Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/26/12
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
901 AM MST TUE JUL 24 2012
.SYNOPSIS...
THUNDERSTORM CHANCES WILL BEGIN TO DECREASE OVER THE NEXT FEW DAYS
AS DRIER AIR SLOWLY WORKS IN FROM THE WEST. AFTER TODAY...STORM
CHANCES WILL MAINLY BE CONFINED TO THE HIGHER TERRAIN AREAS EAST OF
PHOENIX. DRIER AND SLIGHTLY WARMER WEATHER WILL SETTLE ACROSS THE
REGION FOR LATE THIS WEEK INTO THE WEEKEND...BEFORE A MORE ACTIVE
MONSOON PATTERN IS POSSIBLE BY THE EARLY PART OF NEXT WEEK.
&&
.DISCUSSION...
OVERNIGHT SCATTERED SHOWERS AND THUNDERSTORMS MAINLY EAST OF PHOENIX
CONTINUE TO REDEVELOP ACROSS FAR NORTHERN PINAL AND SOUTHERN GILA
COUNTIES. A SIGNATURE OF AN MCV CAN BE SEEN ON RADAR EARLIER THIS
MORNING OVER GILA COUNTY...WHILE THE LATEST 12Z NAM SHOWS A SMALL
500 MB CIRCULATION CENTERED OVER EAST-CENTRAL ARIZONA. DECENT
700-500 MB OMEGA FROM A FLAGSTAFF TO JUST EAST OF PHOENIX LINE AND
EAST...ALONG WITH A GOOD LOW LEVEL MOISTURE GRADIENT CONTINUE TO
FUEL THE ONGOING CONVECTION. COULD CONTINUE TO SEE SHOWERS REDEVELOP
INTO THE LATE MORNING HOURS ACROSS PINAL AND GILA COUNTIES DEPENDING
ON HOW QUICKLY THE MCV MOVES EASTWARD. THIS ACTIVITY WILL LIKELY
HINDER CHANCES LATER TODAY AS THE EXTENSIVE CLOUD DECK WILL BE SLOW
TO BURN OFF IF IT ACTUALLY EVER DOES. INCREASED POPS EAST OF PHOENIX
IN THE NEAR-TERM...AND WILL HAVE TO KEEP MONITORING THE SITUATION
FOR ANY FURTHER ADJUSTMENTS NEEDED FOR THIS AFTERNOON.
ELSEWHERE...NORTHWESTERLY FLOW AND DRY AIR IS WORKING IT/S WAY
EASTWARD THROUGH WESTERN ARIZONA AND WILL LIKELY PUSH INTO MUCH OF
CENTRAL ARIZONA THIS AFTERNOON. AFTERNOON SLIGHT CHANCE POPS ACROSS
PORTIONS OF SOUTHWEST AND SOUTH-CENTRAL ARIZONA ARE STILL LOOKING
GOOD. THERE SHOULD BE ENOUGH HEATING AND RESIDUAL MOISTURE TO SPARK
OFF A FEW SHOWERS AND THUNDERSTORMS ACROSS HIGHER TERRAIN AREAS OF
THE LOWER DESERTS THIS AFTERNOON. HOWEVER...WARMING IN THE MID
LEVELS AND THE DRYING NORTHWESTERLY FLOW WILL DEFINITELY HINDER
DEVELOPMENT AREAS WEST OF MARICOPA COUNTY TODAY.
&&
.PREVIOUS DISCUSSION...
CONVECTION CONTINUES FROM GILA TO YAVAPAI COUNTIES THIS
MORNING...SENDING OUTFLOWS INTO THE VALLEY AND SPAWNING ISOLATED
SHOWERS AND THUNDERSTORMS AS FAR WEST AS THE ESTRELLA MOUNTAINS AS
OF 2 AM. NOT MUCH IN THE WAY OF SEVERE WEATHER PER SE...BUT THERE
HAVE BEEN REPORTS OF NEARLY 2 INCHES OF RAIN SINCE APPROX 10PM LAST
EVENING WITH THE STRONGEST STORMS. ONLY THE HRRR MODEL HAS ANY SENSE
OF WHATS GOING ON AT THE MOMENT...SHOWING STORMS DIMINISHING AROUND
12Z. WITH THIS IN MIND...I WILL MAINTAIN A CHANCE OF SHOWERS AND
THUNDERSTORMS IN THE FORECAST THROUGH THE PRE-DAWN HOURS EAST OF
PHOENIX.
ONGOING CONVECTION AND NUMEROUS OUTFLOWS ARE WREAKING HAVOC ON OUR
PRECIP CHANCES FOR LATER TODAY. ATMOSPHERE REMAINS PRIMED FOR
CONVECTION AT THE MOMENT PROVIDED THERE IS ENOUGH FORCING IN
PLACE...BUT MOISTURE WILL BEGIN ERODING FROM THE WEST LATER THIS
AFTERNOON AND CONSEQUENTLY...INSTABILITY IS EXPECTED TO DIMINISH
RAPIDLY BY 00Z. ON TOP OF THAT...THE ATMOSPHERE WILL ALMOST
CERTAINLY BE WORKED OVER ACROSS THE HIGHER TERRAIN. WHILE IT APPEARS
THERE IS STILL A CHANCE OF STORMS LATER TODAY...I HAVE REDUCED POPS
GIVEN THE ABOVE CONCERNS. AREAL COVERAGE AND EXTENT OF STORMS WOULD
HAVE BEEN LESSER TODAY ANYWAY GIVEN ERODING MOISTURE BUT I THINK
THIS OVERNIGHT COMPLEX WILL LESSEN COVERAGE EVEN MORE.
A BIT OF A BREAK FROM THE MONSOON LOOKS LIKELY FROM WEDNESDAY
THROUGH SATURDAY AS MOISTURE DECREASES AND INSTABILITY DROPS TO
NOTHING. PRECIP CHANCES WERE CHANGED ONLY SLIGHTLY EACH
DAY...GENERALLY CLIMO MINUS 10 OR 15 PERCENT. SOME SUGGESTION OF AN
EASTERLY WAVE/INVERTED TROUGH MOVING THROUGH THE AREA LATE THIS
WEEKEND INTO EARLY NEXT WEEK. WITH THIS IN MIND...I STARTED BRINGING
POPS BACK INTO THE DESERTS ON SUNDAY AND MONDAY ALTHOUGH FIGURING
OUT THE EXACT TIMING THIS FAR IN ADVANCE IS TRICKY AT BEST.
&&
.AVIATION...
SOUTH CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
SHOWER AND THUNDERSTORM ACTIVITY OVER HIGHER TERRAIN NORTH AND EAST
OF THE PHOENIX AREA IS FINALLY TRENDING DOWN EARLY THIS MORNING.
SOME ISOLATED WEAK SHOWERS MAY STILL POP UP OVER THE METRO AREA
BEFORE 16Z BUT TOO LOW A PROBABILITY TO INCLUDE IN THE TAFS.
ANTICIPATE THUNDERSTORM ACTIVITY TO FLIRT WITH THE METRO AREA ONCE
AGAIN LATER TODAY AND TONIGHT WITH OUTFLOW WINDS CAUSING ERRATIC
WIND SHIFTS. NO WIDESPREAD STORM DEVELOPMENT IS ANTICIPATED OVER THE
METRO BUT STORMS CAN BE EXPECTED AFTER 23Z NEAR THE FOOTHILLS.
CONFIDENCE IN STORM OCCURRENCE AT THE TAF SITES NOT HIGH ENOUGH AT
THIS TIME TO INSERT TEMPO/PROB TSRA IN THE TAFS. OTHERWISE...WINDS
WILL BE LIGHT AND FAVOR TYPICAL DIURNAL PATTERNS.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
VERY ISOLATED SHOWERS OVER SOUTHEAST CALIFORNIA ARE ANTICIPATED TO
DISSIPATE BY 15Z AND MAY DRIFT OVER KBLH. OTHERWISE...STORM ACTIVITY
LATER TODAY IS EXPECTED TO BE EAST OF THE LOWER COLORADO RIVER
VALLEY. ANTICIPATE WINDS TO FOLLOW A SIMILAR PATTERN TO THE PREVIOUS
24 HOURS WITH AFTERNOON GUSTS A BIT STRONGER AT KBLH THAN YESTERDAY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
ATMOSPHERIC MOISTURE AND ASSOCIATED THUNDERSTORM ACTIVITY IS
EXPECTED TO BEGIN TRENDING UPWARD LATE THIS WEEK INTO EARLY NEXT
WEEK AS A WEATHER DISTURBANCE TRACKS WESTWARD ACROSS FAR NORTHERN
MEXICO. ACCORDINGLY...HUMIDITIES WILL TREND SLOWLY UPWARD FROM EAST
TO WEST. APART FROM THUNDERSTORMS...WINDS ARE EXPECTED TO FOLLOW
FAMILIAR WARM SEASON DIURNAL PATTERNS. THUNDERSTORM CHANCES ARE
EXPECTED TO REMAIN PRIMARILY EAST OF THE LOWER COLORADO RIVER
VALLEY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...KUHLMAN
PREVIOUS DISCUSSION...LEINS
AVIATION...AJ
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION...UPDATED
NWS PHOENIX AZ
535 AM MST TUE JUL 24 2012
.UPDATE...
UPDATED AVIATION AND FIRE WEATHER SECTIONS.
&&
.SYNOPSIS...
THUNDERSTORM CHANCES WILL BEGIN TO DECREASE OVER THE NEXT FEW DAYS
AS DRIER AIR SLOWLY WORKS IN FROM THE WEST. AFTER TODAY...STORM
CHANCES WILL MAINLY BE CONFINED TO THE HIGHER TERRAIN AREAS EAST OF
PHOENIX. DRIER AND SLIGHTLY WARMER WEATHER WILL SETTLE ACROSS THE
REGION FOR LATE THIS WEEK INTO THE WEEKEND...BEFORE A MORE ACTIVE
MONSOON PATTERN IS POSSIBLE BY THE EARLY PART OF NEXT WEEK.
&&
.DISCUSSION...
CONVECTION CONTINUES FROM GILA TO YAVAPAI COUNTIES THIS
MORNING...SENDING OUTFLOWS INTO THE VALLEY AND SPAWNING ISOLATED
SHOWERS AND THUNDERSTORMS AS FAR WEST AS THE ESTRELLA MOUNTAINS AS
OF 2 AM. NOT MUCH IN THE WAY OF SEVERE WEATHER PER SE...BUT THERE
HAVE BEEN REPORTS OF NEARLY 2 INCHES OF RAIN SINCE APPROX 10PM LAST
EVENING WITH THE STRONGEST STORMS. ONLY THE HRRR MODEL HAS ANY SENSE
OF WHATS GOING ON AT THE MOMENT...SHOWING STORMS DIMINISHING AROUND
12Z. WITH THIS IN MIND...I WILL MAINTAIN A CHANCE OF SHOWERS AND
THUNDERSTORMS IN THE FORECAST THROUGH THE PRE-DAWN HOURS EAST OF
PHOENIX.
ONGOING CONVECTION AND NUMEROUS OUTFLOWS ARE WREAKING HAVOC ON OUR
PRECIP CHANCES FOR LATER TODAY. ATMOSPHERE REMAINS PRIMED FOR
CONVECTION AT THE MOMENT PROVIDED THERE IS ENOUGH FORCING IN
PLACE...BUT MOISTURE WILL BEGIN ERODING FROM THE WEST LATER THIS
AFTERNOON AND CONSEQUENTLY...INSTABILITY IS EXPECTED TO DIMINISH
RAPIDLY BY 00Z. ON TOP OF THAT...THE ATMOSPHERE WILL ALMOST
CERTAINLY BE WORKED OVER ACROSS THE HIGHER TERRAIN. WHILE IT APPEARS
THERE IS STILL A CHANCE OF STORMS LATER TODAY...I HAVE REDUCED POPS
GIVEN THE ABOVE CONCERNS. AREAL COVERAGE AND EXTENT OF STORMS WOULD
HAVE BEEN LESSER TODAY ANYWAY GIVEN ERODING MOISTURE BUT I THINK
THIS OVERNIGHT COMPLEX WILL LESSEN COVERAGE EVEN MORE.
A BIT OF A BREAK FROM THE MONSOON LOOKS LIKELY FROM WEDNESDAY
THROUGH SATURDAY AS MOISTURE DECREASES AND INSTABILITY DROPS TO
NOTHING. PRECIP CHANCES WERE CHANGED ONLY SLIGHTLY EACH
DAY...GENERALLY CLIMO MINUS 10 OR 15 PERCENT. SOME SUGGESTION OF AN
EASTERLY WAVE/INVERTED TROUGH MOVING THROUGH THE AREA LATE THIS
WEEKEND INTO EARLY NEXT WEEK. WITH THIS IN MIND...I STARTED BRINGING
POPS BACK INTO THE DESERTS ON SUNDAY AND MONDAY ALTHOUGH FIGURING
OUT THE EXACT TIMING THIS FAR IN ADVANCE IS TRICKY AT BEST.
&&
.AVIATION...
SOUTH CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
SHOWER AND THUNDERSTORM ACTIVITY OVER HIGHER TERRAIN NORTH AND EAST
OF THE PHOENIX AREA IS FINALLY TRENDING DOWN EARLY THIS MORNING.
SOME ISOLATED WEAK SHOWERS MAY STILL POP UP OVER THE METRO AREA
BEFORE 16Z BUT TOO LOW A PROBABILITY TO INCLUDE IN THE TAFS.
ANTICIPATE THUNDERSTORM ACTIVITY TO FLIRT WITH THE METRO AREA ONCE
AGAIN LATER TODAY AND TONIGHT WITH OUTFLOW WINDS CAUSING ERRATIC
WIND SHIFTS. NO WIDESPREAD STORM DEVELOPMENT IS ANTICIPATED OVER THE
METRO BUT STORMS CAN BE EXPECTED AFTER 23Z NEAR THE FOOTHILLS.
CONFIDENCE IN STORM OCCURRENCE AT THE TAF SITES NOT HIGH ENOUGH AT
THIS TIME TO INSERT TEMPO/PROB TSRA IN THE TAFS. OTHERWISE...WINDS
WILL BE LIGHT AND FAVOR TYPICAL DIURNAL PATTERNS.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
VERY ISOLATED SHOWERS OVER SOUTHEAST CALIFORNIA ARE ANTICIPATED TO
DISSIPATE BY 15Z AND MAY DRIFT OVER KBLH. OTHERWISE...STORM ACTIVITY
LATER TODAY IS EXPECTED TO BE EAST OF THE LOWER COLORADO RIVER
VALLEY. ANTICIPATE WINDS TO FOLLOW A SIMILAR PATTERN TO THE PREVIOUS
24 HOURS WITH AFTERNOON GUSTS A BIT STRONGER AT KBLH THAN YESTERDAY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
ATMOSPHERIC MOISTURE AND ASSOCIATED THUNDERSTORM ACTIVITY IS
EXPECTED TO BEGIN TRENDING UPWARD LATE THIS WEEK INTO EARLY NEXT
WEEK AS A WEATHER DISTURBANCE TRACKS WESTWARD ACROSS FAR NORTHERN
MEXICO. ACCORDINGLY...HUMIDITIES WILL TREND SLOWLY UPWARD FROM EAST
TO WEST. APART FROM THUNDERSTORMS...WINDS ARE EXPECTED TO FOLLOW
FAMILIAR WARM SEASON DIURNAL PATTERNS. THUNDERSTORM CHANCES ARE
EXPECTED TO REMAIN PRIMARILY EAST OF THE LOWER COLORADO RIVER
VALLEY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...LEINS
AVIATION...AJ
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
200 AM MST TUE JUL 24 2012
.SYNOPSIS...
THUNDERSTORM CHANCES WILL BEGIN TO DECREASE OVER THE NEXT FEW DAYS
AS DRIER AIR SLOWLY WORKS IN FROM THE WEST. AFTER TODAY...STORM
CHANCES WILL MAINLY BE CONFINED TO THE HIGHER TERRAIN AREAS EAST OF
PHOENIX. DRIER AND SLIGHTLY WARMER WEATHER WILL SETTLE ACROSS THE
REGION FOR LATE THIS WEEK INTO THE WEEKEND...BEFORE A MORE ACTIVE
MONSOON PATTERN IS POSSIBLE BY THE EARLY PART OF NEXT WEEK.
&&
.DISCUSSION...
CONVECTION CONTINUES FROM GILA TO YAVAPAI COUNTIES THIS
MORNING...SENDING OUTFLOWS INTO THE VALLEY AND SPAWNING ISOLATED
SHOWERS AND THUNDERSTORMS AS FAR WEST AS THE ESTRELLA MOUNTAINS AS
OF 2 AM. NOT MUCH IN THE WAY OF SEVERE WEATHER PER SE...BUT THERE
HAVE BEEN REPORTS OF NEARLY 2 INCHES OF RAIN SINCE APPROX 10PM LAST
EVENING WITH THE STRONGEST STORMS. ONLY THE HRRR MODEL HAS ANY SENSE
OF WHATS GOING ON AT THE MOMENT...SHOWING STORMS DIMINISHING AROUND
12Z. WITH THIS IN MIND...I WILL MAINTAIN A CHANCE OF SHOWERS AND
THUNDERSTORMS IN THE FORECAST THROUGH THE PRE-DAWN HOURS EAST OF
PHOENIX.
ONGOING CONVECTION AND NUMEROUS OUTFLOWS ARE WREAKING HAVOC ON OUR
PRECIP CHANCES FOR LATER TODAY. ATMOSPHERE REMAINS PRIMED FOR
CONVECTION AT THE MOMENT PROVIDED THERE IS ENOUGH FORCING IN
PLACE...BUT MOISTURE WILL BEGIN ERODING FROM THE WEST LATER THIS
AFTERNOON AND CONSEQUENTLY...INSTABILITY IS EXPECTED TO DIMINISH
RAPIDLY BY 00Z. ON TOP OF THAT...THE ATMOSPHERE WILL ALMOST
CERTAINLY BE WORKED OVER ACROSS THE HIGHER TERRAIN. WHILE IT APPEARS
THERE IS STILL A CHANCE OF STORMS LATER TODAY...I HAVE REDUCED POPS
GIVEN THE ABOVE CONCERNS. AREAL COVERAGE AND EXTENT OF STORMS WOULD
HAVE BEEN LESSER TODAY ANYWAY GIVEN ERODING MOISTURE BUT I THINK
THIS OVERNIGHT COMPLEX WILL LESSEN COVERAGE EVEN MORE.
A BIT OF A BREAK FROM THE MONSOON LOOKS LIKELY FROM WEDNESDAY
THROUGH SATURDAY AS MOISTURE DECREASES AND INSTABILITY DROPS TO
NOTHING. PRECIP CHANCES WERE CHANGED ONLY SLIGHTLY EACH
DAY...GENERALLY CLIMO MINUS 10 OR 15 PERCENT. SOME SUGGESTION OF AN
EASTERLY WAVE/INVERTED TROUGH MOVING THROUGH THE AREA LATE THIS
WEEKEND INTO EARLY NEXT WEEK. WITH THIS IN MIND...I STARTED BRINGING
POPS BACK INTO THE DESERTS ON SUNDAY AND MONDAY ALTHOUGH FIGURING
OUT THE EXACT TIMING THIS FAR IN ADVANCE IS TRICKY AT BEST.
&&
.AVIATION...
SOUTH CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
MAINLY EAST TO SOUTHEAST WIND FOR TERMINALS TONIGHT AND TOMORROW
MORNING. SLIGHT CHANCE FOR A THUNDERSTORM THIS EVENING UNTIL AROUND
06Z...BUT NOT ENOUGH CONFIDENCE IN TIMING OR LOCATION OF STORM
DEVELOPMENT TO INCLUDE VCTS IN THE TAFS.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
WINDS MOSTLY FROM THE SOUTH ACROSS THE REGION. NO STORMS EXPECTED
TONIGHT.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
EXPECT THUNDERSTORM ACTIVITY TO BEGIN PICKING UP AGAIN BEGINNING
FRIDAY AND RUNNING THROUGH THE WEEKEND. HUMIDITIES WILL ALSO BE
INCREASING THROUGH THE WEEKEND. MOST ACTIVITY SHOULD BE TO THE EAST
OF THE COLORADO RIVER.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...LEINS
AVIATION...DG
FIRE WEATHER...WATERS
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
1017 AM PDT TUE JUL 24 2012
.SHORT TERM DISCUSSION...
THE UPPER LOW WHICH BROUGHT CONVECTION OVER THE PAST FEW DAYS IS
WEAKENING AND SHIFTING EAST OF THE AREA. WATER VAPOR IMAGERY
SHOWS DRY SOUTHWEST FLOW SETTING UP OVER REGION. SOME MOISTURE
LINGERS OVER THE FAR NORTHERN SIERRA AND THE BURNEY BASIN BUT EVEN
THIS SHOULD BE EXITING LATER TODAY. A PERSISTENT UPPER LEVEL
PATTERN OF COASTAL TROUGHING AND INLAND RIDGING WILL SET UP AND
CONTINUE FOR MUCH OF THE FORECAST PERIOD.
VISIBLE SATELLITE SHOWS A CONSIDERABLE MARINE LAYER ALONG THE
COAST. THE FORT ORD PROFILER HAS THE MARINE LAYER ABOUT 2200 FEET
THICK. STRATUS THIS MORNING SPREAD ONLY INTO THE DELTA WEST OF
FAIRFIELD. WITHOUT A SIGNIFICANT SHORTWAVE TROUGH INCURSIONS OF
MARINE AIR SHOULD BE RELATIVELY LIMITED FOR THE REST OF THE WORK
WEEK. THE DELTA BREEZE BROUGHT COOL AIR INTO THE DELTA/SOUTHERN
SACRAMENTO VALLEY THIS MORNING. THIS IS EXPECTED TO STRENGTHEN
AGAIN OVERNIGHT KEEPING ADJACENT AREAS FAIRLY COOL.
THE MAIN ISSUE FOR TODAY IS THE POTENTIAL FOR AN ISOLATED SHOWER
OR THUNDERSTORM OVER THE BURNEY BASING AREA. THE WRF ARW IS SHOWING
SOME CONVECTION DEVELOPING THERE IN THE EARLY AFTERNOON BUT THIS
IS QUITE LIKELY OVERDONE AS THE TROUGH IS MOVING OUT FAIRLY
QUICKLY. THE LATEST HRRR AND NAM12 MODELS ARE SHOWING THE AIRMASS
DRYING AND BECOMING STABLE OVER THE FORECAST AREA. WILL CONSIDER
PULLING OUT THE ISOLATED SHOWERS/THUNDERSTORMS BUT FOR THE MOMENT
WILL KEEP THEM IN THE FORECAST. OTHERWISE...THE FORECAST LOOKS
DRY FOR TODAY.
HIGHS TODAY WILL BE A COUPLE DEGREES BELOW NORMAL. TEMPERATURES
SHOULD TREND DOWN A LITTLE MORE THROUGH FRIDAY. WARMING TO NEAR
NORMAL IS EXPECTED FOR THE WEEKEND AS RIDGING BUILDS. HIGHS MAY
REACH A LITTLE ABOVE NORMAL EARLY NEXT WEEK. EK
.EXTENDED DISCUSSION (SATURDAY THROUGH TUESDAY)
THE EXTENDED PERIOD WILL FEATURE SOUTHWEST FLOW ALOFT OVER NORCAL
WITH WEAK TROUGHING OFF THE WEST COAST AND A RIDGE OVER THE
INTERMOUNTAIN WEST. EXTENDED MODELS ATTEMPT TO ROTATE WEAK
SHORTWAVES AT TIMES THROUGH THE FLOW AND INTO NORCAL...ALTHOUGH
THEY CURRENTLY HAVE NO CONSENSUS ON TIMING. TEMPERATURES LOOK
SEASONAL WITH THE POTENTIAL FOR DAILY DELTA BREEZE COOLING GIVEN
THE TROUGH POSITION AND PERHAPS SOME OVERNIGHT LOW CLOUDS
EXTENDING INTO THE DELTA REGION. DRY WEATHER IS EXPECTED THROUGH
THE PERIOD AS THE MONSOONAL FLOW REMAINS WELL EASTWARD OF OUR AREA.
&&
.AVIATION...
VFR CONDS WILL CONTINUE NEXT 24 HOURS. ONSHORE FLOW PERSISTS
WITH STRONGEST WINDS IN THE DELTA REGION AT 15-25 KTS FROM THE
WEST. VALLEY WINDS WILL START OFF LIGHT THIS MORNING...THEN
STRENGTHEN LATER THIS AFTN/EVENING TO SW 10-15 KTS. WINDS ALOFT
WILL GENERALLY BE LIGHT FROM THE SW TODAY AND WEDNESDAY. -DVC
&&
.STO WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NEW YORK NY
948 PM EDT WED JUL 25 2012
.SYNOPSIS...
HIGH PRESSURE BUILDS OFFSHORE THIS EVENING AS A POTENT STORM
SYSTEM TRACKS EAST ACROSS THE GREAT LAKES...PASSING TO THE NORTH
ON THURSDAY. A WARM FRONT WILL PASS IN THE MORNING...FOLLOWED BY
A TROUGH OF LOW PRESSURE THURSDAY EVENING. A FRONTAL SYSTEM WILL
SLOWLY PUSH ACROSS AND THEN EAST OF THE REGION FRIDAY THROUGH
SATURDAY NIGHT. WEAK HIGH PRESSURE THEN BUILDS IN SUNDAY INTO THE
BEGINNING OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
GENERALLY DRY CONDS ON TAP FOR THE OVERNIGHT PERIOD AS HIGH PRES
OVERHEAD MOVES OFFSHORE AFTER MIDNIGHT.
STORM SYSTEM DEVELOPING OVER THE OH VALLEY...AND SHORT TERM MODELS
INDICATING EITHER THE SYSTEM OR REMNANTS OF IT WILL APPROACH
WESTERN PORTIONS OF THE FORECAST AREA TOWARDS THE END OF THE
OVERNIGHT PERIOD. LATEST HRRR MODEL HAS ONE WAVE IMPACTING THE
AREA AFTER MIDNIGHT...THEN ANOTHER WAVE APPROACHING FOR AFTER
SUNRISE THURSDAY MORNING. 18Z NAM HAS THE COMPLEX ENTERING WESTERN
PORTIONS OF THE CWA BY 12Z THURSDAY. WILL CARRY SLIGHT CHANCE POPS
FOR ORANGE COUNTY LATE...AND WILL HOLD OFF ON REST OF POPS UNTIL
THE START OF THE SECOND PERIOD.
OVERNIGHT LOWS STILL EXPECTED TO BE NEAR OR JUST ABOVE SEASONABLE
LEVELS. USED A MET/MAV MOS BLEND.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
WITH EITHER REMNANTS OF OR THE MCS ITSELF APPROACHING THURSDAY
MORNING...WILL GO AHEAD AND INCREASE POPS TO CHANCE STARTING
BETWEEN 10-12Z OVER WESTERN ZONES...THEN WILL SPREAD THOSE POPS
EAST THROUGH 15-17Z. THIS ACTIVITY WILL BE AHEAD OF A WARM FRONT
THAT MOVES NORTH THROUGH THE REGION IN THE MORNING...THEN THE CWA
BECOMES WARM SECTORED IN THE AFTERNOON. WITH LLJ APPROACHING IN
THE MORNING...WILL GO AHEAD AND MENTION GUSTY WINDS IN THE
FORECAST FOR THURSDAY MORNING.
OTHERWISE...AN INITIAL CAP OVER THE AREA IN THE EARLY AFT SHOULD
ERODE WITH A HIGHLY UNSTABLE AIR MASS IN PLACE. MU CAPES OF 2000
TO 3000 J/KG AND 35 TO 40 KT MID LEVEL WINDS WILL SET UP A
FAVORABLE ENVIRONMENT FOR SEVERE WX DURING THE LATE AFTERNOON AND
FIRST HALF OF THE EVENING. CONVERGENCE ALONG AND AHEAD OF THE PRE-
FRONTAL TROF WILL PROVIDE THE LOW-LEVEL FORCING WITH WEAK MID
LEVEL HEIGHT FALLS. THIS FAVORS THE DEVELOPMENT OF A SCATTERED TO
NUMEROUS THUNDERSTORMS. A UNIDIRECTIONAL WIND PROFILE SUPPORTS
MULTIPLE CLUSTERS AND BOWING SEGMENTS WITH THE PRIMARY THREAT
BEING DAMAGING WINDS. SOME WEAKENING OF THE CONVECTION IS EXPECTED
AS IT MOVES OUT ACROSS EASTERN LI AND SE CT. CONVECTION SHOULD
DIMINISH BY MIDNIGHT FROM WEST TO EAST.
AN HWO HAS BEEN UPDATED TO ADDRESS THE SEVERE WEATHER POTENTIAL.
SPC HAS PLACED MOST OF THE AREA UNDER A MODERATE RISK FOR THU AFT
AND EVE. ENHANCED WORDING ADDED TO THE FORECAST TO REFLECT THE
POTENTIAL THESE STORMS WILL HAVE.
PRIOR TO THE ONSET OF THE LATE DAY CONVECTION...A SURGE OF WARM
ALOFT WITH 85H TEMP NEAR 22C WILL ALLOW DAYTIME HIGHS AWAY FROM
THE COAST TO REACH INTO THE LOWER 90S...WITH THE LOW TO MID 80S
ALONG THE COAST. HEAT INDEX VALUES FOR NYC LOOK TO BE JUST BELOW
95.
A WARM...MUGGY NIGHT WILL BE ON TAP THU NIGHT WITH LOW IN THE
LOWER TO MID 70S WITH DEW POINTS AROUND 70. FRONTAL BOUNDARY LOOKS
TO REMAIN JUST NORTH OF THE AREA.
THERE IS A MODERATE RISK OF RIP CURRENTS THURSDAY
MORNING...BECOMING HIGH THURSDAY AFTERNOON THROUGH THURSDAY
EVENING AS WINDS INCREASE TO 15 TO 25 MPH AND SURF BUILDS TO 3 TO
5 FT.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
ACTIVE PERIOD TO START THE LONG TERM WITH A GRADUALLY AMPLIFYING
TROUGH WORKING FROM THE GREAT LAKES TO THE EAST COAST THROUGH
SATURDAY NIGHT. MEANWHILE AT THE SURFACE...A SLOW MOVING COLD
FRONT WITH MULTIPLE WEAK WAVES OF LOW PRESSURE WILL GRADUALLY
MOVES ACROSS AND THEN EAST OF THE REGION.
POTENTIAL FOR SCATTERED STRONG TO SEVERE CONVECTION EXISTS ON FRIDAY
AFTERNOON/EARLY EVENING AS THE COLD FRONT PUSHES THE VERY WARM AND
HUMID AIR MASS OFFSHORE...WITH AT LEAST MODERATE CAPE AND SHEAR. WITH
UNCERTAINTY ON CONVECTIVE DEBRIS...HAVE STAYED CLOSE TO MAV/MET
TEMPS. GENERALLY UPPER 80S/LOWER 90S AREA-WIDE...AND WITH DEWPOINT
POOLING AT LEAST IN THE LOWER 70S...HEAT INDICES IN THE MID TO UPPER
90S FOR MUSH OF THE REGION. MARGINAL HEAT ADVISORY POTENTIAL FOR
NYC/NJ METRO.
THEN SOME UNCERTAINTY FOR FRIDAY NIGHT THROUGH SATURDAY NIGHT IN HOW
FAR OFFSHORE THE COLD FRONT MOVES OFFSHORE AND TIMING OF WEAK WAVES
AND ASSOCIATED AREAS OF PRECIP ALONG THE FRONT. BUT OVERALL WITH
TROUGH AXIS APPROACHING AND FAVORABLE CAPE/SHEAR
ENVIRONMENT...POTENTIAL EXISTS FOR STRONG CONVECTION ACROSS AT LEAST
WESTERN SECTIONS OF THE REGION SAT AFTERNOON/EARLY EVENING.
MODELS IN DECENT AGREEMENT WITH TROUGH AXIS SLIDING EAST SATURDAY
NIGHT...BUT LIKELY GIVING WAY TO MEAN EAST COAST TROUGHING THROUGH
MIDWEEK. AT THE SURFACE BROAD BUT WEAK HIGH PRESSURE BUILDS IN FOR
SUN INTO MON AND THEN PUSHES OFFSHORE ON TUES. THE RESULT WILL NEAR
SEASONABLE CONDITIONS WITH WIDELY SCATTERED DIURNAL CONVECTION SUN
AND MON AFTERNOON.
INCREASING UNCERTAINTY IN DETAILS FOR TUE AND WED...BUT RETURN FLOW
SHOULD ALLOW FOR AN INCREASE IN HUMIDITY LEVELS AND POSSIBLY
INCREASED DIURNAL SHOWER/TSTM COVERAGE.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
HIGH PRESSURE WILL PASS TO THE SOUTH TONIGHT. A WARM FRONT WILL
APPROACH THU MORNING...AND PASS THROUGH LATE THU MORNING OR EARLY
THU AFTERNOON. A COLD FRONT WILL APPROACH TOWARD THU EVENING.
TSTMS DEVELOPING AHEAD OF THE WARM FRONT AS 0F 00Z OVER LOWER
MICHIGAN SHOULD EXPAND AND HEAD E-SE TOWARD THE AREA.
CURRENT THINKING IS THAT THESE STORMS SHOULD REACH KSWF BY 12Z-
13Z...NYC METRO BY 13Z-14Z...KBDR/KISP BY 14Z-15Z...AND KGON BY
15Z-16Z. CONFIDENCE AT LEAST HIGH ENOUGH TO ADDRESS VIA PROB30
GROUP AND TO MENTION MVFR VSBY AT KSWF/KHPN/KBDR.
WHILE WIDESPREAD TSTM IMPACTS FROM A LINE OF STRONG TO SEVER
TSTMS SHOULD BEGIN TOWARD THE VERY END OF THE 00Z TAF PERIOD...
SOME DISCRETE TSTMS ARE POSSIBLE BEFORE THAT BEGINNING ABOUT 20Z-
21Z. UNTIL THEN...WIND IMPACTS WILL BE THE GREATER CONCERN...AS SW
WINDS INCREASE QUICKLY AFTER ABOUT 12Z-13Z...WITH SPEEDS AROUND
15 KT WITH GUSTS 20-25 KT IF NOT BOTH A LITTLE HIGHER IN NYC
METRO.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: HIGH CONFIDENCE WINDS...MEDIUM CONFIDENCE AM
TSTM IMPACTS.
KJFK FCSTER COMMENTS: HIGH CONFIDENCE WINDS...MEDIUM CONFIDENCE AM
TSTM IMPACTS.
KLGA FCSTER COMMENTS: HIGH CONFIDENCE WINDS...MEDIUM CONFIDENCE AM
TSTM IMPACTS.
KTEB FCSTER COMMENTS: HIGH CONFIDENCE WINDS...MEDIUM CONFIDENCE AM
TSTM IMPACTS.
KHPN FCSTER COMMENTS: HIGH CONFIDENCE WINDS...MEDIUM CONFIDENCE AM
TSTM IMPACTS.
KISP FCSTER COMMENTS: HIGH CONFIDENCE WINDS...LOW CONFIDENCE AM
TSTM IMPACTS.
OUTLOOK FOR 00Z FRI THROUGH MONDAY...
.THU EVENING...LINE OF SEVERE TSTMS WITH STRONG WINDS AND IFR
CONDS EXPECTED.
.LATER THU NIGHT THROUGH MON......OCNL IFR CONDITIONS ARE POSSIBLE
WITH LOW CLOUDS AND/OR SHOWERS/TSTMS.
&&
.MARINE...
TRANQUIL CONDS ON TAP FOR TONIGHT. TSTMS ARE POSSIBLE THURSDAY
MORNING FROM 10-15Z AS STORM SYSTEM APPROACHES FROM THE WEST.
SCA REMAINS UP FOR ALL WATERS FOR A STRENGTHENING SW FLOW THU AND
THU EVE AHEAD OF POTENT STORM SYSTEM WHICH PASSES TO THE NORTH THU
EVE. GUSTS UP TO 30 POSSIBLE ALONG WITH A LINE OF SEVERE
THUNDERSTORMS DURING THE LATE AFT/EVE HOURS.
SW FLOW EXPECTED TO GRADUALLY WEAKEN ON FRIDAY...BUT MARGINAL SCA
SEAS WILL LIKELY LINGER UNTIL THE COLD FRONT PASSES LATE
FRIDAY/FRIDAY EVENING.
ONCE OCEAN SEAS SUBSIDE...LATE FRIDAY/FRI NIGHT...SUB SCA CONDITIONS
EXPECTED IN A WEAK PRESSURE REGIME THROUGH EARLY NEXT WEEK.
&&
.HYDROLOGY...
NO SIGNIFICANT RAINFALL IS EXPECTED THROUGH TONIGHT.
PRECIPITABLE WATERS ARE FORECAST TO INCREASE TO AROUND 2 INCHES
BY THURSDAY AFTERNOON. AS THE RESULT LOCALLY HEAVY RAINFALL IS
POSSIBLE WITH ANY STRONGER CONVECTION...ESPECIALLY THURSDAY EVENING.
WITH A FORECAST STORM MOTION OF AROUND 20 KT...MINOR URBAN/POOR
DRAINAGE FLOODING IS THE MOST LIKELY THREAT. LOCALIZED FLASH
FLOODING CANNOT BE RULED OUT THOUGH...ESPECIALLY IF TRAINING
OCCURS. FOR NOW FORECASTING BASIN AVERAGE QPF AMOUNTS OF AROUND
1/4 TO 1/2 AN INCH WITH LOCALIZED AMOUNTS OF 1-2+ INCHES POSSIBLE.
MAIN THREAT APPEARS TO BE FOR LOCALLY HEAVY RAINFALL FROM DIURNAL
CONVECTION FRIDAY AND SATURDAY AFTERNOON.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 AM TO 11 PM EDT THURSDAY FOR
ANZ330-335-338-340-345.
SMALL CRAFT ADVISORY FROM 11 AM THURSDAY TO 6 AM EDT FRIDAY
FOR ANZ350-353-355.
&&
$$
SYNOPSIS...NV/DW
NEAR TERM...MPS/DW
SHORT TERM...MPS/DW
LONG TERM...NV
AVIATION...GOODMAN
MARINE...NV/DW
HYDROLOGY...MALOIT/MET
AREA FORECAST DISCUSSION
NWS TAUNTON MA
703 PM EDT WED JUL 25 2012
.SYNOPSIS...
A FRONTAL BOUNDARY WILL STALL ACROSS THE REGION THURSDAY INTO THE
WEEKEND...BRINGING ROUNDS OF SCATTERED SHOWERS AND THUNDERSTORMS.
CONDITIONS LOOK TO IMPROVE EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 4 AM THURSDAY MORNING/...
7 PM UPDATE...
HIGH CLOUD SHIELD FROM ADVANCING MCS IS WORKING ITS WAY INTO
SOUTHERN NEW ENGLAND THIS EVENING. WINDS HAVE DIMINISHED ACROSS
MOST OF AREA AND COMBINATION OF INCREASING CLOUDS AND DRY AIRMASS
WILL PREVENT FOG FORMATION INLAND TONIGHT.
18Z MODELS STILL UNCERTAIN AS TO WHERE MCS WILL TRACK OVERNIGHT.
GFS KEEPS IT N ACROSS VT/NH WHILE NAM SHOWS MORE OF A SOUTHERN
TRACK INTO MORE OF CT/RI/MA. LATEST 3KM HRRR SEEMS TO MIRROR NAM
AND MAY EVEN BE FARTHER S. SHOULD BE APPROACHING OUR AREA TOWARD
4 AM THU.
&&
.SHORT TERM /4 AM THURSDAY MORNING THROUGH FRIDAY/...
EARLY MORNING THURSDAY...
MODELS CONTINUE TO HINT AT A COMPLEX OF STORMS DEVELOPING ACROSS
THE EASTERN GREAT LAKES. THESE STORMS WILL RIDE ALONG AN
INSTABILITY AXIS...WHICH WILL DRAPE ACROSS CENTRAL NY STATE AND
NORTH OF THE PIKE. EXPECT THESE STORMS TO LAST INTO THE LATE
MORNING HOURS ON THURSDAY AS 850 MB JET COMBINED WITH A LOT OF MOISTURE
WILL HELP AID IN STORMS RETAINING THEMSELVES. BEST REGION WILL BE
OUT WEST ACROSS THE NORTH PIKE AND INTO NH. HOWEVER AS THE STORMS
APPROACH THE EAST COAST THEY SHOULD BEGIN TO DISSIPATE AS
ATMOSPHERE INSTABILITY COMBINED WITH THE MARINE LAYER IS QUITE
UNFAVORABLE. THERE IS STILL SOME UNCERTAINTY TO THIS SCENARIO...AS
MODELS HAVE BEEN SLOWLY SLIDING THESE STORMS FARTHER NORTH WITH
EACH RUN.
THURSDAY AFTERNOON...
ONCE THE STORMS DIE DOWN BY LATE MORNING HOURS BELIEVE THAT THE
REGION WILL HAVE A HARD TIME RECOVERING AS THERE WILL BE CLOUD
DEBRIS. WITH THIS BEING SAID...SINCE MODELS KEEP PUSHING THE SYSTEM
NORTHWARD...REGIONS DOWN SOUTH INCLUDING CT/RI AND WESTERN MASS
WILL SIT IN A HIGHLY UNSTABLE AIRMASS. MLCAPES ARE BETWEEN
1500-2500 J/KG AND 0-6KM BULK SHEAR RANGES FROM 40-50 KTS...GOOD
INSTABILITY AND DEEP LAYER SHEAR WILL ALLOW FOR STRONG TO SEVERE
STORMS TO DEVELOP. AS WARM FRONT LIFTS NORTHWARD IN THE LATE
AFTERNOON EXPECT STORMS TO DEVELOP...AROUND 3-5PM. THESE STORMS
MAY BE ISOLATED IN NATURE AT FIRST PRODUCING LARGE HAIL AND
DAMAGING WINDS...EVEN AN ISOLATED TORNADO CAN NOT BE RULED OUT.
AGAIN THE BEST REGIONS WILL BE ACROSS CT/WESTERN RI AND WESTERN
MASS...SOUTH OF THE PIKE...WHERE THE BEST CLEARING WILL OCCUR. STORMS
WILL CONTINUE THROUGH THE LATE AFTERNOON AND INTO THE EVENING
HOURS. AS THE DAY GOES BY EXPECT A FEW BOWING SEGMENTS AS WELL
WITH DAMAGING WINDS BEING THE MAIN THREAT. LAST THREAT IS FLASH
FLOODING AS PWAT VALUES DO REACH ABOVE 2 INCHES. DUE TO NUMEROUS
NATURE...CANNOT RULE OUT TRAINING ALONG STORMS.
OVERNIGHT THURSDAY...
CONVECTION WILL CONTINUE INTO THE EVENING AND OVERNIGHT HOURS AS
LLJ INCREASES ACROSS THE AREA COMBINED WITH THE HIGHLY UNSTABLE
ENVIRONMENT. EXPECT THE THREAT WILL TRANSITION TO STRONG DAMAGING
WINDS DURING THE OVERNIGHT HOURS. STILL UNCERTAIN ON EXACT
LOCATION BUT BELIEVE STORMS WILL BE WIDE SPREAD AND QUITE
NUMEROUS ACROSS THE REGION...ESP SOUTH OF THE PIKE. FLASH FLOODING
THREAT WILL REMAIN INTO THE OVERNIGHT HOURS AS WELL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
HIGHLIGHTS...
*THUNDERSTORMS LIKELY AGAIN FRI...ESPECIALLY SOUTH OF THE MASSPIKE.
*FAIR WEATHER IS EXPECTED SUNDAY AND MONDAY.
*UNSETTLED WEATHER RETURNS TUESDAY AND WEDNESDAY.
DETAILS...
FRIDAY...AN EAST-WEST ORIENTED FRONTAL BOUNDARY WILL BE DRAPED
ACROSS THE REGION. THERE WILL BE AMPLE MOISTURE THROUGH THE COLUMN...
WHICH WILL LEAD TO CONSIDERABLE CLOUDINESS. IF ENOUGH BREAKS IN THE
CLOUDINESS CAN DEVELOP TO THE SOUTH OF THE BOUNDARY IN THE WARM
SECTOR...THEN STRONG THUNDERSTORMS WOULD BE POSSIBLE AGAIN. MODELS
ARE HINTING AT THIS...WITH THE BEST INSTABILITY FOCUSED TO THE
SOUTH OF THE MASSPIKE /CAPES OVER 1500 JOULES/. IN ADDITION...
BULK SHEAR VALUES /IN EXCESS OF 40 KNOTS/ ARE ALSO CO-LOCATED
WITH THE BEST INSTABILITY. SO...THE POTENTIAL FOR SEVERE WEATHER
/ESPECIALLY SOUTH OF THE MASSPIKE/ IS THERE. IN ADDITION...
THERE IS ALSO THE POTENTIAL OF FLASH FLOODING WITH ANY TRAINING
STORMS /GIVEN THE ANOMALOUSLY HIGH PRECIPITABLE WATER VALUES/.
EXPECT HIGH TEMPS IN THE MIDDLE 70S TO MIDDLE 80S WITH THE WARMEST
READINGS TO THE SOUTH OF THE MASSPIKE.
SATURDAY...WITH THE MID-LEVEL TROUGH STILL TO THE WEST AND AMPLE
MOISTURE...EXPECT CONSIDERABLE CLOUDINESS. SCATTERED SHOWERS ARE
ALSO LIKELY. HIGH TEMPERATURES WILL BE IN THE 70S TO AROUND 80
ACROSS THE REGION.
SUNDAY...THE MID-LEVEL TROUGH AXIS MOVES OFF THE COAST...BRINGING
A CLEARING TREND. THE ECMWF AND GFS DIFFER WITH REGARD TO THE TIMING
OF THE CLEARING /GFS IS QUICKER THAN ECMWF/. AT THIS TIME...HAVE
BROUGHT A CLEARING TREND FROM NORTHWEST TO SOUTHEAST ACROSS THE
REGION FROM LATE MORNING INTO EARLY AFTERNOON. WITH CLEARING
SKIES...TEMPERATURES SHOULD REBOUND...RANGING FROM THE UPPER 70S
TO MIDDLE 80S.
MONDAY TO WEDNESDAY...A SHORT-WAVE DIVING SOUTHEASTWARD THROUGH THE
GREAT LAKES WILL RE-ENERGIZE THE NORTHEAST US TROUGH. MONDAY LOOKS
LIKE A FAIR WEATHER DAY. BUT AS THE MID-LEVEL TROUGH SHARPENS...
THE FLOW WILL BECOME MORE SOUTHWEST...AND SOME CLOUDINESS /PERHAPS
A SHOWER/ WILL STREAM INTO THE REGION LATE IN THE DAY OR MONDAY
NIGHT. ON TUESDAY..CLOUDS WILL CONTINUE TO INCREASE WITH A CHANCE
OF SHOWERS. FOR WEDNESDAY...THE ECMWF/GFS DIFFER ON PRECIPITATION
CHANCES /ECMWF IS DRY WHILE THE GFS GENERATES QPF/. HAVE CHANCE
POPS FOR NOW. EXPECT HIGH TEMPERATURES IN THE MIDDLE 70S TO MIDDLE
80S DURING THIS PERIOD.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
OVERVIEW...HIGH CONFIDENCE. SHOWERS/POSSIBLE TSTMS WILL REACH AREA
BEFORE DAYBREAK WITH LOCAL MVFR/IFR BUT NOT ENOUGH CONFIDENCE ON
LOCATION TO INCLUDE IN TAFS. BETTER CHANCE OF SHOWERS/TSTMS LATER
THU AFTERNOON AND NIGHT WITH MORE WIDESPREAD MVFR/IFR EXPECTED.
KBOS TAF...HIGH CONFIDENCE. POSSIBLE MVFR CIGS AROUND DAYBREAK.
MAIN WINDOW FOR TSTMS IS AFTER 00Z FRI.
KBDL TAF...HIGH CONFIDENCE. POSSIBLE MVFR CIGS BEFORE DAYBREAK.
MAIN WINDOW FOR TSTMS IS 21Z THU TO 00Z FRI.
OUTLOOK...FRIDAY THROUGH MONDAY...
FRIDAY...HIGH CONFIDENCE...MVFR IN SCT TSRA.
SATURDAY...MODERATE CONFIDENCE...MVFR IN SCT SHRA.
SUNDAY AND MONDAY...MODERATE CONFIDENCE...VFR.
&&
.MARINE...
MODERATE TO HIGH CONFIDENCE THROUGH THURSDAY. LET SCA EXPIRE AS
WINDS AND SEAS DROP BELOW THRESHOLDS. SCA HEADLINES WILL LIKELY BE
NEEDED AGAIN ACROSS THE SOUTHERN WATERS LATE THU MORNING AND
AFTERNOON. THIS IS FOR SOUTHWEST WIND GUSTS UP TO 25 KNOTS AND
SEAS EXCEEDING 5 FEET ACROSS THE SOUTHERN WATERS AND SOUTHWEST
SOUNDS. A FEW THUNDERSTORMS MAY ALSO AFFECT THE WATERS THU AND THU
EVENING.
OUTLOOK...FRIDAY THROUGH MONDAY...
MODERATE CONFIDENCE.
WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SCA THRESHOLDS
THROUGH THE PERIOD. SCT THUNDERSTORMS ARE EXPECTED FRIDAY
WITH A COLD FRONT. THEN...MAINLY DRY WEATHER /PERHAPS A
SHOWER SATURDAY/ THROUGH MONDAY AS HIGH PRESSURE BUILDS
OVER THE WATERS.
&&
.HYDROLOGY...
HIGH DEWPOINTS ACROSS THE SOUTHERN HALF OF THE REGION COMBINED
WITH 2 INCHES OR GREATER PWATS...WILL LEAD TO STRONG DOWNPOURS
WITHIN ANY THUNDERSTORMS. URBAN AND SMALL STREAM FLOODING MAY
OCCUR HOWEVER MAIN CONCERN IS THE POTENTIAL FOR FLASH FLOODING
WITHIN URBAN AREAS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 AM THURSDAY TO 8 AM EDT FRIDAY
FOR ANZ235-237-255-256.
&&
$$
SYNOPSIS...DUNTEN
NEAR TERM...JWD
SHORT TERM...DUNTEN
LONG TERM...JWD/LF
AVIATION...DUNTEN/JWD/LF
MARINE...DUNTEN/JWD/LF
HYDROLOGY...DUNTEN
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1244 AM EDT TUE JUL 24 2012
.SYNOPSIS...
A STRONG COLD FRONT OVER THE GREAT LAKES WILL TRACK SOUTHEAST
INTO OUR AREA TODAY. THIS FRONT EVENTUALLY STALLS TO OUR SOUTH ON
WEDNESDAY AS HIGH PRESSURE BRIEFLY INFLUENCES OUR AREA. ON THURSDAY
INTO FRIDAY, A WARM FRONT WILL LIFT NORTHEAST THROUGH THE REGION,
FOLLOWED BY A COLD FRONT FROM THE WEST TRACKING ACROSS THE MID
ATLANTIC AROUND SATURDAY. A HIGH PRESSURE SYSTEM WILL THEN BUILD
INTO THE NORTHEAST ON SUNDAY AND MONDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE LINE OF CONVECTIVE LOOKING ELEMENTS APPROACHING THE DELAWARE
VALLEY HAS DIMINISHED...EVEN THOUGH THE AIRMASS IS STILL MARGINALLY
UNSTABLE. THE INSTABILITY APPEARS TO HAVE BECOME MORE ELEVATED...BASED
ON THE EXPANDING CLUTTER ON THE KDIX RADAR...AND THE PATCHY FOG
TRYING TO FORM HERE AT THE OFFICE (AND OTHER PLACES RAIN FELL).
THIS ACTIVITY WILL BE REMOVED FROM THE FORECAST WITH THE NEXT
UPDATE.
THE NEXT PROBLEM IS THE CONVECTION FORMING EAST OF LAKE ERIE...IN
THE POOL OF THE BEST AVAILABLE INSTABILITY. IT WOULD APPEAR THAT
MOST OF THE CONVECTIVE WOULD CONTINUE MOVING EAST IN THE WEST
NORTHWEST MID LEVEL FLOW...FOLLOWING THE BEST LOW TO MID LEVEL
THETA E. THE LATEST RUN OF THE HRRR KEEPS THE ACTIVITY OUT OF THE
AREA...AS DOES THE 0000 UTC NAM. THE CURRENT FORECAST CARRIES ONLY
A SLIGHT CHANCE FAR NORTH...AND THIS WILL BE RETAINED FOR NOW.
PATCHY FOG IS FORMING IN LOCATIONS WHERE IT RAINED...AND THE
MENTION OF PATCHY FOG WILL BE EXPANDED TO INCLUDE PORTIONS OF
CENTRAL NEW JERSEY AND THE LEHIGH VALLEY. NO SIGNIFICANT CHANGES
TO THE TEMPERATURES OR WINDS FOR THE OVERNIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THIS EVENING/...
NORTHWEST FLOW ALOFT WILL LIKELY CARRY ANY SHORTWAVES AND TSTM
ACTIVITY AWAY FROM OUR CWA LATE TONIGHT AND TUE. DRIER BUT STILL
RATHER WARM AIR WILL BE ACROSS THE REGION TUESDAY. WE WILL JUST KEEP
LOW CHC POPS FOR A TSTM ACROSS THE AREA TUE WITH SOMEWHAT HIGHER CHC
ACROSS THE LOWER DELMARVA. HIGH TEMPERATURES TUE WILL BE MOSTLY IN
THE UPPER 80S TO LOW 90S...BUT SOME MID 90S MAY OCCUR OVER DELAWARE
AND THE MD ERN SHORE. HUMIDITY LEVELS WILL BE LESS THAN TODAY SO
HEAT INDEX VALUES WILL BE LOW ENOUGH TO PRECLUDE ANY HEAT HEADLINES
ATTM.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
WE HAVE SEEN SIMILAR INITIALIZATION WINNERS AGAIN TODAY WITH THE GFS
SLIGHTLY BETTER THAN THE WRF-NMMB AT 850MB (TEMPS AND DEWS) AND
925MB AND THE WRF-NMMB AT 500MB. SO THE GENERAL IDEAS OF THE
WRF-NMMB WERE FOLLOWED MORE WITH THE GFS THERMAL FIELDS USED FOR
SFC ADJUSTMENTS.
WE CONTINUED A LOW CHANCE EARLY FOR LEFTOVER TSTMS SOUTH. OTHERWISE,
CLEARING AND COOLER WEATHER IS FORECAST FOR TUESDAY NIGHT. BECAUSE
THE GRADIENT MIGHT BE SUFFICIENT, WE DID NOT LOWER THE MINS TO THE
DEW POINTS. STAT GUIDANCE OVERALL LOOKS REASONABLE.
WEDNESDAY STILL IS ON TAP TO BE "THE DAY" THIS WEEK WITH MOSTLY
SUNNY SKIES AND LOW HUMIDITY LEVELS. FCST 1000-850MB THICKNESSES AND
925MB TEMPS ARE STILL SUGGESTING A WARM DAY WITH MANY MAX TEMPS IN
THE MID TO UPPER 80S PRETTY MUCH IN LINE WITH CURRENT FCST AND STAT
GUIDANCE.
THE MODEL TREND BEYOND WEDNESDAY HAS BEEN TOWARD A FASTER RETURN OF
HOTTER AND MORE HUMID WEATHER AS WELL AS PRECIPITATION CHANCES. AN
ANOMALOUSLY STRONG LOW PRESSURE SYSTEM FOR JULY IS EXPECTED TO PASS
NORTH OF OUR CWA ON THURSDAY. WHILE THE GFS SOLUTION IS A VERY
ROBUST OUTLIER, THE GENERAL IDEA OF THE OTHER MODELS ARE THE
SAME. WE HAVE STARTED THE CHANCE OF WAA INDUCED PRECIPITATION IN
THE NORTHERN PART OF OUR CWA AFTER MIDNIGHT. ITS POSSIBLE THUNDER
MIGHT GET INVOLVED. BUT GIVEN THE GFS ROBUST SOLUTION IS THE
QUICKEST, WE OPTED TO LEAVE IT OUT FOR NOW. ITS ALSO POSSIBLE THAT
THE WAA INDUCED PCPN MIGHT STAY NORTH OF OUR CWA, BUT EVENTS LIKE
THIS TEND TO SEEP SOUTH MORE THAN THE MODELS THINK.
EVEN THROTTLING BACK THE GFS TO THE FOLD ON THURSDAY, IT SHOULD BE A
HOTTER AND MORE HUMID DAY WITH LEGITIMATE THUNDERSTORM CHANCES.
HIGHEST POPS ARE NORTH CLOSER PROXIMITY TO THE SURFACE LOW AND
FRONTAL BOUNDARY. MAX TEMPS WERE NUDGED UP SOUTH BASED ON SOME BREAK
IN THE CLOUDS. BECAUSE OF THE TREND, WE ARE EDGING CLOSER TO HEAT
CRITERIA FOR URBAN AREAS.
THEN FROM THURSDAY NIGHT INTO SATURDAY, THE FRONTAL BOUNDARY IS
EXPECTED TO REMAIN CLOSE TO OUR CWA. THIS PACKAGE CONTINUED TO LEAN
CLOSER TO THE HPC AND ECMWF SOLUTION THAN THE GFS PARTLY BECAUSE OF
CONTINUITY AND ALSO BECAUSE OF THE RECENT 12Z GFS RUN. THIS
SHOULD BE A RATHER UNSETTLED PERIOD WITH SCATTERED SHOWERS AND
THUNDERSTORMS AROUND UNTIL THE FRONT PASSES ABOUT SATURDAY.
ON SUNDAY, THE FRONTAL SYSTEM SHOULD BE MOVING OFFSHORE AND OUT TO
SEA. HOWEVER, THERE MAY BE SOME LINGERING SHOWERS, ESPECIALLY EARLY,
BEFORE THE MID-LEVEL TROUGH FULLY MOVES THROUGH. BY SUNDAY NIGHT
INTO MONDAY, HIGH PRESSURE AT THE SURFACE IS EXPECTED TO BUILD INTO
THE REGION, WHICH SHOULD PROVIDE DRY WEATHER. THE GFS INDICATES THAT
WE MAY GET SOME SHOWER ACTIVITY DEVELOP DURING THE DAY MONDAY, WHILE
THE ECMWF KEEPS IT DRY. SINCE IT`S PRETTY FAR OUT, WE WILL GO POP
LESS AT THIS TIME. WITH WEAK TROUGHING ACROSS THE NORTHEAST,
TEMPERATURES ARE EXPECTED TO BE RIGHT AROUND NORMAL FOR SUNDAY AND
MONDAY.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
VFR CONDITIONS CONTINUE EARLY THIS MORNING ACROSS THE REGION. PATCHY
FOG IS TRYING TO FORM IN LOCATIONS THAT SAW RAIN MONDAY AFTERNOON
AND EVENING. PLACES LIKE KRDG...KABE AND KMIV MAY SEE PATCHY MVFR
FOG...MAINLY BETWEEN 0800 AND 1100 UTC. SCATTERED THUNDERSTORMS ARE
EXPECTED TO REMAIN NORTH OF THE TERMINAL LOCATIONS DURING THE EARLY
MORNING HOURS.
VFR CONDITIONS ARE EXPECTED TODAY...AS A COLD FRONT CROSSES THE
REGION. SCATTERED THUNDERSTORMS ARE EXPECTED ALONG THE FRONT...BUT
MAINLY SOUTH OF THE AREA. THERE IS A LOW PROBABILITY THAT KILG...
KACY AND KMIV COULD SEE A THUNDERSTORM BETWEEN 1600 AND 2100 UTC.
HOWEVER...THE PROBABILITIES WERE NOT HIGH ENOUGH TO INCLUDE IN THE
NEW TERMINAL FORECASTS. WEST TO WEST NORTHWEST WINDS WILL GUST
BETWEEN 21 AND 26 KNOTS BETWEEN 1500 AND 2300 UTC.
VFR CONDITIONS ARE EXPECTED TONIGHT UNDER MAINLY CLEAR SKIES. THE
NORTHERLY GRADIENT WILL INCREASE AFTER 0300 UTC...AND A FEW GUSTS
ARE POSSIBLE AT KACY BETWEEN 0600 UTC AND 0900 UTC WEDNESDAY.
OUTLOOK...
WEDNESDAY AND WEDNESDAY NIGHT...VFR CONDITIONS.
THURSDAY...VFR CONDITIONS FOR THE MORNING. SCATTERED SHOWERS AND
TSTMS MAY PRODUCE SOME MVFR IN THE LATTER PART OF THE DAY.
THURSDAY NIGHT THROUGH FRIDAY...SHWR AND TSTM ACTIVITY
ASSOCIATED WITH A WARM FRONT IS EXPECTED TO YIELD MVFR OR EVEN IFR
FOR A TIME.
FRIDAY NIGHT AND SATURDAY...SOME MVFR TO IFR CONDITIONS POSSIBLE IN
FOG AND LOW CLOUDS FRIDAY NIGHT AND ANY SHOWERS AND TSTMS FRIDAY
NIGHT AND SATURDAY.
&&
.MARINE...
NO MARINE FLAGS WILL BE NEEDED DURING THE OVERNIGHT, AND LIKELY
NONE WILL BE NEEDED ON TODAY. SCT TSTMS WITH LOCAL HIGHER WINDS/SEAS
ARE THE PRIMARY HAZARDS IN THE SHORT TERM. SYNOPTIC WINDS MOSTLY S
OR SW TODAY THEN N OR NW TUESDAY. WIND SPEEDS MOSTLY 10 TO 15 KTS
WITH A FEW G20 TODAY.
OUTLOOK...
THERE IS A CHANCE FOR SMALL CRAFT ADVISORY CRITERIA TONIGHT
ON THE OCEAN IN THE COOL AIR ADVECTION. EVEN IF IT WERE TO OCCUR,
THE DURATION IS LIKELY TO BE CONFINED TO JUST TONIGHT. BEYOND THAT
WINDS AND SEAS SHOULD BE FURTHER AWAY FROM SMALL CRAFT ADVISORY
CRITERIA ON WEDNESDAY AS WEAKENING HIGH PRESSURE BUILDS INTO THE
COASTAL WATERS.
THE NEXT CHANCE FOR SMALL CRAFT ADVISORY CONDITIONS MAY COME ON
THURSDAY IN THE SOUTHWEST FLOW BETWEEN THE DEPARTING HIGH AND THE
APPROACHING LOW PRESSURE SYSTEM. BECAUSE THE GFS SOLUTION WAS SO
ROBUST, WE TOOK ABOUT 1 TO 2 FT OFF THE 12Z WAVE WATCH GUIDANCE AND
ARE NOT CONFIDENT ABOUT GRADIENT WIND GUSTS REACHING THE CRITERIA.
HIGHER CHANCE OVER THE OCEAN THAN THE BAY. WE WILL CONTINUE TO
MONITOR.
AFTER THURSDAY NIGHT, THE FRONTAL PROXIMITY SHOULD KEEP WINDS AND
SEAS BELOW CRITERIA AGAIN INTO SATURDAY WITH LOCAL CONDITIONS AROUND
THUNDERSTORMS AND POSSIBLY SOME FOG BEING THE LARGER MARINE
THREATS.
&&
.RIP CURRENTS...
THE IS A MODERATE RISK OF RIP CURRENTS FORECAST TODAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GIGI/KLINE
NEAR TERM...HAYES
SHORT TERM...O`HARA
LONG TERM...GIGI/ROBERTSON
AVIATION...GIGI/HAYES/KLINE
MARINE...GIGI/KLINE/O`HARA
RIP CURRENTS...DELISI
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1159 AM EDT Tue Jul 24 2012
.NEAR TERM [Through Tonight]...
This mornings upper level RAP analysis shows the ridge centered
over the middle Mississippi Valley nosing southeast into our local
area. At the surface, a weak tropical low is found centered in
Apalachee Bay, sandwiched between two areas of high pressure.
This mornings sounding was slightly more moist than this time
yesterday, with most of this moisture residing in the the lower
troposphere. The aforementioned upper level ridge is responsible
for the drier middle to upper levels, especially across Alabama
and Georgia. Nevertheless, low level convergence associated with
the embattled wind field between the surface low and high pressure
systems will provide the mesoscale forcing needed to generate
showers and thunderstorms this afternoon. The best moisture will
be found across portions of north Florida, as clearly noted by the
early onset of CU this morning. Deep moist convection is not
expected for most areas this afternoon, storms that form will
remain rather shallow and benign. The only exception may be across
the panhandle of Florida and extreme SE Alabama, where a storm or
two may become mature enough to produce sub-severe downbursts.
Although the dry air will limit the deep convection, still expect
a rather healthy scattering of storms along the convergent zone
from say Albany, southwest to Pensacola. This loosely organized
line of storms will drift southeast through the late afternoon and
evening and diminish before midnight. Will have to be aware of the
evolution of convection across the Mid-Atlantic states this
afternoon as there are subtle hints of an MCS diving southwest
into our region late this evening. However, confidence in this
solution is low.
Max temperatures today will be similar to yesterday, warmer closer
to the upper ridge (NW) and more seasonable elsewhere (SW).
&&
.SHORT TERM [Wednesday Through Thursday]...
Wednesday, the upper ridge will build closer to the region
keeping temps above climo. Most areas along and north of I-10 will
reach the mid to upper 90s with maximum heat indices of 107-109
across the northern half of the forecast area. PoPs will also
increase to around climo (40-60). Thursday will be very similar to
Wednesday.
&&
.LONG TERM [Thursday Night through Monday]...
Not too much change to the previous thinking for the long term
forecast this cycle. The large ridge that has been in place across
the Southeast will gradually break down as the overall pattern
shifts to a trough in the Eastern CONUS and a ridge out west. Both
the GFS and Euro are consistent in bringing a weak frontal boundary
into the region by the weekend. PoPs are expected to increase
slightly this weekend as a result of the weakening ridge/approaching
boundary and the daily sea breeze circulation. This boundary should
weaken and dissipate by the first of the week, but with the presence
of the East Coast trough, rain chances late in the period are
expected to remain near climatological norms.
The temps will not vary greatly during the long term forecast, with
lows in the upper 70s and during the day the highs reaching mid 90s.
&&
.AVIATION [Beginning 16Z Tuesday]...
VFR conditions expected for the remainder of the afternoon.
Scattered storms are expected to impact KABY, KDHN, and KECP later
this afternoon. The storms have the potential to impact KTLH and
KVLD closer to the evening hours. Areas receiving rain will have a
greater threat of experiencing IFR to MVFR fog, transitioning to
low ceilings tomorrow morning.
&&
.MARINE...
The surface ridge axis will remain parked south of the area through
the entire forecast period. Therefore we can expect mainly southwest
winds (occasionally west) at speeds below headline criteria. There
will be some modest enhancement near the coast in the afternoon sea
breeze and of course near any convection.
&&
.FIRE WEATHER...
With low level south to southwesterly flow persisting through much
of this week, moisture levels are expected to remain well above
critical thresholds precluding red flag criteria.
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...Harrigan
SHORT TERM...Wool
LONG TERM...Godsey
AVIATION...
MARINE...Wool
FIRE WEATHER...Godsey
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
946 PM EDT WED JUL 25 2012
.UPDATE...
ONLY A FEW SHOWERS LINGER AROUND THE CSG AREA AND WILL THEREFORE
REMOVE ALL POPS EXCEPT FOR CSG AREA AND TAKE OUT ALL THUNDER. NO
OTHER CHANGES PLANNED.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
/ISSUED AT 337 PM EDT WED JUL 25 2012/
MAIN FORECAST CONCERN IS HEAT TODAY AND THURSDAY ALONG WITH
CONVECTION DEVELOPMENT BOTH AFTERNOONS. CURRENT TEMPS HAVE BEEN
RIGHT ON TRACK WITH FORECAST AND AREAS IN THE SOUTH ARE IN LINE FOR
REACHING HEAT ADVISORY CRITERIA...THEREFORE WILL CONTINUE CURRENT
PRODUCT. GENERALLY WENT WITH BLEND OF MAV AND MET SOLUTIONS FOR
TEMPS INTO TOMORROW NIGHT. AREAS IN THE EAST CENTRAL AND SOUTHEAST
PORTIONS LOOK TO AGAIN REACH OVERNIGHT MIN TEMPS OF AT LEAST 75
DEGREES AND PEAK HEAT INDICES OF AT LEAST 105 DEGREES TOMORROW. FOR
850 MB TEMPS...THE GFS HAS SIMILAR VALUES TO SLIGHTLY WARMER FOR
THURSDAY AFTERNOON WHILE THE NAM GOES SLIGHTLY COOLER PARTICULARLY
IN THE SOUTHWEST PORTION. THIS IS LIKELY DUE TO A SLUG OF TROPICAL
MOISTURE AND ASSOCIATED CLOUD COVER PROGGED TO ADVECT NORTHWARD INTO
THE AREA FROM THE NE GULF COAST. ATTM IT APPEARS THAT EXTENDING THE
CURRENT HEAT ADVISORY INTO THURSDAY EARLY EVENING FOR THE EAST
CENTRAL AND SOUTHEAST PORTIONS WOULD BE REASONABLE WITH PERHAPS
TRIMMING OUT THE SOUTHWEST. THIS DECISION WILL BE BEST MADE LATER
THIS AFTERNOON INTO EARLY EVENING SO AS TO PREVENT CONFUSION WITH
CURRENT PRODUCT... THEREFORE PLEASE STAY TUNED TO FUTURE UPDATES.
THE OUTFLOW FROM MCS REMNANTS ACROSS THE CAROLINAS EARLIER TODAY HAS
SERVED MOSTLY TO STABILIZE THE ENVIRONMENT ACROSS THE EASTERN
PORTION OF THE AREA. THE SOUTHERN AND WESTERN PERIPHERIES OF THIS
FEATURE MAY FOCUS DEVELOPMENT LATER TODAY...HOWEVER THE HRRR DOES
NOT BUY INTO THIS MUCH AND JUST HAS THE MAIN DEVELOPMENT IN THE
SOUTHWEST. CURRENT VIS SATELLITE IMAGERY HAS SHOWN SOME CU FIELD
ENHANCEMENTS WITH THE ASSOCIATED OUTFLOW AND PERHAPS WEAK GRAVITY
WAVES... BUT EARLY SHOWER AND THUNDERSTORM DEVELOPMENT HAS BEEN
CLOSER TO THE SW PORTION OF THE AREA. HAVE THEREFORE GONE WITH
HIGHER CHANCE POPS IN THE SW TAPERING TO SLIGHT POPS IN THE NW.
MLCAPE VALUES OF 2500-3500 J/KG...WEAK VERTICAL WIND SHEAR...AND PW
VALUES OF 1.8-2.0 INCHES WILL ALLOW FOR THE MAIN STORM THREATS BEING
STRONG WINDS...HEAVY RAINFALL...FREQUENT LIGHTNING...AND SMALL HAIL.
ISOLATED SEVERE STORMS ARE POSSIBLE AS WELL... ESPECIALLY IN THE
SOUTHWEST WHERE SPC ALSO HAS A SLIGHT RISK ISSUED.
WITH THE UPPER RIDGE AXIS OVER THE GREAT LAKES PROGGED TO DAMPEN OUT
AND BREAK DOWN...THE ASSOCIATED NW FLOW ALOFT EXTENDING INTO THE
CAROLINAS SHOULD WEAKEN AND BECOME MORE ZONAL BY 12Z THURSDAY. THE
COMBINATION OF A WEAK LEE SFC TROUGH AND ENHANCED MOISTURE FROM THE
ADVECTION OF THE AFOREMENTIONED TROPICAL PLUME IN THE NE GULF WILL
ALLOW FOR THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS AGAIN IN THE
SOUTH ON THURSDAY. GUIDANCE IS IN GOOD AGREEMENT WITH A DEVELOPING
UPPER TROUGH APPROACHING THE NORTHERN PORTION OF THE AREA BY LATE
THURSDAY NIGHT...ALONG WITH AN ASSOCIATED SFC FRONT. THIS MAY
INCREASE PRECIP POTENTIAL IN THE NORTHERN PORTION THURSDAY NIGHT
INTO FRIDAY.
03
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
/ISSUED AT 337 PM EDT WED JUL 25 2012/
HAVE MADE NO CHANGES TO THE LONG TERM. MODELS CONSISTEND IN SHOWING
A FRONTAL BOUNDARY SINKING INTO THE CWA SATURDAY INTO SUNDAY.
NORTH GA MAY BE DRY SATURDAY NIGHT INTO SUNDAY NIGHT BUT MOISTURE
RETURNS BY THE FIRST OF THE WEEK.
41
.PREVIOUS DISCUSSION/ISSUED 421 AM WED JUL 25 2012/
HIGH PRESSURE RIDGE OVER THE AREA WEAKENS AND SINKS SOUTH IN THE
SHORT TERM. BY FRI...THE RIDGE AXIS IS OVER FL AND THE GULF AND AN
APPROACHING COLD FRONT IS MOVING SOUTH OUT OF THE UPPER MS RIVER
VALLEY. THIS RIDGE STILL DOMINATES THE WEATHER PATTERN THROUGH THE
END OF THE WORK WEEK KEEPING NORTH AND CENTRAL GA IN MOIST WEST TO
SOUTHWESTERLY FLOW. PRECIPITABLE WATER VALUES STILL SHOWING NEAR
1.5 TO 1.8 INCH SO HEAVY RAIN WILL STILL BE A CONCERN...AT LEAST
THROUGH FRI. DIURNALLY DRIVEN THUNDERSTORMS WILL CONTINUE THROUGH
FRIDAY...BUT THEN THINGS BEGIN TO CHANGE SAT. A DEEP CLOSED LOW
CENTER TRACKS EAST ACROSS THE GREAT LAKES STATES AND INTO THE NEW
ENGLAND STATES THU...WITH ITS ASSOCIATED COLD FRONT MOVING
SOUTHWARD. THIS FRONT MOVES INTO NORTH GA BY 00Z SAT AND CONTINUES
MOVING SOUTHWARD INTO NORTH FL BY 12Z-18Z SUN. THIS FRONT BRINGS
IN A MUCH DRIER AIRMASS AND COOLER TEMPS FOR THE STATE SUN. HAVE
BACKED OFF ON POPS FOR SUN TO JUST ISOLATED TSRA MAINLY FOR
CENTRAL GA. MOISTURE DOES INCREASE AGAIN MON/TUE SO WILL KEEP
ISO/SCT SHRA/TSRA BACK IN THE FORECAST MON/TUE.
01
&&
.CLIMATE...
RECORDS FOR 07-25
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 101 1981 74 2000 75 1983 61 1947
1952 1911
1912
KATL 102 1995 74 1882 78 2010 60 1882
KCSG 103 1952 82 1998 80 2010 66 1948
1983
KMCN 103 1952 79 1938 79 2010 64 2009
1909
1902
RECORDS FOR 07-26
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 103 2010 80 1904 76 2005 56 1911
1936
KATL 98 1901 78 1890 77 2005 59 1911
KCSG 99 2010 82 1954 79 1983 66 1948
KMCN 100 2010 80 1957 78 2005 60 1911
1993
&&
AVIATION...
00Z UPDATE...
CONVECTION ACROSS CENTRAL GA WILL DISSIPATE AFTER SUNSET. ELSEWHERE
IT WILL REMAIN DRY WITH WINDS GOING CALM/NEAR CALM. A REPEAT
THURSDAY...ALTHOUGH THE CONVECTION MAYBE A BIT FURTHER NORTH INTO
THE ATL/AHN AREAS AND WILL ADD PROB30 ALL AREAS AFTER 21Z THURSDAY.
WINDS WILL BE WESTERLY THURSDAY.
//ATL CONFIDENCE...
00Z UPDATE...
HIGH ON ALL ELEMENTS.
17
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 73 98 74 98 / 20 20 20 30
ATLANTA 76 96 75 94 / 10 30 20 40
BLAIRSVILLE 68 91 69 90 / 10 20 20 50
CARTERSVILLE 72 96 73 94 / 10 20 20 50
COLUMBUS 76 95 75 93 / 20 40 30 40
GAINESVILLE 74 93 74 94 / 20 20 20 40
MACON 75 96 74 97 / 20 40 30 30
ROME 73 97 73 94 / 10 20 20 50
PEACHTREE CITY 73 95 73 94 / 10 30 20 40
VIDALIA 78 100 77 97 / 20 30 20 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR THE FOLLOWING
ZONES: BALDWIN...BIBB...BLECKLEY...CHATTAHOOCHEE...CRAWFORD...
CRISP...DODGE...DOOLY...EMANUEL...GLASCOCK...GREENE...HANCOCK...
HARRIS...HOUSTON...JEFFERSON...JOHNSON...JONES...LAURENS...
MACON...MARION...MONROE...MONTGOMERY...MUSCOGEE...PEACH...
PULASKI...PUTNAM...SCHLEY...STEWART...SUMTER...TALBOT...
TALIAFERRO...TAYLOR...TELFAIR...TOOMBS...TREUTLEN...TWIGGS...
UPSON...WARREN...WASHINGTON...WEBSTER...WHEELER...WILCOX...
WILKES...WILKINSON.
&&
$$
SHORT TERM...BAKER
LONG TERM....41
AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
736 PM EDT WED JUL 25 2012
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
/ISSUED AT 337 PM EDT WED JUL 25 2012/
MAIN FORECAST CONCERN IS HEAT TODAY AND THURSDAY ALONG WITH
CONVECTION DEVELOPMENT BOTH AFTERNOONS. CURRENT TEMPS HAVE BEEN
RIGHT ON TRACK WITH FORECAST AND AREAS IN THE SOUTH ARE IN LINE FOR
REACHING HEAT ADVISORY CRITERIA...THEREFORE WILL CONTINUE CURRENT
PRODUCT. GENERALLY WENT WITH BLEND OF MAV AND MET SOLUTIONS FOR
TEMPS INTO TOMORROW NIGHT. AREAS IN THE EAST CENTRAL AND SOUTHEAST
PORTIONS LOOK TO AGAIN REACH OVERNIGHT MIN TEMPS OF AT LEAST 75
DEGREES AND PEAK HEAT INDICES OF AT LEAST 105 DEGREES TOMORROW. FOR
850 MB TEMPS...THE GFS HAS SIMILAR VALUES TO SLIGHTLY WARMER FOR
THURSDAY AFTERNOON WHILE THE NAM GOES SLIGHTLY COOLER PARTICULARLY
IN THE SOUTHWEST PORTION. THIS IS LIKELY DUE TO A SLUG OF TROPICAL
MOISTURE AND ASSOCIATED CLOUD COVER PROGGED TO ADVECT NORTHWARD INTO
THE AREA FROM THE NE GULF COAST. ATTM IT APPEARS THAT EXTENDING THE
CURRENT HEAT ADVISORY INTO THURSDAY EARLY EVENING FOR THE EAST
CENTRAL AND SOUTHEAST PORTIONS WOULD BE REASONABLE WITH PERHAPS
TRIMMING OUT THE SOUTHWEST. THIS DECISION WILL BE BEST MADE LATER
THIS AFTERNOON INTO EARLY EVENING SO AS TO PREVENT CONFUSION WITH
CURRENT PRODUCT... THEREFORE PLEASE STAY TUNED TO FUTURE UPDATES.
THE OUTFLOW FROM MCS REMNANTS ACROSS THE CAROLINAS EARLIER TODAY HAS
SERVED MOSTLY TO STABILIZE THE ENVIRONMENT ACROSS THE EASTERN
PORTION OF THE AREA. THE SOUTHERN AND WESTERN PERIPHERIES OF THIS
FEATURE MAY FOCUS DEVELOPMENT LATER TODAY...HOWEVER THE HRRR DOES
NOT BUY INTO THIS MUCH AND JUST HAS THE MAIN DEVELOPMENT IN THE
SOUTHWEST. CURRENT VIS SATELLITE IMAGERY HAS SHOWN SOME CU FIELD
ENHANCEMENTS WITH THE ASSOCIATED OUTFLOW AND PERHAPS WEAK GRAVITY
WAVES... BUT EARLY SHOWER AND THUNDERSTORM DEVELOPMENT HAS BEEN
CLOSER TO THE SW PORTION OF THE AREA. HAVE THEREFORE GONE WITH
HIGHER CHANCE POPS IN THE SW TAPERING TO SLIGHT POPS IN THE NW.
MLCAPE VALUES OF 2500-3500 J/KG...WEAK VERTICAL WIND SHEAR...AND PW
VALUES OF 1.8-2.0 INCHES WILL ALLOW FOR THE MAIN STORM THREATS BEING
STRONG WINDS...HEAVY RAINFALL...FREQUENT LIGHTNING...AND SMALL HAIL.
ISOLATED SEVERE STORMS ARE POSSIBLE AS WELL... ESPECIALLY IN THE
SOUTHWEST WHERE SPC ALSO HAS A SLIGHT RISK ISSUED.
WITH THE UPPER RIDGE AXIS OVER THE GREAT LAKES PROGGED TO DAMPEN OUT
AND BREAK DOWN...THE ASSOCIATED NW FLOW ALOFT EXTENDING INTO THE
CAROLINAS SHOULD WEAKEN AND BECOME MORE ZONAL BY 12Z THURSDAY. THE
COMBINATION OF A WEAK LEE SFC TROUGH AND ENHANCED MOISTURE FROM THE
ADVECTION OF THE AFOREMENTIONED TROPICAL PLUME IN THE NE GULF WILL
ALLOW FOR THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS AGAIN IN THE
SOUTH ON THURSDAY. GUIDANCE IS IN GOOD AGREEMENT WITH A DEVELOPING
UPPER TROUGH APPROACHING THE NORTHERN PORTION OF THE AREA BY LATE
THURSDAY NIGHT...ALONG WITH AN ASSOCIATED SFC FRONT. THIS MAY
INCREASE PRECIP POTENTIAL IN THE NORTHERN PORTION THURSDAY NIGHT
INTO FRIDAY.
03
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
/ISSUED AT 337 PM EDT WED JUL 25 2012/
HAVE MADE NO CHANGES TO THE LONG TERM. MODELS CONSISTEND IN SHOWING
A FRONTAL BOUNDARY SINKING INTO THE CWA SATURDAY INTO SUNDAY.
NORTH GA MAY BE DRY SATURDAY NIGHT INTO SUNDAY NIGHT BUT MOISTURE
RETURNS BY THE FIRST OF THE WEEK.
41
.PREVIOUS DISCUSSION/ISSUED 421 AM WED JUL 25 2012/
HIGH PRESSURE RIDGE OVER THE AREA WEAKENS AND SINKS SOUTH IN THE
SHORT TERM. BY FRI...THE RIDGE AXIS IS OVER FL AND THE GULF AND AN
APPROACHING COLD FRONT IS MOVING SOUTH OUT OF THE UPPER MS RIVER
VALLEY. THIS RIDGE STILL DOMINATES THE WEATHER PATTERN THROUGH THE
END OF THE WORK WEEK KEEPING NORTH AND CENTRAL GA IN MOIST WEST TO
SOUTHWESTERLY FLOW. PRECIPITABLE WATER VALUES STILL SHOWING NEAR
1.5 TO 1.8 INCH SO HEAVY RAIN WILL STILL BE A CONCERN...AT LEAST
THROUGH FRI. DIURNALLY DRIVEN THUNDERSTORMS WILL CONTINUE THROUGH
FRIDAY...BUT THEN THINGS BEGIN TO CHANGE SAT. A DEEP CLOSED LOW
CENTER TRACKS EAST ACROSS THE GREAT LAKES STATES AND INTO THE NEW
ENGLAND STATES THU...WITH ITS ASSOCIATED COLD FRONT MOVING
SOUTHWARD. THIS FRONT MOVES INTO NORTH GA BY 00Z SAT AND CONTINUES
MOVING SOUTHWARD INTO NORTH FL BY 12Z-18Z SUN. THIS FRONT BRINGS
IN A MUCH DRIER AIRMASS AND COOLER TEMPS FOR THE STATE SUN. HAVE
BACKED OFF ON POPS FOR SUN TO JUST ISOLATED TSRA MAINLY FOR
CENTRAL GA. MOISTURE DOES INCREASE AGAIN MON/TUE SO WILL KEEP
ISO/SCT SHRA/TSRA BACK IN THE FORECAST MON/TUE.
01
&&
.CLIMATE...
RECORDS FOR 07-25
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 101 1981 74 2000 75 1983 61 1947
1952 1911
1912
KATL 102 1995 74 1882 78 2010 60 1882
KCSG 103 1952 82 1998 80 2010 66 1948
1983
KMCN 103 1952 79 1938 79 2010 64 2009
1909
1902
RECORDS FOR 07-26
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 103 2010 80 1904 76 2005 56 1911
1936
KATL 98 1901 78 1890 77 2005 59 1911
KCSG 99 2010 82 1954 79 1983 66 1948
KMCN 100 2010 80 1957 78 2005 60 1911
1993
&&
AVIATION...
00Z UPDATE...
CONVECTION ACROSS CENTRAL GA WILL DISSIPATE AFTER SUNSET. ELSEWHERE
IT WILL REMAIN DRY WITH WINDS GOING CALM/NEAR CALM. A REPEAT
THURSDAY...ALTHOUGH THE CONVECTION MAYBE A BIT FURTHER NORTH INTO
THE ATL/AHN AREAS AND WILL ADD PROB30 ALL AREAS AFTER 21Z THURSDAY.
WINDS WILL BE WESTERLY THURSDAY.
//ATL CONFIDENCE...
00Z UPDATE...
HIGH ON ALL ELEMENTS.
17
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 73 98 74 98 / 20 20 20 30
ATLANTA 76 96 75 94 / 10 30 20 40
BLAIRSVILLE 68 91 69 90 / 10 20 20 50
CARTERSVILLE 72 96 73 94 / 10 20 20 50
COLUMBUS 76 95 75 93 / 20 40 30 40
GAINESVILLE 74 93 74 94 / 20 20 20 40
MACON 75 96 74 97 / 20 40 30 30
ROME 73 97 73 94 / 10 20 20 50
PEACHTREE CITY 73 95 73 94 / 10 30 20 40
VIDALIA 78 100 77 97 / 20 30 20 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR THE FOLLOWING
ZONES: BALDWIN...BIBB...BLECKLEY...CHATTAHOOCHEE...CRAWFORD...
CRISP...DODGE...DOOLY...EMANUEL...GLASCOCK...GREENE...HANCOCK...
HARRIS...HOUSTON...JEFFERSON...JOHNSON...JONES...LAURENS...
MACON...MARION...MONROE...MONTGOMERY...MUSCOGEE...PEACH...
PULASKI...PUTNAM...SCHLEY...STEWART...SUMTER...TALBOT...
TALIAFERRO...TAYLOR...TELFAIR...TOOMBS...TREUTLEN...TWIGGS...
UPSON...WARREN...WASHINGTON...WEBSTER...WHEELER...WILCOX...
WILKES...WILKINSON.
&&
$$
SHORT TERM...BAKER
LONG TERM....41
AVIATION...BAKER
AREA FORECAST DISCUSSION...CORRECTED
NWS CHARLESTON SC
546 PM EDT TUE JUL 24 2012
...SLIGHT RISK OF SEVERE THUNDERSTORMS...
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL REMAIN SOUTH OF THE AREA THROUGH THE
WEEK AS A TROUGH OF LOW PRESSURE PERSISTS INLAND. A WEAK COLD FRONT
MAY APPROACH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
A WEAK SURFACE TROUGH EXTENDS FROM SOUTHWEST GEORGIA THROUGH THE
EASTERN MIDLANDS INTO COASTAL NORTH CAROLINA. SCATTERED SHOWERS
AND TSTMS HAVE RECENTLY POPPED IN THE VICINITY OF THIS FEATURE
WITH THE LARGEST CONCENTRATION OCCURRING NEAR VIDALIA. WHILE THIS
ACTIVITY MAY LINGER FOR ANOTHER FEW HOURS WITHIN AN AXIS OF MODEST
INSTABILITY...WEAK SHEAR AND THE LACK OF AN UPPER LEVEL FORCING
MECHANISM SUGGESTS MOST OF THIS SHOULD DISSIPATE NEAR OR JUST
AFTER SUNSET.
FARTHER UPSTREAM...OUTFLOW GENERATED BY A LARGE MESOSCALE
CONVECTIVE SYSTEM /MCS/ MOVING THROUGH EASTERN NORTH CAROLINA WAS
MOVING SOUTH INTO THE SOUTH CAROLINA UPSTATE AND NORTHERN
MIDLANDS. SECONDARY OUTFLOW ASSOCIATED WITH CONVECTION MOVING
THROUGH THE NORTH CAROLINA MOUNTAINS WAS ALSO MOVING QUICKLY
SOUTH. BOTH ARE EXPECTED TO MERGE AND POTENTIALLY REFIRE A
SECONDARY AREA OF CONVECTION LATER THIS EVENING ACROSS CENTRAL AND
NORTHERN SOUTH CAROLINA AS SHORTWAVE ENERGY EMBEDDED IN THE
NORTHWEST FLOW ALOFT MOVES ACROSS NORTH CAROLINA. WHILE IT REMAINS
TO BE SEEN HOW THIS POTENTIAL SECONDARY MCS WILL EVOLVE...SEVERAL
HIGHER RESOLUTION MESOSCALE MODELS SUGGEST SCATTERED SHOWERS/TSTMS
WILL IMPACT PARTS OF SOUTHERN SOUTH CAROLINA. WITH MODEST
INSTABILITY IN PLACE AND RAP SHEAR PROFILES SHOWING 0-6KM BULK
SHEAR INCREASE TO NEAR 30 KT ACROSS THE MIDLANDS AFTER
SUNSET...SUSPECT THERE IS A REASONABLE CHANCE THAT SOME SORT OF
MCS COULD MAKE IT INTO PARTS OF THE LOCAL FORECAST AREA LATER THIS
EVENING...ESPECIALLY SHOULD A COLD POOL DEVELOP WITH UPSTREAM
CONVECTION.
WILL CONTINUE WITH A 20-50 POP REGIME FOR THE EVENING HOURS WITH
THE HIGHEST POPS CLUSTERED OVER THE CHARLESTON TRI-COUNTY AREA.
WILL ALSO KEEP A MENTION OF LARGE HAIL AND DAMAGING WINDS IN THE
VARIOUS GRIDDED PRODUCTS...MAINLY FROM COLLETON COUNTY NORTH INTO
THE CHARLESTON AND MONCKS CORNER AREAS. POPS WILL DROP OFF TO
SLIGHT CHANCE AFTER MIDNIGHT FOR ALL AREAS. FURTHER REFINEMENTS
WILL BE NEEDED AS THE EVENING PROGRESSES AND SHORT TERM MESOSCALE
TRENDS BECOME MORE APPARENT.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
THE 500 MB RIDGE AXIS IS PROGGED TO SHIFT OVER THE AREA ON WEDNESDAY
AND OFF THE EASTERN SEABOARD THURSDAY AND FRIDAY...ALLOWING THE
INLAND TROUGH TO STRENGTHEN. LOW-LEVELS WILL REMAIN VERY MOIST
THROUGH THE PERIOD WITH DEWPOINTS REMAINING IN THE MIDDLE 70S. THE
SEABREEZE LOOKS TO REMAIN PINNED NEAR THE COAST UNTIL LATER IN THE
AFTERNOONS DUE TO A DEEP WEST SOUTHWEST FLOW. HIGH TEMPS WILL REMAIN
ABOVE NORMAL WITH HIGHS IN THE MID AND UPPER 90S EACH DAY.
CONVECTION WILL LIKELY TAKE UNTIL EARLY AFTERNOON TO BEGIN POPPING
DUE TO A STRONG CAP IN PLACE. HEAT ADVISORY CONDITIONS MAY BE
REACHED IN SOME PLACES THURSDAY OR FRIDAY DUE TO VALUES REACHING
110F FOR 2-3 HOURS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE GREAT LAKES SHORT WAVE MOVES INTO THE NE SATURDAY...WHICH
AMPLIFIES THE TROUGH IN THE EAST. THE APEX OF THIS TROUGH STRETCHES
SOUTH TO GA/FL...AND IT MOVES LITTLE THROUGH SUNDAY. BEYOND THAT FOR
EARLY NEXT WEEK WE/RE NOT YET CERTAIN AS TO WHETHER OR NOT
ADDITIONAL SHORT WAVES DROP INTO THE TROUGH TO MAINTAIN ITS PLACE
OVER THE EAST AND SE...OR DOES IT REMAIN VOID OF ANY PERTURBATIONS
AND INSTEAD BEGINS TO LIFT OUT. AT THE SURFACE OUR CONFIDENCE IS
GOOD THAT THE INLAND TROUGH WILL REMAIN NOT FAR FROM THE LOCAL AREA
THROUGH THE WEEKEND. BUT THEN THE QUESTION REMAINS IS TO WHETHER OR
NOT A COLD FRONT IS ABLE TO REACH THE FORECAST AREA EARLY NEXT WEEK.
CLIMATOLOGY WOULD SUGGEST THE FRONT NEVER GETS THIS FAR SE...SO THIS
REMAINS TO BE SEEN. RAIN CHANCES WILL BE IN THE ISOLATED TO
SCATTERED RANGE OVER THE WEEKEND...THEN WE PREFER NOTHING MORE THAN
ISOLATED COVERAGE MONDAY AND TUESDAY SINCE OUR CONFIDENCE LOWERS.
TEMPS WILL REMAIN ABOVE SEASONAL LEVELS SATURDAY AND
SUNDAY...TRENDING BACK CLOSER TO NORMAL MONDAY AND TUESDAY.
&&
.AVIATION /22Z TUESDAY THROUGH SUNDAY/...
WE HAVE MAINTAINED PREVAILING VFR CONDITIONS THROUGH 18Z
WEDNESDAY. HOWEVER...THERE ARE INDICATIONS THAT AN MCS COULD
IMPACT THE AREA EARLY TONIGHT. PROSPECTS FOR THIS TO OCCUR ARE
GREATER AT KCHS THAN AT KSAV BUT ARE STILL PRETTY LOW SO WILL
MAINTAIN PROB30 ...THUS OUR INCLUSION OF A PROB30 FOR TSRA AT
KCHS FROM 01-05Z. IF ORGANIZED TSRA DOES DEVELOP...THEN STRONG
WINDS ARE POSSIBLE...WITH PERIODIC MVFR OR LOWER CONDITIONS TO
OCCUR.
EXTENDED AVIATION OUTLOOK...DIURNAL SHOWERS AND THUNDERSTORMS
POSSIBLE THROUGH THE WEEK.
&&
.MARINE...
TONIGHT...THE LOCAL WATERS WILL CONTINUE TO BE POSITIONED IN AN
AREA BETWEEN THE INLAND TROUGH OF LOW PRESSURE AND SUBTROPICAL HIGH
OVER THE ATLANTIC. THIS WILL MAINTAIN THE RELATIVELY TIGHT
PRESSURE GRADIENT AND KEEP THE LOW-LEVEL SW FLOW ELEVATED. WINDS
WILL MAINLY REMAIN BELOW 20 KT...HIGHEST ACROSS THE SC WATERS. SEAS
WILL RUN 2-4 FT WITHIN 20 NM...AND 4-5 FT BEYOND. THUNDERSTORMS
MAY MOVE INTO PORTIONS OF THE WATERS THIS EVENING...ESPECIALLY
THE SC WATERS...SOME OF WHICH WILL BE STRONG OR EVEN SEVERE WITH
DAMAGING WINDS AND FREQUENT LIGHTNING THE MAIN HAZARDS.
WEDNESDAY THROUGH SUNDAY...THE GRADIENT WILL RELAX A BIT ON
WEDNESDAY BUT TIGHTEN AGAIN THURSDAY INTO FRIDAY AS ATLANTIC HIGH
PRESSURE STRENGTHENS TO OUR EAST AND THE INLAND TROUGH DEEPENS.
CONDITIONS LOOK TO REMAIN BELOW SMALL CRAFT CRITERIA BUT WE COULD
SEE SOME SOLID 15-20 KTS DURING OVERNIGHT SURGES AND THE COASTAL
SEABREEZE COULD EXCEED 15 KT AT TIMES DURING THE AFTERNOONS. SEAS
WILL BE A MIXTURE OF SHORT PERIOD WIND DRIVEN WAVES AND LONGER
PERIOD SWELL WAVES...WITH THE RESULTING COMBINED SEAS MOSTLY HELD
AT OR BELOW 4 OR 5 FT.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...JRL
LONG TERM...
AVIATION...RJB
MARINE...
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
255 AM CDT TUE JUL 24 2012
.DISCUSSION...
857 PM...EVENING UPDATE...EXTENSIVE MID/HIGH CLOUDS CONTINUE TO
SPREAD SOUTHEAST ACROSS THE AREA THIS EVENING WITH SOME SPRINKLES
AND A FEW LIGHT SHOWERS. HAVE SEEN VERY LITTLE CONVECTIVE
DEVELOPMENT AND THESE TRENDS APPEAR TO CONTINUE INTO THE EARLY
MORNING HRS AND WILL BE BACKING OFF TO JUST A SLIGHT CHANCE OF
SHOWERS FOR THE REST OF THIS EVENING. A STRONGER WAVE CURRENTLY
MOVING SOUTHEAST ACROSS MN AND NORTHWEST WI APPEARS TO HAVE A BIT
BETTER ORGANIZED AREA OF PRECIP WITH IT...BUT STILL RATHER MEAGER.
AS THIS CONTINUES TO THE SOUTHEAST OVERNIGHT...SHORT RANGE
GUIDANCE STILL SUGGESTS THAT ADDITIONAL SHOWERS AND THUNDERSTORMS
MAY DEVELOP ACROSS NORTHERN IL AND NORTHWEST INDIANA...GENERALLY
AFTER 08Z- 09Z. FOR THIS REASON...WILL HANG ONTO GOING LIKELY POPS
BUT CONFIDENCE REGARDING COVERAGE ARE LOW. RATHER IMPRESSIVE
PRECIPITABLE WATER VALUES AT OR SLIGHTLY ABOVE 2 INCHES TOWARD
DAYBREAK TUESDAY...THUS ANYTHING THAT DOES DEVELOP WILL CONTINUE
TO HAVE THE POTENTIAL TO PRODUCE LOCALLY HEAVY RAIN. ELSEWHERE...
THE COLD FRONT CONTINUES TO SLOWLY SAG SOUTH AND APPEARS TO HAVE
SLOWED FROM PREVIOUS TIMING. WOULD EXPECT SOME MOISTURE POOLING
AHEAD OF THE FRONT BUT DEWPOINTS ARE ALREADY IN THE MID TO EVEN A
FEW UPPER 70S ACROSS THE AREA. OVERNIGHT HRS WILL REMAIN QUITE
WARM AND MUGGY. CMS
//PREV DISCUSSION...
342 PM CDT
MAIN CONCERNS AND QUESTIONS REVOLVE AROUND CHANCES FOR SHOWERS AND
THUNDERSTORMS LATE THIS AFTERNOON INTO THE
EVENING...OVERNIGHT...AS WELL AS OVER THE NEXT SEVERAL DAYS WITH
SEVERE WEATHER AND HEAVY RAINFALL A CONCERN FOR EACH TIME FRAME.
IN THE NEAR TERM...SCATTERED MID AND HIGH LEVEL CLOUD COVER
CONTINUE TO SPILL SOUTHEAST ACROSS MUCH OF THE CWA. ALTHOUGH THERE
HAVE BEEN SOME BREAKS OBSERVED TODAY...THE MAJORITY OF THE DAY HAS
OBSERVED PARTLY CLOUDY TO PARTLY SUNNY SKIES. THIS CLOUD COVER HAS
LIMITED OVERALL TEMPS TODAY WITH MOST AREAS NOT QUITE RISING AS
HIGH AS PREVIOUSLY ANTICIPATED. WITH THE BREAKS...IT DIDNT TAKE
MUCH FOR SURFACE TEMPS TO RISE INTO THE MID 90S WITH SOME ISOLATED
UPPER 90S. THIS GENERAL TREND HAS BEEN GOOD WITH REGARD TO THE
HEAT AND HUMIDITY WHICH WAS EXPECTED TODAY...AS DEWPOINTS DID NOT
QUITE MIX OUT WITH MANY LOCATIONS ACROSS NORTHERN ILLINOIS
CURRENTLY OBSERVING LOW TO MID 70 DEWPOINTS. AREAS MAY OBSERVE
TEMPS RISE A COUPLE OF DEGREES OVER THE NEXT COUPLE OF
HOURS...BEFORE THICKER CLOUD COVER UPSTREAM ACROSS SOUTHWEST
WISCONSIN MOVES SOUTHEAST ACROSS THE CWA AND STIFLES ANY FURTHER
HEATING. WITH SEVERAL RIPPLES IN THE FLOW ALOFT SHIFTING OVERHEAD
TODAY...SCATTERED LIGHT SHOWERS HAVE BEEN OBSERVED ACROSS THE
SOUTHWEST PORTION OF THE CWA TODAY WITH SOME ISOLATED LIGHTNING
STRIKES OBSERVED. WITH A DECENT CAP IN PLACE AND CLOUD COVER
HELPING TO LIMIT LOW AND MID LEVEL LAPSE RATES...CONVECTION HAS
BEEN KEPT IN CHECK TODAY. ALTHOUGH...CONCERNS AND QUESTIONS STILL
REMAIN FOR LATE THIS AFTERNOON INTO THE EVENING. HAVE BEEN
MONITORING A STRONGER MID LEVEL FEATURE DROPPING SOUTHEAST ACROSS
SOUTHEAST MINNESOTA AND SOUTHWEST WISCONSIN WITH LATEST RADAR
IMAGERY SHOWING SOME RETURNS/SHOWERS MOVING INTO EASTERN IOWA. MY
CONCERNS WITH THESE SHOWERS ARE THAT UPSCALE GROWTH COULD OCCUR AS
THEY ENCOUNTER A DESTABILIZING ATMOSPHERE OVER NORTHERN ILLINOIS.
LATEST RUC ANALYSIS IS INDICATING THAT THE ATMOSPHERE IS
DESTABILIZING WITH CIN ERODING AND LOW LEVEL LAPSE RATES
STEEPENING. ALTHOUGH THIS IS PROBABLY OCCURRING...I WONDER IF THIS
LATEST ANALYSIS MIGHT BE OVERDONE. WHERE FAIRLY STEEP LAPSE RATES
OVERLAP THIS MID LEVEL WAVE/SHOWERS...LIGHTNING AND UPSCALE GROWTH
HAS BEEN NONEXISTENT. ALSO...AS MID AND HIGH LEVEL CLOUD COVER
CONTINUE TO MOVE OVERHEAD...NOT ANTICIPATING ANY REAL GOOD
DESTABILIZATION TO CONTINUE ACROSS THE AREA WITH WARM AIR ALOFT
REMAINING. SO DESPITE MY CONCERNS...A BETTER SOLUTION FOR THE NEAR
TERM INTO THE EVENING ARE THAT SHOWERS MOVE INTO NORTHERN ILLINOIS
WITH SOME FURTHER DEVELOPMENT AND ISOLATED STRONGER
DEVELOPMENT...BUT WITH THE PREVIOUSLY MENTIONED LIMITING FACTORS
HELPING TO ONCE AGAIN KEEP THE CONVECTION AND ANY SEVERE POTENTIAL
IN CHECK.
CONCERNS THEN SHIFT TOWARDS LATE TONIGHT INTO EARLY TUESDAY
MORNING. ANOTHER STRONGER AND MORE DEFINED MID LEVEL WAVE NOTED ON
LATEST WATER VAPOR IMAGERY ACROSS THE DAKOTAS WILL DROP SOUTHEAST
ACROSS THE REGION. THIS WAVE WILL ENCOUNTER A STRENGTHENING LOW
LEVEL JET ADVECTING A VERY MOIST AIR MASS INTO IT AND OVER A LOW
LEVEL BAROCLINIC ZONE DROPPING SOUTH THROUGH THE CWA...WITH
DEVELOPMENT EXPECTED ACROSS CENTRAL WISCONSIN. THIS WAVE/FORCING
AND STEERING FLOW WILL SHIFT THIS CLUSTER OF SHOWERS/THUNDERSTORMS
SOUTHEAST ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA...WITH
THE BEST CHANCES EXPECTED NORTH OF LINE FROM DIXON IN ILLINOIS TO
FOWLER IN INDIANA AND THE BEST CHANCES WITH REGARDS TO TIMING
EXPECTED TO BE AFTER MIDNIGHT. AS THIS COMPLEX MOVES ACROSS THE
AREA IT WILL ENCOUNTER A VERY MOIST AND UNSTABLE ATMOSPHERE WITH
HIGH DEWPOINT/PWAT AIR IN PLACE. CONCERNS DURING THIS TIME FRAME
WOULD BE FOR SOME ISOLATED LARGE HAIL...BUT WITH CONCERNS MORE
TOWARD THE HEAVY RAIN POTENTIAL. ALTHOUGH THIS DOES NOT APPEAR TO
BE A CLASSIC HEAVY RAIN SETUP...MANY FEATURES ARE IN PLACE TO
PROVIDE SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS THAT WILL ALL
HAVE THE POTENTIAL TO PRODUCE HEAVY DOWNPOURS...INCLUDING LOW
LEVEL FLOW BRIEFLY ORIENTING ITSELF WITH REGARD TO THE BAROCLINIC
ZONE SUCH TO BRING AT LEAST SOME PERIOD OF POTENTIAL TRAINING OF
CELLS. WILL CONTINUE TO MAKE MENTION OF THESE THREATS IN THE HWO
AS WELL AS AN ESF.
RODRIGUEZ
THURSDAY THROUGH MONDAY...MEDIUM RANGE GUIDANCE IS IN PRETTY
DECENT AGREEMENT WITH THE MAIN FEATURES INTO EARLY NEXT WEEK.
SURFACE LOW PRESSURE WILL BE EXITING OFF TO THE EAST THURSDAY
MORNING WITH ITS TRAILING COLD FRONT SOMEWHERE NEAR THE AREA.
GUIDANCE DOES DIFFER ON HOW QUICKLY THE FRONT MOVES ACROSS THE
AREA THURSDAY. WILL KEEP POPS IN WITH THE BEST CHANCE DURING THE
MORNING BUT IT IS POSSIBLE THE FRONT COULD BE EXITING BY THAT
TIME. BEYOND THAT...A CLOSED UPPER LOW CURRENTLY SPINNING OVER
SOUTHERN BRITISH COLUMBIA WILL SLOWLY MOVE EASTWARD INTO UPPER
RIDGING OVER SASKATCHEWAN. BY THURSDAY MORNING...THE LOW WILL BE
IN THE VICINITY OF NORTHWEST MN/NORTHEAST NORTH DAKOTA HEADING
SOUTHEAST BRINGING A SURFACE LOW WITH IT. THIS WILL BEGIN TO
AFFECT THE AREA LATER THURSDAY NIGHT OR FRIDAY MORNING WITH
ANOTHER COOL FRONT DROPPING ACROSS THE AREA. AN UPPER TROUGH AXIS
LOOKS TO LAG THIS SYSTEM SO AT LEAST LOW PRECIP CHANCES WILL
LINGER INTO FRIDAY. SURFACE HIGH PRESSURE THEN ARRIVES INTO
SATURDAY MORNING AS UPPER RIDGING BECOMES RE-ESTABLISHED ACROSS
THE WESTERN U.S. A TROUGH MOVES THROUGH THE RIDGE SPAWNING SURFACE
LOW DEVELOPMENT ACROSS THE HIGH PLAINS LATER SATURDAY AND
SPREADING WARM ADVECTION EASTWARD ACROSS THE LOCAL AREA FOLLOWED
BY THE PASSAGE OF ANOTHER SURFACE LOW INTO MONDAY. THIS WHOLE
SYSTEM RESULTS IN CHANCES FOR SHOWERS AND STORMS FROM LATE SUNDAY
ON. TEMPS LOOK TO REMAIN MORE IN CHECK GIVEN PERIODIC CHANCES FOR
PRECIP...GENERALLY LOWER HEIGHTS OVER THE AREA AND OCCASIONAL
FRONTAL PASSAGES. DEPENDING ON FRONTAL TIMING THURSDAY...SOUTHERN
AREAS MAY REACH THE 90S...BUT OTHER THAN THAT WILL KEEP HIGHS IN
THE MID TO UPPER 80S FOR NOW.
MDB
&&
.CLIMATE...
400 AM CDT
RECORDS HIGHS FOR TODAY JULY 23RD ARE:
CHICAGO 99 /1914/
ROCKFORD 104 /1934/
RECORD WARM LOWS FOR TODAY JULY 23RD ARE:
CHICAGO 78 /1965/
ROCKFORD 76 /1965/
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* SHRA/TSRA EARLY-MID THIS MORNING.
* MVFR...POSSIBLY LOWER...VSBY IN TSRA THIS MORNING. POTENTIAL FOR MVFR
CIGS IN HEAVIER TSRA.
* TSRA TUESDAY AFTERNOON AND NIGHT.
* WIND TRENDS.
RC
//DISCUSSION...UPDATED 06Z...
FOCUS IN THE NEAR TERM IS NW TO SE ORIENTED CLUSTER OF SHRA/TSRA
EXTENDING INTO SE MN/SW WI. A COOL FRONT CONTINUES TO SLOWLY SAG
SOUTH THROUGH WISCONSIN AS WELL. RADAR TRENDS AND LATEST GUIDANCE
POINT TO MN/WI ACTIVITY HOLDING TOGETHER AND MOVING SOUTHEAST OVER
THE TERMINALS EARLY THROUGH MID THIS MORNING...ROUGHLY 9Z-13Z IN
RFD AREA AND 10Z-14Z IN ORD/MDW/DPA/GYY AREA. TIMING MAY NEED
REFINING IN 09Z UPDATE OR SOONER...BUT HAVE DECENT CONFIDENCE
THAT TERMINALS WILL SEE BOTH SHRA AND TSRA DUE TO LOW LEVEL JET
DIRECTING INTO AREA AND PLENTY OF ELEVATED INSTABILITY. THE FRONT
DROPPING SOUTH MAY ALSO PROVIDE A FOCUS FOR MAINTAINING THE
ACTIVITY. IT IS TOO EARLY TO TELL IF TSRA WILL DEVELOP
VARIABLE/GUSTY WINDS...THUS BIGGEST CONCERN IS AT LEAST TEMPORARY
MVFR VSBY IN TSRA AND POSSIBLY A FURTHER LOWERING OF CIGS THAN
INDICATED IN TAFS IN VERY MOIST AIRMASS. PRIOR TO ARRIVAL OF
SHRA/TSRA...CANNOT RULE OUT LIGHT SHRA BREAKING OUT...AND AM ALSO
CONCERNED ACTIVITY COULD LINGER LONGER SO CARRIED -SHRA TO 16/17Z
AT TAF SITES. WILL NEED TO MONITOR TRENDS. AFTER THE MORNING
ACTIVITY...THERE COULD BE ADDITIONAL SHRA/TSRA DURING THE
DAY...BUT NOT CONFIDENT ENOUGH FOR MENTION DURING THIS TIME. A
BETTER CHANCE MAY EXIST LATER IN THE EVENING AS THE FRONTAL
BOUNDARY LIFTS BACK NORTH. INDICATED PROB30 FOR TSRA IN RFD AND
ORD TAFS WITH THIS IN MIND.
WINDS CURRENTLY ARE VERY LIGHT OUT OF THE WEST WHERE THEY ARE NOT
COMPLETELY CALM AND SHOULD REMAIN FAIRLY LIGHT EVEN AS FRONT
PUSHES SOUTH THROUGH THE TERMINALS...TURNING WINDS NORTHEAST. WITH
SOME SITES NORTH OF MKE REPORTING SLIGHTLY STRONGER NORTHEAST
WINDS...WILL NEED TO WATCH FOR THIS OCCURRING AT ORD/MDW/GYY.
WINDS WILL STAY MORE NORTHEASTERLY AT THE EASTERN TAF SITES
BEFORE BECOMING EAST SOUTHEAST LATE TUESDAY EVENING. THE RFD AREA
IS LIKELY TO SEE WINDS EAST-NORTHEAST FOR A TIME AFTER THE FRONTAL
PASSAGE...BUT THEN BECOME EASTERLY BY LATE MORNING AND REMAIN SO
UNTIL POSSIBLY BECOMING MORE EAST-SOUTHEAST TOMORROW EVENING.
RC
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM/HIGH CONFIDENCE IN SHRA/TSRA OCCURRING AT TERMINALS EARLY
THROUGH MID THIS MORNING...LOW CONFIDENCE IN EXACT TIMING AND
DURATION.
* MEDIUM/HIGH CONFIDENCE IN AT LEAST TEMPO MVFR VSBY IN SHRA/TSRA
EARLY THROUGH MID THIS MORNING...LOW CONFIDENCE IN IFR VSBY AND
LOW CONFIDENCE IN MVFR CIGS.
* LOW CONFIDENCE IN TSRA THIS AFTERNOON AND LOW/MEDIUM CONFIDENCE
IN TSRA LATE THIS EVENING.
* MEDIUM CONFIDENCE IN WIND TRENDS...WITH LOW CONFIDENCE IN
NEEDING TO ADD GUSTS TO TSRA ACTIVITY THIS MORNING.
RC
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY THROUGH FRIDAY...CHANCES FOR OCCASIONAL TSRA...OTHERWISE
VFR.
SATURDAY...VFR.
SUNDAY...CHANCE FOR TSRA...ESPECIALLY LATE. OTHERWISE VFR.
RC
&&
.MARINE...
250 AM CDT
A COLD FRONT DROPPING SOUTH ACROSS THE REGION HAS ALL BUT CLEARED
FAR SOUTHERN LAKE MICHIGAN WITH NORTHERLY WINDS TAKING HOLD IN THE
WAKE OF THE FRONT. THIS MORNING...SHOWERS AND THUNDERSTORMS ARE
EXPECTED DEVELOP ALONG AND NORTH OF THE FRONT...IMPACTING THE
SOUTHERN THIRD OR SO OF LAKE MICHIGAN. HIGH PRESSURE WILL BUILD
ACROSS NORTHERN LAKE MICHIGAN TODAY ALLOWING WINDS TO SUBSIDE
ACROSS THE NORTH. WEDNESDAY...LOW PRESSURE WILL DEEPEN OVER THE
NORTHERN PLAINS AS IT MOVES INTO THE UPPER MIDWEST AND WESTERN
GREAT LAKES REGION. THE FRONTAL ZONE WILL LIFT BACK NORTH WITH
SOUTH TO SOUTHEASTERLY WINDS MOVING BACK UP THE LAKE. THE LOW IS
FORECAST TO CROSS MIDLAKE LATE WEDNESDAY EVENING CAUSING WINDS TO
BECOME NORTHEASTERLY ACROSS THE NORTHERN PORTIONS OF THE LAKE.
SOUTHWESTERLY WINDS THE SOUTHERN HALF OF THE LAKE WILL BECOME
NORTHWEST AFTER A TRAILING COLD FRONT SWEEPS ACROSS. WINDS WILL
INCREASE WEDNESDAY AND WEDNESDAY NIGHT...ESPECIALLY ACROSS THE
NORTHERN PART OF THE LAKE WHERE NORTHEAST WINDS TO 30 KT ARE
EXPECTED. ACROSS SOUTHERN LAKE MICHIGAN...20 TO 25 KT OF OFFSHORE
FLOW IS POSSIBLE WEDNESDAY EVENING...BUT A STABLE MARINE LAYER
SHOULD HELP KEEP WINDS IN CHECK OVER THE OPEN WATERS. A SMALL
CRAFT ADVISORY MAY BE NEEDED FOR THE INDIANA AND ILLINOIS
NEARSHORE WATERS. ANOTHER WEAKER LOW PRESSURE SYSTEM WILL CROSS
THE LAKE THURSDAY NIGHT CAUSING ADDITIONAL SHIFTS IN THE WIND
FIELD. HIGH PRESSURE IS EXPECTED TO BUILD INTO THE REGION THIS
WEEKEND OFFERING AT LEAST A BRIEF REPRIEVE FROM THE ACTIVE
WEATHER. BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
138 AM CDT TUE JUL 24 2012
.DISCUSSION...
857 PM...EVENING UPDATE...EXTENSIVE MID/HIGH CLOUDS CONTINUE TO
SPREAD SOUTHEAST ACROSS THE AREA THIS EVENING WITH SOME SPRINKLES
AND A FEW LIGHT SHOWERS. HAVE SEEN VERY LITTLE CONVECTIVE
DEVELOPMENT AND THESE TRENDS APPEAR TO CONTINUE INTO THE EARLY
MORNING HRS AND WILL BE BACKING OFF TO JUST A SLIGHT CHANCE OF
SHOWERS FOR THE REST OF THIS EVENING. A STRONGER WAVE CURRENTLY
MOVING SOUTHEAST ACROSS MN AND NORTHWEST WI APPEARS TO HAVE A BIT
BETTER ORGANIZED AREA OF PRECIP WITH IT...BUT STILL RATHER MEAGER.
AS THIS CONTINUES TO THE SOUTHEAST OVERNIGHT...SHORT RANGE
GUIDANCE STILL SUGGESTS THAT ADDITIONAL SHOWERS AND THUNDERSTORMS
MAY DEVELOP ACROSS NORTHERN IL AND NORTHWEST INDIANA...GENERALLY
AFTER 08Z- 09Z. FOR THIS REASON...WILL HANG ONTO GOING LIKELY POPS
BUT CONFIDENCE REGARDING COVERAGE ARE LOW. RATHER IMPRESSIVE
PRECIPITABLE WATER VALUES AT OR SLIGHTLY ABOVE 2 INCHES TOWARD
DAYBREAK TUESDAY...THUS ANYTHING THAT DOES DEVELOP WILL CONTINUE
TO HAVE THE POTENTIAL TO PRODUCE LOCALLY HEAVY RAIN. ELSEWHERE...
THE COLD FRONT CONTINUES TO SLOWLY SAG SOUTH AND APPEARS TO HAVE
SLOWED FROM PREVIOUS TIMING. WOULD EXPECT SOME MOISTURE POOLING
AHEAD OF THE FRONT BUT DEWPOINTS ARE ALREADY IN THE MID TO EVEN A
FEW UPPER 70S ACROSS THE AREA. OVERNIGHT HRS WILL REMAIN QUITE
WARM AND MUGGY. CMS
//PREV DISCUSSION...
342 PM CDT
MAIN CONCERNS AND QUESTIONS REVOLVE AROUND CHANCES FOR SHOWERS AND
THUNDERSTORMS LATE THIS AFTERNOON INTO THE
EVENING...OVERNIGHT...AS WELL AS OVER THE NEXT SEVERAL DAYS WITH
SEVERE WEATHER AND HEAVY RAINFALL A CONCERN FOR EACH TIME FRAME.
IN THE NEAR TERM...SCATTERED MID AND HIGH LEVEL CLOUD COVER
CONTINUE TO SPILL SOUTHEAST ACROSS MUCH OF THE CWA. ALTHOUGH THERE
HAVE BEEN SOME BREAKS OBSERVED TODAY...THE MAJORITY OF THE DAY HAS
OBSERVED PARTLY CLOUDY TO PARTLY SUNNY SKIES. THIS CLOUD COVER HAS
LIMITED OVERALL TEMPS TODAY WITH MOST AREAS NOT QUITE RISING AS
HIGH AS PREVIOUSLY ANTICIPATED. WITH THE BREAKS...IT DIDNT TAKE
MUCH FOR SURFACE TEMPS TO RISE INTO THE MID 90S WITH SOME ISOLATED
UPPER 90S. THIS GENERAL TREND HAS BEEN GOOD WITH REGARD TO THE
HEAT AND HUMIDITY WHICH WAS EXPECTED TODAY...AS DEWPOINTS DID NOT
QUITE MIX OUT WITH MANY LOCATIONS ACROSS NORTHERN ILLINOIS
CURRENTLY OBSERVING LOW TO MID 70 DEWPOINTS. AREAS MAY OBSERVE
TEMPS RISE A COUPLE OF DEGREES OVER THE NEXT COUPLE OF
HOURS...BEFORE THICKER CLOUD COVER UPSTREAM ACROSS SOUTHWEST
WISCONSIN MOVES SOUTHEAST ACROSS THE CWA AND STIFLES ANY FURTHER
HEATING. WITH SEVERAL RIPPLES IN THE FLOW ALOFT SHIFTING OVERHEAD
TODAY...SCATTERED LIGHT SHOWERS HAVE BEEN OBSERVED ACROSS THE
SOUTHWEST PORTION OF THE CWA TODAY WITH SOME ISOLATED LIGHTNING
STRIKES OBSERVED. WITH A DECENT CAP IN PLACE AND CLOUD COVER
HELPING TO LIMIT LOW AND MID LEVEL LAPSE RATES...CONVECTION HAS
BEEN KEPT IN CHECK TODAY. ALTHOUGH...CONCERNS AND QUESTIONS STILL
REMAIN FOR LATE THIS AFTERNOON INTO THE EVENING. HAVE BEEN
MONITORING A STRONGER MID LEVEL FEATURE DROPPING SOUTHEAST ACROSS
SOUTHEAST MINNESOTA AND SOUTHWEST WISCONSIN WITH LATEST RADAR
IMAGERY SHOWING SOME RETURNS/SHOWERS MOVING INTO EASTERN IOWA. MY
CONCERNS WITH THESE SHOWERS ARE THAT UPSCALE GROWTH COULD OCCUR AS
THEY ENCOUNTER A DESTABILIZING ATMOSPHERE OVER NORTHERN ILLINOIS.
LATEST RUC ANALYSIS IS INDICATING THAT THE ATMOSPHERE IS
DESTABILIZING WITH CIN ERODING AND LOW LEVEL LAPSE RATES
STEEPENING. ALTHOUGH THIS IS PROBABLY OCCURRING...I WONDER IF THIS
LATEST ANALYSIS MIGHT BE OVERDONE. WHERE FAIRLY STEEP LAPSE RATES
OVERLAP THIS MID LEVEL WAVE/SHOWERS...LIGHTNING AND UPSCALE GROWTH
HAS BEEN NONEXISTENT. ALSO...AS MID AND HIGH LEVEL CLOUD COVER
CONTINUE TO MOVE OVERHEAD...NOT ANTICIPATING ANY REAL GOOD
DESTABILIZATION TO CONTINUE ACROSS THE AREA WITH WARM AIR ALOFT
REMAINING. SO DESPITE MY CONCERNS...A BETTER SOLUTION FOR THE NEAR
TERM INTO THE EVENING ARE THAT SHOWERS MOVE INTO NORTHERN ILLINOIS
WITH SOME FURTHER DEVELOPMENT AND ISOLATED STRONGER
DEVELOPMENT...BUT WITH THE PREVIOUSLY MENTIONED LIMITING FACTORS
HELPING TO ONCE AGAIN KEEP THE CONVECTION AND ANY SEVERE POTENTIAL
IN CHECK.
CONCERNS THEN SHIFT TOWARDS LATE TONIGHT INTO EARLY TUESDAY
MORNING. ANOTHER STRONGER AND MORE DEFINED MID LEVEL WAVE NOTED ON
LATEST WATER VAPOR IMAGERY ACROSS THE DAKOTAS WILL DROP SOUTHEAST
ACROSS THE REGION. THIS WAVE WILL ENCOUNTER A STRENGTHENING LOW
LEVEL JET ADVECTING A VERY MOIST AIR MASS INTO IT AND OVER A LOW
LEVEL BAROCLINIC ZONE DROPPING SOUTH THROUGH THE CWA...WITH
DEVELOPMENT EXPECTED ACROSS CENTRAL WISCONSIN. THIS WAVE/FORCING
AND STEERING FLOW WILL SHIFT THIS CLUSTER OF SHOWERS/THUNDERSTORMS
SOUTHEAST ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA...WITH
THE BEST CHANCES EXPECTED NORTH OF LINE FROM DIXON IN ILLINOIS TO
FOWLER IN INDIANA AND THE BEST CHANCES WITH REGARDS TO TIMING
EXPECTED TO BE AFTER MIDNIGHT. AS THIS COMPLEX MOVES ACROSS THE
AREA IT WILL ENCOUNTER A VERY MOIST AND UNSTABLE ATMOSPHERE WITH
HIGH DEWPOINT/PWAT AIR IN PLACE. CONCERNS DURING THIS TIME FRAME
WOULD BE FOR SOME ISOLATED LARGE HAIL...BUT WITH CONCERNS MORE
TOWARD THE HEAVY RAIN POTENTIAL. ALTHOUGH THIS DOES NOT APPEAR TO
BE A CLASSIC HEAVY RAIN SETUP...MANY FEATURES ARE IN PLACE TO
PROVIDE SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS THAT WILL ALL
HAVE THE POTENTIAL TO PRODUCE HEAVY DOWNPOURS...INCLUDING LOW
LEVEL FLOW BRIEFLY ORIENTING ITSELF WITH REGARD TO THE BAROCLINIC
ZONE SUCH TO BRING AT LEAST SOME PERIOD OF POTENTIAL TRAINING OF
CELLS. WILL CONTINUE TO MAKE MENTION OF THESE THREATS IN THE HWO
AS WELL AS AN ESF.
RODRIGUEZ
THURSDAY THROUGH MONDAY...MEDIUM RANGE GUIDANCE IS IN PRETTY
DECENT AGREEMENT WITH THE MAIN FEATURES INTO EARLY NEXT WEEK.
SURFACE LOW PRESSURE WILL BE EXITING OFF TO THE EAST THURSDAY
MORNING WITH ITS TRAILING COLD FRONT SOMEWHERE NEAR THE AREA.
GUIDANCE DOES DIFFER ON HOW QUICKLY THE FRONT MOVES ACROSS THE
AREA THURSDAY. WILL KEEP POPS IN WITH THE BEST CHANCE DURING THE
MORNING BUT IT IS POSSIBLE THE FRONT COULD BE EXITING BY THAT
TIME. BEYOND THAT...A CLOSED UPPER LOW CURRENTLY SPINNING OVER
SOUTHERN BRITISH COLUMBIA WILL SLOWLY MOVE EASTWARD INTO UPPER
RIDGING OVER SASKATCHEWAN. BY THURSDAY MORNING...THE LOW WILL BE
IN THE VICINITY OF NORTHWEST MN/NORTHEAST NORTH DAKOTA HEADING
SOUTHEAST BRINGING A SURFACE LOW WITH IT. THIS WILL BEGIN TO
AFFECT THE AREA LATER THURSDAY NIGHT OR FRIDAY MORNING WITH
ANOTHER COOL FRONT DROPPING ACROSS THE AREA. AN UPPER TROUGH AXIS
LOOKS TO LAG THIS SYSTEM SO AT LEAST LOW PRECIP CHANCES WILL
LINGER INTO FRIDAY. SURFACE HIGH PRESSURE THEN ARRIVES INTO
SATURDAY MORNING AS UPPER RIDGING BECOMES RE-ESTABLISHED ACROSS
THE WESTERN U.S. A TROUGH MOVES THROUGH THE RIDGE SPAWNING SURFACE
LOW DEVELOPMENT ACROSS THE HIGH PLAINS LATER SATURDAY AND
SPREADING WARM ADVECTION EASTWARD ACROSS THE LOCAL AREA FOLLOWED
BY THE PASSAGE OF ANOTHER SURFACE LOW INTO MONDAY. THIS WHOLE
SYSTEM RESULTS IN CHANCES FOR SHOWERS AND STORMS FROM LATE SUNDAY
ON. TEMPS LOOK TO REMAIN MORE IN CHECK GIVEN PERIODIC CHANCES FOR
PRECIP...GENERALLY LOWER HEIGHTS OVER THE AREA AND OCCASIONAL
FRONTAL PASSAGES. DEPENDING ON FRONTAL TIMING THURSDAY...SOUTHERN
AREAS MAY REACH THE 90S...BUT OTHER THAN THAT WILL KEEP HIGHS IN
THE MID TO UPPER 80S FOR NOW.
