MO-St. Charles MO-St. Louis City MO-St. Louis MO-
Warren MO.
IL...HEAT ADVISORY until 7 PM CDT this evening FOR Clinton IL-Madison
IL-Monroe IL-St. Clair IL-Washington IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
324 PM CDT Sat Jul 26 2014
.SHORT TERM: (Through Late Tonight)
Issued at 324 PM CDT Sat Jul 26 2014
Primary concern continues to be convective trends for this evening.
Current trends are pointing more and more toward there being less
severe weather in our CWFA than previously expected, with the
primary threat for severe storms further north/northeast in
southeast IA and central IL. A broad area of showers and stratiform
rain associated with an MCV which is spinning its way across the
state is putting the kibosh on much of the instability which was
forecast for late this afternoon/evening. A limited ribbon of very
high CAPE (MLCAPE in excess of 3500-4000 J/Kg) remains over extreme
northeast MO into southern IA and a much larger area of high CAPE
over central and southern IL. Storms are already rumbling just
north of our CWFA in southern IA and west central IL and I would
expect these areas of storms to continue to develop and strengthen.
Still cannot rule out severe storms from Kirksville to Quincy and
southeast to Litchfield and possibly Salem...but the probability
seems to be much lower than previously expected.
After the evening severe weather threat has passed, there is still
the possibility that there could be additional development
overnight. RAP and NAM both show moderate moisture convergence at
850mb ahead of the front and generate QPF in response. Have left
chance/slight chance PoPs going for most of the area through the
night. The wind shift associated with the approaching cold front
should be sliding into the northern 1/3 of our CWFA between 09-12Z
with drier low level air trying to nose in. This should effectively
cut off the chance for additional precip in those areas in the
pre-dawn hours.
Carney
.LONG TERM: (Sunday through Friday)
Issued at 330 AM CDT Sat Jul 26 2014
The cold front will extend from northeast Illinois to around St.
Louis into northern Oklahoma at 12z and should exit the CWA by
early afternoon as the upper low/trof moves southeastward into the
Great Lakes. The precipitation threat will be considerably lower
Sunday morning ahead of the front and I don`t expect to see much.
Increasing northwesterly winds will usher drier and cooler air
into the region during the afternoon in the wake of the front. The
large surface high will settle into the Nation`s midsection on
Monday and then become a dominant feature into midweek as a deep
upper trof persists over eastern NOAM. Below average temperatures
will prevail throughout next week.
Glass
&&
.AVIATION: (For the 18z TAFs through 18z Sunday Afternoon)
Issued at 1241 PM CDT Sat Jul 26 2014
Primary concern is thunderstorms this afternoon and evening.
Expecting the precipitation over west central/centra MO to
continue to move eastward. It is unclear yet how much these storms
will strengthen/expand, but some strong wind gusts and hail are
possible with this complex as it moves eastward. Another area of
concern will be in northeast MO/west central IL later this
afternoon/this evening where a complex of severe thunderstorms is
expected to develop and should move rapidly east-southeast. Wind
gusts in excess of 50kts and large hail will be possible with
this cluster. Still some uncertainty on the exact track of the
thunderstorm complex, though the most likely parts of the area to
be affected will be along and north of a line from KIRK to KSLO.
Afterthe storms move through this evening, expect VFR flight
conditions. A cold front will move through early Sunday morning
shifting the wind to the west-northwest.
Specifics for KSTL:
Primary concern at Lambert is the possibility of thunderstorms
early this evening. Current thinking is that the storms over
central/west central Missouri may not affect the terminal, but a
cluster of severe thunderstorms will develop over northern
MO/southern IA and race east-southeast. Think the best threat for
storms will be north of Lambert along and north of a line from
KIRK to KSLO. After storms clear the area this evening expect VFR
flight conditions to prevail. A cold front will pass through the
terminal early Sunday morning which will shift the wind to the
northwest.
Carney
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 77 90 66 81 / 40 20 0 5
Quincy 71 84 61 77 / 70 10 5 10
Columbia 74 89 62 81 / 20 10 0 5
Jefferson City 75 89 63 81 / 20 10 0 5
Salem 73 90 63 79 / 60 30 0 5
Farmington 75 91 61 80 / 20 30 0 0
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...HEAT ADVISORY until 7 PM CDT this evening FOR Franklin MO-
Jefferson MO-St. Charles MO-St. Louis City MO-St. Louis MO-
Warren MO.