MDB
&&
.CLIMATE...
400 AM CDT
RECORDS HIGHS FOR TODAY JULY 23RD ARE:
CHICAGO 99 /1914/
ROCKFORD 104 /1934/
RECORD WARM LOWS FOR TODAY JULY 23RD ARE:
CHICAGO 78 /1965/
ROCKFORD 76 /1965/
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* SHRA/TSRA EARLY-MID THIS MORNING.
* MVFR...POSSIBLY LOWER...VSBY IN TSRA THIS MORNING. POTENTIAL FOR MVFR
CIGS IN HEAVIER TSRA.
* TSRA TUESDAY AFTERNOON AND NIGHT.
* WIND TRENDS.
RC
//DISCUSSION...UPDATED 06Z...
FOCUS IN THE NEAR TERM IS NW TO SE ORIENTED CLUSTER OF SHRA/TSRA
EXTENDING INTO SE MN/SW WI. A COOL FRONT CONTINUES TO SLOWLY SAG
SOUTH THROUGH WISCONSIN AS WELL. RADAR TRENDS AND LATEST GUIDANCE
POINT TO MN/WI ACTIVITY HOLDING TOGETHER AND MOVING SOUTHEAST OVER
THE TERMINALS EARLY THROUGH MID THIS MORNING...ROUGHLY 9Z-13Z IN
RFD AREA AND 10Z-14Z IN ORD/MDW/DPA/GYY AREA. TIMING MAY NEED
REFINING IN 09Z UPDATE OR SOONER...BUT HAVE DECENT CONFIDENCE
THAT TERMINALS WILL SEE BOTH SHRA AND TSRA DUE TO LOW LEVEL JET
DIRECTING INTO AREA AND PLENTY OF ELEVATED INSTABILITY. THE FRONT
DROPPING SOUTH MAY ALSO PROVIDE A FOCUS FOR MAINTAINING THE
ACTIVITY. IT IS TOO EARLY TO TELL IF TSRA WILL DEVELOP
VARIABLE/GUSTY WINDS...THUS BIGGEST CONCERN IS AT LEAST TEMPORARY
MVFR VSBY IN TSRA AND POSSIBLY A FURTHER LOWERING OF CIGS THAN
INDICATED IN TAFS IN VERY MOIST AIRMASS. PRIOR TO ARRIVAL OF
SHRA/TSRA...CANNOT RULE OUT LIGHT SHRA BREAKING OUT...AND AM ALSO
CONCERNED ACTIVITY COULD LINGER LONGER SO CARRIED -SHRA TO 16/17Z
AT TAF SITES. WILL NEED TO MONITOR TRENDS. AFTER THE MORNING
ACTIVITY...THERE COULD BE ADDITIONAL SHRA/TSRA DURING THE
DAY...BUT NOT CONFIDENT ENOUGH FOR MENTION DURING THIS TIME. A
BETTER CHANCE MAY EXIST LATER IN THE EVENING AS THE FRONTAL
BOUNDARY LIFTS BACK NORTH. INDICATED PROB30 FOR TSRA IN RFD AND
ORD TAFS WITH THIS IN MIND.
WINDS CURRENTLY ARE VERY LIGHT OUT OF THE WEST WHERE THEY ARE NOT
COMPLETELY CALM AND SHOULD REMAIN FAIRLY LIGHT EVEN AS FRONT
PUSHES SOUTH THROUGH THE TERMINALS...TURNING WINDS NORTHEAST. WITH
SOME SITES NORTH OF MKE REPORTING SLIGHTLY STRONGER NORTHEAST
WINDS...WILL NEED TO WATCH FOR THIS OCCURRING AT ORD/MDW/GYY.
WINDS WILL STAY MORE NORTHEASTERLY AT THE EASTERN TAF SITES
BEFORE BECOMING EAST SOUTHEAST LATE TUESDAY EVENING. THE RFD AREA
IS LIKELY TO SEE WINDS EAST-NORTHEAST FOR A TIME AFTER THE FRONTAL
PASSAGE...BUT THEN BECOME EASTERLY BY LATE MORNING AND REMAIN SO
UNTIL POSSIBLY BECOMING MORE EAST-SOUTHEAST TOMORROW EVENING.
RC
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM/HIGH CONFIDENCE IN SHRA/TSRA OCCURRING AT TERMINALS EARLY
THROUGH MID THIS MORNING...LOW CONFIDENCE IN EXACT TIMING AND
DURATION.
* MEDIUM/HIGH CONFIDENCE IN AT LEAST TEMPO MVFR VSBY IN SHRA/TSRA
EARLY THROUGH MID THIS MORNING...LOW CONFIDENCE IN IFR VSBY AND
LOW CONFIDENCE IN MVFR CIGS.
* LOW CONFIDENCE IN TSRA THIS AFTERNOON AND LOW/MEDIUM CONFIDENCE
IN TSRA LATE THIS EVENING.
* MEDIUM CONFIDENCE IN WIND TRENDS...WITH LOW CONFIDENCE IN
NEEDING TO ADD GUSTS TO TSRA ACTIVITY THIS MORNING.
RC
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY THROUGH FRIDAY...CHANCES FOR OCCASIONAL TSRA...OTHERWISE
VFR.
SATURDAY...VFR.
SUNDAY...CHANCE FOR TSRA...ESPECIALLY LATE. OTHERWISE VFR.
RC
&&
.MARINE...
300 PM CDT
RATHER ACTIVE FORECAST PERIOD LIES AHEAD WITH THE FIRST OF SEVERAL
LOWS AND FRONTS AFFECTING THE LAKE THIS AFTERNOON. SURFACE LOW
PRESSURE HAS MOVES INTO CENTRAL QUEBEC AND WILL LIFT NORTHEASTWARD
WHILE DEEPENING AS IT REACHES NEWFOUNDLAND TUESDAY MORNING/EARLY
AFTERNOON. THE COLD FRONT ASSOCIATED WITH THIS LOW IS MAKING
SOUTHEASTWARD PROGRESS AND RUNS FROM NEAR THE STRAITS OF MACKINAC
SOUTHEASTWARD TO NEAR MANITOWOC AT 2 PM CDT. WINDS WILL TURN
NORTHERLY AS THE FRONT PASSES THROUGH THE EVENING. IT APPEARS THAT
THERE MAY BE A BRIEF PERIOD OF STRONGER WINDS FROM NEAR THE MANITOU
ISLANDS NORTHWARD TO THE STRAITS EARLY THIS EVENING BEHIND THE FRONT
WITH 25 KT GUSTS POSSIBLE BEFORE SETTLING DOWN. A SIMILAR INCREASE
IN SPEEDS MAY OCCUR EARLY TONIGHT ACROSS THE SOUTHERN PART OF THE
LAKE BEHIND THE FRONT. HIGH PRESSURE WILL APPROACH TUESDAY ALLOWING
WINDS TO DIMINISH WITH A NORTHEASTERLY DIRECTION IN PLACE.
ATTENTION THEN TURNS TO LOW PRESSURE DEVELOPING ACROSS
THE CENTRAL/NORTHERN PLAINS INTO WEDNESDAY. THIS LOW LOOKS TO
REACH THE LAKE WEDNESDAY EVENING BUT THE STRENGTH IS SOMEWHAT IN
QUESTION. SOME MODEL GUIDANCE CONTINUES TO REALLY DEEPEN IN AS IT
CROSSES THE LAKE BUT THIS STILL LOOKS OVERDONE. DO EXPECT A LOW
WITH A PRESSURE OF AROUND 29.5 INCHES...THOUGH IT COULD BE
STRONGER...TO CROSS THE CENTRAL PART OF THE LAKE. SOUTH WINDS WILL
INCREASE AHEAD OF THE LOW ACROSS THE SOUTHERN HALF OF THE LAKE
WEDNESDAY MORNING WHILE EAST OR NORTHEAST WINDS WILL OCCUR NORTH.
DEPENDING ON THE STRENGTH OF THE LOW WIND SPEEDS MAY NEED TO BE
INCREASED OVER CURRENT FORECAST VALUES. SHOULD A MUCH DEEPER
SCENARIO PAN OUT...WHICH AGAIN LOOKS TO BE A RATHER LOW
PROBABILITY...THEN GALES COULD DEVELOP. THE LOW THEN CLEARS TO THE
EAST THURSDAY MORNING LEAVING A WEAK PRESSURE GRADIENT BEHIND IT
BUT AHEAD OF A WEAKER LOW WHICH WILL CROSS THE LAKE FRIDAY
MORNING. HIGH PRESSURE WILL GRADUALLY BUILD ON SATURDAY.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS DES MOINES IA
645 PM CDT WED JUL 25 2012
.UPDATED FOR 26/00Z AVIATION DISCUSSION...
.SHORT TERM /TONIGHT/...
MAIN FORECAST CONCERN IS WITH TIMING OF COLD FRONT AND CONVECTION
POTENTIAL THIS EVENING INTO THE OVERNIGHT HOURS. NAM/RAP SEEM TO
HAVE A DECENT HANDLE ON INITIATION OF CONVECTION AND LEANED TOWARD
TIMING OF FRONT/POPS. THE 16Z HRRR HAS SOME ISOLATED CONVECTION
DEVELOPING B/T 22-00Z BUT THINKING CAP IS STILL TOO STRONG FOR MUCH
CONVECTION TO GET GOING UNTIL AFTER 00Z. REALLY CUT BACK ON POPS
UNTIL AFTER 00Z OVER THE CENTRAL AND SOUTHEAST CWA. THE 12Z 4.0KM
WRF MODEL RUNS FROM NSSL AND NCEP BOTH HAVE VERY SPOTTY PRECIP
THROUGH TONIGHT...AND SORT OF LIGHTS UP THE FRONT SOUTH OF
INTERSTATE 80 AFTER 02Z THURSDAY. HAVE LOW CONFIDENCE WITH ANY
WIDESPREAD SIGNIFICANT CONVECTION TONIGHT. MODELS FORECASTING PW
VALUES NEAR 2 INCHES GENERALLY ALONG THE FRONT...AND 1-1.5 INCHES
BEHIND IT. HOWEVER...WITH SUCH SPOTTY CONVECTION AND LOWERED QPF
AMOUNTS TO LESS THAN A HALF INCH THROUGHOUT THE FORECAST
AREA...ESPECIALLY WITH SUCH HIGH BASED CONVECTION. PLENTY OF SURFACE
BASED INSTABILITY...BUT LITTLE IF ANY EFFECTIVE SHEAR AVAILABLE...AS
WELL AS FORCING OTHER THAN THE FRONTAL BOUNDARY TONIGHT. THINKING
MAIN SEVERE THREAT WILL BE WINDS WITH THE DRY AIRMASS PRESENT.
.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
LARGE SCALE MAINLY POST FRONTAL FORCING SHOULD BE JUST EXITING
FORECAST AREA BY THE START OF THE PERIOD SO ANY LINGERING
PRECIP...IF ANY...SHOULD BE MOVING INTO MO AND IL. FORECAST DRY
AFTER 15Z. PREVIOUS FORECAST HAD LOW POPS BRUSHING NERN IA BY LATE
AFTERNOON BUT CANNOT REALLY FIND ANY SUPPORT FOR THIS WITH LIMITED
FORCING AND INSUFFICIENT MOISTURE...AND EVEN THAT LOOKS TO BE POST
00Z. UPSTREAM NRN PLAINS AIRMASS WILL GRADUALLY PASS THROUGH IA
DURING THE DAY BUT DEEP NW FLOW AND MIXING WILL STILL ALLOW
CENTRAL/SRN HIGHS TO REACH LOW/MID 90S BY AFTERNOON. DO NOT
ANTICIPATED ENOUGH PRECIP TONIGHT TO AFFECT THAT. BLEND OF SREF/NAM
SOUNDINGS SEEMS REASONABLE.
NRN PLAINS SURFACE RIDGE WILL RETURN IA TEMPS TO NORMAL FOR FRI WITH
CONTINUED DRY WEATHER AS GREAT LAKES SHORT WAVE DEPARTS. THIS WILL
BE FOLLOWED BY AN EXTENDED PERIOD OF ROCKIES AND HIGH PLAINS
RIDGING...RIGHT INTO WED AND BEYOND...LEAVING IA WITH WARM BUT NOT
EXTREME TEMPS AND LOW END PRECIP POTENTIAL. CHANCES INCREASE
SOMEWHAT THIS WEEKEND AS SHORT WAVE TOPS THE RIDGE INCREASING
FORCING...ESPECIALLY THERMODYNAMIC...BY SAT. THIS WEAK FORCING
LINGERS INTO SUN...AND POSSIBLY EARLY MON LEADING TO SEVERAL DAYS
WORTH OF CHANCE POPS. MODELS CONTINUE TO DABBLE IN WEAK QPF EVENTS
AFTER THIS TIME...BUT THERE IS REALLY NO CONSISTENT FORCING FEATURE
TO LATCH ONTO SO HAVE LEFT MON NIGHT-WED DRY AT THIS POINT.
REGARDING TEMPS..ONLY REAL CONCERN IS LOW CONFIDENCE FORECAST
SATURDAY. QUESTIONS ON HOW MUCH WE WILL MIX IN NEW REGIME WITH
LIGHT WINDS. HAVE PRETTY MUCH MIXED THINGS OUT TO 900-850MB OR
MORE...MIXING SEASONALLY...BUT FEEL NAM IS UNDERDONE WHICH SEEMS TO
BE THE CASE AT TIMES IN WEAK FLOW.
&&
.AVIATION...26/00Z
COLD FRONT PUSHING INTO THE STATE WITH STORMS DEVELOPING ALONG AND
BEHIND THE BOUNDARY. GENERALLY VFR CONDITIONS FORECAST BUT LOCAL
MVFR CONDITIONS IN STORMS POSSIBLE. STRONG WIND GUSTS LIKELY IN
STORMS ALONG WITH ONE INCH DIAMETER HAIL. WIND BEHIND THE FRONT
WILL SHIFT TO THE NW AT 15-25 KTS.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
EXCESSIVE HEAT WARNING UNTIL 7 PM CDT
ADAIR-ADAMS-APPANOOSE-AUDUBON-BOONE-CALHOUN-CARROLL-CASS-CLARKE-
CRAWFORD-DALLAS-DAVIS-DECATUR-GREENE-GUTHRIE-HAMILTON-JASPER-LUCAS-
MADISON-MAHASKA-MARION-MONROE-POLK-RINGGOLD-SAC-STORY-TAYLOR-UNION-
WAPELLO-WARREN-WAYNE-WEBSTER
HEAT ADVISORY UNTIL 7 PM CDT
BLACK HAWK-BREMER-BUTLER-FRANKLIN-GRUNDY-HARDIN-HUMBOLDT-MARSHALL-
POCAHONTAS-POWESHIEK-TAMA-WRIGHT
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...SMALL
AVIATION...FAB
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1155 PM CDT MON JUL 23 2012
...UPDATED AVIATION DISCUSSION...
.UPDATE /HEAT/...
FOR PUBLIC AWARENESS...HAVE DECIDED TO ISSUE A HEAT ADVISORY THROUGH
WEDNESDAY ON THE NORTH AND EAST SIDES OF THE EXISTING HEAT WARNING.
TWO DAYS HAVE ALREADY SEEN TEMPERATURES NEAR OR ABOVE 100...SOMEWHAT
WARMER THAN ANTICIPATED...AND NIGHTS WILL BE WARM. STILL SOME
UNCERTAINTY WHETHER SURFACE BOUNDARY...WHICH IS CURRENTLY RUNNING
FROM ALGONA TO NORTH OF WATERLOO...WILL SAG FARTHER SOUTH PER
SEVERAL NUMERICAL MODELS. HOWEVER...WITH 00Z SOUNDINGS NOT REALLY
FAVORABLE FOR CONVECTION IN IOWA AND CURRENT ACTIVITY DEVELOPING
WELL NORTH IN WESTERN MINNESOTA...IT APPEARS ANY BOUNDARY PUSH SOUTH
WILL NOT LAST TOO LONG. ANOTHER FACTOR CONSIDERED IS THAT DEWPOINTS
JUMP INTO 70S NORTH OF THAT BOUNDARY...PROVIDING LITTLE RELIEF.
WAITING TO SEE THE 00Z MODELS...BUT WEDNESDAY COULD BE HOTTEST YET
WITH A VERY WARM START IF BOUNDARY REMAINS NORTH.
.SHORT TERM /TONIGHT/...
MAIN FORECAST CONCERN IS POTENTIAL FOR CONVECTION ACROSS NORTHERN
IOWA TONIGHT. WEAK BOUNDARY EXTENDS ACROSS SOUTHERN MN COMBINED WITH
AN 500MB VORT MAX WILL BE THE FOCUS FOR THUNDERSTORMS LATER THIS
EVENING INTO TUESDAY MORNING.
NAM/SREF/RAP KEEP CONVECTION ALONG THE BORDER OVERNIGHT...4.0KM WRF
FROM NCEP HAS SOME ISOLATED CONVECTION ACROSS THE NORTHERN TWO TIERS
OF COUNTIES AND THE NSSL 4.0KM WRF IS SIMILAR. LATEST HRRR (17Z RUN)
IS MORE BULLISH IN BREAKING OUT CONVECTION THIS AFTERNOON INTO THE
EVENING AND SEEMS MORE WIDESPREAD THAN ANY OTHER MODEL. LEANED
TOWARD A BLEND OF THE NAM12/SREF WITH TIMING AND PLACEMENT OF
CONVECTION OVER NORTHERN IOWA PAST 03Z TUESDAY. WITH THE VERY DRY
AIR MASS IN THE LOWER LEVELS AND BUFR SOUNDINGS INDICATIVE OF MAINLY
WIND THREAT AS THEY MIX UP TO AROUND 850-700MB DEPENDING ON WHICH
MODEL...CANNOT RULE AN ISOLATED SEVERE POTENTIAL TONIGHT ACROSS
NORTHERN IOWA. EFFECTIVE SHEAR AROUND 35-40KTS BUT THERE IS
LITTLE...IF ANY...LOW LEVEL SHEAR WITH 0-1KM AND 0-3KM SHEAR LESS
THAN 15KTS AND 30KTS RESPECTIVELY. THERE IS PLENTY OF INSTABILITY
PRESENT BUT WITH SUCH A STRONG CAP IN PLACE...IT WILL TAKE SOME TIME
FOR IT ERODE. WITH THE UPPER LEVEL VORT MAX TIMING TO MOVE INTO
NORTHERN IOWA AFTER 03Z...HAVE HIGHEST POPS B/T 06-12Z TUESDAY.
.LONG TERM /TUESDAY THROUGH MONDAY/...
THERE IS LITTLE CHANGE NEEDED TO THE GOING FORECAST. IT WILL REMAIN
HOT THROUGH WEDNESDAY WITH CHANCES FOR SHOWERS/THUNDERSTORMS ACROSS
THE NORTHEAST AND EAST. SOUNDING ARE SHOWING SOME DRY AIR ALOFT AND
A CLASSIC INVERTED V SO THERE IS SOME POTENTIAL FOR STRONG/DAMAGING
WIND WITH THESE STORMS AND THAT IS COVERED IN VARIOUS OUTLOOKS. THE
MODELS ARE A LITTLE SLOWER IN BRINGING THE FRONT THROUGH SO
WEDNESDAY HIGHS MAY NEED TO BE BROUGHT UP BUT I WOULD LIKE TO SEE
WHAT CLOUDS/CONVECTIVE TRENDS WILL DO BEFORE RAISING THEM MORE THAN
I HAVE DONE. SOMETHING ELSE OF NOTE THAT MAY BE A CAVEAT TO THE
SEVERE POTENTIAL IS THAT THE MODELS HAD BEEN ADVERTISING A VORT MAX
TO DROP DOWN THE RIDGE ACROSS THE EAT/NORTHEAST AND NOW THEY ARE
TAKING THAT VORT MAX EAST AND NOT DROPPING IT SOUTH. QPF IS ALSO
LESS NOW FOR THE AREA WHICH IS NOT A SURPRISE REALLY. OTHER THINGS
OF NOTE IS THAT A SHORTWAVE THAT WAS PROGGED FOR SATURDAY NIGHT IS
NOW COMING THROUGH ON SUNDAY. THIS IS ADVERTISED BY BOTH THE GFS
AND EURO SO I LEFT SATURDAY DRY AND INCREASED POPS ON SUNDAY. TEMPS
WILL STILL BE SEASONAL BUT COMPARED TO WHAT WE HAVE THE TERM
"COOLER" CAN BE APPLIED HERE AND IT WILL IN DEED FEEL THAT WAY.
HIGHS FOR THE WEEKEND WILL BE IN THE LOWER TO MID 80S WITH MAYBE
SOME 90S ACROSS THE FAR SOUTHWEST.
THE COOLER TEMPS DO NOT APPEAR TO BE STAYING AS WAS ELUDED TO
YESTERDAY...THE MODELS REBUILD THE RIDGE OVER THE ROCKIES AND TRENDS
ARE TO BRING THE UPPER RIDGE BACK INTO THE MIDWEST. THIS WILL OCCUR
BEYOND THE EXTENDED PERIOD SO JUST HOW MUCH HEAT WE WILL SEE IS
STILL GOING TO NEED TO BE EVALUATED. WE WILL AT LEAST SEE A SEVERAL
DAY BREAK FROM THE OPPRESSIVE HEAT LATER THIS WEEK.
&&
.AVIATION...24/00Z
STILL DOES NOT APPEAR LIKELY THAT MINNESOTA THUNDERSTORMS WILL
AFFECT IOWA...BUT THERE MAY BE SOME VERY HIGH BASED SHOWERS OR
THUNDER THAT BRUSH BY KMCW LATE TONIGHT. OTHERWISE EXPECTING VFR
CONDITIONS THROUGHOUT THE TAF FORECAST. SURFACE BOUNDARY HAS SAGGED
SOUTH OF KMCW/KALO FOR THE OVERNIGHT...POSSIBLY REINFORCED BY
OUTFLOW FROM STORMS FAR TO THE NORTH. IT WILL RETURN DURING THE DAY
TUESDAY WITH SOUTH FLOW.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
EXCESSIVE HEAT WARNING UNTIL 7 PM CDT WEDNESDAY FOR ADAIR-ADAMS-
APPANOOSE-AUDUBON-BOONE-CALHOUN-CARROLL-CASS-CLARKE-CRAWFORD-
DALLAS-DAVIS-DECATUR-GREENE-GUTHRIE-HAMILTON-JASPER-LUCAS-
MADISON-MAHASKA-MARION-MONROE-POLK-RINGGOLD-SAC-STORY-TAYLOR-
UNION-WAPELLO-WARREN-WAYNE-WEBSTER.
HEAT ADVISORY UNTIL 7 PM CDT WEDNESDAY FOR BLACK HAWK-BREMER-
BUTLER-FRANKLIN-GRUNDY-HARDIN-HUMBOLDT-MARSHALL-POCAHONTAS-POWESHIEK-
TAMA-WRIGHT.
&&
$$
UPDATE...JUNGBLUTH
LONG TERM...FAB
SHORT TERM...PODRAZIK
AVIATION...JUNGBLUTH
AREA FORECAST DISCUSSION
NWS GOODLAND KS
744 PM MDT WED JUL 25 2012
.UPDATE...
ISSUED AT 740 PM MDT WED JUL 25 2012
HAVE TRIMMED PRECIP. CHANCES BACK BASED ON THE RADAR TRENDS FROM
THE PAST HOUR OR SO. WITH COLD FRONT ALREADY SOUTHEAST OF THE
AREA...AM THINKING ANY LINGERING PRECIP. WILL BE OVER THE WEST AND
NORTH WHERE AN UPPER LEVEL SHORT WAVE TROUGH IS MOVING ACROSS THE
AREA. AM THINKING THESE SHOWERS/THUNDERSTORMS SHOULD DIMINISH OVER
THE NEXT COUPLE OF HOURS AS DAY TIME HEATING IS LOST. WINDS SHOULD
CONTINUE TO DECLINE AS THE COLD FRONT MOVES OUT OF THE AREA AND
MIXING DECLINES.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH TONIGHT)
ISSUED AT 1241 PM MDT WED JUL 25 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW SHORTWAVE TROUGH AXIS
CURRENTLY EXTENDING ACROSS NEBRASKA PANHANDLE SOUTH ALONG KS/CO
STATE LINE...AND THEN ACROSS OK/TX PANHANDLE. WV IMAGERY SHOWS
PLUME OF MID LEVEL MOISTURE EXTENDING NORTH ON LEE SIDE OF ROCKIES
ALONG WESTERN EDGE OF TROUGH AXIS. ANOTHER SHORTWAVE TROUGH IS
CURRENTLY OVER CENTRAL WY AND SHOULD MOVE EAST INTO NEBRASKA BY
THIS EVENING. AT THE SURFACE THE COLD FRONT HAS STALLED JUST
SOUTHEAST OF OUR CWA. CLOUD COVER AND CONVECTION HAVE BEEN SLOW TO
DEVELOP MUCH FURTHER SOUTH THAN THE EXTREME NW PART OF CWA.
AS THE SHORTWAVE OVER CENTRAL WY MOVES EAST GUIDANCE CONTINUES TO
SHOW LARGE SCALE ASCENT INCREASING ACROSS THE EASTERN HALF OF THE
CWA IN PROXIMITY OF FRONT. AT THIS TIME LATEST HRRR AND RUC WOULD
SUPPORT SCATTERED THUNDERSTORMS FORMING GENERALLY EAST OF GOODLAND
AND THEN INCREASING IN COVERAGE THROUGH 00Z AS THEY MOVE
EASTWARD...QUICKLY ENDING OVER OUR CWA THIS EVENING. NAM CONTINUES
TO SHOW ISOLATED ACTIVITY FURTHER WEST ASSOCIATED WITH ELEVATED
CAPE AND H7 FRONTOGENESIS THROUGH THE OVERNIGHT PERIOD. CONFIDENCE
IS STILL TOO LOW TO INCLUDE ANY THUNDERSTORMS BEYOND THIS EVENING
WITH LARGE SCALE SUBSIDENCE AND SURFACE HIGH PRESSURE QUICKLY
BUILDING OVER THE CWA. I LEFT PATCHY FOG MENTION IN FORECAST OVER
EASTERN LOCATIONS...WITH CLAM WINDS AND STABLE AIR MASS SUPPORTING
RADIATIVE FOG DEVELOPMENT. GUIDANCE REALLY HAS NOT PICKED UP ON THIS
YET...SO I HAVE LEFT FOG COVERAGE LIMITED TO PATCHY.
.LONG TERM...(THURSDAY THROUGH WEDNESDAY)
ISSUED AT 246 PM MDT WED JUL 25 2012
HIGH PRESSURE MOVES INTO THE PLAINS STATES AT THE SURFACE THURSDAY
AND FRIDAY AS THE UPPER RIDGE AMPLIFIES OVER THE INTERMOUNTAIN
WEST AND MOVES EAST OVER THE ROCKIES. PRECIPITATION CHANCES ARE
MINIMAL ON THURSDAY AND THURSDAY NIGHT AS A RESULT. BY FRIDAY
EVENING THE SURFACE HIGH MOVES FAR ENOUGH TO THE EAST WITH A LEE
TROUGH DEEPENING IN THE VICINITY OF THE FAR EASTERN COLORADO
BORDER TO FORM A CONVERGENCE AREA OVER THE WESTERN PORTION OF THE
FORECAST AREA AS A SHORT WAVE TROUGH IN THE UPPER LEVEL FLOW MOVES
OVER THROUGH THE TOP OF THE RIDGE AND CLIPS THE NORTHERN SECTIONS
OF THE FORECAST AREA FRIDAY NIGHT. THIS SETUP WILL BRING A BETTER
CHANCE OF THUNDERSTORMS FRIDAY AFTERNOON AND EVENING. SEVERAL
ADDITIONAL SHORT WAVE TROUGHS MAKE THEIR WAY AROUND THE UPPER
RIDGE AND CLIP THE FORECAST AREA FROM SATURDAY THROUGH TUESDAY.
WITH A SURFACE TROUGH ALSO REMAINING OVER MAINLY THE WESTERN
PORTION OF THE FORECAST AREA DURING THIS TIME...THEREFORE EXPECT
TEMPERATURES TO REMAIN VERY WARM WITH ADDITIONAL DIURNALLY DRIVEN
ISOLATED TO SCATTERED THUNDERSTORMS MAINLY OVER THE WESTERN
PORTIONS OF THE FORECAST AREA. BY THE MIDDLE OF NEXT
WEEK...CURRENT INDICATIONS ARE THAT THE UPPER RIDGE WILL AMPLIFY
FURTHER AND MOVE MORE OVER THE PLAINS STATES...SENDING THE SHORT
WAVE IMPULSES FURTHER NORTH THROUGH THE NORTHERN PLAINS AND
POSSIBLY DECREASING THE POSSIBILITY OF PRECIPITATION ACROSS THE
CENTRAL HIGH PLAINS REGION.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 508 PM MDT WED JUL 25 2012
VFR CONDITIONS ARE FORECAST FOR THE 0Z TAFS. COLD FRONT CURRENTLY
RUNNING FROM JUST WEST OF NORTON SOUTHWEST TO NEAR RUSSELL SPRINGS
WILL DRIFT EAST QUITE SLOWLY FOR THE NEXT COUPLE OF HOURS. MEANWHILE AN
UPPER LEVEL SHORT WAVE TROUGH CURRENTLY SPARKING SCATTERED STORMS
OVER EASTERN COLORADO WILL MOVE THROUGH THE TRI- STATE AREA OVER THE
NEXT COUPLE OF HOURS...POSSIBLY BRINGING SOME ISOLATED TO
SCATTERED STORMS WITH IT. WILL LEAVE A VCTS MENTION IN THE TAFS
BUT WILL NOT INCLUDE A TEMPO GROUP AS AM NOT CONFIDENT ENOUGH THAT
STORMS WILL MOVE OVER ANY OF THE TAF SITES. THE UPPER LEVEL TROUGH
WILL MOVE OUT OF THE AREA DURING THE MID TO LATE EVENING BRINGING
PRECIP. CHANCES TO AN END.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...LOCKHART
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
508 PM MDT WED JUL 25 2012
.SHORT TERM...(THIS AFTERNOON THROUGH TONIGHT)
ISSUED AT 1241 PM MDT WED JUL 25 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW SHORTWAVE TROUGH AXIS
CURRENTLY EXTENDING ACROSS NEBRASKA PANHANDLE SOUTH ALONG KS/CO
STATE LINE...AND THEN ACROSS OK/TX PANHANDLE. WV IMAGERY SHOWS
PLUME OF MID LEVEL MOISTURE EXTENDING NORTH ON LEE SIDE OF ROCKIES
ALONG WESTERN EDGE OF TROUGH AXIS. ANOTHER SHORTWAVE TROUGH IS
CURRENTLY OVER CENTRAL WY AND SHOULD MOVE EAST INTO NEBRASKA BY
THIS EVENING. AT THE SURFACE THE COLD FRONT HAS STALLED JUST
SOUTHEAST OF OUR CWA. CLOUD COVER AND CONVECTION HAVE BEEN SLOW TO
DEVELOP MUCH FURTHER SOUTH THAN THE EXTREME NW PART OF CWA.
AS THE SHORTWAVE OVER CENTRAL WY MOVES EAST GUIDANCE CONTINUES TO
SHOW LARGE SCALE ASCENT INCREASING ACROSS THE EASTERN HALF OF THE
CWA IN PROXIMITY OF FRONT. AT THIS TIME LATEST HRRR AND RUC WOULD
SUPPORT SCATTERED THUNDERSTORMS FORMING GENERALLY EAST OF GOODLAND
AND THEN INCREASING IN COVERAGE THROUGH 00Z AS THEY MOVE
EASTWARD...QUICKLY ENDING OVER OUR CWA THIS EVENING. NAM CONTINUES
TO SHOW ISOLATED ACTIVITY FURTHER WEST ASSOCIATED WITH ELEVATED
CAPE AND H7 FRONTOGENESIS THROUGH THE OVERNIGHT PERIOD. CONFIDENCE
IS STILL TOO LOW TO INCLUDE ANY THUNDERSTORMS BEYOND THIS EVENING
WITH LARGE SCALE SUBSIDENCE AND SURFACE HIGH PRESSURE QUICKLY
BUILDING OVER THE CWA. I LEFT PATCHY FOG MENTION IN FORECAST OVER
EASTERN LOCATIONS...WITH CLAM WINDS AND STABLE AIR MASS SUPPORTING
RADIATIVE FOG DEVELOPMENT. GUIDANCE REALLY HAS NOT PICKED UP ON THIS
YET...SO I HAVE LEFT FOG COVERAGE LIMITED TO PATCHY.
.LONG TERM...(THURSDAY THROUGH WEDNESDAY)
ISSUED AT 246 PM MDT WED JUL 25 2012
HIGH PRESSURE MOVES INTO THE PLAINS STATES AT THE SURFACE THURSDAY
AND FRIDAY AS THE UPPER RIDGE AMPLIFIES OVER THE INTERMOUNTAIN
WEST AND MOVES EAST OVER THE ROCKIES. PRECIPITATION CHANCES ARE
MINIMAL ON THURSDAY AND THURSDAY NIGHT AS A RESULT. BY FRIDAY
EVENING THE SURFACE HIGH MOVES FAR ENOUGH TO THE EAST WITH A LEE
TROUGH DEEPENING IN THE VICINITY OF THE FAR EASTERN COLORADO
BORDER TO FORM A CONVERGENCE AREA OVER THE WESTERN PORTION OF THE
FORECAST AREA AS A SHORT WAVE TROUGH IN THE UPPER LEVEL FLOW MOVES
OVER THROUGH THE TOP OF THE RIDGE AND CLIPS THE NORTHERN SECTIONS
OF THE FORECAST AREA FRIDAY NIGHT. THIS SETUP WILL BRING A BETTER
CHANCE OF THUNDERSTORMS FRIDAY AFTERNOON AND EVENING. SEVERAL
ADDITIONAL SHORT WAVE TROUGHS MAKE THEIR WAY AROUND THE UPPER
RIDGE AND CLIP THE FORECAST AREA FROM SATURDAY THROUGH TUESDAY.
WITH A SURFACE TROUGH ALSO REMAINING OVER MAINLY THE WESTERN
PORTION OF THE FORECAST AREA DURING THIS TIME...THEREFORE EXPECT
TEMPERATURES TO REMAIN VERY WARM WITH ADDITIONAL DIURNALLY DRIVEN
ISOLATED TO SCATTERED THUNDERSTORMS MAINLY OVER THE WESTERN
PORTIONS OF THE FORECAST AREA. BY THE MIDDLE OF NEXT
WEEK...CURRENT INDICATIONS ARE THAT THE UPPER RIDGE WILL AMPLIFY
FURTHER AND MOVE MORE OVER THE PLAINS STATES...SENDING THE SHORT
WAVE IMPULSES FURTHER NORTH THROUGH THE NORTHERN PLAINS AND
POSSIBLY DECREASING THE POSSIBILITY OF PRECIPITATION ACROSS THE
CENTRAL HIGH PLAINS REGION.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 508 PM MDT WED JUL 25 2012
VFR CONDITIONS ARE FORECAST FOR THE 0Z TAFS. COLD FRONT CURRENTLY
RUNNING FROM JUST WEST OF NORTON SOUTHWEST TO NEAR RUSSELL SPRINGS
WILL DRIFT EAST QUITE SLOWLY FOR THE NEXT COUPLE OF HOURS. MEANWHILE AN
UPPER LEVEL SHORT WAVE TROUGH CURRENTLY SPARKING SCATTERED STORMS
OVER EASTERN COLORADO WILL MOVE THROUGH THE TRI- STATE AREA OVER THE
NEXT COUPLE OF HOURS...POSSIBLY BRINGING SOME ISOLATED TO
SCATTERED STORMS WITH IT. WILL LEAVE A VCTS MENTION IN THE TAFS
BUT WILL NOT INCLUDE A TEMPO GROUP AS AM NOT CONFIDENT ENOUGH THAT
STORMS WILL MOVE OVER ANY OF THE TAF SITES. THE UPPER LEVEL TROUGH
WILL MOVE OUT OF THE AREA DURING THE MID TO LATE EVENING BRINGING
PRECIP. CHANCES TO AN END.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...LOCKHART
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
324 PM CDT TUE JUL 24 2012
.SYNOPSIS...
ISSUED AT 112 AM CDT TUE JUL 24 2012
A FAIRLY IMPRESSIVE UPPER LOW BY MID-SUMMER STANDARDS WAS CENTERED
OVER SOUTHERN ALBERTA AS OF 24.05Z WITH A COMPACT 70-80 KNOT JET
STREAK ON THE SOUTHEAST SIDE OF THE LOW AT 400MB (PER RAP ANALYSIS).
THERE WAS ANOTHER DEPARTING MID-UPPER LEVEL TROUGH ACROSS
SOUTHEASTERN CANADA TO THE NORTHERN GREAT LAKES REGION. IN THE
LOWER TROPOSPHERE...A FRONT WAS EVIDENT IN THE 850MB ANALYSIS
EXTENDING FROM LOWER MICHIGAN TO SOUTHERN MINNESOTA. THE FRONT
CONTINUED WEST TOWARD JUST SOUTH OF THE BLACK HILLS REGION WHICH
COULD BE FOLLOWED BACK NORTHWEST INTO CENTRAL/EASTERN MONTANA.
FAIRLY STRONG COLD FRONTOGENESIS WAS BECOMING INCREASINGLY EVIDENT
ACROSS WESTERN MONTANA WITH 850MB TEMPERATURES BEHIND THE COLD FRONT
IN WASHINGTON STATE FROM +6 TO +11C. THE HOTTEST TEMPERATURES AT
850MB WERE FOUND ALONG A LINE FROM ROUGHLY THE NEBRASKA PANHANDLE TO
SOUTHEASTERN SOUTH DAKOTA WHERE TEMPS RANGED FROM +30 TO +33C ALONG
THIS AXIS. WITHIN THIS HEAT AXIS...VALENTINE NEBRASKA REACHED A HIGH
TEMPERATURE OF 109F.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 406 AM CDT TUE JUL 24 2012
AS THE STRONG, COMPACT UPPER LOW MOVES EAST ACROSS THE CANADIAN
PRAIRIES TODAY...THE COLD FRONT TIED TO THIS UPPER FEATURE WILL MOVE
SOUTH DOWN THE NORTHERN HIGH PLAINS TODAY AND TONIGHT. AS THIS IS
HAPPENING...THE LEE TROUGH OVER EASTERN COLORADO WILL FURTHER
DEEPEN AS WELL RESULTING IN INCREASED PRESSURE GRADIENT AND STRONGER
SURFACE WINDS. 18 TO 22 KT SURFACE WINDS ARE FORECAST ACROSS
SOUTHWEST KANSAS FROM THE SOUTH-SOUTHWEST. HIGHS WILL BE SIMILAR TO
THAT OF THE PAST FEW DAYS...WITH WARMEST TEMPERATURES FARTHER NORTH
WHERE THE LOW LEVEL THERMAL NOSE WILL ADVANCE FARTHER EAST IN
NORTHWEST KANSAS SUPPORTING 105 TO 107 DEGREE LATE AFTERNOON
TEMPERATURES. ELSEWHERE SOUTH OF A SCOTT CITY TO HAYS LINE HIGHS
WILL RANGE FROM 100 TO 103F. TONIGHT...THE PRESSURE GRADIENT WILL
STILL BE STRONG ENOUGH TO KEEP WINDS UP IN THE 10-15 KNOT RANGE
THROUGH THE NIGHT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 320 PM CDT TUE JUL 24 2012
AN UPPER LEVEL SHORTWAVE TROUGH AND ASSOCIATED COOL FRONT WILL BE
MOVING ACROSS THE NORTHERN AND CENTRAL PLAINS ON WEDNESDAY NIGHT.
WITH GOOD SURFACE MOISTURE CONVERGENCE, CAPES AROUND 2000 J/KG, AND
LAYER PRECIPITABLE WATER RUNNING AROUND 125 PERCENT OF NORMAL WILL
MAINTAIN 30 TO 40 POPS ON WEDNESDAY NIGHT. WITH WEAK WINDS ALOFT AND
SLOW STORM MOVEMENT ANY STORMS THAT DEVELOP WILL BE CAPABLE OF BRIEF
HEAVY DOWNPOURS AND STRONG WIND GUSTS. THE GFS OPERATIONAL RUN
HOWEVER HAS LITTLE IF ANY MEASURABLE RAINFALL WHILE THE NAM LOOKS
MUCH MORE REASONABLE WITH QPF AND POP CHANCES. AFTER THE PASSAGE OF
THE UPPER LEVEL SHORTWAVE TROUGH THE UPPER RIDGE BUILDS BACK INTO
THE PLAINS INTO EARLY NEXT WEEK WITH HOT TEMPERATURES RETURNING.
OVERNIGHT LOWS ARE EXPECTED TO BE MILD FROM 68 TO 75 THROUGH THE
PERIOD. WE WILL HAVE A SMALL BREAK IN THE HEAT ON THURSDAY WITH THE
PASSAGE OF THE COOL FRONT WITH HIGHS IN THE MID 90S. HIGH TEMPS THEN
WARM TO NEAR THE CENTURY MARK ON FRIDAY, AND FROM 100 TO 105 INTO
THE WEEKEND AND INTO EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1257 PM CDT TUE JUL 24 2012
A SURFACE TROUGH WILL PERSIST IN THE LEE OF THE ROCKIES THROUGH
THE TAF PERIOD, CAUSING SOUTH WINDS AT 10 TO 20 KTS. A COLD FRONT
WILL APPROACH THE TAF SITES AFTER 18Z WEDNESDAY, RESULTING IN
THUNDERSTORM CHANCES AFTER THE TAF VALID PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 75 104 70 96 / 10 30 30 10
GCK 72 103 68 95 / 10 30 40 10
EHA 71 102 68 93 / 20 30 30 20
LBL 72 104 69 95 / 20 30 30 20
HYS 75 104 69 95 / 10 30 30 10
P28 77 103 74 98 / 10 10 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 8 PM CDT THIS EVENING FOR KSZ043-044-062-
063-074-075-084.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...UMSCHEID
LONG TERM...KRUSE
AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
107 PM CDT TUE JUL 24 2012
...UPDATED FOR AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 112 AM CDT TUE JUL 24 2012
A FAIRLY IMPRESSIVE UPPER LOW BY MID-SUMMER STANDARDS WAS CENTERED
OVER SOUTHERN ALBERTA AS OF 24.05Z WITH A COMPACT 70-80 KNOT JET
STREAK ON THE SOUTHEAST SIDE OF THE LOW AT 400MB (PER RAP ANALYSIS).
THERE WAS ANOTHER DEPARTING MID-UPPER LEVEL TROUGH ACROSS
SOUTHEASTERN CANADA TO THE NORTHERN GREAT LAKES REGION. IN THE
LOWER TROPOSPHERE...A FRONT WAS EVIDENT IN THE 850MB ANALYSIS
EXTENDING FROM LOWER MICHIGAN TO SOUTHERN MINNESOTA. THE FRONT
CONTINUED WEST TOWARD JUST SOUTH OF THE BLACK HILLS REGION WHICH
COULD BE FOLLOWED BACK NORTHWEST INTO CENTRAL/EASTERN MONTANA.
FAIRLY STRONG COLD FRONTOGENESIS WAS BECOMING INCREASINGLY EVIDENT
ACROSS WESTERN MONTANA WITH 850MB TEMPERATURES BEHIND THE COLD FRONT
IN WASHINGTON STATE FROM +6 TO +11C. THE HOTTEST TEMPERATURES AT
850MB WERE FOUND ALONG A LINE FROM ROUGHLY THE NEBRASKA PANHANDLE TO
SOUTHEASTERN SOUTH DAKOTA WHERE TEMPS RANGED FROM +30 TO +33C ALONG
THIS AXIS. WITHIN THIS HEAT AXIS...VALENTINE NEBRASKA REACHED A HIGH
TEMPERATURE OF 109F.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 406 AM CDT TUE JUL 24 2012
AS THE STRONG, COMPACT UPPER LOW MOVES EAST ACROSS THE CANADIAN
PRAIRIES TODAY...THE COLD FRONT TIED TO THIS UPPER FEATURE WILL MOVE
SOUTH DOWN THE NORTHERN HIGH PLAINS TODAY AND TONIGHT. AS THIS IS
HAPPENING...THE LEE TROUGH OVER EASTERN COLORADO WILL FURTHER
DEEPEN AS WELL RESULTING IN INCREASED PRESSURE GRADIENT AND STRONGER
SURFACE WINDS. 18 TO 22 KT SURFACE WINDS ARE FORECAST ACROSS
SOUTHWEST KANSAS FROM THE SOUTH-SOUTHWEST. HIGHS WILL BE SIMILAR TO
THAT OF THE PAST FEW DAYS...WITH WARMEST TEMPERATURES FARTHER NORTH
WHERE THE LOW LEVEL THERMAL NOSE WILL ADVANCE FARTHER EAST IN
NORTHWEST KANSAS SUPPORTING 105 TO 107 DEGREE LATE AFTERNOON
TEMPERATURES. ELSEWHERE SOUTH OF A SCOTT CITY TO HAYS LINE HIGHS
WILL RANGE FROM 100 TO 103F. TONIGHT...THE PRESSURE GRADIENT WILL
STILL BE STRONG ENOUGH TO KEEP WINDS UP IN THE 10-15 KNOT RANGE
THROUGH THE NIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 406 AM CDT TUE JUL 24 2012
MEDIUM RANGE MODELS INDICATE AN UPPER LEVEL SHORTWAVE TROUGH OF LOW
PRESSURE EJECTING EASTWARD OUT OF THE CENTRAL AND SOUTHERN ROCKIES
INTO THE WESTERN HIGH PLAINS WEDNESDAY BRINGING A MUCH NEEDED CHANCE
FOR PRECIP TO PORTIONS OF WESTERN KANSAS. AN ATTENDANT COLD FRONT IS
PROJECTED TO PUSH SOUTHEAST INTO WESTERN KANSAS SOMETIME BY EARLY TO
MID AFTERNOON WEDNESDAY SETTING THE STAGE FOR POSSIBLE SHOWER AND
THUNDERSTORM DEVELOPMENT. AS THE FRONT BEGINS TO PUSH INTO THE STATE,
THE NAM, GEM, GFS, AND ECMWF POINT TO A SURFACE LOW DEVELOPING ALONG
THE FRONT, GENERALLY ACROSS SOUTHWEST KANSAS. THIS WILL INCREASE LOW
LEVEL FORCING, PARTICULARLY TO THE NORTH AND EAST OF THE SURFACE LOW
ALONG THE BOUNDARY ITSELF. AMPLE MOISTURE WILL BE ON HAND AS A
PREVAILING LOW LEVEL SOUTHERLY FLOW IS EXPECTED TO DRIVE IT NORTH
WITH H85 DEWPOINTS JUST ABOVE 10C ACROSS MUCH OF CENTRAL AND WESTERN
KANSAS. ADDITIONALLY, NAM AND GFS MODEL SOUNDINGS DO POINT TO PLENTY
OF AVAILABLE MID/UPPER LEVEL INSTABILITY BY WEDNESDAY AFTERNOON WITH
CAPE VALUES IN EXCESS OF 1500 TO 2000 J/KG. HOWEVER, A COUPLE OF
FACTORS MAY LIMIT CONVECTION ACROSS WESTERN KANSAS AS THE FRONTAL
BOUNDARY BEGINS TO PUSH INTO THE AREA. FIRST WILL BE AN EXPECTED
WEAK FLOW ALOFT AS ALL MODELS KEEP THE UPPER LEVEL JET JUST OFF TO
OUR NORTH ACROSS THE NORTHERN PLAINS. CAPPING COULD ALSO PLAY A
LIMITING FACTOR AS A HOT AFTERNOON THE PREVIOUS DAY WILL HAVE HIGH
TEMPERATURES UP NEAR TO JUST ABOVE 100F.
BECAUSE OF THE WEAK FLOW ALOFT AND THE LIKELY LOCATION OF THE
DEVELOPING SURFACE LOW, WILL KEEP 30 POPS IN ACROSS MUCH OF THE AREA
WITH 40 POPS FURTHER NORTHEAST IN CENTRAL KANSAS, ALONG WHERE THE
BOUNDARY IS EXPECTED TO BE LATE WEDNESDAY. ANY DEVELOPING STORMS ARE
ALSO EXPECTED TO BE ELEVATED WITH STRONG OUTFLOW WINDS THE PRIMARY
THREAT. DRIER CONDITIONS ARE EXPECTED THROUGH THE REMAINDER OF THE
PERIOD AS UPPER LEVEL RIDGING REDEVELOPS ACROSS THE INTERMOUNTAIN
WEST BY THURSDAY AND PUSHES SLOWLY EAST INTO THE WESTERN HIGH PLAINS
THROUGH THE WEEKEND.
TEMPERATURES ARE EXPECTED TO BE ABOVE NORMAL WEDNESDAY EVEN AS THE
COLD FRONT BEGINS TO PUSH SOUTHEAST INTO WESTERN KANSAS BY MID DAY.
AHEAD OF THE COLD FRONT, THE NAM, GFS, AND ECMWF SHOW H85
TEMPERATURES RANGING FROM THE UPPER 20S(C) ACROSS CENTRAL KANSAS
TO JUST ABOVE 30C ACROSS MUCH OF SOUTHWEST KANSAS. CONSIDERING HOW
SLOW THE MODELS HAVE THE FRONT PROJECTED TO MOVE THROUGH THE AREA,
LOOK FOR HIGHS ABOVE 100F ACROSS CENTRAL AND MUCH OF SOUTHWEST
KANSAS AGAIN WEDNESDAY AFTERNOON. HOWEVER, A BRIEF REPRIEVE FROM
TRIPLE DIGIT HIGHS IS LIKELY THURSDAY IN WAKE OF THE SLOW MOVING
COLD FRONT. A NORTH TO NORTHEAST LOW LEVEL FLOW INTO WESTERN KANSAS
WILL HELP LOWER H85 TEMPERATURES BY JUST A FEW DEGREES. EVEN SO,
EXPECT HIGHS ONLY UP INTO THE 90S(F) THURSDAY AFTERNOON. A GRADUAL
WARMING TREND IS THEN EXPECTED AGAIN AS THE AFOREMENTIONED UPPER
LEVEL RIDGING DEVELOPS ACROSS THE INTERMOUNTAIN WEST BY THURSDAY AND
BEGINS TO PUSH EAST INTO THE WESTERN HIGH PLAINS THROUGH THE WEEKEND.
SHOULD SEE HIGHS CLIMBING BACK TO JUST ABOVE 100F BY THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1257 PM CDT TUE JUL 24 2012
A SURFACE TROUGH WILL PERSIST IN THE LEE OF THE ROCKIES THROUGH
THE TAF PERIOD, CAUSING SOUTH WINDS AT 10 TO 20 KTS. A COLD FRONT
WILL APPROACH THE TAF SITES AFTER 18Z WEDNESDAY, RESULTING IN
THUNDERSTORM CHANCES AFTER THE TAF VALID PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 104 75 106 69 / 10 10 30 30
GCK 105 72 105 68 / 10 10 30 20
EHA 101 71 104 66 / 20 20 30 20
LBL 102 72 106 69 / 20 20 30 20
HYS 106 75 106 69 / 0 10 30 20
P28 104 77 105 72 / 10 10 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 8 PM CDT THIS EVENING FOR KSZ043-044-062-
063-074-075-084.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...UMSCHEID
LONG TERM...JJOHNSON
AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
605 AM CDT TUE JUL 24 2012
...UPDATE TO AVIATION...
.SYNOPSIS...
ISSUED AT 112 AM CDT TUE JUL 24 2012
A FAIRLY IMPRESSIVE UPPER LOW BY MID-SUMMER STANDARDS WAS CENTERED
OVER SOUTHERN ALBERTA AS OF 24.05Z WITH A COMPACT 70-80 KNOT JET
STREAK ON THE SOUTHEAST SIDE OF THE LOW AT 400MB (PER RAP ANALYSIS).
THERE WAS ANOTHER DEPARTING MID-UPPER LEVEL TROUGH ACROSS
SOUTHEASTERN CANADA TO THE NORTHERN GREAT LAKES REGION. IN THE
LOWER TROPOSPHERE...A FRONT WAS EVIDENT IN THE 850MB ANALYSIS
EXTENDING FROM LOWER MICHIGAN TO SOUTHERN MINNESOTA. THE FRONT
CONTINUED WEST TOWARD JUST SOUTH OF THE BLACK HILLS REGION WHICH
COULD BE FOLLOWED BACK NORTHWEST INTO CENTRAL/EASTERN MONTANA.
FAIRLY STRONG COLD FRONTOGENESIS WAS BECOMING INCREASINGLY EVIDENT
ACROSS WESTERN MONTANA WITH 850MB TEMPERATURES BEHIND THE COLD FRONT
IN WASHINGTON STATE FROM +6 TO +11C. THE HOTTEST TEMPERATURES AT
850MB WERE FOUND ALONG A LINE FROM ROUGHLY THE NEBRASKA PANHANDLE TO
SOUTHEASTERN SOUTH DAKOTA WHERE TEMPS RANGED FROM +30 TO +33C ALONG
THIS AXIS. WITHIN THIS HEAT AXIS...VALENTINE NEBRASKA REACHED A HIGH
TEMPERATURE OF 109F.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 406 AM CDT TUE JUL 24 2012
AS THE STRONG, COMPACT UPPER LOW MOVES EAST ACROSS THE CANADIAN
PRAIRIES TODAY...THE COLD FRONT TIED TO THIS UPPER FEATURE WILL MOVE
SOUTH DOWN THE NORTHERN HIGH PLAINS TODAY AND TONIGHT. AS THIS IS
HAPPENING...THE LEE TROUGH OVER EASTERN COLORADO WILL FURTHER
DEEPEN AS WELL RESULTING IN INCREASED PRESSURE GRADIENT AND STRONGER
SURFACE WINDS. 18 TO 22 KT SURFACE WINDS ARE FORECAST ACROSS
SOUTHWEST KANSAS FROM THE SOUTH-SOUTHWEST. HIGHS WILL BE SIMILAR TO
THAT OF THE PAST FEW DAYS...WITH WARMEST TEMPERATURES FARTHER NORTH
WHERE THE LOW LEVEL THERMAL NOSE WILL ADVANCE FARTHER EAST IN
NORTHWEST KANSAS SUPPORTING 105 TO 107 DEGREE LATE AFTERNOON
TEMPERATURES. ELSEWHERE SOUTH OF A SCOTT CITY TO HAYS LINE HIGHS
WILL RANGE FROM 100 TO 103F. TONIGHT...THE PRESSURE GRADIENT WILL
STILL BE STRONG ENOUGH TO KEEP WINDS UP IN THE 10-15 KNOT RANGE
THROUGH THE NIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 406 AM CDT TUE JUL 24 2012
MEDIUM RANGE MODELS INDICATE AN UPPER LEVEL SHORTWAVE TROUGH OF LOW
PRESSURE EJECTING EASTWARD OUT OF THE CENTRAL AND SOUTHERN ROCKIES
INTO THE WESTERN HIGH PLAINS WEDNESDAY BRINGING A MUCH NEEDED CHANCE
FOR PRECIP TO PORTIONS OF WESTERN KANSAS. AN ATTENDANT COLD FRONT IS
PROJECTED TO PUSH SOUTHEAST INTO WESTERN KANSAS SOMETIME BY EARLY TO
MID AFTERNOON WEDNESDAY SETTING THE STAGE FOR POSSIBLE SHOWER AND
THUNDERSTORM DEVELOPMENT. AS THE FRONT BEGINS TO PUSH INTO THE STATE,
THE NAM, GEM, GFS, AND ECMWF POINT TO A SURFACE LOW DEVELOPING ALONG
THE FRONT, GENERALLY ACROSS SOUTHWEST KANSAS. THIS WILL INCREASE LOW
LEVEL FORCING, PARTICULARLY TO THE NORTH AND EAST OF THE SURFACE LOW
ALONG THE BOUNDARY ITSELF. AMPLE MOISTURE WILL BE ON HAND AS A
PREVAILING LOW LEVEL SOUTHERLY FLOW IS EXPECTED TO DRIVE IT NORTH
WITH H85 DEWPOINTS JUST ABOVE 10C ACROSS MUCH OF CENTRAL AND WESTERN
KANSAS. ADDITIONALLY, NAM AND GFS MODEL SOUNDINGS DO POINT TO PLENTY
OF AVAILABLE MID/UPPER LEVEL INSTABILITY BY WEDNESDAY AFTERNOON WITH
CAPE VALUES IN EXCESS OF 1500 TO 2000 J/KG. HOWEVER, A COUPLE OF
FACTORS MAY LIMIT CONVECTION ACROSS WESTERN KANSAS AS THE FRONTAL
BOUNDARY BEGINS TO PUSH INTO THE AREA. FIRST WILL BE AN EXPECTED
WEAK FLOW ALOFT AS ALL MODELS KEEP THE UPPER LEVEL JET JUST OFF TO
OUR NORTH ACROSS THE NORTHERN PLAINS. CAPPING COULD ALSO PLAY A
LIMITING FACTOR AS A HOT AFTERNOON THE PREVIOUS DAY WILL HAVE HIGH
TEMPERATURES UP NEAR TO JUST ABOVE 100F.
BECAUSE OF THE WEAK FLOW ALOFT AND THE LIKELY LOCATION OF THE
DEVELOPING SURFACE LOW, WILL KEEP 30 POPS IN ACROSS MUCH OF THE AREA
WITH 40 POPS FURTHER NORTHEAST IN CENTRAL KANSAS, ALONG WHERE THE
BOUNDARY IS EXPECTED TO BE LATE WEDNESDAY. ANY DEVELOPING STORMS ARE
ALSO EXPECTED TO BE ELEVATED WITH STRONG OUTFLOW WINDS THE PRIMARY
THREAT. DRIER CONDITIONS ARE EXPECTED THROUGH THE REMAINDER OF THE
PERIOD AS UPPER LEVEL RIDGING REDEVELOPS ACROSS THE INTERMOUNTAIN
WEST BY THURSDAY AND PUSHES SLOWLY EAST INTO THE WESTERN HIGH PLAINS
THROUGH THE WEEKEND.
TEMPERATURES ARE EXPECTED TO BE ABOVE NORMAL WEDNESDAY EVEN AS THE
COLD FRONT BEGINS TO PUSH SOUTHEAST INTO WESTERN KANSAS BY MID DAY.
AHEAD OF THE COLD FRONT, THE NAM, GFS, AND ECMWF SHOW H85
TEMPERATURES RANGING FROM THE UPPER 20S(C) ACROSS CENTRAL KANSAS
TO JUST ABOVE 30C ACROSS MUCH OF SOUTHWEST KANSAS. CONSIDERING HOW
SLOW THE MODELS HAVE THE FRONT PROJECTED TO MOVE THROUGH THE AREA,
LOOK FOR HIGHS ABOVE 100F ACROSS CENTRAL AND MUCH OF SOUTHWEST
KANSAS AGAIN WEDNESDAY AFTERNOON. HOWEVER, A BRIEF REPRIEVE FROM
TRIPLE DIGIT HIGHS IS LIKELY THURSDAY IN WAKE OF THE SLOW MOVING
COLD FRONT. A NORTH TO NORTHEAST LOW LEVEL FLOW INTO WESTERN KANSAS
WILL HELP LOWER H85 TEMPERATURES BY JUST A FEW DEGREES. EVEN SO,
EXPECT HIGHS ONLY UP INTO THE 90S(F) THURSDAY AFTERNOON. A GRADUAL
WARMING TREND IS THEN EXPECTED AGAIN AS THE AFOREMENTIONED UPPER
LEVEL RIDGING DEVELOPS ACROSS THE INTERMOUNTAIN WEST BY THURSDAY AND
BEGINS TO PUSH EAST INTO THE WESTERN HIGH PLAINS THROUGH THE WEEKEND.
SHOULD SEE HIGHS CLIMBING BACK TO JUST ABOVE 100F BY THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 603 AM CDT TUE JUL 24 2012
VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES THROUGH LATE THIS
EVENING. AS FOR WINDS, A LEE SIDE TROUGH OF LOW PRESSURE WILL
STRENGTHEN ACROSS EXTREME EASTERN COLORADO TODAY. AS A RESULT,
SOUTHERLY WINDS OF 10 TO 15KT EARLY THIS MORNING WILL INCREASE
UP TO AROUND 20 TO 30KT THROUGH EARLY THIS AFTERNOON. WINDS WILL
SUBSIDE BACK TO AROUND 10 TO 15KT THIS EVENING WITH THE LOSS OF
DAYTIME HEATING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 101 73 103 69 / 10 10 20 30
GCK 104 70 102 68 / 10 10 30 30
EHA 99 70 98 66 / 20 20 30 30
LBL 100 72 102 69 / 20 20 30 30
HYS 106 73 104 69 / 0 10 30 40
P28 102 75 104 72 / 10 10 10 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...UMSCHEID
LONG TERM...JJOHNSON
AVIATION...JJOHNSON
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
413 AM CDT TUE JUL 24 2012
...UPDATED SHORT TERM AND LONG TERM SECTIONS...
.SYNOPSIS...
ISSUED AT 112 AM CDT TUE JUL 24 2012
A FAIRLY IMPRESSIVE UPPER LOW BY MID-SUMMER STANDARDS WAS CENTERED
OVER SOUTHERN ALBERTA AS OF 24.05Z WITH A COMPACT 70-80 KNOT JET
STREAK ON THE SOUTHEAST SIDE OF THE LOW AT 400MB (PER RAP ANALYSIS).
THERE WAS ANOTHER DEPARTING MID-UPPER LEVEL TROUGH ACROSS
SOUTHEASTERN CANADA TO THE NORTHERN GREAT LAKES REGION. IN THE
LOWER TROPOSPHERE...A FRONT WAS EVIDENT IN THE 850MB ANALYSIS
EXTENDING FROM LOWER MICHIGAN TO SOUTHERN MINNESOTA. THE FRONT
CONTINUED WEST TOWARD JUST SOUTH OF THE BLACK HILLS REGION WHICH
COULD BE FOLLOWED BACK NORTHWEST INTO CENTRAL/EASTERN MONTANA.
FAIRLY STRONG COLD FRONTOGENESIS WAS BECOMING INCREASINGLY EVIDENT
ACROSS WESTERN MONTANA WITH 850MB TEMPERATURES BEHIND THE COLD FRONT
IN WASHINGTON STATE FROM +6 TO +11C. THE HOTTEST TEMPERATURES AT
850MB WERE FOUND ALONG A LINE FROM ROUGHLY THE NEBRASKA PANHANDLE TO
SOUTHEASTERN SOUTH DAKOTA WHERE TEMPS RANGED FROM +30 TO +33C ALONG
THIS AXIS. WITHIN THIS HEAT AXIS...VALENTINE NEBRASKA REACHED A HIGH
TEMPERATURE OF 109F.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 406 AM CDT TUE JUL 24 2012
AS THE STRONG, COMPACT UPPER LOW MOVES EAST ACROSS THE CANADIAN
PRAIRIES TODAY...THE COLD FRONT TIED TO THIS UPPER FEATURE WILL MOVE
SOUTH DOWN THE NORTHERN HIGH PLAINS TODAY AND TONIGHT. AS THIS IS
HAPPENING...THE LEE TROUGH OVER EASTERN COLORADO WILL FURTHER
DEEPEN AS WELL RESULTING IN INCREASED PRESSURE GRADIENT AND STRONGER
SURFACE WINDS. 18 TO 22 KT SURFACE WINDS ARE FORECAST ACROSS
SOUTHWEST KANSAS FROM THE SOUTH-SOUTHWEST. HIGHS WILL BE SIMILAR TO
THAT OF THE PAST FEW DAYS...WITH WARMEST TEMPERATURES FARTHER NORTH
WHERE THE LOW LEVEL THERMAL NOSE WILL ADVANCE FARTHER EAST IN
NORTHWEST KANSAS SUPPORTING 105 TO 107 DEGREE LATE AFTERNOON
TEMPERATURES. ELSEWHERE SOUTH OF A SCOTT CITY TO HAYS LINE HIGHS
WILL RANGE FROM 100 TO 103F. TONIGHT...THE PRESSURE GRADIENT WILL
STILL BE STRONG ENOUGH TO KEEP WINDS UP IN THE 10-15 KNOT RANGE
THROUGH THE NIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 406 AM CDT TUE JUL 24 2012
MEDIUM RANGE MODELS INDICATE AN UPPER LEVEL SHORTWAVE TROUGH OF LOW
PRESSURE EJECTING EASTWARD OUT OF THE CENTRAL AND SOUTHERN ROCKIES
INTO THE WESTERN HIGH PLAINS WEDNESDAY BRINGING A MUCH NEEDED CHANCE
FOR PRECIP TO PORTIONS OF WESTERN KANSAS. AN ATTENDANT COLD FRONT IS
PROJECTED TO PUSH SOUTHEAST INTO WESTERN KANSAS SOMETIME BY EARLY TO
MID AFTERNOON WEDNESDAY SETTING THE STAGE FOR POSSIBLE SHOWER AND
THUNDERSTORM DEVELOPMENT. AS THE FRONT BEGINS TO PUSH INTO THE STATE,
THE NAM, GEM, GFS, AND ECMWF POINT TO A SURFACE LOW DEVELOPING ALONG
THE FRONT, GENERALLY ACROSS SOUTHWEST KANSAS. THIS WILL INCREASE LOW
LEVEL FORCING, PARTICULARLY TO THE NORTH AND EAST OF THE SURFACE LOW
ALONG THE BOUNDARY ITSELF. AMPLE MOISTURE WILL BE ON HAND AS A
PREVAILING LOW LEVEL SOUTHERLY FLOW IS EXPECTED TO DRIVE IT NORTH
WITH H85 DEWPOINTS JUST ABOVE 10C ACROSS MUCH OF CENTRAL AND WESTERN
KANSAS. ADDITIONALLY, NAM AND GFS MODEL SOUNDINGS DO POINT TO PLENTY
OF AVAILABLE MID/UPPER LEVEL INSTABILITY BY WEDNESDAY AFTERNOON WITH
CAPE VALUES IN EXCESS OF 1500 TO 2000 J/KG. HOWEVER, A COUPLE OF
FACTORS MAY LIMIT CONVECTION ACROSS WESTERN KANSAS AS THE FRONTAL
BOUNDARY BEGINS TO PUSH INTO THE AREA. FIRST WILL BE AN EXPECTED
WEAK FLOW ALOFT AS ALL MODELS KEEP THE UPPER LEVEL JET JUST OFF TO
OUR NORTH ACROSS THE NORTHERN PLAINS. CAPPING COULD ALSO PLAY A
LIMITING FACTOR AS A HOT AFTERNOON THE PREVIOUS DAY WILL HAVE HIGH
TEMPERATURES UP NEAR TO JUST ABOVE 100F.
BECAUSE OF THE WEAK FLOW ALOFT AND THE LIKELY LOCATION OF THE
DEVELOPING SURFACE LOW, WILL KEEP 30 POPS IN ACROSS MUCH OF THE AREA
WITH 40 POPS FURTHER NORTHEAST IN CENTRAL KANSAS, ALONG WHERE THE
BOUNDARY IS EXPECTED TO BE LATE WEDNESDAY. ANY DEVELOPING STORMS ARE
ALSO EXPECTED TO BE ELEVATED WITH STRONG OUTFLOW WINDS THE PRIMARY
THREAT. DRIER CONDITIONS ARE EXPECTED THROUGH THE REMAINDER OF THE
PERIOD AS UPPER LEVEL RIDGING REDEVELOPS ACROSS THE INTERMOUNTAIN
WEST BY THURSDAY AND PUSHES SLOWLY EAST INTO THE WESTERN HIGH PLAINS
THROUGH THE WEEKEND.
TEMPERATURES ARE EXPECTED TO BE ABOVE NORMAL WEDNESDAY EVEN AS THE
COLD FRONT BEGINS TO PUSH SOUTHEAST INTO WESTERN KANSAS BY MID DAY.
AHEAD OF THE COLD FRONT, THE NAM, GFS, AND ECMWF SHOW H85
TEMPERATURES RANGING FROM THE UPPER 20S(C) ACROSS CENTRAL KANSAS
TO JUST ABOVE 30C ACROSS MUCH OF SOUTHWEST KANSAS. CONSIDERING HOW
SLOW THE MODELS HAVE THE FRONT PROJECTED TO MOVE THROUGH THE AREA,
LOOK FOR HIGHS ABOVE 100F ACROSS CENTRAL AND MUCH OF SOUTHWEST
KANSAS AGAIN WEDNESDAY AFTERNOON. HOWEVER, A BRIEF REPRIEVE FROM
TRIPLE DIGIT HIGHS IS LIKELY THURSDAY IN WAKE OF THE SLOW MOVING
COLD FRONT. A NORTH TO NORTHEAST LOW LEVEL FLOW INTO WESTERN KANSAS
WILL HELP LOWER H85 TEMPERATURES BY JUST A FEW DEGREES. EVEN SO,
EXPECT HIGHS ONLY UP INTO THE 90S(F) THURSDAY AFTERNOON. A GRADUAL
WARMING TREND IS THEN EXPECTED AGAIN AS THE AFOREMENTIONED UPPER
LEVEL RIDGING DEVELOPS ACROSS THE INTERMOUNTAIN WEST BY THURSDAY AND
BEGINS TO PUSH EAST INTO THE WESTERN HIGH PLAINS THROUGH THE WEEKEND.
SHOULD SEE HIGHS CLIMBING BACK TO JUST ABOVE 100F BY THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 112 AM CDT TUE JUL 24 2012
A LEESIDE TROUGH WILL CONTINUE TO STRENGTHEN ACROSS EASTERN COLORADO
ON TUESDAY WHICH WILL SUPPORT STRONGER SURFACE WINDS. WINDS ARE
EXPECTED TO RANGE FROM 18 TO 22 KNOTS DURING THE MIDDAY TO EARLY
EVENING HOURS WITH SOME GUSTS APPROACHING 30 KNOTS AT TIMES. THIS
WILL BE THE MAIN AVIATION WEATHER HIGHLIGHT AS SKIES WILL CONTINUE
TO BE CLEAR TO MOSTLY CLEAR WITH VFR CATEGORY PREVAILING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 101 73 103 69 / 10 10 20 30
GCK 104 70 102 68 / 10 10 30 30
EHA 99 70 98 66 / 20 20 30 30
LBL 100 72 102 69 / 20 20 30 30
HYS 106 73 104 69 / 0 10 30 40
P28 102 75 104 72 / 10 10 10 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...UMSCHEID
LONG TERM...JJOHNSON
AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
113 AM CDT TUE JUL 24 2012
...UPDATED SYNOPSIS AND AVIATION SECTION FOR 06Z TAFS...
.SYNOPSIS...
ISSUED AT 112 AM CDT TUE JUL 24 2012
A FAIRLY IMPRESSIVE UPPER LOW BY MID-SUMMER STANDARDS WAS CENTERED
OVER SOUTHERN ALBERTA AS OF 24.05Z WITH A COMPACT 70-80 KNOT JET
STREAK ON THE SOUTHEAST SIDE OF THE LOW AT 400MB (PER RAP ANALYSIS).
THERE WAS ANOTHER DEPARTING MID-UPPER LEVEL TROUGH ACROSS
SOUTHEASTERN CANADA TO THE NORTHERN GREAT LAKES REGION. IN THE
LOWER TROPOSPHERE...A FRONT WAS EVIDENT IN THE 850MB ANALYSIS
EXTENDING FROM LOWER MICHIGAN TO SOUTHERN MINNESOTA. THE FRONT
CONTINUED WEST TOWARD JUST SOUTH OF THE BLACK HILLS REGION WHICH
COULD BE FOLLOWED BACK NORTHWEST INTO CENTRAL/EASTERN MONTANA.
FAIRLY STRONG COLD FRONTOGENESIS WAS BECOMING INCREASINGLY EVIDENT
ACROSS WESTERN MONTANA WITH 850MB TEMPERATURES BEHIND THE COLD FRONT
IN WASHINGTON STATE FROM +6 TO +11C. THE HOTTEST TEMPERATURES AT
850MB WERE FOUND ALONG A LINE FROM ROUGHLY THE NEBRASKA PANHANDLE TO
SOUTHEASTERN SOUTH DAKOTA WHERE TEMPS RANGED FROM +30 TO +33C ALONG
THIS AXIS. WITHIN THIS HEAT AXIS...VALENTINE NEBRASKA REACHED A HIGH
TEMPERATURE OF 109F.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 329 PM CDT MON JUL 23 2012
OVER THE NEXT 24-36 HOURS, THE UPPER LEVEL RIDGE AXIS THAT HAS
PERSISTED OVER THE CENTRAL PLAINS WILL START TO WEAKEN IN RESPONSE
TO THE AFOREMENTIONED UPPER-LEVEL TROUGHING PROGRESSING ACROSS THE
NORTHERN PLAINS, WITH 500MB HEIGHTS DROPPING SEVERAL DECAMETERS.
HOWEVER, SEA LEVEL PRESSURE VALUES ARE PROGGED TO FALL ACROSS THE
HIGH PLAINS OF EASTERN COLORADO BY TUESDAY AS THE WEAK BOUNDARY OR
WARM FRONT MOVES NORTHWARD INTO SOUTHWEST KANSAS IN RESPONSE TO THE
UPPER LEVEL SYSTEMS. SO DESPITE THE 500MB HEIGHT FALLS, THE SURFACE
PRESSURES AND 1000MB HEIGHTS WILL ALSO BE FALLING, RESULTING IN
SIMILAR THICKNESS PATTERNS AND A CONTINUATION OF HOT TEMPERATURES.
THE ECMWF SHOWS VEERED 850MB WINDS LATE TONIGHT, PROVIDING A BURST
OF DOWNSLOPE FLOW THAT WILL MIX DOWN TO THE SURFACE WITH DAYTIME
HEATING. THUS, IT SHOULD BE A FEW DEGREES WARMER TOMORROW AS THE
WARM FRONT PASSES SINCE THE WINDS WILL BE MORE SOUTHERLY WITH NO
UPSLOPE COMPONENT, AND SINCE MIXING WILL BE STRONGER AND DEEPER.
UNTIL THEN, TONIGHT`S LOWS WILL BE SLIGHTLY HIGHER THAN LAST
NIGHT`S SINCE SURFACE WINDS ARE EXPECTED TO INCREASE BY 09-12Z AS
THE SURFACE BOUNDARY APPROACHES. VERY SMALL CHANCES FOR
THUNDERSTORMS WERE INTRODUCED FOR FAR SOUTHWEST KANSAS FOR
TUESDAY AFTERNOON BASED ON WHAT IS OCCURRING THIS AFTERNOON IN
WEST TEXAS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 347 PM CDT MON JUL 23 2012
A NORTHERN BRANCH SHORTWAVE TROUGH MOVES ACROSS THE NORTHERN AND
CENTRAL PLAINS ON WEDNESDAY. THIS WAVE WILL PUSH A WEAK COLD FRONT
ACROSS WESTERN KANSAS ON WEDNESDAY AND WEDNESDAY NIGHT. WILL
MAINTAIN A 30 POP FOR THUNDERSTORMS WITH THE FRONT. FORECAST CAPES
ARE AROUND 1000 J/KG HOWEVER UPPER LEVEL WINDS WILL BE WEAK. SURFACE
MOISTURE CONVERGENCE ALONG THE FRONT WILL BE THE MAIN SOURCE OF
LIFT. A FEW STORMS COULD HAVE SMALL HAIL AND STRONG WINDS, BUT
SEVERE THUNDERSTORMS ARE NOT ANTICIPATED. TEMPERATURES WILL BE HOT
AHEAD OF THE FRONT WITH 100 TO 105 DEGREES. COOLER TEMPS IN THE MID
90S ARE EXPECTED BEHIND THE FRONT ON THURSDAY. BY FRIDAY AND INTO
SATURDAY THE HOT UPPER LEVEL RIDGE REBUILDS INTO THE CENTRAL PLAINS
WITH 500MB HEIGHTS BACK TO 595 DECAMETERS. THIS WILL PUSH TEMPS BACK
TO AROUND THE CENTURY MARK. ON SUNDAY AND MONDAY ANOTHER NORTHERN
BRANCH WAVE IS FORECAST TO TOP THE RIDGE AND BRING DOWN ANOTHER
FRONTAL BOUNDARY. OVERNIGHT LOWS WILL BE MILD THROUGH THIS LONG TERM
PERIOD FROM THE UPPER 60S TO LOW TO MID 70S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 112 AM CDT TUE JUL 24 2012
A LEESIDE TROUGH WILL CONTINUE TO STRENGTHEN ACROSS EASTERN COLORADO
ON TUESDAY WHICH WILL SUPPORT STRONGER SURFACE WINDS. WINDS ARE
EXPECTED TO RANGE FROM 18 TO 22 KNOTS DURING THE MIDDAY TO EARLY
EVENING HOURS WITH SOME GUSTS APPROACHING 30 KNOTS AT TIMES. THIS
WILL BE THE MAIN AVIATION WEATHER HIGHLIGHT AS SKIES WILL CONTINUE
TO BE CLEAR TO MOSTLY CLEAR WITH VFR CATEGORY PREVAILING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 104 73 103 72 / 10 10 20 30
GCK 104 70 102 71 / 10 10 30 30
EHA 101 70 98 69 / 20 20 30 30
LBL 103 72 102 72 / 20 20 20 30
HYS 106 73 104 72 / 0 10 30 40
P28 104 75 104 75 / 10 10 10 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...FINCH
LONG TERM...KRUSE
AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS JACKSON KY
633 PM EDT TUE JUL 24 2012
.UPDATE...
ISSUED AT 633 PM EDT TUE JUL 24 2012
WITH A MUGGY AND UNSTABLE AIRMASS STILL IN PLACE ACROSS THE SOUTHWEST
ZONES...SPC HAS ISSUED A NEW SEVERE THUNDERSTORM WATCH UNTIL 11 PM.
ONLY A FEW STORMS AFFECTING THE AREA PRESENTLY...BUT WE COULD STILL
SEE SOME NEW DEVELOPMENT THIS EVENING. MEANWHILE...QUIET CONDITIONS
ACROSS A GOOD CHUNK OF EASTERN KENTUCKY WILL LIKELY STAY THAT WAY
THROUGH MUCH OF TONIGHT. THUS...POPS HAVE BEEN REMOVED OR LOWERED
ACROSS THE BOARD. ALSO...WITH TEMPERATURES ALREADY ON THE COOL SIDE
AND RECENT RAINFALL...WE MAY SEE SOME PATCHY FOG OVERNIGHT. ZONE
UPDATE IS ALREADY OUT.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 339 PM EDT TUE JUL 24 2012
IMMEDIATE SHORT TERM ISSUES REVOLVE AROUND THE ONGOING WATCH. WITH
MORE OF THE ACTIVITY SHIFTING SOUTHWARD...GOING TO CLEAR MORE
COUNTIES OUT OF EASTERN KENTUCKY OVER THE NEXT HOUR.
MEANWHILE...STILL WATCHING AN OUTFLOW BOUNDARY...FROM CENTRAL ESTILL
COUNTY...SOUTHEAST INTO SOUTHERN BREATHITT COUNTY. THIS BOUNDARY
COULD TRIGGER ADDITIONAL STORMS AS IT SINKS SOUTHWARD THIS EVENING.
THUS...THE WATCH WILL CONTINUE ACROSS OUR SOUTHWEST COUNTIES UNTIL
THIS BOUNDARY PUSHES ACROSS THIS AREA. THE HRRR CONTINUES TO SHOW NEW
DEVELOPMENT...BUT THUS FAR...HAVE NOT SEEN ANY DEVELOPMENT ALONG THIS
BOUNDARY.
AS THIS BOUNDARY AND COMPLEX OF STORMS EXITS TO THE SOUTH THIS
EVENING...THERE WILL LIKELY BE A TEMPORARY BREAK FROM THE CONVECTION.
HOWEVER...ANOTHER WEAK WAVE IS POISED TO DROP SOUTHWARD OVERNIGHT AND
COULD GENERATE MORE SHOWERS AND THUNDERSTORMS. WITH LITTLE ACTIVITY
UPSTREAM PRESENTLY...OPTING TO KEEP POPS ON THE LOWER SIDE UNTIL
BETTER CONFIDENCE CAN BE OBTAINED.
A NORTH/SOUTH BOUNDARY WILL THEN SET UP OVER FAR EASTERN KENTUCKY
THROUGH TOMORROW AFTERNOON AND EVENING. THIS WILL KEEP UNSETTLED
WEATHER IN THE FORECAST THROUGH WEDNESDAY EVENING AS DAYTIME
INSTABILITY WILL ONCE AGAIN FUEL STORM DEVELOPMENT...ESPECIALLY OVER
SOUTHEAST AND FAR EASTERN KENTUCKY. THE FURTHER WEST YOU GO AWAY FROM
THE BOUNDARY...THE MORE LIKELIHOOD TO MISS OUT ON ANY STORMS
TOMORROW. BASED ON THE WEAK STORM MOVEMENT TOMORROW AFTERNOON...WE
MAY HAVE TO WATCH FOR TRAINING STORMS AND FLASH FLOODING POTENTIAL.
PW`S WILL STILL BE CLOSE TO 2 INCHES TOMORROW...SO CLEARLY GOING TO
HAVE TO KEEP AN EYE ON THE FLOODING POTENTIAL. WE MAY NEED A FLASH
FLOOD WATCH...BUT WILL LET THE MIDNIGHT SHIFT REEVALUATE.
THIS BOUNDARY WILL EVENTUALLY DEPART TO THE NORTHEAST TOMORROW
NIGHT...TAKING THE THREAT OF PRECIPITATION WITH IT AND PUTTING THE
AREA UNDER STRONGER INFLUENCE OF THE HIGH. MILD CONDITIONS WILL
CONTINUE WITH HIGHS ON WEDNESDAY WELL INTO THE 80S...AND LOWS TONIGHT
AND WEDNESDAY NIGHT IN THE LOWER 70S.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 339 PM EDT TUE JUL 24 2012
THE MODELS ARE IN VERY GOOD AGREEMENT WITH THE GENERAL LONG WAVE
PATTERN. THURSDAY STARTS OUT WITH A UPPER LOW OVER MINNESOTA WITH A
TROUGH EXTENDING SOUTH ALONG THE I35 CORRIDOR. THE TROUGH WILL MOVE
TO THE EAST AND WILL PASS EASTERN KENTUCKY ON FRIDAY NIGHT/SATURDAY
MORNING TIME FRAME. THE TROUGH WILL FINALLY PUSH A LINGERING COLD
FRONT SOUTH AND EAST OF THE AREA ON FRIDAY. THIS WILL HELP TO BRING
SOME COOLER AND DRIER AIR INTO THE AREA. WITH THE MODELS IN SUCH
GOOD AGREEMENT...RELIED VERY HEAVILY ON THE MODEL BLEND FOR ALL
FIELDS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 130 PM EDT TUE JUL 24 2012
ALL OF EASTERN KENTUCKY IS UNDER A SEVERE THUNDERSTORM WATCH UNTIL
23Z. AS SUCH...THE THUNDERSTORMS OVER THE AREA ARE VERY DANGEROUS
AND THE POTENTIAL FOR LLWS IS GREATER THAN NORMAL. ONCE THE
THUNDERSTORMS MOVE THROUGH THE AREA...THEN FOG WILL BE A THREAT
TONIGHT...ESPECIALLY IN VALLEY LOCATIONS. HAVE PUT FOG IN FOR THE TAF
STATIONS...HOWEVER IF PRECIPITATION IS NOT VERY WIDESPREAD...THEN THE
FOG IS NOT AS LIKELY AT SME AND LOZ. SOMETIMES AFTER A RAIN...THERE
IS A TEMPO FOG CONDITION THAT IS NOT VERY LONG LIVED...HOWEVER TRYING
TO TIME IT IS ALMOST IMPOSSIBLE THIS FAR OUT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...KAS
LONG TERM....JJ
AVIATION...JJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
340 PM EDT TUE JUL 24 2012
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 339 PM EDT TUE JUL 24 2012
IMMEDIATE SHORT TERM ISSUES REVOLVE AROUND THE ONGOING WATCH. WITH
MORE OF THE ACTIVITY SHIFTING SOUTHWARD...GOING TO CLEAR MORE
COUNTIES OUT OF EASTERN KENTUCKY OVER THE NEXT HOUR.
MEANWHILE...STILL WATCHING AN OUTFLOW BOUNDARY...FROM CENTRAL ESTILL
COUNTY...SOUTHEAST INTO SOUTHERN BREATHITT COUNTY. THIS BOUNDARY
COULD TRIGGER ADDITIONAL STORMS AS IT SINKS SOUTHWARD THIS EVENING.
THUS...THE WATCH WILL CONTINUE ACROSS OUR SOUTHWEST COUNTIES UNTIL
THIS BOUNDARY PUSHES ACROSS THIS AREA. THE HRRR CONTINUES TO SHOW NEW
DEVELOPMENT...BUT THUS FAR...HAVE NOT SEEN ANY DEVELOPMENT ALONG THIS
BOUNDARY.
AS THIS BOUNDARY AND COMPLEX OF STORMS EXITS TO THE SOUTH THIS
EVENING...THERE WILL LIKELY BE A TEMPORARY BREAK FROM THE CONVECTION.
HOWEVER...ANOTHER WEAK WAVE IS POISED TO DROP SOUTHWARD OVERNIGHT AND
COULD GENERATE MORE SHOWERS AND THUNDERSTORMS. WITH LITTLE ACTIVITY
UPSTREAM PRESENTLY...OPTING TO KEEP POPS ON THE LOWER SIDE UNTIL
BETTER CONFIDENCE CAN BE OBTAINED.
A NORTH/SOUTH BOUNDARY WILL THEN SET UP OVER FAR EASTERN KENTUCKY
THROUGH TOMORROW AFTERNOON AND EVENING. THIS WILL KEEP UNSETTLED
WEATHER IN THE FORECAST THROUGH WEDNESDAY EVENING AS DAYTIME
INSTABILITY WILL ONCE AGAIN FUEL STORM DEVELOPMENT...ESPECIALLY OVER
SOUTHEAST AND FAR EASTERN KENTUCKY. THE FURTHER WEST YOU GO AWAY FROM
THE BOUNDARY...THE MORE LIKELIHOOD TO MISS OUT ON ANY STORMS
TOMORROW. BASED ON THE WEAK STORM MOVEMENT TOMORROW AFTERNOON...WE
MAY HAVE TO WATCH FOR TRAINING STORMS AND FLASH FLOODING POTENTIAL.
PW`S WILL STILL BE CLOSE TO 2 INCHES TOMORROW...SO CLEARLY GOING TO
HAVE TO KEEP AN EYE ON THE FLOODING POTENTIAL. WE MAY NEED A FLASH
FLOOD WATCH...BUT WILL LET THE MIDNIGHT SHIFT REEVALUATE.
THIS BOUNDARY WILL EVENTUALLY DEPART TO THE NORTHEAST TOMORROW
NIGHT...TAKING THE THREAT OF PRECIPITATION WITH IT AND PUTTING THE
AREA UNDER STRONGER INFLUENCE OF THE HIGH. MILD CONDITIONS WILL
CONTINUE WITH HIGHS ON WEDNESDAY WELL INTO THE 80S...AND LOWS TONIGHT
AND WEDNESDAY NIGHT IN THE LOWER 70S.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 339 PM EDT TUE JUL 24 2012
THE MODELS ARE IN VERY GOOD AGREEMENT WITH THE GENERAL LONG WAVE
PATTERN. THURSDAY STARTS OUT WITH A UPPER LOW OVER MINNESOTA WITH A
TROUGH EXTENDING SOUTH ALONG THE I35 CORRIDOR. THE TROUGH WILL MOVE
TO THE EAST AND WILL PASS EASTERN KENTUCKY ON FRIDAY NIGHT/SATURDAY
MORNING TIME FRAME. THE TROUGH WILL FINALLY PUSH A LINGERING COLD
FRONT SOUTH AND EAST OF THE AREA ON FRIDAY. THIS WILL HELP TO BRING
SOME COOLER AND DRIER AIR INTO THE AREA. WITH THE MODELS IN SUCH
GOOD AGREEMENT...RELIED VERY HEAVILY ON THE MODEL BLEND FOR ALL
FIELDS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 130 PM EDT TUE JUL 24 2012
ALL OF EASTERN KENTUCKY IS UNDER A SEVERE THUNDERSTORM WATCH UNTIL
23Z. AS SUCH...THE THUNDERSTORMS OVER THE AREA ARE VERY DANGEROUS
AND THE POTENTIAL FOR LLWS IS GREATER THAN NORMAL. ONCE THE
THUNDERSTORMS MOVE THROUGH THE AREA...THEN FOG WILL BE A THREAT
TONIGHT...ESPECIALLY IN VALLEY LOCATIONS. HAVE PUT FOG IN FOR THE TAF
STATIONS...HOWEVER IF PRECIPITATION IS NOT VERY WIDESPREAD...THEN THE
FOG IS NOT AS LIKELY AT SME AND LOZ. SOMETIMES AFTER A RAIN...THERE
IS A TEMPO FOG CONDITION THAT IS NOT VERY LONG LIVED...HOWEVER TRYING
TO TIME IT IS ALMOST IMPOSSIBLE THIS FAR OUT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KAS
LONG TERM....JJ
AVIATION...JJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
259 PM EDT TUE JUL 24 2012
.UPDATE...
ISSUED AT 258 PM EDT TUE JUL 24 2012
CLEARED COUNTIES NORTH OF I-64 OUT OF THE WATCH WITH THE COMPLEX OF
STORMS PUSHING OFF TO THE SOUTH. MAIN THREAT FOR SHOWERS AND STORMS
IN THE IMMEDIATE FUTURE IS BASICALLY EAST AND SOUTH OF JACKSON.
HOWEVER...STILL SOME BOUNDARIES PUSHING INTO AREAS FURTHER WEST...SO
CANNOT RULE OUT SOME REDEVELOPMENT THROUGH THE EVENING HOURS.
UPDATE ISSUED AT 1237 PM EDT TUE JUL 24 2012
MCS CONTINUES TO PROGRESS SOUTHWARD AND A WATCH HAS BEEN ISSUED FOR
ALL OF EASTERN KENTUCKY. THE MAIN THREAT WILL BE DAMAGING WINDS AS
THIS SYSTEM PUSHES SOUTH THROUGH THE AFTERNOON HOURS. EXPECTED
ARRIVAL TIMES IS FROM AROUND 1 PM IN THE NORTH TO 5 PM IN THE SOUTH
(NEAR THE TENNESSEE BORDER). STILL RECEIVING LOTS OF REPORTS OF
DAMAGE TO THE NORTH...SO THINGS COULD GET VERY INTERESTING IN OUR
NECK OF THE WOODS THIS AFTERNOON...ESPECIALLY WITH AREAS IN OUR
SOUTHWEST ALREADY VERY UNSTABLE WITH 3000J/KG OF SBCAPE.
UPDATE ISSUED AT 1216 PM EDT TUE JUL 24 2012
MCS IN SOUTHERN OHIO HAS TAKEN MORE OF A TURN TO THE SOUTH AND NOW IS
LOOKING LIKE IT MAY TAKE AIM ON MUCH OF EASTERN KENTUCKY. THIS SYSTEM
HAS BEEN PRODUCING PRETTY WIDESPREAD WIND DAMAGE AS IT HAS TRACKED
SOUTHWARD...SO IF IT HOLDS TOGETHER SPC MAY END UP ISSUING A WATCH
FOR OUR AREA. THIS SYSTEM MAY EXPAND A BIT TO THE WEST AS IT TRACKS
SOUTH WITH PLENTY OF INSTABILITY TO TO FEED OFF OF JUST TO THE WEST.
UPDATE ISSUED AT 1057 AM EDT TUE JUL 24 2012
COMPLEX OF SHOWERS AND STORMS CURRENTLY DROPPING SOUTHEAST ACROSS
EASTERN KENTUCKY. VERY COMPLEX PATTERN SETTING UP FOR THIS AFTERNOON.
IT LOOKS LIKE A DIFFERENTIAL TEMPERATURE BOUNDARY MAY BECOME
ESTABLISHED AFTER THIS MORNINGS ACTIVITY EXITS...CREATING A FOCUS FOR
NEW DEVELOPMENT BASICALLY ALONG AND SOUTHWEST OF A LINE FROM MOUNT
STERLING...THROUGH JACKSON...TO HARLAN. THUS...BELIEVE THE TARGETED
AREA WILL BE OUR MORE SOUTHWESTERN ZONES...CONTRARY TO THE PREVIOUS
FORECAST. THE HRRR SUPPORTS THIS IDEA WITH MOST OF THE ACTIVITY THIS
AFTERNOON AND EVENING IN OUR SOUTHWEST. THIS IS ALSO SUPPORTED BY AN
OUTFLOW BOUNDARY GENERATED FROM AN MCS CURRENTLY PUSHING INTO
SOUTHWEST OHIO. THIS WILL LIKELY PUSH THIS OUTFLOW BOUNDARY INTO
EASTERN KENTUCKY AS THIS SYSTEM TRACKS SOUTH AND EAST INTO WEST
VIRGINIA BY MIDDAY. THE AREA SEEING THE SHOWER AND STORM ACTIVITY
PRESENTLY WILL HAVE A TOUGH TIME REGENERATING ANY INSTABILITY...BUT
AREAS UNTAPPED TO THE SOUTHWEST WILL BE A DIFFERENT STORY. THUS...THE
SEVERE THREAT STILL SEEMS REASONABLE...BUT MAINLY FOR THE SOUTHWEST
ZONES. DAMAGING WINDS WILL BE THE PRIMARY THREAT. IT APPEARS THE MAIN
THREAT FOR SEVERE WEATHER WILL START AFTER 3 PM UNTIL 9 OR 10 PM.
UPDATE ISSUED AT 804 AM EDT TUE JUL 24 2012
UPDATED TO ALLOW FOR EARLIER ARRIVAL OF PRECIP POTENTIAL TODAY...WITH
SCATTERED SHOWERS AND STORMS ALREADY PRESENTLY DEVELOPING AND
ENTERING THE FORECAST AREA FROM THE NW.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 352 AM EDT TUE JUL 24 2012
THUNDERSTORMS WERE EXPLODING UPSTREAM OVER NORTH CENTRAL INDIANA AT
3 AM...WITH MORE OF THEM FURTHER NORTHWEST OVER THE UPPER MISSISSIPPI
VALLEY. THIS ACTIVITY INITIATED NEAR A FRONTAL BOUNDARY UNDER THE
PERIPHERY OF AN UPPER RIDGE. MODELS SHOW CONVECTION RUNNING AROUND
THE PERIPHERY OF THE RIDGE AND DEVELOPING/PROPAGATING INTO THE LOCAL
AREA DURING THE DAY. FORECAST SOUNDINGS SHOW AMPLE INSTABILITY
BUILDING DURING THE DAY...WITH CAPE LIKELY REACHING 2500-3000 J/KG.
ALTHOUGH SHEAR WILL NOT BE PHENOMENAL...IT SHOULD AT LEAST ALLOW FOR
ORGANIZATION...WITH A LIMITED AMOUNT OF BOTH SPEED AND DIRECTIONAL
SHEAR. IT WILL BE THROUGH A DEEP LAYER AND NOT CONCENTRATED IN THE
LOW LEVELS. ALSO FREEZING LEVELS WILL BE HIGH...IN THE NEIGHBORHOOD
OF 14-14.5K FEET. THUS...THE MAIN SEVERE THREAT LOOKS TO BE
WIND...BUT WITH STRONG INSTABILITY AND SOME POTENTIAL FOR STORM
ROTATION...HAIL ALSO NEEDS TO BE CONSIDERED.
THE SURFACE COLD FRONT IS EXPECTED TO SAG INTO KY TONIGHT...AND WOULD
NOT RULE OUT ADDITIONAL CONVECTION DEVELOPING. HOWEVER...IF
INSTABILITY IS SPENT ON EARLIER CONVECTION...CONFIDENCE IN COVERAGE
IS NOT AS HIGH DURING THE NIGHT.
ON WEDNESDAY...THE FRONT RETREATS TO THE NORTHEAST AND UPPER RIDGING
ALSO SHIFTS EASTWARD OVER THE AREA...WITH WINDS ALOFT WEAKENING. LOW
LEVEL MOISTURE SHOULD ALSO BE SLIGHTLY LESS...WHILE MID LEVEL TEMPS
WARM SLIGHTLY. ALL COMBINED...CONDITIONS WILL NOT BE AS FAVORABLE FOR
WIDESPREAD CONVECTION...AND HAVE USED LOWER POPS ONLY IN THE SLIGHT
CHANCE RANGE ON WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 400 AM EDT TUE JUL 24 2012
THE 24.00Z MODEL SUITE REMAINS IN FAIRLY GOOD AGREEMENT WITH THE
EVOLUTION OF THE UPPER LEVEL PATTERN THROUGH THE MAJORITY OF THE
PERIOD BUT DOES SHOW MINOR DIFFERENCES WITH HOW THINGS END UP TOWARDS
THE BEGINNING OF NEXT WEEK. AS SUCH...HAVE GENERALLY RELIED ON A
BLENDED CONSENSUS WITH A LITTLE MORE WEIGHT TO A SLIGHTLY MORE
REASONABLE 24.00Z ECMWF FOR SPECIFICS. WILL KICK OFF WITH ANY
LINGERING ACTIVITY FROM WEDNESDAY DWINDLING WITH THE USUAL LOSS OF
DAYTIME HEATING INFLUENCES AS ANOTHER LOW PRESSURE SYSTEM CURRENTLY
OVER THE CANADIAN ROCKIES BEGINS CARVING INTO THE NRN PLAINS AND
UPPER MIDWEST. THE SFC REFLECTION IS EXPECTED TO BEGIN TRAVERSING THE
GREAT LAKES WEDNESDAY NIGHT INTO THURSDAY WITH THE ASSOCIATED RAINS
ALONG THE COLD FRONT STILL OVER THE MIDWEST AND UPPER MS VALLEY.
CURRENT CONSENSUS BRINGS THE FORCING ASSOCIATED WITH THE FRONT INTO
THE LOCAL PICTURE LATE THURSDAY/THURSDAY NIGHT AND CONTINUING
THROUGH THE DAY ON FRIDAY AS FAVORABLE RIGHT ENTRANCE DYNAMICS OF AN
UPPER LEVEL JET GRACES THE OHIO VALLEY. HAVE TRENDED THE FORECAST
DRIER FOR MUCH OF THE AREA THROUGH MOST OF THURSDAY WITH POPS
PEAKING THURSDAY NIGHT AND FRIDAY. MODELS ARE FAIRLY PROGRESSIVE
WITH THE PARENT UPPER LEVEL TROF...PUSHING IT THROUGH THE COAL
FIELDS ON SATURDAY AS HEIGHTS BEGIN SLOWLY REBOUNDING OVER ERN KY IN
RESPONSE TO SFC HIGH PRESSURE BUILDING DOWN FROM THE GREAT LAKES
WHILE THE PERSISTENT UPPER LEVEL PLAINS RIDGE BEGINS REBUILDING AND
EXPANDING ACROSS THE MS VALLEY. THIS SHOULD PROVIDE FOR A RELATIVELY
QUIET...IF NOT DRY SPELL OVER MOST OF THE UPCOMING WEEKEND.
AS FOR TEMPERATURES...GIVEN THE RELATIVELY GOOD AGREEMENT AMONG THE
GUIDANCE SAW NO REASON TO DEVIATE TOO FAR FROM THE LATEST OFFERINGS
WHICH WERE STILL IN LINE WITH THE INHERITED NUMBERS. THIS RESULTED
IN TEMPS GENERALLY RUNNING ABOVE NORMAL EARLY IN THE PERIOD...WITH
HEAT INDICES ON THURSDAY QUITE POSSIBLY RETURNING TO THE TRIPLE
DIGITS AHEAD OF THE FRONT...BEFORE TURNING TOWARDS CLIMO ON FRIDAY
WITH HIGHS IN THE MID TO UPPER 80S AND OVERNIGHT LOWS GENERALLY IN
THE UPPER 60S THROUGH THE REMAINDER OF THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 130 PM EDT TUE JUL 24 2012
ALL OF EASTERN KENTUCKY IS UNDER A SEVERE THUNDERSTORM WATCH UNTIL
23Z. AS SUCH...THE THUNDERSTORMS OVER THE AREA ARE VERY DANGEROUS
AND THE POTENTIAL FOR LLWS IS GREATER THAN NORMAL. ONCE THE
THUNDERSTORMS MOVE THROUGH THE AREA...THEN FOG WILL BE A THREAT
TONIGHT...ESPECIALLY IN VALLEY LOCATIONS. HAVE PUT FOG IN FOR THE TAF
STATIONS...HOWEVER IF PRECIPITATION IS NOT VERY WIDESPREAD...THEN THE
FOG IS NOT AS LIKELY AT SME AND LOZ. SOMETIMES AFTER A RAIN...THERE
IS A TEMPO FOG CONDITION THAT IS NOT VERY LONG LIVED...HOWEVER TRYING
TO TIME IT IS ALMOST IMPOSSIBLE THIS FAR OUT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...HAL
LONG TERM....MB
AVIATION...JJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
130 PM EDT TUE JUL 24 2012
.UPDATE...
ISSUED AT 1237 PM EDT TUE JUL 24 2012
MCS CONTINUES TO PROGRESS SOUTHWARD AND A WATCH HAS BEEN ISSUED FOR
ALL OF EASTERN KENTUCKY. THE MAIN THREAT WILL BE DAMAGING WINDS AS
THIS SYSTEM PUSHES SOUTH THROUGH THE AFTERNOON HOURS. EXPECTED
ARRIVAL TIMES IS FROM AROUND 1 PM IN THE NORTH TO 5 PM IN THE SOUTH
(NEAR THE TENNESSEE BORDER). STILL RECEIVING LOTS OF REPORTS OF
DAMAGE TO THE NORTH...SO THINGS COULD GET VERY INTERESTING IN OUR
NECK OF THE WOODS THIS AFTERNOON...ESPECIALLY WITH AREAS IN OUR
SOUTHWEST ALREADY VERY UNSTABLE WITH 3000J/KG OF SBCAPE.
UPDATE ISSUED AT 1216 PM EDT TUE JUL 24 2012
MCS IN SOUTHERN OHIO HAS TAKEN MORE OF A TURN TO THE SOUTH AND NOW IS
LOOKING LIKE IT MAY TAKE AIM ON MUCH OF EASTERN KENTUCKY. THIS SYSTEM
HAS BEEN PRODUCING PRETTY WIDESPREAD WIND DAMAGE AS IT HAS TRACKED
SOUTHWARD...SO IF IT HOLDS TOGETHER SPC MAY END UP ISSUING A WATCH
FOR OUR AREA. THIS SYSTEM MAY EXPAND A BIT TO THE WEST AS IT TRACKS
SOUTH WITH PLENTY OF INSTABILITY TO TO FEED OFF OF JUST TO THE WEST.
UPDATE ISSUED AT 1057 AM EDT TUE JUL 24 2012
COMPLEX OF SHOWERS AND STORMS CURRENTLY DROPPING SOUTHEAST ACROSS
EASTERN KENTUCKY. VERY COMPLEX PATTERN SETTING UP FOR THIS AFTERNOON.
IT LOOKS LIKE A DIFFERENTIAL TEMPERATURE BOUNDARY MAY BECOME
ESTABLISHED AFTER THIS MORNINGS ACTIVITY EXITS...CREATING A FOCUS FOR
NEW DEVELOPMENT BASICALLY ALONG AND SOUTHWEST OF A LINE FROM MOUNT
STERLING...THROUGH JACKSON...TO HARLAN. THUS...BELIEVE THE TARGETED
AREA WILL BE OUR MORE SOUTHWESTERN ZONES...CONTRARY TO THE PREVIOUS
FORECAST. THE HRRR SUPPORTS THIS IDEA WITH MOST OF THE ACTIVITY THIS
AFTERNOON AND EVENING IN OUR SOUTHWEST. THIS IS ALSO SUPPORTED BY AN
OUTFLOW BOUNDARY GENERATED FROM AN MCS CURRENTLY PUSHING INTO
SOUTHWEST OHIO. THIS WILL LIKELY PUSH THIS OUTFLOW BOUNDARY INTO
EASTERN KENTUCKY AS THIS SYSTEM TRACKS SOUTH AND EAST INTO WEST
VIRGINIA BY MIDDAY. THE AREA SEEING THE SHOWER AND STORM ACTIVITY
PRESENTLY WILL HAVE A TOUGH TIME REGENERATING ANY INSTABILITY...BUT
AREAS UNTAPPED TO THE SOUTHWEST WILL BE A DIFFERENT STORY. THUS...THE
SEVERE THREAT STILL SEEMS REASONABLE...BUT MAINLY FOR THE SOUTHWEST
ZONES. DAMAGING WINDS WILL BE THE PRIMARY THREAT. IT APPEARS THE MAIN
THREAT FOR SEVERE WEATHER WILL START AFTER 3 PM UNTIL 9 OR 10 PM.
UPDATE ISSUED AT 804 AM EDT TUE JUL 24 2012
UPDATED TO ALLOW FOR EARLIER ARRIVAL OF PRECIP POTENTIAL TODAY...WITH
SCATTERED SHOWERS AND STORMS ALREADY PRESENTLY DEVELOPING AND
ENTERING THE FORECAST AREA FROM THE NW.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 352 AM EDT TUE JUL 24 2012
THUNDERSTORMS WERE EXPLODING UPSTREAM OVER NORTH CENTRAL INDIANA AT
3 AM...WITH MORE OF THEM FURTHER NORTHWEST OVER THE UPPER MISSISSIPPI
VALLEY. THIS ACTIVITY INITIATED NEAR A FRONTAL BOUNDARY UNDER THE
PERIPHERY OF AN UPPER RIDGE. MODELS SHOW CONVECTION RUNNING AROUND
THE PERIPHERY OF THE RIDGE AND DEVELOPING/PROPAGATING INTO THE LOCAL
AREA DURING THE DAY. FORECAST SOUNDINGS SHOW AMPLE INSTABILITY
BUILDING DURING THE DAY...WITH CAPE LIKELY REACHING 2500-3000 J/KG.
ALTHOUGH SHEAR WILL NOT BE PHENOMENAL...IT SHOULD AT LEAST ALLOW FOR
ORGANIZATION...WITH A LIMITED AMOUNT OF BOTH SPEED AND DIRECTIONAL
SHEAR. IT WILL BE THROUGH A DEEP LAYER AND NOT CONCENTRATED IN THE
LOW LEVELS. ALSO FREEZING LEVELS WILL BE HIGH...IN THE NEIGHBORHOOD
OF 14-14.5K FEET. THUS...THE MAIN SEVERE THREAT LOOKS TO BE
WIND...BUT WITH STRONG INSTABILITY AND SOME POTENTIAL FOR STORM
ROTATION...HAIL ALSO NEEDS TO BE CONSIDERED.
THE SURFACE COLD FRONT IS EXPECTED TO SAG INTO KY TONIGHT...AND WOULD
NOT RULE OUT ADDITIONAL CONVECTION DEVELOPING. HOWEVER...IF
INSTABILITY IS SPENT ON EARLIER CONVECTION...CONFIDENCE IN COVERAGE
IS NOT AS HIGH DURING THE NIGHT.
ON WEDNESDAY...THE FRONT RETREATS TO THE NORTHEAST AND UPPER RIDGING
ALSO SHIFTS EASTWARD OVER THE AREA...WITH WINDS ALOFT WEAKENING. LOW
LEVEL MOISTURE SHOULD ALSO BE SLIGHTLY LESS...WHILE MID LEVEL TEMPS
WARM SLIGHTLY. ALL COMBINED...CONDITIONS WILL NOT BE AS FAVORABLE FOR
WIDESPREAD CONVECTION...AND HAVE USED LOWER POPS ONLY IN THE SLIGHT
CHANCE RANGE ON WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 400 AM EDT TUE JUL 24 2012
THE 24.00Z MODEL SUITE REMAINS IN FAIRLY GOOD AGREEMENT WITH THE
EVOLUTION OF THE UPPER LEVEL PATTERN THROUGH THE MAJORITY OF THE
PERIOD BUT DOES SHOW MINOR DIFFERENCES WITH HOW THINGS END UP TOWARDS
THE BEGINNING OF NEXT WEEK. AS SUCH...HAVE GENERALLY RELIED ON A
BLENDED CONSENSUS WITH A LITTLE MORE WEIGHT TO A SLIGHTLY MORE
REASONABLE 24.00Z ECMWF FOR SPECIFICS. WILL KICK OFF WITH ANY
LINGERING ACTIVITY FROM WEDNESDAY DWINDLING WITH THE USUAL LOSS OF
DAYTIME HEATING INFLUENCES AS ANOTHER LOW PRESSURE SYSTEM CURRENTLY
OVER THE CANADIAN ROCKIES BEGINS CARVING INTO THE NRN PLAINS AND
UPPER MIDWEST. THE SFC REFLECTION IS EXPECTED TO BEGIN TRAVERSING THE
GREAT LAKES WEDNESDAY NIGHT INTO THURSDAY WITH THE ASSOCIATED RAINS
ALONG THE COLD FRONT STILL OVER THE MIDWEST AND UPPER MS VALLEY.
CURRENT CONSENSUS BRINGS THE FORCING ASSOCIATED WITH THE FRONT INTO
THE LOCAL PICTURE LATE THURSDAY/THURSDAY NIGHT AND CONTINUING
THROUGH THE DAY ON FRIDAY AS FAVORABLE RIGHT ENTRANCE DYNAMICS OF AN
UPPER LEVEL JET GRACES THE OHIO VALLEY. HAVE TRENDED THE FORECAST
DRIER FOR MUCH OF THE AREA THROUGH MOST OF THURSDAY WITH POPS
PEAKING THURSDAY NIGHT AND FRIDAY. MODELS ARE FAIRLY PROGRESSIVE
WITH THE PARENT UPPER LEVEL TROF...PUSHING IT THROUGH THE COAL
FIELDS ON SATURDAY AS HEIGHTS BEGIN SLOWLY REBOUNDING OVER ERN KY IN
RESPONSE TO SFC HIGH PRESSURE BUILDING DOWN FROM THE GREAT LAKES
WHILE THE PERSISTENT UPPER LEVEL PLAINS RIDGE BEGINS REBUILDING AND
EXPANDING ACROSS THE MS VALLEY. THIS SHOULD PROVIDE FOR A RELATIVELY
QUIET...IF NOT DRY SPELL OVER MOST OF THE UPCOMING WEEKEND.
AS FOR TEMPERATURES...GIVEN THE RELATIVELY GOOD AGREEMENT AMONG THE
GUIDANCE SAW NO REASON TO DEVIATE TOO FAR FROM THE LATEST OFFERINGS
WHICH WERE STILL IN LINE WITH THE INHERITED NUMBERS. THIS RESULTED
IN TEMPS GENERALLY RUNNING ABOVE NORMAL EARLY IN THE PERIOD...WITH
HEAT INDICES ON THURSDAY QUITE POSSIBLY RETURNING TO THE TRIPLE
DIGITS AHEAD OF THE FRONT...BEFORE TURNING TOWARDS CLIMO ON FRIDAY
WITH HIGHS IN THE MID TO UPPER 80S AND OVERNIGHT LOWS GENERALLY IN
THE UPPER 60S THROUGH THE REMAINDER OF THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 130 PM EDT TUE JUL 24 2012
ALL OF EASTERN KENTUCKY IS UNDER A SEVERE THUNDERSTORM WATCH UNTIL
23Z. AS SUCH...THE THUNDERSTORMS OVER THE AREA ARE VERY DANGEROUS
AND THE POTENTIAL FOR LLWS IS GREATER THAN NORMAL. ONCE THE
THUNDERSTORMS MOVE THROUGH THE AREA...THEN FOG WILL BE A THREAT
TONIGHT...ESPECIALLY IN VALLEY LOCATIONS. HAVE PUT FOG IN FOR THE TAF
STATIONS...HOWEVER IF PRECIPITATION IS NOT VERY WIDESPREAD...THEN THE
FOG IS NOT AS LIKELY AT SME AND LOZ. SOMETIMES AFTER A RAIN...THERE
IS A TEMPO FOG CONDITION THAT IS NOT VERY LONG LIVED...HOWEVER TRYING
TO TIME IT IS ALMOST IMPOSSIBLE THIS FAR OUT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...HAL
LONG TERM....MB
AVIATION...JJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
1237 PM EDT TUE JUL 24 2012
.UPDATE...
ISSUED AT 1237 PM EDT TUE JUL 24 2012
MCS CONTINUES TO PROGRESS SOUTHWARD AND A WATCH HAS BEEN ISSUED FOR
ALL OF EASTERN KENTUCKY. THE MAIN THREAT WILL BE DAMAGING WINDS AS
THIS SYSTEM PUSHES SOUTH THROUGH THE AFTERNOON HOURS. EXPECTED
ARRIVAL TIMES IS FROM AROUND 1 PM IN THE NORTH TO 5 PM IN THE SOUTH
(NEAR THE TENNESSEE BORDER). STILL RECEIVING LOTS OF REPORTS OF
DAMAGE TO THE NORTH...SO THINGS COULD GET VERY INTERESTING IN OUR
NECK OF THE WOODS THIS AFTERNOON...ESPECIALLY WITH AREAS IN OUR
SOUTHWEST ALREADY VERY UNSTABLE WITH 3000J/KG OF SBCAPE.
UPDATE ISSUED AT 1216 PM EDT TUE JUL 24 2012
MCS IN SOUTHERN OHIO HAS TAKEN MORE OF A TURN TO THE SOUTH AND NOW IS
LOOKING LIKE IT MAY TAKE AIM ON MUCH OF EASTERN KENTUCKY. THIS SYSTEM
HAS BEEN PRODUCING PRETTY WIDESPREAD WIND DAMAGE AS IT HAS TRACKED
SOUTHWARD...SO IF IT HOLDS TOGETHER SPC MAY END UP ISSUING A WATCH
FOR OUR AREA. THIS SYSTEM MAY EXPAND A BIT TO THE WEST AS IT TRACKS
SOUTH WITH PLENTY OF INSTABILITY TO TO FEED OFF OF JUST TO THE WEST.
UPDATE ISSUED AT 1057 AM EDT TUE JUL 24 2012
COMPLEX OF SHOWERS AND STORMS CURRENTLY DROPPING SOUTHEAST ACROSS
EASTERN KENTUCKY. VERY COMPLEX PATTERN SETTING UP FOR THIS AFTERNOON.
IT LOOKS LIKE A DIFFERENTIAL TEMPERATURE BOUNDARY MAY BECOME
ESTABLISHED AFTER THIS MORNINGS ACTIVITY EXITS...CREATING A FOCUS FOR
NEW DEVELOPMENT BASICALLY ALONG AND SOUTHWEST OF A LINE FROM MOUNT
STERLING...THROUGH JACKSON...TO HARLAN. THUS...BELIEVE THE TARGETED
AREA WILL BE OUR MORE SOUTHWESTERN ZONES...CONTRARY TO THE PREVIOUS
FORECAST. THE HRRR SUPPORTS THIS IDEA WITH MOST OF THE ACTIVITY THIS
AFTERNOON AND EVENING IN OUR SOUTHWEST. THIS IS ALSO SUPPORTED BY AN
OUTFLOW BOUNDARY GENERATED FROM AN MCS CURRENTLY PUSHING INTO
SOUTHWEST OHIO. THIS WILL LIKELY PUSH THIS OUTFLOW BOUNDARY INTO
EASTERN KENTUCKY AS THIS SYSTEM TRACKS SOUTH AND EAST INTO WEST
VIRGINIA BY MIDDAY. THE AREA SEEING THE SHOWER AND STORM ACTIVITY
PRESENTLY WILL HAVE A TOUGH TIME REGENERATING ANY INSTABILITY...BUT
AREAS UNTAPPED TO THE SOUTHWEST WILL BE A DIFFERENT STORY. THUS...THE
SEVERE THREAT STILL SEEMS REASONABLE...BUT MAINLY FOR THE SOUTHWEST
ZONES. DAMAGING WINDS WILL BE THE PRIMARY THREAT. IT APPEARS THE MAIN
THREAT FOR SEVERE WEATHER WILL START AFTER 3 PM UNTIL 9 OR 10 PM.
UPDATE ISSUED AT 804 AM EDT TUE JUL 24 2012
UPDATED TO ALLOW FOR EARLIER ARRIVAL OF PRECIP POTENTIAL TODAY...WITH
SCATTERED SHOWERS AND STORMS ALREADY PRESENTLY DEVELOPING AND
ENTERING THE FORECAST AREA FROM THE NW.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 352 AM EDT TUE JUL 24 2012
THUNDERSTORMS WERE EXPLODING UPSTREAM OVER NORTH CENTRAL INDIANA AT
3 AM...WITH MORE OF THEM FURTHER NORTHWEST OVER THE UPPER MISSISSIPPI
VALLEY. THIS ACTIVITY INITIATED NEAR A FRONTAL BOUNDARY UNDER THE
PERIPHERY OF AN UPPER RIDGE. MODELS SHOW CONVECTION RUNNING AROUND
THE PERIPHERY OF THE RIDGE AND DEVELOPING/PROPAGATING INTO THE LOCAL
AREA DURING THE DAY. FORECAST SOUNDINGS SHOW AMPLE INSTABILITY
BUILDING DURING THE DAY...WITH CAPE LIKELY REACHING 2500-3000 J/KG.
ALTHOUGH SHEAR WILL NOT BE PHENOMENAL...IT SHOULD AT LEAST ALLOW FOR
ORGANIZATION...WITH A LIMITED AMOUNT OF BOTH SPEED AND DIRECTIONAL
SHEAR. IT WILL BE THROUGH A DEEP LAYER AND NOT CONCENTRATED IN THE
LOW LEVELS. ALSO FREEZING LEVELS WILL BE HIGH...IN THE NEIGHBORHOOD
OF 14-14.5K FEET. THUS...THE MAIN SEVERE THREAT LOOKS TO BE
WIND...BUT WITH STRONG INSTABILITY AND SOME POTENTIAL FOR STORM
ROTATION...HAIL ALSO NEEDS TO BE CONSIDERED.
THE SURFACE COLD FRONT IS EXPECTED TO SAG INTO KY TONIGHT...AND WOULD
NOT RULE OUT ADDITIONAL CONVECTION DEVELOPING. HOWEVER...IF
INSTABILITY IS SPENT ON EARLIER CONVECTION...CONFIDENCE IN COVERAGE
IS NOT AS HIGH DURING THE NIGHT.
ON WEDNESDAY...THE FRONT RETREATS TO THE NORTHEAST AND UPPER RIDGING
ALSO SHIFTS EASTWARD OVER THE AREA...WITH WINDS ALOFT WEAKENING. LOW
LEVEL MOISTURE SHOULD ALSO BE SLIGHTLY LESS...WHILE MID LEVEL TEMPS
WARM SLIGHTLY. ALL COMBINED...CONDITIONS WILL NOT BE AS FAVORABLE FOR
WIDESPREAD CONVECTION...AND HAVE USED LOWER POPS ONLY IN THE SLIGHT
CHANCE RANGE ON WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 400 AM EDT TUE JUL 24 2012
THE 24.00Z MODEL SUITE REMAINS IN FAIRLY GOOD AGREEMENT WITH THE
EVOLUTION OF THE UPPER LEVEL PATTERN THROUGH THE MAJORITY OF THE
PERIOD BUT DOES SHOW MINOR DIFFERENCES WITH HOW THINGS END UP TOWARDS
THE BEGINNING OF NEXT WEEK. AS SUCH...HAVE GENERALLY RELIED ON A
BLENDED CONSENSUS WITH A LITTLE MORE WEIGHT TO A SLIGHTLY MORE
REASONABLE 24.00Z ECMWF FOR SPECIFICS. WILL KICK OFF WITH ANY
LINGERING ACTIVITY FROM WEDNESDAY DWINDLING WITH THE USUAL LOSS OF
DAYTIME HEATING INFLUENCES AS ANOTHER LOW PRESSURE SYSTEM CURRENTLY
OVER THE CANADIAN ROCKIES BEGINS CARVING INTO THE NRN PLAINS AND
UPPER MIDWEST. THE SFC REFLECTION IS EXPECTED TO BEGIN TRAVERSING THE
GREAT LAKES WEDNESDAY NIGHT INTO THURSDAY WITH THE ASSOCIATED RAINS
ALONG THE COLD FRONT STILL OVER THE MIDWEST AND UPPER MS VALLEY.
CURRENT CONSENSUS BRINGS THE FORCING ASSOCIATED WITH THE FRONT INTO
THE LOCAL PICTURE LATE THURSDAY/THURSDAY NIGHT AND CONTINUING
THROUGH THE DAY ON FRIDAY AS FAVORABLE RIGHT ENTRANCE DYNAMICS OF AN
UPPER LEVEL JET GRACES THE OHIO VALLEY. HAVE TRENDED THE FORECAST
DRIER FOR MUCH OF THE AREA THROUGH MOST OF THURSDAY WITH POPS
PEAKING THURSDAY NIGHT AND FRIDAY. MODELS ARE FAIRLY PROGRESSIVE
WITH THE PARENT UPPER LEVEL TROF...PUSHING IT THROUGH THE COAL
FIELDS ON SATURDAY AS HEIGHTS BEGIN SLOWLY REBOUNDING OVER ERN KY IN
RESPONSE TO SFC HIGH PRESSURE BUILDING DOWN FROM THE GREAT LAKES
WHILE THE PERSISTENT UPPER LEVEL PLAINS RIDGE BEGINS REBUILDING AND
EXPANDING ACROSS THE MS VALLEY. THIS SHOULD PROVIDE FOR A RELATIVELY
QUIET...IF NOT DRY SPELL OVER MOST OF THE UPCOMING WEEKEND.
AS FOR TEMPERATURES...GIVEN THE RELATIVELY GOOD AGREEMENT AMONG THE
GUIDANCE SAW NO REASON TO DEVIATE TOO FAR FROM THE LATEST OFFERINGS
WHICH WERE STILL IN LINE WITH THE INHERITED NUMBERS. THIS RESULTED
IN TEMPS GENERALLY RUNNING ABOVE NORMAL EARLY IN THE PERIOD...WITH
HEAT INDICES ON THURSDAY QUITE POSSIBLY RETURNING TO THE TRIPLE
DIGITS AHEAD OF THE FRONT...BEFORE TURNING TOWARDS CLIMO ON FRIDAY
WITH HIGHS IN THE MID TO UPPER 80S AND OVERNIGHT LOWS GENERALLY IN
THE UPPER 60S THROUGH THE REMAINDER OF THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 804 AM EDT TUE JUL 24 2012
SCATTERED SHOWERS AND THUNDERSTORMS WERE ENTERING THE FORECAST AREA
FROM THE NORTHWEST AT THE START OF THE PERIOD...AND WILL CONTINUE TO
INCREASE IN COVERAGE. THEY WILL BRING LOCALIZED IFR TODAY. IF ENOUGH
DESTABILIZATION CAN OCCUR...SOME OF THE STORMS MAY BRING STRONG WINDS
AND POSSIBLY HAIL IN THE AFTERNOON. WILL EXPECT A RELATIVE LULL IN
PRECIP LATE THIS EVENING AND OVERNIGHT. HOWEVER...FOG WILL BE A
THREAT TONIGHT...ESPECIALLY IN VALLEY LOCATIONS IF CLOUDS BREAK UP.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...HAL
LONG TERM....MB
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
1216 PM EDT TUE JUL 24 2012
.UPDATE...
ISSUED AT 1216 PM EDT TUE JUL 24 2012
MCS IN SOUTHERN OHIO HAS TAKEN MORE OF A TURN TO THE SOUTH AND NOW IS
LOOKING LIKE IT MAY TAKE AIM ON MUCH OF EASTERN KENTUCKY. THIS SYSTEM
HAS BEEN PRODUCING PRETTY WIDESPREAD WIND DAMAGE AS IT HAS TRACKED
SOUTHWARD...SO IF IT HOLDS TOGETHER SPC MAY END UP ISSUING A WATCH
FOR OUR AREA. THIS SYSTEM MAY EXPAND A BIT TO THE WEST AS IT TRACKS
SOUTH WITH PLENTY OF INSTABILITY TO TO FEED OFF OF JUST TO THE WEST.
UPDATE ISSUED AT 1057 AM EDT TUE JUL 24 2012
COMPLEX OF SHOWERS AND STORMS CURRENTLY DROPPING SOUTHEAST ACROSS
EASTERN KENTUCKY. VERY COMPLEX PATTERN SETTING UP FOR THIS AFTERNOON.
IT LOOKS LIKE A DIFFERENTIAL TEMPERATURE BOUNDARY MAY BECOME
ESTABLISHED AFTER THIS MORNINGS ACTIVITY EXITS...CREATING A FOCUS FOR
NEW DEVELOPMENT BASICALLY ALONG AND SOUTHWEST OF A LINE FROM MOUNT
STERLING...THROUGH JACKSON...TO HARLAN. THUS...BELIEVE THE TARGETED
AREA WILL BE OUR MORE SOUTHWESTERN ZONES...CONTRARY TO THE PREVIOUS
FORECAST. THE HRRR SUPPORTS THIS IDEA WITH MOST OF THE ACTIVITY THIS
AFTERNOON AND EVENING IN OUR SOUTHWEST. THIS IS ALSO SUPPORTED BY AN
OUTFLOW BOUNDARY GENERATED FROM AN MCS CURRENTLY PUSHING INTO
SOUTHWEST OHIO. THIS WILL LIKELY PUSH THIS OUTFLOW BOUNDARY INTO
EASTERN KENTUCKY AS THIS SYSTEM TRACKS SOUTH AND EAST INTO WEST
VIRGINIA BY MIDDAY. THE AREA SEEING THE SHOWER AND STORM ACTIVITY
PRESENTLY WILL HAVE A TOUGH TIME REGENERATING ANY INSTABILITY...BUT
AREAS UNTAPPED TO THE SOUTHWEST WILL BE A DIFFERENT STORY. THUS...THE
SEVERE THREAT STILL SEEMS REASONABLE...BUT MAINLY FOR THE SOUTHWEST
ZONES. DAMAGING WINDS WILL BE THE PRIMARY THREAT. IT APPEARS THE MAIN
THREAT FOR SEVERE WEATHER WILL START AFTER 3 PM UNTIL 9 OR 10 PM.
UPDATE ISSUED AT 804 AM EDT TUE JUL 24 2012
UPDATED TO ALLOW FOR EARLIER ARRIVAL OF PRECIP POTENTIAL TODAY...WITH
SCATTERED SHOWERS AND STORMS ALREADY PRESENTLY DEVELOPING AND
ENTERING THE FORECAST AREA FROM THE NW.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 352 AM EDT TUE JUL 24 2012
THUNDERSTORMS WERE EXPLODING UPSTREAM OVER NORTH CENTRAL INDIANA AT
3 AM...WITH MORE OF THEM FURTHER NORTHWEST OVER THE UPPER MISSISSIPPI
VALLEY. THIS ACTIVITY INITIATED NEAR A FRONTAL BOUNDARY UNDER THE
PERIPHERY OF AN UPPER RIDGE. MODELS SHOW CONVECTION RUNNING AROUND
THE PERIPHERY OF THE RIDGE AND DEVELOPING/PROPAGATING INTO THE LOCAL
AREA DURING THE DAY. FORECAST SOUNDINGS SHOW AMPLE INSTABILITY
BUILDING DURING THE DAY...WITH CAPE LIKELY REACHING 2500-3000 J/KG.