IL...HEAT ADVISORY until 7 PM CDT this evening FOR Clinton IL-Madison
IL-Monroe IL-St. Clair IL-Washington IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1214 PM CDT Sat Jul 26 2014
.UPDATE...
Issued at 1033 AM CDT SAT JUL 26 2014
A MCV over northeastern Kansas is throwing a few wrinkles into the
going forecast. First, cloud cover is limiting how quickly we are
warming up so far this morning and with the bulk of the MCV yet to
track over the area it seems thicker cloud cover will persist through
much of today. This will continue to hold back temperatures through
at least early this afternoon. To account for this, have lowered
temperatures 2 to 3 degrees/ hr which resulted in about a 2 to 3
degree decrease in max temperatures. Dewpoints are tracking well but
with lower temperatures heat indices are now around 100 to as warm as
103.
The second concern is that this MCV will allow convection to
redevelop ahead of it. This is already occurring with isolated to
scattered showers and a few storms being triggered in the unstable
environment due to forcing from the MCV. Have increased or added
precipitation chances across mainly the northern two-thirds of the
forecast area to account for this. While there is ample instability
for this convection, shear is very weak at this point in time, so the
threat of severe weather is low.
The other item we`re watching is intense convection entering
northeastern Nebraska that is on a trajectory towards the forecast
area. This area seems to be mainly driven by a shortwave moving
around western ridge. It`s possible this area may move into northern
Missouri later this afternoon/early this evening. The question though
is if the stronger shear helping to sustain that convection can
build further south as well. The HRRR has started indicate this
system moving into the area but decreasing in strength. However
broader scale models and mesoanalysis show shear increasing across
northern Missouri so there appears to be some potential for either
the ongoing convection or new convection to develop across northern
Missouri and potentially become severe later this afternoon.
&&
.DISCUSSION...
Issued at 403 AM CDT SAT JUL 26 2014
The main weather concerns for this forecast package will reside in
the first 24 hours. The first of the concerns today will revolve
around the heat. The second concern will revolve around
precipitation chances late this afternoon into tonight and the
severe potential surrounding them.
Looking at 850mb temperature this morning and models continue to
range between 24C-28C. Providing we can mix up to that layer that
will yield highs in the 90s. However, there are a couple of caveats
(other than mixing) to this temperature forecast. The first is cloud
cover. There is a complex of thunderstorms currently heading east
across central Kansas. As this complex moves across central and into
eastern Kansas it is forecast to weaken as the LLJ veers. Of some
concern however is that some of the hi-res models such as the
HRRR/RAP hold it together long enough to move into our local area
providing from additional cloud cover. As such have lowered
temperatures a degree or two. However, heat indices should still
reside in the 102-107 range across the western CWA where a heat
advisory is in place from 1PM to 8PM. The second caveat will be the
potential for storms and what time they will initiate. The first
possibility is that one mentioned previously where thunderstorms
across Kansas move east and refire this afternoon. The second
scenario would be thunderstorms developing this evening along a cold
front which is currently extending from north central Iowa into
extreme northwestern Missouri and into northern Kansas. In either
scenario, strong instability will be in place with 2500-3500J/Kg of
CAPE will be available, along with steep mid level lapse rates, and
strong shear. As such storms that do develop will have the potential
to be severe with damaging winds and large hail being the primary
threats.
The cold front will be forced through the forecast area tonight as
an unseasonably strong upper trough moves from south central Canada
into the Upper Midwest. This will continue thunderstorm chances into
the night time hours.
By Sunday morning the front will shift south of the area. Northwest
flow aloft will bring cooler temperatures with highs in the 80s on
Sunday. A secondary cold front will move through the area on Sunday
night. This will bring another round of cooler July air to the area
Monday through Wednesday as the upper level flow remains out of the
northwest. Expect highs during this period to range from the upper
70s to lower 80s. Precipitation chances will increase on Thursday
and Friday as the medium range models depict the potential for upper
shortwaves moving through the area on continued northwest flow.
Precipitation during this timeframe as well as northwest flow will
keeps highs below normal in the low to mid 80s.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 1213 PM CDT SAT JUL 26 2014
The ongoing showers/storms in the area should move east of the
terminals within an hour or two of issuance. The focus then shifts to
what the storms in northeastern Nebraska will do. On their current
path, they should stay to the northeast of the terminals and possibly
move through northern/northeastern Missouri. Latest guidance suggest
this line will weaken/erode as it begins to build into the area
though. So there is quite a bit of uncertainty still but confidence
is higher that this developing complex will not impact the terminals.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...HEAT ADVISORY until 8 PM CDT this evening FOR KSZ025-057-060-
102>105.
MO...HEAT ADVISORY until 8 PM CDT this evening FOR MOZ020-021-028-029-
037-043-053.
&&
$$
UPDATE...CDB
DISCUSSION...73
AVIATION...CDB
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1236 PM CDT SAT JUL 26 2014
.UPDATE...
ISSUED AT 1231 PM CDT SAT JUL 26 2014
CLOUD COVER CONTINUES TO INCREASE OVER THE AREA AS A LOW SHIFTS
THROUGH SOUTHERN MANITOBA. HAVE EXPANDED DENSER CLOUD COVER
FURTHER TO THE SOUTH TO MATCH GOING TREND. HAVE ALSO EXPANDED LOW
PRECIP CHANCES FURTHER TO THE SOUTH AND EAST TO MATCH THE GOING
TREND OF LIGHT DEVELOPING ACTIVITY ALONG WITH HIGH-RES MODEL
OUTPUT. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 923 AM CDT SAT JUL 26 2014
GOING FORECAST IN PRETTY GOOD SHAPE WITH LOW PASSING TO THE NORTH
OF THE AREA WITH WINDS CONTINUING TO INCREASE. ONLY CHANGE WAS TO
ADJUST CLOUD COVER UP A BIT OVER NORTHERN ZONES AS IT WORKS IN
BEHIND AFOREMENTIONED LOW. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 633 AM CDT SAT JUL 26 2014
HRRR MODEL SO FAR CORRECTLY FORECAST SURFACE TROUGH PASSAGE AND
BAND OF CLOUDS ACROSS THE SOUTH CENTRAL. BELIEVE THIS FEATURE
WILL REMAIN DRY WITH SCATTERED SHOWERS SOUTH IN SOUTH DAKOTA. TO
THE NORTH...UPPER LEVEL LOW WILL BRING INCREASING NORTHWEST WINDS
AND SCATTERED SHOWERS TO THE NORTH TODAY. CURRENT FORECAST LOOKS
GOOD.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 322 AM CDT SAT JUL 26 2014
THE LATEST SATELLITE IMAGERY SHOWS A COMPACT CLOSED UPPER LOW
CIRCULATING OVER SOUTHEAST SASKATCHEWAN. A 1003MB SURFACE LOW WAS
LOCATED OVER WYNYARD SASKATCHEWAN...DIRECTLY BENEATH THE UPPER LOW.
AS A RESULT...THE LOW CONTINUES TO FILL/WEAKEN WITH TIME. ATTACHED
TO THE LOW IS A COLD FRONTAL BOUNDARY EXTENDING FROM SOUTHEAST
SASKATCHEWAN INTO MINOT AND GARRISON...AND CONTINUING SOUTH TO
GLEN ULLIN AND HETTINGER. COLD AIR ADVECTION TODAY COMBINED WITH A
DECENT PRESSURE GRADIENT SETTING UP FROM EASTERN MONTANA TO
NORTHWEST MINNESOTA WILL RESULT IN WINDY CONDITIONS. AS IS USUALLY
THE CASE...INCLUDING TODAYS DATA...THE MET/NAM WIND GUIDANCE IS
WEAKER THAN THE MAV/GFS. THE LATEST RAP13 AND ECMWF FAVORS THE
LOWER END OF STRONGEST WINDS. THIS ULTIMATELY SUGGESTS A WEAK
CONFIDENCE LEVEL FOR A WIND ADVISORY. WOULD LIKE TO MORE AGREEMENT
AMONGST THE FORECAST DATA WITH HIGHER SUSTAINED WINDS. THUS HAVE
DECIDED TO HOLD OFF ON ISSUING A WIND ADVISORY AS IT REMAINS
MARGINAL AT THIS TIME. THE DAY SHIFT CAN HAVE ANOTHER LOOK AS WINDS
INCREASE BY MID/LATE MORNING TO COMPARE ACTUAL VERSUS FORECAST.