ALTHOUGH SHEAR WILL NOT BE PHENOMENAL...IT SHOULD AT LEAST ALLOW FOR
ORGANIZATION...WITH A LIMITED AMOUNT OF BOTH SPEED AND DIRECTIONAL
SHEAR. IT WILL BE THROUGH A DEEP LAYER AND NOT CONCENTRATED IN THE
LOW LEVELS. ALSO FREEZING LEVELS WILL BE HIGH...IN THE NEIGHBORHOOD
OF 14-14.5K FEET. THUS...THE MAIN SEVERE THREAT LOOKS TO BE
WIND...BUT WITH STRONG INSTABILITY AND SOME POTENTIAL FOR STORM
ROTATION...HAIL ALSO NEEDS TO BE CONSIDERED.
THE SURFACE COLD FRONT IS EXPECTED TO SAG INTO KY TONIGHT...AND WOULD
NOT RULE OUT ADDITIONAL CONVECTION DEVELOPING. HOWEVER...IF
INSTABILITY IS SPENT ON EARLIER CONVECTION...CONFIDENCE IN COVERAGE
IS NOT AS HIGH DURING THE NIGHT.
ON WEDNESDAY...THE FRONT RETREATS TO THE NORTHEAST AND UPPER RIDGING
ALSO SHIFTS EASTWARD OVER THE AREA...WITH WINDS ALOFT WEAKENING. LOW
LEVEL MOISTURE SHOULD ALSO BE SLIGHTLY LESS...WHILE MID LEVEL TEMPS
WARM SLIGHTLY. ALL COMBINED...CONDITIONS WILL NOT BE AS FAVORABLE FOR
WIDESPREAD CONVECTION...AND HAVE USED LOWER POPS ONLY IN THE SLIGHT
CHANCE RANGE ON WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 400 AM EDT TUE JUL 24 2012
THE 24.00Z MODEL SUITE REMAINS IN FAIRLY GOOD AGREEMENT WITH THE
EVOLUTION OF THE UPPER LEVEL PATTERN THROUGH THE MAJORITY OF THE
PERIOD BUT DOES SHOW MINOR DIFFERENCES WITH HOW THINGS END UP TOWARDS
THE BEGINNING OF NEXT WEEK. AS SUCH...HAVE GENERALLY RELIED ON A
BLENDED CONSENSUS WITH A LITTLE MORE WEIGHT TO A SLIGHTLY MORE
REASONABLE 24.00Z ECMWF FOR SPECIFICS. WILL KICK OFF WITH ANY
LINGERING ACTIVITY FROM WEDNESDAY DWINDLING WITH THE USUAL LOSS OF
DAYTIME HEATING INFLUENCES AS ANOTHER LOW PRESSURE SYSTEM CURRENTLY
OVER THE CANADIAN ROCKIES BEGINS CARVING INTO THE NRN PLAINS AND
UPPER MIDWEST. THE SFC REFLECTION IS EXPECTED TO BEGIN TRAVERSING THE
GREAT LAKES WEDNESDAY NIGHT INTO THURSDAY WITH THE ASSOCIATED RAINS
ALONG THE COLD FRONT STILL OVER THE MIDWEST AND UPPER MS VALLEY.
CURRENT CONSENSUS BRINGS THE FORCING ASSOCIATED WITH THE FRONT INTO
THE LOCAL PICTURE LATE THURSDAY/THURSDAY NIGHT AND CONTINUING
THROUGH THE DAY ON FRIDAY AS FAVORABLE RIGHT ENTRANCE DYNAMICS OF AN
UPPER LEVEL JET GRACES THE OHIO VALLEY. HAVE TRENDED THE FORECAST
DRIER FOR MUCH OF THE AREA THROUGH MOST OF THURSDAY WITH POPS
PEAKING THURSDAY NIGHT AND FRIDAY. MODELS ARE FAIRLY PROGRESSIVE
WITH THE PARENT UPPER LEVEL TROF...PUSHING IT THROUGH THE COAL
FIELDS ON SATURDAY AS HEIGHTS BEGIN SLOWLY REBOUNDING OVER ERN KY IN
RESPONSE TO SFC HIGH PRESSURE BUILDING DOWN FROM THE GREAT LAKES
WHILE THE PERSISTENT UPPER LEVEL PLAINS RIDGE BEGINS REBUILDING AND
EXPANDING ACROSS THE MS VALLEY. THIS SHOULD PROVIDE FOR A RELATIVELY
QUIET...IF NOT DRY SPELL OVER MOST OF THE UPCOMING WEEKEND.
AS FOR TEMPERATURES...GIVEN THE RELATIVELY GOOD AGREEMENT AMONG THE
GUIDANCE SAW NO REASON TO DEVIATE TOO FAR FROM THE LATEST OFFERINGS
WHICH WERE STILL IN LINE WITH THE INHERITED NUMBERS. THIS RESULTED
IN TEMPS GENERALLY RUNNING ABOVE NORMAL EARLY IN THE PERIOD...WITH
HEAT INDICES ON THURSDAY QUITE POSSIBLY RETURNING TO THE TRIPLE
DIGITS AHEAD OF THE FRONT...BEFORE TURNING TOWARDS CLIMO ON FRIDAY
WITH HIGHS IN THE MID TO UPPER 80S AND OVERNIGHT LOWS GENERALLY IN
THE UPPER 60S THROUGH THE REMAINDER OF THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 804 AM EDT TUE JUL 24 2012
SCATTERED SHOWERS AND THUNDERSTORMS WERE ENTERING THE FORECAST AREA
FROM THE NORTHWEST AT THE START OF THE PERIOD...AND WILL CONTINUE TO
INCREASE IN COVERAGE. THEY WILL BRING LOCALIZED IFR TODAY. IF ENOUGH
DESTABILIZATION CAN OCCUR...SOME OF THE STORMS MAY BRING STRONG WINDS
AND POSSIBLY HAIL IN THE AFTERNOON. WILL EXPECT A RELATIVE LULL IN
PRECIP LATE THIS EVENING AND OVERNIGHT. HOWEVER...FOG WILL BE A
THREAT TONIGHT...ESPECIALLY IN VALLEY LOCATIONS IF CLOUDS BREAK UP.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...HAL
LONG TERM....MB
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
1057 AM EDT TUE JUL 24 2012
.UPDATE...
ISSUED AT 1057 AM EDT TUE JUL 24 2012
COMPLEX OF SHOWERS AND STORMS CURRENTLY DROPPING SOUTHEAST ACROSS
EASTERN KENTUCKY. VERY COMPLEX PATTERN SETTING UP FOR THIS AFTERNOON.
IT LOOKS LIKE A DIFFERENTIAL TEMPERATURE BOUNDARY MAY BECOME
ESTABLISHED AFTER THIS MORNINGS ACTIVITY EXITS...CREATING A FOCUS FOR
NEW DEVELOPMENT BASICALLY ALONG AND SOUTHWEST OF A LINE FROM MOUNT
STERLING...THROUGH JACKSON...TO HARLAN. THUS...BELIEVE THE TARGETED
AREA WILL BE OUR MORE SOUTHWESTERN ZONES...CONTRARY TO THE PREVIOUS
FORECAST. THE HRRR SUPPORTS THIS IDEA WITH MOST OF THE ACTIVITY THIS
AFTERNOON AND EVENING IN OUR SOUTHWEST. THIS IS ALSO SUPPORTED BY AN
OUTFLOW BOUNDARY GENERATED FROM AN MCS CURRENTLY PUSHING INTO
SOUTHWEST OHIO. THIS WILL LIKELY PUSH THIS OUTFLOW BOUNDARY INTO
EASTERN KENTUCKY AS THIS SYSTEM TRACKS SOUTH AND EAST INTO WEST
VIRGINIA BY MIDDAY. THE AREA SEEING THE SHOWER AND STORM ACTIVITY
PRESENTLY WILL HAVE A TOUGH TIME REGENERATING ANY INSTABILITY...BUT
AREAS UNTAPPED TO THE SOUTHWEST WILL BE A DIFFERENT STORY. THUS...THE
SEVERE THREAT STILL SEEMS REASONABLE...BUT MAINLY FOR THE SOUTHWEST
ZONES. DAMAGING WINDS WILL BE THE PRIMARY THREAT. IT APPEARS THE MAIN
THREAT FOR SEVERE WEATHER WILL START AFTER 3 PM UNTIL 9 OR 10 PM.
UPDATE ISSUED AT 804 AM EDT TUE JUL 24 2012
UPDATED TO ALLOW FOR EARLIER ARRIVAL OF PRECIP POTENTIAL TODAY...WITH
SCATTERED SHOWERS AND STORMS ALREADY PRESENTLY DEVELOPING AND
ENTERING THE FORECAST AREA FROM THE NW.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 352 AM EDT TUE JUL 24 2012
THUNDERSTORMS WERE EXPLODING UPSTREAM OVER NORTH CENTRAL INDIANA AT
3 AM...WITH MORE OF THEM FURTHER NORTHWEST OVER THE UPPER MISSISSIPPI
VALLEY. THIS ACTIVITY INITIATED NEAR A FRONTAL BOUNDARY UNDER THE
PERIPHERY OF AN UPPER RIDGE. MODELS SHOW CONVECTION RUNNING AROUND
THE PERIPHERY OF THE RIDGE AND DEVELOPING/PROPAGATING INTO THE LOCAL
AREA DURING THE DAY. FORECAST SOUNDINGS SHOW AMPLE INSTABILITY
BUILDING DURING THE DAY...WITH CAPE LIKELY REACHING 2500-3000 J/KG.
ALTHOUGH SHEAR WILL NOT BE PHENOMENAL...IT SHOULD AT LEAST ALLOW FOR
ORGANIZATION...WITH A LIMITED AMOUNT OF BOTH SPEED AND DIRECTIONAL
SHEAR. IT WILL BE THROUGH A DEEP LAYER AND NOT CONCENTRATED IN THE
LOW LEVELS. ALSO FREEZING LEVELS WILL BE HIGH...IN THE NEIGHBORHOOD
OF 14-14.5K FEET. THUS...THE MAIN SEVERE THREAT LOOKS TO BE
WIND...BUT WITH STRONG INSTABILITY AND SOME POTENTIAL FOR STORM
ROTATION...HAIL ALSO NEEDS TO BE CONSIDERED.
THE SURFACE COLD FRONT IS EXPECTED TO SAG INTO KY TONIGHT...AND WOULD
NOT RULE OUT ADDITIONAL CONVECTION DEVELOPING. HOWEVER...IF
INSTABILITY IS SPENT ON EARLIER CONVECTION...CONFIDENCE IN COVERAGE
IS NOT AS HIGH DURING THE NIGHT.
ON WEDNESDAY...THE FRONT RETREATS TO THE NORTHEAST AND UPPER RIDGING
ALSO SHIFTS EASTWARD OVER THE AREA...WITH WINDS ALOFT WEAKENING. LOW
LEVEL MOISTURE SHOULD ALSO BE SLIGHTLY LESS...WHILE MID LEVEL TEMPS
WARM SLIGHTLY. ALL COMBINED...CONDITIONS WILL NOT BE AS FAVORABLE FOR
WIDESPREAD CONVECTION...AND HAVE USED LOWER POPS ONLY IN THE SLIGHT
CHANCE RANGE ON WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 400 AM EDT TUE JUL 24 2012
THE 24.00Z MODEL SUITE REMAINS IN FAIRLY GOOD AGREEMENT WITH THE
EVOLUTION OF THE UPPER LEVEL PATTERN THROUGH THE MAJORITY OF THE
PERIOD BUT DOES SHOW MINOR DIFFERENCES WITH HOW THINGS END UP TOWARDS
THE BEGINNING OF NEXT WEEK. AS SUCH...HAVE GENERALLY RELIED ON A
BLENDED CONSENSUS WITH A LITTLE MORE WEIGHT TO A SLIGHTLY MORE
REASONABLE 24.00Z ECMWF FOR SPECIFICS. WILL KICK OFF WITH ANY
LINGERING ACTIVITY FROM WEDNESDAY DWINDLING WITH THE USUAL LOSS OF
DAYTIME HEATING INFLUENCES AS ANOTHER LOW PRESSURE SYSTEM CURRENTLY
OVER THE CANADIAN ROCKIES BEGINS CARVING INTO THE NRN PLAINS AND
UPPER MIDWEST. THE SFC REFLECTION IS EXPECTED TO BEGIN TRAVERSING THE
GREAT LAKES WEDNESDAY NIGHT INTO THURSDAY WITH THE ASSOCIATED RAINS
ALONG THE COLD FRONT STILL OVER THE MIDWEST AND UPPER MS VALLEY.
CURRENT CONSENSUS BRINGS THE FORCING ASSOCIATED WITH THE FRONT INTO
THE LOCAL PICTURE LATE THURSDAY/THURSDAY NIGHT AND CONTINUING
THROUGH THE DAY ON FRIDAY AS FAVORABLE RIGHT ENTRANCE DYNAMICS OF AN
UPPER LEVEL JET GRACES THE OHIO VALLEY. HAVE TRENDED THE FORECAST
DRIER FOR MUCH OF THE AREA THROUGH MOST OF THURSDAY WITH POPS
PEAKING THURSDAY NIGHT AND FRIDAY. MODELS ARE FAIRLY PROGRESSIVE
WITH THE PARENT UPPER LEVEL TROF...PUSHING IT THROUGH THE COAL
FIELDS ON SATURDAY AS HEIGHTS BEGIN SLOWLY REBOUNDING OVER ERN KY IN
RESPONSE TO SFC HIGH PRESSURE BUILDING DOWN FROM THE GREAT LAKES
WHILE THE PERSISTENT UPPER LEVEL PLAINS RIDGE BEGINS REBUILDING AND
EXPANDING ACROSS THE MS VALLEY. THIS SHOULD PROVIDE FOR A RELATIVELY
QUIET...IF NOT DRY SPELL OVER MOST OF THE UPCOMING WEEKEND.
AS FOR TEMPERATURES...GIVEN THE RELATIVELY GOOD AGREEMENT AMONG THE
GUIDANCE SAW NO REASON TO DEVIATE TOO FAR FROM THE LATEST OFFERINGS
WHICH WERE STILL IN LINE WITH THE INHERITED NUMBERS. THIS RESULTED
IN TEMPS GENERALLY RUNNING ABOVE NORMAL EARLY IN THE PERIOD...WITH
HEAT INDICES ON THURSDAY QUITE POSSIBLY RETURNING TO THE TRIPLE
DIGITS AHEAD OF THE FRONT...BEFORE TURNING TOWARDS CLIMO ON FRIDAY
WITH HIGHS IN THE MID TO UPPER 80S AND OVERNIGHT LOWS GENERALLY IN
THE UPPER 60S THROUGH THE REMAINDER OF THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 804 AM EDT TUE JUL 24 2012
SCATTERED SHOWERS AND THUNDERSTORMS WERE ENTERING THE FORECAST AREA
FROM THE NORTHWEST AT THE START OF THE PERIOD...AND WILL CONTINUE TO
INCREASE IN COVERAGE. THEY WILL BRING LOCALIZED IFR TODAY. IF ENOUGH
DESTABILIZATION CAN OCCUR...SOME OF THE STORMS MAY BRING STRONG WINDS
AND POSSIBLY HAIL IN THE AFTERNOON. WILL EXPECT A RELATIVE LULL IN
PRECIP LATE THIS EVENING AND OVERNIGHT. HOWEVER...FOG WILL BE A
THREAT TONIGHT...ESPECIALLY IN VALLEY LOCATIONS IF CLOUDS BREAK UP.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...HAL
LONG TERM....MB
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
150 AM EDT TUE JUL 24 2012
.UPDATE...
ISSUED AT 150 AM EDT TUE JUL 24 2012
WITH 06Z TAFS...HAVE UPDATED SKY CONDITION GRIDS BASED ON 00Z MODEL
RUNS.
UPDATE ISSUED AT 810 PM EDT MON JUL 23 2012
RAN ANOTHER UPDATE TO KEEP THE GRIDS IN CHECK WITH THE CURRENT
CONDITIONS AND TRENDS. THE ATMOSPHERE REMAINS UNSTABLE...BUT ANY
TRIGGERS FOR ARE LACKING. WILL BE WATCHING FOR ANY DEVELOPMENT WITH
THE CONVECTION TRYING TO POP UP OVER SOUTHEAST INDIANA...BUT
INSTABILITY OVER EAST KENTUCKY WILL BE DIMINISHING THROUGH THE
EVENING AND OVERNIGHT. ACCORDINGLY...WILL KEEP POPS LOW THROUGH THE
NIGHT...BUT NOT COMPLETELY ZEROED OUT. ALSO ADDED A TOUCH OF DEEPER
VALLEY FOG TO THE GRIDS. UPDATES TO NDFD...THE WEB AND ZONES WILL BE
ISSUED SHORTLY.
UPDATE ISSUED AT 545 PM EDT MON JUL 23 2012
DID A QUICK UPDATE TO THE GRIDS AND WEB FORECAST TO ACCOUNT FOR
CONVECTIVE TRENDS...OR LACK THERE OF...INTO THE EVENING. ALSO UPDATED
THE SKY...TEMPERATURE AND DEW POINT GRIDS FOR THEIR CURRENT
OBSERVATIONS AND TRENDS. UPDATES SENT TO THE WEB AND NDFD...THE
ZONES ARE STILL FINE.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 313 PM EDT MON JUL 23 2012
HIGH PRESSURE RIDGE CONTINUES TO DOMINATE TO OUR WEST AND
SOUTH...WITH EASTERN KENTUCKY SITTING ON THE PERIPHERALS. THIS
MEANS...OUR AREA REMAINS A FOCUS OF CONCERN FOR REPEATED CHANCES FOR
SHOWERS AND THUNDERSTORMS OVER THE NEXT 24 TO 48 HOURS. A FEW
ISOLATED SHOWERS HANGING ON NEAR THE VIRGINIA BORDER THIS
AFTERNOON...BUT THESE SHOULD EXIT INTO VIRGINIA IN THE NEXT HOUR OR
SO. A LULL IS EXPECTED INTO THIS EVENING. HOWEVER...A SHORTWAVE
TROUGH IS PUSHING INTO SOUTHERN OHIO AND INDIANA. PRESENTLY...NOT MUCH
ACTIVITY ASSOCIATED WITH THIS FEATURE. IN FACT...THE SHOWER ACTIVITY
EARLIER HAS ALMOST COMPLETELY DRIED UP. STILL SOME QUESTION ON HOW
MUCH DEVELOPMENT WILL OCCUR AS THIS TROUGH AXIS PUSHES SOUTH INTO
A MORE UNSTABLE AIR MASS. IT IS POSSIBLE WE COULD SEE A FEW ISOLATED
SUPERCELLS CAPABLE OF DAMAGING WINDS THROUGH 9 OR 10 PM. THE HRRR HAS
HELD CONSISTENT WITH THE IDEA OF ISOLATED SUPERCELLS DEVELOPING AFTER
8 PM...AND TRACKING INTO AREAS NORTH OF I-64 AROUND 9 OR 10 PM. THERE
IS SOME WEAK DIRECTIONAL SHEAR TO SUPPORT THIS IDEA. THUS...PLAN TO
INCLUDE A SLIGHT CHANCE OF SHOWERS AND STORMS THROUGH LATE EVENING.
THIS ACTIVITY WILL GRADUALLY WEAKEN AS IT PUSHES FURTHER SOUTH...SO
THE SECOND HALF OF THE NIGHT SHOULD BE MAINLY DRY.
MOVING ON TO TOMORROW...IT LOOKS LIKE ANOTHER DECENT WAVE WILL DROP
SOUTHEAST FROM MIDDAY INTO THE EVENING HOURS...PRODUCING AN EVEN
BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS. WIND SHEAR WILL BE EVEN
BETTER TOMORROW WITH 700MB WINDS AROUND 30 KNOTS AND 500MB WINDS 35
KNOTS. THERE IS SOME DIRECTIONAL SHEAR AS WELL. THUS...SEVERE THREAT
LOOKS PRETTY GOOD TOMORROW FOR SOME DAMAGING WINDS. THE BIGGER
CONCERN COULD BE SOME LOCALLY HEAVY RAIN WITH PW VALUES AROUND 2
INCHES AND FREEZING LEVELS OVER 15KFT. ANY STORMS THAT HIT THE SAME
AREAS COULD LEAD TO FLASH FLOODING. NOT CONFIDENT ENOUGH TO GO WITH A
WATCH...BUT CERTAINLY SOMETHING TO KEEP AN EYE ON.
BY TOMORROW NIGHT...THE FIRST ROUND OF CONVECTION WILL DEPART...BUT
WE WILL REMAIN IN A FAVORABLE SPOT FOR MORE DEVELOPMENT
UPSTREAM...WITH PERHAPS A NOCTURNAL MCS DEVELOPING AND TRACKING INTO
OUR AREA. THUS...WILL KEEP SOME CHANCE POPS GOING THROUGH TOMORROW
NIGHT.
TEMPERATURES WILL REMAIN MILD WITH HIGHS ON TUESDAY CLIMBING TO
AROUND 90 AND LOWS TONIGHT AND TOMORROW NIGHT IN THE LOWER 70S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 341 PM EDT MON JUL 23 2012
THE MODELS START OUT IN VERY GOOD AGREEMENT WITH A FAIRLY ZONAL FLOW
NORTH OF 40 DEGREES AND UPPER RIDGING DOMINATES SOUTH OF 40 DEGREES.
THE SYSTEM TO WATCH IS AN UPPER LOW IN SOUTHWEST MANITOBA WITH A
TROUGH EXTENDING INTO THE CENTRAL PLAINS. THIS UPPER LOW STARTS
MOVING SLOWLY TO THE EAST SOUTHEAST AND AS IT DOES...IT IS PUSHING
THE POLAR FRONT TO THE SOUTH. THE TROUGH CONTINUE PUSHING TO THE ESE
AND WILL PUSH A FRONT ACROSS THE COAL FIELDS ON FRIDAY. THIS FRONT
WILL STAY JUST SOUTH OF THE AREA AND WILL PUSH BACK INTO THE AREA ON
SUNDAY NIGHT. THE DIFFERENCE IN SHORT WAVE TIMING INCREASES WITH
TIME...HOWEVER THE GENERAL PATTERN TRANSITION IS IN PRETTY GOOD
AGREEMENT. THE SEQUENCING HAS HIGH CONFIDENCE...HOWEVER THE TIMING
OF THE SHORT WAVES DECREASES CONFIDENCE IN WITH TIME. FOR
TEMPS...NUDGED THE FORECAST TOWARD THE MODEL BLEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 150 AM EDT TUE JUL 24 2012
FOG LIMITED TO THE DEEPER VALLEYS IS POSSIBLE DURING THE LATE NIGHT
AND EARLY MORNING. OTHERWISE...VFR IS ANTICIPATED INTO THE AFTERNOON.
WILL EXPECT THUNDERSTORMS...ESPECIALLY FOR THE NE PART OF THE
FORECAST AREA...BETWEEN ABOUT 17Z AND 23Z...WITH A POTENTIAL FOR
BRIEF IFR. QUIET WX IS THEN EXPECTED TO FINISH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...KAS
LONG TERM....JJ
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
441 PM EDT TUE JUL 24 2012
.SYNOPSIS...
A COLD FRONT WILL DROP SOUTH ACROSS THE REGION TONIGHT...STALLING
ACROSS THE CAROLINAS ON WEDNESDAY. HIGH PRESSURE WILL BRIEFLY
BUILD IN FROM THE NORTH THROUGH WEDNESDAY NIGHT...BEFORE THE FRONT
SURGES BACK NORTH AS A WARM FRONT EARLY THURSDAY. ANOTHER COLD
FRONT CROSSES THE MID ATLANTIC OVER THE UPCOMING WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
SVR TSTM WATCHES 510 AND 513 ARE IN EFFECT FOR THE ENTIRE FA. SCT
SHWRS/TSTMS EXPECTED THIS AFTN/EVNG IN ASSOCIATION WITH UPSTREAM
MID-LVL ENERGY AND A PRE-FRONTAL TROF. COVERAGE IS STILL A
QUESTION AS WESTERLY LO-LVL FLOW IS NOT PARTICULARLY
FAVORABLE...BUT WILL CONTINUE 50-60% POPS ATTM. CONDITIONS
CONTINUE TO BE CONDUCIVE TO STRONG TO SVR STORMS THROUGHOUT THE FA
AS MLCAPE IS 3000-4000 J/KG...0-6 KM BULK SHEAR IS 30-35 KT...AND
LIFTED INDICES ARE AROUND -10 PER LATEST RAP ANALYSIS. MID
ATLANTIC REGION REMAINS IN SLIGHT RISK AREA FOR TODAY...WITH AKQ
CWA REMAINING HIGHLIGHTED IN HIGHEST WIND PROBABILITY AREA. WILL
CONTINUE TO REFLECT SEVERE WX THREAT IN HWO.
PRECIP WILL ADVANCE SE THROUGH THE REGION THIS EVNG...CLEARING BY
AROUND MIDNGT. COLD FROPA OCCURS TNGT WITH MSTLY CLR SKIES AND
TEMPS DROPPING INTO THE UPR 60S/LWR 70S.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
DRY CONDITIONS EXPECTED FOR THE REMAINDER OF THE WORK WEEK WITH A
DRIER AIR MASS IN PLACE. SFC HI PRES BLDS IN FROM THE NORTH WED
WITH DEWPTS DROPPING INTO THE LOW 60S AND HIGH TEMPS ONLY IN THE
UPR 80S TO NEAR 90. WARM FRONT PUSHES NORTH THROUGH THE AREA WED
NGT...WITH S/SW FLOW AND HOT CONDITIONS RETURNING THU. TEMPS WILL
CLIMB INTO THE MID TO UPR 90S...APPROACHING 100 OVER AREAS
ALONG/WEST OF I-95. HIGHS AGAIN IN THE MID TO UPR 90S FRI AHEAD OF
THE NEXT FRONTAL SYSTEM.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
BROAD UPR LVL TROUGH TO RMN ANCHOR OVR THE NE CONUS W/ RIDGE OVR THE
NATIONS MIDSECTION FOR THE EXTENDED PD...RESULTING IN NWLY FLO INTO
THE MDATLC RGN. TIMING SYSTEMS IN SUCH A PATTERN RMNG DIFFICULT. A
FNTL BNDRY IS SLO TO REACH THE CSTL CAROLINAS FRI NGT INTO SAT...AND
IS NOW FCST TO CONT MOVG SSE THROUGH SUN. WK SFC HI PRES TO SLIDE BY
N OF THE RGN LT WKND INTO MON/TUE.
OVRALL...CLR-PCLDY THROUGH THE PD. WILL CONT W/ CHC POPS E AND SE
FRI NGT INTO SAT...THEN HAVE SLGT CHC/CHC POPS (MNLY INLAND) MON AND
TUE AS WINDS BCM E THEN S EARLY NEXT WEEK. HI TEMPS IN THE L/M90S
FRI...U80S TO L90S SAT...THEN IN THE 80S TO ARND 90F SUN/MON/TUE.
LO TEMPS IN THE L/M70S.
&&
.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...SCT TSTMS ARE EXPECTED ACROSS THE FORECAST AREA THIS
AFTN AND EARLY EVENING. SEVERE TSTM WATCH 510 COVERS RIC AND SBY TIL
22Z AND ANOTHER WATCH MAY BE ISSUED LATER THIS AFTN FOR THE REST OF
THE TAF SITES.
WILL HOLD OFF ON INCLUDING TSTMS IN THE TAFS UNTIL CONFIDENCE IN
TIMING IS HIGH. CURRENTLY THERE ARE TSTMS IN THE MOUNTAINS UPSTREAM
FROM RIC AND WITH THE WATCH ENDING AT 22Z...INCLUDED TEMPO GROUP
FROM 20-22Z THERE. SOME TAF SITES COULD MISS THE TSTMS AS COVERAGE
IS EXPECTED TO BE SCATTERED.
THE COLD FRONT MOVES THROUGH BETWEEN 00 AND 06Z AND BRINGS A WIND
SHIFT TO NW/N EXCEPT BECOMING N/NE AT ORF. VFR CONDITIONS WILL
CONTINUE THROUGH THE MORNING HOURS WITH WIND AND LOWERING DEW POINTS
INHIBITING FOG FORMATION. MOSTLY CLEAR SKIES ARE EXPECTED DURING THE
DAY WEDNESDAY.
OUTLOOK...DRY/VFR CONDITIONS WILL CONTINUE THURSDAY. OTHER THAN A
SLGT CHC FOR TSTMS FRIDAY AFTN...DRY WEATHER SHOULD PREVAIL THROUGH
THE WEEKEND. THE CHANCES FOR EARLY MORNING FOG APPEAR MINIMAL AT
THIS TIME.
&&
.MARINE...
WILL CONT W/ A (MARGINAL) SCA...MNLY FM AFT MDNGT INTO WED
MRNG...FOR THE CHES BAY AND ATLC WTRS. CDFNT TO SETTLE S ACRS THE
WTRS THROUGH THE EVE INTO THE OVRNGT HRS. PD OF NNW WNDS POST FNTL
XPCD...THOUGH RMNS UNCERTAIN AS TO JUST HOW MUCH OF A SURGE IN SPD
THERE WILL BE. A COOLER/DRIER AMS TO ARRIVE FM THE N OVR THE WARMER
WTRS...AND IF A MONTH OR TWO LATER...WOULD LIKELY BE A HIGHER PROB.
FOR NOW...CAPPING WINDS MNLY FM 15 TO 20 KT. CORRESPONDING
WAVES/SEAS TO RISE TO LWR END OF SCA (WHICH IS 4 FT ON THE BAY/5 FT
ON THE OCN). AFT A PD OF LGT/VRB WNDS FM LT WED INTO WED
NGT...MODELS HAVE WNDS BMCG SSW AGN BY THU WHL INCRSG IN SPD BACK TO
ABT 10 TO 15 KT. ANOTHER FNT TO CROSS THE WTRS LT FRI INTO SAT MRNG.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NCZ012>017-
030>032.
VA...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR VAZ087>097.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 AM EDT WEDNESDAY FOR ANZ650-652-
654-656-658.
SMALL CRAFT ADVISORY UNTIL 11 AM EDT WEDNESDAY FOR ANZ630>632-
634.
&&
$$
SYNOPSIS...MAS/MAM
NEAR TERM...MAS
SHORT TERM...MAS
LONG TERM...ALB
AVIATION...LSA
MARINE...ALB
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
345 PM EDT TUE JUL 24 2012
.SYNOPSIS...
A COLD FRONT WILL DROP SOUTH ACROSS THE REGION TONIGHT...STALLING
ACROSS THE CAROLINAS ON WEDNESDAY. HIGH PRESSURE WILL BRIEFLY
BUILD IN FROM THE NORTH THROUGH WEDNESDAY NIGHT...BEFORE THE FRONT
SURGES BACK NORTH AS A WARM FRONT EARLY THURSDAY. ANOTHER COLD
FRONT CROSSES THE MID ATLANTIC OVER THE UPCOMING WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
SVR TSTM WATCH 510 IS IN EFFECT FOR NW HALF OF THE FA UNTIL 8 PM.
SCT SHWRS/TSTMS EXPECTED THIS AFTN/EVNG IN ASSOCIATION WITH
UPSTREAM MID-LVL ENERGY AND A PRE-FRONTAL TROF. COVERAGE IS STILL
A QUESTION AS WESTERLY LO-LVL FLOW IS NOT PARTICULARLY
FAVORABLE...BUT WILL CONTINUE 50-60% POPS ATTM. CONDITIONS
CONTINUE TO BE CONDUCIVE TO STRONG TO SVR STORMS THROUGHOUT THE FA
AS MLCAPE IS 3000-4000 J/KG...0-6 KM BULK SHEAR IS 30-35 KT...AND
LIFTED INDICES ARE AROUND -10 PER LATEST RAP ANALYSIS. MID
ATLANTIC REGION REMAINS IN SLIGHT RISK AREA FOR TODAY...WITH AKQ
CWA REMAINING HIGHLIGHTED IN HIGHEST WIND PROBABILITY AREA. WILL
CONTINUE TO REFLECT SEVERE WX THREAT IN HWO.
PRECIP WILL ADVANCE SE THROUGH THE REGION THIS EVNG...CLEARING BY
AROUND MIDNGT. COLD FROPA OCCURS TNGT WITH MSTLY CLR SKIES AND
TEMPS DROPPING INTO THE UPR 60S/LWR 70S.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
DRY CONDITIONS EXPECTED FOR THE REMAINDER OF THE WORK WEEK WITH A
DRIER AIR MASS IN PLACE. SFC HI PRES BLDS IN FROM THE NORTH WED
WITH DEWPTS DROPPING INTO THE LOW 60S AND HIGH TEMPS ONLY IN THE
UPR 80S TO NEAR 90. WARM FRONT PUSHES NORTH THROUGH THE AREA WED
NGT...WITH S/SW FLOW AND HOT CONDITIONS RETURNING THU. TEMPS WILL
CLIMB INTO THE MID TO UPR 90S...APPROACHING 100 OVER AREAS
ALONG/WEST OF I-95. HIGHS AGAIN IN THE MID TO UPR 90S FRI AHEAD OF
THE NEXT FRONTAL SYSTEM.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
BROAD UPR LVL TROUGH TO RMN ANCHOR OVR THE NE CONUS W/ RIDGE OVR THE
NATIONS MIDSECTION FOR THE EXTENDED PD...RESULTING IN NWLY FLO INTO
THE MDATLC RGN. TIMING SYSTEMS IN SUCH A PATTERN RMNG DIFFICULT. A
FNTL BNDRY IS SLO TO REACH THE CSTL CAROLINAS FRI NGT INTO SAT...AND
IS NOW FCST TO CONT MOVG SSE THROUGH SUN. WK SFC HI PRES TO SLIDE BY
N OF THE RGN LT WKND INTO MON/TUE.
OVRALL...CLR-PCLDY THROUGH THE PD. WILL CONT W/ CHC POPS E AND SE
FRI NGT INTO SAT...THEN HAVE SLGT CHC/CHC POPS (MNLY INLAND) MON AND
TUE AS WINDS BCM E THEN S EARLY NEXT WEEK. HI TEMPS IN THE L/M90S
FRI...U80S TO L90S SAT...THEN IN THE 80S TO ARND 90F SUN/MON/TUE.
LO TEMPS IN THE L/M70S.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...SCT TSTMS ARE EXPECTED ACROSS THE FORECAST AREA THIS
AFTN AND EARLY EVENING. SEVERE TSTM WATCH 510 COVERS RIC AND SBY TIL
22Z AND ANOTHER WATCH MAY BE ISSUED LATER THIS AFTN FOR THE REST OF
THE TAF SITES.
WILL HOLD OFF ON INCLUDING TSTMS IN THE TAFS UNTIL CONFIDENCE IN
TIMING IS HIGH. CURRENTLY THERE ARE TSTMS IN THE MOUNTAINS UPSTREAM
FROM RIC AND WITH THE WATCH ENDING AT 22Z...INCLUDED TEMPO GROUP
FROM 20-22Z THERE. SOME TAF SITES COULD MISS THE TSTMS AS COVERAGE
IS EXPECTED TO BE SCATTERED.
THE COLD FRONT MOVES THROUGH BETWEEN 00 AND 06Z AND BRINGS A WIND
SHIFT TO NW/N EXCEPT BECOMING N/NE AT ORF. VFR CONDITIONS WILL
CONTINUE THROUGH THE MORNING HOURS WITH WIND AND LOWERING DEW POINTS
INHIBITING FOG FORMATION. MOSTLY CLEAR SKIES ARE EXPECTED DURING THE
DAY WEDNESDAY.
OUTLOOK...DRY/VFR CONDITIONS WILL CONTINUE THURSDAY. OTHER THAN A
SLGT CHC FOR TSTMS FRIDAY AFTN...DRY WEATHER SHOULD PREVAIL THROUGH
THE WEEKEND. THE CHANCES FOR EARLY MORNING FOG APPEAR MINIMAL AT
THIS TIME.
&&
.MARINE...
WILL CONT W/ A (MARGINAL) SCA...MNLY FM AFT MDNGT INTO WED
MRNG...FOR THE CHES BAY AND ATLC WTRS. CDFNT TO SETTLE S ACRS THE
WTRS THROUGH THE EVE INTO THE OVRNGT HRS. PD OF NNW WNDS POST FNTL
XPCD...THOUGH RMNS UNCERTAIN AS TO JUST HOW MUCH OF A SURGE IN SPD
THERE WILL BE. A COOLER/DRIER AMS TO ARRIVE FM THE N OVR THE WARMER
WTRS...AND IF A MONTH OR TWO LATER...WOULD LIKELY BE A HIGHER PROB.
FOR NOW...CAPPING WINDS MNLY FM 15 TO 20 KT. CORRESPONDING
WAVES/SEAS TO RISE TO LWR END OF SCA (WHICH IS 4 FT ON THE BAY/5 FT
ON THE OCN). AFT A PD OF LGT/VRB WNDS FM LT WED INTO WED
NGT...MODELS HAVE WNDS BMCG SSW AGN BY THU WHL INCRSG IN SPD BACK TO
ABT 10 TO 15 KT. ANOTHER FNT TO CROSS THE WTRS LT FRI INTO SAT MRNG.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NCZ012>017-
030>032.
VA...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR VAZ087>097.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 AM EDT WEDNESDAY FOR ANZ650-652-
654-656-658.
SMALL CRAFT ADVISORY UNTIL 11 AM EDT WEDNESDAY FOR ANZ630>632-
634.
&&
$$
SYNOPSIS...MAS/MAM
NEAR TERM...MAS
SHORT TERM...MAS
LONG TERM...ALB
AVIATION...LSA
MARINE...ALB
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
342 PM EDT TUE JUL 24 2012
.SYNOPSIS...
A COLD FRONT, MOVING SOUTHWARD THROUGH THE UPPER OHIO VALLEY, CAN
STILL CAUSE SCATTERED THUNDERSTORMS MAINLY SOUTH OF PITTSBURGH
EARLY THIS EVENING. ANOTHER FRONT WILL BRING SCATTERED
THUNDERSTORMS WEDNESDAY NIGHT, THURSDAY, AND FRIDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
TREND OF RECENT RADAR DATA AND HRRR MODEL OUTPUT SHOWS SCATTERED
THUNDERSTORMS WILL BE ENDING THIS EVENING, AS THE PASSING DEW
POINT FRONT CONTINUES MOVING SOUTHEASTWARD THROUGH THE UPPER OHIO
VALLEY.
HAVE MADE ADDED ADJUSTMENTS TO LATE AFTERNOON AND EVENING
TEMPERATURES BASED ON EVAPORATIVE-COOLING EFFECTS OF RECENT
THUNDERSTORM RAINS.
LIKEWISE, HAVE ADDED LATE NIGHT PATCHY FOG TO AREAS SOUTH OF THE
NEW PHILADELPHIA OHIO, AND PITTSBURGH AND INDIANA PENNSYLVANIA
CORRIDOR, DUE TO EXPECTED LOW LEVEL CONDENSATION AS RAIN-MOISTENED
SURFACE LAYER NOCTURNALLY COOLS TO SATURATION.
FORECASTED LOW TEMPERATURES AND DEW POINTS TONIGHT USING BLEND OF
GFS MOS AND NAM MODEL OUTPUT.
RECENT SREF MODEL OUTPUT SHOWS THE DEW POINT FRONT WILL BE ACROSS
WEST VIRGINIA WEDNESDAY, SO EXPECT RAINFREE CONDITIONS. THIS WILL
PROMOTE A GOOD BIT OF SUNSHINE, AND SO WARMER THAN NORMAL
TEMPERATURES, PER BLEND OF NAM AND GFS MOS.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
WITH SREF MODEL OUTPUT SHOWING LOW LEVEL WINDS BECOMING SOUTH AND
SOUTHWEST ACROSS THE UPPER OHIO VALLEY WEDNESDAY NIGHT, THE
SURFACE LAYER WILL BECOME HUMID.
ADDITIONALLY, MOST SREF MODEL MEMBERS SHOW FRONTOGENESIS ACROSS
THE GREAT LAKES WEDNESDAY NIGHT, DUE TO AN UPPER LEVEL JET MAX,
THAT WILL CONTRIBUTE TO THE DEVELOPMENT OF A LOW PRESSURE CENTER
NEAR WISCONSIN. THE RESULTING COLD FRONT WILL THEN BEGIN TO MOVE
VERY SLOWLY SOUTHEASTWARD ACROSS THE UPPER OHIO VALLEY THURSDAY
INTO FRIDAY.
ONSET OF INCREASED PREFRONTAL CONVERGENCE WITHIN A HUMID AND
UNSTABLE AIR MASS, WILL PRODUCE A CHANCE OF THUNDERSTORMS LATE
WEDNESDAY NIGHT INTO FRIDAY. CONCUR WITH SPC REGARDING A SLIGHT
RISK OF SEVERE THUNDERSTORMS, DUE TO STRONGER WINDS ALOFT
RESULTING IN INCREASED VERTICAL WIND SHEAR.
REGARDING TEMPERATURES, BLEND OF NAM AND GFS MOS SHOW SOME SPOTS
WITH HIGHS OF 90 THURSDAY. HIGHS FRIDAY WILL BE A TAD LESS. LOWS
WEDNESDAY NIGHT AND THURSDAY NIGHT WILL BE MAINLY IN THE UPPER 60S
TO LOWER 70S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
LATEST MEDIUM RANGE MODELS MOVE A SHORT WAVE TROUGH OVER THE GREAT
LAKES EAST TO THE NEW ENGLAND COAST BY SUNDAY NIGHT. SCATTERED
SHOWERS AND THUNDERSTORMS WILL CONTINUE UNTIL A COLD FRONT PUSHES
SOUTH OF THE REGION SATURDAY NIGHT.
SURFACE HIGH PRESSURE SHOULD BUILD INTO THE REGION AND PROVIDE DRY
WEATHER SUNDAY AND MONDAY. ISOLATED SHOWERS AND STORMS ARE
FORECAST TO RETURN BY TUESDAY, AS THE NEXT SYSTEM APPROACHES FROM
THE MIDWEST.
FORECAST TEMPERATURES ARE CLOSE TO HPC GUIDANCE AND WILL BE NEAR
NORMAL THROUGH SUNDAY...WARMING TO AROUND 5 DEGREES ABOVE NORMAL
FOR MONDAY AND TUESDAY.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
PER RECENT SURFACE AND RADAR DATA, COUPLED WITH HRRR MODEL OUTPUT,
MAINTAINED MENTION OF TEMPO IFR/MVFR RESTRICTIONS FOR SHOWERS AND
THUNDERSTORMS KPIT AND SOUTH THROUGH 21Z. SURFACE WINDS WILL BE
NORTHWEST 10 KT GUSTING TO 20 KT...WITH HIGHER GUSTS POSSIBLE NEAR
THUNDERSTORMS.
POSTFRONTAL DRYING WILL PROMOTE VFR BEGINNING THIS EVENING.
POTENTIAL EXISTS FOR LATE NIGHT PATCHY FOG, BUT NOT ENOUGH
CONFIDENCE TO MENTION IN TAFS, EXCEPT FOR TEMPO 3SM AT KLBE AFT 08Z.
NORTHWEST SURFACE WINDS SHOULD DIMINISH TO LIGHT AND VARIABLE LATE
TONIGHT...THEN BECOME SOUTHERLY 5 TO 10 KT WEDNESDAY.
OUTLOOK...WEDNESDAY NIGHT THROUGH SUNDAY...
GENERALLY VFR WILL PREVAIL. POTENTIAL EXISTS FOR OCCASIONAL
RESTRICTIONS IN THUNDERSTORMS LATE THURSDAY THROUGH SATURDAY EVENING
AS A SERIES OF WAVES TRACK ALONG A FRONTAL BOUNDARY STRETCHED ACROSS
THE OHIO VALLEY. A SURFACE RIDGE SHOULD PROVIDE DRY WEATHER SUNDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
218 PM EDT TUE JUL 24 2012
.SYNOPSIS...
A COLD FRONT, MOVING SOUTHWARD THROUGH THE UPPER OHIO VALLEY, CAN
STILL CAUSE SCATTERED THUNDERSTORMS MAINLY SOUTH OF PITTSBURGH, WITH GUSTY
WIND, HAIL, AND HEAVY RAIN, INTO EARLY EVENING. ANOTHER FRONT
WILL BRING SCATTERED THUNDERSTORMS WEDNESDAY NIGHT, THURSDAY AND
FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
RECENT RADAR AND SURFACE DATA SHOW ADDITIONAL PREFRONTAL
SCATTERED THUNDERSTORMS WILL BE MOVING SOUTHEASTWARD ACROSS THE
UPPER OHIO VALLEY, MAINLY SOUTH OF NEW PHILADELPHIA OHIO, AND
PITTSBURGH AND INDIANA PENNSYLVANIA. SOME STORMS CAN HAVE GUSTY
WIND, HAIL, HEAVY RAIN, AND FREQUENT LIGHTNING. SPC GUIDANCE
CONTINUES TO SHOW STORMS CAN REACH SEVERE LIMITS.
HAVE MADE ADDED ADJUSTMENTS TO AFTERNOON AND EVENING TEMPERATURES
BASED ON EVAPORATIVE-COOLING EFFECTS OF RECENT THUNDERSTORM RAINS.
LIKEWISE, HAVE ADDED LATE NIGHT PATCHY FOG TO AREAS SOUTH OF THE
NEW PHILADELPHIA OHIO, AND PITTSBURGH AND INDIANA PENNSYLVANIA
CORRIDOR, DUE TO EXPECTED LOW LEVEL CONDENSATION AS RAIN-MOISTENED
SURFACE LAYER NOCTURNALLY COOLS TO SATURATION.
FORECASTED LOW TEMPERATURES AND DEW POINTS TONIGHT USING BLEND OF
GFS MOS AND NAM MODEL OUTPUT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
RECENT SREF MODEL OUTPUT SHOWS THE DEW POINT FRONT WILL BE ACROSS
WEST VIRGINIA WEDNESDAY, SO EXPECT RAINFREE CONDITIONS. THIS WILL
PROMOTE A GOOD BIT OF SUNSHINE, AND SO WARMER THAN NORMAL
TEMPERATURES, PER BLEND OF NAM AND GFS MOS.
WITH LOW LEVEL WINDS BECOMING SOUTH AND SOUTHWEST WEDNESDAY NIGHT,
THE SURFACE LAYER WILL BECOME HUMID ACROSS THE UPPER OHIO VALLEY.
MOST SREF MODEL MEMBERS SHOW FRONTOGENESIS ACROSS THE GREAT LAKES
WEDNESDAY NIGHT, DUE TO AN UPPER LEVEL JET MAX, THAT WILL
CONTRIBUTE TO THE DEVELOPMENT OF A LOW PRESSURE CENTER NEAR
WISCONSIN. THE RESULTING COLD FRONT WILL THEN MOVE SLOWLY
SOUTHEASTWARD ACROSS THE UPPER OHIO VALLEY THURSDAY INTO FRIDAY.
ONSET OF THIS INCREASED CONVERGENCE WITHIN A HUMID AND UNSTABLE
AIR MASS, WILL PRODUCE A CHANCE OF THUNDERSTORMS LATE WEDNESDAY
NIGHT INTO FRIDAY. CONCUR WITH SPC REGARDING A SLIGHT RISK OF
SEVERE THUNDERSTORMS, DUE TO INCREASED VERTICAL WIND SHEAR.
REGARDING TEMPERATURES, BLEND OF NAM AND GFS MOS SHOW SOME SPOTS
WITH HIGHS OF 90 THURSDAY. HIGHS FRIDAY WILL BE A TAD LESS. LOWS
WEDNESDAY NIGHT AND THURSDAY NIGHT WILL BE MAINLY IN THE UPPER 60S
TO LOWER 70S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
LATEST MEDIUM RANGE MODELS STILL DIG A SHORT WAVE TROUGH ACROSS THE
GREAT LAKES REGION FRIDAY AND SLOWLY MOVE THE TROUGH AXIS MOVE EAST
TO THE NEW ENGLAND COAST BY MONDAY.
KEPT SCATTERED SHOWERS AND THUNDERSTORMS IN THE FORECAST FRIDAY
NIGHT AND SATURDAY...WITH DRY WEATHER EXPECTED SUNDAY INTO MONDAY
AS THE UPPER TROUGH MOVES EAST AND A WEAK SURFACE HIGH BRINGS
DRIER AIR IN FROM THE NORTHWEST.
FORECAST TEMPERATURES ARE CLOSE TO HPC GUIDANCE AND NEAR NORMAL
THROUGH THE EXTENDED PERIOD.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
PER RECENT SURFACE AND RADAR DATA, COUPLED WITH HRRR MODEL OUTPUT,
MAINTAINED MENTION OF TEMPO MVFR RESTRICTIONS WITH SHOWERS AND
SCATTERED THUNDERSTORMS KZZV-KPIT AND SOUTH. SURFACE WINDS WILL
BECOME NORTHWEST NEAR 10 KTS WITH GUSTS TO 20 KTS. HIGHER GUSTS
POSSIBLE NEAR THUNDERSTORMS.
POSTFRONTAL DRYING WILL PROMOTE VFR STARTING THIS EVENING.
POTENTIAL FOR LATE NIGHT PATCHY FOG MAY PRODUCE RESTRICTIONS, BUT
NOT ENOUGH CONFIDENCE TO MENTION IN TAF.
OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
GEN VFR...BUT WITH PERIODIC CHCS FOR TSRA/ASSOCIATED RESTRICTIONS
ARE EXPECTED FOR THE REMAINDER OF THE WEEK AS A SERIES OF SHRTWVS
TRACK ACRS THE UPR OH VALLEY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
206 PM EDT TUE JUL 24 2012
.SYNOPSIS...
A COLD FRONT WILL DROP SOUTH ACROSS THE REGION TONIGHT...STALLING
ACROSS THE CAROLINAS ON WEDNESDAY. HIGH PRESSURE WILL BRIEFLY
BUILD IN FROM THE NORTH THROUGH WEDNESDAY NIGHT...BEFORE THE FRONT
SURGES BACK NORTH AS A WARM FRONT EARLY THURSDAY. ANOTHER COLD
FRONT CROSSES THE MID ATLANTIC OVER THE UPCOMING WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
SCT SHWRS/TSTMS EXPECTED THIS AFTN/EVNG IN ASSOCIATION WITH
UPSTREAM MID-LVL ENERGY AND A PRE-FRONTAL TROF. COVERAGE IS STILL
A QUESTION AS WESTERLY LO-LVL FLOW IS NOT PARTICULARLY
FAVORABLE...BUT WILL CONTINUE 50% POPS ATTM. CONDITIONS CONTINUE TO
BE CONDUCIVE TO STRONG TO SVR STORMS THROUGHOUT THE FA AS MLCAPE
IS 3000-4000 J/KG...0-6 KM BULK SHEAR IS 30-35 KT...AND LIFTED
INDICES ARE AROUND -10 PER LATEST RAP ANALYSIS. MID ATLANTIC
REGION REMAINS IN SLIGHT RISK AREA FOR TODAY...WITH AKQ CWA
REMAINING HIGHLIGHTED IN HIGHEST WIND PROBABILITY AREA. WILL
CONTINUE TO REFLECT SEVERE WX THREAT IN HWO.
OTHER BIG STORY TODAY WILL BE HOTTER TEMPS...EXACERBATED BY
COMPRESSIONAL HEATING AHEAD OF APPROACHING COLD FRONT TO THE
NORTH. FORECAST MAXIMA REMAIN IN THE MID 90S FOR MOST OF THE CWA,
AND WITH JUST ENOUGH AFTN MIXING TO DROP DEWPOINTS BACK INTO THE
UPPER 60S INLAND, CONCERN FOR HEAT ADVISORY REMAINS MAINLY OVER
THE SE VA/NE NC COASTAL PLAIN. GIVEN DEWPOINTS EXPECTED TO REMAIN
IN THE LOWER 70S, A PERIOD OF HEAT ADVY CRITERIA WILL LKLY BE
ACHIEVED OVER HAMPTON ROADS/TIDEWATER AREA, INCLUDING NC COUNTIES.
ACCORDINGLY, HV GONE AHEAD WITH HEAT ADVISORY FOR THESE AREAS.
ELSEWHERE, EXPECT APPARENT TEMP VALUES TO VARY A BIT LESS FROM AIR
TEMP, WITH HEAT INDICES HANGING RIGHT ~100 F FOR EARLY AFTN.
SCT CONVECTION WILL SLIDE TOWARDS SOUTHERN PORTIONS OF CWA BY EARLY
THIS EVENING, WITH THE FRONT TO DROP SOUTH ACROSS THE AREA IN BACK
DOOR FRONT ORIENTATION OVERNIGHT. GRADUALLY DIMINISHED POPS AFTER
SUNSET, WITH GRADUAL CLEARING AND RAIN CHCS ENDING AFTER MIDNIGHT
FOR ALL BUT FAR SE CWA AS COOLER/DRIER AIR SLOWLY OOZE SOUTH
OVERNIGHT INTO WEDNESDAY MORNING. LOOK FOR EARLY MORNING LOWS WED
INTO THE U60S ACROSS THE NORTH/MID 70S SOUTH.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
WEAK CAA CONTINUES WED AS DEWPOINTS DROP BACK INTO THE L0W 60S (AT
LEAST) IN MOST SPOTS. PLEASANT DAY WXWISE WITH HIGHS ONLY IN THE
UPR 80S TO ~90 UNDER A SUNNY TO MOSTLY SUNNY SKY. THE FRONT THAT
DROPS SOUTH ACROSS THE AREA LATE TONIGHT AND WED, WILL LIFT BACK
NORTH OF THE REGION AS A WARM FRONT LATE WEDNESDAY NIGHT INTO THU.
RESULTANT VEERING OF WINDS AROUND TO THE S/SW WILL YIELD RETURN OF
HEAT FOR THU. MAXIMA ARE EXPECTED TO QUICKLY SURGE BACK INTO THE
MID 90S. RAIN CHCS REMAIN RATHER LOW DURING THIS PERIOD. THOUGH
HAVE ALLOWED FOR SLIGHT CHC WEST OF RIC ON WED IN ASSN WITH
ADDITIONAL SPOKES OF S/W ENERGY DROPPING SE ALONG PERIPHERY OF
RETROGRADING UPPER ANTICYCLONE. WENT WITH SLIGHT CHC/LOW CHC ON
THURSDAY WITH ISO- WIDELY SCT TSRA POSSIBLE ALONG DEVELOPING LEE
SIDE TROUGH.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
BROAD UPR LVL TROUGH TO RMN ANCHOR OVR THE NE CONUS W/ RIDGE OVR THE
NATIONS MIDSECTION FOR THE EXTENDED PD...RESULTING IN NWLY FLO INTO
THE MDATLC RGN. TIMING SYSTEMS IN SUCH A PATTERN DIFFICULT FROM THIS
FAR OUT. CDFNT TO CROSS THE RGN THU NGT INTO FRI...THEN LINGER OVR
THE CAROLINAS. SERIES OF WK AREAS OF SFC LO PRES FCST TO TRACK ALG
THE LINGERING BNDRY. OVRALL...MNLY PCLDY W/ PRIMARILY DIURNAL
POPS...ESP FRI AND AGN SAT. TEMPS AVGG A FEW DEGS F ABV NRML (THOUGH
RMNG LARGELY W/ +1 STANDARD DEVIATION OF NRML). HI TEMPS IN THE
L/M90S FRI...U80S TO L90S SAT AND SUN...AND 80S MON. LO TEMPS IN THE
M/U70S THU NGT/FRI NGT...AND L/M70S SAT NGT/SUN NGT.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...SCT TSTMS ARE EXPECTED ACROSS THE FORECAST AREA THIS
AFTN AND EARLY EVENING. SEVERE TSTM WATCH 510 COVERS RIC AND SBY TIL
22Z AND ANOTHER WATCH MAY BE ISSUED LATER THIS AFTN FOR THE REST OF
THE TAF SITES.
WILL HOLD OFF ON INCLUDING TSTMS IN THE TAFS UNTIL CONFIDENCE IN
TIMING IS HIGH. CURRENTLY THERE ARE TSTMS IN THE MOUNTAINS UPSTREAM
FROM RIC AND WITH THE WATCH ENDING AT 22Z...INCLUDED TEMPO GROUP
FROM 20-22Z THERE. SOME TAF SITES COULD MISS THE TSTMS AS COVERAGE
IS EXPECTED TO BE SCATTERED.
THE COLD FRONT MOVES THROUGH BETWEEN 00 AND 06Z AND BRINGS A WIND
SHIFT TO NW/N EXCEPT BECOMING N/NE AT ORF. VFR CONDITIONS WILL
CONTINUE THROUGH THE MORNING HOURS WITH WIND AND LOWERING DEW POINTS
INHIBITING FOG FORMATION. MOSTLY CLEAR SKIES ARE EXPECTED DURING THE
DAY WEDNESDAY.
OUTLOOK...DRY/VFR CONDITIONS WILL CONTINUE THURSDAY. OTHER THAN A
SLGT CHC FOR TSTMS FRIDAY AFTN...DRY WEATHER SHOULD PREVAIL THROUGH
THE WEEKEND. THE CHANCES FOR EARLY MORNING FOG APPEAR MINIMAL AT
THIS TIME.
&&
.MARINE...
SW WINDS TODAY WILL BECOME BREEZY BY THIS AFTERNOON AS A COLD FRONT
APPROACHES THE REGION. EXPECT WINDS TO SHIFT TO THE W THIS EVENING...
BECOMING NW-N BEHIND THE FRONT AS IT TRACKS FROM NORTHWEST TO
SOUTHEAST ACROSS THE WATERS. CAA STILL DOES NOT APPEAR TO BE VERY
STRONG BUT A PROLONGED PERIOD OF NLY WINDS INTO WED HAS PROMPTED
THE ISSUANCE OF SCA FLAGS THROUGH EARLY WED MORNING. WINDS OVER
THE BAY/SOUND SHOULD TOP OUT AROUND 25 KT WITH WAVES OF 2-3 FT AND
UP TO 4 FT AT TIMES. NRN OCEAN WATERS WILL FIRST EXPERIENCE GUSTS
OF 25 KT AND SEAS OF 3-5 FT...WHILE SRN OCEAN WATERS WILL SEE
GUSTS OF 25 KT AFTER MIDNIGHT AND SEAS OF GENERALLY 2-4 FT.
HIGH PRESSURE BUILDS IN FROM THE NORTHWEST ON WED AND THE GRADIENT
RELAXES. WINDS WILL THEN VEER TO THE S-SW LATE WED NIGHT THROUGH FRI
AS A LOW PRESSURE SYSTEM MOVING ACROSS CENTRAL PENNSYLVANIA DRAGS A
WEAK FRONT ACROSS THE WATERS THURSDAY NIGHT INTO FRIDAY MORNING.
SEAS WILL GENERALLY BE 2-3 FT (OCCASIONALLY 4 FT NEAR 20 NM) AND
WAVES 1-2 FT (INCREASING TO 3 FT AT TIMES...ESPECIALLY DURING THE
OVERNIGHT HOURS DUE TO DIURNAL INSTABILITY EFFECTS).
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NCZ012>017-
030>032.
VA...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR VAZ087>097.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 9 AM EDT
WEDNESDAY FOR ANZ638-650-652-654.
SMALL CRAFT ADVISORY FROM 2 AM TO 9 AM EDT WEDNESDAY FOR
ANZ633-656-658.
SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
WEDNESDAY FOR ANZ630>632-634.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAS/MAM
SHORT TERM...MAS/MAM
LONG TERM...ALB
AVIATION...LSA
MARINE...BMD
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1214 PM EDT TUE JUL 24 2012
.SYNOPSIS...
A COLD FRONT WILL DROP SOUTH ACROSS THE REGION TONIGHT...STALLING
ACROSS THE CAROLINAS ON WEDNESDAY. HIGH PRESSURE WILL BRIEFLY
BUILD IN FROM THE NORTH THROUGH WEDNESDAY NIGHT...BEFORE THE FRONT
SURGES BACK NORTH AS A WARM FRONT EARLY THURSDAY. ANOTHER COLD
FRONT CROSSES THE MID ATLANTIC OVER THE UPCOMING WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
SCT SHWRS/TSTMS EXPECTED THIS AFTN/EVNG IN ASSOCIATION WITH
UPSTREAM MID-LVL ENERGY AND A PRE-FRONTAL TROF. COVERAGE IS STILL
A QUESTION AS WESTERLY LO-LVL FLOW IS NOT PARTICULARLY
FAVORABLE...BUT WILL CONTINUE 50% POPS ATTM. CONDITIONS CONTINUE TO
BE CONDUCIVE TO STRONG TO SVR STORMS THROUGHOUT THE FA AS MLCAPE
IS 3000-4000 J/KG...0-6 KM BULK SHEAR IS 30-35 KT...AND LIFTED
INDICES ARE AROUND -10 PER LATEST RAP ANALYSIS. MID ATLANTIC
REGION REMAINS IN SLIGHT RISK AREA FOR TODAY...WITH AKQ CWA
REMAINING HIGHLIGHTED IN HIGHEST WIND PROBABILITY AREA. WILL
CONTINUE TO REFLECT SEVERE WX THREAT IN HWO.
OTHER BIG STORY TODAY WILL BE HOTTER TEMPS...EXACERBATED BY
COMPRESSIONAL HEATING AHEAD OF APPROACHING COLD FRONT TO THE
NORTH. FORECAST MAXIMA REMAIN IN THE MID 90S FOR MOST OF THE CWA,
AND WITH JUST ENOUGH AFTN MIXING TO DROP DEWPOINTS BACK INTO THE
UPPER 60S INLAND, CONCERN FOR HEAT ADVISORY REMAINS MAINLY OVER
THE SE VA/NE NC COASTAL PLAIN. GIVEN DEWPOINTS EXPECTED TO REMAIN
IN THE LOWER 70S, A PERIOD OF HEAT ADVY CRITERIA WILL LKLY BE
ACHIEVED OVER HAMPTON ROADS/TIDEWATER AREA, INCLUDING NC COUNTIES.
ACCORDINGLY, HV GONE AHEAD WITH HEAT ADVISORY FOR THESE AREAS.
ELSEWHERE, EXPECT APPARENT TEMP VALUES TO VARY A BIT LESS FROM AIR
TEMP, WITH HEAT INDICES HANGING RIGHT ~100 F FOR EARLY AFTN.
SCT CONVECTION WILL SLIDE TOWARDS SOUTHERN PORTIONS OF CWA BY EARLY
THIS EVENING, WITH THE FRONT TO DROP SOUTH ACROSS THE AREA IN BACK
DOOR FRONT ORIENTATION OVERNIGHT. GRADUALLY DIMINISHED POPS AFTER
SUNSET, WITH GRADUAL CLEARING AND RAIN CHCS ENDING AFTER MIDNIGHT
FOR ALL BUT FAR SE CWA AS COOLER/DRIER AIR SLOWLY OOZE SOUTH
OVERNIGHT INTO WEDNESDAY MORNING. LOOK FOR EARLY MORNING LOWS WED
INTO THE U60S ACROSS THE NORTH/MID 70S SOUTH.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
WEAK CAA CONTINUES WED AS DEWPOINTS DROP BACK INTO THE L0W 60S (AT
LEAST) IN MOST SPOTS. PLEASANT DAY WXWISE WITH HIGHS ONLY IN THE
UPR 80S TO ~90 UNDER A SUNNY TO MOSTLY SUNNY SKY. THE FRONT THAT
DROPS SOUTH ACROSS THE AREA LATE TONIGHT AND WED, WILL LIFT BACK
NORTH OF THE REGION AS A WARM FRONT LATE WEDNESDAY NIGHT INTO THU.
RESULTANT VEERING OF WINDS AROUND TO THE S/SW WILL YIELD RETURN OF
HEAT FOR THU. MAXIMA ARE EXPECTED TO QUICKLY SURGE BACK INTO THE
MID 90S. RAIN CHCS REMAIN RATHER LOW DURING THIS PERIOD. THOUGH
HAVE ALLOWED FOR SLIGHT CHC WEST OF RIC ON WED IN ASSN WITH
ADDITIONAL SPOKES OF S/W ENERGY DROPPING SE ALONG PERIPHERY OF
RETROGRADING UPPER ANTICYCLONE. WENT WITH SLIGHT CHC/LOW CHC ON
THURSDAY WITH ISO- WIDELY SCT TSRA POSSIBLE ALONG DEVELOPING LEE
SIDE TROUGH.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
BROAD UPR LVL TROUGH TO RMN ANCHOR OVR THE NE CONUS W/ RIDGE OVR THE
NATIONS MIDSECTION FOR THE EXTENDED PD...RESULTING IN NWLY FLO INTO
THE MDATLC RGN. TIMING SYSTEMS IN SUCH A PATTERN DIFFICULT FROM THIS
FAR OUT. CDFNT TO CROSS THE RGN THU NGT INTO FRI...THEN LINGER OVR
THE CAROLINAS. SERIES OF WK AREAS OF SFC LO PRES FCST TO TRACK ALG
THE LINGERING BNDRY. OVRALL...MNLY PCLDY W/ PRIMARILY DIURNAL
POPS...ESP FRI AND AGN SAT. TEMPS AVGG A FEW DEGS F ABV NRML (THOUGH
RMNG LARGELY W/ +1 STANDARD DEVIATION OF NRML). HI TEMPS IN THE
L/M90S FRI...U80S TO L90S SAT AND SUN...AND 80S MON. LO TEMPS IN THE
M/U70S THU NGT/FRI NGT...AND L/M70S SAT NGT/SUN NGT.
&&
.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
UPDATE...POTENTIAL FOR FOG IS LOW FOR TONIGHT AS WINDS HOVER AROUND
10 KT OVERNIGHT. HOWEVER...KSBY COULD SEE SOME REDUCTIONS TO
VISIBILITIES BUT ANY LIMITATIONS SHOULD STAY WITHIN MVFR THRESHOLDS.
OTHERWISE...TAF TRENDS APPEAR TO BE ON TRACK FOR TODAY AND TONIGHT.
PREVIOUS DISCUSSION...SOUTHWEST WINDS OF 5-10 KT OVERNIGHT WILL
PREVENT FOG DEVELOPMENT TOWARD DAYBREAK THIS MORNING. OVERALL...HIGH
CLOUDS WILL STREAM OVER THE REGION THIS MORNING...GRADUALLY LOWERING
AND THICKENING THROUGH THE DAY AS A COLD FRONT APPROACHES FROM THE
NORTHWEST AND TRACKS TO THE SOUTHEAST THIS EVENING INTO TONIGHT.
EXPECT THUNDERSTORMS TO DEVELOP THIS AFTERNOON...PRIMARILY AFTER
23/1800Z. THE SURFACE PRESSURE GRADIENT WILL TIGHTEN AHEAD OF THE
FRONT...RESULTING IN BREEZY SOUTHWEST WINDS WITH GUSTS OF 20-25 KT
THROUGHOUT THE AFTERNOON AND EARLY EVENING HOURS. ONCE
SHOWERS/STORMS END LATE THIS EVENING...SKIES WILL BEGIN TO CLEAR AS
HIGH PRESSURE BUILDS IN FROM THE NORTHWEST. THE COMBINATION OF AMPLE
LOW LEVEL MOISTURE AND DRIER...MORE STABLE AIR ALOFT WILL CREATE
FAVORABLE CONDITIONS FOR FOG AS SURFACE INVERSIONS DEVELOP OVERNIGHT
INTO WEDNESDAY MORNING. HOWEVER...DRY DOWNSLOPE WESTERLY FLOW AND
WINDS MAINTAINING SPEEDS OF 5-10 KT MAY RESULT IN A STRATUS DECK
RATHER THAN GROUND FOG. WILL RE-EVALUATE THIS POTENTIAL WITH THE 12Z
TAF ISSUANCE.
HIGH PRESSURE PREVAILS WEDNESDAY INTO THURSDAY. A LOW PRESSURE
SYSTEM MOVING ACROSS CENTRAL PENNSYLVANIA ON THURSDAY WILL DRAG A
WEAK FRONT OVER THE AREA THURSDAY NIGHT INTO FRIDAY MORNING.
&&
.MARINE...
SW WINDS TODAY WILL BECOME BREEZY BY THIS AFTERNOON AS A COLD FRONT
APPROACHES THE REGION. EXPECT WINDS TO SHIFT TO THE W THIS EVENING...
BECOMING NW-N BEHIND THE FRONT AS IT TRACKS FROM NORTHWEST TO
SOUTHEAST ACROSS THE WATERS. CAA STILL DOES NOT APPEAR TO BE VERY
STRONG BUT A PROLONGED PERIOD OF NLY WINDS INTO WED HAS PROMPTED
THE ISSUANCE OF SCA FLAGS THROUGH EARLY WED MORNING. WINDS OVER
THE BAY/SOUND SHOULD TOP OUT AROUND 25 KT WITH WAVES OF 2-3 FT AND
UP TO 4 FT AT TIMES. NRN OCEAN WATERS WILL FIRST EXPERIENCE GUSTS
OF 25 KT AND SEAS OF 3-5 FT...WHILE SRN OCEAN WATERS WILL SEE
GUSTS OF 25 KT AFTER MIDNIGHT AND SEAS OF GENERALLY 2-4 FT.
HIGH PRESSURE BUILDS IN FROM THE NORTHWEST ON WED AND THE GRADIENT
RELAXES. WINDS WILL THEN VEER TO THE S-SW LATE WED NIGHT THROUGH FRI
AS A LOW PRESSURE SYSTEM MOVING ACROSS CENTRAL PENNSYLVANIA DRAGS A
WEAK FRONT ACROSS THE WATERS THURSDAY NIGHT INTO FRIDAY MORNING.
SEAS WILL GENERALLY BE 2-3 FT (OCCASIONALLY 4 FT NEAR 20 NM) AND
WAVES 1-2 FT (INCREASING TO 3 FT AT TIMES...ESPECIALLY DURING THE
OVERNIGHT HOURS DUE TO DIURNAL INSTABILITY EFFECTS).
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NCZ012>017-
030>032.
VA...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR VAZ087>097.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 9 AM EDT
WEDNESDAY FOR ANZ638-650-652-654.
SMALL CRAFT ADVISORY FROM 2 AM TO 9 AM EDT WEDNESDAY FOR
ANZ633-656-658.
SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
WEDNESDAY FOR ANZ630>632-634.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAS/MAM
SHORT TERM...MAS/MAM
LONG TERM...ALB
AVIATION...BMD
MARINE...BMD
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1205 PM EDT TUE JUL 24 2012
.SYNOPSIS...
A COLD FRONT, MOVING SOUTHWARD THROUGH THE UPPER OHIO VALLEY, CAN
STILL CAUSE SCATTERED THUNDERSTORMS, WITH GUSTY WIND, HAIL, AND
HEAVY RAIN, INTO EARLY EVENING, MAINLY SOUTH OF THE INTERSTATE
80 CORRIDOR. ANOTHER FRONT WILL BRING SCATTERED THUNDERSTORMS
THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
RECENT RADAR AND SURFACE DATA SHOW ADDITIONAL PREFRONTAL
SCATTERED SHOWERS AND THUNDERSTORMS WILL BE MOVING SOUTHEASTWARD
ACROSS THE UPPER OHIO VALLEY SOUTH OF I-80 INTO EARLY EVENING.
SOME STORMS CAN HAVE GUSTY WIND, HAIL, HEAVY RAIN, AND FREQUENT
LIGHTNING. SPC HAS INDICATED STORMS CAN REACH SEVERE LIMITS.
THUNDERSTORMS CAN BE SCATTERED AS FAR NORTH AS THE NEW
PHILADELPHIA-PITTSBURGH CORRIDOR THIS AFTERNOON. HIGH TEMPERATURES
HAVE BEEN TRIMMED BY 1-2 DEGREES DUE TO EVAPORATIVE-COOLING
EFFECTS OF THIS MORNINGS RAINFALL.
EXPECT POSTFRONTAL NORTHWESTERLY WINDS TO END REMAINING SHOWERS
THIS EVENING, AND PROVIDE LOWER DEW POINTS. WILL CONSIDER LATE
NIGHT FOG PROSPECTS WITH NEXT UPDATE.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
TODAY/S FRONT SHOULD LIFT BACK TO THE NORTH WEDNESDAY AND WEDNESDAY
NIGHT AS A WARM FRONT. STILL UNSURE AS TO JUST HOW PRECIPITATION THE
FRONT WILL GENERATE ON ITS RETURN TRIP. 00Z MODEL RUNS HAVE
ACCELERATED THE WARM FRONT PASSAGE...AND NOW SHOW THAT THE FRONT
WILL LIKELY MOVE THROUGH WEDNESDAY EVENING. THIS TIMING SHOULD LIMIT
DIURNAL ENHANCEMENT OF SHOWERS/STORMS. THE FASTER TIMING WILL ALSO
KEEP WEDNESDAY NIGHT LOWS A BIT HIGHER AS WELL WITH THE REGION
RETURNING TO THE WARM SECTOR MORE QUICKLY.
LOW PRESSURE WILL TRACK FROM LOWER MICHIGAN TOWARDS NEW ENGLAND ON
THURSDAY...DRAGGING A COLD FRONT TO THE SOUTHEAST. WITH THE FRONT
SLIDING THROUGH THE REGION SLOWLY...THIS COULD PROVIDE AN EXTENDED
PERIOD FOR SHOWERS AND STORMS FOR ALL OF THURSDAY AND FRIDAY. ANY
POTENTIAL FOR SEVERE WEATHER ON THURSDAY WILL BE DEPENDENT ON
LOCATION OF THE FRONT. FOR NOW...SPC HAS DEPICTED A BROAD AREA FOR
SEVERE POTENTIAL ON THURSDAY..INCLUDING THE ENTIRE FORECAST AREA.
THURSDAY APPEARS TO BE THE WARMEST DAY WHILE THE REGION IS IN THE
WARM SECTOR...WITH TEMPERATURES AROUND 90. TEMPS SHOULD BE SEASONAL
FOR WEDNESDAY AND FRIDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
LATEST MEDIUM RANGE MODELS STILL DIG A SHORT WAVE TROUGH ACROSS THE
GREAT LAKES REGION FRIDAY AND SLOWLY MOVE THE TROUGH AXIS MOVE EAST
TO THE NEW ENGLAND COAST BY MONDAY.
KEPT SCATTERED SHOWERS AND THUNDERSTORMS IN THE FORECAST FRIDAY
NIGHT AND SATURDAY...WITH DRY WEATHER EXPECTED SUNDAY INTO MONDAY
AS THE UPPER TROUGH MOVES EAST AND A WEAK SURFACE HIGH BRINGS
DRIER AIR IN FROM THE NORTHWEST.
FORECAST TEMPERATURES ARE CLOSE TO HPC GUIDANCE AND NEAR NORMAL
THROUGH THE EXTENDED PERIOD.
&&
.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
PER RECENT SURFACE AND RADAR DATA, COUPLED WITH HRRR MODEL OUTPUT,
MAINTAINED MENTION OF TEMPO MVFR RESTRICTIONS WITH SHOWERS AND
SCATTERED THUNDERSTORMS KZZV-KPIT AND SOUTH. SURFACE WINDS WILL
BECOME NORTHWEST NEAR 10 KTS WITH GUSTS TO 20 KTS. HIGHER GUSTS
POSSIBLE NEAR THUNDERSTORMS.
POSTFRONTAL DRYING WILL PROMOTE VFR STARTING THIS EVENING.
POTENTIAL FOR LATE NIGHT PATCHY FOG MAY PRODUCE RESTRICTIONS, BUT
NOT ENOUGH CONFIDENCE TO MENTION IN TAF.
OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
GEN VFR...BUT WITH PERIODIC CHCS FOR TSRA/ASSOCIATED RESTRICTIONS
ARE EXPECTED FOR THE REMAINDER OF THE WEEK AS A SERIES OF SHRTWVS
TRACK ACRS THE UPR OH VALLEY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1022 AM EDT TUE JUL 24 2012
.SYNOPSIS...
A COLD FRONT, MOVING SOUTHWARD THROUGH THE UPPER OHIO VALLEY, CAN
STILL CAUSE SCATTERED THUNDERSTORMS INTO EARLY EVENING, MORE SO
SOUTH OF THE INTERSTATE 70 CORRIDOR THAN NORTH. ANOTHER FRONT
WILL BRING SCATTERED THUNDERSTORMS THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
RECENT RADAR AND SURFACE DATA SHOW THE INITIAL BATCH OF SEVERE
THUNDERSTORMS HAS EXITED EAST PAST THE APPALACHIAN MOUNTAINS,
WHILE ADDITIONAL PREFRONTAL SCATTERED SHOWERS AND THUNDERSTORMS
WERE MOVING SOUTHEASTWARD ACROSS EAST CENTRAL OHIO.
USING THIS DATA AS WELL AS RECENT HRRR AND WRF-NMM MODEL OUTPUT, HAVE
ACCORDINGLY ADJUSTED MENTION OF THUNDERSTORM COVERAGE, AND
TEMPERATURES THROUGH AFTERNOON.
THUNDERSTORMS CAN BE SCATTERED AS FAR NORTH AS THE NEW
PHILADELPHIA-PITTSBURGH CORRIDOR THIS AFTERNOON. HIGH TEMPERATURES
HAVE BEEN TRIMMED BY 1-2 DEGREES DUE TO EVAPORATIVE-COOLING
EFFECTS OF THIS MORNINGS RAINFALL.
EXPECT POSTFRONTAL NORTHWESTERLY WINDS TO END REMAINING SHOWERS
THIS EVENING, AND PROVIDE LOWER DEW POINTS. WILL CONSIDER LATE
NIGHT FOG PROSPECTS WITH NEXT UPDATE.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
TODAY/S FRONT SHOULD LIFT BACK TO THE NORTH WEDNESDAY AND WEDNESDAY
NIGHT AS A WARM FRONT. STILL UNSURE AS TO JUST HOW PRECIPITATION THE
FRONT WILL GENERATE ON ITS RETURN TRIP. 00Z MODEL RUNS HAVE
ACCELERATED THE WARM FRONT PASSAGE...AND NOW SHOW THAT THE FRONT
WILL LIKELY MOVE THROUGH WEDNESDAY EVENING. THIS TIMING SHOULD LIMIT
DIURNAL ENHANCEMENT OF SHOWERS/STORMS. THE FASTER TIMING WILL ALSO
KEEP WEDNESDAY NIGHT LOWS A BIT HIGHER AS WELL WITH THE REGION
RETURNING TO THE WARM SECTOR MORE QUICKLY.
LOW PRESSURE WILL TRACK FROM LOWER MICHIGAN TOWARDS NEW ENGLAND ON
THURSDAY...DRAGGING A COLD FRONT TO THE SOUTHEAST. WITH THE FRONT
SLIDING THROUGH THE REGION SLOWLY...THIS COULD PROVIDE AN EXTENDED
PERIOD FOR SHOWERS AND STORMS FOR ALL OF THURSDAY AND FRIDAY. ANY
POTENTIAL FOR SEVERE WEATHER ON THURSDAY WILL BE DEPENDENT ON
LOCATION OF THE FRONT. FOR NOW...SPC HAS DEPICTED A BROAD AREA FOR
SEVERE POTENTIAL ON THURSDAY..INCLUDING THE ENTIRE FORECAST AREA.
THURSDAY APPEARS TO BE THE WARMEST DAY WHILE THE REGION IS IN THE
WARM SECTOR...WITH TEMPERATURES AROUND 90. TEMPS SHOULD BE SEASONAL
FOR WEDNESDAY AND FRIDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
LATEST MEDIUM RANGE MODELS STILL DIG A SHORT WAVE TROUGH ACROSS THE
GREAT LAKES REGION FRIDAY AND SLOWLY MOVE THE TROUGH AXIS MOVE EAST
TO THE NEW ENGLAND COAST BY MONDAY.
KEPT SCATTERED SHOWERS AND THUNDERSTORMS IN THE FORECAST FRIDAY
NIGHT AND SATURDAY...WITH DRY WEATHER EXPECTED SUNDAY INTO MONDAY
AS THE UPPER TROUGH MOVES EAST AND A WEAK SURFACE HIGH BRINGS
DRIER AIR IN FROM THE NORTHWEST.
FORECAST TEMPERATURES ARE CLOSE TO HPC GUIDANCE AND NEAR NORMAL
THROUGH THE EXTENDED PERIOD.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
PER RECENT SURFACE AND RADAR DATA, COUPLED WITH HRRR MODEL OUTPUT,
MAINTAINED MENTION OF TEMPO MVFR RESTRICTIONS WITH SHOWERS AND
SCATTERED THUNDERSTORMS KZZV-KPIT AND SOUTH. SURFACE WINDS WILL
BECOME NORTHWEST NEAR 10 KTS WITH GUSTS TO 20 KTS. HIGHER GUSTS
POSSIBLE NEAR THUNDERSTORMS.
POSTFRONTAL DRYING WILL PROMOTE VFR STARTING THIS EVENING.
POTENTIAL FOR LATE NIGHT PATCHY FOG MAY PRODUCE RESTRICTIONS, BUT
NOT ENOUGH CONFIDENCE TO MENTION IN TAF.
OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
GEN VFR...BUT WITH PERIODIC CHCS FOR TSRA/ASSOCIATED RESTRICTIONS
ARE EXPECTED FOR THE REMAINDER OF THE WEEK AS A SERIES OF SHRTWVS
TRACK ACRS THE UPR OH VALLEY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
608 AM EDT TUE JUL 24 2012
.SYNOPSIS...
AS A COLD FRONT MOVES THROUGH TODAY...SEVERE WEATHER COULD IMPACT
LOCATIONS TO THE SOUTH OF PITTSBURGH. ANOTHER FRONT WILL BRING
SCATTERED THUNDERSTORMS FOR THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
COLD FRONT IS CURRENTLY DRAPED ACROSS LOWER MICHIGAN...EXTENDING
EAST TO JUST NORTH OF LAKE ERIE. THE FRONT WILL DROP SOUTH THROUGH
THE REGION TODAY...WITH ENHANCEMENT PROVIDED BY AN UPPER LEVEL
SHORTWAVE THAT IS EXPECTED TO TRACK FROM WISCONSIN SOUTHEAST INTO
NORTH CAROLINA. WHILE EFFECTIVE SHEAR VALUES AROUND 30-35 KTS ARE
EXPECTED TO TRACK ALONG THE FRONT...MODERATE CAPE VALUES WILL
PRIMARILY REMAIN SOUTH OF THE MASON-DIXON LINE. AS A RESULT...THINK
THAT BEST LOCAL POTENTIAL FOR SEVERE WILL REMAIN GENERALLY SOUTH OF
A LINE FROM ZANESVILLE TO MORGANTOWN. HOWEVER...IMPORTANT TO NOTE
THAT SPC SLIGHT RISK FOR SEVERE WEATHER INCLUDES ALL LOCATIONS SOUTH
OF A LINE FROM NEW PHILADELPHIA TO WHEELING AND LATROBE. WITH THE
SHORTWAVE RACING SOUTHEAST...BEST CHANCE FOR ANY PRECIPITATION
SHOULD BE LATE MORNING AND THE EARLY AFTERNOON...PROVIDING ANOTHER
POTENTIAL LIMITING FACTOR FOR SEVERE WEATHER. EXPECT DRY
CONDITIONS EVERYWHERE TONIGHT...AND MUCH COOLER/DRIER AIR. LOWS
SHOULD DROP INTO THE 50S IN ALL LOCATIONS.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
TODAY/S FRONT SHOULD LIFT BACK TO THE NORTH WEDNESDAY AND WEDNESDAY
NIGHT AS A WARM FRONT. STILL UNSURE AS TO JUST HOW PRECIPITATION THE
FRONT WILL GENERATE ON ITS RETURN TRIP. 00Z MODEL RUNS HAVE
ACCELERATED THE WARM FRONT PASSAGE...AND NOW SHOW THAT THE FRONT
WILL LIKELY MOVE THROUGH WEDNESDAY EVENING. THIS TIMING SHOULD LIMIT
DIURNAL ENHANCEMENT OF SHOWERS/STORMS. THE FASTER TIMING WILL ALSO
KEEP WEDNESDAY NIGHT LOWS A BIT HIGHER AS WELL WITH THE REGION
RETURNING TO THE WARM SECTOR MORE QUICKLY.
LOW PRESSURE WILL TRACK FROM LOWER MICHIGAN TOWARDS NEW ENGLAND ON
THURSDAY...DRAGGING A COLD FRONT TO THE SOUTHEAST. WITH THE FRONT
SLIDING THROUGH THE REGION SLOWLY...THIS COULD PROVIDE AN EXTENDED
PERIOD FOR SHOWERS AND STORMS FOR ALL OF THURSDAY AND FRIDAY. ANY
POTENTIAL FOR SEVERE WEATHER ON THURSDAY WILL BE DEPENDENT ON
LOCATION OF THE FRONT. FOR NOW...SPC HAS DEPICTED A BROAD AREA FOR
SEVERE POTENTIAL ON THURSDAY..INCLUDING THE ENTIRE FORECAST AREA.
THURSDAY APPEARS TO BE THE WARMEST DAY WHILE THE REGION IS IN THE
WARM SECTOR...WITH TEMPERATURES AROUND 90. TEMPS SHOULD BE SEASONAL
FOR WEDNESDAY AND FRIDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
LATEST MEDIUM RANGE MODELS STILL DIG A SHORT WAVE TROUGH ACROSS THE
GREAT LAKES REGION FRIDAY AND SLOWLY MOVE THE TROUGH AXIS MOVE EAST
TO THE NEW ENGLAND COAST BY MONDAY.
KEPT SCATTERED SHOWERS AND THUNDERSTORMS IN THE FORECAST FRIDAY
NIGHT AND SATURDAY...WITH DRY WEATHER EXPECTED SUNDAY INTO MONDAY
AS THE UPPER TROUGH MOVES EAST AND A WEAK SURFACE HIGH BRINGS
DRIER AIR IN FROM THE NORTHWEST.
FORECAST TEMPERATURES ARE CLOSE TO HPC GUIDANCE AND NEAR NORMAL
THROUGH THE EXTENDED PERIOD.
&&
.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
SHRTWV IN NW FLOW WL SUPPORT MOIST...DEEP CONVECTION ALONG SWD SAGGING
CDFNT TODAY. THIS WEATHER IS EXPECTED TO AFFECT PORTS FM PIT SWD
WITH MVFR/ISOLD IFR CONDITIONS AND TAFS HAVE BEEN CONSTRUCTED
ACCORDINGLY USING THE LATEST HRRR TIMING AND GENL PLACEMENT.
OTHERWISE SFC WND WL VEER TO THE W AND NW WITH PASSAGE OF THE SFC
REFLECTION. BUILDING SFC HIGH IS EXPECTED TO RESULT IN VFR
CONDITIONS AT ALL PORTS BY LATE AFTN.
OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
GENL VFR...BUT WITH PERIODIC CHCS FOR TSRA/ASSOCIATED RESTRICTIONS
ARE EXPECTED FOR THE REMAINDER OF THE WEEK AS A SERIES OF SHRTWVS
TRACK ACRS THE UPR OH VALLEY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
610 PM CDT WED JUL 25 2012
.UPDATED FOR 00Z AVIATION DISCUSSION BELOW...
.DISCUSSION.../ISSUED 259 PM CDT WED JUL 25/
THE MAIN ISSUE IN THE SHORT TERM IS OBVIOUSLY THE CHANCES FOR
SHRA/TSRA LATE THIS AFTERNOON INTO THIS EVENING AS THE SURFACE LOW
SLIDES EAST AND THE FRONTAL BOUNDARY DROPS THROUGH THE AREA. LATEST
MSAS ANALYSIS AND SURFACE OBS SHOW A WELL DEFINED WIND SHIFT
CURRENTLY BISECTING THE FORECAST AREA FROM SOUTHWEST TO NORTHEAST...
AND SOME CONVECTION HAS TRIED TO DEVELOP NEAR THIS OVER THE PAST
SEVERAL HOURS... BUT HAS THUS FAR BEEN UNSUCCESSFUL. THE ACTUAL
FRONTAL BOUNDARY IS STILL WELL TO THE WEST OVER THE DAKOTAS... WHERE
THE DEWPOINT GRADIENT CAN BE FOUND. THIS WILL EVENTUALLY BE PUSHED
EAST THIS EVENING AS THE MAIN UPPER SHORTWAVE CURRENTLY SEEN NEAR
THE SASKATCHEWAN/MANITOBA BORDER PUSHES SOUTHEAST. AT THIS POINT...
IT/S QUESTIONABLE AS TO WHETHER THE FORCING ASSOCIATED WITH THE
ACTUAL UPPER WAVE AND COLD FRONTAL BOUNDARY WILL MANAGE TO GET ANY
CONVECTION GOING. CONTINUED CHANCE POPS THROUGH THE REMAINDER OF THE
AFTERNOON OVER THE WESTERN CWFA TO ACCOUNT FOR THAT POSSIBILITY.
OTHERWISE... TIED PCPN CHANCES TO THE INITIAL WIND SHIFT CURRENTLY
DROPPING THROUGH THE AREA... WHICH WILL BE INTERACTING WITH AN AREA
OF MLCAPE AOA 1500 J/KG. A SUBTLE SHORTWAVE FEATURE EVIDENT ON WATER
VAPOR... AND APPARENT IN THE RAP 400-300MB PV ANALYSIS... IS
CURRENTLY LIFTING NORTHEAST FROM EASTERN NEBRASKA... AND MAY HELP TO
GET ACTIVITY GOING NEAR THE WIND SHIFT DURING THE LATE AFTERNOON
OVER THE SOUTHERN AND SOUTHEAST PORTION OF THE FORECAST AREA. SO
OVERALL... KEPT CHANCE POPS OVER THE ENTIRE AREA FOR THE REMAINDER
OF THE AFTERNOON... THEN TRANSITIONED CHANCES SOUTH AND EAST THROUGH
THE EVENING.
CHANCES FOR PCPN DEPART TO THE EAST OVERNIGHT TONIGHT AS THE SURFACE
LOW AND FRONT CONTINUE TO PUSH EAST AND A WEAK SURFACE RIDGE MOVES
INTO THE AREA. THE MAIN UPPER TROUGH DROPS TOWARD THE AREA
TOMORROW... ALONG WITH A SECONDARY SURFACE WAVE AND COLD FRONTAL
BOUNDARY. WITH THE MID-UPPER COLD POOL MOVING INTO THE AREA...
TOGETHER WITH SOME LOW LEVEL CONVERGENCE ASSOCIATED WITH THE SURFACE
LOW AND FRONTAL BOUNDARY... WE SHOULD SEE SOME SCATTERED SHRA/TSRA
DROP SOUTHEAST ACROSS MUCH OF THE AREA FROM LATE MORNING THROUGH THE
AFTERNOON HOURS. THE BEST CHANCES WILL BE OVER THE NORTHERN AND
NORTHEAST PART OF THE AREA... BUT CAN/T RULE OUT SOME SHRA/TSRA AS
FAR SOUTH AS THE MINNESOTA RIVER VALLEY DURING THE AFTERNOON HOURS
DEPENDING UPON THE DEGREE OF DESTABILIZATION WHICH OCCURS FARTHER
SOUTH AWAY FROM THE HEART OF THE MID-LEVEL COLD POOL.
ON THURSDAY NIGHT... SCATTERED SHOWERS SHOULD DIMINISH
AROUND/AFTER SUNSET WITH THE LOSS OF DAYTIME HEATING. BY
FRIDAY... ANY RESIDUAL ACTIVITY SHOULD BE CONFINED TO WEST CENTRAL
WI COUNTIES NORTH OF INTERSTATE 94... AND THE WARRANTED COVERAGE
SHOULD ONLY BE 20 PERCENT. H85 TEMPS COOL TO AROUND +12C TO +13C
ON FRIDAY... SO HIGHS IN THE MID 70S TO LOWER 80S RANGE APPEAR
REASONABLE WITH SCT-BKN MID CLOUDS AROUND.
DRY AND NEAR NORMAL TEMPERATURES ARE EXPECTED FOR FRIDAY NIGHT AND
SATURDAY AFTER THE EXODUS OF THE TROUGH.
SATURDAY NIGHT AND SUNDAY WILL ARRIVE WITH THE NEXT OPPORTUNITY
FOR MEASURABLE PRECIPITATION... AS MULTIPLE WEAK SHORTWAVES TOP
THE PLAINS MID LEVEL RIDGE. RELATIVELY LOW CONFIDENCE ON WHETHER
FORCING ASSOCIATED WITH THE WAVES WILL BE SUFFICIENT TO OVERCOME
DRY/WARM AIR AT MID LEVELS... SO 30-40 POPS ARE AS HIGH AS WE WILL
GO FOR NOW.
FOR MONDAY THROUGH WEDNESDAY... HIGHS FROM 85-90 ARE
EXPECTED... ALONG WITH LOWS FROM THE MID 60S TO LOWER 70S. THE
PROXIMITY OF THE RIDGE AND MEAN WESTERLY/NORTHWESTERLY FLOW WILL
COMPLICATE THE PRECIPITATION FORECAST NEXT WEEK. HAVE OPTED TO GO
DRY AT THIS POINT SINCE CONFIDENCE/PROBABILITY ARE LOW AT THIS
TIME.
&&
.AVIATION.../00Z TAF ISSUANCE/
COUPLE OF AREAS OF CONVECTION TO WATCH...BUT MOST WILL NOT AFFECT
TAF SITES INTO THE EVENING. FIRST BOUNDARY SAGGING INTO SOUTH
CENTRAL MN AND SOUTH OF KEAU. SOME POST FRONTAL ACCAS CONTINUES TO
SPILL NORTHEAST OVER SOUTHERN TAF ROUTES...SO WILL HAVE TO MENTION
SOME VCSH AT LEAST. OTHER BOUNDARY/FRONT ASSOCIATED WITH DRIER AIR
MOVING OVER EASTERN DAKOTAS NORTHWEST MN WITH SOME WIDELY SCATTERED
CONVECTION. THIS MAY WORK INTO KAXN AREA EARLY...SO WILL MENTION
VCSH FOR THAT. OTHERWISE...SHOULD WEAKEN AFTER 01Z OR SO. CLOUDS
EXPECTED TO THIN SOME OVERNIGHT WITH SOME PATCHY FOG POSSIBLE. LEFT
IT IN AT WIS TAF SITES AND KSTC FOR NOW. WINDS WILL INCREASE THU
MORNING AHEAD OF/BEHIND COLD FRONT WITH BEST SHOT OF -SHRA/ISOLD
TSRA OVER NORTHEAST AREAS. WILL MENTION PROB30 AT KSTC/KRNH FOR NOW
AND LEAVE THUNDER OUT...DEVELOPING AFTER 19Z. NORTHWEST WINDS MAY
BE A BIT GUSTY...ESPECIALLY AFTER FROPA...MAINLY LESS THAN 25 KNOTS.
ACTIVITY EXPECTED TO WANE INTO EARLY EVENING OVER EASTERN AREAS.
KMSP... WILL MENTION VCSH FOR A FEW HOURS AS SOME MID LEVEL CLOUDS
MOVE ACROSS MAINLY THE SOUTHERN METRO. CLOUDS WILL THIN SOME LATER
BUT WITH MORE CUMULUS DEVELOPMENT ON THURSDAY AS UPPER TROUGH
APPROACHES. WILL CONTINUE TREND OF VCSH 20Z-01Z FOR NOW. COULD BE
SOME THUNDER AS WELL...BUT WILL LEAVE OUT FOR NOW AS ANTICIPATE
IT SHOULD BE WIDELY SCATTERED IF IT DEVELOPS. NORTHWEST WINDS WITH
SECONDARY FROPA WILL BE A BIT GUSTY MAINLY AFTER 18Z THU...THEN
DIMINISH INTO THE EVENING.
//OUTLOOK FOR KMSP FOR THURSDAY NIGHT THROUGH MONDAY
THURSDAY NIGHT...SHRA AND MVFR CEILINGS AND VISIBILITIES POSSIBLE.
FRIDAY...MVFR CEILINGS POSSIBLE EARLY.
FRIDAY NIGHT THROUGH SATURDAY...VFR EXPECTED.
SATURDAY NIGHT THROUGH SUNDAY...BRIEF MVFR CEILINGS VISIBILITIES
POSSIBLE WITH SHRA/TSRA.
SUNDAY NIGHT AND MONDAY...VFR EXPECTED.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
LRS/DE
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
504 PM MDT WED JUL 25 2012
.AVIATION...
00Z TAF CYCLE
DRIER AIR ALOFT HAS PUSHED INTO PORTIONS OF WESTERN NEW
MEXICO...AS A HIGH CENTER ALOFT WAS LOCATED OVER ARIZONA. MOIST
AND UNSTABLE AIR PERSISTS FROM THE CENTRAL MT CHAIN OVER THE
EASTERN PLAINS...AND STORM MOTION WILL BE FROM NORTH TO SOUTH IN
THE CIRCULATION ON THE EASTERN SIDE OF THE HIGH. IN ADDITION...A
SURFACE BOUNDARY STRETCHED OVER EAST CENTRAL NEW MEXICO AT 23Z MAY
SERVE AS A FOCUS FOR CONVECTION BEFORE 06Z. THIS BOUNDARY WILL
LIKELY SAG FARTHER SOUTH TO KROW BEFORE 12Z. GUSTY OUTFLOW WINDS
TO 35KT WILL BE THE MAIN IMPACT FROM CONVECTION OVER WESTERN
NM...WHILE HIGHER TERRAIN WILL BE OCCASIONALLY OBSCURED IN MVFR
CIG/VSBY FOR SHORT DURATIONS ELSEWHERE DUE TO TSRA. EXPECT ISOLD
CONVECTION TO CONTINUE OVER CENTRAL AND ERN NM 06Z-12Z.
&&
.DISCUSSION...253 PM MDT WED JUL 25 2012...
...POTENTIAL FOR LOCALLY HEAVY RAIN WILL CONTINUE THRU THE WEEKEND...
AFTERNOON RADAR AND SATELLITE TRENDS ALIGNING VERY WELL WITH THE LATEST
HIRES HRRR AND RUC13 MODELS...INCREASING CONFIDENCE THAT MAIN FOCUS FOR
HEAVY RAINFALL WILL BE ALONG AND EAST OF THE CENTRAL MT CHAIN INTO THIS
EVENING. PWAT VALUES PER CIRA IMAGERY ARE BTWN 1 AND 1.2 INCHES WHICH
IS 100-125 PCT OF NORMAL. A WELL DEFINED VORT MAX NEARLY STATIONARY OVER
THE EAST CENTRAL PLAINS WILL FOCUS WITH A BACK DOOR FRONT TO PRODUCE
SCT TO NMRS STORMS THIS EVENING. DRIER STABLE AIR WILL QUICKLY DIMINISH
MOST ACTIVITY FOR CENTRAL AND WESTERN AREAS BY MIDNIGHT.
THE BACK DOOR FRONTAL BNDRY WILL SLIDE INTO THE RIO GRANDE VALLEY TMRW
AFTERNOON AIDED BY CONVECTION ALONG THE EAST SLOPES. GAP WINDS ARE
EXPECTED MOST AREAS. MAIN FOCUS OF THETA-E RIDGE AXIS WILL BE OVER MANY
AREAS OF CENTRAL NM. PWAT VALUES CONTINUE TO RISE TO BTWN 1.2 AND
1.4 WHICH WILL POSE AND ELEVATED THREAT FOR FLASH FLOODING. STEERING
FLOW WILL BE WEAKEST AND MOST CONVERGENT ALONG THE CONT DVD THEREFORE
A WATCH IS POSSIBLE HOWEVER WILL DELAY TO FOLLOWING SHIFTS. HAVE RAISED
POPS SLIGHTLY MORE TO COVER HIGHER CHANCES FOR THE CENTRAL VALLEYS.
BY FRIDAY THE FOCUS SHIFTS TO THE WESTERN HALF OF THE STATE WHERE HEAVY
RAINFALL POTENTIAL CONTINUES. PWATS ADVERTISED BTWN 1.2 AND 1.4 AGAIN
WITH LOTS OF INSTABILITY. STEERING FLOW WILL BECOME MORE SW TO NE AND
SPEED UP TO NEAR 15KTS SO WHILE HEAVY RAINFALL IS LIKELY THE POTENTIAL
FOR FLASH FLOODING MAY BE LIMITED TO TRAINING CELLS. EXPECT ACTIVITY
TO SLIDE NORTHEAST ON OUTFLOWS TOWARD THE RIO GRANDE VALLEY EACH EVENING
IN THIS VERY MOIST STEERING PATTERN. MAX TEMPS WILL REMAIN VERY CLOSE
TO SEASONAL NORMS WHILE MIN TEMPS REMAIN 5 TO 10F ABOVE NORMAL. GUYER
&&
.FIRE WEATHER...
AS ADVERTISED THE MAIN WETTING STORM FOCUS WILL SHIFT FROM THE
WESTERN HALF LIKE WAS SEEN YESTERDAY TO THE EASTERN HALF TODAY. A
BACK DOOR COLD FRONT HAS CUT INTO THE NORTHEAST PLAINS AND HAS
CREATED ABUNDANT STORM COVERAGE ACROSS THE SANGRE DE CRISTOS.
STORMS WILL TEND TO DRIFT OFF TO THE SOUTHEAST AND IMPACT THE
EASTERN PLAINS TONIGHT. WITH THE BOUNDARY AROUND...LOOK FOR
CONTINUED ABUNDANT RAINFALL ACROSS THE CENTRAL MOUNTAINS AND LARGE
PORTIONS OF THE EASTERN PLAINS ON THURSDAY. MORE ISOLATED ACTIVITY
WILL BE FOUND ACROSS THE WEST DURING THE NEXT 36 HOURS AS DRIER
AIR FILTERS IN. LOOKING AT SOME TEEN HUMIDITIES ACROSS THE FOUR
CORNERS AREA BY THURSDAY. HIGH TEMPERATURES WILL BE NEAR NORMAL
ALTHOUGH PERHAPS A FEW DEGREES BELOW NORMAL ACROSS THE NORTHEAST
ON THURSDAY.
BACK DOOR FRONT WILL INFILTRATE THE RIO GRANDE VALLEY LATER TONIGHT
BUT MAKE MORE OF A PUSH WESTWARD UNDERNEATH THE UPPER HIGH THURSDAY
NIGHT INTO FRIDAY MORNING. THIS WILL PUSH THE FOCUS OF WETTING
STORMS BACK TO THE WEST ON FRIDAY. ESPECIALLY FAVORING THE
CONTINENTAL DIVIDE REGION AS DEPICTED BY THE GFS AND TO A LESSER
EXTENT THE ECMWF AND NAM. THIS SHOULD BE THE REPLENISHMENT OF
MOISTURE THAT IS NEEDED TO FUEL HIGHER COVERAGE OF WETTING STORMS
ACROSS THE WESTERN HALF.
IT APPEARS THAT A CONSOLIDATED UPPER HIGH...BOTH BERMUDA AND
SUBTROPICAL...SHOULD BE FOUND OVER THE RED RIVER VALLEY BETWEEN TX
AND OK DURING THE WEEKEND AND EARLY NEXT WEEK. MODELS ARE SHOWING A
NICE MONSOONAL PLUME SIGNATURE OVER THE WESTERN THIRD TO HALF OF THE
FORECAST AREA DURING THIS PERIOD...ESPECIALLY DURING THE WEEKEND
TIME FRAME. PERHAPS SOME SUBSIDENCE/MID LVL DRY SLOT EFFECTS OVER THE
EASTERN PLAINS ALTHOUGH STEERING FLOW BY EARLY NEXT WEEK COULD TAKE
STORMS OFF THE CENTRAL MTNS INTO THE EASTERN PLAINS LATER IN THE DAY
PERIOD.
BOTH ECMWF AND GFS TREND THE UPPER HIGH CENTER BACK OVER THE STATE
AS NEXT WEEK PROGRESSES. THIS WOULD ESSENTIALLY STEER THE MONSOONAL
PLUME FURTHER WEST BUT COULD ALSO BRING ANOTHER BACK DOOR COLD FRONT
INTO THE EQUATION.
EITHER WAY...UNSETTLED WEATHER EXPECTED THROUGH THE NEXT SEVERAL
DAYS WITH THE INITIAL FOCUS ACROSS THE EASTERN HALF BUT
TRANSITIONING WESTERN HALF AS THE WEEK PROGRESSES INTO THE
WEEKEND. 50
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS RALEIGH NC
225 AM EDT TUE JUL 24 2012
.SYNOPSIS...
A SERIES OF UPPER LEVEL DISTURBANCES WILL CROSS THE MID ATLANTIC
REGION THROUGH TUESDAY NIGHT...PRODUCING SCATTERED THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1015 PM MONDAY...
AN UPPER LEVEL WAVE ALONG WITH MERGING OUTFLOWS HELPED TO PRODUCE A
BROKEN LINE OF CONVECTION THAT WAS RESPONSIBLE FOR SEVERAL SEVERE
STORMS THIS EVENING...WHICH HAS NOW PUSHED EAST OF THE CWA.
ADDITIONAL SHOWERS AND THUNDERSTORMS WERE MOVING OFF OF THE HIGHER
TERRAIN OF VIRGINIA AROUND SUNSET BUT HAVE SINCE DISSIPATED WITH
STABILIZATION AND SUBSIDENCE IN THE WAKE OF THE UPPER WAVE. WATER
VAPOR IMAGERY LOOKS TO BE VOID OF ANY ADDITIONAL UPPER LEVEL
DISTURBANCES FOR THE OVERNIGHT PERIOD...SO THERE SHOULD NOT BE
MORE THAN AN ISOLATED SHOWER OR THUNDERSTORM OR TWO ON A REMNANT
OUTFLOW...MAINLY PRIOR TO 06Z. SOME CLEARING IS EVIDENT OVER
VIRGINIA ON INFRA RED IMAGERY... AND RAP RH CROSS SECTIONS SUGGEST
ENOUGH NEAR SURFACE MOISTURE FOR FOG TO DEVELOP. HOWEVER...A LIGHT
SOUTHERLY WIND SHOULD STIR ENOUGH TO KEEP PATCHY FOG LIMITED TO
AREAS WHERE RAIN WAS PARTICULARLY HEAVY...MAINLY SOUTHEAST OF THE
TRIANGLE. STRATUS IS ALSO NOT FORECAST BY THE MODELS BUT IT WOULD
NOT BE SURPRISING TO SEE SOME DEVELOP OVER THE COASTAL PLAIN IN
THE WAKE OF THE RAINFALL. OTHERWISE..THE ONLY CHANGES TO THE
FORECAST WERE TO TRIM LOWS SLIGHTLY ACROSS THE NORTH WHERE SKIES
MAY CLEAR OFF AND DEWPOINTS ARE SLIGHTLY LOWER...70 TO 74 NORTH
TO SOUTH.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 321 PM MONDAY...
TUESDAY AND TUESDAY NIGHT...ANOTHER IN A SERIES OF UPPER LEVEL
DISTURBANCES WILL APPROACH FROM THE NORTHWEST IN THE MORNING AND
AFFECT CENTRAL TUESDAY AFTERNOON AND TUESDAY NIGHT. MID LEVEL
SHEAR A TAD BETTER THAN THIS AFTERNOON WHICH SUGGEST BETTER CHANCE
FOR STRONG/DAMAGING WIND GUSTS WITH THE STRONGEST CONVECTION.
APPEARS TO BE ENOUGH AMPLE TIME IN THE MORNING THROUGH EARLY
AFTERNOON FOR STRONG INSOLATION TO ACHIEVE SURFACE BASED CAPE
VALUES 4000 TO 5000 J/KG AND MIXED LAYER CAPE 2500 TO 3500 J/KG.
INSTABILITY ALOFT SUGGEST POTENTIAL FOR DAMAGING WIND GUSTS AND
MARGINALLY SEVERE HAIL. IN ADDITION...A FEW OF THE STORMS COULD
PRODUCE A LARGE AMOUNT OF LIGHTNING.
WITH LOW LEVEL THICKNESSES COMPARABLE TO TODAY...EXPECT SIMILAR
TEMPERATURES TUESDAY AFTERNOON IN THE MID 90S...THOUGH COULD BE A
TOUCH COOLER IF CLOUDS COME IN SOONER OR THICKER IN THE
NORTHWEST PIEDMONT.
CONVECTION WILL SLOWLY DIMINISH TUESDAY EVENING WITH BULK OF
ACTIVITY AFTER MIDNIGHT EXPECTED OVER THE SOUTHERN COUNTIES THOUGH
APPROACH OF ANOTHER DISTURBANCE IN THE NORTHWEST FLOW MAY SPARK A
FEW SHOWERS IN THE NORTHWEST PIEDMONT AFTER 2 AM. MINIMUM
TEMPERATURES 69 TO 74. -WSS
NORTHWEST MID LEVEL FLOW WILL BE DIRECTED INTO THE AREA ON
WEDNESDAY...WITH PERTURBATIONS IN THE SHEAR AXIS MOVING ACROSS THE
AREA DURING THE DAY. MEANWHILE...WEAK AND COOLER SURFACE HIGH
PRESSURE BUILDS BRIEFLY INTO THE REGION...WITH DRIER NORTHERLY FLOW
EDGING INTO THE NORTHERN TIER. WILL CONTINUE A CHANCE POP GRADUATED
HIGHER SOUTH. LOW LEVEL THICKNESSES SUGGESTS THAT HIGH
TEMPERATURES WILL BE MOSTLY IN THE LOW 90S. DRYING CONTINUES
WITH A TRANSITION TO LOW AMPLITUDE RIDGING WEDNESDAY NIGHT...COULD
ARGUE FOR A LINGERING SLIGHT CHANCE POP ACROSS THE SOUTH AND EAST
EARLY WEDNESDAY NIGHT... NOT ENOUGH CONSISTENCY TO INCLUDE AT THIS
POINT. MINIMUM TEMPERATURES WILL BE PERSISTENCE...70 TO 75. -MLM
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 100 PM MONDAY...
THE INITIAL EXTENDED FORECAST STARTS OUT THURSDAY WITH A FAMILIAR
PATTERN...SURFACE LEE TROUGH OVER CENTRAL NORTH CAROLINA AND WESTERLY FLOW
ALOFT. THE RESULTING HIGH INSTABILITY (HIGHS 92 TO 96) BUT LACK
OF FORCING MECHANISMS ARE CONDUCIVE TO WIDELY SCATTERED DIURNAL
CONVECTION... WITH SLIGHT NODS FOR HIGHER POPS IN THE WEST WHERE
DIFFERENTIAL HEATING AND EASTWARD DRIFT OF SUBSEQUENT
CONVECTION... AND SEA BREEZE PENETRATION INTO THE COASTAL PLAIN.
A FRONT SAGGING SOUTH LATER FRIDAY OR FRIDAY NIGHT WILL PROVIDE SOME
ENHANCED LOW LEVEL CONVERGENCE W/ENHANCED CONVECTIVE CHANCES AS IT
WILL BE ACCOMPANIED BY SHARPENING OF AN UPPER TROUGH OVER THE EASTERN
CONUS. WILL CONTINUE CHANCE POPS FRIDAY AND SLIGHT CHANCES FRIDAY
NIGHT WITH FRONTAL PASSAGE CURRENTLY FORECAST FRIDAY NIGHT...
WHICH WOULD BE LEAST FAVORABLE STABILITY WISE. HIGHS FRIDAY WILL
REACH THE LOW TO MID 90S.
UPPER TROUGH WILL BE IN PLACE SATURDAY AND MIGRATING SLOWLY EAST
THROUGH MONDAY...WITH ATTENDANT NORTHWEST FLOW. TEMPERATURES WILL BE
SEASONABLE... LOW 90S AFTER MORNING LOWS 70 TO 75. CONVECTION
WILL BE MAINLY DRIVEN BY SMALLER SCALE PERTURBATIONS IN THE MID
LEVEL FLOW... WHICH OF COURSE ARE NOT FORECASTABLE THIS EARLY IN
THE GAME.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 220 AM...
ONLY VERY LOCALIZED MVFR FOG THIS MORNING. AN ISOLATED THUNDERSTORM
POSSIBLE THROUGH THE MORNING. EXPECTING THUNDERSTORMS TO DROP OUT
OF VIRGINIA THIS AFTERNOON AND SWEEP ACROSS CENTRAL NORTH
CAROLINA... EXITING AFTER MIDNIGHT. SOUTHWEST TO WEST WIND 10 TO
12 MPH BY MID MORNING... CONTINUING INTO LATE AFTERNOON.
MOSTLY MVFR FOG DEVELOPING LATE TONIGHT AS WINDS SUBSIDE. THEN A
DAILY THREAT FOR ISOLATED TO SCATTERED CONVECTION IN THE
AFTERNOON AND EVENING HOURS WITH ASSOCIATED MVFR CEILINGS AND
VISIBILITY. THERE WILL BE POCKETS OF MVFR TO IFR FOG AND STRATUS
BETWEEN 5 AM AND 9 AM EACH MORNING.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
NEAR TERM...SMITH/WSS
SHORT TERM...SMITH/WSS
LONG TERM...MLM
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1039 PM EDT WED JUL 25 2012
.SYNOPSIS...
A STRONG WARM FRONT LIFTING THROUGH INDIANA AND KENTUCKY WILL
CONTINUE NORTH AND EASTWARD TONIGHT ALLOWING VERY WARM AIR OVER
THE CENTRAL MISSISSIPPI VALLEY TO SPREAD INTO THE AREA TONIGHT.
THIS WARM FRONT MAY BE ACCOMPANIED BY A FEW THUNDERSTORMS DURING
THE NIGHT AS IT CROSSES THE AREA...BUT THE BIGGER STORY WILL COME
ON THURSDAY WHEN HEAT BUILDS AHEAD OF A COLD FRONT SAGGING INTO
THE GREAT LAKES. HEAT INDICES IN EXCESS OF 100 DEGREES ARE LIKELY
FOR MUCH OF THE AREA...AND AS THE FRONT ARRIVES AT PEAK
HEATING...NUMEROUS THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS
THE AREA...SOME WHICH ARE LIKELY TO BE SEVERE. THE FRONT WILL
CONTINUE A VERY SLOW PROGRESSION SOUTH AND EAST ON FRIDAY WITH
LINGERING THREATS FOR STORMS...BEFORE PUSHING OUT OF THE AREA BY
SATURDAY. THIS SHOULD BRING SLIGHTLY COOLER TEMPERATURES AND LESS
HUMIDITY TO THE AREA FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
ASIDE FROM ADJUSTING FOR CURRENT PRECIPITATION...CLOUD...AND
TEMPERATURE TRENDS...THE FORECAST FOR THE OVERNIGHT PERIOD REMAINS
MOSTLY UNCHANGED. SOUTHWESTERLY FLOW IS BEGINNING TO KICK IN
BEHIND THE WARM FRONT...WHICH SHOULD HELP KEEP TEMPS IN THE UPPER
70S TO NEAR 80 IN THE SOUTHWEST PART OF THE CWA. THE AXIS OF
HIGHEST DEWPOINTS IS SLOWLY MOVING NORTHEAST ALONG WITH THE
FRONTAL BOUNDARY.
WITH THE NEAR-SURFACE LAYER BECOMING STABLE...ADDITIONAL
THUNDERSTORM DEVELOPMENT IS NOT EXPECTED. THE SHOWERS AND STORMS
THAT CURRENTLY EXIST WILL SLOWLY WIND DOWN OVER THE NEXT FEW
HOURS...WITH ADDITIONAL PRECIPITATION IN THE NORTHWEST CWA HOLDING
OFF UNTIL MORNING.
PREVIOUS DISCUSSION >
PLAN TO ALLOW EXCESSIVE HEAT WARNING AND HEAT ADVISORIES EXPIRE AS
SCHEDULED AT 8 PM...EXCEPT FOR HAMILTON/MONTGOMERY COUNTIES WHERE
WE WILL CONTINUE WITH HEAT HEADLINES THROUGH THE NIGHT DUE TO
LOCAL EXCESSIVE HEAT WARNING CRITERIA.
STRONG WARM FRONT CURRENTLY DRAPED NW-SE ACROSS INDIANA AND
KENTUCKY TO CONTINUE TO PUSH EAST THIS EVENING AND HAS SUBSTANTIAL
BOUNDARY LAYER MOISTURE POOLED ALONG THIS FEATURE VIA CONVERGENCE.
DEW POINTS IN THE SULTRY MID 70S ALLOWING FOR THE EXCESSIVE HEAT
WARNING THIS EVENING IN THE SOUTHWEST. A BIG AIRMASS CHANGE TO
THAT OVER CNTL OH WHERE DEW POINTS STILL AROUND 60 WITH TEMPS ONLY
IN THE 80S.
CURRENTLY WATCHING DEVELOPING CUMULUS FIELD ALONG/BEHIND THE WARM
FRONT WHERE HRRR RUNS HAVE BEEN CONSISTENT IN ADVERTISING SCT TO
NUMEROUS STORMS BETWEEN 4 PM AND 8 PM ON THE FRONT...AND PUSHING
EAST THROUGH THE WFO ILN FORECAST AREA. IF THIS OCCURS...THERE WILL
BE A SEVERE THREAT GIVEN EXPLOSIVE CAPE IN EXCESS OF 3000 J/KG
ALONG THE FRONT AND MARGINAL SUPERCELLULAR SHEAR AROUND 25-30KTS WHEN
CONSIDERING DEEPER TROPOSPHERIC FLOW ALONG AND ON THE COOL SIDE OF
THE WARM FRONT. HOWEVER...UNDER SHORTWAVE RIDGING AND NO APPARENT S/W
ON WV IMAGERY...VERY LITTLE BACKGROUND/SYNOPTIC FORCING FOR
ASCENT. FEELING IS CURRENTLY THAT WE WILL DEVELOP STORM OR TWO IN
THE MOST CONVERGENT AREAS ALONG THE FRONT AS HEATING PUSHES TEMPS
PAST 100 DEGREES TO OUR WEST AND CAP IS LOCALLY BROKEN. MAY HAVE
AN ISOLD SVR THREAT ON OUR HANDS...BUT THIS IS CONDITIONAL AND
BEST HANDLED BY THE GOING 25-35 PERCENT RAIN CHANCES CURRENTLY IN
THE FORECAST.
WITH CORE OF HIGHEST 925MB/850MB TEMPS COMING ACROSS FORECAST AREA
OVERNIGHT...AND INCREASING SURFACE TO 1KM FLOW...FEEL MOS TEMPS
WAY TOO LOW AND RUNNING ABOVE. WONDERING IF SOME AREAS /CVG/ MAY
STRUGGLE TO DIP BELOW 80 GIVEN THE INCREASING MIXING AND WARM
ADVECTION THROUGH THE NIGHT. THE THREAT FOR AN ELEVATED STORM
WILL PROBABLY CONTINUE ALL NIGHT IN AN ISOLD FASHION VIA STRONG
LOW LEVEL JET AND WARM ADVECTION. AGAIN...LACK OF CONVERGENCE OR
S/W SHOULD KEEP ANY ACTIVITY RELATIVELY ISOLD.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
ATTENTION ON HEAT AND SEVERE WEATHER THREAT ON THURSDAY AFTERNOON
AND EVENING...WITH HEAT THE LESSER OF THE TWO HAZARDS.
REGARDING HEAT...AS MENTIONED ABOVE...CORE OF VERY WARM AIR ALOFT
/850MB TEMPS TO +23C/ WILL BE PUSHING ACROSS AND THEN EAST OF THE
AREA THROUGH THE MORNING YIELDING +20C/21C IN IT/S WAKE FOR THE
AFTERNOON. GIVEN THE MIXED BOUNDARY LAYER RIGHT OFF THE BAT AT
SUNRISE...TEMPS SHOULD RESPOND VERY QUICKLY TO SUNSHINE AND WARM
QUICKLY INTO THE 90S BY LATE MORNING OR NOON. WHILE DEW POINTS WILL
MIX OUT A LITTLE IN THE AFTERNOON AS THE WARM FRONT/MOISTURE
POOLING PUSHES OUT OF THE AREA...DON/T ANTICIPATE TOO MUCH DROP
OFF DURING THE DAY...AND EXPECT DEW POINTS 68-70 MUCH OF AFTERNOON
DESPITE THE BREEZY CONDITIONS. THIS SHOULD PUSH HEAT INDICES TO
AND ABOVE 100 DEGREES FOR THE AFTERNOON AND THUS HEAT ADVISORY ALL
AREAS...WITH EXCESSIVE HEAT WARNING FOR HAMILTON/MONTGOMERY COUNTIES.
BIG FOCUS THOUGH IS THE SEVERE WEATHER THREAT. THURSDAY AFTN HAS
HAD AN ANALOG SIGNAL /CIPS EXPERIMENTAL WARM SEASON GUIDANCE/ OF A
HIGHER END SEVERE THREAT FOR SEVERAL DAYS AND CONFIDENCE CONTINUES
TO HONE IN THAT A REGIONAL SEVERE WEATHER OUTBREAK IS IN THE CARDS
FOR PORTIONS OF THE OHIO VALLEY INCLUDING THE LOCAL FORECAST AREA.
ATTENTION WILL BE ON THE ANOMALOUS /FOR LATE JULY/ SHORTWAVE
TROUGH CURRENTLY NEAR LAKE WINNIPEG...DIGGING SOUTHEAST TOWARD NRN
MN ON THURSDAY. SYNOPTICALLY...DEEP SYSTEMS MOVING THROUGH NRN MN
IN THE WARM SEASON HAVE HIGH CORRELATION TO SIGNIFICANT WEATHER
EVENTS IN THE OHIO VALLEY...AND THIS SETUP APPEARS TO FIT THAT
PATTERN. AS THIS SYSTEM DIGS INTO NRN MN...LOW/MID LEVEL FLOW WILL
BACK EVER SO SLIGHTLY AND MARKEDLY INCREASE...WITH MAINTENANCE OF
A STRONG SWLY LLJ AS WLY MID LEVEL FLOW /35 TO 40KTS/ OVERSPREADS
THAT LLJ AXIS IN THE AFTN. COLD FRONTAL STRUCTURE WILL GET A
LITTLE BETTER ORGANIZED AND SAG INTO THE GREAT LAKES IN THE AFTN
AS CONVERGENCE SLOWLY INCREASES. GIVEN THE AMPLE HEAT/INSTABILITY
BUILDING IN THE WARM SECTOR OVER THE WFO ILN CWA...THE COMBINATION
OF THE INCREASING CONVERGENCE AND MORE IMPORTANTLY THE ARRIVAL OF
A MORE SUBTLE SHORTWAVE /CURRENTLY OVER KS/ SHOULD PROMOTE THE
DEVELOPMENT OF NUMEROUS STORM CLUSTERS WHICH MAY CONGEAL INTO A
LONG /SPATIALLY/ CONVECTIVE SYSTEM WITH /GIVEN CAPE AND SHEAR
PARAMETER SPACE/ AN ABOVE NORMAL CHANCE TO BE A LONGER
LIVED/HIGHER END SEVERE WEATHER MCS.
CIPS ANALOG GUIDANCE USING TOP 8 SVR ANALOGS TO THURSDAY AFTN VIA THE
SPC PPF SYSTEM IS VERY MUCH DIALED IN ON IND/OH/PA AREA AS TARGET
FOR VERY HIGH PROBABILITIES OF SEVERE WEATHER...AND HAS BEEN FOR
SEVERAL DAYS...THIS IS NOT A ONE-RUN-AND-DONE SIGNAL. NEW SPC SWODY2
MIRRORS THIS THREAT AREA...ALBEIT SHIFTED A TAD SOUTH WHICH FITS
HIGHER RESOLUTION /CONVECTION ALLOWING/ 4KM GUIDANCE. LATEST
27.12Z NCEP ARW-CORE HIRES WINDOW RUN IS ESPECIALLY
MENACING...WITH A NRN LINEAR CONVECTIVE SYSTEM HITTING CNTL OHIO
IN THE AFTN TO BE FOLLOWED AN INTENSE BOW ECHO DURING THE EVENING
HITTING THE REST OF THE FORECAST AREA. A WIDESPREAD AND
SIGNIFICANT SEVERE EVENT...WHICH ALSO MIRRORS NCEP NMM /SPC/ WRF.
ADDING FURTHER CONFIDENCE...IS CALIBRATED SPC SREF SEVERE
PROBABILITIES /NOT BASED ON ANALOGS/ THAT ALSO MIRRORS THE ANALOG
AXIS AND CURRENT SPC FORECASTS. SO CONFIDENCE IS THERE...AND
CONTINUED SEVERE MENTIONS IN FORECAST AND RAMPED UP WORDING IN HWO
FOR IMPACTS OF POTENTIAL WIDESPREAD TREE DAMAGE AND SUBSEQUENT
POWER OUTAGES.
IF THE DUAL-MCS SOLUTION VERIFIES...THREAT FOR LOCALIZED FLOODING
VIA THIS 1-2 PUNCH WILL BE INCREASED.
NOT TO PILE IT ON...BUT THE TORNADO THREAT IS NON-ZERO AS
WELL...AND DESPITE MOSTLY SWLY FLOW IN THE BOUNDARY LAYER...THERE
IS DECENT TURNING IN THE LOWEST 1-2KM...SO THERE/S AN OUTSIDE
THREAT OF A TORNADO OR TWO AS LOW LEVEL SHEAR APPEARS STRONG
ENOUGH...AND WILL BE AUGMENTED IF WED NIGHT MCS ACROSS WISC/MICH
CAN SEND A STRONG ENOUGH OUTFLOW BOUNDARY INTO CNTL OHIO BY MORNING/AFTN.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
FRIDAY FORECAST IS TRICKY AS DISJOINTED FRONTAL ZONE LAYS ACROSS THE
OHIO VALLEY. PRESSURE TROUGH/BAROCLINIC ZONE/MOISTURE GRADIENT ARE
ALL SOMEWHAT DISPLACED...AND WITH POTENTIAL FOR AN UPPER LEVEL
SHORTWAVE TROUGH TO CROSS THE AREA...THERE WILL REMAIN THE RISK FOR
THUNDERSTORM DEVELOPMENT. MODEL QPF FRIDAY MORNING SEEMS TIED TO
WHATEVER DEVELOPS THURSDAY AFTERNOON...SO NOT SURE IF THESE POPS
WILL PLAY OUT AS ADVERTISED ACROSS THE SOUTH. I EVENTUALLY SPREAD
CHANCE POPS BACK ACROSS THE AREA BY AFTERNOON...HIGHEST IN THE EAST
WHERE SIGNALS ARE BETTER. 12Z NAM SEEMS OVERDONE COMPARED TO OTHER
MODELS IN REINTRODUCING A HOT/HUMID SURGE (AND ENSUING INSTBY) AHEAD
OF THE COLD FRONT...SO WENT CLOSER TO A SREF/ECMWF BLEND.
NEVERTHELESS...RESPECTABLE MID LEVEL FLOW COMBINED WITH THE INSTBY
WILL MEAN THAT ANY STORMS THAT DO DEVELOP COULD BECOME SEVERE...WITH
HIGHEST CHANCES IN THE EAST.
FOR SATURDAY THROUGH MONDAY...MODELS AND ENSEMBLES AT LEAST AGREE ON
THE UPPER LEVEL PATTERN...WITH REGION SITUATED ON EASTERN SIDE OF
PLAINS/ROCKIES RIDGE. FOR SATURDAY...ADVANCING COLD FRONT MAY HANG
UP ALONG THE APPALACHIANS...WITH A DISTURBANCE IN THE NORTHWEST FLOW
ALOFT ACTIVATING CONVECTION ALONG IT. THERE ARE AT LEAST SOME
INDICATIONS A SFC WAVE WILL BEND BACK INTO THE UPPER OHIO
VALLEY...SO INCLUDED 20 POPS IN THE EASTERN CWA FOR SATURDAY
AFTERNOON. WITH CAA OVER THE CWA...HIGHS WILL BE AT OR BELOW
SEASONAL NORMALS. SUNDAY IS PROBABLY THE DAY WITH HIGHEST FORECAST
CONFIDENCE AS SFC HIGH PRESSURE BUILDS OVER THE CWA. TEMPERATURES
WILL BE SEASONABLE WITH FAIRLY LOW HUMIDITY.
THE GFS/NCEP MODELS TAKES A MORE AMPLIFIED TURN BEGINNING
MONDAY...WITH 500 MB HEIGHTS AT ILN RESIDING ON THE LOW END OF NAEFS
SPREAD BY MID WEEK. THIS AFFECTS PCPN FORECASTS MORE THAN
TEMPERATURES HOWEVER OVER THE LOCAL AREA (AS 00Z AND 12Z ECMWF HOLD
A STRONGER SFC RIDGE IN PLACE). TOOK AN ENSEMBLE APPROACH WITH THE
FORECAST...WHICH DID NOT SIGNIFICANTLY CHANGE THE GOING FORECAST.
TUESDAY WILL HAVE THE HIGHEST PCPN CHANCES...SUPPORTED BY
ENSEMBLES...AS WELL AS A SFC BDY/UPPER WAVE THAT MAY SAG DOWN INTO
THE AREA. CANNOT TOTALLY RULE OUT PCPN MONDAY/WEDNESDAY BUT LIMITED
TO 20 POPS. TEMPERATURES WILL RISE SOME AS LOW LEVEL FLOW BECOME
MORE SOUTHERLY...BUT AT THIS TIME LOOK TO REMAIN WITHIN 5 DEGREES OF
NORMAL. HUMIDITY WILL ALSO INCREASE SLIGHTLY...HOLDING UP OVERNIGHT
LOWS.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
ISOLATED THUNDERSTORMS WILL CONTINUE TONIGHT...ALTHOUGH THE
PROBABILITY OF A TAF SITE BEING IMPACTED IS SLIM. WILL CARRY A DRY
FORECAST FOR MOST TAF LOCATIONS OVERNIGHT...WITH ANY UPDATES
NEEDING TO BE EVENT-DRIVEN.
AS A COLD FRONT MOVES INTO THE REGION TOMORROW...NUMEROUS SHOWERS
AND THUNDERSTORMS ARE EXPECTED TO DEVELOP AND AFFECT ALL TAF
LOCATIONS. WHILE EXACT TIMING IS UNCERTAIN AS USUAL FOR A FORECAST
18+ HOURS IN ADVANCE...SHRA/VCTS HAS BEEN INCLUDED TO INDICATE THE
MOST LIKELY TIME FOR THUNDERSTORMS TO OCCUR. WITHIN THE
THUNDERSTORMS...STRONG TO SEVERE WIND GUSTS AND IFR CONDITIONS
WILL BE POSSIBLE. OUTSIDE OF THE STORMS...VFR CONDITIONS ARE
EXPECTED TO PREVAIL. HOWEVER...STRONG SOUTHWESTERLY FLOW WILL LEAD
TO WIND GUSTS IN THE 20-30 KNOT RANGE.
AS THE MOVEMENT OF THE FRONT SLOWS...SOME LINGERING SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE GOING INTO TOMORROW EVENING
(ESPECIALLY FOR THE SOUTHERN TAF SITES).
OUTLOOK...THUNDERSTORMS ARE POSSIBLE THURSDAY NIGHT THROUGH FRIDAY
NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...HEAT ADVISORY FROM NOON TO 8 PM EDT THURSDAY FOR OHZ026-034-
035-042>046-051>056-060-062>065-070>074-078>082-088.
EXCESSIVE HEAT WARNING UNTIL 8 PM EDT THURSDAY FOR OHZ061-077.
KY...HEAT ADVISORY FROM NOON TO 8 PM EDT THURSDAY FOR KYZ089>100.
IN...HEAT ADVISORY FROM NOON TO 8 PM EDT THURSDAY FOR INZ050-058-
059-066-073>075-080.
&&
$$
SYNOPSIS...BINAU
NEAR TERM...BINAU/HATZOS
SHORT TERM...BINAU
LONG TERM...SNYDER
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
751 PM EDT WED JUL 25 2012
.SYNOPSIS...
A STRONG WARM FRONT LIFTING THROUGH INDIANA AND KENTUCKY WILL
CONTINUE NORTH AND EASTWARD TONIGHT ALLOWING VERY WARM AIR OVER
THE CENTRAL MISSISSIPPI VALLEY TO SPREAD INTO THE AREA TONIGHT.
THIS WARM FRONT MAY BE ACCOMPANIED BY A FEW THUNDERSTORMS DURING
THE NIGHT AS IT CROSSES THE AREA...BUT THE BIGGER STORY WILL COME
ON THURSDAY WHEN HEAT BUILDS AHEAD OF A COLD FRONT SAGGING INTO
THE GREAT LAKES. HEAT INDICES IN EXCESS OF 100 DEGREES ARE LIKELY
FOR MUCH OF THE AREA...AND AS THE FRONT ARRIVES AT PEAK
HEATING...NUMEROUS THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS
THE AREA...SOME WHICH ARE LIKELY TO BE SEVERE. THE FRONT WILL
CONTINUE A VERY SLOW PROGRESSION SOUTH AND EAST ON FRIDAY WITH
LINGERING THREATS FOR STORMS...BEFORE PUSHING OUT OF THE AREA BY
SATURDAY. THIS SHOULD BRING SLIGHTLY COOLER TEMPERATURES AND LESS
HUMIDITY TO THE AREA FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
PLAN TO ALLOW EXCESSIVE HEAT WARNING AND HEAT ADVISORIES EXPIRE AS
SCHEDULED AT 8 PM...EXCEPT FOR HAMILTON/MONTGOMERY COUNTIES WHERE
WE WILL CONTINUE WITH HEAT HEADLINES THROUGH THE NIGHT DUE TO
LOCAL EXCESSIVE HEAT WARNING CRITERIA.
STRONG WARM FRONT CURRENTLY DRAPED NW-SE ACROSS INDIANA AND
KENTUCKY TO CONTINUE TO PUSH EAST THIS EVENING AND HAS SUBSTANTIAL
BOUNDARY LAYER MOISTURE POOLED ALONG THIS FEATURE VIA CONVERGENCE.
DEW POINTS IN THE SULTRY MID 70S ALLOWING FOR THE EXCESSIVE HEAT
WARNING THIS EVENING IN THE SOUTHWEST. A BIG AIRMASS CHANGE TO
THAT OVER CNTL OH WHERE DEW POINTS STILL AROUND 60 WITH TEMPS ONLY
IN THE 80S.
CURRENTLY WATCHING DEVELOPING CUMULUS FIELD ALONG/BEHIND THE WARM
FRONT WHERE HRRR RUNS HAVE BEEN CONSISTENT IN ADVERTISING SCT TO
NUMEROUS STORMS BETWEEN 4 PM AND 8 PM ON THE FRONT...AND PUSHING
EAST THROUGH THE WFO ILN FORECAST AREA. IF THIS OCCURS...THERE WILL
BE A SEVERE THREAT GIVEN EXPLOSIVE CAPE IN EXCESS OF 3000 J/KG
ALONG THE FRONT AND MARGINAL SUPERCELLULAR SHEAR AROUND 25-30KTS WHEN
CONSIDERING DEEPER TROPOSPHERIC FLOW ALONG AND ON THE COOL SIDE OF
THE WARM FRONT. HOWEVER...UNDER SHORTWAVE RIDGING AND NO APPARENT S/W
ON WV IMAGERY...VERY LITTLE BACKGROUND/SYNOPTIC FORCING FOR
ASCENT. FEELING IS CURRENTLY THAT WE WILL DEVELOP STORM OR TWO IN
THE MOST CONVERGENT AREAS ALONG THE FRONT AS HEATING PUSHES TEMPS
PAST 100 DEGREES TO OUR WEST AND CAP IS LOCALLY BROKEN. MAY HAVE
AN ISOLD SVR THREAT ON OUR HANDS...BUT THIS IS CONDITIONAL AND
BEST HANDLED BY THE GOING 25-35 PERCENT RAIN CHANCES CURRENTLY IN
THE FORECAST.
WITH CORE OF HIGHEST 925MB/850MB TEMPS COMING ACROSS FORECAST AREA
OVERNIGHT...AND INCREASING SURFACE TO 1KM FLOW...FEEL MOS TEMPS
WAY TOO LOW AND RUNNING ABOVE. WONDERING IF SOME AREAS /CVG/ MAY
STRUGGLE TO DIP BELOW 80 GIVEN THE INCREASING MIXING AND WARM
ADVECTION THROUGH THE NIGHT. THE THREAT FOR AN ELEVATED STORM
WILL PROBABLY CONTINUE ALL NIGHT IN AN ISOLD FASHION VIA STRONG
LOW LEVEL JET AND WARM ADVECTION. AGAIN...LACK OF CONVERGENCE OR
S/W SHOULD KEEP ANY ACTIVITY RELATIVELY ISOLD.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
ATTENTION ON HEAT AND SEVERE WEATHER THREAT ON THURSDAY AFTERNOON
AND EVENING...WITH HEAT THE LESSER OF THE TWO HAZARDS.
REGARDING HEAT...AS MENTIONED ABOVE...CORE OF VERY WARM AIR ALOFT
/850MB TEMPS TO +23C/ WILL BE PUSHING ACROSS AND THEN EAST OF THE
AREA THROUGH THE MORNING YIELDING +20C/21C IN IT/S WAKE FOR THE
AFTERNOON. GIVEN THE MIXED BOUNDARY LAYER RIGHT OFF THE BAT AT
SUNRISE...TEMPS SHOULD RESPOND VERY QUICKLY TO SUNSHINE AND WARM
QUICKLY INTO THE 90S BY LATE MORNING OR NOON. WHILE DEW POINTS WILL
MIX OUT A LITTLE IN THE AFTERNOON AS THE WARM FRONT/MOISTURE
POOLING PUSHES OUT OF THE AREA...DON/T ANTICIPATE TOO MUCH DROP
OFF DURING THE DAY...AND EXPECT DEW POINTS 68-70 MUCH OF AFTERNOON
DESPITE THE BREEZY CONDITIONS. THIS SHOULD PUSH HEAT INDICES TO
AND ABOVE 100 DEGREES FOR THE AFTERNOON AND THUS HEAT ADVISORY ALL
AREAS...WITH EXCESSIVE HEAT WARNING FOR HAMILTON/MONTGOMERY COUNTIES.
BIG FOCUS THOUGH IS THE SEVERE WEATHER THREAT. THURSDAY AFTN HAS
HAD AN ANALOG SIGNAL /CIPS EXPERIMENTAL WARM SEASON GUIDANCE/ OF A
HIGHER END SEVERE THREAT FOR SEVERAL DAYS AND CONFIDENCE CONTINUES
TO HONE IN THAT A REGIONAL SEVERE WEATHER OUTBREAK IS IN THE CARDS
FOR PORTIONS OF THE OHIO VALLEY INCLUDING THE LOCAL FORECAST AREA.
ATTENTION WILL BE ON THE ANOMALOUS /FOR LATE JULY/ SHORTWAVE
TROUGH CURRENTLY NEAR LAKE WINNIPEG...DIGGING SOUTHEAST TOWARD NRN
MN ON THURSDAY. SYNOPTICALLY...DEEP SYSTEMS MOVING THROUGH NRN MN
IN THE WARM SEASON HAVE HIGH CORRELATION TO SIGNIFICANT WEATHER
EVENTS IN THE OHIO VALLEY...AND THIS SETUP APPEARS TO FIT THAT
PATTERN. AS THIS SYSTEM DIGS INTO NRN MN...LOW/MID LEVEL FLOW WILL
BACK EVER SO SLIGHTLY AND MARKEDLY INCREASE...WITH MAINTENANCE OF
A STRONG SWLY LLJ AS WLY MID LEVEL FLOW /35 TO 40KTS/ OVERSPREADS
THAT LLJ AXIS IN THE AFTN. COLD FRONTAL STRUCTURE WILL GET A
LITTLE BETTER ORGANIZED AND SAG INTO THE GREAT LAKES IN THE AFTN
AS CONVERGENCE SLOWLY INCREASES. GIVEN THE AMPLE HEAT/INSTABILITY
BUILDING IN THE WARM SECTOR OVER THE WFO ILN CWA...THE COMBINATION
OF THE INCREASING CONVERGENCE AND MORE IMPORTANTLY THE ARRIVAL OF
A MORE SUBTLE SHORTWAVE /CURRENTLY OVER KS/ SHOULD PROMOTE THE
DEVELOPMENT OF NUMEROUS STORM CLUSTERS WHICH MAY CONGEAL INTO A
LONG /SPATIALLY/ CONVECTIVE SYSTEM WITH /GIVEN CAPE AND SHEAR
PARAMETER SPACE/ AN ABOVE NORMAL CHANCE TO BE A LONGER
LIVED/HIGHER END SEVERE WEATHER MCS.
CIPS ANALOG GUIDANCE USING TOP 8 SVR ANALOGS TO THURSDAY AFTN VIA THE
SPC PPF SYSTEM IS VERY MUCH DIALED IN ON IND/OH/PA AREA AS TARGET
FOR VERY HIGH PROBABILITIES OF SEVERE WEATHER...AND HAS BEEN FOR
SEVERAL DAYS...THIS IS NOT A ONE-RUN-AND-DONE SIGNAL. NEW SPC SWODY2
MIRRORS THIS THREAT AREA...ALBEIT SHIFTED A TAD SOUTH WHICH FITS
HIGHER RESOLUTION /CONVECTION ALLOWING/ 4KM GUIDANCE. LATEST
27.12Z NCEP ARW-CORE HIRES WINDOW RUN IS ESPECIALLY
MENACING...WITH A NRN LINEAR CONVECTIVE SYSTEM HITTING CNTL OHIO
IN THE AFTN TO BE FOLLOWED AN INTENSE BOW ECHO DURING THE EVENING
HITTING THE REST OF THE FORECAST AREA. A WIDESPREAD AND
SIGNIFICANT SEVERE EVENT...WHICH ALSO MIRRORS NCEP NMM /SPC/ WRF.
ADDING FURTHER CONFIDENCE...IS CALIBRATED SPC SREF SEVERE
PROBABILITIES /NOT BASED ON ANALOGS/ THAT ALSO MIRRORS THE ANALOG
AXIS AND CURRENT SPC FORECASTS. SO CONFIDENCE IS THERE...AND
CONTINUED SEVERE MENTIONS IN FORECAST AND RAMPED UP WORDING IN HWO
FOR IMPACTS OF POTENTIAL WIDESPREAD TREE DAMAGE AND SUBSEQUENT
POWER OUTAGES.
IF THE DUAL-MCS SOLUTION VERIFIES...THREAT FOR LOCALIZED FLOODING
VIA THIS 1-2 PUNCH WILL BE INCREASED.
NOT TO PILE IT ON...BUT THE TORNADO THREAT IS NON-ZERO AS
WELL...AND DESPITE MOSTLY SWLY FLOW IN THE BOUNDARY LAYER...THERE
IS DECENT TURNING IN THE LOWEST 1-2KM...SO THERE/S AN OUTSIDE
THREAT OF A TORNADO OR TWO AS LOW LEVEL SHEAR APPEARS STRONG
ENOUGH...AND WILL BE AUGMENTED IF WED NIGHT MCS ACROSS WISC/MICH
CAN SEND A STRONG ENOUGH OUTFLOW BOUNDARY INTO CNTL OHIO BY MORNING/AFTN.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
FRIDAY FORECAST IS TRICKY AS DISJOINTED FRONTAL ZONE LAYS ACROSS THE
OHIO VALLEY. PRESSURE TROUGH/BAROCLINIC ZONE/MOISTURE GRADIENT ARE
ALL SOMEWHAT DISPLACED...AND WITH POTENTIAL FOR AN UPPER LEVEL
SHORTWAVE TROUGH TO CROSS THE AREA...THERE WILL REMAIN THE RISK FOR
THUNDERSTORM DEVELOPMENT. MODEL QPF FRIDAY MORNING SEEMS TIED TO
WHATEVER DEVELOPS THURSDAY AFTERNOON...SO NOT SURE IF THESE POPS
WILL PLAY OUT AS ADVERTISED ACROSS THE SOUTH. I EVENTUALLY SPREAD
CHANCE POPS BACK ACROSS THE AREA BY AFTERNOON...HIGHEST IN THE EAST
WHERE SIGNALS ARE BETTER. 12Z NAM SEEMS OVERDONE COMPARED TO OTHER
MODELS IN REINTRODUCING A HOT/HUMID SURGE (AND ENSUING INSTBY) AHEAD
OF THE COLD FRONT...SO WENT CLOSER TO A SREF/ECMWF BLEND.
NEVERTHELESS...RESPECTABLE MID LEVEL FLOW COMBINED WITH THE INSTBY
WILL MEAN THAT ANY STORMS THAT DO DEVELOP COULD BECOME SEVERE...WITH
HIGHEST CHANCES IN THE EAST.
FOR SATURDAY THROUGH MONDAY...MODELS AND ENSEMBLES AT LEAST AGREE ON
THE UPPER LEVEL PATTERN...WITH REGION SITUATED ON EASTERN SIDE OF
PLAINS/ROCKIES RIDGE. FOR SATURDAY...ADVANCING COLD FRONT MAY HANG
UP ALONG THE APPALACHIANS...WITH A DISTURBANCE IN THE NORTHWEST FLOW
ALOFT ACTIVATING CONVECTION ALONG IT. THERE ARE AT LEAST SOME
INDICATIONS A SFC WAVE WILL BEND BACK INTO THE UPPER OHIO
VALLEY...SO INCLUDED 20 POPS IN THE EASTERN CWA FOR SATURDAY
AFTERNOON. WITH CAA OVER THE CWA...HIGHS WILL BE AT OR BELOW
SEASONAL NORMALS. SUNDAY IS PROBABLY THE DAY WITH HIGHEST FORECAST
CONFIDENCE AS SFC HIGH PRESSURE BUILDS OVER THE CWA. TEMPERATURES
WILL BE SEASONABLE WITH FAIRLY LOW HUMIDITY.
THE GFS/NCEP MODELS TAKES A MORE AMPLIFIED TURN BEGINNING
MONDAY...WITH 500 MB HEIGHTS AT ILN RESIDING ON THE LOW END OF NAEFS
SPREAD BY MID WEEK. THIS AFFECTS PCPN FORECASTS MORE THAN
TEMPERATURES HOWEVER OVER THE LOCAL AREA (AS 00Z AND 12Z ECMWF HOLD
A STRONGER SFC RIDGE IN PLACE). TOOK AN ENSEMBLE APPROACH WITH THE
FORECAST...WHICH DID NOT SIGNIFICANTLY CHANGE THE GOING FORECAST.
TUESDAY WILL HAVE THE HIGHEST PCPN CHANCES...SUPPORTED BY
ENSEMBLES...AS WELL AS A SFC BDY/UPPER WAVE THAT MAY SAG DOWN INTO
THE AREA. CANNOT TOTALLY RULE OUT PCPN MONDAY/WEDNESDAY BUT LIMITED
TO 20 POPS. TEMPERATURES WILL RISE SOME AS LOW LEVEL FLOW BECOME
MORE SOUTHERLY...BUT AT THIS TIME LOOK TO REMAIN WITHIN 5 DEGREES OF
NORMAL. HUMIDITY WILL ALSO INCREASE SLIGHTLY...HOLDING UP OVERNIGHT
LOWS.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
ISOLATED THUNDERSTORMS WILL CONTINUE TONIGHT...ALTHOUGH THE
PROBABILITY OF A TAF SITE BEING IMPACTED IS SLIM. WILL CARRY A DRY
FORECAST FOR MOST TAF LOCATIONS OVERNIGHT...WITH ANY UPDATES
NEEDING TO BE EVENT-DRIVEN.
AS A COLD FRONT MOVES INTO THE REGION TOMORROW...NUMEROUS SHOWERS
AND THUNDERSTORMS ARE EXPECTED TO DEVELOP AND AFFECT ALL TAF
LOCATIONS. WHILE EXACT TIMING IS UNCERTAIN AS USUAL FOR A FORECAST
18+ HOURS IN ADVANCE...SHRA/VCTS HAS BEEN INCLUDED TO INDICATE THE
MOST LIKELY TIME FOR THUNDERSTORMS TO OCCUR. WITHIN THE
THUNDERSTORMS...STRONG TO SEVERE WIND GUSTS AND IFR CONDITIONS
WILL BE POSSIBLE. OUTSIDE OF THE STORMS...VFR CONDITIONS ARE
EXPECTED TO PREVAIL. HOWEVER...STRONG SOUTHWESTERLY FLOW WILL LEAD
TO WIND GUSTS IN THE 20-30 KNOT RANGE.
AS THE MOVEMENT OF THE FRONT SLOWS...SOME LINGERING SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE GOING INTO TOMORROW EVENING
(ESPECIALLY FOR THE SOUTHERN TAF SITES).
OUTLOOK...THUNDERSTORMS ARE POSSIBLE THURSDAY NIGHT THROUGH FRIDAY
NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR OHZ034-042-060-
061-070>072-078>081.
HEAT ADVISORY FROM NOON TO 8 PM EDT THURSDAY FOR OHZ026-034-
035-042>046-051>056-060-062>065-070>074-078>082-088.
EXCESSIVE HEAT WARNING UNTIL 8 PM EDT THURSDAY FOR OHZ061.
EXCESSIVE HEAT WARNING UNTIL 8 PM EDT THURSDAY FOR OHZ077.
KY...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR KYZ097>100.
HEAT ADVISORY FROM NOON TO 8 PM EDT THURSDAY FOR KYZ089>100.
EXCESSIVE HEAT WARNING UNTIL 8 PM EDT THIS EVENING FOR
KYZ089>096.
IN...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR INZ050-058-059.
HEAT ADVISORY FROM NOON TO 8 PM EDT THURSDAY FOR INZ050-058-
059-066-073>075-080.
EXCESSIVE HEAT WARNING UNTIL 8 PM EDT THIS EVENING FOR INZ066-
073>075-080.
&&
$$
SYNOPSIS...BINAU
NEAR TERM...BINAU
SHORT TERM...BINAU
LONG TERM...SNYDER
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
355 PM EDT TUE JUL 24 2012
.SYNOPSIS...
WEAK FRONT SETTLES SOUTH INTO CENTRAL WV AND SOUTHERN OHIO OVERNIGHT
THEN LIFTS BACK NORTH WEDNESDAY AFTERNOON AND EVENING. COLD FRONT
PASSES THURSDAY NIGHT INTO FRIDAY.
&&
.NEAR TERM /UNTIL 3 AM WEDNESDAY MORNING/...
UPDATED FORECAST TO REMOVE THE FLASH FLOOD WATCH AND THE SEVERE
THUNDERSTORM WATCH AS STRONGER STORMS HAVE MOVED EAST AND SOUTH OF
THE AREA. WILL ALSO LOWER POPS CONSIDERABLY NORTH OF THE COMPLEX AND
BETTER TIME THE COMPLEX OUT OF THE AREA.
&&
.SHORT TERM /3 AM WEDNESDAY MORNING THROUGH FRIDAY NIGHT/...
WARM FRONTAL BOUNDARY WILL CONTINUE TO MOVE NORTH THROUGH THE CWA
WEDNESDAY NIGHT...WITH WARM HUMID AIR SURGING BACK NORTH AGAIN AS IT
DOES SO. THURSDAY LOOKS TO BE ANOTHER HOT AND HUMID DAY...WITH
RISING HEIGHTS AHEAD OF APPROACHING UPPER TROUGH AND MAX
TEMPERATURES IN THE LOWER TO MID 90S...AND DEW POINTS PROGGED TO
REMAIN IN THE 70S...MAY NEED TO CONSIDER A HEAT ADVISORY FOR
THURSDAY...PARTICULARLY ACROSS NORTHERN HALF OF CWA. WILL HIGHLIGHT
THIS IN THE HWO FOR NOW.
COLD FRONT WILL APPROACH CWA THURSDAY NIGHT/FRIDAY. OUT AHEAD OF THE
FRONT...PLENTY OF WARM...UNSTABLE AIR...WITH MODELS SUGGESTING CAPE
OF OVER 2000 J/KG...20-30KT 0-6KM SHEAR...AND 30-40 KT LLJ ACROSS
THE CWA. A SLIGHT RISK HAS ALREADY BEEN ISSUED BY SPC FOR THURSDAY
ACROSS NORTHERN ZONES. IN ADDITION...PW VALUES WILL ONCE AGAIN BE
BACK UP TO AROUND 2 INCHES...HOWEVER...WITH THE OVERALL FAST FLOW
ALOFT EXPECTED...THIS SHOULD HELP TO LIMIT ANY MAJOR WATER
ISSUES...ALTHOUGH HEAVY DOWNPOURS ARE ONCE AGAIN EXPECTED.
USED A BLEND OF THE MET/MAV FOR MAX TEMPERATURES IN THE SHORT TERM.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
ISOLD SHOWER/STORM ACTIVITY WILL PERSIST ACROSS THE CWA ON SATURDAY
AS THE REGION REMAINS UNDER THE INFLUENCE OF AN UPPER LEVEL TROUGH.
HOWEVER...HIGH PRESSURE WILL GRADUALLY BEGIN TO BUILD INTO THE
REGION...PUSHING DRIER AIR INTO THE CWA. THIS WILL SET THE STAGE FOR
A BRIEF DRY PERIOD SUNDAY INTO EARLY NEXT WEEK. REMAINDER OF THE
LONG TERM LOOKS UNSETTLED.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
HEAVIEST CONVECTION WILL BE CROSSING THE MOUNTAINOUS COUNTIES 18Z TO
21Z. LINGERING LIGHTER SHOWERS FURTHER WEST AND NORTH. STILL
QUESTIONABLE ON ANY REDEVELOPMENT OF STORMS...SAY OUT TOWARD SOUTHERN
INDIANA FOR LATE THIS AFTERNOON OR EARLY THIS EVENING. RAP SHOWS
ANOTHER VORT MAX AT 500 MB DROPPING THROUGH SE THRU OHIO INTO WV BY
03Z. SO WILL HOLD ONTO SOME CHANCE POPS IN THE SOUTH AND WEST.
SOME 5 MILES IN HAZE MAY LINGER AFTER THE CONVECTION FOR LATE
AFTERNOON THROUGH SUNSET.
HAVE STRATUS AOB 1 THSD FT BKN AND VSBY AOB 3 MILES IN PATCHES OF FOG
FORMING 03Z TO 06Z...MAINLY EKN-CRW-HTS ON SOUTH INTO THE SOUTHERN
WV COAL FIELDS.
HAVE THE CLOUDS LIFTING 12Z TO 15Z...BECOMING MOSTLY 2 TO 4 THSD FT
BKN BY 18Z. DID NOT INCLUDE ANY CONVECTION IN TAFS BEFORE 18Z...BUT
HAVE CHANCE POPS ACROSS TRI STATE INTO SOUTHERN WV. SOME CONVECTION
NEAR WEAK FRONT MAY REACH NORTH CENTRAL WV TOWARD 18Z WED.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...
FORECAST CONFIDENCE: LOW TO MEDIUM.
ALTERNATE SCENARIOS: FOG AND STRATUS DEVELOPMENT OVERNIGHT IS
MAY VARY IN COVERAGE AND INTENSITY..MAINLY FOR THE 06Z TO 12Z
WEDNESDAY PERIOD.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H M M M M M M L
HTS CONSISTENCY M M M M M H H H H M M M
BKW CONSISTENCY H H H H H H H H H M M H
EKN CONSISTENCY M M M M M H H H M M M M
PKB CONSISTENCY H H H M H H H H H M M M
CKB CONSISTENCY H H H H H H M H M M M M
AFTER 18Z WEDNESDAY...
IFR POSSIBLE IN CONVECTION THURSDAY AFTERNOON AND THURSDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JMV/26
NEAR TERM...RPY
SHORT TERM...SL
LONG TERM...SL
AVIATION...
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
241 PM EDT TUE JUL 24 2012
.SYNOPSIS...
WEAK FRONT SETTLES SOUTH INTO CENTRAL WV AND SOUTHERN OHIO OVERNIGHT
THEN LIFTS BACK NORTH WEDNESDAY AFTERNOON AND EVENING. COLD FRONT
PASSES THURSDAY NIGHT INTO FRIDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
COLD FRONT STILL NORTH OF INTERSTATE 70 IN OHIO AT 18Z. NO SIGNS OF
ANY REDEVELOPMENT IN SOUTHERN INDIANA AT 18Z. MEANWHILE COVERAGE
INCREASING IN NORTH CENTRAL WV. A REDEFINING STATEMENT ADDED A
FEW COUNTIES TOWARD EKN INTO WATCH 509 PER COORDINATION WITH SPC.
ALSO STARTED TO DROP COUNTIES FURTHER WEST INCLUDING SOUTHEAST OHIO.
THE HIGHER POPS QUICKLY DROP FROM NW TO SE LATE THIS AFTERNOON. WILL
LEAVE SOME HAZE IN ITS WAKE. NO MAJOR CHANGES IN POP
FIELD...LEAVING SOME 20 TO 30 PERCENT POPS LATE TONIGHT FROM HTS-CRW
AND BKW. SOME LOWER CLOUDS COULD FORM OVERNIGHT FROM EKN DOWN THRU
CRW AND POINTS SOUTH...SO LEFT MINIMUM TEMPERATURE TOWARD THE WARMER
NAM MOS.
WITH THE WEAK SUMMER FRONT STILL IN THE VICINITY...WILL NOT BUY GFS
BONE DRY POPS YET. HAVE SOME CHANCE POPS CREEPING BACK NORTH
WEDNESDAY AFTERNOON.
MAY BE ABLE TO DROP THE FLASH FLOOD WATCH EARLY...BUT NO REASON TO
JUMP ON THAT AT THIS TIME...ESPECIALLY WITH THE NEW CONVECTION
HEADING INTO THE CENTRAL MOUNTAINS.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
WARM FRONTAL BOUNDARY WILL CONTINUE TO MOVE NORTH THROUGH THE CWA
WEDNESDAY NIGHT...WITH WARM HUMID AIR SURGING BACK NORTH AGAIN AS IT
DOES SO. THURSDAY LOOKS TO BE ANOTHER HOT AND HUMID DAY...WITH
RISING HEIGHTS AHEAD OF APPROACHING UPPER TROUGH AND MAX
TEMPERATURES IN THE LOWER TO MID 90S...AND DEW POINTS PROGGED TO
REMAIN IN THE 70S...MAY NEED TO CONSIDER A HEAT ADVISORY FOR
THURSDAY...PARTICULARLY ACROSS NORTHERN HALF OF CWA. WILL HIGHLIGHT
THIS IN THE HWO FOR NOW.
COLD FRONT WILL APPROACH CWA THURSDAY NIGHT/FRIDAY. OUT AHEAD OF THE
FRONT...PLENTY OF WARM...UNSTABLE AIR...WITH MODELS SUGGESTING CAPE
OF OVER 2000 J/KG...20-30KT 0-6KM SHEAR...AND 30-40 KT LLJ ACROSS
THE CWA. A SLIGHT RISK HAS ALREADY BEEN ISSUED BY SPC FOR THURSDAY
ACROSS NORTHERN ZONES. IN ADDITION...PW VALUES WILL ONCE AGAIN BE
BACK UP TO AROUND 2 INCHES...HOWEVER...WITH THE OVERALL FAST FLOW
ALOFT EXPECTED...THIS SHOULD HELP TO LIMIT ANY MAJOR WATER
ISSUES...ALTHOUGH HEAVY DOWNPOURS ARE ONCE AGAIN EXPECTED.
USED A BLEND OF THE MET/MAV FOR MAX TEMPERATURES IN THE SHORT TERM.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
ISOLD SHOWER/STORM ACTIVITY WILL PERSIST ACROSS THE CWA ON SATURDAY
AS THE REGION REMAINS UNDER THE INFLUENCE OF AN UPPER LEVEL TROUGH.
HOWEVER...HIGH PRESSURE WILL GRADUALLY BEGIN TO BUILD INTO THE
REGION...PUSHING DRIER AIR INTO THE CWA. THIS WILL SET THE STAGE FOR
A BRIEF DRY PERIOD SUNDAY INTO EARLY NEXT WEEK. REMAINDER OF THE
LONG TERM LOOKS UNSETTLED.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
HEAVIEST CONVECTION WILL BE CROSSING THE MOUNTAINOUS COUNTIES 18Z TO
21Z. LINGERING LIGHTER SHOWERS FURTHER WEST AND NORTH. STILL
QUESTIONABLE ON ANY REDEVELOPMENT OF STORMS...SAY OUT TOWARD SOUTHERN
INDIANA FOR LATE THIS AFTERNOON OR EARLY THIS EVENING. RAP SHOWS
ANOTHER VORT MAX AT 500 MB DROPPING THROUGH SE THRU OHIO INTO WV BY
03Z. SO WILL HOLD ONTO SOME CHANCE POPS IN THE SOUTH AND WEST.
SOME 5 MILES IN HAZE MAY LINGER AFTER THE CONVECTION FOR LATE
AFTERNOON THROUGH SUNSET.
HAVE STRATUS AOB 1 THSD FT BKN AND VSBY AOB 3 MILES IN PATCHES OF FOG
FORMING 03Z TO 06Z...MAINLY EKN-CRW-HTS ON SOUTH INTO THE SOUTHERN
WV COAL FIELDS.
HAVE THE CLOUDS LIFTING 12Z TO 15Z...BECOMING MOSTLY 2 TO 4 THSD FT
BKN BY 18Z. DID NOT INCLUDE ANY CONVECTION IN TAFS BEFORE 18Z...BUT
HAVE CHANCE POPS ACROSS TRI STATE INTO SOUTHERN WV. SOME CONVECTION
NEAR WEAK FRONT MAY REACH NORTH CENTRAL WV TOWARD 18Z WED.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...
FORECAST CONFIDENCE: LOW TO MEDIUM.
ALTERNATE SCENARIOS: FOG AND STRATUS DEVELOPMENT OVERNIGHT IS
MAY VARY IN COVERAGE AND INTENSITY..MAINLY FOR THE 06Z TO 12Z
WEDNESDAY PERIOD.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H M M M M M M L
HTS CONSISTENCY M M M M M H H H H M M M
BKW CONSISTENCY H H H H H H H H H M M H
EKN CONSISTENCY M M M M M H H H M M M M
PKB CONSISTENCY H H H M H H H H H M M M
CKB CONSISTENCY H H H H H H M H M M M M
AFTER 18Z WEDNESDAY...
IFR POSSIBLE IN CONVECTION THURSDAY AFTERNOON AND THURSDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR WVZ005>008-
013>016-018-024>030-033>040-046-047.
OH...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR OHZ083-086-
087.
KY...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR KYZ101>103-
105.
VA...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR VAZ003-004.
&&
$$
SYNOPSIS...JMV/26
NEAR TERM...KTB
SHORT TERM...SL
LONG TERM...SL
AVIATION...KTB
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
219 PM EDT TUE JUL 24 2012
.SYNOPSIS...
WEAK FRONT SETTLES SOUTH INTO CENTRAL WV AND SOUTHERN OHIO OVERNIGHT
THEN LIFTS BACK NORTH WEDNESDAY AFTERNOON AND EVENING. COLD FRONT
PASSES THURSDAY NIGHT INTO FRIDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
COLD FRONT STILL NORTH OF INTERSTATE 70 IN OHIO AT 18Z. NO SIGNS OF
ANY REDEVELOPMENT IN SOUTHERN INDIANA AT 18Z. MEANWHILE COVERAGE
INCREASING IN NORTH CENTRAL WV. A REDEFINING STATEMENT ADDED A
FEW COUNTIES TOWARD EKN INTO WATCH 509 PER COORDINATION WITH SPC.
ALSO STARTED TO DROP COUNTIES FURTHER WEST INCLUDING SOUTHEAST OHIO.
THE HIGHER POPS QUICKLY DROP FROM NW TO SE LATE THIS AFTERNOON. WILL
LEAVE SOME HAZE IN ITS WAKE. NO MAJOR CHANGES IN POP
FIELD...LEAVING SOME 20 TO 30 PERCENT POPS LATE TONIGHT FROM HTS-CRW
AND BKW. SOME LOWER CLOUDS COULD FORM OVERNIGHT FROM EKN DOWN THRU
CRW AND POINTS SOUTH...SO LEFT MINIMUM TEMPERATURE TOWARD THE WARMER
NAM MOS.
WITH THE WEAK SUMMER FRONT STILL IN THE VICINITY...WILL NOT BUY GFS
BONE DRY POPS YET. HAVE SOME CHANCE POPS CREEPING BACK NORTH
WEDNESDAY AFTERNOON.
MAY BE ABLE TO DROP THE FLASH FLOOD WATCH EARLY...BUT NO REASON TO
JUMP ON THAT AT THIS TIME...ESPECIALLY WITH THE NEW CONVECTION
HEADING INTO THE CENTRAL MOUNTAINS.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
WARM FRONTAL BOUNDARY WILL CONTINUE TO MOVE NORTH THROUGH THE CWA
WEDNESDAY NIGHT...WITH WARM HUMID AIR SURGING BACK NORTH AGAIN AS IT
DOES SO. THURSDAY LOOKS TO BE ANOTHER HOT AND HUMID DAY...WITH
RISING HEIGHTS AHEAD OF APPROACHING UPPER TROUGH AND MAX
TEMPERATURES IN THE LOWER TO MID 90S...AND DEW POINTS PROGGED TO
REMAIN IN THE 70S...MAY NEED TO CONSIDER A HEAT ADVISORY FOR
THURSDAY...PARTICULARLY ACROSS NORTHERN HALF OF CWA. WILL HIGHLIGHT
THIS IN THE HWO FOR NOW.
COLD FRONT WILL APPROACH CWA THURSDAY NIGHT/FRIDAY. OUT AHEAD OF THE
FRONT...PLENTY OF WARM...UNSTABLE AIR...WITH MODELS SUGGESTING CAPE
OF OVER 2000 J/KG...20-30KT 0-6KM SHEAR...AND 30-40 KT LLJ ACROSS
THE CWA. A SLIGHT RISK HAS ALREADY BEEN ISSUED BY SPC FOR THURSDAY
ACROSS NORTHERN ZONES. IN ADDITION...PW VALUES WILL ONCE AGAIN BE
BACK UP TO AROUND 2 INCHES...HOWEVER...WITH THE OVERALL FAST FLOW
ALOFT EXPECTED...THIS SHOULD HELP TO LIMIT ANY MAJOR WATER
ISSUES...ALTHOUGH HEAVY DOWNPOURS ARE ONCE AGAIN EXPECTED.
USED A BLEND OF THE MET/MAV FOR MAX TEMPERATURES IN THE SHORT TERM.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
ISOLD SHOWER/STORM ACTIVITY WILL PERSIST ACROSS THE CWA ON SATURDAY
AS THE REGION REMAINS UNDER THE INFLUENCE OF AN UPPER LEVEL TROUGH.
HOWEVER...HIGH PRESSURE WILL GRADUALLY BEGIN TO BUILD INTO THE
REGION...PUSHING DRIER AIR INTO THE CWA. THIS WILL SET THE STAGE FOR
A BRIEF DRY PERIOD SUNDAY INTO EARLY NEXT WEEK. REMAINDER OF THE
LONG TERM LOOKS UNSETTLED.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
HEAVIEST CONVECTION WILL BE CROSSING THE MOUNTAINOUS COUNTIES 18Z TO
21Z. LINGERING LIGHTER SHOWERS FURTHER WEST AND NORTH. STILL
QUESTIONABLE ON ANY REDEVELOPMENT OF STORMS...SAY OUT TOWARD SOUTHERN
INDIANA FOR LATE THIS AFTERNOON OR EARLY THIS EVENING. RAP SHOWS
ANOTHER VORT MAX AT 500 MB DROPPING THROUGH SE THRU OHIO INTO WV BY
03Z. SO WILL HOLD ONTO SOME CHANCE POPS IN THE SOUTH AND WEST.
SOME 5 MILES IN HAZE MAY LINGER AFTER THE CONVECTION FOR LATE
AFTERNOON THROUGH SUNSET.
HAVE STRATUS AOB 1 THSD FT BKN AND VSBY AOB 3 MILES IN PATCHES OF FOG
FORMING 03Z TO 06Z...MAINLY EKN-CRW-HTS ON SOUTH INTO THE SOUTHERN
WV COAL FIELDS.
HAVE THE CLOUDS LIFTING 12Z TO 15Z...BECOMING MOSTLY 2 TO 4 THSD FT
BKN BY 18Z. DID NOT INCLUDE ANY CONVECTION IN TAFS BEFORE 18Z...BUT
HAVE CHANCE POPS ACROSS TRI STATE INTO SOUTHERN WV. SOME CONVECTION
NEAR WEAK FRONT MAY REACH NORTH CENTRAL WV TOWARD 18Z WED.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...
FORECAST CONFIDENCE: LOW TO MEDIUM.
ALTERNATE SCENARIOS: FOG AND STRATUS DEVELOPMENT OVERNIGHT IS
MAY VARY IN COVERAGE AND INTENSITY..MAINLY FOR THE 06Z TO 12Z
WEDNESDAY PERIOD.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H M M M M M M L
HTS CONSISTENCY M M M M M H H H H M M M
BKW CONSISTENCY H H H H H H H H H M M H
EKN CONSISTENCY M M M M M H H H M M M M
PKB CONSISTENCY H H H M H H H H H M M M
CKB CONSISTENCY H H H H H H M H M M M M
AFTER 18Z WEDNESDAY...
IFR POSSIBLE IN CONVECTION THURSDAY AFTERNOON AND THURSDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR WVZ005>008-
013>016-018-024>030-033>040-046-047.
OH...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR OHZ083-086-
087.
KY...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR KYZ101>103-
105.
VA...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR VAZ003-004.
&&
$$
SYNOPSIS...JMV/26
NEAR TERM...KTB
SHORT TERM...SL
LONG TERM...SL
AVIATION...KTB
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
146 AM EDT TUE JUL 24 2012
.SYNOPSIS...
A COLD FRONT WILL PUSH SOUTH INTO THE OHIO VALLEY ON TUESDAY. THIS
FRONT WILL WEAKEN AND THEN LIFT NORTHWARD AS A WARM FRONT ON
WEDNESDAY. IN THE WEAK WESTERLY FLOW ALOFT...A SURFACE LOW WILL
DEVELOP OVER THE GREAT LAKES AND SLOWLY MOVE EAST...PUSHING A COLD
FRONT THROUGH THE OHIO VALLEY THURSDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
CONDITIONS ARE QUIESCENT ACROSS THE REGION THIS EVENING AND SHOULD
REMAIN THAT WAY INTO THE LATE NIGHT. LARGE AREA OF MID CLOUDS WILL
SPREAD SOUTHEAST ACROSS THE REGION. THESE CLOUDS ALONG WITH SOUTH
SOUTHWEST WINDS STAYING UP WILL RESULT IN RATHER WARM LOWS. HAVE
BUMPED THEM UP SLIGHTLY.
BIG QUESTION IS WHETHER SHOWERS AND THUNDERSTORMS WILL DEVELOP
LATE TONIGHT AND MOVE INTO THE REGION BEFORE DAYBREAK. LOOKS LIKE
THE 00Z NAM IS DELAYING THIS PRECIPITATION UNTIL TUESDAY. BUT
SEVERAL RUNS OF THE HRRR ALONG WITH SEVERAL 18Z SYNOPTIC MODELS
ARE BRINGING STORMS INTO THE WESTERN PART OF THE FORECAST AREA.
HAVE TAILORED FORECAST ALONG THESE LINES AND BROUGHT POPS IN FROM
THE NORTHWEST LATE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
STORM DEVELOPMENT SHOULD CONTINUE SOUTHEAST ACROSS THE FORECAST
AREA THROUGH THE DAY AS A FRONT SAGS INTO THE REGION. AS THE
COLD FRONT SAGS INTO KENTUCKY TUESDAY...THERE IS AN INCREASED
CHANCE FOR RAIN RUNNING NORTHWEST TO SOUTHEAST THROUGH NORTHERN
KENTUCKY OVERNIGHT. THE DAYTIME HOURS WILL SEE A BIT MUCH MIXING
THAT THE CHANCE FOR DEVELOPMENT IS DECREASING ON WEDNESDAY AS THE
FRONT LIFTS NORTHWARD AS A WARM FRONT. IT WILL BE EVEN HARDER IN A
WARM ADVECTION PATTERN TO SPARK STORMS OVERNIGHT WEDNESDAY AS THE
NECESSARY FORCING IS NOWHERE TO BE FOUND OVER THE OHIO VALLEY.
WHILE THE MECHANISMS FOR STORMS OVER THE NEXT FEW DAYS APPEAR
LACKING...THE ENVIRONMENT IS SUPPORTIVE OF THEM AND ANY LINGERING
BOUNDARIES OR ONGOING CONVECTION MAY INSTIGATE DEVELOPMENT AS WELL
SO A DRY FORECAST IS NOT PRUDENT.
HIGH TEMPERATURES WITHIN A FEW DEGREES OF 90...COOLEST IN
NORTHEAST CWA AND LOWS IN THE UPPER 60S TO LOWER 70S SEEM
REASONABLE THROUGH MID WEEK.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
MODELS SHOW DESCENT AGREEMENT WITH THE PATTERN OVER THE REGION AT
THE BEGINNING OF THE PERIOD. IN A NW FLOW FROM RIDGING OVER THE
ROCKIES...THEY PLACE A S/W DROPPING ACROSS THE LAKES. THE GFS HAS
MORE ENERGY WITH AN INITIAL WAVE AND IS THEREFORE STRONGER WITH
ITS SURFACE REFLECTION. THE OTHER EXTENDED MODELS ARE MORE MUTED
WITH THIS LOW...SO WILL LEAN TOWARDS THE CONSENSUS. AT THE SFC ON
THURSDAY THE REGION IS WARM SECTORED...SO CANT RULE OUT SOME POP
UP CONVECTION. PUT THE HIGHEST POPS IN THE N CLOSER TO THE S/W
WITH GRADUALLY DECREASING POPS AS YOU HEAD S.
THE MAIN H5 S/W SWINGS ACROSS THE LAKES THU NGT INTO FRI. THIS
PULLS A CDFNT THROUGH THE REGION. EXPECT CONVECTION ALONG THE
FRONT...BUT SINCE FROPA APPEARS TO BE MAINLY THU NGT...ONLY KEPT
POPS IN THE CHC CATEGORY. THE S/W DOESNT SWING THRU UNTIL
FRIDAY...SO THIS SHOULD STALL THE MOVEMENT OF THE FRONT EWD AND
SHOULD KICKOFF ADDITION CONVECTION ON FRIDAY. WENT WITH THE HIGHER
POPS IN THE E ON FRIDAY.
WEAK HIGH PRESSURE BUILDS IN FOR SATURDAY INTO SUNDAY. LOOKS LIKE A
WRMFNT MIGHT BE PUSHED OUT OF THE PLAINS INTO THE REGION FOR
MONDAY...BRINGING ANOTHER CHANCE OF PCPN.
FOR TEMPERATURES...LOOKS LIKE THURSDAY WITH BE THE HOTTEST DAY WITH
THE REGION WARM SECTORED. USED A BLEND OF ECMWF/HPC GUIDANCE...WHICH
PUTS HIGHS ON THU IN THE LOWER TO MID 90S. TEMPERATURES FALL BACK
INTO THE UPPER 80S FRIDAY DUE TO THE CLOUD COVER AND CONVECTION. THE
WEEKEND TEMPERATURES LOOK TO STAY IN THE MID TO UPPER 80S.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
SHORT WAVE ENERGY DROPPING DOWN ACROSS THE WESTERN GREAT LAKES
WILL WORK ITS WAY INTO OUR AREA THROUGH THE MORNING HOURS.
SCATTERED PCPN ASSOCIATED WITH THIS IS MOVING DOWN ACROSS NORTHERN
ILLINOIS AND INTO NORTHERN INDIANA EARLY THIS MORNING. THE MODELS
ARE HAVING A DIFFICULT TIME THOUGH RESOLVING EXACTLY HOW TO HANDLE
THINGS THROUGH THE DAY TODAY. OVERALL...EXPECT TO SEE PCPN BECOME A
BIT MORE WIDESPREAD AS THE LOW LEVEL JET INCREASES SOMEWHAT THROUGH
THE PRE DAWN HOURS. BASED ON THE CURRENT TRAJECTORY...WOULD EXPECT
BEST CHANCE FOR ANY SHOWERS THIS MORNING TO BE AT THE NORTHERN/WESTERN TAF
SITES (KDAY). WE MAY SEE A WEAKENING TREND THOUGH AS THE PCPN APPROACHES
OUR AREA AS WE WILL BEGIN TO GET INTO A DIURNALLY LESS FAVORABLE
TIME PERIOD. WILL THEREFORE GENERALLY JUST COVER PCPN THREAT WITH
A VCSH IN THE TAFS. PCPN CHANCES FOR LATER THIS AFTERNOON ARE
ALSO A BIT UNCERTAIN. WE SHOULD DESTABILIZE NICELY THROUGH THIS
AFTERNOON...ESPECIALLY ALONG AND SOUTH OF A COLD FRONT SAGGING
DOWN TOWARD CENTRAL OHIO. WOULD EXPECT TO SEE THE BEST CHANCE FOR
ANY DEVELOPMENT THIS AFTERNOON ACROSS OUR SOUTHERN AREAS SO WILL
ONLY INCLUDE A VCTS AT KCVG/KLUK FOR NOW.
OUTLOOK...THUNDERSTORMS POSSIBLE WEDNESDAY AND THEN AGAIN THURSDAY
AFTERNOON INTO FRIDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...FRANKS
NEAR TERM...
SHORT TERM...FRANKS
LONG TERM...SITES
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1020 PM EDT WED JUL 25 2012
.SYNOPSIS...
HIGH PRESSURE OFF THE SE COAST WILL ALLOW A WARM FRONT OVER THE
OHIO VALLEY TO SURGE INTO THE REGION LATER TONIGHT AND THURSDAY.
A SLOW MOVING COLD FRONT WILL SLIDE ACROSS THURSDAY INTO FRIDAY
BRINGING AN ACTIVE PERIOD OF WEATHER THROUGH THE END OF THE WEEK
WITH STRONG TO SEVERE THUNDERSTORMS POSSIBLE.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
HIGH PRESSURE HAS SLIPPED OFF TO OUR SE. A WARM FRONT OVER OHIO
WILL CONTINUE TO MARCH NE THRU THE REGION SETTING THE STAGE FOR
ANOTHER VERY WARM/HUMID DAY THURSDAY.
BIGGEST QUESTION FOR THE VERY NEAR TERM IS IF WE WILL SEE A LINE
OF SEVERE STORMS RACE ACROSS THE FCST AREA AFTER MIDNIGHT.
REGIONAL RADAR MOSAIC SHOWS AN MCS FORMING RAPIDLY OVER MICHIGAN.
HIGH RES HRRR AND COSPA NOW BACK OFF THE IDEA OF A BOW ECHO
LOOKING FEATURE SWEEPING THRU AND BRING MORE DISORGANIZED STORMS
INTO THE FCST AREA LATER AT NIGHT...TWD DAWN. THIS ALSO FITS WITH
THE NEW NAM WHICH SUGGESTS THE BEST CONVECTION STAYS NORTH OF THE
BORDER THRU 12Z FOR THE MOST PART.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
SPC HAS A MDT RISK OF SVR TSRA VERY LATE TONIGHT AND THURSDAY.
CLUSTERS OF DISCRETE...SUPERCELL STRUCTURES OVER THE NW MTNS DURING
THE PREDAWN HOURS THURSDAY...MAY EVOLVE INTO A LARGER MCS/MCC ACROSS
CENTRAL PENN WITH SWATHS OF WIND DAMAGE /AND FREQUENT LIGHTNING/
BEING THE PRIMARY THREAT ACROSS CENTRAL PENN AND THE SUSQ VALLEY
DURING THE MID MORNING HOURS. 09Z SREF AND 12 GEFS BOTH HIGHLIGHT
THE EXTREMELY STRONG FORCING TRIGGERING THIS INITIAL ROUND OF
TSRA...AS A +3-5 ST DEVIATION WESTERLY 850 MB JET PUSHES ACROSS PENN
AND NEW YORK BETWEEN 08Z AND 14Z THURSDAY.
IN ADDITION...THE SREF/S 850 MB MOISTURE FLUX IS SO TO SAY..OFF THE
CHARTS DURING THE AFOREMENTIONED PERIOD OF INTEREST THURSDAY
MORNING...6 OR MORE STANDARD DEVIATIONS ABOVE NORMAL.
A BRIEF...FEW HOUR PERIOD OF MINIMAL CONVECTIVE ACTIVITY MAY OCCUR
BETWEEN 14-17Z AS COMPENSATING SUBSIDENCE OCCURS IN THE WAKE OF THE
MCS...BEFORE AREAS OF POTENTIALLY SEVERE TSRA FIRE DURING THE MID TO
LATE AFTERNOON HOURS.
ANOMALOUSLY HIGH 850 MB TEMPS OF 20-22C WILL COMBINE WITH A GUSTY
WSW SFC WIND AND ABUNDANT LATE MORNING - MID AFTERNOON SUN TO PUSH
TEMPS TO NEAR RECORD HIGHS WITH HEAT INDICES IN THE 90S ACROSS THE
MTNS...TO BETWEEN 100-104F IN THE SOUTHERN VALLEYS AND THROUGHOUT
MUCH OF THE LOWER TO MID SUSQ VALLEY. RECORDS FOR 7/26 ARE 100F IN
MDT...AND 98F IN KIPT.
A HEAT ADVISORY HAS BEEN POSTED FOR 16Z THU-00Z FRIDAY FOR NEARLY
THE SE HALF OF THE CWA.
THE SREF MEAN CAPES FOR THE AFTN RISE INTO THE 2000-2500J/KG RANGE -
ESP OVER THE NRN HALF OF THE AREA. WINDS WILL BE UNIDIRECTIONAL AT
THAT POINT AND 0-6KM BULK SHEAR AROUND 40KTS. THE SFC LOW PASSING
THROUGH NY STATE AND INTO NEW ENGLAND WILL TRY TO PUSH A SLIGHTLY
COOLER AIR MASS IN FROM THE NORTH. THIS WILL CREATE A GREAT FOCUS
FOR CONVECTION AND LITTLE CINH WILL ALLOW FOR SCT/NMRS TSRA IN THE
AFTN AND INTO THE EARLY PART OF THE NIGHT. HOWEVER...LACK OF HEATING
WILL MOST LIKELY DIMINISH/KILL THE DEEP CONVECTION WITH ONLY WEAK
CONVERGENCE PRESENT ALONG THE BOUNDARY...AND POOR INFLUX OF
ADDITIONAL MSTR FROM THE GULF.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
SVR WX THREAT MAY PERSIST INTO THURS NIGHT BEFORE TRENDING WEAKER
TOWARD CLIMATOLOGICAL CONVECTIVE MINIMUM/EARLY FRI MORNING. THE
STRONGEST WLY 850MB WINDS AND LLVL MSTR WILL SHIFT EWD AND EXIT
SERN PA BTWN 12-15Z...ALONG WITH THE LEADING FRONTAL BOUNDARY.
OVERNIGHT MINS SHOULD BE VERY MILD AND LKLY STAY AOA 75F IN THE
HARRISBURG/YORK/LANCASTER METRO AREA.
UPPER TROF AXIS IS EXPECTED TO SHIFT EWD ACRS THE OH VLY INTO THE
CENTRAL APPALACHIANS ON FRIDAY. DESPITE WEAKER INSTABILITY/LOWER
DEWPOINTS...THERE IS A RELATIVELY LOW THREAT FOR SCT STG TO
PERHAPS SVR STORMS TO DEVELOP IN ADVANCE OF THE MID-UPPER TROF.
MODEST DEEP LYR SHEAR SUGGESTS SOME LOOSELY ORGANIZED CLUSTERS MAY
FORM...MAINLY OVR THE SRN 1/2 OF THE AREA WHERE SPC HAS DRAWN IN A
D3 CATEGORICAL SEE TEXT.
THE PERIOD FROM SAT-WED WILL FEATURE A NEARLY STAGNANT LG SCALE
PATTERN OVR THE LOWER 48...WITH TROUGHING OVER THE ERN U.S.
EXTENDING SWD FM HUDSON BAY UPPER LOW. THE MODELS AND ENSEMBLES
SHOW GOOD AGREEMENT ON THIS SYNOPTIC PATTERN. TEMPS SHOULD AVG
NEAR NORMAL INTO THE MIDDLE OF NEXT WEEK.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
WIDESPREAD VFR WILL CONTINUE THROUGH THE FIRST HALF OF THIS
EVENING ACROSS THE WEST...AND INTO THURSDAY MORNING OVER THE SERN
HALF OF PENN.
WINDS WILL REMAIN LIGHT AND VARIABLE THROUGH THIS PERIOD...BUT
WILL PICK UP AS STRONG SOUTH EASTERLY FLOW PICKS UP EARLY TOMORROW
MORNING. A LOW LEVEL JET SHOULD SET UP OVER THE REGION BY 06Z.
THIS WILL ALLOW FOR LLWS OVER MOST OF PA THROUGH 13Z. GUSTY WINDS
SHOULD FILTER TO THE SFC WITH GUSTS UP TO 30MPH POSSIBLE FROM LATE
TOMORROW MORNING THROUGH THE AFTERNOON.
A POSSIBLE MCS COULD BRING EARLY MORNING SHOWERS AND
THUNDERSTORMS...AS IT MAKES IT`S WAY ACROSS SOUTH CENTRAL NY
STATE. SHOWERS ACROSS THE NORTHERN HALF OF PA ARE POSSIBLE BY
09Z...WITH SHOWERS AND TSRA POSSIBLE ALONG THE LOWER SUSQ LATE
MORNING AHEAD OF A WARM FRONT.
THE MAIN STORMS WILL BE ALONG THE COLD FRONT AS IT MAKES ITS WAY
THROUGH THE COMMONWEALTH THURSDAY AFTERNOON AND EVENING. WITH WARM
MOIST AIR...AND STRONG UNIDIRECTIONAL SHEAR...SVR WEATHER IS
POSSIBLE. IFR OR LOWER CONDITIONS WILL BE POSSIBLE AT ALL TAF
SITES THROUGHOUT THE DAY...BEGINNING WITH BFD AROUND 19Z...WITH THE
REST OF CENTRAL PA TAF SITES BETWEEN 21-00Z. THE LOWER SUSQ SITES
COULD SEE THE FRONTAL...WITH SHOWERS AND THUNDERSTORMS BEHIND
IT...BY 02Z.
OUTLOOK...
THU-SUN...SCT TSRA IMPACTS POSSIBLE.
&&
.EQUIPMENT...
STATE COLLEGE RADAR HAS BEEN RETURNED TO SERVICE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM NOON TO 8 PM EDT THURSDAY FOR PAZ026>028-
034>036-049>052-056-057-059-063>066.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...STEINBUGL
LONG TERM...STEINBUGL
AVIATION...LAMBERT/CERU
EQUIPMENT...LA CORTE
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1027 PM EDT WED JUL 25 2012
.SYNOPSIS...
A WEAK UPPER LEVEL RIDGE OF HIGH PRESSURE WILL PERSIST OVER THE
REGION TONIGHT THROUGH THURSDAY BRINGING VERY WARM AND MUGGY
CONDITIONS. A COLD FRONT IS EXPECTED TO MOVE ACROSS THE CAROLINAS
AND NORTHEAST GEORGIA LATE FRIDAY AND INTO SATURDAY. ANOTHER RIDGE
OF HIGH PRESSURE BUILDS BACK IN SUNDAY AND REMAINS THROUGH EARLY
NEXT WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 1025 PM...OTHER THAN A FEW LINGERING SHRA OVER THE FRENCH
BROAD VALLEY...THE RADAR IS CLEAR. CANNOT COMPLETELY RULE OUT
ANOTHER SHOWER OR TWO OVER THE MTNS TONIGHT...BUT SHUD BE PRECIP
FREE AFTER MIDNIGHT. CIRRUS WILL SLOWLY DIMINISH OVERNIGHT AS WELL
WITH PATCHY FOG ON THE INCREASE. MAIN UPDATES WERE FOR CURRENT
CONDITIONS.
AS OF 755 PM...CONVECTION RAPIDLY DIMINISHING ACROSS THE AREA AND
SHUD END WELL BEFORE MIDNIGHT. HOWEVER...AN ISOLATED CELL CANNOT BE
RULED OUT BEFORE THEN. CLOUDS DIMINISH OVERNIGHT WITH PATCHY FOG
DEVELOPING OUTSIDE OF THE MTNS...WITH PATCHY DENSE FOG IN THE MTN
VALLEYS. LOWS STILL EXPECTED TO BE ABOVE NORMAL.
AS OF 430 PM...CONVECTION FINALLY TAKING OFF ACROSS NC WITH SCT
COVERAGE THERE AND ISOLATED OVER THE UPSTATE. EXPECT SCT COVERAGE
ALL AREAS FOR THE REST OF THE AFTERNOON...WITH SLIGHTLY BETTER
COVERAGE OVER THE NC PIEDMONT. STORMS BECOME ISOLATED ACROSS THE
MTNS BY EARLY EVENING...THEN TAPER OFF FROM NORTH TO SOUTH BY
MIDNIGHT. OTHERWISE...MAIN ADJUSTMENTS WERE FOR CURRENT CONDITIONS.
SO FAR THE WORKED-OVER AIRMASS BEHIND THIS MORNING/S MCS HAS NOT
SPAWNED ANY NEW CONVECTION. HOWEVER...THE CU FIELD IS BECOMING
BETTER DEFINED AND RAP SOUNDINGS SHOW VERY HIGH SURFACE-BASED CAPE
VALUES...PARTICULARLY ALONG AND JUST EAST OF THE BLUE RIDGE.
THEREFORE IT SHOULDN/T BE TOO MUCH LONGER BEFORE CONVECTION BEGINS
TO DEVELOP OVER THE HIGH TERRAIN. THE DEEP LAYER SHEAR IS ABOUT 20
KTS FROM THE NORTHEAST...AND ANY CELLS THAT DO DEVELOP SHOULD DRIFT
INTO THE FOOTHILLS AND POSSIBLY THE WESTERN PIEDMONT. THE WRF-ARW
AND 4KM SPC WRF-NMM ARE BOTH ALREADY WAY OVERDONE WITH CONVECTION
OVER THE REGION...THOUGH THEY DO INSIST THAT VIGOROUS DEVELOPMENT
WILL OCCUR.
THE BOTTOM LINE IS THAT I/LL CONTINUE TO CARRY CHANCE POPS THE REST
OF THE AFTN AND EVENING HOURS...WITH THE HIGHEST POPS ACROSS THE
MTNS AND THE LOWEST ACROSS THE PIEDMONT. HOWEVER...WITH SUCH AN
UNSTABLE ATMOSPHERE AND SEVERAL WEAK BNDRY/S OVER THE REGION IT/S
ENTIRELY POSSIBLE THAT SCATTERED STORMS...ONCE THEY FORM...WILL WORK
SOUTHEASTWARD ACROSS MUCH OF THE REGION DURING THE EVENING HOURS. A
FEW SEVERE STORMS ARE A GOOD BET ONCE THEY START TO FIRE.
THE ATMOSPHERE WILL WARM UP CONSIDERABLY TOMORROW AS THE CENTER OF A
HOT DEEP LAYER RIDGE MOVES ACROSS THE REGION. HEAT INDEX VALUES
SHOULD RISE INTO THE HEAT ADVISORY CRITERIA RANGE FOR SEVERAL HOURS
IN THE AFTERNOON ACROSS THE CHARLOTTE METRO AREA...THE SOUTHERN
UPSTATE AND IN ELBERT COUNTY GEORGIA. CLOSER TO THE MOUNTAINS
DEWPOINTS ARE EXPECTED TO MIX OUT ENOUGH IN THE AFTERNOON TO KEEP
THE HEAT INDEX BELOW ADVISORY CRITERIA. WITH WARMING MID LEVEL
TEMPS...VERY LITTLE SHEAR AND DEWPOINTS MIXING OUT DURING THE
AFTN...CONVECTION IS EXPECTED TO BE ISOLATED AND MAINLY CONFINED TO
THE MOUNTAINS.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 230 PM EDT WEDNESDAY...ON FRIDAY...A COLD FRONT WITH ACTIVE
PRE-FRONTAL CONVECTION IS EXPECTED OVER MIDDLE KY/TN DURING THE PRE
DAWN HOURS. THE FRONT AND PRE-FRONTAL TROF WILL APPROACH THE
SOUTHERN APPALACHIAN REGION DURING THE MORNING AS A L/W TROF DEEPENS
OVER THE MID WEST. CONVECTION IS EXPECTED OVER THE MTNS BY MID DAY...PUSHING
EAST OF THE MTNS DURING THE AFTERNOON AND EVENING. THE ENVIRONMENT
AHEAD OF THE CONVECTIVE BAND WILL FEATURE LLVL BULK SHEAR VALUES
APPROACHING 20 KTS WITH CAPE RANGING FROM 1500 TO 2000 J/KG. A FEW
ORGANIZED STORM CLUSTERS MAY DEVELOP ALONG AND AHEAD OF THE
FRONT...POSSIBLY YIELDING DAMAGING WINDS AND HAIL.
THE LATE DAY PASSAGE OF CONVECTION SHOULD ALLOW HIGH TEMPERATURES TO
REACH THE U90S EAST OF THE MTNS. RETURN FLOW AHEAD OF THE FRONT WILL
SUPPORT DEWPOINT VALUES IN THE U60S. THE COMBINATION OF THE HOT
TEMPERATURES AND MODERATE HUMIDITY SHOULD YIELD HEAT INDEX VALUES
ALONG AND EAST OF I-85 TO REACH NEAR 105 DURING THE LATE AFTERNOON.
HEAT ADVISORY CRITERIA MAY BE REACHED EAST OF I-85.
ON SATURDAY...THE CWA SHOULD REMAIN LARGELY IN A POST FRONTAL
ENVIRONMENT...WITH NW LLVL WINDS. DOWNSLOPE FLOW AND LINGERING MILD
THICKNESSES WILL SUPPORT HIGHS IN THE U80S ACROSS THE MTN VALLEYS
AND MID 90S ALONG AND EAST OF I-85. DEWPOINTS MAY ALSO DECREASE A
FEW DEGREES IN THE WAKE OF THE FRONT. FORECAST SOUNDINGS
CONTINUE TO SHOWS CAPE VALUES AROUND 2000 J/KG DURING THE
AFTERNOON. HOWEVER...A SHALLOW LAYER OF CIN MAY EXIST BELOW THE LFC
AND AND AN WEAK INVERSION WITHIN THE MID LEVEL MAY LIMIT DEEP
CONVECTION. GIVEN THE INSTABILITY AND THE PASSAGE OF THE MID LEVEL
TROF I WILL ADVERTISE SCHC POPS DURING THE AFTERNOON. IF CONVECTION
DOES DEVELOP...THETA-E LAPSE RATES IN THE MID 30S COULD SUPPORT A
DAMAGING WET MICROBURST.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 200 PM EDT WEDNESDAY...THE LATEST MODELS CONTINUE TO
INDICATE THAT THE UPPER TROUGH PERSISTS OVER THE EASTERN CONUS AND A
BROAD UPPER LEVEL RIDGE OF HIGH PRESSURE REMAIN IN PLACE OVER THE
GREAT PLAINS THROUGH THE EXTENDED FORECAST PERIOD. AT THE
SURFACE...A FAIRLY STRONG HIGH PRESSURE IS EXPECTED TO BUILD ACROSS
THE REGION FROM THE NORTH BY LATE SATURDAY AND REMAINS THROUGH
SUNDAY FOR MOSTLY DRY WEATHER WITH SEASONABLY WARM TEMPERATURES. AS
THE HIGH MOVES OFF TO THE EAST MONDAY...A SURFACE LOW PRESSURE IS
EXPECTED TO DEVELOP OVER THE CAROLINAS AND LINGERS INTO WEDNESDAY.
THIS WILL RESULT IN UNSETTLED WEATHER PATTERN AND COOLER
TEMPERATURES ACROSS MUCH OF OUR CWA. TEMPERATURES WILL REMAIN
NEAR...OR A COUPLE DEGREES ABOVE NORMAL THROUGH TUESDAY WITH
AFTERNOON HIGHS IN THE LOW 90S OVER THE PIEDMONT. TEMPERATURES WILL
DROP 5-10 DEGREES BY WEDNESDAY WITH HIGHS IN THE MID 80S OVER THE
PIEDMONT AND 70S MTNS.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
AT KCLT...CONVECTION DIED OFF QUICKLY AS IT MOVED SOUTH TOWARD THE
AIRFIELD. NO ADDITIONAL CONVECTION IS EXPECTED NEAR THE SITE THIS
EVENING. ONLY RESTRICTION EXPECTED THIS PERIOD IS A BRIEF MVFR VSBY
AROUND DAYBREAK. OTHERWISE...DIMINISHING CU AND SW WINDS THIS
EVENING. THEN INCREASING SW WIND THRU THE DAY THU WITH FEW HIGH
BASED CU DEVELOPING BY AFTERNOON.
ELSEWHERE...SIMILAR CONDITIONS TO KCLT. LINGERING CONVECTION OVER
THE MTNS WILL DIMINISH THIS EVENING...WITH CHC OF AFFECTING A
TERMINAL VERY LOW. DIMINISHING CU AND WINDS THIS EVENING WITH MVFR
VSBY EXPECTED AT KHKY/KAND. IFR VSBY...AND POSSIBLY CIG...EXPECTED
AT KAVL. FOG SHUD BURN OFF QUICKLY THU MORN...WITH DEVELOPING HIGH
BASED CU BY AFTERNOON. CONVECTION SHUD REMAIN LIMITED TO THE MTNS
DURING THE AFTERNOON AS A STRONG RIDGE BUILDS ACROSS THE REGION.
OUTLOOK...CHANCE FOR CONVECTION WILL INCREASE BY FRIDAY AS A COLD
FRONT MOVES INTO THE AREA. DRIER HIGH PRESSURE BUILDING INTO THE
REGION MAY LIMIT COVERAGE OF CONVECTION BY THE END OF THE WEEKEND.
BEST CHC OF OVERNIGHT RESTRICTIONS THROUGH THE PERIOD WILL BE IN
AREAS THAT SEE LOCALLY HEAVY RAIN.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...HEAT ADVISORY FROM NOON TO 7 PM EDT THURSDAY FOR GAZ029.
NC...HEAT ADVISORY FROM NOON TO 7 PM EDT THURSDAY FOR NCZ071-072-
082.
SC...HEAT ADVISORY FROM NOON TO 7 PM EDT THURSDAY FOR SCZ009-
011>014-019.
&&
$$
SYNOPSIS...JOH
NEAR TERM...MCAVOY/RWH
SHORT TERM...NED
LONG TERM...JOH
AVIATION...RWH
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
759 PM EDT WED JUL 25 2012
.SYNOPSIS...
A WEAK UPPER LEVEL RIDGE OF HIGH PRESSURE WILL PERSIST OVER THE
REGION TONIGHT THROUGH THURSDAY BRINGING VERY WARM AND MUGGY
CONDITIONS. A COLD FRONT IS EXPECTED TO MOVE ACROSS THE CAROLINAS
AND NORTHEAST GEORGIA LATE FRIDAY AND INTO SATURDAY. ANOTHER RIDGE
OF HIGH PRESSURE BUILDS BACK IN SUNDAY AND REMAINS THROUGH EARLY
NEXT WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 755 PM...CONVECTION RAPIDLY DIMINISHING ACROSS THE AREA AND
SHUD END WELL BEFORE MIDNIGHT. HOWEVER...AN ISOLATED CELL CANNOT BE
RULED OUT BEFORE THEN. CLOUDS DIMINISH OVERNIGHT WITH PATCHY FOG
DEVELOPING OUTSIDE OF THE MTNS...WITH PATCHY DENSE FOG IN THE MTN
VALLEYS. LOWS STILL EXPECTED TO BE ABOVE NORMAL.
AS OF 430 PM...CONVECTION FINALLY TAKING OFF ACROSS NC WITH SCT
COVERAGE THERE AND ISOLATED OVER THE UPSTATE. EXPECT SCT COVERAGE
ALL AREAS FOR THE REST OF THE AFTERNOON...WITH SLIGHTLY BETTER
COVERAGE OVER THE NC PIEDMONT. STORMS BECOME ISOLATED ACROSS THE
MTNS BY EARLY EVENING...THEN TAPER OFF FROM NORTH TO SOUTH BY
MIDNIGHT. OTHERWISE...MAIN ADJUSTMENTS WERE FOR CURRENT CONDITIONS.
SO FAR THE WORKED-OVER AIRMASS BEHIND THIS MORNING/S MCS HAS NOT
SPAWNED ANY NEW CONVECTION. HOWEVER...THE CU FIELD IS BECOMING
BETTER DEFINED AND RAP SOUNDINGS SHOW VERY HIGH SURFACE-BASED CAPE
VALUES...PARTICULARLY ALONG AND JUST EAST OF THE BLUE RIDGE.
THEREFORE IT SHOULDN/T BE TOO MUCH LONGER BEFORE CONVECTION BEGINS
TO DEVELOP OVER THE HIGH TERRAIN. THE DEEP LAYER SHEAR IS ABOUT 20
KTS FROM THE NORTHEAST...AND ANY CELLS THAT DO DEVELOP SHOULD DRIFT
INTO THE FOOTHILLS AND POSSIBLY THE WESTERN PIEDMONT. THE WRF-ARW
AND 4KM SPC WRF-NMM ARE BOTH ALREADY WAY OVERDONE WITH CONVECTION
OVER THE REGION...THOUGH THEY DO INSIST THAT VIGOROUS DEVELOPMENT
WILL OCCUR.
THE BOTTOM LINE IS THAT I/LL CONTINUE TO CARRY CHANCE POPS THE REST
OF THE AFTN AND EVENING HOURS...WITH THE HIGHEST POPS ACROSS THE
MTNS AND THE LOWEST ACROSS THE PIEDMONT. HOWEVER...WITH SUCH AN
UNSTABLE ATMOSPHERE AND SEVERAL WEAK BNDRY/S OVER THE REGION IT/S
ENTIRELY POSSIBLE THAT SCATTERED STORMS...ONCE THEY FORM...WILL WORK
SOUTHEASTWARD ACROSS MUCH OF THE REGION DURING THE EVENING HOURS. A
FEW SEVERE STORMS ARE A GOOD BET ONCE THEY START TO FIRE.
THE ATMOSPHERE WILL WARM UP CONSIDERABLY TOMORROW AS THE CENTER OF A
HOT DEEP LAYER RIDGE MOVES ACROSS THE REGION. HEAT INDEX VALUES
SHOULD RISE INTO THE HEAT ADVISORY CRITERIA RANGE FOR SEVERAL HOURS
IN THE AFTERNOON ACROSS THE CHARLOTTE METRO AREA...THE SOUTHERN
UPSTATE AND IN ELBERT COUNTY GEORGIA. CLOSER TO THE MOUNTAINS
DEWPOINTS ARE EXPECTED TO MIX OUT ENOUGH IN THE AFTERNOON TO KEEP
THE HEAT INDEX BELOW ADVISORY CRITERIA. WITH WARMING MID LEVEL
TEMPS...VERY LITTLE SHEAR AND DEWPOINTS MIXING OUT DURING THE
AFTN...CONVECTION IS EXPECTED TO BE ISOLATED AND MAINLY CONFINED TO
THE MOUNTAINS.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 230 PM EDT WEDNESDAY...ON FRIDAY...A COLD FRONT WITH ACTIVE
PRE-FRONTAL CONVECTION IS EXPECTED OVER MIDDLE KY/TN DURING THE PRE
DAWN HOURS. THE FRONT AND PRE-FRONTAL TROF WILL APPROACH THE
SOUTHERN APPALACHIAN REGION DURING THE MORNING AS A L/W TROF DEEPENS
OVER THE MID WEST. CONVECTION IS EXPECTED OVER THE MTNS BY MID DAY...PUSHING
EAST OF THE MTNS DURING THE AFTERNOON AND EVENING. THE ENVIRONMENT
AHEAD OF THE CONVECTIVE BAND WILL FEATURE LLVL BULK SHEAR VALUES
APPROACHING 20 KTS WITH CAPE RANGING FROM 1500 TO 2000 J/KG. A FEW
ORGANIZED STORM CLUSTERS MAY DEVELOP ALONG AND AHEAD OF THE
FRONT...POSSIBLY YIELDING DAMAGING WINDS AND HAIL.
THE LATE DAY PASSAGE OF CONVECTION SHOULD ALLOW HIGH TEMPERATURES TO
REACH THE U90S EAST OF THE MTNS. RETURN FLOW AHEAD OF THE FRONT WILL
SUPPORT DEWPOINT VALUES IN THE U60S. THE COMBINATION OF THE HOT
TEMPERATURES AND MODERATE HUMIDITY SHOULD YIELD HEAT INDEX VALUES
ALONG AND EAST OF I-85 TO REACH NEAR 105 DURING THE LATE AFTERNOON.
HEAT ADVISORY CRITERIA MAY BE REACHED EAST OF I-85.
ON SATURDAY...THE CWA SHOULD REMAIN LARGELY IN A POST FRONTAL
ENVIRONMENT...WITH NW LLVL WINDS. DOWNSLOPE FLOW AND LINGERING MILD
THICKNESSES WILL SUPPORT HIGHS IN THE U80S ACROSS THE MTN VALLEYS
AND MID 90S ALONG AND EAST OF I-85. DEWPOINTS MAY ALSO DECREASE A
FEW DEGREES IN THE WAKE OF THE FRONT. FORECAST SOUNDINGS
CONTINUE TO SHOWS CAPE VALUES AROUND 2000 J/KG DURING THE
AFTERNOON. HOWEVER...A SHALLOW LAYER OF CIN MAY EXIST BELOW THE LFC
AND AND AN WEAK INVERSION WITHIN THE MID LEVEL MAY LIMIT DEEP
CONVECTION. GIVEN THE INSTABILITY AND THE PASSAGE OF THE MID LEVEL
TROF I WILL ADVERTISE SCHC POPS DURING THE AFTERNOON. IF CONVECTION
DOES DEVELOP...THETA-E LAPSE RATES IN THE MID 30S COULD SUPPORT A
DAMAGING WET MICROBURST.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 200 PM EDT WEDNESDAY...THE LATEST MODELS CONTINUE TO
INDICATE THAT THE UPPER TROUGH PERSISTS OVER THE EASTERN CONUS AND A
BROAD UPPER LEVEL RIDGE OF HIGH PRESSURE REMAIN IN PLACE OVER THE
GREAT PLAINS THROUGH THE EXTENDED FORECAST PERIOD. AT THE
SURFACE...A FAIRLY STRONG HIGH PRESSURE IS EXPECTED TO BUILD ACROSS
THE REGION FROM THE NORTH BY LATE SATURDAY AND REMAINS THROUGH
SUNDAY FOR MOSTLY DRY WEATHER WITH SEASONABLY WARM TEMPERATURES. AS
THE HIGH MOVES OFF TO THE EAST MONDAY...A SURFACE LOW PRESSURE IS
EXPECTED TO DEVELOP OVER THE CAROLINAS AND LINGERS INTO WEDNESDAY.
THIS WILL RESULT IN UNSETTLED WEATHER PATTERN AND COOLER
TEMPERATURES ACROSS MUCH OF OUR CWA. TEMPERATURES WILL REMAIN
NEAR...OR A COUPLE DEGREES ABOVE NORMAL THROUGH TUESDAY WITH
AFTERNOON HIGHS IN THE LOW 90S OVER THE PIEDMONT. TEMPERATURES WILL
DROP 5-10 DEGREES BY WEDNESDAY WITH HIGHS IN THE MID 80S OVER THE
PIEDMONT AND 70S MTNS.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AT KCLT...CONVECTION DIED OFF QUICKLY AS IT MOVED SOUTH TOWARD THE
AIRFIELD. NO ADDITIONAL CONVECTION IS EXPECTED NEAR THE SITE THIS
EVENING. ONLY RESTRICTION EXPECTED THIS PERIOD IS A BRIEF MVFR VSBY
AROUND DAYBREAK. OTHERWISE...DIMINISHING CU AND SW WINDS THIS
EVENING. THEN INCREASING SW WIND THRU THE DAY THU WITH FEW HIGH
BASED CU DEVELOPING BY AFTERNOON.
ELSEWHERE...SIMILAR CONDITIONS TO KCLT. LINGERING CONVECTION OVER
THE MTNS WILL DIMINISH THIS EVENING...WITH CHC OF AFFECTING A
TERMINAL VERY LOW. DIMINISHING CU AND WINDS THIS EVENING WITH MVFR
VSBY EXPECTED AT KHKY/KAND. IFR VSBY...AND POSSIBLY CIG...EXPECTED
AT KAVL. FOG SHUD BURN OFF QUICKLY THU MORN...WITH DEVELOPING HIGH
BASED CU BY AFTERNOON. CONVECTION SHUD REMAIN LIMITED TO THE MTNS
DURING THE AFTERNOON AS A STRONG RIDGE BUILDS ACROSS THE REGION.
OUTLOOK...CHANCE FOR CONVECTION WILL INCREASE BY FRIDAY AS A COLD
FRONT MOVES INTO THE AREA. DRIER HIGH PRESSURE BUILDING INTO THE
REGION MAY LIMIT COVERAGE OF CONVECTION BY THE END OF THE WEEKEND.
BEST CHC OF OVERNIGHT RESTRICTIONS THROUGH THE PERIOD WILL BE IN
AREAS THAT SEE LOCALLY HEAVY RAIN.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...HEAT ADVISORY FROM NOON TO 7 PM EDT THURSDAY FOR GAZ029.
NC...HEAT ADVISORY FROM NOON TO 7 PM EDT THURSDAY FOR NCZ071-072-
082.
SC...HEAT ADVISORY FROM NOON TO 7 PM EDT THURSDAY FOR SCZ009-
011>014-019.
&&
$$
SYNOPSIS...JOH
NEAR TERM...MCAVOY/RWH
SHORT TERM...NED
LONG TERM...JOH
AVIATION...RWH
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
251 PM EDT TUE JUL 24 2012
.SYNOPSIS...
A WEAK UPPER LEVEL RIDGE WILL BUILD ACROSS THE REGION TONIGHT AND
PERSIST THROUGH THURSDAY. A COLD FRONT IS THEN EXPECTED TO MOVE
ACROSS THE CAROLINAS AND NORTHEAST GEORGIA ON LATE FRIDAY INTO
SATURDAY. ANOTHER RIDGE OF HIGH PRESSURE BUILDS BACK IN SUN AND
REMAINS THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 250 PM...AN MCS WHICH ORIGINATED OVER THE DAKOTAS LAST NIGHT
HAS CONTINUED TO PROGRESS TO THE SE AND WAS LOCATED OVER ERN KY AND
WRN WV. THE LATEST RAP ANALYSIS SHOWS THAT THE SQUALL LINE IS
EMBEDDED IN AN AREA OF 40-50 KT 0-3KM SHEAR. THIS SHOULD PROVIDE
AMPLE SUPPORT FOR THE MCS TO CONTINUE TO MOVE SE DURING THE REST OF
THE AFTN. THE EASTERN END OF THE LINE IS LOCATED IN AN AREA OF
FAIRLY STABLE AIR AND HAS BEEN DECAYING OF LATE. THE WESTERN
END...HOWEVER...IS IN MUCH MORE UNSTABLE AIR AND CONTINUES TO
EXHIBIT VIGOROUS CONVECTIVE DEVELOPMENT. BASED ON IT/S CURRENT
MOVEMENT...IT SHOULD ENTER THE NC MTNS A LITTLE BEFORE 5 PM. FARTHER
TO THE EAST CONVECTION HAS NOT MAINTAINED AS MUCH ORGANIZATION AS I
EARLIER THROUGH IT WOULD. HOWEVER...VERY INTENSE CELLS HAVE RECENTLY
DEVELOPED JUST EAST OF THE FA IN THE NC PIEDMONT. SPC HAS PLACED
MUCH OF THE NC FOOTHILLS AND PIEDMONT AND THE NE UPSTATE UNDER A
SEVERE TSTM WATCH UNTIL 10 PM AND THERE IS A GOOD CHANCE THAT
DISCRETE SEVERE STORMS WILL BEGIN TO DEVELOP BACK ACROSS OUR
FORECAST AREA OVER THE NEXT HOUR OR TWO. ALL TOLD...LIKELY TO
CATEGORICAL POPS STILL LOOK GOOD THE REST OF THE AFTN AND
EVENING...BUT THE TIMING WAS A LITTLE TOO AGGRESSIVE OVER WESTERN NC.
LATER TONIGHT A WEAK SFC BNDRY WILL MOVE IN FROM THE NORTHEAST. OR
IT MAY SIMPLY BE A MODEL REFLECTION OF EXTENSIVE OUTFLOW BNDRYS.
EITHER WAY...THE NAM KEEPS QUITE A BIT OF CAPE OVER THE REGION
TONIGHT...AND SHRA/TSTMS MAY PERSIST IN SPOTS MUCH OF THE NIGHT. THE
BEST CHANCES WILL PROBABLY BE ALONG THE TN LINE WHERE NW FLOW WILL
GIVE AN OROGRAPHIC BOOST TO CONVECTION. IN THESE AREAS I/VE
MAINTAINED CHANCE POPS THROUGH THE NIGHT...THOUGH ELSEWHERE I TAKE
THEM INTO THE SLIGHT CHANCE RANGE AFTER THE INITIAL ROUNDS OF
CONVECTION.
THE NAM POOLS HIGH DEWPOINTS AND QUITE A BIT OF CAPE OVER THE FA ON
WEDNESDAY. SPC HAS PLACED THE REGION UNDER A 5 PERCENT SEVERE RISK.
THE DEEP LAYER RIDGE WILL TRY TO NOSE BACK INTO THE FA...BUT THE
AMOUNT OF INSTABILITY AND WEAK SFC CONVERGENCE SHOULD SUPPORT GOOD
CONVECTIVE COVERAGE OVER THE WESTERN CAROLINAS AND NE GA DURING THE
AFTN HOURS. SOME OF THESE WILL PROBABLY REACH PULSE SEVERE LIMITS
WITH SMALL AREAS OF WIND DAMAGE AND LARGE HAIL. MAX TEMPS WILL RUN A
COUPLE CATEGORIES ABOVE NORMAL.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AS OF 220 PM EDT TUESDAY...SHORT RANGE MODELS INDICATE THAT THE MID
LEVEL RIDGE WILL BUILD OVER THE REGION ON THURSDAY. H85 TEMPS WITHIN
THE LEE OF THE MOUNTAINS INCREASE TO AROUND 24C DURING THE
AFTERNOON. A WEAK SUBSIDENCE IS EXPECTED TO DEVELOP BETWEEN H7 TO
H8...YIELDING AN SHALLOW LAYER OF CIN BETWEEN 10 TO 30 J/KG. IT
APPEARS THAT WEAK LEE TROF MAY DEEPEN SLIGHTLY WITH WEST H85
FLOW...BUT SFC MOISTURE CONVERGENCE SHOULD REMAIN WEAK. COVERAGE OF
DIURNAL CONVECTION SHOULD BE LIMITED BY AFTERNOON MIXING OF SFC
DEWPOINTS AND PERSISTENT WEAK CAPPING. I WILL FORECAST MID AFTERNOON
INITIATION ACROSS THE RIDGES...WITH CHC POPS INTO THE EARLY EVENING.
COVERAGE EAST OF THE MTNS SHOULD REMAIN LIMITED TO A SCHC. THE MAIN
CONCERN ON THURSDAY WILL BE THE HOT AFTERNOON TEMPERATURES. USING A
BLEND OF MOS...HIGH TEMPERATURES ARE FORECAST TO RANGE FROM AROUND
90 WITHIN THE MTN VALLEYS TO U90S EAST...3 TO 5 DEGREES LOWER THAN
RECORDS. HOWEVER...EVEN WITH MIXING DEWPOINTS...HEAT INDEX VALUES
NEAR THE CLT METRO MAY MEET HEAT ADVISORY CRITERIA.
ON FRIDAY...A WEAK COLD FRONT IS EXPECTED TO MOVE ACROSS THE
SOUTHERN APPALACHIANS DURING THE AFTERNOON. THE ENVIRONMENT AHEAD OF
THE FRONT IS EXPECTED TO DEVELOP CAPE VALUES BETWEEN 1500 TO 2000
J/KG WITH LITTLE TO NO CIN. IN ADDITION...UPPER DIVERGENCE MAY
DEVELOP OVER THE REGION AS THE CORE OF A H3 JET PUSHES ACROSS PA.
GIVEN THE APPROACH OF THE SFC FRONT...WIDESPREAD INSTABILITY...AND
UPPER SUPPORT...I WILL FORECAST LIKELY POPS ACROSS THE MTNS AND 30
TO 40 POPS EAST. SEVERE MULTICELL THUNDERSTORMS MAY DEVELOP ALONG
AND AHEAD OF THE FRONT.
HEAT WILL REMAIN A CONCERN ACROSS THE PIEDMONT AS DEWPOINTS RECOVER
TO THE U60S AND HIGHS ONCE AGAIN REACH INTO THE U90S. HEAT INDEX
VALUES ALONG AND EAST OF I-85 MAY REACH HEAT ADVISORY CRITERIA.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 2 PM EDT TUESDAY...THE LATEST MEDIUM RANGE MODELS CONTINUE TO
INDICATE THAT A COLD FRONT WILL MOVE ACROSS THE AREA ON LATE FRI/SAT
AS AN UPPER TROF DEEPENS OVER THE EAST COAST. THE FRONT IS EXPECTED
TO STALL OVER SOUTH OF THE AREA SUN AND DISSIPATES MON AS A RIDGE
BUILDS IN FROM THE SE. THE STRONGEST UPPER FORCING WILL REMAIN NORTH
OF THE AREA...HOWEVER GOOD OVERALL DYNAMICAL LIFT AND H3 DIV ALONG
WITH PLENTY OF LLVL INSTABILITY WILL BE AVAILABLE FOR SCATTERED
DIURNAL TSTMS EACH DAY THROUGH THE PERIOD. POPS WERE MAINTAINED AT
NEAR CLIMO...HOWEVER IF THIS PATTERN AND S/W TIMING PERSISTS OVER
THE NEXT COUPLE MODEL RUNS...AN INCREASE IN POPS WILL BE WARRANTED
FOR FRI/SAT. SUN LOOKS TO BE THE DRIEST DAY WITH FAIRLY STRONG HIGH
PRESSURE BUILDING IN...YET THE FRONT WILL REMAIN JUST TO THE
SOUTH...SO SLIGHT CHANCE POPS WERE MENTIONED THROUGH THE DAY. MON
WILL BE ACTIVE AGAIN AS ANOTHER SHOT OF UPPER ENERGY ROUNDS THE WRN
RIDGE AND TRAVERSES THE REGION. TEMPERATURES WILL BE NEAR...OR A
COUPLE DEGREES ABOVE NORMAL FRI/SAT. WITH NW/LY FLOW SETTING UP
SUN...EXPECT A COUPLE DEGREES COOLER IN THE MTNS SUN/MON. YET...A
GOOD DOWNSLOPE WARMING COMPONENT WILL ENABLE MAXES RIGHT AROUND
NORMAL OVER THE LOWER PIEDMONT.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
AT KCLT...HAVE HELD ON TO TEMPO GROUP FOR CONVECTION FROM 20-22 UTC
THIS AFTN. TSTMS ARE MOVING INTO THE NC MTNS ATTM. HOWEVER...THEY
HAVE LOST SOME OF THEIR ORGANIZATION. I STILL THINK THEY WILL
ORGANIZE AS THEY EMERGE INTO THE FOOTHILLS AND CONFIDENCE IS STILL
GOOD IN A SQUALL LINE LATER IN THE AFTN. WINDS WILL PROBABLY AVERAGE
FROM THE WNW THE REST OF THE AFTN...THOUGH THEY MAY BACK TO THE WSW
AT TIMES. THEY WILL TURN MORE OUT OF THE NORTH BEHIND A WEAK COLD
FRONT LATE TONIGHT. WHILE NOTHING HAS BEEN CARRIED IN THE
TAF...THERE ARE INDICATIONS THAT SHRA/TSTM ACTIVITY COULD BE IN THE
VCNTY MUCH OF THE NIGHT.
ELSEWHERE...SCT TSTMS WILL CONTINUE TO DEVELOP ACROSS THE REGION
THIS AFTN. A STRONG SQUALL LINE IS EXPECTED TO DROP ACROSS THE
REGION THIS EVENING. FOR NOW I/M JUST GOING TO CARRY VCTS FOR
SEVERAL HOURS...BUT AS THE LINE GETS CLOSER WE SHOULD BE ABLE TO ADD
A PERIOD OF TEMPO OR PREVAILING THUNDER. A WEAK COLD FRONT WILL
STALL OVER THE REGION LATE TONIGHT...AND THIS MAY ALLOW SCT
SHRA/TSTMS TO LAST INTO THE MORNING HOURS...THOUGH FOR NOW THAT
HASN/T BEEN CARRIED IN THE TAF. WINDS WILL BE WSW TO W OVER THE
UPSTATE AND NW OVER WRN NC. WINDS LATER TONIGHT WILL BECOME LIGHT OR
SHIFT TO LIGHT OUT OF THE NORTH BEHIND THE FRONT AND THUNDERSTORM
COMPLEXES.
OUTLOOK...EXPECT SOLID CHC CONVECTION WED AFTERNOON AND EVENING.
BEST CHC OF OVERNIGHT RESTRICTIONS WILL BE IN AREAS THAT SEE LOCALLY
HEAVY RAIN. A COLD FRONT MAY BRING MORE WIDESPREAD CONVECTION FRI
AND FRI NIGHT.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...MCAVOY
SHORT TERM...NED
LONG TERM...JOH
AVIATION...MCAVOY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
157 PM EDT TUE JUL 24 2012
.SYNOPSIS...
A WEAK UPPER LEVEL RIDGE WILL BUILD ACROSS THE REGION TONIGHT AND
PERSIST THROUGH THURSDAY. A COLD FRONT IS THEN EXPECTED TO MOVE
ACROSS THE CAROLINAS AND NORTHEAST GEORGIA ON LATE FRIDAY INTO
SATURDAY. ANOTHER RIDGE OF HIGH PRESSURE BUILDS BACK IN SUN AND
REMAINS THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 155 PM EDT...CONVECTION IS STARTING TO DEVELOP ACROSS THE
MOUNTAINS AND NORTH OF I-40. THIS IS IN LINE WITH THE GRIDS AND ONLY
MINOR TWEAKS HAVE BEEN MADE TO THE FORECAST OVER THE NEXT FEW HOURS.
AS OF 1105 AM EDT...THE ATMOSPHERE IS BECOMING VERY UNSTABLE ALREADY
THIS MORNING AS MOST OF THE FA IS EXPERIENCING FULL SUN. CONVECTION
IS DEVELOPING UPSTREAM OF THE FA OVER ERN KY AND WV. A LONG LIVED
MCS IS MOVING SE AT OVER 50 KTS ACROSS CENTRAL IN AND WRN OH ATTM.
I/M NOT SURE IF THIS FEATURE WILL HOLD TOGETHER AND AFFECT OUR NRN
ZONES STARTING AROUND 20 UTC...OR IF THE LEAD CONVECTION WILL
DEVELOP IT/S OWN COLD POOL AND BECOME AN MCS. HOWEVER...I/M
CONFIDENT THAT ONE OF THESE FEATURES WILL AFFECT THE FA STARTING
BETWEEN ABOUT 2 AND 3 PM. THE WRF-ARW DROPS A WELL FORMED MCS ACROSS
MOST OF THE FORECAST AREA BETWEEN 19-22 UTC. I/VE USED THIS TIMING
TO ADJUST POPS UP INTO THE CATEGORICAL RANGE ALONG THE PROBABLE MCS
PATH LATER IN THE AFTN. THE RAP 0-3 KM BULK SHEAR IS ALSO SUPPORTIVE
OF THIS AS IT INCREASES TO OVER 30 KTS OVER THE NC ZONES AND THE ERN
PART OF THE UPSTATE BY LATE AFTN. I/VE ADDED DAMAGING WIND WORDING
TO THE ZONES IN THESE AREAS AND THE HWO WILL BE PUNCHED UP AS WELL.
ALL OF THIS MATCHES WITH SPC/S 30 PERCENT DAMAGING WIND PROBS FOR
THE FORECAST AREA NORTH AND EAST OF A GREENVILLE TO ASHEVILLE LINE
FOR LATER TODAY.
AS OF 640 AM...NOT MUCH IN THE WAY OF FOG THIS MRNG SO REDUCED
MENTION MOST AREAS. TEMPS WERE TWEAKED WITH LATEST TRENDS...
OTHERWISE FCST IN GOOD SHAPE FOR THIS UPDATE.
STRONGER FLOW ALOFT...INCLUDING A SERIES OF EMBEDDED SHORTWAVES...
COMBINED WITH GOOD INSTABILITY AND STRONG INSOLATION...IS EXPECTED
TO AID THE DEVELOPMENT OF SHWRS AND TSTMS ACROSS THE AREA LATER
TODAY. BETTER SHEAR WILL INCREASE THE CHC OF SEVERE STORMS ACROSS
THE REGION AND SPC HAS PUT THE ENTIRE CWA IN A SLIGHT RISK AREA FOR
SVR STORMS TODAY. THE MAIN CONCERN WILL BE STRAIGHT-LINE WIND DAMAGE
BUT LARGE HAIL AND EVEN AN ISOLD TORNADO WILL ALSO BE PSBL THIS AFTN
AND EVE. COULD ALSO SEE AN MCS DEVELOP UPSTREAM AND DRIFT INTO THE
AREA THIS EVE. ABOVE AVG HIGHS WILL REACH INTO THE MID 90S ACROSS
THE PIEDMONT WITH A FEW UPPER 90S IN THE S ZONES. LOWER MTN VLYS
WILL WARM INTO THE MID-UPPER 80S. CONVECTION SHOULD TAPER OFF LATE
THIS EVE BUT A SLIGHT CHC WILL LINGER OVERNIGHT ACROSS THE MTNS AS
ANOTHER WEAK SHORTWAVE APPROACHES FROM THE NW. LOWS TONIGHT SHOULD
BE A COUPLE DEG ABOVE AVG.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 130 AM EDT TUESDAY...THE SHORT TERM FCST PICKS UP AT 12Z ON
WEDNESDAY WITH AN UPPER RIDGE CENTERED OVER MISSISSIPPI/ALABAMA WITH
NW FLOW ACROSS THE SOUTHERN APPALACHIAN REGION. OVER THE NEXT 24 TO
36 HRS...THE RIDGE FLATTENS A FAIR AMOUNT AS A POTENT LOOKING
SHORTWAVE...THAT IS EMBEDDED WITHIN A BROADER H5 TROF...BEGINS TO DIVE
DOWN FROM THE GREAT LAKES BY THE END OF THE PERIOD AT 12Z ON FRIDAY.
ON WEDNESDAY...A BACKDOOR COLD FRONT WILL MOVE INTO THE CENTRAL
CAROLINAS EARLY IN THE MORNING BRINGING A DECENT SURGE OF LOW TO MID
LVL MOISTURE. FORECAST SOUNDINGS CONTINUE TO DISPLAY 0 TO 6KM BULK
SHEAR VALUES ON THE ORDER OF 20 TO 30KTS OVER THE AREA WITH SFC
BASED CAPE ON THE ORDER OF 500 TO 1000 J/KG. AN MCS COULD DEVELOP TO
OUR NW AND TRACK OVER THE CAROLINAS DURING THE MORNING...WITH
REMNANT CONVECTION MOVING ACROSS THE WESTERN CAROLINAS AND NORTHEAST
GEORGIA DURING THE DAY/EVENING. SOME ORGANIZED CELLS COULD FORM THRU
THE DAY WITH SHEAR VALUES STAYING UP IN THE 20KT RANGE AND HIGH
TEMPS ABOUT A CATEGORY ABOVE NORMAL. THINGS SHOULD EVENTUALLY SETTLE
DOWN OVERNIGHT AS THE LOW LVLS COOL.
ON THURSDAY...BULK SHEAR SHOULD WEAKEN ACROSS THE REGION AS THE
UPPER FLOW BECOMES MORE WESTERLY AND HEIGHTS RISE SLIGHTLY. AT THE
SFC...A LEE TROF WILL LIKELY REMAIN ACROSS THE FCST AREA WITH WEAK
DOWNSLOPE FLOW AND DEEPER MIXING. THIS SHOULD BRING DOWN LOW LVL
DEWPTS MAKING ANY WIDESPREAD TSRA LESS LIKELY. I REDUCED POPS
OVERALL FROM THE PREVIOUS FCST AND ONLY HAVE A SOLID CHANCE OVER THE
HIGHER TERRAIN WITH SLIGHT CHANCE ELSEWHERE. HIGH TEMPERATURES
SHOULD APPROACH 90 DEGREES ACROSS THE MTN VALLEYS WITH MID TO UPPER
90S ACROSS THE LOWER ELEVATIONS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 2 PM EDT TUESDAY...THE LATEST MEDIUM RANGE MODELS CONTINUE TO
INDICATE THAT A COLD FRONT WILL MOVE ACROSS THE AREA ON LATE FRI/SAT
AS AN UPPER TROF DEEPENS OVER THE EAST COAST. THE FRONT IS EXPECTED
TO STALL OVER SOUTH OF THE AREA SUN AND DISSIPATES MON AS A RIDGE
BUILDS IN FROM THE SE. THE STRONGEST UPPER FORCING WILL REMAIN NORTH
OF THE AREA...HOWEVER GOOD OVERALL DYNAMICAL LIFT AND H3 DIV ALONG
WITH PLENTY OF LLVL INSTABILITY WILL BE AVAILABLE FOR SCATTERED
DIURNAL TSTMS EACH DAY THROUGH THE PERIOD. POPS WERE MAINTAINED AT
NEAR CLIMO...HOWEVER IF THIS PATTERN AND S/W TIMING PERSISTS OVER
THE NEXT COUPLE MODEL RUNS...AN INCREASE IN POPS WILL BE WARRANTED
FOR FRI/SAT. SUN LOOKS TO BE THE DRIEST DAY WITH FAIRLY STRONG HIGH
PRESSURE BUILDING IN...YET THE FRONT WILL REMAIN JUST TO THE
SOUTH...SO SLIGHT CHANCE POPS WERE MENTIONED THROUGH THE DAY. MON
WILL BE ACTIVE AGAIN AS ANOTHER SHOT OF UPPER ENERGY ROUNDS THE WRN
RIDGE AND TRAVERSES THE REGION. TEMPERATURES WILL BE NEAR...OR A
COUPLE DEGREES ABOVE NORMAL FRI/SAT. WITH NW/LY FLOW SETTING UP
SUN...EXPECT A COUPLE DEGREES COOLER IN THE MTNS SUN/MON. YET...A
GOOD DOWNSLOPE WARMING COMPONENT WILL ENABLE MAXES RIGHT AROUND
NORMAL OVER THE LOWER PIEDMONT.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AT KCLT...HAVE HELD ON TO TEMPO GROUP FOR CONVECTION FROM 20-22 UTC
THIS AFTN. TSTMS ARE MOVING INTO THE NC MTNS ATTM. HOWEVER...THEY
HAVE LOST SOME OF THEIR ORGANIZATION. I STILL THINK THEY WILL
ORGANIZE AS THEY EMERGE INTO THE FOOTHILLS AND CONFIDENCE IS STILL
GOOD IN A SQUALL LINE LATER IN THE AFTN. WINDS WILL PROBABLY AVERAGE
FROM THE WNW THE REST OF THE AFTN...THOUGH THEY MAY BACK TO THE WSW
AT TIMES. THEY WILL TURN MORE OUT OF THE NORTH BEHIND A WEAK COLD
FRONT LATE TONIGHT. WHILE NOTHING HAS BEEN CARRIED IN THE
TAF...THERE ARE INDICATIONS THAT SHRA/TSTM ACTIVITY COULD BE IN THE
VCNTY MUCH OF THE NIGHT.
ELSEWHERE...SCT TSTMS WILL CONTINUE TO DEVELOP ACROSS THE REGION
THIS AFTN. A STRONG SQUALL LINE IS EXPECTED TO DROP ACROSS THE
REGION THIS EVENING. FOR NOW I/M JUST GOING TO CARRY VCTS FOR
SEVERAL HOURS...BUT AS THE LINE GETS CLOSER WE SHOULD BE ABLE TO ADD
A PERIOD OF TEMPO OR PREVAILING THUNDER. A WEAK COLD FRONT WILL
STALL OVER THE REGION LATE TONIGHT...AND THIS MAY ALLOW SCT
SHRA/TSTMS TO LAST INTO THE MORNING HOURS...THOUGH FOR NOW THAT
HASN/T BEEN CARRIED IN THE TAF. WINDS WILL BE WSW TO W OVER THE
UPSTATE AND NW OVER WRN NC. WINDS LATER TONIGHT WILL BECOME LIGHT OR
SHIFT TO LIGHT OUT OF THE NORTH BEHIND THE FRONT AND THUNDERSTORM
COMPLEXES.
OUTLOOK...EXPECT SOLID CHC CONVECTION WED AFTERNOON AND EVENING.
BEST CHC OF OVERNIGHT RESTRICTIONS WILL BE IN AREAS THAT SEE LOCALLY
HEAVY RAIN. A COLD FRONT MAY BRING MORE WIDESPREAD CONVECTION FRI
AND FRI NIGHT.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...MCAVOY
SHORT TERM...JPT
LONG TERM...JPT
AVIATION...RB
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1109 AM EDT TUE JUL 24 2012
.SYNOPSIS...
A WEAK UPPER LEVEL RIDGE WILL BUILD ACROSS THE REGION AND PERSIST
THROUGH THURSDAY. A COLD FRONT IS THEN EXPECTED TO PUSH INTO THE
CAROLINAS AND NORTHEAST GEORGIA ON FRIDAY AND BECOME STATIONARY OVER
THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1105 AM EDT...THE ATMOSPHERE IS BECOMING VERY UNSTABLE ALREADY
THIS MORNING AS MOST OF THE FA IS EXPERIENCING FULL SUN. CONVECTION
IS DEVELOPING UPSTREAM OF THE FA OVER ERN KY AND WV. A LONG LIVED
MCS IS MOVING SE AT OVER 50 KTS ACROSS CENTRAL IN AND WRN OH ATTM.
I/M NOT SURE IF THIS FEATURE WILL HOLD TOGETHER AND AFFECT OUR NRN
ZONES STARTING AROUND 20 UTC...OR IF THE LEAD CONVECTION WILL
DEVELOP IT/S OWN COLD POOL AND BECOME AN MCS. HOWEVER...I/M
CONFIDENT THAT ONE OF THESE FEATURES WILL AFFECT THE FA STARTING
BETWEEN ABOUT 2 AND 3 PM. THE WRF-ARW DROPS A WELL FORMED MCS ACROSS
MOST OF THE FORECAST AREA BETWEEN 19-22 UTC. I/VE USED THIS TIMING
TO ADJUST POPS UP INTO THE CATEGORICAL RANGE ALONG THE PROBABLE MCS
PATH LATER IN THE AFTN. THE RAP 0-3 KM BULK SHEAR IS ALSO SUPPORTIVE
OF THIS AS IT INCREASES TO OVER 30 KTS OVER THE NC ZONES AND THE ERN
PART OF THE UPSTATE BY LATE AFTN. I/VE ADDED DAMAGING WIND WORDING
TO THE ZONES IN THESE AREAS AND THE HWO WILL BE PUNCHED UP AS WELL.
ALL OF THIS MATCHES WITH SPC/S 30 PERCENT DAMAGING WIND PROBS FOR
THE FORECAST AREA NORTH AND EAST OF A GREENVILLE TO ASHEVILLE LINE
FOR LATER TODAY.
AS OF 640 AM...NOT MUCH IN THE WAY OF FOG THIS MRNG SO REDUCED
MENTION MOST AREAS. TEMPS WERE TWEAKED WITH LATEST TRENDS...
OTHERWISE FCST IN GOOD SHAPE FOR THIS UPDATE.
STRONGER FLOW ALOFT...INCLUDING A SERIES OF EMBEDDED SHORTWAVES...
COMBINED WITH GOOD INSTABILITY AND STRONG INSOLATION...IS EXPECTED
TO AID THE DEVELOPMENT OF SHWRS AND TSTMS ACROSS THE AREA LATER
TODAY. BETTER SHEAR WILL INCREASE THE CHC OF SEVERE STORMS ACROSS
THE REGION AND SPC HAS PUT THE ENTIRE CWA IN A SLIGHT RISK AREA FOR
SVR STORMS TODAY. THE MAIN CONCERN WILL BE STRAIGHT-LINE WIND DAMAGE
BUT LARGE HAIL AND EVEN AN ISOLD TORNADO WILL ALSO BE PSBL THIS AFTN
AND EVE. COULD ALSO SEE AN MCS DEVELOP UPSTREAM AND DRIFT INTO THE
AREA THIS EVE. ABOVE AVG HIGHS WILL REACH INTO THE MID 90S ACROSS
THE PIEDMONT WITH A FEW UPPER 90S IN THE S ZONES. LOWER MTN VLYS
WILL WARM INTO THE MID-UPPER 80S. CONVECTION SHOULD TAPER OFF LATE
THIS EVE BUT A SLIGHT CHC WILL LINGER OVERNIGHT ACROSS THE MTNS AS
ANOTHER WEAK SHORTWAVE APPROACHES FROM THE NW. LOWS TONIGHT SHOULD
BE A COUPLE DEG ABOVE AVG.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 130 AM EDT TUESDAY...THE SHORT TERM FCST PICKS UP AT 12Z ON
WEDNESDAY WITH AN UPPER RIDGE CENTERED OVER MISSISSIPPI/ALABAMA WITH
NW FLOW ACROSS THE SOUTHERN APPALACHIAN REGION. OVER THE NEXT 24 TO
36 HRS...THE RIDGE FLATTENS A FAIR AMOUNT AS A POTENT LOOKING
SHORTWAVE...THAT IS EMBEDDED WITHIN A BROADER H5 TROF...BEGINS TO DIVE
DOWN FROM THE GREAT LAKES BY THE END OF THE PERIOD AT 12Z ON FRIDAY.
ON WEDNESDAY...A BACKDOOR COLD FRONT WILL MOVE INTO THE CENTRAL
CAROLINAS EARLY IN THE MORNING BRINGING A DECENT SURGE OF LOW TO MID
LVL MOISTURE. FORECAST SOUNDINGS CONTINUE TO DISPLAY 0 TO 6KM BULK
SHEAR VALUES ON THE ORDER OF 20 TO 30KTS OVER THE AREA WITH SFC
BASED CAPE ON THE ORDER OF 500 TO 1000 J/KG. AN MCS COULD DEVELOP TO
OUR NW AND TRACK OVER THE CAROLINAS DURING THE MORNING...WITH
REMNANT CONVECTION MOVING ACROSS THE WESTERN CAROLINAS AND NORTHEAST
GEORGIA DURING THE DAY/EVENING. SOME ORGANIZED CELLS COULD FORM THRU
THE DAY WITH SHEAR VALUES STAYING UP IN THE 20KT RANGE AND HIGH
TEMPS ABOUT A CATEGORY ABOVE NORMAL. THINGS SHOULD EVENTUALLY SETTLE
DOWN OVERNIGHT AS THE LOW LVLS COOL.
ON THURSDAY...BULK SHEAR SHOULD WEAKEN ACROSS THE REGION AS THE
UPPER FLOW BECOMES MORE WESTERLY AND HEIGHTS RISE SLIGHTLY. AT THE
SFC...A LEE TROF WILL LIKELY REMAIN ACROSS THE FCST AREA WITH WEAK
DOWNSLOPE FLOW AND DEEPER MIXING. THIS SHOULD BRING DOWN LOW LVL
DEWPTS MAKING ANY WIDESPREAD TSRA LESS LIKELY. I REDUCED POPS
OVERALL FROM THE PREVIOUS FCST AND ONLY HAVE A SOLID CHANCE OVER THE
HIGHER TERRAIN WITH SLIGHT CHANCE ELSEWHERE. HIGH TEMPERATURES
SHOULD APPROACH 90 DEGREES ACROSS THE MTN VALLEYS WITH MID TO UPPER
90S ACROSS THE LOWER ELEVATIONS.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 2 AM EDT...NO SIGNIFICANT CHANGES WERE MADE TO THE MEDIUM
RANGE FCST. STILL ANTICIPATING ANOTHER COLD FRONTAL PASSAGE ON
FRIDAY WITH SFC RIDGING MOVING IN BEHIND THE FRONT AND LINGERING
INTO NEXT WEEK.
PREVIOUS DISCUSSION...
AS OF 100 PM EDT MONDAY...THE LATEST OP MODELS AND GFS ENSEMBLE
MEMBERS ARE IN GOOD AGREEMENT FRI THROUGH THE WEEKEND WITH A OMEGA
BLOCK SETTING UP ACROSS THE NRN ATL OCEAN. THIS WILL INDUCE AND
DEEPEN ANOTHER EAST COAST TROF AND ALLOW A COLD FRONT INTO THE
AREA BY SAT. THE FRONT IS EXPECTED TO STALL ACROSS THE CWFA SAT
THROUGH SUN AND PERHAPS LIFT A LITTLE NORTH ON MON. THE STRONGEST
UPPER FORCING WILL REMAIN NORTH OF THE AREA...HOWEVER GOOD OVERALL
DYNAMICAL LIFT AND H3 DIV ALONG WITH PLENTY OF LLVL INSTABILITY WILL
BE AVAILABLE FOR STRONG TO SEVERE DIURNAL TSTMS EACH DAY EXPECT
PERHAPS SUN. NOCTURNAL ACTIVITY IS ALSO PROBABLE FRI/SAT NIGHT WITH
THE FROPA LATE FRI AND A REINFORCING S/W PUSHING IN LATE SAT. POPS
WERE MAINTAINED AT NEAR CLIMO...HOWEVER IF THIS PATTERN AND S/W
TIMING PERSISTS OVER THE NEXT COUPLE MODEL RUNS...AN INCREASE IN
POPS WILL BE WARRANTED FOR FRI/SAT. SUN LOOKS TO BE THE DRIEST DAY
WITH FAIRLY STRONG HIGH PRESSURE BUILDING IN...YET THE FRONT WILL BE
SHUNTED JUST TO THE SOUTH...SO SLIGHT CHANCE POPS WERE CARRIED
THROUGH THE DAY. MON WILL BE ACTIVE AGAIN AS ANOTHER SHOT OF UPPER
ENERGY ROUNDS THE WRN RIDGE AND TRAVERSES THE REGION. MAX AND MIN
TEMPS WILL BE RIGHT AROUND OR PERHAPS A COUPLE DEGREES ABOVE NORMAL
FRI/SAT. WITH NW/LY FLOW SETTING UP SUN...EXPECT A COUPLE DEGREES
COOLER IN THE MTNS SUN AND PERHAPS EVEN MON. YET...A GOOD DOWNSLOPE
WARMING COMPONENT WILL ENABLE MAXES RIGHT AROUND NORMAL OVER THE
NON/MTNS BOTH SUN AND MON.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
AT KCLT AND ELSEWHERE...ANY PATCHY FOG THAT DEVELOPS SHOULD
DISSIPATE QUICKLY THIS MRNG...THEN CUMULUS WILL INCREASE AND BUILD
IN THE AFTN WITH AT LEAST SCT TSTMS ACROSS THE CWA BY MID-LATE AFTN.
ALL LOCATIONS GET A PROB30 FOR TSTMS TIL 00Z BUT EXPECT ISOLD-SCT
CONVECTION THIS EVE. LGT WINDS EARLY WILL PICK UP WITH MIXING FROM W
TO NW BY AFTN AT 7-10KT.
OUTLOOK...EXPECT SOLID CHC CONVECTION WED AS A COUPLE WEAK
SHORTWAVES MOVE INTO THE AREA FROM THE NW. BEST CHC OF OVERNIGHT
RESTRICTIONS WILL BE IN AREAS THAT SEE LOCALLY HEAVY RAIN. A
STRONGER SHORTWAVE AND ASSOC COLD FRONT MAY BRING MORE WIDESPREAD
CONVECTION THIS WEEKEND.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...MCAVOY
SHORT TERM...JPT
LONG TERM...JPT
AVIATION...RB
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
627 PM CDT WED JUL 25 2012
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...HAVE MAINTAINED VFR CONDITIONS FOR THE NEXT 24 HOURS.
SURFACE WINDS WILL ONCE AGAIN PICK UP DURING THE DAY...ESPECIALLY
AS DAYTIME HEATING KICKS IN...AS WILL THE CLOUD COVER. THE BIG
QUESTION IN THE SHORT TERM REMAINS THE INFLUENCE OF A CONVECTIVE
COMPLEX THAT IS JUST OFFSHORE OF THE MEXICAN COASTLINE BETWEEN
TAMPICO AND BROWNSVILLE. MODELS HINT AT A VORT MAX MOVING NORTH
THURSDAY AND THURSDAY NIGHT...ALLOWING FOR ISOLATED TO SCATTERED
CONVECTION. AT THIS TIME AM NOT CONFIDENT THAT CONVECTION WILL
IMPACT REGIONAL AIRPORTS AND AS SUCH HAVE NOT MENTIONED ANY
CONVECTION IN THE TAF PACKAGE.
&&
.PREV DISCUSSION... /ISSUED 211 PM CDT WED JUL 25 2012/
SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...THE MAIN CONCERN IN
THE SHORT TERM IS THE POTENTIAL INFLUENCE OF THE CONV COMPLEX THAT
HAS BEEN FIRING TODAY JUST OFFSHORE OF THE MEXICAN COASTLINE BETWEEN
BRO AND TAMPICO. BOTH THE RUC AND NAM PICK UP ON A MID LEVEL VORT
LIKELY INDUCED BY THIS CONV AND MOVE IT NORTHWARDS STEADILY THROUGH
THURS AND THURS NIGHT. THE UPPER LEVEL SUPPORT FROM THIS FEATURE
WILL COMBINE WITH THE FAIRLY ELEVATED CAPE VALUES EVIDENT FROM THE
CURRENT LAPS FIELDS AND THE 12Z BRO SOUNDING TO SET THE STAGE FOR
THE FORMATION OF ISOLD TO SCT CONV MAINLY ALONG AND JUST OFFSHORE OF
THE LOWER TX COASTLINE LATER TONIGHT INTO THURSDAY NIGHT.
THE NAM AND RUC GUIDANCE BOTH TRY TO PICK UP ON THE MID LEVEL VORT
LOCATED NEAR THE HEART OF THE CONV AND ADVECT IT STEADILY NORTHWARDS
ALONG OR JUST OFFSHORE OF THE SOUTH TX COASTLINE. THE GFS ALSO PICKS
UP ON THIS FEATURE AND MOVES IT NORTH TOWARDS THE LOWER TX COASTLINE
BUT UNDERPLAYS THE OVERALL DEEPER LAYER MOISTURE POOL OVER THE
REGION. SO GFS HAS LITTLE OR NO POPS FOR THE REGION WHILE THE NAM
BUILDS UP SOME HIGHER POPS NEAR THE LOWER TX COASTLINE. WILL BE
GOING WITH THE NAM GUIDANCE FOR BOTH TEMPS AND POPS SINCE THIS MODEL
APPEARS TO BE INITIALIZING THE BEST ON THIS CONV COMPLEX.
LONG TERM /FRIDAY THROUGH TUESDAY/...
AT THE ONSET OF THE LONG TERM PERIOD UPPER RIDGING BEGINS TO BUILD
OVER THE SOUTHEASTERN ROCKY MOUNTAIN REGION AND SHIFT MORE TOWARDS
THE CENTRAL PLAINS...WHILE AT THE SURFACE RELATIVELY STRONG RIDGING
IS PROGGED TO BE CENTERED OVER THE EAST CENTRAL GULF OF MEXICO AND
THE NORTHERN PLAINS. WEAK LEE TROUGHING IN RESPONSE TO A WEAK
RETREATING UPPER LOW MAY REMAIN PRESENT ENOUGH FRIDAY TO ALLOW FOR
ONE MORE BREEZIER THAN NORMAL DAY BUT THAT SHOULD QUICKLY REMOVE
ITSELF AS A PLAYER FROM OUR WEATHER PATTERN BY SATURDAY.
THE OVERALL THEME OF THE PATTERN WILL CONTINUE TO BE WARM...POSSIBLY
HOT...AND DRY. WINDS SHOULD BE FAIRLY STEADY AND SEASONABLE OUT OF
THE SOUTHEAST AT 10 TO 15 MPH IN THE AFTERNOON. PWAT VALUES REMAIN
FAIRLY LOW AND A SUBSIDENCE INVERSION WILL LIKELY SET UP IN SOME
FORM IN RESPONSE TO THE BUILDING RIDGING OVER NORTHERN TEXAS AND THE
CENTRAL PLAINS. THE BEST WINDOW FOR ANY PRECIP FOR NOW LOOKS TO BE
SUNDAY IN THE AFTERNOON HOURS AS GFS40/ECMWF BOTH SLIDE A LITTLE BIT
OF TROPICAL MOISTURE ASSOCIATED WITH A WEAK WAVE IN VIA A WEAKNESS
IN THE RIDGE TO THE EAST AND OUR NORTH. DID ADD SOME SCHC SHRA/TSRA
TO THIS PERIOD GIVEN THE REASONABLE CONSENSUS ON TIMING FROM EC/GFS.
A PRIMARY CONCERN IN THIS PERIOD MAY BE PROLONGED ABOVE NORMAL
TEMPERATURES. DEEP LAYER AND LOW LEVEL THICKNESSES WILL BE QUITE
HIGH WITH STRONG INSOLATION AMID FEW TO SCATTERED CLOUDS. THE
SURFACE FLOW IS PROJECTED TO BE A LITTLE MORE SOUTHEASTERLY THAN
SOUTHERLY...BUT A FEW VERY HOT DAYS WILL BE POSSIBLE GIVEN THE
STRENGTH OF THE RIDGE. BUMPED UP TEMPERATURES SLIGHTLY FROM THE
GOING FORECAST WHICH CONTINUES TO SIT A LITTLE ABOVE GUIDANCE
CONSENSUS. HEAT INDICIES FROM 105 TO 110 WILL BE VERY MUCH IN PLAY
DURING THE SUNDAY TO WEDNESDAY PERIOD...WITH HEAT ADVISORY CRITERIA
HEAT INDICIES POSSIBLE.
MARINE /TONIGHT THROUGH THURSDAY NIGHT/...CURRENTLY THE PGF ALONG
THE LOWER TX BAY AND GULF WATERS HAS PUSHED CONDITIONS UP INTO SCEC
LEVELS THIS AFTERNOON. EXPECT THIS PGF TO PERSIST THROUGHOUT THE
SHORT TERM PERIOD KEEPING THE BAY AND GULF WATERS CLOSE TO
SCEC/BORDERLINE SCA CRIT THROUGH TOMORROW NIGHT. THE MARINE CONV
PUSHING UP FROM THE SOUTH MAY BRIEFING BOOST THE WINDS AND SEAS UP
CLOSE TO SMW CRIT DUE TO THE CONV OUTFLOW. HOWEVER WILL NOT POST ANY
SCAS AT THIS TIME.
FRIDAY THROUGH SUNDAY....
PERSISTENT MODERATE SOUTHEASTERLY WINDS ARE EXPECTED DURING THE
PERIOD. THE STRONGEST WINDS FOR NOW ARE EXPECTED ON FRIDAY. SCEC
CONDITIONS ON THE LAGUNA IN THE AFTERNOON AND THE EVENING IN THE
OFFSHORE WATERS ARE POSSIBLE DURING THIS TIME. WINDS AND SEAS SHOULD
STAY BELOW SCEC CRITERIA SATURDAY AND SUNDAY WITH SEAS GENERALLY
EXPECTED TO BE BETWEEN THREE AND FIVE FEET.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
58
AREA FORECAST DISCUSSION
NWS SPOKANE WA
512 PM PDT Wed Jul 25 2012
.SYNOPSIS...
Low pressure off and along the coast propped up against higher
pressure in the vicinity of the Northern Rockies will keep a very
minor southwest to northeast oriented storm track in the vicinity
of Eastern Washington and Northern Idaho into next week. This
pattern will should result in near normal temperatures through
much of this and the following workweek.
&&
.DISCUSSION...
Tonight: Slow moving thunderstorms will be our main focus this
evening. With very little wind in the lowest 10 thousand feet of
the model soundings, localized heavy rain will be the main impact
from storms through mid evening. Look for cells to be short lived,
but capable of producing heavy rain rates. This is typically what
we experience in a moderate instability and weak shear
environment.
The 2 PM radar imagery shows scattered showers and thunderstorms
over the high terrain near Mazama, Oroville, Republic and Curlew.
The RUC model suggests that the atmosphere is favorable for
development further south along the Cascade Crest down toward
Stevens and Stampede Pass with CAPE values approaching 1000 J/KG.
Increased convective development can also be expected over the
high terrain around Kettle Falls, Priest Lake and Bonners Ferry
through early evening. By late afternoon and early evening there
may be a better chance of getting some of the cells to survive
as they descend into the low elevations. But the heaviest rains
will likely fall over the mountains where storms are initiated
since they collapse quickly in the weak shear environment.
Overnight, there is a small chance of high based showers, mainly
south of the Spokane forecast area. The GFS and NAM show some
conditional instability mainly above 600mb. With a very dry
air mass from 700mb and below, any showers that develop will
probably not produce much measurable rain. The best elevated
instability on the NAM and GFS prior to sunrise will be over the
Oregon portion of the Columbia Basin. After sunrise the 600-500mb
negative theta-e lapse rates migrate over the Palouse into the
southern and central Idaho Panhandle. Chances for measurable
precipitation is very low, so I limited the precipitation chances
to 15 percent or less. We may need to add sprinkles into the
forecast if we see some high based showers develop on radar late
this evening. /GKoch
Thursday through Saturday...A prolonged period of southwest flow
due to the positioning of a long-wave trof off the coast juxtaposed
against ridge of high pressure with axis remaining somewhere in
Montana influences this time interval. Since the ridge to the east
is not all that well amplified and the southwest flow is not too
southerly in origin forecast temperatures remain very close to
normal. Additionally any mention of precipitation including
thunderstorms possibly fired off by small disturbances passing
through the discussed prevailing southwest to northeast flow remains
low but not zero given the weakness of the depicted disturbances.