OTHERWISE THE LATEST FOG/STRATUS LOOP SHOWS A LARGE SWATH OF
LOW/MID LEVEL BKN/OVC CLOUDS ASSOCIATED WITH THE SURFACE/UPPER LOW
CIRCULATION OVER SOUTHERN SASKATCHEWAN. THESE ARE NOW BEGINNING TO
CROSS THE NORTHWEST CORNER OF THE STATE. THE HRRR SHOWS THIS BAND
OF CLOUDS ARCING INTO WILLISTON AND MINOT BETWEEN 16Z-17Z. THERE
WILL BE AN AREA OF ISOLATED TO SCATTERED RAINSHOWERS AND ISOLATED
THUNDERSTORMS OVER THE NORTH CENTRAL TODAY. THE NAM WAS MOST
AGGRESSIVE IN GENERATING PRECIPITATION INTO SOUTH CENTRAL NORTH
DAKOTA THIS AFTERNOON. BUT WITH ALL OTHER MODELS MAINTAINING THE
THREAT OVER THE NORTH...HAVE DISCOUNTED THE NAM AND CONTINUED/REFINED
WITH WHAT THE PREVIOUS FORECAST HAD. HIGHS TODAY IN THE NORTH WITH
MOSTLY CLOUDY/WINDY/WET CONDITIONS WILL REACH THE UPPER 60S.
IN THE CENTRAL AND SOUTH...EXPECT MOSTLY SUNNY AND WINDY WEATHER
WITH HIGHS AROUND 80.
ALSO...SHOWERS AND THUNDERSTORMS HAVE DEVELOPED OVER CENTRAL AND
NORTHERN SOUTH DAKOTA ALONG AND NORTH OF A LOW LEVEL CONVERGENCE
FIELD/FRONTAL BOUNDARY. THERE IS SOME HINT PER RAP13 THAT SHOWERS
WILL ENTER FAR SOUTHERN NORTH DAKOTA THROUGH 15Z SATURDAY. WILL
CONTINUE TO MONITOR THIS AND ADJUST AT THE LAST MINUTE IF TRENDS
CONTINUE TO SHOW DEVELOPMENT FARTHER NORTH.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 322 AM CDT SAT JUL 26 2014
THE EXTENDED PERIOD BEGINS THE AN UPPER LOW OVER SOUTH CENTRAL
CANADA THAT WILL MOVE SOUTHEAST AND MERGE INTO A LARGE HUDSON BAY
TROUGH SETTING UP A BLOCKING PATTERN ACROSS EASTERN NORTH AMERICA
WHICH WILL MAINTAIN A RIDGE OVER THE WESTERN US AND A TROUGH OVER
THE EAST. THE NORTHERN PLAINS WILL BE IN FOR A PERIOD OF QUIET
WEATHER FOR THIS EXTENDED PERIOD. FOR THE FIRST PORTION OF THE
FORECAST...SUNDAY THROUGH WEDNESDAY...EXPECT MAINLY DRY WEATHER
WITH A SLOW WARMING TREND. HIGHS IN THE UPPER 60S TO MID 70S ON
SUNDAY WILL MODERATE TO THE LOWER TO MIDDLE 80S BY WEDNESDAY
THROUGH FRIDAY. WITH THE H500 RIDGE FIRMLY IN PLACE OVER THE
WESTERN US ONLY A FEW WEAK IMPULSES MAY BE ABLE TO DRIFT ACROSS
THE NORTHERN PLAINS. FOR THIS POSSIBILITY LEFT WIDELY SCATTERED
CHANCES FOR THUNDERSTORMS WEDNESDAY WITH THURSDAY AND FRIDAY
BASICALLY DRY AND WARM.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1231 PM CDT SAT JUL 26 2014
SCT -SHRA AND ISOLD -TSRA WILL BE POSSIBLE MAINLY OVER NORTHERN
AND EASTERN PORTIONS OF NORTH DAKOTA TODAY INTO THIS EVENING. LCL
MVFR CIGS WILL BE POSSIBLE...MAINLY OVER FAR NORTHERN NORTH
DAKOTA. LATER TONIGHT...MVFR WITH LCL IFR CIGS ARE EXPECTED TO
DEVELOP OVER PORTIONS OF CENTRAL AND EASTERN NORTH DAKOTA.
CONDITIONS WILL IMPROVE BY MID-MORNING. GUSTY WEST TO NORTHWEST
WINDS OVER THE AREA TODAY WILL SUBSIDE THIS EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...KS
LONG TERM...WAA
AVIATION...JJS
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SYNOPSIS...
ISSUED AT 236 PM CDT SAT JUL 26 2014
SCATTERED SHOWERS AND THUNDERSTORMS FOR THE REST OF THE WEEKEND...
THEN MUCH COOLER EARLY NEXT WEEK.