There does appear to be enough moisture and energy though via a
ridge in the 700MB equivalent potential temperature fields running
through Eastern Oregon up into North Idaho...which is pretty much
aligned with the described prevailing southwest flow. The best
chance of any convection getting fired off is on Friday as that
wave has the best potential...but the pop still remains low. /Pelatti
Saturday night through Wednesday: Synoptic scale pattern will
remain stagnant as an expansive ridge of high pressure dominates
the central United States. This omega block pattern type will
prevent low pressure over the Gulf of Alaska to shift over the
Pac Northwest. We will remain under dry southwest flow between
this area of lower pressure to our west and higher pressure to our
east. There will be the possibility for some disturbances that
rotate around the Gulf of Alaska low that could impact the region.
However, moisture off the Pacific will be lacking, and without
much of a southerly component in the flow pattern, we will be hard
pressed to draw up any monsoonal moisture as well. Models are
picking up on a weak disturbance that moves through off the
Pacific on Sunday, which may produce some breezy winds. We may see
some more weak disturbances that move across the area next week,
but most of the energy associated with the low in the Gulf of
Alaska looks to stay to our north into British Columbia. Without
any discernible strong frontal systems with big air mass changes,
temperatures will be fairly consistent through the period. Expect
temperatures to be close to seasonal averages under clear or mostly
clear sky conditions. /SVH
&&
.AVIATION...
00Z TAFS: Surface based convection across the northern mountains
will dissipate with sunset this evening as well as the shallow
cumulus over the basin. A very weak wave will cross through the
region out of northeast Oregon Thursday morning into the afternoon
(after 15Z). Mid and upper levels are expected to destabilize across
eastern WA and into the Idaho Panhandle as this wave moves south to
north across the region. This may lead to some elevated convection
and isolated thunderstorms, but confidence is low at this time due
to only weak forcing. We may only get some ACCAS with some light
rain or sprinkles. At this point, placed the best chance, albeit low
chances, at the KLWS and KPUW taf sites between 17Z-21Z. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 63 89 62 87 59 84 / 0 10 10 20 20 0
Coeur d`Alene 57 88 58 87 56 84 / 0 0 10 20 20 0
Pullman 52 88 56 87 53 83 / 10 10 10 20 20 0
Lewiston 64 95 66 94 63 91 / 10 10 10 20 20 0
Colville 56 91 58 90 56 87 / 10 10 10 20 20 10
Sandpoint 53 86 53 85 52 81 / 10 10 10 20 20 0
Kellogg 54 88 58 86 55 81 / 0 10 10 20 20 10
Moses Lake 61 93 62 92 58 88 / 10 0 0 0 10 0
Wenatchee 66 93 66 90 63 87 / 0 0 0 0 10 0
Omak 64 92 60 92 57 88 / 10 10 20 20 20 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
316 PM CDT TUE JUL 24 2012
.SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT
316 PM CDT TUE JUL 24 2012
FORECAST CONCERNS THIS PACKAGE...SHRA/TSRA CHANCES TONIGHT INTO FRI
NIGHT...SEVERE THREAT WED AFTERNOON/EVENING...DANGEROUS HEAT INDICES
WED AFTERNOON/EARLY WED EVENING.
DATA ANALYSIS AT 18Z HAD THE ORIGINAL FRONTAL BOUNDARY ACROSS
CENTRAL IL TO SOUTHERN IA WITH EAST TO SOUTHEAST FLOW NORTH OF IT.
SECONDARY BOUNDARY WAS LOCATED CENTRAL MN TO EAST CENTRAL WI...
ASSOCIATED WITH LINGERING SHRA/TSRA...CLOUDS AND COOLER TEMPS UNDER
THE CLOUDS. WEAK SHORTWAVE MOVING ACROSS EAST CENTRAL MN PLUS WINDS
BECOMING MORE SOUTHERLY ACROSS SOUTHERN MN ADVECTING THE MOIST/
UNSTABLE AIRMASS NORTHWARD OVER THE COOL DOME CONTINUES TO PRODUCE
SHRA AND OCCASIONAL TSRA FROM NORTH OF KLSE INTO NORTHEAST SD.
24.12Z MODELS INITIALIZED RATHER WELL...BUT FOR THE GFS WITH ITS
ABOUT 5F HIGH BIAS ON SFC DEW POINTS IN THE MOISTURE PLUME ACROSS
MUCH OF THE MID/UPPER MS VALLEY. SOLUTIONS QUITE SIMILAR THRU WED
NIGHT THEN BEGIN TO DIVERGE WITH THE SPEED OF THE SHORTWAVE TROUGH
TO DROP ACROSS THE WESTERN GREAT LAKES THU THRU FRI. DPROG/DT OF
500MB HGTS AT 24.12Z SHOWED MODEL RUNS OF 22.12Z AND 23.12Z
VERIFIED QUITE WELL ACROSS NOAM/EASTERN PAC...OFFERING A TIGHTER
COMPROMISE CONSENSUS OF THEIR EARLIER RUNS. CONSENSUS CONTINUES TO
TIGHTEN FOR TONIGHT THRU THU AS HGTS FALL...A STRONG SHORTWAVE
TROUGH TOPS THE CENTRAL NOAM RIDGE AND DROPS INTO THE WESTERN GREAT
LAKES. CONSISTENCY REMAINS QUITE GOOD THU NIGHT INTO FRI NIGHT AS
THIS TROUGH CROSSES WI THEN LIFTS OUT WITH RISING HGTS INTO THE
WEEKEND. ECMWF AGAIN MAINTAINS THE BETTER RUN-TO-RUN CONSISTENCY
THRU THE PERIOD. CHECK OF OBS VS. MODEL DATA AT 18Z SHOWED MODELS
REASONABLE WITH SFC FEATURES ACROSS THE CENTRAL CONUS. GFS REMAINED
TOO HIGH WITH SFC DEW POINTS OVER THE CORN BELT/MID MS VALLEY...
WHILE ECMWF WAS A BIT ON THE LOW SIDE. PER WV IMAGERY GEM/ECMWF
TENDED TO LOOK A BIT BETTER WITH THE SHORTWAVE DETAILS OVER CENTRAL
NOAM. ALL TENDED TO STRUGGLE A BIT WITH THE CONVECTION THIS MORNING/
EARLY THIS AFTERNOON ACROSS THE REGION. A COMPROMISE/ CONSENSUS
LOOKED BEST WITH THIS. NO CLEAR MODEL FAVORITE BUT WITH ECMWF
OFFERING SOME BETTER CONSISTENCY FAVORED A MODEL/ENSEMBLE BLEND
WEIGHTED TOWARD THE ECMWF. SHORT TERM FCST CONFIDENCE AVERAGE THIS
CYCLE.
IN THE SHORT TERM...WEAK SHORTWAVES RIPPLING SOUTHEAST ACROSS THE
AREA COMBINED WITH WEAK CONVERGENCE/LIFT NEAR THE ENHANCED THERMAL
ZONE LOOK TO CONTINUE PRODUCING SCT SHRA/TSRA ACROSS MAINLY THE
NORTHEAST 2/3 OF THE FCST AREA THIS AFTERNOON INTO THIS EVENING.
GIVEN CLOUD COVER TODAY AND LIMITED WARMING/DESTABILIZATION OVER
MUCH OF THE FCST AREA...SEVERE THREAT LATE THIS AFTERNOON/EVENING
LOOKS LOW BUT CANNOT BE RULED OUT.
AS THE NEXT STRONGER SHORTWAVE MOVES ACROSS THE DAKOTAS INTO MN
TONIGHT...STRONGER OF THE SFC-700MB MOISTURE TRANSPORT/THETA-E
CONVERGENCE/WARM ADVECTION FOCUS INTO WESTERN/NORTH-CENTRAL MN THIS
EVENING. CONSENSUS FOR THIS IS FURTHER NORTH THAN THE EARLIER RUNS
WITH MORE WARMING/CAPPING AT 700MB BUILDING OVER THE FCST AREA THRU
THE NIGHT. HAVE SHIFTED HIGHER SHRA/TSRA CHANCES TONIGHT/WED MORNING
NORTH AND EAST...TOWARD THE STRONGER FORCING AND EDGE OF THE
CAPPING. LOWERED RAIN CHANCES OVER THE SOUTH/WEST PARTS OF THE FCST
AREA INTO THE 15-30 PERCENT RANGE OR REMOVED THEM FOR THESE PERIODS.
A VERY WARM 925-700MB AIRMASS PROGGED TO ADVECT NORTHEAST ACROSS THE
CENTRAL/SOUTHEAST PARTS OF THE FCST AREA WED AS THE NEB/SD SFC-
850MB LOW/TROUGH LIFTS INTO CENTRAL/NORTHERN WI. WITH STRONGER
SOUTHWEST GRADIENT FLOW FOR MIXING ON WED...HIGHS ACROSS THE
SOUTHEAST 2/3 OF THE FCST AREA LOOK HEADED FOR THE 95 TO 103 RANGE.
THIS COMBINED WITH HIGHER HUMIDITY. HAVE ALREADY ISSUED A HEAT
ADVISORY FOR THE SOUTHEAST 1/3 OF THE FCST AREA FOR WED AFTERNOON/
EARLY EVENING AND WILL EXPAND THIS NORTHWARD TO INCLUDE PRESTON AND
WINONA MN EASTWARD TO ADAMS/JUNEAU COUNTIES IN WI. POTENTIAL TO
REACH EXCESSIVE HEAT WARNING CRITERIA OVER THE SOUTHEAST END OF THE
FCST AREA WED AFTERNOON BUT DEW POINTS IN QUESTION. POTENTIAL FOR
DEEP MIXING TO AS HIGH AS 800-750MB IN THE WARM SECTOR...WITH DEW
POINTS MIXING OUT INTO THE LOWER 60S. THESE DEW POINTS WOULD NOT
SUPPORT AN EXCESSIVE HEAT WARNING AND HAVE LEFT HEADLINE AS HEAT
ADVISORY FOR NOW.
NEXT CONCERN IS THE LOW/COLD FRONT TO MOVE SOUTHEAST ACROSS THE
AREA WED AFTERNOON/EVENING AND SEVERE THREAT. AIRMASS WILL BE
CAPPED WITH 700MB TEMPS IN THE +12C TO +13C RANGE. BOUNDARY LAYER
COLD ADVECTION WITH THE FRONT LOOKS TO ADVANCE SOUTHEAST BEFORE THE
850-700MB LEVELS COOL. QUESTION IF THERE WILL BE ENOUGH CONVERGENCE/
LIFT...SOME MDT SFC-850MB FN CONVERGENCE INDICATED...WITH THE
FRONTAL PASSAGE TO OVERCOME THE CAPPING. MODEL SOUNDINGS INDICATE
THE HIGHER CHANCE OF THIS OVER THE SOUTHEAST 1/3 TO HALF OF THE
FCST AREA LATER IN THE AFTERNOON. CAPPING WEAKEST WITH SFC TEMPS
AROUND 100F. LIMITED SHRA/TSRA CHANCES TO 30-50 PERCENT WED
AFTERNOON THEN LIMITED THESE TO MAINLY THE SOUTHEAST END OF THE FCST
AREA WED EVENING. ML CAPE AND INCREASING SHEAR WED AFTERNOON/EARLY
EVENING WOULD SUPPORT SEVERE RISK PER SWODY2. WITH THE DEEP MIXED
LAYER...INVERTED V SOUNDINGS AND BULK OF SHEAR IN THE 0-3KM LAYER...
ANY TSRA LOOK CAPABLE OF STRONG/DAMAGING WINDS.
STRONGER SHORTWAVE/TROUGH THEN DROPS SOUTHEAST ACROSS THE AREA
THU/THU NIGHT WITH STRONG HGT FALLS AND INCREASING PV ADVECTION
ALOFT. WITH A DIURNAL INCREASE OF CAPE AND THE DEEP LAYER CYCLONIC
FLOW/CONVERGENCE...SHRA/TSRA CHANCES IN THE 20-50 PERCENT RANGE...
HIGHEST OVER THE NORTH/EAST END OF THE FCST AREA...LOOK REASONABLE
THU AFTERNOON/EVENING AND BLEND WELL WITH NEIGHBORING GRIDS.
LINGERED A SMALL SHRA/TSRA CHANCE OVER THE NORTHEAST END OF THE FCST
AREA FRI WITH WEAK CAPE...STEEP LOW/MID LEVEL LAPSE RATES AND SOME
CYCLONIC CONVERGENCE. DRIER/COOLER HIGH PRESSURE BEGINS TO BUILD IN
FRI NIGHT.
GENERALLY FAVORED A BLEND OF THE NUMERICAL TEMP GUIDANCE FOR TONIGHT
THRU FRI NIGHT. HOWEVER...WITH STRONGER/DEEP MIXING UNDER THE 850-
700MB THERMAL RIDGE...DID FAVOR WARMER OF GUIDANCE HIGHS WED.
.LONG TERM...SATURDAY THROUGH TUESDAY
316 PM CDT TUE JUL 24 2012
24.00Z/24.12Z MEDIUM RANGE MODEL RUNS IN DECENT AGREEMENT WITH EACH
OTHER AND THEIR PREVIOUS RUNS SAT AS LONGWAVE TROUGHING MOVES INTO
THE EASTERN CONUS AND HGTS GRADUALLY RISE OVER THE UPPER MIDWEST.
CONSISTENCY REMAINS GOOD SUN FOR A WAVE TO TOP THE RIDGE AND MOVE
ACROSS THE REGION. MODELS CONVERGED TOWARD A COMPROMISE OF THEIR
EARLIER RUNS FOR SUNDAY. SOME CONSISTENCY AMONG MODELS FOR ANOTHER
SHORTWAVE TO TOP THE RIDGE AND MOVE ACROSS THE NORTHERN PLAINS/UPPER
MIDWEST MON/TUE. HOWEVER DIFFERENCES ON THE TIMING/STRENGTH DETAILS
INCREASE IN THE MON/TUE TIMEFRAME. LONG-TERM FCST CONFIDENCE ABOVE
AVERAGE SAT/SUN THEN AVERAGE MON/TUE. CANADIAN HIGH PRESSURE SETTLES
SOUTH ACROSS THE AREA SAT...EAST OF THE MID LEVEL RIDGE AXIS. A DRY/
SEASONABLE DAY EXPECTED FOR SAT. FIRST WAVE TOPPING THE RIDGE MOVES
INTO MN/IA/WI FOR SAT NIGHT/SUN. SFC-850MB MOISTURE/MOISTURE
TRANSPORT/WARM ADVECTION AHEAD OF THE SFC-LOW LEVEL TROUGH INCREASE
INTO THE AREA THRU SAT NIGHT/SUN...WITH SHRA/TSRA CHANCES SPREADING
BACK INTO/ACROSS THE AREA. THE SECOND WAVE FOR EARLY NEXT WEEK
KEEPS SOME LOWER LEVEL THERMO-DYNAMIC FORCING/LIFT OVER THE AREA
MON/TUE...ALONG WITH THE LOWERING HGTS AND SOME PV ADVECTION ALOFT.
SHRA/TSRA CHANCES LOOK TO CONTINUE ACROSS THE AREA MON/TUE. FAVORING
A MODEL/ENSEMBLE BLEND AND UNCERTAINTIES WITH CLOUD/SHRA/TSRA
COVERAGE ON DAYS 5-7...MODEL CONSENSUS HIGHS/LOWS FOR SAT THRU TUE
LOOK WELL TRENDED AT THIS TIME.
&&
.AVIATION...THROUGH 18Z WEDNESDAY
1240 PM CDT TUE JUL 24 2012
MONITORING THE MESOSCALE CONVECTIVE VORTEX SPINNING INTO THE
NORTHERN TWIN CITIES AREA...WHICH IS HELPING TO FUEL A LINE OF
THUNDERSTORMS FROM RED WING AND WABASHA BACK TO NEAR MANKATO. THIS
ACTIVITY IS BEING ENHANCED ALONG THE DIFFERENTIAL HEATING BOUNDARY
WHERE THE CLEAR AND MUGGY AIRMASS OVER SOUTHERN MN IS FEEDING INTO
THE COOL AIR ACROSS CENTRAL MN. THE LATEST 15Z HRRR MODEL SEEMS TO
HAVE A GOOD HANDLE ON THIS DEVELOPMENT AND TAKES A CONVECTIVE LINE
DOWN ACROSS THE TAF LOCATIONS BETWEEN 21Z AND 23Z. BEYOND
THAT...IT APPEARS THAT MOST OF THE CONVECTION THREAT WILL SHIFT
NORTH AND EAST OF THE TAF LOCATIONS. PLAYED THE FORECASTS THAT WAY
FOR THE 18Z ISSUANCE.
THERE IS SOME INDICATION VIA MODEL GUIDANCE THAT WE COULD SEE SOME
LIGHT FOG DEVELOP LATE TONIGHT DUE TO THE ADDITION OF THE BOUNDARY
LAYER MOISTURE VIA RAINFALL. HOWEVER...WITH SOUTHERLY WINDS ON THE
INCREASE...FEEL THE LOWER ATMOSPHERE WILL BE TOO MIXED TO ALLOW
FOR LIGHT FOG/MIST DEVELOPMENT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
316 PM CDT TUE JUL 24 2012
WI...HEAT ADVISORY FROM NOON TO 9 PM CDT WEDNESDAY FOR WIZ054-055-
061.
HEAT ADVISORY FROM NOON TO 7 PM CDT WEDNESDAY FOR WIZ041>044-
053.
MN...HEAT ADVISORY FROM NOON TO 7 PM CDT WEDNESDAY FOR MNZ088-095-
096.
IA...HEAT ADVISORY FROM NOON TO 9 PM CDT WEDNESDAY FOR IAZ010-011-
018-019-029-030.
HEAT ADVISORY FROM NOON TO 7 PM CDT WEDNESDAY FOR IAZ008-
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION.....MW
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1252 PM CDT TUE JUL 24 2012
.SHORT TERM...
1240 PM CDT TUE JUL 24 2012
AFTER ANALYZING A GOOD PORTION OF THE EARLY MORNING GUIDANCE
COMING IN...IT SEEMS PRETTY CERTAIN THAT HEAT ADVISORY CRITERIA
CONDITIONS WILL BE MET OVER THE SOUTHERN PORTION OF THE FORECAST
AREA TOMORROW AFTERNOON. THUS AFTER COORDINATION WITH SURROUNDING
OFFICES WE ISSUED A HEAT ADVISORY FOR NORTHEAST IA AND SOUTHWEST
WI.
ALSO MONITORING THE MESOSCALE CONVECTIVE VORTEX SPINNING INTO THE
NORTHERN TWIN CITIES AREA...WHICH IS HELPING TO FUEL A LINE OF
THUNDERSTORMS FROM RED WING AND WABASHA BACK TO NEAR MANKATO. THIS
ACTIVITY IS BEING ENHANCED ALONG THE DIFFERENTIAL HEATING BOUNDARY
WHERE THE CLEAR AND MUGGY AIRMASS OVER SOUTHERN MN IS FEEDING INTO
THE COOL AIR ACROSS CENTRAL MN. THE LATEST 15Z HRRR MODEL SEEMS TO
HAVE A GOOD HANDLE ON THIS DEVELOPMENT AND TAKES A CONVECTIVE LINE
DOWN ACROSS THE AREA LATER THIS AFTERNOON. WILL MAKE ADJUSTMENTS
TO THE FORECAST GRIDS AND TEXT FORECASTS AS THIS MOVES THROUGH.
.LONG TERM...FRIDAY THROUGH MONDAY
330 AM CDT TUE JUL 24 2012
24.00 FORECAST MODELS ARE IN AGREEMENT FRIDAY THROUGH SATURDAY
INDICATING SURFACE NORTHWEST FLOW ALOFT AND SURFACE HIGH PRESSURE IN
PLACE ACROSS THE UPPER MISSISSIPPI RIVER VALLEY. PLAN ON VERY
COMFORTABLE TEMPERATURES ON FRIDAY WITH HIGHS RANGING FROM THE MID 70S
ACROSS NORTHERN WISCONSIN TO AROUND 80 OVER NORTHEAST IOWA. ANOTHER
PLEASANT DAY IS ANTICIPATED ACROSS THE REGION ON SATURDAY WITH
MOSTLY SUNNY SKIES AND HIGHS IN THE 80S. A WEAK EMBEDDED SHORTWAVE
WILL MOVE INTO THE REGION LATE SATURDAY NIGHT INTO SUNDAY BRINGING A
CHANCE OF SHOWERS AND THUNDERSTORMS TO THE AREA. SHOWER AND
THUNDERSTORM CHANCES WILL CONTINUE THROUGH MONDAY AS WEAK UPPER LEVEL
SHORTWAVES MOVE ACROSS THE UPPER MIDWEST. TEMPERATURES LOOK TO HOVER
AROUND SEASONAL VALUES WITH HIGHS RANGING FROM THE LOWER TO UPPER
80S.
&&
.AVIATION...THROUGH 18Z WEDNESDAY
1240 PM CDT TUE JUL 24 2012
MONITORING THE MESOSCALE CONVECTIVE VORTEX SPINNING INTO THE
NORTHERN TWIN CITIES AREA...WHICH IS HELPING TO FUEL A LINE OF
THUNDERSTORMS FROM RED WING AND WABASHA BACK TO NEAR MANKATO. THIS
ACTIVITY IS BEING ENHANCED ALONG THE DIFFERENTIAL HEATING BOUNDARY
WHERE THE CLEAR AND MUGGY AIRMASS OVER SOUTHERN MN IS FEEDING INTO
THE COOL AIR ACROSS CENTRAL MN. THE LATEST 15Z HRRR MODEL SEEMS TO
HAVE A GOOD HANDLE ON THIS DEVELOPMENT AND TAKES A CONVECTIVE LINE
DOWN ACROSS THE TAF LOCATIONS BETWEEN 21Z AND 23Z. BEYOND
THAT...IT APPEARS THAT MOST OF THE CONVECTION THREAT WILL SHIFT
NORTH AND EAST OF THE TAF LOCATIONS. PLAYED THE FORECASTS THAT WAY
FOR THE 18Z ISSUANCE.
THERE IS SOME INDICATION VIA MODEL GUIDANCE THAT WE COULD SEE SOME
LIGHT FOG DEVELOP LATE TONIGHT DUE TO THE ADDITION OF THE BOUNDARY
LAYER MOISTURE VIA RAINFALL. HOWEVER...WITH SOUTHERLY WINDS ON THE
INCREASE...FEEL THE LOWER ATMOSPHERE WILL BE TOO MIXED TO ALLOW
FOR LIGHT FOG/MIST DEVELOPMENT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
1240 PM CDT TUE JUL 24 2012
WI...HEAT ADVISORY FROM NOON TO 7 PM CDT WEDNESDAY FOR WIZ053>055-061.
MN...NONE.
IA...HEAT ADVISORY FROM NOON TO 7 PM CDT WEDNESDAY FOR IAZ008>011-018-
019-029-030.
&&
$$
SHORT TERM...MW
LONG TERM...WETENKAMP
AVIATION...MW
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1201 PM CDT TUE JUL 24 2012
.AVIATION/18Z TAFS/...VFR FOR THIS FORECAST PERIOD. MAIN CONCERN
WILL BE ON PRECIP/CONVECTION ASSOCIATED WITH 850 BAROCLINIC ZONE
AND RETURN LOW LEVEL JET TONIGHT. MAIN FOCUS EXPECTED TO BE ACROSS
NW WI...THOUGH MESO MODELS DO DEVELOP SCATTERED CONVECTION ACROSS
SRN WI LATER TONIGHT. ANY MVFR CEILINGS EXPECTED TO BE SHORT
LIVED. CONVECTION EXPECTED TO WHISK NE AS HOT AIRMASS OVERTAKES
THE AREA. THE NAM AND GFS APPEAR TOO QUICK AND FAR SOUTHEAST INTO
THE HOT AIRMASS WITH THE QPF WEDNESDAY AFTERNOON. MAY NEED TO WAIT
FOR BETTER LOW LEVEL FRONTAL FORCING TO BREAK THE CAP WEDNESDAY EVENING.
PC
&&
.PREV DISCUSSION... /ISSUED 1000 AM CDT TUE JUL 24 2012/
UPDATE...HOISTED HEAT ADVISORY FOR WEDNESDAY. IMPRESSIVELY HOT
THERMAL AXIS DRIVES INTO SRN WI. 925 TEMPS SOAR INTO THE LOW TO
MID 30S AND 850 TEMPS 26-29C...VERY CONDUCIVE TO OPPRESSIVELY HOT
TEMPERATURES. HIGHER DEW POINTS EXPECTED...UPPER 60S/LOW 70S. NAM
DEWS WHICH HAVE BEEN BETTER OF LATE ARE EVEN SUGGESTING SOME DEWS
NEAR 70. GFS DEWS IN MID 70S...TYPICALLY TOO MOIST...THOUGH BL
LAYER BECOMING MORE FAVORABLE FOR HIGHER DEWS WITH THE RECENT
RAINS IN SOME AREAS.
PC
PREV DISCUSSION... /ISSUED 339 AM CDT TUE JUL 24 2012/
TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM
DIMINISHING TREND NOTED IN CONVECTION OVER SOUTHWEST WI OVER LAST
HOUR OR SO. SCATTERED TO NUMEROUS CONVECTION EXTENDS WELL TO THE
WEST ACROSS SOUTHERN MN INTO EASTERN SODAK. HOWEVER FRONTAL
BOUNDARY SAGGING ACROSS SOUTHERN WI ATTM...WL CONTINUE INTO NRN IL
EARLY THIS MRNG. THIS WILL TIGHTEN THE BAROCLINICITY ACROSS
SOUTHERN WI AND INCREASE THE LOW LEVEL FN VECTOR RESPONSE TO
FRONTOGENESIS. THIS SHOULD HELP CONTINUE THE SCATTERED TO NUMEROUS
CONVECTION OVER PORTIONS OF SOUTHERN WISCONSIN THROUGH MID-MORNING
BEFORE DIMINISHING. PWAT VALUES IN THE 1.75 TO 2.0 INCH
RANGE...WHICH IS ABOUT 160 PERCENT OF NORMAL. BOTH THE RAP AND
NAM40KM SHOW LAYER FWF LINGERING OVER SOUTH CENTRAL WI TO AROUND 15Z
BEFORE DIMINISHING. HENCE WL CONTINUE LIKELY WORDING IN THE SOUTH
CENTRAL AREAS...DIMINISHING TO CHC/SCT IN THE NORTHEAST.
UPSTREAM SHORT WAVE OVER ERN SODAK IS EXPECTED TO MOVE ESE ACROSS
SRN MN INTO SRN WI LATER THIS MRNG...SO WL CONTINUE CHANCE INTO THE
LATE MORNING. SHORT WAVE AND FRONTOGENETICAL FORCING WEAKENS AND
SLIDES SOUTHEAST FOR THE AFTN.
STRONG SURGE OF RETURN FLOW AND LOW LEVEL THETA-E ADVECTION
ACCOMPANY DEVELOPING LOW LEVEL JET TONIGHT. FOCUS OF LLJ TO THE
NORTHWEST OF CWA...HOWEVER STILL GET CLIPPED BY INCREASING WARM AIR
ADVECTION. HENCE WL CONTINUE LIKELY POPS IN THE NORTH TONIGHT.
WEDNESDAY AND THURSDAY...FORECAST CONFIDENCE...MEDIUM
CONVECTION NEAR WARM FRONT SHOULD WIND DOWN WEDNESDAY MORNING ACROSS
THE NORTHERN FORECAST AREA. WARM FRONT THEN EXPECTED TO LINGER JUST
NORTH OF THE CWA THROUGH THE DAY. MODELS INDICATING THAT TEMPS WILL
SOAR IN THE WARM SECTOR...WITH 925 MB TEMPS UP TO AROUND 32C ON THE
ECMWF AND EVEN WARMER WITH THE NAM. CONCERN IS CERTAINLY THERE THAT
OVERNIGHT CONVECTION MAY KEEP THE WARM FRONT FARTHER SOUTH...AND
THEN ALSO PULL IN COOLER AIR OFF THE LAKE NORTH OFF THE FRONT. FOR
NOW THOUGH...WENT WITH WHAT THE MODELS ARE SHOWING AND BUMPED TEMPS
UP TO AROUND 100 MOST PLACES...EXCEPT FOR IN THE NORTH TOWARD THE
WARM FRONT. TOO MUCH UNCERTAINTY WITH LINGERING CONVECTION/CLOUDS
AND PLACEMENT OF THE WARM FRONT...SO HELD OFF ON HEAT ADVISORY FOR
NOW. WILL EVENTUALLY NEED ONE IF MODELS CONTINUE DOWN THIS ROAD AND
FORECAST CONFIDENCE INCREASES. EVEN WITH DEWPOINTS MIXING INTO THE
MID AND UPPER 60S...TEMPS AROUND 100 WOULD RESULT IN HEAT INDICES IN
THE 100-105 RANGE.
CONVECTION WITH THE TRAILING COLD FRONT IS EXPECTED TO MAINLY HOLD
OFF UNTIL THE EVENING AND OVERNIGHT HOURS. WITH 30 KT LLJ ACROSS THE
AREA AND CAPES IN EXCESS OF 1000 J/KG...STILL THINKING STORMS SEVERE
STORMS ARE A POSSIBILITY AND SPC IS MAINTAINING A SLIGHT RISK.
KEPT SOME POPS THURSDAY MORNING...AS THE ECMWF LINGERS POST FRONTAL
PRECIP. OTHERWISE...SHOULD MAINLY BE DRY THURSDAY. A WEAK WAVE MAY
BRING A FEW MORE SHOWERS/STORMS TO THE AREA LATER IN THE DAY AND
OVERNIGHT.
THINKING THE SUN MAY POKE OUT FOR A TIME THURSDAY...SO PUSHED HIGHS
UP INTO THE MID AND UPPER 80S PER 925 MB TEMPS IN THE 22-25C RANGE.
FRIDAY AND SATURDAY...FORECAST CONFIDENCE...MEDIUM
PRECIP MAY LINGER INTO FRIDAY MORNING AS THE SHORTWAVE EXITS...WITH
DRY WEATHER EXPECTED SATURDAY AS SFC HIGH PRESSURE MOVES OVERHEAD.
SHOULD SEE HIGHS COMFORTABLY NEAR NORMAL BOTH DAYS.
SUNDAY AND MONDAY...FORECAST CONFIDENCE...MEDIUM
WITH UPPER RIDGE BUILDING IN TO THE WEST SUNDAY AND
MONDAY...COMBINATION OF WARM AIR ADVECTION AND A WEAK WAVE OR TWO
MAY KICK OFF SHOWERS/STORMS AT TIMES. WILL LIKELY SEE TEMPS START TO
WARM BACK UP.
AVIATION/12Z TAFS/...SCATTERED TO NUMEROUS CONVECTION LIKELY THIS
MORNING WITH MOST NUMEROUS CONVECTION TOWARDS KMSN. ENOUGH RAINFALL
TO MOISTEN LOW LEVELS EXPECTED TO PRODUCE PERIOD OF MVFR CIGS AT
KMSN. NOT AS CONFIDENT ON LOW CIGS FARTHER EAST WHERE RAINFALL MAY
BE A BIT MORE SCATTERED. MAY USE A TEMPO GROUP WITH 12Z ISSUANCE.
ANY LOWER CIGS SHOULD LIFT TO VFR THIS AFTN AS FORCING SLIDES SOUTH
OF AREA AND SLIGHTLY DRIER AIR GETS PULLED INTO THE LOWER LEVELS.
MORE SCT CONVECTION TONIGHT WITH STRONG RETURN FLOW.
MARINE...ONE TO TWO HOURS OF GUSTY NORTHEAST WINDS ACCOMPANIED
FROPA AS IT MOVED SOUTH ALONG THE LAKE MICHIGAN SHORE EARLY THIS
MORNING. THE FRONT WILL CONTINUE SAGGING SOUTHWARD WITH NORTHEAST
WINDS SETTLING DOWN TO 5 TO 15 KNOTS. SCATTERED T TO AFFECT NEAR
SHORE WATERS THIS MORNING AND AGAIN LATER TNGT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...HEAT ADVISORY FROM 11 AM TO 9 PM CDT WEDNESDAY FOR WIZ051-052-
058>060-062>072.
HEAT ADVISORY FROM 11 AM TO 7 PM CDT WEDNESDAY FOR WIZ046-047-
056-057.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...MBK
WEDNESDAY THROUGH MONDAY...DDV
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1000 AM CDT TUE JUL 24 2012
.UPDATE...HOISTED HEAT ADVISORY FOR WEDNESDAY. IMPRESSIVELY HOT
THERMAL AXIS DRIVES INTO SRN WI. 925 TEMPS SOAR INTO THE LOW TO
MID 30S AND 850 TEMPS 26-29C...VERY CONDUCIVE TO OPPRESSIVELY HOT
TEMPERATURES. HIGHER DEW POINTS EXPECTED...UPPER 60S/LOW 70S. NAM
DEWS WHICH HAVE BEEN BETTER OF LATE ARE EVEN SUGGESTING SOME DEWS
NEAR 70. GFS DEWS IN MID 70S...TYPICALLY TOO MOIST...THOUGH BL
LAYER BECOMING MORE FAVORABLE FOR HIGHER DEWS WITH THE RECENT
RAINS IN SOME AREAS.
PC
&&
.PREV DISCUSSION... /ISSUED 339 AM CDT TUE JUL 24 2012/
TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM
DIMINISHING TREND NOTED IN CONVECTION OVER SOUTHWEST WI OVER LAST
HOUR OR SO. SCATTERED TO NUMEROUS CONVECTION EXTENDS WELL TO THE
WEST ACROSS SOUTHERN MN INTO EASTERN SODAK. HOWEVER FRONTAL
BOUNDARY SAGGING ACROSS SOUTHERN WI ATTM...WL CONTINUE INTO NRN IL
EARLY THIS MRNG. THIS WILL TIGHTEN THE BAROCLINICITY ACROSS
SOUTHERN WI AND INCREASE THE LOW LEVEL FN VECTOR RESPONSE TO
FRONTOGENESIS. THIS SHOULD HELP CONTINUE THE SCATTERED TO NUMEROUS
CONVECTION OVER PORTIONS OF SOUTHERN WISCONSIN THROUGH MID-MORNING
BEFORE DIMINISHING. PWAT VALUES IN THE 1.75 TO 2.0 INCH
RANGE...WHICH IS ABOUT 160 PERCENT OF NORMAL. BOTH THE RAP AND
NAM40KM SHOW LAYER FWF LINGERING OVER SOUTH CENTRAL WI TO AROUND 15Z
BEFORE DIMINISHING. HENCE WL CONTINUE LIKELY WORDING IN THE SOUTH
CENTRAL AREAS...DIMINISHING TO CHC/SCT IN THE NORTHEAST.
UPSTREAM SHORT WAVE OVER ERN SODAK IS EXPECTED TO MOVE ESE ACROSS
SRN MN INTO SRN WI LATER THIS MRNG...SO WL CONTINUE CHANCE INTO THE
LATE MORNING. SHORT WAVE AND FRONTOGENETICAL FORCING WEAKENS AND
SLIDES SOUTHEAST FOR THE AFTN.
STRONG SURGE OF RETURN FLOW AND LOW LEVEL THETA-E ADVECTION
ACCOMPANY DEVELOPING LOW LEVEL JET TONIGHT. FOCUS OF LLJ TO THE
NORTHWEST OF CWA...HOWEVER STILL GET CLIPPED BY INCREASING WARM AIR
ADVECTION. HENCE WL CONTINUE LIKELY POPS IN THE NORTH TONIGHT.
WEDNESDAY AND THURSDAY...FORECAST CONFIDENCE...MEDIUM
CONVECTION NEAR WARM FRONT SHOULD WIND DOWN WEDNESDAY MORNING ACROSS
THE NORTHERN FORECAST AREA. WARM FRONT THEN EXPECTED TO LINGER JUST
NORTH OF THE CWA THROUGH THE DAY. MODELS INDICATING THAT TEMPS WILL
SOAR IN THE WARM SECTOR...WITH 925 MB TEMPS UP TO AROUND 32C ON THE
ECMWF AND EVEN WARMER WITH THE NAM. CONCERN IS CERTAINLY THERE THAT
OVERNIGHT CONVECTION MAY KEEP THE WARM FRONT FARTHER SOUTH...AND
THEN ALSO PULL IN COOLER AIR OFF THE LAKE NORTH OFF THE FRONT. FOR
NOW THOUGH...WENT WITH WHAT THE MODELS ARE SHOWING AND BUMPED TEMPS
UP TO AROUND 100 MOST PLACES...EXCEPT FOR IN THE NORTH TOWARD THE
WARM FRONT. TOO MUCH UNCERTAINTY WITH LINGERING CONVECTION/CLOUDS
AND PLACEMENT OF THE WARM FRONT...SO HELD OFF ON HEAT ADVISORY FOR
NOW. WILL EVENTUALLY NEED ONE IF MODELS CONTINUE DOWN THIS ROAD AND
FORECAST CONFIDENCE INCREASES. EVEN WITH DEWPOINTS MIXING INTO THE
MID AND UPPER 60S...TEMPS AROUND 100 WOULD RESULT IN HEAT INDICES IN
THE 100-105 RANGE.
CONVECTION WITH THE TRAILING COLD FRONT IS EXPECTED TO MAINLY HOLD
OFF UNTIL THE EVENING AND OVERNIGHT HOURS. WITH 30 KT LLJ ACROSS THE
AREA AND CAPES IN EXCESS OF 1000 J/KG...STILL THINKING STORMS SEVERE
STORMS ARE A POSSIBILITY AND SPC IS MAINTAINING A SLIGHT RISK.
KEPT SOME POPS THURSDAY MORNING...AS THE ECMWF LINGERS POST FRONTAL
PRECIP. OTHERWISE...SHOULD MAINLY BE DRY THURSDAY. A WEAK WAVE MAY
BRING A FEW MORE SHOWERS/STORMS TO THE AREA LATER IN THE DAY AND
OVERNIGHT.
THINKING THE SUN MAY POKE OUT FOR A TIME THURSDAY...SO PUSHED HIGHS
UP INTO THE MID AND UPPER 80S PER 925 MB TEMPS IN THE 22-25C RANGE.
FRIDAY AND SATURDAY...FORECAST CONFIDENCE...MEDIUM
PRECIP MAY LINGER INTO FRIDAY MORNING AS THE SHORTWAVE EXITS...WITH
DRY WEATHER EXPECTED SATURDAY AS SFC HIGH PRESSURE MOVES OVERHEAD.
SHOULD SEE HIGHS COMFORTABLY NEAR NORMAL BOTH DAYS.
SUNDAY AND MONDAY...FORECAST CONFIDENCE...MEDIUM
WITH UPPER RIDGE BUILDING IN TO THE WEST SUNDAY AND
MONDAY...COMBINATION OF WARM AIR ADVECTION AND A WEAK WAVE OR TWO
MAY KICK OFF SHOWERS/STORMS AT TIMES. WILL LIKELY SEE TEMPS START TO
WARM BACK UP.
AVIATION/12Z TAFS/...SCATTERED TO NUMEROUS CONVECTION LIKELY THIS
MORNING WITH MOST NUMEROUS CONVECTION TOWARDS KMSN. ENOUGH RAINFALL
TO MOISTEN LOW LEVELS EXPECTED TO PRODUCE PERIOD OF MVFR CIGS AT
KMSN. NOT AS CONFIDENT ON LOW CIGS FARTHER EAST WHERE RAINFALL MAY
BE A BIT MORE SCATTERED. MAY USE A TEMPO GROUP WITH 12Z ISSUANCE.
ANY LOWER CIGS SHOULD LIFT TO VFR THIS AFTN AS FORCING SLIDES SOUTH
OF AREA AND SLIGHTLY DRIER AIR GETS PULLED INTO THE LOWER LEVELS.
MORE SCT CONVECTION TONIGHT WITH STRONG RETURN FLOW.
MARINE...ONE TO TWO HOURS OF GUSTY NORTHEAST WINDS ACCOMPANIED
FROPA AS IT MOVED SOUTH ALONG THE LAKE MICHIGAN SHORE EARLY THIS
MORNING. THE FRONT WILL CONTINUE SAGGING SOUTHWARD WITH NORTHEAST
WINDS SETTLING DOWN TO 5 TO 15 KNOTS. SCATTERED T TO AFFECT NEAR
SHORE WATERS THIS MORNING AND AGAIN LATER TNGT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...HEAT ADVISORY FROM 11 AM TO 9 PM CDT WEDNESDAY FOR WIZ051-052-
058>060-062>072.
HEAT ADVISORY FROM 11 AM TO 7 PM CDT WEDNESDAY FOR WIZ046-047-
056-057.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...MBK
WEDNESDAY THROUGH MONDAY...DDV
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
622 AM CDT TUE JUL 24 2012
.SHORT TERM...TODAY THROUGH THURSDAY
330 AM CDT TUE JUL 24 2012
FORECAST CONCERNS ARE ON SHOWER AND THUNDERSTORM CHANCES TODAY
THOUGH THURSDAY...WITH THE POTENTIAL FOR A ROUND OF SEVERE
THUNDERSTORMS THIS AFTERNOON WEST OF THE MISSISSIPPI RIVER...THEN
ACROSS THE ENTIRE AREA ON WEDNESDAY. ADDITIONAL CONCERNS ARE ON
HEAT INDEX VALUES WEDNESDAY AFTERNOON...WHEN INDICES COULD CLIMB
TO AROUND 105 FOR LOCATIONS ALONG AND SOUTH OF INTERSTATE 90.
LATEST RADAR IMAGERY SHOWED A BAND OF SHOWERS AND THUNDERSTORMS
EXTENDING FROM FAR NORTHEAST SOUTH DAKOTA...THROUGH CENTRAL
MINNESOTA TO ALONG THE MISSISSIPPI RIVER INTO FAR SOUTHWEST
WISCONSIN. BRIEF HEAVY DOWNPOURS AND WIND GUSTS IN THE 30 TO 40 KT
RANGE HAVE BEEN REPORTED WITH SOME OF THE STORMS.
SHOWERS AND THUNDERSTORMS WILL BE ONGOING THIS MORNING ACROSS
PORTIONS OF SOUTHEAST MINNESOTA...NORTHEAST IOWA AND SOUTHWEST AND
WEST CENTRAL WISCONSIN AS STRONG 850 MB MOISTURE TRANSPORT IS
FOCUSED ALONG AND WEST OF THE MISSISSIPPI RIVER. THE LOW LEVEL JET
WILL START TO SUBSIDE THIS MORNING WITH THE SHOWERS AND STORMS
GRADUALLY TAPERING OFF AND SHIFTING TO THE SOUTHEAST. A WARM FRONT
WILL BE POSITIONED FROM SOUTHWEST MINNESOTA INTO NORTHEAST IOWA..AND
NORTHERN ILLINOIS THIS AFTERNOON. THE FRONT WILL BE THE FOCUS FOR
SHOWER AND THUNDERSTORM DEVELOPMENT THIS AFTERNOON INTO TONIGHT AS
IT LIFTS NORTHEAST AS SURFACE LOW PRESSURE DEEPENS OVER SOUTHEAST
SOUTH DAKOTA. AFTERNOON MUCAPE VALUES INCREASE INTO THE 2500-3500
J/KG RANGE BY 21Z THIS AFTERNOON. 0-6 KM BULK SHEAR WILL BE AROUND
40 KTS THIS AFTERNOON LEADING TO THE POTENTIAL FOR A FEW STRONG TO
SEVERE THUNDERSTORMS. HOWEVER...THERE WILL BE A VERY STRONG CAP IN
PLACE WITH 850 MB TEMPERATURE CLIMBING TO INTO THE MID 20S LATE
THIS AFTERNOON INTO THIS EVENING. THINKING THAT CONVECTION WILL
LIKELY WAIT TO FIRE UNTIL THIS EVENING AS MOISTURE TRANSPORT AND
STRONG 850 MB WARM AIR ADVECTION RAPIDLY INCREASE...LEADING TO
WIDESPREAD ELEVATED CONVECTION. AT THIS TIME IT APPEARS THE
SHOWERS AND STORMS SHOULD FIRE ACROSS SOUTHEAST MINNESOTA INTO
SOUTHWEST WISCONSIN THIS EVENING...WITH THE HIGHEST CHANCES NORTH
OF A LINE FROM ROCHESTER MN...TO LA CROSSE TO RICHLAND CENTER. THE
NAM SUGGESTS THE BULK OF THIS ACTIVITY SHOULD FIRE ALONG AND EAST
OF THE MISSISSIPPI RIVER...SO WILL HAVE TO KEEP A CLOSE WATCH ON
THIS. PRECIPITATION CHANCES MAY NEED TO BE FOCUSED MORE ACROSS
THESE AREAS DURING THE OVERNIGHT HOURS. FORECAST SOUNDINGS SHOW
AROUND 1500 J/KG ELEVATED CAPE WHEN LIFTING FROM 800 MB. OVERALL
SHEAR LOOKS MARGINAL WITH 1-6 KM BULK SHEAR OF 30 TO 38 KTS. COULD
SEE SOME MARGINALLY SEVERE HAIL TONIGHT WITH SOME OF THE STORMS
AND POSSIBLY SOME GUSTY WINDS. THE MAIN THREAT LOOKS TO BE BRIEF
HEAVY RAIN AND FREQUENT LIGHTNING. THE HIGHEST CHANCES FOR STRONG
TO SEVERE STORMS WOULD BE MAINLY ALONG AND EAST OF THE MISSISSIPPI
WHERE SHEAR IS A LITTLE STRONGER.
THE WARM FRONT IS EXPECTED TO PUSH INTO NORTHERN WISCONSIN WEDNESDAY
MORNING AS SURFACE LOW PRESSURE MOVES INTO SOUTHWEST MINNESOTA. THIS
WILL LEAVE MUCH OF THE FORECAST AREA IN THE WARM SECTOR FROM
WEDNESDAY MORNING INTO WEDNESDAY AFTERNOON. HOT AIR WILLS SURGE
NORTH INTO THE AREA...WITH TEMPERATURES EXPECTED TO CLIMB INTO THE
MID TO UPPER 90S. A FEW LOCATIONS ACROSS NORTHEAST IOWA AND FAR
SOUTHWEST WISCONSIN COLD REACH THE 100 DEGREE MARK. THIS SURGE OF HOT
AIR WILL LEAD TO HEAT INDEX CONCERNS. THE DEWPOINTS MAY MIX OUT
DURING THE DAY BUT SHOULD AT LEAST HOLD IN THE 60S. EVEN IF THE
DEWPOINTS FALL AS FORECAST SOUNDINGS SUGGEST...WITH INVERTED V TYPE
SOUNDINGS...WILL STILL SEE THE HOT TEMPERATURES SURGE INTO THE AREA.
A HEAT ADVISORY WILL LIKELY BE NEEDED ON WEDNESDAY. A COLD FRONT IS
EXPECTED TO PUSH INTO THE ARE FROM THE NORTHWEST WEDNESDAY
AFTERNOON. HOW FAR SOUTH THIS FRONT GETS DURING THE AFTERNOON HOURS
WILL DETERMINE WHAT AREAS WILL EXPERIENCE THE HOTTEST TEMPERATURES.
CURRENT THINKING IS THAT AREAS ALONG AND SOUTH OF INTERSTATE 90 WILL
NEED A HEAT ADVISORY WEDNESDAY AFTERNOON...WHERE HEAT INDEX VALUES
ARE EXPECTED TO CLIMB INTO THE 100-105 DEGREE RANGE. WILL HAVE TO
KEEP A CLOSE WATCH ON THE WARM FRONT ON WEDNESDAY FOR THE OUTSIDE
CHANCE OF AN ISOLATED TORNADO...ESPECIALLY FOR LOCATIONS ALONG AND
NORTH OF I-94. THE SURFACE LOW IS EXPECTED TO PUSH INTO SOUTHEAST
MINNESOTA EARLY WEDNESDAY AFTERNOON. 0-1 KM SHEAR INCREASES INTO THE
20 TO 30 KT RANGE BY 18Z ALONG AND NORTH OF I-94...WITH MLCAPE
VALUES CLIMBING TO AROUND 2500 J/KG RIGHT ALONG THE WARM FRONT. LCL
HEIGHTS REALLY CLIMB IN THE WARM SECTOR DURING THE AFTERNOON HOURS
BUT FEEL THERE IS THE POTENTIAL FOR THE WARM FRONT TO STALL A LITTLE
FURTHER SOUTH THAN MODEL GUIDANCE SUGGEST WITH AN MCS ROLLING ACROSS
FAR NORTHERN WISCONSIN POTENTIALLY PUSHING AN OUT FLOW BOUNDARY
SOUTHWARD STALLING THE FRONT. ANOTHER FACTOR LEANING AGAINST STORMS
DEVELOPING NEAR THE WARM FRONT IS A STRONG CAP IN PLACE...WITH
SURFACE BASED CIN OF NEARLY NEGATIVE 300 J/KG. THE COLD FRONT WILL
DRIFT SOUTHEAST ACROSS THE FORECAST AREA THROUGH THE AFTERNOON WITH
SHOWERS AND THUNDERSTORMS DEVELOPING ALONG THE FRONT. THE STRONGEST
SHEAR TO SUPPORT ORGANIZED CONVECTION WILL BE LOCATED RIGHT ALONG
AND BEHIND THE FRONT. THE INVERTED V TYPE SOUNDINGS IN THE WARM
SECTOR LEAD TO DAMAGING WIND CONCERNS WITH ANY THUNDERSTORMS THAT
MAY DEVELOP ALONG THE FRONT. GIVEN THE STRONG INSTABILITY THAT
DEVELOPS WEDNESDAY AFTERNOON...MUCAPE AROUND 3000 J/KG CANNOT RULE
OUT SOME LARGE HAIL WITH THE STORMS WEDNESDAY AFTERNOON.
THE COLD FRONT IS EXPECTED TO MOVE INTO SOUTHERN IOWA AND CENTRAL
IOWA LATE WEDNESDAY NIGHT WITH SHOWER AND THUNDERSTORM CHANCES
SHIFTING SOUTH OF THE FORECAST AREA LATE. A POTENT UPPER LEVEL
TROUGH WILL DIVE INTO NORTHERN MINNESOTA EARLY THURSDAY MORNING AND
IS EXPECTED TO PROGRESS SOUTHEAST INTO NORTHWEST BY EARLY THURSDAY
AFTERNOON. THE TROUGH WILL MOVE INTO THE FORECAST AREA LATE THURSDAY
AFTERNOON INTO EARLY THURSDAY EVENING BRINGING A CHANCE OF SHOWERS
AND THUNDERSTORMS TO THE AREA. FORECAST SOUNDINGS SHOW SURFACE BASED
CAPE INCREASING TO AROUND 1500 J/KG AHEAD OF THIS WAVE. 0-6 KM BULK
SHEAR IS EXPECTED TO BE AROUND 40 KTS...SO THINKING THERE COULD BE
ORGANIZED CONVECTION DURING THE AFTERNOON HOURS. THE STRONGEST
FORCING ALOFT PASSES OVER NORTHERN AND NORTH CENTRAL WISCONSIN SO
HIGHEST THUNDERSTORM CHANCES WILL BE ACROSS THESE AREAS. WILL HAVE
TO KEEP A CLOSE EYE ON THE NEXT FEW MODEL RUNS WITH THE POTENTIAL
FOR A FEW SEVERE STORMS THURSDAY AFTERNOON. HIGHS ON THURSDAY WILL
BE MORE SEASONABLE WITH TEMPERATURES RANGING FROM THE LOWER 80S
ACROSS NORTHERN WISCONSIN TO THE UPPER 80S OVER NORTHEAST IOWA.
.LONG TERM...FRIDAY THROUGH MONDAY
330 AM CDT TUE JUL 24 2012
24.00 FORECAST MODELS ARE IN AGREEMENT FRIDAY THROUGH SATURDAY
INDICATING SURFACE NORTHWEST FLOW ALOFT AND SURFACE HIGH PRESSURE IN
PLACE ACROSS THE UPPER MISSISSIPPI RIVER VALLEY. PLAN ON VERY
COMFORTABLE TEMPERATURES ON FRIDAY WITH HIGHS RANGING FROM THE MID 70S
ACROSS NORTHERN WISCONSIN TO AROUND 80 OVER NORTHEAST IOWA. ANOTHER
PLEASANT DAY IS ANTICIPATED ACROSS THE REGION ON SATURDAY WITH
MOSTLY SUNNY SKIES AND HIGHS IN THE 80S. A WEAK EMBEDDED SHORTWAVE
WILL MOVE INTO THE REGION LATE SATURDAY NIGHT INTO SUNDAY BRINGING A
CHANCE OF SHOWERS AND THUNDERSTORMS TO THE AREA. SHOWER AND
THUNDERSTORM CHANCES WILL CONTINUE THROUGH MONDAY AS WEAK UPPER LEVEL
SHORTWAVES MOVE ACROSS THE UPPER MIDWEST. TEMPERATURES LOOK TO HOVER
AROUND SEASONAL VALUES WITH HIGHS RANGING FROM THE LOWER TO UPPER
80S.
&&
.AVIATION...TODAY AND TONIGHT
622 AM CDT TUE JUL 24 2012
REGIONAL RADARS INDICATE THE BAND OF SHOWERS AND THUNDERSTORMS
EXTENDS BACK INTO CENTRAL MINNESOTA AND THEN BECOMES MORE
SCATTERED IN NATURE ACROSS WESTERN MINNESOTA INTO EASTERN SOUTH
DAKOTA. WOULD EXPECT THIS ACTIVITY TO CONTINUE PROPAGATING
SOUTHEAST THIS MORNING WITH THE BACK EDGE DIMINISHING AS THE LOW
LEVEL JET CONTINUES TO TURN AND BECOME MORE OUT OF THE SOUTHWEST
TO WEST. THE 24.08Z HRRR LOOKS TO HAVE A GOOD HANDLE ON THE
CURRENT ACTIVITY AND MAINTAINS A PRETTY SOLID BAND THROUGH ABOUT
14Z AND THEN QUICKLY DIMINISHES IT BETWEEN 14 AND 16Z. THIS MAKES
SENSE AS THE 24.06Z NAM INDICATES THE SHORT WAVE TROUGH SHOULD BE
MOVING OFF TO THE EAST ABOUT THEN. WILL CARRY CATEGORICAL SHOWERS
AT BOTH TAF SITES INTO THE MID MORNING AND THEN DROP BACK TO VCSH.
THE WARM FRONT TO THE SOUTH WILL MOVE SLOWLY NORTH TONIGHT BUT IS
NOT EXPECTED TO MOVE THROUGH EITHER TAF SITE BY 12Z. AS THE NEXT
SHORT WAVE TROUGH COMES OUT AND THE LOW LEVEL JET INTERSECTS THE
FRONT TONIGHT...ANOTHER ROUND OF SHOWERS AND STORMS IS EXPECTED TO
DEVELOP. MOST OF THIS ACTIVITY LOOKS TO BE NORTH OF THE TAF SITES
WITH KLSE POSSIBLY HAVING A CHANCE OF SEE SOME SCATTERED ACTIVITY.
DID NOT INCLUDE ANY CONVECTION FOR KRST AS THE MID LEVEL WARM AIR
LOOKS TO COME IN AND CAP OFF THAT AREA.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
330 AM CDT TUE JUL 24 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...04
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
339 AM CDT TUE JUL 24 2012
.TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM
DIMINISHING TREND NOTED IN CONVECTION OVER SOUTHWEST WI OVER LAST
HOUR OR SO. SCATTERED TO NUMEROUS CONVECTION EXTENDS WELL TO THE
WEST ACROSS SOUTHERN MN INTO EASTERN SODAK. HOWEVER FRONTAL
BOUNDARY SAGGING ACROSS SOUTHERN WI ATTM...WL CONTINUE INTO NRN IL
EARLY THIS MRNG. THIS WILL TIGHTEN THE BAROCLINICITY ACROSS
SOUTHERN WI AND INCREASE THE LOW LEVEL FN VECTOR RESPONSE TO
FRONTOGENESIS. THIS SHOULD HELP CONTINUE THE SCATTERED TO NUMEROUS
CONVECTION OVER PORTIONS OF SOUTHERN WISCONSIN THROUGH MID-MORNING
BEFORE DIMINISHING. PWAT VALUES IN THE 1.75 TO 2.0 INCH
RANGE...WHICH IS ABOUT 160 PERCENT OF NORMAL. BOTH THE RAP AND
NAM40KM SHOW LAYER FWF LINGERING OVER SOUTH CENTRAL WI TO AROUND 15Z
BEFORE DIMINISHING. HENCE WL CONTINUE LIKELY WORDING IN THE SOUTH
CENTRAL AREAS...DIMINISHING TO CHC/SCT IN THE NORTHEAST.
UPSTREAM SHORT WAVE OVER ERN SODAK IS EXPECTED TO MOVE ESE ACROSS
SRN MN INTO SRN WI LATER THIS MRNG...SO WL CONTINUE CHANCE INTO THE
LATE MORNING. SHORT WAVE AND FRONTOGENETICAL FORCING WEAKENS AND
SLIDES SOUTHEAST FOR THE AFTN.
STRONG SURGE OF RETURN FLOW AND LOW LEVEL THETA-E ADVECTION
ACCOMPANY DEVELOPING LOW LEVEL JET TONIGHT. FOCUS OF LLJ TO THE
NORTHWEST OF CWA...HOWEVER STILL GET CLIPPED BY INCREASING WARM AIR
ADVECTION. HENCE WL CONTINUE LIKELY POPS IN THE NORTH TONIGHT.
.WEDNESDAY AND THURSDAY...FORECAST CONFIDENCE...MEDIUM
CONVECTION NEAR WARM FRONT SHOULD WIND DOWN WEDNESDAY MORNING ACROSS
THE NORTHERN FORECAST AREA. WARM FRONT THEN EXPECTED TO LINGER JUST
NORTH OF THE CWA THROUGH THE DAY. MODELS INDICATING THAT TEMPS WILL
SOAR IN THE WARM SECTOR...WITH 925 MB TEMPS UP TO AROUND 32C ON THE
ECMWF AND EVEN WARMER WITH THE NAM. CONCERN IS CERTAINLY THERE THAT
OVERNIGHT CONVECTION MAY KEEP THE WARM FRONT FARTHER SOUTH...AND
THEN ALSO PULL IN COOLER AIR OFF THE LAKE NORTH OFF THE FRONT. FOR
NOW THOUGH...WENT WITH WHAT THE MODELS ARE SHOWING AND BUMPED TEMPS
UP TO AROUND 100 MOST PLACES...EXCEPT FOR IN THE NORTH TOWARD THE
WARM FRONT. TOO MUCH UNCERTAINTY WITH LINGERING CONVECTION/CLOUDS
AND PLACEMENT OF THE WARM FRONT...SO HELD OFF ON HEAT ADVISORY FOR
NOW. WILL EVENTUALLY NEED ONE IF MODELS CONTINUE DOWN THIS ROAD AND
FORECAST CONFIDENCE INCREASES. EVEN WITH DEWPOINTS MIXING INTO THE
MID AND UPPER 60S...TEMPS AROUND 100 WOULD RESULT IN HEAT INDICES IN
THE 100-105 RANGE.
CONVECTION WITH THE TRAILING COLD FRONT IS EXPECTED TO MAINLY HOLD
OFF UNTIL THE EVENING AND OVERNIGHT HOURS. WITH 30 KT LLJ ACROSS THE
AREA AND CAPES IN EXCESS OF 1000 J/KG...STILL THINKING STORMS SEVERE
STORMS ARE A POSSIBILITY AND SPC IS MAINTAINING A SLIGHT RISK.
KEPT SOME POPS THURSDAY MORNING...AS THE ECMWF LINGERS POST FRONTAL
PRECIP. OTHERWISE...SHOULD MAINLY BE DRY THURSDAY. A WEAK WAVE MAY
BRING A FEW MORE SHOWERS/STORMS TO THE AREA LATER IN THE DAY AND
OVERNIGHT.
THINKING THE SUN MAY POKE OUT FOR A TIME THURSDAY...SO PUSHED HIGHS
UP INTO THE MID AND UPPER 80S PER 925 MB TEMPS IN THE 22-25C RANGE.
.FRIDAY AND SATURDAY...FORECAST CONFIDENCE...MEDIUM
PRECIP MAY LINGER INTO FRIDAY MORNING AS THE SHORTWAVE EXITS...WITH
DRY WEATHER EXPECTED SATURDAY AS SFC HIGH PRESSURE MOVES OVERHEAD.
SHOULD SEE HIGHS COMFORTABLY NEAR NORMAL BOTH DAYS.
.SUNDAY AND MONDAY...FORECAST CONFIDENCE...MEDIUM
WITH UPPER RIDGE BUILDING IN TO THE WEST SUNDAY AND
MONDAY...COMBINATION OF WARM AIR ADVECTION AND A WEAK WAVE OR TWO
MAY KICK OFF SHOWERS/STORMS AT TIMES. WILL LIKELY SEE TEMPS START TO
WARM BACK UP.
&&
.AVIATION/12Z TAFS/...SCATTERED TO NUMEROUS CONVECTION LIKELY THIS
MORNING WITH MOST NUMEROUS CONVECTION TOWARDS KMSN. ENOUGH RAINFALL
TO MOISTEN LOW LEVELS EXPECTED TO PRODUCE PERIOD OF MVFR CIGS AT
KMSN. NOT AS CONFIDENT ON LOW CIGS FARTHER EAST WHERE RAINFALL MAY
BE A BIT MORE SCATTERED. MAY USE A TEMPO GROUP WITH 12Z ISSUANCE.
ANY LOWER CIGS SHOULD LIFT TO VFR THIS AFTN AS FORCING SLIDES SOUTH
OF AREA AND SLIGHTLY DRIER AIR GETS PULLED INTO THE LOWER LEVELS.
MORE SCT CONVECTION TONIGHT WITH STRONG RETURN FLOW.
&&
.MARINE...ONE TO TWO HOURS OF GUSTY NORTHEAST WINDS ACCOMPANIED
FROPA AS IT MOVED SOUTH ALONG THE LAKE MICHIGAN SHORE EARLY THIS
MORNING. THE FRONT WILL CONTINUE SAGGING SOUTHWARD WITH NORTHEAST
WINDS SETTLING DOWN TO 5 TO 15 KNOTS. SCATTERED T TO AFFECT NEAR
SHORE WATERS THIS MORNING AND AGAIN LATER TNGT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...MBK
WEDNESDAY THROUGH MONDAY...DDV
AREA FORECAST DISCUSSION
NWS NEW YORK NY
206 AM EDT THU JUL 26 2012
.SYNOPSIS...
HIGH PRESSURE BUILDS OFFSHORE THIS EVENING AS A POTENT STORM
SYSTEM TRACKS EAST ACROSS THE GREAT LAKES...PASSING TO THE NORTH
ON THURSDAY. A WARM FRONT WILL PASS IN THE MORNING...FOLLOWED BY
A TROUGH OF LOW PRESSURE THURSDAY EVENING. A FRONTAL SYSTEM WILL
SLOWLY PUSH ACROSS AND THEN EAST OF THE REGION FRIDAY THROUGH
SATURDAY NIGHT. WEAK HIGH PRESSURE THEN BUILDS IN SUNDAY INTO THE
BEGINNING OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
CLOUDS FROM CONVECTION ACROSS THE GREAT LAKES HAS MOVED INTO THE
REGION. SOUTHERLY FLOW CONTINUES WITH TEMPERATURES IN THE UPPER
60S TO UPPER 70S. ADJUSTED HOURLY TEMPERATURES FOR TRENDS AND ALSO
RAISED OVERNIGHT LOWS A COUPLE OF DEGREES IN SOME OF THE OUTLYING
AREAS THAT WILL NOT FALL WITH THE CLOUD COVER.
GENERALLY DRY CONDS ON TAP FOR THE OVERNIGHT PERIOD AS HIGH PRES
OVERHEAD MOVES OFFSHORE AFTER MIDNIGHT.
STORM SYSTEM DEVELOPING OVER THE OH VALLEY...AND SHORT TERM MODELS
INDICATING EITHER THE SYSTEM OR REMNANTS OF IT WILL APPROACH
WESTERN PORTIONS OF THE FORECAST AREA TOWARDS THE END OF THE
OVERNIGHT PERIOD. LATEST HRRR MODEL HAS ONE WAVE IMPACTING THE
AREA AFTER MIDNIGHT...THEN ANOTHER WAVE APPROACHING FOR AFTER
SUNRISE THURSDAY MORNING. 18Z NAM HAS THE COMPLEX ENTERING WESTERN
PORTIONS OF THE CWA BY 12Z THURSDAY. WILL CARRY SLIGHT CHANCE POPS
FOR ORANGE COUNTY LATE...AND WILL HOLD OFF ON REST OF POPS UNTIL
THE START OF THE SECOND PERIOD.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/...
WITH EITHER REMNANTS OF OR THE MCS ITSELF APPROACHING THURSDAY
MORNING...WILL GO AHEAD AND INCREASE POPS TO CHANCE STARTING
BETWEEN 10-12Z OVER WESTERN ZONES...THEN WILL SPREAD THOSE POPS
EAST THROUGH 15-17Z. THIS ACTIVITY WILL BE AHEAD OF A WARM FRONT
THAT MOVES NORTH THROUGH THE REGION IN THE MORNING...THEN THE CWA
BECOMES WARM SECTORED IN THE AFTERNOON. WITH LLJ APPROACHING IN
THE MORNING...WILL GO AHEAD AND MENTION GUSTY WINDS IN THE
FORECAST FOR THURSDAY MORNING.
OTHERWISE...AN INITIAL CAP OVER THE AREA IN THE EARLY AFT SHOULD
ERODE WITH A HIGHLY UNSTABLE AIR MASS IN PLACE. MU CAPES OF 2000
TO 3000 J/KG AND 35 TO 40 KT MID LEVEL WINDS WILL SET UP A
FAVORABLE ENVIRONMENT FOR SEVERE WX DURING THE LATE AFTERNOON AND
FIRST HALF OF THE EVENING. CONVERGENCE ALONG AND AHEAD OF THE PRE-
FRONTAL TROF WILL PROVIDE THE LOW-LEVEL FORCING WITH WEAK MID
LEVEL HEIGHT FALLS. THIS FAVORS THE DEVELOPMENT OF A SCATTERED TO
NUMEROUS THUNDERSTORMS. A UNIDIRECTIONAL WIND PROFILE SUPPORTS
MULTIPLE CLUSTERS AND BOWING SEGMENTS WITH THE PRIMARY THREAT
BEING DAMAGING WINDS. SOME WEAKENING OF THE CONVECTION IS EXPECTED
AS IT MOVES OUT ACROSS EASTERN LI AND SE CT. CONVECTION SHOULD
DIMINISH BY MIDNIGHT FROM WEST TO EAST.
AN HWO HAS BEEN UPDATED TO ADDRESS THE SEVERE WEATHER POTENTIAL.
SPC HAS PLACED MOST OF THE AREA UNDER A MODERATE RISK FOR THU AFT
AND EVE. ENHANCED WORDING ADDED TO THE FORECAST TO REFLECT THE
POTENTIAL THESE STORMS WILL HAVE.
PRIOR TO THE ONSET OF THE LATE DAY CONVECTION...A SURGE OF WARM
ALOFT WITH 85H TEMP NEAR 22C WILL ALLOW DAYTIME HIGHS AWAY FROM
THE COAST TO REACH INTO THE LOWER 90S...WITH THE LOW TO MID 80S
ALONG THE COAST. HEAT INDEX VALUES FOR NYC LOOK TO BE JUST BELOW
95.
A WARM...MUGGY NIGHT WILL BE ON TAP THU NIGHT WITH LOW IN THE
LOWER TO MID 70S WITH DEW POINTS AROUND 70. FRONTAL BOUNDARY LOOKS
TO REMAIN JUST NORTH OF THE AREA.
THERE IS A MODERATE RISK OF RIP CURRENTS THURSDAY
MORNING...BECOMING HIGH THURSDAY AFTERNOON THROUGH THURSDAY
EVENING AS WINDS INCREASE TO 15 TO 25 MPH AND SURF BUILDS TO 3 TO
5 FT.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
ACTIVE PERIOD TO START THE LONG TERM WITH A GRADUALLY AMPLIFYING
TROUGH WORKING FROM THE GREAT LAKES TO THE EAST COAST THROUGH
SATURDAY NIGHT. MEANWHILE AT THE SURFACE...A SLOW MOVING COLD
FRONT WITH MULTIPLE WEAK WAVES OF LOW PRESSURE WILL GRADUALLY
MOVES ACROSS AND THEN EAST OF THE REGION.
POTENTIAL FOR SCATTERED STRONG TO SEVERE CONVECTION EXISTS ON FRIDAY
AFTERNOON/EARLY EVENING AS THE COLD FRONT PUSHES THE VERY WARM AND
HUMID AIR MASS OFFSHORE...WITH AT LEAST MODERATE CAPE AND SHEAR. WITH
UNCERTAINTY ON CONVECTIVE DEBRIS...HAVE STAYED CLOSE TO MAV/MET
TEMPS. GENERALLY UPPER 80S/LOWER 90S AREA-WIDE...AND WITH DEWPOINT
POOLING AT LEAST IN THE LOWER 70S...HEAT INDICES IN THE MID TO UPPER
90S FOR MUSH OF THE REGION. MARGINAL HEAT ADVISORY POTENTIAL FOR
NYC/NJ METRO.
THEN SOME UNCERTAINTY FOR FRIDAY NIGHT THROUGH SATURDAY NIGHT IN HOW
FAR OFFSHORE THE COLD FRONT MOVES OFFSHORE AND TIMING OF WEAK WAVES
AND ASSOCIATED AREAS OF PRECIP ALONG THE FRONT. BUT OVERALL WITH
TROUGH AXIS APPROACHING AND FAVORABLE CAPE/SHEAR
ENVIRONMENT...POTENTIAL EXISTS FOR STRONG CONVECTION ACROSS AT LEAST
WESTERN SECTIONS OF THE REGION SAT AFTERNOON/EARLY EVENING.
MODELS IN DECENT AGREEMENT WITH TROUGH AXIS SLIDING EAST SATURDAY
NIGHT...BUT LIKELY GIVING WAY TO MEAN EAST COAST TROUGHING THROUGH
MIDWEEK. AT THE SURFACE BROAD BUT WEAK HIGH PRESSURE BUILDS IN FOR
SUN INTO MON AND THEN PUSHES OFFSHORE ON TUES. THE RESULT WILL NEAR
SEASONABLE CONDITIONS WITH WIDELY SCATTERED DIURNAL CONVECTION SUN
AND MON AFTERNOON.
INCREASING UNCERTAINTY IN DETAILS FOR TUE AND WED...BUT RETURN FLOW
SHOULD ALLOW FOR AN INCREASE IN HUMIDITY LEVELS AND POSSIBLY
INCREASED DIURNAL SHOWER/TSTM COVERAGE.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
HIGH PRESSURE WILL PASS TO THE SOUTH TONIGHT. A WARM FRONT WILL
APPROACH THU MORNING...AND PASS THROUGH LATE THU MORNING OR EARLY
THU AFTERNOON. A COLD FRONT WILL APPROACH TOWARD THU EVENING.
SHOWERS AND TSTMS DEVELOPING OUT AHEAD OF THE WARM FRONT IN SOUTH
CENTRAL NY AND NORTH CENTRAL PA AS OF 0545Z AND HEADING SOUTHEAST
COULD AFFECT KSWF AND KHPN AFTER 07Z. LOW CONFIDENCE IN SEEING
TSTMS AS THE LINE OF TSTMS IN NORTHERN PA COULD TRACK SOUTH OF
THESE TERMINALS.
WHILE TAFS DO NOT HAVE TSTM IN PREVAILING GROUP...THERE IS A LOW
CHANCE OF TSTMS IMPACTING THE NYC METRO BY 13Z-14Z AND KBDR/KISP
BY 14Z-15Z. TSTMS AT KGON BY 15Z-16Z ADDRESSED WITH PROB30. MVFR
CONDITIONS ARE POSSIBLE IF TSTMS DEVELOP.
WHILE WIDESPREAD TSTM IMPACTS FROM A LINE OF STRONG TO SEVER
TSTMS SHOULD BEGIN AFTER 23Z...SOME DISCRETE TSTMS ARE POSSIBLE
BEFORE THAT BEGINNING ABOUT 20Z-21Z. UNTIL THEN...WIND IMPACTS
WILL BE THE GREATER CONCERN...AS SW WINDS INCREASE QUICKLY AFTER
ABOUT 12Z-13Z...WITH SPEEDS AROUND 15 KT WITH GUSTS 20-25 KT IF
NOT BOTH A LITTLE HIGHER IN NYC METRO.
OUTLOOK FOR 00Z FRI THROUGH MONDAY...
.THU EVENING...LINE OF SEVERE TSTMS WITH STRONG WINDS AND IFR
CONDS EXPECTED.
.LATER THU NIGHT THROUGH MON......OCNL IFR CONDITIONS ARE POSSIBLE
WITH LOW CLOUDS AND/OR SHOWERS/TSTMS.
&&
.MARINE...
WINDS AND SEAS FORECAST ON TRACK OVERNIGHT INTO THURSDAY.
TRANQUIL CONDS ON TAP FOR TONIGHT. TSTMS ARE POSSIBLE THURSDAY
MORNING FROM 10-15Z AS STORM SYSTEM APPROACHES FROM THE WEST.
SCA REMAINS UP FOR ALL WATERS FOR A STRENGTHENING SW FLOW THU AND
THU EVE AHEAD OF POTENT STORM SYSTEM WHICH PASSES TO THE NORTH THU
EVE. GUSTS UP TO 30 POSSIBLE ALONG WITH A LINE OF SEVERE
THUNDERSTORMS DURING THE LATE AFT/EVE HOURS.
SW FLOW EXPECTED TO GRADUALLY WEAKEN ON FRIDAY...BUT MARGINAL SCA
SEAS WILL LIKELY LINGER UNTIL THE COLD FRONT PASSES LATE
FRIDAY/FRIDAY EVENING.
ONCE OCEAN SEAS SUBSIDE...LATE FRIDAY/FRI NIGHT...SUB SCA CONDITIONS
EXPECTED IN A WEAK PRESSURE REGIME THROUGH EARLY NEXT WEEK.
&&
.HYDROLOGY...
NO SIGNIFICANT RAINFALL IS EXPECTED THROUGH TONIGHT.
PRECIPITABLE WATERS ARE FORECAST TO INCREASE TO AROUND 2 INCHES
BY THURSDAY AFTERNOON. AS THE RESULT LOCALLY HEAVY RAINFALL IS
POSSIBLE WITH ANY STRONGER CONVECTION...ESPECIALLY THURSDAY EVENING.
WITH A FORECAST STORM MOTION OF AROUND 20 KT...MINOR URBAN/POOR
DRAINAGE FLOODING IS THE MOST LIKELY THREAT. LOCALIZED FLASH
FLOODING CANNOT BE RULED OUT THOUGH...ESPECIALLY IF TRAINING
OCCURS. FOR NOW FORECASTING BASIN AVERAGE QPF AMOUNTS OF AROUND
1/4 TO 1/2 AN INCH WITH LOCALIZED AMOUNTS OF 1-2+ INCHES POSSIBLE.
MAIN THREAT APPEARS TO BE FOR LOCALLY HEAVY RAINFALL FROM DIURNAL
CONVECTION FRIDAY AND SATURDAY AFTERNOON.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 11 PM EDT THIS
EVENING FOR ANZ330-335-338-340-345.
SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 6 AM EDT
FRIDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...NV/DW
NEAR TERM...MPS/DW
SHORT TERM...MPS/DW
LONG TERM...NV
AVIATION...JP
MARINE...NV/DW
HYDROLOGY...MALOIT/MET
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1243 AM EDT THU JUL 26 2012
.SYNOPSIS...
HIGH PRESSURE BUILDS OFFSHORE THIS EVENING AS A POTENT STORM
SYSTEM TRACKS EAST ACROSS THE GREAT LAKES...PASSING TO THE NORTH
ON THURSDAY. A WARM FRONT WILL PASS IN THE MORNING...FOLLOWED BY
A TROUGH OF LOW PRESSURE THURSDAY EVENING. A FRONTAL SYSTEM WILL
SLOWLY PUSH ACROSS AND THEN EAST OF THE REGION FRIDAY THROUGH
SATURDAY NIGHT. WEAK HIGH PRESSURE THEN BUILDS IN SUNDAY INTO THE
BEGINNING OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
CLOUDS FROM CONVECTION ACROSS THE GREAT LAKES HAS MOVED INTO THE
REGION. SOUTHERLY FLOW CONTINUES WITH TEMPERATURES IN THE UPPER
60S TO UPPER 70S. ADJUSTED HOURLY TEMPERATURES FOR TRENDS AND ALSO
RAISED OVERNIGHT LOWS A COUPLE OF DEGREES IN SOME OF THE OUTLYING
AREAS THAT WILL NOT FALL WITH THE CLOUD COVER.
GENERALLY DRY CONDS ON TAP FOR THE OVERNIGHT PERIOD AS HIGH PRES
OVERHEAD MOVES OFFSHORE AFTER MIDNIGHT.
STORM SYSTEM DEVELOPING OVER THE OH VALLEY...AND SHORT TERM MODELS
INDICATING EITHER THE SYSTEM OR REMNANTS OF IT WILL APPROACH
WESTERN PORTIONS OF THE FORECAST AREA TOWARDS THE END OF THE
OVERNIGHT PERIOD. LATEST HRRR MODEL HAS ONE WAVE IMPACTING THE
AREA AFTER MIDNIGHT...THEN ANOTHER WAVE APPROACHING FOR AFTER
SUNRISE THURSDAY MORNING. 18Z NAM HAS THE COMPLEX ENTERING WESTERN
PORTIONS OF THE CWA BY 12Z THURSDAY. WILL CARRY SLIGHT CHANCE POPS
FOR ORANGE COUNTY LATE...AND WILL HOLD OFF ON REST OF POPS UNTIL
THE START OF THE SECOND PERIOD.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/...
WITH EITHER REMNANTS OF OR THE MCS ITSELF APPROACHING THURSDAY
MORNING...WILL GO AHEAD AND INCREASE POPS TO CHANCE STARTING
BETWEEN 10-12Z OVER WESTERN ZONES...THEN WILL SPREAD THOSE POPS
EAST THROUGH 15-17Z. THIS ACTIVITY WILL BE AHEAD OF A WARM FRONT
THAT MOVES NORTH THROUGH THE REGION IN THE MORNING...THEN THE CWA
BECOMES WARM SECTORED IN THE AFTERNOON. WITH LLJ APPROACHING IN
THE MORNING...WILL GO AHEAD AND MENTION GUSTY WINDS IN THE
FORECAST FOR THURSDAY MORNING.
OTHERWISE...AN INITIAL CAP OVER THE AREA IN THE EARLY AFT SHOULD
ERODE WITH A HIGHLY UNSTABLE AIR MASS IN PLACE. MU CAPES OF 2000
TO 3000 J/KG AND 35 TO 40 KT MID LEVEL WINDS WILL SET UP A
FAVORABLE ENVIRONMENT FOR SEVERE WX DURING THE LATE AFTERNOON AND
FIRST HALF OF THE EVENING. CONVERGENCE ALONG AND AHEAD OF THE PRE-
FRONTAL TROF WILL PROVIDE THE LOW-LEVEL FORCING WITH WEAK MID
LEVEL HEIGHT FALLS. THIS FAVORS THE DEVELOPMENT OF A SCATTERED TO
NUMEROUS THUNDERSTORMS. A UNIDIRECTIONAL WIND PROFILE SUPPORTS
MULTIPLE CLUSTERS AND BOWING SEGMENTS WITH THE PRIMARY THREAT
BEING DAMAGING WINDS. SOME WEAKENING OF THE CONVECTION IS EXPECTED
AS IT MOVES OUT ACROSS EASTERN LI AND SE CT. CONVECTION SHOULD
DIMINISH BY MIDNIGHT FROM WEST TO EAST.
AN HWO HAS BEEN UPDATED TO ADDRESS THE SEVERE WEATHER POTENTIAL.
SPC HAS PLACED MOST OF THE AREA UNDER A MODERATE RISK FOR THU AFT
AND EVE. ENHANCED WORDING ADDED TO THE FORECAST TO REFLECT THE
POTENTIAL THESE STORMS WILL HAVE.
PRIOR TO THE ONSET OF THE LATE DAY CONVECTION...A SURGE OF WARM
ALOFT WITH 85H TEMP NEAR 22C WILL ALLOW DAYTIME HIGHS AWAY FROM
THE COAST TO REACH INTO THE LOWER 90S...WITH THE LOW TO MID 80S
ALONG THE COAST. HEAT INDEX VALUES FOR NYC LOOK TO BE JUST BELOW
95.
A WARM...MUGGY NIGHT WILL BE ON TAP THU NIGHT WITH LOW IN THE
LOWER TO MID 70S WITH DEW POINTS AROUND 70. FRONTAL BOUNDARY LOOKS
TO REMAIN JUST NORTH OF THE AREA.
THERE IS A MODERATE RISK OF RIP CURRENTS THURSDAY
MORNING...BECOMING HIGH THURSDAY AFTERNOON THROUGH THURSDAY
EVENING AS WINDS INCREASE TO 15 TO 25 MPH AND SURF BUILDS TO 3 TO
5 FT.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
ACTIVE PERIOD TO START THE LONG TERM WITH A GRADUALLY AMPLIFYING
TROUGH WORKING FROM THE GREAT LAKES TO THE EAST COAST THROUGH
SATURDAY NIGHT. MEANWHILE AT THE SURFACE...A SLOW MOVING COLD
FRONT WITH MULTIPLE WEAK WAVES OF LOW PRESSURE WILL GRADUALLY
MOVES ACROSS AND THEN EAST OF THE REGION.
POTENTIAL FOR SCATTERED STRONG TO SEVERE CONVECTION EXISTS ON FRIDAY
AFTERNOON/EARLY EVENING AS THE COLD FRONT PUSHES THE VERY WARM AND
HUMID AIR MASS OFFSHORE...WITH AT LEAST MODERATE CAPE AND SHEAR. WITH
UNCERTAINTY ON CONVECTIVE DEBRIS...HAVE STAYED CLOSE TO MAV/MET
TEMPS. GENERALLY UPPER 80S/LOWER 90S AREA-WIDE...AND WITH DEWPOINT
POOLING AT LEAST IN THE LOWER 70S...HEAT INDICES IN THE MID TO UPPER
90S FOR MUSH OF THE REGION. MARGINAL HEAT ADVISORY POTENTIAL FOR
NYC/NJ METRO.
THEN SOME UNCERTAINTY FOR FRIDAY NIGHT THROUGH SATURDAY NIGHT IN HOW
FAR OFFSHORE THE COLD FRONT MOVES OFFSHORE AND TIMING OF WEAK WAVES
AND ASSOCIATED AREAS OF PRECIP ALONG THE FRONT. BUT OVERALL WITH
TROUGH AXIS APPROACHING AND FAVORABLE CAPE/SHEAR
ENVIRONMENT...POTENTIAL EXISTS FOR STRONG CONVECTION ACROSS AT LEAST
WESTERN SECTIONS OF THE REGION SAT AFTERNOON/EARLY EVENING.
MODELS IN DECENT AGREEMENT WITH TROUGH AXIS SLIDING EAST SATURDAY
NIGHT...BUT LIKELY GIVING WAY TO MEAN EAST COAST TROUGHING THROUGH
MIDWEEK. AT THE SURFACE BROAD BUT WEAK HIGH PRESSURE BUILDS IN FOR
SUN INTO MON AND THEN PUSHES OFFSHORE ON TUES. THE RESULT WILL NEAR
SEASONABLE CONDITIONS WITH WIDELY SCATTERED DIURNAL CONVECTION SUN
AND MON AFTERNOON.
INCREASING UNCERTAINTY IN DETAILS FOR TUE AND WED...BUT RETURN FLOW
SHOULD ALLOW FOR AN INCREASE IN HUMIDITY LEVELS AND POSSIBLY
INCREASED DIURNAL SHOWER/TSTM COVERAGE.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
HIGH PRESSURE WILL PASS TO THE SOUTH TONIGHT. A WARM FRONT WILL
APPROACH THU MORNING...AND PASS THROUGH LATE THU MORNING OR EARLY
THU AFTERNOON. A COLD FRONT WILL APPROACH TOWARD THU EVENING.
TSTMS DEVELOPING AHEAD OF THE WARM FRONT AS 0F 00Z OVER LOWER
MICHIGAN SHOULD EXPAND AND HEAD E-SE TOWARD THE AREA.
CURRENT THINKING IS THAT THESE STORMS SHOULD REACH KSWF BY 12Z-
13Z...NYC METRO BY 13Z-14Z...KBDR/KISP BY 14Z-15Z...AND KGON BY
15Z-16Z. CONFIDENCE AT LEAST HIGH ENOUGH TO ADDRESS VIA PROB30
GROUP AND TO MENTION MVFR VSBY AT KSWF/KHPN/KBDR.
WHILE WIDESPREAD TSTM IMPACTS FROM A LINE OF STRONG TO SEVER
TSTMS SHOULD BEGIN TOWARD THE VERY END OF THE 00Z TAF PERIOD...
SOME DISCRETE TSTMS ARE POSSIBLE BEFORE THAT BEGINNING ABOUT 20Z-
21Z. UNTIL THEN...WIND IMPACTS WILL BE THE GREATER CONCERN...AS SW
WINDS INCREASE QUICKLY AFTER ABOUT 12Z-13Z...WITH SPEEDS AROUND
15 KT WITH GUSTS 20-25 KT IF NOT BOTH A LITTLE HIGHER IN NYC
METRO.
OUTLOOK FOR 00Z FRI THROUGH MONDAY...
.THU EVENING...LINE OF SEVERE TSTMS WITH STRONG WINDS AND IFR
CONDS EXPECTED.
.LATER THU NIGHT THROUGH MON......OCNL IFR CONDITIONS ARE POSSIBLE
WITH LOW CLOUDS AND/OR SHOWERS/TSTMS.
&&
.MARINE...
WINDS AND SEAS FORECAST ON TRACK OVERNIGHT INTO THURSDAY.
TRANQUIL CONDS ON TAP FOR TONIGHT. TSTMS ARE POSSIBLE THURSDAY
MORNING FROM 10-15Z AS STORM SYSTEM APPROACHES FROM THE WEST.
SCA REMAINS UP FOR ALL WATERS FOR A STRENGTHENING SW FLOW THU AND
THU EVE AHEAD OF POTENT STORM SYSTEM WHICH PASSES TO THE NORTH THU
EVE. GUSTS UP TO 30 POSSIBLE ALONG WITH A LINE OF SEVERE
THUNDERSTORMS DURING THE LATE AFT/EVE HOURS.
SW FLOW EXPECTED TO GRADUALLY WEAKEN ON FRIDAY...BUT MARGINAL SCA
SEAS WILL LIKELY LINGER UNTIL THE COLD FRONT PASSES LATE
FRIDAY/FRIDAY EVENING.
ONCE OCEAN SEAS SUBSIDE...LATE FRIDAY/FRI NIGHT...SUB SCA CONDITIONS
EXPECTED IN A WEAK PRESSURE REGIME THROUGH EARLY NEXT WEEK.
&&
.HYDROLOGY...
NO SIGNIFICANT RAINFALL IS EXPECTED THROUGH TONIGHT.
PRECIPITABLE WATERS ARE FORECAST TO INCREASE TO AROUND 2 INCHES
BY THURSDAY AFTERNOON. AS THE RESULT LOCALLY HEAVY RAINFALL IS
POSSIBLE WITH ANY STRONGER CONVECTION...ESPECIALLY THURSDAY EVENING.
WITH A FORECAST STORM MOTION OF AROUND 20 KT...MINOR URBAN/POOR
DRAINAGE FLOODING IS THE MOST LIKELY THREAT. LOCALIZED FLASH
FLOODING CANNOT BE RULED OUT THOUGH...ESPECIALLY IF TRAINING
OCCURS. FOR NOW FORECASTING BASIN AVERAGE QPF AMOUNTS OF AROUND
1/4 TO 1/2 AN INCH WITH LOCALIZED AMOUNTS OF 1-2+ INCHES POSSIBLE.
MAIN THREAT APPEARS TO BE FOR LOCALLY HEAVY RAINFALL FROM DIURNAL
CONVECTION FRIDAY AND SATURDAY AFTERNOON.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 11 PM EDT THIS
EVENING FOR ANZ330-335-338-340-345.
SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 6 AM EDT
FRIDAY FOR ANZ350-353-355.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
154 AM EDT THU JUL 26 2012
.UPDATE...
WILL BE ISSUING A HEAT ADVISORY FOR MUCH OF MIDDLE AND EASTCENTRAL
GA FOR LATE THIS MORNING THROUGH MID EVENING. MORE DISCUSSION WILL
FOLLOW.
SNELSON
.PREV DISCUSSION... /ISSUED 948 PM EDT WED JUL 25 2012/
UPDATE...
ONLY A FEW SHOWERS LINGER AROUND THE CSG AREA AND WILL THEREFORE
REMOVE ALL POPS EXCEPT FOR CSG AREA AND TAKE OUT ALL THUNDER. NO
OTHER CHANGES PLANNED.
SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
/ISSUED AT 337 PM EDT WED JUL 25 2012/
MAIN FORECAST CONCERN IS HEAT TODAY AND THURSDAY ALONG WITH
CONVECTION DEVELOPMENT BOTH AFTERNOONS. CURRENT TEMPS HAVE BEEN
RIGHT ON TRACK WITH FORECAST AND AREAS IN THE SOUTH ARE IN LINE FOR
REACHING HEAT ADVISORY CRITERIA...THEREFORE WILL CONTINUE CURRENT
PRODUCT. GENERALLY WENT WITH BLEND OF MAV AND MET SOLUTIONS FOR
TEMPS INTO TOMORROW NIGHT. AREAS IN THE EAST CENTRAL AND SOUTHEAST
PORTIONS LOOK TO AGAIN REACH OVERNIGHT MIN TEMPS OF AT LEAST 75
DEGREES AND PEAK HEAT INDICES OF AT LEAST 105 DEGREES TOMORROW. FOR
850 MB TEMPS...THE GFS HAS SIMILAR VALUES TO SLIGHTLY WARMER FOR
THURSDAY AFTERNOON WHILE THE NAM GOES SLIGHTLY COOLER PARTICULARLY
IN THE SOUTHWEST PORTION. THIS IS LIKELY DUE TO A SLUG OF TROPICAL
MOISTURE AND ASSOCIATED CLOUD COVER PROGGED TO ADVECT NORTHWARD INTO
THE AREA FROM THE NE GULF COAST. ATTM IT APPEARS THAT EXTENDING THE
CURRENT HEAT ADVISORY INTO THURSDAY EARLY EVENING FOR THE EAST
CENTRAL AND SOUTHEAST PORTIONS WOULD BE REASONABLE WITH PERHAPS
TRIMMING OUT THE SOUTHWEST. THIS DECISION WILL BE BEST MADE LATER
THIS AFTERNOON INTO EARLY EVENING SO AS TO PREVENT CONFUSION WITH
CURRENT PRODUCT... THEREFORE PLEASE STAY TUNED TO FUTURE UPDATES.
THE OUTFLOW FROM MCS REMNANTS ACROSS THE CAROLINAS EARLIER TODAY HAS
SERVED MOSTLY TO STABILIZE THE ENVIRONMENT ACROSS THE EASTERN
PORTION OF THE AREA. THE SOUTHERN AND WESTERN PERIPHERIES OF THIS
FEATURE MAY FOCUS DEVELOPMENT LATER TODAY...HOWEVER THE HRRR DOES
NOT BUY INTO THIS MUCH AND JUST HAS THE MAIN DEVELOPMENT IN THE
SOUTHWEST. CURRENT VIS SATELLITE IMAGERY HAS SHOWN SOME CU FIELD
ENHANCEMENTS WITH THE ASSOCIATED OUTFLOW AND PERHAPS WEAK GRAVITY
WAVES... BUT EARLY SHOWER AND THUNDERSTORM DEVELOPMENT HAS BEEN
CLOSER TO THE SW PORTION OF THE AREA. HAVE THEREFORE GONE WITH
HIGHER CHANCE POPS IN THE SW TAPERING TO SLIGHT POPS IN THE NW.
MLCAPE VALUES OF 2500-3500 J/KG...WEAK VERTICAL WIND SHEAR...AND PW
VALUES OF 1.8-2.0 INCHES WILL ALLOW FOR THE MAIN STORM THREATS BEING
STRONG WINDS...HEAVY RAINFALL...FREQUENT LIGHTNING...AND SMALL HAIL.
ISOLATED SEVERE STORMS ARE POSSIBLE AS WELL... ESPECIALLY IN THE
SOUTHWEST WHERE SPC ALSO HAS A SLIGHT RISK ISSUED.
WITH THE UPPER RIDGE AXIS OVER THE GREAT LAKES PROGGED TO DAMPEN OUT
AND BREAK DOWN...THE ASSOCIATED NW FLOW ALOFT EXTENDING INTO THE
CAROLINAS SHOULD WEAKEN AND BECOME MORE ZONAL BY 12Z THURSDAY. THE
COMBINATION OF A WEAK LEE SFC TROUGH AND ENHANCED MOISTURE FROM THE
ADVECTION OF THE AFOREMENTIONED TROPICAL PLUME IN THE NE GULF WILL
ALLOW FOR THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS AGAIN IN THE
SOUTH ON THURSDAY. GUIDANCE IS IN GOOD AGREEMENT WITH A DEVELOPING
UPPER TROUGH APPROACHING THE NORTHERN PORTION OF THE AREA BY LATE
THURSDAY NIGHT...ALONG WITH AN ASSOCIATED SFC FRONT. THIS MAY
INCREASE PRECIP POTENTIAL IN THE NORTHERN PORTION THURSDAY NIGHT
INTO FRIDAY.
03
LONG TERM /FRIDAY THROUGH WEDNESDAY/...
/ISSUED AT 337 PM EDT WED JUL 25 2012/
HAVE MADE NO CHANGES TO THE LONG TERM. MODELS CONSISTED IN SHOWING
A FRONTAL BOUNDARY SINKING INTO THE CWA SATURDAY INTO SUNDAY.
NORTH GA MAY BE DRY SATURDAY NIGHT INTO SUNDAY NIGHT BUT MOISTURE
RETURNS BY THE FIRST OF THE WEEK.
41
PREVIOUS DISCUSSION/ISSUED 421 AM WED JUL 25 2012/
HIGH PRESSURE RIDGE OVER THE AREA WEAKENS AND SINKS SOUTH IN THE
SHORT TERM. BY FRI...THE RIDGE AXIS IS OVER FL AND THE GULF AND AN
APPROACHING COLD FRONT IS MOVING SOUTH OUT OF THE UPPER MS RIVER
VALLEY. THIS RIDGE STILL DOMINATES THE WEATHER PATTERN THROUGH THE
END OF THE WORK WEEK KEEPING NORTH AND CENTRAL GA IN MOIST WEST TO
SOUTHWESTERLY FLOW. PRECIPITABLE WATER VALUES STILL SHOWING NEAR
1.5 TO 1.8 INCH SO HEAVY RAIN WILL STILL BE A CONCERN...AT LEAST
THROUGH FRI. DIURNALLY DRIVEN THUNDERSTORMS WILL CONTINUE THROUGH
FRIDAY...BUT THEN THINGS BEGIN TO CHANGE SAT. A DEEP CLOSED LOW
CENTER TRACKS EAST ACROSS THE GREAT LAKES STATES AND INTO THE NEW
ENGLAND STATES THU...WITH ITS ASSOCIATED COLD FRONT MOVING
SOUTHWARD. THIS FRONT MOVES INTO NORTH GA BY 00Z SAT AND CONTINUES
MOVING SOUTHWARD INTO NORTH FL BY 12Z-18Z SUN. THIS FRONT BRINGS
IN A MUCH DRIER AIRMASS AND COOLER TEMPS FOR THE STATE SUN. HAVE
BACKED OFF ON POPS FOR SUN TO JUST ISOLATED TSRA MAINLY FOR
CENTRAL GA. MOISTURE DOES INCREASE AGAIN MON/TUE SO WILL KEEP
ISO/SCT SHRA/TSRA BACK IN THE FORECAST MON/TUE.
01
CLIMATE...
RECORDS FOR 07-26
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 103 2010 80 1904 76 2005 56 1911
1936
KATL 98 1901 78 1890 77 2005 59 1911
KCSG 99 2010 82 1954 79 1983 66 1948
KMCN 100 2010 80 1957 78 2005 60 1911
1993
&&
.AVIATION...
06Z UPDATE...
MAIN CONCERN TODAY WILL BE EXPECTED COVERAGE OF TSRA. SIMILAR
PATTERN TODAY AS YESTERDAY. EXPECT TSRA TO DEVELOP AROUND 19-20Z
OVER SRN GA AND DRIFT NORTH. BETTER CHC AGAIN IN MIDDLE AND
WESTCENTRAL GA THAN IN THE NORTH. COVERAGE OF TSRA AGAIN WILL
BE AROUND 30 PCT...WILL CONTINUE PROB30 AT ALL AIRPORTS BUT MAY
NEED TEMPO AT KCSG ADN POSSIBLY KMCN IF CONFIDENCE CONTINUES TO
INCREASE. NW WINDS WILL SHIFT TO SW AT MOST AIRPORTS AROUND
18-19Z. MAY SEE ONE OR TWO HOURS OF GUSTS TO AROUND 20KTS IN THE
AFTERNOON...ESP AT KATL.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE ON TSRA LIKELIHOOD.
HIGH CONFIDENCE ON ALL OTHER ELEMENTS.
SNELSON
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 98 74 98 73 / 20 20 30 20
ATLANTA 96 75 94 74 / 30 20 40 20
BLAIRSVILLE 91 69 90 68 / 20 20 50 40
CARTERSVILLE 96 73 94 69 / 20 20 50 30
COLUMBUS 95 75 93 76 / 40 30 40 20
GAINESVILLE 93 74 94 73 / 20 20 40 30
MACON 96 74 97 74 / 40 30 30 20
ROME 97 73 94 69 / 20 20 50 30
PEACHTREE CITY 95 73 94 70 / 30 20 40 20
VIDALIA 100 77 97 77 / 30 20 30 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SNELSON
LONG TERM....01
AVIATION...SNELSON
AREA FORECAST DISCUSSION
NWS LINCOLN IL
315 AM CDT THU JUL 26 2012
.DISCUSSION...
ISSUED 315 AM CDT THU JUL 26 2012
SERIES OF MCS SYSTEMS LINED UP FROM KANSAS TO LOWER MICHIGAN HAS
BEEN WEAKENING THE LAST COUPLE HOURS. HAVE MANAGED TO GET A FEW
STORMS FIRING IN THE ILLINOIS DESERT ALONG AN OUTFLOW BOUNDARY...
WHICH STRETCHED FROM PITTSFIELD TO PONTIAC AT 2 AM. SOME GUSTS TO
35-40 MPH OCCURRED ALONG THIS BOUNDARY...WITH HIGHER SPEEDS IN
NORTHERN ILLINOIS. HOWEVER...MUCH OF THE LARGER RAIN SHIELD HAS
BEEN DIMINISHING AS IT APPROACHES WEST CENTRAL ILLINOIS. THE
PRIMARY COLD FRONT EXTENDED FROM THE TEXAS PANHANDLE TO LOWER
MICHIGAN...WITH A SECONDARY BOUNDARY FROM NORTHWEST KANSAS TO THE
MINNESOTA ARROWHEAD.
SHORT TERM...TODAY THROUGH SATURDAY...
PRIMARY FORECAST CONCERN DURING THIS PERIOD INVOLVES CONVECTIVE
REDEVELOPMENT TODAY. LATEST HRRR MODEL SHOWS A WEAKENING TREND
CONTINUING WITH THE EXISTING CONVECTION AS IT MOVES THROUGH
ILLINOIS. ADDITIONAL DEVELOPMENT SHOULD START FIRING TOWARD MIDDAY
AS THE MAIN COLD FRONT APPROACHES SOUTHEAST ILLINOIS TOWARD EARLY
AFTERNOON. ENTIRE CWA IS UNDER A SLIGHT RISK OF SEVERE WEATHER FOR
TODAY...HOWEVER THE BETTER CHANCES WILL BE CLOSER TO THE I-70
CORRIDOR AHEAD OF THE FRONT...WHERE THE ATMOSPHERE WILL BE LESS
OVERTURNED BY THE EARLY MORNING CONVECTION. LATEST NAM MODEL
PROJECTS 3000 J/KG OF CAPE IN THIS AREA BY THE TIME THE FRONT
ARRIVES. MOST OF THE RAIN SHOULD BE OUT OF THE AREA BY EARLY
EVENING...BUT WILL LINGER SOME SMALL POPS EAST OF I-57 INTO
EVENING. SOME ADDITIONAL SHOWERS AND STORMS WILL OCCUR OVER
PORTIONS OF THE MIDWEST FRIDAY...AS THE UPPER TROUGH SWINGS
THROUGH THE GREAT LAKES...BUT THESE WILL LIKELY REMAIN JUST TO OUR
NORTH.
TEMPERATURES TODAY WILL BE TRICKY...WITH THE RAIN AND CLOUD COVER.
AREAS SOUTHEAST OF I-70 WILL BE MOST LIKELY TO SEE HEAT INDEX
VALUES NEAR ADVISORY CRITERIA NEAR 105. WILL GO AHEAD AND ISSUE
AN ADVISORY IN THAT AREA FOR THIS AFTERNOON AND EARLY EVENING.
FOR FRIDAY...STILL AM EXPECTING TEMPERATURES INTO THE MID TO UPPER
90S IN THE SOUTHEAST CWA...BUT DRIER AIR IN THE NORTHWEST FLOW
SHOULD KEEP HEAT INDEX VALUES IN CHECK. HIGHS BY SATURDAY SHOULD
MAINLY BE IN THE 80S OVER THE ENTIRE FORECAST AREA.
LONG TERM...SUNDAY THROUGH WEDNESDAY...
UPPER RIDGING WILL PLACE ILLINOIS IN THE NORTHWEST FLOW COMING
DOWN THE TOP OF THE RIDGE THROUGH THE PERIOD. PERIODIC SHORTWAVES
IN THE FLOW WILL LEAD TO RAIN CHANCES AT TIMES...WITH SUNDAY NIGHT
THROUGH MONDAY THE BEST BET AT THE MOMENT. TEMPERATURES WILL BEGIN
TO CREEP BACK UPWARD EARLY NEXT WEEK...WITH HIGHS MAINLY IN THE
LOWER 90S.
GEELHART
&&
.AVIATION...
ISSUED 1157 PM CDT WED JUL 25 2012
BELIEVE VFR CONDITIONS WILL CONTINUE AT ALL TAF SITES NEXT 24HRS.
AREA OF SHOWERS AND THUNDERSTORMS IS MOVING INTO THE STATE FROM
THE WEST BUT CLOUD LEVELS ARE QUITE HIGH SO WILL HAVE SCT SC WITH
BKN AC ONCE PCPN ARRIVES. QUESTION IS...WILL PCPN GET HERE. NOT
VERY CONFIDENT THAT PCPN WILL REACH ALL SITES GIVEN THE OUTFLOW
BOUNDARIES THAT HAVE ALREADY GUSTED OUT AHEAD OF THE STORMS IN
EASTERN IOWA AND WEST CENTRAL MO. ONLY PLACE WHERE OUTFLOW
BOUNDARY IS WITH STORM IS NERN MO. BELIEVE THIS AREA OF STORMS
WILL BE MOVING ENE TOWARD PIA SO WILL HAVE VCTS AT PIA AT 09Z ONLY
AND VCSH AT ALL OTHER SITES DURING THE MORNING HOURS...10Z-12Z.
LOOKS LIKE PCPN WILL LAST ABOUT 3HRS AT EACH SITE WITH AC BEHIND
THE PCPN. FRONT SHOULD ALSO MOVE THROUGH AROUND SAME TIME. BELIEVE
FRONT WILL BE SOUTH OF SPI/DEC/CMI BY MAX HEATING TIME SO VERY
UNCERTAIN IF THEY WILL SEE ANY PCPN DURING THE AFTERNOON HOURS SO
AM LEAVING IT OUT FOR NOW. OVERNIGHT SHIFT CAN TAKE ANOTHER LOOK
OVERNIGHT ONCE MESOSCALE FEATURES ARE BETTER KNOWN. BKN AC WILL
CONTINUE INTO THE AFTERNOON BUT APPEARS AS THIS IS MOVING OUT AREA
OF CLOUDS AROUND 6KFT WILL MOVE IN BEHIND THE FRONT FOR THE LATE
AFTERNOON AND EVENING HOURS. WINDS WILL BE SOUTHWEST AHEAD OF THE
FRONT THEN BECOME NORTHWEST BEHIND THE PCPN/FRONT...THEN WESTERLY
DURING THE LATE MORNING TO EVENING HOURS.
AUTEN
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR
ILZ062-063-066>068-071>073.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS DES MOINES IA
1155 PM CDT WED JUL 25 2012
.UPDATED FOR 26/06Z AVIATION DISCUSSION...
.SHORT TERM /TONIGHT/...
MAIN FORECAST CONCERN IS WITH TIMING OF COLD FRONT AND CONVECTION
POTENTIAL THIS EVENING INTO THE OVERNIGHT HOURS. NAM/RAP SEEM TO
HAVE A DECENT HANDLE ON INITIATION OF CONVECTION AND LEANED TOWARD
TIMING OF FRONT/POPS. THE 16Z HRRR HAS SOME ISOLATED CONVECTION
DEVELOPING B/T 22-00Z BUT THINKING CAP IS STILL TOO STRONG FOR MUCH
CONVECTION TO GET GOING UNTIL AFTER 00Z. REALLY CUT BACK ON POPS
UNTIL AFTER 00Z OVER THE CENTRAL AND SOUTHEAST CWA. THE 12Z 4.0KM
WRF MODEL RUNS FROM NSSL AND NCEP BOTH HAVE VERY SPOTTY PRECIP
THROUGH TONIGHT...AND SORT OF LIGHTS UP THE FRONT SOUTH OF
INTERSTATE 80 AFTER 02Z THURSDAY. HAVE LOW CONFIDENCE WITH ANY
WIDESPREAD SIGNIFICANT CONVECTION TONIGHT. MODELS FORECASTING PW
VALUES NEAR 2 INCHES GENERALLY ALONG THE FRONT...AND 1-1.5 INCHES
BEHIND IT. HOWEVER...WITH SUCH SPOTTY CONVECTION AND LOWERED QPF
AMOUNTS TO LESS THAN A HALF INCH THROUGHOUT THE FORECAST
AREA...ESPECIALLY WITH SUCH HIGH BASED CONVECTION. PLENTY OF SURFACE
BASED INSTABILITY...BUT LITTLE IF ANY EFFECTIVE SHEAR AVAILABLE...AS
WELL AS FORCING OTHER THAN THE FRONTAL BOUNDARY TONIGHT. THINKING
MAIN SEVERE THREAT WILL BE WINDS WITH THE DRY AIRMASS PRESENT.
.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
LARGE SCALE MAINLY POST FRONTAL FORCING SHOULD BE JUST EXITING
FORECAST AREA BY THE START OF THE PERIOD SO ANY LINGERING
PRECIP...IF ANY...SHOULD BE MOVING INTO MO AND IL. FORECAST DRY
AFTER 15Z. PREVIOUS FORECAST HAD LOW POPS BRUSHING NERN IA BY LATE
AFTERNOON BUT CANNOT REALLY FIND ANY SUPPORT FOR THIS WITH LIMITED
FORCING AND INSUFFICIENT MOISTURE...AND EVEN THAT LOOKS TO BE POST
00Z. UPSTREAM NRN PLAINS AIRMASS WILL GRADUALLY PASS THROUGH IA
DURING THE DAY BUT DEEP NW FLOW AND MIXING WILL STILL ALLOW
CENTRAL/SRN HIGHS TO REACH LOW/MID 90S BY AFTERNOON. DO NOT
ANTICIPATED ENOUGH PRECIP TONIGHT TO AFFECT THAT. BLEND OF SREF/NAM
SOUNDINGS SEEMS REASONABLE.
NRN PLAINS SURFACE RIDGE WILL RETURN IA TEMPS TO NORMAL FOR FRI WITH
CONTINUED DRY WEATHER AS GREAT LAKES SHORT WAVE DEPARTS. THIS WILL
BE FOLLOWED BY AN EXTENDED PERIOD OF ROCKIES AND HIGH PLAINS
RIDGING...RIGHT INTO WED AND BEYOND...LEAVING IA WITH WARM BUT NOT
EXTREME TEMPS AND LOW END PRECIP POTENTIAL. CHANCES INCREASE
SOMEWHAT THIS WEEKEND AS SHORT WAVE TOPS THE RIDGE INCREASING
FORCING...ESPECIALLY THERMODYNAMIC...BY SAT. THIS WEAK FORCING
LINGERS INTO SUN...AND POSSIBLY EARLY MON LEADING TO SEVERAL DAYS
WORTH OF CHANCE POPS. MODELS CONTINUE TO DABBLE IN WEAK QPF EVENTS
AFTER THIS TIME...BUT THERE IS REALLY NO CONSISTENT FORCING FEATURE
TO LATCH ONTO SO HAVE LEFT MON NIGHT-WED DRY AT THIS POINT.
REGARDING TEMPS..ONLY REAL CONCERN IS LOW CONFIDENCE FORECAST
SATURDAY. QUESTIONS ON HOW MUCH WE WILL MIX IN NEW REGIME WITH
LIGHT WINDS. HAVE PRETTY MUCH MIXED THINGS OUT TO 900-850MB OR
MORE...MIXING SEASONALLY...BUT FEEL NAM IS UNDERDONE WHICH SEEMS TO
BE THE CASE AT TIMES IN WEAK FLOW.
&&
.AVIATION...26/00Z
MAIN FRONT HAS PUSHED THROUGH CENTRAL IOWA BUT INSTABILITY AND WEAK
SHEAR BEHIND THE BOUNDARY HAVE BEEN KEEPING THE STORMS GOING.
STORMS WILL BE IN THE KALO/KDSM AND KOTM TAFS THROUGH 09Z. A
SECONDARY BOUNDARY SHIFTS ACROSS THE FORECAST AREA DURING THE DAY
BUT THERE IS NO UPPER LEVEL SUPPORT WITH THIS SO EXCEPT FOR SOME
CLOUDS AND A SECOND SHOT OF NW WINDS AT 10-20KTS THAT SHOULD BE THE
ONLY SENSIBLE WEATHER. VFR CONDITIONS EXPECTED.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...SMALL
AVIATION...FAB
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
238 AM CDT THU JUL 26 2012
.SYNOPSIS...
ISSUED AT 1208 AM CDT THU JUL 26 2012
AT 00Z THURSDAY A -14C 500MB UPPER LOW WAS LOCATED NEAR SOUTHERN
MANITOBA AND A 500MB UPPER RIDGE WAS PLACED ACROSS THE SOUTHWEST
UNITED STATES. AT THE 250MB LEVEL A 75KT JET WAS MOVING OVER THE
UPPER RIDGE AXIS WITH THE NOSE OF THIS UPPER JET LOCATED NEAR
EASTERN WYOMING. ALSO ACROSS EASTERN WYOMING AND WESTERN NEBRASKA
AT 00Z THURSDAY WAS A 500MB THERMAL TROUGH. A 700MB BAROCLINIC
ZONE STRETCHED FROM EASTERN NEBRASKA IN TO NORTHEAST COLORADO. A
850MB COLD FRONT EXTENDED FROM SOUTHEAST NEBRASKA INTO NORTHWEST
KANSAS/EASTERN COLORADO. AT THE SURFACE A COLD FRONT APPEARS TO BE
LOCATED ACROSS NORTH CENTRAL AND SOUTHWEST KANSAS WITH MULTIPLE
OUTFLOW BOUNDARIES ALSO PRESENT FROM THE ONGOING CONVECTION.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 133 AM CDT THU JUL 26 2012
CONVECTION EARLIER THIS MORNING APPEARS TO HAVE RELATED WELL WITH AN
AREA OF 850-700MB FRONTOGENESIS OCCURRING AHEAD OF A 500MB TROUGH.
LATEST RAP AND NAM WERE IN DECENT AGREEMENT AND PLACES THIS ARE OF
BETTER FORCING EAST/SOUTHEAST OF DODGE CITY BETWEEN 09Z AND 12Z
THURSDAY. WILL CONTINUE TO MONITOR RADAR TREND BUT AT THIS TIME
THIS AREA OF CONVECTION SHOULD BE EXITING SOUTH CENTRAL KANSAS
AROUND 12Z.
MORNING CLOUD COVER WILL GIVE WAY TO CLEARING SKIES AS THE UPPER
TROUGH MOVES INTO CENTRAL KANSAS. 850MB TEMPERATURES DO INDICATED
A COOLING TREND TODAY AND BY 00Z FRIDAY THE 850MB TEMPERATURES ARE
FORECAST TO RANGE FROM 23-25C IN CENTRAL KANSAS TO THE UPPER 20S TO
NEAR 30C NEAR THE COLORADO BORDER. GIVEN THESE TEMPERATURES ALONG
WITH THE OVERNIGHT RAINFALL AND A EAST/NORTHEASTERLY FLOW IN THE
LOWER LEVELS WILL TREND TOWARDS KEEPING TEMPERATURES CLOSER TO THE
PREVIOUS FORECAST WHICH WERE COOLER THAN THE NAM 2M TEMPERATURES
BUT NOT AS COOL AS THE GFS.
TONIGHT AN UPPER LEVEL RIDGE AXIS WILL BUILD EAST INTO THE
ROCKIES AS SUBTLE UPPER LEVEL DISTURBANCE ROTATES OUT INTO THE
PLAINS. BASED ON MODEL SOUNDINGS MOISTURE AND INSTABILITY WILL
CONTINUE WITH A DRY FORECAST. LOWS BOTTOMING OUT IN THE MID 60S TO
AROUND 70S STILL APPEARS TO BE ON TRACK.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 236 AM CDT THU JUL 26 2012
UPPER LEVEL RIDGING WILL BE THE DOMINANT FEATURE ON FRIDAY. A
NORTHWESTERLY JET STREAK WILL BE OVER THE NORTHERN PLAINS, WITH WEAK
SURFACE HIGH PRESSURE ACROSS THE UPPER MIDWEST. RELATIVE HUMIDITY
FIELDS FROM THE GFS AND ECMWF INDICATE THE PRESENCE OF MID LEVEL
MOISTURE. HOWEVER THE LOW LEVELS ARE LIKELY TO BE MUCH DRIER, AND
TEMPERATURES WILL QUICKLY RISE INTO THE UPPER 90S BY EARLY
AFTERNOON. THE WEAK SURFACE PRESSURE PATTERN FEATURING A NORTHERN
HIGH PLAINS TROUGH WILL CONTRIBUTE TO DEVELOPMENT OF LIGHT SOUTHEAST
SURFACE WINDS FRIDAY.
MOVING FARTHER INTO THE WEEKEND, THE UPPER RIDGE BEGINS TO DRIFT
SLIGHTLY FARTHER SOUTHEAST, AND THE UPPER JET SEGMENTS THAT WERE
PREVIOUSLY STREAKING THROUGH THE NORTHERN PLAINS BECOME SHIFTED
CLOSER TO THE CENTRAL PLAINS. DURING THE LATE WEEKEND INTO EARLY
NEXT WEEK, A CONDITIONALLY UNSTABLE AIRMASS WILL BE IN PLACE, WITH
THE POTENTIAL FOR LATE DAY SURFACE BASED CONVECTION ALONG WEAK
SURFACE CONVERGENCE ZONES. SUBTLE SHORTWAVE ENERGY COULD ALSO COME
INTO PLAY AND ENHANCE LIFT FOR ELEVATED CONVECTION INTO THE LATER
HOURS THROUGH ABOUT TUESDAY EVENING.
ASSOCIATED WITH THE PERSISTENT UPPER RIDGING THROUGH THE CENTRAL AND
SOUTHERN PLAINS, TEMPERATURES WILL REMAIN VERY WARM IN THE UPPER 90S
TO AROUND 100 DEGREES FOR DAILY HIGHS. ADDED TO THIS WILL BE SOME
UNCERTAINTY IN VARIABILITY IF ANY PERIODS OF ENHANCED CLOUDINESS OR
EARLY AFTERNOON THUNDERSTORMS DEVELOP, AUGMENTING LOCAL TEMPERATURES.
OVERNIGHT LOWS SHOULD REMAIN MILD AS WELL, GENERALLY IN THE UPPER
60S, THROUGH THE 70S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1208 AM CDT THU JUL 26 2012
CONVECTION OCCURRING ACROSS SOUTHWEST AND NORTH CENTRAL KANSAS
WILL MOVE OUT OF THE DDC AND HYS TAF SITES BY 07Z BASED ON LATEST
RADAR TRENDS AND THE MOVEMENT OF AN AREA OF 850-700MB
FRONTOGENESIS AHEAD OF A 500MB TROUGH BASED ON THE LATEST RAPS.
BUFR SOUNDINGS SUGGESTING SKIES WILL CLEAR THROUGH THE EARLY MORNING
HOURS WITH VFR CONDITIONS EXPECTED THOUGH OUT THE PERIOD. VARIABLE
WINDS DUE TO THE SEVERAL OUTFLOW BOUNDARIES LOCATED ACROSS WESTERN
KANSAS WILL BECOME PRIMARILY FROM THE NORTHEAST BY 09Z AS A COLD
FRONT MOVES SOUTHEAST INTO NORTHWEST OKLAHOMA AND SOUTH CENTRAL
KANSAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 95 67 101 71 / 0 10 10 10
GCK 95 66 100 70 / 0 10 10 10
EHA 94 67 98 69 / 0 10 10 10
LBL 96 67 100 70 / 0 10 10 10
HYS 97 66 101 71 / 10 10 10 10
P28 97 70 103 73 / 10 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...RUSSELL
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
145 AM CDT THU JUL 26 2012
...UPDATED SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 1208 AM CDT THU JUL 26 2012
AT 00Z THURSDAY A -14C 500MB UPPER LOW WAS LOCATED NEAR SOUTHERN
MANITOBA AND A 500MB UPPER RIDGE WAS PLACED ACROSS THE SOUTHWEST
UNITED STATES. AT THE 250MB LEVEL A 75KT JET WAS MOVING OVER THE
UPPER RIDGE AXIS WITH THE NOSE OF THIS UPPER JET LOCATED NEAR
EASTERN WYOMING. ALSO ACROSS EASTERN WYOMING AND WESTERN NEBRASKA
AT 00Z THURSDAY WAS A 500MB THERMAL TROUGH. A 700MB BAROCLINIC
ZONE STRETCHED FROM EASTERN NEBRASKA IN TO NORTHEAST COLORADO. A
850MB COLD FRONT EXTENDED FROM SOUTHEAST NEBRASKA INTO NORTHWEST
KANSAS/EASTERN COLORADO. AT THE SURFACE A COLD FRONT APPEARS TO BE
LOCATED ACROSS NORTH CENTRAL AND SOUTHWEST KANSAS WITH MULTIPLE
OUTFLOW BOUNDARIES ALSO PRESENT FROM THE ONGOING CONVECTION.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 133 AM CDT THU JUL 26 2012
CONVECTION EARLIER THIS MORNING APPEARS TO HAVE RELATED WELL WITH AN
AREA OF 850-700MB FRONTOGENESIS OCCURRING AHEAD OF A 500MB TROUGH.
LATEST RAP AND NAM WERE IN DECENT AGREEMENT AND PLACES THIS ARE OF
BETTER FORCING EAST/SOUTHEAST OF DODGE CITY BETWEEN 09Z AND 12Z
THURSDAY. WILL CONTINUE TO MONITOR RADAR TREND BUT AT THIS TIME
THIS AREA OF CONVECTION SHOULD BE EXITING SOUTH CENTRAL KANSAS
AROUND 12Z.
MORNING CLOUD COVER WILL GIVE WAY TO CLEARING SKIES AS THE UPPER
TROUGH MOVES INTO CENTRAL KANSAS. 850MB TEMPERATURES DO INDICATED
A COOLING TREND TODAY AND BY 00Z FRIDAY THE 850MB TEMPERATURES ARE
FORECAST TO RANGE FROM 23-25C IN CENTRAL KANSAS TO THE UPPER 20S TO
NEAR 30C NEAR THE COLORADO BORDER. GIVEN THESE TEMPERATURES ALONG
WITH THE OVERNIGHT RAINFALL AND A EAST/NORTHEASTERLY FLOW IN THE
LOWER LEVELS WILL TREND TOWARDS KEEPING TEMPERATURES CLOSER TO THE
PREVIOUS FORECAST WHICH WERE COOLER THAN THE NAM 2M TEMPERATURES
BUT NOT AS COOL AS THE GFS.
TONIGHT AN UPPER LEVEL RIDGE AXIS WILL BUILD EAST INTO THE
ROCKIES AS SUBTLE UPPER LEVEL DISTURBANCE ROTATES OUT INTO THE
PLAINS. BASED ON MODEL SOUNDINGS MOISTURE AND INSTABILITY WILL
CONTINUE WITH A DRY FORECAST. LOWS BOTTOMING OUT IN THE MID 60S TO
AROUND 70S STILL APPEARS TO BE ON TRACK.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 344 PM CDT WED JUL 25 2012
THE ECMWF, GFS AND GFS ENSEMBLES ARE IN FAIRLY GOOD AGREEMENT WITH
THE LARGE SCALE UPPER-LEVEL PATTERN OVER THE NEXT WEEK. UPPER LEVEL
RIDGING WILL EDGE EASTWARD ACROSS THE HIGH PLAINS FROM THURSDAY INTO
SATURDAY. LOW LEVEL CONVERGENCE BOUNDARIES WILL BE LACKING SO THAT
PRECIPITATION CHANCES ARE LOW. TEMPERATURES SHOULD REMAIN RATHER
HOT AROUND 100F. UPPER LEVEL RIDGING WILL BUILD ACROSS OKLAHOMA
FROM SUNDAY INTO TUESDAY. VERY HOT AIR WILL BE SITUATED ALONG AND
JUST NORTH OF THE UPPER LEVEL RIDGE AXIS, WITH HIGHS FROM 100 TO
110F. THE ECMWF SHOWS A WEAK FRONTAL BOUNDARY SITUATED ALONG THE
NORTHERN PERIPHERY OF THE UPPER RIDGE, WITH COOLER TEMPERATURES TO
THE NORTH AND BLAZING HOT TEMPERATURES TO THE SOUTH. IT CURRENTLY
APPEARS THAT THE VERY HOT TEMPERATURES MAY BE CONFINED TO SOUTH
CENTRAL AND PARTS OF SOUTHWEST KANSAS, WITH THE COOLER READINGS TO
THE NORTH. ISOLATED THUNDERSTORM CHANCES CANNOT BE RULED OUT ANY
DAY IN THIS PERIOD GIVEN THAT WESTERN KANSAS WILL BE SITUATED
ALONG THE EDGE OF THE WESTERLIES WHERE WEAK SURFACE BOUNDARIES
OFTEN RESIDE IN SUMMER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1208 AM CDT THU JUL 26 2012
CONVECTION OCCURRING ACROSS SOUTHWEST AND NORTH CENTRAL KANSAS
WILL MOVE OUT OF THE DDC AND HYS TAF SITES BY 07Z BASED ON LATEST
RADAR TRENDS AND THE MOVEMENT OF AN AREA OF 850-700MB
FRONTOGENESIS AHEAD OF A 500MB TROUGH BASED ON THE LATEST RAPS.
BUFR SOUNDINGS SUGGESTING SKIES WILL CLEAR THROUGH THE EARLY MORNING
HOURS WITH VFR CONDITIONS EXPECTED THOUGH OUT THE PERIOD. VARIABLE
WINDS DUE TO THE SEVERAL OUTFLOW BOUNDARIES LOCATED ACROSS WESTERN
KANSAS WILL BECOME PRIMARILY FROM THE NORTHEAST BY 09Z AS A COLD
FRONT MOVES SOUTHEAST INTO NORTHWEST OKLAHOMA AND SOUTH CENTRAL
KANSAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 95 67 101 71 / 0 10 10 10
GCK 95 66 100 70 / 0 10 10 10
EHA 94 67 98 69 / 0 10 10 10
LBL 96 67 100 70 / 0 10 10 10
HYS 97 66 101 71 / 10 10 10 10
P28 97 70 103 73 / 10 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...FINCH
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1109 PM MDT WED JUL 25 2012
.UPDATE...
ISSUED AT 1036 PM MDT WED JUL 25 2012
SHOWERS AND THUNDERSTORMS CONTINUE TO DEVELOP OVER THE NORTON AND
HILL CITY AREA THIS EVENING. AM EXPECTING THE ACTIVITY TO MOVE
EAST IN THE NEXT HOUR OR SO AS THE LIFT BEHIND THE COLD FRONT FROM
AN UPPER LEVEL SHORT WAVE TROUGH MOVES SOUTHEAST.
FOR THURSDAY TEMPERATURES WILL CONTINUE TO BE COOLER THAN WHAT WE
HAVE HAD...WITH HIGHS ONLY IN THE 90S. A FEW ISOLATED
THUNDERSTORMS MAY DEVELOP DURING THE LATE AFTERNOON OVER YUMA AND KIT
CARSON COUNTIES AS SURFACE CONVERGENCE DEVELOPS UNDERNEATH A SHORT
WAVE TROUGH ROUNDING THE UPPER LEVEL RIDGE. ANY STORM ACTIVITY MAY
PUSH EAST INTO PARTS OF SOUTHWEST NEBRASKA AND NORTHWEST KANSAS.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH TONIGHT)
ISSUED AT 1241 PM MDT WED JUL 25 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW SHORTWAVE TROUGH AXIS
CURRENTLY EXTENDING ACROSS NEBRASKA PANHANDLE SOUTH ALONG KS/CO
STATE LINE...AND THEN ACROSS OK/TX PANHANDLE. WV IMAGERY SHOWS
PLUME OF MID LEVEL MOISTURE EXTENDING NORTH ON LEE SIDE OF ROCKIES
ALONG WESTERN EDGE OF TROUGH AXIS. ANOTHER SHORTWAVE TROUGH IS
CURRENTLY OVER CENTRAL WY AND SHOULD MOVE EAST INTO NEBRASKA BY
THIS EVENING. AT THE SURFACE THE COLD FRONT HAS STALLED JUST
SOUTHEAST OF OUR CWA. CLOUD COVER AND CONVECTION HAVE BEEN SLOW TO
DEVELOP MUCH FURTHER SOUTH THAN THE EXTREME NW PART OF CWA.
AS THE SHORTWAVE OVER CENTRAL WY MOVES EAST GUIDANCE CONTINUES TO
SHOW LARGE SCALE ASCENT INCREASING ACROSS THE EASTERN HALF OF THE
CWA IN PROXIMITY OF FRONT. AT THIS TIME LATEST HRRR AND RUC WOULD
SUPPORT SCATTERED THUNDERSTORMS FORMING GENERALLY EAST OF GOODLAND
AND THEN INCREASING IN COVERAGE THROUGH 00Z AS THEY MOVE
EASTWARD...QUICKLY ENDING OVER OUR CWA THIS EVENING. NAM CONTINUES
TO SHOW ISOLATED ACTIVITY FURTHER WEST ASSOCIATED WITH ELEVATED
CAPE AND H7 FRONTOGENESIS THROUGH THE OVERNIGHT PERIOD. CONFIDENCE
IS STILL TOO LOW TO INCLUDE ANY THUNDERSTORMS BEYOND THIS EVENING
WITH LARGE SCALE SUBSIDENCE AND SURFACE HIGH PRESSURE QUICKLY
BUILDING OVER THE CWA. I LEFT PATCHY FOG MENTION IN FORECAST OVER
EASTERN LOCATIONS...WITH CLAM WINDS AND STABLE AIR MASS SUPPORTING
RADIATIVE FOG DEVELOPMENT. GUIDANCE REALLY HAS NOT PICKED UP ON THIS
YET...SO I HAVE LEFT FOG COVERAGE LIMITED TO PATCHY.