MAJOR AMPLIFICATION OF THE LNGWV PATTERN INVOF NOAM WILL OCCUR
THE NEXT COUPLE DAYS AS CLOSED UPR LOW CURRENTLY OVER THE LAKE
WINNIPEG REGION SHIFTS E AND THEN TURNS SE. IN ADDITION TO THE
RESULTING UPR TROF OVER THE LOWER GREAT LAKES RGN...ANOTHER LNGWV
TROF WL BE OFF THE BRITISH COLUMBIA COAST...AND A STG RIDGE WL BE
ANCHORED OVER THE INTERMOUNTAIN WEST. THE DEVELOPING PATTERN WL BE
VERY STABLE. ONCE IN PLACE...IT WILL REMAIN IN PLACE THROUGH THE
REMAINDER OF THE FCST PERIOD. BUT GRADUAL MODIFICATION OF THE COLD
AIR WITHIN THE TROFS WL ALLOW THE FLOW ACRS THE CONUS TO
WEAKEN...AND THE MAIN WESTERLIES TO REFORM BACK N ACRS CANADA.
WARM AND HUMID CONDITIONS AT THE START OF THE FCST PERIOD WL
QUICKLY BE REPLACED BY MUCH COOLER AND DRIER CONDITIONS FOR THE
START OF THE WORK WEEK. THEN TEMPERATURES WL GRADUALLY REBOUND
BACK TO SEASONAL NORMALS AS THE COOL AIR ACRS THE REGION
MODIFIES.
THE BEST CHC FOR SIG PCPN WL BE EARLY IN THE FCST PERIOD...AS THE
UPR LOW CROSSES THE RGN. BUT THE COVERAGE OF THE SIG PCPN WITH
THE UPR LOW IS LIKELY TO BE SCT...AND THE GENERAL NWLY UPR FLOW
THAT WL DOMINATE THE AREA FOR THE REMAINDER OF THE PERIOD FAVORS
BLO NORMAL PCPN AMNTS. THE LACK OF PCPN ACRS MUCH OF THE AREA THE
PAST FEW WEEKS IS BECOMING APPARENT IN THE FORM OF BROWN LAWNS AND
SLUGGISH GROWTH OF CROPS IN AREA FARMS. PCPN TOTALS FOR THE PAST
30 DAYS HAVE GENERALLY ONLY BEEN 25-50 PCT OF NORMAL ACRS MOST OF
THE FCST AREA. OVER THE PAST COUPLE WEEKS...THE MOST SIG PCPN
DEFICIT HAS BEEN OVER E-C WI...WHERE PCPN TOTALS HAVE BEEN LESS
THAN 25 PCT OF NORMAL.
&&
.SHORT TERM...TONIGHT AND SUNDAY
ISSUED AT 236 PM CDT SAT JUL 26 2014
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A WEAK AREA
OF LOW PRESSURE MOVING EAST OVER LAKE SUPERIOR AND SURFACE TROUGH
AXIS EXTENDING SOUTHWEST FROM THIS SURFACE LOW ACROSS NORTHWEST
WISCONSIN. A BROKEN LINE OF THUNDERSTORMS HAVE DEVELOP ALONG THIS
TROUGH AXIS OVER THE CENTRAL UPPER PENINSULA BUT THINK THEY WILL
REMAIN NORTH OF THE BORDER FOR THE REST OF THE AFTERNOON. THOUGH
LOW STRATUS REMAINS AHEAD OF THE TROUGH OVER NORTHEAST
WISCONSIN...CLEARING SKIES HAVE MOVED INTO NORTH-CENTRAL WISCONSIN
WHERE MIXING HAS DROPPED DEWPOINTS INTO THE LOWER AND MIDDLE 50S. AN
AREA OF CIRRUS WILL CONTINUE TO MOVE EAST OVER CENTRAL AND
EAST-CENTRAL WISCONSIN THIS AFTERNOON FROM THUNDERSTORMS OVER THE
CENTRAL PLAINS. OTHERWISE...THE FOCUS FOR THE NEXT 24 HOURS WILL
REVOLVE AROUND THE UPPER LOW OVER SOUTH-CENTRAL CANADA. AS IT MOVES
SOUTHEAST...THE POTENTIAL FOR STRONG TO SEVERE THUNDERSTORMS IS THE
MAIN FORECAST CONCERN LATE TONIGHT INTO SUNDAY.