.LONG TERM...(THURSDAY THROUGH WEDNESDAY)
ISSUED AT 246 PM MDT WED JUL 25 2012
HIGH PRESSURE MOVES INTO THE PLAINS STATES AT THE SURFACE THURSDAY
AND FRIDAY AS THE UPPER RIDGE AMPLIFIES OVER THE INTERMOUNTAIN
WEST AND MOVES EAST OVER THE ROCKIES. PRECIPITATION CHANCES ARE
MINIMAL ON THURSDAY AND THURSDAY NIGHT AS A RESULT. BY FRIDAY
EVENING THE SURFACE HIGH MOVES FAR ENOUGH TO THE EAST WITH A LEE
TROUGH DEEPENING IN THE VICINITY OF THE FAR EASTERN COLORADO
BORDER TO FORM A CONVERGENCE AREA OVER THE WESTERN PORTION OF THE
FORECAST AREA AS A SHORT WAVE TROUGH IN THE UPPER LEVEL FLOW MOVES
OVER THROUGH THE TOP OF THE RIDGE AND CLIPS THE NORTHERN SECTIONS
OF THE FORECAST AREA FRIDAY NIGHT. THIS SETUP WILL BRING A BETTER
CHANCE OF THUNDERSTORMS FRIDAY AFTERNOON AND EVENING. SEVERAL
ADDITIONAL SHORT WAVE TROUGHS MAKE THEIR WAY AROUND THE UPPER
RIDGE AND CLIP THE FORECAST AREA FROM SATURDAY THROUGH TUESDAY.
WITH A SURFACE TROUGH ALSO REMAINING OVER MAINLY THE WESTERN
PORTION OF THE FORECAST AREA DURING THIS TIME...THEREFORE EXPECT
TEMPERATURES TO REMAIN VERY WARM WITH ADDITIONAL DIURNALLY DRIVEN
ISOLATED TO SCATTERED THUNDERSTORMS MAINLY OVER THE WESTERN
PORTIONS OF THE FORECAST AREA. BY THE MIDDLE OF NEXT
WEEK...CURRENT INDICATIONS ARE THAT THE UPPER RIDGE WILL AMPLIFY
FURTHER AND MOVE MORE OVER THE PLAINS STATES...SENDING THE SHORT
WAVE IMPULSES FURTHER NORTH THROUGH THE NORTHERN PLAINS AND
POSSIBLY DECREASING THE POSSIBILITY OF PRECIPITATION ACROSS THE
CENTRAL HIGH PLAINS REGION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1109 PM MDT WED JUL 25 2012
VFR CONDITIONS ARE FORECAST FOR THE 6Z TAFS. WINDS WILL REMAIN
LIGHT THROUGH THE PERIOD AS THE UPPER LEVEL HIGH PRESSURE
STRENGTHENS OVER THE TRI-STATE AREA. WITH MOISTURE...LIFT AND
INSTABILITY REMAINING WELL WEST OF THE TAF SITES...AM NOT
EXPECTING ANY THUNDERSTORMS TO MOVE NEAR THE SITES.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...LOCKHART
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1044 PM MDT WED JUL 25 2012
.UPDATE...
ISSUED AT 1036 PM MDT WED JUL 25 2012
SHOWERS AND THUNDERSTORMS CONTINUE TO DEVELOP OVER THE NORTON AND
HILL CITY AREA THIS EVENING. AM EXPECTING THE ACTIVITY TO MOVE
EAST IN THE NEXT HOUR OR SO AS THE LIFT BEHIND THE COLD FRONT FROM
AN UPPER LEVEL SHORT WAVE TROUGH MOVES SOUTHEAST.
FOR THURSDAY TEMPERATURES WILL CONTINUE TO BE COOLER THAN WHAT WE
HAVE HAD...WITH HIGHS ONLY IN THE 90S. A FEW ISOLATED
THUNDERSTORMS MAY DEVELOP DURING THE LATE AFTERNOON OVER YUMA AND KIT
CARSON COUNTIES AS SURFACE CONVERGENCE DEVELOPS UNDERNEATH A SHORT
WAVE TROUGH ROUNDING THE UPPER LEVEL RIDGE. ANY STORM ACTIVITY MAY
PUSH EAST INTO PARTS OF SOUTHWEST NEBRASKA AND NORTHWEST KANSAS.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH TONIGHT)
ISSUED AT 1241 PM MDT WED JUL 25 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW SHORTWAVE TROUGH AXIS
CURRENTLY EXTENDING ACROSS NEBRASKA PANHANDLE SOUTH ALONG KS/CO
STATE LINE...AND THEN ACROSS OK/TX PANHANDLE. WV IMAGERY SHOWS
PLUME OF MID LEVEL MOISTURE EXTENDING NORTH ON LEE SIDE OF ROCKIES
ALONG WESTERN EDGE OF TROUGH AXIS. ANOTHER SHORTWAVE TROUGH IS
CURRENTLY OVER CENTRAL WY AND SHOULD MOVE EAST INTO NEBRASKA BY
THIS EVENING. AT THE SURFACE THE COLD FRONT HAS STALLED JUST
SOUTHEAST OF OUR CWA. CLOUD COVER AND CONVECTION HAVE BEEN SLOW TO
DEVELOP MUCH FURTHER SOUTH THAN THE EXTREME NW PART OF CWA.
AS THE SHORTWAVE OVER CENTRAL WY MOVES EAST GUIDANCE CONTINUES TO
SHOW LARGE SCALE ASCENT INCREASING ACROSS THE EASTERN HALF OF THE
CWA IN PROXIMITY OF FRONT. AT THIS TIME LATEST HRRR AND RUC WOULD
SUPPORT SCATTERED THUNDERSTORMS FORMING GENERALLY EAST OF GOODLAND
AND THEN INCREASING IN COVERAGE THROUGH 00Z AS THEY MOVE
EASTWARD...QUICKLY ENDING OVER OUR CWA THIS EVENING. NAM CONTINUES
TO SHOW ISOLATED ACTIVITY FURTHER WEST ASSOCIATED WITH ELEVATED
CAPE AND H7 FRONTOGENESIS THROUGH THE OVERNIGHT PERIOD. CONFIDENCE
IS STILL TOO LOW TO INCLUDE ANY THUNDERSTORMS BEYOND THIS EVENING
WITH LARGE SCALE SUBSIDENCE AND SURFACE HIGH PRESSURE QUICKLY
BUILDING OVER THE CWA. I LEFT PATCHY FOG MENTION IN FORECAST OVER
EASTERN LOCATIONS...WITH CLAM WINDS AND STABLE AIR MASS SUPPORTING
RADIATIVE FOG DEVELOPMENT. GUIDANCE REALLY HAS NOT PICKED UP ON THIS
YET...SO I HAVE LEFT FOG COVERAGE LIMITED TO PATCHY.
.LONG TERM...(THURSDAY THROUGH WEDNESDAY)
ISSUED AT 246 PM MDT WED JUL 25 2012
HIGH PRESSURE MOVES INTO THE PLAINS STATES AT THE SURFACE THURSDAY
AND FRIDAY AS THE UPPER RIDGE AMPLIFIES OVER THE INTERMOUNTAIN
WEST AND MOVES EAST OVER THE ROCKIES. PRECIPITATION CHANCES ARE
MINIMAL ON THURSDAY AND THURSDAY NIGHT AS A RESULT. BY FRIDAY
EVENING THE SURFACE HIGH MOVES FAR ENOUGH TO THE EAST WITH A LEE
TROUGH DEEPENING IN THE VICINITY OF THE FAR EASTERN COLORADO
BORDER TO FORM A CONVERGENCE AREA OVER THE WESTERN PORTION OF THE
FORECAST AREA AS A SHORT WAVE TROUGH IN THE UPPER LEVEL FLOW MOVES
OVER THROUGH THE TOP OF THE RIDGE AND CLIPS THE NORTHERN SECTIONS
OF THE FORECAST AREA FRIDAY NIGHT. THIS SETUP WILL BRING A BETTER
CHANCE OF THUNDERSTORMS FRIDAY AFTERNOON AND EVENING. SEVERAL
ADDITIONAL SHORT WAVE TROUGHS MAKE THEIR WAY AROUND THE UPPER
RIDGE AND CLIP THE FORECAST AREA FROM SATURDAY THROUGH TUESDAY.
WITH A SURFACE TROUGH ALSO REMAINING OVER MAINLY THE WESTERN
PORTION OF THE FORECAST AREA DURING THIS TIME...THEREFORE EXPECT
TEMPERATURES TO REMAIN VERY WARM WITH ADDITIONAL DIURNALLY DRIVEN
ISOLATED TO SCATTERED THUNDERSTORMS MAINLY OVER THE WESTERN
PORTIONS OF THE FORECAST AREA. BY THE MIDDLE OF NEXT
WEEK...CURRENT INDICATIONS ARE THAT THE UPPER RIDGE WILL AMPLIFY
FURTHER AND MOVE MORE OVER THE PLAINS STATES...SENDING THE SHORT
WAVE IMPULSES FURTHER NORTH THROUGH THE NORTHERN PLAINS AND
POSSIBLY DECREASING THE POSSIBILITY OF PRECIPITATION ACROSS THE
CENTRAL HIGH PLAINS REGION.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 508 PM MDT WED JUL 25 2012
VFR CONDITIONS ARE FORECAST FOR THE 0Z TAFS. COLD FRONT CURRENTLY
RUNNING FROM JUST WEST OF NORTON SOUTHWEST TO NEAR RUSSELL SPRINGS
WILL DRIFT EAST QUITE SLOWLY FOR THE NEXT COUPLE OF HOURS. MEANWHILE AN
UPPER LEVEL SHORT WAVE TROUGH CURRENTLY SPARKING SCATTERED STORMS
OVER EASTERN COLORADO WILL MOVE THROUGH THE TRI- STATE AREA OVER THE
NEXT COUPLE OF HOURS...POSSIBLY BRINGING SOME ISOLATED TO
SCATTERED STORMS WITH IT. WILL LEAVE A VCTS MENTION IN THE TAFS
BUT WILL NOT INCLUDE A TEMPO GROUP AS AM NOT CONFIDENT ENOUGH THAT
STORMS WILL MOVE OVER ANY OF THE TAF SITES. THE UPPER LEVEL TROUGH
WILL MOVE OUT OF THE AREA DURING THE MID TO LATE EVENING BRINGING
PRECIP. CHANCES TO AN END.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...LOCKHART
AVIATION...JTL
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
1218 AM CDT THU JUL 26 2012
.UPDATE...
UPDATED FOR THE 06Z AVIATION DISCUSSION BELOW.
.DISCUSSION...
THE MAIN ISSUE IN THE SHORT TERM IS OBVIOUSLY THE CHANCES FOR
SHRA/TSRA LATE THIS AFTERNOON INTO THIS EVENING AS THE SURFACE LOW
SLIDES EAST AND THE FRONTAL BOUNDARY DROPS THROUGH THE AREA. LATEST
MSAS ANALYSIS AND SURFACE OBS SHOW A WELL DEFINED WIND SHIFT
CURRENTLY BISECTING THE FORECAST AREA FROM SOUTHWEST TO NORTHEAST...
AND SOME CONVECTION HAS TRIED TO DEVELOP NEAR THIS OVER THE PAST
SEVERAL HOURS... BUT HAS THUS FAR BEEN UNSUCCESSFUL. THE ACTUAL
FRONTAL BOUNDARY IS STILL WELL TO THE WEST OVER THE DAKOTAS... WHERE
THE DEWPOINT GRADIENT CAN BE FOUND. THIS WILL EVENTUALLY BE PUSHED
EAST THIS EVENING AS THE MAIN UPPER SHORTWAVE CURRENTLY SEEN NEAR
THE SASKATCHEWAN/MANITOBA BORDER PUSHES SOUTHEAST. AT THIS POINT...
IT/S QUESTIONABLE AS TO WHETHER THE FORCING ASSOCIATED WITH THE
ACTUAL UPPER WAVE AND COLD FRONTAL BOUNDARY WILL MANAGE TO GET ANY
CONVECTION GOING. CONTINUED CHANCE POPS THROUGH THE REMAINDER OF THE
AFTERNOON OVER THE WESTERN CWFA TO ACCOUNT FOR THAT POSSIBILITY.
OTHERWISE... TIED PCPN CHANCES TO THE INITIAL WIND SHIFT CURRENTLY
DROPPING THROUGH THE AREA... WHICH WILL BE INTERACTING WITH AN AREA
OF MLCAPE AOA 1500 J/KG. A SUBTLE SHORTWAVE FEATURE EVIDENT ON WATER
VAPOR... AND APPARENT IN THE RAP 400-300MB PV ANALYSIS... IS
CURRENTLY LIFTING NORTHEAST FROM EASTERN NEBRASKA... AND MAY HELP TO
GET ACTIVITY GOING NEAR THE WIND SHIFT DURING THE LATE AFTERNOON
OVER THE SOUTHERN AND SOUTHEAST PORTION OF THE FORECAST AREA. SO
OVERALL... KEPT CHANCE POPS OVER THE ENTIRE AREA FOR THE REMAINDER
OF THE AFTERNOON... THEN TRANSITIONED CHANCES SOUTH AND EAST THROUGH
THE EVENING.
CHANCES FOR PCPN DEPART TO THE EAST OVERNIGHT TONIGHT AS THE SURFACE
LOW AND FRONT CONTINUE TO PUSH EAST AND A WEAK SURFACE RIDGE MOVES
INTO THE AREA. THE MAIN UPPER TROUGH DROPS TOWARD THE AREA
TOMORROW... ALONG WITH A SECONDARY SURFACE WAVE AND COLD FRONTAL
BOUNDARY. WITH THE MID-UPPER COLD POOL MOVING INTO THE AREA...
TOGETHER WITH SOME LOW LEVEL CONVERGENCE ASSOCIATED WITH THE SURFACE
LOW AND FRONTAL BOUNDARY... WE SHOULD SEE SOME SCATTERED SHRA/TSRA
DROP SOUTHEAST ACROSS MUCH OF THE AREA FROM LATE MORNING THROUGH THE
AFTERNOON HOURS. THE BEST CHANCES WILL BE OVER THE NORTHERN AND
NORTHEAST PART OF THE AREA... BUT CAN/T RULE OUT SOME SHRA/TSRA AS
FAR SOUTH AS THE MINNESOTA RIVER VALLEY DURING THE AFTERNOON HOURS
DEPENDING UPON THE DEGREE OF DESTABILIZATION WHICH OCCURS FARTHER
SOUTH AWAY FROM THE HEART OF THE MID-LEVEL COLD POOL.
ON THURSDAY NIGHT... SCATTERED SHOWERS SHOULD DIMINISH
AROUND/AFTER SUNSET WITH THE LOSS OF DAYTIME HEATING. BY
FRIDAY... ANY RESIDUAL ACTIVITY SHOULD BE CONFINED TO WEST CENTRAL
WI COUNTIES NORTH OF INTERSTATE 94... AND THE WARRANTED COVERAGE
SHOULD ONLY BE 20 PERCENT. H85 TEMPS COOL TO AROUND +12C TO +13C
ON FRIDAY... SO HIGHS IN THE MID 70S TO LOWER 80S RANGE APPEAR
REASONABLE WITH SCT-BKN MID CLOUDS AROUND.
DRY AND NEAR NORMAL TEMPERATURES ARE EXPECTED FOR FRIDAY NIGHT AND
SATURDAY AFTER THE EXODUS OF THE TROUGH.
SATURDAY NIGHT AND SUNDAY WILL ARRIVE WITH THE NEXT OPPORTUNITY
FOR MEASURABLE PRECIPITATION... AS MULTIPLE WEAK SHORTWAVES TOP
THE PLAINS MID LEVEL RIDGE. RELATIVELY LOW CONFIDENCE ON WHETHER
FORCING ASSOCIATED WITH THE WAVES WILL BE SUFFICIENT TO OVERCOME
DRY/WARM AIR AT MID LEVELS... SO 30-40 POPS ARE AS HIGH AS WE WILL
GO FOR NOW.
FOR MONDAY THROUGH WEDNESDAY... HIGHS FROM 85-90 ARE
EXPECTED... ALONG WITH LOWS FROM THE MID 60S TO LOWER 70S. THE
PROXIMITY OF THE RIDGE AND MEAN WESTERLY/NORTHWESTERLY FLOW WILL
COMPLICATE THE PRECIPITATION FORECAST NEXT WEEK. HAVE OPTED TO GO
DRY AT THIS POINT SINCE CONFIDENCE/PROBABILITY ARE LOW AT THIS
TIME.
&&
.AVIATION.../06Z TAF ISSUANCE/
SHOWERY ACTIVITY EXPECTED TOMORROW AFTERNOON AND EARLY EVENING
ACROSS MAINLY EASTERN MN AND WESTERN WI. FAIRLY HIGH CONFIDENCE IN
SHOWERS WITH EMBEDDED SMALL THUNDERSTORMS. IT WILL BE MUCH COOLER
ALOFT TOMORROW...SO SMALL HAIL IS POSSIBLE WITH THE STRONGEST
CORES. THINK THERE WILL BE SCATTERED TO NUMEROUS SHOWERS TOMORROW
SURROUNDING KMSP...KRNH...KEAU WITH BKN CEILINGS RIGHT NEAR THE
UPPER END OF MVFR. COVERAGE WILL BE LESS THE FARTHER WEST YOU GO
IN MN. BREEZY NORTHWEST WINDS EXPECTED.
KMSP...BRIEF BOUGHTS OF MVFR POSSIBLE TOMORROW WITH SHOWERS AND
EMBEDDED THUNDERSTORMS. HIGH CONFIDENCE IN AT LEAST SHOWERS IN THE
VICINITY OF THE AIRPORT TOMORROW.
OUTLOOK FOR KMSP FRIDAY...MVFR CEILINGS POSSIBLE EARLY
FRIDAY NIGHT THROUGH SATURDAY...VFR EXPECTED
SATURDAY NIGHT THROUGH SUNDAY...BRIEF MVFR CEILINGS/VISIBILITIES
POSSIBLE WITH SHRA/TSRA.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
LS/CLF
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
413 AM CDT THU JUL 26 2012
.DISCUSSION...
Short Term (Today through Saturday Night)...
After 34 days without significant precipitation at the WFO, the
sounds of a steady rain and a great lightning show have been nothing
short of a welcomed miracle. Leading gust front now washing out
along the leading edge of the CWA, with elevated post-frontal
convection being maintained ahead of several well defined radar MCV
circulations. Aided by a 25-30 knot low level jet ascending over the
gust front, expect scattered convection to persist for the next
several hours with sufficient CAPE for lightning restricted
generally along and south of a MCI-IRK line.
For today, several forecast challenges related to POPs/temperatures.
Upstream mid level closed low is still over srn Manitoba, positioned
well NW of earlier model placement. This will lead to a much later
upper wave passage across the CWA today. Although muddied by
convection and nocturnal effects, it appears that the effective cold
front is still located across srn Nebraska into central Iowa,
denoted by a modest wind shift and dewpoint gradient. Pre-frontal
dewpoints have approaches seasonal highs in the lower 70s, driven
primarily by precipitation. My concern is that once nocturnal
activity dissipates and convective cloud debris erodes, strong
daytime heating could occur in a very moist and uncapped warm sector
ahead of a rather diffuse surface frontal zone. Per 06Z NAM and
recent HRRR guidance, this theory is well supported, and have
decided to drag POPs back to the northwest. Depending on how quickly
cloud cover erodes, the airmass could support surface based
thunderstorm development as early as 18Z. Increasingly northwesterly
flow aloft (although considerably stronger over the Ohio Valley)
could support some storm organization with an attendant threat for
damaging winds if activity grows upscale before exiting the CWA.
Temperatures will be highly conditional on the erosion of cloud
cover and subsequent convective development, but will opt for
lower-mid 90s as a hedge, with cooler readings certainly not out of
the question. Although on paper this seems like a huge improvement
from the past few weeks, the considerable increase in boundary layer
dewpoints will lead to a very humid conditions and heat indices
locally around 100 degrees.
With the frontal passage tonight, northwest upper flow will become
temporarily established over the area as the mean ridge position
reorganized over the southern High Plains. Seasonably strong
mid-upper flow will yield a rather impressive elevated baroclinic
zone over the region, which will translate to the surface with
daytime mixing. Have adjusted temperatures both Friday and Saturday
to account for this gradient, with hot temperatures persisting over
west central MO/ern KS and notably more tolerable conditions over NE
MO. This gradient becomes even more impressive Saturday and would
not be surprised to see highs in the upper 80s over NE MO vs. lower
100s over and south of Kansas City. Along with the brief intrusion
of cooler air into portions of the area, it is possible that
dewpoints Fri/Sat could be even lower than forecast, with some
guidance suggesting they fall into the lower 50s.
To further complicate matters, there is justifiable concern about
MCS activity on Saturday into Saturday Night. Most 00Z guidance show
a Pacific shortwave emerging from the Rockies Friday evening,
sparking a convective complex over the Black Hills region. The sharp
elevated baroclinic zone/instability axis would suggest this complex
would be well maintained along an ESE track, reaching nrn MO
Saturday afternoon. Meanwhile, the ridge will continue to
strengthen, helping return that frontal zone north as a warm front.
Thus, the question remains whether the edge of the cap is across nrn
MO or back into Iowa by the time this system arrives. Low chance
POPs probably the best way to go for now, although this will
probably end up being an all or nothing event once it draws closer.
Bookbinder
Medium Range (Sunday through Wednesday)...
Sunday - Monday: A upper level ridge of high pressure will extend
from the Southern Plains northwestward into the Eastern Rockies.
This will leave the area under northwesterly flow aloft. A series of
shortwaves are progged to round this ridge and move into the local
area on Sunday and Monday. This will make for a challenging forecast
through this period. The best chances for precipitation will be
mainly across the northern and eastern half of the CWA through
Monday although a complex of thunderstorms could develop on Sunday
and bring the chance for thunderstorms to the southern half of the
CWA as well and as such kept slight chance POPs across the southern
portion of the forecast area on Sunday. These system will also make
forecasting temperatures challenging with the northern CWA being
cooler with the potential for precipitation and excess cloud cover.
Thusly for Sunday and Monday have a gradient of temperatures ranging
from the lower 90s across north central Missouri sloping to the
upper 90s across east central Kansas and west central Missouri.
Tuesday - Wednesday: The upper level ridge will shift slowly
eastward with the local area moving under its influence by Tuesday.
This in turn will keep the local area dry through the period.
Temperatures on the other hand will warm a bit as height rises
through the period will help temperatures warm into the mid 90s to
near 100.
73
&&
.AVIATION...
For the 06Z TAFs, scattered showers and thunderstorms will affect
the terminals through the pre-dawn hours as a cold front works
southeast. Will see gusty winds initially with the storms due to the
steep low level lapse rates. Convection will end from north to south
in the morning with clearing skies for the afternoon hours.
Generally VFR conditions except with overnight thunderstorms which
could briefly send ceilings down to MVFR.
MJ
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS OMAHA/VALLEY NE
1149 PM CDT WED JUL 25 2012
.UPDATE...
&&
.AVIATION...
06Z TAFS FOR KOFK...KOMA AND KLNK.
POST-FRONTAL CONVECTION CONTINUING THIS MORNING OVER SERN NEB. AT
THIS POINT...IT APPEARS PER LATEST RADAR TREND THAT TSRA ACTIVITY
IS DONE AT ALL TERMINALS. VFR CONDITIONS THEN PREVAILING THRU THE
24HR FCST PD.
DEE
&&
.PREV DISCUSSION... /ISSUED 313 PM CDT WED JUL 25 2012/
DISCUSSION...
THUNDERSTORMS TONIGHT...THEN SOMEWHAT COOLER TEMPERATURES AND
SPORADIC PRECIP CHANCES THROUGH THE WEEKEND...ARE THE PRIMARY
FORECAST CONCERNS.
COOL FRONT WAS DRIFTING SOUTHEAST THROUGH THE CWA THIS
AFTERNOON...AND HAD JUST SLIPPED PAST A COLUMBUS TO TEKAMAH LINE AS
OF 2 PM. PLUME OF MID LEVEL MOISTURE ACROSS WESTERN INTO NORTH
CENTRAL NEBRASKA NOTED ON WATER VAPOR IMAGERY WAS SHIFTING EAST OVER
THE FRONTAL BOUNDARY. SCATTERED SHOWERS AND STORMS WERE FIRING UNDER
THIS PLUME...AFFECTING MUCH OF CENTRAL NEBRASKA AND WERE TRYING TO
SNEAK INTO OUR NORTHWESTERN CWA. SURFACE-BASED CAPE VALUES WERE
TOPPING 2000 J/KG ALONG FRONTAL BOUNDARY THIS AFTERNOON...BUT
SIGNIFICANT CINH WAS ALSO NOTED. SOMEWHAT LESS UNSTABLE AIR WAS
NOTED USING MIXED-LAYER CAPE WHERE VALUES WERE BETWEEN 1000 AND 1500
J/KG. EFFECTIVE AND BULK SHEAR WERE BOTH WEAK GIVEN RELATIVELY LIGHT
MID LEVEL FLOW. SO ORGANIZED SURFACE-BASED STORMS DO NOT APPEAR
LIKELY THIS EVENING. HOWEVER STEEP MID LEVEL LAPSE RATES SHOULD
ALLOW FOR QUICK VERTICAL DEVELOPMENT OF ANY CONVECTION THAT FIRES IN
OUR CWA...THEN COLLAPSING OF THOSE STORMS COULD PRODUCE STRONG TO
SEVERE WIND GUSTS WITH TEMPERATURE/DEW POINT SPREADS APPROACHING
40F. DOWNDRAFT CAPE OF 1800 J/KG WAS ALSO MAXIMIZED ALONG FRONTAL
BOUNDARY.
GIVEN SHOWERS AND STORMS WERE ALREADY FIRING AND APPROACHING THE
CWA...COMBINED WITH ALL SHORT-RANGE MODEL OUTPUT SUGGESTING
PRECIPITATION NEAR AND BEHIND FRONTAL BOUNDARY...WILL INCREASE POPS
ACROSS MOST OF THE CWA FOR THIS EVENING. 15-16Z HRRR SEEMS TO
HAVE A DECENT HANDLE ON CURRENT PRECIPITATION...AND FIRES
CONVECTION ALONG FRONTAL BOUNDARY AS IT SINKS FARTHER SOUTHEAST
INTO THE CWA. MODELS ALSO SHOW POST-FRONTAL PRECIPITATION
CONTINUING THROUGH THE NIGHT AIDED BY RIGHT ENTRANCE REGION OF MID
LEVEL JET...THOUGH COVERAGE WILL CERTAINLY WANE AS WE GO PAST
MIDNIGHT.
SOME LINGERING SHOWERS/STORMS COULD AFFECT OUR FAR SOUTHEAST CWA
THURSDAY MORNING...BUT THAT SHOULD EXIT QUICKLY. THEN NORTHWEST
LOW LEVEL FLOW AND SLOWLY COOLING 850 TEMPERATURES POINT TO
CLOSER-TO-NORMAL TEMPERATURES THURSDAY AFTERNOON. GFS IS COOLER
THAN NAM IN THIS REGARD. WILL CONTINUE WITH HIGHS IN THE LOWER
90S...WHICH IS RIGHT IN THE MIDDLE OF NAM/GFS MOS NUMBERS. ONE
CAVEAT TO WATCH FOR IS DOWNSLOPING NORTHWEST FLOW PUSHING HIGHS A
FEW DEGREES WARMER AS PER NAM.
SURFACE HIGH WILL SETTLE ACROSS THE AREA THROUGH FRIDAY AFTERNOON
WITH RETURN FLOW BEGINNING FRIDAY NIGHT. LOWS IN THE LOW TO MID 60S
LOOK GOOD FOR FRIDAY MORNING...WITH HIGHS FRIDAY AFTERNOON RIGHT
AT NORMAL IN THE UPPER 80S.
GFS HAS ADVERTISED THE LAST FEW DAYS A MID LEVEL SHORTWAVE ROLLING
INTO THE PLAINS FRIDAY NIGHT AND SATURDAY MORNING. OTHER MODELS HAVE
COME IN LINE WITH THIS THINKING...SO CONFIDENCE IS GROWING ON PRECIP
CHANCES THEN. EXPECT WARM ADVECTION ON MODERATE LOW LEVEL JET AHEAD
OF WAVE TO FIRE CONVECTION AFTER MIDNIGHT IN NORTHEAST
NEBRASKA...WITH THIS PRECIP TURNING SOUTHEAST DOWN THE RIVER BY
MORNING. HAVE INCREASED POPS ACCORDINGLY...WITH HIGHEST CHANCES
ALONG SOUTH DAKOTA BORDER AND THROUGH AREAS NORTH AND NORTHEAST OF
OMAHA.
A SECOND SHORTWAVE LOOKS TO ROLL THROUGH AGAIN SATURDAY NIGHT AND
SUNDAY WITH SIMILAR WARM ADVECTION SIGNALS SUGGESTING CONVECTION
WILL FIRE AGAIN. ECMWF IS MORE BULLISH ON FRIDAY NIGHT WAVE...AND
PUSHES SATURDAY NIGHT PRECIP A BIT FARTHER TO THE NORTHEAST THAN
GFS.
LINGERING FRONTAL BOUNDARY BEHIND THIS SYSTEM WILL MOST LIKELY SET
UP ACROSS OUR CWA FOR MONDAY...WHICH MAY FOCUS A FEW STORMS MONDAY
AFTERNOON. SO WILL KEEP A SMALL POP GOING THEN.
UPPER RIDGE WILL BEGIN BUILDING BACK INTO THE REGION BEYOND
MONDAY...SO HAVE KEPT FORECAST DRY AND A BIT WARMER THEN. HAVE
HIGHS IN THE UPPER 80S TO LOWER 90S SATURDAY...THEN LOWER 90S
SUNDAY...BEFORE GRADUALLY INCREASING HIGHS TOWARD THE MID AND
UPPER 90S BY WEDNESDAY.
DERGAN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1122 PM MDT WED JUL 25 2012
.AVIATION...
06Z TAF CYCLE
UPPER HIGH CENTER TO SHIFT OVER NORTHWEST NM THURSDAY. ISOLD TO WDLY
SCT CONVECTION TO LINGER OVER EASTERN NM BEFORE 12Z EAST OF THE
PECOS VALLEY AS SURFACE BOUNDARY SAGS INTO THE REGION.
&&
.DISCUSSION...253 PM MDT WED JUL 25 2012...
...POTENTIAL FOR LOCALLY HEAVY RAIN WILL CONTINUE THRU THE WEEKEND...
AFTERNOON RADAR AND SATELLITE TRENDS ALIGNING VERY WELL WITH THE LATEST
HIRES HRRR AND RUC13 MODELS...INCREASING CONFIDENCE THAT MAIN FOCUS FOR
HEAVY RAINFALL WILL BE ALONG AND EAST OF THE CENTRAL MT CHAIN INTO THIS
EVENING. PWAT VALUES PER CIRA IMAGERY ARE BTWN 1 AND 1.2 INCHES WHICH
IS 100-125 PCT OF NORMAL. A WELL DEFINED VORT MAX NEARLY STATIONARY OVER
THE EAST CENTRAL PLAINS WILL FOCUS WITH A BACK DOOR FRONT TO PRODUCE
SCT TO NMRS STORMS THIS EVENING. DRIER STABLE AIR WILL QUICKLY DIMINISH
MOST ACTIVITY FOR CENTRAL AND WESTERN AREAS BY MIDNIGHT.
THE BACK DOOR FRONTAL BNDRY WILL SLIDE INTO THE RIO GRANDE VALLEY TMRW
AFTERNOON AIDED BY CONVECTION ALONG THE EAST SLOPES. GAP WINDS ARE
EXPECTED MOST AREAS. MAIN FOCUS OF THETA-E RIDGE AXIS WILL BE OVER MANY
AREAS OF CENTRAL NM. PWAT VALUES CONTINUE TO RISE TO BTWN 1.2 AND
1.4 WHICH WILL POSE AND ELEVATED THREAT FOR FLASH FLOODING. STEERING
FLOW WILL BE WEAKEST AND MOST CONVERGENT ALONG THE CONT DVD THEREFORE
A WATCH IS POSSIBLE HOWEVER WILL DELAY TO FOLLOWING SHIFTS. HAVE RAISED
POPS SLIGHTLY MORE TO COVER HIGHER CHANCES FOR THE CENTRAL VALLEYS.
BY FRIDAY THE FOCUS SHIFTS TO THE WESTERN HALF OF THE STATE WHERE HEAVY
RAINFALL POTENTIAL CONTINUES. PWATS ADVERTISED BTWN 1.2 AND 1.4 AGAIN
WITH LOTS OF INSTABILITY. STEERING FLOW WILL BECOME MORE SW TO NE AND
SPEED UP TO NEAR 15KTS SO WHILE HEAVY RAINFALL IS LIKELY THE POTENTIAL
FOR FLASH FLOODING MAY BE LIMITED TO TRAINING CELLS. EXPECT ACTIVITY
TO SLIDE NORTHEAST ON OUTFLOWS TOWARD THE RIO GRANDE VALLEY EACH EVENING
IN THIS VERY MOIST STEERING PATTERN. MAX TEMPS WILL REMAIN VERY CLOSE
TO SEASONAL NORMS WHILE MIN TEMPS REMAIN 5 TO 10F ABOVE NORMAL. GUYER
&&
.FIRE WEATHER...
AS ADVERTISED THE MAIN WETTING STORM FOCUS WILL SHIFT FROM THE
WESTERN HALF LIKE WAS SEEN YESTERDAY TO THE EASTERN HALF TODAY. A
BACK DOOR COLD FRONT HAS CUT INTO THE NORTHEAST PLAINS AND HAS
CREATED ABUNDANT STORM COVERAGE ACROSS THE SANGRE DE CRISTOS.
STORMS WILL TEND TO DRIFT OFF TO THE SOUTHEAST AND IMPACT THE
EASTERN PLAINS TONIGHT. WITH THE BOUNDARY AROUND...LOOK FOR
CONTINUED ABUNDANT RAINFALL ACROSS THE CENTRAL MOUNTAINS AND LARGE
PORTIONS OF THE EASTERN PLAINS ON THURSDAY. MORE ISOLATED ACTIVITY
WILL BE FOUND ACROSS THE WEST DURING THE NEXT 36 HOURS AS DRIER
AIR FILTERS IN. LOOKING AT SOME TEEN HUMIDITIES ACROSS THE FOUR
CORNERS AREA BY THURSDAY. HIGH TEMPERATURES WILL BE NEAR NORMAL
ALTHOUGH PERHAPS A FEW DEGREES BELOW NORMAL ACROSS THE NORTHEAST
ON THURSDAY.
BACK DOOR FRONT WILL INFILTRATE THE RIO GRANDE VALLEY LATER TONIGHT
BUT MAKE MORE OF A PUSH WESTWARD UNDERNEATH THE UPPER HIGH THURSDAY
NIGHT INTO FRIDAY MORNING. THIS WILL PUSH THE FOCUS OF WETTING
STORMS BACK TO THE WEST ON FRIDAY. ESPECIALLY FAVORING THE
CONTINENTAL DIVIDE REGION AS DEPICTED BY THE GFS AND TO A LESSER
EXTENT THE ECMWF AND NAM. THIS SHOULD BE THE REPLENISHMENT OF
MOISTURE THAT IS NEEDED TO FUEL HIGHER COVERAGE OF WETTING STORMS
ACROSS THE WESTERN HALF.
IT APPEARS THAT A CONSOLIDATED UPPER HIGH...BOTH BERMUDA AND
SUBTROPICAL...SHOULD BE FOUND OVER THE RED RIVER VALLEY BETWEEN TX
AND OK DURING THE WEEKEND AND EARLY NEXT WEEK. MODELS ARE SHOWING A
NICE MONSOONAL PLUME SIGNATURE OVER THE WESTERN THIRD TO HALF OF THE
FORECAST AREA DURING THIS PERIOD...ESPECIALLY DURING THE WEEKEND
TIME FRAME. PERHAPS SOME SUBSIDENCE/MID LVL DRY SLOT EFFECTS OVER THE
EASTERN PLAINS ALTHOUGH STEERING FLOW BY EARLY NEXT WEEK COULD TAKE
STORMS OFF THE CENTRAL MTNS INTO THE EASTERN PLAINS LATER IN THE DAY
PERIOD.
BOTH ECMWF AND GFS TREND THE UPPER HIGH CENTER BACK OVER THE STATE
AS NEXT WEEK PROGRESSES. THIS WOULD ESSENTIALLY STEER THE MONSOONAL
PLUME FURTHER WEST BUT COULD ALSO BRING ANOTHER BACK DOOR COLD FRONT
INTO THE EQUATION.
EITHER WAY...UNSETTLED WEATHER EXPECTED THROUGH THE NEXT SEVERAL
DAYS WITH THE INITIAL FOCUS ACROSS THE EASTERN HALF BUT
TRANSITIONING WESTERN HALF AS THE WEEK PROGRESSES INTO THE
WEEKEND. 50
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
447 AM EDT THU JUL 26 2012
.SYNOPSIS...
HOT AND HUMID CONDITIONS WILL GIVE WAY TO STRONG TO SEVERE
THUNDERSTORMS TODAY AS A COLD FRONT MOVES SOUTHWEST TOWARD THE
OHIO VALLEY. THE FRONT WILL PUSH THROUGH THE AREA TONIGHT AND A
LOW PRESSURE SYSTEM WILL CROSS OUR AREA ON FRIDAY...BRINGING
ADDITIONAL SHOWERS AND THUNDERSTORMS TO THE REGION. HIGH PRESSURE
WILL THEN BRING MORE SEASONABLE TEMPERATURES AND DRIER CONDITIONS
FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
STEADY WARM ADVECTION UNDER SOUTHWEST FLOW WILL CONTINUE THROUGH
SUNRISE. OUTFLOW FROM CONVECTION TO OUR NORTHWEST IS TRIGGERING
SHOWERS AND THUNDERSTORMS ACROSS PARTS OF ILLINOIS AND INDIANA.
SOME OF THESE STORMS WILL HOLD TOGETHER AND MAKE IT TO OUR WESTERN
ZONES JUST AFTER SUNRISE THIS MORNING. AS THIS ACTIVITY OUTRUNS
THE FRONTAL FORCING...AND WE ENTER THE DIURNAL MINIMUM FOR
CONVECTION...ANY REMAINING SHOWERS/THUNDERSTORMS WILL DIMINISH BY
MID MORNING. HAVE THEREFORE FORECAST A LULL IN ANY POPS DURING
THE MID MORNING UNTIL EARLY AFTERNOON. THIS FORECAST TO START OFF
THE DAY BEST RESEMBLES THE HRRR AND SREF. HAVE AVOIDED USING THE 00Z
ARW AND SPC WRF FOR THIS PACKAGE...AS THEY APPEAR TO BRING AN
INITIATION OF TOO MUCH CONVECTION TOO FAR EAST...TOO EARLY IN THE
DAY. THIS IS LIKELY DUE TO THE HANDLING OF THE AFOREMENTIONED
OUTFLOW BOUNDARY INTERACTING WITH OUR UNSTABLE AIRMASS...AND NOT
THE DEVELOPMENT OF THE MORE INTENSE...SYNOPTICALLY FORCED
CONVECTION THAT WILL OCCUR LATE THIS AFTERNOON.
WITH ONGOING WARM ADVECTION AND INCREASING SOUTHERLY FLOW TO START
OFF THE DAY...THE BOUNDARY LAYER WILL BE WELL MIXED. TEMPERATURES
OF 20 TO 21 C AT 850 HPA...UNDER PARTLY CLOUDY SKIES...WILL BRING
SURFACE TEMPERATURES QUICKLY INTO THE LOW 90S BY THE EARLY
AFTERNOON. THESE WARM TEMPERATURES WILL COMBINE WITH DEWPOINTS IN
THE LOW 70S TO PRODUCE HEAT INDICES GREATER THAN 100 DEGREES BY
THE EARLY AFTERNOON. HAVE THEREFORE CONTINUED THE HEAT HEADLINES
FOR TODAY.
A SURFACE LOW MOVING EASTWARD ACROSS THE GREAT LAKES WILL DRAG A
COLD FRONT SOUTHWESTWARD TOWARD THE OHIO VALLEY TODAY. IN THE LULL
BEHIND ANY MORNING PRECIPITATION...OUR ATMOSPHERE WILL QUICKLY
DESTABILIZE. THE COMBINATION OF PRE-FRONTAL CONVERGENCE AND A VERY
UNSTABLE AIRMASS WILL TRIGGER THE DEVELOPMENT OF NUMEROUS
THUNDERSTORMS.
THESE INTENSE STORMS WILL BE IN AN ENVIRONMENT OF INCREASING
0 TO 3 KM SHEAR AS THE DAY PROGRESSES...STARTING OFF THE AFTERNOON
AROUND 25 KTS AND ENDING THE DAY AROUND 35 KTS. THE MEAN FLOW FROM
0 TO 3 KM WESTERLIES WILL ALSO INCREASE TO OVER 30 KT THIS
AFTERNOON. THIS WILL LIKELY PRODUCE STORMS THAT WILL ORGANIZE INTO
A QUASI-LINEAR SYSTEM BY LATE THIS AFTERNOON...SURGING EASTWARD
AHEAD OF THE PRE-FRONTAL CONVERGENCE ZONE. AS SHEAR
INCREASES...SOME SUPERCELL CHARACTERISTICS WILL BECOME POSSIBLE
WITH ADDITIONAL LATER THUNDERSTORM DEVELOPMENT BY EARLY THIS
EVENING. THIS SECOND ROUND WILL BE ASSOCIATED WITH AN EMBEDDED
SHORTWAVE. THIS MEANS THAT THERE MAY BE A ONE TWO PUNCH WITH
CONVECTION FOR SOME LOCATIONS IN OUR FORECAST AREA BETWEEN THIS
AFTERNOON AND EVENING TIME FRAME. A SIDE NOTE...THE FIRST ROUND
AND SECOND ROUND MAY NOT HAVE TOO MUCH OF A TIME LAPSE BETWEEN
THEM.
THE MAIN THREAT FROM THE OVERALL CONVECTION TODAY WILL BE
WIDESPREAD DAMAGING WINDS WITH POWER OUTAGES POSSIBLE. HOWEVER
LARGE HAIL COULD OCCUR WITH ANY OF THE STRONGER UPDRAFTS.
ALSO...CANNOT RULE OUT AN ISOLATED TORNADO IF THE RIGHT CONDITIONS
COME TOGETHER LATE TODAY...LL SHEAR...BOUNDARY INTERACTION...ETC.
IF PARTICULAR LOCATIONS DO RECEIVE A ONE TWO PUNCH OF
CONVECTION...OR TRAINING OF STORMS OCCURS...THEN LOCALIZED
FLOODING CAN ALSO BECOME AN ISSUE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
CONVECTION WILL SHIFT SOUTHEAST LATE THIS EVENING AND WITH THE
LOSS OF DAYTIME HEATING...WILL GRADUALLY LOSE IT/S INTENSITY.
HOWEVER...STORMS WILL STILL BE INTENSE ENOUGH TO PRODUCE SEVERE
WEATHER AT LEAST THROUGH THE FIRST PART OF THE OVERNIGHT PERIOD.
HAVE THEREFORE KEPT THE MENTION OF SEVERE STORMS IN THE GRIDS
THROUGH 03Z. BY THAT TIME...MOST ACTIVITY WILL HAVE SHIFTED TO OUR
SOUTHEASTERN ZONES. THERE...SOME ONGOING CONVECTIVE ACTIVITY COULD
POSE ADDITIONAL FLOOD ISSUES...SHOULD THUNDERSTORMS BEGIN TO TRAIN
OVER THE SAME LOCATIONS LATE TONIGHT.
ON FRIDAY THERE ARE STILL SOME DIFFERENCES ON HOW THE MODELS HANDLE
THE SHORTWAVE PIVOTING ACROSS THE GREAT LAKES. THE SREF AND NAM
DEVELOP A WEAK CLOSED SURFACE LOW AHEAD OF THE TROUGH AND DIVE IT
SOUTHWARD TOWARD OUR AREA. THIS WOULD PRODUCE A ROUND OF AFTERNOON
CONVECTION FOR THE EASTERN TWO THIRDS OF THE FORECAST AREA. THE
ARW AND NMM BOTH AGREE WITH THIS SOLUTION. HAVE FORECAST 50/50 POPS
FOR MUCH OF THE AREA FOR FRIDAY AFTERNOON TO REFLECT THIS. DID NOT
GO LIKELY ON POPS SINCE THE ECMWF STILL DOES NOT AGREE WITH THIS
SOLUTION.
REGARDLESS OF WHICH MODEL YOU CHOOSE FROM...COLD ADVECTION FINALLY
STABILIZES US FRIDAY NIGHT AS HIGH PRESSURE BEGINS TO BUILD ACROSS
THE OHIO VALLEY. A FEW RESIDUAL SHOWERS AND THUNDERSTORMS COULD
LINGER INTO SATURDAY ACROSS THE EAST AS THE SFC LOW DEPARTS.
SATURDAY THROUGH SATURDAY NIGHT WILL MARK A RETURN TO MORE
SEASONABLE TEMPERATURES AS THE SFC HIGH PRESSURE SETTLES ACROSS
THE REGION.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
SUNDAY IS PROBABLY THE DAY WITH HIGHEST FORECAST CONFIDENCE AS
SFC HIGH PRESSURE BUILDS OVER THE CWA. TEMPERATURES WILL BE
SEASONABLE WITH FAIRLY LOW HUMIDITY.
THE GFS/NCEP MODELS TAKES A MORE AMPLIFIED TURN BEGINNING
MONDAY...WITH 500 MB HEIGHTS AT ILN RESIDING ON THE LOW END OF NAEFS
SPREAD BY MID WEEK. THIS AFFECTS PCPN FORECASTS MORE THAN
TEMPERATURES HOWEVER OVER THE LOCAL AREA (AS 00Z AND 12Z ECMWF HOLD
A STRONGER SFC RIDGE IN PLACE). TOOK AN ENSEMBLE APPROACH WITH THE
FORECAST...WHICH DID NOT SIGNIFICANTLY CHANGE THE GOING FORECAST.
TUESDAY WILL HAVE THE HIGHEST PCPN CHANCES...SUPPORTED BY
ENSEMBLES...AS WELL AS A SFC BDY/UPPER WAVE THAT MAY SAG DOWN INTO
THE AREA. CANNOT TOTALLY RULE OUT PCPN MONDAY/WEDNESDAY BUT LIMITED
TO 20 POPS. TEMPERATURES WILL RISE SOME AS LOW LEVEL FLOW BECOME
MORE SOUTHERLY...BUT AT THIS TIME LOOK TO REMAIN WITHIN 5 DEGREES OF
NORMAL. HUMIDITY WILL ALSO INCREASE SLIGHTLY...HOLDING UP OVERNIGHT
LOWS.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
MAINLY CLEAR SKIES ACROSS THE AREA THIS MORNING WITH THE REGION
NOW WELL INTO THE WARM SECTOR. AS THE COLD FRONT OFF TO OUR
NORTHWEST SAGS SLOWLY SOUTHEAST THROUGH THIS AFTERNOON...WE WILL
SEE AN INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS. SEVERAL OF
THE LATEST MODEL RUNS ARE SUGGESTING AN OUTFLOW BOUNDARY FROM
CONVECTION OFF TO OUR NORTHWEST WILL MOVE INTO OUR AREA LATER
THIS MORNING INTO EARLY AFTERNOON. IF THIS OCCURS...IT WILL LIKELY
SERVE AS A FOCUS FOR THE FIRST ROUND OF CONVECTION TO AFFECT OUR
TAF SITES AS THE AIRMASS IS ALREADY VERY UNSTABLE EARLY THIS
MORNING. HOWEVER...GIVEN THE RIDGE IN PLACE OVER OUR AREA AT THIS
TIME...AM AFRAID THE MODELS MAY BE A LITTLE FAST BRINGING THIS INTO
OUR AREA. ON THE OTHER HAND...IT IS TOUGH TO DISCOUNT THIS
SOMEWHAT FASTER SOLUTION GIVEN THE MODEL TRENDS...SO WILL OPEN UP
A SLIGHTLY BIGGER WINDOW ON THE CONVECTION CHANCES THIS AFTERNOON.
WITH THE VERY UNSTABLE AIRMASS EXPECTED THROUGH THIS AFTERNOON...STRONG
DOWN BURST WINDS WILL BE POSSIBLE WITH THE STORMS...ESPECIALLY
THOSE THAT OCCUR IN THE AFTERNOON HOURS. THIS INITIAL ROUND OF
STORMS WILL LIKELY MOVE OFF TO THE SOUTH BY LATE AFTERNOON. A
SECONDARY AREA OF SHOWERS AND THUNDERSTORMS WILL THEN BE POSSIBLE
HEADING INTO THIS EVENING AS A MID LEVEL SHORT WAVE MOVES IN
QUICKLY FROM THE WEST. EXPECT THE BEST CHANCE FOR THIS
REDEVELOPMENT TO BE AT THE SOUTHERN TAF SITES.
OUTLOOK...THUNDERSTORMS ARE POSSIBLE THROUGH FRIDAY NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
OHZ026-034-035-042>046-051>056-060-062>065-070>074-
078>082-088.
EXCESSIVE HEAT WARNING UNTIL 8 PM EDT THIS EVENING FOR OHZ061-
077.
KY...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
KYZ089>100.
IN...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
INZ050-058-059-066-073>075-080.
&&
$$
SYNOPSIS...LATTO
NEAR TERM...LATTO
SHORT TERM...LATTO
LONG TERM...SNYDER
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
213 AM EDT THU JUL 26 2012
.SYNOPSIS...
HIGH PRESSURE OFF THE SE COAST WILL ALLOW A WARM FRONT OVER THE
OHIO VALLEY TO SURGE INTO THE REGION LATER TONIGHT AND THURSDAY.
A SLOW MOVING COLD FRONT WILL SLIDE ACROSS THURSDAY INTO FRIDAY
BRINGING AN ACTIVE PERIOD OF WEATHER THROUGH THE END OF THE WEEK
WITH STRONG TO SEVERE THUNDERSTORMS POSSIBLE.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
HIGH PRESSURE HAS SLIPPED OFF TO OUR SE. A WARM FRONT OVER OHIO
WILL CONTINUE TO MARCH NE THRU THE REGION SETTING THE STAGE FOR
ANOTHER VERY WARM/HUMID DAY THURSDAY.
BIGGEST QUESTION FOR THE VERY NEAR TERM IS IF WE WILL SEE A LINE
OF SEVERE STORMS RACE ACROSS THE FCST AREA AFTER MIDNIGHT.
REGIONAL RADAR MOSAIC SHOWS AN MCS FORMING RAPIDLY OVER MICHIGAN.
HIGH RES HRRR AND COSPA NOW BACK OFF THE IDEA OF A BOW ECHO
LOOKING FEATURE SWEEPING THRU AND BRING MORE DISORGANIZED STORMS
INTO THE FCST AREA LATER AT NIGHT...TWD DAWN. THIS ALSO FITS WITH
THE NEW NAM WHICH SUGGESTS THE BEST CONVECTION STAYS NORTH OF THE
BORDER THRU 12Z FOR THE MOST PART.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/...
SPC HAS A MDT RISK OF SVR TSRA VERY LATE TONIGHT AND THURSDAY.
CLUSTERS OF DISCRETE...SUPERCELL STRUCTURES OVER THE NW MTNS DURING
THE PREDAWN HOURS THURSDAY...MAY EVOLVE INTO A LARGER MCS/MCC ACROSS
CENTRAL PENN WITH SWATHS OF WIND DAMAGE /AND FREQUENT LIGHTNING/
BEING THE PRIMARY THREAT ACROSS CENTRAL PENN AND THE SUSQ VALLEY
DURING THE MID MORNING HOURS. 09Z SREF AND 12 GEFS BOTH HIGHLIGHT
THE EXTREMELY STRONG FORCING TRIGGERING THIS INITIAL ROUND OF
TSRA...AS A +3-5 ST DEVIATION WESTERLY 850 MB JET PUSHES ACROSS PENN
AND NEW YORK BETWEEN 08Z AND 14Z THURSDAY.
IN ADDITION...THE SREF/S 850 MB MOISTURE FLUX IS SO TO SAY..OFF THE
CHARTS DURING THE AFOREMENTIONED PERIOD OF INTEREST THURSDAY
MORNING...6 OR MORE STANDARD DEVIATIONS ABOVE NORMAL.
A BRIEF...FEW HOUR PERIOD OF MINIMAL CONVECTIVE ACTIVITY MAY OCCUR
BETWEEN 14-17Z AS COMPENSATING SUBSIDENCE OCCURS IN THE WAKE OF THE
MCS...BEFORE AREAS OF POTENTIALLY SEVERE TSRA FIRE DURING THE MID TO
LATE AFTERNOON HOURS.
ANOMALOUSLY HIGH 850 MB TEMPS OF 20-22C WILL COMBINE WITH A GUSTY
WSW SFC WIND AND ABUNDANT LATE MORNING - MID AFTERNOON SUN TO PUSH
TEMPS TO NEAR RECORD HIGHS WITH HEAT INDICES IN THE 90S ACROSS THE
MTNS...TO BETWEEN 100-104F IN THE SOUTHERN VALLEYS AND THROUGHOUT
MUCH OF THE LOWER TO MID SUSQ VALLEY. RECORDS FOR 7/26 ARE 100F IN
MDT...AND 98F IN KIPT.
A HEAT ADVISORY HAS BEEN POSTED FOR 16Z THU-00Z FRIDAY FOR NEARLY
THE SE HALF OF THE CWA.
THE SREF MEAN CAPES FOR THE AFTN RISE INTO THE 2000-2500J/KG RANGE -
ESP OVER THE NRN HALF OF THE AREA. WINDS WILL BE UNIDIRECTIONAL AT
THAT POINT AND 0-6KM BULK SHEAR AROUND 40KTS. THE SFC LOW PASSING
THROUGH NY STATE AND INTO NEW ENGLAND WILL TRY TO PUSH A SLIGHTLY
COOLER AIR MASS IN FROM THE NORTH. THIS WILL CREATE A GREAT FOCUS
FOR CONVECTION AND LITTLE CINH WILL ALLOW FOR SCT/NMRS TSRA IN THE
AFTN AND INTO THE EARLY PART OF THE NIGHT. HOWEVER...LACK OF HEATING
WILL MOST LIKELY DIMINISH/KILL THE DEEP CONVECTION WITH ONLY WEAK
CONVERGENCE PRESENT ALONG THE BOUNDARY...AND POOR INFLUX OF
ADDITIONAL MSTR FROM THE GULF.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
SVR WX THREAT MAY PERSIST INTO THURS NIGHT BEFORE TRENDING WEAKER
TOWARD CLIMATOLOGICAL CONVECTIVE MINIMUM/EARLY FRI MORNING. THE
STRONGEST WLY 850MB WINDS AND LLVL MSTR WILL SHIFT EWD AND EXIT
SERN PA BTWN 12-15Z...ALONG WITH THE LEADING FRONTAL BOUNDARY.
OVERNIGHT MINS SHOULD BE VERY MILD AND LKLY STAY AOA 75F IN THE
HARRISBURG/YORK/LANCASTER METRO AREA.
UPPER TROF AXIS IS EXPECTED TO SHIFT EWD ACRS THE OH VLY INTO THE
CENTRAL APPALACHIANS ON FRIDAY. DESPITE WEAKER INSTABILITY/LOWER
DEWPOINTS...THERE IS A RELATIVELY LOW THREAT FOR SCT STG TO
PERHAPS SVR STORMS TO DEVELOP IN ADVANCE OF THE MID-UPPER TROF.
MODEST DEEP LYR SHEAR SUGGESTS SOME LOOSELY ORGANIZED CLUSTERS MAY
FORM...MAINLY OVR THE SRN 1/2 OF THE AREA WHERE SPC HAS DRAWN IN A
D3 CATEGORICAL SEE TEXT.
THE PERIOD FROM SAT-WED WILL FEATURE A NEARLY STAGNANT LG SCALE
PATTERN OVR THE LOWER 48...WITH TROUGHING OVER THE ERN U.S.
EXTENDING SWD FM HUDSON BAY UPPER LOW. THE MODELS AND ENSEMBLES
SHOW GOOD AGREEMENT ON THIS SYNOPTIC PATTERN. TEMPS SHOULD AVG
NEAR NORMAL INTO THE MIDDLE OF NEXT WEEK.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
WIDESPREAD VFR CONDS ACROSS CENTRAL PA AT 06Z. HOWEVER...TSRA
ASSOCIATED WITH AN APPROACHING WARM FRONT COULD POTENTIALLY AFFECT
PORTIONS OF THE AREA BTWN 09Z-13Z. UNCERTAINTY TOO HIGH TO MENTION
EXPLICITLY IN FCST AT THIS TIME. HOWEVER...UPSTREAM RADAR LOOP AND
LATEST MDL DATA SUGGEST BFD IS THE MOST LIKELY AIRFIELD TO
EXPERIENCE A GUSTY TSRA WITH REDUCED VSBYS THIS MORNING. STRONG SW
WINDS ALOFT...COMBINED WITH MUCH LIGHTER SFC WINDS...WILL LIKELY
RESULT IN A PERIOD OF LLWS AT MOST LOCATIONS EARLY THIS MORNING.
AS WARM FRONT PUSHES NORTH OF THE AREA BTWN 13Z-15Z...EXPECT
AN INCREASINGLY GUSTY SW SFC WIND AND DIMINISHING LLWS. BUFKIT
SOUNDINGS SUPPORT FREQUENT GUSTS LATER TODAY BTWN 20-25KTS.
BIG CONCERN THIS AFTN AND EVENING WILL BE THE POSSIBILITY OF
STRONG THUNDERSTORMS DEVELOPING AHEAD OF COLD FRONT PUSHING SE
ACROSS THE GRT LKS. ALTHOUGH VFR CONDS SHOULD PREDOMINATE OVER
THE AREA THIS AFTN...THERE IS A GOOD CHC FOR A BRIEF VIS/CIG
REDUCTION ACCOMPANYING A GUSTY TSRA. MOST LIKELY TIME FRAME FOR
TSRA WILL BE 18Z-00Z AT BFD AND BTWN 20Z-02Z AT IPT/UNV/AOO/JST.
MDT AND LNS COULD EXPERIENCE AN EVENING TSRA...ALTHOUGH CHANCES
NOT AS GREAT THERE.
OUTLOOK...
FRI...AM LOW CIGS POSSIBLE W MTNS. ISOLD PM TSRA IMPACTS POSSIBLE.
SAT...AM FOG POSSIBLE. ISOLD PM TSRA IMPACTS POSSIBLE.
SUN...AM FOG POSSIBLE.
MON...ISOLD PM TSRA IMPACTS POSSIBLE.
&&
.EQUIPMENT...
STATE COLLEGE RADAR HAS BEEN RETURNED TO SERVICE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
PAZ026>028-034>036-049>052-056-057-059-063>066.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...STEINBUGL
LONG TERM...STEINBUGL
AVIATION...FITZGERALD
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
114 AM EDT THU JUL 26 2012
.SYNOPSIS...
A WEAK UPPER LEVEL RIDGE OF HIGH PRESSURE WILL PERSIST OVER THE
REGION TONIGHT THROUGH THURSDAY BRINGING VERY WARM AND MUGGY
CONDITIONS. A COLD FRONT IS EXPECTED TO MOVE ACROSS THE CAROLINAS
AND NORTHEAST GEORGIA LATE FRIDAY AND INTO SATURDAY. ANOTHER RIDGE
OF HIGH PRESSURE BUILDS BACK IN SUNDAY AND REMAINS THROUGH EARLY
NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 110 AM...QUIET TREND CONTINUES WITH SCT SKIES ACROSS MOST OF
THE CWA. ONLY MINOR TWEAKS WERE MADE FOR OVERNIGHT CONDITIONS.
AS OF 1025 PM...OTHER THAN A FEW LINGERING SHRA OVER THE FRENCH
BROAD VALLEY...THE RADAR IS CLEAR. CANNOT COMPLETELY RULE OUT
ANOTHER SHOWER OR TWO OVER THE MTNS TONIGHT...BUT SHUD BE PRECIP
FREE AFTER MIDNIGHT. CIRRUS WILL SLOWLY DIMINISH OVERNIGHT AS WELL
WITH PATCHY FOG ON THE INCREASE. MAIN UPDATES WERE FOR CURRENT
CONDITIONS.
AS OF 755 PM...CONVECTION RAPIDLY DIMINISHING ACROSS THE AREA AND
SHUD END WELL BEFORE MIDNIGHT. HOWEVER...AN ISOLATED CELL CANNOT BE
RULED OUT BEFORE THEN. CLOUDS DIMINISH OVERNIGHT WITH PATCHY FOG
DEVELOPING OUTSIDE OF THE MTNS...WITH PATCHY DENSE FOG IN THE MTN
VALLEYS. LOWS STILL EXPECTED TO BE ABOVE NORMAL.
AS OF 430 PM...CONVECTION FINALLY TAKING OFF ACROSS NC WITH SCT
COVERAGE THERE AND ISOLATED OVER THE UPSTATE. EXPECT SCT COVERAGE
ALL AREAS FOR THE REST OF THE AFTERNOON...WITH SLIGHTLY BETTER
COVERAGE OVER THE NC PIEDMONT. STORMS BECOME ISOLATED ACROSS THE
MTNS BY EARLY EVENING...THEN TAPER OFF FROM NORTH TO SOUTH BY
MIDNIGHT. OTHERWISE...MAIN ADJUSTMENTS WERE FOR CURRENT CONDITIONS.
SO FAR THE WORKED-OVER AIRMASS BEHIND THIS MORNING/S MCS HAS NOT
SPAWNED ANY NEW CONVECTION. HOWEVER...THE CU FIELD IS BECOMING
BETTER DEFINED AND RAP SOUNDINGS SHOW VERY HIGH SURFACE-BASED CAPE
VALUES...PARTICULARLY ALONG AND JUST EAST OF THE BLUE RIDGE.
THEREFORE IT SHOULDN/T BE TOO MUCH LONGER BEFORE CONVECTION BEGINS
TO DEVELOP OVER THE HIGH TERRAIN. THE DEEP LAYER SHEAR IS ABOUT 20
KTS FROM THE NORTHEAST...AND ANY CELLS THAT DO DEVELOP SHOULD DRIFT
INTO THE FOOTHILLS AND POSSIBLY THE WESTERN PIEDMONT. THE WRF-ARW
AND 4KM SPC WRF-NMM ARE BOTH ALREADY WAY OVERDONE WITH CONVECTION
OVER THE REGION...THOUGH THEY DO INSIST THAT VIGOROUS DEVELOPMENT
WILL OCCUR.
THE BOTTOM LINE IS THAT I/LL CONTINUE TO CARRY CHANCE POPS THE REST
OF THE AFTN AND EVENING HOURS...WITH THE HIGHEST POPS ACROSS THE
MTNS AND THE LOWEST ACROSS THE PIEDMONT. HOWEVER...WITH SUCH AN
UNSTABLE ATMOSPHERE AND SEVERAL WEAK BNDRY/S OVER THE REGION IT/S
ENTIRELY POSSIBLE THAT SCATTERED STORMS...ONCE THEY FORM...WILL WORK
SOUTHEASTWARD ACROSS MUCH OF THE REGION DURING THE EVENING HOURS. A
FEW SEVERE STORMS ARE A GOOD BET ONCE THEY START TO FIRE.
THE ATMOSPHERE WILL WARM UP CONSIDERABLY TOMORROW AS THE CENTER OF A
HOT DEEP LAYER RIDGE MOVES ACROSS THE REGION. HEAT INDEX VALUES
SHOULD RISE INTO THE HEAT ADVISORY CRITERIA RANGE FOR SEVERAL HOURS
IN THE AFTERNOON ACROSS THE CHARLOTTE METRO AREA...THE SOUTHERN
UPSTATE AND IN ELBERT COUNTY GEORGIA. CLOSER TO THE MOUNTAINS
DEWPOINTS ARE EXPECTED TO MIX OUT ENOUGH IN THE AFTERNOON TO KEEP
THE HEAT INDEX BELOW ADVISORY CRITERIA. WITH WARMING MID LEVEL
TEMPS...VERY LITTLE SHEAR AND DEWPOINTS MIXING OUT DURING THE
AFTN...CONVECTION IS EXPECTED TO BE ISOLATED AND MAINLY CONFINED TO
THE MOUNTAINS.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
AS OF 230 PM EDT WEDNESDAY...ON FRIDAY...A COLD FRONT WITH ACTIVE
PRE-FRONTAL CONVECTION IS EXPECTED OVER MIDDLE KY/TN DURING THE PRE
DAWN HOURS. THE FRONT AND PRE-FRONTAL TROF WILL APPROACH THE
SOUTHERN APPALACHIAN REGION DURING THE MORNING AS A L/W TROF DEEPENS
OVER THE MID WEST. CONVECTION IS EXPECTED OVER THE MTNS BY MID DAY...PUSHING
EAST OF THE MTNS DURING THE AFTERNOON AND EVENING. THE ENVIRONMENT
AHEAD OF THE CONVECTIVE BAND WILL FEATURE LLVL BULK SHEAR VALUES
APPROACHING 20 KTS WITH CAPE RANGING FROM 1500 TO 2000 J/KG. A FEW
ORGANIZED STORM CLUSTERS MAY DEVELOP ALONG AND AHEAD OF THE
FRONT...POSSIBLY YIELDING DAMAGING WINDS AND HAIL.
THE LATE DAY PASSAGE OF CONVECTION SHOULD ALLOW HIGH TEMPERATURES TO
REACH THE U90S EAST OF THE MTNS. RETURN FLOW AHEAD OF THE FRONT WILL
SUPPORT DEWPOINT VALUES IN THE U60S. THE COMBINATION OF THE HOT
TEMPERATURES AND MODERATE HUMIDITY SHOULD YIELD HEAT INDEX VALUES
ALONG AND EAST OF I-85 TO REACH NEAR 105 DURING THE LATE AFTERNOON.
HEAT ADVISORY CRITERIA MAY BE REACHED EAST OF I-85.
ON SATURDAY...THE CWA SHOULD REMAIN LARGELY IN A POST FRONTAL
ENVIRONMENT...WITH NW LLVL WINDS. DOWNSLOPE FLOW AND LINGERING MILD
THICKNESSES WILL SUPPORT HIGHS IN THE U80S ACROSS THE MTN VALLEYS
AND MID 90S ALONG AND EAST OF I-85. DEWPOINTS MAY ALSO DECREASE A
FEW DEGREES IN THE WAKE OF THE FRONT. FORECAST SOUNDINGS
CONTINUE TO SHOWS CAPE VALUES AROUND 2000 J/KG DURING THE
AFTERNOON. HOWEVER...A SHALLOW LAYER OF CIN MAY EXIST BELOW THE LFC
AND AND AN WEAK INVERSION WITHIN THE MID LEVEL MAY LIMIT DEEP
CONVECTION. GIVEN THE INSTABILITY AND THE PASSAGE OF THE MID LEVEL
TROF I WILL ADVERTISE SCHC POPS DURING THE AFTERNOON. IF CONVECTION
DOES DEVELOP...THETA-E LAPSE RATES IN THE MID 30S COULD SUPPORT A
DAMAGING WET MICROBURST.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 200 PM EDT WEDNESDAY...THE LATEST MODELS CONTINUE TO
INDICATE THAT THE UPPER TROUGH PERSISTS OVER THE EASTERN CONUS AND A
BROAD UPPER LEVEL RIDGE OF HIGH PRESSURE REMAIN IN PLACE OVER THE
GREAT PLAINS THROUGH THE EXTENDED FORECAST PERIOD. AT THE
SURFACE...A FAIRLY STRONG HIGH PRESSURE IS EXPECTED TO BUILD ACROSS
THE REGION FROM THE NORTH BY LATE SATURDAY AND REMAINS THROUGH
SUNDAY FOR MOSTLY DRY WEATHER WITH SEASONABLY WARM TEMPERATURES. AS
THE HIGH MOVES OFF TO THE EAST MONDAY...A SURFACE LOW PRESSURE IS
EXPECTED TO DEVELOP OVER THE CAROLINAS AND LINGERS INTO WEDNESDAY.
THIS WILL RESULT IN UNSETTLED WEATHER PATTERN AND COOLER
TEMPERATURES ACROSS MUCH OF OUR CWA. TEMPERATURES WILL REMAIN
NEAR...OR A COUPLE DEGREES ABOVE NORMAL THROUGH TUESDAY WITH
AFTERNOON HIGHS IN THE LOW 90S OVER THE PIEDMONT. TEMPERATURES WILL
DROP 5-10 DEGREES BY WEDNESDAY WITH HIGHS IN THE MID 80S OVER THE
PIEDMONT AND 70S MTNS.
&&
.AVIATION /05Z THURSDAY THROUGH MONDAY/...
AT KCLT...AS UPPER RIDGE BUILDS OVER THE REGION EXPECT MCLR SKIES
OVERNIGHT WITH BRIEF TEMPO MVFR VSBY AROUND DAYBREAK. LGT SW WINDS
WILL INCREASE TO 10KT WITH SCT CU THIS AFTN.
ELSEWHERE...SIMILAR CONDITIONS TO KCLT EXCEPT FOR TEMPO IFR FOG AT
KAVL AROUND DAYBREAK. LOW END CHC POPS SHOULD REMAIN LIMITED TO THE
MTNS THIS AFTN.
OUTLOOK...CHANCE FOR CONVECTION WILL INCREASE FRI AS A SHORTWAVE AND
ASSOC COLD FRONT MOVE IN. THEN EXPECT AT LEAST SLIGHT CHC POPS INTO
THE MIDDLE OF NEXT WEEK AS UPPER TROF REMAINS OVER THE E COAST.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...HEAT ADVISORY FROM NOON TODAY TO 7 PM EDT THIS EVENING FOR
GAZ029.
NC...HEAT ADVISORY FROM NOON TODAY TO 7 PM EDT THIS EVENING FOR
NCZ071-072-082.
SC...HEAT ADVISORY FROM NOON TODAY TO 7 PM EDT THIS EVENING FOR
SCZ009-011>014-019.
&&
$$
SYNOPSIS...JOH
NEAR TERM...MCAVOY/RWH/RB
SHORT TERM...NED
LONG TERM...JOH
AVIATION...RB
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1230 AM CDT THU JUL 26 2012
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...VFR CONDITIONS WILL PERSIST THROUGH THE NEXT 24 HOURS.
GENERALLY MODERATE WINDS ARE LIKELY AS HIGH PRESSURE OVER THE GULF
OF MEXICO INTERACTS WITH LOW PRESSURE OVER NORTHERN MEXICO. A WEAK
DISTURBANCE IN THE MIDDLE LAYERS OF THE ATMOSPHERE THAT RECENTLY
DEVELOPED OVER THE WESTERN GULF OF MEXICO MAY PRODUCE INCREASED
CLOUD COVER OVER DEEP SOUTH TEXAS AND THE RIO GRANDE VALLEY...
ESPECIALLY TOMORROW.
&&
.PREV DISCUSSION... /ISSUED 627 PM CDT WED JUL 25 2012/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...HAVE MAINTAINED VFR CONDITIONS FOR THE NEXT 24 HOURS.
SURFACE WINDS WILL ONCE AGAIN PICK UP DURING THE DAY...ESPECIALLY
AS DAYTIME HEATING KICKS IN...AS WILL THE CLOUD COVER. THE BIG
QUESTION IN THE SHORT TERM REMAINS THE INFLUENCE OF A CONVECTIVE
COMPLEX THAT IS JUST OFFSHORE OF THE MEXICAN COASTLINE BETWEEN
TAMPICO AND BROWNSVILLE. MODELS HINT AT A VORT MAX MOVING NORTH
THURSDAY AND THURSDAY NIGHT...ALLOWING FOR ISOLATED TO SCATTERED
CONVECTION. AT THIS TIME AM NOT CONFIDENT THAT CONVECTION WILL
IMPACT REGIONAL AIRPORTS AND AS SUCH HAVE NOT MENTIONED ANY
CONVECTION IN THE TAF PACKAGE.
PREV DISCUSSION... /ISSUED 211 PM CDT WED JUL 25 2012/
SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...THE MAIN CONCERN IN
THE SHORT TERM IS THE POTENTIAL INFLUENCE OF THE CONV COMPLEX THAT
HAS BEEN FIRING TODAY JUST OFFSHORE OF THE MEXICAN COASTLINE BETWEEN
BRO AND TAMPICO. BOTH THE RUC AND NAM PICK UP ON A MID LEVEL VORT
LIKELY INDUCED BY THIS CONV AND MOVE IT NORTHWARDS STEADILY THROUGH
THURS AND THURS NIGHT. THE UPPER LEVEL SUPPORT FROM THIS FEATURE
WILL COMBINE WITH THE FAIRLY ELEVATED CAPE VALUES EVIDENT FROM THE
CURRENT LAPS FIELDS AND THE 12Z BRO SOUNDING TO SET THE STAGE FOR
THE FORMATION OF ISOLD TO SCT CONV MAINLY ALONG AND JUST OFFSHORE OF
THE LOWER TX COASTLINE LATER TONIGHT INTO THURSDAY NIGHT.
THE NAM AND RUC GUIDANCE BOTH TRY TO PICK UP ON THE MID LEVEL VORT
LOCATED NEAR THE HEART OF THE CONV AND ADVECT IT STEADILY NORTHWARDS
ALONG OR JUST OFFSHORE OF THE SOUTH TX COASTLINE. THE GFS ALSO PICKS
UP ON THIS FEATURE AND MOVES IT NORTH TOWARDS THE LOWER TX COASTLINE
BUT UNDERPLAYS THE OVERALL DEEPER LAYER MOISTURE POOL OVER THE
REGION. SO GFS HAS LITTLE OR NO POPS FOR THE REGION WHILE THE NAM
BUILDS UP SOME HIGHER POPS NEAR THE LOWER TX COASTLINE. WILL BE
GOING WITH THE NAM GUIDANCE FOR BOTH TEMPS AND POPS SINCE THIS MODEL
APPEARS TO BE INITIALIZING THE BEST ON THIS CONV COMPLEX.
LONG TERM /FRIDAY THROUGH TUESDAY/...
AT THE ONSET OF THE LONG TERM PERIOD UPPER RIDGING BEGINS TO BUILD
OVER THE SOUTHEASTERN ROCKY MOUNTAIN REGION AND SHIFT MORE TOWARDS
THE CENTRAL PLAINS...WHILE AT THE SURFACE RELATIVELY STRONG RIDGING
IS PROGGED TO BE CENTERED OVER THE EAST CENTRAL GULF OF MEXICO AND
THE NORTHERN PLAINS. WEAK LEE TROUGHING IN RESPONSE TO A WEAK
RETREATING UPPER LOW MAY REMAIN PRESENT ENOUGH FRIDAY TO ALLOW FOR
ONE MORE BREEZIER THAN NORMAL DAY BUT THAT SHOULD QUICKLY REMOVE
ITSELF AS A PLAYER FROM OUR WEATHER PATTERN BY SATURDAY.
THE OVERALL THEME OF THE PATTERN WILL CONTINUE TO BE WARM...POSSIBLY
HOT...AND DRY. WINDS SHOULD BE FAIRLY STEADY AND SEASONABLE OUT OF
THE SOUTHEAST AT 10 TO 15 MPH IN THE AFTERNOON. PWAT VALUES REMAIN
FAIRLY LOW AND A SUBSIDENCE INVERSION WILL LIKELY SET UP IN SOME
FORM IN RESPONSE TO THE BUILDING RIDGING OVER NORTHERN TEXAS AND THE
CENTRAL PLAINS. THE BEST WINDOW FOR ANY PRECIP FOR NOW LOOKS TO BE
SUNDAY IN THE AFTERNOON HOURS AS GFS40/ECMWF BOTH SLIDE A LITTLE BIT
OF TROPICAL MOISTURE ASSOCIATED WITH A WEAK WAVE IN VIA A WEAKNESS
IN THE RIDGE TO THE EAST AND OUR NORTH. DID ADD SOME SCHC SHRA/TSRA
TO THIS PERIOD GIVEN THE REASONABLE CONSENSUS ON TIMING FROM EC/GFS.
A PRIMARY CONCERN IN THIS PERIOD MAY BE PROLONGED ABOVE NORMAL
TEMPERATURES. DEEP LAYER AND LOW LEVEL THICKNESSES WILL BE QUITE
HIGH WITH STRONG INSOLATION AMID FEW TO SCATTERED CLOUDS. THE
SURFACE FLOW IS PROJECTED TO BE A LITTLE MORE SOUTHEASTERLY THAN
SOUTHERLY...BUT A FEW VERY HOT DAYS WILL BE POSSIBLE GIVEN THE
STRENGTH OF THE RIDGE. BUMPED UP TEMPERATURES SLIGHTLY FROM THE
GOING FORECAST WHICH CONTINUES TO SIT A LITTLE ABOVE GUIDANCE
CONSENSUS. HEAT INDICIES FROM 105 TO 110 WILL BE VERY MUCH IN PLAY
DURING THE SUNDAY TO WEDNESDAY PERIOD...WITH HEAT ADVISORY CRITERIA
HEAT INDICIES POSSIBLE.
MARINE /TONIGHT THROUGH THURSDAY NIGHT/...CURRENTLY THE PGF ALONG
THE LOWER TX BAY AND GULF WATERS HAS PUSHED CONDITIONS UP INTO SCEC
LEVELS THIS AFTERNOON. EXPECT THIS PGF TO PERSIST THROUGHOUT THE
SHORT TERM PERIOD KEEPING THE BAY AND GULF WATERS CLOSE TO
SCEC/BORDERLINE SCA CRIT THROUGH TOMORROW NIGHT. THE MARINE CONV
PUSHING UP FROM THE SOUTH MAY BRIEFING BOOST THE WINDS AND SEAS UP
CLOSE TO SMW CRIT DUE TO THE CONV OUTFLOW. HOWEVER WILL NOT POST ANY
SCAS AT THIS TIME.
FRIDAY THROUGH SUNDAY....
PERSISTENT MODERATE SOUTHEASTERLY WINDS ARE EXPECTED DURING THE
PERIOD. THE STRONGEST WINDS FOR NOW ARE EXPECTED ON FRIDAY. SCEC
CONDITIONS ON THE LAGUNA IN THE AFTERNOON AND THE EVENING IN THE
OFFSHORE WATERS ARE POSSIBLE DURING THIS TIME. WINDS AND SEAS SHOULD
STAY BELOW SCEC CRITERIA SATURDAY AND SUNDAY WITH SEAS GENERALLY
EXPECTED TO BE BETWEEN THREE AND FIVE FEET.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1039 PM PDT Wed Jul 25 2012
.SYNOPSIS...
Low pressure off and along the coast propped up against higher
pressure in the vicinity of the Northern Rockies will keep a very
minor southwest to northeast oriented storm track in the vicinity
of Eastern Washington and Northern Idaho into next week. This
pattern will should result in near normal temperatures through
much of this and the following workweek.
&&
.DISCUSSION...
Update for tonight...Surface instability with uncapped CAPE around
1000 J/KG earlier today trigger scattered showers and isolated
thunderstorms over the northern mountains. With the loss of
daytime heating these are winding down although water vapor does
show a weak wave over the Washington Cascades that will be moving
north tonight. This in combination with mid level instability will
result in a chance for isolated showers persisting through the
night mainly north of Lake Chelan. Thus the forecast was updated
earlier to add this to the forecast. Another wave across Oregon
will be approaching Southeast Washington and southern Idaho
Panhandle late tonight into Thursday morning. Given very little activity
convection wise this evening and that HRRR shows no convection
through 14z (7 am) with this wave will continue the idea of mid
level ACCUS clouds moving across the Palouse, Lewiston area,
Blues, and Camas Prairie Thursday morning with no shower or
thunderstorm activity expected. Another round of thunderstorms is
still expected Thursday afternoon over the northern mountains
especially in the Cascades. JW
&&
.AVIATION...
06Z TAFS: A very weak wave track out of northeast Oregon Thursday
morning into Southeast Washington and the south Idaho Panhandle. Mid
and upper levels are expected to destabilize which may lead to some
elevated convection and isolated thunderstorms, but confidence is
low at this time due to only weak forcing. We are more likely to
just get ACCAS clouds with possible sprinkles. This activity will
move across KLWS and KPUW taf sites between 14Z-21Z. This activity
will propagate into KGEG/KSFF/KCOE after 18z. Thunderstorms will
again develop after 18z over the mountains near the Canadian border
especially in the Cascades. JW
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 63 89 62 87 59 84 / 0 10 10 20 20 0
Coeur d`Alene 57 88 58 87 56 84 / 0 0 10 20 20 0
Pullman 52 88 56 87 53 83 / 0 10 10 20 20 0
Lewiston 64 95 66 94 63 91 / 0 10 10 20 20 0
Colville 56 91 58 90 56 87 / 10 10 10 20 20 10
Sandpoint 53 86 53 85 52 81 / 0 10 10 20 20 0
Kellogg 54 88 58 86 55 81 / 0 10 10 20 20 10
Moses Lake 61 93 62 92 58 88 / 0 0 0 0 10 0
Wenatchee 66 93 66 90 63 87 / 0 0 0 0 10 0
Omak 61 92 60 92 57 88 / 10 10 20 20 20 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
913 PM PDT Wed Jul 25 2012
.SYNOPSIS...
Low pressure off and along the coast propped up against higher
pressure in the vicinity of the Northern Rockies will keep a very
minor southwest to northeast oriented storm track in the vicinity
of Eastern Washington and Northern Idaho into next week. This
pattern will should result in near normal temperatures through
much of this and the following workweek.
&&
.DISCUSSION...
Update for tonight...Surface instability with uncapped CAPE around
1000 J/KG earlier today trigger scattered showers and isolated
thunderstorms over the northern mountains. With the loss of
daytime heating these are winding down although water vapor does
show a weak wave over the Washington Cascades that will be moving
north tonight. This in combination with mid level instability will
result in a chance for isolated showers persisting through the
night mainly north of Lake Chelan. Thus the forecast was updated
earlier to add this to the forecast. Another wave across Oregon
will be approaching Southeast Washington and southern Idaho
Panhandle late tonight into Thursday morning. Given very little activity
convection wise this evening and that HRRR shows no convection
through 14z (7 am) with this wave will continue the idea of mid
level ACCUS clouds moving across the Palouse, Lewiston area,
Blues, and Camas Prairie Thursday morning with no shower or
thunderstorm activity expected. Another round of thunderstorms is
still expected Thursday afternoon over the northern mountains
especially in the Cascades. JW
&&
.AVIATION...
00Z TAFS: Surface based convection across the northern mountains
will dissipate with sunset this evening as well as the shallow
cumulus over the basin. A very weak wave will cross through the
region out of northeast Oregon Thursday morning into the afternoon
(after 15Z). Mid and upper levels are expected to destabilize across
eastern WA and into the Idaho Panhandle as this wave moves south to
north across the region. This may lead to some elevated convection
and isolated thunderstorms, but confidence is low at this time due
to only weak forcing. We may only get some ACCAS with some light
rain or sprinkles. At this point, placed the best chance, albeit low
chances, at the KLWS and KPUW taf sites between 17Z-21Z. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 63 89 62 87 59 84 / 0 10 10 20 20 0
Coeur d`Alene 57 88 58 87 56 84 / 0 0 10 20 20 0
Pullman 52 88 56 87 53 83 / 0 10 10 20 20 0
Lewiston 64 95 66 94 63 91 / 0 10 10 20 20 0
Colville 56 91 58 90 56 87 / 10 10 10 20 20 10
Sandpoint 53 86 53 85 52 81 / 0 10 10 20 20 0
Kellogg 54 88 58 86 55 81 / 0 10 10 20 20 10
Moses Lake 61 93 62 92 58 88 / 0 0 0 0 10 0
Wenatchee 66 93 66 90 63 87 / 0 0 0 0 10 0
Omak 61 92 60 92 57 88 / 10 10 20 20 20 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1005 AM EDT THU JUL 26 2012
.DISCUSSION...
THE H100-H70 RIDGE AXIS EXTENDING FROM THE NRN BAHAMAS INTO THE
CENTRAL GOMEX BASED ON LATEST RAP ANALYSIS. MORNING SOUNDINGS SHOW
MOISTURE DECREASING FROM N TO S ACRS THE FL PENINSULA: PWATS ARND
1.9" AT KJAX...DECREASING TO ARND 1.4" S OF KXMR-KTBW. LOW/MID LVL
MOISTURE QUITE LOW WITH H100-H85 MEAN RH VALUES HOVERING ARND
70PCT...H85-H50 VALUES AOB 45PCT. STRONG SUBSIDENCE INVERSIONS NOTED
IN THE H90-H80 LYR ON CENTRAL/S FL AND NRN BAHAMA SOUNDINGS. THIS IS
WELL REFLECTED IN THE REGIONAL MID LVL THERMAL PROFILE WITH H70
TEMPS ARND 10C...H50 TEMPS BTWN -5C AND -6C.
POSITION OF THE RIDGE AXIS WILL MAINTAIN A WARM SWRLY FLOW ACRS
CENTRAL FL THIS AFTN. TEMP/MOISTURE PROFILE INDICATES MINIMAL PRECIP
CHANCES. ANY CONVECTION WILL BE BRIEF AND LIMITED TO AREAS N OF THE
I-4 CORRIDOR WHERE LOW/MID LVL MOISTURE WILL BE HIGHEST AND MID LVL
TEMPS LOWEST. EVEN SO...THE LOW LVL THERMAL CAP WILL BE DIFFICULT TO
BREAK THRU WITHOUT MESOSCALE BOUNDARY INTERACTIONS...AND THE EAST
COAST SEA BREEZE LIKELY WILL BE SUPPRESSED N OF I-4 DUE TO A
STRONGER WIND FIELD.
MRNG PACKAGE LOOKS GOOD WITH BLO 20 POPS ALONG AND N OF I-4. DRY
AIR...LACK OF PRECIP...AND SWRLY FLOW WILL COMBINE TO PUSH MAX TEMPS
M90S OVER MOST OF THE CWA...L90S ALONG THE IMMEDIATE COAST S OF THE
CAPE WHERE THE SEA BREEZE FORMS. DEWPOINTS IN THE M/U70S WILL
COMBINE WITH THESE TEMPS TO EASILY PUSH HEAT INDICES INTO THE
100-105 RANGE. NO UPDATES PLANNED THIS MORNING.
&&
.AVIATION...
THRU 26/18Z...BRIEF MVFR CIGS BTWN FL015-025 ALL SITES...AREAS MVFR
VSBYS IN HZ E OF KMLB-OBE.
BTWN 26/18Z-26/24Z...ISOLD MVFR SHRAS/IFR TSRAS N OF KEVB-KBKV.
AFT 27/00Z...VFR ALL SITES.
&&
.MARINE...
NO HIGHLIGHTS...NO SIG CHANGES. ATLC RIDGE AXIS OVER S FL WILL
GENERATE A GENTLE TO MODERATE SW BREEZE THRU EARLY AFTN. SFC/BNDRY
LYR WNDSHFT TO S/SE BY EARLY AFTN AS THE EAST COAST SEA BREEZE DVLPS
AND DRIFTS INLAND. SEAS AOB 2FT NEARSHORE...2-3FT OFFSHORE. DOMINANT
PDS ARND 13SEC.
&&
.CLIMATE...
RECORD HIGHS FOR THU JULY 26:
DAYTONA BEACH 97 1992
ORLANDO 98 1936, 1914
MELBOURNE 98 1983
VERO BEACH 97 1983
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECAST/AVIATION.......BRAGAW
RADAR WATCH/IMPACT WX...LASCODY
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1044 AM CDT THU JUL 26 2012
.DISCUSSION...
ISSUED 1044 AM CDT THU JUL 26 2012
OUTFLOW BOUNDARY FROM OVERNIGHT CONVECTION CLEARED THE FORECAST
AREA TO THE SOUTHEAST...WITH WINDS AT LEAST BRIEFLY SHIFTING TO
THE NORTHWEST. HOWEVER...THE FURTHER SOUTHEAST YOU GO...THE LESS
IMPACT THIS OUTFLOW HAS HAD ON TEMPERATURES. TEMPERATURES IN THE
NORTHWEST PORTION OF THE FORECAST AREA ARE IN THE 70S...WHILE
TEMPERATURES HAVE CLIMBED INTO THE 90S IN THE SOUTHEAST. FAIRLY
EXTENSIVE CLOUD COVER ASSOCIATED WITH THE EARLIER CONVECTION
EXTENDS FROM THE GREAT LAKES INTO THE SOUTHERN PLAINS IN
ALONG/AHEAD OF A SLOWLY ADVANCING COLD FRONT.
MAIN CONCERN TODAY IS HOW MUCH THE ATMOSPHERE CAN RECOVER IN THE
WAKE OF THE EARLIER OUTFLOW. SPC MESOANALYSIS SHOWS PRETTY STOUT
CAPPING STILL IN PLACE FOR SURFACE BASED CONVECTION...AND WE MAY
HAVE TROUBLE ERODING THIS CAP DUE TO THE EXPANSIVE CLOUD COVER
THAT DOES NOT APPEAR TO BE GOING ANYWHERE QUICKLY. THE BEST CHANCE
FOR STORM DEVELOPMENT REMAINS IN THE SOUTHEAST HALF OF THE
FORECAST AREA WHERE TEMPERATURES WERE NOT IMPACTED AS MUCH AS
FURTHER TO THE NORTHWEST.
WILL UPDATE FORECAST TO LOWER POPS FOR MOST OF THE FORECAST
AREA...DUE TO THE CAPPING AND LIMITED TIME FOR RECOVERY DUE TO THE
CLOUD COVER. HAVE ALSO MADE TWEAKS TO MOST OTHER PARAMETERS FOR
THE LATEST TRENDS.
BAK
&&
.AVIATION...
ISSUED 655 AM CDT THU JUL 26 2012
FORECAST COMPLICATIONS ARE MULTIPLE BOUNDARIES...OUTFLOWS...AND
SCT PRECIP ON SAT IMAGERY FALLING APART AS IT RUNS INTO DRY AIR
OVER CENTRAL ILLINOIS. CONFIDENCE IN ANY MODEL SOLUTION FOR PRECIP
IS MINIMAL AS MOST OF THEM ARE COMING IN TOO WET. REFIRE OF ANY
MESO OR SYNOPTIC SCALE BOUNDARIES THROUGH THE AFTERNOON IS ALLUDED
TO...BUT NOTHING HAS HIGH ENOUGH CONFIDENCE TO GO WITH IT JUST
YET. SO FORECAST REMAINS AN ISSUE OF WINDS FROM SW TO NW...AND MID
LEVEL CLOUDS. SOME CU DEVELOPMENT EXPECTED UNDER THE AC AS WELL.
HJS
&&
.PREV DISCUSSION...
ISSUED 315 AM CDT THU JUL 26 2012
SERIES OF MCS SYSTEMS LINED UP FROM KANSAS TO LOWER MICHIGAN HAS
BEEN WEAKENING THE LAST COUPLE HOURS. HAVE MANAGED TO GET A FEW
STORMS FIRING IN THE ILLINOIS DESERT ALONG AN OUTFLOW BOUNDARY...
WHICH STRETCHED FROM PITTSFIELD TO PONTIAC AT 2 AM. SOME GUSTS TO
35-40 MPH OCCURRED ALONG THIS BOUNDARY...WITH HIGHER SPEEDS IN
NORTHERN ILLINOIS. HOWEVER...MUCH OF THE LARGER RAIN SHIELD HAS
BEEN DIMINISHING AS IT APPROACHES WEST CENTRAL ILLINOIS. THE
PRIMARY COLD FRONT EXTENDED FROM THE TEXAS PANHANDLE TO LOWER
MICHIGAN...WITH A SECONDARY BOUNDARY FROM NORTHWEST KANSAS TO THE
MINNESOTA ARROWHEAD.
SHORT TERM...TODAY THROUGH SATURDAY...
PRIMARY FORECAST CONCERN DURING THIS PERIOD INVOLVES CONVECTIVE
REDEVELOPMENT TODAY. LATEST HRRR MODEL SHOWS A WEAKENING TREND
CONTINUING WITH THE EXISTING CONVECTION AS IT MOVES THROUGH
ILLINOIS. ADDITIONAL DEVELOPMENT SHOULD START FIRING TOWARD MIDDAY
AS THE MAIN COLD FRONT APPROACHES SOUTHEAST ILLINOIS TOWARD EARLY
AFTERNOON. ENTIRE CWA IS UNDER A SLIGHT RISK OF SEVERE WEATHER FOR
TODAY...HOWEVER THE BETTER CHANCES WILL BE CLOSER TO THE I-70
CORRIDOR AHEAD OF THE FRONT...WHERE THE ATMOSPHERE WILL BE LESS
OVERTURNED BY THE EARLY MORNING CONVECTION. LATEST NAM MODEL
PROJECTS 3000 J/KG OF CAPE IN THIS AREA BY THE TIME THE FRONT
ARRIVES. MOST OF THE RAIN SHOULD BE OUT OF THE AREA BY EARLY
EVENING...BUT WILL LINGER SOME SMALL POPS EAST OF I-57 INTO
EVENING. SOME ADDITIONAL SHOWERS AND STORMS WILL OCCUR OVER
PORTIONS OF THE MIDWEST FRIDAY...AS THE UPPER TROUGH SWINGS
THROUGH THE GREAT LAKES...BUT THESE WILL LIKELY REMAIN JUST TO OUR
NORTH.
TEMPERATURES TODAY WILL BE TRICKY...WITH THE RAIN AND CLOUD COVER.
AREAS SOUTHEAST OF I-70 WILL BE MOST LIKELY TO SEE HEAT INDEX
VALUES NEAR ADVISORY CRITERIA NEAR 105. WILL GO AHEAD AND ISSUE
AN ADVISORY IN THAT AREA FOR THIS AFTERNOON AND EARLY EVENING.
FOR FRIDAY...STILL AM EXPECTING TEMPERATURES INTO THE MID TO UPPER
90S IN THE SOUTHEAST CWA...BUT DRIER AIR IN THE NORTHWEST FLOW
SHOULD KEEP HEAT INDEX VALUES IN CHECK. HIGHS BY SATURDAY SHOULD
MAINLY BE IN THE 80S OVER THE ENTIRE FORECAST AREA.
LONG TERM...SUNDAY THROUGH WEDNESDAY...
UPPER RIDGING WILL PLACE ILLINOIS IN THE NORTHWEST FLOW COMING
DOWN THE TOP OF THE RIDGE THROUGH THE PERIOD. PERIODIC SHORTWAVES
IN THE FLOW WILL LEAD TO RAIN CHANCES AT TIMES...WITH SUNDAY NIGHT
THROUGH MONDAY THE BEST BET AT THE MOMENT. TEMPERATURES WILL BEGIN
TO CREEP BACK UPWARD EARLY NEXT WEEK...WITH HIGHS MAINLY IN THE
LOWER 90S.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ILZ062-063-066>068-
071>073.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
700 AM CDT THU JUL 26 2012
.DISCUSSION...
ISSUED 315 AM CDT THU JUL 26 2012
SERIES OF MCS SYSTEMS LINED UP FROM KANSAS TO LOWER MICHIGAN HAS
BEEN WEAKENING THE LAST COUPLE HOURS. HAVE MANAGED TO GET A FEW
STORMS FIRING IN THE ILLINOIS DESERT ALONG AN OUTFLOW BOUNDARY...
WHICH STRETCHED FROM PITTSFIELD TO PONTIAC AT 2 AM. SOME GUSTS TO
35-40 MPH OCCURRED ALONG THIS BOUNDARY...WITH HIGHER SPEEDS IN
NORTHERN ILLINOIS. HOWEVER...MUCH OF THE LARGER RAIN SHIELD HAS
BEEN DIMINISHING AS IT APPROACHES WEST CENTRAL ILLINOIS. THE
PRIMARY COLD FRONT EXTENDED FROM THE TEXAS PANHANDLE TO LOWER
MICHIGAN...WITH A SECONDARY BOUNDARY FROM NORTHWEST KANSAS TO THE
MINNESOTA ARROWHEAD.
SHORT TERM...TODAY THROUGH SATURDAY...
PRIMARY FORECAST CONCERN DURING THIS PERIOD INVOLVES CONVECTIVE
REDEVELOPMENT TODAY. LATEST HRRR MODEL SHOWS A WEAKENING TREND
CONTINUING WITH THE EXISTING CONVECTION AS IT MOVES THROUGH
ILLINOIS. ADDITIONAL DEVELOPMENT SHOULD START FIRING TOWARD MIDDAY
AS THE MAIN COLD FRONT APPROACHES SOUTHEAST ILLINOIS TOWARD EARLY
AFTERNOON. ENTIRE CWA IS UNDER A SLIGHT RISK OF SEVERE WEATHER FOR
TODAY...HOWEVER THE BETTER CHANCES WILL BE CLOSER TO THE I-70
CORRIDOR AHEAD OF THE FRONT...WHERE THE ATMOSPHERE WILL BE LESS
OVERTURNED BY THE EARLY MORNING CONVECTION. LATEST NAM MODEL
PROJECTS 3000 J/KG OF CAPE IN THIS AREA BY THE TIME THE FRONT
ARRIVES. MOST OF THE RAIN SHOULD BE OUT OF THE AREA BY EARLY
EVENING...BUT WILL LINGER SOME SMALL POPS EAST OF I-57 INTO
EVENING. SOME ADDITIONAL SHOWERS AND STORMS WILL OCCUR OVER
PORTIONS OF THE MIDWEST FRIDAY...AS THE UPPER TROUGH SWINGS
THROUGH THE GREAT LAKES...BUT THESE WILL LIKELY REMAIN JUST TO OUR
NORTH.
TEMPERATURES TODAY WILL BE TRICKY...WITH THE RAIN AND CLOUD COVER.
AREAS SOUTHEAST OF I-70 WILL BE MOST LIKELY TO SEE HEAT INDEX
VALUES NEAR ADVISORY CRITERIA NEAR 105. WILL GO AHEAD AND ISSUE
AN ADVISORY IN THAT AREA FOR THIS AFTERNOON AND EARLY EVENING.
FOR FRIDAY...STILL AM EXPECTING TEMPERATURES INTO THE MID TO UPPER
90S IN THE SOUTHEAST CWA...BUT DRIER AIR IN THE NORTHWEST FLOW
SHOULD KEEP HEAT INDEX VALUES IN CHECK. HIGHS BY SATURDAY SHOULD
MAINLY BE IN THE 80S OVER THE ENTIRE FORECAST AREA.
LONG TERM...SUNDAY THROUGH WEDNESDAY...
UPPER RIDGING WILL PLACE ILLINOIS IN THE NORTHWEST FLOW COMING
DOWN THE TOP OF THE RIDGE THROUGH THE PERIOD. PERIODIC SHORTWAVES
IN THE FLOW WILL LEAD TO RAIN CHANCES AT TIMES...WITH SUNDAY NIGHT
THROUGH MONDAY THE BEST BET AT THE MOMENT. TEMPERATURES WILL BEGIN
TO CREEP BACK UPWARD EARLY NEXT WEEK...WITH HIGHS MAINLY IN THE
LOWER 90S.
GEELHART
&&
.AVIATION...
ISSUED 655 AM CDT THU JUL 26 2012
FORECAST COMPLICATIONS ARE MULTIPLE BOUNDARIES...OUTFLOWS...AND
SCT PRECIP ON SAT IMAGERY FALLING APART AS IT RUNS INTO DRY AIR
OVER CENTRAL ILLINOIS. CONFIDENCE IN ANY MODEL SOLUTION FOR PRECIP
IS MINIMAL AS MOST OF THEM ARE COMING IN TOO WET. REFIRE OF ANY
MESO OR SYNOPTIC SCALE BOUNDARIES THROUGH THE AFTERNOON IS ALLUDED
TO...BUT NOTHING HAS HIGH ENOUGH CONFIDENCE TO GO WITH IT JUST
YET. SO FORECAST REMAINS AN ISSUE OF WINDS FROM SW TO NW...AND MID
LEVEL CLOUDS. SOME CU DEVELOPMENT EXPECTED UNDER THE AC AS WELL.
HJS
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR
ILZ062-063-066>068-071>073.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
652 AM CDT THU JUL 26 2012
...UPDATED FOR AVIATION...
.SYNOPSIS...
ISSUED AT 1208 AM CDT THU JUL 26 2012
AT 00Z THURSDAY A -14C 500MB UPPER LOW WAS LOCATED NEAR SOUTHERN
MANITOBA AND A 500MB UPPER RIDGE WAS PLACED ACROSS THE SOUTHWEST
UNITED STATES. AT THE 250MB LEVEL A 75KT JET WAS MOVING OVER THE
UPPER RIDGE AXIS WITH THE NOSE OF THIS UPPER JET LOCATED NEAR
EASTERN WYOMING. ALSO ACROSS EASTERN WYOMING AND WESTERN NEBRASKA
AT 00Z THURSDAY WAS A 500MB THERMAL TROUGH. A 700MB BAROCLINIC
ZONE STRETCHED FROM EASTERN NEBRASKA IN TO NORTHEAST COLORADO. A
850MB COLD FRONT EXTENDED FROM SOUTHEAST NEBRASKA INTO NORTHWEST
KANSAS/EASTERN COLORADO. AT THE SURFACE A COLD FRONT APPEARS TO BE
LOCATED ACROSS NORTH CENTRAL AND SOUTHWEST KANSAS WITH MULTIPLE
OUTFLOW BOUNDARIES ALSO PRESENT FROM THE ONGOING CONVECTION.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 133 AM CDT THU JUL 26 2012
CONVECTION EARLIER THIS MORNING APPEARS TO HAVE RELATED WELL WITH AN
AREA OF 850-700MB FRONTOGENESIS OCCURRING AHEAD OF A 500MB TROUGH.
LATEST RAP AND NAM WERE IN DECENT AGREEMENT AND PLACES THIS ARE OF
BETTER FORCING EAST/SOUTHEAST OF DODGE CITY BETWEEN 09Z AND 12Z
THURSDAY. WILL CONTINUE TO MONITOR RADAR TREND BUT AT THIS TIME
THIS AREA OF CONVECTION SHOULD BE EXITING SOUTH CENTRAL KANSAS
AROUND 12Z.
MORNING CLOUD COVER WILL GIVE WAY TO CLEARING SKIES AS THE UPPER
TROUGH MOVES INTO CENTRAL KANSAS. 850MB TEMPERATURES DO INDICATED
A COOLING TREND TODAY AND BY 00Z FRIDAY THE 850MB TEMPERATURES ARE
FORECAST TO RANGE FROM 23-25C IN CENTRAL KANSAS TO THE UPPER 20S TO
NEAR 30C NEAR THE COLORADO BORDER. GIVEN THESE TEMPERATURES ALONG
WITH THE OVERNIGHT RAINFALL AND A EAST/NORTHEASTERLY FLOW IN THE
LOWER LEVELS WILL TREND TOWARDS KEEPING TEMPERATURES CLOSER TO THE
PREVIOUS FORECAST WHICH WERE COOLER THAN THE NAM 2M TEMPERATURES
BUT NOT AS COOL AS THE GFS.
TONIGHT AN UPPER LEVEL RIDGE AXIS WILL BUILD EAST INTO THE
ROCKIES AS SUBTLE UPPER LEVEL DISTURBANCE ROTATES OUT INTO THE
PLAINS. BASED ON MODEL SOUNDINGS MOISTURE AND INSTABILITY WILL
CONTINUE WITH A DRY FORECAST. LOWS BOTTOMING OUT IN THE MID 60S TO
AROUND 70S STILL APPEARS TO BE ON TRACK.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 236 AM CDT THU JUL 26 2012
UPPER LEVEL RIDGING WILL BE THE DOMINANT FEATURE ON FRIDAY. A
NORTHWESTERLY JET STREAK WILL BE OVER THE NORTHERN PLAINS, WITH WEAK
SURFACE HIGH PRESSURE ACROSS THE UPPER MIDWEST. RELATIVE HUMIDITY
FIELDS FROM THE GFS AND ECMWF INDICATE THE PRESENCE OF MID LEVEL
MOISTURE. HOWEVER THE LOW LEVELS ARE LIKELY TO BE MUCH DRIER, AND
TEMPERATURES WILL QUICKLY RISE INTO THE UPPER 90S BY EARLY
AFTERNOON. THE WEAK SURFACE PRESSURE PATTERN FEATURING A NORTHERN
HIGH PLAINS TROUGH WILL CONTRIBUTE TO DEVELOPMENT OF LIGHT SOUTHEAST
SURFACE WINDS FRIDAY.
MOVING FARTHER INTO THE WEEKEND, THE UPPER RIDGE BEGINS TO DRIFT
SLIGHTLY FARTHER SOUTHEAST, AND THE UPPER JET SEGMENTS THAT WERE
PREVIOUSLY STREAKING THROUGH THE NORTHERN PLAINS BECOME SHIFTED
CLOSER TO THE CENTRAL PLAINS. DURING THE LATE WEEKEND INTO EARLY
NEXT WEEK, A CONDITIONALLY UNSTABLE AIRMASS WILL BE IN PLACE, WITH
THE POTENTIAL FOR LATE DAY SURFACE BASED CONVECTION ALONG WEAK
SURFACE CONVERGENCE ZONES. SUBTLE SHORTWAVE ENERGY COULD ALSO COME
INTO PLAY AND ENHANCE LIFT FOR ELEVATED CONVECTION INTO THE LATER
HOURS THROUGH ABOUT TUESDAY EVENING.
ASSOCIATED WITH THE PERSISTENT UPPER RIDGING THROUGH THE CENTRAL AND
SOUTHERN PLAINS, TEMPERATURES WILL REMAIN VERY WARM IN THE UPPER 90S
TO AROUND 100 DEGREES FOR DAILY HIGHS. ADDED TO THIS WILL BE SOME
UNCERTAINTY IN VARIABILITY IF ANY PERIODS OF ENHANCED CLOUDINESS OR
EARLY AFTERNOON THUNDERSTORMS DEVELOP, AUGMENTING LOCAL TEMPERATURES.
OVERNIGHT LOWS SHOULD REMAIN MILD AS WELL, GENERALLY IN THE UPPER
60S, THROUGH THE 70S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 649 AM CDT THU JUL 26 2012
INFRARED SATELLITE IMAGERY AND AND REGIONAL METAR OBSERVATIONS
INDICATES CLEARING BELOW 12KFT ACROSS THE AREA THIS MORNING. THE
CLEARING TREND IS EXPECTED TO CONTINUE THROUGH THE REMAINDER OF THE
MORNING, AS RADAR IMAGERY CONTINUES TO INDICATE AS WEAK MCV EXITING
INTO WESTERN OKLAHOMA. NORTHEAST SURFACE WINDS SHOULD INCREASE WITH
MODERATE GUSTS TO AROUND 20 KNOTS BY LATE MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 95 67 101 71 / 10 10 10 10
GCK 95 66 100 70 / 10 10 10 10
EHA 94 67 98 69 / 0 10 10 10
LBL 96 67 100 70 / 0 10 10 10
HYS 97 66 101 71 / 10 10 10 10
P28 97 70 103 73 / 20 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...RUSSELL
AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1126 AM EDT THU JUL 26 2012
.SYNOPSIS...
EXPECT HOT AND HUMID CONDITIONS THIS AFTERNOON, UNTIL A SQUALL
LINE OF SEVERE THUNDERSTORMS MOVES THROUGH WITH DAMAGING WIND,
HAIL, HEAVY RAIN, AND LOTS OF LIGHTNING. THERE WILL STILL BE
SCATTERED THUNDERSTORMS AROUND UNTIL A COLD FRONT BRINGS LOWER
HUMIDITY SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE MAIN CONCERN THIS AFTERNOON AND EVENING WILL BE THE PASSAGE OF
A SQUALL LINE OF SEVERE THUNDERSTORMS WITH DAMAGING WIND, HAIL,
HEAVY RAIN, AND LOTS OF LIGHTNING. SPC CONTINUES TO PROJECT A
MODERATE RISK OF SEVERE THUNDERSTORMS FOR THE ENTIRE UPPER OHIO
VALLEY, WITH WIDESPREAD DAMAGING THUNDERSTORMS THE MOST PROBABLE
SEVERE THUNDERSTORM HAZARD. HPC HAS JOINED IN WITH A SLIGHT RISK
OF EXCESSIVE RAINFALL. RAIN AMOUNTS OF MORE THAN 1.5 INCHES IN
LESS THAN 3 HOURS CAN CAUSE FLASH FLOODING IN URBAN AREAS AND
WHERE DRAINAGE IS POOR.
CONCUR WITH THESE FORECASTS BASED ON RECENT SREF INSTABILITY AND
VERTICAL SHEAR PROFILES.
RECENT SATELLITE DATA SHOWS THE LEADING EDGE OF THICKER CLOUDS
FROM KMFD TO KCVG. ALSO A BAND OF CUMULUS IS DEVELOPING FROM KHLG
TO KLEX. THE FORMER IS MORE LIKELY WHERE THE SQUALL LINE WILL
FORM, BUT THE LATTER HAS TO BE MONITORED ALSO. RECENT HRRR MODEL
OUTPUT, ALONG WITH 00Z WRF-NMM MODEL OUTPUT, SHOWS THE FOLLOWING
TIMING OF SQUALL LINE ONSET.
FRANKLIN PA TO ZANESVILLE OH/ KFKL-KZZV/: 2-4PM.
DUBOIS-PITTSBURGH PA-WHEELING WV/ KDUJ-KPIT-KHLG/: 3-5PM.
INDIANA-MORGANTOWN WV/ KIDI-KMGW/: 4-6PM.
OAKLAND MD/ K2G4/: 6 PM.
CONTINUE TO EXPECT SCATTERED THUNDERSTORMS IN THE WAKE OF THE
SYSTEM.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
RECENT SREF MODEL OUTPUT SHOWS HUMID AND HENCE UNSTABLE
CONDITIONS REMAINING ACROSS THE UPPER OHIO VALLEY UNTIL THE COLD
FRONT, WITH LOWER DEW POINTS, MOVES SOUTHWARD THROUGH AREA,
SATURDAY NIGHT. THUS HAVE MAINTAINED A CHANCE OF THUNDERSTORMS
INTO SATURDAY EVENING. SUNDAY SHOULD BE DRY.
FORECASTED TEMPERATURES USING BLEND OF RECENT GFS AND NAM MOS AND
SREF MEAN VALUES, WHICH INDICATED TEMPERATURES CONTINUING WARMER
THAN NORMAL, WITH DAYTIME HIGHS BY UP TO 5 DEGREES, AND EARLY
MORNING LOWS BY UP TO 10 DEGREES.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
MEDIUM RANGE MODELS SHOW SURFACE HIGH PRESSURE AND DRY CONDITIONS
FOR MONDAY.
AN UPPER TROUGH IS PROGGED TO REMAIN OVER THE EAST COAST EARLY
NEXT WEEK. MODELS HINT AT A SURFACE LOW MOVING ALONG THE EAST
COAST TUESDAY AND WEDNESDAY. PLAN TO KEEP CHANCE POPS FOR SHOWERS
AND THUNDERSTORMS MONDAY NIGHT THROUGH WEDNESDAY.
FORECAST TEMPERATURES ARE CLOSE TO HPC GUIDANCE AND WILL BE
GENERALLY A FEW DEGREES ABOVE NORMAL THROUGH THE EXTENDED PERIOD.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
THE MAIN FORECAST ISSUE WL BE THE DEVELOPMENT AND COVERAGE OF TSRA AS
OUTFLOW FM A GREAT LAKES MCS...AS WELL AS THE CDFNT MOVE TOWARD
THE REGION. CONFIDENCE IS HIGH THAT MOST PORTS WL EXPERIENCE
THUNDERSTORMS WITH COVERAGE INCREASING FM N TO S AS THE DAY
PROGRESSES. IFR RESTRICTIONS IN HEAVY RAIN CAN BE ANTICIPATED AND
SFC GUSTS IN EXCESS OF 50KT ARE POSSIBLE.
EXPECT NO MORE THAN SCATTERED THUNDERSTORMS THE REST OF TONIGHT.
POST-STORM FOG MAY ALSO CAUSE A SHORT PERIOD OF IFR RESTRICTIONS.
OUTLOOK...FRIDAY THROUGH MONDAY...
SCATTERED THUNDERSTORMS MAY PROVIDE RESTRICTIONS FRIDAY INTO
SATURDAY AS A SECONDARY FRONT PUSHES ACROSS THE TERMINALS. DRY VFR
CONDITIONS ARE EXPECTED UNDER SURFACE HIGH PRESSURE SUNDAY AND
MONDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR OHZ039>041-
048>050-057>059-068-069.
PA...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR PAZ020-021-029-
031-073-075.
WV...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR WVZ001>004-012-
021-022.
&&
$$
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
616 AM CDT THU JUL 26 2012
...UPDATED AVIATION DISCUSSION...
.DISCUSSION...
Short Term (Today through Saturday Night)...
After 34 days without significant precipitation at the WFO, the
sounds of a steady rain and a great lightning show have been nothing
short of a welcomed miracle. Leading gust front now washing out
along the leading edge of the CWA, with elevated post-frontal
convection being maintained ahead of several well defined radar MCV
circulations. Aided by a 25-30 knot low level jet ascending over the
gust front, expect scattered convection to persist for the next
several hours with sufficient CAPE for lightning restricted
generally along and south of a MCI-IRK line.
For today, several forecast challenges related to POPs/temperatures.
Upstream mid level closed low is still over srn Manitoba, positioned
well NW of earlier model placement. This will lead to a much later
upper wave passage across the CWA today. Although muddied by
convection and nocturnal effects, it appears that the effective cold
front is still located across srn Nebraska into central Iowa,
denoted by a modest wind shift and dewpoint gradient. Pre-frontal
dewpoints have approaches seasonal highs in the lower 70s, driven
primarily by precipitation. My concern is that once nocturnal
activity dissipates and convective cloud debris erodes, strong
daytime heating could occur in a very moist and uncapped warm sector
ahead of a rather diffuse surface frontal zone. Per 06Z NAM and
recent HRRR guidance, this theory is well supported, and have
decided to drag POPs back to the northwest. Depending on how quickly
cloud cover erodes, the airmass could support surface based
thunderstorm development as early as 18Z. Increasingly northwesterly
flow aloft (although considerably stronger over the Ohio Valley)
could support some storm organization with an attendant threat for
damaging winds if activity grows upscale before exiting the CWA.
Temperatures will be highly conditional on the erosion of cloud
cover and subsequent convective development, but will opt for
lower-mid 90s as a hedge, with cooler readings certainly not out of
the question. Although on paper this seems like a huge improvement
from the past few weeks, the considerable increase in boundary layer
dewpoints will lead to a very humid conditions and heat indices
locally around 100 degrees.
With the frontal passage tonight, northwest upper flow will become
temporarily established over the area as the mean ridge position
reorganized over the southern High Plains. Seasonably strong
mid-upper flow will yield a rather impressive elevated baroclinic
zone over the region, which will translate to the surface with
daytime mixing. Have adjusted temperatures both Friday and Saturday
to account for this gradient, with hot temperatures persisting over
west central MO/ern KS and notably more tolerable conditions over NE
MO. This gradient becomes even more impressive Saturday and would
not be surprised to see highs in the upper 80s over NE MO vs. lower
100s over and south of Kansas City. Along with the brief intrusion
of cooler air into portions of the area, it is possible that
dewpoints Fri/Sat could be even lower than forecast, with some
guidance suggesting they fall into the lower 50s.
To further complicate matters, there is justifiable concern about
MCS activity on Saturday into Saturday Night. Most 00Z guidance show
a Pacific shortwave emerging from the Rockies Friday evening,
sparking a convective complex over the Black Hills region. The sharp
elevated baroclinic zone/instability axis would suggest this complex
would be well maintained along an ESE track, reaching nrn MO
Saturday afternoon. Meanwhile, the ridge will continue to
strengthen, helping return that frontal zone north as a warm front.
Thus, the question remains whether the edge of the cap is across nrn
MO or back into Iowa by the time this system arrives. Low chance
POPs probably the best way to go for now, although this will
probably end up being an all or nothing event once it draws closer.
Bookbinder
Medium Range (Sunday through Wednesday)...
Sunday - Monday: A upper level ridge of high pressure will extend
from the Southern Plains northwestward into the Eastern Rockies.
This will leave the area under northwesterly flow aloft. A series of
shortwaves are progged to round this ridge and move into the local
area on Sunday and Monday. This will make for a challenging forecast
through this period. The best chances for precipitation will be
mainly across the northern and eastern half of the CWA through
Monday although a complex of thunderstorms could develop on Sunday
and bring the chance for thunderstorms to the southern half of the
CWA as well and as such kept slight chance POPs across the southern
portion of the forecast area on Sunday. These system will also make
forecasting temperatures challenging with the northern CWA being
cooler with the potential for precipitation and excess cloud cover.
Thusly for Sunday and Monday have a gradient of temperatures ranging
from the lower 90s across north central Missouri sloping to the
upper 90s across east central Kansas and west central Missouri.
Tuesday - Wednesday: The upper level ridge will shift slowly
eastward with the local area moving under its influence by Tuesday.
This in turn will keep the local area dry through the period.
Temperatures on the other hand will warm a bit as height rises
through the period will help temperatures warm into the mid 90s to
near 100.
73
&&
.AVIATION...
For the 12Z TAFs, a few light showers remain around the terminals
through around 13Z. Otherwise...expect VFR conditions as mainly bkn
mid level clouds are expected at the terminals this morning through
the early afternoon hours with skies clearing out this evening.
Winds will be light and variable this morning as a cold front reside
across northwest Missouri. As this cold front drops through the
terminals late this morning, winds will pick up out of the northwest
between 5-10kts before becoming light and variable again tonight.
73
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1146 AM EDT THU JUL 26 2012
.SYNOPSIS...
LINGERING SHOWERS WILL REMAIN ACROSS THE AREA INTO EARLY
AFTERNOON...WITH THE POTENTIAL FOR ORGANIZED SEVERE STORMS BY MID
AFTERNOON...ESPECIALLY OVER THE SOUTHERN TIER AND NORTHEAST
PENNSYLVANIA. THE FRONTAL BOUNDARY WILL DRIFT SOUTHWARD ON FRIDAY
INTO SOUTHERN PENNSYLVANIA...BUT THE THREAT OF UNSETTLED WEATHER
WILL PERSIST.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
11 AM UPDATE...ELONGATED SFC LOPRES EXTENDS FM LK HURON THRU SRN
ONTARIO...WITH WMFNT DRAPED ACRS CWA MAINLY ALONG THE I-81
CORRIDOR. EXTENSIVE CLD CVR STILL EXISTS ACRS NRN HALF OF THE CWA
UP NR THE FINGER LKS INTO THE MOHAWK VLY COURTESY OF MCS WHICH
ROLLED THRU THIS MRNG. THINNING CLDS ARE STARTING TO BREAK UP FM
NEPA INTO THE CNTRL SRN TIER AND EAST INTO THE CATSKILLS AREA.
DEVELOPMENT OF TSTMS THIS AFTN WL BE DEPENDENT ON EROSION OF CLDS.
DWPTS HV RISEN INTO THE U60 ACRS WRN PORTION OF CWA WITH LOW 70S
ACRS WRN PA AND ERN OH IN TREMENDOUS SURGE OF MOISTURE.
CONVECTIVELY INDUCED S/WVS ARE EMBEDDED IN THE FLOW AND WL
INTERACT WITH MOISTURE AND INSTABILITY TO HELP SPARK OFF STORMS IN
THE CENTRAL SRN TIER BTWN 18Z-19Z PER LATEST HRRR REFLECTIVITY
IMAGE. 12Z NAM/RUC SNDGS IN BUFKIT HV LOWERED CAPE VALUES TO
AROUND 1000 J/KG...LIKELY DUE TO THE FACT THAT HEATING HAS BEEN
TEMPERED BY CLD CVR THUS FAR. LATEST SPC DAY1 OUTLOOK HAS SHIFTED
MODERATE RISK SOUTH AND ONLY INCLUDES SNIPPETS OF BROOME CNTY AND
DELAWARE CNTY ALONG WITH ALL OF SULLIVAN CNTY. SOME QUESTIONS
STILL RMN AS TO HOW THUNDERSTORMS WL DVLP IN WAKE OF CLD CVR
FURTHER TO THE NORTH. OVERALL...MAIN SVR WX THREAT FOR DAMAGING
WINDS, LARGE HAIL, AND ISOLD TORNADOES HAS SHIFTED MORE INTO THE
SRN TIER AND NEPA. CONVECTIVE MODE LOOKS TO BE IN THE FORM OF A
MORE LINEAR STRUCTURE WITH EMBEDDED BOWS. ANY DISCRETE CELL THAT
CAN DEVELOP AHD OF THE MAIN LINE WL LKLY ROTATE.
THUS HV KEPT POPS THE SAME WITH LKLY POPS PRETTY MUCH AREA WIDE BY
THIS AFTN. UPDATED SVR WX OUTLOOK, GRAPHICAL HWO AND GRIDS TO
REFLECT CURRENT THINKING.
5 AM UPDATE... AN ACTIVE DAYTIME AND EVENING PD EXPECTED.
SHRA/TSRA CONTINUE TO TRANSLATE ESEWD ACRS THE RGN ATTM...ASSOCD
WITH AN INCOMING WARM FRNT...AND ATTENDANT STG WAA FORCING AND
MOISTURE ADVECTION. STORMS ARE ELEVATED IN NATURE EARLY THIS
MRNG OVER CNY/NE PA...WITH THE BEST INSTAB STILL LOCATED WELL BACK
INTO THE WARM SECTOR...ACRS LK ERIE...LWR MI...AND THE OH VLY. DUE
TO THE ELEVATED NATURE OF THE CONVECTION ATTM...WE FEEL THE NEAR-
TERM SVR THREAT IS LOW...WITH LOCALLY +RA...SMALLER HAIL...AND
GUSTY WINDS TO ARND 40 MPH PERCEIVED TO BE THE MAIN THREATS.
HRRR/WRF SIM REFL PROGS SHOW A PSBL LULL IN THE ACTION LATER THIS
MRNG INTO THE EARLY AFTN...AS THE PRESENT ACTIVITY SLIDES FARTHER
TO THE E AND WEAKENS A BIT. IF THIS LULL DOES OCCUR...THOUGH...IT
SHOULD BE SHORT-LIVED. BY/AFTER 18Z...TSRA SHOULD REINVIGORATE...OWING
TO RAPID DESTABILIZATION AND IMPROVED UPR-LVL JET DYNAMICS. THE
EXACT EVOLUTION REMAINS UNCLEAR LATER TDY INTO THE EARLY
EVE...WITH REGARDS TO EXACTLY WHERE TSRA RE-FIRE...AND WHAT MODE
(LINEAR OR MORE DISCRETE CELLS). DEEP-LYRD SHEAR VECTORS ARE
WRLY...WHICH WOULD BE ORIENTED ORTHOGONAL TO ANY N-S BNDRYS (PRE-
FRNTL TROUGHS...OUTFLOW...OR THE ERN EDGE OF THE SFC WARM
FRNT)...AND THIS COULD FAVOR DISCRETE SUPERCELLS IN THESE
LOCATIONS. UPSTREAM ACTIVITY COMING EWD FROM LWR MI/SRN
ONT...WOULD POINT TO THE PSBLTY OF MORE CLDS/PCPN IN THE NRN HALF
OF THE FA (FINGER LKS/SRN TUG/WRN MOHAWK VLY RGNS). THIS WOULD
POTENTIALLY YIELD MORE STABLE CONDS THESE LOCALES. HOWEVER...JUST
TO THE S OVER NY`S SRN TIER AND NRN PA...THE PROSPECTS FOR MORE
SUNSHINE/BETTER HEATING ARE THERE BEHIND CURRENT ACTIVITY...ALG
WITH SOME DIFF HEATING/LEFTOVER OUTFLOW BNDRYS.
THUS...WE FEEL THE BEST SVR THREAT IS IN THE SRN HALF OF THE
CWA...GENERALLY FROM ABT 18Z...INTO THE 00-03Z TIME RANGES...AND
THIS MATCHES SPC`S OUTLOOK (MDT RISK) PRETTY WELL. INSTAB/SHEAR
COMBO (ML CAPE OF 2000-4000...0-6 KM BULK SHEAR ARND 50 KT...AND
0-1 KM HELICITY OF 100-300) ALL POINT TWDS THE LIKELIHOOD OF A
WELL DEVELOPED SQUALL LN...OR SUPERCELLS (PERHAPS EMBEDDED
TORNADIC ONES).
OBVIOUSLY...WE`LL MONITOR DEVELOPMENTS CLOSELY THROUGHOUT THE DAY
AND INTO THE EVE HRS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
530 AM UPDATE... WILL MAKE THIS SHORT...DUE TO NEAR-TERM WX
CONCERNS.
LTR TNT AND FRI...NWP CONSENSUS BRINGS A SFC COLD FRNT SWD THROUGH
THE CWA...AND DOWN TWDS THE MASON-DIXON LN. EVEN ONCE THE FRNT
PUSHES TO OUR S...UNSETTLED CONDS SHOULD PERSIST...WITH UPPER-LVL
WAVES STILL COMING ACRS FM W TO E. WE`LL USE CHC/SCTD POPS RIGHT
THROUGH SAT. THE BEST PROSPECTS FOR PCPN MAY COME FRI NGT AND
EARLY SAT...WITH THE MOST AMPLIFIED TROUGH APPROACHING IN THIS
TIME FRAME.
BY SAT NGT...AS THE BEST FORCING EXITS THE E COAST...DEEPER MOIST
AND MORE ORGANIZED PCPN SHOULD SLIDE FARTHER S AND E...WITH POPS
LWRG OVER TIME.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
MODELS CONTINUE TO FORECAST A LONG WAVE MEAN TROF OVER THE
NORTHEASTERN CONUS DURING THE EXTENDED PERIOD. AS A RESULT, AN
UNSETTLED PATTERN IS EXPECTED TO DEVELOP ACROSS UPSTATE NY AND
NORTHEASTERN PA. THIS WILL BRING WELCOME PRECIPITATION TO MUCH OF
NY/PA.
CANNOT RULE OUT A SHOWER OR THUNDERSTORM DURING ANY 24 HOUR
PERIOD...HOWEVER IT APPEARS THE BEST CHANCE FOR PRECIPITATION WILL
COME EARLY NEXT WEEK WHEN A WEAK SURFACE CYCLONE IS FORECAST
DEVELOP UNDER THE UL TROF AXIS OVER MICHIGAN AND CENTRAL OHIO.