TONIGHT...THE UPPER LEVEL LOW AND ASSOCIATED OCCLUDED FRONT WILL
DIVE SOUTHEAST INTO NORTHWEST AND NORTH-CENTRAL RESPECTIVELY BY LATE
TONIGHT. AHEAD OF THESE FEATURES...MODELS DEPICT A RELATIVELY
NARROW RIBBON OF HIGHER THETAE ABOVE THE NOCTURNAL INVERSION THAT
MOVES INTO N-C WISCONSIN BY 09Z AND THE FOX VALLEY TO IRON MOUNTAIN
CORRIDOR BY 12Z. WITHIN THIS THETAE RIBBON...MODELS ESTIMATE
ELEVATED CAPES BETWEEN 500-1000 J/KG WHICH SUPPORTS A CHANCE OF
THUNDERSTORMS. QG FORCING WILL BE INCREASING AT THE SAME TIME AND
PWATS WILL BE NEARING 1.5 INCHES. SO WILL SHOW PRECIP CHANCES IN
THE LIKELY RANGE OVER NORTH-CENTRAL WISCONSIN AFTER MIDNIGHT WITHIN
THE DEFORMATION ZONE AND A CHANCE ELSEWHERE. IF STORMS DO
DEVELOP...SOME COULD CONTAIN SUB-SEVERE SIZED HAIL. EFFECTIVE
SHEARS 20-25 KNOTS SUGGESTS SEVERE STORMS ARE UNLIKELY.
SUNDAY...THE UPPER LOW WILL MOVE ACROSS OUR AREA DURING THE MORNING
AND EXIT OVER SOUTHERN LAKE MICHIGAN BY LATE IN THE AFTERNOON.
BENEATH THE UPPER LOW...AMPLE MOISTURE COMBINED WITH STEEP LOW LEVEL
LAPSE RATES WILL LEAD TO THE DEVELOPMENT OF SHOWERS AND A FEW
THUNDERSTORMS BY LATE IN THE MORNING. WET BULB ZERO TEMPS BELOW
10KFT WILL PROVIDE A THREAT OF HAIL WITHIN ANY THUNDERSTORMS AND
WOULD NOT BE SURPRISED IF AN ISOLATED STORM OR TWO APPROACHES SEVERE
LIMITS. WILL KEEP THIS MENTION IN THE HWO. HIGHS COOLING TO THE
MIDDLE 60S NORTH TO MIDDLE 70S SOUTH.
.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY
ISSUED AT 236 PM CDT SAT JUL 26 2014
PCPN WITH THE DEPARTING UPR LOW COULD LINGER INTO SUN EVE...ESP
IN THE EAST. MAINTAINED CHC POPS FOR THE EVENING. ALTHOUGH IT/S
NOT OUT OF THE QUESTION THAT SOMETHING COULD LINGER PAST
MIDNIGHT...THERE WAS NOT ENOUGH SUPPORT FOR THAT TO DRAG POPS
THROUGH THE WHOLE NIGHT. SINCE WINDS WL LIKELY STAY UP DURING THE
NGT AND COOLER AIR WL FIRST BE WORKING INTO THE AREA...EDGED MINS
TOWARD A BLEND OF THE WARMER GUIDANCE PRODUCTS.
THE FCST AREA WL STILL BE ON THE CYCLONIC SIDE OF THE UPR JET
MON...SO ANY SML SCALE DISTURBANCE THAT WORKS ACRS THE AREA
DURING THE AFTN COULD EASILY GENERATE ISOLD-SCT SHRA. BUT WITH NO
FORCING APPARENT ON THE MODELS ATTM...KEPT FCST DRY. IT LOOKS LIKE
A DISTURBANCE WL DROP SWD ACRS THE AREA TUE...SO KEPT CHC POPS AT
THAT TIME.
SIG MOISTURE WL REMAIN WELL S OF THE AREA FOR THE REST OF THE
FCST PERIOD...SO THE PROSPECT FOR SIG WIDESPREAD PCPN DOES NOT
LOOK GOOD. BUT THERE WL STILL BE AMPLE OPPORTUNITIES FOR SCT LGT
PCPN AS SML SCALE SHRTWVS DROP SEWD ACRS THE AREA. CONFIDENCE IN
THE TIMING THOSE CHCS DIMINISHES RAPIDLY AS ONE GOES FARTHER OUT
INTO THE FCST.
NO SIG CHGS WERE NEEDED TO THE BROAD-BASED EXTENDED FCST
INITIALIZATION GRIDS.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1153 AM CDT SAT JUL 26 2014
DRIER AIR IS GRADUALLY MOVING ACROSS NORTH-CENTRAL AND
NORTHEAST WISCONSIN FROM THE NORTHWEST LATE THIS MORNING. CLOUDS HAVE BEEN
DISSIPATING THIS MORNING OVER N-C WISCONSIN WITH THE ARRIVAL OF THIS
DRIER AIR...AND THIS TREND SHOULD MOVE INTO NORTHEAST WISCONSIN BY
EARLY THIS AFTERNOON. THEN ONCE CIGS LIFT AND SCATTER...VFR
CONDITIONS WILL REMAIN PRESENT THROUGH THE EVENING. AFTERWARDS...AN
UPPER LEVEL LOW WILL DROP SOUTHEAST INTO NORTHERN WISCONSIN
OVERNIGHT INTO SUNDAY MORNING. SPOTTY SHOWERS AND A FEW
THUNDERSTORMS ARE POSSIBLE AHEAD OF THIS SYSTEM OVERNIGHT...THEN
WIDESPREAD SHOWERS AND SCATTERED THUNDERSTORMS ARE LIKELY TO DEVELOP
SUNDAY MORNING ALONG WITH LOWERING CIGS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS.......SKOWRONSKI
SHORT TERM.....MPC
LONG TERM......SKOWRONSKI
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1229 PM CDT SAT JUL 26 2014
.UPDATE...
ISSUED AT 748 AM CDT SAT JUL 26 2014
THE 26.06Z DETERMINISTIC AND MESO MODELS CONTINUE TO SUGGEST THAT
THERE WILL BE STRONG 900 TO 500 MB FRONTOGENETIC FORCING MAINLY
SOUTH OF INTERSTATE 90 TODAY. VAD WIND PROFILERS SHOW A 30 TO 45
KNOT CONVERGENCE INTO THE 700 MB FRONT ACROSS SOUTHWEST MINNESOTA.
OVERALL THE HRRR AND A COUPLE /MEMBERS 2 AND 3/ OF THE 26.06Z HOP
WRF SHOW THAT THE PRECIPITATION CURRENTLY OVER EASTERN SOUTH
DAKOTA AND SOUTHWEST MINNESOTA WILL CONTINUE TO SPREAD EAST INTO
THE AREAS MAINLY SOUTH OF INTERSTATE 90. DUE TO THIS...RAISED THE
CHANCES OF SHOWERS UP SIGNIFICANTLY. THERE WILL BE EVEN ENOUGH
INSTABILITY ALOFT FOR ISOLATED THUNDERSTORMS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CDT SAT JUL 26 2014
LATEST WATER VAPOR SATELLITE IMAGERY INDICATING UPPER LEVEL CLOSED
LOW OVER SOUTHERN SASKATCHEWAN AND WEST TO EAST ZONAL FLOW OVER
THE NORTHERN PLAINS. WEAK SHORTWAVE TROUGH OVER CENTRAL AND
EASTERN SOUTH DAKOTA EMBEDDED IN WEST TO EAST ZONAL FLOW IS
PRODUCING SHOWERS AND ISOLATED THUNDERSTORMS OVER CENTRAL SOUTH
DAKOTA PER MOSAIC RADAR.
MAIN FORECAST CONCERNS ARE PRECIPITATION CHANCES TODAY INTO TONIGHT.
THE 26.00Z GFS/NAM ARE IN GOOD AGREEMENT IN MOVING WEAK IMPULSE OVER
CENTRAL SOUTH DAKOTA INTO THE SOUTHERN PART OF THE FORECAST AREA.
THE 26.00Z GFS/NAM ARE INDICATING ISENTROPIC LIFT AT 315K SURFACE
AND PRODUCE LIGHT QPF ACROSS PARTS OF NORTHEAST IOWA AND SOUTHWEST
WISCONSIN. THE LATEST 26.05Z HRRR IS INDICATING THE SHRA/TSRA OVER
CENTRAL SOUTH DAKOTA TO WEAKEN AND POSSIBLY PRODUCE LIGHT SHOWERS OR
SPRINKLES OVER THE SOUTHERN PART OF THE FORECAST AREA. BUFKIT
SOUNDINGS SHOW QUITE A BIT OF DRY AIRMASS BELOW 700MB OVER THE
SOUTHERN FORECAST AREA. HOWEVER...WITH THE LIFT ASSOCIATED WITH THE
WEAK IMPULSE...THIS MAY PRODUCE AN ISOLATE SHRA/TSRA ACROSS SOUTHERN
FORECAST AREA THIS MORNING INTO THE EARLY AFTERNOON HOURS. HAVE
INTRODUCE A SMALL CHANCE OF PRECIPITATION OVER NORTHEAST IOWA AND
PARTS OF SOUTHWEST WISCONSIN.