THIS WILL CAUSE AN INCREASED FLOW OF SFC MOISTURE INTO NY/PA, WITH
A WARM FRONT POTENTIALLY SETTING UP ACROSS OUR FORECAST AREA.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
700 AM UPDATE...
A LINE OF THUNDERSTORMS HAS YET TO CLEAR KAVP. HERE...BRIEF MVFR
OR IFR VSBYS POSSIBLE THROUGH 13Z IN HEAVY RAIN. OTHERWISE SHOWERS
THROUGH 15Z MAY PRODUCE VERY BRIEF MVFR VSBYS BUT FOR THE MOST
PART AN OVC MID DECK AROUND 5KFT WITH VSBYS ABOVE 6SM EXPECTED.
AFTER SEEING A BREAK IN THE RAIN LATE THIS MORNING...A COLD FRONT
WILL APPROACH THE AREA WITH THUNDERSTORMS RE-DEVELOPING AFTER 18Z.
THESE STORMS COULD BECOME SEVERE WITH HIGH WINDS AND LARGE HAIL
POSSIBLE. BEST THREAT FOR THUNDERSTORMS WILL BE AFTER 18Z...WITH
THE HIGHEST SEVERE THREAT BETWEEN 19Z AND 23Z NORTHERN AND WESTERN
TERMINALS (KITH/KELM/KSYR/KRME)...20Z TO 24Z KBGM...AND 22Z TO 02Z
KAVP. GIVEN AN ENHANCED THREAT FOR SEVERE WEATHER...INCLUDED MVFR
VSBYS AND CIGS ALONG WITH GUSTY WINDS IN A TEMPO GROUP FOLLOWING
THE TIMING SHOWN ABOVE. BEYOND THE TEMPO PERIOD...SHOWERS AND EVEN
SOME THUNDER MAY LINGER INTO EARLY TONIGHT BUT TOO FAR OUT AND
CONFIDENCE NOT HIGH ENOUGH ON EXACT TIMING TO INCLUDE
RESTRICTIONS....THUS ONLY INCLUDED -SHRA AT THE MOMENT.
LIGHT AND VARIABLE WINDS EARLY THIS MORNING BECOME SOUTHWEST TODAY
AT AROUND 10 KTS WITH GUSTS TO 25 KTS. WINDS DIMINISH EARLY
TONIGHT AND VEER TOWARD THE WEST AND EVENTUALLY NORTHWEST.
OUTLOOK...
THUR TO FRI NGT...RESTRICTIONS PSBL IN SHRA/TSRA.
SAT/MON...MAINLY VFR UNDER BUILDING HIPRES.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MLJ/PVN
NEAR TERM...MLJ/PVN
SHORT TERM...MLJ
LONG TERM...DJP
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1131 AM EDT THU JUL 26 2012
.SYNOPSIS...
HOT AND HUMID CONDITIONS WILL GIVE WAY TO STRONG TO SEVERE
THUNDERSTORMS THIS AFTERNOON AND EVENING AS A COLD FRONT MOVES
SOUTHEAST TOWARD THE OHIO VALLEY. THE FRONT WILL PUSH INTO THE
AREA TONIGHT AND A LOW PRESSURE SYSTEM WILL CROSS OUR AREA ON
FRIDAY...BRINGING ADDITIONAL SHOWERS AND THUNDERSTORMS TO THE
REGION. HIGH PRESSURE WILL THEN BRING MORE SEASONABLE TEMPERATURES
AND DRIER CONDITIONS FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THERE IS MUCH TO TALK ABOUT ON WHAT SHOULD BE AN ACTIVE SEVERE
EVENT THIS AFTERNOON AND EVENING ACRS OUR REGION.
SYNOPTICALLY SPEAKING...THE GREAT LAKES AND OHIO VALLEY WILL
REMAIN UNDER A SOUTHWEST TO WEST FLOW ALOFT TODAY INTO TONIGHT. A
COLD FRONT IS FORECAST TO DROP SOUTHEAST INTO THE REGION LATE IN
THE DAY AND MAY HANG UP ACRS THE NRN AREAS OVERNIGHT. LOOKING AT
SATELLITE IMAGERY...IT SHOULD BE NOTED THAT THERE ARE SEVERAL
EMBEDDED DISTURBANCES IN THE SOUTHWEST TO WEST FLOW ALOFT
EXTENDING FROM MISSOURI NORTHEAST INTO THE WESTERN GREAT LAKES.
TWO FEATURES FROM ERN MISSOURI INTO WESTERN ILLINOIS MAY BE THE
IMPETUS TO GET A QLCS GOING ACRS CENTRAL/SOUTH CENTRAL INDIANA
EARLY THIS AFTN. SFC OBSERVATIONS ALSO INDICATE THAT THERE IS A
PREFRONTAL TROF IN THIS REGION AS WELL. IF THIS GETS GOING AS THE
LATEST HRRR INDICATES...IT SHOULD INTENSIFY AS IT MOVES
EAST/SOUTHEAST ACRS OUR REGION DURING THE AFTERNOON AND EVENING
HOURS AS IT FEEDS INTO A VERY UNSTABLE AIRMASS OF 2500-3500 J/KG
OF MLCAPE. IT ALSO WILL HAVE THE ORGANIZATION AND MOMENTUM TO MOVE
QUICKLY AS BULK SHEAR BETWEEN 0=6 KM ARE AROUND 40 KNOTS. GIVEN
THAT FLOW WILL BE MAINLY UNIDIRECTIONAL...FEEL TORNADO THREAT WILL
BE MINIMAL WHILE DAMAGING WINDS AND HAIL SHOULD BE THE MAIN
THREATS. IN FACT...IT IS THE DAMAGING WIND POTENTIAL THAT WILL
LIKELY BE THE HIGHEST IMPACT DUE TO 50 KNOT MID LEVEL JET MOVING
ACRS THE REGION...STEEP LOW LEVEL LAPSE RATES...DELTA THREAT E
VALUES OF 25 KELVIN AND DCAPES OF 1000-1500 J/KG. ALTHOUGH TREE
DAMAGE AND POWER OUTAGES MAY OCCUR...ATTM...WE EXPECT THIS FEATURE
TO BEHAVE MORE LIKE A QLCS/BOW ECHO FEATURE AND NOT MIMIC THE JUNE
29 DERECHO THAT CAUSED EXTENSIVE/WIDESPREAD DAMAGE OVER MOST OF
THE ENTIRE REGION. THAT SAID...THERE WILL BE WIND DAMAGE AND OF
COURSE THERE COULD BE POCKETS OF ENHANCED WIND DAMAGE WITH ANY
OUTFLOW/GUST FRONT OR MICROBURST. THUS...THE SPC HAS KEPT MOST OF
OUR AREA IN A MODERATE RISK FOR SEVERE THUNDERSTORMS. PWATS WILL BE
HIGH...IN EXCESS OF 2 INCHES...WITH THE THUNDERSTORM ACTIVITY SO
LOCALLY HEAVY RAIN AND LOCALIZED FLOODING WILL BE POSSIBLE BUT
SHOULD BE LIMITED GIVEN THE SPEED AT WHICH STORMS WILL BE MOVING.
A HOT AND HUMID AIRMASS WILL BE IN PLACE FOR THESE THUNDERSTORMS
TO FEED ON. GIVEN THE AMOUNT OF SUNSHINE OCCURRING OVER THE ERN/SRN
AREAS THIS MORNING...AND THE FACT THAT KILN SOUNDING AND MODEL
SOUNDINGS INDICATE THAT 850 MB TEMPS WILL BE IN THE 23-24 C
RANGE...BELIEVE A GOOD CHUNK OF THIS REGION WILL SEE TEMPERATURES
PEAK INTO THE MID AND UPPER 90S WITH DEWPOINTS IN THE LOWER 70S.
THIS WILL PUSH HEAT INDICES INTO THE 105 TO 108 DEGREE RANGE. AS
SUCH...HAVE UPGRADED THIS REGION TO AN EXCESSIVE HEAT WARNING PER
LOCAL CRITERIA OF A HEAT INDEX OF 105. THE REMAINDER OF THE
REGION...EXCEPT MONTGOMERY COUNTY...REMAINS UNDER A HEAT ADVISORY
FOR HEAT INDICES RANGING FROM 100 TO 104. IT MUST BE NOTED THAT
SHOWERS AND STORMS WILL LIKELY COOL THINGS OFF SIGNIFICANTLY AND
THE HEAT ADVISORY/EXCESSIVE HEAT WARNING WILL LIKELY COME DOWN
BEFORE THE 8 PM EDT DEADLINE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
CONVECTION WILL SHIFT SOUTHEAST LATE THIS EVENING AND WITH THE
LOSS OF DAYTIME HEATING...WILL GRADUALLY LOSE IT/S INTENSITY.
HOWEVER...STORMS WILL STILL BE INTENSE ENOUGH TO PRODUCE SEVERE
WEATHER AT LEAST THROUGH THE FIRST PART OF THE OVERNIGHT PERIOD.
HAVE THEREFORE KEPT THE MENTION OF SEVERE STORMS IN THE GRIDS
THROUGH 03Z. BY THAT TIME...MOST ACTIVITY WILL HAVE SHIFTED TO OUR
SOUTHEASTERN ZONES. THERE...SOME ONGOING CONVECTIVE ACTIVITY COULD
POSE ADDITIONAL FLOOD ISSUES ALONG AND SOUTH OF THE OHIO RIVER
SHOULD THUNDERSTORMS BEGIN TO TRAIN OVER THE SAME LOCATIONS LATE
TONIGHT.
ON FRIDAY THERE ARE STILL SOME DIFFERENCES ON HOW THE MODELS HANDLE
THE SHORTWAVE PIVOTING ACROSS THE GREAT LAKES. THE SREF AND NAM
DEVELOP A WEAK CLOSED SURFACE LOW AHEAD OF THE TROUGH AND DIVE IT
SOUTHWARD TOWARD OUR AREA. THIS WOULD PRODUCE A ROUND OF AFTERNOON
CONVECTION FOR THE EASTERN TWO THIRDS OF THE FORECAST AREA. THE
ARW AND NMM BOTH AGREE WITH THIS SOLUTION. HAVE FORECAST 50/50 POPS
FOR MUCH OF THE AREA FOR FRIDAY AFTERNOON TO REFLECT THIS. DID NOT
GO LIKELY ON POPS SINCE THE ECMWF STILL DOES NOT AGREE WITH THIS
SOLUTION.
REGARDLESS OF WHICH MODEL YOU CHOOSE FROM...COLD ADVECTION FINALLY
STABILIZES US FRIDAY NIGHT AS HIGH PRESSURE BEGINS TO BUILD ACROSS
THE OHIO VALLEY. A FEW RESIDUAL SHOWERS AND THUNDERSTORMS COULD
LINGER INTO SATURDAY ACROSS THE EAST AS THE SFC LOW DEPARTS.
SATURDAY THROUGH SATURDAY NIGHT WILL MARK A RETURN TO MORE
SEASONABLE TEMPERATURES AS THE SFC HIGH PRESSURE SETTLES ACROSS
THE REGION.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
SUNDAY IS PROBABLY THE DAY WITH HIGHEST FORECAST CONFIDENCE AS
SFC HIGH PRESSURE BUILDS OVER THE CWA. TEMPERATURES WILL BE
SEASONABLE WITH FAIRLY LOW HUMIDITY.
THE GFS/NCEP MODELS TAKES A MORE AMPLIFIED TURN BEGINNING
MONDAY...WITH 500 MB HEIGHTS AT ILN RESIDING ON THE LOW END OF NAEFS
SPREAD BY MID WEEK. THIS AFFECTS PCPN FORECASTS MORE THAN
TEMPERATURES HOWEVER OVER THE LOCAL AREA (AS 00Z AND 12Z ECMWF HOLD
A STRONGER SFC RIDGE IN PLACE). TOOK AN ENSEMBLE APPROACH WITH THE
FORECAST...WHICH DID NOT SIGNIFICANTLY CHANGE THE GOING FORECAST.
TUESDAY WILL HAVE THE HIGHEST PCPN CHANCES...SUPPORTED BY
ENSEMBLES...AS WELL AS A SFC BDY/UPPER WAVE THAT MAY SAG DOWN INTO
THE AREA. CANNOT TOTALLY RULE OUT PCPN MONDAY/WEDNESDAY BUT LIMITED
TO 20 POPS. TEMPERATURES WILL RISE SOME AS LOW LEVEL FLOW BECOME
MORE SOUTHERLY...BUT AT THIS TIME LOOK TO REMAIN WITHIN 5 DEGREES OF
NORMAL. HUMIDITY WILL ALSO INCREASE SLIGHTLY...HOLDING UP OVERNIGHT
LOWS.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
THUNDERSTORMS ALONG AND AHEAD OF THE COLD FRONT ARE CONTINUING TO
WORK THEIR WAY SLOWLY EAST THIS MORNING ACROSS ILLINOIS INTO
NORTHWEST INDIANA. AN OUTFLOW BOUNDARY FROM THESE STORMS IS NOW
EVIDENT ON REGIONAL RADARS STRETCHING FROM NORTHEAST INDIANA DOWN
INTO WEST CENTRAL INDIANA. QUESTIONS REMAIN AS TO WHAT WILL HAPPEN
WITH THIS BOUNDARY AS IT PUSHES EAST INTO OUR AREA THROUGH MID TO
LATE MORNING. THE AIRMASS ACROSS OUR AREA REMAINS UNSTABLE AT
LEAST ALOFT AND WITH SURFACE TEMPS STILL IN THE LOW 80S...NOT SURE
THE DEGREE OF LOW LEVEL INHIBITION PRESENT. SEVERAL OF THE LATEST
HI RES MODELS ARE TRYING TO INDICATE SOME SPOTTY SHOWER
DEVELOPMENT ASSOCIATED WITH THIS BOUNDARY OVER THE NEXT SEVERAL
HOURS. HOWEVER...THIS CHANCE APPEARS FAIRLY LOW AT THIS POINT SO
WILL MAINTAIN A DRY FORECAST THIS MORNING. WE SHOULD DESTABILIZE
FURTHER THROUGH THIS AFTERNOON AND AS BETTER FORCING ARRIVES AHEAD
OF THE APPROACHING COLD FRONT...EXPECT SHOWERS AND THUNDERSTORMS
TO DEVELOP THROUGH MID AFTERNOON. SHOWER ACTIVITY SHOULD MOVE OFF
TO THE SOUTHEAST THROUGH LATE AFTERNOON BUT WILL LIKELY SEE A
SECONDARY AREA OF CONVECTION DEVELOP THROUGH EARLY EVENING AS MID
LEVEL TROUGH AXIS APPROACHES. AHEAD OF THE FRONT...EXPECT SOME
GUSTY SOUTHWEST WINDS TO DEVELOP LATER THIS MORNING INTO THIS
AFTERNOON. IN ADDITION...STRONGER WIND GUSTS WILL BE POSSIBLE WITH
CONVECTIVE STORMS. TSTM ACTIVITY SHOULD TAPER OFF LATER THIS
EVENING AND IF WE ARE ABLE TO SCATTER OUT....WE COULD SEE SOME
AREAS OF BR DEVELOP LATER TONIGHT.
OUTLOOK...THUNDERSTORMS ARE POSSIBLE THROUGH FRIDAY NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR OHZ026-034-035-
042>046-051>054-060-062-070-071.
EXCESSIVE HEAT WARNING UNTIL 8 PM EDT THIS EVENING FOR OHZ055-
056-061-063>065-072>074-077>082-088.
KY...EXCESSIVE HEAT WARNING UNTIL 8 PM EDT THIS EVENING FOR
KYZ089>100.
IN...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR INZ050-058-059-
066-073-074.
EXCESSIVE HEAT WARNING UNTIL 8 PM EDT THIS EVENING FOR INZ075-
080.
&&
$$
SYNOPSIS...HICKMAN/LATTO
NEAR TERM...HICKMAN/LATTO
SHORT TERM...HICKMAN/LATTO
LONG TERM...SNYDER
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
606 AM EDT THU JUL 26 2012
.SYNOPSIS...
HOT AND HUMID CONDITIONS WILL GIVE WAY TO STRONG TO SEVERE
THUNDERSTORMS TODAY AS A COLD FRONT MOVES SOUTHWEST TOWARD THE
OHIO VALLEY. THE FRONT WILL PUSH THROUGH THE AREA TONIGHT AND A
LOW PRESSURE SYSTEM WILL CROSS OUR AREA ON FRIDAY...BRINGING
ADDITIONAL SHOWERS AND THUNDERSTORMS TO THE REGION. HIGH PRESSURE
WILL THEN BRING MORE SEASONABLE TEMPERATURES AND DRIER CONDITIONS
FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
STEADY WARM ADVECTION UNDER SOUTHWEST FLOW WILL CONTINUE THROUGH
SUNRISE. OUTFLOW FROM CONVECTION TO OUR NORTHWEST IS TRIGGERING
SHOWERS AND THUNDERSTORMS ACROSS PARTS OF ILLINOIS AND INDIANA.
SOME OF THESE STORMS WILL HOLD TOGETHER AND MAKE IT TO OUR WESTERN
ZONES JUST AFTER SUNRISE THIS MORNING. AS THIS ACTIVITY OUTRUNS
THE FRONTAL FORCING...AND WE ENTER THE DIURNAL MINIMUM FOR
CONVECTION...ANY REMAINING SHOWERS/THUNDERSTORMS WILL DIMINISH BY
MID MORNING. HAVE THEREFORE FORECAST A LULL IN ANY POPS DURING
THE MID MORNING UNTIL EARLY AFTERNOON. THIS FORECAST TO START OFF
THE DAY BEST RESEMBLES THE HRRR AND SREF. HAVE AVOIDED USING THE 00Z
ARW AND SPC WRF FOR THIS PACKAGE...AS THEY APPEAR TO BRING AN
INITIATION OF TOO MUCH CONVECTION TOO FAR EAST...TOO EARLY IN THE
DAY. THIS IS LIKELY DUE TO THE HANDLING OF THE AFOREMENTIONED
OUTFLOW BOUNDARY INTERACTING WITH OUR UNSTABLE AIRMASS...AND NOT
THE DEVELOPMENT OF THE MORE INTENSE...SYNOPTICALLY FORCED
CONVECTION THAT WILL OCCUR LATE THIS AFTERNOON.
WITH ONGOING WARM ADVECTION AND INCREASING SOUTHERLY FLOW TO START
OFF THE DAY...THE BOUNDARY LAYER WILL BE WELL MIXED. TEMPERATURES
OF 20 TO 21 C AT 850 HPA...UNDER PARTLY CLOUDY SKIES...WILL BRING
SURFACE TEMPERATURES QUICKLY INTO THE LOW 90S BY THE EARLY
AFTERNOON. THESE WARM TEMPERATURES WILL COMBINE WITH DEWPOINTS IN
THE LOW 70S TO PRODUCE HEAT INDICES GREATER THAN 100 DEGREES BY
THE EARLY AFTERNOON. HAVE THEREFORE CONTINUED THE HEAT HEADLINES
FOR TODAY.
A SURFACE LOW MOVING EASTWARD ACROSS THE GREAT LAKES WILL DRAG A
COLD FRONT SOUTHWESTWARD TOWARD THE OHIO VALLEY TODAY. IN THE LULL
BEHIND ANY MORNING PRECIPITATION...OUR ATMOSPHERE WILL QUICKLY
DESTABILIZE. THE COMBINATION OF PRE-FRONTAL CONVERGENCE AND A VERY
UNSTABLE AIRMASS WILL TRIGGER THE DEVELOPMENT OF NUMEROUS
THUNDERSTORMS.
THESE INTENSE STORMS WILL BE IN AN ENVIRONMENT OF INCREASING
0 TO 3 KM SHEAR AS THE DAY PROGRESSES...STARTING OFF THE AFTERNOON
AROUND 25 KTS AND ENDING THE DAY AROUND 35 KTS. THE MEAN FLOW FROM
0 TO 3 KM WESTERLIES WILL ALSO INCREASE TO OVER 30 KT THIS
AFTERNOON. THIS WILL LIKELY PRODUCE STORMS THAT WILL ORGANIZE INTO
A QUASI-LINEAR SYSTEM BY LATE THIS AFTERNOON...SURGING EASTWARD
AHEAD OF THE PRE-FRONTAL CONVERGENCE ZONE. AS SHEAR
INCREASES...SOME SUPERCELL CHARACTERISTICS WILL BECOME POSSIBLE
WITH ADDITIONAL LATER THUNDERSTORM DEVELOPMENT BY EARLY THIS
EVENING. THIS SECOND ROUND WILL BE ASSOCIATED WITH AN EMBEDDED
SHORTWAVE. THIS MEANS THAT THERE MAY BE A ONE TWO PUNCH WITH
CONVECTION FOR SOME LOCATIONS IN OUR FORECAST AREA BETWEEN THIS
AFTERNOON AND EVENING TIME FRAME. A SIDE NOTE...THE FIRST ROUND
AND SECOND ROUND MAY NOT HAVE TOO MUCH OF A TIME LAPSE BETWEEN
THEM.
THE MAIN THREAT FROM THE OVERALL CONVECTION TODAY WILL BE
WIDESPREAD DAMAGING WINDS WITH POWER OUTAGES POSSIBLE. HOWEVER
LARGE HAIL COULD OCCUR WITH ANY OF THE STRONGER UPDRAFTS.
ALSO...CANNOT RULE OUT AN ISOLATED TORNADO IF THE RIGHT CONDITIONS
COME TOGETHER LATE TODAY...LL SHEAR...BOUNDARY INTERACTION...ETC.
IF PARTICULAR LOCATIONS DO RECEIVE A ONE TWO PUNCH OF
CONVECTION...OR TRAINING OF STORMS OCCURS...THEN LOCALIZED
FLOODING CAN ALSO BECOME AN ISSUE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
CONVECTION WILL SHIFT SOUTHEAST LATE THIS EVENING AND WITH THE
LOSS OF DAYTIME HEATING...WILL GRADUALLY LOSE IT/S INTENSITY.
HOWEVER...STORMS WILL STILL BE INTENSE ENOUGH TO PRODUCE SEVERE
WEATHER AT LEAST THROUGH THE FIRST PART OF THE OVERNIGHT PERIOD.
HAVE THEREFORE KEPT THE MENTION OF SEVERE STORMS IN THE GRIDS
THROUGH 03Z. BY THAT TIME...MOST ACTIVITY WILL HAVE SHIFTED TO OUR
SOUTHEASTERN ZONES. THERE...SOME ONGOING CONVECTIVE ACTIVITY COULD
POSE ADDITIONAL FLOOD ISSUES...SHOULD THUNDERSTORMS BEGIN TO TRAIN
OVER THE SAME LOCATIONS LATE TONIGHT.
ON FRIDAY THERE ARE STILL SOME DIFFERENCES ON HOW THE MODELS HANDLE
THE SHORTWAVE PIVOTING ACROSS THE GREAT LAKES. THE SREF AND NAM
DEVELOP A WEAK CLOSED SURFACE LOW AHEAD OF THE TROUGH AND DIVE IT
SOUTHWARD TOWARD OUR AREA. THIS WOULD PRODUCE A ROUND OF AFTERNOON
CONVECTION FOR THE EASTERN TWO THIRDS OF THE FORECAST AREA. THE
ARW AND NMM BOTH AGREE WITH THIS SOLUTION. HAVE FORECAST 50/50 POPS
FOR MUCH OF THE AREA FOR FRIDAY AFTERNOON TO REFLECT THIS. DID NOT
GO LIKELY ON POPS SINCE THE ECMWF STILL DOES NOT AGREE WITH THIS
SOLUTION.
REGARDLESS OF WHICH MODEL YOU CHOOSE FROM...COLD ADVECTION FINALLY
STABILIZES US FRIDAY NIGHT AS HIGH PRESSURE BEGINS TO BUILD ACROSS
THE OHIO VALLEY. A FEW RESIDUAL SHOWERS AND THUNDERSTORMS COULD
LINGER INTO SATURDAY ACROSS THE EAST AS THE SFC LOW DEPARTS.
SATURDAY THROUGH SATURDAY NIGHT WILL MARK A RETURN TO MORE
SEASONABLE TEMPERATURES AS THE SFC HIGH PRESSURE SETTLES ACROSS
THE REGION.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
SUNDAY IS PROBABLY THE DAY WITH HIGHEST FORECAST CONFIDENCE AS
SFC HIGH PRESSURE BUILDS OVER THE CWA. TEMPERATURES WILL BE
SEASONABLE WITH FAIRLY LOW HUMIDITY.
THE GFS/NCEP MODELS TAKES A MORE AMPLIFIED TURN BEGINNING
MONDAY...WITH 500 MB HEIGHTS AT ILN RESIDING ON THE LOW END OF NAEFS
SPREAD BY MID WEEK. THIS AFFECTS PCPN FORECASTS MORE THAN
TEMPERATURES HOWEVER OVER THE LOCAL AREA (AS 00Z AND 12Z ECMWF HOLD
A STRONGER SFC RIDGE IN PLACE). TOOK AN ENSEMBLE APPROACH WITH THE
FORECAST...WHICH DID NOT SIGNIFICANTLY CHANGE THE GOING FORECAST.
TUESDAY WILL HAVE THE HIGHEST PCPN CHANCES...SUPPORTED BY
ENSEMBLES...AS WELL AS A SFC BDY/UPPER WAVE THAT MAY SAG DOWN INTO
THE AREA. CANNOT TOTALLY RULE OUT PCPN MONDAY/WEDNESDAY BUT LIMITED
TO 20 POPS. TEMPERATURES WILL RISE SOME AS LOW LEVEL FLOW BECOME
MORE SOUTHERLY...BUT AT THIS TIME LOOK TO REMAIN WITHIN 5 DEGREES OF
NORMAL. HUMIDITY WILL ALSO INCREASE SLIGHTLY...HOLDING UP OVERNIGHT
LOWS.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
THUNDERSTORMS ALONG AND AHEAD OF THE COLD FRONT ARE CONTINUING TO
WORK THEIR WAY SLOWLY EAST THIS MORNING ACROSS ILLINOIS INTO
NORTHWEST INDIANA. AN OUTFLOW BOUNDARY FROM THESE STORMS IS NOW
EVIDENT ON REGIONAL RADARS STRETCHING FROM NORTHEAST INDIANA DOWN
INTO WEST CENTRAL INDIANA. QUESTIONS REMAIN AS TO WHAT WILL HAPPEN
WITH THIS BOUNDARY AS IT PUSHES EAST INTO OUR AREA THROUGH MID TO
LATE MORNING. THE AIRMASS ACROSS OUR AREA REMAINS UNSTABLE AT
LEAST ALOFT AND WITH SURFACE TEMPS STILL IN THE LOW 80S...NOT SURE
THE DEGREE OF LOW LEVEL INHIBITION PRESENT. SEVERAL OF THE LATEST
HI RES MODELS ARE TRYING TO INDICATE SOME SPOTTY SHOWER
DEVELOPMENT ASSOCIATED WITH THIS BOUNDARY OVER THE NEXT SEVERAL
HOURS. HOWEVER...THIS CHANCE APPEARS FAIRLY LOW AT THIS POINT SO
WILL MAINTAIN A DRY FORECAST THIS MORNING. WE SHOULD DESTABILIZE
FURTHER THROUGH THIS AFTERNOON AND AS BETTER FORCING ARRIVES AHEAD
OF THE APPROACHING COLD FRONT...EXPECT SHOWERS AND THUNDERSTORMS
TO DEVELOP THROUGH MID AFTERNOON. SHOWER ACTIVITY SHOULD MOVE OFF
TO THE SOUTHEAST THROUGH LATE AFTERNOON BUT WILL LIKELY SEE A
SECONDARY AREA OF CONVECTION DEVELOP THROUGH EARLY EVENING AS MID
LEVEL TROUGH AXIS APPROACHES. AHEAD OF THE FRONT...EXPECT SOME
GUSTY SOUTHWEST WINDS TO DEVELOP LATER THIS MORNING INTO THIS
AFTERNOON. IN ADDITION...STRONGER WIND GUSTS WILL BE POSSIBLE WITH
CONVECTIVE STORMS. TSTM ACTIVITY SHOULD TAPER OFF LATER THIS
EVENING AND IF WE ARE ABLE TO SCATTER OUT....WE COULD SEE SOME
AREAS OF BR DEVELOP LATER TONIGHT.
OUTLOOK...THUNDERSTORMS ARE POSSIBLE THROUGH FRIDAY NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
OHZ026-034-035-042>046-051>056-060-062>065-070>074-
078>082-088.
EXCESSIVE HEAT WARNING UNTIL 8 PM EDT THIS EVENING FOR OHZ061-
077.
KY...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
KYZ089>100.
IN...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
INZ050-058-059-066-073>075-080.
&&
$$
SYNOPSIS...LATTO
NEAR TERM...LATTO
SHORT TERM...LATTO
LONG TERM...SNYDER
AVIATION...JGL
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS MIAMI FL
324 PM EDT THU JUL 26 2012
.UPDATE...A SHOWER HAS RECENTLY DEVELOPED NEAR THE IMMOKALEE
AREA...AND THE CU FIELD IS MORE ESTABLISHED OVER SOUTH FL THIS
AFTERNOON COMPARED TO YESTERDAY. HRRR SHOWS ISOLATED ACTIVITY
DEVELOPING, BECOMING FOCUSED ACROSS THE LAKE OKEECHOBEE REGION.
THERE STILL WILL BE A STRUGGLE TO GET MUCH CONVECTION GOING THIS
AFTERNOON, DUE TO A CAP, BUT STRONG HEATING COULD ALLOW FOR
ISOLATED TSTORMS TO DEVELOP. SO ADDED THIS POSSIBILITY TO THE
FORECAST. /GREGORIA
&&
.PREV DISCUSSION... /ISSUED 237 PM EDT THU JUL 26 2012/
DISCUSSION...
THE LATEST GUIDANCE CONTINUES TO INDICATE THE DRIER AND STABLE
AIR MASS CURRENTLY ACROSS THE REGION SHOULD PREVAIL INTO AND
LIKELY THROUGH THE WEEKEND. AN AREA OF HIGH SURFACE PRESSURE JUST
TO THE EAST OF THE BAHAMAS IS FORECAST TO PERSIST INTO AND LIKELY THROUGH
THE WEEKEND. THIS WILL MAINTAIN A WEAKER PRESSURE GRADIENT ACROSS
THE REGION WITH WINDS 10 KNOTS OR LESS ACROSS THE REGIONAL WATERS
WITH THE EAST AND WEST COAST SEA BREEZES EXPECTED EACH DAY FRIDAY
AND THROUGH THE WEEKEND. LOW LEVEL AVAILABLE MOISTURE IS FORECAST
TO BE LIMITED THROUGH THE WEEKEND WITH MINIMAL CHANCE OF
CONVECTION AND PRECIP ACROSS THE REGION AND NONE CURRENTLY IN THE
FORECAST FOR THE NEXT SEVERAL DAYS.
THE LATEST GUIDANCE FOR DUST CONCENTRATIONS INDICATE SAHARAN DUST
CONTINUING ACROSS THE AREA AT LEAST THROUGH FRIDAY WITH HAZY
SKIES EXPECTED AND WILL LIKELY EXTEND INTO THE WEEKEND AS WELL.
MARINE...
A LIGHT SOUTHERLY TO SOUTHEASTERLY FLOW NEAR 10 KNOTS OR LESS
WILL PREVAIL ACROSS REGIONAL WATERS TONIGHT AND IS EXPECTED TO
CONTINUE THROUGH THE WEEKEND WITH MAINLY TRANQUIL SEAS FORECAST
FOR THE LOCAL GULF AND ATLANTIC WATERS TONIGHT THROUGH THE
WEEKEND.
FIRE WEATHER...
NO FIRE WEATHER CONCERNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 79 92 79 89 / - 10 - 10
FORT LAUDERDALE 81 91 81 90 / - 10 - 10
MIAMI 80 92 80 89 / - 10 - 10
NAPLES 77 89 76 91 / - 10 - 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
333 PM CDT THU JUL 26 2012
.SYNOPSIS...
12Z UA ANALYSIS HAS AN 850MB COLD FRONT FROM NORTHERN WISCONSIN
SOUTHWEST INTO THE OKLAHOMA PANHANDLE. SEVERAL TROFS WERE ACROSS
THE NORTHERN PLAINS BEHIND THE 850MB COLD FRONT. RADAR/SATELLITE
TRENDS THROUGH MID AFTERNOON SHOW DIURNAL CONVECTION HAS DEVELOPED
FROM SOUTHERN WISCONSIN INTO SOUTHEAST IOWA.
18Z SFC ANALYSIS HAS A FRONT/BOUNDARY FROM KVOK BACK TO KRSL. THIS
BOUNDARY MAY BE A VERY DIFFUSE COLD FRONT AS DEW POINTS QUICKLY
DROP INTO THE UPPER 50S AND LOWER 60S BEHIND THE BOUNDARY. AHEAD
OF THE FRONT/BOUNDARY DEW POINTS WERE IN THE LOW 70S.
&&
.SHORT TERM...TONIGHT AND FRIDAY
AN AREA OF DIFFERENTIAL HEATING ALONG THE FRONT/BOUNDARY HAS
ALLOWED CONVECTIVE TEMPERATURE TO BE ACHIEVED.
RAP TRENDS INDICATE THE CURRENT CONVECTION WILL REMAIN ISOLATED
OVER SOUTHEAST IOWA AND MORE SCATTERED FROM THE QUAD CITIES TO THE
NORTH AND EAST. RAP TRENDS INDICATE THIS CONVECTION WILL PERSIST
INTO THE LATE AFTERNOON AND EARLY EVENING IN THE FAR EASTERN AND
SOUTHERN SECTIONS OF THE CWFA.
THE APPROACHING SHORTWAVE ACROSS MINNESOTA IS ALLOWING CU TO
DEVELOP FROM SOUTHERN MINNESOTA INTO NORTHERN IOWA. RADAR SHOWS NO
CONVECTION AS YET BUT WITH PEAK HEATING OCCURRING CONVECTION MAY
DEVELOP IN THE NEXT COUPLE OF HOURS. IF THIS OCCURS...THEN IT MAY
GET INTO THE HWY 20 CORRIDOR THIS EVENING. NEARLY ALL CONVECTION
SHOULD DISSIPATE WITHIN A FEW HOURS AFTER SUNSET. HOWEVER...
CONVECTION DID PERSIST OVERNIGHT CLOSE TO THE SFC LOW AND UPPER
LOW. THUS IT IS POSSIBLE THAT SOME ISOLATED SHRA/TSRA MAY PERSIST
PAST MIDNIGHT THAT CATCHES THE NORTHEAST PART OF THE CWFA.
FRIDAY IS LOOKING TO BE QUITE NICE WITH TEMPERATURES NEAR NORMAL.
HUMIDITY LEVELS WILL ALSO BE LOW. ..08..
.LONG TERM...FRIDAY NIGHT THROUGH NEXT THURSDAY
HIGH PRESSURE BUILDS INTO THE REGION FRIDAY NIGHT AND SATURDAY TO
KEEP THINGS QUIET BOTH PERIODS. HOWEVER...SATURDAY NIGHT AND SUNDAY
A NICE WARM AIR ADVECTION SURGE WITH A WEAK SHORTWAVE MOVES ACROSS
THE AREA TO BRING SOME PRECIPITATION CHANCES TO THE AREA.
TEMPERATURES WILL BE COOLER THAN WHAT WE HAVE HAD RECENTLY...WITH
HIGHS IN THE 80S TO AROUND 90 BOTH DAYS.
SUNDAY NIGHT THROUGH MONDAY NIGHT A STRONGER SHORTWAVE COMES ALONG
TO INTERACT WITH A WEAK 850MB BAROCLINIC ZONE TO BRING SOME
PRECIPITATION CHANCES TO THE AREA. THERE IS ROUGH AGREEMENT WITH
THE MODELS...BUT WITH TIMING DIFFERENCES TO ADD SOME CONFUSION.
HIGHS MONDAY TO BEGIN CREEPING UP...RISING INTO THE MID 80S TO LOW
90S.
TUESDAY THROUGH WEDNESDAY MODELS ARE IN GENERAL AGREEMENT THAT A
SURFACE RIDGE WILL BUILD ACROSS THE REGION...WHICH IS NOT ESPECIALLY
FAVORABLE FOR PRECIPITATION CHANCES...SO HAVE KEPT THOSE DRY OR AT
MOST SLIGHT CHANCE. HIGHS REMAIN IN THE 80S TO LOW 90S WITH THE
CONTINUING NORTHWEST FLOW ALOFT AND ENOUGH MOISTURE AT MID LEVELS TO
PRODUCE SOME MID CLOUDS.
THURSDAY WE HAVE A WEAK COLD FRONT AND HINTS AT AN UPPER LEVEL
SHORTWAVE TO MOVE THROUGH THE AREA...THOUGH MODELS HAVE A LOT OF
DIFFERENCES AND CONFIDENCE IS NOT VERY HIGH. HOWEVER...IT WAS
ENOUGH TO PUT IN TO CARRY SOME LOW END CHANCE POPS.
LE
&&
.AVIATION...
CONVECTION HAS INITIATED ON A FRONT/BOUNDARY FROM NORTHWEST
ILLINOIS INTO SOUTHEAST IOWA. RAP MODEL TRENDS SUGGEST TRSA MAY
AFFECT KMLI/KBRL THROUGH 00Z/27. POST FRONTAL CONVECTION WILL BE
POSSIBLE THROUGH 03Z/27 THAT MIGHT AFFECT KCID/KDBQ. AFT 03Z/27
GENERALLY VFR WX IS EXPECTED. THERE IS THE POSSIBILITY OF SOME
MVFR VSBYS DVLPG ARND SUNRISE FRIDAY BUT WAS NOT INCLUDED IN THE
18Z TAFS. ..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
213 PM CDT THU JUL 26 2012
.MESOSCALE UPDATE...
DIFFERENTIAL HEATING ALONG A BOUNDARY RUNNING FROM KVOK TO NEAR
KLWD AT 18Z COMBINED WITH DIFFERENTIAL HEATING IS ALLOWING
CONVECTION TO DEVELOP. THE BOUNDARY MAY BE A VERY DIFFUSE COLD
FRONT AS DEW POINTS DROP RATHER QUICKLY BEHIND IT. RAP TRENDS FROM
THE LIFT TOOL INDICATE A SMALL THETA E GRADIENT ALONG THE FRONT.
THE STRONGEST CONVERGENCE IS PROGGED TO BE OVER NORTHWEST ILLINOIS
THAT MOVES INTO NORTHEAST ILLINOIS OVER THE NEXT FEW HOURS.
THE MORE NUMEROUS CONVECTION SHOULD BE OVER JO
DAVIESS...STEPHENSON...AND CARROLL COUNTIES IN ILLINOIS WITH MORE
ISOLATED CONVECTION FROM JACKSON...CLINTON...AND CEDAR COUNTIES IN
ILLINOIS. ..08..
&&
.AVIATION... /ISSUED 1233 PM CDT THU JUL 26 2012/
LINGERING MVFR CONDITIONS WILL GIVE WAY TO VFR CONDITIONS BY
21Z/26. DENSITY ALTITUDES MAY APPROACH OR EXCEED 3 KFT THROUGH
01Z/27. VCTS WAS INCLUDED IN ALL 18Z TAFS FOR POSSIBLE DIURNAL
CONVECTION DVLPG AFT 21Z/26. HOWEVER...AREAL COVERAGE MAY BE 10
PERCENT OR LESS. IF A TSRA WOULD IMPACT A TAF SITE...BRIEF MVFR
CONDITIONS ARE EXPECTED. AFT 03Z/27 VFR CONDITIONS ARE EXPECTED.
THERE MAY OR MAY NOT BE MVFR VSBYS AROUND SUNRISE FROM FG. IF FG
WOULD DVLP...KCID/KDBQ MAY HAVE A BETTER CHANCE DUE TO WET GROUND
FROM RECENT RAINFALL. ..08..
&&
.PREV DISCUSSION... /ISSUED 1024 AM CDT THU JUL 26 2012/
UPDATE...
RADAR AND RAP TRENDS INDICATE THE LINGERING SHRA/SPRINKLES SHOULD
DISSIPATE BY MID DAY. POST FRONTAL CLOUDS HAVE DEVELOPED ACROSS
PART OF THE AREA WHICH MAY LIMIT THE AMOUNT OF WARMING THIS
AFTERNOON. HOWEVER...THE SUBSIDENCE DEVELOPING BEHIND THE
DEPARTING VORT MAX SHOULD ALLOW CLOUDS TO CLEAR OUT AND ALLOW
TEMPERATURES TO WARM.
ATTENTION THEN TURNS TO THE POTENTIAL FOR DIURNAL CONVECTION THIS
AFTERNOON. IF THE RAP MODEL IS CORRECT THERE WILL BE A LULL IN ANY
PRECIPITATION UNTIL CONVECTIVE TEMPERATURE IS ACHIEVED THIS
AFTERNOON. RAP TRENDS SUGGEST CONVECTIVE TEMPERATURES IN THE UPPER
80S TO LOWER 90S WHICH IS AROUND THE MAX TEMPERATURES.
RIGHT NOW THE SITUATION IS NOT CLEAR. IF DIURNAL CONVECTION DOES
DEVELOP IT MAY BE ISOLATED IN NATURE AND MAY HOLD OFF UNTIL VERY
LATE IN THE AFTERNOON WITH THE APPROACH OF THE NEXT SHORTWAVE.
FOR NOW WILL CONTINUE WITH THE IDEA OF DIURNAL CONVECTION
DEVELOPING BUT LIMIT IT TO THE LATE AFTERNOON HOURS. ..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION...CORRECTED AVIATION...
NWS QUAD CITIES IA IL
1233 PM CDT THU JUL 26 2012
.AVIATION UPDATE...
LINGERING MVFR CONDITIONS WILL GIVE WAY TO VFR CONDITIONS BY 21Z/26.
DENSITY ALTITUDES MAY APPROACH OR EXCEED 3 KFT THROUGH 01Z/27. VCTS
WAS INCLUDED IN ALL 18Z TAFS FOR POSSIBLE DIURNAL CONVECTION DVLPG
AFT 21Z/26. HOWEVER...AREAL COVERAGE MAY BE 10 PERCENT OR LESS. IF A
TSRA WOULD IMPACT A TAF SITE...BRIEF MVFR CONDITIONS ARE EXPECTED.
AFT 03Z/27 VFR CONDITIONS ARE EXPECTED. THERE MAY OR MAY NOT BE MVFR
VSBYS AROUND SUNRISE FROM FG. IF FG WOULD DVLP...KCID/KDBQ MAY HAVE
A BETTER CHANCE DUE TO WET GROUND FROM RECENT RAINFALL. ..08..
&&
.PREV DISCUSSION... /ISSUED 1024 AM CDT THU JUL 26 2012/
UPDATE...
RADAR AND RAP TRENDS INDICATE THE LINGERING SHRA/SPRINKLES SHOULD
DISSIPATE BY MID DAY. POST FRONTAL CLOUDS HAVE DEVELOPED ACROSS
PART OF THE AREA WHICH MAY LIMIT THE AMOUNT OF WARMING THIS
AFTERNOON. HOWEVER...THE SUBSIDENCE DEVELOPING BEHIND THE
DEPARTING VORT MAX SHOULD ALLOW CLOUDS TO CLEAR OUT AND ALLOW
TEMPERATURES TO WARM.
ATTENTION THEN TURNS TO THE POTENTIAL FOR DIURNAL CONVECTION THIS
AFTERNOON. IF THE RAP MODEL IS CORRECT THERE WILL BE A LULL IN ANY
PRECIPITATION UNTIL CONVECTIVE TEMPERATURE IS ACHIEVED THIS
AFTERNOON. RAP TRENDS SUGGEST CONVECTIVE TEMPERATURES IN THE UPPER
80S TO LOWER 90S WHICH IS AROUND THE MAX TEMPERATURES.
RIGHT NOW THE SITUATION IS NOT CLEAR. IF DIURNAL CONVECTION DOES
DEVELOP IT MAY BE ISOLATED IN NATURE AND MAY HOLD OFF UNTIL VERY
LATE IN THE AFTERNOON WITH THE APPROACH OF THE NEXT SHORTWAVE.
FOR NOW WILL CONTINUE WITH THE IDEA OF DIURNAL CONVECTION
DEVELOPING BUT LIMIT IT TO THE LATE AFTERNOON HOURS. ..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1224 PM CDT THU JUL 26 2012
.AVIATION...
LINGERING MVFR CONDITIONS WILL GIVE WAY TO VFR CONDITIONS BY
21Z/26. VCTS WAS INCLUDED IN ALL 18Z TAFS FOR POSSIBLE DIURNAL
CONVECTION DVLPG AFT 21Z/26. HOWEVER...AREAL COVERAGE MAY BE 10
PERCENT OR LESS. IF A TSRA WOULD IMPACT A TAF SITE...BRIEF MVFR
CONDITIONS ARE EXPECTED. AFT 03Z/27 VFR CONDITIONS ARE EXPECTED.
THERE MAY OR MAY NOT BE MVFR VSBYS AROUND SUNRISE FROM FG. IF FG
WOULD DVLP...KCID/KDBQ MAY HAVE A BETTER CHANCE DUE TO WET GROUND
FROM RECENT RAINFALL. ..08..
&&
.PREV DISCUSSION... /ISSUED 1024 AM CDT THU JUL 26 2012/
UPDATE...
RADAR AND RAP TRENDS INDICATE THE LINGERING SHRA/SPRINKLES SHOULD
DISSIPATE BY MID DAY. POST FRONTAL CLOUDS HAVE DEVELOPED ACROSS
PART OF THE AREA WHICH MAY LIMIT THE AMOUNT OF WARMING THIS
AFTERNOON. HOWEVER...THE SUBSIDENCE DEVELOPING BEHIND THE
DEPARTING VORT MAX SHOULD ALLOW CLOUDS TO CLEAR OUT AND ALLOW
TEMPERATURES TO WARM.
ATTENTION THEN TURNS TO THE POTENTIAL FOR DIURNAL CONVECTION THIS
AFTERNOON. IF THE RAP MODEL IS CORRECT THERE WILL BE A LULL IN ANY
PRECIPITATION UNTIL CONVECTIVE TEMPERATURE IS ACHIEVED THIS
AFTERNOON. RAP TRENDS SUGGEST CONVECTIVE TEMPERATURES IN THE UPPER
80S TO LOWER 90S WHICH IS AROUND THE MAX TEMPERATURES.
RIGHT NOW THE SITUATION IS NOT CLEAR. IF DIURNAL CONVECTION DOES
DEVELOP IT MAY BE ISOLATED IN NATURE AND MAY HOLD OFF UNTIL VERY
LATE IN THE AFTERNOON WITH THE APPROACH OF THE NEXT SHORTWAVE.
FOR NOW WILL CONTINUE WITH THE IDEA OF DIURNAL CONVECTION
DEVELOPING BUT LIMIT IT TO THE LATE AFTERNOON HOURS. ..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1024 AM CDT THU JUL 26 2012
.UPDATE...
RADAR AND RAP TRENDS INDICATE THE LINGERING SHRA/SPRINKLES SHOULD
DISSIPATE BY MID DAY. POST FRONTAL CLOUDS HAVE DEVELOPED ACROSS
PART OF THE AREA WHICH MAY LIMIT THE AMOUNT OF WARMING THIS
AFTERNOON. HOWEVER...THE SUBSIDENCE DEVELOPING BEHIND THE
DEPARTING VORT MAX SHOULD ALLOW CLOUDS TO CLEAR OUT AND ALLOW
TEMPERATURES TO WARM.
ATTENTION THEN TURNS TO THE POTENTIAL FOR DIURNAL CONVECTION THIS
AFTERNOON. IF THE RAP MODEL IS CORRECT THERE WILL BE A LULL IN ANY
PRECIPITATION UNTIL CONVECTIVE TEMPERATURE IS ACHIEVED THIS
AFTERNOON. RAP TRENDS SUGGEST CONVECTIVE TEMPERATURES IN THE UPPER
80S TO LOWER 90S WHICH IS AROUND THE MAX TEMPERATURES.
RIGHT NOW THE SITUATION IS NOT CLEAR. IF DIURNAL CONVECTION DOES
DEVELOP IT MAY BE ISOLATED IN NATURE AND MAY HOLD OFF UNTIL VERY
LATE IN THE AFTERNOON WITH THE APPROACH OF THE NEXT SHORTWAVE.
FOR NOW WILL CONTINUE WITH THE IDEA OF DIURNAL CONVECTION
DEVELOPING BUT LIMIT IT TO THE LATE AFTERNOON HOURS. ..08..
&&
.AVIATION...
CONSIDERABLE POST FRONTAL MVFR CIGS HAVE DVLPD ACRS IOWA AND THESE
ARE EXPECTED TO CONTINUE THROUGH 18Z/26. AFT 18Z/26 MVFR CIGS
SHOULD BREAK UP ALLOWING VFR CONDITIONS THROUGH 00Z/27. THERE IS A
POSSIBILITY OF DIURNAL CONVECTION DVLPG AFT 20Z/26. THE POTENTIAL
WILL BE THERE BUT COVERAGE MAY ONLY WARRANT VCSH OR VCTS IN THE
18Z TAFS. ..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
330 PM EDT THU JUL 26 2012
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 300 PM EDT THU JUL 26 2012
CHALLENGING FORECAST FOR THE SHORT TERM. BEST DYNAMICS AND FORCING REMAIN
TO THE NORTH OF OUR AREA AT THIS TIME...BUT WITH CONTINUED INSOLATION
FOR SEVERAL MORE HOURS AIR MASS OVER EAST KY WILL CONTINUE TO
DESTABILIZE. LATEST GOES SOUNDER SHOWS LIFTED INDICES FROM -3 TO -5
OVER AREA...AND PLENTY OF LOW LEVEL MOISTURE IS IN PLACE WITH
DEWPOINTS IN THE LOWER TO MIDDLE 70S.
HOWEVER THE WINDOW FOR SEVERE WEATHER IN EAST KY LOOKS VERY LIMITED
DUE TO TIMING OF WHEN CONVECTION SHOULD ENTER THE AREA. BEST ESTIMATE
AT THIS TIME IS FOR CONVECTION TO ENTER THE FAR NORTH AROUND 8 PM.
WITH BEST FORCING REMAINING NORTH OF THE AREA AND THE FACT THAT WE
WILL BE LOSING DAYTIME HEATING DO NOT EXPECT CONVECTION THAT ENTERS
OUR AREA TO MAINTAIN SEVERE CHARACTERISTICS...IF IT IS SEVERE TO
BEGIN WITH...VERY FAR SOUTH AND EAST INTO THE FORECAST AREA.
THERE IS ALSO A WIDE RANGE OF MODEL SOLUTIONS FOR THE NEAR
TERM AS TO TIMING AND EXTENT OF SHOWERS AND THUNDERSTORMS TONIGHT AND
AGAIN ON FRIDAY INTO FRIDAY EVENING. FOR THE VERY NEAR TERM HAD BEEN
FAVORING THE HRRR WHICH HAD BEEN VERY CONSISTENT WITH SEVERAL RUNS IN
A ROW SHOWING THE SHOWERS AND THUNDERSTORMS MOVING INTO THE FAR
NORTH PART OF OUR AREA AROUND 01Z. HOWEVER THE LATEST...15Z RUN IS
KEEPING MOST OF OUR AREA DRY THROUGH 06Z. FOR NOW HAVE GONE WITH A
BLEND OF NEIGHBORING FORECAST OFFICE TIMING...CURRENT RADAR
TRENDS...ANALYSIS AND MODEL BLENDS.
ALL CONVECTION TONIGHT WILL BE PRE FRONTAL...AND WITH THE FRONT YET
TO PUSH INTO OUR AREA ON FRIDAY...ADDITIONAL THUNDERSTORMS WILL BE
POSSIBLE YET AGAIN...AS UPPER SHORT WAVE TROF MOVES ACROSS THE LAKES
AND OH VALLEY. THE 12Z NAM IS THE MOST AGGRESSIVE WITH THIS
IDEA...AND SPC HAS PLACED OUR ENTIRE AREA IN A SLIGHT RISK FOR
FRIDAY. THERE IS CONSIDERABLE QUESTION AS TO HOW MUCH INSTABILITY
WILL BE PRESENT ON FRIDAY THOUGH. WILL CARRY THUNDERSTORM CHANCES ON
FRIDAY FOR ONGOING MORNING CONVECTION AND ALSO CHANCE FOR
REDEVELOPMENT IN THE AFTERNOON...AND WILL CARRY SLIGHT CHANCE TO
CHANCE INTO FRIDAY NIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 330 PM EDT THU JUL 26 2012
THE PERIOD WILL BEGIN WITH AN UPPER LEVEL SHORTWAVE TROUGH PUSHING
EAST OF THE AREA WITH RISING HEIGHTS ACROSS THE REGION ON SAT. UPPER
LEVEL RIDGING WILL GENERALLY DOMINATE THE WEEKEND WITH SFC HIGH
PRESSURE BUILDING INTO THE OHIO VALLEY BEFORE SHIFTING EAST AT THE
END OF WEEKEND. HOWEVER...BY EARLY NEXT WEEK THE RIDGE BECOME
ESTABLISHED A BIT FURTHER SOUTHWEST IN THE SOUTHERN PLAINS WITH THE
REGION ENDING UP IN NW FLOW ALOFT BETWEEN THIS RIDGE AND TROUGHING
OVER THE GREAT LAKES...NORTHEAST AND DOWN ALONG THE EASTERN
SEABOARD. THIS OVERALL PATTERN WILL REMAIN UNCHANGED TROUGH THE END
OF THE PERIOD.
THIS SCENARIO WILL LEAD TO A RATHER QUIET AND PLEASANT PATTERN OVER
THE WEEKEND AND YIELD MORE ACTIVE WEATHER WITH THE THREAT OF
CONVECTION. THIS CONVECTION SHOULD LARGELY HAVE A DIURNAL COMPONENT
TO IT...BUT MCS NOCTURNAL CONVECTION WILL ALSO BE POSSIBLE. TIMING OF
THE THE GREATEST THREAT OF NOCTURNAL CONVECTION IS LOW ATTM...ALTHOUGH
MODELS TO POINT TOWARD SOME OF THIS POSSIBLY OCCURRING ON MON NIGHT.
WE WENT WITH SLIGHT CHANCE POPS IN THE SW LATE ON SUN NIGHT WITH
CHANCE POPS WITH THE DIURNAL FLAVOR FROM THEN ON.
AS FOR TEMPS...MAX TEMPS SHOULD AVERAGE NEAR NORMAL THROUGH THE
PERIOD...WITH THE GREATEST DEPARTURE IN OVERNIGHT LOWS FROM TUE NIGHT
ON. MIN T ON SAT NIGHT...IN THE LOW TO MID 60S MAY BE THE LOWEST
OBSERVED SO FAR THIS MONTH IN VALLEY LOCATIONS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 145 PM EDT THU JUL 26 2012
VFR CONDITIONS WILL PREVAIL THROUGH THE AFTERNOON AND INTO THE
EVENING...THOUGH THERE WILL BE WIND GUSTS TO AROUND 20 KNOTS FROM THE
SOUTHWEST. THUNDERSTORMS ARE EXPECTED TO MOVE INTO THE NORTHERN PART OF
THE FORECAST AREA AROUND 01Z IN ADVANCE OF AN APPROACHING COLD FRONT.
THUNDERSTORMS ARE THEN EXPECTED TO ADVANCE ACROSS THE FORECAST AREA
DURING THE OVERNIGHT PERIOD...WITH CONDITIONS TO MVFR OR IFR. ONCE
THE THUNDERSTORMS PASS EXPECT IFR TO MVFR CONDITIONS IN FOG AND LOW
CLOUD TO PERSIST INTO THE DAY ON FRIDAY. CONDITIONS WILL IMPROVE BACK
TO VFR DURING THE DAY FRIDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR KYZ044-050>052.
&&
$$
SHORT TERM...SBH
LONG TERM....JP
AVIATION...SBH
AREA FORECAST DISCUSSION
NWS JACKSON KY
300 PM EDT THU JUL 26 2012
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 300 PM EDT THU JUL 26 2012
CHALLENGING FORECAST FOR THE SHORT TERM. BEST DYNAMICS AND FORCING REMAIN
TO THE NORTH OF OUR AREA AT THIS TIME...BUT WITH CONTINUED INSOLATION
FOR SEVERAL MORE HOURS AIR MASS OVER EAST KY WILL CONTINUE TO
DESTABILIZE. LATEST GOES SOUNDER SHOWS LIFTED INDICES FROM -3 TO -5
OVER AREA...AND PLENTY OF LOW LEVEL MOISTURE IS IN PLACE WITH
DEWPOINTS IN THE LOWER TO MIDDLE 70S.
HOWEVER THE WINDOW FOR SEVERE WEATHER IN EAST KY LOOKS VERY LIMITED
DUE TO TIMING OF WHEN CONVECTION SHOULD ENTER THE AREA. BEST ESTIMATE
AT THIS TIME IS FOR CONVECTION TO ENTER THE FAR NORTH AROUND 8 PM.
WITH BEST FORCING REMAINING NORTH OF THE AREA AND THE FACT THAT WE
WILL BE LOSING DAYTIME HEATING DO NOT EXPECT CONVECTION THAT ENTERS
OUR AREA TO MAINTAIN SEVERE CHARACTERISTICS...IF IT IS SEVERE TO
BEGIN WITH...VERY FAR SOUTH AND EAST INTO THE FORECAST AREA.
THERE IS ALSO A WIDE RANGE OF MODEL SOLUTIONS FOR THE NEAR
TERM AS TO TIMING AND EXTENT OF SHOWERS AND THUNDERSTORMS TONIGHT AND
AGAIN ON FRIDAY INTO FRIDAY EVENING. FOR THE VERY NEAR TERM HAD BEEN
FAVORING THE HRRR WHICH HAD BEEN VERY CONSISTENT WITH SEVERAL RUNS IN
A ROW SHOWING THE SHOWERS AND THUNDERSTORMS MOVING INTO THE FAR
NORTH PART OF OUR AREA AROUND 01Z. HOWEVER THE LATEST...15Z RUN IS
KEEPING MOST OF OUR AREA DRY THROUGH 06Z. FOR NOW HAVE GONE WITH A
BLEND OF NEIGHBORING FORECAST OFFICE TIMING...CURRENT RADAR
TRENDS...ANALYSIS AND MODEL BLENDS.
ALL CONVECTION TONIGHT WILL BE PRE FRONTAL...AND WITH THE FRONT YET
TO PUSH INTO OUR AREA ON FRIDAY...ADDITIONAL THUNDERSTORMS WILL BE
POSSIBLE YET AGAIN...AS UPPER SHORT WAVE TROF MOVES ACROSS THE LAKES
AND OH VALLEY. THE 12Z NAM IS THE MOST AGGRESSIVE WITH THIS
IDEA...AND SPC HAS PLACED OUR ENTIRE AREA IN A SLIGHT RISK FOR
FRIDAY. THERE IS CONSIDERABLE QUESTION AS TO HOW MUCH INSTABILITY
WILL BE PRESENT ON FRIDAY THOUGH. WILL CARRY THUNDERSTORM CHANCES ON
FRIDAY FOR ONGOING MORNING CONVECTION AND ALSO CHANCE FOR
REDEVELOPMENT IN THE AFTERNOON...AND WILL CARRY SLIGHT CHANCE TO
CHANCE INTO FRIDAY NIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 300 PM EDT THU JUL 26 2012
LONG TERM DISCUSSION WILL FOLLOW SHORTLY
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 145 PM EDT THU JUL 26 2012
VFR CONDITIONS WILL PREVAIL THROUGH THE AFTERNOON AND INTO THE
EVENING...THOUGH THERE WILL BE WIND GUSTS TO AROUND 20 KNOTS FROM THE
SOUTHWEST. THUNDERSTORMS ARE EXPECTED TO MOVE INTO THE NORTHERN PART OF
THE FORECAST AREA AROUND 01Z IN ADVANCE OF AN APPROACHING COLD FRONT.
THUNDERSTORMS ARE THEN EXPECTED TO ADVANCE ACROSS THE FORECAST AREA
DURING THE OVERNIGHT PERIOD...WITH CONDITIONS TO MVFR OR IFR. ONCE
THE THUNDERSTORMS PASS EXPECT IFR TO MVFR CONDITIONS IN FOG AND LOW
CLOUD TO PERSIST INTO THE DAY ON FRIDAY. CONDITIONS WILL IMPROVE BACK
TO VFR DURING THE DAY FRIDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR KYZ044-050>052.
&&
$$
SHORT TERM...SBH
LONG TERM....
AVIATION...SBH
AREA FORECAST DISCUSSION
NWS JACKSON KY
146 PM EDT THU JUL 26 2012
.UPDATE...
ISSUED AT 145 PM EDT THU JUL 26 2012
HAVE UPDATED NDFD FOR LATEST NEAR TERM TRENDS AND OBSERVATIONS. CAP
LOOKS TO INHIBIT CONVECTION FOR THE NEXT SEVERAL HOURS...BUT CAP
SHOULD ERODE BY LATE AFTERNOON. PAST SEVERAL RUNS OF THE HRRR HAVE
BEEN CONSISTENT WITH NO CONVECTION INITIATING IN OUR AREA THIS
AFTERNOON. IT HAS ALSO BEEN CONSISTENT WITH CONVECTION MOVING INTO
THE THE FAR NORTHERN PART OF THE FORECAST AREA AROUND 01Z. WITH BEST
DYNAMICS TO OUR NORTH AND LOSS OF DAYTIME HEATING NOT REAL CONFIDENT
IN SEVERE THREAT FOR THE OVERNIGHT PERIOD. STILL APPEARS THAT THE
BEST CHANCE FOR SEVERE STORMS WILL BE FAR NORTH WITH SHARP DECLINE IN
SEVERE THREAT THE FURTHER SOUTH YOU GO.
UPDATE ISSUED AT 1052 AM EDT THU JUL 26 2012
DEWPOINT POOLING IN THE FAR NORTH WILL LEAD TO HEAT INDEX VALUES NEAR
105 THIS AFTERNOON. HAVE ISSUED A HEAT ADVISORY FOR THE FAR NORTH
THROUGH 7 PM THIS EVENING. THIS WILL ALIGN WELL WITH NEIGHBORING HEAT
ADVISORIES AND WARNINGS.
12Z NAM POINTING TOWARDS PRIMARY THUNDERSTORM CHANCE DURING THE
OVERNIGHT PERIOD. THIS IS IN GOOD AGREEMENT WITH CURRENT FORECAST. THE
HRRR CONTINUES TO SHOW THE POTENTIAL FOR SCATTERED CONVECTION THIS
AFTERNOON...BUT WITH THE PRIMARY THUNDERSTORM THREAT BEGINNING AFTER
23Z.
SEVERE THREAT FOR OUR AREA LOOKS TO BE PRIMARILY THIS EVENING...WITH
CONVECTION WEAKENING DURING THE OVERNIGHT PERIOD. HAVE UPDATED
NDFD...HWO AND ZFP.
UPDATE ISSUED AT 710 AM EDT THU JUL 26 2012
JUST A QUICK UPDATE TO ESTABLISH TEMPS AND DEW PTS HEADING INTO THE
DAY. SOME MINOR ADJUSTMENTS WERE MADE IN THE BEGINNING OF THE LONG
TERM...MAINLY JUST TO MOVE POPS OUT A LITTLE QUICKER. WILL FRESHEN UP
THE ZFP. UPDATED GRIDS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 345 AM EDT THU JUL 26 2012
SFC ANALYSIS THIS MORNING SHOWS A LOW PRESSURE SYSTEM MOVING THROUGH
THE GREAT LAKES WITH A TRAILING COLD FRONT STRETCHED BACK ACROSS THE
MID MS VALLEY INTO THE SRN PLAINS. CONVECTION HAS BEEN RATHER
VIGOROUS IN THE VICINITY OF THE FRONT WHERE MOISTURE HAS POOLED ALONG
A PRE FRONTAL TROF. SAT IMAGERY THIS MORNING ALSO REVEALS A GOOD FETCH
OF MOISTURE FROM THE GULF OF MEXICO WITH PWATS AROUND 2 INCHES
ADVECTING INTO THE OHIO VALLEY ON A 35 KT LLJ EVIDENT ON THE JKL VAD
WIND PROFILE.
EXPECTING FOR THE MOST PART A BREEZY DAY ACROSS THE AREA AS THE
GRADIENT STRENGTHENS AHEAD OF THE APPROACHING FRONT. ONCE THE
NOCTURNAL INVERSION BREAKS THIS MORNING...LLJ MOMENTUM SHOULD BE ABLE
TO MIX DOWN TO THE SFC WITH SWLY WINDS GUSTING AROUND 25 KTS THROUGH
THE AFTERNOON...BOOSTING TEMPS INTO THE LOWER TO MID 90S. DEW PTS ARE
FCST TO SLIDE FROM THE LOWER/MID 70S INTO THE UPPER 60S THROUGH THE
DAY AS WINDS KEEP THINGS RELATIVELY MIXED...AND THIS SHOULD PREVENT
ANY HEAT ADVISORY CRITERIA FROM BEING REACHED TODAY...THOUGH WOULD
NOT BE TOO SURPRISED TO SEE A FEW LOCAL HEAT INDICES SNEAK INTO THE
TRIPLE DIGITS FOR AN HOUR OR SO THIS AFTERNOON.
CURRENT PROGS ARE GENERALLY IN GOOD AGREEMENT WITH BRINGING
CONVECTION ALONG THE PRE FRONTAL TROF INTO THE AREA THIS EVENING AND
WITH A RELATIVELY GOOD CONSENSUS CAN SEE LITTLE REASON TO ARGUE WITH
TIMING. FCST SOUNDINGS SHOW MODERATE INSTABILITY LINGERING THROUGH
THE OVERNIGHT HOURS AS THE TROF PUSHES THROUGH THE AREA...AND WILL
NOT RULE OUT ONE OR TWO STRONGER STORMS OVERNIGHT...ESPECIALLY IN THE
NORTH WHERE BETTER UPPER LEVEL DYNAMICS WILL RESIDE. THE MAIN
CONCERNS WILL BE DAMAGING WINDS AND LOCALIZED SHORT TERM HYDRO ISSUES
GIVEN THE RECENT RAINS...AND ANOMALOUS PWATS...AND A GOOD POTENTIAL
FOR TRAINING STORMS.
WE SHOULD SEE A BIT OF A LULL AT SOME POINT DURING THE DAY ON FRIDAY
AS THE TROF PUSHES EAST...BUT SOME SCATTERED CONVECTION WILL STILL BE
POSSIBLE THROUGH THE DAY AS THE FRONT BEGINS TO PUSH THROUGH THE
AREA. FCST SOUNDINGS SUGGEST THE PRIMARY THREAT WITH ANY OF THE
STRONGER TSTMS ON FRIDAY WOULD AGAIN BE DAMAGING WINDS.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 415 AM EDT THU JUL 26 2012
A MID/UPPER LEVEL TROUGH WILL BE OVER THE REGION AT THE START OF THE
PERIOD...WITH ITS ASSOCIATED COLD FRONT IN THE PROCESS OF JUMPING
THE APPALACHIANS. DRYING SHOULD BE UNDERWAY BY FRIDAY NIGHT...
ESPECIALLY IN THE MID/UPPER LEVELS...AS THE UPPER LEVEL SUPPORT FOR
PRECIP MOVES TO OUR SOUTHEAST. WILL LOOK FOR DRY WEATHER ON FRIDAY
NIGHT. SURFACE HIGH PRESSURE BEHIND THE COLD FRONT WILL THEN MOVE
EASTWARD ACROSS THE MIDWEST DURING THE WEEKEND...BRINGING US MAINLY
CLEAR SKIES AND SLIGHTLY LESS HUMID AIR.
THE HIGH PRESSURE WILL WEAKEN AND MOVE EAST OFF THE COAST ON
MONDAY...AS ANOTHER COLD FRONT HEADS SLOWLY SOUTHEAST THROUGH THE
MIDWEST. THE WIND FLOW BETWEEN THE COLD FRONT AND THE HIGH WILL
CARRY MOISTURE BACK INTO THE LOCAL AREA...WITH A RETURN OF PRECIP
POTENTIAL FROM MONDAY NIGHT FORWARD. THE HIGHEST POP WILL BE WITH
PEAK HEATING JUST AHEAD OF THE COLD FRONT ON TUESDAY. EVEN THOUGH THE
DEEPEST MOISTURE APPEARS TO SHIFT SOUTHEAST ON WEDNESDAY AND THE
SURFACE FRONT BEGINS TO TRANSITION ACROSS THE MOUNTAINS...THE SURFACE
AIR MASS MAY BE SLOWER AND MORE DIFFICULT TO CHANGE...AND SHOWERS AND
THUNDERSTORMS OF LESSER EXTENT ARE STILL A POSSIBILITY ON WEDNESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 145 PM EDT THU JUL 26 2012
VFR CONDITIONS WILL PREVAIL THROUGH THE AFTERNOON AND INTO THE
EVENING...THOUGH THERE WILL BE WIND GUSTS TO AROUND 20 KNOTS FROM THE
SOUTHWEST. THUNDERSTORMS ARE EXPECTED TO MOVE INTO THE NORTHERN PART OF
THE FORECAST AREA AROUND 01Z IN ADVANCE OF AN APPROACHING COLD FRONT.
THUNDERSTORMS ARE THEN EXPECTED TO ADVANCE ACROSS THE FORECAST AREA
DURING THE OVERNIGHT PERIOD...WITH CONDITIONS TO MVFR OR IFR. ONCE
THE THUNDERSTORMS PASS EXPECT IFR TO MVFR CONDITIONS IN FOG AND LOW
CLOUD TO PERSIST INTO THE DAY ON FRIDAY. CONDITIONS WILL IMPROVE BACK
TO VFR DURING THE DAY FRIDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR KYZ044-050>052.
&&
$$
UPDATE...SBH
SHORT TERM...MB
LONG TERM....HAL
AVIATION...SBH
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
426 PM EDT THU JUL 26 2012
.SYNOPSIS...
A SQUALL LINE OF SEVERE THUNDERSTORMS WILL MOVE THROUGH WITH
DAMAGING WIND, HEAVY RAIN, HAIL, AND LOTS OF LIGHTNING. THERE
WILL STILL BE SCATTERED THUNDERSTORMS AROUND THE UPPER OHIO VALLEY
UNTIL SATURDAY NIGHT, WHEN A SOUTHBOUND COLD FRONT BRINGS LOWER
HUMIDITY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
UPDATE MADE TO DROP HEAT ADVISORY WHERE THUNDERSTORMS HAVE COOLED
TEMPERATURES DOWN.
THE MAIN CONCERN THROUGH EVENING IS STILL THE PASSAGE OF A SQUALL
LINE OF SEVERE THUNDERSTORMS WITH DAMAGING WIND, HAIL, HEAVY RAIN,
AND LOTS OF LIGHTNING.
A FLASH FLOOD WATCH HAS BEEN ISSUED AS THE THUNDERSTORMS WITH
HEAVY RAIN WILL BE MOVING THROUGH URBAN AREAS, DURING EVENING
COMMUTE AND EVENING HOURS. IT MAY HAVE TO BE EXTENDED AND EXPANDED
IF LINES OF THUNDERSTORMS CONTINUE TO DEVELOP FARTHER WEST.
RAIN AMOUNTS OF MORE THAN 1.5 INCHES IN LESS THAN 3 HOURS CAN
CAUSE FLASH FLOODING IN URBAN AREAS AND WHERE DRAINAGE IS POOR. IF
MORE THAN 2.5 INCHES OCCUR, SERIOUS FLASH FLOODING CAN DEVELOP.
RECENT HRRR MODEL OUTPUT, ALONG WITH 12Z WRF-NMM MODEL OUTPUT,
INDEED SHOWS THERE CAN BE TWO OR THREE LINES OF THUNDERSTORMS.
HOWEVER, OUR OPINION IS THAT THE INITIAL LINE WILL HAVE THE
HIGHEST WIND GUSTS, WHILE THE LATTER LINES CAN CONTRIBUTE TO THE
RAINFALL TOTALS. WILL MONITOR AS MAY HAVE TO EXPAND THE AREA OF
CURRENT FLASH FLOOD WATCH.
LATEST TIMING OF STORMS
INDIANA-MORGANTOWN WV/ KIDI-KMGW/: 5-6PM.
OAKLAND MD/ K2G4/: 6-7PM.
SECOND LINE OF STORMS MAY AFFECT NEW PHILADELPHIA AND ZANESVILLE
AREA BETWEEN 5 AND 6 PM.
CONSIDERING THE TIMINGS, THE STORMS CAN IMPACT EVENING COMMUTERS
AND THOSE PARTICIPATING IN OUTDOOR EVENING ACTIVITIES.
CONTINUE TO EXPECT SCATTERED THUNDERSTORMS LATER TONIGHT IN THE
WAKE OF THESE LINES OF STORMS. PATCHY FOG MAY ALSO OCCUR.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
RECENT SREF MODEL OUTPUT, WITH DETAILS FROM 12Z NAM MODEL OUTPUT, SHOWS
HUMID AND HENCE UNSTABLE CONDITIONS REMAINING ACROSS THE UPPER
OHIO VALLEY UNTIL THE COLD FRONT, WITH LOWER DEW POINTS, MOVES
SOUTHWARD THROUGH AREA, SATURDAY NIGHT. THUS HAVE MAINTAINED A
CHANCE OF THUNDERSTORMS INTO SATURDAY EVENING. SUNDAY SHOULD BE
DRY.
FORECASTED TEMPERATURES USING BLEND OF RECENT GFS AND NAM MOS AND
SREF MEAN VALUES, WHICH INDICATED TEMPERATURES CONTINUING WARMER
THAN NORMAL, WITH DAYTIME HIGHS BY UP TO 5 DEGREES, AND EARLY
MORNING LOWS BY UP TO 10 DEGREES.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
EXPECT DRY CONDITIONS TO HOLD UNDER WEAK SURFACE HIGH PRESSURE
THROUGH MONDAY.
AN UPPER TROUGH IS PROGGED TO REMAIN OVER THE EAST COAST THROUGH
MUCH OF NEXT WEEK. MODELS CONTINUE TO HINT AT A SURFACE LOW MOVING
SLOWLY ALONG THE EAST COAST TUESDAY THROUGH THURSDAY...WHILE A
FRONTAL BOUNDARY APPROACHES FROM THE GREAT LAKES. PLAN TO KEEP
CHANCE POPS FOR SHOWERS AND THUNDERSTORMS MONDAY NIGHT INTO
THURSDAY.
FORECAST TEMPERATURES ARE CLOSE TO HPC GUIDANCE AND WILL BE
GENERALLY A FEW DEGREES ABOVE NORMAL THROUGH THE EXTENDED PERIOD.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
WILL CONTINUE TO AMEND TAFS, PERTAINING TO IFR RESTRICTIONS AND
POSSIBLE WIND GUSTS OVER 50 KTS, BASED ON MOVEMENT AND
DEVELOPMENT OF THE LINES OF THUNDERSTORMS THROUGH 02Z.
EXPECT COVERAGE OF THUNDERSTORMS TO DECREASE TO SCATTERED BY LATE
TONIGHT. POST-STORM FOG AND STRATUS MAY ALSO CAUSE A SHORT PERIOD OF
IFR RESTRICTIONS MAINLY FROM 08Z TO 12Z FRIDAY. SCATTERED SHOWERS
AND STORMS WITH OCCASIONAL RESTRICTIONS WILL CONTINUE OVER THE
REGION FRIDAY.
OUTLOOK...FRIDAY NIGHT THROUGH TUESDAY...
SCATTERED THUNDERSTORMS AND THE POTENTIAL FOR RESTRICTIONS WILL
REMAIN THROUGH SATURDAY AS AN UPPER TROUGH AND A SECONDARY FRONT
PUSH ACROSS THE UPPER OHIO VALLEY. DRY VFR CONDITIONS ARE EXPECTED
UNDER SURFACE HIGH PRESSURE SUNDAY AND MONDAY. INCREASING MOISTURE
ASSOCIATED WITH AN EAST COAST LOW WILL FUEL SCATTERED SHOWERS AND
THUNDERSTORMS TUESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...FLASH FLOOD WATCH UNTIL 10 PM EDT THIS EVENING FOR OHZ041-050-
059-069.
PA...FLASH FLOOD WATCH UNTIL 10 PM EDT THIS EVENING FOR PAZ013>016-
020>023-029-031-073>076.
HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR PAZ029-031-073-
075.
WV...FLASH FLOOD WATCH UNTIL 10 PM EDT THIS EVENING FOR WVZ001>004-
012-021-022.
HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR WVZ012-021-022.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
327 PM EDT THU JUL 26 2012
.SYNOPSIS...
A SQUALL LINE OF SEVERE THUNDERSTORMS WILL MOVE THROUGH WITH
DAMAGING WIND, HEAVY RAIN, HAIL, AND LOTS OF LIGHTNING. THERE
WILL STILL BE SCATTERED THUNDERSTORMS AROUND THE UPPER OHIO VALLEY
UNTIL SATURDAY NIGHT, WHEN A SOUTHBOUND COLD FRONT BRINGS LOWER
HUMIDITY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
THE MAIN CONCERN THROUGH EVENING WILL BE THE PASSAGE OF A SQUALL LINE
OF SEVERE THUNDERSTORMS WITH DAMAGING WIND, HAIL, HEAVY RAIN, AND
LOTS OF LIGHTNING.
SPC HAS UPGRADED THE ENTIRE AREA TO SEVERE
THUNDERSTORM WATCH UNTIL 10 PM, WITH WIDESPREAD DAMAGING
THUNDERSTORMS THE MOST PROBABLE SEVERE THUNDERSTORM HAZARD. WFO
PITTSBURGH HAS BEEN ISSUING SEVERE THUNDERSTORM WARNINGS BASED ON
RECENT RADAR DEVELOPMENTS.
A FLASH FLOOD WATCH HAS BEEN ISSUED AS THE THUNDERSTORMS WITH
HEAVY RAIN WILL BE MOVING THROUGH URBAN AREAS, DURING EVENING
COMMUTE AND EVENING HOURS. IT MAY HAVE TO BE EXTENDED AND EXPANDED
IF LINES OF THUNDERSTORMS CONTINUE TO DEVELOP FARTHER WEST.
HPC HAS HAD A SLIGHT RISK OF EXCESSIVE RAINFALL. RAIN AMOUNTS OF
MORE THAN 1.5 INCHES IN LESS THAN 3 HOURS CAN CAUSE FLASH FLOODING
IN URBAN AREAS AND WHERE DRAINAGE IS POOR. IF MORE THAN 2.5 INCHES
OCCUR, SERIOUS FLASH FLOODING CAN DEVELOP.
RECENT HRRR MODEL OUTPUT, ALONG WITH 12Z WRF-NMM MODEL OUTPUT,
INDEED SHOWS THERE CAN BE TWO OR THREE LINES OF THUNDERSTORMS.
HOWEVER, OUR OPINION IS THAT THE INITIAL LINE WILL HAVE THE
HIGHEST WIND GUSTS, WHILE THE LATTER LINES CAN CONTRIBUTE TO THE
DUBOIS-PITTSBURGH PA-WHEELING WV/ KDUJ-KPIT-KHLG/: 4-5PM.
INDIANA-MORGANTOWN WV/ KIDI-KMGW/: 4-6PM.
OAKLAND MD/ K2G4/: 5-7 PM.
CONSIDERING THE TIMINGS, THE STORMS CAN IMPACT EVENING COMMUTERS
AND THOSE PARTICIPATING IN OUTDOOR EVENING ACTIVITIES.
CONTINUE TO EXPECT SCATTERED THUNDERSTORMS LATER TONIGHT IN THE
WAKE OF THESE LINES OF STORMS. PATCHY FOG MAY ALSO OCCUR.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
RECENT SREF MODEL OUTPUT, WITH DETAILS FROM 12Z NAM MODEL OUTPUT, SHOWS
HUMID AND HENCE UNSTABLE CONDITIONS REMAINING ACROSS THE UPPER
OHIO VALLEY UNTIL THE COLD FRONT, WITH LOWER DEW POINTS, MOVES
SOUTHWARD THROUGH AREA, SATURDAY NIGHT. THUS HAVE MAINTAINED A
CHANCE OF THUNDERSTORMS INTO SATURDAY EVENING. SUNDAY SHOULD BE
DRY.
FORECASTED TEMPERATURES USING BLEND OF RECENT GFS AND NAM MOS AND
SREF MEAN VALUES, WHICH INDICATED TEMPERATURES CONTINUING WARMER
THAN NORMAL, WITH DAYTIME HIGHS BY UP TO 5 DEGREES, AND EARLY
MORNING LOWS BY UP TO 10 DEGREES.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
EXPECT DRY CONDITIONS TO HOLD UNDER WEAK SURFACE HIGH PRESSURE
THROUGH MONDAY.
AN UPPER TROUGH IS PROGGED TO REMAIN OVER THE EAST COAST THROUGH
MUCH OF NEXT WEEK. MODELS CONTINUE TO HINT AT A SURFACE LOW MOVING
SLOWLY ALONG THE EAST COAST TUESDAY THROUGH THURSDAY...WHILE A
FRONTAL BOUNDARY APPROACHES FROM THE GREAT LAKES. PLAN TO KEEP
CHANCE POPS FOR SHOWERS AND THUNDERSTORMS MONDAY NIGHT INTO
THURSDAY.
FORECAST TEMPERATURES ARE CLOSE TO HPC GUIDANCE AND WILL BE
GENERALLY A FEW DEGREES ABOVE NORMAL THROUGH THE EXTENDED PERIOD.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
WILL CONTINUE TO AMEND TAFS, PERTAINING TO IFR RESTRICTIONS AND
POSSIBLE WIND GUSTS OVER 50 KTS, BASED ON MOVEMENT AND
DEVELOPMENT OF THE LINES OF THUNDERSTORMS THROUGH 02Z.
EXPECT COVERAGE OF THUNDERSTORMS TO DECREASE TO SCATTERED BY LATE
TONIGHT. POST-STORM FOG AND STRATUS MAY ALSO CAUSE A SHORT PERIOD OF
IFR RESTRICTIONS MAINLY FROM 08Z TO 12Z FRIDAY. SCATTERED SHOWERS
AND STORMS WITH OCCASIONAL RESTRICTIONS WILL CONTINUE OVER THE
REGION FRIDAY.
OUTLOOK...FRIDAY NIGHT THROUGH TUESDAY...
SCATTERED THUNDERSTORMS AND THE POTENTIAL FOR RESTRICTIONS WILL
REMAIN THROUGH SATURDAY AS AN UPPER TROUGH AND A SECONDARY FRONT
PUSH ACROSS THE UPPER OHIO VALLEY. DRY VFR CONDITIONS ARE EXPECTED
UNDER SURFACE HIGH PRESSURE SUNDAY AND MONDAY. INCREASING MOISTURE
ASSOCIATED WITH AN EAST COAST LOW WILL FUEL SCATTERED SHOWERS AND
THUNDERSTORMS TUESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR OHZ039>041-
048>050-057>059-068-069.
FLASH FLOOD WATCH UNTIL 10 PM EDT THIS EVENING FOR OHZ041-050-
059-069.
PA...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR PAZ020-021-029-
031-073-075.
FLASH FLOOD WATCH UNTIL 10 PM EDT THIS EVENING FOR PAZ013>016-
020>023-029-031-073>076.
WV...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR WVZ001>004-012-
021-022.
FLASH FLOOD WATCH UNTIL 10 PM EDT THIS EVENING FOR WVZ001>004-
012-021-022.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
125 PM EDT THU JUL 26 2012
.SYNOPSIS...
EXPECT HOT AND HUMID CONDITIONS THIS AFTERNOON, UNTIL A SQUALL
LINE OF SEVERE THUNDERSTORMS MOVES THROUGH WITH DAMAGING WIND,
HAIL, HEAVY RAIN, AND LOTS OF LIGHTNING. THERE WILL STILL BE
SCATTERED THUNDERSTORMS AROUND THE UPPER OHIO VALLEY UNTIL
SATURDAY NIGHT, WHEN A SOUTHBOUND COLD FRONT BRINGS LOWER
HUMIDITY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE MAIN CONCERN THROUGH EVENING WILL BE THE PASSAGE OF A SQUALL LINE
OF SEVERE THUNDERSTORMS WITH DAMAGING WIND, HAIL, HEAVY RAIN, AND
LOTS OF LIGHTNING. SPC HAS UPGRADED THE ENTIRE AREA TO SEVERE
THUNDERSTORM WATCH UNTIL 10 PM, WITH WIDESPREAD DAMAGING
THUNDERSTORMS THE MOST PROBABLE SEVERE THUNDERSTORM HAZARD.
HPC HAS JOINED IN WITH A SLIGHT RISK OF EXCESSIVE RAINFALL. RAIN
AMOUNTS OF MORE THAN 1.5 INCHES IN LESS THAN 3 HOURS CAN CAUSE
FLASH FLOODING IN URBAN AREAS AND WHERE DRAINAGE IS POOR. AM
CONSIDERING FLASH FLOOD WATCH, BUT WANT TO SEE IF REPEAT
THUNDERSTORMS WILL OCCUR.
CONCUR WITH THESE FORECASTS BASED ON RECENT SREF AND RAP INSTABILITY
AND VERTICAL SHEAR PROFILES.
RECENT RADAR DATA SHOWS THE INITIAL LINE OF SEVERE THUNDERSTORMS
HAS DEVELOPED ACROSS NORTHWEST PA AND NORTHERN OH.
SATELLITE DATA SHOWS A BAND OF CUMULUS HAS DEVELOPED FROM
JOHNSTOWN PA TO MORGANTOWN WV TO PARKERSBURG WV /KJST-KMGW-KPKB,
BUT SO FAR THE CONVECTION HAS BEEN CAPPED. BUT WILL HAS TO BE MONITORED.
RECENT HRRR MODEL OUTPUT, ALONG WITH 12Z WRF-NMM MODEL OUTPUT,
THERE CAN BE TWO OR THREE LINES OF THUNDERSTORMS. HOWEVER, OUR
OPINION IS THAT THE INITIAL LINE WILL HAVE THE HIGHEST WIND GUSTS.
SO FOR CONTINUITY, HAVE MAINTAINED THE FOLLOWING TIMING OF SQUALL
LINE ONSET.
FRANKLIN PA TO ZANESVILLE OH/ KFKL-KZZV/: 2-4PM.
DUBOIS-PITTSBURGH PA-WHEELING WV/ KDUJ-KPIT-KHLG/: 3-5PM.
INDIANA-MORGANTOWN WV/ KIDI-KMGW/: 4-6PM.
OAKLAND MD/ K2G4/: 6 PM.
CONSIDERING THE TIMINGS, THE STORMS CAN IMPACT EVENING COMMUTERS
AND THOSE PARTICIPATING IN OUTDOOR EVENING ACTIVITIES.
CONTINUE TO EXPECT SCATTERED THUNDERSTORMS LATER TONIGHT IN THE
WAKE OF THESE LINES OF STORMS. PATCHY FOG MAY ALSO OCCUR.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
RECENT SREF MODEL OUTPUT, WITH DETAILS FROM 12Z NAM MODEL OUTPUT, SHOWS
HUMID AND HENCE UNSTABLE CONDITIONS REMAINING ACROSS THE UPPER
OHIO VALLEY UNTIL THE COLD FRONT, WITH LOWER DEW POINTS, MOVES
SOUTHWARD THROUGH AREA, SATURDAY NIGHT. THUS HAVE MAINTAINED A
CHANCE OF THUNDERSTORMS INTO SATURDAY EVENING. SUNDAY SHOULD BE
DRY.
FORECASTED TEMPERATURES USING BLEND OF RECENT GFS AND NAM MOS AND
SREF MEAN VALUES, WHICH INDICATED TEMPERATURES CONTINUING WARMER
THAN NORMAL, WITH DAYTIME HIGHS BY UP TO 5 DEGREES, AND EARLY
MORNING LOWS BY UP TO 10 DEGREES.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
EXPECT DRY CONDITIONS TO HOLD UNDER WEAK SURFACE HIGH PRESSURE
THROUGH MONDAY.
AN UPPER TROUGH IS PROGGED TO REMAIN OVER THE EAST COAST THROUGH
MUCH OF NEXT WEEK. MODELS CONTINUE TO HINT AT A SURFACE LOW MOVING
SLOWLY ALONG THE EAST COAST TUESDAY THROUGH THURSDAY...WHILE A
FRONTAL BOUNDARY APPROACHES FROM THE GREAT LAKES. PLAN TO KEEP
CHANCE POPS FOR SHOWERS AND THUNDERSTORMS MONDAY NIGHT INTO
WEDNESDAY AND THURSDAY.
FORECAST TEMPERATURES ARE CLOSE TO HPC GUIDANCE AND WILL BE
GENERALLY A FEW DEGREES ABOVE NORMAL THROUGH THE EXTENDED PERIOD.
&&
.AVIATION /17Z THURSDAY THROUGH MONDAY/...
EXPECT LINES OF THUNDERSTORMS TO DEVELOP ALONG OUTFLOW BOUNDARIES
FROM EARLIER CONVECTION...AS WELL AS ALONG AND AHEAD OF A COLD FRONT
MOVING INTO THE REGION. CONFIDENCE IS HIGH THAT MOST TERMINALS WILL
EXPERIENCE THUNDERSTORMS WITH COVERAGE INCREASING FROM NORTHWEST TO
SOUTHEAST AS THE AFTERNOON PROGRESSES. IFR RESTRICTIONS IN HEAVY
RAIN CAN BE ANTICIPATED AND SFC GUSTS IN EXCESS OF 50KT ARE POSSIBLE.
EXPECT COVERAGE OF THUNDERSTORMS TO DECREASE TO SCATTERED BY LATE
TONIGHT. POST-STORM FOG AND STRATUS MAY ALSO CAUSE A SHORT PERIOD OF
IFR RESTRICTIONS MAINLY FROM 08Z TO 12Z FRIDAY. SCATTERED SHOWERS
AND STORMS WITH OCCASIONAL RESTRICTIONS WILL CONTINUE OVER THE
REGION FRIDAY.
OUTLOOK...FRIDAY NIGHT THROUGH TUESDAY...
SCATTERED THUNDERSTORMS AND THE POTENTIAL FOR RESTRICTIONS WILL
REMAIN THROUGH SATURDAY AS AN UPPER TROUGH AND A SECONDARY FRONT
PUSH ACROSS THE UPPER OHIO VALLEY. DRY VFR CONDITIONS ARE EXPECTED
UNDER SURFACE HIGH PRESSURE SUNDAY AND MONDAY. INCREASING MOISTURE
ASSOCIATED WITH AN EAST COAST LOW WILL FUEL SCATTERED SHOWERS AND
THUNDERSTORMS TUESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR OHZ039>041-
048>050-057>059-068-069.
PA...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR PAZ020-021-029-
031-073-075.
WV...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR WVZ001>004-012-
021-022.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1251 PM EDT THU JUL 26 2012
.SYNOPSIS...
EXPECT HOT AND HUMID CONDITIONS THIS AFTERNOON, UNTIL A SQUALL
LINE OF SEVERE THUNDERSTORMS MOVES THROUGH WITH DAMAGING WIND,
HAIL, HEAVY RAIN, AND LOTS OF LIGHTNING. THERE WILL STILL BE
SCATTERED THUNDERSTORMS AROUND THE UPPER OHIO VALLEY UNTIL
SATURDAY NIGHT, WHEN A SOUTHBOUND COLD FRONT BRINGS LOWER
HUMIDITY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE MAIN CONCERN THROUGH EVENING WILL BE THE PASSAGE OF A SQUALL LINE
OF SEVERE THUNDERSTORMS WITH DAMAGING WIND, HAIL, HEAVY RAIN, AND
LOTS OF LIGHTNING.
SPC CONTINUES TO PROJECT A MODERATE RISK OF SEVERE THUNDERSTORMS
FOR THE ENTIRE UPPER OHIO VALLEY, WITH WIDESPREAD DAMAGING
THUNDERSTORMS THE MOST PROBABLE SEVERE THUNDERSTORM HAZARD.
HPC HAS JOINED IN WITH A SLIGHT RISK OF EXCESSIVE RAINFALL. RAIN
AMOUNTS OF MORE THAN 1.5 INCHES IN LESS THAN 3 HOURS CAN CAUSE
FLASH FLOODING IN URBAN AREAS AND WHERE DRAINAGE IS POOR.
CONCUR WITH THESE FORECASTS BASED ON RECENT SREF AND RAP INSTABILITY
AND VERTICAL SHEAR PROFILES.
RECENT SATELLITE DATA SHOWS THE LEADING EDGE OF THICKER CLOUDS/
FROM CLEVELAND TO CINCINNATI OHIO /KCLE-KCMH-KCVG/. ALSO A BAND OF
CUMULUS HAS DEVELOPED FROM JOHNSTOWN PA TO MORGANTOWN WV TO
PARKERSBURG WV /KJST-KMGW-KPKB. THE FORMER IS MORE LIKELY WHERE
THE SQUALL LINE WILL FORM, BUT THE LATTER HAS TO BE ALSO MONITORED.
RECENT HRRR MODEL OUTPUT, ALONG WITH 12Z WRF-NMM MODEL OUTPUT,
THERE CAN BE TWO OR THREE LINES OF THUNDERSTORMS. HOWEVER, OUR
OPINION IS THAT THE INITIAL LINE WILL HAVE THE HIGHEST WIND GUSTS.
SO FOR CONTINUITY, HAVE MAINTAINED THE FOLLOWING TIMING OF SQUALL
LINE ONSET.
FRANKLIN PA TO ZANESVILLE OH/ KFKL-KZZV/: 2-4PM.
DUBOIS-PITTSBURGH PA-WHEELING WV/ KDUJ-KPIT-KHLG/: 3-5PM.
INDIANA-MORGANTOWN WV/ KIDI-KMGW/: 4-6PM.
OAKLAND MD/ K2G4/: 6 PM.
CONSIDERING THE TIMINGS, THE STORMS CAN IMPACT EVENING COMMUTERS
AND THOSE PARTICIPATING IN OUTDOOR EVENING ACTIVITIES.
CONTINUE TO EXPECT SCATTERED THUNDERSTORMS LATER TONIGHT IN THE
WAKE OF THESE LINES OF STORMS. PATCHY FOG MAY ALSO OCCUR.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
RECENT SREF MODEL OUTPUT, WITH DETAILS FROM 12Z NAM MODEL OUTPUT, SHOWS
HUMID AND HENCE UNSTABLE CONDITIONS REMAINING ACROSS THE UPPER
OHIO VALLEY UNTIL THE COLD FRONT, WITH LOWER DEW POINTS, MOVES
SOUTHWARD THROUGH AREA, SATURDAY NIGHT. THUS HAVE MAINTAINED A
CHANCE OF THUNDERSTORMS INTO SATURDAY EVENING. SUNDAY SHOULD BE
DRY.
FORECASTED TEMPERATURES USING BLEND OF RECENT GFS AND NAM MOS AND
SREF MEAN VALUES, WHICH INDICATED TEMPERATURES CONTINUING WARMER
THAN NORMAL, WITH DAYTIME HIGHS BY UP TO 5 DEGREES, AND EARLY
MORNING LOWS BY UP TO 10 DEGREES.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
MEDIUM RANGE MODELS SHOW SURFACE HIGH PRESSURE AND DRY CONDITIONS
FOR MONDAY.
AN UPPER TROUGH IS PROGGED TO REMAIN OVER THE EAST COAST EARLY
NEXT WEEK. MODELS HINT AT A SURFACE LOW MOVING ALONG THE EAST
COAST TUESDAY AND WEDNESDAY. PLAN TO KEEP CHANCE POPS FOR SHOWERS
AND THUNDERSTORMS MONDAY NIGHT THROUGH WEDNESDAY.
FORECAST TEMPERATURES ARE CLOSE TO HPC GUIDANCE AND WILL BE
GENERALLY A FEW DEGREES ABOVE NORMAL THROUGH THE EXTENDED PERIOD.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
THE MAIN FORECAST ISSUE WL BE THE DEVELOPMENT AND COVERAGE OF TSRA AS
OUTFLOW FM A GREAT LAKES MCS...AS WELL AS THE CDFNT MOVE TOWARD
THE REGION. CONFIDENCE IS HIGH THAT MOST PORTS WL EXPERIENCE
THUNDERSTORMS WITH COVERAGE INCREASING FM N TO S AS THE DAY
PROGRESSES. IFR RESTRICTIONS IN HEAVY RAIN CAN BE ANTICIPATED AND
SFC GUSTS IN EXCESS OF 50KT ARE POSSIBLE.
EXPECT NO MORE THAN SCATTERED THUNDERSTORMS THE REST OF TONIGHT.
POST-STORM STRATUS AND FOG MAY ALSO CAUSE A SHORT PERIOD OF IFR
RESTRICTIONS.
OUTLOOK...FRIDAY THROUGH MONDAY...
SCATTERED THUNDERSTORMS MAY PROVIDE RESTRICTIONS FRIDAY INTO
SATURDAY AS A SECONDARY FRONT PUSHES ACROSS THE TERMINALS. DRY VFR
CONDITIONS ARE EXPECTED UNDER SURFACE HIGH PRESSURE SUNDAY AND
MONDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR OHZ039>041-
048>050-057>059-068-069.
PA...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR PAZ020-021-029-
031-073-075.
WV...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR WVZ001>004-012-
021-022.
&&
$$
AREA FORECAST DISCUSSION
NWS GAYLORD MI
150 PM EDT THU JUL 26 2012
.SYNOPSIS...
ISSUED AT 1014 AM EDT THU JUL 26 2012
AFTER LOW PRESSURE AND ITS ATTENDANT SHWRS EXIT INTO LAKE HURON BY
1 PM...TODAY WILL FEATURE A BREAK IN THE ACTION. ANOTHER SYSTEM
WILL MOVE ACROSS NORTHERN MICHIGAN FRIDAY...BRINGING ANOTHER
ROUND OF SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL THEN BRING
PLEASANT WEATHER FOR THE WEEKEND. THERE WILL BE MORE CHANCES FOR
SHOWERS AND THUNDERSTORMS EARLY NEXT WEEK.
&&
.UPDATE...
ISSUED AT 150 PM EDT THU JUL 26 2012
TEMPS ARE SLOWLY RESPONDING TO THINNING STRATUS. DID ADJUST CLOUD
COVER UP THE REST OF THE DAYLIGHT HRS TO SIGNIFICANTLY SLOW DOWN
TRANSITION TO P/CLOUDY. DON`T EXPECT SUBSTANTIAL DECREASE IN CLDS
UNTIL LOSS OF HEATING 6-10 PM. HAD TO UPDATE FCST TO INCLUDE DRZL
AS UPSLOPE FLOW INCREASED IN WAKE OF DEPARTING SFC LOW. DRZL IS
NOW ENDING BUT AS SCT SHWRS DEVELOP S/E OF GRAYLING. SHOULD SEE
MORE AND MORE SUN AS AFTN WEARS ON. CURRENTLY NOT EXPECTING
ADDITIONAL CONVECTIVE DEVELOPMENT ALONG M-55 FROM HTL-CAD-MBL...
DESPITE TSTMS DEVELOPING OVER WI. CONFIDENCE IS LOW AS WE HAVE
CONFLICTING FCSTS OF CIN WITH NAM SOUNDINGS SUGGEST MODEST CAP
HOLDS. THE 14Z RAP SOUNDINGS INDICATE MID-LVL COOLING AN ITS
REMOVAL. 0-6 KM SHEAR 35 KTS...BUT AVERAGE MLCAPE OF 700 J/KG IS
NOT SUPPORTIVE OF SVR.
UPDATE ISSUED AT 1014 AM EDT THU JUL 26 2012
SFC LOW IS OVER ARENAC COUNTY AT 14Z AND WILL HEAD INTO SAGINAW
BAY OVER THE NEXT 2 HRS. 12Z UPR-AIR ANALYSIS SHOWS POSITIVE TILT
SHRTWV TROF MOVING THRU MI ATTM. COVERAGE OF SHWRS HAS BEEN INCRSG
S/E OF GRAYLING. THIS REQUIRES SOME MINOR RECONFIG OF POPS OVER
THE NEXT 3 HRS. PASSAGE OF TROF WILL CLEAR OUT MOST OF THE MID-
HIGH MSTR/CLOUDS AND END THE SHWRS. THIS WILL ALLOW INSOLATION/BL
HEATING TO BEGIN ERODING LOW STRATUS AND LIFTING IT INTO STRATOCU.
SKIES WILL EVENTUALLY TURN P/SUNNY. SEAS ARE STILL RUNNING AROUND
3 FT AT 45002. OTHER THAN NUDGING WAVE HGTS UP TO ACCT FOR THIS...
NO OTHER CHANGES WERE NEEDED.
UPDATE ISSUED AT 632 AM EDT THU JUL 26 2012
NO MAJOR CHANGES NEEDED TO GOING FORECAST...EARLIER ISSUANCE HAD
POPS ALONG/SOUTH OF M-55 CORRIDOR THROUGH 15Z AND IF ANYTHING
COULD NUDGE THAT LINE A FEW MILES NORTH BASED ON RADAR TRENDS.
CLOUDS/AREAS OF FOG PREVALENT ACROSS REMAINDER OF THE FORECAST AREA.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 415 AM EDT THU JUL 26 2012
MIDNIGHT SURFACE ANALYSIS IS A BIT OF A MESS GIVEN THE EXTENSIVE
LINE OF CONVECTION EXTENDING FROM THE GREAT LAKES SOUTHWEST INTO THE
CENTRAL/SOUTHERN PLAINS. 999MB LOW WAS LOCATED NEAR MKE...WITH A
CONVECTIVELY ENHANCED BOUNDARY THAT RUNS FROM CENTRAL LOWER
MICHIGAN...SOUTHWEST ACROSS FEAR EASTERN IOWA/NORTHWEST MISSOURI/
EASTERN KANSAS. SEVERAL MESOHIGHS EVIDENT BEHIND THE BOUNDARY
ACROSS CENTRAL KANSAS...NORTHEAST IOWA...AND NORTHERN LOWER
MICHIGAN. SECOND COLD FRONT RUNS FROM A 1003MB SURFACE LOW OVER
NORTHWEST ONTARIO...SOUTH ACROSS MINNESOTA/NORTHWEST IOWA/EASTERN
NEBRASKA. SOME SCATTERED CONVECTION AHEAD OF THIS FRONT...WHICH IS
ASSOCIATED WITH A STRONGER SHORT WAVE OVER MANITOBA. RIGHT ENTRANCE
REGION FORCING ASSOCIATED WITH A 110KT JET STREAK OVER QUEBEC AIDING
CONVECTIVE DEVELOPMENT EARLY THIS MORNING...WITHIN A VERY MOIST AIR
MASS (1.50-2.00 INCH PRECIPITABLE WATER VALUES). MAIN CONVECTION
NOW SHIFTING SOUTH INTO CENTRAL LOWER MICHIGAN/SOUTHERN WISCONSIN
WHERE LOW LEVEL CONVERGENCE MAXIMIZED ALONG LOW LEVEL JET/CONFLUENCE
AXIS...WHILE KAPX VAD WIND PROFILE SHOWING DEEP LAYER WEST/NORTHWEST
FLOW ACROSS NORTHERN LOWER.
UPPER GREAT LAKES SURFACE LOW WILL PULL EAST RATHER QUICKLY THIS
MORNING...ALREADY GETTING STRONG PRESSURE FALLS (2-3MB/3H) OVER
SOUTHWEST ONTARIO AND SURFACE PRESSURE PATTERN IS ADJUSTING TO THAT
(LOW OVER SOUTHEAST WISCONSIN FILLING BENEATH 1-2MB/3H PRESSURE
RISES). EXPECT SURFACE LOW TO BE IN THE VICINITY OF LAKE ONTARIO BY
12Z. WILL BE WATCHING MANITOBA SHORT WAVE TROUGH DROPPING SOUTHEAST
TODAY ACROSS THE UPPER MIDWEST...WITH THIS FEATURE REACHING MICHIGAN
BY FRIDAY MORNING.
FOR TODAY...LOOKS LIKE THE BULK OF THE PRECIPITATION WILL BE SOUTH
OF THE M-55 CORRIDOR THIS MORNING...WILL MONITOR RADAR TRENDS AND
ADJUST HOW LONG WILL NEED TO KEEP A PRECIP MENTION IN FOR
GLADWIN/ARENAC COUNTIES THIS MORNING. LOW CLOUDS/FOG DEVELOPING TO
THE NORTH WITH PLENTY OF LOW LEVEL MOISTURE AROUND AFTER YESTERDAY`S
RAINS...AND THIS WILL CONTINUE TO DEVELOP/ADVECT SOUTHWARD THIS
MORNING. MAY EVEN GET SOME DRIZZLE OUT OF THIS FOR A TIME. LOW
CLOUD DECK MAY PERSIST INTO THIS AFTERNOON ESPECIALLY ACROSS
NORTHERN LOWER AS CLOUDS SLOWLY MIX THEIR WAY INTO AN SC DECK.
COULD END UP BEING A MOSTLY CLOUDY DAY ACROSS NORTHEAST LOWER...
WITH SOME MORE SUN LATER TODAY ACROSS EASTERN UPPER AND PARTS OF
NORTHWEST LOWER.
SHORT WAVE TROUGH MOVES INTO WESTERN UPPER AND WISCONSIN TONIGHT...
AND WILL PROBABLY KICK OFF SOME CONVECTION AHEAD OF IT ACROSS
WISCONSIN DURING THE AFTERNOON HOURS. STRONGER FORCING EXPECTED TO
SPREAD INTO NORTHERN MICHIGAN OVERNIGHT...INCREASING THE THREAT FOR
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM WEST TO EAST FROM
MIDNIGHT ONWARD (WILL KEEP LAKE HURON SHORELINE COUNTIES FROM APN
SOUTH DRY THROUGH THE NIGHT).
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 415 AM EDT THU JUL 26 2012
ANOTHER UPPER LEVEL LOW PRESSURE SYSTEM IS EXPECTED TO BRING
ADDITIONAL RAINFALL TO THE REGION FRIDAY. THE COMBINATION OF SLOWLY
RISING HEIGHTS AND HIGH PRESSURE BUILDING IN AT THE SURFACE IS THEN
EXPECTED TO BRING IN PLEASANT CONDITIONS FOR THE WEEKEND. ANOTHER
WEAKER TROUGH WILL BRING CHANCES FOR SHOWERS AND THUNDERSTORMS FOR
THE EARLY AND MIDDLE PARTS OF NEXT WEEK. THE MAIN LONG TERM FORECAST
CONCERNS REVOLVE AROUND POPS AND HIGH TEMPERATURES FRIDAY.
FRIDAY...THE UPPER LEVEL LOW NOW EVIDENT ON WATER VAPOR IMAGERY
ACROSS SOUTHERN MANITOBA SINKS SLOWLY SOUTHEASTWARD OVER THE NEXT 36
HOURS AND TRACKS ACROSS NORTHERN MICHIGAN DURING THE DAY ON FRIDAY.
AN AREA OF DIV-Q FORCING TRAVERSES THE FORECAST AREA WHILE MODEL
SOUNDINGS/CROSS SECTIONS SHOW ABUNDANT LOW/MID LEVEL MOISTURE. THIS
IS EXPECTED TO RESULT IN ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS.
THEREFORE HAVE INCREASED POPS TO BETWEEN HIGH LIKELY (NORTH) TO
CATEGORICAL (INLAND SOUTH). AM NOT EXPECTING ANY STORMS TO BECOME
SEVERE DUE TO THE COMBINATION OF LIMITED SURFACE HEATING AND LIGHT
WIND FIELDS ALOFT (MEAN 0-6KM BULK SHEAR ONLY ABOUT 20 KNOTS OR SO).
IN ADDITION...WITH DEEP CLOUD COVER ANTICIPATED...WILL CONTINUE WITH
MAX TEMPERATURES ONLY IN THE LOWER TO MIDDLE 70S.
SATURDAY AND SUNDAY...EXTENDED MODELS CONTINUE TO BE IN GOOD
AGREEMENT THAT THERE WILL BE BUILDING UPPER LEVEL HEIGHTS AS A RIDGE
OF HIGH PRESSURE MOVES IN FROM THE SOUTHWEST. THIS SHOULD LEAD TO A
NICE LITTLE STRETCH OF SUMMER WEATHER WITH HIGHS FOR BOTH SATURDAY
AND SUNDAY REACHING INTO THE UPPER 70S TO LOWER 80S. LOWS IN THE
COMFORTABLE 50S TO LOWER 60S.
SUNDAY NIGHT THROUGH WEDNESDAY...A WEAKER TROUGH OF LOW PRESSURE
MOVES INTO THE REGION RESULTING IN MORE CHANCES FOR SHOWERS AND
THUNDERSTORMS. HIGHS GENERALLY RANGING FROM THE UPPER 70S NORTH TO
THE MIDDLE 80S SOUTHEAST. LOWS IN THE LOWER AND MIDDLE 60S EACH
NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 150 PM EDT THU JUL 26 2012
THIS AFTN: MVFR AT MBL SHOULD BE DONE. EXPECT MVFR CIGS TO REMAIN
AT TVC...WITH PLN/APN IMPROVING FROM IFR CIGS TO MVFR. THERE IS
LOW POTENTIAL FOR APN TO REMAIN IFR. AS STRATUS CONTINUES TO THIN
EXPECT -RA TO END AT APN BY 20Z. WINDS NW-N-NE WILL REMAIN 10 KTS
OR LESS.
CIG CONFIDENCE: ABOVE AVG
VSBY CONFIDENCE: HIGH
WIND CONFIDENCE: HIGH
TIMING OF CHGS TO FLGT CONDS: AVG
TNGT: COMPLEX CLOUD EVOLUTION. EXPECT MUCH OF STRATUS/STRATOCU TO
DISSIPATE WITH LOSS OF HEATING 23-02Z. HOWEVER...CAN ENVISION ANY
MODEST IMPROVEMENT AT PLN/APN RAPIDLY DETERIORATING AS CLEARING IN
THE PRESENCE OF REMAINING HIGH MSTR WILL RESULT IN REDEVELOPMENT
OF LOW CIGS AND POSSIBLY BR/FOG. CLEARING AT MBL/TVC SHOULD ALSO
RESULT IN BR/FOG. HAVE INDICATED IFR VSBYS AFTER 06Z AT PLN/APN
WITH MVFR VSBYS TVC/MBL. WORST CASE SCENARIO: LIFR/VLIFR AT ALL
TERMINALS...BUT WITH HIGHEST PROB AT PLN/TVC. WIND BECOMES CALM.
CONFIDENCE BELOW AVG ALL ELEMENTS EXCEPT WIND.
SCT SHWRS MOVE IN WITH MVFR VSBYS POSSIBLE.
FRI THRU 18Z: WDSPRD MVFR-IFR CIGS/VSBYS LIKELY TO START. CURRENT
EXPECTATION IS SLOW IMPROVEMENT TO MVFR CIGS. SCT SHWRS CONTINUE.
ISOLD THUNDER IS POSSIBLE. CONFIDENCE AVG.
&&
.MARINE...
ISSUED AT 415 AM EDT THU JUL 26 2012
LOW PRESSURE OVER THE UPPER GREAT LAKES EARLY THIS MORNING WILL
SLIDE INTO THE LOWER GREAT LAKES TODAY...LEAVING BEHIND A GENERALLY
LIGHT NORTHERLY/CYCLONIC GRADIENT ACROSS THE UPPER LAKES TODAY
THROUGH TONIGHT. NOT EXPECTING WINDS TO BE AN ISSUE TODAY...PERHAPS
SOME RESIDUAL CHOPPINESS IN THE WAVES THIS MORNING ESPECIALLY FROM
MANISTEE-GRAND TRAVERSE LIGHT ON LAKE MICHIGAN...AND THE STRAITS-
FALSE DETOUR ZONE ON NORTHERN LAKE HURON.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...HALBLAUB
SYNOPSIS...AJS
SHORT TERM...JPB
LONG TERM...AJS
AVIATION...HALBLAUB
MARINE...JPB
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1214 PM CDT Thu Jul 26 2012
...UPDATED AVIATION DISCUSSION...
.DISCUSSION...
Short Term (Today through Saturday Night)...
After 34 days without significant precipitation at the WFO, the
sounds of a steady rain and a great lightning show have been nothing
short of a welcomed miracle. Leading gust front now washing out
along the leading edge of the CWA, with elevated post-frontal
convection being maintained ahead of several well defined radar MCV
circulations. Aided by a 25-30 knot low level jet ascending over the
gust front, expect scattered convection to persist for the next
several hours with sufficient CAPE for lightning restricted
generally along and south of a MCI-IRK line.
For today, several forecast challenges related to POPs/temperatures.
Upstream mid level closed low is still over srn Manitoba, positioned
well NW of earlier model placement. This will lead to a much later
upper wave passage across the CWA today. Although muddied by
convection and nocturnal effects, it appears that the effective cold
front is still located across srn Nebraska into central Iowa,
denoted by a modest wind shift and dewpoint gradient. Pre-frontal
dewpoints have approaches seasonal highs in the lower 70s, driven
primarily by precipitation. My concern is that once nocturnal
activity dissipates and convective cloud debris erodes, strong
daytime heating could occur in a very moist and uncapped warm sector
ahead of a rather diffuse surface frontal zone. Per 06Z NAM and
recent HRRR guidance, this theory is well supported, and have
decided to drag POPs back to the northwest. Depending on how quickly
cloud cover erodes, the airmass could support surface based
thunderstorm development as early as 18Z. Increasingly northwesterly
flow aloft (although considerably stronger over the Ohio Valley)
could support some storm organization with an attendant threat for
damaging winds if activity grows upscale before exiting the CWA.
Temperatures will be highly conditional on the erosion of cloud
cover and subsequent convective development, but will opt for
lower-mid 90s as a hedge, with cooler readings certainly not out of
the question. Although on paper this seems like a huge improvement
from the past few weeks, the considerable increase in boundary layer
dewpoints will lead to a very humid conditions and heat indices
locally around 100 degrees.
With the frontal passage tonight, northwest upper flow will become
temporarily established over the area as the mean ridge position
reorganized over the southern High Plains. Seasonably strong
mid-upper flow will yield a rather impressive elevated baroclinic
zone over the region, which will translate to the surface with
daytime mixing. Have adjusted temperatures both Friday and Saturday
to account for this gradient, with hot temperatures persisting over
west central MO/ern KS and notably more tolerable conditions over NE
MO. This gradient becomes even more impressive Saturday and would
not be surprised to see highs in the upper 80s over NE MO vs. lower
100s over and south of Kansas City. Along with the brief intrusion
of cooler air into portions of the area, it is possible that
dewpoints Fri/Sat could be even lower than forecast, with some
guidance suggesting they fall into the lower 50s.
To further complicate matters, there is justifiable concern about
MCS activity on Saturday into Saturday Night. Most 00Z guidance show
a Pacific shortwave emerging from the Rockies Friday evening,
sparking a convective complex over the Black Hills region. The sharp
elevated baroclinic zone/instability axis would suggest this complex
would be well maintained along an ESE track, reaching nrn MO
Saturday afternoon. Meanwhile, the ridge will continue to
strengthen, helping return that frontal zone north as a warm front.
Thus, the question remains whether the edge of the cap is across nrn
MO or back into Iowa by the time this system arrives. Low chance
POPs probably the best way to go for now, although this will
probably end up being an all or nothing event once it draws closer.
Bookbinder
Medium Range (Sunday through Wednesday)...
Sunday - Monday: A upper level ridge of high pressure will extend
from the Southern Plains northwestward into the Eastern Rockies.
This will leave the area under northwesterly flow aloft. A series of
shortwaves are progged to round this ridge and move into the local
area on Sunday and Monday. This will make for a challenging forecast
through this period. The best chances for precipitation will be
mainly across the northern and eastern half of the CWA through
Monday although a complex of thunderstorms could develop on Sunday
and bring the chance for thunderstorms to the southern half of the
CWA as well and as such kept slight chance POPs across the southern
portion of the forecast area on Sunday. These system will also make
forecasting temperatures challenging with the northern CWA being
cooler with the potential for precipitation and excess cloud cover.
Thusly for Sunday and Monday have a gradient of temperatures ranging
from the lower 90s across north central Missouri sloping to the
upper 90s across east central Kansas and west central Missouri.
Tuesday - Wednesday: The upper level ridge will shift slowly
eastward with the local area moving under its influence by Tuesday.
This in turn will keep the local area dry through the period.
Temperatures on the other hand will warm a bit as height rises
through the period will help temperatures warm into the mid 90s to
near 100.
73
&&
.AVIATION...
Mid level cloud cover and associated showers are currently moving
south of the terminals at the moment and skies should clear in the
next hour or so. Short term guidance continues to suggest additional
convection developing later this afternoon along the cold front that
is currently located across northern Missouri. Will hold off on
mentioning this at the moment as confidence is not high enough to
support it.
Deroche
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
406 PM CDT THU JUL 26 2012
.DISCUSSION...
A FAIRLY STRONG COLD FRONT ACROSS SD THIS AFTN IS PROGGED TO DROP
THROUGH SWRN NEB THIS EVENING AND BECOME STATIONARY ALONG THE KS
BORDER FRIDAY MORNING. THE FRONT...MARGINAL INSTABILITY...STRONG
SHEAR...30 TO 40 KTS OF BULK SHEAR RESULTING IN BULK RICHARDSON
NUMBER NEAR 25 AND SFC DEW POINTS IN THE LOWER 50S SUGGEST ISOLATED
HIGH BASED STORM COVERAGE SHOULD ANYTHING FORM. BOTH THE HRRR AND
RAP13 ARE VERY AMBITIOUS SHOWING SCATTERED STORM COVERAGE FROM 20Z
ONWARD.
THE FRONT WILL LIFT NORTH INTO NCNTL NEB FRIDAY AND ACT AS A FOCUS
FOR ISOLATED LATE AFTN AND EVENING HIGH BASED TSTMS GIVEN LOW SFC
DEW POINTS. TEMPS ALONG AND WEST OF HIGHWAY 83 SHOULD RECOVER WITH
HIGHS IN THE MID AND UPPER 90S.
INCREASING LOW LEVEL FLOW...DEEPENING LOW PRESSURE ACROSS THE NRN
HIGH PLAINS AND VERY DEEP MOISTURE ABOVE 700 MB IS EXPECTED TO
PRODUCE A ROUND OF SCATTERED HIGH BASED TSTMS...POSSIBLY PRODUCING
WIND DAMAGE AS THEY MOVE EAST ACROSS THE FCST AREA FRIDAY NIGHT
INTO SATURDAY MORNING. THIS AREA OF STORMS MOVES TO NEAR KOMA BY
12Z SATURDAY AND THE WARM FRONT ADVANCES NORTH AND EAST TO NEAR
KONL/KYKN SATURDAY AFTERNOON. HIGHS SATURDAY SHOULD BE ABLE TO
REACH 100F AS H10-5 THICKNESSES RISE TO NEAR 590 DM. MORE ISOLATED
DIURNALLY DRIVEN HIGH BASED TSTMS ARE EXPECTED TO DEVELOP LATE SATURDAY.
ANOTHER WEAK BACK DOOR COLD FRONT WILL MOVE THROUGH SATURDAY
NIGHT. THIS FRONT WOULD APPEAR TO WASH OUT ACROSS SRN NEB SUNDAY.
BY NOW A HEAT LOW HAS ESTABLISHED ITSELF ACROSS WRN KS/ERN COLO.
THIS LOW COULD STILL PRODUCE TEMPS NEAR 100F AS BOTH THE NAM AND
GEM SHOW H10-5 THICKNESSES APPROACHING 590 DM ACROSS WRN NEB. THE
GENERAL CONSENSUS AMONG THE MODELS WAS FOR ANOTHER UPPER LEVEL
DISTURBANCE TO MOVE THROUGH LATE SUNDAY SUNDAY NIGHT.
MONDAY THROUGH THURSDAY...
THE DROUGHT RIDGE IS FCST BY ALL MODELS TO REMAIN STATIONARY AND
CENTER OVER ERN NM/NW TX. THIS COULD PLACE THE FCST AREA IN THE
RING OF FIRE PROVIDED AMPLE MOISTURE IS AVAILABLE. THE ECM AND GFS
850-300MB MOISTURE SUPPORT THIS BUT FCST QPF IN BOTH MODELS IS
DRY. SO DRY WEATHER IS EXPECTED WITH HIGHS ATLEAST IN THE 90S. H7
TEMPS ARE EXPECTED TO RUN 10C TO 14C WHICH SHOULD PRODUCE UPPER
90S. NOTE THE EXTREME DROUGHT CONDITIONS MAY SUPPORT HIGHS AROUND
100 BUT NOT NEARLY AS WARM AS WE SAW EARLIER THIS MONTH.
&&
.AVIATION...
VFR CONDITIONS ARE EXPECTED AT BOTH KLBF AND KVTN TERMINALS
THROUGH THE 18Z TAF PERIOD. A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS WILL EXIST OVER SOUTHWEST NEBRASKA LATE THIS
AFTERNOON AND EVENING. HOWEVER...GIVEN THE ISOLATED COVERAGE OF
ANY DEVELOPMENT WILL LEAVE ANY MENTION OF TSRA OUT OF THE CURRENT
KLBF TAF. THIS WILL BE MONITORED AND UPDATED IF CONDITIONS
WARRANT. WINDS WILL BE CALM OVERNIGHT BEFORE SWITCHING TO THE
SOUTHEAST TOMORROW MORNING. SKIES WILL BE MOSTLY CLEAR.
&&
.FIRE WEATHER...
ALL THUNDERSTORM ACTIVITY WILL BE CLOSELY MONITORED DURING THE
NEXT 7 DAYS FOR SIGNS OF DRY LIGHTNING AND POTENTIAL WILD FIRES.
STORM COVERAGE IS EXPECTED TO BE LESS THAN 25 PERCENT IN ANY ONE
PARTICULAR FIRE WEATHER ZONE.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/EXTENDED...CDC/TALYOR
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
303 PM CDT THU JUL 26 2012
.DISCUSSION...
SMALL CHANCE FOR PRECIPITATION TONIGHT...THEN THUNDERSTORM CHANCES
FRIDAY NIGHT THROUGH MONDAY...ARE THE PRIMARY FORECAST CONCERNS.
SECONDARY COOL FRONT WAS DROPPING THROUGH THE CWA THIS AFTERNOON.
TEMPERATURES WERE SIMILAR ON BOTH SIDES OF THE BOUNDARY...BUT DEW
POINTS DRIED CONSIDERABLY BEHIND THE FRONT. DEW POINTS WERE IN THE
THE 50S IN NORTHEAST NEBRASKA AS OF 2 PM...WHILE SOUTHEAST NEBRASKA
AND SOUTHWEST IOWA HAD DEW POINTS BETWEEN 65 AND 70. INSTABILITY
WAS INCREASING IN THIS AREA WITH MOST UNSTABLE CAPE VALUES TOPPING
3000 J/KG. LOW LEVEL CONVERGENCE WAS RATHER WEEK AS WINDS ONLY
TURNED FROM WEST TO NORTHWEST AHEAD AND BEHIND FRONT. AND MID
LEVEL LAPSE RATES WERE RATHER TIMID AS WELL. STILL CUMULUS FIELD
WAS BUBBLING UP IN CYCLONIC FLOW IN EAST CENTRAL NEBRASKA AND WEST
CENTRAL IOWA. NAM...GFS AND HRRR ALL SUGGEST SOME CONVECTION WILL
FIRE IN THE UNSTABLE AIR OVER SOUTHEAST NEBRASKA AND SOUTHWEST
IOWA LATE THIS AFTERNOON AND EVENING. GIVEN INSTABILITY AND WEAK
CONVERGENCE ALONG FRONT...PLUS THE FACT THAT RETURNS ARE SHOWING
UP ON RADAR...WILL INSERT ISOLATED STORMS THIS AFTERNOON AND
EVENING IN THOSE AREAS.
STORMS SHOULD MOVE OUT OR DISSIPATE RATHER QUICKLY BY
SUNSET...LEAVING MOSTLY CLEAR SKIES AND DIMINISHING WINDS AS
SURFACE HIGH PRESSURE SETTLES IN OVERNIGHT. THAT HIGH AND A
REDUCTION IN 850 TEMPS BY 5C OR SO WILL LEAD TO COOLER
TEMPERATURES FRIDAY. HAVE HIGHS FROM THE MIDDLE 80S NORTH TO NEAR
90 SOUTH FRIDAY AFTERNOON WITH LIGHT NORTH OR NORTHEAST WINDS.
AS THE HIGH SHIFTS EAST FRIDAY NIGHT...RETURN FLOW BEGINS AS
SHORTWAVE MOVES OFF THE HIGH PLAINS INTO THE REGION. MODELS HAVE
BEEN ADVERTISING THIS THE LAST SEVERAL DAYS...AND ARE NOW CONVERGING
ON A TRACK THROUGH SOUTH DAKOTA AND INTO SOUTHEAST SOUTH DAKOTA BY
12Z SATURDAY. THIS WILL SHIFT AXIS OF ASSOCIATED PRECIPITATION NORTH
OF OUR CURRENT FORECAST...WITH HIGHEST POPS ALONG THE SOUTH DAKOTA
BORDER. WILL MAINTAIN SMALL POPS SOUTHWARD AT LEAST TO INTERSTATE 80
LATE FRIDAY NIGHT AND SATURDAY MORNING WHERE HIGHER THETA-E AIR WILL
RIDE NORTH. AREA SHOULD LIFT TO THE NORTHEAST SATURDAY AFTERNOON AND
WILL MAINTAIN SMALL POPS IN OUR FAR NORTHEAST THEN.
A SIMILAR SITUATION WILL OCCUR SATURDAY NIGHT INTO SUNDAY AS ANOTHER
SHORTWAVE ROLLS THROUGH THE NORTHERN PLAINS. BOTH GFS AND ECMWF SHOW
THIS WAVE A BIT FARTHER NORTH THAN FRIDAY NIGHT WAVE...BUT
MOISTURE...LOW LEVEL JET AND ELEVATED INSTABILITY WILL ALL BE MORE
CONDUCIVE FOR SCATTERED OVERNIGHT CONVECTION. THUS WILL KEEP OUR
SMALL POPS FOR MOST OF THE CWA WITH HIGHEST CHANCES AGAIN IN THE
NORTH AND NORTHEAST.
SURFACE FRONT WILL TRAIL THIS SECOND WAVE AND SETTLE ACROSS THE CWA
SUNDAY NIGHT AND MONDAY. GFS AND ECMWF TRIGGER PRECIPITATION ALONG
THIS BOUNDARY AS YET ANOTHER SHORTWAVE DROPS THROUGH NORTHWEST FLOW
ALOFT...BUT EACH MODEL HAS A SLIGHTLY DIFFERENT TRACK.
WILL KEEP OUR DRY AND WARMER FORECAST GOING THROUGH MID WEEK AS
UPPER RIDGE TRIES TO BUILD BACK INTO THE REGION. MODELS ARE A LITTLE
LESS BULLISH ON BRINGING THIS INTO THE PLAINS...POSSIBLY ALLOWING
MORE SHORTWAVES TO DROP INTO THE REGION BRINGING SPORADIC PRECIP
CHANCES.
DERGAN
&&
.AVIATION...
18Z TAFS FOR KOFK...KOMA AND KLNK.
VFR CONDITIONS EXPECTED THROUGH THE PERIOD WITH HIGH PRESSURE
BUILDING INTO THE REGION. ISOLATED EVENING STORMS COULD AFFECT
KOMA AND KLNK...BUT COVERAGE WILL BE SPARSE.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BUFFALO NY
525 PM EDT THU JUL 26 2012
.SYNOPSIS...