UPPER LEVEL CLOSED LOW OVER SOUTHERN SASKATCHEWAN MOVES SOUTH
INTO THE GREAT LAKES REGION TONIGHT. THE 26.00Z GFS/NAM SUGGEST
INCREASING FORCING/LIFT AFTER 06Z OVER NORTHERN PARTS OF THE
FORECAST AREA AND INDICATE ELEVATED CAPE ASSOCIATED WITH UPPER
LEVEL CLOSED LOW. WILL CONTINUE TREND OF PRECIPITATION CHANCES
ACROSS THE NORTHERN PARTS OF THE FORECAST AREA.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 320 AM CDT SAT JUL 26 2014
SUNDAY...THE 26.00Z GFS/NAM CONTINUE TO SHOW DECENT 500-300MB PV
ADVECTION AND DEEP QG FORCING ASSOCIATED WITH THE CLOSED UPPER LEVEL
LOW OVER MUCH OF THE NORTHERN AND EASTERN PART OF THE FORECAST
AREA. CONFIDENCE IS INCREASING THIS AREA WILL SEE SHOWERS AND
POSSIBLY AN ISOLATED THUNDERSTORM.
THE 26.00Z GFS/GEM/ECMWF ARE IN GOOD AGREEMENT DIGGING UPPER LEVEL
TROUGH OVER THE EASTERN UNITED STATES SUNDAY NIGHT INTO FRIDAY. THE
MAIN DIFFERENCE BETWEEN THE MODELS IS TIMING THE VERY WEAK IMPULSES
EMBEDDED IN THE NORTHERLY FLOW ALOFT INTO THE GREAT LAKES REGION.
THE MODELS CONTINUE TO PRODUCE LIGHT QPF OVER PARTS OF THE
FORECAST AREA MAINLY FROM WEDNESDAY INTO FRIDAY. HOWEVER...WITH
VERY WEAK MOISTURE CONVERGENCE AND VERY WEAK IMPULSES EMBEDDED IN
NORTHERLY FLOW. CONFIDENCE IN PRECIPITATION CHANCES IS LOW THROUGH
THIS PERIOD.
TEMPERATURES SUNDAY NIGHT INTO FRIDAY WILL BE UNSEASONABLY COOL
THROUGH MIDDLE OF THE WEEK AND MODERATE TO NEAR NORMAL BY END OF THE
WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1219 PM CDT SAT JUL 26 2014
COMPLEX OF SHOWERS AND STORMS OVER EASTERN SD THIS MORNING HAS
SHIFTED SOUTHEAST INTO WESTERN IA/EASTERN NEB. COOL OUTFLOW
SHOWERS IN MID LEVEL CONVERGENT AREA STRINGING EAST ALONG THE
MN/IA BORDER REGION. LITTLE MORE THAN SPRINKLES AT THE KRST/KLSE
AIRFIELDS...BUT MORE SHOWERS LOOK TO IMPACT KRST FOR THE EARLY
AFTERNOON. COMPLEX SHIFTING SLIGHTLY SOUTH OF EAST SO CONFIDENT IT
WILL MISS KLSE. STILL...LOW CLOUD LINGERING IN THE WEAK FLOW
ENVIRONMENT KEEPING INVERSION IN PLACE. DO FEEL THE LOWER CLOUD
WILL MIX OUT ONCE THE SHOWER AREA PASSES BY MID TO LATE AFTERNOON.
MEANWHILE A NICE SHORT WAVE TROUGH IS MOVING THROUGH SOUTHERN
CANADA NEAR WINNIPEG WILL DROP SOUTHEAST ACROSS MN TONIGHT AND
INTO WI BY SUNDAY. DESPITE MINIMAL MOISTURE AVAILABLE...STRONG
FORCING AND STEEP MID-LEVEL LAPSE RATES LOOK TO FORCE STORMS
DURING THE EVENING/OVERNIGHT HOURS. BUT THESE LOOK TO REMAIN WELL
NORTH AND EAST OF THE TAF LOCATIONS. ONLY IMPACT WILL PERHAPS BE
SOME CLOUD COVER AND A WIND SWITCH TO NORTHWEST. BEHIND THE UPPER
SYSTEM EXPECT LOW LEVEL MOISTURE TO MANIFEST AS CLOUD AND GUSTY
WINDS TOMORROW.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...BOYNE
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...MW