A SOUTHWARD DROPPING FRONTAL BOUNDARY WILL BRING A FEW MORE SHOWERS
AND THUNDERSTORMS TO THE REGION OVERNIGHT. IT WILL REMAIN UNSETTLED
ON FRIDAY AND INTO THE BEGINNING OF THE WEEKEND WITH TEMPERATURES
REMAINING AROUND NORMAL. LATER IN THE WEEKEND DRIER AIR WILL PUSH
INTO THE REGION BRING A RETURN TO SOME SUNSHINE AND WARMER
TEMPERATURES.
&&
.NEAR TERM /THROUGH FRIDAY/...
THIS LATE AFTERNOON SFC LOW PRESSURE WAS LOCATED JUST NORTH OF LAKE
ONTARIO...WITH A WARM FRONT EXTENDING SOUTHEASTWARD TOWARDS EASTERN
NEW YORK...AND A FRONTAL BOUNDARY DRAPED BEHIND THE LOW BACK INTO
THE CENTRAL GREAT LAKES. ON WATER VAPOR IMAGERY A SHORT WAVE WAS
FOUND BACK ACROSS THE NORTHERN PLAINS. REGIONAL RADARS DISPLAYED A
CONVECTIVE LINE OF THUNDERSTORMS NOW PUSHING DEEPER INTO THE
SOUTHERN TIER AND ADVANCING EASTWARD. FARTHER TO THE NORTH A BAND OF
SHOWERS CONTINUES ACROSS THE NORTH COUNTRY NORTH OF THE WARM FRONT.
LATEST SPC MESOSCALE ANALYSIS/RAP DISPLAYS SB CAPES OF 1000 J/KG
OVER THE SOUTHERN TIER. THE RAP DISPLAYS A FINGER OF 1000+ CAPE
NOSING INTO THE WESTERN FINGER LAKES REGION THIS EARLY EVENING AND
THUNDERSTORMS COULD EXPAND NORTHWARD ACROSS THE WESTERN FINGER LAKES
INTO THIS HIGH INSTABILITY. WHILE THE MAIN THREAT OF DAMAGING WINDS
IS ASSOCIATED WITH THE LINE OF THUNDERSTORMS ADVANCING ACROSS THE
SOUTHERN TIER...A STILL 0-6 KM BULK SHEER OF 40 KNOTS COULD BRING A
GUSTY WINDS...PRIMARILY ACROSS THE GENESEE VALLEY.
SHOWERS ACROSS THE NORTH COUNTRY SHOULD GRADUALLY LIFT NORTHWARD AND
DIMINISH THROUGH THE EVENING HOURS. ELSEWHERE AS THE SFC LOW
ADVANCES SOUTH AND EASTWARD A FRONTAL BOUNDARY BEHIND THE LOW WILL
DROP SOUTHWARD ACROSS WNY AND PORTIONS OF CNY. WILL HAVE BRIEF
LIKELY POPS FOR SHOWERS AND EMBEDDED THUNDER ALONG THIS BOUNDARY
THIS EVENING.
AREAS OF FOG WILL BE LIKELY ACROSS THE NORTH COUNTRY THIS EVENING
WHERE TEMPERATURES ARE JUST ABOVE THE DEW POINT. ELSEWHERE AS THE
WINDS VEER TO NORTHWEST BEHIND THE SFC TROUGH EXPECT SOME LOWERING
OF CLOUDS AND VISIBILITIES LATER OVER NIGHT OVER AREAS SOUTH OF LAKE
ONTARIO. THIS MOIST UPSLOPE FLOW WILL MAINTAIN PLENTY OF CLOUDS
SOUTH OF LAKE ONTARIO OVERNIGHT AND KEEP TEMPERATURES ABOVE AVERAGE
WITH OVERNIGHT LOWS IN THE MID TO UPPER 60S.
ON FRIDAY A LIGHT NORTHERLY FLOW WITH AN UPPER LEVEL SHORT WAVE
APPROACHING FROM THE CENTRAL GREAT LAKES WILL MAINTAIN PLENTY OF
CLOUDS TO START THE DAY. SOME DRIZZLE IS POSSIBLE EARLY IN THE
MORNING...BUT THE GREATER CHC FOR MEASURABLE RAINFALL WILL COME
LATER IN THE DAY FRIDAY AS THE UPPER LEVEL SHORT WAVE NEARS THE
REGION.
ACROSS THE NORTH COUNTRY EXPECT SOME CLEARING THROUGH THE DAY. IF
THIS MATERIALIZES THE NORTH COUNTRY WILL LIKELY BE THE WARMEST
TOMORROW WITH HIGHS NEARING THE MID 80S. ELSEWHERE EXPECT JUST MID
70S TO LOWER 80S ACROSS THE CWA SOUTH OF THE NORTH COUNTRY.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AN UPPER LEVEL TROF WILL APPROACH FROM THE UPPER LAKES FRIDAY
NIGHT...WITH THE AXIS FORECAST TO SLOWLY CROSS WESTERN NEW YORK ON
SATURDAY. MODEL GUIDANCE IS IN FAIRLY GOOD AGREEMENT ON THE TIMING
OF THIS FEATURE...BUT QPFS VARY QUITE A BIT...WITH SOME MODELS
(NOTABLY THE 12Z RGEM AND 00Z EUROPEAN) MUCH HEAVIER ON QPF THAN
MOST OTHER GUIDANCE. FEEL THE TROF AND DAYTIME HEATING WILL BE THE
MAIN KEY TO THE DEVELOPMENT OF SHOWERS...BUT THAT ACTIVITY WILL BE
SOMEWHERE BETWEEN THE DRIER AND WETTER MODEL SOLUTIONS. FOR
NOW...LOOKING FOR SCATTERED ACTIVITY...PERHAPS BECOMING NUMEROUS
ACROSS WESTERN PORTIONS OF THE SOUTHERN TIER ON SATURDAY.
AFTER THIS...A BROAD HIGH PRESSURE RIDGE WILL BUILD FROM THE NATIONS
MID-SECTION AND ACROSS WESTERN NEW YORK THROUGH SUNDAY. THIS SHOULD
KEEP SATURDAY NIGHT AND SUNDAY DRY...WITH A FAIR AMOUNT OF CLEAR
SKIES TOO.
WHILE SATURDAY SHOULD NOT BE A COMPLETE WASHOUT WITH HIT OR MISS
SHOWERS...TEMPERATURES STILL SHOULD BE SEASONABLE. WITH SOME BREAKS
OF SUN HIGHS SHOULD RISE INTO THE LOWER 80S. SUNDAY LOOKS TO BE A
QUITE NICE DAY...WITH SLIGHTLY ABOVE NORMAL TEMPERATURES IN THE
LOWER TO MID 80S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE PERIOD WILL START OFF WITH HIGH PRESSURE ACROSS THE REGION FOR
SUNDAY NIGHT AND MONDAY...WITH CONTAINED FAIR WEATHER. AFTER THIS...A
BROAD UPPER TROF WILL SLOWLY APPROACH FROM THE UPPER LAKES...AND
GRADUALLY BUILD ACROSS THE REGION MID-WEEK. THE 12Z GFS/GGEM/00Z
EUROPEAN ALL SHOW THIS PATTERN...SLOWING AND DEEPENING THIS TROF AS
IT MOVES ACROSS NEW ENGLAND. ITS SOURCE DOES NOT APPEAR TO BE
PARTICULARLY MOIST...SO DO NOT EXPECT A SOAKING RAINFALL FROM
THIS...BUT THE SHORTWAVE SHOULD BE AMPLE TO BRING PERIODIC RAIN
SHOWERS AND THUNDERSTORMS. OUTSIDE OF DIURNAL INFLUENCES ITS HARD TO
PINPOINT THE BEST CHANCE FOR SHOWERS...THOUGH THE TROF WILL
GRADUALLY SHIFT FROM WEST TO EAST.
TEMPERATURES LOOK TO BE WARMEST ON MONDAY...WITH THE HIGH IN CONTROL
MORE SUN SHOULD ALLOW FOR TEMPERATURES TO RISE INTO THE LOWER TO MID
80S. AFTER THIS...TEMPERATURES WILL DEPEND ON CLOUD COVER WHICH
SHOULD BE VARIABLE BUT MORE CLOUDS THEN SUN. EXPECT HIGHS TO
GENERALLY BE IN THE LOWER 80S...THOUGH THESE COULD VARY A BIT.
&&
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
THE LINE OF SHOWERS AND THUNDERSTORMS THAT CROSSED THE WESTERN
SOUTHERN TIER THIS AFTERNOON HAVE PUSHED EASTWARD INTO CENTRAL NEW
YORK AT THIS TIME. ISOLATED TO SCATTERED SHOWERS WILL STILL BE
POSSIBLE THROUGH THE EVENING HOURS AS A SURFACE LOW TRACKS ACROSS
THE REGION WITH THE BROADEST COVERAGE FOCUSED EAST OF LAKE
ONTARIO...CLOSEST TO THE LOW CENTER. OTHERWISE EXPECT CONDITIONS
ACROSS THE FORECAST AREA TO DETERIORATE TO IFR LATE THIS EVENING AS
COOL AND MOIST AIR FLOWS ACROSS THE AREA FROM THE NORTH IN THE WAKE
OF THE LOW. THIS MOIST UPSLOPE FLOW SHOULD LEAD TO THE DEVELOPMENT
OF IFR CIGS WITH FOG ALSO POSSIBLE...PARTICULARLY EAST OF LAKE
ONTARIO AND ACROSS THE SOUTHERN TIER WHERE THE HEAVIEST RAIN HAS
FALLEN.
IFR CONDITIONS SHOULD IMPROVE AT LEAST TO MVFR BY MID-MORNING
FRIDAY...HOWEVER SHOWERS WILL ONCE AGAIN BE POSSIBLE FRIDAY
AFTERNOON AS AN UPPER LEVEL TROUGH CROSSES THE REGION.
OUTLOOK...
FRIDAY NIGHT AND SATURDAY...MAINLY VFR WITH CHANCES FOR SHRA.
SUNDAY AND MONDAY...VFR
TUESDAY...MVFR/VFR IN CHC OF SHOWERS.
&&
.MARINE...
HAVE DROPPED THE SCA FOR LAKE ERIE AS WINDS AND WAVES HAVE DROPPED
THIS AFTERNOON. AN AREA OF LOW PRESSURE WILL CONTINUE TO ADVANCE
FROM NEAR LAKE ONTARIO INTO EASTERN NEW YORK OVERNIGHT WITH WINDS
BECOMING LIGHT WHILE VEERING TO NORTHWEST TO NORTH. SOME FOG IS
POSSIBLE OVERNIGHT...THOUGH LIKELY MORE OVER THE LAND MASS.
ON FRIDAY AND SATURDAY EXPECT WINDS AND WAVES TO REMAIN BELOW
SCA...THOUGH UNSETTLED WEATHER WILL CONTINUE.
&&
.CLIMATE...
THE 0.31 INCHES OF RAIN THAT FELL AT THE BUFFALO AIRPORT AFTER
MIDNIGHT...AND BEFORE 7 AM LST THIS MORNING MARKS THE FIRST TIME IN
43 DAYS THAT A TENTH OF AN INCH OF RAINFALL HAS FALLEN AT THE
BUFFALO AIRPORT. THE LAST TENTH OF AN INCH OR GREATER RAINFALL AT
BUFFALO WAS ON JUNE 12TH (0.25"). THIS IS THE SECOND LONGEST
STRETCH OF DAYS ON RECORD IN BUFFALO WITHOUT A TENTH OF AN INCH OF
PRECIPITATION...ONLY EXCEEDED BY A 47 DAY STRETCH BACK IN THE LATE
SUMMER OF 1876.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...THOMAS
NEAR TERM...THOMAS
SHORT TERM...APFFEL
LONG TERM...APFFEL
AVIATION...WOOD
MARINE...APFFEL/THOMAS
CLIMATE...THOMAS
AREA FORECAST DISCUSSION
NWS BUFFALO NY
347 PM EDT THU JUL 26 2012
.SYNOPSIS...
A SOUTHWARD DROPPING FRONTAL BOUNDARY WILL BRING A FEW MORE SHOWERS
AND THUNDERSTORMS TO THE REGION OVERNIGHT. IT WILL REMAIN UNSETTLED
ON FRIDAY AND INTO THE BEGINNING OF THE WEEKEND WITH TEMPERATURES
REMAINING AROUND NORMAL. LATER IN THE WEEKEND DRIER AIR WILL PUSH
INTO THE REGION BRING A RETURN TO SOME SUNSHINE AND WARMER
TEMPERATURES.
&&
.NEAR TERM /THROUGH FRIDAY/...
THIS LATE AFTERNOON SFC LOW PRESSURE WAS LOCATED JUST NORTH OF LAKE
ONTARIO...WITH A WARM FRONT EXTENDING SOUTHEASTWARD TOWARDS EASTERN
NEW YORK...AND A FRONTAL BOUNDARY DRAPED BEHIND THE LOW BACK INTO
THE CENTRAL GREAT LAKES. ON WATER VAPOR IMAGERY A SHORT WAVE WAS
FOUND BACK ACROSS THE NORTHERN PLAINS. REGIONAL RADARS DISPLAYED A
CONVECTIVE LINE OF THUNDERSTORMS NOW PUSHING DEEPER INTO THE
SOUTHERN TIER AND ADVANCING EASTWARD. FARTHER TO THE NORTH A BAND OF
SHOWERS CONTINUES ACROSS THE NORTH COUNTRY NORTH OF THE WARM FRONT.
LATEST SPC MESOSCALE ANALYSIS/RAP DISPLAYS SB CAPES OF 1000 J/KG
OVER THE SOUTHERN TIER. THE RAP DISPLAYS A FINGER OF 1000+ CAPE
NOSING INTO THE WESTERN FINGER LAKES REGION THIS EARLY EVENING AND
THUNDERSTORMS COULD EXPAND NORTHWARD ACROSS THE WESTERN FINGER LAKES
INTO THIS HIGH INSTABILITY. WHILE THE MAIN THREAT OF DAMAGING WINDS
IS ASSOCIATED WITH THE LINE OF THUNDERSTORMS ADVANCING ACROSS THE
SOUTHERN TIER...A STILL 0-6 KM BULK SHEER OF 40 KNOTS COULD BRING A
GUSTY WINDS...PRIMARILY ACROSS THE GENESEE VALLEY.
SHOWERS ACROSS THE NORTH COUNTRY SHOULD GRADUALLY LIFT NORTHWARD AND
DIMINISH THROUGH THE EVENING HOURS. ELSEWHERE AS THE SFC LOW
ADVANCES SOUTH AND EASTWARD A FRONTAL BOUNDARY BEHIND THE LOW WILL
DROP SOUTHWARD ACROSS WNY AND PORTIONS OF CNY. WILL HAVE BRIEF
LIKELY POPS FOR SHOWERS AND EMBEDDED THUNDER ALONG THIS BOUNDARY
THIS EVENING.
AREAS OF FOG WILL BE LIKELY ACROSS THE NORTH COUNTRY THIS EVENING
WHERE TEMPERATURES ARE JUST ABOVE THE DEW POINT. ELSEWHERE AS THE
WINDS VEER TO NORTHWEST BEHIND THE SFC TROUGH EXPECT SOME LOWERING
OF CLOUDS AND VISIBILITIES LATER OVER NIGHT OVER AREAS SOUTH OF LAKE
ONTARIO. THIS MOIST UPSLOPE FLOW WILL MAINTAIN PLENTY OF CLOUDS
SOUTH OF LAKE ONTARIO OVERNIGHT AND KEEP TEMPERATURES ABOVE AVERAGE
WITH OVERNIGHT LOWS IN THE MID TO UPPER 60S.
ON FRIDAY A LIGHT NORTHERLY FLOW WITH AN UPPER LEVEL SHORT WAVE
APPROACHING FROM THE CENTRAL GREAT LAKES WILL MAINTAIN PLENTY OF
CLOUDS TO START THE DAY. SOME DRIZZLE IS POSSIBLE EARLY IN THE
MORNING...BUT THE GREATER CHC FOR MEASURABLE RAINFALL WILL COME
LATER IN THE DAY FRIDAY AS THE UPPER LEVEL SHORT WAVE NEARS THE
REGION.
ACROSS THE NORTH COUNTRY EXPECT SOME CLEARING THROUGH THE DAY. IF
THIS MATERIALIZES THE NORTH COUNTRY WILL LIKELY BE THE WARMEST
TOMORROW WITH HIGHS NEARING THE MID 80S. ELSEWHERE EXPECT JUST MID
70S TO LOWER 80S ACROSS THE CWA SOUTH OF THE NORTH COUNTRY.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AN UPPER LEVEL TROF WILL APPROACH FROM THE UPPER LAKES FRIDAY
NIGHT...WITH THE AXIS FORECAST TO SLOWLY CROSS WESTERN NEW YORK ON
SATURDAY. MODEL GUIDANCE IS IN FAIRLY GOOD AGREEMENT ON THE TIMING
OF THIS FEATURE...BUT QPFS VARY QUITE A BIT...WITH SOME MODELS
(NOTABLY THE 12Z RGEM AND 00Z EUROPEAN) MUCH HEAVIER ON QPF THAN
MOST OTHER GUIDANCE. FEEL THE TROF AND DAYTIME HEATING WILL BE THE
MAIN KEY TO THE DEVELOPMENT OF SHOWERS...BUT THAT ACTIVITY WILL BE
SOMEWHERE BETWEEN THE DRIER AND WETTER MODEL SOLUTIONS. FOR
NOW...LOOKING FOR SCATTERED ACTIVITY...PERHAPS BECOMING NUMEROUS
ACROSS WESTERN PORTIONS OF THE SOUTHERN TIER ON SATURDAY.
AFTER THIS...A BROAD HIGH PRESSURE RIDGE WILL BUILD FROM THE NATIONS
MID-SECTION AND ACROSS WESTERN NEW YORK THROUGH SUNDAY. THIS SHOULD
KEEP SATURDAY NIGHT AND SUNDAY DRY...WITH A FAIR AMOUNT OF CLEAR
SKIES TOO.
WHILE SATURDAY SHOULD NOT BE A COMPLETE WASHOUT WITH HIT OR MISS
SHOWERS...TEMPERATURES STILL SHOULD BE SEASONABLE. WITH SOME BREAKS
OF SUN HIGHS SHOULD RISE INTO THE LOWER 80S. SUNDAY LOOKS TO BE A
QUITE NICE DAY...WITH SLIGHTLY ABOVE NORMAL TEMPERATURES IN THE
LOWER TO MID 80S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE PERIOD WILL START OFF WITH HIGH PRESSURE ACROSS THE REGION FOR
SUNDAY NIGHT AND MONDAY...WITH CONTAINED FAIR WEATHER. AFTER THIS...A
BROAD UPPER TROF WILL SLOWLY APPROACH FROM THE UPPER LAKES...AND
GRADUALLY BUILD ACROSS THE REGION MID-WEEK. THE 12Z GFS/GGEM/00Z
EUROPEAN ALL SHOW THIS PATTERN...SLOWING AND DEEPENING THIS TROF AS
IT MOVES ACROSS NEW ENGLAND. ITS SOURCE DOES NOT APPEAR TO BE
PARTICULARLY MOIST...SO DO NOT EXPECT A SOAKING RAINFALL FROM
THIS...BUT THE SHORTWAVE SHOULD BE AMPLE TO BRING PERIODIC RAIN
SHOWERS AND THUNDERSTORMS. OUTSIDE OF DIURNAL INFLUENCES ITS HARD TO
PINPOINT THE BEST CHANCE FOR SHOWERS...THOUGH THE TROF WILL
GRADUALLY SHIFT FROM WEST TO EAST.
TEMPERATURES LOOK TO BE WARMEST ON MONDAY...WITH THE HIGH IN CONTROL
MORE SUN SHOULD ALLOW FOR TEMPERATURES TO RISE INTO THE LOWER TO MID
80S. AFTER THIS...TEMPERATURES WILL DEPEND ON CLOUD COVER WHICH
SHOULD BE VARIABLE BUT MORE CLOUDS THEN SUN. EXPECT HIGHS TO
GENERALLY BE IN THE LOWER 80S...THOUGH THESE COULD VARY A BIT.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
AT 20Z THE LINE OF THUNDERSTORMS HAVE PRESSED INTO CENTRAL NEW YORK
WITH THE REMAINING PORTION OF THE TAF PERIOD UNDER MINIMAL CHCS FOR
THUNDER. WILL ADD IFR VSBYS TO THE NORTH COUNTRY WHERE TEMPERATURES
NEAR THE DEW POINT WILL FAVOR FOG THROUGH THE EVENING.
TONIGHT...THE COLD FRONT THAT IS TRAILING THE LOW WILL DROP SLOWLY
TO THE SOUTH. A NORTHERLY FLOW OF MOIST AIR BEHIND THE FRONT WILL
LIKELY RESULT IN MORE WIDESPREAD MVFR OR IFR CONDITIONS. WILL LOWER
CIGS TO IFR AT ALL TAF SITES...LINGERING THE LONGEST ACROSS THE
SOUTHERN TIER...AND JUST SOUTH OF LAKE ONTARIO ON THE WEAK UPSLOPE
FLOW FROM LAKE ONTARIO.
THROUGH THE DAY FRIDAY CIGS WILL SLOWLY LIFT BACK TO MVFR/VFR A
STRAY SHOWER IS POSSIBLE LATER IN THE MORNING AND INTO THE EARLY
AFTERNOON HOURS.
OUTLOOK...
FRIDAY NIGHT AND SATURDAY...MAINLY VFR WITH CHANCES FOR SHRA.
SUNDAY AND MONDAY...VFR
TUESDAY...MVFR/VFR IN CHC OF SHOWERS.
&&
.MARINE...
HAVE DROPPED THE SCA FOR LAKE ERIE AS WINDS AND WAVES HAVE DROPPED
THIS AFTERNOON. AN AREA OF LOW PRESSURE WILL CONTINUE TO ADVANCE
FROM NEAR LAKE ONTARIO INTO EASTERN NEW YORK OVERNIGHT WITH WINDS
BECOMING LIGHT WHILE VEERING TO NORTHWEST TO NORTH. SOME FOG IS
POSSIBLE OVERNIGHT...THOUGH LIKELY MORE OVER THE LAND MASS.
ON FRIDAY AND SATURDAY EXPECT WINDS AND WAVES TO REMAIN BELOW
SCA...THOUGH UNSETTLED WEATHER WILL CONTINUE.
&&
.CLIMATE...
THE 0.31 INCHES OF RAIN THAT FELL AT THE BUFFALO AIRPORT AFTER
MIDNIGHT...AND BEFORE 7 AM LST THIS MORNING MARKS THE FIRST TIME IN
43 DAYS THAT A TENTH OF AN INCH OF RAINFALL HAS FALLEN AT THE
BUFFALO AIRPORT. THE LAST TENTH OF AN INCH OR GREATER RAINFALL AT
BUFFALO WAS ON JUNE 12TH (0.25"). THIS IS THE SECOND LONGEST
STRETCH OF DAYS ON RECORD IN BUFFALO WITHOUT A TENTH OF AN INCH OF
PRECIPITATION...ONLY EXCEEDED BY A 47 DAY STRETCH BACK IN THE LATE
SUMMER OF 1876.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...THOMAS
NEAR TERM...THOMAS
SHORT TERM...APFFEL
LONG TERM...APFFEL
AVIATION...THOMAS
MARINE...APFFEL/THOMAS
CLIMATE...THOMAS
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
144 PM EDT THU JUL 26 2012
.SYNOPSIS...
LINGERING SHOWERS WILL REMAIN ACROSS THE AREA INTO EARLY
AFTERNOON...WITH THE POTENTIAL FOR ORGANIZED SEVERE STORMS BY MID
AFTERNOON...ESPECIALLY OVER THE SOUTHERN TIER AND NORTHEAST
PENNSYLVANIA. THE FRONTAL BOUNDARY WILL DRIFT SOUTHWARD ON FRIDAY
INTO SOUTHERN PENNSYLVANIA...BUT THE THREAT OF UNSETTLED WEATHER
WILL PERSIST.
&&
.NEAR TERM /THROUGH TONIGHT/...
11 AM UPDATE...ELONGATED SFC LOPRES EXTENDS FM LK HURON THRU SRN
ONTARIO...WITH WMFNT DRAPED ACRS CWA MAINLY ALONG THE I-81
CORRIDOR. EXTENSIVE CLD CVR STILL EXISTS ACRS NRN HALF OF THE CWA
UP NR THE FINGER LKS INTO THE MOHAWK VLY COURTESY OF MCS WHICH
ROLLED THRU THIS MRNG. THINNING CLDS ARE STARTING TO BREAK UP FM
NEPA INTO THE CNTRL SRN TIER AND EAST INTO THE CATSKILLS AREA.
DEVELOPMENT OF TSTMS THIS AFTN WL BE DEPENDENT ON EROSION OF CLDS.
DWPTS HV RISEN INTO THE U60 ACRS WRN PORTION OF CWA WITH LOW 70S
ACRS WRN PA AND ERN OH IN TREMENDOUS SURGE OF MOISTURE.
CONVECTIVELY INDUCED S/WVS ARE EMBEDDED IN THE FLOW AND WL
INTERACT WITH MOISTURE AND INSTABILITY TO HELP SPARK OFF STORMS IN
THE CENTRAL SRN TIER BTWN 18Z-19Z PER LATEST HRRR REFLECTIVITY
IMAGE. 12Z NAM/RUC SNDGS IN BUFKIT HV LOWERED CAPE VALUES TO
AROUND 1000 J/KG...LIKELY DUE TO THE FACT THAT HEATING HAS BEEN
TEMPERED BY CLD CVR THUS FAR. LATEST SPC DAY1 OUTLOOK HAS SHIFTED
MODERATE RISK SOUTH AND ONLY INCLUDES SNIPPETS OF BROOME CNTY AND
DELAWARE CNTY ALONG WITH ALL OF SULLIVAN CNTY. SOME QUESTIONS
STILL RMN AS TO HOW THUNDERSTORMS WL DVLP IN WAKE OF CLD CVR
FURTHER TO THE NORTH. OVERALL...MAIN SVR WX THREAT FOR DAMAGING
WINDS, LARGE HAIL, AND ISOLD TORNADOES HAS SHIFTED MORE INTO THE
SRN TIER AND NEPA. CONVECTIVE MODE LOOKS TO BE IN THE FORM OF A
MORE LINEAR STRUCTURE WITH EMBEDDED BOWS. ANY DISCRETE CELL THAT
CAN DEVELOP AHD OF THE MAIN LINE WL LKLY ROTATE.
THUS HV KEPT POPS THE SAME WITH LKLY POPS PRETTY MUCH AREA WIDE BY
THIS AFTN. UPDATED SVR WX OUTLOOK, GRAPHICAL HWO AND GRIDS TO
REFLECT CURRENT THINKING.
5 AM UPDATE... AN ACTIVE DAYTIME AND EVENING PD EXPECTED.
SHRA/TSRA CONTINUE TO TRANSLATE ESEWD ACRS THE RGN ATTM...ASSOCD
WITH AN INCOMING WARM FRNT...AND ATTENDANT STG WAA FORCING AND
MOISTURE ADVECTION. STORMS ARE ELEVATED IN NATURE EARLY THIS
MRNG OVER CNY/NE PA...WITH THE BEST INSTAB STILL LOCATED WELL BACK
INTO THE WARM SECTOR...ACRS LK ERIE...LWR MI...AND THE OH VLY. DUE
TO THE ELEVATED NATURE OF THE CONVECTION ATTM...WE FEEL THE NEAR-
TERM SVR THREAT IS LOW...WITH LOCALLY +RA...SMALLER HAIL...AND
GUSTY WINDS TO ARND 40 MPH PERCEIVED TO BE THE MAIN THREATS.
HRRR/WRF SIM REFL PROGS SHOW A PSBL LULL IN THE ACTION LATER THIS
MRNG INTO THE EARLY AFTN...AS THE PRESENT ACTIVITY SLIDES FARTHER
TO THE E AND WEAKENS A BIT. IF THIS LULL DOES OCCUR...THOUGH...IT
SHOULD BE SHORT-LIVED. BY/AFTER 18Z...TSRA SHOULD REINVIGORATE...OWING
TO RAPID DESTABILIZATION AND IMPROVED UPR-LVL JET DYNAMICS. THE
EXACT EVOLUTION REMAINS UNCLEAR LATER TDY INTO THE EARLY
EVE...WITH REGARDS TO EXACTLY WHERE TSRA RE-FIRE...AND WHAT MODE
(LINEAR OR MORE DISCRETE CELLS). DEEP-LYRD SHEAR VECTORS ARE
WRLY...WHICH WOULD BE ORIENTED ORTHOGONAL TO ANY N-S BNDRYS (PRE-
FRNTL TROUGHS...OUTFLOW...OR THE ERN EDGE OF THE SFC WARM
FRNT)...AND THIS COULD FAVOR DISCRETE SUPERCELLS IN THESE
LOCATIONS. UPSTREAM ACTIVITY COMING EWD FROM LWR MI/SRN
ONT...WOULD POINT TO THE PSBLTY OF MORE CLDS/PCPN IN THE NRN HALF
OF THE FA (FINGER LKS/SRN TUG/WRN MOHAWK VLY RGNS). THIS WOULD
POTENTIALLY YIELD MORE STABLE CONDS THESE LOCALES. HOWEVER...JUST
TO THE S OVER NY`S SRN TIER AND NRN PA...THE PROSPECTS FOR MORE
SUNSHINE/BETTER HEATING ARE THERE BEHIND CURRENT ACTIVITY...ALG
WITH SOME DIFF HEATING/LEFTOVER OUTFLOW BNDRYS.
THUS...WE FEEL THE BEST SVR THREAT IS IN THE SRN HALF OF THE
CWA...GENERALLY FROM ABT 18Z...INTO THE 00-03Z TIME RANGES...AND
THIS MATCHES SPC`S OUTLOOK (MDT RISK) PRETTY WELL. INSTAB/SHEAR
COMBO (ML CAPE OF 2000-4000...0-6 KM BULK SHEAR ARND 50 KT...AND
0-1 KM HELICITY OF 100-300) ALL POINT TWDS THE LIKELIHOOD OF A
WELL DEVELOPED SQUALL LN...OR SUPERCELLS (PERHAPS EMBEDDED
TORNADIC ONES).
OBVIOUSLY...WE`LL MONITOR DEVELOPMENTS CLOSELY THROUGHOUT THE DAY
AND INTO THE EVE HRS.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
UNSETTLED WX CONDITIONS EXPECTED TO CONTINUE RIGHT THROUGH EARLY
PORTIONS OF THE WEEKEND AS BROAD CYCLONIC FLOW PERSISTS OVER THE
NORTHEASTERN US. THE NEXT IN A SERIES OF UPPER SHORTWAVES WILL
DIVE SOUTHEAST TOWARDS OUR REGION BY EARLY FRI...WHICH WILL
INTERACT WITH ANOTHER SOUTHWARD MOVING COLD FRONT. AS THIS
OCCURS...EXPECT THE RENEWED DEVELOPMENT OF SHWRS/STORMS BY LATE
MORNING/AFTERNOON ACROSS PORTIONS OF THE AREA AS FRONTAL
CONVERGENCE INTERACTS WITH INCREASING FORCING FROM ALOFT. WITH
RESPECT TO SEVERE POTENTIAL...MUCH LOWER INSTABILITY WILL EXIST AS
TODAY/S MOISTURE WILL BE SCOURED OUT WITH THIS AFTERNOON/S
THUNDERSTORM ACTIVITY. THAT SAID...DESPITE MODERATELY STRONG WIND
FIELDS ALOFT (0-6 KM BULK SHEAR VECTORS ON THE ORDER OF 40
KTS)...SEVERE THREAT APPEARS MARGINAL BASED ON VERY LIMITED
INSTABILITY.
BY SATURDAY...YET ANOTHER SHORTWAVE DIVING INTO THE CENTRAL
APPALACHIANS WILL INTERACT WITH THE LINGERING FRONTAL BOUNDARY
ONCE AGAIN TO PRODUCE CONTINUED CHANCES FOR SHWRS/STORMS. UPPER
WIND FIELDS APPEAR MUCH WEAKER BY SATURDAY AS MAIN MID-LEVEL JET
CORE DIVES WELL SOUTH OF OUR REGION...THIS ORGANIZED SEVERE DOES
NOT APPEAR TO BE IN THE OFFERING. AREAL COVERAGE AS SUGGESTED BY
VARIOUS FCST MODELS TO INCLUDE THE WRF AND GFS SUPPORT MAINTAINING
CHC MENTION FOR POPS ACROSS MUCH OF THE CWA THROUGH THE DAY.
FINALLY BY SATURDAY NIGHT/EARLY SUNDAY...HIGH PRESSURE ACROSS THE
NORTH-CENTRAL GREAT LAKES WILL FINALLY BEGIN MOVING TOWARDS THE
AREA WHICH SHOULD LEAD TO A DECREASE IN SHWR/STORM ACTIVITY.
DESPITE THE PASSAGE OF A COLD FRONT ON FRIDAY...TEMPERATURES WILL
REMAIN NEAR SEASONABLE VALUES THROUGH THE PERIOD.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
UPDATE AS OF 1 PM...IN THE INTEREST OF TIME WITH POTENTIAL SEVERE
WX LOOMING TODAY...ONLY SUBTLE CHANGES WERE MADE TO THE LONG TERM
FORECAST TODAY WHICH WAS HEAVILY INFLUENCED BY HPC DAY 3-7
GUIDANCE.
HIGH PRESSURE PARKED OVER THE REGION DURING THE LATTER HALF OF THE
WEEKEND IS PROGGED TO GIVE WAY TO A BROAD UPPER LEVEL TROF AND
DIFFUSE SURFACE LOW PRESSURE ACROSS CNY AND NEPA BY TUESDAY. NOT MUCH
TO SINK OUR TEETH INTO AS FAR AS A BONAFIDE WEATHER MAKER...BUT
DIURNAL INSTABILITY WITHIN THE CYCLONIC FLOW WILL WARRANT CHANCES
FOR SCATTERED SHOWERS OR THUNDERSTORMS AT ANY TIME AFTER MONDAY.
IF ORGANIZED LOW PRESSURE FORMS ALONG THE EASTERN SEABOARD...THEN
A CHANCE FOR STEADIER RAIN IN SOME AREAS WILL INCREASE FOR
THURSDAY. HOWEVER, MODELS ARE NOT IN GOOD CONSENSUS WITH THAT
SOLUTION AT THIS TIME.
TEMPERATURES LOOK TO BE SEASONABLE FOR LATE JULY AND EARLY AUGUST.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
130 PM UPDATE...
A COLD FRONT WILL APPROACH THE AREA WITH THUNDERSTORMS DEVELOPING
BETWEEN 18Z AND 20Z. KELM AND KITH WILL SEE -TSRA START TO AFFECT
THE TERMINALS AROUND 19Z AND REMAINING SITES WILL SEE -TSRA AFTER
20Z. SEVERE WEATHER WILL BE POSSIBLE FOR TERMINALS SOUTH OF THE
SOUTHERN TIER OF NY INTO NEPA. HAVE INCLUDED TEMPO GROUPS FOR
15G40KTS OUT OF THE WEST-NORTHWEST DIRECTION AS ANY SEVERE STORM
MOVES THROUGH THE TERMINALS.
STORMS WILL EXIT THE TERMINALS BETWEEN 01Z-03Z WITH MVFR
CONDITIONS SETTING IN BEHIND THE STORMS GIVEN MOISTURE PRESENT IN
ITS WAKE...WITH RESTRICTIONS TO VSBYS AND CIGS.
REDEVELOPMENT OF BKN CUMULUS LATE MORNING FRI WITH -SHRAS
POSSIBLE AGAIN BUT TOO EARLY TO INCLUDE MENTION IN TAFS.
OUTLOOK...
FRI NGT-SAT...RESTRICTIONS PSBL IN SHRA/TSRA.
SAT NGT - TUE...MAINLY VFR UNDER BUILDING HIPRES.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MLJ/PVN
NEAR TERM...MLJ/PVN
SHORT TERM...CMG
LONG TERM...JAB
AVIATION...PVN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
141 PM EDT THU JUL 26 2012
.SYNOPSIS...
LINGERING SHOWERS WILL REMAIN ACROSS THE AREA INTO EARLY
AFTERNOON...WITH THE POTENTIAL FOR ORGANIZED SEVERE STORMS BY MID
AFTERNOON...ESPECIALLY OVER THE SOUTHERN TIER AND NORTHEAST
PENNSYLVANIA. THE FRONTAL BOUNDARY WILL DRIFT SOUTHWARD ON FRIDAY
INTO SOUTHERN PENNSYLVANIA...BUT THE THREAT OF UNSETTLED WEATHER
WILL PERSIST.
&&
.NEAR TERM /THROUGH TONIGHT/...
11 AM UPDATE...ELONGATED SFC LOPRES EXTENDS FM LK HURON THRU SRN
ONTARIO...WITH WMFNT DRAPED ACRS CWA MAINLY ALONG THE I-81
CORRIDOR. EXTENSIVE CLD CVR STILL EXISTS ACRS NRN HALF OF THE CWA
UP NR THE FINGER LKS INTO THE MOHAWK VLY COURTESY OF MCS WHICH
ROLLED THRU THIS MRNG. THINNING CLDS ARE STARTING TO BREAK UP FM
NEPA INTO THE CNTRL SRN TIER AND EAST INTO THE CATSKILLS AREA.
DEVELOPMENT OF TSTMS THIS AFTN WL BE DEPENDENT ON EROSION OF CLDS.
DWPTS HV RISEN INTO THE U60 ACRS WRN PORTION OF CWA WITH LOW 70S
ACRS WRN PA AND ERN OH IN TREMENDOUS SURGE OF MOISTURE.
CONVECTIVELY INDUCED S/WVS ARE EMBEDDED IN THE FLOW AND WL
INTERACT WITH MOISTURE AND INSTABILITY TO HELP SPARK OFF STORMS IN
THE CENTRAL SRN TIER BTWN 18Z-19Z PER LATEST HRRR REFLECTIVITY
IMAGE. 12Z NAM/RUC SNDGS IN BUFKIT HV LOWERED CAPE VALUES TO
AROUND 1000 J/KG...LIKELY DUE TO THE FACT THAT HEATING HAS BEEN
TEMPERED BY CLD CVR THUS FAR. LATEST SPC DAY1 OUTLOOK HAS SHIFTED
MODERATE RISK SOUTH AND ONLY INCLUDES SNIPPETS OF BROOME CNTY AND
DELAWARE CNTY ALONG WITH ALL OF SULLIVAN CNTY. SOME QUESTIONS
STILL RMN AS TO HOW THUNDERSTORMS WL DVLP IN WAKE OF CLD CVR
FURTHER TO THE NORTH. OVERALL...MAIN SVR WX THREAT FOR DAMAGING
WINDS, LARGE HAIL, AND ISOLD TORNADOES HAS SHIFTED MORE INTO THE
SRN TIER AND NEPA. CONVECTIVE MODE LOOKS TO BE IN THE FORM OF A
MORE LINEAR STRUCTURE WITH EMBEDDED BOWS. ANY DISCRETE CELL THAT
CAN DEVELOP AHD OF THE MAIN LINE WL LKLY ROTATE.
THUS HV KEPT POPS THE SAME WITH LKLY POPS PRETTY MUCH AREA WIDE BY
THIS AFTN. UPDATED SVR WX OUTLOOK, GRAPHICAL HWO AND GRIDS TO
REFLECT CURRENT THINKING.
5 AM UPDATE... AN ACTIVE DAYTIME AND EVENING PD EXPECTED.
SHRA/TSRA CONTINUE TO TRANSLATE ESEWD ACRS THE RGN ATTM...ASSOCD
WITH AN INCOMING WARM FRNT...AND ATTENDANT STG WAA FORCING AND
MOISTURE ADVECTION. STORMS ARE ELEVATED IN NATURE EARLY THIS
MRNG OVER CNY/NE PA...WITH THE BEST INSTAB STILL LOCATED WELL BACK
INTO THE WARM SECTOR...ACRS LK ERIE...LWR MI...AND THE OH VLY. DUE
TO THE ELEVATED NATURE OF THE CONVECTION ATTM...WE FEEL THE NEAR-
TERM SVR THREAT IS LOW...WITH LOCALLY +RA...SMALLER HAIL...AND
GUSTY WINDS TO ARND 40 MPH PERCEIVED TO BE THE MAIN THREATS.
HRRR/WRF SIM REFL PROGS SHOW A PSBL LULL IN THE ACTION LATER THIS
MRNG INTO THE EARLY AFTN...AS THE PRESENT ACTIVITY SLIDES FARTHER
TO THE E AND WEAKENS A BIT. IF THIS LULL DOES OCCUR...THOUGH...IT
SHOULD BE SHORT-LIVED. BY/AFTER 18Z...TSRA SHOULD REINVIGORATE...OWING
TO RAPID DESTABILIZATION AND IMPROVED UPR-LVL JET DYNAMICS. THE
EXACT EVOLUTION REMAINS UNCLEAR LATER TDY INTO THE EARLY
EVE...WITH REGARDS TO EXACTLY WHERE TSRA RE-FIRE...AND WHAT MODE
(LINEAR OR MORE DISCRETE CELLS). DEEP-LYRD SHEAR VECTORS ARE
WRLY...WHICH WOULD BE ORIENTED ORTHOGONAL TO ANY N-S BNDRYS (PRE-
FRNTL TROUGHS...OUTFLOW...OR THE ERN EDGE OF THE SFC WARM
FRNT)...AND THIS COULD FAVOR DISCRETE SUPERCELLS IN THESE
LOCATIONS. UPSTREAM ACTIVITY COMING EWD FROM LWR MI/SRN
ONT...WOULD POINT TO THE PSBLTY OF MORE CLDS/PCPN IN THE NRN HALF
OF THE FA (FINGER LKS/SRN TUG/WRN MOHAWK VLY RGNS). THIS WOULD
POTENTIALLY YIELD MORE STABLE CONDS THESE LOCALES. HOWEVER...JUST
TO THE S OVER NY`S SRN TIER AND NRN PA...THE PROSPECTS FOR MORE
SUNSHINE/BETTER HEATING ARE THERE BEHIND CURRENT ACTIVITY...ALG
WITH SOME DIFF HEATING/LEFTOVER OUTFLOW BNDRYS.
THUS...WE FEEL THE BEST SVR THREAT IS IN THE SRN HALF OF THE
CWA...GENERALLY FROM ABT 18Z...INTO THE 00-03Z TIME RANGES...AND
THIS MATCHES SPC`S OUTLOOK (MDT RISK) PRETTY WELL. INSTAB/SHEAR
COMBO (ML CAPE OF 2000-4000...0-6 KM BULK SHEAR ARND 50 KT...AND
0-1 KM HELICITY OF 100-300) ALL POINT TWDS THE LIKELIHOOD OF A
WELL DEVELOPED SQUALL LN...OR SUPERCELLS (PERHAPS EMBEDDED
TORNADIC ONES).
OBVIOUSLY...WE`LL MONITOR DEVELOPMENTS CLOSELY THROUGHOUT THE DAY
AND INTO THE EVE HRS.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
UNSETTLED WX CONDITIONS EXPECTED TO CONTINUE RIGHT THROUGH EARLY
PORTIONS OF THE WEEKEND AS BROAD CYCLONIC FLOW PERSISTS OVER THE
NORTHEASTERN US. THE NEXT IN A SERIES OF UPPER SHORTWAVES WILL
DIVE SOUTHEAST TOWARDS OUR REGION BY EARLY FRI...WHICH WILL
INTERACT WITH ANOTHER SOUTHWARD MOVING COLD FRONT. AS THIS
OCCURS...EXPECT THE RENEWED DEVELOPMENT OF SHWRS/STORMS BY LATE
MORNING/AFTERNOON ACROSS PORTIONS OF THE AREA AS FRONTAL
CONVERGENCE INTERACTS WITH INCREASING FORCING FROM ALOFT. WITH
RESPECT TO SEVERE POTENTIAL...MUCH LOWER INSTABILITY WILL EXIST AS
TODAY/S MOISTURE WILL BE SCOURED OUT WITH THIS AFTERNOON/S
THUNDERSTORM ACTIVITY. THAT SAID...DESPITE MODERATELY STRONG WIND
FIELDS ALOFT (0-6 KM BULK SHEAR VECTORS ON THE ORDER OF 40
KTS)...SEVERE THREAT APPEARS MARGINAL BASED ON VERY LIMITED
INSTABILITY.
BY SATURDAY...YET ANOTHER SHORTWAVE DIVING INTO THE CENTRAL
APPALACHIANS WILL INTERACT WITH THE LINGERING FRONTAL BOUNDARY
ONCE AGAIN TO PRODUCE CONTINUED CHANCES FOR SHWRS/STORMS. UPPER
WIND FIELDS APPEAR MUCH WEAKER BY SATURDAY AS MAIN MID-LEVEL JET
CORE DIVES WELL SOUTH OF OUR REGION...THIS ORGANIZED SEVERE DOES
NOT APPEAR TO BE IN THE OFFERING. AREAL COVERAGE AS SUGGESTED BY
VARIOUS FCST MODELS TO INCLUDE THE WRF AND GFS SUPPORT MAINTAINING
CHC MENTION FOR POPS ACROSS MUCH OF THE CWA THROUGH THE DAY.
FINALLY BY SATURDAY NIGHT/EARLY SUNDAY...HIGH PRESSURE ACROSS THE
NORTH-CENTRAL GREAT LAKES WILL FINALLY BEGIN MOVING TOWARDS THE
AREA WHICH SHOULD LEAD TO A DECREASE IN SHWR/STORM ACTIVITY.
DESPITE THE PASSAGE OF A COLD FRONT ON FRIDAY...TEMPERATURES WILL
REMAIN NEAR SEASONABLE VALUES THROUGH THE PERIOD.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
UPDATE AS OF 1 PM...IN THE INTEREST OF TIME WITH POTENTIAL SEVERE
WX LOOMING TODAY...ONLY SUBTLE CHANGES WERE MADE TO THE LONG TERM
FORECAST TODAY WHICH WAS HEAVILY INFLUENCED BY HPC DAY 3-7
GUIDANCE.
HIGH PRESSURE PARKED OVER THE REGION DURING THE LATTER HALF OF THE
WEEKEND IS PROGGED TO GIVE WAY TO A BROAD UPPER LEVEL TROF AND
DIFFUSE SURFACE LOW PRESSURE ACROSS CNY AND NEPA BY TUESDAY. NOT MUCH
TO SINK OUR TEETH INTO AS FAR AS A BONAFIDE WEATHER MAKER...BUT
DIURNAL INSTABILITY WITHIN THE CYCLONIC FLOW WILL WARRANT CHANCES
FOR SCATTERED SHOWERS OR THUNDERSTORMS AT ANY TIME AFTER MONDAY.
IF ORGANIZED LOW PRESSURE FORMS ALONG THE EASTERN SEABOARD...THEN
A CHANCE FOR STEADIER RAIN IN SOME AREAS WILL INCREASE FOR
THURSDAY. HOWEVER, MODELS ARE NOT IN GOOD CONSENSUS WITH THAT
SOLUTION AT THIS TIME.
TEMPERATURES LOOK TO BE SEASONABLE FOR LATE JULY AND EARLY AUGUST.
&&
.AVIATION /17Z THURSDAY THROUGH MONDAY/...
700 AM UPDATE...
A LINE OF THUNDERSTORMS HAS YET TO CLEAR KAVP. HERE...BRIEF MVFR
OR IFR VSBYS POSSIBLE THROUGH 13Z IN HEAVY RAIN. OTHERWISE SHOWERS
THROUGH 15Z MAY PRODUCE VERY BRIEF MVFR VSBYS BUT FOR THE MOST
PART AN OVC MID DECK AROUND 5KFT WITH VSBYS ABOVE 6SM EXPECTED.
AFTER SEEING A BREAK IN THE RAIN LATE THIS MORNING...A COLD FRONT
WILL APPROACH THE AREA WITH THUNDERSTORMS RE-DEVELOPING AFTER 18Z.
THESE STORMS COULD BECOME SEVERE WITH HIGH WINDS AND LARGE HAIL
POSSIBLE. BEST THREAT FOR THUNDERSTORMS WILL BE AFTER 18Z...WITH
THE HIGHEST SEVERE THREAT BETWEEN 19Z AND 23Z NORTHERN AND WESTERN
TERMINALS (KITH/KELM/KSYR/KRME)...20Z TO 24Z KBGM...AND 22Z TO 02Z
KAVP. GIVEN AN ENHANCED THREAT FOR SEVERE WEATHER...INCLUDED MVFR
VSBYS AND CIGS ALONG WITH GUSTY WINDS IN A TEMPO GROUP FOLLOWING
THE TIMING SHOWN ABOVE. BEYOND THE TEMPO PERIOD...SHOWERS AND EVEN
SOME THUNDER MAY LINGER INTO EARLY TONIGHT BUT TOO FAR OUT AND
CONFIDENCE NOT HIGH ENOUGH ON EXACT TIMING TO INCLUDE
RESTRICTIONS....THUS ONLY INCLUDED -SHRA AT THE MOMENT.
LIGHT AND VARIABLE WINDS EARLY THIS MORNING BECOME SOUTHWEST TODAY
AT AROUND 10 KTS WITH GUSTS TO 25 KTS. WINDS DIMINISH EARLY
TONIGHT AND VEER TOWARD THE WEST AND EVENTUALLY NORTHWEST.
OUTLOOK...
THUR TO FRI NGT...RESTRICTIONS PSBL IN SHRA/TSRA.
SAT/MON...MAINLY VFR UNDER BUILDING HIPRES.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MLJ/PVN
NEAR TERM...MLJ/PVN
SHORT TERM...CMG
LONG TERM...JAB
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
139 PM EDT THU JUL 26 2012
.SYNOPSIS...
LINGERING SHOWERS WILL REMAIN ACROSS THE AREA INTO EARLY
AFTERNOON...WITH THE POTENTIAL FOR ORGANIZED SEVERE STORMS BY MID
AFTERNOON...ESPECIALLY OVER THE SOUTHERN TIER AND NORTHEAST
PENNSYLVANIA. THE FRONTAL BOUNDARY WILL DRIFT SOUTHWARD ON FRIDAY
INTO SOUTHERN PENNSYLVANIA...BUT THE THREAT OF UNSETTLED WEATHER
WILL PERSIST.
&&
.NEAR TERM /THROUGH TONIGHT/...
11 AM UPDATE...ELONGATED SFC LOPRES EXTENDS FM LK HURON THRU SRN
ONTARIO...WITH WMFNT DRAPED ACRS CWA MAINLY ALONG THE I-81
CORRIDOR. EXTENSIVE CLD CVR STILL EXISTS ACRS NRN HALF OF THE CWA
UP NR THE FINGER LKS INTO THE MOHAWK VLY COURTESY OF MCS WHICH
ROLLED THRU THIS MRNG. THINNING CLDS ARE STARTING TO BREAK UP FM
NEPA INTO THE CNTRL SRN TIER AND EAST INTO THE CATSKILLS AREA.
DEVELOPMENT OF TSTMS THIS AFTN WL BE DEPENDENT ON EROSION OF CLDS.
DWPTS HV RISEN INTO THE U60 ACRS WRN PORTION OF CWA WITH LOW 70S
ACRS WRN PA AND ERN OH IN TREMENDOUS SURGE OF MOISTURE.
CONVECTIVELY INDUCED S/WVS ARE EMBEDDED IN THE FLOW AND WL
INTERACT WITH MOISTURE AND INSTABILITY TO HELP SPARK OFF STORMS IN
THE CENTRAL SRN TIER BTWN 18Z-19Z PER LATEST HRRR REFLECTIVITY
IMAGE. 12Z NAM/RUC SNDGS IN BUFKIT HV LOWERED CAPE VALUES TO
AROUND 1000 J/KG...LIKELY DUE TO THE FACT THAT HEATING HAS BEEN
TEMPERED BY CLD CVR THUS FAR. LATEST SPC DAY1 OUTLOOK HAS SHIFTED
MODERATE RISK SOUTH AND ONLY INCLUDES SNIPPETS OF BROOME CNTY AND
DELAWARE CNTY ALONG WITH ALL OF SULLIVAN CNTY. SOME QUESTIONS
STILL RMN AS TO HOW THUNDERSTORMS WL DVLP IN WAKE OF CLD CVR
FURTHER TO THE NORTH. OVERALL...MAIN SVR WX THREAT FOR DAMAGING
WINDS, LARGE HAIL, AND ISOLD TORNADOES HAS SHIFTED MORE INTO THE
SRN TIER AND NEPA. CONVECTIVE MODE LOOKS TO BE IN THE FORM OF A
MORE LINEAR STRUCTURE WITH EMBEDDED BOWS. ANY DISCRETE CELL THAT
CAN DEVELOP AHD OF THE MAIN LINE WL LKLY ROTATE.
THUS HV KEPT POPS THE SAME WITH LKLY POPS PRETTY MUCH AREA WIDE BY
THIS AFTN. UPDATED SVR WX OUTLOOK, GRAPHICAL HWO AND GRIDS TO
REFLECT CURRENT THINKING.
5 AM UPDATE... AN ACTIVE DAYTIME AND EVENING PD EXPECTED.
SHRA/TSRA CONTINUE TO TRANSLATE ESEWD ACRS THE RGN ATTM...ASSOCD
WITH AN INCOMING WARM FRNT...AND ATTENDANT STG WAA FORCING AND
MOISTURE ADVECTION. STORMS ARE ELEVATED IN NATURE EARLY THIS
MRNG OVER CNY/NE PA...WITH THE BEST INSTAB STILL LOCATED WELL BACK
INTO THE WARM SECTOR...ACRS LK ERIE...LWR MI...AND THE OH VLY. DUE
TO THE ELEVATED NATURE OF THE CONVECTION ATTM...WE FEEL THE NEAR-
TERM SVR THREAT IS LOW...WITH LOCALLY +RA...SMALLER HAIL...AND
GUSTY WINDS TO ARND 40 MPH PERCEIVED TO BE THE MAIN THREATS.
HRRR/WRF SIM REFL PROGS SHOW A PSBL LULL IN THE ACTION LATER THIS
MRNG INTO THE EARLY AFTN...AS THE PRESENT ACTIVITY SLIDES FARTHER
TO THE E AND WEAKENS A BIT. IF THIS LULL DOES OCCUR...THOUGH...IT
SHOULD BE SHORT-LIVED. BY/AFTER 18Z...TSRA SHOULD REINVIGORATE...OWING
TO RAPID DESTABILIZATION AND IMPROVED UPR-LVL JET DYNAMICS. THE
EXACT EVOLUTION REMAINS UNCLEAR LATER TDY INTO THE EARLY
EVE...WITH REGARDS TO EXACTLY WHERE TSRA RE-FIRE...AND WHAT MODE
(LINEAR OR MORE DISCRETE CELLS). DEEP-LYRD SHEAR VECTORS ARE
WRLY...WHICH WOULD BE ORIENTED ORTHOGONAL TO ANY N-S BNDRYS (PRE-
FRNTL TROUGHS...OUTFLOW...OR THE ERN EDGE OF THE SFC WARM
FRNT)...AND THIS COULD FAVOR DISCRETE SUPERCELLS IN THESE
LOCATIONS. UPSTREAM ACTIVITY COMING EWD FROM LWR MI/SRN
ONT...WOULD POINT TO THE PSBLTY OF MORE CLDS/PCPN IN THE NRN HALF
OF THE FA (FINGER LKS/SRN TUG/WRN MOHAWK VLY RGNS). THIS WOULD
POTENTIALLY YIELD MORE STABLE CONDS THESE LOCALES. HOWEVER...JUST
TO THE S OVER NY`S SRN TIER AND NRN PA...THE PROSPECTS FOR MORE
SUNSHINE/BETTER HEATING ARE THERE BEHIND CURRENT ACTIVITY...ALG
WITH SOME DIFF HEATING/LEFTOVER OUTFLOW BNDRYS.
THUS...WE FEEL THE BEST SVR THREAT IS IN THE SRN HALF OF THE
CWA...GENERALLY FROM ABT 18Z...INTO THE 00-03Z TIME RANGES...AND
THIS MATCHES SPC`S OUTLOOK (MDT RISK) PRETTY WELL. INSTAB/SHEAR
COMBO (ML CAPE OF 2000-4000...0-6 KM BULK SHEAR ARND 50 KT...AND
0-1 KM HELICITY OF 100-300) ALL POINT TWDS THE LIKELIHOOD OF A
WELL DEVELOPED SQUALL LN...OR SUPERCELLS (PERHAPS EMBEDDED
TORNADIC ONES).
OBVIOUSLY...WE`LL MONITOR DEVELOPMENTS CLOSELY THROUGHOUT THE DAY
AND INTO THE EVE HRS.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
530 AM UPDATE... WILL MAKE THIS SHORT...DUE TO NEAR-TERM WX
CONCERNS.
LTR TNT AND FRI...NWP CONSENSUS BRINGS A SFC COLD FRNT SWD THROUGH
THE CWA...AND DOWN TWDS THE MASON-DIXON LN. EVEN ONCE THE FRNT
PUSHES TO OUR S...UNSETTLED CONDS SHOULD PERSIST...WITH UPPER-LVL
WAVES STILL COMING ACRS FM W TO E. WE`LL USE CHC/SCTD POPS RIGHT
THROUGH SAT. THE BEST PROSPECTS FOR PCPN MAY COME FRI NGT AND
EARLY SAT...WITH THE MOST AMPLIFIED TROUGH APPROACHING IN THIS
TIME FRAME.
BY SAT NGT...AS THE BEST FORCING EXITS THE E COAST...DEEPER MOIST
AND MORE ORGANIZED PCPN SHOULD SLIDE FARTHER S AND E...WITH POPS
LWRG OVER TIME.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
UPDATE AS OF 1 PM...IN THE INTEREST OF TIME WITH POTENTIAL SEVERE
WX LOOMING TODAY...ONLY SUBTLE CHANGES WERE MADE TO THE LONG TERM
FORECAST TODAY WHICH WAS HEAVILY INFLUENCED BY HPC DAY 3-7
GUIDANCE.
HIGH PRESSURE PARKED OVER THE REGION DURING THE LATTER HALF OF THE
WEEKEND IS PROGGED TO GIVE WAY TO A BROAD UPPER LEVEL TROF AND
DIFFUSE SURFACE LOW PRESSURE ACROSS CNY AND NEPA BY TUESDAY. NOT MUCH
TO SINK OUR TEETH INTO AS FAR AS A BONAFIDE WEATHER MAKER...BUT
DIURNAL INSTABILITY WITHIN THE CYCLONIC FLOW WILL WARRANT CHANCES
FOR SCATTERED SHOWERS OR THUNDERSTORMS AT ANY TIME AFTER MONDAY.
IF ORGANIZED LOW PRESSURE FORMS ALONG THE EASTERN SEABOARD...THEN
A CHANCE FOR STEADIER RAIN IN SOME AREAS WILL INCREASE FOR
THURSDAY. HOWEVER, MODELS ARE NOT IN GOOD CONSENSUS WITH THAT
SOLUTION AT THIS TIME.
TEMPERATURES LOOK TO BE SEASONABLE FOR LATE JULY AND EARLY AUGUST.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
130 PM UPDATE...
A COLD FRONT WILL APPROACH THE AREA WITH THUNDERSTORMS DEVELOPING
BETWEEN 18Z AND 20Z. KELM AND KITH WILL SEE -TSRA START TO AFFECT
THE TERMINALS AROUND 19Z AND REMAINING SITES WILL SEE -TSRA AFTER
20Z. SEVERE WEATHER WILL BE POSSIBLE FOR TERMINALS SOUTH OF THE
SOUTHERN TIER OF NY INTO NEPA. HAVE INCLUDED TEMPO GROUPS FOR
15G40KTS OUT OF THE WEST-NORTHWEST DIRECTION AS ANY SEVERE STORM
MOVES THROUGH THE TERMINALS.
STORMS WILL EXIT THE TERMINALS BETWEEN 01Z-03Z WITH MVFR
CONDITIONS SETTING IN BEHIND THE STORMS GIVEN MOISTURE PRESENT IN
ITS WAKE...WITH RESTRICTIONS TO VSBYS AND CIGS.
REDEVELOPMENT OF BKN CUMULUS LATE MORNING FRI WITH -SHRAS
POSSIBLE AGAIN BUT TOO EARLY TO INCLUDE MENTION IN TAFS.
OUTLOOK...
FRI NGT-SAT...RESTRICTIONS PSBL IN SHRA/TSRA.
SAT NGT - TUE...MAINLY VFR UNDER BUILDING HIPRES.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MLJ/PVN
NEAR TERM...MLJ/PVN
SHORT TERM...CMG
LONG TERM...JAB
AVIATION...PVN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
100 PM EDT THU JUL 26 2012
.SYNOPSIS...
LINGERING SHOWERS WILL REMAIN ACROSS THE AREA INTO EARLY
AFTERNOON...WITH THE POTENTIAL FOR ORGANIZED SEVERE STORMS BY MID
AFTERNOON...ESPECIALLY OVER THE SOUTHERN TIER AND NORTHEAST
PENNSYLVANIA. THE FRONTAL BOUNDARY WILL DRIFT SOUTHWARD ON FRIDAY
INTO SOUTHERN PENNSYLVANIA...BUT THE THREAT OF UNSETTLED WEATHER
WILL PERSIST.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
11 AM UPDATE...ELONGATED SFC LOPRES EXTENDS FM LK HURON THRU SRN
ONTARIO...WITH WMFNT DRAPED ACRS CWA MAINLY ALONG THE I-81
CORRIDOR. EXTENSIVE CLD CVR STILL EXISTS ACRS NRN HALF OF THE CWA
UP NR THE FINGER LKS INTO THE MOHAWK VLY COURTESY OF MCS WHICH
ROLLED THRU THIS MRNG. THINNING CLDS ARE STARTING TO BREAK UP FM
NEPA INTO THE CNTRL SRN TIER AND EAST INTO THE CATSKILLS AREA.
DEVELOPMENT OF TSTMS THIS AFTN WL BE DEPENDENT ON EROSION OF CLDS.
DWPTS HV RISEN INTO THE U60 ACRS WRN PORTION OF CWA WITH LOW 70S
ACRS WRN PA AND ERN OH IN TREMENDOUS SURGE OF MOISTURE.
CONVECTIVELY INDUCED S/WVS ARE EMBEDDED IN THE FLOW AND WL
INTERACT WITH MOISTURE AND INSTABILITY TO HELP SPARK OFF STORMS IN
THE CENTRAL SRN TIER BTWN 18Z-19Z PER LATEST HRRR REFLECTIVITY
IMAGE. 12Z NAM/RUC SNDGS IN BUFKIT HV LOWERED CAPE VALUES TO
AROUND 1000 J/KG...LIKELY DUE TO THE FACT THAT HEATING HAS BEEN
TEMPERED BY CLD CVR THUS FAR. LATEST SPC DAY1 OUTLOOK HAS SHIFTED
MODERATE RISK SOUTH AND ONLY INCLUDES SNIPPETS OF BROOME CNTY AND
DELAWARE CNTY ALONG WITH ALL OF SULLIVAN CNTY. SOME QUESTIONS
STILL RMN AS TO HOW THUNDERSTORMS WL DVLP IN WAKE OF CLD CVR
FURTHER TO THE NORTH. OVERALL...MAIN SVR WX THREAT FOR DAMAGING
WINDS, LARGE HAIL, AND ISOLD TORNADOES HAS SHIFTED MORE INTO THE
SRN TIER AND NEPA. CONVECTIVE MODE LOOKS TO BE IN THE FORM OF A
MORE LINEAR STRUCTURE WITH EMBEDDED BOWS. ANY DISCRETE CELL THAT
CAN DEVELOP AHD OF THE MAIN LINE WL LKLY ROTATE.
THUS HV KEPT POPS THE SAME WITH LKLY POPS PRETTY MUCH AREA WIDE BY
THIS AFTN. UPDATED SVR WX OUTLOOK, GRAPHICAL HWO AND GRIDS TO
REFLECT CURRENT THINKING.
5 AM UPDATE... AN ACTIVE DAYTIME AND EVENING PD EXPECTED.
SHRA/TSRA CONTINUE TO TRANSLATE ESEWD ACRS THE RGN ATTM...ASSOCD
WITH AN INCOMING WARM FRNT...AND ATTENDANT STG WAA FORCING AND
MOISTURE ADVECTION. STORMS ARE ELEVATED IN NATURE EARLY THIS
MRNG OVER CNY/NE PA...WITH THE BEST INSTAB STILL LOCATED WELL BACK
INTO THE WARM SECTOR...ACRS LK ERIE...LWR MI...AND THE OH VLY. DUE
TO THE ELEVATED NATURE OF THE CONVECTION ATTM...WE FEEL THE NEAR-
TERM SVR THREAT IS LOW...WITH LOCALLY +RA...SMALLER HAIL...AND
GUSTY WINDS TO ARND 40 MPH PERCEIVED TO BE THE MAIN THREATS.
HRRR/WRF SIM REFL PROGS SHOW A PSBL LULL IN THE ACTION LATER THIS
MRNG INTO THE EARLY AFTN...AS THE PRESENT ACTIVITY SLIDES FARTHER
TO THE E AND WEAKENS A BIT. IF THIS LULL DOES OCCUR...THOUGH...IT
SHOULD BE SHORT-LIVED. BY/AFTER 18Z...TSRA SHOULD REINVIGORATE...OWING
TO RAPID DESTABILIZATION AND IMPROVED UPR-LVL JET DYNAMICS. THE
EXACT EVOLUTION REMAINS UNCLEAR LATER TDY INTO THE EARLY
EVE...WITH REGARDS TO EXACTLY WHERE TSRA RE-FIRE...AND WHAT MODE
(LINEAR OR MORE DISCRETE CELLS). DEEP-LYRD SHEAR VECTORS ARE
WRLY...WHICH WOULD BE ORIENTED ORTHOGONAL TO ANY N-S BNDRYS (PRE-
FRNTL TROUGHS...OUTFLOW...OR THE ERN EDGE OF THE SFC WARM
FRNT)...AND THIS COULD FAVOR DISCRETE SUPERCELLS IN THESE
LOCATIONS. UPSTREAM ACTIVITY COMING EWD FROM LWR MI/SRN
ONT...WOULD POINT TO THE PSBLTY OF MORE CLDS/PCPN IN THE NRN HALF
OF THE FA (FINGER LKS/SRN TUG/WRN MOHAWK VLY RGNS). THIS WOULD
POTENTIALLY YIELD MORE STABLE CONDS THESE LOCALES. HOWEVER...JUST
TO THE S OVER NY`S SRN TIER AND NRN PA...THE PROSPECTS FOR MORE
SUNSHINE/BETTER HEATING ARE THERE BEHIND CURRENT ACTIVITY...ALG
WITH SOME DIFF HEATING/LEFTOVER OUTFLOW BNDRYS.
THUS...WE FEEL THE BEST SVR THREAT IS IN THE SRN HALF OF THE
CWA...GENERALLY FROM ABT 18Z...INTO THE 00-03Z TIME RANGES...AND
THIS MATCHES SPC`S OUTLOOK (MDT RISK) PRETTY WELL. INSTAB/SHEAR
COMBO (ML CAPE OF 2000-4000...0-6 KM BULK SHEAR ARND 50 KT...AND
0-1 KM HELICITY OF 100-300) ALL POINT TWDS THE LIKELIHOOD OF A
WELL DEVELOPED SQUALL LN...OR SUPERCELLS (PERHAPS EMBEDDED
TORNADIC ONES).
OBVIOUSLY...WE`LL MONITOR DEVELOPMENTS CLOSELY THROUGHOUT THE DAY
AND INTO THE EVE HRS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
530 AM UPDATE... WILL MAKE THIS SHORT...DUE TO NEAR-TERM WX
CONCERNS.
LTR TNT AND FRI...NWP CONSENSUS BRINGS A SFC COLD FRNT SWD THROUGH
THE CWA...AND DOWN TWDS THE MASON-DIXON LN. EVEN ONCE THE FRNT
PUSHES TO OUR S...UNSETTLED CONDS SHOULD PERSIST...WITH UPPER-LVL
WAVES STILL COMING ACRS FM W TO E. WE`LL USE CHC/SCTD POPS RIGHT
THROUGH SAT. THE BEST PROSPECTS FOR PCPN MAY COME FRI NGT AND
EARLY SAT...WITH THE MOST AMPLIFIED TROUGH APPROACHING IN THIS
TIME FRAME.
BY SAT NGT...AS THE BEST FORCING EXITS THE E COAST...DEEPER MOIST
AND MORE ORGANIZED PCPN SHOULD SLIDE FARTHER S AND E...WITH POPS
LWRG OVER TIME.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
UPDATE AS OF 1 PM...IN THE INTEREST OF TIME WITH POTENTIAL SEVERE
WX LOOMING TODAY...ONLY SUBTLE CHANGES WERE MADE TO THE LONG TERM
FORECAST TODAY WHICH WAS HEAVILY INFLUENCED BY HPC DAY 3-7
GUIDANCE.
HIGH PRESSURE PARKED OVER THE REGION DURING THE LATTER HALF OF THE
WEEKEND IS PROGGED TO GIVE WAY TO A BROAD UPPER LEVEL TROF AND
DIFFUSE SURFACE LOW PRESSURE ACROSS CNY AND NEPA BY TUESDAY. NOT MUCH
TO SINK OUR TEETH INTO AS FAR AS A BONAFIDE WEATHER MAKER...BUT
DIURNAL INSTABILITY WITHIN THE CYCLONIC FLOW WILL WARRANT CHANCES
FOR SCATTERED SHOWERS OR THUNDERSTORMS AT ANY TIME AFTER MONDAY.
IF ORGANIZED LOW PRESSURE FORMS ALONG THE EASTERN SEABOARD...THEN
A CHANCE FOR STEADIER RAIN IN SOME AREAS WILL INCREASE FOR
THURSDAY. HOWEVER, MODELS ARE NOT IN GOOD CONSENSUS WITH THAT
SOLUTION AT THIS TIME.
TEMPERATURES LOOK TO BE SEASONABLE FOR LATE JULY AND EARLY AUGUST.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
700 AM UPDATE...
A LINE OF THUNDERSTORMS HAS YET TO CLEAR KAVP. HERE...BRIEF MVFR
OR IFR VSBYS POSSIBLE THROUGH 13Z IN HEAVY RAIN. OTHERWISE SHOWERS
THROUGH 15Z MAY PRODUCE VERY BRIEF MVFR VSBYS BUT FOR THE MOST
PART AN OVC MID DECK AROUND 5KFT WITH VSBYS ABOVE 6SM EXPECTED.
AFTER SEEING A BREAK IN THE RAIN LATE THIS MORNING...A COLD FRONT
WILL APPROACH THE AREA WITH THUNDERSTORMS RE-DEVELOPING AFTER 18Z.
THESE STORMS COULD BECOME SEVERE WITH HIGH WINDS AND LARGE HAIL
POSSIBLE. BEST THREAT FOR THUNDERSTORMS WILL BE AFTER 18Z...WITH
THE HIGHEST SEVERE THREAT BETWEEN 19Z AND 23Z NORTHERN AND WESTERN
TERMINALS (KITH/KELM/KSYR/KRME)...20Z TO 24Z KBGM...AND 22Z TO 02Z
KAVP. GIVEN AN ENHANCED THREAT FOR SEVERE WEATHER...INCLUDED MVFR
VSBYS AND CIGS ALONG WITH GUSTY WINDS IN A TEMPO GROUP FOLLOWING
THE TIMING SHOWN ABOVE. BEYOND THE TEMPO PERIOD...SHOWERS AND EVEN
SOME THUNDER MAY LINGER INTO EARLY TONIGHT BUT TOO FAR OUT AND
CONFIDENCE NOT HIGH ENOUGH ON EXACT TIMING TO INCLUDE
RESTRICTIONS....THUS ONLY INCLUDED -SHRA AT THE MOMENT.
LIGHT AND VARIABLE WINDS EARLY THIS MORNING BECOME SOUTHWEST TODAY
AT AROUND 10 KTS WITH GUSTS TO 25 KTS. WINDS DIMINISH EARLY
TONIGHT AND VEER TOWARD THE WEST AND EVENTUALLY NORTHWEST.
OUTLOOK...
THUR TO FRI NGT...RESTRICTIONS PSBL IN SHRA/TSRA.
SAT/MON...MAINLY VFR UNDER BUILDING HIPRES.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MLJ/PVN
NEAR TERM...MLJ/PVN
SHORT TERM...MLJ
LONG TERM...JAB
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
335 PM EDT THU JUL 26 2012
.SYNOPSIS...
A COLD FRONT WILL CROSS SOUTHEAST THROUGH THE OHIO VALLEY THIS
EVENING. A TRAILING LOW PRESSURE SYSTEM WILL CROSS OUR AREA ON
FRIDAY...BRINGING ADDITIONAL SHOWERS AND THUNDERSTORMS TO THE
REGION. BEHIND THIS LOW...HIGH PRESSURE WILL THEN BRING MORE
SEASONABLE TEMPERATURES AND DRIER CONDITIONS FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL MIDNIGHT TONIGHT/...
ASIDE FROM DROPPING HEAT ADVISORY OVER MUCH OF THE NORTHWEST CWA
AS TEMPERATURES WILL NOT BE ABLE TO RECOVER FROM THE CLOUD COVER
AND OUTFLOW...PREVIOUS DISCUSSION FOR THIS EVENINGS WEATHER IS
UNCHANGED AND STILL VALID AND NOTED BELOW.
SYNOPTICALLY SPEAKING...THE GREAT LAKES AND OHIO VALLEY WILL
REMAIN UNDER A SOUTHWEST TO WEST FLOW ALOFT TODAY INTO TONIGHT. A
COLD FRONT IS FORECAST TO DROP SOUTHEAST INTO THE REGION LATE IN
THE DAY AND MAY HANG UP ACRS THE NRN AREAS OVERNIGHT. LOOKING AT
SATELLITE IMAGERY...IT SHOULD BE NOTED THAT THERE ARE SEVERAL
EMBEDDED DISTURBANCES IN THE SOUTHWEST TO WEST FLOW ALOFT
EXTENDING FROM MISSOURI NORTHEAST INTO THE WESTERN GREAT LAKES.
TWO FEATURES FROM ERN MISSOURI INTO WESTERN ILLINOIS MAY BE THE
IMPETUS TO GET A QLCS GOING ACRS CENTRAL/SOUTH CENTRAL INDIANA
EARLY THIS AFTN. SFC OBSERVATIONS ALSO INDICATE THAT THERE IS A
PREFRONTAL TROF IN THIS REGION AS WELL. IF THIS GETS GOING AS THE
LATEST HRRR INDICATES...IT SHOULD INTENSIFY AS IT MOVES
EAST/SOUTHEAST ACRS OUR REGION DURING THE AFTERNOON AND EVENING
HOURS AS IT FEEDS INTO A VERY UNSTABLE AIRMASS OF 2500-3500 J/KG
OF MLCAPE. IT ALSO WILL HAVE THE ORGANIZATION AND MOMENTUM TO MOVE
QUICKLY AS BULK SHEAR BETWEEN 0=6 KM ARE AROUND 40 KNOTS. GIVEN
THAT FLOW WILL BE MAINLY UNIDIRECTIONAL...FEEL TORNADO THREAT WILL
BE MINIMAL WHILE DAMAGING WINDS AND HAIL SHOULD BE THE MAIN
THREATS. IN FACT...IT IS THE DAMAGING WIND POTENTIAL THAT WILL
LIKELY BE THE HIGHEST IMPACT DUE TO 50 KNOT MID LEVEL JET MOVING
ACRS THE REGION...STEEP LOW LEVEL LAPSE RATES...DELTA THREAT E
VALUES OF 25 KELVIN AND DCAPES OF 1000-1500 J/KG. ALTHOUGH TREE
DAMAGE AND POWER OUTAGES MAY OCCUR...ATTM...WE EXPECT THIS FEATURE
TO BEHAVE MORE LIKE A QLCS/BOW ECHO FEATURE AND NOT MIMIC THE JUNE
29 DERECHO THAT CAUSED EXTENSIVE/WIDESPREAD DAMAGE OVER MOST OF
THE ENTIRE REGION. THAT SAID...THERE WILL BE WIND DAMAGE AND OF
COURSE THERE COULD BE POCKETS OF ENHANCED WIND DAMAGE WITH ANY
OUTFLOW/GUST FRONT OR MICROBURST. THUS...THE SPC HAS KEPT MOST OF
OUR AREA IN A MODERATE RISK FOR SEVERE THUNDERSTORMS. PWATS WILL BE
HIGH...IN EXCESS OF 2 INCHES...WITH THE THUNDERSTORM ACTIVITY SO
LOCALLY HEAVY RAIN AND LOCALIZED FLOODING WILL BE POSSIBLE BUT
SHOULD BE LIMITED GIVEN THE SPEED AT WHICH STORMS WILL BE MOVING.
A HOT AND HUMID AIRMASS WILL BE IN PLACE FOR THESE THUNDERSTORMS
TO FEED ON. GIVEN THE AMOUNT OF SUNSHINE OCCURRING OVER THE ERN/SRN
AREAS THIS MORNING...AND THE FACT THAT KILN SOUNDING AND MODEL
SOUNDINGS INDICATE THAT 850 MB TEMPS WILL BE IN THE 23-24 C
RANGE...BELIEVE A GOOD CHUNK OF THIS REGION WILL SEE TEMPERATURES
PEAK INTO THE MID AND UPPER 90S WITH DEWPOINTS IN THE LOWER 70S.
THIS WILL PUSH HEAT INDICES INTO THE 105 TO 108 DEGREE RANGE. AS
SUCH...HAVE UPGRADED THIS REGION TO AN EXCESSIVE HEAT WARNING PER
LOCAL CRITERIA OF A HEAT INDEX OF 105. THE REMAINDER OF THE
REGION...EXCEPT MONTGOMERY COUNTY...REMAINS UNDER A HEAT ADVISORY
FOR HEAT INDICES RANGING FROM 100 TO 104. IT MUST BE NOTED THAT
SHOWERS AND STORMS WILL LIKELY COOL THINGS OFF SIGNIFICANTLY AND
THE HEAT ADVISORY/EXCESSIVE HEAT WARNING WILL LIKELY COME DOWN
BEFORE THE 8 PM EDT DEADLINE.
&&
.SHORT TERM /MIDNIGHT TONIGHT THROUGH FRIDAY NIGHT/...
DID NOT MAKE SWEEPING CHANGES TO THE TEMPERATURE FORECAST FOR THE
NEXT 3 PERIODS BUT DID LOWER HIGHS A BIT IN THE NORTHWEST ON
FRIDAY.
LOWERED POPS TONIGHT BY A BUNCH IN THE 6-12Z TIME FRAME AND EXPECT
THINGS TO RAMP UP QUICKLY TOMORROW MORNING AS THE PROXIMITY OF THE
LOW INTERACTS WITH A RECEPTIVE ATMOSPHERE WITH THE INTRODUCTION OF
DAYTIME HEATING. FEEL THAT THE 3-6Z TIME FRAME THIS EVENING IS A
LITTLE OVERDONE WITH THE CONTINUED HIGHER CHANCES OF RAIN BUT WILL
WAIT UNTIL THE FIRST ROUND OF SEVERE WEATHER CROSSES BEFORE I AM
COMFORTABLE ENOUGH TO SOUND THE ALL CLEAR...PARTICULARLY IN THE
NORTHWEST.
DECREASED THE CHANCE FOR RAIN SIGNIFICANTLY TOMORROW NIGHT ACROSS
THE BOARD AS DRIER AIR WILL FILTER IN BEHIND THE LOW.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
FOR SATURDAY THROUGH MONDAY...MODELS AND ENSEMBLES AT LEAST AGREE
ON THE UPPER LEVEL PATTERN...WITH REGION SITUATED ON EASTERN SIDE
OF PLAINS/ROCKIES RIDGE. FOR SATURDAY...THE COLD FRONT WILL BE TO
OUR EAST...WITH A SFC LOW EXITING NEW ENGLAND. SOME OF THE MODELS
ARE INDICATING A SECONDARY SFC REFLECTION DEVELOPING AS A
SHORTWAVE TROUGH DIVES THROUGH THE GREAT LAKES. COMBINED WITH WEAK
INSTBY...THIS COULD SPARK A FEW SHOWERS/STORMS OVER THE UPPER OHIO
VALLEY. SO HAVE MAINTAINED THE 20 POPS OVER OUR EASTERN TIER OR
TWO OF COUNTIES DURING THE AFTERNOON. OTHERWISE SFC HIGH PRESSURE
WILL BE BUILDING IN FROM THE WEST WITH COOLER AND DRIER AIR
ADVECTING INTO THE CWA. SUNDAY HAS THE HIGHEST FORECAST CONFIDENCE
AS SFC HIGH PRESSURE BUILDS DIRECTLY OVER THE CWA. TEMPERATURES
WILL BE NEAR OR SLIGHTLY BELOW SEASONABLE VALUES WITH FAIRLY LOW
HUMIDITY.
THE GFS TAKES A MORE SLIGHTLY MORE AMPLIFIED TURN BEGINNING
MONDAY...WITH PROJECTIONS OF A DEEPENING EAST COAST LONGWAVE TROUGH.
HOWEVER MODELS REMAIN IN CLOSE ENOUGH AGREEMENT TO TAKE AN ENSEMBLE
APPROACH WITH THE FORECAST. THERE IS CONTINUED AGREEMENT THAT
TUESDAY WILL HAVE THE HIGHEST PCPN CHANCES...AS A SFC BOUNDARY/UPPER
WAVE SAGS DOWN INTO THE AREA. SOME ACTIVITY MAY REACH THE NORTHWEST
BY MONDAY AFTERNOON...AND LINGER INTO WEDNESDAY DEPENDING ON THE
TIMING OF THE DISTURBANCES IN THE NORTHWEST FLOW. AT THIS
TIME...WEAK HIGH PRESSURE IS ANTICIPATED FOR THURSDAY. TEMPERATURES
WILL RISE SLIGHTLY BEGINNING MONDAY...BUT SHOULD NOT VARY
SIGNIFICANTLY FROM AVERAGE THROUGH THE WEEK WITH THE HEAT DOME
REMAINING WELL TO OUR WEST.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
UNDER A SOUTHWEST TO WEST FLOW ALOFT...A COLD FRONT WILL SAG
SOUTHEAST INTO THE NRN REACHES OF THE FORECAST AREA OVERNIGHT WHERE
IT WILL LIKELY STALL OUT. OTHERWISE...SHOWER AND THUNDERSTORM
PROBABILITIES WILL BE HIGH THIS AFTERNOON AND EVENING AS
CLUSTERS/LINES OF THUNDERSTORMS MOVE E/SE ACRS THE REGION. THE
MAIN THREAT WILL BE DAMAGING WINDS. MODE OF THUNDERSTORMS ARE
STILL UNCLEAR AT THIS POINT...SO HAVE NOT TRIED TO PINPOINT WIND
STRENGTH AT THE TAFS...KNOWING THAT AMENDMENTS WILL HAVE TO BE
EMPLOYED IF AND WHEN IT BECOMES NECESSARY. LOCALLY HEAVY RAIN WITH
IFR VSBYS AND MVFR CIGS WILL LIKELY OCCUR.
FOR THE OVERNIGHT PERIOD...MODELS SUGGEST THAT DEEPER MOISTURE AND
FORCING WILL SHIFT E/SE OF THE TAF SITES...LEAVING MAINLY A DRY
PERIOD OVERNIGHT. WILL GO WITH VFR CONDITIONS DURING THIS PERIOD.
ON FRIDAY...A DISTURBANCE WILL DIG SE TOWARD THE GREAT LAKES
REGION. THIS WILL PERTURB A WAVE OF LOW PRESSURE ALONG STALLED
OUT FRONTAL BOUNDARY. MOISTURE AND INSTABILITY ASSOCIATED WITH THE
LOW AND DISTURBANCE WILL RESULT IN CONVECTION DURING THE AFTN AND
EVENING HOURS ONCE AGAIN.
OUTLOOK...THUNDERSTORMS ARE POSSIBLE THROUGH FRIDAY NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR OHZ070-071.
EXCESSIVE HEAT WARNING UNTIL 8 PM EDT THIS EVENING FOR OHZ055-
056-061-063>065-072>074-077>082-088.
KY...EXCESSIVE HEAT WARNING UNTIL 8 PM EDT THIS EVENING FOR
KYZ089>100.
IN...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR INZ066-073-074.
EXCESSIVE HEAT WARNING UNTIL 8 PM EDT THIS EVENING FOR INZ075-
080.
&&
$$
SYNOPSIS...FRANKS
NEAR TERM...FRANKS/HICKMAN
SHORT TERM...FRANKS
LONG TERM...SNYDER
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
119 PM EDT THU JUL 26 2012
.SYNOPSIS...
HOT AND HUMID CONDITIONS WILL GIVE WAY TO STRONG TO SEVERE
THUNDERSTORMS THIS AFTERNOON AND EVENING AS A COLD FRONT MOVES
SOUTHEAST TOWARD THE OHIO VALLEY. THE FRONT WILL PUSH INTO THE
AREA TONIGHT AND A LOW PRESSURE SYSTEM WILL CROSS OUR AREA ON
FRIDAY...BRINGING ADDITIONAL SHOWERS AND THUNDERSTORMS TO THE
REGION. HIGH PRESSURE WILL THEN BRING MORE SEASONABLE TEMPERATURES
AND DRIER CONDITIONS FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THERE IS MUCH TO TALK ABOUT ON WHAT SHOULD BE AN ACTIVE SEVERE
EVENT THIS AFTERNOON AND EVENING ACRS OUR REGION.
SYNOPTICALLY SPEAKING...THE GREAT LAKES AND OHIO VALLEY WILL
REMAIN UNDER A SOUTHWEST TO WEST FLOW ALOFT TODAY INTO TONIGHT. A
COLD FRONT IS FORECAST TO DROP SOUTHEAST INTO THE REGION LATE IN
THE DAY AND MAY HANG UP ACRS THE NRN AREAS OVERNIGHT. LOOKING AT
SATELLITE IMAGERY...IT SHOULD BE NOTED THAT THERE ARE SEVERAL
EMBEDDED DISTURBANCES IN THE SOUTHWEST TO WEST FLOW ALOFT
EXTENDING FROM MISSOURI NORTHEAST INTO THE WESTERN GREAT LAKES.
TWO FEATURES FROM ERN MISSOURI INTO WESTERN ILLINOIS MAY BE THE
IMPETUS TO GET A QLCS GOING ACRS CENTRAL/SOUTH CENTRAL INDIANA
EARLY THIS AFTN. SFC OBSERVATIONS ALSO INDICATE THAT THERE IS A
PREFRONTAL TROF IN THIS REGION AS WELL. IF THIS GETS GOING AS THE
LATEST HRRR INDICATES...IT SHOULD INTENSIFY AS IT MOVES
EAST/SOUTHEAST ACRS OUR REGION DURING THE AFTERNOON AND EVENING
HOURS AS IT FEEDS INTO A VERY UNSTABLE AIRMASS OF 2500-3500 J/KG
OF MLCAPE. IT ALSO WILL HAVE THE ORGANIZATION AND MOMENTUM TO MOVE
QUICKLY AS BULK SHEAR BETWEEN 0=6 KM ARE AROUND 40 KNOTS. GIVEN
THAT FLOW WILL BE MAINLY UNIDIRECTIONAL...FEEL TORNADO THREAT WILL
BE MINIMAL WHILE DAMAGING WINDS AND HAIL SHOULD BE THE MAIN
THREATS. IN FACT...IT IS THE DAMAGING WIND POTENTIAL THAT WILL
LIKELY BE THE HIGHEST IMPACT DUE TO 50 KNOT MID LEVEL JET MOVING
ACRS THE REGION...STEEP LOW LEVEL LAPSE RATES...DELTA THREAT E
VALUES OF 25 KELVIN AND DCAPES OF 1000-1500 J/KG. ALTHOUGH TREE
DAMAGE AND POWER OUTAGES MAY OCCUR...ATTM...WE EXPECT THIS FEATURE
TO BEHAVE MORE LIKE A QLCS/BOW ECHO FEATURE AND NOT MIMIC THE JUNE
29 DERECHO THAT CAUSED EXTENSIVE/WIDESPREAD DAMAGE OVER MOST OF
THE ENTIRE REGION. THAT SAID...THERE WILL BE WIND DAMAGE AND OF
COURSE THERE COULD BE POCKETS OF ENHANCED WIND DAMAGE WITH ANY
OUTFLOW/GUST FRONT OR MICROBURST. THUS...THE SPC HAS KEPT MOST OF
OUR AREA IN A MODERATE RISK FOR SEVERE THUNDERSTORMS. PWATS WILL BE
HIGH...IN EXCESS OF 2 INCHES...WITH THE THUNDERSTORM ACTIVITY SO
LOCALLY HEAVY RAIN AND LOCALIZED FLOODING WILL BE POSSIBLE BUT
SHOULD BE LIMITED GIVEN THE SPEED AT WHICH STORMS WILL BE MOVING.
A HOT AND HUMID AIRMASS WILL BE IN PLACE FOR THESE THUNDERSTORMS
TO FEED ON. GIVEN THE AMOUNT OF SUNSHINE OCCURRING OVER THE ERN/SRN
AREAS THIS MORNING...AND THE FACT THAT KILN SOUNDING AND MODEL
SOUNDINGS INDICATE THAT 850 MB TEMPS WILL BE IN THE 23-24 C
RANGE...BELIEVE A GOOD CHUNK OF THIS REGION WILL SEE TEMPERATURES
PEAK INTO THE MID AND UPPER 90S WITH DEWPOINTS IN THE LOWER 70S.
THIS WILL PUSH HEAT INDICES INTO THE 105 TO 108 DEGREE RANGE. AS
SUCH...HAVE UPGRADED THIS REGION TO AN EXCESSIVE HEAT WARNING PER
LOCAL CRITERIA OF A HEAT INDEX OF 105. THE REMAINDER OF THE
REGION...EXCEPT MONTGOMERY COUNTY...REMAINS UNDER A HEAT ADVISORY
FOR HEAT INDICES RANGING FROM 100 TO 104. IT MUST BE NOTED THAT
SHOWERS AND STORMS WILL LIKELY COOL THINGS OFF SIGNIFICANTLY AND
THE HEAT ADVISORY/EXCESSIVE HEAT WARNING WILL LIKELY COME DOWN
BEFORE THE 8 PM EDT DEADLINE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
CONVECTION WILL SHIFT SOUTHEAST LATE THIS EVENING AND WITH THE
LOSS OF DAYTIME HEATING...WILL GRADUALLY LOSE IT/S INTENSITY.
HOWEVER...STORMS WILL STILL BE INTENSE ENOUGH TO PRODUCE SEVERE
WEATHER AT LEAST THROUGH THE FIRST PART OF THE OVERNIGHT PERIOD.
HAVE THEREFORE KEPT THE MENTION OF SEVERE STORMS IN THE GRIDS
THROUGH 03Z. BY THAT TIME...MOST ACTIVITY WILL HAVE SHIFTED TO OUR
SOUTHEASTERN ZONES. THERE...SOME ONGOING CONVECTIVE ACTIVITY COULD
POSE ADDITIONAL FLOOD ISSUES ALONG AND SOUTH OF THE OHIO RIVER
SHOULD THUNDERSTORMS BEGIN TO TRAIN OVER THE SAME LOCATIONS LATE
TONIGHT.
ON FRIDAY THERE ARE STILL SOME DIFFERENCES ON HOW THE MODELS HANDLE
THE SHORTWAVE PIVOTING ACROSS THE GREAT LAKES. THE SREF AND NAM
DEVELOP A WEAK CLOSED SURFACE LOW AHEAD OF THE TROUGH AND DIVE IT
SOUTHWARD TOWARD OUR AREA. THIS WOULD PRODUCE A ROUND OF AFTERNOON
CONVECTION FOR THE EASTERN TWO THIRDS OF THE FORECAST AREA. THE
ARW AND NMM BOTH AGREE WITH THIS SOLUTION. HAVE FORECAST 50/50 POPS
FOR MUCH OF THE AREA FOR FRIDAY AFTERNOON TO REFLECT THIS. DID NOT
GO LIKELY ON POPS SINCE THE ECMWF STILL DOES NOT AGREE WITH THIS
SOLUTION.
REGARDLESS OF WHICH MODEL YOU CHOOSE FROM...COLD ADVECTION FINALLY
STABILIZES US FRIDAY NIGHT AS HIGH PRESSURE BEGINS TO BUILD ACROSS
THE OHIO VALLEY. A FEW RESIDUAL SHOWERS AND THUNDERSTORMS COULD
LINGER INTO SATURDAY ACROSS THE EAST AS THE SFC LOW DEPARTS.
SATURDAY THROUGH SATURDAY NIGHT WILL MARK A RETURN TO MORE
SEASONABLE TEMPERATURES AS THE SFC HIGH PRESSURE SETTLES ACROSS
THE REGION.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
SUNDAY IS PROBABLY THE DAY WITH HIGHEST FORECAST CONFIDENCE AS
SFC HIGH PRESSURE BUILDS OVER THE CWA. TEMPERATURES WILL BE
SEASONABLE WITH FAIRLY LOW HUMIDITY.
THE GFS/NCEP MODELS TAKES A MORE AMPLIFIED TURN BEGINNING
MONDAY...WITH 500 MB HEIGHTS AT ILN RESIDING ON THE LOW END OF NAEFS
SPREAD BY MID WEEK. THIS AFFECTS PCPN FORECASTS MORE THAN
TEMPERATURES HOWEVER OVER THE LOCAL AREA (AS 00Z AND 12Z ECMWF HOLD
A STRONGER SFC RIDGE IN PLACE). TOOK AN ENSEMBLE APPROACH WITH THE
FORECAST...WHICH DID NOT SIGNIFICANTLY CHANGE THE GOING FORECAST.
TUESDAY WILL HAVE THE HIGHEST PCPN CHANCES...SUPPORTED BY
ENSEMBLES...AS WELL AS A SFC BDY/UPPER WAVE THAT MAY SAG DOWN INTO
THE AREA. CANNOT TOTALLY RULE OUT PCPN MONDAY/WEDNESDAY BUT LIMITED
TO 20 POPS. TEMPERATURES WILL RISE SOME AS LOW LEVEL FLOW BECOME
MORE SOUTHERLY...BUT AT THIS TIME LOOK TO REMAIN WITHIN 5 DEGREES OF
NORMAL. HUMIDITY WILL ALSO INCREASE SLIGHTLY...HOLDING UP OVERNIGHT
LOWS.
&&
.AVIATION /17Z THURSDAY THROUGH MONDAY/...
UNDER A SOUTHWEST TO WEST FLOW ALOFT...A COLD FRONT WILL SAG
SOUTHEAST INTO THE NRN REACHES OF THE FORECAST AREA OVERNIGHT WHERE
IT WILL LIKELY STALL OUT. OTHERWISE...SHOWER AND THUNDERSTORM
PROBABILITIES WILL BE HIGH THIS AFTERNOON AND EVENING AS
CLUSTERS/LINES OF THUNDERSTORMS MOVE E/SE ACRS THE REGION. THE
MAIN THREAT WILL BE DAMAGING WINDS. MODE OF THUNDERSTORMS ARE
STILL UNCLEAR AT THIS POINT...SO HAVE NOT TRIED TO PINPOINT WIND
STRENGTH AT THE TAFS...KNOWING THAT AMENDMENTS WILL HAVE TO BE
EMPLOYED IF AND WHEN IT BECOMES NECESSARY. LOCALLY HEAVY RAIN WITH
IFR VSBYS AND MVFR CIGS WILL LIKELY OCCUR.
FOR THE OVERNIGHT PERIOD...MODELS SUGGEST THAT DEEPER MOISTURE AND
FORCING WILL SHIFT E/SE OF THE TAF SITES...LEAVING MAINLY A DRY
PERIOD OVERNIGHT. WILL GO WITH VFR CONDITIONS DURING THIS PERIOD.
ON FRIDAY...A DISTURBANCE WILL DIG SE TOWARD THE GREAT LAKES
REGION. THIS WILL PERTURB A WAVE OF LOW PRESSURE ALONG STALLED
OUT FRONTAL BOUNDARY. MOISTURE AND INSTABILITY ASSOCIATED WITH THE
LOW AND DISTURBANCE WILL RESULT IN CONVECTION DURING THE AFTN AND
EVENING HOURS ONCE AGAIN.
OUTLOOK...THUNDERSTORMS ARE POSSIBLE THROUGH FRIDAY NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR OHZ026-034-035-
042>046-051>054-060-062-070-071.
EXCESSIVE HEAT WARNING UNTIL 8 PM EDT THIS EVENING FOR OHZ055-
056-061-063>065-072>074-077>082-088.
KY...EXCESSIVE HEAT WARNING UNTIL 8 PM EDT THIS EVENING FOR
KYZ089>100.
IN...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR INZ050-058-059-
066-073-074.
EXCESSIVE HEAT WARNING UNTIL 8 PM EDT THIS EVENING FOR INZ075-
080.
&&
$$
SYNOPSIS...HICKMAN/LATTO
NEAR TERM...HICKMAN/LATTO
SHORT TERM...HICKMAN/LATTO
LONG TERM...SNYDER
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
443 PM EDT THU JUL 26 2012
.SYNOPSIS...
MOISTURE WILL BE ON THE INCREASE FRIDAY OUT AHEAD OF AN APPROACHING
WEAK COOL FRONT. THIS FRONT WILL SETTLE INTO AND MOVE THROUGH THE
REGION OVER THE WEEKEND. SURFACE HIGH PRESSURE WILL BUILD BACK OVER
THE AREA LATER SUNDAY AND REMAIN THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 440 PM...RADAR STILL PPINE THIS AFTERNOON. HOWEVER...THERE
HAVE BEEN A FEW ENHANCED ECHOES ACROSS THE MTNS THAT DID NOT DEVELOP
FURTHER. LATEST GUIDANCE STILL SUGGESTS ISOLATED CONVECTION POSSIBLE
ACROSS THE MTNS FOR LATE AFTERNOON AND EARLY EVENING WHERE CAP
SHOULD HAVE ERODED. WILL LEAVE THE CURRENT POP TRENDS IN PLACE.
UPDATES BASICALLY FOR CURRENT CONDITIONS ONLY.
AT 215 PM...CURRENT TEMP TREND NOW BEGINNING TO LAG SOMEWHAT
SO HAVE ADJUSTED TEMP TREND. MAY JUST MARGINALLY HIT THE HEAT
ADVISORY CRITERIA ACROSS THE SOUTHERN PIEDMONT AREAS LATE THIS
AFTERNOON AS DEWPOINTS MIX OUT A TAD. HOWEVER...WILL LEAVE THE
CURRENT HEAT ADVISORY IN PLACE. STILL EXPECT THAT ANY DEEP
CONVECTION THIS AFTERNOON WILL BE WIDELY SCATTERED OVER THE HIGH
TERRAIN OF WESTERN NC AS LFC`S DROP TO AROUND 5K FT. A CAPPING
INVERSION IN THE 5K-8K RANGE OUTSIDE THE MOUNTAINS SHOULD PRECLUDE
ANY THREAT FOR DEEP CONVECTION THERE. THE EXCEPTION OUTSIDE THE
MOUNTAINS IS OVER PARTS OF NE GA AND THE WESTERN UPSTATE WHERE
WIDELY SCT THUNDERSTORMS MAY OCCUR IN THE 00Z-03Z TIMEFRAME AS A
WEAK VORT MAX MOVES NE OUT OF GA. 12Z NAM/GFS AND RAP ALL SHOWING
SOME CONVECTIVE RESPONSE IN THAT AREA.
AFTER MIDNIGHT...IT LOOKS LIKE LIKE IT WILL BE QUIET WITH MOSTLY
CLEAR CONDITIONS. IT WILL BE AN UNSEASONABLY WARM NIGHT UNDER THE
DEPARTING UPPER RIDGE. LOWS WILL BE A GOOD 5 DEGREES ABOVE AVERAGE.
ON FRI...CONDITIONS FOR DEEP CONVECTION WILL BECOME MORE FAVORABLE
THROUGHOUT THE DAY AS A SHORT WAVE MOVES THROUGH THE GREAT LAKES WHICH
LOWERS HEIGHTS OVER THE EASTERN U.S. AT THE SAME TIME...A WEAK
FRONTAL BOUNDARY WILL APPROACH FROM THE NW. WIND FIELDS WILL ALSO
IMPROVE WITH SFC-6KM BULK SHEAR INCREASING TO AROUND 20KTS FRI
AFTERNOON. HENCE...EXPECT SCT TO NUMEROUS THUNDERSTORMS TO DEVELOP
OVER THE NC MOUNTAINS DURING THE EARLY AFTERNOON WITH AT LEAST
SCATTERED STORMS PROGRESSING SE INTO THE PIEDMONT AREAS IN THE MID
TO LATE AFTERNOON HOURS. SEVERE STORMS ARE POSSIBLE PER THE LATEST
SPC DAY 2 OUTLOOK WHICH HAS MOST OF THE AREA IN A SLIGHT RISK. FRI
WILL BE ANOTHER HOT DAY...ESPECIALLY OUTSIDE THE MOUNTAINS WHERE MID
TO UPPER 90S ARE EXPECTED. WITH DEWPOINTS IN THE LOWER 70S OUTSIDE
THE MOUNTAINS...HEAT ADVISORY CONDITIONS (105-110) SHOULD BE MET OVER THE
SOUTHERN PIEDMONT AREAS ONCE AGAIN. WILL GO AHEAD AND ISSUE A HEAT
ADVISORY FOR THAT AREA FOR FRI AFTERNOON.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AT 215 PM EDT THURSDAY...AN UPPER TROUGH AXIS WILL REMAIN OVER THE
EASTERN USA FROM FRIDAY NIGHT THROUGH SUNDAY. A VIGOROUS SHORTWAVE
WILL DIVE INTO THE BASE OF THIS TROUGH ON FRIDAY NIGHT...CROSSING
THE SOUTHERN APPALACHIANS ON SATURDAY. A WEAKER SHORTWAVE WILL
FOLLOW...CROSSING THE MOUNTAINS ON SUNDAY. THE REMAINS OF A COLD
FRONT WILL MOVES SOUTHEAST ACROSS THE PIEDMONT FRIDAY NIGHT...WHILE
ANOTHER COLD FRONT...WHILE A NEW COLD FRONT AND ITS MOISTURE BAND
CROSS THE MOUNTAINS FROM THE NW. THIS SECOND FRONT REACHES THE
PIEDMONT BY SATURDAY AFTERNOON. DRYING OCCURS BEHIND THE SECOND
FRONT SATURDAY NIGHT AS IT DRIFTS INTO THE PIEDMONT...HOWEVER THE
GFS KEEP SOME MOISTURE BANKED UP AGAINST THE BLUE RIDGE INTO SUNDAY.
CHANCE POPS WILL BE CARRIED WITH THE TWO FRONTS CROSSING THE
AREA...WITH MAXIMUM POPS DURING DAYTIME HEATING. CAPE IS EXPECTED TO
BE AT A MAXIMUM ALONG AND AHEAD OF THE PRIMARY BOUNDARY SATURDAY
AFTERNOON. NAM SOUNDINGS LOOK MORE FAVORABLE FOR SEVERE WEATHER THAN
GFS SOUNDINGS. A DECREASE IN POPS WILL BE PERMITTED BEHIND THE FRONT
SATURDAY NIGHT AND SUNDAY...BUT SMALL POPS WILL LINGER ALONG THE
BLUE RIDGE PER THE GFS SOLUTION... AS THE SECOND AND WEAKER
SHORTWAVE ARRIVES. LIFT AND MOISTURE WITH THE SECOND SHORTWAVE ARE
DEPICTED AS BEING MORE SHALLOW THAN WITH THE FIRST. TEMPERATURES
WILL BE ABOVE NORMAL...BUT WITH A SLIGHT DECREASE ON SUNDAY IN THE
WAKE OF THE SECOND FRONT. THE HEAT INDEX WILL REMAIN BELOW 100
DEGREE IN THE PIEDMONT SATURDAY...AND WILL BE EVEN LOWER ON SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 140 PM THURSDAY...MEDIUM RANGE MODELS REMAIN IN GOOD AGREEMENT
WITH RESPECT TO THE GENERAL PATTERN TO START OFF THE PERIOD...THE
CWFA ORIENTED NEAR THE BASE OF EASTERN CONUS TROUGH. THE WEAK SFC
FRONT WHICH IS PROGGED TO SLIP INTO THE CAROLINAS THIS WEEKEND IS
FCST TO STEADILY WEAKEN AS IT STALLS ACRS THE COASTAL PLAIN. ON A
REGIONAL SCALE...GREATEST DIURNAL TSTM CVRG SHOULD WIND UP ORIENTED
ALONG AND COASTWARD OF SFC FRONT...BUT APPROACHING IMPULSE WITHIN
THE WNW FLOW SHOULD BE ABLE TO TRIGGER AT LEAST SCATTERED ACTIVITY
ACRS THE WESTERN CAROLINAS ON TUESDAY. MAX TEMPERATURES FOR THE NEW
DAY 4 AND 5 WILL BE PRETTY TYPICAL FOR LATE JULY...WITHIN A FEW DEG
F OF CLIMO. DURING THE LATTER HALF OF THE PERIOD...AFOREMENTIONED SFC
FRONT BECOMES INCREASINGLY FRONTOLYTIC AND THE MEAN PATTERN...
EASTERN CONUS TROUGH...CHANGES LITTLE. GIVEN THE AMPLITUDE OF THE
PATTERN AND THE POTENTIAL FOR ADDITIONAL CHUNKS OF ENERGY TO ROTATE
THRU...FEEL THAT SOLID MAINLY DIURNAL TSTM CHANCES WILL EXIST EACH
DAY WITH TEMPERATURES STILL VERY CLOSE TO CLIMO.
&&
.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
AT KCLT...CONVECTIVE THREAT APPEARS NIL THIS AFTERNOON AS A CAPPING
INVERSION IS EXPECTED TO HOLD FIRM. EXPECT MCLR SKIES THROUGH
TONIGHT WITH SCT CU DEVELOPING LATE FRI MORNING. WINDS WILL REMAIN
GENERALLY LIGHT SW...EXCEPT FOR A FEW GUSTS TO AROUND 12KT LATE THIS
AFTERNOON.
ELSEWHERE...SIMILAR CONDITIONS TO KCLT EXCEPT FOR SOME LIGHT FOG AT
KAVL EARLY FRI. SLIGHT CHC POPS SHOULD REMAIN LIMITED TO THE MTNS THIS
AFTN.
OUTLOOK...CHANCE FOR THUDNERSTORMS WILL INCREASE FRI AS A SHORTWAVE
AND ASSOC WEAK COLD FRONT MOVE IN FROM THE NW. ANOTHER CHANCE FOR
THUNDERSTORMS WILL OCCUR SAT AFTERNOON AS ANOTHER COLD FRONT MOVES
THROUGH. THEN EXPECT A DAILY CHANCE FOR AFTERNOON CONVECTION INTO
THE MIDDLE OF NEXT WEEK...FIRST OVER SOUTHERN AREAS ON SUNDAY THEN
AREA WIDE AS UPPER TROF REMAINS OVER THE AREA.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR GAZ029.
HEAT ADVISORY FROM NOON TO 7 PM EDT FRIDAY FOR GAZ029.
NC...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR NCZ071-072-082.
HEAT ADVISORY FROM NOON TO 7 PM EDT FRIDAY FOR NCZ071-072-082.
SC...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR SCZ009-011>014-
019.
HEAT ADVISORY FROM NOON TO 7 PM EDT FRIDAY FOR SCZ009-011>014-
019.
&&
$$
SYNOPSIS...CSH
NEAR TERM...LG/RWH
SHORT TERM...JAT
LONG TERM...CSH
AVIATION...LG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
218 PM EDT THU JUL 26 2012
.SYNOPSIS...
MOISTURE WILL BE ON THE INCREASE FRIDAY OUT AHEAD OF AN APPROACHING
WEAK COOL FRONT. THIS FRONT WILL SETTLE INTO AND MOVE THROUGH THE
REGION OVER THE WEEKEND. SURFACE HIGH PRESSURE WILL BUILD BACK OVER
THE AREA LATER SUNDAY AND REMAIN THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH FRIDAY/...
AT 215 PM...CURRENT TEMP/DEWPOINT TREND NOW BEGINNING TO LAG
SOMEWHAT SO HAVE ADJUSTED TEMP TREND. MAY JUST MARGINALLY HIT THE
HEAT ADVISORY CRITERIA ACROSS THE SOUTHERN PIEDMONT AREAS LATE THIS
AFTERNOON AS DEWPOINTS MIX OUT A TAD. HOWEVER...WILL LEAVE THE
CURRENT HEAT ADVISORY IN PLACE. STILL EXPECT THAT ANY DEEP
CONVECTION THIS AFTERNOON WILL BE WIDELY SCATTERED OVER THE HIGH
TERRAIN OF WESTERN NC AS LFC`S DROP TO AROUND 5K FT. A CAPPING
INVERSION IN THE 5K-8K RANGE OUTSIDE THE MOUNTAINS SHOULD PRECLUDE
ANY THREAT FOR DEEP CONVECTION THERE. THE EXCEPTION OUTSIDE THE
MOUTNAINS IS OVER PARTS OF NE GA AND THE WESTERN UPSTATE WHERE
WIDELY SCT THUNDERSTORMS MAY OCCUR IN THE 00Z-03Z TIMEFRAME AS A
WEAK VORT MAX MOVES NE OUT OF GA. 12Z NAM/GFS AND RAP ALL SHOWING
SOME CONVECTIVE RESPONSE IN THAT AREA.
AFTER MIDNIGHT...IT LOOKS LIKE LIKE IT WILL BE A QUIET WITH MOSTLY
CLEAR CONDITIONS. IT WILL BE AN UNSEASONABLY WARM NIGHT UNDER THE
DEPARTING UPPER RIDGE. LOWS WILL BE A GOOD 5 DEGREES ABOVE AVERAGE.
ON FRI...CONDITIONS FOR DEEP CONVECTION WILL BECOME MORE FAVORABLE
THROUGHOUT THE DAY AS A SHORT WAVE MOVES THROUGH THE GREAT LAKES WHICH
LOWERS HEIGHTS OVER THE EASTERN U.S. AT THE SAME TIME...A WEAK
FRONTAL BOUNDARY WILL APPROACH FROM THE NW. WIND FIELDS WILL ALSO
IMPROVE WITH SFC-6KM BULK SHEAR INCREASING TO AROUND 20KTS FRI
AFTERNOON. HENCE...EXPECT SCT TO NUMEROUS THUNDERSTORMS TO DEVELOP
OVER THE NC MOUNTAINS DURING THE EARLY AFTERNOON WITH AT LEAST
SCATTERED STORMS PROGRESSING SE INTO THE PIEDMONT AREAS IN THE MID
TO LATE AFTERNOON HOURS. SEVERE STORMS ARE POSSIBLE PER THE LATEST
SPC DAY 2 OUTLOOK WHICH HAS MOST OF THE AREA IN A SLIGHT RISK. FRI
WILL BE ANOTHER HOT DAY...ESPECIALLY OUTSIDE THE MOUNTAINS WHERE MID
TO UPPER 90S ARE EXPECTED. WITH DEWPOINTS IN THE LOWER 70S OUTSIDE
THE MOUNTAINS...HEAT ADVISORY CONDITIONS (105-110) SHOULD BE MET OVER THE
SOUTHERN PIEDMONT AREAS ONCE AGAIN. WILL GO AHEAD AND ISSUE A HEAT
ADVISORY FOR THAT AREA FOR FRI AFTERNOON.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AT 215 PM EDT THURSDAY...AN UPPER TROUGH AXIS WILL REMAIN OVER THE
EASTERN USA FROM FRIDAY NIGHT THROUGH SUNDAY. A VIGOROUS SHORTWAVE
WILL DIVE INTO THE BASE OF THIS TROUGH ON FRIDAY NIGHT...CROSSING
THE SOUTHERN APPALACHIANS ON SATURDAY. A WEAKER SHORTWAVE WILL
FOLLOW...CROSSING THE MOUNTAINS ON SUNDAY. THE REMAINS OF A COLD
FRONT WILL MOVES SOUTHEAST ACROSS THE PIEDMONT FRIDAY NIGHT...WHILE
ANOTHER COLD FRONT...WHILE A NEW COLD FRONT AND ITS MOISTURE BAND
CROSS THE MOUNTAINS FROM THE NW. THIS SECOND FRONT REACHES THE
PIEDMONT BY SATURDAY AFTERNOON. DRYING OCCURS BEHIND THE SECOND
FRONT SATURDAY NIGHT AS IT DRIFTS INTO THE PIEDMONT...HOWEVER THE
GFS KEEP SOME MOISTURE BANKED UP AGAINST THE BLUE RIDGE INTO SUNDAY.
CHANCE POPS WILL BE CARRIED WITH THE TWO FRONTS CROSSING THE
AREA...WITH MAXIMUM POPS DURING DAYTIME HEATING. CAPE IS EXPECTED TO
BE AT A MAXIMUM ALONG AND AHEAD OF THE PRIMARY BOUNDARY SATURDAY
AFTERNOON. NAM SOUNDINGS LOOK MORE FAVORABLE FOR SEVERE WEATHER THAN
GFS SOUNDINGS. A DECREASE IN POPS WILL BE PERMITTED BEHIND THE FRONT
SATURDAY NIGHT AND SUNDAY...BUT SMALL POPS WILL LINGER ALONG THE
BLUE RIDGE PER THE GFS SOLUTION... AS THE SECOND AND WEAKER
SHORTWAVE ARRIVES. LIFT AND MOISTURE WITH THE SECOND SHORTWAVE ARE
DEPICTED AS BEING MORE SHALLOW THAN WITH THE FIRST. TEMPERATURES
WILL BE ABOVE NORMAL...BUT WITH A SLIGHT DECREASE ON SUNDAY IN THE
WAKE OF THE SECOND FRONT.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
AS OF 140 PM THURSDAY...MEDIUM RANGE MODELS REMAIN IN GOOD AGREEMENT
WITH RESPECT TO THE GENERAL PATTERN TO START OFF THE PERIOD...THE
CWFA ORIENTED NEAR THE BASE OF EASTERN CONUS TROUGH. THE WEAK SFC
FRONT WHICH IS PROGGED TO SLIP INTO THE CAROLINAS THIS WEEKEND IS
FCST TO STEADILY WEAKEN AS IT STALLS ACRS THE COASTAL PLAIN. ON A
REGIONAL SCALE...GREATEST DIURNAL TSTM CVRG SHOULD WIND UP ORIENTED
ALONG AND COASTWARD OF SFC FRONT...BUT APPROACHING IMPULSE WITHIN
THE WNW FLOW SHOULD BE ABLE TO TRIGGER AT LEAST SCATTERED ACTIVITY
ACRS THE WESTERN CAROLINAS ON TUESDAY. MAX TEMPERATURES FOR THE NEW
DAY 4 AND 5 WILL BE PRETTY TYPICAL FOR LATE JULY...WITHIN A FEW DEG
F OF CLIMO. DURING THE LATTER HALF OF THE PERIOD...AFOREMENTIONED SFC
FRONT BECOMES INCREASINGLY FRONTOLYTIC AND THE MEAN PATTERN...
EASTERN CONUS TROUGH...CHANGES LITTLE. GIVEN THE AMPLITUDE OF THE
PATTERN AND THE POTENTIAL FOR ADDITIONAL CHUNKS OF ENERGY TO ROTATE
THRU...FEEL THAT SOLID MAINLY DIURNAL TSTM CHANCES WILL EXIST EACH
DAY WITH TEMPERATURES STILL VERY CLOSE TO CLIMO.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AT KCLT...CONVECTIVE THREAT APPEARS NIL THIS AFTERNOON AS A CAPPING
INVERSION IS EXPECTED TO HOLD FIRM. EXPECT MCLR SKIES THROUGH
TONIGHT WITH SCT CU DEVELOPING LATE FRI MORNING. WINDS WILL REMAIN
GENERALLY LIGHT SW...EXCEPT FOR A FEW GUSTS TO AROUND 12KT LATE THIS
AFTERNOON.
ELSEWHERE...SIMILAR CONDITIONS TO KCLT EXCEPT FOR SOME LIGHT FOG AT
KAVL EARLY FRI. SLIGHT CHC POPS SHOULD REMAIN LIMITED TO THE MTNS THIS
AFTN.
OUTLOOK...CHANCE FOR THUDNERSTORMS WILL INCREASE FRI AS A SHORTWAVE
AND ASSOC WEAK COLD FRONT MOVE IN FROM THE NW. ANOTHER CHANCE FOR
THUNDERSTORMS WILL OCCUR SAT AFTERNOON AS ANOTHER COLD FRONT MOVES
THROUGH. THEN EXPECT A DAILY CHANCE FOR AFTERNOON CONVECTION INTO
THE MIDDLE OF NEXT WEEK...FIRST OVER SOUTHERN AREAS ON SUNDAY THEN
AREA WIDE AS UPPER TROF REMAINS OVER THE AREA.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR GAZ029.
HEAT ADVISORY FROM NOON TO 7 PM EDT FRIDAY FOR GAZ029.
NC...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR NCZ071-072-082.
HEAT ADVISORY FROM NOON TO 7 PM EDT FRIDAY FOR NCZ071-072-082.
SC...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR SCZ009-011>014-
019.
HEAT ADVISORY FROM NOON TO 7 PM EDT FRIDAY FOR SCZ009-011>014-
019.
&&
$$
SYNOPSIS...CSH
NEAR TERM...LG
SHORT TERM...JAT
LONG TERM...CSH
AVIATION...LG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
132 PM EDT THU JUL 26 2012
.SYNOPSIS...
MOISTURE WILL BE ON THE INCREASE FRIDAY OUT AHEAD OF AN APPROACHING
WEAK COOL FRONT. THIS FRONT WILL SETTLE INTO AND MOVE THROUGH THE
REGION OVER THE WEEKEND. SURFACE HIGH PRESSURE WILL BUILD BACK OVER
THE AREA LATER SUNDAY AND REMAIN THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT 100 PM...CURRENT TEMP/DEWPOINT TRENDS STILL ON TRACK. STILL
EXPECT THAT ANY DEEP CONVECTION THIS AFTERNOON WILL BE WIDELY
SCATTERED OVER THE HIGH TERRAIN OF WESTERN NC. ONLY ADJUSTMENT TO
POP GRID IS TO ADD WIDELY SCT THUNDERSTORMS IN THE 00Z-03Z TIMEFRAME
TO PARTS OF NE GA AND THE WESTERN UPSTATE AS A WEAK VORT MAX MOVES
NE OUT OF GA. 12Z NAM/GFS AND RAP SHOWING SOME CONVECTIVE RESPONSE
IN THAT AREA.
PREVIOUS DISCUSSION:
NAM BUFKIT SOUNDINGS FROM THE 06Z RUN INDICATE A SUBTLE WARM NOSE IN
THE 5K-8K LAYER AT ALL PIEDMONT SITES WHICH SERVES TO PUT A CAP ON
ANY DEEP CONVECTION. IN THE MOUNTAINS...LFC`S LOWER TO AROUND 5KFT
WHICH MAY BE ENOUGH TO ALLOW SOME ISOLATED STORMS TO DEVELOP OVER
THE HIGH TERRAIN BY MIDAFTERNOON. THEREFORE...WILL MAINTAIN THE
WIDELY SCATTERED COVERAGE TYPE POPS OVER THE MOUNTAINS FOR THIS
AFTERNOON. CONVECTION SHOULD RAPIDLY DIMINISH BY LATE DAY.
ISOLATED TO SCATTERED CONVECTION WILL COME TO AN END RATHER QUICKLY
THIS EVENING AS FURTHER WARMING ALOFT NEARLY CAPS SOUNDINGS. THE
MODEL DEPICT SOME INCREASE IN LOW LEVEL MOISTURE THIS EVENING AT
AROUND 850 MB...BUT THIS SHOULD RESULT IN NO MORE THAN SCATTERED LOW
CLOUDS. MINIMUM TEMPERATURES WILL BE ALMOST FIVE DEGREES ABOVE
NORMAL UNDER THE UPPER RIDGE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 230 AM EDT THURSDAY...THE SHORT TERM FCST PICKS UP AT 12Z ON
FRIDAY WITH AN UPPER TROF DEEPENING OVER THE SE CONUS AND A STEEP
UPPER RIDGE BUILDING HIGHER OVER THE WESTERN CONUS. THE TROF AXIS IS
EXPECTED TO MOVE OVER THE CAROLINAS SATURDAY AFTERNOON WITH A WEAK
H5 SHORTWAVE DROPPING DOWN THE BACKSIDE OF THE UPPER RIDGE BY THE
END OF THE PERIOD 12Z SUNDAY.
ON FRIDAY...A WEAK COLD FRONT WILL MOVE ACROSS THE SOUTHERN
APPALACHIANS DURING THE AFTERNOON AND REACH OUR DOORSTEP BY FRIDAY
EVENING. THE LATEST MODEL RUNS ARE SUGGESTING THAT THE PREFRONTAL
ENVIRONMENT MAY NOT BE AS UNSTABLE AS PREVIOUSLY EXPECTED WITH CAPE
VALUES TRENDING DOWNWARD INTO THE 1000 TO 1500 J/KG RANGE WITH
LITTLE CIN. THERE IS ALSO SOME UPPER LVL DIVERGENCE JUST AHEAD OF
THE FRONT MOSTLY CONFINED TO THE NC MTS. THE BEST UPPER FORCING
HOWEVER...LOOKS LIKE IT WILL REMAIN TO OUR NORTH. WE WILL PROBABLY
SEE SOME SORT OF LINE OF MULTICELL TS MOVING INTO WESTERN NC BY MID
TO LATE AFTERNOON WITH SOME OF THE CONVECTION BECOMING SEVERE...BUT ITS
LOOKING LIKE IT MAY NOT BE ABLE TO PUSH VERY FAR SE ONCE WE LOSE
DAYTIME SFC HEATING. THE LATE DAY CONVECTION SHOULD ALLOW HIGH TEMPS
TO REACH THE U90S AGAIN EAST OF THE MTNS. RETURN FLOW AHEAD OF THE
FRONT WILL SUPPORT DEWPOINT VALUES IN THE U60S. THE COMBINATION OF
HOT TEMPERATURES AND MODERATE HUMIDITY SHOULD PRODUCE HEAT INDEX
VALUES ALONG AND EAST OF I-85 NEAR 105 DEGREES DURING THE LATE
AFTERNOON. THEREFORE...HEAT ADVISORY CRITERIA MAY BE REACHED EAST OF
I-85.
ON SATURDAY...THE CWA SHOULD REMAIN IN A POST FRONTAL
ENVIRONMENT...WITH NW LLVL WINDS AND DOWNSLOPE FLOW. LOWER
THICKNESSES WILL SUPPORT HIGHS ABOUT A CATEGORY COOLER THAN THE
PREVIOUS COUPLE OF DAYS. FORECAST SOUNDINGS CONTINUE TO SHOWS CAPE
VALUES AROUND 2000 J/KG DURING THE AFTERNOON. HOWEVER...A SHALLOW
LAYER OF CIN MAY EXIST BELOW THE LFC AND AND A A WEAK MID LVL
INVERSION COULD LIMIT ANY DEEP CONVECTION. GIVEN THE INSTABILITY AND
THE PASSAGE OF THE MID LEVEL TROF...I KEPT A SLIGHT CHANCE POP OVER
MOST OF THE FCST AREA DURING THE AFTERNOON/EARLY EVENING. IF
CONVECTION DOES DEVELOP...FAVORABLE THETA-E LAPSE RATES COULD
SUPPORT A DAMAGING WET MICROBURST OR 2.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 215 AM EDT THURSDAY...THE MEDIUM RANGE FCST PICKS UP AT 12Z ON
SUNDAY WITH THE UPPER TROF AXIS MOVING OFF THE EASTERN SEABOARD AND
A WEAK H5 SHORTWAVE APPROACHING THE CWFA. OVER THE REMAINDER OF THE
PERIOD...WE STAY UNDER THE INFLUENCE OF THE UPPER TROF WHILE THE
UPPER RIDGE MAINTAINS ITSELF OVER THE MIDWEST. NO SIGNIFICANT
CHANGES WERE NEEDED TO THE FCST.
PREVIOUS DISCUSSION...
AS OF 200 PM EDT WEDNESDAY...THE LATEST MODELS CONTINUE TO
INDICATE THAT THE UPPER TROUGH PERSISTS OVER THE EASTERN CONUS AND A
BROAD UPPER LEVEL RIDGE OF HIGH PRESSURE REMAIN IN PLACE OVER THE
GREAT PLAINS THROUGH THE EXTENDED FORECAST PERIOD. AT THE
SURFACE...A FAIRLY STRONG HIGH PRESSURE IS EXPECTED TO BUILD ACROSS
THE REGION FROM THE NORTH BY LATE SATURDAY AND REMAINS THROUGH
SUNDAY FOR MOSTLY DRY WEATHER WITH SEASONABLY WARM TEMPERATURES. AS
THE HIGH MOVES OFF TO THE EAST MONDAY...A SURFACE LOW PRESSURE IS
EXPECTED TO DEVELOP OVER THE CAROLINAS AND LINGERS INTO WEDNESDAY.
THIS WILL RESULT IN UNSETTLED WEATHER PATTERN AND COOLER
TEMPERATURES ACROSS MUCH OF OUR CWA. TEMPERATURES WILL REMAIN
NEAR...OR A COUPLE DEGREES ABOVE NORMAL THROUGH TUESDAY WITH
AFTERNOON HIGHS IN THE LOW 90S OVER THE PIEDMONT. TEMPERATURES WILL
DROP 5-10 DEGREES BY WEDNESDAY WITH HIGHS IN THE MID 80S OVER THE
PIEDMONT AND 70S MTNS.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AT KCLT...CONVECTIVE THREAT APPEARS NIL THIS AFTERNOON AS A CAPPING
INVERSION IS EXPECTED TO HOLD FIRM. EXPECT MCLR SKIES THROUGH
TONIGHT WITH SCT CU DEVELOPING LATE FRI MORNING. WINDS WILL REMAIN
GENERALLY LIGHT SW...EXCEPT FOR A FEW GUSTS TO AROUND 12KT LATE THIS
AFTERNOON.
ELSEWHERE...SIMILAR CONDITIONS TO KCLT EXCEPT FOR SOME LIGHT FOG AT
KAVL EARLY FRI. SLIGHT CHC POPS SHOULD REMAIN LIMITED TO THE MTNS THIS
AFTN.
OUTLOOK...CHANCE FOR THUDNERSTORMS WILL INCREASE FRI AS A SHORTWAVE
AND ASSOC WEAK COLD FRONT MOVE IN FROM THE NW. ANOTHER CHANCE FOR
THUNDERSTORMS WILL OCCUR SAT AFTERNOON AS ANOTHER COLD FRONT MOVES
THROUGH. THEN EXPECT A DAILY CHANCE FOR AFTERNOON CONVECTION INTO
THE MIDDLE OF NEXT WEEK...FIRST OVER SOUTHERN AREAS ON SUNDAY THEN
AREA WIDE AS UPPER TROF REMAINS OVER THE AREA.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR GAZ029.
NC...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR NCZ071-072-082.
SC...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR SCZ009-011>014-
019.
&&
$$
SYNOPSIS...JPT
NEAR TERM...LG
SHORT TERM...JPT
LONG TERM...JPT
AVIATION...LG